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1

The development of meat tenderness is likely to be compartmentalised by ultimate pH.  

PubMed

Bull Musculus longissimus dorsi (n=63) were categorised into high (pH?6.2), intermediate (pH5.8-6.19) and low (?5.79) ultimate pH (pHu) and aged up to 28days post mortem at -1°C. High pHu samples were acceptably tender at 1day post mortem and significantly more tender than low pHu meat at all ageing timepoints (p<0.05). Rapid autolysis of ?-calpain in high pHu meat was linked with the more rapid degradation of titin, nebulin and filamin in this pHu group. Desmin degraded faster in low pHu meat and was concurrent with an increase of cathepsin B levels. The results from this study support the hypothesis that beef tenderisation is pHu compartmentalised with tenderness in high and low pHu meat characterised by variable rate of degradation of high and low molecular weight myofibrillar proteins during ageing, which are in turn regulated by ?-calpain and cathepsin B activities. PMID:24060535

Lomiwes, D; Farouk, M M; Wu, G; Young, O A

2013-08-29

2

Beef colour evolution as a function of ultimate pH  

Microsoft Academic Search

Colour in CIELAB space was assessed in 31 yearling entire male cattle from their reflectance spectra (400–700 nm) at six different times (0 min, 15 min, 5 h, 48 h, 6 days and 9 days). Cluster analysis applied to all the colour co-ordinates divided the samples into two groups according to their ultimate pH (pHu): pH<6.1 and pH?6.1. pH ranged

M Abril; M. M Campo; A Önenē; C Sańudo; P Albert??; A. I Negueruela

2001-01-01

3

The effects of the ultimate pH of meat on tenderness changes during ageing  

Microsoft Academic Search

A range of ultimate pH (pHu) values, from 5.4 to 7.2, was produced in the m. longissimus thoracicum et lumborum (LD) of 55 sheep by subcutaneous injections of adrenaline, or by injection and subsequent exercise.The rate constant of ageing for each of 47 animals was calculated from shear force measurements, taken at intervals for up to 5 days from the

A. Watanabe; C. C. Daly; C. E. Devine

1996-01-01

4

Breed differences in the biochemical determinism of ultimate pH in breast muscles of broiler chickens--a key role of AMP deaminase?  

PubMed

The biochemical determinism of ultimate pH (pHu) was studied in the pectoralis muscle of broiler chickens. Thirty birds of 3 genetic types (a fast-growing standard (FG), a slow-growing French "Label Rouge" (SG), and a heavy line type (HL)) were kept under conventional breeding methods until the usual marketing age (6, 12, and 6 wk for FG, SG, and HL birds, respectively). The birds were divided into 3 different antemortem treatment groups: minimum stress, shackling for a longer time (2 min), and heat stress (exposure to 35 degrees C for 3.5 h and shackling for 2 min before stunning). The birds were slaughtered on the same day. The pHu differed (P < 0.001) among the 3 genetic types, ranking as follows: FG (5.95+/-0.01) > HL (5.85+/-0.02) > SG (5.73+/-0.02). In SG and HL birds, pHu was strongly correlated with muscle glycogen content at slaughter (r = -0.74 and -0.82; P < 0.01 respectively), whereas this correlation was weak in FG birds. Regardless of genetic type, neither buffering capacity nor lactate accumulation significantly contributed to pHu variations (P > 0.05). The activity of adenosine monophosphate deaminase (AMPd) was significantly higher in FG chickens (0.98+/-0.31; P < 0.05) than in HL and SG birds (0.46+/-0.24 and 0.34+/-0.18, respectively). Significant correlations were found between AMPd activity, pHu, and glycolytic potential (GP) at slaughter (r = 0.34 and -.29; P < 0.01, respectively). Further research is needed to study in more detail the role of AMPd in the determinism of pHu, particularly in fast-growing broilers. PMID:15339023

El Rammouz, R; Berri, C; Le Bihan-Duval, E; Babilé, R; Fernandez, X

2004-08-01

5

Functional and rheological properties of proteins in frozen turkey breast meat with different ultimate pH.  

PubMed

Functional and rheological properties of proteins from frozen turkey breast meat with different ultimate pH at 24 h postmortem (pH(24)) have been studied. Sixteen breast fillets from Hybrid Tom turkeys were initially selected based on lightness (L*) values for each color group (pale, normal, and dark), with a total of 48 breast fillets. Further selection of 8 breast samples was made within each class of meat according to the pH(24). The average L* and pH values of the samples were within the following range: pale (L* >52; pH ?5.7), normal (46 < L* < 52; 5.9 < pH <6.1), and dark (L* <46; pH ?6.3), referred to as low, normal, and high pH meat, respectively. Ultimate pH did not cause major changes in the emulsifying and foaming properties of the extracted sarcoplasmic and myofibrillar proteins. An SDS-PAGE profile of proteins from low and normal pH meat was similar, which revealed that the extent of protein denaturation was the same. Low pH meat had the lowest water-holding capacity compared with normal and high pH meat as shown by the increase in cooking loss, which can be explained by factors other than protein denaturation. Gel strength analysis and folding test revealed that gel-forming ability was better for high pH meat compared with low and normal pH meat.Dynamic viscoelastic behavior showed that myosin denaturation temperature was independent of pH(24). Normal and high pH meat had similar hardness, springiness, and chewiness values as revealed by texture profile analysis. The results from this study indicate that high pH meat had similar or better functional properties than normal pH meat. Therefore, high pH meat is suitable for further processed products, whereas low pH meat may need additional treatment or ingredient formulations to improve its functionality. PMID:21489962

Chan, J T Y; Omana, D A; Betti, M

2011-05-01

6

The effects of early post-mortem pH and ultimate pH on level and amount of destructured zones in cooked cured hams  

Microsoft Academic Search

Effects of early (1h p.m. and 3h p.m.) and ultimate pH (24h p.m.) on level and amount of destructured zones in cooked cured hams were evaluated. In experiment 1, electrically stimulated (50V, 14Hz, 2×90s) and non-stimulated carcass halves, both in combination with two cooling procedures (2°C from 30min p.m. vs. 120min p.m.) resulted in 1.5–35.2g\\/kg destructured zones in silversides and

Gabriel Hugenschmidt; Ruedi Hadorn; Martin R. L. Scheeder; Paolo Silacci; Daniel Scherrer; Caspar Wenk

2010-01-01

7

Description and Analysis of the Sieges of Dien Bien Phu and Khe Sanh.  

National Technical Information Service (NTIS)

This paper includes a description and analysis of the sieges of Dien Bien Phu and Khe Sanh. It begins with a summary of General Vo Nguyen Giap. General Giap was the Vietminh commander at Dien Bien Phu and the North Vietnamese commander at Khe Sanh. Chapte...

R. L. Purcell

1986-01-01

8

Crystal structure of the Pseudomonas aeruginosa cytoplasmic heme binding protein, Apo-PhuS.  

PubMed

Iron is an essential element to all living organisms and is an important determinant of bacterial virulence. Bacteria have evolved specialized systems to sequester and transport iron from the environment or host. Pseudomonas aeruginosa, an opportunistic pathogen, uses two outer membrane receptor mediated systems (Phu and Has) to utilize host heme as a source of iron. PhuS is a 39kDa soluble cytoplasmic heme binding protein which interacts and transports heme from the inner membrane heme transporter to the cytoplasm where it is degraded by heme oxygenase thus releasing iron. PhuS is unique among other cytoplasmic heme transporter proteins owing to the presence of three histidines in the heme binding pocket which can potentially serve as heme ligands. Out of the three histidine residues on the heme binding helix, His 209 is conserved among heme trafficking proteins while His 210 and His 212 are unique to PhuS. Here we report the crystal structure of PhuS at 1.98Å resolution which shows a unique heme binding pocket and oligomeric structure compared to other known cytoplasmic heme transporter and accounts for some of the unusual biochemical properties of PhuS. PMID:23973453

Tripathi, Sarvind; O'Neill, Maura J; Wilks, Angela; Poulos, Thomas L

2013-07-27

9

A Model of Pulpit Conservation and Revitalization Using Community Participation of Phu-Thai People in Northeast Thailand  

Microsoft Academic Search

Problem statement: This thesis aimed to examine the following issues o f the pulpits: (1) background of the model and structure, (2) current conditions and problems of pulpit construction using participation of Phu-thai people in northeast Thailand and (3) model of conservation of revitalization of pulpits by participation of Phu-t hai people. Approach: Data were collected from documents and field

Bunkoet Laomi; Songkoon Chantachon; Niyom Wongphongkham

2009-01-01

10

Conservation needs of the dugong Dugong dugon in Cambodia and Phu Quoc, Vietnam  

Microsoft Academic Search

This research was conducted to assess the location of population groups and conservation issues affecting dugong Dugong dugon along the eastern Gulf of Thailand off Cambodia and Phu Quoc Island, Vietnam. Interviews in fishing communities in 2002 and 2004 along the Cambodian coast revealed that dugongs are sporadically found in fishing nets and their body parts are sold for a

Ellen Hines; Kanjana Adulyanukosol; Phay Somany; Leng Sam Ath; Nick Cox; Potchana Boonyanate; Nguyen Xuan Hoa

11

The Refugee Situation in Phu-Yen Province, Viet-Nam (Abridged Version).  

National Technical Information Service (NTIS)

The principal findings of a field study of the refugee situation in Phu-Yen Province, Viet-Nam, are summarized. Based upon interview data collected in mid-1966 from a 12% sample (1, 193 interviews with refugee heads-of-household), the report describes the...

A. T. Rambo J. M. Tinker J. D. LeNoir

1967-01-01

12

Characterization on mosaic glass found at Phu Khao Thong, southern area of Thailand  

NASA Astrophysics Data System (ADS)

Glasses in forms of ornament and decorative objects have been found in Thailand for several hundred years. The mosaic glass used in this work was only one piece that excavated at Phu Khao thong archaeological site in Ranong Province, southern area of Thailand. Micro-beam X-ray fluorescence spectroscopy (?-XRF) based on synchrotron radiation was firstly carried out to analyze its elemental composition and distribution. Scanning electron microscope coupled with energy dispersive X-ray fluorescence spectroscopy (SEM-EDS) and (PIXE) were also used to characterize the composition. The main composition of this mosaic glass sample found in Thailand was a lead-based silicate glass. The colorations were affected from transition metals, especially iron, copper and manganese. It was shown that although it look-liked the same, but the main composition was differ to that of Persia and South Asia, especially the lead content. However, it demonstrated the long distance trade or exchange network of the ancient time.

Won-in, K.; Thongkam, Y.; Dhanmanonda, W.; Tancharakorn, S.; Tanthanuch, W.; Kamwanna, T.; Thongleurm, C.; Dararutana, P.

2013-03-01

13

Membrane Transporters and Cytoplasmatic pH Regulation on Bovine Sertoli Cells  

Microsoft Academic Search

Sertoli cells are responsible for regulating a wide range of processes that lead to the differentiation of male germ cells\\u000a into spermatozoa. Cytoplasmic pH (pH\\u000a i\\u000a ) has been shown to be an important parameter in cell physiology, regulating namely cell metabolism and differentiation. However,\\u000a membrane transport mechanisms involved in pH\\u000a i\\u000a regulation mechanisms of Sertoli cells have not yet

P. F. Oliveira; M. Sousa; A. Barros; T. Moura; A. Rebelo da Costa

2009-01-01

14

The Ultimate Fizz  

ERIC Educational Resources Information Center

|Many recipes for elementary science activities suggest making carbon dioxide from baking soda and vinegar; however, they often do not give exact measurements of the ingredients. The author was able to turn this "drawback" into a plus by challenging her fifth-grade students to find the "ultimate fizz"--i.,e., "What amount of baking soda added to a…

Heckscher, Mary

2008-01-01

15

Time variations of the ionosphere at the northern tropical crest of ionization at Phu Thuy, Vietnam  

NASA Astrophysics Data System (ADS)

This study is the first which gives the climatology of the ionosphere at the northern tropical crest of ionization in the Asian sector. We use the data from Phu Thuy station, in Vietnam, through three solar cycles (20, 21 and 22), showing the complete morphology of ionosphere parameters by analyzing long term variation, solar cycle variation and geomagnetic activity effects, seasonal evolution and diurnal development. Ionospheric critical frequencies, foF2, foF1 and foE, evolve according to the 11-year sunspot cycle. Seasonal variations show that foF2 exhibits a semiannual pattern with maxima at equinox, and winter and equinoctial anomalies depending on the phases of the sunspot solar cycle. ?foF2 exhibits a semiannual variation during the minimum phase of the sunspot solar cycle 20 and the increasing and decreasing phases of solar cycle 20, 21 and 22. ?foF1 exhibits an annual variation during the maximum phase of solar cycles 20, 21 and 22. ?h'F2 shows a regular seasonal variation for the different solar cycles while ?h'F1 exhibits a large magnitude dispersion from one sunspot cycle to another. The long term variations consist in an increase of 1.0 MHz for foF2 and of 0.36 MHz for foF1. foE increases 0.53 MHz from solar cycle 20 to solar cycle 21 and then decreases -0.23 MHz during the decreasing phase of cycle 21. The diurnal variation of the critical frequency foF2 shows minima at 05:00 LT and maxima around 14:00 LT. foF1 and foE have a maximum around noon. The diurnal variation of h'F2 exhibits a maximum around noon. The main features of h'F1 are a minimum near noon and the maximum near midnight. Other minima and maxima occur in the morning, at about 04:00 or 05:00 LT and in the afternoon, at about 18:00 or 19:00 LT but they are markedly smaller. Only during the maximum phase of all sunspot solar cycles the maximum near 19:00 LT is more pronounced.

Pham Thi Thu, H.; Amory-Mazaudier, C.; Le Huy, M.

2011-01-01

16

Higgsometry from Ultimate LEP  

NASA Astrophysics Data System (ADS)

The bounds that could be set on the mass of the standard model Higgs boson from electroweak measurements (?l, Mw, ALR) and measurement of the top quark mass at LEP and the Tevatron are analysed. Significant bounds would be obtained (?MH/MH ~ 35%) for the Ultimate LEP configuration, with longitudinal polarization and high luminosity simultaneously available. URA no. 14-36 du CNRS, associée ą l'Ecole Normale Supérieure de Lyon et au Laboratoire d'Annecy-le-Vieux de Physique des Particules (IN2P3).

Blondel, A.; Renard, F. M.; Verzegnassi, C.

1991-10-01

17

“Quasi Ultimate” Technique  

Microsoft Academic Search

\\u000a In this chapter, a multi-level modulation\\/demodulation method based on a self-homodyne phase noise canceling scheme using\\u000a a pilot carrier is introduced as a “Quasi Ultimate” technique. The technique allows us to enjoy simultaneous constellation\\u000a observation and symbol error rate measurement even with multi-level modulation of high degree, such as 16-QAM or 64-QAM, by\\u000a relaxing the spectral linewidth requirements of the

Tetsuya Miyazaki

18

Ultimate Safe (US) Reactor  

SciTech Connect

The Ultimate Safe (US) Reactor is a reactor that eliminates the traditional safety concerns of nuclear fission reactors. The US reactor has an insignificant source term and no reasonable criticality accident. Furthermore, the negligible residual after-heat in the reactor renders its shutdown capability comparable or superior to conventional power sources. Fission products are continuously removed at the rate they are produced. The reactor is operated with no excess criticality, hence no criticality accident is reasonably possible. The reactor is controlled safely by its negative temperature coeffiient. The reactor maintains criticality by an internal breeding ratio that is trimmed to be exactly one. The US reactor requires a fluid fuel and on-line, continuous fuel processing. Molten salt fuel was selected for its low vapor pressure at high temperature; adequate solubility of uranium and thorium as fluorides; good compatibility with structural materials; absence of irradiation damage; high negative temperature coefficient and amply developed technology and experience.

Gat, U.; Daugherty, S.R.

1985-01-01

19

EFFECT OF MOTHER'S FEEDING, PHYSIOLOGICAL STATE, PARITY ORDER AND OFFSPRING'S AGE ON THEIR POST-MORTEM pH EVOLUTION OF LONGISSIMUS DORSI MUSCLE  

Microsoft Academic Search

The muscle pH evolution and its final value (pHu) h ave important influence on the keeping qualities of meat, as affecting proteins structures and water holding capacity. Thirty hybrid female rabbits of 15 weeks of age were randomly divided into three groups and fed with one of the three following diets: \\

20

Ultimate Realities: Deterministic and Evolutionary  

ERIC Educational Resources Information Center

|References to ultimate reality commonly turn up in the behavioral literature as references to determinism. However, this determinism is often difficult to interpret. There are different kinds of determinisms as well as different kinds of ultimate realities for a behaviorist to consider. To clarify some of the issues involved, the views of…

Moxley, Roy A.

2007-01-01

21

Ultimate Cognition ą la Gödel  

Microsoft Academic Search

All life is problem solving,'' said Popper. To deal with arbitrary problems in arbitrary environments, an ultimate cognitive agent should use its limited hardware in the ''best'' and ''most efficient'' possible way. Can we formally nail down this informal statement, and derive a mathematically rigorous blueprint of ultimate cognition? Yes, we can, using Kurt Godel's celebrated self-reference trick of 1931

Jürgen Schmidhuber

2009-01-01

22

Sintering densification and microstructural evolution of injection molding grade 17-4 PH stainless steel powder  

Microsoft Academic Search

Densification behavior is investigated by means of dilatometry for powder-injection-molded (PIM) and die-compacted 17-4 PH\\u000a stainless steel during sintering in pure H2 and H2 + N2. The corresponding microstructural evolution is examined by quenching in a vertical furnace at various stages of sintering.\\u000a The results show that in comparison with pure H2, the H2 + N2 atmosphere retards densification and

Yunxin Wu; Debby Blaine; Connie Schlaefer; Brian Marx; Randall M. German

2002-01-01

23

Equilibrium unfolding of A. niger RNase: pH dependence of chemical and thermal denaturation  

Microsoft Academic Search

Equilibrium unfolding of A. niger RNase with chemical denaturants, for example GuHCl and urea, and thermal unfolding have been studied as a function of pH\\u000a using fluorescence, far-UV, near-UV, and absorbance spectroscopy. Because of their ability to affect electrostatic interactions,\\u000a pH and chemical denaturants have a marked effect on the stability, structure, and function of many globular proteins. ANS\\u000a binding

Gundampati Ravi Kumar; Anurag Sharma; Moni Kumari; Medicherla V. Jagannadham; Mira Debnath

2011-01-01

24

Extracellular pH defense against lactic acid in untrained and trained altitude residents  

Microsoft Academic Search

The assumption that buffering at altitude is deteriorated by bicarbonate (bi) reduction was investigated. Extracellular pH\\u000a defense against lactic acidosis was estimated from changes (?) in lactic acid ([La]), [HCO3\\u000a ?], pH and PCO2 in plasma, which equilibrates with interstitial fluid. These quantities were measured in earlobe blood during and after incremental\\u000a bicycle exercise in 10 untrained (UT) and 11

D. Böning; J. Rojas; M. Serrato; O. Reyes; L. Coy; M. Mora

2008-01-01

25

Surface pH at the Basolateral Membrane of the Caecal Mucosa of Guinea Pig  

Microsoft Academic Search

.   Since the major mechanisms responsible for regulation of intracellular pH of enterocytes are located in the basolateral membrane,\\u000a respective effects may be expected on pH in the compartment near the basolateral membrane. A method was established to estimate\\u000a the pH at the basolateral membrane (pH\\u000a \\u000a b\\u000a \\u000a ) of isolated caecal epithelia of guinea pig using pH-sensitive fluorescein attached to

S. Kirschberger; R. Busche; W. von Engelhardt

1999-01-01

26

Is language the ultimate artefact?  

Microsoft Academic Search

Andy Clark has argued that language is “in many ways the ultimate artefact” (Clark, 1997, p. 218). Fuelling this conclusion is a view according to which the human brain is essentially no more than a pattern-completing device, while language is an external resource which is adaptively fitted to the human brain in such a way that it enables that brain

Michael Wheeler

2004-01-01

27

Ultimate Cost of Building Walls.  

ERIC Educational Resources Information Center

The need for economic analysis of building walls is discussed, and the factors influencing the ultimate cost of exterior walls are studied. The present worth method is used to analyze three types of exterior non-loadbearing panel or curtain walls. Anticipated costs are expressed in terms of their present value per square foot of wall area. The…

Grimm, Clayford T.; Gross, James G.

28

Process inherent, ultimately safe BWR  

SciTech Connect

A new type of boiling water reactor (BWR) with passive safety systems has been conceived - the process inherent, ultimately safe (PIUS) BWR. The reactor core and non-nuclear portion of the plant are similar to current BWR designs, but a special, prestressed concrete reactor vessel (PCRV) with unique internal design replaces most of the nuclear island. A natural circulation PIUS BWR with key components inside the PCRV is described. Forced circulation is an option. The reactor pressure, temperature, and thermal efficiencies match current BWRs.

Forsberg, C.W.

1985-11-01

29

Magnetic properties of ultimate torsatrons  

NASA Astrophysics Data System (ADS)

The nature and properties of the magnetic surface structure of a torsatron plasma confinement device with helical windings designed so as to eliminate the need for vertical compensation coils are investigated. The winding law necessary to produce a zero vertical field component in a toroidal helix is presented, and the vacuum magnetic properties of the ultimate torsatron are calculated numerically based on the modeling of the winding as many small straight segments of filamentary current. The general size and shape of the magnetic surfaces are found to depend on the number of field periods, the poloidal multiplicity and the aspect ratio, while the coil modulation principally determines the magnetic axis radial position. Means for the variation of magnetic properties through the use of small perturbation coils or the choice of the poloidal multiplicity and the number of field periods are indicated, and the effects of a finite conductor size are pointed out.

Kruckewitt, T. W.; Shohet, J. L.

1980-11-01

30

Effect of lemon juice on pepsin activity between ph 2.4 and 4, the range of achlorhydria  

Microsoft Academic Search

Summary and Conclusions  \\u000a \\u000a \\u000a \\u000a 1. \\u000a Lemon juice accelerates the activity of pepsin between pH 2.4 and 4 whether measured in aqueous solution or in normal saline\\u000a solution.\\u000a \\u000a \\u000a \\u000a 2. \\u000a Peptic acceleration due to lemon juice is greater in isotonic solution at pH 2.4 to 3 than in aqueous solution. Between pH\\u000a 3 to 4 the reverse is true: lemon juice accelerates in

T. C. Manchester

1944-01-01

31

Na + and flagella-dependent swimming of alkaliphilic Bacillus pseudofirmus OF4: a basis for poor motility at low pH and enhancement in viscous media in an “up-motile” variant  

Microsoft Academic Search

Flagella-based motility of extremely alkaliphilic Bacillus species is completely dependent upon Na+. Little motility is observed at pH values < ?8.0. Here we examine the number of flagella\\/cell as a function of growth pH\\u000a in the facultative alkaliphile Bacillus pseudofirmus OF4 and a derivative selected for increased motility on soft agar plates. Flagella were produced by both strains during growth

Shun Fujinami; Naoya Terahara; Sunmi Lee; Masahiro Ito

2007-01-01

32

Empathy: Its ultimate and proximate bases  

Microsoft Academic Search

Short abstract The empathy literature is characterized by debate regarding the nature of the phenomenon. We propose a unified theory of empathy, divided into ultimate and proximate levels, grounded in the emotional link between individuals. On an ultimate level, emotional linkage supports group alarm, vicariousness of emotions, mother-infant responsiveness, and the modeling of competitors and predators; these exist across species

Stephanie D. Preston

2002-01-01

33

Ultimate Strength Analysis of Framed Offshore Structures.  

National Technical Information Service (NTIS)

An efficient method is presented for analysis of the non-linear behavior of offshore structures up to ultimate strength. The algorithm is based on the idealizied structural unit method. Geometrical and material nonlinearities are accounted for by applying...

J. E. van Aanhold

1985-01-01

34

Ultimate Capacity of Steel Columns Loaded Biaxially.  

National Technical Information Service (NTIS)

The problem was to theoretically predict the ultimate capacity of columns loaded biaxially, i.e., columns subjected to an axial load plus terminal bending moments about two principal axes of the cross-section. The material was mild steel and the cross-sec...

J. S. Ellis E. J. Jury D. W. Kirk

1964-01-01

35

Thinking About the Ultimate Argument for Realism  

Microsoft Academic Search

Thinking About the Ultimate Argument for Realism\\u000a \\u000a Stathis Psillos3\\u000a \\u000a \\u000a \\u000a (3) \\u000a Department of Philosophy and History of Science, University of Athens, Greece\\u000a \\u000a \\u000a \\u000a \\u000a Without Abstract

Stathis Psillos

36

Seeking Ultimates. An Intuitive Guide to Physics  

Microsoft Academic Search

Physics has the reputation of being a difficult and dry subject. Many books have been written in attempts to show that the difficulties are not insurmountable, even for the layman, and to convey some of the fascination it provides for those within it. In Seeking Ultimates Peter Landsberg avoids mathematics, the source of so many difficulties, entirely, and seeks to

Neil Brown

2000-01-01

37

The ultimate strength of suture anchors  

Microsoft Academic Search

Suture anchors of various designs are gaining acceptance for open and arthroscopic procedures. The rapid proliferation of these devices challenges those using them to apply objective criteria for device selection. Comparative data on implant security in different settings, modes of failure, and ultimate failure strengths is lacking. This study was undertaken to independently develop such data for an objective comparison

F. Alan Barber; Morley A. Herbert; James N. Click

1995-01-01

38

Death as a Discipline: The Ultimate Curriculum  

Microsoft Academic Search

Does Death Education have a place in today's school curriculum? According to this principal it not only should have a place, but schools have a moral responsibility to include it. Readers wishing specific information on how to incorporate death into the curriculum can write directly to the author at 2126 Fanshawe St., Ph iladel ph ia, Pa. 19149.

Leon Hymovitz

1979-01-01

39

Ultimate computing. Biomolecular consciousness and nano Technology  

SciTech Connect

The book advances the premise that the cytoskeleton is the cell's nervous system, the biological controller/computer. If indeed cytoskeletal dynamics in the nanoscale (billionth meter, billionth second) are the texture of intracellular information processing, emerging ''NanoTechnologies'' (scanning tunneling microscopy, Feynman machines, von Neumann replicators, etc.) should enable direct monitoring, decoding and interfacing between biological and technological information devices. This in turn could result in important biomedical applications and perhaps a merger of mind and machine: Ultimate Computing.

Hameroff, S.R.

1987-01-01

40

The ultimate ownership of Western European corporations  

Microsoft Academic Search

We analyze the ultimate ownership and control of 5,232 corporations in 13 Western European countries. Typically firms are widely held (36.93%) or family controlled (44.29%). Widely held firms are more important in the UK and Ireland, family controlled firms in continental Europe. Financial and large firms are more likely widely held, while non-financial and small firms are more likely family

Mara Faccio; Larry H. P. Lang

2002-01-01

41

Ultimate biodegradation studies of ?-olefin sulfonates  

Microsoft Academic Search

Single carbon cut ?-olefin sulfonates (AOS) having 12, 14, 16 and 18 carbon chain lengths and several of their blends were\\u000a prepared from high-quality ?-olefins by continuous SO3 sulfonation in a laboratory falling film reactor. The ultimate biodegradability of these products was studied using a modified\\u000a shake flask procedure with CO2 evolution as the major biodegradability criterion. For comparison, commercial

L. Kravetz; H. Chung; J. C. Rapean

1982-01-01

42

The Ultimate Analysis of Natural Waters  

Microsoft Academic Search

Although waters have been analyzed for over 2,000 years, no one has yet accomplished a truly complete analysis for the detection and determination of all the ions, the molecules and complex species that must be present. The significance and challenge of the ultimate analysis of waters is discussed.While testifying in a court case in the 1890's, Professor Angstrom swore that

Philip W. West; Roberta Bustin

1972-01-01

43

On the Ultimate Complexity of Factorials  

Microsoft Academic Search

It has long been observed that certain factorization algorithms provide a way to write product of a lot of integers succinctly. In this paper, we study the problem of representing the product of all integers from 1 to n (n!) by straight-line programs. Formally, we say that a sequence of integers an is ultimately f(n)-computable, if there exists a nonzero

Qi Cheng

2003-01-01

44

Is space the ultimate high ground?  

NASA Astrophysics Data System (ADS)

Military experts often refer to space as the ultimate high ground under the premise that placing systems in orbit provides advantages consistent with the military doctrine of high ground. Although space provides the ultimate "observation post", it has none of the other advantages traditionally associated with high ground. Army Field Manual (FM) 34-130 states the other advantages of holding key terrain: commanding avenues of approach, overcoming obstacles, and affording cover and concealment as additional benefits of high ground. Yet systems in orbit incur none of these additional advantages. Finally, international restrictions and reciprocity concerns limit the employment of weapons in space nullifying many of the unique capability advantages that would otherwise support the "high ground" aspect of space. As the ultimate observation post, satellites provide a large quantity of vital data to military decision makers. This massive amount of data needs to have as much context as possible to convert this data to useful knowledge. To use space assets optimally, the military needs to learn from the past and make space and cyber products distributed and tactical. It is absolutely essential to distribute the right information to the lowest level (tactical elements) of the organization or the "boots on the ground" in a timely manner.

Meyer, Gregory J.; Stallings, Francis P.

2011-05-01

45

No way to cool the ultimate greenhouse  

SciTech Connect

When the Clinton Administration announced its Climate Change Action Plan last week, some press accounts called it an effort to halt greenhouse warming. To greenhouse experts, however, cutting emissions of greenhouse gases to 1990 levels by the end of the decade -- the goal of the plan -- will only delay the inevitable. Such modest conservation measures, as a recent study shows, will buy humanity valuable time to adapt to the greenhouse world, but they will have little effect on how warm the global climate ultimately becomes. Centuries down the road, humanity will have to come to grips with elevated temperatures due to increased atmospheric CO[sub 2] levels. Reducing emissions will slow the warming process and give humanity more time to adapt.

Kerr, R.A.

1993-10-29

46

Ultimate cold-electron bolometer with strong electrothermal feedback  

NASA Astrophysics Data System (ADS)

A novel concept of the Cold-Electron Bolometer (CEB) with strong electrothermal feedback has been proposed. The concept is based on direct electron cooling of the absorber that serves as negative electrothermal feedback for incoming signal. This feedback is analogous to TES (transition-edge sensor) but additional dc heating is replaced by deep electron cooling to minimum temperature. It could mean a principle breakthrough in realization of supersensitive detectors. Noise properties are considerably improved by decreasing the electron temperature. The loop gain of electrothermal feedback could exceed 1000. The response time is reduced by electrothermal feedback to 10ns in comparison with the intrinsic e-ph time constant of 10ms. The CEB gives opportunity to increase dynamic range by removing all incoming power from supersensitive absorber to the next stage of readout system (SQUID) with higher dynamic range. Saturation problems are not so severe for CEB as for TES: after exceeding the cooling power there is only slight deviation from linear dependence for voltage response. The full saturation comes at the level of 100pW when temperature of absorber achieves Tc of Al. Ultimate performance of the CEB is determined by shot noise of the signal readout. For relatively low background load P0 =10fW and quantization level Te= 50mK, the limit NEP is equal to 10-19W/Hz1/2. The estimations show that it is realistic to achieve ultimate NEP at 100 mK with SQUID readout system and NEP=10-18W/Hz1/2 at 300mK for background load of 10fW. Applicability of the CEB to post-Herschel missions looks very promising.

Kuzmin, Leonid

2004-10-01

47

Bilabiate Flowers: The Ultimate Response to Bees?  

PubMed Central

Background and Aims Bilabiate flowers have evolved in many lineages of the angiosperms, thus representing a convincing example of parallel evolution. Similar to keel blossoms, they have obviously evolved in order to protect pollen against pollen-collecting bees. Although many examples are known, a comprehensive survey on floral diversity and functional constraints of bilabiate flowers is lacking. Here, the concept is widened and described as a general pattern. Methods The present paper is a conceptional review including personal observations of the authors. To form a survey on the diversity of bilabiate blossoms, a search was made for examples across the angiosperms and these were combined with personal observations collected during the last 25 years, coupled with knowledge from the literature. New functional terms are introduced that are independent of morphological and taxonomic associations. Key Results Bilabiate constructions occur in at least 38 angiosperm families. They are characterized by dorsiventral organization and dorsal pollen transfer. They are most often realised on the level of a single flower, but may also be present in an inflorescence or as part of a so-called ‘walk-around flower’. Interestingly, in functional terms all nototribic blossoms represent bilabiate constructions. The great majority of specialized bee-flowers can thus be included under bilabiate and keel blossoms. The syndrome introduced here, however, also paves the way for the inclusion of larger animals such as birds and bats. The most important evolutionary trends appear to be in the saving of pollen and the precision of its transfer. With special reference to the Lamiales, selected examples of bilabiate flowers are presented and their functional significance is discussed. Conclusions Bilabiate blossoms protect their pollen against pollen-collecting bees and at the same time render their pollination more precisely. The huge diversity of realised forms indicate the high selection pressure towards the bilabiate syndrome. As bees are very inventive, however, bilabiate constructions will not represent the ultimate response to bees.

Westerkamp, Christian; Classen-Bockhoff, Regine

2007-01-01

48

Two ultimate tests of constrained supersymmetry  

NASA Astrophysics Data System (ADS)

We examine the prospects of using two alternative and complementary ways to explore the regions that are favored by global constraints in two simple unified supersymmetric models: the CMSSM and the NUHM. First, we consider BR ( B s ? ? + ? -), which has recently been for the first time measured by LHCb. In the CMSSM we show that ultimate, but realistic, improvement in the determination of the observable to about 5-10% around the Standard Model value would strongly disfavor the A-funnel region, while not affecting much the other favored regions. Second, we show that all the favored regions of the CMSSM will be, for the most part, sensitive to direct dark matter searches in future one-tonne detectors. A signal at low WIMP mass (? 450 GeV) and low spin-independent cross section would then strongly favor the stau coannihilation region while a signal at higher WIMP mass (~ 800 GeV to ~ 1 .2 TeV) would clearly point to the region where the neutralino is higgsino-like with mass ~ 1 TeV. A nearly complete experimental testing of the CMSSM over multi-TeV ranges of superpartner masses, far beyond the reach of direct SUSY searches at the LHC, can therefore be achievable. In the NUHM, in contrast, similar favored regions exist but a sample study reveals that even a precise determination of BR ( B s ? ? + ? -) would have a much less constraining power on the model, including the A-funnel region. On the other hand, this could allow one to, by detecting in one-tonne detectors a signal for 500 GeV ? m? ? 800 GeV, strongly disfavor the CMSSM.

Kowalska, Kamila; Roszkowski, Leszek; Sessolo, Enrico Maria

2013-06-01

49

Ultimate strength of dented steel plates under axial compressive loads  

Microsoft Academic Search

In this paper the ultimate strength characteristics of dented steel plates under axial compressive loads are investigated using the ANSYS nonlinear finite element code. The effects of shape, size (depth, diameter), and location of the dent on the ultimate strength behavior of simply supported steel plates under axial thrust are studied. A closed-form formula for predicting the ultimate compressive strength

Jeom Kee Paik; Jae Myung Lee; Dong Hoon Lee

2003-01-01

50

Hydrolysis and nucleophilic substitution of model and ultimate carcinogens  

SciTech Connect

The hydrolysis reaction of the Model Carcinogen O-pivaloyl-N-(4-chlorophenyl)hydroxylamine in aqueous buffer (pH 7.0-10.0) proceeds by was of a nitrenium ion intermediate. The products formed from this process are predominately 2,4-dichloroaniline, and 2-hydroxy-4-chloro-pivalanilide. At pH 10-13 the rate becomes dependent upon hydroxide. The product that is formed is 4-chlorophenylhydroxylamine. 4-Chlorophenyl-hydroxylamine is formed by basic ester hydrolysis determined by an [sup 18]O GC-MS experiment. The reaction of O-pivaloyl-N-(4-chlorophenyl)hydroxylamine in an aqueous diethylamine (pH 11.3) buffer gave 4-chlorophenyl-N,N-diethylhydrazine as the substitution product in a 16% yield. The reaction of O-pivaloyl-N-(4-methylphenyl)hydroxylamine with diethylamine gave a 1% yield of the hydrazine product. The reaction of N,N-dimethylanline and aniline with ring-substituted O-pivaloyl-N-arylhydroxylamines in MeOH generates products of nucleophilic attack on the nitrogen of the hydroxylamine derivative. The hydrolysis of the ultimate carcinogen N-(sulfonatooxy)-N-4-aminobiphenyl proceeds by two consecutive pseudo-first-order processes and generates predominately a product of nucleophilic attack by chloride ion at the ortho position of the aromatic ring. A labile intermediate identified as N-acetypl-4-hydroxy-4-phenyl-2,5-cyclohexadienone imine has been detected by NMR. This intermediate rearranges to form 4-hydroxy-3-phenylacetanilide. The hydrolysis of N-benzoyl-4-hydroxy-4-hydroxy-4-phenyl-2,5-cyclohexadienone imine proceeds by way of two consecutive pseudo-first-order processes. The hydrolysis of N-benzoyl-4-methoxy-4-phenyl-2,5-cyclohexadienone imine also proceeds by two consecutive pseudo-first-order processes. Spectroscopic evidence of two diastereomeric intermediates formed from the hydrolysis of the N-benzoyl imines were tentatively identified as N-benzoyl-N-hydroxy-4-hydroxy-4-phenyl-2,5-cyclohexadienone imine.

Helmick, J.S.

1992-01-01

51

Ultimate Tensile Strength of Pitch-Based Carbon Fibers.  

National Technical Information Service (NTIS)

Histograms of the average diameter, fiber breaking load and ultimate tensile strength were determined for as-received VSB-320 grade, Thornel P-type carbon fiber. The mean fiber diameter and the mean ultimate tensile strength were determined to be 10.4 mic...

R. K. Everett

1986-01-01

52

Effects of pH adjustment with phosphates on attributes and functionalities of normal and high pH beef  

Microsoft Academic Search

Longissimus dorsi muscles from six normal- and six high-ultimate pH bulls were selected for fine mincing and subsequent pH adjustment with acid and alkaline pyrophosphate. Four pH treatments were prepared: initially high remains high (mean of pH 6.37), high becomes normal (5.62); initially normal remains normal (5.65), and normal becomes high (6.21). The addition level of phosphate as P2O5 was

O. A. Young; S. X. Zhang; M. M. Farouk; C. Podmore

2005-01-01

53

Process Inherent Ultimate Safety (PIUS) Reactor Evaluation Study: Final Report.  

National Technical Information Service (NTIS)

This report presents the results of an independent study by United Engineers and Constructors (UNITED) of the SECURE-P Process Inherent Ultimate Safety (PIUS) Reactor Concept which is presently under development by the Swedish light water reactor vendor A...

1987-01-01

54

Collisions and their Catenations: Ultimately Periodic Tilings of the Plane  

Microsoft Academic Search

Motivated by the study of cellular automata algorithmic and dynamics, we investigate an extension of ultimately periodic words\\u000a to two-dimensional infinite words: collisions. A natural composition operation on tilings leads to a catenation operation\\u000a on collisions. By existence of aperiodic tile sets, ultimately periodic tilings of the plane cannot generate all possible\\u000a tilings but exhibit some useful properties of their

Nicolas Ollinger; Gaétan Richard

2008-01-01

55

Ultimate load analysis of plate reinforced concrete beams  

Microsoft Academic Search

In a previous paper, the experimental work carried out on concrete–steel composite beams utilising the ‘encased plate construction’ was presented. The provision of steel plates as shear reinforcement allows very high shear stresses to be safely developed. This is a new concept in the design of reinforced concrete beams. This paper describes the structural behaviour and ultimate limit state analysis

Nutan Kumar Subedi; Paul Stuart Baglin

2001-01-01

56

Launching GUPPI: the Green Bank Ultimate Pulsar Processing Instrument  

Microsoft Academic Search

The National Radio Astronomy Observatory (NRAO) is launching the Green Bank Ultimate Pulsar Processing Instrument (GUPPI), a prototype flexible digital signal processor designed for pulsar observations with the Robert C. Byrd Green Bank Telescope (GBT). GUPPI uses field programmable gate array (FPGA) hardware and design tools developed by the Center for Astronomy Signal Processing and Electronics Research (CASPER) at the

Ron DuPlain; Scott Ransom; Paul Demorest; Patrick Brandt; John Ford; Amy L. Shelton

2008-01-01

57

Methods for ultimate load analysis of concrete containments  

Microsoft Academic Search

The objective of the research project described in this interim report is to develop a qualified methodology for the ultimate load analysis of concrete containment structures. The EPRI-sponsored nonlinear finite element code ABAQUS-EPGEN, which has recently been modified to incorporate a constitutive model for plain concrete and modeling capabilities for reinforced and prestressed concrete containments, is utilized as the structural

R. S. Dunham; Y. R. Rashid; K. A. Yuan; Y. M. Lu

1985-01-01

58

BOOK REVIEW: Seeking Ultimates. An Intuitive Guide to Physics  

Microsoft Academic Search

Physics has the reputation of being a difficult and dry subject. Many books have been written in attempts to show that the difficulties are not insurmountable, even for the layman, and to convey some of the fascination it provides for those within it. In Seeking Ultimates Peter Landsberg avoids mathematics, the source of so many difficulties, entirely, and seeks to

Peter T. Landsberg

2000-01-01

59

Ultimate Lateral Pile Capacity in Two-Layer Soil.  

