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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

Solubility and Leaching of Boron from Borax and Colemanite in Flooded Acidic Soils  

Microsoft Academic Search

Boron (B) is a micronutrient essential for adequate plant growth. Borax (Na2B4O710H2O) and colemanite (Ca2B6O115H2O) are common B fertilizer materials, the former being widely used worldwide. Boron is completely water soluble and subjected to leaching. In this study, the dissolution kinetics of both borax and colemanite in deionized water and at pH 3.8, 5.2, 6.5, and 8.2 were determined. Soils

M. Saleem; Y. M. Khanif; Y. M. Fauziah Ishak; A. W. Samsuri

2011-01-01

3

Assessment of boric acid and borax using the IEHR evaluative process for assessing human developmental and reproductive toxicity of agents  

SciTech Connect

This document presents an evaluation of the reproductive and developmental effects of boric acid, H3BO3 (CAS Registry No. 10043-35-3) and disodium tetraborate decahydrate or borax, Na2B4O2O(CAS Registry No. 1303-96-4). The element, boron, does not exist naturally. In dilute aqueous solution and at physiological pH (7.4), the predominant species in undissociated boric acid (greater than 98%), irrespective of whether the initial material was boric acid of borax. Therefore, it is both useful and correct to compare exposures and dosages to boric acid and borax in terms of `boron equivalents`, since both materials form equivalent species in dilute aqueous solution with similar systemic effects. In order to be clear in this document, the term `boron` will refer to `boron equivalents` or percent boron in boric acid and borax.

Moore, J.A.

1995-03-01

4

Borax Lake, a thermal lake confined within a biomorphic mound, Pueblo Valley, Oregon, USA  

Microsoft Academic Search

Relations among geothermal system dynamics, evolution of an 8-m thick biomorphic mound, and requirements to protect critical habitat of Gila boraxobius, a fish protected under the Endangered Species Act of 1973, were explored at Borax Lake, a shallow thermal lake in the tectonically active northwestern Basin-and-Range Province. Neutral pH, thermal water at ~105C discharges within a carrot-shaped vent at a

Michael L. Cummings; Sean D. Wilson; Anna M. St. John

2010-01-01

5

40 CFR 180.1121 - Boric acid and its salts, borax (sodium borate decahydrate), disodium octaborate tetrahydrate...  

Code of Federal Regulations, 2011 CFR

...2011-07-01 false Boric acid and its salts, borax (sodium borate decahydrate...Tolerances § 180.1121 Boric acid and its salts, borax (sodium borate decahydrate...pesticidal chemical boric acid and its salts, borax (sodium borate...

2011-07-01

6

40 CFR 180.1121 - Boric acid and its salts, borax (sodium borate decahydrate), disodium octaborate tetrahydrate...  

Code of Federal Regulations, 2012 CFR

...2012-07-01 false Boric acid and its salts, borax (sodium borate decahydrate...Tolerances § 180.1121 Boric acid and its salts, borax (sodium borate decahydrate...pesticidal chemical boric acid and its salts, borax (sodium borate...

2012-07-01

7

Assessment of boric acid and borax using the IEHR evaluative process for assessing human developmental and reproductive toxicity of agents  

Microsoft Academic Search

This document presents an evaluation of the reproductive and developmental effects of boric acid, H3BO3 (CAS Registry No. 10043-35-3) and disodium tetraborate decahydrate or borax, Na2B4O2O(CAS Registry No. 1303-96-4). The element, boron, does not exist naturally. In dilute aqueous solution and at physiological pH (7.4), the predominant species in undissociated boric acid (greater than 98%), irrespective of whether the initial

1995-01-01

8

Seizure disorders and anemia associated with chronic borax intoxication  

PubMed Central

During the course of investigation of two infants with seizure disorders it was discovered that both had been given large amounts of a preparation of borax and honey which resulted in chronic borate intoxication. In one child a profound anemia developed as well. The symptoms of chronic borate intoxication are different from those of the acute poisoning with which we are more familiar. The borax and honey preparations are highly dangerous and should no longer be manufactured or distributed for sale. ImagesFIG. 1FIG. 2

Gordon, A. S.; Prichard, J. S.; Freedman, M. H.

1973-01-01

9

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.

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

2009-01-01

10

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

11

Effect of borax on immune cell proliferation and sister chromatid exchange in human chromosomes  

PubMed Central

Background Borax is used as a food additive. It becomes toxic when accumulated in the body. It causes vomiting, fatigue and renal failure. Methods The heparinized blood samples from 40 healthy men were studied for the impact of borax toxicity on immune cell proliferation (lymphocyte proliferation) and sister chromatid exchange in human chromosomes. The MTT assay and Sister Chromatid Exchange (SCE) technic were used in this experiment with the borax concentrations of 0.1, 0.15, 0.2, 0.3 and 0.6 mg/ml. Results It showed that the immune cell proliferation (lymphocyte proliferation) was decreased when the concentrations of borax increased. The borax concentration of 0.6 mg/ml had the most effectiveness to the lymphocyte proliferation and had the highest cytotoxicity index (CI). The borax concentrations of 0.15, 0.2, 0.3 and 0.6 mg/ml significantly induced sister chromatid exchange in human chromosomes (P < 0.05). Conclusion Borax had effects on immune cell proliferation (lymphocyte proliferation) and induced sister chromatid exchange in human chromosomes. Toxicity of borax may lead to cellular toxicity and genetic defect in human.

Pongsavee, Malinee

2009-01-01

12

Quantum and experimental study on coal ash fusion with borax fluxing agent  

Microsoft Academic Search

Borax fluxing agent was added to four kinds of coal ash in terms of different quality ratios. The ash fusion test (AFT) of the mixtures of coal ash plus borax fluxing agent was carried out and the reactivity of mullite in coal ash was calculated by the density functional theory (DFT). The space group of the mullite is Pbam, belonging

Jie LI; Mei-fang DU; Bo YAN; Zhong-xiao ZHANG

2008-01-01

13

Drug delivery matrices based on scleroglucan/alginate/borax gels.  

PubMed

The aim of this work is to obtain a new drug delivery matrix, especially designed for protein delivery, based on biodegradable and biocompatible polymers, and to describe its main physico-chemical properties. A polysaccharide based semi-interpenetrating polymer network (semi-IPN) was built up, composed by sodium alginate chains interspersed into a scleroglucan/borax hydrogel network. Tablets were obtained by compression of the resulting freeze-dried hydrogel. The different release and physico-chemical properties possessed by the two starting polymers in various aqueous media were combined in the new matrix. In this work, description is given of the in vitro ability of the matrix to deliver in a controlled manner a protein, Myoglobin, in distilled water, simulated gastric fluid and simulated intestinal fluid; the release, simulating a gastric passage, followed by an enteric delivery, was also carried out. Water uptake data, colorimetric experiments and scanning electron microscopy images are given for the characterization of this new solid dosage form; the importance of the borax presence is also discussed. PMID:16554128

Matricardi, Pietro; Onorati, Ilenia; Coviello, Tommasina; Alhaique, Franco

2006-03-06

14

Guar gum and scleroglucan interactions with borax: experimental and theoretical studies of an unexpected similarity.  

PubMed

Guar gum is a galactomannan that assumes a very flexible conformation in solution, while Scleroglucan is a very rigid polysaccharide that dissolves in water as triple helices. Both polymers can form gels in the presence of borax. Despite their structural differences, the freeze-dried gel systems of both polymers, when compressed to form tablets, show a peculiar anisotropic swelling in water that reflects an amazing similarity in terms of their molecular properies. In this paper the behavior of the Guar/borax gel is compared with that of Scleroglucan/borax. The macroscopic properties of the two systems were characterized in terms of rheological measurements. Atomic force microscopy images and molecular dynamics simulation allowed to evaluate, at molecular level, the effect of borax addition to the Guar polymer. Both experiments show that an increasing of the polymer rigidity is produced by borax. The role played by galactose in the side chain was also discussed. PMID:20863102

Bocchinfuso, Gianfranco; Mazzuca, Claudia; Sandolo, Chiara; Margheritelli, Silvia; Alhaique, Franco; Coviello, Tommasina; Palleschi, Antonio

2010-10-21

15

Corrosion resistance of inconel 690 to borax, boric acid, and boron nitride at 1100°C  

Microsoft Academic Search

Significant general and localized corrosion was observed on Inconel 690 coupons following exposure to borax, boric acid and boron nitride at 1100°C. Severe localized attack at and below the melt line was observed on coupons exposed to borax. An intergranular attack at and below the melt line was observed on coupons exposed to borax. An intergranular attack (IGA) of the

Imrich

2010-01-01

16

Dual roles of borax in kinetics of calcium sulfate dihydrate formation.  

PubMed

An additive is not exclusively retardant or promoter for a crystallization system. The kinetic studies of calcium sulfate dihydrate (CSD) crystal growth demonstrated that borax played dual roles in the reaction, which accelerated CSD formations at the low concentration levels but inhibited the crystal growth at the high ones. In situ atomic force microscopy studies revealed that borax modulated the CSD crystallization via two different pathways: promoted the secondary nucleation to increase the step density on the growing crystal faces but simultaneously retarded the spread of these growth steps by the Langmuir adsorption. These two contradictory factors were incorporated in the crystallization, and their balance was regulated by the borax concentration. Both the macroscopic and microscopic experimental data nicely displayed the crystallization model of birth and spread that was able to account for the behaviors of borax in CSD formations. PMID:17385897

Jiang, Wenge; Pan, Haihua; Tao, Jinhui; Xu, Xurong; Tang, Ruikang

2007-03-27

17

Obtaining of Boron as an Alternative Fuel from Borax with Various Methods  

Microsoft Academic Search

This study examined how to obtain elemental boron from borax. For this purpose, first boric acid (H3BO3) was obtained from borax decahydrate with using HCl and H2SO4. The boric was then converted to boron oxide using a dehydration process. It has been studied to reduce the boric acid and the boron oxide into elemental boron with using the elemental magnesium

N. ?en; C. Demir; A. Demirbas; Y. Kar

2009-01-01

18

Borax counteracts genotoxicity of aluminum in rat liver.  

PubMed

This study was carried out to evaluate the protective role of borax (BX) on genotoxicity induced by aluminum (Al) in rat liver, using liver micronucleus assay as an indicator of genotoxicity. Sprague-Dawley rats were randomly separated into six groups and each group had four animals. Aluminum chloride (AlCl3; 5mg/kg b.w.) and BX (3.25 and 13mg/kg b.w.) were injected intraperitoneally to rats. Besides, animals were also treated with Al for 4 consecutive days followed by BX for 10 days. Rats were anesthetized after Al and BX injections and the hepatocytes were isolated for counting the number of micronucleated hepatocytes (MNHEPs). AlCl3 was found to significantly (p<0.05) increase the number of MNHEPs. Rats treated with BX, however, showed no increase in MNHEPs. Moreover, simultaneous treatments with BX significantly modulated the genotoxic effects of AlCl3 in rats. It can be concluded that BX has beneficial influences and has the ability to antagonize Al toxicity. PMID:22491726

Turkez, Hasan; Geyikoglu, Fatime; Tatar, Abdulgani

2012-04-04

19

3D Seismic and Magnetic characterization of the Borax Lake Hydrothermal System in the Alvord Desert, southeastern Oregon  

Microsoft Academic Search

As part of an interdisciplinary project aiming to study the link between the physical characteristics of hydrothermal systems and biota that occupy those systems, we are conducting a detailed geophysical characterization of an active hydrothermal system. The Borax Lake Hydrothermal System (BLHS), consisting of Borax Lake and the surrounding hot springs. BLHS is located near the center of the Alvord

S. Hess; J. Bradford; M. Lyle; P. Routh; L. Liberty; P. Donaldson

2004-01-01

20

Combustibility of Loose Fiber Fill Cellulose Insulation: the Role of Borax and Boric Acid  

Microsoft Academic Search

The influence of borax and boric acid on the resistance of cellulose insulation to smouldering and flaming combustion has been examined using material treated by a wet application process. Boric acid has been shown to be required at an add-on level of at least 11.6 parts to 100 parts (by weight) of cellulose if resistance to smouldering combustion by cigarette

M. Day; D. M. Wiles

1978-01-01

21

Association of reversible alopecia with occupational topical exposure to common borax-containing solutions  

Microsoft Academic Search

Boron is widely used in industrial materials, most frequently as the salt borax. Systemic exposure (eg, ingestion) to boron in boric acid been associated with reversible toxic alopecia among other manifestations. There is scant clinical literature on alopecia caused by topical exposure to boron. We observed a series of 3 patients in 2 workplaces who suffered reversible alopecia from cutaneous

William S. Beckett; Roger Oskvig; Mary Ellen Gaynor; Mark H. Goldgeier

2001-01-01

22

Sorption of boric acid and borax by activated carbon impregnated with various compounds  

Microsoft Academic Search

The separation of boron compounds, boric acid and borax from aqueous solution by activated carbon before and after impregnation with various compounds was studied. A series of activated carbons was prepared from coconut shell impregnated with calcium and barium chlorides, citric and tartaric acids. The examined processes were performed in batch and continuous systems under equilibrium and dynamic conditions. Impregnation

Lj. V. Rajakovi?; M. Dj. Risti?

1996-01-01

23

Impeller geometry effect on crystallization kinetics of borax decahydrate in a batch cooling crystallizer  

Microsoft Academic Search

The effects of impeller type and diameter in a batch cooling crystallizer on the nucleation and crystal growth kinetics as well as on the shape and size distribution of borax decahydrate crystals were investigated. Two different types of impellers of various sizes were applied. Chosen impeller configurations generate completely different fluid flow patterns in the crystallizer what allows to investigate

Marija Akrap; Nenad Kuzmani?; Jasna Prli? Kardum

24

Scleroglucan\\/borax: characterization of a novel hydrogel system suitable for drug delivery  

Microsoft Academic Search

A new hydrogel, with scleroglucan using borax as a crosslinker, has been prepared. The physical gel has been loaded with a model molecule (theophylline) and the release of the drug from the gel was evaluated. The same system was used to prepare tablets and the delivery of theophylline in different environmental conditions (HCl and SIF) was determined. A recent theoretical

T. Coviello; M. Grassi; R. Lapasin; A. Marino; F. Alhaique

2003-01-01

25

Scleroglucan-borax hydrogel: a flexible tool for redox protein immobilization.  

PubMed

A highly stable biological film was prepared by casting an aqueous dispersion of protein and composite hydrogel obtained from the polysaccharide Scleroglucan (Sclg) and borax as a cross-linking agent. Heme proteins, such as hemoglobin (Hb), myoglobin (Mb), and horseradish peroxidase (HRP), were chosen as model proteins to investigate the immobilized system. A pair of well-defined quasi-reversible redox peaks, characteristics of the protein heme FeII/FeIII redox couples, were obtained at the Sclg-borax/proteins films on pyrolytic graphite (PG) electrodes, as a consequence of the direct electron transfer between the protein and the PG electrode. A full characterization of the electron transfer kinetic was performed by opportunely modeling data obtained from cyclic voltammetry and square wave voltammetry experiments. The efficiency of our cross-linking approach was investigated by studying the influence of different borax groups percentage in the Sclg matrix, revealing the versatility of this hydrogel in the immobilization of redox proteins. The native conformation of the three heme proteins entrapped in the hydrogel films were proved to be unchanged, reflected by the unaltered Soret adsorption band and by the catalytic activity toward hydrogen peroxide (H2O2). The main kinetic parameters, such as the apparent Michaelis-Menten constant, for the electrocatalytic reaction were also evaluated. The peculiar characteristics of Sclg-borax matrix make it possible to find wide opportunities as proteins immobilizing agent for studies of direct electrochemistry and biosensors development. PMID:19694483

Frasconi, Marco; Rea, Sara; Matricardi, Pietro; Favero, Gabriele; Mazzei, Franco

2009-09-15

26

Scleroglucan\\/borax\\/drug hydrogels: Structure characterisation by means of rheological and diffusion experiments  

Microsoft Academic Search

This paper is aimed to the macro- and microscopic characterisation of a scleroglucanborax gel system eventually hosting model drugs. A rheological study was carried out, also as a function of temperature, on samples at different polymer concentrations in the presence and without guest model drug. Applying the generalised Maxwell model the mechanical spectra, showing the gel-like characteristics dependent on polymer

Mario Grassi; Romano Lapasin; Tommasina Coviello; Pietro Matricardi; Chiara Di Meo; Franco Alhaique

2009-01-01

27

A Human Health Risk Assessment of Boron (Boric Acid and Borax) in Drinking Water  

Microsoft Academic Search

A human health risk assessment was conducted to derive an appropriate safe exposure level in drinking water of inorganic boron-containing compounds (boric acid and borax). Several regulatory agencies have set or plan to set drinking water guidelines or standards for boron (B). Recent publication of reproductive and developmental toxicity studies by the National Toxicology Program prompted this risk assessment, along

F. Jay Murray

1995-01-01

28

The relationship of blood- and urine-boron to boron exposure in borax-workers and usefulness of urine-boron as an exposure marker.  

PubMed Central

Daily dietary-boron intake and on-the-job inspired boron were compared with blood- and urine-boron concentrations in workers engaged in packaging and shipping borax. Fourteen workers handling borax at jobs of low, medium, and high dust exposures were sampled throughout full shifts for 5 consecutive days each. Airborne borax concentrations ranged from means of 3.3 mg/m3 to 18 mg/m3, measured gravimetrically. End-of-shift mean blood-boron concentrations ranged from 0.11 to 0.26 microgram/g; end-of-shift mean urine concentrations ranged from 3.16 to 10.72 micrograms/mg creatinine. Creatinine measures were used to adjust for differences in urine-specific gravity such that 1 ml of urine contains approximately 1 mg creatinine. There was no progressive increase in end-of-shift blood- or urine-boron concentrations across the days of the week. Urine testing done at the end of the work shift gave a somewhat better estimate of borate exposure than did blood testing, was sampled more easily, and was analytically less difficult to perform. Personal air samplers of two types were used: one, the 37-mm closed-face, two-piece cassette to estimate total dust and the other, the Institute of Occupational Medicine (IOM) sampler to estimate inspirable particulate mass. Under the conditions of this study, the IOM air sampler more nearly estimated human exposure as measured by blood- and urine-boron levels than did the sampler that measured total dust.(ABSTRACT TRUNCATED AT 250 WORDS)

Culver, B D; Shen, P T; Taylor, T H; Lee-Feldstein, A; Anton-Culver, H; Strong, P L

1994-01-01

29

40 CFR 180.1121 - Boric acid and its salts, borax (sodium borate decahydrate), disodium octaborate tetrahydrate...  

Code of Federal Regulations, 2013 CFR

...2013-07-01 false Boric acid and its salts, borax (sodium borate decahydrate), disodium octaborate tetrahydrate, boric oxide (boric anhydride), sodium borate and sodium metaborate; exemptions from the requirement of...

2013-07-01

30

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

31

Corrosion resistance of inconel 690 to borax, boric acid, and boron nitride at 1100{degrees}C  

SciTech Connect

Significant general and localized corrosion was observed on Inconel 690 coupons following exposure to borax, boric acid and boron nitride at 1100{degrees}C. Severe localized attack at and below the melt line was observed on coupons exposed to borax. An intergranular attack at and below the melt line was observed on coupons exposed to borax. An intergranular attack (IGA) of the Inconel 690 was also observed. Severe internal void formation and IGA (30 mils penetration after 3 days) was observed in the coupon exposed to boric acid. Both borax and boric acid remove the protective chromium oxide; however, this layer can be reestablished by heating the Inconel 690 to 975 {degrees}C in air for several hours. Inconel 690 in direct contact with boron nitride resulted in the formation of a thick chromium borate layer, a general corrosion rate of 50 to 90 mils per year, and internal void formation of 1 mil per day.

Imrich, K.J.

1996-12-12

32

In vivo percutaneous absorption of boron as boric acid, borax, and disodium octaborate tetrahydrate in humans  

Microsoft Academic Search

Literature from the first half of this century reports concern for toxicity from topical use of boric acid, but assessment\\u000a of percutaneous absorption has been impaired by lack of analytical sensitivity. Analytical methods in this study included\\u000a inductively coupled plasma-mass spectrometry, which now allows quantitation of percutaneous absorption of10B in10B-enriched boric acid, borax, and disodium octaborate tetrahydrate (DOT) in biological

Ronald C. Wester; Xiaoying Hui; Howard I. Maibach; Kathleen Bell; Michael J. Schell; D. Jack Northington; Philip Strong; B. Dwight Culver

1998-01-01

33

Vanadium carbide coating growth on die steel substrate in borax salt bath  

Microsoft Academic Search

Vanadium pentoxide, borax, boron carbide and sodium fluoride were used to grow vanadium carbide coating on die steel(Cr12, Cr12MoV) surface at 950 C by TD process, which extended the life period of Cr12 and Cr12MoV as punching die. Kinetics of vanadium carbide coating growth was brought forward and verified by comparison of the mathematical\\u000a model with the experimental results. The

Hongfu Wang; Huachang Wang; Chenggang Pan

2010-01-01

34

Structural and rheological characterization of Scleroglucan\\/borax hydrogel for drug delivery  

Microsoft Academic Search

The polysaccharide Scleroglucan, one of the most rigid polymers found in nature, can form a chemical\\/physical gel, in the presence of borax. The obtained hydrogel was loaded with three different model molecules (Theophylline, Vitamin B12 and Myoglobin) and then, after freeze-drying, was used as a matrix for tablets. The release profiles of the substances from the dosage forms were evaluated;

Tommasina Coviello; Gina Coluzzi; Antonio Palleschi; Mario Grassi; Eleonora Santucci; Franco Alhaique

2003-01-01

35

Investigation on a new scleroglucan/borax hydrogel: structure and drug release.  

PubMed

The aim of this work is to elucidate the structure of the new hydrogel prepared with scleroglucan (Sclg) and borax, suitable for drug delivery, applying theoretical approaches, and to explain its very peculiar swelling. The possible linkages with borate ions have been investigated and original parameters for the 4,6-gluco-borate moiety have been introduced. The structures relative to the Sclg chains in the presence of borax and the possible mutual arrangements among the triple helices are given. According to molecular dynamics simulations, the most probable assembly of the chains in the network is proposed, without and in the presence of three tested model drugs with different molecular dimensions: theophylline (TPH), Vitamin B12 (Vit. B12) and myoglobin (MGB). The hydrogel supramolecular structure, formed via chemical and physical linkages among the polysaccharidic chains, is built up taking into account the steric hindrance of the entrapped molecules. It is shown that molecular dynamics analysis can be a useful tool capable to shed some light on the anomalous swelling of the hydrogel, suitable for drug release, giving a new insight on the network structure and the release rate of the guest molecules. PMID:16806759

Palleschi, Antonio; Coviello, Tommasina; Bocchinfuso, Gianfranco; Alhaique, Franco

2006-05-22

36

Some physical, biological, mechanical, and fire properties of wood polymer composite (WPC) pretreated with boric acid and borax mixture  

Microsoft Academic Search

Wood polymer composite (WPC) was obtained by vinyl monomers such as styrene (ST), methylmethacrylate (MMA), and their mixture (50:50; volume:volume) of treated sapwood of Scots pine (Pinus sylvestris L.). Boric acid (BA) and borax (BX) mixture was impregnated into wood at 1% concentration prior to monomer treatment. Wood polymer composite with and without BA and BX mixture pretreatment was evaluated

Ergun Baysal; Mustafa Kemal Yalinkilic; Mustafa Altinok; Abdullah Sonmez; Hseyin Peker; Mehmet Colak

2007-01-01

37

The effects of dietary boric acid and borax supplementation on lipid peroxidation, antioxidant activity, and DNA damage in rats  

Microsoft Academic Search

The aims of this study were to clarify the effects of high dietary supplementation with boric acid and borax, called boron (B) compounds, on lipid peroxidation (LPO), antioxidant activity, some vitamin levels, and DNA damage in rats. Thirty Sprague Dawley male rats were divided into three equal groups: the animals in the first group (control) were fed with a standard

Sinan Ince; Ismail Kucukkurt; Ibrahim Hakki Cigerci; A. Fatih Fidan; Abdullah Eryavuz

2010-01-01

38

Assessment of Boric Acid and Borax Using the IEHR Evaluative Process for Assessing Human Developmental and Reproductive Toxicity of Agents.  

National Technical Information Service (NTIS)

This document presents an evaluation of the reproductive and developmental effects of boric acid, H3BO3 (CAS Registry No. 10043-35-3) and disodium tetraborate decahydrate or borax, Na2B4O2O(CAS Registry No. 1303-96-4). The element, boron, does not exist n...

J. A. Moore

1995-01-01

39

Preparation and characterization of antimicrobial wound dressings based on silver, gellan, PVA and borax.  

PubMed

Silver-loaded dressings are designed to provide the same antimicrobial activity of topical silver, with the advantages of a sustained silver release and a reduced number of dressing changes. Moreover, such type of dressing must provide a moist environment, avoiding fiber shedding, dehydration and adherence to the wound site. Here we describe the preparation of a novel silver-loaded dressing based on a Gellan/Hyaff() (Ge-H) non woven, treated with a polyvinyl alcohol (PVA)/borax system capable to enhance the entrapment of silver in the dressing and to modulate its release. The new hydrophilic non woven dressings show enhanced water uptake capability and slow dehydration rates. A sustained silver release is also achieved. The antibacterial activity was confirmed on Staphylococcus aureus and Pseudomonas aeruginosa. PMID:22939352

Cencetti, C; Bellini, D; Pavesio, A; Senigaglia, D; Passariello, C; Virga, A; Matricardi, P

2012-07-11

40

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

41

Structural and rheological characterization of Scleroglucan/borax hydrogel for drug delivery.  

PubMed

The polysaccharide Scleroglucan, one of the most rigid polymers found in nature, can form a chemical/physical gel, in the presence of borax. The obtained hydrogel was loaded with three different model molecules (Theophylline, Vitamin B12 and Myoglobin) and then, after freeze-drying, was used as a matrix for tablets. The release profiles of the substances from the dosage forms were evaluated; the matrix appeared capable to modulate the diffusion of the chosen molecules, and different diffusion rates were observed, according to the different radii of the tested molecules. Interestingly, in the dissolution medium the matrix undergoes an anisotropic swelling taking place only in the axial direction, while a negligible radial variation occurs. The water uptake of the matrix occurs according to a Fickian process. Samples at two different polymer concentrations (0.7 and 2.3%, w/v) were characterized in terms of rheological and mechanical parameters and the properties were interpreted in terms of the molecular structure obtained by conformational analysis. The flow curves acquired in the viscoelasticity interval, show the effect of the borate ion in improving the resistance of the gel in comparison to the polymer alone. The evaluation of the moduli indicates that the system is viscoelastic, with an appreciable liquid component that increases as the polymer concentration decreases. Also the cohesion of the gel is higher in comparison to the Scleroglucan and is strongly dependent on temperature. The combination of experimental and theoretical conformational analysis approaches, allowed us to propose a model for the structure of the macromolecular network and to give an explanation to the anomalous swelling that was observed. It came out that the polymer can built up a channel structure, mediated via borax ion interaction, that can accommodate guest molecules of different size. PMID:12957304

Coviello, Tommasina; Coluzzi, Gina; Palleschi, Antonio; Grassi, Mario; Santucci, Eleonora; Alhaique, Franco

2003-09-01

42

In vitro percutaneous absorption of boron as boric acid, borax, and disodium octaborate tetrahydrate in human skin  

Microsoft Academic Search

Literature from the first half of this century reports concern for toxicity from topical use of boric acid, but assessment\\u000a of percutaneous absorption has been impaired by lack of analytical sensitivity. Analytical methods in this study included\\u000a inductively coupled plasmamass spectrometry which now allows quantitation of percutaneous absorption of10B in10B-enriched boric acid, borax and disodium octaborate tetrahydrate (DOT) in biological

Ronald C. Wester; Tracy Hartway; Howard I. Maibach; Michael J. Schell; D. Jack Northington; B. Dwight Culver; Philip L. Strong

1998-01-01

43

Scleroglucan/borax: characterization of a novel hydrogel system suitable for drug delivery.  

PubMed

A new hydrogel, with scleroglucan using borax as a crosslinker, has been prepared. The physical gel has been loaded with a model molecule (theophylline) and the release of the drug from the gel was evaluated. The same system was used to prepare tablets and the delivery of theophylline in different environmental conditions (HCl and SIF) was determined. A recent theoretical approach has been applied to the dissolution profiles obtained from the tablets and a satisfactory agreement has been found with the experimental data. Furthermore, the diffusion coefficient of the model molecule was evaluated according to a suitable strategy that was tested on two set of data obtained with different set-ups (permeation and diffusion experiments). A simplified mathematical approach allows to reduce the two-dimensional problem of the Fick's second law in a one-dimensional system leading to a much easier handling of the data without loosing the accuracy of the original problem in two dimensions. The characterization of the gel has been also carried out following the kinetics of swelling in terms of water uptake. PMID:12711526

Coviello, T; Grassi, M; Lapasin, R; Marino, A; Alhaique, F

2003-07-01

44

A new scleroglucan/borax hydrogel: swelling and drug release studies.  

PubMed

The aim of the work was the characterization of a new polysaccharidic physical hydrogel, obtained from Scleroglucan (Sclg) and borax, following water uptake and dimension variations during the swelling process. Furthermore, the release of molecules of different size (Theophylline (TPH), Vitamin B12 (Vit. B12) and Myoglobin (MGB)) from the gel and from the dried system used as a matrix for tablets was studied. The increase of weight of the tablets with and without the loaded drugs was followed together with the relative variation of the dimensions. The dry matrix, in the form of tablets was capable, during the swelling process, to incorporate a relevant amount of solvent (ca. 20 g water/g dried matrix), without dissolving in the medium, leading to a surprisingly noticeable anisotropic swelling that can be correlated with a peculiar supramolecular structure of the system induced by compression. Obtained results indicate that the new hydrogel can be suitable for sustained drug release formulations. The delivery from the matrix is deeply dependent on the size of the tested model drugs. The experimental release data obtained from the gel were satisfactorily fitted by an appropriate theoretical approach and the relative drug diffusion coefficients in the hydrogel were estimated. The release profiles of TPH, Vit. B12 and MGB from the tablets have been analyzed in terms of a new mathematical approach that allows calculating of permeability values of the loaded drugs. PMID:15652203

Coviello, Tommasina; Grassi, Mario; Palleschi, Antonio; Bocchinfuso, Gianfranco; Coluzzi, Gina; Banishoeib, Fateme; Alhaique, Franco

2004-12-25

45

Impact of the propylene glycol-water-borax coolant on material recovery operations  

SciTech Connect

The reaction of the propylene glycol-water-borax coolant with nitric acid has now been studied in some detail. This document is intended to provide a summary of the results. Findings are summarized under nine headings. Tests have also been conducted to determine if the new coolant would have any adverse effects on the uranium recycle systems. Experiments were scientifically designed after observation of the production operations so that accurate response to the immediate production concerns could be provided. Conclusions from these studies are: formation of glycol nitrates is very improbable; the reaction of concentrated (70%) nitric acid with pure propylene glycol is very violent and hazardous; dilution of the nitric acid-glycol mixture causes a drastic decrease in the rate and intensity of the reaction; the mechanism of the nitric acid propylene glycol reaction is autocatalytic in nitrous acid; no reaction is observed between coolant and 30% nitric acid unless the solution is heated; the coolant reacts fairly vigorously with 55% nitric acid after a concentration-dependent induction time; experiments showed that the dissolution of uranium chips that had been soaked in coolant proceeded at about the same rate as if the chips had not previously contacted glycol; thermodynamic calculations show that the enthalpy change (heat liberated) by the reaction of nitric acid (30%) with propylene glycol is smaller than if the same amount of nitric acid reacted with uranium. Each of these conclusions is briefly discussed. The effect of new coolant on uranium recycle operations is then briefly discussed.

Duerksen, W.K.; Taylor, P.A.

1983-05-01

46

Study of the effect of adding the powder of waste PET bottles and borax pentahydrate to the urea formaldehyde adhesive applied onplywood  

Microsoft Academic Search

In the present study, the effect of adding the powder of waste PET (polyethylene terephthalate) bottles and borax pentahydrate\\u000a in equal amounts to the urea-formaldehyde (UF) adhesive on the bonding characteristics and free formaldehyde content was studied.\\u000a Experiments were conducted on three layered plywood of beech (Fagus orientalis) and poplar (Populus x eureamericana), which were produced using urea-formaldehyde adhesive to

Murat Ozalp

47

Accidental mold\\/termite testing of high density fiberboard (HDF) treated with boric acid, borax and N'-N-naphthoylhydroxylamine (NHA)  

Microsoft Academic Search

High density fibreboard (HDF) was made from beech and pine furnish (50:50) and treated with boric acid (0.1-3%), borax (0.1-3%) or N'-N-(1,8-naphthalyl) hydroxylamine (NHA) (0.1-1%) prior to gluing with urea formaldehyde (UF) resin in order to determine resistance to Eastern subterranean termites ( Reticulitermes flavipes Kollar), the most economically important termite species in North America. HDF and southern yellow pine

S. Nami Kartal; Harold S. Burdsall; Frederick Green Ill

48

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

49

Borax: An Ecofriendly and Efficient Catalyst for One-Pot Synthesis of 3,4-Dihydropyrimidine-2(1H)-ones under Solvent-Free Conditions  

Microsoft Academic Search

Borax in the presence of a very small amount of 5M sulfuric acid efficiently catalyses the three-component condensation of an aldehyde, ?-ketoester, and urea or thiourea to afford the corresponding 3,4-dihydropyrimidin-2(1H)-ones or 3,4-dihydropyrimidin-2(1H)-thiones in good to excellent yields under solvent-free conditions at 80C. Compared with the classical Biginelli reaction conditions, this new method has the advantage of excellent yield, short

Jayashree Nath; Mihir K. Chaudhuri

2010-01-01

50

200-mm SCALPEL mask development  

NASA Astrophysics Data System (ADS)

SCALPEL is a tue 4X reduction technology that capabilities on high resolution capabilities from electron beam exposure and high throughput capabilities from projection printing. Current mask blank fabrication for SCALPEL technology use widely available 100 mm, crystalline silicon wafers. The use of 100 mm crystalline wafers and a wet, through wafer etch process causes the patterned strut width to increase as the wafer is etched and must be accounted for in the mask blank fabrication process. In the wet etch process, a 100 micrometers wide strut grows to 800 micrometers at the strut-membrane interface. As a consequence, the maximum printable die size due to the wafer size and the decreased amount of open area between each strut is 8 X 8 mm. Additionally, crystal defects in the silicon wafer affect the wet etch process and contribute to mask blank failures. A partial solution for an increased die size is to increase the wafer size used to make the SCALPEL mask blank. A 200 mm wafer is capable of producing large die sizes. This can be further improved by dry etching of the grill structure to form struts with vertical sidewalls. As a result, due sizes of 25 X 25 mm or 16 X 32.5 mm can be produced depending on the grill pattern used. However, use of large wafers and dry etching for mask blank formation has significant issues that must be addressed. Among the issues to be addressed are etch chemistries, etch mask materials, and wafer handling.

Bogart, Gregory R.; Novembre, Anthony E.; Kornblit, Avi; Peabody, Milton L.; Farrow, Reginald C.; Blakey, Myrtle I.; Kasica, Richard J.; Liddle, James A.; Saunders, Thomas E.; Knurek, Chester S.; Johnston, I.

1999-06-01

51

MM5-HPAC simulation experiments  

NASA Astrophysics Data System (ADS)

We evaluate mesoscale model predicted boundary-layer flow and the subsequent HPAC (Hazard Prediction and Assessment Capability) dispersion computation. The HPAC software allows for prediction of the effects of surface release of hazardous material into the atmosphere and collateral damage on civilian populations using either observed or numerical weather model data. The advanced mesoscale weather model MM5 was employed in the study. The real-data MM5 model simulations were verified with high-resolution observations from the West Texas Mesonet. MM5 worked well in simulating meteorologically relatively quiescent conditions. We examined the sensitivity of HPAC computations to the MM5 models grid resolution, lateral boundary conditions, and input weather data. Results suggest that the MM5-HPAC conjugation can provide useful prediction of airborne transport of hazardous materials near the surface. However, the accuracy of diffusion computations strongly depends on the performance of MM5, which in turn is likely to be a function of weather scenarios. A given state-of-the-art mesoscale model may perform well in some cases but not in others. There is a potential benefit of using several different model winds separately to run HPAC. A composite result of the HPAC runs could give a more comprehensive depiction of the transport of surface hazardous agents.

Chang, C.-B.; Gill, T. E.

2005-09-01

52

40mm Floating Flare Development.  

National Technical Information Service (NTIS)

The 40mm Floating Flare can be launched from either the M79 or the M203 Grenade Launcher and provides troops with a standoff capability for marking a target or position in inundated areas during hours of darkness. The flotation capability is achieved by a...

D. W. Renfroe

1973-01-01

53

Development of 8 mm digital camcorder system  

Microsoft Academic Search

We have developed an 8 mm-digital camcorder system which allows users to record extremely high quality video and audio signals onto Hi8-MP 8mm tapes. We have also developed an automatic detector and high precision scanner for 8 mm-digital\\/analog8 so that this system has upper compatibility with the conventional analog 8mm VCR system

Y. Kotani; M. Kumagawa; Y. Senshu; K. Iesaka; K. Kobayashi

1999-01-01

54

Functional photoacoustic microscopy of pH  

NASA Astrophysics Data System (ADS)

pH is a tightly regulated indicator of metabolic activity. In mammalian systems, imbalance of pH regulation may result from or result in serious illness. Even though the regulation system of pH is very robust, tissue pH can be altered in many diseases such as cancer, osteoporosis and diabetes mellitus. Traditional high-resolution optical imaging techniques, such as confocal microscopy, routinely image pH in cells and tissues using pH sensitive fluorescent dyes, which change their fluorescence properties with the surrounding pH. Since strong optical scattering in biological tissue blurs images at greater depths, high-resolution pH imaging is limited to penetration depths of 1mm. Here, we report photoacoustic microscopy (PAM) of commercially available pH-sensitive fluorescent dye in tissue phantoms. Using both opticalresolution photoacoustic microscopy (OR-PAM), and acoustic resolution photoacoustic microscopy (AR-PAM), we explored the possibility of recovering the pH values in tissue phantoms. In this paper, we demonstrate that PAM was capable of recovering pH values up to a depth of 2 mm, greater than possible with other forms of optical microscopy.

Chatni, M. Rameez; Yao, Junjie; Danielli, Amos; Favazza, Christopher P.; Maslov, Konstantin I.; Wang, Lihong V.

2012-02-01

55

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.

56

A 5 mm 5 mm 1.37 mm hermetic FBAR duplexer for PCS handsets with wafer-scale packaging  

Microsoft Academic Search

We describe the design and measured performance of a 5 mm 5 mm 1.37 mm antenna duplexer for the U.S. PCS band (Tx: 1850-1910 MHz, Rx: 1930-1990 MHz) for cellular handsets based on FBAR (film acoustic resonator) technology. The FBARs are fabricated in a silicon-based IC process technology and are hermetically sealed in a wafer-level packaging process. Two dice, Tx

P. D. Bradley; R. Ruby; A. Barfknecht; F. Geefay; C. Han; G. Gan; Y. Oshmyansky

2002-01-01

57

40MM Target Marker (Floating), TMF-1.  

National Technical Information Service (NTIS)

This is the Final Report of the 40MM Target Marker (Floating), TMF-1, program. The purpose of this program was to prove the feasibility of and to design, develop and test a floatable target marker in a 40mm configuration that can be fired from either the ...

J. A. D'Andrea

1971-01-01

58

A Toddler's Treatment of "Mm" and "Mm Hm" in Talk with a Parent  

ERIC Educational Resources Information Center

The study to be reported in this paper examined the work accomplished by "mm" and "mm hm" in the interactions of a parent and his daughter aged 0;10-2;0. Using the findings of Gardner (2001) for adults, the analysis shows that "mm" accomplished a range of functions based on its sequential placement and prosodic features, whereas "mm hm" was much

Filipi, Anna

2007-01-01

59

M&M Model for Radioactive Decay  

NSDL National Science Digital Library

A tasty in-class demonstration of radioactive decay using two colors of M&M's. Illustrates the quantitative concepts of probability and exponential decay. This activity is appropriate for small classes (<40 students).

Wenner, Jennifer

60

Iapetus's SED from 3-11 mm  

NASA Astrophysics Data System (ADS)

Several observations were made of Saturn's moon Iapetus using the NRAO Green Bank Telescope (GBT) using the MUSTANGW-band (3.3mm) bolomoter and the Ka-band (7.5-11mm) CCB instrument in order to constrain its spectral energy distribution (SED). Observations show a severe decrement in brightness temperature at some wavelengths, but the location of the decrement shifts depending on the sub-observer longitude.

Ries, P.

2011-10-01

61

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

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

1998-10-01

62

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

63

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

64

PCM Audio IC's for 8 mm Video  

Microsoft Academic Search

We have developed four kinds of ICs for use in the PCM audio system of 8mm VIDEO. Only one 2K-byte RAM is used to construct the entire system. Moreover, they can be used in record\\/playback and NTSC\\/CCIR modes.

Hiroshi Miyaguchi; Kazuo Hasegawa; Shigetaka Sawa; Shigeo Saji

1984-01-01

65

SSC 50 mm dipole cross section  

Microsoft Academic Search

In this paper we present the magnetic design of the two dimensional coil and iron cross section, referred to as DSX201\\/W6733, for the 50 mm aperture main ring dipole magnet for the Superconducting Super Collider (SSC). The computed values of the allowed field harmonics as a function of current, the quench performance predictions, the stored energy calculations, the effect of

R. C. Gupta; S. A. Kahn; G. H. Morgan

1991-01-01

66

MM 602 Parish: Outside the Walls  

Microsoft Academic Search

MM601-602 Handbook (available for free via One ATS or a hardcopy can be purchased through the Mentored Ministry office for $5.00) A Many Colored Kingdom (2004), Conde-Frazier, Kang, & Parrett same kind of different as me (2006), Hall & Moore Movie clips may be selected from the following list or other relevant movies that come on the scene during the

Chris Kiesling

2009-01-01

67

The new 800mm reflecting telescope  

Microsoft Academic Search

The design and capabilities of the 800-mm Ritchey-Chretien system are described. The optical system of the telescope has an aperture ratio of 1:8; is suitable for photography in a 1.5 deg field with photoplates of 16 x 16 cm; and consists of primary and secondary hyperbolically deformed mirrors. The attachment of the mirrors, position rotator, and offset guider to the

Hans-Joachim Teske

1986-01-01

68

mm-wave evanescent mode oscillator  

NASA Astrophysics Data System (ADS)

Design and performance features of mm-wave evanescent mode waveguide (EMWG) oscillators are summarized. EMWGs supply passbands below the cutoff point and are known to store magnetic energy. If capacitive elements such as Gunn or IMPATT diodes are added to the lumped element oscillator resonance conditions arise and are tuned by matching diode and load impedances, transferring the EMWG signal to a series or shunt load and by selecting the biasing arrangement. Tests results are provided for 30 and 40 GHz oscillators.

Bharj, S.

