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Sample records for acero 15-5 ph

  1. 17-4 PH and 15-5 PH

    NASA Technical Reports Server (NTRS)

    Johnson, Howard T.

    1995-01-01

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

  2. Stress corrosion cracking properties of 15-5PH steel

    NASA Technical Reports Server (NTRS)

    Rosa, Ferdinand

    1993-01-01

    Unexpected occurrence of failures, due to stress corrosion cracking (SCC) of structural components, indicate a need for improved characterization of materials and more advanced analytical procedures for reliably predicting structures performance. Accordingly, the purpose of this study was to determine the stress corrosion susceptibility of 15-5PH steel over a wide range of applied strain rates in a highly corrosive environment. The selected environment for this investigation was a highly acidified sodium chloride (NaCl) aqueous solution. The selected alloy for the study was a 15-5PH steel in the H900 condition. The slow strain rate technique was selected to test the metals specimens.

  3. Mechanical Property Data 15-5PH (H1025) Stainless Steel Alloy: Hot-Rolled Plate.

    DTIC Science & Technology

    1984-05-01

    fatigue data of unnotched 15 - 5PH stainless steel (H1025, longitudinal). - ~ ~ 5 l5PH Stumhuts Sisa Pmae. Csinuutae M al 110 -- R*01,Kf-3.0 R.T. 100 1.00...40 - 00 Lsishii. of. cruam Figure 2. Axial load fatigue data of notched 15 -SPH stainless steel (H1025, longitudinal). 3 I 20 15 - 5PH Stainless Stee...600 020 ; I I a -ALI AT 4W4C002 100 TO0 6W 30O 0 4 -5 0 07 Ufetime, Nw Cycles Figure 4. Axial load fatigue data of notched 15 - 5PH stainless steel

  4. FATIGUE PROPERTIES OF 17-4 PH AND 15-5 PH STEEL IN THE H-900 AND H-1050 CONDITION

    DTIC Science & Technology

    The rotating beam fatigue properties of 17-4 PH and 15-5 PH steels were evaluated for the H-900 and H- 1050 conditions. In addition, the effect of...shot peening on 15-5 PH was investigated. The results indicate that the two alloys behave similarly. Over aging to the H- 1050 results in a 5% decrease in

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

    SciTech Connect

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

    1982-01-01

    Friction and wear of 304, 15-5 PH and 440C stainless steels and of pure Fe are shown to be reduced by ion implantation of Ti and C. Mechanically polished samples were ion implanted to fluences of 2 x 10/sup 15/ Ti/mm/sup 2/ (90 to 180 keV) and 2 x 10/sup 15/ C/mm/sup 2/ (30 keV); the implantation profiles of the two elements extended to approx. 0.1 ..mu..m and approximately overlapped each other. The effects of normal load (Hertzian stresses in the range of 690 to 1840 MPa) on friction and wear were evaluated in the pin-on-disc configuration with no lubrication. 304 pins were used and are shown to give results similar to those previously reported for 440C pins. Ion implantation reduces friction coefficients by up to 80% and decreases the maximum wear depths by up to 95%, but the magnitude of reductions depends on the material and the load conditions. Transfer of material containing Ti from the implanted plates to both 304 and 440C pins was observed. A change in wear mechanism was detected in the wear tracks as the load was increased: fine-scale abrasive-type parallel grooves were present at light loads while galling was observed at high loads. 6 figures.

  6. The Structure and Properties of Diffusion Assisted Bonded Joints in 17-4 PH, Type 347, 15-5 PH and Nitronic 40 Stainless Steels

    NASA Technical Reports Server (NTRS)

    Wigley, D. A.

    1981-01-01

    Diffusion assisted bonds are formed in 17-4 PH, 15-5 PH, type 347 and Nitronic 40 stainless steels using electrodeposited copper as the bonding agent. The bonds are analyzed by conventional metallographic, electron microprobe analysis, and scanning electron microscopic techniques as well as Charpy V-notch impact tests at temperatures of 77 and 300 K. Results are discussed in terms of a postulated model for the bonding process.

  7. Plasma immersion ion implantation on 15-5PH stainless steel: influence on fatigue strength and wear resistance

    NASA Astrophysics Data System (ADS)

    Bonora, R.; Cioffi, M. O. H.; Voorwald, H. J. C.

    2017-05-01

    Surface improvement in steels is of great interest for applications in industry. The aim of this investigation is to study the effect of nitrogen ion implantation on the axial fatigue strength and wear resistance of 15-5 PH stainless steel. It is well know that electroplated coatings, which are used to improve abrasive wear and corrosion properties, affects negatively the fatigue strength. It is also important to consider requirements to reduce the use of coated materials with electroplated chromium and cadmium, that produce waste, which is harmful to health and environment. The HVOF (High velocity oxygen fuel) process provides hardness, wear strength and higher fatigue resistance in comparison to electroplated chromium. Plasma immersion ion implantation has been used to enhance the hardness, wear, fatigue and corrosion properties of metals and alloys. In the present research the fatigue life increased twice for 15-5 PH three hours PIII treated in comparison to base material. From the abrasive wear tests a lower pin mass reduction was observed, associated to the superficial treatments. The improvement of fatigue and mechanical performance is attributed to a combination of nitrides phase structure and compressive residual stresses during the PIII treatment.

  8. Microstructures of stainless steels exhibiting reduced friction and wear after implantation with Ti and C. [304; 15-5 PH; Nitronic 60; 440C

    SciTech Connect

    Follstaedt, D.M.; Yost, F.G.; Pope, L.E.

    1983-01-01

    Implantation of Ti and C into stainless steel discs of Types 304, 15-5 PH, Nitronic 60 and 440C has previously been reported to reduce wear depths by up to approx. 85% and friction by approx. 50% in unlubricated pin-on-disc tests. Our earlier studies relating microstructure to friction and wear results in Type 304 are first summarized: these indicate that the improvements in the surface mechanical properties are due to an amorphous surface layer, similar to the amorphous layer observed in pure Fe implanted with Ti and C. We have now examined the other three implanted steels and found similar amorphous layers. These results strongly suggest that the amorphous surface alloy is responsible for reduced friction and wear in all the steels. 6 figures.

  9. 30 CFR 15.5 - Test samples.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Test samples. 15.5 Section 15.5 Mineral... § 15.5 Test samples. (a) Submission of test samples. (1) The applicant shall not submit explosives or... magazine for at least 30 days before gallery tests are conducted....

  10. 30 CFR 15.5 - Test samples.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Test samples. 15.5 Section 15.5 Mineral... § 15.5 Test samples. (a) Submission of test samples. (1) The applicant shall not submit explosives or... magazine for at least 30 days before gallery tests are conducted....

  11. 30 CFR 15.5 - Test samples.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Test samples. 15.5 Section 15.5 Mineral... § 15.5 Test samples. (a) Submission of test samples. (1) The applicant shall not submit explosives or... magazine for at least 30 days before gallery tests are conducted....

  12. 43 CFR 15.5 - Wrecks.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 43 Public Lands: Interior 1 2014-10-01 2014-10-01 false Wrecks. 15.5 Section 15.5 Public Lands: Interior Office of the Secretary of the Interior KEY LARGO CORAL REEF PRESERVE § 15.5 Wrecks. No person... coral formation....

  13. 43 CFR 15.5 - Wrecks.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 43 Public Lands: Interior 1 2013-10-01 2013-10-01 false Wrecks. 15.5 Section 15.5 Public Lands: Interior Office of the Secretary of the Interior KEY LARGO CORAL REEF PRESERVE § 15.5 Wrecks. No person... coral formation....

  14. 43 CFR 15.5 - Wrecks.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 43 Public Lands: Interior 1 2011-10-01 2011-10-01 false Wrecks. 15.5 Section 15.5 Public Lands: Interior Office of the Secretary of the Interior KEY LARGO CORAL REEF PRESERVE § 15.5 Wrecks. No person... coral formation....

  15. 43 CFR 15.5 - Wrecks.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 43 Public Lands: Interior 1 2012-10-01 2011-10-01 true Wrecks. 15.5 Section 15.5 Public Lands: Interior Office of the Secretary of the Interior KEY LARGO CORAL REEF PRESERVE § 15.5 Wrecks. No person... coral formation....

  16. 46 CFR 196.15-5 - Drafts.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Drafts. 196.15-5 Section 196.15-5 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OCEANOGRAPHIC RESEARCH VESSELS OPERATIONS Test, Drills, and Inspections § 196.15-5 Drafts. (a) The master of every vessel on an ocean, coastwise, or Great Lakes voyage...

  17. 46 CFR 194.15-5 - Ventilation.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...) Ventilation of air conditioning systems serving the chemical laboratory shall be designed so that air cannot... 46 Shipping 7 2012-10-01 2012-10-01 false Ventilation. 194.15-5 Section 194.15-5 Shipping COAST....15-5 Ventilation. (a) Operations, reactions or experiments which produce toxic, noxious or...

  18. 46 CFR 194.15-5 - Ventilation.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...) Ventilation of air conditioning systems serving the chemical laboratory shall be designed so that air cannot... 46 Shipping 7 2011-10-01 2011-10-01 false Ventilation. 194.15-5 Section 194.15-5 Shipping COAST....15-5 Ventilation. (a) Operations, reactions or experiments which produce toxic, noxious or...

  19. 46 CFR 63.15-5 - Strainers.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Strainers. 63.15-5 Section 63.15-5 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING AUTOMATIC AUXILIARY BOILERS General Requirements § 63.15-5 Strainers. (a) Strainers must be installed in the fuel supply line. Each strainer must...

  20. 43 CFR 15.5 - Wrecks.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 43 Public Lands: Interior 1 2010-10-01 2010-10-01 false Wrecks. 15.5 Section 15.5 Public Lands: Interior Office of the Secretary of the Interior KEY LARGO CORAL REEF PRESERVE § 15.5 Wrecks. No person... coral formation....

  1. 46 CFR 151.15-5 - Venting.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 5 2012-10-01 2012-10-01 false Venting. 151.15-5 Section 151.15-5 Shipping COAST GUARD...) Pressure-vacuum venting. A normally closed venting system fitted with a device to automatically limit the pressure or vacuum in the tank to design limits. Pressure-vacuum relief valves shall comply with...

  2. 46 CFR 194.15-5 - Ventilation.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Ventilation. 194.15-5 Section 194.15-5 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OCEANOGRAPHIC RESEARCH VESSELS HANDLING, USE, AND CONTROL OF EXPLOSIVES AND OTHER HAZARDOUS MATERIALS Chemistry Laboratory and Scientific Laboratory § 194...

  3. 46 CFR 194.15-5 - Ventilation.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 7 2013-10-01 2013-10-01 false Ventilation. 194.15-5 Section 194.15-5 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OCEANOGRAPHIC RESEARCH VESSELS HANDLING, USE, AND CONTROL OF EXPLOSIVES AND OTHER HAZARDOUS MATERIALS Chemistry Laboratory and Scientific Laboratory § 194...

  4. 46 CFR 63.15-5 - Strainers.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Requirements § 63.15-5 Strainers. (a) Strainers must be installed in the fuel supply line. Each strainer must be self-cleaning, fitted with a bypass, or be capable of being cleaned without interrupting the fuel oil supply. (b) The strainer must not allow a quantity of air to be trapped inside which would...

  5. 46 CFR 63.15-5 - Strainers.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Requirements § 63.15-5 Strainers. (a) Strainers must be installed in the fuel supply line. Each strainer must be self-cleaning, fitted with a bypass, or be capable of being cleaned without interrupting the fuel oil supply. (b) The strainer must not allow a quantity of air to be trapped inside which would...

  6. 46 CFR 63.15-5 - Strainers.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Requirements § 63.15-5 Strainers. (a) Strainers must be installed in the fuel supply line. Each strainer must be self-cleaning, fitted with a bypass, or be capable of being cleaned without interrupting the fuel oil supply. (b) The strainer must not allow a quantity of air to be trapped inside which would...

  7. 46 CFR 63.15-5 - Strainers.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Requirements § 63.15-5 Strainers. (a) Strainers must be installed in the fuel supply line. Each strainer must be self-cleaning, fitted with a bypass, or be capable of being cleaned without interrupting the fuel oil supply. (b) The strainer must not allow a quantity of air to be trapped inside which would...

  8. 46 CFR 188.15-5 - Design of vessels.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 7 2012-10-01 2012-10-01 false Design of vessels. 188.15-5 Section 188.15-5 Shipping... PROVISIONS Equivalents § 188.15-5 Design of vessels. (a) In order not to inhibit design and application the Commandant may accept vessels of unusual, unique, special, or exotic design, both new and for conversion...

  9. 46 CFR 188.15-5 - Design of vessels.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 7 2013-10-01 2013-10-01 false Design of vessels. 188.15-5 Section 188.15-5 Shipping... PROVISIONS Equivalents § 188.15-5 Design of vessels. (a) In order not to inhibit design and application the Commandant may accept vessels of unusual, unique, special, or exotic design, both new and for conversion...

  10. 46 CFR 61.15-5 - Steam piping.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 2 2013-10-01 2013-10-01 false Steam piping. 61.15-5 Section 61.15-5 Shipping COAST... Periodic Tests of Piping Systems § 61.15-5 Steam piping. (a) Main steam piping shall be subjected to a... removed and the piping thoroughly examined. (b) All steam piping subject to pressure from the main...

  11. 46 CFR 61.15-5 - Steam piping.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 2 2011-10-01 2011-10-01 false Steam piping. 61.15-5 Section 61.15-5 Shipping COAST... Periodic Tests of Piping Systems § 61.15-5 Steam piping. (a) Main steam piping shall be subjected to a... removed and the piping thoroughly examined. (b) All steam piping subject to pressure from the main...

  12. 46 CFR 61.15-5 - Steam piping.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 2 2014-10-01 2014-10-01 false Steam piping. 61.15-5 Section 61.15-5 Shipping COAST... Periodic Tests of Piping Systems § 61.15-5 Steam piping. (a) Main steam piping shall be subjected to a... removed and the piping thoroughly examined. (b) All steam piping subject to pressure from the main...

  13. 46 CFR 61.15-5 - Steam piping.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Steam piping. 61.15-5 Section 61.15-5 Shipping COAST... Periodic Tests of Piping Systems § 61.15-5 Steam piping. (a) Main steam piping shall be subjected to a... removed and the piping thoroughly examined. (b) All steam piping subject to pressure from the main...

  14. 46 CFR 61.15-5 - Steam piping.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 2 2012-10-01 2012-10-01 false Steam piping. 61.15-5 Section 61.15-5 Shipping COAST... Periodic Tests of Piping Systems § 61.15-5 Steam piping. (a) Main steam piping shall be subjected to a... removed and the piping thoroughly examined. (b) All steam piping subject to pressure from the main...

  15. 46 CFR 167.15-5 - Authority of marine inspectors.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 7 2014-10-01 2014-10-01 false Authority of marine inspectors. 167.15-5 Section 167.15-5 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) NAUTICAL SCHOOLS PUBLIC NAUTICAL SCHOOL SHIPS Inspections § 167.15-5 Authority of marine inspectors. Marine inspectors may at any...

  16. 46 CFR 167.15-5 - Authority of marine inspectors.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 7 2013-10-01 2013-10-01 false Authority of marine inspectors. 167.15-5 Section 167.15-5 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) NAUTICAL SCHOOLS PUBLIC NAUTICAL SCHOOL SHIPS Inspections § 167.15-5 Authority of marine inspectors. Marine inspectors may at any...

  17. 46 CFR 167.15-5 - Authority of marine inspectors.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 7 2011-10-01 2011-10-01 false Authority of marine inspectors. 167.15-5 Section 167.15-5 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) NAUTICAL SCHOOLS PUBLIC NAUTICAL SCHOOL SHIPS Inspections § 167.15-5 Authority of marine inspectors. Marine inspectors may at any...

  18. 46 CFR 167.15-5 - Authority of marine inspectors.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 7 2012-10-01 2012-10-01 false Authority of marine inspectors. 167.15-5 Section 167.15-5 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) NAUTICAL SCHOOLS PUBLIC NAUTICAL SCHOOL SHIPS Inspections § 167.15-5 Authority of marine inspectors. Marine inspectors may at any...

  19. 46 CFR 167.15-5 - Authority of marine inspectors.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Authority of marine inspectors. 167.15-5 Section 167.15-5 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) NAUTICAL SCHOOLS PUBLIC NAUTICAL SCHOOL SHIPS Inspections § 167.15-5 Authority of marine inspectors. Marine inspectors may at any...

  20. 46 CFR 168.15-5 - Location of crew spaces.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 7 2012-10-01 2012-10-01 false Location of crew spaces. 168.15-5 Section 168.15-5 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) NAUTICAL SCHOOLS CIVILIAN NAUTICAL SCHOOL VESSELS Accommodations § 168.15-5 Location of crew spaces. (a) Quarters must be located so that sufficient...

  1. 46 CFR 168.15-5 - Location of crew spaces.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 7 2014-10-01 2014-10-01 false Location of crew spaces. 168.15-5 Section 168.15-5 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) NAUTICAL SCHOOLS CIVILIAN NAUTICAL SCHOOL VESSELS Accommodations § 168.15-5 Location of crew spaces. (a) Quarters must be located so that sufficient...

  2. 46 CFR 168.15-5 - Location of crew spaces.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 7 2013-10-01 2013-10-01 false Location of crew spaces. 168.15-5 Section 168.15-5 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) NAUTICAL SCHOOLS CIVILIAN NAUTICAL SCHOOL VESSELS Accommodations § 168.15-5 Location of crew spaces. (a) Quarters must be located so that sufficient...

  3. 46 CFR 111.15-5 - Battery installation.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... must be as close as possible to the engine or engines. (c) Small batteries. Small size battery... 46 Shipping 4 2010-10-01 2010-10-01 false Battery installation. 111.15-5 Section 111.15-5 Shipping... REQUIREMENTS Storage Batteries and Battery Chargers: Construction and Installation § 111.15-5 Battery...

  4. 46 CFR 72.15-5 - Structural fire protection.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 3 2010-10-01 2010-10-01 false Structural fire protection. 72.15-5 Section 72.15-5... ARRANGEMENT Ventilation § 72.15-5 Structural fire protection. See § 72.05-50 for ventilation requirements pertaining to structural fire protection....

  5. 46 CFR 46.15-5 - Engineering requirements.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 2 2012-10-01 2012-10-01 false Engineering requirements. 46.15-5 Section 46.15-5... Lakes Voyages § 46.15-5 Engineering requirements. (a) Bilge and ballast systems, piping, inlets and... subchapter F (Marine Engineering) of this chapter. ...

  6. 46 CFR 46.15-5 - Engineering requirements.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Engineering requirements. 46.15-5 Section 46.15-5... Lakes Voyages § 46.15-5 Engineering requirements. (a) Bilge and ballast systems, piping, inlets and... subchapter F (Marine Engineering) of this chapter. ...

  7. 46 CFR 46.15-5 - Engineering requirements.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 2 2011-10-01 2011-10-01 false Engineering requirements. 46.15-5 Section 46.15-5... Lakes Voyages § 46.15-5 Engineering requirements. (a) Bilge and ballast systems, piping, inlets and... subchapter F (Marine Engineering) of this chapter. ...

  8. 46 CFR 46.15-5 - Engineering requirements.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 2 2014-10-01 2014-10-01 false Engineering requirements. 46.15-5 Section 46.15-5... Lakes Voyages § 46.15-5 Engineering requirements. (a) Bilge and ballast systems, piping, inlets and... subchapter F (Marine Engineering) of this chapter. ...

  9. 46 CFR 46.15-5 - Engineering requirements.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 2 2013-10-01 2013-10-01 false Engineering requirements. 46.15-5 Section 46.15-5... Lakes Voyages § 46.15-5 Engineering requirements. (a) Bilge and ballast systems, piping, inlets and... subchapter F (Marine Engineering) of this chapter. ...

  10. 10 CFR 15.5 - Claims that are covered.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 1 2012-01-01 2012-01-01 false Claims that are covered. 15.5 Section 15.5 Energy NUCLEAR REGULATORY COMMISSION DEBT COLLECTION PROCEDURES Application and Coverage § 15.5 Claims that are covered. (a... on conduct in violation of the antitrust laws; (4) A claim under the Internal Revenue Code of...

  11. 46 CFR 111.15-5 - Battery installation.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 4 2014-10-01 2014-10-01 false Battery installation. 111.15-5 Section 111.15-5 Shipping... REQUIREMENTS Storage Batteries and Battery Chargers: Construction and Installation § 111.15-5 Battery installation. (a) Large batteries. Each large battery installation must be in a room that is only for batteries...

  12. 46 CFR 111.15-5 - Battery installation.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 4 2011-10-01 2011-10-01 false Battery installation. 111.15-5 Section 111.15-5 Shipping... REQUIREMENTS Storage Batteries and Battery Chargers: Construction and Installation § 111.15-5 Battery installation. (a) Large batteries. Each large battery installation must be in a room that is only for batteries...

  13. 46 CFR 111.15-5 - Battery installation.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 4 2013-10-01 2013-10-01 false Battery installation. 111.15-5 Section 111.15-5 Shipping... REQUIREMENTS Storage Batteries and Battery Chargers: Construction and Installation § 111.15-5 Battery installation. (a) Large batteries. Each large battery installation must be in a room that is only for batteries...

  14. 46 CFR 111.15-5 - Battery installation.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 4 2012-10-01 2012-10-01 false Battery installation. 111.15-5 Section 111.15-5 Shipping... REQUIREMENTS Storage Batteries and Battery Chargers: Construction and Installation § 111.15-5 Battery installation. (a) Large batteries. Each large battery installation must be in a room that is only for batteries...

  15. 46 CFR 72.15-5 - Structural fire protection.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 3 2013-10-01 2013-10-01 false Structural fire protection. 72.15-5 Section 72.15-5... ARRANGEMENT Ventilation § 72.15-5 Structural fire protection. See § 72.05-50 for ventilation requirements pertaining to structural fire protection. ...

  16. 46 CFR 72.15-5 - Structural fire protection.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 3 2012-10-01 2012-10-01 false Structural fire protection. 72.15-5 Section 72.15-5... ARRANGEMENT Ventilation § 72.15-5 Structural fire protection. See § 72.05-50 for ventilation requirements pertaining to structural fire protection. ...

  17. 46 CFR 72.15-5 - Structural fire protection.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 3 2011-10-01 2011-10-01 false Structural fire protection. 72.15-5 Section 72.15-5... ARRANGEMENT Ventilation § 72.15-5 Structural fire protection. See § 72.05-50 for ventilation requirements pertaining to structural fire protection. ...

  18. 46 CFR 72.15-5 - Structural fire protection.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 3 2014-10-01 2014-10-01 false Structural fire protection. 72.15-5 Section 72.15-5... ARRANGEMENT Ventilation § 72.15-5 Structural fire protection. See § 72.05-50 for ventilation requirements pertaining to structural fire protection. ...

  19. 46 CFR 189.15-5 - Alternate compliance.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 7 2011-10-01 2011-10-01 false Alternate compliance. 189.15-5 Section 189.15-5 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OCEANOGRAPHIC RESEARCH VESSELS INSPECTION AND CERTIFICATION Inspection of Vessels § 189.15-5 Alternate compliance. (a) In place of compliance with...

  20. 46 CFR 188.15-5 - Design of vessels.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 7 2011-10-01 2011-10-01 false Design of vessels. 188.15-5 Section 188.15-5 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OCEANOGRAPHIC RESEARCH VESSELS GENERAL PROVISIONS Equivalents § 188.15-5 Design of vessels. (a) In order not to inhibit design and application...

  1. 46 CFR 168.15-5 - Location of crew spaces.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 7 2011-10-01 2011-10-01 false Location of crew spaces. 168.15-5 Section 168.15-5 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) NAUTICAL SCHOOLS CIVILIAN NAUTICAL SCHOOL VESSELS Accommodations § 168.15-5 Location of crew spaces. (a) Quarters must be located so that...

  2. 46 CFR 168.15-5 - Location of crew spaces.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Location of crew spaces. 168.15-5 Section 168.15-5 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) NAUTICAL SCHOOLS CIVILIAN NAUTICAL SCHOOL VESSELS Accommodations § 168.15-5 Location of crew spaces. (a) Quarters must be located so that...

  3. 46 CFR 188.15-5 - Design of vessels.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Design of vessels. 188.15-5 Section 188.15-5 Shipping... PROVISIONS Equivalents § 188.15-5 Design of vessels. (a) In order not to inhibit design and application the Commandant may accept vessels of unusual, unique, special, or exotic design, both new and for...

  4. 46 CFR 188.15-5 - Design of vessels.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 7 2014-10-01 2014-10-01 false Design of vessels. 188.15-5 Section 188.15-5 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OCEANOGRAPHIC RESEARCH VESSELS GENERAL PROVISIONS Equivalents § 188.15-5 Design of vessels. (a) In order not to inhibit design and application...

  5. 46 CFR 32.15-5 - Whistles-T/ALL.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Whistles-T/ALL. 32.15-5 Section 32.15-5 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY TANK VESSELS SPECIAL EQUIPMENT, MACHINERY, AND HULL REQUIREMENTS Navigation Equipment § 32.15-5 Whistles—T/ALL. (a) (b) On tankships contracted for on and after November...

  6. 49 CFR 15.5 - Sensitive security information.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 1 2010-10-01 2010-10-01 false Sensitive security information. 15.5 Section 15.5 Transportation Office of the Secretary of Transportation PROTECTION OF SENSITIVE SECURITY INFORMATION § 15.5 Sensitive security information. (a) In general. In accordance with 49 U.S.C. 40119(b)(1), SSI is information...

  7. Proventricular nematodiasis in wrinkled hornbills (Aceros corrugatus).

    PubMed

    Ferrell, Shannon T; Pope, Katherine A; Gardiner, Chris; Bradway, Daniel S; Ambrose, Dana L; MacLean, Robert A; Norton, Terry M; Stedman, Nancy L; Garner, Michael M

    2009-09-01

    Three immature Sunda wrinkled hornbills (Aceros corrugatus) were diagnosed postmortem with proventricular spirurid nematodiasis. Concurrent severe disseminated larval granulomatosis in other visceral organs was considered contributory to mortality in each case. Clinical signs of nematodiasis were vague but generally consisted of weight loss, anorexia, and lethargy. Frequent antemortem fecal examinations were negative for spirurid eggs. In these present cases, based on routine histopathology, both prophylactic and empirically based therapeutic anthelmintic treatments had no evident benefit in the elimination of the proventricular nematodes. Spirurid nematodiasis may be an important cause of mortality in young hornbills.

  8. 46 CFR 32.15-5 - Whistles-T/ALL.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Navigation Equipment § 32.15-5 Whistles—T/ALL. (a) (b) On tankships contracted for on and after November 19... Engineering) of this chapter. Note: Appendix A in 33 CFR subchapter D contains the International Regulations... 46 Shipping 1 2011-10-01 2011-10-01 false Whistles-T/ALL. 32.15-5 Section 32.15-5 Shipping COAST...

  9. 46 CFR 105.15-5 - Authority of marine inspectors.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 4 2013-10-01 2013-10-01 false Authority of marine inspectors. 105.15-5 Section 105.15... COMMERCIAL FISHING VESSELS DISPENSING PETROLEUM PRODUCTS Inspection Required § 105.15-5 Authority of marine inspectors. (a) Marine inspectors may at any time lawfully inspect any vessel subject to the requirements...

  10. 46 CFR 105.15-5 - Authority of marine inspectors.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 4 2012-10-01 2012-10-01 false Authority of marine inspectors. 105.15-5 Section 105.15... COMMERCIAL FISHING VESSELS DISPENSING PETROLEUM PRODUCTS Inspection Required § 105.15-5 Authority of marine inspectors. (a) Marine inspectors may at any time lawfully inspect any vessel subject to the requirements...

  11. 46 CFR 105.15-5 - Authority of marine inspectors.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 4 2014-10-01 2014-10-01 false Authority of marine inspectors. 105.15-5 Section 105.15... COMMERCIAL FISHING VESSELS DISPENSING PETROLEUM PRODUCTS Inspection Required § 105.15-5 Authority of marine inspectors. (a) Marine inspectors may at any time lawfully inspect any vessel subject to the requirements...

  12. 46 CFR 105.15-5 - Authority of marine inspectors.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 4 2011-10-01 2011-10-01 false Authority of marine inspectors. 105.15-5 Section 105.15... COMMERCIAL FISHING VESSELS DISPENSING PETROLEUM PRODUCTS Inspection Required § 105.15-5 Authority of marine inspectors. (a) Marine inspectors may at any time lawfully inspect any vessel subject to the requirements...

  13. 46 CFR 105.15-5 - Authority of marine inspectors.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Authority of marine inspectors. 105.15-5 Section 105.15... COMMERCIAL FISHING VESSELS DISPENSING PETROLEUM PRODUCTS Inspection Required § 105.15-5 Authority of marine inspectors. (a) Marine inspectors may at any time lawfully inspect any vessel subject to the requirements...

  14. 46 CFR 12.15-5 - Physical and medical requirements.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Physical and medical requirements. 12.15-5 Section 12.15... REQUIREMENTS FOR RATING ENDORSEMENTS Qualified Member of the Engine Department § 12.15-5 Physical and medical requirements. The physical and medical requirements for an endorsement as QMED are found in § 10.215 of...

  15. 46 CFR 12.15-5 - Physical and medical requirements.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 1 2012-10-01 2012-10-01 false Physical and medical requirements. 12.15-5 Section 12.15... REQUIREMENTS FOR RATING ENDORSEMENTS Qualified Member of the Engine Department § 12.15-5 Physical and medical requirements. The physical and medical requirements for an endorsement as QMED are found in § 10.215 of this...

  16. 46 CFR 12.15-5 - Physical and medical requirements.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 1 2011-10-01 2011-10-01 false Physical and medical requirements. 12.15-5 Section 12.15... REQUIREMENTS FOR RATING ENDORSEMENTS Qualified Member of the Engine Department § 12.15-5 Physical and medical requirements. The physical and medical requirements for an endorsement as QMED are found in § 10.215 of this...

  17. Mapping of a Breast Carcinoma Tumor Suppressor Gene to Chromosome 11P15.5

    DTIC Science & Technology

    1997-07-01

    4. Fults, D., Petronio, J., Noblett, B. D., Pedone, C. A. Chromosome 11p15 deletions in human malignant astrocytomas and primitive neuroectodermal ...AD _ GRANT NUMBER DAMDI7-94-J-4175 TITLE: Mapping of a Breast Carcinoma Tumor Suppressor Gene to Chromosome 11P15.5 PRINCIPAL INVESTIGATOR: Tracey...FUNDING NUMBERS Mapping of a Breast Carcinoma Tumor Suppressor Gene to Chromosome llP15.5 DAMD17-94-J-4175 6. AUTHOR(S) Tracey Moore, Ph.D. 7

  18. Mapping of a Breast Carcinoma Tumor Suppressor Gene to Chromosome 11p15.5.

    DTIC Science & Technology

    1996-07-01

    Noblett, B. D., Pedone, C. A. Chromosome llp 15 deletions in human malignant astrocytomas and primitive neuroectodermal tumors . Genomics 14: 799-801...AD GRANT NUMBER: DAMDI7-94-J-4175 TITLE: Mapping of a Breast Carcinoma Tumor Suppressor Gene to Chromosome 11p15.5 PRINCIPAL INVESTIGATOR: Tracy...SUBTITLE 5. FUNDING NUMBERS Mapping of a Breast Carcinoma Tumor Suppressor Gene to Chromosome 11p15.5 DAMD17-94-J-4175 6. AUTHOR(S) Tracy Moore, Ph.D. 7

  19. 76 FR 67253 - Requested Administrative Waiver of the Coastwise Trade Laws: Vessel ACERO AZUL; Invitation for...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-31

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF TRANSPORTATION Maritime Administration Requested Administrative Waiver of the Coastwise Trade Laws: Vessel ACERO AZUL... the vessel ACERO AZUL is: INTENDED COMMERCIAL USE OF VESSEL: ``Passenger for hire.'' GEOGRAPHIC...

  20. 44 CFR 15.5 - Preservation of property.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... OF HOMELAND SECURITY GENERAL CONDUCT AT THE MT. WEATHER EMERGENCY ASSISTANCE CENTER AND AT THE NATIONAL EMERGENCY TRAINING CENTER § 15.5 Preservation of property. At both Mt. Weather and NETC we...

  1. 44 CFR 15.5 - Preservation of property.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... OF HOMELAND SECURITY GENERAL CONDUCT AT THE MT. WEATHER EMERGENCY ASSISTANCE CENTER AND AT THE NATIONAL EMERGENCY TRAINING CENTER § 15.5 Preservation of property. At both Mt. Weather and NETC we...

  2. 44 CFR 15.5 - Preservation of property.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... OF HOMELAND SECURITY GENERAL CONDUCT AT THE MT. WEATHER EMERGENCY ASSISTANCE CENTER AND AT THE NATIONAL EMERGENCY TRAINING CENTER § 15.5 Preservation of property. At both Mt. Weather and NETC we...

  3. 44 CFR 15.5 - Preservation of property.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... OF HOMELAND SECURITY GENERAL CONDUCT AT THE MT. WEATHER EMERGENCY ASSISTANCE CENTER AND AT THE NATIONAL EMERGENCY TRAINING CENTER § 15.5 Preservation of property. At both Mt. Weather and NETC we...

  4. 44 CFR 15.5 - Preservation of property.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... HOMELAND SECURITY GENERAL CONDUCT AT THE MT. WEATHER EMERGENCY ASSISTANCE CENTER AND AT THE NATIONAL EMERGENCY TRAINING CENTER § 15.5 Preservation of property. At both Mt. Weather and NETC we prohibit: (a) The...

  5. 46 CFR 112.15-5 - Final emergency loads.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... AND POWER SYSTEMS Emergency Loads § 112.15-5 Final emergency loads. On vessels required to have a final emergency power source by § 112.05-5(a) of this chapter, the following emergency lighting and... cargo oil and fuel oil system, if the emergency power source is the source of power to meet § 56.60(d...

  6. 46 CFR 112.15-5 - Final emergency loads.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... AND POWER SYSTEMS Emergency Loads § 112.15-5 Final emergency loads. On vessels required to have a final emergency power source by § 112.05-5(a) of this chapter, the following emergency lighting and... cargo oil and fuel oil system, if the emergency power source is the source of power to meet § 56.60(d...

  7. 46 CFR 112.15-5 - Final emergency loads.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... AND POWER SYSTEMS Emergency Loads § 112.15-5 Final emergency loads. On vessels required to have a final emergency power source by § 112.05-5(a) of this chapter, the following emergency lighting and... cargo oil and fuel oil system, if the emergency power source is the source of power to meet § 56.60(d...

  8. 46 CFR 112.15-5 - Final emergency loads.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... AND POWER SYSTEMS Emergency Loads § 112.15-5 Final emergency loads. On vessels required to have a final emergency power source by § 112.05-5(a) of this chapter, the following emergency lighting and... cargo oil and fuel oil system, if the emergency power source is the source of power to meet § 56.60(d...

  9. 46 CFR 112.15-5 - Final emergency loads.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... AND POWER SYSTEMS Emergency Loads § 112.15-5 Final emergency loads. On vessels required to have a final emergency power source by § 112.05-5(a) of this chapter, the following emergency lighting and... cargo oil and fuel oil system, if the emergency power source is the source of power to meet § 56.60(d...

  10. 33 CFR 67.15-5 - Seismographic and surveying operations.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Seismographic and surveying... Marking Requirements § 67.15-5 Seismographic and surveying operations. All stakes, casings, pipes, and... facilitate seismographic or surveying operations shall be marked, in the manner prescribed by the...

  11. 33 CFR 67.15-5 - Seismographic and surveying operations.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Seismographic and surveying... Marking Requirements § 67.15-5 Seismographic and surveying operations. All stakes, casings, pipes, and... facilitate seismographic or surveying operations shall be marked, in the manner prescribed by the...

  12. 33 CFR 67.15-5 - Seismographic and surveying operations.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Seismographic and surveying... Marking Requirements § 67.15-5 Seismographic and surveying operations. All stakes, casings, pipes, and... facilitate seismographic or surveying operations shall be marked, in the manner prescribed by the...

  13. 33 CFR 67.15-5 - Seismographic and surveying operations.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Seismographic and surveying... Marking Requirements § 67.15-5 Seismographic and surveying operations. All stakes, casings, pipes, and... facilitate seismographic or surveying operations shall be marked, in the manner prescribed by the...