National Technical Information Service (NTIS)

Expressions are derived for the ultimate lateral load capacity of a pile in a two-layer cohesive soil profile. Both free head and fixed head piles are considered and in each case, dimensionless solutions are given for failure of the supporting soil ('shor...

H. G. Poulos

1985-01-01

60

Biaxial tension and ultimate deformation of knitted fabric reinforcements  

Microsoft Academic Search

In this study, the behavior under biaxial tension of two types of glass knitted fabrics, a rib and a milano weft knit, was investigated. The tests were performed using a homemade biaxial tester, which is capable of applying displacement velocity in two orthogonal directions independently. The ultimate deformation in both wale and course directions was determined at different displacement ratios.

Y Luo; I Verpoest

2002-01-01

61

The Ultimate Sampling Dilemma in Experience-Based Decision Making  

ERIC Educational Resources Information Center

Computer simulations and 2 experiments demonstrate the ultimate sampling dilemma, which constitutes a serious obstacle to inductive inferences in a probabilistic world. Participants were asked to take the role of a manager who is to make purchasing decisions based on positive versus negative feedback about 3 providers in 2 different product…

Fiedler, Klaus

2008-01-01

62

Ultimate capacity of I-slender section columns  

Microsoft Academic Search

The design provisions in most codes of practice usually use the concept of effective width to account for the presence of local buckling when calculating the ultimate capacity of slender sections. The expressions used to calculate this effective width are function of many variables. One of these variables is the state of stress within the section. This state of stress

A. H. Salem; M. El Aghoury; F. F. El Dib; M. T. Hanna

2004-01-01

63

The load sequence effects on structures’ ultimate limit strength evaluation  

Microsoft Academic Search

This paper intends to draw attention to the consideration of load sequence effects on the structures’ installation and upgrading\\/reinforcement practice. The paper first summarises four types of load sequence effects encountered in structural engineering practice. In order to investigate the ultimate strength performance of structures with the variation of support conditions and member stiffness (due to the installation of reinforcement

Junbo Jia

2011-01-01

64

Immediate and Ultimate Functions of Physical Activity Play.  

ERIC Educational Resources Information Center

|Play has been difficult to define because it is an aspect of many activities rather than of just a specific kind of activity. Classic theorists such as Piaget and Vygotsky emphasized representational play as play in its purist form, but both immediate and ultimate functions of play can be discerned in simple physical activity play. (Author)|

McCune, Lorraine

1998-01-01

65

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.

66

Shear wall ultimate drift limits for PRA applications  

SciTech Connect

Drift limits for reinforced concrete shear walls are investigated by reviewing the technical literature for appropriate experimental data. Based on the geometry of actual nuclear power plant structures (exclusive of containments) and concerns regarding their response during seismic loading, data are obtained from pertinent references where the wall aspect ratio is less than or equal to approximately 1, and for which the loading is cyclic. Lateral deflections at ultimate load, and at points in the softening region beyond ultimate, are obtained and converted to drift information. The statistical nature of the data is also investigated. These data are shown to be lognormally distributed, and an analysis of variance is performed. The use of these statistics to estimate Probability of Failure for a shear wall structure is illustrated.

Duffey, T.A. [New Mexico Highlands Univ., Las Vegas, NM (United States); Farrar, C.R.; Goldman, A. [Los Alamos National Lab., NM (United States)

1995-03-01

67

Spontaneous thermal runaway as an ultimate failure mechanism of materials.  

PubMed

The first theoretical estimate of the shear strength of a perfect crystal was given by Frenkel [Z. Phys. 37, 572 (1926)10.1007/BF01397292]. By assuming that two rigid atomic rows in the crystal would move over each other along a slip plane, he derived the ultimate shear strength to be about one-tenth of the shear modulus. Here we present a theoretical study showing that catastrophic failure of viscoelastic materials may occur below Frenkel's ultimate limit as a result of thermal runaway. The thermal runaway failure mechanism exhibits progressive localization of the strain and temperature profiles in space, thereby producing a narrow region of highly deformed material, i.e., a shear band. We calculate the maximum shear strength sigma_{c} of materials and then demonstrate the relevance of this new concept for material failure known to occur at scales ranging from nanometers to kilometers. PMID:17359169

Braeck, S; Podladchikov, Y Y

2007-03-02

68

Ultimate collapse tests of stiffened-plate ship structural units  

Microsoft Academic Search

An increasingly popular approximate method for assessing ship hull girder ultimate strength is to combine the individual elasto-plastic load-carrying characteristics of each single stiffened-plate unit comprising the ship hull cross section. In order to evaluate methods (numerical and experimental) for developing the load-carrying characteristics (load–shortening curves), a full-scale testing system was designed and constructed to provide data for stiffened steel

S. Z. Hu; Q. Chen; N. Pegg; T. J. E. Zimmerman

1997-01-01

69

Sugar fatty acid ester surfactants: Structure and ultimate aerobic biodegradability  

Microsoft Academic Search

Ultimate aerobic biodegradabilities of an array of sugar ester surfactants were determined by International Standards Organisation\\u000a method 7827, “Water Quality—Evaluation in an Aqueous Medium of the Aerobic Biodegradability of Organic Compounds, Method by\\u000a Dissolved Organic Carbon” (1984). The surfactants were nonionic sugar esters with different-sized sugar head groups (formed\\u000a from glucose, sucrose, or raffinose) and different lengths and numbers of

Irene J. A. Baker; Barry Matthews; Hector Suares; Irena Krodkiewska; D. Neil Furlong; Franz Grieser; Calum I. Drummond

2000-01-01

70

Ultimate performance of heterodyne\\/coherent optical fiber communications  

Microsoft Academic Search

Research and development of heterodyne\\/homodyne and coherent optical fiber communications have expanded rapidly because of the expectation for repeater separation elongation and superwide-band frequency-division multiplexing. In this paper, recent progress in heterodyne\\/coherent optical fiber communications is reviewed with emphasis on theoretical and experimental studies pursuing its ultimate performance. The topics discussed are: the recent and future trend in the system

Takanori Okoshi; Differential PSK

1986-01-01

71

75 FR 60133 - Agency Information Collection Activities: Declaration of Ultimate Consignee That Articles Were...  

Federal Register 2010, 2011, 2012, 2013

...Information Collection Activities: Declaration of Ultimate Consignee That Articles...collection requirement concerning the Declaration of Ultimate Consignee That Articles...information collection: Title: Declaration of Ultimate Consignee That...

2010-09-29

72

75 FR 76746 - Agency Information Collection Activities: Declaration of Ultimate Consignee That Articles Were...  

Federal Register 2010, 2011, 2012, 2013

...Information Collection Activities: Declaration of Ultimate Consignee That Articles...the Paperwork Reduction Act: Declaration of Ultimate Consignee That Articles...forms of information. Title: Declaration of Ultimate Consignee That...

2010-12-09

73

Rapid population growth and environmental degradation: ultimate versus proximate factors.  

PubMed

This philosophical review of 2 arguments about responsibility for and solutions to environmental degradation concludes that both sides are correct: the ultimate and the proximal causes. Ultimate causes of pollution are defined as the technology responsible for a given type of pollution, such as burning fossil fuel; proximate causes are defined as situation-specific factors confounding the problem, such as population density or rate of growth. Commoner and others argue that developed countries with low or negative population growth rates are responsible for 80% of world pollution, primarily in polluting technologies such as automobiles, power generation, plastics, pesticides, toxic wastes, garbage, warfaring, and nuclear weapons wastes. Distortionary policies also contribute; examples are agricultural trade protection, land mismanagement, urban bias in expenditures, and institutional rigidity., Poor nations are responsible for very little pollution because poverty allows little waste or expenditures for polluting, synthetic technologies. The proximal causes of pollution include numbers and rate of growth of populations responsible for the pollution. Since change in the ultimate cause of pollution remains out of reach, altering the numbers of polluters can make a difference. Predictions are made for proportions of the world's total waste production, assuming current 1.6 tons/capita for developed countries and 0.17 tons/capita for developing countries. If developing countries grow at current rates and become more wealthy, they will be emitting half the world's waste by 2025. ON the other hand, unsustainable population growth goes along with inadequate investment in human capital: education, health, employment, infrastructure. The solution is to improve farming technologies in the 117 non-self-sufficient countries, fund development in the most unsustainable enclaves of growing countries, break institutionalized socio-political rigidity in these enclaves, and focus on educating and empowering women in these enclaves. Women are in charge of birth spacing and all aspects of management of energy, food, water and the local environment, more so than men, in most countries. PMID:12284190

Shaw, R P

1989-01-01

74

The ultimate challenge: prove B. F. Skinner wrong.  

PubMed

For much of his career, B. F. Skinner displayed the optimism that is often attributed to behaviorists. With time, however, he became less and less sanguine about the power of behavior science to solve the major problems facing humanity. Near the end of his life he concluded that a fair consideration of principles revealed by the scientific analysis of behavior leads to pessimism about our species. In this article I discuss the case for Skinner's pessimism and suggest that the ultimate challenge for behavior analysts today is to prove Skinner wrong. PMID:22478494

Chance, Paul

2007-01-01

75

The ultimate fate of life in an accelerating universe  

NASA Astrophysics Data System (ADS)

The ultimate fate of life in a universe with accelerated expansion is considered. Previous work [J.D. Barrow, F. Tipler, The Anthropic Cosmological Principle, Oxford Univ. Press, Oxford, 1986; L.M. Krauss, G.D. Starkman, Astrophys. J. 531 (2000) 22] showed that life cannot go on indefinitely in a universe dominated by a cosmological constant. In this Letter we consider instead other models of acceleration (including quintessence and Cardassian expansion). We find that it is possible in these cosmologies for life to persist indefinitely. As an example we study potentials of the form V~?n and find the requirement /n<-2.

Freese, Katherine; Kinney, William H.

2003-04-01

76

The Ultimate Challenge: Prove B. F. Skinner Wrong  

PubMed Central

For much of his career, B. F. Skinner displayed the optimism that is often attributed to behaviorists. With time, however, he became less and less sanguine about the power of behavior science to solve the major problems facing humanity. Near the end of his life he concluded that a fair consideration of principles revealed by the scientific analysis of behavior leads to pessimism about our species. In this article I discuss the case for Skinner's pessimism and suggest that the ultimate challenge for behavior analysts today is to prove Skinner wrong.

Chance, Paul

2007-01-01

77

Some Physics Constraints on Ultimate Achievement in Track and Field  

ScienceCinema

World records in track and field have improved remarkably throughout the last 100 years; however, in several events physics places quite strict limitations on ultimate performance. For example, analysis suggests that records in broad jump and pole vault have approached their optimum possible values. Physical constraints are more subtle for events such as javelin, high jump, and the distance races, and thus there may be opportunities for “breakthroughs” in current records. Considering that there is enormous cultural interest and economic expenditure on sports, for most events the level of scientific analysis isn’t very high. This presents a research opportunity for fans who are engineers or physicists.

78

The ultimate limit to the emission linewidth of single nanocrystals.  

PubMed

Measurements of the emission linewidth of single nanocrystals are usually limited by spectral diffusion. At cryogenic temperatures, the origin of this instability was revealed to be photo-induced, suggesting that the spectral peak position may be stable in the limit of vanishing optical excitation. Here we test this stability using resonant photoluminescence excitation and find there is persistent spectral broadening, which ultimately limits the emission linewidth in these materials. The spectral broadening is shown to be consistent with spontaneous fluctuations of the local electrostatic field within the disordered environment surrounding the nanocrystal. PMID:24157598

Fernée, Mark J; Sinito, Chiara; Louyer, Yann; Tamarat, Philippe; Lounis, Brahim

2013-10-24

79

Methods for ultimate load analysis of concrete containments  

SciTech Connect

The objective of the research project described in this interim report is to develop a qualified methodology for the ultimate load analysis of concrete containment structures. The EPRI-sponsored nonlinear finite element code ABAQUS-EPGEN, which has recently been modified to incorporate a constitutive model for plain concrete and modeling capabilities for reinforced and prestressed concrete containments, is utilized as the structural analysis tool in this development. The ABAQUS-EPGEN concrete modeling and analysis capabilities are first evaluated by comparing measured data with code predictions for full-scale reinforced concrete slab specimens tested under uniaxial and biaxial tension. These specimen tests simulate the behavior of the cylindrical wall of a typical concrete containment structure under internal pressure. The calculated and measured strain comparisons are used to improve the constitutive model and to qualify the code for concrete containment analysis. The second part of this effort deals with the ultimate load analysis of reinforced and prestressed containments to determine bounds on the global overpressure capacities of typical concrete containment structures. The third part of this effort further examines such local effects through a substructural analysis of the liner-concrete interaction at major concrete cracks.

Dunham, R.S.; Rashid, Y.R.; Yuan, K.A.; Lu, Y.M.

1985-06-01

80

The Displacement Perspective During Ultimate Failure of Composite Laminates  

NASA Astrophysics Data System (ADS)

This paper deals with the studies on the state of displacement of symmetric and anti-symmetric angle-ply and cross-ply laminated composite plates during its ultimate failure, subjected to transverse static load. First-order shear deformation theory (FSDT) is employed in conjunction with the finite element approach using eight-noded quadratic isoparametric element. The free vibration analyses of isotropic and laminated composite plates are carried out to ensure the overall validity of the present finite element formulation. The mid surface of the laminate is considered as the reference plane. The principal material directions in different laminae are oriented to produce a laminated structural element capable of resisting loads in several directions. The stiffness of a composite laminate is obtained from the properties of the constituent laminae. The affected stiffness of the failed lamina is discarded completely after the failure of weakest ply. The rigidity matrix of the laminate with remaining laminae is re-established. The re-evaluation process continues until the laminate fails completely. To investigate the displacement behaviour of laminates during the ultimate failure, parametric studies are carried out for different cases by varying the stacking sequences, fiber orientations, layer thicknesses, aspect ratios and the number of layers in the laminate. The comparison of results in terms of non-dimensional natural frequencies and ply-by-ply failure analyses obtained from the present investigation are made with those available in the reported literature.

Pal, P.; Bhar, A.

2013-04-01

81

What is the Ultimate Goal in Acid-Base Regulation?  

ERIC Educational Resources Information Center

|It is common to see chapters on acid-base physiology state that the goal of acid-base regulatory mechanisms is to maintain the pH of arterial plasma and not arterial PCO [subscript 2] (Pa[subscript CO[subscript 2

Balakrishnan, Selvakumar; Gopalakrishnan, Maya; Alagesan, Murali; Prakash, E. Sankaranarayanan

2007-01-01

82

Ultimate strength of solids and formation of planetary cores  

NASA Astrophysics Data System (ADS)

The ultimate strength of silicates, such as found in the earth's mantle, are examined as a clue to the time that the core of the planet formed. Previous studies are cited of the silicate strength 1-2 GPa, while ice displays a 0.1 GPa, and the confining pressures in planetary interiors cannot increase these strengths by more than a factor of two. Deviatoric stresses are calculated for regions near the bottom of some heterogeneity at a certain distance from the center of the planet. The minimum size of a heterogeneity necessary to break through the mantle and sink toward the core is found to be a few tens of kilometers. These conditions are argued to have been possibly met when the earth was only 1.5% of the current total mass. Iron melting is concluded to be necessary for the core segregation to begin, and protoplanetary interiors are noted to offer little resistance to the flow of iron blobs.

Davies, G. F.

1982-11-01

83

Helium separation via porous silicene based ultimate membrane  

NASA Astrophysics Data System (ADS)

Helium purification has become more important for increasing demands in scientific and industrial applications. In this work, we demonstrated that the porous silicene can be used as an effective ultimate membrane for helium purification on the basis of first-principles calculations. Prinstine silicene monolayer is impermeable to helium gas with a high penetration energy barrier (1.66 eV). However, porous silicene with either Stone-Wales (SW) or divacancy (555 777 or 585) defect presents a surmountable barrier for helium (0.33 to 0.78 eV) but formidable for Ne, Ar, and other gas molecules. In particular, the porous silicene with divacancy defects shows high selectivity for He/Ne and He/Ar, superior to graphene, polyphenylene, and traditional membranes.

Hu, Wei; Wu, Xiaojun; Li, Zhenyu; Yang, Jinlong

2013-09-01

84

Ultimate Decoherence Border for Matter-Wave Interferometry  

SciTech Connect

Stochastic backgrounds of gravitational waves are intrinsic fluctuations of spacetime which lead to an unavoidable decoherence mechanism. This mechanism manifests itself as a degradation of the contrast of quantum interferences. It defines an ultimate decoherence border for matter-wave interferometry using larger and larger molecules. We give a quantitative characterization of this border in terms of figures involving the gravitational environment as well as the sensitivity of the interferometer to gravitational waves. The known level of gravitational noise determines the maximal size of the molecular probe for which interferences may remain observable. We discuss the relevance of this result in the context of ongoing progresses towards more and more sensitive matter-wave interferometry.

Lamine, Brahim; Herve, Remy; Lambrecht, Astrid; Reynaud, Serge [Laboratoire Kastler Brossel, Universite Pierre et Marie Curie, case74, Campus Jussieu, F-75252 Paris cedex 05 (France)

2006-02-10

85

Ultimate photovoltage in perovskite oxide heterostructures with critical film thickness  

SciTech Connect

One order larger photovoltage is obtained with critical thicknesses of La{sub 0.9}Sr{sub 0.1}MnO{sub 3} films in both kinds of heterostructures of La{sub 0.9}Sr{sub 0.1}MnO{sub 3}/SrTiO{sub 3} (0.8 wt % Nb-doped) and La{sub 0.9}Sr{sub 0.1}MnO{sub 3}/Si fabricated at various oxygen pressures. Our self-consistent calculation reveals that the critical thickness of the La{sub 0.9}Sr{sub 0.1}MnO{sub 3} film with the ultimate value of photovoltage is just the thickness of the depletion layer of La{sub 0.9}Sr{sub 0.1}MnO{sub 3} in both heterojunctions, respectively.

Wang Cong; Jin Kuijuan; Zhao Ruiqiang; Lu Huibin; Guo Haizhong; Ge Chen; He Meng; Wang Can; Yang Guozhen [Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China)

2011-05-02

86

Mathematical modeling of ultimate heat sink cooling ponds  

NASA Astrophysics Data System (ADS)

A general treatment of ultimate heat sink (UHS) cooling pond thermal performance is proposed through the application of a three-dimensional grid model. Validation of the model has been shown through comparisons of predictions with data from a field and laboratory pond. The advantage of the model lies in its ability to determine the detailed character of the flow field whether it be one, two, or three dimensional. Existing models require a priori knowledge of the character and dimensionality of the flow field in such ponds. Application of the model to a prototype UHS pond revealed that the balance of physical mechanisms involved in the thermal hydraulics of these ponds is quite different than for ponds used in normal cooling. The small, heavily-loaded, irregularly-shaped nature of the UHS pond should, in many cases, lead to a vertically mixed pond with only a one-dimensional (longitudinal) variation in pond temperature.

Policastro, A. J.; Wastag, M.; Dunn, W. E.; Leylak, J.; Gavin, F.; Carhart, R. A.

1985-03-01

87

Ultimate top-down processes for future nanoscale devices  

NASA Astrophysics Data System (ADS)

For the past 30 years, plasma etching technology has led in the efforts to shrink the pattern size of ultralarge-scale integrated (ULSI) devices. However, inherent problems in the plasma processes, such as charge buildup and UV photon radiation, limit the etching performance for nanoscale devices. To overcome these problems and fabricate sub-10-nm devices in practice, neutral-beam etching has been proposed. In this paper, we introduce the ultimate etching processes using neutral-beam sources and discuss the fusion of top-down and bottom-up processing for future nanoscale devices. Neutral beams can perform atomically damage-free etching and surface modification of inorganic and organic materials. This technique is a promising candidate for the practical fabrication technology for future nano-devices.

Samukawa, Seiji

2012-03-01

88

Ultimate photovoltage in perovskite oxide heterostructures with critical film thickness  

NASA Astrophysics Data System (ADS)

One order larger photovoltage is obtained with critical thicknesses of La0.9Sr0.1MnO3 films in both kinds of heterostructures of La0.9Sr0.1MnO3/SrTiO3 (0.8 wt % Nb-doped) and La0.9Sr0.1MnO3/Si fabricated at various oxygen pressures. Our self-consistent calculation reveals that the critical thickness of the La0.9Sr0.1MnO3 film with the ultimate value of photovoltage is just the thickness of the depletion layer of La0.9Sr0.1MnO3 in both heterojunctions, respectively.

Wang, Cong; Jin, Kui-Juan; Zhao, Rui-Qiang; Lu, Hui-Bin; Guo, Hai-Zhong; Ge, Chen; He, Meng; Wang, Can; Yang, Guo-Zhen

2011-05-01

89

Future Synchrotron Light Sources Based on Ultimate Storage Rings  

SciTech Connect

The main purpose of this talk is to describe how far one might push the state of the art in storage ring design. The talk will start with an overview of the latest developments and advances in the design of synchrotron light sources based on the concept of an 'ultimate' storage ring. The review will establish how bright a ring based light source might be, where the frontier of technological challenges are, and what the limits of accelerator physics are. Emphasis will be given to possible improvements in accelerator design and developments in technology toward the goal of achieving an ultimate storage ring. An ultimate storage ring (USR), defined as an electron ring-based light source having an emittance in both transverse planes at the diffraction limit for the range of X-ray wavelengths of interest for a scientific community, would provide very high brightness photons having high transverse coherence that would extend the capabilities of X-ray imaging and probe techniques beyond today's performance. It would be a cost-effective, high-coherence 4th generation light source, competitive with one based on energy recovery linac (ERL) technology, serving a large number of users studying material, chemical, and biological sciences. Furthermore, because of the experience accumulated over many decades of ring operation, it would have the great advantage of stability and reliability. In this paper we consider the design of an USR having 10-pm-rad emittance. It is a tremendous challenge to design a storage ring having such an extremely low emittance, a factor of 100 smaller than those in existing light sources, especially such that it has adequate dynamic aperture and beam lifetime. In many ultra-low emittance designs, the injection acceptances are not large enough for accumulation of the electron beam, necessitating on-axis injection where stored electron bunches are completely replaced with newly injected ones. Recently, starting with the MAX-IV 7-bend achromatic cell, we have made significant progress with the design of PEP-X, a USR that would inhabit the decommissioned PEP-II tunnel at SLAC. The enlargement of the dynamic aperture is largely a result of the cancellations of the 4th-order resonances in the 3rd-order achromats and the effective use of lattice optimization programs. In this paper, we will show those cancellations of the 4th-order resonances using an analytical approach based on the exponential Lie operators and the Poisson brackets. Wherever possible, our analytical results will be compared with their numerical counterparts. Using the derived formulae, we will construct 4th-order geometric achromats and use them as modules for the lattice of the PEP-X USR, noting that only geometric terms are canceled to the 4th order.

Cai, Yunhai; /SLAC

2012-04-09

90

The development of high cooling power and low ultimate temperature superfluid Stirling refrigerators  

NASA Astrophysics Data System (ADS)

The superfluid Stirling refrigerator (SSR) is a recuperative Stirling cycle refrigerator which provides cooling to below 2 K by using a liquid 3He-4He mixture as the working fluid. In 1990, Kotsubo and Swift demonstrated the first SSR, and by 1995, Brisson and Swift had developed an experimental prototype capable of reaching a low temperature of 296 mK. The goal of this thesis was to improve these capabilities by developing a better understanding of the SSR and building SSR's with higher cooling powers and lower ultimate temperatures. This thesis contains four main parts. In the first part, a numerical analysis demonstrates that the optimal design and ultimate performance of a recuperative Stirling refrigerator is fundamentally different from that of a standard regenerative Stirling refrigerator due to a mass flow imbalance within the recuperator. The analysis also shows that high efficiency recuperators remain a key to SSR performance. Due to a quantum effect called Kapitza resistance, the only realistic and economical method of creating higher efficiency recuperators for use with an SSR is to construct the heat exchangers from very thin (12 ?m - 25 ?m thick) plastic films. The second part of this thesis involves the design and construction of these recuperators. This research resulted in Kapton heat exchangers which are leaktight to superfluid helium and capable of surviving repeated thermal cycling. In the third part of this thesis, two different single stage SSR's are operated to test whether the plastic recuperators would actually improve SSR performance. Operating from a high temperature of 1.0 K and with 1.5% and 3.0% 3He-4He mixtures, these SSR's achieved a low temperature of 291 mK and delivered net cooling powers of 3705 ?W at 750 mK, 977 ?W at 500 mK, and 409 ?W at 400 mK. Finally, this thesis describes the operation of three versions of a two stage SSR. Unfortunately, due to experimental difficulties, the merits of a two stage SSR were not demonstrated and further work is still required. However, despite these difficulties, one of the two stage SSR's was able to reach an ultimate low temperature of 248 mK from a high temperature of 1.03 K. (Copies available exclusively from MIT Libraries, Rm. 14-0551, Cambridge, MA 02139-4307. Ph. 617-253-5668; Fax 617-253-1690.)

Patel, Ashok B.

91

A process inherent ultimate safety boiling water reactor  

SciTech Connect

A new type of boiling water reactor (BWR) - the process inherent ultimate safety (PIUS) BWR - has been conceived. A PIUS BWR is an advanced BWR that differs from the typical BWR in that a prestressed concrete reactor vessel (PCRV) with special internals replaces the conventional pressure vessel, emergency core cooling system, containment shell, spent fuel storage ponds, and most other components on the nuclear island. The reactor core and balance of plant are similar to current BWR designs. This approach effectively eliminates the possibility of reactor core meltdown and simplifies plant design. The PIUS BWR does not require operation of any mechanical or electrical components in any emergency for reactor shutdown or afterheat cooling, nor does it depend on any equipment outside the PCRV. The PCRV contains a natural circulation BWR; cool, borated water for emergency core cooling; a mechanism ''X'' that allows the cool, borated water to enter the reactor core if there is insufficient water in the core; and a mechanism ''Y'' that limits core power levels to available cooling capabilities.

Forsberg, C.W.

1986-02-01

92

Process Inherent Ultimate Safety (PIUS) reactor evaluation study: Final report  

SciTech Connect

This report presents the results of an independent study by United Engineers and Constructors (UNITED) of the SECURE-P Process Inherent Ultimate Safety (PIUS) Reactor Concept which is presently under development by the Swedish light water reactor vendor ASEA-ATOM of Vasteras, Sweden. This study was performed to investigate whether there is any realistic basis for believing that the PIUS reactor could be a viable competitor in the US energy market in the future. Assessments were limited to the technical, economic and licensing aspects of PIUS. Socio-political issues, while certainly important in answering this question, are so broad and elusive that it was considered that addressing them with the limited perspective of one small group from one company would be of questionable value and likely be misleading. Socio-political issues aside, the key issue is economics. For this reason, the specific objectives of this study were to determine if the estimated PIUS plant cost will be competitive in the US market and to identify and evaluate the technical and licensing risks that might make PIUS uneconomical or otherwise unacceptable.

Not Available

1987-02-01

93

Launching GUPPI: the Green Bank Ultimate Pulsar Processing Instrument  

NASA Astrophysics Data System (ADS)

The National Radio Astronomy Observatory (NRAO) is launching the Green Bank Ultimate Pulsar Processing Instrument (GUPPI), a prototype flexible digital signal processor designed for pulsar observations with the Robert C. Byrd Green Bank Telescope (GBT). GUPPI uses field programmable gate array (FPGA) hardware and design tools developed by the Center for Astronomy Signal Processing and Electronics Research (CASPER) at the University of California, Berkeley. The NRAO has been concurrently developing GUPPI software and hardware using minimal software resources. The software handles instrument monitor and control, data acquisition, and hardware interfacing. GUPPI is currently an expert-only spectrometer, but supports future integration with the full GBT production system. The NRAO was able to take advantage of the unique flexibility of the CASPER FPGA hardware platform, develop hardware and software in parallel, and build a suite of software tools for monitoring, controlling, and acquiring data with a new instrument over a short timeline of just a few months. The NRAO interacts regularly with CASPER and its users, and GUPPI stands as an example of what reconfigurable computing and open-source development can do for radio astronomy. GUPPI is modular for portability, and the NRAO provides the results of development as an open-source resource.

DuPlain, Ron; Ransom, Scott; Demorest, Paul; Brandt, Patrick; Ford, John; Shelton, Amy L.

2008-08-01

94

The ultimate band compression factor in gradient elution chromatography  

SciTech Connect

The equations predicting the ultimate time band compression factor, G = (t{sub R}-t{sub F})/t{sub p} in linear gradient elution chromatography, for an infinitely narrow injection (injection time t{sub p} {yields} 0) were derived for an ideal-model column (dispersionless chromatography, H = 0) assuming the Linear Solvent Strength Model for the retention behavior of the analyte. Numerical solutions can readily be obtained when the LSSM model does not apply. The results can be generalized to any retained organic modifier (k'{sub A}) in the mobile phase. The stronger the retention of the organic modifier, the more effective the band compression. Dispersion in real chromatographic column (H {ne} 0) affects the limits that can be reached in linear gradients but poorly in step gradients. Examples based on a conventional HETP of about 12 {micro}m using a 5 {micro}m particle packed column reveal that the best time compression factor that could be expected is twice the one predicted with an ideal column.

Gritti, Fabrice [University of Tennessee, Knoxville (UTK); Guiochon, Georges A [ORNL

2008-01-01

95

Digital exchange of graphic arts material: the ultimate challenge  

NASA Astrophysics Data System (ADS)

The digital exchange of graphic arts material -- particularly advertising material for publications -- in an open standardized environment represents the ultimate challenge for electronic data exchange. To meet the needs of publication advertising, the graphic arts industry must be able to transmit advertisements in an open environment where there are many senders and many receivers of the material. The material being transmitted consists of combinations of pictorial material, text, and line art with these elements superimposed on top of each other and/or interrelated in complex ways. The business relationships established by the traditional workflow environment, the combination of aesthetic and technical requirements, and the large base of existing hardware and software play a major role in limiting the options available. Existing first- and second-generation standards are focused on the CEPS environment, which operates on and stores data as raster files. The revolution in personal computer hardware and software, and the acceptance of these tools by the graphic arts community, dictates that standards must also be created and implemented for this world of vector/raster-based systems. The requirements for digital distribution of advertising material for publications, the existing graphic arts standards base, and the anticipation of future standards developments in response to these needs are explored.

McDowell, David Q.

1996-01-01

96

Ultimate storage ring based on fourth-order geometric achromats  

NASA Astrophysics Data System (ADS)

We have designed an “ultimate” storage ring for a future light source that would be resided in the positron-electron-project (PEP) tunnel and achieves the diffraction-limited emittances (at 1.5 Å) of 12 pm-rad in both horizontal and vertical planes with a 4.5-GeV electron beam. These emittances include the contribution of intrabeam scattering at a nominal current of 200 mA in 3300 bunches. This quality beam in conjunction with a conventional 4-m undulator in a straight section can generate synchrotron radiation having a spectral brightness above 1022[photons/s/mm2/mrad2/0.1%BW] at a 10 keV photon energy. The high coherence at the diffraction limit makes this design competitive with 4th generation light sources based on an energy recovery linac. In addition, the beam lifetime is several hours and the dynamic aperture is large enough to allow off-axis injection. The alignment and stability tolerances, though challenging, are achievable. A ring with all these properties is only possible because of several major advances in mitigating the effects of nonlinear resonances.

Cai, Yunhai; Bane, Karl; Hettel, Robert; Nosochkov, Yuri; Wang, Min-Huey; Borland, Michael

2012-05-01

97

Ultimate photovoltage in perovskite oxide heterostructures with critical film thickness  

NASA Astrophysics Data System (ADS)

One order larger photovoltage is obtained with critical thicknesses of La0.9Sr0.1MnO3 films in both kinds of heterostructures of La0.9Sr0.1MnO3/SrTiO3 (0.8 wt % Nb-doped) and La0.9Sr0.1MnO3/Si fabricated at various oxygen pressures. Our self-consistent calculation reveals that the critical thickness of the La0.9Sr0.1MnO3 film with the ultimate value of photovoltage is just the thickness of the depletion layer of La0.9Sr0.1MnO3 in the p-n heterostructures of La0.9Sr0.1MnO3/SrTiO3 (0.8 wt % Nb-doped) and La0.9Sr0.1MnO3/Si, respectively.

Jin, Kui-Juan; Wang, Cong

2012-02-01

98

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

99

[The relationships of Zhang Jing-yue's three theories of the Supreme Ultimate.].  

PubMed

Under the influence of Supreme Ultimate of Neo-Confucianism, Zhang Jing-yue put forward the three theories of the Supreme Ultimate, viz., Supreme Ultimate of the Primordial Qi, Supreme Ultimate of the Heart, and Supreme Ultimate of the Vital Gate. These three theorise were of trinity relationship, forming the basic frame of Jingyue's system of medical theories. Among them, the theory of Supreme Ultimate of the Primordial Qi was the foundation of natural concept in his medical theories, the theory of Supreme Ultimate of the Vital Gate was the teleology of his medical theories, and the theory of Supreme Ultimate of the Heart, as a cognitive method, was the methodology of his medical theories. Jing-yue's medical theories were constructed on these three corner-stays, which was a tremendous leap forward in the development of traditional Chinese medicine and Neo-Confucianism. PMID:19222965

Yao, Chun-Peng

2008-07-01

100

75 FR 11922 - Apria Healthcare, Including On-Site Leased Workers From Corestaff, Ultimate Staffing (Roth...  

Federal Register 2010, 2011, 2012, 2013

...Workers From Corestaff, Ultimate Staffing (Roth Staffing Companies), and Aerotek, Cromwell...unemployment insurance (UI) tax account for Roth Staffing Companies. The Department has...workers leased from Ultimate Staffing (Roth Staffing Companies) and Aerotek...

2010-03-12

101

78 FR 55117 - Ultimate Heat Sink for Nuclear Power Plants; Draft Regulatory Guide  

Federal Register 2010, 2011, 2012, 2013

...NRC-2013-0203] Ultimate Heat Sink for Nuclear Power Plants; Draft Regulatory Guide...DG-1275, ``Ultimate Heat Sink for Nuclear Power Plants.'' This regulatory guide...acceptable to the NRC staff that nuclear power plant facility licensees and...

2013-09-09

102

40 CFR 91.1204 - Furnishing of maintenance and use instructions to ultimate purchaser.  

Code of Federal Regulations, 2012 CFR

...2012-07-01 false Furnishing of maintenance and use instructions to ultimate purchaser...SPARK-IGNITION ENGINES Emission Warranty and Maintenance Instructions Ā§ 91.1204 Furnishing of maintenance and use instructions to ultimate...

2012-07-01

103

TOPICAL REVIEW: Ultimate limits to thermally assisted magnetic recording  

NASA Astrophysics Data System (ADS)

The application of thermal energy to enable recording on extremely high anisotropy magnetic media appears to be a viable means of extending the density of stored information. The central physical issue facing the technology is what gain can be realized in writability along with long-term data stability using imaginable media materials. We reasonably expect the material properties M(T) and Hk(T) to determine this, since a stability metric for media with characteristic magnetization switching unit volume V is MV Hk/2kBT. This matter is controversial owing to still open questions related to thermomagnetic recording with temperature elevation above the Curie point and optimal cooling rates. There are indications that multi-component magnetic media may offer advantages in achieving performance goals. Beyond the physical issues lie engineering matters related to the correct system architecture to yield a practical storage device to meet future customer expectations. Here one must address a detailed means of delivering localized heating to the magnetic medium to perform efficient recording. To date, magnetic recording devices have been highly mechanical systems, so it is natural to inquire how a need for an aggressively heated head-medium interface could impact the evolution of future systems. Eventually elements of thermally assisted recording could be combined with patterned media approaches such as self-organized magnetic arrays to push toward ultimate limits where the thermal instability of bits overtakes engineered media materials. Finally, a practical recording system cannot be realized unless a means of finding, following, and reading the smallest bits with a usable signal-to-noise ratio exists—engineering issues separate from an ability to reliably record those bits. This paper is based on an invited presentation of the same title given at the meeting of the American Physical Society, 22-26 March 2004, in Montreal, Quebec, Canada.

McDaniel, Terry W.

2005-02-01

104

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 ...

105

Nano-protoplasm: the ultimate unit of life.  

PubMed

Among the most promising scientific achievements of the 19th century was the recognition that the laws governing the dead world also govern the world of the living and that life has a physical basis called protoplasm. Regrettably, the definition of protoplasm provided then was (inescapably) incorrect, offering a (legitimate) reason for rejecting the concept of protoplasm by an overwhelming majority of later investigators, teachers and other opinion-makers. Without a recognized physical basis, Life itself also faded into the limbo of the unexplainable. However, eventually the needed relevant parts of physics and chemistry to give a more cogent definition of protoplasm became available. That then made possible the construction in the early 1960's of a unifying theory of the living cell, named the association-induction (AI) hypothesis. Historically speaking, the AI Hypothesis is the heir to the general concept of protoplasm as the physical basis of life-incorrect as the initial definition of protoplasm was notwithstanding. In the AI Hypothesis (AIH) the true or ultimate physical basis of life is not what the advocates of the protoplasm once considered as the physical basis of life. What they saw and construed as the physical basis of life is a particular kind of macroscopic protoplasm. In the AI Hypothesis, the basic unit (or physical basis) of life is microscopic protoplasm or nano-protoplasm, of which all macroscopic protoplasm is made. The AI Hypothesis also had no difficulty offering a new definition to what life is in terms of fundamental physical-chemical laws. Nano-protoplasm is defined by what it is and what it does. In greater detail, it is defined (i) by its chemical composition given in Equation 1 on p. 124; (ii) by the mutual spatial and energetic relationships among the components as illustrated diagrammatically in Figure 5 on p. 125; and (iii) by the ability of these components to exist as coherent assemblies in either one of two alternative states, the resting and active living (or dead) state as according to Equation 5 on p. 142. The review then describes the AIH-based electronic and molecular mechanisms for the coherent assemblage of the components, for the maintenance of the living states and for the auto-cooperative transitions between the resting and active (or dead) living state. Having completed the theoretical section, the review goes on to describe the experimental testing of the theory carried out in the past forty-some years (and even in time before that by authors who knew nothing of the theory.) These experimental studies fall into two broad categories. In the first category, are the experiments performed on ultra-simple models of nano-protoplasm made up from pure chemicals as prescribed in Equation 1 on p. 124. The results show that they indeed behave qualitatively like that illustrated in Figure 5 and quantitatively follow the dictates of Equation 5. In the second category of experimental testing, parallel studies were carried out on nano-protoplasm as part of living cells--in carrying out each one of the four classical functions of cell physiology: (1) solute and water distribution; (2) solute and water permeability; (3) cellular resting and action potentials; (4) cellular swelling and shrinkage. The results show that the nano-protoplasm in situ too qualitatively behave like that shown in Figure 5 and quantitatively follow the dictates of Equation 5. The review ends on a discussion section, examining how cogent do the experimental data accumulated thus far support to the AI version of the concept of nano-protoplasm as the most basic unit of life. PMID:19256352

Ling, Gilbert

2007-01-01

106

BOOK REVIEW: Seeking Ultimates. An Intuitive Guide to Physics  

NASA Astrophysics Data System (ADS)

Physics has the reputation of being a difficult and dry subject. Many books have been written in attempts to show that the difficulties are not insurmountable, even for the layman, and to convey some of the fascination it provides for those within it. In Seeking Ultimates Peter Landsberg avoids mathematics, the source of so many difficulties, entirely, and seeks to make physics comprehensible by what he terms intuition. He also emphasizes that there is almost no part of science that is completely understood; there are always areas of incompleteness and uncertainty, capable of providing exciting new results, and examples of this are highlighted throughout the book. After an introduction Landsberg starts with macroscopic phenomena for ease of understanding, though one might question whether the chosen topic of thermodynamics is ever going to be easy. Next he looks at microscopic effects, from atomic structure to the fundamental particles of the standard model and their interactions. There follow chapters on time and entropy, on chaos theory, on quantum mechanics and then cosmology. The final chapters look at physical constants (including the anthropic principle), whether physics has room for a creator God (the conclusion is that this is not the province of science), and some thoughts on science as a human activity. The chosen topics are those which have been important in the late twentieth century and remain important. Each chapter cites an eminent scientist as a `hero', though little is made of this. There are occasional historical notes, set in boxes, and a few short poems to leaven the text. What the book achieves is difficult to assess. Removing mathematics and adding a glossary of technical terms do not necessarily allow non-scientists to enjoy the text, as the publisher's note on the back cover suggests. The concepts can baffle the layman even more than the mathematics, and one of the most difficult of all physical concepts permeates so much of this book: entropy. It is physicists who can benefit most from discarding mathematics and seeking intuitive understanding. It is often too easy to put the numbers into a formula, with little real comprehension of the underlying physics. For layman or physicist the book is hard work. It is not a volume to be read from cover to cover; each section needs to be considered and digested, with frequent turning backwards (or sometimes forwards) to other pages. Even then the outcome may leave questions that can only be answered by access to an academic library to look up some of the copious references to original papers (which, of course, do not eschew mathematics or make concessions to conceptual difficulties). Unfortunately the book is marred by an impression of haste and lack of care, leading to errors that should not have reached the final print. For example, a graph of increase of population with generation number is shown as and stated to be a straight line. It should be exponential. This sort of thing undermines confidence in the whole text. High temperature superconductivity may have a revolutionary effect on electrical machines in the future, but for the time being magnets for magnetic resonance imaging machines and the like still use the old superconductors. Amusing anecdotes make for interesting reading, but the one about Faraday is garbled: he had nothing to do with frogs' legs (that was Galvani), and the quip about taxing electricity one day, if not apocryphal, was made either to Peel or to Gladstone, not to the King. In at least one case a topic mentioned in the index and glossary does not appear on the stated page in the text, apparently having been cut out at a late stage. Personally I did not find the book satisfying, but others will differ. Especially when dealing with intuitive appreciation, what is straightforward to one person may be utterly opaque to another. Making physics comprehensible and conveying its fascination is a daunting and often thankless task, but a very necessary one. The more it is attempted by those with a command of the subject, the more likely i

Brown, Neil

2000-05-01

107

Prediction of the time evolution of pH in meat.  

