Experimental analysis of refrigerants flow boiling inside small sized microfin tubes

NASA Astrophysics Data System (ADS)

Diani, Andrea; Rossetto, Luisa

2017-07-01

The refrigerant charge reduction is one of the most challenging issues that the scientific community has to cope to reduce the anthropic global warming. Recently, mini microfin tubes have been matter of research, since they can reach better thermal performance in small domains, leading to a further refrigerant charge reduction. This paper presents experimental results about R134a flow boiling inside a microfin tube having an internal diameter at the fin tip of 2.4 mm. The mass flux was varied between 375 and 940 kg m-2 s-1, heat flux from 10 to 50 kW m-2, vapor quality from 0.10 to 0.99. The saturation temperature at the inlet of the test section was kept constant and equal to 30 °C. R134a thermal and fluid dynamic performances are presented and compared against those obtained with R1234ze(E) and R1234yf and against values obtained during R134a flow boiling inside a 3.4 mm ID microfin tube.

Experimental study on heat transfer performance of pulsating heat pipe with refrigerants

NASA Astrophysics Data System (ADS)

Wang, Xingyu; Jia, Li

2016-10-01

The effects of different refrigerants on heat transfer performance of pulsating heat pipe (PHP) are investigated experimentally. The working temperature of pulsating heat pipe is kept in the range of 20°C-50°C. The startup time of the pulsating heat pipe with refrigerants can be shorter than 4 min, when heating power is in the range of 10W?100W. The startup time decreases with heating power. Thermal resistances of PHP with filling ratio 20.55% were obviously larger than those with other filling ratios. Thermal resistance of the PHP with R134a is much smaller than that with R404A and R600a. It indicates that the heat transfer ability of R134a is better. In addition, a correlation to predict thermal resistance of PHP with refrigerants was suggested.

Energy Efficient Commercial Refrigeration with Carbon Dioxide Refrigerant and Scroll Expanders

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dieckmann, John

Current supermarket refrigeration systems are built around conventional fluorocarbon refrigerants – HFC-134a and the HFC blends R-507 and R404A, which replaced the CFC refrigerants, R-12 and R-502, respectively, used prior to the Montreal Protocol phase out of ozone depleting substances. While the HFC refrigerants are non-ozone depleting, they are strong greenhouse gases, so there has been continued interest in replacing them, particularly in applications with above average refrigerant leakage. Large supermarket refrigeration systems have proven to be particularly difficult to maintain in a leak-tight condition. Refrigerant charge losses of 15% of total charge per year are the norm, making themore » global warming impact of refrigerant emissions comparable to that associated with the energy consumption of these systems.« less

Performance of HCFC22 alternative refrigerants

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jung, D.; Kim, C.B.; Song, Y.J.

1999-07-01

In this study, 14 refrigerant mixtures composed of R32, R125, R134a, R152a, R290(Propane) and R1270(Propylene) were tested in a breadboard heat pump in an attempt to replace R22 used in residential air-conditioners. The test heat pump was of 1 ton capacity with water as the secondary heat transfer fluids. All tests were conducted under ARI test A condition. Test results how that ternary mixtures composed of R32, R125, and R134a have 4 {approximately} 5% higher coefficient of performance(COP) and capacity than R22. Hence they seem to be promising alternatives for R22. On the other hand, ternary mixtures containing R125, R134a,more » and R152a have lower COPs and capacities than R22. R290/R134 azeotrope also shows 3--4% increases in COP and capacity. The compressor discharge and dome temperatures of all the mixtures tested are lower than those of R22 by 15.9--34.7 C and 5.5--14.3 C respectively, indicating that these mixtures would offer better system reliability and longer life time than R22. Finally, the test results with a suction line heat exchanger (SLHX) indicated that SLHX must be used with special care in air-conditioners since its effect is fluid dependent.« less

A modeling study of a centrifugal compressor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Popovic, P.; Shapiro, H.N.

1998-12-31

A centrifugal compressor, which is part of a chlorofluorocarbon R-114 chiller installation, was investigated, operating with a new refrigerant, hydrofluorocarbon R-236ea, a proposed alternative to R-114. A large set of R-236ea operating data, as well as a limited amount of R-114 data, were available for this study. A relatively simple analytical compressor model was developed to describe compressor performance. The model was built upon a thorough literature search, experimental data, and some compressor design parameters. Two original empirical relations were developed, providing a new approach to the compressor modeling. The model was developed in a format that would permit itmore » to be easily incorporated into a complete chiller simulation. The model was found to improve somewhat on the quantitative and physical aspects of a compressor model of the same format found in the literature. It was found that the compressor model is specific to the particular refrigerant.« less

Investigation of two-phase thermosyphon performance filled with modern HFC refrigerants

NASA Astrophysics Data System (ADS)

Gorecki, Grzegorz

2018-02-01

Two-phase closed thermosyphons (TPCTs) are widely utilized as heat exchanger elements in waste heat recovery systems and as passive heating/cooling devices. They are popular because of their high thermal conductivity, simple construction and reliability. Previous researches indicate that refrigerants are performing better than typical TPCT working fluids like deionized water or alcohols in the low temperature range. In the present study three HFC (Hydrofluorocarbons) refrigerants were tested: R134a, R404A and R407C. The total length of the investigated TPCT is 550 mm with equal length (245 mm) condenser and evaporator sections. Its outer diameter is 22 mm with 1 mm wall thickness. The evaporator section was heated by hot water with varying inlet temperature by 5 K step in the range of 288 K - 323 K. The condenser was cooled by cold water with inlet temperature kept at a constant value of 283 K. It was found that using R134a and R404A as working fluids heat transfer rates are the highest. For both refrigerants 10% is optimal filling ratio. They can be utilized interchangeably because the differences between their throughputs are within uncertainty bands. R407C performance was 50% lower. Other disadvantages of using this refrigerant are relatively high working pressures and higher optimal filling ratio (30%).

Investigation of two-phase thermosyphon performance filled with modern HFC refrigerants

NASA Astrophysics Data System (ADS)

Gorecki, Grzegorz

2018-07-01

Two-phase closed thermosyphons (TPCTs) are widely utilized as heat exchanger elements in waste heat recovery systems and as passive heating/cooling devices. They are popular because of their high thermal conductivity, simple construction and reliability. Previous researches indicate that refrigerants are performing better than typical TPCT working fluids like deionized water or alcohols in the low temperature range. In the present study three HFC (Hydrofluorocarbons) refrigerants were tested: R134a, R404A and R407C. The total length of the investigated TPCT is 550 mm with equal length (245 mm) condenser and evaporator sections. Its outer diameter is 22 mm with 1 mm wall thickness. The evaporator section was heated by hot water with varying inlet temperature by 5 K step in the range of 288 K - 323 K. The condenser was cooled by cold water with inlet temperature kept at a constant value of 283 K. It was found that using R134a and R404A as working fluids heat transfer rates are the highest. For both refrigerants 10% is optimal filling ratio. They can be utilized interchangeably because the differences between their throughputs are within uncertainty bands. R407C performance was 50% lower. Other disadvantages of using this refrigerant are relatively high working pressures and higher optimal filling ratio (30%).

Miscibility comparison for three refrigerant mixtures and four component refrigerants

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kang, H.M.; Pate, M.B.

1999-07-01

Miscibility data were taken and compared for seven different refrigerants when mixed with the same polyol ester (POE) lubricant. Four of the seven refrigerants were single-component refrigerants while three of the refrigerants were mixtures composed of various combinations of the pure refrigerants. The purpose of this research was to investigate the difference in miscibility characteristics between refrigerant mixtures and their respective component refrigerants. The POE lubricant was a penta erythritol mixed-acid type POE which has a viscosity ISO32. The four pure refrigerants were R-32, R-125, R-134a, and R-143a and the three refrigerant mixtures were R-404A, R407C, and R-410A. The miscibilitymore » tests were performed in a test facility consisting of a series of miniature test cells submerged in a constant temperature bath. The test cells were constructed to allow for complete visibility of the refrigerant/lubricant mixtures under all test conditions. The tests were performed over a concentration range of 0 to 100% and a temperature range of {minus}40 to 194 F. The miscibility test results for refrigerant mixtures are compared to component refrigerants. In all cases, the refrigerant mixtures appear to have better miscibility than their most immiscible pure component.« less

Experimental study on a prototype of heat pipe solar water heater using refrigerant R134a as a transfer fluid

NASA Astrophysics Data System (ADS)

Sitepu, T.; Sembiring, J.; Ambarita, H.

2018-02-01

A prototype of a solar water heater by using refrigerant as a heat transfer fluid is investigated experimentally. The objective is to explore the characteristics and the performance of the prototype. To make heat transfer from the collector to the heated fluid effectively, refrigerant R134a is used as a transfer. In the experiments, the initial pressure inside the heat pipe is varied. The prototype is exposed to solar irradiation in a location in Medan city for three days of the experiment. Solar collector temperatures, solar radiation, water temperature, and ambient temperature are measured. The efficiency of the system is analyzed. The results show that temperature of the hot water increases as the initial pressure of the working fluid increase. However, the increasing is not linear, and there must exist an optimum initial pressure. For the case with the refrigerant pressure of 110 psi, the maximum hot water temperature and maximum thermal efficiency are 45.36oC and 53.23%, respectively. The main conclusion can be drawn here is that solar water heater by using refrigerant R134a should be operated at initial pressure 110 psi.

Compressed and saturated liquid densities for 18 halogenated organic compounds

DOE Office of Scientific and Technical Information (OSTI.GOV)

Defibaugh, D.R.; Moldover, M.R.

1997-01-01

The pressure-density-temperature P({rho},T) behavior of 18 liquids that are potential working fluids in thermal machinery has been measured using a vibrating tube densimeter. For each liquid, the data were taken on isotherms spaced at intervals of 5 K to 10 K spanning the temperature range 245 K to 370 K. The pressures ranged from just above the vapor pressure (or the critical pressure) to 6500 kPa. The results of measurements at more than 12,000 thermodynamic points are summarized by correlating functions. Comparison with data from other laboratories indicates that the relative expanded uncertainty in the measured densities is less thanmore » 0.05%, except in the critical region. The repeatability of the vapor pressure to obtain the density of the liquid at the vapor pressure. The fluids studied (and their designations by the refrigeration industry) were trichlorofluoromethane (R11), chlorodifluoromethane (R22), 1,1-dichloro-2,2,2-trifluoroethane (R123), 1,2-dichloro-1,2,2-trifluoroethane (R123a), 1-chloro-1,2,2,2-tetrafluoroethane (R124), 1,1,2,2-tetrafluoroethane (R134), 1,1,1,2-tetrafluoroethane (R134a), 1,1-dichloro-1-fluoroethane (R141b), 1,1,1-trifluoroethane (R143), 1,1,2-trifluoroethane (R143a), pentafluorodimethyl ether (E125), 1,1-difluoroethane (R152a), octafluoropropane (R218), 1,1,1,2,3,3,3-heptafluoropropane (R227ea), 2-(difluoromethoxy)-1,1,1-trifluoroethane (E245), 1,1,1,2,2-pentafluoropropane (R245cb), 1,1,1,3,3-pentafluoropropane (R245fa), and propane (R290).« less

R-134a qualification -- industry refrigerator capillary data

DOE Office of Scientific and Technical Information (OSTI.GOV)

DeVos, R.

1997-12-31

With the phaseout of R-12, the use of R-134a and polyolester (POE) oil became the preferred refrigerant/oil combination for the refrigerator appliance industry. Reliability data for this refrigerant/oil combination were minimal, and initial testing showed a propensity for the capillary tubes to clog with a variety of contaminants. A test was designed by an industry group to accelerate the process of contamination and capillary plugging. This paper presents capillary tube stress test data that were developed for this group by its member companies. This study investigated the relationship between capillary tube restriction levels and variables including compressor type, oil type,more » chlorine level, and moisture level. Analysis of the contaminants included a visual description, infrared spectroscopy, scanning electron microscope examination, and measurements of total chlorine content and noncondensable gas content of the refrigerant. Oil samples were measured for moisture level, dissolved iron, and total acid, and an infrared spectral analysis was performed.« less

R-134a (1,1,1,2-Tetrafluoroethane) Inhalation Induced Reactive Airways Dysfunction Syndrome.

PubMed

Doshi, Viral; Kham, Nang; Kulkarni, Shreedhar; Kapitan, Kent; Henkle, Joseph; White, Peter

2016-01-01

R-134a (1,1,1,2-tetrafluoroethane) is widely used as a refrigerant and as an aerosol propellant. Inhalation of R-134a can lead to asphyxia, transient confusion, and cardiac arrhythmias. We report a case of reactive airways dysfunction syndrome secondary to R-134a inhalation. A 60-year-old nonsmoking man without a history of lung disease was exposed to an air conditioner refrigerant spill while performing repairs beneath a school bus. Afterward, he experienced worsening shortness of breath with minimal exertion, a productive cough, and wheezing. He was also hypoxic. He was admitted to the hospital for further evaluation. Spirometry showed airflow obstruction with an FEV1 1.97 L (45% predicted). His respiratory status improved with bronchodilators and oral steroids. A repeat spirometry 2 weeks later showed improvement with an FEV1 2.5 L (60% predicted). Six months after the incident, his symptoms had improved, but he was still having shortness of breath on exertion and occasional cough.

Microscopic structure of liquid 1-1-1-2-tetrafluoroethane (R134a) from Monte Carlo simulation.

PubMed

Do, Hainam; Wheatley, Richard J; Hirst, Jonathan D

2010-10-28

1-1-1-2-tetrafluoroethane (R134a) is one of the most commonly used refrigerants. Its thermophysical properties are important for evaluating the performance of refrigeration cycles. These can be obtained via computer simulation, with an insight into the microscopic structure of the liquid, which is not accessible to experiment. In this paper, vapour-liquid equilibrium properties of R134a and its liquid microscopic structure are investigated using coupled-decoupled configurational-bias Monte Carlo simulation in the Gibbs ensemble, with a recent potential [J. Phys. Chem. B 2009, 113, 178]. We find that the simulations agree well with the experimental data, except at the vicinity of the critical region. Liquid R134a packs like liquid argon, with a coordination number in the first solvation shell of 12 at 260 K. The nearest neighbours prefer to be localized in three different spaces around the central molecule, in such a manner that the dipole moments are in a parallel alignment. Analysis of the pair interaction energy shows clear association of R134a molecules, but no evidence for C-HF type hydrogen bonding is found. The above findings should be of relevance to a broad range of fluoroalkanes.

Energy Efficiency and Environmental Impact Analyses of Supermarket Refrigeration Systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fricke, Brian A; Bansal, Pradeep; Zha, Shitong

This paper presents energy and life cycle climate performance (LCCP) analyses of a variety of supermarket refrigeration systems to identify designs that exhibit low environmental impact and high energy efficiency. EnergyPlus was used to model refrigeration systems in a variety of climate zones across the United States. The refrigeration systems that were modeled include the traditional multiplex DX system, cascade systems with secondary loops and the transcritical CO2 system. Furthermore, a variety of refrigerants were investigated, including R-32, R-134a, R-404A, R-1234yf, R-717, and R-744. LCCP analysis was used to determine the direct and indirect carbon dioxide emissions resulting from themore » operation of the various refrigeration systems over their lifetimes. Our analysis revealed that high-efficiency supermarket refrigeration systems may result in up to 44% less energy consumption and 78% reduced carbon dioxide emissions compared to the baseline multiplex DX system. This is an encouraging result for legislators, policy makers and supermarket owners to select low emission, high-efficiency commercial refrigeration system designs for future retrofit and new projects.« less

EVALUATION OF PERFORMANCE AND COMPOSITION SHIFT OF ZEOTROPIC MIXTURES IN A LORENZ-MEUTZNER REFRIGERATOR/FREEZER

EPA Science Inventory

Results from previous testing of this refrigerator/freezer (R/F) using a 750 Btu/hr compressor and several zeotrophic mixtures revealed a performance enhancement up to 16 percent above that of HFC-134a. In the study presented in this paper, the Lorenz-Meutzner (LM) R/F equipped ...

Vapor-liquid equilibria for R-22, R-134a, R-125, and R-32/125 with a polyol ester lubricant: Measurements and departure from ideality

DOE Office of Scientific and Technical Information (OSTI.GOV)

Martz, W.L.; Burton, C.M.; Jacobi, A.M.

1996-11-01

The effect of a polyol ester lubricant on equilibrium pressure, liquid density, and viscosity is presented for R-22, R-125, and R-134a at varying temperatures and concentrations. Preliminary vapor-liquid equilibrium (VLE) data and miscibility observations are also presented for an R-32/R-125 blend (50%/50%) with the ISO 68 polyol ester (POE). Real-gas behavior is modeled using the vapor-phase fugacity, and vapor pressure effects on liquid fugacities are taken into account with the Poynting effect. Positive, negative, and mixed deviations form the Lewis-Randall rule are observed in the activity coefficient behavior. Departures from ideality are related to molecular size differences, intermolecular forces inmore » the mixture, and other factors. The data are discussed in the context of previous results for other refrigerants and thermodynamic modeling of refrigerant and oil mixtures.« less

The impact of charge on the cooling performance of an air-to-air heat pump for R-22 and three binary blends of R-32 and R-134a

DOE Office of Scientific and Technical Information (OSTI.GOV)

Robinson, J.H.; O`Neal, D.L.

1994-12-31

An experimental study was conducted in which the performance of three blends of R-134a and R-32 was compared to that of R-22. The effect of refrigerant charge on the performance of these refrigerants in an air-to-air heat pump operating in the cooling mode was quantified The mixtures consisted of 40%/60%, 30%/70%, and 20%/80% ratios (by mass) of R-32 and R-134a. Charge levels of 5.00, 5.45, 5.90, and 6.00 kg (11, 12, 13, and 14 lb) were tested. At each charge level, outdoor room conditions of 27.8 C, 35.0 C, and 40.6 C (82 F, 95 F, and 105 F) weremore » tested The expansion device for all tests was a 1.96 mm (0.077 in.) diameter orifice. Three variables were used to quantify refrigerant performance-total capacity, total electrical power consumption, and coefficient of performance (COP). The performance of the heat pump with any of the three mixtures was not as good as with R-22. The capacities were between 7% and 17% less than with R-22. The best COPs with the mixtures were within 3% of that with R-22 in some cases, but the corresponding capacities at these COPs were approximately 12% lower than that in the R-22 base case. The best results for a mixture were with the 40%/60% blend. The capacity was 7.3% less than the base case and the COP was 8.5% lower.« less

Comprehensive Compressor Calorimeter Testing of Lower-GWP Alternative Refrigerants for Heat Pump and Medium Temperature Refrigeration Applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shrestha, Som S; Sharma, Vishaldeep; Abdelaziz, Omar

In response to environmental concerns raised by the use of refrigerants with high Global Warming Potential (GWP), the Air-Conditioning, Heating, and Refrigeration Institute (AHRI) has launched an industry-wide cooperative research program, referred to as the Low-GWP Alternative Refrigerants Evaluation Program (AREP), to identify and evaluate promising alternative refrigerants for major product categories. This paper reports one of the Oak Ridge National Laboratory (ORNL) contributions to AREP. It compares performance of alternative refrigerants to that of R-410A and R-404A for heat pump and medium temperature applications, respectively. The alternatives reported in this paper are: R-32, DR-5, and L-41a for R-410A andmore » ARM-31a, D2Y-65, L-40, and a mixture of R-32 and R-134a for R-404A. All performance comparison tests were conducted using scroll compressors of ~1.85 tons (6.5 kW) cooling capacity. Tests were conducted over a range of combinations of saturation suction and saturation discharge temperatures for both compressors. The tests showed that, in general, energy efficiency ratio (EER) and cooling capacity of R-410A alternative refrigerants were slightly lower than that of the baseline refrigerant with a moderate increases in discharge temperature. On the other hand, R-404A alternative refrigerants showed relative performance dependence on saturation suction and saturation discharge temperatures and larger increases in discharge temperature than for the R-410A alternatives. This paper summarizes the relative performance of all alternative refrigerants compared to their respective baseline.« less

Performance optimization of CO 2 heat pump water heater

DOE PAGES

Nawaz, Kashif; Shen, Bo; Elatar, Ahmed; ...

2017-10-14

A preliminary analysis was conducted to analyze the performance of a heat pump water heater (HPWH) that uses CO 2 as the refrigerant. A model to predict the performance was developed and calibrated based on the experimental data for an existing HPWH using a CO 2 refrigerant. The calibrated model was then used to run a parametric analysis in which factors such as water supply temperature, water circulation rate, tank stratification, and condenser configuration were considered. The performance of a commercial CO 2 system was compared with that of a similar system using R-134a as the refrigerant. It was foundmore » that CO 2 HPWH performance was comparable to that of an R-134a HPWH, more so for a separated gas cooler configuration. For comparable performance, the compressor size and the tube-in-tube heat exchanger (condenser/gas cooler) size were compared for CO 2- and R-134a-based systems. Finally, the impact of the water circulation rate on the water temperature stratification in the tank, an essential requirement for higher performance for CO 2 HPWH systems was also investigated.« less

Performance optimization of CO 2 heat pump water heater

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nawaz, Kashif; Shen, Bo; Elatar, Ahmed

A preliminary analysis was conducted to analyze the performance of a heat pump water heater (HPWH) that uses CO 2 as the refrigerant. A model to predict the performance was developed and calibrated based on the experimental data for an existing HPWH using a CO 2 refrigerant. The calibrated model was then used to run a parametric analysis in which factors such as water supply temperature, water circulation rate, tank stratification, and condenser configuration were considered. The performance of a commercial CO 2 system was compared with that of a similar system using R-134a as the refrigerant. It was foundmore » that CO 2 HPWH performance was comparable to that of an R-134a HPWH, more so for a separated gas cooler configuration. For comparable performance, the compressor size and the tube-in-tube heat exchanger (condenser/gas cooler) size were compared for CO 2- and R-134a-based systems. Finally, the impact of the water circulation rate on the water temperature stratification in the tank, an essential requirement for higher performance for CO 2 HPWH systems was also investigated.« less

Heat transfer and structure of flow at boiling of refrigerant R134a in channels with inserts in the form of finned twisted tape

NASA Astrophysics Data System (ADS)

Shishkin, A. V.; Tarasevich, S. E.

2018-03-01

The paper presents the results of experimental study of heat transfer for the refrigerant R134a flow in the channels with finned twisted tape inserts at bubble boiling. The flow regimes implemented under the given conditions are shown. The stable cord-like flows appear at boiling in channels with twisted tape inserts and high vapor content when the liquid phase moves in the form of a stream (cord) along the central part of the tape, which is not an active heat exchange surface. At boiling this can lead to an increase in the length required for complete liquid evaporation. Existing geometric modifications of twisted tapes are used in the heat-exchange equipment at forced convection of the coolant and do not solve the problem of cord-like flows elimination. The present work discusses the experimental study of heat transfer at boiling of refrigerant R134a in the channels with twisted tape inserts that have fins on its surface.

The optimum intermediate pressure of two-stages vapor compression refrigeration cycle for Air-Conditioning unit

NASA Astrophysics Data System (ADS)

Ambarita, H.; Sihombing, H. V.

2018-03-01

Vapor compression cycle is mainly employed as a refrigeration cycle in the Air-Conditioning (AC) unit. In order to save energy, the Coefficient of Performance (COP) of the need to be improved. One of the potential solutions is to modify the system into multi-stages vapor compression cycle. The suitable intermediate pressure between the high and low pressures is one of the design issues. The present work deals with the investigation of an optimum intermediate pressure of two-stages vapor compression refrigeration cycle. Typical vapor compression cycle that is used in AC unit is taken into consideration. The used refrigerants are R134a. The governing equations have been developed for the systems. An inhouse program has been developed to solve the problem. COP, mass flow rate of the refrigerant and compressor power as a function of intermediate pressure are plotted. It was shown that there exists an optimum intermediate pressure for maximum COP. For refrigerant R134a, the proposed correlations need to be revised.

Combustibility Tests of 1,1,1,2-tetrafluoroethane in a Simulated Compressor Cylinder

NASA Technical Reports Server (NTRS)

Babcock, Dale A.; Bruce, Robert A.

1997-01-01

The advantages of high-molecular-weight gas (heavy gas) as a wind-tunnel medium have been recognized for some time. The current heavy gas of choice chlorofluorocarbon-12(CFC-12) (refrigerant R12) for the Transonic Dynamics Tunnel(TDT) must be replaced because manufacture of this gas ceased in 1995. An attractive replacement is 1,1,1,2-tetrafluoroethane (refrigerant R134a). Acceptable properties of this gas include molecular weight and speed of sound. Its vapor pressure allows simplified reclamation from mixtures with air. However, it is recognized that R134a is combustible under certain conditions of temperature, pressure, and concentration. A comprehensive study was conducted to identify those conditions and the influence of various parameters on the combustibility of the gas-air mixture.

Correlation and prediction of the transport properties of refrigerants using two modified rough hard-sphere models

DOE Office of Scientific and Technical Information (OSTI.GOV)

Teja, A.S.; King, R.K.; Sun, T.F.

1999-01-01

Two methods are presented for the correlation and prediction of the viscosities and thermal conductivities of refrigerants R11, R12, R22, R32, R124, R125, R134a, R141b, and R152 and their mixtures. The first (termed RHS1) is a modified rough-hard-sphere method based on the smooth hard-sphere correlations of Assael et al. The method requires two or three parameters for characterizing each refrigerant but is able to correlate transport properties over wide ranges of pressure and temperature. The second method (RHS2) is also a modified rough-hard-sphere method, but based on an effective hard-sphere diameter for Lennard-Jones (LJ) fluids. The LJ parameters and themore » effective hard-sphere diameter required in this method are determined from a knowledge of the density-temperature behavior of the fluid at saturation. Comparisons with the rough-hard-sphere method of Assael and co-workers (RHS3) are shown. They also show that the RHS2 method can be used to correlate as well as predict the transport properties of refrigerants.« less

IDENTIFYING AND EVALUATING ALTERNATIVES TO CFC-114 FOR NAVY SHIPBOARD CHILLERS

EPA Science Inventory

The paper outlines EPA's role in investigating alternatives to replace the chlorofluorocarbon CFC-114 (1,1,2,2-tetrafluorodichloroethane) as the refrigerant in retrofitted Navy shipboard chillers. The isomers HFC-236ea (1,1,1,2,3,3-hexafluoropropane) and HFC-236fa (1,1,1,3,3,3-he...

Pilot retrofit test of refrigerant R-134a for GDSCC

NASA Technical Reports Server (NTRS)

Albus, J.; Brown, B.; Dungao, M.; Spencer, G.

1994-01-01

NASA has issued an interim policy requiring all of its Centers to eliminate consumption (purchase) of stratospheric ozone-depleting substances, including chlorofluorocarbons (CFC's), by 1995. Also, plans must be outlined for the eventual phase out of their usage. The greatest source of CFC consumption and usage at the Goldstone Deep Space Communications Complex is refrigerant R-12, which is used in many of the facility's air-conditioning systems. A pilot retrofit test shows that retrofitting R-12 air-conditioning systems with hydrofluorocarbon R-13a would be a workable means to comply with the R-12 portion of NASA's policy. Results indicate acceptable cost levels and nearly equivalent system performance.

Fundamental basis and implementation of shell and tube heat exchanger project design: condenser and evaporator study

NASA Astrophysics Data System (ADS)

Dalkilic, A. S.; Acikgoz, O.; Tapan, S.; Wongwises, S.

2016-12-01

A shell and tube heat exchanger is used as a condenser and an evaporator in this theoretical study. Parametric performance analyses for various actual refrigerants were performed using well-known correlations in open sources. Condensation and evaporation were occurred in the shell side while the water was flowing in the tube side of heat exchanger. Heat transfer rate from tube side was kept constant for condenser and evaporator design. Condensing temperatures were varied from 35 to 60 °C whereas evaporating temperatures were ranging from -15 to 10 °C for the refrigerants of R12, R22, R134a, R32, R507A, R404A, R502, R407C, R152A, R410A and R1234ZE. Variation of convective heat transfer coefficients of refrigerants, total heat transfer coefficients with Reynolds numbers and saturation temperatures were given as validation process considering not only fouling resistance and omission of it but also staggered (triangular) and line (square) arrangements. The minimum tube lengths and necessary pumping powers were calculated and given as case studies for the investigated refrigerants considering validation criteria. It was understood that refrigerant type, fouling resistance and arrangement type are one of the crucial issues regarding the determination of heat exchanger's size and energy consumption. Consequently, R32 and R152a were found to require the shortest tube length and lowest pumping power in the condenser, whereas R507 and R407C have the same advantages in the evaporator. Their heat transfer coefficients were also determined larger than others as expectedly.

R-134a emissions from vehicles.

PubMed

Siegl, W O; Wallington, T J; Guenther, M T; Henney, T; Pawlak, D; Duffy, M

2002-02-15

We report the first study of R-134a (also known as HFC-134a and CF3CFH2) refrigerant leakage from air conditioning (AC) systems of modern vehicles. Twenty-eight light duty vehicles from five manufacturers (Ford, Toyota, Daimler Chrysler, General Motors, and Honda) were tested according to the USEPA (Federal) extended diurnal test procedure using the Sealed Housing for Evaporative Determination (SHED) apparatus. All tests were conducted using stationary vehicles with the motor and air conditioning system turned off. R-134a was measured using gas chromatography (GC) with a flame ionization detector (FID). All vehicles exhibited measurable R-134a leakage over the 2-day diurnal test. Leak rates of R-134a ranged from 0.01 to 0.36 g/day with an average of 0.07+/-0.07 g/day. When combined with leakage associated with vehicle operation, servicing, and disposal we estimate that the lifetime average R-134a emission rate from an AC equipped vehicle is 0.41+/-0.27 g/day (the majority of emissions are associated with vehicle servicing and disposal). Assuming that the average vehicle travels 10 000 miles per year we estimate that the global warming impact of R-134a leakage from an AC equipped vehicle is approximately 4-5% of that of the CO2 emitted by the vehicle. The results are discussed with respect to the contribution of vehicle emissions to global climate change.

Alternative working fluids for unitary equipment: A research perspective

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baxter, V.D.

This paper deals with present and planned ORNL activities to characterize alternatives to R-22 for unitary heat pump and air-conditioning applications. Results of small-scale bread-board tests of potential alternatives R-32, R-134a, R-152a and R-143a are discussed. Portions of the AFEAS/DOE global warming impact study dealing with the unitary application are summarized. Methods for leak detection with the new refrigerants are discussed.

Greenhouse gas emissions for refrigerant choices in room air conditioner units.

PubMed

Galka, Michael D; Lownsbury, James M; Blowers, Paul

2012-12-04

In this work, potential replacement refrigerants for window-mounted room air conditioners (RACs) in the U.S. have been evaluated using a greenhouse gas (GHG) emissions analysis. CO(2)-equivalent emissions for several hydrofluoroethers (HFEs) and other potential replacements were compared to the most widely used refrigerants today. Included in this comparison are pure refrigerants that make up a number of hydrofluorocarbon (HFC) mixtures, pure hydrocarbons, and historically used refrigerants such as propane and ammonia. GHG emissions from direct and indirect sources were considered in this thermodynamic analysis. Propylene, dimethyl ether, ammonia, R-152a, propane, and HFE-152a all performed effectively in a 1 ton window unit and produced slightly lower emissions than the currently used R-22 and R-134a. The results suggest that regulation of HFCs in this application would have some effect on reducing emissions since end-of-life emissions remain at 55% of total refrigerant charge despite EPA regulations that mandate 80% recovery. Even so, offsite emissions due to energy generation dominate over direct GHG emissions and all the refrigerants perform similarly in totals of indirect GHG emissions.

Design of refrigeration system using refrigerant R134a for macro compartment

NASA Astrophysics Data System (ADS)

Rani, M. F. H.; Razlan, Z. M.; Shahriman, A. B.; Yong, C. K.; Harun, A.; Hashim, M. S. M.; Faizi, M. K.; Ibrahim, I.; Kamarrudin, N. S.; Saad, M. A. M.; Zunaidi, I.; Wan, W. K.; Desa, H.

2017-10-01

The main objective of this study is to analyse and design an optimum cooling system for macro compartment. Current product of the refrigerator is not specified for single function and not compact in size. Hence, a refrigeration system using refrigerant R134a is aimed to provide instant cooling in a macro compartment with sizing about 150 × 150 × 250 mm. The macro compartment is purposely designed to fit a bottle or drink can, which is then cooled to a desired drinking temperature of about 8°C within a period of 1 minute. The study is not only concerned with analysing of heat load of the macro compartment containing drink can, but also focused on determining suitable heat exchanger volume for both evaporator and condenser, calculating compressor displacement value and computing suitable resistance value of the expansion valve. Method of optimization is used to obtain the best solution of the problem. Mollier diagram is necessary in the process of developing the refrigeration system. Selection of blower is made properly to allow air circulation and to increase the flow rate for higher heat transfer rate. Property data are taken precisely from thermodynamic property tables. As the main four components, namely condenser, compressor, evaporator and expansion valve are fully developed, the refrigeration system is complete.

Flow Pattern Identification of Horizontal Two-Phase Refrigerant Flow Using Neural Networks

DTIC Science & Technology

2015-12-31

AFRL-RQ-WP-TP-2016-0079 FLOW PATTERN IDENTIFICATION OF HORIZONTAL TWO-PHASE REFRIGERANT FLOW USING NEURAL NETWORKS (POSTPRINT) Abdeel J...Journal Article Postprint 01 October 2013 – 22 June 2015 4. TITLE AND SUBTITLE FLOW PATTERN IDENTIFICATION OF HORIZONTAL TWO-PHASE REFRIGERANT FLOW USING...networks were used to automatically identify two-phase flow patterns for refrigerant R-134a flowing in a horizontal tube. In laboratory experiments

R1234yf vs. R134a Flow Boiling Heat Transfer Inside a 3.4 mm ID Microfin Tube

NASA Astrophysics Data System (ADS)

Diani, A.; Mancin, S.; Rossetto, L.

2014-11-01

The refrigerant charge minimization as well as the use of eco-friendly fluids can be considered two of the most important targets for these applications to cope with the new environmental challenges. This paper compares the R1234yf and R134a flow boiling heat transfer and pressure drop measurements inside a small microfin tube with internal diameter at the fin tip of 3.4 mm. This study is carried out in an experimental facility built at the Dipartimento di Ingegneria Industriale of the University of Padova especially designed to study both single and two phase heat transfer processes. The microfin tube is brazed inside a copper plate and electrically heated from the bottom. Several T -type thermocouples are inserted in the wall to measure the temperature distribution during the phase change process. In particular, the experimental measurements were carried out at constant saturation temperature of 30 °C, by varying the refrigerant mass velocity between 190 kg m-2 s-1 and 940 kg m-2 s-1, the vapour quality from 0.2 to 0.99, at different imposed heat fluxes. The two refrigerants are compared considering the values of the two-phase heat transfer coefficient and pressure drop.

Feasibility analysis of a Commercial HPWH with CO 2 Refrigerant

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nawaz, Kashif; Shen, Bo; Elatar, Ahmed F.

2017-02-12

A scoping-level analysis has conducted to establish the feasibility of using CO 2 as refrigerant for a commercial heat pump water heater (HPWH) for U.S. applications. The DOE/ORNL Heat Pump Design Model (HPDM) modeling tool was used for the assessment with data from a Japanese heat pump water heater (Sanden) using CO 2 as refrigerant for calibration. A CFD modeling tool was used to further refine the HPDM tank model. After calibration, the model was used to simulate the performance of commercial HPWHs using CO 2 and R-134a (baseline). The parametric analysis concluded that compressor discharge pressure and water temperaturemore » stratification are critical parameters for the system. For comparable performance the compressor size and water-heater size can be significantly different for R-134 and CO 2 HPWHs. The proposed design deploying a gas-cooler configuration not only exceeds the Energy Star Energy Factor criteria i.e. 2.20, but is also comparable to some of the most efficient products in the market using conventional refrigerants.« less

Depicting mass flow rate of R134a /LPG refrigerant through straight and helical coiled adiabatic capillary tubes of vapor compression refrigeration system using artificial neural network approach

NASA Astrophysics Data System (ADS)

Gill, Jatinder; Singh, Jagdev

2018-07-01

In this work, an experimental investigation is carried out with R134a and LPG refrigerant mixture for depicting mass flow rate through straight and helical coil adiabatic capillary tubes in a vapor compression refrigeration system. Various experiments were conducted under steady-state conditions, by changing capillary tube length, inner diameter, coil diameter and degree of subcooling. The results showed that mass flow rate through helical coil capillary tube was found lower than straight capillary tube by about 5-16%. Dimensionless correlation and Artificial Neural Network (ANN) models were developed to predict mass flow rate. It was found that dimensionless correlation and ANN model predictions agreed well with experimental results and brought out an absolute fraction of variance of 0.961 and 0.988, root mean square error of 0.489 and 0.275 and mean absolute percentage error of 4.75% and 2.31% respectively. The results suggested that ANN model shows better statistical prediction than dimensionless correlation model.

Applications of the Simple Multi-Fluid Model to Correlations of the Vapor-Liquid Equilibrium of Refrigerant Mixtures Containing Carbon Dioxide

NASA Astrophysics Data System (ADS)

Akasaka, Ryo

This study presents a simple multi-fluid model for Helmholtz energy equations of state. The model contains only three parameters, whereas rigorous multi-fluid models developed for several industrially important mixtures usually have more than 10 parameters and coefficients. Therefore, the model can be applied to mixtures where experimental data is limited. Vapor-liquid equilibrium (VLE) of the following seven mixtures have been successfully correlated with the model: CO2 + difluoromethane (R-32), CO2 + trifluoromethane (R-23), CO2 + fluoromethane (R-41), CO2 + 1,1,1,2- tetrafluoroethane (R-134a), CO2 + pentafluoroethane (R-125), CO2 + 1,1-difluoroethane (R-152a), and CO2 + dimethyl ether (DME). The best currently available equations of state for the pure refrigerants were used for the correlations. For all mixtures, average deviations in calculated bubble-point pressures from experimental values are within 2%. The simple multi-fluid model will be helpful for design and simulations of heat pumps and refrigeration systems using the mixtures as working fluid.

76 FR 61269 - Protection of Stratospheric Ozone: acceptability Determination 26 for Significant New...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-10-04

...://www.regulations.gov . A. Refrigeration and Air Conditioning 1. Hot Shot 2 EPA's decision: EPA finds Hot Shot 2 is acceptable as a substitute for CFC-12, CFC-11, CFC-113, CFC-114, R-13B1, R-500, R-502... conditioning and heat pumps Hot Shot 2 is a blend by weight of 79.3 percent HFC-134a, which is also known as 1...

Solid-State Quantum Refrigeration

DTIC Science & Technology

2013-03-01

i n a l Te c h n... i c a l Re p o r t Name of Grantee: Northwestern University Grant Title: Solid-State Quantum Refrigeration Grant #: FA9550-09-1...200 -150 -100 -50 0 Anglewavelength b a c k c o u p lin g i n to th e w a v e g u id e l o s s ( d B ) Figure 8. results of a) percentage

Thermodynamic Analysis of a Mixed Refrigerant Ejector Refrigeration Cycle Operating with Two Vapor-liquid Separators

NASA Astrophysics Data System (ADS)

Tan, Yingying; Chen, Youming; Wang, Lin

2018-06-01

A mixed refrigerant ejector refrigeration cycle operating with two-stage vapor-liquid separators (MRERC2) is proposed to obtain refrigeration temperature at -40°C. The thermodynamic investigations on performance of MRERC2 using zeotropic mixture refrigerant R23/R134a are performed, and the comparisons of cycle performance between MRERC2 and MRERC1 (MRERC with one-stage vapor-liquid separator) are conducted. The results show that MRERC2 can achieve refrigeration temperature varying between -23.9°C and -42.0°C when ejector pressure ratio ranges from 1.6 to 2.3 at the generation temperature of 57.3-84.9°C. The parametric analysis indicates that increasing condensing temperature decreases coefficient of performance ( COP) of MRERC2, and increasing ejector pressure ratio and mass fraction of the low boiling point component in the mixed refrigerant can improve COP of MRERC2. The MRERC2 shows its potential in utilizing low grade thermal energy as driving power to obtain low refrigeration temperature for the ejector refrigeration cycle.

Redesign 3 R Machine as a Refrigerant Waste Treatment Alternative in Environmental Rescue

NASA Astrophysics Data System (ADS)

Negara, I. P. S.; Arsawan, I. M.

2018-01-01

Cooling machine technologies really affect nowadays’ modern life, not only limited in enhancement of life quality and comfort, but it has also reached the essential things of humans’ life supporter (Arora, 2001). Cooling machine technologies have direct contribution toward environmental damage such as depletion of ozone layer and global warming through synthetic refrigerant waste and leakage (CFC and HFC) to environment. The refrigerant release to the environment is 60% of the service sector. Destructive characteristics of ozone possessed by CFC were first proposed by Rowland and Molina which were then supported by yard measurement. It is estimated that ozone layer damage occurs for about 3% every decade. The ozone layer located in the stratosphere is functioned to prevent ultraviolet-B ray from entering into earth surface. This Ultraviolet-B is suspected to be the cause of health problem for humans and disorder for plants on earth. As for the purpose of this research is to obtain a product design of refrigerant waste processing system (recovery and recycle refrigerant) as well as to acknowledge the work method (COP) of cooling machines that use CFC refrigerant (R-12) as the result of recovery and recycle compared to CFC refrigerant (R-12)/pure R134a. One method that can be used is by redesigning existing equipment namely 3R machine that cannot be used anymore thus it can be reused. This research will be conducted through modifying the existing 3R machine therefore it can be reused and be easily operated as well as doing the maintenance, after that the refrigerant as the result of recovery will be tried on a refrigeration system and a test of refrigeration system work method will be conducted by using the refrigerant recycle product which is obtained and compared with the work method of the one with pure refrigeration.The result has been achieved that the redesign product of refrigerant waste processing equipment can be reused and able to perform the recovery, recycle and richarging process, although using semi-automatic control system. So the use of car air conditioning refrigerant can be more efficient. With the functioning of 3R mesi is expected wastes refrigerant is not wasted which is one of the efforts to save the environment.

Comparative study during condensation of R152 a and R134 a with presence of non-condensable gas inside a vertical tube

NASA Astrophysics Data System (ADS)

Charef, Adil; Feddaoui, M'barek; Najim, Monssif; Meftah, Hicham

2018-04-01

A computational study of the liquid film condensation from vapour-gas mixtures of HFC refrigerants inside a vertical tube is performed. The external wall of the tube is subjected to constant temperature. The model uses an implicit finite difference method to solve the governing equations for the liquid film and gas flow together including the boundary and interfacial matching conditions. Parametric computations were realised to examine the effects of inlet Reynolds number, tube length, and inlet temperature of the gas mixtures on the condensation mechanism. A comparative study between the results obtained for studied R152 a and R134 a with presence of non-condensable gas is made. The predicted results indicate that the condensation of R152 a-air corresponds to a higher accumulated condensation m c d and local heat transfer coefficient h T when compared to R134 a-air in the same conditions. Increasing the inlet Reynolds number or the tube length improve the condensation. Additionally, lower non-condensable gas in R152 a - a i r substantially enhances the heat and mass exchanges.

Analysis of the Properties of Working Substances for the Organic Rankine Cycle based Database "REFPROP"

NASA Astrophysics Data System (ADS)

Galashov, Nikolay; Tsibulskiy, Svyatoslav; Serova, Tatiana

2016-02-01

The object of the study are substances that are used as a working fluid in systems operating on the basis of an organic Rankine cycle. The purpose of research is to find substances with the best thermodynamic, thermal and environmental properties. Research conducted on the basis of the analysis of thermodynamic and thermal properties of substances from the base "REFPROP" and with the help of numerical simulation of combined-cycle plant utilization triple cycle, where the lower cycle is an organic Rankine cycle. Base "REFPROP" describes and allows to calculate the thermodynamic and thermophysical parameters of most of the main substances used in production processes. On the basis of scientific publications on the use of working fluids in an organic Rankine cycle analysis were selected ozone-friendly low-boiling substances: ammonia, butane, pentane and Freon: R134a, R152a, R236fa and R245fa. For these substances have been identified and tabulated molecular weight, temperature of the triple point, boiling point, at atmospheric pressure, the parameters of the critical point, the value of the derivative of the temperature on the entropy of the saturated vapor line and the potential ozone depletion and global warming. It was also identified and tabulated thermodynamic and thermophysical parameters of the steam and liquid substances in a state of saturation at a temperature of 15 °C. This temperature is adopted as the minimum temperature of heat removal in the Rankine cycle when working on the water. Studies have shown that the best thermodynamic, thermal and environmental properties of the considered substances are pentane, butane and R245fa. For a more thorough analysis based on a gas turbine plant NK-36ST it has developed a mathematical model of combined cycle gas turbine (CCGT) triple cycle, where the lower cycle is an organic Rankine cycle, and is used as the air cooler condenser. Air condenser allows stating material at a temperature below 0 °C. Calculation of the parameters of all substances in the model are based on a base "REFPROP". Numerical investigations on this model showed that the highest net efficiency will be at work on pentane. Butane and R245fa have the same net efficiency, for 0.8% lower than pentane. Ammonia has a net efficiency of 2.5% is lower than pentane. CCP net efficiency strongly depends on the condensation temperature of the substance, as for pentane at lower temperature of condensation at 10 °C it is increased by 1%.

Adsorption of dichlorodifluoromethane, chlorodifluoromethane, chloropentafluoroethane, 1,1-difluoroethane, and 1,1,1,2-tetrafluoroethane on silica gel

DOE Office of Scientific and Technical Information (OSTI.GOV)

Frere, M.; Berlier, K.; Bougard, J.

1994-10-01

The CFC's (chlorofluorocarbons) are used as working refrigerants fluids. The most commonly used are R12, R22, and R502 (48.8% R22 and 51.2% R115). Recent concerns of the effects of CFC's on the ozone layer require the development of efficient recovery methods. One technique is to adsorb the fluids onto a porous medium such as silica gel. Thermodynamic data on the adsorption of dichlorodifluoromethane (R12), chlorodifluoromethane (R22), chloropentafluoroethane (R115), 1,1-difluoroethane (R152a), and 1,1,1,2-tetrafluoroethane (R134a) on silica gel are required for the design of recovery units. The results are presented here.

Near azeotropic mixture substitute

NASA Technical Reports Server (NTRS)

Jones, Jack A. (Inventor)

1996-01-01

The present invention comprises a refrigerant mixture consisting of a first mole fraction of 1,1,1,2-tetrafluoroethane (R134a) and a second mole fraction of a component selected from the group consisting of a mixture of CHClFCF.sub.3 (R124) and CH.sub.3 CClF.sub.2 (R142b); a mixture of CHF.sub.2 CH.sub.3 (R152a) and CHClFCF.sub.3 (R124); a mixture of CHF.sub.2 CH.sub.3 (R152a) and CH.sub.3 CClF.sub.2 (R142b); and a mixture of CHClFCF.sub.3 (R124), CH.sub.3 CClF.sub.2 (R142b) and CHF.sub.2 CH.sub.3 (R152a).

Involvement of the CasK/R two-component system in optimal unsaturation of the Bacillus cereus fatty acids during low-temperature growth.

PubMed

Diomandé, Sara Esther; Nguyen-the, Christophe; Abee, Tjakko; Tempelaars, Marcel H; Broussolle, Véronique; Brillard, Julien

2015-11-20

Bacillus cereus sensu lato is composed of a set of ubiquitous strains including human pathogens that can survive a range of food processing conditions, grow in refrigerated food, and sometimes cause food poisoning. We previously identified the two-component system CasK/R that plays a key role in cold adaptation. To better understand the CasK/R-controlled mechanisms that support low-temperature adaptation, we performed a transcriptomic analysis on the ATCC 14579 strain and its isogenic ∆casK/R mutant grown at 12°C. Several genes involved in fatty acid (FA) metabolism were downregulated in the mutant, including desA and desB encoding FA acyl-lipid desaturases that catalyze the formation of a double-bond on the FA chain in positions ∆5 and ∆10, respectively. A lower proportion of FAs presumably unsaturated by DesA was observed in the ΔcasK/R strain compared to the parental strain while no difference was found for FAs presumably unsaturated by DesB. Addition of phospholipids from egg yolk lecithin rich in unsaturated FAs, to growth medium, abolished the cold-growth impairment of ΔcasK/R suggesting that exogenous unsaturated FAs can support membrane-level modifications and thus compensate for the decreased production of these FAs in the B. cereus ∆casK/R mutant during growth at low temperature. Our findings indicate that CasK/R is involved in the regulation of FA metabolism, and is necessary for cold adaptation of B. cereus unless an exogenous source of unsaturated FAs is available. Copyright © 2015 Elsevier B.V. All rights reserved.

Experimental Investigation of COP Using Hydro Carbon Refrigerant in a Domestic Refrigerator

NASA Astrophysics Data System (ADS)

Peyyala, Anusha; Sudheer, N. V. V. S., Dr

2017-08-01

Under the Montreal protocol 1987 researchers worked on the possibility of alternative refrigerants like Hydroflourocarbon’s [HFC’s] and Hydrocarbon’s[HC’s] to replace refrigerants Chloroflourocarbon’s [CFC’s] and Hydrochlorofluorocarbons [HCFC’s] in air-conditioning and cooling systems that are destroying the ozone layer. On October 15, 2016 one hundred and ninety plus countries including India came to an agreement called Kigali Amendment to phase out potent green house gases by 2045 there by preventing 0.5 C rise in global temperature by 2050. Under this agreement India agreed to a timeline to reduce the use of HFC’s by 85% of their baseline by 2045. HFC’s are a family of greenhouse gases that are largely used in refrigerators and air conditioners which have reduced the Ozone Depleting Potential [ODP] but increased the Global Warming Potential [GWP]. Refrigeration and its applications are important in almost all branches of industry, so engineers have to become aware of its principles, uses and limitations. Since the decade there are major changes in the choice of refrigerants due to environmental factors. This issue is on-going and new developments should be developed to decrease the environmental problems. So the aim of this paper is to present the experimental analysis of Coefficient of performance [COP] values using R134a [HFC] & R600a [HC] as Refrigerants in Domestic refrigerator using conventional and nonconventional energy sources. Based on the results, usage of R600a in domestic refrigerators will reduce the ODP and also GWP problems which fulfills the nominal requirements of human beings without any effects.

Rapid Production of Mixed-Base Hydrogen Peroxide by Direct-Contact Liquefied Nitrogen Evaporation; Process Design, Scale-Up, and Validation

DTIC Science & Technology

2004-01-01

phase in November 1996. 1-2. BASIC HYDROGEN PEROXIDE In the early COIL work, either potassium hydroxide (KOH) or sodium hydroxide (NaOH) was the base of...the candidate refrigerants include: R22, R404a, R134a, carbon dioxide, and ammonia. 2-3-3. Surface Evaporator To improve the heat transfer efficiency...monohydrate (LiOH.H20), sodium hydroxide (NaOH), and potassium hydroxide (KOH). The use of solids allows numerous variations of blending sequence and heat

Investigation of saturated critical heat flux in a single, uniformly heated microchannel

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wojtan, Leszek; Revellin, Remi; Thome, John R.

2006-08-15

A series of tests have been performed to determine the saturated critical heat flux (CHF) in 0.5 and 0.8mm internal diameter microchannel tubes as a function of refrigerant mass velocity, heated length, saturation temperature and inlet liquid subcooling. The tested refrigerants were R-134a and R-245fa and the heated length of microchannel was varied between 20 and 70mm. The results show a strong dependence of CHF on mass velocity, heated length and microchannel diameter but no influence of liquid subcooling (2-15{sup o}C) was observed. The experimental results have been compared to the well-known CHF single-channel correlation of Y. Katto and H.more » Ohno [An improved version of the generalized correlation of critical heat flux for the forced convective boiling in uniformly heated vertical tubes, Int. J. Heat and Mass Transfer 27 (9) (1984) 1641-1648] and the multichannel correlation of W. Qu and I. Mudawar [Measurement and correlation of critical heat flux in two-phase microchannel heat sinks, Int. J. Heat and Mass Transfer 47 (2004) 2045-2059]. The comparison shows that the correlation of Katto-Ohno predicts microchannel data with a mean absolute error of 32.8% with only 41.2% of the data falling within a +/-15% error band. The correlation of Qu and Mudawar shows the same trends as the CHF data but significantly overpredicts them. Based on the present experimental data, a new microscale version of the Katto-Ohno correlation for the prediction of CHF during saturated boiling in microchannels has been proposed. (author)« less

Characterization of RPC operation with new environmental friendly mixtures for LHC application and beyond

NASA Astrophysics Data System (ADS)

Guida, R.; Capeans, M.; Mandelli, B.

2016-07-01

The large muon trigger systems based on Resistive Plate Chambers (RPC) at the LHC experiments are currently operated with R134a based mixture. Unfortunately R134a is considered a greenhouse gas with high impact on the enviroment and therefore will be subject to regulations aiming in strongly reducing the available quantity on the market. The immediat effects might be instability on the price and incertitude in the product availability. Alternative gases (HFO-1234yf and HFO-1234ze) have been already identified by industry for specific applications as replacement of R134a. Moreover, HFCs similar to the R134a but with lower global warming potential (GWP) are already available (HFC-245fa, HFC-32, HFC-152a). The present contribution describes the results obtained with RPCs operated with new enviromemtal friendly gases. A particular attention has been addressed to the possibility of maintening the current operation conditions (i.e. currently used applied voltage and front-end electronics) in order to be able to use a new mixture for RPC systems even where the common infrastructure (i.e. high voltage and detector components) cannot be replaced for operation at higher applied voltages.

Modeling and testing of fractionation effects with refrigerant blends in an actual residential heat pump system

DOE Office of Scientific and Technical Information (OSTI.GOV)

Biancardi, F.R.; Pandy, D.R.; Sienel, T.H.

1997-12-31

The heating, ventilating, and air-conditioning (HVAC) industry is actively evaluating and testing hydrofluorocarbon (HFC) refrigerant blends as a means of complying with current and impending national and international environmental regulations restricting the use and disposal of conventional chlorofluorocarbon (CFC) and hydrochlorofluorocarbon (HCFC) refrigerants that contribute to the global ozone-depletion effects. While analyses and system performance tools have shown that HFC refrigerant blends offer certain performance, capacity, and operational advantages, there are significant possible service and operational issues that are raised by the use of blends. Many of these issues occur due to the fractionation of the blends. Therefore, the objectivemore » of this program was to conduct analyses and experimental tests aimed at understanding these issues, develop approaches or techniques to predict these effects, and convey to the industry safe and reliable approaches. As a result, analytical models verified by laboratory data have been developed that predict the fractionation effects of HFC refrigerant blends (1) when exposed to selected POE lubricants, (2) during the system charging process from large liquid containers, and (3) during system start-up, operation, and shutdown within various system components (where two-phase refrigerant exists) and during selected system and component leakage scenarios. Model predictions and experimental results are presented for HFC refrigerant blends containing R-32, R-134a, and R-125 and the data are generalized for various operating conditions and scenarios.« less

Interaction of temperature, humidity, driver preferences, and refrigerant type on air conditioning compressor usage.

PubMed

Levine, C; Younglove, T; Barth, M

2000-10-01

Recent studies have shown large increases in vehicle emissions when the air conditioner (AC) compressor is engaged. Factors that affect the compressor-on percentage can have a significant impact on vehicle emissions and can also lead to prediction errors in current emissions models if not accounted for properly. During 1996 and 1997, the University of California, Riverside, College of Engineering-Center for Environmental Research and Technology (CE-CERT) conducted a vehicle activity study for the California Air Resources Board (CARB) in the Sacramento, CA, region. The vehicles were randomly selected from all registered vehicles in the region. As part of this study, ten vehicles were instrumented to collect AC compressor on/off data on a second-by-second basis in the summer of 1997. Temperature and humidity data were obtained and averaged on an hourly basis. The ten drivers were asked to complete a short survey about AC operational preferences. This paper examines the effects of temperature, humidity, refrigerant type, and driver preferences on air conditioning compressor activity. Overall, AC was in use in 69.1% of the trips monitored. The compressor was on an average of 64% of the time during the trips. The personal preference settings had a significant effect on the AC compressor-on percentage but did not interact with temperature. The refrigerant types, however, exhibited a differential response across temperature, which may necessitate separate modeling of the R12 refrigerant-equipped vehicles from the R134A-equipped vehicles. It should be noted that some older vehicles do get retrofitted with new compressors that use R134A; however, none of the vehicles in this study had been retrofitted.

Testing of refrigerant mixtures in residential heat pumps. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Judge, J.F.; Radermacher, R.

1995-08-01

To contribute to finding the proper substitute for R-22, a test facility was designed and built to measure the steady state and cyclic performance of two air-to-air heat pumps of 2 & 3 refrigeration-ton (RT) capacity. The performance of heat pumps is evaluated based on ASHRAE Standard 116-1983 {open_quotes}Method of Testing for Seasonal Efficiency of Unitary Air-conditioners and Heat Pumps{close_quotes} (47). This standard includes six steady-state tests; three cooling tests (A, B, and C) and three heating tests (High Temperature (47S), Frost Accumulation (35F), and Low Temperature (17L)). The standard also includes two cyclic tests; a cyclic cooling test (D)more » and a cyclic heating test (47C). The results of these tests are used to evaluate the seasonal performance of a heat pump. In the work presented here, two heat pumps (test units) are used. Test unit 1 is a 2 RT split heat pump system using a reciprocating compressor, a short tube, and a thermostatic expansion valve. Test unit 2 is a 3 RT split heat pump system using a scroll compressor and two thermostatic expansion valves. This study investigates four different possibilities for replacing R-22 with R-32/125/134a (30/10/60 wt.%) (Mixture 1) or R-32/125/134a (23/25/52 wt.%) (Mixture 2). The first and simplest scenario is the retrofit with no hardware modifications. The second possibility investigated is altering the refrigerant path to attain a near-counterflow configuration in the indoor coil for the heating mode. The third and most complex possibility is the soft optimization which consists of maximizing the COPs of R-22 and Mixture 2 in the heating and cooling modes by optimizing refrigerant charge and expansion devices. The fourth option investigated is the suction-line heat exchange (SLHX). In unit 1, the first, second, and third scenarios are investigated and in unit 2, the first, second, and fourth scenarios are investigated.« less

Theoretical analysis for condensation heat transfer of binary refrigerant mixtures with annular flow in horizontal mini-tubes

NASA Astrophysics Data System (ADS)

Zhang, Hui-Yong; Li, Jun-Ming; Sun, Ji-Liang; Wang, Bu-Xuan

2016-01-01

A theoretical model is developed for condensation heat transfer of binary refrigerant mixtures in mini-tubes with diameter about 1.0 mm. Condensation heat transfer of R410A and R32/R134a mixtures at different mass fluxes and saturated temperatures are analyzed, assuming that the phase flow pattern is annular flow. The results indicate that there exists a maximum interface temperature at the beginning of condensation process for azeotropic and zeotropic mixtures and the corresponding vapor quality to the maximum value increases with mass flux. The effects of mass flux, heat flux, surface tension and tube diameter are analyzed. As expected, the condensation heat transfer coefficients increase with mass flux and vapor quality, and increase faster in high vapor quality region. It is found that the effects of heat flux and surface tension are not so obvious as that of tube diameter. The characteristics of condensation heat transfer of zeotropic mixtures are consistent to those of azeotropic refrigerant mixtures. The condensation heat transfer coefficients increase with the concentration of the less volatile component in binary mixtures.

A combined power and ejector refrigeration cycle for low temperature heat sources

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zheng, B.; Weng, Y.W.

A combined power and ejector refrigeration cycle for low temperature heat sources is under investigation in this paper. The proposed cycle combines the organic Rankine cycle and the ejector refrigeration cycle. The ejector is driven by the exhausts from the turbine to produce power and refrigeration simultaneously. A simulation was carried out to analyze the cycle performance using R245fa as the working fluid. A thermal efficiency of 34.1%, an effective efficiency of 18.7% and an exergy efficiency of 56.8% can be obtained at a generating temperature of 395 K, a condensing temperature of 298 K and an evaporating temperature ofmore » 280 K. Simulation results show that the proposed cycle has a big potential to produce refrigeration and most exergy losses take place in the ejector. (author)« less

Application of magnetic resonance imaging to the investigation of the diffusivity of 1,1,1,2-tetrafluorethane in two polymers.

PubMed

Mayele, M; Oellrich, L R

2004-03-01

In order to evaluate the suitability of a polymer as a sealing material for certain working fluids used in process plants, information about the fluid diffusivity into the polymer or the polymer permeability to the fluid is a prerequisite. The fluid of interest in the present work is 1,1,1,2-tetrafluorethane, CH(2)FCF(3), a partly fluorinated hydrocarbon (HFC) commonly known as refrigerant R134a. HFCs are increasingly used in refrigeration, air conditioning, and heat pump applications as substitutes for the chlorofluorocarbons (CFCs) or hydrochlorofluorocarbons (HCFCs) that are believed to be responsible for ozone depletion in the stratosphere. The polymers studied were FPM, a perfluoroelastomer, and EPDM, an ethylene-propylene-diene rubber. The study was carried out using magnetic resonance imaging (MRI). The contact time dependence of diffusion of the fluid into the polymer, as well as the spatial distributions of spin-lattice, T(1), and spin-spin, T(2), relaxation times, were used as indicators of the influence of the EPDM matrix on the mobility of R134a molecules.

Apparatus of the Vapor-pressure Measurements for Natural Refrigerants

NASA Astrophysics Data System (ADS)

Higuchi, Satoru; Higashi, Yukihiro

An apparatus for measuring the vapor-pressures was newly designed and constructed in order to make the basic thermodynamic properties for environmentally acceptable refrigerants clear. The temperature of sample fluid was measured with 100Ω platinum resistance thermometer calibrated against ITS-90 using a 25Ω standard platinum resistance thermometer. With respect to the pressure measurement, two kinds of presure transducer were adopted. One is a diaphragm semi-conductor strain pressure transducer with the uncertainty of ±0.09%. This pressure transducer was calibrated against quartz crystal pressure transducer with the uncertainty of ±0.01% after every series of experiments. Another is a quartz crystal pressure transducer with the uncertainty of ±0.01%. A quartz crystal pressure transducer was calibrated against the dead weight pressure gauge and barometer. The vapor-pressures for R-32, R-134a, R-290 (propane), R-600a (iso-butane) and n-pentane were measured in the temperature range between273.15 and 323.15K. As the results of vapor-pressure measurements, the reliability of the experimental apparatus as well as the reproducibility of the experimental data were confirmed. In addition, coefficients of Antoine vapor pressure equation were determined from the experimental data. Normal boiling points for environmentally acceptable refrigerants were also determined with high accuracy.

Analysis of hybrid interface cooling system using air ventilation and nanofluid

NASA Astrophysics Data System (ADS)

Rani, M. F. H.; Razlan, Z. M.; Bakar, S. A.; Desa, H.; Wan, W. K.; Ibrahim, I.; Kamarrudin, N. S.; Bin-Abdun, Nazih A.

2017-09-01

The hybrid interface cooling system needs to be designed for maintaining the electric vehicle's battery cell temperature at 25°C. The hybrid interface cooling system is a combination of two individual systems, where the primary cooling system (R-134a) and the secondary cooling system (CuO + Water) will be used to absorb the heat generated by the battery cells. The ventilation system is designed using air as the medium to transfer the heat from the batteries to the refrigeration system (R-134a). Research will focus on determining the suitable compressor displacement, the heat exchanger volume and the expansion valve resistance value. The analysis for the secondary cooling system is focused on the cooling coil where low temperature nanofluid is passing through each interval of the battery cells. For analysing purposes, the thermal properties of the mixture of 50 grams, Copper (II) Oxide and the base fluid have been determined. The hybrid interface cooling system are able to achieve 57.82% increments in term of rate of heat transfer as compared to the individual refrigeration system.

Enhancing the performance of the domestic refrigerator with hot gas injection to suction line

NASA Astrophysics Data System (ADS)

Berman, E. T.; Hasan, S.; Mutaufiq

2016-04-01

The purpose of this study was to determine the increase in performance of a domestic refrigerator that uses hot gas injection (IHG) to the suction line. The experiment was conducted by flowing refrigerant from the discharge line to the suction line. To get performance data, measurements performed on the liquid brine as cooling load with various temperatures (range from 3°C to - 3°C). The working fluid is used as a cooling medium is R-134a. The experimental results showed that the injection of hot gas to the suction line generates an increase in the coefficient of performance systems (COPs) of 7% and is able to lower the discharge temperature, causing the compressor to work lighter/easier, saving electric power needed by the refrigerator.

Elastohydrodynamic Lubrication with Polyolester Lubricants and HFC Refrigerants, Final Report, Volume 2

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gunsel, Selda; Pozebanchuk, Michael

1999-04-01

Lubrication properties of refrigeration lubricants were investigated in high pressure nonconforming contacts under different conditions of temperature, rolling speed, and refrigerant concentration. The program was based upon the recognition that the lubrication regime in refrigeration compressors is generally elastohydrodynamic or hydrodynamic, as determined by the operating conditions of the compressor and the properties of the lubricant. Depending on the compressor design, elastohydrodynamic lubrication conditions exist in many rolling and sliding elements of refrigeration compressors such as roller element bearings, gears, and rotors. The formation of an elastohydrodynamic film separating rubbing surfaces is important in preventing the wear and failure ofmore » compressor elements. It is, therefore, important to predict the elastohydrodynamic (EHD) performance of lubricants under realistic tribocontact renditions. This is, however, difficult as the lubricant properties that control film formation are critically dependent upon pressure and shear, and cannot be evaluated using conventional laboratory instruments. In this study, the elastohydrodynamic behavior of refrigeration lubricants with and without the presence of refrigerants was investigated using the ultrathin film EHD interferometry technique. This technique enables very thin films, down to less than 5 nm, to be measured accurately within an EHD contact under realistic conditions of temperature, shear, and pressure. The technique was adapted to the study of lubricant refrigerant mixtures. Film thickness measurements were obtained on refrigeration lubricants as a function of speed, temperature, and refrigerant concentration. The effects of lubricant viscosity, temperature, rolling speed, and refrigerant concentration on EHD film formation were investigated. From the film thickness measurements, effective pressure-viscosity coefficients were calculated. The lubricants studied in this project included two naphthenic mineral oils (NMO), four polyolesters (POE), and two polyvinyl ether (PVE) fluids. These fluids represented viscosity grades of ISO 32 and ISO 68 and are shown in a table. Refrigerants studied included R-22, R-134a, and R-410A. Film thickness measurements were conducted at 23 C, 45 C, and 65 C with refrigerant concentrations ranging from zero to 60% by weight.« less

Parametric and working fluid analysis of a combined organic Rankine-vapor compression refrigeration system activated by low-grade thermal energy.

PubMed

Saleh, B

2016-09-01

The potential use of many common hydrofluorocarbons and hydrocarbons as well as new hydrofluoroolefins, i.e. R1234yf and R1234ze(E) working fluids for a combined organic Rankine cycle and vapor compression refrigeration (ORC-VCR) system activated by low-grade thermal energy is evaluated. The basic ORC operates between 80 and 40 °C typical for low-grade thermal energy power plants while the basic VCR cycle operates between 5 and 40 °C. The system performance is characterized by the overall system coefficient of performance (COPS) and the total mass flow rate of the working fluid for each kW cooling capacity ([Formula: see text]). The effects of different working parameters such as the evaporator, condenser, and boiler temperatures on the system performance are examined. The results illustrate that the maximum COPS values are attained using the highest boiling candidates with overhanging T-s diagram, i.e. R245fa and R600, while R600 has the lowest [Formula: see text] under the considered operating conditions. Among the proposed candidates, R600 is the best candidate for the ORC-VCR system from the perspectives of environmental issues and system performance. Nevertheless, its flammability should attract enough attention. The maximum COPS using R600 is found to reach up to 0.718 at a condenser temperature of 30 °C and the basic values for the remaining parameters.

Assessment of Environmentally Friendly Refrigerants for Window Air Conditioners

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bansal, Pradeep; Shen, Bo

This paper presents technical assessment of environmentally friendly refrigerants for window air conditioners that currently use refrigerant R410A for residential and commercial applications. The alternative refrigerants that are studied for its replacement include R32, R600a, R290, R1234yf, R1234ze and a mixture of R32 (90% molar concentration) and R125 (10% molar concentration). Baseline experiments were performed on a window unit charged with R410A. The ORNL Heat Pump Design Model was calibrated with the baseline data and was used to assess the comparative performance of the WAC with alternative refrigerants. The paper discusses the advantages and disadvantages of each refrigerants and theirmore » suitability for window air conditioners.« less

Investigating performance of microchannel evaporators for automobile air conditioning with different port structures

NASA Astrophysics Data System (ADS)

Zhou, Guoliang; Su, Lin; Cheng, Qia; Wu, Longbing

2017-08-01

Microchannel evaporator has been widely applied in automobile air conditioning, while it faces the problem of refrigerant maldistribution which deteriorates the thermal performance of evaporator. In this study, the performances of microchannel evaporators with different port structures are experimentally investigated for purpose of reducing evaporator pressure drop. Four evaporator samples with different port number and hydraulic diameter are made for this study. The performances of the evaporator samples are tested on a psychometric calorimeter test bench with the refrigerant R-134A at a real automobile air conditioning. The results on the variations of the evaporator pressure drop and evaporator surface temperature distribution are presented and analyzed. By studying the performance of an evaporator, seeking proper port structure is an approach to reduce refrigerant pressure drop as well as improve refrigerant distribution.

Study of condensation of refrigerants in a micro-channel for development of future compact micro-channel condensers

NASA Astrophysics Data System (ADS)

Chowdhury, Sourav

2009-12-01

Mini- and micro-channel technology has gained considerable ground in the recent years in industry and is favored due to its several advantages stemming from its high surface to volume ratio and high values of proof pressure it can withstand. Micro-channel technology has paved the way to development of highly compact heat exchangers with low cost and mass penalties. In the present work, the issues related to the sizing of compact micro-channel condensers have been explored. The considered designs encompass both the conventional and MEMS fabrication techniques. In case of MEMS-fabricated micro-channel condenser, wet etching of the micro-channel structures, followed by bonding of two such wafers with silicon nitride layers at the interface was attempted. It was concluded that the silicon nitride bonding requires great care in terms of high degree of surface flatness and absence of roughness and also high degree of surface purity and thus cannot be recommended for mass fabrication. Following this investigation, a carefully prepared experimental setup and test micro-channel with hydraulic diameter 700 mum and aspect ratio 7:1 was fabricated and overall heat transfer and pressure drop aspects of two condensing refrigerants, R134a and R245fa were studied at a variety of test conditions. To the best of author's knowledge, so far no data has been reported in the literature on condensation in such high aspect ratio micro-channels. Most of the published experimental works on condensation of refrigerants are concerning conventional hydraulic diameter channels (> 3mm) and only recently some experimental data has been reported in the sub-millimeter scale channels for which the surface tension and viscosity effects play a dominant role and the effect of gravity is diminished. It is found that both experimental data and empirically-derived correlations tend to under-predict the present data by an average of 25%. The reason for this deviation could be because a high aspect ratio channel tends to collect the condensate in the corners of its cross-section leaving only a thin liquid film on the flat side surfaces for better heat transfer than in circular or low aspect ratio channels.

History of the Field Artillery School. Volume 2. World War II

DTIC Science & Technology

1946-10-31

1; FAR TC (B)- I AR MD- I 161 All successful candidates rA-9; INF-11 MC - I, transferred~to Class No. TD -1l; ARMD-. AAF-4; 162. FAPTC M-).4; FA1RTC...FT T brT fUf1 71 -- 4T 4 G Lbug, 8~ 65 2W 1 3 -1"- IT-4P I ’l- -Y -- 44 1f 3c 52 T8 r TOT- 42 ’a- G 2 7 MT~ U’r, Td ~ 41 r - 50 DI 1 41 v 3 4 2...or any other pertinent remarks) lFnlstPd Experience: bei Ia _ ___ -,T- 1tI rh U_ OF ate WIN__ IRS, Admln.ML Unit Grade ___ Dais Map flat Td ftsI Ud

Vaporization inside a mini microfin tube: experimental results and modeling

NASA Astrophysics Data System (ADS)

Diani, A.; Rossetto, L.

2015-11-01

This paper proposes a comparison among the common R134a and the extremely low GWP refrigerant R1234yf during vaporization inside a mini microfin tube. This microfin tube has an internal diameter of 2.4 mm, it has 40 fins, with a fin height of 0.12 mm. Due to the high heat transfer coefficients shown by this tube, this technology can lead to a refrigerant charge reduction. Tests were run in the Heat Transfer in Micro Geometries Lab of the Dipartimento di Ingegneria Industriale of the Università di Padova. Mass velocities range between 375 and 940 kg m-2 s-1, heat fluxes from 10 to 50 kW m-2, vapour qualities from 0.10 to 0.99, at a saturation temperature of 30°C. The comparison among the two fluids is proposed at the same operating conditions, in order to highlight the heat transfer and pressure drop differences among the two refrigerants. In addition, two correlations are proposed to estimate the heat transfer coefficient and frictional pressure drop during refrigerant flow boiling inside mini microfin tubes. These correlations well predict the experimental values, and thus they can be used as a useful tool to design evaporators based on these mini microfin tubes.

The characteristics of welded joints for air conditioning application

NASA Astrophysics Data System (ADS)

Weglowski, M. St.; Weglowska, A.; Miara, D.; Kwiecinski, K.; Błacha, S.; Dworak, J.; Rykala, J.; Pikula, J.; Ziobro, G.; Szafron, A.; Zimierska-Nowak, P.; Richert, M.; Noga, P.

2017-10-01

In the paper the results of metallographic examination of welded joints for air-conditioning elements are presented. The European directives 2006/40/EC on the greenhouse gasses elimination demand to stop using traditional refrigerant and to change it to R744 (CO2) medium in air conditioning installation. The R744 refrigerant is environmental friendly medium if compared with standard solution such as R12, R134a or R1234yf and safer for passengers than R1234yf. The non-standard thermodynamic parameters of the R744 which translate into high pressure and high temperature require specific materials to develop the shape and to specify the technology of manufacturing for the particular elements of the conduits and moreover the technologies of joining for the whole structure, which would meet the exploitation requirements of the new air-conditioning system. To produce the test welded joints of stainless steels four different joining technologies were applied: laser welding, plasma welding, electron beam welding as well as high speed rotation welding. This paper describes the influence of the selected welding process on the macrostructure and microstructure of welded joints of AISI 304 and AISI 316L steels. The results indicated that plasma welding laser welding and electron beam welding technologies guaranty the proper quality of welded joints and can be used for the air conditioning application in automotive industry. However, high speed rotation welding not guarantee the good quality of welded joints and cannot be used for above application.

Starmerella reginensis f.a., sp. nov. and Starmerella kourouensis f.a., sp. nov., isolated from flowers in French Guiana.