  14. 33 CFR 67.15-5 - Seismographic and surveying operations.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Seismographic and surveying... Marking Requirements § 67.15-5 Seismographic and surveying operations. All stakes, casings, pipes, and... facilitate seismographic or surveying operations shall be marked, in the manner prescribed by the...

  15. Mechanical, Corrosion, and Fatigue Properties of 15-5 PH, Inconel 718, and Rene 41 Weldments

    DTIC Science & Technology

    1975-05-01

    8217 GENERAL, CREVICE, STRESS ri *ARGON ATMOSPHERE F igure 5 Welding and Heat Treaments Pene 4’ 4528 Arc Voltage - 13 Cas, cu ft/hr Arc Current, amperes - 250...Candidate materials Welding Hydrofoils Machining Postweld heat treatments Nicke]1-base alloys 20. ABSTRACT ’ContInue on reveree olde If necessary and...were ,rcp.Irec. Mechanical, faLi[gue, corlos’osion fatigue, and corrosion tests were performed on thOse material.s wil h ’tar ins post.we1d heat t

  16. 46 CFR 38.15-5 - Cargo hose-TB/ALL.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Cargo hose-TB/ALL. 38.15-5 Section 38.15-5 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY TANK VESSELS LIQUEFIED FLAMMABLE GASES Special Requirements § 38.15-5 Cargo hose—TB/ALL. (a) When the liquid and vapor line hoses used for loading and...

  17. 46 CFR 31.15-5 - Tank barges-B/ALL.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Tank barges-B/ALL. 31.15-5 Section 31.15-5 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY TANK VESSELS INSPECTION AND CERTIFICATION Manning of Tank Vessels § 31.15-5 Tank barges—B/ALL. Tank barges subject to the provisions of this subchapter need not be...

  18. 46 CFR 54.15-5 - Protective devices (modifies UG-125).

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 2 2014-10-01 2014-10-01 false Protective devices (modifies UG-125). 54.15-5 Section 54.15-5 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING PRESSURE VESSELS Pressure-Relief Devices § 54.15-5 Protective devices (modifies UG-125). (a) All pressure vessels...

  19. 46 CFR 54.15-5 - Protective devices (modifies UG-125).

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Protective devices (modifies UG-125). 54.15-5 Section 54.15-5 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING PRESSURE VESSELS Pressure-Relief Devices § 54.15-5 Protective devices (modifies UG-125). (a) All pressure vessels...

  20. 46 CFR 54.15-5 - Protective devices (modifies UG-125).

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 2 2011-10-01 2011-10-01 false Protective devices (modifies UG-125). 54.15-5 Section 54.15-5 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING PRESSURE VESSELS Pressure-Relief Devices § 54.15-5 Protective devices (modifies UG-125). (a) All pressure vessels...

  1. 46 CFR 54.15-5 - Protective devices (modifies UG-125).

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 2 2013-10-01 2013-10-01 false Protective devices (modifies UG-125). 54.15-5 Section 54.15-5 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING PRESSURE VESSELS Pressure-Relief Devices § 54.15-5 Protective devices (modifies UG-125). (a) All pressure vessels...

  2. 46 CFR 54.15-5 - Protective devices (modifies UG-125).

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 2 2012-10-01 2012-10-01 false Protective devices (modifies UG-125). 54.15-5 Section 54.15-5 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING PRESSURE VESSELS Pressure-Relief Devices § 54.15-5 Protective devices (modifies UG-125). (a) All pressure vessels...

  3. 46 CFR 95.15-5 - Quantity, pipe sizes, and discharge rates.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 4 2014-10-01 2014-10-01 false Quantity, pipe sizes, and discharge rates. 95.15-5 Section 95.15-5 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CARGO AND MISCELLANEOUS VESSELS FIRE PROTECTION EQUIPMENT Carbon Dioxide Extinguishing Systems, Details § 95.15-5 Quantity, pipe sizes, and discharge rates. (a) General. Th...

  4. 46 CFR 193.15-5 - Quantity, pipe sizes, and discharge rates.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 7 2012-10-01 2012-10-01 false Quantity, pipe sizes, and discharge rates. 193.15-5 Section 193.15-5 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OCEANOGRAPHIC RESEARCH VESSELS FIRE PROTECTION EQUIPMENT Carbon Dioxide and Clean Agent Extinguishing Systems, Details § 193.15-5 Quantity, pipe sizes, and discharge rate...

  5. 46 CFR 95.15-5 - Quantity, pipe sizes, and discharge rates.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 4 2013-10-01 2013-10-01 false Quantity, pipe sizes, and discharge rates. 95.15-5 Section 95.15-5 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CARGO AND MISCELLANEOUS VESSELS FIRE PROTECTION EQUIPMENT Carbon Dioxide Extinguishing Systems, Details § 95.15-5 Quantity, pipe sizes, and discharge rates. (a) General. Th...

  6. Determining nitrogen requirements of Aceros and Buceros hornbills.

    PubMed

    Foeken, Sijmen G; de Vries, Max; Hudson, Elisabeth; Sheppard, Christine D; Dierenfeld, Ellen S

    2008-07-01

    Over 2 months, seven feeding trials were conducted at St. Catherines Island, GA, to quantify protein intake and utilization in captive mature nonreproducing Aceros (n=3 spp.) and Buceros (n=2 spp.) Hornbills were fed homogeneous isocaloric diets. A mixture of Bird of Paradise pellets, grapes, and raisins was offered to the birds as grape-sized balls, supplemented with diced cantaloupe melon to maintain hydration. To vary the protein level (range 10.8-22.6%) within the diets, different amounts of a powdered soy protein supplement were added to the mixture. Test diets were fed for 3 consecutive days. Birds were weighed to test for differences among diets. All excreta and diet samples were collected for nitrogen (N) analysis. Feeding trials were separated by a 4-day period, in which the bird's regular diet was fed. Data were analyzed for N balance, N equilibrium (regression of N intake vs. N excretion) and body mass. Regression analysis of N balances of the nine birds showed that the N equilibriums ranged from 0.081 to 0.595 g N/kg(0.75)/d with an average of 0.387+/-0.298. No differences in N balances were found between Aceros and Buceros hornbills. The methodology of this study suggested a dietary crude protein (CP) requirement of 7.3+/-3.0% dry matter (DM) in a diet containing 4.0 kcal. However, this value was determined by extrapolation and has not been experimentally determined to be adequate. In this study, the hornbills maintained body mass on a diet containing 10.8% CP (with energy at 4.0 kcal/g DM). Zoo Biol 27:282-293, 2008. (c) 2008 Wiley-Liss, Inc.

  7. 46 CFR 59.15-5 - Stayed furnaces and combustion chambers.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 2 2014-10-01 2014-10-01 false Stayed furnaces and combustion chambers. 59.15-5 Section... TO BOILERS, PRESSURE VESSELS AND APPURTENANCES Miscellaneous Boiler Repairs § 59.15-5 Stayed furnaces and combustion chambers. (a) Where the plate forming the walls of stayed furnaces or...

  8. 46 CFR 59.15-5 - Stayed furnaces and combustion chambers.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 2 2013-10-01 2013-10-01 false Stayed furnaces and combustion chambers. 59.15-5 Section... TO BOILERS, PRESSURE VESSELS AND APPURTENANCES Miscellaneous Boiler Repairs § 59.15-5 Stayed furnaces and combustion chambers. (a) Where the plate forming the walls of stayed furnaces or...

  9. 46 CFR 59.15-5 - Stayed furnaces and combustion chambers.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 2 2012-10-01 2012-10-01 false Stayed furnaces and combustion chambers. 59.15-5 Section... TO BOILERS, PRESSURE VESSELS AND APPURTENANCES Miscellaneous Boiler Repairs § 59.15-5 Stayed furnaces and combustion chambers. (a) Where the plate forming the walls of stayed furnaces or...

  10. 46 CFR 59.15-5 - Stayed furnaces and combustion chambers.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 2 2011-10-01 2011-10-01 false Stayed furnaces and combustion chambers. 59.15-5 Section... TO BOILERS, PRESSURE VESSELS AND APPURTENANCES Miscellaneous Boiler Repairs § 59.15-5 Stayed furnaces and combustion chambers. (a) Where the plate forming the walls of stayed furnaces or...

  11. 46 CFR 59.15-5 - Stayed furnaces and combustion chambers.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Stayed furnaces and combustion chambers. 59.15-5 Section... TO BOILERS, PRESSURE VESSELS AND APPURTENANCES Miscellaneous Boiler Repairs § 59.15-5 Stayed furnaces and combustion chambers. (a) Where the plate forming the walls of stayed furnaces or...

  12. 46 CFR 52.15-5 - Tube connections (modifies PWT-9 and PWT-11).

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Tube connections (modifies PWT-9 and PWT-11). 52.15-5... BOILERS Requirements for Watertube Boilers § 52.15-5 Tube connections (modifies PWT-9 and PWT-11). (a) Tubes, pipe and nipples shall be attached to sheets, heads, headers, and fittings as indicated in...

  13. 46 CFR 52.15-5 - Tube connections (modifies PWT-9 and PWT-11).

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 2 2012-10-01 2012-10-01 false Tube connections (modifies PWT-9 and PWT-11). 52.15-5... BOILERS Requirements for Watertube Boilers § 52.15-5 Tube connections (modifies PWT-9 and PWT-11). (a) Tubes, pipe and nipples shall be attached to sheets, heads, headers, and fittings as indicated in...

  14. 46 CFR 52.15-5 - Tube connections (modifies PWT-9 and PWT-11).

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 2 2014-10-01 2014-10-01 false Tube connections (modifies PWT-9 and PWT-11). 52.15-5... BOILERS Requirements for Watertube Boilers § 52.15-5 Tube connections (modifies PWT-9 and PWT-11). (a) Tubes, pipe and nipples shall be attached to sheets, heads, headers, and fittings as indicated in...

  15. 46 CFR 52.15-5 - Tube connections (modifies PWT-9 and PWT-11).

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 2 2011-10-01 2011-10-01 false Tube connections (modifies PWT-9 and PWT-11). 52.15-5... BOILERS Requirements for Watertube Boilers § 52.15-5 Tube connections (modifies PWT-9 and PWT-11). (a) Tubes, pipe and nipples shall be attached to sheets, heads, headers, and fittings as indicated in...

  16. 46 CFR 52.15-5 - Tube connections (modifies PWT-9 and PWT-11).

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 2 2013-10-01 2013-10-01 false Tube connections (modifies PWT-9 and PWT-11). 52.15-5... BOILERS Requirements for Watertube Boilers § 52.15-5 Tube connections (modifies PWT-9 and PWT-11). (a) Tubes, pipe and nipples shall be attached to sheets, heads, headers, and fittings as indicated in...

  17. Tropical hornbills (Aceros cassidix, Aceros undulatus, and Buceros hydrocorax) use ballistic transport to feed with their large beaks.

    PubMed

    Baussart, Sabine; Bels, Vincent

    2011-02-01

    The most common and plesiomorphic mechanism of food transport in tetrapods is lingual-based. Neognathous birds use this mechanism for exploiting a large diversity of food resources, whereas paleognathous birds use cranioinertial mechanism with or without tongue involvement. Food transport in three hornbills' species (Aceros cassidix, A. undulatus, and Buceros hydrocorax) is defined by a ballistic transport mechanism. Only one transport cycle is used for moving the food from the tip of the beak to the pharynx. The tongue never makes contact with the food nor is it used to expand the buccal cavity. In hornbills, filmed through high-speed video, time to food release occurred between 0.11 and 0.16 sec before time to maximum gape. The ballistic curves show similar patterns. Maximum gape angle is significantly different between the three species. Each species show a different kinematic and motor pattern of head movements associated with ballistic transport. In A. undulatus, head rotation follows a continuous pattern similar to that reported earlier in toucans. A. cassidix rotates head downward at the time of maximum gape to permit food to reach the pharynx without touching the mandible. B. hydrocorax elevates the head along the transport cycle to avoid contact with the food to the cavity of the upper beak. Selection of large food items in the diet may explain the evolutionary trend of using ballistic transport in the feeding behavior of hornbills, which play a key role in tropical forest ecology by dispersing seeds.

  18. 46 CFR 193.15-5 - Quantity, pipe sizes, and discharge rates.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... VESSELS FIRE PROTECTION EQUIPMENT Carbon Dioxide and Clean Agent Extinguishing Systems, Details § 193.15-5 Quantity, pipe sizes, and discharge rates. (a) General. The amount of carbon dioxide required for each.... A separate supply of carbon dioxide need not be provided for each space protected. The total...

  19. 46 CFR 193.15-5 - Quantity, pipe sizes, and discharge rates.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... VESSELS FIRE PROTECTION EQUIPMENT Carbon Dioxide Extinguishing Systems, Details § 193.15-5 Quantity, pipe sizes, and discharge rates. (a) General. The amount of carbon dioxide required for each space shall be... supply of carbon dioxide need not be provided for each space protected. The total available supply shall...

  20. 46 CFR 34.15-5 - Quantity, pipe sizes, and discharge rates-T/ALL.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Carbon Dioxide Extinguishing Systems, Details § 34.15-5 Quantity, pipe sizes, and discharge rates—T/ALL. (a) General. (1) The amount of carbon dioxide required for each space shall be as determined by... carbon dioxide required for each space shall be equal to the gross volume of the space in cubic feet...

  1. 46 CFR 193.15-5 - Quantity, pipe sizes, and discharge rates.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... VESSELS FIRE PROTECTION EQUIPMENT Carbon Dioxide Extinguishing Systems, Details § 193.15-5 Quantity, pipe sizes, and discharge rates. (a) General. The amount of carbon dioxide required for each space shall be... supply of carbon dioxide need not be provided for each space protected. The total available supply shall...

  2. 46 CFR 34.15-5 - Quantity, pipe sizes, and discharge rates-T/ALL.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Carbon Dioxide Extinguishing Systems, Details § 34.15-5 Quantity, pipe sizes, and discharge rates—T/ALL. (a) General. (1) The amount of carbon dioxide required for each space shall be as determined by... carbon dioxide required for each space shall be equal to the gross volume of the space in cubic feet...

  3. 46 CFR 76.15-5 - Quantity, pipe sizes, and discharge rate.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... PROTECTION EQUIPMENT Carbon Dioxide Extinguishing Systems, Details § 76.15-5 Quantity, pipe sizes, and discharge rate. (a) General. The amount of carbon dioxide required for each space shall be as determined by... the purpose of determining the amount of carbon dioxide required, a cargo compartment will be...

  4. 46 CFR 193.15-5 - Quantity, pipe sizes, and discharge rates.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... VESSELS FIRE PROTECTION EQUIPMENT Carbon Dioxide and Clean Agent Extinguishing Systems, Details § 193.15-5 Quantity, pipe sizes, and discharge rates. (a) General. The amount of carbon dioxide required for each.... A separate supply of carbon dioxide need not be provided for each space protected. The total...

  5. 46 CFR 34.15-5 - Quantity, pipe sizes, and discharge rates-T/ALL.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Carbon Dioxide Extinguishing Systems, Details § 34.15-5 Quantity, pipe sizes, and discharge rates—T/ALL. (a) General. (1) The amount of carbon dioxide required for each space shall be as determined by... carbon dioxide required for each space shall be equal to the gross volume of the space in cubic feet...

  6. 46 CFR 95.15-5 - Quantity, pipe sizes, and discharge rates.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... VESSELS FIRE PROTECTION EQUIPMENT Carbon Dioxide Extinguishing Systems, Details § 95.15-5 Quantity, pipe sizes, and discharge rates. (a) General. The amount of carbon dioxide required for each space shall be... supply of carbon dioxide need not be provided for each space protected. The total available supply shall...

  7. 46 CFR 95.15-5 - Quantity, pipe sizes, and discharge rates.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... VESSELS FIRE PROTECTION EQUIPMENT Carbon Dioxide Extinguishing Systems, Details § 95.15-5 Quantity, pipe sizes, and discharge rates. (a) General. The amount of carbon dioxide required for each space shall be... supply of carbon dioxide need not be provided for each space protected. The total available supply shall...

  8. 46 CFR 76.15-5 - Quantity, pipe sizes, and discharge rate.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... PROTECTION EQUIPMENT Carbon Dioxide Extinguishing Systems, Details § 76.15-5 Quantity, pipe sizes, and discharge rate. (a) General. The amount of carbon dioxide required for each space shall be as determined by... the purpose of determining the amount of carbon dioxide required, a cargo compartment will be...

  9. 46 CFR 95.15-5 - Quantity, pipe sizes, and discharge rates.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... VESSELS FIRE PROTECTION EQUIPMENT Carbon Dioxide Extinguishing Systems, Details § 95.15-5 Quantity, pipe sizes, and discharge rates. (a) General. The amount of carbon dioxide required for each space shall be... supply of carbon dioxide need not be provided for each space protected. The total available supply shall...

  10. 46 CFR 34.15-5 - Quantity, pipe sizes, and discharge rates-T/ALL.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Carbon Dioxide Extinguishing Systems, Details § 34.15-5 Quantity, pipe sizes, and discharge rates—T/ALL. (a) General. (1) The amount of carbon dioxide required for each space shall be as determined by... carbon dioxide required for each space shall be equal to the gross volume of the space in cubic feet...

  11. 46 CFR 76.15-5 - Quantity, pipe sizes, and discharge rate.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... PROTECTION EQUIPMENT Carbon Dioxide Extinguishing Systems, Details § 76.15-5 Quantity, pipe sizes, and discharge rate. (a) General. The amount of carbon dioxide required for each space shall be as determined by... the purpose of determining the amount of carbon dioxide required, a cargo compartment will be...

  12. 46 CFR 76.15-5 - Quantity, pipe sizes, and discharge rate.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... PROTECTION EQUIPMENT Carbon Dioxide Extinguishing Systems, Details § 76.15-5 Quantity, pipe sizes, and discharge rate. (a) General. The amount of carbon dioxide required for each space shall be as determined by... the purpose of determining the amount of carbon dioxide required, a cargo compartment will be...

  13. 46 CFR 76.15-5 - Quantity, pipe sizes, and discharge rate.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... PROTECTION EQUIPMENT Carbon Dioxide Extinguishing Systems, Details § 76.15-5 Quantity, pipe sizes, and discharge rate. (a) General. The amount of carbon dioxide required for each space shall be as determined by... the purpose of determining the amount of carbon dioxide required, a cargo compartment will be...

  14. 46 CFR 34.15-5 - Quantity, pipe sizes, and discharge rates-T/ALL.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Carbon Dioxide Extinguishing Systems, Details § 34.15-5 Quantity, pipe sizes, and discharge rates—T/ALL. (a) General. (1) The amount of carbon dioxide required for each space shall be as determined by... carbon dioxide required for each space shall be equal to the gross volume of the space in cubic feet...

  15. 46 CFR 38.15-5 - Cargo hose-TB/ALL.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... § 38.15-5 Cargo hose—TB/ALL. (a) When the liquid and vapor line hoses used for loading and discharging the cargo are carried on board the vessel, they shall be of flexible metal and fabricated of seamless...

  16. 46 CFR 38.15-5 - Cargo hose-TB/ALL.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... § 38.15-5 Cargo hose—TB/ALL. (a) When the liquid and vapor line hoses used for loading and discharging the cargo are carried on board the vessel, they shall be of flexible metal and fabricated of seamless...

  17. 41 CFR 302-15.5 - Is my agency required to authorize payment for property management services?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... authorize payment for property management services? 302-15.5 Section 302-15.5 Public Contracts and Property...-ALLOWANCE FOR PROPERTY MANAGEMENT SERVICES General Rules for the Employee § 302-15.5 Is my agency required to authorize payment for property management services? No, your agency is not required to authorize...

  18. Mapping a tumor suppressor gene in 11p15.5

    SciTech Connect

    Reid, L.; West, A.; Gioeli, D.

    1994-09-01

    We are mapping a tumor suppressor gene in 11p15.5 which is associated with Wilms` tumors (WT), a pediatric kidney cancer. This gene was identified in a functional assay that analyzes the effect of human chromosomes on tumorigenicity by transferring them into the G401 WT cell line. WT hybrids containing an introduced t(X;11) chromosome do not form tumors after subcutaneous injection into nude mice, while other hybrids with different introduced chromosomes remain tumorigenic. In order to better map the tumor suppressor gene, we created a series of deletions in the t(X;11) chromosomes by {gamma}-radiation. Interestingly, three of the radiation-reduced chromosomes are indistinguishable as determined by cytogenetic, Southern blot, and PCR analyses. Upon transfer of these chromosomes into the G401 WT cells, one of the chromosomes retains tumor suppressor activity, while the two other chromosomes lack this ability. We propose two hypotheses to explain the functional difference observed between the indistinguishable chromosomes. First, the chromosome with suppressor activity may contain a region of DNA absent in the other two chromosomes. This proposal would localize the tumor suppressor gene to a 200 kb region of 11p15.5 between D11S648 and D11S601. Alternatively, the indistinguishable chromosomes may be derived from the same clone and their functional differences may indicate that the tumor suppressor gene is imprinted. That is, the tumor suppressor gene may be present on each of the three chromosomes, but not expressed on two of them due to imprinting differences. The H19 gene, located in 11p15.5, is imprinted and was recently shown to have tumor suppressor activity. However, H19 expression does not correlate with tumor suppression in our assay. Instead, we may be tracking a new imprinted gene in 11p15.5.

  19. Experimental verification of bremsstrahlung production and dosimetry predictions for 15. 5 MeV electrons

    SciTech Connect

    Sanford, T.W.L.; Beutler, D.E.; Halbleib, J.A. ); Knott, D.P. )

    1991-11-01

    The radiation produced by a 15.5-Mev mono-energetic electron beam incident on optimized and non-optimized bremsstrahlung targets is characterized using the ITS Monte Carlo code and measurements with equilibrated and non-equilibrated TLD dosimetry. Comparisons between calculations and measurements verify the calculations and demonstrate that the code can be used to predict both bremsstrahlung production and TLD response for radiation fields that are characteristic of those produced by pulsed simulators of gamma rays. At optimum bremsstrahlung production, the predicted total forward radiation fluence detected in equilibrated TLD dosimetry agrees with that measured within the {plus minus}6% uncertainty of the measurement. The absolute comparisons made here provide independent confirmation of the validity of the TLD calibration for photon fields characteristic of gamma-ray simulators. The empirical Martin equation, which is often used to calculate radiation dose from optimized bremsstrahlung targets, is examined, and its range of validity is established from the data presented.

  20. Experimental verification of bremsstrahlung production and dosimetry predictions for 15.5 MeV electrons

    SciTech Connect

    Sanford, T.W.L.; Beutler, D.E.; Halbleib, J.A.; Knott, D.P.

    1991-11-01

    The radiation produced by a 15.5-Mev mono-energetic electron beam incident on optimized and non-optimized bremsstrahlung targets is characterized using the ITS Monte Carlo code and measurements with equilibrated and non-equilibrated TLD dosimetry. Comparisons between calculations and measurements verify the calculations and demonstrate that the code can be used to predict both bremsstrahlung production and TLD response for radiation fields that are characteristic of those produced by pulsed simulators of gamma rays. At optimum bremsstrahlung production, the predicted total forward radiation fluence detected in equilibrated TLD dosimetry agrees with that measured within the {plus_minus}6% uncertainty of the measurement. The absolute comparisons made here provide independent confirmation of the validity of the TLD calibration for photon fields characteristic of gamma-ray simulators. The empirical Martin equation, which is often used to calculate radiation dose from optimized bremsstrahlung targets, is examined, and its range of validity is established from the data presented.

  1. A variant of Freeman-Sheldon syndrome maps to 11p15.5-pter

    SciTech Connect

    Krakowiak, P.A.; O`Quinn, J.R.; Watkins, W.S.

    1997-02-01

    Distal arthrogryposis type 1 (DA1) and Freeman-Sheldon syndrome (FSS) are the two most common known causes of inherited multiple congenital contractures. We recently have characterized a new disorder (DA213) with a phenotype intermediate between DA1 and FSS. We report the mapping of a gene that causes DA213 to chromosome 11p15.5-pter. Linkage analysis in a single kindred generated a positive LOD score of 5.31 at {theta} = 0 with the marker D11S922, and recombinants localize the gene to an {approximately}3.5-6.5-cM region between the marker TH and the telomere. Analysis of additional families improves the LOD score to 6.45 at {theta} = 0 and suggests linkage homogeneity for DA213. 24 refs., 4 figs., 2 tabs.

  2. On the Feasibility of Wireless Multimedia Sensor Networks over IEEE 802.15.5 Mesh Topologies

    PubMed Central

    Garcia-Sanchez, Antonio-Javier; Losilla, Fernando; Rodenas-Herraiz, David; Cruz-Martinez, Felipe; Garcia-Sanchez, Felipe

    2016-01-01

    Wireless Multimedia Sensor Networks (WMSNs) are a special type of Wireless Sensor Network (WSN) where large amounts of multimedia data are transmitted over networks composed of low power devices. Hierarchical routing protocols typically used in WSNs for multi-path communication tend to overload nodes located within radio communication range of the data collection unit or data sink. The battery life of these nodes is therefore reduced considerably, requiring frequent battery replacement work to extend the operational life of the WSN system. In a wireless sensor network with mesh topology, any node may act as a forwarder node, thereby enabling multiple routing paths toward any other node or collection unit. In addition, mesh topologies have proven advantages, such as data transmission reliability, network robustness against node failures, and potential reduction in energy consumption. This work studies the feasibility of implementing WMSNs in mesh topologies and their limitations by means of exhaustive computer simulation experiments. To this end, a module developed for the Synchronous Energy Saving (SES) mode of the IEEE 802.15.5 mesh standard has been integrated with multimedia tools to thoroughly test video sequences encoded using H.264 in mesh networks. PMID:27164106

  3. Experimental verification of bremsstrahlung production and dosimetry predictions for 15. 5 MeV electrons

    SciTech Connect

    Sanford, T.W.L.; Beutler, D.E.; Halbleib, J.A.; Knott, D.P.

    1991-01-01

    The radiation produced by a 15.5-MeV monoenergetic electron beam incident on optimized and nonoptimized bremsstrahlung targets is characterized using the ITS Monte Carlo code and measurements with equilibrated and non-equilibrated TLD dosimetry. Comparisons between calculations and measurements verify the calculations and demonstrate that the code can be used to predict both bremsstrahlung production and TLD response for radiation fields that are characteristic of those produced by pulsed simulators of gamma rays. At optimum bremsstrahlung production, the predicted total forward radiation fluence detected in equilibrated TLD dosimetry agrees with that measured within the {plus minus}6% uncertainty of the measurement. The absolute comparisons made here provide independent confirmation of the validity of the TLD calibration for photon fields characteristic of gamma-ray simulators. The empirical Martin equation, which is often used to calculate radiation dose from optimized bremsstrahlung targets, is examined, and its range of validity is established from the data presented. 23 refs., 11 figs., 2 tabs.

  4. Experimental verification of bremsstrahlung production and dosimetry predictions for 15. 5 MeV electrons

    SciTech Connect

    Sanford, T.W.L.; Beutler, D.E.; Halbleib, J.A. ); Knott, D.P. )

    1991-12-01

    In this paper the radiation produced by a 15.5-MeV mono-energetic electron beam incident on optimized and non-optimized bremsstrahlung targets is characterized using the ITS Monte Carlo code and measurements with equilibrated and non-equilibrated TLD dosimetry. Comparisons between calculations and measurements verify the calculations and demonstrate that the code can be used to predict both bremsstrahlung production and TLD response for radiation fields that are characteristic of those produced by pulsed simulators of gamma rays. At optimum bremsstrahlung production, the predicted total forward radiation fluence detected in equilibrated TLD dosimetry agrees with that measured with the {plus minus} 6% uncertainty of the measurement. The absolute comparisons made here provide independent confirmation of the validity of the TLD calibration for photon fields characteristic of gamma-ray simulators. The empirical Martin equation, which is often used to calculate radiation dose from optimized bremsstrahlung targets, is examined, and its range of validity is established from the data presented.

  5. On the Feasibility of Wireless Multimedia Sensor Networks over IEEE 802.15.5 Mesh Topologies.

    PubMed

    Garcia-Sanchez, Antonio-Javier; Losilla, Fernando; Rodenas-Herraiz, David; Cruz-Martinez, Felipe; Garcia-Sanchez, Felipe

    2016-05-05

    Wireless Multimedia Sensor Networks (WMSNs) are a special type of Wireless Sensor Network (WSN) where large amounts of multimedia data are transmitted over networks composed of low power devices. Hierarchical routing protocols typically used in WSNs for multi-path communication tend to overload nodes located within radio communication range of the data collection unit or data sink. The battery life of these nodes is therefore reduced considerably, requiring frequent battery replacement work to extend the operational life of the WSN system. In a wireless sensor network with mesh topology, any node may act as a forwarder node, thereby enabling multiple routing paths toward any other node or collection unit. In addition, mesh topologies have proven advantages, such as data transmission reliability, network robustness against node failures, and potential reduction in energy consumption. This work studies the feasibility of implementing WMSNs in mesh topologies and their limitations by means of exhaustive computer simulation experiments. To this end, a module developed for the Synchronous Energy Saving (SES) mode of the IEEE 802.15.5 mesh standard has been integrated with multimedia tools to thoroughly test video sequences encoded using H.264 in mesh networks.

  6. Assignment of the cysteinyl-tRNA synthetase gene (CARS) to 11p15. 5

    SciTech Connect

    Cruzen, M.E.; Bengtsson, U.; McMahon, J.; Wasmuth, J.J.; Arfin, S.M. )

    1993-03-01

    The attachment of each of the 20 naturally occurring amino acids to their cognate tRNA isoaccepting families is catalyzed by a specific aminoacyl-tRNA synthetase. The structural genes encoding 10 of these enzymes have been assigned to specific human chromosomes. The HARS, LARS, RARS, and TARS genes, encoding histidyl-, leucyl-, arginyl-, and threonyl-tRNA synthetases, respectively, are all located on chromosome 5( 1, 5, 7, 9, 14). The MARS (methionyl-tRNA synthetase), NARS (asparaginyl-tRNA synthetase), VARS (valyl-tRNA synthetase), and WARS (tryptophanyl-tRNA synthetase) genes have been assigned to chromosomes 12, 18, 6, and 14, respectively (3, 4, 6, 8). A gene originally identified as encoding glutaminyl-tRNA synthetase was mapped to chromosome 1q32-q42 (10). However, a recent study suggests that the product of this gene is, in fact, a multifunctional enzyme with both glutamyl- and prolyl-tRNA synthetase activities (2). The fact that 4 of the 10 aminoacyl-tRNA synthetase genes already mapped are located on chromosome 5 may be fortuitous but might also indicate an evolutionary or regulatory relatedness. It is therefore, of interest to map genes encoding other aminoacyl-tRNA synthetases to determine if additional examples of synteny exist. The recent isolation of cDNA and genomic DNA clones for human cysteinyl-tRNA synthetase has now enabled us to map the CARS gene to segment p15.5 on chromosome 11 by fluorescence in situ hybridization.

  7. Fibroadenoma in Beckwith-Wiedemann syndrome with paternal uniparental disomy of chromosome 11p15.5.

    PubMed

    Takama, Yuichi; Kubota, Akio; Nakayama, Masahiro; Higashimoto, Ken; Jozaki, Kosuke; Soejima, Hidenobu

    2014-12-01

    Herein is described a case of breast fibroadenomas in a 16-year-old girl with Beckwith-Wiedemann syndrome (BWS) and uniparental disomy (UPD) of chromosome 11p15.5. She was clinically diagnosed with BWS and direct closure was performed for an omphalocele at birth. Subtotal and 90% pancreatectomy were performed for nesidioblastosis at the ages 2 months and 8 years, respectively. Bilateral multiple breast fibroadenomas were noted at the age of 16 and 17 years. In this case, paternal UPD of chromosome 11p15.5 was identified on microsatellite marker analysis. The relevant imprinted chromosomal region in BWS is 11p15.5, and UPD of chromosome 11p15 is a risk factor for BWS-associated tumorigenicity. Chromosome 11p15.5 consists of imprinting domains of IGF2, the expression of which is associated with the tumorigenesis of various breast cancers. This case suggests that fibroadenomas occurred in association with BWS.

  8. Fatigue Crack Growth under High Pressure of Gaseous Hydrogen in a 15-5PH Martensitic Stainless Steel: Influence of Pressure and Loading Frequency

    NASA Astrophysics Data System (ADS)

    Sun, Z.; Moriconi, C.; Benoit, G.; Halm, D.; Henaff, G.

    2013-03-01

    In this study, the effect of gaseous hydrogen pressure in relation with the loading frequency on the fatigue crack growth behavior of a precipitation-hardened martensitic stainless steel is investigated. It is found that increasing the hydrogen pressure from 0.09 to 9 MPa induces an enhancement of the fatigue crack growth rates. This enhancement is pronounced particularly at higher stress intensity factor amplitudes at 9 MPa. Meanwhile, decreasing the frequency from 20 to 0.2 Hz under 0.9 MPa of hydrogen reveals a significant increase in the crack growth rates that tends to join the curve obtained under 9 MPa at 20 Hz, but with a different cracking mode. However, it is shown that the degradation in fatigue crack growth behavior derives from a complex interaction between the fatigue damage and the amount of hydrogen enriching the crack tip, which is dependent on the hydrogen pressure, loading frequency, and stress intensity factor level. Scanning electron microscope (SEM) observations of the fracture surfaces are used to support the explanations proposed to account for the observed phenomena.

  9. Dissociation energies of PH and PH+.

    NASA Astrophysics Data System (ADS)

    Reddy, R. R.; Nazeer Ahammed, Y.; Srinivasa Rao, A.; Rao, T. V. R.

    1995-12-01

    Dissociation energies for the ground electronic states of diatomic PH and PH+ are determined by fitting empirical potential functions to the respective RKRV curves using correlation coefficients. The estimated ground state dissociation energies of PH and PH+ are 3.10 and 3.20 eV respectively by the curve fitting procedure using the Lippincott potential function. The computed values are in good agreement with experimental values.

  10. Premartensitic transition and relevant magnetic effects in Ni50Mn34In15.5Al0.5 alloy.

    PubMed

    Wu, Yuqin; Guo, Shaopu; Yu, Shuyun; Cheng, Hui; Wang, Ruilong; Xiao, Haibo; Xu, Lingfang; Xiong, Rui; Liu, Yong; Xia, Zhengcai; Yang, Changping

    2016-05-16

    Resistance measurement, in situ optical microscopic observation, thermal and magnetic measurements have been carried out on Ni50Mn34In15.5Al0.5 alloy. The existence of a pronounced premartensitic transition prior to martensitic transition can be characterized by microstructure evolution as well as exothermic peak and smooth decrease of resistance and magnetization with obvious hysteresis over a wide temperature range upon cooling. Consequently, the alloy undergoes two successive magneto-structural transitions consisting of premartensitic and martensitic transitions. Magnetoelastic coupling between magnetic and structural degrees of freedom would be responsible for the appearance of premartensitic transition, as evinced by the distinct shift of transitions temperatures to lower temperature with external applied field of 50 kOe. The inverse premartensitic transition induced by magnetic field results in large magnetoresistance, and contributes to the enhanced inverse magnetocaloric effect through enlarging the peak value and temperature interval of magnetic entropy change ΔSm.

  11. Premartensitic transition and relevant magnetic effects in Ni50Mn34In15.5Al0.5 alloy

    PubMed Central

    Wu, Yuqin; Guo, Shaopu; Yu, Shuyun; Cheng, Hui; Wang, Ruilong; Xiao, Haibo; Xu, Lingfang; Xiong, Rui; Liu, Yong; Xia, Zhengcai; Yang, Changping

    2016-01-01

    Resistance measurement, in situ optical microscopic observation, thermal and magnetic measurements have been carried out on Ni50Mn34In15.5Al0.5 alloy. The existence of a pronounced premartensitic transition prior to martensitic transition can be characterized by microstructure evolution as well as exothermic peak and smooth decrease of resistance and magnetization with obvious hysteresis over a wide temperature range upon cooling. Consequently, the alloy undergoes two successive magneto-structural transitions consisting of premartensitic and martensitic transitions. Magnetoelastic coupling between magnetic and structural degrees of freedom would be responsible for the appearance of premartensitic transition, as evinced by the distinct shift of transitions temperatures to lower temperature with external applied field of 50 kOe. The inverse premartensitic transition induced by magnetic field results in large magnetoresistance, and contributes to the enhanced inverse magnetocaloric effect through enlarging the peak value and temperature interval of magnetic entropy change ΔSm. PMID:27183331

  12. Validation of High Speed Earth Atmospheric Entry Radiative Heating from 9.5 to 15.5 km/s

    NASA Technical Reports Server (NTRS)

    Brandis, A. M.; Johnston, C. O.; Cruden, B. A.; Prabhu, D. K.