PubMed

In this paper we compare experimental data on pH decline in carcasses and predictions using a model, based on earlier work of Vetharaniam and coworkers. This model is extended in order to cope with the varying temperatures in the slaughterhouse. We have measured initial glycogen, and the pH and temperature at multiple times in the production chain. We have obtained good comparison between model predictions and our measurements. Furthermore, the correlation between initial glycogen content and ultimate pH as predicted by the model, follows closely experimental data reported earlier in literature. Being able to predict pH decline and ultimate pH, one can obtain reliable indications of final meat quality. PMID:23870969

Hamoen, J R; Vollebregt, H M; van der Sman, R G M

2013-05-24

108

Predicting Ultimate Punching Failure in Concrete Bridge Deck Slabs through Nonlinear Finite Element Analysis  

Microsoft Academic Search

This paper presents an efficient non-linear finite element (NLFEA) model using the commercial FE package ABAQUS to predict the ultimate load behaviour of deck slabs in concrete bridge deck slabs. In order to overcome the instability problems, stabilization methods were adopted and failure criteria were established to capture the ultimate loads. The proposed NLFEA predictions showed a good correlation with

Yu Zheng; D. Robinson; S. Taylor; D. Cleland

2009-01-01

109

Modified Paik–Mansour formula for ultimate strength calculations of ship hulls  

Microsoft Academic Search

The objective of this paper is to develop a modified Paik–Mansour formula for the ultimate strength calculations of ship hulls subject to vertical bending moments. The method is based on a credible bending stress distribution over the hull cross-section presumed at the ultimate limit state. The accuracy of this method is demonstrated through comparison with computations obtained using more refined

J. K. Paik; D. K. Kim; D. H. Park; H. B. Kim; A. E. Mansour; J. B. Caldwell

2012-01-01

110

Numerical analysis of ultimate strength of concrete filled steel tubular arch bridges  

Microsoft Academic Search

The calculation of ultimate bearing capacity is a significant issue in the design of Concrete Filled Steel Tubular (CFST) arch bridges. Based on the space beam theory, this paper provides a calculation method for determining the ultimate strength of CFST structures. The accuracy of this method and the applicability of the stress-strain relationships were validated by comparing different existing confined

XIE Xu; CHEN Heng-zhi; LI Hui; SONG Shi-rui

111

Empirical research on turnarounds of financial distress firms based on ultimate control  

Microsoft Academic Search

Using a firm-level dataset of financial distress firms from China's A-share stock market over the period of 2001-2004, this paper examines the effects of ultimate control rights, cash flow rights and nature of property rights on turnaround of financial distress firms. We find that both ultimate control rights and cash flow rights are associated with positive \\

Yao Zheng; Jin Tian; Tang Yan-feng; Sun Yan

2009-01-01

112

Primary and ultimate biodegradabilities of mineral base oils and their relationships with oil viscosity  

Microsoft Academic Search

We have determined the primary and ultimate biodegradabilities of a series of paraffinic base oils representative of the main classes that are used for the production of lubricating oils, such as engine, industrial, and marine oils. Primary and ultimate biodegrability (B) data were determined using the CEC test and the modified Sturm test (OECD 301B), respectively. There was a strong

F. Haus; O. Boissel; G.-A. Junter

2004-01-01

113

Evaluation of ultimate capacity of semi-supported steel shear walls  

Microsoft Academic Search

In this paper, the semi-supported steel shear wall (SSSW) that has been proposed as an alternative to the traditional type of steel shear wall is introduced. The problem of calculating the ultimate capacity of shear walls (with emphasis on its semi-supported type) is addressed. A new method for evaluating the ultimate shear capacity of given SSSW especially when it undergoes

A. Jahanpour; H. Moharrami; A. Aghakoochak

2011-01-01

114

Prediction of FRP-concrete ultimate bond strength using Artificial Neural Network  

Microsoft Academic Search

The ultimate bond strength between Fiber Reinforced Polymers (FRP) and concrete is one of the most important elements in the performance of the strengthened beam and its failure mode and failure mechanism. In this investigation an Artificial Neural Network (ANN) model has been developed to predict the ultimate bond strength (Pu) between FRP and concrete based on several factors that

Jamal A. Abdalla; Rami Hawileh; Adil Al-Tamimi

2011-01-01

115

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

116

Direct reduction of N-acetoxy-PhIP by tea polyphenols: a possible mechanism for chemoprevention against PhIP-DNA adduct formation.  

PubMed

The chemopreventive effect of tea against 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP)-DNA adduct formation and its mechanism were studied. Rats were exposed to freshly prepared aqueous extracts of green tea (3% (w/v)) as the sole source of drinking water for 10 days prior to administration with a single dose of PhIP (10 mg/kg body weight) by oral gavage. PhIP-DNA adducts in the liver, colon, heart, and lung were measured using the 32P-postlabelling technique. Rats pre-treated with tea and given PhIP 20 h before sacrifice had significantly reduced levels of PhIP-DNA adducts as compared with controls given PhIP alone. The possible mechanism of protective effect of tea on PhIP-DNA adduct formation was then examined in vitro. It was found that an aqueous extract of green and black tea, mixtures of green and black tea polyphenols, as well as purified polyphenols could strongly inhibit the DNA binding of N-acetoxy-PhIP, a putative ultimate carcinogen of PhIP formed in vivo via metabolic activation. Among these, epigallocatechin gallate was exceptionally potent. HPLC analyses of these incubation mixtures containing N-acetoxy-PhIP and the tea polyphenols each revealed the production of the parent amine, PhIP, indicating the involvement of a redox mechanism. In view of the presence of relatively high levels of tea polyphenols in rat and human plasma after ingestion of tea, this study suggests that direct reduction of the ultimate carcinogen N-acetoxy-PhIP by tea polyphenols is likely to be involved in the mechanism of chemoprotection of tea against this carcinogen. PMID:12628517

Lin, Dong-Xin; Thompson, Patricia A; Teitel, Candee; Chen, Jun-Shi; Kadlubar, Fred F

117

Ionizable drugs and pH oscillators: buffering effects.  

PubMed

It has been proposed that chemical pH oscillators may form a basis for periodic, pulsed drug delivery of weak acids and bases across lipophilic membranes. However, drugs have been shown to interfere with the ability of the chemical systems to oscillate, and rhythmic delivery of drugs by this means has been demonstrated only under constrained circumstances. Herein, we provide evidence that low concentrations of acidic drugs can attenuate and ultimately quench chemical pH oscillators, by a simple buffering mechanism. A model system consisting of the bromate-sulfite-marble pH oscillator in a continuous stirred tank reactor is used, along with acidic drugs of varying concentration and acid dissociation constant, pK(D). A published kinetic model for this oscillator is modified to account for the presence of acidic drug, and the results of this model are in qualitative agreement with the experimental results. PMID:12210047

Misra, Gauri P; Siegel, Ronald A

2002-09-01

118

METHYLATED ASIII COMPOUNDS AS POTENTIAL PROXIMATE/ULTIMATE GENOTOXIC METABOLITES OF INORGANIC ARSENIC  

EPA Science Inventory

METHYLATED Asm COMPOUNDS AS POTENTIAL PROXIMATE/ULTIMATE GENOTOXIC METABOLITES OF INORGANIC ARSENIC. The methylation of inorganic arsenic has typically been viewed as a detoxification process. Genotoxicity tests have generally shown that arsenite has greater mutagenic p...

119

The effect of pH on shelf-life of pork during aging and simulated retail display  

Microsoft Academic Search

The pork industry uses pH to differentiate product of varying quality; thus, the effect of pH on shelf-life is important as time during transport is extended. The objective was to develop regression equations to predict shelf-life over a range of ultimate pH (5.42–6.26). Shelf-life was evaluated after vacuum aging pork loin sections 0, 7, 14, 21, or 28d and during

S. F. Holmer; R. O. McKeith; D. D. Boler; A. C. Dilger; J. M. Eggert; D. B. Petry; F. K. McKeith; K. L. Jones; J. Killefer

2009-01-01

120

Effect of muscle-fiber type on glycogenin-1 gene expression and its relationship with the glycolytic potential and pH of pork.  

PubMed

This study analyzed the effect of muscle-fiber type composition on glycogenin-1 (GYG) gene expression and its impact on pH. The longissimus dorsi (LD) muscle contains more type IIB fibers (75.10%) than does the psoas major (PM) muscle (41.58%), while the PM has more type I (3.65 vs 0.94%), type IIA (34.15 vs 10.63%), and type IIX (20.62 vs 13.33%) fibers. Compared with PM, glycolytic potential (GP), pH45 min, and ?pH from 45 min to 24 h post-mortem were all relatively higher in LD. Glycogen metabolites (lactate and GP) were negatively correlated with pH24 h and positively correlated with ?pH. Expression of GYG was generally higher in LD. GYG expression was positively correlated with glycogen metabolite (lactate and GP) content and ?pH, and was negatively correlated with pH24 h. These data confirm that the muscle-fiber type and GP have significant effects on ultimate pH and pH decline, and suggest that expression of GYG in muscles is related to the metabolism of glycogen and may impact GP, ?pH, and ultimate pH. High expression of GYG was associated with a high glycogen content, large pH decline, and low ultimate pH in muscles post-mortem. PMID:24065679

Zhang, S-H; Zhu, L; Wu, Z-H; Zhang, Y; Tang, G-Q; Jiang, Y-Z; Li, M-Z; Bai, L; Li, X-W

2013-09-04

121

Ultimate strength of girders with trapezoidally corrugated webs under patch loading  

Microsoft Academic Search

Ultimate strength of steel plate girders with trapezoidally corrugated webs under patch loading is studied using a non-linear finite element method. Effect of large deflection is taken into account and a von Mises material either without strain hardening (elastic-perfectly plastic), or with strainhardening obeying Ramberg-Osgood's equation, is assumed. The following factors that influence the ultimate strength are investigate (1) strainhardening

R. Luo; B. Edlund

1996-01-01

122

Diverse lamb genotypes—2. Meat pH, colour and tenderness  

Microsoft Academic Search

The effect of genotype on meat ultimate pH, colour and tenderness was studied in 3 experiments involving 436 lambs. The lambs were sired by a selection of Texel (T), Poll Dorset (PD), Border Leicester (BL) and Merino (M) rams, crossed with Border Leicester × Merino (BLM) and Merino (M) ewes giving 6 genotypes (T × BLM, PD × BLM, T

D. L. Hopkins; N. M. Fogarty

1998-01-01

123

Evaluation of QTL for carcass merit and meat quality traits in a US commercial Duroc population.  

PubMed

Putative quantitative trait loci (QTL) regions on 5 chromosomes (SSC3, 6, 12, 15, and 18) were selected from our previous genome scans of a Duroc×Pietrain F(2) resource population for further evaluation in a US commercial Duroc population (n=331). A total of 81 gene-specific single nucleotide polymorphism (SNP) markers were genotyped and 33 markers were segregating. The MDH1 SNP on SSC3 was associated with 45-min and ultimate pH (pHu), and pH decline. PRKAG3 on SSC15 was associated with pHu. The HSPG2 SNP on SSC6 was associated with marbling score and days to 113kg. Markers for NUP88 and FKBP10 on SSC12 were associated with 45-min pH and L*, respectively. The SSC15 marker SF3B1 was associated with L* and LMA, and the SSC18 marker ARF5 was associated with pHu and color score. These results in a commercial Duroc population showed a general consistency with our previous genome scan. PMID:22578477

Choi, Igseo; Bates, Ronald O; Raney, Nancy E; Steibel, Juan P; Ernst, Catherine W

2012-04-21

124

Intra-Beam Scattering, Impedance, and Instabilities in Ultimate Storage Rings  

SciTech Connect

We have investigated collective effects in an ultimate storage ring, i.e. one with diffraction limited emittances in both planes, using PEP-X as an example. In an ultimate ring intra-beam scattering (IBS) sets the limit of current that can be stored. In PEP-X, a 4.5 GeV ring running round beams at 200 mA in 3300 bunches, IBS doubles the emittances to 11.5 pm at the design current. The Touschek lifetime is 11 hours. Impedance driven collective effects tend not to be important since the beam current is relatively low. We have investigated collective effects in PEP-X, an ultimate storage ring, i.e. one with diffraction limited emittances (at one angstrom wavelength) in both planes. In an ultimate ring intra-beam scattering (IBS) sets the limit of current that can be stored. In PEP-X, IBS doubles the emittances to 11.5 pm at the design current of 200 mA, assuming round beams. The Touschek lifetime is quite large in PEP-X, 11.6 hours, and - near the operating point - increases with decreasing emittance. It is, however, a very sensitive function of momentum acceptance. In an ultimate ring like PEP-X impedance driven collective effects tend not to be important since the beam current is relatively low. Before ultimate PEP-X can be realized, the question of how to run a machine with round beams needs serious study. For example, in this report we assumed that the vertical emittance is coupling dominated. It may turn out that using vertical dispersion is a preferable way to generate round beams. The choice will affect IBS and the Touschek effect.

Bane, Karl; /SLAC

2012-03-28

125

Fiber/matrix interfacial bond ultimate and fatigue strength characterization in a 37 C dry environment  

SciTech Connect

The ultimate and fatigue strengths of the fiber/matrix interfacial bond of four fiber/matrix combinations (fiber: carbon, polyaramid; matrix: polysulfone, polycarbonate) have been quantitatively investigated in a dry 37 C environment using a microbond single fiber pull-out test method. Fatigue testing was conducted at 1 Hz using a sinusoidally varying applied load. Each sample type exhibited a linear relationship between peak applied interfacial shear stress and the logarithm of fatigue life. Interfacial bond fatigue behavior is apparently significantly influenced by both matrix viscoelastic behavior and fiber/matrix interfacial bond ultimate strength. 29 refs.

Latour, R.A., JR.; Black, J.; Miller, B. (Clemson University, SC (United States) Textile Research Institute, Princeton, Il (United States))

1992-01-01

126

The cost benefit and efficiency of waste water treatment using domestic ponds—the ultimate solution in Southern Africa  

NASA Astrophysics Data System (ADS)

Wastewater treatment has become a challenge to most countries in Southern Africa because of the fluctuating economies that have been hit by high levels of debts. The treatment of domestic wastewater using ponds, if carefully utilized, as has been observed in most countries in the world, is the most cost effective means of handling wastewaters. When compared to the conventional use of treatment plants, the ponds have been observed to be the ultimate solution for the countries in Southern Africa especially those that are classified as Highly Indebted Poor Countries (HIPC) because of little or no operating costs associated with the treatment. The study conducted on Kitwe Waste Water Treatment Ponds to evaluate the cost benefit and efficiencies has revealed low levels of operating cost and high removal efficiencies of oxygen demanding wastes (BOD removal of 86% and TSS removal of 75%), pH values ranged from 7 to 8 indicating an increasing alkalinity from facultative to maturation ponds while other parameters such as nitrates, phosphates and temperature were found to be within acceptable levels thereby releasing effluent that makes the environment sustainable. The overall social benefit was found to be much higher than the operating costs.

Ntengwe, F. W.

127

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

128

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

129

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

130

The Potential of an Ultimate Storage Ring for Future Light Sources  

SciTech Connect

This paper is the report of the working group on Ultimate Storage Rings at the Department of Energy's Basic Energy Sciences Workshop on Physics of Future Light Sources, which took place in Gaithersburg, Maryland on September 15–17, 2009. In this report we address the accelerator design issues related to the next generation of storage ring light sources, deemed “ultimate” storage rings. In our estimation, storage rings have the potential to provide an increase in photon brightness and coherent flux that is two orders of magnitude above that projected for rings currently under construction. In addition to photon brightness and coherent flux, we discuss other directions, such as shorter pulses, tailored bunches, and partial lasing, in which rings could evolve. For the most part we envision ultimate storage rings as an evolutionary advance from existing rings that faces no fundamental technological obstacles. Nevertheless we identify several important areas of R&D that should be pursued to enable the realization of the full potential of ultimate ring light sources.

Bei, M; Cai, Y; Elleaume, P; Gerig, R; Harkay, K; Emery, L; Hutton, A; Hettel, R; Nagaoka, R; Robin, D

2010-10-01

131

Methods for ultimate load analysis of concrete containments: Second phase: Interim report  

Microsoft Academic Search

This summary report gives an overview of research on the influence of special effects on the ultimate load behavior of concrete containment structures. The special effects analyses that were performed include containment response under combined pressure and temperature, shear dislocation at a major concrete crack, wall discontinuity at the wall-basemat juncture, flawed liner, and thermal buckling. The EPRI-sponsored finite element

R. A. Dameron; R. S. Dunham; Y. R. Rashid

1987-01-01

132

Ultimate analysis of BWR Mark III reinforced concrete containment subjected to internal pressure  

Microsoft Academic Search

Numerical analyses are carried out by using the ABAQUS finite element program to predict the ultimate pressure capacity and the failure mode of the BWR Mark III reinforced concrete containment at Kuosheng Nuclear Power Plant, Taiwan, R.O.C. Material nonlinearity such as concrete cracking, tension stiffening, shear retention, concrete plasticity, yielding of reinforcing steel, yielding of liner plate and degradation of

Hsuan-Teh Hu; Jiin-Iuan Liang

2000-01-01

133

Ultimate analysis of PWR prestressed concrete containment subjected to internal pressure  

Microsoft Academic Search

Numerical analyses are carried out by using the ABAQUS finite element program to predict the ultimate pressure capacity and the failure mode of the PWR prestressed concrete containment at Maanshan nuclear power plant. Material nonlinearity such as concrete cracking, tension stiffening, shear retention, concrete plasticity, yielding of prestressing tendon, yielding of steel reinforcing bar and degradation of material properties due

Hsuan-Teh Hu; Yu-Hon Lin

2006-01-01

134

FUTURE OF NEW MEDIA, TOWARDS THE ULTIMATE MEDIUM: PRESENCE, IMMERSION and MMORPGs  

Microsoft Academic Search

Revolutionary developments in communication and information technologies, coupled with the transition from traditional media into new media, create new mediums of the information age which are capable of offering interactive user participation in communication processes. Frontiers of these new mediums are virtual reality technologies which can be considered as the ultimate form of interaction between humans and machines, and sometimes

Barbaros BOSTAN

135

Ultimate doctor liability: A myth of ignorance or myth of control?  

Microsoft Academic Search

Ultimate medical doctor responsibility for the care delivered to patients by all professionals is a myth. Legally Lord Denning dismissed the myth in the mid-20th century in England. The assumption that a medical doctor is responsible for the care delivered by nurses has not existed in English and Australian law since that time, and it has been actively refuted. Yet

Andrew J Cashin; Michael Carey; Ngaire Watson; Greg Clark; Claire Newman; Cheryl D. Waters

2009-01-01

136

Experiences with ANSYS in Ultimate-Load Analyses of Aircraft Fuselage Panels  

Microsoft Academic Search

Wider parts of the fuselage of a commercial aircraft are subject to shear and compression loads in such a way that this is relevant for dimensioning. First elastic, later plastic buckling can appear. The ultimate load is reached when a combined buckling of skin and longitudinal reinforcements (stringers) leads to failure of a panel. This behavior is tested physically, but

Wilhelm Rust; Martin Kracht; Josef Overberg

137

Ultimate strength model experiment regarding a container ship’s hull structures  

Microsoft Academic Search

The results of an experimental investigation into the ultimate hogging strength of a container ship’s hull structures are presented. On the basis of derived similar conversion relationships, a test model is designed to reflect the possible failure modes under hogging moment. Comparisons between the container ship and test model are carried out by linear analysis, non-linear finite element analysis and

Shi Gui-Jie; Wang De-Yu

2012-01-01

138

The effect of repeated torque on the ultimate tensile strength of slotted gold prosthetic screws  

Microsoft Academic Search

Statement of Problem. Repeated torque may alter the mechanical properties and fracture resistance of certain prosthetic retaining screws. Purpose. This study evaluated the effect of repeated torque and salivary contamination on the ultimate tensile strength of one type of slotted gold prosthetic retaining screw. Material and Methods. Forty-five slotted gold prosthetic screws from the same manufacturer (Implant Innovations) were divided

Mohammed A. Al Rafee; William W. Nagy; Raymond A. Fournelle; Virendra B. Dhuru; George K. Tzenakis; Charles E. Pechous

2002-01-01

139

Effect of Soil Confinement on Ultimate Bearing Capacity of Square Footing Under Eccentric-Inclined Load  

Microsoft Academic Search

This paper presents the results of laboratory model tests on the effect of soil confinement on the behavior of a model footing resting on Ganga sand under eccentric - inclined load. Confining cells with different heights and widths have been used to confine the sand. The ultimate bearing load of a square footing supported on a confined sand bed has

Vinod Kumar Singh; Arun Prasad; R. K. Agrawal

140

Seismic Proving Test of Ultimate Piping Strength: Current Status of Preliminary Tests - II  

Microsoft Academic Search

In 1998 FY, the 6 year program of piping tests was initiated with the following objectives: i) to clarify the elasto-plastic response and ultimate strength of nuclear piping, ii) to ascertain the seismic safety margin of the current seismic design code for piping, and iii) to assess new allowable stress rules. In order to resolve extensive technical issues before proceeding

Kenichi Suzuki; Y. Namita; H. Abe; I. Ichihashi; Kohei Suzuki; M. Ishiwata; T. Fujiwaka; H. Yokota

2002-01-01

141

Physical Processes in the Solar Interior: the Ultimate Sun-Weather Engine  

Microsoft Academic Search

The ultimate source of the magnetic fields that drive the Sun-Weather is located in the solar interior, where the dynamo mechanism (or mechanisms) operate. To model these processes, it is necessary to combine the tools of plasma physics (MHD) together with those of stellar structure and evolution, and large eddy simulations (LES) of the convective envelope. Because of the differences

S. Sofia

2004-01-01

142

Joint implementation and the ultimate objective of the United Nations Framework Convention on Climate Change  

Microsoft Academic Search

This paper critically assesses the potential role of joint implementation (JI) in contributing to the achievement of the ultimate objective of the United Nations Framework Convention on Climate Change, namely, the stabilization of atmospheric greenhouse gas concentrations at levels which are non-threatening to human societies and ecosystems. This requires, among other actions, a 50% reduction in CO2 emissions within the

Elizabeth J Bush; LD Danny Harvey

1997-01-01

143

Prisoner Fasting as Symbolic Speech: The Ultimate Speech-Action Test.  

ERIC Educational Resources Information Center

|The ultimate test of the speech-action dichotomy, as it relates to symbolic speech to be considered by the courts, may be the fasting of prison inmates who use hunger strikes to protest the conditions of their confinement or to make political statements. While hunger strikes have been utilized by prisoners for years as a means of protest, it was…

Sneed, Don; Stonecipher, Harry W.

144

Ultimate strength of a steel–concrete composite bridge deck slab with profiled sheeting  

Microsoft Academic Search

The ultimate behaviour of a steel–concrete composite deck slab system with profiled steel sheeting and perfobond rib shear connectors was experimentally investigated. The main objectives of this study are to develop a composite deck slab for girder bridges that spans longer but weighs less than the conventional reinforced concrete (RC) deck slab and to experimentally validate the proposed deck slab

Hyeong-Yeol Kim; Youn-Ju Jeong

2010-01-01

145

Ultimate Performance of the Fixed-Beacon Position-Finding System.  

National Technical Information Service (NTIS)

The results obtained for analyzing the ultimate performance of the Eole position-finding system for fixed beacons are presented in synthesis. With the use of up-to-date equipment (Baker Nunn cameras) and sophisticated programming, this performance was sho...

G. B. Rachet J. L. Pieplu

1974-01-01

146

Collective quantum tunneling, ultimate sensitivity of the AC SQUID, and all that  

Microsoft Academic Search

The effect of quantum tunneling of the phase variable in SQUIDs is studied as a source of zero-temperature noise in the system. It is concluded that quantum tunneling plays no role in the ultimate uncertainty principle limitation of SQUID resolution. A simple expression is derived for the latter in practical SQUIDs.

J. Kurkijärvi

1981-01-01

147

Student's Ultimate Career Coursework, Employment, & Student Services Handbook. "SUCCESS Handbook" Final Report.  

ERIC Educational Resources Information Center

|The Student's Ultimate Career Coursework, Employment and Student Services (SUCCESS) Handbook project was undertaken to identify student support services available through the California Community Colleges (CCC), increase student retention among special needs vocational education students, and identify common barriers to employment. The project…

Foothill-De Anza Community Coll. District, Cupertino, CA. Occupational Training Inst.

148

Application of artificial neural networks to evaluation of ultimate strength of steel panels  

Microsoft Academic Search

Structural design of ships and offshore structures has been moving towards limit state design or reliability-based design. Improving the accuracy and efficiency of predicting the ultimate strength of structural components, such as unstiffened panels and stiffened panels, has a significant impact on our daily structural design. Empirical formulations have been widely used because of their simplicity and reasonable accuracy. In

Yongchang Pu; Ehsan Mesbahi

2006-01-01

149

Method for ultimate disposition of borate containing radioactive wastes by vitrification  

US Patent & Trademark Office Database

Method for the ultimate disposition of radioactive wastes by vitrification, in which weak to medium radioactive waste concentrates from borate-containing radioactive liquids are mixed with added glass-forming materials, maximally in a ratio of 1:3, and the mixture heated to obtain a glass-forming melt.

Bege; Dietmar (Erlangen, DE); Faust; Hans-Joachim (Grossgeschaid, DE); Puthawala; Anwer (Erlangen, DE); Stu/ nkel; Helmut (Erlangen, DE)

1984-01-03

150

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

151

In Vitro Colonization of the Muscle Extracellular Matrix Components by Escherichia coli O157:H7: The Influence of Growth Medium, Temperature and pH on Initial Adhesion and Induction of Biofilm Formation by Collagens I and III  

PubMed Central

Enterohemorrhagic Escherichia coli (EHEC) O157:H7 are responsible for repeated food-poisoning cases often caused by contaminated burgers. EHEC infection is predominantly a pediatric illness, which can lead to life-threatening diseases. Ruminants are the main natural reservoir for EHEC and food contamination almost always originates from faecal contamination. In beef meat products, primary bacterial contamination occurs at the dehiding stage of slaughtering. The extracellular matrix (ECM) is the most exposed part of the skeletal muscles in beef carcasses. Investigating the adhesion to the main muscle fibrous ECM proteins, insoluble fibronectin, collagen I, III and IV, laminin-?2 and elastin, results demonstrated that the preceding growth conditions had a great influence on subsequent bacterial attachment. In the tested experimental conditions, maximal adhesion to fibril-forming collagens I or III occurred at 25°C and pH 7. Once initially adhered, exposure to lower temperatures, as applied to meat during cutting and storage, or acidification, as in the course of post-mortem physiological modifications of muscle, had no effect on detachment, except at pHu. In addition, dense biofilm formation occurred on immobilized collagen I or III and was induced in growth medium supplemented with collagen I in solution. From this first comprehensive investigation of EHEC adhesion to ECM proteins with respect to muscle biology and meat processing, new research directions for the development of innovative practices to minimize the risk of meat contamination are further discussed.

Chagnot, Caroline; Agus, Allison; Renier, Sandra; Peyrin, Frederic; Talon, Regine; Astruc, Thierry; Desvaux, Mickael

2013-01-01

152

pH control mechanisms of tumor survival and growth.  

PubMed

A distinguishing phenotype of solid tumors is the presence of an alkaline cellular feature despite the surrounding acidic microenvironment. This phenotypic characteristic of tumors, originally described by Otto Warburg, arises due to alterations in metabolism of solid tumors. Hypoxic regions of solid tumors develop due to poor vascularization and in turn regulate the expression of numerous genes via the transcription factor HIF-1. Ultimately, the tumor microenvironment directs the development of tumor cells adapted to survive in an acidic surrounding where normal cells perish. The provision of unique pH characteristics in tumor cells provides a defining trait that has led to the pursuit of treatments that target metabolism, hypoxia, and pH-related mechanisms to selectively kill cancer cells. Numerous studies over the past decade involving the cancer-specific carbonic anhydrase IX have re-kindled an interest in pH disruption-based therapies. Although an acidification of the intracellular compartment is established as a means to induce normal cell death, the defining role of acid-base disturbances in tumor physiology and survival remains unclear. The aim of this review is to summarize recent data relating to the specific role of pH regulation in tumor cell survival. We focus on membrane transport and enzyme studies in an attempt to elucidate their respective functions regarding tumor cell pH regulation. These data are discussed in the context of future directions for the field of tumor cell acid-base-related research. PMID:20857482

Parks, Scott K; Chiche, Johanna; Pouyssegur, Jacques

2011-02-01

153

Application of SERS Nanoparticles for Intracellular pH Measurements  

SciTech Connect

We present an alternative approach to optical probes that will ultimately allow us to measure chemical concentrations in microenvironments within cells and tissues. This approach is based on monitoring the surface-enhanced Raman scattering (SERS) response of functionalized metal nanoparticles (50-100 nm in diameter). SERS allows for the sensitive detection of changes in the state of chemical groups attached to individual nanoparticles and small clusters. Here, we present the development of a nanoscale pH meter. The pH response of these nanoprobes is tested in a cell-free medium, measuring the pH of the solution immediately surrounding the nanoparticles. Heterogeneities in the SERS signal, which can result from the formation of small nanoparticle clusters, are characterized using SERS correlation spectroscopy and single particle/cluster SERS spectroscopy. The response of the nanoscale pH meters is tested under a wide range of conditions to approach the complex environment encountered inside living cells and to optimize probe performance.

Laurence, T; Talley, C; Colvin, M; Huser, T

2004-10-21

154

Exercise and Pulmonary Hypertension (PH)  

MedlinePLUS

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

155

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

156

Ultimate, provisional, and personal meaning of life: differences and common ground.  

PubMed

Building on Viktor Frankl's clinical approach of Logotherapy and the works of subsequent theoreticians, three types of meaning of life were theoretically derived and empirically investigated, Ultimate, Provisional, and Personal meaning. These types were characterized, first, by the amount of agreement of subjects, second, by sources of Life Meaning, which were assessed by content analyses, third, by correlations, and fourth by prediction with ratings of important life concepts from the domains of Well-being, Religiosity, and Prosocial Behavior. 192 German adults, 45 men and 147 women, whose M age was 31.6 yr. (SD = 11.9), participated. Analysis indicated different sources for the Ultimate meaning compared with the other meaning types, which seem to display more similarities with each other. Other important life concepts, such as Belief, Harmony, Happiness, and Human Goodness were related to the investigated types of meaning of life. Some implications for clinical applications, research perspectives, and Positive Psychology are discussed. PMID:17037460

Auhagen, Ann Elisabeth; Holub, Franziska

2006-08-01

157

Ultimate strength assessment of a tanker hull based on experimentally developed master curves  

NASA Astrophysics Data System (ADS)

A geometrically similar scaling was made from small-scale specimen to full-scale stiffened panels and then their collapse behaviour is investigated. It is considered that the stiffened panel compressive ultimate strength test was designed according to geometrical scaling laws so that the output of the test could be used as representative of the stiffened panels of the compressive zone of a tanker hull subjected to vertical bending moment. The ultimate strength of a tanker hull is analysed by a FE analysis using the experimentally developed master stress-strain curves which are obtained by the beam tension test and the compressive test of the stiffened panel, and are then compared with the result achieved by the progressive collapse method.

Xu, Mingcai; Garbatov, Y.; Guedes Soares, C.

2013-06-01

158

UHS. Ultimate Heat Sink Cooling Pond and Spray Pond Analysis Models  

SciTech Connect

Three programs model performance of an ultimate heat sink cooling pond. National Weather Service data is read and analyzed to predict periods of lowest cooling performance and highest evaporative loss. The data is compared to local site data for significant differences. Then the maximum pond temperature is predicted. Five programs model performance of an ultimate heat sink spray pond. The cooling performance, evaporative water loss, and drift water loss as a function of windspeed are estimated for a spray field. These estimates are used in conjunction with National Weather Service data to predict periods of lowest cooling performance and highest evaporative loss. This data is compared to local site data for significant differences. Then the maximum pond temperature is predicted.

Codell, R.; Nuttle, W.K. [US Nuclear Regulatory Commission, Washington, DC (United States)

1980-01-01

159

Prototype impact tests on ultimate impact resistance of PC rock-sheds  

Microsoft Academic Search

To confirm the ultimate impact-resistant capacity of Prestressed Concrete (PC) rock-sheds constructed over the highways in Japan, prototype impact tests are conducted by using two types of PC rock-shed frames: inverted L frame and fully rigid frame. The two types are of equal dimensions: span length=10.1m, upper flange width=150cm, column height=4.65m. The impact tests are performed by iteratively and freely

N. Kishi; H. Konno; K Ikeda; K. G Matsuoka

2002-01-01

160

Fiber\\/Matrix Interfacial Bond Ultimate and Fatigue Strength Characterization in a 37°C Dry Environment  

Microsoft Academic Search

The ultimate and fatigue strengths of the fiber\\/matrix interfacial bond of four fiber\\/matrix combinations (fiber: carbon, polyaramid; matrix: polysulfone, polycar bonate) have been quantitatively investigated in a dry 37°C environment using the TRI microbond single fiber pull-out test method. Fatigue testing was conducted at 1 Hz using a sinusoidally varying applied load. Each sample type exhibited a linear relationship be

R. A. Latour; J. Black; B. Miller

1992-01-01

161

Ultimate Regime of Convection: robustness to poor thermal properties of the plates  

Microsoft Academic Search

A transition to Kraichnan ultimate regime of convection has been reported in\\u000avery high Rayleigh numbers experiments, but not in all of them. These\\u000aapparently contradictory results can be explained by a recent phenomenological\\u000amodel which accounts for the non-ideality of the plate thermal properties\\u000a[Chill\\\\`{a} et al, Physics of Fluids 16:2452 (2004)]. In this paper, we present\\u000aa direct

Philippe-Emmanuel P.-E. Roche; Frédéric Gauthier; Benoīt Chabaud; B. Hebral

2005-01-01

162

Approach for analyzing the ultimate strength of concrete filled steel tubular arch bridges with stiffening girder  

Microsoft Academic Search

A convenient approach is proposed for analyzing the ultimate load carrying capacity of concrete filled steel tubular (CFST)\\u000a arch bridge with stiffening girders. A fiber model beam element is specially used to simulate the stiffening girder and CFST\\u000a arch rib. The geometric nonlinearity, material nonlinearity, influence of the construction process and the contribution of\\u000a prestressing reinforcement are all taken into

Zhi-cheng Zhang; Xu Xie; He Zhang; Heng-zhi Chen

2007-01-01

163

Comparative study of ultimate hull girder strength of large double hull tankers  

Microsoft Academic Search

A systematic study of theoretical methods for predicting the ultimate hull girder strength of ships is carried out based on long-time theoretical and experimental work in authors group. An integrated framework of non-linear finite element analysis, a locally improved idealized structural unit method (ISUM), a simplified method (SM) in which average stress–strain relationship is derived using beam-column theory, along with

Enrong Qi; Weicheng Cui; Zhengquan Wan

2005-01-01

164

High energy radiation effects on ultimate mechanical properties and fractography of nylon 6 fibres  

Microsoft Academic Search

Nylon 6 fibres were irradiated with up to 60 Mrad of cobalt-60 gamma radiation in air or up to 76µC of 4.5 MeV cyclotron-accelerated protons in vacuum. The products of the irradiations were then characterized by the resulting changes in ultimate mechanical properties and in fracture morphology when tested at 21° C under selected conditions of fibre moisture content. In

M. S. Ellison; S. H. Zeronian; Y. Fujiwara

1984-01-01

165

Dependence of fatigue limit of high-tension bolts on mean stress and ultimate tensile strength  

Microsoft Academic Search

High tension bolts in critical joints in internal combustion engines are susceptible to fatigue failure. Computeraided bolted\\u000a joint design procedures require knowledge of the dependence of bolt fatigue limit on the mean stress and ultimate tensile\\u000a strength. This dependence is investigated with staircase fatigue limit tests. The test results show that when the bolt fatigue\\u000a limit is estimated with the

S.-S. Cho; H. Chang; K. W. Lee

2009-01-01

166

A statistical approach to the analysis of ultimate strengths of bolted joints in laminated composites  

Microsoft Academic Search

The general linear models (GLM) routine in the statistical software package SAS has been utilized to develop a statistical model for the prediction of joint failure in single-shear joints in IM7\\/8551 graphite\\/epoxy laminates on the basis of the results of an extensive bolted-joint strength testing program. Ultimate joint strength values from the experimental study were utilized as input for the

K. C. Schulz; H. J. Hietala; P. F. Packman

1996-01-01

167

The ultimate safe (US) Reactor: A concept for the third millenium  

SciTech Connect

The Ultimate Safe (U.S.) Reactor is based on a novel safety concept. Fission products in the reactor are allowed to accumulate only to a level at which they would constitute a harmless source term. Removal of fission products also removes the decay heat - the driving force for the source term. The reactor has no excess criticality and is controlled by the reactivity temperature coefficient. Safety is inherent and passive. Waste is removed from the site promptly.

Gat, U.

