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1

Influence of adding borax and modifying pH on effectiveness of food attractants for melon fly (Diptera: Tephritidae).  

PubMed

The melon fly, Bactrocera cucurbitae (Coquillett) (Diptera: Tephritidae), is the most damaging pest of cucurbits in Reunion Island. The influence of adding borax and modifying pH on the effectiveness of different food attractants for both sexes of the melon fly is analyzed by a release-recapture method in field cages. Adding borax to protein hydrolysates Nulure and Buminal strongly reduced their attractiveness for B. cucurbitae. Acidification of 5% Buminal solution (from pH 6 to pH 3) doubled its attractiveness for melon fly. Conversely, Torula yeast at pH 10.5 was significantly more attractive than the standard Torula yeast at pH 9 (28% of captured flies compared with 17%). However, a further pH increase of the yeast solution does not improve its attractiveness. The results are discussed in relation to other studies on pH modification of various baits for Tephritidae. PMID:15279302

Duyck, P F; Rousse, P; Ryckewaert, P; Fabre, F; Quilici, S

2004-06-01

2

Effect of borax on hydration and hardening properties of magnesium and pottassium phosphate cement pastes  

Microsoft Academic Search

Magnesium and potassium phosphate cement (MKPC) sample were prepared by mixing dead burnt MgO powder, potassium phosphate\\u000a and different dosages of retarder borax to investigate the effect of borax on its hydration and hardening characteristics.\\u000a The pH value, fluidity, hydration temperature and strength development of MKPC paste were investigated, and the mineralogical\\u000a composition and microstructural morphology of its hydration products

Jianming Yang; Chunxiang Qian

2010-01-01

3

[Infrared spectral analysis for calcined borax].  

PubMed

To valuate the quality of calcined borax which is sold in the market, 18 samples of calcined borax were studied using the Fourier transform infrared, and samples with different water content were selected and analyzed. Then, the results of analysis were used to evaluate the quality of calcined borax. Results show that the infrared spectra of calcined borax include OH vibration, BO3(-3) vibration and BO4(5-) vibration absorption bands. The position and width of OH vibration absorption band depend on the level of water content, and the more the water content, the wider the absorption band. The number of BO3(3-) vibration and BO4(5-) vibration bands also depend on the level of water content, and the more the water content, and the stronger the hydrogen bond and the lower the symmetry of B atoms, the more the number of infrared absorption peaks. It was concluded that because the quality of calcined borax has direct correlation with water content, the infrared spectroscopy is an express and objective approach to quality analysis and evaluation of calcined borax. PMID:22007396

Zhao, Cui; Ren, Li-Li; Wang, Dong; Zhou, Ping; Zhang, Qian; Wang, Bo-Tao

2011-08-01

4

internal solution containing 140 mM KCl, 2 mM MgCl2, 10 mM EGTA, 10 mM HEPES at pH 7.2. The external solution was Leibovitz's L-15 (Gibco) containing 136 mM NaCl,  

E-print Network

internal solution containing 140 mM KCl, 2 mM MgCl2, 10 mM EGTA, 10 mM HEPES at pH 7.2. The external solution was Leibovitz's L-15 (Gibco) containing 136 mM NaCl, 5.8 mM NaH2PO4, 5.4 mM KCl, 1.3 mM CaCl2, 0.9 mM MgCl2 at pH 7.2. Osmolarity was adjusted to 300 mosM l21 . Motility was measured

Shilo, Benny

5

Ingredients: Borax (found in the laundry section of the store)  

E-print Network

Ingredients: white glue Borax (found in the laundry section of the store) Water Food coloring properties. Polymers are huge molecules, and while most people think of synthetic plastics, natural polymers

6

Beneficiation of borax by reverse flotation in boron saturated brine.  

PubMed

Flotation is one of the plausible methods for recovering borax fines discharged as fine waste to the tailings dam in the Kirka borax processing plant. A literature review dealing with the flotation behavior of boron minerals reveals that clay minerals in the boron ores coat boron minerals and thus deteriorate the quality of boron concentrates produced by direct flotation. The main objective of this study is therefore to recover borax fines from the tailings of the concentrator by reverse flotation. A three-level-factor experimental design was used to determine the main and interaction effects of variables selected on the metallurgical performance of reverse flotation. An analysis of variance for experimental results indicates that interaction effects of the variables for concentrate quality and recovery of B2O3 is nonsignificant and the most important variable for grade of concentrate and recovery is the collector dosage. It is shown that a concentrate assaying 11.25% B2O3 with 89.90% B2O3 recovery could be produced by means of single-stage (rougher) reverse flotation. Additionally, in order to produce a sufficient-quality concentrate, a multistage reverse flotation scheme involving rougher, scavenger, and two cleaners was devised. A final concentrate containing 23.47% B2O3 with 81.78% B2O3 recovery was obtained from these tests. The reverse flotation method can be thus considered as an important option for the beneficiation of borax fines. PMID:15939429

Cafer Cilek, Emin; Uresin, Hasan

2005-10-15

7

Photonic crystal borax competitive binding carbohydrate sensing motif†  

PubMed Central

We developed a photonic crystal sensing method for diol containing species such as carbohydrates based on a poly(vinyl alcohol) (PVA) hydrogel containing an embedded crystalline colloidal array (CCA). The polymerized CCA (PCCA) diffracts visible light. We show that in the presence of borax the diffraction wavelength shifts as the concentration of glucose changes. The diffraction shifts result from the competitive binding of glucose to borate, which reduces the concentration of borate bound to the PVA diols. PMID:19381378

Cui, Qingzhou; Muscatello, Michelle M. Ward; Asher, Sanford A.

2009-01-01

8

Toxicity detection of sodium nitrite, borax and aluminum potassium sulfate using electrochemical method.  

PubMed

Based on the inhibition effect on the respiratory chain activity of microorganisms by toxicants, an electrochemical method has been developed to measure the current variation of a mediator in the presence of microorganisms contacted with a toxicant. Microelectrode arrays were adopted in this study, which can accelerate the mass transfer rate of an analyte to the electrode and also increase the total current signal, resulting in an improvement in detection sensitivity. We selected Escherichia coli as the testee and the standard glucose-glutamic acid as an exogenous material. Under oxygen restriction, the experiments in the presence of toxicant were performed at optimum conditions (solution pH 7.0, 37 degrees C and reaction for 3 hr). The resulting solution was then separated from the suspended microorganisms and was measured by an electrochemical method, using ferricyanide as a mediator. The current signal obtained represents the reoxidation of ferrocyanide, which was transformed to inhibiting efficiency, IC50, as a quantitative measure of toxicity. The IC50 values measured were 410, 570 and 830 mg/L for sodium nitrite, borax and aluminum potassium sulfate, respectively. The results show that the toxicity sequence for these three food additives is consistent with the value reported by other methods. Furthermore, the order of damage degree to the microorganism was also observed to be: sodium nitrite > borax > aluminum potassium sulfate > blank, according to the atomic force microscopy images of E. coli after being incubated for 3 hr with the toxic compound in buffer solutions. The electrochemical method is expected to be a sensitive and simple alternative to toxicity screening for chemical food additives. PMID:23923788

Yu, Dengbin; Yong, Daming; Dong, Shaojun

2013-04-01

9

Dynamics of pH modification of an acidic protein bait used for tropical fruit flies (Diptera: Tephritidae).  

PubMed

Several species of Anastrepha and Bactrocera fruit flies (Diptera: Tephritidae) are captured in traps baited with the protein bait NuLure combined with borax (sodium tetraborate decahydrate) in an aqueous solution, typically 9% NuLure (vol:vol) with 3% borax (wt:vol). NuLure is an acid hydrolysate of corn and has an acidic pH. Addition of borax makes the solution more alkaline, and increase in alkalinity results in increase of ammonia release from the bait solution. This is a very dynamic system, with resultant pH affected by factors such as the amount of borax added, the pH of the water used for preparation, the age of the bait solution, and the development of microbial growth. Problems with borax include amount needed to increase alkalinity of NuLure solutions, which creates difficulties in disposing of spent bait in fruit fly trapping programs. Therefore, research was conducted to evaluate NaOH as an alternative method to increase alkalinity of NuLure solutions. Laboratory experiments compared effect of NaOH versus borax for pH modification on changes in pH and ammonia content of NuLure solutions over time. Although NuLure/NaOH solutions could be adjusted to a more alkaline pH than NuLure/borax solutions, borax plays a critical role in pH stability over time. However, the pH of NuLure/NaOH is stabilized when propylene glycol (10% vol:vol) was used to prepare the bait solution. The use of NaOH can provide an alternative to the use of borax to increase bait solution alkalinity. PMID:20069869

Heath, Robert R; Vazquez, Aime; Schnell, Elena Q; Villareal, Janett; Kendra, Paul E; Epsky, Nancy D

2009-12-01

10

Dispersion of borax in plastic is excellent fire-retardant heat insulator  

NASA Technical Reports Server (NTRS)

A mix of borax powder and a chlorinated anhydrous polyester resin yields a plastic composition that is fire-retardant, yields a minimum of toxic gases when heated, and exhibits high thermal insulating properties. This composition can be used as a coating or can be converted into laminated or cast shapes.

Evans, H.; Hughes, J.; Schmitz, F.

1967-01-01

11

NUCLATION PAR LE BORAX DU SULFATE DE SODIUM DISPERS. APPLICATION POSSIBLE AU STOCKAGE THERMIQUE  

E-print Network

L-359 NUCL�ATION PAR LE BORAX DU SULFATE DE SODIUM DISPERS�. APPLICATION POSSIBLE AU STOCKAGE un intérêt pour la réalisation de stockage thermique. Abstract. 2014 The crystallization of droplets stockage thermique. Mais sous forme macroscopique le rendement du stockage baisse a chaque cycle du fait de

Boyer, Edmond

12

Enhancing fluorescence intensity of Ellagic acid in Borax-HCl-CTAB micelles  

NASA Astrophysics Data System (ADS)

Ellagic acid (C 14H 6O 8), a naturally occurring phytochemical, found mainly in berries and some nuts, has anticarcinogenic and antioxidant properties. It is found that fluorescence of Ellagic acid (EA) is greatly enhanced by micelle of cetyltrimethylammonium bromide (CTAB) surfactant. Based on this effect, a sensitive proposed fluorimetric method was applied for the determination of Ellagic acid in aqueous solution. In the Borax-HCl buffer, the fluorescence intensity of Ellagic acid in the presence of CTAB is proportional to the concentration of Ellagic acid in range from 8.0 × 10 -10 to 4.0 × 10 -5 mol L -1; and the detection limits are 3.2 × 10 -10 mol L -1 and 5.9 × 10 -10 mol L -1 excited at 266 nm and 388 nm, respectively. The actual samples of pomegranate rinds are simply manipulated and satisfactorily determined. The interaction mechanism studies argue that the negative EA-Borax complex is formed and solubilized in the cationic surfactant CTAB micelle in this system. The fluorescence intensity of EA enhances because the CTAB micelle provides a hydrophobic microenvironment for EA-Borax complex, which can prevent collision with water molecules and decrease the energy loss of EA-Borax complex.

Wang, Feng; Huang, Wei; Zhang, Shuai; Liu, Guokui; Li, Kexiang; Tang, Bo

2011-03-01

13

Characterization of uranium surfaces machined with aqueous propylene glycol-borax or perchloroethylene-mineral oil coolants  

SciTech Connect

The use of perchloroethylene (perc) as an ingredient in coolants for machining enriched uranium at the Oak Ridge Y-12 Plant has been discontinued because of environmental concerns. A new coolant was substituted in December 1985, which consists of an aqueous solution of propylene glycol with borax (sodium tetraborate) added as a nuclear poison and with a nitrite added as a corrosion inhibitor. Uranium surfaces machined using the two coolants were compared with respects to residual contamination, corrosion or corrosion potential, and with the aqueous propylene glycol-borax coolant was found to be better than that of enriched uranium machined with the perc-mineral oil coolant. The boron residues on the final-finished parts machined with the borax-containing coolant were not sufficient to cause problems in further processing. All evidence indicated that the enriched uranium surfaces machined with the borax-containing coolant will be as satisfactory as those machined with the perc coolant.

Cristy, S.S.; Bennett, R.K. Jr.; Dillon, J.J.; Richards, H.L.; Seals, R.D.; Byrd, V.R.

1986-12-31

14

Epoxy-borax-coal tar composition for a radiation protective, burn resistant drum liner and centrifugal casting method  

DOEpatents

A boron containing burn resistant, low level radiation protection material useful, for example, as a liner for radioactive waste disposal and storage, a component for neutron absorber, and a shield for a neutron source. The material is basically composed of Borax in the range of 25-50%, coal tar in the range of 25-37.5%, with the remainder being an epoxy resin mix. A preferred composition is 50% Borax, 25% coal tar and 25% epoxy resin. The material is not susceptible to burning and is about 1/5 the cost of existing radiation protection material utilized in similar applications.

Taylor, Robert S. (Livermore, CA); Boyer, Norman W. (Livermore, CA)

1980-01-01

15

Photonic crystal borax competitive binding carbohydrate sensing motif Qingzhou Cui, Michelle M. Ward Muscatello and Sanford A. Asher*  

E-print Network

Photonic crystal borax competitive binding carbohydrate sensing motif Qingzhou Cui, Michelle M crystal sensing method for diol containing species such as carbohydrates based on a poly(vinyl alcohol- hydrates.8 Determination of carbohydrates is important in applications such as controlling glycemia

Asher, Sanford A.

16

Experimenting with cameraless photography using turmeric and borax: an introduction to photophysics  

NASA Astrophysics Data System (ADS)

An alcoholic extract of the spice turmeric can be used to create a light-sensitive dye that can be used to stain paper. On exposure to sunlight, the dyed paper can be used to capture photographic images of flat objects or reproduce existing images through the preferential degradation of the dye in light-exposed areas over a time period of a few hours. The images can be developed and preserved by spraying the exposed paper with a dilute solution of borax, which forms coloured organo-boron complexes that limit further degradation of the dye and enhance the colour of the image. Similar photochemical reactions that lead to the degradation of the turmeric dye can also be used for reducing the organic pollution load in wastewater produced by many industrial processes and in dye-sensitized solar cells for producing electricity.

Appleyard, S. J.

2012-07-01

17

Borax in the supraglacial moraine of the Lewis Cliff, Buckley Island quadrangle--first Antarctic occurrence  

USGS Publications Warehouse

During the 1987-1988 austral summer field season, membersof the south party of the antarctic search for meteorites south-ern team* working in the Lewis Cliff/Colbert Hills region dis-covered several areas of unusual mineralization within theLewis Cliff ice tongue and its associated moraine field (figure1). The Lewis Cliff ice tongue (84°15'S 161°25'E) is a meteorite-stranding surface of ablating blue ice, about 2.3 by 7.0 kilo-meters, bounded on the west by the Lewis Cliff, on the northand northeast by a large supraglacial moraine, and on the eastby the Colbert Hills. To the south it opens to the Walcott Névé.Because it is a meteorite-stranding surface, the major component of ice motion in the area is believed to be vertical(Whillans and Cassidy 1983). The presence of Thule-Baffinmoraines at the northern terminus of the blue ice tends tosupport the hypothesis that the area underlying the moraineis essentially stagnant and that ice arriving from the south ispiling up against it. Areas containing mineral deposits werefound within the moraine field to the north and east of theblue ice margin and also along the east margins of the blue iceitself. Subsequent X-ray diffraction analyses of these depositshave shown that they are composed predominantly of nah-colite (NaHCO3), trona [Na3(CO3)(HCO3) · 2H20], borax[Na2B405(OH)4 · 8H20], and a new hexagonal hydrous sulfatespecies. This paper reports the details of the borax occurrence,because it is the first known on the continent.

Fitzpatrick, J.J.; Muhs, D.R.

1989-01-01

18

8mm/16mm Movie-Making.  

ERIC Educational Resources Information Center

The materials, techniques, and attitudes needed to make professional-quality movies using 8mm., super 8mm., and 16mm. amateur equipment are covered in this guide to movie-making. The pros and cons are discussed of the various makes and models of cameras and lenses. Other topics discussed are: exposure and lighting, choosing film, camera speed and…

Provisor, Henry

19

Mg- and K-bearing borates and associated evaporites at Eagle Borax spring, Death Valley, California: A spectroscopic exploration  

USGS Publications Warehouse

Efflorescent crusts at the Eagle Borax spring in Death Valley, California, contain an array of rare Mg and K borate minerals, several of which are only known from one or two other localities. The Mg- and/or K-bearing borates include aristarainite, hydroboracite, kaliborite, mcallisterite, pinnoite, rivadavite, and santite. Ulexite and probertite also occur in the area, although their distribution is different from that of the Mg and K borates. Other evaporite minerals in the spring vicinity include halite, thenardite, eugsterite, gypsum-anhydrite, hexahydrite, and bloedite. Whereas the first five of these minerals are found throughout Death Valley, the last two Mg sulfates are more restricted in occurrence and are indicative of Mg-enriched ground water. Mineral associations observed at the Eagle Borax spring, and at many other borate deposits worldwide, can be explained by the chemical fractionation of borate-precipitating waters during the course of evaporative concentration. The Mg sulfate and Mg borate minerals in the Eagle Borax efflorescent crusts point to the fractionation of Ca by the operation of a chemical divide involving Ca carbonate and Na-Ca borate precipitation in the subsurface sediments. At many other borate mining localities, the occurrence of ulexite in both Na borate (borax-kernite) and Ca borate (ulexite-colemanite) deposits similarly reflects ulexite's coprecipitation with Ca carbonate at an early concentration stage. Such ulexite may perhaps be converted to colemanite by later reaction with the coexisting Ca carbonate - the latter providing the additional Ca2+ ions needed for the conversion. Mg and Ca-Mg borates are the expected late-stage concentration products of waters forming ulexite-colemanite deposits and are therefore most likely to occur in the marginal zones or nearby mud facies of ulexite-colemanite orebodies. Under some circumstances, Mg and Ca-Mg borates might provide a useful prospecting guide for ulexite-colemanite deposits, although the high solubility of Mg borate minerals may prevent their formation in lacustrine settings and certainly inhibits their geologic preservation. The occurrence of Mg borates in borax-kernite deposits is also related to fractionation processes and points to the operation of an Mg borate chemical divide, characterized by Mg borate precipitation ahead of Mg carbonate. All of these considerations imply that Mg is a significant chemical component of many borate-depositing ground waters, even though Mg borate minerals may not be strongly evident in borate orebodies. The Eagle Borax spring borates and other evaporite minerals were studied using spectroscopic and X-ray powder diffraction methods, which were found to be highly complementary. Spectral reflectance measurements provide a sensitive means for detecting borates present in mixtures with other evaporites and can be used to screen samples rapidly for X-ray diffraction analysis. The apparently limited occurrence of Mg and K borate minerals compared to Ca and Na borates may stem partly from the inefficiency of X-ray diffraction methods for delineating the mineralogy of large and complex deposits. Spectral reflectance measurements can be made in the laboratory, in the field, on the mine face, and even remotely. Reflectance data should have an important role in studies of existing deposit mineralogy and related chemical fractionation processes, and perhaps in the discovery of new borate mineral resources.

Crowley, J.K.

1996-01-01

20

Preparing high- and low-aspect ratio AlB 2 flakes from borax or boron oxide  

Microsoft Academic Search

The commercial preparation of aluminum-diboride flakes in aluminum relies on relatively expensive starting materials. A new\\u000a synthesis has been developed that allows AlB2 to be prepared directly from the reaction of borax (Na2B4O710H2O) or boron oxide (B2O3) with aluminum. Aluminum metal at temperatures higher than 900C has been shown to reduce these boron-containing compounds,\\u000a producing an Al2O3-containing slag and AlB2.

A. C. Hall; J. Economy

2000-01-01

21

Precipitation method for barium metaborate (BaB{sub 2}O{sub 4}) synthesis from borax solution  

SciTech Connect

In this study, barium metaborate (BaB{sub 2}O{sub 4}, BMB) synthesis from the borax solution was carried out. BMB currently is used in production of ceramic glazes, luminophors, oxide cathodes as well as additives to pigments for aqueous emulsion paints and also ??BaB{sub 2}O{sub 4} single crystals are the best candidate for fabrication of solid-state UV lasers operating at a wavelength of 200 nm due to excellent nonlinear optical properties. In the present study, synthesis was carried out from the borax solution (Na{sub 2}B{sub 4}O{sub 7?}10H{sub 2}O, BDH) and barium chloride (BaCI{sub 2?}2H{sub 2}O, Ba) in the glass-batch reactor with stirring. The effect of, times (5-15 min), molar ratio [stoich.ration (1.0:2.0), 1.25:2.0, 1.5:2.0, 2.5:2:0, 3.0:2.0, 3.5:2.0,4.0:2.0, 5.0:2.0] and also crystallization time (2-6 hour) on the BMB yield (%) was investigated at 80 °C reaction temperature. It is found that, BMB precipitation synthesis with 90 % yield can be performed from 0.50 molar ration (BDH:Ba), under 80 °C, 15 minute, and 6 hours crystallization time. The structural properties of BMB powders were characterized by using XRD, FT-IR and DTA-TG instrumental analysis technique.

Ak?ener, Eymen; Figen, Aysel Kantürk; Pi?kin, Sabriye [Yildiz Technical University, Chem. Eng. Dept., Davutpasa Campus, 34210, Istanbul (Turkey)

2013-12-16

22

Density, thermal expansion coefficient and viscosity of sodium tetraborate (borax)-UO 2 and of sodium metaborate-UO 2 solutions at high temperatures  

NASA Astrophysics Data System (ADS)

Measurements have been performed of the density, of the volumetric thermal expansion coefficient and of the viscosity of liquid sodium tetraborate (borax) and of sodium metaborate both pure and with two different amounts of UO 2 dissolved in each. The viscosity measurements have been performed for the solution of sodium tetraborate with UO 2 and CeO 2, and with CeO 2 only as well. These data are required for the design of core-catchers based on sodium borates. The density measurements have been performed with the buoyancy method in the temperature range from 825°C to 1300°C, the viscosity measurements in the temperature range 700-1250°C with a modified Haake viscosity balance. The balance was previously calibrated at ambient temperature with a standard calibration liquid and at high temperatures with data for pure borax available from the literature.

Donne, M. Dalle; Dorner, S.; Roth, A.

1983-10-01

23

DETERMINATION OF REFRACTORY METALS IN FERROUS ALLOYS AND HIGH-ALLOY STEEL BY THE BORAX DISK X-RAY SPECTROCHEMICAL METHOD  

Microsoft Academic Search

X-ray spectrochemical methods were developed for the determination of ; Mo, W, Nb, and Ta in heat-resisting and corrosion-resisting alloys and of Mo and ; W in high-alloy steel. The refractory metals are separated from the bulk of the ; alloy matrix by convertional chemical separations, converted to oxides, fused in ; borax, and then determined by x-ray spectrochemical analysis.

C. L. Luke

1963-01-01

24

Primeval galaxies in the sub-mm and mm  

NASA Technical Reports Server (NTRS)

Although the results of COBE's FIRAS experiment 1 constrain the deviation in energy from the CMB blackbody in the 500-5000 micron range to be delta E/E, sub cmb less than 0.005, primeval galaxies can still lead to a brilliant sub-mm sky of non-Gaussian sources that are detectable at 10 inch resolution from planned arrays such as SCUBA on the James Clerk Maxwell Telescope and, quite plausibly, at sub-arcsecond resolution in planned mm and sub-mm interferometers. Here, we apply our hierarchical peaks method to a CDM model to construct sub-mm and mm maps of bursting PG's appropriate for these instruments with minimum contours chosen to correspond to realistic observational parameters for them and which pass the FIRAS limits.

Bond, J. Richard; Myers, Steven T.

1993-01-01

25

Racing M&M Colors  

NSDL National Science Digital Library

Learners design their own experiment to determine which M&M color dissolves the fastest in water. Learners should have a plan to control variables such as type of plate, amount of water, temperature of water, how and where the M&M's are placed on the plate, etc. Learners perform their experiment, collect data and discuss their results.

Kessler, James H.; Galvan, Patricia M.

2007-01-01

26

SSC 40 mm cable results and 50 mm design discussions  

SciTech Connect

A summary of the cable produced for the 1990 40 mm Dipole Program is presented. The cable design parameters for the 50 mm Dipole Program are discussed, as well as portions of the SSC specification draft. Considerations leading to the final cable configuration and the results of preliminary trials are included. The first iteration of a strand mapping program to automate cable strand maps is introduced. 7 refs., 2 figs., 1 tab.

Christopherson, D.; Capone, D.; Hannaford, R.; Remsbottom, R.; Jayakumar, R.; Snitchler, G. (Superconducting Super Collider Lab., Dallas, TX (United States)); Scanlan, R.; Royet, J. (Lawrence Berkeley Lab., CA (United States))

1990-09-01

27

The GBT 4mm Receiver  

NASA Astrophysics Data System (ADS)

The new 4mm receiver (67--93 GHz) for the Robert C. Byrd Green Bank Telescope (GBT) was built to take advantage of the improved surface accuracy of the dish. The low frequency end of the 3mm atmospheric window is not available with ALMA (<84 GHz), and the sensitivity of the GBT is better than any other facility within this band. We discuss the design and performance of this new receiver for the GBT, and highlight the science opportunities available with the instrument. The National Radio Astronomy Observatory is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc.

Frayer, David T.; White, S.; Watts, G.; Stennes, M.; Maddalena, R. J.; Simon, R.; Pospieszalski, M.; Bryerton, E.

2013-01-01

28

Effect of the borax mass and pre-spray medium temperature on droplet size and velocity vector distributions of intermittently sprayed starchy solutions.  

PubMed

Spray coating technology has demonstrated great potential in the slow release fertilizers industry. The better understanding of the key spray parameters benefits both the environment and low cost coating processes. The use of starch based materials to coat the slow release fertilizers is a new development. However, the hydraulic spray jet breakup of the non-Newtonian starchy solutions is a complex phenomenon and very little known. The aim of this research was to study the axial and radial distributions of the Sauter Mean Diameter (SMD) and velocity vectors in pulsing spray patterns of native and modified tapioca starch solutions. To meet the objective, high speed imaging and Phase Doppler Anemometry (PDA) techniques were employed to characterize the four compositions of the starch-urea-borax complex namely S0, S1, S2 and S3. The unheated solutions exhibited very high viscosities ranging from 2035 to 3030 cP. No jet breakup was seen at any stage of the nozzle operation at an injection pressure of 1-5 bar. However, at 80 °C temperature and 5 bar pressure, the viscosity was reduced to 455 to 638 cP and dense spray patterns emerged from the nozzle obscuring the PDA signals. The axial size distribution revealed a significant decrease in SMD along the spray centreline. The smallest axial SMD (51 to 79 ?m) was noticed in S0 spray followed by S1, S2 and S3. Unlikely, the radial SMD in S0 spray did not vary significantly at any stage of the spray injection. This trend was attributed to the continuous growth of the surface wave instabilities on the native starch sheet. However, SMD obtained with S1, S2 and S3 varied appreciably along the radial direction. The mean velocity vector profiles followed the non-Gaussian distribution. The constant vector distributions were seen in the near nozzle regions, where the spray was in the phase of development. In far regions, the velocity vectors were poly-dispersed and a series of ups and downs were seen in the respective radial distributions. PMID:25557285

Naz, Muhammad Yasin; Sulaiman, Shaharin Anwar; Ariwahjoedi, Bambang

2015-02-01

29

An Approximate Solution for Ph/Ph/1 and Ph/Ph/1/N Queues  

E-print Network

An Approximate Solution for Ph/Ph/1 and Ph/Ph/1/N Queues Alexandre Brandwajn Baskin School approximation to assess the steady-state probabilities of the number of customers in Ph/Ph/1 and Ph/Ph/1/N for the Ph/Ph/1/N queue. The phase-type distributions considered are assumed to be acyclic. Our method

Begin, Thomas

30

In vivo models of multiple myeloma (MM).  

PubMed

The development of the plasma cell tumor (PCT) model was the first widely accepted in vivo model of multiple myeloma (MM). Potter and colleagues used this chemically induced PCT model to study the pathophysiology of malignant plasma cells and also used it to screen anti-MM agents. Two decades later the C57BL/KaLwRij mouse strain was found to spontaneously develop MM. Testing of pamidronate using this endogenously arising MM model revealed significant reductions in MM-associated bone disease, which was subsequently confirmed in human trials in MM patients. Transgenic models have also been developed in which the MM is localized in the bone marrow causing lytic bone lesions. Experiments in a transgenic model showed that a new oral proteasome inhibitor was effective at reducing MM burden. A clinical trial later confirmed this observation and validated the model. The xenograft model has been used to grow human MM in immunocompromised mice. The xenograft models of MM have been very useful in optimizing drug schedules and doses, which have helped in the treatments given to MM patients. However, in vivo models have been criticized for having a low clinical predictive power of new chemical entities (NCEs). Despite this, the knowledge gained from in vivo models of MM has without a doubt benefited MM patients. PMID:24704250

Sanchez, Eric; Chen, Haiming; Berenson, James R

2014-06-01

31

Hickey -TT175, casts 220, line 222-229,231-232 Cruise cast lat(dd.mm.mm) lon(dd.mm.mm) Date/Time (MMDDYYHHMM) Total Scans  

E-print Network

Hickey -TT175, casts 220, line 222- 229,231-232 Cruise cast lat(dd.mm.mm) lon(dd.mm.mm) Date,220 #12;Hickey -TT175, casts 220, line 222- 229,231-232 Cruise cast lat(dd.mm.mm) lon(dd.mm.mm) Date #12;Hickey -TT175, casts 220, line 222- 229,231-232 Cruise cast lat(dd.mm.mm) lon(dd.mm.mm) Date

Hickey, Barbara

32

Hickey -TT174, casts 21, line 18 to cast 31, line 24 Cruise cast lat(dd.mm.mm) lon(dd.mm.mm) Date/Time (MMDDYYHHMM) Total Scans  

E-print Network

Hickey -TT174, casts 21, line 18 to cast 31, line 24 Cruise cast lat(dd.mm.mm) lon(dd.mm.mm) Date;Hickey -TT174, casts 21, line 18 to cast 31, line 24 Cruise cast lat(dd.mm.mm) lon(dd.mm.mm) Date;Hickey -TT174, casts 21, line 18 to cast 31, line 24 Cruise cast lat(dd.mm.mm) lon(dd.mm.mm) Date

Hickey, Barbara

33

Application of MM wave therapy in radiology  

SciTech Connect

The authors studied the effects of MM wave electromagnetic radiation influence on patients, affected by X-ray radiation during the reparation works after Chernobyl nuclear power plant exposure. They compared results of treatment of two groups of patients: (1) control group patients received only basis therapy; (2) testing group, 10 patients received basis therapy and MM wave influence. The authors used the wide band noise generator `Artsakh - 2` for local irradiation on the acupuncture points. Their data proved that low intensity MM waves have immunocorrective, antioxidant effects, and MM wave therapy is a perspective method for treatment of patients with radiological pathology.

Avakian, R.S. [Inst. of Radio Physics & Electronics, Ashtarack (Argentina); Gasparyan, L.V. [Republican Medical Centre Armenia, Yerevan (Argentina)

1995-12-31

34

Crew-Served Machine Guns 5.56-mm and 7.62-mm  

E-print Network

FM 3-22.68 Crew-Served Machine Guns 5.56-mm and 7.62-mm JULY 2006 DISTRIBUTION RESTRICTION-Served Machine Guns 5.56-mm and 7.62-mm Contents Page Weapons Index............................................................................................................................................... xvii Chapter 1 M249 MACHINE GUN

US Army Corps of Engineers

35

New NRD guide MM wave oscillators  

Microsoft Academic Search

A new millimenter-wave Gunn oscillator is described. The present structure makes use of NRD guide and metal resonant cap. The field expressions and the design considerations of NRD guide are discussed. Some experimental results of 8mm and 6mm band oscillators show that the new Gunn oscillator has a future as an integrated millimeter-wave source.

Jing-Feng Miao

1992-01-01

36

MM Algorithms for Some Discrete Multivariate Distributions  

PubMed Central

The MM (minorization–maximization) principle is a versatile tool for constructing optimization algorithms. Every EM algorithm is an MM algorithm but not vice versa. This article derives MM algorithms for maximum likelihood estimation with discrete multivariate distributions such as the Dirichlet-multinomial and Connor–Mosimann distributions, the Neerchal–Morel distribution, the negative-multinomial distribution, certain distributions on partitions, and zero-truncated and zero-inflated distributions. These MM algorithms increase the likelihood at each iteration and reliably converge to the maximum from well-chosen initial values. Because they involve no matrix inversion, the algorithms are especially pertinent to high-dimensional problems. To illustrate the performance of the MM algorithms, we compare them to Newton’s method on data used to classify handwritten digits. PMID:20877446

Zhou, Hua; Lange, Kenneth

2010-01-01

37

pH Protocol  

NSDL National Science Digital Library

The purpose of this resource is to measure the pH of water. Students use either a pH meter or pH paper to measure the pH. If using the pH meter, the meter needs to be calibrated with buffer solutions that have pH values of 4, 7, and 10.

The GLOBE Program, UCAR (University Corporation for Atmospheric Research)

2005-06-02

38

MM Algorithms for Geometric and Signomial Programming.  

PubMed

This paper derives new algorithms for signomial programming, a generalization of geometric programming. The algorithms are based on a generic principle for optimization called the MM algorithm. In this setting, one can apply the geometric-arithmetic mean inequality and a supporting hyperplane inequality to create a surrogate function with parameters separated. Thus, unconstrained signomial programming reduces to a sequence of one-dimensional minimization problems. Simple examples demonstrate that the MM algorithm derived can converge to a boundary point or to one point of a continuum of minimum points. Conditions under which the minimum point is unique or occurs in the interior of parameter space are proved for geometric programming. Convergence to an interior point occurs at a linear rate. Finally, the MM framework easily accommodates equality and inequality constraints of signomial type. For the most important special case, constrained quadratic programming, the MM algorithm involves very simple updates. PMID:24634545

Lange, Kenneth; Zhou, Hua

2014-02-01

39

Mm-Wave Silicon SensorsMm-Wave Silicon Sensors and Active Tagsand Active Tags  

E-print Network

Voinigescu, November 21, 2014 3 Why mm-wave sensors?Why mm-wave sensors? Work in hostile and poor visibility New ApplicationsNew Applications Autonomous robots Autonomous drone swarms Toy helicopters www

Prodiæ, Aleksandar

40

40 CFR Table 1 to Subpart Mm of... - General Provisions Applicability to Subpart MM  

Code of Federal Regulations, 2013 CFR

...Stand-Alone Semichemical Pulp Mills Pt. 63, Subpt. MM, Table 1 Table 1 to Subpart MM of Part 63—General Provisions Applicability...4) Progress reports Yes 63.10(d)(5) Periodic and immediate startup, shutdown, and malfunction...

2013-07-01

41

40 CFR Table 1 to Subpart Mm of... - General Provisions Applicability to Subpart MM  

Code of Federal Regulations, 2011 CFR

...Stand-Alone Semichemical Pulp Mills Pt. 63, Subpt. MM, Table 1 Table 1 to Subpart MM of Part 63—General Provisions Applicability...4) Progress reports Yes 63.10(d)(5) Periodic and immediate startup, shutdown, and malfunction...

2011-07-01

42

40 CFR Table 1 to Subpart Mm of... - General Provisions Applicability to Subpart MM  

Code of Federal Regulations, 2012 CFR

...Stand-Alone Semichemical Pulp Mills Pt. 63, Subpt. MM, Table 1 Table 1 to Subpart MM of Part 63—General Provisions Applicability...4) Progress reports Yes 63.10(d)(5) Periodic and immediate startup, shutdown, and malfunction...

2012-07-01

43

40 CFR Table 1 to Subpart Mm of... - General Provisions Applicability to Subpart MM  

Code of Federal Regulations, 2010 CFR

...Stand-Alone Semichemical Pulp Mills Pt. 63, Subpt. MM, Table 1 Table 1 to Subpart MM of Part 63—General Provisions Applicability...4) Progress reports Yes 63.10(d)(5) Periodic and immediate startup, shutdown, and malfunction...

2010-07-01

44

40 CFR Table 1 to Subpart Mm of... - General Provisions Applicability to Subpart MM  

...Stand-Alone Semichemical Pulp Mills Pt. 63, Subpt. MM, Table 1 Table 1 to Subpart MM of Part 63—General Provisions Applicability...4) Progress reports Yes 63.10(d)(5) Periodic and immediate startup, shutdown, and malfunction...

2014-07-01

45

Fast molecular jet from L1157-mm  

NASA Astrophysics Data System (ADS)

Context. L1157-mm powers a molecular outflow that is well-known for its shock-induced chemical activity in several hot-spots. Aims: We have studied the molecular emission toward L1157-mm searching for a jet component responsible for these spots. Methods: We used the IRAM 30 m telescope to observe the vicinity of L1157-mm in several lines of SiO. Results: The SiO(5-4) and SiO(6-5) spectra toward L1157-mm present blue and red detached components about 45 km s-1 away from the ambient cloud. These extremely high-velocity (EHV) components are similar to those found in the L1448 and IRAS 04166+2706 outflows and probably arise from a molecular jet driven by L1157-mm. Observations of off-center positions indicate that the jet is unresolved in SiO(5-4) (< 11''). Conclusions: The EHV jet seen in SiO probably excites L1157-B1 and the other chemically active spots of the L1157 outflow. Based on IRAM 30 m Telescope observations. IRAM is supported by INSU/CNRS (France), MPG (Germany), and IGN (Spain).Tables 1 and 2 are available in electronic form at http://www.aanda.org

Tafalla, M.; Bachiller, R.; Lefloch, B.; Rodríguez-Fernández, N.; Codella, C.; López-Sepulcre, A.; Podio, L.

2015-01-01

46

Laparoscopic cholecystectomy using 2-mm instruments.  

PubMed

Today, laparoscopic cholecystectomy is the method of choice for treatment of symptomatic gallbladder disorders. It minimizes effects of the operation that are independent of the gallbladder, such as trauma to the abdominal wall and other soft tissue. The surgical wounds were even smaller when 2-mm trocars were used. Laparoscopic cholecystectomy using 2-mm instruments was performed in a consecutive series of 14 patients with symptomatic gallstones. The procedure was completed in 12 cases, with conversion to open surgery in two cases. Intraoperative cholangiography was always performed. The postoperative course was always uneventful. The cosmetic effect was highly satisfactory. The procedure using 2-mm instruments could be indicated in selected patients with uncomplicated gallstone disease. PMID:9820716

Uranüs, S; Peng, Z; Kronberger, L; Pfeifer, J; Salehi, B

1998-10-01

47

Microeconomics of 300-mm process module control  

NASA Astrophysics Data System (ADS)

Simple microeconomic models that directly link metrology, yield, and profitability are rare or non-existent. In this work, we validate and apply such a model. Using a small number of input parameters, we explain current yield management practices in 200 mm factories. The model is then used to extrapolate requirements for 300 mm factories, including the impact of simultaneous technology transitions to 130nm lithography and integrated metrology. To support our conclusions, we use examples relevant to factory-wide photo module control.

Monahan, Kevin M.; Chatterjee, Arun K.; Falessi, Georges; Levy, Ady; Stoller, Meryl D.

2001-08-01

48

Concept : Cell Yield Glucose, mM  

E-print Network

Concept : Cell Yield Glucose, mM 0 50 100 150 200 250 300 0 10 20 30 40 Slope = 7.2 µg/ml per mM dS dX Y s/x = Cell Yield is: ConsumedSubstrate MassCellinChange Y s/x = #12;Cell Growth in Batch.3 Hybridoma 0.05 13.9 Insect Cells 0.06 11.6 Organism #12;Nature of Specific Growth SK S s m + µ =µ S, g/ L µ

Málaga, Universidad de

49

A New Laboratory for MM-/Sub-MM-Wave Characterization of Cosmic Dust Analogs  

NASA Astrophysics Data System (ADS)

Most studies conducted with observatories such as ALMA, SOFIA, PLANCK, and Herschel will benefit from knowledge of (1) the predominant cosmic dust species in various environments, in terms of composition and structure and (2) mm/sub-mm optical properties of cosmic dusts, including the temperature dependent-emissivity and spectral index. A new laboratory has been established for producing and characterizing (in the mm/sub-mm) various silicate/carbonaceous dust candidates. In particular, the optical measurement setup was custom designed, specifically for laboratory studies of dusts, using techniques borrowed from observational cosmology. It features novel designs for a compact Fourier Transform Spectrometer (FTS) and a cold sample holder/exchanger. Construction of this apparatus is now complete; we are currently testing the system. Here, we present the mm/sub-mm measurement scheme and highlight its innovative and aspects.

Birsa, Samuel; Do, Huy; Williams, Frederick; Liu, Lunjun; Schonert, Ryan; Perera, Thushara

2015-01-01

50

M&M's in Different Sugar Solutions  

NSDL National Science Digital Library

In this activity, learners investigate whether having sugar already dissolved in water affects the speed of dissolving and the movement of sugar and color through the water. Learners design their own experiment and identify and control variables. This activity is a follow-up to the activity "Racing M&M Colors" (see related resources).

Kessler, James H.; Galvan, Patricia M.

2007-01-01

51

MM-122: High speed civil transport  

NASA Technical Reports Server (NTRS)

The rapidly expanding Pacific Rim market along with other growing markets indicates that the future market potential for a high speed civil transport is great indeed. The MM-122 is the answer to the international market desire for a state of the art, long range, high speed civil transport. It will carry 250 passengers a distance of 5200 nm at over twice the speed of sound. The MM-122 is designed to incorporate the latest technologies in the areas of control systems, propulsions, aerodynamics, and materials. The MM-122 will accomplish these goals using the following design parameters. First, a double delta wing planform with highly swept canards and an appropriately area ruled fuselage will be incorporated to accomplish desired aerodynamic characteristics. Propulsion will be provided by four low bypass variable cycle turbofan engines. A quad-redundant fly-by-wire flight control system will be incorporated to provide appropriate static stability and level 1 handling qualities. Finally, the latest in conventional metallic and modern composite materials will be used to provide desired weight and performance characteristics. The MM-122 incorporates the latest in technology and cost minimization techniques to provide a viable solution to this future market potential.

Demarest, Bill; Anders, Kurt; Manchec, John; Yang, Eric; Overgaard, Dan; Kalkwarf, Mike

1992-01-01

52

M&M's in Different Temperatures  

NSDL National Science Digital Library

Learners design their own experiment to investigate whether the temperature of the surrounding water affects the rate at which the colored coating dissolves from an M&M. When they conduct their experiment, they find that the color dissolves faster in hot water than in cold.

Kessler, James H.; Galvan, Patricia M.

2007-01-01

53

pH  

NSDL National Science Digital Library

This lab activity is designed to teach students how to test for pH and understand its relationship to them and their environment. They will learn what pH is, draw and label a pH scale, measure the pH of various items, and explain why it's important to understand pH, for example, the danger presented by substances having very high or low pH.

54

Comparison between 28 mm and 32 mm ceramic-on-ceramic bearings in total hip replacement.  

PubMed

Large femoral heads have become popular in total hip replacement (THR) as a method of reducing the risk of dislocation. However, if large heads are used in ceramic-on-ceramic THR, the liner must be thinner, which may increase the risk of fracture. To compare the rates of ceramic fracture and dislocation between 28 mm and 32 mm ceramic heads, 120 hips in 109 patients (51 men and 58 women, mean age 49.2 years) were randomised to THR with either a 28 mm or a 32 mm ceramic articulation. A total of 57/60 hips assigned to the 28 mm group and 55/60 hips assigned to the 32 mm group were followed for at least five years. No ceramic component fractures occured in any patient in either group. There was one dislocation in the 32 mm group and none in the 28 mm group (p = 0.464). No hip had detectable wear, focal osteolysis or prosthetic loosening. In our small study the 32 mm ceramic articulation appeared to be safe in terms of ceramic liner fracture. PMID:25371457

Lee, Y K; Ha, Y C; Koo, K H

2014-11-01

55

Investigation of MM-PBSA rescoring of docking poses.  

PubMed

Target-based virtual screening is increasingly used to generate leads for targets for which high quality three-dimensional (3D) structures are available. To allow large molecular databases to be screened rapidly, a tiered scoring scheme is often employed whereby a simple scoring function is used as a fast filter of the entire database and a more rigorous and time-consuming scoring function is used to rescore the top hits to produce the final list of ranked compounds. Molecular mechanics Poisson-Boltzmann surface area (MM-PBSA) approaches are currently thought to be quite effective at incorporating implicit solvation into the estimation of ligand binding free energies. In this paper, the ability of a high-throughput MM-PBSA rescoring function to discriminate between correct and incorrect docking poses is investigated in detail. Various initial scoring functions are used to generate docked poses for a subset of the CCDC/Astex test set and to dock one set of actives/inactives from the DUD data set. The effectiveness of each of these initial scoring functions is discussed. Overall, the ability of the MM-PBSA rescoring function to (i) regenerate the set of X-ray complexes when docking the bound conformation of the ligand, (ii) regenerate the X-ray complexes when docking conformationally expanded databases for each ligand which include "conformation decoys" of the ligand, and (iii) enrich known actives in a virtual screen for the mineralocorticoid receptor in the presence of "ligand decoys" is assessed. While a pharmacophore-based molecular docking approach, PhDock, is used to carry out the docking, the results are expected to be general to use with any docking method. PMID:18465849

Thompson, David C; Humblet, Christine; Joseph-McCarthy, Diane

2008-05-01

56

Population Simulation with M&M's  

NSDL National Science Digital Library

This activity involves two simulations with M&M's® to explore population growth and decay. The follow-up activity, Population Simulations with Calculators introduces NOW-NEXT or recursive equations as an accessible way to model this behavior and expand to other population models. Using mathematics and mathematical models, students will learn to build and refine models to help predict how the size of a population will change over time.

PBS TeacherSource - Math

2010-01-01

57

mm-wave solid state amplifiers  

Microsoft Academic Search

The development of mm-wave amplifiers using InP Gunn diodes is reviewed including a low-noise eight-stage amplifier for replacement of a Ka-band TWTA and a three-stage amplifier for the 42.5 to 44.5 range with an output power of 100 mW and 20 dB associated gain. A detailed description of a three-stage amplifier for the 54 to 58 GHz range is given

P. H. Wolfert; J. D. Crowley; F. B. Fank

1983-01-01

58

The light curve analysis of MM Herculis  

NASA Astrophysics Data System (ADS)

The photoelectric light curves of MM Her obtained in 1983 and 1984 by Evren (1985, 1987) were analyzed by two different methods. Firstly, the effects of the wave-like distortions on the observations were removed from the observed magnitudes by obtaining its mathematical expression. The remaining light curves were analyzed by using Wood's approach. Later, the light curves of the same years were treated by the method of Wilson-Devinney and distortions seen in the light curves were thought to be explained by locating the spots on the surface of the cooler component. The results obtained by two different approaches are in good agreement.

Evren, S.

1987-10-01

59

Simulation of Thermal Processes in Metamaterial MM-to-IR Converter for MM-wave Imager  

NASA Astrophysics Data System (ADS)

The main characteristics of MM-wave image detector were simulated by means of accurate numerical modelling of thermophysical processes in a metamaterial MM-to-IR converter. The converter represents a multilayer structure consisting of an ultra thin resonant metamaterial absorber and a perfect emissive layer. The absorber consists of a dielectric self-supporting film that is metallized from both sides. A micro-pattern is fabricated from one side. Resonant absorption of the MM waves induces the converter heating that yields enhancement of IR emission from the emissive layer. IR emission is detected by IR camera. In this contribution an accurate numerical model for simulation of the thermal processes in the converter structure was created by using COMSOL Multiphysics software. The simulation results are in a good agreement with experimental results that validates the model. The simulation shows that the real time operation is provided for the converter thickness less than 3 micrometers and time response can be improved by decreasing of the converter thickness. The energy conversion efficiency of MM waves into IR radiation is over 80%. The converter temperature increase is a linear function of a MM-wave radiation power within three orders of the dynamic range. The blooming effect and ways of its reducing are also discussed. The model allows us to choose the ways of converter structure optimization and improvement of image detector parameters.

Zagubisalo, Peter S.; Paulish, Andrey G.; Kuznetsov, Sergey A.

2014-03-01

60

Cold-electron bolometers for future mm and sub-mm sky surveys  

E-print Network

Future sky surveys in the mm/sub-mm range, like the forthcoming balloon-borne missions LSPE, OLIMPO, SPIDER etc., will need detectors insensitive to cosmic rays (CRs) and with a NEP of the order of $10^{-17} \\div 10^{-18}\\,$W/sqrt(Hz). The Cold-Electron Bolometers (CEBs) technology is promising, having the required properties, since the absorber volume is extremely small and the electron system of the absorber is thermally insulated from the phonon system. We have developed an experimental setup to test the optical performance and the CRs insensitivity of CEBs, with the target of integrating them in the OLIMPO and LSPE focal planes.

Salatino, Maria; Mahashabde, Sumedh; Kuzmin, Leonid S; Masi, Silvia

2014-01-01

61

Using a synthetic body fluid (SBF) solution of 27 mM HCO3 to make bone  

E-print Network

(SBF) solution, mimicking the human blood plasma, with the following ion concentrations of 27 mM HCO3-called biomimetic conditions of 37 °C and pH 7.4. This solution was named as Tris­SBF-27 mM. Firstly, collagen development of synthetic or simulated body fluids (SBF, which claim to mimic the acellular human blood plasma

Tas, A. Cuneyt

62

Changes of the solution pH due to exposure by high-voltage electric pulses  

Microsoft Academic Search

The change of the pH of a NaCl solution (139–149 mM NaCl) buffered with 5–15 mM sodium phosphates (pH 7.4) during electromanipulation was studied. It has been determined that an increase in the pH value of electroporation solution of a whole chamber volume, caused by the application of electric field pulses, commonly used in cell electromanipulation procedures, can exceed 1–2

Gintautas Saulis; Remigijus Lap?; Rita Pranevi?i?t?; Donatas Mickevi?ius

2005-01-01

63

Effect of temperature, pH, and ions on sweet taste  

Microsoft Academic Search

The purpose of this experiment was to determine the effects of temperature (50°C and 6°C), pH (pH 3.0, 4.0, 5.0, 6.0, and 7.0) and the addition of monovalent and divalent cations (5 mM Na+ , 5 mM K+ , and 5 mM Ca2+ ) on the sweetness intensity ratings of sweeteners ranging widely in chemical structure. A trained panel provided

Susan S. Schiffman; Brevick G. Graham; Jeanette L. Bennett; Barbara J. Booth; Nitin Desai; Ihab Bishay

2000-01-01

64

Monday Tuesday Wednesday Thursday Friday PH 1110 PH 1110  

E-print Network

Monday Tuesday Wednesday Thursday Friday PH 1110 PH 1110 Muhammad Muhammad CS 1101 CS 1101 CS 1101 Mairaj Mairaj Mairaj Ph 1111 Ph 1111 PH 1111 Zhen Zhen Zhen CH 1010 CH 1010 Elisabeth Elisabeth MA 1023 MA 1021 MA 1023 MA 1021 Kushi Han Li Murtaza Jeffrey MA 1021 MA 1023 PH 1110 Han Li Murtaza Muhammad

Weekes, Suzanne L.

65

pH Calculation  

NSDL National Science Digital Library

This pair of pH calculation programs serves as an excellent tool for anyone wishing to calculate the pH of a solution containing multiple acids and bases. These programs allow practitioners to predict the pH of simple and complex acid/base solutions and buffers. They may be downloaded free of charge via the website. Users are encouraged to carefully read the guides provided by the author.

Johansson, Stig

66

Teaching Evolutionary Mechanisms: Genetic Drift and M&M's.  

ERIC Educational Resources Information Center

Describes a classroom activity that teaches the mechanism of genetic drift to undergraduates. Illustrates a number of concepts that are critical in developing evolution literacy by sampling M&M milk chocolate candies. (MM)

Staub, Nancy L.

2002-01-01

67

pH Scale  

NSDL National Science Digital Library

Test the pH of things like coffee, spit, and soap to determine whether each is acidic, basic, or neutral. Visualize the relative number of hydroxide ions and hydronium ions in solution. Switch between logarithmic and linear scales. Investigate whether changing the volume or diluting with water affects the pH. Or you can design your own liquid!

Simulations, Phet I.; Adams, Wendy; Barbera, Jack; Langdon, Laurie; Loeblein, Patricia; Malley, Chris

2008-07-01

68

Title: Deterministic Mathematical Morphology Acronym: MM instructor(s)  

E-print Network

: 2014 to: Frequency: 2 Maximum number of participants: 14 Proposed location room CAO Room, R and Spectrum MM operators : algebraic point of view MM operators : scale point of view Signal denoising with MM A new point of view on Topology Connections Geodesic morphology Focus on reconstruction Around levelling

Jeanjean, Louis

69

Isolation and characterization of a Pseudomonas sp. strain PH1 utilizing meta-aminophenol.  

PubMed

Pseudomonas sp. strain PH1 was isolated from soil contaminated with pharmaceutical and dye industry waste. The isolate PH1 could use m-aminophenol as a sole source of carbon, nitrogen, and energy to support the growth. PH1 could degrade up to 0.32 mM m-aminophenol in 120 h, when provided as nitrogen source at 0.4 mM concentration with citrate (0.5 mM) as a carbon source in the growth medium. The presence of ammonium chloride as an additional nitrogen source repressed the degradation of m-aminophenol by PH1. To identify strain PH1, the 16S rDNA sequence was amplified by PCR using conserved eubacterial primers. The FASTA program was used to analyze the 16S rDNA sequence and the resulting homology patterns suggested that PH1 is a Pseudomonas. PMID:10749534

Kutty, R; Purohit, H J; Khanna, P

2000-03-01

70

(4 mg) was concentrated by vacuum dialysis against 100 mM KCl, 100 mM NaCl, 5 mM potassium phosphate (pH  

E-print Network

)diplatinum nitrate derivative (PIP) at 7.0 Ã? resolu- tion. Single-isomorphous-replacement phases were then used calculated by using PIP and SmCl3-free data sets; for the latter, we refined negative Sm3 occupancies) either on image plates or on the Quantum-4 CCD detector. All data were processed with the HKL suite (26

Vale, Ronald D.