PubMed

Amoikon, Tiemele Laurent Simon; Grondin, Cécile; Djéni, Théodore N'Dédé; Jacques, Noémie; Casaregola, Serge

2018-05-21

Analysis of yeasts isolated from various biotopes in French Guiana led to the identification of two strains isolated from flowers and designated CLIB 1634 T and CLIB 1707 T . Comparison of the D1/D2 domain of the large subunit (LSU D1/D2) rRNA gene sequences of CLIB 1634 T and CLIB 1707 T to those in the GenBank database revealed that these strains belong to the Starmerella clade. Strain CLIB 1634 T was shown to diverge from the closely related Starmerella apicola type strain CBS 2868 T with a sequence divergence of 1.34 and 1.30 %, in the LSU D1/D2 rRNA gene and internal transcribed spacer (ITS) sequences respectively. Strain CLIB 1634 T and Candida apicola CBS 2868 T diverged by 3.81 and 14.96 % at the level of the protein-coding gene partial sequences EF-1α and RPB2, respectively. CLIB 1707 T was found to have sequence divergence of 3.88 and 9.16 % in the LSU D1/D2 rRNA gene and ITS, respectively, from that of the most closely related species Starmerella ratchasimensis type strain CBS 10611 T . The species Starmerella reginensis f.a., sp. nov. and Starmerella kourouensis f.a., sp. nov. are proposed to accommodate strains CLIB 1634 T (=CBS 15247 T ) and CLIB 1707 T (=CBS 15257 T ), respectively.

Drying R-407C and R-410A refrigerant blends with molecular sieve desiccants

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cohen, A.P.; Tucker, D.M.

1998-10-01

The hydrofluorocarbon (HFC) R-32 (CF{sub 2}H{sub 2}) is a component of refrigerant blends in the 407 and 410 series being tested and commercialized for use as replacements for R-502 and the hydrochlorofluorocarbon (HCFC) R-22. The molecular sieve desiccants used with chlorofluorocarbon (CFC) and HCFC mineral oil systems in the past have achieved high water capacity by excluding the refrigerant and adsorbing only the water. Unfortunately, R-32 is adsorbed on commercial type 3A molecular sieve desiccant products. The result of this adsorption is a loss of water capacity when drying R-32 compared to drying R-22 or R-502 and a reduced levelmore » of chemical compatibility of the desiccant with the refrigerant. Some compressor manufacturers are seeking a water concentration as low as 10 mg/kg (ppm[wt]) in the circulating refrigerant of polyolester-lubricated refrigerating equipment using these HFC blends. This paper compares unmodified commercial type 3A molecular sieve desiccants with a recently developed, modified 3A molecular sieve that excludes R-32. The modified 3A has better chemical compatibility with R-32 and high water capacity in liquid R-407C and R-410A. The drying rates of the two desiccants in R-407C and R-410A are similar. Data and test methods are reported on refrigerant adsorption, water capacity, drying rate, and chemical compatibility.« less

Evaluation of Alternative Refrigerants for Mini-Split Air Conditioners

DOE Office of Scientific and Technical Information (OSTI.GOV)

Abdelaziz, Omar; Shrestha, Som S

The phase-out of hydrochlorofluorocarbons (HCFC) refrigerants in developing countries is currently underway according to the Montreal Protocol. R-22 is one of the most commonly used HCFCs in the developing nations. It is extremely well suited for air conditioning and refrigeration (AC&R) in high ambient temperature environments. Non-Article 5 countries have already gone through the phase-out of HCFCs and settled on using R-410A as the refrigerant of choice for AC applications. Previous studies have shown that R-410A results in significant capacity and performance degradation at higher ambient temperature conditions. As such, there is a growing concern on finding alternative refrigerants tomore » R-22 that would have zero ODP, lower GWP, and at the same time maintain acceptable performance at higher ambient temperatures. Furthermore, the developed world s transition through higher global warming potential (GWP) refrigerants like HFC and HFC blends resulted in significant direct CO2 equivalent emissions. It is imperative to develop a bridge for developing nations to avoid the transition from HCFC to HFC and then from HFC to alternative lower GWP refrigerants. This paper summarizes data from an experimental campaign on alternative refrigerant evaluation for R-22 and R-410A substitutes for mini-split air conditioners designed for high ambient environments. The experimental evaluation was performed according to ANSI/ASHRAE Standard 37 and the performance was rated at test conditions specified by ANSI/AHRI 210-240 and ISO 5151. Additional tests were conducted at outdoor ambient temperatures of 52 C (125.6 F) and 55 C (131 F) to evaluate their performance at high ambient conditions. Alternative refrigerants, some of which are proprietary, included R-444B, DR-3, N-20b, ARM-20b, R-290, and DR-93 as alternatives to R-22 and R-32, DR-55, L41-2, ARM-71A, and HPR-2A as alternatives to R-410A. The units performances were first verified using the baseline refrigerant and then drop-in refrigerant evaluation followed including soft optimization to ensure refrigerant performance is adequately represented. The soft optimization included: 1) charge optimization, 2) lubricant change, and 3) flow control. The paper presents the relative performances (efficiency and capacity) of the alternative refrigerants compared to the baseline refrigerants at the different operating conditions. Paper concludes with remarks about the suitability of alternative refrigerants for R-22 and R-410A applications in high ambient temperature regions.« less

Experimental comparison between R409A and R437A performance in a heat pump unit

NASA Astrophysics Data System (ADS)

Duarte, M. V.; Pires, L. C.; Silva, P. D.; Gaspar, P. D.

2017-04-01

This paper reports an experimental comparison between the use of the refrigerants R409A and R437A in a heat pump unit designed and developed to work with R12. Although the use of both refrigerants in new equipments were abolished in EU and US according the new F-Gas Regulation of EU and SNAP, they still being used as options for R12 in old equipments, especially in developing countries. Both refrigerants were studied for the same test conditions, according to two groups of tests: group A (variation of the heat source temperature) and group B (variation of refrigerant flow rate). The results obtained showed that the R437A presents a higher discharge pressure and a lower discharge temperature. The heating and cooling capacities of both refrigerants were similar, as well as the exergetic efficiency. For the group A of tests the COP of both refrigerants was similar and for the group B of tests the R409A presented an average COP 15% higher. According to the results obtained it is recommended the use of R409A in old equipments (as transition refrigerant) until the acquisition of equipments operating with refrigerants with low-GWP becomes technically and economic feasible.

Model validations for low-global warming potential refrigerants in mini-split air-conditioning units

DOE PAGES

Shen, Bo; Shrestha, Som; Abdelaziz, Omar

2016-09-02

To identify low GWP (global warming potential) refrigerants to replace R-22 and R-410A, extensive experimental evaluations were conducted for multiple candidates of refrigerant at the standard test conditions and at high-ambient conditions with outdoor temperature varying from 27.8 C to 55.0 C.. In the study, R-22 was compared to propane (R-290), DR-3, ARM-20B, N-20B and R-444B in a mini-split air conditioning unit originally designed for R-22; R-410A was compared to R-32, DR-55, ARM-71A, L41-2 (R-447A) in a mini-split unit designed for R-410A. To reveal physics behind the measured performance results, thermodynamic properties of the alternative refrigerants were analysed. In addition,more » the experimental data was used to calibrate a physics-based equipment model, i.e. ORNL Heat Pump Design Model (HPDM). The calibrated model translated the experimental results to key calculated parameters, i.e. compressor efficiencies, refrigerant side two-phase heat transfer coefficients, corresponding to each refrigerant. As a result, these calculated values provide scientific insights on the performance of the alternative refrigerants and are useful for other applications beyond mini-split air conditioning units.« less

Model validations for low-global warming potential refrigerants in mini-split air-conditioning units

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shen, Bo; Shrestha, Som; Abdelaziz, Omar

To identify low GWP (global warming potential) refrigerants to replace R-22 and R-410A, extensive experimental evaluations were conducted for multiple candidates of refrigerant at the standard test conditions and at high-ambient conditions with outdoor temperature varying from 27.8 C to 55.0 C.. In the study, R-22 was compared to propane (R-290), DR-3, ARM-20B, N-20B and R-444B in a mini-split air conditioning unit originally designed for R-22; R-410A was compared to R-32, DR-55, ARM-71A, L41-2 (R-447A) in a mini-split unit designed for R-410A. To reveal physics behind the measured performance results, thermodynamic properties of the alternative refrigerants were analysed. In addition,more » the experimental data was used to calibrate a physics-based equipment model, i.e. ORNL Heat Pump Design Model (HPDM). The calibrated model translated the experimental results to key calculated parameters, i.e. compressor efficiencies, refrigerant side two-phase heat transfer coefficients, corresponding to each refrigerant. As a result, these calculated values provide scientific insights on the performance of the alternative refrigerants and are useful for other applications beyond mini-split air conditioning units.« less

Polybasic esters: Novel synthetic lubricants designed for use in HFC compressors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lilje, K.C.; Sabahi, M.; Hamid, S.

1995-12-31

The replacement of ozone-depleting refrigerants with ozone-friendly hydrofluorocarbons (HFCs) requires the use of lubricants that have not historically been used in refrigeration compressors and systems. Polyalkylene glycol (PAG) and polyol ester (POE) lubricants have been extensively evaluated in various refrigeration applications and are being used commercially. Novel synthetic lubricants have been developed based on polybasic esters (PBEs) resulting from malonate-acrylate Michael adducts. These lubricants were designed to address problems encountered in current HFC systems. PBE-based fluids show desired miscibility with R-134a and other HFC blends, excellent hydrolytic stability, no copper plating (even in wet systems), and excellent lubricity. All ofmore » these properties are obtained without the use of performance-enhancing additives. Key physical property data, bench and compressor test results, and compatibility study results will be presented.« less

Instantaneous Optical Wall-Temperature of Vertical Two-Phase Annular Flow

NASA Astrophysics Data System (ADS)

Fehring, Brian; Livingston-Jha, Simon; Morse, Roman; Chan, Jason; Doherty, James; Brueggeman, Colby; Nellis, Gregory; Dressler, Kristofer; Berson, ArganthaëL.; Multiphase Flow Visualization; Analysis Laboratory at University of Wisconsin-Madison Team

2017-11-01

We present a non-invasive optical technique for measuring the instantaneous temperature at the inner wall of a flow duct. The technique is used to characterize a fully-developed vertical annular flow of R245fa refrigerant. The test section includes transparent heating windows made of glass coated with fluorine-doped tin-oxide. A 15 mW helium-neon laser is directed through a prism mounted on one of the glass windows and reflected off of the interface between the 150-micron-thick liquid film and the inside wall of the testing section window. The intensity of the laser light reflected at the liquid film-window interface depends on the index of refraction of liquid R245fa, which itself depends on the temperature of the fluid. The intensity of the reflected light is measured using a photodiode and calibrated to a light reflectance model based on the Fresnel equations and Snell's law. Instantaneous temperature data is combined with optical liquid film thickness measurements to calculate the local instantaneous heat transfer coefficient at the wall.

Experimental analysis of R134a flow boiling inside a 5 PPI copper foam

NASA Astrophysics Data System (ADS)

Diani, A.; Mancin, S.; Rossetto, L.

2014-04-01

Heat dissipation is one of the most important issues for the reliability of electronic equipment. Boiling can be a very efficient heat transfer mechanism when used to face with the electronic technology needs of efficient and compact heat sinks. Recently, cellular structured materials both stochastic and periodic, particularly open cell metal foams, have been proposed as possible enhanced surfaces to lower the junction temperatures at high heat fluxes. Up today, most of the research on metal foams only regards single phase flow, whereas the two phase flow is still almost unexplored. This paper presents an experimental study on the heat transfer of R134a during flow boiling inside a 5 PPI (Pores Per linear Inch) copper foam, which is 5 mm high, 10 mm wide and 200 mm long, and it is brazed on a 10 mm thick copper plate. The experimental measurements were carried out by imposing three different heat fluxes (50, 75, and 100 kW m-2) and by varying the refrigerant mass velocity between 50 and 200 kg m-2 s-1 and the vapour quality from 0.2 to 0.90, at constant saturation temperature (30°C). The effects of the refrigerant mass flow rate, heat flux and vapour quality on the heat transfer coefficient, dry out phenomenon, and pressure drop are studied.

R245fa Flow Boiling inside a 4.2 mm ID Microfin Tube

NASA Astrophysics Data System (ADS)

Longo, G. A.; Mancin, S.; Righetti, G.; Zilio, C.

2017-11-01

This paper presents the R245fa flow boiling heat transfer and pressure drop measurements inside a mini microfin tube with internal diameter at the fin tip of 4.2 mm, having 40 fins, 0.15 mm high with a helix angle of 18°. The tube was brazed inside a copper plate and electrically heated from the bottom. Sixteen T-type thermocouples are located in the copper plate to monitor the wall temperature. The experimental measurements were carried out at constant mean saturation temperature of 30 °C, by varying the refrigerant mass velocity between 100 kg m-2 s-1 and 300 kg m-2 s-1, the vapour quality from 0.15 to 0.95, at two different heat fluxes: 30 and 60 kW m-2. The experimental results are presented in terms of two-phase heat transfer coefficient, onset dryout vapour quality, and frictional pressure drop. Moreover, the experimental measurements are compared against the most updated models for boiling heat transfer coefficient and frictional pressure drop estimations available in the open literature for microfin tubes.

Performance of R-410A Alternative Refrigerants in a Reciprocating Compressor Designed for Air Conditioning Applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shrestha, Som S; Vineyard, Edward Allan; Mumpower, Kevin

In response to environmental concerns raised by the use of refrigerants with high Global Warming Potential (GWP), the Air-Conditioning, Heating, and Refrigeration Institute (AHRI) has launched an industry-wide cooperative research program, referred to as the Low-GWP Alternative Refrigerants Evaluation Program (AREP), to identify and evaluate promising alternative refrigerants for major product categories. After successfully completing the first phase of the program in December 2013, AHRI launched a second phase of the Low-GWP AREP in 2014 to continue research in areas that were not previously addressed, including refrigerants in high ambient conditions, refrigerants in applications not tested in the first phase,more » and new refrigerants identified since testing for the program began. Although the Ozone Depletion Potential of R-410A is zero, this refrigerant is under scrutiny due to its high GWP. Several candidate alternative refrigerants have already demonstrated low global warming potential. Performance of these low-GWP alternative refrigerants is being evaluated for Air conditioning and heat pump applications to ensure acceptable system capacity and efficiency. This paper reports the results of a series of compressor calorimeter tests conducted for the second phase of the AREP to evaluate the performance of R-410A alternative refrigerants in a reciprocating compressor designed for air conditioning systems. It compares performance of alternative refrigerants ARM-71A, L41-1, DR-5A, D2Y-60, and R-32 to that of R-410A over a wide range of operating conditions. The tests showed that, in general, cooling capacities were slightly lower (except for the R-32), but energy efficiency ratios (EER) of the alternative refrigerants were comparable to that of R-410A.« less

Analysis and optimization of three main organic Rankine cycle configurations using a set of working fluids with different thermodynamic behaviors

NASA Astrophysics Data System (ADS)

Hamdi, Basma; Mabrouk, Mohamed Tahar; Kairouani, Lakdar; Kheiri, Abdelhamid

2017-06-01

Different configurations of organic Rankine cycle (ORC) systems are potential thermodynamic concepts for power generation from low grade heat. The aim of this work is to investigate and optimize the performances of the three main ORC systems configurations: basic ORC, ORC with internal heat exchange (IHE) and regenerative ORC. The evaluation for those configurations was performed using seven working fluids with typical different thermodynamic behaviours (R245fa, R601a, R600a, R227ea, R134a, R1234ze and R1234yf). The optimization has been performed using a genetic algorithm under a comprehensive set of operative parameters such as the fluid evaporating temperature, the fraction of flow rate or the pressure at the steam extracting point in the turbine. Results show that there is no general best ORC configuration for all those fluids. However, there is a suitable configuration for each fluid. Contribution to the topical issue "Materials for Energy harvesting, conversion and storage II (ICOME 2016)", edited by Jean-Michel Nunzi, Rachid Bennacer and Mohammed El Ganaoui

Max Tech Efficiency Electric HPWH with low-GWP Halogenated Refrigerant

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nawaz, Kashif; Shen, Bo; Elatar, Ahmed F.

A scoping-level analysis was conducted to determine the maximum performance of an electric heat pump water heater (HPWH) with low GWP refrigerants (hydroflouroolefins (HFO), hydrofluorocarbons (HFC), and blends). A baseline heat pump water heater (GE GeoSpring) deploying R-134a was analyzed first using the DOE/ORNL Heat Pump Design Model (HPDM) modeling tool. The model was calibrated using experimental data to match the water temperature stratification in tank, first hour rating, energy factor and coefficient of performance. A CFD modeling tool was used to further refine the HPDM tank model. After calibration, the model was used to simulate the performance of alternativemore » refrigerants. The parametric analysis concluded that by appropriate selection of equipment size and condenser tube wrap configuration the overall performance of emerging low GWP refrigerants for HPWH application not only exceed the Energy Star Energy Factor criteria i.e. 2.20, but is also comparable to some of the most efficient products in the market.« less

Achievement of lipid targets with the combination of rosuvastatin and fenofibric Acid in patients with type 2 diabetes mellitus.

PubMed

Rosenson, Robert S; Carlson, Dawn M; Kelly, Maureen T; Setze, Carolyn M; Hirshberg, Boaz; Stolzenbach, James C; Williams, Laura A

2011-02-01

The objective of this study was to assess the proportion of patients with type 2 diabetes mellitus (T2DM) attaining individual and combined targets of low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), triglycerides (TG), non-HDL-C, and apolipoprotein B (ApoB) after treatment with rosuvastatin (R) + fenofibric acid (FA) compared with corresponding-dose R monotherapy. This post hoc analysis evaluated data from the T2DM subset of patients with mixed dyslipidemia (LDL-C ≥130 mg/dL, HDL-C <40/50 mg/dL in men/women, and TG ≥150 mg/dL) from 2 randomized studies. Patients included in the analysis (N = 456) were treated with R (5, 10, or 20 mg), FA 135 mg, or R (5, 10, or 20 mg) + FA 135 mg for 12 weeks. Attainment of LDL-C <100 mg/dL, HDL-C >40/50 mg/dL in men/women, TG <150 mg/dL, non-HDL-C <130 mg/dL, ApoB <90 mg/dL, and the combined targets of these parameters was assessed. Treatment with R + FA resulted in a significantly higher proportion of patients achieving optimal levels of HDL-C (46.8% vs. 20.8%, P = 0.009 for R 10 mg + FA), TG (60.0% vs. 34.0%, P = 0.02 for R 10 mg + FA; 54.0% vs. 26.4%, P = 0.005 for R 20 mg + FA), non-HDL-C (55.1% vs. 36.4%, P = 0.04 for R 5 mg + FA), ApoB (58.0% vs. 36.4%, P = 0.02 for R 5 mg + FA); and the combined targets of LDL-C, HDL-C, and TG (28.3% vs. 8.3%, P = 0.02 for R 10 mg + FA) and all 5 parameters (26.1% vs. 8.3%, P = 0.03 for R 10 mg + FA) than corresponding-dose R monotherapies. A significantly greater proportion of T2DM patients achieved individual and combined lipid targets when treated with the combination of R + FA than corresponding-dose R monotherapies.

Horizontal convective boiling of R448A, R449A, and R452B within a micro-fin tube

PubMed Central

KEDZIERSKI, MARK A.; KANG, DONGGYU

2017-01-01

This article presents local convective boiling measurements in a micro-fin tube for three low global warming potential refrigerants: R448A, R449A, and R452B1. An existing correlation was modified to predict multi-component mixtures, which predicted 98% of the measurements to within ±20%. The new correlation was used to compare the heat transfer coefficient of the three test fluids at the same heat flux, saturated refrigerant temperature, and refrigerant mass flux. The resulting comparison showed that refrigerant R452B exhibited the highest heat transfer, in large part due to its approximately 28% larger liquid thermal conductivity and smaller temperature glide as compared to the tested low-global warming potential refrigerants. For the example case, the heat transfer coefficient for R449A was approximately 8% larger than that for R448A, while the heat transfer coefficient for R452B was more than 59% larger than either R448A or R449A. The heat transfer coefficients for R448A and R449A were roughly between 26 and 48% less than that of R404A for the example case. In contrast, the model predicts that the R452B heat transfer coefficient was approximately 13% larger than that of R404A for the same conditions. PMID:28758148

Low Global Warming Potential Refrigerants for Commercial Refrigeration Systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fricke, Brian A.; Sharma, Vishaldeep; Abdelaziz, Omar

Supermarket refrigeration systems account for approximately 50% of supermarket energy use, placing this class of equipment among the highest energy consumers in the commercial building domain. In addition, the commonly used refrigeration system in supermarket applications is the multiplex direct expansion (DX) system, which is prone to refrigerant leaks due to its long lengths of refrigerant piping. This leakage reduces the efficiency of the system and increases the impact of the system on the environment. The high Global Warming Potential (GWP) of the hydrofluorocarbon (HFC) refrigerants commonly used in these systems, coupled with the large refrigerant charge and the highmore » refrigerant leakage rates leads to significant direct emissions of greenhouse gases into the atmosphere. Environmental concerns are driving regulations for the heating, ventilating, air-conditioning and refrigeration (HVAC&R) industry towards lower GWP alternatives to HFC refrigerants. Existing lower GWP refrigerant alternatives include hydrocarbons, such as propane (R-290) and isobutane (R-600a), as well as carbon dioxide (R-744), ammonia (R-717), and R-32. In addition, new lower GWP refrigerant alternatives are currently being developed by refrigerant manufacturers, including hydrofluoro-olefin (HFO) and unsaturated hydrochlorofluorocarbon (HCFO) refrigerants. The selection of an appropriate refrigerant for a given refrigeration application should be based on several factors, including the GWP of the refrigerant, the energy consumption of the refrigeration system over its operating lifetime, and leakage of refrigerant over the system lifetime. For example, focusing on energy efficiency alone may overlook the significant environmental impact of refrigerant leakage; while focusing on GWP alone might result in lower efficiency systems that result in higher indirect impact over the equipment lifetime. Thus, the objective of this Collaborative Research and Development Agreement (CRADA) between Honeywell and the Oak Ridge National Laboratory (ORNL) is to develop a Life Cycle Climate Performance (LCCP) modeling tool for optimally designing HVAC&R equipment with lower life cycle greenhouse gas emissions, and the selection of alternative working fluids that reduce the greenhouse gas emissions of HVAC&R equipment. In addition, an experimental evaluation program is used to measure the coefficient of performance (COP) and refrigerating capacity of various refrigerant candidates, which have differing GWP values, in commercial refrigeration equipment. Through a cooperative effort between industry and government, alternative working fluids will be chosen based on maximum reduction in greenhouse gases at minimal cost impact to the consumer. This project will ultimately result in advancing the goals of reducing greenhouse gas emissions through the use of low GWP working fluids and technologies for HVAC&R and appliance equipment, resulting in cost-competitive products and systems.« less

Exploring Capabilities of Electrical Capacitance Tomography Sensor and Velocity Analysis of Two-Phase R-134A Flow Through a Sudden Expansion

DTIC Science & Technology

2017-05-01

SUDDEN EXPANSION 5a. CONTRACT NUMBER In-house 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 62203F 6. AUTHOR(S) Joseph Michael Cronin 5d. PROJECT ...heat transfer in order to manage the ever-increasing airframe and engine heat loads. Two-phase liquid-vapor refrigerant systems are one solution for...were compared with pressure drop correlations. 15. SUBJECT TERMS thermal management , two-phase flow, flow visualization, electric capacitance

MicroRNA-134 regulates lung cancer cell H69 growth and apoptosis by targeting WWOX gene and suppressing the ERK1/2 signaling pathway

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen, Tianjun; Gao, Fei; Feng, Sifang

2015-08-28

MicroRNAs have been shown to act as crucial modulators during carcinogenesis. Recent studies have implied that miR-134 expression associated with epithelial-to-mesenchymal transition phenotype and invasive potential of NSCLC cells. Our study investigated the pathogenic implications of miR-134 in small cell lung cancer (SCLC). Overexpression or inhibition MiR-134 expression by miR-134 mimics or miR-134 inhibitors (anti-miR-134) in SCLC cell lines was detected using qRT-PCR. Lactate dehydrogenase (LDH) assay, MTT assays and flow cytometry were performed in order to clarify the growth and apoptosis of SCLC cells which had been transfected with miR-134 mimics or anti-miR-134. WWOX expression in H69 cells wasmore » detected by qRT-PCR and western blot, respectively. The results showed that overexpression miR-134 was significantly promoting SCLC cells growth and inhibit its apoptosis. In addition, reduced miR-134 expression was significantly correlated with cell growth inhibition and apoptosis promotion. Furthermore, transfection of miR-134 mimics into the SCLC cells markedly down-regulated the level of WWOX, whereas, anti-miR-134 up-regulated WWOX expression. We also found that overexpression WWOX attenuate miR-134 induced H69 cells growth, and promote cell apoptosis. Moreover, miR-134 promoted cell proliferation and inhibit apoptosis via the activation of ERK1/2 pathway. These findings suggest that miR-134 may be an ideal diagnostic and prognostic marker, and may be attributed to the molecular therapy of SCLC. - Highlights: • MiR-134 play roles in small cell lung cancer cell growth and apoptosis. • MiR-134 negative regulated the level of WWOX in H69 cells. • WWOX overexpression attenuate miR-134 induced H69 cells growth. • MiR-134 promotes cell growth via the activation of ERK1/2 pathway.« less

An experimental investigation of ejector performance based upon different refrigerants

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen, S.L.; Yen, J.Y.; Huang, M.C.

1998-12-31

This article experimentally compares the characteristics of different refrigerants as the working fluid in an ejector cooling system. The study covers common refrigerants including R-113, R-114, R-142b, and R-718. The critical choking conditions against the variation of condenser back pressure, the evaporator pressure, and the generator pressure are determined for each refrigerant. The results are compiled into a convenient performance curve and COP chart. These results can serve as an important reference for future design of ejector cooling systems. Finally, this paper presents a comparison of the performances of different refrigerants in an ejector cooling system.

Flow Regime Identification of Horizontal Two Phase Refrigerant R-134a Flow Using Neural Networks (Postprint)

DTIC Science & Technology

2013-11-01

Flows in Microchannels ," Heat Transfer Engineering, Vol. 27, No. 9, 2006, pp. 4-19. 2Kandlikar, S. G., " Heat Transfer Mechanisms During Flow...Boiling in Microchannels ," Journal of Heat Transfer , Vol. 126, No. 1, 2004, pp. 8-16. 3Kreitzer, P. J., Byrd, L., and Willebrand, B. J., "Initial...an integral aspect of modeling two phase flows as most pressure drop and heat transfer correlations rely on a priori knowledge of the flow regime for

Flow, stock, and impact assessment of refrigerants in the Japanese household air conditioner sector.

PubMed

Xue, Mianqiang; Kojima, Naoya; Machimura, Takashi; Tokai, Akihiro

2017-05-15

Refrigerants provide society with great benefits while have the potential to cause adverse effects on the environment and human health. The present study estimated time-dependent flows and stocks and assessed the effects of refrigerants (R-22, R-410a, and R-32) in household air conditioners in Japan. It was found that stock of R-22 and R-410a peaked at 49,147t in 2000 and 55,994t in 2017, respectively. The largest flow of R-22 and R-410a to waste phase occurred at 3417t/yr. in 2005 and 4011t/yr. in 2023, respectively. The total global warming potential (GWP) due to refrigerant emissions increased from 3.6kt CO 2 eq. in 1952 to 6999kt CO 2 eq. in 2019, and then decreased to 5314kt CO 2 eq. in 2030. The ozone depletion potential (ODP) peaked at 141t CFC-11 eq. in 2002. When substituting R-410a for R-22, the ODP decreased 50% while the GDP increased 8%. When substituting R-32 for R-410a, there was no effect on the ODP while the GDP decreased 6%. The human health damage due to the global warming effect of refrigerant emission was much higher than that due to the ozone depleting effect. The refrigerant emission in use and waste management phases dominated the human health damage. The dynamic estimation not only allows us to evaluate the performance of past policies but also supports the future sustainable management associated with the health effects of refrigerants. Copyright © 2017 Elsevier B.V. All rights reserved.

Sealed Gravitational Capillary Viscometry of Dimethyl Ether and Two Next-Generation Alternative Refrigerants

PubMed Central

Cousins, Dylan S.; Laesecke, Arno

2012-01-01

The viscosities of dimethyl ether (DME, C2H6O) and of the fluorinated propene isomers 2,3,3,3-tetrafluoroprop-1-ene (R1234yf, C3H2F4) and trans-1,3,3,3-tetrafluoropropene (R1234ze(E)) were measured in a combined temperature range from 242 K to 350 K at saturated liquid conditions. The instrument was a sealed gravitational capillary viscometer developed at NIST for volatile liquids. Calibration and adjustment of the instrument constant were conducted with n-pentane. The repeatability of the measurements was found to be approximately 1.5 %, leading to a temperature-dependent estimated combined standard uncertainty of the experimental data between 5.7 % at 242 K for dimethyl ether and 2.6 % at 340 K for R1234yf. The measurements were supplemented by ab initio calculations of the molecular size, shape, and charge distributions of the measured compounds. The viscosity results for dimethyl ether were compared with literature data. One other data set measured with a sealed capillary viscometer and exceeding the present results by up to 7 % could be reconciled by applying the vapor buoyancy correction. Then, all data agreed within the estimated uncertainty of the present results. Viscosities for the fluorinated propene isomers deviate up to 4 % from values predicted with the NIST extended corresponding-states model. The viscosities of the two isomers do not scale with their dipole moments. While the measured viscosity of R1234ze(E) with the lower dipole moment is close to that of R134a, the refrigerant to be replaced, that of R1234yf with the higher dipole moment is up to 25 % lower. The viscosity of dimethyl ether is compared with those of water and methanol. PMID:26900526

Performance Optimization of Alternative Lower Global Warming Potential Refrigerants in Mini-Split Room Air Conditioners

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shen, Bo; Abdelaziz, Omar; Shrestha, Som S

Oak Ridge National laboratory (ORNL) recently conducted extensive laboratory, drop-in investigations for lower Global Warming Potential (GWP) refrigerants to replace R-22 and R-410A. ORNL studied propane, DR-3, ARM-20B, N-20B and R-444B as lower GWP refrigerant replacement for R-22 in a mini-split room air conditioner (RAC) originally designed for R-22; and, R-32, DR-55, ARM-71A, and L41-2, in a mini-split RAC designed for R-410A. We obtained laboratory testing results with very good energy balance and nominal measurement uncertainty. Drop-in studies are not enough to judge the overall performance of the alternative refrigerants since their thermodynamic and transport properties might favor different heatmore » exchanger configurations, e.g. cross-flow, counter flow, etc. This study compares optimized performances of individual refrigerants using a physics-based system model tools. The DOE/ORNL Heat Pump Design Model (HPDM) was used to model the mini-split RACs by inputting detailed heat exchangers geometries, compressor displacement and efficiencies as well as other relevant system components. The RAC models were calibrated against the lab data for each individual refrigerant. The calibrated models were then used to conduct a design optimization for the cooling performance by varying the compressor displacement to match the required capacity, and changing the number of circuits, refrigerant flow direction, tube diameters, air flow rates in the condenser and evaporator at 100% and 50% cooling capacities. This paper compares the optimized performance results for all alternative refrigerants and highlights best candidates for R-22 and R-410A replacement.« less

Characterization of FaDu-R, a radioresistant head and neck cancer cell line, and cancer stem cells.

PubMed

Cho, Kwang-Jae; Park, Eun-Ji; Kim, Min-Sik; Joo, Young-Hoon

2018-06-01

The aim of this study was to evaluate the impact of CSC on insensitivity to radiotherapy in HNSCC. A radioresistant cell line, FaDu-R, was established using fractionated ionizing radiation. Cells with high and low CD44/ALDH activity were isolated. FaDu-R cells demonstrated significantly increased cell viability after radiation exposure compared with parental cells. CD44 high /ALDH high FaDu-R cells demonstrated significantly faster wound closure (p<0.05) and more efficient invasion (p<0.05) compared to the CD44 high /ALDH high FaDu cells or the CD44 low /ALDH low FaDu-R cells. There was a significant difference in tumor volume between the CD44 high /ALDH high FaDu-R cells and the CD44 high /ALDH high FaDu cells (p<0.05) as well as the CD44 low /ALDH low FaDu-R cells (p<0.05). Cancer stem cells (CSC) were associated with invasion and tumorigenesis in a radioresistant head and neck squamous cell carcinoma (HNSCC) cell line. This concept might help to improve the understanding of these mechanisms and to develop drugs that can overcome radioresistance during radiotherapy. Copyright © 2017 Elsevier B.V. All rights reserved.

Performance of solar refrigerant ejector refrigerating machine

DOE Office of Scientific and Technical Information (OSTI.GOV)

Al-Khalidy, N.A.H.

1997-12-31

In this work a detailed analysis for the ideal, theoretical, and experimental performance of a solar refrigerant ejector refrigerating machine is presented. A comparison of five refrigerants to select a desirable one for the system is made. The theoretical analysis showed that refrigerant R-113 is more suitable for use in the system. The influence of the boiler, condenser, and evaporator temperatures on system performance is investigated experimentally in a refrigerant ejector refrigerating machine using R-113 as a working refrigerant.

Methods of increasing net work output of organic Rankine cycles for low-grade waste heat recovery with a detailed analysis using a zeotropic working fluid mixture and scroll expander

NASA Astrophysics Data System (ADS)

Woodland, Brandon Jay

An organic Rankine cycle (ORC) is a thermodynamic cycle that is well-suited for waste heat recovery. It is generally employed for waste heat with temperatures in the range of 80 °C -- 300 °C. When the application is strictly to convert waste heat into work, thermal efficiency is not recommended as a key performance metric. In such an application, maximization of the net power output should be the objective rather than maximization of the thermal efficiency. Two alternative cycle configurations that can increase the net power produced from a heat source with a given temperature and flow rate are proposed and analyzed. These cycle configurations are 1) an ORC with two-phase flash expansion and 2) an ORC with a zeotropic working fluid mixture (ZRC). A design-stage ORC model is presented for consistent comparison of multiple ORC configurations. The finite capacity of the heat source and heat sink fluids is a key consideration in this model. Of all working fluids studied for the baseline ORC, R134a and R245fa yield the highest net power output from a given heat source. Results of the design-stage model indicate that the ORC with two-phase flash expansion offers the most improvement over the baseline ORC. However, the level of improvement that could be achieved in practice is highly uncertain due to the requirement of highly efficient two-phase expansion. The ZRC shows improvement over the baseline as long as the condenser fan power requirement is not negligible. At the highest estimated condenser fan power, the ZRC shows the most improvement, while the ORC with flash expansion is no longer beneficial. The ZRC was selected for detailed study because it does not require two-phase expansion. An experimental test rig was used to evaluate baseline ORC performance with R134a and with R245fa. The ZRC was tested on the same rig with a mixture of 62.5% R134a and 37.5% R245fa. The tested expander is a minimally-modified, of-the-shelf automotive scroll compressor. The high performance to cost ratio of this machine lends significant credence to the economic viability of small-scale, low-temperature ORCs. The experimental campaign covered two heat source temperatures, the full range of pump and expander speeds, a full range of heat source and heat sink fluid flow rates, and various charge levels for the three working fluids. This resulted in 366 steady-state measurements. The steady state measurements are used to develop a detailed ORC model. The model is based on multi-fluid performance maps for the pump and expander and a robust moving-boundary heat exchanger model. It is validated against the measured data and predicts the net power output of the tested ORC with a mean absolute percent error of 7.16%. Comparisons made with the detailed model confirm the predictions of the design-stage model. Using a conservative estimate of the condenser fan power, 19.1% improvement of the ZRC over the baseline ORC is indicated for a source temperature of 80 °C. For a 100 °C source temperature, 13.8% improvement is indicated. A key feature of the detailed ORC model is that it calculates the charge inventory of the working fluid in each heat exchanger and line set. Total system charge can also be specified as a model input. The model can represent the total charge well for R134a at low measured charge levels. As the measured charge level increases, the model becomes less accurate. Reasons for the deviation of the model at higher charge are investigated. It is expected that a charge tuning scheme could be employed to improve the accuracy of model-predicted charge.

[Overexpressed miRNA-134b inhibits proliferation and invasion of CD133+ U87 glioma stem cells].

PubMed

Liu, Yifeng; Zhang, Baochao; Wen, Changming; Wen, Gongling; Zhou, Guoping; Zhang, Jingwei; He, Haifa; Wang, Ning; Li, Wei

2017-05-01

Objective To investigate the role of microRNA-134b (miR-134b) in the tumorigenesis of glioma stem cells (GSCs) and the possible molecular mechanism. Methods Real-time quantitative PCR (qRT-PCR) was used to evalate the expression of miR-134b in CD133 + and CD133 - U87 GSCs. A lentiviral vector overexpressing miR-134b in U87 GSCs was constructed, and the effect of miR-134b overexpression on matrix metalloproteinase-2 (MMP-2), MMP-9 and MMP-12 expressions at both mRNA and protein levels were detected by qRT-PCR and Western blotting, respectively. Transwell TM assay was performed to determine the effect of miR-134b overexpression on GSCs invasion ability. Tumor xenograft models in nude mice were established to evaluate the effect of miR-134b overexpression on tumorgenesis in vivo. Results The qRT-PCR showed that, compared with CD133 - cells, miR-134b was significantly down-regulated in CD133 + cells. Cell line over-expressing miR-134b was successfully established, and miR-134b was up-regulated significantly compared with empty vector control. Overexpression of miR-134b remarkably inhibited the invasion of U87 GSCs and the expression of MMP-12. However, overexpression of miR-134b did not affect MMP-2 and MMP-9 expressions. miR-134b also suppressed U87 GSCs xenograft growth in vivo. Tumor volume in tumor xenograft model group was significantly lower than that in control group, and tumor weight decreased by 42% in the former group. Conclusion Overexpression of miR-134b inhibits the growth and invasion of CD133 + GSCs.

Reassessment of the Genetic Regulation of Fatty Acid Synthesis in Escherichia coli: Global Positive Control by the Dual Functional Regulator FadR

PubMed Central

My, L.; Ghandour Achkar, N.; Viala, J. P.

2015-01-01

ABSTRACT In Escherichia coli, the FadR transcriptional regulator represses the expression of fatty acid degradation (fad) genes. However, FadR is also an activator of the expression of fabA and fabB, two genes involved in unsaturated fatty acid synthesis. Therefore, FadR plays an important role in maintaining the balance between saturated and unsaturated fatty acids in the membrane. We recently showed that FadR also activates the promoter upstream of the fabH gene (L. My, B. Rekoske, J. J. Lemke, J. P. Viala, R. L. Gourse, and E. Bouveret, J Bacteriol 195:3784–3795, 2013, doi:10.1128/JB.00384-13). Furthermore, recent transcriptomic and proteomic data suggested that FadR activates the majority of fatty acid (FA) synthesis genes. In the present study, we tested the role of FadR in the expression of all genes involved in FA synthesis. We found that FadR activates the transcription of all tested FA synthesis genes, and we identified the FadR binding site for each of these genes. This necessitated the reassessment of the transcription start sites for accA and accB genes described previously, and we provide evidence for the presence of multiple promoters driving the expression of these genes. We showed further that regulation by FadR impacts the amount of FA synthesis enzymes in the cell. Our results show that FadR is a global regulator of FA metabolism in E. coli, acting both as a repressor of catabolism and an activator of anabolism, two directly opposing pathways. IMPORTANCE In most bacteria, a transcriptional regulator tunes the level of FA synthesis enzymes. Oddly, such a global regulator still was missing for E. coli, which nonetheless is one of the prominent model bacteria used for engineering biofuel production using the FA synthesis pathway. Our work identifies the FadR functional dual regulator as a global activator of almost all FA synthesis genes in E. coli. Because FadR also is the repressor of FA degradation, FadR acts both as a repressor and an activator of the two opposite pathways of FA degradation and synthesis. Our results show that there are still discoveries waiting to be made in the understanding of the genetic regulation of FA synthesis, even in the very well-known bacterium E. coli. PMID:25802297

Response of MiRNA-22-3p and MiRNA-149-5p to Folate Deficiency and the Differential Regulation of MTHFR Expression in Normal and Cancerous Human Hepatocytes

PubMed Central

Li, Chao; Ni, Juan; Liu, Yao-Xian; Wang, Han; Liang, Zi-Qing; Wang, Xu

2017-01-01

Background/Aims Folic acid (FA) is a core micronutrient involved in DNA synthesis/methylation, and the metabolism of FA is responsible for genomic stability. MicroRNAs may affect gene expression during folate metabolism when cellular homeostasis is changed. This study aimed to reveal the relationship between FA deficiency and the expression of miR-22-p/miR-149-5p and the targeted regulation of miR-22-3p/miR-149-5p on the key folate metabolic gene Methylenetetrahydrofolate reductase (MTHFR). Methods Normal (HL-7702 cells) and cancerous (QGY-7703 cells) human hepatocytes were intervened in modified RPMI 1640 with FA deficiency for 21 days. The interaction between MTHFR and the tested miRNAs was verified by Dual-Luciferase Reporter Assays. The changes in the expression of miR-22-3p/miR-149-5p in response to FA deficiency were detected by Poly (A) Tailing RT-qPCR, and the expression of MTHFR at both the transcriptional and translational levels was determined by RT-qPCR and Western blotting, respectively. Result MiR-22-3p/miR-149-5p directly targeted the 3’UTR sequence of the MTHFR gene. FA deficiency led to an upregulation of miR-22-3p/miR-149-5p expression in QGY-7703/HL-7702 cells, while the transcription of MTHFR was decreased in QGY-7703 cells but elevated in HL-7702 cells. Western blotting showed that FA deficiency resulted in a decline of the MTHFR protein in QGY-7703 cells, whereas in HL-7702 cells, the MTHFR protein level remained constant. Conclusion The results suggested that miR-22-3p/miR-149-5p exert different post-transcriptional effects on MTHFR under conditions of FA deficiency in normal and cancerous human hepatocytes. The results also implied that miR-22-3p/miR-149-5p might exert anticancer effects in cases of long-term FA deficiency. PMID:28045918

Experimental investigation of heat transfer of R134a in pool boiling on stainless steel and aluminum tubes

NASA Astrophysics Data System (ADS)

Wengler, C.; Addy, J.; Luke, A.

2018-03-01

Due to high energy demand required for chemical processes, refrigeration and process industries the increase of efficiency and performance of thermal systems especially evaporators is indispensable. One of the possibilities to meet this purpose are investigations in enhancement of the heat transfer in nucleate boiling where high heat fluxes at low superheat are transferred. In the present work, the heat transfer in pool boiling is investigated with pure R134a over wide ranges of reduced pressures and heat fluxes. The heating materials of the test tubes are aluminum and stainless steel. The influence of the thermal conductivity on the heat transfer coefficients is analysed by the surface roughness of sandblasted surfaces. The heat transfer coefficient increases with increasing thermal conductivity, surface roughness and reduced pressures. The experimental results show a small degradation of the heat transfer coefficients between the two heating materials aluminum and stainless steel. In correlation with the VDI Heat Atlas, the experimental results are matching well with the predictions but do not accurately consider the stainless steel material reference properties.

Hsa-miR-134 suppresses non-small cell lung cancer (NSCLC) development through down-regulation of CCND1

PubMed Central

Sun, Cheng-Cao; Li, Shu-Jun; Li, De-Jia

2016-01-01

Hsa-miRNA-134 (miR-134) has recently been discovered to have anticancer efficacy in different organs. However, the role of miR-134 on non-small cell lung cancer (NSCLC) is still ambiguous. In this study, we investigated the role of miR-134 on the development of NSCLC. The results indicated that miR-134 was significantly down-regulated in primary tumor tissues and very low levels were found in NSCLC cell lines. Ectopic expression of miR-134 in NSCLC cell lines significantly suppressed cell growth as evidenced by cell viability assay, colony formation assay and BrdU staining, through inhibition of cyclin D1, cyclin D2, CDK4 and up-regulation of p57(Kip2) and p21(Waf1/Cip1). In addition, miR-134 induced apoptosis, as indicated by concomitantly with up-regulation of key apoptosis protein cleaved caspase-3, and down-regulation of anti-apoptosis protein Bcl2. Moreover, miR-134 inhibited cellular migration and invasiveness through inhibition of matrix metalloproteinases (MMP)-7 and MMP-9. Further, oncogene CCND1 was revealed to be a putative target of miR-134, which was inversely correlated with miR-134 expression in NSCLC. Taken together, our results demonstrated that miR-134 played a pivotal role on NSCLC through inhibiting cell proliferation, migration, invasion, and promoting apoptosis by targeting oncogenic CCND1. PMID:27166267

An experimental study of the flow boiling of refrigerant-based nanofluids

NASA Astrophysics Data System (ADS)

Kolekar, Rahul Dadasaheb

The use of nanofluids for various heat transfer applications has been a topic of intense research over the last decade. A number of studies to evaluate the thermophysical properties and single-phase heat transfer behavior of nanofluids have been reported. The current study is focused on the use of nanofluids in flow boiling applications, with CO2 and R134a used as the base refrigerants. CuO nanoparticles 40nm in size, and TiO2 nanoparticles 200nm in size are used to create partially stable CO2-based nanofluids. Stable nanofluids are created in R134a by mixing it with dispersions of surface-treated nanoparticles in polyolester (POE) oil (RL22H and RL68H). The particles (Al 2O3, ZnO, CuO, and ATO) at particle mass fractions from 0.08% to 1.34%, with particle sizes of 20nm and 40nm are coated with polar and non-polar surface treatments. The thermal properties of R134a-based nanofluids are measured. Thermal conductivity shows limited improvements; the largest increase of 13% is observed with CuO nanoparticles. Significant increases in viscosity, as high as 2147%, are observed due to CuO nanoparticles. Only the ATO nanofluid exhibited a decrease in the measured viscosity. Heat transfer coefficients during flow boiling of nanofluids are measured over a range of mass flux from 100 to 1000 kg/m2s, with a heat flux from 5 to 25kW/m2, and vapor quality up to 1. The test section is a smooth copper tube, 6.23mm in diameter and 1.8m in length. Average decreases of 5% and 28% are observed in heat transfer coefficients during flow boiling of CuO/CO2 and TiO2/CO2 nanofluids, respectively. For the R134a-based nanofluids, average decreases in heat transfer during flow boiling at the highest particle mass fraction are 15% and 22% for Al2O3 and ZnO nanoparticles, respectively. CuO nanoparticles exhibit an average decrease of 7% for particle mass fraction of 0.08%. An average increase of 10% is observed with ATO nanoparticles at a 0.22% mass fraction. Heat transfer performance deteriorates with increase in viscosity and particle number density. The performance is also worse for partially stable nanofluids that modify the test section surface. Modifications to the thermophysical properties is the primary mechanism that affects heat transfer performance during flow boiling of nanofluids; increased thermal conductivity enhances while increased viscosity and surface tension reduce heat transfer in nucleate boiling-dominated flows. A secondary mechanism of nanoparticles filling up the micro-cavities on test surface is also responsible for decreased heat transfer and is a strong function of particle number density.

Reproductive and developmental toxicity of hydrofluorocarbons used as refrigerants.

PubMed

Ema, Makoto; Naya, Masato; Yoshida, Kikuo; Nagaosa, Ryuichi

2010-04-01

The present paper summarizes data on the reproductive and developmental toxicity of hydrofluorocarbons (HFCs), including pentafluoroethane (HFC-125), 1,1,1,2-tetrafluoroethane (HFC-134a), 1,1,1-trifluoroethane (HFC-143a), 1,1-difluoroethane (HFC-152a), difluoromethane (HFC-32) and 1,1,1,3,3-pentafluoropropane (HFC-245fa), used as refrigerants, published in openly available scientific literature. No developmental toxicity of HFC-125 was found even at 50,000 ppm in rats or rabbits. Although HFC-134a exhibited no dominant lethal effect or reproductive toxicity in rats, it caused low body weight in pre- and postnatal offspring and slightly retarded skeletal ossification in fetuses at 50,000 ppm in rats. No maternal or developmental toxicity was noted after exposure to HFC-143a even at 40,000 ppm in rats or rabbits or HFC-152a even at 50,000 ppm in rats. HFC-32 is slightly maternally and developmentally toxic at 50,000 ppm in rats, but not in rabbits. HFC-245fa caused decreases in maternal body weight and food consumption at 10,000 and 50,000 ppm and fetal weight at 50 000ppm. No evidence of teratogenicity for these HFCs was noted in rats or rabbits. There is limited information about the reproductive toxicity of these HFCs. Animal studies remain necessary for risk assessments of chemicals because it is difficult to find alternative methods to determine the toxic effects of chemicals. It is required to reduce emissions of organic vapors containing HFCs to reduce the risk of exposure. Copyright 2009 Elsevier Inc. All rights reserved.

Covalent modification of reduced graphene oxide by means of diazonium chemistry and use as a drug-delivery system.

PubMed

Wei, Guangcheng; Yan, Miaomiao; Dong, Renhao; Wang, Dong; Zhou, Xiangzhu; Chen, Jingfei; Hao, Jingcheng

2012-11-12

Under acidic conditions, reduced graphene oxide (rGO) was functionalized with p-aminobenzoic acid, which formed the diazonium ions through the diazotization with a wet-chemical method. Surfactants or stabilizers were not applied during the diazotization. After the functionalized rGO was treated through mild sonication in aqueous solution, these functionalized rGO sheets were less than two layers, which was determined by atomic force microscopy (AFM) imaging. The water solubility of functionalized rGO after the introduction of polyethyleneimine (PEI) was improved significantly; it was followed by covalent binding of folic acid (FA) molecules to the functionalized rGO to allow us to specifically target CBRH7919 cancer cells by using FA as a receptor. The loading and release behaviors of elsinochrome A (EA) and doxorubicin (DOX) on the functionalized rGO sheets were investigated. The EA loading ratio onto rGO-C(6)H(4)-CO-NH-PEI-NH-CO-FA (abbreviated rGO-PEI-FA, the weight ratio of drug loaded onto rGO-PEI-FA) was approximately 45.56 %, and that of DOX was approximately 28.62 %. It was interesting that the drug release from rGO-PEI-FA was pH- and salt-dependent. The results of cytotoxicity (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and flow cytometry (FCM) assays, as well as cell morphology observations) clearly showed that the concentration of rGO-PEI-FA as the drug-delivery composite should be less than 12.5 mg L(-1). The conjugation of DOX and rGO-PEI-FA can enhance the cancer-cell apoptosis effectively and can also push the cancer cells to the vulnerable G2 phase of the cell cycle, which is most sensitive and susceptible to damage by drugs or radiation. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The comparison of performance by using alternative refrigerant R152a in automobile climate system with different artificial neural network models

NASA Astrophysics Data System (ADS)

Kalkisim, A. T.; Hasiloglu, A. S.; Bilen, K.

2016-04-01

Due to the refrigerant gas R134a which is used in automobile air conditioning systems and has greater global warming impact will be phased out gradually, an alternative gas is being desired to be used without much change on existing air conditioning systems. It is aimed to obtain the easier solution for intermediate values on the performance by creating a Neural Network Model in case of using a fluid (R152a) in automobile air conditioning systems that has the thermodynamic properties close to each other and near-zero global warming impact. In this instance, a network structure giving the most accurate result has been established by identifying which model provides the best education with which network structure and makes the most accurate predictions in the light of the data obtained after five different ANN models was trained with three different network structures. During training of Artificial Neural Network, Quick Propagation, Quasi-Newton, Levenberg-Marquardt and Conjugate Gradient Descent Batch Back Propagation methodsincluding five inputs and one output were trained with various network structures. Over 1500 iterations have been evaluated and the most appropriate model was identified by determining minimum error rates. The accuracy of the determined ANN model was revealed by comparing with estimates made by the Multi-Regression method.

MODELING AND DESIGN STUDY USING HFC-236EA AS AN ALTERNATIVE REFRIGERANT IN A CENTRIFUGAL COMPRESSOR

EPA Science Inventory

The report gives results of an investigation of the operation of a centrifugal compressor--part of a chlorofluorocarbon (CFC)-114 chiller installation--with the new refrigerant hydrofluorocarbon (HFC)-236ea, a proposed alternative to CFC-114. A large set of CFC-236ea operating da...

Diffusion-Tensor Imaging of Thigh Muscles in Duchenne Muscular Dystrophy: Correlation of Apparent Diffusion Coefficient and Fractional Anisotropy Values With Fatty Infiltration.

PubMed

Li, Gui Dian; Liang, Ying Yin; Xu, Ping; Ling, Jian; Chen, Ying Ming

2016-04-01

The purpose of this study is to investigate the correlation of apparent diffusion coefficient (ADC) and fractional anisotropy (FA) values with fatty infiltration in the thigh muscles of patients with Duchenne muscular dystrophy (DMD) using diffusion-tensor imaging (DTI). Twenty-one boys with DMD were recruited. The grade of fatty infiltration and the ADC and FA values of four thigh muscles (rectus femoris, semitendinosus, sartorius, and gracilis) were measured, and the FA and ADC values were compared with the grade of fatty infiltration. Twenty age-matched healthy boys were enrolled as the control group. The differences in the ADC and FA values of the thigh muscles between patients with DMD and the control group were compared. The patients with DMD showed lower FA values and higher ADC values in all measured muscles when compared with the control group. The FA and ADC values were correlated with the grade of fatty infiltration. For the rectus femoris muscle, r = -0.753 and p = 0.007 for FA, and r = 0.685 and p = 0.001 for ADC. For the semitendinosus muscle, r = -0.621 and p = 0.041 for FA, and r = 0.705 and p = 0.021 for ADC. For the sartorius muscle, r = -0.662 and p = 0.027 for FA, and r = 0.701 and p = 0.017 for ADC. For the gracilis muscle, r = -0.618 and p = 0.043 for FA, and r = 0.695 and p = 0.022 for ADC. Damage to the thigh muscles in patients with DMD can be detected by ADC and FA values using DTI. DTI can be used to assess the severity of the disease.

Reducing the Carbon Footprint of Commercial Refrigeration Systems Using Life Cycle Climate Performance Analysis: From System Design to Refrigerant Options

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fricke, Brian A; Abdelaziz, Omar; Vineyard, Edward Allan

In this paper, Life Cycle Climate Performance (LCCP) analysis is used to estimate lifetime direct and indirect carbon dioxide equivalent gas emissions of various refrigerant options and commercial refrigeration system designs, including the multiplex DX system with various hydrofluorocarbon (HFC) refrigerants, the HFC/R744 cascade system incorporating a medium-temperature R744 secondary loop, and the transcritical R744 booster system. The results of the LCCP analysis are presented, including the direct and indirect carbon dioxide equivalent emissions for each refrigeration system and refrigerant option. Based on the results of the LCCP analysis, recommendations are given for the selection of low GWP replacement refrigerantsmore » for use in existing commercial refrigeration systems, as well as for the selection of commercial refrigeration system designs with low carbon dioxide equivalent emissions, suitable for new installations.« less

Study of the Vapor-Liquid Coexistence Curve and the Critical Curve for Nonazeotropic Refrigerant Mixture R152a + R114 System

NASA Astrophysics Data System (ADS)

Kabata, Yasuo; Higashi, Yukihiro; Uematsu, Masahiko; Watanabe, Koichi

Measurements of the vapor-liquid coexistence curve in the critical region for the refrigerant mixture of R152a (CH3CHF2: 1, l-difluoroethane) +R 114 (CCIF2CCIF2 :1, 2-dichloro-1, 1, 2, 2-tetrafluoroethane) system were made by visual observation of the disappearance of the meniscus at the vapor-liquid interface within an optical cell. Forty-eight saturated densities along the vapor-liquid coexistence curve between 204 and 861 kg·m-3 for five different compositions of 10, 20, 50, 80 and 90 wt% R 152a were obtained in the temperature range 370 to 409 K. The experimental errors of temperature, density, and mass fraction were estimated within ±10mK, ±0.5% and +0.05 %, respectively. On the basis of these measurements, the critical parameters of five different compositions for the R 152a +R 114 system were determined in consideration of the meniscus disappearance level as well as intensity of the critical opalescence. In accordance with the previous results of three other refrigerant mixtures, i.e., R 12 +R 22 system, R 22 +R 114 system and R 13B1 + R 114 system, the coexistence curve and critical curve on the temperature-density diagram for binary refrigerant mixtures were discussed. In addition, correlations of its composition dependence for this system were proposed.

Assessment of commercially available energy-efficient room air conditioners including models with low global warming potential (GWP) refrigerants

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shah, N. K.; Park, W. Y.; Gerke, B.

Improving the energy efficiency of room air conditioners (RACs) while transitioning to low global-warming-potential (GWP) refrigerants will be a critical step toward reducing the energy, peak load, and emissions impacts of RACs while keeping costs low. Previous research quantified the benefits of leapfrogging to high efficiency in tandem with the transition to low-GWP refrigerants for RACs (Shah et al., 2015) and identified opportunities for initial action to coordinate energy efficiency with refrigerant transition in economies constituting about 65% of the global RAC market (Shah et al., 2017). This report describes further research performed to identify the best-performing (i.e., most efficientmore » and low-GWP-refrigerant using) RACs on the market, to support an understanding of the best available technology (BAT). Understanding BAT can help support market-transformation programs for high-efficiency and low-GWP equipment such as minimum energy performance standards (MEPS), labeling, procurement, and incentive programs. We studied RACs available in six economies—China, Europe, India, Japan, South Korea, and the United States—that together account for about 70% of global RAC demand, as well as other emerging economies. The following are our key findings: • Highly efficient RACs using low-GWP refrigerants, e.g., HFC-32 (R-32) and HC-290 (R-290), are commercially available today at prices comparable to similar RACs using high-GWP HCFC-22 (R-22) or HFC-410A (R-410A). • High efficiency is typically a feature of high-end products. However, highly efficient, cost-competitive (less than 1,000 or 1,500 U.S. dollars in retail price, depending on size) RACs are available. • Where R-22 is being phased out, high GWP R-410A still dominates RAC sales in most mature markets except Japan, where R-32 dominates. • In all of the economies studied except Japan, only a few models are energy efficient and use low-GWP refrigerants. For example, in Europe, India, and Indonesia, the highest-efficiency RAC models employ the low-GWP refrigerants R-32 or R-290. • RACs are available in most regions and worldwide that surpass the highest efficiency levels recognized by labeling programs. • Fixed-speed RACs using high-GWP and ozone-depleting R-22 refrigerant still dominate the market in many emerging economies. There is significant scope to improve RAC efficiency and transition to low-GWP refrigerants using commercially available technology and to design market-transformation programs for high-efficiency, low-GWP equipment including standards, labeling, procurement, and incentive programs.« less

An R2R3-MYB Transcription Factor Regulates Eugenol Production in Ripe Strawberry Fruit Receptacles1

PubMed Central

Medina-Puche, Laura; Molina-Hidalgo, Francisco Javier; Boersma, Maaike; Schuurink, Robert C.; López-Vidriero, Irene; Solano, Roberto; Franco-Zorrilla, José-Manuel; Caballero, José Luis; Blanco-Portales, Rosario; Muñoz-Blanco, Juan

2015-01-01

Eugenol is a volatile phenylpropanoid that contributes to flower and ripe fruit scent. In ripe strawberry (Fragaria × ananassa) fruit receptacles, eugenol is biosynthesized by eugenol synthase (FaEGS2). However, the transcriptional regulation of this process is still unknown. We have identified and functionally characterized an R2R3 MYB transcription factor (EMISSION OF BENZENOID II [FaEOBII]) that seems to be the orthologous gene of PhEOBII from Petunia hybrida, which contributes to the regulation of eugenol biosynthesis in petals. The expression of FaEOBII was ripening related and fruit receptacle specific, although high expression values were also found in petals. This expression pattern of FaEOBII correlated with eugenol content in both fruit receptacle and petals. The expression of FaEOBII was repressed by auxins and activated by abscisic acid, in parallel to the ripening process. In ripe strawberry receptacles, where the expression of FaEOBII was silenced, the expression of CINNAMYL ALCOHOL DEHYDROGENASE1 and FaEGS2, two structural genes involved in eugenol production, was down-regulated. A subsequent decrease in eugenol content in ripe receptacles was also observed, confirming the involvement of FaEOBII in eugenol metabolism. Additionally, the expression of FaEOBII was under the control of FaMYB10, another R2R3 MYB transcription factor that regulates the early and late biosynthetic genes from the flavonoid/phenylpropanoid pathway. In parallel, the amount of eugenol in FaMYB10-silenced receptacles was also diminished. Taken together, these data indicate that FaEOBII plays a regulating role in the volatile phenylpropanoid pathway gene expression that gives rise to eugenol production in ripe strawberry receptacles. PMID:25931522

Performance analysis of the electric vehicle air conditioner by replacing hydrocarbon refrigerant

NASA Astrophysics Data System (ADS)

Santoso, Budi; Tjahjana, D. D. D. P.

2017-01-01

The thermal comfort in passenger cabins needs an automotive air-conditioning system. The electric vehicle air conditioner system is driven by an electric compressor which includes a compressor and an electric motor. Almost air-conditioning system uses CFC-12, CFC-22 and HFC-134a as refrigerant. However, CFC-12 and CFC-22 will damage the ozone layer. The extreme huge global warming potentials (GWP) values of CFC-12, CFC-22, and HFC-134a represent the serious greenhouse effect of Earth. This article shows new experimental measurements and analysis by using a mixture of HC-134 to replace HFC-134a. The result is a refrigerating effect, the coefficient of performance and energy factor increase along with cooling capacity, both for HFC-134a and HC-134. The refrigerating effect of HC-134 is almost twice higher than HFC-134a. The coefficient of performance value of HC-134 is also 36.42% greater than HFC-134a. Then, the energy factor value of HC-134 is 3.78% greater than HFC-134a.

Dual-objective optimization of organic Rankine cycle (ORC) systems using genetic algorithm: a comparison between basic and recuperative cycles

NASA Astrophysics Data System (ADS)

Hayat, Nasir; Ameen, Muhammad Tahir; Tariq, Muhammad Kashif; Shah, Syed Nadeem Abbas; Naveed, Ahmad

2017-08-01

Exploitation of low potential waste thermal energy for useful net power output can be done by manipulating organic Rankine cycle systems. In the current article dual-objectives (η_{th} and SIC) optimization of ORC systems [basic organic Rankine cycle (BORC) and recuperative organic Rankine cycle (RORC)] has been done using non-dominated sorting genetic algorithm (II). Seven organic compounds (R-123, R-1234ze, R-152a, R-21, R-236ea, R-245ca and R-601) have been employed in basic cycle and four dry compounds (R-123, R-236ea, R-245ca and R-601) have been employed in recuperative cycle to investigate the behaviour of two systems and compare their performance. Sensitivity analyses show that recuperation boosts the thermodynamic behaviour of systems but it also raises specific investment cost significantly. R-21, R-245ca and R-601 show attractive performance in BORC whereas R-601 and R-236ea in RORC. RORC, due to higher total investment cost and operation & maintenance costs, has longer payback periods as compared to BORC.

An experimental evaluation of two nonazeotropic refrigerant mixtures in a water-to-water breadboard heat pump

NASA Astrophysics Data System (ADS)

Kauffeld, Michael; Mulroy, William; McLinden, Mark; Didion, David

1990-02-01

As part of the Department of Energy/Oak Ridge National Laboratory Building Equipment Research program, the National Institute of Standards and Technology constructed an experimental, easily reconfigurable, water-to-water, breadboard heat pump apparatus in order to compare pure R22 to nonazeotropic refrigerant mixtures. Performance of the heat pump charged with a range of compositions of the binary mixtures R22/RI14 and R13/R12 were compared to R22. The advantage claimed for mixtures in this application is improved thermodynamic efficiency as a result of gliding refrigerant temperatures in the evaporator and condenser in low lift, high glide applications typical of air conditioning.

Potential Alternative Lower Global Warming Refrigerants for Air Conditioning in Hot Climates

DOE Office of Scientific and Technical Information (OSTI.GOV)

Abdelaziz, Omar; Shrestha, Som S; Shen, Bo

The earth continues to see record increase in temperatures and extreme weather conditions that is largely driven by anthropogenic emissions of warming gases such as carbon dioxide and other more potent greenhouse gases such as refrigerants. The cooperation of 188 countries in the Conference of the Parties in Paris 2015 (COP21) resulted in an agreement aimed to achieve a legally binding and universal agreement on climate, with the aim of keeping global warming below 2 C. A global phasedown of hydrofluorocarbons (HFCs) can prevent 0.5 C of warming by 2100. However, most of the countries in hot climates are consideredmore » as developing countries and as such are still using R-22 (a Hydrochlorofluorocarbon (HCFC)) as the baseline refrigerant and are currently undergoing a phase-out of R-22 which is controlled by current Montreal Protocol to R-410A and other HFC based refrigerants. These HFCs have significantly high Global Warming Potential (GWP) and might not perform as well as R-22 at high ambient temperature conditions. In this paper we present recent results on evaluating the performance of alternative lower GWP refrigerants for R-22 and R-410A for small residential mini-split air conditioners and large commercial packaged units. Results showed that several of the alternatives would provide adequate replacement for R-22 with minor system modification. For the R-410A system, results showed that some of the alternatives were almost drop-in ready with benefit in efficiency and/or capacity. One of the most promising alternatives for R-22 mini-split unit is propane (R-290) as it offers higher efficiency; however it requires compressor and some other minor system modification to maintain capacity and minimize flammability risk. Between the R-410A alternatives, R-32 appears to have a competitive advantage; however at the cost of higher compressor discharge temperature. With respect to the hydrofluoroolefin (HFO) blends, there existed a tradeoff in performance and system design. It was noticed that higher glide refrigerants benefited the most from operating in the larger packaged unit with an evaporator in a multi-row counter-cross configuration. This study suggests that there is a strong potential for using lower GWP refrigerants to design and operate more efficient air conditioning systems in hot climates.« less

MicroRNA-134 activity in somatostatin interneurons regulates H-Ras localization by repressing the palmitoylation enzyme, DHHC9.

PubMed

Chai, Sunghee; Cambronne, Xiaolu A; Eichhorn, Stephen W; Goodman, Richard H

2013-10-29

MicroRNA-134 (miR-134) serves as a widely accepted model for microRNA function in synaptic plasticity. In this model, synaptic activity stimulates miR-134 expression, which then regulates dendrite growth and spine formation. By using a ratiometric microRNA sensor, we found, unexpectedly, that miR-134 activity in cortical neurons was restricted to interneurons. Using an assay designed to trap microRNA-mRNA complexes, we determined that miR-134 interacted directly with the mRNA encoding the palmitoylation enzyme, DHHC9. This enzyme is known to palmitoylate H-Ras, a modification required for proper membrane trafficking. Treatment with bicuculline, a GABAA receptor antagonist, decreased DHHC9 expression in somatostatin-positive interneurons and membrane localization of an H-Ras reporter in a manner that depended on miR-134. Thus, although miR-134 has been proposed to affect all types of neurons, we showed that functionally active miR-134 is produced in only a selected population of neurons where it influences the expression of targets, such as DHHC9, that regulate membrane targeting of critical signaling molecules.

SYNOPSIS OF THE U.S. ENVIRONMENTAL PROTECTION AGENCY RESIDENTIAL REFRIGERATOR/FREEZER ALTERNATIVE REFRIGERANTS EVALUATION PROGRAM

EPA Science Inventory

The paper is a recapitulation of the experimental testing at the U.S. Environmental Protection Agency's NRMRL's (National Risk Management Research Laboratory's) Air Pollution Prevention and Control Division on residential refrigerator/freezers (R/Fs). R/F testing at the NRMRL lab...

Identification of a Raloxifene Analog That Promotes AhR-Mediated Apoptosis in Cancer Cells.

PubMed

Jang, Hyo Sang; Pearce, Martin; O'Donnell, Edmond F; Nguyen, Bach Duc; Truong, Lisa; Mueller, Monica J; Bisson, William H; Kerkvliet, Nancy I; Tanguay, Robert L; Kolluri, Siva Kumar

2017-12-01

We previously reported that raloxifene, an estrogen receptor modulator, is also a ligand for the aryl hydrocarbon receptor (AhR). Raloxifene induces apoptosis in estrogen receptor-negative human cancer cells through the AhR. We performed structure-activity studies with seven raloxifene analogs to better understand the structural requirements of raloxifene for induction of AhR-mediated transcriptional activity and apoptosis. We identified Y134 as a raloxifene analog that activates AhR-mediated transcriptional activity and induces apoptosis in MDA-MB-231 human triple negative breast cancer cells. Suppression of AhR expression strongly reduced apoptosis induced by Y134, indicating the requirement of AhR for Y134-induced apoptosis. Y134 also induced apoptosis in hepatoma cells without having an effect on cell cycle regulation. Toxicity testing on zebrafish embryos revealed that Y134 has a significantly better safety profile than raloxifene. Our studies also identified an analog of raloxifene that acts as a partial antagonist of the AhR, and is capable of inhibiting AhR agonist-induced transcriptional activity. We conclude that Y134 is a promising raloxifene analog for further optimization as an anti-cancer agent targeting the AhR.

Oil-return characteristics of refrigerant oils in split heat pump system

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sundaresan, S.G.; Radermacher, R.

1996-08-01

Currently, HFC substitute refrigerants for R-22 are being evaluated in air-conditioning and heat pump applications. The oil return characteristics and heat transfer effects of the lubricants are being studied again. Based on commercial refrigeration experience POEs are the lubricants of choice for HFC refrigerants. POEs have two major drawbacks: hygroscopicity and high cost. Thus the question is raised to what extent is it possible to replace POEs with a lower cost, but immiscible, oil such as mineral oil. It is the purpose of this study to experimentally investigate the oil return behavior of R-407C with mineral oil in a splitmore » three-ton heat pump in comparison to R407C/POE and R-22/Mineral Oil.« less

Modeling and design study using HFC-236ea as an alternative refrigerant in a centrifugal compressor. Final report, January 1994-September 1995

DOE Office of Scientific and Technical Information (OSTI.GOV)

Popovic, P.; Shapiro, H.N.

1997-04-01

The Environmental Protection Agency (EPA) in cooperation with the Navy has been seeking a CFC-114 drop-in placement. One alternative HFC refrigerant which appears to satisfy all physical and chemical characteristics for the Navy fleet was found to be HFC-236ea refrigerant. The project represents a part of the investigation directed to evaluate this CFC-114 alternative refrigerant as a possible drop-in replacement in Navy chillers. The objective of the study was to conduct a thorough literature review regarding centrifugal compressors and the, on the basis of the information gathered, build an accurate but simple compressor model utilizing the available compressor experimental data.more » Further, the developed compressor model would be used to suggest eventual design adjustments to enhance compressor performance with the alternative HFC-236ea refrigerant.« less

Testing the CaR-FA-X model: investigating the mechanisms underlying reduced autobiographical memory specificity in individuals with and without a history of depression.

PubMed

Sumner, Jennifer A; Mineka, Susan; Adam, Emma K; Craske, Michelle G; Vrshek-Schallhorn, Suzanne; Wolitzky-Taylor, Kate; Zinbarg, Richard E

2014-08-01

Reduced autobiographical memory specificity (AMS) is an important cognitive phenomenon in major depressive disorder (MDD), but knowledge about mechanisms is lacking. The CaR-FA-X model of Williams and colleagues (2007) proposed that 3 processes contributed to reduce AMS: capture and rumination (CaR), functional avoidance (FA), and impaired executive control (X). However, the entire CaR-FA-X model has not been tested. We addressed this gap in the literature by investigating contributions of the CaR-FA-X mechanisms to reduced AMS, alone or in interaction, in a subset of young adults (N = 439) from the Northwestern-UCLA Youth Emotion Project. Participants were classified as those with (n = 164) and without (n = 275) a history of MDD at AMS assessment. They completed measures of: AMS; rumination (the brooding factor; CaR); childhood, adolescent, and early adulthood adversity (FA); avoidant coping (FA); and verbal fluency (X). Using structural equation modeling, we found greatest support for associations between reduced AMS and the capture and rumination, and impaired executive control mechanisms. In those with and without a history of MDD, brooding and verbal fluency interacted to contribute to reduced AMS. For participants without a history of MDD, lower verbal fluency (indicating impaired executive control) was associated with reduced AMS among those high on brooding. For participants with a history of MDD, lower verbal fluency was associated with reduced AMS among those low on brooding. The first finding was consistent with the CaR-FA-X model but the latter was not. Implications for conceptualizations of reduced AMS and its mechanisms are discussed. (c) 2014 APA, all rights reserved.

Environmentally-Friendly Dense and Porous Geopolymers Using Fly Ash and Rice Husk Ash as Raw Materials

PubMed Central

Ziegler, Daniele; Formia, Alessandra; Tulliani, Jean-Marc; Palmero, Paola

2016-01-01

This paper assesses the feasibility of two industrial wastes, fly ash (FA) and rice husk ash (RHA), as raw materials for the production of geopolymeric pastes. Three typologies of samples were thus produced: (i) halloysite activated with potassium hydroxide and nanosilica, used as the reference sample (HL-S); (ii) halloysite activated with rice husk ash dissolved into KOH solution (HL-R); (iii) FA activated with the alkaline solution realized with the rice husk ash (FA-R). Dense and porous samples were produced and characterized in terms of mechanical properties and environmental impact. The flexural and compressive strength of HL-R reached about 9 and 43 MPa, respectively. On the contrary, the compressive strength of FA-R is significantly lower than the HL-R one, in spite of a comparable flexural strength being reached. However, when porous samples are concerned, FA-R shows comparable or even higher strength than HL-R. Thus, the current results show that RHA is a valuable alternative to silica nanopowder to prepare the activator solution, to be used either with calcined clay and fly ash feedstock materials. Finally, a preliminary evaluation of the global warming potential (GWP) was performed for the three investigated formulations. With the mix containing FA and RHA-based silica solution, a reduction of about 90% of GWP was achieved with respect to the values obtained for the reference formulation. PMID:28773587

Alternative Refrigerant Evaluation for High-Ambient-Temperature Environments: R-22 and R-410A Alternatives for Mini-Split Air Conditioners

DOE Office of Scientific and Technical Information (OSTI.GOV)

Abdelaziz, Omar; Shrestha, Som S.; Munk, Jeffrey D.

The Oak Ridge National Laboratory (ORNL) High-Ambient-Temperature Evaluation Program for low– global warming potential (Low-GWP) Refrigerants aims to develop an understanding of the performance of low-GWP alternative refrigerants to hydrochlorofluorocarbon (HCFC) and hydrofluorocarbon (HFC) refrigerants in mini-split air conditioners under high-ambient-temperature conditions. This final report describes the parties involved, the alternative refrigerant selection process, the test procedures, and the final results.