1986-01-01

168

Influence of Bolting Parameters on the Ultimate Tensile Strength and Stiffness of Composite-Metal Joints  

Microsoft Academic Search

The joining of dissimilar materials poses a challenge in mechanical structures. The objective of this research was to investigate the effect of joining parameters such as bolt spacing, geometry configuration, and overlap length on ultimate failure strength and stiffness of composite-metal hybrid joints. Woven fiberglass\\/epoxy and unidirectional carbon-fiber\\/epoxy composites have been manufactured and tested under tensile loads to obtain their

William S. Slovinsky; Parsaoran Hutapea

2010-01-01

169

Correlation between fatigue limit, ultimate strength and other mechanical characteristics of steels and alloys  

Microsoft Academic Search

1.The fatigue limit s-1 correlates more closely with the ultimate strength than with other strength characteristic2.In a number of very important cases (variation in temperature of the medium, tempering temperature, degree of work hardening, etc.) there is a linear relationship between s-1 and sb. Evaluation of s-1 on the basis of this realationship leads to fever than when assuming the

A. Buch

1962-01-01

170

Estimation of ultimate state of metal structures exploited in the environment of the extreme north  

Microsoft Academic Search

A method is described for estimating the ultimate state of structural materials in terms of variations of microhardness. The\\u000a method includes investigations of the effect of low temperatures on the strength of cracked specimens made of grade 16G2SAF\\u000a steel, as well as tests on low-cyclic fatigue of specimens made of grade 15 steel. After cyclic stressing, the specimens are\\u000a exposed

A. R. Ivanov; A. M. Bolshakov; A. V. Lyglaev

2010-01-01

171

Human being transcending itself: Creative process in art as a model of our relation to the ultimate reality  

Microsoft Academic Search

The paper reviews some of the links between the notion of “ultimate reality” and everyday life, mainly art, beauty, the creative\\u000a processes in art, and citizenship. If, according to M. Heidegger, art reveals the truth of being (i.e., also of ultimate reality),\\u000a then we may find some historical descriptions of creative processes that are very close to descriptions of ultimate

Erich Mistrķk

2011-01-01

172

Alkaline-induced unfolding and salt-induced folding of pig heart lactate dehydrogenase under high pH conditions  

Microsoft Academic Search

The alkaline-induced unfolding and the salt-induced folding of pig heart lactate dehydrogenase under high pH conditions have been followed by fluorescence emission spectra and circular dichroism spectra. The results for alkaline-induced denaturation of lactate dehydrogenase show that at low ionic strength, increasing the pH value increased the extent of unfolding of the enzyme to the maximum ultimate unfolded conformation at

Ji-Hong Bai; Hao-Jing Wang; Hai-Meng Zhou

1998-01-01

173

Hundredth molar calcium chloride extraction procedure. part II: Calibration with conventional soil testing methods for pH  

Microsoft Academic Search

Soil pH is probably the most important, single, parameter characterizing its fertility. For theoretical and practical reasons the soil pH is usually measured in salt solutions of different strength. The most common solution used in Europe is 1M potassium chloride (KCl) in a soil\\/solution ratio of 1:2.5 (W\\/V). The ultimate goal of the international project Copernicus of the European Community

Mariusz Fotyma; Tamara Jadczyszyn; Grzegorz Jozefaciuk

1998-01-01

174

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

175

Proximate and ultimate causes of signal diversity in the electric fish Gymnotus.  

PubMed

A complete understanding of animal signal evolution necessitates analyses of both the proximate (e.g. anatomical and physiological) mechanisms of signal generation and reception, and the ultimate (i.e. evolutionary) mechanisms underlying adaptation and diversification. Here we summarize the results of a synthetic study of electric diversity in the species-rich neotropical electric fish genus Gymnotus. Our study integrates two research directions. The first examines the proximate causes of diversity in the electric organ discharge (EOD) - which is the carrier of both the communication and electrolocation signal of electric fishes - via descriptions of the intrinsic properties of electrocytes, electrocyte innervation, electric organ anatomy and the neural coordination of the discharge (among other parameters). The second seeks to understand the ultimate causes of signal diversity - via a continent-wide survey of species diversity, species-level phylogenetic reconstructions and field-recorded head-to-tail EOD (ht-EOD) waveforms (a common procedure for characterizing the communication component of electric fish EODs). At the proximate level, a comparative morpho-functional survey of electric organ anatomy and the electromotive force pattern of the EOD for 11 species (representing most major clades) revealed four distinct groups of species, each corresponding to a discrete area of the phylogeny of the genus and to a distinct type of ht-EOD waveform. At the ultimate level, our analyses (which emphasize the ht-EOD) allowed us to conclude that selective forces from the abiotic environment have had minimal impact on the communication component of the EOD. In contrast, selective forces of a biotic nature - imposed by electroreceptive predators, reproductive interference from heterospecific congeners, and sexual selection - may be important sources of diversifying selection on Gymnotus signals. PMID:23761477

Crampton, W G R; Rodrķguez-Cattįneo, A; Lovejoy, N R; Caputi, A A

2013-07-01

176

Process-inherent, ultimate-safety (PIUS) boiling-water reactor  

SciTech Connect

A new type of boiling-water reactor (BWR) has been conceived - the Process-Inherent, Ultimate-Safety, Boiling-Water Reactor (PIUS BWR). The proposed design described in this report extends the PIUS design philosophy from pressurized-water reactors (PWRs) to BWRs. In a PIUS BWR, safety systems are passive, with no active components. The reactor core and nonnuclear portion of the plant are similar to current BWR designs, but a special, prestressed concrete reactor vessel (PCRV) with a unique internal design replaces the conventional pressure vessel, emergency core cooling systems, containment shell, spent-fuel storage ponds, diesel generators, and most other components of the nuclear island.

Forsberg, C.W.

1985-01-01

177

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

178

Genetic polymorphism of the CAPN1 gene is associated with meat quality traits in Japanese quail.  

PubMed

1. The objective of the study was to investigate the polymorphisms in two regions of the calpain 1 (CAPN1) gene and their association with breast and thigh meat quality in Japanese quail (ultimate pH (pHu), lightness, redness, yellowness, drip loss, thawing-cooking loss, water holding capacity and shear force, SF). 2. Blood samples were collected randomly from 100 birds and DNA was extracted using a commercial kit. Genotypes were determined by PCR amplification followed by single-strand conformation polymorphism (SSCP) analysis. The effect of CAPN1 genotypes on meat quality traits were analysed using a general linear model (GLM) procedure. 3. Genotypes of the CAPN1 gene in the first region (217-bp) analysed were significantly associated with yellowness and SF. The TT genotype showed significantly higher yellowness and lower shear force (more tenderness) than CT and CC genotypes. Genotypes of the second region of the gene (intron 4, 800-bp) were significantly associated with pHu, redness and SF of the breast meat. The BB genotype showed significantly lower pHu and redness and higher SF (lower tenderness) than other genotypes. 4. Information on polymorphisms of the CAPN1 gene will eventually provide useful information for improving meat quality of Japanese quail through marker-assisted selection. PMID:23647179

Rasouli, Z; Zerehdaran, S; Azari, M A; Shargh, M S

2013-01-01

179

The n-of-1 clinical trial: the ultimate strategy for individualizing medicine?  

PubMed Central

N-of-1 or single subject clinical trials consider an individual patient as the sole unit of observation in a study investigating the efficacy or side-effect profiles of different interventions. The ultimate goal of an n-of-1 trial is to determine the optimal or best intervention for an individual patient using objective data-driven criteria. Such trials can leverage study design and statistical techniques associated with standard population-based clinical trials, including randomization, washout and crossover periods, as well as placebo controls. Despite their obvious appeal and wide use in educational settings, n-of-1 trials have been used sparingly in medical and general clinical settings. We briefly review the history, motivation and design of n-of-1 trials and emphasize the great utility of modern wireless medical monitoring devices in their execution. We ultimately argue that n-of-1 trials demand serious attention among the health research and clinical care communities given the contemporary focus on individualized medicine.

Lillie, Elizabeth O; Patay, Bradley; Diamant, Joel; Issell, Brian; Topol, Eric J; Schork, Nicholas J

2011-01-01

180

Ultimate Heat Sink Thermal Performance and Water Utilization: Measurements on Cooling and Spray Ponds  

SciTech Connect

A data acquisition research program, entitled "Ultimate Heat Sink Performance Field Experiments," has been brought to completion. The primary objective is to obtain the requisite data to characterize thermal performance and water utilization for cooling ponds and spray ponds at elevated temperature. Such data are useful for modeling purposes, but the work reported here does not contain modeling efforts within its scope. The water bodies which have been studied are indicative of nuclear reactor ultimate heat sinks, components of emergency core cooling systems. The data reflect thermal performance and water utilization for meteorological and solar influences which are representative of worst-case combinations of conditions. Constructed water retention ponds, provided with absolute seals against seepage, have been chosen as facilities for the measurement programs; the first pond was located at Raft River, Idaho, and the second at East Mesa, California. The data illustrate and describe, for both cooling ponds and spray ponds, thermal performance and water utilization as the ponds cool from an initially elevated temperature. To obtain the initial elevated temperature, it has been convenient to conduct the measurements at geothermal sites having large supplies and delivery rates of hot geothermal fluid. The data are described and discussed in the text, and presented in the form of data volumes as appendices.

Athey, G. F.; Hadlock, R. K.; Abbey, 0. B.

1982-02-01

181

Static and ultimate state analysis of CFRP double-layer grids  

NASA Astrophysics Data System (ADS)

As increased in span, the selfweight and internal force of space structures in large span are also much increased, thus span of space structures is limited. Indeed, the lower weight of composite structures compared to conventional metallic structures achieves directly the weight reduction goal. Therefore, composites provide an alternative to replace conventional materials. In this paper, double-layer grids, one of the most popular space structures, are investigated. Firstly, the mechanical behaviors of CFRP tubes were studied. The design procedure of FW CFRP tubes subjected to axial loading in CFRP double-layer grids was proposed. And then, compressive and tensile strengths of series of CFRP tubes with variety of winding angles were presented. The results indicated that 0/90 lay-ups for CFRP tubes may be the best candidate. Secondly, based on identical deformation principle, CFRP double-layer grids, in which steel tubes were replaced by CFRP tubes, were designed. Thirdly, static and ultimate state analysis of CFRP double-layer grids and the same types of steel double-layer grids was carried out using the finite element program ABAQUS. The analytic results indicated that ultimate load-carrying capacity of CFRP double-layer grids is obviously higher than that of steel double-layer grids. It is seen from load-displacement curves that CFRP double-layer grids behave more brittle.

Zhang, Liangquan; Li, Hui; Ou, Jinping

2006-04-01

182

Weapons and commercial plutonium ultimate disposition choices: Destroy ``completely`` or store forever  

SciTech Connect

All of the options under consideration for weapons and commercial plutonium disposition ultimately boil down to the choices of either ``complete`` destruction or storage ``forever.`` None of the reactor-based plutonium burning systems demonstrated over the past 50 years of reactor development consume this material completely. Ultimately considerable unburned plutonium must be stored ``forever`` from those systems. Plutonium is considered to be dangerous both as a weapons material and as a health hazard. While properly stored plutonium might never make its way back by natural phenomena into the environment as a health hazard, stored plutonium is always accessible to recovery for malevolent purposes. It must be guarded wherever in the world it is stored for as long as it continues to exist. Complete destruction of the plutonium eliminates this material as a concern of future generations. Los Alamos National Laboratory accelerator-driven technology promises to allow safe and complete destruction of this material. Furthermore it appears that in the process of destruction the neutron rich features of the weapons plutonium provides benefits to society that place a value on weapons plutonium exceeding that of highly enriched uranium. A realistic time scale for development and deployment of burial technology either with or without partial burning in reactors is expected to be comparable with or to exceed the time for development and deployment of the accelerator-driven destruction method under study at Los Alamos.

Bowman, C.D.

1994-07-01

183

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

184

Flexibility in reproductive timing in human females: integrating ultimate and proximate explanations  

PubMed Central

From an ultimate perspective, the age of onset of female reproduction should be sensitive to variation in mortality rates, and variation in the productivity of non-reproductive activities. In accordance with this prediction, most of the cross-national variation in women's age at first birth can be explained by differences in female life expectancies and incomes. The within-country variation in England shows a similar pattern: women have children younger in neighbourhoods where the expectation of healthy life is shorter and incomes are lower. I consider the proximate mechanisms likely to be involved in producing locally appropriate reproductive decisions. There is evidence suggesting that developmental induction, social learning and contextual evocation may all play a role.

Nettle, Daniel

2011-01-01

185

Methods for ultimate load analysis of concrete containments: Second phase: Interim report  

SciTech Connect

This summary report gives an overview of research on the influence of special effects on the ultimate load behavior of concrete containment structures. The special effects analyses that were performed include containment response under combined pressure and temperature, shear dislocation at a major concrete crack, wall discontinuity at the wall-basemat juncture, flawed liner, and thermal buckling. The EPRI-sponsored finite element code, ABAQUS-EPGEN, is utilized as the structural analysis tool in this research. The code was modified to incorporate a constitutive model for plain concrete and models for concrete/liner and concrete/rebar interaction. The report provides a general assessment of local effects mechanisms in concrete containment response to overpressurization.

Dameron, R.A.; Dunham, R.S.; Rashid, Y.R.

1987-03-01

186

Ultimate limit and temperature dependency of light-emitting diode efficiency  

NASA Astrophysics Data System (ADS)

We discuss the ultimate limit of performance of semiconductor light-emitting diodes (LEDs) and its dependence on temperature. It is known that in high quality semiconductor materials it is, in principle, possible to reach wall plug efficiencies exceeding unity, which allows electroluminescent cooling in addition of very high efficiency light emission. Our simulation results suggest a few fairly simple measures that may further improve the external quantum efficiency (EQE) of LEDs toward the electroluminescent cooling limit. These include reducing the current density, modifying the LED structure by making thicker active regions and barrier layers, and doping of the active material. Our calculations also indicate that, contrary to the present understanding, operating LEDs at relatively high temperatures of 400-600 K may, in fact, improve the performance.

Heikkilä, Oskari; Oksanen, Jani; Tulkki, Jukka

2009-05-01

187

Ultimate Control of the Thermal Shift of a Tilted Cavity Laser Wavelength  

NASA Astrophysics Data System (ADS)

We report the possibility to realize complete thermal stabilization of the lasing wavelength ?opt in an all-epitaxial tilted cavity semiconductor laser, wherein the lasing wavelength is governed by the maximum resonance transparency of a lossy waveguide. When the positive temperature coefficient of the refractive index dn/dT is a non-linear function of the alloy composition, which is the case in most semiconductor alloys, there exists the possibility to achieve ultimate control of the resonance transparency wavelength. The thermal shift d?opt/dT can be positive, zero, or negative. An absolute thermal stabilization of the lasing wavelength is unique as compared to any conventional type of lasers.

Lifshits, M. B.; Shchukin, V. A.; Ledentsov, N. N.; Bimberg, D.

2007-04-01

188

Realization of a locally-round beam in an ultimate storage ring using solenoids  

NASA Astrophysics Data System (ADS)

“Ultimate" storage rings (USRs), with electron emittance smaller than 100 pm-rad and on the scale of the diffraction limit for hard X-rays in both transverse planes, have the potential to deliver photons with much higher brightness and higher transverse coherence than that projected for the rings currently operational or under construction. Worldwide efforts have been made to design and to build light sources based on USRs. How to obtain a round beam, i.e., a beam with equivalent transverse emittances, is an important topic in USR studies. In this paper, we show that a locally-round beam can be achieved by using a pair of solenoid and anti-solenoid with a circularly polarized undulator located in between. Theoretical analysis and application of this novel method, particularly to one of the Beijing Advanced Photon Source storage ring design having natural emittance of 75 pm·rad, are presented.

Xu, Gang; Jiao, Yi; Tian, Sai-Ke

2013-06-01

189

Comparison of ultimate limits of interband cascade infrared photodetectors and single-absorber detectors  

NASA Astrophysics Data System (ADS)

A comparison of the ultimate limits of multiple-stage interband cascade infrared photodetectors (ICIPs) with standard single-absorber photovoltaic infrared detectors is presented. In particular, we focus on how the multiple-stage architecture can offer an improvement in sensitivity over single-absorber detectors in situations where the latter detector type is limited by a low photocarrier collection efficiency. A general overview of the ICIP architecture and its benefits in carrier collection improvement, and noise reduction is presented. The developed theory is then applied to compare single- and multiple-stage detectors operating in the strong signal regime. It is found that if ICIPs are designed with photocurrent-matched absorbers, the signal-to-noise ratio depends on the total particle conversion efficiency of the device. The potential benefits of the ICIP architecture are shown to be greatest when the quantum efficiency of singleabsorber detectors is limited by poor photo-carrier extraction.

Hinkey, Robert T.; Yang, Rui Q.

2013-09-01

190

Proximate and Ultimate Analyses of Bagasse, Sorghum and Millet Straws as Precursors for Active Carbons  

NASA Astrophysics Data System (ADS)

This study reports the proximate and ultimate characteristics of bagasse, sorghum and millet straws in relation to their suitability for producing highly porous carbon. The results of ad hoc samples indicated, that particle size has a decisive influence on the proximate characteristics of bagasse, sorghum and millet straws. The effects of particle size on weight loss characteristics; rates of dehydration and de-volatilization of the carbon precursors were used to assess particle sizes that may be appropriate for carbonization. Particle sizes of 425-1180 Āµm are thus, suggested to be the most desirable, for the production of good quality porous carbon. This range of particles of bagasse, sorghum and millet straws were associated with diminishing ash contents. However, the optimum particle size of the cellulosic materials that is expected to yield highly porous carbon with minimum ash contents is 1180 Āµm.

Lori, J. A.; Lawal, A. O.; Ekanem, E. J.

191

On a consistent field transfer in non linear inelastic analysis and ultimate load computation  

NASA Astrophysics Data System (ADS)

In this work we propose a field transfer operator for remeshing carried out in the course of incremental analysis of a non linear inelastic behavior. The proposed procedure is geared towards the ultimate load computation of a complex structure, where we choose the appropriate mesh grading for each different phase of computations, starting with a coarse mesh for the initial linear response and going towards a more refined mesh for highly nonlinear inelastic response. The proposed projection operator is developed on the basis of diffuse approximation method. The key feature of such an operator is to guarantee the conservation of relevant mechanics quantities which ensures a superior performance of the proposed field transfer with respect to the standard remeshing procedure. We present the illustrative results both for an isotropic damage model and standard plasticity model, indicating very satisfying performance.

Brancherie, Delphine; Villon, Pierre; Ibrahimbegovic, Adnan

2008-07-01

192

Welcomed within Graceland, Elvis impersonators gather for finals of the first "Ultimate Elvis" contest  

NSDL National Science Digital Library

The King serves motorists at Roseburg Albertson's, will entertain for employeeshttp://www.newsreview.info/article/20070814/NEWS/70814022Ultimate Elvis Contest [pdf]http://www.elvis.com/ultimatecontest/How Did Elvis Get Turned Into a Racist?http://www.elvis.com.au/presley/peter_guralnick__elvis_racist.shtmlJoe Moscheo's The Gospel of Elvis Presleyhttp://www.cmt.com/news/articles/1566978/20070813/presley_elvis.jhtmlElvis: 30 weird and wonderful factshttp://www.belfasttelegraph.co.uk/entertainment/music-gigs/news/article2859595.eceAmazing Grace [Real Player]http://lcweb2.loc.gov/diglib/ihas/loc.natlib.ihas.200149090/default.htmlIf imitation is in fact the sincerest form of flattery, then the late Elvis Presley must certainly be flattered someplace in the great beyond. Even before he passed away thirty years ago, there were Elvis impersonators (some prefer the term "tribute artist") who traveled the globe performing as the King of Rock and Roll in a variety of guises. The permutations are seemingly endless, and they include those who adopt Elvis's signature late 1960s massive sideburns and still others whose sartorial style is not complete with a jumpsuit overloaded with sequins and other trappings. The folks who have managed Elvis's estate and Graceland have generally been dismissive of these tribute artists. However, this indifference has recently changed into a rather warm welcome as the company that operates Graceland will pay host to the first annual finals of the "Ultimate Elvis" contest this Friday. The contest has been going on since March, and one grand prize winner will be selected in what promises to be quite a competition. While some Elvis devotees may still look askance at such events, Paul Jankowski, the marketing chief of Elvis Presley Enterprises, Inc. was emphatic as he spoke about this event: "This is not an impersonator contest. This is all about paying tribute to Elvis." The first link will take visitors to a piece from this Tuesday's Washington Post which talks about the "Ultimate Elvis" contest at Graceland. Several thousand miles away in Roseburg, Oregon, The News-Review recently reported on Jerry Norby, a newly minted Elvis, and his first day on the job. Visitors can read about Norby and his work pumping gas and singing "My Way" at the second link. The third link leads to the homepage of the Ultimate Elvis Contest. Here, visitors can learn about the finalists and read a letter from Elvis to a tribute artist. The fourth link leads to a recent editorial by Elvis biographer Peter Guralnick which first appeared in the New York Times. In the piece, Guralnick addresses the "absurd claims" that contend Elvis was a racist. For another perspective on Elvis's life, visitors will want to check out the fifth link, which contains an excerpt from Joe Moscheo's recent book which recalls his time performing with Elvis and his well-documented love of gospel music. The sixth link leads to a listing of thirty little-known facts about Elvis, including the observation that his Grammy Awards all came from his numerous gospel recordings. The final link leads to one such recording, which happens to be his 1971 recording of "Amazing Grace".

Grinnell, Max

2007-08-17

193

Xenobiology: A new form of life as the ultimate biosafety tool  

PubMed Central

Synthetic biologists try to engineer useful biological systems that do not exist in nature. One of their goals is to design an orthogonal chromosome different from DNA and RNA, termed XNA for xeno nucleic acids. XNA exhibits a variety of structural chemical changes relative to its natural counterparts. These changes make this novel information-storing biopolymer “invisible” to natural biological systems. The lack of cognition to the natural world, however, is seen as an opportunity to implement a genetic firewall that impedes exchange of genetic information with the natural world, which means it could be the ultimate biosafety tool. Here I discuss, why it is necessary to go ahead designing xenobiological systems like XNA and its XNA binding proteins; what the biosafety specifications should look like for this genetic enclave; which steps should be carried out to boot up the first XNA life form; and what it means for the society at large.

Schmidt, Markus

2010-01-01

194

The ultimate flexural strength of the lumbar spine and vertebral bone mineral content.  

PubMed

Flexion-distraction injuries (lap seat-belt injuries resulting from car accidents) were simulated by exposing 16 lumbar functional spinal units (FSUs) to a combined quasistatic load of bending and shearing in the sagittal plane. The load response of the FSU was measured by means of a force and moment transducer. Displacements and angulations were measured and calculated by means of dial gauges and photographs taken after each loading step. The mean angulation between the vertebrae just before total rupture was 20 degrees. The ultimate values of bending moment, shear force, and bending stiffness were correlated with the bone mineral content (BMC), and so were the horizontal and vertical displacements determined around the yield point on the load-displacement curve. PMID:8219545

Neumann, P; Osvalder, A L; Nordwall, A; Lövsund, P; Hansson, T

1993-08-01

195

Xenobiology: a new form of life as the ultimate biosafety tool.  

PubMed

Synthetic biologists try to engineer useful biological systems that do not exist in nature. One of their goals is to design an orthogonal chromosome different from DNA and RNA, termed XNA for xeno nucleic acids. XNA exhibits a variety of structural chemical changes relative to its natural counterparts. These changes make this novel information-storing biopolymer "invisible" to natural biological systems. The lack of cognition to the natural world, however, is seen as an opportunity to implement a genetic firewall that impedes exchange of genetic information with the natural world, which means it could be the ultimate biosafety tool. Here I discuss, why it is necessary to go ahead designing xenobiological systems like XNA and its XNA binding proteins; what the biosafety specifications should look like for this genetic enclave; which steps should be carried out to boot up the first XNA life form; and what it means for the society at large. PMID:20217844

Schmidt, Markus

2010-04-01

196

The ``Ultimate'' CMOS Device: A 2003 Perspective (Implications For Front-End Characterization And Metrology)  

NASA Astrophysics Data System (ADS)

The evolution of planar, conventional CMOS to non-classical CMOS devices as described in the International Technology Roadmap for Semiconductors (ITRS) is discussed. The benefits of strained silicon configurations to enhance the channel mobility, silicon-on-insulator (SOI) to enhance the reduction of residual parasitics and non-planar transistor device structures to improve control of the short-channel effects are discussed. The combination of the above enhancements, in conjunction with the current state-of-the art global efforts in high-k gate dielectrics, metal electrodes and elevated source/drain, offers a plethora of opportunities requiring careful assessment of the optimal solution for each organization's portfolio of products and projected market position. Several of these possible solutions for the ``ultimate'' CMOS device are discussed from today's perspective, with attention to the characterization and metrology for assessing these alternate device structures.

Huff, Howard R.; Zeitzoff, Peter M.

2003-09-01

197

Towards the ultimate storage ring: The lattice design for Beijing Advanced Photon Source  

NASA Astrophysics Data System (ADS)

A storage ring-based light source, Beijing Advanced Photon Source (BAPS), is proposed to store a 5 GeV low-emittance electron beam and to provide high-brilliance coherent radiation. In this paper, we report our efforts of pushing down the emittance of BAPS to approach the so-called ultimate storage ring, while fixing the circumference to about 1200 m. To help deal with the challenge of beam dynamics associated with the intrinsic, very strong nonlinearities in an ultralow-emittance ring, a combination of several progressive technologies is used in the linear optics design and nonlinear optimization, such as a modified theoretical minimum emittance cell with small-aperture magnets, quasi-3rd-order achromat, theoretical analyzer based on Lie Algebra and Hamiltonian analysis, multi-objective genetic algorithm and frequency map analysis. These technologies enable us to obtain satisfactory beam dynamics in one lattice design with natural emittance of 75 pm.

Xu, Gang; Jiao, Yi

2013-05-01

198

Ultimate fine-pitch resist patterning using the ASET-HINA  

NASA Astrophysics Data System (ADS)

This study had two goals. One was the evaluation of the ultimate fine-pitch patterning performance of the high-numerical-aperture (NA = 0.3) small-field EUV exposure tool (HINA). The other was the evaluation of the lithographic performance of conventional chemically-amplified (CA) polymeric resists and molecular resists using the HINA. Imaging experiments were carried out using coherent illumination (? = 0.0). An EUV mask with a 60~80-nm-thick TaGeN absorber and a 10-nm-thick Cr buffer layer was fabricated to replicate dense sub-30-nm patterns. To determine the ultimate resolution of the HINA under three-ray interference in the sagittal direction, sub-30-nm-wide lines and spaces were delineated in a non-chemically-amplified resist. The smallest patterns delineated were dense 27-nm-wide lines, and the resolution obtained was nearly equal to the resolution limit of the HINA, which is the cut-off frequency of the optics in three-ray interference. A polymeric CA resist based on acetal-protected poly(hydroxystyrene) provided the best performance. It enabled the delineation of 28-nm-wide lines and spaces in a 70-nm-thick layer of resist at an exposure dose of 10 mJ/cm2. A CA positive-tone resist based on low-molecular-weight amorphous polyphenol was also tested. It consists of a partially protected polyphenol, namely, 4,4'-methylenebis[2-[di(2,5-dimehtyl-4-hydroxyphenyl) methyl]phenol (25X-MBSA-P). It enabled the delineation of 30-nm-wide lines and spaces in a 40-nm-thick layer at an exposure dose of 10 mJ/cm2. In addition, the sub-22-nm patterning of CA resists was performed under two-ray interference in the meridional direction.

Oizumi, H.; Tanaka, Y.; Kumasaka, F.; Nishiyama, I.

2006-04-01

199

Addition of zinc methacrylate in dental polymers: MMP-2 inhibition and ultimate tensile strength evaluation.  

PubMed

This study evaluated the effect of zinc methacrylate (ZM) on the inhibition of matrix metalloproteinase 2 (MMP-2) and the ultimate tensile strength (UTS) of an experimental polymer. Enzymes secreted from mouse gingival tissues were analyzed by gelatin zymography in buffers containing 5 mM CaCl(2) (Tris-CaCl(2)) in 50 mM Tris-HCl buffer with various concentrations of ZM (0.5, 1, 2, 4, 8, and 16 mM). The matrix metalloproteinases present in the conditioned media were characterized by immunoprecipitation. The polymer UTS evaluation was performed in eight groups with various concentrations of ZM (0, 0.5, 1, 2.5, 5, 10, 20, and 30 wt.%), in a mechanical testing machine. MMP-2 (62 kDa) was detected in the zymographic assays and inhibited by ZM in all tested concentrations. UTS data were submitted to one-way ANOVA and Tukey's test (??=?0.05), and no significant differences were observed among groups, except in the polymer containing 30% ZM, presenting a significantly lower value when compared with the control group (p?ultimate tensile strength of the polymer. Zinc methacrylate is a metalloproteinase inhibitor that can be copolymerized with other methacrylate monomers. Yet, the addition of ZM did not affect the resin bond strength. Thus, in vivo tests should be performed to evaluate the performance of this material. PMID:21448634

Henn, Sandrina; de Carvalho, Rodrigo Varella; Ogliari, Fabrķcio Aulo; de Souza, Ana Paula; Line, Sergio Roberto Peres; da Silva, Adriana Fernandes; Demarco, Flįvio Fernando; Etges, Adriana; Piva, Evandro

2011-03-30

200

Stapledon's Interplanetary Man: A Commonwealth of Worlds and the Ultimate Purpose of Space Colonisation  

NASA Astrophysics Data System (ADS)

In his 1948 lecture to the British Interplanetary Society Stapledon considered the ultimate purpose of colonising other worlds. Having examined the possible motivations arising from improved scientific knowledge and access to extraterrestrial raw materials, he concludes that the ultimate benefits of space colonisation will be the increased opportunities for developing human (and post-human) diversity, intellectual and aesthetic potential and, especially, `spirituality'. By the latter concept he meant a striving for ``sensitive and intelligent awareness of things in the universe (including persons), and of the universe as a whole.'' A key insight articulated by Stapledon in this lecture was that this should be the aspiration of all human development anyway, with or without space colonisation, but that the latter would greatly increase the scope for such developments. Another key aspect of his vision was the development of a diverse, but connected, `Commonwealth of Worlds' extending throughout the Solar System, and eventually beyond, within which human potential would be maximised. In this paper I analyse Stapledon's vision of space colonisation, and will conclude that his overall conclusions remain sound. However, I will also argue that he was overly utopian in believing that human social and political unity are prerequisites for space exploration (while agreeing that they are desirable objectives in their own right), and that he unnecessarily downplayed the more prosaic scientific and economic motivations which are likely to be key drivers for space exploration (if not colonisation) in the shorter term. Finally, I draw attention to some recent developments in international space policy which, although probably not influenced by Stapledon's work, are nevertheless congruent with his overarching philosophy as outlined in `Interplanetary Man?'.

Crawford, Ian A.

201

Water quality variation and clam growth: Is pH really a non-issue in estuaries?  

Microsoft Academic Search

A tandem deployment system was used to critically evaluate relationships between important water chemistry parameters (pH,\\u000a salinity, dissolved oxygen) and biotic performance based on clam growth. The effects of environmental conditions on growth\\u000a of juvenile clams,Mercenaria mercenaria, were determined after 7-day field deployments in cages at reference sites from 1998 to 2000. Continuous measurements of\\u000a the overlying water chemistry parameters

Amy H. Ringwood; Charles J. Keppler

2002-01-01

202

Lattice Design for PEP-X Ultimate Storage Ring Light Source  

SciTech Connect

SLAC expertise in designing and operating high current storage rings and the availability of the 2.2-km PEP-II tunnel present an opportunity for building a next generation light source - PEP-X - that would replace the SPEAR3 storage ring in the future. The PEP-X 'baseline' design, with 164 pm-rad emittance at 4.5 GeV beam energy and a current of 1.5 A, was completed in 2010. As a next step, a so-called 'ultimate' PEP-X lattice, reducing the emittance to 11 pm-rad at zero current, has been designed. This emittance approaches the diffraction limited photon emittance for multi-keV photons, providing near maximum photon brightness and high coherence. It is achieved by using 7-bend achromat cells in the ring arcs and a 90-m damping wiggler in one of the 6 long straight sections. Details of the lattice design, dynamic aperture, and calculations of the intra-beam scattering effect and Touschek lifetime at a nominal 0.2 A current are presented. Accelerator-based light sources are in high demand for many experimental applications. The availability of the 2.2-km PEP-II tunnel at SLAC presents an opportunity for building a next generation light source - PEP-X - that would replace the existing SPEAR3 light source in the future. The PEP-X study started in 2008, and the 'baseline' design, yielding 164 pm-rad emittance at 4.5 GeV beam energy and a current of 1.5 A, was completed in 2010. This relatively conservative design can be built using existing technology. However, for a long term future, it is natural to investigate a more aggressive, so-called 'ultimate' ring design. The goal is to reduce the electron emittance in both x and y planes to near the diffraction limited photon emittance of 8 pm-rad at hard X-ray photon wavelength of 0.1 nm. This would provide a near maximum photon brightness and significant increase in photon coherence. This study was motivated by the advances in low emittance design at MAX-IV. The latter was used as a starting point for the PEP-X arc lattice, however new features were included into the design for better tuning capabilities and compensation of non-linear optics effects. Further emittance reduction is achieved with a 90-m damping wiggler. Finally, intra-beam scattering (IBS) and Touschek lifetime effects were estimated and cross-checked using various codes.

Bane, K.L.F.; Cai, Y.; Nosochkov, Y.; Wang, M.-H.; /SLAC; Hettel, R.O.; /SLAC

2011-12-13

203

Stiffness and ultimate load of osseointegrated prosthesis fixations in the upper and lower extremity  

PubMed Central

Background Techniques for the skeletal attachment of amputation-prostheses have been developed over recent decades. This type of attachment has only been performed on a small number of patients. It poses various potential advantages compared to conventional treatment with a socket, but is also associated with an increased risk of bone or implant-bone interface fracture in the case of a fall. We therefore investigated the bending stiffness and ultimate bending moment of such devices implanted in human and synthetic bones. Methods Eight human specimens and 16 synthetic models of the proximal femora were implanted with lower extremity prostheses and eight human specimens and six synthetic humeri were implanted with upper extremity prostheses. They were dissected according to typical amputation levels and underwent loading in a material testing machine in a four-point bending setup. Bending stiffness, ultimate bending moment and fracture modes were determined in a load to failure experiment. Additionally, axial pull-out was performed on eight synthetic specimens of the lower extremity. Results Maximum bending moment of the synthetic femora was 160.6±27.5 Nm, the flexural rigidity of the synthetic femora was 189.0±22.6 Nm2. Maximum bending moment of the human femora was 100.4±38.5 Nm, and the flexural rigidity was 137.8±29.4 Nm2. The maximum bending moment of the six synthetic humeri was 104.9±19.0 Nm, and the flexural rigidity was 63.7±3.6 Nm2. For the human humeri the maximum bending moment was 36.7±11.0 Nm, and the flexural rigidity at was 43.7±10.5 Nm2. The maximum pull-out force for the eight synthetic femora was 3571±919 N. Conclusion Significant differences were found between human and synthetic specimens of the lower and upper extremity regarding maximum bending moment, bending displacement and flexural rigidity. The results of this study are relevant with respect to previous finding regarding the load at the interfaces of osseointegrated prosthesis fixation devices and are crucial for the development of safety devices intended to protect the bone-implant interface from damaging loadings.

2013-01-01

204

The initial freezing point temperature of beef rises with the rise in pH: a short communication.  

PubMed

This study tested the hypothesis that the initial freezing point temperature of meat is affected by pH. Sixty four bovine M. longissimus thoracis et lumborum were classified into two ultimate pH groups: low (<5.8) and high pH (>6.2) and their cooling and freezing point temperatures were determined. The initial freezing temperatures for beef ranged from -0.9 to -1.5°C (?=0.6°C) with the higher and lower temperatures associated with high and low ultimate pH respectively. There was a significant correlation (r=+0.73, P<0.01) between beef pH and freezing point temperature in the present study. The outcome of this study has implications for the meat industry where evidence of freezing (ice formation) in a shipment as a result of high pH meat could result in a container load of valuable chilled product being downgraded to a lower value frozen product. PMID:23410892

Farouk, M M; Kemp, R M; Cartwright, S; North, M

2013-01-11

205

Reproductive skew in female common marmosets: what can proximate mechanisms tell us about ultimate causes?  

PubMed Central

Common marmosets are cooperatively breeding monkeys that exhibit high reproductive skew: most subordinate females fail to reproduce, while others attempt to breed but produce very few surviving infants. An extensive dataset on the mechanisms limiting reproduction in laboratory-housed and free-living subordinate females provides unique insights into the causes of reproductive skew. Non-breeding adult females undergo suppression of ovulation and inhibition of sexual behaviour; however, they receive little or no aggression or mating interference by dominants and do not exhibit behavioural or physiological signs of stress. Breeding subordinate females receive comparable amounts of aggression to non-breeding females but are able to conceive, gestate and lactate normally. In groups containing two breeding females, however, both dominant and subordinate breeders kill one another's infants. These findings suggest that preconception reproductive suppression is not imposed on subordinate females by dominants, at a proximate level, but is instead self-imposed by most subordinates, consistent with restraint models of reproductive skew. In contrast to restraint models, however, this self-suppression probably evolved not in response to the threat of eviction by dominant females but in response to the threat of infanticide. Thus, reproductive skew in this species appears to be generated predominantly by subordinate self-restraint, in a proximate sense, but ultimately by dominant control over subordinates' reproductive attempts.

Saltzman, Wendy; Digby, Leslie J.; Abbott, David H.

2008-01-01

206

A novel pathway to the ultimate mutagens of aromatic amino and nitro compounds  

SciTech Connect

Photolysis of arylazides in aqueous media was recently found to generate presumed nitrenium ions, species which are generally considered as the ultimate mutagens/carcinogens derived from arylamines and nitroarenes. the primary photolysis products of arylazides, the arylnitrenes, can possibly react as electrophiles themselves, or they can be protonated and thus form the electrophilic nitrenium ions. Numerous arylazides and aryldiazides can be photoactivated to short-lived mutagens detectable in Salmonella typhimurium TA98. Structure-activity comparisons between arylazides and the matching arylamines and nitroarenes show correlations; e.g., phenyl azide and methyl-substituted phenyl azides are not mutagenic or only weakly mutagenic like aniline, nitrogenzene, and their methyl homologues, whereas 4-azidodiphenyl, 2-azidofluorene, 1-azidopyrene, azido-IQ, and azido-isoIQ are increasingly mutagenic in that order, like the matching amino and nitrogen compounds. It is hypothesized on the basis of these data that the nitrene/nitrenium ion is the reactive intermediate common to the three mutagenic pathways and that the reaction of the nitrene/nitrenium ion with DNA is rate limiting for the overall mutagenic process in Salmonella. The photochemical generation from arylazides of the reactive species, the nitrene/nitrenium ions, opens new perspectives for the understanding of the genotoxic activity of arylamines and nitroarenes in general and, specifically, of the food mutagens/carcinogens of the IQ type.

Wild, D. (Univ. of Wuerzburg (West Germany))

1990-08-01

207

Design Dependent Cutoff Frequency of Nanotransistors Near the Ultimate Performance Limit  

NASA Astrophysics Data System (ADS)

We have studied the effect of different structural designs of double gate MOSFETs (DG-MOSFETs) and carbon nanotube field effect transistors (CNTFETs) on the cutoff frequency (fT). The effects of metallic contacts with Schottky barriers, gate work function, dual material gate (DMG), halo doped channel and lightly doped drain and source (LDDS) architectures on the fT have been investigated for DG-MOSFETs and CNTFETs and the design dependent fT for both types of transistors has been studied for the first time. The simulations are based on the Schrödinger-Poisson solvers developed for each nanotransistor separately. The ballistic limit has been studied as the ultimate performance limit of the DG-MOSFETs and CNTFETs. The results of this paper, for the first time, show how some designations used for modification of short channel effects or current-voltage characteristics affect the fT. The results revealed that the cutoff frequencies of both types of the transistors exhibit the same behavior with changing design parameters. We have shown that the Schottky barriers, parasitic capacitances and halo doping reduce the fT and have proposed the DMG and LDDS artchitectures as ways to increase the fT for DG-MOSFETs and CNTFETs for the first time.

Kordrostami, Zoheir; Sheikhi, M. Hossein; Zarifkar, Abbas

2012-12-01

208

Effects of solvent drying time and water storage on ultimate tensile strength of adhesives.  