71

Ph.D. Manual PH.D. PROGRAM  

E-print Network

Ph.D. Manual 1 PH.D. PROGRAM IN SCHOOL PSYCHOLOGY Manual of Policies and Procedures College://www.lehigh.edu/education/sp/phd_sp.html Approved: May 1985 Last Revision: July 2010 #12;Ph.D. Manual 2 Table of Contents Program Philosophy..................................................................................... 3 Differentiation of Ph.D. & Ed.S. Programs................................................... 8

Gilchrist, James F.

72

The growth technology for 300 mm single crystal silicon  

Microsoft Academic Search

The fabrication technique for 300 mm silicon single crystals and wafers is the central topic of silicon material research recently. The study on the growth technique of 300 mm silicon ingots has been developed in our institute since 1997. The research mainly focuses on the following aspects: (1) process conditions for fabrication of the dislocation-free silicon single crystal; (2) oxygen

H Tu; Q Zhou; G Zhang; J Wang; Q Chang; F Qin; F Fang; Z Wu; G Wan

2001-01-01

73

The pH Game  

NSDL National Science Digital Library

This learning activity engages students in measurement of pH in water and soil samples, plants and other natural materials. By mixing different substances, they observe how pH changes, and become familiar with the pH of common household products. Through discussion, they learn how pH can be modified in the environment.

74

40 CFR Table Mm-1 to Subpart Mm of... - Default Factors for Petroleum Products and Natural Gas Liquids 1 2  

...2014-07-01 false Default Factors for Petroleum Products and Natural Gas Liquids 1 2...GREENHOUSE GAS REPORTING Suppliers of Petroleum Products Pt. 98, Subpt. MM, Table...MM of Part 98—Default Factors for Petroleum Products and Natural Gas Liquids 1...

2014-07-01

75

40 CFR Table Mm-1 to Subpart Mm of... - Default Factors for Petroleum Products and Natural Gas Liquids 1 2  

Code of Federal Regulations, 2013 CFR

...2013-07-01 false Default Factors for Petroleum Products and Natural Gas Liquids 1 2...GREENHOUSE GAS REPORTING Suppliers of Petroleum Products Pt. 98, Subpt. MM, Table...MM of Part 98—Default Factors for Petroleum Products and Natural Gas Liquids 1...

2013-07-01

76

40 CFR Table Mm-1 to Subpart Mm of... - Default Factors for Petroleum Products and Natural Gas Liquids 1 2  

Code of Federal Regulations, 2012 CFR

...2012-07-01 false Default Factors for Petroleum Products and Natural Gas Liquids 1 2...GREENHOUSE GAS REPORTING Suppliers of Petroleum Products Pt. 98, Subpt. MM, Table...MM of Part 98—Default Factors for Petroleum Products and Natural Gas Liquids 1...

2012-07-01

77

40 CFR Table Mm-1 to Subpart Mm of... - Default Factors for Petroleum Products and Natural Gas Liquids 1 2  

Code of Federal Regulations, 2011 CFR

...2011-07-01 false Default Factors for Petroleum Products and Natural Gas Liquids 1 2...GREENHOUSE GAS REPORTING Suppliers of Petroleum Products Pt. 98, Subpt. MM, Table...MM of Part 98—Default Factors for Petroleum Products and Natural Gas Liquids 1...

2011-07-01

78

Japanese Science Films; a Descriptive and Evaluative Catalog of: 16mm Motion Pictures, 8mm Cartridges, and Video Tapes.  

ERIC Educational Resources Information Center

One hundred and eighty Japanese 16mm motion pictures, 8mm cartridges, and video tapes produced and judged appropriate for a variety of audience levels are listed in alphabetical order by title with descriptive and evaluative information. A subject heading list and a subject index to the film titles are included, as well as a sample of the…

Newren, Edward F., Ed.

79

pH optrode  

DOEpatents

A process is provided for forming a long-lasting, stable, pH-sensitive dye-acrylamide copolymer useful as a pH-sensitive material for use in an optrode or other device sensitive to pH. An optrode may be made by mechanically attaching the copolymer to a sensing device such as an optical fiber.

Northrup, M. Allen (Berkeley, CA); Langry, Kevin C. (Tracy, CA)

1993-01-01

80

Ph.D. shortage  

NASA Astrophysics Data System (ADS)

The late 1990s will see a shortage of Ph.D. graduates, according to the Association of American Universities, Washington, D.C. AAU's new comprehensive study, “The Ph.D. Shortage: The Federal Role,” reports that competition for new Ph.D.s is already intense and can only intensify because demand is greater than supply in both academic and nonacademic markets.Doctoral education plays an increasingly important role in U.S. research and development programs. Students have a pivotal part in doing research and enriching it with new ideas. The AAU report says that graduate students are “major determinants of the creativity and productivity of U.S. academic research, the source of more than 50% of the nation's basic research.’ The market for doctoral education extends beyond the university. In 1985, about 43% of all Ph.D.s employed in this country were working outside higher education; the demand for doctorate recipients in nonacademic sectors continues to grow.

81

The 19 mm data recorders similarities and differences  

NASA Technical Reports Server (NTRS)

Confusion over the use of non-video 19 mm data recorders is becoming more pronounced as we enter the world of high performance computing. This paper addresses the following: the differences between ID-1, ID-2, MIL-STD-2179 and DD-2; what the proper machine is for various applications; how the machine can be integrated into an environment; and any misconceptions there might be about 19 mm tape recorders. DD-2 and 19 mm instrumentation recorders have missions for which each is well designed. While the differences may appear subtle, understanding the difference between the two is the key to picking the right recorder for a particular application.

Atkinson, Steve

1992-01-01

82

663 900 1000 1100 1200 3514 Annual precipitation (mm)  

E-print Network

663 900 1000 1100 1200 3514 Annual precipitation (mm) -72.6 -71.5 -70.3 -69.2 -68.1 42 precipitation (mm) -72.6 -71.5 -70.3 -69.2 -68.1 42.143.144.245.346.4 Longitude (degree) Latitude(degree) (b) Baseline (1961-1990) 663 900 1000 1100 1200 3514 Annual precipitation (mm) -72.6 -71.5 -70.3 -69.2 -68.1 42

Beckage, Brian

83

17-4 PH and 15-5 PH  

NASA Technical Reports Server (NTRS)

17-4 PH and 15-5 PH are extremely useful and versatile precipitation-hardening stainless steels. Armco 17-4 PH is well suited for the magnetic particle inspection requirements of Aerospace Material Specification. Armco 15-5 PH and 17-4 PH are produced in billet, plate, bar, and wire. Also, 15-5 PH is able to meet the stringent mechanical properties required in the aerospace and nuclear industries. Both products are easy to heat treat and machine, making them very useful in many applications.

Johnson, Howard T.

1995-01-01

84

Advanced Applications Flight Equipment (AAFE) 125mm ultraviolet spectrometer  

NASA Technical Reports Server (NTRS)

The conceptual work is reported for the 125 mm ultraviolet spectrometer to measure atmospheric ozone as a function of height, latitude, and time. The instrument is described along with the assembly, test, and calibration.

Schroeder, R. J.

1973-01-01

85

Building 932, oblique view to northwest, 90 mm lens. Building ...  

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

Building 932, oblique view to northwest, 90 mm lens. Building 933-935 at extreme left. - Travis Air Force Base, Nuclear Weapons Assembly Plant 5, W Street, Armed Forces Special Weapons Project Q Area, Fairfield, Solano County, CA

86

Building 931, oblique view to northwest, 210 mm lens. ...  

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

Building 931, oblique view to northwest, 210 mm lens. - Travis Air Force Base, Central Battery Charging Building, North of W Street, Armed Forces Special Weapons Project Q Area, Fairfield, Solano County, CA

87

Building 931, oblique view to southeast, 135 mm lens. ...  

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

Building 931, oblique view to southeast, 135 mm lens. - Travis Air Force Base, Central Battery Charging Building, North of W Street, Armed Forces Special Weapons Project Q Area, Fairfield, Solano County, CA

88

The 19 mm date recorders: Similarities and differences  

NASA Technical Reports Server (NTRS)

Confusion over the use of non-video 19 mm data recorders is becoming more pronounced in the world of high performance computing. The following issues are addressed: (1) the difference between ID-1, ID-2, MIL-STD-2179, and DD-2; (2) the proper machine for the necessary application; and (3) integrating the machine into an existing environment. Also, an attempt is made to clear up any misconceptions there might be about 19 mm tape recorders.

Atkinson, Steve

1991-01-01

89

Combined quantum and molecular mechanics (QM/MM).  

PubMed

We describe the current state of the art of mixed quantum mechanics/molecular mechanics (QM/MM) methodology, with a particular focus on modeling of enzymatic reactions. Over the past decade, the effectiveness of these methods has increased dramatically, based on improved quantum chemical methods, advances in the description of the QM/MM interface, and reductions in the cost/performance of computing hardware. Two examples of pharmaceutically relevant applications, cytochrome P450 and class C ?-lactamase, are presented.: PMID:24981493

Friesner, Richard A

2004-12-01

90

Microcalorimeter for 3.5 mm 50 ? coaxial transmission line  

Microsoft Academic Search

At PTB a microcalorimeter has been installed for calibrating RF power mounts with 3.5 mm precision 50 ? coaxial connectors (PC-3.5) to be used as power standards up to 26.5 GHz. Two detachable inserts with 3.5 mm coaxial transmission lines for a twin-type microcalorimeter have been developed. Measurements of bolometer mounts fitted with PC-3.5 adaptors and of a PC-3.5 power

D. Janik

1996-01-01

91

Single Queuing Systems M/M/1 queuing system  

E-print Network

64 Single Queuing Systems M/M/1 queuing system -- arrival process is a Poisson process (or) inter-arrival time density (t) = T is an exponentially distributed r.v. no arrivals in a time interval-t) t t 1-t t M/M/1 #12;72 )()()()( )( 11 tPtPtP dt tdP nnn n n-1 n+1n flows into state flows out

Chen, Ing-Ray

92

Particle trackers based on 1 mm and 0.7 mm scintillating fibers readout by a multi-anode photomultiplier  

NASA Astrophysics Data System (ADS)

A prototype particle tracking detector was constructed at LNF with 1 mm and 0.7 mm plastic scintillating fibers with a 64 channel Hamamatsu H7546A-200 Ultra-bialkali flat-panel multi-anode photomultiplier readout. Cosmic ray tracks from an array of 11 gas-filled drift tubes were matched to signals in the scintillating fibers in order to measure the resolution and efficiency of tracks reconstructed in the fiber-based tracker. The fibers allow for two possible readout methods, a hit-based (digital) and an amplitude-based (analog) mode. A GEANT4 detector simulation was also developed to compare cosmic ray data with Monte Carlo results. These fiber tracker designs are suggested as a way to meet the resolution and efficiency goals of modern detectors, such as an upgraded LHCb Outer Tracker. Resolutions for the fiber trackers were found to be 0.236 mm and 0.175 mm for the 1 mm and 0.7 mm trackers, respectively, in analog mode.

Leverington, Blake; Rosellini, Rossano; Anelli, Mario; Campana, Pierluigi

2013-08-01

93

MM Caregiver Grief Inventory Thomas M. Meuser, Ph.D., University of Missouri St. Louis Samuel J. Marwit, Ph.D., University of Missouri-St. Louis (Emeritus)  

E-print Network

.g., Alzheimer's disease). Read each statement carefully, then decide how much you agree or disagree with what you know doctors can't cure this disease, so things only get worse. 1 2 3 4 5 B 38 I've lost other

94

Influence of pH on Ammonia Accumulation and Toxicity in Halophilic, Methylotrophic Methanogens  

PubMed Central

We studied the effects of pH and ammonia concentration on the growth of three methanogens. These three halophilic, methylotrophic methanogens, Methanolobus bombayensis, Methanolobus taylorii, and Methanohalophilus zhilinaeae, grew at environmental pH ranges that overlapped with each other and spanned the pH range from 7.0 to 9.5. During growth they had reversed membrane pH gradients ((Delta)pH) at all pH values tested. The (Delta)pH was in the range of -0.4 to -0.9 pH units, with the cytosol being more acidic than the environmental pH. Methanohalophilus zhilinaeae had the most negative (Delta)pH (-0.9 pH units). These negative pH gradients resulted in the accumulation of ammonium (NH(inf4)(sup+)), and when grown at the highest external ammonia concentrations that allowed good growth, cells had cytosolic NH(inf4)(sup+) concentrations as high as 180 mM. The high concentrations of cytosolic NH(inf4)(sup+) were accompanied by greater (Delta)pH and lower concentrations of the major cytosolic cation K(sup+) (compared with cells grown in medium with only 5 mM ammonia). Methanolobus bombayensis and Methanolobus taylorii were more sensitive to total external ammonia at higher external pH values, but the inhibitory concentration of un-ionized ammonia that resulted in a 50% reduction of the growth rate was about 2 to 5 mM, regardless of the pH. This is consistent with growth inhibition by ammonia in other bacteria. However, Methanohalophilus zhilinaeae was more resistant to un-ionized ammonia than any other known organism. It had a 50% inhibitory concentration for un-ionized ammonia of 13 mM at pH 8.5 and 45 mM at pH 9.5. We examined the effects of pH on three ammonia-assimilating activities (glutamine synthetase, glutamate dehydrogenase, and alanine dehydrogenase) in cell lysates and found that the pH ranges were consistent with the observed ranges of intracellular pH. PMID:16535465

Kadam, P. C.; Boone, D. R.

1996-01-01

95

GBT 3mm Observations in the ALMA-Era  

NASA Astrophysics Data System (ADS)

We discuss the current capabilities and instrumentation under development covering the 3mm atmospheric window from 67--115.3 GHz for the Robert C. Byrd Green Bank Telescope (GBT). The current GBT 4mm receiver operates from 67 GHz to 93 GHz and has comparable sensitivity to ALMA Cycle-1 at 84-90 GHz. Within the 3mm window below 84 GHz (ALMA has no frequency coverage below 84 GHz), no facility in the world comes close to matching the GBT sensitivity. The development of 3mm multi-pixel cameras such as Argus and Mustang will greatly improve the spectral-line and continuum mapping capabilities of the GBT. Although ALMA will provide excellent sensitivity at sub-arcsec resolution over small areas, multi-pixel cameras on the GBT will greatly improve the available mapping speeds for large areas at 3mm. The GBT surveys will provide targets for detailed follow-up ALMA studies, and the GBT could provide sensitive short-spacing data for GBT+ALMA imaging. The GBT is operated by the National Radio Astronomy Observatory and is currently a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc.

Frayer, David T.; Mason, B. S.; Maddalena, R. J.

2013-06-01

96

Esophageal pH monitoring  

MedlinePLUS

pH monitoring - esophageal; Esophageal acidity test ... to stay in the hospital for the esophageal pH monitoring. ... Esophageal pH monitoring is used to check how much stomach acid is entering the esophagus. It also checks how ...

97

The pH scale  

NSDL National Science Digital Library

Some animals tolerate broad changes in pH well while others do not. Human activities can create acid rain. Acid rain can change the pH of the environment and destroy entire ecosystems and habitats. For an ecosystem to function properly, its pH must be able to accommodate all of the organisms living in it.

Olivia Worland (Purdue University;Biological Sciences)

2008-05-26

98

(ISLiM) 2011 (2011.12.21-22) Platypus MM/CG  

E-print Network

#12;15 (ISLiM) 2011 (2011.12.21-22) 1 Platypus MM/CG 1982 3 1982 8 Cornell 1986 2 1988 4 1996 4 2001 4 2006 10 2011 4 HPCI #12;16 (ISLiM) 2011 (2011.12.21-22) 2 Platypus MM/CG 1. QM MM MM CG QM-MM-CG 3 QM MM QM/MM MM CG MM/CG 2. 2.1 ProteinDF QM DFT B3LYP 8,000 6 c 2.2 Platypus-QM/MM QM/MM QM MM QM

Fukai, Tomoki

99

450mm wafer patterning with jet and flash imprint lithography  

NASA Astrophysics Data System (ADS)

The next step in the evolution of wafer size is 450mm. Any transition in sizing is an enormous task that must account for fabrication space, environmental health and safety concerns, wafer standards, metrology capability, individual process module development and device integration. For 450mm, an aggressive goal of 2018 has been set, with pilot line operation as early as 2016. To address these goals, consortiums have been formed to establish the infrastructure necessary to the transition, with a focus on the development of both process and metrology tools. Central to any process module development, which includes deposition, etch and chemical mechanical polishing is the lithography tool. In order to address the need for early learning and advance process module development, Molecular Imprints Inc. has provided the industry with the first advanced lithography platform, the Imprio® 450, capable of patterning a full 450mm wafer. The Imprio 450 was accepted by Intel at the end of 2012 and is now being used to support the 450mm wafer process development demands as part of a multi-year wafer services contract to facilitate the semiconductor industry's transition to lower cost 450mm wafer production. The Imprio 450 uses a Jet and Flash Imprint Lithography (J-FILTM) process that employs drop dispensing of UV curable resists to assist high resolution patterning for subsequent dry etch pattern transfer. The technology is actively being used to develop solutions for markets including NAND Flash memory, patterned media for hard disk drives and displays. This paper reviews the recent performance of the J-FIL technology (including overlay, throughput and defectivity), mask development improvements provided by Dai Nippon Printing, and the application of the technology to a 450mm lithography platform.

Thompson, Ecron; Hellebrekers, Paul; Hofemann, Paul; LaBrake, Dwayne L.; Resnick, Douglas J.; Sreenivasan, S. V.

2013-09-01

100

Performance evaluation of 4.75-mm NMAS superpave mixture  

NASA Astrophysics Data System (ADS)

A Superpave asphalt mixture with 4.75-mm nominal maximum aggregate size (NMAS) is a promising, low-cost pavement preservation treatment for agencies such as the Kansas Department of Transportation (KDOT). The objective of this research study is to develop an optimized 4.75-mm NMAS Superpave mixture in Kansas. In addition, the study evaluated the residual tack coat application rate for the 4.75-mm NMAS mix overlay. Two, hot-in-place recycling (HIPR) projects in Kansas, on US-160 and K-25, were overlaid with a 15- to 19-mm thick layer of 4.75-mm NMAS Superpave mixture in 2007. The field tack coat application rate was measured during construction. Cores were collected from each test section for Hamburg wheel tracking device (HWTD) and laboratory bond tests performed after construction and after one year in service. Test results showed no significant effect of the tack coat application rate on the rutting performance of rehabilitated pavements. The number of wheel passes to rutting failure observed during the HWTD test was dependent on the aggregate source as well as on in-place density of the cores. Laboratory pull-off tests showed that most cores were fully bonded at the interface of the 4.75-mm NMAS overlay and the HIPR layer, regardless of the tack application rate. The failure mode during pull-off tests at the HMA interface was highly dependent on the aggregate source and mix design of the existing layer material. This study also confirmed that overlay construction with a high tack coat application rate may result in bond failure at the HMA interface. Twelve different 4.75-mm NMAS mix designs were developed using materials from the aforementioned but two binder grades and three different percentages of natural (river) sand. Laboratory performance tests were conducted to assess mixture performance. Results show that rutting and moisture damage potential in the laboratory depend on aggregate type irrespective of binder grade. Anti-stripping agent affects moisture sensitivity test results. Fatigue performance is significantly influenced by river sand content and binder grade. Finally, an optimized 4.75-mm NMAS mixture design was developed and verified based on statistical analysis of performance data.

Rahman, Farhana

101

IMPLEMENTATION OF AN URBAN CANOPY PARAMETERIZATION IN MM5  

EPA Science Inventory

The Pennsylvania State University/National Center for Atmospheric Research Mesoscale Model (MM5) (Grell et al. 1994) has been modified to include an urban canopy parameterization (UCP) for fine-scale urban simulations (~1-km horizontal grid spacing). The UCP accounts for drag ...

102

News & Notes Paul Boyd (DMA, Music Education, 2008; MM, Performance  

E-print Network

News & Notes Paul Boyd (DMA, Music Education, 2008; MM, Performance 1990, from the studios of Abbey FMM's season opening concert benefiting music programs in New Orleans and Houston, the Greenbriar. He presented two papers at the Tenth Interna- tional Research Symposium on Talent Education

Azevedo, Ricardo

103

ETC Ignition Research on 120 mm Gun in Korea  

Microsoft Academic Search

An electrothermal-chemical (ETC) propulsion with the control of a combustion process yet requires large electrical energies for an appreciable effect. Referring to the changed tendency of focusing ETC researches on the early ignition phase, ADD (Agency for Defense Development), Korea has been studying an electrothermal ignition for a 120 mm gun using a capillary plasma injector. Under the condition of

Seong Ho Kim; Kyung Seung Yang; Young Hyun Lee; Jin Sung Kim; Byung Ha Lee

2008-01-01

104

FISHERY STATISTICS I OF THE UNITED STATESmmmMM  

E-print Network

^^ FISHERY STATISTICS I OF THE UNITED STATESmmmMM 'f^ gjIP^Ws^WI'l STATISTICAL DIGEST NO. 25 Fish Statistical Digest 25 FISHERY STATISTICS OF THE UNITED STATES 1949 BY A. W. ANDERSON and C. E. PETERSON UNITED. Government Printing Office, Washington 25, D. C. - - - Price $1.25 (paper) #12;Fishery Statistics

105

Guide to Films (16 mm) About Ecology, Adaptation and Pollution.  

ERIC Educational Resources Information Center

Synopses of 350 films (16 mm.) on ecology, adaptation of plants and animals to their environment, and environmental pollution are listed alphabetically by title in this guide. It specifies whether the film is black-and-white or color, its running time, and its source. An abbreviated subject index and a directory of sources are also provided. The…

1971

106

Dendrochronology Looking Through a 5mm Window of the Past  

E-print Network

Dendrochronology Looking Through a 5mm Window of the Past to Predict the Future By: Andy Burnside #12;Abstract The practice of dendrochronology has been a source for dating tree for many years and scientists used the practice of dendrochronology, the technique of dating environmental changes and events

Polly, David

107

Evaluating Patron Satisfaction at the M.M. Bennett Library.  

ERIC Educational Resources Information Center

Discusses a user satisfaction survey distributed to patrons of the M.M. Bennett Library at St. Petersburg College (Florida). Reports that satisfaction with reference assistance has varied, although there has been an improvement in the rating of library instructions since this question was first posed in 1999. Suggests that paper surveys are easier…

Barbier, Pat

2003-01-01

108

Mineralogic Model (MM3.0) Analysis Model Report  

SciTech Connect

The purpose of this report is to document the Mineralogic Model (MM), Version 3.0 (MM3.0) with regard to data input, modeling methods, assumptions, uncertainties, limitations and validation of the model results, qualification status of the model, and the differences between Version 3.0 and previous versions. A three-dimensional (3-D) Mineralogic Model was developed for Yucca Mountain to support the analyses of hydrologic properties, radionuclide transport, mineral health hazards, repository performance, and repository design. Version 3.0 of the MM was developed from mineralogic data obtained from borehole samples. It consists of matrix mineral abundances as a function of x (easting), y (northing), and z (elevation), referenced to the stratigraphic framework defined in Version 3.1 of the Geologic Framework Model (GFM). The MM was developed specifically for incorporation into the 3-D Integrated Site Model (ISM). The MM enables project personnel to obtain calculated mineral abundances at any position, within any region, or within any stratigraphic unit in the model area. The significance of the MM for key aspects of site characterization and performance assessment is explained in the following subsections. This work was conducted in accordance with the Development Plan for the MM (CRWMS M&O 2000). The planning document for this Rev. 00, ICN 02 of this AMR is Technical Work Plan, TWP-NBS-GS-000003, Technical Work Plan for the Integrated Site Model, Process Model Report, Revision 01 (CRWMS M&O 2000). The purpose of this ICN is to record changes in the classification of input status by the resolution of the use of TBV software and data in this report. Constraints and limitations of the MM are discussed in the appropriate sections that follow. The MM is one component of the ISM, which has been developed to provide a consistent volumetric portrayal of the rock layers, rock properties, and mineralogy of the Yucca Mountain site. The ISM consists of three components: (1) Geologic Framework Model (GFM); (2) Rock Properties Model (RPM); and (3) Mineralogic Model (MM). The ISM merges the detailed stratigraphy and structural features of the site into a 3-D model that will be useful in primary downstream models and repository design. These downstream models include the hydrologic flow models and the radionuclide transport models. All the models and the repository design, in turn, will be incorporated into the Total System Performance Assessment (TSPA) of the potential nuclear waste repository block and vicinity to determine the suitability of Yucca Mountain as a host for a repository. The interrelationship of the three components of the ISM and their interface with downstream uses are illustrated in Figure 1. The lateral boundaries of the ISM and its three component models are shown in Figure 2.

C. Lum

2002-02-12

109

Hickey -TT174, casts 1 to cast 11 Cruise cast lat (dd.mm.m) lon(dd.mm.m) Date/Time (MMDDYYHHMM) Total Scan  

E-print Network

Hickey -TT174, casts 1 to cast 11 Cruise cast lat (dd.mm.m) lon(dd.mm.m) Date/Time (MMDDYYHHMM;Hickey -TT174, casts 1 to cast 11 Cruise cast lat (dd.mm.m) lon(dd.mm.m) Date/Time (MMDDYYHHMM) Total -TT174, casts 1 to cast 11 Cruise cast lat (dd.mm.m) lon(dd.mm.m) Date/Time (MMDDYYHHMM) Total Scan

Hickey, Barbara

110

FT-Raman and QM/MM study of the interaction between histamine and DNA  

NASA Astrophysics Data System (ADS)

The interaction between histamine and highly polymerized calf-thymus DNA has been investigated using FT-Raman spectroscopy and the hybrid QM/MM (quantum mechanics/molecular mechanics) methodology. Raman spectra of solutions containing histamine and calf-thymus DNA, at different molar ratios, were recorded. Solutions were prepared at physiological settings of pH and ionic strength, using both natural and heavy water as the solvent. The analysis of the spectral changes on the DNA Raman spectra when adding different concentrations of histamine allowed us to identify the reactive sites of DNA and histamine, which were used to built two minor groove and one intercalated binding models. They were further used as starting points of the QM/MM theoretical study. However, minimal energy points were only reached for the two minor groove models. For each optimized structure, we calculated analytical force constants of histamine molecule in order to perform the vibrational dynamics. Normal mode descriptions allowed us to compare calculated wavenumbers for DNA-interacting histamine to those measured in the Raman spectra of DNA-histamine solutions.

Ruiz-Chica, A. J.; Soriano, A.; Tuñón, I.; Sánchez-Jiménez, F. M.; Silla, E.; Ramírez, F. J.

2006-05-01

111

Resistance of Streptococcus bovis to acetic acid at low pH: Relationship between intracellular pH and anion accumulation  

SciTech Connect

Streptococcus bovis JB1, an acid-tolerant ruminal bacterium, was able to grown at pHs from 6.7 to 4.5, and 100 mM acetate had little effect on growth rate or proton motive force across the cell membrane. When S. bovis was grown in glucose-limited chemostats at pH 5.2, the addition of sodium acetate (as much as 100 mM) had little effect on the production of bacterial protein. At higher concentrations of sodium acetate (100 to 360 mM), production of bacterial protein declined, but this decrease could largely be explained by a shift in fermentation products (acetate, formate, and ethanol production to lactate production) and a decline in ATP production (3 ATP per glucose versus 2 ATP per glucose). Y{sub ATP} (grams of cells per mole at ATP) was not decreased significantly even by high concentrations of acetate. Cultures supplemented with 100 mM sodium acetate took up ({sup 14}C)acetate and ({sup 14}C)benzoate in accordance with the Henderson-Hasselbalch equation and gave similar estimates of intracellular pH. As the extracellular pH declined, S. bovis allowed its intracellular pH to decrease and maintained a relatively constant pH gradient across the cell membrane (0.9 unit). The decrease in intracellular pH prevented S. bovis from accumulating large amounts of acetate anion. On the basis of these results it did not appear that acetate was acting as an uncoupler. The sensitivity of other bacteria to volatile fatty acids at low pH is explained most easily by a high transmembrane pH gradient and anion accumulation.

Russell, J.B. (Cornell Univ., Ithaca, NY (USA))

1991-01-01

112

Integrated blood-gas sensor for pO2, pCO2 and pH  

Microsoft Academic Search

The fabrication and characterization of a combined pOz, pCOl and pH chemical sensor, designed for blood-gas monitoring, are discussed. Classical electrochemical principles are used in a miniaturized planar-type structure. Both amperometric (PO,) and potentiometric devices (pCOr, pH) are integrated on a 10 mm x 10 mm chip. The transducer part of the chip is realized using standard silicon technology. Polyacrylamide

A. van den Berg; B. H. van der Schoot; N. F. de Rooij; H. Biihler; W. E. Morf; L. F. J. Diirselen; L. F. J. Dürselen

1993-01-01

113

14 mmHg: a case of raised intracranial pressure?  

PubMed

A 40-year-old woman presented with chronic headaches. She had undergone ventriculo-peritoneal (VP) shunt 7 years previously for treatment of hydrocephalus secondary to aqueduct stenosis. Intracranial pressure (ICP) monitoring revealed a resting ICP of less than 5 mmHg. Headaches were thought to be due to low ICP and the shunt tubing was ligated. Over the next 4 h there was an increase in ICP to 14 mmHg, decrease in GCS to 13 and ventriculomegaly on CT. These changes were reversed by the removal of the ligature. This unusual case highlights the fact that, in some shunted patients with over drainage of ventricles and a low resting ICP, small increases in ICP are poorly tolerated. This may be due to altered visco-elastic properties of the ventricles and the brain parenchyma. PMID:15327239

Gnanalingham, K K; Watkins, L; Goadsby, P J

2004-06-01

114

Emission properties of pulsars at mm-wavelengths  

Microsoft Academic Search

Pulsar polarimetric observations, conducted at the highest frequency ever, 32GHz, have been used to probe the emission properties of pulsar radiation at mm-wavelengths. The sample consists of eight nearby, relatively-young pulsars, located above the 5-Myr luminosity line. The flatter spectral indices characterizing the pulsars in this sample do not show any correlation with observed and derived parameters often used to

K. M. Xilouris; M. Kramer; A. Jessner; R. Wielebinski; M. Timofeev

1996-01-01

115

Latest developments with the 400 MM bore Pielstick engine  

Microsoft Academic Search

For over forty years, S.E.M.T. Pielstick has been manufacturing the 400 mm bore, four-stroke, medium-speed PC diesel engine. The evolution has continued up to the present and the latest issue is the PC2-6B design, featuring an output of 615 kW per cylinder. This result was made possible by a multifold, ongoing development program. Experience, gained on the nearly 4000 PC

Chellini

1995-01-01

116

Advancements and Future of Tribology from IFToMM  

Microsoft Academic Search

\\u000a A Tribology Committee, focused on tribology in machines, was set up in 2005 as a Technical committee of the IFToMM, an organization\\u000a that has historically supported tribological activities. Tribology has been developed very rapidly in the last 20 years. Several\\u000a new areas have been identified, such as nano-tribology, bio-tribology, superlubricity, and surface texture. In the present\\u000a and following years, these

Jianbin Luo

117

SUPPORTING INFORMATION METHODS Buffers. Buffer U is 20 mM TrisHCl, 6 mM NaCl, 1.7 mM MgCl2, 5 mM 2-mercaptoethanol (2-ME),  

E-print Network

LB broth in a 250 ml flask so that each flask had the same initial optical density at 600 nm (OD600 by addition of IPTG (300 mg/ml final concentration) and growth was continued at 37°C for 2 hours. The cells was added to a final concentration of 0.1 mM and lysozyme was added to a final concentration of 0.4 mg

Lohman, Timothy M.

118

Projected Hybrid Orbitals: A General QM/MM Method.  

PubMed

A projected hybrid orbital (PHO) method was described to model the covalent boundary in a hybrid quantum mechanical and molecular mechanical (QM/MM) system. The PHO approach can be used in ab initio wave function theory and in density functional theory with any basis set without introducing system-dependent parameters. In this method, a secondary basis set on the boundary atom is introduced to formulate a set of hybrid atomic orbtials. The primary basis set on the boundary atom used for the QM subsystem is projected onto the secondary basis to yield a representation that provides a good approximation to the electron-withdrawing power of the primary basis set to balance electronic interactions between QM and MM subsystems. The PHO method has been tested on a range of molecules and properties. Comparison with results obtained from QM calculations on the entire system shows that the present PHO method is a robust and balanced QM/MM scheme that preserves the structural and electronic properties of the QM region. PMID:25317748

Wang, Yingjie; Gao, Jiali

2015-01-22

119

Ph.D. Astronomy Program Ph.D. in Astronomy  

E-print Network

Ph.D. Astronomy Program Ph.D. in Astronomy Department(s) Physics and Astronomy College Sciences 1 physics at the graduate level 4. understand observational astronomy techniques 5. understand astrophysics strong background of knowledge and expertise in physics and astronomy #12;2. Curriculum Alignment

Hemmers, Oliver

120

Ph.D. Physics Program Ph.D. in Physics  

E-print Network

Ph.D. Physics Program Ph.D. in Physics Department(s) Physics and Astronomy College Sciences Program Assessment Coordinator Michael Pravica pravica@physics.unlv.edu 895-1723 Five-Year Implementation Dates (2010 for physics at the graduate level 4. understand statistical physics at the graduate level 5. perform

Hemmers, Oliver

121

VLBA Imaging at 7 mm and Linear Polarimetric Observations at 6 cm and 3 mm of Sagittarius A*  

E-print Network

We summarize the results of 7 mm VLBA imaging of Sgr A* and discuss some of the difficulties of accurately constraining the size of Sgr A* with VLBI observations. Our imaging results are fully consistent with the hypothesis that the VLBA image of Sgr A* is a resolved elliptical Gaussian caused by the scattering of an intervening thermal plasma. We show that determination of the minor axis size at 7 mm with the VLBA is very unreliable. We also present new polarimetric observations from the VLA and from the BIMA array of Sgr A*. At 4.8 GHz, we find an upper limit to the polarization of 0.1%. At 86 GHz, we report a marginal detection of $1 \\pm 1$% linear polarization. We discuss the effects of interstellar propagation on the linear polarization and consider the significance of very low intrinsic linear polarization in Sgr A*.

Geoffrey C. Bower; Heino Falcke; Don Backer; Melvyn Wright

1998-11-13

122

The pH Game.  

ERIC Educational Resources Information Center

Describes a game that can be used to teach students about the acidity of liquids and substances around their school and enable them to understand what pH levels tell us about the environment. Students collect samples and measure the pH of water, soil, plants, and other natural material. (DDR)

Chemecology, 1996

1996-01-01

123

Jeanne Murhpy, PhD  

Cancer.gov

Jeanne Murphy, PhD, CNM is a postdoctoral Cancer Prevention Fellow in the Breast and Gynecologic Cancer Research Group in the Division of Cancer Prevention. She comes to BGCRG with a PhD from Johns Hopkins University School of Nursing. She also completed a graduate certificate in Health Disparities and Health Inequality at Johns Hopkins Bloomberg School of Public Health.

124

PhDProgramS BIOENGINEERING  

E-print Network

through a strong interdisciplinary education in engineering, mathematics, medical and biological knowledge is complemented by an educational offer which proposes ad hoc advanced courses specifically projected for PhD audience. The courses are given at the Campus Leonardo. The Ph. D study track is organized in three years

125

Photodynamic therapy for Barrett's esophagus using a 20-mm diameter light-delivery balloon  

NASA Astrophysics Data System (ADS)

Background and Objective: Patients with high grade dysplasia (HGD) in Barrett's esophagus are at a high risk for developing esophageal adenocarcinoma. Esophagectomy is the standard treatment for such patients. The objective of this study was to evaluate the safety and efficacy of photodynamic therapy (PDT) using an improved light delivery balloon for ablation of Barrett's esophagus with high grade dysplasia and/or early cancer. Materials and Methods: 20 patients with HGD or early cancer (19 with HGD, 1 with T1 cancer) received 2 mg/kg of porfimer sodium, intravenously. Two to three days after the injection, laser light was delivered using a cylindrical diffuser inserted inside a 20-mm diameter reflective esophageal PDT balloon. Initially, the balloon was inflated to a pressure of 80 mm Hg. The balloon pressure was gradually reduced to 30 mm Hg. A KTP/dye laser at 630 nm was used as the light source. Light dose of 115 J/cm was delivered at an intensity of 270 mw/cm. Nodules were pre- treated with an extra 50 J/cm using a short diffuser inserted through the scope. Patients were maintained on PPI therapy to keep the gastric pH higher than 4. Eighteen patients required one treatment, while two patients were treated twice. Follow-up consisted of endoscopy with four quadrant biopsies at every 2 cm of the treated area. Thermal ablation was used to treat small residual islands on the follow-ups. The follow-up endoscopies ranged from 6 to 17 months. Results: On follow-up endoscopy, 12 patients had complete replacement of their Barrett's mucosa with neosquamous mucosa. Five patients had residual non-dysplastic Barrett's mucosa, one had indefinite dysplasia, two had low grad dysplasia. There were no residual HGD or cancers. The average length of Barrett's was reduced from 5.4 cm to 1.2 cm. High balloon pressure resulted in wide variation in PDT response among patients. Lower balloon pressures resulted in more consistent destruction of Barrett's mucosa among patients. Five patients developed strictures which responded well to dilations. One patient developed atrial fibrillation which responded to medications. Conclusions: Photodynamic therapy using a 20 mm diameter balloon was effective for ablation of high grade dysplasia and early cancer in Barrett's esophagus. Low balloon inflation pressure was a critical parameter in producing consistent tissue destruction.

Panjehpour, Masoud; Overholt, Bergein F.; Phan, Mary N.; Haydek, John M.; Robinson, Amy R.

2002-06-01

126

Living with Omniback and the 8mm drive  

SciTech Connect

Apollo's OmniBack backup system provides a convenient and effective way of storing network backup information on 8mm tape. In addition it has a journaling facility to write extensive log files, recording the backup process in almost any degree of detail desired. The directory structure and file names used are logical and well-defined. Summary files announce the degree of success of the backup as specified in the work file. The system will run unattended under the UNIX cron command, allowing the backup to be performed during the night when user demands on the network are small and most user files are free.

Jones, M.C.

1990-01-01

127

Performance of 2mm radius straw tube drift cells  

SciTech Connect

The performance of a 128 channel test module made with straw tubes of 2mm radius has been studied in a test beam and with cosmic rays. Different gases were used and for each one the time-to-distance relation and the hit efficiency was measured. Comparison are made between results when two different electronics readouts were used. The information was recorded with 106 MHz FADC units and also with TDCs (50ps resolution). The best resolution, of 135 [mu]m, was obtained using 50% ethane, 50% argon and reading out the information with the TDCs, at an operating HV of 1,750V.

Avery, R.E.; Bantly, J.; Blessing, S.; Buchholz, D.; Gobbi, B.; Liu, Y.; Rajagopalan, S.; Tilden, R. (Northwestern Univ., Chicago, IL (United States)); Martin, M. (Fermi National Accelerator Lab., Batavia, IL (United States))

1993-08-01

128

Description of a new 63-mm diameter gas gun facility  

SciTech Connect

This paper describes a new light gas gun that is just being completed at Sandia National Laboratories, primarily for use in the study of shock initiation and shock properties of explosive materials. This gun was patterned after the 100-mm diameter gas gun at Washington State University. Several unique features have been designed into the facility to make it easier to control and use the gun and to improve shot turnaround time. These are discussed in some detail and initial gun performance information is presented. 4 refs., 5 figs.

Sheffield, S.A.; Dugan, D.W.

1985-01-01

129

The Importance of pH in the Regulation of Ruminal Acetate to Propionate Ratio and Methane Production In Vitro  

Microsoft Academic Search

Grain feeding often causes a decrease in ruminal pH, and experiments were conducted to define the role of pH in regulating the acetate to propionate ratio and production of CH4. Cows that were fed 90% concentrate had lower ruminal pH values (6.22 vs. 6.86), higher VFA concentrations (85 vs. 68 mM ), and lower acetate to propionate ratios (2.24 vs.

J. B. Russell

1998-01-01

130

Acid-induced gelation of whey protein polymers: effects of pH and calcium concentration during polymerization  

Microsoft Academic Search

Heating whey protein dispersions (90°C for 15 min) at low ionic strength and pH values far from isoelectric point (pH>6.5) induced the formation of soluble polymers. The effect of mineral environment during heating on the hydrodynamic characteristics and acid-induced gelation properties of polymers was studied. Whey protein dispersions (80g\\/l) were denatured at different pH (6.5–8.5) and calcium concentrations (0–4mm) according

Michel Britten; Hélène J Giroux

2001-01-01

131

Keiji TANAKA, Ph.D. Hitoshi OKAMOTO, M.D., Ph.D.  

E-print Network

Keiji TANAKA, Ph.D. Hitoshi OKAMOTO, M.D., Ph.D. Atsushi MIYAWAKI, M.D., Ph.D. Tadaharu TSUMOTO, M.D., Ph.D. Shin OHKOUCHI Masao ITO, M.D., Ph.D. Shun-ichi AMARI, D.Eng. Susumu TONEGAWA, Ph Committee Senior Advisor Charles YOKOYAMA, Ph.D. Neural Circuit Function Developmental Gene Regulation

Kazama, Hokto

132

Jacob Bernoulli, Ph.D. Erhard Weigel, Ph.D. Universitt Leipzig 1650  

E-print Network

Jacob Bernoulli, Ph.D. Erhard Weigel, Ph.D. Universität Leipzig 1650 Gottfried Wilhelm Leibniz, Dr. jur. Universität Altdorf 1666 Johann Bernoulli, Ph.D. 1694 Leonhard Euler, Ph.D. Universität Basel 1726 Joseph Louis Lagrange, Ph.D. Simeon Denis Poisson, Ph.D. Jean-Baptiste Joseph Fourier, Ph

Matta, Abraham "Ibrahim"

133

The 0.3 mm diameter flexible amperometric lactate probe  

NASA Astrophysics Data System (ADS)

A flexible lactate electrode was made of 400 +/- 100 7 micrometers diameter carbon fibers, epoxy embedded in a 0.3 mm diameter polyimide tubing. The electrode was modified by precipitating on it the relatively insoluble complex formed between 1100 kd partially N-ethylamine quaternized poly((vinylpyridine)Os(bipyridine)2Cl)Cl (POs-EA) and lactate oxidase. The steady-state lactate electrooxidation current, at 2mM lactate concentration and at 22 C, was 4OO nA. The 5O +/- 10 microA/sq cm current density and the 2OmA/sq cm/M sensitivity decreased only by 5 percent upon increasing the partial pressure of oxygen from 0.0 to 0.2 atm. The electrode retains its sensitivity after dry storage at 4 C for 4 months in air but loses at 37 C half of its sensitivity in 7 hours through polymer desorption when operated at 0.4V (SCE).

Wang, Dan L.; Heller, Adam

1993-01-01

134

7 mm lambda VLBA Observations of Sagittarius A*  

E-print Network

We present 7 mm lambda VLBA observations of the compact nonthermal radio source in the Galactic Center, Sgr A*. These observations confirm the hypothesis that the image of Sgr A* is a resolved elliptical Gaussian caused by the scattering of an intervening thermal plasma. The measured major axis of Sgr A* is 0.76 \\pm 0.04 mas, consistent with the predicted scattering size of 0.67 \\pm 0.03. We find an axial ratio of 0.73 \\pm 0.10 and a position angle of 77.0 \\pm 7.4 deg. These results are fully consistent with VLBI observations at longer wavelengths and at 3 mm lambda. We find no evidence for any additional compact structure to a limit of 35 mJy. The underlying radio source must be smaller than 4.1 AU for a galactocentric distance of 8.5 kpc. This result is consistent with the conclusion that the radio emission from Sgr A* results from synchrotron or cyclo-synchrotron radiation of gas in the vicinity of a black hole with a mass near 10^6 M_sun.

Geoffrey C. Bower; Donald C. Backer

1998-02-03

135

Resonant biaxial 7-mm MEMS mirror for omnidirectional scanning  

NASA Astrophysics Data System (ADS)

Low-cost automotive laser scanners for environment perception are needed to enable the integration of advanced driver assistant systems (ADAS) into all automotive vehicle segments, a key to reducing the number of traffic accidents on roads. An omnidirectional 360 degree laser scanning concept has been developed based on combination of an omnidirectional lens and a biaxial large aperture MEMS mirror. This omnidirectional scanning concept is the core of a small sized low-cost time-of-flight based range sensor development. This paper describes concept, design, fabrication and first measurement results of a resonant biaxial 7mm gimbal-less MEMS mirror that is electrostatically actuated by stacked vertical comb drives. Identical frequencies of the two resonant axes are necessary to enable the required circle scanning capability. A tripod suspension was chosen since it allows minimizing the frequency splitting of the two resonant axes. Low mirror curvature is achieved by a thickness of the mirror of more than 500 ?m. Hermetic wafer level vacuum packaging of such large mirrors based on multiple wafer bonding has been developed to enable to achieve a large mechanical tilt angle of +/- 6.5 degrees in each axis. The 7mm-MEMS mirror demonstrates large angle circular scanning at 1.5kHz.

Hofmann, U.; Aikio, M.; Janes, J.; Senger, F.; Stenchly, V.; Weiss, M.; Quenzer, H.-J.; Wagner, B.; Benecke, W.

2013-03-01

136

Change in pH regimes and adventitious root induction in semi-hardwood cuttings of Gmelina arborea Roxb  

Microsoft Academic Search

Change in pH regimes (pH 5.5–8.5), IBA (0.5 mM) and their interactions significantly influenced adventitious root induction\\u000a and growth in semi-hardwood shoot cuttings collected from annually hedged Gmelina arborea Roxb. stockplants of 4 years of age and maintained in earthen pots. Acidic pH 5.5 administered for 4 h as 5.0 mM potassium\\u000a phosphate buffer significantly promoted rooting ability (%) and root number cutting?1 and

Pramod Kumar; Surendra Kumar Jharia; Shamim Akhtar Ansari

137

Coupled inductive sensors for monitoring the pH of electrolyte solutions  

Microsoft Academic Search

Variations of the coupling between two inductors in the presence of a strong electrolyte with varying pH value is investigated. Inductors were placed at a distance of 15.875 mm apart. S12 parameters were measured and used as an indicator to the strength of coupling between the two inductors. The pH of the electrolyte solution was reduced from 4.2 to 0.2,

Siavash Saremi-Yarahmadi; Kristel Fobelets; Chris Toumazou

2011-01-01

138

Effect of Applied Potentials on Environmental Cracking Behavior of 17-4 PH Stainless Steel Weldments  

Microsoft Academic Search

The effects of anodic, cathodic, and open-circuit potentials (OCP) on the environmental cracking behavior of 17% Cr-4% Ni (17-4 [UNS S17400]) precipitation-hardenable (PH) stainless steel (SS) welds subjected to different thermal treatments were studied. Sheets of 17-4 PH SS 1.5 mm thick and in solution-treated condition were full-penetration welded autogenously using the gas tungsten arc welding process (GTAW). Weldments were

K. S. Raja; K. P. Rao

1995-01-01

139

Phosphocreatine kinetics at the onset of contractions in skeletal muscle of MM creatine kinase knockout mice  

NASA Technical Reports Server (NTRS)

Phosphocreatine (PCr) depletion during isometric twitch stimulation at 5 Hz was measured by (31)P-NMR spectroscopy in gastrocnemius muscles of pentobarbital-anesthetized MM creatine kinase knockout (MMKO) vs. wild-type C57B (WT) mice. PCr depletion after 2 s of stimulation, estimated from the difference between spectra gated to times 200 ms and 140 s after 2-s bursts of contractions, was 2.2 +/- 0.6% of initial PCr in MMKO muscle vs. 9.7 +/- 1.6% in WT muscles (mean +/- SE, n = 7, P < 0.001). Initial PCr/ATP ratio and intracellular pH were not significantly different between groups, and there was no detectable change in intracellular pH or ATP in either group after 2 s. The initial difference in net PCr depletion was maintained during the first minute of continuous 5-Hz stimulation. However, there was no significant difference in the quasi-steady-state PCr level approached after 80 s (MMKO 36.1 +/- 3.5 vs. WT 35.5 +/- 4.4% of initial PCr; n = 5-6). A kinetic model of ATPase, creatine kinase, and adenylate kinase fluxes during stimulation was consistent with the observed PCr depletion in MMKO muscle after 2 s only if ADP-stimulated oxidative phosphorylation was included in the model. Taken together, the results suggest that cytoplasmic ADP more rapidly increases and oxidative phosphorylation is more rapidly activated at the onset of contractions in MMKO compared with WT muscles.

Roman, Brian B.; Meyer, Ronald A.; Wiseman, Robert W.

2002-01-01

140

PhET Simulation: Microwaves  

NSDL National Science Digital Library

This is an interactive simulation on the topic of microwave radiation. Users adjust the frequency and amplitude of microwaves in an oven-shaped cavity and watch water molecules rotate, bounce, and behave as dipoles. They can view the microwave field as a wave, a single line of vectors, or the entire field. This item is part of a larger and growing collection by the Physics Education Technology Project (PhET). Each PhET resource was developed using principles from physics education research. SEE RELATED MATERIALS BELOW for an activity designed by the PhET team specifically for use with the Microwaves simulation.

2008-10-30

141

Modelling and performance of Nb SIS mixers in the 1.3 mm and 0.8 mm bands  

NASA Technical Reports Server (NTRS)

We describe the modeling and subsequent improvements of SIS waveguide mixers for the 200-270 and 330-370 GHz bands (Blundell, Carter, and Gundlach 1988, Carter et al 1991). These mixers are constructed for use in receivers on IRAM radiotelescopes on Pico Veleta (Spain, Sierra Nevada) and Plateau de Bure (French Alps), and must meet specific requirements. The standard reduced height waveguide structure with suspended stripline is first analyzed and a model is validated through comparison with scale model and working scale measurements. In the first step, the intrinsic limitations of the standard mixer structure are identified, and the parameters are optimized bearing in mind the radioastronomical applications. In the second step, inductive tuning of the junctions is introduced and optimized for minimum noise and maximum bandwidth. In the 1.3 mm band, a DSB receiver temperature of less than 110 K (minimum 80 K) is measured from 180 through 260 GHz. In the 0.8 mm band, a DSB receiver temperature of less than 250 K (minimum 175 K) is obtained between 325 and 355 GHz. All these results are obtained with room-temperature optics and a 4 GHz IF chain having a 500 MHz bandwidth and a noise temperature of 14 K.

Karpov, A.; Carter, M.; Lazareff, B.; Billon-Pierron, D.; Gundlach, K. H.

1992-01-01

142

A densitometric analysis of commercial 35mm films  

NASA Technical Reports Server (NTRS)

IIaO films have been subjected to various sensitometric tests. The have included thermal and aging effects and reciprocity failure studies. In order to compare the special IIaO film with popular brands of 35 mm films and their possible use in astrophotography, Agfa, Fuji and Kodak print and slide formats, as well as black and white and color formats, were subjected to sensitometric, as well as densitometric analysis. A scanning electron microscope was used to analyze grain structure size, and shape as a function of both speed and brand. Preliminary analysis of the grain structure using an ISI-SS40 scanning electron microscope indicates that the grain sizes for darker densities are much larger than the grain size for lighter densities. Researchers analyze the scanning electron microscope findings of the various grains versus densities as well as enhancement of the grains, using the IP-8500 Digital Image Processor.

Hammond, Ernest C., Jr.; Ruffin, Christopher, III

1989-01-01

143

120-mm supercondcting quadrupole for interaction regions of hadron colliders  

SciTech Connect

Magnetic and mechanical designs of a Nb{sub 3}Sn quadrupole magnet with 120-mm aperture suitable for interaction regions of hadron colliders are presented. The magnet is based on a two-layer shell-type coil and a cold iron yoke. Special spacers made of a low-Z material are implemented in the coil mid-planes to reduce the level of radiation heat deposition and radiation dose in the coil. The quadrupole mechanical structure is based on aluminum collars supported by an iron yoke and a stainless steel skin. Magnet parameters including maximum field gradient and field harmonics, Nb3Sn coil pre-stress and protection at the operating temperatures of 4.5 and 1.9 K are reported. The level and distribution of radiation heat deposition in the coil and other magnet components are discussed.

Zlobin, A.V.; Kashikhin, V.V.; Mokhov, N.V.; Novitski, I.; /Fermilab

2010-05-01

144

beta Pictoris with ALMA: mm grains and molecular gas  

NASA Astrophysics Data System (ADS)

The beta Pictoris debris disk was observed with ALMA in Cycle 0 & 1, resulting in images of the submm continuum and CO gas at a resolution of ˜10AU. We describe the results, which show that the mm grains and CO lies mostly in a belt at radii from 50-160AU. The CO is highly asymmetrical, arising from one or two compact clumps at 85AU radius, along with 'tails' of fainter emission. The bright CO peak is co-located with a clump seen in the mid-infrared, and CO line ratios allow the excitation temperature to be estimated. We discuss possible origins for this gas, comparing it with primordial gas and secondary gas from comet collisions, and how it relates to the atomic gas seen in the system.

Dent, B.

2014-09-01

145

Reaction mechanism of monoamine oxidase from QM/MM calculations.  

PubMed

The flavoenzyme monoamine oxidase (MAO) is essential for the enzymatic decomposition of neurotransmitters. While it is commonly accepted that the rate limiting step of the reaction is the stereoselective abstraction of a hydrogen from the substrate, the precise mechanism is unknown. We modeled the reaction of human MAO-B with benzylamine by means of QM/MM calculations based on density functional theory. Oxidation of the unprotonated substrate was found to proceed with rates in good agreement with experimental values, while the protonated substrate does not react at room temperature. Our results support a concerted asynchronous polar nucleophilic mechanism. The lone pair of the amine-nitrogen interacts with a carbon atom of the flavin cofactor. During the reaction, this lone pair, as well as a proton, are transferred to the cofactor. Analysis of the electronic structure during the reaction rules out a radical mechanism. PMID:24164690

Abad, Enrique; Zenn, Roland K; Kästner, Johannes

2013-11-21

146

Supersonic Love waves in strong piezoelectrics of symmetry mm2  

SciTech Connect

A study has been made of the Love wave propagation on piezoelectric substrates of symmetry mm2. It has been shown that under certain conditions the velocity of the Love wave exceeds that of shear horizontal (SH) bulk waves in the substrate. This occurs when the slowness curve of SH bulk waves in the substrate either has a concavity or is convex with nearly zero curvature. For such {open_quotes}supersonic{close_quotes} Love waves to appear, it is also required that the substrate as well as the layer be specially oriented and that their material constants fulfill a number of inequalities. Numerical computations have been carried out for a number of structures. The results of numerical computations have been compared with approximate analytical estimations. {copyright} 2001 American Institute of Physics.