1985-05-01

69

pH Game  

NSDL National Science Digital Library

The purpose of this resource is to teach students about the acidity levels of liquids and other substances around their school so they understand what pH levels tell us about the environment. Students will create mixtures of water samples, soil samples, plants and other natural materials to better understand the importance of pH levels.

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

2003-08-01

70

Keratometric comparison of 4.0 mm and 5.5 mm scleral tunnel cataract incisions.  

PubMed

Postoperative keratometric astigmatism was analyzed in 276 consecutive cases of phacoemulsification and posterior chamber lens implantation performed by one surgeon. The series was divided into two groups: one received 4.0 mm incisions and the other 5.5 mm incisions. Incision design was triplanar and required suture closure, i.e., all wounds were closed with two X-pattern 10-0 nylon sutures. Using the Cravy method, an insignificant difference in induced astigmatism was found between the groups at one day, two weeks, and one year after surgery. The average induced diopters of astigmatism for the 4.0 mm group was +0.80 +/- 0.94 at one day, +0.49 +/- 0.73 at two weeks, and -0.34 +/- 0.91 at one year; for the 5.5 mm group it was +0.69 +/- 1.07 at one day, +0.41 +/- 0.85 at two weeks, and -0.23 +/- 1.01 at one year. Two-week uncorrected visual acuity of 20/40 or better was similar for both groups. Seventy-six percent of the 4.0 mm group and 68% of the 5.5 mm group had acuities of 20/40 or better. A significant difference in the incidence of immediate postoperative hyphema was noted. The overall hyphema incidence was 9%, with a 14% and 4% incidence for 5.5 mm and 4.0 mm incisions, respectively. PMID:8426317

Davison, J A

1993-01-01

71

mmView: a web-based viewer of the mmCIF format  

PubMed Central

Background Structural biomolecular data are commonly stored in the PDB format. The PDB format is widely supported by software vendors because of its simplicity and readability. However, the PDB format cannot fully address many informatics challenges related to the growing amount of structural data. To overcome the limitations of the PDB format, a new textual format mmCIF was released in June 1997 in its version 1.0. mmCIF provides extra information which has the advantage of being in a computer readable form. However, this advantage becomes a disadvantage if a human must read and understand the stored data. While software tools exist to help to prepare mmCIF files, the number of available systems simplifying the comprehension and interpretation of the mmCIF files is limited. Findings In this paper we present mmView - a cross-platform web-based application that allows to explore comfortably the structural data of biomacromolecules stored in the mmCIF format. The mmCIF categories can be easily browsed in a tree-like structure, and the corresponding data are presented in a well arranged tabular form. The application also allows to display and investigate biomolecular structures via an integrated Java application Jmol. Conclusions The mmView software system is primarily intended for educational purposes, but it can also serve as a useful research tool. The mmView application is offered in two flavors: as an open-source stand-alone application (available from http://sourceforge.net/projects/mmview) that can be installed on the user's computer, and as a publicly available web server.

2011-01-01

72

Urine pH  

MedlinePLUS

... Drugs that can decrease urine pH include ammonium chloride, thiazide diuretics, and methenamine mandelate. Eat a normal, ... is associated with xanthine, cystine, uric acid , and calcium oxalate stones. Alkaline urine is associated with calcium ...

73

The laboratory spectroscopy of true line shape in MM\\/SubMM range  

Microsoft Academic Search

The report deals with precision measurement of spectroscopic parameters, which can be extracted from the shape of observed molecular lines. Two spectrometers in their modem versions are described. Both spectrometers are based on MM\\/SubMM backward-wave oscillator (BWO) tubes phase-locked against harmonic of frequency standard. The first one is automated spectrometer with acoustical detection (RAD) of radiation absorption operating in pressure

M. Yu. Tretyakov; Nizhny Novgorod

2004-01-01

74

Comparison of 150-mm versus 100-mm visual analogue scales in free living adult subjects  

Microsoft Academic Search

The aim of this study was to verify whether appetite sensation scores obtained from 150-mm visual analogue scales (VAS) can be compared to those obtained from 100-mm scales. On one occasion, using a within-subject design, 25 participants (mean age: 42.213.3 years, mean body mass index: 22.92.3kg\\/m2) recorded their appetite sensations before lunch, and at five additional time points during the

Jean-Philippe Chaput; Jo-Anne Gilbert; Nikolaj T. Gregersen; Sue D. Pedersen; Anders M. Sjdin

2010-01-01

75

Monoclonal antibody inhibiting creatine kinase MM3 but not isoform MM1.  

PubMed

Monoclonal antibody CKM-G01 inhibited greater than 99% of the activity of porcine and human creatine kinase(CK)-MM isoenzyme purified from muscle. However, it inhibited only 54% of CK-MM in human serum. Chromatofocusing of serum CK-MM showed that CKM-G01 inhibited 100% of MM3 but not isoform MM1. CKM-G01 inhibited CK-MM2 by 57%. CKM-G01 specifically inhibited only the original CK-M subunit and not the subunit modified by removal of C-terminal lysine by carboxypeptidase N. CKM-G01 can be used for assay of CK isoforms. We devised a new diagnostic reagent involving it, which requires no analytical separation of isoforms, based on the immunoinhibition method, and applied it to early diagnosis of acute myocardial infarction. The "inhibition index," (inhibited CK activity/total CK activity) x 100, increased more rapidly than did total CK and CK-MB. Evidently this diagnostic reagent can be used for easy, early diagnosis of acute myocardial infarction. PMID:2297910

Suzuki, T; Shiraishi, T; Tomita, K; Totani, M; Murachi, T

1990-01-01

76

Comparison of 150-mm versus 100-mm visual analogue scales in free living adult subjects.  

PubMed

The aim of this study was to verify whether appetite sensation scores obtained from 150-mm visual analogue scales (VAS) can be compared to those obtained from 100-mm scales. On one occasion, using a within-subject design, 25 participants (mean age: 42.2 + or - 13.3 years, mean body mass index: 22.9 + or - 2.3 kg/m(2)) recorded their appetite sensations before lunch, and at five additional time points during the postprandial period. At each time point, both VAS (150 mm and 100 mm) were used to record desire to eat, hunger, fullness, satiety, and prospective food consumption. The VAS in the same booklet were completed immediately one after the other in a randomized order to eliminate the order effect. We observed that the immediate, successive completion of questionnaires varying in length resulted in no significant difference in appetite markers, with a strong linear relationship between the two tools (r from 0.80 to 0.98, P<0.01). We conclude that VAS scores obtained from 150-mm to 100-mm length scales are interchangeable, both before and in response to a meal. PMID:20138943

Chaput, Jean-Philippe; Gilbert, Jo-Anne; Gregersen, Nikolaj T; Pedersen, Sue D; Sjdin, Anders M

2010-02-04

77

The new 800mm reflecting telescope  

NASA Astrophysics Data System (ADS)

The design and capabilities of the 800-mm Ritchey-Chretien system are described. The optical system of the telescope has an aperture ratio of 1:8; is suitable for photography in a 1.5 deg field with photoplates of 16 x 16 cm; and consists of primary and secondary hyperbolically deformed mirrors. The attachment of the mirrors, position rotator, and offset guider to the tube, which is a truss structure, is examined. The mount for the telescope is an equatorial fork type. The electronic control system is a 16-bit microcomputer system; the functions of the control system are discussed. The 8-m polyester dome of the telescope consists of a supporting steel structure carrying shell elements of glass fiber-reinforced polyester resins. Consideration is given to the auxiliary devices of the telescope.

Teske, Hans-Joachim

78

Lowering of cytoplasmic pH is essential for growth of Streptococcus faecalis at high pH.  

PubMed Central

The growth of Streptococcus faecalis at high pH was significantly stimulated by carbonate. In the absence of added carbonate the cells were unable to grow at a pH above 9.5, but in media containing 50 mM HCO3- they grew even at pH 10.5. Both rate and yield of growth at pH 9.5 were significantly stimulated by as little as 5 mM carbonate. The cytoplasmic pH in growing cells was maintained at about 7.8 to 8.2, whereas the medium pH ranged from 8.4 to 9.5. Nigericin and gramicidin D, ionophores which conduct protons, blocked growth at pH 9.5 but not at pH 7.5. These results indicate that lowering of the cytoplasmic pH is essential for the growth of this organism at high pH.

Kakinuma, Y

1987-01-01

79

Single-pulse driven plasma Pockels cell with 350mm350mm aperture  

NASA Astrophysics Data System (ADS)

Large-aperture plasma Pockels cell is one of important components for inertial confinement fusion laser facility. We demonstrate a single-pulse driven PPC with 350mm350mm aperture. It is different to the PPC of NIF and LMJ for its simple operation to perform Pockels effect. With optimized operation parameters, the PPC meets the optical switching requirement of SGII update laser facility. Only driven by one high voltage pulser, the simplified PPC system would be provided with less associated diagnostics, less the maintenance, and higher reliability.

Zhang, Xiongjun; Wu, Dengsheng; Zhang, Jun; Lin, Donghui; Zheng, Kuixing; Jing, Feng

2010-08-01

80

Pentameric CRP attenuates inflammatory effects of mmLDL by inhibiting mmLDL--monocyte interactions.  

PubMed

Previous studies have reported that C-reactive protein (CRP) interacting with low-density lipoproteins (LDL) affects macrophage activation and LDL uptake. However, the physiological relevance of CRP-LDL interaction with circulating monocytes remains elusive. Moreover, recent studies have shown that CRP exists in two isoforms with partly opposing characteristics pentameric (pCRP) and monomeric CRP (mCRP). Here we investigated the effects of CRP interacting with minimally modified low-density lipoprotein (mmLDL) interaction in regard to events involved in formation of atherosclerotic plaque. We analyzed the effect of mmLDL on human monocytes and found a substantial increase in monocyte activation as evaluated by CD11b/CD18 expression and increased monocyte adhesion under static and under shear flow conditions to human endothelial cells. Monocyte adhesion and activation was attenuated by pCRP via the prevention of mmLDL binding to monocytes. These anti-inflammatory properties of pCRP were lost when it dissociates to the monomeric form. Our results elucidate the physiological relevance of the CRP-mmLDL interaction and furthermore confirm the importance of the previously described pCRP dissociation to mCRP as a localized inflammatory "activation" mechanism. PMID:22901456

Eisenhardt, Steffen U; Starke, Julia; Thiele, Jan R; Murphy, Andrew; Bjrn Stark, G; Bassler, Nicole; Sviridov, Dmitri; Winkler, Karl; Peter, Karlheinz

2012-08-10

81

Osmolytes Contribute to pH Homeostasis of Escherichia coli  

PubMed Central

Background Cytoplasmic pH homeostasis in Escherichia coli includes numerous mechanisms involving pH-dependent catabolism and ion fluxes. An important contributor is transmembrane K+ flux, but the actual basis of K+ compensation for pH stress remains unclear. Osmoprotection could mediate the pH protection afforded by K+ and other osmolytes. Methods and Principal Findings The cytoplasmic pH of E. coli K-12 strains was measured by GFPmut3 fluorimetry. The wild-type strain Frag1 was exposed to rapid external acidification by HCl addition. Recovery of cytoplasmic pH was enhanced equally by supplementation with NaCl, KCl, proline, or sucrose. A triple mutant strain TK2420 defective for the Kdp, Trk and Kup K+ uptake systems requires exogenous K+ for steady-state pH homeostasis and for recovery from sudden acid shift. The K+ requirement however was partly compensated by supplementation with NaCl, choline chloride, proline, or sucrose. Thus, the K+ requirement was mediated in part by osmolarity, possibly by relieving osmotic stress which interacts with pH stress. The rapid addition of KCl to strain TK2420 suspended at external pH 5.6 caused a transient decrease in cytoplasmic pH, followed by slow recovery to an elevated steady-state pH. In the presence of 150 mM KCl, however, rapid addition of another 150 mM KCl caused a transient increase in cytoplasmic pH. These transient effects may arise from secondary K+ fluxes occurring through other transport processes in the TK2420 strain. Conclusions Diverse osmolytes including NaCl, KCl, proline, or sucrose contribute to cytoplasmic pH homeostasis in E. coli, and increase the recovery from rapid acid shift. Osmolytes other than K+ restore partial pH homeostasis in a strain deleted for K+ transport.

Kitko, Ryan D.; Wilks, Jessica C.; Garduque, Gian M.; Slonczewski, Joan L.

2010-01-01

82

Manufacturing Technology for Production of 80-mm-Input, 40-mm-Output (80/40) Image Intensifier Tubes.  

National Technical Information Service (NTIS)

Manufacturing techniques were established for fabricating image intensifier tubes with 80-mm input and 40-mm output, suitable for interface with the 40-mm SEC camera tube. The manufacturing processes, techniques and controls necessary to fabricate a limit...

1970-01-01

83

Transmural pH gradient in canine myocardial ischemia.  

PubMed

The subendocardium is more susceptible to ischemia than the subepicardium. Studies during critical coronary stenosis have demonstrated subendocardial hypoperfusion relative to the subepicardium and transmural gradients in certain tissue metabolites. Although ischemia causes acidosis, the existence of a transmural pH gradient has never been demonstrated or quantitated. Thus we reduced coronary blood flow to 20 +/- 5% of normal in eight open chest anesthetized (morphine sulfate and pentobarbital) dogs and to 45 +/- 5% in two dogs. We implanted specially designed miniature fiber-optic pH probes in normal and ischemic subendocardium (depth 5.5-8 mm) and subepicardium (depth 3-4 mm). Separate experiments validated use of the fiber-optic pH probe system to measure tissue pH. Although both probes were located in the ischemic zone, there was a large transmural gradient, i.e., from normal pH values (7.36) in the subepicardium to severely acidotic (pH 6.94) 2 mm deeper in the subendocardium. This marked difference in pH between nearby transmural layers may have important implications regarding arrhythmogenesis in the setting of acute myocardial ischemia. PMID:6696134

Watson, R M; Markle, D R; Ro, Y M; Goldstein, S R; McGuire, D A; Peterson, J I; Patterson, R E

1984-02-01

84

MM90 : a scalable parallel implementation of the Penn State/NCAR Mesoscale Model (MM5).  

SciTech Connect

This paper describes MM90, a parallel regional weather model based on the Penn State/NCAR MM5. Parallelization of finite differencing, horizontal interpolation, and nesting on distributed-memory (message passing) computers is handled transparently using the RSL library package. Fortran90 modules, derived data types, dynamic memory allocation, pointers, and recursion are used, making the code modular, flexible, extensible, and run-time configurable. The model can dynamically sense and correct load imbalances. The paper provides performance, scaling, and load-balancing data collected on the IBM SP2 computers at Argonne National Laboratory and NASA Ames Laboratory. Future work will address the impact of parallel modifications on existing modeling software; an approach using commercially available source translation software is described.

Michalakes, J.; Mathematics and Computer Science

1997-01-01

85

The mm and sub-mm wave planar antenna arrays for SIS detectors  

NASA Astrophysics Data System (ADS)

The design, construction and tests of planar antennas and arrays suitable for integration with SIS (superconducting tunnel junctions) in the sub mm wavelength regime are discussed. Two different types of planar antennas are investigated, both with and without the use of lenses. It is concluded that log periodic antennas are very wideband but suffer from irregular beam shapes and a large degree of cross polarization. The dipoles are more narrow band and have low cross polarization and regular, symmetric beam patterns.

van de Stadt, Herman; De Graauw, Thijs; Skalare, A.

1990-12-01

86

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 (139149 mM NaCl) buffered with 515 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 12

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

2005-01-01

87

Determining photoresist coat sensitivities of 300-mm wafers  

NASA Astrophysics Data System (ADS)

This paper presents preliminary data on 300 nm wafer coatings by comparing photoresist coats on 150 nm, 200 mm and 300 mm wafers. Conventional methods of applying photoresist have ben prove effective on wafers with diameters up to 200 nm. How well 150 mm and 200 mm coating processes apply to 300 mm substrates is the focus of this paper. Spin speed versus photoresists thickness curves will be reviewed for all three wafer sizes.Additionally, two major coating uniformity factors, photoresist and cool plate temperature, will be studied for 200 mm and 300 mm wafers.

Crowell, Robert M.

1998-06-01

88

PhET: Research  

NSDL National Science Digital Library

This web page contains links to published research articles relating to the Physics Education Technology Project (PhET). This project provides technology-based resources and information for physics education, most notably, simulations on a wide range of topics including Newton's Laws, electricity, waves, light, and quantum physics. The simulations are developed in conjunction with careful research to enhance their effectiveness as learning tools.

Project, The P.

2009-02-10

89

40 CFR Table Mm-2 to Subpart Mm of... - Default Factors for Biomass-Based Fuels and Biomass  

Code of Federal Regulations, 2013 CFR

... 2013-07-01 false Default Factors for Biomass-Based Fuels and Biomass MM Table MM-2 to Subpart MM of Part 98 ...to Subpart MM of Part 98Default Factors for Biomass-Based Fuels and Biomass Biomass-based...

2013-07-01

90

The mm/submm spectrum of Galilean satellites  

NASA Astrophysics Data System (ADS)

In order to constrain physical parameters of the sub-surface of the Galilean satellites, simulations of the disk-averaged brightness temperature in the mm/submm wavelength range have been performed and compared with our recent observations obtained at the IRAM-PdB and SMA interferometers. The first step was to develop a thermal model of the sub-surface, based upon the Spencer etal (1989) algorithm. This model solves the heat diffusion equation in the planetary surface material as a function of longitude, latitude and depth. The thermal inertia used was originally derived by Spencer 1987 (PhD) from 2 layer models. For this work the grid resolution in latitude and longitude was 2.5 degrees, and 128 vertical layers were considered, from the surface down to 10 meters. A broadband ('continuum') emission map for each body was then computed with our radiative transfer code, which solves the radiative transfer equations in the sub-surface (Muhleman and Berge, 1991) on a horizontal grid of 100 X 100 points. For a given sub-solar longitude, we have used as an input temperature the values computed in the thermal model for each longitude, latitude and depth. The parameters of the radiative transfer models are (i) the absorption length Kl, expressed in units of the wavelength (ii) the surface dielectric constant and (iii) the surface roughness (degrees), expressed as the rms dispersion of the local surface slope angle. The output of this computation is the brightness map of the planet. Spatial integration of the map is also performed, providing the disk-averaged brightness temperature which can be directly compared with the observations. The models and the observations will be presented.

Moreno, Raphael; Gurwell, M. A.; Moullet, A.; Lellouch, E.

2008-09-01

91

Comparative analysis between 5 mm and 7.5 mm collimators in CyberKnife radiosurgery for trigeminal neuralgia  

PubMed Central

Trigeminal neuralgia (TN) is treated in CyberKnife (Accuray Inc, Sunnyvale, USA) with the 5 mm collimator whose dosimetric inaccuracy is higher than the other available collimators. The 7.5 mm collimator which is having less dosimetric uncertainty can be an alternative for 5 mm collimator provided the dose distribution with 7.5 mm collimator is acceptable. Aim of this study is to analyze the role of 7.5 mm collimator in CyberKnife treatment plans of TN. The treatment plans with 5 mm collimators were re-optimized with 7.5 mm collimator and a bi-collimator system (5 mm and 7.5 mm). The treatment plans were compared for target coverage, brainstem doses, and the dose to normal tissues. The target and brainstem doses were comparable. However, the conformity indices were 2.31 0.52, 2.40 0.87 and 2.82 0.51 for 5 mm, bi-collimator (5mm and 7.5 mm), 7.5 mm collimator plans respectively. This shows the level of dose spillage in 7.5 mm collimator plans. The 6 Gy dose volumes in 7.5 mm plans were 1.53 and 1.34 times higher than the 5 mm plan and the bi-collimator plans respectively. The treatment time parameters were lesser for 7.5 mm collimators. Since, the normal tissue dose is pretty high in 7.5 mm collimator plans, the use of it in TN plans can be ruled out though the treatment time is lesser for these 7.5 mm collimator plans.

Sudahar, H.; Kurup, P. G. G.; Murali, V.; Velmurugan, J.

2013-01-01

92

Perforated Brake Efficiency Measurements Using a 20-mm Cannon.  

National Technical Information Service (NTIS)

Over the past few years, several field experiments have been performed using 105-mm and 120-mm cannons having perforated muzzle brakes. Significant differences in impulse reduction and gasdynamic efficiency have been reported in tests using the same 105-m...

G. C. Carofano

1993-01-01

93

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

94

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

95

Electronic camera-management system for 35-mm and 70-mm film cameras  

NASA Astrophysics Data System (ADS)

Military and commercial test facilities have been tasked with the need for increasingly sophisticated data collection and data reduction. A state-of-the-art electronic control system for high speed 35 mm and 70 mm film cameras designed to meet these tasks is described. Data collection in today's test range environment is difficult at best. The need for a completely integrated image and data collection system is mandated by the increasingly complex test environment. Instrumentation film cameras have been used on test ranges to capture images for decades. Their high frame rates coupled with exceptionally high resolution make them an essential part of any test system. In addition to documenting test events, today's camera system is required to perform many additional tasks. Data reduction to establish TSPI (time- space-position information) may be performed after a mission and is subject to all of the variables present in documenting the mission. A typical scenario would consist of multiple cameras located on tracking mounts capturing the event along with azimuth and elevation position data. Corrected data can then be reduced using each camera's time and position deltas and calculating the TSPI of the object using triangulation. An electronic camera control system designed to meet these requirements has been developed by Photo-Sonics, Inc. The feedback received from test technicians at range facilities throughout the world led Photo-Sonics to design the features of this control system. These prominent new features include: a comprehensive safety management system, full local or remote operation, frame rate accuracy of less than 0.005 percent, and phase locking capability to Irig-B. In fact, Irig-B phase lock operation of multiple cameras can reduce the time-distance delta of a test object traveling at mach-1 to less than one inch during data reduction.

Nielsen, Allan

1993-01-01

96

300 mm fab automation technology options and selection criteria  

Microsoft Academic Search

Fab automation is being widely applied in 200 mm fabs. With the advent of new carrier designs, and equipment standards being set for 300 mm tools, opportunities arise for new and more efficient methods to transport, store, and load 300 mm carriers. This can result in more expansive yet simplified uses of automation and in a large variety of options

Mitchell Weiss

1997-01-01

97

The 300 mm silicon wafer a cost and technology challenge  

Microsoft Academic Search

The conversion to 300 mm wafers is strictly cost driven. Cost, capability and timing are still the major challenges during this shaky transition phase. Looking back to 1995, industry consortia decided that the next wafer size would be 300 mm and all major Si manufacturers started to invest in costly 300 mm pilot lines. Even during the recent recession, they

Peter O. Hahn

2001-01-01

98

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

...for Petroleum Products and Natural Gas Liquids 1 2 MM Table MM-1 to Subpart MM...for Petroleum Products and Natural Gas Liquids 1 2 Products Column A: density...Other Petroleum Products and Natural Gas Liquids Aviation Gasoline 0.1120...

2011-07-01

99

The FM Audio Signal Recording System for 8 mm Video  

Microsoft Academic Search

The 8 mm Video standard was determined by the Working Groups in 8 mm Video Conference which is composed of tuany companies in the world in March, 1983. The 8 mm Video system aims to achieve a small-sized & light-weighted design, a good quality picture and a high quality sound. Metal head and metal powder( MP)\\/evaporated(ME) tape improve a recording

Yoshizumi Watatani; Shigeyuki Itoh; Akira Shibata; Katsuo Mohri

1984-01-01

100

Unified tool communication specification for 300 mm automated fab  

Microsoft Academic Search

In 300 mm diameter wafer fabrication line, concrete infrastructure that enables high degree of line operation is essential to minimize the cost and the risk of new 300 mm fab infrastructure and integration. Equipment online communication is an essential technology as fab infrastructure. Based on CIM-GJG and SEMI standards, Selete (Semiconductor Leading Edge Technologies, Inc.) has been developed unified process

S. Kono; T. Masui; Y. Ohyama

2001-01-01

101

300 mm Conversion challenge and breakthrough for future semiconductor manufacturing  

Microsoft Academic Search

The status regarding the planned conversion of the semiconductor industry to the larger and more productive 300 mm wafer size is reviewed. Many efforts are already underway to aid the conversion to 300 mm wafers. In addition to the consortiums in both U.S. and Japan, targeted at working with the equipment manufacturers and standard setting, SEMICONDUCTOR300, a joint venture between

P. Kuecher; D. Tuft; K. Roithner; M. Hiatt

1999-01-01

102

512X512 mm Two-Coordinate Proportional Chamber.  

National Technical Information Service (NTIS)

Description and performances of a two-coordinate module of proportional chambers of 512x512 mm are presented. The pitch of signal wires is 2 mm. The chambers have high uniformity of performances in area; supporting wires are not used. The detectors are in...

V. N. Afonas'ev V. P. Chernyshev V. D. Peshekhonov

1979-01-01

103

Yarn mass analysis with 1 mm capacitive sensors  

Microsoft Academic Search

This paper presents the advantages of analysing yarn evenness, based on mass variation, using a capacitive sensor which allows the measurement of 1 mm yarn length. The variation of capacity is due to the dielectric change and is proportional to the quantity of yarn mass between the sensor plates. Available commercial equipment uses a solution of 8 mm with the

V. Carvalho; J. Monteiro; R. M. Vasconcelos; F. O. Soares

2004-01-01

104

Public Library Subject Headings for 16mm Motion Pictures. Revised.  

ERIC Educational Resources Information Center

Suggested subject headings for 16mm motion pictures are listed. The intent of the list is to provide audiovisual librarians with a tool which will aid them in making subject indexes for their printed catalogs. It is also intended as an authority for professional catalogers who may be called upon to catalog 16mm motion pictures. (Author/KKC)

California Library Association, Sacramento.

105

A 1.6-mm, metal tube ultrasonic motor  

Microsoft Academic Search

A miniaturized metal tube ultrasonic motor, the dimensions of which are 1.6 mm in diameter and 6 mm in length, was developed. Two flattened surfaces with 90 degrees were ground on the outer surface of the stator. Two PZT-based piezoelectric ceramics were bonded onto these flat surfaces. The asymmetrical surface of the stator developed the split of the two degenerated

Serrn Cagatay; Burbanettin Koc; K. Uchino

2003-01-01

106

Initial results from 50mm short SSC dipoles at Fermilab  

Microsoft Academic Search

Several short model SSC 50 mm bore dipoles are being built and tested at Fermilab. Mechanical design of these magnets has been determined from experience involved in the construction and testing of 40 mm dipoles. Construction experience includes coil winding, curing and measuring, coil end part design and fabrication, ground insulation, instrumentation, collaring and yoke assembly. Fabrication techniques are explained

R. C. Bossert; J. S. Brandt; J. A. Carson; K. Coulter; S. Delchamps; K. D. Ewald; H. Fulton; I. Gonczy; S. A. Gourlay; T. S. Jaffery; W. Kinney; W. Koska; M. J. Lamm; J. B. Strait; M. Wake; M. Gordon; N. Hassan; R. Sims; M. Winters

1991-01-01

107

Radio Sources: 3.3mm Flux and Variability Measurements.  

National Technical Information Service (NTIS)

Graphical and tabular summaries of 3.3-mm (90-GHz) flux measurements of 35 discrete galactic and extragalactic sources are presented, including results of extensive monitoring of nine sources. Variability at 3.3-mm is certain for NGC 1068, NGC 1275, 3C120...

E. E. Epstein J. W. Montgomery M. M. Dworetsky W. G. Fogarty

1971-01-01

108

Is smaller better? Comparison of 3-mm and 5-mm leaf size for stereotactic radiosurgery: A dosimetric study  

SciTech Connect

Purpose: To perform a dosimetric comparison of a minimal 3-mm leaf width multileaf collimator (MLC) and a minimal 5-mm MLC in dynamic conformal arc stereotactic radiosurgery for treatment of intracranial lesions. Methods and Materials: The treatment plans of 23 patients previously treated for intracranial lesions in our institution were redone using the BrainSCAN, version 5.3, stereotactic radiosurgery treatment planning system (BrainLAB). For each case, two dynamic conformal arc plans were generated: one using a minimal 3-mm micro-MLC (BrainLAB, Novalis) and one using a minimal 5-mm MLC (Varian Millennium). All arc parameters were the same in each of the two plans, except for the collimator angle settings. The collimator angle settings were optimized for each arc in each plan. A peritumoral rind structure (1 cm) was created to evaluate normal tissue sparing immediately adjacent to the target volume. Conformity indexes (CIs) were calculated for each plan. The dependence of normal tissue sparing and target conformity on target volume (TV) was determined. Results: The TV was 0.14-36.32 cm{sup 3} (median, 5.90). The CI was 1.22-2.60 (median, 1.51) for the 3-mm micro-MLC and 1.23-2.69 (median, 1.60) for the 5-mm MLC. Despite this small difference, it was a statistically significant increase (p < 0.0001) for the 5-mm MLC compared with the 3-mm micro-MLC. Improved normal tissue sparing was demonstrated using the 3-mm micro-MLC compared with the 5-mm MLC by examining the peritumoral rind volumes (PRVs) receiving 50% (PRV{sub 5}), 80% (PRV{sub 8}), and 90% (PRV{sub 9}) of the prescription dose. The reduction in the PRV{sub 5}, PRV{sub 8}, and PRV{sub 9} for the 3-mm micro-MLC compared with the 5-mm MLC was 13.5%, 12.9%, and 11.5%, respectively. The CI decreased with a larger TV, as did the difference in the CIs between the 3-mm micro-MLC and 5-mm MLC. A reduction in the PRV increased with larger TVs. Conclusion: The 3-mm micro-MLC provided better target conformity and greater normal tissue sparing than the 5-mm MLC in stereotactic radiosurgery using dynamic conformal arcs. These differences were small but consistent in the patients examined. Future research is needed to determine whether this small improvement can yield a clinical impact on patient care.

Chern, Shyh-shi [Department of Radiation Oncology, University of Utah School of Medicine, Salt Lake City, Utah (United States)]. E-mail: Richard.Chern@hci.utah.edu; Leavitt, Dennis D. [Department of Radiation Oncology, University of Utah School of Medicine, Salt Lake City, Utah (United States); Jensen, Randy L. [Department of Neurosurgery, University of Utah School of Medicine, Salt Lake City, Utah (United States); Shrieve, Dennis C. [Department of Radiation Oncology, University of Utah School of Medicine, Salt Lake City, Utah (United States)

2006-11-15

109

Pacemaker current changes during intracellular pH transients in sheep cardiac Purkinje fibres  

Microsoft Academic Search

1.Intracellular acidosis, at constant extracellular pH, hyperpolarizes the resting potential and reduces the diastolic depolarization rate of cardiac Purkinje fibres. With alkaline pHi, the fibre depolarizes and spontaneous firing is observed.2.Intracellular pH transients induced either by superfusion with Tyrode buffered with 5% CO2\\/23 mM HCO3- or 16% CO2\\/61 mM HCO3-, or with solutions containing weak undissociated acids, transiently shifted the

P. P. Van Bogaert

1985-01-01

110

PH as a stress signal  

Microsoft Academic Search

The pH of the xylem sap of plants experiencing a range of environmental conditions can increase by over a whole pH unit. This results in an increased ABA concentration in the apoplast adjacent to the stomatal guard cells in the leaf epidermis, by reducing the ability of the mesophyll and epidermal symplast to sequester ABA away from this compartment. As

Sally Wilkinson

1999-01-01

111

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

112

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

113

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.

114

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.

115

Monograph on Borax, Boric Acid, and Borates.  

National Technical Information Service (NTIS)

The monographs summarize the available scientific literature from 1920 to 1978 related to the safety of food ingredients. Chemical information, biological data, and biochemical aspects are given. Other individual monographs are also available:

R. Handler

1978-01-01

116

Test Comparison for 20mm Perforated Muzzle Brakes.  

National Technical Information Service (NTIS)

Tests were conducted at the Ballistic Research Laboratory for a 20mm perforated muzzle brake. Six muzzle brake designs were analyzed for their influence on muzzle velocity, blast overpressure, and brake efficiency. The designs were a combination of scaled...

D. S. Savick

1993-01-01

117

Storage of fuelwood chips in fraction 25-30 mm  

SciTech Connect

The purpose of this investigation was to study storage of fuelwood chips in the fraction 25 - 30 mm. Dry matter loss, moisture content, temperature, basic density and the amount of fungal particles were studied.

Bjoerklund, L.

1982-01-01

118

Advanced Applications Flight Equipment (Aafe) 125MM Ultraviolet Spectrometer.  

National Technical Information Service (NTIS)

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.

R. J. Schroeder

1973-01-01

119

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

120

Design and Manufacture of 155-mm Modular Propelling Charges.  

National Technical Information Service (NTIS)

Molded 155-mm propellant containers of two different lengths which could fit together to form propelling charges of varying sizes and an end cap containing the ignition charge were designed and manufactured. The end cap was capable of withstanding loading...

J. E. Haley

1984-01-01

121

Cast Ductile Iron 155mm M804 Bodies.  

National Technical Information Service (NTIS)

This report describes the foundry process for the production of the cast ductile iron 155 mm M804 practice projectile. The process covers the vertical airset molding, vertical pouring and induction melting. This report contains inspection, physical, chemi...

B. Twomey C. Casad I. Chambliss W. Thomas

1990-01-01

122

Injection Molded Plastic Obturator for 105-mm M735 Projectile.  

National Technical Information Service (NTIS)

The objective of the contract was the development of a nonproprietary, low cost, production process for nylon obturators for the 105-mm M735 projectile that would give product performance equivalent to that obtained from current production machined from c...

S. B. King M. Connor

1983-01-01

123

Propellant Residues Deposition from Firing of 40-mm Grenades.  

National Technical Information Service (NTIS)

Military live-fire training utilizes energetic materials that are never completely consumed. In February 2010, tests were conducted at Fort Richardson, Alaska, to determine the propellant residues deposition rates related to the firing of 40-mm grenades f...

J. W. Hug K. L. Foley M. E. Walsh M. R. Walsh S. R. Bigl

2010-01-01

124

8-mm wave multichannel video and audio transmission system  

Microsoft Academic Search

An experimental transmission system at 8mm-wave was built up to perform a multi-channel transmission of audio and video signals in frequency reuse, due to space separation and polarization isolation. The features of such an 8mm-wave communication systems is described in details with respect to system construction and performance. Based on carrier-to- noise ratio and the signal level available, the attenuation

W. D. Chen; Edward K. Yung; Y. O. Yam; H. Y. Ding

1996-01-01

125

Development of the high-band 8 mm video system  

Microsoft Academic Search

To satisfy the demand for high-quality camcorder pictures, new tape, head, and circuits to deal with 0.5-?m recording have been developed. Improved recording and editing features are implemented by introducing an improved ME (metal evaporated) tape. The high-band 8-mm video format is characterized by a higher carrier frequency, wider deviation, and a shorter pre-emphasis time constant than the basic 8-mm

K. Tsuneki; T. Ezaki; J. Hirai; Y. Kubota

1989-01-01

126

QM/MM Investigations Of Organic Chemistry Oriented Questions.  

PubMed

About 35 years after its first suggestion, QM/MM became the standard theoretical approach to investigate enzymatic structures and processes. The success is due to the ability of QM/MM to provide an accurate atomistic picture of enzymes and related processes. This picture can even be turned into a movie if nuclei-dynamics is taken into account to describe enzymatic processes. In the field of organic chemistry, QM/MM methods are used to a much lesser extent although almost all relevant processes happen in condensed matter or are influenced by complicated interactions between substrate and catalyst. There is less importance for theoretical organic chemistry since the influence of nonpolar solvents is rather weak and the effect of polar solvents can often be accurately described by continuum approaches. Catalytic processes (homogeneous and heterogeneous) can often be reduced to truncated model systems, which are so small that pure quantum-mechanical approaches can be employed. However, since QM/MM becomes more and more efficient due to the success in software and hardware developments, it is more and more used in theoretical organic chemistry to study effects which result from the molecular nature of the environment. It is shown by many examples discussed in this review that the influence can be tremendous, even for nonpolar reactions. The importance of environmental effects in theoretical spectroscopy was already known. Due to its benefits, QM/MM can be expected to experience ongoing growth for the next decade.In the present chapter we give an overview of QM/MM developments and their importance in theoretical organic chemistry, and review applications which give impressions of the possibilities and the importance of the relevant effects. Since there is already a bunch of excellent reviews dealing with QM/MM, we will discuss fundamental ingredients and developments of QM/MM very briefly with a focus on very recent progress. For the applications we follow a similar strategy. PMID:22392477

Schmidt, Thomas C; Paasche, Alexander; Grebner, Christoph; Ansorg, Kay; Becker, Johannes; Lee, Wook; Engels, Bernd

2012-03-01

127

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

128

Exercise and Pulmonary Hypertension (PH)  

MedlinePLUS

... Yoamna and Scott's Wedding Fight for the Cause Online Sometimes its PH: An Early Diagnosis Campaign Raise Awareness with Your Social Networks Facebook Fundraising Volunteer Volunteer Form Volunteer Profiles ...

129

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.

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

1996-01-01

130

PhEDEx Data Service  

NASA Astrophysics Data System (ADS)

The PhEDEx Data Service provides access to information from the central PhEDEx database, as well as certificate-authenticated managerial operations such as requesting the transfer or deletion of data. The Data Service is integrated with the "SiteDB" service for fine-grained access control, providing a safe and secure environment for operations. A plug-in architecture allows server-side modules to be developed rapidly and easily by anyone familiar with the schema, and can automatically return the data in a variety of formats for use by different client technologies. Using HTTP access via the Data Service instead of direct database connections makes it possible to build monitoring web-pages with complex drill-down operations, suitable for debugging or presentation from many aspects. This will form the basis of the new PhEDEx website in the near future, as well as providing access to PhEDEx information and certificate-authenticated services for other CMS dataflow and workflow management tools such as CRAB, WMCore, DBS and the dashboard. A PhEDEx command-line client tool provides one-stop access to all the functions of the PhEDEx Data Service interactively, for use in simple scripts that do not access the service directly. The client tool provides certificate-authenticated access to managerial functions, so all the functions of the PhEDEx Data Service are available to it. The tool can be expanded by plug-ins which can combine or extend the client-side manipulation of data from the Data Service, providing a powerful environment for manipulating data within PhEDEx.

Egeland, Ricky; Wildish, Tony; Huang, Chih-Hao

2010-04-01

131

The build-up of backscatter in the energy range 1 mm Al to 8 mm Al HVT (radiotherapy beams)  

Microsoft Academic Search

Little information is available on the influence of the thickness of underlying material on the magnitude of the backscatter factor and investigations were therefore undertaken. Radiation beam qualities between 1 mm Al to 8 mm Al half-value thickness (HVT) and source-to-surface distances (SSD) applicable to contemporary superficial radiotherapy were used. Measurements of the backscatter were made in a polystyrene phantom

S. C. Klevenhagen

1982-01-01

132

The same-source parallel MM{sub 5}.  

SciTech Connect

The set of architectures available to users of the Penn State/NCAR MM5 has been expanded to included distributed-memory parallel computers, providing cost-effective scalable performance and memory capacity for large problem sizes. The same-source approach uses high-level parallel library and source-translation technology for adapting MM5, simplifying maintenance and allowing new physics modules to be incorporated without modification. The approach facilitates maintenance of the DM-parallel option to MM5 as an option within the official version, rather than as a separate stand-alone version. As a result, the DM-parallel option to MM5 (now at Version 3.1) has been a part of six subsequent model releases since MM5 Version 2.8 in March 1998. The same-source approach is applicable to other, similarly constructed codes when there is a need or desire to develop the code for distributed memory parallel machines without impacting the pre-existing source code. The approach is also compatible with pre-existing loop-level multithreading directives so that the code will run in distributed-memory/shared-memory mode on SMP clusters.

Michalakes, J.

1999-08-23

133

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

134

Acetate biodegradation by anaerobic microorganisms at high pH and high calcium concentration.  

PubMed

Acetate biodegradation at a high pH and a high calcium concentration was examined to clarify the effect of bacterial activity on the migration of organic (14)C compounds in cementitious repositories. Tamagawa river sediment or Teganuma pond sediment was anaerobically cultured with 5mM acetate and 10mM nitrate at pH 9.5-12 at 30C. After 20 and 90 days, the acetate concentration of the culture medium was analyzed and found to have decreased below 5mM at pH ? 11. On the other hand, it did not decrease when either sediment was incubated in the absence of nitrate. These results suggest that nitrate-reducing bacteria can biodegrade acetate under more alkaline conditions than the reported pH range in which nitrate-reducing bacteria can exhibit activity. Acetate biodegradation was also examined at a high calcium concentration. Sediments were anaerobically cultured at pH 9.5 with 5mM acetate and 10mM nitrate in solution, equilibrated with ordinary Portland cement hydrate, in which the Ca concentration was 14.6mM. No decrease in acetate concentration after incubation of the sediments was observed, nor was it lower than in the absence of cementitious composition, suggesting that kinetics of acetate biodegradation by anaerobic microorganisms is lowered by a high Ca concentration. PMID:21130545

Yoshida, Takahiro

2010-12-03

135

Design of a 20 T, 200 mm bore resistive magnet  

SciTech Connect

A 20 tesla, three coil, 200 mm bore, 20 MW resistive magnet is being designed at the National High Magnetic Field Laboratory in Tallahassee, FL., USA, in cooperation with the High Magnetic Field Laboratory of Grenoble, France. The outer two coils are axially-cooled and are connected electrically in series producing a central field of 11.27 T in a 365 mm warm bore while consuming 13.5 MW of power. The 6.5 MW inner coil (insert) is a poly-Bitter design with two sub-coils connected electrically in parallel and they together are connected in series to the two outer coils. The field of the inner coil is 8.78 T resulting in a 20 T total field in a 200 mm warm bore. All four coils are made of hard copper.

Gao, B.J.; Bird, M.D.; Bole, S.; Eyssa, Y.M.; Schneider-Muntau, H.J. [National High Magnetic Field Lab., Tallahassee, FL (United States)

1996-07-01

136

QM/MM X-ray Refinement of Zinc Metalloenzymes  

PubMed Central

Zinc metalloenzymes play an important role in biology. However, due to the limitation of molecular force field energy restraints used in X-ray refinement at medium or low resolutions, the precise geometry of the zinc coordination environment can be difficult to distinguish from ambiguous electron density maps. Due to the difficulties involved in defining accurate force fields for metal ions, the QM/MM (Quantum-Mechanical /Molecular-Mechanical) method provides an attractive and more general alternative for the study and refinement of metalloprotein active sites. Herein we present three examples that indicate that QM/MM based refinement yields a superior description of the crystal structure based on R and Rfree values and on the inspection of the zinc coordination environment. It is concluded that QM/MM refinement is a useful general tool for the improvement of the metal coordination sphere in metalloenzyme active sites.

Li, Xue; Hayik, Seth A.; Merz, Kenneth M.