Properties and Cycle Performance of Refrigerant Blends Operating Near and Above the Refrigerant Critical Point, Task 2: Air Conditioner System Study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Piotr A. Domanski; W. Vance Payne

2002-10-31

The main goal of this project was to investigate and compare the performance of an R410A air conditioner to that of an R22 air conditioner, with specific interest in performance at high ambient temperatures at which the condenser of the R410A system may be operating above the refrigerant's critical point. Part 1 of this project consisted of conducting comprehensive measurements of thermophysical for refrigerant R125 and refrigerant blends R410A and R507A and developing new equation of state formulations and mixture models for predicting thermophysical properties of HFC refrigerant blends. Part 2 of this project conducted performance measurements of split-system, 3-tonmore » R22 and R410A residential air conditioners in the 80 to 135 F (27.8 to 57.2 C) outdoor temperature range and development of a system performance model. The performance data was used in preparing a beta version of EVAP-COND, a windows-based simulation package for predicting performance of finned-tube evaporators and condensers. The modeling portion of this project also included the formulation of a model for an air-conditioner equipped with a thermal expansion valve (TXV). Capacity and energy efficiency ratio (EER) were measured and compared. The R22 system's performance was measured over the outdoor ambient temperature range of 80 to 135 F (27.8 to 57.2 C). The same test range was planned for the R410A system. However, the compressor's safety system cut off the compressor at the 135.0 F (57.2 C) test temperature. The highest measurement on this system was at 130.0 F (54.4 C). Subsequently, a custom-manufactured R410A compressor with a disabled safety system and a more powerful motor was installed and performance was measured at outdoor temperatures up to 155.0 F (68.3 C). Both systems had similar capacity and EER performance at 82.0 F (27.8 C). The capacity and EER degradation of both systems were nearly linearly dependent with rising ambient outdoor ambient test temperatures. The performance degradation of R410A at higher temperatures was greater than R22. However, the R22 and R410A systems both operated normally during all tests. Visual observations of the R410A system provided no indication of vibrations or TXV hunting at high ambient outdoor test conditions with the compressor operating in the transcritical regime.« less

15. 'Southern Pacific R.R., One 236'0' Bet. End Pins S. ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

15. 'Southern Pacific R.R., One 236'-0' Bet. End Pins S. Tr. Thro'. Draw Bridge over Sacramento River at Tehama, The Phoenix Bridge Co., Phoenixville, Pa., Jan'y 19th 98, Dwg. 585.' - Southern Pacific Railroad Shasta Route, Bridge No. 210.52, Milepost 210.52, Tehama, Tehama County, CA

Correlations between impairment, psychological distress, disability, and quality of life in peripheral facial palsy.

PubMed

Díaz-Aristizabal, U; Valdés-Vilches, M; Fernández-Ferreras, T R; Calero-Muñoz, E; Bienzobas-Allué, E; Moracén-Naranjo, T

2017-05-23

This paper analyses the correlations between scores on scales assessing impairment, psychological distress, disability, and quality of life in patients with peripheral facial palsy (PFP). We conducted a retrospective cross-sectional study including 30 patients in whom PFP had not resolved completely. We used tools for assessing impairment (Sunnybrook Facial Grading System [FGS]), psychological distress (Hospital Anxiety and Depression Scale [HADS]), disability (Facial Disability Index [FDI]), and quality of life (Facial Clinimetric Evaluation [FaCE] scale). We found no correlations between FGS and HADS scores, or between FGS and FDI social function scores. However, we did find a correlation between FGS and FDI physical function scores (r=0.54; P<.01), FDI total score (r=0.4; P<.05), FaCE total scores (ρ=0.66; P<.01), and FaCE social function scores (ρ=0.5; P<.01). We also observed a correlation between HADS Anxiety scores and FDI physical function (r=-0.47; P<.01), FDI social function (r=-0.47; P<.01), FDI total (r=-0.55; P<.01), FaCE total (ρ=-0.49; P<.01), and FaCE social scores (ρ=-0.46; P<.05). Significant correlations were also found between HADS Depression scores and FDI physical function (r=-0.61; P<.01), FDI social function (r=-0.53; P<.01), FDI total (r=-0.66; P<.01), FaCE total (ρ=-0.67; P<.01), and FaCE social scores (ρ=-0.68; P<.01), between FDI physical function scores and FaCE total scores (ρ=0.87; P<.01) and FaCE social function (ρ=0.74; P<.01), between FDI social function and FaCE total (ρ=0.66; P<.01) and FaCE social function scores (ρ=0.72; P<.01), and between FDI total scores and FaCE total (ρ = 0,87; P<.01) and FaCE social function scores (ρ=0.84; P<.01). In our sample, patients with more severe impairment displayed greater physical and global disability and poorer quality of life without significantly higher levels of social disability and psychological distress. Patients with more disability experienced greater psychological distress and had a poorer quality of life. Lastly, patients with more psychological distress also had a poorer quality of life. Copyright © 2017 Sociedad Española de Neurología. Publicado por Elsevier España, S.L.U. All rights reserved.

Model-based optimizations of packaged rooftop air conditioners using low global warming potential refrigerants

DOE PAGES

Shen, Bo; Abdelaziz, Omar; Shrestha, Som; ...

2017-10-31

Based on laboratory investigations for R-22 and R-410A alternative low GWP refrigerants in two baseline rooftop air conditioners (RTU), the DOE/ORNL Heat Pump Design Model was used to model the two RTUs and the models were calibrated against the experimental data. We compared the compressor efficiencies and heat exchanger performances. An efficiency-based compressor mapping method was developed. Extensive model-based optimizations were conducted to provide a fair comparison between all the low GWP candidates by selecting optimal configurations. The results illustrate that all the R-22 low GWP refrigerants will lead to slightly lower COPs. ARM-20B appears to be the best R-22more » replacement at normal conditions. At higher ambient temperatures, ARM-20A exhibits better performance. All R-410A low GWP candidates will result in similar or better efficiencies than R-410A. R-32 has the best COP while requiring the smallest compressor. Finally, R-452B uses the closest compressor displacement volume and achieves the same efficiency as R-410A.« less

Model-based optimizations of packaged rooftop air conditioners using low global warming potential refrigerants

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shen, Bo; Abdelaziz, Omar; Shrestha, Som

Based on laboratory investigations for R-22 and R-410A alternative low GWP refrigerants in two baseline rooftop air conditioners (RTU), the DOE/ORNL Heat Pump Design Model was used to model the two RTUs and the models were calibrated against the experimental data. We compared the compressor efficiencies and heat exchanger performances. An efficiency-based compressor mapping method was developed. Extensive model-based optimizations were conducted to provide a fair comparison between all the low GWP candidates by selecting optimal configurations. The results illustrate that all the R-22 low GWP refrigerants will lead to slightly lower COPs. ARM-20B appears to be the best R-22more » replacement at normal conditions. At higher ambient temperatures, ARM-20A exhibits better performance. All R-410A low GWP candidates will result in similar or better efficiencies than R-410A. R-32 has the best COP while requiring the smallest compressor. Finally, R-452B uses the closest compressor displacement volume and achieves the same efficiency as R-410A.« less

Development of a test facility and preliminary testing of flow boiling heat transfer of R410A refrigerant with Al2O3 nanolubricants

NASA Astrophysics Data System (ADS)

Wong, Thiam

In vapor compression cycles, a small portion of the oil circulates with the refrigerant throughout the system components, while most of the oil stays in the compressors. In heat exchangers, the lubricant in excess penalizes the heat transfer and increases the pressure losses: both effects are highly undesired but yet unavoidable. Nanoparticles dispersed in the excess lubricant are expected to provide enhancements in heat transfer. While solubility and miscibility of refrigerants in polyolesters (POE) lubricant are well established knowledge, there is a lack of information regarding if and how nanoparticles dispersed in the lubricant affect these properties. This thesis presents experimental data of solubility of two types of Al2O3 nanolubricants with refrigerant R-410A. The nanoparticles were dispersed in POE lubricant by using different surfactants and dispersion methods. The nanolubricants appeared to have slightly lower solubility than that of R-410A but actually the solid nanoparticles did not really interfere with the POE oil solubility characteristics. A test facility and experimental methodology was developed for the investigation of heat transfer coefficient and pressure drop. The pressure drop of the refrigerant lubricant mixtures during flow boiling depended on the mass flux of the refrigerant. Greater augmentation was seen in the pressure drop results with decreasing mass flow rate. Pure refrigerant R410A showed the lowest pressure drop, addition of nanolubricants to the refrigerant showed a slightly higher pressure drop and POE-refrigerant mixture showed the highest pressure drop in the tests conducted. Enhancement or degradation in heat transfer coefficient during flow boiling depended on the nanoparticle concentration in the lubricant as well as the lubricant concentration in refrigerant. R410A showed the highest heat transfer coefficient for all conditions tested. For a concentration of 1% nanolubricant in refrigerant, the heat transfer coefficient showed more enhancement with increase in nanoparticle concentration compared to POE refrigerant mixtures. For a concentration of 3% nanolubricant in refrigerant mixtures there was little to no enhancement for tests conducted.

A Comparison Between Actual Parts Usage and Parts Usage Projected in Allowance Parts Lists for Forklift Vehicles

DTIC Science & Technology

1976-06-01

CM ^ 7 w 3m Eh E-" S Q CM ^O S >AW CM Q O O GQ O Eh UN OS on< Ph Eh go a: H HH...UNCO CM O O CM O O rH O-CO CM {>-NO <H ONCO-3" CM COcM O- UN rH H rH rH CM ** •• •* r 7 ) Eh O -faX W c/2s-sx<-Sr~^>MEHCO<C £xl <Z fa O S fa s fa s •• rH...4i J>VU v> \\f <u -Q X Pi rxcvi CM fM»M (Moi IMIM OJ !M(V P4 PM m 10 Z IP — up up •• CP • UP< 7 » •* WU« •• U»V> •• w» •• y»y% •• u» •• l/« ••

COMPARISON OF CFC-114 AND HFC-236EA PERFORMANCE IN SHIPBOARD VAPOR COMPRESSION SYSTEMS

EPA Science Inventory

The report gives results of a comparison of the performance of two refrigerants - 1,1,1,2,3,3-hexafluoropropane (HFC-236ea) and 1,2-dichloro-tetrafluoroethane (CFC-114) - in shipboard vapor compression refrigeration systems. (NOTE: In compliance with the Montreal Protocol and Dep...

High dose teriparatide (rPTH1-34) therapy increases callus volume and enhances radiographic healing at 8-weeks in a massive canine femoral allograft model.

PubMed

Nishitani, Kohei; Mietus, Zachary; Beck, Christopher A; Ito, Hiromu; Matsuda, Shuichi; Awad, Hani A; Ehrhart, Nicole; Schwarz, Edward M

2017-01-01

Small animal studies have demonstrated significant high-dose recombinant parathyroid hormone1-34 (rPTH1-34) effects on intercalary allograft healing. Towards a human adjuvant therapy to decrease non-unions, we evaluated rPTH1-34 safety and efficacy in a clinically relevant canine femoral allograft model. Adult female mongrel hounds (n = 20) received a 5cm mid-diaphyseal osteotomy reconstructed with a plated allograft, and were randomized to: 1) Placebo (n = 5; daily saline), 2) Continuous rPTH1-34 (n = 7; 5 μg/kg/day s.c. from day 1-55 post-op), or 3) Delayed rPTH1-34 (n = 8; 5 μg/kg/day s.c. from day 14-28 post-op). Safety was assessed by physical behavior and blood calcium monitoring. Cone beam CT (CB-CT) was performed on days 14, 28 and 56 post-op to assess 2D cortical healing, 3D bone volume, and Union Ratio. Biomechanical testing and dynamic histomorphometry were also performed. The high drug dose was poorly tolerated, as most dogs receiving rPTH1-34 had to be given intravenous saline, and one dog died from hypercalcemia. Continuous rPTH1-34 significantly increased 2D healing and callus volumes at 4-weeks versus Placebo, and sustained the significant increase in cortical union at 8-week (p<0.05). These rPTH1-34 effects were confirmed by histomorphometry, revealing significant increases in mineral apposition rates (MAR) on host bone and graft-host junctions (p<0.05). Delayed rPTH1-34 significantly increased callus volume and MAR at 8 weeks (p<0.05). Although no biomechanical differences were observed, as expected for early healing, the results demonstrated that 2D RUST scoring significantly correlated with torsional biomechanics (p<0.01). In conclusion, 8-weeks of intermittent high-dose rPTH1-34 treatment significantly increases callus formation and accelerates bony union of intercalary massive allografts in a clinically relevant canine model, but with serious side-effects from hypercalcemia.

High dose teriparatide (rPTH1-34) therapy increases callus volume and enhances radiographic healing at 8-weeks in a massive canine femoral allograft model

PubMed Central

Mietus, Zachary; Beck, Christopher A.; Ito, Hiromu; Matsuda, Shuichi; Awad, Hani A.; Ehrhart, Nicole; Schwarz, Edward M.

2017-01-01

Small animal studies have demonstrated significant high-dose recombinant parathyroid hormone1-34 (rPTH1-34) effects on intercalary allograft healing. Towards a human adjuvant therapy to decrease non-unions, we evaluated rPTH1-34 safety and efficacy in a clinically relevant canine femoral allograft model. Adult female mongrel hounds (n = 20) received a 5cm mid-diaphyseal osteotomy reconstructed with a plated allograft, and were randomized to: 1) Placebo (n = 5; daily saline), 2) Continuous rPTH1-34 (n = 7; 5 μg/kg/day s.c. from day 1–55 post-op), or 3) Delayed rPTH1-34 (n = 8; 5 μg/kg/day s.c. from day 14–28 post-op). Safety was assessed by physical behavior and blood calcium monitoring. Cone beam CT (CB-CT) was performed on days 14, 28 and 56 post-op to assess 2D cortical healing, 3D bone volume, and Union Ratio. Biomechanical testing and dynamic histomorphometry were also performed. The high drug dose was poorly tolerated, as most dogs receiving rPTH1-34 had to be given intravenous saline, and one dog died from hypercalcemia. Continuous rPTH1-34 significantly increased 2D healing and callus volumes at 4-weeks versus Placebo, and sustained the significant increase in cortical union at 8-week (p<0.05). These rPTH1-34 effects were confirmed by histomorphometry, revealing significant increases in mineral apposition rates (MAR) on host bone and graft-host junctions (p<0.05). Delayed rPTH1-34 significantly increased callus volume and MAR at 8 weeks (p<0.05). Although no biomechanical differences were observed, as expected for early healing, the results demonstrated that 2D RUST scoring significantly correlated with torsional biomechanics (p<0.01). In conclusion, 8-weeks of intermittent high-dose rPTH1-34 treatment significantly increases callus formation and accelerates bony union of intercalary massive allografts in a clinically relevant canine model, but with serious side-effects from hypercalcemia. PMID:29020057

Evaluation of R-22 alternatives for heat pumps. Report for September 1993-December 1994

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hwang, Y.; Judge, J.F.; Radermacher, R.

1996-03-01

The paper reports results of a study investigating three different possibilities for replacing refrigerant R-22 with R-407C in a heat pump. The first and simplest scenario was a retrofit without any hardware modifications. The second possibility was a modification that required altering the refrigerant path to attain a near-counterflow configuration in the indoor coil for the heating mode. The third and most complex possibility was soft optimization, consisting of maximizing the coefficients for performance (COPs) in the heating and cooling modes by optimizing the refrigerant charge and expansion devices.

Impact of microRNA-134 on neural cell survival against ischemic injury in primary cultured neuronal cells and mouse brain with ischemic stroke by targeting HSPA12B.

PubMed

Chi, Wenying; Meng, Fanjun; Li, Yan; Li, Peilong; Wang, Guizhi; Cheng, Hong; Han, Song; Li, Junfa

2014-12-10

As a newly discovered member of the HSP70 family, heat shock protein A12B (HSPA12B) is involved in brain ischemic injury. According to our previous study, microRNA-134 (miR-134) could target HSPA12B by binding to its 3'-untranslated region (UTR). However, the regulation of miR-134 on HSPA12B and their role in protecting neuronal cells from ischemic injury are unclear. In this study, the miR-134 expression level was manipulated, and the HSPA12B protein levels were also determined in oxygen-glucose deprivation (OGD)-treated primary cultured neuronal cells in vitro and mouse brain after middle cerebral artery occlusion (MCAO)-induced ischemic stroke in vivo. The results showed that miR-134 expression levels increased in primary cultured neuronal cells and mouse brain from 12h to 7 day reoxygenation/reperfusion after 1h OGD or 1h MCAO treatment. miR-134 overexpression promoted neuronal cell death and apoptosis by decreasing HSPA12B protein levels. Conversely, downregulating miR-134 reduced neuronal cell death and apoptosis by enhancing HSPA12B protein levels. Also, HSPA12B siRNA could block miR-134 inhibitor-mediated neuroprotection against OGD-induced neuronal cell injury in vitro. Taken together, miR-134 might influence neuronal cell survival against ischemic injury in primary cultured neuronal cells and mouse brain with ischemic stroke by negatively modulating HSPA12B protein expression in a posttranscriptional manner. Copyright © 2014 Elsevier B.V. All rights reserved.

Alternative Refrigerant Evaluation for High-Ambient Temperature Environments: R-22 and R-410A Alternatives for Mini-Split Air Conditioners

DOE Office of Scientific and Technical Information (OSTI.GOV)

Abdelaziz, Omar; Munk, Jeffrey D.; Shrestha, Som S.

The Oak Ridge National Laboratory (ORNL) High-Ambient Temperature Testing Program for Low-GWP Refrigerants aims to develop an understanding of the performance of low-Global Warming Potential (low-GWP) alternatives to Hydrochlorofluorocarbon (HCFC) and Hydrofluorocarbon (HFC) refrigerants in mini-split air conditioners under high ambient temperature conditions. This interim working paper describes the parties involved, the alternative refrigerants selection process, the test procedures, and the preliminary results.

CO2 Supermarket Refrigeration Systems for Southeast Asia and the USA

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sharma, Vishaldeep; Fricke, Brian A; Bansal, Pradeep

This paper presents a comparative analysis of the annual energy consumption of these refrigeration systems in eighty eight cities from all climate zones in Southeast Asia. Also, the performance of the CO2 refrigeration systems is compared to the baseline R404A multiplex direct expansion (DX) system. Finally, the overall performance of the CO2 refrigeration systems in various climatic conditions in Southeast Asia is compared to that in the United States. For the refrigeration systems investigated, it was found that the Transcritical Booster System with Bypass Compressor (TBS-BC) performs better or equivalent to the R404A multiplex DX system in the northern regionsmore » of Southeast Asia (China and Japan). In the southern regions of Southeast Asia (India, Bangladesh, Burma), the R404A multiplex DX system and the Combined Secondary Cascade (CSC) system performs better than the TBS-BC.« less

Morphine Preconditioning Downregulates MicroRNA-134 Expression Against Oxygen-Glucose Deprivation Injuries in Cultured Neurons of Mice.

PubMed

Meng, Fanjun; Li, Yan; Chi, Wenying; Li, Junfa

2016-07-01

Brain protection by narcotics such as morphine is clinically relevant due to the extensive use of narcotics in the perioperative period. Morphine preconditioning induces neuroprotection in neurons, but it remains uncertain whether microRNA-134 (miR-134) is involved in morphine preconditioning against oxygen-glucose deprivation-induced injuries in primary cortical neurons of mice. The present study examined this issue. After cortical neurons of mice were cultured in vitro for 6 days, the neurons were transfected by respective virus vector, such as lentiviral vector (LV)-miR-control-GFP, LV-pre-miR-134-GFP, LV-pre-miR-134-inhibitor-GFP for 24 hours; after being normally cultured for 3 days again, morphine preconditioning was performed by incubating the transfected primary neurons with morphine (3 μM) for 1 hour, and then neuronal cells were exposed to oxygen-glucose deprivation (OGD) for 1 hour and oxygen-glucose recovery for 12 hours. The neuronal cells survival rate and the amount of apoptotic neurons were determined by MTT assay or TUNEL staining at designated time; and the expression levels of miR-134 were detected using real-time reverse transcription polymerase chain reaction at the same time. The neuronal cell survival rate was significantly higher, and the amount of apoptotic neurons was significantly decreased in neurons preconditioned with morphine before OGD than that of OGD alone. The neuroprotection induced by morphine preconditioning was partially blocked by upregulating miR-134 expression, and was enhanced by downregulating miR-134 expression. The expression of miR-134 was significantly decreased in morphine-preconditioned neurons alone without transfection. By downregulating miR-134 expression, morphine preconditioning protects primary cortical neurons of mice against injuries induced by OGD.

Ferulic Acid Administered at Various Time Points Protects against Cerebral Infarction by Activating p38 MAPK/p90RSK/CREB/Bcl-2 Anti-Apoptotic Signaling in the Subacute Phase of Cerebral Ischemia-Reperfusion Injury in Rats.

PubMed

Cheng, Chin-Yi; Tang, Nou-Ying; Kao, Shung-Te; Hsieh, Ching-Liang

2016-01-01

This study aimed to evaluate the effects of ferulic acid (FA) administered at various time points before or after 30 min of middle cerebral artery occlusion (MCAo) followed by 7 d of reperfusion and to examine the involvement of mitogen-activated protein kinase (MAPK) signaling pathways in the cortical penumbra. FA was intravenously administered to rats at a dose of 100 mg/kg 24 h before ischemia (B-FA), 2 h before ischemia (P-FA), immediately after ischemic insult (I-FA), 2 h after reperfusion (R-FA), or 24 h after reperfusion (D-FA). Our study results indicated that P-FA, I-FA, and R-FA effectively reduced cerebral infarct areas and neurological deficits. P-FA, I-FA, and R-FA significantly downregulated glial fibrillary acidic protein (GFAP), mitochondrial Bax, cytochrome c, and cleaved caspase-3 expression, and effectively restored the phospho-p38 MAPK (p-p38 MAPK)/p38 MAPK ratio, phospho-90 kDa ribosomal S6 kinase (p-p90RSK) expression, phospho-Bad (p-Bad) expression, the phospho-cAMP response element-binding protein (p-CREB)/CREB ratio, the cytosolic and mitochondrial Bcl-2/Bax ratios, and the cytosolic Bcl-xL/Bax ratio in the cortical penumbra 7 d after reperfusion. SB203580, a specific inhibitor of p38 MAPK, administered 30 min prior to ischemia abrogated the downregulating effects of I-FA on cerebral infarction, and mitochondrial Bax and cleaved caspase-3 expression, and the upregulating effects of I-FA on the p-p38 MAPK/p38 MAPK ratio, p-p90RSK expression, p-Bad expression, and the p-CREB/CREB, and cytosolic and mitochondrial Bcl-2/Bax ratios. Our study results thus indicate that P-FA, I-FA, and R-FA effectively suppress reactive astrocytosis and exert neuroprotective effects against cerebral infarction by activating p38 MAPK signaling. The regulating effects of P-FA, I-FA, and R-FA on Bax-induced apoptosis result from activation of the p38 MAPK/p90RSK/CREB/Bcl-2 signaling pathway, and eventually contribute to inhibition of the cytochrome c-mediated caspase-3-dependent apoptotic pathway in the cortical penumbra 7 d after reperfusion.

Ferulic Acid Administered at Various Time Points Protects against Cerebral Infarction by Activating p38 MAPK/p90RSK/CREB/Bcl-2 Anti-Apoptotic Signaling in the Subacute Phase of Cerebral Ischemia-Reperfusion Injury in Rats

PubMed Central

Cheng, Chin-Yi; Tang, Nou-Ying; Kao, Shung-Te; Hsieh, Ching-Liang

2016-01-01

Objectives This study aimed to evaluate the effects of ferulic acid (FA) administered at various time points before or after 30 min of middle cerebral artery occlusion (MCAo) followed by 7 d of reperfusion and to examine the involvement of mitogen-activated protein kinase (MAPK) signaling pathways in the cortical penumbra. Methods FA was intravenously administered to rats at a dose of 100 mg/kg 24 h before ischemia (B-FA), 2 h before ischemia (P-FA), immediately after ischemic insult (I-FA), 2 h after reperfusion (R-FA), or 24 h after reperfusion (D-FA). Results Our study results indicated that P-FA, I-FA, and R-FA effectively reduced cerebral infarct areas and neurological deficits. P-FA, I-FA, and R-FA significantly downregulated glial fibrillary acidic protein (GFAP), mitochondrial Bax, cytochrome c, and cleaved caspase-3 expression, and effectively restored the phospho-p38 MAPK (p-p38 MAPK)/p38 MAPK ratio, phospho-90 kDa ribosomal S6 kinase (p-p90RSK) expression, phospho-Bad (p-Bad) expression, the phospho-cAMP response element-binding protein (p-CREB)/CREB ratio, the cytosolic and mitochondrial Bcl-2/Bax ratios, and the cytosolic Bcl-xL/Bax ratio in the cortical penumbra 7 d after reperfusion. SB203580, a specific inhibitor of p38 MAPK, administered 30 min prior to ischemia abrogated the downregulating effects of I-FA on cerebral infarction, and mitochondrial Bax and cleaved caspase-3 expression, and the upregulating effects of I-FA on the p-p38 MAPK/p38 MAPK ratio, p-p90RSK expression, p-Bad expression, and the p-CREB/CREB, and cytosolic and mitochondrial Bcl-2/Bax ratios. Conclusions Our study results thus indicate that P-FA, I-FA, and R-FA effectively suppress reactive astrocytosis and exert neuroprotective effects against cerebral infarction by activating p38 MAPK signaling. The regulating effects of P-FA, I-FA, and R-FA on Bax-induced apoptosis result from activation of the p38 MAPK/p90RSK/CREB/Bcl-2 signaling pathway, and eventually contribute to inhibition of the cytochrome c-mediated caspase-3-dependent apoptotic pathway in the cortical penumbra 7 d after reperfusion. PMID:27187745

Effects of high-voltage electrostatic fields on the quality of tilapia meat during refrigeration.

PubMed

Hsieh, Chang-Wei; Lai, Cheng-Hung; Lee, Chia-Hsin; Ko, Wen-Ching

2011-08-01

Fresh fish is typically brought to market refrigerated at approximately 4 °C, R-storage. A storage method has been devised that combines refrigeration with a high-voltage electrostatic field (100 kV/m; E-storage). It was developed to improve the quality and prolong the shelf life of foods. This study investigated changes in the freshness of tilapia meat under E-storage conditions. The total viable count of tilapia reached 10⁷ CFU/g on the 7th d of refrigeration in R-storage. By the 6th d, K-value had increased from 20% to 61.7% for E-storage and to 94.7% for R-storage. Volatile basic nitrogen had increased from 12.54 mg/100 g to about 24.34 and 25.03 mg/100 g for R- and E-storage (on the 7th and 10th d), respectively. The sensory assessment also indicated that E-storage yielded an improvement in quality over that of R-storage. Practical application of the study model has the potential to prolong the freshness of fish. © 2011 Institute of Food Technologists®

The Freon loop double containment design for Spacelab refrigerator/freezer to protect environment

NASA Technical Reports Server (NTRS)

Hye, A.

1985-01-01

General Electric is building a vapor compression refrigerator/freezer for NASA-Johnson Space Center for the Spacelab mission SLS-1 for life sciences experiments. Freon R502 is used as refrigerant. As R502 is considered toxic, the whole Freon loop is enclosed in a second containment to avoid exposure to crewmen. A detailed description of the design and construction of the safety enclosure is presented.

MicroRNA-134-5p promotes high glucose-induced podocyte apoptosis by targeting bcl-2

PubMed Central

Qian, Xiaoxiao; Tan, Juan; Liu, Ling; Chen, Sheng; You, Na; Yong, Huijuan; Pan, Minglin; You, Qiang; Ding, Dafa; Lu, Yibing

2018-01-01

Podocyte apoptosis is a typical early feature of diabetic nephropathy (DN), with loss of nephrin integrity contributing to increased proteinuria in patients with DN. Emerging evidence shows that microRNAs (miRNAs) play vital roles in the pathogenesis of DN. Thus, we aimed to further elucidate the role of miRNAs in podocyte apoptosis in DN. We used db/db and db/m mice maintained under a continuous feeding regime for 12 weeks. Using microarray analysis, we found several miRNAs potentially related to podocyte apoptosis. In addition, we cultured a conditionally immortalized human podocyte cell line in 30 mM D-glucose and found that miR-134-5p was upregulated in both db/db mice and high-glucose (HG)-treated podocytes. Upregulation of miR-134-5p was accompanied by podocyte apoptosis and downregulation of nephrin. Inhibition of miR-134-5p produced the opposite effect. Dual-luciferase reporter assays showed that miR-134-5p directly targeted the 3’-untranslated region of the B-cell lymphoma-2 gene (BCL2), and further study confirmed an increase in bcl-2 protein level in HG-treated podocytes transfected with anti-miR-134-5p. Knockdown of BCL2 impeded the antiapoptotic effect of anti-miR-134-5p. Finally, we found that miR-134-5p might regulate apoptosis in db/db mice and podocytes by targeting BCL2. Taken together, our findings suggest that miR-134-5p promotes podocyte apoptosis under HG conditions by targeting BCL2. Our study provides a meaningful approach to interpret the mechanisms of action of miRNAs involved in DN. PMID:29636888

Comparative study of cryogen spray cooling with R-134a and R-404a: implications for laser treatment of dark human skin

NASA Astrophysics Data System (ADS)

Dai, Tianhong; Yaseen, Mohammad A.; Diagaradjane, Parmeswaran; Chang, David W.; Anvari, Bahman

2006-07-01

Cutaneous laser treatment in dark skin patients is challenging due to significant light absorption by the melanin at the basal layer of epidermis, which can result in irreversible nonspecific thermal injury to the epidermis. Cryogen spray cooling (CSC) with R-134a (boiling point ≈ -26.2°C at 1 atm), which is currently used during cutaneous laser treatment, has shown poor efficacy in protecting dark human skin. We investigated the potential of CSC with R-404a (boiling point ≈ -46.5°C at 1 atm), which has a lower boiling point than R-134a, for improved therapeutic outcome in dark human skin at three levels: in vitro (epoxy resin skin phantom), ex vivo (normal dark human skin sample), and in vivo (skin of the rabbit external ear). The skin phantom was used to acquire the surface and internal temperature profiles in response to CSC with R-134a or R-404a at various spurt durations, based upon which CSC-induced heat removal from the skin phantom was estimated using an algorithm that solved a one-dimensional inverse heat conduction problem. CSC with R-404a increased the temperature reductions within the phantom and subsequently the amount of heat removal from the phantom in comparison to that with R-134a. Normal ex vivo Fitzpatrick types V-VI human skin samples were used to investigate the thermal response of dark human skin epidermis to CSC (R-134a or R-404a) at various spurt durations in conjunction with 595-nm pulsed dye laser irradiation at various radiant exposures. Cryogen R-404a increased the threshold radiant exposures for irreversible thermal injury to the epidermis in dark pigmentation skin. No obvious CSC-induced morphological changes to human skin was observed when sprayed with R404-a spurts using durations up to 300 ms. In vivo rabbit ear vasculature was used as a model of cutaneous anomalies to assess the influences of CSC (with R-134a or R-404a) on the photothermolysis of dermal blood vessels. CSC (R-134a or R-404a) with the spurt durations of 100 to 300 ms increased the most superficial depth of thermally damaged dermal blood vessel compared with the sites without CSC, implying possible nonspecific cooling of superficial dermal blood vessels by the cryogen spurts with the settings applied.

Characteristics of a Refrigeration Cycle Using a Zeotropic Refrigerant Mixture with a Temperature Glide Shift Heat Exchanger

NASA Astrophysics Data System (ADS)

Endoh, Kazuhiro; Matsushima, Hiroaki; Nonaka, Masayuki

HFC zeotropic refrigerant mixture R-407C is one of the promising alternatives for HCFC-22. We have found that the coefficient of performance (COP) of the refrigeration cycle using R-407C is improved by installing a temperature glide shift heat exchanger (TGSX) which takes advantage of zeotropic characteristics to an air-conditioner. We obtained the characteristics of a refrigeration cycle of experimental apparatus with comparison to those of a fundamental refrigeration cycle based on the refrigerant thermodynamic properties. We concluded that the COP improvement ratio of experimental apparatus with the TGSX to that without the TGSX is greater than that ratio which is calculated from the fundamental refrigeration cycle. This proved to be caused by the pressure loss of low pressure side which is not taken into account in the fundamental refrigeration cycle.

Comparative Genomics of Regulation of Fatty Acid and Branched-chain Amino Acid Utilization in Proteobacteria

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kazakov, Alexey E.; Rodionov, Dmitry A.; Arkin, Adam Paul

2008-10-31

Bacteria can use branched-chain amino acids (ILV, i.e. isoleucine, leucine, valine) and fatty acids (FA) as sole carbon and energy sources convering ILV into acetyl-CoA, propanoyl-CoA and propionyl-CoA, respectively. In this work, we used the comparative genomic approach to identify candidate transcriptional factors and DNA motifs that control ILV and FA utilization pathways in proteobacteria. The metabolic regulons were characterized based on the identification and comparison of candidate transcription factor binding sites in groups of phylogenetically related genomes. The reconstructed ILV/FA regulatory network demonstrates considerable variability and involves six transcriptional factors from the MerR, TetR and GntR families binding tomore » eleven distinct DNA motifs. The ILV degradation genes in gamma- and beta-proteobacteria are mainly regulated by anovel regulator from the MerR family (e.g., LiuR in Pseudomonas aeruginosa) (40 species), in addition, the TetR-type regulator LiuQ was identified in some beta-proteobacteria (8 species). Besides the core set of ILV utilization genes, the LiuR regulon in some lineages is expanded to include genes from other metabolic pathways, such as the glyoxylate shunt and glutamate synthase in the Shewanella species. The FA degradation genes are controlled by four regulators including FadR in gamma-proteobacteria (34 species), PsrA in gamma- and beta-proteobacteria (45 species), FadP in beta-proteobacteria (14 species), and LiuR orthologs in alpha-proteobacteria (22 species). The remarkable variability of the regulatory systems associated with the FA degradation pathway is discussed from the functional and evolutionary points of view.« less

HEAT TRANSFER EVALUATION OF HFC-236FA IN CONDENSATION AND EVAPORATION

EPA Science Inventory

The report gives results of an evaluation of the shell-side heat transfer performance of hydrofluorocarbon (HFC)-236fa, which is considered to be a potential substitute for chlorofluorocarbon (CFC)-114 in Navy shipboard chillers, for both conventional finned [1024- and 1575-fpm (...

A novel way to upgrade the coarse part of a high calcium fly ash for reuse into cement systems.

PubMed

Antiohos, S K; Tsimas, S

2007-01-01

Reject fly ash (rFA) represents a significant portion of the fly ashes produced from coal-fired power plants. Due to the high carbon content and large particle mean diameter, rFA is not utilized in the construction sector (for example, as supplementary cementing material) and is currently dumped into landfills, thus representing an additional environmental burden. Recently, the feasibility of using rFA in a relatively small number of applications, like solidification/stabilization of other wastes, has been investigated by different researchers. However, as the overall amount of fly ash utilized in such applications is still limited, there is a need to investigate other possibilities for rFA utilization starting from a deeper understanding of its properties. In the work presented herein, mechanical and hydration properties of cementitious materials prepared by blending the coarse fraction of a lignite high-calcium fly ash with ordinary cement were monitored and compared with the respective ones of a good quality fly ash-cement mixture. The results of this work reveal that a relatively cheap, bilateral classification-grinding method is able to promote the pozzolanic behavior of the rFAs, so that the overall performances of rFA containing cements are drastically improved. The evaluation of these results supports the belief that appropriate utilization of non-standardized materials may lead to new environmental-friendly products of superior quality.

Development of High Efficiency Carbon Dioxide Commercial Heat Pump Water Heater

DOE Office of Scientific and Technical Information (OSTI.GOV)

Michael PETERSEN; Chad D. BOWERS; Stefan ELBEL

Although heat pump water heaters are today widely accepted in both Japan and Europe, where energy costs are high and government incentives for their use exist, acceptance of such products in the US has been limited. While this trend is slowly changing with the introduction of heat pump water heaters into the residential market, but acceptance remains low in the commercial sector. The objective of the presented work is the development of a high efficiency R744 heat pump water heater for commercial applications with effective utilization of the cooling capability for air conditioning and/or refrigeration. The ultimate goal is tomore » achieve total system COP of up to 8. This unit will be targeted at commercial use where some cooling load is typically needed year round, such as restaurants, hotels, nursing homes, and hospitals. This paper presents the performance results from the development of four R744 commercial heat pump water heater packages of approximately 35 kW and comparison to a commercially available baseline R134a unit of the same capacity and footprint. In addition, the influences of an internal heat exchanger and an enhanced evaporator on the system performance are described and recommendations are made for further improvements of the R744 system.« less

Qualification testing of solar photovoltaic powered refrigerator freezers for medical use in remote geographic locations

NASA Astrophysics Data System (ADS)

Kaszeta, W. J.

1982-12-01

One of the primary obstacles to the application of vaccination in developing countries is the lack of refrigerated storage. Vaccines exposed to elevated temperatures suffer a permanent loss of potency. Photovoltaic (PV) powered refrigerator/freezer (R/F) units could surmount the problem of refrigeration in remote areas where no reliable commercial power supply is available. The performance measurements of two different models of PV powered R/F units for medical use are presented. Qualification testing consisted of four major procedures: no-load pull down, ice making, steady-state (maintenance), and holdover. Both R/F units met the major World Health Organization (WHO) requirements. However, the testing performed does not provide complete characterization of the two units; such information could be derived only from further extensive test procedures.

Qualification testing of solar photovoltaic powered refrigerator freezers for medical use in remote geographic locations

NASA Technical Reports Server (NTRS)

Kaszeta, W. J.

1982-01-01

One of the primary obstacles to the application of vaccination in developing countries is the lack of refrigerated storage. Vaccines exposed to elevated temperatures suffer a permanent loss of potency. Photovoltaic (PV) powered refrigerator/freezer (R/F) units could surmount the problem of refrigeration in remote areas where no reliable commercial power supply is available. The performance measurements of two different models of PV powered R/F units for medical use are presented. Qualification testing consisted of four major procedures: no-load pull down, ice making, steady-state (maintenance), and holdover. Both R/F units met the major World Health Organization (WHO) requirements. However, the testing performed does not provide complete characterization of the two units; such information could be derived only from further extensive test procedures.

Man o' War Mutation in UDP-α-D-Xylose Synthase Favors the Abortive Catalytic Cycle and Uncovers a Latent Potential for Hexamer Formation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Walsh, Jr., Richard M.; Polizzi, Samuel J.; Kadirvelraj, Renuka

The man o’ war (mow) phenotype in zebrafish is characterized by severe craniofacial defects due to a missense mutation in UDP-α-D-xylose synthase (UXS), an essential enzyme in proteoglycan biosynthesis. The mow mutation is located in the UXS dimer interface ~16 Å away from the active site, suggesting an indirect effect on the enzyme mechanism. We have examined the structural and catalytic consequences of the mow mutation (R236H) in the soluble fragment of human UXS (hUXS), which shares 93% sequence identity with the zebrafish enzyme. In solution, hUXS dimers undergo a concentration-dependent association to form a tetramer. Sedimentation velocity studies showmore » that the R236H substitution induces the formation of a new hexameric species. Using two new crystal structures of the hexamer, we show that R236H and R236A substitutions cause a local unfolding of the active site that allows for a rotation of the dimer interface necessary to form the hexamer. The disordered active sites in the R236H and R236A mutant constructs displace Y231, the essential acid/base catalyst in the UXS reaction mechanism. The loss of Y231 favors an abortive catalytic cycle in which the reaction intermediate, UDP-α-D-4-keto-xylose, is not reduced to the final product, UDP-α-D-xylose. Surprisingly, the mow-induced hexamer is almost identical to the hexamers formed by the deeply divergent UXS homologues from Staphylococcus aureus and Helicobacter pylori (21% and 16% sequence identity, respectively). The persistence of a latent hexamer-building interface in the human enzyme suggests that the ancestral UXS may have been a hexamer.« less

Role of diffusion tensor imaging or magnetic resonance spectroscopy in the diagnosis and disability assessment of amyotrophic lateral sclerosis.

PubMed

Liu, Chanchan; Jiang, Rifeng; Yi, Xiyan; Zhu, Wenzhen; Bu, Bitao

2015-01-15

To compare the results of magnetic resonance spectroscopy (MRS) and diffusion tensor imaging (DTI) in amyotrophic lateral sclerosis (ALS) patients. Nineteen ALS patients and thirteen age-matched healthy controls underwent MRS and DTI between October 2013 and July 2014. Fractional anisotropy (FA), apparent diffusion coefficient (ADC), N-acetylaspartate (NAA), choline (Cho), and creatine (Cr) were collected as the quantitative results of the imaging study. The ALS functional rating scale-revised (ALSFRS-R) and disease progression rate were evaluated to assess patients' disability. The imaging study results were compared between ALS patients and healthy controls. The relationship between disability assessment and imaging study results was analyzed. NAA/Cr in the motor cortex and FA in the corticospinal tract (CST) of both sides were significantly lower in patients than controls. There was no significant difference between the two groups in Cho/Cr, tract length, tract volume, ADC or NAA. No relationship was found between ALSFRS-R and FA (r=0.243, p=0.316) in the right CST; NAA (r=0.095, p=0.699) or NAA/Cr (r=0.172, p=0.481) in the left motor cortex; or NAA (r=0.320, p=0.182) or NAA/Cr (r=0.193, p=0.492) in the right motor cortex. There was no relationship between the disease progression rate and FA, NAA, or NAA/Cr on either side. NAA/Cr and FA can help diagnose ALS. Regional brain NAA/Cr and FA values could not assess the ALSFRS-R or disease progression rate. Copyright © 2014 Elsevier B.V. All rights reserved.

Outcome assessment of hemiparesis due to intracerebral hemorrhage using diffusion tensor fractional anisotropy.

PubMed

Koyama, Tetsuo; Marumoto, Kohei; Uchiyama, Yuki; Miyake, Hiroji; Domen, Kazuhisa

2015-04-01

This study aimed to evaluate the prognostic efficacy of magnetic resonance diffusion tensor fractional anisotropy (FA) for patients with hemiparesis due to intracerebral hemorrhage. Diffusion tensor FA brain images were acquired 14-21 days after putaminal and/or thalamic hemorrhage. The ratio of FA values within the cerebral peduncles of the affected and unaffected hemispheres (rFA) was calculated for each patient (n = 40) and assessed for correlation with Brunnstrom stage (BRS, 1-6), motor component of the functional independence measure (FIM-motor, 13-91), and the total length of stay (LOS) until discharge from rehabilitation (P < .05). Ordinal logistic regression analyses were conducted to determine the relationships between rFA and specific outcomes as measured by BRS range (poor, BRS 1 or 2; moderate, BRS 3 or 4; and good, BRS 5 or 6; P < .05). The rFA values were .571-1.043 (median, .856) and BRS scores were 1-6 (median, 4) for shoulder/elbow/forearm, 1-6 (median, 4) for hand, and 2-6 (median, 4) for lower extremities. FIM-motor scores were 58-86 (median, 78) and LOS ranged from 42 to 225 days (median, 175.5 days). Correlation coefficients were statistically significant between rFA and shoulder/elbow/forearm BRS (.696), hand BRS (.779), lower extremity BRS (.631), FIM-motor (.442), and LOS (-.598). Logistic model fit was moderate for shoulder/elbow/forearm BRS (R(2) = .221) and lower extremity BRS (R(2) = .277), but was much higher for hand BRS (R(2) = .441). Diffusion tensor FA values are predictive of clinical outcome from hemiparesis due to putaminal and/or thalamic hemorrhage, particularly hand function recovery. Copyright © 2015 National Stroke Association. Published by Elsevier Inc. All rights reserved.

FLAME SUPPRESSION AND LUBRICANT INTERACTION OF HYDROCARBON MIXTURES FOR HOUSEHOLD REFRIGERATOR/FREEZERS

EPA Science Inventory

The paper discusses the flame suppression and lubricant interaction of hydrocarbon (HC) mixtures for household refrigerator/freezers (R/Fs). The work focuses on blending the minimum amount of a fluoroiodocarbon (FIC) with previously optimized R/F-tested HC mixtures to reduce thei...

TESTING OF REFRIGERANT MIXTURES IN RESIDENTIAL HEAT PUMPS

EPA Science Inventory

The report gives results of an investigation of four possibilities for replacing Hydrochlorofluorocarbon-22 (HCFC-22) with the non-ozone-depleting new refrigerants R-407D and R-407C in residential heat pumps. The first and simplest scenario was a retrofit with no hardware modific...

Preparation and Characterization of High-Purity Metal Fluorides for Photonic Applications

DTIC Science & Technology

2011-01-01

I . Epstein and M. Sheik- Bahae , “Optical Refrigeration in Solids: Fun- damentals and Overview”; pp. 1–32 in Optical Refrigeration. Science and...Applications of Laser Cooling of Solids, Edited by R. I . Epstein and M. Sheik- Bahae . Wiley, Weinheim, 2009. 12W. G. Rellergert, D. DeMille, R. R. Greco, M. P...Green and Blue Emitting Upconversion Phosphors,” Chem. Mater., 16, 1244–51 (2004). 39W. M. Patterson, D. V. Seletskiy, M. Sheik- Bahae , R. I . Epstein

Interaction of unsaturated fat or coconut oil with monensin in lactating dairy cows fed 12 times daily. II. Fatty acid flow to the omasum and milk fatty acid profile.

PubMed

Reveneau, C; Ribeiro, C V D M; Eastridge, M L; Firkins, J L

2012-04-01

Feeding animal-vegetable (AV) fat or medium-chain fatty acids (FA) to dairy cows can decrease ruminal protozoal counts. However, combining moderate to large amounts of AV fat with monensin (tradename: Rumensin, R) could increase the risk for milk fat depression (MFD), whereas it is not known if diets supplemented with coconut oil (CNO; rich in medium-chain FA) with R would cause MFD. In a 6 × 6 Latin square design with a 2 × 3 factorial arrangement of treatments, 6 rumen-cannulated cows were fed diets without or with R (12 g/909 kg) and either control (no fat), 5% AV fat, or 5% CNO. Diets were balanced to have 21.5% forage neutral detergent fiber, 16.8% crude protein, and 42% nonfiber carbohydrates. Omasal flows of FA were characterized by an increased percentage of trans 18:1 for AV fat and CNO diets compared with the control, a higher percentage of 12:0 and 14:0 for CNO, and higher cis 18:1 for AV fat. Milk FA composition reflected the changes observed for omasal FA digesta flow. The de novo FA synthesis in the mammary gland was decreased by the main effects of R compared without R (averaged over fat treatments) and for added fat (AV fat and CNO) versus control (averaged over R). The percentages of 6:0, 8:0, and 10:0 in milk fat were lower for R and for AV fat and CNO compared with the control. The percentage of trans 18:1 FA in milk fat also higher for AV fat and CNO compared with the control. Against our hypotheses, the feeding of CNO did not prevent MFD, and few interactions between R and fat source were detected. The feeding of CNO did compromise ruminal biohydrogenation, with accumulation of trans 18:1 in the rumen and in milk fat. Copyright © 2012 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Fatty Acid Proportions in Plasma Cholesterol Esters and Phospholipids Are Positively Correlated in Various Swedish Populations.

PubMed

Marklund, Matti; Pingel, Ronnie; Rosqvist, Fredrik; Lindroos, Anna Karin; Eriksson, Jan W; Vessby, Bengt; Oscarsson, Jan; Lind, Lars; Risérus, Ulf

2017-11-01

Background: Fatty acid (FA) proportions in cholesterol esters (CEs) and plasma phospholipids are widely used as dietary biomarkers. Information on how proportions in these fractions correlate could have implications for interpretation and use of FA biomarkers in observational and interventional studies. Objective: We investigated correlations between FA proportions in CEs and phospholipids in free-living individuals and assessed how diet-induced alterations of FA proportions correlate between fractions. Methods: Spearman's rank correlation coefficients ( r s ) between FA proportions (percentage of total FAs) in circulating CEs and phospholipids were calculated separately in 8 individual study populations including Swedish females and males ( N = 2052; age range: 11-84 y), and pooled by inverse-variance weighted meta-analysis. In addition, study populations were stratified by age, sex, body mass index (BMI; in kg/m 2 ), and diabetes status, and strata-specific r s were pooled by meta-analysis. In 2 randomized trials ( N = 79) in which dietary saturated FAs were isocalorically replaced with unsaturated FAs, treatment-wise calculations of r s were conducted between FA changes in CEs and phospholipids. Results: Overall, FA proportions in CEs and phospholipids correlated well and especially strongly for polyunsaturated FAs (PUFAs), with pooled r s (95% CIs) ranging from 0.74 (0.72, 0.76) for α-linolenic acid to 0.92 (0.91, 0.93) for eicosapentaenoic acid. Weak correlations (pooled r s < 0.4) were observed only for palmitic acid and stearic acid, with pooled r s (95% CIs): 0.29 (0.24, 0.33) and 0.30 (0.25, 0.34), respectively. Overall, correlations were not affected by age, sex, BMI, or diabetes status. Strong correlations ( r s ≥ 0.6) between diet-induced FA changes in CEs and phospholipids were observed for most PUFAs. Conclusions: Proportions of most FAs in CEs and phospholipids ranked individuals similarly, suggesting that FA proportions in these fractions can be used interchangeably in populations of diverse age, sex, body composition, and diabetes status. Caution is advised, however, when comparing results from studies assessing palmitic acid or stearic acid in different lipid fractions. © 2017 American Society for Nutrition.

Munitions Classification Library Update and Expansion Data Collection Report: Camp Lejeune and Eglin

DTIC Science & Technology

2015-10-09

Motor 4.5-in T160ES HE R N N N N W without Motor Rocket Motor R N N N N W 66mm M72A1 R Y Y N N U with Coupler and Motor ...66mm M74 R N Y N N W with Motor 3.5-in M30A1 R Y Y N N W WP Smoke with M405 Dummy Fuze and Motor Rocket Motor R Y N N N W 3.5-in M30A1 R N Y N N...N U/P with Motor without Fins 2.36-in M6 R Y Y N N U/P with Motor with Fins Rocket Motor R Y Y N N U/P 2.36-in M6 R N N N N U/P Rifle

Wind tunnel pressurization and recovery system

NASA Technical Reports Server (NTRS)

Pejack, Edwin R.; Meick, Joseph; Ahmad, Adnan; Lateh, Nordin; Sadeq, Omar

1988-01-01

The high density, low toxicity characteristics of refrigerant-12 (dichlorofluoromethane) make it an ideal gas for wind tunnel testing. Present limitations on R-12 emissions, set to slow the rate of ozone deterioration, pose a difficult problem in recovery and handling of large quantities of R-12. This preliminary design is a possible solution to the problem of R-12 handling in wind tunnel testing. The design incorporates cold temperature condensation with secondary purification of the R-12/air mixture by adsorption. Also discussed is the use of Freon-22 as a suitable refrigerant for the 12 foot wind tunnel.

Comparative analysis of various CO 2 configurations in supermarket refrigeration systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sharma, Vishaldeep; Fricke, Brian; Bansal, Pradeep

Our paper presents an analysis of various CO 2 transcritical and cascade/secondary loop refrigeration systems that are becoming popular in supermarket applications with the objective of optimizing the operating parameters of these systems. In addition, the performance of selected CO 2-based refrigeration systems is compared to the baseline R404A multiplex direct expansion system using bin analyses in the eight climate zones of the United States. Moreover, for the refrigeration systems investigated, it was found that the Transcritical Booster System with Bypass Compressor (TBS-BC) had the lowest energy consumption for ambient temperatures (T amb) less than 8 °C, and for highermore » ambient temperatures the R404A direct expansion system was found to have the lowest energy consumption. Finally, the TBS-BC performs equivalent to or better than the R404A direct expansion system in the northern two-thirds of the US. For the southern portion of the US, the R404A multiplex DX system performs better than CO 2 systems.« less

Comparative analysis of various CO 2 configurations in supermarket refrigeration systems

DOE PAGES

Sharma, Vishaldeep; Fricke, Brian; Bansal, Pradeep

2014-07-09

Our paper presents an analysis of various CO 2 transcritical and cascade/secondary loop refrigeration systems that are becoming popular in supermarket applications with the objective of optimizing the operating parameters of these systems. In addition, the performance of selected CO 2-based refrigeration systems is compared to the baseline R404A multiplex direct expansion system using bin analyses in the eight climate zones of the United States. Moreover, for the refrigeration systems investigated, it was found that the Transcritical Booster System with Bypass Compressor (TBS-BC) had the lowest energy consumption for ambient temperatures (T amb) less than 8 °C, and for highermore » ambient temperatures the R404A direct expansion system was found to have the lowest energy consumption. Finally, the TBS-BC performs equivalent to or better than the R404A direct expansion system in the northern two-thirds of the US. For the southern portion of the US, the R404A multiplex DX system performs better than CO 2 systems.« less

5. METAL SHOP ROOM (AREA 108 ON PLAN CA236R36). Looking ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

5. METAL SHOP ROOM (AREA 108 ON PLAN CA-236-R-36). Looking northeast. - Edwards Air Force Base, Air Force Rocket Propulsion Laboratory, Test Stand 1-A Terminal Room, Test Area 1-120, north end of Jupiter Boulevard, Boron, Kern County, CA

Technology Application of Environmental Friendly Refrigeration (Green Refrigeration) on Cold Storage for Fishery Industry

NASA Astrophysics Data System (ADS)

Rasta, IM; Susila, IDM; Subagia, IWA

2018-01-01

The application of refrigeration technology to postharvest fishery products is an very important. Moreover, Indonesia is a tropical region with relatively high temperatures. Fish storage age can be prolonged with a decrease in temperature. Frozen fish can even be stored for several months. Fish freezing means preparing fish for storage in low-temperature cold storage. The working fluid used in cold storage to cool low-temperature chambers and throw heat into high-temperature environments is refrigerant. So far refrigerant used in cold storage is Hydrochloroflourocarbons (HCFC) that is R-22. Chlor is a gas that causes ODP (Ozone Depleting Potential), while Flour is a gas that causes GWP (Global Warming Potential). Government policy began in 2015 to implement Hydrochloroflourocarbons Phase-Out Management Plan. Hydrocarbon (HC) is an alternative substitute for R-22. HC-22 (propane ≥ 99.5%) has several advantages, among others: environmentally friendly, indicated by a zero ODP value, and GWP = 3 (negligible), thermophysical property and good heat transfer characteristics, vapor phase density Which is low, and good solubility with mineral lubricants. The use of HC-22 in cold storage is less than R-22. From the analysis results obtained, cold storage system using HC-22 has better performance and energy consumption is more efficient than the R-22.

Circulating microRNAs correlated with the level of coronary artery calcification in symptomatic patients

PubMed Central

Liu, Wei; Ling, Shukuan; Sun, Weijia; Liu, Tong; Li, Yuheng; Zhong, Guohui; Zhao, Dingsheng; Zhang, Pengfei; Song, Jinping; Jin, Xiaoyan; Xu, Zi; Song, Hailin; Li, Qi; Liu, Shujuan; Chai, Meng; Dai, Qinyi; He, Yi; Fan, Zhanming; Zhou, Yu Jie; Li, Yingxian

2015-01-01

The purpose of this study was to find the circulating microRNAs (miRNAs) co-related with the severity of coronary artery calcification (CAC), and testify whether the selected miRNAs could reflect the obstructive coronary artery disease in symptomatic patients. Patients with chest pain and moderated risk for coronary artery disease (CAD) were characterized with coronary artery calcium score (CACS) from cardiac computed tomography (CT). We analyzed plasma miRNA levels of clinical matched 11 CAC (CACS > 100) and 6 non-CAC (CACS = 0) subjects by microarray profile. Microarray analysis identified 34 differentially expressed miRNAs between CAC and non CAC groups. Eight miRNAs (miR-223, miR-3135b, miR-133a-3p, miR-2861, miR-134, miR-191-3p, miR-3679-5p, miR-1229 in CAC patients) were significantly increased in CAC plasma in an independent clinical matched cohort. Four miRNAs (miR-2861, 134, 1229 and 3135b) were correlated with the degree of CAC. Validation test in angiographic cohort showed that miR-134, miR-3135b and miR-2861 were significantly changed in patients with obstructive CAD . We identified three significantly upregulated circulating miRNAs (miR-134, miR-3135b and 2861) correlated with CAC while detected obstructive coronary disease in symptomatic patients. PMID:26537670

Speed of sound and ideal-gas heat capacity of freon R-236ea

NASA Astrophysics Data System (ADS)

Komarov, S. G.; Gruzdev, V. A.; Stankus, S. V.

2008-09-01

Speed of sound in the gaseous freon R-236ea with the purity of 99.68 mol. % has been measured by the method of ultrasonic interferometer in the range from 263 to 423 K and at pressures from 17 kPA to 4.2 MPa. Errors of temperature, pressure, and speed of sound measurement were estimated to be within +/- 20 mK, ± 1.5 kPa, and ±(0.1+0.2) % respectively. Temperature dependence of ideal-gas heat capacity of R-236ea has been calculated on the basis of the obtained data.

Effect of Oils on Kinematic Viscosity of R134a

NASA Astrophysics Data System (ADS)

Sato, Tomoaki; Takaishi, Yoshinori; Oguchi, Kosei

The kinematic viscosity defined as a ratio of viscosity to density is one of the key properties in producing technically important dimensionless numbers such as Prandtl and Reynolds numbers. We measured both viscosity and density of R134a/POE and R134a/PAG mixtures at saturation in the range of relatively low oilconcentrations. The density measurements for oil-concentrations up to 50 mass% were conducted with a densimeter making use of glass buoys within overall uncertainty of ±1.0%, and the viscosity measurements for oil-concentrations up to 16 mass% were carried out with an oscillating-cup viscometer making use of polarizer with overall uncertainty less than ±3.5%. The kinematic viscosities obtained from the experimental viscosity and density data are presented for both R134a/POE and R134a/PAG mixtures in the range of temperatures from 278 K to 288 K for oil-concentrations up to 15 mass%. The oil-concentration dependence of the kinematic viscosity for both mixtures is also reported.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shen, Bo; Abdelaziz, Omar

R410A has no ozone depletion potential (ODP), and is the most commonly used refrigerant in vapor compression systems for space cooling and heating applications. However, it has significant global warming potential with GWP higher than 1900. To mitigate the global warming effect, industry and research institutes are actively pursuing a replacement for R-410A with the following attributes, much lower GWP along with similar or higher efficiency and capacity. DR-55 (aka R452B) is a design-compatible refrigerant replacement for R-410A. It decreases the GWP by 70%, and has lower working pressure, comparable discharge temperature, and uses the same lubricant, tubing, and valves.more » In this study, we experimentally evaluated the performance of DR-55 as a drop-in replacement for R-410A in a high efficiency rooftop air conditioning unit. The experimental results demonstrated that DR-55 led to 5% higher efficiency at the working conditions of Integrated Energy Efficiency Rating (IEER). DR-55 also showed significantly better high ambient performance from 95 F to 125 F. In addition to the experimental study, we used the DOE/ORNL Heat Pump Design Model to model the RTU using R-410A and DR-55, respectively. The model results were compared to the laboratory measurements. The model validation demonstrates that the refrigerant heat transfer and pressure drop correlations, developed for conventional refrigerants like R-410A, are usable for DR-55. Also, a converted compressor model for DR-55, i.e. reducing volumetric and isentropic efficiencies as a function of the suction and discharge pressures from an R-410A compressor map can predict the compressor mass flow rate and power accurately.« less

Model of Laser-Induced Temperature Changes in Solid-State Optical Refrigerators

DTIC Science & Technology

2010-01-01

Model of laser-induced temperature changes in solid-state optical refrigerators W. M. Patterson,1,a M. Sheik- Bahae ,1 R. I . Epstein,2 and M. P...Applications of Laser Cooling of Sol- ids, edited by R. I . Epstein and M. Sheik- Bahae Wiley, Weinheim, 2009. 2W. Koechner, Solid-State Laser...2004. 19D. V. Seletskiy, S. D. Melgaard, S. Bigotta, A. Di Lieto, M. Tonelli, R. I . Epstein, and M. Sheik- Bahae , in Conference on Lasers and Electro

Omega-3 fatty acids improve appetite in cancer anorexia, but tumor resecting restores it.

PubMed

Goncalves, Carolina G; Ramos, Eduardo J B; Romanova, Irina V; Suzuki, Susumu; Chen, Chung; Meguid, Michael M

2006-02-01

Tumor growth leads to cancer anorexia that is ameliorated using omega-3 fatty acids (omega-3FA). We hypothesize that omega-3FA modulates up-regulation of hypothalamic orexigenic neuropeptide Y (NPY) and down-regulation of anorexigenic alpha melanocyte-stimulating hormone (alpha-MSH) and serotonin 1B receptors (5-HT(1B)-receptors) in tumor-bearing rats. Twenty-eight tumor-bearing rats were fed either chow (TB-Control) or omega-3FA (TB-omega-3FA). When anorexia developed in TB-Control rats, they and a cohort of TB-omega-pi-3 rats were killed. The rest had their tumor resected (R-Control and R-omega-3FA), and when anorexic TB-Controls normalized their food intake, brains were removed for hypothalamic immunocytochemical study of NPY, alpha-MSH, and 5-HT(1B)-receptor antibodies concentrations. Comparison among slides were assessed by image analysis and analyzed by ANOVA and t test. At anorexia, hypothalamic NPY in arcuate nucleus (ARC) increased by 38% in TB-omega3FA versus TB-Control, whereas alpha-MSH decreased 64% in ARC and 29% in paraventricular nucleus (PVN). Omega-3FA diet in anorexia (TB-omega-3FA vs R-omega-3FA) produced similar qualitative changes of NPY (22% increase) and alpha-MSH (31% decrease) in ARC, with concomitant decrease of 37% in 5-HT(1B)-receptors in PVN, confirming the influence of omega-3FA on the hypothalamic food intake modulators. However, after tumor resection (TB-Control vs R-Control) a 97% increase in NPY and a 62% decrease in alpha-MSH occurred that was significantly greater than in rats fed omega-3FA diet. Tumor resection and omega-3FA modifies hypothalamic food intake activity, up-regulating NPY and down-regulating alpha-MSH and 5-HT(1B)-receptors. Tumor resection in anorexic rats on chow diet restored hypothalamic NPY, alpha-MSH, and food intake quantitatively more than in rats fed omega3FA diet.

An Evaluation of the Environmental Impact of Different Commercial Supermarket Refrigeration Systems Using Low Global Warming Potential Refrigerants

DOE Office of Scientific and Technical Information (OSTI.GOV)

Beshr, Mohamed; Aute, Vikrant; Abdelaziz, Omar

Commercial refrigeration systems consumed 1.21 Quads of primary energy in 2010 and are known to be a major source for refrigerant charge leakage into the environment. Thus, it is important to study the environmental impact of commercial supermarket refrigeration systems and improve their design to minimize any adverse impacts. The system s Life Cycle Climate Performance (LCCP) was presented as a comprehensive metric with the aim of calculating the equivalent mass of carbon dioxide released into the atmosphere throughout its lifetime, from construction to operation and destruction. In this paper, an open source tool for the evaluation of the LCCPmore » of different air-conditioning and refrigeration systems is presented and used to compare the environmental impact of a typical multiplex direct expansion (DX) supermarket refrigeration systems based on three different refrigerants as follows: two hydrofluorocarbon (HFC) refrigerants (R-404A, and R-407F), and a low global warming potential (GWP) refrigerant (N-40). The comparison is performed in 8 US cities representing different climates. The hourly energy consumption of the refrigeration system, required for the calculation of the indirect emissions, is calculated using a widely used building energy modeling tool (EnergyPlus). A sensitivity analysis is performed to determine the impact of system charge and power plant emission factor on the LCCP results. Finally, we performed an uncertainty analysis to determine the uncertainty in total emissions for both R-404A and N-40 operated systems. We found that using low GWP refrigerants causes a considerable drop in the impact of uncertainty in the inputs related to direct emissions on the uncertainty of the total emissions of the system.« less

ADVANCED INSULATIONS FOR REFRIGERATOR/FREEZERS: THE POTENTIAL FOR NEW SHELL DESIGNS INCORPORATING POLYMER BARRIER CONSTRUCTION

EPA Science Inventory

The report examines domestic refrigerator/freezer (R/F) design alternatives which may offer greater increase in thermal performance than is possible with panel/foam composites. (NOTE: Current efforts to design and build R/Fs with high performance insulation technology are directe...

78 FR 40128 - Notice of Intent to Prepare a Draft Environmental Impact Statement (EIS) for the Reaches 8, 9...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-07-03

... to R-134+135. The Town proposes to place approximately 74,300 cubic yards of beach quality sand in... beach quality sand is proposed to be placed between R-134+135 and R-135+551 to elevate the existing berm... and dune restoration projects between R-128+955 and R-138+551 with sand placement and the construction...

Fatty acid metabolism in the liver, measured by positron emission tomography, is increased in obese individuals.

PubMed

Iozzo, Patricia; Bucci, Marco; Roivainen, Anne; Någren, Kjell; Järvisalo, Mikko J; Kiss, Jan; Guiducci, Letizia; Fielding, Barbara; Naum, Alexandru G; Borra, Ronald; Virtanen, Kirsi; Savunen, Timo; Salvadori, Piero A; Ferrannini, Ele; Knuuti, Juhani; Nuutila, Pirjo

2010-09-01

Hepatic lipotoxicity results from and contributes to obesity-related disorders. It is a challenge to study human metabolism of fatty acids (FAs) in the liver. We combined (11)C-palmitate imaging by positron emission tomography (PET) with compartmental modeling to determine rates of hepatic FA uptake, oxidation, and storage, as well as triglyceride release in pigs and human beings. Anesthetized pigs underwent (11)C-palmitate PET imaging during fasting (n = 3) or euglycemic hyperinsulinemia (n = 3). Metabolic products of FAs were measured in arterial, portal, and hepatic venous blood. The imaging methodology then was tested in 15 human subjects (8 obese subjects); plasma (11)C-palmitate kinetic analyses were used to quantify systemic and visceral lipolysis. In pigs, PET-derived and corresponding measured FA fluxes (FA uptake, esterification, and triglyceride FA release) did not differ and were correlated with each other. In human beings, obese subjects had increased hepatic FA oxidation compared with controls (mean +/- standard error of the mean, 0.16 +/- 0.01 vs 0.08 +/- 0.01 micromol/min/mL; P = .0007); FA uptake and esterification rates did not differ between obese subjects and controls. Liver FA oxidation correlated with plasma insulin levels (r = 0.61, P = .016), adipose tissue (r = 0.58, P = .024), and systemic insulin resistance (r = 0.62, P = .015). Hepatic FA esterification correlated with the systemic release of FA into plasma (r = 0.71, P = .003). PET imaging can be used to measure FA metabolism in the liver. By using this technology, we found that obese individuals have increased hepatic oxidation of FA, in the context of adipose tissue insulin resistance, and increased FA flux from visceral fat. FA flux from visceral fat is proportional with the mass of the corresponding depot. Copyright © 2010 AGA Institute. Published by Elsevier Inc. All rights reserved.

Can body mass index predict percent body fat and changes in percent body fat with weight loss in bariatric surgery patients?

PubMed

Carey, Daniel G; Raymond, Robert L

2008-07-01

The primary objective of this study was to assess the validity of body mass index (BMI) in predicting percent body fat and changes in percent body fat with weight loss in bariatric surgery patients. Twenty-two bariatric patients (17 female, five male) began the study designed to include 12 months of testing, including data collection within 1 week presurgery and 1 month, 3 months, 6 months, and 1 year postsurgery. Five female subjects were lost to the study between 6 months and 12 months postsurgery, resulting in 17 subjects (12 female, five male) completing the 12 months of testing. Variables measured in the study included height, weight, percent fat (% fat) by hydrostatic weighing, lean mass, fat mass, and basal metabolic rate. Regression analyses predicting % fat from BMI yielded the following results: presurgery r = 0.173, p = 0.479, standard error of estimate (SEE) = 3.86; 1 month r = 0.468, p = 0.043, SEE = 4.70; 3 months r = 0.553, p = 0.014, SEE = 6.2; 6 months r = 0.611, p = 0.005, SEE = 5.88; 12 months r = 0.596, p = 0.007, SEE = 7.13. Regression analyses predicting change in % fat from change in BMI produced the following results: presurgery to 1 month r = -0.134, p = 0.583, SEE = 2.44%; 1-3 months r = 0.265, p = 0.272, SEE = 2.36%; 3-6 months r = 0.206, p = 0.398, SEE = 3.75%; 6-12 months r = 0.784, p = 0.000, SEE = 3.20. Although some analyses resulted in significant correlation coefficients (p < 0.05), the relatively large SEE values would preclude the use of BMI in predicting % fat or change in % fat with weight loss in bariatric surgery patients.

CFD comparison with centrifugal compressor measurements on a wide operating range

NASA Astrophysics Data System (ADS)

Le Sausse, P.; Fabrie, P.; Arnou, D.; Clunet, F.

2013-04-01

Centrifugal compressors are widely used in industrial applications thanks to their high efficiency. They are able to provide a wide operating range before reaching the flow barrier or surge limits. Performances and range are described by compressor maps obtained experimentally. After a description of performance test rig, this article compares measured centrifugal compressor performances with computational fluid dynamics results. These computations are performed at steady conditions with R134a refrigerant as fluid. Navier-Stokes equations, coupled with k-ɛ turbulence model, are solved by the commercial software ANSYS-CFX by means of volume finite method. Input conditions are varied in order to calculate several speed lines. Theoretical isentropic efficiency and theoretical surge line are finally compared to experimental data.

Comparison of HFC-134a and the ternary blend, Suva MP39, as replacements for the refrigerant, CGC-12

NASA Astrophysics Data System (ADS)

Fletcher, Lyn E.

1993-09-01

The refrigerant gas CFC-12 has been widely used in Royal Australian Navy (RAN) equipment. With the Montreal protocol phase-out of this and other ozone depleting substances, alternative refrigerant gases must be identified. These replacements would ideally have the same efficiency as CFC-12, cause no health and safety risks and allow changeover to proceed with minimal costs. This paper reviews the attributes of two refrigerant gases, HFC-134a and Suva MP39, which are being considered by the RAN.

Estrogen Inhibits Dlk1/FA1 Production: A Potential Mechanism for Estrogen Effects on Bone Turnover

PubMed Central

Abdallah, B. M.; Bay-Jensen, A.; Srinivasan, B.; Tabassi, N. C.; Garnero, P.; Delaissé, J.; Khosla, S.; Kassem, M.

2011-01-01

We have recently identified Dlk1/FA1 (Delta-like 1/FA1) as a novel regulator of bone mass that functions to mediate bone loss, under estrogen deficiency, in mice. In this report, we investigated the effects of estrogen (E)-deficiency and E replacement on serum (s) levels of Dlk1/FA1 (s-Dlk1FA1) and its correlation with bone turnover markers. s-Dlk1/FA1 and bone turnover markers (s-CTx and s-osteocalcin), were measured in two cohorts: a group of pre- and postmenopausal women (n=100) and a group of postmenopausal women, where half had received estrogen replacement therapy (ERT) (n=166). s-Dlk1/FA1, and s-CTX were elevated in postmenopausal E-deficient compared to premenopausal E-replete women (both; P<0.001). s-Dlk1/FA1 was correlated with s-CTX (r=0.30, P<0.01). ERT, in postmenopausal women, decreased s-Dlk1/FA1, as well as s-CTX and s-osteoclacin (all; P<0.0001). Changes in s-Dlk1 were significantly correlated with those observed in s-CTx (r=0.18, P<0.05) and s-osteocalcin (r=0.28, P<0.001). In conclusion, s-Dlk1/FA1 is influenced by E-deficiency and is correlated with bone turnover. Increased levels of s-Dlk1/FA1 in post-menopausal women may be a mechanism mediating the effects estrogen deficiency on bone turnover. PMID:21681814

EVALUATION OF OZONE-FRIENDLY HYDROFLUOROPROPANE-BASED ZEOTROPIC REFRIGERANT MIXTURES IN A LORENZ-MEUTZNER REFRIGERATOR/FREEZER

EPA Science Inventory

The two-evaporator (located in the freezer and fresh food compartments) design of the Lorenz-Meutzner (L-M) refrigerator/freezer (R/F) makes it a leading candidate for use of zeotropic refrigerant mixtures. Zeotrophic mixtures can have significant temperature glides during evapor...

Validation of the facial dysfunction domain of the Penn Acoustic Neuroma Quality-of-Life (PANQOL) Scale.

PubMed

Lodder, Wouter L; Adan, Guleed H; Chean, Chung S; Lesser, Tristram H; Leong, Samuel C

2017-06-01

The objective of this study is to evaluate the strength of content validity within the facial dysfunction domain of the Penn Acoustic Neuroma Quality-of-Life (PANQOL) Scale and to compare how it correlates with a facial dysfunction-specific QOL instrument (Facial Clinimetric Evaluation, FaCE). The study design is online questionnaire survey. Members of the British Acoustic Neuroma Association received both PANQOL questionnaires and the FaCE scale. 158 respondents with self-identified facial paralysis or dysfunction had completed PANQOL and FaCE data sets for analysis. The mean composite PANQOL score was 53.5 (range 19.2-93.5), whilst the mean total FaCE score was 50.9 (range 10-95). The total scores of the PANQOL and FaCE correlated moderate (r = 0.48). Strong correlation (r = 0.63) was observed between the PANQOL's facial dysfunction domain and the FaCE total score. Of all the FaCE domains, social function was strongly correlated with the PANQOL facial dysfunction domain (r = 0.66), whilst there was very weak-to-moderate correlation (range 0.01-0.43) to the other FaCE domains. The current study has demonstrated a strong correlation between the facial dysfunction domains of PANQOL with a facial paralysis-specific QOL instrument.

Associations of educational attainment, occupation and community poverty with knee osteoarthritis in the Johnston County (North Carolina) osteoarthritis project.

PubMed

Callahan, Leigh F; Cleveland, Rebecca J; Shreffler, Jack; Schwartz, Todd A; Schoster, Britta; Randolph, Randy; Renner, Jordan B; Jordan, Joanne M

2011-01-01

The purpose of this study was to examine data from the Johnston County Osteoarthritis (OA) Project for independent associations of educational attainment, occupation and community poverty with tibiofemoral knee OA. A cross-sectional analysis was conducted on 3,591 individuals (66% Caucasian and 34% African American). Educational attainment (< 12 years or ≥12 years), occupation (non-managerial or not), and census block group household poverty rate (< 12%, 12 to 25%, > 25%) were examined separately and together in logistic models adjusting for covariates of age, gender, race, body mass index (BMI), smoking, knee injury and occupational activity score. Outcomes were presence of radiographic knee OA (rOA), symptomatic knee OA (sxOA), bilateral rOA and bilateral sxOA. When all three socioeconomic status (SES) variables were analyzed simultaneously, low educational attainment was significantly associated with rOA (odds ratio (OR) = 1.44, 95% confidence interval (CI) 1.20, 1.73), bilateral rOA (OR = 1.43, 95% CI 1.13, 1.81), and sxOA (OR = 1.66, 95% CI 1.34, 2.06), after adjusting for covariates. Independently, living in a community of high household poverty rate was associated with rOA (OR = 1.83, 95% CI 1.43, 2.36), bilateral rOA (OR = 1.56, 95% CI 1.12, 2.16), and sxOA (OR = 1.36, 95% CI 1.00, 1.83). Occupation had no significant independent association beyond educational attainment and community poverty. Both educational attainment and community SES were independently associated with knee OA after adjusting for primary risk factors for knee OA.