Darinskii, A. N.; Weihnacht, M.

2001-07-01

147

Characterisation of mechanically milled 17-4 PH gas atomized stainless steel powders  

Microsoft Academic Search

A laboratory scale Szegvari type vertical mechanical alloying (MA)\\/mechanical milling (MM) attritor for research purposes was designed and constructed at Gazi University. By using this attritor, optimum processing parameters such as milling time, milling speed (rev\\/min), diameter and the amount of milling balls, milling atmosphere were determined when MM’ing of gas atomized 17-4PH stainless steel powders were carried out. After

Cemil Çetinkaya; Tayfun F?nd?k; Sedat Özbilen

2007-01-01

148

300mm pilot line DSA contact hole process stability  

NASA Astrophysics Data System (ADS)

Directed Self-Assembly (DSA) is today a credible alternative lithographic technology for semiconductor industry [1]. In the coming years, DSA integration could be a standard complementary step with other lithographic techniques (193nm immersion, e-beam, extreme ultraviolet). Its main advantages are a high pattern resolution (down to 10nm), a capability to decrease an initial pattern edge roughness [2], an absorption of pattern guide size variation, no requirement of a high-resolution mask and can use standard fab-equipment (tracks and etch tools). The potential of DSA must next be confirmed viable for high volume manufacturing. Developments are necessary to transfer this technology on 300mm wafers in order to demonstrate semiconductor fab-compatibility [3-7]. The challenges concern especially the stability, both uniformity and defectivity, of the entire process, including tools and Blok Co-Polymer (BCP) materials. To investigate the DSA process stability, a 300mm pilot line with DSA dedicated track (SOKUDO DUO) is used at CEALeti. BCP morphologies with PMMA cylinders in a PS matrix are investigated (about 35nm natural period). BCP selfassembly in unpatterned surface and patterned surface (graphoepitaxy) configurations are considered in this study. Unpatterned configuration will initially be used for process optimization and fix a process of record. Secondly, this process of record will be monitored with a follow-up in order to validate its stability. Steps optimization will be applied to patterned surface configurations (graphoepitaxy) for contact hole patterning application. A process window of contact hole shrink process will be defined. Process stability (CD uniformity and defectivity related to BCP lithography) will be investigated.

Argoud, M.; Servin, I.; Gharbi, A.; Pimenta Barros, P.; Jullian, K.; Sanche, M.; Chamiot-Maitral, G.; Barnola, S.; Tiron, R.; Navarro, C.; Chevalier, X.; Nicolet, C.; Fleury, G.; Hadziioannou, G.; Asai, M.; Pieczulewski, C.

2014-03-01

149

David Cheresh, PhD  

Cancer.gov

Meetings & Events Home Agenda Speaker Biosketches Abstracts Logistics Contact Speaker Biosketches David Cheresh, PhD(University of California, San Diego) Dr. David Cheresh studies the mechanism of action of signaling networks that regulate

150

Philip Prorok, PhD  

Cancer.gov

Philip Prorok, PhD, mirum est notare quam littera gothica, quam nunc putamus parum claram, anteposuerit litterarum formas humanitatis per seacula quarta decima et quinta decima. Eodem modo typi, qui nunc nobis videntur parum clari, fiant sollemnes in futurum.

151

Establishment of Cell Lines from Both Myeloma Bone Marrow and Plasmacytoma: SNU_MM1393_BM and SNU_MM1393_SC from a Single Patient  

PubMed Central

Purpose. We tried to establish clinically relevant human myeloma cell lines that can contribute to the understanding of multiple myeloma (MM). Materials and Methods. Mononuclear cells obtained from MM patient's bone marrow were injected via tail vein in an NRG/SCID mouse. Fourteen weeks after the injection, tumor developed at subcutis of the mouse. The engraftment of MM cells into mouse bone marrow (BM) was also observed. We separated and cultured cells from subcutis and BM. Results. After the separation and culture of cells from subcutis and BM, we established two cell lines originating from a single patient (SNU_MM1393_BM and SNU_MM1393_SC). Karyotype of the two newly established MM cell lines showed tetraploidy which is different from the karyotype of the patient (diploidy) indicating clonal evolution. In contrast to SNU_MM1393_BM, cell proliferation of SNU_MM1393_SC was IL-6 independent. SNU_MM1393_BM and SNU_MM1393_SC showed high degree of resistance against bortezomib compared to U266 cell line. SNU_MM1393_BM had the greater lethality compared to SNU_MM1393_SC. Conclusion. Two cell lines harboring different site tropisms established from a single patient showed differences in cytokine response and lethality. Our newly established cell lines could be used as a tool to understand the biology of multiple myeloma. PMID:25343143

Jung, Woo-June; Ahn, Kwang-Sung; Yoon, Sung-Soo

2014-01-01

152

A QM/MM study of the catalytic mechanism of aspartate ammonia lyase.  

PubMed

Aspartate ammonia lyase (Asp) is one of three types of ammonia lyases specific for aspartate or its derivatives as substrates, which catalyzes the reversible reaction of l-aspartate to yield fumarate and ammonia. In this paper, the catalytic mechanism of Asp has been studied by using combined quantum-mechanical/molecular-mechanical (QM/MM) approach. The calculation results indicate that the overall reaction only contains two elementary steps. The first step is the abstraction of C? proton of l-aspartate by Ser318, which is calculated to be rate limiting. The second step is the cleavage of C?N bond of l-aspartate to form fumarate and ammonia. Ser318 functions as the catalytic base, whereas His188 is a dispensable residue, but its protonation state can influence the active site structure and the existing form of leaving amino group, thereby influences the activity of the enzyme, which can well explain the pH dependence of enzymatic activity. Mutation of His188 to Ala only changes the active site structure and slightly elongates the distance of C? proton of substrate with Ser318, causing the enzyme to remain significant but reduced activity. PMID:24875395

Zhang, Jing; Liu, Yongjun

2014-06-01

153

Effects of PCO2, pH and extracellular calcium on contraction of airway smooth muscle from rats.  

PubMed

The effect of changes in PCO2 on airway smooth muscle was studied in acetylcholine-induced contractions of isolated rat trachea. Elevation of superfusate PCO2 from control PCO2, 38 mm Hg (pH 7.49), to 168 mm Hg (pH 6.74) decreased tension to 68% of control tension; reduction of PCO2 to 19 mm Hg (pH 7.84) increased tension to 104%. Similar effects on tension occurred when pH was altered by varying superfusate bicarbonate concentration at constant PCO2. Modification of the response to changes in PCO2 by varying extracellular calcium (Ca2+) concentration and also by verapamil indicated that changes in PCO2 and pH may alter Ca2+ uptake by the smooth muscle. Calcium uptake was measured by 45Ca2+ and the lanthanum method. At control pH 7.49, net Ca2+ uptake was 5.34 mmol Ca2+/kg trachea 60 min after the onset of contraction; this decreased to 4.26 at pH 6.88, and increased to 6.58 at pH 7.85. The results suggest that the mechanism whereby changes in PCO2 affect airway smooth muscle contraction is a pH-dependent alteration of Ca2+ uptake. PMID:3099356

Twort, C H; Cameron, I R

1986-12-01

154

ALMA reveals VYCMa's sub-mm maser and dust distribution  

E-print Network

Cool, evolved stars have copious, enriched winds. The structure of these winds and the way they are accelerated is not well known. We need to improve our understanding by studying the dynamics from the pulsating stellar surface to about 10 stellar radii, where radiation pressure on dust is fully effective. Some red supergiants have highly asymmetric nebulae, implicating additional forces. We retrieved ALMA Science Verification data providing images of sub-mm line and continuum emission from VY CMa. This enables us to locate water masers with milli-arcsec precision and resolve the dusty continuum. The 658-, 321- and 325-GHz masers lie in irregular, thick shells at increasing distances from the centre of expansion. For the first time this is confirmed as the stellar position, coinciding with a compact peak offset to the NW of the brightest continuum emission. The maser shells (and dust formation zone) overlap but avoid each other on tens-au scales. Their distribution is broadly consistent with excitation models...

Richards, A M S; Humphreys, E M; Vlahakis, C; Vlemmings, W; Baudry, A; De Beck, E; Decin, L; Etoka, S; Gray, M D; Harper, G M; Hunter, T R; Kervella, P; Kerschbaum, F; McDonald, I; Melnick, G; Muller, S; Neufeld, D; O'Gorman, E; Parfenov, S Yu; Peck, A B; Shinnaga, H; Sobolev, A M; Testi, L; Uscanga, L; Wootten, A; Yates, J A; Zijlstra, A

2014-01-01

155

Digital Frequency Domain Multiplexer for mm-Wavelength Telescopes  

SciTech Connect

An FPGA based digital signal processing (DSP) system for biasing and reading out multiplexed bolometric detectors for mm-wavelength telescopes is presented. This readout system is being deployed for balloon-borne and ground based cosmology experiments with the primary goal of measuring the signature of inflation with the Cosmic Microwave Background Radiation. The system consists of analog superconducting electronics running at 250 mK and 4 K, coupled to digital room temperature backend electronics described here. The digital electronics perform the real time functionality with DSP algorithms implemented in firmware. A soft embedded processor provides all of the slow housekeeping control and communications. Each board in the system synthesizes multi-frequency combs of 8 to 32 carriers in the MHz band to bias the detectors. After the carriers have been modulated with the sky-signal by the detectors, the same boards digitize the comb directly. The carriers are mixed down to base-band and low pass filtered. The signal bandwidth of 0.050Hz-100 Hz places extreme requirements on stability and requires powerful filtering techniques to recover the sky-signal from the MHz carriers.

Spieler, Helmuth G; Dobbs, Matt; Bissonnette, Eric; Spieler, Helmuth G.

2007-07-23

156

Pressure-driven wave propagation in mm-scale channels  

NASA Astrophysics Data System (ADS)

Miniaturized analysis systems, which may potentially revolutionize detection of air-borne biological or chemical agents through increased portability and real time response, also present exciting fundamental challenges. Development of integrated total analysis systems will depend on optimizing the interaction of multiple components such as valves, injectors, pumps, and channels. In pressure-driven systems, such components may produce finite amplitude waves and wave attenuation may then be a key design factor in optimizing both devices that operate on steady-state assumptions and devices where unsteadiness is cultivated, for example mixers. A fundamental experimental investigation of wave propagation as a function of the channel size was performed. A shock wave is transmitted into mm-scale channels to achieve a well-characterized initial condition. Wave attenuation and structure information is obtained from time-of-arrival data and pressure histories along the channel. Experimental results are compared with models developed for the analogous flow regime of wave propagation through macroscale channels in low pressure environments.

Austin, Joanna

2005-11-01

157

Effects of temperature, pressure, and pH on the solubility of triclinic lysozyme crystals  

NASA Astrophysics Data System (ADS)

We measured the temperature dependence of the solubility, Ce, of triclinic lysozyme crystals on temperature at two pressures (0.1 and 100 MPa) and five pHs (4.3, 4.4, 4.5, 4.6, and 4.7) by in situ observation of the morphological changes in the crystals. The solubility increased with increase in temperature and pressure. The enthalpies of dissolution (?H) decreased with increase in pressure when we used the same 50 mM sodium acetate buffer solution (pH=4.5 at 0.1 MPa). The effects of pH on solubility were somehow complicated. Although the solubilities at pH 4.7 did not differ from those at pH 4.5, those at pH 4.3 were significantly larger than those at pH 4.5. Since the pH of an acetate buffer is known to decrease from 4.71 to 4.52 at 98.1 MPa and 25 °C [22], the pH of the acetate buffer (pH 4.5 at 0.1 MPa) decreased to pH?4.3 as pressure increased to 100 MPa. Thus, from the viewpoint of “constant pH”, ?H increased with increase in pressure, since ?H at pH 4.3 and 0.1 MPa was smaller than that at 100 MPa. This inconsistency is probably due to the change in the hydration state of the crystal and solution with decreasing pH (from 4.5 to 4.3).

Suzuki, Yoshihisa; Konda, Emi; Hondoh, Hironori; Tamura, Katsuhiro

2011-03-01

158

The Effect of pH on the Antimicrobial Efficiency of Silver Alginate on Chronic Wound Isolates  

PubMed Central

Background Nonhealing and stalled chronic wounds are often reported to reside within an alkaline environment. Consequently, a number of researchers have proposed that lowering the pH of a chronic wound environment will enable healing to progress. However, it is not known whether the efficacies of silver-impregnated wound dressings are affected by pH. Objective To investigate whether pH has an effect on the antimicrobial barrier efficacy of a silver alginate wound dressing on wound isolates. Methods Twenty-five bacteria and yeasts that had been routinely isolated from chronic wounds were separately exposed to a silver alginate wound dressing with the use of a standardized corrected zone of inhibition (CZOI) assay. Results The silver alginate dressing demonstrated a broad spectrum of antimicrobial barrier activity within the dressing against all wound isolates. However, at a pH of 5.5, compared with a pH of 7, the antimicrobial barrier activity of the silver alginate dressing significantly increased. For all yeasts the CZOI ranged from 6.25 to 11 mm at a pH of 7. At a pH of 5.5, the CZOI range increased from 8.5 to 12.25 mm. For the Gram-negative isolates, the CZOI ranged from 0.75 to 6.5 mm at a pH 7, compared with a CZOI range of 2.75 to 8 mm at pH 5.5. The CZOI for the Gram-positive isolates, including meticillin-resistant Staphylococcus aureus, ranged from 3 to 7.75 mm at pH 7 and from 4.5 to 11.75 mm at pH 5.5. Conclusion For all isolates tested, excluding one strain of Candida albicans and one vancomycin-resistant Enterococcus strain, lowering pH to 5.5 resulted in an improvement in the antimicrobial barrier activity within the silver alginate dressing. Based on these initial in vitro findings, it is possible to suggest that there may be benefits to maintaining an infected or recalcitrant wound in a slightly acid (pH 5.5) environment. In particular, doing so may lead to an enhanced antimicrobial barrier effect of silver, a quicker reduction in the wound microbial bioburden, and therefore a reduction in the need for prolonged antimicrobial use. However, more in vitro and in vivo studies would be warranted to further substantiate these claims. PMID:24527156

Slone, Will; Linton, Sara; Okel, Tyler; Corum, Linda; Thomas, John G.; Percival, Steven L.

2011-01-01

159

Design of the multilayer insulation system for the Superconducting Super Collider 50mm dipole cryostat  

Microsoft Academic Search

The development of the multilayer insulation (MLI) system for the Superconducting Super Collider (SSC) 50 mm collider dipole cryostat is an ongoing extension of work conducted during the 40 mm cryostat program. While the basic design of the MLI system for the 50 mm cryostat resembles that of the 40 mm cryostat, results from measurements of MLI thermal performance below

W. N. Boroski; T. H. Nicol; C. J. Schoo

1991-01-01

160

Analytical performance during ratiometric long-term imaging of pH in bioturbated sediments.  

PubMed

In this study, the long-term analytical performance of a high-resolution ratiometric imaging sensor for pH was quantitatively determined. The sensor was applied in an experimental microcosm to illustrate biogeochemical consequences from mining activities by the chemosymbiotic bivalve Thyasira sarsi. Utilizing time-correlated pixel-by-pixel calibration protocols during imaging, close to 90% of the pixels were associated with a precision (S.D.) of <0.05 pH units at the end of an experimental period of 17 days. For comparison, a precision of <0.05 pH units was achieved for less than 50% of the pixels throughout experiments using conventional pre-sample calibration procedures. The average standard deviation of pixels was 0.01 pH units. Image analysis of single pixel derivatives and pH measurements over time suggested that T. sarsi affect pH distributions and general sediment geochemistry more than would be expected based on the small size of the bivalves. A significant decrease of pH in the overlying water suggested a considerable release of reduced compounds from the exhalent stream of the thyasirids. Strong pH gradients were demonstrated not only across the sediment-water interface but, also associated with bioturbation activities immediately adjacent to T. sarsi burrowing tracts, inhalant tubes and pedal tracts in the sediment matrix. Gradients of up to 1.16 pH units per mm were observed. PMID:20441913

Hakonen, Aron; Hulth, Stefan; Dufour, Suzanne

2010-06-15

161

Sub-mm CO Measurements of the Orion Molecular Cloud  

NASA Astrophysics Data System (ADS)

Images of a >3' region around the Orion KL source have been made in the J=4-3 (461 GHz) and J=7-6 (806 GHz) lines of CO with angular resolutions of 18'' and 13'', using the 10-meter Heinrich Hertz Telescope (HHT) of the Sub-Millimeter Telescope Observatory (SMTO). This region contains a variety of objects: (1) the Hot Core (a region containing complex molecules) and Orion KL outflow (NE of the center of the 10'' diameter Hot Core, and very likely associated with the continuum source `I' (Menten & Reid 1995 ApJ 445, L157)), (2) another outflow source, Orion-S ( ~100'' south of the Hot Core (Rodriguez-Franco et al. 1999 A&A 344, L57)), (3) the ionized-neutral interface at the rear of the Orion HII region, and (4) the Orion Bar feature (an ionized-neutral interface to the SW of the HII region). Regions (3) and (4) are examples of `Photon Dominated Regions' or `PDR's'. The sub-mm CO lines are emitted from warm gas; the J=7-6 line is emitted from an energy level 156 Kelvin above the ground state. The excellent pointing and low sidelobes of the HHT allow accurate comparisons with high r! esolution CO images in lower J lines and images of other species. Our J=7-6 CO image was made with the Harvard-Smithsonian Center for Astrophysics Hot Electron Bolometer (Kawamura et al. 1999 IEEE Trans. on Appl. Superconductivity 9, 3753. The HHT is operated by the Submillimeter Telescope Observatory on behalf of the Max-Planck-Institut f. Radioastronomie and Steward Observatory of The University of Arizona. We thank the CfA receiver group for providing the Hot Electron Bolometer used to take the J=7-6 CO line data.

Wilson, T. L.; Muders, D.; Kramer, C.; Henkel, C.

2000-05-01

162

Development of in situ CO2 and pH sensor for AUVs and ROVs  

NASA Astrophysics Data System (ADS)

Japan Agency for Marine-Earth Science and Technology (JAMSTEC) has been developing two-type autonomous underwater vehicles (AUVs): a cruising AUV and a working AUV, since October 2010. These vehicles will perform carbon dioxide (CO2) and pH observations to explore hydrothermal plume on seabed mineral resources and to monitor a leak of CO2 in carbon capture and storage (CCS) up to depth of 3,000 meters. We here have been developing the compact in situ CO2 and pH sensor (Hybrid CO2-pH sensor: HCS) for the AUVs to obtain vertical and horizontal distributions of CO2 and pH. The HCS consists of an aluminum pressure housing (diameter 84 mm, length 570 mm, weight 4 kg) and an acrylic silicon-oil filled, pressure-compensated vessel (diameter 90 mm, length 355 mm, weight 2 kg) containing valves and pump unit. The HCS is also useful for the observation by remotely operated vehicles (ROVs). The measured data were transmitted to the AUVs or ROVs by serial communications. We can monitor the data of in situ pCO2, pH and so on in real time on board. The measurement principle for the CO2 sensor is based on spectrophotometry. The pCO2 is calculated from the optical absorbance of the pH indicator solution equilibrated with CO2 in seawater through a gas permeable membrane. On the other hand, we adopt potentiometric analysis using original glass and reference electrodes as a pH sensor because of the most commonly used technique for sea water pH measurements and high-speed response (within 20 seconds). From simultaneously measured data of in situ pCO2 and pH, we can also calculate dissolved inorganic carbon (DIC) and total alkalinity (TA) as other carbonate species in the ocean. The resolutions of HCS are 1 ?atm for pCO2 and 0.001 pH. In the laboratory experiment, the HCS obtained precisions within 3 ?atm and within 0.01 pH, respectively. Our first in situ observational test of the HSC with cruising AUV was made in the coast of the Japan Sea last August. And also first in situ test of the HCS with ROV was performed at Okinawa Trough last September. The data obtained from each tests are consistent with predictions based on past studies.

Nakano, Yoshiyuki; Kimoto, Hideshi; Miwa, Tetsuya; Yoshida, Hiroshi

2013-04-01

163

Miniature Chemical Optical Fiber Sensors For Ph Measurements  

NASA Astrophysics Data System (ADS)

A miniature optode (diameter about 1 mm) was built with 200/280 all-silica fibers usable over long distances. The immobilized indicator is fixed on a cross-linked styrene/divinyl-benzene copolymer (XADZI). The sensors are constructed so that measurements can be taken either by absorption at many different points in the single optical fiber, or by reflection from the end of the fiber. A wide range of pH values are encountered with radioactive wastes, and experiments are performed either with bromophenol blue (3.0 to 6.0) or a double-indicator (thymol blue) between 0.8 and 3.2, and 9 and 13 pH, as well as other indicators. Lifetimes, reversibility and kinetics are considered. A new low-cost device is proposed for chemical process control and medical applications.

Boisde, G.; Perez, J. J.

1987-10-01

164

PhET: Masses & Springs  

NSDL National Science Digital Library

This simulation provides a realistic virtual mass-and-spring laboratory. Users can explore spring motion by manipulating stiffness of the spring and mass of the hanging weight. Concepts of Hooke's Law and elastic potential energy are further clarified through charts showing kinetic, potential, and thermal energy for each spring. This item is part of a larger collection of simulations developed by the Physics Education Technology project (PhET). The simulations are animated, interactive, and game-like environments in which students learn through exploration. All of the sims are freely available from the PhET website for incorporation into classes.

2008-07-29

165

Radka Stoyanova, PhD  

Cancer.gov

Dr. Radka Stoyanova, PhD has extensive background in developing approaches to best utilize imaging techniques in cancer research, diagnosis and treatment, as well as in developing approaches for the analysis, mining, and interpretation of "big data" generated by high-throughput approaches such as genomics, proteomics, and metabolomics. She received her Masters Degree in Mathematics from the University of Sofia, Bulgaria. Dr. Stoyanova obtained her doctoral training and PhD degree at the Imperial College London, under the mentorship of Profs.

166

pH Meter Calibration  

NSDL National Science Digital Library

The North Carolina Community College System BioNetwork's interactive eLearning tools (IETs) are reusable chunks of training that can be deployed in a variety of courses or training programs. IETs are designed to enhance, not replace hands-on training. Learners are able to enter a hands-on lab experience better prepared and more confident. This particular IET delves into pH Meter Calibration, where visitors practice performing a three point calibration of a pH meter using buffer solutions.

167

The Termite Gut Microflora as an Oxygen Sink: Microelectrode Determination of Oxygen and pH Gradients in Guts of Lower and Higher Termites  

Microsoft Academic Search

Clark-type oxygen microelectrodes and glass pH microelectrodes, each with a tip diameter of <10 mm, were used to obtain high-resolution profiles of oxygen concentrations and pH values in isolated termite guts. Radial oxygen profiles showed that oxygen penetrated into the peripheral hindgut contents up to about 150 to 200 mm below the epithelial surface in both the lower termite Reticulitermes

ANDREAS BRUNE; DAVID EMERSON; ANDJOHN A. BREZNAK

1995-01-01

168

Dosimetric study of the 15 mm ROPES eye plaque  

SciTech Connect

The main aim of this paper is to make a study of dose-rate distributions obtained around the 15 mm, radiation oncology physics and engineering services, Australia (ROPES) eye plaque loaded with {sup 125}I model 6711 radioactive seeds. In this study, we have carried out a comparison of the dose-rate distributions obtained by the algorithm used by the Plaque Simulator (PS) (BEBIG GmbH, Berlin, Germany) treatment planning system with those obtained by means of the Monte Carlo method for the ROPES eye plaque. A simple method to obtain the dose-rate distributions in a treatment planning system via the superposition of the dose-rate distributions of a seed placed in the eye plaque has been developed. The method uses eye plaque located in a simplified geometry of the head anatomy and distributions obtained by means of the Monte Carlo code GEANT4. The favorable results obtained in the development of this method suggest that it could be implemented on a treatment planning system to improve dose-rate calculations. We have also found that the dose-rate falls sharply along the eye and that outside the eye the dose-rate is very low. Furthermore, the lack of backscatter photons from the air located outside the eye-head phantom produces a dose reduction negligible for distances from the eye-plaque r<1 cm but reaches up to 20% near the air-eye interface. Results showed that the treatment planning system lacks accuracy around the border of the eye (in the sclera and the surrounding area) due to the simplicity of the algorithm used. The BEBIG treatment planning system uses a global attenuation factor that takes into account the effect of the eye plaque seed carrier and the lack of backscatter photons caused by the metallic cover, which in the case of a ROPES eye plaque has a default value of T=1 (no correction). In the present study, a global attenuation factor T=0.96 and an air-interface correction factor which improve on treatment planning system calculations were obtained.

Granero, D.; Perez-Calatayud, J.; Ballester, F.; Casal, E.; Frutos, J.M. de [Department of Atomic, Molecular and Nuclear Physics and IFIC, University of Valencia-CSIC, Dr. Moliner 50, E46100 Burjassot (Spain); Medical Physics Section, University Hospital, Av. Ramon y Cajal 3, E47011 Valladolid (Spain)

2004-12-01

169

. , ..., PhD / : 30 1977,  

E-print Network

; . , ..., PhD 2010 2 BOOK CHAPTER (in press) Invited Book Chapter for the Book: "Modelling of Masonry and Damage Analysis in Masonry Arches, Vietnam Journal of Mechanics, 31(3-4) (2009) 185-190 Betti M of Failure of Masonry Arches, Comptes Rendus Mecanique, 336 (2008), 42-53 Drosopoulos G.A., Stavroulakis G

Stavroulakis, Georgios E.

170

Sashwati Roy, PhD  

Cancer.gov

Dr. Sashwati Roy is an Associate Professor of Surgery and Director of the Laser Capture Molecular Core at The Ohio State University, Columbus, Ohio. In 1994 she received her PhD degree in Physiology and Environmental Sciences and later completed her postdoctoral training at the University of California, Berkeley. Dr.

171

The influence of calcium and pH on growth in primary roots of Zea mays  

NASA Technical Reports Server (NTRS)

We investigated the interaction of Ca2+ and pH on root elongation in Zea mays L. cv. B73 x Missouri 17 and cv. Merit. Seedlings were raised to contain high levels of Ca2+ (HC, imbibed and raised in 10 mM CaCl2) or low levels of Ca2+ (LC, imbibed and raised in distilled water). In HC roots, lowering the pH (5 mM MES/Tris) from 6.5 to 4.5 resulted in strong, long-lasting growth promotion. Surprisingly, increasing the pH from 6.5 to 8.5 also resulted in strong growth promotion. In LC roots acidification of the medium (pH 6.5 to 4.5) resulted in transient growth stimulation followed by a gradual decline in the growth rate toward zero. Exposure of LC roots to high pH (pH shift from 6.5 to 8.5) also promoted growth. Addition of EGTA resulted in strong growth promotion in both LC and HC roots. The ability of EGTA to stimulate growth appeared not to be related to H+ release from EGTA upon Ca2+ chelation since, 1) LC roots showed a strong and prolonged response to EGTA, but only a transient response to acid pH, and 2) promotion of growth by EGTA was observed in strongly buffered solutions. We also examined the pH dependence of the release of 45Ca2+ from roots of 3-day-old seedlings grown from grains imbibed in 45Ca2+. Release of 45Ca2+ from the root into agar blocks placed on the root surface was greater the more acidic the pH of the blocks. The results indicate that Ca2+ may be necessary for the acid growth response in roots.

Hasenstein, K. H.; Evans, M. L.

1988-01-01

172

Comparison of Surgically-induced Astigmatism after Combined Phacoemulsification and 23-Gauge Vitrectomy: 2.2-mm vs. 2.75-mm Cataract Surgery  

PubMed Central

Purpose The 2.2-mm microincision cataract surgery and small-gauge vitrectomy system is known to result in less surgically-induced astigmatism (SIA) in comparison to conventional surgical methods. We compared the amounts of SIA after combined phacoemulsification and 23-gauge transconjunctival sutureless vitrectomy (23G-TSV) using the 2.2-mm microincision and 2.75-mm standard incision methods. Methods We studied 59 patients (61 eyes) who underwent combined phacoemulsification and 23G-TSV from November 2008 to September 2012. Twenty-eight patients (28 eyes) underwent 2.2-mm microincision coaxial phacoemulsification, and 31 patients (33 eyes) underwent 2.75-mm standard incision phacoemulsification. SIA was evaluated using Naeser's polar method with the simulated keratometric values obtained from corneal topography. Preoperative and 1-week and 1-month postoperative KP (Naeser's polar value along the specific axis) and ?KP values were compared between the 2.2-mm microincision and 2.75-mm standard incision groups. Results One week after surgery, both groups exhibited similar amounts of SIA (-?KP[120], 0.40 ± 0.41 vs. 0.51 ± 0.56 diopters [D]; p = 0.390). One month after surgery, however, the amount of SIA was significantly smaller in the 2.2-mm microincision group as compared to the 2.75-mm standard incision group (-?KP[120], 0.31 ± 0.54 vs. 0.56 ± 0.42 D; p = 0.045). Conclusions In combined phacoemulsification with 23G-TSV, 2.2-mm microincision coaxial phacoemulsification induces less SIA than does 2.75-mm standard coaxial phacoemulsification. PMID:24688255

Kim, Yong-Kyu; Kim, Yong Woo; Park, Kyu Hyung

2014-01-01

173

Effects of amiloride on thermosensitivity of Chinese hamster cells under neutral and acidic pH  

SciTech Connect

The modifying effects of amiloride on the thermosensitivity of Chinese hamster V-79 cells were examined under both neutral (pH 7.3) and acidic (pH 6.6) conditions. Amiloride, a diuretic drug, is known to inhibit the Na+/H+ exchange activity. Under the extracellular pH of 7.3, amiloride (0.1-0.5 mM) enhanced the thermal cell killing powers of 42/sup 0/C hyperthermia with increasing concentration and exposure time of the drug. The age response of cells to 42/sup 0/C hyperthermia in the presence or absence of amiloride (0.5 mM) showed that amiloride sensitized cells to heat, especially those at G1-S boundary through middle S phases. On the other hand, the lowering of extracellular pH to 6.6 enhanced cell killing by 42/sup 0/C hyperthermia. When cells were exposed to 42/sup 0/C hyperthermia in the presence of amiloride at pH 6.6, cell survival decreased still more. The thermosensitizing effects of the lowered pH at 6.6 and amiloride appeared to be additive. From these results, it is suggested that the thermosensitization by amiloride is probably due, in part, to the inhibition of cellular Na+/H+ exchange activity. The present study proposes the possibility that amiloride may be useful as a hyperthermic sensitizer in a clinical treatment of cancer.

Miyakoshi, J.; Oda, W.; Hirata, M.; Fukuhori, N.; Inagaki, C.

1986-04-01

174

Stabilization of pH in solid-matrix hydroponic systems  

NASA Technical Reports Server (NTRS)

2-[N-morpholino]ethanesulfonic acid (MES) buffer or Amberlite DP-1 (cation-exchange resin beads) were used to stabilize substrate pH of passive-wicking, solid-matrix hydroponic systems in which small canopies of Brassica napus L. (CrGC 5-2, genome : ACaacc) were grown to maturity. Two concentrations of MES (5 or 10 mM) were included in Hoagland 1 nutrient solution. Alternatively, resin beads were incorporated into the 2 vermiculite : 1 perlite (v/v) growth medium at 6% or 12% of total substrate volume. Both strategies stabilized pH without toxic side effects on plants. Average seed yield rates for all four pH stabilization treatments (13.3 to 16.9 g m-2 day-1) were about double that of the control (8.2 g m-2 day-1), for which there was no attempt to buffer substrate pH. Both the highest canopy seed yield rate (16.9 g m-2 day-1) and the highest shoot harvest index (19.5%) occurred with the 6% resin bead treatment, even though the 10 mM MES and 12% bead treatments maintained pH within the narrowest limits. The pH stabilization methods tested did not significantly affect seed oil and protein contents.

Frick, J.; Mitchell, C. A.

1993-01-01

175

Stabilization of pH in solid-matrix hydroponic systems.  

PubMed

2-[N-morpholino]ethanesulfonic acid (MES) buffer or Amberlite DP-1 (cation-exchange resin beads) were used to stabilize substrate pH of passive-wicking, solid-matrix hydroponic systems in which small canopies of Brassica napus L. (CrGC 5-2, genome : ACaacc) were grown to maturity. Two concentrations of MES (5 or 10 mM) were included in Hoagland 1 nutrient solution. Alternatively, resin beads were incorporated into the 2 vermiculite : 1 perlite (v/v) growth medium at 6% or 12% of total substrate volume. Both strategies stabilized pH without toxic side effects on plants. Average seed yield rates for all four pH stabilization treatments (13.3 to 16.9 g m-2 day-1) were about double that of the control (8.2 g m-2 day-1), for which there was no attempt to buffer substrate pH. Both the highest canopy seed yield rate (16.9 g m-2 day-1) and the highest shoot harvest index (19.5%) occurred with the 6% resin bead treatment, even though the 10 mM MES and 12% bead treatments maintained pH within the narrowest limits. The pH stabilization methods tested did not significantly affect seed oil and protein contents. PMID:11537992

Frick, J; Mitchell, C A

1993-10-01

176

Ph.D. Requirements Fall, 2009 and Forward Approved Ph.D. Training Requirements  

E-print Network

Ph.D. Requirements Fall, 2009 and Forward 1 Approved Ph.D. Training Requirements Requirements effective for Ph.D. programs enrolling students in Fall 2009 and forward Critical Outcomes of a Research-Oriented Ph.D. Program In terms of an overall vision of the Curry Ph.D. graduate, the aims include student

Acton, Scott

177

Sub-mm Jet Properties of the X-Ray Binary Swift J1745$-$26  

E-print Network

We present the results of our observations of the early stages of the 2012--2013 outburst of the transient black hole X-ray binary (BHXRB), Swift J1745$-$26, with the VLA, SMA, and JCMT (SCUBA--2). Our data mark the first multiple-band mm & sub-mm observations of a BHXRB. During our observations the system was in the hard accretion state producing a steady, compact jet. The unique combination of radio and mm/sub-mm data allows us to directly measure the spectral indices in and between the radio and mm/sub-mm regimes, including the first mm/sub-mm spectral index measured for a BHXRB. Spectral fitting revealed that both the mm (230 GHz) and sub-mm (350 GHz) measurements are consistent with extrapolations of an inverted power-law from contemporaneous radio data (1--30 GHz). This indicates that, as standard jet models predict, a power-law extending up to mm/sub-mm frequencies can adequately describe the spectrum, and suggests that the mechanism driving spectral inversion could be responsible for the high mm/s...

Tetarenko, A J; Miller-Jones, J C A; Curran, P A; Russell, T D; Coulson, I M; Heinz, S; Maitra, D; Markoff, S B; Migliari, S; Petitpas, G R; Rupen, M P; Rushton, A P; Russell, D M; Sarazin, C L

2015-01-01

178

Calcification, growth and mortality of juvenile clams Ruditapes decussatus under increased pCO 2 and reduced pH: Variable responses to ocean acidification at local scales?  

Microsoft Academic Search

We investigated the effects of ocean acidification on juvenile clams Ruditapes decussatus (average shell length 10.24mm) in a controlled CO2 perturbation experiment. The carbonate chemistry of seawater was manipulated by diffusing pure CO2, to attain two reduced pH levels (by ?0.4 and ?0.7 pH units), which were compared to unmanipulated seawater. After 75days we found no differences among pH treatments

P. Range; M. A. Chícharo; R. Ben-Hamadou; D. Piló; D. Matias; S. Joaquim; A. P. Oliveira; L. Chícharo

2011-01-01

179

A Polarizable QM/MM Explicit Solvent Model for Computational Electrochemistry in Water  

E-print Network

We present a quantum mechanical/molecular mechanical (QM/MM) explicit solvent model for the computation of standard reduction potentials E[subscript 0]. The QM/MM model uses density functional theory (DFT) to model the ...

Wang, Lee-Ping

180

Experimental characterization and system simulations of depth of interaction PET detectors using 0.5 mm and 0.7 mm LSO arrays  

NASA Astrophysics Data System (ADS)

Small animal PET scanners may be improved by increasing the sensitivity, improving the spatial resolution and improving the uniformity of the spatial resolution across the field of view. This may be achieved by using PET detectors based on crystal elements that are thin in the axial and transaxial directions and long in the radial direction, and by employing depth of interaction (DOI) encoding to minimize the parallax error. With DOI detectors, the diameter of the ring of the PET scanner may also be decreased. This minimizes the number of detectors required to achieve the same solid angle coverage as a scanner with a larger ring diameter and minimizes errors due to non-collinearity of the annihilation photons. In this study, we characterize prototype PET detectors that are finely pixelated with individual LSO crystal element sizes of 0.5 mm × 0.5 mm × 20 mm and 0.7 mm × 0.7 mm × 20 mm, read out at both ends by position sensitive avalanche photodiodes (PSAPDs). Both a specular reflector and a diffuse reflector were evaluated. The detectors were characterized based on the ability to clearly resolve the individual crystal elements, the DOI resolution and the energy resolution. Our results indicate that a scanner based on any of the four detector designs would offer improved spatial resolution and more uniform spatial resolution compared to present day small animal PET scanners. The greatest improvements to spatial resolution will be achieved when the detectors employing the 0.5 mm × 0.5 mm × 20 mm crystals are used. Monte Carlo simulations were performed to demonstrate that 2 mm DOI resolution is adequate to ensure uniform spatial resolution for a small animal PET scanner geometry using these detectors. The sensitivity of such a scanner was also simulated using Monte Carlo simulations and was shown to be greater than 10% for a four ring scanner with an inner diameter of 6 cm, employing 20 detectors per scanner ring.

James, Sara St; Yang, Yongfeng; Wu, Yibao; Farrell, Richard; Dokhale, Purushottam; Shah, Kanai S.; Cherry, Simon R.

2009-07-01

181

Richard Mazurchuk, PhD  

Cancer.gov

Dr. Richard Mazurchuk received a BS in Physics and MS and PhD in Biophysics from SUNY Buffalo. His research focused on developing novel multi-modality imaging techniques, contrast (enhancing) agents and methods to assess the efficacy of experimental therapeutics. He subsequently joined the faculty of SUNY Buffalo School of Medicine and Roswell Park Cancer Institute attaining the rank of Assoc Prof in the Departments of Diagnostic Imaging and Molecular and Cellular Biochemistry and Biophysics.

182

Christos Patriotis, PhD  

Cancer.gov

Dr. Christos Patriotis obtained his MSc in Biochemistry from the University of Sofia, Bulgaria in 1985 and his PhD in Molecular Biology from the Bulgarian Academy of Sciences in 1990. Postdoctoral training focused on signal transduction and tumor cell biology. He joined the faculty at Fox Chase Cancer Center in 1998; his research was directed toward understanding mechanisms of breast and ovarian cancer pathogenesis and identification of biomarkers associated with the early stages of the two types of cancer.

183

Gastric pH and motility in a porcine model of acute lung injury using a wireless motility capsule  

PubMed Central

Summary Background Evaluation of gastric pH and motility in a porcine model of acute lung injury using a novel, wireless motility capsule. Material/Methods A motility capsule was applied into the stomach of 7 Pietrain pigs with acute lung injury induced by high volume saline lavage. Wireless transmission of pH, pressure and temperature data was performed by a recorder attached to the animal’s abdomen. Gastric motility was evaluated using pH and pressure values, and capsule location was confirmed by autopsy. Results Gastric pH values were statistically significantly different (P<0.003) in the animals over time and ranged from 1.15 to 9.94 [5.73±0.47 (mean ±SD)] with an interquartile range of 0.11 to 2.07. The capsule pressure recordings ranged from 2 to 4 mmHg [2.6±0.5 mmHg (mean ±SD)]. There was no change in pressure patterns or sudden rise of pH >3 pH units during 24 hours. All animals had a gastroparesis with the capsules located in the stomach as indicated by the pressure and pH data and confirmed by necropsy. Conclusions The preliminary data show that Pietrain pigs with acute lung injury have a high variability in gastric pH and severely disturbed gastric motility. PMID:21709625

Rauch, Stefan; Muellenbach, Ralf M.; Johannes, Amélie; Zollhöfer, Bernd; Roewer, Norbert

2011-01-01

184

Nasopharyngeal Carcinoma Patients With Retropharyngeal Lymph Node Metastases: A Minimum Axial Diameter of 6 mm Is a More Accurate Prognostic Predictor Than 5 mm.  

PubMed

OBJECTIVE. The criteria for the diagnosis of metastatic retropharyngeal lymph nodes (RLNs) have not yet been resolved and are not included in the current edition of the American Joint Committee on Cancer (AJCC) staging system (seventh edition) for the staging of nasopharyngeal carcinoma (NPC). The aim of this study was to use MRI to identify an RLN size criterion that can accurately predict prognosis in patients with NPC. MATERIALS AND METHODS. Eight hundred seventeen patients with newly diagnosed localized NPC were identified. All of the patients underwent MRI before treatment with definitive radiation therapy. All the MRI studies and medical records were reviewed retrospectively. Overall survival (OS), distant metastasis-free survival (DMFS), and local relapse-free survival (LRFS) were assessed using SPSS software (version 17.0). RESULTS. RLN size cutoffs of ? 5 mm and of ? 6 mm were used. There was no signifi-cant difference in OS (p = 0.216), DMFS (p = 0.081), or LRFS (p = 0.067) in patients with RLNs ? 5 mm and in those with RLNs < 5 mm. When 6 mm was used as a size cutoff, significant differences in OS (p = 0.000) and DMFS (p = 0.001) were identified; there was no significant difference observed for LRFS (p = 0.380). CONCLUSION. A minimum axial RLN diameter of 6 mm was a more accurate prognostic predictor in NPC patients with RLN metastases than 5 mm. PMID:25539232

Li, Yi-Zhuo; Xie, Chuan-Miao; Wu, Yao-Pan; Cui, Chun-Yan; Huang, Zi-Lin; Lu, Ci-Yong; Wu, Pei-Hong

2015-01-01

185

Modulation of tomato pericarp firmness through pH and calcium: Implications for the texture of fresh-cut fruit  

Microsoft Academic Search

The effect of pH and calcium on pericarp firmness and pectin solubility was investigated in tomato fruit (Lycopersicon esculentum Mill. ‘Tavira’). Pericarp disks were vacuum-infiltrated with 50mM CaCl2 or with distilled water and incubated for 4h in buffer solutions at pH 4.5 and 7.0, and subsequently stored at 2°C for 5 days. CaCl2 treatment had a significant effect on firmness

Susana C. F. Pinheiro; Domingos P. F. Almeida

2008-01-01

186

Intracellular pH and contraction of isolated rabbit and cat papillary muscle: effect of superfusate buffering.  

PubMed

The influence of external buffering on surface pH (pHs), intracellular pH (pHi) and developed twitch tension was investigated in rabbit and cat papillary muscle. pHs and pHi were measured using single and double-barreled microelectrodes respectively. In 20 mM HEPES buffered solution, steady state pHi is close to that in control CO2/HCO-3 (25 mM HCO-3, 5% CO2) solution. pHs and developed tension also do not differ greatly from their control values. Decreasing the HEPES concentration to 5 mM, at constant external pH, lowers pHs considerably. The surface acidosis is associated with a small intracellular acidification; steady state pHi in 5 mM HEPES is always more acid than that in control CO2/HCO-3. A significant decrease in developed tension is also seen in 5 mM HEPES. Alteration of the superfusion velocity influences pHs only slightly. Stimulation of the muscle at high frequency is shown to increase surface acidification, the extent of which is dependent on the buffer concentration. The conclusion from the present experiments is that in papillary muscle external buffering influences intracellular pH and contraction via its effect on pHs. PMID:3989871

Vanheel, B; de Hemptinne, A; Leusen, I

1985-01-01

187

(August 29, 2014) Neuroscience Ph.D.  

E-print Network

HANDBOOK (August 29, 2014) Neuroscience Ph.D. Program Daniel Tranel, PhD Program Director Michael ...................................................................................................4 B. Neuroscience Program Graduate Research Assistantships .................................5 C ......................................................................................................................7 A. Required Core Neuroscience Courses

188

(November 20, 2014) Neuroscience Ph.D.  

E-print Network

HANDBOOK (November 20, 2014) Neuroscience Ph.D. Program Daniel Tranel, PhD Program Director Michael ...................................................................................................4 B. Neuroscience Program Graduate Research Assistantships .................................5 C ......................................................................................................................7 A. Required Core Neuroscience Courses

189

Ph.D. Assessment Form Student Name  

E-print Network

Ph.D. Assessment Form Student Name: Major Advisor: Date: Outcome 1: Graduates will be able to successfully design and conduct original research in their specialty areas. Criterion: Ph.D. candidates related disciplinary areas. Criterion: Ph.D. students will pass their initial preliminary examination

190

Inexpensive and Disposable pH Electrodes  

ERIC Educational Resources Information Center

Inexpensive electrodes for the measurement of pH have been constructed using the ionophore tribenzylamine for sensing H[superscript +] concentrations. Both traditional liquid-membrane electrodes and coated-wire electrodes have been constructed and studied, and both exhibit linear, nearly Nernstian responses to changes in pH. Measurements of pH

Goldcamp, Michael J.; Conklin, Alfred; Nelson, Kimberly; Marchetti, Jessica; Brashear, Ryan; Epure, Emily

2010-01-01

191

University College Dublin PhD Scholarships  

E-print Network

University College Dublin PhD Scholarships UCD Michael Smurfit Graduate Business School invites excellent applications for a number of PhD scholarships starting in September 2014. This provides four years of support for full-time PhD study. The Scholarships are open to full-time EU and non-EU students

192

My PhD Plan Completed Work  

E-print Network

Background My PhD Plan Completed Work Planned Work Hierarchical Biped Control A Exam Matthew Kelly August 4, 2014 Matthew Kelly Hierarchical Biped Control 1 / 34 #12;Background My PhD Plan Completed Work Planned Work Table of Contents 1 Background 2 My PhD Plan 3 Completed Work 4 Planned Work Push Hold Free

Ruina, Andy L.

193

Effects of pH on the Production of Phosphate and Pyrophosphate by Matrix Vesicles' Biomimetics  

PubMed Central

During endochondral bone formation, chondrocytes and osteoblasts synthesize and mineralize the extracellular matrix through a process that initiates within matrix vesicles (MVs) and ends with bone mineral propagation onto the collagenous scaffold. pH gradients have been identified in the growth plate of long bones, but how pH changes affect the initiation of skeletal mineralization is not known. Tissue-nonspecific alkaline phosphatase (TNAP) degrades extracellular inorganic pyrophosphate (ePPi), a mineralization inhibitor produced by ectonucleotide pyrophosphatase/ phosphodiesterase-1 (NPP1), while contributing Pi from ATP to initiate mineralization. TNAP and NPP1, alone or combined, were reconstituted in dipalmitoylphosphatidylcholine (DPPC) liposomes to mimic the microenvironment of MVs. The hydrolysis of ATP, ADP, AMP and PPi was studied at pH 8 and 9 and compared to the data determined at pH 7.4. While catalytic efficiencies in general were higher at alkaline pH, PPi hydrolysis was maximal at pH 8 and indicated a preferential utilization of PPi over ATP, at pH 8 versus 9. In addition, all proteoliposomes induced mineral formation when incubated in a synthetic cartilage lymph (SCL) containing 1 mM ATP as substrate and amorphous calcium phosphate (ACP) or calciumphosphate- phosphatidylserine complexes (PS-CPLX) as nucleators. Propagation of mineralization was significantly more efficient at pHs 7.5 and 8 than at pH 9. Since a slight pH elevation from 7.4 to 8 promotes considerably more hydrolysis of ATP, ADP and AMP primarily by TNAP, this small pH change facilitates mineralization, especially via upregulated PPi hydrolysis by both NPP1 and TNAP, further elevating the Pi/PPi ratio, thus enhancing bone mineralization. PMID:23942722

Simão, Ana Maria S.; Bolean, Maytê; Hoylaerts, Marc F.; Millán, José Luis; Ciancaglini, Pietro

2013-01-01

194

Development and application of specially-focused ultrasonic transducers to location and sizing of defects in 75 mm- to 127 mm-thick austenitic stainless steel weld metals  

SciTech Connect

Special UT transducer parts, capable of focusing incident signals within a 25 mm {times} 25 mm {times} 25 mm volume in an austenitic stainless weld metal at depths that varied from 25 mm to 127 mm, were developed and demonstrated to be capable of detecting a defect with cross section equivalent to that of a 4.76 mm-dia flat-bottom hole. Defect length sizing could be accomplished to {plus_minus}50% for 100% of the time and to {plus_minus}25% on selected defect types as follows: porosity groups, 100%; cracks, 67%; combined slag and porosity, 60%; and linear slag indications, 59%. Extensive linear elastic-fracture-mechanics analyses were performed to establish allowable defect sizes at functions of stress, based on a cyclic-life criterion of 10{sup 3} full power cycles of the MFTF-B magnet system. These defect sizes were used to determine which UT indicating were to be removed and repaired and which were to be retained and their recorded sizes and locations.

Dalder, E.N.C.; Benson, S.; McKinley, B.J.; Carodiskey, T.

1992-08-01

195

Soil pH and Fertilizers  

NSDL National Science Digital Library

This Web site by the Mississippi State University Extension Service discusses why fertilizers are added to soils. The Web site begins by introducing the concept of the pH of the soil and how nutrients are affected by this pH level. Students can then learn about the pH logarithmic scale and about the factors that affect soil pH. At the end of the site, users will find a clear and concise table concerning different fertilizer materials characteristics including their speed of reaction and effect on pH in soils.

196

Soils - Part 4: Soil pH  

NSDL National Science Digital Library

Soil pH is defined and its implications for crop production are described in this lesson. How are soil pH and buffer pH determined? How are these assessments used in lime recommendations? The factors that influence pH variations in soils, the chemistry involved in changing the pH of a soil, and the benefits associated with liming acid soils will be discussed.[This lesson, as well as the other nine lessons in the Soils series, is taken from the "Soils Home Study Course," published in 1999 by the University of Nebraska Cooperative Extension.

197

PhD in Sustainable Development PhD in Sustainable Development  

E-print Network

PhD in Sustainable Development PhD in Sustainable Development 2013-2014 Handbook John Colin Mutter................................................................................................ 39 #12;3 PhD in Sustainable Development I. About the Program The sustainability of development in the social, natural, engineering or health sciences. The PhD in Sustainable Development combines

Qian, Ning

198

Effects of Atmospheric Air Plasma Irradiation on pH of Water  

NASA Astrophysics Data System (ADS)

We have studied the effects of atmospheric air plasma irradiation to water using a scalable dielectric barrier discharge device. Measurements of the pH of water treated by the plasmas have shown the pH decreases due to peroxide molecules generated by plasma irradiation and depends on material of water container. We also found this plasma treated water has little effect on the growth enhancement on Radish sprouts compare with plasma irradiation on dry seeds and the plasma irradiation can affect them through the water buffer of 0.2?mm in thickness.

Sarinont, Thapanut; Koga, Kazunori; Kitazaki, Satoshi; Uchida, Giichirou; Hayashi, Nobuya; Shiratani, Masaharu

199

Extrabranchial mechanisms of systemic pH recovery in hagfish (Eptatretus stoutii).  

PubMed

This study investigates the role of branchial and extrabranchial processes in acid-base regulation in the Pacific Hagfish (Eptatretus stoutii). Hagfish were injected with one of the following solutions: acid saline (250mM HCl [pH=0.60], 250mM NaCl), alkaline saline (250mM NaHCO3, 250mM NaCl, [pH?8.43]) or control saline (500mM NaCl) in order to achieve an acid/alkaline/saline load of 6000?mol·kg(-1). Using a custom designed hagfish compartmentalizing flux chamber, we partitioned flux of net acid or base equivalents and ammonia into the anterior (gill+skin) and posterior (skin+intestinal/renal/cloacal) components. We found that Pacific hagfish excrete H(+) primarily via branchial mechanisms but base excretion occurs through extrabranchial mechanisms located in the posterior region. In addition, we demonstrate that hagfish are able to excrete ammonia via the skin although this flux was not involved in compensation from an acid-base disturbance. PMID:24291660

Clifford, Alexander M; Guffey, Samuel C; Goss, Greg G

2014-02-01

200

Cyclic variations in nitrogen uptake rate of soybean plants: effects of pH and mixed nitrogen sources  

NASA Technical Reports Server (NTRS)

To determine if the daily pattern of NO3- and NH4+ uptake is affected by acidity or NO3- : NH4+ ratio of the nutrient solution, non-nodulated soybean plants (Glycine max) were exposed for 21 days to replenished, complete nutrient solutions at pH 6.0, 5.5, 5.0, and 4.5 which contained either 1.0 mM NH4+, 1.0 mM NO3- [correction of NO3+], 0.67 mM NH4+ plus 0.33 mM NO3- (2:1 NH4+ : NO3-) [correction of (2:1 NH3+ : NO4-)], or 0.33 mM NH4+ plus 0.67 mM NO3- (1:2 NH4+ : NO3-). Net uptake rates of NH4+ and NO3- were measured daily by ion chromatography as depletion from the replenished solutions. When NH4+ and NO3- were supplied together, cumulative uptake of total nitrogen was not affected by pH or solution NH4+ : NO3- ratio. The cumulative proportion of nitrogen absorbed as NH4+ decreased with increasing acidity; however, the proportional uptake of NH4+ and NO3- was not constant, but varied day-to-day. This day-to-day variation in relative proportions of NH4+ and NO3- absorbed when NH4+ : NO3- ratio and pH of solution were constant indicates that the regulatory mechanism is not directly competitive. Regardless of the effect of pH on cumulative uptake of NH4+, the specific nitrogen uptake rates from mixed and from individual NH4+ and NO3- sources oscillated between maxima and minima at each pH with average periodicities similar to the expected interval of leaf emergence.

Raper, C. D. Jr; Vessey, J. K.; Henry, L. T.; Chaillou, S.

1991-01-01

201

Role of the GRO family of chemokines in monocyte adhesion to MM-LDL-stimulated endothelium.  