2010-01-01

137

Peacemaker: Fracture assessment of a 155mm cannon barrel  

SciTech Connect

A single crack 30 mm or deeper which is 75 mm long is sufficient to fracture a typical 155 mm cannon barrel with a pressure at or above two-thirds (206 MPa -- 30 ksi) of the maximum operating pressure (310 MPa -- 45 ksi). Longer and deeper flaws reduce the critical pressure required to initiate fracture. For the monolithic barrel design considered in this work, the postulated 30 mm deep by 75 mm long crack should propagate through the entire wall and, depending upon the new ``fractured`` geometry, may propagate axially down the cannon barrel. Numerical analyses conducted with straight through-thickness crack fronts propagated axially at pressures below the maximum operating pressure while those with curved crack fronts required pressures in excess of the working pressures to extend axially. (Experiments on actual 155 mm barrels with flaws similar to the one generated by the tested shape charge show appreciable axial crack extension at approximately equivalent pressures.) In either case, a through-thickness ``hole`` will be formed in the barrel`s side and a reduction in firing pressure should result. Finally, debris deposited within the barrel can greatly assist the fracture process, especially at lower operating pressures. Overall, a single deep and long interior crack appears the most effective way to fracture a cannon barrel. Unless clustered very closely together, multiple ``shallow`` cracks require higher pressures to fracture than does a single deep crack. Flaws introduced on the barrel`s exterior are less efficient since no crack-face pressures exist and the overall stresses on the barrel`s exterior are much lower than on its interior. Thus, very deep exterior cracks would be required to fail the barrel from internal pressure.

Zywicz, E.

1993-10-07

138

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

139

Azaspiracids modulate intracellular pH levels in human lymphocytes.  

PubMed

The azaspiracids (AZAs) are a group of marine toxins implicated in several intoxications whose mechanism of action is unknown. These phycotoxins include the five compounds shown in : AZA-1 (1), AZA-2 (2), AZA-3 (3), AZA-4 (4), and AZA-5 (5). The aim of this work was to study the effects of the five naturally occurring azaspiracids (AZA-1 to -5, Fig. 1) and four synthetic analogues (6-9, Fig. 2) on intracellular pH, and the influence of Ca2+ upon this effect. The AZAs (1-5) were found to modulate cytosolic Ca2+ levels in human lymphocytes, while some of them, but not all, had effects on the intracellular pH. AZA-1 (1) and AZA-2 (2) did not modify intracellular pH in a Ca2+-containing or a Ca2+-free medium. AZA-3 (3) increased intracellular pH by 0.16 units in the presence of extracellular Ca2+, an effect that was blocked when a 1 mM solution of Ni2+ was added. In a Ca2+-free medium, the increase in pH induced by AZA-3 (3) was reduced to 0.08 pH units. AZA-4 (4) inhibited the basal pH increase even in the presence of a 1 mM solution of Ni2+. In a Ca2+-free medium, the inhibition caused by AZA-4 (4) was small, but when Ca2+ was added back to the medium, the pH basal increase was again significantly inhibited. The alkalinization was also inhibited when AZA-4 (4) was added simultaneously, 10 min before or 10 min after thapsigargin (Tg), and also when the Ca2+-influx induced by Tg was inhibited by Ni2+. AZA-5 (5), on the other hand, did not modulate the intracellular pH profile in either a Ca2+-containing or a Ca2+-free medium. Finally, we investigated four synthetic analogues (6-9, Fig. 2) whose structures were based on the four originally proposed structures of azaspiracid-1, with an opened E-ring. Compound 6 induced a small cytosolic Ca2+ increase, but did not modify intracellular pH in saline solution. In a Ca2+-free medium, compound 6 blocked the pH fall when Ca2+ was added back to the medium. Compound 7 also did not modify intracellular pH in saline solutions, however it significantly blocked basal pH increases in a Ca2+-free medium. Compound 8 did not alter intracellular pH, however compound 9 induced a small acidification when Ca2+ was present in the extracellular medium. These results point to a structure-activity relationship in AZAs pH effect that affects the modulation and the coupling of intracellular pH and Ca2+. PMID:16793022

Alfonso, Amparo; Vieytes, Mercedes R; Ofuji, Katsuya; Satake, Masayuki; Nicolaou, K C; Frederick, Michael O; Botana, L M

2006-06-12

140

Challenges and current status in 300 mm rapid thermal processing  

Microsoft Academic Search

Rapid Thermal Processing (RTP) will be indispensable to meet the process requirements of future device and integrated circuit (IC) generations. The paper reviews several approaches to manage the challenges of single-wafer 300 mm heat treatment, including the most important issues in RTP system technology: temperature measurement and accuracy, fast ramp capability, process repeatability, ultra-shallow junction formation and process uniformity for

M Glck; W Lerch; D Lffelmacher; M Hauf; U Kreiser

1999-01-01

141

Metrology of 300 mm silicon wafers: Challenges and results  

Microsoft Academic Search

Challenging requirements have to be met by metrology tools for 300 mm wafers and technology generations <=0.25 mum in near future. Measurement equipment for some specific wafer parameters presently operates already at its limits and will not be able to meet the future requirements. New tools therefore were or are currently developed. The future requirements are outlined and examples for

P. Wagner

1998-01-01

142

Investigation of External Burning Propulsion for the 75mm Projectile.  

National Technical Information Service (NTIS)

Twenty external burning combustion tests were conducted with a 75mm half-model using the exhausts from fuel-rich solid propellants as the fuels. Test conditions simulated Mach 2.5 and Mach 2.0 flight at both sea level and an altitude of 15,000 ft. Base pr...

D. E. Shelor H. L. Fein

1973-01-01

143

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

Barbier, Pat

2003-01-01

144

Description of a new 63-mm diameter gas gun facility  

Microsoft Academic Search

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

S. A. Sheffield; D. W. Dugan

1985-01-01

145

Heterogeneous action of mm waves on the plant cells  

Microsoft Academic Search

Electromagnetic radiation of the radiofrequency waveband is the new antropogenic factor of the environment and research into its influence on the living organisms is of great interest. The radioprotective action of mm waves on plant cells, the embryo meristem of Hordeum L., Triticale-wittmarc, Secale L. and other sprouting seeds has been investigated. In compliance with literature data and the authors'

N. G. Shestopalova; T. I. Baeva; L. V. Vinokurova; L. N. Golovina; T. A. Dolgova; O. V. Orlova

2001-01-01

146

Esna 250MM Tri-Colored Directional Light.  

National Technical Information Service (NTIS)

The report considers the ESNA tri-colored cover on a 250mm lantern as a possible solution to meet requirements for a single station range light. The main consideration is the ability of the plastic cover to present clearly defined colored sectors to movin...

L. R. Lomer

1967-01-01

147

The New Chroma Signal Recording System for 8MM Video  

Microsoft Academic Search

The 8 MM Video standard was finalized by the Working Group composed of many companies in the world in March, 1983. The new chroma signal recording system of the 8 MS, Video standard to which we especially contributed and the new circuits to realize this system are described.

Akira Shibata; Tomomitsu Kuroyanagi; Noboru Kojima; Yoshizumi Watatani

1984-01-01

148

Development and Documentation of 16mm Microfilm Container Standards.  

National Technical Information Service (NTIS)

The report describes a project with the purpose of achieving standardization of a 16MM microfilm container and possibly the feeding feature of the film to the reader mechanism. It was also required by the Assistant Secretary of Defense that consideration ...

H. A. Barton

1974-01-01

149

Degtyarev (DT) 7-62mm Tank Machine Gun.  

National Technical Information Service (NTIS)

The 7.62mm tank-mounted Degtyarev machine gun (DT) was first used in the 1920's on Red Army tanks. Invented by V. A. Degtyarev, it was later modified by his collaborator, Soviet designed G. S. Shpagin, to accomodate a ball mounting for tank use. It's weig...

A. Blagonravov I. Chistyakov S. Simonov

1974-01-01

150

66 MM Non-Lethal Grenade: Human Effects Review.  

National Technical Information Service (NTIS)

The purpose of this report is to assess the target effectiveness and the risks of severe (unacceptable) injury to those individuals who are impacted by the 66mm Non-Lethal Grenades (NLG) submunitions or projectiles (specifically the XM99 and the XM98) fro...

D. L. Gonzalez R. Constable T. Dayton J. Wilder B. J. Klauenberg

2003-01-01

151

MM-Wave AlGaN/GaN HFET's.  

National Technical Information Service (NTIS)

AIGaN/GaN HFET's demonstrate considerable promise for advanced RF power sources for communications and radar systems. Experimental HFET devices have produced RF output power on the order of 10-12 W/mm of gate periphery at frequencies up to X-band. However...

R. J. Trew

2003-01-01

152

26. Photocopy of 35 mm. color slide (City of New ...  

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

26. Photocopy of 35 mm. color slide (City of New York Department of Ports, International Trade, and Commerce), May 1985, Norman Berger AERIAL VIEW NORTHEAST OF PIERS 95, 96, AND 97 - West 55th Street & West 56th Street Piers, Hudson River at West Fifty-fifth & West Fifty-sixth Streets, Manhattan, New York, New York County, NY

153

Advisory List of Instructional Media--16MM Films.  

ERIC Educational Resources Information Center

|These two advisory lists include information on 16mm films appropriate for the K-12 instructional program. In both bibliographies films are listed in the following categories: communication skills; guidance; health, physical education, safety, and sports; science; and social studies. The list for the 1982-1983 school year also includes categories

North Carolina State Dept. of Public Instruction, Raleigh. Div. of Educational Media.

154

M\\/M\\/1 Queueing systems with inventory  

Microsoft Academic Search

We derive stationary distributions of joint queue length and inventory processes in explicit product form for various M\\/M\\/1-systems with inventory under continuous re- view and different inventory management policies, and with lost sales. Demand is Poisson, service times and lead times are exponentially distributed. These distributions are used to calculate performance measures of the respective systems. In case of infinite

Maike Schwarz; Cornelia Sauer; Hans Daduna; Rafal Kulik; Ryszard Szekli

2006-01-01

155

Quiet Zone characterisation at mm-wave frequencies in CATR's  

Microsoft Academic Search

A comparison is made between the two standard methods to characterise the quiet zone in a CATR and the applicability to mm-wave frequencies. The aspects considered are positioner accuracy requirements, dynamic range and measurement times. Typical numbers are given for the ESTEC ranges as representative examples.

Maurice Paquay; L. S. Drioli; L. Rolo; X. Allart; E. Saenz

2009-01-01

156

Analysis of Wear Data for the 155mm XM198.  

National Technical Information Service (NTIS)

This test attempts to determine which characteristics of tube or projectile cause or influence muzzle wear, particularly for the 155mm XM198 howitzer family of components (XM199 cannon, XM549 projectile, XM123 propelling charge). The test was limited to a...

R. G. Hasenbein

1975-01-01

157

Variations in Manufacturing Processes 155 mm Combustible Cartridge Case.  

National Technical Information Service (NTIS)

The work covered by this report consisted of the manufacture of molded 155 mm combustible casings, 30 inch (76.2 cm) P/N 9342960 with three different resins (30 each with Marbon 1600, Dow Latex 241, and Duralok); an investigation of the spiral wrapping pa...

D. C. Simpson S. Westley R. Moreira

1983-01-01

158

RF and mm-Wave Photonics at Sandia National Laboratories  

SciTech Connect

RF and mm-wave photonic devices and circuits have been developed at Sandia National Laboratories for applications ranging from RF optical data links to optical generation of mm-wave frequencies. This talk will explore recent high-speed photonics technology developments at Sandia including: (1) A monolithic optical integrated circuit for all-optical generation of mm-waves. Using integrated mode-locked diode lasers, amplifiers, and detectors, frequencies between 30 GHz and 90 GHz are generated by a single monolithic (Al,Ga)As optical circuit less than 2mm in its largest dimension. (2) Development of polarization-maintaining, low-insertion-loss, low v-pi, Mach-Zehnder interferometer (MZI) modulators with DC-to-potentially-K-band modulation bandwidth. New low-loss polarization-maintaining waveguide designs using binary alloys have been shown to reduce polarization crosstalk in undoped (Al,Ga)As waveguides, yielding high extinction ratio (>40dB) and low on-chip loss (<6dB) in Mach-Zehnder interferometers. RF drive voltage is reduced through use of 45rnrn-active length devices with modulator sensitivity, v-pi, less than 3V.

Vawter, G.A.; Sullivan, C.

1999-07-08

159

Identification of Materials from 60-mm Mortar Obturators.  

National Technical Information Service (NTIS)

Two plastic obturators for the 60-mm mortar were submitted for physical and chemical analysis. One of the obturators was from current U.S. Army stock while the other was from a contractor which had failed by misfire during field tests. The analysis reveal...

A. F. Tatyrek

1988-01-01

160

Guide to Free-Loan Sports Films (16mm).  

ERIC Educational Resources Information Center

This catalog provides information on free 16 mm films dealing with a wide variety of individual and team sports, such as football, golf, water sports, snow sports, racing, and baseball, as well as on general sports competition and safety. Unless otherwise noted, the films are in color and with sound. Titles are listed alphabetically under their

1974

161

Development of 4.75mm Superpave Mixes.  

National Technical Information Service (NTIS)

Until recently, the Superpave asphalt mix design specification did not include the 4.75mm nominal maximum aggregate size (NMAS). Such mixes have the potential to create a smooth riding surface, extend pavement life, improve ride quality, improve safety ch...

S. G. Williams

2006-01-01

162

Development of a 30mm Frangible Projectile Crimper.  

National Technical Information Service (NTIS)

The hydraulic crimping method used to assemble GAU-8/A (30mm) ammunition has been found unsuited for use with two projectile designs under development by AFATL. One of these, a plastic jacketed washer stack frangible target practice projectile, was chosen...

R. E. Rayle

1977-01-01

163

GAU-8 30mm Gun Barrel Rifling Development.  

National Technical Information Service (NTIS)

A 9-month program was conducted to develop improved 30mm GAU-8 rifling and deliver test barrels to the Air Force which incorporated the new rifling designs. Gain twist rifling was designed. Two rifling groove configurations, modified conventional and sawt...

D. P. Haas R. A. Harlow

1977-01-01

164

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

165

Comparative image quality of 105 mm and conventional spot films.  

PubMed

The image qualities of 105 mm film (Cronex MRF-21) and a conventional screen-film (Hi-Plus/Cronex 4) were compared for gastrointestinal studies, a high-contrast-resolution procedure, using a General Electric MPX 100/Fluoricon 300 x-ray system. The high contrast resolution was determined at a location approximating the midplane of an average-sized patient (20 cm). Films were made for each image-intensifier mode (9, 6, and 4.5 inch [22.9, 15.2, and 11.4 cm]) and compared with the conventional screen-film for contrast transfer (modulation-transfer function) and maximum cutoff frequency. The effects of unsharpness caused by patient motion were included in the analysis. The patient entrance exposure was measured for each technique. In the absence of patient motion, the cutoff frequencies for the spot films in the 9, 6, and 4.5 inch (22.9, 15.2, and 11.4 cm) modes were 2.1, 2.3, and 2.4 line pairs/mm, respectively. The cutoff frequency for the conventional spot-film was 2.0 line pairs/mm. The modulation-transfer functions for the 105 mm films in the 9, 6, and 4.5 inch (22.9, 15.2, and 11.4 cm) modes were found to be equal to or superior to those of the conventional screen-film for all degrees of patient motion. The 6 inch (15.2 cm), 105 mm films were found to have the best overall performance. These results were achieved with a reduction in radiation dose of 55%. PMID:6607654

Weaver, K E; Trembley, C A; Lewicki, A M

1984-03-01

166

Expansion of Bound-State Energies in Powers of m/M and (1-m/M)  

SciTech Connect

Elaborating on a previous letter [1], we use a new approach to compute energy levels of a nonrelativistic bound-state of two constituents, with masses m and M, by systematic expansions--one in powers of m/M and another in powers of (1-m/M). Technical aspects of the calculations are described in detail. Theoretical predictions are given for {Omicron}({alpha}(Z{alpha}){sup 5}) radiative recoil and {Omicron}((Z{alpha}){sup 6}) pure recoil corrections to the average energy shift and hyperfine splitting relevant for hydrogen, muonic hydrogen, and muonium.

Melnikov, Kirill

2002-01-30

167

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

168

MM/PBSA analysis of molecular dynamics simulations of bovine beta-lactoglobulin: free energy gradients in conformational transitions?  

PubMed

The pH-driven opening and closure of beta-lactoglobulin EF loop, acting as a lid and closing the internal cavity of the protein, has been studied by molecular dynamics (MD) simulations and free energy calculations based on molecular mechanics/Poisson-Boltzmann (PB) solvent-accessible surface area (MM/PBSA) methodology. The forms above and below the transition pH differ presumably only in the protonation state of residue Glu89. MM/PBSA calculations are able to reproduce qualitatively the thermodynamics of the transition. The analysis of MD simulations using a combination of MM/PBSA methodology and the colony energy approach is able to highlight the driving forces implied in the transition. The analysis suggests that global rearrangements take place before the equilibrium local conformation is reached. This conclusion may bear general relevance to conformational transitions in all lipocalins and proteins in general. PMID:15690343

Fogolari, Federico; Moroni, Elisabetta; Wojciechowski, Marcin; Baginski, Maciej; Ragona, Laura; Molinari, Henriette

2005-04-01

169

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

...Naphthas 0.1222 84.76 0.3798 Lubricants 0.1428 85.80 0.4492 Waxes...products blended with some portion of biomass-based fuel, the carbon share in Table MM-1...this subpart represents only the petroleum-based components. 2 Products that are...

2013-07-01

170

Biologiska Effekter av mm-Vagor pa Mus (Biological Effects of mm-Waves in the Mouse).  

National Technical Information Service (NTIS)

In order to study the effects of mm-waves on respiration, rectal temperature and an acoustic reaction on mice they were irradiated with a power intensity of about 10 mW/sq. cm. and a frequency of 35,0 and 94,3 GHz. The absorbed irradiation was converted i...

C. O. Criborn C. Henriksson L. D. Wernlund

1985-01-01

171

Simulation results on a resistive plate chamber for a bakelite thickness of 1 mm up to 3 mm  

SciTech Connect

The performance of bakelite electrodes with thicknesses of 1, 2, and 3 mm in a double-gap resistive plate chamber (RPC) have been tested by GEANT-based Monte Carlo simulation. Results show that the thickness of bakelite plays an important role in detecting particle signals. For checking the efficiency of these RPCs, gamma particles in the range 0.01-100 MeV have been simulated through different bakelite setups. For an isotropic gamma source, a sensitivity s{sub {gamma}}<3.5x10{sup -2} at <100 MeV by a 1 mm bakelite double-gap RPC has been observed. For the same gamma source with a 2 mm bakelite RPC, a sensitivity s{sub {gamma}}<4.0x10{sup -2} at <100 MeV has been measured, whereas for 3 mm bakelite RPC, sensitivity results were s{sub {gamma}}<4.44x10{sup -2} at <100 MeV. Similar characteristics of bakelite electrodes have been observed for a parallel gamma source configuration.

Rhee, J.T.; Jamil, M. [Institute for Advanced Physics, Konkuk University, Seoul 143-701 (Korea, Republic of)

2005-07-15

172

Perforation of 12 mm thick steel plates by 20 mm diameter projectiles with flat, hemispherical and conical noses  

Microsoft Academic Search

Projectiles with three different nose shapes (blunt, hemispherical and conical) have been used in gas gun experiments to penetrate 12mm thick Weldox 460E steel plates. Based on the experimental results, the residual velocity curves of the target material were constructed and compared. It was found that the nose shape of the projectile significantly affected both the energy absorption mechanism and

T Brvik; M Langseth; O. S Hopperstad; K. A Malo

2002-01-01

173

Making pH Tangible.  

ERIC Educational Resources Information Center

|Presents a laboratory exercise in which students test the pH of different substances, study the effect of a buffer on acidic solutions by comparing the behavior of buffered and unbuffered solutions upon the addition of acid, and compare common over-the-counter antacid remedies. (MKR)|

McIntosh, Elizabeth; Moss, Robert

1995-01-01

174

Six-mm, plane-wave shock driver  

SciTech Connect

A 6-mm-diameter, plane-wave shock generation system has been developed and characterized as a laboratory bench driver for small scale experiments. The driver is based on an exploding-foil-driven slapper used either directly or to initiate an HE pellet. The slapper is driven by a low-inductance fireset with burst currents on the order of 30 kA and burst times of about 250ns, with a time-to-burst jitter under 10ns. Both the slapper impact and the detonation breakout of the pellet have been measured to be flat to within 10ns over a 6-mm diameter. Fabry-Perot velocimetry of impacts with LiF crystals were used to characterize shock pressures and durations. Attenuator plates and flyers driven by the HE were also measured, which provided a variety of available pulse shapes and data for modeling efforts.

Frank, A.M.; Chau, H.H.

1993-06-14

175

Design of 3 mm Band Hopping Frequency Synthesizer  

NASA Astrophysics Data System (ADS)

With the combination of the technique of PLL, DDS and multiplier, a 3 mm band hopping frequency synthesizer with high frequency stability and low phase noise has been presented, which is characterized by nice performances. The design includes an X-band hopping frequency source, which is the LO for millimeter-wave harmonic mixing. Once the interim frequency being locked by the phase-locked loop, the corresponding 3 mm hopping frequency would be locked. Measurement result shows that the output frequency is 93.2493.748 GHz, the bandwidth is 508 MHz, the stepping frequency is 4 MHz, and the phase noise is about -82dBc/Hz at 10 kHz offset.

Ma, Haihong; Tang, Xiaohong

2008-07-01

176

The AzTEC mm-wavelength camera  

Microsoft Academic Search

AzTEC is a mm-wavelength bolometric camera utilizing 144 silicon nitride micromesh detectors. Here, we describe the AzTEC instrument architecture and its use as an astronomical instrument. We report on several performance metrics measured during a three-month observing campaign at the James Clerk Maxwell Telescope and conclude with our plans for AzTEC as a facility instrument on the Large Millimetre Telescope.

G. W. Wilson; J. E. Austermann; T. A. Perera; K. S. Scott; P. A. R. Ade; J. J. Bock; J. Glenn; S. R. Golwala; S. Kim; Y. Kang; D. Lydon; P. D. Mauskopf; C. R. Predmore; C. M. Roberts; K. Souccar; M. S. Yun

2008-01-01

177

The LLNL 150-mm equation-of-state gun system  

Microsoft Academic Search

Lawrence Livermore National Laboratory is currently designing a large gun system for expanded studies of a wide range of materials, including samples of high explosives weighing up to 10 kg. In its initial configuration, the system will have a 150-mm bore, 20-m-long, single-stage gun that can fire a 10-kg projectile at velocities of 2.2 km\\/s. Future plans include conversion either

F. Rienecker; C. Honodel; R. Waldron; E. Moor; S. Perfect; R. Bast

1987-01-01

178

Six-mm, plane-wave shock driver  

Microsoft Academic Search

A 6-mm-diameter, plane-wave shock generation system has been developed and characterized as a laboratory bench driver for small scale experiments. The driver is based on an exploding-foil-driven slapper used either directly or to initiate an HE pellet. The slapper is driven by a low-inductance fireset with burst currents on the order of 30 kA and burst times of about 250ns,

A. M. Frank; H. H. Chau

1993-01-01

179

Six-mm, plane-wave shock driver  

Microsoft Academic Search

A 6-mm-diameter, plane-wave shock generation system has been developed and characterized as a laboratory bench driver for small scale experiments. The driver is based on an exploding-foil-driven slapper used either directly or to initiate an HE pellet. The slapper is driven by a low-inductance fireset with burst currents on the order of 30 kA and burst times of about 250

Alan M. Frank; Henry H. Chau

1994-01-01

180

2000-fps digital imager for replacing 16-mm film cameras  

NASA Astrophysics Data System (ADS)

For many years 16 mm film cameras have been used in severe environments. These film cameras are used on Hy-G automotive sleds, airborne weapon testing, range tracking, and other hazardous environments. The companies and government agencies using these cameras are in need of replacing them with a more cost-effective solution. Film-based cameras still produce the best resolving capability. However, film development time, chemical disposal, non-optimal lighting conditions, recurring media cost, and faster digital analysis are factors influencing the desire for a 16 mm film camera replacement. This paper will describe a new imager from Kodak that has been designed to replace 16 mm high-speed film cameras. Also included is a detailed configuration, operational scenario, and cost analysis of Kodak's imager for airborne applications. The KODAK EKTAPRO HG Imager, Model 2000 is a high-resolution color or monochrome CCD Camera especially designed for replacement of rugged high-speed film cameras. The HG Imager is a self-contained camera. It features a high-resolution [512 X 384], light-sensitive CCD sensor with an electronic shutter. This shutter provides blooming protection that prevents 'smearing' of bright light sources, e.g., camera looking into a bright sun reflection. The HG Imager is a very rugged camera packaged in a highly integrated housing. This imager operates from +22 to 42 VDC. The HG Imager has a similar interface and form factor as that of high-speed film cameras, e.g., Photosonics 1B. However, the HG also has the digital interfaces such as 100-Base-T Ethernet and RS-485 that enable control and image transfer. The HG Imager is designed to replace 16 mm film cameras that support rugged testing applications.

Balch, Kris S.

1999-06-01

181

Metal evaporated tape for high band 8 mm video system  

Microsoft Academic Search

The authors have developed a metal evaporated (ME) tape for use with the high-band 8-mm video system. Compared to conventional metal particle tape, the ME tape has significantly improved electromagnetic characteristics, with a video output of +5 dB and a video carrier-to-noise ratio of +5 dB. Its overall reliability equals that of conventional coated tape. The evaporation process is described,

Kazunobu Chiba; Kenichi Sato; Yoshihito Ebine; Toshikazu Sasaki

1989-01-01

182

Planetary brightness temperature measurements at 1.4-mm wavelength  

Microsoft Academic Search

Precise relative measurements of the disk brightness temperatures of Venus, Mars, Jupiter, and Saturn have been made at a mean wavelength of 1.4 mm. The rings of Saturn contribute significantly to the observed total emission. Other results include a better understanding of the properties of the NRAO 11-m antenna near its high-frequency limit and of atmospheric degradation of observations in

J. D. G. Rather; B. L. Ulich; P. A. R. Ade

1974-01-01

183

Explore a Fine Resolution MM5 for Reservoir Temperature Forecasting  

NASA Astrophysics Data System (ADS)

TVA's three nuclear plants and some fossil plants rely on reservoir water for cooling. When weather is hot during summer, variable meteorological conditions such as wind and cloud cover often affect reservoir water and make its temperature prediction particularly challenging. A critical point is occasionally reached when a decision must be made on whether to derate a generating unit to comply with thermal discharge restrictions. The decision to derate can depend on differences of a few tenths of a degree in the water temperature prediction. Predicted reservoir temperatures for cooling of a TVA nuclear plant, for example, is produced by hydrodynamic models with input meteorological condition for the entire lake approximated by a National Weather Service Forecast Office (NWSFO) forecast issued for the closest airport to the water discharge location. One of the potential areas for improving reservoir temperature prediction is the non-homogeneous meteorological forcing over the body of water. A high resolution PSU/NCAR MM5 model was explored for improving reservoir temperature forecasting. Three summer periods representing extremely hot weather conditions were selected for MM5 simulations over the cooling water source of one TVA nuclear plant. The MM5 was configured with five concentric modeling domains. Grid resolution ranged from 27 km for the coarsest to 0.3 km for the finest modeling domain. Model results from the finest resolution domain were evaluated and analyzed with observations from a meteorological tower of the plant and reservoir temperature profiles from permanent buoys near the plant. Preliminary results indicate that the fine resolution MM5 model is capable of simulating large air temperature variations resulting from extreme weather events. The model can also simulate non-homogeneous weather conditions and produce different wind patterns across the reservoir that can affect water temperature through wind induced turbulent mixing. Detailed modeling results and analyses will be presented at the joint assembly.

Mao, Q.; Mueller, S. F.

2005-05-01

184

Potassium-dependent increases in cytosolic pH stimulate metabolism and motility of mammalian sperm.  

PubMed Central

Sperm cytosolic pH, determined by the spectral properties of intracellular carboxyfluorescein, is decreased rapidly by the diffusion and subsequent dissociation of the uncharged weak acids pyruvic, lactic, or hydroxybutyric and is increased by diffusion and subsequent intracellular protonation of the weak base NH3. Metabolic and kinetic activity increases dramatically when intracellular pH is elevated above 6.8-6.9 by addition of 50 mM NH4Cl to sperm suspended in a 120 mM NaCl medium. Respiratory stimulation is not observed upon comparable additions of 50 mM Li+ or K+ or when the pH of the medium is increased from 6.5 to 8.2. However, increases of the external pH to 7.8-8.2 in medium employing 120 mM KCl result in increased metabolic and kinetic activity, comparable to the maximal stimulation induced by the phosphodiesterase inhibitor caffeine. An increase in cytosolic pH from 6.3-6.6 to 6.8 occurs concomitant with the respiratory stimulation induced by KCl in alkaline media. No change in cytosolic pH follows addition of caffeine. Cyclic AMP-dependent protein kinase activity ratios, determined in cellular extracts, are increased by caffeine treatment but are not elevated by 120 mM KCl, by alkaline pH, or by their combination. These observations indicate that cytosolic pH plays a role in the regulation of motility and metabolism of mammalian sperm that is not mediated by cyclic AMP but that may be under control of a plasma membrane voltage-dependent proton channel. However, H+ fluxes across vesicles prepared from sperm membranes are unaffected by variation in the magnitude of the transvesicular K+ concentration gradient.

Babcock, D F; Rufo, G A; Lardy, H A

1983-01-01

185

Feasibility studies of a compact mm-wave linac FEL  

SciTech Connect

Short wavelength FELs impose stringent requirements on the quality of the electron beams. The key factor in obtaining a single-pass UV or x-ray FEL is the generation of small emittance electron beams with ultra-high brightness. The pioneering work at Los Alamos National Laboratory in the last decade has resulted in a dramatic improvement in the production of high electron beam brightness and small beam emittance using rf photocathode gun. The lower bound on the emittance of a 1-nC bunch without any emittance compensation is on the order of 3 {pi} mm-mrad. This is well within the emittance requirement being considered here. Although the original R&D work at Argonne, in collaboration with the University of Illinois at Chicago and University of Wisconsin-Madison, has produced encouraging results in the area of rf structure design, x-ray mask fabrication, and LIGA processing (Lithography, Electroforming, and Molding), the goal to prove feasibility has not yet been achieved. In this paper, we will present feasibility studies for a compact single-pass mm-linac FEL based on LIGA technology. This system will consist of a photocathode rf gun operated at 30 GHz, a 50-MeV superconducting constant gradient structure operated at 60 GHz, and a microundulator with 1-mm period.

Nassiri, A.; Kustom, R.L.; Kang, Y.W.; Song, J.

1995-12-31

186

Variations on a QM/MM approach to cluster dynamics  

NASA Astrophysics Data System (ADS)

We discuss two extensions of a hierarchical QM/MM approach developed to describe clusters embedded into a polarizable environment. The first extension consists in considering the presence of a supporting metal. More specifically we consider the structure and dynamics of Na clusters on a surface built from Ar layers grown on a metal support. We study the effect of the Ar substrate and of the metal support. We find a faint binding on the surface and the effect of the dielectric response of the metal (DRM) turns out to be negligible. Deposit of small Na clusters is crucially influenced by the mechanical hardness of the metal support and the number of Ar layers, while the DRM makes little effect. The second extension consists in using the QM/MM approach to study color centers at an MgO surface. The particular efficiency of the QM/MM approach allows to consider large system's sizes and thus test the impact of the (necessarily) finite (surface) sample. We find that our results compare favorably with ab-initio approaches as well as with available experimental results.

Dinh, P. M.; Berger, D.; Faber, B.; Reinhard, P.-G.; Suraud, E.

2012-11-01

187

Calibration of a 3.5 mm coaxial power sensor using a transfer standard with 7 mm coaxial or WR42 waveguide connectors  

Microsoft Academic Search

A calibration system of a 3.5 mm coaxial power sensor was implemented using transfer standards with 7 mm coaxial or K-band waveguide input connectors. A 7 mm-3.5 mm or WR42-3.5 mm adapter was used to form a combined transfer standard. The effective efficiency of the combined transfer standard was obtained. The 3.5 mm coaxial power sensor was calibrated using the

Tae-Weon Kang; Jeong-Hwan Kim; Jae-Yong Kwon; Jeong-Il Park; Joo-Gwang Lee

2008-01-01

188

The Intracellular pH of Clostridium paradoxum, an Anaerobic, Alkaliphilic, and Thermophilic Bacterium  

PubMed Central

When the extracellular pH was increased from 7.6 to 9.8, Clostridium paradoxum, a novel alkalithermophile, increased its pH gradient across the cell membrane ((Delta)pH, pH(infin) - pH(infout)) by as much as 1.3 U. At higher pH values (>10.0), the (Delta)pH and membrane potential ((Delta)(psi)) eventually declined, and the intracellular pH increased significantly. Growth ceased when the extracellular pH was greater than 10.2 and the intracellular pH increased to above 9.8. The membrane potential increased to 110 (plusmn) 8.6 mV at pH 9.1, but the total proton motive force ((Delta)p) declined from about 65 mV at pH 7.6 to 25 mV at pH 9.8. Between the extracellular pH of 8.0 and 10.3, the intracellular ATP concentration was around 1 mM and decreased at lower and higher pH values concomitantly with a decrease in growth rate.

Cook, G. M.; Russell, J. B.; Reichert, A.; Wiegel, J.

1996-01-01

189

The intracellular pH of Clostridium paradoxum, an anaerobic, alkaliphilic, and thermophilic bacterium  

SciTech Connect

When the extracellular pH was increased from 7.6 to 9.8, Clostridium paradoxum, a novel alkalithermophile, increased its pH gradient across the cell membrane ({delta}pH, pH{sub in} - pH{sub out}) by as much as 1.3 U. At higher pH values (>10.0), the {delta}pH and membrane potential ({delta}{psi}) eventually declined, and the intracellular pH increases significantly. Growth cased when the extracellular pH was greater than 10.2 and the intracellular pH increased to above 9.8. The membrane potential increased to 110 {+-} 8.6 mV at pH 9,1, total proton motive force ({delta}p) declined from about 65 mV at pH 7.6 to 25 mV at pH between the extracellular pH of 8.0 and 10.3, the intracellular ATP concentration was around 1mM and decreased at lower and higher pH values concomitantly with a decrease in growth rate.

Cook, G.M.; Russell, J.B. [Cornell Univ., Ithaca, NY (United States); Reichert, A.; Wiegel, J. [Univ. of Georgia, Athens, GA (United States)

1996-12-01

190

Influence of external pH and Fermentation products on Clostridium acetobutylicum intracellular pH and cellular distribution of fermentation products  

SciTech Connect

Clostridium acetobutylicum ATCC 824 cells harvested from a phosphate-limited chemostat culture maintained pH 4.5 had intracellular concentrations of acetate, butyrate, and butanol which were 13-, 7-, and 1.3-fold higher, respectively, than the corresponding extracellular concentrations. Cells from a culture grown at pH 6.45 had intracellular concentrations of acetate and butyrate which were only 2.2-fold higher than the respective external concentrations. The highest intracellular concentrations to these acids were attained at ca. pH 5.5. When cells were suspended in anaerobic citrate-phosphate suffer at pH 4.5, exogenous acetate and butyrate caused a concentration-dependent decrease in the intracellular pH, while butanol had relatively little effect until the external concentration reached 150 mM. Acetone had no effect at concentrations up to 200 mM. These data demonstrate that acetate and butyrate are concentrated within the cell under acidic conditions and thus tend to lower the intracellular pH. The high intracellular butyrate concentration presumably leads to induction of solvent production, thereby circumventing a decrease in the intracellular pH great enough to be deleterious to the cell.

Huang, L.; Forsberg, C.W.; Gibbins, L.N.

1986-06-01

191

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.; Tun, I.; Snchez-Jimnez, F. M.; Silla, E.; Ramrez, F. J.

2006-05-01

192

pH sensitivity of ammonium transport by Rhbg.  

PubMed

Rhbg is a membrane glycoprotein that is involved in NH(3)/NH(4)(+) transport. Several models have been proposed to describe Rhbg, including an electroneutral NH(4)(+)/H(+) exchanger, a uniporter, an NH(4)(+) channel, or even a gas channel. In this study, we characterized the pH sensitivity of Rhbg expressed in Xenopus oocytes. We used two-electrode voltage clamp and ion-selective microelectrodes to measure NH(4)(+)-induced [and methyl ammonium (MA(+))] currents and changes in intracellular pH (pH(i)), respectively. In oocytes expressing Rhbg, 5 mM NH(4)Cl (NH(3)/NH(4)(+)) at extracellular pH (pH(o)) of 7.5 induced an inward current, decreased pH(i), and depolarized the cell. Raising pH(o) to 8.2 significantly enhanced the NH(4)(+)-induced current and pH(i) changes, whereas decreasing bath pH to 6.5 inhibited these changes. Lowering pH(i) (decreased by butyrate) also inhibited the NH(4)(+)-induced current and pH(i) decrease. In oocytes expressing Rhbg, 5 mM methyl amine hydrochloride (MA/MA(+)), often used as an NH(4)Cl substitute, induced an inward current, a pH(i) increase (not a decrease), and depolarization of the cell. Exposing the oocyte to MA/MA(+) at alkaline bath pH (8.2) enhanced the MA(+)-induced current, whereas lowering bath pH to 6.5 inhibited the MA(+) current completely. Exposing the oocyte to MA/MA(+) at low pH(i) abolished the MA(+)-induced current and depolarization; however, pH(i) still increased. These data indicate that 1) transport of NH(4)(+) and MA/MA(+) by Rhbg is pH sensitive; 2) electrogenic NH(4)(+) and MA(+) transport are stimulated by alkaline pH(o) but inhibited by acidic pH(i) or pH(o); and 3) electroneutral transport of MA by Rhbg is likely but is less sensitive to pH changes. PMID:20810915

Nakhoul, Nazih L; Abdulnour-Nakhoul, Solange M; Schmidt, Eric; Doetjes, Rienk; Rabon, Edd; Hamm, L Lee

2010-09-01

193

Cytoplasmic pH and free Mg2+ in lymphocytes  

PubMed Central

Measurements have been made of cytoplasmic pH, (pHi) and free Mg2+ concentration, ( [Mg2+]i), in pig and mouse lymphocytes. pHi was measured in four ways: by a digitonin null-point technique; by direct measurement of the pH of freeze-thawed cell pellets; from the 31P nuclear magnetic resonance (NMR) spectrum of intracellular inorganic phosphate; and by the use of a newly synthesized, intracellularly- trappable fluorescent pH indicator. In HEPES buffered physiological saline with pH 7.4 at 37 degrees C, pHi was close to 7.0. Addition of physiological levels of HCO3- and CO2 transiently acidified the cells by approximately 0.1 U. Mitogenic concentrations of concanavalin A (Con A) had no measurable effect on pH in the first hour. [Mg2+]i was assessed in three ways: (a) from the external Mg2+ null-point at which the ionophore A23187 produced no net movement of Mg2+ or H+; (b) by Mg- sensitive electrode measurements in freeze-thawed pellets; and (c) from the 31P nuclear magnetic resonance spectrum of the gamma-phosphate of intracellular ATP. Total cell Mg2+ was approximately 12 mmol per liter cell water. The NMR data indicated [Mg2+]i greater than 0.5 mM. The null-point method gave [Mg2+]i approximately 0.9 nM. The electrode measurements gave 1.35 mM, which was thought to be an overestimate. Exposure to mitogenic doses of Con A for 1 h gave no detectable change in total or free Mg2+.

1982-01-01

194

Polyamine stress at high pH in Escherichia coli K-12  

PubMed Central

Background Polyamines such as spermine and spermidine are required for growth of Escherichia coli; they interact with nucleic acids, and they bind to ribosomes. Polyamines block porins and decrease membrane permeability, activities that may protect cells in acid. At high concentrations, however, polyamines impair growth. They impair growth more severely at high pH, probably due to their increased uptake as membrane-permeant weak bases. The role of pH is critical in understanding polyamine stress. Results The effect of polyamines was tested on survival of Escherichia coli K-12 W3110 in extreme acid or base (pH conditions outside the growth range). At pH 2, 10 mM spermine increased survival by 2-fold, and putrescine increased survival by 30%. At pH 9.8, however, E. coli survival was decreased 100-fold by 10 mM spermine, putrescine, cadaverine, or spermidine. At pH 8.5, spermine decreased the growth rate substantially, whereas little effect was seen at pH 5.5. Spermidine required ten-fold higher concentrations to impair growth. On proteomic 2-D gels, spermine and spermidine caused differential expression of 31 different proteins. During log-phase growth at pH 7.0, 1 mM spermine induced eight proteins, including PykF, GlpK, SerS, DeaD, OmpC and OmpF. Proteins repressed included acetate-inducible enzymes (YfiD, Pta, Lpd) as well as RapA (HepA), and FabB. At pH 8.5, spermine induced additional proteins: TnaA, OmpA, YrdA and NanA (YhcJ) and also repressed 17 proteins. Four of the proteins that spermine induced (GlpK, OmpA, OmpF, TnaA) and five that were repressed (Lpd, Pta, SucB, TpiA, YfiD) show similar induction or repression, respectively, in base compared to acid. Most of these base stress proteins were also regulated by spermidine, but only at ten-fold higher concentration (10 mM) at high pH (pH 8.5). Conclusion Polyamines increase survival in extreme acid, but decrease E. coli survival in extreme base. Growth inhibition by spermine and spermidine requires neutral or higher pH. At or above pH 7, spermine and spermidine regulate specific proteins, many of which are known to be regulated by base stress. High pH amplifies polyamine stress; and naturally occurring polyamines may play an important role in base stress.

Yohannes, Elizabeth; Thurber, Amy E; Wilks, Jessica C; Tate, Daniel P; Slonczewski, Joan L

2005-01-01

195

PhET Simulation: Density  

NSDL National Science Digital Library

This simulation provides a highly visual, intuitive way for students to explore how density is related to an object's mass and volume. Using a virtual water tank, users drop various objects to see what floats and what sinks. Use the mouse to submerge the object and see how much fluid it displaces. A scale is provided to measure the mass of the objects, with a density table available for view. Students can easily see why the density formula works, especially when they identify the "mystery" objects. Editor's Note: Scroll down on the page for exemplary lesson plans for grades 6-12 developed by the PhET project specifically to accompany the "Density" simulation. This item is part of a larger collection of simulations developed by the Physics Education Technology project (PhET).

2011-02-16

196

Transient blood-brain barrier passage of polar compounds at low pH.  