Relationship between diffusion tensor fractional anisotropy and long-term motor outcome in patients with hemiparesis after middle cerebral artery infarction.

PubMed

Koyama, Tetsuo; Marumoto, Kohei; Miyake, Hiroji; Domen, Kazuhisa

2014-10-01

Magnetic resonance diffusion tensor fractional anisotropy (DTI-FA) is often used to characterize neural damage after stroke. Here we assessed the relationship between DTI-FA and long-term motor outcome in patients after middle cerebral artery (MCA) infarction. Fractional anisotropy (FA) maps were generated from diffusion tensor brain images obtained from 16 patients 14-18 days postinfarction, and tract-based spatial statistics (TBSS) analysis was applied. Regions of interest were set within the right and left corticospinal tracts, and mean FA values were extracted from individual TBSS data. Hemiparesis motor outcome was evaluated according to Brunnstrom stage (BRS: 1-6, severe-normal) for separate shoulder/elbow/forearm, hand, and lower extremity functions, as well as the motor component score of the Functional Independence Measure (FIM-motor: 13-91, null-full) 5-7 months after onset. Ratios between FA values in the affected and unaffected hemispheres (rFA) were assessed by BRS and FIM-motor scores. rFA values were .636-.984 (median, .883) and BRS scores were 1-6 (median, 3) for shoulder/elbow/forearm, 2-6 (median, 3) for hand, and 3-6 (median, 5) for the lower extremities. FIM-motor scores were 51-90 (median, 75). Analysis revealed significant relationships between rFA and BRS data (correlation coefficient: .687 for shoulder/elbow/forearm, .579 for hand, and .623 for lower extremities) but no significance relationship between rFA and FIM-motor scores. The results suggest that DTI-FA is applicable for predicting the long-term outcome of extremity functions after MCA infarction. Copyright © 2014 National Stroke Association. Published by Elsevier Inc. All rights reserved.

Relationship between diffusion tensor fractional anisotropy and motor outcome in patients with hemiparesis after corona radiata infarct.

PubMed

Koyama, Tetsuo; Marumoto, Kohei; Miyake, Hiroji; Domen, Kazuhisa

2013-11-01

This study examined the relationship between fractional anisotropy (FA) values of magnetic resonance-diffusion tensor imaging (DTI) and motor outcome (1 month after onset) in 15 patients with hemiparesis after ischemic stroke of corona radiata lesions. DTI data were obtained on days 14-18. FA values within the cerebral peduncle were analyzed using a computer-automated method. Motor outcome of hemiparesis was evaluated according to Brunnstrom stage (BRS; 6-point scale: severe to normal) for separate shoulder/elbow/forearm, wrist/hand, and lower extremity functions. The ratio of FA values in the affected hemisphere to those in the unaffected hemisphere (rFA) was assessed in relation to the BRS data (Spearman rank correlation test, P<.05). rFA values ranged from .715 to 1.002 (median=.924). BRS ranged from 1 to 6 (median=4) for shoulder/elbow/forearm, from 1 to 6 (median=5) for wrist/hand, and from 2 to 6 (median=4) for the lower extremities. Analysis revealed statistically significant relationships between rFA and upper extremity functions (correlation coefficient=.679 for shoulder/elbow/forearm and .706 for wrist/hand). Although slightly less evident, the relationship between rFA and lower extremity function was also statistically significant (correlation coefficient=.641). FA values within the cerebral peduncle are moderately associated with the outcome of both upper and lower extremity functions, suggesting that DTI may be applicable for outcome prediction in stroke patients with corona radiata infarct. Copyright © 2013 National Stroke Association. Published by Elsevier Inc. All rights reserved.

Cooling performance and evaluation of automotive refrigeration system for a passenger car

NASA Astrophysics Data System (ADS)

Prajitno, Deendarlianto, Majid, Akmal Irfan; Mardani, Mahardeka Dhias; Wicaksono, Wendi; Kamal, Samsul; Purwanto, Teguh Pudji; Fauzun

2016-06-01

A new design of automotive refrigeration system for a passenger car was proposed. To ensure less energy consumption and optimal thermal comfort, the performance of the system were evaluated. This current research was aimed to evaluate the refrigeration characteristics of the system for several types of cooling load. In this present study, a four-passenger wagon car with 1500 cc gasoline engine that equipped by a belt driven compressor (BDC) was used as the tested vehicle. To represent the tropical condition, a set of lamps and wind sources are installed around the vehicle. The blower capacity inside a car is varied from 0.015 m/s to 0.027 m/s and the compressor speed is varied at variable 820, 1400, and 2100 rpm at a set temperature of 22°C. A set of thermocouples that combined by data logger were used to measure the temperature distribution. The system uses R-134a as the refrigerant. In order to determine the cooling capacity of the vehicle, two conditions were presented: without passengers and full load conditions. As the results, cooling capacity from any possible heating sources and transient characteristics of temperature in both systems for the cabin, engine, compressor, and condenser are presented in this work. As the load increases, the outlet temperature of evaporator also increases due to the increase of condensed air. This phenomenon also causes the increase of compressor work and compression ratio which associated to the addition of specific volume in compressor inlet.

Neuroprotective Role of Exogenous Brain-Derived Neurotrophic Factor in Hypoxia-Hypoglycemia-Induced Hippocampal Neuron Injury via Regulating Trkb/MiR134 Signaling.

PubMed

Huang, Weidong; Meng, Facai; Cao, Jie; Liu, Xiaobin; Zhang, Jie; Li, Min

2017-05-01

Hypoxic-ischemic brain injury is an important cause of neonatal mortality and morbidity. Brain-derived neurotrophic factor (BDNF) has been reported to play a neuroprotective role in hypoxic-ischemic brain injury; however, the specific effects and mechanism of BDNF on hypoxic-hypoglycemic hippocampal neuron injury remains unknown. The current study investigated the action of BDNF in regulating cerebral hypoxic-ischemic injury by simulating hippocampal neuron ischemia and hypoxia. We found that BDNF, p-Trkb, and miR-134 expression levels decreased, and that exogenous BDNF increased survival and reduced apoptosis in hypoxic-hypoglycemic hippocampal neurons. The results also show that BDNF inhibits MiR-134 expression by activating the TrkB pathway. Transfection with TrkB siRNA and pre-miR-134 abrogated the neuroprotective role of BDNF in hypoxic-hypoglycemic hippocampal neurons. Our results suggest that exogenous BDNF alleviates hypoxic-ischemic brain injury through the Trkb/MiR-134 pathway. These findings may help to identify a potential therapeutic agent for the treatment of hypoxic-ischemic brain injury.

Global emissions of the hydrofluorocarbons (HFCs) HFC-365mfc, HFC-245fa, HFC-227ea, and HFC-236fa based on atmospheric observations

NASA Astrophysics Data System (ADS)

Vollmer, M. K.; Miller, B. R.; Rigby, M. L.; Reimann, S.; Muhle, J.; Agage, Soge, Snu Members, Kopri Members

2010-12-01

We report on the atmospheric measurements and global emissions of the hydrofluorocarbons (HFCs) HFC-365mfc (CH3CH2CF2CF3, 1,1,1,3,3-pentafluorobutane), HFC-245fa (CHF2CH2CF3, 1,1,1,3,3-pentafluoropropane), HFC-227ea (CF3CHFCF3, 1,1,1,2,3,3,3-heptafluoropropane), and HFC-236fa (CF3CH2CF3, 1,1,1,3,3,3-hexafluoropropane). These measurements are from in-situ observations at stations of AGAGE (Advanced Global Atmospheric Gases Experiment) and SOGE (System for Observations of Halogenated Greenhouse Gases in Europe), and from the Korean station Gosan. We also report on flask sample measurements from the Antarctic stations King Sejong and Troll, and extend our records back to the 1970s using archived air samples of both hemispheres. All data are used in a global 12-box 2-dimensional atmospheric transport model to derive global abundances and emission estimates. All four HFCs have strongly increased in the atmosphere in recent years with growth rates at nearly 10 %, resulting in dry air mole fractions at the end of 2009 of 0.49 ppt for HFC-365mfc, 1.00 ppt for HFC-245fa, and 0.51 ppt for HFC-227ea. HFC-236fa, for which we report the first atmospheric measurements, is less abundant and has grown to 0.069 ppt at the end of 2009. Our model results show rapidly growing emissions of HFC-365mfc and HFC-245fa after 2002 but surprisingly these have now started to decline to globally 2.7 kt/yr (HFC-365mfc) and 6.1 kt/yr (HFC-245fa). On the other hand HFC-227ea and HFC-236fa show uninterrupted growth in their emissions of 2.5 kt/yr and 0.2 kt/yr at the end of 2009.

Cryogenic Optical Refrigeration

DTIC Science & Technology

2012-03-22

Applications of Laser Cooling of Solids, 1st ed. (Wiley-VCH, 2009). 12. M. Sheik- Bahae and R. I . Epstein, “Optical refrigeration,” Nat. Photonics 1(12), 693–699...2007). Advances in Optics and Photonics 4, 78–107 (2012) doi:10.1364/AOP.4.000078 99 13. M. Sheik- Bahae and R. I . Epstein, “Laser cooling of solids...Sheik- Bahae and R. I . Epstein, “Can laser light cool semiconductors,” Phys. Rev. Lett. 92(24), 247403 (2004). 18. P. Asbeck, “Self-absorption effects

Computer Programs for Calculating the Isentropic Flow Properties for Mixtures of R-134a and Air

NASA Technical Reports Server (NTRS)

Kvaternik, Raymond G.

2000-01-01

Three computer programs for calculating the isentropic flow properties of R-134a/air mixtures which were developed in support of the heavy gas conversion of the Langley Transonic Dynamics Tunnel (TDT) from dichlorodifluoromethane (R-12) to 1,1,1,2 tetrafluoroethane (R-134a) are described. The first program calculates the Mach number and the corresponding flow properties when the total temperature, total pressure, static pressure, and mole fraction of R-134a in the mixture are given. The second program calculates tables of isentropic flow properties for a specified set of free-stream Mach numbers given the total pressure, total temperature, and mole fraction of R-134a. Real-gas effects are accounted for in these programs by treating the gases comprising the mixture as both thermally and calorically imperfect. The third program is a specialized version of the first program in which the gases are thermally perfect. It was written to provide a simpler computational alternative to the first program in those cases where real-gas effects are not important. The theory and computational procedures underlying the programs are summarized, the equations used to compute the flow quantities of interest are given, and sample calculated results that encompass the operating conditions of the TDT are shown.

Cosmologically allowed regions for the axion decay constant Fa

NASA Astrophysics Data System (ADS)

Kawasaki, Masahiro; Sonomoto, Eisuke; Yanagida, Tsutomu T.

2018-07-01

If the Peccei-Quinn symmetry is already broken during inflation, the decay constant Fa of the axion can be in a wide region from 1011GeV to 1018GeV for the axion being the dominant dark matter. In this case, however, the axion causes the serious cosmological problem, isocurvature perturbation problem, which severely constrains the Hubble parameter during inflation. The constraint is relaxed when Peccei-Quinn scalar field takes a large value ∼Mp (Planck scale) during inflation. In this letter, we point out that the allowed region of the decay constant Fa is reduced to a rather narrow region for a given tensor-to-scalar ratio r when Peccei-Quinn scalar field takes ∼Mp during inflation. For example, if the ratio r is determined as r ≳10-3 in future measurements, we can predict Fa ≃ (0.1- 1.4) ×1012GeV for domain wall number NDW = 6.

The Effect of Temperature Glide of R407C Refrigerant on the Power of Evaporator in Air Refrigerators / WPŁYW POŚLIZGU Temperatury Czynnika CHŁODNICZEGO R407C NA Moc Parownika CHŁODZIARKI Powietrza

NASA Astrophysics Data System (ADS)

Nowak, Bernard; Życzkowski, Piotr

2013-12-01

The article discusses the effect of the phenomenon of temperature glide of zeotropic refrigerants on thermal power of an evaporator in an air compression refrigerator. Zeotropic mixtures are subject to phase transitions, the process of which significantly differs from that of homogeneous refrigerants. In contrast to homogeneous refrigerants, where boiling and condensing processes take place at a constant temperature, for the zeotropic mixtures it is essential to know the vapor quality to unambiguously determine the temperature at which the evaporation process is initiated. The R407C refrigerant serves as an example to describe the method of determining the initial temperature of the evaporation process taking into account the effect of temperature glide. The developed formula (7) has been based on a proven linear course of isobars in the two-phase region (Fig. 5) and thus determining a polynomial describing their angle of inclination (8). In addition, temperature calculation formulas (9) and specific enthalpy (10) of dry saturated vapor of the R407C refrigerant have been presented as well. This approach allows to determine the temperature of the R407C refrigerant at the inlet to the evaporator without the required knowledge of its vapor quality. The previously used simplified methods for determining the temperature of a refrigerant at the inlet to the evaporator result in considerable deviations in calculated power of the evaporator compared with its actual value. The presented calculation example involving mine air compression refrigerator of TS-450P type shows that relative deviations of the evaporator thermal power may even exceed 20%. This example compares two simplified methods for determining zeotropic evaporating temperature of a refrigerant used in comparative calculations of refrigerants with the method presented in this article. W artykule przedstawiono wpływ zjawiska poślizgu temperatury zeotropowych czynników chłodniczych na moc cieplną parownika sprężarkowej chłodziarki powietrza. Mieszaniny zeotropowe podlegają przemianom fazowym, których przebieg znacznie różni się od czynników jednorodnych. W odróżnieniu od jednorodnych czynników chłodniczych, których procesy wrzenia i skraplania odbywają się przy stałej temperaturze, dla mieszanin zeotropowych do jednoznacznego określenia temperatury początku procesu parowania niezbędna jest znajomość stopnia suchości pary. Na przykładzie czynnika chłodniczego R407Copisano metodę wyznaczania temperatury początkowej procesu parowania uwzględniającą zjawisko poślizgu temperatury. Opracowana zależność (7) powstała w oparciu o udowodniony liniowy przebieg izobar w obszarze pary mokrej (rys. 5) i określeniu na tej podstawie wielomianu opisującego ich kąt nachylenia (8). Dodatkowo przedstawiono wzory obliczeniowe temperatury (9) oraz entalpii właściwej (10) pary nasyconej suchej czynnika chłodniczego R407C. Takie podejście do problemu pozwala na wyznaczenie temperatury czynnika chłodniczego R407C na wlocie do parownika bez wymaganej znajomości stopnia suchości pary czynnika. Dotychczas stosowane uproszczone metody wyznaczania temperatury czynnika chłodniczego na wlocie do parownika powodują znaczne odstępstwa obliczonej na ich podstawie mocy parownika od jego wartości rzeczywistej. Przedstawiony przykład obliczeniowy dotyczący górniczej sprężarkowej chłodziarki powietrza pośredniego działania typu TS-450P pokazuje, że odchyłki względne mocy cieplnej parownika mogą przekraczać nawet ponad 20%. W przykładzie obliczeniowym porównano dwie uproszczone metody określenia temperatury parowania zeotropowego czynnika chłodniczego stosowane w obliczeniach porównawczych czynników chłodniczych z metodą zaprezentowaną w niniejszym artykule.

NASA Advanced Refrigerator/Freezer Technology Development Project Overview

NASA Technical Reports Server (NTRS)

Cairelli, J. E.

1995-01-01

NASA Lewis Research Center (LeRC) has recently initiated a three-year project to develop the advanced refrigerator/freezer (R/F) technologies needed to support future life and biomedical sciences space experiments. Refrigerator/freezer laboratory equipment, most of which needs to be developed, is enabling to about 75 percent of the planned space station life and biomedical science experiments. These experiments will require five different classes of equipment; three storage freezers operating at -20 C, -70 C and less than 183 C, a -70 C freeze-dryer, and a cryogenic (less than 183 C) quick/snap freezer. This project is in response to a survey of cooling system technologies, performed by a team of NASA scientists and engineers. The team found that the technologies, required for future R/F systems to support life and biomedical sciences spaceflight experiments, do not exist at an adequate state of development and concluded that a program to develop the advanced R/F technologies is needed. Limitations on spaceflight system size, mass, and power consumption present a significant challenge in developing these systems. This paper presents some background and a description of the Advanced R/F Technology Development Project, project approach and schedule, general description of the R/F systems, and a review of the major R/F equipment requirements.

Prediction of intramuscular fat content and major fatty acid groups of lamb M. longissimus lumborum using Raman spectroscopy.

PubMed

Fowler, Stephanie M; Ponnampalam, Eric N; Schmidt, Heinar; Wynn, Peter; Hopkins, David L

2015-12-01

A hand held Raman spectroscopic device was used to predict intramuscular fat (IMF) levels and the major fatty acid (FA) groups of fresh intact ovine M. longissimus lumborum (LL). IMF levels were determined using the Soxhlet method, while FA analysis was conducted using a rapid (KOH in water, methanol and sulphuric acid in water) extraction procedure. IMF levels and FA values were regressed against Raman spectra using partial least squares regression and against each other using linear regression. The results indicate that there is potential to predict PUFA (R(2)=0.93) and MUFA (R(2)=0.54) as well as SFA values that had been adjusted for IMF content (R(2)=0.54). However, this potential was significantly reduced when correlations between predicted and observed values were determined by cross validation (R(2)cv=0.21-0.00). Overall, the prediction of major FA groups using Raman spectra was more precise (relative reductions in error of 0.3-40.8%) compared to the null models. Copyright © 2015 Elsevier Ltd. All rights reserved.

Dissociating prefrontal circuitry in intelligence and memory: neuropsychological correlates of magnetic resonance and diffusion tensor imaging.

PubMed

Nestor, Paul G; Ohtani, Toshiyuki; Bouix, Sylvain; Hosokawa, Taiga; Saito, Yukiko; Newell, Dominick T; Kubicki, Marek

2015-12-01

We examined intelligence and memory in 25 healthy participants who had both prior magnetic resonance imaging (MRI) of gray matter volumes of medial orbital frontal cortex (mOFC) and rostral anterior cingulate cortex (rACC), along with diffusion tensor imaging (DTI) of posterior and anterior mOFC-rACC white matter microstructure, as assessed by fractional anisotropy (FA). Results showed distinct relationships between these basic structural brain parameters and higher cognition, highlighted by a highly significant correlation of left rACC gray matter volume with memory, and to a lesser extent, though still statistically significant, correlation of left posterior mOFC-rACC FA with intelligence. Regression analyses showed that left posterior mOFC-rACC connections and left rACC gray matter volume each contributed to intelligence, with left posterior mOFC-rACC FA uniquely accounting for between 20.43 and 24.99% of the variance in intelligence, in comparison to 13.54 to 17.98% uniquely explained by left rACC gray matter volume. For memory, only left rACC gray matter volume explained neuropsychological performance, uniquely accounting for a remarkably high portion of individual variation, ranging from 73.61 to 79.21%. These results pointed to differential contributions of white mater microstructure connections and gray matter volumes to individual differences in intelligence and memory, respectively.

Relating instrumental texture, determined relating instrumental texture, determined attachments, to sensory analysis of rainbow trout, Oncorhynchus mykiss, fillets

USDA-ARS?s Scientific Manuscript database

Texture is one of the most important quality attributes of fish fillets, and accurate assessment of variation in this attribute, as affected by storage and handling, is critical in providing consistent quality product. Trout fillets received 4 treatments: 3-d refrigeration (R3), 7-d refrigeration (R...

Elliptic Integrals in the Minkowski Plane

DTIC Science & Technology

1991-05-09

factorial Pochhammer notation F(a + k) (a)k - (a) Let F(a, b , c denote the hypergeometric function. Assume c - a - b = d , where d is a positive...integer. Then in a neighborhood of C = 1 , ((d) F(a+ b+d) d-1 (a)n (b)n )n(22) F(a , b , a + b + d , () = E~ )rb+ 0-’)n( ) r(a +d) r(b +d) n =O0( ’d’ n...axes a , b and eccentriaty e = c where c = Ta2 - b2 . Let P denote one of the foci of the ellipse. Then (26) 1 1 1 2 and(26) ar+(K, P) 2 -er F(- 1

MicroRNA-134 Contributes to Glucose-Induced Endothelial Cell Dysfunction and This Effect Can Be Reversed by Far-Infrared Irradiation

PubMed Central

Wang, Yen-Li; Chang, Shih-Ting; Liao, Ko-Hsun; Lo, Hung-Hao; Chiu, Ya-Lin; Hsieh, Tsung-Han; Huang, Tse-Shun; Lin, Chin-Sheng; Cheng, Shu-Meng; Cheng, Cheng-Chung

2016-01-01

Diabetes mellitus (DM) is a metabolic disease that is increasing worldwide. Furthermore, it is associated with the deregulation of vascular-related functions, which can develop into major complications among DM patients. Endothelial colony forming cells (ECFCs) have the potential to bring about medical repairs because of their post-natal angiogenic activities; however, such activities are impaired by high glucose- (HG) and the DM-associated conditions. Far-infrared radiation (FIR) transfers energy as heat that is perceived by the thermoreceptors in human skin. Several studies have revealed that FIR improves vascular endothelial functioning and boost angiogenesis. FIR has been used as anti-inflammatory therapy and as a clinical treatment for peripheral circulation improvement. In addition to vascular repair, there is increasing evidence to show that FIR can be applied to a variety of diseases, including cardiovascular disorders, hypertension and arthritis. Yet mechanism of action of FIR and the biomarkers that indicate FIR effects remain unclear. MicroRNA-134 (miR-134-5p) was identified by small RNA sequencing as being increased in high glucose (HG) treated dfECFCs (HG-dfECFCs). Highly expressed miR-134 was also validated in dmECFCs by RT-qPCR and it is associated with impaired angiogenic activities of ECFCs. The functioning of ECFCs is improved by FIR treatment and this occurs via a reduction in the level of miR-134 and an increase in the NRIP1 transcript, a direct target of miR-134. Using a mouse ischemic hindlimb model, the recovery of impaired blood flow in the presence of HG-dfECFCs was improved by FIR pretreatment and this enhanced functionality was decreased when there was miR-134 overexpression in the FIR pretreated HG-dfECFCs. In conclusion, our results reveal that the deregulation of miR-134 is involved in angiogenic defects found in DM patients. FIR treatment improves the angiogenic activity of HG-dfECFCs and dmECFCs and FIR has potential as a treatment for DM. Detection of miR-134 expression in FIR-treated ECFCs should help us to explore further the effectiveness of FIR therapy. PMID:26799933

MicroRNA-134 Contributes to Glucose-Induced Endothelial Cell Dysfunction and This Effect Can Be Reversed by Far-Infrared Irradiation.

PubMed

Wang, Hsei-Wei; Su, Shu-Han; Wang, Yen-Li; Chang, Shih-Ting; Liao, Ko-Hsun; Lo, Hung-Hao; Chiu, Ya-Lin; Hsieh, Tsung-Han; Huang, Tse-Shun; Lin, Chin-Sheng; Cheng, Shu-Meng; Cheng, Cheng-Chung

2016-01-01

Diabetes mellitus (DM) is a metabolic disease that is increasing worldwide. Furthermore, it is associated with the deregulation of vascular-related functions, which can develop into major complications among DM patients. Endothelial colony forming cells (ECFCs) have the potential to bring about medical repairs because of their post-natal angiogenic activities; however, such activities are impaired by high glucose- (HG) and the DM-associated conditions. Far-infrared radiation (FIR) transfers energy as heat that is perceived by the thermoreceptors in human skin. Several studies have revealed that FIR improves vascular endothelial functioning and boost angiogenesis. FIR has been used as anti-inflammatory therapy and as a clinical treatment for peripheral circulation improvement. In addition to vascular repair, there is increasing evidence to show that FIR can be applied to a variety of diseases, including cardiovascular disorders, hypertension and arthritis. Yet mechanism of action of FIR and the biomarkers that indicate FIR effects remain unclear. MicroRNA-134 (miR-134-5p) was identified by small RNA sequencing as being increased in high glucose (HG) treated dfECFCs (HG-dfECFCs). Highly expressed miR-134 was also validated in dmECFCs by RT-qPCR and it is associated with impaired angiogenic activities of ECFCs. The functioning of ECFCs is improved by FIR treatment and this occurs via a reduction in the level of miR-134 and an increase in the NRIP1 transcript, a direct target of miR-134. Using a mouse ischemic hindlimb model, the recovery of impaired blood flow in the presence of HG-dfECFCs was improved by FIR pretreatment and this enhanced functionality was decreased when there was miR-134 overexpression in the FIR pretreated HG-dfECFCs. In conclusion, our results reveal that the deregulation of miR-134 is involved in angiogenic defects found in DM patients. FIR treatment improves the angiogenic activity of HG-dfECFCs and dmECFCs and FIR has potential as a treatment for DM. Detection of miR-134 expression in FIR-treated ECFCs should help us to explore further the effectiveness of FIR therapy.

Flammability Indices for Refrigerants

NASA Astrophysics Data System (ADS)

Kataoka, Osami

This paper introduces a new index to classify flammable refrigerants. A question on flammability indices that ASHRAE employs arose from combustion test results of R152a and ammonia. Conventional methods of not only ASHRAE but also ISO and Japanese High-pressure gas safety law to classify the flammability of refrigerants are evaluated to show why these methods conflict with the test results. The key finding of this paper is that the ratio of stoichiometric concentration to LFL concentration (R factor) represents the test results most precisely. In addition, it has excellent correlation with other flammability parameters such as flame speed and pressure rise coefficient. Classification according to this index gives reasonable flammability order of substances including ammonia, R152a and carbon monoxide. Theoretical background why this index gives good correlation is also discussed as well as the insufficient part of this method.

Diffusion properties of NAA in human corpus callosum as studied with diffusion tensor spectroscopy.

PubMed

Upadhyay, Jaymin; Hallock, Kevin; Erb, Kelley; Kim, Dae-Shik; Ronen, Itamar

2007-11-01

In diffusion tensor imaging (DTI) the anisotropic movement of water is exploited to characterize microstructure. One confounding issue of DTI is the presence of intra- and extracellular components contributing to the measured diffusivity. This causes an ambiguity in determining the underlying cause of diffusion properties, particularly the fractional anisotropy (FA). In this study an intracellular constituent, N-acetyl aspartate (NAA), was used to probe intracellular diffusion, while water molecules were used to probe the combined intra- and extracellular diffusion. NAA and water diffusion measurements were made in anterior and medial corpus callosum (CC) regions, which are referred to as R1 and R2, respectively. FA(NAA) was found to be greater than FA(Water) in both CC regions, thus indicating a higher degree of anisotropy within the intracellular space in comparison to the combined intra- and extracellular spaces. A decreasing trend in the FA of NAA and water was observed between R1 and R2, while the radial diffusivity (RD) for both molecules increased. The increase in RD(NAA) is particularly significant, thus explaining the more significant decrease in FA(NAA) between the two regions. It is suggested that diffusion tensor spectroscopy of NAA can potentially be used to further characterize microscopic anatomic organization in white matter. Copyright 2007 Wiley-Liss, Inc.

Characterizing Intraorbital Optic Nerve Changes on Diffusion Tensor Imaging in Thyroid Eye Disease Before Dysthyroid Optic Neuropathy.

PubMed

Lee, Hwa; Lee, Young Hen; Suh, Sang-Il; Jeong, Eun-Kee; Baek, Sehyun; Seo, Hyung Suk

The aim of this study was to determine whether the optic nerve is affected by thyroid eye disease (TED) before the development of dysthyroid optic neuropathy with diffusion-tensor imaging (DTI). Twenty TED patients and 20 controls were included. The mean, axial, and radial diffusivities and fractional anisotropy (FA) value were measured at the optic nerves in DTI. Extraocular muscle diameters were measured on computed tomography. The diffusivities and FA of the optic nerves were compared between TED and controls and between active and inactive stages of TED. The correlations between these DTI parameters and the clinical features were determined. The mean, axial, and radial diffusivities were lower in TED compared with the controls (P < 0.05). In contrast, FA was higher in TED (P = 0.001). Radial diffusivity was lower in the active stage of TED than the inactive stage (P = 0.035). The FA was higher in the TED group than in the control group (P = 0.021) and was positively correlated with clinical activity score (r = 0.364, P = 0.021), modified NOSPECS score (r = 0.469, P = 0.002), and extraocular muscle thickness (r = 0.325, P = 0.041) in the TED group. Radial diffusivity was negatively correlated with modified NOSPECS score (r = -0.384, P = 0.014), and axial diffusivity was positively correlated with exophthalmos degree (r = 0.363, P = 0.025). The diffusivities and FA reflected changes in the optic nerve before dysthyroid optic neuropathy in TED. The FA, in particular, reflected TED activity and severity.

Facial asymmetry as an indicator of psychological, emotional, and physiological distress.

PubMed

Shackelford, T K; Larsen, R J

1997-02-01

Fluctuating asymmetry (FA) is deviation from bilateral symmetry in morphological traits with asymmetry values that are normally distributed with a mean of 0. FA is produced by genetic or environmental perturbations of developmental design and may play a role in human sexual selection. K. Grammer and R. Thornhill (1994) found that facial FA negatively covaries with observer ratings of attractiveness, dominance, sexiness, and health. Using self-reports, observer ratings, daily diary reports, and psychophysiological measures, the authors assessed the relationship between facial FA and health in 2 samples of undergraduates (N = 101). Results partially replicate and extend those of K. Grammer and R. Thornhill (1994) and suggest that facial FA may signal psychological, emotional, and physiological distress. Discussion integrates the authors' findings with previous research on FA and suggests future research needed to clarify the role of FA in human sexual selection.

R744 ejector technology future perspectives

NASA Astrophysics Data System (ADS)

Hafner, Armin; Banasiak, Krzysztof

2016-09-01

Carbon Dioxide, CO2 (R744) was one of the first commonly applied working fluids in the infancy of refrigeration more than 100 years ago. In contrast to ammonia it mainly disappeared after the first generation of synthetic refrigerants have been introduced to the market after 1930. One reason was that the transition from low-rpm belt driven compressors towards the direct electrical motor driven compressors (50-60 Hz) was not performed for CO2 compressors before the revival introduced by Gustav Lorentzen in the 90is of last century. Since 1988 an enormous R & D effort has been made to further develop CO2 refrigeration technology in spite of the opposition from the chemical industry. Today CO2 refrigeration and heat pumping technologies are accepted as viable and sustainable alternatives for several applications like commercial refrigeration, transport refrigeration, vehicle air conditioning & heat pumping, domestic hot water heat pumps and industrial applications. For some applications, the current threshold to introduce R744 technology can be overcome when the system design takes into account the advantage of the thermo dynamical- and fluid properties of CO2. I.e. the system is designed for transcritical operation with all it pros and cons and takes into consideration how to minimize the losses, and to apply the normally lost expansion work. Shortcut-designs, i.e. drop in solutions, just replacing the H(C)FC refrigeration unit with an CO2 systems adapted for higher system pressures will not result in energy efficient products. CO2 systems do offer the advantage of enabling flooded evaporators supported with adapted ejector technology. These units offer high system performances at low temperature differences and show low temperature air mal-distributions across evaporators. This work gives an overview for the development possibilities for several applications during the next years. Resulting in a further market share increase of CO2 refrigeration and heat pump systems, as energy efficient alternatives to current systems not applying natural working fluids.

A First-Order Methodology for Calculating Probability of Mission Success

DTIC Science & Technology

1979-01-31

Af(A)/2 + T- fA1 A2 1/8 R(T) (A) -T Af(A)4,(A) + T Af(A)[Af(A) + 4)(A)1$3 A 11/4. 61~ a 2 T R T 2f2 ()+T4f2 ()7A2 -4-A2]/ R 2 f(A) T 2(1 + T 2(3A 2/2...Library ATTN: W. Wright, Jr. ATTN: P. Haas Management Science Associates ATTN: K. Kaplan Rand Corp. ATTN: A. Laupa Martin Marietta Corp, ATTN: C. Mow ATTN

Global Emissions of Refrigerants HCFC-22 and HFC-134a: Unforeseen Seasonal Contributions

NASA Astrophysics Data System (ADS)

Xiang, B.; Patra, P. K.; Montzka, S. A.; Miller, S. M.; Elkins, J. W.; Moore, F.; Atlas, E. L.; Miller, B. R.; Prinn, R. G.; Wofsy, S. C.

2014-12-01

HCFC-22 (CHClF2) and HFC-134a (CH2FCF3) are two major gases currently used worldwide in domestic and commercial refrigeration and air conditioning. HCFC-22 contributes to stratospheric ozone depletion and both species are potent greenhouse gases, and their global emissions continue to rise at the present. In this work, we study aircraft based in-situ observations of HCFC-22 and HFC-134a over the Pacific Ocean in a three-year span (HIaper Pole-to-Pole Observation of carbon cycle and greenhouse gases study, HIPPO 2009-2011) and combine these data with long-term observations from global surface sites (NOAA and AGAGE networks). We find a steady increase in global annual emissions of HCFC-22 and HFC-134a for the past two decades (on average 3% and 4% per year, respectively). Emissions of HFC-134a since 2000 are consistently higher, with 60% more in recent years (2009-2011), compared to the United Nations Framework Convention on Climate Change (UNFCCC) inventory. Using both HIPPO and surface data, we quantify and verify enhanced summertime emissions of HFC-134a and HCFC-22 that are about three times those in the wintertime. This unforeseen large seasonal contribution indicates unaccounted mechanisms controlling refrigerant gas emissions, missing in the existing inventory estimates. Possible mechanisms for greater refrigerant leakages in the summer are: 1) higher vapor pressure in the sealed compartment of the system at summer high temperatures (saturated vapor pressure is ~ 3 times at 303 K compared to that at 273 K for both species), and 2) more frequent use of refrigeration and air conditioners in the summer (vapor pressure in the compressor line is higher when in use than not in use). Our results suggest that the engineering of the refrigeration and air conditioning systems can greatly influence the release of these two species to the atmosphere.

Distribution and survival of Vibrio vulnificus genotypes in postharvest Gulf Coast (USA) oysters under refrigeration.

PubMed

Wood, R R; Arias, C R

2012-07-01

  The effect of refrigeration on the seafood-borne pathogen Vibrio vulnificus was investigated in terms of genotype selection and persistence in refrigerated oysters.   Naturally occurring numbers of V. vulnificus in oysters from two different locations were compared during a 2-week period under refrigeration conditions. At different time points, V. vulnificus isolates were recovered from oysters and ascribed to 16S rRNA gene type A, B or AB using restriction fragment length polymorphism. Initial V. vulnificus numbers were higher than 10(4) most probable number (MPN) g(-1) and remained unchanged throughout the duration of the study. 16S rRNA gene type B isolates accounted for 53% of the isolates recovered. Amplified fragment length polymorphism analysis confirmed the high genetic variability previously observed within this species but revealed the presence of two main genetic groups within the species that matched 16S rRNA gene ascription.   Vibrio vulnificus numbers in oysters did not significantly declined over the shelf life of the product and refrigeration did not select for specific V. vulnificus types.   The prevalence of V. vulnificus 16S rRNA gene type B in oysters was higher than previously reported from the same geographic area and was not significantly reduced during the storage period. Vibrio vulnificus is divided into two clear genotypes, regardless of the genetic marker used. © 2012 The Authors. Journal of Applied Microbiology © 2012 The Society for Applied Microbiology.

Heavy Gas Conversion of the NASA Langley Transonic Dynamics Tunnel

NASA Technical Reports Server (NTRS)

Corliss, James M.; Cole, Stanley, R.

1998-01-01

The heavy gas test medium has recently been changed in the Transonic Dynamics Tunnel (TDT) at the NASA Langley Research Center. A NASA Construction of Facilities project has converted the TDT heavy gas from dichlorodifluoromethane (R12) to 1,1,1,2 tetrafluoroethane (R134a). The facility s heavy gas processing system was extensively modified to implement the conversion to R134a. Additional system modifications have improved operator interfaces, hardware reliability, and quality of the research data. The facility modifications included improvements to the heavy gas compressor and piping, the cryogenic heavy gas reclamation system, and the heavy gas control room. A series of wind tunnel characterization and calibration tests are underway. Results of the flow characterization tests show the TDT operating envelope in R134a to be very similar to the previous operating envelope in R12.

Advanced Refrigerator/Freezer Technology Development. Technology Assessment

NASA Technical Reports Server (NTRS)

Gaseor, Thomas; Hunter, Rick; Hamill, Doris

1996-01-01

The NASA Lewis Research Center, through contract with Oceaneering Space Systems, is engaged in a project to develop advanced refrigerator/freezer (R/F) technologies for future Life and Biomedical Sciences space flight missions. The first phase of this project, a technology assessment, has been completed to identify the advanced R/F technologies needed and best suited to meet the requirements for the five R/F classifications specified by Life and Biomedical Science researchers. Additional objectives of the technology assessment were to rank those technologies based on benefit and risk, and to recommend technology development activities that can be accomplished within this project. This report presents the basis, the methodology, and results of the R/F technology assessment, along with technology development recommendations.

Tapered pulse tube for pulse tube refrigerators

DOEpatents

Swift, Gregory W.; Olson, Jeffrey R.

1999-01-01

Thermal insulation of the pulse tube in a pulse-tube refrigerator is maintained by optimally varying the radius of the pulse tube to suppress convective heat loss from mass flux streaming in the pulse tube. A simple cone with an optimum taper angle will often provide sufficient improvement. Alternatively, the pulse tube radius r as a function of axial position x can be shaped with r(x) such that streaming is optimally suppressed at each x.

Persistence of Antibiotic Resistance Plasmids in Biofilms

DTIC Science & Technology

2014-10-01

from a particular file #e.g. here everything from “data1.xls” will have identifier of “Rep1” r1<-collate(ls( patt ="*rep1"),TRUE,lastVal="Rep1") r2...collate(ls( patt ="*rep2"),TRUE,lastVal="Rep2") #merge the data from the two files allOutput<-rbind(r1,r2) #at this point allOutput can be used

A force field for 3,3,3-fluoro-1-propenes, including HFO-1234yf.

PubMed

Raabe, Gabriele; Maginn, Edward J

2010-08-12

The European Union (EU) legislation 2006/40/EC bans from January 2011 the cooperative marketing of new car types that use refrigerants in their heating, ventilation, and air conditioning (HVAC) systems with global warming potentials (GWP) higher than 150. Thus, the phase-out of the presently used tetrafluoroethane refrigerant R134a necessitates the adoption of alternative refrigerants. Fluoropropenes such as 2,3,3,3-tetrafluoro-1-propene (HFO-1234yf) are currently regarded as promising low GWP refrigerants, but the lack of experimental data on their thermophysical properties hampers independent studies on their performance in HVAC systems or in other technical applications. In principle, molecular modeling can be used to predict the relevant properties of refrigerants, but adequate intermolecular potential functions ("force fields") are lacking for fluoropropenes. Thus, we developed a transferable force field for fluoropropenes composed of CF(3)-, -CF=, -CH=, CF(2)=, and CH(2)= groups and applied the force field to study 3,3,3 trifluoro-1-propene (HFO-1243zf), 2,3,3,3-tetrafluoro-1-propene (HFO-1234yf), and hexafluoro-1-propene (HFO-1216). We performed Gibbs ensemble simulations on these three fluoropropenes to compute the vapor pressure, saturated densities, and heats of vaporization. In addition, molecular dynamics simulations were conducted to provide predictions for the density, thermal expansivity, isobaric heat capacity, and transport properties of liquid HFO-1234yf in the temperature range from 263.15 to 310 K and pressures up to 2 MPa. Agreement between simulation results and experimental data and/or correlations (when available) was good, thereby validating the predictive ability of the force field.

Vapor pressures of new fluorocarbons

NASA Astrophysics Data System (ADS)

Kubota, H.; Yamashita, T.; Tanaka, Y.; Makita, T.

1989-05-01

The vapor pressures of four fluorocarbons have been measured at the following temperature ranges: R123 (2,2-dichloro-l,l,l-trifluoroethane), 273 457 K; R123a (1,2-dichloro-1,1,2-trifluoroethane), 303 458 K; R134a (1,1,1,2-tetrafluoroethane), 253 373 K; and R132b (l,2-dichloro-l,l-difluoroethane), 273 398 K. Determinations of the vapor pressure were carried out by a constant-volume apparatus with an uncertainty of less than 1.0%. The vapor pressures of R123 and R123a are very similar to those of R11 over the whole experimental temperature range, but the vapor pressures of R134a and R132b differ somewhat from those of R12 and R113, respectively, as the temperature increases. The numerical vapor pressure data can be fitted by an empirical equation using the Chebyshev polynomial with a mean deviation of less than 0.3 %.

Research and Development Opportunities for Joining Technologies in HVAC&R

DOE Office of Scientific and Technical Information (OSTI.GOV)

Goetzler, William; Guernsey, Matt; Young, Jim

The Building Technologies Office (BTO) works with researchers and industry partners to develop and deploy technologies that can substantially reduce energy consumption and greenhouse gas (GHG) emissions in residential and commercial buildings. This opportunity assessment aims to advance BTO’s energy savings, GHG reduction, and other program goals by identifying research and development (R&D) initiatives for joining technologies in heating, ventilation, air-conditioning, and refrigeration (HVAC&R) systems. Improving joining technologies for HVAC&R equipment has the potential to increase lifetime equipment operating efficiency, decrease equipment and project cost, and most importantly reduce hydroflourocarbon (HFC) refrigerant leakage to support HFC phasedown and GHG reductionmore » goals.« less

A Numerical and Experimental Study of Ejector Internal Flow Structure and Geometry Modification for Maximized Performance

NASA Astrophysics Data System (ADS)

Falsafioon, Mehdi; Aidoun, Zine; Poirier, Michel

2017-12-01

A wide range of industrial refrigeration systems are good candidates to benefit from the cooling and refrigeration potential of supersonic ejectors. These are thermally activated and can use waste heat recovery from industrial processes where it is abundantly generated and rejected to the environment. In other circumstances low cost heat from biomass or solar energy may also be used in order to produce a cooling effect. Ejector performance is however typically modest and needs to be maximized in order to take full advantage of the simplicity and low cost of the technology. In the present work, the behavior of ejectors with different nozzle exit positions has been investigated using a prototype as well as a CFD model. The prototype was used in order to measure the performance advantages of refrigerant (R-134a) flowing inside the ejector. For the CFD model, it is assumed that the ejectors are axi-symmetric along x-axis, thus the generated model is in 2D. The preliminary CFD results are validated with experimental data over a wide range of conditions and are in good accordance in terms of entrainment and compression ratios. Next, the flow patterns of four different topologies are studied in order to discuss the optimum geometry in term of ejector entrainment improvement. Finally, The numerical simulations were used to find an optimum value corresponding to maximized entrainment ratio for fixed operating conditions.

PERFORMANCE OF A TWO-CYCLE REFRIGERATOR/FREEZER USING HFC REFRIGERANTS

EPA Science Inventory

A two-cycle 18 ft3 (0.51 m3) refrigerator/freezer (R/F) was tested utilizing American National Standards Institute (ANSI)/AHAM (1988) standards for energy consumption testing. A 34.9% energy consumption reduction was realized. This work presents a proven method of reducing the ...

Functional Dependence of Thermodynamic and Thermokinetic Parameters of Refrigerants Used in Mine Air Refrigerators. Part 1 - Refrigerant R407C

NASA Astrophysics Data System (ADS)

Nowak, Bernard; Życzkowski, Piotr; Łuczak, Rafał

2017-03-01

The authors of this article dealt with the issue of modeling the thermodynamic and thermokinetic properties (parameters) of refrigerants. The knowledge of these parameters is essential to design refrigeration equipment, to perform their energy efficiency analysis, or to compare the efficiency of air refrigerators using different refrigerants. One of the refrigerants used in mine air compression refrigerators is R407C. For this refrigerant, 23 dependencies were developed, determining its thermodynamic and thermokinetic parameters in the states of saturated liquid, dry saturated vapour, superheated vapor, subcooled liquid, and in the two-phase region. The created formulas have been presented in Tables 2, 5, 8, 10 and 12, respectively. It should be noted that the scope of application of these formulas is wider than the range of changes of that refrigerant during the normal operation of mine refrigeration equipment. The article ends with the statistical verification of the developed dependencies. For this purpose, for each model correlation coefficients and coefficients of determination were calculated, as well as absolute and relative deviations between the given values from the program REFPROP 7 (Lemmon et al., 2002) and the calculated ones. The results of these calculations have been contained in Tables 14 and 15.

Department of the Air Force Supporting Data for Fiscal Year 1986 Budget Estimates Submitted to Congress February 1985, Descriptive Summaries, Research, Development, Test and Evaluation

DTIC Science & Technology

1985-02-01

Wk B«U Oil &b 0 i »>BCbBB«00 fa s 0 0 0 0 * « •HR« i s fa •r* •T< 0 x:^>u0«to«-<-> -a fa to (J k kTJ<ri r...4J y <M •H JS o o U B 0 y 0 4J a w «M u b >n y b 0 1 0 « i o 0 •n o rH O y •P4 <M TJ 0 0 • a«M oil b •n TJ o B o 0 r^ o 4J 4-> 0 0 o 0 0...Ifc, «j 3 bXIBOn 0COU9 03 0 I . n O. O X Oil ) iHSUfO JJ 3 JJ ftJO B 0O0 9 0TJLiX0»~iU0

Evaluation of genotoxicity in workers exposed to low levels of formaldehyde in a furniture manufacturing facility.

PubMed

Peteffi, Giovana Piva; da Silva, Luciano Basso; Antunes, Marina Venzon; Wilhelm, Camila; Valandro, Eduarda Trevizani; Glaeser, Jéssica; Kaefer, Djeine; Linden, Rafael

2016-10-01

Formaldehyde (FA) is a chemical widely used in the furniture industry and has been classified as a potential human carcinogen. The purpose of this study was to evaluate the occupational exposure of workers to FA at a furniture manufacturing facility and the relationship between environmental concentrations of FA, formic acid concentration in urine, and DNA damage. The sample consisted of 46 workers exposed to FA and a control group of 45 individuals with no history of occupational exposure. Environmental concentrations of FA were determined by high-performance liquid chromatography. Urinary formic acid concentrations were determined by gas chromatography with flame ionization detector. DNA damage was evaluated by the micronucleus (MN) test performed in exfoliated buccal cells and comet assay with venous blood. The 8-h time-weighted average of FA environmental concentration ranged from 0.03 ppm to 0.09 ppm at the plant, and the control group was exposed to a mean concentration of 0.012 ppm. Workers exposed to higher environmental FA concentrations had urinary formic acid concentrations significantly different from those of controls (31.85 mg L(-1) vs. 19.35 mg L(-), p ≤ 0.01 Mann-Whitney test). Significant differences were found between control and exposed groups for the following parameters: damage frequency and damage index in the comet assay, frequency of binucleated cells in the MN test, and formic acid concentration in urine. The frequency of micronuclei, nuclear buds, and karyorrhexis did not differ between groups. There was a positive correlation between environmental concentrations of FA and damage frequency (Spearman's rank correlation coefficient [r s] = 0.24), damage index (r s = 0.21), binucleated cells (r s = 0.34), and urinary formic acid concentration (r s = 0.63). The results indicate that, although workers in the furniture manufacturing facility were exposed to low environmental levels of FA, this agent contributes to the observed increase in cytogenetic damage. In addition, urinary formic acid concentrations correlated strongly with occupational exposure to FA. © The Author(s) 2015.

High Technology Centrifugal Compressor for Commercial Air Conditioning Systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ruckes, John

2006-04-15

R&D Dynamics, Bloomfield, CT in partnership with the State of Connecticut has been developing a high technology, oil-free, energy-efficient centrifugal compressor called CENVA for commercial air conditioning systems under a program funded by the US Department of Energy. The CENVA compressor applies the foil bearing technology used in all modern aircraft, civil and military, air conditioning systems. The CENVA compressor will enhance the efficiency of water and air cooled chillers, packaged roof top units, and other air conditioning systems by providing an 18% reduction in energy consumption in the unit capacity range of 25 to 350 tons of refrigeration Themore » technical approach for CENVA involved the design and development of a high-speed, oil-free foil gas bearing-supported two-stage centrifugal compressor, CENVA encompassed the following high technologies, which are not currently utilized in commercial air conditioning systems: Foil gas bearings operating in HFC-134a; Efficient centrifugal impellers and diffusers; High speed motors and drives; and System integration of above technologies. Extensive design, development and testing efforts were carried out. Significant accomplishments achieved under this program are: (1) A total of 26 builds and over 200 tests were successfully completed with successively improved designs; (2) Use of foil gas bearings in refrigerant R134a was successfully proven; (3) A high speed, high power permanent magnet motor was developed; (4) An encoder was used for signal feedback between motor and controller. Due to temperature limitations of the encoder, the compressor could not operate at higher speed and in turn at higher pressure. In order to alleviate this problem a unique sensorless controller was developed; (5) This controller has successfully been tested as stand alone; however, it has not yet been integrated and tested as a system; (6) The compressor successfully operated at water cooled condensing temperatures Due to temperature limitations of the encoder, it could not be operated at air cooled condensing temperatures. (7) The two-stage impellers/diffusers worked well separately but combined did not match well.« less

Combined Effects of Non-Conforming Fly Ash and Recycled Masonry Aggregates on Mortar Properties

PubMed Central

Torres-Gómez, Ana Isabel; Ledesma, Enrique F.; Otero, Rocio; Fernández, José Maria; Jiménez, José Ramón; de Brito, Jorge

2016-01-01

This work evaluates the effects of using non-conforming fly ash (Nc-FA) generated in a thermoelectric power plant as filler material for mortars made with natural sand (NA) and recycled sand from masonry waste (FRMA). The incorporation of powdered recycled masonry filler (R-MF) is also tested as an alternative to siliceous filler (Si-F). Three families of mortars were designed to study: the effect of replacing Si-F with Nc-FA on mortars made with NA; the effect of replacing Si-F with Nc-FA on mortars made with 50% of NA and 50% of FRMA; and the effect of replacing Si-F with R-MF on mortars made with NA and FRMA. Replacing Si-F with Nc-FA is a viable alternative that increases the mechanical strength, the workability and durability properties and decreases the shrinkage. The use of FRMA and Nc-FA improved the mechanical strength of mortars, and it slightly increased the shrinkage. The replacement of Si-F with R-MF on mortars made with FRMA is not a good alternative, because it has a negative impact on all of the properties tested. This work can help both to reduce cement and natural resources’ consumption and to increase the recycling rate of Nc-FA and FRMA. PMID:28773849

Combined Effects of Non-Conforming Fly Ash and Recycled Masonry Aggregates on Mortar Properties.

PubMed

Torres-Gómez, Ana Isabel; Ledesma, Enrique F; Otero, Rocio; Fernández, José Maria; Jiménez, José Ramón; de Brito, Jorge

2016-08-25

This work evaluates the effects of using non-conforming fly ash (Nc-FA) generated in a thermoelectric power plant as filler material for mortars made with natural sand (NA) and recycled sand from masonry waste (FRMA). The incorporation of powdered recycled masonry filler (R-MF) is also tested as an alternative to siliceous filler (Si-F). Three families of mortars were designed to study: the effect of replacing Si-F with Nc-FA on mortars made with NA; the effect of replacing Si-F with Nc-FA on mortars made with 50% of NA and 50% of FRMA; and the effect of replacing Si-F with R-MF on mortars made with NA and FRMA. Replacing Si-F with Nc-FA is a viable alternative that increases the mechanical strength, the workability and durability properties and decreases the shrinkage. The use of FRMA and Nc-FA improved the mechanical strength of mortars, and it slightly increased the shrinkage. The replacement of Si-F with R-MF on mortars made with FRMA is not a good alternative, because it has a negative impact on all of the properties tested. This work can help both to reduce cement and natural resources' consumption and to increase the recycling rate of Nc-FA and FRMA.

Effect of myasthenic patient sera on the number and distribution of acetylcholine receptors in muscle and nerve-muscle cultures from rat. Correlations with clinical state.

PubMed

Eymard, B; de la Porte, S; Pannier, C; Berrih-Aknin, S; Morel, E; Fardeau, M; Bach, J F; Koenig, J

1988-08-01

We studied the functional activities (FA) of sera obtained from 83 myasthenic patients on rat muscle cultures. Using the same sets of cultures, two parameters were evaluated after exposure to sera: residual fraction (RF) of acetylcholine receptors (AChR) coupled to 125I-labelled alpha-bungarotoxin (alpha Bgt) (81 sera) and the number of rhodamine labelled clusters (56 sera). Two types of culture were assayed: muscle alone and nerve-muscle cocultures (12 cases). In all combinations (fluorescence, radiolabelling, muscle alone and nerve-muscle cocultures), we found a significant correlation between FA and antibody (Ab) titre, and no correlation between FA and clinical severity: only sera with a high or intermediate Ab titre were effective, whatever the clinical severity of disease. With active sera, AChR loss was about 50% whereas the disappearance of AChR clusters was quite complete, which suggests AChR redistribution induced by MG sera.

[A correlation between diffusion kurtosis imaging and the proliferative activity of brain glioma].

PubMed

Tonoyan, A S; Pronin, I N; Pitshelauri, D I; Shishkina, L V; Fadeeva, L M; Pogosbekyan, E L; Zakharova, N E; Shults, E I; Khachanova, N V; Kornienko, V N; Potapov, A A

2015-01-01

The aim of the study was to assess the capabilities of diffusion kurtosis imaging (DKI) in diagnosis of the glioma proliferative activity and to evaluate a relationship between the glioma proliferative activity index and diffusion parameters of the contralateral normal appearing white matter (CNAWM). The study included 47 patients with newly diagnosed brain gliomas (23 low grade, 13 grade III, and 11 grade IV gliomas). We determined a relationship between absolute and normalized parameters of the diffusion tensor (mean (MD), axial (AD), and radial (RD) diffusivities; fractional (FA) and relative (RA) anisotropies) and diffusion kurtosis (mean (MK), axial (AK), and radial (RK) kurtosis; kurtosis anisotropy (KA)) and the proliferative activity index in the most malignant glioma parts (p<0.05). We also established a relationship between the tensor and kurtosis parameters of CNAWM and the glioma proliferative activity index (p<0.05). The correlation between all the absolute and normalized diffusion parameters and the glioma proliferative activity index, except absolute and normalized FA and RA values, was found to be statistically significant (p<0.05). Kurtosis (MK, AK, and RK) and anisotropy (KA, FA, RA) values increased, and diffusivity (MD, AD, RD) values decreased as the glioma proliferative activity index increased. A strong correlation between the proliferative activity index and absolute RK (r=0,71; p=0.000001) and normalized values of MK (r=0.8; p=0.000001), AK (r=0.71; p=0.000001), RK (r=0.81; p=0.000001), and RD (r=-0.71; p=0.000001) was found. A weak, but statistically significant correlation between the glioma proliferative activity index and diffusion values RK (r=-0.36; p=0.014), KA (r=-0.39; p=0.007), RD (r=0.35; p=0.017), FA (r=-0.42; p=0.003), and RA (r=-0.41; p=0.004) of CNAWM was found. DKI has good capabilities to detect immunohistochemical changes in gliomas. DKI demonstrated a high sensitivity in detection of microstructural changes in the contralateral normal appearing white matter in patients with brain gliomas.

Optimal coupling and feasibility of a solar-powered year-round ejector air conditioner

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sokolov, M.; Hershgal, D.

1993-06-01

An ejector refrigeration system that uses a conventional refrigerant (R-114) is introduced as a possible mechanism for providing solar-based air-conditioning. Optimal coupling conditions between the collectors' energy output and energy requirements of the cooling system, are investigated. Operation at such optimal conditions assures maximized overall efficiency. Procedures leading to the evaluation of the performance of a real system are disclosed. Design curves for such a system with R-114 as refrigerant are provided. A multi-ejectors arrangement that provides an efficient adjustment for variations of ambient conditions, is described. Year-round air-conditioning is facilitated by rerouting the refrigerant flow through a heating modemore » of the system. Calculations are carried out for illustrative configurations in which relatively low condensing temperature (water reservoirs, cooling towers, or moderate climate) can be maintained.« less

Hereditary folate malabsorption: A positively charged amino acid at position 113 of the proton-coupled folate transporter (PCFT/SLC46A1) is required for folic acid binding

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lasry, Inbal; Berman, Bluma; Glaser, Fabian

2009-08-28

The proton-coupled folate transporter (PCFT/SLC46A1) mediates intestinal folate uptake at acidic pH. Some loss of folic acid (FA) transport mutations in PCFT from hereditary folate malabsorption (HFM) patients cluster in R113, thereby suggesting a functional role for this residue. Herein, unlike non-conservative substitutions, an R113H mutant displayed 80-fold increase in the FA transport Km while retaining parental Vmax, hence indicating a major fall in folate substrate affinity. Furthermore, consistent with the preservation of 9% of parental transport activity, R113H transfectants displayed a substantial decrease in the FA growth requirement relative to mock transfectants. Homology modeling based on the crystal structuresmore » of the Escherichia coli transporter homologues EmrD and glycerol-3-phosphate transporter revealed that the R113H rotamer properly protrudes into the cytoplasmic face of the minor cleft normally occupied by R113. These findings constitute the first demonstration that a basic amino acid at position 113 is required for folate substrate binding.« less

Enzymatic hydrolysis of chitin pretreated by rapid depressurization from supercritical 1,1,1,2-tetrafluoroethane toward highly acetylated oligosaccharides.

PubMed

Villa-Lerma, Guadalupe; González-Márquez, Humberto; Gimeno, Miquel; Trombotto, Stéphane; David, Laurent; Ifuku, Shinsuke; Shirai, Keiko

2016-06-01

The hydrolysis of chitin treated under supercritical conditions was successfully carried out using chitinases obtained by an optimized fermentation of the fungus Lecanicillium lecanii. The biopolymer was subjected to a pretreatment based on suspension in supercritical 1,1,1,2-tetrafluoroethane (scR134a), which possesses a critical temperature and pressure of 101°C and 40bar, respectively, followed by rapid depressurization to atmospheric pressure and further fibrillation. This methodology was compared to control untreated chitins and chitin subjected to steam explosion showing improved production of reducing sugars (0.18mg/mL), enzymatic hydrolysis and high acetylation (FA of 0.45) in products with degrees of polymerization between 2 and 5. Copyright © 2016 Elsevier Ltd. All rights reserved.

Neurite density index is sensitive to age related differences in the developing brain.

PubMed

Genc, Sila; Malpas, Charles B; Holland, Scott K; Beare, Richard; Silk, Timothy J

2017-03-01

White matter development during childhood and adolescence is characterised by increasing white matter coherence and organisation. Commonly used scalar metrics, such as fractional anisotropy (FA), are sensitive to multiple mechanisms of white matter change and therefore unable to distinguish between mechanisms that change during development. We investigate the relationship between age and neurite density index (NDI) from neurite orientation dispersion and density imaging (NODDI), and the age-classification accuracy of NDI compared with FA, in a developmental cohort. Diffusion-weighted imaging data from 72 children and adolescents between the ages of 4-19 was collected (M=10.42, SD=3.99, 36 male). We compared NODDI metrics against conventional DTI metrics (fractional anisotropy [FA], mean diffusivity [MD], axial diffusivity [AD] and radial diffusivity [RD]) in terms of their relationship to age. An ROC analysis was also performed to assess the ability of each metric to classify older and younger participants. NDI exhibited a stronger relationship with age (median R 2 =.60) compared with MD (median R 2 =.39), FA (median R 2 =.27), AD (median R 2 =.14), and RD (median R 2 =.35) in a high proportion of white matter tracts. When participants were divided into an older and younger group, NDI achieved the best classification (median area under the curve [AUC]=.89), followed by MD (median AUC=.81), FA (median AUC=.80), RD (median AUC=.81), and AD (median AUC=.64). Our results demonstrate the sensitivity of NDI to age-related differences in white matter microstructural organisation over development. Importantly, NDI is more sensitive to such developmental changes compared to commonly used DTI metrics. This knowledge provides justification for implementing NODDI metrics in developmental studies. Copyright © 2017 Elsevier Inc. All rights reserved.

Medial frontal white and gray matter contributions to general intelligence.

PubMed

Ohtani, Toshiyuki; Nestor, Paul G; Bouix, Sylvain; Saito, Yukiko; Hosokawa, Taiga; Kubicki, Marek

2014-01-01

The medial orbitofrontal cortex (mOFC) and rostral anterior cingulate cortex (rACC) are part of a wider neural network that plays an important role in general intelligence and executive function. We used structural brain imaging to quantify magnetic resonance gray matter volume and diffusion tensor white matter integrity of the mOFC-rACC network in 26 healthy participants who also completed neuropsychological tests of intellectual abilities and executive function. Stochastic tractography, the most effective Diffusion Tensor Imaging method for examining white matter connections between adjacent gray matter regions, was employed to assess the integrity of mOFC-rACC pathways. Fractional anisotropy (FA), which reflects the integrity of white matter connections, was calculated. Results indicated that higher intelligence correlated with greater gray matter volumes for both mOFC and rACC, as well as with increased FA for left posterior mOFC-rACC connectivity. Hierarchical regression analyses revealed that DTI-derived FA of left posterior mOFC-rACC uniquely accounted for 29%-34% of the variance in IQ, in comparison to 11%-16% uniquely explained by gray matter volume of the left rACC. Together, left rACC gray matter volume and white matter connectivity between left posterior mOFC and rACC accounted for up to 50% of the variance in general intelligence. This study is to our knowledge the first to examine white matter connectivity between OFC and ACC, two gray matter regions of interests that are very close in physical proximity, and underscores the important independent contributions of variations in rACC gray matter volume and mOFC-rACC white matter connectivity to individual differences in general intelligence.

High efficiency novel window air conditioner

DOE PAGES

Bansal, Pradeep

2015-07-24

This paper presents the technical development of a high efficiency window air conditioner. In order to achieve higher energy efficiency ratio (EER), the original capacity of the R410A unit was downgraded by replacing the original compressor with a lower capacity but higher EER compressor, while all heat exchangers and the chassis from the original unit were retained. The other subsequent major modifications included – the AC fan motor being replaced with a brushless high efficiency electronically commuted motor (ECM) motor, the capillary tube being replaced with a needle valve to better control the refrigerant flow and refrigerant set points, andmore » R410A being replaced with drop-in environmentally friendly binary mixture of R32 (85% molar concentration)/R125 (15% molar concentration). All these modifications resulted in significant EER enhancement of the modified unit.« less

High efficiency novel window air conditioner

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bansal, Pradeep

This paper presents the technical development of a high efficiency window air conditioner. In order to achieve higher energy efficiency ratio (EER), the original capacity of the R410A unit was downgraded by replacing the original compressor with a lower capacity but higher EER compressor, while all heat exchangers and the chassis from the original unit were retained. The other subsequent major modifications included – the AC fan motor being replaced with a brushless high efficiency electronically commuted motor (ECM) motor, the capillary tube being replaced with a needle valve to better control the refrigerant flow and refrigerant set points, andmore » R410A being replaced with drop-in environmentally friendly binary mixture of R32 (85% molar concentration)/R125 (15% molar concentration). All these modifications resulted in significant EER enhancement of the modified unit.« less

Subconcussive Head Impact Exposure and White Matter Tract Changes over a Single Season of Youth Football.

PubMed

Bahrami, Naeim; Sharma, Dev; Rosenthal, Scott; Davenport, Elizabeth M; Urban, Jillian E; Wagner, Benjamin; Jung, Youngkyoo; Vaughan, Christopher G; Gioia, Gerard A; Stitzel, Joel D; Whitlow, Christopher T; Maldjian, Joseph A

2016-12-01

Purpose To examine the effects of subconcussive impacts resulting from a single season of youth (age range, 8-13 years) football on changes in specific white matter (WM) tracts as detected with diffusion-tensor imaging in the absence of clinically diagnosed concussions. Materials and Methods Head impact data were recorded by using the Head Impact Telemetry system and quantified as the combined-probability risk-weighted cumulative exposure (RWE CP ). Twenty-five male participants were evaluated for seasonal fractional anisotropy (FA) changes in specific WM tracts: the inferior fronto-occipital fasciculus (IFOF), inferior longitudinal fasciculus, and superior longitudinal fasciculus (SLF). Fiber tracts were segmented into a central core and two fiber terminals. The relationship between seasonal FA change in the whole fiber, central core, and the fiber terminals with RWE CP was also investigated. Linear regression analysis was conducted to determine the association between RWE CP and change in fiber tract FA during the season. Results There were statistically significant linear relationships between RWE cp and decreased FA in the whole (R 2 = 0.433; P = .003), core (R 2 = 0.3649; P = .007), and terminals (R 2 = 0.5666; P < .001) of left IFOF. A trend toward statistical significance (P = .08) in right SLF was observed. A statistically significant correlation between decrease in FA of the right SLF terminal and RWE CP was also observed (R 2 = 0.2893; P = .028). Conclusion This study found a statistically significant relationship between head impact exposure and change of FA fractional anisotropy value of whole, core, and terminals of left IFOF and right SLF's terminals where WM and gray matter intersect, in the absence of a clinically diagnosed concussion. © RSNA, 2016.

Vapor pressures of new fluorocarbons

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kubota, H.; Yamashita, T.; Tanaka, Y.

1989-05-01

The vapor pressures of four fluorocarbons have been measured at the following temperature ranges: R123 (2,2-dichloro-1,1,1-trifluoroethane), 273-457 K; R123a (1,2-dichloro-1,1,2-trifluoroethane), 303-458 K; R134a (1,1,1,2-tetrafluoroethane), 253-373 K; and R132b (1,2-dichloro-1,1-difluoroethane), 273-398 K. Determinations of the vapor pressure were carried out by a constant-volume apparatus with an uncertainty of less than 1.0%. The vapor pressures of R123 and R123a are very similar to those of R11 over the whole experimental temperature range, but the vapor pressures of R134a and R132b differ somewhat from those of R12 and R113, respectively, as the temperature increases. The numerical vapor pressure data can be fitted bymore » an empirical equation using the Chebyshev polynomial with a mean deviation of less than 0.3%.« less

Serial Diffusion Tensor Imaging of the Optic Radiations after Acute Optic Neuritis.

PubMed

Kolbe, Scott C; van der Walt, Anneke; Butzkueven, Helmut; Klistorner, Alexander; Egan, Gary F; Kilpatrick, Trevor J

2016-01-01

Previous studies have reported diffusion tensor imaging (DTI) changes within the optic radiations of patients after optic neuritis (ON). We aimed to study optic radiation DTI changes over 12 months following acute ON and to study correlations between DTI parameters and damage to the optic nerve and primary visual cortex (V1). We measured DTI parameters [fractional anisotropy (FA), axial diffusivity (AD), radial diffusivity (RD), and mean diffusivity (MD)] from the optic radiations of 38 acute ON patients at presentation and 6 and 12 months after acute ON. In addition, we measured retinal nerve fibre layer thickness, visual evoked potential amplitude, optic radiation lesion load, and V1 thickness. At baseline, FA was reduced and RD and MD were increased compared to control. Over 12 months, FA reduced in patients at an average rate of -2.6% per annum (control = -0.51%; p = 0.006). Change in FA, RD, and MD correlated with V1 thinning over 12 months (FA: R = 0.450, p = 0.006; RD: R = -0.428, p = 0.009; MD: R = -0.365, p = 0.029). In patients with no optic radiation lesions, AD significantly correlated with RNFL thinning at 12 months (R = 0.489, p = 0.039). In conclusion, DTI can detect optic radiation changes over 12 months following acute ON that correlate with optic nerve and V1 damage.

Serial Diffusion Tensor Imaging of the Optic Radiations after Acute Optic Neuritis

PubMed Central

van der Walt, Anneke; Butzkueven, Helmut; Klistorner, Alexander; Egan, Gary F.; Kilpatrick, Trevor J.

2016-01-01

Previous studies have reported diffusion tensor imaging (DTI) changes within the optic radiations of patients after optic neuritis (ON). We aimed to study optic radiation DTI changes over 12 months following acute ON and to study correlations between DTI parameters and damage to the optic nerve and primary visual cortex (V1). We measured DTI parameters [fractional anisotropy (FA), axial diffusivity (AD), radial diffusivity (RD), and mean diffusivity (MD)] from the optic radiations of 38 acute ON patients at presentation and 6 and 12 months after acute ON. In addition, we measured retinal nerve fibre layer thickness, visual evoked potential amplitude, optic radiation lesion load, and V1 thickness. At baseline, FA was reduced and RD and MD were increased compared to control. Over 12 months, FA reduced in patients at an average rate of −2.6% per annum (control = −0.51%; p = 0.006). Change in FA, RD, and MD correlated with V1 thinning over 12 months (FA: R = 0.450, p = 0.006; RD: R = −0.428, p = 0.009; MD: R = −0.365, p = 0.029). In patients with no optic radiation lesions, AD significantly correlated with RNFL thinning at 12 months (R = 0.489, p = 0.039). In conclusion, DTI can detect optic radiation changes over 12 months following acute ON that correlate with optic nerve and V1 damage. PMID:27555964

Dynamic changes in murine forebrain miR-211 expression associate with cholinergic imbalances and epileptiform activity

PubMed Central

Mishra, Nibha; Milikovsky, Dan Z.; Hanin, Geula; Zelig, Daniel; Sheintuch, Liron; Berson, Amit; Greenberg, David S.; Friedman, Alon

2017-01-01

Epilepsy is a common neurological disease, manifested in unprovoked recurrent seizures. Epileptogenesis may develop due to genetic or pharmacological origins or following injury, but it remains unclear how the unaffected brain escapes this susceptibility to seizures. Here, we report that dynamic changes in forebrain microRNA (miR)-211 in the mouse brain shift the threshold for spontaneous and pharmacologically induced seizures alongside changes in the cholinergic pathway genes, implicating this miR in the avoidance of seizures. We identified miR-211 as a putative attenuator of cholinergic-mediated seizures by intersecting forebrain miR profiles that were Argonaute precipitated, synaptic vesicle target enriched, or differentially expressed under pilocarpine-induced seizures, and validated TGFBR2 and the nicotinic antiinflammatory acetylcholine receptor nAChRa7 as murine and human miR-211 targets, respectively. To explore the link between miR-211 and epilepsy, we engineered dTg-211 mice with doxycycline-suppressible forebrain overexpression of miR-211. These mice reacted to doxycycline exposure by spontaneous electrocorticography-documented nonconvulsive seizures, accompanied by forebrain accumulation of the convulsive seizures mediating miR-134. RNA sequencing demonstrated in doxycycline-treated dTg-211 cortices overrepresentation of synaptic activity, Ca2+ transmembrane transport, TGFBR2 signaling, and cholinergic synapse pathways. Additionally, a cholinergic dysregulated mouse model overexpressing a miR refractory acetylcholinesterase-R splice variant showed a parallel propensity for convulsions, miR-211 decreases, and miR-134 elevation. Our findings demonstrate that in mice, dynamic miR-211 decreases induce hypersynchronization and nonconvulsive and convulsive seizures, accompanied by expression changes in cholinergic and TGFBR2 pathways as well as in miR-134. Realizing the importance of miR-211 dynamics opens new venues for translational diagnosis of and interference with epilepsy. PMID:28584127

Dynamic changes in murine forebrain miR-211 expression associate with cholinergic imbalances and epileptiform activity.

PubMed

Bekenstein, Uriya; Mishra, Nibha; Milikovsky, Dan Z; Hanin, Geula; Zelig, Daniel; Sheintuch, Liron; Berson, Amit; Greenberg, David S; Friedman, Alon; Soreq, Hermona

2017-06-20

Epilepsy is a common neurological disease, manifested in unprovoked recurrent seizures. Epileptogenesis may develop due to genetic or pharmacological origins or following injury, but it remains unclear how the unaffected brain escapes this susceptibility to seizures. Here, we report that dynamic changes in forebrain microRNA (miR)-211 in the mouse brain shift the threshold for spontaneous and pharmacologically induced seizures alongside changes in the cholinergic pathway genes, implicating this miR in the avoidance of seizures. We identified miR-211 as a putative attenuator of cholinergic-mediated seizures by intersecting forebrain miR profiles that were Argonaute precipitated, synaptic vesicle target enriched, or differentially expressed under pilocarpine-induced seizures, and validated TGFBR2 and the nicotinic antiinflammatory acetylcholine receptor nAChRa7 as murine and human miR-211 targets, respectively. To explore the link between miR-211 and epilepsy, we engineered dTg-211 mice with doxycycline-suppressible forebrain overexpression of miR-211. These mice reacted to doxycycline exposure by spontaneous electrocorticography-documented nonconvulsive seizures, accompanied by forebrain accumulation of the convulsive seizures mediating miR-134. RNA sequencing demonstrated in doxycycline-treated dTg-211 cortices overrepresentation of synaptic activity, Ca 2+ transmembrane transport, TGFBR2 signaling, and cholinergic synapse pathways. Additionally, a cholinergic dysregulated mouse model overexpressing a miR refractory acetylcholinesterase-R splice variant showed a parallel propensity for convulsions, miR-211 decreases, and miR-134 elevation. Our findings demonstrate that in mice, dynamic miR-211 decreases induce hypersynchronization and nonconvulsive and convulsive seizures, accompanied by expression changes in cholinergic and TGFBR2 pathways as well as in miR-134. Realizing the importance of miR-211 dynamics opens new venues for translational diagnosis of and interference with epilepsy.

Self-reported dietary intake of omega-3 fatty acids and association with bone and lower extremity function.

PubMed

Rousseau, James H; Kleppinger, Alison; Kenny, Anne M

2009-10-01

To assess the relationship between self-reported omega-3 fatty acid (O3FA) intake and bone mineral density (BMD) and lower extremity function in older adults. Cross-sectional analysis of baseline information from three separate ongoing studies of older adults, pooled for this analysis. Academic health center. Two hundred forty-seven men (n=118) and women (n=129) residing in the community or an assisted living facility. Self-reported dietary intake (O3FA, omega-6 fatty acids (O6FA), protein, and total calorie); BMD of the hip or heel; and lower extremity function including leg strength, chair rise time, walking speed, Timed Up and Go, and frailty. The mean reported intake of O3FA was 1.27 g/day. Correlation coefficients (r) between O3FA and T-scores from total femur (n=167) were 0.210 and 0.147 for combined femur and heel T scores. Similar correlations were found for leg strength (r=0.205) and chair rise time (r=-0.178), but the significance was lost when corrected for protein intake. Subjects with lower reported O3FA intake (<1.27 g/day) had lower BMD than those with higher reported O3FA intake. In a multiple regression analysis with femoral neck BMD as the dependent variable and reported intake of O3FA, O6FA, protein, and vitamin D as independent variables, reported O3FA intake was the only significant variable, accounting for 6% of the variance in BMD. Older adults had low reported intakes of O3FA. There was an association between greater reported O3FA intake and higher BMD. There was no independent association between reported O3FA intake and lower extremity function. Results from this preliminary report are promising and suggest further investigation.

Glial activation colocalizes with structural abnormalities in amyotrophic lateral sclerosis.