PubMed

AIM: Simplified adhesives are a blend of monomers with solvents that are expected to evaporate before light curing. The aim of the present study was to evaluate the effects of drying time and water storage on the ultimate tensile strength (UTS) of three adhesives: Adper Single Bond 2 (ASB), One-Step Plus (OSP) and Clearfil S(3) Bond (CSB). METHODS: Dumbbell-shaped samples from each adhesive were prepared in three groups: (a) air drying prior to light curing; (b) no drying equal to active air drying; and (c) 3-h drying. Each group was further divided into two subgroups of no storage or 7 days' water storage, prior to the UTS measurement (n = 10). RESULTS: Material, drying-time, and storage had a significant effect on UTS, and the interactions of the factors were also significant (P < 0.05). OSP showed a higher evaporation rate under passive air drying, and OSP and CSB showed higher UTS values compared to ASB (P < 0.05). Air drying improved UTS in OSP and CSB, but not in ASB. Likewise, water storage only affected the UTS of OSP and CSB. CONCLUSIONS: The effects of air drying and water storage period on UTS are material dependent. Whenever solvent evaporation improved the UTS of adhesive, water storage decreased it. The all-in-one self-etching adhesive can maximize its best properties when the solvent is dried for an extended period. PMID:23355434

Emamieh, Shila; Sadr, Alireza; Ghasemi, Amir; Torabzadeh, Hassan; Akhavanzanjani, Vegharedin; Tagami, Junji

2013-01-25

209

[Temporary total fecal diversion--ultimate solution for complex recurrent anal fistula].  

PubMed

Anal fistula is a frequent disease, but complex fistulae are relatively uncommon. The treatment for this pathology remains debated all over the world, and in cases of complex fistulae represents a challenge. We present a 55 years old male, operated more than 40 times in the last 15 years for perianal recurrent fistulas and abscesses. The fistula has had a progressive evolution despite all kind of surgery and has extended finally to entire perineal and gluteal region; more than 30 orifices were founded on skin surface and many internal anorectal orifices as well. The patient is weakened, anemic, in chronic sepsis. As a last resort, we decided to perform a terminal fecal diverting stoma at the level of sigmoid colon, with closure of distal end. There were subsequent operations necessary to resolve perineal and gluteal disease: extensive excisions of altered tissues, various full-thickness skin grafts and covering flaps. After 12 months the perineal region was clean, so remaking of colic continuity was possible. Continuous follow-up until 12 months revealed no sign of recurrence. We conclude that temporary total fecal diversion followed by wide excisions of perianal fistulous tissues represents an ultimate solution to complex recurrent perianal fistula, with good results at least in our case. PMID:20187479

Oni?a, M; Dumnici, A; Hornung, E; Papiu, H; Tar?a, C; Aiordachioaei, G; Goldi?s, D; Oni?a, C

210

Ultimate enhancement of the local density of electromagnetic states outside an absorbing sphere  

NASA Astrophysics Data System (ADS)

The local density of states (LDOS) of the electromagnetic field on the surface of an absorbing dielectric microsphere at frequencies of the whispering-gallery modes (WGMs) is evaluated using the dyadic Green tensors of the electric and magnetic fields. In the calculation, the morphology-dependent resonances in the frequency dependence of the Mie coefficients are described analytically in terms of the resonant frequency and the partial quality factors which allow for light radiation and absorption. The Purcell factor of LDOS enhancement by WGMs is calculated to be proportional to the product of the quality factor and the squared ratio of the light wavelength to the sphere diameter. The ultimate values of the electric-field LDOS enhancement are estimated to be of the order of 107 for a fused-silica microsphere in air. The efficiency of radiation of the resonant spontaneous emission from electric dipoles located near the surface outside of a sphere is determined. The characteristics of a dielectric microsphere are compared with those of other cavities.

Datsyuk, Vitaly V.

2007-04-01

211

Heat transport near the transition to the ultimate state of turbulent Rayleigh-B'enard convection  

NASA Astrophysics Data System (ADS)

Measurements of the Nusselt number Nu for Rayleigh-B'enard convection (RBC) of a cylindrical sample over the Rayleigh-number range 2x10^12 <=Ra <=2x10^15 and the Prandtl-number range 0.79 <=Pr <=0.86 are presented. The aspect ratio ??D/L was 0.50 (D= 1.12 m was the diameter and L = 2.24 m was the height). For Ra <=2x10^13 the data yielded Nu = Nu0Ra^?eff with ?eff= 0.312, consistent with classical RBC.ootnotetextG. Ahlers, S. Grossmann, and D. Lohse, Rev. Mod. Phys. 81, 503 (2009) For larger Ra ?eff increased, reaching approximately ?eff= 0.38 near Ra = 10^15, consistent with predictionsootnotetextR. H. Kraichnan, Phys. Fluids 5, 1374 (1962)^,ootnotetextS. Grossmann and D. Lohse, Phys. Fluids 23, 045108 (2011) for an ultimate state with turbulent boundary layers.

Ahlers, Guenter; He, Xiaozhou; Funfschilling, Denis; Nobach, Holger; Bodenschatz, Eberhard

2011-11-01

212

PEP-X: An Ultimate Storage Ring Based on Fourth-Order Geometric Achromats  

SciTech Connect

We have designed an 'ultimate' storage ring for the PEP-X light source that achieves the diffraction limited emittances (at 1.5 {angstrom}) of 12 pm-rad in both horizontal and vertical planes with a 4.5-GeV beam. These emittances include the contribution of intrabeam scattering at a nominal current of 200 mA in 3300 bunches. This quality beam in conjunction with a conventional 4-m undulator in a straight section can generate synchrotron radiation having a spectral brightness above 10{sup 22} [photons/s/mm{sup 2}/mrad{sup 2}/0.1% BW] at a 10 keV photon energy. The high coherence at the diffraction limit makes PEP-X competitive with 4th generation light sources based on an energy recovery linac. In addition, the beam lifetime is several hours and the dynamic aperture is large enough to allow off-axis injection. The alignment and stability tolerances, though challenging, are achievable. A ring with all these properties is only possible because of several major advances in mitigating the effects of nonlinear resonances.

Cai, Yunhai; Bane, Karl; Hettel, Robert; Nosochkov, Yuri; Wang, Min-Huey; /SLAC

2012-04-06

213

The ultimate technology: the end of technology and the task of nature.  

PubMed

Abstract One of the most influential philosophers of the 20th century, Martin Heidegger (1889-1976), died prior to the remarkable cloning of the sheep Dolly and before Dr. Venter started his experiments on creating synthetic life, and he never explicitly discussed living technologies. However, by reinterpreting his notion of "modern technology," this article shows how it is possible to philosophically assess living technologies and to recognize ways in which Heidegger anticipated this phenomenon with his notion of cybernetics. The interpretation elucidates the fundamental process of technology becoming living and simultaneously presents living technology as the ultimate technology. The thesis of this article is that living technology is not just one more technology; rather, it is the perfection of technology as understood by Aristotle. Aristotle's thinking is in this way a key example of a profound reassessment of nature and technology. Aristotle clearly separates these two domains of being in his definition, but in doing so, he also connects them to one another in a highly influential way. Following this line of thought, the article finally offers an original perspective involving renewed respect for the perpetual self-unfolding nature of living technology. PMID:23889743

Riis, Sųren

2013-07-26

214

Dynamic Aperture and Tolerances for PEP-X Ultimate Storage Ring Design  

SciTech Connect

A lattice for the PEP-X ultimate storage ring light source, having 11 pm-rad natural emittance at a beam energy of 4.5 GeV at zero current, using 90 m of damping wiggler and fitting into the existing 2.2-km PEP-II tunnel, has been recently designed. Such a low emittance lattice requires very strong sextupoles for chromaticity correction, which in turn introduce strong non-linear field effects that limit the beam dynamic aperture. In order to maximize the dynamic aperture we choose the cell phases to cancel the third and fourth order geometric resonances in each 8-cell arc. Four families of chromatic sextupoles and six families of geometric (or harmonic) sextupoles are added to correct the chromatic and amplitude-dependent tunes. To find the best settings of the ten sextupole families, we use a Multi-Objective Genetic Optimizer employing elegant to optimize the beam lifetime and dynamic aperture simultaneously. Then we evaluate dynamic aperture reduction caused by magnetic field multipole errors, magnet fabrication errors and misalignments. A sufficient dynamic aperture is obtained for injection, as well as workable beam lifetime.

Borland, M.; /Argonne; Cai, Y.; Nosochkov, Y.; Wang, M.-H.; /SLAC; Hettel, R.O.; /SLAC

2011-12-13

215

Emotional contagion in soccer penalty shootouts: celebration of individual success is associated with ultimate team success.  

PubMed

We examined the association between celebratory responses after successful soccer penalty kicks and the outcome of a penalty shootout. Individually displayed post-shot behaviours in penalty shootouts held in World Cups and European Championships (N = 151) were rated on the presence of universally distinct and recognizable behaviours associated with positive emotions. Using chi-square analyses we investigated which behaviours were associated with winning the shootout, when the relative standing between the teams was equal. Players who engaged in certain celebratory post-shot behaviours were more likely to be in the team that ultimately won the penalty shootout. In particular, celebrations including both arms were associated with winning the shootout. It was more likely that the next kick taken by an opponent was missed after a player displayed these behaviours after a goal than when he did not. The findings are interpreted in terms of emotional contagion - that is, the transference of emotions from individuals onto teammates and opponents. It is suggested that the individual expression of post-performance emotions serves a direct purpose in enhancing future team performance and that emotional contagion is an important process in the context of elite sport performance. PMID:20544488

Moll, Tjerk; Jordet, Geir; Pepping, Gert-Jan

2010-07-01

216

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

217

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

218

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

219

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

220

17 CFR 240.15c3-1g - Conditions for ultimate holding companies of certain brokers or dealers (Appendix G to 17 CFR 240...  

Code of Federal Regulations, 2010 CFR

...repurchase agreements, stock lending and borrowing...ultimate holding company's maximum potential...repurchase agreements, stock lending and borrowing...ultimate holding company may request Commission...ultimate holding company's exposures on...basis for each of the top ten countries...

2010-04-01

221

17 CFR 240.15c3-1g - Conditions for ultimate holding companies of certain brokers or dealers (Appendix G to 17 CFR 240...  

Code of Federal Regulations, 2010 CFR

...repurchase agreements, stock lending and borrowing...ultimate holding company's maximum potential...repurchase agreements, stock lending and borrowing...ultimate holding company may request Commission...ultimate holding company's exposures on...basis for each of the top ten countries...

2009-04-01

222

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

223

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

224

Towards ultimate optical lithography with NXT:1950i dual stage immersion platform  

NASA Astrophysics Data System (ADS)

Optical lithography, currently being used for 45-nm semiconductor devices, is expected to be extended further towards the 32-nm and 22-nm node. A further increase of lens NA will not be possible but fortunately the shrink can be enabled with new resolution enhancement methods like source mask optimization (SMO) and double patterning techniques (DPT). These new applications lower the k1 dramatically and require very tight overlay control and CD control to be successful. In addition, overall cost per wafer needs to be lowered to make the production of semiconductor devices acceptable. For this ultimate era of optical lithography we have developed the next generation dual stage NXT:1950i immersion platform. This system delivers wafer throughput of 175 wafers per hour together with an overlay of 2.5nm. Several extensions are offered enabling 200 wafers per hour and improved imaging and on product overlay. The high productivity is achieved using a dual wafer stage with planar motor that enables a high acceleration and high scan speed. With the dual stage concept wafer metrology is performed in parallel with the wafer exposure. The free moving planar stage has reduced overhead during chuck exchange which also improves litho tool productivity. In general, overlay contributors are coming from the lithography system, the mask and the processing. Main contributors for the scanner system are thermal wafer and stage control, lens aberration control, stage positioning and alignment. The back-bone of the NXT:1950i enhanced overlay performance is the novel short beam fixed length encoder grid-plate positioning system. By eliminating the variable length interferometer system used in the previous generation scanners the sensitivity to thermal and flow disturbances are largely reduced. The alignment accuracy and the alignment sensitivity for process layers are improved with the SMASH alignment sensor. A high number of alignment marker pairs can be used without throughput loss, and furthermore the GridMapper functionality which is using the inter-die and intra-die scanner capability can reduce overlay errors coming from mask and process without productivity impact. In this paper we will present the main design features and discuss the system performance of the NXT:1950i system, focusing on the improvements made in overlay and productivity. We will show data on imaging, overlay, focus and productivity supporting the 3X-nm node and we will discuss next improvement steps towards the 2X-nm node.

Castenmiller, Tom; van de Mast, Frank; de Kort, Toine; van de Vin, Coen; de Wit, Marten; Stegen, Raf; van Cleef, Stefan

2010-03-01

225

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

226

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; Hübner, Christian A

2013-05-10

227

EVALUATION OF ULTIMATE LOAD BEARING CAPACITY OF THE PRIMARY CONTAINMENT OF FIRST GENERATION 220MWe INDIAN PHWRS  

Microsoft Academic Search

This paper presents the analysis of the Inner Containment Structure (ICS) of a typical first generation 220 MWe Indian PHWR for the purpose of evaluating its ultimate load bearing capacity (ULBC) beyond postulated design basis accident (DBA) scenario. The first generation ICS of Indian PHWRs are made of cylindrical wall capped with prestressed\\/reinforced cellular containment slab, which is connected monolithically

SINGH ASHUTOSH KUMAR; RAY INDRAJIT; ROY RAGHUPATI; R. P GARG

228

ARSENIC (III) METHYLATED SPECIES REACT WITH DNA DIRECTLY AND COULD BE PROXIMATED/ULTIMATE GENOTOXIC FORMS OF ARSENIC  

EPA Science Inventory

ARSENIC(III) METHYLATED SPECIES REACT WITH DNA DIRECTL Y AND COULD BE PROXIMATE/ULTIMATE GENOTOXIC FORMS OF ARSENIC Arsenite and arsenate (iAs, inorganic arsenic) have been thought to act as genotoxicants without reacting directly with DNA; neither iAs nor As(V) m...

229

The Utilization of Spin Polarized Photoelectron Spectroscopy as a Probe of Electron Correlation with an Ultimate Goal of Pu  

SciTech Connect

We are developing the technique of spin-polarized photoelectron spectroscopy as a probe of electron correlation with the ultimate goal of resolving the Pu electronic structure controversy. Over the last several years, we have demonstrated the utility of spin polarized photoelectron spectroscopy for determining the fine details of the electronic structure in complex systems such as those shown in this report.

Tobin, J G; Yu, S W; Chung, B W; Morton, S A; Komesu, T; Waddill, G D

2008-02-07

230

Ultimate recovery analysis by formation and play for deep Anadarko Basin and estimation of undiscovered gas potential  

SciTech Connect

Deep gas resources have assumed a growing role in the United States gas picture since the mid-1960s. The deep Anadarko basin has been one of the areas of heavy activity, and is thought to contain a significant portion of the remaining unproven deep gas resource in the lower-48 states. A detailed analysis of gas production and proven reserves in the deep basin has established the characteristics and historical importance of each of the major plays and productive formations. The analysis should prove to be a valuable tool in estimating the undiscovered gas potential of the deep basin. Through 1985, there were 908 completions in the deep Anadarko basin. These completions accounted for 6.10 tcf of proven ultimate recovery, an average of 6.72 bcf per completion. In general, there is one completion per well and one well per section. Thus, ultimate recovery per completion represents ultimate recovery per section. The Hunton Group has the highest mean ultimate recovery at 15.3 bcf, followed by the Arbuckle Group at 10.1 bcf. In an attempt to evaluate existing resource appraisals of the deep basin, the areal distribution of production by formation was determined for the mature, shallow part of the basin. Over 20,000 completions were included in this analysis, demonstrating a significant database application. By using this distribution as a guide, along with certain other constraints, a range of 15-47 tcf of undiscovered potential was estimated.

Hugman, R.H.

1988-01-01

231

Queerspawn Speak out: A Review of "Let's Get This Straight: The Ultimate Handbook for Youth with LGBTQ Parents"  

ERIC Educational Resources Information Center

"Let's Get This Straight: The Ultimate Handbook for Youth With LGBTQ Parents" provides an engaging and accessible set of tools for youth from LGBTQ-headed families. The stories and resources shared encourage these youth to take pride in their families, value their diverse experiences, and work against homophobia, transphobia, and other forms of…

Ryan, Caitlin L.

2012-01-01

232

The ‘ultimate objective’ of the framework convention on climate change requires a new approach in climate change research  

Microsoft Academic Search

In the Framework Convention on Climate Change an ‘ultimate objective’ is formulated that calls for stabilization of the concentrations of greenhouse gases in the atmosphere at a level that would allow ecosystems to adapt naturally, safeguard food supply and enable sustainable development to proceed in a sustainable manner. This paper addresses the possible contribution of science to translate this rather

Robert J. Swart; Pier Vellinga

1994-01-01

233

Grey Model for Time-Dependent Vertical Ultimate Bearing Capacity of Concrete Pile in Soft Soil Area  

Microsoft Academic Search

Determining of vertical ultimate bearing capacity (VUBC) of concrete pile is very important to design and management of geotechnical engineering in soft soil area. However, it is not well solved because the VUBC increases with time after pile installation. In this paper, conventional model for time-VUBC relationships is introduced, and one new grey model is proposed to predict time-VUBC relationships

Wang Wei; Xia Tian

2009-01-01

234

Some Physics Constraints on Ultimate Achievement in Track and Field (Alternate title: Understanding and Misunderstanding the Physics of Sports or \\  

Microsoft Academic Search

World records in track and field have improved remarkably throughout the last 100 years; however, in several events physics places quite strict limitations on ultimate performance. For example, analysis suggests that records in broad jump and pole vault have approached their optimum possible values. Physical constraints are more subtle for events such as javelin, high jump, and the distance races,

Frohlich

2002-01-01

235

Management of Ultimate Risk of Nuclear Power Plants by Source Terms - Lessons Learned from the Chernobyl Accident  

Microsoft Academic Search

The term 'ultimate risk' is used here to describe the probabilities and radiological consequences that should be incorporated in siting, containment design and accident management of nuclear power plants for hypothetical accidents. It is closely related with the source terms specified in siting criteria which assures an adequate separation of radioactive inventories of the plants from the public, in the

Genn Saji

2006-01-01

236

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 7.618±0.008 (spectrophotometric) and

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

2002-01-01

237

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

238

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

239

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

240

Coral resilience to ocean acidification and global warming through pH up-regulation  

NASA Astrophysics Data System (ADS)

Rapidly rising levels of atmospheric CO2 are not only causing ocean warming, but also lowering seawater pH hence the carbonate saturation state of the oceans, on which many marine organisms depend to calcify their skeletons. Using boron isotope systematics, we show how scleractinian corals up-regulate pH at their site of calcification such that internal changes are approximately one-half of those in ambient seawater. This species-dependent pH-buffering capacity enables aragonitic corals to raise the saturation state of their calcifying medium, thereby increasing calcification rates at little additional energy cost. Using a model of pH regulation combined with abiotic calcification, we show that the enhanced kinetics of calcification owing to higher temperatures has the potential to counter the effects of ocean acidification. Up-regulation of pH, however, is not ubiquitous among calcifying organisms; those lacking this ability are likely to undergo severe declines in calcification as CO2 levels increase. The capacity to up-regulate pH is thus central to the resilience of calcifiers to ocean acidification, although the fate of zooxanthellate corals ultimately depends on the ability of both the photosymbionts and coral host to adapt to rapidly increasing ocean temperatures.

McCulloch, Malcolm; Falter, Jim; Trotter, Julie; Montagna, Paolo

2012-08-01

241

Surfactant choice and the physical stability of nanosuspensions as a function of pH.  

PubMed

Nanosuspensions of the example compounds ketoconazole and itraconazole were shown to aggregate upon reducing the pH to levels comparable to that known to exist in the stomach. Manipulation of the surfactant/polymer ratio in the suspension vehicle did not elucidate the cause of the aggregation. X-ray diffraction on ketoconazole solids failed to identify a form change as causative. Ultimately, ketoconazole intrinsic dissolution rate experiments implicated surface salt formation between ketoconazole and the vehicle surfactant as the cause of the aggregation. The generality of the phenomenon is discussed. PMID:22982488

Donoso, Maria D; Haskell, Roy J; Schartman, Richard R

2012-09-14

242

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

243

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

244

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

245

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

246

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.

247

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.

248

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. Ēal??kan; E. R. Tan; C.-Y. Wang; J. Zhou

2009-01-01

249

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

250

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...

251

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

252

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

253

New Three-Dimensional Integration Technology Using Chip-to-Wafer Bonding to Achieve Ultimate Super-Chip Integration  

Microsoft Academic Search

A new three-dimensional (3D) integration technology using the chip-to-wafer bonding technique provides the ultimate super-chip integration in which various kinds of chip of different sizes can be vertically stacked and electrically connected through a number of vertical interconnections. We have investigated several key technologies of vertical interconnection formation, chip alignment, chip-to-wafer bonding, adhesive injection, and chip thinning to vertically stack

Takafumi Fukushima; Yusuke Yamada; Hirokazu Kikuchi; Mitsumasa Koyanagi

2006-01-01

254

A Simple Limit Equilibrium Approach for Calculation of Ultimate Bearing Capacity of Shallow Foundations on Two-Layered Granular Soils  

Microsoft Academic Search

The bearing capacity of shallow foundations in a non-homogeneous soil profile has been a challenging task in geotechnical\\u000a engineering. In this paper, a limit equilibrium method is used for calculating bearing capacity factors of shallow foundations\\u000a constructed on a two-layered granular soil profile. The main objective has been to determine the ultimate bearing capacity\\u000a computed from equivalent bearing capacity factors

Mahmoud Ghazavi; Amir Hossein Eghbali

2008-01-01

255

ULTIMATE STRENGTH AND POSTBUCKLING STIFFNESS OF PLATE PANELS SUBJECTED TO COMBINED LOADS USING SEMI-ANALYTICAL MODELS  

Microsoft Academic Search

SUMMARY Non-linear semi-analytical buckling models are deve loped for fast and accurate buckling, postbuckling and ultimate strength assessment of thin-walled plate panels. Th e models are founded on thin-walled large deflectio n plate theory, Raleigh-Ritz discretization of the buckling deflect ion and incremental methods for solving the geometr ically non-linear equilibrium equations. By limiting the degrees of f reedom and

Eivind Steen; Eirik Byklum

2005-01-01

256

Full-scale long-term and ultimate experiments of simply-supported composite beams with steel deck  

Microsoft Academic Search

This paper presents the details of an experimental study carried out on two full-scale simply-supported composite steel–concrete beams to investigate their long-term behaviour and how this affects their ultimate response. The specimens were formed by a steel joist and a concrete slab with steel deck, and possessed identical spans and cross-sections. The ribs of the steel deck were orthogonal to

Safat Al-deen; Gianluca Ranzi; Zora Vrcelj

2011-01-01

257

Can the chemical reactivity of an ultimate carcinogen be related to its carcinogenicity? An application to propylene oxide.  

PubMed

In this article we report calculations of the activation free energy for a chemical reaction between propylene oxide and DNA, in particular with the guanine at the N7 position. Calculations were performed using Hartree-Fock and MP2 methods in conjunction with flexible basis sets. The effects of solvation were considered using the Langevin dipoles and solvent reaction field methods. The calculated activation free energies are in good agreement with the experimental value of 25.36 kcal/mol. Moreover, the reactivities of a series of ultimate carcinogens of the epoxy type toward DNA are shown to be related to their carcinogenicities. Higher reactivity is generally associated with higher carcinogenicity, although transport properties, reactions with ultimate carcinogen scavengers, and the DNA correction mechanism are also very important. It is very likely that the window of reactivity rather than a high reactivity value is the relevant measure of carcinogenicity, since highly reactive ultimate carcinogens interact with water and proteins before they reach DNA. PMID:22889582

Mavri, Janez

2012-08-05

258

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

259

Effective endogenous gene silencing mediated by pH responsive peptides proceeds via multiple pathways  

PubMed Central

Cationic amphipathic histidine rich peptides possess high plasmid DNA and siRNA delivery capabilities. To further understand the pH responsive siRNA delivery process and evaluate the capabilities of such peptides we have investigated their ability to mediate specific silencing of endogenous GAPDH gene activity in MCF-7 and A549 cells and compared this with plasmid DNA delivery. A substantial and selective reduction of both GAPDH activity and expression was achieved using pH responsive peptide vectors, which compared favourably with that mediated by commercially available non-viral vectors in terms of efficacy and toxicity. Furthermore, by comparing the efficacy of both gene delivery and silencing mediated by a series of such peptides, their sensitivities to known inhibitors of endocytotic processes, and their route of uptake via confocal live cell imaging, we show that both plasmid DNA and siRNA are internalised via endocytosis. However siRNA entry facilitated by LAH4-L1, proceeds via a cholesterol dependent mechanism, in contrast to DNA transfer which is associated with clathrin dependent endocytosis. Furthermore, using peptides that respond at increasingly acidic pH, we demonstrate that the route of entry for the siRNA that ultimately mediates silencing is peptide specific and while some pH responsive peptides promote the escape of labelled siRNA from endosomes, others may promote entry via alternative mechanisms.

Lam, Jenny. K.W.; Liang, Wanling; Lan, Yun; Chaudhuri, Poulami; Chow, Michael Y.T.; Witt, Katarzyna; Kudsiova, Laila; Mason, A. James

2012-01-01

260

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

261

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

262

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

263

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

264

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

Jürgen Breidung; Walter Thiel; Jean Demaison

1997-01-01

265

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

266

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 CaClā 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

267

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

268

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

269

Large-deflection-theory Analysis of the Effect of Web Initial Curvature on the Ultimate Strength of Steel Plate Girder  

NASA Astrophysics Data System (ADS)

The objective of the paper is to analyze the influence of initial imperfections on the behaviour of thin-walled girders welded of slender plate elements. In parallel with experiments, one of the ultimate load tests was computer modelled. In so doing, the girder was modelled, using the geometrically and materially non-linear variant of the shell finite element method, by the ANSYS program. The shape changing during loading process is often accompanying with sudden ``snap-through'' i. e. rapid curvature change.

Kala, Ji?ķ; Kala, Zden?k

2011-09-01

270

Material Properties Test to Determine Ultimate Strain and True Stress-True Strain Curves for High Yield Steels  

SciTech Connect

This testing was undertaken to develop material true stress-true strain curves for elastic-plastic material behavior for use in performing transient analysis. Based on the conclusions of this test, the true stress-true strain curves derived herein are valid for use in elastic-plastic finite element analysis for structures fabricated from these materials. In addition, for the materials tested herein, the ultimate strain values are greater than those values cited as the limits for the elastic-plastic strain acceptance criteria for transient analysis.

K.R. Arpin; T.F. Trimble

2003-04-01

271

The Utilization of Spin Polarized Photoelectron Spectroscopy as a Probe of Electron Correlation with an Ultimate Goal of Pu  

SciTech Connect

We are developing the technique of spin-polarized photoelectron spectroscopy as a probe of electron correlation with the ultimate goal of resolving the Pu electronic structure controversy. Over the last several years, we have demonstrated the utility of spin polarized photoelectron spectroscopy for determining the fine details of the electronic structure in complex systems such as those shown in this paper. Various recent publications have addressed the ongoing question of the nature of the Pu electronic structure. One possibility is the existence of a Kondo-like shielding of the 5f electrons. We propose that spin resolved PES is the most promising approach to resolving this question. (authors)

Tobin, J.G.; Yu, S.W.; Chung, B.W. [LLNL, Livermore, CA, 94550 (United States); Morton, S.A. [LLNL, Livermore, CA, 94550 (United States)]|[LBNL, Berkeley, CA, 94720 (United States); Komesu, T.; Waddill, G.D. [Missouri University of Science and Technology, Rolla, MO, 65401 (United States)

2008-07-01

272

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

273

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.

274

Nanofluidic single-molecule sorting of DNA: a new concept in separation and analysis of biomolecules towards ultimate level performance  

NASA Astrophysics Data System (ADS)

Separation and separation-based analysis of biomolecules are fundamentally important techniques in the field of biotechnology. These techniques, however, depend on stochastic processes that intrinsically involve uncertainty, and thus it is not possible to achieve 100% separation accuracy. Theoretically, the ultimate resolution and sensitivity should be realized in a single-molecule system because of the deterministic nature of single-molecule manipulation. Here, we have proposed and experimentally demonstrated the concept of a 'single-molecule sorter' that detects and correctly identifies individual single molecules, realizing the ultimate level of resolution and sensitivity for any separation-based technology. The single-molecule sorter was created using a nanofluidic network consisting of a single inlet channel that branches off into multiple outlet channels. It includes two major functional elements, namely a single-molecule detection and identification element and a flow path switching element to accurately separate single molecules. With this system we have successfully demonstrated the world's first single-molecule sorting using DNA as a sample molecule. In the future, we hope to expand the application of such devices to comprehensive sorting of single-proteins from a single cell. We also believe that in addition to the single-molecule sorting method reported here, other types of single-molecule based processes will emerge and find use in a wide variety of applications.

Yamamoto, Takatoki; Fujii, Teruo

2010-10-01

275

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.

276

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.

277

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

278

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

279

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

280

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

281

Acidified seawater impacts sea urchin larvae pH regulatory systems relevant for calcification.  

PubMed

Calcifying echinoid larvae respond to changes in seawater carbonate chemistry with reduced growth and developmental delay. To date, no information exists on how ocean acidification acts on pH homeostasis in echinoderm larvae. Understanding acid-base regulatory capacities is important because intracellular formation and maintenance of the calcium carbonate skeleton is dependent on pH homeostasis. Using H(+)-selective microelectrodes and the pH-sensitive fluorescent dye BCECF, we conducted in vivo measurements of extracellular and intracellular pH (pH(e) and pH(i)) in echinoderm larvae. We exposed pluteus larvae to a range of seawater CO(2) conditions and demonstrated that the extracellular compartment surrounding the calcifying primary mesenchyme cells (PMCs) conforms to the surrounding seawater with respect to pH during exposure to elevated seawater pCO(2). Using FITC dextran conjugates, we demonstrate that sea urchin larvae have a leaky integument. PMCs and spicules are therefore directly exposed to strong changes in pH(e) whenever seawater pH changes. However, measurements of pH(i) demonstrated that PMCs are able to fully compensate an induced intracellular acidosis. This was highly dependent on Na(+) and HCO(3)(-), suggesting a bicarbonate buffer mechanism involving secondary active Na(+)-dependent membrane transport proteins. We suggest that, under ocean acidification, maintained pH(i) enables calcification to proceed despite decreased pH(e). However, this probably causes enhanced costs. Increased costs for calcification or cellular homeostasis can be one of the main factors leading to modifications in energy partitioning, which then impacts growth and, ultimately, results in increased mortality of echinoid larvae during the pelagic life stage. PMID:23077257

Stumpp, Meike; Hu, Marian Y; Melzner, Frank; Gutowska, Magdalena A; Dorey, Narimane; Himmerkus, Nina; Holtmann, Wiebke C; Dupont, Sam T; Thorndyke, Michael C; Bleich, Markus

2012-10-17

282

Acidified seawater impacts sea urchin larvae pH regulatory systems relevant for calcification  

PubMed Central

Calcifying echinoid larvae respond to changes in seawater carbonate chemistry with reduced growth and developmental delay. To date, no information exists on how ocean acidification acts on pH homeostasis in echinoderm larvae. Understanding acid–base regulatory capacities is important because intracellular formation and maintenance of the calcium carbonate skeleton is dependent on pH homeostasis. Using H+-selective microelectrodes and the pH-sensitive fluorescent dye BCECF, we conducted in vivo measurements of extracellular and intracellular pH (pHe and pHi) in echinoderm larvae. We exposed pluteus larvae to a range of seawater CO2 conditions and demonstrated that the extracellular compartment surrounding the calcifying primary mesenchyme cells (PMCs) conforms to the surrounding seawater with respect to pH during exposure to elevated seawater pCO2. Using FITC dextran conjugates, we demonstrate that sea urchin larvae have a leaky integument. PMCs and spicules are therefore directly exposed to strong changes in pHe whenever seawater pH changes. However, measurements of pHi demonstrated that PMCs are able to fully compensate an induced intracellular acidosis. This was highly dependent on Na+ and HCO3?, suggesting a bicarbonate buffer mechanism involving secondary active Na+-dependent membrane transport proteins. We suggest that, under ocean acidification, maintained pHi enables calcification to proceed despite decreased pHe. However, this probably causes enhanced costs. Increased costs for calcification or cellular homeostasis can be one of the main factors leading to modifications in energy partitioning, which then impacts growth and, ultimately, results in increased mortality of echinoid larvae during the pelagic life stage.

Stumpp, Meike; Hu, Marian Y.; Melzner, Frank; Gutowska, Magdalena A.; Dorey, Narimane; Himmerkus, Nina; Holtmann, Wiebke C.; Dupont, Sam T.; Thorndyke, Michael C.; Bleich, Markus

2012-01-01

283

CNET's Ultimate Processor Guide  

NSDL National Science Digital Library

This new special report from CNET is offered as a guide to "everything you need to know about processors." Users shopping for a new PC will want to start with the Know Your CPU section, which offers a set of flash cards on the most popular processors. Those interested in the higher-end chips will want to read the Athlon vs. Pentium III Shoot-Out section, which compares features and performance.The more curious and technical-minded will also be interested in the Supersonic Chips section, which explains what makes chips fast and speculates on future speeds. Finally, the DIY user may want to review Upgrading Your CPU and The Trouble With Overclocking, the latter of which explores the pros and cons of overclocking CPUs.

Blachere, Kristina.

284

The ultimate curse.  

PubMed Central

This paper tells the story of a doctor in a vegetative state. The approach towards him is quite different from that towards a common patient. The other physicians cannot deal with this situation with the necessary open mind.

Crisci, C

1995-01-01

285

The Ultimate Private Observatory  

NASA Astrophysics Data System (ADS)

An amateur astronomer from Washington Parish, Southeast Louisiana, USA has designed and built an amazing observatory. It is not only an astronomical observatory, but a home theater, and tornado shelter designed to take a direct hit from an F5 tornado. The facility is fully equipped and automated, with a hydraulically driven roof that weighs 20,571 lbs., which lifts up, then rolls away to the end of the tracks. This leaves the user sitting inside of four 14-foot high walls open to the night sky. It has two premium quality telescopes for viewing deep space and objects inside the solar system. The chair that the observer sits on is also hydraulically driven.

Aymond, J.

2009-03-01

286

Estimating the ultimate bound and positively invariant set for the Lorenz system and a unified chaotic system  

NASA Astrophysics Data System (ADS)

To estimate the ultimate bound and positively invariant set for a dynamic system is an important but quite challenging task in general. In this paper, we attempt to investigate the ultimate bound and positively invariant set for two specific systems, the Lorenz system and a unified chaotic system. We derive an ellipsoidal estimate of the ultimate bound and positively invariant set for the Lorenz system, for all the positive values of its parameters a, b and c, and obtain the minimum value of volume for the ellipsoid. Comparing with the best results in the current literature [D. Li, J. Lu, X. Wu, G. Chen, Estimating the bounds for the Lorenz family of chaotic systems, Chaos Solitons Fractals 23 (2005) 529-534; X. Liao, On the global basin of attraction and positively invariant set for the Lorenz chaotic system and its application in chaos control and synchronization, Sci. China Ser. E 34 (2004) 1404-1419], our new results fill up the gap of the estimate for the cases of 0

Li, Damei; Lu, Jun-An; Wu, Xiaoqun; Chen, Guanrong

2006-11-01

287

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

288

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

289

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

290

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

291

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

292

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

293

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

294

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

295

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

296

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

297

The Effects of Salinity, pH, and Dissolved Organic Matter on Acute Copper Toxicity to the Rotifer, Brachionus plicatilis (“L” Strain)  

Microsoft Academic Search

This paper presents data from original research for use in the development of a marine biotic ligand model and, ultimately,\\u000a copper criteria for the protection of estuarine and marine organisms and their uses. Ten 48-h static acute (unfed) copper\\u000a toxicity tests using the euryhaline rotifer Brachionus plicatilis (“L” strain) were performed to assess the effects of salinity, pH, and dissolved

W. R. Arnold; R. L. Diamond; D. S. Smith

2010-01-01

298

Stress-resultant models for ultimate load design of reinforced concrete frames and multi-scale parameter estimates  

NASA Astrophysics Data System (ADS)

In this work, we present a new finite element for (geometrically linear) Timoshenko beam model for ultimate load computation of reinforced concrete frames. The proposed model combines the descriptions of the diffuse plastic failure in the beam-column followed by the creation of plastic hinges due to the failure or collapse of the concrete and of the re-bars. A modified multi-scale analysis is performed in order to identify the parameters for stress-resultant-based macro model, which is used to described the behavior of the Timoshenko beam element. For clarity, we focus upon the micro-scale models using the multi-fiber elements with embedded displacement discontinuities in mode I, which would typically be triggered by bending failure mode. More general case of micro-scale model capable of describing shear failure is described by Ibrahimbegovic et al. (Int J Numer Methods Eng 83(4):452-481, 2010).

Pham, B. H.; Brancherie, D.; Davenne, L.; Ibrahimbegovic, A.

2013-03-01

299

Measuring the Ultimate Halo Mass of Galaxy Clusters: Redshifts and Mass Profiles from the Hectospec Cluster Survey (HeCS)  

NASA Astrophysics Data System (ADS)

The infall regions of galaxy clusters represent the largest gravitationally bound structures in a ?CDM universe. Measuring cluster mass profiles into the infall regions provides an estimate of the ultimate mass of these halos. We use the caustic technique to measure cluster mass profiles from galaxy redshifts obtained with the Hectospec Cluster Survey (HeCS), an extensive spectroscopic survey of galaxy clusters with MMT/Hectospec. We survey 58 clusters selected by X-ray flux at 0.1 < z < 0.3. The survey includes 22,680 unique MMT/Hectospec redshifts for individual galaxies; 10,145 of these galaxies are cluster members. For each cluster, we acquired high signal-to-noise spectra for ~200 cluster members and a comparable number of foreground/background galaxies. The cluster members trace out infall patterns around the clusters. The members define a very narrow red sequence. We demonstrate that the determination of velocity dispersion is insensitive to the inclusion of bluer members (a small fraction of the cluster population). We apply the caustic technique to define membership and estimate the mass profiles to large radii. The ultimate halo mass of clusters (the mass that remains bound in the far future of a ?CDM universe) is on average (1.99 ± 0.11)M 200, a new observational cosmological test in essential agreement with simulations. Summed profiles binned in M 200 and in LX demonstrate that the predicted Navarro-Frenk-White form of the density profile is a remarkably good representation of the data in agreement with weak lensing results extending to large radius. The concentration of these summed profiles is also consistent with theoretical predictions.

Rines, Kenneth; Geller, Margaret J.; Diaferio, Antonaldo; Kurtz, Michael J.

2013-04-01

300

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

Pįger, Csilla; Vargovį, Andrea; Takįcsi-Nagy, Anna; Dörnyei, Įgnes; Kilįr, Ferenc

2012-10-22

301

17 CFR 240.15c3-1g - Conditions for ultimate holding companies of certain brokers or dealers (Appendix G to 17 CFR 240...  

Code of Federal Regulations, 2013 CFR

...holding company's fiscal year, filed with the Commission when required to be filed by any regulator; (3...appendix G will be considered filed when two copies are received...results of funding and liquidity stress tests that the ultimate...

2013-04-01

302

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

303

Effect of pre-slaughter physiological conditions on the oxidative stability of colour and lipid during chill storage of pork.  

PubMed

The physiological condition of the live animal was found to significantly affect colour, lipid oxidation and water holding capacity of chill stored pork chops (M. Longissimus dorsi) in a study, where various pre-slaughter conditions were achieved by the following four treatments: (A) control; (B) subjected to treadmill exercise immediately prior to stunning; (C) given epinephrine injection 15 h prior to slaughter; and (D) given epinephrine injection 15 h before slaughter and further subjected to treadmill exercise immediately before stunning. The treatments resulted in variations in energy metabolites (glycogen, lactate, creatine phosphate, ATP) and ultimate pH (pH(u)), with the lowest pH(u) in chops from treatments A and B, and in significantly different tristimulus colour L(?)-, a(?)- and b(?)-parameters, although the effect of treatment on colour was not consistent during the chill storage period of 6 days. Overall, chops from treatments A and B had significantly higher L(?)- and b(?)-values (were paler and less blue) than chops from C and D during storage under conditions typical for retail trade. The initial a(?)-values were higher (redder) in chops from treatments A and B, but the colour, as judged by the a(?)-values, was less stable in meat from these treatments compared with treatments C and D. Lipid oxidation, evaluated by thiobarbituric acid reactive substances (TBARS) in the fresh meat, and drip loss, measured after 6 days of storage, were both significantly higher in chops from treatments A and B compared to chops obtained from treatments C and D. Statistical analysis relating the pH and the level of various energy metabolites post-mortem in the individual animals to the measured quality parameters, revealed that pH(u) was the most important factor affecting product quality. In conclusion, over all product quality depends on obtaining a pH(u) in the narrow range where both meat quality parameters such as colour, lipid oxidation and drip loss as well as microbiological aspects have to be considered. PMID:22062424

Juncher, D; Rųnn, B; Mortensen, E; Henckel, P; Karlsson, A; Skibsted, L; Bertelsen, G

2001-08-01

304

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

305

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

306

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

307

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

308

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.