    2016-01-01

    This paper presents an overview of the analysis and measurements of equilibrium radiation obtained in the NASA Ames Research Center's Electric Arc Shock Tube (EAST) facility as a part of recent testing aimed at reaching shock velocities up to 15.5 km/s. The goal of these experiments was to measure the level of radiation encountered during high speed Earth entry conditions, such as would be relevant for an asteroid, inter-planetary or lunar return mission. These experiments provide the first spectrally and spatially resolved data for high speed Earth entry and cover conditions ranging from 9.5 to 15.5 km/s at 13.3 and 26.6 Pa (0.1 and 0.2 Torr). The present analysis endeavors to provide a validation of shock tube radiation measurements and simulations at high speed conditions. A comprehensive comparison between the spectrally resolved absolute equilibrium radiance measured in EAST and the predictive tools, NEQAIR and HARA, is presented. In order to provide a more accurate representation of the agreement between the experimental and simulation results, the integrated value of radiance has been compared across four spectral regions (VUV, UV/Vis, Vis/NIR and IR) as a function of velocity. Results have generally shown excellent agreement between the two codes and EAST data for the Vis through IR spectral regions, however, discrepancies have been identified in the VUV and parts of the UV spectral regions. As a result of the analysis presented in this paper, an updated parametric uncertainty for high speed radiation in air has been evaluated to be [9.0%, -6.3%]. Furthermore, due to the nature of the radiating environment at these high shock speeds, initial calculations aimed at modeling phenomena that become more significant with increasing shock speed have been performed. These phenomena include analyzing the radiating species emitting ahead of the shock and the increased significance of radiative cooling mechanisms.

  13. "Estudio tribologico de aceros para moldes. Aplicacion al moldeo por inyeccion de polibutilentereftalato reforzado con fibra de vidrio"

    NASA Astrophysics Data System (ADS)

    Martinez Mateo, Isidoro Jose

    fabricacion del molde, tienen una gran influencia sobre su comportamiento en servicio a lo largo de la vida util del molde. En la primera parte del presente estudio, a partir de ensayos punzon sobre disco, se ha determinado la relacion entre la resistencia al desgaste y la dureza de aceros para moldes obtenidos a partir de bloques de gran espesor, estudiando los principales mecanismos de desgaste que tienen lugar. A continuacion, con el fin de determinar el dano superficial que sufren los aceros para moldes en condiciones reales de inyeccion, se han estudiado distintos tipos de aceros utilizados comercialmente en moldes de inyeccion de polimeros y materiales compuestos, seleccionando las condiciones de operacion para determinar la variacion de la rugosidad superficial del acero en funcion del material inyectado, del numero de operaciones sucesivas de inyeccion y de la orientacion del flujo de inyeccion, mediante tecnicas de perfilometria optica y microscopia electronica de barrido. Ademas del dano superficial sufrido por el acero con el numero de piezas inyectadas, tambien se ha determinado la evolucion de la rugosidad superficial de los materiales inyectados, polibutilentereftalato (PBT) puro y materiales compuestos derivados de PBT por adicion de un 20 o un 50% en peso de fibra de vidrio. En el caso de las piezas inyectadas, se ha caracterizado su microestructura en funcion del flujo de inyeccion y de la densidad de fibra, se han determinado sus propiedades termicas y dinamico-mecanicas, asi como la variacion de la rugosidad superficial de las piezas inyectadas con el numero de operaciones de inyeccion y con la geometria de las distintas secciones de las piezas. Finalmente, se ha evaluado la resistencia a la abrasion de PBT reforzado con un 50% de fibra, en funcion del numero de piezas inyectadas y de la direccion de rayado con respecto a la orientacion del flujo de inyeccion.

  14. Use of the EUR LiB 15/5 data set for radiation shielding calculations in iron

    NASA Astrophysics Data System (ADS)

    Abdo, A. El-Sayed; Bashter, I. I.; Kansouh, W. A.

    The shielding effect of an iron sphere assembly has been tested for a Pu-α-Be neutron source placed in the center of the shield assembly. Emergent neutron and gamma spectra were measured with a stilbene scintillation counter. Discrimination between neutrons and gammas was achieved by the pulse shape discrimination technique based on the zero crossing method. Calculations have been made using the one-dimensional transport code ANISN-Westinghouse version (ANISN-W) and the EUR LiB 15/5 cross section data set. The agreement between measurements and calculations indicates that the cross section set and the calculation model are suitable for studying the iron shielding experiments over the neutron energy range 1.35-10 MeV and the gamma energy range 0.3-6 MeV. Total macroscopic cross sections for fast neutrons, linear attenuation coefficients for gamma rays and half-value thicknesses for neutrons and gammas for the whole energy range and at different energies have been obtained.

  15. Hot-cracking mechanism in CO/sub 2/ laser beam welds of dissimilar metals involving PH martensitic stainless steels

    SciTech Connect

    Cieslak, M.J.

    1987-02-01

    Autogenous CO/sub 2/ laser beam welds were made between Alloy HP 9-4-20 and both 15-5 PH and PH 13-8 Mo stainless steel. Small scale circular-patch test specimens revealed that the combination involving the Nb-bearing alloy, 15-5 PH, was far more crack susceptible than the combination involving the Nb-free alloy, PH 13-8 Mo. Analytical electron microscopy was used to identify an NbC/austenite eutectic-like constituent as being responsible for the cracking phenomenon.

  16. Placental hydroxymethylation vs methylation at the imprinting control region 2 on chromosome 11p15.5.

    PubMed

    Magalhães, H R; Leite, S B P; Paz, C C P de; Duarte, G; Ramos, E S

    2013-10-22

    In addition to methylated cytosines (5-mCs), hydroxymethylcytosines (5-hmCs) are present in CpG dinucleotide-enriched regions and some transcription regulator binding sites. Unlike methylation, hydroxymethylation does not result in silencing of gene expression, and the most commonly used methods to study methylation, such as techniques based on restriction enzymatic digestion and/or bisulfite modification, are unable to distinguish between them. Genomic imprinting is a process of gene regulation where only one member of an allelic pair is expressed depending on the parental origin. Chromosome 11p15.5 has an imprinting control region (ICR2) that includes a differentially methylated region (KvDMR1) that guarantees parent-specific gene expression. The objective of the present study was to determine the presence of 5-hmC at the KvDMR1 in human placentas. We analyzed 16 third-trimester normal human placentas (chorionic villi). We compared two different methods based on real-time PCR after enzymatic digestion. The first method distinguished methylation from hydroxymethylation, while the other method did not. Unlike other methylation studies, subtle variations of methylation in ICRs could represent a drastic deregulation of the expression of imprinted genes, leading to important phenotypic consequences, and the presence of hydroxymethylation could interfere with the results of many studies. We observed agreement between the results of both methods, indicating the absence of hydroxymethylation at the KvDMR1 in third-trimester placentas. To the best of our knowledge, this is the first study describing the investigation of hydroxymethylation in human placenta using a genomic imprinting model.

  17. Placental hydroxymethylation vs methylation at the imprinting control region 2 on chromosome 11p15.5

    PubMed Central

    Magalhães, H.R.; Leite, S.B.P.; de Paz, C.C.P.; Duarte, G.; Ramos, E.S.

    2013-01-01

    In addition to methylated cytosines (5-mCs), hydroxymethylcytosines (5-hmCs) are present in CpG dinucleotide-enriched regions and some transcription regulator binding sites. Unlike methylation, hydroxymethylation does not result in silencing of gene expression, and the most commonly used methods to study methylation, such as techniques based on restriction enzymatic digestion and/or bisulfite modification, are unable to distinguish between them. Genomic imprinting is a process of gene regulation where only one member of an allelic pair is expressed depending on the parental origin. Chromosome 11p15.5 has an imprinting control region (ICR2) that includes a differentially methylated region (KvDMR1) that guarantees parent-specific gene expression. The objective of the present study was to determine the presence of 5-hmC at the KvDMR1 in human placentas. We analyzed 16 third-trimester normal human placentas (chorionic villi). We compared two different methods based on real-time PCR after enzymatic digestion. The first method distinguished methylation from hydroxymethylation, while the other method did not. Unlike other methylation studies, subtle variations of methylation in ICRs could represent a drastic deregulation of the expression of imprinted genes, leading to important phenotypic consequences, and the presence of hydroxymethylation could interfere with the results of many studies. We observed agreement between the results of both methods, indicating the absence of hydroxymethylation at the KvDMR1 in third-trimester placentas. To the best of our knowledge, this is the first study describing the investigation of hydroxymethylation in human placenta using a genomic imprinting model. PMID:24270911

  18. A cryptic familial rearrangement of 11p15.5, involving both imprinting centers, in a family with a history of short stature.

    PubMed

    Brown, Lindsay A; Rupps, Rosemarie; Peñaherrera, Maria S; Robinson, Wendy P; Patel, Millan S; Eydoux, Patrice; Boerkoel, Cornelius F

    2014-06-01

    Silver-Russell syndrome (SRS) is a heterogeneous disorder characterized by intrauterine and postnatal growth retardation, dysmorphic facial features and body asymmetry. Both hypomethylation of the telomeric imprinting control region 1 (ICR1) at 11p15.5 and maternal duplication of 11p15.5 have been implicated in the etiology of this disorder. Here we report the origin and segregation of the first reported between-arm intrachromosomal insertion of 11p15.5 that encompasses both ICR1 and ICR2 in a multigenerational family with a history of short stature. One (or any odd number) crossover within the centromeric segment during meiosis would produce recombinant chromosomes; one with a duplication of the inserted segment and the other a deletion. In this 4-generation family, there were six instances of transmission of the recombinant chromosome with duplication of the11p15.5 segment, which leads to a SRS phenotype when maternally inherited and a Beckwith-Wiedemann phenotype when paternally transmitted. The size of the duplicated region is ~1.9 Mb as determined by microarray analysis. This study provides further evidence that maternally inherited duplications of 11p15.5 result in a SRS phenotype that includes short stature and other variable features. The methylation status of the extra copy of the duplicated region of 11p15.5 ultimately predicts the resulting phenotype. Thus, the different phenotype based on parental mode of transmission is of importance in the genetic counseling of these patients.

  19. Tumor-specific loss of 11p15. 5 alleles in del11p13 Wilms tumor and in familial adrenocortical carcinoma

    SciTech Connect

    Henry, I.; Grandjouan, S.; Couillin, P.; Barichard, F.; Huerre-Jeanpierre, C.; Glaser, T.; Philip, T.; Lenoir, G.; Chaussain, J.L.; Junien, C. )

    1989-05-01

    The authors have compared constitutional and tumor genotypes in nine cases of hereditary Wilms tumor (WT) and in three unrelated cases of familial adrenocortical carcinoma (ADCC). Since susceptibility to these tumors can be observed in malformation syndromes associated with a constitutional deletion of band 11p13 (WT) and with a constitutional duplication of band 11p15.5 (WT, ADCC), they investigated these two candidate regions by using 11p polymorphic markers. As expected, somatic chromosomal events, resulting in a loss of heterozygosity limited to region 11p15.5, were observed in the tumor of two familial cases of adrenocortical carcinoma. Surprisingly, however, analysis of the WT of two patients with a constitutional deletion of band 11p13, associated with aniridia, genitourinary abnormalities, and mental retardation (WAGR syndrome), revealed a loss of heterozygosity limited to region 11p15.5. These data therefore suggest that observation of a specific loss of heterozygosity may not necessarily point to the site of the initial germinal mutation. Together with previous similar observations of a loss of heterozygosity limited to 11p15.5 in breast cancer and in rhabdomyosarcoma, the data suggest that region 11p15.5 may carry a non-tissue-specific gene that could be involved in genetic predisposition, in tumor progression, or in both.

  20. Plant Habitat (PH)

    NASA Technical Reports Server (NTRS)

    Onate, Bryan

    2016-01-01

    The International Space Station (ISS) will soon have a platform for conducting fundamental research of Large Plants. Plant Habitat (PH) is designed to be a fully controllable environment for high-quality plant physiological research. PH will control light quality, level, and timing, temperature, CO2, relative humidity, and irrigation, while scrubbing ethylene. Additional capabilities include leaf temperature and root zone moisture and oxygen sensing. The light cap will have red (630 nm), blue (450 nm), green (525 nm), far red (730 nm) and broad spectrum white LEDs. There will be several internal cameras (visible and IR) to monitor and record plant growth and operations.

  1. pH Basics

    ERIC Educational Resources Information Center

    Lunelli, Bruno; Scagnolari, Francesco

    2009-01-01

    The exposition of the pervasive concept of pH, of its foundations and implementation as a meaningful quantitative measurement, in nonspecialist university texts is often not easy to follow because too many of its theoretical and operative underpinnings are neglected. To help the inquiring student we provide a concise introduction to the depth just…

  2. pH optrode

    DOEpatents

    Northrup, M. Allen; Langry, Kevin C.

    1993-01-01

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

  3. pH Basics

    ERIC Educational Resources Information Center

    Lunelli, Bruno; Scagnolari, Francesco

    2009-01-01

    The exposition of the pervasive concept of pH, of its foundations and implementation as a meaningful quantitative measurement, in nonspecialist university texts is often not easy to follow because too many of its theoretical and operative underpinnings are neglected. To help the inquiring student we provide a concise introduction to the depth just…

  4. Ph.D. shortage

    NASA Astrophysics Data System (ADS)

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

  5. Enhancement of magnetocaloric properties near room temperature in Ga-doped Ni50Mn34.5In15.5 Heusler-type alloy

    NASA Astrophysics Data System (ADS)

    Takeuchi, A. Y.; Guimarães, C. E.; Passamani, E. C.; Larica, C.

    2012-05-01

    A martensitic Ni50Mn34.5In15.5 Heusler-type alloy doped with Ga was studied by x-ray diffractometry and magnetization measurements. Ga-doping does not affect the austenitic phase transition but shifts the martensitic phase transformation towards room temperature, producing an enhancement of the magnetic entropy change (ΔSM) in that temperature region. Large ΔSM-values in the Ga-doped samples are attained for an applied field of 30 kOe as opposed to the field of 50 kOe commonly found for the un-doped cases. These effects (enhancement of ΔSM-values, shift to temperatures close to 300 K, and large ΔSM-values at lower applied fields) make the Ga-doped Ni50Mn34.5In15.5 Heusler-type alloys good candidates for technological applications as a solid refrigerant.

  6. Synthesis, structure, and magnetic properties of the novel sodium cobalt tellurate Na5Co15.5Te6O36

    NASA Astrophysics Data System (ADS)

    Shan, Yue Jin; Yoshioka, Yuta; Wakeshima, Makoto; Tezuka, Keitaro; Imoto, Hideo

    2014-03-01

    The novel single crystal oxide Na5Co15.5Te6O36 had been successfully synthesized by a self-flux method. Na5Co15.5Te6O36 crystallizes in hexagonal symmetry, space group P63/m (No.176), with lattice parameters a=9.359 (3) Å, c=9.096 (8) Å, and Z=1. The structure is composed of combining the edge-sharing chains of octahedra, [TeO6]6- and [Co(1)O6]10- with the face-sharing chains of triangular prisms, [Co(2)O6]10- and [Co(3)(Na(3))O6]10-. Sodium ions partially occupy hexagonal channels along the c-axis that are formed by the connection of the chains. The magnetic susceptibility data show a long-range antiferromagnetic ordering with a Neel temperature of 52 K along the c axis. At temperatures above 200 K, the susceptibility corrected for the diamagnetic contribution can be fit to the Curie-Weiss law for Co2+ (S=3/2). The anisotropic ferromagnetic and antiferromagnetic feature of Na5Co15.5Te6O36 was obtained through field-dependent magnetization measurements at low temperature. The ferromagnetic and antiferromagnetic behaviors can be considered from the interactions between the Co ions in 1D zig-zag chains formed by sharing the edges of the Co(1)O6 octahedra, and the interactions between the interchain Co ions, respectively.

  7. Urine pH test

    MedlinePlus

    A urine pH test measures the level of acid in urine. ... pH - urine ... meat products, or cheese can decrease your urine pH. ... to check for changes in your urine acid levels. It may be done to ... more effective when urine is acidic or non-acidic (alkaline).

  8. The crystallization, magnetic and magnetocaloric properties in Fe 76.5-xNb xSi 15.5B 7Au 1 ribbons

    NASA Astrophysics Data System (ADS)

    Hoa, N. Q.; Gam, D. T. H.; Chau, N.; The, N. D.; Yu, S.-C.

    2007-03-01

    Fe 76.5-xNb xSi 15.5B 7Au 1 ribbons ( x=0.0, 1.5, 3.0, 4.5) have been fabricated by rapid quenching technique. The DSC measurements indicated that both first exothermal peak Tp1 (of α-Fe(Si) phase) and second peak Tp2 (of boride phase) as well as crystallization activation energy increase with increasing Nb content substituted, whereas saturation magnetization of samples decreases with x, due to ferromagnetic dilution. Besides, Curie temperature of amorphous phase decreases with x, i.e. Nb stabilizes amorphous structure of ribbons. The investigation of magnetic entropy change of studied samples showed that it may lead to magnetocaloric effect around respective Curie temperature of amorphous phase.

  9. Study on neutron irradiation effect of superconductors and installation of 15.5 T magnet in hot laboratory at IMR in Tohoku University

    NASA Astrophysics Data System (ADS)

    Nishimura, Arata; Takeuchi, Takao; Nishijima, Shigehiro; Ochiai, Kentaro; Nishijima, Gen; Watanabe, Kazuo; Narui, Minoru; Kurishita, Hiroaki; Shikama, Tatsuo

    2011-10-01

    A fusion reactor will yield a lot of high energy neutrons, and some of them will stream out of a plasma vacuum vessel and penetrate a blanket system and reach superconducting magnets which provide high magnetic field to confine high energy ionized particles. Under the neutron irradiation, the magnet materials will be activated and the properties will change. In this study, a research network on study of the irradiation effects is introduced and some data recently obtained are presented. By neutron irradiation, the critical current of the Nb 3Sn wire increased and the critical field did not change. The organic insulation materials were degraded at neutron fluence of 1 × 10 22 n/m 2. In addition, the outline of an installation plan of 15.5 T superconducting magnet into radiation control area is described and study issues are explained. The project is undergoing as a program of Nuclear Basic Infrastructure Strategic Study Initiative.

  10. Energy separations for the electronic states of PH -2,PH 2 and PH +2

    NASA Astrophysics Data System (ADS)

    Balasubramanian, K.

    1993-03-01

    All-electron complete-active space multi-configuration self-consistent field (CASSCF) followed by second-order configuration interaction (SOCI) calculations in conjunction with large P(13s10p3d2flg/7s6p3d2flg) and H (10s5p1d/8s5p1d) basis sets are made on the electronic states of PH -2, PH 2 and PH +2. We compute the adiabatic electron affinities of PH 2 and PH. The 3B 1-X 1A 1, 1B 1-X 1A 1 energy separations of PH +2 and the 2A 1-X 2B 1 energy separation of PH 2 are computed.

  11. Hemoglobins, Hemorphins, and 11p15.5 Chromosomal Region in Cancer Biology and İmmunity with Special Emphasis for Brain Tumors.

    PubMed

    Altinoz, Meric Adil; Elmaci, Ilhan; Ince, Bahri; Ozpinar, Aysel; Sav, Aydin Murat

    2016-05-01

    In systemic cancers, increased hemolysis leads to extracellular hemoglobin (HB), and experimental studies have shown its provoking role on tumor growth and metastasis. However, investigations have shown that HB chains presented by tumor vascular pericytes or serum protein complexes of HB could also induce antitumor immunity, which may be harnessed to treat refractory cancers and brain tumors. Mounting recent evidence shows that expression of HBs is not restricted to erythrocytes and that HBs exist in the cells of lung and kidney, in macrophages, and in neurons and glia of the central nervous system (CNS). HBs mediate coping with hypoxia and free radical stress in normal and tumor cells, and they are increased in certain tumors including breast, lung, colon, and squamous cell cancers. Recent studies showed HBs in meningioma, in the cyst fluid of craniopharyngioma, in the cerebrospinal fluid (CSF) of pediatric patients with posterior fossa tumors, and in glioblastoma cell lines. Hemorphins, abundant brain peptides formed via HB-chain cleavage, exert opioid activity and antiproliferative and immunomodifier effects. Hence mutations in HBs may modify brain tumorigenesis via influencing hemorphins and perturbing regulations of immune surveillance and cell growth in the neuroectodermal tissues. The β-globin gene cluster resides in the chromosome region 11p15.5, harboring important immunity genes and IGF2, H19, PHLDA2/TSSC3, TRIM3, and SLC22A18 genes associated with cancers and gliomas. 11p15.5 is a prominent region subject to epigenetic regulation. Thus the β-globin loci may exert haplotypal interactions with these. Some clues support this theory. It is well established that iron load induces liver cancer in thalassemia major; however iron load-independent associations also exist. Enhanced rates of hematologic malignancies are associated with HB Lepore, association of hemoglobin E with cholangiocarcinoma, and enhanced gastric cancer rates in the thalassemia trait. In

  12. The pH Game.

    ERIC Educational Resources Information Center

    Chemecology, 1996

    1996-01-01

    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)

  13. The pH Game.

    ERIC Educational Resources Information Center

    Chemecology, 1996

    1996-01-01

    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)

  14. Comparative Analysis of the 15.5kD Box C/D snoRNP Core Protein in the Primitive Eukaryote Giardia lamblia Reveals Unique Structural and Functional Features

    SciTech Connect

    Biswas, Shyamasri; Buhrman, Greg; Gagnon, Keith; Mattos, Carla; Brown, II, Bernard A.; Maxwell, E. Stuart

    2012-07-11

    Box C/D ribonucleoproteins (RNP) guide the 2'-O-methylation of targeted nucleotides in archaeal and eukaryotic rRNAs. The archaeal L7Ae and eukaryotic 15.5kD box C/D RNP core protein homologues initiate RNP assembly by recognizing kink-turn (K-turn) motifs. The crystal structure of the 15.5kD core protein from the primitive eukaryote Giardia lamblia is described here to a resolution of 1.8 {angstrom}. The Giardia 15.5kD protein exhibits the typical {alpha}-{beta}-{alpha} sandwich fold exhibited by both archaeal L7Ae and eukaryotic 15.5kD proteins. Characteristic of eukaryotic homologues, the Giardia 15.5kD protein binds the K-turn motif but not the variant K-loop motif. The highly conserved residues of loop 9, critical for RNA binding, also exhibit conformations similar to those of the human 15.5kD protein when bound to the K-turn motif. However, comparative sequence analysis indicated a distinct evolutionary position between Archaea and Eukarya. Indeed, assessment of the Giardia 15.5kD protein in denaturing experiments demonstrated an intermediate stability in protein structure when compared with that of the eukaryotic mouse 15.5kD and archaeal Methanocaldococcus jannaschii L7Ae proteins. Most notable was the ability of the Giardia 15.5kD protein to assemble in vitro a catalytically active chimeric box C/D RNP utilizing the archaeal M. jannaschii Nop56/58 and fibrillarin core proteins. In contrast, a catalytically competent chimeric RNP could not be assembled using the mouse 15.5kD protein. Collectively, these analyses suggest that the G. lamblia 15.5kD protein occupies a unique position in the evolution of this box C/D RNP core protein retaining structural and functional features characteristic of both archaeal L7Ae and higher eukaryotic 15.5kD homologues.

  15. Development of coccolithophore-based transfer functions in the Western Mediterranean Sea: a sea surface salinity reconstruction for the last 15.5 kyr

    NASA Astrophysics Data System (ADS)

    Ausín, B.; Hernández-Almeida, I.; Flores, J.-A.; Sierro, F.-J.; Grosjean, M.; Francés, G.; Alonso, B.

    2015-08-01

    A new dataset of 88 marine surface sediment samples and related oceanic environmental variables (temperature, salinity, chlorophyll a, oxygen, etc.) was studied to quantify the relationship between assemblages of coccolithophore species and modern environmental conditions in the Western Mediterranean Sea and the Atlantic Ocean, west of the Strait of Gibraltar. Multivariate statistical analyses revealed that coccolithophore species were primarily related to the sea surface salinity (SSS) gradient, which explains an independent and significant proportion of variance in the coccolithophore data. A quantitative coccolithophore-based transfer function to estimate SSS was developed using the Modern Analog Technique (MAT) and weighted-averaging partial-least square regression (WA-PLS). The bootstrapped regression coefficient (R2boot) was 0.85MAT and 0.80WA-PLS, with root-mean square error of prediction (RMSEP) of 0.29MAT and 0.30WA-PLS (psu). The resulting transfer function was applied to fossil coccolithophore assemblages in the highly resolved (∼ 65 yr) sediment core CEUTA10PC08 from the Alboran Sea (Western Mediterranean) in order to reconstruct SSS for the last 25 kyr. The reliability of the reconstruction was evaluated by assessing the degree of similarity between fossil and modern coccolithophore assemblage, and comparison of reconstruction with fossil ordination scores. Analogs were poor for the stadials associated with Heinrich Event 2 and 1 and part of the Last Glacial Maximum. Good analogs indicate more reliable reconstruction of the SSS for the last 15.5 kyr. During this period, several millennial and centennial SSS changes were observed and associated with variations in the Atlantic Water entering the Alboran Sea, sea-level oscillations, and arid or humid atmospheric conditions in the Western Mediterranean.

  16. Development of coccolithophore-based transfer functions in the western Mediterranean sea: a sea surface salinity reconstruction for the last 15.5 kyr

    NASA Astrophysics Data System (ADS)

    Ausín, B.; Hernández-Almeida, I.; Flores, J.-A.; Sierro, F.-J.; Grosjean, M.; Francés, G.; Alonso, B.

    2015-12-01

    A new data set of 88 marine surface sediment samples and related oceanic environmental variables (temperature, salinity, chlorophyll a, oxygen, etc.) was studied to quantify the relationship between assemblages of coccolithophore species and modern environmental conditions in the western Mediterranean Sea and the Atlantic Ocean, west of the Strait of Gibraltar. Multivariate statistical analyses revealed that coccolithophore species were primarily related to sea surface salinity (SSS), explaining an independent and significant proportion of variance in the coccolithophore data. A quantitative coccolithophore-based transfer function to estimate SSS was developed using the modern analog technique (MAT) and weighted-averaging partial least square regression (WA-PLS). The bootstrapped regression coefficient (R2boot) was 0.85MAT and 0.80WA-PLS, with a root-mean-square error of prediction (RMSEP) of 0.29MAT and 0.30WA-PLS (psu). The resulting transfer function was applied to fossil coccolithophore assemblages in the highly resolved (~ 65 years) sediment core CEUTA10PC08 from the Alboran Sea (western Mediterranean) in order to reconstruct SSS for the last 25 kyr. The reliability of the reconstruction was evaluated by assessing the degree of similarity between fossil and modern coccolithophore assemblages and by a comparison of reconstructions with fossil ordination scores. Analogs were poor for the stadials associated with Heinrich events 2 and 1 and part of the Last Glacial Maximum. Good analogs indicate a more reliable reconstruction of the SSS for the last 15.5 kyr. During this period, several millennial and centennial SSS changes were observed and associated with sea-level oscillations and variations in the Atlantic Water entering the Alboran.

  17. Esophageal pH monitoring

    MedlinePlus

    ... test can also be done during upper GI endoscopy by clipping a pH monitor to the lining of the esophagus. ... esophagitis : Barium swallow Esophagogastroduodenoscopy (also called upper GI endoscopy)

  18. Exercise and Pulmonary Hypertension (PH)

    MedlinePlus

    ... with their PH specialist prior to starting any exercise program. Current members: first time on our new PHPN/PHCR or Support Group ... Pulmonary Hypertension Association 801 Roeder Road, Ste. 1000 Silver Spring, ...

  19. Programmable pH buffers

    DOEpatents

    Gough, Dara Van; Huber, Dale L.; Bunker, Bruce C.; Roberts, Mark E.

    2017-01-24

    A programmable pH buffer comprises a copolymer that changes pK.sub.a at a lower critical solution temperature (LCST) in water. The copolymer comprises a thermally programmable polymer that undergoes a hydrophobic-to-hydrophilic phase change at the LCST and an electrolytic polymer that exhibits acid-base properties that are responsive to the phase change. The programmable pH buffer can be used to sequester CO.sub.2 into water.

  20. PhEDEx Data Service

    NASA Astrophysics Data System (ADS)

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

    2010-04-01

    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.

  1. A multi-method approach to the molecular diagnosis of overt and borderline 11p15.5 defects underlying Silver-Russell and Beckwith-Wiedemann syndromes.

    PubMed

    Russo, Silvia; Calzari, Luciano; Mussa, Alessandro; Mainini, Ester; Cassina, Matteo; Di Candia, Stefania; Clementi, Maurizio; Guzzetti, Sara; Tabano, Silvia; Miozzo, Monica; Sirchia, Silvia; Finelli, Palma; Prontera, Paolo; Maitz, Silvia; Sorge, Giovanni; Calcagno, Annalisa; Maghnie, Mohamad; Divizia, Maria Teresa; Melis, Daniela; Manfredini, Emanuela; Ferrero, Giovanni Battista; Pecile, Vanna; Larizza, Lidia

    2016-01-01

    Multiple (epi)genetic defects affecting the expression of the imprinted genes within the 11p15.5 chromosomal region underlie Silver-Russell (SRS) and Beckwith-Wiedemann (BWS) syndromes. The molecular diagnosis of these opposite growth disorders requires a multi-approach flowchart to disclose known primary and secondary (epi)genetic alterations; however, up to 20 and 30 % of clinically diagnosed BWS and SRS cases remain without molecular diagnosis. The complex structure of the 11p15 region with variable CpG methylation and low-rate mosaicism may account for missed diagnoses. Here, we demonstrate the relevance of complementary techniques for the assessment of different CpGs and the importance of testing multiple tissues to increase the SRS and BWS detection rate. Molecular testing of 147 and 450 clinically diagnosed SRS and BWS cases provided diagnosis in 34 SRS and 185 BWS patients, with 9 SRS and 21 BWS cases remaining undiagnosed and herein referred to as "borderline." A flowchart including complementary techniques and, when applicable, the analysis of buccal swabs, allowed confirmation of the molecular diagnosis in all borderline cases. Comparison of methylation levels by methylation-specific multiplex ligation-dependent probe amplification (MS-MLPA) in borderline and control cases defined an interval of H19/IGF2:IG-DMR loss of methylation that was distinct between "easy to diagnose" and "borderline" cases, which were characterized by values ≤mean -3 standard deviations (SDs) compared to controls. Values ≥mean +1 SD at H19/IGF2: IG-DMR were assigned to borderline hypermethylated BWS cases and those ≤mean -2 SD at KCNQ1OT1: TSS-DMR to hypomethylated BWS cases; these were supported by quantitative pyrosequencing or Southern blot analysis. Six BWS cases suspected to carry mosaic paternal uniparental disomy of chromosome 11 were confirmed by SNP array, which detected mosaicism till 10 %. Regarding the clinical presentation, borderline SRS were representative

  2. Hydrological constraints of paleo-Lake Suguta in the Northern Kenya Rift during the African Humid Period (15-5 ka BP)

    NASA Astrophysics Data System (ADS)

    Junginger, Annett; Trauth, Martin H.

    2013-12-01

    During the African Humid Period (AHP, 15-5 ka BP) an almost 300 m deep paleo-lake covering 2200 km2 developed in the Suguta Valley, in the Northern Kenya Rift. Data from lacustrine sediments and paleo-shorelines indicate that a large paleo-lake already existed by 13.9 ka BP, and record rapid water level fluctuations of up to 100 m within periods of 100 years or less, and a final lowstand at the end of the AHP (5 ka BP). We used a hydro-balance model to assess the abruptness of these water level fluctuations and identify their causes. We observed that fluctuations within the AHP were caused by abrupt changes in precipitation of 26-40%. Despite the absence of continuous lacustrine data documenting the onset of the AHP in the Suguta Valley, we conclude from the hydro-balance model that only an abrupt onset to the AHP, prior to 14.8 ka BP, could have led to high water levels recorded. The modeling results suggest that the sudden increase in rainfall was the direct consequence of an eastward migration of the Congo Air Boundary (CAB), caused by an enhanced atmospheric pressure gradient between East Africa and southern Asia during a northern hemisphere (NH) summer insolation maximum. In contrast, the end of the AHP must have been gradual despite an abrupt change in the source of precipitation when a decreasing pressure gradient between Asia and Africa prevented the CAB from reaching the study area. This abruptness was probably buffered by a contemporaneous change in precession producing an insolation maximum at the equator during September-October. This change would have meant that the only rain source was the Intertropical Convergence Zone (ITCZ), which would have carried a greater amount of moisture during the short rainy season thus slowing the fall in water level over a period of about 1000 years in association with the reduction in insolation. The results of this study provide an indication of the amount of time available for humans in north-eastern Africa to adapt

  3. pH Optrode Instrumentation

    NASA Technical Reports Server (NTRS)

    Tabacco, Mary Beth; Zhou, Quan

    1995-01-01

    pH-sensitive chromophoric reagents immobilized in porous optical fibers. Optoelectronic instrumentation system measures acidity or alkalinity of aqueous nutrient solution. Includes one or more optrodes, which are optical-fiber chemical sensors, in sense, analogous to electrodes but not subject to some of spurious effects distorting readings taken by pH electrodes. Concept of optrodes also described in "Ethylene-Vapor Optrodes" (KSC-11579). pH optrode sensor head, with lead-in and lead-out optical fibers, convenient for monitoring solutions located away from supporting electronic equipment.

  4. Making pH Tangible.

    ERIC Educational Resources Information Center

    McIntosh, Elizabeth; Moss, Robert

    1995-01-01

    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)

  5. Intragastric pH Monitoring,

    DTIC Science & Technology

    1993-10-01

    disposable sensor.. hnt Care 13. Peterson WL. GI bleeding. In: Sleisenger MH, Fordtran IS, Med 1988;14:232-5. ,. eds. Gastrointestinal disease: pathophysiology ... diagnosis and 27. Fimmel CL, Etienne A, Cilluffo T, et al. Long-term ambu- management, Vol I. 4th ed. Philadelphia: WB Saunders, latory gastric pH

  6. Making pH Tangible.

    ERIC Educational Resources Information Center

    McIntosh, Elizabeth; Moss, Robert

    1995-01-01

    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)

  7. Synthesis, structure, and magnetic properties of the novel sodium cobalt tellurate Na{sub 5}Co{sub 15.5}Te{sub 6}O{sub 36}

    SciTech Connect

    Shan, Yue Jin; Yoshioka, Yuta; Wakeshima, Makoto; Tezuka, Keitaro; Imoto, Hideo

    2014-03-15

    The novel single crystal oxide Na{sub 5}Co{sub 15.5}Te{sub 6}O{sub 36} had been successfully synthesized by a self-flux method. Na{sub 5}Co{sub 15.5}Te{sub 6}O{sub 36} crystallizes in hexagonal symmetry, space group P6{sub 3}/m (No.176), with lattice parameters a=9.359 (3) Å, c=9.096 (8) Å, and Z=1. The structure is composed of combining the edge-sharing chains of octahedra, [TeO{sub 6}]{sup 6−} and [Co(1)O{sub 6}]{sup 10−} with the face-sharing chains of triangular prisms, [Co(2)O{sub 6}]{sup 10−} and [Co(3)(Na(3))O{sub 6}]{sup 10−}. Sodium ions partially occupy hexagonal channels along the c-axis that are formed by the connection of the chains. The magnetic susceptibility data show a long-range antiferromagnetic ordering with a Neel temperature of 52 K along the c axis. At temperatures above 200 K, the susceptibility corrected for the diamagnetic contribution can be fit to the Curie–Weiss law for Co{sup 2+} (S=3/2). The anisotropic ferromagnetic and antiferromagnetic feature of Na{sub 5}Co{sub 15.5}Te{sub 6}O{sub 36} was obtained through field-dependent magnetization measurements at low temperature. The ferromagnetic and antiferromagnetic behaviors can be considered from the interactions between the Co ions in 1D zig-zag chains formed by sharing the edges of the Co(1)O{sub 6} octahedra, and the interactions between the interchain Co ions, respectively. -- Graphical abstract: The unit cell (a) and perspective view along [001] (b) of novel single crystal oxide, Na{sub 5}Co{sub 15.5}Te{sub 6}O{sub 36}. Highlights: • A single crystal of Na{sub 5}Co{sub 15.5}Te{sub 6}O{sub 36} has been synthesized by a self-flux method. • Na{sub 5}Co{sub 15.5}Te{sub 6}O{sub 36} crystallizes in hexagonal symmetry with a space group P6{sub 3}/m. • Na{sub 5}Co{sub 15.5}Te{sub 6}O{sub 36} has an antiferromagnetic ordering with a Neel temperature of 52 K. • Na{sub 5}Co{sub 15.5}Te{sub 6}O{sub 36} shows anisotropic ferro- and antiferromagnetism at low temperatures.