PubMed

Alshikho, Mohamad J; Zürcher, Nicole R; Loggia, Marco L; Cernasov, Paul; Chonde, Daniel B; Izquierdo Garcia, David; Yasek, Julia E; Akeju, Oluwaseun; Catana, Ciprian; Rosen, Bruce R; Cudkowicz, Merit E; Hooker, Jacob M; Atassi, Nazem

2016-12-13

In this cross-sectional study, we aimed to evaluate brain structural abnormalities in relation to glial activation in the same cohort of participants. Ten individuals with amyotrophic lateral sclerosis (ALS) and 10 matched healthy controls underwent brain imaging using integrated MR/PET and the radioligand [ 11 C]-PBR28. Diagnosis history and clinical assessments including Upper Motor Neuron Burden Scale (UMNB) were obtained from patients with ALS. Diffusion tensor imaging (DTI) analyses including tract-based spatial statistics and tractography were applied. DTI metrics including fractional anisotropy (FA) and diffusivities (mean, axial, and radial) were measured in regions of interest. Cortical thickness was assessed using surface-based analysis. The locations of structural changes, measured by DTI and the areas of cortical thinning, were compared to regional glial activation measured by relative [ 11 C]-PBR28 uptake. In this cohort of individuals with ALS, reduced FA and cortical thinning colocalized with regions demonstrating higher radioligand binding. [ 11 C]-PBR28 binding in the left motor cortex was correlated with FA (r = -0.68, p < 0.05) and cortical thickness (r = -0.75, p < 0.05). UMNB was correlated with glial activation (r = +0.75, p < 0.05), FA (r = -0.77, p < 0.05), and cortical thickness (r = -0.75, p < 0.05) in the motor cortex. Increased uptake of the glial marker [ 11 C]-PBR28 colocalizes with changes in FA and cortical thinning. This suggests a link between disease mechanisms (gliosis and inflammation) and structural changes (cortical thinning and white and gray matter changes). In this multimodal neuroimaging work, we provide an in vivo model to investigate the pathogenesis of ALS. © 2016 American Academy of Neurology.

Glial activation colocalizes with structural abnormalities in amyotrophic lateral sclerosis

PubMed Central

Alshikho, Mohamad J.; Zürcher, Nicole R.; Loggia, Marco L.; Cernasov, Paul; Chonde, Daniel B.; Izquierdo Garcia, David; Yasek, Julia E.; Akeju, Oluwaseun; Catana, Ciprian; Rosen, Bruce R.; Cudkowicz, Merit E.

2016-01-01

Objective: In this cross-sectional study, we aimed to evaluate brain structural abnormalities in relation to glial activation in the same cohort of participants. Methods: Ten individuals with amyotrophic lateral sclerosis (ALS) and 10 matched healthy controls underwent brain imaging using integrated MR/PET and the radioligand [11C]-PBR28. Diagnosis history and clinical assessments including Upper Motor Neuron Burden Scale (UMNB) were obtained from patients with ALS. Diffusion tensor imaging (DTI) analyses including tract-based spatial statistics and tractography were applied. DTI metrics including fractional anisotropy (FA) and diffusivities (mean, axial, and radial) were measured in regions of interest. Cortical thickness was assessed using surface-based analysis. The locations of structural changes, measured by DTI and the areas of cortical thinning, were compared to regional glial activation measured by relative [11C]-PBR28 uptake. Results: In this cohort of individuals with ALS, reduced FA and cortical thinning colocalized with regions demonstrating higher radioligand binding. [11C]-PBR28 binding in the left motor cortex was correlated with FA (r = −0.68, p < 0.05) and cortical thickness (r = −0.75, p < 0.05). UMNB was correlated with glial activation (r = +0.75, p < 0.05), FA (r = −0.77, p < 0.05), and cortical thickness (r = −0.75, p < 0.05) in the motor cortex. Conclusions: Increased uptake of the glial marker [11C]-PBR28 colocalizes with changes in FA and cortical thinning. This suggests a link between disease mechanisms (gliosis and inflammation) and structural changes (cortical thinning and white and gray matter changes). In this multimodal neuroimaging work, we provide an in vivo model to investigate the pathogenesis of ALS. PMID:27837005

White matter organization in cervical spinal cord relates differently to age and control of grip force in healthy subjects.

PubMed

Lindberg, Påvel G; Feydy, Antoine; Maier, Marc A

2010-03-17

Diffusion tensor imaging (DTI) can be used to elucidate relations between CNS structure and function. We hypothesized that the degree of spinal white matter organization relates to the accuracy of control of grip force. Healthy subjects of different age were studied using DTI and visuomotor tracking of precision grip force. The latter is a prime component of manual dexterity. A regional analysis of spinal white matter [fractional anisotropy (FA)] across multiple cervical levels (C2-C3, C4-C5, and C6-C7) and in different regions of interest (left and right lateral or medial spinal cord) was performed. FA was highest at the C2-C3 level, higher on the right than the left side, and higher in the lateral than in the medial spinal cord (p < 0.001). FA of whole cervical spinal cord (C2-C7) was lower in subjects with high tracking error (r = -0.56, p = 0.004) and decreased with age (r = -0.63, p = 0.001). A multiple regression analysis revealed an independent contribution of each predictor (semipartial correlations: age, r = -0.55, p < 0.001; tracking error, r = -0.49, p = 0.003). The closest relation between FA and tracking error was found at the C6-C7 level in the lateral spinal cord, in which the corticospinal tract innervates spinal circuitry controlling hand and digit muscles. FA of the medial spinal cord correlated consistently with age across all cervical levels, whereas FA of the lateral spinal cord did not. The results suggest (1) a functionally relevant specialization of lateral spinal cord white matter and (2) an increased sensitivity to age-related decline in medial spinal cord white matter in healthy subjects.

Commissioning and Operational Experience with 1 kW Class Helium Refrigerator/Liquefier for SST-1

NASA Astrophysics Data System (ADS)

Dhard, C. P.; Sarkar, B.; Misra, Ruchi; Sahu, A. K.; Tanna, V. L.; Tank, J.; Panchal, P.; Patel, J. C.; Phadke, G. D.; Saxena, Y. C.

2004-06-01

The helium refrigerator/liquefier (R/L) for the Steady State Super conducting Tokamak (SST-1) has been developed with very stringent specifications for the different operational modes. The total refrigeration capacity is 650 W at 4.5 K and liquefaction capacity of 200 l/h. A cold circulation pump is used for the forced flow cooling of 300 g/s supercritical helium (SHe) for the magnet system (SCMS). The R/L has been designed also to absorb a 200 W transient heat load of the SCMS. The plant consists of a compressor station, oil removal system, on-line purifier, Main Control Dewar (MCD) with associated heat exchangers, cold circulation pump and warm gas management system. An Integrated Flow Control and Distribution System (IFDCS) has been designed, fabricated and installed for distribution of SHe in the toroidal and poloidal field coils as well as liquid helium for cooling of 10 pairs of current leads. A SCADA based control system has been designed using PLC for R/L as well as IFDCS. The R/L has been commissioned and required parameters were achieved confirming to the process. All the test results and commissioning experiences are discussed in this paper.

Short- and long-term releases of fluorocarbons from disposal of polyurethane foam waste.

PubMed

Kjeldsen, Peter; Scheutz, Charlotte

2003-11-01

Several halocarbons having very high global warming or ozone depletion potentials have been used as a blowing agent (BA) for insulation foam in home appliances, such as refrigerators and freezers. Many appliances are shredded after the end of their useful life. Release experiments carried out in the laboratory on insulation foam blown with the blowing agents CFC-11, HCFC-141b, HCF-134fa, and HFC-245fa revealed that not all blowing agents are released during a 6-week period following the shredding process. The experiments confirmed the hypothesis that the release could be divided into three segments: By shredding foam panels, a proportion of the closed cells is either split or damaged to a degree allowing for a sudden release of the contained atmosphere in the cell (the instantaneous release). Cells adjacent to the cut surface may be only slightly damaged by tiny cracks or holes allowing a relative slow release of the BA to the surroundings (the short-term release). A significant portion of the cells in the foam particle will be unaffected and only allows release governed by slow diffusion through the PUR cell wall (the long-term release). The magnitude of the releases is for all three types highly dependent on how fine the foam is shredded. The residual blowing agent remaining after the 6-week period may be very slowly released if the integrity of the foam particles with respect to diffusion properties is kept after disposal of the foam waste on landfills. It is shown by setting up a national model simulating the BA releases following decommissioning of used domestic refrigerators/freezers in the United States that the release patterns are highly dependent on how the appliances are shredded.

REMPI and MATI spectroscopy of cis and trans 4-chloro-3-fluoroanisole

NASA Astrophysics Data System (ADS)

Liu, Sheng; Dai, Wenshuai; Lin, Dan; Cheng, Min; Du, YiKui; Zhu, Qihe

2017-08-01

The Resonance-enhanced two-photon ionization (R2PI) and Mass-analyzed threshold ionization (MATI) spectra of 4-chloro-3-fluoroanisole (4Cl3FA) were recorded in detail. The experimental and calculated results revealed that cis and trans 4Cl3FA are the only two stable conformers in each of the S0, S1 and D0 states. The first electronic excitation energies (E1's) of cis and trans35Cl-4Cl3FA were measured to be 35,326 ± 3 and 35,443 ± 3 cm-1 by the R2PI spectroscopy and the corresponding adiabatic ionization energies (IEs) were determined to be 67,330 ± 5 and 67,591 ± 5 cm-1 by the MATI spectroscopy. The E1's and IEs of cis and trans37Cl-4Cl3FA were also obtained and found to be identical to that of the 35Cl-4Cl3FA conformers. Compared with the trans 4Cl3FA, the cis 4Cl3FA is more stable in the S0, S1 and D0 states. The vibrational bands observed in the R2PI and MATI spectra are related to the vibrations involving the in-plane deformation of the benzene ring, the CH3 torsion and the OCH3 inversion. The substituent effects on the molecular structures, transition energies and vibrations of 4Cl3FA are discussed.

Global emissions of refrigerants HCFC-22 and HFC-134a: Unforeseen seasonal contributions

PubMed Central

Xiang, Bin; Montzka, Stephen A.; Miller, Scot M.; Elkins, James W.; Moore, Fred L.; Atlas, Elliot L.; Miller, Ben R.; Weiss, Ray F.; Prinn, Ronald G.; Wofsy, Steven C.

2014-01-01

HCFC-22 (CHClF2) and HFC-134a (CH2FCF3) are two major gases currently used worldwide in domestic and commercial refrigeration and air conditioning. HCFC-22 contributes to stratospheric ozone depletion, and both species are potent greenhouse gases. In this work, we study in situ observations of HCFC-22 and HFC-134a taken from research aircraft over the Pacific Ocean in a 3-y span [HIaper-Pole-to-Pole Observations (HIPPO) 2009–2011] and combine these data with long-term ground observations from global surface sites [National Oceanic and Atmospheric Administration (NOAA) and Advanced Global Atmospheric Gases Experiment (AGAGE) networks]. We find the global annual emissions of HCFC-22 and HFC-134a have increased substantially over the past two decades. Emissions of HFC-134a are consistently higher compared with the United Nations Framework Convention on Climate Change (UNFCCC) inventory since 2000, by 60% more in recent years (2009–2012). Apart from these decadal emission constraints, we also quantify recent seasonal emission patterns showing that summertime emissions of HCFC-22 and HFC-134a are two to three times higher than wintertime emissions. This unforeseen large seasonal variation indicates that unaccounted mechanisms controlling refrigerant gas emissions are missing in the existing inventory estimates. Possible mechanisms enhancing refrigerant losses in summer are (i) higher vapor pressure in the sealed compartment of the system at summer high temperatures and (ii) more frequent use and service of refrigerators and air conditioners in summer months. Our results suggest that engineering (e.g., better temperature/vibration-resistant system sealing and new system design of more compact/efficient components) and regulatory (e.g., reinforcing system service regulations) steps to improve containment of these gases from working devices could effectively reduce their release to the atmosphere. PMID:25422438

Ferulic Acid, But Not All Hydroxycinnamic Acids, Is a Novel T3SS Inducer of Ralstonia solanacearum and Promotes Its Infection Process in Host Plants under Hydroponic Condition.

PubMed

Zhang, Yong; Li, Jing; Zhang, Weiqi; Wang, Rongsheng; Qiu, Qiaoqing; Luo, Feng; Hikichi, Yasufumi; Ohnishi, Kouhei; Ding, Wei

2017-01-01

Hydroxycinnamic acids (HCAs) are typical monocyclic phenylpropanoids, including cinnamic acid (Cin), coumaric acid (Cou), caffeic acid (Caf), ferulic acid (FA) and their isomers, and involved in the interactions between pathogens and host plants. Here, we focused on the impact of HCAs on expression of type III secretion system (T3SS) in Ralstonia solanacearum . FA significantly induced the expression of the T3SS and some type III effectors (T3Es) genes in hrp -inducing medium, while did not the other HCAs. However, exogenously supplemented FA did not affect the T3SS expression in planta and the elicitation of the hypersensitive response (HR) in tobacco leaves. Consistent with its central roles in pathogenicity, the FA-induced expression of the T3SS led to significant promotion on infection process of R. solanacearum in tomato plants under hydroponics cultivation. Moreover, the FA-induced expression of the T3SS was specifically mediated by the well-characterized signaling cascade PrhA-prhI/R-PrhJ-HrpG-HrpB, independent of the other known regulatory pathways. In summary, our results demonstrated that FA, a novel inducer of the T3SS in R. solanacearum , was able to promote its infection process in host plants under hydroponics condition.

Regulation of palmitoyl-CoA chain elongation by clofibric acid in the liver of Zucker fa/fa rats.

PubMed

Toyama, Tomoaki; Kudo, Naomi; Mitsumoto, Atsushi; Kawashima, Yoichi

2005-05-01

The regulation of palmitoyl-CoA chain elongation (PCE) by clofibric acid [2-(4-chlorophenoxy)-2-methylpropionic acid] was investigated in comparison with stearoyl-CoA desaturase (SCD) in the liver of obese Zucker fa/fa rats. The proportion of oleic acid in the hepatic lipids of Zucker obese rats is 2.7 times higher than that of lean littermates. The activities of PCE and SCD in the liver of Zucker obese rats were markedly higher than in lean rats, and the hepatic uptake of 2-deoxyglucose (2-DG) was also higher in Zucker obese rats compared with lean rats. The increased activities of SCD and PCE in Zucker obese rats were due to the enhanced expression of mRNA of both SCD1 and rat FA elongase 2 (rELO2), but not SCD2 or rELO1. The proportion of oleic acid in the liver was significantly increased by the administration of clofibric acid to Zucker obese rats, and the hepatic PCE activity and rELO2 mRNA expression, but not the SCD activity or SCD1 mRNA expression, were increased in response to clofibric acid treatment. By contrast, the activities of both PCE and SCD and the mRNA expression of SCD1 and rELO2 in the liver were increased by the treatment of Zucker lean rats with clofibric acid. Multiple regression analysis, which was performed to determine the relationships involving PCE activity, SCD activity, and the proportion of oleic acid, revealed that the three parameters were significantly correlated and that the standardized partial regression coefficient of PCE was higher than that of SCD. These results indicate that oleic acid is synthesized by the concerted action of PCE and SCD and that PCE plays a crucial role in the formation of oleic acid when Zucker fa/fa rats are given clofibric acid.

40 CFR 82.36 - Approved refrigerant handling equipment.

Code of Federal Regulations, 2011 CFR

2011-07-01

... Approved refrigerant handling equipment. (a)(1) Refrigerant recycling equipment must be certified by the...) Recovery/Recycling Equipment and Recovery/Recycling/Recharging for Mobile Air-Conditioning Systems. (5... Recycling Equipment Intended for Use with both CFC-12 and HFC-134a, Recommended Service Procedure for the...

40 CFR 82.36 - Approved refrigerant handling equipment.

Code of Federal Regulations, 2013 CFR

2013-07-01

... Approved refrigerant handling equipment. (a)(1) Refrigerant recycling equipment must be certified by the...) Recovery/Recycling Equipment and Recovery/Recycling/Recharging for Mobile Air-Conditioning Systems. (5... Recycling Equipment Intended for Use with both CFC-12 and HFC-134a, Recommended Service Procedure for the...

40 CFR 82.36 - Approved refrigerant handling equipment.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Approved refrigerant handling equipment. (a)(1) Refrigerant recycling equipment must be certified by the...) Recovery/Recycling Equipment and Recovery/Recycling/Recharging for Mobile Air-Conditioning Systems. (5... Recycling Equipment Intended for Use with both CFC-12 and HFC-134a, Recommended Service Procedure for the...

40 CFR 82.36 - Approved refrigerant handling equipment.

Code of Federal Regulations, 2014 CFR

2014-07-01

... Approved refrigerant handling equipment. (a)(1) Refrigerant recycling equipment must be certified by the...) Recovery/Recycling Equipment and Recovery/Recycling/Recharging for Mobile Air-Conditioning Systems. (5... Recycling Equipment Intended for Use with both CFC-12 and HFC-134a, Recommended Service Procedure for the...

40 CFR 82.36 - Approved refrigerant handling equipment.

Code of Federal Regulations, 2012 CFR

2012-07-01

... Approved refrigerant handling equipment. (a)(1) Refrigerant recycling equipment must be certified by the...) Recovery/Recycling Equipment and Recovery/Recycling/Recharging for Mobile Air-Conditioning Systems. (5... Recycling Equipment Intended for Use with both CFC-12 and HFC-134a, Recommended Service Procedure for the...

Surveillance of Strontium-90 in Foods after the Fukushima Daiichi Nuclear Power Plant Accident.

PubMed

Nabeshi, Hiromi; Tsutsumi, Tomoaki; Uekusa, Yoshinori; Hachisuka, Akiko; Matsuda, Rieko; Teshima, Reiko

2015-01-01

As a result of the Fukushima Daiichi nuclear power plant (NPP) accident, various radionuclides were released into the environment. In this study, we surveyed strontium-90 ((90)Sr) concentrations in several foodstuffs. Strontium-90 is thought to be the third most important residual radionuclide in food collected after the Fukushima Daiichi, NPP accident after following cesium-137 ((137)Cs) and cesium-134 ((134)Cs). Results of (90)Sr analyses indicated that (90)Sr was detect in 25 of the 40 radioactive cesium (r-Cs) positive samples collected in areas around the Fukushima Daiichi NPP, ranging in distance from 50 to 250 km. R-Cs positive samples were defined as containing both (134)Cs and (137)Cs which are considered to be indicators of the after-effects of the Fukushima Daiichi NPP accident. We also detected (90)Sr in 8 of 13 r-Cs negative samples, in which (134)Cs was not detected. Strontium-90 concentrations in the r-Cs positive samples did not significantly exceed the (90)Sr concentrations in r-Cs negative samples or the (90)Sr concentration ranges in comparable food groups found in previous surveys before the Fukushima Daiichi NPP accident. Thus, (90)Sr concentrations in r-Cs positive samples were indistinguishable from the background (90)Sr concentrations arising from global fallout prior to the Fukushima accident, suggesting that no marked increase of (90)Sr concentrations has occurred in r-Cs positive samples as a result of the Fukushima Daiichi NPP accident.

INVESTIGATION OF AMMONIA EQUIPMENT CONFIGURATIONS FOR SUPERMARKET APPLICATIONS

EPA Science Inventory

The report gives results of a project to quantify the advantages and disadvantages of using ammonia with a secondary brine refrigerant compared to R-22 in supermarket refrigeration applications. roject objectives were achieved by numerical experiments using simulations. echanisti...

White matter properties differ in 6-year old Readers and Pre-Readers

PubMed Central

Kovachy, Vanessa N; Ben-Shachar, Michal; Feldman, Heidi M

2016-01-01

Reading, an essential life skill in modern society, is typically learned during childhood. Adults who can read show white matter differences compared to adults who never learned to read. Studies have not established whether children who can read show similar white matter differences compared to children who cannot read. We compared 6-year old children who could decode written English words and pseudowords (n=31; Readers) and 6-year old children who could not decode pseudowords and had a standard score < 100 on a task for reading single words (n=11; Pre-Readers). We employed diffusion MRI and tractography to extract fractional anisotropy (FA) along the trajectory of 6 bilateral intra-hemispheric tracts and 2 posterior subdivisions of the corpus callosum. Readers demonstrated significantly increased FA within the left anterior segment of the superior longitudinal fasciculus (aSLF-L) and the right uncinate fasciculus (UF-R) compared to Pre-Readers. FA in the aSLF-L was significantly correlated with phonological awareness; FA in the UF-R was significantly correlated with language. Correlations in the UF-R but not the aSLF-L remained significant after controlling for reading ability, revealing that UF-R group differences were related to both children's language and reading abilities. Taken together, these findings demonstrate new evidence showing that individual differences in white matter structure relate to whether children have begun to read. PMID:27631434

A narrative synthesis of the applicability of the CaR-FA-X model in child and adolescent populations: a systematic review.

PubMed

Stewart, Tracy M; Hunter, Simon C; Rhodes, Sinéad M

2017-10-01

The CaR-FA-X model [Williams, J. M. G., Barnhofer, T., Crane, C., Hermans, D., Raes, F., Watkins, E., … Dalgleish, T. (2007). Autobiographical memory specificity and emotional disorder. Psychological Bulletin, 133(1), 122-148. doi: 10.1037/0033-2909.133.1.122 ] is the most prominent and comprehensive model of overgeneral autobiographical memory (OGM) and provides a framework for OGM. The model comprises of three mechanisms, capture and rumination, functional avoidance and impaired executive control. These can independently, or in interaction, account for OGM. This systematic review aims to evaluate the existing research on the CaR-FA-X model, and trauma exposure studies specific to child and adolescent populations. The following databases were searched: "PsychInfo", "PsychArticles", "PubMed", "Web of Science", "Medline", "SCOPUS" and "Embase" for English-language, peer-reviewed papers with samples

Role of the Conserved Valine 236 in Access of Ligands to the Active Site of Thermus thermophilus ba3 Cytochrome Oxidase.

PubMed

Funatogawa, Chie; Li, Yang; Chen, Ying; McDonald, William; Szundi, Istvan; Fee, James A; Stout, C David; Einarsdóttir, Ólöf

2017-01-10

Knowledge of the role of conserved residues in the ligand channel of heme-copper oxidases is critical for understanding how the protein scaffold modulates the function of these enzymes. In this study, we investigated the role of the conserved valine 236 in the ligand channel of ba 3 cytochrome c oxidase from Thermus thermophilus by mutating the residue to a more polar (V236T), smaller (V236A), or larger (V236I, V236N, V236L, V236M, and V236F) residue. The crystal structures of the mutants were determined, and the effects of the mutations on the rates of CO, O 2 , and NO binding were investigated. O 2 reduction and NO binding were unaffected in V236T, while the oxidation of heme b during O-O bond cleavage was not detected in V236A. The V236A results are attributed to a decrease in the rate of electron transfer between heme b and heme a 3 during O-O bond cleavage in V236A, followed by faster re-reduction of heme b by Cu A . This interpretation is supported by classical molecular dynamics simulations of diffusion of O 2 to the active site in V236A that indicated a larger distance between the two hemes compared to that in the wild type and increased contact of heme a 3 with water and weakened interactions with residues R444 and R445. As the size of the mutant side chain increased and protruded more into the ligand cavity, the rates of ligand binding decreased correspondingly. These results demonstrate the importance of V236 in facilitating access of ligands to the active site in T. thermophilus ba 3 .

Folic acid supplementation does not reduce intracellular homocysteine, and may disturb intracellular one-carbon metabolism.

PubMed

Smith, Desirée E C; Hornstra, Jacqueline M; Kok, Robert M; Blom, Henk J; Smulders, Yvo M

2013-08-01

In randomized trails, folic acid (FA) lowered plasma homocysteine, but failed to reduce cardiovascular risk. We hypothesize this is due to a discrepancy between plasma and intracellular effects of FA. In a double-blind trial, 50 volunteers were randomized to received 500 µg FA daily for 8 weeks, or placebo. Plasma and peripheral blood mononuclear cell (PBMC) concentrations of homocysteine, S-adenosylmethionine (SAM), S-adenosylhomocysteine, methionine, cystathionine and 5-methyltetrahydrofolate (bioactive folate) were measured by liquid chromatography-tandem mass spectrometry (LC-MS/MS). PBMCs were used as a cellular model since they display the full spectrum of one-carbon (1C) enzymes and reactions. At baseline, plasma concentrations were a poor reflection of intracellular concentrations for most 1C metabolites, except 5-methyltetrahydrofolate (R=0.33, p=0.02), homocysteine (Hcy) (R=0.35, p=0.01), and cystathionine (R=0.45, p=0.001). FA significantly lowered plasma homocysteine (p=0.00), but failed to lower intracellular homocysteine or change the concentrations of any of the other PBMC 1C metabolites. At baseline, PBMC homocysteine concentrations correlated to PBMC SAM. After FA supplementation, PBMC homocysteine no longer correlated with PBMC SAM, suggesting a loss of SAM's regulatory function. In vitro experiments in lymphoblasts confirmed that at higher folate substrate concentrations, physiological concentrations of SAM no longer effectively inhibit the key regulatory enzyme methylenetetrahydrofolate reductase (MTHFR). FA supplementation does not reduce intracellular concentrations of Hcy or any of its closely related substances. Rather, FA may disturb physiological regulation of intracellular 1C metabolism by interfering with SAM's inhibitory effect on MTHFR activity.

NEW CHEMICAL ALTERNATIVE FOR OZONE-DEPLETING SUBSTANCES: HFC-236EA

EPA Science Inventory

The report gives results of a preliminary evaluation of a new hydrofluorocarbon (HFC-236ea or 1, 1, 1, 2, 3, 3-hexafluoropropane) as a possible alternative for chlorofluorocarbon (CFC)-114 (1, 2-dichloro-1, 1, 2, 2-tetrafluoroethane) refrigerant in chillers and high-temperature i...

Design and experimental investigation of an ejector in an air-conditioning and refrigeration system

DOE Office of Scientific and Technical Information (OSTI.GOV)

AL-Khalidy, N.; Zayonia, A.

1995-12-31

This paper discusses the conservation of energy in a refrigerant ejector refrigerating machine using heat driven from the concentrator collectors. The working refrigerant was R-113. The design of an ejector operating in an air-conditioning and refrigerating system with a low thermal source (70 C to 100 C) is presented. The influence of three major parameters--boiler, condenser, and evaporator temperature--on ejector efficiency is discussed. Experimental results show that the condenser temperature is the major influence at a low evaporator temperature. The maximum ejector efficiency was 31%.

In-Situ Approach to Introduce Flux Pinning in YBCO (Postprint)

DTIC Science & Technology

2012-02-01

Malozemoff, N. Nguyen, E. Siegal, D. Buczek, J. Lynch, J. Scudiere, M. Rupich, A. Goyal, E.D. Specht , P. Martin, and M. Paranthaman, Supercond. Sci...Peterson, L. Stan, and L.A. Emmert, Physica C. 382,43-47 (2002). [10] A. Goyal, D.F. Lee, F.A. List, E.D. Specht , R. Feenstra, M. Paranthaman, X. Cui, S.W...Gapud, M. Varela, M. Paranthaman, A. 0. Ijaduola, E.D. Specht , J.R. Thompson, O.K. Christen, S.J. Pennycook, and F.A. List, Supercond. Sci. Techno

Estimation of the R134a gas refractive index for use as a Cherenkov radiator, using a high energy charged particle beam

NASA Astrophysics Data System (ADS)

Charitonidis, N.; Karyotakis, Y.; Gatignon, L.

2017-11-01

Gases with relatively high refractive index, n - 1 ≥ 500 ×10-6 at atmospheric pressure, giving a satisfactory photoelectron yield at relatively low pressures (≤ 5 bar) are rare. These gases are often the only practical solution for low momentum particle identification in conventional secondary beam lines. The refractive index of R134a, one of the most common gases available to the physics community, has never been measured or reported. In the present note, the results of a dedicated experiment to estimate the refractive index of R134a, using mixed hadron/electron beams in the range 0.5-10 GeV are presented.

The Equivalent Static Accelerations of Shock Motions

DTIC Science & Technology

1948-06-21

BLOW 3 HACK -.,. .:■-■ 5" PACK BL 0 » .r .a ^r .’.«.«.« -a TrMr Ih’fflVJiL BETWEEN TPACF IN’EHh Fig. 12...I • • • • fa « --^ o <« is >• 8 Sa 3 I! o • n Is i ä «H « <" 0 tJ u _ a> l-’S- bO ^ 2 c S3 5 | J5 I c a> 6 v fa 3

Regional pulse wave velocities and their cardiovascular risk factors among healthy middle-aged men: a cross-sectional population-based study.

PubMed

Choo, Jina; Shin, Chol; Barinas-Mitchell, Emma; Masaki, Kamal; Willcox, Bradley J; Seto, Todd B; Ueshima, Hirotsugu; Lee, Sunghee; Miura, Katsuyuki; Venkitachalam, Lakshmi; Mackey, Rachel H; Evans, Rhobert W; Kuller, Lewis H; Sutton-Tyrrell, Kim; Sekikawa, Akira

2014-01-13

Both carotid-femoral (cf) pulse wave velocity (PWV) and brachial-ankle (ba) PWV employ arterial sites that are not consistent with the path of blood flow. Few previous studies have reported the differential characteristics between cfPWV and baPWV by simultaneously comparing these with measures of pure central (aorta) and peripheral (leg) arterial stiffness, i.e., heart-femoral (hf) PWV and femoral-ankle (fa) PWV in healthy populations. We aimed to identify the degree to which these commonly used measures of cfPWV and baPWV correlate with hfPWV and faPWV, respectively, and to evaluate whether both cfPWV and baPWV are consistent with either hfPWV or faPWV in their associations with cardiovascular (CV) risk factors. A population-based sample of healthy 784 men aged 40-49 (202 white Americans, 68 African Americans, 202 Japanese-Americans, and 282 Koreans) was examined in this cross-sectional study. Four regional PWVs were simultaneously measured by an automated tonometry/plethysmography system. cfPWV correlated strongly with hfPWV (r = .81, P < .001), but weakly with faPWV (r = .12, P = .001). baPWV correlated moderately with both hfPWV (r = .47, P < .001) and faPWV (r = .62, P < .001). After stepwise regression analyses with adjustments for race, cfPWV shared common significant correlates with both hfPWV and faPWV: systolic blood pressure (BP) and body mass index (BMI). However, BMI was positively associated with hfPWV and cfPWV, and negatively associated with faPWV. baPWV shared common significant correlates with hfPWV: age and systolic BP. baPWV also shared the following correlates with faPWV: systolic BP, triglycerides, and current smoking. Among healthy men aged 40 - 49, cfPWV correlated strongly with central PWV, and baPWV correlated with both central and peripheral PWVs. Of the CV risk factors, systolic BP was uniformly associated with all the regional PWVs. In the associations with factors other than systolic BP, cfPWV was consistent with central PWV, while baPWV was consistent with both central and peripheral PWVs.

Total environmental warming impact (TEWI) calculations for alternative automative air-conditioning systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sand, J.R.; Fischer, S.K.

1997-01-01

The Montreal Protocol phase-out of chlorofluorocarbons (CFCs) has required manufacturers to develop refrigeration and air-conditioning systems that use refrigerants that can not damage stratospheric ozone. Most refrigeration industries have adapted their designs to use hydrochlorofluorocarbon (HCFC) or hydrofluorocarbon (HFC) refrigerants; new automobile air- conditioning systems use HFC-134a. These industries are now being affected by scientific investigations of greenhouse warming and questions about the effects of refrigerants on global warming. Automobile air-conditioning has three separate impacts on global warming; (1) the effects of refrigerant inadvertently released to the atmosphere from accidents, servicing, and leakage; (2) the efficiency of the cooling equipmentmore » (due to the emission of C0{sub 2} from burning fuel to power the system); and (3) the emission of C0{sub 2} from burning fuel to transport the system. The Total Equivalent Warming Impact (TEWI) is an index that should be used to compare the global warming effects of alternative air-conditioning systems because it includes these contributions from the refrigerant, cooling efficiency, and weight. This paper compares the TEWI of current air-conditioning systems using HFC-134a with that of transcritical vapor compression system using carbon dioxide and systems using flammable refrigerants with secondary heat transfer loops. Results are found to depend on both climate and projected efficiency of C0{sub 2}systems. Performance data on manufacturing prototype systems are needed to verify the potential reductions in TEWI. Extensive field testing is also required to determine the performance, reliability, and ``serviceability`` of each alternative to HFC-134a to establish whether the potential reduction of TEWI can be achieved in a viable consumer product.« less

HEAT TRANSFER EVALUATION OF HFC-236EA AND CFC-114 IN CONDENSATION AND EVAPORATION

EPA Science Inventory

The report gives results of a heat transfer evaluation of the refrigerants hexafluoropropane (HFC-236ea) and 1,1,2,2-dichloro-tetrafluoroethane (CFC-114). (NOTE: With the mandatory phase-out of chlorofluorocarbons (CFCs), as dictated by the Montreal Protocol and Clean Air Act Ame...

Performance analysis of low temperature heat source of organic Rankine cycle for geothermal application

NASA Astrophysics Data System (ADS)

Pintoro, A.; Ambarita, H.; Nur, T. B.; Napitupulu, F. H.

2018-02-01

Indonesia has a high potential energy resources from geothermal activities. Base on the report of Asian Development Bank and World Bank, the estimated of Indonesian hydrothermal geothermal resource considered to be the largest among the world. If it’s can be utilized to produce the electric power, it’s can contribute to increasing the electrification rates in Indonesia. In this study, an experimental studied of electric power generation, utilizing the Organic Rankine Cycle (ORC) system to convert the low level heat of hydrothermal as an energy source. The temperature of hydrothermal was modelled as hot water from water boiler which has a temperature range from 60 °C - 100 °C to heat up the organic working fluid of ORC system. The system can generated 1,337.7 watts of electricity when operated using R134A with hot water inlet temperature of 100 °C. Changing system working fluid to R245fa, the net power obtained increase to 1,908.9 watts with the same heat source condition. This study showed that the ORC system can be implemented to utilize low temperature heat source of hydrothermal in Indonesia.

Staff - Janet R. Schaefer | Alaska Division of Geological & Geophysical

Science.gov Websites

. http://doi.org/10.14509/25602 Wallace, K.L., Schaefer, J.R., and Coombs, M.L., 2013, Character, mass ., Coombs, M.L., Diefenbach, A.K., Lopez, Taryn, McNutt, S.R., Neal, C.A., Payne, A.L., Power, J.A , J.E., Schilling, S.P., Schaefer, J.R., and Trusdell, F.A., 2007, Crisis GIS: Preparing for and

Pharmacodynamics of folic acid receptor targeted antiretroviral nanotherapy in HIV-1-infected humanized mice.

PubMed

Puligujja, Pavan; Araínga, Mariluz; Dash, Prasanta; Palandri, Diana; Mosley, R Lee; Gorantla, Santhi; Poluektova, Larisa; McMillan, JoEllyn; Gendelman, Howard E

2015-08-01

Long-acting nanoformulated antiretroviral therapy (nanoART) can sustain plasma drug levels and improve its biodistribution. Cell targeted-nanoART can achieve this and bring drug efficiently to viral reservoirs. However, whether such improvements affect antiretroviral responses remains unknown. To these ends, we tested folic acid (FA)-linked poloxamer407-coated ritonavir-boosted atazanavir (FA-nanoATV/r) nanoparticles for their ability to affect chronic HIV-1 infection in humanized mice. Following three, 100mg/kg FA-nanoATV/r intramuscular injections administered every other week to infected animals, viral RNA was at or below the detection limit, cell-associated HIV-1p24 reduced and CD4+ T cell counts protected. The dosing regimen improved treatment outcomes more than two fold from untargeted nanoATV/r. We posit that these nanoformulations have potential for translation to human use. Copyright © 2015 Elsevier B.V. All rights reserved.

Subconcussive Head Impact Exposure and White Matter Tract Changes over a Single Season of Youth Football

PubMed Central

Bahrami, Naeim; Sharma, Dev; Rosenthal, Scott; Davenport, Elizabeth M.; Urban, Jillian E.; Wagner, Benjamin; Jung, Youngkyoo; Vaughan, Christopher G.; Gioia, Gerard A.; Stitzel, Joel D.; Maldjian, Joseph A.

2016-01-01

Purpose To examine the effects of subconcussive impacts resulting from a single season of youth (age range, 8–13 years) football on changes in specific white matter (WM) tracts as detected with diffusion-tensor imaging in the absence of clinically diagnosed concussions. Materials and Methods Head impact data were recorded by using the Head Impact Telemetry system and quantified as the combined-probability risk-weighted cumulative exposure (RWECP). Twenty-five male participants were evaluated for seasonal fractional anisotropy (FA) changes in specific WM tracts: the inferior fronto-occipital fasciculus (IFOF), inferior longitudinal fasciculus, and superior longitudinal fasciculus (SLF). Fiber tracts were segmented into a central core and two fiber terminals. The relationship between seasonal FA change in the whole fiber, central core, and the fiber terminals with RWECP was also investigated. Linear regression analysis was conducted to determine the association between RWECP and change in fiber tract FA during the season. Results There were statistically significant linear relationships between RWEcp and decreased FA in the whole (R2 = 0.433; P = .003), core (R2 = 0.3649; P = .007), and terminals (R2 = 0.5666; P < .001) of left IFOF. A trend toward statistical significance (P = .08) in right SLF was observed. A statistically significant correlation between decrease in FA of the right SLF terminal and RWECP was also observed (R2 = 0.2893; P = .028). Conclusion This study found a statistically significant relationship between head impact exposure and change of FAfractional anisotropy value of whole, core, and terminals of left IFOF and right SLF’s terminals where WM and gray matter intersect, in the absence of a clinically diagnosed concussion. © RSNA, 2016 PMID:27775478

TRANSPORT PROPERTY MEASUREMENTS OF HFC-236EA

EPA Science Inventory

The report gives results of an evaluation of transport properties of 1,1,1,2,3,3,-hexafluoropropane (HFC-236ea), with liquid viscosity and thermal conductivity being the two main transport properties of interest. In addition, the specific heat and density of refrigerant/lubrican...

40 CFR Appendix E to Subpart B of... - The Standard for Automotive Refrigerant Recycling Equipment Intended for Use With Both CFC-12 and...

Code of Federal Regulations, 2014 CFR

2014-07-01

... Refrigerant Recycling Equipment Intended for Use With Both CFC-12 and HFC-134a E Appendix E to Subpart B of... Appendix E to Subpart B of Part 82—The Standard for Automotive Refrigerant Recycling Equipment Intended for... specific minimum equipment requirements for automotive refrigerant recycling equipment intended for use...

40 CFR Appendix E to Subpart B of... - The Standard for Automotive Refrigerant Recycling Equipment Intended for Use With Both CFC-12 and...

Code of Federal Regulations, 2012 CFR

2012-07-01

... Refrigerant Recycling Equipment Intended for Use With Both CFC-12 and HFC-134a E Appendix E to Subpart B of... Appendix E to Subpart B of Part 82—The Standard for Automotive Refrigerant Recycling Equipment Intended for... specific minimum equipment requirements for automotive refrigerant recycling equipment intended for use...

40 CFR Appendix E to Subpart B of... - The Standard for Automotive Refrigerant Recycling Equipment Intended for Use With Both CFC-12 and...

Code of Federal Regulations, 2013 CFR

2013-07-01

... Refrigerant Recycling Equipment Intended for Use With Both CFC-12 and HFC-134a E Appendix E to Subpart B of... Appendix E to Subpart B of Part 82—The Standard for Automotive Refrigerant Recycling Equipment Intended for... specific minimum equipment requirements for automotive refrigerant recycling equipment intended for use...

40 CFR Appendix E to Subpart B of... - The Standard for Automotive Refrigerant Recycling Equipment Intended for Use With Both CFC-12 and...

Code of Federal Regulations, 2011 CFR

2011-07-01

... Refrigerant Recycling Equipment Intended for Use With Both CFC-12 and HFC-134a E Appendix E to Subpart B of... Appendix E to Subpart B of Part 82—The Standard for Automotive Refrigerant Recycling Equipment Intended for... specific minimum equipment requirements for automotive refrigerant recycling equipment intended for use...

On the Scaling Behavior of Reliability-Resilience-Vulnerability ...

EPA Pesticide Factsheets

Risk indices such as reliability-resilience-vulnerability (R-R-V) have been proposed to assess watershed health. In this study, the spatial scaling behavior of R-R-V indices has been explored for five agricultural watersheds in the midwestern United States. The study was conducted using two different measures of spatial scale: (i) the ratio of contributing upland area to area required for channel initiation (FA), and (ii) Strahler stream order. It was found that R-R-V indices do change with spatial scale, but a representative watershed-specific threshold FA value exists for these indices to achieve stable values. Scaling with Strahler stream order is feasible if the watershed possesses a tree-like stream network. As an example of anthropogenic influences, this study also examined the role of BMPs placed within an agricultural watershed via a cost-effective optimization scheme on the evolution of R-R-V values with scale. While the placement of BMPs acheived reductions in concentrations and/or loads of constituents, they may not significantly change watershed risk measures, but are likely to cause significant reduction in vulnerability. If primarily upland BMPs are placed in a diffuse manner throughout the watershed, there might not be a significant change in the scaling behavior of R-R-V values. The primary objective of this study is to investigate the effect of spatial scale on risk-based watershed health assessment. A related objective is to examine wh

Quantitative analysis of peripheral vasculitis, ischemia, and vascular leakage in uveitis using ultra-widefield fluorescein angiography.

PubMed

Karampelas, Michael; Sim, Dawn A; Chu, Colin; Carreno, Ester; Keane, Pearse A; Zarranz-Ventura, Javier; Westcott, Mark; Lee, Richard W J; Pavesio, Carlos E

2015-06-01

To investigate the relationships between peripheral vasculitis, ischemia, and vascular leakage in uveitis using ultra-widefield fluorescein angiography (FA). Cross-sectional, consecutive case series. Consecutive ultra-widefield FA images were collected from 82 uveitis patients (82 eyes) in a single center. The extent of peripheral vasculitis, capillary nonperfusion, and vessel leakage were quantified. Parameters included: (1) foveal avascular zone area and macular leakage, (2) peripheral diffuse capillary leakage and ischemia, (3) peripheral vasculitis, and (4) leakage from neovascularization. Central macular thickness measurements were derived with optical coherence tomography. Main outcome measures were correlations between central and peripheral fluorangiographic changes as well as associations between visual function, ultra-widefield FA-derived metrics, and central macular thickness. Although central leakage was associated with peripheral leakage (r = 0.553, P = .001), there was no association between foveal avascular zone size and peripheral ischemia (r = 0.114, P = .324), regardless of the underlying uveitic diagnosis. Peripheral ischemia was, however, correlated to neovascularization-related leakage (r = 0.462, P = .001) and focal vasculitis (r = 0.441, P = .001). Stepwise multiple regression analysis revealed that a poor visual acuity was independently associated with foveal avascular zone size and central macular thickness (R(2)-adjusted = 0.45, P = .001). We present a large cohort of patients with uveitis imaged with ultra-widefield FA and further describe novel methods for quantification of peripheral vascular pathology, in an attempt to identify visually significant parameters. Although we observed that relationships exist between peripheral vessel leakage, vasculitis, and ischemia, it was only macular ischemia and increased macular thickness that were independently associated with a reduced visual acuity. Copyright © 2015 Elsevier Inc. All rights reserved.

Regulation of Fanconi anemia protein FANCD2 monoubiquitination by miR-302

DOE Office of Scientific and Technical Information (OSTI.GOV)

Suresh, Bharathi; College of Medicine, Hanyang University, Seoul; Kumar, A. Madhan

2015-10-16

Fanconi anemia (FA) is a recessively inherited multigene disease characterized by congenital defects, progressive bone marrow failure, and heightened cancer susceptibility. Monoubiquitination of the FA pathway member FANCD2 contributes to the repair of replication stalling DNA lesions. However, cellular regulation of FANCD2 monoubiquitination remains poorly understood. In the present study, we identified the miR-302 cluster as a potential regulator of FANCD2 by bioinformatics analysis. MicroRNAs (miRNAs) are the major posttranscriptional regulators of a wide variety of biological processes, and have been implicated in a number of diseases. Expression of the exogenous miR-302 cluster (without miR-367) reduced FANCD2 monoubiquitination and nuclearmore » foci formation. Furthermore, miR-302 cells showed extensive chromosomal breakage upon MMC treatment when compared to mock control cells. Taken together, our results suggest that overexpression of miR-302 plays a critical role in the regulation of FANCD2 monoubiquitination, resulting in characteristic defects in DNA repair within cells. - Highlights: • miR-302 binds to the 3′UTR promoter of the FANCD2 gene to regulate gene expression. • miR-302 cluster down-regulates FANCD2 protein expression. • miR-302 cluster reduces FANCD2 monoubiquitination and nuclear foci formation. • miR-302 exhibits the characteristic defects in DNA repair in cells.« less

A minimal threshold of FANCJ helicase activity is required for its response to replication stress or double-strand break repair.

PubMed

Bharti, Sanjay Kumar; Sommers, Joshua A; Awate, Sanket; Bellani, Marina A; Khan, Irfan; Bradley, Lynda; King, Graeme A; Seol, Yeonee; Vidhyasagar, Venkatasubramanian; Wu, Yuliang; Abe, Takuye; Kobayashi, Koji; Shin-Ya, Kazuo; Kitao, Hiroyuki; Wold, Marc S; Branzei, Dana; Neuman, Keir C; Brosh, Robert M

2018-05-21

Fanconi Anemia (FA) is characterized by bone marrow failure, congenital abnormalities, and cancer. Of over 20 FA-linked genes, FANCJ uniquely encodes a DNA helicase and mutations are also associated with breast and ovarian cancer. fancj-/- cells are sensitive to DNA interstrand cross-linking (ICL) and replication fork stalling drugs. We delineated the molecular defects of two FA patient-derived FANCJ helicase domain mutations. FANCJ-R707C was compromised in dimerization and helicase processivity, whereas DNA unwinding by FANCJ-H396D was barely detectable. DNA binding and ATP hydrolysis was defective for both FANCJ-R707C and FANCJ-H396D, the latter showing greater reduction. Expression of FANCJ-R707C or FANCJ-H396D in fancj-/- cells failed to rescue cisplatin or mitomycin sensitivity. Live-cell imaging demonstrated a significantly compromised recruitment of FANCJ-R707C to laser-induced DNA damage. However, FANCJ-R707C expressed in fancj-/- cells conferred resistance to the DNA polymerase inhibitor aphidicolin, G-quadruplex ligand telomestatin, or DNA strand-breaker bleomycin, whereas FANCJ-H396D failed. Thus, a minimal threshold of FANCJ catalytic activity is required to overcome replication stress induced by aphidicolin or telomestatin, or to repair bleomycin-induced DNA breakage. These findings have implications for therapeutic strategies relying on DNA cross-link sensitivity or heightened replication stress characteristic of cancer cells.

Atmospheric histories and global emissions of the anthropogenic hydrofluorocarbons HFC-365mfc, HFC-245fa, HFC-227ea, and HFC-236fa

NASA Astrophysics Data System (ADS)

Vollmer, Martin K.; Miller, Benjamin R.; Rigby, Matthew; Reimann, Stefan; Mühle, Jens; Krummel, Paul B.; O'Doherty, Simon; Kim, Jooil; Rhee, Tae Siek; Weiss, Ray F.; Fraser, Paul J.; Simmonds, Peter G.; Salameh, Peter K.; Harth, Christina M.; Wang, Ray H. J.; Steele, L. Paul; Young, Dickon; Lunder, Chris R.; Hermansen, Ove; Ivy, Diane; Arnold, Tim; Schmidbauer, Norbert; Kim, Kyung-Ryul; Greally, Brian R.; Hill, Matthias; Leist, Michael; Wenger, Angelina; Prinn, Ronald G.

2011-04-01

We report on ground-based atmospheric measurements and emission estimates of the four anthropogenic hydrofluorocarbons (HFCs) HFC-365mfc (CH3CF2CH2CF3, 1,1,1,3,3-pentafluorobutane), HFC-245fa (CHF2CH2CF3, 1,1,1,3,3-pentafluoropropane), HFC-227ea (CF3CHFCF3, 1,1,1,2,3,3,3-heptafluoropropane), and HFC-236fa (CF3CH2CF3, 1,1,1,3,3,3-hexafluoropropane). In situ measurements are from the global monitoring sites of the Advanced Global Atmospheric Gases Experiment (AGAGE), the System for Observations of Halogenated Greenhouse Gases in Europe (SOGE), and Gosan (South Korea). We include the first halocarbon flask sample measurements from the Antarctic research stations King Sejong and Troll. We also present measurements of archived air samples from both hemispheres back to the 1970s. We use a two-dimensional atmospheric transport model to simulate global atmospheric abundances and to estimate global emissions. HFC-365mfc and HFC-245fa first appeared in the atmosphere only ˜1 decade ago; they have grown rapidly to globally averaged dry air mole fractions of 0.53 ppt (in parts per trillion, 10-12) and 1.1 ppt, respectively, by the end of 2010. In contrast, HFC-227ea first appeared in the global atmosphere in the 1980s and has since grown to ˜0.58 ppt. We report the first measurements of HFC-236fa in the atmosphere. This long-lived compound was present in the atmosphere at only 0.074 ppt in 2010. All four substances exhibit yearly growth rates of >8% yr-1 at the end of 2010. We find rapidly increasing emissions for the foam-blowing compounds HFC-365mfc and HFC-245fa starting in ˜2002. After peaking in 2006 (HFC-365mfc: 3.2 kt yr-1, HFC-245fa: 6.5 kt yr-1), emissions began to decline. Our results for these two compounds suggest that recent estimates from long-term projections (to the late 21st century) have strongly overestimated emissions for the early years of the projections (˜2005-2010). Global HFC-227ea and HFC-236fa emissions have grown to average values of 2.4 kt yr-1 and 0.18 kt yr-1 over the 2008-2010 period, respectively.

The Primordial Inflation Polarization ExploreR Continuous Adiabatic Demagnetization Refrigerator

NASA Astrophysics Data System (ADS)

Pawlyk, Samuel; Ade, Peter; Benford, Dominic; Bennett, Charles; Chuss, David; Datta, Rahul; Dotson, Jessie; Essinger-Hileman, Thomas; Fixsen, Dale; Halpern, Mark; Hilton, Gene; Hinshaw, Gary; Irwin, Kent; Jhabvala, Christine; Kimball, Mark; Kogut, Al; Lowe, Luke; McMahon, Jeff; Miller, Timothy; Mirel, Paul; Moseley, Samuel Harvey; Rodriguez, Samelys; Sharp, Elmer; Shirron, Peter; Staguhn, Johannes G.; Sullivan, Dan; Switzer, Eric; Taraschi, Peter; Tucker, Carole; Wollack, Edward; Walts, Alexander

2018-01-01

The Primordial Inflation Polarization ExploreR (PIPER) uses a Continuous Adiabatic Demagnetization Refrigerator (CADR) to cool its detectors. The CADR consists of four independent stages with adjacent stages connected by gas gap (GG) or superconducting (SC) heat switches. The three warm stages cycle to transfer heat from the 100 mK detector package to the 1.5 K liquid helium bath. The coldest stage maintains a continuous temperature of 100 mK for the detector package with 10 uW cooling power. We describe the mechanical, electrical, and software design of the CADR and present recent results.

Status of not-in-kind refrigeration technologies for household space conditioning, water heating and food refrigeration

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bansal, Pradeep; Vineyard, Edward Allan; Abdelaziz, Omar

This paper presents a review of the next generation not-in-kind technologies to replace conventional vapor compression refrigeration technology for household applications. Such technologies are sought to provide energy savings or other environmental benefits for space conditioning, water heating and refrigeration for domestic use. These alternative technologies include: thermoacoustic refrigeration, thermoelectric refrigeration, thermotunneling, magnetic refrigeration, Stirling cycle refrigeration, pulse tube refrigeration, Malone cycle refrigeration, absorption refrigeration, adsorption refrigeration, and compressor driven metal hydride heat pumps. Furthermore, heat pump water heating and integrated heat pump systems are also discussed due to their significant energy saving potential for water heating and space conditioningmore » in households. The paper provides a snapshot of the future R&D needs for each of the technologies along with the associated barriers. Both thermoelectric and magnetic technologies look relatively attractive due to recent developments in the materials and prototypes being manufactured.« less

A Study of the Department of Defense Configuration Management Policies and Procedures as Applied to the FA-18 Strike/Fighter Program.

DTIC Science & Technology

1987-06-01

tempt to lower o, vera II progr am ccost.s. "t It A I Ji rt), .! the t w, air-:r att. t.hat t. he FA Id i I 1- :2,i- I e Lip I k , I F r , v i s a c:ase...Although the decision to compete the [ Alo TPS’s was made in mid CY-81, not a single production :: had been delivered to the fleet by Harris GSSD or : .j

Role of the TGFBeta1 in the Prevention of Prostate Cancer

DTIC Science & Technology

2002-04-01

benzothiophene analog with bone efficacy comple- prostate. In Lepor H, Lawson R (eds): Prostate Diseases. Phil - mentary to PTH (1-34). Endocrinology...R., Brachman, D. G.. Beckett , M. A., Virudachalam, S., Yandell. D. W., and Weichselbaum, R. R. Two prostate carcinoma 1. Landis, S. H., Murray, T

Abnormal white matter properties in adolescent girls with anorexia nervosa

PubMed Central

Travis, Katherine E.; Golden, Neville H.; Feldman, Heidi M.; Solomon, Murray; Nguyen, Jenny; Mezer, Aviv; Yeatman, Jason D.; Dougherty, Robert F.

2015-01-01

Anorexia nervosa (AN) is a serious eating disorder that typically emerges during adolescence and occurs most frequently in females. To date, very few studies have investigated the possible impact of AN on white matter tissue properties during adolescence, when white matter is still developing. The present study evaluated white matter tissue properties in adolescent girls with AN using diffusion MRI with tractography and T1 relaxometry to measure R1 (1/T1), an index of myelin content. Fifteen adolescent girls with AN (mean age = 16.6 years ± 1.4) were compared to fifteen age-matched girls with normal weight and eating behaviors (mean age = 17.1 years ± 1.3). We identified and segmented 9 bilateral cerebral tracts (18) and 8 callosal fiber tracts in each participant's brain (26 total). Tract profiles were generated by computing measures for fractional anisotropy (FA) and R1 along the trajectory of each tract. Compared to controls, FA in the AN group was significantly decreased in 4 of 26 white matter tracts and significantly increased in 2 of 26 white matter tracts. R1 was significantly decreased in the AN group compared to controls in 11 of 26 white matter tracts. Reduced FA in combination with reduced R1 suggests that the observed white matter differences in AN are likely due to reductions in myelin content. For the majority of tracts, group differences in FA and R1 did not occur within the same tract. The present findings have important implications for understanding the neurobiological factors underlying white matter changes associated with AN and invite further investigations examining associations between white matter properties and specific physiological, cognitive, social, or emotional functions affected in AN. PMID:26740918

Multimodal Theranostic Nanoformulations Permit Magnetic Resonance Bioimaging of Antiretroviral Drug Particle Tissue-Cell Biodistribution

PubMed Central

Kevadiya, Bhavesh D.; Woldstad, Christopher; Ottemann, Brendan M.; Dash, Prasanta; Sajja, Balasrinivasa R.; Lamberty, Benjamin; Morsey, Brenda; Kocher, Ted; Dutta, Rinku; Bade, Aditya N.; Liu, Yutong; Callen, Shannon E.; Fox, Howard S.; Byrareddy, Siddappa N.; McMillan, JoEllyn M.; Bronich, Tatiana K.; Edagwa, Benson J.; Boska, Michael D.; Gendelman, Howard E.

2018-01-01

RATIONALE: Long-acting slow effective release antiretroviral therapy (LASER ART) was developed to improve patient regimen adherence, prevent new infections, and facilitate drug delivery to human immunodeficiency virus cell and tissue reservoirs. In an effort to facilitate LASER ART development, “multimodal imaging theranostic nanoprobes” were created. These allow combined bioimaging, drug pharmacokinetics and tissue biodistribution tests in animal models. METHODS: Europium (Eu3+)- doped cobalt ferrite (CF) dolutegravir (DTG)- loaded (EuCF-DTG) nanoparticles were synthesized then fully characterized based on their size, shape and stability. These were then used as platforms for nanoformulated drug biodistribution. RESULTS: Folic acid (FA) decoration of EuCF-DTG (FA-EuCF-DTG) nanoparticles facilitated macrophage targeting and sped drug entry across cell barriers. Macrophage uptake was higher for FA-EuCF-DTG than EuCF-DTG nanoparticles with relaxivities of r2 = 546 mM-1s-1 and r2 = 564 mM-1s-1 in saline, and r2 = 850 mM-1s-1 and r2 = 876 mM-1s-1 in cells, respectively. The values were ten or more times higher than what was observed for ultrasmall superparamagnetic iron oxide particles (r2 = 31.15 mM-1s-1 in saline) using identical iron concentrations. Drug particles were detected in macrophage Rab compartments by dual fluorescence labeling. Replicate particles elicited sustained antiretroviral responses. After parenteral injection of FA-EuCF-DTG and EuCF-DTG into rats and rhesus macaques, drug, iron and cobalt levels, measured by LC-MS/MS, magnetic resonance imaging, and ICP-MS were coordinate. CONCLUSION: We posit that these theranostic nanoprobes can assess LASER ART drug delivery and be used as part of a precision nanomedicine therapeutic strategy. PMID:29290806

40 CFR Appendix D to Subpart B of... - SAE J2810 Standard for Recovery Only Equipment for HFC-134a Refrigerant

Code of Federal Regulations, 2011 CFR

2011-07-01

...) refrigerant to be returned to a refrigerant reclamation facility that will process it to the appropriate ARI... and Assembly Processes (Process FMEA) and Effects Analysis for Machinery (Machinery FMEA). SAE... Manufacturing and Assembly Processes (Process FMEA), and Potential Failure Mode and Effects Analysis for...

40 CFR Appendix D to Subpart B of... - SAE J2810 Standard for Recovery Only Equipment for HFC-134a Refrigerant

Code of Federal Regulations, 2013 CFR

2013-07-01

...) refrigerant to be returned to a refrigerant reclamation facility that will process it to the appropriate ARI... and Assembly Processes (Process FMEA) and Effects Analysis for Machinery (Machinery FMEA). SAE... Manufacturing and Assembly Processes (Process FMEA), and Potential Failure Mode and Effects Analysis for...

40 CFR Appendix D to Subpart B of... - SAE J2810 Standard for Recovery Only Equipment for HFC-134a Refrigerant

Code of Federal Regulations, 2012 CFR

2012-07-01

...) refrigerant to be returned to a refrigerant reclamation facility that will process it to the appropriate ARI... and Assembly Processes (Process FMEA) and Effects Analysis for Machinery (Machinery FMEA). SAE... Manufacturing and Assembly Processes (Process FMEA), and Potential Failure Mode and Effects Analysis for...

40 CFR Appendix D to Subpart B of... - SAE J2810 Standard for Recovery Only Equipment for HFC-134a Refrigerant

Code of Federal Regulations, 2010 CFR

2010-07-01

...) refrigerant to be returned to a refrigerant reclamation facility that will process it to the appropriate ARI... and Assembly Processes (Process FMEA) and Effects Analysis for Machinery (Machinery FMEA). SAE... Manufacturing and Assembly Processes (Process FMEA), and Potential Failure Mode and Effects Analysis for...

40 CFR Appendix D to Subpart B of... - SAE J2810 Standard for Recovery Only Equipment for HFC-134a Refrigerant

Code of Federal Regulations, 2014 CFR

2014-07-01

...) refrigerant to be returned to a refrigerant reclamation facility that will process it to the appropriate ARI... and Assembly Processes (Process FMEA) and Effects Analysis for Machinery (Machinery FMEA). SAE... Manufacturing and Assembly Processes (Process FMEA), and Potential Failure Mode and Effects Analysis for...

Decreased Nicotinic Receptor Availability in Smokers with Slow Rates of Nicotine Metabolism.

PubMed

Dubroff, Jacob G; Doot, Robert K; Falcone, Mary; Schnoll, Robert A; Ray, Riju; Tyndale, Rachel F; Brody, Arthur L; Hou, Catherine; Schmitz, Alexander; Lerman, Caryn

2015-11-01

The nicotine metabolite ratio (NMR), a stable measure of hepatic nicotine metabolism via the CYP2A6 pathway and total nicotine clearance, is a predictive biomarker of response to nicotine replacement therapy, with increased quit rates in slower metabolizers. Nicotine binds directly to nicotinic acetylcholine receptors (nAChRs) to exert its psychoactive effects. This study examined the relationship between NMR and nAChR (α4β2* subtype) availability using PET imaging of the radiotracer 2-(18)F-fluoro-3-(2(S)-azetidinylmethoxy)pyridine (2-(18)F-FA-85380, or 2-(18)F-FA). Twenty-four smokers-12 slow metabolizers (NMR < 0.26) and 12 normal metabolizers (NMR ≥ 0.26)-underwent 2-(18)F-FA-PET brain imaging after overnight nicotine abstinence (18 h before scanning), using a validated bolus-plus-infusion protocol. Availability of nAChRs was compared between NMR groups in a priori volumes of interest, with total distribution volume (VT/fP) being the measure of nAChR availability. Cravings to smoke were assessed before and after the scans. Thalamic nAChR α4β2* availability was significantly reduced in slow nicotine metabolizers (P = 0.04). Slow metabolizers exhibited greater reductions in cravings after scanning than normal metabolizers; however, craving was unrelated to nAChR availability. The rate of nicotine metabolism is associated with thalamic nAChR availability. Additional studies could examine whether altered nAChR availability underlies the differences in treatment response between slow and normal metabolizers of nicotine. © 2015 by the Society of Nuclear Medicine and Molecular Imaging, Inc.

Early Permian transgressive-regressive cycles: Sequence stratigraphic reappraisal of the coal-bearing Barakar Formation, Raniganj Basin, India

NASA Astrophysics Data System (ADS)

Bhattacharya, Biplab; Bhattacharjee, Joyeeta; Bandyopadhyay, Sandip; Banerjee, Sudipto; Adhikari, Kalyan

2018-03-01

The present research is an attempt to assess the Barakar Formation of the Raniganj Gondwana Basin, India, in the frame of fluvio-marine (estuarine) depositional systems using sequence stratigraphic elements. Analysis of predominant facies associations signify deposition in three sub-environments: (i) a river-dominated bay-head delta zone in the inner estuary, with transition from braided fluvial channels (FA-B1) to tide-affected meandering fluvial channels and flood plains (FA-B2) in the basal part of the succession; (ii) a mixed energy central basin zone, which consists of transitional fluvio-tidal channels (FA-B2), tidal flats, associated with tidal channels and bars (FA-B3) in the middle-upper part of the succession; and (iii) a wave-dominated outer estuary (coastal) zone (FA-B4 with FA-B3) in the upper part of the succession. Stacked progradational (P1, P2)-retrogradational (R1, R2) successions attest to one major base level fluctuation, leading to distinct transgressive-regressive (T-R) cycles with development of initial falling stage systems tract (FSST), followed by lowstand systems tract (LST) and successive transgressive systems tracts (TST-1 and TST-2). Shift in the depositional regime from regressive to transgressive estuarine system in the early Permian Barakar Formation is attributed to change in accommodation space caused by mutual interactions of (i) base level fluctuations in response to climatic amelioration and (ii) basinal tectonisms (exhumation/sagging) related to post-glacial isostatic adjustments in the riftogenic Gondwana basins.

Evaluating alternative refrigerants for high ambient temperature environments

DOE PAGES

Abdelaziz, Omar; Shrestha, Som S.

2016-01-01

According to the Montreal Protocol, developing countries have started the phase out schedule of the ozone depleting substances, including HCFC refrigerants, in 2015 and expect them to reach 35% reduction in 2020. This commitment to the start the phase out of HCFC refrigerants, especially R-22, in developing countries is seen as an opportunity to introduce lower Global Warming Potential (GWP) refrigerants. Furthermore, this paper summarizes an investigation into the performance of lower GWP refrigerants in high ambient temperature environments, experienced in some of the developed countries, in mini-split air conditioning units.

Multi-parametric spinal cord MRI as potential progression marker in amyotrophic lateral sclerosis.

PubMed

El Mendili, Mohamed-Mounir; Cohen-Adad, Julien; Pelegrini-Issac, Mélanie; Rossignol, Serge; Morizot-Koutlidis, Régine; Marchand-Pauvert, Véronique; Iglesias, Caroline; Sangari, Sina; Katz, Rose; Lehericy, Stéphane; Benali, Habib; Pradat, Pierre-François

2014-01-01

To evaluate multimodal MRI of the spinal cord in predicting disease progression and one-year clinical status in amyotrophic lateral sclerosis (ALS) patients. After a first MRI (MRI1), 29 ALS patients were clinically followed during 12 months; 14/29 patients underwent a second MRI (MRI2) at 11±3 months. Cross-sectional area (CSA) that has been shown to be a marker of lower motor neuron degeneration was measured in cervical and upper thoracic spinal cord from T2-weighted images. Fractional anisotropy (FA), axial/radial/mean diffusivities (λ⊥, λ//, MD) and magnetization transfer ratio (MTR) were measured within the lateral corticospinal tract in the cervical region. Imaging metrics were compared with clinical scales: Revised ALS Functional Rating Scale (ALSFRS-R) and manual muscle testing (MMT) score. At MRI1, CSA correlated significantly (P<0.05) with MMT and arm ALSFRS-R scores. FA correlated significantly with leg ALFSRS-R scores. One year after MRI1, CSA predicted (P<0.01) arm ALSFSR-R subscore and FA predicted (P<0.01) leg ALSFRS-R subscore. From MRI1 to MRI2, significant changes (P<0.01) were detected for CSA and MTR. CSA rate of change (i.e. atrophy) highly correlated (P<0.01) with arm ALSFRS-R and arm MMT subscores rate of change. Atrophy and DTI metrics predicted ALS disease progression. Cord atrophy was a better biomarker of disease progression than diffusion and MTR. Our study suggests that multimodal MRI could provide surrogate markers of ALS that may help monitoring the effect of disease-modifying drugs.

Alternative refrigerants and refrigeration cycles for domestic refrigerators

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sand, J.R.; Rice, C.L.; Vineyard, E.A.

1992-12-01

This project initially focused on using nonazeotropic refrigerant mixtures (NARMs) in a two-evaporator refrigerator-freezer design using two stages of liquid refrigerant subcooling. This concept was proposed and tested in 1975. The work suggested that the concept was 20% more efficient than the conventional one-evaporator refrigerator-freezer (RF) design. After considerable planning and system modeling based on using a NARM in a Lorenz-Meutzner (L-M) RF, the program scope was broadened to include investigation of a ``dual-loop`` concept where energy savings result from exploiting the less stringent operating conditions needed to satisfy cooling, of the fresh food section. A steady-state computer model (CYCLE-Z)more » capable of simulating conventional, dual loop, and L-M refrigeration cycles was developed. This model was used to rank the performance of 20 ozone-safe NARMs in the L-M refrigeration cycle while key system parameters were systematically varied. The results indicated that the steady-state efficiency of the L-M design was up to 25% greater than that of a conventional cycle. This model was also used to calculate the performance of other pure refrigerants relative to that of dichlorodifluoromethane, R-12, in conventional and dual-loop RF designs. Projected efficiency gains for these cycles were more modest, ranging from 0 to 10%. Individual compressor calorimeter tests of nine combinations of evaporator and condenser temperatures usually used to map RF compressor performance were carried out with R-12 and two candidate L-M NARMs in several compressors. Several models of a commercially produced two-evaporator RF were obtained as test units. Two dual-loop RF designs were built and tested as part of this project.« less

Stability and pre-formulation development of a plant-produced anthrax vaccine candidate.

PubMed

Jones, R Mark; Burke, Michael; Dubose, Devon; Chichester, Jessica A; Manceva, Slobodanka; Horsey, April; Streatfield, Stephen J; Breit, Jeff; Yusibov, Vidadi

2017-10-04

Second generation anthrax vaccines focus on the use of recombinant protective antigen (rPA) to elicit a strong, toxin neutralizing antibody responses in immunized subjects. The main difference between the rPA vaccines compared to the current licensed vaccine, anthrax vaccine absorbed (AVA), is the rPA vaccines are highly purified preparations of only rPA. These second generation rPA vaccines strive to elicit strong immune responses with substantially fewer doses than AVA while provoking less side effects. Many of the rPA candidates have shown to be effective in pre-clinical studies, but most of the second generation molecules have stability issues which reduce their efficacy over time. These stability issues are evident even under refrigerated conditions and thus emphasis has been directed to stabilizing the rPA molecule and determining an optimized final formulation. Stabilization of vaccines for long-term storage is a major challenge in the product development life cycle. The effort required to identify suitable formulations can be slow and expensive. The ideal storage for stockpiled vaccines would allow the candidate to withstand years of storage at ambient temperatures. The Fraunhofer Center for Molecular Biotechnology is developing a plant-produced rPA vaccine candidate that shows instability when stored under refrigerated conditions in a solution, as is typical for rPA vaccines. Increased stability of our plant-produced rPA vaccine candidate was achieved in a spray dried powder formulation that could eliminate the need for conventional cold chain allowing greater confidence to stockpile vaccine for civilian and military biodefense. Copyright © 2017 Elsevier Ltd. All rights reserved.

Influence of abutment type and esthetic veneering on preload maintenance of abutment screw of implant-supported crowns.

PubMed

Delben, Juliana Aparecida; Barão, Valentim Adelino Ricardo; Dos Santos, Paulo Henrique; Assunção, Wirley Gonçalves

2014-02-01

The effect of veneering materials on screw joint stability remains inconclusive. Thus, this study evaluated the preload maintenance of abutment screws of single crowns fabricated with different abutments and veneering materials. Sixty crowns were divided into five groups (n = 12): UCLA abutment in gold alloy with ceramic (group GC) and resin (group GR) veneering, UCLA abutment in titanium with ceramic (group TiC) and resin (group TiR) veneering, and zirconia abutment with ceramic veneering (group ZiC). Abutment screws made of gold were used with a 35 Ncm insertion torque. Detorque measurements were obtained initially and after mechanical cycling. Data were analyzed by ANOVA and Fisher's exact test at a significance level of 5%. For the initial detorque means (in Ncm), group TiC (21.4 ± 1.78) exhibited statistically lower torque maintenance than groups GC (23.9 ± 0.91), GR (24.1 ± 1.34), and TiR (23.2 ± 1.33) (p < 0.05, Fisher's exact test). Group ZiC (21.9 ± 2.68) exhibited significantly lower torque maintenance than groups GC, GR, and TiR (p < 0.05, Fisher's exact test). After mechanical cycling, there was a statistically significant difference between groups TiC (22.1 ± 1.86) and GR (23.8 ± 1.56); between groups ZiC (21.7 ± 2.02) and GR; and also between groups ZiC and TiR (23.6 ± 1.30) (p < 0.05, Fisher's exact test). Detorque reduction occurred regardless of abutment type and veneering material. More irregular surfaces in the hexagon area of the castable abutments were observed. The superiority of any veneering material concerning preload maintenance was not established. © 2013 by the American College of Prosthodontists.

Magnetocaloric Refrigeration.

DTIC Science & Technology

1987-03-01

calculated by Griffel et al. (121 is correct. 13 ,"’L * Thermal conductivity in gadolinium is not a function of temperature. " The adiabatic...Capability for NASTRAN Using Isoparametric Finite ,. Elements," DTNSRDC Report CMC-1-73 (Jan 1973). 12. Griffel , M., R.E. Skochdopole, R.E., and F.H. Spedding

Justification of Estimates for Fiscal Years 1988 and 1989 Submitted to Congress

DTIC Science & Technology

1987-02-01

G-M’^ t-> C ^ in os: C to> ©MOOHO 10 P— to>>C£>JP,«U-^ > X-H.* ■3to©p©a.n z —i bPP ^kitO© .won’CO^IO...oiXIH » •w B e.x fa<S -ri& faB ^X B a B rH - »I fa «•O 01 01 B a al1 & fc,_*j.H o fa e-co O XBBV+JOIBB fa •BEOIOJUBE, B Q

Resveratrol prevents cognitive deficits induced by chronic unpredictable mild stress: Sirt1/miR-134 signalling pathway regulates CREB/BDNF expression in hippocampus in vivo and in vitro.

PubMed

Shen, Jun; Xu, Linling; Qu, Chujie; Sun, Huimin; Zhang, Junjian

2018-04-30

Chronic unpredictable mild stress (CUMS) leads to neuropsychiatric disorders, such as depression, anxiety and cognitive impairment. Resveratrol is a natural polyphenol existed in polygonum cuspidatum and has been demonstrated to be a potent activator of Sirtuin 1 (Sirt1). Previous studies reported that resveratrol treatment ameliorated CUMS-induced depressive-like behavior and cognitive deficits through upregulating cAMP response element-binding protein (CREB) and brain derived neurotrophic factor (BDNF) expression. However, the upstream signalling pathway mediating CREB/BDNF expression and then exerting a protective role on cognitive function remains unclear. The present study aims to investigate the possible mechanism of resveratrol on CUMS-induced cognitive deficits. Male Sprague Dawley rats were adminstrated resveratrol (40 and 80 mg/kg) every day for 4 consecutive weeks before exposure to CUMS procedure. Morris Water Maze test was used to appraise spatial learing and memory of rats. Sirt1/miR-134 signalling pathway and CREB/BDNF expression in hippocampus of rats were measured. We also explored Sirt1/miR-134 signalling pathway and CREB/BDNF expression in primary cultured hippocampus neurons with resveratrol (25, 50 and 100 μmol/L) treatment. We found that resveratrol treatment prevented spatial learing and memory impairment induced by CUMS. Meanwhile the potential mechanism of resveratrol was associated with increased levels of Sirt1, CREB phosphorylation (p-CREB), CREB, BDNF and decreased levels of miR-134 in vivo and in vitro. In conclusion, our study showed that the neuroprotective effect of resveratrol on CUMS-induced cognitive impairment may rely on activating Sirt1/miR-134 pathway and then upregulating its downstream CREB/BDNF expression in hippocampus. Copyright © 2018 Elsevier B.V. All rights reserved.

Optical Cooling in Er3+:KPb2Cl5

DTIC Science & Technology

2009-01-01

and C. .E. Mungan, “Observation of laser- induced fluorescent cooling of a solid,” Nature 377, 500-503 (1995). 4. C. W. Hoyt, M. Sheik- Bahae , R. I ...cooling by spontaneous anti-Stokes scattering,” Phys. Rev. Lett. 46, 236-239 (1981). 3. R. I . Epstein, M. I . Buchwald, B. C. Edwards, T. R. Gosnell...2000). 5. S. R. Bowman and C. E. Mungan, “New materials for optical cooling,” Appl. Phys. B 71, 807-811 (2000). 6. R. I . Epstein, J. J. Brown, B. C

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shen, Bo; Abdelaziz, Omar; Shrestha, Som S.