309

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.

310

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

311

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

312

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.

313

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, King’s College, University of London, 2000). – selections (provided in

George Ille

2003-01-01

314

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

315

Management of Ultimate Risk of Nuclear Power Plants by Source Terms - Lessons Learned from the Chernobyl Accident  

SciTech Connect

The term 'ultimate risk' is used here to describe the probabilities and radiological consequences that should be incorporated in siting, containment design and accident management of nuclear power plants for hypothetical accidents. It is closely related with the source terms specified in siting criteria which assures an adequate separation of radioactive inventories of the plants from the public, in the event of a hypothetical and severe accident situation. The author would like to point out that current source terms which are based on the information from the Windscale accident (1957) through TID-14844 are very outdated and do not incorporate lessons learned from either the Three Miles Island (TMI, 1979) nor Chernobyl accident (1986), two of the most severe accidents ever experienced. As a result of the observations of benign radionuclides released at TMI, the technical community in the US felt that a more realistic evaluation of severe reactor accident source terms was necessary. In this background, the 'source term research project' was organized in 1984 to respond to these challenges. Unfortunately, soon after the time of the final report from this project was released, the Chernobyl accident occurred. Due to the enormous consequences induced by then accident, the one time optimistic perspectives in establishing a more realistic source term were completely shattered. The Chernobyl accident, with its human death toll and dispersion of a large part of the fission fragments inventories into the environment, created a significant degradation in the public's acceptance of nuclear energy throughout the world. In spite of this, nuclear communities have been prudent in responding to the public's anxiety towards the ultimate safety of nuclear plants, since there still remained many unknown points revolving around the mechanism of the Chernobyl accident. In order to resolve some of these mysteries, the author has performed a scoping study of the dispersion and deposition mechanisms of fuel particles and fission fragments during the initial phase of the Chernobyl accident. Through this study, it is now possible to generally reconstruct the radiological consequences by using a dispersion calculation technique, combined with the meteorological data at the time of the accident and land contamination densities of {sup 137}Cs measured and reported around the Chernobyl area. Although it is challenging to incorporate lessons learned from the Chernobyl accident into the source term issues, the author has already developed an example of safety goals by incorporating the radiological consequences of the accident. The example provides safety goals by specifying source term releases in a graded approach in combination with probabilities, i.e. risks. The author believes that the future source term specification should be directly linked with safety goals. (author)

Genn Saji [Ex-Secretariate of Nuclear Safety Commission of Japan (Japan)

2006-07-01

316

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

317

Development of FRP composite structural biomaterials: ultimate strength of the fiber/matrix interfacial bond in in vivo simulated environments.  

PubMed

Fiber reinforced polymer (FRP) composites are being developed as alternatives to metals for structural orthopedic implant applications. FRP composite fracture behavior and environmental interactions are distinctly different from those which occur in metals. These differences must be accounted for in the design and evaluation of implant performance. Fiber/matrix interfacial bond strength in a FRP composite is known to strongly influence fracture behavior. The interfacial bond strength of four candidate fiber/matrix combinations (carbon fiber/polycarbonate, carbon fiber/polysulfone, polyaramid fiber/polycarbonate, polyaramid fiber/polysulfone) were investigated at 37 degrees C in dry and in vivo simulated (saline, exudate) environments. Ultimate bond strength was measured by a single fiber-microdroplet pull-out test. Dry bond strengths were significantly decreased following exposure to either saline or exudate with bond strength loss being approximately equal in both the saline and exudate. Bond strength loss is attributed to the diffusion of water and/or salt ions into the sample and their interaction with interfacial bonding. Because bond degradation is dependent upon diffusion, diffusional equilibrium must be obtained in composite test samples before the full effect of the test environment upon composite mechanical behavior can be determined. PMID:1512281

Latour, R A; Black, J

1992-05-01

318

Imaging-genetics in dyslexia: Connecting risk genetic variants to brain neuroimaging and ultimately to reading impairments.  

PubMed

Dyslexia is a common pediatric disorder that affects 5-17% of schoolchildren in the United States. It is marked by unexpected difficulties in fluent reading despite adequate intelligence, opportunity, and instruction. Classically, neuropsychologists have studied dyslexia using a variety of neurocognitive batteries to gain insight into the specific deficits and impairments in affected children. Since dyslexia is a complex genetic trait with high heritability, analyses conditioned on performance on these neurocognitive batteries have been used to try to identify associated genes. This has led to some successes in identifying contributing genes, although much of the heritability remains unexplained. Additionally, the lack of relevant human brain tissue for analysis and the challenges of modeling a uniquely human trait in animals are barriers to advancing our knowledge of the underlying pathophysiology. In vivo imaging technologies, however, present new opportunities to examine dyslexia and reading skills in a clearly relevant context in human subjects. Recent investigations have started to integrate these imaging data with genetic data in attempts to gain a more complete and complex understanding of reading processes. In addition to bridging the gap from genetic risk variant to a discernible neuroimaging phenotype and ultimately to the clinical impairments in reading performance, the use of neuroimaging phenotypes will reveal novel risk genes and variants. In this article, we briefly discuss the genetic and imaging investigations and take an in-depth look at the recent imaging-genetics investigations of dyslexia. PMID:23916419

Eicher, John D; Gruen, Jeffrey R

2013-07-17

319

Calculation of calorific values of coals from ultimate analyses: theoretical basis and geochemical implications. Final report. Part 8  

SciTech Connect

The various formulae for calculating calorific values for coals from ultimate analyses depend essentially on a propositon due to Dulong, that the heat of combustion of an organic compound is nearly equal to the heats of combustion of the elements in it, multiplied by their percentage content in the compound in question. This proposition assumes that the enthalpy of decomposition is negligible compared with the heat of combustion. The various published formulae, such as that due to Mott and Spooner, include empirical adjustments to allow for the fact that the enthalpy of formation or decomposition of no organic compound is zero (except rarely by chance). A new equation is proposed, which excludes empirical correction terms but includes a term explicitly related to the enthalpy of decomposition. As expected from the behavior of known compounds, this enthalpy varies with rank, but it also varies at the same level of rank with the geological history of the sample: rank is not the only source of variance in coal properties. The new equation is at least as effective in predicting calorific values for a set of 992 coals as equivalent equations derived for 6 subsets of the coals. On the whole, the distributions of differences between observed and calculated calorific values are skewed to only a small extent. About 86% of the differences lie between -300 and +300 Btu/lb (+- 700 kJ/kg). 10 references, 7 figures, 4 tables.

Given, P.H.; Weldon, D.; Zoeller, J.H.

1984-03-01

320

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 Nbā(PhCC(Ph)C(Ph)CPh) moiety. Compound 1, (NbāOāClā((PhC)ā)ā(THF)ā) Ć 2THF, contains centrosymmetric tetranuclear molecules in which the equivalent halves, Nbā((PhC)ā)Clā(THF)āO, are joined solely by having the Ī¼-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 P2ā\\/c

F. A. Cotton; Maoyu Shang

1990-01-01

321

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

322

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

323

[Pharmacognostical studies on adiantum plants. V. Classification based on spore morphology and distributional patterns of silicon and calcium in the ultimate pinnules].  

PubMed

Crude drugs derived from Adiantum species are used as febrifuge, antidote, diuretic, tonic, etc. Some commercial samples of these drugs are composed of finely cut ultimate pinnules only, which have false indusia and spores. In this paper, in order to establish a classification method based on the characteristics of the ultimate pinnules and their attachments, the morphological study using stereoscope and scanning electron microscope, and X-ray microanalysis using an electron probe microanalyzer were carried out on the false indusia and spores, and the ultimate pinnules, respectively, of 19 Adiantum species. The results showed that examined all species could be distinguished from each other by the following characteristics: in the false indusium, the shape and the presence or absence of hairs; in the spore, the shape, the ornamentation, the ratio of the laesura, and the equatorial diameter; in the X-ray images of the ultimate pinnule, the distributional patterns of silicon and calcium. The distributional patterns of silicon were due to the presence of spicular cells, hairs and papillae, and calcium was present as crystals of calcium oxalate. The average content of silicon in the ultimate pinnules of Adiantum species was 1.99%. PMID:8717279

Komatsu, K; Iida, K; Cai, S Q; Mikage, M; Yoshizawa, T

1996-02-01

324

Perceived Success and Competence of the Opponent, or the Laboratory Dien Bien Phu.  

National Technical Information Service (NTIS)

The effect of information relevance and information availability on perceptual differences between Chinese and American nationals was investigated. Subjects participated in pairs as decision makers in a complex experimental environment. Participants' perc...

S. Streufert S. I. Sandler

1973-01-01

325

Effects of Environmental pH on the Internal pH of Chlorella pyrenoidosa, Scenedesmus quadricauda, and Euglena mutabilis.  

PubMed

The effect of external pH on two laboratory-cultured acid-intolerant species (Chlorella pyrenoidosa Chick and Scenedesmus quadricauda Turp. Bréb.) and one acid-tolerant species from a natural population (Euglena mutabilis Schmitz) was examined by measuring internal pH. These measurements were made with the weak acid (14)C-dimethyloxazolidine-2,4-dione after cells had been incubated for 2 and 6 hours at external pH levels from 3.0 to 8.0. Photosynthetic and respiration rates of the three species were also measured over the range of external pH levels.All three species regulated their internal pH levels over the 6-hour incubation time. C. pyrenoidosa and S. quadricauda had internal pH levels around 7.0, regardless of external pH. E. mutabilis had a wider internal pH range, from 5.0 at low external pH to 8.0 at high external pH. External pH had no effect on either photosynthetic or respiration rates. Statistical comparisons showed that there was a significant difference between the acid-intolerant and acid-tolerant species with regard to the level of internal pH maintained and the response of internal pH to external pH. PMID:16661932

Lane, A E; Burris, J E

1981-08-01

326

Application of SERS Nanoparticles for Intracellular pH Measurements.  

National Technical Information Service (NTIS)

We present an alternative approach to optical probes that will ultimately allow us to measure chemical concentrations in microenvironments within cells and tissues. This approach is based on monitoring the surface-enhanced Raman scattering (SERS) response...

T. Laurence C. Talley M. Colvin T. Huser

2004-01-01

327

The pH of Mars  

NASA Astrophysics Data System (ADS)

The Viking labeled release (LR) experiments provided data that can be used to determine the acid-base characteristics of the regolith. Constraints on the acid-base properties and redox potentials of the Martian surface material would provide additional information for determining what reactions are possible and defining formation conditions for the regolith. Calculations devised to determine the pH of Mars must include the amount of soluble acid species or base species present in the LR regolith sample and the solubility product of the carbonate with the limiting solubility. This analysis shows that CaCO3, either as calcite or aragonite, has the correct Ksp to have produced the Viking LR successive injection reabsorption effects. Thus CaCO3 or another MeCO3 with very similar solubility characteristics must have been present on Mars. A small amount of soluble acid, but no more than 4 micro-mol per sample, could also have been present. It is concluded that the pH of the regolith is 7.2 +/- 0.1.

Plumb, R. C.; Bishop, J. L.; Edwards, J. O.

328

PhET Simulation: Balancing Chemical Equations  

NSDL National Science Digital Library

This simulation provides practice for beginners in balancing chemical equations. Introductory activities include separating a water molecule and making ammonia (a compound composed of sodium and hydrogen). The user clicks up or down arrows to add/delete atoms, while bar charts and balance scales are displayed to show when the equation is in balance. Next, apply what you've learned and play the "Balancing Game", with three levels of difficulty. Editor's Note: The game-like nature of this activity not only gives students practice with chemical equations, but goes much deeper. By viewing the distribution of individual atoms in real-time charts alongside the equation, the learner is building a basis to understand conservation of matter and chemical interactions. See Related Materials for a link to downloadable lessons and student guides developed specifically for use with this PhET simulation. This item is part of a larger collection of simulations developed by the Physics Education Technology project (PhET).

2011-08-15

329

Noninvasive pH Monitoring in Platelet Concentrates  

PubMed Central

Summary Background New technology introduces the option to measure pH in platelet concentrates noninvasively. Findings that in one out of 25 apheresis concentrates the pH decreased significantly during storage motivated us to evaluate apheresis concentrates from 307 platelet donors. Methods Small (15 ml) BSCI storage containers for noninvasive pH measurement were used in parallel with Fenwal PL2400 bags for storage of 5 days. Noninvasive pH measurement was compared to pH determination in samples from the storage container. Decrease of pH during storage was calculated as ?pH d2-d5. Results The coefficient of correlation for noninvasive pH measurement (n = 256) versus standard methods was R2 = 0.964 (pH electrode) or 0.952 (ABL 510). pH values in BSCI bags were slightly lower than in Fenwal PL2400 containers. Concentrates collected from 8 of the 307 donors showed a significant drop in pH. Repeated collection did not confirm these findings with a single exception. Conclusion Noninvasive pH measurement demonstrates a high reproducibility. Our study could not confirm the frequency of 1 out of 25 plateletpheresis donors with concentrates developing a significant drop in pH during storage. This may be due to a substantially lower platelet concentration in our preparations.

Doescher, Andrea; Muller, Thomas H.

2013-01-01

330

Effects of conventional welding and laser welding on the tensile strength, ultimate tensile strength and surface characteristics of two cobalt-chromium alloys: a comparative study.  

PubMed

The purpose of this study was to evaluate the efficacy of laser welding and conventional welding on the tensile strength and ultimate tensile strength of the cobalt-chromium alloy. Samples were prepared with two commercially available cobalt-chromium alloys (Wironium plus and Diadur alloy). The samples were sectioned and the broken fragments were joined using Conventional and Laser welding techniques. The welded joints were subjected to tensile and ultimate tensile strength testing; and scanning electron microscope to evaluate the surface characteristics at the welded site. Both on laser welding as well as on conventional welding technique, Diadur alloy samples showed lesser values when tested for tensile and ultimate tensile strength when compared to Wironium alloy samples. Under the scanning electron microscope, the laser welded joints show uniform welding and continuous molt pool all over the surface with less porosity than the conventionally welded joints. Laser welding is an advantageous method of connecting or repairing cast metal prosthetic frameworks. PMID:23858281

Madhan Kumar, Seenivasan; Sethumadhava, Jayesh Raghavendra; Anand Kumar, Vaidyanathan; Manita, Grover

2012-04-18

331

CRCHD - CRCHD Research - Principal Investigator: Jamil Momand, Ph.D.  

Cancer.gov

CRCHD - CRCHD Research - Principal Investigator: Jamil Momand, Ph.D. Home Disparities Research Programs CRCHD Ongoing Research PACHE PACHE Partnership Listing Jamil Momand, Ph.D. CRCHD Research Ongoing Research

332

CRCHD - CRCHD Research - Principal Investigator: Jamil Momand, Ph.D.  

Cancer.gov

CRCHD - CRCHD Research - Principal Investigator: Jamil Momand, Ph.D. Home Health Disparities Research CRCHD Research Ongoing Research PACHE PACHE Partnership Listing Jamil Momand, Ph.D. CRCHD Research Ongoing

333

Conceptual model of digital pH meter in telemedicine  

Microsoft Academic Search

pH level plays a vital role in the maintenance of human metabolic activity. pH levels of different bodily fluids i.e. blood, serum, urine etc are important parameters in diagnosing any condition, as unbalanced pH levels can interrupt all cellular activities and corrodes body tissues. In this paper a concept of implementing pH parameters in HL7v3 that is XML based is

Rabiya Rehman; Murtaza Halai

2011-01-01

334

Use and abuse of pH measurements  

Microsoft Academic Search

The development of the concept of pH from its invention by Sorenson in 1909 to the present-day National Bureau of Standards' pH scale is reviewed. The liquid junction potential problem involved in the use of the pH meter is discussed in detail. The magnitude of the error due to the junction potential depends upon the pH, ionic strength, nature of

Isaac Feldman

1956-01-01

335

Acidogenesis of dairy wastewater at various pH levels  

Microsoft Academic Search

Continuous experiments were conducted to study the influence of pH in the range 4.0-6.5 on the acidification of dairy wastewater at 37°C with 12 hours of hydraulic retention in an upflow reactor. Results showed that degradation of dairy pollutants increased with pH from pH 4.0 to 5.5. At pH 5.5, 95% of carbohydrate, 82% of protein and 41% of lipid

H.-Q. Yu; H. H. P. Fang

2002-01-01

336

Effect of lansoprazole on intragastric pH  

Microsoft Academic Search

Lansoprazole is a newly developed proton pump inhibitor. The purpose of this study was to determine whether morning or evening dosage gave better control of 24-hr intragastric pH. In this study, we examined the antisecretory effect of lansoprazole by repeated intragastric pH monitoring on four occasions in eight normal subjects and compared median 24-hr pH values and pH threshold time

Michio Hongo; Shuichi Ohara; Yorihisa Hirasawa; Shinichiro Abe; Shigeru Asaki; Takayoshi Toyota

1992-01-01

337

New Routes to the PhD: Cause for Concern?  

ERIC Educational Resources Information Center

|Recent developments suggest that the PhD is at a turning point. Professional groups have criticised the so-called traditional PhD. New routes to the PhD are proposed by several bodies and endorsed by one funding council. In light of these developments, it is appropriate to ask what the implications are for the PhD and for the academy. A focus…

Johnston, Bill; Murray, Rowena

2004-01-01

338

Investigating pH of common household substances  

NSDL National Science Digital Library

This activity is a classroom lab where students test common household liquids for pH level on the pH continuum, 1-14. They compare and contrast everyday use of the liquids, and how this relates to the liquids' pH property.

339

21 CFR 876.1400 - Stomach pH electrode.  

Code of Federal Regulations, 2010 CFR

...2009-04-01 2009-04-01 false Stomach pH electrode. 876.1400 Section 876.1400... Diagnostic Devices Ā§ 876.1400 Stomach pH electrode. (a) Identification. A stomach pH electrode is a device used to measure...

2009-04-01

340

21 CFR 876.1400 - Stomach pH electrode.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 2013-04-01 false Stomach pH electrode. 876.1400 Section 876.1400... Diagnostic Devices Ā§ 876.1400 Stomach pH electrode. (a) Identification. A stomach pH electrode is a device used to measure...

2013-04-01

341

Notes on the Measurement of pH Values.  

National Technical Information Service (NTIS)

The original definition of pH is: pH = -log a(sub H). Where a(sub H) is the (relative) hydrogen ion activity. However, a single ion activity cannot be measured. Activities of individual ionic species are necessarily conventional. The pH number, of course,...

R. M. Carranza R. B. Rebak

2005-01-01

342

Measurement of pH in high ionic strength solutions  

DOEpatents

A practical method is described for measuring pH in solutions of high ionic strength (e.g., brines, process solutions). The pH is determined by integratively measuring the potential due to H{sup +} and the potential due to another cation or anion and relating the combined electrical potential to a calculated pH for high ionic strength solutions.

Knauss, K.G.; Wolery, T.J.; Jackson, K.J.

1991-12-31

343

pH dynamics in sewers and its modeling.  

PubMed

pH variation in sewers has a significant effect on hydrogen sulfide production and emissions, and hence its accurate prediction is critical for the optimization of mitigation strategies. In this study, the nature and dynamics of pH variation in a sewer system is examined. Three sewer systems collecting domestic wastewater were monitored, with pH in all cases showing large diurnal variations. pH in fresh sewage in all three cases had a very similar trend with maximum pH in the range of 8.5-8.7. pH variation in fresh sewage followed the same pattern as the sewage flow rate, suggesting that sewage pH is influenced by household water use. Nitrogen content of the wastewater was found to be the most influential factor causing pH variation in fresh sewage, with the total ammonium concentration variation well correlated with the pH variation. A methodology for predicting pH variation in sewers is developed and calibration protocols proposed. The methodology, which is based on the concept of charge balance, was validated using titration curves and field pH data. Measurement of the total ammonium concentration in fresh sewage was found necessary and adequate for the calibration of the charge balance-based pH model. PMID:23962970

Sharma, Keshab; Ganigue, Ramon; Yuan, Zhiguo

2013-08-02

344

A Multiattributes Approach for Ranking PhD Programs  

ERIC Educational Resources Information Center

|In its plan to combat the PhD shortage crisis, the Association to Advance Collegiate Schools of Business International (AACSB; 2003) has called for the development of PhD program rankings to serve as incentives for academic institutions to invest more in PhD programs, thereby counterbalancing the disproportionate influence of master of business…

Urbancic, Frank R.

2008-01-01

345

INFLUENCE OF PH AND REDOX CONDITIONS ON COPPER LEACHING  

EPA Science Inventory

Leaching behavior of metals from a mineral processing waste at varying pH and redox conditions was studies. Effect of combinations of pH and Eh on leaching of copper is described. Leaching of copper was found to be dependent on both pH and Eh. Higher concentrations of Cu were ...

346

Ian Douglass Coulter, PhD  

PubMed Central

This paper focuses on Dr. Ian Coulter’s accomplishments from the time he became Executive Vice-President of CMCC in 1981, until he ended his presidency with a year’s administrative leave in 1990. Annual planning initiatives, pedagogy, scholarship, conflicts, and the quest for university affiliation are discussed as well as his legacy to the College and the chiropractic profession. The term “adventurous” was first attributed to Coulter by Oswald Hall, PhD, Professor Emeritus, University of Toronto who had worked closely with Coulter in a major investigation of the chiropractic profession from 1976 to 1979. Throughout this article the author tries to capture the spirit of daring, innovation and intellect that permeated Coulter’s presidency, enthralling his advocates and confounding his detractors.

Brown, Douglas M

2004-01-01

347

Global transcription profiles and intracellular pH regulation measured in Bacillus licheniformis upon external pH upshifts  

Microsoft Academic Search

For optimization of propagation conditions for an industrially used Bacillus licheniformis, this study examines the effect of transferring cells at the early-stationary growth phase (pH 5.3) to fresh growth medium at pH 5.0–8.0. Intracellular pH (pH i) was measured on a single-cell level, using fluorescence ratio imaging microscopy after staining with 5(6)-carboxyfluorescein diacetate succinimidyl ester. Transcription profiles were determined using a genome

Tina Hornbęk; Mogens Jakobsen; Jens Dynesen; Allan K. Nielsen

2004-01-01

348

Predicting Soil pH and Buffer pH In Situ with a Real-Time Sensor  

Microsoft Academic Search

Measuring soil pH is an important step in assessing the chemical status of a soil and in remediating high and low soil pH situations. Soil pH measurements on a spatial scale are limited by labor and lab analysis costs. A pH sensor mounted on a mobile sensing platform may be able to reduce these costs while providing a high-resolution soil

S. A. Staggenborg; M. Carignano; L. Haag

2007-01-01

349

PhD Students' Work Conditions and Study Environment in University- and Industry-Based PhD Programmes  

ERIC Educational Resources Information Center

|During the last 10 years, new models of funding and training PhD students have been established in Denmark in order to integrate industry into the entire PhD education. Several programmes have been conducted where it is possible to co-finance PhD scholarships or to become an employee as an industrial PhD in a company. An important question is…

Kolmos, A.; Kofoed, L. B.; Du, X. Y.

2008-01-01

350

pH distributions in spontaneous and isotransplanted rat tumours.  

PubMed Central

Spontaneous mammary tumours of the rat with various degrees of malignancy exhibit similar tissue pH distributions. The mean pH (+/- s.d.) of dysplasia is 7.05 +/- 0.20. In benign tumours the mean pH is 6.95 +/- 0.19 and in malignant tumours it is 6.94 +/- 0.19. In contrast, tumours with the same degree of malignancy but different histologies show different pH distributions. Benign tumours with a higher percentage of fibrous tissue exhibit less acidic pH values than those with larger portions of epithelial cells (delta pH = 0.38 pH units). The pH distribution in the benign tumours is independent of the tumour wet weight up to stages of very advanced growth. In the malignant tumours, a trend towards more acidic pH values is observed as the tumour mass enlarges. However, in tissue areas within a malignant tumour with gross, long-established necrosis the pH distribution is shifted towards more alkaline pH values. The pH distributions in spontaneous rat tumours are not significantly different from those obtained in isotransplanted Yoshida sarcomas (6.87 +/- 0.21). In the Yoshida sarcomas, mean pH values do not correlate with tumour size. However, a pH gradient from the rim to the centre of the tumours is found which coincides with the development of small, disseminated necroses in the tumour centre. It is concluded that pathology-related variations of tumour pH may be more important than the mode of tumour origin or the degree of malignancy.

Kallinowski, F.; Vaupel, P.

1988-01-01

351

Bridging the Reef gaps: first evidence for corals surviving under low pH conditions  

NASA Astrophysics Data System (ADS)

Following two major extinction events, the late Permian and Triassic/Jurassic, there is a long absence of corals from the geological record followed by a recurrence coral fossils. This unusual disappearance and reappearance, referred to commonly as 'reef gaps', was explained as a failure in sampling effort, and/or the movement of these species into geographic 'refugia' that have not been found. Because the phylogeny of recent corals suggests their origin in the pre-Permian-extinction , an alternative explanation for reef gaps hypothesized that corals have a means of alternating between soft bodies and fossilizing forms. This study supports this hypothesis. Thirty coral fragments from 5 coral colonies of the scleractinian Mediterranean corals Oculina patagonica (encrusting) and Madracis pharencis (bulbous) were subjected to pH 7.4-7.6 (in accordance with the pH projected by the IPCC for the year 2300) and 30 fragments to pH 8.0-8.3 (ambient) over a period of 12 months. 100% of the colonies in the experiment and 90% of all polyps survived to the end the experiment. The corals grown in acidified conditions, where skeleton-building conditions were absent, maintained basic life functions as a solitary skeleton-less ecophenotype resembling a sea anemone. On an evolutionary scale, these results provide a possible explanation to coral survival over major extinction events such as the Permian/Triassic and Triassic/Jurassic events. It is important to note that these results only demonstrate that corals can persist as soft bodied ecophoenotypes, but the loss of reef framework has major ramifications to the entire structure and function of coral reef ecosystems, ultimately impacting the services they provide to human society.

Tchernov, D.; Fine, M.

2007-12-01

352

Enhanced solution strategies for the ultimate strength analysis of composite steel–concrete sections subject to axial force and biaxial bending  

Microsoft Academic Search

We present a family of algorithms for evaluating the ultimate limit state of composite and reinforced concrete (RC) sections of arbitrary polygonal or circular shape, either simple or multicell, subject to axial force and biaxial bending. All algorithms are based upon a secant strategy for computing the stiffness matrix used in the equilibrium iterations while they differ in the scheme

Luciano Rosati; Francesco Marmo; Roberto Serpieri

2008-01-01

353

An Experimental Study on the Ultimate Strength of the Adventitia and Media of Human Atherosclerotic Carotid Arteries in Circumferential and Axial Directions  

PubMed Central

Atherosclerotic plaque may rupture without warning causing heart attack or stroke. Knowledge of the ultimate strength of human atherosclerotic tissues is essential for understanding the rupture mechanism and predicting cardiovascular events. Despite its great importance, experimental data on ultimate strength of human atherosclerotic carotid artery remains very sparse. This study determined the uniaxial tensile strength of human carotid artery sections containing type II and III lesions (AHA classifications). Axial and circumferential oriented adventitia, media and intact specimens (total=73) were prepared from 6 arteries. The ultimate strength in uniaxial tension was taken as the peak stress recorded when the specimen showed the first evidence of failure and the extensibility was taken as the stretch ratio at failure. The mean adventitia strength values calculated using the 1st Piola-Kirchoff stress were 1996±867kPa and 1802±703kPa in the axial and circumferential directions respectively, while the corresponding values for the media sections were 519±270kPa and 1230±533kPa. The intact specimens showed ultimate strengths similar to media in circumferential direction but were twice as strong as the media in the axial direction. Results also indicated that adventitia, media and intact specimens exhibited similar extensibility at failure, in both the axial and circumferential directions (stretch ratio 1.50 +/?0.22). These measurements of the material strength limits for human atherosclerotic carotid arteries could be useful in improving computational models that assess plaque vulnerability.

Teng, Zhongzhao; Tang, Dalin; Zheng, Jie; Woodard, Pamela K.; Hoffman, Allen H.

2009-01-01

354

Assessing and Forecasting, by Play, Natural Gas Ultimate Recovery Growth and Quantifying the Role Technology Advancements in the Texas Gulf Coast Basin and East Texas.  

National Technical Information Service (NTIS)

A detailed natural gas ultimate recovery growth (URG) analysis of the Texas Gulf Coast Basin and East Texas has been undertaken. The key to such analysis was determined to be the disaggregation of the resource base to the play level. A play is defined as ...

W. L. Fisher E. M. Kim

2000-01-01

355

Elastic buckling characteristics of two-way grid shells of single layer and its application in design to evaluate the non-linear behavior and ultimate strength  

Microsoft Academic Search

The present paper investigates and discusses both of the linear and elastic buckling characteristics of two-way grid shells of single layer under gravity loads focusing on the nonlinear behavior due to geometric imperfection. It is followed by a proposal of the estimation method usable in design to evaluate the nonlinear behavior and the ultimate strength of the shells based on

Tetsuo Yamashita; Shiro Kato

2001-01-01

356

"Our Ultimate Competition," a Speech by John Neufeld, and Readers' Responses to Neufeld's "Boys Lie" by Matthew Ellis, Jaime Miller and Liz Ackert.  

ERIC Educational Resources Information Center

Suggests the ultimate competition for writers of contemporary adolescent fiction is life--the world that children inhabit is getting stranger and stranger. Discusses parents' and adolescents' different reactions to the novel "Boys Lie," which addresses the issues of rape and sexual harassment. Presents reactions to the speech and the responses of…

Moore, John Noell, Ed.

2000-01-01

357

Managing in a federal system without an ‘ultimate arbiter’: Kompetenz-Kompetenz in the EU and the ante-bellum United States  

Microsoft Academic Search

Although an ‘ultimate arbiter’ is generally accepted as a necessary element of a federation, emerging federal systems are often unable to agree on who should play the role. Legally, the debate surrounds the right to monitor the limits of federal and state competences – or the right to Kompetenz-Kompetenz. This article looks at how the early United States and the

Erin Delaney

2005-01-01

358

[Modification of urinary pH through ascorbic acid].  

PubMed

The influence of orally administered ascorbic acid on the urinary pH of 10 healthy volunteers and 10 patients with infected urine was investigated. During a four-day period of investigation urinary pH and the concentration of ascorbic acid in the respective urines were measured five times a day. On the second and third day three times a dose of 2 g ascorbic acid was given, while the diet was under control all four days. A correlation between pH decrease and ascorbic acid concentration is only observed if the concentration of the latter is higher than 200 mg%. The mean decrease in urinary pH between days with ascorbic acid supply and days without is -0,16 pH units for the volunteers respectively -0,18 pH units for the patients. Therefore, vitamin C can not be recommended to lower the pH of alkaline urines. PMID:7287481

Bannwart, C; Hagmaier, V; Straumann, E; Hofer, H; Vuillemier, J P; Rutishauser, G

1981-08-01

359

Tear pH, air pollution, and contact lenses  

SciTech Connect

We analyzed the tear pH of a random sample of 100 subjects, divided into 3 groups according to the stability of their precorneal tear film (normal eyes, borderline; and dry eyes). The average pH value obtained was 7.52. The pH for borderline and dry eyes was higher than for normal eyes. The purpose of this study was to determine the influence of air pollution, specifically sulfur dioxide (SO/sub 2/), on the tear pH. We found that air pollution affected the lacrimal pH, which decreased when the atmospheric SO/sub 2/ increased. Finally, we studied the effect of soft contact lens wear on tear pH after 7 days of contact lens adaptation by assessing the tear pH decrease. We took into account the influence of the sex and age of subjects on the results obtained.

Andres, S.; Garcia, M.L.; Espina, M.; Valero, J.; Valls, O.

1988-08-01

360

Single quintuple bond [PhCrCrPh] molecule as a possible molecular switch  

NASA Astrophysics Data System (ADS)

The electronic transport properties of a single quintuple bond [PhCrCrPh] molecule sandwiched between two Au(111) surfaces with the trans-bent and linear configurations are studied by a fully self-consistent nonequilibrium Green's function method combined with density functional theory. The calculated transmission spectra of two chemical isomers are remarkablty distinctive. Theoretical results suggest that the current through the trans-bent configuration is significantly larger than the corresponding linear one. The predicted on-off ratio of currents ranging from around 50 to 200 in the applied bias window [-1.5 V, 1.5 V] suggests that multiple bond compounds have attractive potential in molecular switch technology.

Huang, Jing; Li, Qunxiang; Ren, Hao; Su, Haibin; Yang, Jinlong

2006-11-01

361

To PhET or Not To PhET: That Is the Question  

NASA Astrophysics Data System (ADS)

The investigation examined use of a Physics Education Technology (PhET) simulation versus a hands-on lab activity on student's conceptual understanding of physics content. Topics of study included vectors, projectile motion, direct current (DC) circuits, and the photoelectric effect. Participants consisted of high school juniors and seniors enrolled in a physics course. Assessment instruments consisted of questions taken from the Vector Evaluation Test, the Electric Circuits Concept Evaluation test, textbook test banks, or written to address concepts under evaluation. Data collection consisted of a pre-test score, a post-test score, and a gain score. The conceptual understanding of the experimental and the control groups did not significantly differ for vectors and DC circuits. The conceptual understanding of the experimental and control groups did significantly differ for projectile motion. The results indicated a conceptual gain for students using the photoelectric effect simulation. Student attitudes towards the PhET simulations were positive.

Casao, Robert

2008-10-01

362

PhET Simulation: Alpha Decay  

NSDL National Science Digital Library

This resource simulates the process of alpha decay, a type of radioactive decay in which an atomic nucleus emits an alpha particle. A number of different radioisotopes will undergo this type of decay; this web page simulates the Polonium-211 atom. Users can watch a single atom decay or work with a "Bucket O' Polonium" to view a pattern of decay. Editor's Note: Radioactive decay happens when an atomic nucleus of an unstable atom loses energy by emitting ionizing radiation. If you take a sample of a particular radionuclide, the half-life is the time it takes for half the atoms to decay. The Bucket O' Polomium" activity could be invaluable to help students understand the concept of half-life. They can observe 100 virtual polonium-211 atoms in the process of decay. Pause the action every 1/2 second to get a feel for the math associated with radioactive decay. Simple enough for grades 7-8, but can be adapted for AP Physics as well. See Related Materials for a link to a student guide specifically developed by the PhET team for use with this simulation.

2011-07-21

363

Low pH alkaline chemical formulations  

SciTech Connect

This report describes the development of a surfactant-enhanced alkaline flooding system that is applicable to specific reservoir conditions in Wilmington (California) field. The cost of the chemicals for an ASP (alkali/surfactant/polymer) flood is calculated to be $3.90/bbl of oil produced, with 78% of that cost attributable to polymer. This research included phase behavior tests, oil displacement tests, mineral dissolution tests, and adsorption measurements. It was discovered that consumption of low pH alkalis is low enough in the Wilmington field to be acceptable. In addition, alkali dramatically reduced surfactant adsorption and precipitation. A mixture of NaHCO3 and Na2CO3 was recommended for use as a preflush and in the ASP formulation. Research was also conducted on the synergistic effect that occurs when a mixture of alkali and synthetic surfactant contacts crude oil. It appears that very low IFT is predominantly a result of the activation of the natural surfactants present in the Wilmington oil, and the sustained low IFT is primarily the result of the synthetic surfactant. It also appears that removal of acids from the crude oil by the alkali renders the oil more interfacially reactive to synthetic surfactant. These phenomena help to explain the synergism that results from combining alkali and synthetic surfactant into a single oil recovery formulation. 19 refs., 24 figs., 10 tabs.

French, T.R.; Peru, D.A.; Thornton, S.D.

1989-01-01

364

PH sensors based on iridium oxide  

SciTech Connect

Iridium oxide shows considerable promise as a high temperature pH sensing material. It is being currently considered for measurement of hot geological brines in connection with nuclear waste disposal. The use of a sputtered thin film of iridium oxide may also lead to much smaller and less costly ionic sensor than those based on the glass electrode. The authors report on recent research which has concentrated on evaluating the long time stability and repeatability of the sputtered electrodes and developing an understanding of the hydroxylation of the oxide. The interaction of IrO/sub 2/ with water apparently affects its formal potential as an electrode. The understanding of this interaction may also help develop a determination of the mechanism for its Nernstian behavior. The electrochemical behavior and surface analysis of IrO/sub 2/ is, however, limited by the cleanliness of the surface and particular effort has been focussed on this problem. They investigate methods for producing both clear, hydroxyl-free and model, hydroxylated IrO/sub 2/ surfaces.

Tarlov, M.J.; Huang, P.H.; Kreider, K.G. (Center for Chemical Technology, National Institute of Standards and Technology, Gaithersburg, MD (US))

1988-01-01

365

Soil pH Variation Within a Soil. III. pH Variation in Limed Soil  

Microsoft Academic Search

There are many methods for determining lime requirement, but no single method is suitable for all soils. A fast and efficient method to evaluate lime effect is needed. Soil buffering capacity tests and column-leaching tests were applied to the limed Van Rockel soil at the depth of 0–30 cm to evaluate pH distribution after liming. Two groups of the Van Rockel

Shih-Lin Hsu; Joe Hung; Arthur Wallace

2004-01-01

366

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

367

pH measurement of low-conductivity waters  

USGS Publications Warehouse

pH is an important and commonly measured parameter of precipitation and other natural waters. The various sources of errors in pH measurement were analyzed and procedures for improving the accuracy and precision of pH measurements in natural waters with conductivities of < 100 uS/cm at 25 C are suggested. Detailed procedures are given for the preparation of dilute sulfuric acid standards to evaluate the performance of pH electrodes in low conductivity waters. A daily check of the pH of dilute sulfuric acid standards and deionized water saturated with a gas mixture of low carbon dioxide at partial pressure (air) prior to the measurement of the pH of low conductivity waters is suggested. (Author 's abstract)

Busenberg, Eurybiades; Plummer, L. N.

1987-01-01

368

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

369

A novel paper pH sensor based on polypyrrole  

Microsoft Academic Search

A novel versatile paper pH sensor has been fabricated from conducting polypyrrole (PPy) supported on a paper substrate. The response of this paper pH sensor is based on the conductivity change of PPy under different pH environments, which is monitored by measuring the resistance of the sensor under dry conditions via a specially designed four-point probe connected to a multimeter.