PubMed

The brain uptake index (BUI) of polar 14C-labeled test compounds with molecular weights (MWs) of 79-70,000 was examined using the single-pass carotid injection technique in pentobarbital-anesthetized rats. Compounds were injected in 40 mM malonate, pH 2.5, and 10 mM N-2-hydroxyethylpiperazine-N'-2-ethanesulfonic acid, pH 7.4. BUI is defined as (14C-labeled test compound/[3H]H2O in brain)/(14C-labeled test compound/[3H]H2O in injectate) x 100 at a 5-s decapitation time. Increased BUIs of compounds in pH 2.5 buffer were MW dependent with a threshold < 5,000. BUI, extraction, and permeability-surface area product (PS) were significantly greater at pH 2.5 compared with pH 7.4 (P < 0.05). Washouts of [14C]butanol and [3H]H2O at pH 2.5 and pH 7.4 were calculated. Cerebral blood flow and PS increased at low pH. Other buffers, oxalate, glycine, and lactate were used at low pH and also increased BUIs. The duration of the blood-brain barrier (BBB) opening at pH 2.5 was 60 s as estimated by penetrance of the normally excluded dye fluorescein. A plot of BUI or PS at pH 2.5 vs. (MW)1/2 suggests that transient BBB tight junction opening contributed to the passage of polar compounds at low pH. PMID:7810722

Oldendorf, W H; Stoller, B E; Tishler, T A; Williams, J L; Oldendorf, S Z

1994-12-01

197

End design of the SSC 58 mm High Gradient Quadrupole  

SciTech Connect

The ``end`` design of the High Gradient Quad. was done with consideration to the integrated field harmonics, the iron contribution, and the maximum field at the conductor. Magnetic analysis was done on the return end only, however the physical dimension of the lead end were determined as well. Using the cross-section of the windings and Cook`s program BEND, we generated the physical end windings around the return end. Placing a single wire at the center of each turn the integrated gradient was computed and iterating on the end block spacers the integrated harmonics minimized. The final geometry was then used for more, extensive calculations, such as the field at the conductor and the 3D field harmonics. For this detailed calculation we have placed a single line current at the center of each strand and included the iron contribution ({mu} = {infinity}), see Appendix C. With the termination of the iron serving as a reference, the maximum length of the inner and outer layers are 182 mm and 215 mm respectively. The magnetic length of the end was computed from the gradient function A{sub 2} and was found to be 142 mm. In reality we expect the physical length of the end to be somewhat larger, however this should have little or no effect on the magnetic length. The gradient in the straight section is 212.44 T/m at 7000 A and the integrated value of the gradient is -3.01665 E5 (G) in the end region marked by the magnetic length of the end. The respective integrated harmonics for the end 12 pole and 20 pole are -10.6658 (G/CM{sup 4}) and 0.7279 (G/cm{sup 8}) corresponding to b{sub 6} = 0.351 , b{sub 10} = -0.024 units. The above was computed from the values of A{sub 2}, A{sub 6}, and A{sub 10}.

Caspi, S.

1992-06-10

198

End design of the SSC 58 mm High Gradient Quadrupole  

SciTech Connect

The end'' design of the High Gradient Quad. was done with consideration to the integrated field harmonics, the iron contribution, and the maximum field at the conductor. Magnetic analysis was done on the return end only, however the physical dimension of the lead end were determined as well. Using the cross-section of the windings and Cook's program BEND, we generated the physical end windings around the return end. Placing a single wire at the center of each turn the integrated gradient was computed and iterating on the end block spacers the integrated harmonics minimized. The final geometry was then used for more, extensive calculations, such as the field at the conductor and the 3D field harmonics. For this detailed calculation we have placed a single line current at the center of each strand and included the iron contribution ({mu} = {infinity}), see Appendix C. With the termination of the iron serving as a reference, the maximum length of the inner and outer layers are 182 mm and 215 mm respectively. The magnetic length of the end was computed from the gradient function A{sub 2} and was found to be 142 mm. In reality we expect the physical length of the end to be somewhat larger, however this should have little or no effect on the magnetic length. The gradient in the straight section is 212.44 T/m at 7000 A and the integrated value of the gradient is -3.01665 E5 (G) in the end region marked by the magnetic length of the end. The respective integrated harmonics for the end 12 pole and 20 pole are -10.6658 (G/CM{sup 4}) and 0.7279 (G/cm{sup 8}) corresponding to b{sub 6} = 0.351 , b{sub 10} = -0.024 units. The above was computed from the values of A{sub 2}, A{sub 6}, and A{sub 10}.

Caspi, S.

1992-06-10

199

Holistic Design in mm-Wave Silicon ICs  

NASA Astrophysics Data System (ADS)

Millimeter-waves integrated circuits offer a unique opportunity for a holistic design approach encompassing RF, analog, and digital, as well as radiation and electromagnetics. The ability to deal with the complete system covering a broad range from the digital circuitry to on-chip antennas and everything in between offers unparalleled opportunities for completely new architectures and topologies, which were previously impossible due the traditional partitioning of various blocks in conventional design. This can open a plethora of new architectural and system level innovation within the integrated circuit platform. This paper reviews some of the challenges and opportunities for mm-wave ICs and presents several solutions to them.

Hajimiri, Ali

200

Planetary observations at a wavelength of 1. 32 mm  

SciTech Connect

Observations at a wavelength of 1.32 mm have been made of the Jovian planets, Ceres, the satellites Callisto and Ganymede, and the HII region DR 21. The observed brightness temperatures are presented. Those of the Jovian planets agree with the values expected from model atmosphere calculations, except that of Jupiter, which is lower than expected. Ceres and the satellites do not have atmospheres so their emission arised in their subsurface layers. The observed brightness temperatures are intermediate between those measured at infrared and centimeter wavelengths. 30 references.

Ulich, B.L.; Dickel, J.R.; De Pater, I.

1984-12-01

201

Beta backscatter gauging of PVD copper on 35-mm tape  

SciTech Connect

Mound has developed a Nondestructive Testing (NDT) system to perform automated thickness gauging of very thin (50-200 ..mu..in.) copper, vapor-deposited on 35-mm plastic tape using either beta backscatter or eddy current techniques. This report primarily discusses the backscatter development effort, which is currently capable of achieving a precision sigma of 1.2 ..mu..in. in a minimum time of approximately 30 sec. Also discussed are planned future efforts to significantly reduce measurement time. In addition, a comparison with results obtained with the eddy current technique is provided.

Dudley, W.A.; Harvey, E.D.

1983-09-30

202

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

203

A 40 mm bore quadrupole magnet for the SSC  

SciTech Connect

A 40 mm bore quadrupole magnet design, called QC'', has been made for the SSC with the following parameters: 208 T/m gradient at 6500A, 2-layer cos 2 {theta}'' winding arrangement with 30 strand cable and one spacer wedge per coil. Structural support is provided by self-supporting interlocking collars; two types of symmetrical laminations are pre-assembled into collar packs for ease of assembly. This paper will describe the design of a prototype quadrupole magnet for the SSC and preliminary tests results on 1 m models. 7 refs., 6 figs., 2 tabs.

Taylor, C.E.; Barale, P.; Caspi, S.; Dell'Orco, D.; Fritz, D.; Gilbert, W.S.; Lietzke, A.; Peters, C.; Wandesforde, A.

1990-09-01

204

Wideband mm-wave log-periodic antennas  

Microsoft Academic Search

Wideband mm-wave end-fire and planar log-periodic antennas compatible with a recently developed surface micromachined process known as PolyStratatrade are discussed in this paper. Two embodiments of each log-periodic type are developed. Specifically, an instantaneous 2-110 GHz and a dual-band 18-50 GHz and 75-110 GHz planar log-periodic antennas with integrated rectangular micro-coaxial feeds\\/impedance transformers and VSWR < 2.5:1 are designed. An

Joseph Mruk; Zhou Hongyu; Manseok Uhm; Yuya Saito; Dejan Filipovic

2009-01-01

205

Study of Man During a 56-Day Exposure to an Oxygen-Helium Atmosphere at 258 mm. Hg Total Pressure. V. Exercise Performance and Cardiovascular Response.  

National Technical Information Service (NTIS)

Four healthy Air Force crew members participated in an experiment to evaluate an oxygen-helium environment at 258 mm Hg for future manned space flights. For three weeks prior to entering the space cabin simulator, the subjects took part in a program of ph...

H. J. Zeft W. G. Robertson B. E. Welch

1966-01-01

206

New thermostable amylase from Bacillus cohnii US147 with a broad pH applicability.  

PubMed

A new thermophilic bacterial strain identified as Bacillus cohnii US147 was isolated from the southern Tunisian soil. The identification was based on physiological tests and molecular techniques related to the 16S ribosomal ribonucleic acid. The isolated strain produced amylase, which was purified. This amylase had an apparent molecular mass of 30 kDa as estimated by sodium dodecyl sulfate (SDS) polyacrylamide gel electrophoresis. Amylase US147 showed K (m) and V (max) values of 0.7 mg/ml and 2.2 U/ml, respectively, with starch as the substrate. The enzyme was active in acid and basic pH and had a maximal activity on starch at pH 9 and 70 degrees C. The enzyme was stable at pH 9 for 72 h and retained half of its activity after incubation at 70 degrees C for 150 min. A partially inhibition (15%, 25%, 23%, 20%, and 22%) was obtained with 1 mM SDS, 1 mM NaBO(3), 1 mM H(2)O(2,) 1 mM Zn(+2), and 5 mM ethylenediamine tetraacetic acid (EDTA), respectively. The amylase recovered its original activity by the addition of 10 mM Ca (2+) to the 5 mM EDTA. These properties indicated a possible use of this amylase in starch saccharification, in detergent, and in other industrial applications. PMID:18626582

Ghorbel, Raoudha Ellouz; Maktouf, Sameh; Massoud, Ezedine Ben; Bejar, Samir; Chaabouni, Semia Ellouz

2008-07-15

207

Regulation of intracellular pH in salamander retinal rods.  

PubMed Central

1. We measured intracellular pH (pHi) in rods isolated from the retina of the axolotl salamander, Ambystoma mexicanum, using the fluorescent indicator 2',7'-bis(carboxyethyl)-5(and -6)-carboxyfluorescein (BCECF). 2. The light exposures associated with data acquisition had no marked effect on pHi. There was no sharp change between the value obtained from the first exposure of dark-adapted rods and subsequent readings. Increasing the acquisition frequency from 1 to 10 min-1 either had no effect, or brought about a slow acidification, which was stopped or reversed when the low frequency was restored. 3. In nominally HCO3(-)-free solution at pH 7.5, the rods had a steady-state pHi of 7.09 +/- 0.02 (n = 46) and a buffering power (beta i) of 24 +/- 1 mM (pH unit)-1 (n = 48). The buffering power was virtually constant in the pH range 6.6-8.0. In the same range, pHi dependent linearly on perfusion pH (pHo) with regression coefficients of 0.4-0.5. 4. There were no significant differences between the inner and outer segment of intact rods as regards steady-state pHi or responses to experimental treatments. 5. Recovery from an intracellular acid load imposed by sodium propionate or an NH4Cl prepulse in nominally bicarbonate-free perfusate was completely blocked by decreasing the extracellular Na+ concentration to 7 mM, and slowed by 86% by applying 1 mM amiloride. 6. Introduction of 2% CO2-13 mM HCO3- caused an alkalinization that was often preceded by a transient acidification. Steady-state pHi was on average 0.1 pH units higher than in nominally bicarbonate-free solution. The mean acid extrusion rate, calculated on the assumption that CO2-HCO3- behaves as an open system, was 19% higher (31 +/- 2 mM h-1) than in a solution buffered only by Hepes (26 +/- 2 mM h-1). 7. In the presence of CO2-HCO3-, 100 microM 4,4'-diisothiocyanatostilbene-2,2'-disulphonic acid (DIDS) decreased the acid extrusion rate by 20% on average. Lowering the extracellular Cl-concentration to 7 mM raised pHi, but did not significantly affect the acid extrusion rate. 8. We conclude that retinal rods regulate pHi by both Na(+)-H+ exchange and mechanism(s) involving HCO3(-)-Cl- exchange. In the present conditions, the Na(+)-H+ exchanger appears as the dominant mechanism for acid extrusion.

Saarikoski, J; Ruusuvuori, E; Koskelainen, A; Donner, K

1997-01-01

208

Stress relaxation in SSC 50mm dipole coils  

SciTech Connect

We are measuring the stress relaxation of SSC 50mm outer coils with the goal of predicting how much of the coil prestress will be lost while the coils are warehoused between manufacture and cooldown. We manufacture 3 inch (76.2mm) long segments of coil with the same materials and techniques that have been used for prototype coils. We are running four simultaneous tests in an attempt to separate the contributions of the different coil materials. Test one is a completely insulated coil section where the insulation is the all polyamide system being tested at Brookhaven; test two is a wire stack insulated only with the normal Kapton overwrap; test three is a stack of bare cable; and test four is a completely insulated normal coil section. All, except for the bare cable, include the ground insulation. The insulated coil sections are carefully dried before loading and testing in order to eliminate stress changes due to varying moisture content. The temperature dependence of the stress relaxation is being studied separately. Three companion papers presented at this conference will be: (1) ``Temperature dependence of the viscoelastic properties of SSC coil insulation`` (2) ``Measurement of the elastic modulus of Kapton perpendicular to the plane of the film at room and cryogenic temperatures`` (3) ``Theoretical methods for creep and stress relaxation studies of SSC coil.``

Rogers, D.; Markley, F.

1992-04-01

209

Stress relaxation in SSC 50mm dipole coils  

SciTech Connect

We are measuring the stress relaxation of SSC 50mm outer coils with the goal of predicting how much of the coil prestress will be lost while the coils are warehoused between manufacture and cooldown. We manufacture 3 inch (76.2mm) long segments of coil with the same materials and techniques that have been used for prototype coils. We are running four simultaneous tests in an attempt to separate the contributions of the different coil materials. Test one is a completely insulated coil section where the insulation is the all polyamide system being tested at Brookhaven; test two is a wire stack insulated only with the normal Kapton overwrap; test three is a stack of bare cable; and test four is a completely insulated normal coil section. All, except for the bare cable, include the ground insulation. The insulated coil sections are carefully dried before loading and testing in order to eliminate stress changes due to varying moisture content. The temperature dependence of the stress relaxation is being studied separately. Three companion papers presented at this conference will be: (1) Temperature dependence of the viscoelastic properties of SSC coil insulation'' (2) Measurement of the elastic modulus of Kapton perpendicular to the plane of the film at room and cryogenic temperatures'' (3) Theoretical methods for creep and stress relaxation studies of SSC coil.''

Rogers, D.; Markley, F.

1992-04-01

210

Multilayer Laue Lenses with Focal Length of 10 mm  

NASA Astrophysics Data System (ADS)

Multilayer laue lenses are diffractive optics with a high potential for producing X-ray foci in the order of 10 nm or even below. Particularly for hard X-rays (E > 6 keV) these optics promise better resolution and higher efficiencies than currently available Fresnel zone plates. Magnetron sputter deposition has been used for the fabrication of multilayer laue lenses using the layer materials MoSi2 and Si. The lens design has been defined to get focal length in the order of 10 mm. One of the lenses with an aperture of about 20 ?m has been used as focusing optics in the nanoprobe beamline P06 at PETRA III. Ptychography has been applied to characterize the caustic of the focused beam and to determine the size of the X-ray focus. A spot size of about 39 nm could be obtained with a photon energy of 21 keV and a focal length of 9.9 mm.

Braun, S.; Kubec, A.; Menzel, M.; Niese, S.; Krger, P.; Seiboth, F.; Patommel, J.; Schroer, C.

2013-03-01

211

8-mm wave multichannel video and audio transmission system  

NASA Astrophysics Data System (ADS)

An experimental transmission system at 8mm-wave was built up to perform a multi-channel transmission of audio and video signals in frequency reuse, due to space separation and polarization isolation. The features of such an 8mm-wave communication systems is described in details with respect to system construction and performance. Based on carrier-to- noise ratio and the signal level available, the attenuation margin and link availability are evaluated in terms of path length and specific rainfall distribution at Hong Kong. The quality of the demodulated video and audio signals is used for the analysis of co-channel interference and multipath effects. The experiment results show that the polarization isolation is more than 18.5dB, space isolation is more than 24.1dB, and a good quality in transmission of TV programs is observed in frequency reuse situation under a uncritical condition. Finally, a simplified scheme of the application of this system in wharf container dispatching and management is proposed.

Chen, W. D.; Yung, Edward K.; Yam, Y. O.; Ding, H. Y.

1996-12-01

212

Stability of 35 mm Scanners as Used in Ophthalmologic Research  

PubMed Central

Background and Objective To assess the consistency of digitization of 35mm slides, as practiced in ophthalmologic research and estimate the impact of variation on semi-automated retinal vessel width measurements. Study Design and Methods A single retina slide was repeatedly digitized under various conditions on three scanner models. Average color levels were extracted from the resulting images, from which vessel widths were graded. The color channel level variations and possible correlation with width were analyzed. Results The Nikon 5000 scanner had average coefficients of variation (CV) of 0.4, 2.3, and 0.5 for the red, green, and blue channel levels across all runs. The p-values of the correlation between the red, green, and blue color channel levels, and the width of the large retinal arteriole, were 0.89, 0.27, and 0.58. Conclusion Our results suggest that the tested scanners digitize the 35mm slides in a reliable manner without biasing the retinal vessel measurements.

Jensen, Karl; Lee, Kristine E.; Knudtson, Michael D.; Klein, Ronald; Klein, Barbara E.K.

2009-01-01

213

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

214

Size Structure and Catch Rates of White Crappie, Black Crappie, and Bluegill in Trap Nets with 13-mm and 16-mm Mesh  

Microsoft Academic Search

We compared catch rates and size structure of white crappie Pomoxis annularis, black crappie P. nigromaculatus, and bluegill Lepomis macrochirus captured in trap nets with mesh sizes of 13 and 16 mm. We found that trap nets with 13-mm mesh caught significantly more white crappies less than 130 mm total length (TL) and bluegills less than 80 mm TL than

Jeffrey J. Jackson; Daryl L. Bauer

2000-01-01

215

The effects of picolinic acid and pH on the adsorption of Cu(II) by activated carbon fibers  

Microsoft Academic Search

The adsorption characteristics of Cu(II) on activated carbon fibers (ACFs) from simulated wastewater was investigated in the picolinic acid concentration range from 0.15 to 15 mM by varying pH from 2 to 8. When pH is below 4, the removal fraction of Cu(II) ions decreased with the decrease of pH. The removal fraction of Cu(II) ions is almost constant above

S. M Lee; S. K Ryu; C. H Jung; H. J Won; W. Z Oh

2002-01-01

216

OCTAN-1-OL/WATER PARTITION COEFFICIENTS OF P-BENZO- AND P-NAPHTHOQUINONES CORRECTED FOR PH EFFECT  

Technology Transfer Automated Retrieval System (TEKTRAN)

The effect of pH of the aqueous phase on the octan-1-ol / water partition coefficients (kow) of quinones was demontrated. The kow of a series of p-benzo- and p-naphthoquinones were determined using a mildly buffered aqueous phase (1 mM Hepes, pH 7.0) to correct for the pH effects on the lipophilicit...

217

pH of the Cytoplasm and Periplasm of Escherichia coli: Rapid Measurement by Green Fluorescent Protein Fluorimetry?  

PubMed Central

Cytoplasmic pH and periplasmic pH of Escherichia coli cells in suspension were observed with 4-s time resolution using fluorimetry of TorA-green fluorescent protein mutant 3* (TorA-GFPmut3*) and TetR-yellow fluorescent protein. Fluorescence intensity was correlated with pH using cell suspensions containing 20 mM benzoate, which equalizes the cytoplasmic pH with the external pH. When the external pH was lowered from pH 7.5 to 5.5, the cytoplasmic pH fell within 10 to 20 s to pH 5.6 to 6.5. Rapid recovery occurred until about 30 s after HCl addition and was followed by slower recovery over the next 5 min. As a control, KCl addition had no effect on fluorescence. In the presence of 5 to 10 mM acetate or benzoate, recovery from external acidification was diminished. Addition of benzoate at pH 7.0 resulted in cytoplasmic acidification with only slow recovery. Periplasmic pH was observed using TorA-GFPmut3* exported to the periplasm through the Tat system. The periplasmic location of the fusion protein was confirmed by the observation that osmotic shock greatly decreased the periplasmic fluorescence signal by loss of the protein but had no effect on the fluorescence of the cytoplasmic protein. Based on GFPmut3* fluorescence, the pH of the periplasm equaled the external pH under all conditions tested, including rapid acid shift. Benzoate addition had no effect on periplasmic pH. The cytoplasmic pH of E. coli was measured with 4-s time resolution using a method that can be applied to any strain construct, and the periplasmic pH was measured directly for the first time.

Wilks, Jessica C.; Slonczewski, Joan L.

2007-01-01

218

pH of the cytoplasm and periplasm of Escherichia coli: rapid measurement by green fluorescent protein fluorimetry.  

PubMed

Cytoplasmic pH and periplasmic pH of Escherichia coli cells in suspension were observed with 4-s time resolution using fluorimetry of TorA-green fluorescent protein mutant 3* (TorA-GFPmut3*) and TetR-yellow fluorescent protein. Fluorescence intensity was correlated with pH using cell suspensions containing 20 mM benzoate, which equalizes the cytoplasmic pH with the external pH. When the external pH was lowered from pH 7.5 to 5.5, the cytoplasmic pH fell within 10 to 20 s to pH 5.6 to 6.5. Rapid recovery occurred until about 30 s after HCl addition and was followed by slower recovery over the next 5 min. As a control, KCl addition had no effect on fluorescence. In the presence of 5 to 10 mM acetate or benzoate, recovery from external acidification was diminished. Addition of benzoate at pH 7.0 resulted in cytoplasmic acidification with only slow recovery. Periplasmic pH was observed using TorA-GFPmut3* exported to the periplasm through the Tat system. The periplasmic location of the fusion protein was confirmed by the observation that osmotic shock greatly decreased the periplasmic fluorescence signal by loss of the protein but had no effect on the fluorescence of the cytoplasmic protein. Based on GFPmut3* fluorescence, the pH of the periplasm equaled the external pH under all conditions tested, including rapid acid shift. Benzoate addition had no effect on periplasmic pH. The cytoplasmic pH of E. coli was measured with 4-s time resolution using a method that can be applied to any strain construct, and the periplasmic pH was measured directly for the first time. PMID:17545292

Wilks, Jessica C; Slonczewski, Joan L

2007-06-01

219

AMP Activation of Snake Muscle Fructose 1,6Bisphosphatase at Alkaline pH  

Microsoft Academic Search

AMP, an allosteric inhibitor at neutral pH, activates snake muscle fructose 1,6- bisphosphatase at pH 9.2. The activation is virtually unique for the snake muscle enzyme: activation was not observed for the enzymes from either human and rabbit liver or porcine kidney. The activation is Mg2+-dependent but was not observed until the concentration of Mg2+reaches 1 mM. It is known

Fu-kun Zhao; Song-qin Xu; Gen-jun Xu

1998-01-01

220

Production of Solvents by Clostridium acetobutylicum Cultures Maintained at Neutral pH  

PubMed Central

The formation of acetone and n-butanol by Clostridium acetobutylicum NCIB 8052 (ATCC 824) was monitored in batch culture at 35C in a glucose (2% [wt/vol]) minimal medium maintained throughout at either pH 5.0 or 7.0. At pH 5, good solvent production was obtained in the unsupplemented medium, although addition of acetate plus butyrate (10 mM each) caused solvent production to be initiated at a lower biomass concentration. At pH 7, although a purely acidogenic fermentation was maintained in the unsupplemented medium, low concentrations of acetone and n-butanol were produced when the glucose content of the medium was increased (to 4% [wt/vol]). Substantial solvent concentrations were, however, obtained at pH 7 in the 2% glucose medium supplemented with high concentrations of acetate plus butyrate (100 mM each, supplied as their potassium salts). Thus, C. acetobutylicum NCIB 8052, like C. beijerinckii VPI 13436, is able to produce solvents at neutral pH, although good yields are obtained only when adequately high concentrations of acetate and butyrate are supplied. Supplementation of the glucose minimal medium with propionate (20 mM) at pH 5 led to the production of some n-propanol as well as acetone and n-butanol; the final culture medium was virtually acid free. At pH 7, supplementation with propionate (150 mM) again led to the formation of n-propanol but also provoked production of some acetone and n-butanol, although in considerably smaller amounts than were obtained when the same basal medium had been fortified with acetate and butyrate at pH 7.

Holt, Robert A.; Stephens, Gillian M.; Morris, J. Gareth

1984-01-01

221

Production of solvents by Clostridium acetobutylicum cultures maintained at neutral pH  

SciTech Connect

The formation of acetone and n-butanol by Clostridium acetobutylicum NCIB 8052 (ATCC 824) was monitored in batch culture at 35 degrees C in n of acetone and n-butanol by Clostridium acetobutylicum NCIB 8052 (ATCC 824) was monitored in batch culture at 35 degrees C in a glucose (2% (wt/vol)) minimal medium maintained throughout at either pH 5.0 or 7.0. At pH 5, good solvent production was obtained in the unsupplemented medium, although addition of acetate plus butyrate (10 mM each) caused solvent production to be initiated at a lower biomass concentration. At pH 7, although a purely acidogenic fermentation was maintained in the unsupplemented medium, low concentrations of acetone and n-butanol were produced when the glucose content of the medium was increased (to 4% (wt/vol)). Substantial solvent concentrations were, however, obtained at pH 7 in the 2% glucose medium supplemented with high concentrations of acetate plus butyrate (100 mM each, supplied as their potassium salts). Thus, Clostridium acetobutylicum NCIB 8052, like Clostridium beijerinckii VPI 13436, is able to produce solvents at neutral pH, although good yields are obtained only when adequately high concentrations of acetate and butyrate are supplied. Supplementation of the glucose minimal medium, with propionate (20 mM) at pH 5 led to the production of some n-propanol as well as acetone and n-butanol; the final culture medium was virtually acid free. At pH 7, supplementation with propionate (150 mM) again led to the formation of n-propanol but also provoked production of some acetone and n-butanol, although in considerably smaller amounts than were obtained when the same basal medium had been fortified with acetate and butyrate at pH 7.

Holt, R.A.; Stephens, G.M.; Morris, J.G.

1984-12-01

222

Divalent Metals and pH Alter Raltegravir Disposition In Vitro  

PubMed Central

Raltegravir shows marked pharmacokinetic variability in patients, with gastrointestinal pH and divalent-metal binding being potential factors. We investigated raltegravir solubility, lipophilicity, pKa, and permeativity in vitro to elucidate known interactions with omeprazole, antacids, and food, all of which increase gastric pH. Solubility of raltegravir was determined at pH 1 to 8. Lipophilicity of raltegravir was determined using octanol-water partition. Raltegravir pKa was determined using UV spectroscopy. The effects of pH, metal salts, and omeprazole on the cellular permeativity of raltegravir were determined using Caco-2 monolayers. Cellular accumulation studies were used to determine the effect of interplay between pH and ABCB1 transport on raltegravir accumulation. Samples were analyzed using liquid chromatography-tandem mass spectroscopy (LC-MS/MS) or scintillation counting. Raltegravir at 10 mM was partly insoluble at pH 6.6 and below. Raltegravir lipophilicity was pH dependent and was reduced as pH was increased from 5 to 9. The pKa of raltegravir was 6.7. Raltegravir cellular permeativity was heavily influenced by changes in extracellular pH, where apical-to-basolateral permeativity was reduced 9-fold (P < 0.05) when apical pH was increased from 5 to 8.5. Raltegravir cellular permeativity was also reduced in the presence of magnesium and calcium. Omeprazole did not alter raltegravir cellular permeativity. Cellular accumulation of raltegravir was increased independently by inhibiting ABCB1 and by lowering extracellular pH from pH 8 to 5. Gastrointestinal pH and polyvalent metals can potentially alter the pharmacokinetic properties of raltegravir, and these data provide an explanation for the variability in raltegravir exposure in patients. The evaluation of how divalent-metal-containing products, such as multivitamins, that do not affect gastric pH alter raltegravir pharmacokinetics in patients is now justified.

Moss, Darren M.; Siccardi, Marco; Murphy, Matthew; Piperakis, Michael M.; Khoo, Saye H.; Back, David J.

2012-01-01

223

A cylindrical shaped micro ultrasonic motor utilizing PZT thin film (1.4 mm in diameter and 5.0 mm long stator transducer)  

Microsoft Academic Search

A cylindrical micro ultrasonic motor utilizing PZT thin film was fabricated and successfully operated on. The dimensions of a stator transducer were 1.4 mm in outer diameter, 1.2 mm in inner diameter, and 5.0 mm in length. This volume is 17% compared to our previous motor (2.4 mm in diameter and 10 mm long stator transducer).To deposit a PZT thin

Takeshi Morita; Minoru Kuribayashi Kurosawa; Toshiro Higuchi

2000-01-01

224

The effect of lead underlying water on the backscatter of X-rays of beam qualities 0.5 mm to 8 mm Al HVT  

Microsoft Academic Search

Direct measurement is made for X-ray beams with first-half-value thicknesses in the range 0.5 mm to 8 mm Al and for field sizes ranging from 15 mm diameter to 70 mm square at 100 mm SSD. The measurements were made in a water phantom using a 0.2 cm3 thimble ionization chamber. The surface dose relative to that for full backscatter

P. J. Lanzon; G. C. Sorell

1993-01-01

225

A Global Version of the MM5 Mesoscale Model  

NASA Astrophysics Data System (ADS)

Increases in computing power have led to a blurring of the roles of various atmospheric models. Global models can now be run with resolutions in the tens of kilometers. For regional models it is now also possible to expand the domain to a global size with grid sizes in the same range. To make MM5 global, we have taken two polar stereographic domains, one centered on each pole, and allowed them to interact by providing each other boundary conditions at the equator. This exchange occurs after each time-step, providing a smooth join. The expansion of MM5 to global scales enables it to run without the need for lateral boundary conditions, and so in theory it can run indefinitely given just initial conditions. The primary role of this model is for medium-range prediction and simulations of up to two weeks, a time scale that represents the limits of predictability with state-of-the-art forecast models. Another limitation to this time scale is sea-surface temperature variation that the model cannot update, except climatologically. However, running the model for five-day forecasts, as is now done regularly, illustrates some issues related to the scalability and transferability of physical parameterizations. Currently the model is run globally with a nominal grid size of 120 km, corresponding to a real grid size that varies from 128 km at the poles to 64 km at the equator due to the map-scale factor. The microphysics and convective options used were developed with finer resolution regional applications in mind, and the cloud/radiation interaction lacks any treatment of cloud fractional coverage. Nevertheless, despite the same physics being applied globally, the model behavior appears to be realistic, giving some confidence in both the scalability and transferability of the parameterizations for this application. The model physics had to be adapted for multi-day time scales of the forecasts to account for land-surface time-variability. To this end, we have developed a simple snow-cover prediction model based on surface heat and moisture budgets. MM5 Version 3 also has a full land-surface/snow/vegetation model as a more sophisticated option that can use climatologically varying vegetation fraction. The model is still deficient in gravity wave drag and its treatment of the stratosphere, which probably remain the main limits on its use for long-term general circulation simulations. Interactive vegetation, sea-ice, ocean, and /lake models would also be beneficial for climate applications.

Dudhia, J.

2001-12-01

226

Regulation of intracellular pH in rat renal inner medullary thin limbs of Henle's loop  

Microsoft Academic Search

Regulation of intracellular pH (pHi) was studied in isolated rat renal inner medullary thin limbs of Henle's loop in bicarbonate\\/phosphate-buffered medium with high pCO2, high osmolality ( mosmol\\/kg H2O; 270 mM urea; 180 mM NaCl), organic osmolytes, and a pH of 6.8 to approximate the physiological in vivo environment. The pH-sensitive fluorescent dye 2',7'-bis(2-carboxyethyl)-5,6-carboxyfluorescein (BCECF) was used to measure pHi.

Thomas L. Pannabecker; Olga H. Brokl; Yung Kyu Kim; Diane E. Abbott; William H. Dantzler

2002-01-01

227

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

228

40 mm bore Nb-Ti model dipole magnet  

SciTech Connect

Preliminary R and D has been started on magnets for a next-generation high-energy-physics accelerator, the 20 TeV Superconducting Supercollider (SSC). One design now being developed at LBL is described in this paper. The design is based on two layers of flattened Nb-Ti cable, a 40 mm ID winding with flared ends, and an operating field of 6.5 T. Experimental results are presented on several one-meter-long models tested at both He I and He II temperature. Measurement of field, residual magnetization, quench propagation velocity, and winding prestress are presented. (A 2-in-1 magnet based on this coil design is being jointly developed by LBL and Brookhaven National Laboratory, and 15 ft. long models are being constructed at BNL).

Taylor, C.; Gilbert, W.; Hassenzahl, W.; Meuser, R.; Peters, C.; Rechen, J.; Scanlan, R.

1984-09-10

229

QM/MM method for metal - organic interfaces  

SciTech Connect

Organic/inorganic interfaces are ubiquitous in organic electronics and energy materials. These interfaces often have defects, such as grain and domain boundaries, which influence their electronic properties. Fundamental studies of such extended defects, understanding of their effect on the performance of the interfaces in practical applications, and, ultimately, design of new interfaces requires theoretical modeling of their structure and properties. However, due to the large size of these systems, their accurate quantum mechanical description is often unfeasible. Here we present a QM/MM method for modeling metal/organic interfaces, which incorporates contributions from long-range electron correlation, characteristic to metals and non-bonded interactions in organic systems. This method can be used to study structurally irregular systems. We apply the method to model finite size domains of self-assembled monolayers on gold (111) surface and discuss the influence of boundary effects on the electrostatic and electronic properties of these systems.

Sushko, Maria L.; Sushko, Petr V.; Abarenkov, Igor V.; Shluger, Alexander L.

2010-07-19

230

Coupling MM5 with ISOLSM: Development, testing, and applications  

SciTech Connect

Surface water and energy fluxes are tightly coupled with CO2 exchanges between the ecosystem and atmosphere. Other surface-to-atmosphere trace-gas exchanges of interest in climate change research (e.g., N2O, CH4, C18OO, and H218O) are also strongly impacted by surface energy exchanges. Further, land-use change has large effects on the surface energy balance and therefore the exchanges of these trace gases. To investigate these issues at the regional scale we have coupled MM5 (Grell et al. 1995) with ISOLSM (Riley et al. 2002, Riley et al. 2003), a land-surface model based on LSM1 (Bonan 1995).

Riley, W.J.; Cooley, H.S.; He, Y.; Torn, M.S.

2003-06-10

231

Characterization of W CMP processes for 200-mm applications  

NASA Astrophysics Data System (ADS)

This paper presents Design Of Experiment (DOE) experimental methodology used to determine W CMP process windows for 200 mm wafers using a multi-head polish system, Cybeq Systems IP 8000 polisher. A colloidal dispersed alumina nonferric nitrate slurry and concentric grooved polyurethane pad with a closed cell foam base layer, both from Rodel, were used to examine response matrices for W CMP. Removal rates, non- uniformity and metal: oxide selectivity as a function of polish head pressure and linear velocity were examined. Removal rate trends of W and PECVD oxide, non-uniformity and selectivity as a function of head pressure indicate removal rates > 2000 angstroms/minute, non-uniformity's < 5% and selectivity of W:PE-TEOS of > 10 are achievable. The optimized process obtained through DOE methodology was applied to a device wafer. The corresponding results were a non-uniformity < 2.5%, with no observable dishing, and no observable oxide erosion.

Hansen, David A.; Luo, J. S.; Nguyen, John; Fawley, Gregory; Davis, Sue B.; Marty, Lucky F.; Yang, Fermion

1996-09-01

232

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

NASA Astrophysics Data System (ADS)

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.

233

3-D polarised simulations of space-borne passive mm/sub-mm midlatitude cirrus observations: a case study  

NASA Astrophysics Data System (ADS)

Global observations of ice clouds are needed to improve our understanding of their impact on earth's radiation balance and the water-cycle. Passive mm/sub-mm has some advantages compared to other space-borne cloud-ice remote sensing techniques. This paper presents detailed simulated observations for three such instruments, AMSU-B, CIWSIR, and EOS-MLS. The Monte-Carlo radiative transfer code, ARTS-MC, makes proper account of polarisation and uses 3-D spherical geometry. The actual field of view characteristics for each instrument are also accounted for. A 3-D midlatitude cirrus scenario is used, which is derived from Chilbolton cloud radar data and a stochastic method for generating 3-D ice water content fields. Although the main purpose of the work was to demonstrate the capability of accurately simulating observations of this type, the results suggest that cloud inhomogeneity will affect CIWSIR, and EOSMLS low tangent height observations via the beamfilling effect. Also, the results confirm that preferentially oriented ice crystals will produce significant polarisation effects.

Davis, C. P.; Evans, K. F.; Buehler, S. A.; Wu, D. L.; Pumphrey, H. C.

2006-12-01

234

3-D polarised simulations of space-borne passive mm/sub-mm midlatitude cirrus observations: a case study  

NASA Astrophysics Data System (ADS)

Global observations of ice clouds are needed to improve our understanding of their impact on earth's radiation balance and the water-cycle. Passive mm/sub-mm has some advantages compared to other space-borne cloud-ice remote sensing techniques. The physics of scattering makes forward radiative transfer modelling for such instruments challenging. This paper demonstrates the ability of a recently developed RT code, ARTS-MC, to accurately simulate observations of this type for a variety of viewing geometries corresponding to operational (AMSU-B, EOS-MLS) and proposed (CIWSIR) instruments. ARTS-MC employs an adjoint Monte-Carlo method, makes proper account of polarisation, and uses 3-D spherical geometry. The actual field of view characteristics for each instrument are also accounted for. A 3-D midlatitude cirrus scenario is used, which is derived from Chilbolton cloud radar data and a stochastic method for generating 3-D ice water content fields. These demonstration simulations clearly demonstrate the beamfilling effect, significant polarisation effects for non-spherical particles, and also a beamfilling effect with regard to polarisation.

Davis, C. P.; Evans, K. F.; Buehler, S. A.; Wu, D. L.; Pumphrey, H. C.

2007-08-01

235

Comparison of less lethal 40 mm sponge projectile and the 37 mm projectile for injury assessment on human thorax  

NASA Astrophysics Data System (ADS)

Since there is an increasing interest in avoiding human body injury in diverse situations like crowd control or peacekeeping missions, less lethal ammunition are more and more used. In this study we focus only on kinetic energy non-lethal (KENLW) projectiles. Their desired effects on human body are the temporary incapacitation through blunt trauma. There are different types of KENLW projectiles ranging from rigid to deformable projectiles. Unfortunately, the effects of such projectiles are not really well known as it is difficult to measure the force transmitted to the human body or the related deformation. Because the potential of injury excludes human living tests, tests are performed on cadavers, animals or human tissue surrogates. Besides these tests, numerical simulations are more and more used to gain more understanding, to assess or to predict the effects of this kind of projectile on human body. In this paper a comparison based on the viscous criterion between the 37 mm rigid projectile and the 40 mm sponge projectile was made.

Nsiampa, N.; Robbe, C.; Oukara, A.; Papy, A.

2012-08-01

236

Effects of ion implantation on friction and wear of stainless steels. [15-5PH  

Microsoft Academic Search

Friction and wear of 304, 15-5 PH and 440C stainless steels and of pure Fe are shown to be reduced by ion implantation of Ti and C. Mechanically polished samples were ion implanted to fluences of 2 x 10¹⁵ Ti\\/mm² (90 to 180 keV) and 2 x 10¹⁵ C\\/mm² (30 keV); the implantation profiles of the two elements extended to

L. E. Pope; F. G. Yost; D. M. Follstaedt; J. A. Knapp; S. T. Picraux

1982-01-01

237

Influence of calcium, iron and pH on phosphate availability for microbial mineralization of organic chemicals  

SciTech Connect

A study was conducted to determine some of the factors affecting the P requirement for the biodegradation of p-nitrophenol, phenol, and glucose by Pseudomonas and Corynebacterium strains. Mineralization of glucose was rapid and the Pseudomonas sp. grew extensively in solutions with 5 and 10 mM phosphate, but the rate and extent of degradation were low and the bacterial population never became abundant in media with 0.2 mM phosphate. Similar results were obtained with the Corynebacterium sp. growing in media containing p-nitrophenol or phenol and in solutions with a purified phosphate salt. The extent of growth of the Corynebacterium sp. was reduced with 2 or 10 mM phosphate in media containing high Fe concentrations. Ca at 5 mM but not 0.5 mM inhibited p-nitrophenol mineralization by the Corynebacterium sp. with phosphate concentrations from 0.2 to 5.0 mM. Phenol mineralization by the Pseudomonas sp. in medium with 0.2 mM phosphate was rapid at pH 5.2, but the bacteria had little or no activity at pH 8.0. In contrast, the activity was greater at pH 8.0 than at pH 5.2 when the culture contained 10 mM phosphate. These effects of pH were similar in media with 5 mM Ca or no added Ca. The authors conclude that the effect of P on bacterial degradation can be influenced by the pH and the concentrations of Fe and Ca.

Robertson, B.K.; Alexander, M. (Cornell Univ., Ithaca, NY (United States))

1992-01-01

238

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

Microsoft Academic Search

Change in pH regimes (pH 5.58.5), IBA (0.5mM) 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 4years of age and maintained in earthen pots. Acidic pH 5.5 administered for 4h as 5.0mM potassium\\u000a phosphate buffer significantly promoted rooting ability (%) and root number cutting?1 and

Pramod Kumar; Surendra Kumar Jharia; Shamim Akhtar Ansari

239

Microenvironments of pH in biofilms grown on dissolving silicate surfaces  

Microsoft Academic Search

Differences in pH between silicatebiofilm interfaces and bulk medium (?pH=pHinterface?pHbulk) were detectable with commercial microelectrodes in cultures grown in unbuffered medium (|?pH|=0.271.08) for an arthrobacter species, but were generally beneath detection (?pH<0.04) for a streptomyces species. Biofilm half-thicknesses developed by Arthrobacter ranged from 1.2 to 11.5 mm, and were highly variable even for replicates. In buffered medium, neither bacterium produced

Laura J. Liermann; Amy S. Barnes; Birgitta E. Kalinowski; Xiangyang Zhou; Susan L. Brantley

2000-01-01

240

Experimental characteristics of a high-gain free-electron laser amplifier operating at 8-mm and 2-mm wavelengths  

SciTech Connect

The Electron Laser Facility (ELF) at the Lawrence Livermore National Laboratory (LLNL) uses a high-current induction linac (3.5 MeV, 1000 A), in conjunction with a pulsed electromagnetic wiggler (4.0 M, 4000 G), to operate a free electron laser (FEL) that produces intense radiation in the microwave regime (2 to 8 mm). ELF is a high-gain, single-pass amplifier, using a commercial microwave source as an oscillator input (200 W-50 kW). Previous experiments at 35 GHz produced exponential gains of 40 dB/m, peak powers exceeding 1 GW, and beam-to-rf conversion efficiencies of 34%. Recent experiments at 140 GHz have demonstrated exponential gains of 22 dB/m, peak powers exceeding 50 MW, and total gains of 65 dB. In this paper, we describe the experimental results at these two frequencies and compare then with the predictions of simulation codes.

Throop, A.L.; Orzechowski, T.J.; Anderson, B.R.; Chambers, F.W.; Clark, J.C.; Fawley, W.M.; Jong, R.A.; Halbach, K.; Hopkins, D.B.; Sessler, A.M.