  8. The Methods Behind PH WINS

    PubMed Central

    Leider, Jonathon P.; Bharthapudi, Kiran; Pineau, Vicki; Liu, Lin; Harper, Elizabeth

    2015-01-01

    The Public Health Workforce Interests and Needs Survey (PH WINS) has yielded the first-ever nationally representative sample of state health agency central office employees. The survey represents a step forward in rigorous, systematic data collection to inform the public health workforce development agenda in the United States. PH WINS is a Web-based survey and was developed with guidance from a panel of public health workforce experts including practitioners and researchers. It draws heavily from existing and validated items and focuses on 4 main areas: workforce perceptions about training needs, workplace environment and job satisfaction, perceptions about national trends, and demographics. This article outlines the conceptualization, development, and implementation of PH WINS, as well as considerations and limitations. It also describes the creation of 2 new data sets that will be available in public use for public health officials and researchers—a nationally representative data set for permanently employed state health agency central office employees comprising over 10 000 responses, and a pilot data set with approximately 12 000 local and regional health department staff responses. PMID:26422490

  9. Alkaline pH sensor molecules.

    PubMed

    Murayama, Takashi; Maruyama, Ichiro N

    2015-11-01

    Animals can survive only within a narrow pH range. This requires continual monitoring of environmental and body-fluid pH. Although a variety of acidic pH sensor molecules have been reported, alkaline pH sensor function is not well understood. This Review describes neuronal alkaline pH sensors, grouped according to whether they monitor extracellular or intracellular alkaline pH. Extracellular sensors include the receptor-type guanylyl cyclase, the insulin receptor-related receptor, ligand-gated Cl- channels, connexin hemichannels, two-pore-domain K+ channels, and transient receptor potential (TRP) channels. Intracellular sensors include TRP channels and gap junction channels. Identification of molecular mechanisms underlying alkaline pH sensing is crucial for understanding how animals respond to environmental alkaline pH and how body-fluid pH is maintained within a narrow range.

  10. The fluorescence properties of the phenylated fullerenes C 70Ph 4, C 70Ph 6, C 70Ph 8, and C 70Ph 10 in room temperature solutions

    NASA Astrophysics Data System (ADS)

    Schwell, Martin; Gustavsson, Thomas; Marguet, Sylvie; Vaissière, Benoı̂t de La; Wachter, Norbert K.; Birkett, Paul R.; Mialocq, Jean-Claude; Leach, Sydney

    2001-12-01

    The emission and excitation spectra of four phenylated [70] fullerenes, C 70Ph 4, C 70Ph 6, C 70Ph 8, and C 70Ph 10 in cyclohexane and toluene solutions have been measured. The fluorescence spectra and related excited state properties are found to depend strongly on the number of attached phenyl groups, but with no systematic trends. Quantum yields and fluorescence lifetimes were measured for C 70Ph 6, C 70Ph 8, and C 70Ph 10, allowing the determination of S1 → S0 radiative transition rates kR. It is found that kR for C 70Ph 10 is about six times larger than for the other compounds. This is consistent with measured absorbtivities for these compounds. The particular character of C 70Ph 10 is also manifested by its higher intersystem crossing rate kISC.

  11. The pH of antiseptic cleansers

    PubMed Central

    Kulthanan, Kanokvalai; Varothai, Supenya; Nuchkull, Piyavadee

    2014-01-01

    Background Daily bathing with antiseptic cleansers are proposed by some physicians as an adjunctive management of atopic dermatitis (AD). As atopic skin is sensitive, selection of cleansing products becomes a topic of concern. Objective Our purpose is to evaluate the pH of various antiseptic body cleansers to give an overview for recommendation to patients with AD. Methods Commonly bar and liquid cleansers consisted of antiseptic agents were measured for pH using pH meter and pH-indicator strips. For comparison, mild cleansers and general body cleansers were also measured. Results All cleansing bars had pH 9.8-11.3 except syndet bar that had neutral pH. For liquid cleansers, three cleansing agents had pH close to pH of normal skin, one of antiseptic cleansers, one of mild cleansers and another one of general cleansers. The rest of antiseptic cleansers had pH 8.9-9.6 while mild cleansers had pH 6.9-7.5. Syndet liquid had pH 7 and general liquid cleansers had pH 9.6. Conclusion The pH of cleanser depends on composition of that cleanser. Adding antiseptic agents are not the only factor determining variation of pH. Moreover, benefit of antiseptic properties should be considered especially in cases of infected skin lesions in the selection of proper cleansers for patients with AD. PMID:24527408

  12. Acid loading test (pH)

    MedlinePlus

    ... this page: //medlineplus.gov/ency/article/003615.htm Acid loading test (pH) To use the sharing features on this page, please enable JavaScript. The acid loading test (pH) measures the ability of the ...

  13. Coping with PH over the Long Term

    MedlinePlus

    ... Newly Diagnosed Parents of Pediatric Patients PH Plus Social Media Specialty Pharmacy suPer Heroes Support Group Leaders Transplant ... Newly Diagnosed Parents of Pediatric Patients PH Plus Social Media Specialty Pharmacy suPer Heroes Support Group Leaders Transplant ...

  14. Media composition: pH and buffers.

    PubMed

    Swain, Jason E

    2012-01-01

    The proper pH of media is a crucial parameter for optimizing efficacy of gamete and embryo culture. Selecting the right media pH and stabilizing this pH are important variables in minimizing intracellular stress and optimizing development. Regulation of intracellular (pHi) and extracellular pH (pHe) is discussed, as well as methods to prevent harmful pHe oscillations. Furthermore, proper approaches to ensure accurate measurement of media pHe are described.

  15. Yes, we need PhD immunologists!

    PubMed

    Bishop, Gail A

    2015-05-01

    Constrained research funding prompts some to advocate training fewer PhDs. However, PhD immunologists are critically needed for future health challenges. Rather than discouraging promising young scientists from pursuing doctorates, we should ensure that such training is relevant to many different career possibilities to which PhD immunologists can make valuable contributions. Copyright © 2015. Published by Elsevier Ltd.

  16. 46 CFR 151.15-5 - Venting.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...) Pressure-vacuum venting. A normally closed venting system fitted with a device to automatically limit the pressure or vacuum in the tank to design limits. Pressure-vacuum relief valves shall comply with the... devices in accordance with the requirements of § 54.15-13 of this chapter. (2) When a...

  17. 46 CFR 194.15-5 - Ventilation.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... CONTROL OF EXPLOSIVES AND OTHER HAZARDOUS MATERIALS Chemistry Laboratory and Scientific Laboratory § 194... be equipped with acceptable flame screens. (b) Chemical laboratories shall be equipped with power...) Ventilation of air conditioning systems serving the chemical laboratory shall be designed so that air cannot...

  18. 7 CFR 15.5 - Compliance.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... complying with the regulations in this part. In the case in which a primary recipient extends Federal... to the primary recipient as may be necessary to enable the primary recipient to carry out its... racial and ethnic data showing the extent to which members of minority groups are beneficiaries of...

  19. 46 CFR 196.15-5 - Drafts.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... of the water in which the vessel is then floating. (1) When an allowance for draft is made for density of the water in which the vessel is floating, this density is to be noted in the official logbook. ...

  20. 46 CFR 196.15-5 - Drafts.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... of the water in which the vessel is then floating. (1) When an allowance for draft is made for density of the water in which the vessel is floating, this density is to be noted in the official logbook....

  1. 46 CFR 196.15-5 - Drafts.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... of the water in which the vessel is then floating. (1) When an allowance for draft is made for density of the water in which the vessel is floating, this density is to be noted in the official logbook....

  2. 46 CFR 196.15-5 - Drafts.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... of the water in which the vessel is then floating. (1) When an allowance for draft is made for density of the water in which the vessel is floating, this density is to be noted in the official logbook....

  3. 46 CFR 151.15-5 - Venting.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... pipe losses and flame screen, where used) to the movement of liquid or vapor to or from the cargo tank... be less than the total cross-sectional area of the filling pipe or pipes. Ullage openings may be... lines except that a float check valve may be installed so as to exclude the entry of water into the tank...

  4. 46 CFR 151.15-5 - Venting.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... pipe losses and flame screen, where used) to the movement of liquid or vapor to or from the cargo tank... be less than the total cross-sectional area of the filling pipe or pipes. Ullage openings may be... lines except that a float check valve may be installed so as to exclude the entry of water into the tank...

  5. 46 CFR 151.15-5 - Venting.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... pipe losses and flame screen, where used) to the movement of liquid or vapor to or from the cargo tank... be less than the total cross-sectional area of the filling pipe or pipes. Ullage openings may be... lines except that a float check valve may be installed so as to exclude the entry of water into the tank...

  6. Functional photoacoustic microscopy of pH

    NASA Astrophysics Data System (ADS)

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

    2012-02-01

    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.

  7. pH Meter probe assembly

    DOEpatents

    Hale, Charles J.

    1983-01-01

    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.

  8. pH Meter probe assembly

    DOEpatents

    Hale, C.J.

    1983-11-15

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

  9. Improved reliability of pH measurements.

    PubMed

    Spitzer, Petra; Werner, Barbara

    2002-11-01

    Measurements of pH are performed on a large scale at laboratory level, and in industry. To meet the quality-control requirements and other technical specifications there is a need for traceability in measurement results. The prerequisite for the international acceptance of analytical data is reliability. To measure means to compare. Comparability entails use of recognised references to which the standard buffer solutions used for calibration of pH meter-electrode assemblies can be traced. The new recommendation on the measurement of pH recently published as a provisional document by the International Union on Pure and Applied Chemistry (IUPAC) enables traceability for measured pH values to a conventional reference frame which is recognised world-wide. The primary method for pH will be described. If analytical data are to be accepted internationally it is necessary to demonstrate the equivalence of the national traceability structures, including national measurement standards. For the first time key comparisons for pH have been performed by the Consultative Committee for Amount of Substance (CCQM, set up by the International Bureau of Weights and Measures, BIPM) to assess the equivalence of the national measurement procedures used to determine the pH of primary standard buffer solutions. The results of the first key comparison on pH CCQM-K9, and other international initiatives to improve the consistency of the results of measurement for pH, are reported.

  10. Middle School and pH?

    ERIC Educational Resources Information Center

    Herricks, Susan

    2007-01-01

    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…

  11. pH. Agricultural Lesson Plans.

    ERIC Educational Resources Information Center

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

    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…

  12. PER PhDs & Bachelor's Degrees

    ERIC Educational Resources Information Center

    White, Susan C.

    2017-01-01

    Recently, the editor remarked to me that physics departments that offered a PhD with a specialization in Physics Education Research (PER) seemed to graduate more bachelor's degree recipients than those physics PhD departments that did not have the specialization. I was not convinced. That led to quite a bit of discussion between us. He compiled a…

  13. The PH.D. and the Profession.

    ERIC Educational Resources Information Center

    Beringause, Arthur

    The present status of the Ph.D. in English is briefly discussed. Don Cameron Allen's "The Ph.D. in English and American Literature" is praised as a much-needed study which can help the English profession revitalize graduate programs. Several of Allen's conclusions are briefly summarized. (BN)

  14. pH [Measure of Acidity].

    ERIC Educational Resources Information Center

    Henderson, Paula

    This autoinstructional program deals with the study of the pH of given substances by using litmus and hydrion papers. It is a learning activity directed toward low achievers involved in the study of biology at the secondary school level. The time suggested for the unit is 25-30 minutes (plus additional time for further pH testing). The equipment…

  15. Middle School and pH?

    ERIC Educational Resources Information Center

    Herricks, Susan

    2007-01-01

    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…

  16. Inexpensive and Disposable pH Electrodes

    ERIC Educational Resources Information Center

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

    2010-01-01

    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…

  17. Response to the "Responsive PhD"

    ERIC Educational Resources Information Center

    Huyssen, David

    2007-01-01

    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…

  18. Inexpensive and Disposable pH Electrodes

    ERIC Educational Resources Information Center

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

    2010-01-01

    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…

  19. Endoscopic sensing of alveolar pH

    PubMed Central

    Choudhury, D.; Tanner, M. G.; McAughtrie, S.; Yu, F.; Mills, B.; Choudhary, T. R.; Seth, S.; Craven, T. H.; Stone, J. M.; Mati, I. K.; Campbell, C. J.; Bradley, M.; Williams, C. K. I.; Dhaliwal, K.; Birks, T. A.; Thomson, R. R.

    2016-01-01

    Previously unobtainable measurements of alveolar pH were obtained using an endoscope-deployable optrode. The pH sensing was achieved using functionalized gold nanoshell sensors and surface enhanced Raman spectroscopy (SERS). The optrode consisted of an asymmetric dual-core optical fiber designed for spatially separating the optical pump delivery and signal collection, in order to circumvent the unwanted Raman signal generated within the fiber. Using this approach, we demonstrate a ~100-fold increase in SERS signal-to-fiber background ratio, and demonstrate multiple site pH sensing with a measurement accuracy of ± 0.07 pH units in the respiratory acini of an ex vivo ovine lung model. We also demonstrate that alveolar pH changes in response to ventilation. PMID:28101415

  20. Endoscopic sensing of alveolar pH.

    PubMed

    Choudhury, D; Tanner, M G; McAughtrie, S; Yu, F; Mills, B; Choudhary, T R; Seth, S; Craven, T H; Stone, J M; Mati, I K; Campbell, C J; Bradley, M; Williams, C K I; Dhaliwal, K; Birks, T A; Thomson, R R

    2017-01-01

    Previously unobtainable measurements of alveolar pH were obtained using an endoscope-deployable optrode. The pH sensing was achieved using functionalized gold nanoshell sensors and surface enhanced Raman spectroscopy (SERS). The optrode consisted of an asymmetric dual-core optical fiber designed for spatially separating the optical pump delivery and signal collection, in order to circumvent the unwanted Raman signal generated within the fiber. Using this approach, we demonstrate a ~100-fold increase in SERS signal-to-fiber background ratio, and demonstrate multiple site pH sensing with a measurement accuracy of ± 0.07 pH units in the respiratory acini of an ex vivo ovine lung model. We also demonstrate that alveolar pH changes in response to ventilation.

  1. Determination Of Ph Including Hemoglobin Correction

    DOEpatents

    Maynard, John D.; Hendee, Shonn P.; Rohrscheib, Mark R.; Nunez, David; Alam, M. Kathleen; Franke, James E.; Kemeny, Gabor J.

    2005-09-13

    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.

  2. Development of Hybrid pH sensor for long-term seawater pH monitoring.

    NASA Astrophysics Data System (ADS)

    Nakano, Y.; Egashira, T.; Miwa, T.; Kimoto, H.

    2016-02-01

    We have been developing the in situ pH sensor (Hybrid pH sensor: HpHS) for the long-term seawater pH monitoring. We are planning to provide the HpHS for researchers and environmental consultants for observation of the CCS (Carbon dioxide Capture and Storage) monitoring system, the coastal environment monitoring system (e.g. Blue Carbon) and ocean acidification. The HpHS has two types of pH sensors (i.e. potentiometric pH sensor and spectrophotometric pH sensor). The spectrophotometric pH sensor can measure pH correctly and stably, however it needs large power consumption and a lot of reagents in a long period of observation. The pH sensor used m-cresol purple (mCP) as an indicator of pH (Clayton and Byrne, 1993 and Liu et al., 2011). We can choose both coefficients before deployment. On the other hand, although the potentiometric pH sensor is low power consumption and high-speed response (within 10 seconds), drifts in the pH of the potentiometric measurements may possibly occur for a long-term observation. The HpHS can measure in situ pH correctly and stably combining advantage of both pH sensors. The HpHS consists of an aluminum pressure housing with optical cell (main unit) and an aluminum silicon-oil filled, pressure-compensated vessel containing pumps and valves (diaphragm pump and valve unit) and pressure-compensated reagents bags (pH indicator, pure water and Tris buffer or certified reference material: CRM) with an ability to resist water pressure to 3000m depth. The main unit holds system control boards, pump drivers, data storage (micro SD card), LED right source, photodiode, optical cell and pressure proof windows. The HpHS also has an aluminum pressure housing that holds a rechargeable lithium-ion battery or a lithium battery for the power supply (DC 24 V). The HpHS is correcting the value of the potentiometric pH sensor (measuring frequently) by the value of the spectrophotometric pH sensor (measuring less frequently). It is possible to calibrate in

  3. Comparison of two pH meters used for skin surface pH measurement: the pH meter 'pH900' from Courage & Khazaka versus the pH meter '1140' from Mettler Toledo.

    PubMed

    Ehlers, C; Ivens, U I; Møller, M L; Senderovitz, T; Serup, J

    2001-05-01

    Measurement of skin surface pH is used in clinical research to evaluate hazardous shifts in pH following external exposures and to evaluate the state of diseased skin with acute or chronic changes. It is therefore important to measure skin surface pH as precisely as possible. The aim of this study was to compare two commercially available pH meters used for skin surface pH measurement, to reveal differences between them in measured skin pH on the forearm. The first pH meter (pH900) had a pointed electrode and a stabilisation period of 3 s. The second pH meter (pH meter 1140) had a circular electrode and no fixed stabilisation period. Twelve healthy subjects (6 male and 6 female Caucasians) entered the study. The pH measurements were performed once an hour from 8 a.m. to 3 p.m. on both forearms in five areas from the elbow to the "wristwatch" zone. In each area, three measurements were performed next to each other with both pH meters (15 measurements per arm per hour per pH meter). The pH900 has a higher measuring level and a higher variation than the pH meter 1140. A skin surface pH meter with a circular electrode and with no fixed stabilisation period is preferable. It is recommended that the pH meter be allowed to stabilise for at least 7 s before the result is read.

  4. Exhaled breath condensate pH assays.

    PubMed

    Davis, Michael D; Hunt, John

    2012-08-01

    Airway pH is central to the physiologic function and cellular biology of the airway. The causes of airway acidification include (1) hypopharyngeal gastric acid reflux with or without aspiration through the vocal cords, (2) inhalation of acid fog or gas (such as chlorine), and (3) intrinsic airway acidification caused by altered airway pH homeostasis in infectious and inflammatory disease processes. The recognition that relevant airway pH deviations occur in lung diseases is opening doors to new simple and inexpensive therapies. This recognition has resulted partly from the ability to use exhaled breath condensate as a window on airway acid-base balance.

  5. Colorimetric Determination of pH.

    ERIC Educational Resources Information Center

    Tucker, Sheryl; And Others

    1989-01-01

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

  6. Effect of two mouthwashes on salivary ph.

    PubMed

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

    2014-01-01

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

  7. [Power in the PhD programme].

    PubMed

    Tijdink, J K

    2016-01-01

    This article describes the role of power in the world of biomedical research. On the basis of some examples, I intend to demonstrate the influence of power, or its misuse, on PhD students and supervisors, and how this may have a negative effect on the research of PhD students. I will then outline how the biomedical research field can prevent these practices, and how it can create a better and more inspiring atmosphere for young, enthusiastic and talented researchers.

  8. Clinical utility of pH paper versus pH meter in the measurement of critical gastric pH in stress ulcer prophylaxis.

    PubMed

    Bradley, J S; Phillips, J O; Cavanaugh, J E; Metzler, M H

    1998-11-01

    To evaluate the clinical utility of measuring gastric pH with a pH meter vs. pH paper in critical care patients. Prospective comparison of gastric pH measurements, using both pH meter and pH paper. Surgical intensive care unit (ICU) at a rural Midwestern university medical center. Fifty-one patients who received therapy for prophylaxis of stress ulcers in the surgical ICU. Therapy for stress ulcer prophylaxis was monitored. The pH of 985 gastric samples, taken from 51 patients, was measured with both pH meter and pH paper. The pH meter and pH paper measures demonstrated a concordance correlation coefficient of .896. The mean difference between the two measures (pH paper - pH meter) was estimated to be between -0.4 and 1.4, suggesting a positive bias for the paper. The prevalence of events representing clinically relevant differences between the pH meter and pH paper in the measurement of the same gastric sample was calculated. The frequency with which each of the events occurred consecutively (or, in one case, two nearly consecutive events on the same day) was also calculated. Bias in a clinically relevant range was estimated. A set of "probability profiles" was constructed. A hand-held pH meter and pH paper are not interchangeable measures of gastric pH. The pH paper exhibits an appreciable positive bias compared with a hand-held pH meter in the clinically relevant range of 2 to 6. More research is needed to determine if that bias affects treatment outcomes. We recommend the use of a pH meter for patients who demonstrate pH readings of < or = 4, consecutive with readings of < or = 5.

  9. Eukaryotic diversity at pH extremes

    PubMed Central

    Amaral-Zettler, Linda A.

    2013-01-01

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

  10. Eukaryotic diversity at pH extremes.

    PubMed

    Amaral-Zettler, Linda A

    2012-01-01

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

  11. MRF with adjustable pH

    NASA Astrophysics Data System (ADS)

    Jacobs, Stephen D.

    2011-10-01

    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.

  12. pH. Training Module 5.305.2.77.

    ERIC Educational Resources Information Center

    Kirkwood Community Coll., Cedar Rapids, IA.

    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…

  13. A Nanocrystal-based Ratiometric pH Sensor for Natural pH Ranges

    PubMed Central

    Somers, Rebecca C.; Lanning, Ryan M.; Snee, Preston T.; Greytak, Andrew B.; Jain, Rakesh K.

    2014-01-01

    Summary A ratiometric fluorescent pH sensor based on CdSe/CdZnS nanocrystal quantum dots (NCs) has been designed for biological pH ranges. The construct is formed from the conjugation of a pH dye (SNARF) to NCs coated with a poly(amido amine) (PAMAM) dendrimer. The sensor exhibits a well–resolved ratio response at pH values between 6 and 8 under linear or two–photon excitation, and in the presence of a 4% bovine serum albumin (BSA) solution. PMID:26413260

  14. A Nanocrystal-based Ratiometric pH Sensor for Natural pH Ranges.

    PubMed

    Somers, Rebecca C; Lanning, Ryan M; Snee, Preston T; Greytak, Andrew B; Jain, Rakesh K; Bawendi, Moungi G; Nocera, Daniel G

    A ratiometric fluorescent pH sensor based on CdSe/CdZnS nanocrystal quantum dots (NCs) has been designed for biological pH ranges. The construct is formed from the conjugation of a pH dye (SNARF) to NCs coated with a poly(amido amine) (PAMAM) dendrimer. The sensor exhibits a well-resolved ratio response at pH values between 6 and 8 under linear or two-photon excitation, and in the presence of a 4% bovine serum albumin (BSA) solution.

  15. MD-PhDs in dermatology.

    PubMed

    Prystowsky, J H

    1992-05-01

    A national survey was conducted to explore ways in which MD-PhDs in dermatology balance their research and clinical interests and the factors that influenced their career decisions. A questionnaire was mailed to all MD-PhDs who were affiliated with dermatology training programs as determined by a preliminary study. The survey consisted of a questionnaire about research background, career pathway, attitudes about personal and professional issues, and influence of residency training program on career decision making. From 60 MD-PhD dermatologists surveyed, 43 (72%) completed questionnaires. Eighty percent of the respondents (34 of 43) held positions in academic medicine; 76% entered dermatology with the intent to pursue academic medicine. Almost all (93%) held academic positions immediately after residency; 50% held positions with the title of assistant professor or higher as their first postresidency employment. Only 26% of the respondents received funding for their MD-PhD through the federally funded Medical Scientist Training Program. Fifty percent of the respondents completed their training with loans. Despite the long period of training and expense required for the dual career, a high percentage (80%) stayed in academic dermatology suggesting that they are an important source for supplying physician-scientists to the field of dermatology. The ability to limit patient care responsibilities and maintain protected time for research may be a factor responsible for the high percentage of MD-PhDs that stay in academic dermatology.

  16. Imaging pH and Metastasis

    PubMed Central

    Hashim, Arig Ibrahim; Zhang, Xiaomeng; Wojtkowiakk, Jonathan W.; Gillies, Robert J.

    2013-01-01

    Metastasis is a multistep process that culminates in the spread of cells from a primary tumor to a distant site or organs. For tumor cells to be able to metastasize, they have to locally invade through basement membrane into the lymphatic and the blood vasculatures. Eventually they extravasate from the blood and colonize in the secondary organ. This process involves multiple interactions between the tumor cells and their microenvironments. The microenvironment surrounding tumors has a significant impact on tumor development and progression. A key factor in the microenvironment is an acidic pH. The extracellular pH of solid tumors is more acidic in comparison to normal tissue as a consequence of high glycolysis and poor perfusion. It plays an important role in almost all steps of metastasis. The past decades have seen development of technologies to non-invasively measure intra- and/or extracellular pH. Most successful measurements are MR-based, and sensitivity and accuracy have dramatically improved. Quantitatively imaging the distribution of acidity helps us understand the role of the tumor microenvironment in cancer progression. This review discusses different MR methods in measuring tumor pH along with emphasizing the importance of extracelluar tumor low pH on different steps of metastasis; more specifically focusing on Epithelial to Mesenchymal transition (EMT), and anti cancer immunity. PMID:21387439

  17. Assignment of the human fast skeletal troponin T gene (TNNT3) to chromosome 11p15.5: Evidence for the presence of 11pter in a monochromosome 9 somatic cell hybrid in NIGMS mapping panel 2

    SciTech Connect

    Mao, Chengjian; Jha, P.K.; Sarkar, S.

    1996-02-01

    Human fast skeletal troponin T (TnT{sub f}), the tropomyosin binding component of the multisubunit troponin complex, plays an important role in the Ca{sup 2+} regulation of striated muscle contraction. Specific primers designed from the 3{prime} end of human TnT{sub f} cDNA were used to amplify an intronic region by polymerase chain reaction (PCR). This TnT{sub f}-specific PCR product was detected from two somatic cell hybrids containing human chromosomes 9 and 11, respectively, in NIGMS mapping panel 2. However, further studies with other somatic hybrid cell lines (Bios Laboratory) localized the TnT{sub f} genomic probe generated by extended PCR, showing the sublocalization of the gene to band p15.5 on chromosome 11. This locus is of specific interest, as Beckwith-Wiedemann syndrome and various childhood and adult tumor-related abnormalities have been mapped to this region. The study also indicates the presence of an 11pter region in the NIGMS cell hybrid GM10611, which has previously been reported to contain only human chromosome 9. 11 refs., 2 figs.

  18. Element-specific electronic structure and magnetic properties of an epitaxial Ni51.6Mn32.9Sn15.5 thin film at the austenite-martensite transition

    NASA Astrophysics Data System (ADS)

    Krumme, B.; Auge, A.; Herper, H. C.; Opahle, I.; Klar, D.; Teichert, N.; Joly, L.; Ohresser, P.; Landers, J.; Kappler, J. P.; Entel, P.; Hütten, A.; Wende, H.

    2015-06-01

    An austenite-martensite transition was observed in a 100-nm-thick Ni51.6Mn32.9Sn15.5 film by temperature-dependent resistivity and magnetization measurements, revealing a martensite starting temperature of MS≈260 K. The influence of the structural phase transition on the electronic structure and the magnetic properties was studied element specifically employing temperature-dependent x-ray-absorption spectroscopy and x-ray magnetic circular dichroism. In addition, density functional theory calculations have been performed to study the electronic and magnetic properties of both phases. It is shown that off-stoichiometric Ni-Mn-Sn alloys can exhibit a substantial magnetocrystalline anisotropy energy in the martensite phase. For Mn a change of the electronic structure and a strong increase of the ratio of orbital to spin magnetic moment ml/mS can be observed, whereas for Ni nearly no changes occur. Applying an external magnetic field of B =3 T reverses the change of the electronic structure of Mn and reduces the ratio of ml/mS from 13.5 to ≈1 % indicating a field-induced reverse martensitic transition.

  19. Thermally programmable pH buffers.

    PubMed

    Van Gough, Dara; Bunker, Bruce C; Roberts, Mark E; Huber, Dale L; Zarick, Holly F; Austin, Mariah J; Wheeler, Jill S; Moore, Diana; Spoerke, Erik D

    2012-11-01

    Many reactions in both chemistry and biology rely on the ability to precisely control and fix the solution concentrations of either protons or hydroxide ions. In this report, we describe the behavior of thermally programmable pH buffer systems based on the copolymerization of varying amounts of acrylic acid (AA) groups into N-isopropylacrylamide polymers. Because the copolymers undergo phase transitions upon heating and cooling, the local environment around the AA groups can be reversibly switched between hydrophobic and hydrophilic states affecting the ionization behavior of the acids. Results show that moderate temperature variations can be used to change the solution pH by two units. However, results also indicate that the nature of the transition and its impact on the pH values are highly dependent on the AA content and the degree of neutralization.

  20. Fiber-Optic pH Sensor

    NASA Astrophysics Data System (ADS)

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

    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.

  1. pH and Titratable Acidity

    NASA Astrophysics Data System (ADS)

    Sadler, George D.; Murphy, Patricia A.

    There are two interrelated concepts in food analysis that deal with acidity: pH and titratable acidity. Each of these quantities is analytically determined in separate ways and each has its own particular impact on food quality. Titratable acidity deals with measurement of the total acid concentration contained within a food (also called total acidity). This quantity is determined by exhaustive titration of intrinsic acids with a standard base. Titratable acidity is a better predictor of acid's impact on flavor than pH.

  2. Differential genotoxicity of diphenyl diselenide (PhSe)2 and diphenyl ditelluride (PhTe)2.

    PubMed

    Meinerz, Daiane Francine; Allebrandt, Josiane; Mariano, Douglas O C; Waczuk, Emily P; Soares, Felix Antunes; Hassan, Waseem; Rocha, João Batista T

    2014-01-01

    Organoselenium compounds have been pointed out as therapeutic agents. In contrast, the potential therapeutic aspects of tellurides have not yet been demonstrated. The present study evaluated the comparative toxicological effects of diphenyl diselenide (PhSe)2 and diphenyl ditelluride (PhTe)2 in mice after in vivo administration. Genotoxicity (as determined by comet assay) and mutagenicicity were used as end-points of toxicity. Subcutaneous administration of high doses of (PhSe)2 or (PhTe)2 (500 µmol/kg) caused distinct genotoxicity in mice. (PhSe)2 significantly decreased the DNA damage index after 48 and 96 h of its injection (p < 0.05). In contrast, (PhTe) caused a significant increase in DNA damage (p < 0.05) after 48 and 96 h of intoxication. (PhSe)2 did not cause mutagenicity but (PhTe)2 increased the micronuclei frequency, indicating its mutagenic potential. The present study demonstrated that acute in vivo exposure to ditelluride caused genotoxicity in mice, which may be associated with pro-oxidant effects of diphenyl ditelluride. In addition, the use of this compound and possibly other related tellurides must be carefully controlled.

  3. Evaluation of fluorimetric pH sensors for bioprocess monitoring at low pH.

    PubMed

    Janzen, Nils H; Schmidt, Michael; Krause, Christian; Weuster-Botz, Dirk

    2015-09-01

    Optical chemical sensors are the standard for pH monitoring in small-scale bioreactors such as microtiter plates, shaking flasks or other single-use bioreactors. The dynamic pH range of the so far commercially available fluorescent pH sensors applied in small-scale bioreactors is restricted to pH monitoring around neutral pH, although many fermentation processes are performed at pH < 6 on industrial scale. Thus, two new prototype acidic fluorescence pH sensors immobilized in single-use stirred-tank bioreactors, one with excitation at 470 nm and emission at 550 nm (sensor 470/550) and the other with excitation at 505 nm and emission at 600 nm (sensor 505/600), were characterized with respect to dynamic ranges and operational stability in representative fermentation media. Best resolution and dynamic range was observed with pH sensor 505/600 in mineral medium (dynamic range of 3.9 < pH < 7.2). Applying the same pH sensors to complex medium results in a drastic reduction of resolution and dynamic ranges. Yeast extract in complex medium was found to cause background fluorescence at the sensors' operating wavelength combinations. Optical isolation of the sensor by adding a black colored polymer layer above the sensor spot and fixing an aperture made of adhesive photoresistant foil between the fluorescence reader and the transparent bottom of the polystyrene reactors enabled full re-establishment of the sensor's characteristics. Reliability and operational stability of sensor 505/600 was shown by online pH monitoring (4.5 < pH < 5.8) of parallel anaerobic batch fermentations of Clostridium acetobutylicum for the production of acetone, butanol and ethanol (ABE) with offline pH measurements with a standard glass electrode as reference.

  4. Optoelectronic pH Meter: Further Details

    NASA Technical Reports Server (NTRS)

    Jeevarajan, Antony S.; Anderson, Mejody M.; Macatangay, Ariel V.

    2009-01-01

    A collection of documents provides further detailed information about an optoelectronic instrument that measures the pH of an aqueous cell-culture medium to within 0.1 unit in the range from 6.5 to 7.5. The instrument at an earlier stage of development was reported in Optoelectronic Instrument Monitors pH in a Culture Medium (MSC-23107), NASA Tech Briefs, Vol. 28, No. 9 (September 2004), page 4a. To recapitulate: The instrument includes a quartz cuvette through which the medium flows as it is circulated through a bioreactor. The medium contains some phenol red, which is an organic pH-indicator dye. The cuvette sits between a light source and a photodetector. [The light source in the earlier version comprised red (625 nm) and green (558 nm) light-emitting diodes (LEDs); the light source in the present version comprises a single green- (560 nm)-or-red (623 nm) LED.] The red and green are repeatedly flashed in alternation. The responses of the photodiode to the green and red are processed electronically to obtain the ratio between the amounts of green and red light transmitted through the medium. The optical absorbance of the phenol red in the green light varies as a known function of pH. Hence, the pH of the medium can be calculated from the aforesaid ratio.

  5. Ph.D.'s and the Marketplace.

    ERIC Educational Resources Information Center

    Harvey, James

    Throughout the last decade, Ph.D. recipients were accustomed to a job market in which demand for their services far exceeded supply. During the same period, manpower experts predicted this situation would continue in the foreseeable future. However, when the 60's ended, the employment illusion had been rudely dispelled by frantic reports of a…

  6. The Economic Contribution of PhDs

    ERIC Educational Resources Information Center

    Casey, Bernard H.

    2009-01-01

    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…

  7. New Directions for the Ph.D.?

    ERIC Educational Resources Information Center

    Deener, David R.

    The award rate of doctorates has tripled since 1960 and the projections indicate that by 1980 the rate will be somewhere between 60 and 70,000. In recent years every facet of the PhD has come under attack. The degree will probably be reshaped from a standard of achievement and accomplishment to a standard of potential, from a demonstration of the…

  8. pH & Rate of Enzymatic Reactions.

    ERIC Educational Resources Information Center

    Clariana, Roy B.

    1991-01-01

    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…

  9. The closed eye environement: pH.

    PubMed

    Hill, R M; Carney, L G

    1976-11-01

    Earlier observations showed that unbuffered bathing media held by a closed chamber against the eye would become progressively more acid over a few minutes. Such shifts, however, when examined for the naturally closed eye, even for prolonged periods, were found to be within 1 pH unit of the open-eye measured average.

  10. Teaching Physics Using PhET Simulations

    ERIC Educational Resources Information Center

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

    2010-01-01

    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…

  11. First-Principles pH Theory

    NASA Astrophysics Data System (ADS)

    Kim, Yong-Hyun; Zhang, S. B.

    2006-03-01

    Despite being one of the most important macroscopic measures and a long history even before the quantum mechanics, the concept of pH has rarely been mentioned in microscopic theories, nor being incorporated computationally into first-principles theory of aqueous solutions. Here, we formulate a theory for the pH dependence of solution formation energy by introducing the proton chemical potential as the microscopic counterpart of pH in atomistic solution models. Within the theory, the general acid-base chemistry can be cast in a simple pictorial representation. We adopt density-functional molecular dynamics to demonstrate the usefulness of the method by studying a number of solution systems including water, small solute molecules such as NH3 and HCOOH, and more complex amino acids with several functional groups. For pure water, we calculated the auto- ionization constant to be 13.2 with a 95 % accuracy. For other solutes, the calculated dissociation constants, i.e., the so- called pKa, are also in reasonable agreement with experiments. Our first-principles pH theory can be readily applied to broad solution chemistry problems such as redox reactions.