Based on the laboratory investigation in FY16, for R-22 and R-410A alternative low GWP refrigerants in two baseline rooftop air conditioners (RTU), we used the DOE/ORNL Heat Pump Design Model to model the two RTUs and calibrated the models against the experimental data. Using the calibrated equipment models, we compared the compressor efficiencies, heat exchanger performances. An efficiency-based compressor mapping method was developed, which is able to predict compressor performances of the alternative low GWP refrigerants accurately. Extensive model-based optimizations were conducted to provide a fair comparison between all the low GWP candidates by selecting their preferred configurations at themore » same cooling capacity and compressor efficiencies.« less

Illinois Occupational Skill Standards: HVAC/R Technician Cluster.

ERIC Educational Resources Information Center

Illinois Occupational Skill Standards and Credentialing Council, Carbondale.

This document, which is intended to serve as a guide for work force preparation program providers, details the Illinois occupational skill standards for programs preparing students for employment in jobs in the heating, ventilation, air conditioning, and refrigeration (HVAC/R) industry. Agency partners involved in this project include: the…

INVESTIGATION OF AMMONIA EQUIPMENT CONFIGURATIONS FOR SUPERMARKET REFRIGERATION APPLICATIONS. Project Summary (EPA/600/SR-95/028)

EPA Science Inventory

The report gives results of a study that provided information regarding the merits of using ammonia with a secondary brine loop for supermarket refrigeration systems. The ammonia systems were compared with an equivalent R-22 system. The models used in the study are provided with...

Toxicokinetics of amphetamines: metabolism and toxicokinetic data of designer drugs, amphetamine, methamphetamine, and their N-alkyl derivatives.

PubMed

Kraemer, Thomas; Maurer, Hans H

2002-04-01

This paper reviews the toxicokinetics of amphetamines. The designer drugs MDA (methylenedioxy-amphetamine, R,S-1-(3;,4;-methylenedioxyphenyl)2-propanamine), MDMA (R,S-methylenedioxymethamphetamine), and MDE (R,S-methylenedioxyethylamphetamine), as well as BDB (benzodioxolylbutanamine; R,S-1-(1;,3;-benzodioxol-5;-yl)-2-butanamine or R,S-1-(3;,4;-methylenedioxyphenyl)-2-butanamine) and MBDB (R,S-N-methyl-benzodioxolylbutanamine), were taken into consideration, as were the following N-alkylated amphetamine derivatives: amphetaminil, benzphetamine, clobenzorex, dimethylamphetamine, ethylamphetamine, famprofazone, fencamine, fenethylline, fenproporex, furfenorex, mefenorex, mesocarb, methamphetamine, prenylamine, and selegiline. English-language publications from 1995 to 2000 were reviewed. Papers describing identification of metabolites or cytochrome P450 isoenzyme-dependent metabolism and papers containing pharmacokinetic/toxicokinetic data were considered and summarized. The implications of toxicokinetics for toxicologic assessment or for interpretation in forensic cases are discussed.

Summaries of Papers presented at the Picosecond Electronics and Optoelectronics Topical Meeting Held in Incline Village, Nevada on January 14-16, 1987. Conference Edition.

DTIC Science & Technology

1987-10-10

Invted Paper) Yen, Hughes Research Laboratories. Design and fabrica- FA1 Hgh-Spmd Phenomena In GaAs Quantum Wells, A. tion of wideband and high-speed...App!. Phys., 49 1119�). 5. A.M. Johnson, D.I. Auston, P.R. Smith, J.C. Dean, i.P. Harbison, and D. Kaplan ,r "Picosecond Photoconductivity in...JANUARY 16, 1987 PROSPECTOR! RUBICON ROOM 8:00 A.M.-9:30 A.M. FA1 -4 QUANTUM-WELL PHYSICS AND DEVICES C. Weisbuch, Thomson CSF, Presider .4

Anti-Stokes Luminescence Cooling of Tm3+Doped BaY2F8

DTIC Science & Technology

2008-02-04

edited by Richard I . Epstein, Mansoor Sheik- Bahae , Proc. SPIE 6461 (Bellingham, Washington, 2007). 2. R.I. Epstein, M.I. Buchwald, B.C. Edwards, T.R...Greenfield, R.I. Epstein, ”Cooling to 208 K by optical refrigeration,” Appl. Phys. Lett. 86, 154107 (2005). 4. M. Sheik- Bahae , R. Epstein, ”Can laser...light cool semiconductors?,” Phys. Rev. Lett. 92, 247403 (2004). 5. C.W. Hoyt, M. Sheik- Bahae , R.I. Epstein, B.C. Edwards, J.E. Anderson, ”Observation of

Magnetic properties and magnetocaloric effect of HoCo3B2 compound

NASA Astrophysics Data System (ADS)

Zheng, X. Q.; Xu, J. W.; Zhang, H.; Zhang, J. Y.; Wang, S. G.; Zhang, Y.; Xu, Z. Y.; Wang, L. C.; Shen, B. G.

2018-05-01

A sample of HoCo3B2 compound was synthesized, and the magnetic and MCE properties were investigated. Compound shows a change corresponding to R-R (R = rare earth) sublattice magnetic order transition and the transition temperature is determined to be 11.8 K (TC). The characteristic of Arrott plots with positive slope around TC was observed, indicating a second-order phase transition. Based on isothermal magnetization data, together with Maxwell's relationship, the magnetic entropy change (-ΔSM) was calculated. The maximum -ΔSM reaches 7.8, 12.7 and 14.4 J/kg K for field range of 0-2 T, 0-5 T and 0-7 T, respectively. Accordingly, the value of RC (refrigerant capacity) is 99, 289 and 432 J/kg for above field ranges. The large MCE of HoCo3B2 compound indicates its potential application for magnetic refrigeration in low temperature range.

40 CFR Appendix G to Subpart G of... - Substitutes Subject to Use Restrictions and Unacceptable Substitutes Listed in the March 3, 1999...

Code of Federal Regulations, 2010 CFR

2010-07-01

.... Refrigerants Unacceptable Substitutes End-use Substitute Decision Comments CFC-12, R-502, and HCFC-22 Household... gas emissions from direct release of refrigerant to the atmosphere. [64 FR 10378, Mar. 3, 1999] ...

40 CFR Appendix G to Subpart G of... - Substitutes Subject to Use Restrictions and Unacceptable Substitutes Listed in the March 3, 1999...

Code of Federal Regulations, 2011 CFR

2011-07-01

.... Refrigerants Unacceptable Substitutes End-use Substitute Decision Comments CFC-12, R-502, and HCFC-22 Household... gas emissions from direct release of refrigerant to the atmosphere. [64 FR 10378, Mar. 3, 1999] ...

Vapor-liquid equilibria for an R134a/lubricant mixture: Measurements and equation-of-state modeling

DOE Office of Scientific and Technical Information (OSTI.GOV)

Huber, M.L.; Holcomb, C.D.; Outcalt, S.L.

2000-07-01

The authors measured bubble point pressures and coexisting liquid densities for two mixtures of R-134a and a polyolester (POE) lubricant. The mass fraction of the lubricant was approximately 9% and 12%, and the temperature ranged from 280 K to 355 K. The authors used the Elliott, Suresh, and Donohue (ESD) equation of state to model the bubble point pressure data. The bubble point pressures were represented with an average absolute deviation of 2.5%. A binary interaction parameter reduced the deviation to 1.4%. The authors also applied the ESD model to other R-134a/POE lubricant data in the literature. As the concentrationmore » of the lubricant increased, the performance of the model deteriorated markedly. However, the use of a single binary interaction parameter reduced the deviations significantly.« less

Multi-Parametric Spinal Cord MRI as Potential Progression Marker in Amyotrophic Lateral Sclerosis

PubMed Central

El Mendili, Mohamed-Mounir; Cohen-Adad, Julien; Pelegrini-Issac, Mélanie; Rossignol, Serge; Morizot-Koutlidis, Régine; Marchand-Pauvert, Véronique; Iglesias, Caroline; Sangari, Sina; Katz, Rose; Lehericy, Stéphane; Benali, Habib; Pradat, Pierre-François

2014-01-01

Objective To evaluate multimodal MRI of the spinal cord in predicting disease progression and one-year clinical status in amyotrophic lateral sclerosis (ALS) patients. Materials and Methods After a first MRI (MRI1), 29 ALS patients were clinically followed during 12 months; 14/29 patients underwent a second MRI (MRI2) at 11±3 months. Cross-sectional area (CSA) that has been shown to be a marker of lower motor neuron degeneration was measured in cervical and upper thoracic spinal cord from T2-weighted images. Fractional anisotropy (FA), axial/radial/mean diffusivities (λ⊥, λ//, MD) and magnetization transfer ratio (MTR) were measured within the lateral corticospinal tract in the cervical region. Imaging metrics were compared with clinical scales: Revised ALS Functional Rating Scale (ALSFRS-R) and manual muscle testing (MMT) score. Results At MRI1, CSA correlated significantly (P<0.05) with MMT and arm ALSFRS-R scores. FA correlated significantly with leg ALFSRS-R scores. One year after MRI1, CSA predicted (P<0.01) arm ALSFSR-R subscore and FA predicted (P<0.01) leg ALSFRS-R subscore. From MRI1 to MRI2, significant changes (P<0.01) were detected for CSA and MTR. CSA rate of change (i.e. atrophy) highly correlated (P<0.01) with arm ALSFRS-R and arm MMT subscores rate of change. Conclusion Atrophy and DTI metrics predicted ALS disease progression. Cord atrophy was a better biomarker of disease progression than diffusion and MTR. Our study suggests that multimodal MRI could provide surrogate markers of ALS that may help monitoring the effect of disease-modifying drugs. PMID:24755826

Altered Fruit and Seed Development of Transgenic Rapeseed (Brassica napus) Over-Expressing MicroRNA394

PubMed Central

Song, Jian Bo; Shu, Xia Xia; Shen, Qi; Li, Bo Wen; Song, Jun; Yang, Zhi Min

2015-01-01

Fruit and seed development in plants is a complex biological process mainly involved in input and biosynthesis of many storage compounds such as proteins and oils. Although the basic biochemical pathways for production of the storage metabolites in plants are well characterized, their regulatory mechanisms are not fully understood. In this study, we functionally identified rapeseed (Brassica napus) miR394 with its target gene Brassica napus LEAF CURLING RESPONSIVENESS (BnLCR) to dissect a role of miR394 during the fruit and seed development. Transgenic rapeseed plants over-expressing miR394 under the control of the cauliflower mosaic virus 35S promoter were generated. miR394 over-expression plants exhibited a delayed flowering time and enlarged size of plants, leaf blade, pods and seed body, but developed seeds with higher contents of protein and glucosinolates (GLS) and lower levels of oil accumulation as compared to wild-type. Over-expression of miR394 altered the fatty acid (FA) composition by increasing several FA species such as C16:0 and C18:0 and unsaturated species of C20:1 and C22:1 but lowering C18:3. This change was accompanied by induction of genes coding for transcription factors of FA synthesis including LEAFY COTYLEDON1 (BnLEC1), BnLEC2, and FUSCA3 (FUS3). Because the phytohormone auxin plays a crucial role in fruit development and seed patterning, the DR5-GUS reporter was used for monitoring the auxin response in Arabidopsis siliques and demonstrated that the DR5 gene was strongly expressed. These results suggest that BnmiR394 is involved in rapeseed fruit and seed development. PMID:25978066

Flight Problems, Problems in Starting Service,

DTIC Science & Technology

1977-01-03

h i l e a t the same time preserving hi gh f l i g h t r egu la r i t~ l e a d s to t h e fa c t t h a t the t e c h n i cal s t a r t i n g... assembl ies and pa r t s of the a i r c r a f t d~ein the previous flight (R R ), the p r o b a b i l i t y of4pr esence in the landing airport of an...of the assemblies , sets and blocks /P.- can be exchange d in a single hour in case of defects. Furthermore , in the newly constructed L-lOll

Use of magnetic resonance imaging to predict the body composition of pigs in vivo.

PubMed

Kremer, P V; Förster, M; Scholz, A M

2013-06-01

The objective of the study was to evaluate whether magnetic resonance imaging (MRI) offers the opportunity to reliably analyze body composition of pigs in vivo. Therefore, the relation between areas of loin eye muscle and its back fat based on MRI images were used to predict body composition values measured by dual energy X-ray absorptiometry (DXA). During the study, a total of 77 pigs were studied by MRI and DXA, with a BW ranging between 42 and 102 kg. The pigs originated from different extensive or conventional breeds or crossbreds such as Cerdo Iberico, Duroc, German Landrace, German Large White, Hampshire and Pietrain. A Siemens Magnetom Open was used for MRI in the thorax region between 13th and 14th vertebrae in order to measure the loin eye area (MRI-LA) and the above back fat area (MRI-FA) of both body sides, whereas a whole body scan was performed by DXA with a GE Lunar DPX-IQ in order to measure the amount and percentage of fat tissue (DXA-FM; DXA-%FM) and lean tissue mass (DXA-LM; DXA-%LM). A linear single regression analysis was performed to quantify the linear relationships between MRI- and DXA-derived traits. In addition, a stepwise regression procedure was carried out to calculate (multiple) regression equations between MRI and DXA variables (including BW). Single regression analyses showed high relationships between DXA-%FM and MRI-FA (R 2 = 0.89, √MSE = 2.39%), DXA-FM and MRI-FA (R 2 = 0.82, √MSE = 2757 g) and DXA-LM and MRI-LA (R 2 = 0.82, √MSE = 4018 g). Only DXA-%LM and MRI-LA did not show any relationship (R 2 = 0). As a result of the multiple regression analysis, DXA-LM and DXA-FM were both highly related to MRI-LA, MRI-FA and BW (R 2 = 0.96; √MSE = 1784 g, and R 2 = 0.95, √MSE = 1496 g). Therefore, it can be concluded that the use of MRI-derived images provides exact information about important 'carcass-traits' in pigs and may be used to reliably predict the body composition in vivo.

On a class of Newton-like methods for solving nonlinear equations

NASA Astrophysics Data System (ADS)

Argyros, Ioannis K.

2009-06-01

We provide a semilocal convergence analysis for a certain class of Newton-like methods considered also in [I.K. Argyros, A unifying local-semilocal convergence analysis and applications for two-point Newton-like methods in Banach space, J. Math. Anal. Appl. 298 (2004) 374-397; I.K. Argyros, Computational theory of iterative methods, in: C.K. Chui, L. Wuytack (Eds.), Series: Studies in Computational Mathematics, vol. 15, Elsevier Publ. Co, New York, USA, 2007; J.E. Dennis, Toward a unified convergence theory for Newton-like methods, in: L.B. Rall (Ed.), Nonlinear Functional Analysis and Applications, Academic Press, New York, 1971], in order to approximate a locally unique solution of an equation in a Banach space. Using a combination of Lipschitz and center-Lipschitz conditions, instead of only Lipschitz conditions [F.A. Potra, Sharp error bounds for a class of Newton-like methods, Libertas Math. 5 (1985) 71-84], we provide an analysis with the following advantages over the work in [F.A. Potra, Sharp error bounds for a class of Newton-like methods, Libertas Math. 5 (1985) 71-84] which improved the works in [W.E. Bosarge, P.L. Falb, A multipoint method of third order, J. Optimiz. Theory Appl. 4 (1969) 156-166; W.E. Bosarge, P.L. Falb, Infinite dimensional multipoint methods and the solution of two point boundary value problems, Numer. Math. 14 (1970) 264-286; J.E. Dennis, On the Kantorovich hypothesis for Newton's method, SIAM J. Numer. Anal. 6 (3) (1969) 493-507; J.E. Dennis, Toward a unified convergence theory for Newton-like methods, in: L.B. Rall (Ed.), Nonlinear Functional Analysis and Applications, Academic Press, New York, 1971; H.J. Kornstaedt, Ein allgemeiner Konvergenzstaz fü r verschä rfte Newton-Verfahrem, in: ISNM, vol. 28, Birkhaü ser Verlag, Basel and Stuttgart, 1975, pp. 53-69; P. Laasonen, Ein überquadratisch konvergenter iterativer algorithmus, Ann. Acad. Sci. Fenn. Ser I 450 (1969) 1-10; F.A. Potra, On a modified secant method, L'analyse numérique et la theorie de l'approximation 8 (2) (1979) 203-214; F.A. Potra, An application of the induction method of V. Pták to the study of Regula Falsi, Aplikace Matematiky 26 (1981) 111-120; F.A. Potra, On the convergence of a class of Newton-like methods, in: Iterative Solution of Nonlinear Systems of Equations, in: Lecture Notes in Mathematics, vol. 953, Springer-Verlag, New York, 1982; F.A. Potra, V. Pták, Nondiscrete induction and double step secant method, Math. Scand. 46 (1980) 236-250; F.A. Potra, V. Pták, On a class of modified Newton processes, Numer. Funct. Anal. Optim. 2 (1) (1980) 107-120; F.A. Potra, Sharp error bounds for a class of Newton-like methods, Libertas Math. 5 (1985) 71-84; J.W. Schmidt, Untere Fehlerschranken für Regula-Falsi Verfahren, Period. Math. Hungar. 9 (3) (1978) 241-247; J.W. Schmidt, H. Schwetlick, Ableitungsfreie Verfhren mit höherer Konvergenzgeschwindifkeit, Computing 3 (1968) 215-226; J.F. Traub, Iterative Methods for the Solution of Equations, Prentice Hall, Englewood Cliffs, New Jersey, 1964; M.A. Wolfe, Extended iterative methods for the solution of operator equations, Numer. Math. 31 (1978) 153-174]: larger convergence domain and weaker sufficient convergence conditions. Numerical examples further validating the results are also provided.

Delayed injection of polypyrrole doped with iodine particle suspension after spinal cord injury in rats improves functional recovery and decreased tissue damage evaluated by 3.0 Tesla in vivo magnetic resonance imaging.

PubMed

Mondragon-Lozano, Rodrigo; Ríos, Camilo; Roldan-Valadez, Ernesto; Cruz, Guillermo J; Olayo, Maria G; Olayo, Roberto; Salgado-Ceballos, Hermelinda; Morales, Juan; Mendez-Armenta, Marisela; Alvarez-Mejia, Laura; Fabela, Omar; Morales-Guadarrama, Axayacatl; Sánchez-Torres, Stephanie; Diaz-Ruiz, Araceli

2017-04-01

Traumatic spinal cord injury (SCI) causes irreversible damage with loss of motor, sensory, and autonomic functions. Currently, there is not an effective treatment to restore the lost neurologic functions. Injection of polypyrrole-iodine(PPy-I) particle suspension is proposed as a therapeutic strategy. This is an in vivo animal study. This study evaluates the use of such particles in rats after SCI by examining spared nervous tissue and the Basso, Beattie, and Bresnahan (BBB) scale to evaluate the functional outcome. Diffusive magnetic resonance imaging (MRI) was employed to measure the apparent diffusion coefficient (ADC) and fractional anisotropy (FA) as non-invasive biomarkers of damage after SCI. Fractional anisotropy decreased, whereas ADC increased in all groups after the lesion. There were significant differences in FA when compared with the SCI-PPy-I group versus the SCI group (p<.05). Significant positive correlations between BBB and FA (r 2 =0.449, p<.05) and between FA and preserved tissue (r 2 =0.395, p<.05) were observed, whereas significant negative associations between BBB and ADC (r 2 =0.367, p<.05) and between ADC and preserved tissue (r 2 =0.421, p<.05) were observed. The results suggested that PPy-I is neuroprotective as it decreased the amount of damaged tissue while improving the motor function. Non-invasive MRI proved to be useful in the characterization of SCI and recovery. Copyright © 2016 Elsevier Inc. All rights reserved.

A Rapid Method with UPLC for the Determination of Fusaric Acid in Fusarium Strains and Commercial Food and Feed Products.

PubMed

Chen, Zhihong; Luo, Qingqing; Wang, Mingzi; Chen, Bilian

2017-03-01

A rapid, sensitive and validated method for the determination of fusaric acid (FA) in several Fusarium strains and different commercial food and feed products is reported based on ultra-performance liquid chromatography. This method requires only crude sample by a simple extraction with methanol, and requires a very short time of 8 min for completion. Separation of FA was performed at injection volume of 1 μl with a 20:80 (v/v) water/acetonitrile mobile phase containing 0.1 % formic acid at a flow rate of 0.05 ml/min and detected with UV at 220 nm. Nice linearity and good correlation coefficient (R 2  > 0.99) were obtained in the concentration range of 1-200 μg/ml. Validation was demonstrated using blank samples spiked at three different concentrations with standard solution, and the method yielded more than 98.2 % recovery efficiencies and below 2.56 % R.S.D. when applied in the analysis of FA produced by Fusarium verticillioides and a set of transgenic strains of this fungus. Satisfactory recoveries in the range of 79.1-105.8 % and R.S.D lower than 10 % were also obtained for the tested commercial food and feed products. The concentration FA detection in the transgenic strains ranged from 9.65 to 135 μg/kg (0.29-4.05 μg per gram of biomass). However, FA was not detected in most of the commercial products with the exception of niblet, oatmeal, red kidney bean and soybean, for which the concentrations of FA ranged from 2.5 to 18 μg/kg (below the permitted maximum). These results show that the proposed method has a great potential application to analyze FA from different sources rapidly.

Case Study of R-1234yf Refrigerant: Implications for the Framework for Responsible Innovation.

PubMed

Wodzisz, Rafał

2015-12-01

Safety and care for the natural environment are two of the most important values that drive scientific enterprise in twentieth century. Researchers and innovators often develop new technologies aimed at pollution reduction, and therefore satisfy the strive for fulfilment of these values. This work is often incentivized by policy makers. According to EU directive 2006/40/EC on mobile air conditioning since 2013 all newly approved vehicles have to be filled with refrigerant with low global warming potential (GWP). Extensive and expensive research financed by leading car manufacturers led to invention of R-1234yf refrigerant with GWP < 1, which was huge improvement. For the proper understanding of this case it will be useful to refer it to the idea of responsible innovation (RI), which is now being developed and quickly attracts attention. I proceed in the following order. Firstly, I present the relevant properties of R-1234yf and discuss the controversy associated with its marketing. Secondly, I examine framework for responsible innovation. In greater detail I discuss the notions of care for future generations and collective responsibility. Thirdly, I apply the offered framework to the case study at hand. Finally, I draw some conclusions which go in two directions: one is to make some suggestions for improving the framework of RI, and the second is to identify missed opportunities for developing truly responsible refrigerant.

Migration of carbon nanotubes from liquid phase to vapor phase in the refrigerant-based nanofluid pool boiling

PubMed Central

2011-01-01

The migration characteristics of carbon nanotubes from liquid phase to vapor phase in the refrigerant-based nanofluid pool boiling were investigated experimentally. Four types of carbon nanotubes with the outside diameters from 15 to 80 nm and the lengths from 1.5 to 10 μm were used in the experiments. The refrigerants include R113, R141b and n-pentane. The oil concentration is from 0 to 10 wt.%, the heat flux is from 10 to 100 kW·m-2, and the initial liquid-level height is from 1.3 to 3.4 cm. The experimental results indicate that the migration ratio of carbon nanotube increases with the increase of the outside diameter or the length of carbon nanotube. For the fixed type of carbon nanotube, the migration ratio decreases with the increase of the oil concentration or the heat flux, and increases with the increase of the initial liquid-level height. The migration ratio of carbon nanotube increases with the decrease of dynamic viscosity of refrigerant or the increase of liquid phase density of refrigerant. A model for predicting the migration ratio of carbon nanotubes in the refrigerant-based nanofluid pool boiling is proposed, and the predictions agree with 92% of the experimental data within a deviation of ±20%. PMID:21711730

Solubility modeling of refrigerant/lubricant mixtures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Michels, H.H.; Sienel, T.H.

1996-12-31

A general model for predicting the solubility properties of refrigerant/lubricant mixtures has been developed based on applicable theory for the excess Gibbs energy of non-ideal solutions. In our approach, flexible thermodynamic forms are chosen to describe the properties of both the gas and liquid phases of refrigerant/lubricant mixtures. After an extensive study of models for describing non-ideal liquid effects, the Wohl-suffix equations, which have been extensively utilized in the analysis of hydrocarbon mixtures, have been developed into a general form applicable to mixtures where one component is a POE lubricant. In the present study we have analyzed several POEs wheremore » structural and thermophysical property data were available. Data were also collected from several sources on the solubility of refrigerant/lubricant binary pairs. We have developed a computer code (NISC), based on the Wohl model, that predicts dew point or bubble point conditions over a wide range of composition and temperature. Our present analysis covers mixtures containing up to three refrigerant molecules and one lubricant. The present code can be used to analyze the properties of R-410a and R-407c in mixtures with a POE lubricant. Comparisons with other models, such as the Wilson or modified Wilson equations, indicate that the Wohl-suffix equations yield more reliable predictions for HFC/POE mixtures.« less

Culture of common carp (Cyprinus carpio) with defined flesh quality for prevention of cardiovascular diseases using finishing feeding strategy.

PubMed

Mraz, Jan; Zajic, Tomas; Pickova, Jana

2012-01-01

Fish is the major source of n-3 polyunsaturated fatty acids (n-3 PUFA) which are well known to have positive effects in prevention of cardiovascular diseases. This study investigated the possibility to produce common carp with defined flesh quality using finishing feeding strategy and predict changes of fillet FA by a dilution model. During the 110-day experiment, fish were fed diets with two different vegetable oils (rapeseed/linseed blend, VO; olive oil, OO) only, or with a subsequent fish oil (FO) finishing treatment for 30 or 60 days. Fillet FA composition was measured and data were compared to the ones predicted by the dilution model. The FO finishing treatment resulted in the higher percentage of SFA (from 19.1% to 23.6%; p<0.001), MUFA (from 46.8% to 51.9%; p<0.001), n-3 PUFA (from 3.6% to 7.4%; p<0.001) and lower n-6 PUFA (from 30.5% to 16.9%; p<0.001) and n-6/n-3 ratio (from 8.7 to 2.3; p<0.001) in groups previously fed the VO diet and in lower MUFA percentage (from 67% to 63%; p<0.001) and n-6/n-3 ratio (from 8.2 to 2.8; p<0.001) and higher n-3 PUFA percentage (from 1.5% to 4.5%; p<0.001) in group previously fed the OO diet. The dilution model gave a good prediction for fillet FA changes (slope of the regression line 0.97-1.00; R2 value of 0.992-0.996). The finishing feeding strategy is suggested for production of common carp with a required flesh FA composition for purposes of special nutritional needs, especially for primary and secondary prevention of cardiovascular disease.

Transport properties of 1,1-difluoroethane (R152a)

NASA Astrophysics Data System (ADS)

Krauss, R.; Weiss, V. C.; Edison, T. A.; Sengers, J. V.; Stephan, K.

1996-07-01

Based on reliable. carefully selected data sets. equations for the thermal conductivity and the viscosity of the refrigerant R 112a are presented. They are valid at temperatures from 240 to 440 K, pressures up to 20 MPa. and densities up to 1050 kg · m-3. including the critical region.

Transport properties of 1,1-difluoroethane (R152a)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Krauss, R.; Stephan, K.; Weiss, V.C.

1996-07-01

Based on reliable, carefully selected data sets, equations for the thermal conductivity and the viscosity of the refrigerant R152a are presented. They are valid at temperatures from 240 to 440 K, pressures up to 20 MPa, and densities up to 1050 kg {center_dot} m {sup {minus}3}, including the critical region.

Comparison of 1,5-anhydroglucitol, HbA1c, and fructosamine for detection of diabetes mellitus.

PubMed

Yamanouchi, T; Akanuma, Y; Toyota, T; Kuzuya, T; Kawai, T; Kawazu, S; Yoshioka, S; Kanazawa, Y; Ohta, M; Baba, S

1991-01-01

To evaluate the use of serum 1,5-anhydroglucitol (AG) levels in screening for diabetes mellitus, we compared the sensitivity and specificity of HbA1c, fructosamine (FA), and AG in 1620 randomly selected subjects in 11 institutions throughout Japan. Most individuals were receiving diet and/or drug therapy for diabetes. Subjects were separated into four groups based on World Health Organization criteria: nondiabetic control subjects, subjects with impaired glucose tolerance (IGT), patients with diabetes, and patients with other disorders without IGT. The overlap of AG values between each group was less than that of HbA1c or FA values. AG levels were significantly correlated with fasting plasma glucose (r = -0.627), HbA1c (r = -0.629), and FA (r = -0.590) levels. If we took 14 micrograms/ml as the normal lower limit, AG level was highly specific (93.1%), and a decreased AG level indicated diabetes mellitus (84.2% sensitivity). According to the selectivity index (sensitivity value times specificity value), AG determinations were superior to both HbA1c and FA measurements for diabetes screening. When combinations of these tests were used, only AG and HbA1c together were slightly better than AG alone. Thus, together with other advantages of AG, e.g., its wide variance with relatively fair glycemic control and the negligible influence of the sampling conditions, AG level has more potential than HbA1c or FA level as a screening criterion for diabetes.

Local Laser Cooling of Yb:YLF to 110 K

DTIC Science & Technology

2011-09-01

R. I . Epstein, “Optical refrigeration,” Nat. Photonics 1(12), 693–699 (2007). 3. M. Sheik- Bahae and R. I . Epstein, “Laser cooling of solids,” Laser...15. W. M. Patterson, M. Sheik- Bahae , R. I . Epstein, and M. P. Hehlen, “Model of laser-induced temperature changes in solid-state optical...179 (2001). 19. M. P. Hasselbeck, M. Sheik- Bahae , and R. I . Epstein, “Effect of high carrier density on luminescence thermometry in semiconductors

Charge Coupled Devices in Signal Processing Systems. Volume V. Final Report.

DTIC Science & Technology

1979-12-01

the Phase III program. At that time, mutual customer /contractor interest arose in a unique application area, involving manipulation of lists of...using half adders and "or" circuits. 4-35 3 b 2 b3 01 b *3b, *2 b 1 b2b 1 0 1 b, + + + + + + ++ r T 7 7 r* 7FA +-0j FA 147 7 7 1 77 7 7 TL NO.6 NO. 5...which the cell could be step-and- repeated into an array in the CAD system. In practice we found that the attendent custom skewing delay layout

Workplace Trends In HVAC/R

ERIC Educational Resources Information Center

Strang, Lynn; Todd, CeCe

2013-01-01

This article presents trends in the heating, ventilation, air conditioning and refrigeration (HVAC/R) industry, with an emphasis on the importance of technician training programs as exemplified at the East Valley Institute of Technology (EVIT) in Mesa, Arizona. The article states that HVAC workers are increasingly helping their consumers "go…

Aqueous humour dynamics and biometrics in the ageing Chinese eye.

PubMed

Guo, Tao; Sampathkumar, Sruthi; Fan, Shan; Morris, Nathan; Wang, Fang; Toris, Carol B

2017-09-01

This study evaluates ocular biometrics and aqueous humour dynamics (AHD) in healthy Chinese volunteers to determine how the various ocular parameters interact to maintain physiological intraocular pressure (IOP) at all ages. Sixty-nine volunteers enrolled in this cross-sectional study and were categorised into young (20-30 years) and old (≥50 years) groups. Measurements included IOP, ocular biometrics and AHD. Data were analysed using mixed model with random sampling to account for both eyes from the same individual. Spearman's rank correlation with bootstrap resampling was used to find associations between parameters. Compared with young subjects, old subjects had significantly (p<0.05) thinner corneas (CCT; 549.7±5.7 vs 530.6±5.3 µm; mean±SEM), shallower anterior chambers (3.14±0.05 vs 2.37±0.05 mm) and slower aqueous flow (Fa; 3.0±0.1 vs 2.7±0.1 µL/min). Uveoscleral outflow slowed (Fu; 1.0±0.2 vs 0.7±0.1) but not significantly. A positive linear association between IOP and episcleral venous pressure was found (young: R 2 =0.16; old: R 2 =0.08). Negative correlation between Fa and CCT (R 2 =0.06) and positive correlation between Fa and outflow facility (R 2 =0.08) was found in old participants. In the healthy ageing Chinese eye, IOP remains unchanged, while Fa slows, which is counterbalanced by slowing of Fu. Aqueous humour exits the eye preferentially through the trabecular route at all ages. Ageing is also associated with shallowing of the anterior chamber and thinning of the cornea. A slower Fa with lower outflow facility supports existence of autoregulatory mechanisms. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Extending food deprivation reverses the short-term lipolytic response to fasting: role of the triacylglycerol/fatty acid cycle.

PubMed

Weber, Jean-Michel; Reidy, Shannon P

2012-05-01

The effects of short-term food deprivation on lipid metabolism are well documented, but little is known about prolonged fasting. This study monitored the kinetics of glycerol (rate of appearance, R(a) glycerol) and non-esterified fatty acids (R(a) NEFA) in fasting rabbits. Our goals were to determine whether lipolysis is stimulated beyond values seen for short-term fasting, and to characterize the roles of primary (intracellular) and secondary (with transit through the circulation) triacylglycerol/fatty acid cycling (TAG/FA cycling) in regulating fatty acid allocation to oxidation or re-esterification. R(a) glycerol (9.62±0.72 to 15.29±0.96 μmol kg(-1) min(-1)) and R(a) NEFA (18.05±2.55 to 31.25±1.93 μmol kg(-1) min(-1)) were stimulated during the first 2 days of fasting, but returned to baseline after 4 days. An initial increase in TAG/FA cycling was followed by a reduction below baseline after 6 days without food, with primary and secondary cycling contributing to these responses. We conclude that the classic activation of lipolysis caused by short-term fasting is abolished when food deprivation is prolonged. High rates of re-esterification may become impossible to sustain, and TAG/FA cycling could decrease to reduce its cost to 3% of total energy expenditure. Throughout prolonged fasting, fatty acid metabolism gradually shifts towards increased oxidation and reduced re-esterification. Survival is achieved by pressing fuel selection towards the fatty acid dominance of energy metabolism and by slowing substrate cycles to assist metabolic suppression. However, TAG/FA cycling remains active even after prolonged fasting, suggesting that re-esterification is a crucial mechanism that cannot be stopped without harmful consequences.

Formation des etoiles massives dans les galaxies spirales

NASA Astrophysics Data System (ADS)

Lelievre, Mario

Le but de cette thèse est de décrire la formation des étoiles massives dans les galaxies spirales appartenant à divers types morphologiques. L'imagerie Hα profonde combinée à une robuste méthode d'identification des régions HII ont permis de détecter et de mesurer les propriétés (position, taille, luminosité, taux de formation d'étoiles) de plusieurs régions HII situées dans le disque interne (R < R25) de dix galaxies mais aussi à leur périphérie (R ≥ R 25). De façon générale, la répartition des régions HII ne montre aucune évidence de structure morphologique à R < R25 (bras spiraux, anneau, barre) à moins de limiter l'analyse aux régions HII les plus grosses ou les plus lumineuses. La répartition des régions HII, de même que leur taille et leur luminosité, sont toutefois sujettes à de forts effets de sélection qui dépendent de la distance des galaxies et qu'il faut corriger en ramenant l'échantillon à une résolution spatiale commune. Les fonctions de luminosité montrent que les régions HII les plus brillantes ont tendance à se former dans la portion interne du disque. De plus, l'analyse des pentes révèle une forte corrélation linéaire par rapport au type morphologique. Aucun pic n'est observé dans les fonctions de luminosité à log L-37 qui révèlerait la transition entre les régions HII bornées par l'ionisation et par la densité. Une relation cubique est obtenue entre la taille et la luminosité des régions HII, cette relation variant toutefois de façon significative entre le disque interne et la périphérie d'une même galaxie. La densité et la dynamique du gaz et des étoiles pourraient influencer de façon significative la stabilité des nuages moléculaires face à l'effondrement gravitationnel. D'une part, l'étendue du disque de régions HII pour cinq galaxies de l'échantillon coïncide avec celle de l'hydrogène atomique. D'autre part, en analysant la stabilité des disques galactiques, on conclue qu'en incluant la densité des étoiles vieilles présentes, on arrive à mieux contraindre le rayon à partir duquel aucune formation d'étoiles ne devrait se produire dans les galaxies.

Age-related decline in white matter integrity in a mouse model of tauopathy: an in vivo diffusion tensor magnetic resonance imaging study

PubMed Central

Sahara, Naruhiko; Perez, Pablo D.; Lin, Wen-Lang; Dickson, Dennis W.; Ren, Yan; Zeng, Huadong; Lewis, Jada; Febo, Marcelo

2016-01-01

Elevated expression of human hyperphosphorylated tau is associated with neuronal loss and white matter (WM) pathology in Alzheimer’s disease (AD) and related neurodegenerative disorders. Using in vivo diffusion tensor magnetic resonance imaging (DT-MRI) at 11.1 Tesla we measured age-related alterations in WM diffusion anisotropy indices in a mouse model of human tauopathy (rTg4510) and nontransgenic (nonTg) control mice at the age of 2.5, 4.5, and 8 months. Similar to previous DT-MRI studies in AD subjects, 8-month-old rTg4510 mice showed lower fractional anisotropy (FA) values in WM structures than nonTg. The low WM FA in rTg4510 mice was observed in the genu and splenium of the corpus callosum, anterior commissure, fimbria, and internal capsule and was associated with a higher radial diffusivity than nonTg. Interestingly, rTg4510 mice showed lower estimates for the mode of anisotropy than controls at 2.5 months suggesting that changes in this diffusivity metric are detectable at an early stage preceding severe tauopathy. Immunogold electron microscopy partly supports our diffusion tensor imaging findings. At the age of 4 months, rTg4510 mice show axonal tau inclusions and unmyelinated processes. At later ages (12 months and 14 months) we observed inclusions in myelin sheath, axons, and unmyelinated processes, and a “disorganized” pattern of myelinated fiber arrangement with enlarged inter-axonal spaces in rTg4510 but not in nonTg mice. Our data support a role for the progression of tau pathology in reduced WM integrity measured by DT-MRI. Further in vivo DT-MRI studies in the rTg4510 mouse should help better discern the detailed mechanisms of reduced FA and anisotropy mode, and the specific role of tau during neurodegeneration. PMID:24411290

Soft X-Ray Photoemission

DTIC Science & Technology

1977-07-01

Edward R, Hahn/MS-X22 Attn: Donald R. McMorrow/MS-G30 Attn: Samuel R. Crawford/MS-531 Ford Aerospace & Comm Operations Ford & Jamboree Roads...80933 Attn: Jerry I. Lubell Attn: Walter E. Ware Attn: John R. Hoffman Attn: Donald H. Bryce Attn: Albert P. Bridges Litton Systems, Inc...International Corp, P.O. Box 3105 Anaheim, CA 92803 Attn: George C. Messenger FB61 Attn: Donald J, Stevens FA70 Attn: K. F. Hull Attn: N. J

Cholinergic Receptor Binding in Alzheimer Disease and Healthy Aging: Assessment In Vivo with Positron Emission Tomography Imaging.

PubMed

Sultzer, David L; Melrose, Rebecca J; Riskin-Jones, Hannah; Narvaez, Theresa A; Veliz, Joseph; Ando, Timothy K; Juarez, Kevin O; Harwood, Dylan G; Brody, Arthur L; Mandelkern, Mark A

2017-04-01

To compare regional nicotinic cholinergic receptor binding in older adults with Alzheimer disease (AD) and healthy older adults in vivo and to assess relationships between receptor binding and clinical symptoms. Using cross-sectional positron emission tomography (PET) neuroimaging and structured clinical assessment, outpatients with mild to moderate AD (N = 24) and healthy older adults without cognitive complaints (C group; N = 22) were studied. PET imaging of α4β2* nicotinic cholinergic receptor binding using 2-[ 18 F]fluoro-3-(2(S)azetidinylmethoxy)pyridine (2FA) and clinical measures of global cognition, attention/processing speed, verbal memory, visuospatial memory, and neuropsychiatric symptoms were used. 2FA binding was lower in the AD group compared with the C group in the medial thalamus, medial temporal cortex, anterior cingulate, insula/opercula, inferior caudate, and brainstem (p < 0.05, corrected cluster), but binding was not associated with cognition. The C group had significant inverse correlations between 2FA binding in the thalamus (left: r s  = -0.55, p = 0.008; right: r s  = -0.50, p = 0.02; N = 22) and hippocampus (left: r s  = -0.65, p = 0.001; right: r s  = -0.55, p = 0.009; N = 22) and the Trails A score. The AD group had inverse correlation between 2FA binding in anterior cingulate (left: r s  = -0.50, p = 0.01; right: r s  = -0.50, p = 0.01; N = 24) and Neurobehavioral Rating Scale agitation/disinhibition factor score. Cholinergic receptor binding is reduced in specific brain regions in mild to moderate AD and is related to neuropsychiatric symptoms. Among healthy older adults, lower receptor binding may be associated with slower processing speed. Cholinergic receptor binding in vivo may reveal links to other key brain changes associated with aging and AD and may provide a potential molecular treatment target. Published by Elsevier Inc.

Polyunsaturated fatty acids effect on serum triglycerides concentration in presence of metabolic syndrome components. The Alaska-Siberia Project

PubMed Central

Lopez-Alvarenga, Juan C.; Ebbesson, Sven O E; Ebbesson, Lars O E; Tejero, M Elizabeth; Voruganti, V. Saroja; Comuzzie, Anthony G

2009-01-01

Serum fatty acids (FA) have wide effects on metabolism: Serum saturated fatty acids (SFA) increase triglyceride (TG) levels in plasma while polyunsaturated fatty acids (PUFA) reduce them. Traditionally, Eskimos have a high consumption of omega -3 fatty acids (ω–3 FA), but the westernization of their food habits have increased their dietary SFAs, partly reflected in their serum concentrations. We studied the joint effect of serum SFAs and PUFAs on circulating levels of TG in the presence of metabolic syndrome components. We included 212 men and 240 women (age 47.9±15.7 y, BMI 26.9±5.3) from four villages located in Alaska for a cross sectional study. Generalized linear models were employed to build surface responses of TG as in functions of SFAs and PUFAs measured in blood samples adjusting by sex, BMI and village. The effects of individual FAs were assessed by multiple linear regression analysis and partial correlations (r) were calculated. The most important predictors for TG levels were glucose tolerance (r = 0.116, p = 0.018) and BMI (r = 0.42, p<0.001). TG concentration showed negative associations with 20:3ω-6 (r =− 0.16, p = 0.001), 20:4ω-6 (r = −0.14, p=0.005), 20:5ω-3 (r = −0.17, p<0.001) and 22:5ω-3 (r = −0.26, p<0.001), and positive associations with palmitic acid (r = 0.16, p<0.001) and 18:3ω-3 (r = 0.15, p<0.001). The surface response analysis suggested that the effect of palmitic acid on TG is blunted in different degrees according to the PUFA chemical structure. The long chain ω-3, even in presence of high levels of SF, was associated with lower triglyceride levels. Eicosapentanoic acid (20:5ω3) had the strongest effect against palmitic acid on TG. The total FA showed moderate association with levels of TG, while SFA was positively associated, and large chain PUFA negatively. The westernized dietary habits among Eskimos are likely to change their metabolic profile and increase comorbidities related to metabolic disease. PMID:19766268

Decreased nicotinic receptor availability in smokers with slow rates of nicotine metabolism

PubMed Central

Dubroff, Jacob G.; Doot, Robert K.; Falcone, Mary; R, Robert A. Schnoll; Ray, Riju; Tyndale, Rachel F.; Brody, Arthur L.; Hou, Catherine; Schmitz, Alexander; Lerman, Caryn

2015-01-01

The nicotine metabolite ratio (NMR), a stable measure of hepatic nicotine metabolism via the CYP2A6 pathway and total nicotine clearance, is a predictive biomarker of response to nicotine replacement therapy, with increased quit rates in slower metabolizers. Nicotine binds directly to nicotinic acetylcholine receptors (nAChRs) to exert its psychoactive effects. This study examined the relationship between NMR and nAChR availability (α4β2* subtype) using positron emission tomography (PET) imaging of the radiotracer 2-18F-FA-85380 (2-18F-FA). Methods Twenty four smokers, 12 slow metabolizers (NMR <0.26) and 12 normal metabolizers (NMR ≥0.26), underwent 2-18F-FA-PET brain imaging following overnight nicotine abstinence (18 hours prior to scanning), using a validated bolus plus infusion protocol. Availability of nAChRs was compared between NMR groups in a priori volumes of interest (VOIs), with total distribution volume (VT/fP) being the measure of nAChR availability. Cravings to smoke were assessed prior to and following the scans. Results Thalamic nAChR α4β2* availability was significantly reduced in slow (versus normal) nicotine metabolizers (P=0.04). Slow metabolizers exhibited greater reductions in craving than normal metabolizers from pre- to post-scanning; however, craving was unrelated to availability. Conclusion The rate of nicotine metabolism is associated with thalamic nAChR availability. Additional studies could examine whether altered nAChR availability underlies differences in treatment response between slow and normal metabolizers of nicotine. PMID:26272810

76 FR 28123 - Notice of Passenger Facility Charge (PFC) Approvals and Disapprovals

Federal Register 2010, 2011, 2012, 2013, 2014

2011-05-13

... for Collection and Use: Design/construct passenger terminal and land/airside. PFC application... Level: Runway 16L/34R pavement rehabilitation. Concourse B--additional boarding bridges. North cargo... 16R134L. Joint seal runway 16R/34L--taxiways A and B. [[Page 28124

Effect of fly ash on properties of crushed brick and reclaimed asphalt in pavement base/subbase applications.

PubMed

Mohammadinia, Alireza; Arulrajah, Arul; Horpibulsuk, Suksun; Chinkulkijniwat, Avirut

2017-01-05

Fly Ash (FA), an abundant by-product with no carbon footprint, is a potential stabilizer for enhancing the physical and geotechnical properties of pavement aggregates. In this research, FA was used in different ratios to stabilize crushed brick (CB) and reclaimed asphalt pavement (RAP) for pavement base/subbase applications. The FA stabilization of CB and RAP was targeted to improve the strength and durability of these recycled materials for pavement base/subbase applications. The Unconfined Compressive Strength (UCS) and resilient modulus (M R ) development of the stabilized CB and RAP aggregates was studied under room temperature and at an elevated temperatures of 40°C, and results compared with unbound CB and RAP. Analysis of atomic silica content showed that when the amount of silica and alumina crystalline was increased, the soil structure matrix deteriorated, resulting in strength reduction. The results of UCS and M R testing of FA stabilized CB and RAP aggregates indicated that FA was a viable binder for the stabilization of recycled CB and RAP. CB and RAP stabilized with 15% FA showed the highest UCS results at both room temperature and at 40°C. Higher temperature curing was also found to result in higher strengths. Copyright © 2016 Elsevier B.V. All rights reserved.

The Fanconi anemia protein interaction network: casting a wide net.

PubMed

Rego, Meghan A; Kolling, Frederick W; Howlett, Niall G

2009-07-31

It has long been hypothesized that a defect in the repair of damaged DNA is central to the etiology of Fanconi anemia (FA). Indeed, an increased sensitivity of FA patient-derived cells to the lethal effects of various forms of DNA damaging agents was described over three decades ago [A.J. Fornace, Jr., J.B. Little, R.R. Weichselbaum, DNA repair in a Fanconi's anemia fibroblast cell strain, Biochim. Biophys. Acta 561 (1979) 99-109; Y. Fujiwara, M. Tatsumi, Repair of mitomycin C damage to DNA in mammalian cells and its impairment in Fanconi's anemia cells, Biochem. Biophys. Res. Commun. 66 (1975) 592-598; A.J. Rainbow, M. Howes, Defective repair of ultraviolet- and gamma-ray-damaged DNA in Fanconi's anaemia, Int. J. Radiat. Biol. Relat. Stud. Phys. Chem. Med. 31 (1977) 191-195]. Furthermore, the cytological hallmark of FA, the DNA crosslink-induced radial chromosome formation, exemplifies an innate impairment in the repair of these particularly cytotoxic DNA lesions [A.D. Auerbach, Fanconi anemia diagnosis and the diepoxybutane (DEB) test, Exp. Hematol. 21 (1993) 731-733]. Precisely defining the collective role of the FA proteins in DNA repair, however, continues to be one of the most enigmatic and challenging questions in the FA field. The first six identified FA proteins (A, C, E, F, G, and D2) harbored no recognizable enzymatic features, precluding association with a specific metabolic process. Consequently, our knowledge of the role of the FA proteins in the DNA damage response has been gleaned primarily through biochemical association studies with non-FA proteins. Here, we provide a chronological discourse of the major FA protein interaction network discoveries, with particular emphasis on the DNA damage response, that have defined our current understanding of the molecular basis of FA.

Optical Turbulence Measurement - Investigations for Analysis of Laser Designator Spot Patterns.

DTIC Science & Technology

1983-05-01

34,R,-SQCN,Q,-EXT COEF",E,-AVLNGTH-,W,"OBJ LZ NS",O 120: ent "OBS/OBJ",B," SCALL ",rll;sprt 6,R,Q,E,rJ,O,j3,r11 121: OSYSTEM DATA-Ii-eAVLNTki IN AETERS O...bars in the grating, and the wavelength cf the iser i_-e knDwn, -he scale factor 7an be calculated from the relation sia (theta) = A/d (3. 1) sia ...cos (P*r) If INVERSEFXFOR3 = True then F ;7<== 1 76 FA;7<== 0 End If P<== sia (P*r) *(1-2*Flg7) Do f~r r = 2*R0*I~l to 2*RO*3+RO Rl<== RDArk(II R2

Engraftment and bone mass are enhanced by PTHrP 1-34 in ectopically transplanted vertebrae (vossicle model) and can be non-invasively monitored with bioluminescence and fluorescence imaging.

PubMed

Hildreth, Blake Eason; Williams, Michelle M; Dembek, Katarzyna A; Hernon, Krista M; Rosol, Thomas J; Toribio, Ramiro E

2015-12-01

Evidence exists that parathyroid hormone-related protein (PTHrP) 1-34 may be more anabolic in bone than parathyroid hormone 1-34. While optical imaging is growing in popularity, scant information exists on the relationships between traditional bone imaging and histology and bioluminescence (BLI) and fluorescence (FLI) imaging. We aimed to evaluate the effects of PTHrP 1-34 on bone mass and determine if relationships existed between radiographic and histologic findings in bone and BLI and FLI indices. Vertebrae (vossicles) from mice coexpressing luciferase and green fluorescent protein were implanted subcutaneously into allogenic nude mice. Transplant recipients were treated daily with saline or PTHrP 1-34 for 4 weeks. BLI, FLI, radiography, histology, and µCT of the vossicles were performed over time. PTHrP 1-34 increased bioluminescence the most after 2 weeks, fluorescence at all time points, and decreased the time to peak bioluminescence at 4 weeks (P ≤ 0.027), the latter of which suggesting enhanced engraftment. PTHrP 1-34 maximized vertebral body volume at 4 weeks (P < 0.0001). The total amount of bone observed histologically increased in both groups at 2 and 4 weeks (P ≤ 0.002); however, PTHrP 1-34 exceeded time-matched controls (P ≤ 0.044). A positive linear relationship existed between the percentage of trabecular bone and (1) total bioluminescence (r = 0.595; P = 0.019); (2) total fluorescence (r = 0.474; P = 0.074); and (3) max fluorescence (r = 0.587; P = 0.021). In conclusion, PTHrP 1-34 enhances engraftment and bone mass, which can be monitored non-invasively by BLI and FLI.

Circulating profiling reveals the effect of a polyunsaturated fatty acid-enriched diet on common microRNAs.

PubMed

Ortega, Francisco J; Cardona-Alvarado, Mónica I; Mercader, Josep M; Moreno-Navarrete, José M; Moreno, María; Sabater, Mònica; Fuentes-Batllevell, Núria; Ramírez-Chávez, Enrique; Ricart, Wifredo; Molina-Torres, Jorge; Pérez-Luque, Elva L; Fernández-Real, José M

2015-10-01

Consumption of long-chain polyunsaturated fatty acids (PUFAs), which are abundant in seafood and nuts, ameliorates components of the metabolic syndrome. Circulating microRNAs (miRNAs) have demonstrated to be valuable biomarkers of metabolic diseases. Here, we investigated whether a sustained nuts-enriched diet can lead to changes in circulating miRNAs, in parallel to the dietary modification of fatty acids (FAs). The profile of 192 common miRNAs was assessed (TaqMan low-density arrays) in plasma from 10 healthy women before and after an 8-week trial with a normocaloric diet enriched with PUFAs (30 g/day of almonds and walnuts). The most relevant miRNAs were validated in an extended sample of 30 participants (8 men and 22 women). Adiponectin was measured by immunoassay and FAs by gas liquid chromatography coupled to mass spectrometry. The percentage of both ω-3 (P=.01) and ω-6 (P=.029) PUFAs of dietary origin (as inferred from plasma FA concentrations) increased, whereas saturated FAs decreased (P=.0008). Concomitantly with changes in circulating FAs, several miRNAs were modified by treatment, including decreased miR-328, miR-330-3p, miR-221 and miR-125a-5p, and increased miR-192, miR-486-5p, miR-19b, miR-106a, miR-769-5p, miR-130b and miR-18a. Interestingly, miR-106a variations in plasma correlated with changes in PUFAs, while miR-130b (r=0.58, P=.003) and miR-221 (r=0.46, P=.03) reflected changes in C-reactive protein. The dietary modulation of miR-125a-5p mirrored changes in fasting triglycerides (r=-0.44, P=.019) and increased adiponectin (r=0.43, P=.026). Dietary FAs (as inferred from plasma FA concentration) are linked to changes in circulating miRNAs, which may be modified by a PUFAs-enriched diet. Copyright © 2015. Published by Elsevier Inc.

Diffusion Tensor Fractional Anisotropy in the Superior Longitudinal Fasciculus Correlates with Functional Independence Measure Cognition Scores in Patients with Cerebral Infarction.

PubMed

Koyama, Tetsuo; Domen, Kazuhisa

2017-08-01

This study aimed to determine the relationship between fiber tract degeneration measured by diffusion-tensor imaging (DTI) and outcome of patients after cerebral infarction. Fractional anisotropy (FA) maps were generated by DTI in patients 14-21 days after the first infarction and were analyzed by tract-based spatial statistics (TBSS). Mean FA values within the corticospinal tract (CST) and the superior longitudinal fasciculus (SLF) were extracted from individual TBSS data. Relationships between FA ratios (rFAs, lesioned to non-lesioned hemisphere) and outcomes assessed by Brunnstrom stage (BRS) and Functional Independence Measure (FIM) motor and cognition scores were examined using Spearman's rank correlation test. Forty patients (21 left and 19 right hemisphere lesions) were entered into an analytical database. BRS ranged from 1 to 6 (median, 5) for shoulder, elbow, or forearm; from 2 to 6 (median, 4.5) for hand or finger; and from 3 to 6 (median, 5) for lower extremity. FIM motor ranged from 51 to 91 (median, 79.5), and FIM cognition ranged from 16 to 35 (median, 29). rFA values in the CST ranged from .692 to 1.053 (median, .933), and those in the SLF ranged from .778 to 1.076 (median, .965). Mann-Whitney U test (P <.05) revealed no significant differences between the left and the right hemisphere lesion groups. Individual rFA values in the CST correlated with BRS scores (r = .585-0.654), whereas those in the SLF correlated with FIM cognition scores (r = .409, P <.05). DTI-FA values in the SLF and CST may be useful for outcome prediction of cognitive function and extremity function, respectively. Copyright © 2017 National Stroke Association. Published by Elsevier Inc. All rights reserved.

State Skill Standards: Heating, Ventilation, Air Conditioning, and Refrigeration

ERIC Educational Resources Information Center

Ball, Larry; Soukup, Dennis

2006-01-01

The Department of Education has undertaken an ambitious effort to develop statewide career and technical education skill standards. The standards in this document are for Heating, Ventilation, Air Conditioning and Refrigeration (HVAC&R) programs and are designed to clearly state what the student should know and be able to do upon completion of…

Etiology and Rapid Diagnosis of Human Viral Gastroenteritis

DTIC Science & Technology

1989-05-01

Esherichia coli infections detected by DNA hybridization. Journal of Clinical Microbiology 26:1362-1366,1988. 16. Herrmann, J.E., Blacklow, N.R., Perron... coli infections in pediatric diarrhea in the Philippines, J. Infect. Dis. 138:326, 1978. 13. Echeverria, P., Hodge, F.A., Blacklow, N.R., Vollet, J.J

Response to comment on "Environmental fate of the next generation refrigerant 2,3,3,3-tetrafluoropropene (HFO-1234yf)

DOE PAGES

Im, Jeongdae; Walshe-Langford, Gillian E.; Moon, Ji Won; ...

2015-06-11

In this study, refrigerant 2,3,3,3-tetrafluoropropene (HFO-1234yf) has been developed for use in mobile air conditioning systems to replace 1,1,1,2-tetrafluoroethane (HFC-134a), which has a much greater global warming potential.

O6.5. LINKING CORTICAL AND CONNECTIONAL PATHOLOGY IN SCHIZOPHRENIA

PubMed Central

Di Biase, Maria; Cropley, Vanessa; Cocchi, Luca; Fornito, Alexander; Calamante, Fernando; Ganella, Eleni; Pantelis, Christos; Zalesky, Andrew

2018-01-01

Abstract Background Schizophrenia is associated with cortical thinning and breakdown in white matter microstructure. Whether these pathological processes are related remains unclear. We used multimodal neuroimaging to investigate the relation between regional cortical thinning and breakdown in adjacent infracortical white matter as a function of age and illness duration. Methods Structural magnetic resonance and diffusion images were acquired in 218 schizophrenia patients and 167 age-matched healthy controls to map cortical thickness (CT) and fractional anisotropy (FA) in regionally adjacent infracortical white matter at various cortical depths. Results Between-group differences in CT and infracortical FA were inversely correlated across cortical regions (r=−0.5, p<0.0001), such that the most anisotropic infracortical white matter was found adjacent to regions with extensive cortical thinning. This pattern was evident in early (20 years: r=−0.3, p=0.005) and middle life (30 years: r=−0.4, p=0.004, 40 years: r=−0.3, p=0.04), but not beyond 50 years (p>0.05). Frontal pathology contributed most to this pattern, with extensive cortical thinning in patients compared to controls at all ages (p<0.05); in contrast to initially increased frontal infracortical FA in patients at 30 years, followed by rapid decline in frontal FA with age (rate of annual decline; patients: 0.0012, controls 0.0006, p<0.001). Discussion Cortical thinning and breakdown in white matter anisotropy are inversely related in young schizophrenia patients, with abnormally elevated white matter myelination found adjacent to frontal regions with extensive cortical thinning. We argue that elevated frontal anisotropy reflects regionally-specific, compensatory responses to cortical thinning, which are eventually overwhelmed with increasing illness duration.

A comparative study on the environmental impact of supermarket refrigeration systems using low GWP refrigerants

DOE Office of Scientific and Technical Information (OSTI.GOV)

Beshr, M.; Aute, V.; Sharma, V.

Supermarket refrigeration systems have high environmental impact due to their large refrigerant charge and high leak rates. Consequently, the interest in using low GWP refrigerants such as carbon dioxide (CO 2) and new refrigerant blends is increasing. In this study, an open-source Life Cycle Climate Performance (LCCP) framework is presented and used to compare the environmental impact of four supermarket refrigeration systems: a transcritical CO 2 booster system, a cascade CO 2/N-40 system, a combined secondary circuit with central DX N-40/L-40 system, and a baseline multiplex direct expansion system utilizing R-404A and N-40. The study is performed for different climatesmore » within the USA using EnergyPlus to simulate the systems' hourly performance. Finally, further analyses are presented such as parametric, sensitivity, and uncertainty analyses to study the impact of different system parameters on the LCCP.« less

A comparative study on the environmental impact of supermarket refrigeration systems using low GWP refrigerants

DOE PAGES

Beshr, M.; Aute, V.; Sharma, V.; ...

2015-04-09

Supermarket refrigeration systems have high environmental impact due to their large refrigerant charge and high leak rates. Consequently, the interest in using low GWP refrigerants such as carbon dioxide (CO 2) and new refrigerant blends is increasing. In this study, an open-source Life Cycle Climate Performance (LCCP) framework is presented and used to compare the environmental impact of four supermarket refrigeration systems: a transcritical CO 2 booster system, a cascade CO 2/N-40 system, a combined secondary circuit with central DX N-40/L-40 system, and a baseline multiplex direct expansion system utilizing R-404A and N-40. The study is performed for different climatesmore » within the USA using EnergyPlus to simulate the systems' hourly performance. Finally, further analyses are presented such as parametric, sensitivity, and uncertainty analyses to study the impact of different system parameters on the LCCP.« less

Low GWP Refrigerants Modelling Study for a Room Air Conditioner Having Microchannel Heat Exchangers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shen, Bo; Bhandari, Mahabir S

Microchannel heat exchangers (MHX) have found great successes in residential and commercial air conditioning applications, being compact heat exchangers, to reduce refrigerant charge and material cost. This investigation aims to extend the application of MHXs in split, room air conditioners (RAC), per fundamental heat exchanger and system modelling. For this paper, microchannel condenser and evaporator models were developed, using a segment-to-segment modelling approach. The microchannel heat exchanger models were integrated to a system design model. The system model is able to predict the performance indices, such as cooling capacity, efficiency, sensible heat ratio, etc. Using the calibrated system and heatmore » exchanger models, we evaluated numerous low GWP (global warming potential) refrigerants. The predicted system performance indices, e.g. cooling efficiency, compressor discharge temperature, and required compressor displacement volume etc., are compared. Suitable replacements for R22 and R-410A for the room air conditioner application are recommended.« less

A Cultural Assessment of the Archeological Resources in the Keystone Lake Project Area, North-Central Oklahoma.

DTIC Science & Technology

1980-01-01

CHAPTER 1. INTRODUCTION...... ....... . . . .. .. .... by Bruce M. Moore PART I. BACKGROUND CHAPTER 2. ENVIRONMENTAL SETTING...Area Inundation Impacts .. .. .... 235 Environmental Matrices Variable. .. .. . . ..... 236 Reservoir Dynamics Variable. .. ... .. ...... 236rCultural...susceptibility to erosional processes. PART I. BACKGROUND a- I CHAPTER 2 ENVIRONMENTAL SETTING Keystone Lake was formed by impounding the Arkansas and Cimarron

A review of overgeneral memory in child psychopathology.

PubMed

Hitchcock, Caitlin; Nixon, Reginald D V; Weber, Nathan

2014-06-01

Overgeneral autobiographical memory (OGM) refers to the impaired retrieval of specific events from autobiographical memory. This review examined OGM in children and adolescents to answer three main questions. First, do children demonstrate OGM? Second, how does the experience of OGM relate to childhood trauma and associated psychopathology? Third, is the CaR-FA-X model (Williams et al., 2007) able to explain OGM in child psychopathology once developmental issues have been considered? Articles were identified in PsycINFO and PubMed searches using the terms overgeneral memory AND children, autobiographical memory specificity AND children, and autobiographical memory AND children. The authors reviewed 21 articles that examined OGM in young people aged 7–18 years. Effect sizes were calculated for each study. The review demonstrated consistent support for a relationship with trauma exposure and depression symptoms in childhood. Furthermore, OGM was found to predict depression symptoms. Limited support was provided for the efficacy of the CaR-FA-X model in young people. Future research will need to examine the influence of trauma characteristics on OGM development, along with the relationship of OGM to depression prognosis. Further investigation of the CaR-FA-X model is required and developmental aspects will need to be taken into account.

Detecting Hidden Communications Protocols

DTIC Science & Technology

2013-02-11

Protocols FA9550-09-1-0173 Richard R Brooks Clemson University PO Box 340915 Clemson, SC 29634-0915 Air Force Office of Scientific Research/RSL 875...two botnet detection methods: centralized botnet traffic detection using HMMs and probabilistic context-free grammars (PCFGs) for centralized and...final report for the Detecting Hidden Communications Protocols AFOSR grant with R. R. Brooks form Clemson University as PI. The work funded by the

Measurement of Solid-State Optical Refrigeration by Two-Band Differential Luminescence Thermometry

DTIC Science & Technology

2010-03-01

Bahae ,1 R. I . Epstein,2 and M. P. Hehlen2 1The University of New Mexico, 800 Yale Boulevard Northeast, Albuquerque, New Mexico 87131, USA 2Los Alamos...Solids, R. I . Epstein and M. Sheik- Bahae , eds. (Wiley, 2009), pp. 33–68. 3. W. M. Patterson, M. P. Hehlen, R. I . Epstein, and M. Sheik- Bahae ...M. Sheik- Bahae , R. I . Epstein, S. Bigotta, and M. Tonelli, “Cooling of Yb:YLF using cavity enhanced resonant absorption,” Proc. SPIE 6907, 69070B

Characterization of the indigenous microflora in raw and pasteurized buffalo milk during storage at refrigeration temperature by high-throughput sequencing

USDA-ARS?s Scientific Manuscript database

The effect of refrigeration on bacterial communities within raw and pasteurized buffalo milk was studied using high-throughput sequencing. High quality samples of raw buffalo milk were obtained from five dairy farms in the Guangxi province of China. A sample of each milk was pasteurized, and both r...

A Comparative Study on the Environmental Impact of CO2 Supermarket Refrigeration Systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Beshr, Mohamed; Aute, Vikrant; Sharma, Vishaldeep

Supermarket refrigeration systems have high environmental impact due to their large refrigerant charge and high leak rates. Accordingly, the interest in using natural refrigerants, such as carbon dioxide (CO2), and new refrigerant blends with low GWP in such systems is increasing. In this paper, an open-source Life Cycle Climate Performance (LCCP) framework is presented and used to compare the environmental impact of three supermarket refrigeration systems. These systems include a transcritical CO2 booster system, a cascade CO2/N-40 system, and a baseline R-404A multiplex direct expansion system. The study is performed for cities representing different climates within the USA using EnergyPlusmore » to simulate the systems' hourly performance. Finally, a parametric analysis is performed to study the impact of annual leak rate on the systems' LCCP.« less

Bayesian regression models outperform partial least squares methods for predicting milk components and technological properties using infrared spectral data

PubMed Central

Ferragina, A.; de los Campos, G.; Vazquez, A. I.; Cecchinato, A.; Bittante, G.

2017-01-01

The aim of this study was to assess the performance of Bayesian models commonly used for genomic selection to predict “difficult-to-predict” dairy traits, such as milk fatty acid (FA) expressed as percentage of total fatty acids, and technological properties, such as fresh cheese yield and protein recovery, using Fourier-transform infrared (FTIR) spectral data. Our main hypothesis was that Bayesian models that can estimate shrinkage and perform variable selection may improve our ability to predict FA traits and technological traits above and beyond what can be achieved using the current calibration models (e.g., partial least squares, PLS). To this end, we assessed a series of Bayesian methods and compared their prediction performance with that of PLS. The comparison between models was done using the same sets of data (i.e., same samples, same variability, same spectral treatment) for each trait. Data consisted of 1,264 individual milk samples collected from Brown Swiss cows for which gas chromatographic FA composition, milk coagulation properties, and cheese-yield traits were available. For each sample, 2 spectra in the infrared region from 5,011 to 925 cm−1 were available and averaged before data analysis. Three Bayesian models: Bayesian ridge regression (Bayes RR), Bayes A, and Bayes B, and 2 reference models: PLS and modified PLS (MPLS) procedures, were used to calibrate equations for each of the traits. The Bayesian models used were implemented in the R package BGLR (http://cran.r-project.org/web/packages/BGLR/index.html), whereas the PLS and MPLS were those implemented in the WinISI II software (Infrasoft International LLC, State College, PA). Prediction accuracy was estimated for each trait and model using 25 replicates of a training-testing validation procedure. Compared with PLS, which is currently the most widely used calibration method, MPLS and the 3 Bayesian methods showed significantly greater prediction accuracy. Accuracy increased in moving from calibration to external validation methods, and in moving from PLS and MPLS to Bayesian methods, particularly Bayes A and Bayes B. The maximum R2 value of validation was obtained with Bayes B and Bayes A. For the FA, C10:0 (% of each FA on total FA basis) had the highest R2 (0.75, achieved with Bayes A and Bayes B), and among the technological traits, fresh cheese yield R2 of 0.82 (achieved with Bayes B). These 2 methods have proven to be useful instruments in shrinking and selecting very informative wavelengths and inferring the structure and functions of the analyzed traits. We conclude that Bayesian models are powerful tools for deriving calibration equations, and, importantly, these equations can be easily developed using existing open-source software. As part of our study, we provide scripts based on the open source R software BGLR, which can be used to train customized prediction equations for other traits or populations. PMID:26387015

Analysis of the influence of advanced materials for aerospace products R&D and manufacturing cost

NASA Astrophysics Data System (ADS)

Shen, A. W.; Guo, J. L.; Wang, Z. J.

2015-12-01

In this paper, we pointed out the deficiency of traditional cost estimation model about aerospace products Research & Development (R&D) and manufacturing based on analyzing the widely use of advanced materials in aviation products. Then we put up with the estimating formulas of cost factor, which representing the influences of advanced materials on the labor cost rate and manufacturing materials cost rate. The values ranges of the common advanced materials such as composite materials, titanium alloy are present in the labor and materials two aspects. Finally, we estimate the R&D and manufacturing cost of F/A-18, F/A- 22, B-1B and B-2 aircraft based on the common DAPCA IV model and the modified model proposed by this paper. The calculation results show that the calculation precision improved greatly by the proposed method which considering advanced materials. So we can know the proposed method is scientific and reasonable.

Pesticides in Ground Water Database A Compilation of ...

EPA Pesticide Factsheets

... t •-; i.j'ic? ... c-.ji ¦$ t.-e : -c* ., ~ . j «-3 jra ctrc $f*a :"^;i •fct-Of* of "¦*'Z""*Jt'C^ >?r3 ,i,:d,:-rj ss^/Ci' ~ ..t • i ¦ .2'iir4 \\'s ' ' • r; "• s .vnr *¦<;>p ica ^ •••* ...

High pressure adsorption isotherms of nitrogen onto granular activated carbon for a single bed pressure swing adsorption refrigeration system

NASA Astrophysics Data System (ADS)

Palodkar, Avinash V.; Anupam, Kumar; Roy, Zunipa; Saha, B. B.; Halder, G. N.

2017-10-01

Adsorption characteristics of nitrogen onto granular activated carbon for the wide range of temperature (303-323 K) and pressure (0.2027-2.0265 MPa) have been reported for a single bed pressure swing adsorption refrigeration system. The experimental data were fitted to Langmuir, Dubinin-Astakhov and Dubinin-Radushkevich (D-R) isotherms. The Langmuir and D-R isotherm models were found appropriate in correlating experimental adsorption data with an average relative error of ±2.0541% and ±0.6659% respectively. The isosteric heat of adsorption data were estimated as a function of surface coverage of nitrogen and temperature using D-R isotherm. The heat of adsorption was observed to decrease from 12.65 to 6.98 kJ.mol-1 with an increase in surface concentration at 303 K and it followed the same pattern for other temperatures. It was found that an increase in temperature enhances the magnitude of the heat of adsorption.

Determination of properties of PVE lubricants with HFC refrigerants[PolyVinylEther

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kaneko, Masato; Sakanoue, Shuichi; Tazaki, Toshihiro

1999-07-01

Polyalkyleneglycol (PAG) and polyol ester (POE) have been developed as refrigeration lubricants, used with HFC134a. PAG is used for automotive air conditioning systems and POE is used for domestic reciprocating refrigerators and for A/C systems. Although PAG exhibits good lubricity performance, it is difficult to use for domestic reciprocating refrigerators due to its low dielectric property. POE is difficult to use for automotive A/C systems, due to hydrolysis and poor lubricity performance. Polyvinylether (PVE) can be used in place of PAG and POE with HFC refrigerants. PVE is used for A/C systems as well as refrigerator and freezer applications. PVEmore » is an ideal lubricant for use with HFCs.« less

Editor’s Highlight: Lower Fractional Anisotropy in the Globus Pallidus of Asymptomatic Welders, a Marker for Long-Term Welding Exposure

PubMed Central

Lee, Eun-Young; Flynn, Michael R.; Du, Guangwei; Lewis, Mechelle M.; Herring, Amy H.; Van Buren, Eric; Van Buren, Scott; Kong, Lan; Mailman, Richard B.; Huang, Xuemei

2016-01-01

Introduction: Welding fumes contain several metals including manganese (Mn), iron (Fe), and copper (Cu) that at high exposure may co-influence welding-related neurotoxicity. The relationship between brain accumulation of these metals and neuropathology, especially in welders with subclinical exposure levels, is unclear. This study examined the microstructural integrity of basal ganglia (BG) regions in asymptomatic welders using diffusion tensor imaging (DTI). Methods: Subjects with (n = 43) and without (age- and gender-matched controls; n = 31) history of welding were studied. Occupational questionnaires estimated short-term (HrsW; welding hours and E90; cumulative exposure, past 90 days) and long-term (YrsW; total years welding and ELT; cumulative exposure, lifetime) exposure. Whole blood metal levels (Mn, Fe, and Cu) were obtained. Brain MRI pallidal index (PI), R1 (1/T1), and R2* (1/T2*) were measured to estimate Mn and Fe accumulation in BG [caudate, putamen, and globus pallidus (GP)]. DTI was used to assess BG microstructural differences, and related with exposure measurements. Results: When compared with controls, welders had significantly lower fractional anisotropy (FA) in the GP. In welders, GP FA values showed non-linear relationships to YrsW, blood Mn, and PI. GP FA decreased after a critical level of YrsW or Mn was reached, whereas it decreased with increasing PI values until plateauing at the highest PI values. GP FA, however, did not show any relationship with short-term exposure measurements (HrsW, E90), blood Cu and Fe, or R2* values. Conclusion: GP FA captured microstructural changes associated with chronic low-level Mn exposure, and may serve as a biomarker for neurotoxicity in asymptomatic welders. PMID:27466214

High Resolution Satellite Observations of Mesoscale Oceanography in the Tasman Sea 1978-79.

DTIC Science & Technology

1982-02-01

c:TATI!S clS (); 11 "AP ) -q I-Tj4LS IF t H~FI~fO~InPO T64TC. 4nOA AOF (.IVFt, IN THP~ r14TA L1cTc. "offre FQQ1" VS T-W PIFFF,.l4Cj(F (mmfh1P 1 5 fi ~~S 1...8217;’IF P. 1"AOTI ToS T 41 APPAQFA’YT IJMI- rTO -ANC’F T$:NP;:-ATIPFh𔃻 OF T"F S1t)FAcVI- *ATtP PS PEFTFPMNtFr- FP0k’ THF rCOT ImA(F (frSU’Os T- ŕ TATrS...2r 0?79 -381$ 1495? 305-034&)0-? 1 A GnQlSFC 20 -30 9 115 NIJMQFP OF TAGFS PPIOPITY P, GPO )IIP(3) = 43 NIIMRFP OF TMAGFS PPIOPITY H= 26A TOTAI

Improvements for energy conservation at the Coeur d'Alene Nursery

Treesearch

Aram Eramian

2009-01-01

In 2002, the USDA Forest Service Coeur d'Alene Nursery in Idaho began to evaluate ways to reduce energy consumption in lighting, refrigeration, and heating and cooling of facility workspace. The primary factor leading up to this was the inefficiency of the nursery's Freon(R)-based refrigeration system. Energy costs and maintenance of the system were becoming...