1987-06-08

241

GDx-MM: An imaging Mueller matrix retinal polarimeter  

NASA Astrophysics Data System (ADS)

Retinal diseases are a major cause of blindness worldwide. Although widely studied, disease mechanisms are not completely understood, and diagnostic tests may not detect disease early enough for timely intervention. The goal of this research is to contribute to research for more sensitive diagnostic tests that might use the interaction of polarized light with retinal tissue to detect subtle changes in the microstructure. This dissertation describes the GDx-MM, a scanning laser polarimeter which measures a complete 16-element Mueller matrix image of the retina. This full polarization signature may provide new comparative information on the structure of healthy and diseased retinal tissue by highlighting depolarizing structures as well as structures with varying magnitudes and orientations of retardance and diattenuation. The three major components of this dissertation are: (1) Development of methods for polarimeter optimization and error analysis; (2) Design, optimization, assembly, calibration, and validation of the GDx-MM polarimeter; and (3) Analysis of data for several human subjects. Development involved modifications to a Laser Diagnostics GDx, a commercially available scanning laser ophthalmoscope with incomplete polarization capability. Modifications included installation of polarization components, development of a data acquisition system, and implementation of algorithms to convert raw data into polarization parameter images. Optimization involved visualization of polarimeter state trajectories on the Poincare sphere and a condition number analysis of the instrument matrix. Retinal images are collected non-invasively at 20 mum resolution over a 15 visual field in four seconds. Validation of the polarimeter demonstrates a polarimetric measurement accuracy of approximately +/- 5%. Retinal polarization data was collected on normal human subjects at the University of Arizona and at Indiana University School of Optometry. Calculated polarization parameter images reveal properties of the tissue microstructure. For example, retardance images indicate nerve fiber layer thickness and orientation, and depolarization images (uniform for these normal subjects), are predicted to indicate regions of disease-related tissue disruption. This research demonstrates a method for obtaining a full polarization signature of the retina in one measurement using a polarimetrically optimized instrument, and provides a step toward the use of complete retinal imaging polarimetry in the diagnosis and monitoring of retinal disease.

Twietmeyer, Karen Marie

242

Defining and Teaching pH  

Microsoft Academic Search

The 1909 definition of pH given in most general chemistry textbooks conflicts with the modern, operationally-defined pH scale that underlies laboratory measurement and relates to activities. At an elementary level, pH and the algebra of equilibria can be simply and correctly taught, without logarithms, in terms of the latter scale.

Richard F. Burton

2007-01-01

243

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

244

Defining and Teaching pH  

NASA Astrophysics Data System (ADS)

The 1909 definition of pH given in most general chemistry textbooks conflicts with the modern, operationally-defined pH scale that underlies laboratory measurement and relates to activities. At an elementary level, pH and the algebra of equilibria can be simply and correctly taught, without logarithms, in terms of the latter scale.

Burton, Richard F.

2007-07-01

245

Interstellar isotope ratios from mm-wave molecular absorption spectra  

NASA Astrophysics Data System (ADS)

We have measured galactic lambda3 mm absorption spectra of {HCO(+) , HCN, HNC, and CS toward compact extragalactic continuum sources in order to derive the isotopic abundance ratios (12) C/(13) C, (14) N/(15) N, (16) O/(18) O, and (32) S/(34) S in local diffuse clouds. For carbon, our data confirm recent results for the local ISM: we find (12) C/(13) C = 59+/-2. For nitrogen, we find 14N/15N = 237(-21,+27) consistent with the Solar value of 270, but substantially smaller than the values inferred from HCN emission in dense clouds. For sulfur we find (32) S/(34) S ~ 19+/-8 consistent with the Solar value of 23. We also find one striking individual anomaly: toward 3C111 (B0415+379), H ^12CN/{H ^13,CN} = 170+/- 50 in one kinematic component. We attribute this to the fractionation of ^13C into ^13CO which may be so great that HCN is starved for ^13C.

Lucas, R.; Liszt, H.

1998-09-01

246

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

247

MEMS Fabricated MM-Wave Slow Wave Structure  

NASA Astrophysics Data System (ADS)

We report on the fabrication and test of a MEMS slow wave structure designed for a > 40 GHz bandwidth centered on 220 GHz operation, that slows radiation down to group velocity of 8.16 x 10^7 ms-1 where the velocity matches the speed of electrons from a 20 keV source. The slow wave device uses a 40 mm long staggered interdigitated vane structure within a waveguide [1]. Ultimately, such a device will be integrated with an electron beam to become part of a sheet beam travelling wave tube (SBTWT) amplifier. A gold coated deep reactive ion etched (DRIE) silicon test structure was fabricated to test the RF properties of the design. This MEMS structure was coupled to WR-4 waveguide in a metal fixture and the S-parameters measured using a vector network analyzer, allowing extraction of the insertion loss and signal delay as a function of frequency. A further MEMS structure with just 10 cells of the vane structure within a cavity were fabricated which allows points on the dispersion curve to be directly measured as resonances of the structure. Extraction of the dispersion curve verifies the group velocity measurement of the device. [4pt] [1] Y-M. Shin & L.R. Barnett, Appl.Phys. Lett. 2008, 92 pp. 091501.

Field, Mark; Borwick, Robert; Shin, Young-Min; Barnett, Larry; Luhmann, Neville; Kimura, Takuji; Atkinson, John

2012-02-01

248

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

249

Slip-free processing of 300 mm silicon batch wafers  

NASA Astrophysics Data System (ADS)

Under gravitational and thermal constraints of integrated-circuit (IC) process technology, 300-mm-diam silicon wafers can deform via slip dislocation generation and propagation, degrading the electrical characteristics of the leading edge device. We present a force balance model to describe the strain relaxation in large wafer diameter, which includes heat transfer effects and the upper yield point of the silicon material. The material attributes, such as oxygen content and the state of oxygen aggregation, are taken into account. The theoretical approach allows the calculation of wafer mechanics and ramp rate profiles for an arbitrary high-temperature process. Plastic deformation of silicon wafers caused by thermal stresses at high temperatures can be controlled by process design. Deformation due to gravitational forces can be prevented through appropriate equipment design. The quantitative theory proposed here provides guidance for computer simulation to configure stable slip-free wafer process flow under mechanical and thermal loads. Applications include high speed simulation of ``what if?'' experiments, and initial simulations of large scale experimental sequences. The simulator developed can also be used by IC manufacturers to determine optimum wafer throughput and cycle times in front-end device processes.

Fischer, A.; Richter, H.; Krner, W.; Kcher, P.

2000-02-01

250

SSC 50 mm dipole magnet cryostat thermal measurement results  

SciTech Connect

A prototype Superconducting Super Collider (SSC) 50 mm dipole magnet cryostat, DCA323, was instrumented at Fermilab and delivered to the SSC Laboratory for installation into the accelerator systems string test facility. In series with other magnets, the instrumented cryostat will be used to quantify and verify cryostat thermal performance with respect to design requirements. Prior to leaving Fermilab, DCA323 was subjected to magnetic testing at the Magnet Test Facility (MTF). This presented an opportunity to obtain preliminary thermal performance data under simulated operating conditions. It should be noted that measurements of overall cryostat thermal performance were not possible during the MTF measurements as the magnet test stands are designed for magnetic rather than thermal testing. They are not designed to limit heat inleak to the ends of the cryostat, which has been shown to have a significant effect on overall measured thermal performance. Nonetheless, these measurements do offer insight into the performance of several of the cryostat components and sub-systems.

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

1993-05-01

251

Parallel implementation, validation, and performance of MM5  

SciTech Connect

We describe a parallel implementation of the nonhydrostatic version of the Penn State/NCAR Mesoscale Model, MM5, that includes nesting capabilities. This version of the model can run on many different massively Parallel computers (including a cluster of workstations). The model has been implemented and run on the IBM SP and Intel multiprocessors using a columnwise decomposition that supports irregularly shaped allocations of the problem to processors. This stategy will facilitate dynamic load balancing for improved parallel efficiency and promotes a modular design that simplifies the nesting problem AU data communication for finite differencing, inter-domain exchange of data, and I/O is encapsulated within a parallel library, RSL. Hence, there are no sends or receives in the parallel model itself. The library is Generalizable to other, similar finite difference approximation codes. The code is validated by comparing the rate of growth in error between the sequential and parallel models with the error growth rate when the sequential model input is perturbed to simulate floating point rounding error. Series of runs on increasing numbers of parallel processors demonstrate that the parallel implementation is efficient and scalable to large numbers of processors.

Michalakes, J.; Canfield, T.; Nanjundiah, R.; Hammond, S. [Argonne National Lab., IL (United States); Grell, G. [National Oceanic and Atmospheric Administration, Boulder, CO (United States)

1994-12-31

252

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

253

Heterogeneous Distribution of Microbial Activity in Methanogenic Aggregates: pH and Glucose Microprofiles  

PubMed Central

Methanogenic aggregates, harvested from an upflow anaerobic sludge blanket reactor treating potato starch wastewater, were acclimatized to either glucose or a mixture of sugars and organic nitrogen compounds (i.e., diluted molasses). Both types of granules exhibited internal pH and substrate concentration gradients in mineral medium (pH 7.0, 30C) as was measured with microelectrodes. Glucose-acclimatized granules suspended in a mineral medium lacking glucose exhibited a distinct internal pH decrease of about 1 U within the granule, suggesting strong metabolism by the acidogenic bacteria. Molasses-acclimatized and aged granules suspended in mineral medium did not exhibit such a pH decrease, suggesting the importance of the metabolic state of these acidogens. The pH gradient did not occur in deactivated granules and was not observable in strongly buffered media (mineral medium containing 33 mM phosphate or reactor liquid). When glucose (0.5 to 5.0 mM) was added to the mineral medium, granules exhibited a convex pH profile. Glucose consumption was located exclusively in the outer 200 to 300 ?m of the aggregates (mean diameter = 1.5 mm). The addition of 20 mM 2-bromoethanesulfonic acid to the mineral medium indicated that the higher pH levels in the centre of the granule appeared to be related to the activity of methanogens. It is suggested that acidogenic activity occurs predominantly in the outer 200 to 300 ?m of the aggregate and methanogenic activity occurs predominantly in the center of the investigated granules. Images

Lens, Piet N. L.; De Beer, Dirk; Cronenberg, Carel C. H.; Houwen, Frans P.; Ottengraf, Simon P. P.; Verstraete, Willy H.

1993-01-01

254

Photophysical properties of MM quadruply bonded complexes supported by carboxylate ligands, MM = Mo2, MoW, or W2.  

PubMed

While chemists have extensively studied the photophysical properties of d(6), d(8), and d(10) transition metal complexes, their early transition metal counterparts have received less attention. Quadruply bonded complexes of molybdenum and tungsten supported by carboxylate ligands have intense metal-to-ligand charge transfer (MLCT) absorptions that arise from the electronic coupling of the metal-metal (MM) ? orbital with the CO(2) ?-system. This coupling may in turn be linked to an extended ?-conjugated organic functional group. The major interaction is akin to the so-called back-bonding in metal carbonyl complexes. By the appropriate selection of MM, its attendant ligands, and the organic group, this absorption can be tuned to span the visible and near IR range, from 400 to 1000 nm. Consequently, these complexes offer potential as photon harvesters for photovoltaic devices and photocatalysis. In this Account, we describe recent studies of dinuclear M(II) containing complexes, where M = Mo or W, and show that there are both parallels and disparities to the monomeric transition metal complexes. These early transition metal complexes have relatively long lived excited state singlets when compared to other transition metal complexes. They also often show unusual dual emission (fluorescence and phosphorescence), with singlet (S(1)) lifetimes that range from 1 to 20 ps, and triplet (T(1)) lifetimes from 3 ns to 200 ?s. The fluorescent S(1) states are typically (1)MLCT for both M = Mo and W. These extended singlet lifetimes are uncommon for mononuclear transition metal complexes, which typically have very short lived (1)MLCT states due to rapid femto-second intersystem crossing rates. However, the T(1) states differ. This phosphorescence is MLCT in nature when M = W, while this emission comes from the ??* state for M = Mo. Through time-resolved femtosecond infrared spectroscopy, we can detect the asymmetric stretch of the CO(2) ligand in both the singlet and triplet ??* states. Through these analytical methods, we can study how the charge distribution in the singlet and triplet excited states changes over time. In addition, we can detect delocalized or localized examples of MLCT states, which represent class III and I excited state mixed valence in the Robin and Day scheme. PMID:23145921

Chisholm, Malcolm H; Gustafson, Terry L; Turro, Claudia

2012-11-12

255

Ionic and pH effects on the osmotic properties and structure of polyelectrolyte gels  

PubMed Central

We investigate the effects of salt concentration and pH on neutralized poly(acrylic acid) (PAA) gels in near physiological salt solutions. Either adding calcium ions or decreasing the pH are found to induce reversible volume transitions but the nature of these transitions seems to be different. For example, the osmotic pressure exhibits a simple power law dependence on the concentration as the transition is approached in both systems, but the power law exponent n is substantially different in the two cases. On decreasing the pH the value of n gradually increases from 2.1 (at pH = 7) to 3.2 (at pH = 1). By contrast, n decreases with increasing calcium ion concentration from 2.1 (in 100 mM NaCl solution) to 1.6 (0.8 mM CaCl2 in 100 mM NaCl solution). In both systems, a strong increase of the small-angle neutron scattering intensity (SANS) is observed near the volume transition. The SANS results reveal that calcium ions favor the formation of linearly aligned regions in PAA gels.

Horkay, Ferenc; Basser, Peter J.

2009-01-01

256

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

257

Online PH measurement technique in seawater desalination  

NASA Astrophysics Data System (ADS)

The measurement technology of pH is essential in seawater desalination. Glass electrode is the main pH sensor in seawater desalination. Because the internal impedance of glass electrode is high and the signal of pH sensor is easy to be disturbed, a signal processing circuit with high input impedance was designed. Because of high salinity of seawater and the characteristic of glass electrode, ultrasonic cleaning technology was used to online clean pH sensor. Temperature compensation was also designed to reduce the measurement error caused by variety of environment temperature. Additionally, the potential drift of pH sensor was analyzed and an automatic calibration method was proposed. In order to online monitor the variety of pH in seawater desalination, three operating modes were designed. The three modes are online monitoring mode, ultrasonic cleaning mode and auto-calibration mode. The current pH in seawater desalination was measured and displayed in online monitoring mode. The cleaning process of pH sensor was done in ultrasonic cleaning mode. The calibration of pH sensor was finished in auto-calibration mode. The result of experiments showed that the measurement technology of pH could meet the technical requirements for desalination. The glass electrode could be promptly and online cleaned and its service life was lengthened greatly.

Wang, Haibo; Wu, Kaihua; Hu, Shaopeng

2009-11-01

258

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

PubMed

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. PMID:11537850

Hasenstein, K H; Evans, M L

1988-01-01

259

Online preconcentration of arsenic compounds by dynamic pH junction-capillary electrophoresis.  

PubMed

An online preconcentration technique by dynamic pH junction was studied to improve the detection limit for anionic arsenic compounds by CE. The main target compound is roxarsone, or 3-nitro-4-hydroxyphenylarsonic acid, which is being used as an animal feed additive. The other inorganic and organoarsenic compounds studied are the possible biotransformation products of roxarsone. The arsenic species were separated by a dynamic pH junction in a fused-silica capillary using 15 mM phosphate buffer (pH 10.6) as the BGE and 15 mM acetic acid as the sample matrix. CE with UV detection was monitored at a wavelength of 192 nm. The influence of buffer pH and concentration on dynamic pH junction were investigated. The arsenic species focusing resulted in LOD improvement by a factor of 100-800. The combined use of C18 and anion exchange SPE and dynamic pH junction to CE analysis of chicken litter and soils helps to increase the detection sensitivity. Recoveries of spiked samples ranged between 70 and 72%. PMID:17396598

Jaafar, Jafariah; Irwan, Zildawarni; Ahamad, Rahmalan; Terabe, Shigeru; Ikegami, Tohru; Tanaka, Nobuo

2007-02-01

260

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

261

Inbred maize line Ph0R8  

US Patent & Trademark Office Database

An inbred maize line, designated PH0R8, the plants and seeds of inbred maize line PH0R8, methods for producing a maize plant, either inbred or hybrid, produced by crossing the inbred maize line PH0R8 with itself or with another maize plant, and hybrid maize seeds and plants produced by crossing the inbred line PH0R8 with another maize line or plant and to methods for producing a maize plant containing in its genetic material one or more transgenes and to the transgenic maize plants produced by that method. This invention also relates to inbred maize lines derived from inbred maize line PH0R8, to methods for producing other inbred maize lines derived from inbred maize line PH0R8 and to the inbred maize lines derived by the use of those methods.

2004-04-06

262

Minireview: pH and synaptic transmission.  

PubMed

As a general rule a rise in pH increases neuronal activity, whereas it is dampened by a fall of pH. Neuronal activity per se also challenges pH homeostasis by the increase of metabolic acid equivalents. Moreover, the negative membrane potential of neurons promotes the intracellular accumulation of protons. Synaptic key players such as glutamate receptors or voltage-gated calcium channels show strong pH dependence and effects of pH gradients on synaptic processes are well known. However, the processes and mechanisms that allow controlling the pH in synaptic structures and how these mechanisms contribute to normal synaptic function are only beginning to be resolved. PMID:23669358

Sinning, Anne; Hbner, Christian A

2013-05-10

263

Spectrophotometric pH measurements of freshwater  

Microsoft Academic Search

The use of cresol red (CR) indicator for determination of freshwater pH is evaluated. Ionic strength effects and indicator pH perturbation are discussed and quantified using theoretical and empirical approaches. Spectrophotometric and potentiometric methods are directly compared by repeated analyses of a low ionic strength pH buffer. The mean and standard deviation of the two methods were 7.6180.008 (spectrophotometric) and

Craig R French; Jeffrey J Carr; Eleanor M Dougherty; Lisa A. K Eidson; Jason C Reynolds; Michael D DeGrandpre

2002-01-01

264

The pH of estuarine waters  

Microsoft Academic Search

The emf measurements for the TRIS buffer in seawater have been used to define buffer solutions that can be used to determine the pH on a free or total proton scale for estuarine waters. The pH is related to the stoichiometric dissociation constant (K*) of TRISH I-, the concentration of buffer (mTRrs) and salinity (5) by pH = pK* +

FRANK J. MILLERO

1986-01-01

265

Synthesis and activity of Helicobacter pylori urease and catalase at low pH.  

PubMed Central

BACKGROUND: Helicobacter pylori produces large amounts of urease presumably to be prepared for the rare event of a sudden acid exposure. The hypothesis that H pylori is acid sensitive and protein production is inhibited by low pH was examined. METHODS: H pylori or its soluble enzymes were incubated buffered or unbuffered at a pH ranging from 2-7 in the presence of 5 mM urea for 30 minutes. After exposure, urease and catalase activities of whole cells, supernatants, and soluble enzyme preparations were measured at pH 6.8. Newly synthesised enzyme was quantified by immunoprecipitation of [35S]-methionine labelled protein. RESULTS: Exposure to buffer below pH 4 resulted in loss of intracellular urease activity. In soluble enzyme preparations and supernatant, no urease activity was measurable after incubation at pH < 5. In contrast, catalase in whole cells, supernatant, and soluble enzyme preparations remained active after exposure to pH > or = 3. Exposure below pH 5 inhibited synthesis of total protein including nascent urease and catalase. At pH 6 or 7, urease represented 10% of total protein, catalase 1.5%. Exposure of H pylori to unbuffered HCl (pH > 2) resulted in an immediate neutralisation; urease and catalase activities and synthesis were unchanged. CONCLUSION: Low surrounding pH reduces activity of urease and synthesis of nascent urease, catalase, and presumably of most other proteins. This suggests that H pylori is not acidophilic although it tolerates short-term exposure to low pH.

Bauerfeind, P; Garner, R; Dunn, B E; Mobley, H L

1997-01-01

266

Effect of low pH on nitrogen fixation of common bean grown at various calcium and nitrate levels  

Microsoft Academic Search

The influence of low pH (4.04.5) of the medium on nodulation, nodule biomass, nodule nitrogenase activity, and ultrastructure at various concentrations of calcium (Ca) (0.127 mM and 0.508 mM) and nitrate (NO3) (0.390 mM and 1.560 mM) at different stages of development (2nd, 3rd, 6th, and 7th compound leaf) of the common bean plants was studied. The experiment was conducted

V. Vassileva; G. Milanov; G. Ignatov; B. Nikolov

1997-01-01

267

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

268

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

269

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

270

Sodium chloride reduces growth and cytosolic calcium, but does not affect cytosolic pH, in root hairs of Arabidopsis thaliana L  

Microsoft Academic Search

The effects of salinity (NaCl) stress on growth, cytoso- lic Ca2+ gradients and cytosolic pH homeostasis of root hairs of Arabidopsis thaliana are assessed here. Neither cytosolic Ca2+ nor pH at the hair apex were significantly affected by 20 min exposure of up to 90 mM NaCl or of up to 5 mM extracellular Ca2+. Exposure to increasing NaCl concentrations,

Stephen J. Halperin; Simon Gilroy; Jonathan P. Lynch

2003-01-01

271

Effect of External pH on the Internal pH of Chlorella saccharophila1  

PubMed Central

The overall internal pH of the acid-tolerant green alga, Chlorella saccharophila, was determined in the light and in the dark by the distribution of 5,5-dimethyl-2-[14C]oxazolidine-2,4-dione ([14C]DMO) or [14C]benzoic acid ([14C]BA) between the cells and the surrounding medium. [14C]DMO was used at external pH of 5.0 to 7.5 while [14C]BA was used in the range pH 3.0 to pH 5.5. Neither compound was metabolized by the algal cells and intracellular binding was minimal. The internal pH of the algae obtained with the two compounds at external pH values of 5.0 and 5.5 were in good agreement. The internal pH of C. saccharophila remained relatively constant at pH 7.3 over the external pH range of pH 5.0 to 7.5. Below pH 5.0, however, there was a gradual decrease in the internal pH to 6.4 at an external pH of 3.0. The maintenance of a constant internal pH requires energy and the downward drift of internal pH with a drop in external pH may be a mechanism to conserve energy and allow growth at acid pH.

Gehl, Katharina A.; Colman, Brian

1985-01-01

272

A QM\\/MM study of the complexes formed by aluminum and iron with serum transferrin at neutral and acidic pH  

Microsoft Academic Search

Serum transferrin (sTf) transports iron in serum and internalizes in cells via receptor mediated endocytosis. Additionally, sTf has been identified as the predominant aluminum carrier in serum. Some questions remain unclear about the exact mechanism for the metal release or whether the aluminum and iron show the same binding mode during the entire process. In the present work, simulation techniques

J. I. Mujika; X. Lopez; E. Rezabal; R. Castillo; S. Marti; V. Moliner; J. M. Ugalde

273

The PhD Student at Work.  

ERIC Educational Resources Information Center

The common patterns of work activity adopted by science students during the three years of PhD study are described, and their relationship to thesis submission is examined. The results suggest that the organization of PhD study is an important feature of success (defined in terms of submission of a thesis). (Author/MLW)

Welsh, Jennifer M.

1981-01-01

274

The PhD student at work  

Microsoft Academic Search

The most common patterns of work activity adopted by Science students during the three years of PhD study are described and their relationship to thesis submission examined. The results suggest that the organisation of PhD study, at least in Science, is an important feature of success, defined in terms of submission of a thesis.

Jennifer M. Welsh

1981-01-01

275

pH management in container media  

Microsoft Academic Search

Addition of lime to increase pH is generally required for soilless media based on acidic organic materials. Media pH may decrease over time as the result of addition of acidic fertilizers. The objectives of this research were to characterize reactions of conventional or finely ground limestone in soilless media and to compare resistance to acidification in soilless media amended with

George C. Elliott

1996-01-01

276

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.

277

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.

278

Urbanism PhD Research 2008 - 2010  

Microsoft Academic Search

To ensure the quality of the Ph.D. research the Department introduced a special procedure for periodic evaluation: after a period of nine months the potential Ph.D. candidates are asked to present their research design, theoretical framework and methodological approach to the members of the Department and to an external review, drawn up by the professors of the Department and by

F. D. Van der Hoeven; N. Brand; L. Van der Burg; O. al??kan; E. R. Tan; C.-Y. Wang; J. Zhou

2009-01-01

279

Response to the "Responsive PhD"  

ERIC Educational Resources Information Center

|In June 2005, 50 graduate school deans gathered at Princeton to address the fact that the number of new PhDs conferred each year far exceeds the number of tenure-track academic jobs on offer. Under the auspices of the Woodrow Wilson National Fellowship Foundation's Responsive PhD Project, these deans spoke passionately about how American

Huyssen, David

2007-01-01

280

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...

281

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

282

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

283

77 FR 75850 - Regulated Navigation Area; Upper Mississippi River MM 0.0 to MM 185.0; Cairo, IL to St. Louis, MO  

Federal Register 2010, 2011, 2012, 2013

...Regulated Navigation Area; Upper Mississippi River MM 0.0 to MM 185.0; Cairo...for all waters of the Upper Mississippi River between miles 0.0 and 185...water conditions on the Upper Mississippi River. Any deviation from the...

2012-12-26

284

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.

Simao, Ana Maria S.; Bolean, Mayte; Hoylaerts, Marc F.; Millan, Jose Luis; Ciancaglini, Pietro

2013-01-01

285

Rabring7 Degrades c-Myc through Complex Formation with MM-1  

PubMed Central

We have reported that a novel c-Myc-binding protein, MM-1, repressed E-box-dependent transcription and transforming activities of c-Myc and that a mutation of A157R in MM-1, which is often observed in patients with leukemia or lymphoma, abrogated all of the repressive activities of MM-1 toward c-Myc, indicating that MM-1 is a novel tumor suppressor. MM-1 also binds to the ubiquitin-proteasome system, leading to degradation of c-Myc. In this study, we identified Rabring7, a Rab7-binding and RING finger-containing protein, as an MM-1-binding protein, and we found that Rabring7 mono-ubiquitinated MM-1 in the cytoplasm without degradation of MM-1. Rabring7 was also found to bind to c-Myc and to ubiquitinate c-Myc in a threonine 58-dependent manner. When c-Myc was co-transfected with MM-1 and Rabring7, c-Myc was degraded. Furthermore, it was found that c-Myc was stabilized in MM-1-knockdown cells even when Rabring7 was transfected and that Rabring7 was bound to and co-localized with MM-1 and c-Myc after MM-1 and Rabring7 had been translocated from the cytoplasm to the nucleus. These results suggest that Rabring7 stimulates c-Myc degradation via mono-ubiquitination of MM-1.

Torii, Ayako; Tashiro, Erika; Miyazawa, Makoto; Ariga, Hiroyoshi; Iguchi-Ariga, Sanae M. M.

2012-01-01

286

Effect of media pH on nitrate uptake, dry matter production and nitrogen accumulation by corn ( Zea mays L.) seedlings grown in solution culture  

Microsoft Academic Search

Experiments were conducted (a) to identify optimum media pH for nitrate uptake by intact corn (Zed ways L. cv. XL-81) plants grown under solution culture conditions, (b) to understand the effect of media pH on growth, nitrate\\u000a uptake, water use and nitrogen accumulation. pH was maintained using carboxy cation exchange resin IRC-50. Plantswere grown in 15mM NO3-N per litre and

Raghuveer Polisetty; R. H. Hageman

1985-01-01

287

Community-specific pH response of denitrification: experiments with cells extracted from organic soils.  

PubMed

Denitrifying prokaryotes are phylogenetically and functionally diverse. Little is known about the relationship between soil denitrifier community composition and functional traits. We extracted bacterial cells from three cultivated peat soils with contrasting native pH by density gradient centrifugation and investigated their kinetics of oxygen depletion and NO2 -, NO, N(2) O and N(2) accumulation during initially hypoxic batch incubations (0.5-1 ?M O(2)) in minimal medium buffered at either pH 5.4 or 7.1 (2 mM glutamate, 2 mM NO3 -). The three communities differed strikingly in NO2 - accumulation and transient N(2) O accumulation at the two pH levels, whereas NO peak concentrations (24-53 nM) were similar across all communities and pH treatments. The results confirm that the communities represent different denitrification regulatory phenotypes, as indicated by previous denitrification bioassays with nonbuffered slurries of the same three soils. The composition of the extracted cells resembled that of the parent soils (PCR-TRFLP analyses of 16S rRNA genes, nirK, nirS and nosZ), which were found to differ profoundly in their genetic composition (Braker et al., ). Together, this suggests that direct pH response of denitrification depends on denitrifier community composition, with implications for the propensity of soils to emit N(2) O to the atmosphere. PMID:22093000

Drsch, Peter; Braker, Gesche; Bakken, Lars Reier

2011-12-13

288

Complexation between ?-cyclodextrin and PEGylated-PAMAM dendrimers at low and high pH values.  

PubMed

Poly(ethylene glycol)-grafted-poly(amido amine) (PEGylated-PAMAM) dendrimers have attracted increasing amounts of attention because of their improved stability, toxicity, and better particle drug leakage property. The complexation of ?-cyclodextrin (?-CD) with grafted PEG segments on the surface of PAMAM dendrimers was elucidated by light scattering and titration calorimetry. At pH 10, complexation between ?-CD and PEGylated-PAMAM occurred once ?-CD was titrated into the PAMAM solution. We observed for the first time a unique phenomenon at pH 2, where no binding took place until a critical ?-CD concentration (C*) of ?8.0 mM was reached. The size of the nanostructures increased from 6.7 to 57.6 nm when the ?-CD concentration was increased from 0.5 to 15 mM at pH 2. The zeta potential of PEGylated-PAMAM at pH 2 was +6.7 mV. Thus, the dendrimers possessed positive charges attributed to the protonation of primary amine groups on PAMAM chains that impart electrostatic repulsive forces to the system. The morphology of the complex is expected to be different at two different pH values (2 and 10) because the former produces a clear solution and the latter forms a turbid solution with white precipitates. PMID:21038877

Khouri, Salim; Tam, Kam C

2010-11-01

289

Microsensor analysis of oxygen and pH in the rice rhizosphere under field and laboratory conditions  

Microsoft Academic Search

O2 and pH microsensors were used to analyse the microdistribution of O2 and pH inside and outside roots of lowland rice (Oryza sativa L.). The roots of 3-week-old transplants had O2 concentrations of about 20% air saturation at the surface, but due to a high rate of O2 consumption in the rhizosphere, the oxic region only extended about 0.4?mm into

N. P. Revsbech; O. Pedersen; W. Reichardt; A. Briones

1999-01-01

290

Effect of pH on nitrogen supply, cell lysis, and solvent production in fermentations of Clostridium acetobutylicum  

Microsoft Academic Search

In batch fermentations of C. acetobutylicum, with 5 g\\/l yeast extract and 50 mM glucose, the ratio of ammonium to glucose affected solvent production when the pH was left to vary uncontrolled from 4.5 to 3.65. High solvent production was observed for a low ratio. When the pH was controlled at 4.5, only acids were produced for all ratio values.

Joseph W. Roos; Joseph K. McLaughlin; Eleftherios T. Papoutsakis

1985-01-01

291

Regulation of cellular pH in skeletal muscle fiber types, studied with sarcolemmal giant vesicles obtained from rat muscles  

Microsoft Academic Search

Sarcolemmal giant vesicles obtained from rat hindlimb muscles were used as a model for the study of pH regulation in skeletal muscle. The transport systems involved in the recovery from 40 mM lactate and pHi 6.5 were quantified from both flux measurements of the co-transported ions and counter-ions, and from measurements of the rate of the internal pH change. The

Carsten Juel

1995-01-01

292

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 2C for 5 days. CaCl2 treatment had a significant effect on firmness

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

2008-01-01

293

Noninvasive in vivo fluorescence measurement of airway-surface liquid depth, salt concentration, and pH  

PubMed Central

The concentration of salt in the thin layer of fluid at the surface of large airways, the airway-surface liquid (ASL), is believed to be of central importance in airway physiology and in the pathophysiology of cystic fibrosis. Invasive sampling methods have yielded a wide range of ASL [NaCl] from 40 to 180 mM. We have developed novel fluorescent probes and microscopy methods to measure ASL thickness, salt concentration, and pH quantitatively in cell-culture models and in the trachea in vivo. By rapid z-scanning confocal microscopy, ASL thickness was 21 4 ?m in well-differentiated cultures of bovine tracheal epithelial cells grown on porous supports at an air-liquid interface. By ratio imaging fluorescence microscopy using sodium, chloride, and pH-sensitive fluorescent indicators, ASL [Na+] was 97 5 mM, [Cl] was 118 3 mM, and pH was 6.94 0.03. In anesthetized mice in which a transparent window was created in the trachea, ASL thickness was 45 5 ?m, [Na+] was 115 4 mM, [Cl] was 140 5 mM, and pH was 6.95 0.05. Similar ASL tonicity and pH were found in cystic fibrosis (CFTR-null) mice. In freshly harvested human bronchi, ASL thickness was 55 5 ?m, [Na+] was 103 3 mM, [Cl] was 92 4 mM, and pH was 6.78 0.2. These results establish by a noninvasive approach the key properties of the ASL and provide direct evidence that the ASL is approximately isotonic and not saltier in cystic fibrosis.

Jayaraman, Sujatha; Song, Yuanlin; Vetrivel, L.; Shankar, Leena; Verkman, A.S.

2001-01-01

294

Deep x-ray lithography fabrication of mm Wave cavities at the Advanced Photon Source.  

National Technical Information Service (NTIS)

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 amplif...

J. J. Song

1998-01-01

295

Pleckstrin homology (PH) domains and phosphoinositides.  

PubMed

PH (pleckstrin homology) domains represent the 11th most common domain in the human proteome. They are best known for their ability to bind phosphoinositides with high affinity and specificity, although it is now clear that less than 10% of all PH domains share this property. Cases in which PH domains bind specific phosphoinositides with high affinity are restricted to those phosphoinositides that have a pair of adjacent phosphates in their inositol headgroup. Those that do not [PtdIns3P, PtdIns5P and PtdIns(3,5)P2] are instead recognized by distinct classes of domains including FYVE domains, PX (phox homology) domains, PHD (plant homeodomain) fingers and the recently identified PROPPINs (b-propellers that bind polyphosphoinositides). Of the 90% of PH domains that do not bind strongly and specifically to phosphoinositides, few are well understood. One group of PH domains appears to bind both phosphoinositides (with little specificity) and Arf (ADP-ribosylation factor) family small G-proteins, and are targeted to the Golgi apparatus where both phosphoinositides and the relevant Arfs are both present. Here, the PH domains may function as coincidence detectors. A central challenge in understanding the majority of PH domains is to establish whether the very low affinity phosphoinositide binding reported in many cases has any functional relevance. For PH domains from dynamin and from Dbl family proteins, this weak binding does appear to be functionally important, although its precise mechanistic role is unclear. In many other cases, it is quite likely that alternative binding partners are more relevant, and that the observed PH domain homology represents conservation of structural fold rather than function. PMID:17233582

Lemmon, Mark A

2007-01-01

296

Bazi Bu?daygil Dane Yemlerinin Ekstrakt Viskoziteleri ?le pH De?erlerinin Saptanmasi I. Bazi Bu?day Varyetelerinin Ekstrakt Viskoziteleri ?le pH De?erlerinin Saptanmasi1  

Microsoft Academic Search

In this experiment, effect of grinding, variety, water soaking and autoclaving treatments on extract viscosity and pH value in some wheat varieties were determined. It has been found that grinding has a prominent effect on water, alkali & acid extract viscosities. In general, higher viscosity was yielded in 0.5mm ground in contrast to 1mm ground. Water soaking and autoclaving treatments

Sami Mahdi AHMED; Figen KIRKPINAR

297

Submillimeter Array Observations Toward the Massive Star-forming Core MM1 of W75N  

Microsoft Academic Search

The massive star-forming core MM1 of W75N was observed using the Submillimeter Array with ~1'' and 2'' spatial resolutions at 217 and 347 GHz, respectively. From the 217 GHz continuum we found that the MM1 core consists of two sources, separated by about 1'': MM1a (~0.6 M sun) and MM1b (~1.4 M sun), located near the radio continuum sources VLA

Y. C. Minh; Y.-N. Su; H.-R. Chen; S.-Y. Liu; C.-H. Yan; S.-J. Kim

2010-01-01

298

The Herschel Multi-tiered Extragalactic Survey: SPIRE-mm photometric redshifts  

Microsoft Academic Search

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 500mum 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

I. G. Roseboom; R. J. Ivison; T. R. Greve; A. Amblard; V. Arumugam; R. Auld; H. Aussel; M. Bethermin; A. Blain; J. Bock; A. Boselli; D. Brisbin; V. Buat; D. Burgarella; N. Castro-Rodrguez; A. Cava; P. Chanial; E. Chapin; S. Chapman; D. L. Clements; A. Conley; L. Conversi; A. Cooray; C. D. Dowell; J. S. Dunlop; E. Dwek; S. Eales; D. Elbaz; D. Farrah; A. Franceschini; J. Glenn; M. Griffin; M. Halpern; E. Hatziminaoglou; E. Ibar; K. Isaak; G. Lagache; L. Levenson; N. Lu; S. Madden; B. Maffei; G. Mainetti; L. Marchetti; G. Marsden; G. Morrison; A. M. J. Mortier; H. T. Nguyen; B. O'Halloran; S. J. Oliver; A. Omont; M. J. Page; P. Panuzzo; A. Papageorgiou; C. P. Pearson; I. Prez-Fournon; M. Pohlen; J. I. Rawlings; G. Raymond; D. Rigopoulou; D. Rizzo; G. Rodighiero; M. Rowan-Robinson; B. Schulz; Douglas Scott; N. Seymour; D. L. Shupe; A. J. Smith; J. A. Stevens; M. Symeonidis; M. Trichas; K. E. Tugwell; M. Vaccari; I. Valtchanov; J. D. Vieira; M. P. Viero; L. Vigroux; J. Wardlow; L. Wang; G. Wright; C. K. Xu; M. Zemcov

2011-01-01

299

Effect of pH on the accumulation kinetics of pentachlorophenol in goldfish  

Microsoft Academic Search

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 g PCP\\/L in a static system buffered with 7.5 mM bicine orN,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

Guy R. Stehly; William L. Hayton

1990-01-01

300

Divalent metals and pH alter raltegravir disposition in vitro.  

PubMed

Raltegravir shows marked pharmacokinetic variability in patients, with gastrointestinal pH and divalent-metal binding being potential factors. We investigated raltegravir solubility, lipophilicity, pK(a), and permeativity in vitro to elucidate known interactions with omeprazole, antacids, and food, all of which increase gastric pH. Solubility of raltegravir was determined at pH 1 to 8. Lipophilicity of raltegravir was determined using octanol-water partition. Raltegravir pK(a) was determined using UV spectroscopy. The effects of pH, metal salts, and omeprazole on the cellular permeativity of raltegravir were determined using Caco-2 monolayers. Cellular accumulation studies were used to determine the effect of interplay between pH and ABCB1 transport on raltegravir accumulation. Samples were analyzed using liquid chromatography-tandem mass spectroscopy (LC-MS/MS) or scintillation counting. Raltegravir at 10 mM was partly insoluble at pH 6.6 and below. Raltegravir lipophilicity was pH dependent and was reduced as pH was increased from 5 to 9. The pK(a) of raltegravir was 6.7. Raltegravir cellular permeativity was heavily influenced by changes in extracellular pH, where apical-to-basolateral permeativity was reduced 9-fold (P < 0.05) when apical pH was increased from 5 to 8.5. Raltegravir cellular permeativity was also reduced in the presence of magnesium and calcium. Omeprazole did not alter raltegravir cellular permeativity. Cellular accumulation of raltegravir was increased independently by inhibiting ABCB1 and by lowering extracellular pH from pH 8 to 5. Gastrointestinal pH and polyvalent metals can potentially alter the pharmacokinetic properties of raltegravir, and these data provide an explanation for the variability in raltegravir exposure in patients. The evaluation of how divalent-metal-containing products, such as multivitamins, that do not affect gastric pH alter raltegravir pharmacokinetics in patients is now justified. PMID:22450971

Moss, Darren M; Siccardi, Marco; Murphy, Matthew; Piperakis, Michael M; Khoo, Saye H; Back, David J; Owen, Andrew

2012-03-26

301

Challenges for economical growth of high quality 300 mm CZ Si crystals  

Microsoft Academic Search

The changeover from 200 mm to 300 mm is required by the semiconductor industry due to the necessity for larger chip sizes and demand for decreasing cost. However, the cost for 300 mm crystal growth is likely to rise owing to larger puller, enlargement of hot zone, expensive silica crucibles and longer growth process times caused by lower growth rates

Erich Tomzig; Wilfried von Ammon; Erich Dornberger; Ulrich Lambert; Werner Zulehner

1999-01-01

302

rates of feldspar dissolution at pH 37 with 08 m M oxalic acid  

Microsoft Academic Search

Feldspar dissolution rates were measured in flow-through reactors, over a pH range of 37, oxalic acid concentration of 08 mM, and feldspar compositional range of An0?An76. Dissolution rates in 0 and 1 mM concentrations of oxalic acid increased linearly with increasing mole percent anorthite in the solid. Dissolution was nonstoichiometric in oxalic acid, due to a preferential release of Al

Lisa L. Stillings; James I. Drever; Susan L. Brantley; Yanting Sun; Rachael Oxburgh

1996-01-01

303

Simultaneous water desalination and electricity generation in a microbial desalination cell with electrolyte recirculation for pH control.  

PubMed

A recirculation microbial desalination cell (rMDC) was designed and operated to allow recirculation of solutions between the anode and cathode chambers. This recirculation avoided pH imbalances that could inhibit bacterial metabolism. The maximum power density was 93129mW/m(2) with a 50mM phosphate buffer solution (PBS) and 77630mW/m(2) with 25mM PBS. These power densities were higher than those obtained without recirculation of 69810mW/m(2) (50mM PBS) and 50811mW/m(2) (25mM PBS). The salt solution (20g/L NaCl) was reduced in salinity by 341% (50mM) and 372% (25mM) with recirculation (rMDC), and by 391% (50mM) and 253% (25mM) without recirculation (MDC). These results show that electrolyte recirculation using an rMDC is an effective method to increase power and achieve efficient desalination by eliminating pH imbalances. PMID:22200556

Qu, Youpeng; Feng, Yujie; Wang, Xin; Liu, Jia; Lv, Jiangwei; He, Weihua; Logan, Bruce E

2011-11-25

304

Submillimeter Array Observations Toward the Massive Star-forming Core MM1 of W75N  

NASA Astrophysics Data System (ADS)

The massive star-forming core MM1 of W75N was observed using the Submillimeter Array with ~1'' and 2'' spatial resolutions at 217 and 347 GHz, respectively. From the 217 GHz continuum we found that the MM1 core consists of two sources, separated by about 1'': MM1a (~0.6 M sun) and MM1b (~1.4 M sun), located near the radio continuum sources VLA 2/VLA 3 and VLA 1, respectively. Within MM1b, two gas clumps were found to be expanding away from VLA 1 at about 3 km s-1, as a result of the most recent star formation activity in the region. Observed molecular lines show emission peaks at two positions, MM1a and MM1b: sulfur-bearing species have emission peaks toward MM1a, but methanol and saturated species at MM1b. We identified high-temperature (~200 K) gas toward MM1a and the hot core in MM1b. This segregation may result from the evolution of the massive star-forming core. In the very early phase of star formation, the hot core is seen through the evaporation of dust ice-mantle species. As the mantle species are consumed via evaporation the high-temperature gas species (such as the sulfur-bearing molecules) become bright. The SiO molecule is unique in having an emission peak exactly at the VLA 2 position, probably tracing a shock powered by VLA 2. The observed sulfur-bearing species show similar abundances both in MM1a and MM1b, whereas the methanol and saturated species show significant abundance enhancement toward MM1b, by about an order of magnitude, compared to MM1a.