  12. The Economic Contribution of PhDs

    ERIC Educational Resources Information Center

    Casey, Bernard H.

    2009-01-01

    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…

  13. The Ph.D. Value Proposition

    ERIC Educational Resources Information Center

    Cooper, Kenneth J.

    2012-01-01

    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…

  14. Monitoring fetal pH by telemetry

    NASA Technical Reports Server (NTRS)

    Blum, A.; Donahoe, T.; Jhabvala, M. D.; Ryan, W.

    1980-01-01

    Telemetry unit has been developed for possible use in measuring scalp-tissue pH and heart rate of unborn infant. Unit radius data to receiver as much as 50 ft. away. Application exists during hours just prior to childbirth to give warning of problems that might require cesarean delivery.

  15. Profile of Ph.Ds in Canada.

    ERIC Educational Resources Information Center

    von Zur-Muehlen, Max

    A profile of the socio-economic characteristics of the permanent residents of Canada holding an earned doctorate is presented. In 1973, there were 27,410 Canadian residents who had obtained an earned doctorate. (Holders of such professional doctoral degrees as Doctor of Medicine are excluded from this study.) Only 9 percent of the Ph.Ds were…

  16. What My Ph.D. Taught Me

    ERIC Educational Resources Information Center

    Levenstein, Jessica

    2013-01-01

    The author started in the Ph.D. program in comparative literature at Princeton in 1992, a year after she graduated from college. She fell in love with mythology and the classical traditions and find herself teaching literature. In the remainder of her time at Princeton, she precepted for four or five more classes, got the chance to join the…

  17. What My Ph.D. Taught Me

    ERIC Educational Resources Information Center

    Levenstein, Jessica

    2013-01-01

    The author started in the Ph.D. program in comparative literature at Princeton in 1992, a year after she graduated from college. She fell in love with mythology and the classical traditions and find herself teaching literature. In the remainder of her time at Princeton, she precepted for four or five more classes, got the chance to join the…

  18. Teaching Physics Using PhET Simulations

    ERIC Educational Resources Information Center

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

    2010-01-01

    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…

  19. The Ph.D. Value Proposition

    ERIC Educational Resources Information Center

    Cooper, Kenneth J.

    2012-01-01

    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…

  20. Development of sulfonamide AKT PH domain inhibitors.

    PubMed

    Ahad, Ali Md; Zuohe, Song; Du-Cuny, Lei; Moses, Sylvestor A; Zhou, Li Li; Zhang, Shuxing; Powis, Garth; Meuillet, Emmanuelle J; Mash, Eugene A

    2011-03-15

    Disruption of the phosphatidylinositol 3-kinase/AKT signaling pathway can lead to apoptosis in cancer cells. Previously we identified a lead sulfonamide that selectively bound to the pleckstrin homology (PH) domain of AKT and induced apoptosis when present at low micromolar concentrations. To examine the effects of structural modification, a set of sulfonamides related to the lead compound was designed, synthesized, and tested for binding to the expressed PH domain of AKT using a surface plasmon resonance-based competitive binding assay. Cellular activity was determined by means of an assay for pAKT production and a cell killing assay using BxPC-3 cells. The most active compounds in the set are lipophilic and possess an aliphatic chain of the proper length. Results were interpreted with the aid of computational modeling. This paper represents the first structure-activity relationship (SAR) study of a large family of AKT PH domain inhibitors. Information obtained will be used in the design of the next generation of inhibitors of AKT PH domain function.

  1. pH & Rate of Enzymatic Reactions.

    ERIC Educational Resources Information Center

    Clariana, Roy B.

    1991-01-01

    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…

  2. Monitoring fetal pH by telemetry

    NASA Technical Reports Server (NTRS)

    Blum, A.; Donahoe, T.; Jhabvala, M. D.; Ryan, W.

    1980-01-01

    Telemetry unit has been developed for possible use in measuring scalp-tissue pH and heart rate of unborn infant. Unit radius data to receiver as much as 50 ft. away. Application exists during hours just prior to childbirth to give warning of problems that might require cesarean delivery.

  3. [A comparison of pH<4 and pH<5 as thresholds for 24-hour pH monitoring in the diagnosis of laryngopharyngeal reflux].

    PubMed

    Wang, J S; Li, J R

    2016-09-07

    Objective: To evaluate the consistency between 24-hour pH monitoring, reflux symptom index(RSI) and reflux finding score(RFS) when using pH<4 or pH<5 as threshold for 24-hour pH monitoring in the diagnosis of laryngopharyngeal reflux. Methods: Patients who presented with suspicious laryngopharyngeal reflux between February 2014 and December 2015 were included in this study. pH<4 and pH<5 reflux episodes, RSI and RFS were collected. The consistency between 24-hour pH monitoring and scale results were analyzed when pH<4 or pH<5 as threshold respectively. The sensitivity and specificity of 24-hour pH monitoring were calculated separately. Results: Median number(M[P25, P75, P95]) of reflux events were 0 [0, 3.0, 5.5] when using pH<4 as pathological threshold and 0 [0, 4.0, and 8.5] using pH<5 as pathological threshold. Laryngopharyngeal reflux was determined in 34.5% patients depending on 24-hour pH monitoring when pH<4 was used as threshold, chi-square revealed medium consistency (κ=0.483) between pH monitoring and scale result. If pH<5 was used as threshold, 41.8% patients were detected with laryngopharyngeal reflux, and the consistency of pH monitoring and scale result was medium(κ=0.540). With RSI and RFS for reference, the sensitivity and specificity of 24-hour pH monitoring were 54.7% and 93.4% respectively when pH<4 was used as threshold. If pH<5 was used as threshold, the sensitivity and specificity of 24-hour pH monitoring were 65.6% and 91.3% respectively. Conclusions: Compared with pH<4 as pathological threshold, the consistency of pH monitoring and scale results was a little better using pH<5 as pathological threshold.

  4. The effect of pH on growth of Clostridium botulinum type A and expression of bontA and botR during different growth stages.

    PubMed

    Li, Tao; Tian, Renmao; Cai, Kun; Wang, Qin; Chen, Fanghong; Fang, Huali; Luo, Sen; Li, Zhan; Wang, Dehui; Hou, Xiaojun; Wang, Hui

    2013-08-01

    In this study, the effects of pH on the growth, relative expressions of bontA and botR genes, and neurotoxin formation of foodborne pathogens Clostridium botulinum type A were systematically studied throughout its growth stage. As in the previous reports, no C. botulinum growth was observed at extremely acidic pH. However, the effect of alkaline pH on the growth and neurotoxin production of C. botulinum was first revealed in this study. The maximum growth rate at pH 9.0 was similar to that at other pH values, although the lag phase at pH 9.0 was 16 h longer than that at pH 8.0. The peak of bontA mRNA expression at pH 9.0 was only 15.5% compared with that at pH 7.0. However, the neurotoxin concentration quantified in the cultures did not differ significantly. BotR is a known regulatory protein of bontA. The quantitative relationship between bontA and botR at different growth stages was first determined in this study. The mRNA levels of bontA were found to be positively correlated with those of botR, and the ratio of the mRNA transcript varied with pH. All these findings provide important physiological information on C. botulinum and thereby contribute to the improvement of food safety.

  5. Relation between pH in the Trunk and Face: Truncal pH Can Be Easily Predicted from Facial pH.

    PubMed

    Kim, Sung Ae; Kim, Bo Ri; Chun, Mi Young; Youn, Sang Woong

    2016-04-01

    The clinical symptoms of facial and truncal acne differ. Skin surface acidity (pH), which is affected by sebum secretions, reflects the different clinical characteristics of the face and trunk. However, no studies have been conducted on truncal sebum production and skin pH. We evaluated the differences and relationship between pH values of the face and trunk. We also evaluated the relationship between pH and the quantity of sebum produced in the trunk. A total of 35 female patients clinically diagnosed with truncal acne were included. We measured pH on the face and truncal area using the Skin-pH-Meter PH 905®. We measured truncal sebum secretions using the Sebumeter SM 815®. Statistical analysis was performed to evaluate the correlations and differences between pH and sebum. Facial pH was significantly higher than chest and back pH values. The correlation between pH on the trunk and the face was significant. We used linear regression equations to estimate truncal pH using only measured pH from the chin. There was no significant relationship between truncal sebum secretion and pH. This was the first study that evaluated the differences and correlations between facial and truncal pH. We found that facial pH can predict truncal pH. In addition, we conclude that differences in pH and sebum secretion between the face and trunk are one of the reasons for differences in acne symptom at those sites.

  6. The pH of Enceladus' ocean

    NASA Astrophysics Data System (ADS)

    Glein, Christopher R.; Baross, John A.; Waite, J. Hunter

    2015-08-01

    Saturn's moon, Enceladus, is a geologically active waterworld. The prevailing paradigm is that there is a subsurface ocean that erupts to the surface, which leads to the formation of a plume of vapor and ice above the south polar region. The chemistry of the ocean is just beginning to be understood, but is of profound geochemical and astrobiological interest. Here, we determine the pH of the ocean using a thermodynamic model of carbonate speciation. Observational data from the Cassini spacecraft are used to make a chemical model of ocean water on Enceladus. The model suggests that Enceladus' ocean is a Na-Cl-CO3 solution with an alkaline pH of ∼11-12. The dominance of aqueous NaCl is a feature that Enceladus' ocean shares with terrestrial seawater, but the ubiquity of dissolved Na2CO3 suggests that soda lakes are more analogous to the Enceladus ocean. The high pH implies that the hydroxide ion should be relatively abundant, while divalent metals should be present at low concentrations owing to buffering by carbonates and phyllosilicates on the ocean floor. Carboxyl groups in dissolved organic species would be negatively charged, while amino groups would exist predominately in the neutral form. Knowledge of the pH improves our understanding of geochemical processes in Enceladus' ocean. The high pH is interpreted to be a key consequence of serpentinization of chondritic rock, as predicted by prior geochemical reaction path models; although degassing of CO2 from the ocean may also play a role depending on the efficiency of mixing processes in the ocean. Serpentinization leads to the generation of H2, a geochemical fuel that can support both abiotic and biological synthesis of organic molecules such as those that have been detected in Enceladus' plume. Serpentinization and H2 generation should have occurred on Enceladus, like on the parent bodies of aqueously altered meteorites; but it is unknown whether these critical processes are still taking place, or if

  7. 21 CFR 876.1400 - Stomach pH electrode.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Stomach pH electrode. 876.1400 Section 876.1400...) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Diagnostic Devices § 876.1400 Stomach pH electrode. (a) Identification. A stomach pH electrode is a device used to measure intragastric and intraesophageal pH...

  8. What Is a pH Probe Study?

    MedlinePlus

    What is a pH Probe Study ? What is pH a probe study? M easuring the pH in the esophagus helps determine whether or not acid is coming up from the stomach. A pH probe study is usually done in patients where ...

  9. 21 CFR 876.1400 - Stomach pH electrode.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Stomach pH electrode. 876.1400 Section 876.1400...) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Diagnostic Devices § 876.1400 Stomach pH electrode. (a) Identification. A stomach pH electrode is a device used to measure intragastric and intraesophageal pH...

  10. 21 CFR 876.1400 - Stomach pH electrode.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Stomach pH electrode. 876.1400 Section 876.1400...) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Diagnostic Devices § 876.1400 Stomach pH electrode. (a) Identification. A stomach pH electrode is a device used to measure intragastric and intraesophageal pH (hydrogen...

  11. 21 CFR 876.1400 - Stomach pH electrode.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Stomach pH electrode. 876.1400 Section 876.1400...) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Diagnostic Devices § 876.1400 Stomach pH electrode. (a) Identification. A stomach pH electrode is a device used to measure intragastric and intraesophageal pH (hydrogen...

  12. 21 CFR 876.1400 - Stomach pH electrode.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Stomach pH electrode. 876.1400 Section 876.1400...) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Diagnostic Devices § 876.1400 Stomach pH electrode. (a) Identification. A stomach pH electrode is a device used to measure intragastric and intraesophageal pH (hydrogen...

  13. PH DEPENDENT TOXICITY OF FIVE METALS TO THREE MARINE ORGANISMS

    EPA Science Inventory

    The pH of natural marine systems is relatively stable; this may explain why metal toxicity changes with pH have not been well documented. However, changes in metal toxicity with pH in marine waters are of concern in toxicity testing. During porewater toxicity testing pH can chang...

  14. [Measurement of intracellular pH].

    PubMed

    Hanaoka, K; Imai, M; Yoshitomi, K

    1992-09-01

    Since various cellular processes depend on changes in pH, the regulation of intracellular pH (pHi) is important both for the individual cell and for the organism. The mechanisms of the regulation of pHi can be investigated by monitoring pHi. In this report, we discuss the four major techniques available for measuring pHi, which are 1) Distribution of weak acids and bases, 2) pH-sensitive microelectrodes, 3) pH-sensitive dyes, and 4) Nuclear magnetic resonance. Among four techniques, the advantage of the microelectrode approach is that it can monitor membrane potential at the same time and be applied to a single cell. The dye technique is a relative new developing technique, which has lots of advantages. It is easy to use, and is capable of monitoring rapid pHi changes, and being applied to a smaller cell, or a single cell.

  15. Not Your Father's Ph.D.

    ERIC Educational Resources Information Center

    Withrow, Brandon G.

    2008-01-01

    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…

  16. Participation of liver progenitor cells in liver regeneration: lack of evidence in the AAF/PH rat model.

    PubMed

    Dusabineza, Ange-Clarisse; Van Hul, Noémi K; Abarca-Quinones, Jorge; Starkel, Peter; Najimi, Mustapha; Leclercq, Isabelle A

    2012-01-01

    When hepatocyte proliferation is impaired, liver progenitor cells (LPC) are activated to participate in liver regeneration. We used the 2-acetaminofluorene/partial hepatectomy (AAF/PH) model to evaluate the contribution of LPC to liver cell replacement and function restoration. Fischer rats subjected to AAF/PH (or PH alone) were investigated 7, 10 and 14 days post-hepatectomy. Liver mass recovery (LMR) was estimated, and the liver mass to body weight ratio calculated. We used serum albumin and bilirubin levels, and liver albumin mRNA levels to assess the liver function. LPC expansion was analyzed by cytokeratin 19 (CK19), glutathione S-transferase protein (GSTp) immunohistochemistry and by CK19, CD133, transforming growth factor-β1 and hepatocyte growth factor mRNA expression in livers. Cell proliferation was evaluated by Ki67 and BrdU immunostaining. Compared with PH alone where LMR was ∼100% 14 days post-PH, LMR was defective in AAF/PH rats (64.1±15.5%, P=0.0004). LPC expansion was scarce in PH livers (0.5±0.4% of CK19(+) area), but significant in AAF/PH livers (8.5±7.2% of CK19(+)), and inversely correlated to LMR (r(2)=0.63, P<0.0001). A quarter of AAF/PH animals presented liver failure (low serum albumin and high serum bilirubin) 14 days post-PH. Compared with animals with preserved function, this was associated with a lower LMR (50±6.8 vs 74.6±9.4%, P=0.0005), a decreased liver to body weight ratio (2±0.3 vs 3.5±0.6%, P=0.001), and a larger LPC expansion such as proliferating Ki67(+) LPC covered 17.4±4.2% of the liver parenchyma vs 3.1±1.5%, (P<0.0001). Amongst those, rare LPC with an intermediate hepatocyte-like phenotype were seen. Also, less than 2% of hepatocytes were engaged into the cell cycle (Ki67(+)), while more numerous (∼25% of hepatocytes) in the livers with preserved function. These observations suggest that, in this model, the efficient recovery of the liver function was ensured rather by the proliferation of mature hepatocytes

  17. Complexation Key to a pH Locked Redox Reaction

    ERIC Educational Resources Information Center

    Rizvi, Masood Ahmad; Dangat, Yuvraj; Shams, Tahir; Khan, Khaliquz Zaman

    2016-01-01

    An unfavorable pH can block a feasible electron transfer for a pH dependent redox reaction. In this experiment, a series of potentiometric titrations demonstrate the sequential loss in feasibility of iron(II) dichromate redox reaction over a pH range of 0-4. The pH at which this reaction failed to occur was termed as a pH locked reaction. The…

  18. Complexation Key to a pH Locked Redox Reaction

    ERIC Educational Resources Information Center

    Rizvi, Masood Ahmad; Dangat, Yuvraj; Shams, Tahir; Khan, Khaliquz Zaman

    2016-01-01

    An unfavorable pH can block a feasible electron transfer for a pH dependent redox reaction. In this experiment, a series of potentiometric titrations demonstrate the sequential loss in feasibility of iron(II) dichromate redox reaction over a pH range of 0-4. The pH at which this reaction failed to occur was termed as a pH locked reaction. The…

  19. Proteorhodopsin Photocycle Kinetics Between pH 5 and pH 9.

    PubMed

    Köhler, Thomas; Weber, Ingrid; Glaubitz, Clemens; Wachtveitl, Josef

    2017-05-01

    The retinal protein proteorhodopsin is a homolog of the well-characterized light-driven proton pump bacteriorhodopsin. Basic mechanisms of proton transport seem to be conserved, but there are noticeable differences in the pH ranges of proton transport. Proton transport and protonation state of a carboxylic acid side chain, the primary proton acceptor, are correlated. In case of proteorhodopsin, the pKa of the primary proton acceptor Asp-97 (pKa  ≈ 7.5) is unexpectedly close to environmental pH (pH ≈ 8). A significant fraction of proteorhodopsin is possibly inactive at natural pH, in contrast to bacteriorhodopsin. We investigated photoinduced kinetics of proteorhodopsin between pH 5 and pH 9 by time resolved UV/vis absorption spectroscopy. Kinetics is inhomogeneous within that pH region and can be considered as a superposition of two fractions. These fractions are correlated with the Asp-97 titration curve. Beside Asp-97, protonation equilibria of other groups influence kinetics, but the observations do not point toward major differences of primary proton acceptor function in proteorhodopsin and bacteriorhodopsin. The pKa of proteorhodopsin and some of its variants is suspected to be an example of molecular adaptation to the physiology of the original organisms. © 2017 The American Society of Photobiology.

  20. The Added Value of a PhD in Medicine--PhD Students' Perceptions of Acquired Competences

    ERIC Educational Resources Information Center

    Anttila, Henrika; Lindblom-Ylänne, Sari; Lonka, Kristi; Pyhältö, Kirsi

    2015-01-01

    PhD in the field of medicine is more common than in any other domain. Many medical doctors are driven towards PhD, but also students with other backgrounds (usually MSc) are conducting a PhD in medical schools. Higher education has invested a lot in developing generic and research competences. Still little is known about how PhD students…

  1. The panacea toolbox of a PhD biomedical student.

    PubMed

    Skaik, Younis

    2014-01-01

    Doing a PhD (doctor of philosophy) for the sake of contribution to knowledge should give the student an immense enthusiasm through the PhD period. It is the time in one's life that one spends to "hit the nail on the head" in a specific area and topic of interest. A PhD consists mostly of hard work and tenacity; however, luck and genius might also play a little role. You can pass all PhD phases without having both luck and genius. The PhD student should have pre-PhD and PhD toolboxes, which are "sine quibus non" for getting successfully a PhD degree. In this manuscript, the toolboxes of the PhD student are discussed.

  2. Six-Channel Spectrophotometers (PH) Onboard JEM-GLIMS

    NASA Astrophysics Data System (ADS)

    Sato, Mitsuteru; Takahashi, Yukihiro; Suzuki, Makoto; Yamazaki, Atsushi; Ushio, Tomoo

    Six-channel spectrophotometers (PH) are the science instruments of JEM-GLIMS to measure absolute intensity of the emission originated from lightning discharges and upper atmospheric transient luminous events (TLEs). PH unit-1 (PH-U1) consists of four spectrophotometer channels named from PH1 to PH4, while PH unit-2 (PH-U2) two spectrophotometer channels named PH5 and PH6. Optical filters of these spectrophotometers are selected to detect TLE emission lines of N2 1PG, N2 2PG, N2+ 1NG, and N2 LBH. Since the bandwidth of the optical filter of PH2, 3, 5, and 6 is 10 nm and since PH1 measures NUV emission, photomultiplier tubes with high-voltage converters are used as a photon detector. To the contrary, PH4 uses a photodiode as a photon detector because the pass-band of the optical filter is enough wide to detect transient optical emission. Though PH does not equip spatial resolution, it can acquire light curve data with a high time resolution of 50 μs with a 12-bit resolution. Thus, the combinational analysis of PH data and Lightning and Sprite Imager (LSI) data, it is possible to clarify the relationship between TLEs and their parent lightning discharges, the occurrence condition of TLEs, and the energy of the electrons which excite TLE emission.

  3. Intracellular pH in sperm physiology.

    PubMed

    Nishigaki, Takuya; José, Omar; González-Cota, Ana Laura; Romero, Francisco; Treviño, Claudia L; Darszon, Alberto

    2014-08-01

    Intracellular pH (pHi) regulation is essential for cell function. Notably, several unique sperm ion transporters and enzymes whose elimination causes infertility are either pHi dependent or somehow related to pHi regulation. Amongst them are: CatSper, a Ca(2+) channel; Slo3, a K(+) channel; the sperm-specific Na(+)/H(+) exchanger and the soluble adenylyl cyclase. It is thus clear that pHi regulation is of the utmost importance for sperm physiology. This review briefly summarizes the key components involved in pHi regulation, their characteristics and participation in fundamental sperm functions such as motility, maturation and the acrosome reaction.

  4. Recent Ph.D.s; Honors

    NASA Astrophysics Data System (ADS)

    2005-04-01

    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.

  5. [Effects of pH on methanogenesis and methanogenic community in the cultures amended with acetate].

    PubMed

    Ma, Tingting; Cheng, Lei; Zheng, Zhenzhen; Qin, Qianshan; Dai, Lirong; Zhang, Hui

    2014-12-04

    To evaluate the effects of pH on methane production from acetate and the methanogenic community structures. Solutions of phosphate (PB), 2-hydroxyethyl (HEPES), NaHCO3/CO2 or piperazine-1,4-bisethanesulfonic acid (PIPES) were added into the methanogenic cultures, separately. The substrate consumption was determined by monitoring cumulative methane production, the methanogenic community structuresin the stationary-phase cultures were analyzed using terminal restriction fragment length polymorphism (T-RFLP) of 16S rRNA gene fragments. The period of lag phase of methane production in the PB addition culture (ca. 40 d) was much longer than that in other pH buffer cultures (20 - 24 d, P < 0.05). Approximate 88.3% of acetate was converted into methane in the NaHCO3/CO2 addition culture, while the value decreased to 77% - 81% in other pH buffer cultures (P < 0.05). The maximum specific methane production rate was similar between different pH buffer cultures (P > 0.05). The relative abundance of members of unclassified bacteria, Spirochaetaceae and uncultured WWE1 increased to (15.5 ± 9.4)%, (7.3 ± 4.6)% and (17.6 ± 6.3)%, respectively, in the NaHCO3/CO2 addition culture, while synergistaceae decreased to (8.9 ± 8.1)%. In archaeal domain, the acetotrophic methanogen related with Methanosaeta harundinacea became predominant (97 ± 2%) in the PB buffer culture, on the contrary, the concurrence of M. harundinacea, M. concilii and hydrogenotrophic methanogen related with Methanobacteriales were detected in the cultures amended with HEPES, PIPES and NaHCO3/CO2. PB retarded the methane production in the acetatemethanogenic culture, NaHCO3/CO2 addition improve methane production from acetate, the pH buffers had not obvious effects on the maximum specific methane production rate of the cultures, the microbial community structures obviously changed along with PB and NaHCO3/CO2 addition. The research would help us to design suitable condition for the growth of methanogenic

  6. The pH of Mars

    NASA Technical Reports Server (NTRS)

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

    1993-01-01

    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 K(sub sp) 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.

  7. Nanomechanical DNA Origami pH Sensors

    PubMed Central

    Kuzuya, Akinori; Watanabe, Ryosuke; Yamanaka, Yusei; Tamaki, Takuya; Kaino, Masafumi; Ohya, Yuichi

    2014-01-01

    Single-molecule pH sensors have been developed by utilizing molecular imaging of pH-responsive shape transition of nanomechanical DNA origami devices with atomic force microscopy (AFM). Short DNA fragments that can form i-motifs were introduced to nanomechanical DNA origami devices with pliers-like shape (DNA Origami Pliers), which consist of two levers of 170-nm long and 20-nm wide connected at a Holliday-junction fulcrum. DNA Origami Pliers can be observed as in three distinct forms; cross, antiparallel and parallel forms, and cross form is the dominant species when no additional interaction is introduced to DNA Origami Pliers. Introduction of nine pairs of 12-mer sequence (5′-AACCCCAACCCC-3′), which dimerize into i-motif quadruplexes upon protonation of cytosine, drives transition of DNA Origami Pliers from open cross form into closed parallel form under acidic conditions. Such pH-dependent transition was clearly imaged on mica in molecular resolution by AFM, showing potential application of the system to single-molecular pH sensors. PMID:25325338

  8. Nanomechanical DNA origami pH sensors.

    PubMed

    Kuzuya, Akinori; Watanabe, Ryosuke; Yamanaka, Yusei; Tamaki, Takuya; Kaino, Masafumi; Ohya, Yuichi

    2014-10-16

    Single-molecule pH sensors have been developed by utilizing molecular imaging of pH-responsive shape transition of nanomechanical DNA origami devices with atomic force microscopy (AFM). Short DNA fragments that can form i-motifs were introduced to nanomechanical DNA origami devices with pliers-like shape (DNA Origami Pliers), which consist of two levers of 170-nm long and 20-nm wide connected at a Holliday-junction fulcrum. DNA Origami Pliers can be observed as in three distinct forms; cross, antiparallel and parallel forms, and cross form is the dominant species when no additional interaction is introduced to DNA Origami Pliers. Introduction of nine pairs of 12-mer sequence (5'-AACCCCAACCCC-3'), which dimerize into i-motif quadruplexes upon protonation of cytosine, drives transition of DNA Origami Pliers from open cross form into closed parallel form under acidic conditions. Such pH-dependent transition was clearly imaged on mica in molecular resolution by AFM, showing potential application of the system to single-molecular pH sensors.

  9. Discordance between urine pH measured by dipstick and pH meter: implications for methotrexate administration protocols.

    PubMed

    Wockenfus, Amy M; Koch, Christopher D; Conlon, Patricia M; Sorensen, Linda D; Cambern, Kari L; Chihak, Amy J; Zmolek, Julie A; Petersen, Amy E; Burns, Bradley E; Lieske, John C; Karon, Brad S

    2013-01-01

    To minimize toxicity of high-dose methotrexate (MTX) therapy, urinary alkalinization with frequent monitoring of urine pH is required. Urine pH is usually assessed by fast and convenient dipstick methods. When urine color interferes with dipstick measurement, as occurs in patients receiving MTX, alternative methods such as pH meters are used. Nursing staff caring for patients on high-dose MTX reported that urine pH results from dipstick and pH analyzers were often clinically discordant. As a result urine pH by dipstick and pH meter were compared in patients on high-dose MTX therapy and patients with normal-colored urine samples. We measured urine pH by dipstick and pH meter in 116 urine samples from 4 patients receiving high-dose MTX therapy, and in 50 normal-colored urine samples from 50 patients not on MTX therapy. In patients on MTX therapy the mean (±standard deviation) bias between dipstick and pH meter urine pH was 0.7±0.4, compared to 0.4±0.3 in patients not on MTX. For patients on MTX clinical concordance between dipstick and pH meter urine results was poor around a clinical cut-off of pH 8.0. Of the 92 samples with a meter urine pH≤8.0, 72 had a discordant value by dipstick (pH>8). Urine pH readings by dipstick and pH meter are not equivalent, and the bias between them is exacerbated in patients on MTX. Institutions with high-dose MTX therapy protocols should not alternate between dipstick and pH meter urine pH monitoring. Copyright © 2012 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

  10. Constant pH simulations of pH responsive polymers

    NASA Astrophysics Data System (ADS)

    Sharma, Arjun; Smith, J. D.; Walters, Keisha B.; Rick, Steven W.

    2016-12-01

    Polyacidic polymers can change structure over a narrow range of pH in a competition between the hydrophobic effect, which favors a compact state, and electrostatic repulsion, which favors an extended state. Constant pH molecular dynamics computer simulations of poly(methacrylic acid) reveal that there are two types of structural changes, one local and one global, which make up the overall response. The local structural response depends on the tacticity of the polymer and leads to different cooperative effects for polymers with different stereochemistries, demonstrating both positive and negative cooperativities.

  11. Catalytic Decomposition of PH3 on Heated Tungsten Wire Surfaces

    NASA Astrophysics Data System (ADS)

    Umemoto, Hironobu; Nishihara, Yushin; Ishikawa, Takuma; Yamamoto, Shingo

    2012-08-01

    The catalytic decomposition processes of PH3 on heated tungsten surfaces were studied to clarify the mechanisms governing phosphorus doping into silicon substrates. Mass spectrometric measurements show that PH3 can be decomposed by more than 50% over 2000 K. H, P, PH, and PH2 radicals were identified by laser spectroscopic techniques. Absolute density measurements of these radical species, as well as their PH3 flow rate dependence, show that the major products on the catalyst surfaces are P and H atoms, while PH and PH2 are produced in secondary processes in the gas phase. In other words, catalytic decomposition, unlike plasma decomposition processes, can be a clean source of P atoms, which can be the only major dopant precursors. In the presence of an excess amount of H2, the apparent decomposition efficiency is small. This can be explained by rapid cyclic reactions including decomposition, deposition, and etching to reproduce PH3.

  12. Organelle pH in the Arabidopsis endomembrane system.

    PubMed

    Shen, Jinbo; Zeng, Yonglun; Zhuang, Xiaohong; Sun, Lei; Yao, Xiaoqiang; Pimpl, Peter; Jiang, Liwen

    2013-09-01

    The pH of intracellular compartments is essential for the viability of cells. Despite its relevance, little is known about the pH of these compartments. To measure pH in vivo, we have first generated two pH sensors by combining the improved-solubility feature of solubility-modified green fluorescent protein (GFP) (smGFP) with the pH-sensing capability of the pHluorins and codon optimized for expression in Arabidopsis. PEpHluorin (plant-solubility-modified ecliptic pHluorin) gradually loses fluorescence as pH is lowered with fluorescence vanishing at pH 6.2 and PRpHluorin (plant-solubility-modified ratiomatric pHluorin), a dual-excitation sensor, allowing for precise measurements. Compartment-specific sensors were generated by further fusing specific sorting signals to PEpHluorin and PRpHluorin. Our results show that the pH of cytosol and nucleus is similar (pH 7.3 and 7.2), while peroxisomes, mitochondrial matrix, and plastidial stroma have alkaline pH. Compartments of the secretory pathway reveal a gradual acidification, spanning from pH 7.1 in the endoplasmic reticulum (ER) to pH 5.2 in the vacuole. Surprisingly, pH in the trans-Golgi network (TGN) and multivesicular body (MVB) is, with pH 6.3 and 6.2, quite similar. The inhibition of vacuolar-type H(+)-ATPase (V-ATPase) with concanamycin A (ConcA) caused drastic increase in pH in TGN and vacuole. Overall, the PEpHluorin and PRpHluorin are excellent pH sensors for visualization and quantification of pH in vivo, respectively.

  13. Steel slag raises pH of greenhouse substrates

    USDA-ARS?s Scientific Manuscript database

    Dolomitic lime (DL) is the primary liming agent used for increasing pH in peatmoss-based substrates. Steel slag (SS) is a byproduct of the steel manufacturing industry that has been used to elevate field soil pH. The objective of this research was to determine the pH response of a peatmoss-based g...

  14. Acid Rain, pH & Acidity: A Common Misinterpretation.

    ERIC Educational Resources Information Center

    Clark, David B.; Thompson, Ronald E.

    1989-01-01

    Illustrates the basis for misleading statements about the relationship between pH and acid content in acid rain. Explains why pH cannot be used as a measure of acidity for rain or any other solution. Suggests that teachers present acidity and pH as two separate and distinct concepts. (RT)

  15. Acid Rain, pH & Acidity: A Common Misinterpretation.

    ERIC Educational Resources Information Center

    Clark, David B.; Thompson, Ronald E.

    1989-01-01

    Illustrates the basis for misleading statements about the relationship between pH and acid content in acid rain. Explains why pH cannot be used as a measure of acidity for rain or any other solution. Suggests that teachers present acidity and pH as two separate and distinct concepts. (RT)

  16. 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 ...

  17. A Multiattributes Approach for Ranking PhD Programs

    ERIC Educational Resources Information Center

    Urbancic, Frank R.

    2008-01-01

    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…

  18. Intracellular pH in Sperm Physiology

    PubMed Central

    Nishigaki, Takuya; José, Omar; González-Cota, Ana Laura; Romero, Francisco; Treviño, Claudia L.; Darszon, Alberto

    2014-01-01

    Intracellular pH (pHi) regulation is essential for cell function. Notably, several unique sperm ion transporters and enzymes whose elimination causes infertility are either pHi dependent or somehow related to pHi regulation. Amongst them are: CatSper, a Ca2+ channel; Slo3, a K+ channel; the sperm-specific Na+/H+ exchanger and the soluble adenylyl cyclase. It is thus clear that pHi regulation is of the utmost importance for sperm physiology. This review briefly summarizes the key components involved in pHi regulation, their characteristics and participation in fundamental sperm functions such as motility, maturation and the acrosome reaction. PMID:24887564

  19. Ian Douglass Coulter, PhD

    PubMed Central

    Brown, Douglas M

    2004-01-01

    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. PMID:17549218

  20. Barrett's oesophagus: pH profile.

    PubMed

    Gillen, P; Keeling, P; Byrne, P J; Hennessy, T P

    1987-09-01

    Twenty-four patients with a columnar-lined (Barrett's) oesophagus underwent oesophageal manometry and 24 h ambulatory oesophageal pH monitoring. The results were compared with 25 patients with oesophagitis studied in the same fashion. No significant difference in lower oesophageal sphincter pressure was demonstrated between the two groups. The Barrett's patients demonstrated significantly greater acid exposure in the distal oesophagus than oesophagitis patients. Clearance or refluxed acid was poorer in Barrett's patients than oesophagitis patients. Twelve of the Barrett's patients presented with complications of the condition, i.e. ulceration or stricture. No significant difference in acid exposure was demonstrated between Barrett's patients with or without complications. These results suggest that patients with columnar-lined (Barrett's) oesophagus have greater acid exposure than patients with oesophagitis. The development of complications of a Barrett's oesophagus may not be dependent on acid reflux alone.

  1. Understanding Non-Traditional PhD Students Habitus--Implications for PhD Programmes

    ERIC Educational Resources Information Center

    Naidoo, Devika

    2015-01-01

    Against the background of vast changes in doctoral education and the emergence of non-traditional doctoral programmes, this paper investigates the habitus of non-traditional PhD students at a South African university. Bourdieu's conceptual tool of habitus informed the study. In-depth and open-ended interviews were conducted with 10 non-traditional…

  2. High temperature pH measurements using novel pH electrodes. Final report

    SciTech Connect

    Macdonald, D.D.; Song, H.; Hettiarachchi, S.

    1995-12-01

    Researchers used three pH sensors: (1) a yttria-stabilized zirconia, (2) tungsten/tungsten oxide, and (3) platinum hydrogen electrodes to measure the pH in concentrated solutions heated to temperatures from 125-300 C in autoclaves. The studies indicated measurements of pH for solutions containing sodium hydroxide, sodium sulfate, sodium chloride, boric acid, ferrous sulfate, nickel sulfate, and chromous sulfate in various compositions. The solution composition and pH was then calculated by MULTEQ at the experimental conditions. These calculations compared well with the experimental measurements for binary and quaternary systems at temperatures to 300 C and concentrations to 1 molal. The agreement was also excellent for the metal sulfate systems but was poor for chromous sulfate. The agreement for boric acid solutions was adequate for low concentrations of boric acid but was poor for concentrated borate solutions where polyborate ions likely exist. It is not known whether the lack of agreement under these conditions is due to deficiencies in MULTEQ or the experimental measurements.