Associations between clinical outcome and navigated transcranial magnetic stimulation characteristics in patients with motor-eloquent brain lesions: a combined navigated transcranial magnetic stimulation-diffusion tensor imaging fiber tracking approach.

PubMed

Sollmann, Nico; Wildschuetz, Noémie; Kelm, Anna; Conway, Neal; Moser, Tobias; Bulubas, Lucia; Kirschke, Jan S; Meyer, Bernhard; Krieg, Sandro M

2018-03-01

OBJECTIVE Navigated transcranial magnetic stimulation (nTMS) and diffusion tensor imaging fiber tracking (DTI FT) based on nTMS data are increasingly used for preoperative planning and resection guidance in patients suffering from motor-eloquent brain tumors. The present study explores whether nTMS-based DTI FT can also be used for individual preoperative risk assessment regarding surgery-related motor impairment. METHODS Data derived from preoperative nTMS motor mapping and subsequent nTMS-based tractography in 86 patients were analyzed. All patients suffered from high-grade glioma (HGG), low-grade glioma (LGG), or intracranial metastasis (MET). In this context, nTMS-based DTI FT of the corticospinal tract (CST) was performed at a range of fractional anisotropy (FA) levels based on an individualized FA threshold ([FAT]; tracking with 50%, 75%, and 100% FAT), which was defined as the highest FA value allowing for visualization of fibers (100% FAT). Minimum lesion-to-CST distances were measured, and fiber numbers of the reconstructed CST were assessed. These data were then correlated with the preoperative, postoperative, and follow-up status of motor function and the resting motor threshold (rMT). RESULTS At certain FA levels, a statistically significant difference in lesion-to-CST distances was observed between patients with HGG who had no impairment and those who developed surgery-related transient or permanent motor deficits (75% FAT: p = 0.0149; 100% FAT: p = 0.0233). In this context, no patient with a lesion-to-CST distance ≥ 12 mm suffered from any new surgery-related permanent paresis (50% FAT and 75% FAT). Furthermore, comparatively strong negative correlations were observed between the rMT and lesion-to-CST distances of patients with surgery-related transient paresis (Spearman correlation coefficient [r s ]; 50% FAT: r s = -0.8660; 75% FAT: r s = -0.8660) or surgery-related permanent paresis (50% FAT: r s = -0.7656; 75% FAT: r s = -0.6763). CONCLUSIONS This is one of the first studies to show a direct correlation between imaging, clinical status, and neurophysiological markers for the integrity of the motor system in patients with brain tumors. The findings suggest that nTMS-based DTI FT might be suitable for individual risk assessment in patients with HGG, in addition to being a surgery-planning tool. Importantly, necessary data for risk assessment were obtained without significant additional efforts, making this approach potentially valuable for direct clinical use.

Development of europium doped core-shell silica cobalt ferrite functionalized nanoparticles for magnetic resonance imaging.

PubMed

Kevadiya, Bhavesh D; Bade, Aditya N; Woldstad, Christopher; Edagwa, Benson J; McMillan, JoEllyn M; Sajja, Balasrinivasa R; Boska, Michael D; Gendelman, Howard E

2017-02-01

The size, shape and chemical composition of europium (Eu 3+ ) cobalt ferrite (CFEu) nanoparticles were optimized for use as a "multimodal imaging nanoprobe" for combined fluorescence and magnetic resonance bioimaging. Doping Eu 3+ ions into a CF structure imparts unique bioimaging and magnetic properties to the nanostructure that can be used for real-time screening of targeted nanoformulations for tissue biodistribution assessment. The CFEu nanoparticles (size ∼7.2nm) were prepared by solvothermal techniques and encapsulated into poloxamer 407-coated mesoporous silica (Si-P407) to form superparamagnetic monodisperse Si-CFEu nanoparticles with a size of ∼140nm. Folic acid (FA) nanoparticle decoration (FA-Si-CFEu, size ∼140nm) facilitated monocyte-derived macrophage (MDM) targeting. FA-Si-CFEu MDM uptake and retention was higher than seen with Si-CFEu nanoparticles. The transverse relaxivity of both Si-CFEu and FA-Si-CFEu particles were r 2 =433.42mM -1 s -1 and r 2 =419.52mM -1 s -1 (in saline) and r 2 =736.57mM -1 s -1 and r 2 =814.41mM -1 s -1 (in MDM), respectively. The results were greater than a log order-of-magnitude than what was observed at replicate iron concentrations for ultrasmall superparamagnetic iron oxide (USPIO) particles (r 2 =31.15mM -1 s -1 in saline) and paralleled data sets obtained for T 2 magnetic resonance imaging. We now provide a developmental opportunity to employ these novel particles for theranostic drug distribution and efficacy evaluations. A novel europium (Eu 3+ ) doped cobalt ferrite (Si-CFEu) nanoparticle was produced for use as a bioimaging probe. Its notable multifunctional, fluorescence and imaging properties, allows rapid screening of future drug biodistribution. Decoration of the Si-CFEu particles with folic acid increased its sensitivity and specificity for magnetic resonance imaging over a more conventional ultrasmall superparamagnetic iron oxide particles. The future use of these particles in theranostic tests will serve as a platform for designing improved drug delivery strategies to combat inflammatory and infectious diseases. Copyright © 2016 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

R&D of high reliable refrigeration system for superconducting generators

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hosoya, T.; Shindo, S.; Yaguchi, H.

1996-12-31

Super-GM carries out R&D of 70 MW class superconducting generators (model machines), refrigeration system and superconducting wires to apply superconducting technology to electric power apparatuses. The helium refrigeration system for keeping field windings of superconducting generator (SCG) in cryogenic environment must meet the requirement of high reliability for uninterrupted long term operation of the SCG. In FY 1992, a high reliable conventional refrigeration system for the model machines was integrated by combining components such as compressor unit, higher temperature cold box and lower temperature cold box which were manufactured utilizing various fundamental technologies developed in early stage of the projectmore » since 1988. Since FY 1993, its performance tests have been carried out. It has been confirmed that its performance was fulfilled the development target of liquefaction capacity of 100 L/h and impurity removal in the helium gas to < 0.1 ppm. Furthermore, its operation method and performance were clarified to all different modes as how to control liquefaction rate and how to supply liquid helium from a dewar to the model machine. In addition, the authors have made performance tests and system performance analysis of oil free screw type and turbo type compressors which greatly improve reliability of conventional refrigeration systems. The operation performance and operational control method of the compressors has been clarified through the tests and analysis.« less

Thermochemical Concrete Pavement Scaling Mechanism: Navy F/A-18 Jet Aircraft Parking Apron Problem

DTIC Science & Technology

1998-06-01

boiling and recondensation) in hot, concentrated potassium hydroxide (E): Eqn 11 Alkaline Hydrolysis of Esters with Potassium Hydroxide KOH...RC02R’ -> KC02R + R’OH potassium alkyl ester (B) potassium ethanol(L) hydroxide (E) carboxylate (F) The overall reaction appears to make sense...carbonate (H) water 2. The parallel between calcium hydroxide and potassium hydroxide is not very accurate. Potassium hydroxide is a much stronger alkali

Omega-6 and omega-3 fatty acids metabolism pathways in the body of pigs fed diets with different sources of fatty acids.

PubMed

Skiba, Grzegorz; Poławska, Ewa; Sobol, Monika; Raj, Stanisława; Weremko, Dagmara

2015-01-01

This study was carried out on 24 gilts (♀ Polish Large White × ♂ Danish Landrace) grown with body weight (BW) of 60 to 105 kg. The pigs were fed diets designed on the basis of a standard diet (appropriate for age and BW of pigs) where a part of the energy content was replaced by different fat supplements: linseed oil in Diet L, rapeseed oil in Diet R and fish oil in Diet F (6 gilts per dietary treatment). The fat supplements were sources of specific fatty acids (FA): in Diet L α-linolenic acid (C18:3 n-3, ALA); in Diet R linoleic acid (C18:2 n-6, LA) and in Diet F eicosapentaenoic acid (C20:5 n-3, EPA), docosapentaenoic acid (C22:5 n-3, DPA) and docosahexaenoic acid (C22:6 n-3, DHA). The protein, fat and total FA contents in the body did not differ among groups of pigs. The enhanced total intake of LA and ALA by pigs caused an increased deposition of these FA in the body (p < 0.01) and an increased potential body pool of these acids for further metabolism/conversions. The conversion efficiency of LA and ALA from the feed to the pig's body differed among groups (p < 0.01) and ranged from 64.4% to 67.2% and from 69.4% to 81.7%, respectively. In Groups L and R, the level of de novo synthesis of long-chain polyunsaturated FA was higher than in Group F. From the results, it can be concluded that the efficiency of deposition is greater for omega-3 FA than for omega-6 FA and depends on their dietary amount. The level of LA and ALA intake influences not only their deposition in the body but also the end products of the omega-3 and omega-6 pathways.

Handbook of Inviscid Sphere-Cone Flow Fields and Pressure Distributions. Volume 2

DTIC Science & Technology

1975-12-01

r, ý I A ror) rv N Ay(T rfrFvTC. TP NTS I YrP/L VP/C YVfP/LV PN/Q0 *5c07 3 r 47 A ,Ir )6A S4 * ec; 445 AL?~ .R?; * 179 p 0 In -󈧻 C; C 3 c* t. 31 *i77...distribuion unlimited 3publJ NAVAL SURFACE WEAPONS CENTER WHITE OAK, SILVER SPRING, MARYLAND 20910 Ii REPORT DOCUMENTATION PAGE HAJNICIN ൒" 1~ A C t...SSION.. h I tFC 0 Fi~(0 OF INVI𔃿C1 rirr .g!n- TC< -P rF.FA"T,. JMFSSURF rTs’TR!PIP10N\\e- _____________ T~l t 6S PEROft..𔃿OlR5 EOT .I A CONTRPA:- r :; A

MiR-375 inhibits the hepatocyte growth factor-elicited migration of mesenchymal stem cells by downregulating Akt signaling.

PubMed

He, Lihong; Wang, Xianyao; Kang, Naixin; Xu, Jianwei; Dai, Nan; Xu, Xiaojing; Zhang, Huanxiang

2018-04-01

The migration of mesenchymal stem cells (MSCs) is critical for their use in cell-based therapies. Accumulating evidence suggests that microRNAs are important regulators of MSC migration. Here, we report that the expression of miR-375 was downregulated in MSCs treated with hepatocyte growth factor (HGF), which strongly stimulates the migration of these cells. Overexpression of miR-375 decreased the transfilter migration and the migration velocity of MSCs triggered by HGF. In our efforts to determine the mechanism by which miR-375 affects MSC migration, we found that miR-375 significantly inhibited the activation of Akt by downregulating its phosphorylation at T308 and S473, but had no effect on the activity of mitogen-activated protein kinases. Further, we showed that 3'phosphoinositide-dependent protein kinase-1 (PDK1), an upstream kinase necessary for full activation of Akt, was negatively regulated by miR-375 at the protein level. Moreover, miR-375 suppressed the phosphorylation of focal adhesion kinase (FAK) and paxillin, two important regulators of focal adhesion (FA) assembly and turnover, and decreased the number of FAs at cell periphery. Taken together, our results demonstrate that miR-375 inhibits HGF-elicited migration of MSCs through downregulating the expression of PDK1 and suppressing the activation of Akt, as well as influencing the tyrosine phosphorylation of FAK and paxillin and FA periphery distribution.

Comparison of Analytical and Experimental Effectiveness of Four-Row Plate-Fin-Tube Heat Exchangers with Water, R-22, and R-410A

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baxter, V.D.; Chen, T.D.; Conklin, J.C.

1998-11-15

The analytical solutions of heat exchanger effectiveness for four-row crcmilow, cross-countertlow and cross-paralleltlow have been derived in the recent study. The main objective of this study is to investigate the etlkct of heat exchawger tlow conllguration on thermal performance with refrigerant mixtures. Difference of heat exchanger effectiveness for all flow arrangements relative to an analytical many-row solution has been analyzed. A comparison of four-row cross cou~ltet-ilow heat exchanger effectiveness between analytical solutions and experimental data with water, R-22, and R-4 10A is presented.

The Steep Ramp Test in Dutch white children and adolescents: age- and sex-related normative values.

PubMed

Bongers, Bart C; de Vries, Sanne I; Obeid, Joyce; van Buuren, Stef; Helders, Paul J M; Takken, Tim

2013-11-01

The Steep Ramp Test (SRT), a feasible, reliable, and valid exercise test on a cycle ergometer, may be more appealing for use in children in daily clinical practice than the traditional cardiopulmonary exercise test because of its short duration, its resemblance to children's daily activity patterns, and the fact that it does not require respiratory gas analysis. The aim of the present study was to provide sex- and age-related normative values for SRT performance in Dutch white children and adolescents who were healthy and 8 to 19 years old. This was a cross-sectional, observational study. A total of 252 Dutch white children and adolescents, 118 boys (mean age=13.4 years, SD=3.0) and 134 girls (mean age=13.4 years, SD=2.9), performed the SRT (work rate increment of 10, 15, or 20 W·10 s(-1), depending on body height) to voluntary exhaustion to assess peak work rate (WRpeak). Normative values are presented as reference centiles developed by use of generalized additive models for location, scale, and shape. Peak work rate correlated highly with age (r=.915 and r=.811), body mass (r=.870 and r=.850), body height (r=.922 and r=.896), body surface area (r=.906 and r=.885), and fat free mass (r=.930 and r=.902) in boys and girls, respectively. The reference curves demonstrated an almost linear increase in WRpeak with age in boys, even when WRpeak was normalized for body mass. In contrast, absolute WRpeak in girls increased constantly until the age of approximately 13 years, when it started to level off. Peak work rate normalized for body mass in girls showed only a slight increase with age until 14 years of age, when a slight decrease in relative WRpeak was observed. The sample may not have been entirely representative of the Dutch population. The present study provides sex- and age-related normative values for SRT performance in terms of both absolute WRpeak and relative WRpeak, thereby facilitating the interpretation of SRT results by clinicians and researchers.

Carotid and Femoral Arterial Wall Distensibility During Long-Duration Spaceflight.

PubMed

Arbeille, Philippe; Provost, Romain; Zuj, Kathryn

2017-10-01

This study aimed to assess changes in common carotid (CA) and superficial femoral (FA) arterial stiffness during long-duration spaceflight. Ultrasound imaging was used to investigate the CA and FA of 10 astronauts preflight (PRE), on flight day 15 (FD15), after 4-5 mo (FD4-5m), and 4 d after return to Earth (R+4). Arterial wall properties were assessed through the calculation of strain, stiffness (β), pressure-strain elastic modulus (Ep), and distensibility (DI). Stiffness indices were assessed for potential correlations to measurements of intima-media thickness (IMT). Significant effects of spaceflight were found for all CA stiffness indices, indicating an increase in arterial stiffness. CA strain was reduced by 34 ± 31% on FD15 and 50 ± 16% on FD4-5m and remained reduced by 42 ± 14% on R+4 with respect to PRE values. On FD4-5m, with respect to PRE values, DI was reduced by 46 ± 25% and β and Ep were increased by 124 ± 95% and 118 ± 92%, respectively. FA arterial stiffness indices appeared to show similar changes; however, a main effect of spaceflight was only found for strain. Correlation analysis showed weak but significant relationships between measurements of CA IMT and arterial stiffness indices, but no relationships were found for FA measurements. The observed change in CA and FA stiffness indices suggest that spaceflight results in an increase in arterial stiffness. That these changes were not strongly related to measurements of IMT suggests the possibility of different mechanisms contributing to the observed results.Arbeille P, Provost R, Zuj K. Carotid and femoral arterial wall distensibility during long-duration spaceflight. Aerosp Med Hum Perform. 2017; 88(10):924-930.

Additives for Water Mist Fire Suppression Systems: A Review

DTIC Science & Technology

2012-11-01

TM 2012-236; R & D pour la défense Canada – Atlantique; novembre 2012. Introduction : On utilisait les halons comme agents extincteurs dans les... 13 Table 11: Results of fire extinguishment tests on kerosene or heptanes pan fires using water mist and water mist with 2 vol...Forafac® WM. ....................................................... 13 x DRDC Atlantic TM 2012-236 This page intentionally left

Numerical Modelling of Coherent Broadband Pulses for Seismic Exploration

DTIC Science & Technology

2011-11-01

236 ; Recherche et développement pour la défense Canada – Atlantique ; novembre 2011. Contexte : En exploration sismique marine, on utilise...4 Discussion of Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 Annex A: Details of the scattering matrix R...attenuation. The results are shown after multiplication by 1.E6 . . . . . . . . . . . 13 viii DRDC Atlantic TM 2011-236 Figure 11: The Ricker wavelet (blue) and

New Priorities for a Changing U.S. Economy

DTIC Science & Technology

1999-01-08

Stockholm, Sweden, 1991. [73] R . Malladi , J. Sethian, B. and Vermuri, "Shape modelling with front propagation: a level set approach," IEEE PAMI17...represented as n x n matrices of operators in £(£), and r (") is represented by a diagonal matrix, with diagonal entries equal to T. Denote by An...also has independent interest. Theorem 1 Assume that A’ is a *-algebra of finite dimension n. Then fa(A) = ^..(Art) for every A 6 £(£)~ r ~ Remark

An Example of Wang and Yau's Quasilocal Energy for Constant Radial Spacelike 2-Surfaces in a Maximally Rotating Black Hole Spacetime

NASA Astrophysics Data System (ADS)

Ray, Shannon; Miller, Warner

2017-01-01

We present the first non-trivial illustration of Wang and Yau's quasilocal energy (WYQLE) for a maximally rotating Kerr spacetime. The surfaces for which we compute quasilocal energy (QLE) are axisymmetric closed space like 2-surfaces S with constant radii in Boyer-Lindquist coordinates. There exists a critical radius r* for which these 2-surfaces are isometrically embeddable in R3 . For surfaces with r >=r* , the WYQLE trivially becomes the Brown and York QLE (BYQLE). To fully illustrate Wang and Yau's formulation, we compute the WYQLE for surfaces with r

Different patterns of supramolecular assembly in constitutionally similar 6-arylimidazo[2,1-b][1,3,4]thiadiazoles.

PubMed

Praveen, Aletti S; Yathirajan, Hemmige S; Kaur, Manpreet; Narayana, Badiadka; Hosten, Eric C; Betz, Richard; Glidewell, Christopher

2014-09-01

Four imidazo[2,1-b][1,3,4]thiadiazoles containing a simply-substituted 6-aryl group have been synthesized by reaction of 2-amino-1,3,4-thiadiazoles with bromoacetylarenes using microwave irradiation and brief reaction times. 6-(2-Chlorophenyl)imidazo[2,1-b][1,3,4]thiadiazole, C(10)H(6)ClN(3)S, (I), 6-(2-chlorophenyl)-2-methylimidazo[2,1-b][1,3,4]thiadiazole, C(11)H(8)ClN(3)S, (II), 6-(3,4-dichlorophenyl)imidazo[2,1-b][1,3,4]thiadiazole, C(10)H(5)Cl(2)N(3)S, (III), and 6-(4-fluoro-3-methoxyphenyl)-2-methylimidazo[2,1-b][1,3,4]thiadiazole, C(12)H(10)FN(3)OS, (IV), crystallize with Z' values of 2, 1, 1 and 2 respectively. The molecular skeletons are all nearly planar and the dihedral angles between the imidazole and aryl rings are 1.51 (8) and 7.28 (8)° in (I), 9.65 (7)° in (II), 10.44 (8)° in (III), and 1.05 (8) and 7.21 (8)° in (IV). The molecules in (I) are linked by three independent C-H...N hydrogen bonds to form ribbons containing alternating R2(2)(8) and R4(4)(18) rings, and these ribbons are linked into a three-dimensional array by three independent π-stacking interactions. Both (II) and (III) contain centrosymmetric dimers formed by π-stacking interactions but hydrogen bonds are absent, and the molecules of (IV) are linked into centrosymmetric R2(2)(8) dimers by C-H...N hydrogen bonds. Comparisons are made with a number of related compounds.

STUDIES OF HALOGENATED HYDROCARBONS. PART 1 - STABILITY OF FLUOROCARBONS IN AIR OVER HOPCALITE CATALYST OR STAINLESS STEEL

DTIC Science & Technology

A study was made of the catalytic decomposition of a number of fluorine-containing halogenated hydrocarbons in air, using Hopcalite catalyst in a... Hopcalite catalyst had no significant effect on the rate of decomposition of the chlorofluorocarbons. Sulfur hexafluoride in air was stable over Hopcalite ...as those of nuclear submarines. Where they are needed, as in refrigeration systems, it is recommended that R-114, R-14, or R-12 be used since they show the greatest resistance to Hopcalite -catalyzed decomposition.

Department of the Navy Fiscal Year (FY) 2001 Budget Estimates. Justification of Estimates, February 2000, Research, Development, Test and Evaluation, Navy Budget Activities 1-3

DTIC Science & Technology

2000-02-01

4-> mem 4J rl cn Di o w w rHßOJlHW ß4-)rdftiH>lO T) rH 0) ft 0 ß cd o n. o-Hxiocn -HtdMotCDiVH ß (d ä o o b ft o... OHP fa U fa H > U C3 D D ID D D O JL X >~H ^3 X g M ft ft& ft * % O S 13 SB ß u o -H CN 4J CO 14H U n •H MH CN •H 4-> tt) CO m

Symbolic Image Understanding

DTIC Science & Technology

1991-11-01

publication. APPROVED: a LEE A. UVANNI Project Engineer FOR THE COMMANDER: GARRY W. BARRINGER Technical Director Intelligence & Reconnaissance...f Od1cAtl nd ir-’bm a UNl tofU~rtaw ."t Pu’ o scrxr± ing twra fa revrl r Jt,= seagrg d un zla souLces gahwtW" r T , iUm rm , rruk4 c adiwvctws coa w...1990j matches straight lines extracted from an image with model lines r projected to the image plane using an assumed location of the camera. This

Fibrillation auriculaire et activité physique

PubMed Central

Bosomworth, N. John

2015-01-01

Résumé Objectif Examiner les données probantes portant sur les effets de divers niveaux d’activité physique sur l’incidence de fibrillation auriculaire (FA) dans la population générale et chez les athlètes d’endurance. Sources des données Une recherche a initialement été menée sur PubMed à l’aide des titres MeSH ou des mots-de-texte anglais (avec descripteur de zone de recherche TIAB [title and abstract]) atrial fibrillation et exercise ou physical activity ou athlet* ou sport*, sans filtre additionnel. Le système GRADE (grading of recommendations, assessment, development, and evaluation) a été utilisé pour tirer les conclusions au sujet de la qualité et du niveau de preuve. Sélection des études Aucune étude d’intervention n’est ressortie de la recherche. Les études d’observation ont alors été jugées acceptables et, bien que des études prospectives de cohortes à long terme de plus grande envergure auraient été préférables, des essais cas-témoins ou transversaux ont aussi été inclus dans cette révision. Synthèse Les données disponibles laissent croire à un lien proportionnel à la dose entre l’exercice plus intense et l’incidence réduite de FA chez les femmes. Il en va de même pour les hommes dont le niveau d’activité physique est de faible à modéré. Chez les hommes seulement, l’activité intense est associée à un risque accru de FA et ce, dans la plupart des études, mais pas la totalité d’entre elles. Ce risque est modéré, le rapport de risque instantané étant de 1,29 dans l’une des études de meilleure qualité. Le risque de FA chez la plupart des personnes régulièrement actives est plus faible que le risque observé dans la population sédentaire appariée. Conclusion La fibrillation auriculaire est probablement moins fréquente à mesure que le niveau d’activité physique augmente, la relation dose-réponse étant démontrable. À toutes les intensités, l’exercice doit être encouragé pour ses effets sur le bien-être physique et la réduction de la mortalité. Chez les hommes qui pratiquent des activités vigoureuses, les effets bénéfiques sur la FA pourraient disparaître et le risque pourrait surpasser celui observé dans la population sédentaire; cependant les données probantes à cet effet ne sont ni robustes ni constantes. Ces hommes devraient être mis au courant de cette hausse modeste du risque s’ils choisissent de poursuivre leurs activités physiques vigoureuses.

Evaluation of neuraminidase enzyme assays using different substrates to measure susceptibility of influenza virus clinical isolates to neuraminidase inhibitors: report of the neuraminidase inhibitor susceptibility network.

PubMed

Wetherall, N T; Trivedi, T; Zeller, J; Hodges-Savola, C; McKimm-Breschkin, J L; Zambon, M; Hayden, F G

2003-02-01

The increasing use of influenza virus neuraminidase (NA) inhibitors (NIs) necessitates the development of reliable methods for assessing the NI susceptibility of clinical isolates. We evaluated three NA inhibition assays against a panel of five clinical isolates each of influenza virus A/H1N1, A/H3N2, and B strains and four viruses with a defined resistance genotype (R292K, H274Y, R152K, and E119V). For fluorometric enzyme assay (FA) 1 (FA-1), 2'-(4-methylumbelliferyl)-alpha-D-N-acetylneuraminic acid (MUNANA) at 100 microM was used as the substrate, with pretitration of the virus input. For FA-2, MUNANA at 200 microM was used as the substrate, with a fixed 1:10 dilution of input virus. For the chemiluminescence (CL) assay, the 1,2-dioxetane derivative of sialic acid at 100 microM was used as the substrate, with pretitration of the virus. Four different operators repeated the assays several times in a blinded fashion with both zanamivir and oseltamivir carboxylate (GS4071) to determine intra- and interassay variations. Mean 50% inhibitory concentration (IC(50)) values were lower and generally less variable with the CL assay. FA-1 displayed greater variation than the CL assay or FA-2 and the highest IC(50) values with zanamivir; FA-2 showed the highest values with oseltamivir, particularly for influenza virus B, and was more variable with zanamivir than was the CL assay. All three assays detected 40-fold or greater changes in IC(50) values for the resistant viruses with at least one drug. Mixing experiments, whereby increasing fractions (0, 20, 40, 60, 80, and 100%) of NA from a known NI-resistant virus were mixed with the corresponding NI-sensitive parental NA, indicated that the resolution of IC(50) values was clearer with the CL assay than with FA-2 for two of the resistant variants (R152K and E119V). The FA and CL methods were reliable for the detection of NI resistance, but all assays have certain limitations. Based on reproducibility, ease of automation, time required for the assay, and greater sensitivity, the CL assay was selected for future susceptibility testing of influenza virus isolates circulating globally.

Design and optimization of organic rankine cycle for low temperature geothermal power plant

NASA Astrophysics Data System (ADS)

Barse, Kirtipal A.

Rising oil prices and environmental concerns have increased attention to renewable energy. Geothermal energy is a very attractive source of renewable energy. Although low temperature resources (90°C to 150°C) are the most common and most abundant source of geothermal energy, they were not considered economical and technologically feasible for commercial power generation. Organic Rankine Cycle (ORC) technology makes it feasible to use low temperature resources to generate power by using low boiling temperature organic liquids. The first hypothesis for this research is that using ORC is technologically and economically feasible to generate electricity from low temperature geothermal resources. The second hypothesis for this research is redesigning the ORC system for the given resource condition will improve efficiency along with improving economics. ORC model was developed using process simulator and validated with the data obtained from Chena Hot Springs, Alaska. A correlation was observed between the critical temperature of the working fluid and the efficiency for the cycle. Exergy analysis of the cycle revealed that the highest exergy destruction occurs in evaporator followed by condenser, turbine and working fluid pump for the base case scenarios. Performance of ORC was studied using twelve working fluids in base, Internal Heat Exchanger and turbine bleeding constrained and non-constrained configurations. R601a, R245ca, R600 showed highest first and second law efficiency in the non-constrained IHX configuration. The highest net power was observed for R245ca, R601a and R601 working fluids in the non-constrained base configuration. Combined heat exchanger area and size parameter of the turbine showed an increasing trend as the critical temperature of the working fluid decreased. The lowest levelized cost of electricity was observed for R245ca followed by R601a, R236ea in non-constrained base configuration. The next best candidates in terms of LCOE were R601a, R245ca and R600 in non-constrained IHX configuration. LCOE is dependent on net power and higher net power favors to lower the cost of electricity. Overall R245ca, R601, R601a, R600 and R236ea show better performance among the fluids studied. Non constrained configurations display better performance compared to the constrained configurations. Base non-constrained offered the highest net power and lowest LCOE.

A New Multiplier Structure for Digital Signal Processing

DTIC Science & Technology

1980-01-01

8217 ’) ’ 1 ’ ’ ":"/’.4 -r ,’::33,!. ,4 .1,4 .. . ...;.r I ’I,’ C!’ vdI I"., 1" r;’O . ;AOO..󈧳 -, :𔄀. "’ rO0000’:’- 4 . 6.67 - 1733:::: .. 1...pipelined execution rate can he purchased at a small hardware cost. Example: p - 211 . 2048 , x = 1040, y = 352, then Z = <xy>p 1536 S + + Al:s = 1376; (j(s

A Combined Experimental and Computational Study on the Stability of Nanofluids Containing Metal Organic Frameworks

DOE Office of Scientific and Technical Information (OSTI.GOV)

Annapureddy, Harsha Vardhan Reddy; Nune, Satish K.; Motkuri, Radha K.

2015-01-08

Computational studies on nanofluids composed of metal organic frameworks (MOFs) were performed using molecular modeling techniques. Grand Canonical Monte Carlo (GCMC) simulations were used to study adsorption behavior of 1,1,1,3,3-pentafluoropropane (R-245fa) in a MIL-101 MOF at various temperatures. To understand the stability of the nanofluid composed of MIL-101 particles, we performed molecular dynamics simulations to compute potentials of mean force between hypothetical MIL-101 fragments terminated with two different kinds of modulators in R-245fa and water. Our computed potentials of mean force results indicate that the MOF particles tend to disperse better in water than in R-245fa. The reasons for thismore » observation were analyzed and discussed. Our results agree with experimental results indicating that the employed potential models and modeling approaches provide good description of molecular interactions and the reliabilities. Work performed by LXD was supported by the U.S. Department of Energy (DOE), Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences, and Biosciences. Work performed by HVRA, SKN, RKM, and PBM was supported by the Office of Energy Efficiency and Renewable Energy, Geothermal Technologies Program. Pacific Northwest National Laboratory is a multiprogram national laboratory operated for DOE by Battelle.« less

Optical Refrigeration to 119 K, below National Institute of Standards and Technology Cryogenic Temperature

DTIC Science & Technology

2013-05-01

I . Epstein, and S. Kurtz, Proc. SPIE 6115, 215 (2006). 18. C. Hoyt, M. Hasselbeck, M. Sheik- Bahae , R. Epstein, S. Greenfield, J. Thiede, J. Distel...achieve cooling are ( i ) high external quantum efficiency (EQE) transition in the dopant ion and (ii) high purity of the host material. Ignor- ing...1929). 2. R. Epstein, M. Buchwald, B. Edwards, T. Gosnell, and C. E. Mungan, Nature 377, 500 (1995). 3. M. Sheik- Bahae and R. Epstein, Nat. Photonics

Ceramics for High Power Lasers

DTIC Science & Technology

2013-07-01

139-144 (Wiley, 2009). [22] M.F. Becker, D.J. Kuizenga, A.E. Siegman , “Harmonic Mode Locking of the Nd:YAG Laser ,” IEEE Journal of Quantum...AFRL-OSR-VA-TR-2013-0347 Ceramics for High Power Lasers R.L. Byer, R.M. Gaume, R.K. Route, C. Rudy Stanford University July...To) 05-15-2010 to 05-15-2013 4. TITLE AND SUBTITLE Ceramics for High Power Lasers 5a. CONTRACT NUMBER 5b. GRANT NUMBER FA9550-10-1-0227

Candidates to replace R-12 as a radiator gas in Cherenkov detectors

NASA Astrophysics Data System (ADS)

Harvey, Allan H.; Paulechka, Eugene; Egan, Patrick F.

2018-06-01

Dichlorodifluoromethane (R-12) has been widely used as a radiator gas in pressure threshold Cherenkov detectors for high-energy particle physics. However, that compound is becoming unavailable due to the Montreal Protocol. To find a replacement with suitably high refractive index, we use a combination of theory and experiment to examine the polarizability and refractivity of several non-ozone-depleting compounds. Our measurements show that the fourth-generation refrigerants R-1234yf (2,3,3,3-tetrafluoropropene) and R-1234ze(E) (trans-1,3,3,3-tetrafluoropropene) have sufficient refractivity to replace R-12 in this application. If the slight flammability of these compounds is a problem, two nonflammable alternatives are R-218 (octafluoropropane), which has a high Global Warming Potential, and R-13I1 (trifluoroiodomethane), which has low Ozone Depletion Potential and Global Warming Potential but may not be sufficiently inert.

Efficacy of Cyto-Chex blood preservative for delayed manual CD4 testing using Dynal T4 Quant CD4 test among HIV-infected persons in Zambia.

PubMed

Truett, April A; Letizia, Andrew; Malyangu, Evans; Sinyangwe, Frank; Morales, Brandi N; Crum, Nancy F; Crowe, Suzanne M

2006-02-01

Manual CD4 tests such as Dynal T4 Quant (Dynabeads, Dynal Biotech, Oslo, Norway) are less expensive alternatives to flow cytometry in resource-limited countries. Whereas blood preservatives have proven useful for stabilizing blood samples to allow delayed CD4 testing by flow cytometry, they have not been verified for manual tests. A method for preservation of blood prior to manual CD4 testing is needed for long-distance transport or sample batching. Blood from HIV-positive Zambian military beneficiaries was mixed (1:1) with Cyto-Chex (Streck Laboratories, La Vista, NE) blood preservative, and the blood was stored at refrigerated, ambient, and incubator (37 degrees C) temperatures prior to Dynabeads CD4 testing at 0, 3, 6, and 9 days after collection. Baseline flow cytometry and Dynabeads testing without preservative were performed for comparison. Twenty-seven patient samples were analyzed. Dynabeads vs. flow cytometry had a correlation coefficient (r) of 0.84. There was excellent correlation (r = 0.96) between baseline Dynabeads testing and Cyto-Chex-preserved samples. Refrigerated samples showed strong correlation with baseline Dynabeads (r = 0.93-0.95) on days 3, 6, and 9 without decline in CD4 count (P = 0.73). Samples stored at ambient temperature yielded inferior results (r = 0.76-0.81), with a significant decline in CD4 count by day 3 (P < 0.001). The incubator arm had especially poor correlation (r = 0.30-0.49). Addition of Cyto-Chex to peripheral blood (1:1) adequately preserves refrigerated blood samples for up to 9 days for subsequent testing with Dynabeads CD4 test. Cyto-Chex, however, cannot be recommended for delayed Dynabeads CD4 testing with storage at 37 degrees C or ambient temperatures in tropical areas similar to the site of this study.

Enantioselective analysis of chiral anteiso fatty acids in the polar and neutral lipids of food.

PubMed

Hauff, Simone; Hottinger, Georg; Vetter, Walter

2010-04-01

Anteiso fatty acids (aFA) are substituted with a methyl group on the antepenultimate carbon of the straight acyl chain. This feature leads to a stereogenic center. The 12-methyltetradecanoic acid (a15:0) and the 14-methylhexadecanoic acid (a17:0) are the most common aFA found in food, although they occur only in very small quantities. In this study we used gas chromatography in combination with a chiral stationary phase to determine the enantiomeric distribution of both a15:0 and a17:0 in the neutral and polar lipids of aquatic food samples and cheese. The best suited column was selected out of four custom-made combinations of heptakis(6-O-tert-butyldimethylsilyl-2,3-di-O-methyl)-beta-cyclodextrin (beta-TBDM) with different amount and polarity of an achiral polysiloxane. After separation of polar and neutral lipids of the food samples by solid phase extraction, fatty acid methyl esters were prepared and the fatty acid methyl esters were fractionated by reversed phase high performance liquid chromatography. Measurements of fractions high in aFA by enantioselective GC/MS in the selected ion monitoring mode verified the dominance of the (S)-enantiomers of a15:0 and a17:0 in both lipid fractions. However (R)-enantiomers were detectable in all samples. The relative proportion of the (R)-enantiomers was up to fivefold higher in the polar lipids than in the neutral lipids. The higher proportions in the polar lipids indicate that microorganisms might be involved in the formation of (R)-aFA.

Assessment of Passive Intestinal Permeability Using an Artificial Membrane Insert System.

PubMed

Berben, Philippe; Brouwers, Joachim; Augustijns, Patrick

2018-01-01

Despite reasonable predictive power of current cell-based and cell-free absorption models for the assessment of intestinal drug permeability, high costs and lengthy preparation steps hamper their use. The use of a simple artificial membrane (without any lipids present) as intestinal barrier substitute would overcome these hurdles. In the present study, a set of 14 poorly water-soluble drugs, dissolved in 2 different media (fasted state simulated/human intestinal fluids [FaSSIF/FaHIF]), were applied to the donor compartment of an artificial membrane insert system (AMI-system) containing a regenerated cellulose membrane. Furthermore, to investigate the predictive capacity of the AMI-system as substitute for the well-established Caco-2 system to assess intestinal permeability, the same set of 14 drugs dissolved in FaHIF were applied to the donor compartment of a Caco-2 system. For 14 drugs, covering a broad range of physicochemical parameters, a reasonable correlation between both absorption systems was observed, characterized by a Pearson correlation coefficient r of 0.95 (FaHIF). Using the AMI-system, an excellent predictive capacity of FaSSIF as surrogate medium for FaHIF was demonstrated (r = 0.96). Based on the acquired data, the AMI-system appears to be a time- and cost-effective tool for the early-stage estimation of passive intestinal permeability for poorly water-soluble drugs. Copyright © 2018 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

Peptide modified nanofibrous scaffold promotes human mesenchymal stem cell proliferation and long-term passaging.

PubMed

Mobasseri, Rezvan; Tian, Lingling; Soleimani, Masoud; Ramakrishna, Seeram; Naderi-Manesh, Hossein

2018-03-01

Long-term culture, passage and proliferation of human mesenchymal stem cells (hMSCs) cause loss of their stemness properties including self-renewal and multipotency. By optimizing the MSCs environment in vitro, maintaining the stemness state and better controlling the cell fate might be possible. We have recently reported the significant effects of bioactive Tat protein-derived peptide named R-peptide on hMSC adhesion, morphology and proliferation, which has demonstrated R-peptide enhanced MSC early adhesion and proliferation in comparison to other bioactive molecules including RGD peptide, fibronectin and collagen. In this study, R-peptide was used to evaluate stemness properties of MSCs after long-term passaging. R-peptide conjugated poly caprolactone (PCL) nanofibrous scaffold and unmodified nanofibrous scaffold were used to study the impact of R-peptide modified PCL nanofibers and PCL nanofibers on cell behavior. The results showed early formation of focal adhesion (FA) complex on R-peptide modified scaffolds at 30min after cell seeding. The rate of cell proliferation was significantly increased due to presence of R-peptide, and the MSCs marker analyses using flow cytometry and immunocytochemistry staining proved the ability of R-peptide to maintain mesenchymal stem cell properties (high proliferation, expression of multipotent markers and differentiation capacity) even after long-term passage culturing. Accordingly, our (The) results concluded that bioactive R-peptide in combination with nanofibrous scaffold can mimic the native ECM comprising micro/nano architecture and biochemical molecules in a best way. The designed scaffold can link extracellular matrix (ECM) to nucleus via formation of FA and organization of cytoskeleton, causing fast and strong attachment of MSCs and allowing integrin-mediated signaling to start. Copyright © 2017 Elsevier B.V. All rights reserved.

Flow boiling heat transfer of R134a and R404A in a microfin tube at low mass fluxes and low heat fluxes

NASA Astrophysics Data System (ADS)

Spindler, Klaus; Müller-Steinhagen, Hans

2009-05-01

An experimental investigation of flow boiling heat transfer in a commercially available microfin tube with 9.52 mm outer diameter has been carried out. The microfin tube is made of copper with a total fin number of 55 and a helix angle of 15°. The fin height is 0.24 mm and the inner tube diameter at fin root is 8.95 mm. The test tube is 1 m long and is electrically heated. The experiments have been performed at saturation temperatures between 0 and -20°C. The mass flux was varied between 25 and 150 kg/m2s, the heat flux from 15,000 W/m2 down to 1,000 W/m2. All measurements have been performed at constant inlet vapour quality ranging from 0.1 to 0.7. The measured heat transfer coefficients range from 1,300 to 15,700 W/m2K for R134a and from 912 to 11,451 W/m2K for R404A. The mean heat transfer coefficient of R134a is in average 1.5 times higher than for R404A. The mean heat transfer coefficient has been compared with the correlations by Koyama et al. and by Kandlikar. The deviations are within ±30% and ±15%, respectively. The influence of the mass flux on the heat transfer is most significant between 25 and 62.5 kg/m2s, where the flow pattern changes from stratified wavy flow to almost annular flow. This flow pattern transition is shifted to lower mass fluxes for the microfin tube compared to the smooth tube.

Estimated 2017 Refrigerant Emissions of 2,3,3,3-Tetrafluoropropene (HFC-1234yf) in the United States Resulting from Automobile Air Conditioning

EPA Science Inventory

In response to recent regulations and concern over climate change, the global automotive community is evaluating alternatives to the current refrigerant used in automobile air conditioning units, 1,1,1,2-tetrafluoroethane, HFC-134a. One potential alternative is 2,3,3,3-tetrafluor...

Spectrum of FANCA mutations in Italian Fanconi anemia patients: identification of six novel alleles and phenotypic characterization of the S858R variant.

PubMed

Savino, Maria; Borriello, Adriana; D'Apolito, Maria; Criscuolo, Maria; Del Vecchio, Maria; Bianco, Anna Monica; Di Perna, Michele; Calzone, Rita; Nobili, Bruno; Zatterale, Adriana; Zelante, Leopoldo; Joenje, Hans; Della Ragione, Fulvio; Savoia, Anna

2003-10-01

Fanconi anemia (FA) is an autosomal recessive disorder characterized by genomic instability, bone marrow failure, congenital malformations, and cancer predisposition. FA is a genetically heterogeneous disease with at least seven genes so far identified. The role of FA proteins is unknown although they interact in a common functional pathway. Here, we report six novel FANCA sequence changes and review all the mutations identified in Italy. Except for two missense substitutions, all are expected to cause a premature termination of the FANCA protein at various sites throughout the molecule. The premature terminations are due to nonsense and splice site mutations, as well as small insertions and deletions, and large genomic rearrangements. The expected truncated proteins were not detectable on Western blot analyses. The FANCA-S858R variant is instead expressed at lower level than that seen in normal cell lines and is associated with a non-ubiquinated FANCD2 protein, strongly suggesting that the amino acid substitution is a disease-causing mutation. The spectrum of FA mutations is widely in agreement with the heterogeneous ethnic origin of the Italian population. Copyright 2003 Wiley-Liss, Inc.

Application of a JA-Ile Biosynthesis Inhibitor to Methyl Jasmonate-Treated Strawberry Fruit Induces Upregulation of Specific MBW Complex-Related Genes and Accumulation of Proanthocyanidins.

PubMed

Delgado, Laura D; Zúñiga, Paz E; Figueroa, Nicolás E; Pastene, Edgar; Escobar-Sepúlveda, Hugo F; Figueroa, Pablo M; Garrido-Bigotes, Adrián; Figueroa, Carlos R

2018-06-13

Fleshy fruits are an important source of anthocyanins and proanthocyanidins (PAs), which protect plants against stress, and their consumption provides beneficial effects for human health. In strawberry fruit, the application of exogenous methyl jasmonate (MeJA) upregulates anthocyanin accumulation, although the relationship between the jasmonate pathway and anthocyanin and PA biosynthesis in fruits remains to be understood. Anthocyanin and PA accumulation is mainly regulated at the transcriptional level through R2R3-MYB and bHLH transcription factors in different plant species and organs. Here, the effect of jarin-1, a specific inhibitor of bioactive JA (jasmonoyl-isoleucine, JA-Ile) biosynthesis, on anthocyanin and PA accumulation was evaluated during strawberry ( Fragaria × ananassa ) fruit development using an in vitro ripening system for 48 h. Also, we observed the effects of MeJA and the application of jarin-1 to MeJA-treated fruits (MeJA + jarin-1 treatment). We assessed changes of expression levels for the JA-Ile and MeJA biosynthetic ( FaJAR1.2 and FaJMT ), JA signaling-related ( FaMYC2 and FaJAZ1 ), MYB-bHLH-WD40 (MBW) complex-related ( FabHLH3/33 , FaMYB9/10/11 , and repressor FaMYB1 ), and anthocyanin and PA biosynthetic (FaANS , FaUFGT , FaANR , and FaLAR ) genes. In addition, the promoter region of MBW complex-related MYB genes was isolated and sequenced. We found a higher redness of strawberry fruit skin and anthocyanin content in MeJA-treated fruits with respect to jarin-1-treated ones concomitant with an upregulation of FaANS and FaUFGT genes. Inversely, the PA content was higher in jarin-1- and MeJA + jarin-1-treated than in MeJA-treated fruits. MeJA + jarin-1 treatment resulted in an upregulation of FaANR and associated transcription factors such as FabHLH33 and FaMYB9/11 along with FaJMT and FaJAR1.2 . Finally, we found JA-responsive elements in the promoter regions of FaMYB1/9/10/11 genes. It is proposed that PA biosynthesis-related genes can be upregulated by the application of jarin-1 to MeJA-treated fruit, thus increasing PA accumulation in strawberry.

Bayesian regression models outperform partial least squares methods for predicting milk components and technological properties using infrared spectral data.

PubMed

Ferragina, A; de los Campos, G; Vazquez, A I; Cecchinato, A; Bittante, G

2015-11-01

The aim of this study was to assess the performance of Bayesian models commonly used for genomic selection to predict "difficult-to-predict" dairy traits, such as milk fatty acid (FA) expressed as percentage of total fatty acids, and technological properties, such as fresh cheese yield and protein recovery, using Fourier-transform infrared (FTIR) spectral data. Our main hypothesis was that Bayesian models that can estimate shrinkage and perform variable selection may improve our ability to predict FA traits and technological traits above and beyond what can be achieved using the current calibration models (e.g., partial least squares, PLS). To this end, we assessed a series of Bayesian methods and compared their prediction performance with that of PLS. The comparison between models was done using the same sets of data (i.e., same samples, same variability, same spectral treatment) for each trait. Data consisted of 1,264 individual milk samples collected from Brown Swiss cows for which gas chromatographic FA composition, milk coagulation properties, and cheese-yield traits were available. For each sample, 2 spectra in the infrared region from 5,011 to 925 cm(-1) were available and averaged before data analysis. Three Bayesian models: Bayesian ridge regression (Bayes RR), Bayes A, and Bayes B, and 2 reference models: PLS and modified PLS (MPLS) procedures, were used to calibrate equations for each of the traits. The Bayesian models used were implemented in the R package BGLR (http://cran.r-project.org/web/packages/BGLR/index.html), whereas the PLS and MPLS were those implemented in the WinISI II software (Infrasoft International LLC, State College, PA). Prediction accuracy was estimated for each trait and model using 25 replicates of a training-testing validation procedure. Compared with PLS, which is currently the most widely used calibration method, MPLS and the 3 Bayesian methods showed significantly greater prediction accuracy. Accuracy increased in moving from calibration to external validation methods, and in moving from PLS and MPLS to Bayesian methods, particularly Bayes A and Bayes B. The maximum R(2) value of validation was obtained with Bayes B and Bayes A. For the FA, C10:0 (% of each FA on total FA basis) had the highest R(2) (0.75, achieved with Bayes A and Bayes B), and among the technological traits, fresh cheese yield R(2) of 0.82 (achieved with Bayes B). These 2 methods have proven to be useful instruments in shrinking and selecting very informative wavelengths and inferring the structure and functions of the analyzed traits. We conclude that Bayesian models are powerful tools for deriving calibration equations, and, importantly, these equations can be easily developed using existing open-source software. As part of our study, we provide scripts based on the open source R software BGLR, which can be used to train customized prediction equations for other traits or populations. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Prediction of the Thermal Conductivity of Refrigerants by Computational Methods and Artificial Neural Network.

PubMed

Ghaderi, Forouzan; Ghaderi, Amir H; Ghaderi, Noushin; Najafi, Bijan

2017-01-01

Background: The thermal conductivity of fluids can be calculated by several computational methods. However, these methods are reliable only at the confined levels of density, and there is no specific computational method for calculating thermal conductivity in the wide ranges of density. Methods: In this paper, two methods, an Artificial Neural Network (ANN) approach and a computational method established upon the Rainwater-Friend theory, were used to predict the value of thermal conductivity in all ranges of density. The thermal conductivity of six refrigerants, R12, R14, R32, R115, R143, and R152 was predicted by these methods and the effectiveness of models was specified and compared. Results: The results show that the computational method is a usable method for predicting thermal conductivity at low levels of density. However, the efficiency of this model is considerably reduced in the mid-range of density. It means that this model cannot be used at density levels which are higher than 6. On the other hand, the ANN approach is a reliable method for thermal conductivity prediction in all ranges of density. The best accuracy of ANN is achieved when the number of units is increased in the hidden layer. Conclusion: The results of the computational method indicate that the regular dependence between thermal conductivity and density at higher densities is eliminated. It can develop a nonlinear problem. Therefore, analytical approaches are not able to predict thermal conductivity in wide ranges of density. Instead, a nonlinear approach such as, ANN is a valuable method for this purpose.

Prediction of the Thermal Conductivity of Refrigerants by Computational Methods and Artificial Neural Network

PubMed Central

Ghaderi, Forouzan; Ghaderi, Amir H.; Ghaderi, Noushin; Najafi, Bijan

2017-01-01

Background: The thermal conductivity of fluids can be calculated by several computational methods. However, these methods are reliable only at the confined levels of density, and there is no specific computational method for calculating thermal conductivity in the wide ranges of density. Methods: In this paper, two methods, an Artificial Neural Network (ANN) approach and a computational method established upon the Rainwater-Friend theory, were used to predict the value of thermal conductivity in all ranges of density. The thermal conductivity of six refrigerants, R12, R14, R32, R115, R143, and R152 was predicted by these methods and the effectiveness of models was specified and compared. Results: The results show that the computational method is a usable method for predicting thermal conductivity at low levels of density. However, the efficiency of this model is considerably reduced in the mid-range of density. It means that this model cannot be used at density levels which are higher than 6. On the other hand, the ANN approach is a reliable method for thermal conductivity prediction in all ranges of density. The best accuracy of ANN is achieved when the number of units is increased in the hidden layer. Conclusion: The results of the computational method indicate that the regular dependence between thermal conductivity and density at higher densities is eliminated. It can develop a nonlinear problem. Therefore, analytical approaches are not able to predict thermal conductivity in wide ranges of density. Instead, a nonlinear approach such as, ANN is a valuable method for this purpose. PMID:29188217

The mechanisms underlying overgeneral autobiographical memory: An evaluative review of evidence for the CaR-FA-X model

PubMed Central

Sumner, Jennifer A.

2011-01-01

Overgeneral autobiographical memory (OGM) has been found to be an important cognitive phenomenon with respect to depression and trauma-related psychopathology (e.g., posttraumatic stress disorder), and researchers have been interested in better understanding the factors that contribute to this proposed vulnerability factor. The most prominent model of mechanisms underlying OGM to date is Williams et al.’s (2007) CaR-FA-X model. This model proposes that three processes influence OGM: capture and rumination, functional avoidance, and impaired executive control. The author reviews the current state of support for the CaR-FA-X model by evaluating 38 studies that have examined OGM and one or more mechanisms of the model. Collectively, these studies reveal robust support for associations between OGM and both rumination and impaired executive control. OGM also appears to be a cognitive avoidance strategy, and there is evidence that avoiding the retrieval of specific memories reduces distress after an aversive event, at least in the short term. Important issues that have been left unresolved are highlighted, including the nature of the capture phenomenon, the role of trauma in functional avoidance, and the developmental nature of functional avoidance. Recommendations for future research that will enhance understanding of the factors that contribute to OGM are suggested. PMID:22142837

Reliability-Centered Maintenance

DTIC Science & Technology

1978-12-29

the pack through a flow-control valve and is cooled and dehumidified by a heat exchanger and the turbine of an air-cycle refrigeration ma- chine. The...dirt, moisture, and heat are the most susceptible to corrosion, and properly applied and maintained protective coatings are necessary to prevent...LFM’TNT i RCJL, ’A~r I ARLCA & WORK JNI- N UMUL R, United Airlines San Francisco International Airport San Francisco, Ca 94128 Office of Assistant

Reversible and irreversible heat engine and refrigerator cycles

NASA Astrophysics Data System (ADS)

Leff, Harvey S.

2018-05-01

Although no reversible thermodynamic cycles exist in nature, nearly all cycles covered in textbooks are reversible. This is a review, clarification, and extension of results and concepts for quasistatic, reversible and irreversible processes and cycles, intended primarily for teachers and students. Distinctions between the latter process types are explained, with emphasis on clockwise (CW) and counterclockwise (CCW) cycles. Specific examples of each are examined, including Carnot, Kelvin and Stirling cycles. For the Stirling cycle, potentially useful task-specific efficiency measures are proposed and illustrated. Whether a cycle behaves as a traditional refrigerator or heat engine can depend on whether it is reversible or irreversible. Reversible and irreversible-quasistatic CW cycles both satisfy Carnot's inequality for thermal efficiency, η ≤ η C a r n o t . Irreversible CCW cycles with two reservoirs satisfy the coefficient of performance inequality K ≤ K C a r n o t . However, an arbitrary reversible cycle satisfies K ≥ K C a r n o t when compared with a reversible Carnot cycle operating between its maximum and minimum temperatures, a potentially counterintuitive result.

Gas hydrate cool storage system

DOEpatents

Ternes, M.P.; Kedl, R.J.

1984-09-12

The invention presented relates to the development of a process utilizing a gas hydrate as a cool storage medium for alleviating electric load demands during peak usage periods. Several objectives of the invention are mentioned concerning the formation of the gas hydrate as storage material in a thermal energy storage system within a heat pump cycle system. The gas hydrate was formed using a refrigerant in water and an example with R-12 refrigerant is included. (BCS)

U.S. EPA, Pesticide Product Label, 20% GRANULAR 2,4-D LOW VOLATILE, 01/14/1994

EPA Pesticide Factsheets

2011-04-14

... 1lI"AiAI '~";PIR'AI UIN wilA '~t5 ,,,sa ... , Vie., 'Y' ,N.,stiaR fI'. Mill" IF .'et,. ... 181, .A" wat.r .5 IIIR iii 'l5&i~l. Itllr ",i.iAI. laa"iAIJ IIF 1"I)I'iAI'''i' ,Fa"W". 'I:'.,h hIA"'. ...

78 FR 3909 - Big Oaks National Wildlife Refuge, IN; Glacial Ridge National Wildlife Refuge, MN; Northern...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-01-17

... DEPARTMENT OF THE INTERIOR Fish and Wildlife Service [FWS-R3-R-2012-N283; FXRS1265030000-134-FF03R06000] Big Oaks National Wildlife Refuge, IN; Glacial Ridge National Wildlife Refuge, MN; Northern Tallgrass Prairie National Wildlife Refuge, MN; Whittlesey Creek National Wildlife Refuge, WI AGENCY: Fish...

Graphic-output temperature data loggers for monitoring vaccine refrigeration: implications for pertussis.

PubMed

McColloster, Patrick; Vallbona, Carlos

2011-01-01

We conducted the first US study using graphic-output temperature data loggers in quantifying cold chain failure. Fifty-four vaccine refrigerators of a county outpatient health system were studied. Forty-eight percent maintained temperatures of 2°C to 8°C and 24% had protracted periods of temperatures less than 0°C. The correlation between the percentage of refrigerators with freezing temperatures and the pertussis rate for each health region was r = 0.76. The findings suggest that improper vaccine storage may have contributed to recent increases in pertussis rates.

Subatmospheric vapor pressures evaluated from internal-energy measurements

NASA Astrophysics Data System (ADS)

Duarte-Garza, H. A.; Magee, J. W.

1997-01-01

Vapor pressures were evaluated from measured internal-energy changes in the vapor+liquid two-phase region, Δ U (2). The method employed a thermodynamic relationship between the derivative quantity (ϖ U (2)/ϖ V) T and the vapor pressure ( p σ) and its temperature derivative (ϖ p/ϖ T)σ. This method was applied at temperatures between the triple point and the normal boiling point of three substances: 1,1,1,2-tetrafluoroethane (R134a), pentafluoroethane (R125), and difluoromethane (R32). Agreement with experimentally measured vapor pressures near the normal boiling point (101.325 kPa) was within the experimental uncertainty of approximately ±0.04 kPa (±0.04%). The method was applied to R134a to test the thermodynamic consistency of a published p-p-T equation of state with an equation for p σ for this substance. It was also applied to evaluate published p σ data which are in disagreement by more than their claimed uncertainty.

Affective traits of psychopathy are linked to white-matter abnormalities in impulsive male offenders.

PubMed

Vermeij, Anouk; Kempes, Maaike M; Cima, Maaike J; Mars, Rogier B; Brazil, Inti A

2018-04-26

Psychopathy is a personality disorder typified by lack of empathy and impulsive antisocial behavior. Psychopathic traits may partly relate to disrupted connections between brain regions. The aim of the present study was to link abnormalities in microstructural integrity of white-matter tracts to the severity of different psychopathic traits in 15 male offenders with impulse control problems and 10 without impulse control problems. Psychopathic traits were assessed using the Psychopathy Checklist-revised (PCL-R). Diffusion-weighted MRI was used to examine white-matter tracts. Fractional anisotropy (FA), an index of white-matter integrity, was calculated for each voxel. Clusters of voxels showing a significant relationship with psychopathy severity were submitted to probabilistic tractography. No significant correlations between psychopathy severity and FA were present in the whole group of impulsive and nonimpulsive offenders. In impulsive offenders, interpersonal-affective traits (PCL-R Factor 1) were negatively correlated with FA in the anterior and posterior temporal lobe and orbitofrontal area. Further analyses indicated that elevated affective traits (PCL-R Facet 2) were specifically related to reduced FA in the right temporal lobe. Our findings suggest that white-matter abnormalities in temporal and frontotemporal tracts may be linked to the interpersonal-affective deficits of psychopathy in offenders with relatively severe impulse control problems. Our study offers novel insights into the relationships between the four facets of psychopathy and disrupted structural connectivity, and may provide new leads for further characterization of different subtypes of antisocial populations. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Remote thalamic microstructural abnormalities related to cognitive function in ischemic stroke patients.

PubMed

Fernández-Andújar, Marina; Doornink, Fleur; Dacosta-Aguayo, Rosalía; Soriano-Raya, Juan José; Miralbell, Júlia; Bargalló, Núria; López-Cancio, Elena; Pérez de la Ossa, Natalia; Gomis, Meritxell; Millán, Mònica; Barrios, Maite; Cáceres, Cynthia; Pera, Guillem; Forés, Rosa; Clemente, Imma; Dávalos, Antoni; Mataró, Maria

2014-11-01

Ischemic stroke can lead to a continuum of cognitive sequelae, ranging from mild vascular cognitive impairment to vascular dementia. These cognitive deficits can be influenced by the disruption of cortico-subcortical circuits. We sought to explore remote thalamic microstructural abnormalities and their association with cognitive function after ischemic stroke. Seventeen patients with right hemispheric ischemic stroke and 17 controls matched for age, sex, and years of education were included. All participants underwent neurological, neuropsychological, and diffusion tensor image examination. Patients were assessed 3 months poststroke. Voxel-wise analysis was used to study thalamic diffusion differences between groups. Mean fractional anisotropy (FA) and mean diffusivity (MD) values in significant thalamic areas were calculated for each subject and correlated with cognitive performance. Stroke patients showed lower FA values and higher MD values in specific areas of both the left and right thalamus compared with controls. In patients, decreased FA values were associated with lower verbal fluency performance in the right thalamus (R(2) = 0.45, β = 0.74) and the left thalamus (R(2) = 0.57, β = 0.77) after adjusting for diabetes mellitus. Moreover, increased MD values were associated with lower verbal fluency performance in the right thalamus (R(2) = 0.27, β = -0.54) after adjusting for diabetes mellitus. In controls, thalamic FA and MD values were not related to any cognitive function. Our findings support the hypothesis that ischemic stroke lesions are associated with remote thalamic diffusion abnormalities, and that these abnormalities can contribute to cognitive dysfunction 3 months after a cerebrovascular event. PsycINFO Database Record (c) 2014 APA, all rights reserved.

Sustained signalling by PTH modulates IP3 accumulation and IP3 receptors through cyclic AMP junctions

PubMed Central

Meena, Abha; Tovey, Stephen C.; Taylor, Colin W.

2015-01-01

ABSTRACT Parathyroid hormone (PTH) stimulates adenylyl cyclase through type 1 PTH receptors (PTH1R) and potentiates the Ca2+ signals evoked by carbachol, which stimulates formation of inositol 1,4,5-trisphosphate (IP3). We confirmed that in HEK cells expressing PTH1R, acute stimulation with PTH(1-34) potentiated carbachol-evoked Ca2+ release. This was mediated by locally delivered cyclic AMP (cAMP), but unaffected by inhibition of protein kinase A (PKA), exchange proteins activated by cAMP, cAMP phosphodiesterases (PDEs) or substantial inhibition of adenylyl cyclase. Sustained stimulation with PTH(1-34) causes internalization of PTH1R–adenylyl cyclase signalling complexes, but the consequences for delivery of cAMP to IP3R within cAMP signalling junctions are unknown. Here, we show that sustained stimulation with PTH(1-34) or with PTH analogues that do not evoke receptor internalization reduced the potentiated Ca2+ signals and attenuated carbachol-evoked increases in cytosolic IP3. Similar results were obtained after sustained stimulation with NKH477 to directly activate adenylyl cyclase, or with the membrane-permeant analogue of cAMP, 8-Br-cAMP. These responses were independent of PKA and unaffected by substantial inhibition of adenylyl cyclase. During prolonged stimulation with PTH(1-34), hyperactive cAMP signalling junctions, within which cAMP is delivered directly and at saturating concentrations to its targets, mediate sensitization of IP3R and a more slowly developing inhibition of IP3 accumulation. PMID:25431134

Generalized equation of state for refrigerants

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, Y.; Sonntag, R.E.; Borgnakke, C.

1995-08-01

A new four-parameter generalized equation of state with three reference fluids has been developed for predicting thermodynamic properties of the methane and ethane-series refrigerants. The four chosen characteristic parameters are critical temperature, critical pressure, acentric factor, and the polarity factor proposed in this work. The three selected reference fluids are argon, n-butane and 1,1-difluoroethane (R-152a). When the results of this work are compared with the refrigerant experimental data, they show significant improvement over Lee and Kesler (1975) and Wu and Stiel (1985). If the characteristic parameters of the refrigerants of interest are not available, an estimation method based on themore » group contribution method is given. The ideal vapor-compression refrigeration cycle was studied using the newly developed generalized equation of state to verify the accuracy of this work.« less

[Design and activity verification of human parathyroid hormone (1-34) mutant protein].

PubMed

Qiu, Shuang; Jiang, Yue-Shui; Li, Zhi-Qin; Lei, Jian-Yong; Chen, Yun; Jin, Jian

2012-07-01

Through protein-protein BLAST of homologous sequences in different species in NCBI database and preliminary simulating molecular docking and molecular dynamics by computer software discovery studio 3.1, three amino acids R25K26K27 of natural human parathyroid hormone (1-34) with Q25E26L27 were mutated and the biological activity of the mutant peptide was evaluated. Result showed that: root mean superposition deviation RMSD value between PTH (1-34)-(RKK-QEL) and PTH (1-34) peptide main chain was 2.509 3, indicating that the differences between the two main chain structural conformation was relatively small; the interaction energy between PTH (1-34)-(RKK-QEL) and its receptor protein PTH1R had been enhanced by 7.5% compared to nature PTH (1-34), from -554.083 kcal x mol(-1) to -599.253 kcal x mol(-1); the number of hydrogen bonds was increased from 32 to 38; PTH (1-34)-(RKK-QEL) can significantly stimulate the RANKL gene expression (P < 0.01) while inhibiting the OPG gene expression (P < 0.01) in UAMS-32P cells; in the co-culture system of UAMS-32P cells and mouse primary femur bone marrow cells, PTH (1-34)-(RKK-QEL) stimulated the formation of osteoclasts (P < 0.01) and had a higher biological activity than PTH (1-34) standard reagents.

Performance Analysis of a Thermoelectric Solar Collector Integrated with a Heat Pump

NASA Astrophysics Data System (ADS)

Lertsatitthanakorn, C.; Jamradloedluk, J.; Rungsiyopas, M.; Therdyothin, A.; Soponronnarit, S.

2013-07-01

A novel heat pump system is proposed. A thermoelectric solar collector was coupled to a solar-assisted heat pump (TESC-HP) to work as an evaporator. The cooling effect of the system's refrigerant allowed the cold side of the system's thermoelectric modules to work at lower temperature, improving the conversion efficiency. The TESC-HP system mainly consisted of transparent glass, an air gap, an absorber plate that acted as a direct expansion-type collector/evaporator, an R-134a piston-type hermetic compressor, a water-cooled plate-type condenser, thermoelectric modules, and a water storage tank. Test results indicated that the TESC-HP has better coefficient of performance (COP) and conversion efficiency than the separate units. For the meteorological conditions in Mahasarakham, the COP of the TESC-HP system can reach 5.48 when the average temperature of 100 L of water is increased from 28°C to 40°C in 60 min with average ambient temperature of 32.5°C and average solar intensity of 815 W/m2, whereas the conversion efficiency of the TE power generator was around 2.03%.

The development of a performance-enhancing additive for vapor-compression heat pumps

DOE Office of Scientific and Technical Information (OSTI.GOV)

Grzyll, L.R.; Scaringe, R.P.; Gottschlich, J.M.

1997-12-31

This paper describes the testing results of a vapor-compression heat pump operating with HFC-134a refrigerant and a performance-enhancing additive. Preliminary bench-top testing of this additive, when added to polyolester (POE) lubricant and HFC-134a refrigerant, showed surprising enhancements to system COP. To further investigate this finding, the authors designed and fabricated a vapor-compression heat pump test stand for the 3--5 ton range. The authors investigated the effect of different concentrations of this additive on various system performance parameters such as cooling capacity, compressor power requirement, pressure ratio, compressor pressure difference, compressor isentropic efficiency, refrigerant flow rate, and heat exchanger performance. Themore » authors investigated various heat source and heat sink conditions to simulate air-conditioning and heat pump operating conditions. To investigate the effect of this additive on compressor lubrication and life, the authors performed compressor life tests (with scroll and reciprocating compressors), and had lubrication wear tests performed with various concentrations of the additive in the POE lubricant.« less

V̇O2 and HR kinetics before and after International Space Station missions.

PubMed

Hoffmann, U; Moore, A D; Koschate, J; Drescher, U

2016-03-01

Heart rate (HR), pulmonary and muscle oxygen uptake ([Formula: see text]O2pulm, [Formula: see text]O2musc) kinetics after changes of work rate (WR) indicate regulatory characteristics related to aerobic metabolism. We analysed whether the kinetics of HR, [Formula: see text]O2pulm and [Formula: see text]O2musc are slowed after missions to the International Space Station (ISS). The changes of the kinetics were correlated with [Formula: see text]O2peak data. 10 astronauts [4 females, 6 males, age: 48.0 ± 3.8 years, height: 176 ± 7 cm, mass: 74.5 ± 15.9 kg (mean ± SD)] performed an incremental test to determine [Formula: see text]O2peak (before missions on L-110 days, after return on R+1/+10/+36 days), and a cardio-respiratory kinetics test (CRKT) with randomized 30-80 W WR changes to determine HR, [Formula: see text]O2pulm and [Formula: see text]O2musc kinetics by time-series analysis (L-236/-73, R+6/+21). Kinetics were summarized by maximum and related lag of cross-correlation function (CCFmax, CCFlag) of WR with the analysed parameter. Statistically, significant changes were also found for CCFmax([Formula: see text]O2musc) between L-236 and R+6 (P = 0.010), L-236 and R+21 (P = 0.030), L-72 and R+6 (P = 0.043). Between pre-to-post mission change in [Formula: see text]O2peak and CCFmax(HR), a correlation was shown (r SP = 0.67, P = 0.017). The [Formula: see text]O2musc kinetics changes indicate aerobic detraining effects which are present up to 21 days following space flight. The correlations between changes in [Formula: see text]O2peak and HR kinetics illustrate the key role of cardiovascular regulation in [Formula: see text]O2peak. The addition of CRKT to ISS flight is recommended to obtain information regarding the potential muscular and cardiovascular deconditioning. This allows a reduction in the frequency of higher intensity testing during flight.

New hydrate formation methods in a liquid-gas medium

NASA Astrophysics Data System (ADS)

Chernov, A. A.; Pil'Nik, A. A.; Elistratov, D. S.; Mezentsev, I. V.; Meleshkin, A. V.; Bartashevich, M. V.; Vlasenko, M. G.

2017-01-01

Conceptually new methods of hydrate formation are proposed. The first one is based on the shock wave impact on a water-bubble medium. It is shown that the hydrate formation rate in this process is typically very high. A gas hydrate of carbon dioxide was produced. The process was experimentally studied using various initial conditions, as well as different external action magnitudes. The obtained experimental data are in good agreement with the proposed model. Other methods are based on the process of boiling liquefied gas in an enclosed volume of water (explosive boiling of a hydrating agent and the organization of cyclic boiling-condensation process). The key features of the methods are the high hydrate formation rate combined with a comparatively low power consumption leading to a great expected efficiency of the technologies based on them. The set of experiments was carried out. Gas hydrates of refrigerant R134a, carbon dioxide and propane were produced. The investigation of decomposition of a generated gas hydrate sample was made. The criteria of intensification of the hydrate formation process are formulated.

New hydrate formation methods in a liquid-gas medium.

PubMed

Chernov, A A; Pil'nik, A A; Elistratov, D S; Mezentsev, I V; Meleshkin, A V; Bartashevich, M V; Vlasenko, M G

2017-01-18

Conceptually new methods of hydrate formation are proposed. The first one is based on the shock wave impact on a water-bubble medium. It is shown that the hydrate formation rate in this process is typically very high. A gas hydrate of carbon dioxide was produced. The process was experimentally studied using various initial conditions, as well as different external action magnitudes. The obtained experimental data are in good agreement with the proposed model. Other methods are based on the process of boiling liquefied gas in an enclosed volume of water (explosive boiling of a hydrating agent and the organization of cyclic boiling-condensation process). The key features of the methods are the high hydrate formation rate combined with a comparatively low power consumption leading to a great expected efficiency of the technologies based on them. The set of experiments was carried out. Gas hydrates of refrigerant R134a, carbon dioxide and propane were produced. The investigation of decomposition of a generated gas hydrate sample was made. The criteria of intensification of the hydrate formation process are formulated.

New hydrate formation methods in a liquid-gas medium

PubMed Central

Chernov, A. A.; Pil’nik, A. A.; Elistratov, D. S.; Mezentsev, I. V.; Meleshkin, A. V.; Bartashevich, M. V.; Vlasenko, M. G.

2017-01-01

Conceptually new methods of hydrate formation are proposed. The first one is based on the shock wave impact on a water-bubble medium. It is shown that the hydrate formation rate in this process is typically very high. A gas hydrate of carbon dioxide was produced. The process was experimentally studied using various initial conditions, as well as different external action magnitudes. The obtained experimental data are in good agreement with the proposed model. Other methods are based on the process of boiling liquefied gas in an enclosed volume of water (explosive boiling of a hydrating agent and the organization of cyclic boiling-condensation process). The key features of the methods are the high hydrate formation rate combined with a comparatively low power consumption leading to a great expected efficiency of the technologies based on them. The set of experiments was carried out. Gas hydrates of refrigerant R134a, carbon dioxide and propane were produced. The investigation of decomposition of a generated gas hydrate sample was made. The criteria of intensification of the hydrate formation process are formulated. PMID:28098194

Consideration of Sludge Formation in HFC-134a / Polyol Ester oil Refrigeration System

NASA Astrophysics Data System (ADS)

Yamamoto, Tsutomu; Yamamoto, Tethuya; Simizu, Yasuhiko; Nakayama, Yoshinori; Takizawa, Kikuo

A refrigeration test employing HFC-134a and polyol ester oil was carried out in order to make clear the causes of the sludge formation in the capillary tube. Compressors used were two types: a hermetic reciprocating compressor and a rotary compressor. Installed dryer contained desiccant of the compound zeolite type. The results showed that the amount of capillary sludge increased as the compressor temperature rose. The capillary sludge was determined to consist of desiccant and metal dust for the reciprocating compressor, and of tar-like substance for the rotary compressor. Thermal stability test which was used to check the degree of deterioration of the ester oil, suggested that the presence of desiccant and high compressor temperature might produce tar-like substance by the break down and polymerization of the ester oil. In addition, it was confirmed that factors affecting the sludge formation were the dirtiness of the refrigeration circuit for the reciprocating compressor, and the presence of desiccant, for the rotary compressor.

Rhodnius prolixus and Rhodnius robustus-like (Hemiptera, Reduviidae) wing asymmetry under controlled conditions of population density and feeding frequency.

PubMed

Márquez, E J; Saldamando-Benjumea, C I

2013-09-01

Habitat change in Rhodnius spp may represent an environmental challenge for the development of the species, particularly when feeding frequency and population density vary in nature. To estimate the effect of these variables in stability on development, the degree of directional asymmetry (DA) and fluctuating asymmetry (FA) in the wing size and shape of R. prolixus and R. robustus-like were measured under laboratory controlled conditions. DA and FA in wing size and shape were significant in both species, but their variation patterns showed both inter-specific and sexual dimorphic differences in FA of wing size and shape induced by nutrition stress. These results suggest different abilities of the genotypes and sexes of two sylvatic and domestic genotypes of Rhodnius to buffer these stress conditions. However, both species showed non-significant differences in the levels of FA between treatments that simulated sylvan vs domestic conditions, indicating that the developmental noise did not explain the variation in wing size and shape found in previous studies. Thus, this result confirm that the variation in wing size and shape in response to treatments constitute a plastic response of these genotypes to population density and feeding frequency.

Waste heat recovery options in a large gas-turbine combined power plant

NASA Astrophysics Data System (ADS)

Upathumchard, Ularee

This study focuses on power plant heat loss and how to utilize the waste heat in energy recovery systems in order to increase the overall power plant efficiency. The case study of this research is a 700-MW natural gas combined cycle power plant, located in a suburban area of Thailand. An analysis of the heat loss of the combustion process, power generation process, lubrication system, and cooling system has been conducted to evaluate waste heat recovery options. The design of the waste heat recovery options depends to the amount of heat loss from each system and its temperature. Feasible waste heat sources are combustion turbine (CT) room ventilation air and lubrication oil return from the power plant. The following options are being considered in this research: absorption chillers for cooling with working fluids Ammonia-Water and Water-Lithium Bromide (in comparison) and Organic Rankine Cycle (ORC) with working fluids R134a and R245fa. The absorption cycles are modeled in three different stages; single-effect, double-effect and half-effect. ORC models used are simple ORC as a baseline, ORC with internal regenerator, ORC two-phase flash expansion ORC and ORC with multiple heat sources. Thermodynamic models are generated and each system is simulated using Engineering Equation Solver (EES) to define the most suitable waste heat recovery options for the power plant. The result will be synthesized and evaluated with respect to exergy utilization efficiency referred as the Second Law effectiveness and net output capacity. Results of the models give recommendation to install a baseline ORC of R134a and a double-effect water-lithium bromide absorption chiller, driven by ventilation air from combustion turbine compartment. The two technologies yield reasonable economic payback periods of 4.6 years and 0.7 years, respectively. The fact that this selected power plant is in its early stage of operation allows both models to economically and effectively perform waste heat recovery during the power plant's life span. Furthermore, the recommendation from this research will be submitted to the Electricity Generating Authority of Thailand (EGAT) for implementation. This study will also be used as an example for other power plants in Thailand to consider waste energy utilization to improve plant efficiency and sustain fuel resources in the future.