PubMed Central

We have previously shown that treatment of endothelial cells with minimally modified LDL (MM-LDL) induces the binding of monocytes to unknown endothelial receptor molecules. We now report that a member of the GRO family of chemokines plays a role in MM-LDL-induced monocyte binding. A cDNA library made from rabbit aortic endothelial cells (RAEC) treated with MM-LDL was expression screened for molecules inducing binding of a human monocyte cell line (THP-1). A cDNA was isolated with 75% homology to GRO. GRO mRNA levels were significantly elevated after exposure of RAEC or human aortic endothelial cells (HAEC) to MM-LDL. HAEC treated with MM-LDL displayed an increase in a surface-associated protein that bound to antibody against GRO despite low levels of GRO in the medium. Antibody to GRO significantly inhibited the binding of monocytes to MM-LDL-treated RAEC and HAEC. The increase in GRO expression and monocyte binding were reduced by incubating MM-LDL-treated endothelial cells with heparin (in a method that releases heparan sulfate bound molecules from the cell surface). These results suggest that GRO related chemokines are bound to the surface of MM-LDL-treated endothelial cells and may contribute to the monocyte adhesion induced by MM-LDL. Images PMID:7962543

Schwartz, D; Andalibi, A; Chaverri-Almada, L; Berliner, J A; Kirchgessner, T; Fang, Z T; Tekamp-Olson, P; Lusis, A J; Gallegos, C; Fogelman, A M

1994-01-01

202

Experimental Media, Component List Component MW g/mol Ames mg/L Ames mM L-15 mg/L L-15 mM BME mg/L BME mM Locke's mg/L Locke's mM  

E-print Network

Experimental Media, Component List Component MW g/mol Ames mg/L Ames mM L-15 mg/L L-15 mM BME mg/L BME mM Locke's mg/L Locke's mM Salts CaCl2 · 2H2O CaCl2 Magnesium Chloride MgSO4 (anhyd) KCl KH2PO4 Na 372.24 2E-02 141.09 423.27 3 66382 100 1.51E-03 http:// www.google.co m/url? sa=t&source=we b&cd=5&ved

Rieke, Fred

203

The pH Factor  

NSDL National Science Digital Library

The Miami Museum of Science's learning site, The pH Factor, gives teachers a fun and interactive way to teach elementary and middle school students some basics of science. Material is divided into seven learning areas: excite, explore, explain, expand, extend, exchange, and examine. Each contains an interactive screen that can be used directly in the classroom and lesson plans that correspond with each subject. For example, the excite area contains the "tasting tongue" that, when clicked, shows the location on the tongue where you taste bitter or sour things. The site's teaching style is based on the proposition that learners need to build their own understanding of new ideas. The unique material that is offered on this site provides educators with an excellent alternative for teaching these sometimes difficult concepts to grade school students.

204

PhET Simulation: Sound  

NSDL National Science Digital Library

This interactive simulation allows users to analyze the properties of sound waves. Frequency and amplitude can be controlled, and users can enable audio tones to explore how pitch is related to frequency. Other options allow users to experiment with constructive and destructive interference by moving positions of speakers and listeners. Tools are also provided to measure wavelengths of various frequencies. Experimenting with interference from a wall and exploring sound in environments without air pressure are also possible. This simulation is part of a large and growing collection developed by the Physics Educational Technology Project using research-based principles. See the Related Materials below for a link to clicker questions and tutorials designed specifically for this simulation by the PhET team.

2008-10-29

205

In Vivo Model to Test Implanted Biosensors for Blood pH  

NASA Technical Reports Server (NTRS)

Biosensors for monitoring physiologic data continuously through telemetry are available for heart rate, respiration, and temperature but not for blood pH or ions affected by hydrogen ion concentration. A telemetric biosensor for monitoring blood pH on-line could be used to identify and manage problems in fluid and electrolyte metabolism, cardiac and respiratory function during space flight and the acid-base status of patients without the need for venipuncture in patients on Earth. Critical to the development of biosensors is a method for evaluating their performance after implantation. Mature rats, prepared with jugular, cannulas for repeated blood samples, were exposed to a gas mixture containing high levels of carbon dioxide (7%) in a closed environment to induce mild respiratory acidosis. Serial blood gas and pH measurements in venous blood were compared with electrical responses from sensors implanted in the subcutaneous tissue. Animals became slightly tachypneic after exposure to excess CO2, but remained alert and active. After 5 minutes, basal blood pH decreased from 7.404 +/- 0.013 to 7.289 +/- 0.010 (p less than 0.001)and PC02 increased from 45 +/- 6 to 65 +/- 4 mm. Hg (p les than 0.001). Thereafter pH and blood gas parameters remained stable. Implanted sensors showed a decrease in millivolts (mV) which paralleled the change in pH and averaged 5-6 mV per 0.1 unit pH. Implanted sensors remained sensitive to modest changes in tissue pH for one week. A system for inducing acidosis in rats was developed to test the in vivo performance of pH biosensors. The system provides a method which is sensitive, rapid and reproducible in the same and different animals with full recovery, for testing the performance of sensors implanted in subcutaneous tissues.

Arnaud, Sara B.; Somps, Chris J.; Madou, Marc; Hines, John; Wade, Charles E. (Technical Monitor)

1997-01-01

206

Electronic Absorption Spectra from MM and ab initio QM/MM Molecular Dynamics: Environmental Effects on the Absorption Spectrum of Photoactive Yellow Protein  

PubMed Central

We describe a new interface of the GPU parallelized TeraChem electronic structure package and the Amber molecular dynamics package for quantum mechanical (QM) and mixed QM and molecular mechanical (MM) molecular dynamics simulations. This QM/MM interface is used for computation of the absorption spectra of the photoactive yellow protein (PYP) chromophore in vacuum, aqueous solution, and protein environments. The computed excitation energies of PYP require a very large QM region (hundreds of atoms) covalently bonded to the chromophore in order to achieve agreement with calculations that treat the entire protein quantum mechanically. We also show that 40 or more surrounding water molecules must be included in the QM region in order to obtain converged excitation energies of the solvated PYP chromophore. These results indicate that large QM regions (with hundreds of atoms) are a necessity in QM/MM calculations. PMID:23476156

Isborn, Christine M.; Götz, Andreas W.; Clark, Matthew A.; Walker, Ross C.; Martínez, Todd J.

2012-01-01

207

Antitumor drug Paclitaxel-loaded pH-sensitive nanoparticles targeting tumor extracellular pH  

Microsoft Academic Search

Research efforts have been devoted to demonstrating that the pH-sensitive characteristics of poly NIPAAm\\/chitosan nanoparticles can be applied to targeting tumors. A copolymer of (NIPAAm) and chitosan (4:1, m\\/m) was synthesized, and its drug release characteristics investigated. The results revealed that drug-loaded nanoparticles which encapsulation and loading efficiencies were 85.7% and 9.6%, respectively, exhibited pH-sensitive responses to tumor pH. The

Fan Li; Hong Wu; Hui Zhang; Fei Li; Chun-hu Gu; Qian Yang

2009-01-01

208

Effect of Loading and pH on the Subsurface Demineralization of Dentin Beams  

Microsoft Academic Search

It is important to understand subsurface dentin demineralization and caries from the clinical perspective as dentin properties\\u000a are modified under acidic conditions and mechanical loading. This study was conducted to observe the subsurface demineralization\\u000a of dentin beams at three different pH levels under tension and compression. Bovine dentin beams (10 × 3.75 × 1.45 mm) were\\u000a fixed at one end

P. Mishra; J. E. A. Palamara; M. J. Tyas; M. F. Burrow

2006-01-01

209

Oxygen and pH regulation of protein synthesis in mitochondria from Artemia franciscana embryos.  

PubMed Central

To identify factors responsible for the down-regulation of mitochondrial biosynthetic processes during anoxia in encysted Artemia franciscana embryos, the effects of oxygen limitation and pH on protein synthesis were investigated in isolated mitochondria. At the optimal pH of 7.5, exposure of mitochondria to anoxia decreases the protein synthesis rate by 79%. Rates were suppressed by a further 10% at pH 6.8, the intracellular pH (pHi) measured under anoxia in vivo. Matrix pH, measured under identical conditions, was 8.43 +/- 0.01 at an extra-mitochondrial pH of 7.9 (mean +/- S.E.M., n = 3), 8.05 +/- 0.01 at pH 7.5, and 7.10 +/- 0.01 at pH 6.8. The matrix pH did not vary (P > or = 0.20) as a function of oxygen availability during the 1 h assays. Intramitochondrial purine nucleotides varied little as a function of pH. In contrast, after 1 h of protein synthesis under anoxia, ATP levels decreased by up to 40%, whereas AMP, ADP and GDP concentrations increased, and GTP and GMP concentrations remained relatively constant. The addition of 1 mM ATP at the onset of anoxia maintained the ATP/ADP ratio at the aerobic value, but did not stabilized the GTP/GDP ratio or rescue rates of protein synthesis. Thus, at present, we cannot eliminate the possibility that the decrease in the GTP/GDP ratio during anoxia may contribute to the suppression of protein synthesis. The effect of anoxia was reversible; the rate of protein synthesis upon reoxygenation after a 30 min bout of anoxia was comparable (P = 0.14) with the pre-anoxic rate (193 +/- 17 and 174 +/- 6 pmol of leucine per mg of protein respectively, mean +/- S.E.M., n = 3). The array of mitochondrial translation products did not differ qualitatively as a function of either oxygen availability or pH. Finally, similar pH profiles for protein synthesis were obtained with either [3H]leucine or [3H]histidine (known to use different transporters). Consequently, it is improbable that the pH-sensitivity of protein synthesis can be explained by a specific protein effect on the import of the radiolabelled amino acid used. In summary, both oxygen limitation and acidic pH suppress rates of mitochondrial protein synthesis and are likely to contribute to the arrest of mitochondrial anabolic processes during anoxia-induced quiescence in A. franciscana embryos. PMID:8546685

Kwast, K E; Hand, S C

1996-01-01

210

Young’s modulus calculations for cellulose Iß by MM3 and quantum mechanics  

Technology Transfer Automated Retrieval System (TEKTRAN)

Quantum mechanics (QM) and molecular mechanics (MM) calculations were performed to elucidate Young’s moduli for a series of cellulose Iß models. Computations using the second generation empirical force field MM3 with a disaccharide cellulose model, 1,4'-O-dimethyl-ß-cellobioside (DMCB), and an analo...

211

The M/M Center: Meeting the Demand for Multicultural, Multilingual Teacher Preparation  

ERIC Educational Resources Information Center

The Multilingual/Multicultural Teacher Preparation Center (M/M Center), a teacher preparation program offered by the Bilingual/Multicultural Education Department (BMED) at California State University, Sacramento, is entering its third decade of operation. The M/M Center was established by a group of progressive teacher educators, most with a…

Wong, Pia Lindquist; Murai, Harold; Berta-Avila, Margarita; William-White, Lisa; Baker, Susan; Arellano, Adele; Echandia, Adriana

2007-01-01

212

Energy resolution tests of 125 mm diameter cylindrical NE213 detector using monoenergetic gamma rays  

NASA Astrophysics Data System (ADS)

Pulse height tests have been carried out for cylindrical NE213 liquid scintillation detectors of diameters 50 and 125 mm, using monoenergetic gamma rays. The 125 and 50 mm NE213 scintillator cells, each having a thickness of 50 mm, were directly coupled to 130 mm and 52 mm diameter photomultipliers respectively. Gamma-gamma coincidence technique was used to determine the detector's energy resolution and pulse height corresponding to the maximum energy of Compton electrons over the gamma rays energy range of 0.5-1.2 MeV. For the 125 mm detector, the energy corresponding to half height of Compton maxima is 14.4-6.6% higher than the maximum energy of Compton electrons while its energy resolution varies from 24.0 to 18.0%. For the 50 mm detector the energy corresponding to half height of Compton maxima is 9.8-4.0% higher than the maximum energy of Compton electrons while its energy resolution varies from 18.8 to 12.2%. For the 125 mm diameter detector results are presented for the first time.

Naqvi, A. A.; Al-Juwair, H.; Gul, K.

1991-08-01

213

HES SIMULATION STUDY USING CUBE DATA FROM MM5 Fengying Sun  

E-print Network

P1.37 HES SIMULATION STUDY USING CUBE DATA FROM MM5 Fengying Sun * , Jun Li * , Timothy J. Schmit and spatial resolutions. The atmospheric cube data from the output of PSU/NCAR MM5 version 3.5 (Grell etc to simulate HES top of atmosphere clear sky radiances by a fast forward model (Hannon et al. 1996). These cube

Li, Jun

214

Hans Peter Schwefel Wireless Networks III, Fall 2005: MM3, Wireless Services  

E-print Network

Initiation Protocol (SIP) · IP based multimedia subsystems (IMS) 5. Summary Page 8 Hans Peter Schwefel@kom.auc.dk http://www.kom.auc.dk/~hps http://www.kom.auc.dk/~tatiana · Mm1 IP Mobility Support (HPS) · Mm2 DNS Video Streaming Multimedia Conferencing HTTP, FTP, telnet, SMTP, NNTP #12;Page 3 Hans Peter

Schwefel, Hans-Peter

215

Improved GaAs-based quantum cascade laser (l $ 11 mm) using high-reflectivity  

E-print Network

Improved GaAs-based quantum cascade laser (l $ 11 mm) using high-reflectivity metal facet coating C to the rear facet of a GaAs-based quantum cascade laser operating at l $ 11.5 mm, the threshold current hasP-based quantum cascade lasers has been shown to improve laser performance, extending pulsed and CW operation

216

Anthropogenic carbon and ocean pH  

Microsoft Academic Search

ocean 1 with potentially adverse consequences for marine biota 2-4 . We quantify pH changes that may result from continued release of fossil-fuel CO 2 to the atmosphere, and compare these with pH changes inferred from geological and historical records. We conclude that releasing fossil-fuel CO 2 to the atmosphere over several centuries may result in ocean pH changes greater

K. Caldeira; Michael E. Wickett

2003-01-01

217

Middle School and pH?  

NSDL National Science Digital Library

A local middle school requested that the Water Center of Advanced Materials for Purification of Water With Systems (WaterCAMPWS), a National Science Foundation Science and Technology Center, provide an introduction to pH for their seventh-grade water-based service learning class. As a result, the grade-appropriate, hands-on laboratory, "Creating the pH Scale" was developed to help students grasp the fundamentals of pH.

Susan Herricks

2007-02-01

218

Pyrite oxidation at circumneutral pH  

Microsoft Academic Search

Previous studies of pyrite oxidation kinetics have concentrated primarily on the reaction at low pH, where Fe(III) has been assumed to be the dominant oxidant. Studies at circumneutral pH, necessitated by effective pH buffering in some pyrite oxidation systems, have often implicitly assumed that the dominant oxidant must be dissolved oxygen (DO), owing to the diminished solubility of Fe(III). In

C. O Moses; J. S Herman

1991-01-01

219

Effects of pH and elevated glucose levels on the electrochemical behavior of dental implants.  

PubMed

Implant failure is more likely to occur in persons with medically compromising systemic conditions, such as diabetes related to high blood glucose levels and inflammatory diseases related to pH levels lower than those in healthy people. The aim of this study was to investigate the effects of lower pH level and simulated- hyperglycemia on implant corrosion as these effects are critical to biocompatibility and osseointegration. The electrochemical corrosion properties of titanium implants were studied in four different solutions: Ringer's physiological solution at pH = 7.0 and pH = 5.5 and Ringer's physiological solution containing 15 mM dextrose at pH = 7 and pH = 5.5. Corrosion behaviors of dental implants were determined by cyclic polarization test and electrochemical impedance spectroscopy. Surface alterations were studied using a scanning electron microscope. All test electrolytes led to apparent differences in corrosion behavior of the implants. The implants under conditions of test exhibited statistically significant increases in I(corr) from 0.2372 to 1.007 ?Acm(-2), corrosion rates from 1.904 to 8.085 mpy, and a decrease in polarization resistances from 304 to 74 ?. Implants in dextrose-containing solutions were more prone to corrosion than those in Ringer's solutions alone. Increasing the acidity also yielded greater corrosion rates for the dextrose-containing solutions and the solutions without dextrose. PMID:24779948

Tamam, Evsen; Turkyilmaz, Ilser

2014-04-01

220

Kinetic Equivalence of Transmembrane pH and Electrical Potential Differences in ATP Synthesis*  

PubMed Central

ATP synthase is the key player of Mitchell's chemiosmotic theory, converting the energy of transmembrane proton flow into the high energy bond between ADP and phosphate. The proton motive force that drives this reaction consists of two components, the pH difference (?pH) across the membrane and transmembrane electrical potential (??). The two are considered thermodynamically equivalent, but kinetic equivalence in the actual ATP synthesis is not warranted, and previous experimental results vary. Here, we show that with the thermophilic Bacillus PS3 ATP synthase that lacks an inhibitory domain of the ? subunit, ?pH imposed by acid-base transition and ?? produced by valinomycin-mediated K+ diffusion potential contribute equally to the rate of ATP synthesis within the experimental range examined (?pH ?0.3 to 2.2, ?? ?30 to 140 mV, pH around the catalytic domain 8.0). Either ?pH or ?? alone can drive synthesis, even when the other slightly opposes. ?? was estimated from the Nernst equation, which appeared valid down to 1 mm K+ inside the proteoliposomes, due to careful removal of K+ from the lipid. PMID:22253434

Soga, Naoki; Kinosita, Kazuhiko; Yoshida, Masasuke; Suzuki, Toshiharu

2012-01-01

221

Kinetic equivalence of transmembrane pH and electrical potential differences in ATP synthesis.  

PubMed

ATP synthase is the key player of Mitchell's chemiosmotic theory, converting the energy of transmembrane proton flow into the high energy bond between ADP and phosphate. The proton motive force that drives this reaction consists of two components, the pH difference (?pH) across the membrane and transmembrane electrical potential (??). The two are considered thermodynamically equivalent, but kinetic equivalence in the actual ATP synthesis is not warranted, and previous experimental results vary. Here, we show that with the thermophilic Bacillus PS3 ATP synthase that lacks an inhibitory domain of the ? subunit, ?pH imposed by acid-base transition and ?? produced by valinomycin-mediated K(+) diffusion potential contribute equally to the rate of ATP synthesis within the experimental range examined (?pH -0.3 to 2.2, ?? -30 to 140 mV, pH around the catalytic domain 8.0). Either ?pH or ?? alone can drive synthesis, even when the other slightly opposes. ?? was estimated from the Nernst equation, which appeared valid down to 1 mm K(+) inside the proteoliposomes, due to careful removal of K(+) from the lipid. PMID:22253434

Soga, Naoki; Kinosita, Kazuhiko; Yoshida, Masasuke; Suzuki, Toshiharu

2012-03-16

222

Permanent Magnet with Very Low Field Gradient (0.1G/mm) for NMR Spectroscopy  

NASA Astrophysics Data System (ADS)

Nuclear Magnetic Resonance (NMR) is a powerful analytical tool for obtaining chemical, physical and structural information. To produce the uniform fields required, NMR experiments typically employ large, expensive electromagnets and shimming coils. We have developed a small permanent magnet with an iron yoke that produces a field of ˜10 kG with gradient < 0.1G/mm across a 6 mm region for a total field homogeneity of 10 ppm. The system consists of two parallel cylindrical NdFe permanent magnets, 50mm in diameter and 25mm thick, separated by 4mm. The magnets are surrounded by hollow low-carbon steel cylinders with steel caps on each end of the yoke. By adjusting the distance between the yoke caps and the magnet we cancel first-order field strength variations, as shown in simulations. This design is an important innovation for low cost, benchtop NMR systems. *Supported by the NCI MIT-Harvard CCNE.

Ilic, Ognjen; Issadore, David; Hunt, Tom; Westervelt, Robert

2007-03-01

223

Design of the multilayer insulation system for the Superconducting Super Collider 50mm dipole cryostat  

SciTech Connect

The development of the multilayer insulation (MLI) system for the Superconducting Super Collider (SSC) 50 mm collider dipole cryostat is an ongoing extension of work conducted during the 40 mm cryostat program. While the basic design of the MLI system for the 50 mm cryostat resembles that of the 40 mm cryostat, results from measurements of MLI thermal performance below 80K have prompted a re-design of the MLI system for the 20K thermal radiation shield. Presented is the design of the MLI system for the 50 mm collider dipole cryostat, with discussion focusing on system performance, blanket geometry, cost-effective fabrication techniques, and built-in quality control measures that assure consistent thermal performance throughout the SSC accelerator. 16 refs., 8 figs., 2 tabs.

Boroski, W.N.; Nicol, T.H.; Schoo, C.J.

1991-03-01

224

Poster Presentations Marcella Alsan, MD, MPH, PhD  

E-print Network

vaccination: Evidence from the 1985 Turkish campaign Michele Barry, MD; Stephen Luby, MD; Nancy Federspiel, Ph and pain outcomes of diverse interventions Susan Gage, MD; Jeffrey B. Gould, MD; John Oehlert MS; Gary M, PhD; Jay Mitchell, JD; Patrick Archie, PhD; Rebecca Bird, PhD; Doug Bird, PhD; Jennifer Brody, Ph

Kay, Mark A.

225

pH Meter probe assembly  

DOEpatents

An assembly for mounting a pH probe in a flowing solution, such as a sanitary sewer line, which prevents the sensitive glass portion of the probe from becoming coated with grease, oil, and other contaminants, whereby the probe gives reliable pH indication over an extended period of time. The pH probe assembly utilizes a special filter media and a timed back-rinse feature for flushing clear surface contaminants of the filter. The flushing liquid is of a known pH and is utilized to check performance of the probe.

Hale, Charles J. (San Jose, CA)

1983-01-01

226

pH Meter probe assembly  

DOEpatents

An assembly for mounting a pH probe in a flowing solution, such as a sanitary sewer line, which prevents the sensitive glass portion of the probe from becoming coated with grease, oil, and other contaminants, whereby the probe gives reliable pH indication over an extended period of time. The pH probe assembly utilizes a special filter media and a timed back-rinse feature for flushing clear surface contaminants of the filter. The flushing liquid is of a known pH and is utilized to check performance of the probe. 1 fig.

Hale, C.J.

1983-11-15

227

Administration Donald B. Thomason, PhD  

E-print Network

D Cell Biology & Physiology Radhakrishna Rao, PhD Microbiology, Immunology & Biochemistry Elizabeth Affairs Medical Center, the University of Memphis, the University of Tennessee, Knoxville, Oak Ridge

Cui, Yan

228

UNIVERSITY of PENNSYLVANIA Ph.D. PROGRAM  

E-print Network

UNIVERSITY of PENNSYLVANIA Ph.D. PROGRAM GUIDELINES FOR GRADUATE STUDY September 2010 Mechanical Engineering and Applied Mechanics School of Engineering and Applied Science University of Pennsylvania 229

Carpick, Robert W.

229

UNIVERSITY of PENNSYLVANIA Ph.D. PROGRAM  

E-print Network

UNIVERSITY of PENNSYLVANIA Ph.D. PROGRAM GUIDELINES FOR GRADUATE STUDY September 2011 Mechanical Engineering and Applied Mechanics School of Engineering and Applied Science University of Pennsylvania 229

Carpick, Robert W.

230

UNIVERSITY of PENNSYLVANIA Ph.D. PROGRAM  

E-print Network

UNIVERSITY of PENNSYLVANIA Ph.D. PROGRAM GUIDELINES FOR GRADUATE STUDY September 2009 Mechanical Engineering and Applied Mechanics School of Engineering and Applied Science University of Pennsylvania 229

Carpick, Robert W.

231

UNIVERSITY of PENNSYLVANIA Ph.D. PROGRAM  

E-print Network

UNIVERSITY of PENNSYLVANIA Ph.D. PROGRAM GUIDELINES FOR GRADUATE STUDY September 2013 Mechanical Engineering and Applied Mechanics School of Engineering and Applied Science University of Pennsylvania 229

Carpick, Robert W.

232

UNIVERSITY of PENNSYLVANIA Ph.D. PROGRAM  

E-print Network

UNIVERSITY of PENNSYLVANIA Ph.D. PROGRAM GUIDELINES FOR GRADUATE STUDY September 2012 Mechanical Engineering and Applied Mechanics School of Engineering and Applied Science University of Pennsylvania 229

Carpick, Robert W.

233

pH jump induced ?-helix folding.  

NASA Astrophysics Data System (ADS)

pH can be used to impact the folding equilibrium of peptides and proteins. This fact is utilized, similarly to temperature jumps, in pH jump experiments employing laser time-resolved spectroscopy to study the function and structural dynamics of these molecules. Here the application of pH jumps in folding experiments was investigated. Experiments with poly-L-glutamic acid alpha-helix formation shown the critical aspects of pH jump experiments and yielded direct information about the folding kinetics monitored with the amide I IR band.

Donten, M. L.; Hamm, P.

2013-03-01

234

Effect of temperature, pH, and ions on sweet taste.  

PubMed

The purpose of this experiment was to determine the effects of temperature (50 degrees C and 6 degrees C), pH (pH 3.0, 4.0, 5.0, 6. 0, and 7.0) and the addition of monovalent and divalent cations (5 mM Na(+), 5 mM K(+), and 5 mM Ca(2)+ ) on the sweetness intensity ratings of sweeteners ranging widely in chemical structure. A trained panel provided intensity evaluations for prototypical tastes (sweet, bitter, sour, and salty) as well as aromatic and mouth-feel attributes. The following sweeteners were included in this experiment: three sugars (fructose, glucose, sucrose), three terpenoid glycosides (monoammonium glycyrrhizinate, rebaudioside-A, stevioside), two polyhydric alcohols (mannitol, sorbitol), two dipeptide derivatives (alitame, aspartame), two N-sulfonylamides (acesulfame-K, sodium saccharin), one sulfamate (sodium cyclamate), one protein (thaumatin), one dihydrochalcone (neohesperidin dihydrochalcone), and one chlorodeoxysugar (sucralose). Two to five levels of each sweetener reflecting a range of sweetness intensities were tested, using formulae developed by DuBois et al. The main finding from this three-part study was that temperature, pH, and ions had little effect on perceived sweetness intensity. Even when significant differences were found in the temperature study, the effects were very small. PMID:10713286

Schiffman, S S; Sattely-Miller, E A; Graham, B G; Bennett, J L; Booth, B J; Desai, N; Bishay, I

2000-02-01

235

Quantification of iopamidol multi-site chemical exchange properties for ratiometric chemical exchange saturation transfer (CEST) imaging of pH.  

PubMed

pH-sensitive chemical exchange saturation transfer (CEST) MRI holds great promise for in vivo applications. However, the CEST effect depends on not only exchange rate and hence pH, but also on the contrast agent concentration, which must be determined independently for pH quantification. Ratiometric CEST MRI normalizes the concentration effect by comparing CEST measurements of multiple labile protons to simplify pH determination. Iopamidol, a commonly used x-ray contrast agent, has been explored as a ratiometric CEST agent for imaging pH. However, iopamidol CEST properties have not been solved, determination of which is important for optimization and quantification of iopamidol pH imaging. Our study numerically solved iopamidol multi-site pH-dependent chemical exchange properties. We found that iopamidol CEST MRI is suitable for measuring pH between 6 and 7.5 despite that T1 and T2 measurements varied substantially with pH and concentration. The pH MRI precision decreased with pH and concentration. The standard deviation of pH determined from MRI was 0.2 and 0.4 pH unit for 40 and 20?mM iopamidol solution of pH 6, and it improved to be less than 0.1 unit for pH above 7. Moreover, we determined base-catalyzed chemical exchange for 2-hydrooxypropanamido (ksw = 1.2*10(pH-4.1)) and amide (ksw = 1.2*10(pH-4.6)) protons that are statistically different from each other (P < 0.01, ANCOVA), understanding of which should help guide in vivo translation of iopamidol pH imaging. PMID:25054859

Sun, Phillip Zhe; Longo, Dario Livio; Hu, Wei; Xiao, Gang; Wu, Renhua

2014-08-21

236

Quantification of iopamidol multi-site chemical exchange properties for ratiometric chemical exchange saturation transfer (CEST) imaging of pH  

NASA Astrophysics Data System (ADS)

pH-sensitive chemical exchange saturation transfer (CEST) MRI holds great promise for in vivo applications. However, the CEST effect depends on not only exchange rate and hence pH, but also on the contrast agent concentration, which must be determined independently for pH quantification. Ratiometric CEST MRI normalizes the concentration effect by comparing CEST measurements of multiple labile protons to simplify pH determination. Iopamidol, a commonly used x-ray contrast agent, has been explored as a ratiometric CEST agent for imaging pH. However, iopamidol CEST properties have not been solved, determination of which is important for optimization and quantification of iopamidol pH imaging. Our study numerically solved iopamidol multi-site pH-dependent chemical exchange properties. We found that iopamidol CEST MRI is suitable for measuring pH between 6 and 7.5 despite that T1 and T2 measurements varied substantially with pH and concentration. The pH MRI precision decreased with pH and concentration. The standard deviation of pH determined from MRI was 0.2 and 0.4 pH unit for 40 and 20?mM iopamidol solution of pH 6, and it improved to be less than 0.1 unit for pH above 7. Moreover, we determined base-catalyzed chemical exchange for 2-hydrooxypropanamido (ksw = 1.2*10pH-4.1) and amide (ksw = 1.2*10pH-4.6) protons that are statistically different from each other (P < 0.01, ANCOVA), understanding of which should help guide in vivo translation of iopamidol pH imaging.

Zhe Sun, Phillip; Livio Longo, Dario; Hu, Wei; Xiao, Gang; Wu, Renhua

2014-08-01

237

Quercetin sensitizes cells in a tumour-like low pH environment to hyperthermia.  

PubMed

Quercetin has been shown to act as a hyperthermia sensitizer by inhibiting the synthesis of heat shock protein 70 (HSP70) in a variety of tumour cell lines. It is most effective under conditions of low pH. This study was designed to test the hypothesis that quercetin suppresses thermotolerance development in cells adapted to growth at low pH and renders them as responsive as acutely acidified cells to hyperthermia-induced cytotoxicity. Chinese hamster ovarian carcinoma cells (OvCa) were exposed to 42 degrees C hyperthermia and/or quercetin (50-200 mm) at their growth pH of either 7.3 or 6.7 or after acute acidification from 7.3 to 6.7. Thermotolerance development was measured by colony survival. HSP70 synthesis and total protein synthesis were measured by radioactive precursor pulse labelling techniques. Quercetin, in a concentration-dependent manner, reduced the rate of total protein synthesis and increased cytotoxicity equally after acute acidification to pH 6.7 or growth at pH 6.7 at 37 degrees C, and to a greater extent than it did in cells at pH 7.3. At 42 degrees C, 100 mm quercetin inhibited total protein synthesis, HSP70 synthesis and thermotolerance development to a similar extent in cells grown at pH 6.7 or acutely acidified to pH 6.7. In contrast, quercetin reduced but did not completely inhibit HSP70 synthesis and thermotolerance development in cells grown and heated at pH 7.3. These results support the hypothesis that quercetin can specifically reduce thermotolerance development in tumour cells adapted to growth at pHe 6.7 so that they respond similarly to acutely acidified cells. Since many tumours are adapted to growth at low pH and may resist a wide variety of therapeutic modalities, inhibition of thermotolerance expression by quercetin may not only enhance the response to hyperthermia but the response to commonly used therapies such as chemotherapy and radiation. PMID:12944166

Wachsberger, P R; Burd, R; Bhala, A; Bobyock, S B; Wahl, M L; Owen, C S; Rifat, S B; Leeper, D B

2003-01-01

238

pH in human tumour xenografts: effect of intravenous administration of glucose.  

PubMed Central

pH frequency distributions of tumours grown s.c. from 30 human tumour xenograft lines in rnu/rnu rats were analysed with the use of H+ ion-sensitive semi-microelectrodes prior to and following stimulation of tumour cell glycolysis by i.v. infusion of glucose. At normoglycemia, the average pH of the tumours investigated was 6.83 (range, 6.72-7.01; n = 268). Without exception, all xenografts responded to the temporary increase in plasma glucose concentration (PGC) from 6 +/- 1 to 30 +/- 3 mM by an accumulation of acidic metabolites, as indicated by a pH reduction to an average value of 6.43 (range, 6.12-6.78; n = 292). This pH value corresponds to a ten-fold increase in H+ ion activity in tumour tissue as compared to arterial blood. Tumour pH approached minimum values at 2-4 h after the onset of glucose administration and could be maintained at acidic levels for 24 h by controlled glucose infusion. Irrespective of pH variations between tumours grown from individual xenograft lines, there was no major difference in pH response to glucose between the four main histopathological tumour entities investigated, i.e. breast, lung and gastrointestinal carcinomas, and sarcomas. In tumours from several xenograft lines, an increase in blood glucose to only 2.5-times the normal value (14 mM) was sufficient to reduce the mean pH to 6.4. Glucose-induced acidosis was tumour-specific. The pH frequency distributions in liver, kidney and skeletal muscle of tumour-bearing rnu/rnu rats were only marginally sensitive to hyperglycemia (average pH, 6.97 vs normal value of 7.14). Tumour-selective activation of pH-sensitive anti-cancer agents, e.g. alkylating drugs, acid-labile prodrugs or pH-sensitive immunoconjugates may thus be feasible in a wide variety of human cancers. PMID:8353039

Volk, T.; Jähde, E.; Fortmeyer, H. P.; Glüsenkamp, K. H.; Rajewsky, M. F.

1993-01-01

239

Anionic tobacco peroxidase is active at extremely low pH: veratryl alcohol oxidation with a pH optimum of 1.8.  

PubMed Central

Tobacco peroxidase (36 kDa, pI 3.5) exhibits unique catalytic and spectral properties that are modulated by pH, calcium and magnesium ions. It catalyses the oxidation of veratryl alcohol by hydrogen peroxide over a wide pH range (1.5-5.0) in the presence of these metal ions with a pH optimum of 1.8. This is the only example of a holoperoxidase described so far that is active and comparatively stable at such a low pH. The enhancement of tobacco peroxidase activity by magnesium ions is to our knowledge the first example of a magnesium-induced peroxidase activation. UV/visible spectra of tobacco peroxidase showed that the Soret band shifted and its absorption coefficient increased upon the addition of calcium or magnesium ions and on lowering the pH. The tobacco peroxidase spectrum at pH 1.85, in the presence of calcium chloride (> 50 mM), is similar to that of lignin peroxidase at pH 6.0, with the Soret band shifting from 403 to 409 nm and the molar absorption coefficient increasing from 108,000 to 148,000 +/- 2000 M-1.cm-1 (results given +/- S.E.M.; n = 3). The data provide evidence for a low-affinity site for bivalent metal ion binding in addition to the two constitutive calcium sites that are present in all plant peroxidases. The presence of a glutamic acid residue (Glu-141) at the entrance to the haem-binding pocket, analogous to Glu-146 in lignin peroxidase and not present in other plant peroxidases, may account for these novel properties. PMID:8973542

Gazarian, I G; Lagrimini, L M; George, S J; Thorneley, R N

1996-01-01

240

Condensation heat transfer characteristics of R410A-oil mixture in 5 mm and 4 mm outside diameter horizontal microfin tubes  

SciTech Connect

Condensation heat transfer characteristics of R410A-oil mixture in 5 mm and 4 mm outside diameter horizontal microfin tubes were investigated experimentally. The experimental condensing temperature is 40 C, and nominal oil concentration range is from 0% to 5%. The test results indicate that the presence of oil deteriorates the heat transfer. The deterioration effect is negligible at nominal oil concentration of 1%, and becomes obvious with the increase of nominal oil concentration. At 5% nominal oil concentration, the heat transfer coefficient of R410A-oil mixture is found to have a maximum reduction of 25.1% and 23.8% for 5 mm and 4 mm tubes, respectively. The predictabilities of the existing condensation heat transfer correlations were verified with the experimental data, and Yu and Koyama correlation shows the best predictability. By replacing the pure refrigerant properties with the mixture's properties, Yu and Koyama correlation has a deviation of -15% to + 20% in predicting the local condensation heat transfer coefficient of R410A-oil mixture. (author)

Huang, Xiangchao; Ding, Guoliang; Hu, Haitao; Zhu, Yu. [Institute of Refrigeration and Cryogenics, Shanghai Jiaotong University, Shanghai 200240 (China); Gao, Yifeng [International Copper Association Shanghai Office, Shanghai 200020 (China); Deng, Bin [Institute of Heat Transfer Technology, Golden Dragon Precise Copper Tube Group Inc., Shanghai 200135 (China)

2010-10-15

241

pH regulation in anoxic rice coleoptiles at pH 3.5: biochemical pHstats and net H+ influx in the absence and presence of NO3?  

PubMed Central

During anoxia, cytoplasmic pH regulation is crucial. Mechanisms of pH regulation were studied in the coleoptile of rice exposed to anoxia and pH 3.5, resulting in H+ influx. Germinating rice seedlings survived a combination of anoxia and exposure to pH 3.5 for at least 4 d, although development was retarded and net K+ efflux was continuous. Further experiments used excised coleoptile tips (7–10 mm) in anoxia at pH 6.5 or 3.5, either without or with 0.2 mM NO3?, which distinguished two processes involved in pH regulation. Net H+ influx (?mol g?1 fresh weight h?1) for coleoptiles with NO3? was ?1.55 over the first 24 h, being about twice that in the absence of NO3?, but then decreased to 0.5–0.9 as net NO3? uptake declined from ?1.3 to 0.5, indicating reduced uptake via H+–NO3? symports. NO3? reduction presumably functioned as a biochemical pHstat. A second biochemical pHstat consisted of malate and succinate, and their concentrations decreased substantially with time after exposure to pH 3.5. In anoxic coleoptiles, K+ balancing the organic anions was effluxed to the medium as organic anions declined, and this efflux rate was independent of NO3? supply. Thus, biochemical pHstats and reduced net H+ influx across the plasma membrane are important features contributing to pH regulation in anoxia-tolerant rice coleoptiles at pH 3.5. PMID:22174442

Greenway, Hank; Kulichikhin, Konstantin Y.; Cawthray, Gregory R.; Colmer, Timothy D.

2012-01-01

242

Sealing vessels up to 7 mm in diameter solely with ultrasonic technology  

PubMed Central

Introduction Ultrasonic energy is a mainstay in the armamentarium of surgeons, providing multifunctionality, precision, and control when dissecting and sealing vessels up to 5 mm in diameter. Historically, the inability to seal vessels in the 5–7 mm range has been perceived as an inherent limitation of ultrasonic technology. The purpose of this study was to evaluate sealing of vessels up to 7 mm in diameter with an ultrasonic device that modulates energy delivery during the sealing period. Methods In ex vivo benchtop and in vivo acute and survival preclinical models, a new ultrasonic device, Harmonic ACE®+7 Shears (Harmonic 7), was compared with advanced bipolar devices in sealing vessels 1–7 mm in diameter with respect of burst pressure, seal reliability, and seal durability. Lateral thermal damage and transection time were also evaluated. Results Ex vivo tests of Harmonic 7 demonstrated significantly greater median burst pressures than an advanced bipolar device both for vessels <5 mm in diameter (1,078 mmHg and 836 mmHg, respectively, P=0.046) and for those in the range of 5–7 mm (1,419 mmHg and 591 mmHg, P<0.001). In vivo tests in porcine and caprine models demonstrated similar rates of hemostasis between Harmonic 7 and advanced bipolar devices, with high success rates at initial transection and seal durability of 100% after a 30-day survival period. Conclusion Sealing 5–7 mm vessels is not a limitation of the type of energy used but of how energy is delivered to tissue. These studies document the ability of ultrasonic energy alone to reliably seal large vessels 5–7 mm in diameter, with significantly greater burst pressure observed in in vitro studies than those observed with an advanced bipolar technology when energy delivery is modulated during the sealing cycle. Furthermore, the seals created in 5–7 mm vessels are shown to be reliable and durable in in vivo preclinical studies. PMID:25114600

Timm, Richard W; Asher, Ryan M; Tellio, Karalyn R; Welling, Alissa L; Clymer, Jeffrey W; Amaral, Joseph F

2014-01-01

243

Microfabrication of a tapered channel for isoelectric focusing with thermally generated pH gradient.  

PubMed

A simple microfabrication technique for the preparation of a tapered microchannel for thermally generated pH gradient isoelectric focusing (IEF) has been demonstrated. The tapered channel was cut into a plastic sheet (thickness was 120 microm), and the channel was closed by sandwiching the plastic sheet between two glass microscope slides. The length of the microchannel was 5 cm. The width of the separation channel was 0.4 mm at the narrow end and 4 mm at the wide end. The channel was coated with polyacrylamide to prevent electroosmotic flow (EOF) during focusing. Two electrolyte vials were mounted on top of each end of the channel with the wide end of the channel connected to the cathodic vial and the narrow to the anodic vial. The feasibility of the thermally generated pH gradient in a tapered channel was demonstrated. Important parameters that determined the feasibility of using a thermally generated pH gradient in a tapered channel were analyzed. Parameters to be optimized were control of EOF and hydrodynamic flow, selection of power supply mode and prevention of local overheating and air bubble formation. Tris-HCl buffer, which has a high pK(a) dependence with temperature, was used both to dissolve proteins and as the electrolyte. The thermally generated pH gradient separation of proteins was tested by focusing dog, cat and human hemoglobins with a whole column detection capillary IEF (CIEF) system. PMID:12412118

Huang, Tiemin; Pawliszyn, Janusz

2002-10-01

244

The control of intracellular pH in cultured avian chondrocytes.  

PubMed Central

1. Mechanical loading of cartilaginous tissue generates an increase in the concentration of cations in the extracellular matrix. This includes a decrease of the extracellular pH (pHo), which is known to affect the intracellular pH (pHi), thereby modifying the intracellular metabolism. Thus, the regulation of pHi is essential for the physiological function of cartilage. The fluorescent pH-sensitive dye 2',7'-bis(carboxyethyl)-5(6)-carboxyfluorescein acetoxymethyl ester (BCECF AM) was employed in order to assess the mechanisms responsible for control of the pHi in an embryonic avian chondrocyte cell suspension. 2. Steady-state pHi in the absence of physiological HCO3- was 7.15 +/- 0.01 pH units as compared to a pHi of 6.94 +/- 0.02 pH units in its presence (P < 0.01). The intrinsic buffering power of chondrocytes (beta i) was 38.9 mM/pH unit and the total buffering capacity (beta T) was 65.8 mM/pH unit. 3. Cells maintained in a Hepes-buffered solution were exposed to an intracellular acid load by the NH4+ prepulse technique (20 mM NH4Cl). The initial rate of pHi recovery was 0.106 pH units/min (n = 18). Amiloride (0.33 mM), an inhibitor of the Na(+)-H+ exchanger, or replacement of external sodium [Na+]o with choline induced a 60% inhibition of the recovery rate, indicating a predominant involvement of this antiporter in the response to intracellular acidification. 4. H(+)-ATPase inhibitors (oligomycin 20 micrograms/ml; N,N;-dicyclohexylcarbodiimide (DCC), 0.5 mM; N-ethylmaleimide (NEM), 0.25 mM) and iodomycin (2 mM), a metabolic cell suppressor, reduced acid extrusion by 25% as measured by the NH4Cl prepulse in Hepes-bathed cells. 5. Chondrocytes transferred from a Hepes-buffered solution to a 5% CO2-25 mM HCO3- medium (HCO3- solution) underwent a pHi decrease of approximately 0.20 pH units, followed by a regulatory alkalinizing response of 0.118 pH units/min. The Na(+)-H+ exchanger was responsible for only 15% of this alkalinization (amiloride, 0.33 mM), in contrast to its primary role in HCO(3-)-free solution. 6. The activity of a Na(+)-dependent Cl(-)-HCO3- exchanger in physiological HCO3- solution was estimated by addition of the inhibitors 4-acetamido-4'-isothiocyanatostilbene-2,2'-disulphonic acid (SITS; 0.5 mM) or diisothiocyanatostilbene-2,2'-disulphonic acid (DIDS; 100 microM) and by the suspensions of chondrocytes in a Na(+)-free solution. Acidification performed under these conditions resulted in a 45% inhibition of the recovery rate as compared to control rates.(ABSTRACT TRUNCATED AT 400 WORDS) PMID:8394427

Dascalu, A; Nevo, Z; Korenstein, R

1993-01-01

245

Sub-mm observations of X-ray AGN in the William Herschel Deep Field  

E-print Network

We investigate the contribution made by active galactic nuclei (AGN) to the high-redshift, luminous, sub-mm source population using deep ( 3 mJy/beam. Of the 11 identified sub-mm sources, we find that 2 coincide with observed AGN and that, based on their hardness ratios, both of these AGN appear to be heavily obscured. We perform a stacking of the sub-mm data around the AGN, which we group by estimated column density, and find that only the obscured (N_H > 10^{22} cm^2) AGN show significant associated sub-mm emission. These observations support the previous findings of Page et al (2004) and Hill et al (2011b) that obscured AGN preferentially show sub-mm emission. Hill et al (2011b) have argued that, in this case, the contribution to the observed sub-mm emission (and thus the sub-mm background) from AGN heating of the dust in these sources may be higher than previously thought.

Bielby, R M; Metcalfe, N; Shanks, T

2011-01-01

246

An "all 5-mm ports" selective approach to laparoscopic cholecystectomy, appendectomy, and anti-reflux surgery.  

PubMed

Laparoscopic appendectomy, cholecystectomy, or anti-reflux procedures are conventionally performed with the use of one and often two 10/12-mm ports. While needlescopic or micropuncture laparoscopic procedures reduce postoperative pain, they invariably involve the use of one 10/12-mm port and the instruments applied have their ergo-dynamic shortcomings. Between September 2002 and March 2003, we have attempted an "all 5-mm ports" approach in 49 laparoscopic procedures, which included 18 of 59 laparoscopic cholecystectomies (31%), 26 diagnostic laparoscopies for suspected appendicitis (of which we proceeded to a laparoscopic appendectomy in 17 patients), and in the last 5 of 9 laparoscopic Nissen fundoplications. Conversion of one of the 5-mm ports to a 10-mm port was required in 5 of the 18 (28%) laparoscopic cholecystectomies and in 6 of the 17 (35%) laparoscopic appendectomies to facilitate organ retrieval in patients with large gallstones (>5 mm in diameter) and in obese patients with fatty mesoappendix. There were no conversions to open surgery. No significant differences in the operating time between the laparoscopic procedures performed by the all 5-mm ports approach or the conventional approach were observed. No intraoperative or postoperative complications occurred in this series. The "all 5-mm ports" approach to laparoscopic cholecystectomy and appendectomy in selected patients and to laparoscopic fundoplication appears feasible and safe. A randomised comparison between this approach and the conventional laparoscopic approach to elective cholecystectomy and fundoplication in which two of the ports employed are of the 10-mm diameter is warranted. PMID:15471020

El-Dhuwaib, Yesar; Hamade, Ayman M; Issa, M Eyad; Balbisi, Basel M; Abid, Ghalib; Ammori, Basil J

2004-06-01

247

The Herschel Multi-Tiered Extragalactic Survey: SPIRE-mm Photometric Redshifts  

NASA Technical Reports Server (NTRS)

We investigate the potential of submm-mm and submm-mm-radio photometric redshifts using a sample of mm-selected sources as seen at 250, 350 and 500 micron by the SPIRE instrument on Herschel. From a sample of 63 previously identified mm sources with reliable radio identifications in the Great Observatories Origins Deep Survey North and Lockman Hole North fields, 46 (73 per cent) are found to have detections in at least one SPIRE band. We explore the observed submm/mm color evolution with redshift, finding that the colors of mm sources are adequately described by a modified blackbody with constant optical depth Tau = (Nu/nu(sub 0))(exp Beta), where Beta = +1.8 and nu(sub 0) = c/100 micron. We find a tight correlation between dust temperature and IR luminosity. Using a single model of the dust temperature and IR luminosity relation, we derive photometric redshift estimates for the 46 SPIRE-detected mm sources. Testing against the 22 sources with known spectroscopic or good quality optical/near-IR photometric redshifts, we find submm/mm photometric redshifts offer a redshift accuracy of (absolute value of Delta sub (z))/(1 + z) = 0.16 (absolute value of Delta sub (z)) = 0.51). Including constraints from the radio-far-IR correlation, the accuracy is improved to (absolute value of Delta sub (z))/(1 + z) = 0.14 (((absolute value of Delta sub (z))) = 0.45). We estimate the redshift distribution of mm-selected sources finding a significant excess at Z > 3 when compared to approx 8S0 micron selected samples.

Roseboom, I. G.; Ivison, R. J.; Greve, T. R.; Amblard, A.; Arumugam, V.; Auld, R.; Aussel, H.; Bethermin, M.; Blain, A.; Block, J.; Boselli, A.; Brisbin, D.; Buat, V.; Burgarella, D.; Castro-Rodriquez, N.; Cava, A.; Chanial, P.; Chapin, E.; Chapman, S.; Clements, D. L.; Conley, A.; Conversi, L.; Dowell, C. D.; Dunlop, J. S.; Dwek, E.

2012-01-01

248

The Herschel Multi-Tiered Extragalactic Survey: SPIRE-mm Photometric Redshifts  

NASA Technical Reports Server (NTRS)

We investigate the potential of submm-mm and submm-mm-radio photometric red-shifts using a sample of mm-selected sources as seen at 250, 350 and 500 micrometers by the SPIRE instrument on Herschel. From a sample of 63 previously identified mm-sources with reliable radio identifications in the GOODS-N and Lockman Hole North fields 46 (73 per cent) are found to have detections in at least one SPIRE band. We explore the observed submm/mm colour evolution with redshift, finding that the colours of mm-sources are adequately described by a modified blackbody with constant optical depth Tau = (nu/nu(0))beta where beta = +1.8 and nu(0) = c/100 micrometers. We find a tight correlation between dust temperature and IR luminosity. Using a single model of the dust temperature and IR luminosity relation we derive photometric redshift estimates for the 46 SPIRE detected mm-sources. Testing against the 22 sources with known spectroscopic, or good quality optical/near-IR photometric, redshifts we find submm/mm photometric redshifts offer a redshift accuracy of |delta z|/(1+z) = 0.16 (less than |delta z| greater than = 0.51). Including constraints from the radio-far IR correlation the accuracy is improved to |delta z|/(1 + z) = 0.15 (less than |delta z| greater than = 0.45). We estimate the redshift distribution of mm-selected sources finding a significant excess at z greater than 3 when compared to 850 micrometer selected samples.

Roseboom, I. G.; Ivison, R. J.; Greve, T. R.; Amblard, A.; Arumugam, V.; Auld, R.; Aussel, H.; Bethermin, M.; Blain, A.; Bock, J.; Boselli, A.; Brisbin, D.; Buat, V.; Burgarella, D.; Castro-Rodriguez, N.; Cava, A.; Chanial, P.; Chapin, E.; Chapman, S.; Clements, D. L.; Conley, A.; Conversi, L.; Cooray, A.; Dowell, C. D.; Dwek, E.

2011-01-01

249

Acid loading test (pH)  

MedlinePLUS

The acid loading test (pH) measures the ability of the kidneys to send acid to the urine when there is too much acid in the ... Urine with a pH less than 5.3 is normal. Normal value ranges may vary slightly among different laboratories. Some labs use different ...

250

pH. Agricultural Lesson Plans.  

ERIC Educational Resources Information Center

This lesson plan is intended for use in conducting classes on the effect of pH on plant growth. Presented first are an attention step/problem statement and a series of questions and answers designed to convey general information about soil pH and its effect on plants. The following topics are among those discussed: acidity and alkalinity; the…

Southern Illinois Univ., Carbondale. Dept. of Agricultural Education and Mechanization.

251

Nursing PhD 2010 Edition  

E-print Network

Nursing PhD Handbook 2010 Edition 107 Wiggins Rd, Saskatoon SK S7N 5E5 Phone: (306) 966-8239 Fax: (306) 966-6703 Email: grad.nursing@usask.ca #12;Welcome to the College of Nursing Graduate Program & Continuing Nursing Education #12;PhD Manual 2 Table of Contents General Information

Saskatchewan, University of

252

Middle School and pH?  

ERIC Educational Resources Information Center

A local middle school requested that the Water Center of Advanced Materials for Purification of Water With Systems (WaterCAMPWS), a National Science Foundation Science and Technology Center, provide an introduction to pH for their seventh-grade water-based service learning class. After sorting through a multitude of information about pH, a…

Herricks, Susan

2007-01-01

253

PhET Simulation: Balancing Act  

NSDL National Science Digital Library

In this PhETsimulation, you can investigate how a teeter-totter balances, by moving objects of different masses to various positions. Can you make the teeter-totter balance? This is one of a large number of physics simulations produced at the University of Colorado in the PhET project.

2012-04-24

254

CALCULATING THE PH OF CALCIUM CARBONATE SATURATION  

EPA Science Inventory

Two new expressions for the pH of saturation (pH subs) were derived. One is a simplified equation developed from an aqueous carbonate equilibrium system in which correction for ionic strength was considered. The other is a more accurate quadratic formula that involves computerize...

255

PhD Studentships Biomedical Cell Biology  

E-print Network

PhD Studentships Biomedical Cell Biology Funding available for UK and non-UK applicants The Division of Biomedical Cell Biology at Warwick Medical School seeks applications from candidates for Ph edge of medically relevant cell biology, preparing students for careers in academia, industry

Goldschmidt, Christina

256

Determination Of Ph Including Hemoglobin Correction  

DOEpatents

Methods and apparatuses of determining the pH of a sample. A method can comprise determining an infrared spectrum of the sample, and determining the hemoglobin concentration of the sample. The hemoglobin concentration and the infrared spectrum can then be used to determine the pH of the sample. In some embodiments, the hemoglobin concentration can be used to select an model relating infrared spectra to pH that is applicable at the determined hemoglobin concentration. In other embodiments, a model relating hemoglobin concentration and infrared spectra to pH can be used. An apparatus according to the present invention can comprise an illumination system, adapted to supply radiation to a sample; a collection system, adapted to collect radiation expressed from the sample responsive to the incident radiation; and an analysis system, adapted to relate information about the incident radiation, the expressed radiation, and the hemoglobin concentration of the sample to pH.

Maynard, John D. (Albuquerque, NM); Hendee, Shonn P. (Albuquerque, NM); Rohrscheib, Mark R. (Albuquerque, NM); Nunez, David (Albuquerque, NM); Alam, M. Kathleen (Cedar Crest, NM); Franke, James E. (Franklin, TN); Kemeny, Gabor J. (Madison, WI)

2005-09-13

257

Colorimetric determination of pH  

SciTech Connect

There is a need for a simple, rapid, reliable means for determining pH values of concentrated, high salt solutions without reliance on human eye and ambient light. The method comprises the steps of preparing a set of reference solutions, measuring the light absorption by each reference solution, adding indicator dye to each reference solution, measuring the light absorption by each such reference mixture, comparing the two solutions to determine the dye color at each pH, normalizing the spectra of mixture to the isosbestic point, and matching the color of the pH of the solution to one of the colors of the pHs in the reference solution set. In this way, the pH can be determined to within 0.1 pH unit, a far more precise method than using the human eye.