  3. Understanding Non-Traditional PhD Students Habitus--Implications for PhD Programmes

    ERIC Educational Resources Information Center

    Naidoo, Devika

    2015-01-01

    Against the background of vast changes in doctoral education and the emergence of non-traditional doctoral programmes, this paper investigates the habitus of non-traditional PhD students at a South African university. Bourdieu's conceptual tool of habitus informed the study. In-depth and open-ended interviews were conducted with 10 non-traditional…

  4. Comparison of rumen fluid pH by continuous telemetry system and bench pH meter in sheep with different ranges of ruminal pH.

    PubMed

    Reis, Leonardo F; Minervino, Antonio H H; Araújo, Carolina A S C; Sousa, Rejane S; Oliveira, Francisco L C; Rodrigues, Frederico A M L; Meira-Júnior, Enoch B S; Barrêto-Júnior, Raimundo A; Mori, Clara S; Ortolani, Enrico L

    2014-01-01

    We aimed to compare the measurements of sheep ruminal pH using a continuous telemetry system or a bench pH meter using sheep with different degrees of ruminal pH. Ruminal lactic acidosis was induced in nine adult crossbred Santa Ines sheep by the administration of 15 g of sucrose per kg/BW. Samples of rumen fluid were collected at the baseline, before the induction of acidosis (T 0) and at six, 12, 18, 24, 48, and 72 hours after the induction for pH measurement using a bench pH meter. During this 72-hour period, all animals had electrodes for the continuous measurement of pH. The results were compared using the Bland-Altman analysis of agreement, Pearson coefficients of correlation and determination, and paired analysis of variance with Student's t-test. The measurement methods presented a strong correlation (r = 0.94, P < 0.05) but the rumen pH that was measured continuously using a telemetry system resulted in lower values than the bench pH meter (overall mean of 5.38 and 5.48, resp., P = 0.0001). The telemetry system was able to detect smaller changes in rumen fluid pH and was more accurate in diagnosing both subacute ruminal lactic acidosis and acute ruminal lactic acidosis in sheep.

  5. Comparison of Rumen Fluid pH by Continuous Telemetry System and Bench pH Meter in Sheep with Different Ranges of Ruminal pH

    PubMed Central

    Reis, Leonardo F.; Minervino, Antonio H. H.; Araújo, Carolina A. S. C.; Sousa, Rejane S.; Oliveira, Francisco L. C.; Rodrigues, Frederico A. M. L.; Meira-Júnior, Enoch B. S.; Barrêto-Júnior, Raimundo A.; Mori, Clara S.; Ortolani, Enrico L.

    2014-01-01

    We aimed to compare the measurements of sheep ruminal pH using a continuous telemetry system or a bench pH meter using sheep with different degrees of ruminal pH. Ruminal lactic acidosis was induced in nine adult crossbred Santa Ines sheep by the administration of 15 g of sucrose per kg/BW. Samples of rumen fluid were collected at the baseline, before the induction of acidosis (T0) and at six, 12, 18, 24, 48, and 72 hours after the induction for pH measurement using a bench pH meter. During this 72-hour period, all animals had electrodes for the continuous measurement of pH. The results were compared using the Bland-Altman analysis of agreement, Pearson coefficients of correlation and determination, and paired analysis of variance with Student's t-test. The measurement methods presented a strong correlation (r = 0.94, P < 0.05) but the rumen pH that was measured continuously using a telemetry system resulted in lower values than the bench pH meter (overall mean of 5.38 and 5.48, resp., P = 0.0001). The telemetry system was able to detect smaller changes in rumen fluid pH and was more accurate in diagnosing both subacute ruminal lactic acidosis and acute ruminal lactic acidosis in sheep. PMID:24967422

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

    ERIC Educational Resources Information Center

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

    2008-01-01

    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 what…

  7. pH distributions in spontaneous and isotransplanted rat tumours.

    PubMed Central

    Kallinowski, F.; Vaupel, P.

    1988-01-01

    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. PMID:3179183

  8. Proton Transport and pH Control in Fungi.

    PubMed

    Kane, Patricia M

    2016-01-01

    Despite diverse and changing extracellular environments, fungi maintain a relatively constant cytosolic pH and numerous organelles of distinct lumenal pH. Key players in fungal pH control are V-ATPases and the P-type proton pump Pma1. These two proton pumps act in concert with a large array of other transporters and are highly regulated. The activities of Pma1 and the V-ATPase are coordinated under some conditions, suggesting that pH in the cytosol and organelles is not controlled independently. Genomic studies, particularly in the highly tractable S. cerevisiae, are beginning to provide a systems-level view of pH control, including transcriptional responses to acid or alkaline ambient pH and definition of the full set of regulators required to maintain pH homeostasis. Genetically encoded pH sensors have provided new insights into localized mechanisms of pH control, as well as highlighting the dynamic nature of pH responses to the extracellular environment. Recent studies indicate that cellular pH plays a genuine signaling role that connects nutrient availability and growth rate through a number of mechanisms. Many of the pH control mechanisms found in S. cerevisiae are shared with other fungi, with adaptations for their individual physiological contexts. Fungi deploy certain proton transport and pH control mechanisms not shared with other eukaryotes; these regulators of cellular pH are potential antifungal targets. This review describes current and emerging knowledge proton transport and pH control mechanisms in S. cerevisiae and briefly discusses how these mechanisms vary among fungi.

  9. The Role of pH Regulation in Cancer Progression.

    PubMed

    McIntyre, Alan; Harris, Adrian L

    Frequently observed phenotypes of tumours include high metabolic activity, hypoxia and poor perfusion; these act to produce an acidic microenvironment. Cellular function depends on pH homoeostasis, and thus, tumours become dependent on pH regulatory mechanisms. Many of the proteins involved in pH regulation are highly expressed in tumours, and their expression is often of prognostic significance. The more acidic tumour microenvironment also has important implications with regard to chemotherapeutic and radiotherapeutic interventions. In addition, we review pH-sensing mechanisms, the role of pH regulation in tumour phenotype and the use of pH regulatory mechanisms as therapeutic targets.

  10. PH-sensitive dispersion of carbon nanotubes by myoglobin

    NASA Astrophysics Data System (ADS)

    Nie, Haiyu; Shen, Ganni; Sun, Junlin; Zhang, Tao

    2017-03-01

    A facile and effective method of dispersion of double-walled carbon nanotubes (DWNTs) was developed. At appropriate pH value and sonication, myoglobin helps the solubilization of DWNTs. The product is a pH-sensitive dispersion, which remains in a highly dispersed state at pH<3.0 and pH>10.0. This approach can be used to disperse DWNTs in scale. A reversible conversion of the highly dispersed state to the aggregated state could be observed by changing the pH value. This feature holds great promise for the development of pH sensors.

  11. pH in atomic scale simulations of electrochemical interfaces.

    PubMed

    Rossmeisl, Jan; Chan, Karen; Ahmed, Rizwan; Tripković, Vladimir; Björketun, Mårten E

    2013-07-07

    Electrochemical reaction rates can strongly depend on pH, and there is increasing interest in electrocatalysis in alkaline solution. To date, no method has been devised to address pH in atomic scale simulations. We present a simple method to determine the atomic structure of the metal|solution interface at a given pH and electrode potential. Using Pt(111)|water as an example, we show the effect of pH on the interfacial structure, and discuss its impact on reaction energies and barriers. This method paves the way for ab initio studies of pH effects on the structure and electrocatalytic activity of electrochemical interfaces.

  12. Continuous intra-arterial pH measurement.

    PubMed

    Oeseburg, B; Kwant, G; Schut, J K; Veenstra, J

    1980-07-01

    A flexible glass electrode catheter with a diameter of 3 mm has been developed for pH measurement in the arterial system of dogs. In combination with a galvanically isolated amplifier, an undisturbed pH signal could be obtained from the aorta. The system was fast enough to truly record pH changes synchronous with respiration and was shown to be insensitive to variations in blood flow velocity. Good agreement was found between pH catheter readings nd pH values of simultaneously taken arterial samples as measured with a conventional capillary glass electrode.

  13. Time course of pH change in plant epidermis using microscopic pH imaging system

    NASA Astrophysics Data System (ADS)

    Dan, Risako; Shimizu, Megumi; Kazama, Haruko; Sakaue, Hirotaka

    2010-11-01

    We established a microscopic pH imaging system to track the time course of pH change in plant epidermis in vivo. In the previous research, we have found out that anthocyanin containing cells have higher pH. However, it was not clear whether the anthocyanin increased the pH or anthocyanin was synthesized result from the higher pH. Therefore, we further investigated the relationship between anthocyanin and pH change. To track the time course of pH change in plant epidermis, we established a system using luminescent imaging technique. We used HPTS (8-Hydroxypyrene-1,3,6-Trisulfonate) as pH indicator and applied excitation ratio imaging method. Luminescent image was converted to a pH distribution by obtained in vitro calibration using known pH solution. Cellular level observation was enabled by merging microscopic color picture of the same region to the pH change image. The established system was applied to epidermal cells of red-tip leaf lettuce, Lactuca Sativa L. and the time course was tracked in the growth process. We would discuss about the relationship between anthocyanin and pH change in plant epidermis.

  14. [Vulvovaginitis: vaginal pH changes and associated microflora].

    PubMed

    Saturnino, Ana Conceiçáo Ribeiro Dantas; Sisenando, Herbert Ary Arzabe Anteza Costa Nóbrega; Pereira, Alessandra Ramalho; Vale, Ana Patrícia Medeiros; Pires, Leila Monte; de Araújo, Jarine Torres; Ramos, Eleni Souto Nóbrega

    2005-01-01

    To establish a correlation between pH vaginal and the microflora associated in carriers of vulvovaginites. In the present study, the cytopathological examination and the vaginal flow in a group of 65 sexually active women had been carried through, 20 and 72 years, taken care of in the Laboratório de Citologia Clínica do Departamento de Análises Clínicas e Toxicológicas da Universidade Federal do Rio Grande do Norte, for determination of microorganisms in cervicovaginal sample and of pH in the vaginal flow. Associating pH vaginal with the presence of vulvovaginitis, it was evidenced that the Candida sp. occurred more frequently in pH 4.0, Trichomonas vaginalis in pH 6.0, Gardnerella vaginalis in pH 5.0, coconuts in pH 5.0, bacilli in pH 4.0 and cocos/bacilos in pH 6.0. It was observed that all the patients had presented at least one type of ethiological agent of vulvovaginiti and an associated microflora. The joint accomplishment of the cytological examinations and the determination of pH revealed important for directing the microflora associated with the vulvovaginiti, suggesting, of this form, that pH vaginal plays preponderant role how much to the presence of the infectious agents in the vaginal ecosystem.

  15. The F/Ph rearrangement reaction of [(Ph3P)3RhF], the fluoride congener of Wilkinson's catalyst.

    PubMed

    Macgregor, Stuart A; Roe, D Christopher; Marshall, William J; Bloch, Karen M; Bakhmutov, Vladimir I; Grushin, Vladimir V

    2005-11-02

    The fluoride congener of Wilkinson's catalyst, [(Ph(3)P)(3)RhF] (1), has been synthesized and fully characterized. Unlike Wilkinson's catalyst, 1 easily activates the inert C-Cl bond of ArCl (Ar = Ph, p-tolyl) under mild conditions (3 h at 80 degrees C) to produce trans-[(Ph(3)P)(2)Rh(Ph(2)PF)(Cl)] (2) and ArPh as a result of C-Cl, Rh-F, and P-C bond cleavage and C-C, Rh-Cl, and P-F bond formation. In benzene (2-3 h at 80 degrees C), 1 decomposes to a 1:1 mixture of trans-[(Ph(3)P)(2)Rh(Ph(2)PF)(F)] (3) and the cyclometalated complex [(Ph(3)P)(2)Rh(Ph(2)PC(6)H(4))] (4). Both the chloroarene activation and the thermal decomposition reactions have been shown to occur via the facile and reversible F/Ph rearrangement reaction of 1 to cis-[(Ph(3)P)(2)Rh(Ph)(Ph(2)PF)] (5), which has been isolated and fully characterized. Kinetic studies of the F/Ph rearrangement, an intramolecular process not influenced by extra phosphine, have led to the determination of E(a) = 22.7 +/- 1.2 kcal mol(-)(1), DeltaH(++) = 22.0 +/- 1.2 kcal mol(-)(1), and DeltaS(++) = -10.0 +/- 3.7 eu. Theoretical studies of F/Ph exchange with the [(PH(3))(2)(PH(2)Ph)RhF] model system pointed to two possible mechanisms: (i) Ph transfer to Rh followed by F transfer to P (formally oxidative addition followed by reductive elimination, pathway 1) and (ii) F transfer to produce a metallophosphorane with subsequent Ph transfer to Rh (pathway 2). Although pathway 1 cannot be ruled out completely, the metallophosphorane mechanism finds more support from both our own and previously reported observations. Possible involvement of metallophosphorane intermediates in various P-F, P-O, and P-C bond-forming reactions at a metal center is discussed.

  16. To PhET or Not To PhET: That Is the Question

    NASA Astrophysics Data System (ADS)

    Casao, Robert

    2008-10-01

    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.

  17. Accurate transport properties for O(3P)-H and O(3P)-H2

    NASA Astrophysics Data System (ADS)

    Dagdigian, Paul J.; Kłos, Jacek; Warehime, Mick; Alexander, Millard H.

    2016-10-01

    Transport properties for collisions of oxygen atoms with hydrogen atoms and hydrogen molecules have been computed by means of time-independent quantum scattering calculations. For the O(3P)-H(2S) interaction, potential energy curves for the four OH electronic states emanating from this asymptote were computed by the internally-contracted multi-reference configuration interaction method, and the R-dependent spin-orbit matrix elements were taken from Parlant and Yarkony [J. Chem. Phys. 110, 363 (1999)]. For the O(3P)-H2 interaction, diabatic potential energy surfaces were derived from internally contracted multi-reference configuration interaction calculations. Transport properties were computed for these two collision pairs and compared with those obtained with the conventional approach that employs isotropic Lennard-Jones (12-6) potentials.

  18. Low pH alkaline chemical formulations

    SciTech Connect

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

    1989-01-01

    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.

  19. Combined M.D./Ph.D. and Ph.D. Training Program in Breast Cancer Prevention

    DTIC Science & Technology

    2005-07-01

    of trainees, and the development of courses for the program. In the sixth year, we recruited Ms. Anne Miermont and Mr. Mark Markowski . Ms. Miermont...Baltimore County. Mr. Markowski , an MD/PhD student received his BS in Biochemistry and Mathematics from Georgetown University. Ms. Miermont is...currently working in the lab of her Thesis Mentor, Dr. Priscilla Furth. Mr. Markowski is currently working in the lab of Thesis Mentor Dr. Edward Gelmann

  20. Italia-Netherland PhD Program: the I.O. PhD Research Program.

    PubMed

    Bellissima, Valentina; Borghesi, Alessandro; Bozzetti, Valentina; Dessì, Angelica; Fabiano, Adele; Risso, Francesco M; Salvo, Vincenzo; Satriano, Angela; Silvagni, Davide; Varrica, Alessandro; van Bel, Frank; Visser, Gerard H A; Vles, Hans Js; Zimmermann, Luc J I; Gavilanes, Antonio D W; Gazzolo, Diego

    2011-10-01

    In the framework of long-term scientific collaboration among the founder members coming from Holland and Italy there was a growing consensus to activate a philosophical doctorate (PhD) program, involving young Italian researchers in the field of perinatal medicine, neonatology and pediatrics. The aims were to promote excellence in research, offering to young Italian physicians the opportunity to maturate an International research experience leading to PhD degree, and to promote human and technological improvement energies in perinatal, neonatal and pediatrics research. Thus, an official collaboration among the Dutch Universities from Maastricht and Utrecht and the Italian Children's Hospital from Alessandria, has been activated on March 1st 2010, finalized to the PhD program. The experimental phase included the selection of projects and relative candidates after an interview-selection focusing on their scientific attitudes and the availability on their research projects. Candidates' selection started on May 2010 and on September 29th ten projects and candidates have been approved by the scientific commission. Research topics included: perinatal asphyxia, aging and the origin of adulthood neurodegenerative disease, neuroprotective strategies, biochemical pulmonology, intrauterine growth retardation and perinatal teratology. To date, all projects have been approved by local Ethics Committee from the University/Hospital of origin of the candidates. Five manuscripts have been published and/or submitted to international Journals regarding pneumology, perinatal asphyxia and teratology, whilst about 60-70% of data regarding clinical studies have already been collected.

  1. Dipstick Spot urine pH does not accurately represent 24 hour urine PH measured by an electrode

    PubMed Central

    Omar, Mohamed; Sarkissian, Carl; Jianbo, Li; Calle, Juan; Monga, Manoj

    2016-01-01

    ABSTRACT Objectives To determine whether spot urine pH measured by dipstick is an accurate representation of 24 hours urine pH measured by an electrode. Materials and Methods We retrospectively reviewed urine pH results of patients who presented to the urology stone clinic. For each patient we recorded the most recent pH result measured by dipstick from a spot urine sample that preceded the result of a 24-hour urine pH measured by the use of a pH electrode. Patients were excluded if there was a change in medications or dietary recommendations or if the two samples were more than 4 months apart. A difference of more than 0.5 pH was considered an inaccurate result. Results A total 600 patients were retrospectively reviewed for the pH results. The mean difference in pH between spot urine value and the 24 hours collection values was 0.52±0.45 pH. Higher pH was associated with lower accuracy (p<0.001). The accuracy of spot urine samples to predict 24-hour pH values of <5.5 was 68.9%, 68.2% for 5.5 to 6.5 and 35% for >6.5. Samples taken more than 75 days apart had only 49% the accuracy of more recent samples (p<0.002). The overall accuracy is lower than 80% (p<0.001). Influence of diurnal variation was not significant (p=0.588). Conclusions Spot urine pH by dipstick is not an accurate method for evaluation of the patients with urolithiasis. Patients with alkaline urine are more prone to error with reliance on spot urine pH. PMID:27286119

  2. Dipstick Spot urine pH does not accurately represent 24 hour urine PH measured by an electrode.

    PubMed

    Omar, Mohamed; Sarkissian, Carl; Jianbo, Li; Calle, Juan; Monga, Manoj

    2016-01-01

    To determine whether spot urine pH measured by dipstick is an accurate representation of 24 hours urine pH measured by an electrode. We retrospectively reviewed urine pH results of patients who presented to the urology stone clinic. For each patient we recorded the most recente pH result measured by dipstick from a spot urine sample that preceded the result of a 24-hour urine pH measured by the use of a pH electrode. Patients were excluded if there was a change in medications or dietary recommendations or if the two samples were more than 4 months apart. A difference of more than 0.5 pH was considered na inaccurate result. A total 600 patients were retrospectively reviewed for the pH results. The mean difference in pH between spot urine value and the 24 hours collection values was 0.52±0.45 pH. Higher pH was associated with lower accuracy (p<0.001). The accuracy of spot urine samples to predict 24-hour pH values of <5.5 was 68.9%, 68.2% for 5.5 to 6.5 and 35% for >6.5. Samples taken more than 75 days apart had only 49% the accuracy of more recent samples (p<0.002). The overall accuracy is lower than 80% (p<0.001). Influence of diurnal variation was not significant (p=0.588). Spot urine pH by dipstick is not an accurate method for evaluation of the patients with urolithiasis. Patients with alkaline urine are more prone to error with reliance on spot urine pH.

  3. In vitro synthesis and purification of PhIP-deoxyguanosine and PhIP-DNA oligomer covalent complexes

    SciTech Connect

    Freeman, J.

    1994-12-01

    2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) is a heterocyclic amine compound formed when meats are cooked at high temperatures. PhIP damages DNA by forming covalent complexes with DNA carcinogen. In an effort to understand how the binding of PhIP to DNA may cause cancer, it is important to characterize the structures of PhIP-damaged DNA molecules. Our HPLC data support fluorescence and {sup 32}P Post-labeling studies which indicate the formation of several species of 2{prime}deoxyguanosine-(dG) or oligodeoxynucleotide-PhIP adducts. The reaction of PhIP with dG resulted in a reddish precipitate that was likely the major adduct, N-(deoxyguanosin-8-yl)-PhIP (dG-C8-PhIP) adduct, with a more polar adduct fraction remaining in the supernatant. Reversed-phase HPLC analysis of the adducts in the supernatant revealed the existence of species of much shorter retention times than the dG-C8-PhIP adduct, confirming that these species are more polar than dG-C8-PhIP. At least four adducts were formed in the reaction of PhIP with DNA oligomer. HPLC analysis of the PhIP-DNA oligomer supernatant after butanol extractions revealed four unresolved peaks which spectra had maximum wavelengths between 340 and 360 nm. Though adduct peaks were not completely resolved, there was {approximately}3 minutes interval between the DNA oligomer peak and the adduct peaks. Furthermore, fluorescence emission data of the DNA oligomer-PhIP adduct solution show heterogeneous binding. The more polar PhIP adducts were fraction-collected and their structures will be solved by nuclear magnetic resonance or x-ray crystallography.

  4. Lung lamellar bodies maintain an acidic internal pH

    SciTech Connect

    Chander, A.; Johnson, R.G.; Reicherter, J.; Fisher, A.B.

    1986-05-05

    The internal pH of lung lamellar bodies was investigated with membrane permeable basic amines. Isolated granular pneumocytes and isolated lung lamellar bodies exhibited fluorescence when exposed to 8 microM quinacrine, suggesting accumulation of this dye due to an acidic internal pH. Uptake of (/sup 14/C)methylamine by isolated lung lamellar bodies was measured to quantitate the intralamellar body pH. In KCl-ATP (10 mM) medium (pH 7.0), the accumulation ratio of methylamine (inside/outside) during 2-min incubation was 8.1 +/- 0.47 (mean +/- S.E., n = 8) indicating an internal pH of 6.1. Lamellar bodies accumulated methylamine almost 30-fold in K+-free mannitol medium indicating an internal pH of 5.6. The pH gradient across the lamellar body membrane decreased when external pH was decreased or when ATP was omitted. The pH gradient was also decreased by the addition of 10 mM NH/sub 4/Cl, 2 micrograms/ml nigericin, 0.02 mM N,N'-dicyclohexylcarbodiimide, or 1 mM N'-ethylmaleimide. These observations indicate that lamellar bodies maintain an acidic interior (pH 6.1 or below) which is generated by an energy-dependent process.

  5. Osmolytes contribute to pH homeostasis of Escherichia coli.

    PubMed

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

    2010-04-08

    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. 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. 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.

  6. Uses of pH electrodes in nuclear chemistry.

    PubMed

    Ekberg, C; Andersson, S; Olsson, M

    2002-11-01

    The determination and definition of pH is a controversial subject in many areas in chemistry. For these reasons the International Union of Pure and Applied Chemistry (IUPAC) has developed recommendations for pH measurement. These recommendations are currently (winter 2001) under revision - there will be increased emphasis on traceability of uncertainties in pH measurement. Here we describe how glass electrodes designed for measurement of pH are used in nuclear chemistry. The use of pH electrodes is then related to the IUPAC recommendations. In applied chemistry, e.g. nuclear chemistry, a pH is not sought as often as a hydrogen ion concentration or a simple equilibrium point during a titration. Ionic strengths are, moreover, often above the range in which the IUPAC recommendations apply. In these instances uncertainties must be assessed individually.

  7. pH measurement of low-conductivity waters

    USGS Publications Warehouse

    Busenberg, Eurybiades; Plummer, L.N.

    1987-01-01

    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)

  8. Cell wall pH and auxin transport velocity

    NASA Technical Reports Server (NTRS)

    Hasenstein, K. H.; Rayle, D.

    1984-01-01

    According to the chemiosmotic polar diffusion hypothesis, auxin pulse velocity and basal secretion should increase with decreasing cell wall pH. Experiments were designed to test this prediction. Avena coleoptile sections were preincubated in either fusicoccin (FC), cycloheximide, pH 4.0, or pH 8.0 buffer and subsequently their polar transport capacities were determined. Relative to controls, FC enhanced auxin (IAA) uptake while CHI and pH 8.0 buffer reduced IAA uptake. Nevertheless, FC reduced IAA pulse velocity while cycloheximide increased velocity. Additional experiments showed that delivery of auxin to receivers is enhanced by increased receiver pH. This phenomenon was overcome by a pretreatment of the tissue with IAA. Our data suggest that while acidic wall pH values facilitate cellular IAA uptake, they do not enhance pulse velocity or basal secretion. These findings are inconsistent with the chemiosmotic hypothesis for auxin transport.

  9. Soil ph Control in the Mobile Corrosion Monitoring

    NASA Astrophysics Data System (ADS)

    Radenkov, T. A.; Romanenko, S. V.; Kolpakov, V. A.; E Merzlyakov, O.; Kabanov, V. A.; Kagirov, A. G.

    2017-04-01

    Corrosion monitoring methods and pH measuring devices are studied. Considering the heterogeneity of the soil pH, depending on depth and sampling points, it is advisable to use solid-state potentiometric sensors that are capable of pH measuring with an error not exceeding 0.2 pH units. In the process of the pipeline installation necessary to control the soil pH value. While it is impossible to predict what kind of horizon will be in contact with the pipe material at different points. This problem requires future development of technique for the correct pH measuring for the purpose of mobile pipeline corrosion monitoring. When using cathodic protection has been required find the balance between the parameters which prevent the corrosion reactions and also take into account the hydrogen absorption on surface of the pipes material.

  10. Cell wall pH and auxin transport velocity

    NASA Technical Reports Server (NTRS)

    Hasenstein, K. H.; Rayle, D.

    1984-01-01

    According to the chemiosmotic polar diffusion hypothesis, auxin pulse velocity and basal secretion should increase with decreasing cell wall pH. Experiments were designed to test this prediction. Avena coleoptile sections were preincubated in either fusicoccin (FC), cycloheximide, pH 4.0, or pH 8.0 buffer and subsequently their polar transport capacities were determined. Relative to controls, FC enhanced auxin (IAA) uptake while CHI and pH 8.0 buffer reduced IAA uptake. Nevertheless, FC reduced IAA pulse velocity while cycloheximide increased velocity. Additional experiments showed that delivery of auxin to receivers is enhanced by increased receiver pH. This phenomenon was overcome by a pretreatment of the tissue with IAA. Our data suggest that while acidic wall pH values facilitate cellular IAA uptake, they do not enhance pulse velocity or basal secretion. These findings are inconsistent with the chemiosmotic hypothesis for auxin transport.

  11. Computer model of unstirred layer and intracellular pH changes. Determinants of unstirred layer pH.

    PubMed

    Marrannes, Roger

    2013-06-01

    Transmembrane acid-base fluxes affect the intracellular pH and unstirred layer pH around a superfused biological preparation. In this paper the factors influencing the unstirred layer pH and its gradient are studied. An analytical expression of the unstirred layer pH gradient in steady state is derived as a function of simultaneous transmembrane fluxes of (weak) acids and bases with the dehydration reaction of carbonic acid in equilibrium. Also a multicompartment computer model is described consisting of the extracellular bulk compartment, different unstirred layer compartments and the intracellular compartment. With this model also transient changes and the influence of carbonic anhydrase (CA) can be studied. The analytical expression and simulations with the multicompartment model demonstrate that in steady state the unstirred layer pH and its gradient are influenced by the size and type of transmembrane flux of acids and bases, their dissociation constant and diffusion coefficient, the concentration, diffusion coefficient and type of mobile buffers and the activity and location of CA. Similar principles contribute to the amplitude of the unstirred layer pH transients. According to these models an immobile buffer does not influence the steady-state pH, but reduces the amplitude of pH transients especially when these are fast. The unstirred layer pH provides useful information about transmembrane acid-base fluxes. This paper gives more insight how the unstirred layer pH and its transients can be interpreted. Methodological issues are discussed.

  12. Optrodes of photonic fiber to pH sensor

    NASA Astrophysics Data System (ADS)

    Rendón-Romero, A.; Peña-Gomar, M.; Alvarado-Méndez, E.

    2012-10-01

    In this paper, design of optrodes of photonic optical fiber to a pH sensor with a pH dye is described. The sensor is prepared by immobilizing blue bromophenol, as a pH dye, using sol-gel technique with a photonic optical fiber. The physical principle is based in the absorption of the optrodes of the light from a laser diode as an emitter, and as transducer we use a photoresist for electronic conditioning of the signal.

  13. Ratiometric Imaging of Extracellular pH in Dental Biofilms.

    PubMed

    Schlafer, Sebastian; Dige, Irene

    2016-03-09

    The pH in bacterial biofilms on teeth is of central importance for dental caries, a disease with a high worldwide prevalence. Nutrients and metabolites are not distributed evenly in dental biofilms. A complex interplay of sorption to and reaction with organic matter in the biofilm reduces the diffusion paths of solutes and creates steep gradients of reactive molecules, including organic acids, across the biofilm. Quantitative fluorescent microscopic methods, such as fluorescence life time imaging or pH ratiometry, can be employed to visualize pH in different microenvironments of dental biofilms. pH ratiometry exploits a pH-dependent shift in the fluorescent emission of pH-sensitive dyes. Calculation of the emission ratio at two different wavelengths allows determining local pH in microscopic images, irrespective of the concentration of the dye. Contrary to microelectrodes the technique allows monitoring both vertical and horizontal pH gradients in real-time without mechanically disturbing the biofilm. However, care must be taken to differentiate accurately between extra- and intracellular compartments of the biofilm. Here, the ratiometric dye, seminaphthorhodafluor-4F 5-(and-6) carboxylic acid (C-SNARF-4) is employed to monitor extracellular pH in in vivo grown dental biofilms of unknown species composition. Upon exposure to glucose the dye is up-concentrated inside all bacterial cells in the biofilms; it is thus used both as a universal bacterial stain and as a marker of extracellular pH. After confocal microscopic image acquisition, the bacterial biomass is removed from all pictures using digital image analysis software, which permits to exclusively calculate extracellular pH. pH ratiometry with the ratiometric dye is well-suited to study extracellular pH in thin biofilms of up to 75 µm thickness, but is limited to the pH range between 4.5 and 7.0.

  14. Time dependence of the pH of rain

    Treesearch

    John A. Kadlecek; Volkar A. Mohnen

    1976-01-01

    Standard procedures for determining the pH of rain samples usually involve substantial delays from the time of rainfall to the time of analysis. This assumes that no change in pH occurs during the storage period. We have found that this is not always true. We have determined that individual rain water samples possess a time dependent pH which can be correlated with the...

  15. Design of PH sensor signal acquisition and display system

    NASA Astrophysics Data System (ADS)

    Qian, Huifa; Zhang, Quanzhu; Deng, Yonghong

    2017-06-01

    With the continuous development of sensor manufacturing technology, how to better deal with the signal is particularly important. PH value of the sensor voltage generated by the signal as a signal, through the MCU acquisition A / D conversion, and ultimately through the digital display of its PH value. The system uses hardware and software to achieve the results obtained with the high-precision PH meter to strive to improve the accuracy and reduce error.

  16. Chapter A6. Section 6.4. pH

    USGS Publications Warehouse

    Wilde, Franceska D.; Busenberg, Eurybiades; Radtke, Dean B.

    2006-01-01

    Measurement of pH is critical to the understanding of the viability and vulnerability of environmental waters and is considered a master variable in determining the aqueous geochemistry of an aqueous system. pH is a measure that represents the hydrogen-ion concentration (activity) of a solution. This section of the National Field Manual (NFM) describes U.S. Geological Survey (USGS) guidance and protocols for measurement of pH in ground and surface waters.

  17. Quantum dot photoluminescence lifetime-based pH nanosensor.

    PubMed

    Ruedas-Rama, Maria J; Orte, Angel; Hall, Elizabeth A H; Alvarez-Pez, Jose M; Talavera, Eva M

    2011-03-14

    The first CdSe/ZnS quantum dot photoluminescence lifetime-based pH nanosensor has been developed. The average lifetime of mercaptopropionic acid-capped QD nanosensors showed a linear response in the pH range of 5.2-6.9. These nanosensors have been satisfactorily applied for pH estimation in simulated intracellular media, with high sensitivity and high selectivity toward most of the intracellular components.

  18. Update to Millstone 3 elevated pH tests

    SciTech Connect

    Bergmann, C.A.; Perock, J.D.; Hudson, M.J.B.; King, R.W.; Macklin, S.

    1995-03-01

    In view of the potential radiological benefits of elevated coolant pH operation, Northwest Utilities (NU), in support of an EPRI-Westinghouse program, agreed to operate the Millstone 3 plant at the start of its second fuel cycle as a demonstration of the effect of elevated coolant pH on out-of-core radiation fields. Operating with an elevated pH is defined as operating with an average lithium concentration of 3.35 ppm, until reaching an end of cycle pH of 7.2 or 7.4. The plant operated during its second and third cycles with an elevated coolant pH. The end of cycle pH during the second cycle was 7.4, and 7.2 during the third cycle. (During the first cycle, operation was with a coordinated pH of 7.0). Evaluation of the dose rate trends in Millstone 3 after two cycles of elevated coolant pH operation concluded that an elevated coolant pH resulted in a 15 percent lower component dose rate compared to other plants that operated with coordinated pH 6.9. However, due to a possible increase in fuel clad corrosion, operation during cycle 4 was restricted to pH 6.9 coordinated chemistry, with the exception of the last two months during which the pH increased to 7.35. At the end of cycle 4 (EOC4), there was a greater increase in component and crud trap dose rates than expected. This paper reviews the radiological trends in the plant and discusses the potential causes for the increase in the dose rates at EOC4.

  19. Determining pH of strip-mine spoils

    Treesearch

    W. A. Berg

    1969-01-01

    Results with the LaMotte-Morgan method for determining soil pH-or the solution modification of this method-usually agreed fairly well with the results from using a pH meter, the recognized standard. Results obtained with the Soiltex and Hellige-Truog methods often deviated somewhat from the pH meter readings; and the Hydrion papers and the Kelway pH tester often gave...

  20. PH Dependent Interactions between Aqueous Iodide Ion and Selected Oxidizers.

    DTIC Science & Technology

    1985-12-06

    between the oxidizers oeroxydisultte, peroxide. percarbonate, and perborate ions and aqueous iodide have been measured at pH 1. 4. 7, 9. Reactions were... Perborate and percarbonate are salts with "hydrogen peroxide of crystallization" (see formulae listed in Table i). These salts appear to release this...between hydrogen peroxide and iodide are highly pH dependent. These materials react very slowly, or not at all, at pH 49. 2). Perborate and percarbonate are

  1. Field measurement of alkalinity and pH

    USGS Publications Warehouse

    Barnes, Ivan

    1964-01-01

    The behavior of electrometric pH equipment under field conditions departs from the behavior predicted from Nernst's law. The response is a linear function of pH, and hence measured pH values may be corrected to true pH if the instrument is calibrated with two reference solutions for each measurement. Alkalinity titrations may also be made in terms of true pH. Standard methods, such as colorimetric titrations, were rejected as unreliable or too cumbersome for rapid field use. The true pH of the end point of the alkalinity titration as a function of temperature, ionic strength, and total alkalinity has been calculated. Total alkalinity in potable waters is the most important factor influencing the end point pH, which varies from 5.38 (0 ? C, 5 ppm (parts per million) HC0a-) to 4.32 (300 ppm HC0a-,35 ? C), for the ranges of variables considered. With proper precautions, the pH may be determined to =i:0.02 pH and the alkalinity to =i:0.6 ppm HCO3- for many naturally occurring bodies of fresh water.

  2. pH inactivation of phosphofructokinase arrests postmortem glycolysis.

    PubMed

    England, Eric M; Matarneh, Sulaiman K; Scheffler, Tracy L; Wachet, Céline; Gerrard, David E

    2014-12-01

    Fresh meat quality development is influenced by pH decline that results from muscle glycolyzing energy substrates postmortem. The exact reason why glycolysis stops in the presence of residual glycogen remains unclear. We hypothesized that a critical glycolytic enzyme loses activity near the ultimate pH of meat. Porcine longissimus muscle samples were subjected to an in vitro system that mimics postmortem anaerobic metabolism at buffered pH values (7.0, 6.5, 6.0, 5.5 or 5.0). At pH7.0, 6.5, and 6.0, glycogenolysis and glycolysis proceeded normally while pH5.5 stopped lactate formation. Additional experimentation indicated that phosphofructokinase lost activity at pH5.5 while all other glycolytic enzymes remained active. A similar inactivation of phosphofructokinase was observed when using chicken and beef muscle. Elevated temperature hastened pH decline and phosphofructokinase activity loss. Thus, pH inactivates phosphofructokinase and arrests postmortem glycolysis, which may explain the similar ultimate pH across meat of different species.

  3. Nanosensor aided photoacoustic measurement of pH in vivo

    NASA Astrophysics Data System (ADS)

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

    2013-03-01

    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.