Minh, Y. C.; Su, Y.-N.; Chen, H.-R.; Liu, S.-Y.; Yan, C.-H.; Kim, S.-J.

2010-11-01

305

SERC: PhET Interactive Science Simulations  

NSDL National Science Digital Library

These web pages provide background information about and help with using the PhET simulations for teaching and learning. These research-based, interactive computer simulations in physics, chemistry, math, and other sciences can be run online or downloaded for free from the PhET website. They emphasize the connections between real-life phenomena and the underlying science, and help make the visual and conceptual models of expert scientists accessible to students. This SERC Pedagogical Module provides a background on the PhET simulations, the research foundation behind the simulations, and advice on how they can be used. There are also a series of example activities based on PhET simulations. The SERC web site includes a large collection of similar pedagogical modules of best practices in science teaching, and related example activities of these teaching methods.

Mckagan, Sarah B.

2010-11-02

306

Partially Biodegradable Temperature and PH Sensitive Hydrogel.  

National Technical Information Service (NTIS)

Partially biodegradable hydrogel that changes its volume and shape in response to change in pH and/or temperature is prepared by UV irradiation of composition comprising dextran-maleic acid monoester and N-isopropylacrylamide.

C. C. Chu X. Z. Zhang

2003-01-01

307

Aqueous-Solution pH Scales  

Microsoft Academic Search

The parallel existence of two forms of pH scale is considered, which is unique for the international metrological community. The basic advantages and shortcomings are considered for the multireference NIST scale and the single-reference BSI one.

O. V. Karpov; I. I. Maksimov; A. L. Seifer

2000-01-01

308

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

309

Effects of pH on NaCl tolerance of American elm ( Ulmus americana ) seedlings inoculated with Hebeloma crustuliniforme and Laccaria bicolor  

Microsoft Academic Search

In the present study, we investigated the effects of pH treatments on NaCl tolerance in mycorrhizal and non-mycorrhizal American\\u000a elm. American elm (Ulmus americana) seedlings were inoculated with Hebeloma crustuliniforme, Laccaria bicolor or with both mycorrhizal fungi and subsequently subjected to different pH solutions (pH 3, 6 and 9) containing 0mM (control)\\u000a and 60mM NaCl for 4weeks. Inoculation with the

Mnica Calvo-Polanco; Melanie D. Jones; Janusz J. Zwiazek

2009-01-01

310

Equilibrium structure of PH 2Br  

Microsoft Academic Search

The structure of monobromophosphane has been calculated ab initio at the MP2 and CCSD(T) levels using a polarized triple-zeta basis set. For comparison, a relativistic compact effective core potential has also been used for Br. Equilibrium and ground state rotational constants as well as centrifugal distortion constants have been predicted for both isotopic species PH279Br and PH281Br. The rz and

Jrgen Breidung; Walter Thiel; Jean Demaison

1997-01-01

311

Baccalaureate Origins of Ph.D. Physicists  

Microsoft Academic Search

Using the data gathered by the National Academy of Sciences about the baccalaureate origin of Ph.D. physicists for the periods 1936-1945, 1946-1950, and 1951-1955, the authors detected certain trends in the undergraduate training of Ph.D. physicists. It was found that the undergraduate training of physicists who earned doctorates during the years covered by this study was concentrated in a small

B. Richard Siebring; Duane H. Schwahn

1959-01-01

312

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 CaCl 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

313

Temperaturmessung in Sphaerisch Konvergierenden Detonationswellen. Experimentelle Ergebnisse in der 800 mm-Apparatur (Temperature Measurement in Spherically Conveying Detonation Waves. Experimental Results with an 800 mm Apparatus).  

National Technical Information Service (NTIS)

The gas temperature in spherically converging detonation waves in a stoichiometric propane-oxygen mixture in a hemisphere of inner diameter 800 mm was spectroscopically investigated. For the temperature measurement 5% Ar was added to the mixture and the i...

K. Terao

1985-01-01

314

Identification and characterization of MmORC4 and MmORC5, two subunits of the mouse origin of replication recognition complex.  

PubMed

Two new members of the mouse origin recognition complex (ORC) have been cloned that are closely related to Saccharomyces cerevisiae ORC4 and ORC5 as well as to their human homolog. Both MmORC4p and MmORC5p have a putative nucleotide triphosphate binding motif. Transcription of MmORC4 and MmORC5 is not suppressed in mouse NIH3T3 fibroblasts made quiescent by serum starvation. The transcription levels of both ORC genes are constantly high in all phases of the cell cycle. A screen based on the two-hybrid approach suggests that the product of the ORC4 gene interacts with the ORC2, but not with the ORC1 protein. The conservation of structure among members of the ORC4- and ORC5-related family of proteins suggests that these proteins play a key role in the initiation of DNA replication in all eukaryotes. PMID:10460412

Springer, J; Kneissl, M; Ptter, V; Grummt, F

1999-08-01

315

Fotografias Aeras Verticais 35 mm para Mapear Povoamentos de Bracatinga em Diferentes Idades (35 mm Vertical Aerial Photographs for Mapping Stands of Bracatinga in Different Age Classes).  

National Technical Information Service (NTIS)

The value of 35 mm vertical aerial photographs used to identify and map Mimosa scabrella Benth (bracatinga) in different age classes is shown. It was possible to differentiate three age classes of bracatinga using the elements of image interpretation. Com...

A. A. Disperati N. C. Rosot J. Robertodossantos

1986-01-01

316

Ambulatory esophageal pH monitoring.  

PubMed

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 cycle and the relationship of symptoms to pH drops. Studies in adult asthmatics demonstrate abnormal amounts of acid reflux by 24-hour esophageal pH monitoring in >50% of patients. Likewise, large studies in patients with chronic ENT complaints find abnormal acid reflux values in 50-80% of patients. Several problems and issues with ambulatory pH monitoring still need addressing, including (1) the need for dual pH monitoring, (2) artifact and reproducibility, (3) normal values, (4) role in the initial diagnosis, and (5) role in the follow-up of poorly responding patients. PMID:9422638

Richter, J E

1997-11-24

317

Unsedated peroral wireless pH capsule placement vs. standard pH testing: A randomized study and cost analysis  

PubMed Central

Background Wireless capsule pH-metry (WC) is better tolerated than standard nasal pH catheter (SC), but endoscopic placement is expensive. Aims: to confirm that non-endoscopic peroral manometric placement of WC is as effective and better tolerated than SC and to perform a cost analysis of the available esophageal pH-metry methods. Methods Randomized trial at 2 centers. Patients referred for esophageal pH testing were randomly assigned to WC with unsedated peroral placement or SC after esophageal manometry (ESM). Primary outcome was overall discomfort with pH-metry. Costs of 3 different pH-metry strategies were analyzed: 1) ESM?+?SC, 2) ESM?+?WC and 3) endoscopically placed WC (EGD?+?WC) using publicly funded health care system perspective. Results 86 patients (mean age 51??2?years, 71% female) were enrolled. Overall discomfort score was less in WC than in SC patients (26??4?mm vs 39??4?mm VAS, respectively, p?=?0.012) but there were no significant group differences in throat, chest, or overall discomfort during placement. Overall failure rate was 7% in the SC group vs 12% in the WC group (p?=?0.71). Per patient costs ($Canadian) were $1475 for EGD?+?WC, $1014 for ESM?+?WC, and $906 for ESM?+?SC. Decreasing the failure rate of ESM?+?WC from 12% to 5% decreased the cost of ESM?+?WC to $991. The ESM?+?SC and ESM?+?WC strategies became equivalent when the cost of the WC device was dropped from $292 to $193. Conclusions Unsedated peroral WC insertion is better tolerated than SC pH-metry both overall and during placement. Although WC is more costly, the extra expense is partially offset when the higher patient and caregiver time costs of SC are considered. Trial registration Clinicaltrials.gov Identifier NCT01364610

2012-01-01

318

Microstructural behavior of rapidly solidified and extruded Al14wt%Ni14wt%Mm (Mm, misch metal) alloy powders  

Microsoft Academic Search

The effect of powder size on the microstructure and mechanical properties was studied in gas-atomized Al-14wt%Ni-14wt%Mm (Mm: misch metal) alloy powder and their extrudates. The alloy powders showed different microstructures depending on the powder size. With decreasing powder size, formation of intermetallic compounds such as Al3Ni, Al11Ce3 and Al11La3 was suppressed. The powders less than 26 ?m in diameter consisted

Soon Jik Hong; Taek-Soo Kim; Hyoung Seop Kim; Won Tae Kim; Byong Sun Chun

1999-01-01

319

Assessment of coronary artery calcium by using volumetric 320-row multi-detector computed tomography: comparison of 0.5mm with 3.0mm slice reconstructions  

Microsoft Academic Search

The purpose of this study was to assess the performance of 0.5 versus 3.0mm slice reconstructions in depicting coronary calcium\\u000a with special attention to patients having zero calcium scores at 3.0mm reconstructions by using computed tomography (CT).\\u000a Imaging was performed by volumetric 320-detector row CT. Scans of 100 patients with a negative and 100 patients with a positive\\u000a Agatston score

Noortje van der BijlPaul; Paul W. de Bruin; Jacob GeleijnsJeroen; Jeroen J. Bax; Joanne D. Schuijf; Albert de Roos; Lucia J. M. Kroft

2010-01-01

320

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

321

Development of pH measurement system for legal traceability of pH standard solutions.  

PubMed

The best reproducible technology of pH measurement for precise pH buffer solutions regulated by Japanese Industrial Standards (JIS) was studied. A pH meter was devised with a high resolution of +/- 0.0001 pH. An 18-bit analog-to-digital converter is used, one-bit resolution corresponding to 0.0019 mV (ca. 0.000032 pH) against an input electrode potential +/- 500 mV. Digital data were treated smoothly for some types of noise, a reproducibility of +/- 0.0002 pH being obtained with a potentiometer. A flow cell was devised to attain temperature control within +/- 0.03 degrees C and air-tight measurement prevented contamination with carbon dioxide. Also, the flow cell has a structure such that potassium chloride (KCl) inner solution effused from a ceramic junction of the reference electrode designed so as not to touch the glass membrane. A combination pH electrode (a glass electrode and a reference electrode) was assembled to minimize the dead volume of sample solution. This highly sensitive pH measuring system, consisting of a pH meter, a flow cell, a combination pH electrode, a circulating water thermostat and a peristaltic pump, was used for the certification of pH standard solutions in Japanese metrological law. The performance of this system was within +/- 0.0006 pH reproducibility and 20-30 min response time (5 min within +/- 0.0002 pH) at a sample flow rate of 3 ml min (-1). PMID:18966620

Ito, S; Hachiya, H; Baba, K; Eto, M; Asano, Y; Wada, H

1996-09-01

322

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.

Kwast, K E; Hand, S C

1996-01-01

323

?-Galactoside-binding activity of human galectin-1 at basic pH  

NASA Astrophysics Data System (ADS)

?-Galactoside-binding activity of human galectin-1 (hGal-1) was evaluated at pH 7-9.5 by fluorescence spectroscopy from the fraction bound to lactose gel (Y) and the lactose binding constant (Kb). Y decreases at pH > 8.2 0.1 in the absence of NaCl, while it is constant in the presence of 150 mM NaCl. On the other hand, Kb is independent of pH and the NaCl concentration at basic pH. Analysis of Raman spectrum has shown that the pKa of Cys residues of hGal-1 is 8.5 0.1 on average, indicating that about 40% of the six Cys residues of hGal-1 would be deprotonated at pH 8.2. The pH dependence of Y is explained by an increase of Coulombic repulsion among negatively charged hGal-1 on the lactose gel surface. This result suggests that Y is not always a good indicator of the ?-galactoside-binding activity of galectins, which contain many Cys residues.

Hiramatsu, Hirotsugu; Takeuchi, Katsuyuki; Fukuda, Koki; Nishino, Tomohide

2013-06-01

324

Susceptibility of human malaria parasites to chloroquine is pH dependent.  

PubMed Central

Chloroquine (CQ) accumulates in the acidic food vacuole of intraerythrocytic malaria parasites (Plasmodium falciparum) by virtue of its weak base properties. In the present work, the extent of CQ accumulation was determined by the transvacuolar pH gradient: modification of the latter--either by changing the external pH or by adding the acidotropic agent NH4Cl--led to a corresponding change in CQ distribution between cells and medium. Changes in pH gradient provoked a change in the susceptibility of parasites to CQ: at external pH values of 8.0, 7.4, and 6.8, the IC50 values for CQ were 0.48 X 10(-7) M, 1.8 X 10(-7) M, and 3.3 X 10(-7) M, respectively. Marked resistance to CQ (IC50 = 9.8 X 10(-7) M) was conferred upon cells by exposing them simultaneously to CQ and 10 mM NH4Cl, at pH 7.4. The final concentration of CQ attained within the acidic compartment of the parasite was correlated with inhibition of parasite growth. At therapeutic drug levels, CQ accumulation caused minor changes in the food vacuole pH, whereas at higher CQ concentrations substantial alkalinization was observed. The antimalarial activity of CQ is suggested to be exerted by the interference of the high concentrations of the accumulated drug with vital functions of the food vacuole.

Yayon, A; Cabantchik, Z I; Ginsburg, H

1985-01-01

325

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.

2011-09-01

326

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

327

Monte Carlo evaluation of CTDI? in infinitely long cylinders of water, polyethylene and PMMA with diameters from 10 mm to 500 mm  

PubMed Central

Monte Carlo simulations were used to evaluate the radiation dose to infinitely long cylinders of water, polyethylene, and poly(methylmethacrylate) (PMMA) from 10 to 500 mm in diameter. Radiation doses were computed by simulating a 10 mm divergent primary beam striking the cylinder at z=0, and the scattered radiation in the ?z and +z directions was integrated out to infinity. Doses were assessed using the total energy deposited divided by the mass of the 10-mm-thick volume of material in the primary beam. This approach is consistent with the notion of the computed tomography dose index (CTDI) integrated over infinite z, which is equivalent to the dose near the center of an infinitely long CT scan. Monoenergetic x-ray beams were studied from 5 to 140 keV, allowing polyenergetic x-ray spectra to be evaluated using a weighted average. The radiation dose for a 10-mm-thick CT slice was assessed at the center, edge, and over the entire diameter of the phantom. The geometry of a commercial CT scanner was simulated, and the computed results were in good agreement with measured doses. The absorbed dose in water for 120 kVp x-ray spectrum with no bow tie filter for a 50 mm cylinder diameter was about 1.2 mGy per mGy air kerma at isocenter for both the peripheral and center regions, and dropped to 0.84 mGy?mGy for a 500-mm-diam water phantom at the periphery, where the corresponding value for the center location was 0.19 mGy?mGy. The influence of phantom composition was studied. For a diameter of 100 mm, the dose coefficients were 1.23 for water, 1.02 for PMMA, and 0.94 for polyethylene (at 120 kVp). For larger diameter phantoms, the order changedfor a 400 mm phantom, the dose coefficient of polyethylene (0.25) was greater than water (0.21) and PMMA (0.16). The influence of the head and body bow tie filters was also studied. For the peripheral location, the dose coefficients when no bow tie filter was used were high (e.g., for a water phantom at 120 kVp at a diameter of 300 mm, the dose coefficient was 0.97). The body bow tie filter reduces this value to 0.62, and the head bow tie filter (which is not actually designed to be used for a 300 mm object) reduces the dose coefficient to 0.42. The dose in CT is delivered both by the absorption of primary and scattered x-ray photons, and at the center of a water cylinder the ratio of scatter to primary (SPR) doses increased steadily with cylinder diameter. For water, a 120 kVp spectrum and a cylinder diameter of 200 mm, the SPR was 4, and this value grew to 9 for a diameter of 350 mm and to over 16 for a 500-mm-diam cylinder. A freely available spreadsheet was developed to allow the computation of radiation dose as a function of object diameter (10500 mm), composition (water, polyethylene, PMMA), and beam energy (10140 keV, 40140 kVp).

Zhou, Hong; Boone, John M.

2008-01-01

328

Monte Carlo evaluation of CTDI{sub {infinity}} in infinitely long cylinders of water, polyethylene and PMMA with diameters from 10 mm to 500 mm  

SciTech Connect

Monte Carlo simulations were used to evaluate the radiation dose to infinitely long cylinders of water, polyethylene, and poly(methylmethacrylate) (PMMA) from 10 to 500 mm in diameter. Radiation doses were computed by simulating a 10 mm divergent primary beam striking the cylinder at z=0, and the scattered radiation in the -z and +z directions was integrated out to infinity. Doses were assessed using the total energy deposited divided by the mass of the 10-mm-thick volume of material in the primary beam. This approach is consistent with the notion of the computed tomography dose index (CTDI) integrated over infinite z, which is equivalent to the dose near the center of an infinitely long CT scan. Monoenergetic x-ray beams were studied from 5 to 140 keV, allowing polyenergetic x-ray spectra to be evaluated using a weighted average. The radiation dose for a 10-mm-thick CT slice was assessed at the center, edge, and over the entire diameter of the phantom. The geometry of a commercial CT scanner was simulated, and the computed results were in good agreement with measured doses. The absorbed dose in water for 120 kVp x-ray spectrum with no bow tie filter for a 50 mm cylinder diameter was about 1.2 mGy per mGy air kerma at isocenter for both the peripheral and center regions, and dropped to 0.84 mGy/mGy for a 500-mm-diam water phantom at the periphery, where the corresponding value for the center location was 0.19 mGy/mGy. The influence of phantom composition was studied. For a diameter of 100 mm, the dose coefficients were 1.23 for water, 1.02 for PMMA, and 0.94 for polyethylene (at 120 kVp). For larger diameter phantoms, the order changed--for a 400 mm phantom, the dose coefficient of polyethylene (0.25) was greater than water (0.21) and PMMA (0.16). The influence of the head and body bow tie filters was also studied. For the peripheral location, the dose coefficients when no bow tie filter was used were high (e.g., for a water phantom at 120 kVp at a diameter of 300 mm, the dose coefficient was 0.97). The body bow tie filter reduces this value to 0.62, and the head bow tie filter (which is not actually designed to be used for a 300 mm object) reduces the dose coefficient to 0.42. The dose in CT is delivered both by the absorption of primary and scattered x-ray photons, and at the center of a water cylinder the ratio of scatter to primary (SPR) doses increased steadily with cylinder diameter. For water, a 120 kVp spectrum and a cylinder diameter of 200 mm, the SPR was 4, and this value grew to 9 for a diameter of 350 mm and to over 16 for a 500-mm-diam cylinder. A freely available spreadsheet was developed to allow the computation of radiation dose as a function of object diameter (10-500 mm), composition (water, polyethylene, PMMA), and beam energy (10-140 keV, 40-140 kVp)

Zhou Hong; Boone, John M. [Department of Radiology and Department of Radiation Oncology, University of California, Davis, Sacramento, California 95817 (United States); Department of Radiology and Department of Biomedical Engineering, University of California, Davis, Sacramento, California 95817 (United States)

2008-06-15

329

Molecular dynamics investigation on a series of HIV protease inhibitors: assessing the performance of MM-PBSA and MM-GBSA approaches.  

PubMed

The binding free energies (?G(Bind)) obtained from molecular mechanics with Poisson-Boltzmann surface area (MM-PBSA) or molecular mechanics with Generalized Born surface area (MM-GBSA) calculations using molecular dynamics (MD) trajectories are the most popular procedures to measure the strength of interactions between a ligand and its receptor. Several attempts have been made to correlate the ?G(Bind) and experimental IC(50) values in order to observe the relationship between binding strength of a ligand (with its receptor) and its inhibitory activity. The duration of MD simulations seems very important for getting acceptable correlation. Here, we are presenting a systematic study to estimate the reasonable MD simulation time for acceptable correlation between ?G(Bind) and experimental IC(50) values. A comparison between MM-PBSA and MM-GBSA approaches is also presented at various time scales. MD simulations (10 ns) for 14 HIV protease inhibitors have been carried out by using the Amber program. MM-PBSA/GBSA based ?G(Bind) have been calculated and correlated with experimental IC(50) values at different time scales (0-1 to 0-10 ns). This study clearly demonstrates that the MM-PBSA based ?G(Bind) (?G(Bind)-PB) values provide very good correlation with experimental IC(50) values (quantitative and qualitative) when MD simulation is carried out for a longer time; however, MM-GBSA based ?G(Bind) (?G(Bind)-GB) values show acceptable correlation for shorter time of simulation also. The accuracy of ?G(Bind)-PB increases and ?G(Bind)-GB remains almost constant with the increasing time of simulation. PMID:23121465

Srivastava, Hemant Kumar; Sastry, G Narahari

2012-11-08

330

pH. Training Module 5.305.2.77.  

ERIC Educational Resources Information Center

|This document is an instructional module package prepared in objective form for use by an instructor familiar with pH, measurement of pH with a pH meter and maintenance of pH meter electrodes. Included are objectives, instructor guides, student handouts and transparency masters. This module considers the definition of pH, types of electrodes and

Kirkwood Community Coll., Cedar Rapids, IA.

331

Production of microbial rhamnolipid by Pseudomonas aeruginosa MM1011 for ex situ enhanced oil recovery.  

PubMed

Recently, several investigations have been carried out on the in situ bacteria flooding, but the ex situ biosurfactant production and addition to the sand pack as agents for microbial enhanced oil recovery (MEOR) has little been studied. In order to develop suitable technology for ex situ MEOR processes, it is essential to carry out tests about it. Therefore, this work tries to fill the gap. The intention of this study was to investigate whether the rhamnolipid mix could be produced in high enough quantities for enhanced oil recovery in the laboratory scale and prove its potential use as an effective material for field application. In this work, the ability of Pseudomonas aeruginosa MM1011 to grow and produce rhamnolipid on sunflower as sole carbon source under nitrogen limitation was shown. The production of Rha-C10-C10 and Rha2-C10-C10 was confirmed by thin-layer chromatography and high-performance liquid chromatography analysis. The rhamnolipid mixture obtained was able to reduce the surface and interfacial tension of water to 26 and 2 mN/m, respectively. The critical micelle concentration was 120 mg/L. Maximum rhamnolipid production reached to about 0.7 g/L in a shake flask. The yield of rhamnolipid per biomass (Y RL/x ), rhamnolipid per sunflower oil (Y RL/s ), and the biomass per sunflower oil (Y x/s ) for shake flask were obtained about 0.01, 0.0035, and 0.035 g g(-1), respectively. The stability of the rhamnolipid at different salinities, pH and temperature, and also, its emulsifying activity has been investigated. It is an effective surfactant at very low concentrations over a wide range of temperatures, pHs, and salt concentrations, and it also has the ability to emulsify oil, which is essential for enhanced oil recovery. With 120 mg/L rhamnolipid, 27 % of original oil in place was recovered after water flooding from a sand pack. This result not only suggests rhamnolipids as appropriate model biosurfactants for MEOR, but it even shows the potential as a biosurfactant of choice for actual MEOR applications. PMID:23640261

Amani, Hossein; Mller, Markus Michael; Syldatk, Christoph; Hausmann, Rudolf

2013-05-03

332

300 mm factory automation experience and challenges for wafer foundry fabs  

Microsoft Academic Search

As the semiconductor industry increases interest in 300 mm wafer size transition, Taiwan Semiconductor Manufacturing Company (TSMC) is also participating in the 300 mm development and mass production. TSMC uses a pilot line of 4.5 K monthly output capacity to gain process and tool expertise and to develop appropriate 300 mm factory automation know-how for the set-up of the next

Chin-Hui Hung; Li-Ren Lin

2001-01-01

333

Development of buffer layers on 30 mm wide textured metal substrates for REBCO coated conductors  

Microsoft Academic Search

We have been studying REBa2Cu3Ox (RE: rare earth elements) coated conductors on clad-type substrates. We developed coated conductors on the 10mm wide clad-type tape, and succeeded in obtaining the maximum critical current of 380A\\/cm with the 2.0?m thick GdBa2Cu3Ox superconducting film. At present, we are trying to widen the tape width from 10mm to 30mm in order to increase production

T. Yamaguchi; H. Ota; K. Ohki; M. Konishi; K. Ohmatsu

2010-01-01

334

Using transact-SQL and simulation techniques to create virtual M&M'S  

Microsoft Academic Search

The M&M problem is an example of a nontrivial yet simple method for summarizing sampled data that are then used in making decisions. Previous work by the author used client-side JavaScript and Active Server Pages to create virtual M&M's. This paper moves the generation of the virtual M&M's to a SQL Server database server. In doing so, a number of

Robin M. Snyder

2002-01-01

335

Leaching of genetically modified Pseudomonas fluorescens through organic soils: Influence of temperature, soil pH, and roots  

Microsoft Academic Search

The effects of soil temperature and bulk soil pH on the vertical translocation of a genetically modified Pseudomonas fluorescens inoculum were studied in reconstituted soil microcosms, in the presence and absence of growing Lolium perenne roots. The inoculated microcosms received one rainfall event per day (5 mm h-1 for 6 h) for 5 days and the resulting leachate was quantitatively

Jane S. Kemp; Eric Paterson; Shimna M. Gammack; Malcolm S. Cresser; Kenneth Killham

1992-01-01

336

Fiber-Optic pH Sensor  

NASA Astrophysics Data System (ADS)

The new enhancement in the determination of pH using optical fiber system is described here. This work uses the membrane made of cellulose acetate membrane for reagent immobilization and congo red (pKa 3.7) and neutral red (pKa 7.2) as pH indicators. An effective covalent chemical binding procedure is used to immobilize the indicatorsE The response time, reversibility, linear range, reproducibility, and long-term stability of fiber optic sensor with congo red as well as neutral red have been determined. The linear range measured for the sensor based on the congo red and neutral red is 4.2-6.3 and 4.1-9.0, respectively. The response time of sensor membrane is measured by varying the substance pH values between 11.0 and 2.0.

Ganesh, A. Balaji; Radhakrishnan, T. K.

337

Ph.D.: Asset or liability?  

NASA Astrophysics Data System (ADS)

I am a young scientist on the verge of leaving science due to lack of opportunity, and I know many others in my situation. Times are rapidly getting harder for us. A degree from a name university, publications, and energy are not enough to get and hold a place in the academic world.The great myth of the Ph.D. shortage inflicted on us by former NSF Director Erich Bloch has now been exploded, I hope. Another myth that needs exploding is that a Ph.D. is a good preparation for work outside of academia. Unless it is in an applied field (for example, hydrogeology), the Ph.D. is more of a liability than an asset in a job search.

Snow, Jonathan E.

338

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.

Mullins, Jessica

339

Improvement of biohydrogen production by Enterobacter cloacae IIT-BT 08 under regulated pH.  

PubMed

The present study investigates the effect of pH and intermediate products formation on biological hydrogen production using Enterobacter cloacae IIT-BT 08. Initial pH was found to have a profound effect on hydrogen production potential, while regulating the pH 6.5 throughout the fermentation was found to increase the cumulative hydrogen production rate and yield significantly. Modified Gompertz equation was used to fit the cumulative hydrogen production curves to obtain the hydrogen production potential P, the hydrogen production rate R and lag phase ?. At regulated pH 6.5, higher H(2) yield (3.1molH(2)mol(-1) glucose), specific hydrogen production potential (798.1mL/g) and specific rate of H(2) production (72.1mLL(-1)h(-1)g(-1)) were obtained. The volatile fatty acid profile showed butyrate, ethanol and acetate as the major end metabolites of fermentation under the operating pH conditions tested; however, their pattern of distribution was pH dependent. At the optimum pH of 6.5, the acetate to butyrate ratio (A/B ratio) was found to be higher than that at any other pH. The study also investigates the effect of sodium ions on biohydrogen production potential. It was also found that sodium ion concentration up to 250mM enhanced the hydrogen production potential; however, any further increase in the metal ion concentration had an inhibitory effect. PMID:21185338

Khanna, Namita; Kotay, Shireen Meher; Gilbert, J Jose; Das, Debabrata

2010-12-23

340

MUSTANG 3.3 mm CONTINUUM OBSERVATIONS OF CLASS 0 PROTOSTARS  

SciTech Connect

We present observations of six Class 0 protostars at 3.3 mm (90 GHz) using the 64 pixel MUSTANG bolometer camera on the 100 m Green Bank Telescope. The 3.3 mm photometry is analyzed along with shorter wavelength observations to derive spectral indices (S{sub {nu}} {proportional_to} {nu}{sup {alpha}}) of the measured emission. We utilize previously published dust continuum radiative transfer models to estimate the characteristic dust temperature within the central beam of our observations. We present constraints on the millimeter dust opacity index {beta} between 0.862 mm, 1.25 mm, and 3.3 mm. {beta}{sub mm} typically ranges from 1.0 to 2.4 for Class 0 sources. The relative contributions from disk emission and envelope emission are estimated at 3.3 mm. L483 is found to have negligible disk emission at 3.3 mm, while L1527 is dominated by disk emission within the central beam. The {beta}{sup disk}{sub mm} {<=} 0.8-1.4 for L1527 indicates that grain growth is likely occurring in the disk. The photometry presented in this paper may be combined with future interferometric observations of Class 0 envelopes and disks.

Shirley, Yancy L.; Bolin, David E. [Steward Observatory, University of Arizona, 933 Cherry Avenue, Tucson, AZ 85721 (United States); Mason, Brian S.; Mangum, Jeffrey G. [NRAO, 520 Edgemont Road, Charlottesville, VA 22903-2475 (United States); Devlin, Mark J.; Dicker, Simon R.; Korngut, Phillip M. [University of Pennsylvania, 209 South 33rd Street, Philadelphia, PA 19104-6396 (United States)

2011-02-15

341

Computed tomography dose assessment for a 160 mm wide, 320 detector row, cone beam CT scanner  

PubMed Central

Computed tomography (CT) dosimetry should be adapted to the rapid developments in CT technology. Recently a 160 mm wide, 320 detector row, cone beam CT scanner that challenges the existing Computed Tomography Dose Index (CTDI) dosimetry paradigm was introduced. The purpose of this study was to assess dosimetric characteristics of this cone beam scanner, to study the appropriateness of existing CT dose metrics and to suggest a pragmatic approach for CT dosimetry for cone beam scanners. Dose measurements with a small Farmer-type ionization chamber and with 100 mm and 300 mm long pencil ionization chambers were performed free in air to characterize the cone beam. According to the most common dose metric in CT, namely CTDI, measurements were also performed in 150 mm and 350 mm long CT head and CT body dose phantoms with 100 mm and 300 mm long pencil ionization chambers, respectively. To explore effects that cannot be measured with ionization chambers, Monte Carlo (MC) simulations of the dose distribution in 150 mm, 350 mm and 700 mm long CT head and CT body phantoms were performed. To overcome inconsistencies in the definition of CTDI100 for the 160 mm wide cone beam CT scanner, doses were also expressed as the average absorbed dose within the pencil chamber (D?100). Measurements free in air revealed excellent correspondence between CTDI300air and D?100air, while CTDI100air substantially underestimates CTDI300air. Results of measurements in CT dose phantoms and corresponding MC simulations at centre and peripheral positions were weighted and revealed good agreement between CTDI300w, D?100w and CTDI600w, while CTDI100w substantially underestimates CTDI300w. D?100w provides a pragmatic metric for characterizing the dose of the 160 mm wide cone beam CT scanner. This quantity can be measured with the widely available 100 mm pencil ionization chamber within 150 mm long CT dose phantoms. CTDI300w measured in 350 mm long CT dose phantoms serves as an appropriate standard of reference for characterizing the dose of this CT scanner. A CT dose descriptor that is based on an integration length smaller than the actual beam width is preferably expressed as an (average) dose, such as D?100 for the 160 mm wide cone beam CT scanner, and not as CTDI100.

Geleijns, J; Artells, M Salvado; de Bruin, P W; Matter, R; Muramatsu, Y; McNitt-Gray, M F

2010-01-01

342

Computed tomography dose assessment for a 160 mm wide, 320 detector row, cone beam CT scanner.  

PubMed

Computed tomography (CT) dosimetry should be adapted to the rapid developments in CT technology. Recently a 160 mm wide, 320 detector row, cone beam CT scanner that challenges the existing Computed Tomography Dose Index (CTDI) dosimetry paradigm was introduced. The purpose of this study was to assess dosimetric characteristics of this cone beam scanner, to study the appropriateness of existing CT dose metrics and to suggest a pragmatic approach for CT dosimetry for cone beam scanners. Dose measurements with a small Farmer-type ionization chamber and with 100 mm and 300 mm long pencil ionization chambers were performed free in air to characterize the cone beam. According to the most common dose metric in CT, namely CTDI, measurements were also performed in 150 mm and 350 mm long CT head and CT body dose phantoms with 100 mm and 300 mm long pencil ionization chambers, respectively. To explore effects that cannot be measured with ionization chambers, Monte Carlo (MC) simulations of the dose distribution in 150 mm, 350 mm and 700 mm long CT head and CT body phantoms were performed. To overcome inconsistencies in the definition of CTDI100 for the 160 mm wide cone beam CT scanner, doses were also expressed as the average absorbed dose within the pencil chamber (D100). Measurements free in air revealed excellent correspondence between CTDI300air and D100air, while CTDI100air substantially underestimates CTDI300air. Results of measurements in CT dose phantoms and corresponding MC simulations at centre and peripheral positions were weighted and revealed good agreement between CTDI300w, D100w and CTDI600w, while CTDI100w substantially underestimates CTDI300w. D100w provides a pragmatic metric for characterizing the dose of the 160 mm wide cone beam CT scanner. This quantity can be measured with the widely available 100 mm pencil ionization chamber within 150 mm long CT dose phantoms. CTDI300w measured in 350 mm long CT dose phantoms serves as an appropriate standard of reference for characterizing the dose of this CT scanner. A CT dose descriptor that is based on an integration length smaller than the actual beam width is preferably expressed as an (average) dose, such as D100 for the 160 mm wide cone beam CT scanner, and not as CTDI100. PMID:19420423

Geleijns, J; Salvad Artells, M; de Bruin, P W; Matter, R; Muramatsu, Y; McNitt-Gray, M F

2009-05-06

343

Computed tomography dose assessment for a 160 mm wide, 320 detector row, cone beam CT scanner  

NASA Astrophysics Data System (ADS)

Computed tomography (CT) dosimetry should be adapted to the rapid developments in CT technology. Recently a 160 mm wide, 320 detector row, cone beam CT scanner that challenges the existing Computed Tomography Dose Index (CTDI) dosimetry paradigm was introduced. The purpose of this study was to assess dosimetric characteristics of this cone beam scanner, to study the appropriateness of existing CT dose metrics and to suggest a pragmatic approach for CT dosimetry for cone beam scanners. Dose measurements with a small Farmer-type ionization chamber and with 100 mm and 300 mm long pencil ionization chambers were performed free in air to characterize the cone beam. According to the most common dose metric in CT, namely CTDI, measurements were also performed in 150 mm and 350 mm long CT head and CT body dose phantoms with 100 mm and 300 mm long pencil ionization chambers, respectively. To explore effects that cannot be measured with ionization chambers, Monte Carlo (MC) simulations of the dose distribution in 150 mm, 350 mm and 700 mm long CT head and CT body phantoms were performed. To overcome inconsistencies in the definition of CTDI100 for the 160 mm wide cone beam CT scanner, doses were also expressed as the average absorbed dose within the pencil chamber (\\overline D _{100}). Measurements free in air revealed excellent correspondence between CTDI300air and \\overline D _{100air}, while CTDI100air substantially underestimates CTDI300air. Results of measurements in CT dose phantoms and corresponding MC simulations at centre and peripheral positions were weighted and revealed good agreement between CTDI300w, \\overline D _{100w} and CTDI600w, while CTDI100w substantially underestimates CTDI300w. \\overline D _{100w} provides a pragmatic metric for characterizing the dose of the 160 mm wide cone beam CT scanner. This quantity can be measured with the widely available 100 mm pencil ionization chamber within 150 mm long CT dose phantoms. CTDI300w measured in 350 mm long CT dose phantoms serves as an appropriate standard of reference for characterizing the dose of this CT scanner. A CT dose descriptor that is based on an integration length smaller than the actual beam width is preferably expressed as an (average) dose, such as \\overline D _{100} for the 160 mm wide cone beam CT scanner, and not as CTDI100.

Geleijns, J.; Salvad Artells, M.; de Bruin, P. W.; Mather, R.; Muramatsu, Y.; McNitt-Gray, M. F.

2009-05-01

344

The Herschel Multi-tiered Extragalactic Survey: SPIRE-mm photometric redshifts  

NASA Astrophysics Data System (ADS)

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?m 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 colour evolution with redshift, finding that the colours of mm sources are adequately described by a modified blackbody with constant optical depth ?= (?/nu0)?, where ?=+1.8 and ?0=c/100 ?m. 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 |?z|/(1 +z) = 0.16 (<|?z|>= 0.51). Including constraints from the radio-far-IR correlation, the accuracy is improved to |?z|/(1 +z) = 0.15 (<|?z|>= 0.45). We estimate the redshift distribution of mm-selected sources finding a significant excess at z > 3 when compared to 850 ?m 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-Rodrguez, N.; Cava, A.; Chanial, P.; Chapin, E.; Chapman, S.; Clements, D. L.; Conley, A.; Conversi, L.; Cooray, A.; Dowell, C. D.; Dunlop, J. S.; Dwek, E.; Eales, S.; Elbaz, D.; Farrah, D.; Franceschini, A.; Glenn, J.; Griffin, M.; Halpern, M.; Hatziminaoglou, E.; Ibar, E.; Isaak, K.; Lagache, G.; Levenson, L.; Lu, N.; Madden, S.; Maffei, B.; Mainetti, G.; Marchetti, L.; Marsden, G.; Morrison, G.; Mortier, A. M. J.; Nguyen, H. T.; O'Halloran, B.; Oliver, S. J.; Omont, A.; Page, M. J.; Panuzzo, P.; Papageorgiou, A.; Pearson, C. P.; Prez-Fournon, I.; Pohlen, M.; Rawlings, J. I.; Raymond, G.; Rigopoulou, D.; Rizzo, D.; Rodighiero, G.; Rowan-Robinson, M.; Schulz, B.; Scott, Douglas; Seymour, N.; Shupe, D. L.; Smith, A. J.; Stevens, J. A.; Symeonidis, M.; Trichas, M.; Tugwell, K. E.; Vaccari, M.; Valtchanov, I.; Vieira, J. D.; Viero, M. P.; Vigroux, L.; Wardlow, J.; Wang, L.; Wright, G.; Xu, C. K.; Zemcov, M.

2012-02-01

345

Conventional metrizamide myelography (MM) and computed tomographic metrizamide myelography (CTMM) in scoliosis: a comparative study  

SciTech Connect

A retrospective examination was performed to assess the accuracy of metrizamide myelography (MM) and computed tomographic metrizamide myelography (CTMM) in scoliosis. Of 81 consecutive scoliotic children studied by myelography, 30 had only MM while the remaining 51 had CTMM immediately afterward. CTMM added esential diagnostic information in 13 cases of dysraphism and 4 cases, both methods gave the same imformation. The outhors conclude that in patients with severe scoliosis, dysraphism, and scoliosis with localized neurological disturbances, CTMM should always be added to MM or be the only examination; while in idiopathic scoliosis with vague neurological disturbances a survey of the entire spine is essential, preferably with MM.

Pettersson, H.; Harwood-Nash, D.C.; Fitz, C.R.; Chuang, H.S.; Armstrong, E.

1982-01-01

346

CRCHD Principal Investigator: Campbell, Janis, Ph.D.  

Cancer.gov

CRCHD Principal Investigator: Campbell, Janis, Ph.D. Back to CRCHD Ongoing Research CNP Project Listing Janis Campbell, Ph.D. CNP Project Listing CNP Pilot Projects Project Investigator Biography Campbell, Janis, Ph.D. University of

347

PhET Simulations: Quantum Phenomena  

NSDL National Science Digital Library

This is a collection of simulations from the PhET project in Quantum and Modern Physics. The simulations cover a range of topics including the photoelectric effect, wave interference, lasers, blackbody radiation, tunneling, the Stern-Gerlach experiment, nuclear physics, and applications of quantum mechanics. Each simulation provides a user interface that allows learners to explore the physical systems. These resources are part of the PhET project that has created a large collection of research-validated physics, chemistry, and math simulations.

Project, Physics E.

2008-07-13

348

Teaching Physics Using PhET Simulations  

NASA Astrophysics Data System (ADS)

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 research1 and experiences using them in high school and college classes. On our website we have a more complete guide to using PhET sims in the classroom: phet.colorado.edu/teacher_ideas/classroom-use.php.

Wieman, C. E.; Adams, W. K.; Loeblein, P.; Perkins, K. K.

2010-04-01

349

Spermatozoa motility in the Persian sturgeon, Acipenser persicus: effects of pH, dilution rate, ions and osmolality.  

PubMed

Sperm motility is a prerequisite factor determining semen quality and fertilizing capacity. The effects of environmental factors including pH, cations and osmolality as well as the role of dilution rate on sperm motility parameters in Acipenser persicus were studied. The best pH and dilution rate for activation of spermatozoa were pH 8.0 and dilution ratio 1:50. Ionic factors can stimulate the initiation of sperm activation. The maximum percentage of motile sperm and total duration of sperm motility were observed in solutions containing 25 mM NaCl, 0.2 mM KCl, 3 mM CaSO4, 10 mM MgSO4 and sucrose with an osmolality of 50 mosmol kg(-1). The present study provides us with some basic knowledge about sturgeon spermatozoa biosensitivity to ionic and osmolality effects. A sensitivity of A. persicus sperm was observed after induction of activation of sperm motility in solution containing cations or sucrose with high osmolality. Concentrations more than 50 mM Na+, more than 1 mM K+, more than 3 mM Ca2+ and more than 10 mM Mg2+ had negative effects on sperm motility. Also, osmolality more than 100 mosmol kg(-1) had an inhibitory effect. It is clear that ions and osmolality stimulate the motility of spermatozoa by changes in the properties of the plasma membrane including its potential and its ionic conductance. The inhibitory role of high osmolality of the swimming medium (more than 100 mosmol kg(-1)) and insufficient osmolality of the seminal plasma to inhibit semen motility suggested that osmolality is not the principal factor preventing sperm motility in seminal fluid but that K+ is a major inhibitory factor of sperm motility in seminal plasma. PMID:15579600

Alavi, Sayyed Mohammad Hadi; Cosson, Jacky; Karami, Mahmoud; Amiri, Bagher Mojazi; Akhoundzadeh, Mohammd Ali

2004-12-01

350

Modelling the growth rate of Escherichia coli as a function of pH and lactic acid concentration.  