Fang Yue; Tan Swee Ngin; Ge Hailin

1996-01-01

370

Notes on the Measurement of pH Values  

Microsoft Academic Search

The original definition of pH is: pH = -log a{sub H}. Where a{sub H} is the (relative) hydrogen ion activity. However, a single ion activity cannot be measured. Activities of individual ionic species are necessarily conventional. The pH number, of course, has in itself little absolute significance. As the negative of the logarithm of a product of a concentration (c

R M Carranza; R B Rebak

2005-01-01

371

Primary state standard for the pH unit  

Microsoft Academic Search

wide utilization of pH measurements started with the application of the glass electrode whose theory was established by Academician B. P. Nikol'skii in 1937. The first instruments with a glass electrode, the pH meters, appeared in the USSR at the end of the fifties. At present more than 100,000 such instruments have been produced. The wide application of pH measurements

M. Yu. Gorina; D. K. Kollerov; L. P. Piskunova

1975-01-01

372

pH sensors based on hydrogenated diamond surfaces  

Microsoft Academic Search

We report on the operation of ungated surface conductive diamond devices in electrolytic solutions. The effect of electrolyte pH on the channel conductivity is studied in detail. It is shown that fully hydrogen terminated diamond surfaces are not pH sensitive. However, a pronounced pH sensitivity arises after a mild surface oxidation by ozone. We propose that charged ions from the

Jose A. Garrido; Stefan Kuch; Martin Stutzmann; Oliver A. Williams; R. B. Jackmann

2005-01-01

373

Effect of pH on phosphorylation of sago starch  

Microsoft Academic Search

Sago starch, in a semidry state was phosphorylated with 2% sodium trimetaphosphate (STMP), 5% sodium tripolyphosphate (STPP) singly, and in combination at pH levels between 6 and 11. As the reaction pH was increased from 6 to 11, the degree of phosphorylation was observed to decrease from 0.186 to 0.083% P with STPP, except at pH 9 where the degree

K Muhammad; F Hussin; Y. C Man; H. M Ghazali; J. F Kennedy

2000-01-01

374

pH electrode based on ALD deposited iridium oxide  

Microsoft Academic Search

We have made planar pH electrodes that use iridium oxide (IrOx) fabricated by atomic layer deposition (ALD) as the pH sensitive layer. As far as we know, ALD has not been reported earlier as the method of producing IrOx layer on pH electrodes. The structure built on glass substrate consists of 300 nm thick titanium electrodes coated with 110 nm

Tomi Ryynįnen; Kirsi Nurminen; Jani Hämäläinen; Markku Leskelä; Jukka Lekkala

2010-01-01

375

Surface pH measurements during nickel electrodeposition  

Microsoft Academic Search

To better understand the electrochemistry of nickel electrowinning from nickel chloride solutions at the cathode-electrolyte interface, the cathode surface pH was measured using a flat-bottom combination glass pH electrode and a 500 mesh nickel-plated gold gauze as cathode. The cell was a modification of that designed by Romankiw and coworkers. The pH electrode was positioned at the back of, and

J. Ji; D. B. Dreisinger; E. Peters

1995-01-01

376

Ambulatory Esophageal pH Monitoring: New Directions  

Microsoft Academic Search

pH testing remains a commonly used evaluative tool in clinical practice. However, the original tool that included a nasally placed pH catheter was plagued with a variety of shortcomings, primarily the effect of the procedure on patients’ lifestyle and thus on reflux-provoking activities. The miniaturization of evaluative techniques in gastroenterology was the impetus for the development of the wireless pH

Ram Dickman; Ronnie Fass

2006-01-01

377

Q(?) learning technique for pH control  

Microsoft Academic Search

A simple learning control approach for controlling a pH neutralization process has been developed in this paper. A one-step-ahead Q-learning, namely Q(?)-learning, using a lookup table is developed and applied to a pH process: weak base - strong acid process. The objective of the controller is to maintain the pH within the goal state. The application at a laboratory pilot

S. Syafiie; F. Tadeo; E. Martinez

2009-01-01

378

ISFET pH sensor characterization: towards biosensor microchip application  

Microsoft Academic Search

The ion-sensitive field effect transistor (ISFET) based pH sensor has the advantages of smaller size, fast response time and fabrication compatible with standard MOS technology. Beside that, the functionality of pH ISFETs is various especially in biomedical areas. In the design and characterization of an ISFET pH sensor, the ISFET model was characterized and a final design has been evolved

Rozina Abdul Rani; Othman Sidek

2004-01-01

379

Decrease in Daphnia egg viability at elevated pH  

Microsoft Academic Search

The effect of high pH on the reproduction of two Daphnia galeata clones was experimentally investigated in the laboratory. We observed that the mortality of juveniles and adults did not increase with increasing pH in the range pH 9.0- 10.5, which agrees with what is generally reported in the literature for cladoceran zooplankton and suggests that the threshold value for

J. Vijverberg; Kalf F. D; M. Boersma

1996-01-01

380

Soil pH and species diversity in coastal dunes  

Microsoft Academic Search

Soil pH was measured at two different spatial scales in coastal dunes on Norderney, North Sea, and in Mecklenburg-Vorpommern, Baltic Sea, Germany. Relationships between the variability in soil pH, species richness and species diversity are presented. Species richness and diversity were highest in grey dunes, where soil pH was at intermediate levels; both variables were lower in yellow and brown

M. Isermann

2005-01-01

381

Photoreactions of bacteriorhodopsin at acid pH  

Microsoft Academic Search

It has been known that bacteriorhodopsin, the retinal protein in purple membrane which functions as a light-driven proton pump, undergoes reversible spectroscopic changes at acid pH. The absorption spectra of various bacteriorhodopsin species were estimated from measured spectra of the mixtures that form at low pH, in the presence of sulfate and chloride. The dependency of these on pH and

G. Varo; J. K. Lanyi

1989-01-01

382

PHYSICAL EFFECTS OCCURRING DURING GENERATION AND AMPLIFICATION OF LASER RADIATION: Ultimate values of the gain of solid-state rod amplifiers operating under inversion storage conditions  

NASA Astrophysics Data System (ADS)

A numerical calculation is reported of an inversion conservation coefficient of cylindrical rod solid-state amplifiers with the active element diameter from 1.5 to 15 cm operated under continuous pumping conditions. It is shown that the ultimate gain, limited only by superluminescence, exceeds considerably the value usually obtained in experiments. Various methods of eliminating parasitic effects, which limit the gain of real amplifiers, are considered. The degree of influence of these effects on the inversion conservation coefficient is discussed. The results are given of an experimental determination of the gain close to the ultimate value (0.18 cm- 1 for an active element 3 cm in diameter). Calculations are reported of the angular distributions of superluminescence and parasitic modes demonstrating that the latter can be suppressed by spatial filtering.

Bayanov, V. I.; Vinokurov, G. N.; Zhulin, V. I.; Yashin, V. E.

1989-02-01

383

Ultimate emulsion and its applications: a laboratory-made silver halide emulsion of optimized quality for monochromatic pulsed and full-color holography  

NASA Astrophysics Data System (ADS)

A ultra-high sensitivity holographic Ultimate emulsion (10nm grains) has been produced, which allows the realization with short exposure times of bright, large sized, with wide view angle and full color holograms of fragile still subjects of monochromatic pulsed reflection holograms of alived subjects. The high transparency of Ultimate emulsions as color transmission holograms makes them highly suitable for mastering, the copies keeping the same performances as the master. Copies on other materials, especially polymer emulsions are possible. Coating machines have been performed for the production of 36 x 44 cm triacetate films and 60 x 84 cm glass plates under controlled conditions of temperature and humidity. Also, a homemade portable camera with pulsed YLF or ruby lasers allows to realize holograms in situ of alive subjects on H1 transmission holograms up to 60 x80 cm and instant H2 reflection copies up to 30 x 40 cm. Some examples of holograms are displayed.

Gentet, Yves; Gentet, Philippe

2000-10-01

384

pH equilibration in human erythrocyte suspensions  

Microsoft Academic Search

Summary A stopped-flow rapid reaction apparatus was used to study the rate of pH equilibration in human red cell suspensions. Flux of OH? or H+ was determined over a wide range of extracellular pH (4–11) in CO2-free erythrocyte suspensions. In these experiments, an erythrocyte suspension at pH 7.3 is rapidly mixed with an equal volume of NaCl solution at 3.0>pH>11.5.

Anne McElroy Critz; Edward D. Crandall

1980-01-01

385

Molecular aspects of bacterial pH sensing and homeostasis  

PubMed Central

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 whose pH is below 3 or above 11. Here we describe how recent insights into the structure and function of key molecules and their regulators reveal novel strategies of bacterial pH-homeostasis. These insights may help us better target certain pathogens and better harness the capacities of environmental bacteria.

Krulwich, Terry A.; Sachs, George; Padan, Etana

2011-01-01

386

Nanosensor aided photoacoustic measurement of pH in vivo  

NASA Astrophysics Data System (ADS)

pH plays a critical role in many aspects of cell and tissues physiology. Lower pH is also a typical characteristic of arthritic joints and tumor tissues. These pH anomalies are also exploited in different drug delivery mechanisms. Here we present, a new method of pH sensing in vivo using spectroscopic photoacoustic measurements facilitated by pH sensitive nanosensors. The nanosensors consist of Seminaphtharhodafluor (SNARF), a pH sensitive dye, encapsulated in a specially designed polyacrylamide hydrogel matrix with a hydrophobic core. The photoacoustic intensity ratio between the excitation wavelengths of 585nm and 565nm increases in the pH range from 6.0 to 8.0 and is used to determine the pH of the local environment. These nanosensors are biodegradable, biocompatible, have a long plasma lifetime and can be targeted to any type of cells or tissues by surface modification using proper targeting moieties. The encapsulation of the dye prevents the interaction of the dye with proteins in plasma and also reduces the dye degradation. The SNARF dye in its free form loses 90% of its absorbance in presence of albumin, a protein found in abundance in plasma, and this has severely limited its adaptation to in vivo environments. In comparison, the SNARF nanosensors lose only 16% of their absorbance in the same environment. We employ these nanosensors to demonstrate the feasibility of pH sensing in vivo through photoacoustic measurements on a rat joint model.

Ray, Aniruddha; Yoon, Hyung Ki; Kopelman, Raoul; Wang, Xueding

2013-03-01

387

Aerosol pH in the marine boundary layer  

Microsoft Academic Search

Impacts of sea-salt-aerosol pH on oxidation processes, sulfur cycling, and surface-ocean fertilization are uncertain; estimates vary from pH9 and the pH-dependence of some transformations is poorly characterized. We modeled these processes under clean and polluted conditions. At pH 8, S(IV)+O3 in sea salt is the principal S-oxidation pathway. At pH 5.5, S(IV) oxidation by HOCl dominates. Decreased SO2 solubility at

William C Keene; Rolf Sander; Alexander A. P Pszenny; Rainer Vogt; Paul J Crutzen; James N Galloway

1998-01-01

388

Effect of cooling rate on dendrite arm spacing (DAS), eutectic cell count (ECC) and ultimate tensile strength (UTS) of austempered chilled ductile iron  

Microsoft Academic Search

This paper presents the results obtained and the deductions made from a series of microstructural studies and strength tests involving austempered chilled ductile iron which was sand cast using a variety of end chills (metallic, non-metallic, water-cooled and sub-zero, respectively). The effect of cooling rate on the dendrite arm spacing, eutectic cell count and the ultimate tensile strength were evaluated.

Joel Hemanth

1999-01-01

389

Simultaneous monitoring of gastric and oesophageal pH reveals limitations of conventional oesophageal pH monitoring in milk fed infants  

Microsoft Academic Search

BACKGROUNDMonitoring oesophageal pH conventionally detects “acid reflux” (pH less than 4). The pH of the gastric contents determines whether or not reflux can be detected.AIMTo monitor gastric and oesophageal pH simultaneously in order to determine the effect of milk feeds on gastric pH and how this would influence interpretation of the oesophageal pH record.METHODSMilk fed infants for whom oesophageal pH

D J Mitchell; B G McClure; T R J Tubman

2001-01-01

390

Derangement of pH Homeostasis in the Renal Papilla: Ochratoxin A Increases pH in Vasa recta Blood  

Microsoft Academic Search

It is reported that ochratoxin A (OTA) impairs urinary acidification by increasing the urinary pH and also increases the intracellular pH in Madin-Darby canine kidney cells. This study was designed to examine whether OTA deranges pH homeostasis in the interstitium (or vasa recta) of the renal papilla. Rats were injected once with OTA (3 ?mol\\/kg body weight) intravenously (acute application)

Gen Kuramochi; Michael Gekle; Stefan Silbernagl

1997-01-01

391

Biomedical PhD education--an international perspective.  

PubMed

The PhD, otherwise known as the doctor of philosophy or Dr. Phil., is an internationally recognized degree, indicating that the PhD graduate has received training in research under supervision. Traditionally, the PhD was the route to an academic career, with most successful PhD graduates receiving tenured university positions. However, over the past 20-30 years, and particularly the past 10 years, the situation has changed dramatically. Governments in many countries have invested massively in PhD education, believing that trained researchers will contribute to the 'knowledge society', and thus increase the competitiveness of their countries in the future economies of the world. Thus, only a small fraction of PhD graduates now end up in academic research. Yet, the PhD remains a research degree, and indeed, institutions have become heavily dependent on PhD students for their research output. The situation has thus created a paradox. On the one hand, it has become essential for institutions to have many PhD students and for the research performed to be of the highest level. On the other hand, the careers of PhD students are not necessarily going to be directly related to the research performed during their PhD studies. The purpose of this article is to explore how this seeming paradox is being addressed in biomedicine and to show that far from being inconsistent that the two aspects are in fact complementary. The article is based on the author's experience as Head of Aarhus Graduate School of Health Sciences 2002-2011 and his work with graduate schools across Europe and internationally through the organization ORPHEUS. PMID:23461869

Mulvany, Michael J

2013-04-06

392

Notes on the Measurement of pH Values  

SciTech Connect

The original definition of pH is: pH = -log a{sub H}. Where a{sub H} is the (relative) hydrogen ion activity. However, a single ion activity cannot be measured. Activities of individual ionic species are necessarily conventional. The pH number, of course, has in itself little absolute significance. As the negative of the logarithm of a product of a concentration (c or m) and an activity coefficient (y or {gamma}), it acquires its magnitude from the numerical scale adopted for the latter. Experimental pH measurements are nonetheless widely applied to the determination of thermodynamic equilibrium data such as pK values, on the assumption that they represent -log a{sub H} (or paH). The single ion activity coefficient approaches unity as the ionic strength goes to zero, so that activity becomes m or c and paH becomes pmH or pcH. pH is therefore defined operationally in terms of the operation or method used to measure it, that is, by means of a cell called an operational cell. The cell is standardized by solutions of assigned pH value (Reference Value pH Standard, Primary pH Standards and Operational Standards). Such standard reference solutions are buffer solutions whose pH values are assigned from measurements on cells with or without liquid junction. It must be emphasized that the definition of pH scale is quite different from the measurement of pH with glass-reference electrode-pH meter assemblies, where several standards are used in order to take into account possible deficiencies in the electrode and meter performance.

Carranza, R M; Rebak, R B

2005-05-05

393

Effect of initial pH independent of operational pH on hydrogen fermentation of food waste.  

PubMed

The effect of initial pH from 5.0 to 9.0 on H2 fermentation of food waste was investigated. In this batch experiment, however, unlike previous studies for initial pH, operational pH was maintained at 5.0 by the addition of alkaline solution. Although the period for pH drop from the initial values to 5.0 was less than one-tenth of the entire fermentation, this short period significantly affected the H2 production performance. At initial pH 6.0-9.0, successful H2 yield of 1.3-1.9 mol H2/mol hexose(added) was achieved with a peak value at pH 8.0. The H2 yield achieved at initial pH 8.0 was corresponded to the 8.13% of total energy content in the substrate. At initial pH 5.0, the smallest butyrate production, but the highest ethanol production was detected, indicating unfavorable conditions for H2 production. There was no significant relationship between total required amount of alkaline solution and initial pH values. PMID:21481587

Kim, Dong-Hoon; Kim, Sang-Hyoun; Jung, Kyung-Won; Kim, Mi-Sun; Shin, Hang-Sik

2011-03-22

394

Effects of low environmental pH on blood pH and sodium balance of brook trout. [Brook  

Microsoft Academic Search

Brook trout (Salvelinus fontinales) exposed to a low environmental pH (3.0-3.3) showed a drop in mean blood pH from 7.39 to 6.97. Trout at an environmental pH of 3.5 lost 50% of their total body sodium. Control sodium influx (72.5 micromols\\/100 g hours) decreased to zero between pH 3.0 and 4.9 as Na efflux increased markedly over control levels. There

Randall K. Packer; William A. Dunson

1970-01-01

395

Dynamic Theory of Die Swell for Entangled Polymeric Liquids in Tube Extrusions: New Set of Equations for the Growth and Ultimate Extrudate Swelling Ratios under the Free States  

NASA Astrophysics Data System (ADS)

A new dynamic theory of die swell for entangled polymeric liquids in a steady simple shear flow is proposed which can be used to predict the correlation of the time-dependent and time-independent extrudate swelling behaviors to the molecular parameters of polymers and the operational variables. The theory is based on the O-W-F constitutive equation and the free recovery from Poioeuille flow with different ratios. Experiments show that the magnitudes of the simple shear in the steady simple shear flow may be resolved into the free recoil resulting from the recoverable elastic strains and the viscous heating resulting from the unrecoverable viscoelastic strains. For distinguishing the recoil from the viscous heating, a partition function and two exponential fractions of conformation for the recoil and the viscous heating were defined. Thus the instantaneous, delayed and ultimate recoverable strain, and recoil in the free recovery were correlated to the partition function, the fraction of recoverable conformation, the molecular parameters, and the operational variables. Also the dynamics of the growth equation on the delayed viscoelastic strain and the delayed recoil in free state were deduced. After introducing the condition of uniform two dimensional extensions, the definition of swell ratio and the operational variables into the above correlation expressions and growth equations, then the correlations of the delayed extrudate swelling effect and the ultimate extrudate swelling effects to the molecular parameters and the operational variables were derived. Finally, two new sets of equations on the growth variables and ultimate extrudate swelling ratios under the dynamic and equilibrium states were also deduced from this dynamic theory of die swell. The first set of equations on the ultimate extrudate swelling ratio under the free and equilibrium states was verified by HDPE experimental data at two temperatures and different operational variables. The second set of equations on the growth extrudate swelling ratios under free and dynamic states was verified by PBD experimental data with different molecular weights and different operational variables. An excellent agreement is obtained, which shows that the two sets of equations for the growth and ultimate extrudate swelling ratios can be used directly to predict the correlation of extrudate swelling ratios to the molecular parameters and the operational variables.

Zhu, Chang-wei; Song, Ming-shi; Hu, Gui-xian; Wu, Da-ming; Zhao, Jing

2007-10-01

396

Enrollment of Minority Graduate Students at Ph. D. Granting Institutions.  

National Technical Information Service (NTIS)

The report is based on a survey of a sample of 288 Ph.D.-granting institutions. The Higher Education Panel sample includes 220 Ph.D.-granting institutions and usable responses were received from 154, or 70%, of the institutions. The report provides inform...

E. H. El-Khawas J. L. Kinzer

1974-01-01

397

Rethinking PhD Learning Incorporating Communities of Practice  

ERIC Educational Resources Information Center

|This paper grows from research which focuses on the learning characteristics of PhD students, incorporating communities of practice both during their studies and beyond completion of their PhD, and drawing on theories of adult learning and lifelong learning. It shows how professional discourse enhances academic discourse through student…

Shacham, Miri; Od-Cohen, Yehudit

2009-01-01

398

Photoreversible changes in pH of pea phytochrome solutions  

SciTech Connect

Phytochrome is a chromoprotein that serves as the photoreceptor for a variety of photomorphogenic responses in plants. Phytochrome was isolated from etiolated pea seedlings. Photoinduced pH changes of an unbuffered solution of the phytochrome were monitored with a semimicrocombination pH electrode at pH 6.5. Red-light irradiation increased the pH of the medium. This alkalinization was reversed by a subsequent far-red-light irradiation. The magnitude and direction of the red-light-induced pH changes was dependent on the pH of the photocrome solution, and the maximum alkalinization was observed at pH 6.0, where the number of protons taken up per phytochrome monomer was 0.18. These results suggest that phytochrome is a multifunctional protein composed of a chromophoric domain and a hydrophobic domain. It is probable that the hydrophobic domain is responsible for the photoinduced change of hydrophobicity of phytochrome and that the ionizable groups responsible for the photoinduced pH changes are localized in the chromophoric domain. (JMT)

Tokutomi, S.; Yamamoto, K.T.; Miyoshi, Y.; Furuya, M.

1982-02-01

399

Bicarbonate Increases Tumor pH and Inhibits Spontaneous Metastases  

Microsoft Academic Search

The external pH of solid tumors is acidic as a consequence of increased metabolism of glucose and poor perfusion. Acid pH has been shown to stimulate tumor cell invasion and metastasis in vitro and in cells before tail vein injection in vivo. The present study investigates whether inhibition of this tumor acidity will reduce the incidence of in vivo metastases.

Ian F. Robey; Brenda K. Baggett; Nathaniel D. Kirkpatrick; Denise J. Roe; Julie Dosescu; Bonnie F. Sloane; Arig Ibrahim Hashim; David L. Morse; Natarajan Raghunand; Robert A. Gatenby; Robert J. Gillies

2009-01-01

400

State primary standard for the pH scale  

Microsoft Academic Search

Information is given on the state primary standard for the pH scale that has been set up at VNIIFTRI. The measurement system\\u000a is described and certification results are given. The future development of pH measurement in Russia is considered.

N. N. Zdorikov; O. V. Karpov; I. I. Maksimov; E. E. Seiku

1998-01-01

401

Interlaboratory Test of pH Measurements in Rainwater.  

National Technical Information Service (NTIS)

An interlaboratory test of pH measurements in rainwater has been conducted. Various types of electrodes and junction materials were used in the test. The results of the exercise verify that there are significant differences in the pH values of low ionic s...

W. F. Koch G. Marinenko R. C. Paule

1985-01-01

402

Ph.D. Training: The End of an Era  

Microsoft Academic Search

A survey of Canadian departments of psychology showed that, in 1970, there will be more than two Ph.D. graduates in experimental fields of psychology for each new academic job that will be available. Short term projections based on these data show that Ph.D. production will continue to expand but that the academic job market will decline. It is predicted that

G. V. Goddard

1970-01-01

403

A Renaissance in Engineering PhD Education  

ERIC Educational Resources Information Center

|This paper addresses the role of engineering PhD education and its relationship to innovation and technology, and the need to reconsider how we educate PhD engineers. Much of the effort on engineering education in the last two decades focused on undergraduate education with a few exceptions that relate to master degree programs. Doctoral…

Akay, Adnan

2008-01-01

404

Regulation of Vacuolar pH in Citrus Limon.  

National Technical Information Service (NTIS)

The primary objective of this grant was to characterize the vacuolar V-ATPase of lemon fruits. Lemon fruit vacuoles have an internal pH of about 2.5. Since a typical plant vacuole has a luminal pH of around 5.5, the lemon fruit V-APTase must have special ...

2005-01-01

405

Work in progress — Creating industry ready Ph.D. graduates  

Microsoft Academic Search

The broad objective of this research is to investigate how engineering doctoral programs can better prepare graduates for careers in industry. Currently, less than 20% of engineering Ph.D. graduates work in academia. Preliminary results indicate that industry values research and leadership skills in their Ph.D. employees. Research skills can be categorized as experimental, computational or general research skills. In order

J. Watson; C. White; J. Lyons

2010-01-01

406

Putting transferable Ph.D. skills to work  

Microsoft Academic Search

The doctoral education process has typically brought about many misconceptions regarding the practicality of the Ph.D. degree. The Ph.D., by definition, requires mastery of a specific subject and expansion of the existing body of knowledge. Many professionals believe this small scope of research and contribution is far less practical for the upcoming engineer as compared to four equivalent years in

Maryclaire Peterson

2009-01-01

407

PH-Dependent Association of the Phycoerythrin Subunit.  

National Technical Information Service (NTIS)

The phycoerythrin subunit associates at pH above 9.0. The absorption spectrum of its phycoerythrobilin chromophore also changes over the narrow pH range 8.8-9.0, indicating that subunit interactions and chromophore states are interrelated. (Author)

E. Fujimori J. Pecci

1969-01-01

408

Interlaboratory test of pH measurements in rainwater  

SciTech Connect

An interlaboratory test of pH measurements in rainwater was conducted. Various types of electrodes and junction materials were used in the test. The results of the exercise verify that there are significant differences in the pH values of low-ionic-strength solutions reported by various laboratories.

Koch, W.F.; Marinenko, G.; Paule, R.C.

1985-10-23

409

EFFECTS OF LOW PH ON REPRODUCTION OF RAINBOW TROUT  

EPA Science Inventory

Reproduction of rainbow trout, Salmo gairdneri in acidic water was studied. Adults were exposed to waters of pH 4.5, 5.0, or 5.5 during the final 6 weeks of reproductive maturation; control acidities were pH 6.5-7.1. Progeny of acid-exposed females and control males had reduced s...

410

The Undergraduate Origins of PhD Economists  

ERIC Educational Resources Information Center

|The authors document the types of undergraduate colleges and universities attended by those who earned a doctorate in economics from an American university from 1966 through 2003. They examine relationships between type of undergraduate institution and attrition and time-to-degree in PhD programs. The total number of new economics PhDs awarded to…

Siegfried, John J.; Stock, Wendy A.; Walstad, William

2007-01-01

411

GERMINATION OF SWITCHGRASS UNDER DIFFERENT TEMPERATURE AND PH REGIMES  

Technology Transfer Automated Retrieval System (TEKTRAN)

Switchgrass (Panicum virgatum L.), a native prairie grass, is being developed into a biomass energy crop. The effect of temperature and pH on the germination success of switchgrass cultivars was investigated. Seeds of eight switchgrass cultivars were germinated at five temperatures and nine pH level...

412

PhD by Publication: A Student's Perspective  

ERIC Educational Resources Information Center

|This article presents the first author's experiences as an Australian doctoral student undertaking a PhD by publication in the arena of the social sciences. She published nine articles in refereed journals and a peer-reviewed book chapter during the course of her PhD. We situate this experience in the context of current discussion about doctoral…

Robins, Lisa; Kanowski, Peter

2008-01-01

413

Teaching Ph.D.'s How to Reach Out  

ERIC Educational Resources Information Center

|Marc Aronson, a lecturer in the School of Communication and Information at Rutgers University at New Brunswick and a historian who writes books for young adults, recently suggested that all Ph.D. candidates be required to take a course he calls "Communications." The goal would be to teach Ph.D.'s--both would-be academics and those who will pursue…

Cassuto, Leonard

2012-01-01

414

What if We Made Fewer Ph.D.'s?  

ERIC Educational Resources Information Center

|Whenever a discussion opens about nonacademic employment for Ph.D.s, it is not long before someone suggests reducing graduate-school admissions. "The market for full-time scholars has fallen off a cliff lately," this argument goes, "so why not just train fewer of them?" The strategy to reduce the number of Ph.D. students recurs in those…

Cassuto, Leonard

2012-01-01

415

Predicting Computer Science Ph.D. Completion: A Case Study  

ERIC Educational Resources Information Center

|This paper presents the results of an analysis of indicators that can be used to predict whether a student will succeed in a Computer Science Ph.D. program. The analysis was conducted by studying the records of 75 students who have been in the Computer Science Ph.D. program of the University of Alabama in Huntsville. Seventy-seven variables were…

Cox, G. W.; Hughes, W. E., Jr.; Etzkorn, L. H.; Weisskopf, M. E.

2009-01-01

416

The Early Development of Electronic pH Meters  

ERIC Educational Resources Information Center

A 19-year-old undergraduate at the University of Chicago, Kenneth Goode, in 1921 came up with the idea of an electronic pH meter, worked out some of its initial problems, and set in motion an international scientific effort that culminated in the current, wide availability of electronic pH meters. Except for the replacement of vacuum tubes by…

Hines, Wallis G.; de Levie, Robert

2010-01-01

417

The diagnostic value of pleural fluid pH.  

PubMed

One hundred eighty-three patients had simultaneous blood and pleural fluid pH determinations. Thirty-six effusions were transudates, and 147 were exudates. In 46 effusions, the pleural fluid pH was less than 7.30; all 46 were exudates. A pleural fluid pH less than 7.30 was associated with the following six diagnoses: (1) empyema; (2) malignancy; (3) collagen vascular disease; (4) tuberculosis; (5) esophageal rupture; and (6) hemothorax. The results of pleural fluid pH determination are immediately available, narrow the differential diagnosis of the exudate, and may expedite patient management. The pH of pleural fluid should be measured whenever a diagnostic thoracocentesis is performed. PMID:7471845

Good, J T; Taryle, D A; Maulitz, R M; Kaplan, R L; Sahn, S A

1980-07-01

418

Production of Leuconostoc oenos Biomass under pH Control †  

PubMed Central

Leuconostoc oenos was grown on apple juice-based media. The effect of pH control on metabolism and biomass production was studied. Without pH control, L. oenos acidified the apple juice media to approximately pH 3.6. More than 75% of the malic acid was used under these conditions, but less than half of the carbohydrates was assimilated. Under pH control, biomass yields increased by 60%; most of the malic acid was used, but high levels of unfermented carbohydrates remained. The addition of tomato juice, vitamins, nucleotides, Mn+, and malic acid did not permit further increases in the cell counts; however, malic acid did induce further acidification. Growth without pH control favored a more homofermentative metabolism. Biomass production was higher in filter-sterilized apple juice media compared with that in the autoclaved media.

Champagne, Claude P.; Gardner, Nancy; Doyon, Gilles

1989-01-01

419

Signal-dependent membrane targeting by pleckstrin homology (PH) domains.  

PubMed Central

Pleckstrin homology (PH) domains are small protein modules of around 120 amino acids found in many proteins involved in cell signalling, cytoskeletal rearrangement and other processes. Although several different protein ligands have been proposed for PH domains, their only clearly demonstrated physiological function to date is to bind membrane phosphoinositides. The PH domain from phospholipase C-delta(1) binds specifically to PtdIns(4,5)P(2) and its headgroup, and has become a valuable tool for studying cellular PtdIns(4,5)P(2) functions. More recent developments have demonstrated that a subset of PH domains recognizes the products of agonist-stimulated phosphoinositide 3-kinases. Fusion of these PH domains to green fluorescent protein has allowed dramatic demonstrations of their independent ability to drive signal-dependent recruitment of their host proteins to the plasma membrane. We discuss the structural basis for this 3-phosphoinoistide recognition and the role that it plays in cellular signalling. PH domains that bind specifically to phosphoinositides comprise only a minority (perhaps 15%) of those known, raising questions as to the physiological role of the remaining 85% of PH domains. Most (if not all) PH domains bind weakly and non-specifically to phosphoinositides. Studies of dynamin-1 have indicated that oligomerization of its PH domain may be important in driving membrane association. We discuss the possibility that membrane targeting by PH domains with low affinity for phosphoinositides could be driven by alteration of their oligomeric state and thus the avidity of their membrane binding.

Lemmon, M A; Ferguson, K M

2000-01-01

420

Plant based dietary supplement increases urinary pH  

PubMed Central

Background Research has demonstrated that the net acid load of the typical Western diet has the potential to influence many aspects of human health, including osteoporosis risk/progression; obesity; cardiovascular disease risk/progression; and overall well-being. As urinary pH provides a reliable surrogate measure for dietary acid load, this study examined whether a plant-based dietary supplement, one marketed to increase alkalinity, impacts urinary pH as advertised. Methods Using pH test strips, the urinary pH of 34 healthy men and women (33.9 +/- 1.57 y, 79.3 +/- 3.1 kg) was measured for seven days to establish a baseline urinary pH without supplementation. After this initial baseline period, urinary pH was measured for an additional 14 days while participants ingested the plant-based nutritional supplement. At the end of the investigation, pH values at baseline and during the treatment period were compared to determine the efficacy of the supplement. Results Mean urinary pH statistically increased (p = 0.03) with the plant-based dietary supplement. Mean urinary pH was 6.07 +/- 0.04 during the baseline period and increased to 6.21 +/- 0.03 during the first week of treatment and to 6.27 +/- 0.06 during the second week of treatment. Conclusion Supplementation with a plant-based dietary product for at least seven days increases urinary pH, potentially increasing the alkalinity of the body.

Berardi, John M; Logan, Alan C; Rao, A Venket

2008-01-01

421

Continuous pH monitoring in a perfused bioreactor system using an optical pH sensor.  

PubMed

Monitoring and regulating the pH of the solution in a bioprocess is one of the key steps in the success of bioreactor operation. An in-line optical pH sensor, based on the optical absorption properties of phenol red present in the medium, was developed and tested in this work for use in NASA space bioreactors based on a rotating wall-perfused vessel system supporting a baby hamster kidney (BHK-21) cell culture. The sensor was tested over three 30-day and one 124-day cell runs. The pH sensor initially was calibrated and then used during the entire cell culture interval. The pH reported by the sensor was compared to that measured by a fiber optically coupled Shimadzu spectrophotometer and a blood gas analyzer. The maximum standard error of prediction for all the four cell runs for development pH sensor against BGA was +/-0.06 pH unit and for the fiber optically coupled Shimadzu spectrophotometer against the blood gas analyzer was +/-0.05 pH unit. The pH sensor system performed well without need of recalibration for 124 days. PMID:11948454

Jeevarajan, Antony S; Vani, Sundeep; Taylor, Thomas D; Anderson, Melody M

2002-05-20

422

Optical fibre PH sensor based on immobilized indicator  

NASA Astrophysics Data System (ADS)

An optical fiber pH sensor which has the immobilized pH sensitive indicator dye reagents on the tip of the optical fiber has been studied. The probe is made by covalently immobilizing the phenol red, bromine phenol blue, or bromothymol blue on the polyacrylamide microsphere fixed by polyterafluoroethylene (PTFE) film. A gap between the dye and optical fiber was used to make the diffusion of the hydrogen ions easier. The parameters of the optical fiber pH sensor have been given completely. The ranges of measurement are 3.0 - 5.0 pH, 7.0 - 8.5 pH, and 8.0 - 10.0 pH for bromine phenol blue, phenol red, and bromothymol blue, respectively. The sensitivity is 66.6 mV/pH. The probe has a precision of better than 0.55 pH. The linear correlation coefficient is 0.999. The response time is 1 - 2 min. The hysteresis is 0.52%. The repeatability is 0.013 mV, while the stability is 0.015 pH/h.

Cai, Defu; Cao, Qiang; Han, Jinghong; Cai, Jine; Li, Yating; Zhu, Zemin; Fan, Jie; Gao, Ning

1991-08-01

423

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

424

Intracellular pH in Arbuscular Mycorrhizal Fungi1  

PubMed Central

A method was developed to perform real-time analysis of cytosolic pH of arbuscular mycorrhizal fungi in culture using dye and ratiometric measurements (490/450 nm excitations). The study was mainly performed using photometric analysis, although some data were confirmed using image analysis. The use of nigericin allowed an in vivo calibration. Experimental parameters such as loading time and concentration of the dye were determined so that pH measurements could be made for a steady-state period on viable cells. A characteristic pH profile was observed along hyphae. For Gigaspora margarita, the pH of the tip (0–2 ?m) was typically 6.7, increased sharply to 7.0 behind this region (9.5 ?m), and decreased over the next 250 ?m to a constant value of 6.6. A similar pattern was obtained for Glomus intraradices. The pH profile of G. margarita germ tubes was higher when cultured in the presence of carrot (Daucus carota) hairy roots (nonmycorrhizal). Similarly, extraradical hyphae of G. intraradices had a higher apical pH than the germ tubes. The use of a paper layer to prevent the mycorrhizal roots from being in direct contact with the medium selected hyphae with an even higher cytosolic pH. Results suggest that this method could be useful as a bioassay for studying signal perception and/or H+ cotransport of nutrients by arbuscular mycorrhizal hyphae.

Jolicoeur, Mario; Germette, Sophie; Gaudette, Martin; Perrier, Michel; Becard, Guillaume

1998-01-01

425

Nanochannel pH gradient electrofocusing of proteins.  

PubMed

We demonstrate matrix-free pH gradient electrofocusing of proteins within an 85 nm deep nanochannel. In contrast to conventional isoelectric focusing where the fluid does not move, this pH gradient method traps protein molecules flowing through a channel by balancing electric forces due to pH-dependent protein charge and viscous drag forces caused by electro-osmosis. The nanoscale depth of the device and the low voltage used limit convection relative to diffusion, thus producing a stable focused band of protein. R-Phycoerythrin (RPE) and Dylight labeled streptavidin (Dyl-Strep) were focused within a nanochannel using applied voltages between 0.4 and 1.6 V. Concentration enhancement factors of over 380 have been achieved within 5 min. Varying the buffer pH (between 2.7 and 7.2) at the boundaries of the nanochannel affected the shape of the focused bands. For RPE, a pH span of 4.5 (pH 2.7 to 7.2) yielded the narrowest peak while a span of 2.4 (pH 2.7 to 5.1) produced a significantly wider peak. Such matrix-free nanofluidic devices with pH gradient electrofocusing may enable on-chip integration of orthogonal separation techniques with mass spectrometry offering labor savings and enhanced performance. PMID:23819922

Startsev, Michael A; Inglis, David W; Baker, Mark S; Goldys, Ewa M

2013-07-24

426

Jejunal surface pH measurements in tropical sprue.  

PubMed

The mucosal surface pH of jejunal biopsy samples incubated in vitro in Krebs-phosphate buffer was measured. Biopsies from 7 healthy individuals or tropical sprue subjects in complete remission had a mean surface pH of 5.8 +/- 0.09, similar to values for normal Caucasian subjects living in the UK. The mean surface pH of biopsies from 20 sprue patients, 6.0 +/- 0.08, was significantly higher (P less than 0.05) than that of the control subjects. Sprue patients could be sub-divided into those with 2 or more abnormal results in 3 intestinal function tests, and those with one or no abnormal test. The 9 low scorers showed a mean surface pH of 5.75 +/- 0.06 resembling the control mean, whereas the 11 high scorers had a higher (P less than 0.01) mean surface pH of 6.17 +/- 0.08. Mucosal surface pH correlated directly with 3 d mean faecal fat excretion and inversely with xylose and vitamin B12 absorption values but not with the nutritional indicators serum albumen, folate or blood haemoglobin levels. As in coeliac disease, mucosal surface pH in the jejunum is elevated above normal in tropical sprue and may reflect the extent to which normal ion transport processes are affected. PMID:2603196

Lucas, M L; Mathan, V I

427

Is intracellular pH a clock for mitosis?  

PubMed Central

Experiments have shown that the intracellular pH of many cells rises to a maximum at the onset of mitosis, subsequently decreasing 0.3 to 0.5 pH units by the end of mitosis. This result, and observations that tubulin net charge depends strongly on pH, may be critical for microtubule (MT) dynamics during mitosis. In vivo studies demonstrate that MT dynamics is sensitive to pH, with MT growth favored by higher pH values. Therefore it seems likely that the shift from the dominance of microtubule growth during prophase, and to a lesser extent during prometaphase, to a parity between MT polymerization and depolymerization during metaphase chromosome oscillations is a consequence of gradually decreasing intracellular pH during mitosis. Thus the timing and sequencing of prophase, prometaphase, and metaphase chromosome motions may be understood as an increase in the MT disassembly to assembly probability ratio resulting from a continuously declining intracellular pH.

2013-01-01

428

A Case of New Onset Psychosis in a Young Woman with Minimal Response to Risperidone, Ultimately Diagnosed with N-Methyl-D-Aspartate Receptor Encephalitis.  

PubMed

Anti-N-Methyl-D-Aspartate receptor (NMDAR) encephalitis is a severe, treatable and potentially reversible disorder presenting with memory deficits, psychiatric symptoms and seizures. Initially described in young patients with ovarian teratoma, the disease is meanwhile increasingly recognized also in women without tumors, in men and in children. The presence of anti-glutamate receptor (type NMDA) autoantibodies in serum or cerebrospinal fluid is specific for this novel and widely underdiagnosed disorder. We present a young women presenting with psychotic symptoms, initially treated psychiatrically, but was ultimately discovered to anti-NMDAR encephalitis. We review this disease state with respect to epidemiology, phenomenology, pathogenesis, and treatment. PMID:23773888

Spiegel, David R; Zaki, Neil

2013-06-17

429

Calculation of Estimated Ultimate Recovery for wells in continuous-type oil and gas accumulations of the Uinta-Piceance Province  

USGS Publications Warehouse

The calculation of Estimated Ultimate Recovery (EUR) from oil and gas production data of individual wells and the development of EUR distributions from all producing wells in an assessment unit are important steps in the quantitative assessment of continuous-type hydrocarbon resources. The U.S. Geological Survey has developed a method of calculating EURs for wells in continuous-type accumulations, including coal-bed gas accumulations. The EUR distribution of producing wells is used as a guide for the estimation of an EUR distribution for potential wells in areas of undiscovered resources. ?? 2003 Elsevier B.V. All rights reserved.

Cook, T.

2003-01-01

430

Crystallization and transformation of vaterite at controlled pH  

NASA Astrophysics Data System (ADS)

Precipitated calcium carbonate particles were prepared by passing CO2/N2 mixed gases into CaCl2 solution. The nucleation, crystallization and transformation of vaterite at controlled pH were investigated in this paper. The control of pH was conducted by the addition of ammonia. The results showed that addition of ammonia induced a local high supersaturation and continuous nuclei formation, which is in favor of the growth and agglomeration of vaterite nuclei while inhibiting the transformation of vaterite to calcite. The nearly pure vaterite is ready to form at the control of pH.