Fires. July-September 08

DTIC Science & Technology

2008-07-01

4, we find the addition of C2 warfare (C2W) and nonlethal fires integration to the fires F ire Support is hard, especially if you are stupid.” A...he presented the “Status of the Field Artillery” and the “FA Campaign Plan” during the Fires Seminar a t F o r t Sill, Okla- homa , in June. Why...excellence, at Fort sill, Okla- homa . He served as the Battalion csM of 1st Battalion, 22nd Field Artillery (1-22 FA), 434th FA Brigade, Fort sill; csM of

Migraine in young females with irritable bowel syndrome: still a challenge

PubMed Central

Georgescu, Doina; Reisz, Daniela; Gurban, Camelia Vidita; Georgescu, Liviu Andrei; Ionita, Ioana; Ancusa, Oana Elena; Lighezan, Daniel

2018-01-01

Migraine without aura is frequently reported in female patients with irritable bowel syndrome (IBS), but knowledge about the relationship between these two conditions is still lacking. This study was aimed to explore the particularities of migraine without aura in young female patients with IBS in order to establish a possible link between them. From a cohort of young female patients hospitalized with IBS in the Internal Medicine Department, 30 joined this pilot study, and they were assigned into two groups on the basis of presence or absence of migraine. In this sample, 15 patients have mild to moderate migraine without aura, with a recently taken normal brain scan, and 15 were without migraine. Diseases and conditions not related to migraine and other possible specific female comorbidities were ruled out. Patients undertook a thorough clinical examination in order to assess fibromyalgia (FM) and chronic pelvic pain (CPP), Questionnaires for migraine disability assessment (MIDAS) and generalized anxiety disorder (GAD) were performed. Laboratory testing of blood, urine, and stool were also performed. Optimized lymphocyte proliferation test for food allergy (FA) and a fecal microbiota (microbiological semiquantitative method) for dysbiosis (DB) assessment were performed. Based on the results, migraine-positive group displayed more severe comorbidities: FM (p=0.0002), FA (p=0.0006), CPP (p=0.026), higher scores of anxiety (GAD, p=0.0008), and more severe DB (p=0.0009). We noticed a strong positive correlation between MIDAS and GAD (r=0.83), a good positive correlation between MIDAS and DB (r=0.56), and a moderate positive correlation between MIDAS, FM, and FA (r=0.46 and 0.41). In conclusion, young female patients with IBS and migraine without aura displayed more severe associated issues – anxiety, intestinal DB, FM, FA, and CPP. The severity of migraine correlated well with anxiety range and DB magnitude and moderately with FM and FA. PMID:29302188

Advances in refrigeration and heat transfer engineering

DOE PAGES

Bansal, Pradeep; Cremaschi, Prof. Lorenzo

2015-05-13

This special edition of Science and Technology for the Built Environment (STBE) presents selected high quality papers that were presented at the 15th International Refrigeration and Air Conditioning Conference held at Purdue University during July 14-17 2014. All papers went through the additional review before being finally accepted for publication in this special issue of Science and Technology and the Built Environment. Altogether 20 papers made to this special issue that cover a wide range of topics, including advancements in alternative refrigerants, heat exchangers/heat transfer, nano-fluids, systems design and optimization and modeling approaches. Although CO 2 may perhaps have beenmore » the most researched and popular refrigerant in the past decade, R32 is being seriously considered lately as an alternative and environmentally friendly refrigerant for small systems due to its low Global Warming Potential (GWP).« less

Advances in refrigeration and heat transfer engineering

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bansal, Pradeep; Cremaschi, Prof. Lorenzo

This special edition of Science and Technology for the Built Environment (STBE) presents selected high quality papers that were presented at the 15th International Refrigeration and Air Conditioning Conference held at Purdue University during July 14-17 2014. All papers went through the additional review before being finally accepted for publication in this special issue of Science and Technology and the Built Environment. Altogether 20 papers made to this special issue that cover a wide range of topics, including advancements in alternative refrigerants, heat exchangers/heat transfer, nano-fluids, systems design and optimization and modeling approaches. Although CO 2 may perhaps have beenmore » the most researched and popular refrigerant in the past decade, R32 is being seriously considered lately as an alternative and environmentally friendly refrigerant for small systems due to its low Global Warming Potential (GWP).« less

Crystal structure of 2-(1,3-dioxoindan-2-yl)iso-quinoline-1,3,4-trione.

PubMed

Ghalib, Raza Murad; Chidan Kumar, C S; Hashim, Rokiah; Sulaiman, Othman; Fun, Hoong-Kun

2015-01-01

In the title iso-quinoline-1,3,4-trione derivative, C18H9NO5, the five-membered ring of the indane fragment adopts an envelope conformation with the nitro-gen-substituted C atom being the flap. The planes of the indane benzene ring and the iso-quinoline-1,3,4-trione ring make a dihedral angle of 82.06 (6)°. In the crystal, mol-ecules are linked into chains extending along the bc plane via C-H⋯O hydrogen-bonding inter-actions, enclosing R 2 (2)(8) and R 2 (2)(10) loops. The chains are further connected by π-π stacking inter-ations, with centroid-to-centroid distances of 3.9050 (7) Å, forming layers parallel to the b axis.

Defining and Assessing the Impact to the Combat/Weapon Systems of a Ship Post Major Overhaul

DTIC Science & Technology

2013-06-01

vig ati on...ch  Ra da r ( SP S‐6 7)   Un ne ce ss ary  fo r M iss ion   0 Lik e t o h av e  0.2 5 FA LS E 0 0 Na vig ati on  Da ta  (W SN ‐7 )  Ne ce ss ar y  0.5...E 0 0 Na vig ati on  Di str ibu tio n ( NA VS SI)   Ne ce ss ar y  0.5 Ne ce ss ary   0.5 FA LS E 0 0 Cr itic al  Na vig ati on  D ist rib ut ion

1-[3-(4-Butylpiperidin-1-yl)propyl]-1,2,3,4-tetrahydroquinolin-2-one (77-LH-28-1) as a Model for the Rational Design of a Novel Class of Brain Penetrant Ligands with High Affinity and Selectivity for Dopamine D4 Receptor.

PubMed

Del Bello, Fabio; Bonifazi, Alessandro; Giorgioni, Gianfabio; Cifani, Carlo; Micioni Di Bonaventura, Maria Vittoria; Petrelli, Riccardo; Piergentili, Alessandro; Fontana, Stefano; Mammoli, Valerio; Yano, Hideaki; Matucci, Rosanna; Vistoli, Giulio; Quaglia, Wilma

2018-04-26

In the present article, the M 1 mAChR bitopic agonist 1-[3-(4-butylpiperidin-1-yl)propyl]-1,2,3,4-tetrahydroquinolin-2-one (77-LH-28-1, 1) has been demonstrated to show unexpected D 4 R selectivity over D 2 R and D 3 R and to behave as a D 4 R antagonist. To better understand the structural features required for the selective interaction with the D 4 R and to obtain compounds unable to activate mAChRs, the aliphatic butyl chain and the piperidine nucleus of 1 were modified, affording compounds 2-14. The 4-benzylpiperidine 9 and the 4-phenylpiperazine 12 showed high D 4 R affinity and selectivity not only over the other D 2 -like subtypes, but also over M 1 -M 5 mAChRs. Derivative 12 was also highly selective over some selected off-targets. This compound showed biased behavior, potently and partially activating G i protein and inhibiting β-arrestin2 recruitment in functional studies. Pharmacokinetic studies demonstrated that it was characterized by a relevant brain penetration. Therefore, 12 might be a useful tool to better clarify the role played by D 4 R in disorders in which this subtype is involved.

Ferritin ion channel disorder inhibits Fe(II)/O2 reactivity at distant sites.

PubMed

Tosha, Takehiko; Behera, Rabindra K; Theil, Elizabeth C

2012-11-05

Ferritins, a complex, mineralized, protein nanocage family essential for life, provide iron concentrates and oxidant protection. Protein-based ion channels and Fe(II)/O(2) catalysis initiate conversion of thousands of Fe atoms to caged, ferritin Fe(2)O(3)·H(2)O minerals. The ion channels consist of six helical segments, contributed by 3 of 12 or 24 polypeptide subunits, around the 3-fold cage axes. The channel structure guides entering Fe(II) ions toward multiple, catalytic, diiron sites buried inside ferritin protein helices, ~20 Å away from channel internal exits. The catalytic product, Fe(III)-O(H)-Fe(III), is a mineral precursor; mineral nucleation begins inside the protein cage with mineral growth in the central protein cavity (5-8 nm diameter). Amino acid substitutions that changed ionic or hydrophobic channel interactions R72D, D122R, and L134P increased ion channel structural disorder (protein crystallographic analyses) and increased Fe(II) exit [chelated Fe(II) after ferric mineral reduction/dissolution]. Since substitutions of some channel carboxylate residues diminished ferritin catalysis with no effect on Fe(II) exit, such as E130A and D127A, we investigated catalysis in ferritins with altered Fe(II) exit, R72D, D122R and L134P. The results indicate that simply changing the ionic properties of the channels, as in the R72D variant, need not change the forward catalytic rate. However, both D122R and L134P, which had dramatic effects on ferritin catalysis, also caused larger effects on channel structure and order, contrasting with R72D. All three amino acid substitutions, however, decreased the stability of the catalytic intermediate, diferric peroxo, even though overall ferritin cage structure is very stable, resisting 80 °C and 6 M urea. The localized structural changes in ferritin subdomains that affect ferritin function over long distances illustrate new properties of the protein cage in natural ferritin function and for applied ferritin uses.

Combination of Anti-IGF-1R Antibody A12 and Ionizing Radiation in Upper Respiratory Tract Cancers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Riesterer, Oliver; Yang Qiuan; Raju, Uma

2011-03-15

Purpose: The IGF1/IGF-1R signaling pathway has emerged as a potential determinant of radiation resistance in human cancer cell lines. Therefore we investigated the potency of monoclonal anti-IGF-1R antibody, A12, to enhance radiation response in upper respiratory tract cancers. Methods and Materials: Cell lines were assessed for IGF-1R expression and IGF1-dependent response to A12 or radiation using viability and clonogenic cancer cell survival assays. In vivo response of tumor xenografts to 10 or 20 Gy and A12 (0.25-2 mg x 3) was assessed using growth delay assays. Combined treatment effects were also analyzed by immunohistochemical assays for tumor cell proliferation, apoptosis,more » necrosis, and vascular endothelial growth factor expression at Days 1 and 6 after start of treatment. Results: A12 enhanced the radiosensitivity of HN5 and FaDu head-and-neck carcinomas in vitro (p < 0.05) and amplified the radioresponse of FaDu xenografts in a dose-dependent manner, with enhancement factors ranging from 1.2 to 1.8 (p < 0.01). Immunohistochemical analysis of FaDu xenografts demonstrated that A12 inhibited tumor cell proliferation (p < 0.05) and vascular endothelial growth factor expression. When A12 was combined with radiation, this resulted in apoptosis induction that persisted until 6 days from the start of treatment and in increased necrosis at Day 1 (p < 0.01, respectively). Combined treatment with A12 and radiation resulted in additive or subadditive growth delay in H460 or A549 xenografts, respectively. Conclusions: The results of this study strengthen the evidence for investigating how anti-IGF-1R strategies can be integrated into radiation and radiation-cetuximab regimen in the treatment of cancer of the upper aerodigestive tract cancers.« less

Dietary folate does not significantly affect the intestinal microbiome, inflammation or tumorigenesis in azoxymethane-dextran sodium sulphate-treated mice.

PubMed

MacFarlane, Amanda J; Behan, Nathalie A; Matias, Fernando M G; Green, Judy; Caldwell, Don; Brooks, Stephen P J

2013-02-28

Inflammatory bowel disease (IBD) is a risk factor for the development of colon cancer. Environmental factors including diet and the microflora influence disease outcome. Folate and homocysteine have been associated with IBD-mediated colon cancer but their roles remain unclear. We used a model of chemically induced ulcerative colitis (dextran sodium sulphate (DSS)) with or without the colon carcinogen azoxymethane (AOM) to determine the impact of dietary folic acid (FA) on colonic microflora and the development of colon tumours. Male mice (n 15 per group) were fed a FA-deficient (0 mg/kg), control (2 mg/kg) or FA-supplemented (8 mg/kg) diet for 12 weeks. Folate status was dependent on the diet (P< 0·001) and colitis-induced treatment (P= 0·04) such that mice with colitis had lower circulating folate. FA had a minimal effect on tumour initiation, growth and progression, although FA-containing diets tended to be associated with a higher tumour prevalence in DSS-treated mice (7-20 v. 0%, P= 0·08) and the development of more tumours in the distal colon of AOM-treated mice (13-83% increase, P= 0·09). Folate deficiency was associated with hyperhomocysteinaemia (P< 0·001) but homocysteine negatively correlated with tumour number (r - 0·58, P= 0·02) and load (r - 0·57, P= 0·02). FA had no effect on the intestinal microflora. The present data indicate that FA intake has no or little effect on IBD or IBD-mediated colon cancer in this model and that hyperhomocysteinaemia is a biomarker of dietary status and malabsorption rather than a cause of IBD-mediated colon cancer.

An exploration of diffusion tensor eigenvector variability within human calf muscles.

PubMed

Rockel, Conrad; Noseworthy, Michael D

2016-01-01

To explore the effect of diffusion tensor imaging (DTI) acquisition parameters on principal and minor eigenvector stability within human lower leg skeletal muscles. Lower leg muscles were evaluated in seven healthy subjects at 3T using an 8-channel transmit/receive coil. Diffusion-encoding was performed with nine signal averages (NSA) using 6, 15, and 25 directions (NDD). Individual DTI volumes were combined into aggregate volumes of 3, 2, and 1 NSA according to number of directions. Tensor eigenvalues (λ1 , λ2 , λ3 ), eigenvectors (ε1 , ε2 , ε3 ), and DTI metrics (fractional anisotropy [FA] and mean diffusivity [MD]) were calculated for each combination of NSA and NDD. Spatial maps of signal-to-noise ratio (SNR), λ3 :λ2 ratio, and zenith angle were also calculated for region of interest (ROI) analysis of vector orientation consistency. ε1 variability was only moderately related to ε2 variability (r = 0.4045). Variation of ε1 was affected by NDD, not NSA (P < 0.0002), while variation of ε2 was affected by NSA, not NDD (P < 0.0003). In terms of tensor shape, vector variability was weakly related to FA (ε1 :r = -0.1854, ε2 : ns), but had a stronger relation to the λ3 :λ2 ratio (ε1 :r = -0.5221, ε2 :r = -0.1771). Vector variability was also weakly related to SNR (ε1 :r = -0.2873, ε2 :r = -0.3483). Zenith angle was found to be strongly associated with variability of ε1 (r = 0.8048) but only weakly with that of ε2 (r = 0.2135). The second eigenvector (ε2 ) displayed higher directional variability relative to ε1 , and was only marginally affected by experimental conditions that impacted ε1 variability. © 2015 Wiley Periodicals, Inc.

Temperature and Water Vapor Pressure Effects on the Friction Coefficient of Hydrogenated Diamondlike Carbon Films

DTIC Science & Technology

2009-07-01

FA9550- 04-1-0367. References 1 Erdemir, A., Eryilmaz, O. L., Nilufer, I. B., and Fenske , G. R., 2000, “Syn- thesis of Superlow-Friction Carbon... Fenske , G. R., 2000, “Effect of Source Gas Chemistry on Tribological Performance of Diamond-Like Car- bon Films,” Diamond Relat. Mater., 9, pp. 632–637...ASME J. Tribol., 127, pp. 82–88. 12 Johnson, J. A., Woodford, J. B., Erdemir, A., and Fenske , G. R., 2003, “Near- Surface Characterization of

Assessing Unidimensionality and Differential Item Functioning in Qualifying Examination for Senior Secondary School Students, Osun State, Nigeria

ERIC Educational Resources Information Center

Ajeigbe, Taiwo Oluwafemi; Afolabi, Eyitayo Rufus Ifedayo

2017-01-01

This study assessed unidimensionality and occurrence of Differential Item Functioning (DIF) in Mathematics and English Language items of Osun State Qualifying Examination. The study made use of secondary data. The results showed that OSQ Mathematics (-0.094 = r = 0.236) and English Language items (-0.095 = r = 0.228) were unidimensional. Also,…

78 FR 3911 - Big Stone National Wildlife Refuge, Big Stone and Lac Qui Parle Counties, MN; Final Comprehensive...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-01-17

... DEPARTMENT OF THE INTERIOR Fish and Wildlife Service [FWS-R3-R-2012-N259; FXRS1265030000-134-FF03R06000] Big Stone National Wildlife Refuge, Big Stone and Lac Qui Parle Counties, MN; Final Comprehensive... significant impact (FONSI) for the environmental assessment (EA) for Big Stone National Wildlife Refuge...

78 FR 39310 - Niobrara Confluence and Ponca Bluffs Conservation Areas, NE and SD; Draft Environmental Impact...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-07-01

... DEPARTMENT OF THE INTERIOR Fish and Wildlife Service National Park Service [FWS-R6-R-2013-N132; FXRS1265066CCP0--134-FF06R06000] Niobrara Confluence and Ponca Bluffs Conservation Areas, NE and SD; Draft... Recreational River Headquarters, 508 East 2nd Street, Yankton, SD 57078. Mail: Nick Kaczor, USFWS, Division of...

Microgravity

NASA Image and Video Library

1988-10-24

Mission Specialist George (Pinky) D. Nelson uses a 35 mm camera to photograph a protein crystal grown during the STS-26 Protein Crystal Growth (PCG-II-01) experiment. The protein crystal growth (PCG) carrier is shown deployed from the PCG Refrigerator/Incubator Mocule (R/IM) located in the middeck forward locker. The R/IM contained three Vapor Diffusion Apparatus (VDS) trays (one of which is shown). A total of sixty protein crystal samples were processed during the STS-26 mission.

Rootkit Detection Using a Cross-View Clean Boot Method

DTIC Science & Technology

2013-03-01

FindNextFile: [2] Kernel32.dll 4. SSDTHooks r -- ... CALL NtQueryDirectoryFile 5. Code Patch ing - 6. Layered Driver 4 NtQueryDirectoryFile : 7...NTFS Driver 0 Volume Manger Disk Driver [2] I. Disk Driver r ! J IAT hooks take advantage of function calls in applications [13]. When an...f36e923898161fa7be50810288e2f48a 61 Appendix D: Windows Source Code Windows Batch File @echo o f f py thon walk . py pause shutdown − r − t 0 Walk.py in

La réfrigération des grandes machines supraconductrices

NASA Astrophysics Data System (ADS)

Gistau, Guy

1991-02-01

The large scale superconducting devices which are now in operation for deviation of heavy particles, acceleration of light particles or plasma confinement need very large powers of refrigeration. After a short survewing of the different functions of refrigerators and the special requirements for large units, the paper describes some existing or envisaged cooling systems which have an equivalent cooling power in the range of 5 kW at 4.5 K. Les grands appareils de physique utilisant les supraconducteurs demandent des puissances cryogéniques de plus en plus importantes. Après un examen des fonctions élémentaires assurées par un réfrigérateur liées au cahier des charges spécifique à chaque utilisation, les spécificités des grosses unités de réfrigération (fiabilité, efficacité, flexibilité, automatisme) sont mises en évidence. Les solutions proposées dans plusieurs grands projets nécessitant des puissances froides supérieures à 5 kW à 4,5 K sont discutées.

Thermoelectric refrigerator

NASA Technical Reports Server (NTRS)

Park, Brian V. (Inventor); Smith, Jr., Malcolm C. (Inventor); McGrath, Ralph D. (Inventor); Gilley, Michael D. (Inventor); Criscuolo, Lance (Inventor); Nelson, John L. (Inventor)

1996-01-01

A refrigerator is provided which combines the benefits of superinsulation materials with thermoelectric devices and phase change materials to provide an environmentally benign system that is energy efficient and can maintain relatively uniform temperatures for extended periods of time with relatively low electrical power requirements. The refrigerator includes a thermoelectric assembly having a thermoelectric device with a hot sink and a cold sink. The superinsulation materials include a plurality of vacuum panels. The refrigerator is formed from an enclosed structure having a door. The vacuum panels may be contained within the walls of the enclosed structure and the door. By mounting the thermoelectric assembly on the door, the manufacturer of the enclosed structure is simplified and the overall R rating of the refrigerator increased. Also an electrical motor and propellers may be mounted on the door to assist in the circulation of air to improve the efficiency of the cold sink and the hot sink. A propeller and/or impeller is preferably mounted within the refrigerator to assist in establishing the desired air circulation flow path.

Editor's Highlight: Lower Fractional Anisotropy in the Globus Pallidus of Asymptomatic Welders, a Marker for Long-Term Welding Exposure.

PubMed

Lee, Eun-Young; Flynn, Michael R; Du, Guangwei; Lewis, Mechelle M; Herring, Amy H; Van Buren, Eric; Van Buren, Scott; Kong, Lan; Mailman, Richard B; Huang, Xuemei

2016-09-01

Welding fumes contain several metals including manganese (Mn), iron (Fe), and copper (Cu) that at high exposure may co-influence welding-related neurotoxicity. The relationship between brain accumulation of these metals and neuropathology, especially in welders with subclinical exposure levels, is unclear. This study examined the microstructural integrity of basal ganglia (BG) regions in asymptomatic welders using diffusion tensor imaging (DTI). Subjects with (n = 43) and without (age- and gender-matched controls; n = 31) history of welding were studied. Occupational questionnaires estimated short-term (HrsW; welding hours and E90; cumulative exposure, past 90 days) and long-term (YrsW; total years welding and ELT; cumulative exposure, lifetime) exposure. Whole blood metal levels (Mn, Fe, and Cu) were obtained. Brain MRI pallidal index (PI), R1 (1/T1), and R2* (1/T2*) were measured to estimate Mn and Fe accumulation in BG [caudate, putamen, and globus pallidus (GP)]. DTI was used to assess BG microstructural differences, and related with exposure measurements. When compared with controls, welders had significantly lower fractional anisotropy (FA) in the GP. In welders, GP FA values showed non-linear relationships to YrsW, blood Mn, and PI. GP FA decreased after a critical level of YrsW or Mn was reached, whereas it decreased with increasing PI values until plateauing at the highest PI values. GP FA, however, did not show any relationship with short-term exposure measurements (HrsW, E90), blood Cu and Fe, or R(2)* values. GP FA captured microstructural changes associated with chronic low-level Mn exposure, and may serve as a biomarker for neurotoxicity in asymptomatic welders. © The Author 2016. Published by Oxford University Press on behalf of the Society of Toxicology. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Development of a refrigeration system for lunar surface and spacecraft applications

NASA Technical Reports Server (NTRS)

Copeland, R. J.

1976-01-01

An evaluation of refrigeration devices suitable for potential lunar surface and spacecraft applications was performed. The following conclusions were reached: (1) the vapor compression system is the best overall refrigeration system for lunar surface and spacecraft applications and the single phase radiator system is generally preferred for earth orbit applications, (2) the vapor compression cycle may have some application for simultaneous heating and cooling, (3) a Stirling cycle refrigerator was selected for the manned cabin of the space shuttle, and (4) significant increases in payload heat rejection can be obtained by a kit vapor compression refrigerator added to the shuttle R-21 loop. The following recommendations were made: (1) a Stirling cycle refrigerator may be used for food freezer and biomedical sample storage, (2) the best system for a food freezer/experiments compartment for an earth orbit space station has not been determined, (3) a deployed radiator system can be designed for large heat loads in earth orbit.

Cross-generational trans fat intake modifies BDNF mRNA in the hippocampus: Impact on memory loss in a mania animal model.

PubMed

Trevizol, Fabíola; Dias, Verônica T; Roversi, Katiane; Barcelos, Raquel C S; Kuhn, Fábio T; Roversi, Karine; Pase, Camila S; Golombieski, Ronaldo; Veit, Juliana C; Piccolo, Jaqueline; Emanuelli, Tatiana; Rocha, João B T; Bürger, Marilise E

2015-05-01

Recently, we have described the influence of dietary fatty acids (FA) on mania-like behavior of first generation animals. Here, two sequential generations of female rats were supplemented with soybean oil (SO, rich in n-6 FA, control group), fish oil (FO, rich in n-3 FA) and hydrogenated vegetable fat (HVF, rich in trans FA) from pregnancy and during lactation. In adulthood, half of each group was exposed to an amphetamine (AMPH)-induced mania animal model for behavioral, biochemical and molecular assessments. FO supplementation was associated with lower reactive species (RS) generation and protein carbonyl (PC) levels and increased dopamine transporter (DAT) levels, while HVF increased RS and PC levels, thus decreasing catalase (CAT) activity and DAT levels in hippocampus after AMPH treatment. AMPH impaired short- (1 h) and long- (24 h) term memory in the HVF group. AMPH exposure was able to reduce hippocampal BDNF- mRNA expression, which was increased in FO. While HVF was related to higher trans FA (TFA) incorporation in hippocampus, FO was associated with increased percentage of n-3 polyunsaturated FA (PUFA) together with lower n-6/n-3 PUFA ratio. Interestingly, our data showed a positive correlation between brain-derived neurotrophic factor (BDNF) mRNA and short- and long-term memory (r(2)  = 0.53; P = 0.000/r(2)  = 0.32; P = 0.011, respectively), as well as a negative correlation between PC and DAT levels (r(2)  = 0.23; P = 0.015). Our findings confirm that provision of n-3 or TFA during development over two generations is able to change the neuronal membrane lipid composition, protecting or impairing the hippocampus, respectively, thus affecting neurothrophic factor expression such as BDNF mRNA. In this context, chronic consumption of trans fats over two generations can facilitate the development of mania-like behavior, so leading to memory impairment and emotionality, which are related to neuropsychiatric conditions. © 2014 Wiley Periodicals, Inc.

Word Frequency Analysis. MOS: 33S. Skill Levels 1 & 2.

DTIC Science & Technology

1981-05-01

rts Wq -1A~ ttSttii AArjtr I TF1 P!16 1,1,1 PAGE 1 TV 1" r Y Nsv’r 1 1 - ? I l1 1 , .I I I o ’ , ’’II A T 1T1 1 1 1Ilr A-r P y? A T f TS...TIFl’nfl n ! ’ cVT AT (rhi I nrV I", I n I’I𔃿F𔃻 1 rnIbrrTnn 1 n 19 r (.T I 9 I 1 .. i’r"’r TF1 LIn’I~r I, ItiVsS En 1 OI1;VIa V Cn AV. f" I" I " c,’’’ 1

White Matter Integrity Dissociates Verbal Memory and Auditory Attention Span in Emerging Adults with Congenital Heart Disease.

PubMed

Brewster, Ryan C; King, Tricia Z; Burns, Thomas G; Drossner, David M; Mahle, William T

2015-01-01

White matter disruptions have been identified in individuals with congenital heart disease (CHD). However, no specific theory-driven relationships between microstructural white matter disruptions and cognition have been established in CHD. We conducted a two-part study. First, we identified significant differences in fractional anisotropy (FA) of emerging adults with CHD using Tract-Based Spatial Statistics (TBSS). TBSS analyses between 22 participants with CHD and 18 demographically similar controls identified five regions of normal appearing white matter with significantly lower FA in CHD, and two higher. Next, two regions of lower FA in CHD were selected to examine theory-driven differential relationships with cognition: voxels along the left uncinate fasciculus (UF; a tract theorized to contribute to verbal memory) and voxels along the right middle cerebellar peduncle (MCP; a tract previously linked to attention). In CHD, a significant positive correlation between UF FA and memory was found, r(20)=.42, p=.049 (uncorrected). There was no correlation between UF and auditory attention span. A positive correlation between MCP FA and auditory attention span was found, r(20)=.47, p=.027 (uncorrected). There was no correlation between MCP and memory. In controls, no significant relationships were identified. These results are consistent with previous literature demonstrating lower FA in younger CHD samples, and provide novel evidence for disrupted white matter integrity in emerging adults with CHD. Furthermore, a correlational double dissociation established distinct white matter circuitry (UF and MCP) and differential cognitive correlates (memory and attention span, respectively) in young adults with CHD.

Comparison of oxygen transfer parameters and oxygen demands in bioreactors operated at low and high dissolved oxygen levels.

PubMed

Mines, Richard O; Callier, Matthew C; Drabek, Benjamin J; Butler, André J

2017-03-21

The proper design of aeration systems for bioreactors is critical since it can represent up to 50% of the operational and capital cost at water reclamation facilities. Transferring the actual amount of oxygen needed to meet the oxygen demand of the wastewater requires α- and β-factors, which are used for calculating the actual oxygen transfer rate (AOTR) under process conditions based on the standard oxygen transfer rate (SOTR). The SOTR is measured in tap water at 20°C, 1 atmospheric pressure, and 0 mg L -1 of dissolved oxygen (DO). In this investigation, two 11.4-L bench-scale completely mixed activated process (CMAS) reactors were operated at various solid retention times (SRTs) to ascertain the relationship between the α-factor and SRT, and between the β-factor and SRT. The second goal was to determine if actual oxygen uptake rates (AOURs) are equal to calculated oxygen uptake rates (COURs) based on mass balances. Each reactor was supplied with 0.84 L m -1 of air resulting in SOTRs of 14.3 and 11.5 g O 2 d -1 for Reactor 1 (R-1) and Reactor 2 (R-2), respectively. The estimated theoretical oxygen demands of the synthetic feed to R-1 and R-2 were 6.3 and 21.9 g O 2 d -1 , respectively. R-2 was primarily operated under a dissolved oxygen (DO) limitation and high nitrogen loading to determine if nitrification would be inhibited from a nitrite buildup and if this would impact the α-factor. Nitrite accumulated in R-2 at DO concentrations ranging from 0.50 to 7.35 mg L -1 and at free ammonia (FA) concentrations ranging from 1.34 to 7.19 mg L -1 . Nonsteady-state reaeration tests performed on the effluent from each reactor and on tap water indicated that the α-factor increased as SRT increased. A simple statistical analysis (paired t-test) between AOURs and COURs indicated that there was a statistically significant difference at 0.05 level of significance for both reactors. The ex situ BOD bottle method for estimating AOUR appears to be invalid in bioreactors operated at low DO concentrations (<1.0 mg L -1 ).

Accurate universal parameterization of absorption cross sections III--light systems

NASA Technical Reports Server (NTRS)

Tripathi, R. K.; Cucinotta, F. A.; Wilson, J. W.

1999-01-01

Our prior nuclear absorption cross sections model [R.K. Tripathi, F.A. Cucinotta, J.W. Wilson, Nucl. Instr. and Meth. B 117 (1996) 347; R.K. Tripathi, J.W. Wilson, F.A. Cucinotta, Nucl. Instr. and Meth. B 129 (1997) 11] is extended for light systems (A < or = 4) where either both projectile and target are light particles or one is light particle and the other is medium or heavy nucleus. The agreement with experiment is excellent for these cases as well. Present work in combination with our original model provides a comprehensive picture of absorption cross sections for light, medium and heavy systems. As a result the extended model can reliably be used in all studies where there is a need for absorption cross sections.

'Virgin gas' ban demands user rethink.

PubMed

Baillie, Jonathan

2010-05-01

A-Gas (UK), a leading UK independent blender and distributor of speciality gases and chemicals, says that many users of the highly versatile HCFC 22 (hydrochlorofluorocarbon) refrigerant gas, including hospitals, are still either unaware, or not taking action to address, this year's ban on the use of both virgin R22, and other virgin HCFC refrigerant gases, in equipment such as air conditioning plant. HEJ editor Jonathan Baillie discussed, with senior personnel, the options for existing HCFC users, and discovered that the "virgin" gas ban could present cost-cutting opportunities for those able to purchase new, more energy-efficient plant compatible with the latest replacement hydrofluorocarbon, and other modern refrigerants.

Differentiation of brain infection from necrotic glioblastoma using combined analysis of diffusion and perfusion MRI.

PubMed

Chawla, Sanjeev; Wang, Sumei; Mohan, Suyash; Nasrallah, MacLean; Verma, Gaurav; Brem, Steven; O'Rourke, Donald M; Wolf, Ronald L; Poptani, Harish; Nabavizadeh, S Ali

2018-04-20

Accurate differentiation of brain infections from necrotic glioblastomas (GBMs) may not always be possible on morphologic MRI or on diffusion tensor imaging (DTI) and dynamic susceptibility contrast perfusion-weighted imaging (DSC-PWI) if these techniques are used independently. To investigate the combined analysis of DTI and DSC-PWI in distinguishing brain injections from necrotic GBMs. Retrospective. Fourteen patients with brain infections and 21 patients with necrotic GBMs. 3T MRI, DTI, and DSC-PWI. Parametric maps of mean diffusivity (MD), fractional anisotropy (FA), coefficient of linear (CL), and planar anisotropy (CP) and leakage corrected cerebral blood volume (CBV) were computed and coregistered with postcontrast T 1 -weighted and FLAIR images. All lesions were segmented into the central core and enhancing region. For each region, median values of MD, FA, CL, CP, relative CBV (rCBV), and top 90 th percentile of rCBV (rCBV max ) were measured. All parameters from both regions were compared between brain infections and necrotic GBMs using Mann-Whitney tests. Logistic regression analyses were performed to obtain the best model in distinguishing these two conditions. From the central core, significantly lower MD (0.90 × 10 -3  ± 0.44 × 10 -3 mm 2 /s vs. 1.66 × 10 -3  ± 0.62 × 10 -3 mm 2 /s, P = 0.001), significantly higher FA (0.15 ± 0.06 vs. 0.09 ± 0.03, P < 0.001), and CP (0.07 ± 0.03 vs. 0.04 ± 0.02, P = 0.009) were observed in brain infections compared to those in necrotic GBMs. Additionally, from the contrast-enhancing region, significantly lower rCBV (1.91 ± 0.95 vs. 2.76 ± 1.24, P = 0.031) and rCBV max (3.46 ± 1.41 vs. 5.89 ± 2.06, P = 0.001) were observed from infective lesions compared to necrotic GBMs. FA from the central core and rCBV max from enhancing region provided the best classification model in distinguishing brain infections from necrotic GBMs, with a sensitivity of 91% and a specificity of 93%. Combined analysis of DTI and DSC-PWI may provide better performance in differentiating brain infections from necrotic GBMs. 1 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2018. © 2018 International Society for Magnetic Resonance in Medicine.

Evaluation of HFC 245ca and HFC 236ea as foam blowing agents

NASA Technical Reports Server (NTRS)

Sharpe, Jon; Macarthur, Doug; Kollie, Tom; Graves, Ron; Liu, Matthew; Hendriks, Robert V.

1995-01-01

Hydrochlorofluorocarbon (HCFC) 141b has been selected as the interim blowing agent for use in urethane insulations on NASA's Space Shuttle External Tank. Due to the expected limited commercial lifetime of this material, research efforts at the NASA Thermal Protection Systems Materials Research Laboratory at the Marshall Space Flight Center are now being devoted to the identification and development of alternatives with zero ozone depletion potential. Physical blowing agents identified to date have included hydrocarbons, fluorocarbons, hydrofluoroethers, and more predominantly, hydrofluorocarbons (HFCs). The majority of the HFC evaluations in industry have focused on the more readily available, low boiling candidates such as HFC 134a. Higher boiling HFC candidates that could be handled at ambient conditions and use current processing equipment would be more desirable. This paper will describe results from a research program of two such candidate HFC's performed as a cooperative effort between Martin Marietta Manned Space Systems, the U.S. Environmental Protection Agency, and Oak Ridge National Laboratories. The purpose of this effort was to perform a cursory evaluation of the developmental HFC's 245ca and 236ea as blowing agents in urethane based insulations. These two materials were selected from screening tests of 37 C2, C3, and C4 isomers based on physical properties, atmospheric lifetime, flammability, estimated toxicity, difficulty of synthesis, suitability for dual use as a refrigerant, and other factors. Solubility of the two materials in typical foam components was tested, pour foaming trials were performed, and preliminary data were gathered regarding foam insulation performance.

Which clinical variable influences health-related quality of life the most after spontaneous subarachnoid hemorrhage? Hunt and Hess scale, Fisher score, World Federation of Neurosurgeons score, Brussels coma score, and Glasgow coma score compared.

PubMed

Kapapa, Thomas; Tjahjadi, Martin; König, Ralph; Wirtz, Christian Rainer; Woischneck, Dieter

2013-12-01

To determine the strength of the correlation between the Hunt and Hess scale, Fisher score, Brussels coma score, World Federation of Neurosurgeons score, and Glasgow coma score and health-related quality of life. Evaluable questionnaires from 236 patients (5.6 years [± standard deviation, 2.854 years] on average after hemorrhage) were included in the analysis. Quality of life was documented using the MOS-36 item short form health survey. Because of the ordinal nature of the variables, Kendall tau was used for calculation. Significance was established as P ≤ 0.05. Weak and very weak correlations were found in general (r ≤ 0.28). The strongest correlations were found between the Glasgow coma score and quality of life (r = 0.236, P = 0.0001). In particular, the "best verbal response" achieved the strongest correlations in the comparison, at r = 0.28/P = 0.0001. The Fisher score showed very weak correlations (r = -0.148/P = 0.012). The Brussels coma score (r = -0.216/P = 0.0001), Hunt and Hess scale (r = -0.197/P = 0.0001), and the World Federation of Neurosurgeons score (r = -0.185/P = 0.0001) revealed stronger correlations, especially in terms of the physical aspects of quality of life. The Glasgow coma scale revealed the strongest, and the Fisher score showed the weakest correlations. Thus the Fisher score, as an indicator of the severity of a hemorrhage, has little significance in terms of health-related quality of life. Copyright © 2013 Elsevier Inc. All rights reserved.

Sources of organic carbon for Rimicaris hybisae: Tracing individual fatty acids at two hydrothermal vent fields in the Mid-Cayman rise

NASA Astrophysics Data System (ADS)

Streit, Kathrin; Bennett, Sarah A.; Van Dover, Cindy L.; Coleman, Max

2015-06-01

Hydrothermal vents harbor ecosystems mostly decoupled from organic carbon synthesized with the energy of sunlight (photosynthetic carbon source) but fueled instead by oxidation of reduced compounds to generate a chemosynthetic carbon source. Our study aimed to disentangle photosynthetic and chemosynthetic organic carbon sources for the shrimp species Rimicaris hybisae, a primary consumer presumed to obtain its organic carbon mainly from ectosymbiotic chemoautotrophic bacteria living on its gill cover membrane. To provide ectosymbionts with ideal conditions for chemosynthesis, these shrimp live in dense clusters around vent chimneys; they are, however, also found sparsely distributed adjacent to diffuse vent flows, where they might depend on alternative food sources. Densely and sparsely distributed shrimp were sampled and dissected into abdominal tissue and gill cover membrane, covered with ectosymbiotic bacteria, at two hydrothermal vent fields in the Mid-Cayman rise that differ in vent chemistry. Fatty acids (FA) were extracted from shrimp tissues and their carbon isotopic compositions assessed. The FA data indicate that adult R. hybisae predominantly rely on bacteria for their organic carbon needs. Their FA composition is dominated by common bacterial FA of the n7 family (~41%). Bacterial FA of the n4 FA family are also abundant and found to constitute good biomarkers for gill ectosymbionts. Sparsely distributed shrimp contain fractions of n4 FA in gill cover membranes ~4% lower than densely packed ones (~18%) and much higher fractions of photosynthetic FA in abdominal tissues, ~4% more (compared with 1.6%), suggesting replacement of ectosymbionts along with exoskeletons (molt), while they take up alternative diets of partly photosynthetic organic carbon. Abdominal tissues also contain photosynthetic FA from a second source taken up presumably during an early dispersal phase and still present to c. 3% in adult shrimp. The contribution of photosynthetic carbon to the FA pool of adult R. hybisae is, however, overall small (max. 8%). Significant differences in carbon isotopic values of chemosynthetically derived FA between vent fields suggest that different dominant C fixation pathways are being used.

Cerebellar involvement in essential tremor with and without resting tremor: A Diffusion Tensor Imaging study.

PubMed

Novellino, Fabiana; Nicoletti, Giuseppe; Cherubini, Andrea; Caligiuri, Maria Eugenia; Nisticò, Rita; Salsone, Maria; Morelli, Maurizio; Arabia, Gennarina; Cavalli, Salvatore Maria; Vaccaro, Maria Grazia; Chiriaco, Carmelina; Quattrone, Aldo

2016-06-01

Essential Tremor with resting tremor (rET) is a debated and poorly understood clinical phenotype. Converging evidences show that neurodegeneration of the cerebellum underlies the pathophysiology of ET, but it is not known if cerebellar changes also occurs in patients with rET. The aim of our study was to evaluate cerebellar microstructure in patients with ET with- (rET) and without resting tremor (ETwr) in comparison to healthy controls by MR Diffusion Tensor Imaging (DTI). We studied 67 patients with ET (rET: 29 and ETwr: 38) and 39 age-matched healthy controls (HC). DTI was performed to measure fractional anisotropy (FA) and mean diffusivity (MD) of white and grey matter (WM, GM) in the entire cerebellum and in right and left cerebellar hemispheres. MD was significantly higher in the cerebellar GM of ET total group (10.39 ± 0.87) in comparison with HC (9.90 ± 0.71) (p = 0.0027). Interestingly, MD was significantly different when ETwr (10.48 ± 0.77) were compared with HC (p = 0.0017), whereas a trend toward significance were found between rET (10.29 ± 0.99) and HC (p = 0.067). No differences among groups were found in MD of cerebellar WM and in FA values neither in the WM nor in the GM. Our results demonstrate the presence of microstructural changes in the cerebellum of patients with ET. It is noteworthy that rET showed intermediate values compared to HC and ETwr, suggesting that rET shares part of the pathophysiological mechanisms of ETwr, but cerebellar involvement seems do not fully account for rET. In addition to the cerebellar loops, other networks may play a role in rET pathophysiology. Copyright © 2016 Elsevier Ltd. All rights reserved.

Financial Accounting and Reporting Improvement Concepts.

DTIC Science & Technology

1980-02-01

systems: coordination and nonlro m" f𔃾mannia systems- la_ 20. ABSTRACT (C a tgo *a n Fa.. ’" o I t nce so . y a, den ,A . blok M ) r a n g e p i a n a i...I NOV IS II0II Unclassified .. SECURITY CLSIIAX klq P.9 Dt "’~~~~-- kA ___________ O -eh awa UawOVd tI4A do NOIAV J.JiUV1 AJ|I¥fl*U 2M.0 ontinued J...800 North Quincy Street Arlington, Virginia 22217 r r .ut . o / - .. J .. . r Codes Attention: Dr. Thomas C. Varley Dear Sirs: sp RE: CONTRACT NO. 0014

White matter structural connectivity is associated with sensorimotor function in stroke survivors☆

PubMed Central

Kalinosky, Benjamin T.; Schindler-Ivens, Sheila; Schmit, Brian D.

2013-01-01

Purpose Diffusion tensor imaging (DTI) provides functionally relevant information about white matter structure. Local anatomical connectivity information combined with fractional anisotropy (FA) and mean diffusivity (MD) may predict functional outcomes in stroke survivors. Imaging methods for predicting functional outcomes in stroke survivors are not well established. This work uses DTI to objectively assess the effects of a stroke lesion on white matter structure and sensorimotor function. Methods A voxel-based approach is introduced to assess a stroke lesion's global impact on motor function. Anatomical T1-weighted and diffusion tensor images of the brain were acquired for nineteen subjects (10 post-stroke and 9 age-matched controls). A manually selected volume of interest was used to alleviate the effects of stroke lesions on image registration. Images from all subjects were registered to the images of the control subject that was anatomically closest to Talairach space. Each subject's transformed image was uniformly seeded for DTI tractography. Each seed was inversely transformed into the individual subject space, where DTI tractography was conducted and then the results were transformed back to the reference space. A voxel-wise connectivity matrix was constructed from the fibers, which was then used to calculate the number of directly and indirectly connected neighbors of each voxel. A novel voxel-wise indirect structural connectivity (VISC) index was computed as the average number of direct connections to a voxel's indirect neighbors. Voxel-based analyses (VBA) were performed to compare VISC, FA, and MD for the detection of lesion-induced changes in sensorimotor function. For each voxel, a t-value was computed from the differences between each stroke brain and the 9 controls. A series of linear regressions was performed between Fugl-Meyer (FM) assessment scores of sensorimotor impairment and each DTI metric's log number of voxels that differed from the control group. Results Correlation between the logarithm of the number of significant voxels in the ipsilesional hemisphere and total Fugl-Meyer score was moderate for MD (R2 = 0.512), and greater for VISC (R2 = 0.796) and FA (R2 = 0.674). The slopes of FA (p = 0.0036), VISC (p = 0.0005), and MD (p = 0.0199) versus the total FM score were significant. However, these correlations were driven by the upper extremity motor component of the FM score (VISC: R2 = 0.879) with little influence of the lower extremity motor component (FA: R2 = 0.177). Conclusion The results suggest that a voxel-wise metric based on DTI tractography can predict upper extremity sensorimotor function of stroke survivors, and that supraspinal intraconnectivity may have a less dominant role in lower extremity function. PMID:24179827

Paclitaxel loaded magnetic nanocomposites with folate modified chitosan/carboxymethyl surface; a vehicle for imaging and targeted drug delivery.

PubMed

Bano, Shazia; Afzal, Muhammad; Waraich, Mustansar Mahmood; Alamgir, Khalid; Nazir, Samina

2016-11-20

In this study, Paclitaxel (PTX) containing, bovine serum albumin (BSA) nanoparticles were fabricated via a simple approach. Folic acid (FA) was conjugated to chitosan (CS)/carboxymethyl cellulose (CMC) through an esterification reaction to produce BSA-CS-FA or BSA-CMC-FA conjugates. NiFe 2 O 4 noncore (NFs) and PTX were loaded through a heat treatment and by a diffusion process. NFs-BSA-CS and NFs-BSA-CMC-FA with size of about 80nm, showed superior transversal R 2 relaxation rate of 349 (mM) -1 s -1 along with folate receptor-targeted and magnetically directed functions. NFs-BSA-CS-FA or NFs-BSA-CS-FA were found stable and biocompatible. Application of an external magnetic field effectively enhanced the PTX release from PTX-NFs-BSA-CS-FA or PTX-NFs-BSA-CS-FA and hence tumor inhibition rate. This study validate that NFs-BSA-CS-FA or NFs-BSA-CMC-FA and PTX-NFs-BSA-CS-FA or PTX-NFs-BSA-CS-FA are suitable systems for tumor diagnosis and therapy. Copyright © 2016. Published by Elsevier B.V.

Design, installation and operating experience of 20 photovoltaic medical refrigerator systems on four continents

NASA Technical Reports Server (NTRS)

Hein, G. F.

1982-01-01

The NASA Lewis Research Center in cooperation with the World Health Organization, U.S.A. I.D., the Pan American Health Organization and national government agencies in some developing countries sponsored the installation of twenty photovoltaic powered medical vaccine storage refrigerator-freezer (R/F) systems. The Solar Power Corporation was selected as the contractor to perform the design, development and installation of these twenty units. Solar Power's experiences are described herein.

Investigation of Light-Emitting Diode (LED) Point Light Source Color Visibility against Complex Multicolored Backgrounds

DTIC Science & Technology

2017-11-01

sent from light-emitting diodes (LEDs) of 5 colors ( green , red, white, amber, and blue). Experiment 1 involved controlled laboratory measurements of...A-4 Red LED calibration curves and quadratic curve fits with R2 values . 37 Fig. A-5 Green LED calibration curves and quadratic curve fits with R2...36 Table A-4 Red LED calibration measurements ................................................... 36 Table A-5 Green LED

Cryogenics for the MuCool Test Area (MTA)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Darve, Christine; Norris, Barry; Pei, Liu-Jin

2005-09-01

MuCool Test Area (MTA) is a complex of buildings at Fermi National Accelerator Laboratory, which are dedicated to operate components of a cooling cell to be used for Muon Collider and Neutrino Factory R&D. The long-term goal of this facility is to test ionization cooling principles by operating a 25-liter liquid hydrogen (LH{sub 2}) absorber embedded in a 5 Tesla superconducting solenoid magnet. The MTA solenoid magnet will be used with RF cavities exposed to a high intensity beam. Cryogens used at the MTA include LHe, LN{sub 2} and LH{sub 2}. The latter dictates stringent system design for hazardous locations.more » The cryogenic plant is a modified Tevatron refrigerator based on the Claude cycle. The implementation of an in-house refrigerator system and two 300 kilowatt screw compressors is under development. The helium refrigeration capacity is 500 W at 14 K. In addition the MTA solenoid magnet will be batch-filled with LHe every 2 days using the same cryo-plant. This paper reviews cryogenic systems used to support the Muon Collider and Neutrino Factory R&D programs and emphasizes the feasibility of handling cryogenic equipment at MTA in a safe manner.« less

Cryogenics for the MuCool Test Area (MTA)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Darve, Christine; Norris, Barry; Pei, Liujin

2006-03-20

MuCool Test Area (MTA) is a complex of buildings at Fermi National Accelerator Laboratory, which are dedicated to operate components of a cooling cell to be used for Muon Collider and Neutrino Factory R and D. The long-term goal of this facility is to test ionization cooling principles by operating a 25-liter liquid hydrogen (LH2) absorber embedded in a 5 Tesla superconducting solenoid magnet. The MTA solenoid magnet will be used with RF cavities exposed to a high intensity beam. Cryogens used at the MTA include LHe, LN2 and LH2. The latter dictates stringent system design for hazardous locations. Themore » cryogenic plant is a modified Tevatron refrigerator based on the Claude cycle. The implementation of an in-house refrigerator system and two 300 kilowatt screw compressors is under development. The helium refrigeration capacity is 500 W at 14 K. In addition the MTA solenoid magnet will be batch-filled with LHe every 2 days using the same cryo-plant. This paper reviews cryogenic systems used to support the Muon Collider and Neutrino Factory R and D programs and emphasizes the feasibility of handling cryogenic equipment at MTA in a safe manner.« less

The mechanisms underlying overgeneral autobiographical memory: an evaluative review of evidence for the CaR-FA-X model.

PubMed

Sumner, Jennifer A

2012-02-01

Overgeneral autobiographical memory (OGM) has been found to be an important cognitive phenomenon with respect to depression and trauma-related psychopathology (e.g., posttraumatic stress disorder), and researchers have been interested in better understanding the factors that contribute to this proposed vulnerability factor. The most prominent model of mechanisms underlying OGM to date is Williams et al.'s (2007) CaR-FA-X model. This model proposes that three processes influence OGM: capture and rumination, functional avoidance, and impaired executive control. The author reviews the current state of support for the CaR-FA-X model by evaluating 38 studies that have examined OGM and one or more mechanisms of the model. Collectively, these studies reveal robust support for associations between OGM and both rumination and impaired executive control. OGM also appears to be a cognitive avoidance strategy, and there is evidence that avoiding the retrieval of specific memories reduces distress after an aversive event, at least in the short term. Important issues that have been left unresolved are highlighted, including the nature of the capture phenomenon, the role of trauma in functional avoidance, and the developmental nature of functional avoidance. Recommendations for future research that will enhance understanding of the factors that contribute to OGM are suggested. Copyright © 2011 Elsevier Ltd. All rights reserved.

Coordinated Optimization of Aircraft Routes and Locations of Ground Sensors

DTIC Science & Technology

2014-09-17

d U γ P p w dw    r sr s , (6) where γ is the detection threshold determined from the following equa- tion for some given faP : ( )( ) ,fa N γ...normal with the mean Uμ 7 and variance Uσ  2 3 . Suppose, the threshold for the false alarm is faP  410 . Then, from equation (7), .γ6 7190 ; and...functions; and the joint probability of false alarm would be ( , ) faP     s s 4 4 81 2 10 10 10 whereas the joint probabil- ity of detection would

Going...Going...Green.

ERIC Educational Resources Information Center

Crowther, Hugh

2002-01-01

Discusses how the mandated phasing out of the most common refrigerant, HCFC R-22, will affect future cooling-system decisions for schools. Address the relevant legislation, environmental implications, possible coolant replacements, and retrofitting systems. (EV)

Design of a Facility to Implement a Low Cost Process for Production of NHC

DTIC Science & Technology

1979-05-15

CO4PANY V. i In brief, crude NHC is produced by sequential batch- wise solution processing, initially converting BIO to the sulfide ligand with subsequent...L 1.03 50 214 R-3 (Dibutyl Sulfide ) L 0.84 -112 360 R-4 (Pyridine) L 0.98 - 44 240 1-Octyne L 0.75 -110 260 Acetone L 0.79 -138 134 Methanol L 0.79...R3 -- 25-Octyne- 300 C5 30 TOL 4 NHC -AREA 40 LEGEND: 82 - Diborane R2 - Dioxane B10 - Decaborane R3 - Butyl Sulfide C5 - Pentane MEOH - Methanol C6

Hispanics of a San Diego Barrio.

DTIC Science & Technology

1983-04-01

1973. Padilla, E . Up from Puerto Rico. New York: Columbia University Press, 1958, 1964. Redfield, R . Peasant society and culture, an anthropological...U6II~’ E - - - -- - -ell-,.~IjO@I~~j N NN N N N N N N N %104%0 x x 0 *0 t. .- 4 Ix X . K K 01 auvj’x x 4.’ 4* . - x- - Q .1 0. . 0 --I---- q5K 1 U4 R ...Performance (Code 44)Naval Material Command Naval Medical R &D Command MAT-03 National Naval Medical Center (J. E . Colvard) Bethesda, MD 20014 Room 236

Architecture as a Diplomatic Tool: A Proposal for the New American Embassy in Baghdad, Iraq

DTIC Science & Technology

2006-04-01

133 William J. R. Curtis, Modern Architecture Since 1900, 3 ed. (New York: Phaidon , 1996) 295-96. 134 Curtis 296. 135 Curtis...Dover, 1986. Curtis, William J. R. Modern Architecture Since 1900. 3d ed. New York: Phaidon , 1996. De Quincy, Quatremère. The True, the Fictive

Step-by-step design of a single phase 3.3 kV/200 a resistive type superconducting fault current limiter (R-SFCL) and cryostat

NASA Astrophysics Data System (ADS)

Kar, Soumen; Rao, V. V.

2018-07-01

In our first attempt to design a single phase R-SFCL in India, we have chosen the typical rating of a medium voltage level (3.3 kVrms, 200 Arms, 1Φ) R-SFCL. The step-by-step design procedure for the R-SFCL involves conductor selection, time dependent electro-thermal simulations and recovery time optimization after fault removal. In the numerical analysis, effective fault limitation for a fault current of 5 kA for the medium voltage level R-SFCL are simulated. Maximum normal state resistance and maximum temperature rise in the SFCL coil during current limitation are estimated using one-dimensional energy balance equation. Further, a cryogenic system is conceptually designed for aforesaid MV level R-SFCL by considering inner and outer vessel materials, wall-thickness and thermal insulation which can be used for R-SFCL system. Finally, the total thermal load is calculated for the designed R-SFCL cryostat to select a suitable cryo-refrigerator for LN2 re-condensation.

Histology-specific microRNA alterations in melanoma.

PubMed

Poliseno, Laura; Haimovic, Adele; Segura, Miguel F; Hanniford, Douglas; Christos, Paul J; Darvishian, Farbod; Wang, Jinhua; Shapiro, Richard L; Pavlick, Anna C; Berman, Russell S; Hernando, Eva; Zavadil, Jiri; Osman, Iman

2012-07-01

We examined the microRNA signature that distinguishes the most common melanoma histological subtypes, superficial spreading melanoma (SSM) and nodular melanoma (NM). We also investigated the mechanisms underlying the differential expression of histology-specific microRNAs. MicroRNA array performed on a training cohort of 82 primary melanoma tumors (26 SSM, 56 NM), and nine congenital nevi (CN) revealed 134 microRNAs differentially expressed between SSM and NM (P<0.05). Out of 134 microRNAs, 126 remained significant after controlling for thickness and 31 were expressed at a lower level in SSM compared with both NM and CN. For seven microRNAs (let-7g, miR-15a, miR-16, miR-138, miR-181a, miR-191, and miR-933), the downregulation was associated with selective genomic loss in SSM cell lines and primary tumors, but not in NM cell lines and primary tumors. The lower expression level of six out of seven microRNAs in SSM compared with NM was confirmed by real-time PCR on a subset of cases in the training cohort and validated in an independent cohort of 97 melanoma cases (38 SSM, 59 NM). Our data support a molecular classification in which SSM and NM are two molecularly distinct phenotypes. Therapeutic strategies that take into account subtype-specific alterations might improve the outcome of melanoma patients.

Histology-Specific MicroRNA Alterations in Melanoma

PubMed Central

Poliseno, Laura; Haimovic, Adele; Segura, Miguel F.; Hanniford, Douglas; Christos, Paul J.; Darvishian, Farbod; Wang, Jinhua; Shapiro, Richard L.; Pavlick, Anna C.; Berman, Russell S.; Hernando, Eva; Zavadil, Jiri; Osman, Iman

2013-01-01

We examined the microRNA signature that distinguishes the most common melanoma histological subtypes, superficial spreading melanoma (SSM) and nodular melanoma (NM). We also investigated the mechanisms underlying the differential expression of histology-specific microRNAs. MicroRNA array performed on a training cohort of 82 primary melanoma tumors (26 SSM, 56 NM), and nine congenital nevi (CN) revealed 134 microRNAs differentially expressed between SSM and NM (P<0.05). Out of 134 microRNAs, 126 remained significant after controlling for thickness and 31 were expressed at a lower level in SSM compared with both NM and CN. For seven microRNAs (let-7g, miR-15a, miR-16, miR-138, miR-181a, miR-191, and miR-933), the downregulation was associated with selective genomic loss in SSM cell lines and primary tumors, but not in NM cell lines and primary tumors. The lower expression level of six out of seven microRNAs in SSM compared with NM was confirmed by real-time PCR on a subset of cases in the training cohort and validated in an independent cohort of 97 melanoma cases (38 SSM, 59 NM). Our data support a molecular classification in which SSM and NM are two molecularly distinct phenotypes. Therapeutic strategies that take into account subtype-specific alterations might improve the outcome of melanoma patients. PMID:22551973

Bibliography of Aircraft Gust Measurements in Australia and of Some Related Topics,

DTIC Science & Technology

1981-09-01

Kf 1972a BUREAU OF METEOROLOGY f/Kf 1972b BUREAU OF METEOROLOGY I/K 1975 BUREAU OF METEOROLOGY f/ T 1977 BUREAU OF METEOROLOGY 1968 BURNHAM, J . 1973...I/Bf 1967 FODEN, P.J. 1977 FREEMAN, W. B. Jr I/RI 1970 FUJITA, T . T . f/Sf 1972 FUJITA, T . T . I/Sf 1977 GARRATT, J.R. f/W/Xf 1969 GENTILLI, J . I/Mf...1956 TROUP, A.J. 1964 KAMIKO, T . 1969 GENTILLI, J . 1970 BERSON, F.A. & LAMOND, M.H. 1972a WARNER, J . 1975 WALKER, D.R. 1976 CHRISTIE, D.R., MUIRHEAr

On the Probability Density Function of the Crest to Trough Heights of Waves and on the Physics of Extreme Waves Including Results from Hurricane Camille.

DTIC Science & Technology

1984-03-01

C; P PA ?A. 4~ 1 7* 1 ~1 P 4 t 3* r (4 ~ ~~ P; CA~~ ~ I", 3 ~ 1 1 4 rAj 3 ?!2 ’A~ P~ FA1 1 ? 2 ’A ?I P11 1 SrFP PIOPARTI.TTY q ;(A ’.1 𔃻 f4 .9iri...Goodman, S. Kaplan , E. Mehr, W. J. Pierson, R. Stevens and L. J. Tick (1958): Theoretical and observed results for the zero and ordinate crossing problems

Effects of HCM cTnI Mutation R145G on Troponin Structure and Modulation by PKA Phosphorylation Elucidated by Molecular Dynamics Simulations

PubMed Central

Lindert, Steffen; Cheng, Yuanhua; Kekenes-Huskey, Peter; Regnier, Michael; McCammon, J. Andrew

2015-01-01

Cardiac troponin (cTn) is a key molecule in the regulation of human cardiac muscle contraction. The N-terminal cardiac-specific peptide of the inhibitory subunit of troponin, cTnI (cTnI1-39), is a target for phosphorylation by protein kinase A (PKA) during β-adrenergic stimulation. We recently presented evidence indicating that this peptide interacts with the inhibitory peptide (cTnl137–147) when S23 and S24 are phosphorylated. The inhibitory peptide is also the target of the point mutation cTnI-R145G, which is associated with hypertrophic cardiomyopathy (HCM), a disease associated with sudden death in apparently healthy young adults. It has been shown that both phosphorylation and this mutation alter the cTnC-cTnI (C-I) interaction, which plays a crucial role in modulating contractile activation. However, little is known about the molecular-level events underlying this modulation. Here, we computationally investigated the effects of the cTnI-R145G mutation on the dynamics of cTn, cTnC Ca2+ handling, and the C-I interaction. Comparisons were made with the cTnI-R145G/S23D/S24D phosphomimic mutation, which has been used both experimentally and computationally to study the cTnI N-terminal specific effects of PKA phosphorylation. Additional comparisons between the phosphomimic mutations and the real phosphorylations were made. For this purpose, we ran triplicate 150 ns molecular dynamics simulations of cTnI-R145G Ca2+-bound cTnC1-161-cTnI1-172-cTnT236-285, cTnI-R145G/S23D/S24D Ca2+-bound cTnC1-161-cTnI1-172-cTnT236-285, and cTnI-R145G/PS23/PS24 Ca2+-bound cTnC1-161-cTnI1-172-cTnT236-285, respectively. We found that the cTnI-R145G mutation did not impact the overall dynamics of cTn, but stabilized crucial Ca2+-coordinating interactions. However, the phosphomimic mutations increased overall cTn fluctuations and destabilized Ca2+ coordination. Interestingly, cTnI-R145G blunted the intrasubunit interactions between the cTnI N-terminal extension and the cTnI inhibitory peptide, which have been suggested to play a crucial role in modulating troponin function during β-adrenergic stimulation. These findings offer a molecular-level explanation for how the HCM mutation cTnI-R145G reduces the modulation of cTn by phosphorylation of S23/S24 during β-adrenergic stimulation. PMID:25606687

Effects of HCM cTnI mutation R145G on troponin structure and modulation by PKA phosphorylation elucidated by molecular dynamics simulations.

PubMed

Lindert, Steffen; Cheng, Yuanhua; Kekenes-Huskey, Peter; Regnier, Michael; McCammon, J Andrew

2015-01-20

Cardiac troponin (cTn) is a key molecule in the regulation of human cardiac muscle contraction. The N-terminal cardiac-specific peptide of the inhibitory subunit of troponin, cTnI (cTnI(1-39)), is a target for phosphorylation by protein kinase A (PKA) during β-adrenergic stimulation. We recently presented evidence indicating that this peptide interacts with the inhibitory peptide (cTnl(137-147)) when S23 and S24 are phosphorylated. The inhibitory peptide is also the target of the point mutation cTnI-R145G, which is associated with hypertrophic cardiomyopathy (HCM), a disease associated with sudden death in apparently healthy young adults. It has been shown that both phosphorylation and this mutation alter the cTnC-cTnI (C-I) interaction, which plays a crucial role in modulating contractile activation. However, little is known about the molecular-level events underlying this modulation. Here, we computationally investigated the effects of the cTnI-R145G mutation on the dynamics of cTn, cTnC Ca(2+) handling, and the C-I interaction. Comparisons were made with the cTnI-R145G/S23D/S24D phosphomimic mutation, which has been used both experimentally and computationally to study the cTnI N-terminal specific effects of PKA phosphorylation. Additional comparisons between the phosphomimic mutations and the real phosphorylations were made. For this purpose, we ran triplicate 150 ns molecular dynamics simulations of cTnI-R145G Ca(2+)-bound cTnC(1-161)-cTnI(1-172)-cTnT(236-285), cTnI-R145G/S23D/S24D Ca(2+)-bound cTnC(1-161)-cTnI(1-172)-cTnT(236-285), and cTnI-R145G/PS23/PS24 Ca(2+)-bound cTnC(1-161)-cTnI(1-172)-cTnT(236-285), respectively. We found that the cTnI-R145G mutation did not impact the overall dynamics of cTn, but stabilized crucial Ca(2+)-coordinating interactions. However, the phosphomimic mutations increased overall cTn fluctuations and destabilized Ca(2+) coordination. Interestingly, cTnI-R145G blunted the intrasubunit interactions between the cTnI N-terminal extension and the cTnI inhibitory peptide, which have been suggested to play a crucial role in modulating troponin function during β-adrenergic stimulation. These findings offer a molecular-level explanation for how the HCM mutation cTnI-R145G reduces the modulation of cTn by phosphorylation of S23/S24 during β-adrenergic stimulation. Copyright © 2015 Biophysical Society. Published by Elsevier Inc. All rights reserved.

Ultrasonic Non-Destructive Testing of Materials.

DTIC Science & Technology

1980-12-01

k IRIT ’F 1"--A ’I I T . 5 1 ~ Ii I I REPORT DOCUMENTATION PAGE CI- N1Il) I EI. i 0.0 REPORT NUMI3ER i2 GOVT ACCA [. ASINN ,NL t PjAi AFOSR.TR. 80...Peport 107r) thait thi rax!’ t -r lqtionn liron whic-h the- F1 . (.)wan based, was a conseaiencr’ of caal it-"’: -and- ioolniv nd whethe.r suc h ai relation

Energy Storage Analysis of a Mixed R161/MOF-5 Nanoparticle Nanofluid Based on Molecular Simulations

PubMed Central

Wang, Qiang; Tang, Shengli; Li, Leilei

2018-01-01

The thermal properties of refrigerants can be modified by adding porous nanoparticles into them. Here, molecular simulations, including molecular dynamics and grand canonical Monte Carlo, were employed to study the thermal energy storage properties of an R161/MOF-5 nanofluid. The results show that the thermodynamic energy change of MOF-5 nanoparticles is linear to the temperature. The adsorption heat calculated by grand canonical Monte Carlo is close to that calculated by the Clausius–Clapeyron equation. Additionally, a negative enhancement of the thermal energy storage capacity of the R161/MOF-5 nanofluid is found near the phase transition area. PMID:29783773

Energy Storage Analysis of a Mixed R161/MOF-5 Nanoparticle Nanofluid Based on Molecular Simulations.

PubMed

Wang, Qiang; Tang, Shengli; Li, Leilei

2018-05-20

The thermal properties of refrigerants can be modified by adding porous nanoparticles into them. Here, molecular simulations, including molecular dynamics and grand canonical Monte Carlo, were employed to study the thermal energy storage properties of an R161/MOF-5 nanofluid. The results show that the thermodynamic energy change of MOF-5 nanoparticles is linear to the temperature. The adsorption heat calculated by grand canonical Monte Carlo is close to that calculated by the Clausius⁻Clapeyron equation. Additionally, a negative enhancement of the thermal energy storage capacity of the R161/MOF-5 nanofluid is found near the phase transition area.

Human Engineering Aspects of a Deep Dive Facility.

DTIC Science & Technology

1977-03-01

Whit" Sectin " DDC Buff S ection r UNANNO¶!’CV D r , JUSTI’ IC .", ,",ON ........ .. . . . . . . . . ............................... DYIlSIRIDtI !fla...would consist mainly of coffee, tea, hot chocolate, or soup and cookies , crackers or other dried food that can be kept without refrigeration. It is...should be used in the Living Chamber. Age..-.. . • :YLi 13 The final recommended decor is based on the use of three basic shades: cream (Munsell 5Y 9/1

Reproducibility, temporal stability, and functional correlation of diffusion MR measurements within the spinal cord in patients with asymptomatic cervical stenosis or cervical myelopathy.

PubMed

Ellingson, Benjamin M; Salamon, Noriko; Woodworth, Davis C; Yokota, Hajime; Holly, Langston T

2018-05-01

OBJECTIVE The purpose of this study was to quantify the reproducibility, temporal stability, and functional correlation of diffusion MR characteristics in the spinal cord in patients with cervical stenosis with or without myelopathy. The association between longitudinal diffusion tensor imaging (DTI) measurements and serial neurological function assessment was explored at both the group and individual level. METHODS Sixty-six nonoperatively treated patients with cervical stenosis were prospectively followed (3 months to > 5 years) using synchronous serial MRI and functional outcome assessment. A total of 183 separate MRI examinations were performed, separated by at least 3 months, and each patient had a minimum of 2 MRI scans (range 2-5 scans). Anatomical and DTI measurements were performed within the spinal cord at the C1-2 region as well as at the area of highest compression. Coefficients of variance (COVs) were compared across measurements in both reference tissue and areas of compression for anatomical measurements, fractional anisotropy (FA), and mean diffusivity (MD). The correlation between diffusion MR measures at the site of compression and evaluations of neurological function assessed using the modified Japanese Orthopaedic Association (mJOA) scale at multiple time points was evaluated. RESULTS The COVs for anatomical measurements (Torg ratio and canal diameter) were between 7% and 10%. The median COV for FA measurements at the site of compression was 9%, and for reference tissue at C1-2 it was 6%. The median COV for MD at the site of compression was approximately 12%, and for reference tissue at C1-2 it was 10%. The FA and MD measurements of C1-2 averaged 0.61 and 0.91 μm 2 /msec, respectively, whereas the FA and MD measurements at the site of compression averaged 0.51 and 1.26 μm 2 /msec, respectively. Both FA (slope = 0.037; R 2 = 0.3281, p < 0.0001) and MD (slope = -0.074; R 2 = 0.1101, p = 0.0084) were significantly correlated with the mJOA score. The FA decreased by approximately 0.032 units per mJOA unit decrease (R 2 = 0.2037, p < 0.0001), whereas the MD was increased by approximately 0.084 μm 2 /msec for every mJOA unit decrease (R 2 = 0.1016, p < 0.0001). CONCLUSIONS Quantitative DTI measurements of the spinal cord in patients with cervical stenosis with or without myelopathy have a median COV of 5%-10%, similar to anatomical measurements. The reproducibility of these measurements and significant correlation with functional outcome status suggest a potential role in the evaluation and longitudinal surveillance of nonoperatively treated patients. With respect to the specific DTI measurements, FA within the spinal cord appears slightly more sensitive to neurological function and more stable than measures of MD. Therefore, DTI of the spinal cord may be a clinically feasible imaging technique for longitudinally monitoring patients with cervical spondylotic myelopathy.

Novel internal regulators and candidate miRNAs within miR-379/miR-656 miRNA cluster can alter cellular phenotype of human glioblastoma.

PubMed

Nayak, Subhashree; Aich, Meghali; Kumar, Anupam; Sengupta, Suman; Bajad, Prajakta; Dhapola, Parashar; Paul, Deepanjan; Narta, Kiran; Purkrait, Suvendu; Mehani, Bharati; Suri, Ashish; Chakraborty, Debojyoti; Mukhopadhyay, Arijit; Sarkar, Chitra

2018-05-16

Clustered miRNAs can affect functioning of downstream pathways due to possible coordinated function. We observed 78-88% of the miR-379/miR-656 cluster (C14MC) miRNAs were downregulated in three sub-types of diffuse gliomas, which was also corroborated with analysis from The Cancer Genome Atlas (TCGA) datasets. The miRNA expression levels decreased with increasing tumor grade, indicating this downregulation as an early event in gliomagenesis. Higher expression of the C14MC miRNAs significantly improved glioblastioma prognosis (Pearson's r = 0.62; p < 3.08e-22). ENCODE meta-data analysis, followed by reporter assays validated existence of two novel internal regulators within C14MC. CRISPR activation of the most efficient internal regulator specifically induced members of the downstream miRNA sub-cluster and apoptosis in glioblastoma cells. Luciferase assays validated novel targets for miR-134 and miR-485-5p, two miRNAs from C14MC with the most number of target genes relevant for glioma. Overexpression of miR-134 and miR-485-5p in human glioblastoma cells suppressed invasion and proliferation, respectively. Furthermore, apoptosis was induced by both miRs, individually and in combination. The results emphasize the tumor suppressive role of C14MC in diffuse gliomas, and identifies two specific miRNAs with potential therapeutic value and towards better disease management and therapy.

Pakistan’s Nuclear Future: Worries Beyond War

DTIC Science & Technology

2008-01-01

sources such as cobalt irradiation sources , neutron sources , etc. that could be utilized by experienced...Kh an AQ K ha n o ffe r t o I ra q Pr es sle r s an cti on s ( Oc t.) 19 91 Gh ula m Ish aq K ha n Na wa z S ha rif Mi rza A sla m Be g ( Ja nu...or th Ko re a ( De c.) 19 94 Fa ro oq Le gh ar i Be na zir B hu tto Ab du l W ah id Ka ka r Se

HVAC (heating, ventilation, air conditioning) literature in Japan: A critical review

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hane, G.J.

1988-02-01

Japanese businessmen in the heating, ventilation, air conditioning, and refrigeration (HVACandR) industry consider the monitoring of technical and market developments in the United States to be a normal part of their business. In contrast, efforts by US businessmen to monitor Japanese HVAC and R developments are poorly developed. To begin to redress this imbalance, this report establishes the groundwork for a more effective system for use in monitoring Japanese HVAC and R literature. Discussions of a review of the principal HVAC and R publications in Japan and descriptions of the type of information contained in each of those publications aremore » included in this report. Since the Japanese HVAC and R literature is abundant, this report also provides practical suggestions on how a researcher or research manager can limit the monitoring effort to the publications and type of information that would most likely be of greatest value.« less

Digital Control of the Czochralski Growth of Gallium Arsenide. System Reference Manual. Valid for Czochralski Growth Controller Software Version 2.4

DTIC Science & Technology

1988-01-04

Controller Routine .......... ........................ 405 -viii- ’ O, ...1 . • N SList of Illustrations i p List of Illustrations . Fig. 1: A...J------ - - - 6 - -- -w -- -w -r n . w ~ - P a CGCS Program Versions ~CGCS Program Versions This section describes the "evolution" of the...8217 ~- 134 - ,d" - 1’ , n "W , ’." " a 4 r P . ’ ,’ r t r 1 "."." , . L t * 5.1 CGCS Concept and Structure 5. The Czochralski Growth Control System Software