PubMed Central

The growth rate responses of Escherichia coli M23 (a nonpathogenic strain) to suboptimal pH and lactic acid concentration were determined. Growth rates were measured turbidimetrically at 20 degrees C in the range of pH 2.71 to 8.45. The total concentration of lactic acid was fixed at specific values, and the pH was varied by the addition of a strong acid (hydrochloric) or base (sodium hydroxide) to enable the determination of undissociated and dissociated lactic acid concentrations under each condition. In the absence of lactic acid, E. coli grew at pH 4.0 but not at pH 3.7 and was unable to grow in the presence of > or = 8.32 mM undissociated lactic acid. Growth rate was linearly related to hydrogen ion concentration in the absence of lactic acid. In the range 0 to 100 mM lactic acid, growth rate was also linearly related to undissociated lactic acid concentration. A mathematical model to describe these observations was developed based on a B?lehrdek-like model for the effects of water activity and temperature. This model was expanded to describe the effects of pH and lactic acid by the inclusion of novel terms for the inhibition due to the presence of hydrogen ions, undissociated lactic acid, and dissociated lactic acid species. Preliminary data obtained for 200 and 500 mM total lactic acid concentrations show that the response to very high lactic acid concentrations was less well described by the model. However, for 0 to 100 mM lactic acid, the model described well the qualitative and quantitative features of the response.

Presser, K A; Ratkowsky, D A; Ross, T

1997-01-01

351

pH modelling in fermentation broths  

Microsoft Academic Search

A model of broth pH has been established based upon the mineral requirements of the microorganism, the substrate consumption and the metabolites production. It has been tested on acetic acid, citric acid and yeast fermentations. It has then been used to predict the mineral composition of the feed for fedbatch growth of Saccharomyces cerevisiae.

M. N. Pons; L. Garrido-Sanchez; P. Dantigny; J. M. Engasser

1990-01-01

352

Ph.D. First Year Report  

Microsoft Academic Search

this document I will describe what I have studied this year, record some possibledirections of research that seem promising to me now, and collect togethersome useful references. The aim is to persuade the reader that my rst yearhas been well-spent, and that I now have the necessary skills and backgroundknowledge to attempt a Ph.D. project.

Joe Hurd

1999-01-01

353

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

354

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

355

pH & Rate of Enzymatic Reactions.  

ERIC Educational Resources Information Center

|A quantitative and inexpensive way to measure the rate of enzymatic reaction is provided. The effects of different pH levels on the reaction rate of an enzyme from yeast are investigated and the results graphed. Background information, a list of needed materials, directions for preparing solutions, procedure, and results and discussion are

Clariana, Roy B.

1991-01-01

356

Potassium and intracellular pH  

Microsoft Academic Search

Potassium and acid-base balance have long been known to be interrelated. Studies have shown, for example, that a reduction in body potassium stores often induces a sustained metabolic alkalosis [1, 2], while acute administration of either potassium or rubidium chloride results in a rapid fall in blood pH and blood bicarbonate concentration [3]. The vast majority of metabolic reactions, however,

Sheldon Adler; Donald S Fraley

1977-01-01

357

Ph.D. Education for the Nineties  

Microsoft Academic Search

The Ph.D. degree in Australia, established some three and a half decades ago, has become recognised internationally as of high professional standing. However, attitudinal deficiencies in individual graduates, first recognised in the Fensham Report, still need to be addressed. Serious consideration needs to be given to the introduction of relevant course?work within the degree programme to broaden the intellectual base

D. R. Stranks

1984-01-01

358

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

359

The Economic Contribution of PhDs  

ERIC Educational Resources Information Center

|This paper looks at what the value of a doctorate is, both to employers in particular and to society and the economy at large. Given the emphasis many universities and funding agencies/governments are putting upon the development of PhD programmes, this is an issue deserving attention. The paper tries to show how two separate but interrelated

Casey, Bernard H.

2009-01-01

360

Interdisciplinary Ph.D. Programming in Evaluation.  

ERIC Educational Resources Information Center

|Advocates and presents an illustrative structure for interdisciplinary Ph.D. programs in evaluation. Posits that the introduction of such programs will give prospective students options through which they can gain the knowledge, skills, and experience needed to conduct evaluations. Describes the interdisciplinary evaluation program at Western

Stufflebeam, Daniel L.

2001-01-01

361

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

362

Development of Controlled-Rolled 70 kgf/mm(2) and 80 kgf/mm(2) Class High Tensile Strength Steel Plate for Weld Structure.  

National Technical Information Service (NTIS)

To meet demands for higher strength steel plates for construcion machines with excellent cold formability and weldability, as-rolled HT70 steel plates (TS: 686 MPa) having a maximum thickness of 25.4 mm and as-rolled HT80 (TS: 784 MPa) steel plates of 12....

K. Amano O. Tanigawa C. Shiga T. Okumura

1989-01-01

363

GPS surveying with 1 mm precision using corrections for atmospheric slant path delay  

Microsoft Academic Search

Multipath and atmospheric effects can limit GPS surveying precision. We surveyed a 43 km baseline using large diameter choke ring antennas to reduce multipath and pointed radiometer and barometric data to correct for atmospheric slant delay. Based on 11 daily solutions, atmospheric slant delay corrections improved vertical precision to 1.2 mm rms and horizontal precision to sub-mm. Applications for high

Chris Alber; Randolph Ware; Christian Rocken; Fredrick Solheim

1997-01-01

364

Pioneering breakthroughs in implant monitor wafer cost reduction at 300 mm  

Microsoft Academic Search

The semiconductor industry has been full of news regarding the transition to 300 mm wafers. In 1998, SEMICONDUCTOR300 (SC300) was the first to demonstrate the capability to produce integrated products on 300 mm wafers. To meet the challenge of maintaining quality while simultaneously reducing cost and ramping SC300 into pilot manufacturing, the authors have investigated the use of an overlay

Jason S. Zeakes; Terry A. Breeden

1999-01-01

365

300 mm tool automation and its impact on fab design and OEE  

Microsoft Academic Search

The challenge to building fabs in the 300 mm era will be to maximize the productivity of capital. One road in this direction is to increase Overall Equipment Effectiveness (OEE). At this time the approach being taken to increasing OEE involves the redesign of tools to improve reliability, increase throughput, reduce footprint, etc. The onset of 300 mm, however, presents

Mitchell Weiss

1996-01-01

366

The association between spontaneous pyelonephritis and maturity-onset diabetes mellitus in male MM mice  

Microsoft Academic Search

Summary Blood glucose and glucose tolerance tests demonstrated that many male MM mice are diabetic. Serial urine sampling showed that the diabetes occurred only in mature MM males and consisted of a single self-limiting episode. Histological examination of the pancreas, together with measurements of body weight, glycosylated haemoglobin and plasma insulin, revealed that the diabetes was of the maturity- onset

D. M. Taylor; D. L. Neal; P. A. McBride

1987-01-01

367

Superpower generator of mm-waves driven by microsecond sheet beam  

Microsoft Academic Search

Results of experimental investigations of a powerful mm-band FEM-oscillator driven by a sheet electron beam are presented. For mode selection, a planar geometry Bragg resonator was used. Microsecond pulses at a wavelength of 4 mm and power of 200 MW corresponding to record energy per pulse of 200 J were generated. The possibility to increase the energy content of the

M. A. Agafonov; V. V. Arzhannikov; V. G. Ivanenko; P. V. Kalinin; S. A. Kuznetsov; S. L. Sinitsky; N. S. Ginzburg; N. Yu. Peskov

1997-01-01

368

Mars: Subsurface Properties from Observed Longitudinal Variation of the 3.5-mm Brightness Temperature.  

National Technical Information Service (NTIS)

Measurements at 3.5 mm of the disk-average brightness temperature of Mars during the 1978 opposition can be represented by T sub B (Mars, 3.5 mm, Jan/Feb 1978) = 198(+ or - 1) + 10(+ or - 2) cos (CML + 10(+ or - 6) K. (The errors cited are from the intern...

E. E. Epstein B. H. Andrew F. H. Briggs B. M. Jakosky F. D. Palluconi

1984-01-01

369

Application of QM/MM Methods in Theoretical Studies of Enzyme Catalysis  

NASA Astrophysics Data System (ADS)

The QM/MM methods enjoy considerable attention recently due to their successful application on various complex systems. This paper gives brief introduction of the development of QM/MM methods. Then we focus our attention to the most recent applications in studies of enzyme catalysis.

Wang, Xi-Jun; Dai, Cong-Ying; Zhang, Yuan-Li; Wei, Dong-Qing

2009-03-01

370

Product Improvement Test of Cartridges, 5.56-mm, Assembled with Steel Cartridge Cases.  

National Technical Information Service (NTIS)

The purpose of the test was to determine suitability of the 5.56-mm steel-cased cartridges to replace standard brass-cased cartridges, and to determine the physical and technical characteristics of the 5.56-mm steel-cased cartridges. Specific test phases ...

L. J. Regan M. L. Kuczinski

1970-01-01

371

Oceanographic Office Evaluation of a Variable Magnification 70mm Roll Film Stereoscopic Viewer.  

National Technical Information Service (NTIS)

The report summarizes an operational evaluation of a standard model Zoom-70 stereoscope with a 70 mm. roll film scanning stage attachment. The function of the Zoom-70 stereoscope is to provide capability for viewing 70 mm. film stereo pairs at magnificati...

R. F. Gettys

1964-01-01

372

Use of the 25 mm flanged esophageal Z stent for malignant dysphagia: a prospective multicenter trial  

Microsoft Academic Search

Background: An initial multicenter study using a 21 mm flanged esophageal Z stent demonstrated excellent palliation but an 11% immediate complication rate at placement and a 27% migration rate at 1 month. This North American multicenter trial prospectively studied a 25 mm flanged Z stent to define its palliative ability and whether the increased diameter affected placement or migration problems.

Richard A. Kozarek; Shirley Raltz; Norman Marcon; Paul Kortan; Gregory Haber; Charles Lightdale; Peter Stevens; Glen Lehman; Douglas Rex; Stanley Benjamin; David Fleischer; Roshan Bashir; Steven Fry; Irving Waxman; Jay Benson; John Polio

1997-01-01

373

Ion-implanted silicon detectors processed on a 100 mm wafer  

Microsoft Academic Search

A planar process for manufacturing large silicon detectors on a 100 mm wafer has been developed. Several oxidation and annealing temperatures were studied in order to optimize detector performance. A strip detector with an active area of 32 58 mm2 together with various single detector diodes were processed and tested. The 1280 strip detector with 25 mum strip and

Iiro Hietanen; Jukka Lindgren; Risto Orava; Tuure Tuuva; Richard Brenner; Mikael Andersson; Kari Leinonen; Hannu Ronkainen

1991-01-01

374

Chemical Characterization of the Pyrotechnically Disseminated 66MM Red Phosphorous Smoke Screening IR, Vehicle Launched Grenade.  

National Technical Information Service (NTIS)

The United States Marine Corps established a new program, the 66mm Smoke Screening IR, Vehicle Launched MK1 MODO, for the redesign of the previously fielded 66mm M76 grenade. Although the M76 grenades provided effective screening in the visual and thermal...

C. L. Crouse D. A. McCaskey E. A. Davis K. L. Matson M. V. Haley

2008-01-01

375

Evaluation of a 254-mm Minimum Length Limit on Crappies in Delaware Reservoir, Ohio  

Microsoft Academic Search

A 254-mm minimum length limit on black crappies Pomoxis nigromaculatus and white crappies P. annularus was evaluated during a 6-year trial (19911996) at Delaware Reservoir, Ohio. The primary objective of the length limit was to increase the size of crappies harvested without substantially reducing yield. Mean length at harvest increased up to 66 mm following implementation of the length limit.

R. Scott Hale; Marty E. Lundquist; Randy L. Miller; Raymond W. Petering

1999-01-01

376

Introduction to Adjoint Techniques and the MM5 Adjoint Modeling System.  

National Technical Information Service (NTIS)

Adjoint models are increasingly applied to many problems in meteorolog and oceanography. The adjoint model of MM5 is a tool which effectively computes the gradient (or a Gateau-derivative) of any MM5 forecast aspect with respect to the model's control var...

X. Zou F. Van den Berghe M. Pondeca Y. H. Kuo

1997-01-01

377

Tumor-selective modification of cellular microenvironment in vivo: effect of glucose infusion on the pH in normal and malignant rat tissues.  

PubMed

The pH distributions in transplanted neural (TV1A, BT1A) and hepatic (HV1A3) tumors and in brain and kidney of BDIX rats were analyzed as a function of serum glucose concentration (SGC), tumor size, and tissue architecture. Tissue damage during pH measurements in vivo could be minimized by the use of pH microelectrodes with tip diameters of less than or equal to 10 micrometers. In normoglycemic rats, the pH in TV1A tumors was only slightly lower than in brain or kidney. However, at 6 hr after the induction of hyperglycemia by continuous i.v. infusion of glucose, the average pH in TV1A tumors had fallen to 6.7 at an SGC of 27 mM and to 6.1 at an SGC of 50 mM. A similar glucose-mediated pH reduction was observed in BT1A and HV1A3 tumors. No significant increase in tissue acidity occurred in brain and kidney. The pH in tumors had reached its minimum at 2 hr after the onset of high-dose glucose infusion (SGC, 50 mM) and could be maintained at this level in hyperglycemic rats for at least 48 hr. In hyperglycemic hosts, an increased retention of acidic metabolites in the tumor tissue with decreasing vascular density was reflected by a tumor size (age)-dependent pH reduction and a higher degree of intratumoral pH variation. In partially necrotic tumors, pH values as low as 5.2 were recorded. Oral administration of NaHCO3 to tumor-bearing rats had no effect on the average pH in TV1A tumors. PMID:7060023

Jhde, E; Rajewsky, M F

1982-04-01

378

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

379

Corneal Optical Quality Following Sub 1.8 mm Micro-Incision Cataract Surgery vs. 2.2 mm Mini-Incision Coaxial Phacoemulsification  

PubMed Central

Purpose: To study and compare the effects of the micro-incision cataract surgery (MICS-sub 1.8 mm) and miniincision coaxial phacoemulsification (2.2 mm) on the optical quality of the cornea characterized in terms of corneal aberrations. Materials and Methods: Fifty eyes underwent MICS and 50 mini-incision phacoemulsification, by the same surgeon. Both types of cataract surgery were performed using low ultrasound power and through a clear corneal incision, placed on the steepest corneal meridian ranging from 1.6 to 1.8 in MICS (Group I) and from 2.12 to 2.3 mm in mini-incision coaxial phacoemulsification (Group II). Seidel and Zernike aberration coefficients and RMS values were obtained for a 6-mm pupil preoperatively and one month after surgery. Results: The corneal astigmatism did not show statistically significant changes in either of the two groups: (MICS: 0.73 0.63, 0.65 0.53 D, P = 0.25), (mini-incision phacoemulsification; 1.21 1.52, 1.00 1.19 D, P = 0.12). The total RMS remained unchanged after MICS (1.77 1.7, 1.65 1.3 ?m, P = 0.18) and mini-incision phacoemulsification (2.00 1.87, 2.09 1.8 ?m, P = 0.41). Statistically significant changes were found for coma (P = 0.004) and higher-order aberrations (P < 0.001), showing MICS significantly less changes in cornea. Conclusions: Both MICS and mini-incision phacoemulsification do not degrade the optical quality of the cornea. Both surgeries do not induce a modification of the corneal astigmatism, even in the axis. It seems that 2 mm is the limit around which no optical changes are induced by cataract surgery in the human cornea.

Alio, Jorge L.; Elkady, Bassam; Ortiz, Dolores

2010-01-01

380

An efficient method of measuring the 4 mm helmet output factor for the Gamma Knife  

NASA Astrophysics Data System (ADS)

It is essential to have accurate measurements of the 4 mm helmet output factor in the treatment of trigeminal neuralgia patients using the Gamma Knife. Because of the small collimator size and the sharp dose gradient at the beam focus, this measurement is generally tedious and difficult. We have developed an efficient method of measuring the 4 mm helmet output factor using regular radiographic films. The helmet output factor was measured by exposing a single Kodak XV film in the standard Leksell spherical phantom using the 18 mm helmet with 30-40 of its plug collimators replaced by the 4 mm plug collimators. The 4 mm helmet output factor was measured to be 0.876 0.009. This is in excellent agreement with our EGS4 Monte Carlo simulated value of 0.876 0.005. This helmet output factor value also agrees with more tedious TLD, diode and radiochromic film measurements that were each obtained using two separate measurements with the 18 mm helmet and the 4 mm helmet respectively. The 4 mm helmet output factor measured by the diode was 0.884 0.016, and the TLD measurement was 0.890 0.020. The radiochromic film measured value was 0.870 0.018. Because a single-exposure measurement was performed instead of a double-exposure measurement, most of the systematic errors that appeared in the double-exposure measurements due to experimental setup variations were cancelled out. Consequently, the 4 mm helmet output factor is more precisely determined by the single-exposure approach. Therefore, routine measurement and quality assurance of the 4 mm helmet output factor of the Gamma Knife could be efficiently carried out using the proposed single-exposure technique.

Ma, Lijun; Li, X. Allen; Yu, Cedric X.

2000-03-01

381

A comparison of the effects of intracellular and extracellular pH on contraction in isolated rat portal vein.  

PubMed

1. The effects of changes in extracellular and intracellular pH on spontaneous contractile activity in isolated rat portal vein have been investigated. 2. Small strips of portal vein were loaded with the pH-sensitive fluorophore carboxy-SNARF and intracellular pH (pHi) and contraction were measured simultaneously at 37 degrees C. The tissue was superfused with oxygenated, Hepes-buffered solutions at pH 7.4. Intracellular pH was altered by isosmotic substitution of weak acids or bases. External pH (pHo) was altered by addition of strong acid or base to the solution. 3. The mean resting value of pHi was 7.06 +/- 0.03 (n = 28). Alteration of pHi led to changes in spontaneous activity. Addition of butyrate (20 mM) reduced pHi by 0.18 +/- 0.01 pH units (n = 8). Decreasing pHi produced an early, brief increase in contractile activity followed by a longer lasting decrease or even abolition of contraction. 4. Addition of 20 mM trimethylamine or NH4Cl increased pHi by around 0.2 pH units and produced an early transient decrease in contractile activity followed by a later maintained increase, both in frequency and magnitude. Removal of base produced a rapid rebound decrease in pHi which was associated with a further transient increase in contractile activity followed by decreased activity. The effects of base on both pHi and contraction were concentration dependent over the range investigated (2.5-30 mM). 5. Alteration of pHo produced a change in pHi in the portal vein. The pHi change was rapid compared to other non-vascular cells (about 1 min to half-maximal response).(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8021835

Taggart, M; Austin, C; Wray, S

1994-03-01

382

Effect of pH on contractile state and transsarcolemmal Ca flux in cultured heart cells  

SciTech Connect

The mechanism of pH-induced changes in cardiac contractile state was investigated using spontaneously beating cultured chick embryo ventricular cells. Cells were equilibrated in HEPES-buffered medium at pH 7.4 and then exposed to pH 6.0, 7.4 or 8.8 medium. pH-induced changes in Ca uptake were insensitive to 1 ..mu..M verapamil but were sensitive to changes in Na gradient. pH 6.0 inhibited and pH 8.8 stimulated Na/sub i/-dependent Ca uptake. Replacement of Na in the efflux medium with choline during /sup 45/Ca efflux did not affect the pH-induced changes in Ca efflux, suggesting that pH alters Ca efflux via sarcolemmal Ca-ATPase. Intracellular alkalinization or acidification produced by NH/sub 4/Cl (20 mM) altered contractile state by +140% or -60%, respectively, but failed to alter significantly the /sup 45/Ca influx or efflux rates. The authors conclude that pH-induced alteration in contractile state is due in part to changes in transsarcolemmal Ca movement via Na/Ca exchange as well as sarcolemmal Ca pump activity. pH/sub i/-induced alteration in contractile state is due to changes in Ca movements within the cell and/or in Ca sensitivity of myofibrils.

Kim, D.; Smith, T.W.

1986-03-05

383

Evolution of pH during in-situ leaching in small concrete cavities  

SciTech Connect

Small amounts (0.4 cc) of neutral water placed in small cylindrical cavities (5 mm diameter) in concrete exposed to 100% relative humidity first developed a pH comparable to that of a saturated Ca(OH){sub 2} solution. The pH then increased over a period of days-weeks toward a higher terminal value. A micro pH electrode arrangement was used. This behavior was observed in samples of 12 different concrete mix designs, including some with pozzolanic additions. The average terminal cavity pH closely approached that of expressed pore water from the same concretes. A simplified mathematical model reproduced the experimentally observed behavior. The model assumed inward diffusional transport of the pH-determining species in the surrounding concrete pore solution. The experimental results were consistent with the model predictions when using diffusion parameters on the order of those previously reported for alkali cations in concrete. The cavity size, cavity water content, and exposure to atmospheric CO{sub 2} should be minimized when attempting to obtain cavity pH values approaching those of the surrounding pore water.

Saguees, A.A. [Univ. of South Florida, Tampa, FL (United States). Dept. of Civil and Environmental Engineering; Moreno, E.I. [Univ. of South Florida, Tampa, FL (United States). Dept. of Civil and Environmental Engineering]|[CINVESTAV Merida-Unit (Mexico); Andrade, C. [CSIC, Madrid (Spain). Inst. Eduardo Torroja de Ciencias de la Construccion

1997-11-01

384

A miniature fiber optic pH sensor for physiological use.  

PubMed

A flexible 0.4-mm-dia pH probe potentially suitable for physiological use has been developed. It is based on the concept of utilizing two single plastic fiber optic strands to illuminate and remotely sense the color change of a dye indicator contained within an acutely implanted sealed cellulosic hollow fiber permeable to hydrogen ions. A supporting electronic module provides tungsten filament illumination, light sensing with a photodiode/operational amplifier, analog and digital circuitry to provide appropriate signal averaging and processing, and a mechanical assembly to enable the optical density measurements to be made both at 560 nm and, for normalization purposes, in the red. Over the physiological pH range from 7.0 to 7.4, the fiber optic probe agrees with a standard glass pH electrode to within 0.01 pH units in buffer solutions, to within 0.017 pH units in heparinized dog blood in vitro, and it has performed successfully while implanted in the jugular vein of a sheep. PMID:7412236

Goldstein, S R; Peterson, J I; Fitzgerald, R V

1980-05-01

385

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

PubMed

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. PMID:2478474

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

1989-11-01

386

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.

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

1987-01-01

387

The effect of ooplasmic pH regulation on the formation of yolk spheres in the telotrophic ovariole of Dysdercus intermedius  

Microsoft Academic Search

Vitellogenic oocytes of Dysdercus intermedius (Heteroptera: Pyrrhocoridae) were treated with the proton ionophore monensin in order to load the ooplasm with protons along the electrochemical gradient. Additionally, changes in the ooplasmic pH (?pHOOC) were recorded during exposure the oocytes to potassium-free medium (K+MED=0mM; choline for K+) or sodium-free medium (Na+MED=0mM; 40mM of choline for 40mM of Na+). The following observations

Frank Dittmann

1997-01-01

388

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

Pger, Csilla; Vargov, Andrea; Takcsi-Nagy, Anna; Drnyei, gnes; Kilr, Ferenc

2012-10-22

389

Characterization of a recombinant flocculent Saccharomyces cerevisiae strain that co-ferments glucose and xylose: II. influence of pH and acetic acid on ethanol production.  

PubMed

The inhibitory effects of pH and acetic acid on the co-fermentation of glucose and xylose in complex medium by recombinant flocculent Saccharomyces cerevisiae MA-R4 were evaluated. In the absence of acetic acid, the fermentation performance of strain MA-R4 was similar between pH?4.0-6.0, but was negatively affected at pH?2.5. The addition of acetic acid to batch cultures resulted in negligible inhibition of several fermentation parameters at pH?6.0, whereas the interactive inhibition of pH and acetic acid on the maximum cell and ethanol concentrations, and rates of sugar consumption and ethanol production were observed at pH levels below 5.4. The inhibitory effect of acetic acid was particularly marked for the consumption rate of xylose, as compared with that of glucose. With increasing initial acetic acid concentration, the ethanol yield slightly increased at pH?5.4 and 6.0, but decreased at pH values lower than 4.7. Notably, ethanol production was nearly completely inhibited under low pH (4.0) and high acetic acid (150-200mM) conditions. Together, these results indicate that the inhibitory effects of acetic acid and pH on ethanol fermentation by MA-R4 are highly synergistic, although the inhibition can be reduced by increasing the medium pH. PMID:23076570

Matsushika, Akinori; Sawayama, Shigeki

2012-10-18

390

CALCULATION OF pKa IN PROTEINS WITH THE MICROENVIRONMENT MODULATED-SCREENED COULOMB POTENTIAL (MM-SCP)  

PubMed Central

The MM-SCP has been applied to predict pKa values of titratable residues in wild type and mutants of staphylococcal nuclease (SNase). The calculations were based on crystal structures made available by the Garcia-Moreno Laboratory. In the mutants, mostly deeply buried hydrophobic residues were replaced with ionizable residues, and thus their pKa values could be measured and calculated using various methods. The data set used here consisted of a set of WT SNase for which His pKa at several ionic strengths had been measured, a set of mutants for which measured pKa were available and a set of 11 mutants for which the measured pKa were not known at the time of calculation. For this latter set, blind predictions were submitted to the protein pKa cooperative, 2009 workshop at Telluride, where the results of the blind predictions were discussed (the RMSD of the submitted set was 1.10 pH units). The calculations on the structures with known pKa indicated that in addition to weaknesses of the method, structural issues were observed that led to larger errors (>1) in pKa predictions. For example, different crystallography conditions or steric clashes can lead to differences in the local environment around the titratable residue, which can produce large differences in the calculated pKa. To gain further insight into the reliability of the MM-SCP, pKa of an extended set of 54 proteins belonging to several structural classes were carried out. Here some initial results from this study are reported to help place the SNase results in the appropriate context.

Shan, Jufang; Mehler, Ernest L.

2011-01-01

391

The reaction of PhSR(R = Fc or Ph) with Ru 3(CO) 12  

Microsoft Academic Search

The reaction of SPh2 with Ru3(CO)12 affords (?-SR)(?-?1; ?6-C6H5)Ru3(CO)8(Ru?Ru), R = Ph; 7 in 70% yield. Compound 7 results from S?Ph cleavage and no products of orthometallation reactions are observed. Similarly, SFcPh (6) and Ru3(CO)12 afford 8 (R = Fc) in good yield in addition to smaller amounts of (?-SFc)4Ru3(CO)7 (3Ru?Ru)2CHCl3 (9) and (?4-S)(?-SFc)6Ru4(CO)8 (10). Crystals of 6 are orthorhombic,

William R. Cullen; Steven J. Rettig; Tu Cai Zheng

1995-01-01

392

Regulation of intracellular pH by bovine intervertebral disc cells.  

PubMed

Extracellular acidity is an important determinant of intervertebral disc matrix turnover, possibly exerting effects through changes of intracellular pH (pHi). There is, however, little information concerning the ways in which these cells regulate their pHi. Fluorimetric techniques have been used in the present study to measure pH in isolated intervertebral disc cells, and to characterise the membrane transport pathways by which it is regulated. Nucleus pulposus cells were obtained from bovine intervertebral discs by standard enzymatic digestion techniques, and loaded with the PH-sensitive fluoroprobe BCECF. Resting pHi was approximately 6.7 for cells suspended in either HEPES buffered (HBS) or CO2/HCO3--buffered (BBS) media. Intrinsic buffering capacity was approximately 19 mM pH unit(-1) in HBS and was increased when cells were suspended in BBS. A combination of ion substitution and inhibitor studies for cells at steady-state pH or acidified by exposure to NH4Cl revealed that in HBS Na+ x H+ exchange and an H+-ATPase extrude acid from these cells. Only one of these two systems, the Na+ x H+ exchanger, exhibited a sensitivity to pH, identifying it as the regulator of pH under these conditions. In BBS, an additional pathway which was dependent on extracellular Na+, extracellular HCO3- and intracellular Cl- was detected. These properties are consistent with the four ion HCO3--dependent transporter, although the cation-rich, anion-poor extracellular matrix of the intervertebral disc means that such a pathway has only a marginal role in disc cell pHi regulation. PMID:10844402

Razaq, S; Urban, J P; Wilkins, R J

2000-01-01

393

pH recovery from intracellular alkalinization in Retzius neurones of the leech central nervous system.  

PubMed Central

1. Neutral-carrier pH-sensitive microelectrodes were used to investigate intracellular pH (pHi) recovery from alkalinization in leech Retzius neurones in Hepes- and in CO2-HCO3(-)-buffered solution. The Retzius neurones were alkaline loaded by the addition and subsequent removal of 16 mM acetate, by changing from 5% CO2-27 mM HCO3- to 2% CO2-11 mM HCO3- or by changing from CO2-HCO3(-)- to Hepes-buffered solution. 2. In Hepes-buffered solution (pH 7.4) the mean pHi was 7.29 +/- 0.11 and the mean membrane potential -44.7 +/- 5.9 mV (mean +/- S.D.; n = 83). 3. The rate of pHi recovery from alkalinization increased with decreasing pH of the bathing medium (pHb). pHi changed about 0.30 pH units for a pHb unit change. 4. A decrease of extracellular buffer concentration (Hepes concentration lowered from 20 to 5 mM) caused an acidification of extracellular and intracellular pH and an acceleration of pHi recovery from alkalinization. 5. A depolarization of the Retzius cell membrane-induced by increasing the K+ concentration of the bathing medium from 4 to 20 mM (delta Em = 16.5 +/- 5.5 mV) or from 4 to 40 mM (delta Em = 24.8 +/- 3.5 mV)--evoked a decrease of pHi and an acceleration of pHi recovery from alkalinization. 6. The H+ current blocker Zn2+ (0.5 mM) inhibited pHi recovery from alkalinization at resting membrane potential as well as during depolarization. The inhibition was more pronounced during depolarization. 7. In Cl(-)-free, CO2-HCO3(-)-buffered solution pHi recovery from an alkaline load by changing from 5% CO2-27 mM HCO3- to 2% CO2-11 mM HCO3- was slowed by 48-71%. The rate of pHi recovery from an alkaline load induced by changing from CO2-HCO3- to Hepes buffer was reduced by 33-56% in Cl(-)-free solution. The removal of external Cl- did not affect pHi recovery in Hepes-buffered solution. 8. The pHi recovery from alkalinization was DIDS-insensitive in CO2-HCO3(-)- as in Hepes-buffered solutions and was not slowed in the absence of external Na+. 9. It is concluded that in Retzius neurones pHi recovery from alkalinization is mediated by a passive voltage-dependent H+ influx along the electrochemical proton gradient. In the presence of CO2-HCO3- buffer a DIDS-insensitive Cl(-)-HCO3- exchanger additionally regulates pHi after an intracellular alkaline load. It cannot be excluded that intracellular processes (e.g. H+ release from organelles, metabolic H+ production) are also involved in pHi recovery from alkalinization.

Frey, G; Schlue, W R

1993-01-01

394

Contributions of pauli repulsions to the energetics and physical properties computed in QM/MM methods.  

PubMed

Conventional combined quantum mechanical/molecular mechanical (QM/MM) methods lack explicit treatment of Pauli repulsions between the quantum-mechanical and molecular-mechanical subsystems. Instead, classical Lennard-Jones (LJ) potentials between QM and MM nuclei are used to model electronic Pauli repulsion and long-range London dispersion, despite the fact that the latter two are inherently of quantum nature. Use of the simple LJ potential in QM/MM methods can reproduce minimal geometries and energies of many molecular clusters reasonably well, as compared to full QM calculations. However, we show here that the LJ potential cannot correctly describe subtle details of the electron density of the QM subsystem because of the neglect of Pauli repulsions between the QM and MM subsystems. The inaccurate electron density subsequently affects the calculation of electronic and magnetic properties of the QM subsystem. To explicitly consider Pauli interactions with QM/MM methods, we propose a method to use empirical effective potentials on the MM atoms. The test case of the binding energy and magnetic properties of a water dimer shows promising results for the general application of effective potentials to mimic Pauli repulsions in QM/MM calculations. 2013 Wiley Periodicals, Inc. PMID:23922165

Jin, Yingdi; Johnson, Erin R; Hu, Xiangqian; Yang, Weitao; Hu, Hao

2013-08-06

395

Creatine kinase-inhibiting monoclonal antibodies: preparation and characterization of porcine MM isoenzyme-specific antibodies.  

PubMed

Five monoclonal antibodies (CKM-B07, F12, D08, H09 and G01) against porcine creatine kinase (CK; EC 2.7.3.2) MM isoenzyme, which inhibit the enzymatic activity, were prepared. The hybridomas which produced monoclonal antibodies were screened by direct measurement of the inhibitory activity of their culture supernatant. Only two of them, however, were found to be measurable by an enzyme-linked immunosorbent assay with porcine CK-MM as an antigen. CKM-G01 inhibited 100% porcine CK-MM activity, while the others, 73-87%. On the other hand, only CKM-H09 inhibited porcine CK-BB activity (15%). CKM-F12 and D08 inhibited more than 50% CK-MB activity, whereas they did not inhibit CK-BB activity. The monoclonal antibodies were also tested for bovine, rabbit and human CK-MM. All the antibodies inhibited bovine and human CK-MM activity as well. In particular, CKM-G01 was found to exhibit more than 98% inhibition of all CK-MM activity tested, indicating that a common or very similar epitope which affects the activity is present on these enzymes. Admixing of CKM-B07 with other antibodies effected synergisms in inhibition, not only to porcine CK-MM activity but also to human CK-MM activity. A mixture of CK-B07 and G01 inhibited 100% human CK-MM activity, suggesting applicability of these monoclonal antibodies to clinical laboratory diagnosis. PMID:3173359

Suzuki, T; Tomita, K; Murachi, T

1988-06-01

396

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

397

A major water quality problem in smolt farms: combined effects of carbon dioxide, reduced pH and aluminium on Atlantic salmon ( Salmo salar L.) smolts: physiology and growth  

Microsoft Academic Search

Hatchery reared Atlantic salmon (Salmo salar L.) smolts (mean start weight 80 g) in soft freshwater were exposed to three levels of carbon dioxide partial pressure for 38 days (25 days for the high group) in an open flow system: 0.5 mm Hg (1.8 mg\\/l CO2; pH 6.6; control group), 2.7 mm Hg (9.3 mg\\/l CO2; pH 6.0; medium group)

Sveinung Fivelstad; Rune Waagb; Solveig F Zeitz; Anne Camilla Diesen Hosfeld; Anne Berit Olsen; Sigurd Stefansson

2003-01-01

398

Can the supermassive objects at the centers of galaxies be traversable wormholes? The first test of strong gravity for mm/sub-mm very long baseline interferometry facilities  

NASA Astrophysics Data System (ADS)

The near future mm/sub-mm very long baseline interferometry experiments are ambitious projects aiming at imaging the shadow of the supermassive black hole candidate at the center of the Milky Way and of the ones in nearby galaxies. An accurate observation of the shape of the shadow can potentially test the nature of these objects and verify if they are Kerr black holes, as predicted by general relativity. However, previous work on the subject has shown that the shadows produced in other spacetimes are very similar to the one of the Kerr background, suggesting that tests of strong gravity are not really possible with these facilities in the near future. In this work, I instead point out that it will be relatively easy to distinguish black holes from wormholes, topologically nontrivial structures of the spacetime that might have been formed in the early Universe and might connect our Universe with other universes.

Bambi, Cosimo

2013-05-01

399

GaN 20-mm diameter ingots grown from melt-solution by seeded technique  

SciTech Connect

In this paper, the authors describe the seeded growth of {approximately}20 mm diameter 15 mm long GaN ingots from the melt-solution. This is the first successful attempt to conduct growth of GaN boule-crystals. GaN ingots were grown from Ga-based melt in the temperature range of 800--1000 C at less than 2 atm ambient pressure. Growth was performed at {approximately}2 mm/hr growth rate. X-ray diffraction revealed polycrystalline structure of the ingots. Homoepitaxial GaN layers were deposited by HVPE technique on the substrates, which were fabricated from the grown GaN ingots.

Sukhoveyev, V.A.; Ivantsov, V.A.; Nikitina, I.P.; Babanin, A.I.; Polvakov, A.Y.; Govorkov, A.V.; Smirnov, N.B.; Mil'vidskii, M.G.; Dmitriev, V.A.

2000-07-01

400

PhET Simulation: States of Matter  

NSDL National Science Digital Library

This simulation helps learners visualize how molecules behave in solids, liquids, and gases. Add or remove heat and watch the motion of the molecules as they change phase. Push the pump and change the volume of matter in the closed container and watch the pressure gauge respond. More advanced students can compare the potential energy graphs for neon, argon, oxygen, and water -- which all have different interaction potential. Editor's Note: This particular activity would be well paired with the PhET "Gas Properties" simulation, which goes into more depth to explore the behavior of gas molecules in a closed container. Together, the simulations promote understanding of gas laws, states of matter, phase change, and kinetic theory. See Related Materials for a link to an exemplary lesson plan developed to accompany "States of Matter" simulation. This item is part of a larger collection of simulations developed by the Physics Education Technology project (PhET).

2011-07-18

401

Re-envisioning the PhD  

NSDL National Science Digital Library

This new site, sponsored by the Pew Charitable Trusts, is home to the Re-envisioning the PhD project, which is tasked with investigating change in doctoral education, in particular, helping to expand the career choices available to PhD students. In the Re-envisioning Project Resources section, visitors will find conference materials, recommendations from studies, summaries of interviews, a bibliography, career resources, and more. The Promising Practices section contains information on the different ways in which groups (universities, associations, organizations, and more) are responding to concerns about doctoral education. The other two main sections of the site, National/ International Resources and News and Updates contain links to even more resources, studies, current news, related projects, and more.

2001-01-01

402

Highlights From PhUn Week 2007  

NSDL National Science Digital Library

This is an article from The Physiologist. "More than 100 APS physiologists volunteered their time in reaching out to more than 3000 students last November during Physiology Understanding Week (PhUn Week), the APS member-based annual outreach program to local area K-12 schools (http://www.PhUnWeek.org). APS members partnered with more than 70 teachers and science educators from across the nation to develop engaging classroom or campus presentations for students at all grade levels, from day care through twelfth grades. The following vignettes are only a few samples of the excitement and fun generated by the focus on the physiology of health and exercise during the first week in November. All events with the primary APS member and lead teacher coordinators are listed in Table 1.".

2008-02-01

403

Comparison of higher-order aberrations after LASEK with a 6.0 mm ablation zone and a 6.5 mm ablation zone with blend zone  

Microsoft Academic Search

Purpose: To compare the higher-order aberrations (HOAs) after laser-assisted subepithelial keratectomy (LASEK) using a conventional optical zone and a larger zone with a blend zone.Setting: Department of Ophthalmology, Yonsei University College of Medicine, Seoul, Korea.Methods: In this prospective study, 19 patients with a manifest refraction of ?3.00 to ?8.25 diopters (D) were treated with LASEK using a conventional (6.0 mm)

Kyoung Yul Seo; Jae Bum Lee; Jimmy Jaeyoung Kang; Eun Suk Lee; Eung Kweon Kim

2004-01-01

404

Novel spin-coating technology for 248-nm/193-nm DUV lithography and low-k spin on dielectrics of 200-mm/300-mm wafers  

NASA Astrophysics Data System (ADS)

An alternative coating technology was developed for 248 nm/193 nm DUV lithography and low-k spin on dielectric (SOD) materials used in the interconnect area. This is a 300 mm enabling technology which overcomes turbulent flow limitations above 2000 rpm and it prevents 40 - 60% reduction on the process latitudes of evaporation-related variables, common to 300 mm conventional coaters. Our new coating technology is fully enclosed and it is capable of controlling the solvent concentration above the resist film dynamically in the gas phase. This feature allows a direct control of the evaporation mass transfer which determines the quality of the final resist profiles. Following process advantages are reported in this paper: (1) Demonstrated that final resist film thickness can be routinely varied by 4000 angstrom at a fixed drying spin speed, thus minimizing the impact of turbulence wall for 300 mm wafers. (2) Evaporation control allows wider range of useful thickness from a fixed viscosity material. (3) Latitudes of evaporation-related process variables is about 40% larger than that of a conventional coater. (4) Highly uniform films of 0.05% were obtained for 8800 angstrom target thickness with tighter wafer-wafer profile control because of the enclosed nature of the technology. (5) Dynamic evaporation control facilitates resist consumption minimization. Preliminary results indicate feasibility of a 0.4 cc process of record (POR) for a 200 mm substrate. (6) Lower COO due to demonstrated relative insensitivity to environmental variables, robust resist consumption minimization and superior process capabilities. (7) Improved planarization and gap fill properties for the new generation photoresist/low-k SOD materials deposited using this enclosed coating technology.

Gurer, Emir; Zhong, Tom X.; Lewellen, John W.; Lee, Ed C.

2000-06-01

405

Hua Zhang, PhD, Biologist  

Cancer.gov

Hua Zhang received his Bachelor of Medicine at Shanghai Second Medical University then a PhD in Microbiology and Immunology at the University of Arizona. Dr. Zhang has had a longstanding interest in the development of immunotherapies for cancer. He first postdoctoral fellowship was in the Department of Chemical Engineering at the University of Texas where he worked to develop scFv antibody derived biologics (Zhang et al, Cancer Research 1995) and then he subsequently studied with Dr.

406

Robert S. Kerbel, PhD  

Cancer.gov

After graduating from the University of Toronto, Dr. Robert Kerbel commenced graduate studies receiving a PhD in 1972; he then undertook postdoctoral training in London after which he started his independent research program in 1975 at Queen's University in Kingston, in the Cancer Research Laboratories, becoming its Director in 1981. In 1985 he was recruited to develop and direct a cancer biology research division at Mt.

407

Not Your Father's Ph.D.  

ERIC Educational Resources Information Center

|This article describes how the author, a devoted blogger, confronts his fear that his virtual life is damaging his career prospects in academe. As a new Ph.D. in religious studies, the author has every reason to believe he will find a tenure-track job. He has read the numbers and know that, on average, job candidates spend two to five years in

Withrow, Brandon G.

2008-01-01

408

PhET Simulation: Balloons & Buoyancy  

NSDL National Science Digital Library

This applet experiments with a helium balloon, a hot air balloon, or a rigid sphere filled with different gases. The user can discover what makes some balloons float and others sink. Teaching ideas and activities are included. The direct link to the simulation is given as a mirror URL. This is part of a larger collection developed by the Physics Education Technology project (PhET).

2008-07-15

409

Peter F. Carmeliet, MD, PhD  

Cancer.gov

Dr. Peter Carmeliet is Director of the VIB Vesalius Research Center, at the University of Leuven in Belgium. He graduated as Doctor in Medicine in 1984, and completed his Ph.D. in Medicine in 1989. After his return to Leuven in 1992, Dr. Carmeliet started his own research group with a focus on how blood vessels grow (angiogenesis) in health and disease. By developing transgenic mice lacking VEGF, he discovered that VEGF is a key player in angiogenesis. Dr.