Sheng Han, Yong; Hadiko, Gunawan; Fuji, Masayoshi; Takahashi, Minoru

2006-03-01

431

Women Ph.D.'s Careers lag men's  

NASA Astrophysics Data System (ADS)

Numerous studies of male and female Ph.D.'s have found wide differences in academic rank and pay. Now a study by a National Research Council committee debunks the traditional reasons given to explain the disparity. This study, which analyzed matched triads of Ph.D.'s, concluded that neither the perceived greater restraints on the career mobility of women nor the greater likelihood that women will interrupt their careers for child rearing explains adequately the differences between male and female Ph.D.'s. Discrimination appears to be the most likely root.

432

Method for producing rapid pH changes  

DOEpatents

A method of initiating a rapid pH change in a solution by irradiating the solution with an intense flux of electromagnetic radiation of a frequency which produces a substantial pK change to a compound in solution. To optimize the resulting pH change, the compound being irradiated in solution should have an excited state lifetime substantially longer than the time required to establish an excited state acid-base equilibrium in the solution. Desired pH changes can be accomplished in nanoseconds or less by means of picosecond pulses of laser radiation.

Clark, John H. (Los Alamos, NM); Campillo, Anthony J. (Los Alamos, NM); Shapiro, Stanley L. (Los Alamos, NM); Winn, Kenneth R. (Los Alamos, NM)

1981-01-01

433

Platinum-Platinum Oxide Gate pH ISFET  

NASA Astrophysics Data System (ADS)

Platinum-platinum oxide gate ISFETs (ion sensitive field effect transistors) have been designed and fabricated for a stable pH microsensor. The platinum oxide layer, formed by a new fabrication process using an RF sputtering technique, was identified as PtO2 by X-ray photoelectron spectroscopy. The pH response of the platinum-platinum oxide gate ISFET was linear in the pH range between 1 and 10, and a sensitivity of 40.5± 4.0 mV/pH was obtained. The ISFET developed had better stability than a conventional Si3N4 bare gate ISFET.

Tsukada, Keiji; Miyahara, Yuji; Miyagi, Hiroyuki

1989-12-01

434

PhET Teacher Ideas & Activities: Investigating Waves  

NSDL National Science Digital Library

This is a four-page student guide developed for use with the PhET "Wave on a String" simulation. Written by a high school teacher, the activity provides a roadmap for secondary physical science students to learn about wave properties in an interactive environment. Students explore how amplitude, frequency, and wavelength affect the movement and speed of a wave. The wave simulation, which must be open and displayed to complete this activity, is available from PhET at: Wave on a String. This lesson is part of PhET (Physics Education Technology Project), a large collection of free interactive simulations for science education.

Project, The P.; Flowers, Nancy

435

PhET Teacher Ideas & Activities: Applications of Sinusoidal Functions  

NSDL National Science Digital Library

This activity is intended to supplement the "Wave on a String" PhET simulation. Students apply the concepts introduced in the computer simulation to explore properties of sinusoidal functions. They will find an equation of a wave with pre-set components and analyze how amplitude, frequency, and tension influence changes in the wave motion. The activity is intended to take ~60 minutes to complete. The wave simulation, which must be open and displayed to complete this activity, is available from PhET at: Wave on a String. This lesson is part of PhET (Physics Education Technology Project), a large collection of free interactive simulations for science education.

Sokolowski, Andrzej

436

PhET Teacher Ideas & Activities: EM Wave Analogy Tutorial  

NSDL National Science Digital Library

This item is a tutorial for introductory calculus-based physics students on the topic of waves. It was created to be used with the simulation "Wave on a String", developed by PhET (Physics Education Technology Project). The author uses sound wave analogies to prepare students for learning about electromagnetic waves. This item was approved by the PhET project, and is part of a set of teacher-created materials developed to supplement the PhET collection of interactive physics simulations.

Podolefsky, Noah S.

2008-04-18

437

New niobium complexes with alkynes. 6. Two compounds containing Nb sub 2 (PhCC(Ph)C(Ph)CPh) units joined in unorthodox ways  

SciTech Connect

Two new compounds are described that contain the recently discovered Nb{sub 2}(PhCC(Ph)C(Ph)CPh) moiety. Compound 1, (Nb{sub 4}O{sub 2}Cl{sub 4}((PhC){sub 4}){sub 2}(THF){sub 4}) {times} 2THF, contains centrosymmetric tetranuclear molecules in which the equivalent halves, Nb{sub 2}((PhC){sub 4})Cl{sub 2}(THF){sub 2}O, are joined solely by having the {mu}-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{sub 1}/c with Z = 2 and has been refined to R = 0.049 and R{sub w} = 0.066. The unit cell dimensions are a = 13.409 (2) {angstrom}, b = 27.421 (5) {angstrom}, c = 10.805 (3) {angstrom}, and {beta} = 106.76 (2){degree}. Compound 2, (Mg{sub 2}Cl{sub 3}-(THF){sub 6})(Nb{sub 4}O{sub 2}Cl{sub 7}((PhC){sub 4}){sub 2}(Mg(THF){sub 3})) {times} THF, crystallizes in space group P{anti 1} with Z = 2 and no rigorous molecular symmetry. The unit cell dimensions are a = 12.614 (2) {angstrom}, b = 16.706 (3) {angstrom}, c = 27.153 (5) {angstrom}, {alpha} = 107.45 (1){degree}, {beta} = 99.11 (1){degree}, and {gamma} = 90.61 (2){degree}.

Cotton, F.A.; Shang, Maoyu (Texas A and M Univ., College Station (USA))

1990-07-01

438

Preparing MD-PhD students for clinical rotations: navigating the interface between PhD and MD training.  

PubMed

Many aspects of MD-PhD training are not optimally designed to prepare students for their future roles as translational clinician-scientists. The transition between PhD research efforts and clinical rotations is one hurdle that must be overcome. MD-PhD students have deficits in clinical skills compared with those of their MD-only colleagues at the time of this transition. Reimmersion programs (RPs) targeted to MD-PhD students have the potential to help them navigate this transition.The authors draw on their experience creating and implementing an RP that incorporates multiple types of activities (clinical exam review, objective structured clinical examination, and supervised practice in patient care settings) designed to enhance the participants' skills and readiness for clinical efforts. On the basis of this experience, they note that MD-PhD students' time away from the clinical environment negatively affects their clinical skills, causing them to feel underprepared for clinical rotations. The authors argue that participation in an RP can help students feel more comfortable speaking with and examining patients and decrease their anxiety regarding clinical encounters. The authors propose that RPs can have positive outcomes for improving the transition from PhD to clinical MD training in dual-degree programs. Identifying and addressing this and other transitions need to be considered to improve the educational experience of MD-PhD students. PMID:23708597

Goldberg, Charles; Insel, Paul A

2013-06-01

439

MERIT Award Recipient: Lawrence J. Marnett, Ph.D.  

Cancer.gov

Cancer results from progressive irreversible changes in our genetic material (DNA) that ultimately leads the uncontrolled growth of tumor cells, increased invasiveness to surrounding tissue, and the ability to spread to other organs. A major cause of genetic mutations is chemical damage to DNA. Damaged DNA is not copied accurately so as a result mutations are introduced when the cell divides. DNA damage was once thought to result exclusively from exposure to environmental agents such as cigarette smoke, ultraviolet light, etc.

440

pH- and ionic-strength-induced structural changes in poly(acrylic acid)-lipid-based self-assembled materials.  

SciTech Connect

The effect of a polyanion introduced as a lipid conjugate (poly(acrylic acid)- dimyristoyl-sn-glycero-3-phosphoethanolamine, PAA-DMPE) on the structure of a self-assembled, biomembrane mimetic has been evaluated using synchrotron small-angle X-ray scattering (SAXS). At high grafting density (8-11 mol.%), the PAA chains were found to produce significant changes in structure in response to changes in pH and electrolyte composition. At low pH and in the absence of salt (NaCl), the neutral PAA chains adopt a coil conformational state that leads to the formation of a swollen lamellar structure. Upon the addition of salt at low to intermediate pH values, two lamellar phases, a collapsed and an expanded structure, coexist. Finally, when the polymer is fully ionized (at high pH), the extended conformation of the polymer generates a cubic phase. The results of this study contribute to an understanding of how polyelectrolytes may ultimately be harnessed for the preparation of self-assembling materials responsive to external stimuli.

Crisci, A.; Hay, D. N. T.; Seifert, S.; Firestone, M. A.

2009-01-01

441

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

442

Young-sup Yoon, MD, PhD  

Cancer.gov

Meetings & Events Home Agenda Speaker Biosketches Abstracts Logistics Contact Speaker Biosketches Young-sup Yoon, MD, PhD(School of Medicine, Emory University) The goal of his laboratory is to develop a strategy for regenerating cardiovascular

443

The Training and Work of Ph.D. Physical Scientists  

NASA Astrophysics Data System (ADS)

Doctoral education has often been viewed as the pinnacle of the formal education system. How useful is doctoral training in one's later career? In an NSF-funded project, we set out to perform a study of the training, careers, and work activities of Ph.D. physical scientists. The study included both in-depth interviews and a survey sent out to a sample of Ph.D. holders 4-8 years after graduation. Come and find out the results of this study: What skills are most Ph.D. physical scientists using? What should graduate programs be teaching? Are Ph.D.'s who are working in their specific field of training happier than their counterparts working different jobs? What skills and preparation lead to future job satisfaction, perhaps the most important indicator of the "success" of graduate education? A preprint and further details can be found at the project web site at: spot.colorado.edu/ phdcarer.

Smith, S. J.; Schweitzer, A. E.

2003-05-01

444

AASLD-FDA-NIH-PhRMA Hepatotoxicity Steering Group ...  

Center for Drug Evaluation (CDER)

... Jack Uetrecht received his Ph.D. in Organic Chemistry from Cornell University in 1972, an MD from Ohio State University of 1975 and, after a ... More results from www.fda.gov/drugs/scienceresearch/researchareas

445

Nadine Cohen, Ph.D. Senior Vice President, Regulatory ...  

Center for Drug Evaluation (CDER)

Text Version... Nadine Cohen, Ph.D. Senior Vice President, Regulatory Affairs Biogen Idec 14 ... or nurse may use the Expanded Disability Status Scale (EDSS) to ... More results from www.fda.gov/downloads/drugs/guidancecomplianceregulatoryinformation

446

AASLD-FDA-NIH-PhRMA*- Hepatotoxicity Special Interest ...  

Center for Drug Evaluation (CDER)

... AASLD-FDA-NIH-PhRMA*- Hepatotoxicity Special Interest Group Meeting, 2007 Presentations: Pre-existing liver disease DOES make DILI more ... More results from www.fda.gov/drugs/scienceresearch/researchareas

447

Physical and Chemical Characteristics of High Ph Intralipid Fat Emulsions.  

National Technical Information Service (NTIS)

Intralipid intravenous fat emulsions, that were purposely prepared to have high pH, were broken down into oil and water phases. The neutral and polar lipids and water soluble materials were examined by chromatographic procedures. Extreme differences were ...

N. Pelick J. H. Tinker J. M. Steim

1965-01-01

448

The pH of Hawaiian precipitation a preliminary report  

NASA Astrophysics Data System (ADS)

Daily or biweekly precipitation samples have been collected at various sites on the island of Hawaii since 1974. The elevations of the sites ranged from sea level to 3400 m. Samples were analyzed on the day of collection for pH and conductivity. Detection of major anions, such as sulfate and nitrate, were made on selected samples during the period. The pH data show a progressive increase of acidity with elevation. The sea level site averaged pH 5.2, in contrast to the sites above 2500 m, which averaged pH 4.3. It is postulated that the increase in acidity at higher levels might be explained by acidic materials, either natural or man-made, being transported over long distances in the mid-troposphere and being scavenged in the rain of the Hawaiian islands.

Miller, John M.; Yoshinaga, Alan M.

1981-07-01

449

PhET Teacher Ideas & Activities: Wave Clicker Questions  

NSDL National Science Digital Library

This page contains a set of 67 concept (clicker) questions with answer key on the topic of waves, available for free download in Power Point or pdf format. It is a PhET Gold Star award-winning resource, developed for use with PhET interactive simulations on waves. Concept questions are intended to introduce a topic and probe students' existing beliefs prior to formal instruction. Students discuss their viewpoints, then "vote" on the correct response to the concept question. The use of concept questions has been extensively tested by physics education researchers and correlated with improved learner outcomes. The clicker questions were created specifically to supplement the following PhET simulations: Fourier: Making Waves, Sound, Wave on a String, Wave Interference, Geometric Optics, and Resonance. This resource is part of a set of teacher-created materials developed to supplement the PhET collection of interactive physics simulations.

Project, The P.; Loeblein, Trish

450

AASLD-FDA-NIH-PhRMA*- Hepatotoxicity Special Interest ...  

Center for Drug Evaluation (CDER)

... AASLD-FDA-NIH-PhRMA*- Hepatotoxicity Special Interest Group Meeting, 2007 Presentations: Industry commentary on concept paper (Stern). ... More results from www.fda.gov/drugs/scienceresearch/researchareas

451

AASLD-FDA-NIH-PhRMA*- Hepatotoxicity Special Interest ...  

Center for Drug Evaluation (CDER)

... AASLD-FDA-NIH-PhRMA*- Hepatotoxicity Special Interest Group Meeting, 2008 Presentations: Liver test elevations seen in patients on placebo. ... More results from www.fda.gov/drugs/scienceresearch/researchareas

452

pH electrode performance under automated management conditions.  

PubMed

pH is frequently measured in laboratories, but to have confidence in the results it is necessary to know that it was measured properly. For an electrode to give accurate results it must be treated well and calibrated correctly. In this paper, an automated system for pH measurement is described; the system uses the operational pH scale and calibrates using two or three buffer solutions, taking proper account of the effects of temperature on the system. The system can be programmed with standard methods and procedures to ensure that the electrode gives the best possible performance. Calibrations and measurements within the system are reproducible, and the automated system is more robust than the manual pH meter, and requires less operator time. PMID:18924811

Comer, J E; Hibbert, C

1997-01-01

453

AASLD-FDA-NIH-PhRMA Hepatotoxicity Steering Group ...  

Center for Drug Evaluation (CDER)

... AASLD-FDA-NIH-PhRMA Hepatotoxicity Steering Group Meeting, 2006 Presentations: New developments in preclinical prediction of human ... More results from www.fda.gov/drugs/scienceresearch/researchareas

454

Addressing the common pathway underlying hypertension and diabetes in people who are obese by maximizing health: the ultimate knowledge translation gap.  

PubMed

In accordance with the WHO definition of health, this article examines the alarming discord between the epidemiology of hypertension, type 2 diabetes mellitus (T2DM), and obesity and the low profile of noninvasive (nondrug) compared with invasive (drug) interventions with respect to their prevention, reversal and management. Herein lies the ultimate knowledge translation gap and challenge in 21st century health care. Although lifestyle modification has long appeared in guidelines for medically managing these conditions, this evidence-based strategy is seldom implemented as rigorously as drug prescription. Biomedicine focuses largely on reducing signs and symptoms; the effects of the problem rather than the problem. This article highlights the evidence-based rationale supporting prioritizing the underlying causes and contributing factors for hypertension and T2DM, and, in turn, obesity. We argue that a primary focus on maximizing health could eliminate all three conditions, at best, or, at worst, minimize their severity, complications, and medication needs. To enable such knowledge translation and maximizing health outcome, the health care community needs to practice as an integrated team, and address barriers to effecting maximal health in all patients. Addressing the ultimate knowledge translation gap, by aligning the health care paradigm to 21st century needs, would constitute a major advance. PMID:21423684

Dean, Elizabeth; Lomi, Constantina; Bruno, Selma; Awad, Hamzeh; O'Donoghue, Grainne

2011-03-06

455

Osmoregulation in Dunaliella tertiolecta : effects of salt stress, and the external pH on the internal pH  

Microsoft Academic Search

The intracellular pH of the halotolerant green algae Dunaliella tertiolecta, was determined by the distribution of 5,5-dimethyl-2(14C)-oxalolidine-2,5-dione (DMO) between the cell and the surrounding medium. 5,5-dimethyl-2(14C)oxalolidine-2,4-dione was not metabolized by the algal cells. The intracellular pH of Dunaliella tertiolecta was 6.8 in the dark and 7.4 in the light. During a salt stress, after two hours, the intracellular pH was

Arun Goyal; H. Gimmler

1989-01-01

456

Comparison of pH Data Measured with a pH Sensor Array Using Different Data Fusion Methods  

PubMed Central

This paper introduces different data fusion methods which are used for an electrochemical measurement using a sensor array. In this study, we used ruthenium dioxide sensing membrane pH electrodes to form a sensor array. The sensor array was used for detecting the pH values of grape wine, generic cola drink and bottled base water. The measured pH data were used for data fusion methods to increase the reliability of the measured results, and we also compared the fusion results with other different data fusion methods.

Liao, Yi-Hung; Chou, Jung-Chuan

2012-01-01

457

Facile Ar-CF3 bond formation at Pd. Strikingly different outcomes of reductive elimination from [(Ph3P)2Pd(CF3)Ph] and [(Xantphos)Pd(CF3)Ph].  

PubMed

Facile and highly selective perfluoroalkyl-aryl reductive elimination from a metal center (Pd) has been demonstrated for the first time. At temperatures as low as 50-80 degrees C, [(Xantphos)Pd(Ph)CF3] undergoes remarkably clean decomposition to produce CF3Ph in high yield and selectivity. In contrast, analogous trifluoromethylpalladium aryls stabilized by rigid cis-chelating ligands such as dppe are completely unreactive at temperatures up to 130-140 degrees C. Decomposition of [(Ph3P)2Pd(Ph)CF3] in the presence of PhI in benzene at 60 degrees C does not produce PhCF3 but rather leads to [(Ph3P)2Pd(Ph)I] and [Ph4P]+[(Ph3P)Pd(CF3)3]- in a 2:1 ratio with high selectivity. PMID:17002347

Grushin, Vladimir V; Marshall, William J

2006-10-01

458

Iron respiration by Acidiphilium cryptum at pH 5  

Microsoft Academic Search

The growth of acidophilic iron respiring bacteria at pH>4.5 may be a key to the transition from acidic to circumneutral conditions that would occur during restoration of acid mine drainage sites. Flasks containing Acidiphilium cryptum ATCC 33463 were incubated initially under aerobic conditions in liquid medium containing Fe2(SO4)3 and glucose at an initial pH of 5. Significant iron respiration was

Azize Azra Bilgin; JoAnn Silverstein; Joy D. Jenkins

2004-01-01

459

In situ measurement of soil pH  

Microsoft Academic Search

Soil pH is one of the most important factors affecting the in situ preservation of archaeological artefacts of e.g. bone, shells and iron. It is therefore important to have good, reliable methods for determining the pH. However, in all methods that involve sampling of soil or water, loss of gaseous species such as carbon dioxide from the samples as well

Henning Matthiesen

2004-01-01

460

The computer science PH.D. program at CMU  

Microsoft Academic Search

This document provides a model of the Ph.D. program in Computer Science at Carnegie-Mellon University. The Ph.D. is viewed as a certification by the faculty that the student has a broad foundation in Computer Science and has performed original research in the area. Every incoming student is assigned advisors who are charged with guiding him and certifying his education. To

1973-01-01

461

Comment on Daphnia respiration in low pH water  

Microsoft Academic Search

The recent publication of Alibone & Fair (1981), involving the respiratory responses of Daphnia magna to low pH, is an example of a growing tendency in toxicological research on acid precipitation for laboratory-based experimental data to be misapplied to natural field situations. Through a series of experiments, the authors identified a reduction in respiration rate at lowered pH as a

R. L. France

1982-01-01

462

Ambulatory 24-hour esophageal pH monitoring  

Microsoft Academic Search

If 24-hour esophageal pH monitoring is to be a useful diagnostic tool, it must reliably discriminate gastroesophageal reflux patients despite daily variations in distal esophageal acid exposure. To address this issue, we studied 53 subjects (14 healthy normals, 14 esophagitis patients, and 25 patients with atypical symptoms) with two ambulatory pH tests performed within 10 days of each other. Intrasubject

G. J. Wiener; T. M. Morgan; J. B. Copper; D. O. Castell; J. W. Sinclair; J. E. Richter

1988-01-01

463

Agency in research learning: PhD students helping themselves  

Microsoft Academic Search

The central question of this paper is whether or not supervision, in its various forms as the dominant pedagogy of post-graduate learning, should be re-examined in terms of what is realistically possible in a massified higher education system. A mature PhD student and a novice in master's degree supervision, I am a member of a self- organised PhD support group

Liz Harrison

464

A Proposed Ph.D. Student Bill of Rights  

Microsoft Academic Search

Chairing a doctoral committee involves an ethics-driven responsibility and is critical to the suc- cess of Ph.D. candidates. This paper discusses issues concerning what prospective Ph.D. students should expect from faculty who chair their doctoral committees. From a personal perspective the author provides a set of basic rights, structured as a bill of articles, which should be afforded doc- toral

Marc Schniederjans

465

Effect of pH on root membrane potentials  

Microsoft Academic Search

The effect of pH on the root membrane potentials was studied using excised roots of Hordeum vulgare, Triticum durum, and Agropyron elongatum (barley, wheat, and tall wheatgrass respectively). The measured potentials were lower the lower the pH of the KCl in the electromotive cell used for the measurements, thus indicating the presence in the root of pH-sensitive electric fields capable

A. K. Helmy; N. Peinemann; E. A. Ferreiro

1974-01-01

466

Submersed macrophyte growth at low pH  

Microsoft Academic Search

Vallisneria americana was grown for six weeks in a greenhouse on relatively fertile sediment to test for factors other than nutrient limitation which may slow growth of this submersed macrophyte at pH 5. On the basis of dry mass accumulated, (1) low pH significantly depressed Vallisneria growth at constant free CO2 levels; (2) free CO2 enrichment, however, greatly stimulated Vallisneria

John E. Titus; Richard S. Feldman; David Grisé

1990-01-01

467

Glucosylceramide modulates endolysosomal pH in Gaucher disease.  

PubMed

GlcCer accumulation causes Gaucher disease where GlcCer breakdown is inhibited due to a hereditary deficiency in glucocerebrosidase. Glycolipids are endocytosed and targeted to the Golgi apparatus in normal cells but in Gaucher disease they are mistargeted to lysosomes. To better understand the role of GlcCer in endocytic sorting RAW macrophages were treated with Conduritol B-epoxide to inhibit GlcCer breakdown. Lipid analysis found increases in GlcCer led to accumulation of both triacylglycerol and cholesterol consistent with increased lysosomal pH. Ratio imaging of macrophages using both acridine orange and lysosensor yellow/blue to measure endolysosomal pH revealed increases in Conduritol B-epoxide treated RAW macrophages and Gaucher patient lymphoblasts. Increased endolysosomal pH was restricted to Gaucher lymphoblasts as no significant increases in pH were seen in Fabry, Krabbe, Tay-Sachs and GM1-gangliosidosis lymphoblasts. Substrate reduction therapy utilises inhibitors of GlcCer synthase to reduce storage in Gaucher disease. The addition of inhibitors of GlcCer synthesis to RAW macrophages also led to increases in cholesterol and triacylglycerol and an endolysosomal pH increase of up to 1 pH unit. GlcCer modulation appears specific since glucosylsphingosine but not galactosylsphingosine reversed the effects of GlcCer depletion. Although no acute effects on glycolipid trafficking were observed using bafilomycin A the results are consistent with a multistep model whereby increases in pH lead to altered trafficking via cholesterol accumulation. GlcCer modulates endolysosomal pH in lymphocytes suggesting an important role in normal lysosomes which may be disrupted in Gaucher disease. PMID:23628459

Sillence, Dan J

2013-04-03

468

Swiss national MD-PhD program: an outcome analysis  

Microsoft Academic Search

Purpose: This study aims at a first evaluation of the outcome of the Swiss national MD-PhD program during the last 16 years. Method: One hundred and twenty six former and current students in the Swiss national MD- PhD program were surveyed via a Web-based questionnaire in September 2007. Tw enty-four questions assessed information regarding partici- pant demographics, information on the

Katrin Kuehnle; David T. Winkler; Peter J. Meier-Abt

469

The Labor Market for New Ph.D. Economists  

Microsoft Academic Search

Presents results from a survey of 450 new (1996-97) Ph.D. economists, providing information about employment, underemployment, employers, work activities, salaries, and job satisfaction. Comparisons are made across ranks of the graduates' Ph.D. programs, sectors of employment and subfields of economics, as well as over time. Labor market outcomes for economists also are compared with those of seven other disciplines. Results

John J. Siegfried; Wendy A. Stock

1999-01-01

470

Properties of Horseshoe Object 2000 PH5 From Radar Observations  

Microsoft Academic Search

We have used radar observations from two sessions at Goldstone in 2001 and two sessions at Arecibo in 2004 to estimate physical and reflection properties of near-Earth asteroid 2000 PH5, the first object in a Sun-Earth horseshoe orbit for which we can obtain a detailed physical characterization. Its orbital parameters suggest 2000 PH5 may have originated within the Earth-Moon system

P. A. Taylor; J.-L. Margot; P. D. Nicholson; D. B. Campbell; R. F. Jurgens; S. J. Ostro; L. A. M. Benner; J. D. Giorgini; M. C. Nolan; E. S. Howell; A. A. Hine; R. S. Hudson

2004-01-01

471

Teaching Human Digestion and pH Using Technology  

ERIC Educational Resources Information Center

|Testing the pH of various liquids is one of the most popular activities in 5th- through 8th-grade classrooms. The author presents an extensive pH-testing lesson based on a 5E (engagement, exploration, explanation, extension, and evaluation) teaching model. The activity provides students with the opportunity to learn about pH and how it relates to…

Kim, Hanna

2008-01-01

472

Luminescent Gold Nanoparticles with pH Dependent Membrane Adsorption  

PubMed Central

pH regulates many cellular processes and is also an indicator of disease progression. Therefore, pH responsive materials often serve as either tools in the fundamental understanding of cell biology or medicines for disease diagnosis and therapy. While gold nanoparticles have found broad biomedical applications, very few of them exhibit pH dependent interactions with live cells in a native biological environment due to nonspecific serum protein adsorption. Herein, we report that by coating luminescent gold nanoparticles with a natural peptide, glutathione and the simplest stable aminothiol, cysteamine, we enabled the nanoparticles to exhibit not only high resistance to serum protein adsorption but also pH dependent adsorption onto the live cell membrane in the presence of serum proteins. Incorporating this pH dependent membrane adsorption behavior into gold nanoparticles could potentially catalyze new biomedical applications of metal nanoparticles in the fundamental understanding of biological processes as well as disease diagnosis and therapy, where pH changes are involved.

Yu, Mengxiao; Zhou, Chen; Liu, Jinbin; Hankins, Julia D.; Zheng, Jie

2011-01-01

473

A highly fluorescent pH sensing membrane for the alkaline pH range incorporating a BODIPY dye.  

PubMed

A robust and re-usable dipstick-type fluorescent pH sensor for the alkaline pH range was developed by embedding a brightly fluorescent boron-dipyrromethene (BODIPY) dye bearing an acidic phenol moiety into a polyurethane matrix immobilized on a 3D epoxy-functionalized polymer support. The sensor strip has a dynamic working range of pH 10.0-13.1, i.e., operates in strongly basic media where pH glass electrodes can suffer from alkaline errors, and tolerates a high electrolyte background such as simulated seawater and sewage. This work describes the preparation of the sensing material and provides insight into the features that a hydrogel sensing membrane can bestow on an embedded pH-responsive dye by means of optical spectroscopic investigations. PMID:23091817

Hecht, Mandy; Kraus, Werner; Rurack, Knut

2012-10-23

474

Comparing Metal Leaching and Toxicity from High pH, Low pH, and High Ammonia Fly Ash  

SciTech Connect

Previous work with both class F and class C fly ash indicated minimal leaching from most fly ashes tested. However, the addition of NOx removal equipment might result in higher levels of ammonia in the fly ash. We have recently been testing fly ash with a wide range of pH (3.7-12.4) originating from systems with NOx removal equipment. Leaching experiments were done using dilute CaCl2 solutions in batch and columns and a batch nitric acid method. All methods indicated that the leaching of heavy metals was different in the highest ammonia sample tested and the high pH sample. However, toxicity testing with the Microtox system has indicated little potential toxicity in leachates except for the fly ash at the highest pH (12.4). When the leachate from the high pH fly ash was neutralized, toxicity was eliminated.

Palumbo, Anthony Vito [ORNL; Phillips, Jana Randolph [ORNL; Fagan, Lisa Anne [ORNL; Drake, Meghan M [ORNL; Ruther, Rose Emily [New College of Florida, Sarasota, FL; Fisher, L. Suzanne [Tennessee Valley Authority (TVA); Amonette, J. E. [Pacific Northwest National Laboratory (PNNL)

2007-01-01

475

Comparing metal leaching and toxicity from high pH, low pH, and high ammonia fly ash  

SciTech Connect

Previous work with both class F and class C fly ash indicated minimal leaching from most fly ashes tested. However, the addition of NOx removal equipment might result in higher levels of ammonia in the fly ash. We have recently been testing fly ash with a wide range of pH (3.7–12.4) originating from systems with NOx removal equipment. Leaching experiments were done using dilute CaCl2 solutions in batch and columns and a batch nitric acid method. All methods indicated that the leaching of heavy metals was different in the highest ammonia sample tested and the high pH sample. However, toxicity testing with the Microtox* system has indicated little potential toxicity in leachates except for the fly ash at the highest pH (12.4). When the leachate from the high pH fly ash was neutralized, toxicity was eliminated.

Palumbo, Anthony V.; Tarver, Jana R.; Fagan, Lisa A.; McNeilly, Meghan S.; Ruther, Rose; Fisher, L. S.; Amonette, James E.

2007-07-01

476

Regulation of Vacuolar pH of Plant Cells  

PubMed Central

The vacuolar pH and the trans-tonoplast ?pH modifications induced by the activity of the two proton pumps H+-ATPase and H+-PPase and by the proton exchanges catalyzed by the Na+/H+ and Ca2+/H+ antiports at the tonoplast of isolated intact vacuoles prepared from Catharanthus roseus cells enriched in inorganic phosphate (Y Mathieu et al 1988 Plant Physiol [in press]) were measured using the 31P NMR technique. The H+-ATPase induced an intravacuolar acidification as large as 0.8 pH unit, building a trans-tonoplast ?pH up to 2.2 pH units. The hydrolysis of the phosphorylated substrate and the vacuolar acidification were monitored simultaneously to estimate kinetically the apparent stoichiometry between the vectorial proton pumping and the hydrolytic activity of the H+-ATPase. A ratio of H+ translocated/ATP hydrolyzed of 1.97 ± 0.06 (mean ± standard error) was calculated. Pyrophosphate-treated vacuoles were also acidified to a significant extent. The H+-PPase at 2 millimolar PPi displayed hydrolytic and vectorial activities comparable to those of the H+-ATPase, building a steady state ?pH of 2.1 pH units. Vacuoles incubated in the presence of 10 millimolar Na+ were alkalinized by 0.4 to 0.8 pH unit. It has been shown by using 23Na NMR that sodium uptake was coupled to the H+ efflux and occurred against rather large concentration gradients. For the first time, the activity of the Ca2+/H+ antiport has been measured on isolated intact vacuoles. Ca2+ uptake was strongly inhibited by NH4Cl or gramicidin. Vacuoles incubated with 1 millimolar Ca2+ were alkalinized by about 0.6 pH unit and this H+ efflux was associated to a Ca2+ uptake as demonstrated by measuring the external Ca2+ concentration with a calcium specific electrode. Steady state accumulation ratios of Ca2+ as high as 100 were reached for steady state external concentrations about 200 micromolar. The rate of Ca2+ uptake appeared markedly amplified in intact vacuoles when compared to tonoplast vesicles but the antiport displayed a much lower affinity for calcium. The different behavior of intact vacuoles compared to vesicles appears mainly to be due to differences in the surface to volume ratio and in the rates of dissipation of the pH gradient. Despite its low affinity, the Ca2+/H+ antiport has a high potential capacity to regulate cytoplasmic concentration of calcium.

Guern, Jean; Mathieu, Yves; Kurkdjian, Armen; Manigault, Pierre; Manigault, Jeanne; Gillet, Brigitte; Beloeil, Jean-Claude; Lallemand, Jean-Yves

1989-01-01

477

pH measurement and a rational and practical pH control strategy for high throughput cell culture system.  

PubMed

The number of therapeutic proteins produced by cell culture in the pharmaceutical industry continues to increase. During the early stages of manufacturing process development, hundreds of clones and various cell culture conditions are evaluated to develop a robust process to identify and select cell lines with high productivity. It is highly desirable to establish a high throughput system to accelerate process development and reduce cost. Multiwell plates and shake flasks are widely used in the industry as the scale down model for large-scale bioreactors. However, one of the limitations of these two systems is the inability to measure and control pH in a high throughput manner. As pH is an important process parameter for cell culture, this could limit the applications of these scale down model vessels. An economical, rapid, and robust pH measurement method was developed at Eli Lilly and Company by employing SNARF-4F 5-(-and 6)-carboxylic acid. The method demonstrated the ability to measure the pH values of cell culture samples in a high throughput manner. Based upon the chemical equilibrium of CO(2), HCO(3)(-), and the buffer system, i.e., HEPES, we established a mathematical model to regulate pH in multiwell plates and shake flasks. The model calculates the required %CO(2) from the incubator and the amount of sodium bicarbonate to be added to adjust pH to a preset value. The model was validated by experimental data, and pH was accurately regulated by this method. The feasibility of studying the pH effect on cell culture in 96-well plates and shake flasks was also demonstrated in this study. This work shed light on mini-bioreactor scale down model construction and paved the way for cell culture process development to improve productivity or product quality using high throughput systems. PMID:20039376

Zhou, Haiying; Purdie, Jennifer; Wang, Tongtong; Ouyang, Anli

478

Secondary pH standards and their uncertainty in the context of the problem of two pH scales  

Microsoft Academic Search

Establishing a traceability route with all measurement and uncertainty relationships determined is an important aspect of traceability, and seems to be particularly striking in pH measurement. In this paper the issue of evaluation of secondary pH standards measured with reference to a primary standard in a differential cell with free diffusion type liquid junctions is considered. Relatively high uncertainty, U=0.015,

Rouvim Kadis

2002-01-01

479

Soil pH Variation Within a Soil. II. pH Variation in a Neutral and an Alkaline Soil  

Microsoft Academic Search

Soil pH variation exists in particles of every kind of soils, including alkaline soil. The objective of this study was to examine soil pH varia-tion in a neutral and an alkaline soil using the column-leaching method. Column-leaching tests were applied to two soils (Callaway and Mount Palomar) at the depths of 0–30 and 30–60 cm. Two replicates were applied to each

Shih-Lin Hsu; Joe Hung; Arthur Wallace

2004-01-01

480

A New Technique for Measurement of Pharyngeal pH: Normal Values and Discriminating pH Threshold  

Microsoft Academic Search

Introduction  Identifying gastroesophageal reflux disease as the cause of respiratory and laryngeal complaints is difficult and depends\\u000a largely on the measurements of increased acid exposure in the upper esophagus or ideally the pharynx. The current method of\\u000a measuring pharyngeal pH environment is inaccurate and problematic due to artifacts. A newly designed pharyngeal pH probe to\\u000a avoid these artifacts has been introduced.

S. Ayazi; J. C. Lipham; J. A. Hagen; A. L. Tang; J. Zehetner; J. M. Leers; A. Oezcelik; E. Abate; F. Banki; S. R. DeMeester; T. R. DeMeester

2009-01-01

481

Symbolic Martyrdom: The Ultimate Apology.  

ERIC Educational Resources Information Center

|Examines the claim that "scaffold speeches" (speeches by individuals awaiting execution) form a discrete genre. Argues that they constitute a subgenre within the larger genre of apologia. Illustrates the subgenre through analysis of John Brown's final speech at his trial following the Harper's Ferry raid. (SR)|

Burkholder, Thomas R.

1991-01-01

482

Johnson's home the 'ultimate environment'  

SciTech Connect

A superinsulated house built in North Dakota is described. The design features cellulose and batt insulation in the attic (R-60) and polyurethane foam in the walls (R-28). Styrofoam insulation is used on the foundation and house walls with caulking to seal any leaks. Other features include: 1) a continuous vapor barrier of 4 mil polyethylene film, 2) an air-to-air heat exchanger, 3) an energy-efficient gas furnace and hot water heater, 4) energy-saving devices and appliances and 5) triple-pane windows. The heating bill for the first full winter month in the house was $32. Design concepts for superinsulation of houses are described. (JMT)

Not Available

1983-02-01

483

Bacterial endospores the ultimate survivors  

Microsoft Academic Search

Bacterial endospores are the most resistant living structures, known. Their high degree of resistance to many treatments (including heat and UV) is due to many factors and is governed by the unique spore structure. Spore core dehydration is a primary determinant of heat resistance. A specialised cell wall peptidoglycan layer, termed the cortex maintains dehydration. During germination the spore cortex

Abdelmadjid Atrih; Simon J Foster

2002-01-01

484

SUPER ESP: Ultimate Electrostatic Precipitation.  

National Technical Information Service (NTIS)

The paper discusses SUPER ESP, a new electrostatic precipitator (ESP) concept, enabling high collection efficiencies with considerably smaller collection areas than has previously been possible. The new concept allows a major reduction in ESP size by usin...

N. Plaks

1991-01-01

485

The Physics Professor's Ultimate Resources  

NSDL National Science Digital Library

Created by the CollegeOnline organization, this website corrals a number of websites together from institutions like the University of California - Irvine, the University of Kentucky, and the University of Utah. First-time visitors can scan through seven different subsections, such as "Geometry/Trigonometry", "Tools", and "Optics". A good place to start is with the "Virtual Labs", as they offer a melange of websites from physics labs around the country, complete with research summaries, interactive web activities, and so on. Moving on, the "Optics" area provides a fine explanation of visual illusions, Newton's color wheel, and a place where visitors can build their own rainbow. Finally, the site is rounded out by a nice "Miscellaneous" section that offers sine wave demonstrations, lunar phase illustrations, and a space time lab game.

486

Black Holes: The Ultimate Abyss  

NSDL National Science Digital Library

This lesson plan is part of the DiscoverySchool.com lesson plan library for grades 6-8. It focuses on the mystery of black holes, discussing the three basic sizes and how the characteristics of each type make them different from other black holes. It includes objectives, materials, procedures, discussion questions, evaluation ideas, performing extensions, suggested readings, and vocabulary. There are videos available to order which complement this lesson, audio vocabulary, and links to teaching tools for making custom quizzes, worksheets, puzzles and lesson plans.

Hennig, Lee A.

487

sp-sp3 coupling reactions of alkynylsilver cations, RC?CAg2+ (R = Me and Ph) with allyliodide.  

PubMed

Alkynylsilver cations, RC?CAg2(+) (where R = Me and Ph) have been prepared in the gas phase using multistage mass spectrometry experiments in a quadrupole ion trap mass spectrometer. Two methods were used: (i) electrospray ionisation (ESI) of a mixture of AgNO3 (in MeOH/H2O/acetic acid) and the alkyne carboxylic acid to yield the appropriate silver acetylide cations RC?CAg2(+), via a facile decarboxylation of the RC?CCO2Ag2(+) precursor; (ii) ESI of silver acetylides, RC?CAg, which yields a cluster of the type, [(RC?CAg)12Ag2Cl](+). Regardless of the method of preparation, these alkynylsilver cations, RC?CAg2(+), undergo ion-molecule reactions with allyliodide to yield the ionic products Ag2I(+) and [(RC?CCH2CH=CH2)Ag](+). The CID spectrum of [(PhC?CCH2CH=CH2)Ag](+) was compared to that of an authentic sample of the silver adduct of 5-phenyl-1-penten-4-yne. Both ions fragment to yield Ag(+) and the radical cation, PhC?CCH2CH=CH2(+)?, confirming that C-C bond coupling has taken place in the gas phase. DFT calculations were carried out on these C-C bond coupling reactions for the system R = Me. The reaction is highly exothermic and involves the initial coordination of the allyliodide to both silver atoms, with the iodine coordinating to one atom and the alkene moiety coordinating to the other. The overall mechanism of C-C bond coupling involves oxidative addition of the allyliodide followed by reductive elimination of RC?CCH2CH=CH2, to ultimately yield two sets of reaction products: (i) Ag2I(+) and RC?CCH2CH=CH2; and (ii) [(RC?CCH2CH=CH2)Ag](+) and AgI. PMID:23187760

Khairallah, George N; Williams, Craig M; Chow, Sharon; O'Hair, Richard A J

2013-07-14