Baumann, E.W.; Buchanan, B.R.

1991-12-31

258

Parameters affecting downhole pH  

SciTech Connect

The presence of acetic and formic acids in the produced water of gas condensate wells has been known for some time by the industry. In traditional water analysis, it has been titrated and reported as alkalinity. The calculation of accurate downhole pH values requires that these ions be analyzed separately in the water and that an organic acid material balance be performed on all three phases in the separator. In this manner, it is then possible to use phase distribution coefficients involving ionic equilibrium to determine how these acids distribute themselves between phases as the pH calculation proceeds downhole. In this paper, the above method of calculation of pH and {Delta}pH is used to examine the effect that various concentrations of these acids have on the downhole pH. Various concentrations of acids are examined, and two cases are calculated in which the effect of condensate on the pH is examined.

Garber, J.D. [Univ. of Southwestern Louisiana, Lafayette, LA (United States). Corrosion Research Center; Jangama, V.R. [CLI International, Houston, TX (United States); Willmon, J. [Weatherly Labs., Lafayette, LA (United States)

1997-09-01

259

Arsenic bioremediation potential of a new arsenite-oxidizing bacterium Stenotrophomonas sp. MM-7 isolated from soil.  

PubMed

A new arsenite-oxidizing bacterium was isolated from a low arsenic-containing (8.8 mg kg(-1)) soil. Phylogenetic analysis based on 16S rRNA gene sequencing indicated that the strain was closely related to Stenotrophomonas panacihumi. Batch experiment results showed that the strain completely oxidized 500 ?M of arsenite to arsenate within 12 h of incubation in a minimal salts medium. The optimum initial pH range for arsenite oxidation was 5-7. The strain was found to tolerate as high as 60 mM arsenite in culture media. The arsenite oxidase gene was amplified by PCR with degenerate primers. The deduced amino acid sequence showed the highest identity (69.1 %) with the molybdenum containing large subunit of arsenite oxidase derived from Bosea sp. Furthermore the amino acids involved in binding the substrate arsenite, were conserved with the arsenite oxidases of other arsenite oxidizing bacteria such as Alcaligenes feacalis and Herminnimonas arsenicoxydans. To our knowledge, this study constitutes the first report on arsenite oxidation using Stenotrophomonas sp. and the strain has great potential for application in arsenic remediation of contaminated water. PMID:22760225

Bahar, Md Mezbaul; Megharaj, Mallavarapu; Naidu, Ravi

2012-11-01

260

Acidification due to microbial dechlorination near a trichloroethene DNAPL is overcome with pH buffer or formate as electron donor: Experimental demonstration in diffusion-cells  

NASA Astrophysics Data System (ADS)

Acidification due to microbial dechlorination of trichloroethene (TCE) can limit the bio-enhanced dissolution of TCE dense non-aqueous phase liquid (DNAPL). This study related the dissolution enhancement of a TCE DNAPL to the pH buffer capacity of the medium and the type of electron donor used. In batch systems, dechlorination was optimal at pH 7.1-7.5, but was completely inhibited below pH 6.2. In addition, dechlorination in batch systems led to a smaller pH decrease at an increasing pH buffer capacity or with the use of formate instead of lactate as electron donor. Subsequently, bio-enhanced TCE DNAPL dissolution was quantified in diffusion-cells with a 5.5 cm central sand layer, separating a TCE DNAPL layer from an aqueous top layer. Three different pH buffer capacities (2.9 mM-17.9 mM MOPS) and lactate or formate as electron donor were applied. In the lactate fed diffusion-cells, the DNAPL dissolution enhancement factor increased from 1.5 to 2.2 with an increase of the pH buffer capacity. In contrast, in the formate fed diffusion-cells, the DNAPL dissolution enhancement factor (2.4 ± 0.3) was unaffected by the pH buffer capacity. Measurement of the pore water pH confirmed that the pH decreased less with an increased pH buffer capacity or with formate instead of lactate as electron donor. These results suggest that the significant impact of acidification on bio-enhanced DNAPL dissolution can be overcome by the amendment of a pH buffer or by applying a non acidifying electron donor like formate.

Philips, Jo; Maes, Nele; Springael, Dirk; Smolders, Erik

2013-04-01

261

Parameters of tensile strength, elongation, and tenacity of 70mm IIaO spectroscopic film  

NASA Technical Reports Server (NTRS)

The 70mm IIaO spectroscopic film was tested to determine its tensile strength, elongation, and breaking strength, using an Instron (strength and compression) 4201 Test Instrument. These data provide information leading to the upper and lower limits of the above parameters for 70mm IIaO spectroscopic film. This film will be developed by a commercial developing machine after the Ultraviolet Telescope Space Shuttle Mission returns to the Earth in the early 1990's; thus, it is necessary to understand these force parameters. Several test strips of approximately 200mm in length were used. The results indicate that when a stress load of 100 kg was applied, the film elongated approximately 1.06mm and the break strength was 19.45 kilograms.

Hammond, Ernest C., Jr.; Peters, Kevin A.

1989-01-01

262

A dense micro-cluster of Class 0 protostars in NGC 2264 D-MM1  

E-print Network

We present sensitive and high angular resolution (~1") 1.3 mm continuum observations of the dusty core D-MM1 in the Spokes cluster in NGC 2264 using the Submillimeter Array. A dense micro-cluster of seven Class 0 sources was detected in a 20" x 20" region with masses between 0.4 to 1.2 solar masses and deconvolved sizes of about 600 AU. We interpret the 1.3 mm emission as arising from the envelopes of the Class 0 protostellar sources. The mean separation of the 11 known sources (SMA Class 0 and previously known infrared sources) within D-MM1 is considerably smaller than the characteristic spacing between sources in the larger Spokes cluster and is consistent with hierarchical thermal fragmentation of the dense molecular gas in this region.

Paula S. Teixeira; Luis A. Zapata; Charles J. Lada

2007-08-21

263

CD Reference Materials Fabricated on Monolithic 200 mm Wafers for Automated Metrology Tool Applications  

NASA Astrophysics Data System (ADS)

Recently, prototype isolated-line, single-crystal critical dimension (CD) reference materials (SCCDRMs) with linewidths as narrow as 40 nm±1.5 nm have been reported. These reference materials, designated NIST Prototype Reference Material (RM) 8111, were configured as 10 mm by 11 mm silicon test chips mounted in 200 mm carrier wafers. The RM 8111 chips were fabricated using microelectromechanical (MEMS) process techniques, which assure the alignment of the sidewalls of the features to silicon (111) lattice planes, and were calibrated in a sequence involving atomic force microscopy (AFM) and high resolution transmission electron microscopy (HRTEM) metrology. This paper reports initial results on SCCDRMs fabricated on 200 mm bulk wafers; this monolithic approach would eliminate the need for carrier wafers.

Allen, Richard A.; Dixson, Ronald G.; Cresswell, Michael W.; Guthrie, William F.; Shulver, Byron J. R.; Bunting, A. S.; Stevenson, J. T. M.; Walton, Anthony J.

2007-09-01

264

Power supply switching for a mm-wave asymmetric multilevel outphasing power amplifier system  

E-print Network

This thesis demonstrates power switches to be used in our new Asymmetric Multilevel Outphasing (AMO) transmitter architecture at mm-wave frequencies. The AMO topology breaks the linearity vs. efficiency design objective ...

Spaulding, Jonathon David

2010-01-01

265

STS-34 MS Chang-Diaz records onboard activity with 16mm camera  

NASA Technical Reports Server (NTRS)

STS-34 Mission Specialist (MS) Franklin R. Chang-Diaz records forward flight deck activity with ARRIFLEX 16mm camera onboard Atlantis, Orbiter Vehicle (OV) 104. In the background, MS Shannon W. Lucid works at aft flight deck payload station.

1989-01-01

266

5. East portal of Tunnel 26, view to southwest, 135mm ...  

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

5. East portal of Tunnel 26, view to southwest, 135mm lens. Tunnel 25 (HAER CA-201) is visible in the distance. - Central Pacific Transcontinental Railroad, Tunnel No. 26, Milepost 133.29, Applegate, Placer County, CA

267

7. Detail, east portal of Tunnel 34/Snowshed 33, 135mm lens. ...  

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

7. Detail, east portal of Tunnel 34/Snowshed 33, 135mm lens. Tall signal mast necessary in order to be seen above winter snows. - Central Pacific Transcontinental Railroad, Tunnel No. 41, Milepost 193.3, Donner, Placer County, CA

268

MoSI Habitat Assessment Form Location:___ ___ ___ ___ Station:___ ___ ___ ___ Date:____/____/________ (mm/dd/year) Observers  

E-print Network

MoSI Habitat Assessment Form Location:___ ___ ___ ___ Station:___ ___ ___ ___ Date:____/____/________ (mm/dd/year) Observers: Total number of habitat types present:_____ Notes: Habitat Type Letter ____ (from Station Habitat Map) Percent of study area covered by habitat type (determine from Station Habitat

DeSante, David F.

269

pH and Peptide Supply Can Radically Alter Bacterial Populations and Short-Chain Fatty Acid Ratios within Microbial Communities from the Human Colon  

PubMed Central

The effects of changes in the gut environment upon the human colonic microbiota are poorly understood. The response of human fecal microbial communities from two donors to alterations in pH (5.5 or 6.5) and peptides (0.6 or 0.1%) was studied here in anaerobic continuous cultures supplied with a mixed carbohydrate source. Final butyrate concentrations were markedly higher at pH 5.5 (0.6% peptide mean, 24.9 mM; 0.1% peptide mean, 13.8 mM) than at pH 6.5 (0.6% peptide mean, 5.3 mM; 0.1% peptide mean, 7.6 mM). At pH 5.5 and 0.6% peptide input, a high butyrate production coincided with decreasing acetate concentrations. The highest propionate concentrations (mean, 20.6 mM) occurred at pH 6.5 and 0.6% peptide input. In parallel, major bacterial groups were monitored by using fluorescence in situ hybridization with a panel of specific 16S rRNA probes. Bacteroides levels increased from ca. 20 to 75% of total eubacteria after a shift from pH 5.5 to 6.5, at 0.6% peptide, coinciding with high propionate formation. Conversely, populations of the butyrate-producing Roseburia group were highest (11 to 19%) at pH 5.5 but fell at pH 6.5, a finding that correlates with butyrate formation. When tested in batch culture, three Bacteroides species grew well at pH 6.7 but poorly at pH 5.5, which is consistent with the behavior observed for the mixed community. Two Roseburia isolates grew equally well at pH 6.7 and 5.5. These findings suggest that a lowering of pH resulting from substrate fermentation in the colon may boost butyrate production and populations of butyrate-producing bacteria, while at the same time curtailing the growth of Bacteroides spp. PMID:16000778

Walker, Alan W.; Duncan, Sylvia H.; McWilliam Leitch, E. Carol; Child, Matthew W.; Flint, Harry J.

2005-01-01

270

Low-grazing scattering from breaking water waves using an impedance boundary MM\\/GTD approach  

Microsoft Academic Search

The radar backscattering from water waves of various degrees of breaking Is numerically examined. A hybrid moment method geometrical theory of diffraction (MM\\/GTD) technique previously used for small-grazing scattering from perfectly conducting surfaces is reformulated using impedance boundary conditions, allowing the treatment of large (but finite) conductivity scattering media such as sea water. This hybrid MM\\/GTD approach avoids the artificial

James C. West; J. Michael Sturm; S.-J. Ja

1998-01-01

271

A turn-up in pulsar spectra at mm-wavelengths?  

Microsoft Academic Search

We present the results of recent pulsar observations at frequencies between 27.9GHz and 34.8GHz, i.e. in a wavelength range of lambda10.75mm to lambda8.61mm, made with the Effelsberg radiotelescope. The measured flux densities of two out of eight detected pulsars suggest that the spectrum flattens out at high frequencies or even shows a turn-up. Moreover, we report variations in the measured

M. Kramer; K. M. Xilouris; A. Jessner; R. Wielebinski; M. Timofeev

1996-01-01

272

Fixation of mandibular fractures with 2.0-mm miniplates: Review of 191 cases  

Microsoft Academic Search

Purpose: Our goal was to study the use of 2.0-mm miniplates for the fixation of mandibular fractures. Patients and Methods: Records of 191 patients who experienced a total of 280 mandibular fractures that were treated with 2.0-mm miniplates were reviewed. One hundred twelve of those patients, presenting 160 fractures, who attended a late follow-up were also clinically evaluated. Miniplates were

Marisa Aparecida Cabrini Gabrielli; Elcio Marcantonio; Eduardo Hochuli-Vieira

2003-01-01

273

Rex: A randomized EXclusive region based scheduling scheme for mmWave WPANs with directional antenna  

Microsoft Academic Search

Millimeter-wave (mmWave) transmissions are promising technologies for high data rate (multi-Gbps) Wireless Personal Area Networks (WPANs). In this paper, we first introduce the concept of exclusive region (ER) to allow concurrent transmissions to explore the spatial multiplexing gain of wireless networks. Considering the unique characteristics of mmWave communications and the use of omni-directional or directional antennae, we derive the ER

Lin X. Cai; Xuemin Shen; Jon W. Mark

2010-01-01

274

On the cross-correlation of sub-mm sources and optically-selected galaxies  

E-print Network

Bright sub-mm galaxies are expected to arise in massive highly-biased haloes, and hence exhibit strong clustering. We argue that a valuable tool for measuring these clustering properties is the cross-correlation of sub-mm galaxies with faint optically-selected sources. We analyze populations of SCUBA-detected and optical galaxies in the GOODS-N survey area. Using optical/IR photometric-redshift information, we search for correlations induced by two separate effects: (1) cosmic magnification of background sub-mm sources by foreground dark matter haloes traced by optical galaxies at lower redshifts; and (2) galaxy clustering due to sub-mm and optical sources tracing the same population of haloes where their redshift distributions overlap. Regarding cosmic magnification, we find no detectable correlation. Our null result is consistent with a theoretical model for the cosmic magnification, and we show that a dramatic increase in the number of sub-mm sources will be required to measure the effect reliably. Regarding clustering, we find evidence at the 3.5-sigma level for a cross-correlation between sub-mm and optical galaxies analyzed in identical photometric redshift slices. The data hint that the sub-mm sources have an enhanced bias parameter compared to the optically-selected population (with a significance of 2-sigma). The next generation of deep sub-mm surveys can potentially perform an accurate measurement of each of these cross-correlations, adding a new set of diagnostics for understanding the development of massive structure in the Universe.

Chris Blake; Alexandra Pope; Douglas Scott; Bahram Mobasher

2006-02-20

275

Optical design and evaluation of a 4 mm cost-effective ultra-high-definition arthroscope  

PubMed Central

High definition and magnification rigid endoscope plays an important role in modern minimally invasive medical surgery and diagnosis. In this paper, we present the design and evaluation methods of a high definition rigid endoscope, specifically an arthroscope, with a large depth of field (DOF). The incident heights and exit angles of the sampled rays on the relay lens are controlled during the optimization process to ensure an effective field view (70°) and a normal ray path within the limited lens diameter of 2.7 mm. The lens is set up as a multi-configuration system with two extreme and one middle object distances to cover a large DOF. As a result, an entrance pupil of 0.3 mm is achieved for the first time, to bring the theoretical resolution to 23.1 lps/mm in the object space at a working distance of 20 mm, with the wavelength of 0.532 um. The modulation transfer function (MTF) curves approach diffraction limit, and the values are all higher than 0.3 at 160 line pairs/mm (lps/mm) in the image space. Meanwhile, stray light caused by total internal reflection on the inner wall of the rod lenses and the objective lens is eliminated. The measured resolution in the object space at a 20 mm working distance is 22.3 lps/mm, and test results show that other performance characteristics also fulfill design requirements. The relay lenses are designed with only one type of the spacer and two types of lenses to greatly reduce the fabrication and assembly cost. The design method has important research and application values for lens systems used in modern minimally invasive medical surgery and industrial non-destructive testing area. PMID:25136495

Cheng, Dewen; Wang, Yongtian; Yu, Lu; Liu, Xiaohua

2014-01-01

276

The MM2-cortical form of sporadic Creutzfeldt-Jakob disease presenting with visual disturbance.  

PubMed

A subclass of sporadic Creutzfeldt-Jakob disease (sCJD) characterized by onset with visual symptoms (Heidenhain variant) has been reported to belong to the MM1 or MV1 type according to Parchi's classification. The authors report a 65-year-old woman with MM2-cortical sCJD with slowly progressive visual disturbance as the initial symptom. Diffusion-weighted MRIs revealed hyperintensity in both occipital cortices at an early stage. PMID:16894125

Nozaki, I; Hamaguchi, T; Noguchi-Shinohara, M; Ono, K; Shirasaki, H; Komai, K; Kitamoto, T; Yamada, M

2006-08-01

277

[Sequence-specific interaction of pyrimidine oligonucleotides with double-stranded DNA at acidic pH complexes of different types].  

PubMed

The interaction of pyrimidine oligonucleotides (OLN(15) and OLN(6)) and their alkylating derivatives bearing 4-(3-amino)-N-methyl and N-2-chloroethyl (RCl) aniline residues at the 5'-phosphate with a fragment of the human gamma-interferon gene was studied. In the presence of 150 mM NaCl at pH 5.4, the yield of dsDNA alkylation was 60% for RCl-OLN(15) and 10% for RCl-OLN(6); at pH 4.0 in the presence of 150 mM NaCl and 10 mM MgCl2, the yield of the dsDNA modification product was 100% for RCl-OLN(6) and 50% for RCl-OLN(15). It was shown by native electrophoresis that OLN(15) could form with the target dsDNA complexes of two types in the presence of magnesium ions at pH 4.0. One of the complexes was stable at pH 5.4 in the presence of magnesium ions, whereas the other was not. We found that only the complex stable in 10 mM Mg(OAc)2, pH 5.4, was effectively alkylated. PMID:19915644

Brossalina, E B; Demchenko, E N; Demchenko, Iu N; Vlassov, V V

2009-01-01

278

Barium recovery by crystallization in a fluidized-bed reactor: effects of pH, Ba/P molar ratio and seed.  

PubMed

The effects of process conditions, including upward velocity inside the column, the amount of added seed and seed size, the pH value of the precipitant or the phosphate stream and the Ba/P molar ratio in a fluidized-bed reactor (FBR) were studied with a view to producing BaHPO? crystals of significant size and maximize the removal of barium. XRD were used to identify the products that were collected from the FBR. Experimental results show that an upward velocity of 48 cmmin(-1) produced the largest BaHPO? crystals with a size of around 0.84-1.0mm. The addition of seed crystals has no effect on barium removal. The use of a seed of a size in the ranges unseeded<0.149-0.29 mm<0.149 mm<0.29-0.42 mm produced increasing amounts of increasingly large crystals. The largest BaHPO? crystals were obtained at pH 8.4-8.8 with a Ba/P molar ratio of 1.0. In the homogeneous and heterogeneous processes, around 98% of barium was removed at pH 8.4-8.6 and [Ba]/[P]=1.0. The XRD results show that a significant amount of barium phosphate (Ba?(PO?)?) was obtained at pH 11. The compounds BaHPO? and BaO were present at a pH of below 10. PMID:24462085

Su, Chia-Chi; Reano, Resmond L; Dalida, Maria Lourdes P; Lu, Ming-Chun

2014-06-01

279

Nomograms for the Interdependence of Po2, So2, Pco2, Cco2 and pH in Human Blood at 28 and 32 °C  

Microsoft Academic Search

The O2 affinity and the Pco2-pH dependence were studied in blood samples from 20 healthy subjects at temperatures of 28 and 32 °C. The O2 dissociation curves were determined at various CO2 pressures (Pco2 = 30, 40 and 50 mmHg); the Pco2-pH dependence was determined at various So2 degrees. Comparison of the determined O2 dissociation curves with results obtained at

J. Grote; G. Thews; W.-D. Wünscher

1972-01-01

280

Effect of initial solution pH on the degradation of Orange II using clay-based Fe nanocomposites as heterogeneous photo-Fenton catalyst.  

PubMed

Effect of initial solution pH on the discoloration and mineralization of 0.2 mM Orange II by using two clay-based Fe nanocomposites (Fe-B (Fe supported on bentonite clay) and Fe-Lap-RD (Fe supported on laponite clay)) as catalysts was studied in detail. It was found that the initial solution pH not only influences the photo-catalytic activity of Fe-B and Fe-Lap-RD but also the Fe leaching from the two catalysts. Both catalysts show the best photo-catalytic activity at an initial solution pH of 3.0, and the activity of the catalysts decreases as the initial solution pH increases. At optimal conditions, 100% discoloration and mineralization of 0.2 mM Orange II are achieved in 60 and 120 min reaction in the presence of 10 mM H2O2, 1.0 g/L Fe-B, and 1 x 8 W UVC at initial solution pH of 3.0. 100% discoloration and 90% mineralization of 0.2 mM Orange II are achieved when Fe-Lap-RD is used as catalyst under the same conditions. Both catalysts also display a reasonable good photo-catalytic activity and negligible Fe leaching at an initial solution pH of 6.6 that is very close to neutral pH. This characteristic makes it possible for the Fe-B and Fe-Lap-RD to have a long-term stability. It also becomes feasible for the photo-Fenton process to treat the original wastewater without the need to pre-adjust the solution pH. PMID:16448683

Feng, Jiyun; Hu, Xijun; Yue, Po Lock

2006-02-01

281

Na(+)-HCO3- symport modulates intracellular pH in alveolar epithelial cells.  

PubMed

We investigated Na(+)-HCO3- cotransport as a mechanism for regulation of intracellular pH (pHi) in rat alveolar pneumocytes grown in primary culture. pHi was monitored using the fluorescent pH-sensitive dye 2',7'-bis(2-carboxyethyl)-5(6)-carboxyfluorescein (BCECF). Cells incubated in 6 mM N-2-hydroxyethylpiperazine-N'-2-ethanesulfonic acid (HEPES) medium at pH 7.4 were subjected to rapid acidification by CO2 pulse. pHi recovered in the presence of Na+ with an initial rate (dpHi/dt) of 0.15 min-1, which was reduced by 67% when Na+ was replaced by choline, unaffected by substitution of gluconate for Cl-, reduced 40% in the presence of 4,4'-diisothiocyanostilbene-2,2'-disulfonic acid (DIDS, 500 microM), and unchanged by amiloride (1 mM). In parallel experiments, cells were incubated at pH 7.4 with 20 mM HCO3- and pHi acutely lowered by NH3 prepulse. dpHi/dt in these experiments was 0.14 min-1 in the presence of Na+ and HCO3-, and reduced 79% under Na(+)-free conditions. These data indicate the presence of a Na(+)-dependent, Cl(-)-independent, DIDS-sensitive and amiloride-insensitive mechanism of recovery from acute intracellular acidification in alveolar pneumocytes, most consistent with Na(+)-HCO3- cotransport (symport) effecting acid extrusion under these experimental conditions. This ion transport mechanism may contribute to regulation of pHi in alveolar pneumocytes, transepithelial transport of acid-base equivalents across the alveolar epithelium, and modulation of pH of alveolar fluid in adult mammalian lungs. PMID:2058696

Lubman, R L; Crandall, E D

1991-06-01

282

PP HH YY SS II CC AA LL PP RR OO PP EE RR TT YY MM EE AA SS UU RR EE MM EE NN TT SS YY SS TT EE MM Q u a n t u m D e s i g n  

E-print Network

PP HH YY SS II CC AA LL PP RR OO PP EE RR TT YY MM EE AA SS UU RR EE MM EE NN TT SS YY SS TT EE MM Sample puck "Keyed" bottom connector SS YY SS TT EE MM FF EE AA TT UU RR EE SS 1 Much of the versatility

Liu, J. Ping

283

Isolation of a keratinolytic proteinase from Trichophyton mentagrophytes with enzymatic activity at acidic pH.  

PubMed Central

A keratinolytic proteinase with enzyme activity at acidic pH was isolated from culture filtrates of Trichophyton mentagrophytes, a major pathogenic fungus of dermatophytosis. The molecular weight of the proteinase was estimated to be 41,000 by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and 38,000 by gel filtration. The isoelectric point was determined to be 3.9. The proteinase had a pH optimum of 4.5 for keratin and 5.5 for hemoglobin. This enzyme hydrolyzed the synthetic chymotrypsin substrate Suc-Ala-Ala-Pro-Phe-MCA (Km, 0.59 mM), and its activity was strongly inhibited by chymostatin. Previously reported proteinases from dermatophytes have had enzyme activities in neutral or alkaline pH; however, healthy skin has a weakly acidic pH. Thus, the purified proteinase which has an optimal activity at acidic pH and hydrolyzes skin constituents could be an important virulence factor in dermatophytosis. Images PMID:2478474

Tsuboi, R; Ko, I; Takamori, K; Ogawa, H

1989-01-01

284

Anion Conductance of Frog Muscle Membranes: One Channel, Two Kinds of pH Dependence  

PubMed Central

Anion conductance and permeability sequences were obtained for frog skeletal muscle membranes from the changes in characteristic resistance and transmembrane potential after the replacement of one anion by another in the bathing solution. Permeability and conductance sequences are the same. The conductance sequence at pH = 7.4 is Cl- Br- > NO3- > I- > trichloroacetate ? benzoate > valerate > butyrate > proprionate > formate > acetate ? lactate > benzenesulfonate ? isethionate > methylsulfonate > glutamate ? cysteate. The anions are divided into two classes: (a) Chloride-like anions (Cl- through trichloroacetate) have membrane conductances that decrease as pH decreases. The last six members of the complete sequence are also chloride like. (b) Benzoate-like anions (benzoate through acetate) have conductances that increase as pH decreases. At pH = 6.7 zinc ions block Cl- and benzoate conductances with inhibitory dissociation constants of 0.12 and 0.16 mM, respectively. Chloride-like and benzoate-like anions probably use the same channels. The minimum size of the channel aperture is estimated as 5.5 x 6.5 Å from the dimensions of the largest permeating anions. A simple model of the channel qualitatively explains chloride-like and benzoate-like conductance sequences and their dependence on pH. PMID:4542368

Woodbury, J. W.; Miles, P. R.

1973-01-01

285

Influence of Acidic pH on Hydrogen and Acetate Production by an Electrosynthetic Microbiome  

PubMed Central

Production of hydrogen and organic compounds by an electrosynthetic microbiome using electrodes and carbon dioxide as sole electron donor and carbon source, respectively, was examined after exposure to acidic pH (?5). Hydrogen production by biocathodes poised at ?600 mV vs. SHE increased>100-fold and acetate production ceased at acidic pH, but ?5–15 mM (catholyte volume)/day acetate and>1,000 mM/day hydrogen were attained at pH ?6.5 following repeated exposure to acidic pH. Cyclic voltammetry revealed a 250 mV decrease in hydrogen overpotential and a maximum current density of 12.2 mA/cm2 at ?765 mV (0.065 mA/cm2 sterile control at ?800 mV) by the Acetobacterium-dominated community. Supplying ?800 mV to the microbiome after repeated exposure to acidic pH resulted in up to 2.6 kg/m3/day hydrogen (?2.6 gallons gasoline equivalent), 0.7 kg/m3/day formate, and 3.1 kg/m3/day acetate (?=?4.7 kg CO2 captured). PMID:25333313

LaBelle, Edward V.; Marshall, Christopher W.; Gilbert, Jack A.; May, Harold D.

2014-01-01

286

Algal and Bacterial Activities in Acidic (pH 3) Strip Mine Lakes  

PubMed Central

Reservoir 29 and Lake B are extremely acid lakes (epilimnion pHs of 2.7 and 3.2, respectively), because they receive acidic discharges from coal refuse piles. They differ in that the pH of profundal sediments in Reservoir 29 increased from 2.7 to 3.8 during the period of thermal stratification, whereas permanently anoxic sediments in Lake B had a pH of 6.2. The pH rise in Reservoir 29 sediments was correlated with a temporal increase in H2S concentration in the anaerobic hypolimnion from 0 to >1 mM. The chlorophyll a levels in the epilimnion of Reservoir 29 were low, and the rate of primary production was typical of an oligotrophic system. However, there was a dense 10-cm layer of algal biomass at the bottom of the metalimnion. Production by this layer was low owing to light limitation and possibly H2S toxicity. The specific photosynthetic rates of epilimnetic algae were low, which suggests that nutrient availability is more important than pH in limiting production. The highest photosynthetic rates were obtained in water samples incubated at pH 2.7 to 4. Heterotrophic bacterial activity (measured by [14C]glucose metabolism) was greatest at the sediment/water interface. Bacterial production (assayed by thymidine incorporation) was as high in Reservoir 29 as in a nonacid mesotrophic Indiana lake. PMID:16347430

Gyure, Ruth A.; Konopka, Allan; Brooks, Austin; Doemel, William

1987-01-01

287

The Effect of Acidic pH on Microleakage of Mineral Trioxide Aggregate and Calcium-Enriched Mixture Apical Plugs  

PubMed Central

Introduction: The purpose of this laboratory study was to evaluate the effect of acidic pH on the sealing ability of calcium-enriched mixture (CEM) cement and mineral trioxide aggregate (MTA) apical plugs. Methods and Materials: Seventy single-rooted human maxillary anterior teeth were recruited. The teeth were randomly divided into 4 experimental groups (n=15), and 1 negative and 1 positive control groups of 5. The root canals were cleaned and shaped and the terminal 3 mm of the roots were resected. Then MTA and CEM cement plugs were condensed in apical region with 3 mm thicknesses. The samples were exposed to pH values of 5.5 and 7.4. Leakage was evaluated by the fluid filtration technique at 1, 7, 14, 30 day intervals. Data were analyzed by the repeated measures MANOVA, one-way ANOVA and MANOVA/Bonferroni test. Results: Acidic pH significantly reduced the sealing ability of MTA after 1, 14 and 30 days (P<0.05). The rate of microleakage in CEM cement samples in acidic pH was significantly greater than that in neutral pH in day 30 (P<0.05). There was no significant difference between the sealing property of MTA and CEM cement at both pH levels (P>0.05). Conclusion: It can be concluded that the CEM cement exhibited similar sealing ability as MTA at both pH levels. In addition, an acidic pH environment reduced the sealing ability of MTA and CEM cement after 30 days. PMID:25386205

Mirhadi, Hossein; Moazzami, Fariborz; Safarzade, Sareh

2014-01-01

288

Existing Facility (Ph I) Includes Water intake, screens,  

E-print Network

#12;#12;#12;Existing Facility (Ph I) Includes Water intake, screens, and pumps sufficient for proposed Ph II #12;Existing Facility (Ph I) Includes Ozone water treatment and settling pond sufficient for proposed Ph II #12;Location of proposed Ph II Facilities #12;WW Hatchery Program Current vs. WW Hatchery

289

Metabolism and disposition of MM-433593, a selective FAAH-1 inhibitor, in monkeys  

PubMed Central

MM-433593 is a highly potent and selective inhibitor of fatty acid amide hydrolase-1 (FAAH-1) with potential utility as an orally administered treatment of pain, inflammation, and other disorders. In this study, we investigated the metabolism and pharmacokinetics of MM-433593 in monkeys, and compared plasma and urine metabolites of this compound to the in vitro metabolites produced by monkey hepatocytes. Intravenous administration of MM-433593 to cynomolgus monkeys produced a rapid distribution phase and slower elimination phase with a mean systemic clearance rate of 8–11 mL/min/kg. Absolute oral bioavailability was determined to be 14–21% with maximum plasma concentrations reached ?3 h (Tmax) following a 10 mg/kg oral dose. The average terminal half-life of MM-433593 was 17–20 h, and there were no qualitative sex differences in the metabolite profile of MM-433593. The major site of metabolism was oxidation of the methyl group at the five position of the indole ring, which was confirmed by chromatography and mass spectrometry comparison to a synthesized authentic standard. This metabolite was further oxidized to the corresponding carboxylic acid and/or conjugated with sulfate, glucuronide, or glutathione. In all, 18 metabolites were found in plasma and urine. In vitro incubations of MM-433593 with monkey hepatocytes yielded 13 metabolites, all of which were found in vivo, indicating a good correlation between the in vitro and in vivo metabolism data. A comprehensive pathway for the metabolism of MM-433593 is proposed, including a plausible, five-step biotransformation for the formation of N-acetylcysteine conjugate metabolite (M18) from the hydroxylated parent (M5). PMID:25505606

Banijamali, Ali R; Wakefield, James D; Mermerian, Ara H; Busby, Robert W

2014-01-01

290

NhaP1 is a K+(Na+)/H+ antiporter required for growth and internal pH homeostasis of Vibrio cholerae at low extracellular pH  

PubMed Central

Vibrio cholerae has adapted to a wide range of salinity, pH and osmotic conditions, enabling it to survive passage through the host and persist in the environment. Among the many proteins responsible for bacterial survival under these diverse conditions, we have identified Vc-NhaP1 as a K+(Na+)/H+ antiporter essential for V. cholerae growth at low environmental pH. Deletion of the V. cholerae nhaP1 gene caused growth inhibition when external potassium was either limited (100 mM and below) or in excess (400 mM and above). This growth defect was most apparent at mid-exponential phase, after 4–6 h of culture. Using a pH-sensitive GFP, cytosolic pH was shown to be dependent on K+ in acidic external conditions in a Vc-NhaP1-dependent manner. When functionally expressed in an antiporterless Escherichia coli strain and assayed in everted membrane vesicles, Vc-NhaP1 operated as an electroneutral alkali cation/proton antiporter, exchanging K+ or Na+ ions for H+ within a broad pH range (7.25–9.0). These data establish the putative V. cholerae NhaP1 protein as a functional K+(Na+)/H+ antiporter of the CPA1 family that is required for bacterial pH homeostasis and growth in an acidic environment. PMID:22241048

Quinn, Matthew J.; Resch, Craig T.; Sun, Jonathan; Lind, Erin J.

2012-01-01

291

QM/MM Minimum Free Energy Path: Methodology and Application to Triosephosphate Isomerase  

PubMed Central

Structural and energetic changes are two important characteristic properties of a chemical reaction process. In the condensed phase, studying these two properties is very challenging because of the great computational cost associated with the quantum mechanical calculations and phase space sampling. Although the combined quantum mechanics/molecular mechanics (QM/MM) approach significantly reduces the amount of the quantum mechanical calculations and facilitates the simulation of solution phase and enzyme catalyzed reactions, the required quantum mechanical calculations remain quite expensive and extensive sampling can be achieved routinely only with semiempirical quantum mechanical methods. QM/MM simulations with ab initio QM methods, therefore, are often restricted to narrow regions of the potential energy surface such as the reactant, product and transition state, or the minimum energy path. Such ab initio QM/MM calculations have previously been performed with the QM/MM-Free Energy (QM/MM-FE) method of Zhang et al.1 to generate the free energy profile along the reaction coordinate using free energy perturbation calculations at fixed structures of the QM subsystems. Results obtained with the QM/MM-FE method depend on the determination of the minimum energy reaction path, which is based on local conformations of the protein/solvent environment and can be difficult to obtain in practice. To overcome the difficulties associated with the QM/MM-FE method and to further enhance the sampling of the MM environment conformations, we develop here a new method to determine the QM/MM minimum free energy path (QM/MM-MFEP) for chemical reaction processes in solution and in enzymes. Within the QM/MM framework, we express the free energy of the system as a function of the QM conformation, thus leading to a simplified potential of mean force (PMF) description for the thermodynamics of the system. The free energy difference between two QM conformations is evaluated by the QM/MM free energy perturbation method. The free energy gradients with respect to the QM degrees of freedom are calculated from molecular dynamics simulations at given QM conformations. With the free energy and free energy gradients in hand, we further implement chain-of-conformation optimization algorithms in the search for the reaction path on the free energy surface without specifying a reaction coordinate. This method thus efficiently provides a unique minimum free energy path for solution and enzyme reactions, with structural and energetic properties being determined simultaneously. To further incorporate the dynamic contributions of the QM subsystem into the simulations, we develop the reaction path potential of Lu, et al.2 for the minimum free energy path. The combination of the methods developed here presents a comprehensive and accurate treatment for the simulation of reaction processes in solution and in enzymes with ab initio QM/MM methods. The method has been demonstrated on the first step of the reaction of the enzyme triosephosphate isomerase with good agreement with previous studies. PMID:19079734

Hu, Hao; Lu, Zhenyu; Yang, Weitao

2008-01-01

292

Administration Noma Bennett Anderson, PhD  

E-print Network

Kenwright, MS, MT(ASCP)SI, MB Cytotechnology, Histotechnology and Graduate Program Director Barbara DuBray-Benstein, PhD Medical Laboratory Science Program Director Kathleen Kenwright, MS, MT(ASCP)SI, MB Department

Cui, Yan

293

Aryan Hazeghi PhD candidate  

E-print Network

: Prof. Yoshio Nishi Ranked 5/143 applicants in the PhD qualification exam Non-volatile Memory Technology current and future equipment and process needs Member of the Stanford Students Environmental Consulting

Nishi, Yoshio

294

Mary Fennell, PhD Chair  

Cancer.gov

NCI Community Cancer Centers Program Evaluation Oversight Committee Roster CHAIR Mary Fennell, Ph.D. Chair, Department of Sociology and Community Health Brown University Box 1916, 211 Maxcy Hall 112 George Street Providence, RI 02912

295

Fetal scalp pH testing  

MedlinePLUS

Sometimes fetal heart monitoring doesn't provide enough information about the well-being of a baby. In these cases, testing the scalp pH can help the doctor decide whether the fetus is getting enough oxygen ...

296

Paul Pinsky, PhD, MPH  

Cancer.gov

Division of Cancer Prevention Staff Paul Pinsky, PhD, MPH Acting ChiefEarly Detection Research Group Location Division of Cancer PreventionNational Cancer Institute9609 Medical Center Drive, Room 5E444 Rockville, MD 20850 Phone

297

Colorimetric Determination of pH.  

ERIC Educational Resources Information Center

Presented is an activity in which the pH of a solution can be quantitatively measured using a spectrophotometer. The theory, experimental details, sample preparation and selection, instrumentation, and results are discussed. (CW)

Tucker, Sheryl; And Others

1989-01-01

298

Multiple pH Levels in Chromatograms  

Microsoft Academic Search

Lines of buffer solutions drawn longitudinally on chromatograms with a capillary pipette provide different levels of pH which affect the Rf values, color, fluorescence, and other properties of the chromatographed substances.

A. A. Bitancourt; Alexandra P. Nogueira

1959-01-01

299

Development and application of QM/MM methods to study the solvation effects and surfaces  

SciTech Connect

Quantum mechanical (QM) calculations have the advantage of attaining high-level accuracy, however QM calculations become computationally inefficient as the size of the system grows. Solving complex molecular problems on large systems and ensembles by using quantum mechanics still poses a challenge in terms of the computational cost. Methods that are based on classical mechanics are an inexpensive alternative, but they lack accuracy. A good trade off between accuracy and efficiency is achieved by combining QM methods with molecular mechanics (MM) methods to use the robustness of the QM methods in terms of accuracy and the MM methods to minimize the computational cost. Two types of QM combined with MM (QM/MM) methods are the main focus of the present dissertation: the application and development of QM/MM methods for solvation studies and reactions on the Si(100) surface. The solvation studies were performed using a discreet solvation model that is largely based on first principles called the effective fragment potential method (EFP). The main idea of combining the EFP method with quantum mechanics is to accurately treat the solute-solvent and solvent-solvent interactions, such as electrostatic, polarization, dispersion and charge transfer, that are important in correctly calculating solvent effects on systems of interest. A second QM/MM method called SIMOMM (surface integrated molecular orbital molecular mechanics) is a hybrid QM/MM embedded cluster model that mimics the real surface.3 This method was employed to calculate the potential energy surfaces for reactions of atomic O on the Si(100) surface. The hybrid QM/MM method is a computationally inexpensive approach for studying reactions on larger surfaces in a reasonably accurate and efficient manner. This thesis is comprised of four chapters: Chapter 1 describes the general overview and motivation of the dissertation and gives a broad background of the computational methods that have been employed in this work. Chapter 2 illustrates the methodology of the interface of the EFP method with the configuration interaction with single excitations (CIS) method to study solvent effects in excited states. Chapter 3 discusses the study of the adiabatic electron affinity of the hydroxyl radical in aqueous solution and in micro-solvated clusters using a QM/EFP method. Chapter 4 describes the study of etching and diffusion of oxygen atom on a reconstructed Si(100)-2 x 1 surface using a hybrid QM/MM embedded cluster model (SIMOMM). Chapter 4 elucidates the application of the EFP method towards the understanding of the aqueous ionization potential of Na atom. Finally, a general conclusion of this dissertation work and prospective future direction are presented in Chapter 6.

Dibya, Pooja Arora

2010-05-16

300

Reaction Path Reaction path potential for complex biomolecular systems derived from mixed QM/MM methods  

NASA Astrophysics Data System (ADS)

The reaction path potential (RPP) follows the ideas from the reaction path Hamiltonian of Miller, Handy and Adams for gas phase reactions but is designed specifically for large systems described with QM/MM methods. RPP is an analytical energy expression of the combined QM/MM potential energy along the minimum energy path (J. Chem. Phys. 121, 89, 2004). An expansion around the minimum energy path is made in both the nuclear and the electronic degrees of freedom for the QM subsystem, while the interaction between the QM and MM subsystems is described as the interaction of the MM charges with polarizable QM charges. The input data for constructing the reaction path potential are energies, frequencies and electron density response properties of the QM subsystem. RPP provides a potential energy surface for rigorous statistical mechanics and mixed quantum/classical reaction dynamics calculations of complex systems, as will be shown for several enzymes. Recent further development in determining QM/MM free energy reaction paths will also be presented.

Yang, Weitao

2006-03-01

301

Manufacture and Metrology of 300 mm Silicon Wafers with Ultra-Low Thickness Variation  

NASA Astrophysics Data System (ADS)

With the evolution of exposure tools for optical lithography towards larger numerical apertures, the semiconductor industry expects continued demand for improved wafer flatness at the exposure site. The allowable site flatness for 300 mm wafers is expected to be less than 45 nm by 2010 and it may be as low as 25 nm by 2015 according to the International Technology Roadmap for Semiconductors (ITRS 2006). This requires wafers with low thickness variation and presents a challenge for both wafer polishing and metrology tools, which must be capable of meeting the specifications. We report the results of fabricating 300 mm silicon wafers with very low thickness variation using magnetorheological finishing (MRF), a deterministic subaperture finishing process. The wafer thickness metrology, which guided the finishing process, was provided by an infrared interferometer developed at the National Institute of Standards and Technology (NIST). The finishing method in combination with the interferometric wafer metrology enabled the fabrication of 300 mm silicon wafers with a total thickness variation (TTV) of about 40 nm, and between 10 nm and 15 nm thickness variation at 25 mm×25 mm exposure sites.

Griesmann, Ulf; Wang, Quandou; Tricard, Marc; Dumas, Paul; Hall, Christopher

2007-09-01

302

450 mm dual frequency capacitively coupled plasma sources: Conventional, graded, and segmented electrodes  

SciTech Connect

Wafer diameters for microelectronics fabrication will soon transition from 300 to 450 mm at a time when excitation frequencies for capacitively coupled plasmas (CCPs) are increasing to 200 MHz or higher. Already for 300 mm tools, there is evidence that wave behavior (i.e., propagation, constructive, and destructive interference) affects the uniformity of processing. The increase in diameter to 450 mm is likely to exacerbate these effects, perhaps requiring nontraditional tool designs. This is particularly important in dual frequency (DF) CCP tools in which there are potential interactions between frequencies. In this paper, results from a two-dimensional computational investigation of Ar plasma properties in a 450 mm DF-CCP reactor, incorporating a full-wave solution of Maxwell's equations, are discussed. As in 300 mm DF-CCP reactors, the electron density collapses toward the center of the reactor with increasing high frequency (HF), however, with more pronounced finite wavelength effects. Graded conductivity electrodes with multilayer of dielectrics are computationally demonstrated as a possible means to suppress wave effects thereby increasing plasma uniformity. Segmentation of the HF electrode also improves the plasma uniformity by making the electrical distance between the feeds and the sheath edges as uniform as possible.

Yang Yang [Department of Electrical and Computer Engineering, Iowa State University, Ames, Iowa 50011 (United States); Kushner, Mark J. [Department of Electrical Engineering and Computer Science, University of Michigan, 1301 Beal Avenue, Ann Arbor, Michigan 48109-2122 (United States)

2010-12-01

303

Survival and growth of age-0 steelhead after surgical implantation of 23-mm passive integrated transponders  

USGS Publications Warehouse

Little information is available on the effects of implanting 23-mm passive integrated transponder (PIT) tags in salmonids less than 90 mm fork length (FL). Using juvenile steelhead Oncorhynchus mykiss (range, 73-97 mm FL), we compared instantaneous growth rates and survival among three experimental groups: control, surgery with no tag, and surgery with tag. Survival rate was lower for tagged fish (86%) than for control and surgery-no tag fish (virtually 100% in each group). Approximately 90% of the mortalities occurred during days 1-3. Growth rate for the tagged group was lower for the first two 10-d measurement intervals; however, during the third 10-d interval, growth rates for tagged fish equaled or exceeded values for the other groups. These results suggest that tagged fish recovered by day 20. Growth rates for the control and surgery-no tag groups did not differ from one another during any measurement interval. Tag retention rate was 97% over the 30-d period of the study. It appears that the combination of fish length and tag size in this study resulted in short-term negative effects on growth rate and survival; however, 23-mm PIT tags may still be useful for studies of salmonids 80-90 mm FL when survival is not the parameter of interest. ?? Copyright by the American Fisheries Society 2006.

Bateman, D.S.; Gresswell, R.E.

2006-01-01

304

Measurement of soil pH  

Microsoft Academic Search

A number of experimental results are presented which show the variation of the pH values of several soils when samples of each are shaken with CaClâ solutions of different concentrations. These results are then interpreted on the basis of the ratio law-derived from the Gouy theory of the electrical double layer - and it is shown that the pH values

R. K. Schofield; A. Wormald Taylor

1955-01-01

305

Articles Student Understanding of pH \\  

Microsoft Academic Search

In foundation biochemistry and biological chemistry courses, a major problem area that has been identified is students' lack of understanding of pH, acids, bases, and buffers and their inability to apply their knowledge in solving acid\\/base problems. The aim of this study was to explore students' conceptions of pH and their ability to solve problems associated with the behavior of

Dianne J. Watters; James J. Watters

306

Ambulatory Esophageal pH Monitoring  

Microsoft Academic Search

Extraesophageal manifestations of gastroesophageal reflux may be best diagnosed using ambulatory esophageal pH monitoring. This test involves the placemenmt of a thin pH probe in the esophagus, which is connected to a small box on a waistbelt. Studies are done in an ambulatory state in the patient’s home and work environment. Data collected assesses acid exposure time over the circadian

Joel E Richter

1997-01-01

307

Effect of two mouthwashes on salivary ph.  

PubMed

To analyze the effect of two mouthwashes on salivary pH and correlate it with age, buffer capacity and saliva flow rate in healthy volunteers, a crossover phase IV clinical study involving three age-based groups was designed. Two commercial mouthwashes (MW), Cool Mint ListerineR (MWa) and Periobacter R (MWb) were used. The unstimulated saliva of each individual was first characterized by measuring flow rate, pH, and buffer capacity. Salivary pH was evaluated before rinsing with a given MW, immediately after rinsing, 5 minutes later, and then every 10 min (at 15, 25, 35 min) until the baseline pH was recovered. Paired t-test, ANOVA with a randomized block design, and Pearson correlation tests were used. Averages were 0.63 mL/min, 7.06, and 0.87 for flow rate, pH, and buffer capacity, respectively. An immediate significant increase in salivary pH was observed after rinsing, reaching average values of 7.24 (MWb) and 7.30 (MWa), which declined to an almost stable value 15 minutes. The great increase in salivary pH, after MW use shows that saliva is a dynamic system, and that the organism is capable of responding to a stimulus with changes in its composition. It is thus evident that pH of the external agent alone is not a good indicator for its erosive potential because biological systems tend to neutralize it. The results of this study enhance the importance of in vivo measurements and reinforce the concept of the protective action of saliva. PMID:25523957

Belardinelli, Paola A; Morelatto, Rosana A; Benavidez, Tomás E; Baruzzi, Ana M; López de Blanc, Silvia A

2014-01-01

308

Synergistic and antagonistic effects of salinity and pH on germination in switchgrass (Panicum virgatum L.).  

PubMed

The effects of salt-alkaline mixed stress on switchgrass were investigated by evaluating seed germination and the proline, malondialdehyde (MDA) and soluble sugar contents in three switchgrass (Panicum virgatum L.) cultivars in order to identify which can be successfully produced on marginal lands affected by salt-alkaline mixed stress. The experimental conditions consisted of four levels of salinity (10, 60, 110 and 160 mM) and four pH levels (7.1, 8.3, 9.5 and 10.7). The effects of salt-alkaline mixed stress with equivalent coupling of the salinity and pH level on the switchgrass were explored via model analyses. Switchgrass was capable of germinating and surviving well in all treatments under low-alkaline pH (pH?8.3), regardless of the salinity. However, seed germination and seedling growth were sharply reduced at higher pH values in conjunction with salinity. The salinity and pH had synergetic effects on the germination percentage, germination index, plumular length and the soluble sugar and proline contents in switchgrass. However, these two factors exhibited antagonistic effects on the radicular length of switchgrass. The combined effects of salinity and pH and the interactions between them should be considered when evaluating the strength of salt-alkaline mixed stress. PMID:24454834

Liu, Yuan; Wang, Quanzhen; Zhang, Yunwei; Cui, Jian; Chen, Guo; Xie, Bao; Wu, Chunhui; Liu, Haitao

2014-01-01

309

Synergistic and Antagonistic Effects of Salinity and pH on Germination in Switchgrass (Panicum virgatum L.)  

PubMed Central

The effects of salt-alkaline mixed stress on switchgrass were investigated by evaluating seed germination and the proline, malondialdehyde (MDA) and soluble sugar contents in three switchgrass (Panicum virgatum L.) cultivars in order to identify which can be successfully produced on marginal lands affected by salt-alkaline mixed stress. The experimental conditions consisted of four levels of salinity (10, 60, 110 and 160 mM) and four pH levels (7.1, 8.3, 9.5 and 10.7). The effects of salt-alkaline mixed stress with equivalent coupling of the salinity and pH level on the switchgrass were explored via model analyses. Switchgrass was capable of germinating and surviving well in all treatments under low-alkaline pH (pH?8.3), regardless of the salinity. However, seed germination and seedling growth were sharply reduced at higher pH values in conjunction with salinity. The salinity and pH had synergetic effects on the germination percentage, germination index, plumular length and the soluble sugar and proline contents in switchgrass. However, these two factors exhibited antagonistic effects on the radicular length of switchgrass. The combined effects of salinity and pH and the interactions between them should be considered when evaluating the strength of salt-alkaline mixed stress. PMID:24454834

Liu, Yuan; Wang, Quanzhen; Zhang, Yunwei; Cui, Jian; Chen, Guo; Xie, Bao; Wu, Chunhui; Liu, Haitao

2014-01-01

310

Effects of pH, Chloride, and Bicarbonate on Cu(I) Oxidation Kinetics at Circumneutral pH  

NASA Astrophysics Data System (ADS)

The redox chemistry of copper species in the upper water column plays a significant role in its speciation, transport and bioavailability. Most previous studies have focused primarily on Cu(II), principally because Cu(I) is easily oxidized to Cu(II) by oxygen or other oxidants. However, a growing body of evidence indicates that a number of potentially important reactions may lead to Cu(I) formation and result in a significant steady-state concentration of Cu(I) in natural waters. Redox reactions of Cu(I) could result in the production of reactive oxygen species (ROS), such as superoxide and hydroxyl radical, that may subsequently induce a cascade of radical-promoted reactions with other constituents in natural waters. As such, a better understanding of copper-catalysed processes that produce and consume O2- is important in furthering our insight into factors contributing to global biogeochemical cycles. In this study, the oxidation kinetics of nanomolar concentrations of Cu(I) in NaCl solutions have been investigated over the pH range 6.5-8.0.The overall apparent oxidation rate constant was strongly affected by chloride, moderately by bicarbonate and, and to a lesser extent, by pH. In the absence of bicarbonate, an equilibrium-based speciation model indicated that Cu+ and CuClOH- were the most kinetically reactive species, while the contribution of other Cu(I) species to the overall oxidation rate was minor. A kinetic model based on recognized key redox reactions for these two species further indicated that oxidation of Cu(I) by oxygen and superoxide were important reactions at all pH values and [Cl-] considered, but back reduction of Cu(II) by superoxide only became important at relatively low chloride concentrations. Bicarbonate concentrations from 2-5 mM substantially accelerated Cu(I) oxidation. Kinetic analysis over a range of bicarbonate concentrations revealed that this was due to the formation of CuCO3-, which reacts relatively rapidly with oxygen, and not due to inhibition of the back reduction of Cu(II) by formation of Cu(II)-carbonate complexes. We conclude that the simultaneous oxygenation of Cu+, CuClOH- and CuCO3- is the rate-limiting step in the overall oxidation of Cu(I) under these conditions. Determination of values for apparent and intrinsic rate constants for the oxidation of those critical Cu(I) species by O2 over the pH range 6.5-8.0 should greatly assist in understanding and predicting inorganic Cu(I) and Cu(II) transformations in natural waters.

Yuan, X.; Pham, A.; Waite, T.; Xing, G.; Rose, A.

2012-12-01

311

New Measurements of the Cosmic Background Radiation Temperature at3.3 mm Wavelength  

SciTech Connect

We have measured the temperature of the cosmic background radiation (CBR) at 3.3 mm wavelength in 1982, 1983, and 1984 as part of a larger project to determine the CBR temperature at five wavelengths from 12 cm to 3.3 mm (Smoot et al. 1985). The 3.3-mm measurements yield a brightness temperature of 2.57 K with a 1{sigma} uncertainty of 20.12 K. This paper describes the instrument, the measurement techniques, and the data-analysis procedures used. Our result is in good agreement with recent measurements at comparable wavelengths by Meyer and Jura (1985) and by Peterson, Richards, and Timusk (1985), but it disagrees with the temperatures reported by Woody and Richards (1981).