410

PH 501 Philosophy of Christian Religion  

Microsoft Academic Search

Aristotle, Categories, Section I. Translated by E. M. Edghill; Provided by The Internet Classics Archive. Available online at http:\\/\\/classics.mit.edu\\/\\/Aristotle\\/categories.html Hasker, William, Metaphysics, Downers Grove, IVP, 1983. Helm, Paul, Objective Knowledge, Leicester: InterVarsity Press, 1987. - selections Ille, George, Hermeneutical Explorations of Agency as Prolegomena for a Theological Epistemology, PhD Thesis, Kings College, University of London, 2000). selections (provided in

George Ille

2003-01-01

411

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

412

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

PubMed

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 pH7.1-7.5, but was completely inhibited below pH6.2. 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 (2.40.3) 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. PMID:23500838

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

2013-02-17

413

Molecular aspects of bacterial pH sensing and homeostasis  

Microsoft Academic Search

Diverse mechanisms for pH sensing and cytoplasmic pH homeostasis enable most bacteria to tolerate or grow at external pH values that are outside the cytoplasmic pH range they must maintain for growth. The most extreme cases are exemplified by the extremophiles that inhabit environments with a pH of below 3 or above 11. Here, we describe how recent insights into

Terry A. Krulwich; George Sachs; Etana Padan

2011-01-01

414

The effects of intracellular pH changes on resting cytosolic calcium in voltage-clamped snail neurones  

PubMed Central

We have investigated the effects of changing intracellular pH on intracellular free calcium concentration ([Ca2+]i) in voltage-clamped neurones of the snail Helix aspersa. Intracellular pH (pHi) was measured using the fluorescent dye 8-hydroxypyrene-1,3,6-trisulphonic acid (HPTS) and changed using weak acids and weak bases. Changes in [Ca2+]i were recorded using either fura-2 or calcium-sensitive microelectrodes. Acidification of the neurones with 5 mM or 20 mM propionate (?0.2 or 0.3 pH units acidification, respectively) caused a small reduction in resting [Ca2+]i of 5 2 nM (n = 4) and 7 16 nM (n = 4), respectively. The removal of the 20 mM propionate after ?40 min superfusion resulted in an alkalinization of ?0.35 pH units and an accompanying rise in resting [Ca2+]i of 31 9 nM (n = 4, P < 0.05). The removal of 5 mM propionate did not significantly affect [Ca2+]i. Alkalinizations of ?0.2-0.4 pH units of Helix neurones induced by superfusion with 3 mM concentrations of the weak bases trimethylamine (TMA), ammonium chloride (NH4Cl) and procaine were accompanied by significant (P < 0.05) increases in resting [Ca2+]i of 42 4 nM (n = 26), 30 7 nM (n = 5) and 36 4 nM (n = 3), respectively. The effect of TMA (0.5-6 mM) on [Ca2+]i was dose dependent with an increase in [Ca2+]i during pHi increases of less than 0.1 pH units (0.5 mM TMA). Superfusion of neurones with zero calcium (1 mM EGTA) Ringer solution inhibited depolarization-induced calcium increases but not the calcium increase produced by the first exposure to TMA (3 mM). In the prolonged absence of extracellular calcium (?50 min) TMA-induced calcium rises were decreased by 64 10% compared to those seen in the presence of external calcium (P < 0.05). The calcium rise induced by TMA (3 mM) was reduced by 60 5% following a 10 min period of superfusion with caffeine (10 mM) to deplete the endoplasmic reticulum (ER) stores of calcium (P < 0.05). Cyclopiazonic acid (10-30 ?M CPA), an inhibitor of the ER calcium pump, inhibited the calcium rise produced by TMA (3 mM) and NH4Cl (3 mM) by 61 4% compared to controls (P < 0.05). These data are consistent with physiological intracellular alkaline shifts stimulating release of calcium, or inhibiting re-uptake of calcium by an intracellular store. The calcium increase was much reduced following application of caffeine, treatment with CPA or prolonged removal of external calcium. Hence the ER was likely to be the source of mobilized calcium.

Willoughby, Debbie; Thomas, Roger C; Schwiening, Christof J

2001-01-01

415

Nonlinear Dynamic Response Analysis of 115 mm Chemical Rocket Packing Impacts.  

National Technical Information Service (NTIS)

Nonlinear dynamic impact response analyses were performed on 115mm chemical rocket packing assemblies. Three different orientations of the packing assembly during impact with an unyielding surface were examined: impacts of the packing assembly bottom, sid...

S. E. Stewart P. A. Cox

1985-01-01

416

MEMS sensors for mm-range displacement measurements with sub-nm resolution  

NASA Astrophysics Data System (ADS)

It is challenging to provide contact measurements of travel in mm-range with nm/sub-nm resolution. It is even more complex to perform such measurements in static regime. In order to respond to the need for a simple, reliable and costeffective tool for contact travel measurements in mm-range with nm/sub-nm resolution, test MEMS sensor with sidewall embedded piezoresistors have been developed. The sensor comprises of two outer members having thickness of 270?m and two symmetrical sets of in-plane compliant elements: differential springs and displacement detection cantilevers, having thickness of 12?m. The MEMS devices have been bonded directly on low-noise amplifier PCB. For detailed characterization of the sensors in mm-travel range, two different experimental setups have been used. Measurements of 0.6 mm travel range at 1nm resolution have been demonstrated experimentally.

Stavrov, Vladimir T.; Todorov, Vencislav M.; Shulev, Assen A.; Hardalov, Chavdar M.

2013-05-01

417

50. OVERALL VIEW OF LOWER MAIN STREET, WITH M.M. WALKER ...  

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

50. OVERALL VIEW OF LOWER MAIN STREET, WITH M.M. WALKER COMPANY WAREHOUSE IN LEFT FOREGROUND AND THOMAS J. MULGREW COMPANY BUILDING IN RIGHT BACKGROUND. VIEW TO SOUTHEAST. - Dubuque Commercial & Industrial Buildings, Dubuque, Dubuque County, IA

418

The Basics of Outdoor Photography with a 35mm SLR Camera.  

ERIC Educational Resources Information Center

|Describes the functioning of a camera, defines terminology related to the camera, and explains camera settings. Highlights the Single Lens Reflex 35mm camera. Includes discussion of shutter speed, aperture, film speed, and lens types. (KS)|

Priest, Simon

1991-01-01

419

Reflection- and Emission-Properties of Natural and Artificial Materials at 3MM Wavelength.  

National Technical Information Service (NTIS)

A theoretical treatment of scattering geometry is followed by reflection coefficient measurements at 3mm wavelength on water, water with surface oil layer, cutting plates, sand, bricks, street surface, concrete, Eternit, lawn, humus, pine wood, tinted met...

R. Hofer

1974-01-01

420

TELEPHOTO VIEW (600MM LENS) OF SILVERTON, COLORADO, LOOKING NORTH NORTHEAST. ...  

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

TELEPHOTO VIEW (600MM LENS) OF SILVERTON, COLORADO, LOOKING NORTH NORTHEAST. NOTE DURANGO & SILVERTON NARROW GAUGE RAILROAD AT BOTTOM CENTER. - Shenandoah-Dives Mill, 135 County Road 2, Silverton, San Juan County, CO

421

Investigation to Improve Quality Evaluations of Primers and Propellant for 20mm Munitions.  

National Technical Information Service (NTIS)

To reduce the frequency of electrically initiated, 20mm munition hangfires (delayed ignitions), a joint Army/NASA investigation was conducted to recommend quality evaluation improvements for acceptance of both primers and gun propellant. This effort focus...

L. J. Bement C. Holmes J. McGrory M. L. Schimmel

1997-01-01

422

Same-source parallel implementation of the PSU/NCAR MM5  

SciTech Connect

The Pennsylvania State/National Center for Atmospheric Research Mesoscale Model is a limited-area model of atmospheric systems, now in its fifth generation, MM5. Designed and maintained for vector and shared-memory parallel architectures, the official version of MM5 does not run on message-passing distributed memory (DM) parallel computers. The authors describe a same-source parallel implementation of the PSU/NCAR MM5 using FLIC, the Fortran Loop and Index Converter. The resulting source is nearly line-for-line identical with the original source code. The result is an efficient distributed memory parallel option to MM5 that can be seamlessly integrated into the official version.

Michalakes, J.

1997-12-31

423

DMT-MM mediated functionalisation of the non-reducing end of glycosaminoglycans.  

PubMed

Efficient functionalisation of the non-reducing end of uronic acid derivatives and glycosaminoglycan-derived disaccharides using peptide coupling has been achieved, mediated by the water-soluble agent DMT-MM. PMID:17594020

Gemma, Emiliano; Hulme, Alison N; Jahnke, Astrid; Jin, Lan; Lyon, Malcolm; Mller, Ralf M; Uhrn, Dusan

2007-04-16

424

Clinical characteristics of papillary thyroid microcarcinoma less than or equal to 5mm on ultrasonography.  

PubMed

Management of papillary thyroid microcarcinoma sized ?5mm identified on ultrasonography is controversial. In this study, we evaluated the clinical characteristics of papillary thyroid microcarcinoma sized ?5mm on ultrasonography in comparison to those >5mm and sought to present rationales for optimal management in papillary thyroid microcarcinoma ?5mm. The medical records of 396 patients who underwent surgery for papillary thyroid carcinoma between 2009 and 2011 were retrospectively analyzed. The patients were grouped into A (?5mm, n=132) or B (>5mm, n=264) and the clinicopathologic characteristics of the patients were reviewed and compared between the two groups. Tumor capsular invasion (45.5 vs. 59.8%, p=0.007) and cervical lymph node metastasis (18.2 vs. 29.2%, p=0.018) were more frequent in group B. Nonetheless, group A presented lymph node metastasis in 42.3% of multifocal cases showing no difference to that of group B (41.5%, p=0.946) and also included five cases (3.8%) of lateral neck metastasis. Multifocality was the only predictive factor for lymph node metastasis in group A (p<0.001). Over half (55.3%) of the patients of group A were diagnosed with papillary carcinoma in private clinics; however, only 5.5% of these patients underwent assessment of lateral neck lymph nodes initially. In conclusion, higher risk of cervical lymph node metastasis should be considered in evaluation and surgical decision of papillary thyroid microcarcinoma ?5mm identified on ultrasonography with multifocality. Evaluation of the cervical lymph nodes including the lateral neck should not be overlooked when suspicious thyroid nodule suggesting malignancy sized ?5mm shows multifocal lesions. PMID:23873032

Lee, Hyoung Shin; Park, Hyo Sang; Kim, Sung Won; Choi, Gwan; Park, Hun-Su; Hong, Jong-Chul; Lee, Sung-Geun; Baek, Seon Mi; Lee, Kang Dae

2013-07-20

425

SSC 50 mm collider dipole cryostat single tube support post conceptual design and analysis  

SciTech Connect

This report describes the conceptual design for a support post whose function is identical to that of the current reentrant design, which requires very few modifications to surrounding cryostat components, is thermally equivalent to the current 50 mm support post, and is nearly equivalent structurally. The focus of this work is on a design aimed specifically at application in SSC 50 mm collider dipoles, however, the conceptual design presented here is applicable to other cryogenic systems.

Nicol, T.H.

1992-04-01

426

Biodegradation of diesel and heating oil by Acinetobacter calcoaceticus MM5: its possible applications on bioremediation  

Microsoft Academic Search

Twenty aerobic bacterial strains were isolated from altered heating oil. Among them the strain catalogued as MM5 and identified as Acinetobacter calcoaceticus is able to grow on hydrocarbon substrates. When strain MM5 was grown on heating oil, crude oil and tetradecane, increases of protein concentration and of caprilate-lipase and acetate-esterase enzymatic activities were observed in the culture filtrate, with a

Mercedes Marn; Ana Pedregosa; Santiago Ros; M. Luisa Ortiz; Fernando Laborda

1995-01-01

427

AMSU Millimeter-Wave Precipitation Retrievals Trained with MM5 Simulations: Sensitivity to Physical Assumptions  

Microsoft Academic Search

simulation system as a test-bed for precipitation retrieval development for satellite-borne millimeter-wave instruments. The sensitivity study was performed by comparing radiance histograms observed by satellite instruments (AMSU-A\\/B) over 122 diverse global storms with those simulated by variations of the MM5\\/RTM system for the same storm set. The radiances simulated by a baseline MM5\\/RTM model had earlier been shown to agree

Chinnawat Surussavadee; David H. Staelin

2006-01-01

428

Deep x-ray lithography fabrication of mm Wave cavities at the Advanced Photon Source  

Microsoft Academic Search

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

Song

1998-01-01

429

DEEP X-RAY LITHOGRAPHY FABRICATION OF mmWAVE CAVITIES AT THE ADVANCED PHOTON SOURCE  

Microsoft Academic Search

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 undulators, and mm-wave amplifiers. The microfabrica- tion 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

J. J. Song; Y. W. Kang; R. L. Kustom; A. Nassiri

430

Development of a 50mm dual Flip Chip Plastic Land Grid Array package for server applications  

Microsoft Academic Search

For many years, the Flip Chip Plastic Ball Grid Array (FC-PBGA) has been the preferred packaging solution for microprocessors and high performance ASICs. IBM has developed a dual chip Flip Chip Plastic Land Grid Array (FC- PLGA) package to support low and mid range server solutions. This organic 50 mm times 50 mm lead reduced package solution uses a 6-4-6

Sylvain Ouimet; Jon Casey; Kenneth Marston; Jennifer Muncy; John Corbin; Virendra Jadhav; Thomas Wassick; Isabelle Dpatie

2008-01-01

431

Passive mm-wave Sensor for InDoor and OutDoor Homeland Security Applications  

Microsoft Academic Search

Design and testing of the passive mm-wave sensor operating in 88-100 GHz range is reported. The scanning part of this sensor is based on a heterodyne configuration with a bandwidth up to 12 GHz and NF = 9-10 dB. It can receive like noise signals that are typical for passive mm-wave imaging. Depending on the antenna system the sensor can

B. Kapilevich; B. Litvak; M. Einat; O. Shotman

2007-01-01

432

An autonomous 16 mm3 solar-powered node for distributed wireless sensor networks  

Microsoft Academic Search

A 16 mm3 autonomous solar-powered sensor node with bidirectional optical communication for distributed sensor networks has been demonstrated. The device digitizes integrated sensor signals and transmits\\/receives data over a free-space optical link. The system consists of three die - a 0.25 ?m CMOS ASIC, a 2.6 mm2 SOI solar cell array, and a micromachined four-quadrant corner-cube retroreflector (CCR), allowing it

Brett A. Warneke; Michael D. Scott; Brian S. Leibowitz; Lixia Zhou; Colby L. Bellew; J. Alex Chediakt; Joseph M. Kahn; Bernhard E. Boser; Kristofer S. J. Pister

2002-01-01

433

Mesoscale Modeling of Katabatic Winds over Greenland with the Polar MM5  

Microsoft Academic Search

Verification of two months, April and May 1997, of 48-h mesoscale model simulations of the atmospheric state around Greenland are presented. The simulations are performed with a modified version of The Pennsylvania State University-National Center for Atmospheric Research fifth-generation Mesoscale Model (MM5), referred to as the Polar MM5. Global atmospheric analyses as well as automatic weather station and instrumented aircraft

David H. Bromwich; John J. Cassano; Thomas Klein; Gunther Heinemann; Keith M. Hines; Konrad Steffen; Jason E. Box

2001-01-01

434

Multichannel wire gas electron multipliers with gaps between the electrodes of 1 and 3mm  

Microsoft Academic Search

Multi-channel wire gas electron multipliers (MWGEM) with gaps between the electrodes of 1 and 3mm were investigated. The chamber of the MWGEM was filled with pure commercial neon gas at pressure of 0.4 or 1.0 bar and irradiated by alpha-particles (Pu-239) or beta-particles (Ni-63). The following maximal coefficients of electrons proportional multiplication have been obtained: 6 \\\\times 10^3 (alpha, d=3mm,

B. M. Ovchinnikov; V. V. Parusov; Yu. B. Ovchinnikov

2010-01-01

435

Refolding of SDS and Thermally Denatured MM-Creatine Kinase Using Cyclodextrins  

Microsoft Academic Search

We have tried to refold thermally-denatured MM-CK using detergent and cyclodextrins as protein folding assistants. This procedure, named artificial chaperone-assisted refolding, has been extensively tested to refold carbonic anhydrase B. Here, we describe a study which shows that this procedure can be applied to refold a dimeric multidomain protein : MM-creatine kinase. The pair SDS\\/hydroxy-propyl ?-cyclodextrin was used in this

Fabienne Couthon; Eric Clottes; Christian Vial

1996-01-01

436

Co-Channel Interference Analysis of Point to Point mm-Wave Radio Links  

Microsoft Academic Search

Point to point mm-wave radio links are being increasingly deployed because of the expansion of commercial wireless services. Providers of wireless services continue to demand systems with higher data rate and higher carrier frequency. In order to fulfill the demand unlicensed mm-wave bands have been investigated for fixed point-to-point outdoor radio ap- plications. An analytical method is developed in this

Mingdong Xu; Peter Nuechter

2006-01-01

437

GaInAs/AlInAs superlattice oscillators for optical to mm-wave conversion  

NASA Astrophysics Data System (ADS)

A simple optical to mm-wave conversion device is reported. It is based upon a GaInAs/AlInAs superlattice designed to produce mm-wave generation through the miniband negative conductance. It is driven by a light signal modulated near the oscillator fundamental frequency in order to obtain optical injection locking. The present paper stresses different material and non-linear transport properties necessary to optimise such devices at optical communications wavelengths.

Palmier, J. F.; Minot, C.; Le Person, H.; Harmand, J. C.; Tanguy, D.; Penard, E.

1998-07-01

438

Polar MM5 Simulations of the Winter Climate of the Laurentide Ice Sheet at the LGM  

Microsoft Academic Search

Optimized regional climate simulations are conducted using the Polar MM5, a version of the fifth-generation Pennsylvania State University-NCAR Mesoscale Model (MM5), with a 60-km horizontal resolution domain over North America during the Last Glacial Maximum (LGM, 21 000 calendar years ago), when much of the continent was covered by the Laurentide Ice Sheet (LIS). The objective is to describe the

David H. Bromwich; E. Richard Toracinta; Helin Wei; Robert J. Oglesby; James L. Fastook; Terence J. Hughes

2004-01-01

439

Polar MM5 Simulations of the Winter Climate of the Laurentide Ice Sheet at the LGM  

Microsoft Academic Search

Optimized regional climate simulations are conducted using the Polar MM5, a version of the fifth-generation Pennsylvania State University NCAR Mesoscale Model (MM5), with a 60-km horizontal resolution domain over North America during the Last Glacial Maximum (LGM, 21000 calendar years ago), when much of the continent was covered by the Laurentide Ice Sheet (LIS). The objective is to describe the

David H. Bromwich; E. Richard Toracinta; Helin Wei; Robert J. Oglesby; James L. Fastook; Terence J. Hughes

2004-01-01

440

Depth Penetration and Detection of pH Gradients in Biofilms by Two-Photon Excitation Microscopy  

PubMed Central

Deep microbial biofilms are a major problem in many industrial, environmental, and medical settings. Novel approaches are needed to understand the structure and metabolism of these biofilms. Two-photon excitation microscopy (TPE) and conventional confocal laser scanning microscopy (CLSM) were compared quantitatively for the ability to visualize bacteria within deep in vitro biofilms. pH gradients within these biofilms were determined by fluorescence lifetime imaging, together with TPE. A constant-depth film fermentor (CDFF) was inoculated for 8 h at 50 ml h?1 with a defined mixed culture of 10 species of bacteria grown in continuous culture. Biofilms of fixed depths were developed in the CDFF for 10 or 11 days. The microbial compositions of the biofilms were determined by using viable counts on selective and nonselective agar media; diverse mixed-culture biofilms developed, including aerobic, facultative, and anaerobic species. TPE was able to record images four times deeper than CLSM. Importantly, in contrast to CLSM images, TPE images recorded deep within the biofilm showed no loss of contrast. The pH within the biofilms was measured directly by means of fluorescence lifetime imaging; the fluorescence decay of carboxyfluorescein was correlated with biofilm pH and was used to construct a calibration curve. pH gradients were detectable, in both the lateral and axial directions, in steady-state biofilms. When biofilms were overlaid with 14 mM sucrose for 1 h, distinct pH gradients developed. Microcolonies with pH values of below pH 3.0 were visible, in some cases adjacent to areas with a much higher pH (>5.0). TPE allowed resolution of images at significantly greater depths (as deep as 140 ?m) than were possible with CLSM. Fluorescence lifetime imaging allowed the in situ, real-time imaging of pH and the detection of sharp gradients of pH within microbial biofilms.

Vroom, Jurrien M.; De Grauw, Kees J.; Gerritsen, Hans C.; Bradshaw, David J.; Marsh, Philip D.; Watson, G. Keith; Birmingham, John J.; Allison, Clive

1999-01-01

441

Assimilation of GMS-5 satellite winds using nudging method with MM5  

NASA Astrophysics Data System (ADS)

With the aid of Meteorological Information Composite and Processing System (MICAPS), satellite wind vectors derived from the Geostationary Meteorological Statellite-5 (GMS-5) and retrieved by National Satellite Meteorology Center of China (NSMC) can be obtained. Based on the nudging method built in the fifth-generation Mesoscale Model (MM5) of Pennsylvania State University and National Center for Atmospheric Research, a data preprocessor is developed to convert these satellite wind vectors to those with specified format required in MM5. To examine the data preprocessor and evaluate the impact of satellite winds from GMS-5 on MM5 simulations, a series of numerical experimental forecasts consisting of four typhoon cases in 2002 are designed and implemented. The results show that the preprocessor can process satellite winds smoothly and MM5 model runs successfully with a little extra computational load during ingesting these winds, and that assimilation of satellite winds by MM5 nudging method can obviously improve typhoon track forecast but contributes a little to typhoon intensity forecast. The impact of the satellite winds depends heavily upon whether the typhoon bogussing scheme in MM5 was turned on or not. The data preprocessor developed in this paper not only can treat GMS-5 satellite winds but also has capability with little modification to process derived winds from other geostationary satellites.

Gao, Shanhong; Wu, Zengmao; Yang, Bo

2006-09-01

442

Quantum mechanical/molecular mechanical (QM/MM) docking: an evaluation for known test systems  

NASA Astrophysics Data System (ADS)

A combined quantum mechanical/molecular mechanical (QM/MM) docking approach for the investigation of protein-inhibitor complexes is presented. Starting points for QM/MM optimizations are generated with AutoDock. The subsequent semiempirical AM1 QM/MM optimization of the complex obtained by the docking procedure gives a more detailed description of the binding mode and the electronic properties of the ligand. As we use a flexible protein environment in the QM/MM optimizations, we are able to simulate limited structural changes of the enzyme upon binding a ligand, even within a simple geometry optimization. The method was validated using a set of structurally known protein-inhibitor complexes, whose crystallographic data were taken from the Protein Data Bank. In addition to protein structures taken directly from complexes with the inhibitors, structures of uncomplexed HIV-1-protease and thrombin were also used successfully for QM/MM docking experiments. By comparing the resulting structures with those obtained using protein structures from protein-inhibitor complexes, we find that the method is able to simulate the effect of the induced fit when a simple optimization is adequate to reproduce the protein movement. Describing the ligand quantum mechanically gives a detailed view of its electronic properties, for example its polarization within the active site of the enzyme. This study suggests strongly that a QM/MM molecular dynamics approach will be able to simulate the induced fit in general cases.

Beierlein, Frank; Lanig, Harald; Schrer, Gudrun; Horn, Anselm H. C.; Clark, Timothy

443

Iridium oxide pH sensor for biomedical applications. Case urea-urease in real urine samples.  

PubMed

This work demonstrates the implementation of iridium oxide films (IROF) grown on silicon-based thin-film platinum microelectrodes, their utilization as a pH sensor, and their successful formatting into a urea pH sensor. In this context, Pt electrodes were fabricated on Silicon by using standard photolithography and lift-off procedures and IROF thin films were growth by a dynamic oxidation electrodeposition method (AEIROF). The AEIROF pH sensor reported showed a super-Nerstian (72.90.9mV/pH) response between pH 3 and 11, with residual standard deviation of both repeatability and reproducibility below 5%, and resolution of 0.03 pH units. For their application as urea pH sensors, AEIROF electrodes were reversibly modified with urease-coated magnetic microparticles (MP) using a magnet. The urea pH sensor provided fast detection of urea between 78?M and 20mM in saline solution, in sample volumes of just 50?L. The applicability to urea determination in real urine samples is discussed. PMID:22857994

Prats-Alfonso, Elisabet; Abad, Llibertat; Casa-Pastor, Nieves; Gonzalo-Ruiz, Javier; Baldrich, Eva

2012-07-21

444

Fiber-optic pH sensor based on sol-gel film immobilized with neutral red  

NASA Astrophysics Data System (ADS)

In this study, we developed a fiber-optic pH sensor based on a sol-gel film immobilized with neutral red (NR). A solgel film was prepared by mixing tetramethylorthosilicate (TMOS), trimethoxymethylsilane (MTMS), ethanol (EtOH), distilled water (H2O), and NR powder. Accordingly, the thin pH sol-gel film was fabricated through a sol-gel process with a dip-coating method. The thickness and diameter of the fabricated pH sol-gel film are 0.11 and 0.6 mm, respectively. We measured the optical absorbance and the light intensity with the spectra of reflected light, which change with the color variation of the pH sol-gel film in the fiber-optic sensing probe. From the experimental results, we demonstrated that the proposed fiber-optic pH sensor has good reversibility, reproducibility, and a fast response time, in which the optical properties of the NR-based pH sol-gel film change with the pH value.

Jeon, Dayeong; Yoo, Wook Jae; Seo, Jeong Ki; Shin, Sang Hun; Han, Ki-Tek; Kim, Seon Geun; Park, Jang-Yeon; Lee, Bongsoo

2013-03-01

445

The first use of the free selenimide Ph2Se=NH as a synthon; the synthesis and X-ray crystal structure of [Ph2SeNSePh2][BPh4].  

PubMed

Reaction of o-mesitylsulfonylhydroxylamine (MSH) with Ph(2)Se results in the [Ph(2)SeNH(2)](+) cation; low temperature deprotonation (LDA), bromination (NBS) and then treatment with Ph(2)Se-Na[BPh(4)] generates [Ph(2)SeNSePh(2)][BPh(4)], via the selenimides Ph(2)Se=NH and Ph(2)Se=NBr. PMID:18629400

Elsegood, Mark R J; Kelly, Paul F; Reid, Gillian; Staniland, Paul M

2008-06-10

446

Use of a Genetically Enhanced, Pediocin-Producing Starter Culture, Lactococcus lactis subsp. lactis MM217, To Control Listeria monocytogenes in Cheddar Cheese  

PubMed Central

Cheddar cheese was prepared with Lactococcus lactis subsp. lactis MM217, a starter culture which contains pMC117 coding for pediocin PA-1. About 75 liters of pasteurized milk (containing ca. 3.6% fat) was inoculated with strain MM217 (ca. 106 CFU per ml) and a mixture of three Listeria monocytogenes strains (ca. 103 CFU per ml). The viability of the pathogen and the activity of pediocin in the cheese were monitored at appropriate intervals throughout the manufacturing process and during ripening at 8C for 6 months. In control cheese made with the isogenic, non-pediocin-producing starter culture L. lactis subsp. lactis MM210, the counts of the pathogen increased to about 107 CFU per g after 2 weeks of ripening and then gradually decreased to about 103 CFU per g after 6 months. In the experimental cheese made with strain MM217, the counts of L. monocytogenes decreased to 102 CFU per g within 1 week of ripening and then decreased to about 10 CFU per g within 3 months. The average titer of pediocin in the experimental cheese decreased from approximately 64,000 arbitrary units (AU) per g after 1 day to 2,000 AU per g after 6 months. No pediocin activity (<200 AU per g) was detected in the control cheese. Also, the presence of pMC117 in strain MM217 did not alter the cheese-making quality of the starter culture, as the rates of acid production, the pH values, and the levels of moisture, NaCl, and fat of the control cheese and the experimental cheese were similar. Our data revealed that pediocin-producing starter cultures have significant potential for protecting natural cheese against L. monocytogenes.

Buyong, Nurliza; Kok, Jan; Luchansky, John B.

1998-01-01

447

New niobium complexes with alkynes. 6. Two compounds containing Nb sub 2 (PhCC(Ph)C(Ph)CPh) units joined in unorthodox ways  

Microsoft Academic Search

Two new compounds are described that contain the recently discovered Nb(PhCC(Ph)C(Ph)CPh) moiety. Compound 1, (NbOCl((PhC))(THF)) 2THF, contains centrosymmetric tetranuclear molecules in which the equivalent halves, Nb((PhC))Cl(THF)O, are joined solely by having the μ-O atom of each half form a strong donor bond to one of the Nb atoms of the other half. This compound crystallizes in space group P2\\/c

F. A. Cotton; Maoyu Shang

1990-01-01

448

Capillary electrophoretic separation of TNT and its transformation products.  

PubMed

2,4,6-Trinitrotoluene (TNT), 2-aminodinitrotoluene (2ADNT), 4-aminodinitrotoluene (4ADNT), and diamino-6-nitrotoluene (DA6NT) in a variety of matrices (including chemical, microbial, and plant extract) were successfully separated and quantified using micellar electrokinetic capillary electrophoresis (MEKC). The method used a buffer solution of 20 mM in borax, 50 mM in sodium dodecyl sulfate (SDS), and of pH 8.5. Voltage applied across the capillary was 20 kV and temperature was maintained at 25 degrees C. Compounds eluted within approximately 6-11 min and were identified by both their migration times and spectra. PMID:9384739

Pucik, L; Hughes, J

449

Effect of propionate toxicity on methanogen-enriched sludge, Methanobrevibacter smithii, and Methanospirillum hungatii at different pH values.  

PubMed Central

The effect of propionate toxicity at different pH values (6.5, 7.0, and 8.0) on methanogen-enriched sludge. Methanobrevibacter smithii, and Methanospirillum hungatii was studied. Organisms were grown in Balch medium 3 in Hungate tubes, and toxicity was characterized by a decrease in production of methane and in bacterial numbers. Propionate inhibited bacterial growth and cumulative methane production at concentrations as low as 20 mM. In the absence of propionate, the methanogen-enriched sludge and M. smithii showed better cumulative methane production at pH 6.5 and 7.0 than at pH 8.0. However, in the presence of propionate, these organisms showed better cumulative methane production at pH 8.0. M. hungatii differed in its behavior; the best values of cumulative methane production for this organism occurred at pH 7.0. Bacterial numbers reflected the microbial response to the presence of propionate. The highest counts of methanogenic bacteria were observed at pH 6.5 and 8.0. The numbers of methanogens were affected by the presence of propionate even at concentrations as low as 20 or 30 mM; at propionate concentrations above 80 mM, the methanogen count was affected by at least 2 orders of magnitude. Upon comparison of the responses of the pure cultures and the methanogen-enriched sludge to increasing propionate concentrations, it was found that the sensitivity of the pure cultures was similar to that of the methanogens in the sludge.

Barredo, M S; Evison, L M

1991-01-01

450

Bioelectricity production from food waste leachate using microbial fuel cells: Effect of NaCl and pH.  

PubMed

Microbial fuel cells are a promising technology for simultaneous treatment and energy recovery from food waste leachate. This study evaluates the effects of NaCl (0-150mM) and pH on the treatment of food waste leachate using microbial fuel cells. The food waste leachate amended with 100mM NaCl enabled the highest maximum power density (1000mW/m(3)) and lowest internal resistance (371?). Increasing the anodic pH gradually from acidic to alkaline conditions (pH 4-9) resulted in a gradual increase in maximum power density to 9956mW/m(3) and decrease in internal cell resistance to 35.3?. The coulombic efficiency obtained under acidic conditions was only 17.8%, but increased significantly to 60.0% and 63.4% in the neutral and alkaline pH's MFCs, respectively. Maintaining a narrow pH window (6.3-7.6) was essential for efficient bioelectricity production and COD removal using microbial fuel cells for the treatment of food waste leachate. PMID:24140849

Li, Xiao Min; Cheng, Ka Yu; Wong, Jonathan W C

2013-09-16

451

Biosorption of U(VI) by the green algae Chlorella vulgaris in dependence of pH value and cell activity  

Microsoft Academic Search

Biosorption of uranium(VI) by the green alga Chlorella vulgaris was studied at varying uranium concentrations from 5?M to 1mM, and in the environmentally relevant pH range of 4.4 to 7.0. Living cells bind in a 0.1mM uranium solution at pH 4.4 within 5min 14.35.5mgU\\/g dry biomass and dead cells 28.30.6mgU\\/g dry biomass which corresponds to 45% and 90% of total

M. Vogel; A. Gnther; A. Rossberg; B. Li; G. Bernhard; J. Raff

2010-01-01

452

QM/MM simulation of liquid water with an adaptive quantum region.  

PubMed

The simulation of complex chemical systems often requires a multi-level description, in which a region of special interest is treated using a computationally expensive quantum mechanical (QM) model while its environment is described by a faster, simpler molecular mechanical (MM) model. Furthermore, studying dynamic effects in solvated systems or bio-molecules requires a variable definition of the two regions, so that atoms or molecules can be dynamically re-assigned between the QM and MM descriptions during the course of the simulation. Such reassignments pose a problem for traditional QM/MM schemes by exacerbating the errors that stem from switching the model at the boundary. Here we show that stable, long adaptive simulations can be carried out using density functional theory with the BLYP exchange-correlation functional for the QM model and a flexible TIP3P force field for the MM model without requiring adjustments of either. Using a primary benchmark system of pure water, we investigate the convergence of the liquid structure with the size of the QM region, and demonstrate that by using a sufficiently large QM region (with radius 6 ?) it is possible to obtain radial and angular distributions that, in the QM region, match the results of fully quantum mechanical calculations with periodic boundary conditions, and, after a smooth transition, also agree with fully MM calculations in the MM region. The key ingredient is the accurate evaluation of forces in the QM subsystem which we achieve by including an extended buffer region in the QM calculations. We also show that our buffered-force QM/MM scheme is transferable by simulating the solvated Cl(-) ion. PMID:22089416

Bernstein, Noam; Vrnai, Csilla; Solt, Ivn; Winfield, Steven A; Payne, Mike C; Simon, Istvn; Fuxreiter, Mnika; Csnyi, Gbor

2011-11-16

453

Responses of gill mitochondria-rich cells in Mozambique tilapia exposed to acidic environments (pH 4.0) in combination with different salinities.  

PubMed

On exposure to hyposmotic acidic water, teleost fish suffer from decreases in blood osmolality and pH, and consequently activate osmoregulatory and acid-base regulatory mechanisms to restore disturbed ion and acid-base balances. In Mozambique tilapia Oreochromis mossambicus exposed to acidic (pH 4.0) or neutral (pH 7.4-7.7) freshwater in combination with 0mM or 50mM NaCl, we examined functional and morphological changes in gill mitochondria-rich (MR) cells. We assessed gene expression of Na(+)/H(+) exchanger-3 (NHE3), Na(+)/Cl(-) cotransporter (NCC), vacuolar-type H(+)-ATPase (V-ATPase) and Na(+)/HCO(3)(-) cotransporter-1 (NBC1) in the gills. The mRNA expression of NHE3 and NCC in tilapia gills were higher in acidic freshwater than in that supplemented with 50mM NaCl, while there was no significant difference in mRNA levels of V-ATPase and NBC1. In addition, immunocytochemical observations showed that apical-NHE3 MR cells were enlarged, and frequently formed multicellular complexes with developed deep apical openings in acidic freshwater with 0mM and 50mM NaCl. These findings suggest that gill MR cells respond to external salinity and pH treatments, by parallel manipulation of osmoregulatory and acid-base regulatory mechanisms. PMID:21147243

Furukawa, Fumiya; Watanabe, Soichi; Inokuchi, Mayu; Kaneko, Toyoji

2010-12-13

454

Recent Ph.D.s; Honors  

NASA Astrophysics Data System (ADS)

Recent Ph.D.s. Atmospheric Sciences. A study of atmospheric ammonia in coastal ecosystems utilizing relaxed eddy accumulation techniques and ion mobility spectrometry, LaToya Myles, Florida A&M University, December 2004, Advisor: Larry Robinson. Honors. Rana A. Fine has been awarded the 2005 Provost Award for Scholarly Activity, presented by the University of Miami. The award ``recognizes faculty for extraordinary research and scholarly pursuits.'' Charles David Keeling and Lonnie G. Thompson will receive the 2005 Tyler Prize for Environmental Achievement. The prize is given to individuals whose accomplishments in environmental science, policy, energy, and medicine confer great benefit upon mankind.

2005-04-01

455

PhET Simulation: Battery Voltage  

NSDL National Science Digital Library

This page contains a simple Java applet that gives users a look inside a battery to see how it works. It features a cross-sectional battery filled with blue spheres representing charges. As users change the voltage, little stick figures move the blue charges from one end of the battery to the other. A voltmeter displays the resulting battery voltage. Students must determine which side of the battery is positive or negative from the information at hand. This item is part of a larger collection of materials developed and maintained by the Physics Education Technology project (PhET) based on principles of physics education research.

2008-11-19

456

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 7.050.1 in the nominal absence of bicarbonate, and 7.150.1 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

457

The use of MM3 monoclonal antibodies for the early immunodiagnosis of ovine fascioliasis.  

PubMed

This study reports a new capture ELISA (MM3-SERO) for the serodiagnosis of sheep fascioliasis, based on the use of the monoclonal antibody (mAb) MM3. Like our previously reported indirect ELISA method, based on the use of a FPLC-purified fraction (fraction IV) of the Fasciola hepatica excretion/secretion antigens (ESAs), this new test was able to detect animals infected with very small numbers of metacercariae (5-40) and showed no cross-reaction with sera from sheep infected with other parasites, i.e., Moniezia spp., Cysticercus tenuicollis, and Dicrocoelium dendriticum. In contrast with these 2 methods, some sera (mainly those obtained from animals infected with D. dendriticum) showed high reactivities in indirect ELISA with whole F. hepatica ESAs used as control. Interestingly, the MM3-SERO ELISA has a better signal-to-noise ratio than the fraction-IV ELISA, thus allowing detection of seroconversion in infected sheep on average 1 wk earlier (3.2 +/- 0.4 wk postinfection [PI] for MM3-SERO ELISA vs. 4.2 +/- 0.9 wk PI for fraction IV ELISA). Moreover, the antibody response detected with MM3-SERO ELISA was more uniform, with seroconversion always occurring at 4 wk PI in sheep with 1-2 flukes and at 3 wk PI in sheep with more than 2 flukes. The MM3-SERO ELISA was also used to evaluate the kinetics of antibody response against MM3-recognized antigens in sera from sheep experimentally infected with F. hepatica and then treated with triclabendazole. Our results showed that antibody levels dropped by about 25% during the 4-wk observation period following the flukicide treatment, whereas they remained invariably high in all sheep left untreated. We conclude that the MM3-SERO ELISA is a 100% sensitive and 100% specific test for the early serodiagnosis of sheep fascioliasis. Preliminary studies in our laboratory seem to indicate that this method may also be useful for the determination of anti-F. hepatica antibodies in serum and milk of other ruminants. A commercial version of MM3-SERO is currently available from BIO X Diagnostics (La Jemelle, Belgium). PMID:17436943

Mezo, Mercedes; Gonzlez-Warleta, Marta; Ubeira, Florencio M

2007-02-01

458

Relations structurales entre U3O8 et quelques fluorures mixtes de formules M2M'3F11, MM'2F7 et MM'3F10  

NASA Astrophysics Data System (ADS)

U3O8 oxide, as well as M2M'3F11, MM'2F7 and MM'3F10 fluorides, with M = Rb, Tl, Cs, NH4 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'F7 or UO7 pentagonal bipyramids and M'F6 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 U3O8 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.

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

1983-01-01

459

Intracellular pH alterations induced by tacrine in a rat liver biliary epithelial cell line.  

PubMed

1. The effects of tacrine (THA) on intracellular pH (pH(i)) were examined in a rat liver biliary epithelial cell line (RLEC) in HEPES-buffered medium. pH(i) was recorded using the pH-sensitive fluoroprobe, carboxy-SNARF-1 (carboxy-seminaphtorhodafluor). 2. In the steady state, short-term exposures to THA resulted in alkalinization and re-acidification at 0.1 and 0.25 mM. Following a 24 h-treatment, no significant difference in pH(i) could be detected at 0.1 and 0.25 mM THA, whereas at 0.05 mM, pH(i) was slightly more acid (7.17+/-0. 02, n=16 versus 7.21+/-0.02, n=24 [control]). 3. In control and short-term treated cells, intracellular intrinsic buffering power (beta(i)) increased roughly linearly as pH(i) decreased. This dependence was not seen following long-term treatment. In all cases, beta(i) was increased by THA (by 1.6 to 3.5 fold). 4. Following an acid load (induced by 20 mM NH(4)Cl removal), pH(i) recovery in RLEC relied upon Na(+)/H(+) exchange. A short-term treatment (0.25 mM THA) did not affect total acid extrusion. In contrast, a 24 h-treatment with 0.05 mM THA reduced it (by approximately 36% at a pH(i) of 6.73) while at 0.25 mM, a large increase was detected (by approximately 109% at a pH(i) of 6.75). In Na(+)-free medium, THA (0. 25 mM) still induced an alkalinization in the steady state. Following an acid load, THA stimulated a Na(+)-independent acid efflux in a dose-dependent manner, inhibitable by alpha-cyano-4-hydroxy cinnamate (CHC, 4 mM) but not by quercetin (0. 125 mM). 6. In conclusion, this work demonstrates that THA affects pH(i) in RLEC, through a decrease in Na(+)/H(+) exchange and an increase in beta(i). Stimulation of a CHC-inhibitable, Na(+)-independent acid efflux is also detected. PMID:10588922

Lagadic-Gossmann, D; Rissel, M; Galisteo, M; Guillouzo, A

1999-12-01

460

Fourier transform infrared absorption spectroscopy characterization of gaseous atmospheric pressure plasmas with 2 mm spatial resolution  

NASA Astrophysics Data System (ADS)

This paper describes an optical setup built to record Fourier transform infrared (FTIR) absorption spectra in an atmospheric pressure plasma with a spatial resolution of 2 mm. The overall system consisted of three basic parts: (1) optical components located within the FTIR sample compartment, making it possible to define the size of the infrared beam (2 mm 2 mm over a path length of 50 mm) imaged at the site of the plasma by (2) an optical interface positioned between the spectrometer and the plasma reactor. Once through the plasma region, (3) a retro-reflector module, located behind the plasma reactor, redirected the infrared beam coincident to the incident path up to a 45 beamsplitter to reflect the beam toward a narrow-band mercury-cadmium-telluride detector. The antireflective plasma-coating experiments performed with ammonia and silane demonstrated that it was possible to quantify 42 and 2 ppm of these species in argon, respectively. In the case of ammonia, this was approximately three times less than this gas concentration typically used in plasma coating experiments while the silane limit of quantification was 35 times lower. Moreover, 70% of the incoming infrared radiation was focused within a 2 mm width at the site of the plasma, in reasonable agreement with the expected spatial resolution. The possibility of reaching this spatial resolution thus enabled us to measure the gaseous precursor consumption as a function of their residence time in the plasma.

Laroche, G.; Vallade, J.; Bazinette, R.; van Nijnatten, P.; Hernandez, E.; Hernandez, G.; Massines, F.

2012-10-01

461

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