  4. Molecular aspects of bacterial pH sensing and homeostasis

    PubMed Central

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

    2011-01-01

    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. PMID:21464825

  5. Fiber Bragg Grating Based pH Sensor

    NASA Astrophysics Data System (ADS)

    Yulianti, Ian; Sahmah, Abu; Supa'at, M.; Idrus, M.; Kassim, Norazan M.; Al-hetar, Abdulaziz M.

    2011-05-01

    This paper demonstrates the modeling of pH sensor based on pH sensitive hydrogel coated FBG. The modeling was done by simulating the hydrogel swelling behavior, then calculating the strain induced by hydrogel expansion. Meshless numerical method was adopted to solve the Poison Nernst Planck equation coupled to mechanical equation to simulate the hydrogel swelling. The strain induced in the FBG due to mechanical expansion of hydrogel was calculated analytically. Strain of more than 10 μɛ was obtained at pH> 5. At pH of 5, λB shift of more than 10 pm was achieved.

  6. Cytoplasmic pH and human erythrocyte shape.

    PubMed Central

    Gedde, M M; Davis, D K; Huestis, W H

    1997-01-01

    Altered external pH transforms human erythrocytes from discocytes to stomatocytes (low pH) or echinocytes (high pH). The mechanism of this transformation is unknown. The preceding companion study (Gedde and Huestis) demonstrated that these shape changes are not mediated by changes in membrane potential, as has been reported. The aim of this study was to identify the physiological properties that mediate this shape change. Red cells were placed in a wide range of physiological states by manipulation of buffer pH, chloride concentration, and osmolality. Morphology and four potential predictor properties (cell pH, membrane potential, cell water, and cell chloride concentration) were assayed. Analysis of the data set by stratification and nonlinear multivariate modeling showed that change in neither cell water nor cell chloride altered the morphology of normal pH cells. In contrast, change in cell pH caused shape change in normal-range membrane potential and cell water cells. The results show that change in cytoplasmic pH is both necessary and sufficient for the shape changes of human erythrocytes equilibrated in altered pH environments. PMID:9138569

  7. Temporal and spatial variability of rainfall pH

    Treesearch

    Richard G. Semonin

    1977-01-01

    The distribution of average rainwater pH over an area of 1,800 km² containing 81 collectors was determined from 25 storm events. The areal average of the data was pH 4.9, with a range of values from 4.3 to 6.8. A single storm event was studied to determine the change of pH as a function of time. The initial rain was pH 7.1, decreasing to 4.1. An excellent...

  8. Quantitative pH assessment of small-volume samples using a universal pH indicator.

    PubMed

    Brown, Jeffrey D; Bell, Nathaniel; Li, Victoria; Cantrell, Kevin

    2014-10-01

    We developed a hue-based pH determination method to analyze digital images of samples in a 384-well plate after the addition of a universal pH indicator. The standard error of calibration for 69 pH standards was 0.078 pH units, and no sample gave an error greater than 0.23 units. We then used in-solution isoelectric focusing to determine the isoelectric point of Wnt3A protein in conditioned medium and after purification and applied the described method to assess the pH of these small-volume samples. End users may access our standard to assay the pH of their own samples with no additional calibration. Copyright © 2014 Elsevier Inc. All rights reserved.

  9. Extracellular pH modulates GABAergic neurotransmission in rat hypothalamus.

    PubMed

    Chen, Z L; Huang, R Q

    2014-06-20

    Changes in extracellular pH have a modulatory effect on GABAA receptor function. It has been reported that pH sensitivity of the GABA receptor is dependent on subunit composition and GABA concentration. Most of previous investigations focused on GABA-evoked currents, which only reflect the postsynaptic receptors. The physiological relevance of pH modulation of GABAergic neurotransmission is not fully elucidated. In the present studies, we examined the influence of extracellular pH on the GABAA receptor-mediated inhibitory neurotransmission in rat hypothalamic neurons. The inhibitory postsynaptic currents (IPSCs), tonic currents, and the GABA-evoked currents were recorded with whole-cell patch techniques on the hypothalamic slices from Sprague-Dawley rats at 15-26 postnatal days. The amplitude and frequency of spontaneous GABA IPSCs were significantly increased while the external pH was changed from 7.3 to 8.4. In the acidic pH (6.4), the spontaneous GABA IPSCs were reduced in amplitude and frequency. The pH induced changes in miniature GABA IPSCs (mIPSCs) similar to that in spontaneous IPSCs. The pH effect on the postsynaptic GABA receptors was assessed with exogenously applied varying concentrations of GABA. The tonic currents and the currents evoked by sub-saturating concentration of GABA ([GABA]) (10 μM) were inhibited by acidic pH and potentiated by alkaline pH. In contrast, the currents evoked by saturating [GABA] (1mM) were not affected by pH changes. We also investigated the influence of pH buffers and buffering capacity on pH sensitivity of GABAA receptors on human recombinant α1β2γ2 GABAA receptors stably expressed in HEK 293 cells. The pH influence on GABAA receptors was similar in HEPES- and MES-buffered media, and not dependent on protonated buffers, suggesting that the observed pH effect on GABA response is a specific consequence of changes in extracellular protons. Our data suggest that the hydrogen ions suppress the GABAergic neurotransmission

  10. The Semen pH Affects Sperm Motility and Capacitation.

    PubMed

    Zhou, Ji; Chen, Li; Li, Jie; Li, Hongjun; Hong, Zhiwei; Xie, Min; Chen, Shengrong; Yao, Bing

    2015-01-01

    As the chemical environment of semen can have a profound effect on sperm quality, we examined the effect of pH on the motility, viability and capacitation of human sperm. The sperm in this study was collected from healthy males to avoid interference from other factors. The spermatozoa cultured in sperm nutrition solution at pH 5.2, 6.2, 7.2 and 8.2 were analyzed for sperm total motility, progressive motility (PR), hypo-osmotic swelling (HOS) rate, and sperm penetration. Our results showed that these parameters were similar in pH 7.2 and 8.2 sperm nutrition solutions, but decreased in pH 5.2 and 6.2 solutions. The HOS rate exhibited positive correlation with the sperm total motility and PR. In addition, the sperm Na(+)/K(+)-ATPase activity at different pHs was measured, and the enzyme activity was significantly lower in pH 5.2 and 6.2 media, comparing with that in pH 8.2 and pH 7.2 solutions. Using flow cytometry (FCM) and laser confocal scanning microscopy (LCSM) analysis, the intracellular Ca2(+ )concentrations of sperm cultured in sperm capacitation solution at pH 5.2, 6.2, 7.2 and 8.2 were determined. Compared with that at pH 7.2, the mean fluorescence intensity of sperm in pH 5.2 and 6.2 media decreased significantly, while that of pH 8.2 group showed no difference. Our results suggested that the declined Na(+)/K(+)-ATPase activity at acidic pHs result in decreased sperm movement and capacitation, which could be one of the mechanisms of male infertility.

  11. The pH of beverages in the United States.

    PubMed

    Reddy, Avanija; Norris, Don F; Momeni, Stephanie S; Waldo, Belinda; Ruby, John D

    2016-04-01

    Dental erosion is the chemical dissolution of tooth structure in the absence of bacteria when the environment is acidic (pH < 4.0). Research indicates that low pH is the primary determinant of a beverage's erosive potential. In addition, citrate chelation of calcium ions may contribute to erosion at higher pH. The authors of this study determined the erosive potential measured by the pH of commercially available beverages in the United States. The authors purchased 379 beverages from stores in Birmingham, Alabama, and categorized them (for example, juices, sodas, flavored waters, teas, and energy drinks) and assessed their pH. They used a pH meter to measure the pH of each beverage in triplicate immediately after it was opened at a temperature of 25°C. The authors recorded the pH data as mean (standard deviation). Most (93%, 354 of 379) beverages had a pH of less than 4.0, and 7% (25 of 379) had a pH of 4.0 or more. Relative beverage erosivity zones based on studies of apatite solubility in acid indicated that 39% (149 of 379) of the beverages tested in this study were considered extremely erosive (pH < 3.0), 54% (205 of 379) were considered erosive (pH 3.0 to 3.99), and 7% (25 of 379) were considered minimally erosive (pH ≥ 4.0). This comprehensive pH assessment of commercially available beverages in the United States found that most are potentially erosive to the dentition. This study's findings provide dental clinicians and auxiliaries with information regarding the erosive potential of commercially available beverages. Specific dietary recommendations for the prevention of dental erosion may now be developed based on the patient's history of beverage consumption. Copyright © 2016 American Dental Association. Published by Elsevier Inc. All rights reserved.

  12. Notes on the Measurement of pH Values

    SciTech Connect

    Carranza, R M; Rebak, R B

    2005-05-05

    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.

  13. Mapping Soil pH Buffering Capacity of Selected Fields

    NASA Technical Reports Server (NTRS)

    Weaver, A. R.; Kissel, D. E.; Chen, F.; West, L. T.; Adkins, W.; Rickman, D.; Luvall, J. C.

    2003-01-01

    Soil pH buffering capacity, since it varies spatially within crop production fields, may be used to define sampling zones to assess lime requirement, or for modeling changes in soil pH when acid forming fertilizers or manures are added to a field. Our objective was to develop a procedure to map this soil property. One hundred thirty six soil samples (0 to 15 cm depth) from three Georgia Coastal Plain fields were titrated with calcium hydroxide to characterize differences in pH buffering capacity of the soils. Since the relationship between soil pH and added calcium hydroxide was approximately linear for all samples up to pH 6.5, the slope values of these linear relationships for all soils were regressed on the organic C and clay contents of the 136 soil samples using multiple linear regression. The equation that fit the data best was b (slope of pH vs. lime added) = 0.00029 - 0.00003 * % clay + 0.00135 * % O/C, r(exp 2) = 0.68. This equation was applied within geographic information system (GIS) software to create maps of soil pH buffering capacity for the three fields. When the mapped values of the pH buffering capacity were compared with measured values for a total of 18 locations in the three fields, there was good general agreement. A regression of directly measured pH buffering capacities on mapped pH buffering capacities at the field locations for these samples gave an r(exp 2) of 0.88 with a slope of 1.04 for a group of soils that varied approximately tenfold in their pH buffering capacities.

  14. Biomedical PhD education--an international perspective.

    PubMed

    Mulvany, Michael J

    2013-05-01

    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.

  15. Mapping Soil pH Buffering Capacity of Selected Fields

    NASA Technical Reports Server (NTRS)

    Weaver, A. R.; Kissel, D. E.; Chen, F.; West, L. T.; Adkins, W.; Rickman, D.; Luvall, J. C.

    2003-01-01

    Soil pH buffering capacity, since it varies spatially within crop production fields, may be used to define sampling zones to assess lime requirement, or for modeling changes in soil pH when acid forming fertilizers or manures are added to a field. Our objective was to develop a procedure to map this soil property. One hundred thirty six soil samples (0 to 15 cm depth) from three Georgia Coastal Plain fields were titrated with calcium hydroxide to characterize differences in pH buffering capacity of the soils. Since the relationship between soil pH and added calcium hydroxide was approximately linear for all samples up to pH 6.5, the slope values of these linear relationships for all soils were regressed on the organic C and clay contents of the 136 soil samples using multiple linear regression. The equation that fit the data best was b (slope of pH vs. lime added) = 0.00029 - 0.00003 * % clay + 0.00135 * % O/C, r(exp 2) = 0.68. This equation was applied within geographic information system (GIS) software to create maps of soil pH buffering capacity for the three fields. When the mapped values of the pH buffering capacity were compared with measured values for a total of 18 locations in the three fields, there was good general agreement. A regression of directly measured pH buffering capacities on mapped pH buffering capacities at the field locations for these samples gave an r(exp 2) of 0.88 with a slope of 1.04 for a group of soils that varied approximately tenfold in their pH buffering capacities.

  16. High-Resolution FTIR Study of the PH Stretching Bands ν 1 and ν 5 of PH 2F and PH 2Cl

    NASA Astrophysics Data System (ADS)

    Beckers, H.; Burger, H.; Paplewski, M.

    1995-06-01

    The FTIR spectra in the ν1 and ν5 (PH stretching) regions of the short-lived molecules PH2F and PH2Cl have been recorded with a resolution of 5.5 × 10-3 cm-1. The rovibrational analysis of the A/C- and B-type bands yielded excited state parameters, and relative transition moments of the ν1 and ν5 bands as well as the μA:μC ratio of ν1 were estimated by band contour simulations. The band centers were determined: PH2F, ν1 2283.11950(4), ν5 2286.97185(4); and PH235CI, ν1 2203.43762(4), ν5 2309.67696(4) cm-1. In PH2F, weak c-type Coriolis resonance effects with ζc1,5 = 0.0120 were found to affect the Ka = 1 and Ka = 0 levels of ν1 and ν5, respectively. The experimental results are in good agreement with previously reported predictions from ab initio harmonic and anharmonic force fields.

  17. Microscale pH Titrations Using an Automatic Pipet.

    ERIC Educational Resources Information Center

    Flint, Edward B.; Kortz, Carrie L.; Taylor, Max A.

    2002-01-01

    Presents a microscale pH titration technique that utilizes an automatic pipet. A small aliquot (1-5 mL) of the analyte solution is titrated with repeated additions of titrant, and the pH is determined after each delivery. The equivalence point is determined graphically by either the second derivative method or a Gran plot. The pipet can be…

  18. Sugar sensing based on induced pH changes.

    PubMed

    Kim, Youngmi; Hilderbrand, Scott A; Weissleder, Ralph; Tung, Ching-Hsuan

    2007-06-14

    A sensory assembly consisting of a pH sensitive NIR dye and an arylboronic acid shows ratiometric absorption changes with increased fluorescence intensity upon addition of sugar in aqueous media; this demonstrates a new signal transduction mechanism for the detection of sugar based on pH changes induced in the microenvironment of the sensory assembly.

  19. The Early Development of Electronic pH Meters

    ERIC Educational Resources Information Center

    Hines, Wallis G.; de Levie, Robert

    2010-01-01

    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…

  20. A Renaissance in Engineering PhD Education

    ERIC Educational Resources Information Center

    Akay, Adnan

    2008-01-01

    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 education…

  1. Traceable Reference Standards for Seawater pH

    NASA Astrophysics Data System (ADS)

    Waters, J. F.; Easley, R. A.; Pratt, K. W.

    2016-02-01

    Ocean acidification is primarily driven by increased anthropogenic atmospheric CO2. Our present understanding of the effects of an increasingly acidic ocean is largely founded on metrologically unlinked collections of diverse environmental observations and laboratory studies with vast temporal and geographic extents. To understand these complex implications better, it is critical to establish rigorous metrological traceability in seawater carbon-system measurements and to develop a comprehensive evaluation of the measurement uncertainty. This poster communicates the development of a NIST reference material to extend metrological traceability to measurements of seawater pH. Traceability of seawater pH to the International System of Units (SI) is achieved through a multi-standard suite of synthetic seawater buffers certified using primary pH metrology (Harned cell measurements). The primary measurements of these buffer materials extend to lower salinities and pH values than those from previous investigations. The lifetime of these liquid buffers (months) is too short for use as a reference material (years). To leverage the measurement to a stable calibrator, a purified batch of colorimetric pH indicator is characterized spectrophotometrically using these same primary buffers. Use of a multi-standard suite of primary buffers traceably links the solid reference material to the primary pH measurements in a manner compliant with current practice for calibration of secondary pH measurements. An uncertainty analysis compliant with presently accepted metrological guidelines for pH determined with the reference material is presented.

  2. Evanescent-wave spectroscopic fiber optic pH sensor

    NASA Astrophysics Data System (ADS)

    Egami, C.; Takeda, K.; Isai, M.; Ogita, M.

    1996-02-01

    We demonstrate a new type of fiber optic pH sensor, which is the application of evanescent-wave spectroscopic technique. A methyl red (MR)-doped-poly(methyl methacrylate) (PMMA) film that coated as part of cladding does function as a pH sensor probe. In this system MR doped in PMMA is used as indicator dye for pH measurement. The absorption spectrum shift in wavelength of indicator dye enables us to get the pH value. The sensor probe is immersed in water solution containing a small proportion of acetic acid over the wide pH range of 5.0 to 7.0. The chemical interaction between MR in sensor probe and hydrogen ion in the water solution causes a change in the dipole moment of MR, that is, the absorption spectrum macroscopically. The evanescent-wave spectroscopic technique provides the measurement of the absorption spectrum shift over a broad range of visible wavelength. The result of experiment was that MR absorption spectrum shifted by 40 nm every increase of 1.0 in pH. The small change in the pH value can be sensed as a large wavelength shift of pH indicator absorption spectrum.

  3. Research Collaboration and Commercialization: The PhD Candidate Perspective

    ERIC Educational Resources Information Center

    Dooley, Lawrence; Kenny, Breda

    2015-01-01

    This paper explores PhD students' perceptions of their entrepreneurial and commercial capabilities, their attitude towards university supports and the extent to which they engage in external collaboration. The study concentrated on current PhD researchers at one university in Ireland as a unit of analysis and provides encouraging evidence from the…

  4. Frequently Asked Questions for Parents of Children with PH

    MedlinePlus

    ... symptoms and treatment. How will PH affect my child’s growth and development? Most children with idiopathic pulmonary hypertension have normal growth and development; however, when it is associated with another medical ... the PH get worse as my child gets older? There is no known cure for ...

  5. The Undergraduate Origins of PhD Economists Revisited

    ERIC Educational Resources Information Center

    Stock, Wendy A.; Siegfried, John J.

    2015-01-01

    The authors update prior analyses of the undergraduate origins of individuals who earn a PhD in economics in the United States. They include the list of the top institutions worldwide graduating the largest number of undergraduates who subsequently earn an economics PhD from a U.S. university and lists of American institutions with the largest…

  6. Earth & Space Science PhDs, Class of 2001.

    ERIC Educational Resources Information Center

    Claudy, Nicholas; Henly, Megan; Migdalski, Chet

    This study documents the employment patterns and demographic characteristics of recent PhDs in earth and space science. It summarizes the latest annual survey of recent earth and space science PhDs conducted by the American Geological Institute, the American Geophysical Union, and the Statistical Research Center of the American Institute of…

  7. The PhD Viva: A Space for Academic Development

    ERIC Educational Resources Information Center

    Share, Michelle

    2016-01-01

    This study examined the viva experiences of 87 social science PhD graduates from three Irish higher education institutions through a questionnaire that assessed outcome, preparation, conduct and post-viva. The majority were awarded their PhD with minor corrections, considered their viva as a summative assessment, and emphasised its purpose as…

  8. International Mobility of French Ph.D.s

    ERIC Educational Resources Information Center

    Bonnard, Claire; Calmand, Julien; Giret, Jean-François

    2017-01-01

    This research investigates the determinants of international mobility of Ph.D.s upon graduation. It is based on a survey of 400 young Ph.D.s who graduated in France between 2003 and 2008, half of whom were still abroad more than six years after graduating. The impacts of personal, occupational and scientific characteristics on the successive…

  9. Mapping bark pH to better understand the cortisphere

    NASA Astrophysics Data System (ADS)

    Levia, D. F., Jr.; Köhler, S.; Jungkunst, H. F.; Gerold, G.

    2016-12-01

    The biogeochemistry of the cortisphere is poorly understood, despite the fact that a large variety of microbes, epiphytes, and insects live on, within, and just beneath corticular surfaces. Bark pH is a critical parameter that partially controls the chemodynamics of the cortisphere and its habitability by bark dwelling organisms as well as the chemistry of throughfall and stemflow. This presentation articulates, tests, and validates a method to accurately determine bark pH in situ. We employed agar-agar panels, embedded with a pH marker, to determine the spatiality of bark pH on cacao trees in Indonesia. In contrast to existing ex situ methods, we were able to record spatial differences in bark pH. In particular, bark pH was observed to fluctuate in relation to both morphological features on the bark, possibly corresponding to preferential flowpaths of stemflow, and epiphytic coverage. Due to its simplicity and economical nature, our method may be attractive to a variety of researchers interested in bark pH, its spatial variability, influence on stemflow chemistry, and its effect on organisms dwelling in the cortipshere. Publication note: This presentation is based on the following article: Köhler, S., Levia, D.F., Jungkunst, H.F. and Gerold, G. 2015. An in situ method to measure and map bark pH. Journal of Wood Chemistry and Technology 35(6): 438-449. [DOI: 10.1080/02773813.2015.1025285

  10. PhDs in Australia, from the Beginning

    ERIC Educational Resources Information Center

    Dobson, Ian R.

    2012-01-01

    The Australian PhD is a relatively recent phenomenon, the first three being awarded in 1948. Before that, most Australian scholars typically went to Britain (predominantly) or the USA to undertake their doctoral studies. The aim of this research note is to provide a brief statistical history of the Australian PhD, noting changes over time between…

  11. Tracking the PhD Students' Daily Computer Use

    ERIC Educational Resources Information Center

    Sim, Kwong Nui; van der Meer, Jacques

    2015-01-01

    This study investigated PhD students' computer activities in their daily research practice. Software that tracks computer usage (Manic Time) was installed on the computers of nine PhD students, who were at their early, mid and final stage in doing their doctoral research in four different discipline areas (Commerce, Humanities, Health Sciences and…

  12. Consideration of Factors Affecting Strip Effluent PH and Sodium Content

    SciTech Connect

    Peters, T.

    2015-07-29

    A number of factors were investigated to determine possible reasons for why the Strip Effluent (SE) can sometimes have higher than expected pH values and/or sodium content, both of which have prescribed limits. All of the factors likely have some impact on the pH values and Na content.

  13. Variation of ocean pH in the Indonesia waters

    NASA Astrophysics Data System (ADS)

    Putri, Mutiara Rachmat; Setiawan, Agus; Safitri, Mediana

    2015-09-01

    The variation of ocean acidity (pH) in the Indonesia waters is strongly influenced by monsoon. Since the climate change tends to potentially change monsoonal variation over the Indonesian region, it will give also implication to the ocean pH variation. Moreover, changes of ocean pH will give effects to the marine lifes and their environment. In order to investigate this issue, we tried to calculate monthly variation of sea surface pH in the Indonesia waters based on monthly average temperature and salinity over past 18 years data. Temperature and salinity data used in this study were taken from the hydrodynamic model of Hamburg Shelf Ocean Model (HAMSOM), while alkalinity and dissolved inorganic carbon (DIC) were from World Ocean Atlas 2009 (WOA 2009). Algorithm from Ocean Carbon Model Intercomparison Project-version.3 (OCMIP-3) was used to calculate the pH. The estimation results indicate that pH variation in the Indonesia waters changes insignificantly over 18 years. El Nino Southern Oscillation (ENSO) and Indian Ocean Dipole (IOD) contribute to physical changes of seawater, but did not affect the pH significantly. The average pH of seawater is higher during northwest monsoon than during southeast monsoon.

  14. Can Community Colleges Survive the PhD Glut?

    ERIC Educational Resources Information Center

    Taylor, Anita

    The impact of the current employment situation on hiring faculty for community college teaching is examined. It is concluded that prospects for improving the quality of learning in community colleges are not particularly enhanced by the apparently growing surplus of new PhDs in our field. On the contrary, it is suggested that hiring PhDs for…

  15. The Importance of Having a Ph.D., Career Advice

    USDA-ARS?s Scientific Manuscript database

    A presentation on the importance of having a PhD to motivate Initiative to Maximize Student Diversity Program (IMSD) undergrads towards conducting research, pursuing careers in the biomedical field, applying to grad school, and getting a Ph.D., based upon ARS scientist's experiences as a student, a ...

  16. The Early Development of Electronic pH Meters

    ERIC Educational Resources Information Center

    Hines, Wallis G.; de Levie, Robert

    2010-01-01

    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…

  17. International Mobility of French Ph.D.s

    ERIC Educational Resources Information Center

    Bonnard, Claire; Calmand, Julien; Giret, Jean-François

    2017-01-01

    This research investigates the determinants of international mobility of Ph.D.s upon graduation. It is based on a survey of 400 young Ph.D.s who graduated in France between 2003 and 2008, half of whom were still abroad more than six years after graduating. The impacts of personal, occupational and scientific characteristics on the successive…

  18. The PhD Viva: A Space for Academic Development

    ERIC Educational Resources Information Center

    Share, Michelle

    2016-01-01

    This study examined the viva experiences of 87 social science PhD graduates from three Irish higher education institutions through a questionnaire that assessed outcome, preparation, conduct and post-viva. The majority were awarded their PhD with minor corrections, considered their viva as a summative assessment, and emphasised its purpose as…

  19. The Undergraduate Origins of PhD Economists Revisited

    ERIC Educational Resources Information Center

    Stock, Wendy A.; Siegfried, John J.

    2015-01-01

    The authors update prior analyses of the undergraduate origins of individuals who earn a PhD in economics in the United States. They include the list of the top institutions worldwide graduating the largest number of undergraduates who subsequently earn an economics PhD from a U.S. university and lists of American institutions with the largest…

  20. Effect of pH on biological phosphorus uptake.

    PubMed

    Serralta, J; Ferrer, J; Borrás, L; Seco, A

    2006-12-05

    An anaerobic aerobic laboratory scale sequencing batch reactor (SBR) was operated to study the effect of pH on enhanced biological phosphorus removal. Seven steady states were achieved under different operating conditions. In all of them, a slight variation in the pH value was observed during anaerobic phase. However, pH rose significantly during aerobic phase. The increase observed was due to phosphorus uptake and carbon dioxide stripping. When pH was higher than 8.2-8.25 the phosphorus uptake rate clearly decreased. The capability of Activated Sludge Model No. 2d (ASM2d) and Biological Nutrient Removal Model No. 1 (BNRM1) to simulate experimental results was evaluated. Both models successfully characterized the enhanced biological phosphorus removal performance of the SBR. Furthermore, BNRM1 also reproduced the pH variations observed and the decrease in the phosphorus uptake rate. This model includes a switch function in the kinetic expressions to represent the pH inhibition in biological processes. The pH inhibition constants related to polyphosphate storage process were obtained by adjusting model predictions to measured phosphorus concentrations. On the other hand, pH inhibition should be included in ASM2d to accurately simulate experimental phosphorus evolution observed in an A/O SBR.

  1. Research Collaboration and Commercialization: The PhD Candidate Perspective

    ERIC Educational Resources Information Center

    Dooley, Lawrence; Kenny, Breda

    2015-01-01

    This paper explores PhD students' perceptions of their entrepreneurial and commercial capabilities, their attitude towards university supports and the extent to which they engage in external collaboration. The study concentrated on current PhD researchers at one university in Ireland as a unit of analysis and provides encouraging evidence from the…

  2. Factors associated with ruminal pH at herd level.

    PubMed

    Geishauser, T; Linhart, N; Neidl, A; Reimann, A

    2012-08-01

    The objective of this study was to evaluate factors associated with ruminal pH at herd level. Four hundred and thirty-two cows of a Thuringian dairy herd were sampled before claw trimming using a rumen fluid scoop. Volume and pH of the rumen sample were measured, and lactation number, percentage of concentrates in the ration, days in milk (DIM), time of day, and daily milk yield were recorded. Rumen sampling was successful in 99.8% of the cows. The average sample volume was 25 mL. Rumen sample pH decreased with increasing percentage of concentrates in the ration. Ruminal pH decreased from calving to 77 DIM, and grew subsequently to 330 DIM. During the day, rumen pH followed a sinus curve, with maxima in the morning (0915 h) and afternoon (1533 h), and a minimum around noon (1227 h). Ruminal pH decreased with increasing daily milk yield. Lactation number interacted with daily milk yield on rumen pH. The percentage of concentrates in the ration, DIM, time of day, and daily milk yield were significant factors affecting ruminal pH at the herd level.

  3. Rethinking PhD Learning Incorporating Communities of Practice

    ERIC Educational Resources Information Center

    Shacham, Miri; Od-Cohen, Yehudit

    2009-01-01

    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 engagement…

  4. Ambulatory pH Monitoring: New Advances and Indications

    PubMed Central

    Lutsi, Brant

    2006-01-01

    Ambulatory pH monitoring is currently used to objectively demonstrate abnormal degrees of esophageal acid exposure in patients with suspected gastroesophageal reflux disease. The development of wireless pH capsule recording has improved the tolerability and increased the duration of pH recording. Use of symptom-reflux correlation measures and pH testing, combining periods off and on PPI therapy, serves to optimize the performance of conventional pH testing. On the other hand, devices that measure bile reflux as well as nonacid reflux (esophageal impedance testing) have broadened the definition of gastroesophageal reflux and present potential explanations for patients with continued symptoms despite high-dose PPI therapy. These advances and their current and future clinical applications are reviewed

  5. ['Sandwich PhD': considerations for a successful experience abroad].

    PubMed

    Salvetti, Marina de Goes; Bueno, Mariana; Gastaldo, Denise; Kimura, Amélia Fumiko; Pimenta, Cibele Andrucioli de Mattos

    2013-03-01

    International PhD internship, named "Sandwich PhD" in Brazil is an opportunity to improve research abilities, to become known in academic area and to establish and/or increase work opportunities in an international context. In this article, we describe key factors regarding the planning and development of the "Sandwich PhD" as experienced by professors and students involved in the collaboration between the School of Nursing, University of São Paulo and Lawrence S. Bloomberg Faculty of Nursing, University of Toronto, Canada. We also present the participation of PhD students' network as an alternative to the "Sandwich PhD". An international experience, when well-planned and developed correctly, promotes students' personal and professional development and favors the internationalization of Brazilian graduate programs and research groups.

  6. Tight Coupling of Astrocyte pH Dynamics to Epileptiform Activity Revealed by Genetically Encoded pH Sensors.

    PubMed

    Raimondo, Joseph V; Tomes, Hayley; Irkle, Agnese; Kay, Louise; Kellaway, Lauriston; Markram, Henry; Millar, Robert P; Akerman, Colin J

    2016-06-29

    Astrocytes can both sense and shape the evolution of neuronal network activity and are known to possess unique ion regulatory mechanisms. Here we explore the relationship between astrocytic intracellular pH dynamics and the synchronous network activity that occurs during seizure-like activity. By combining confocal and two-photon imaging of genetically encoded pH reporters with simultaneous electrophysiological recordings, we perform pH measurements in defined cell populations and relate these to ongoing network activity. This approach reveals marked differences in the intracellular pH dynamics between hippocampal astrocytes and neighboring pyramidal neurons in rodent in vitro models of epilepsy. With three different genetically encoded pH reporters, astrocytes are observed to alkalinize during epileptiform activity, whereas neurons are observed to acidify. In addition to the direction of pH change, the kinetics of epileptiform-associated intracellular pH transients are found to differ between the two cell types, with astrocytes displaying significantly more rapid changes in pH. The astrocytic alkalinization is shown to be highly correlated with astrocytic membrane potential changes during seizure-like events and mediated by an electrogenic Na(+)/HCO3 (-) cotransporter. Finally, comparisons across different cell-pair combinations reveal that astrocytic pH dynamics are more closely related to network activity than are neuronal pH dynamics. This work demonstrates that astrocytes exhibit distinct pH dynamics during periods of epileptiform activity, which has relevance to multiple processes including neurometabolic coupling and the control of network excitability. Dynamic changes in intracellular ion concentrations are central to the initiation and progression of epileptic seizures. However, it is not known how changes in intracellular H(+) concentration (ie, pH) differ between different cell types during seizures. Using recently developed pH-sensitive proteins, we

  7. Plant based dietary supplement increases urinary pH

    PubMed Central

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

    2008-01-01

    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. PMID:18990209

  8. 49 CFR 15.5 - Sensitive security information.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... infrastructure asset information. Any list identifying systems or assets, whether physical or virtual, so vital... privacy (including, but not limited to, information contained in any personnel, medical, or similar file... held by the Federal government concerning threats against transportation or transportation systems and...

  9. 49 CFR 15.5 - Sensitive security information.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... infrastructure asset information. Any list identifying systems or assets, whether physical or virtual, so vital... privacy (including, but not limited to, information contained in any personnel, medical, or similar file... held by the Federal government concerning threats against transportation or transportation systems and...

  10. 49 CFR 15.5 - Sensitive security information.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... infrastructure asset information. Any list identifying systems or assets, whether physical or virtual, so vital... privacy (including, but not limited to, information contained in any personnel, medical, or similar file... held by the Federal government concerning threats against transportation or transportation systems and...

  11. 47 CFR 15.5 - General conditions of operation.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ....5 General conditions of operation. (a) Persons operating intentional or unintentional radiators... intentional, unintentional, or incidental radiator is subject to the conditions that no harmful interference... radio station, by another intentional or unintentional radiator, by industrial, scientific and...

  12. 47 CFR 15.5 - General conditions of operation.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ....5 General conditions of operation. (a) Persons operating intentional or unintentional radiators... intentional, unintentional, or incidental radiator is subject to the conditions that no harmful interference... radio station, by another intentional or unintentional radiator, by industrial, scientific and...

  13. 47 CFR 15.5 - General conditions of operation.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ....5 General conditions of operation. (a) Persons operating intentional or unintentional radiators... intentional, unintentional, or incidental radiator is subject to the conditions that no harmful interference... radio station, by another intentional or unintentional radiator, by industrial, scientific and...

  14. 47 CFR 15.5 - General conditions of operation.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ....5 General conditions of operation. (a) Persons operating intentional or unintentional radiators... intentional, unintentional, or incidental radiator is subject to the conditions that no harmful interference... radio station, by another intentional or unintentional radiator, by industrial, scientific and...

  15. 47 CFR 15.5 - General conditions of operation.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ....5 General conditions of operation. (a) Persons operating intentional or unintentional radiators... intentional, unintentional, or incidental radiator is subject to the conditions that no harmful interference... radio station, by another intentional or unintentional radiator, by industrial, scientific and...

  16. 46 CFR 91.15-5 - Alternate compliance.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... this section, a list of authorized classification societies, including information for ordering copies of approved classification society rules and supplements, is available at Coast Guard Headquarters...-372-1925. Approved classification society rules and supplements are incorporated by reference into...

  17. 46 CFR 71.15-5 - Alternate compliance.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... list of authorized classification societies, including information for ordering copies of approved classification society rules and supplements, is available from Commandant (CG-ENG), 2100 2nd St. SW., Stop 7126, Washington, DC 20593-7126; telephone (202) 372-1372; or fax (202) 372-1925. Approved classification...

  18. 46 CFR 189.15-5 - Alternate compliance.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ..., a list of authorized classification societies, including information for ordering copies of approved classification society rules and supplements, is available from Commandant (CG-521), 2100 2nd St., SW., Stop 7126, Washington, DC 20593-7126; telephone (202) 372-1371; or fax (202) 372-1925. Approved classification...

  19. 46 CFR 189.15-5 - Alternate compliance.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ..., a list of authorized classification societies, including information for ordering copies of approved classification society rules and supplements, is available from Commandant (CG-ENG), Attn: Office of Design and...-7509; telephone 202-372-1371 or fax 202-372-1925. Approved classification society rules and...

  20. 46 CFR 71.15-5 - Alternate compliance.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... list of authorized classification societies, including information for ordering copies of approved classification society rules and supplements, is available at Coast Guard Headquarters. Contact Commandant (CG... classification society rules and supplements are incorporated by reference into 46 CFR 8.110(b)....

  1. 46 CFR 71.15-5 - Alternate compliance.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... list of authorized classification societies, including information for ordering copies of approved classification society rules and supplements, is available at Coast Guard Headquarters. Contact Commandant (CG... classification society rules and supplements are incorporated by reference into 46 CFR 8.110(b)....

  2. 46 CFR 91.15-5 - Alternate compliance.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... this section, a list of authorized classification societies, including information for ordering copies of approved classification society rules and supplements, is available from Commandant (CG-ENG), 2100.... Approved classification society rules and supplements are incorporated by reference into 46 CFR 8.110(b)....

  3. 46 CFR 189.15-5 - Alternate compliance.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ..., a list of authorized classification societies, including information for ordering copies of approved classification society rules and supplements, is available from Commandant (CG-ENG), Attn: Office of Design and...-7509; telephone 202-372-1371 or fax 202-372-1925. Approved classification society rules and...

  4. 46 CFR 71.15-5 - Alternate compliance.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... list of authorized classification societies, including information for ordering copies of approved classification society rules and supplements, is available from Commandant (CG-521), 2100 2nd St. SW., Stop 7126, Washington, DC 20593-7126; telephone (202) 372-1372; or fax (202) 372-1925. Approved classification...