Witebsky, C.; Smoot, G.; De Amici, G.; Friedman, S.D.

1986-02-01

312

Large-Area Reflective Infrared Filters for Millimeter/Sub-mm Telescopes  

NASA Astrophysics Data System (ADS)

Ground-based millimeter and sub-millimeter telescopes are attempting to image the sky with ever-larger cryogenically-cooled bolometer arrays, but face challenges in mitigating the infrared loading accompanying large apertures. Absorptive infrared filters supported by mechanical coolers scale insufficiently with aperture size. Reflective metal-mesh filters placed behind the telescope window provide a scalable solution in principle, but have been limited by photolithography constraints to diameters under 300 mm. We present laser etching as an alternate technique to photolithography for fabrication of large-area reflective filters, and show results from lab tests of 500-mm-diameter filters. Filters with up to 700-mm diameter can be fabricated using laser etching with existing capability.

Ahmed, Z.; Grayson, J. A.; Thompson, K. L.; Kuo, C.-L.; Brooks, G.; Pothoven, T.

2014-09-01

313

An Application of QM/MM Simulation: The Second Protonation of Cytochrome P450.  

PubMed

The multiscale model strategy, hybrid quantum mechanics and molecular mechanics (QM/MM), has become more and more prevalent in the theoretical study of enzymatic reactions. It combines both the efficiency of the Newtonian molecular calculations and the accuracy of the quantum mechanical methods. Simulation using QM/MM multiscale model may be one of the most promising approaches that could further narrow the gap between the theoretical models and the real problems. It is capable of dealing with not only the conformational changes of biomacromolecules, but also the catalytic reactions. Herein, we reviewed some of our recent work to demonstrate the application of the QM/MM simulations in exploring the enzymatic reactions. PMID:25387972

Lian, Peng; Wei, Dongqing

2015-01-01

314

Recording and wear characteristics of 4 and 8 mm helical scan tapes  

NASA Technical Reports Server (NTRS)

Performance data of media on helical scan tape systems (4 and 8 mm) is presented and various types of media are compared. All measurements were performed on a standard MediaLogic model ML4500 Tape Evaluator System with a Flash Converter option for time based measurements. The 8 mm tapes are tested on an Exabyte 8200 drive and 4 mm tapes on an Archive Python drive; in both cases, the head transformer is directly connected to a Media Logic Read/Write circuit and test electronics. The drive functions only as a tape transport and its data recover circuits are not used. Signal to Noise, PW 50, Peak Shift and Wear Test data is used to compare the performance of MP (metal particle), BaFe, and metal evaporate (ME). ME tape is the clear winner in magnetic performance but its susceptibility to wear and corrosion, make it less than ideal for data storage.

Peter, Klaus J.; Speliotis, Dennis E.

1993-01-01

315

Investigation of optical transmittance and light response uniformity of 600-mm-long BGO crystals  

NASA Astrophysics Data System (ADS)

Optical transmittance and light response uniformity were investigated for 25 mm×25 mm×600 mm BGO crystals, the longest BGO single crystals reported so far. The long BGO crystals exhibit good optical transmittance within the wavelength range concerned and an overall energy resolution of 19.68% for 0.662 MeV ?-rays. The light response uniformity of one long BGO, SIC-BGO-125, was measured in the single-end or dual-end readout mode combined with different reflecting materials. It was suggested that the light response uniformity of the long rectangular BGO is primarily affected by internal absorption, the reflectivity of reflecting materials and the readout mode. The best uniformity of -1.4±0.8% can be achieved when the crystal is measured only from the tail end and wrapped with ESR. Reflecting materials of high reflectivity can significantly improve the light response uniformity, but further improvement is limited by the internal absorption of the crystal.

Ji, Zhiming; Ni, Haihong; Yuan, Lanying; Chen, Junfeng; Wang, Shaohua

2014-07-01

316

Recording and wear characteristics of 4 and 8 mm helical scan tapes  

NASA Astrophysics Data System (ADS)

Performance data of media on helical scan tape systems (4 and 8 mm) is presented and various types of media are compared. All measurements were performed on a standard MediaLogic model ML4500 Tape Evaluator System with a Flash Converter option for time based measurements. The 8 mm tapes are tested on an Exabyte 8200 drive and 4 mm tapes on an Archive Python drive; in both cases, the head transformer is directly connected to a Media Logic Read/Write circuit and test electronics. The drive functions only as a tape transport and its data recover circuits are not used. Signal to Noise, PW 50, Peak Shift and Wear Test data is used to compare the performance of MP (metal particle), BaFe, and metal evaporate (ME). ME tape is the clear winner in magnetic performance but its susceptibility to wear and corrosion, make it less than ideal for data storage.

Peter, Klaus J.; Speliotis, Dennis E.

317

A study on friction stir welding of 12mm thick aluminum alloy plates  

NASA Astrophysics Data System (ADS)

Most of the investigations regarding friction stir welding (FSW) of aluminum alloy plates have been limited to about 5 to 6 mm thick plates. In prior work conducted the various aspects concerning the process parameters and the FSW tool geometry were studied utilizing friction stir welding of 12 mm thick commercial grade aluminum alloy. Two different simple-to-manufacture tool geometries were used. The effect of varying welding parameters and dwell time of FSW tool on mechanical properties and weld quality was examined. It was observed that in order to achieve a defect free welding on such thick aluminum alloy plates, tool having trapezoidal pin geometry was suitable. Adequate tensile strength and ductility can be achieved utilizing a combination of high tool rotational speed of about 2000 r/min and low speed of welding around 28 mm/min. At very low and high dwell time the ductility of welded joints are reduced significantly.

Kumar, Deepati Anil; Biswas, Pankaj; Tikader, Sujoy; Mahapatra, M. M.; Mandal, N. R.

2013-12-01

318

Ultrastructural response of rat lung to 90 days' exposure to oxygen at 450 mm Hg  

NASA Technical Reports Server (NTRS)

Young Sprague-Dawley rats were exposed to 100% oxygen at 450 mm Hg in constant environment capsules for 90 days. Lung tissue examined by electron microscopy revealed a number of changes, many similar to those observed after exposure to oxygen at 760 mm Hg for shorter periods of time. Alterations in vesicle size and number and in mitochondrial matrix and cristae appear in both the endothelial and epithelial cells. Blebbing and rarefication of cytoplasm occur in both cell layers of the alveolo-capillary wall. Also seen are fluid in the basement membrane, platelets in the capillaries, and alveolar fluid and debris. All of these alterations occur at 1 atm exposure. However, after exposure to 450 mm Hg the changes are not as widespread nor as destructive as they are at the higher pressure.

Harrison, G. A.

1974-01-01

319

Evidence for Highly Inhomogeneous mm-Wave Sources During the Impulsive Flare of May 9, 1991  

NASA Technical Reports Server (NTRS)

In this paper multiwavelength observations of an impulsive flare of May 9, 1991 are presented. This event was observed with the 48 GHz multibeam focal array used at the Itapetinga radio telescope, the microwave patrol telescopes at Bem and the BATSE high time resolution hard X-ray spectrometer on board CGRO. While spatially unresolved low sensitivity observations show two major impulsive peaks, the mm-wave observations with the ability of spatially high resolved tracking of the emission centroids suggest a primarily bipolar source configuration. For the first time two mm-wave sources with a spacing below the HPBW could be separated with the multibeam technique. The general features of the observations are explained as emission of partially trapped electrons. Furthermore we present evidence for highly inhomogeneous substructures within one of the two mm-wave sources for which the positional scatter of the emission center, within 2s, is less than 2".

Hermann, R.; Magun, A.; Kaufmann, P.; Correia, E.; Costa, J. E. R.; Machado, M. E.; Fishman, G.

1997-01-01

320

A 12-mm carcinoid tumor of the minor duodenal papilla with lymph node metastases.  

PubMed

Carcinoid tumors located in the minor duodenal papilla are extremely rare, with only a few cases reported in the literature. Herein, we report the case of a 71-year-old man with a 12-mm carcinoid tumor at the minor duodenal papilla with lymph node metastases. Multidetector-row computed tomography with contrast enhancement revealed a 12-mm well-enhanced tumor in the duodenum. Upper gastrointestinal endoscopy showed a 12-mm submucosal tumor at the minor papilla of the duodenum. Biopsy specimens revealed a carcinoid tumor, and a subtotal stomach-preserving pancreatoduodenectomy was performed. Carcinoid tumors at the minor duodenal papilla have a high prevalence of nodal disease, even for tumors <2 cm in diameter. Therefore, we believe that radical resection with tumor-free margins (i.e. pancreatoduodenectomy) is the treatment of choice. PMID:23136240

Fukami, Yasuyuki; Kurumiya, Yasuhiro; Mizuno, Keisuke; Sekoguchi, Ei; Kobayashi, Satoshi; Ito, Akira; Tomida, Akihiro; Onishi, Sakura; Shirotsuki, Ryo; Okubo, Kenji; Narita, Michihiko

2013-01-01

321

Ground-based mm-wave emission spectroscopy for the detection and monitoring of stratospheric ozone  

NASA Technical Reports Server (NTRS)

The molecular rotational spectrum of ozone is quite rich in the mm-wave region from 50 to 300 GHz. An apparatus, which was developed primarily for detection and measurement of stratospheric ClO and other trace molecules, is found to be well suited also for the observation of ozone lines. The collecting antenna of the apparatus is a simple mm-waveguide feedhorn. The detector is a superheterodyne mixer using a special high frequency Schottky diode and a klystron local oscillator. The spectrometer is a 256 channel filter bank with 1 MHz resolution per channel. The apparatus is believed to be the first ground-based mm-wave instrument having the capability of obtaining data of sufficient quality to make use of the inversion technique. The ground based radio technique is most sensitive to changes in vertical distribution in the region above 25 km, a region which is difficult to sample by other techniques.

Parrish, A.; Dezafra, R.; Solomon, P.

1981-01-01

322

Micromelanomas: A Review of Melanomas ?2?mm and a Case Report  

PubMed Central

The ABCD acronym used to screen pigmented lesions for melanoma obviously was not designed to contend with melanomas that are under 2?mm in diameter. Previously, views ranged that such small lesions could not be melanomas until a few reports of such “micromelanomas” emerged. The author presents a 2?mm melanoma in situ presenting as an insignificant pigmented lesion in a 60-year-old patient with no previous history of melanoma or multiple nevi—which is usually the norm in cases of small melanoma. This paper reiterates the fact that when it comes to a melanoma, size does not matter. In this paper, the term “micromelanoma” is used by the author to represent melanomas under 2?mm. Dermatoscopy and histopathology findings are discussed in this case, along with a review of small melanomas. PMID:24716040

Paul, Sharad P.

2014-01-01

323

Influence of cation type, ionic strength, and pH on solubilization and mobilization of residual hydrocarbon by a biosurfactant  

NASA Astrophysics Data System (ADS)

This study investigated the effect of cation type, ionic strength, and pH on the performance of an anionic monorhamnolipid biosurfactant for solubilization and removal of residual hexadecane from sand. Three common soil cations, Na +, Mg 2+, and Ca 2+, were used in these experiments and hexadecane was chosen to represent a nonaqueous phase liquid (NAPL) less dense than water. Results showed that hexadecane solubility in rhamnolipid solution was significantly increased by the addition of Na + and Mg 2+. Addition of up to 0.2 mM Ca 2+ also increased hexadecane solubility. For Ca 2+ concentrations greater than 0.2 mM there was little effect on hexadecane solubility due to competing effects of calcium-induced rhamnolipid precipitation and enhanced hexadecane solubilization. Efficiency of NAPL solubilization can be expressed in terms of molar solubilization ratios (MSR). The results showed that MSR values for hexadecane in rhamnolipid solutions increased 7.5-fold in the presence of 500 mM Na +, and 25-fold in the presence of 1 mM Mg 2+. The presence of cations also reduced the interfacial tension between rhamnolipid solutions and hexadecane. For example, an increase in Na + from 0 to 800 mM caused a decrease in interfacial tension from 2.2 to 0.89 dyn cm -1. Similarly, decreasing pH caused a reduction in interfacial tension. The lowest interfacial tension value observed in this study was 0.02 dyn cm -1 at pH 6 in the presence of 320 mM Na +. These conditions were also found to be optimal for removal of hexadecane residual from sand columns, with 58% of residual removed within three pore volumes. The removal of residual NAPL from the packed columns was primarily by mobilization, even though solubilization was significantly increased in the presence of Na +.

Bai, Guiyun; Brusseau, Mark L.; Miller, Raina M.

1998-04-01

324

Relations structurales entre U 3O 8 et quelques fluorures mixtes de formules M2M' 3F 11, MM' 2F 7 et MM' 3F 10  

NASA Astrophysics Data System (ADS)

U 3O 8 oxide, as well as M2M' 3F 11, MM' 2F 7 and MM' 3F 10 fluorides, with M = Rb, Tl, Cs, NH 4 and M' = In, Lu, Yb, Tm, is described as the regular repetition according to the … A-A-A … sequence of identical and parallel sheets of edge-and corner-sharing M'F 7 or UO 7 pentagonal bipyramids and M'F 6 octahedra. M' and U atoms are systematically located at the lattice points of a pseudohexagonal network, but in the fluorides some of these lattice points are vacant, producing hexagonal tunnels in which M atoms are located. It is shown that in the two kinds of compounds the same linear chains and M' 3X17 groups of pentagonal bipyramids are present, and that the transformation of the U 3O 8 structure into the fluorides can be achieved by an ordered substitution of some linear … U?O?U?O … chains by … M- M- M … chains. All these structures can be described with the same structural model based on the chemical twinning principle.

Aléonard, S.; Le Fur, Y.; Champarnaud-Mesjard, J. C.; Frit, B.; Roux, M. Th.

1983-01-01

325

Anisodamine accelerates spontaneous passage of single symptomatic bile duct stones ? 10 mm  

PubMed Central

AIM: To investigate the rate of spontaneous passage of single and symptomatic common bile duct (CBD) stones ? 10 mm in diameter in 4 wk with or without a 2-wk course of anisodamine. METHODS: A multicenter, randomized, placebo-controlled trial was undertaken. A total of 197 patients who met the inclusion criteria were enrolled. Ninety-seven patients were assigned randomly to the control group and the other 100 to the anisodamine group. The anisodamine group received intravenous infusions of anisodamine (10 mg every 8 h) for 2 wk. The control group received the same volume of 0.9% isotonic saline for 2 wk. Patients underwent imaging studies and liver-function tests every week for 4 wk. The rate of spontaneous passage of CBD stones was analyzed. RESULTS: The rate of spontaneous passage of CBD stones was significantly higher in the anisodamine group than that in the control group (47.0% vs 22.7%). Most (87.2%, 41/47) stone passages in the anisodamine group occurred in the first 2 wk, and passages in the control group occurred at a comparable rate each week. Factors significantly increasing the possibility of spontaneous passage by univariate logistic regression analyses were stone diameter (< 5 mm vs ? 5 mm and ? 10 mm) and anisodamine therapy. Multivariate logistic regression analyses revealed that these two factors were significantly associated with spontaneous passage. CONCLUSION: Two weeks of anisodamine administration can safely accelerate spontaneous passage of single and symptomatic CBD stones ? 10 mm in diameter, especially for stones < 5 mm. PMID:24151390

Gao, Jun; Ding, Xue-Mei; Ke, Shan; Zhou, Yi-Ming; Qian, Xiao-Jun; Ma, Rui-Liang; Ning, Chun-Min; Xin, Zong-Hai; Sun, Wen-Bing

2013-01-01

326

The Galactic Centre Mini-Spiral in the MM-Regime  

NASA Technical Reports Server (NTRS)

Context: The mini-spiral is a feature of the interstellar medium in the central approx.2 pc of the Galactic center. It is composed of several streamers of dust and ionised and atomic gas with temperatures between a few 100 K to 10(exp 4) K. There is evidence that these streamers are related to the so-called circumnuclear disk of molecular gas and are ionized by photons from massive, hot stars in the central parsec. Aims: We attempt to constrain the emission mechanisms and physical properties of the ionized gas and dust of the mini-spiral region with the help of our multiwavelength data sets. Methods: Our observations were carried out at 1.3 mm and 3 mm with the mm interferometric array CARMA in California in March and April 2009, with the MIR instrument VISIR at ESO's VLT in June 2006, and the NIR Bry with VLT NACO in August 2009. Results: We present high resolution maps of the mini-spiral, and obtain a spectral index of 0.5 +/- 0.25 for Sgr A *, indicating an inverted synchrotron spectrum. We find electron densities within the range 0.8-1.5 x 10(exp 4)/cu cm for the mini-spiral from the radio continuum maps, along with a dust mass contribution of approx. 0.25 Mo from the MIR dust continuum. and extinctions ranging from 1.8-3 at 2.16 microns in the Bry line. Conclusions: We observe a mixture of negative and positive spectral indices in our 1.3 mm and 3 mm observations of the extended emission of the mini-spiral, which we interpret as evidence that there are a range of contributions to the thermal free-free emission by the ionized gas emission and by dust at 1.3 mm.

Kunneriath, D.; Eckart, A.; Vogel, S. N.; Teuben, P.; Muzic, I.; Schoedel, R.; Garcia-Marin, M.; Moultaka, J.; Staguhn, J.; Straubmeier, C.; Zensus, J. A.; Valencia-S., M.; Karas, V.

2012-01-01

327

XMM-Newton Surveys of the CFRS Fields - I: The Sub-mm/X-ray relation  

E-print Network

First results from XMM-Newton observations of the Canada France Redshift Survey (CFRS) 3hr, 10hr and 14hr fields are presented. Limited regions of two of the XMM surveys (3 and 14hr) are compared to the Canada UK Deep sub-mm Surveys (CUDSS) undertaken with SCUBA. None of the 27 SCUBA sources in the 3hr field are detected by XMM, while one of the 23 SCUBA sources in the 14hr field is found to coincide with an X-ray source. The SCUBA population as a whole is not significantly detected in either the 0.5-2 keV or the 2-10 keV X-ray bands, even after coadding the X-ray flux at the SCUBA positions, in both fields. The 18 X-ray sources within the CUDSS 3hr map yield a mean sub-mm flux of 0.48+-0.27 mJy after coadding the sub-mm flux at the X-ray positions. Using this result we place an upper limit on the contribution of AGN to the sub-mm background at 850 microns of ~7 per cent. Conversely we estimate the contribution of sub-mm sources to the 0.5-2 keV X-ray background to be 2.3. The ratio of the X-ray to sub-mm flux for the X-ray sources however, implies that even when a galaxy does contain an AGN, most of the energy heating the dust is from young stars and not from the active nucleus.

Timothy J. Waskett; Stephen A. Eales; Walter K. Gear; Elizabeth M. Puchnarewicz; Simon Lilly; Hector Flores; Tracy Webb; David Clements; Jason A. Stevens; Trinh X. Thuan

2003-01-30

328

IMPEE PhD Opportunity Project title: LightFoot PhD A PhD Investigation Lightning Protection of HV Overhead Lines with Non-Ideal  

E-print Network

IMPEE PhD Opportunity Project title: LightFoot PhD ­ A PhD Investigation Lightning Protection of HV.swingler@hw.ac.uk Abstract LightFoot PhD ­ A PhD Investigation Lightning Protection of HV Overhead Lines with Non-Ideal Tower to the understanding of the effect of lightning strikes on an overhead transmission line in terms of its electrical

Greenaway, Alan

329

Regulation of cytoplasmic pH of cultured bovine corneal endothelial cells in the absence and presence of bicarbonate  

Microsoft Academic Search

Summary Intracellular pH (pHi) in confluent monolayers of cultured bovine corneal endothelial cells was determined using the pH-dependent absorbance of intracellularly trapped 5(and 6)carboxy-4',5'-dimethylfluorescein. Steady-state pH was 7.05±0.1 in the nominal absence of bicarbonate, and 7.15±0.1 in the presence of 28mm HCO3-\\/5% CO2. Following an acid load imposed by a NH4Cl prepulse, pHi was regulated in the absence of HCO3-

Thomas J. Jentsch; Christoph Korbmacher; Ilse Janicke; Dieter G. Fischer; Frank Stahl; Horst Helbig; Herwig Hollwede; Edward J. Cragoe; Svea K. Keller; Michael Wiederholt

1988-01-01

330

12 W\\/mm AlGaN-GaN HFETs on silicon substrates  

Microsoft Academic Search

Al0.26Ga0.74N-GaN heterojunction field-effect transistors were grown by metal-organic chemical vapor deposition on high-resistivity 100-mm Si (111) substrates. Van der Pauw sheet resistance of the two-dimensional electron gas was 300 ?\\/square with a standard deviation of 10 ?\\/square. Maximum drain current density of ?1 A\\/mm was achieved with a three-terminal breakdown voltage of ?200 V. The cutoff frequency and maximum frequency

J. W. Johnson; E. L. Piner; A. Vescan; R. Therrien; P. Rajagopal; J. C. Roberts; J. D. Brown; S. Singhal; K. J. Linthicum

2004-01-01

331

Ionization Measurements of SuperCDMS SNOLAB 100 mm Diameter Germanium Crystals  

SciTech Connect

Scaling cryogenic Germanium-based dark matter detectors to probe smaller WIMP-nucleon cross-sections poses significant challenges in the forms of increased labor, cold hardware, warm electronics and heat load. The development of larger crystals alleviates these issues. The results of ionization tests with two 100 mm diameter, 33 mm thick cylindrical detector-grade Germanium crystals are presented here. Through these results the potential of using such crystals in the Super Cryogenic Dark Matter Search (SuperCDMS) SNOLAB experiment is demonstrated.

Chagani, H.; /Minnesota U.; Bauer, D.A.; /Fermilab; Brandt, D.; Brink, P.L.; /SLAC; Cabrera, B.; Cherry, M.; /Stanford U.; Silva, E.Do Couto e; Godfrey, G.G.; /SLAC; Hall, J.; Hansen, S.; /Fermilab; Hasi, J.; Kelsey, M.; Kenney, C.J.; /SLAC; Mandic, V.; /Minnesota U.; Nagasawa, D.; Novak, L.; /Stanford U.; Mirabolfathi, N.; /UC, Berkeley; Partridge, R.; /SLAC; Radpour, R.; /Minnesota U.; Resch, R.; /SLAC; Sadoulet, B.; /UC, Berkeley /Stanford U. /SLAC /Stanford U. /Santa Clara U. /Minnesota U.

2012-06-12

332

Fe/Al2O3 C2H4 Hata mm/10 min  

E-print Network

Fe/Al2O3 C2H4 () () () () () () () * () 1. (SWNT) SWNT (CVD) (CNT)[1] Hata mm/10 min SWNT (Super Growth)[2]Al2O3 Fe C2H4 SWNT Fe/Al2O3 C2H4 CVD SWNT CNT CNT 2 SiO2 Al2O3 20 Al Fe 0.5 nm1 mm Al 700 CVD Al Al2O3 Al2O3 SiO2Fe CNT 750 850 820 CNT G/D 850 m H2 200

Maruyama, Shigeo

333

2-way coupling the hydrological land surface model PROMET with the regional climate model MM5  

NASA Astrophysics Data System (ADS)

Most land surface hydrological models (LSHMs) consider land surface processes (e.g. soil-plant-atmosphere interactions, lateral water flows, snow and ice) in a spatially detailed manner. The atmosphere is considered as exogenous driver, neglecting feedbacks between the land surface and the atmosphere. On the other hand, regional climate models (RCMs) generally simulate land surface processes through coarse descriptions and spatial scales but include land-atmosphere interactions. What is the impact of the differently applied model physics and spatial resolution of LSHMs on the performance of RCMs? What feedback effects are induced by different land surface models? This study analyses the impact of replacing the land surface module (LSM) within an RCM with a high resolution LSHM. A 2-way coupling approach was applied using the LSHM PROMET (1 × 1 km2) and the atmospheric part of the RCM MM5 (45 × 45 km2). The scaling interface SCALMET is used for down- and upscaling the linear and non-linear fluxes between the model scales. The change in the atmospheric response by MM5 using the LSHM is analysed, and its quality is compared to observations of temperature and precipitation for a 4 yr period from 1996 to 1999 for the Upper Danube catchment. By substituting the Noah-LSM with PROMET, simulated non-bias-corrected near-surface air temperature improves for annual, monthly and daily courses when compared to measurements from 277 meteorological weather stations within the Upper Danube catchment. The mean annual bias was improved from -0.85 to -0.13 K. In particular, the improved afternoon heating from May to September is caused by increased sensible heat flux and decreased latent heat flux as well as more incoming solar radiation in the fully coupled PROMET/MM5 in comparison to the NOAH/MM5 simulation. Triggered by the LSM replacement, precipitation overall is reduced; however simulated precipitation amounts are still of high uncertainty, both spatially and temporally. The distribution of precipitation follows the coarse topography representation in MM5, resulting in a spatial shift of maximum precipitation northwards of the Alps. Consequently, simulation of river runoff inherits precipitation biases from MM5. However, by comparing the water balance, the bias of annual average runoff was improved from 21.2% (NOAH/MM5) to 4.4% (PROMET/MM5) when compared to measurements at the outlet gauge of the Upper Danube watershed in Achleiten.

Zabel, F.; Mauser, W.

2013-05-01

334

@2012 Mehran Mehregany, Ph.D. Mehran Mehregany, Ph.D.  

E-print Network

connectivity cloud computing social networks #12;@2012 Mehran Mehregany, Ph.D. Nonintrusive Monitoring unprecedented mobility...working, entertainment, shopping, socializing, gaming, etc., anytime, anywhere

Rollins, Andrew M.

335

MRF with adjustable pH  

NASA Astrophysics Data System (ADS)

Deterministic final polishing of high precision optics using sub-aperture processing with magnetorheological finishing (MRF) is an accepted practice throughout the world. A wide variety of materials can be successfully worked with aqueous (pH 10), magnetorheological (MR) fluids, using magnetic carbonyl iron (CI) and either ceria or nanodiamond nonmagnetic abrasives. Polycrystalline materials like zinc sulfide (ZnS) and zinc selenide (ZnSe) are difficult to polish at pH 10 with MRF, due to their grain size and the relatively low stiffness of the MR fluid lap. If microns of material are removed, the grain structure of the material begins to appear. In 2005, Kozhinova et al. (Appl. Opt. 44 4671-4677) demonstrated that lowering pH could improve MRF of ZnS. However, magnetic CI particle corrosion rendered their low pH approach unstable and unsuitable for commercial implementation. In 2009, Shafrir et al. described a sol-gel coating process for manufacturing a zirconia-coated CI particle that protects the magnetic core from aqueous corrosion (Appl. Opt .48 6797-6810). The coating process produces free nanozirconia polishing abrasives during the coating procedure, thereby creating an MR polishing powder that is "self-charged" with the polishing abrasive. By simply adding water, it was possible to polish optical glasses and ceramics with good stability at pH 8 for three weeks. The development of a corrosion resistant, MR polishing powder, opens up the possibility for polishing additional materials, wherein the pH may be adjusted to optimize effectiveness. In this paper we describe the CI coating process, the characterization of the coated powder, and procedures for making stable MR fluids with adjustable pH, giving polishing results for a variety of optical glasses and crystalline ceramics.

Jacobs, Stephen D.

2011-10-01

336

Eukaryotic diversity at pH extremes  

PubMed Central

Extremely acidic (pH < 3) and extremely alkaline (pH > 9) environments support a diversity of single-cell and to a lesser extent, multicellular eukaryotic life. This study compared alpha and beta diversity in eukaryotic communities from seven diverse aquatic environments with pH values ranging from 2 to 11 using massively-parallel pyrotag sequencing targeting the V9 hypervariable region of the 18S ribosomal RNA (rRNA) gene. A total of 946 operational taxonomic units (OTUs) were recovered at a 6% cut-off level (94% similarity) across the sampled environments. Hierarchical clustering of the samples segregated the communities into acidic and alkaline groups. Similarity percentage (SIMPER) analysis followed by indicator OTU analysis (IOA) and non-metric multidimensional scaling (NMDS) were used to determine which characteristic groups of eukaryotic taxa typify acidic or alkaline extremes and the extent to which pH explains eukaryotic community structure in these environments. Spain's Rio Tinto yielded the fewest observed OTUs while Nebraska Sandhills alkaline lakes yielded the most. Distinct OTUs, including metazoan OTUs, numerically dominated pH extreme sites. Indicator OTUs included the diatom Pinnularia and unidentified opisthokonts (Fungi and Filasterea) in the extremely acidic environments, and the ciliate Frontonia across the extremely alkaline sites. Inferred from NMDS, pH explained only a modest fraction of the variation across the datasets, indicating that other factors influence the underlying community structure in these environments. The findings from this study suggest that the ability for eukaryotes to adapt to pH extremes over a broad range of values may be rare, but further study of taxa that can broadly adapt across diverse acidic and alkaline environments, respectively present good models for understanding adaptation and should be targeted for future investigations. PMID:23335919

Amaral-Zettler, Linda A.

2013-01-01

337

Version 3.0 SOP 6a --pH October 12, 2007 pH (total hydrogen  

E-print Network

Version 3.0 SOP 6a -- pH October 12, 2007 117 SOP 6a pH - / 1. pH (total hydrogen ion concentration pH scale) . , [H+ ] 1 kg . 2. . F T S F 4 [H ] [H ] (1 / ) [H ] [HSO ] S K+ + + - = + + (1) [H+ ]F (free concentration), ST ([HSO4 - ]+[SO4 2- ]) KS [HSO4 - ] . pH . 10 1 [H ] pH

338

Intracellular pH regulation in rat Schwann cells.  

PubMed

We examined H+ and HCO3- transport mechanisms that are involved in the regulation of intracellular pH of Schwann cells. Primary cultures of Schwann cells were prepared from the sciatic nerves of 1-3-day-old rats. pHi of single cells attached to cover slips was continuously monitored by measuring the absorbance spectra of the pH-sensitive dye dimethylcarboxyfluorescein incorporated intracellularly. The average pHi of neonatal Schwann cells bathed in HEPES mammalian solution was 7.17 +/- 0.02 (n = 32). In the nominal absence of HCO3-, pHi spontaneously recovered from an acute acid load induced by exposing the Schwann cells to 20 mM NH4+ (NH4+ prepulse). This pHi recovery from the acute acid load was totally inhibited in the absence of external Na+ or in the presence of 1 mM amiloride. In both cases, the pHi recovery was readily restored upon readdition of external Na+ or removal of amiloride. In the steady-state, addition of amiloride caused a small and slow decrease in pHi which was readily reversed upon removal of amiloride. In the presence of HCO3-, removal of external Cl- caused pHi to rapidly and reversibly increase by 0.23 +/- 0.03 (n = 15) and the initial rate of alkalinization was 20.6 +/- 2.7 x 10(-4) pH/sec. In the absence of external Na+, removal of bath Cl- still caused pHi to increase by 0.15 +/- 0.02 and the initial rate of pHi increase was not significantly altered. In the nominal absence of HCO3-, removal of bath Cl- caused pHi to increase very slightly (0.05 +/- 0.01) with an initial dpHi/dt of only 4.4 +/- 0.2 x 10(-4) pH/sec (n = 4). Addition of 100 microM DIDS did not inhibit the pHi increase caused by removal of bath Cl-. These data indicate that 1) Rat Schwann cells regulate their pHi via an Na-H exchange mechanism which is moderately active at steady-state pHi. 2) In the presence of HCO3-, there is a Na-independent Cl-HCO3 (base) exchanger which also contributes to regulation of intracellular pH in Schwann cells. PMID:8194859

Nakhoul, N L; Abdulnour-Nakhoul, S; Khuri, R N; Lieberman, E M; Hargittai, P T

1994-03-01

339

Guide to Foreign-Government Loan Film (16 mm). First Edition, 1969-70.  

ERIC Educational Resources Information Center

More than 3,000 films (16 mm.) available on loan in the United States under the auspices of 66 foreign governments are catalogued. About 1,800 of them may be borrowed at no charge, and the rest at a nominal fee. Many of the listings are simply tourist films, but others deal with the country's history, literature, culture, people, and politics. The…

1969

340

The M&M Approach: Using Mental and Mechanical Strategies in Teaching and Coaching  

ERIC Educational Resources Information Center

Mental and mechanical (M&M) techniques are very useful in teaching and coaching. Mental techniques are strategies that enhance movement through psychological preparation, such as using imagery to practice a skill. Mechanical techniques are strategies that enhance the physical side of the movement, such as correcting the biomechanics of a golf…

Rhea, Chris K.; Wisdom, Stacey

2007-01-01

341

SUR LES VALENCES DU POLONIUM Par MM. HAISSINSKY et M. GUILLOT.  

E-print Network

SUR LES VALENCES DU POLONIUM Par MM. HAISSINSKY et M. GUILLOT. Sommaire. - L'addition de quantités croissantes d'électrolytes aux solutions acides de polonium pro- voque un déplacement du potentiel critique de ions du polonium. La confrontation de ce résultat avec ceux d'expériences antérieures de

Boyer, Edmond

342

Comments on the papers recently published by M.M. Khandpekar et al.  

NASA Astrophysics Data System (ADS)

It is argued that the existence of the new compounds of glycine recently reported by M.M. Khandpekar et al. (Optics Commun. 284(2011) 1583 and Optics Commun. 284(2011) 1578) is dubious. We argue that these compounds are not what the authors propose. In addition, two more similar cases are indicated.

Petrosyan, A. M.; Ghazaryan, V. V.; Fleck, M.

2011-09-01

343

14. Main room; view no southwest, 65mm lens with electronic ...  

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

14. Main room; view no southwest, 65mm lens with electronic flash illumination. The mountain visible through the windows was a landmark for the camp population. - Tule Lake Project Jail, Post Mile 44.85, State Route 139, Newell, Modoc County, CA

344

Evaluation of MM5 Simulations With HTSVS With and Without Inclusion of Soil-Frost Parameterization  

E-print Network

Evaluation of MM5 Simulations With HTSVS With and Without Inclusion of Soil-Frost Parameterization and seasonally frozen ground are important surface features in high- latitudes. Because of this, a soil-frost and observations of precipitation were used to evaluate the importance of the soil-frost parameterization

Moelders, Nicole

345

Proton and hydride transfers in solution: hybrid QMmm/MM free energy perturbation study  

SciTech Connect

A hybrid quantum and molecular mechanical (QM/MM) free energy perturbation (FEP) method is implemented in the context of molecular dynamics (MD). The semiempirical quantum mechanical (QM) Hamiltonian (Austin Model 1) represents solute molecules, and the molecular mechanical (MM) CHARMM force field describes the water solvent. The QM/MM FEP method is used to calculate the free energy changes in aqueous solution for (1) a proton transfer from methanol to imidazole and (2) a hydride transfer from methoxide to nicotinamide. The QM/MM interaction energies between the solute and solvent arc calibrated to emulate the solute-solvent interaction energies determined at the Hartee-Fock 6-31G(d) level of ab initio theory. The free energy changes for the proton and hydride transfers are calculated to be 15.1 and {minus}6.3 kcal/mol, respectively, which compare favorably with the corresponding experimental values of 12.9 and {minus}7.4 kcal/mol. An estimate of the reliability of the calculations is obtained through the computation of the forward (15.1 and {minus}6.3 kcal/mol) and backward ({minus}14.1 and 9.1 kcal/mol)free energy changes. The reasonable correspondence between these two independent calculations suggests that adequate phase space sampling is obtained along the reaction pathways chosen to transform the proton and hydride systems between their respective reactant and product states.

Ho, L. Lawrence [Yale Univ., New Haven, CT (United States). Gibbs Lab.]|[Argonne National Lab., IL (United States); Bash, P.A. [Argonne National Lab., IL (United States); Kerell, A.D., Jr [Maryland University, Baltimore, MD (United States). School of Pharmacy

1996-03-01

346

2. West portal of Tunnel 1, view to northeast, 135mm ...  

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

2. West portal of Tunnel 1, view to northeast, 135mm lens. Like the new tunnels built during this period, Tunnel 1 received a new concrete portal face with granite masonry voussoirs and coping. - Central Pacific Transcontinental Railroad, Tunnel No. 1, Milepost 164.34, Blue Canyon, Placer County, CA

347

3. East portal of Tunnel 34, view to southsouthwest, 135mm ...  

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

3. East portal of Tunnel 34, view to south-southwest, 135mm lens with electronic flash fill. Note the shift, in these later tunnels east of Colfax, to concrete portal faces with granite masonry voussoirs and coping. - Central Pacific Transcontinental Railroad, Tunnel No. 34, Milepost 145.4, Colfax, Placer County, CA

348

Double-channel 8 mm band radiometer for atmospheric remote sensing  

Microsoft Academic Search

A double-channel 8 mm band radiometer is presented in this paper, which has been used for atmospheric remote sensing. This radiometer adopts a novel technique to reduce influence of the receiver RF and IF gain on its sensitivity, in which double-channel methods, AC channel and DC channel, is employed. Practical measured results show this radiometer has enough stability in long

S. S. Peng; L. Wu; X. H. Ying; Z. C. Xu

2006-01-01

349

MAPPING GREEN MACROALGAE BLOOMS IN A PACIFIC NORTHWEST ESTUARY VIA 35-MM AERIAL PHOTOS  

EPA Science Inventory

Summer blooms of green macroalgae (mainly Ulva spp. and Enteromorpha spp.) on intertidal mudflats of Oregon's Yaquina Bay estuary were documented using oblique 35-mm color-infrared aerial photographs taken at low tide. Costs were controlled by use of a small airplane from a loc...

350

5. East portal of Tunnel 18, view to westsouthwest, 135mm ...  

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

5. East portal of Tunnel 18, view to west-southwest, 135mm lens. The train exiting the tunnel, though northbound toward Portland, is considered an eastbound train on the Southern Pacific (see explanation above). - Southern Pacific Railroad Natron Cutoff, Tunnel No. 18, Milepost 410, Dorris, Siskiyou County, CA

351

3. West portal of Tunnel 18, view to northeast, 135mm ...  

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

3. West portal of Tunnel 18, view to northeast, 135mm lens. Note the use of concrete face and wingwalls, with dressed stone voussoirs, wingwall coping, parapet with stone belt course and coping, and coursed stone masonry slope protection flanking the portal. - Southern Pacific Railroad Natron Cutoff, Tunnel No. 17, Milepost 408, Dorris, Siskiyou County, CA

352

Modified Ledatron and Orotron tubes with improved sub-mm performance  

NASA Astrophysics Data System (ADS)

In the present note two types of open resonator with improved performance with respect to those currently used in Ledatron or Orotron sub-mm generators are analysed. A reduction of the starting current by one or two orders of magnitude respectively has been obtained.

Risaliti, R.; Ronchi, L.; Scordino, A.

1988-09-01

353

Characteristics of VHF capacitively coupled plasmas in a 300 mm chamber  

Microsoft Academic Search

We have investigated the characteristics of VHF capacitively coupled plasmas produced in a modified Applied Materials chamber. The chamber had a 14-inch diameter upper electrode (source) that was driven at 10 to 160 MHz and a 300 mm diameter electrostatic chuck with a ceramic process kit that was driven at 13.56 MHz (bias). Diagnostics employed include rf diagnostics to measure

G. A. Hebner; P. A. Miller; E. V. Barnat; A. Paterson; J. Holland; T. Lill

2004-01-01

354

Influence of frequency on the characteristics of VHF capacitively coupled plasmas in a 300 mm chamber  

Microsoft Academic Search

We have investigated the characteristics of VHF capacitively coupled plasmas produced in a modified Applied Materials chamber. The chamber had a 14-inch diameter upper electrode (source) that was driven at 10 to 160 MHz and a 300 mm diameter electrostatic chuck with a ceramic process kit that was driven at 13.56 MHz (bias). Diagnostics employed include a microwave interferometer to

G. A. Hebner; E. V. Barnat; P. A. Miller; A. Paterson; J. Holland; T. Lill

2004-01-01

355

Electrothermal-Chemical Ignition Research on 120-mm Gun in Korea  

Microsoft Academic Search

Electrothermal-chemical (ETC) propulsion with the control of a combustion process yet requires large electrical energies for an appreciable effect. Referring to the changed tendency of focusing ETC researches on the early ignition phase, the Agency for Defense Development (ADD), Korea, has been studying an electrothermal ignition for a 120-mm gun using a capillary plasma injector. Under the condition of a

Seong Ho Kim; Kyung Seung Yang; Young Hyun Lee; Jin Sung Kim; Byung Ha Lee

2009-01-01

356

Ramesh Gupta, March 30, 2010 Initial Design of 200 mm, 6 T  

E-print Network

Ramesh Gupta, March 30, 2010 Initial Design of 200 mm, 6 T Superconducting Solenoid for e-lens Ramesh Gupta March 30, 2010 #12;Ramesh Gupta, March 30, 2010 Main Features · Dipole copper correctors;Ramesh Gupta, March 30, 2010 Overview of the Design Presentation · Overall design of the sc solenoid

Ohta, Shigemi

357

Ramesh Gupta, April 6, 2010 Iterated Design of 200 mm, 6 T  

E-print Network

Ramesh Gupta, April 6, 2010 Iterated Design of 200 mm, 6 T Superconducting Solenoid for e-lens Ramesh Gupta April 6, 2010 #12;Ramesh Gupta, April 6, 2010 Small Superconducting Solenoid next to Main). Another design: Fringe field coils further out where they are more effective #12;Ramesh Gupta, April 6

Ohta, Shigemi

358

Breakdown of 2mm symmetry in electron diffraction from multiwalled carbon nanotubes  

E-print Network

when coherent interferences of the electron waves from two different shells take place such as when twoBreakdown of 2mm symmetry in electron diffraction from multiwalled carbon nanotubes Zejian Liu; in final form 4 December 2004 Available online 24 December 2004 Abstract Electron diffraction patterns

Qin, Lu-Chang

359

Effective Focal Shift at Target (mm) -3 -2 -1 0 1 2 3  

E-print Network

Zernike defocus coefficient Based on the Rc, calculate the effective focal shift using the thin lens the discharge delay which varies with the depth of the density channel, n. Beam pointing fluctuation introduces 0.5 mm fluctuation on the effective focal shift x1.5 118 ns 227 ns 427 ns 715 ns Discharge Delay (ns

360

Polarization and Charge-Transfer Effects in Aqueous Solution via Ab Initio QM/MM Simulations  

E-print Network

Polarization and Charge-Transfer Effects in Aqueous Solution via Ab Initio QM/MM Simulations Yirong, acetate and methylammonium ions in aqueous solution. Calculations reveal that the electronic polarization, the polarization effect is dominated by the solvent (water) polarization. Introduction Computer simulation offers

Minnesota, University of

361

Laser-Assisted Stir Welding of 25-mm-Thick HSLA65 Plate  

Microsoft Academic Search

Laser-assisted stir welding is a hybrid process that combines energy from a laser with functional heating and mechanical energy to join materials in the solid state. The technology is an adaptation of friction stir welding which is particularly suited for joining thick plates. Aluminum plates up to 75 mm thick have been successfully joined using friction stir welding. Since joining

Keith M. Williamson

2002-01-01

362

STS-30 MS Lee, wearing sunglasses, uses 70mm camera on aft flight deck  

NASA Technical Reports Server (NTRS)

STS-30 Atlantis, Orbiter Vehicle (OV) 104, Mission Specialist (MS) Mark C. Lee, wearing sunglasses and light blue flight coveralls, holds a 70mm camera on aft flight deck. Lee prepares to take pictures of the Earth surface outside overhead window W8. Aft flight deck viewing window W10 and onorbit station control panels appear behind him.

1989-01-01

363

[Endoscopic transthoracic sympathectomy (ETS) with a fine 2-mm thoracoscope in palmar hyperhidrosis].  

PubMed

Endoscopic transthoracic sympathectomy (ETS) is an efficient, safe, minimally invasive procedure, and requires only a short period of hospitalization. We performed bilateral ETS using a thoracoscope 2 mm in diameter. We performed 120 ETS for the treatment of palmar hyperhidrosis from August 1997 to April 2000. The patient was placed in the semi-sitting position under general anesthesia, one-lung ventilation being used; the operation was performed with 2-mm two-puncture method. The sympathetic chain could be observed through parietal pleura riding on the costovertebral junctions. A 2-mm Kirschner wire was employed as an electrode, and the second and third thoracic sympathetic chains were electro cauterized. A thoracic drain was not used. The needling sites were only 2 mm in size and could be fixed without suture. For the patient, a small scar of this size means virtually no scar. The operative times were from 11 min to 81 min in bilateral ETS. Immediately and dramatic decrease in the sweat excretion in the palms was noted in all patients. The 95% patients were highly satisfied with the results. The commonest side effects were compensatory sweating. This procedure is recommended as the method of choice for the surgical treatments of palmar hyperhidrosis. PMID:11452523

Naruse, H; Moriyasu, K; Yokokawa, H; Ohkura, T; Kamio, Y; Suzuki, K; Suzuki, S; Kitami, A; Tanaka, H; Suzuki, T

2001-07-01

364

CVB: The Constrained Vapor Bubble 40 mm Capillary Experiment on the ISS  

NASA Technical Reports Server (NTRS)

Discuss the Constrained Vapor Bubble (CVB) 40mm Fin experiment on the ISS and how it aims to achieve a better understanding of the physics of evaporation and condensation and how they affect cooling processes in microgravity using a remotely controlled microscope and a small cooling device

Wayner, Peter C., Jr.; Kundan, Akshay; Plawsky, Joel

2013-01-01

365

1. East portal of Tunnel 3, view to west, 135mm ...  

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

1. East portal of Tunnel 3, view to west, 135mm lens. This tunnel was photographed to provide context, because even though somewhat enlarged, it illustrates the nature of the unlined hard rock tunnels typical of the original Central Pacific construction in 1868. - Central Pacific Transcontinental Railroad, Tunnel No. 3, Milepost 180.65, Cisco, Placer County, CA

366

The Reaction Mechanism of Paraoxon Hydrolysis by Phosphotriesterase from Combined QM/MM Simulations  

E-print Network

The Reaction Mechanism of Paraoxon Hydrolysis by Phosphotriesterase from Combined QM/MM Simulations Submitted to Biochemistry #12;1 The Reaction Mechanism of Paraoxon Hydrolysis by Phosphotriesterase from of Paraoxon Hydrolysis by Phosphotriesterase Page 1 of 57 ACS Paragon Plus Environment Submitted

Minnesota, University of

367

MM@MMaking Maths at Manchester General Course Information for the 2013 event.  

E-print Network

of five), led by a member of academic staff and supported by a postgraduate student. Lunch, is £65. Our information is that many schools and colleges that have the resources to do so may be willingMM@MMaking Maths at Manchester FACTSHEET General Course Information for the 2013 event. The course

Glendinning, Paul

368

MM@MMaking Maths at Manchester General Course Information for the 2014 event.  

E-print Network

by a member of academic staff and supported by postgraduate students. Lunch will be on campus and refreshments, is £70. Our information is that many schools and colleges that have the resources to do so mayMM@MMaking Maths at Manchester FACTSHEET General Course Information for the 2014 event. The course

Sidorov, Nikita

369

The three-dimensional structure of Saturn's E ring M.M. Hedman a,  

E-print Network

The three-dimensional structure of Saturn's E ring M.M. Hedman a, , J.A. Burns a,b , D.P. Hamilton Accepted 2 November 2011 Available online 19 November 2011 Keywords: Planetary rings Saturn, Rings Disks a b s t r a c t Saturn's diffuse E ring consists of many tiny (micron and sub-micron) grains of water

Hamilton, Douglas P.

370

3. West portal of Tunnel 26, view to northeast, 135mm ...  

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

3. West portal of Tunnel 26, view to northeast, 135mm lens. Note use of granite voussoirs and coping on this otherwise all-reinforced concrete structure. - Central Pacific Transcontinental Railroad, Tunnel No. 26, Milepost 133.29, Applegate, Placer County, CA

371

2. West portal of Snowshed 29, view to east, 135mm ...  

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

2. West portal of Snowshed 29, view to east, 135mm lens. Note the heavy timber frame, with battered posts to carry the tremendous snow loads of winter. - Central Pacific Transcontinental Railroad, Tunnel No. 41, Milepost 193.3, Donner, Placer County, CA

372

Evaluation of Offshore Wind Simulations with MM5 in the Japanese and Danish Coastal Waters  

E-print Network

Evaluation of Offshore Wind Simulations with MM5 in the Japanese and Danish Coastal Waters Teruo to the Danish ones. This is mainly due to the complexity of the wind climate strongly influenced by dynamical by more complex terrains and stronger solar radiation, compared to the Danish coastal waters. 2. Method

Heinemann, Detlev

373

Water Management EC Kumbur and MM Mench, The Pennsylvania State University, University Park, PA, USA  

E-print Network

, and molten carbonate fuel cell have been, or continue to be, developed. However, ubiquitous integration- ported on larger carbon particles (B45­90 mm diameter). The fuel (typically hydrogen (H2)) and oxidizer Wiley & Sons Inc. 828 #12;carbon diffusion medium (DM), which is also referred to as the gas diffusion

Mench, Matthew M.

374

A new 122 mm electromechanical drill for deep ice-sheet coring (DISC): 1. Design concepts  

Microsoft Academic Search

The Deep Ice Sheet Coring (DISC) drill, developed by Ice Coring and Drilling Services (ICDS) under contract with the US National Science Foundation, is an electromechanical drill designed to take 122 mm diameter ice cores to depths of 4000 m. The conceptual design of the DISC drill was developed in 2002\\/03 based on science requirements written by K. Taylor and

Alexander J. Shturmakov; Donald A. Lebar; William P. Mason; Charles R. Bentley

2007-01-01

375

MM5 Contrail Forecasting in Alaska Martin Stuefer, Xiande Meng and Gerd Wendler  

E-print Network

in humidity measurements at low temperature levels due to temperature dependence errors of the humidity sensor air. Algorithm input data are MM5 forecasted temperature and humidity values at defined pressure observation database. For comparison purposes we introduce a mean overlap (MO), which is a parameter

Stuefer, Martin

376

EEG source analysis of epileptiform activity using a 1 mm anisotropic hexahedra finite element head model  

Microsoft Academic Search

The major goal of the evaluation in presurgical epilepsy diagnosis for medically intractable patients is the precise reconstruction of the epileptogenic foci, preferably with non-invasive methods. This paper evaluates whether surface electroencephalography (EEG) source analysis based on a 1 mm anisotropic finite element (FE) head model can provide additional guidance for presurgical epilepsy diagnosis and whether it is practically feasible in

M. Rullmann; A. Anwander; M. Dannhauer; S. K. Warfield; F. H. Duffy; C. H. Wolters

2009-01-01

377

ExampleFaculty MembersArts As of , 2 , 7 (yyyy,mm dd)  

E-print Network

, Vocational Technical School etc. High School 1974 mm Final Status GraduatedDepartment of English, College porgram in English, ***** University xxxxx (United States) Master's program in Englsih, ***** University Studies, ***** University ***** State, U.S.A.6 Engaged in education and research at the Graduate School

Miyashita, Yasushi

378

IR & MM WAVES, VOL. 24, NO. 3, 2003 261 A FULL-HEIGHT WAVEGUIDE TO  

E-print Network

IR & MM WAVES, VOL. 24, NO. 3, 2003 261 A FULL-HEIGHT WAVEGUIDE TO THIN-FILM MICROSTRIP TRANSITION-film microstrip line, to full- height rectangular waveguide with better than 99% efficiency (VSWR 1.20) and 45 range. Keywords Radial probe, full-height waveguide to thin-film microstrip tran- sition, suspended

Chattopadhyay, Goutam

379

32. VERTICAL OSCILLATIONS, 3/4 VIEW, 7 NOVEMBER 1940, FROM 16MM ...  

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

32. VERTICAL OSCILLATIONS, 3/4 VIEW, 7 NOVEMBER 1940, FROM 16MM FILM SHOT PROFESSOR F.B. FARQUHARSON, UNIVERSITY OF WASHINGTON. (LABORATORY STUDIES ON THE TACOMA NARROWS BRIDGE, AT UNIVERSITY OF WASHINGTON (SEATTLE: UNIVERSITY OF WASHINGTON, DEPARTMENT OF CIVIL ENGINEERING, 1941) - Tacoma Narrows Bridge, Spanning Narrows at State Route 16, Tacoma, Pierce County, WA

380

Improved surface quality of anisotropically etched silicon {111} planes for mm-scale integrated optics  

E-print Network

We have studied the surface quality of millimeter-scale optical mirrors produced by etching CZ and FZ silicon wafers in potassium hydroxide to expose the $\\{111\\}$ planes. We find that the FZ surfaces have four times lower noise power at spatial frequencies up to $500\\, {mm}^{-1}$. We conclude that mirrors made using FZ wafers have higher optical quality.

Cotter, J P; Kraft, M; Hinds, E A

2013-01-01

381

pH Dependent Transitions in Xanthorhodopsin  

PubMed Central

Xanthorhodopsin (XR), the light-driven proton pump of the halophilic eubacterium Salinibacter ruber, exhibits substantial homology to bacteriorhodopsin (BR) of archaea and proteorhodopsin (PR) of marine bacteria, but unlike them contains a light-harvesting carotenoid antenna, salinixanthin, as well as retinal. We report here the pH dependent properties of XR. The pKa of the retinal Schiff base is as high as in BR, i.e., ? 12.4. Deprotonation of the Schiff base and the ensuing alkaline denaturation causes large changes in the absorption bands of the carotenoid antenna, which lose intensity and become broader making the spectrum similar to that of salinixanthin not bound to XR. A small red shift of the retinal chromophore band and increase of its extinction, as well as the pH dependent amplitude of the M intermediate indicate that in detergent-solubilized XR the pKa of the Schiff base counter-ion and proton acceptor is about 6 (compared to 2.6 in BR, and 7.5 in PR). The protonation of the counter-ion is accompanied by a small blue shift of the carotenoid absorption bands. The pigment is stable in the dark upon acidification to pH 2. At pH < 2 a transition to a blue shifted species absorbing around 440 nm occurs, accompanied by loss of resolution of the carotenoid absorption bands. At pH < 3 illumination of XR with continuous light causes accumulation of long-lived photoproducts(s) with an absorption maximum around 400 nm. The photocycle of XR was examined between pH 4 and 10 in solubilized samples. The pH dependence of recovery of the initial state slows at both acid and alkaline pH, with pKa’s of 6.0 and 9.3. The decrease in the rates with pKa 6.0 is apparently caused by protonation of the counter-ion and proton acceptor while that at high pH reflects the pKa of the internal proton donor, Glu94, at the times in the photocycle when this group equilibrates with the bulk. PMID:16649816

Imasheva, Eleonora S.; Balashov, Sergei P.; Wang, Jennifer M.; Lanyi, Janos K.

2009-01-01

382

Ileal pH in cystic fibrosis.  

PubMed

In cystic fibrosis jejunal hyperacidity has an adverse effect on lipid digestion. It is not known whether hyperacidity extends to the ileum. We have studied pH through the whole length of the small bowel in 42 normal and 6 cystic fibrosis subjects by means of pH-sensitive radiotelemetry capsules. In cystic fibrosis subjects the time spent below pH 6.0 was significantly greater during the 1st h in the small bowel than in normal subjects. In the rest of the small bowel the pH remained above 6.0 in both groups. The recordings in the cystic fibrosis group did not show the clear distinction between ileum and colon which is seen in normal subjects. In cystic fibrosis low pH conditions are confined to the proximal small intestine. There is adequate time at optimal pH in the small bowel for dissolution of enzyme supplements and assimilation of nutrients. PMID:3164499

Gilbert, J; Kelleher, J; Littlewood, J M; Evans, D F

1988-01-01

383

Manufacturing and optical testing of 800 mm lightweight all C/SiC optics  

NASA Astrophysics Data System (ADS)

Owing to its high specific stiffness and high thermal stability, silicon carbide is one of the materials most suitable for large space-borne optics. Technologies for accurate optical measurements of large optics in the vacuum or cryogenic conditions are also indispensable. Within the framework of the large SiC mirror study program led by JAXA, we manufactured an 800-mm-diameter lightweight telescope, all of which is made of HB-Cesic, a new type of carbon-fiber-reinforced silicon carbide (C/SiC) material developed jointly by ECM, Germany and MELCO, Japan. We first fabricated an 800-mm HB-Cesic primary mirror, and measured the cryogenic deformation of the mirror mounted on an HB-Cesic optical bench in a liquid-helium chamber. We observed the cryo-deformation of 110 nm RMS at 18 K with neither appreciable distortion associated with the mirror support nor significant residual deformation after cooling. We then integrated the primary mirror and a high-order aspheric secondary mirror into a telescope. To evaluate its optical performance, we established a measurement system, which consists of an interferometer in a pressure vessel mounted on a 5-axis adjustable stage, a 900-mm auto-collimating flat mirror, and a flat mirror stand with mechanisms of 2-axis tilt adjustment and rotation with respect to the telescope optical axis. We installed the telescope with the measurement system into the JAXA 6-m chamber and tested them at a vacuum pressure to verify that the system has a sufficiently high tolerance against vibrations in the chamber environment. Finally we conducted a preliminary study of sub-aperture stitching interferometry, which is needed for telescopes of our target missions in this study, by replacing the 900-mm flat mirror with a rotating 300-mm flat mirror.

Kaneda, Hidehiro; Naitoh, Masataka; Nakagawa, Takao; Imai, Tadashi; Katayama, Haruyoshi; Suganuma, Masahiro; Tange, Yoshio; Sato, Ryota; Enya, Keigo; Kotani, Masaki; Maruyama, Kenta; Onaka, Takashi; Kokusho, Takuma

2013-09-01

384

Hemodynamics of various designs of 19 mm pericardial aortic valve bioprosthesis.  

PubMed

The hemodynamics of five designs of 19 mm pericardial aortic valve bioprostheses were examined in 47 resting patients by Doppler echocardiography. The salient differences among the five designs are that valve leaflets are mounted inside the support frame in one (the Carpentier-Edwards valve, evaluated in 4 patients) and outside the frame in the other four (the Ionescu-Shiley (16 patients), Mitroflow (4), Bioflo (8) and Labcor-Santiago (15)); and that two models have either total (Bioflo) or partial (Labcor-Santiago) protective pericardial sheaths on the stent, while the other three do not. The hemodynamic parameters determined included transvalvular pressure drop, valve area, left ventricular outflow tract diameter, subvalvular/valvular velocity ratio and subvalvular/valvular velocity-time integral ratio. There were no significant differences among the various valves as regards left ventricular outflow tract diameter, subvalvular/valvular velocity ratio or subvalvular/valvular velocity-time integral ratio. Negative correlation between left ventricular outflow tract diameter and subvalvular velocity (r = -0.66, P < 0.001) confirmed the need to correct for prevalvular velocities when using the Bernouilli equation to calculate the pressure drop across small pericardial aortic valve bioprostheses. The Bioflo design caused significantly greater pressure drops (peak 38.3 +/- 8.3 mmHg, mean 24.6 +/- 4.8 mmHg) and smaller areas (0.82 +/- 0.17 cm2) than the Ionescu-Shiley (20.3 +/- 5.6 and 11.7 +/- 3.8 mmHg, 1.19 +/- 5.3 and 10.1 +/- 3.1 mmHg, 1.27 +/- 0.12 cm2) valves. PMID:8664021

González-Juanatey, J R; García-Acuña, J M; Vega Fernandez, M; Amaro Cendón, A; Castelo Fuentes, V; García-Bengoechea, J B; Gil de la Peña, M

1996-01-01

385

Advances in QM/MM Simulations for Organic and Enzymatic Reactions  

PubMed Central

CONSPECTUS Application of combined quantum and molecular mechanical (QM/MM) methods focuses on predicting activation barriers and the structures of stationary points for organic and enzymatic reactions. Characterization of the factors that stabilize transition structures in solution and in enzyme active sites provides a basis for design and optimization of catalysts. Continued technological advances allowed expansion from prototypical cases to mechanistic studies featuring detailed enzyme and condensed-phase environments with full integration of the QM calculations and configurational sampling. This required improved algorithms featuring fast QM methods, advances in computing changes in free energies including free-energy perturbation (FEP) calculations, and enhanced configurational sampling. In particular, the present Account highlights development of the PDDG/PM3 semiempirical QM method, computation of multidimensional potentials of mean force (PMF), incorporation of on-the-fly QM in Monte Carlo (MC) simulations, and a polynomial quadrature method for efficient modeling of proton-transfer reactions. The utility of this QM/MM/MC/FEP methodology is illustrated for a variety of organic reactions including substitution, decarboxylation, elimination, and pericyclic reactions. Comparison with experimental kinetic results on medium effects has verified the accuracy of the QM/MM approach in the full range of solvents from hydrocarbons to water to ionic liquids. Corresponding results from ab initio and density functional theory (DFT) methods with continuum-based treatments of solvation reveal deficiencies, particularly for protic solvents. Also summarized in this Account are three specific QM/MM applications to biomolecular systems: (1) a recent study that clarified the mechanism for the reaction of 2-pyrone derivatives catalyzed by macrophomate synthase as a tandem Michael-aldol sequence rather than a Diels-Alder reaction; (2) elucidation of the mechanism of action of fatty acid amide hydrolase (FAAH), an unusual Ser-Ser-Lys proteolytic enzyme; and, (3) the construction of enzymes for Kemp elimination of 5-nitrobenzisoxazole that highlights the utility of QM/MM in the design of artificial enzymes. PMID:19728702

2010-01-01

386

[Km 100 to 1000 mM (17)] and to S. cerevisiae hexose transporters' apparent affinity for glucose  

E-print Network

[Km 100 to 1000 mM (17)] and to S. cerevisiae hexose transporters' apparent affinity for glucose [Km 1000 to 10,000 mM (19)]. Therefore, the cellodextrin transport systems should more effec- tively constant (Ki) of cellobiose 19 to 410 mM (20)]. Withlittleoptimization,yeastexpressingcdt-1and gh1

Severson, David

387

Mississippi State Physics Labs: pH and pH Indicators  

NSDL National Science Digital Library

This item is an introductory lab that examines heat and energy. In the lab, students measure the pH of various chemicals using different pH indicators. Materials are inexpensive and readily available. This item is part of a larger collection of online physics labs by the authors.

Ferguson, Joe; Denson, Jack

2009-12-06

388

Andrew A. Shapiro, Ph.D. Ph.D. Materials Science and Engineering  

E-print Network

Andrew A. Shapiro, Ph.D. EDUCATION Ph.D. Materials Science and Engineering University of California-SiO2." M.S. Materials Science and Engineering University of California, Los Angeles, 1989 Thesis Materials Science and Engineering 2000- 2005 Lecturer - Materials Science and Engineering 1998- 2000 Co

Mease, Kenneth D.

389

Differential genotoxicity of diphenyl diselenide (PhSe)2 and diphenyl ditelluride (PhTe)2  

PubMed Central

Organoselenium compounds have been pointed out as therapeutic agents. In contrast, the potential therapeutic aspects of tellurides have not yet been demonstrated. The present study evaluated the comparative toxicological effects of diphenyl diselenide (PhSe)2 and diphenyl ditelluride (PhTe)2 in mice after in vivo administration. Genotoxicity (as determined by comet assay) and mutagenicicity were used as end-points of toxicity. Subcutaneous administration of high doses of (PhSe)2 or (PhTe)2 (500 µmol/kg) caused distinct genotoxicity in mice. (PhSe)2 significantly decreased the DNA damage index after 48 and 96 h of its injection (p < 0.05). In contrast, (PhTe) caused a significant increase in DNA damage (p < 0.05) after 48 and 96 h of intoxication. (PhSe)2 did not cause mutagenicity but (PhTe)2 increased the micronuclei frequency, indicating its mutagenic potential. The present study demonstrated that acute in vivo exposure to ditelluride caused genotoxicity in mice, which may be associated with pro-oxidant effects of diphenyl ditelluride. In addition, the use of this compound and possibly other related tellurides must be carefully controlled. PMID:24711962

Meinerz, Daiane Francine; Allebrandt, Josiane; Mariano, Douglas O.C.; Waczuk, Emily P.; Soares, Felix Antunes

2014-01-01

390

Ph.D SCHOOL DIRETTORE Ph.D. Programme MAIL TO 1.1 Prehistoric Archaeology  

E-print Network

and Genetics 9.5 Genetics and Molecular Biology 9.6 Experimental Medicine 9.7 Cell Techonology Sciences 9 Molecular Biology and Medicine #12;Appendix 1 Ph.D SCHOOL DIRETTORE Ph.D. Programme MAIL TO 13.1 Philology.3 Modern Philology, Linguistics, and Literatures 13.4 French Studies 13.5 Literatures in English 13.6 Greek

Di Pillo, Gianni

391

Exchangeable hydrogen explains the pH of spodosol Oa horizons  

USGS Publications Warehouse

The chemistry of extremely acid Oa horizons does not conform to traditional pH, Al, and base saturation relationships. Results from two separate studies of northeastern U.S. forested soils were used to investigate relationships between pH in water or dilute salt solutions and other soil characteristics. In Oa horizons with pH below 4, soil pH in dilute CaCl2 solution was correlated with exchangeable H+ measured either by titration (r = -0.88, P = 0.0001, n = 142) or by electrode (r = -0.89, P = 0.0001, n = 45). Exchangeable H+ expressed as a percentage of the cation-exchange capacity (CEC) was linear with pH and showed similar slopes for data from both studies. For all samples, pHw = 4.21 - 1.80 x H+/CEC (R2 = 0.69, n = 194). The reciprocal of the H+/CEC ratio is base saturation with Al added to the bases. Because of the low pH, exchangeable Al does not appear to behave as an acid. Exchangeable H+ remains an operationally defined quantity because of the difficulty in separating exchange and hydrolysis reactions. In a variety of neutral-salt extractants, concentration of H+ were correlated with 0.1 M BaCl2-exchangeable H+ (r > 0.91, P = 0.0001, n = 26) regardless of the strength of the extract. Nine successive extractions with 0.33 mM CaCl2 removed more H+ than was removed by single batch extractions with either 1 M KCl or 0.1 M BaCl2 (average H+ of 70, 43, and 49 mmol kg-1, respectively for 26 samples). The data showed little difference in the chemical behavior of Oa horizons from a variety of geographical sites and vegetation types.

Ross, D.S.; David, M.B.; Lawrence, G.B.; Bartlett, R.J.

1996-01-01

392

Seeding-dependent maturation of beta2-microglobulin amyloid fibrils at neutral pH.  

PubMed

Beta2-microglobulin (beta2-m) is a major component of amyloid fibrils deposited in patients with dialysis-related amyloidosis. Recent studies have focused on the mechanism by which amyloid fibrils are formed under physiological conditions, which had been difficult to reproduce quantitatively. Yamamoto et al. (Yamamoto, S., Hasegawa, K., Yamaguchi, I., Tsutsumi, S., Kardos, J., Goto, Y., Gejyo, F. & Naiki, H. (2004) Biochemistry 43, 11075-11082) showed that a combination of seed fibrils prepared under acidic conditions and a low concentration of sodium dodecyl sulfate below its critical micelle concentration enabled extensive fibril formation at pH 7.0. Here, we found that repeated self-seeding at pH 7.0 with fibrils formed at the same pH causes a marked acceleration of growth, indicating the maturation of fibrils. The observed maturation can be simulated by assuming the existence of two types of fibrils with different growth rates. Importantly, some mutations of beta2-m or the addition of a low concentration of urea, both destabilizing the native conformation, were not enough to extend the fibrils at pH 7.0, and a low concentration of sodium dodecyl sulfate (i.e. 0.5 mM) was essential. Thus, even though the first stage fibrils in patients are unstable and require stabilizing factors to remain at neutral pH, they can adapt to a neutral pH with repeated self-seeding, implying a mechanism of development of amyloid deposition after a long latent period in patients. PMID:15659393

Kihara, Miho; Chatani, Eri; Sakai, Miyo; Hasegawa, Kazuhiro; Naiki, Hironobu; Goto, Yuji

2005-03-25

393

Noninvasive NIR measurement of tissue pH to assess hemorrhagic shock in swine  

NASA Astrophysics Data System (ADS)

Body-worn noninvasive physilogical sensors are needed to continuously monitor soldiers for hemorrhage and to provide real-time information for minimally skilled medics to treat the injured. In the hospital intramucosal pHi of the gut is used to monitor shock and its treatment. We hypothesize that abdominal wall muscle (AWM) pH can be measured noninvasively using near infrared (NIR) spectroscopy and partial least squares analysis (PLS) and will correlate with pHi. METHODS: AWM pH was measured with microelectrodes and gastric pHi was measured with a tonometric catheter simultaneously while NIR spectra were collected using prototype LED spectrometers placed on the pig's flanks. Animals were subject to hemorrhagic shock at 45 mm Hg for 45 minutes, then resuscitated with blood and lactated ringers. Relationships between electrode pH, pHi and NIR spectra were developed using PLS with cross validation. RESULTS: NIR spectral changes noninvasively acquired through the skin were shown to be from the muscle, not from changes in skin blood flow. Trending ability (R2) model accuracy (RMSD), and relative error were calculated for individual pigs. Using electrode pH as the reference, average R2 was 0.88 with a predicted accuracy of 0.17 pH units, a 9.3% relative error. Slightly degraded results were observed when pHi was used as a reference. CONCLUSIONS: NIR measurement of tissue pH can be used to noninvasively monitor for shock and guide its treatment in a swine model. These measurements correlate with gastric pHi, a clinically accepted measure of shock, providing an approach to develop similar methodology for humans.

Soller, Babs R.; Zhang, Songbiao; Micheels, Ronald H.; Puyana, Juan C.

1999-07-01

394

Intracellular pH regulation in cultured renal proximal tubule cells in different stages of maturation.  

PubMed

This study examines the ontogeny of cellular pH regulation in renal proximal tubule cells (RPTC). RPTC from 8- to 40-day-old Sprague-Dawley rats (RPTC-8 to RPTC-40) were studied after 48 h of primary culture. Intracellular pH (pHi) was measured by quantitative fluorescence microscopy using 2',7'-bis(carboxyethyl)-5(6)-carboxyfluorescein. Recordings were made under basal conditions and after imposing a cytoplasmic alkalosis and acidosis using 15 mM NH4+ salt. The net recovery rate (dpHi/dt) from intracellular acidosis increases significantly between 10 and 12 days of age from 0.39 +/- 0.04 to 0.54 +/- 0.06 pH units/min (P < 0.05, n = 10 vs. 6). This increase can be completely accounted for by an increase in the rate of amiloride (100 microM)-inhibitable Na(+)-H+ exchange (0.29 +/- 0.04 vs. 0.42 +/- 0.05 pH units/min, P < 0.05, n = 6 vs. 6). The rate of Na(+)-H+ exchange increases similarly in RPTC-10 and RPTC-40 when the transmembrane Na+ gradient is increased by Na+ depleting the cells (48 and 49%, respectively). The amiloride-insensitive recovery is Na+ independent and insensitive to 4-acetamido-4'-isothiocyanostilbene-2-2'-disulfonic acid (SITS, 500 microM) (range 0.08-0.14 pH units/min). The net recovery rate from intracellular alkalosis is significantly lower in RPTC-10 than in RPTC-40 (0.16 +/- 0.02 vs. 0.28 +/- 0.02 pH units/min, P < 0.01, n = 4 vs. 5). SITS (500 microM) inhibits the recovery by 27 +/- 8 and 26 +/- 9%, respectively, whereas amiloride has no effect.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1329559

Ekblad, H; Aperia, A; Larsson, S H

1992-10-01

395

PhET Teacher Activities: Hooke's Law  

NSDL National Science Digital Library

This two-hour activity for high school physics was created to accompany the PhET simulation Masses & Springs. In the first lesson, students will use the simulation to explore how displacement of a spring is mathematically related to the load applied to it. In the next day's exploration, learners analyze the energy of a mass oscillating on a spring by observing distribution and transfer of kinetic, elastic potential, and gravitational potential energy. Materials include learning goals, explicit directions for use of the simulation, homework problems, and answer key. The spring motion simulation (which is required to complete this activity) is available from PhET at: Masses & Springs. This lesson is part of the PhET (Physics Education Technology Project), a large collection of free interactive science simulations.

2012-09-25

396

The Effect of Crystallizing and Non-crystallizing Cosolutes on Succinate Buffer Crystallization and the Consequent pH Shift in Frozen Solutions  

SciTech Connect

To effectively inhibit succinate buffer crystallization and the consequent pH changes in frozen solutions. Using differential scanning calorimetry (DSC) and X-ray diffractometry (XRD), the crystallization behavior of succinate buffer in the presence of either (i) a crystallizing (glycine, mannitol, trehalose) or (ii) a non-crystallizing cosolute (sucrose) was evaluated. Aqueous succinate buffer solutions, 50 or 200 mM, at pH values 4.0 or 6.0 were cooled from room temperature to -25 C at 0.5 C/min. The pH of the solution was measured as a function of temperature using a probe designed to function at low temperatures. The final lyophiles prepared from these solutions were characterized using synchrotron radiation. When the succinic acid solution buffered to pH 4.0, in the absence of a cosolute, was cooled, there was a pronounced shift in the freeze-concentrate pH. Glycine and mannitol, which have a tendency to crystallize in frozen solutions, remained amorphous when the initial pH was 6.0. Under this condition, they also inhibited buffer crystallization and prevented pH change. At pH 4.0 (50 mM initial concentration), glycine and mannitol crystallized and did not prevent pH change in frozen solutions. While sucrose, a non-crystallizing cosolute, did not completely prevent buffer crystallization, the extent of crystallization was reduced. Sucrose decomposition, based on XRD peaks attributable to {beta}-D-glucose, was observed in frozen buffer solutions with an initial pH of 4.0. Trehalose completely inhibited crystallization of the buffer components when the initial pH was 6.0 but not at pH 4.0. At the lower pH, the crystallization of both trehalose dihydrate and buffer components was evident. When retained amorphous, sucrose and trehalose effectively inhibited succinate buffer component crystallization and the consequent pH shift. However, when trehalose crystallized or sucrose degraded to yield a crystalline decomposition product, crystallization of buffer was observed. Similarly, glycine and mannitol, two widely used bulking agents, inhibited buffer component crystallization only when retained amorphous. In addition to stabilizing the active pharmaceutical ingredient, lyoprotectants may prevent solution pH shift by inhibiting buffer crystallization.

Sundaramurthi, Prakash; Suryanarayanan, Raj (UMM)

2011-09-06

397

A Comparitive Evaluation of Sealing Ability, pH and Rheological Properties of Zinc Oxide Eugenol Sealer Combined with Different Antibiotics: An In Vitro Study  

PubMed Central

Aim: The objective of this study was to evaluate and compare the sealing ability, pH & viscosity of Zinc oxide eugenol sealer mixed with different antibiotics (Amoxicillin, Ciprofloxacin, Clindamycin and Doxycycline). Materials and Methods: Ninety single rooted anterior teeth were randomly divided into four experimental groups of 15 teeth each and 3 control groups of 10 each. Sealer-antibiotic combination was used as a sealer in experimental group. Teeth were sectioned longitudinally to assess linear dye penetration. pH and viscosity of the experimental groups were evaluated with Elico pH Meter and Brook Field Viscometer respectively. Results: (Amoxicillin+ ZOE) Group II and (Clindamycin + ZOE) Group IV have shown minimum linear dye leakage of 1.07mm & 1.22 mm respectively & (Ciprofloxacin + ZOE) Group III and (Doxycycline + ZOE) Group V 2.69 mm & 2.59 mm respectively. There was decrease in the viscosity of the experimental group. pH was found to be 8.55 for Group II sealer which was greater than control group. Conclusion: Amoxicillin and sealer combination can improve the success rate of endodontic therapy by enhancing the antimicrobial activity, alkaline environment and reducing apical microleakage. PMID:25584296

Sajjan, Girija S; Peddireddi, Suresh; Kumar, M. Sita Rama; Bhavana, V.; Raju, Sita Rama

2014-01-01

398

Effects of pH shifts, bile salts, and glucose on sporulation of Clostridium perfringens NCTC 8798.  

PubMed Central

The sporulation of Clostridium perfringens NCTC 8798 was studied after exposing vegetative cells to: pH values of 1.5 to 8.0 in fluid thioglycolate broth (for 2h) and then transferring them to Duncan-Strong (DS) sporulation medium; sodium cholate or sodium deoxycholate (0.3 to 6.5 mM) in DS medium; or Rhia-Solberg medium with 0.4% (wt/wt) starch, glucose, or both added at 0 to 55 mM. At pH 1.5, no culturable heat-resistant spores were formed. For cells exposed to pH 3.0, 4.0, 5.0, or 6.0, increases in heat-resistant spores were not seen until after a lag of 12 to 13 h, whereas the lag was only 2 to 3 h for cells exposed to pH 7.0 or 8.0. Maximal spore crops were produced after only 6 to 8 h for cells exposed to pH 7 or 8, but 16 to 18 h was required for production of maximal spore crops by cells exposed to the lower-pH media. The addition of sodium cholate (3.5 to 6.5 mM) to DS medium only slightly reduced the culturable heat-resistant spore count from 1.9 X 10(7) to 3 X 10(6)/ml. The addition of 1.8 mM or more sodium deoxycholate reduced the culturable heat-resistant spore count to less than 10/ ml. When either starch or glucose alone was added to Rhia-Solberg medium there was no production of culturable heat-resistant spores, but a combination of 0.4% (wt/wt) starch and 4.4 mM glucose yielded 6 X 10(5) spores/ml. The spore production remained at this level for glucose concentrations of 6 to 22 mM, but then declined to about 3 X 10(3) spores per ml at higher concentrations. PMID:6261681

Hickey, C S; Johnson, M G

1981-01-01

399

Effect of pH on the accumulation kinetics of pentachlorophenol in goldfish  

USGS Publications Warehouse

The kinetics of accumulation of pentachlorophenol (PCP) at various pH values were investigated to explore how pH-dependent accumulation might influence PCP toxicity. Goldfish (Carassius auratus ) were exposed to 5 mu g PCP/L in a static system buffered with 7.5 mM bicine or N,N-bis(2-hydroxyethyl)-2-aminoethane sulfonic acid (BES) at pH 7.0, 8.0, or 9.0. The amount of PCP in the fish, concentration of PCP in water, and the total amount of metabolites in the system were measured after exposure of fish from 1 to 96 hr. The distribution of PCP within the fish was altered by changes in the external pH. The pH-associated changes in distribution may have altered access of PCP to sites of metabolism, thereby altering the metabolic clearance. The pH-related changes in the pharmacokinetics of PCP resulted in a decrease in its bioconcentration factor with an increase in pH and account both for the decreased capacity of the fish to accumulated PCP and for its reduced LC50.

Stehly, G.R.; Hayton, W.L.

1990-01-01

400

Hydrogen-bond network and pH sensitivity in human transthyretin.  

PubMed

Transthyretin (TTR) is a tetrameric protein. TTR misfolding and aggregation are associated with human amyloid diseases. Dissociation of the TTR tetramer is believed to be the rate-limiting step in the amyloid fibril formation cascade. Low pH is known to promote dissociation into monomer and the formation of amyloid fibrils. In order to reveal the molecular mechanisms underlying pH sensitivity and structural stabilities of TTR, neutron diffraction studies were conducted using the IBARAKI Biological Crystal Diffractometer with the time-of-flight method. Crystals for the neutron diffraction experiments were grown up to 2.5 mm(3) for four months. The neutron crystal structure solved at 2.0 Å revealed the protonation states of His88 and the detailed hydrogen-bond network depending on the protonation states of His88. This hydrogen-bond network is involved in monomer-monomer and dimer-dimer interactions, suggesting that the double protonation of His88 by acidification breaks the hydrogen-bond network and causes the destabilization of the TTR tetramer. Structural comparison with the X-ray crystal structure at acidic pH identified the three amino acid residues responsible for the pH sensitivity of TTR. Our neutron model provides insights into the molecular stability related to amyloidosis. PMID:24121323

Yokoyama, Takeshi; Mizuguchi, Mineyuki; Nabeshima, Yuko; Kusaka, Katsuhiro; Yamada, Taro; Hosoya, Takaaki; Ohhara, Takashi; Kurihara, Kazuo; Tanaka, Ichiro; Niimura, Nobuo

2013-11-01

401

Hydrogen-bond network and pH sensitivity in human transthyretin  

PubMed Central

Transthyretin (TTR) is a tetrameric protein. TTR misfolding and aggregation are associated with human amyloid diseases. Dissociation of the TTR tetramer is believed to be the rate-limiting step in the amyloid fibril formation cascade. Low pH is known to promote dissociation into monomer and the formation of amyloid fibrils. In order to reveal the molecular mechanisms underlying pH sensitivity and structural stabilities of TTR, neutron diffraction studies were conducted using the IBARAKI Biological Crystal Diffractometer with the time-of-flight method. Crystals for the neutron diffraction experiments were grown up to 2.5?mm3 for four months. The neutron crystal structure solved at 2.0?Å revealed the protonation states of His88 and the detailed hydrogen-bond network depending on the protonation states of His88. This hydrogen-bond network is involved in monomer–monomer and dimer–dimer interactions, suggesting that the double protonation of His88 by acidification breaks the hydrogen-bond network and causes the destabilization of the TTR tetramer. Structural comparison with the X-ray crystal structure at acidic pH identified the three amino acid residues responsible for the pH sensitivity of TTR. Our neutron model provides insights into the molecular stability related to amyloidosis. PMID:24121323

Yokoyama, Takeshi; Mizuguchi, Mineyuki; Nabeshima, Yuko; Kusaka, Katsuhiro; Yamada, Taro; Hosoya, Takaaki; Ohhara, Takashi; Kurihara, Kazuo; Tanaka, Ichiro; Niimura, Nobuo

2013-01-01

402

Casein maps: effect of ethanol, pH, temperature, and CaCl2 on the particle size of reconstituted casein micelles.  

PubMed

Although conditions favoring casein micelle aggregation are well known, factors promoting the dissociation of the casein micelle are not fully understood. It was our objective to investigate the ethanol-induced dissociation of micellar casein as affected by temperature and a wide range of pH, along with the concentrations of calcium and casein. Two different concentrations of casein micelles were dispersed in imidazole buffer with 0 to 80% ethanol (vol/vol) and 2 and 10mM calcium. Apparent micelle size was determined by dynamic light scattering at 5, 30, and 60°C. In the absence of ethanol, casein precipitation occurred at pH 4.6 in imidazole buffer. Ten to forty percent ethanol promoted casein aggregation (>1,000 nm) and higher temperature (30 and 60°C) enhanced this effect. Higher ethanol concentrations at 50 to 80% induced the dissociation (<40 nm) of the casein micelle upon acidification (pH <5) and alkalization (pH>8) in imidazole buffer. In addition, higher concentrations of casein (0.25mg/mL) and calcium (20mM) caused the formation of larger aggregates (>1,000 nm) in the presence of ethanol when comparing with the initial lower concentrations of casein (0.1mg/mL) and calcium (2mM). Casein micelle dissociation can be achieved near the isoelectric pH by modifying the solvent composition and temperature. PMID:23200467

Ye, Ran; Harte, Federico

2013-02-01

403

Influence of pH, benzoic acid, glutathione, EDTA, 4-hexylresorcinol, and sodium chloride on the pressure inactivation kinetics of mushroom polyphenol oxidase.  

PubMed

Pressure inactivation of mushroom PPO was studied for pH values ranging from 4 to 8, and the effect of some antibrowning agents on the pressure stability of mushroom PPO at pH 6.5 was evaluated. pH reduction below 6.5 resulted in a lowered inactivation threshold pressure and an increase of the absolute value of the activation volume (or a decrease of the z(p) value), the latter two parameters reflecting the pressure dependency of the inactivation rate constant. An increase in pH from 6.5 to 8, on the other hand, did only marginally affect the pressure stability of the enzyme. Mushroom PPO at pH 6.5 was markedly sensitized toward pressure by the presence of 2.5 mM 4-hexylresorcinol and slightly stabilized by the presence of 5 mM EDTA. The presence of 5 mM glutathione, sodium chloride, or benzoic acid caused no significant alteration of the enzyme pressure stability. Only in the presence of 4-hexylresorcinol, significant changes of the activation volume and z(p) value were noticed. PMID:10552679

Weemaes, C A; Ludikhuyze, L R; Van den Broeck, I; Hendrickx, M E

1999-09-01

404

Microbiology Ph.D. Admissions Data -Fall 2012 Entering Class  

E-print Network

Microbiology Ph.D. Admissions Data - Fall 2012 Entering Class Admissions data for Biological and Biomedical Sciences can be found here. Ph.D. Degree Information Number of registered students, Fall 2012 19 Number of degrees awarded 2011-2012 4 Median years to Ph.D. 5.7 Percent of students awarded Ph.D. 94

405

Recommended Soil pH and Lime Requirement Tests  

Microsoft Academic Search

Soil pH is defined as the negative logarithm (base 10) of the H+ activity (moles per liter) in the soil solution. As the activity of H+ in the soil solution increases, the soil pH value decreases. Soils with pH values below pH 7 are referred to as \\

Donald Eckert; J. Thomas Sims

406

2011 Cecilia J. Hillard, PhD Douglas R. Campbell  

E-print Network

Roger W. Byhardt, MD Marlene D. Melzer-Lange, MD 2009 Owen W. Griffith, PhD Karen J. Marcdante, MD John Robert Montgomery, MD James Sebastian, MD 2005 William Hendee, PhD Jeffrey Kelly, PhD Jerry Taylor, Ph

407

A Deep 1.2 mm Map of the Lockman Hole North Field  

NASA Astrophysics Data System (ADS)

We present deep 1.2 mm continuum mapping of a 566 arcmin2 area within the Lockman Hole North (LHN) field, previously a target of the Spitzer Wide-Area Infrared Extragalactic survey and extremely deep 20 cm mapping with the Very Large Array, which we have obtained using the Max-Planck millimeter bolometer (MAMBO) array on the IRAM 30 m telescope. After filtering, our full map has an rms sensitivity ranging from 0.45 to 1.5 mJy beam-1, with an average of 0.75 mJy beam-1. Using the pixel flux distribution (PFD) in a map made from our best data, we determine the shape, normalization, and approximate flux density cutoff for 1.2 mm number counts well below our nominal sensitivity and confusion limits. After validating our full data set through comparison with this map, we successfully detect 41 1.2 mm sources with signal-to-noise ratio (S/N) > 4.0 and S 1.2 mm ~= 2-5 mJy. We use the most significant of these detections to directly determine the integral number counts down to 1.8 mJy, which are consistent with the results of the PFD analysis. Ninety-three percent of our 41 individual detections have 20 cm counterparts, 49% have Spitzer/MIPS 24 ?m counterparts, and one may have a significant Chandra X-ray counterpart. We resolve ~= 3% of the cosmic infrared background (CIB) at 1.2 mm into significant detections and directly estimate a 0.05 mJy faint-end cutoff for the counts that is consistent with the full intensity of the 1.2 mm CIB. The median redshift of our 17 detections with spectroscopic or robust photometric redshifts is z median = 2.3, and rises to z median = 2.9 when we include redshifts estimated from the radio/far-infrared spectral index. By using a nearest neighbor and angular correlation function analysis, we find evidence that our S/N > 4.0 detections are clustered at the 95% confidence level.

Lindner, R. R.; Baker, A. J.; Omont, A.; Beelen, A.; Owen, F. N.; Bertoldi, F.; Dole, H.; Fiolet, N.; Harris, A. I.; Ivison, R. J.; Lonsdale, C. J.; Lutz, D.; Polletta, M.

2011-08-01

408

The W43-MM1 mini-starburst ridge, a test for star formation efficiency models  

NASA Astrophysics Data System (ADS)

Context. Star formation efficiency (SFE) theories are currently based on statistical distributions of turbulent cloud structures and a simple model of star formation from cores. They remain poorly tested, especially at the highest densities. Aims: We investigate the effects of gas density on the SFE through measurements of the core formation efficiency (CFE). With a total mass of ~2 × 104 M?, the W43-MM1 ridge is one of the most convincing candidate precursors of Galactic starburst clusters and thus one of the best places to investigate star formation. Methods: We used high-angular resolution maps obtained at 3 mm and 1 mm within the W43-MM1 ridge with the IRAM Plateau de Bure Interferometer to reveal a cluster of 11 massive dense cores, and, one of the most massive protostellar cores known. A Herschel column density image provided the mass distribution of the cloud gas. We then measured the "instantaneous" CFE and estimated the SFE and the star formation rate (SFR) within subregions of the W43-MM1 ridge. Results: The high SFE found in the ridge (~6% enclosed in ~8 pc3) confirms its ability to form a starburst cluster. There is, however, a clear lack of dense cores in the eastern part of the ridge, which may be currently assembling. The CFE and the SFE are observed to increase with volume gas density, while the SFR per free fall time steeply decreases with the virial parameter, ?vir. Statistical models of the SFR may describe the outskirts of the W43-MM1 ridge well, but struggle to reproduce its inner part, which corresponds to measurements at low ?vir. It may be that ridges do not follow the log-normal density distribution, Larson relations, and stationary conditions forced in the statistical SFR models. Final IRAM/PdBI FITS cube is only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/570/A15

Louvet, F.; Motte, F.; Hennebelle, P.; Maury, A.; Bonnell, I.; Bontemps, S.; Gusdorf, A.; Hill, T.; Gueth, F.; Peretto, N.; Duarte-Cabral, A.; Stephan, G.; Schilke, P.; Csengeri, T.; Nguyen Luong, Q.; Lis, D. C.

2014-10-01

409

A emissão em 8mm e as bandas de Merrill-Sanford em estrelas carbonadas  

NASA Astrophysics Data System (ADS)

Estrelas carbonadas possuem bandas moleculares em absorção no visível e, no infravermelho (IR) as principais características espectrais se devem a emissão de grãos. Recentemente foi detectada a presença de bandas de SiC2 (Merrill-Sanford, MS) em emissão sendo atribuída à presença de um disco rico em poeira. Neste trabalho analisamos uma amostra de 14 estrelas carbonadas, observadas no telescópio de 1.52 m do ESO em 4 regiões espectrais diferentes, a fim de detectar as bandas de MS em emissão. Nossa amostra é composta de estrelas que apresentam além da emissão em 11.3 mm, outra em 8 mm. Esta última emissão, não usual nestes objetos, tem sido atribuída ou a moléculas de C2H2, ou a um composto sólido ainda indefinido. A detecção de emissões de MS e aquelas no IR, simultaneamente, revelaria um cenário mais complexo que o habitualmente esperado para os ventos destes objetos. No entanto como primeiro resultado, verificamos que as bandas de Merrill-Sanford encontram-se em absorção, não revelando nenhuma conexão com a emissão a 8 mm. Assim, temos duas hipóteses: (a) a emissão a 8 mm se deve à molécula C2H2 ou (b) essa emissão é resultado da emissão térmica de grãos. Testamos a segunda hipótese modelando a amostra com grãos não-homogêneos de SiC e quartzo, o qual emite em aproximadamente 8mm. Este grão seria produzido em uma fase evolutiva anterior a das carbonadas (estrelas S) e por terem uma estrutura cristalina são destruídos apenas na presença de campos de radiação ultravioleta muito intensos. Os modelos para os envoltórios utilizam o método de Monte Carlo para descrever o problema do transporte da radiação. As conclusões deste trabalho são: (1) as bandas de Merrill-Sanford se encontram em absorção, sugerindo um cenário usual para os ventos das estrelas da amostra; (2) neste cenário, a emissão em 8 mm seria resultado de grãos de quartzo com mantos de SiC, indicando que o quartzo poderia sobreviver a fase evolutiva S.

de Mello, A. B.; Lorenz-Martins, S.

2003-08-01

410

Station-based verification of qualitative and quantitative MM5 precipitation forecasts over Northwest Himalaya (NWH)  

NASA Astrophysics Data System (ADS)

Weather forecasts by any forecast system are verified using either distributions-oriented or measures-oriented forecast verification measures. Both the forecast verification schemes represent different aspects of the forecast quality, and advantages of them can be utilized to get better insight and to identify particular strengths (deficiencies) in the forecast performance of any forecast system. Keeping this in view, multi-faced verification (binary and continuous) of quantitative precipitation forecasts for consecutive 3 days by a Regional Meso-scale Weather Simulation Model (MM5 Model) has been carried out to get complete insight into its performance. The MM5 model forecasts at 10-km resolution for 792 days of six winters (winter 2003/2004 to winter 2008/2009) are compared with the observational data of six stations in the complex topography of Northwest Himalaya (NWH) in India. The model forecasts are verified using binary categorical forecast verification measures such as Probability of Detection, False Alarm Rate, Miss Rate, Correct Non-occurrence, Critical Success Index and Percent correct, and continuous forecast verification measures such as Mean Absolute Error (MAE) and Root Mean Square Error (RMSE). BIAS is computed to know over-forecast/under-forecast tendency of a precipitation day (PT day) by the MM5 model. MAE (RMSE) of the MM5 model is computed separately for all days, PT days and no precipitation days (NPT days). MAE (RMSE) of PT days is found to be relatively larger as compared to NPT days and all days. These findings indicate that MAE (RMSE) computed separately for all days, PT days and NPT days provides better insight into the performance of the MM5 model. Results also suggest that the MM5 model shows reasonably good performance for binary forecasts (PT days/NPT days) for day 1 (0-24 h), day 2 (24-48 h) and day 3 (48-72 h). However, large errors are seen in predicting the observed precipitation amount of PT days over NWH.

Singh, Dan; Bhutiyani, M. R.; Ram, Tule

2014-08-01

411

Electrochemiluminescent pH sensor measured by the emission potential of TiO2 nanocrystals and its biosensing application.  

PubMed

This work reports for the first time a potential-based nano-electrochemiluminescent (ECL) pH sensor, using anatase TiO2 nanocrystals (NCs) as the ECL probe. The first ECL peak potential of the TiO2 NCs shifted negatively with increasing pH, showing a linear range from -0.47 V (vs Ag/AgCl) at pH 3 to -1.06 V at pH 10. This phenomenon was attributed to the absorption of 'potential-determining ions' of OH(-) on the surface of TiO2 NCs, leading to larger impedance of the electron injection. Other common 'potential-determining ions', such as phosphate, induced a slight potential shift of 0.03 V at a concentration of 0.1 M. Using urease as an enzyme model, a urea biosensor was developed by the simultaneous modification of urease and TiO2 NCs on indium-tin oxide (ITO) electrodes. The biosensor, measured on the basis of the pH increase caused by the enzyme catalysis reaction, had a linear range of 0.01-2.0 mM, with a potential shift of 0.175 V. The as-prepared pH sensor, which has simple construction procedures and acceptable sensitivity and selectivity, may provide new avenues for the construction of ECL bioanalytical methodologies. Copyright © 2014 John Wiley & Sons, Ltd. PMID:24802560

Liu, Xuan; Wang, Nianyue; Zhao, Wei; Jiang, Hui

2015-02-01

412

The effect of pH and ADP on ammonia affinity for human glutamate dehydrogenases.  

PubMed

Glutamate dehydrogenase (GDH) uses ammonia to reversibly convert ?-ketoglutarate to glutamate using NADP(H) and NAD(H) as cofactors. While GDH in most mammals is encoded by a single GLUD1 gene, humans and other primates have acquired a GLUD2 gene with distinct tissue expression profile. The two human isoenzymes (hGDH1 and hGDH2), though highly homologous, differ markedly in their regulatory properties. Here we obtained hGDH1 and hGDH2 in recombinant form and studied their Km for ammonia in the presence of 1.0 mM ADP. The analyses showed that lowering the pH of the buffer (from 8.0 to 7.0) increased the Km for ammonia substantially (hGDH1: from 12.8 ± 1.4 mM to 57.5 ± 1.6 mM; hGDH2: from 14.7 ± 1.6 mM to 62.2 ± 1.7 mM), thus essentially precluding reductive amination. Moreover, lowering the ADP concentration to 0.1 mM not only increased the K0.5 [NH4 (+)] of hGDH2, but also introduced a positive cooperative binding phenomenon in this isoenzyme. Hence, intra-mitochondrial acidification, as occurring in astrocytes during glutamatergic transmission should favor the oxidative deamination of glutamate. Similar considerations apply to the handling of glutamate by the proximal convoluted tubules of the kidney during systemic acidosis. The reverse could apply for conditions of local or systemic hyperammonemia or alkalosis. PMID:23420347

Zaganas, Ioannis; Paj?cka, Kamilla; Wendel Nielsen, Camilla; Schousboe, Arne; Waagepetersen, Helle S; Plaitakis, Andreas

2013-06-01

413

The Influence of pH on the Oxygen Isotope Composition of Calcium Carbonate  

NASA Astrophysics Data System (ADS)

Oxygen isotope fractionation between calcium carbonate and water is temperature-dependent and can therefore be used as a paleothermometer. Although oxygen isotope fractionation is expected from principles of equilibrium isotopic partitioning, the temperature-dependence remains uncertain because other factors, such as slow exchange between dissolved inorganic carbon (DIC) species and water, can obscure the temperature signal. Oxygen isotopic equilibrium between aqueous solution and calcium carbonate includes two distinct equilibria: equilibrium of the DIC species in solution (i.e., CO2(aq), H2CO3, HCO3-, and CO32-) with water, and equilibrium between the dissolved inorganic carbon with the precipitated carbonate. To isolate kinetic isotope effects that arise at the mineral-solution interface, isotopic equilibrium among DIC species must be maintained. This can be accomplished by dissolving the enzyme carbonic anhydrase (CA) into the solution, thereby reducing the time required for isotopic equilibration between DIC species by approximately two orders of magnitude between pH 7.7 and 9.3. We conduct calcite growth experiments aimed specifically at measuring the pH-dependence of kinetic oxygen isotope effects during precipitation of calcite. We precipitated calcite from aqueous solution at a constant pH and controlled supersaturation over the pH range 7.7-9.3. For each experiment, a gas mixture of N2 and CO2 is constantly bubbled through a beaker containing ~1300 mL of solution (30 mM CaCl2 + 5 mM NH4Cl + 0.1 mM SrCl2). As CO2 from the gas dissolves into solution, calcite crystals grow on the beaker walls. The pH of the solution is maintained by use of an autotitrator with NaOH as the titrant. We control the temperature, pH, the pCO2 of the gas inflow, and the gas inflow rate, and monitor the total alkalinity, the pCO2 of the gas outflow, and the amount of NaOH added. A constant crystal growth rate of ~1.6 mmol/m2/hr is maintained over all experiments. We will present results from this set of experiments and discuss kinetic oxygen isotope effects in the context of a recently-developed ion-by-ion growth model of calcite.

Hunt, J. D.; Watkins, J. M.; Ryerson, F. J.; DePaolo, D. J.

2013-12-01

414

Plasma pH does not influence the cerebral metabolic ratio during maximal whole body exercise  

PubMed Central

Exercise lowers the cerebral metabolic ratio of O2 to carbohydrate (glucose + 1/2 lactate) and metabolic acidosis appears to promote cerebral lactate uptake. However, the influence of pH on cerebral lactate uptake and, in turn, on the cerebral metabolic ratio during exercise is not known. Sodium bicarbonate (Bicarb, 1 m; 350–500 ml) or an equal volume of normal saline (Sal) was infused intravenously at a constant rate during a ‘2000 m’ maximal ergometer row in six male oarsmen (23 ± 2 years; mean ± s.d.). During the Sal trial, pH decreased from 7.41 ± 0.01 at rest to 7.02 ± 0.02 but only to 7.36 ± 0.02 (P < 0.05) during the Bicarb trial. Arterial lactate increased to 21.4 ± 0.8 and 32.7 ± 2.3 mm during the Sal and Bicarb trials, respectively (P < 0.05). Also, the arterial–jugular venous lactate difference increased from –0.03 ± 0.01 mm at rest to 3.2 ± 0.9 mm (P < 0.05) and 3.4 ± 1.4 mm (P < 0.05) following the Sal and Bicarb trials, respectively. Accordingly, the cerebral metabolic ratio decreased equally during the Sal and Bicarb trials: from 5.8 ± 0.6 at rest to 1.7 ± 0.1 and 1.8 ± 0.2, respectively. The enlarged blood-buffering capacity after infusion of Bicarb eliminated metabolic acidosis during maximal exercise but that did not affect the cerebral lactate uptake and, therefore, the decrease in the cerebral metabolic ratio. PMID:21098003

Volianitis, S; Rasmussen, P; Seifert, T; Nielsen, H B; Secher, N H

2011-01-01

415

A compact adaptive optics system with 3mm narrow-interval deformable mirror  

NASA Astrophysics Data System (ADS)

A 3mm narrow interval deformable mirror (DM) with tip-tilt stage has been developed for astronomical instruments. Benefiting from its compact design, the adaptive optics system can be built with simple structure and smaller optical elements. First, a 37-elements prototype mirror has been developed for our 1.8-meter telescope, which interval space is 3mm, maximum tilt is +/-10', and maximum deformation is +/-2?m. Based on this mirror, a simple adaptive optics system has been set up and its performance was tested in the laboratory especially the closed-loop correction ability. This adaptive optics subsystem is scheduled to be mounted at one folded Cassegrain focus of the 1.8-meter telescope this year, and comparison test for star compensation observation using this compact system and conventional adaptive optics system will also be carried out at the same time.

Li, Min; Xue, Lixia; Xian, Hao; Rao, Xuejun; Wei, Kai; Zhang, Xiaojun; Chen, Shanqiu; Zhang, Ang; Chen, Donghong; Rao, ChangHui; Zhang, Yudong

2014-08-01

416

Survival and photoreactivability of ultraviolet-irradiated cultured fish cells (CAF-MM1)  

SciTech Connect

The sensitivity to ultraviolet light (uv) and photoreactivating ability of cultured fish clone cells (CAF-MM1) were investigated. Dose-survival relationship curves were obtained using the colony-forming technique at various postirradiation temperatures (33, 26, and 20/sup 0/C). At 26/sup 0/C the values of D/sub 0/, D/sub q/, and the extrapolation number (n) were 1.74 J/m/sup 2/, 2.62 J/m/sup 2/, and 4.5, respectively; no marked differences in these values were found among different temperatures. Visible light illumination after uv irradiation produced a marked increase in survival. No photoreactivation effects were observed beyond about 30 h. Caffeine increased uv sensitivity of the CAF-MM1 cells, and from the results it is suggested that the cells have some caffeine-sensitive dark repair mechanisms.

Mano, Y. (Univ. of Tokyo, Hongo); Mitani, H.; Etoh, H.; Egami, N.

1980-12-01

417

A 3mm band SIS receiver for the Sardinia Radio Telescope  

NASA Astrophysics Data System (ADS)

We present the optical and mechanical design of a 3mm band SIS receiver for the Gregorian focus of the Sardinia Radio Telescope (SRT). The receiver, was designed and built at IRAM and deployed on the IRAM for the Plateau de Bure Interferometer antennas until 2006. Following its decommissioning the receiver was purchased by the INAFAstronomical Observatory of Cagliari with the aim to adapt its optics for test of the performance of the new 64-m diameter Sardinia Radio Telescope (SRT) in the 3 mm band (84 - 116 GHz). The instrument will be installed in the rotating turret inside of the Gregorian focal room of SRT. The dimensions of the focal room, the horn position in the lower side of the cryostat and the vessel for the liquid helium impose very hard constraints to the optical and mechanical mounting structure of the receiver inside the cabin. We present the receiver configuration and how we plan to install it on SRT.

Ladu, A.; Pisanu, T.; Navarrini, A.; Marongiu, P.; Valente, G.

2014-07-01

418

High-Resolution ?=1 mm CARMA Observations of Large Molecules in Orion-KL  

NASA Astrophysics Data System (ADS)

We present high-resolution Combined Array for Research in Millimeter-Wave Astronomy (CARMA) ?=1 mm observations of several molecular species toward Orion-KL. These are the highest spatial and spectral resolution 1 mm observations of these molecules to date. Our observations show that ethyl cyanide [C2H5CN] and vinyl cyanide [C2H3CN] originate from multiple cores near the Orion hot core and IRc7. In addition we show that dimethyl ether [(CH3)2O] and methyl formate [HCOOCH3] originate from IRc5 and IRc6 and that acetone [(CH3)2CO] originates only from areas where both N-bearing and O-bearing species are present.

Friedel, D. N.; Snyder, L. E.

2008-01-01

419

Estimating the shooting distance of a 9-mm Parabellum bullet via ballistic experiment.  

PubMed

We demonstrate here how the shooting distance of a 9-mm Parabellum FMJ bullet (115gr) has been estimated via shooting experiments. Such a bullet was found by investigators near a concrete wall, fairly distorted at its tip. The bullet carries no evidence of multiple impact and no evidence of ballistic impact on the wall has been reported. We estimated the impact velocity by comparing the questioned bullet with a set of comparison bullets hitting a wall (rigid target) with different velocities. The shooting distance was recovered from the impact velocity by studying the typical behavior of a manufactured 9 mm bullet weighting 115g (7.45g), shot in pistol or a sub-machine gun. The results demonstrated that the questioned bullet was a lost bullet. The shooting distance also helped the investigators, narrowing the range of the estimated positions of the shooter. PMID:19733457

Bresson, F; Franck, O

2009-11-20

420

Calibration of a 300-mm-aperture phase-shifting Fizeau interferometer.  

PubMed

A 300-mm-aperture digital phase-shifting Fizeau interferometer has been developed in-house for precision metrology of optical components fabricated by the optical workshop at Telecommunications and Industrial Physics, Commonwealth Scientific and Industrial Research Organization. We describe the procedures used in the calibration of the instrument. A reference data file representing the deviations from flatness of the reference surface is generated, measurement uncertainty estimated, and aberrations in the instrument assessed. Measurements on 250-mm-diameter uncoated optical surfaces have consistently shown short-term repeatability of 0.3-nm rms from measurement to measurement and allowed for absolute characterization of these surfaces to within a few nanometers. PMID:18354512

Oreb, B B; Farrant, D I; Walsh, C J; Forbes, G; Fairman, P S

2000-10-01

421

High Resolution $?$=1mm CARMA Observations of Large Molecules in Orion-KL  

E-print Network

We present high resolution, Combined Array for Research in Millimeter-Wave Astronomy (CARMA), $\\lambda$=1mm observations of several molecular species toward Orion-KL. These are the highest spatial and spectral resolution 1mm observations of these molecules to date. Our observations show that ethyl cyanide [C$_2$H$_5$CN] and vinyl cyanide [C$_2$H$_3$CN] originate from multiple cores near the Orion hot core and IRc7. Additionally we show that dimethyl ether [(CH$_3$)$_2$O] and methyl formate [HCOOCH$_3$] originate from IRc5 and IRc6 and that acetone [(CH$_3$)$_2$CO] originates only from areas where both N-bearing and O-bearing species are present.

D. N. Friedel; L. E. Snyder

2007-09-20

422

Deep x-ray lithography fabrication of mm Wave cavities at the Advanced Photon Source.  

SciTech Connect

Millimeter-wave (mmWave) accelerating cavity structures have been manufactured using the deep x-ray lithography (DXRL) technique. These cavity structures have potential applications as parts of linear accelerators, microwave undulatory, and mm-wave amplifiers. The microfabrication process includes manufacturing of precision x-ray masks, exposure of positive resist by x-rays through the mask, resist development, and electroforming of the final microstructure. Prototypes of a 32-cell, 108-GHz constant-impedance cavity and a 66-cell, 94-GHz constant-gradient cavity were fabricated at APS. Using an HP8510C 26-GHz vector network analyzer, rf measurements are being prepared with a frequency up- and down-converter before and after a test cavity structure. Preliminary design parameters for a 91-GHz multi-module klystron along with an overview of the DXRL technology are also discussed.

Song, J. J.

1998-09-11

423

Doppler echocardiographic comparison of small (19 mm) bileaflet and pericardial heart valve prostheses in aortic position.  

PubMed

The resting haemodynamics of five types of small (19 mm) aortic valve prosthesis (2 bileaflet, 3 pericardial) were evaluated with Doppler echocardiography in 43 patients. Two received St Jude Medical and six CarboMedics bileaflet valves and 35 were given bioprostheses--16 Ionescu-Shiley, four Mitroflow and 15 Labcor-Santiago. No significant differences in peak or mean transvalvular pressure drop or in effective valve area were found between the bileaflet and the pericardial valves or among the three types of bioprosthesis. All but one of the bileaflet prostheses showed a characteristic regurgitation pattern, with two lateral and one central jet, and 16 (46%) of the bioprostheses showed central regurgitation, but in no case were these jets haemodynamically significant. Thus the 19 mm bileaflet and the studied pericardial prostheses all have satisfactory resting haemodynamics, and all are suitable for implanting in small aortic roots. PMID:7644906

González-Juanatey, J R; Garcia Acuña, J M; Amaro, A; Castelo, V; Pedreira, M; Garcia Bengoechea, J; Gil, M

1995-01-01

424

A 2.5-mm diameter probe for photoacoustic and ultrasonic endoscopy  

PubMed Central

We have created a 2.5-mm outer diameter integrated photo-acoustic and ultrasonic mini-probe which can be inserted into a standard video endoscope’s instrument channel. A small-diameter focused ultrasonic transducer made of PMN-PT provides adequate signal sensitivity, and enables miniaturization of the probe. Additionally, this new endoscopic probe utilizes the same scanning mirror and micromotor-based built-in actuator described in our previous reports; however, the length of the rigid distal section of the new probe has been further reduced to ~35 mm. This paper describes the technical details of the mini-probe and presents experimental results that both quantify the imaging performance and demonstrate its in vivo imaging capability, which suggests that it could work as a mini-probe for certain clinical applications. PMID:23188360

Yang, Joon-Mo; Chen, Ruimin; Favazza, Christopher; Yao, Junjie; Li, Chiye; Hu, Zhilin; Zhou, Qifa; Shung, K. Kirk; Wang, Lihong V.

2012-01-01

425

THE MAGNETIC FIELD MORPHOLOGY OF THE CLASS 0 PROTOSTAR L1157-mm  

SciTech Connect

We present the first detection of polarization around the Class 0 low-mass protostar L1157-mm at two different wavelengths. We show polarimetric maps at large scales (10'' resolution at 350 {mu}m) from the SHARC-II Polarimeter and at smaller scales (1.''2-4.''5 at 1.3 mm) from the Combined Array for Research in Millimeter-wave Astronomy (CARMA). The observations are consistent with each other and show inferred magnetic field lines aligned with the outflow. The CARMA observations suggest a full hourglass magnetic field morphology centered about the core; this is only the second well-defined hourglass detected around a low-mass protostar to date. We apply two different methods to CARMA polarimetric observations to estimate the plane-of-sky magnetic field magnitude, finding values of 1.4 and 3.4 mG.

Stephens, Ian W.; Looney, Leslie W.; Kwon, Woojin; Crutcher, Richard M. [Department of Astronomy, University of Illinois, 1002 West Green Street, Urbana, IL 61801 (United States); Hull, Charles L. H.; Plambeck, Richard L. [Astronomy Department and Radio Astronomy Laboratory, 601 Campbell Hall, University of California, Berkeley, CA 94720 (United States); Chapman, Nicholas; Novak, Giles; Matthews, Tristan [Center for Interdisciplinary Exploration and Research in Astrophysics (CIERA) and Department of Physics and Astronomy, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208 (United States); Davidson, Jacqueline [School of Physics, University of Western Australia, 35 Stirling Hwy, Crawley, WA 6009 (Australia); Vaillancourt, John E. [SOFIA Science Center, Universities Space Research Association, NASA Ames Research Center, MS 232-11, Moffett Field, CA 94035-0001 (United States); Shinnaga, Hiroko, E-mail: stephen6@illinois.edu [Subaru Telescope, National Astronomical Observatory of Japan, 650 North A'ohoku Place, Hilo, HI 96720 (United States)

2013-05-20

426

AU FEBRUARY 2012 Open House: The AU Ph. D.  

E-print Network

AU FEBRUARY 2012 1 OPEN house Open House: The AU Ph. D. House Magazine By Alejandra Zaragoza Scherman Page 2 The AU PhD House Activity Group By Zsuzsanna Sukosd Page 3 The AU PhD House Activity Group By Gitte Haahr-Andersen Page 6 The AU PhD World: Talent Development By Kristian Thorn Page 7/8 The Ph

427

Transition probabilities for the L2,3 MM Auger spectrum of selenium  

Microsoft Academic Search

The theoretical L2,3 MM Auger transition rates for selenium are calculated using the radial integrals computed by McGuire. The calculation procedure assumes LS coupling for the initial hole state and either LS or intermediate coupling, as appropriate, for the final hole state. The theoretical rates are found to be in good agreement with the relative intensities observed in experimental spectra.

E. D. Roberts; P. Weightman; C. E. Johnson

1975-01-01

428

1. West portal of Tunnel 36, view to northeast, 135mm ...  

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

1. West portal of Tunnel 36, view to northeast, 135mm lens. Note the notched wingwalls that originally held timber posts of the original timber snowsheds, miles of which once enclosed and protected the railroad from the ravages of Sierra winters. Note also that these tunnels, built in the 1920s, have dispensed with any use of stone masonry, and instead have all-concrete portals. - Central Pacific Transcontinental Railroad, Tunnel No. 36, Milepost 176.92, Yuba Pass, Nevada County, CA

429

AzTEC 1.1 mm OBSERVATIONS OF THE MBM12 MOLECULAR CLOUD  

SciTech Connect

We present 1.1 mm observations of the dust continuum emission from the MBM12 high-latitude molecular cloud observed with the Astronomical Thermal Emission Camera (AzTEC) mounted on the James Clerk Maxwell Telescope on Mauna Kea, Hawaii. We surveyed 6.34 deg{sup 2} centered on MBM12, making this the largest area that has ever been surveyed in this region with submillimeter and millimeter telescopes. Eight secure individual sources were detected with a signal-to-noise ratio of over 4.4. These eight AzTEC sources can be considered to be real astronomical objects compared to the other candidates based on calculations of the false detection rate. The distribution of the detected 1.1 mm sources or compact 1.1 mm peaks is spatially anti-correlated with that of the 100 {mu}m emission and the {sup 12}CO emission. We detected the 1.1 mm dust continuum emitting sources associated with two classical T Tauri stars, LkH{alpha}262 and LkH{alpha}264. Observations of spectral energy distributions (SEDs) indicate that LkH{alpha}262 is likely to be Class II (pre-main-sequence star), but there are also indications that it could be a late Class I (protostar). A flared disk and a bipolar cavity in the models of Class I sources lead to more complicated SEDs. From the present AzTEC observations of the MBM12 region, it appears that other sources detected with AzTEC are likely to be extragalactic and located behind MBM12. Some of these have radio counterparts and their star formation rates are derived from a fit of the SEDs to the photometric evolution of galaxies in which the effects of a dusty interstellar medium have been included.

Kim, M. J.; Kim, S.; Youn, S.; Kang, Y.-W. [Department of Astronomy and Space Science, Sejong University, KwangJin-gu, KunJa-dong 98, Seoul 143-747 (Korea, Republic of); Yun, M. S.; Wilson, G. W. [Department of Astronomy, University of Massachusetts, 710 North Pleasant St., Amherst, MA 01003 (United States); Aretxaga, I.; Hughes, D. H.; Humphrey, A. [Instituto Nacional de Astrofisca, Optica y Electronica, Tonantzintla, Puebla (Mexico); Williams, J. P. [Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822 (United States); Austermann, J. E. [Department of Astrophysical and Planetary Sciences, University of Colorado, Boulder, Colorado 80309 (United States); Perera, T. A. [Department of Physics, Illinois Wesleyan University, Bloomington, IL 61701 (United States); Mauskopf, P. D. [School of Physics and Astronomy, Cardiff University, Cardiff CF24 3AA (United Kingdom); Magnani, L., E-mail: sek@sejong.ac.kr [Department of Physics and Astronomy, The University of Georgia, Athens, GA 30602-2451 (United States)

2012-02-10

430

4. East portal of Tunnel 18, view to southsoutheast, 210mm ...  

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

4. East portal of Tunnel 18, view to south-southeast, 210mm lens. Compare the condition of the concrete at this portal, located some 350 feet lower than the west portal and on the sheltered north side of the pass, with that of the west portal in photo 1. - Southern Pacific Railroad Natron Cutoff, Tunnel 3, Milepost 537.77, Odell Lake, Klamath County, OR

431

A Magnetic Dynamo Origin For The Sub-mm Excess In Sgr A*  

E-print Network

The sub-mm bump observed in the spectrum of Sgr A* appears to indicate the existence of a compact emitting component within several Schwarzschild radii, $r_S$, of the nucleus at the Galactic Center. This is interesting in view of the predicted circularized flow within $\\sim 5-10 r_S$, based on detailed multi-dimensional hydrodynamic simulations of Bondi-Hoyle accretion onto this unusual object. In this paper, we examine the physics of magnetic field generation by a Keplerian dynamo subject to the conditions pertaining to Sgr A*, and show that the sub-mm bump can be produced by thermal synchrotron emission in this inner region. This spectral feature may therefore be taken as indirect evidence for the existence of this circularization. In addition, the self-Comptonization of the sub-mm bump appears to produce an X-ray flux exceeding that due to bremsstrahlung from this region, which may account for the X-ray counterpart to Sgr A* discovered recently by {\\it Chandra}. However, the required accretion rate in the Keplerian flow is orders of magnitude smaller than that predicted by the Bondi-Hoyle simulations. We speculate that rapid evaporation, in the form of a wind, may ensue from the heating associated with turbulent mixing of gas elements with large eccentricity as they settle down into a more or less circular (i.e., low eccentricity) trajectory. The spectrum of Sgr A* longward of $\\sim 1-2$ mm may be generated outside of the Keplerian flow, where the gas is making a transition from a quasi-spherical infall into a circularized pattern.

Fulvio Melia; Siming Liu; Robert Coker

2001-05-27

432

Exploring Brown Dwarf Disks: A 1.3 mm Survey in Taurus  

Microsoft Academic Search

We have carried out sensitive 1.3 mm observations of 20 young brown dwarfs in the Taurus star-forming region, representing the largest sample of young substellar objects targeted in a deep millimeter-continuum survey to date. Under standard assumptions, the masses of brown dwarf disks range from <~0.4 to several Jupiter masses. Their relative disk masses are comparable to those derived for

Alexander Scholz; Ray Jayawardhana; Kenneth Wood

2006-01-01

433

Wireless data center networking with steered-beam mmWave links  

Microsoft Academic Search

This paper presents a new type of wireless network- ing applications in data centers using steered-beam mmWave links. By taking advantage of clean LOS channels on top of server racks, robust wireless packet-switching network can be built. The transmission latency can be reduced by flexibly bridging adjacent rows of racks wirelessly without using long cables and multiple switches. Eliminating cables

Yasunao Katayama; Kohji Takano; Yasuteru Kohda; Nobuyuki Ohba; Daiju Nakano

2011-01-01

434

Improving the Q2MM method for transition state force field modeling.  

PubMed

The Quantum-to-molecular mechanics method (Q2MM) for converting quantum mechanical transition states (TSs) to molecular mechanical minima has been modified to allow a fit to the "natural" reaction mode eigenvalue. The resulting force field gives an improved representation of the energy curvature at the TS, but can potentially give false responses to steric interactions. Ways to address this problem while staying close to the "natural" TS force field are discussed. © 2014 Wiley Periodicals, Inc. PMID:25430788

Limé, Elaine; Norrby, Per-Ola

2015-02-01

435

MM-DSM: Multi-threaded Multi-home Distributed Shared Memory Systems  

Microsoft Academic Search

Most traditional Distributed Shared Memory (DSM) systems support data sharing in multi-process applications. This paper proposed a Multi-threaded Multi-home DSM system (MM-DSM) to support both data sharing and computation synchronization in multi-threaded applications whose threads are grouped into bundles and distributed across multiple computers for parallel execution. Globally shared data are rearranged and assigned to different thread bundles based on

Chonglei Mei; Hai Jiang; Jeff Jenness

2009-01-01

436

Numerical modelling of 8mm TM01-TE11 mode converter  

NASA Astrophysics Data System (ADS)

A numerical study of TM01-TE11 circular waveguide mode converter, with its optimized size and structure, is presented in this paper. Many factors such as spurious modes, backward wave, perturbation functions of waveguide axis or radius, phase-rematching techniques and ohmic losses are taken into account for the influence to mode converter's efficiency and bandwidth. And the dimensions of an optimized model (f0=35GHz. with input and output radius a0=13.6mm) are given.

Yang, Shiwen; Li, Hongfu

1995-11-01

437

STS-36 Commander Creighton uses 70mm HASSELBLAD camera on flight deck  

NASA Technical Reports Server (NTRS)

STS-36 Commander John O. Creighton points 70mm HASSELBLAD camera out overhead window W7 on the aft flight deck of Atlantis, Orbiter Vehicle (OV) 104. The onorbit station panels and aft viewing window W9 appear above Creighton's head while he records the Earth imagery with the camera. Creighton and four other astronauts spent four days, 10 hours and 19 minutes aboard OV-104 for the Department of Defense (DOD) devoted mission.

1990-01-01

438

30-W\\/mm GaN HEMTs by field plate optimization  

Microsoft Academic Search

GaN high-electron-mobility-transistors (HEMTs) on SiC were fabricated with field plates of various dimensions for optimum performance. Great enhancement in radio frequency (RF) current-voltage swings was achieved with acceptable compromise in gain, through both reduction in the trapping effect and increase in breakdown voltages. When biased at 120 V, a continuous wave output power density of 32.2 W\\/mm and power-added efficiency

Y.-F. Wu; A. Saxler; M. Moore; R. P. Smith; S. Sheppard; P. M. Chavarkar; T. Wisleder; U. K. Mishra; P. Parikh

2004-01-01

439

10-W\\/mm AlGaN-GaN HFET with a field modulating plate  

Microsoft Academic Search

AlGaN-GaN heterojunction field-effect transistors (HFETs) with a field modulating plate (FP) were fabricated on an SiC substrate. The gate-drain breakdown voltage (BVgd) was significantly improved by employing an FP electrode, and the highest BVgd of 160 V was obtained with an FP length (LFP) of 1 ?m. The maximum drain current achieved was 750 mA\\/mm, together with negligibly small current

Y. Ando; Y. Okamoto; H. Miyamoto; T. Nakayama; T. Inoue; M. Kuzuhara

2003-01-01

440

0 200 400 600 800 1000 KD (nM)Apparent KD (mM)  

E-print Network

400 500 0 5000 10000 15000 20000 25000 30000 35000 40000 45000 1 Bulyk, M.L., Huang, X., Choo, Y0 5000 10000 15000 20000 25000 30000 35000 40000 45000 0 200 400 600 800 1000 KD (nM)Apparent KD (mM. & Church, G.M. Exploring the DNA-binding specificities of zinc fingers with DNA microarrays. Proc Natl Acad

Bulyk, Martha L.

441

Side-cooled 1200 mm silicon x-ray mirrors with pneumatic benders  

NASA Astrophysics Data System (ADS)

This paper reports the successful design, fabrication, and testing of several side-cooled silicon and SiC (graphite) synchrotron mirrors (flat, spherical, and cylindrical) with a length of up to 1200 mm. The mirrors are equipped with support structures which allow the mirrors to be bent meridionally to cylinders with radii from infinity to 5000 m. Detailed metrology results are presented for the mirrors and the bending system. All mirrors will be installed at ESRF beamlines 8, 15, and 19.

Pauschinger, D.; Becker, K.; Ludewig, R.

1995-02-01

442

Design and performance of Sandia's contactless coilgun for 50 mm projectiles  

Microsoft Academic Search

A multistage, contactless coilgun is being designed to demonstrate the applicability of this technology to accelerate nominal 50-mm-diameter projectiles to velocities of 3 km\\/s. Forty stages of this design (Phase 1 coilgun) will provide a testbed for coil designs and system components while accelerating 200 to 400 g projectiles to 1 km\\/s. The Phase 1 gun was successfully qualified by

Ronald J. Kaye; Eugene C. Cnare; M. Cowan; Billy W. Duggin; Ronald J. Lipinski; Barry M. Marder; Gary M. Douglas; Kenneth J. Shimp

1993-01-01

443

Tiffany Niemoller Eady, Ph.D. Major Professor: Nicolas G. Bazan, M.D., Ph.D.  

E-print Network

May, 2011 Tiffany Niemoller Eady, Ph.D. Major Professor: Nicolas G. Bazan, M.D., Ph.D. Dissertation: Docosahexaenoic Acid, Neurolipidomics, and the Ischemic Penumbra of Stroke Hongbo He, Ph.D. Major Professor: Jeffrey D. Erickson, Ph.D. Dissertation: Functional Distinctions between Vesicular Glutamate Transporter

444

Transcription of denitrification genes and kinetics of NO, N2O and N2 by soil bacteria as affected by pH  

NASA Astrophysics Data System (ADS)

Nitrous oxide (N2O), which is to a large part derived from denitrification in soil, is a major greenhouse gas and was also recently shown to be the single most important ozone-depleting substance. Previous studies demonstrate that the N2O/N2 product ratio of denitrification is strongly dependent on pH, increasing with decreasing soil pH. The mechanisms involved are, however, poorly understood. We here present an investigation of soils from a long-term liming experiment. Since it is difficult to control which pH is actually experienced by bacterial cells in intact soils, we extracted cells on a Nycodenz gradient and exposed them to different pH levels. Bacteria extracted from soils of 3 different pHs (4.0, 6.1 and 8.0) were incubated in minimal medium supplemented with nitrate (2mM) and glutamic acid (5 mM), buffered at three pH levels (5.7, 6.1 and 7.6). Both the pH of the medium and original soil pH showed profound effect on the denitrification activity in terms of gas emission kinetics. N2O reductase (N2OR) activity was only present when cells from the high pH soils (pH 6.1 and 8.0) were exposed to high pH medium (pH 7.6). Functional genes (nirS, nirK and nosZ) and their transcripts were quantified in the extracts from pH6.1-soil. A 10-25 fold higher expression of nosZ vs nirS was found when incubated at pH 7.6 compared to pH 6.1 and 5.7. The low but significant transcription of nosZ at pH 6.1 and 5.7 did not result in detectable N2O reduction however. Cells that had been allowed to assemble their proteome while growing in pH7 medium showed N2OR activity which was practically unaffected by pH within the range 5-7. On the contrary, no N2OR activity was detected if the proteome had been formed at pH 6. The cells extracted from acid soils (pH 5.8 and 6.1) showed very low nosZ transcritption and no N2OR activity if exposed to pH 7 during the transition from oxic to anoxic conditions, suggesting an adaptation to low pH in the sense that they do not transcribe the gene for N2OR. This could be an advantage, since the chances of producing a functional N2OR enzymes are meager at that pH. The results demonstrated that low pH has profound effect on the relative activity of the N2OR in soil bacterial communities, by interference both at transcriptional and post transcriptional level, but not by a direct effect on the successfully assembled enzyme. In other words, the frequently observed high N2O/N2 product ratio of denitrification in acid soils is not due to a direct effect on the activity of the N2O reductase enzyme.

Liu, B.; Bakken, L. R.; Frostegard, A.

2010-12-01

445

Dynamic QM/MM: a hybrid approach to simulating gas-liquid interactions.  

PubMed

In this chapter we describe molecular dynamics simulation methods in which the system being studied is divided into a region where quantum mechanics (QM) is used to determine forces for doing Born-Oppenheimer direct dynamics calculations (i.e., doing electronic structure calculations on the fly to determine energies and forces) and another region where empirical potentials that are commonly used in molecular mechanics (MM) calculations are used to determine forces. The two regions are linked through an embedding process that may or may not involve the possibility that atoms can be passed back and forth between regions at each time step. The idea with this dynamic QM/MM methodology is that one uses QM calculations to define the potential surface in portions of the system where reaction occurs, and MM to determine forces in what is typically a much larger region where no reaction occurs. This approach thereby enables the description of chemical reactions in the QM region, which is a technology that can be used in many different applications. We illustrate its use by describing work that we have done with gas-liquid reactions in which a reactive atom (such as an oxygen or fluorine atom) reacts with the surface of a liquid and the products can either remain in the liquid or emerge into the gas phase. Applications to hydrocarbon and ionic liquids are described, including the characterization of reaction mechanisms at hyperthermal energies, and the determination of product branching and product energy distributions. PMID:21506003

Yockel, Scott; Schatz, George C

2012-01-01

446

3-mm double-heterojunction microwave power HEMT fabricated by selective RIE  

NASA Astrophysics Data System (ADS)

Current-voltage and initial RF measurements are presented on a double-heterojunction HEMT (high-electron-mobility transistor) structure designed for power MMIC applications. The device structure is grown by molecular-beam epitaxy and uses a spatially variant superlattice to improve the performance of the inverted AlGaAs/GaAs interface. Gate recessing is achieved using a hybrid wet-chemical-selective dry etching process. For selective dry etching, reactive ion etching with a greater than 600:1 selectivity for GaAs over AlGaAs is used to control the recess depth. The room temperature dc characteristics for a 3-mm power FET (0.7-micron gate) display an Idss of 370 mA/mm, a peak transconductance of 180 mS/mm, and a maximum gate-to-drain breakdown of 22 V. Large-signal microwave measurements at 5.5 GHz yielded a saturated output power of 1.3 W (31.2 dBm), 8.3-dB large-signal gain, and a peak power-added efficiency of 55 percent.

van Hove, J. M.; Schuelke, Robert J.; Thomes, G. P.; Jorgenson, J. D.; Chang, E. Y.

1988-10-01

447

Monitoring observations of selected SiO maser sources at 7 mm wavelength - 1977-1979  

NASA Technical Reports Server (NTRS)

High-spectral-resolution SiO maser observations at 7 mm wavelength were made for 13 circumstellar objects and Ori A over a 34 month interval from January 1977 to November 1979. These data precede and adjoin the SiO monitoring data taken at 3 and 7 mm wavelengths by Lane (1982) and at 3 mm wavelengths by Nyman and Olofsson (1985) and thus provide an important link in the record of the temporal behavior of SiO masers over a period of several years. The time-averaged center of the weak SiO maser emission pedestal gives the stellar radial velocity. This reinforces the idea that the SiO maser emission pedestal is representative of the true structure of a stellar SiO maser, while the more visible and stronger, narrow SiO emission spikes represent chance coherences along the velocity range of the pedestal. Similarities between the SiO maser velocity patterns of VY CMa and Ori A may suggest similarities in their evolutionary stages.

Snyder, L. E.; Jewell, P. R.; Dinger, A. S.; Dickinson, D. F.; Buhl, D.

1986-01-01

448

An extensible interface for QM/MM molecular dynamics simulations with AMBER.  

PubMed

We present an extensible interface between the AMBER molecular dynamics (MD) software package and electronic structure software packages for quantum mechanical (QM) and mixed QM and classical molecular mechanical (MM) MD simulations within both mechanical and electronic embedding schemes. With this interface, ab initio wave function theory and density functional theory methods, as available in the supported electronic structure software packages, become available for QM/MM MD simulations with AMBER. The interface has been written in a modular fashion that allows straight forward extensions to support additional QM software packages and can easily be ported to other MD software. Data exchange between the MD and QM software is implemented by means of files and system calls or the message passing interface standard. Based on extensive tests, default settings for the supported QM packages are provided such that energy is conserved for typical QM/MM MD simulations in the microcanonical ensemble. Results for the free energy of binding of calcium ions to aspartate in aqueous solution comparing semiempirical and density functional Hamiltonians are shown to demonstrate features of this interface. PMID:24122798

Götz, Andreas W; Clark, Matthew A; Walker, Ross C

2014-01-15

449

QuanPol: a full spectrum and seamless QM/MM program.  

PubMed

The quantum chemistry polarizable force field program (QuanPol) is implemented to perform combined quantum mechanical and molecular mechanical (QM/MM) calculations with induced dipole polarizable force fields and induced surface charge continuum solvation models. The QM methods include Hartree-Fock method, density functional theory method (DFT), generalized valence bond theory method, multiconfiguration self-consistent field method, Møller-Plesset perturbation theory method, and time-dependent DFT method. The induced dipoles of the MM atoms and the induced surface charges of the continuum solvation model are self-consistently and variationally determined together with the QM wavefunction. The MM force field methods can be user specified, or a standard force field such as MMFF94, Chemistry at Harvard Molecular Mechanics (CHARMM), Assisted Model Building with Energy Refinement (AMBER), and Optimized Potentials for Liquid Simulations-All Atom (OPLS-AA). Analytic gradients for all of these methods are implemented so geometry optimization and molecular dynamics (MD) simulation can be performed. MD free energy perturbation and umbrella sampling methods are also implemented. PMID:24122765

Thellamurege, Nandun M; Si, Dejun; Cui, Fengchao; Zhu, Hongbo; Lai, Rui; Li, Hui

2013-12-15

450

QM/MM Analysis of Cellulase Active Sites and Actions of the Enzymes on Substrates  

SciTech Connect

Biodegradation of cellulosic biomass requires the actions of three types of secreted enzymes; endoglucanase (EC 3.2.1.4), cellobiohydrolase or exoglucanase (EC 3.2.1.91), and -glucosidase (EC 4.2.1.21). These enzymes act synergistically to hydrolyse the -1,4 bonds of cellulose and converts it into simple sugar. Hydrolysis of the glycosidic bond can occur either by net retention or by inversion of anomeric configuration at the anomeric center. QM/MM simulations are useful tools to study the energetics of the reactions and analyze the active-site structures at different states of the catalysis, including the formation of unstable transition states. Here, a brief description of previous work on glycoside hydrolases is first given. The results of the QM/MM potential energy and free energy simulations corresponding to glycosylation and deglycosylation processes are then provided for two retaining endoglucanases, Cel12A and Cel5A. The active-site structural features are analyzed based on the QM/MM results. The role of different residues and hydrogen bonding interactions during the catalysis and the importance of the sugar ring distortion are discussed for these two enzymes.

Saharay, Moumita [ORNL; Guo, Hao-Bo [ORNL; Smith, Jeremy C [ORNL; Guo, Hong [ORNL

2010-01-01

451

Highly efficient InGaN MQW LEDs grown on 200 mm Si substrates  

NASA Astrophysics Data System (ADS)

We demonstrate InGaN MQW LEDs on Si substrates have both high performance and low cost structure. The blue LED structures were grown by metal-organic chemical vapor deposition via unique buffer layers on 200 mm-diameter Si (111) substrates. The epitaxial wafers had slightly ex-situ convex bow without micro-cracks. Median and standard deviation of dominant wavelength by photoluminescence measurement were 448.9 nm and 2.0 nm within 4 mm edge exclusion, respectively. XRC FWHMs of GaN (0002) and GaN (10-12) were 341 arcsec and 388 arcsec, respectively, corresponding to be estimated to edge dislocation density of 2.0 × 109 /cm2. The blue LED structures were fabricated by legacy 8-inch (200-mm) Si device equipment without remodeling, because no particular thicker Si wafer was needed for our LED epitaxial growth. Encapsulated blue lamps were fabricated after dicing with 45 × 45 mil2. Median light output power of 641 mW was obtained under injection current of 350 mA at 25 deg-C. The operating voltage was 2.9 V. It corresponds to wall plug efficiency, WPE of 63 %. Stable operation more than 6,000 hours under 450 mA at 85 deg-C was confirmed. These results suggest the InGaN MQW LEDs on the large-scale Si wafers are promising for the near future solid-state lighting.

Onomura, Masaaki

2014-03-01

452

An extensible interface for QM/MM molecular dynamics simulations with AMBER  

PubMed Central

We present an extensible interface between the AMBER molecular dynamics (MD) software package and electronic structure software packages for quantum mechanical (QM) and mixed QM and classical molecular mechanical (MM) MD simulations within both mechanical and electronic embedding schemes. With this interface, ab initio wave function theory and density functional theory methods, as available in the supported electronic structure software packages, become available for QM/MM MD simulations with AMBER. The interface has been written in a modular fashion that allows straight forward extensions to support additional QM software packages and can easily be ported to other MD software. Data exchange between the MD and QM software is implemented by means of files and system calls or the message passing interface standard. Based on extensive tests, default settings for the supported QM packages are provided such that energy is conserved for typical QM/MM MD simulations in the microcanonical ensemble. Results for the free energy of binding of calcium ions to aspartate in aqueous solution comparing semiempirical and density functional Hamiltonians are shown to demonstrate features of this interface. PMID:24122798

Götz, Andreas W.; Clark, Matthew A.; Walker, Ross C.

2014-01-01

453

A system-level simulator for indoor mmW SAR imaging and its applications.  

PubMed

Recently, the research interest in indoor active millimeter wave (mmW) imaging by applying the synthetic aperture radar (SAR) technique is increasing. However, there is a lack of proper computer-aided design (CAD) tools at the system level, and almost all the R&D activities rely on experiments solely. The high cost of such a system stops many researchers from investigating such a fascinating research topic. Moreover, the experiment-oriented studies may blind the researchers to some details during the imaging process, since in most cases they are only interested in the readout from the receivers and do not know how the waves perform in reality. To bridge such a gap, we propose a modeling approach at mmW frequencies, which is able to simulate the physical process during SAR imaging. We are not going to discuss about advanced image reconstruction algorithms, since they have already been investigated intensively for decades. To distinguish from previous work, for the first time, we model the data acquisition process in a SAR imaging system successfully at mmW frequencies. We show how to perform some system-level studies based on such a simulator via a common PC, including the influence of reflectivity contrast between object and background, sampling step, and antenna's directivity on image quality. The simulator can serve system design purposes and it can be easily extended to THz frequencies. PMID:23188346

Qi, Feng; Ocket, Ilja; Schreurs, Dominique; Nauwelaers, Bart

2012-10-01

454

Fast polarization changes in mm microwave emission of weak multistructured solar bursts  

NASA Technical Reports Server (NTRS)

Circular polarization of weak multistructured solar bursts was measured at mm microwaves with unprecedented sensitivity (0.03 sfu rms) and high time resolution (1ms). It was shown that sudden changes occur in the degree of polarization with time scales of 0.04 to 0.3 s. In most cases the degree of polarization attained maximum values before the maximum flux in both mm microwaves and hard X-rays with time scales of 0.04 to 1.0 s. The timing accuracy in determining the degree of polarization was 40 ms. Physical phenomena are discussed invoking one or a combination of various possible causes for the observed effects. The bursts at mm microwaves were weak compared to the contribution of the preexisting active regions, and therefore the changes in magnetoionic propagation conditions for emerging radiation plays an important role in the observed effects. Composite effects due to more than one polarizing mechanism or more than one polarized spots within the antenna beam are discussed.

Kaufmann, P.; Strauss, F. M.; Costa, J. E. R.; Dennis, B. R.

1982-01-01

455

PhD Journey: Some Shared Experiences  

Microsoft Academic Search

Academic interest in the PhD journey predominately concerns the technical aspects of the doctorate. It tends to concentrate on a number of pragmatic areas, such as, deciding on and narrowing down the topic area; choosing a supervisor; the pitfalls associated with supervision; alternative methodological approaches to research; and writing up the thesis (Dunleavy, 2003, Graves and Varma, 1997, Pearson and

Lucie Crawford

456

The Ph.D. Value Proposition  

ERIC Educational Resources Information Center

Atlanta University launched its doctor of arts in humanities (DAH) programs almost 40 years ago, and, since the 1988 merger with Clark College, Clark Atlanta University has continued to award the degrees. This fall, for the first time, its students will be able to earn Ph.D.s in humanities instead. In DAH programs around the country, there's been…

Cooper, Kenneth J.

2012-01-01

457

Ph.D. Program in Machine Learning  

E-print Network

Page 1 Ph.D. Program in Machine Learning Student Handbook Revised 7/20/12 #12;Page 2 Table Machine Learning Journal Club...................................................................................................17 #12;Page 3 Introduction The field of machine learning is concerned with the question of how

458

Optoelectronic pH Meter: Further Details  

NASA Technical Reports Server (NTRS)

A collection of documents provides further detailed information about an optoelectronic instrument that measures the pH of an aqueous cell-culture medium to within 0.1 unit in the range from 6.5 to 7.5. The instrument at an earlier stage of development was reported in Optoelectronic Instrument Monitors pH in a Culture Medium (MSC-23107), NASA Tech Briefs, Vol. 28, No. 9 (September 2004), page 4a. To recapitulate: The instrument includes a quartz cuvette through which the medium flows as it is circulated through a bioreactor. The medium contains some phenol red, which is an organic pH-indicator dye. The cuvette sits between a light source and a photodetector. [The light source in the earlier version comprised red (625 nm) and green (558 nm) light-emitting diodes (LEDs); the light source in the present version comprises a single green- (560 nm)-or-red (623 nm) LED.] The red and green are repeatedly flashed in alternation. The responses of the photodiode to the green and red are processed electronically to obtain the ratio between the amounts of green and red light transmitted through the medium. The optical absorbance of the phenol red in the green light varies as a known function of pH. Hence, the pH of the medium can be calculated from the aforesaid ratio.

Jeevarajan, Antony S.; Anderson, Mejody M.; Macatangay, Ariel V.

2009-01-01

459

December 1996 quant-ph 9804023  

E-print Network

, 05.30.-d. KEY WORDS: decoherence; Dirac equation; entropy; Zitterbewegung. 1 #12;DecoherenceDecember 1996 quant-ph 9804023 DECOHERENCE IN THE DIRAC EQUATION David A. Meyer Project in Geometry the occurence of decoherence in the Dirac equation upon tracing over position. We conclude that the physics

Meyer, David A.

460

Barbara E Engelhardt, PhD Information  

E-print Network

, exams, homework assignments, and grading. Professional Experience 23andMe, Mountain View, California USA for calling SNPs. Google, Mountain View, California USA Summer Intern, Research Group May 2005 - August 2005 expression association studies. Education University of California, Berkeley, Berkeley, California USA Ph

Pritchard, Jonathan

461

PhET Simulation: Vector Addition  

NSDL National Science Digital Library

This applet allows user to learn how to add vectors. Users may drag vectors onto a graph, changing their length and angle, and calculate their sum. The magnitude, angle, and components of each vector can be displayed in several formats. Teaching ideas and activities are included. This is part of a larger collection developed by the Physics Education Technology project (PhET).

2008-07-13

462

Ph.D. PSYCHOLOGY Application Checklist  

E-print Network

Ph.D. PSYCHOLOGY Application Checklist IMPORTANT NOTES 1. Please submit all Application Materials.D. in Psychology must have both a Bachelors and Masters degree, at least one of which must be in Psychology (Maximum 10 pages). GRE Test Scores: Applicants who do not have a Master's degree in Psychology must submit

Northern British Columbia, University of

463

Curriculum Vitae Christopher Dehon, Ph.D.  

E-print Network

.P.H. Functioned as the sole therapist responsible for piloting a new treatment for PTSD in young children and their mothers following trauma. Treatment addressed both the classic symptoms of PTSD and parent training for externalizing problems that were comorbid with children's symptoms of PTSD. Analyzed the overall effectiveness

Li, X. Rong

464

Graduate Student Guidelines Ph.D. Program  

E-print Network

..........................................................................................................................................3 Minimum Number of Credits for Ph.D. Degree CALENDAR: Fall semester 2012: First day of classes August 20 Last day of classes December 7 Close of Finals week December 14 Spring semester 2013: First day of classes January 22 Last day of classes May 10 Close

465

Rosemarie Hunziker, PhD Program Director  

E-print Network

9/2/2014 1 Rosemarie Hunziker, PhD Program Director Tissue Engineering/Regenerative Medicine Development Just Send It Now it's our turn: The Review Process - Find the Best Review Committee - Understand the Assessment - Respond to the Evaluation TODAY'S AGENDA: THE DEEP DIVE INTO NIH GRANTS ... improving health

Boyer, Elizabeth W.

466

Scholarly Integrity Julie Simpson, Ph.D.  

E-print Network

information ~ http://unh.edu/research/rcr-training- unh #12;GRAD 930: Ethics in Research & Scholarship Data Use of Human Subjects in Research Care & Use of Vertebrate Animals Use of Controlled SubstancesScholarly Integrity at UNH Julie Simpson, Ph.D. Director, Research Integrity Services #12;Scholarly

New Hampshire, University of

467

Scholarly Integrity Julie Simpson, Ph.D.  

E-print Network

- based modules before attendance at in- person sessions #12;GRAD 930: Ethics in Research & Scholarship & Management of Research Data Use of Human Subjects in Research Care & Use of Vertebrate Animals UseScholarly Integrity at UNH Julie Simpson, Ph.D. Director, Research Integrity Services #12;Scholarly

New Hampshire, University of

468

Valerie Paton, Ph.D. Interim Dean  

E-print Network

at Highland Lakes/ Marble Falls Amy Fernandez Administrative Business Assistant FTE 1.0 Jerrie Dooley Advisor Tech University FY13 Transition Julie Martenson. Ph.D. Director TTU at Fredericksburg and TTU at Marble Falls/ Highland Lakes FTE 1.0 Robert Stubblefield Director TTU Center at Junction FTE 1.0 Donna Hamilton

Rock, Chris

469

Teaching Physics Using PhET Simulations  

ERIC Educational Resources Information Center

PhET Interactive Simulations (sims) are now being widely used in teaching physics and chemistry. Sims can be used in many different educational settings, including lecture, individual or small group inquiry activities, homework, and lab. Here we will highlight a few ways to use them in teaching, based on our research and experiences using them in…

Wieman, C. E.; Adams, W. K.; Loeblein, P.; Perkins, K. K.

2010-01-01

470

Instrument development and field application of the in situ pH Calibrator at the Ocean Observatory  

NASA Astrophysics Data System (ADS)

A novel, self-calibrating instrument for in-situ measurement of pH in deep sea environments up to 4000 m has recently been developed. The device utilizes a compact fluid delivery system to perform measurement and two-point calibration of the solid state pH sensor array (Ir|IrOx| Ag|AgCl), which is sealed in a flow cell to enhance response time. The fluid delivery system is composed of a metering pump and valves, which periodically deliver seawater samples into the flow cell to perform measurements. Similarly, pH buffer solutions can be delivered into the flow cell to calibrate the electrodes under operational conditions. Sensor signals are acquired and processed by a high resolution (0.25 mV) datalogger circuit with a size of 114 mm×31 mm×25 mm. Eight input channels are available: two high impedance sensor input channels, two low impedance sensor input channel, two thermocouple input channels and two thermistor input channels. These eight channels provide adequate measurement flexibility to enhance applications in deep sea environments. The two high impedance channels of the datalogger are especially designed with the input impedance of 1016 ? for YSZ (yittria-stabilized zirconia) ceramic electrodes characterized by the extremely low input bias current and high resistance. Field tests have been performed in 2008 by ROV at the depth up to 3200 m. Using the continuous power supply and TCP/IP network capability of the Monterey Accelerated Research System (MARS) ocean observatory, the so-called "pH Calibrator" has the capability of long term operation up to six months. In the observatory mode, the electronics are configured with DC-DC power converter modules and Ethernet to serial module to gain access to the science port of seafloor junction box. The pH Calibrator will be deployed at the ocean observatory in October and the in situ data will be on line on the internet. The pH Calibrator presents real time pH data at high pressures and variable temperatures, while the in situ calibration capability enhances the accuracy of electrochemical measurements of seawater pH, fulfilling the need for long term objectives for marine studies.

Tan, C.; Ding, K.; Seyfried, W. E.

2012-12-01

471

Effect of electrolyte pH on CIEF with narrow pH range ampholytes.  

PubMed

CIEF of components following sequential injection of ampholytes and the sample zone offers unique advantages for analysis. The most important one of these is the efficient separation of amphoteric compounds having pIs outside the pH range of the ampholytes applied, but the resolution of the components can be increased by an adequate setup in the injection protocol. In this study, the effect of the pH of the anolyte and catholyte on the selectivity and speed of the isoelectric focusing was investigated. Changes in the pH values significantly influenced the resolution and the length of the pH gradient, while changes in the charge state of components were also observed. Three ampholyte solutions (from different suppliers) covering only two pH units were used for the analyses of substituted nitrophenol dyes in uncoated capillary. With appropriate setup, the components, with pIs not covered by the ampholyte pH range, migrated in charged state outside the pH gradient. This phenomenon is preferable for coupling isoelectric focusing to MS detection, by evading the undesirable ion suppression effect of ampholytes. PMID:23086725

Páger, Csilla; Vargová, Andrea; Takácsi-Nagy, Anna; Dörnyei, Ágnes; Kilár, Ferenc

2012-11-01

472

In Situ Fluorescence Measurement of Tear Film [Na+], [K+], [Cl?], and pH in Mice Shows Marked Hypertonicity in Aquaporin-5 Deficiency  

PubMed Central

Purpose Tear film composition depends on water and ion transport across ocular surface epithelia and on fluid secretion by lacrimal glands. The purpose of this study was to establish in situ fluorescence methods to measure tear film ionic concentrations and pH in mice and to determine whether tear film composition is sensitive to deficiency of the major ocular surface aquaporin water channels. Methods Tear film ionic concentrations and pH were measured in anesthetized mice by ratio imaging fluorescence microscopy after topical application of ion/pH-sensing, dual-wavelength fluorescent indicators. [Na+], [K+], and [Cl?] were measured with membrane-impermeant indicators developed by our laboratory, and pH was measured with bis(carboxyethyl)-carboxyfluorescein fluorescence-conjugated dextran. Measurements were performed on wild-type mice and on knockout mice lacking aquaporins AQP1, AQP3, and AQP5. Results In wild-type mice, tear film [Na+] was 139 ± 8 mM, [K+] was 48 ± 1 mM, [Cl?] was 127 ± 4 mM, and pH was 7.59 ± 0.2 (SE; n = 5–8). pH did not differ significantly in the AQP knockout mice. [Na+] was increased by approximately twofold in AQP5 null mice (230 ± 20 mM) and was greatly reduced after exposure of the ocular surface to a humidified atmosphere. [K+] was mildly reduced in AQP1 null mice. Conclusions These results establish an in situ optical methodology to measure tear film [Na+], [K+], [Cl?], and pH in living mice, without the need for fluid sampling. Tear film hypertonicity in AQP5 deficiency is likely caused by reduced transcorneal water secretion in response to evaporative water loss. PMID:19136711

Ruiz-Ederra, Javier; Levin, Marc H.; Verkman, A. S.

2009-01-01

473

Advances in quantum and molecular mechanical (QM/MM) simulations for organic and enzymatic reactions.  

PubMed

Application of combined quantum and molecular mechanical (QM/MM) methods focuses on predicting activation barriers and the structures of stationary points for organic and enzymatic reactions. Characterization of the factors that stabilize transition structures in solution and in enzyme active sites provides a basis for design and optimization of catalysts. Continued technological advances allowed for expansion from prototypical cases to mechanistic studies featuring detailed enzyme and condensed-phase environments with full integration of the QM calculations and configurational sampling. This required improved algorithms featuring fast QM methods, advances in computing changes in free energies including free-energy perturbation (FEP) calculations, and enhanced configurational sampling. In particular, the present Account highlights development of the PDDG/PM3 semi-empirical QM method, computation of multi-dimensional potentials of mean force (PMF), incorporation of on-the-fly QM in Monte Carlo (MC) simulations, and a polynomial quadrature method for efficient modeling of proton-transfer reactions. The utility of this QM/MM/MC/FEP methodology is illustrated for a variety of organic reactions including substitution, decarboxylation, elimination, and pericyclic reactions. A comparison to experimental kinetic results on medium effects has verified the accuracy of the QM/MM approach in the full range of solvents from hydrocarbons to water to ionic liquids. Corresponding results from ab initio and density functional theory (DFT) methods with continuum-based treatments of solvation reveal deficiencies, particularly for protic solvents. Also summarized in this Account are three specific QM/MM applications to biomolecular systems: (1) a recent study that clarified the mechanism for the reaction of 2-pyrone derivatives catalyzed by macrophomate synthase as a tandem Michael-aldol sequence rather than a Diels-Alder reaction, (2) elucidation of the mechanism of action of fatty acid amide hydrolase (FAAH), an unusual Ser-Ser-Lys proteolytic enzyme, and (3) the construction of enzymes for Kemp elimination of 5-nitrobenzisoxazole that highlights the utility of QM/MM in the design of artificial enzymes. PMID:19728702

Acevedo, Orlando; Jorgensen, William L

2010-01-19

474

Enamel erosion by some soft drinks and orange juices relative to their pH, buffering effect and contents of calcium phosphate.  

PubMed

The capability of a soft drink or a juice to erode dental enamel depends not only on the pH of the drink, but also on its buffering effect. As the latter is the ability of the drink to resist a change of pH it may add to the effects of the actual pH. The aim of the present study was to compare the pH and the buffering effect of various soft drinks with their erosive effects and the solubility of apatite. In 18 soft drinks, mineral waters and juices available on the Danish market, pH and the concentrations of calcium, phosphate and fluoride were determined. The buffering effect was determined by titration with NaOH. Human teeth (n = 54) covered with nail varnish except for 3x4-mm windows were exposed to 1.5 liters of the drink for either 7 days or 24 h under constant agitation. The depth of the erosions was assessed in longitudinal sections. The depth was found to vary greatly from 3 mm eroded by the most acidic drinks and fresh orange juice to only slightly affected surfaces by most of the mineral waters. The dissolution of enamel increased logarithmically inversely with the pH of the drink and parallel with the solubility of enamel apatite. Orange juice, pH 4.0, supplemented with 40 mmol/l calcium and 30 mmol/l phosphate did not erode the enamel as the calcium and phosphate saturated the drink with respect to apatite. Generally, the lower the pH the more NaOH was necessary to bring the pH to neutrality. In particular the buffering effect of the juice was high. For all drinks, no effect of their low fluoride concentrations was observed. PMID:9831784

Larsen, M J; Nyvad, B

1999-01-01

475

Development of an MM5-Based Four Dimensional Variational Analysis System for Distributed Memory Multiprocessor Computers  

NASA Astrophysics Data System (ADS)

The MM5 four-dimensional variational analysis system (4DVAR) is being updated to allow its efficient execution on parallel distributed memory computers. The previous version of the MM5 4DVAR system (Zou et al. 1998 [3]) is coded for single processor computer architectures and its nonlinear, tangent-linear, and adjoint components are based on version 1 of the MM5. In order to take advantage of the parallelization mechanisms (Michalakes 2000 [2]) already in place for the latest release (Version 3.4) of the MM5 nonlinear model (NLM), the existing (Version 1) tangent linear (TLM) and adjoint model codes are also being updated to Version 3.4. We are using the Tangent Linear and Adjoint Model Compiler (TAMC; Giering and Kaminski 1988 [1]) in this process. The TAMC is a source-to-source translator that generates Fortran code for the TLM or adjoint from the Fortran code of the NLM. While it would be possible to incorporate the TAMC as part of a pre-compilation process--thus requiring the maintenance of the NLM code only--this would require that the NLM code first be modified as needed to result in the correct TLM and adjoint code output by TAMC. For the development of the MM5 adjoint, we have chosen instead to use TAMC as a development tool only, and separately maintain the TLM and adjoint versions of the model code. This approach makes it possible to minimize changes to the MM5 code as supported by NCAR. The TLM and adjoint are tested for correctness, using the standard comparison of the TLM and finite difference gradients to check for correctness of the former, and the definition of the adjoint to check for consistency of the TLM and adjoint. This testing is performed for individual subroutines (unit testing) as well as the complete model integration (unit integration testing), with objective functions designed to test different parts of the model state vector. Testing can be done for the entire model domain, or for selected model grid points. Finally, the TLM and adjoint components are adapted to multiple processor, DM computers by following the same methodology as used in the DM version of the MM5 (v3.4) NLM. The design of the parallel version of the TLM will closely follow that used for the NLM since both are similar in structure. In general, the parallel version of the adjoint model will make use of the same parallel programming principles employed in the forward models (i.e., horizontal domain decomposition, MPI-based communications); however, issues of establishing owner computes, possible false recursion, and disk I/O will need to be addressed. When complete, the components will be controlled with an incremental assimilation driver that will allow the 4DVAR system to be compatible with other mesoscale forecast models such as COAMPS and WRF. In addition, the final system will be delivered with observation operators for satellite instruments to make the system suitable for otherwise data denied areas. Project completion is scheduled for early 2003. References: R. Giering and T. Kaminski, 1998: ACM Trans. on Math. Software, 24(4):437-474. J.G. Michalakes, 2000: Scientific Programming, 8:5-12. X. Zou, W. Huang, and Q. Xiao, 1998: NCAR TN 437+IA, NCAR, Boulder, CO, 1997.

Nehrkorn, T.; Modica, G. D.; Cerniglia, M.; Ruggiero, F. H.; Michalakes, J. G.; Zou, X.

2001-05-01

476

The Effect of pH and Ion Channel Modulators on Human Placental Arteries  

PubMed Central

Chorionic plate arteries (CPA) are located at the maternofetal interface where they are able to respond to local metabolic changes. Unlike many other types of vasculature, the placenta lacks nervous control and requires autoregulation for controlling blood flow. The placental circulation, which is of low-resistance, may become hypoxic easily leading to fetal acidosis and fetal distress however the role of the ion channels in these circumstances is not well-understood. Active potassium channel conductances that are subject to local physicochemical modulation may serve as pathways through which such signals are transduced. The aim of this study was to investigate the modulation of CPA by pH and the channels implicated in these responses using wire myography. CPA were isolated from healthy placentae and pre-contracted with U46619 before testing the effects of extracellular pH using 1 M lactic acid over the pH range 7.4 - 6.4 in the presence of a variety of ion channel modulators. A change from pH 7.4 to 7.2 produced a 29±3% (n?=?9) relaxation of CPA which increased to 61±4% at the lowest pH of 6.4. In vessels isolated from placentae of women with pre-eclampsia (n?=?6), pH responses were attenuated. L-methionine increased the relaxation to 67±7% (n?=?6; p<0.001) at pH 6.4. Similarly the TASK 1/3 blocker zinc chloride (1 mM) gave a maximum relaxation of 72±5% (n?=?8; p<0.01) which compared with the relaxation produced by the TREK-1 opener riluzole (75±5%; n?=?6). Several other modulators induced no significant changes in vascular responses. Our study confirmed expression of several ion channel subtypes in CPA with our results indicating that extracellular pH within the physiological range has an important role in controlling vasodilatation in the human term placenta. PMID:25490401

Ali, Tayyba Y; Broughton Pipkin, Fiona; Khan, Raheela N

2014-01-01

477

Effect of Different pH Values on the Compressive Strength of Calcium-Enriched Mixture Cement  

PubMed Central

Introduction: The aim of this study was to evaluate the compressive strength of calcium-enriched mixture (CEM) cement in contact with acidic, neutral and alkaline pH values. Methods and Materials: The cement was mixed according to the manufacturer’s instructions, it was then condensed into fourteen split molds with five 4×6 mm holes. The specimens were randomly divided into 7 groups (n=10) and were then exposed to environments with pH values of 4.4, 5.4, 6.4, 7.4, 8.4, 9.4 and 10.4 in an incubator at 37° C for 4 days. After removing the samples from the molds, cement pellets were compressed in a universal testing machine. The exact forces required for breaking of the samples were recorded. The data were analyzed with the Kruskal-Wallis and Dunn tests for individual and pairwise comparisons, respectively. The level of significance was set at 0.05. Results: The greatest (48.59±10.36) and the lowest (9.67±3.16) mean compressive strength values were observed after exposure to pH value of 9.4 and 7.4, respectively. Alkaline environment significantly increased the compressive strength of CEM cement compared to the control group. There was no significant difference between the pH values of 9.4 and 10.4 but significant differences were found between pH values of 9.4, 8.4 and 7.4. The acidic environment showed better results than the neutral environment, although the difference was not significant for the pH value of 6.4. Alkaline pH also showed significantly better results than acidic and neutral pH. Conclusion: The compressive strength of CEM cement improved in the presence of acidic and alkaline environments but alkaline environment showed the best results.

Sobhnamayan, Fereshte; Sahebi, Safoora; Alborzi, Ali; Ghorbani, Saeed; Shojaee, Nooshin Sadat

2015-01-01

478

Maser and thermal methanol emission in the millimeter wave range: new masers at 1.3 mm and 2.8 mm  

E-print Network

Results of a survey of Galactic star-forming regions in the lines of methanol 8_{-1}-7_0E at 229.8 GHz, 3_{-2}-4_{-1}E at 230.0 GHz, 0_0-1_{-1}E at 108.9 GHz, and a series of methanol lines J_1-J_0E near 165 GHz are presented. Two masers, DR 21(OH) and DR 21West, and two maser candidates, L 379IRS3 and NGC 6334I(N), as well as 16 thermal sources are found at 229.8 GHz. This is the first detection of methanol masers at a wavelength as short as 1 mm. At 108.9 GHz, masers were found towards G345.01+1.79 and probably, towards M 8E. Thermal emission is found towards 28 objects. Only thermal emission was found at 165 and 230.0 GHz (20 and 7 sources, respectively). The masers at 229.8 GHz belong to class I, whereas those at 108.9 GHz belong to class II, according to the classification by Menten (1991). The masers in DR 21(OH) and DR 21West can be roughly fitted by models with the gas kinetic temperature of the order of 50K. The detection of the 108.9 GHz masers towards G345.01+1.79 and M 8E may indicate on a specific geometry of these objects. The combination of the existence of the class II J_0-J_{-1}E masers towards W 3(OH), G345.01+1.79, W 48, and Cep A and our non-detection of the 3_{-2}-4_{-1}E and J_1-J_0E lines is an evidence that the class II masers in these objects are pumped by the radiation of hot dust rather than by that of UC HII-regions.

S. V. Kalenskii; V. I. Slysh; I. E. Val'tts

2001-06-07

479

The panacea toolbox of a PhD biomedical student  

PubMed Central

Doing a PhD (doctor of philosophy) for the sake of contribution to knowledge should give the student an immense enthusiasm through the PhD period. It is the time in one’s life that one spends to “hit the nail on the head” in a specific area and topic of interest. A PhD consists mostly of hard work and tenacity; however, luck and genius might also play a little role. You can pass all PhD phases without having both luck and genius. The PhD student should have pre-PhD and PhD toolboxes, which are “sine quibus non” for getting successfully a PhD degree. In this manuscript, the toolboxes of the PhD student are discussed.

Skaik, Younis

2014-01-01

480

Six-Channel Spectrophotometers (PH) Onboard JEM-GLIMS  

NASA Astrophysics Data System (ADS)

Six-channel spectrophotometers (PH) are the science instruments of JEM-GLIMS to measure absolute intensity of the emission originated from lightning discharges and upper atmospheric transient luminous events (TLEs). PH unit-1 (PH-U1) consists of four spectrophotometer channels named from PH1 to PH4, while PH unit-2 (PH-U2) two spectrophotometer channels named PH5 and PH6. Optical filters of these spectrophotometers are selected to detect TLE emission lines of N2 1PG, N2 2PG, N2+ 1NG, and N2 LBH. Since the bandwidth of the optical filter of PH2, 3, 5, and 6 is 10 nm and since PH1 measures NUV emission, photomultiplier tubes with high-voltage converters are used as a photon detector. To the contrary, PH4 uses a photodiode as a photon detector because the pass-band of the optical filter is enough wide to detect transient optical emission. Though PH d