  5. 46 CFR 56.15-5 - Fluid-conditioner fittings.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... greater than one-fourth of the ultimate tensile strength of the material for Class II systems and for all... of the burst pressure or produce a primary stress greater than one-fifth of the ultimate tensile strength of the material. The maximum allowable working pressure may be determined by— (A) Calculations...

  6. 46 CFR 56.15-5 - Fluid-conditioner fittings.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... greater than one-fourth of the ultimate tensile strength of the material for Class II systems and for all... of the burst pressure or produce a primary stress greater than one-fifth of the ultimate tensile strength of the material. The maximum allowable working pressure may be determined by— (A) Calculations...

  7. 46 CFR 56.15-5 - Fluid-conditioner fittings.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... greater than one-fourth of the ultimate tensile strength of the material for Class II systems and for all... of the burst pressure or produce a primary stress greater than one-fifth of the ultimate tensile strength of the material. The maximum allowable working pressure may be determined by— (A) Calculations...

  8. 46 CFR 56.15-5 - Fluid-conditioner fittings.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... greater than one-fourth of the ultimate tensile strength of the material for Class II systems and for all... of the burst pressure or produce a primary stress greater than one-fifth of the ultimate tensile strength of the material. The maximum allowable working pressure may be determined by— (A) Calculations...

  9. 46 CFR 56.15-5 - Fluid-conditioner fittings.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... greater than one-fourth of the ultimate tensile strength of the material for Class II systems and for all... of the burst pressure or produce a primary stress greater than one-fifth of the ultimate tensile strength of the material. The maximum allowable working pressure may be determined by— (A) Calculations...

  10. 49 CFR 15.5 - Sensitive security information.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... privacy (including, but not limited to, information contained in any personnel, medical, or similar file... specific locations or specific security procedures. Such information will be released after the relevant 12-month period, except that TSA will not release the specific gate or other location on an airport...

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

    NASA Technical Reports Server (NTRS)

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

    2002-01-01

    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. Copyright 2002 Wiley Periodicals, Inc.

  12. Thermal processing of acidified foods with pH 4.1 to pH 4.6

    USDA-ARS?s Scientific Manuscript database

    Shelf-stable acidified foods with a pH at or below 4.6 must be processed to achieve a 5-log reduction for vegetative bacterial pathogens. Published research does not exist to adequately support the Food and Drug Administration process filings for products with pH 4.1–4.6 or to define critical limits...

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

    NASA Technical Reports Server (NTRS)

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

    2002-01-01

    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. Copyright 2002 Wiley Periodicals, Inc.

  14. High-Resolution pH Imaging of Living Bacterial Cells To Detect Local pH Differences

    PubMed Central

    Morimoto, Yusuke V.; Kami-ike, Nobunori; Miyata, Tomoko; Kawamoto, Akihiro; Kato, Takayuki

    2016-01-01

    ABSTRACT Protons are utilized for various biological activities such as energy transduction and cell signaling. For construction of the bacterial flagellum, a type III export apparatus utilizes ATP and proton motive force to drive flagellar protein export, but the energy transduction mechanism remains unclear. Here, we have developed a high-resolution pH imaging system to measure local pH differences within living Salmonella enterica cells, especially in close proximity to the cytoplasmic membrane and the export apparatus. The local pH near the membrane was ca. 0.2 pH unit higher than the bulk cytoplasmic pH. However, the local pH near the export apparatus was ca. 0.1 pH unit lower than that near the membrane. This drop of local pH depended on the activities of both transmembrane export components and FliI ATPase. We propose that the export apparatus acts as an H+/protein antiporter to couple ATP hydrolysis with H+ flow to drive protein export. PMID:27923921

  15. Physiological pH. Effects on posthypoxic proximal tubular injury.

    PubMed

    Zager, R A; Schimpf, B A; Gmur, D J

    1993-04-01

    After O2 deprivation, tissue acidosis rapidly self-corrects. This study assessed the effect of this pH correction on the induction, and pathways, of posthypoxic proximal tubular injury. In addition, ways to prevent the resultant injury were explored. Isolated rat proximal tubular segments (PTSs) were subjected to hypoxia/reoxygenation (50/30 or 30/50 minutes) under the following incubation conditions: 1) continuous pH 7.4, 2) continuous pH 6.8, or 3) hypoxia at pH 6.8 and reoxygenation at pH 7.4 (NaHCO3 or Tris base addition). Continuously oxygenated PTSs maintained under these same pH conditions served as controls. Lethal cell injury was assessed by lactate dehydrogenase (LDH) release. pH effects on several purported pathways of hypoxia/reoxygenation injury were also assessed (ATP depletion, lipid peroxidation, and membrane deacylation). Acidosis blocked hypoxic LDH release (pH 7.4, 50 +/- 2%; pH 6.8, 6 +/- 1%) without mitigating membrane deacylation or ATP depletion. During reoxygenation, minimal LDH was released (3-5%) if pH was held constant. However, if posthypoxic pH was corrected, immediate (< or = 5 minutes) and marked cell death (e.g., 55 +/- 3% with Tris) occurred. This was dissociated from lipid peroxidation or new deacylation, and it was preceded by a depressed ATP/ADP ratio (suggesting an acidosis-associated defect in hypoxic/posthypoxic cell energetics). Realkalinization injury was not inevitable, since it could be substantially blocked by 1) posthypoxic glycine addition, 2) transient posthypoxic hypothermia, or 3) allowing a 10-minute reoxygenation (cell recovery) period before base addition. Neither mannitol nor graded buffer Ca2+ deletion conferred protection. Acute pH correction caused no injury to continuously oxygenated PTSs. Conclusions are as follows: 1) Posthypoxic "pH shock" causes virtually immediate cell death, not by causing de novo injury but, rather, by removing the cytoprotective effect of acidosis. 2) This injury can be prevented by a

  16. Proximal esophageal pH monitoring: improved definition of normal values and determination of a composite pH score.

    PubMed

    Ayazi, Shahin; Hagen, Jeffrey A; Zehetner, Joerg; Oezcelik, Arzu; Abate, Emmanuele; Kohn, Geoffrey P; Sohn, Helen J; Lipham, John C; Demeester, Steven R; Demeester, Tom R

    2010-03-01

    Patients with respiratory and laryngeal symptoms are commonly referred for evaluation of reflux disease as a potential cause. Dual-probe pH monitoring is often performed, although data on normal acid exposure in the proximal esophagus are limited because of the small number of normal subjects and inconsistent placement of the proximal pH sensor in relation to the upper esophageal sphincter. We measured proximal esophageal acid exposure using dual-probe pH and calculated a composite pH score in a large number of asymptomatic volunteers to better define normal values. Eighty-one normal subjects free of reflux, laryngeal, or respiratory symptoms were recruited. All had video esophagraphy to exclude hiatal hernia. Esophageal pH monitoring was performed using 1 of 3 different dual-probe catheters with sensors spaced 10, 15, or 18 cm apart. The standard components of esophageal acid exposure were measured, excluding meal periods. A composite pH score for the proximal esophagus was calculated using these components. The final study population consisted of 59 (49% male) subjects, with a median age of 27 years. All had normal distal esophageal acid exposure and no hiatal hernia. The 95(th) percentile values for the percent time the pH was < 4 for the total, upright, and supine periods were 0.9%, 1.2%, and 0.4%, respectively. The 95(th) percentile for the number of reflux episodes was 24 and for the calculated proximal esophageal composite pH score was 16.4. In a large population of normal subjects, we have defined the normal values and calculated a composite pH score for proximal esophageal acid exposure. The total percent time pH < 4 was similar to previously published normal values, but the number of reflux episodes was greater. Copyright 2010 American College of Surgeons. Published by Elsevier Inc. All rights reserved.

  17. Improved granular activated carbon for the stabilization of wastewater PH

    SciTech Connect

    Farmer, R.W.; Dussert, B.W.; Kovacic, S.L.

    1996-12-31

    Laboratory studies have identified the cause of the pH rise, which occurs during water treatment with activated carbon, as an interaction between the naturally occurring anions and protons in the water and the carbon surface. The interaction can be described as an ion exchange type of phenomenon, in which the carbon surface sorbs the anions and corresponding hydronium ions from the water. These studies have shown that the anion sorption and resulting pH increase is independent of the raw material used for the activated carbon production, e.g. bituminous or subbituminous coal, peat, wood or coconut. Also, the pH excursions occur with virgin, reactivated, and acid washed granular carbons. Current pH control technologies focus on adjustment of the wastewater pH prior to discharge or recycle of the initial effluent water until the pH increase abates. However, improved water pH control options have been realized by altering the carbon surface through controlled oxidation rather than the water chemistry or extended preprocessing at the treatment site.

  18. Oral pH in gastroesophageal reflux disease.

    PubMed

    Sujatha, S; Jalihal, Umesh; Devi, Yashoda; Rakesh, N; Chauhan, Pallavi; Sharma, Shivani

    2016-05-01

    The aim of this study is to compare surface pH in various parts of the oral cavity between patients with gastroesophageal reflux disease (GERD) and healthy controls. Using a flat pH meter sensor, fixed electrode pen type digital pH meter, oral pH levels were assessed at different mucosal sites among 34 GERD patients and 32 healthy controls. Salivary flow rates and buffering capacity were also assessed in them. A thorough oral examination was performed to screen for any oral and dental changes. A significantly lower pH of 6.65 ± 0.13 (mean ± SD) was found in the GERD group compared to control group 7.23 ± 0.12 (p < 0.05). Least pH was found in the floor of the mouth 6.594 ± 0.17 and highest in the lower labial mucosa among the GERD patients. Salivary flow rate and buffering capacity were low in these patients. Significant changes were noticed in the hard and soft tissues of the oral cavity among the GERD group. Oral mucosal pH is altered in GERD patients and may contribute to effects on the oral cavity.

  19. A ph sensor based on a flexible substrate

    NASA Astrophysics Data System (ADS)

    Huang, Wen-Ding

    pH sensor is an essential component used in many chemical, food, and bio-material industries. Conventional glass electrodes have been used to construct pH sensors, however, have some disadvantages. Glass electrodes are easily affected by alkaline or HF solution, they require a high input impedance pH meter, they often exhibit a sluggish response. In some specific applications, it is also difficult to use glass electrodes for in vivo biomedical or food monitoring applications due to the difficulty of size miniaturization, planarization and polymerization based on current manufacturing technologies. In this work, we have demonstrated a novel flexible pH sensor based on low-cost sol-gel fabrication process of iridium oxide (IrOx) sensing film (IROF). A pair of flexible miniature IrOx/AgCl electrode generated the action potential from the solution by electrochemical mechanism to obtain the pH level of the reagent. The fabrication process including sol-gel, thermal oxidation, and the electro-plating process of the silver chloride (AgCl) reference electrode were reported in the work. The IrOx film was verified and characterized using electron dispersive analysis (EDAX), scanning electron microscope (SEM), and x-ray diffraction (XRD). The flexible pH sensor's performance and characterization have been investigated with different testing parameters such as sensitivity, response time, stability, reversibility, repeatability, selectivity and temperature dependence. The flexible IrOx pH sensors exhibited promising sensing performance with a near-Nernstian response of sensitivity which is between --51.1mV/pH and --51.7mV/pH in different pH levels ranging from 1.5 to 12 at 25°C. Two applications including gastroesophageal reflux disease (GERD) diagnosis and food freshness wireless monitoring using our micro-flexible IrOx pH sensors were demonstrated. For the GERD diagnosing system, we embedded the micro flexible pH sensor on a 1.2cmx3.8cm of the capsule size of wireless sensor

  20. Optical fibre PH sensor based on immobilized indicator

    NASA Astrophysics Data System (ADS)

    Cai, Defu; Cao, Qiang; Han, JingHong; Cai, Jine; Li, YaTing; Zhu, ZeMin; Fan, Jie; Gao, Ning

    1991-08-01

    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.

  1. Innovation in Learning: PhD and DNP Student Collaborations.

    PubMed

    Eaton, Linda H; Gordon, Debra B; Doorenbos, Ardith Z

    2017-09-01

    Working together, PhD and Doctor of Nursing Practice (DNP) students can advance knowledge creation and the translation of knowledge into practice. Although different in purpose and education, PhD and DNP programs should prepare students to collaborate throughout their careers. This article describes an innovative pilot project that partnered PhD and DNP students during their graduate programs. Group meetings were used to facilitate collaboration among 12 PhD and DNP students interested in pain management. Using a five-stage collaboration process model, students worked together on dissertation and capstone projects. PhD and DNP students collaborated on the completion of dissertation and capstone projects, as well as on publications and presentations. A case example of an effective partnership is included. Partnering of PhD and DNP students can further the development of new nursing knowledge and evidence-based practice. Successful collaboration can be facilitated by PhD and DNP faculty. [J Nurs Educ. 2017;56(9):556-559.]. Copyright 2017, SLACK Incorporated.

  2. Nanochannel pH gradient electrofocusing of proteins.

    PubMed

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

    2013-08-06

    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.

  3. Critical assessment of the pH of children's soap.

    PubMed

    Mendes, Bruna Rafaela; Shimabukuro, Danielle Midori; Uber, Marjorie; Abagge, Kerstin Taniguchi

    2016-01-01

    To evaluate the pH value of children's antibacterial soaps and syndets used in children's baths and verify whether there is information regarding pH on the product label. Quantitative, cross-sectional, analytical observational study that included ninety soap samples, both in bar and liquid presentations, as follows: 67 children's soap (group 1), 17 antibacterial soaps (group 2), and 6 syndets (group 3). Each sample had its pH measured after 1% dilution. In addition to descriptive statistics, the Pearson-Yates chi-squared test and Student's t-tests were applied, considering the minimal significance level of 5%. The Wilcoxon-Mann-Whitney test, Fisher's exact test, and the Kruskal-Wallis test were used for inferential statistics. The pH levels varied considerably between liquid and bar presentations, with lower levels (4.4-7.9) found for the liquids (p<0.05). Syndets showed pH levels close to the ideal (slightly acid) and the antibacterial soaps showed the highest pH levels (up to 11.34) (p<0.05). Only two of the soaps included in the study had information about their pH levels on the product packaging. Knowledge of the pH of children's soap by doctors and users is important, considering the great pH variability found in this study. Moreover, liquid soaps, and especially syndets, are the most recommended for the sensitive skin of neonates and infants, in order to guarantee skin barrier efficacy. Copyright © 2016 Sociedade Brasileira de Pediatria. Published by Elsevier Editora Ltda. All rights reserved.

  4. Umbilical Cord Blood pH in Intrapartum Hypoxia.

    PubMed

    Perveen, Fouzia; Khan, Ayesha; Ali, Tahmina; Rabia, Syeda

    2015-09-01

    To determine the association of cord arterial blood pH with neonatal outcome in cases of intrapartum fetal hypoxia. Descriptive analytical study. Gynaecology Unit-II, Civil Hospital, Karachi, from September 2011 to November 2012. All singleton cephalic fetuses at term gestation were included in the study. Those with any anomaly, malpresentation, medical disorders, maternal age < 18 years, multiple gestation and ruptured membranes were excluded. Patients with abnormal cardiotocography and/or meconium stained liquor were enrolled as index case and immediate next delivery with no such signs as a control. Demographic characteristics, pH level < or > 7.25, neonatal outcome measures (healthy, NICU admission or neonatal death), color of liquor and mode of delivery recorded on predesigned proforma. Statistical analysis performed by SPSS 16 by using independent-t test or chi-square test and ANOVA test as needed. A total of 204 newborns were evaluated. The mean pH level was found to be significantly different (p=0.007) in two groups. The pH value 7.25 had significant association (p < 0.001) with the neonatal outcome. However, the association of neonatal outcome with severity of acidemia was not found to be significant. Grading of Meconium Stained Liquor (MSL) also did not relate positively with pH levels as 85.7% of grade I, 68.9% of grade II and 59.4% of grade III MSLhad pH > 7.25. Majority (63.6%) cases needed caesarean section as compared to 31.4% controls. There is a significant association of cord arterial blood pH at birth with neonatal outcome at pH < or > 7.25; but below the level of pH 7.25 it is still inconclusive.

  5. pH Responsiveness of hydrogels formed by telechelic polyampholytes.

    PubMed

    Dyakonova, Margarita A; Gotzamanis, George; Niebuur, Bart-Jan; Vishnevetskaya, Natalya S; Raftopoulos, Konstantinos N; Di, Zhenyu; Filippov, Sergey K; Tsitsilianis, Constantinos; Papadakis, Christine M

    2017-05-21

    We investigate the influence of pH on the rheological and structural properties of hydrogels formed by hydrophobic association of the sticky ends of the triblock terpolymer poly(methyl methacrylate)-b-poly(2-(diethylamino)ethyl methacrylate-co-methacrylic acid)-b-poly(methyl methacrylate) (PMMA-b-P(DEA-co-MAA)-b-PMMA). The middle block is a weak polyampholyte having a pH dependent charge density and sign, which enables tuning of the rheological and structural properties by pH variation. Small-angle neutron scattering (SANS) studies of solutions in D2O at 0.05 wt% and pH 3.0 reveal clusters of interconnected spherical micelles having PMMA cores, stabilized by repulsive ionic interactions in the middle polyampholyte block. With increasing pH, the degree of ionization of the DEA units decreases, whereas the one of the MAA units increases, resulting in a complete loss of the correlation between these micelles. At a concentration of 3 wt% at low pH values, the system forms a gel with charged fuzzy spheres from PMMA interacting via a screened Coulomb potential. With increasing pH, the gel disintegrates due to the decrease in the effective charge on the micelles. At both concentrations, the hydrophobic aggregation of micelles is observed near the isoelectric point. At pH 3.0-7.4, the autocorrelation functions measured by rotational dynamic light scattering at 3 wt% exhibit a decay steeper than single exponential, which confirms that the gels are frozen, presumably due to the glassy PMMA cores and hydrophobic interpolyelectrolyte complexes. At pH 11, the diffusion of single micelles is observed in addition to the frozen dynamics.

  6. Axillary pH and influence of deodorants.

    PubMed

    Stenzaly-Achtert, S.; Schölermann, A.; Schreiber, J.; Diec, K. H.; Rippke, F.; Bielfeldt, S.

    2000-05-01

    BACKGROUND/AIMS: In moist intertriginous regions, such as the armpit, the pH value is physiologically higher than in other skin regions. The regulation of the axillary pH-value was examined in an open study with 48 subjects in three groups with n=16 each. METHODS: In the first 10 days (run-in) the subjects received a standard treatment in the axilla with shaving, cleansing and application of a pH-neutral deodorant. This was followed by a 5 day treatment period with the three test products (pH5 Eucerin(R) Deodorant Roll-on, Deodorant Balsam Spray, Deodorant Cream). The study was concluded by a wash-out period with procedures identical to the run-in phase. The pH was measured with a calibrated pH-meter. RESULTS: A significant pH reduction was shown during the treatment period when compared to the run-in phase. The Deodorant Roll-on induced a reduction of the mean pH values from 6.1 to 5.3, the Deodorant Balsam Spray from 6.5 to 5.7 and the Deodorant Cream from 6.2 to 5.3. During the wash-out period all pH values returned to baseline. CONCLUSION: All of the deodorants tested demonstrated a significant reduction in axillary pH. There is evidence that a high skin pH promotes the growth of several microorganisms that produce malodor. Therefore, the regulation of pH may contribute to the deodorant efficacy of the test products.

  7. Method for producing rapid pH changes

    DOEpatents

    Clark, John H.; Campillo, Anthony J.; Shapiro, Stanley L.; Winn, Kenneth R.

    1981-01-01

    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.

  8. Method for producing rapid pH changes

    DOEpatents

    Clark, J.H.; Campillo, A.J.; Shapiro, S.L.; Winn, K.R.

    A method of initiating a rapid pH change in a solution comprises 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.

  9. Imaging pH with hyperpolarized 13C.

    PubMed

    Gallagher, Ferdia A; Kettunen, Mikko I; Brindle, Kevin M

    2011-10-01

    pH is a fundamental physiological parameter that is tightly controlled by endogenous buffers. The acid-base balance is altered in many disease states, such as inflammation, ischemia and cancer. Despite the importance of pH, there are currently no routine methods for imaging the spatial distribution of pH in humans. The enormous gain in sensitivity afforded by dynamic nuclear polarization (DNP) has provided a novel way in which to image tissue pH using MR, which has the potential to be translated into the clinic. This review explores the advantages and disadvantages of current pH imaging techniques and how they compare with DNP-based approaches for the measurement and imaging of pH with hyperpolarized (13)C. Intravenous injection of hyperpolarized (13)C-labeled bicarbonate results in the rapid production of hyperpolarized (13)CO(2) in the reaction catalyzed by carbonic anhydrase. As this reaction is close to equilibrium in the body and is pH dependent, the ratio of the (13)C signal intensities from H(13)CO(3)(-) and (13)CO(2), measured using MRS, can be used to calculate pH in vivo. The application of this technique to a murine tumor model demonstrated that it measured predominantly extracellular pH and could be mapped in the animal using spectroscopic imaging techniques. A second approach has been to use the production of hyperpolarized (13)CO(2) from hyperpolarized [1-(13)C]pyruvate to measure predominantly intracellular pH. In tissues with a high aerobic capacity, such as the heart, the hyperpolarized [1-(13)C]pyruvate undergoes rapid oxidative decarboxylation, catalyzed by intramitochondrial pyruvate dehydrogenase. Provided that there is sufficient carbonic anhydrase present to catalyze the rapid equilibration of the hyperpolarized (13)C label between CO(2) and bicarbonate, the ratio of their resonance intensities may again be used to estimate pH, which, in this case, is predominantly intracellular. As both pyruvate and bicarbonate are endogenous molecules they

  10. Effect of pH on Human Mycoplasma Strains

    PubMed Central

    Shepard, Maurice C.; Lunceford, Carl D.

    1965-01-01

    Shepard, Maurice C. (U.S. Naval Medical Field Research Laboratory, Camp Lejeune, N.C.), and Carl D. Lunceford. Effect of pH on human Mycoplasma strains. J. Bacteriol. 89:265–270. 1965.—The optimal reaction of culture media for the cultivation of T-strain Mycoplasma of human origin was investigated. By use of a recently modified tryptic digest medium, the optimal reaction in either agar or fluid medium was found to be pH 6.0. In contrast, human classic (large-colony) Mycoplasma could be cultivated in agar or fluid medium over a rather broad pH range, and the influence of the reaction of the medium appeared to be primarily species-dependent. M. salivarium, for example, grew best in agar from pH 5.5 through 6.5. M. pneumoniae (Easton's agent) yielded largest colony numbers in agar and highest titers in broth at pH 8.0. In the case of T-strain Mycoplasma, both maximal colony numbers in agar and highest titers in fluid media were achieved at a reaction of pH 6.0. In addition, largest colony size of T-strain Mycoplasma was also achieved in agar at pH 6.0, and averaged 50 to 100% larger than that obtained by cultivation at pH 8.0 with the same medium. Although T-strains will develop in agar media over a pH range of from 5.0 through 10.0, the extremely small colony size and poor staining properties resulting from growth in an alkaline medium make their recognition in agar cultures difficult. Aerobic cultivation of T-strains was first achieved in agar adjusted to pH 5.5 to 6.0. In fluid medium, multiplication of T-strains occurred only within the limits of pH 5.0 through 8.0, with highest titers being reached at pH 6.0. Greater attention to the reaction of complete Mycoplasma media is stressed. PMID:14255688

  11. Near Infrared Spectral Determination of Human Tissue pH.

    DTIC Science & Technology

    1995-10-01

    Continuous Tissue pH Monitory in the Human Fetus During Labor", Obstet . Gynecol ., 55:523, 1980. 23. [Lemer 82] Lemer, H., et al., "Measurement of Glucose...Umbilical Blood pH", Am. J. Obstet . Gynecol ., 128: 901-903, 1977. 38. [Weyer 85] Weyer, L G., "Near Infrared Spectroscopy of Organic Substances," Applied...Patterns and Tissue pH in the Human Fetus", Am. J. Obstet . Gynecol ., 134:685-690, 1979. 24 Appendix I An Estimation Extension of the FKNN Algorithm In

  12. pH sensor based on boron nitride nanotubes

    NASA Astrophysics Data System (ADS)

    Huang, Q.; Bando, Y.; Zhao, L.; Zhi, C. Y.; Golberg, D.

    2009-10-01

    A submicrometer-sized pH sensor based on biotin-fluorescein-functionalized multiwalled BN nanotubes with anchored Ag nanoparticles is designed. Intrinsic pH-dependent photoluminescence and Raman signals in attached fluorescein molecules enhanced by Ag nanoparticles allow this novel nanohybrid to perform as a practical pH sensor. It is able to work in a submicrometer-sized space. For example, the sensor may determine the environmental pH of sub-units in living cells where a traditional optical fiber sensor fails because of spatial limitations.

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

    PubMed

    Goldberg, Charles; Insel, Paul A

    2013-06-01

    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.

  14. Meet EPA Engineer Shawn Ryan, Ph.D.

    EPA Pesticide Factsheets

    Shawn Ryan, Ph.D. is a chemical engineer at EPA's National Homeland Security Research Center. He has worked at EPA for 12 years, nine of which have been devoted to leading research to support decontamination and consequence management.

  15. Meet EPA Scientist Heriberto Cabezas, Ph.D.

    EPA Pesticide Factsheets

    Heriberto Cabezas, Ph.D. is currently the Senior Science Advisor to the Sustainable Technology Division in EPA's National Risk Management Research Lab, where he works to advance the application of science and technologies to address sustainability.

  16. Meet EPA Environmental Engineer Terra Haxton, Ph.D.

    EPA Pesticide Factsheets

    EPA Environmental Engineer Terra Haxton, Ph.D., uses computer simulation models to protect drinking water. She investigates approaches to help water utilities be better prepared to respond to contamination incidents in their distribution systems.

  17. Meet EPA Scientist Tim Shafer, Ph.D.

    EPA Pesticide Factsheets

    Tim Shafer earned his bachelor’s degree in biology and chemistry from Hope College in Holland, MI, in 1986 and his Ph.D. in pharmacology and environmental toxicology from Michigan State University in 1991.

  18. Meet EPA Biologist Laura Jackson, Ph.D.

    EPA Pesticide Factsheets

    Research Biologist Laura Jackson, Ph.D., has worked for the EPA for 22 years, leading research initiatives in a diversity of disciplines, including environmental monitoring, land use planning, and the impacts that urbanization has on an area's ecology

  19. Meet EPA Scientist Susan Yee, Ph.D.

    EPA Pesticide Factsheets

    Susan Yee, Ph.D., is an ecologist at EPA's Gulf Ecology Division. She is working on the Puerto Rico Sustainable Communities program, developing decision support tools to evaluate how alternative decisions impact coastal ecosystem goods and services

  20. Meet EPA Scientist Michael Nye, Ph.D.

    EPA Pesticide Factsheets

    Michael Nye, Ph.D., is a social scientist who studies natural risk, socio-demographic change and sustainable behavior. Prior to joining EPA, he worked for the UK Environment Agency in flood risk management and emergency preparedness

  1. Commentary: PhDs in biochemistry education-5 years later.

    PubMed

    Offerdahl, Erika G; Momsen, Jennifer L; Osgood, Marcy

    2014-01-01

    In this commentary, the discussion of PhDs in biochemistry education research is expanded to explore a number of diverse pathways leading to a competitive research program in biochemistry education research.

  2. Commentary: PhDs in Biochemistry Education--5 Years Later

    ERIC Educational Resources Information Center

    Offerdahl, Erika G.; Momsen, Jennifer L.; Osgood, Marcy

    2014-01-01

    In this commentary, the discussion of PhDs in biochemistry education research is expanded to explore a number of diverse pathways leading to a competitive research program in biochemistry education research.

  3. Meet EPA Microbiologist Eric Villegas, Ph.D.

    EPA Pesticide Factsheets

    Eric Villegas, Ph.D. is a research microbiologist in EPA's Office of Research and Development. His recent work focuses on next generation sequencing technology to better understand risks associated with waterborne parasites.

  4. Ashley Felix, Ph.D., M.P.H.

    Cancer.gov

    NCI Cancer Prevention Fellowship Program (CPFP) alumna, Ashley Felix, Ph.D., M.P.H., details her transition from pre-med student to an epidemiologist who focuses on studying the causes and prevention of disease.

  5. Meet EPA Scientist Dermont Bouchard, Ph.D.

    EPA Pesticide Factsheets

    EPA Scientist Dermont Bouchard, Ph.D., is working to better understand how tiny nanomaterials might be released into the environment. His research helps regulators and other decision-makers lower risks and better protect human health and the environment

  6. Colorimetric pH measurement of animal cell culture media.

    PubMed

    Jang, Juno; Moon, Soo-Jin; Hong, Sung-Hwan; Kim, Ik-Hwan

    2010-11-01

    Most animal cell culture media can be buffered using bicarbonate and high pressure CO(2) in a closed system. However, in an open system, the pH of the culture media increases continuously due to the marked difference in CO(2) pressure between the culture media and the atmosphere. Therefore, it is important to measure the exact pH of the culture media in an intact closed system. In this study, a pH measurement method was developed using visible light. The pH was calculated from light absorbance by the cells and by the culture media. This method was successfully applied to both suspension and anchorage-dependent cell cultures.

  7. Meet EPA Scientist Valerie Zartarian, Ph.D.

    EPA Pesticide Factsheets

    Senior exposure scientist and research environmental engineer Valerie Zartarian, Ph.D. helps build computer models and other tools that advance our understanding of how people interact with chemicals.

  8. Brenda K. Edwards, PhD | DCCPS/NCI/NIH

    Cancer.gov

    Brenda K. Edwards, PhD, has been with the Surveillance Research Program (SRP) and its predecessor organizations at the National Cancer Institute (NCI) since 1989, serving as SRP’s Associate Director from 1990-2011.

  9. pH Effects on Electrospray Ionization Efficiency

    NASA Astrophysics Data System (ADS)

    Liigand, Jaanus; Laaniste, Asko; Kruve, Anneli

    2017-03-01

    Electrospray ionization efficiency is known to be affected by mobile phase composition. In this paper, a detailed study of analyte ionization efficiency dependence on mobile phase pH is presented. The pH effect was studied on 28 compounds with different chemical properties. Neither p K a nor solution phase ionization degree by itself was observed to be sufficient at describing how aqueous phase pH affects the ionization efficiency of the analyte. Therefore, the analyte behavior was related to various physicochemical properties via linear discriminant analyses. Distinction between pH-dependent and pH-independent compounds was achieved using two parameters: number of potential charge centers and hydrogen bonding acceptor capacity (in the case of 80% acetonitrile) or polarity of neutral form of analyte and p K a (in the case of 20% acetonitrile). It was also observed that decreasing pH may increase ionization efficiency of a compound by more than two orders of magnitude.

  10. Meet EPA Chemist Linda Sheldon, Ph.D.

    EPA Pesticide Factsheets

    Environmental chemist Linda Sheldon, Ph.D, is the Associate Director for Human Heath in the National Exposure Research Laboratory. She studies environmental exposure, particularly focusing on children's environments and their contact with chemicals.

  11. Meet EPA Natural Resource Economist Marisa Mazzotta, Ph.D.

    EPA Pesticide Factsheets

    Marisa Mazzotta, Ph.D. currently works as an Economist at EPA's Atlantic Ecology Division. Her research focuses on the public's valuation and prioritization of natural resources, and the relationship between ecological changes and economic benefits.

  12. Meet EPA Scientist Jody Shoemaker, Ph.D.

    EPA Pesticide Factsheets

    EPA research chemist Jody Shoemaker, Ph.D., works to support Agency efforts to protect drinking water. She helps develop methods for analyzing organic chemicals on the Drinking Water Contaminant Candidate List (CCL).

  13. Meet EPA Scientist Blake Schaeffer, Ph.D.

    EPA Pesticide Factsheets

    EPA research ecologist Blake Schaeffer, Ph.D. focuses on ways to use satellite remote sensing technology to monitor water quality. His research interests broadly include deriving water quality parameters in coasts, estuaries, and lakes using satellites

  14. The Training and Work of Ph.D. Physical Scientists

    NASA Astrophysics Data System (ADS)

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

    2003-05-01

    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.

  15. Meet EPA Chemist Quincy Teng, Ph.D.

    EPA Pesticide Factsheets

    EPA research chemist Quincy Teng, Ph.D., focuses on the application of metabolomics—a relatively new, specialized field of biochemistry focused on studying small molecules known as metabolites—on environmental and life sciences.

  16. Commentary: PhDs in Biochemistry Education--5 Years Later

    ERIC Educational Resources Information Center

    Offerdahl, Erika G.; Momsen, Jennifer L.; Osgood, Marcy

    2014-01-01

    In this commentary, the discussion of PhDs in biochemistry education research is expanded to explore a number of diverse pathways leading to a competitive research program in biochemistry education research.

  17. Meet EPA Biologist Mitch Kostich, Ph.D.

    EPA Pesticide Factsheets

    EPA biologist, Mitch Kostich, Ph.D., conducts research to identify risks from exposures to chemical contaminants in water. His research uses technologies to prioritize contaminants in the environment based on the potential risks they pose to life

  18. The geologic history of seawater pH

    NASA Astrophysics Data System (ADS)

    Halevy, I.; Bachan, A.

    2017-03-01

    Although pH is a fundamental property of Earth’s oceans, critical to our understanding of seawater biogeochemistry, its long-timescale geologic history is poorly constrained. We constrain seawater pH through time by accounting for the cycles of the major components of seawater. We infer an increase from early Archean pH values between ~6.5 and 7.0 and Phanerozoic values between ~7.5 and 9.0, which was caused by a gradual decrease in atmospheric pCO2 in response to solar brightening, alongside a decrease in hydrothermal exchange between seawater and the ocean crust. A lower pH in Earth’s early oceans likely affected the kinetics of chemical reactions associated with the origin of life, the energetics of early metabolisms, and climate through the partitioning of CO2 between the oceans and atmosphere.

  19. Thermodynamic, Kinetic, Structural, and Computational Studies of the Ph3Sn-H, Ph3Sn-SnPh3, and Ph3Sn-Cr(CO)3C5Me5 Bond Dissociation Enthalpies.

    PubMed

    Cai, Xiaochen; Majumdar, Subhojit; Fortman, George C; Koppaka, Anjaneyulu; Serafim, Leonardo; Captain, Burjor; Temprado, Manuel; Hoff, Carl D

    2016-10-05

    The kinetics of the reaction of Ph3SnH with excess •Cr(CO)3C5Me5 = •Cr, producing HCr and Ph3Sn-Cr, was studied in toluene solution under 2-3 atm CO pressure in the temperature range of 17-43.5 °C. It was found to obey the rate equation d[Ph3Sn-Cr]/dt = k[Ph3SnH][•Cr] and exhibit a normal kinetic isotope effect (kH/kD = 1.12 ± 0.04). Variable-temperature studies yielded ΔH(‡) = 15.7 ± 1.5 kcal/mol and ΔS(‡) = -11 ± 5 cal/(mol·K) for the reaction. These data are interpreted in terms of a two-step mechanism involving a thermodynamically uphill hydrogen atom transfer (HAT) producing Ph3Sn• and HCr, followed by rapid trapping of Ph3Sn• by excess •Cr to produce Ph3Sn-Cr. Assuming an overbarrier of 2 ± 1 kcal/mol in the HAT step leads to a derived value of 76.0 ± 3.0 kcal/mol for the Ph3Sn-H bond dissociation enthalpy (BDE) in toluene solution. The reaction enthalpy of Ph3SnH with excess •Cr was measured by reaction calorimetry in toluene solution, and a value of the Sn-Cr BDE in Ph3Sn-Cr of 50.4 ± 3.5 kcal/mol was derived. Qualitative studies of the reactions of other R3SnH compounds with •Cr are described for R = (n)Bu, (t)Bu, and Cy. The dehydrogenation reaction of 2Ph3SnH → H2 + Ph3SnSnPh3 was found to be rapid and quantitative in the presence of catalytic amounts of the complex Pd(IPr)(P(p-tolyl)3). The thermochemistry of this process was also studied in toluene solution using varying amounts of the Pd(0) catalyst. The value of ΔH = -15.8 ± 2.2 kcal/mol yields a value of the Sn-Sn BDE in Ph3SnSnPh3 of 63.8 ± 3.7 kcal/mol. Computational studies of the Sn-H, Sn-Sn, and Sn-Cr BDEs are in good agreement with experimental data and provide additional insight into factors controlling reactivity in these systems. The structures of Ph3Sn-Cr and Cy3Sn-Cr were determined by X-ray crystallography and are reported. Mechanistic aspects of oxidative addition reactions in this system are discussed.

  20. Allosteric properties of PH domains in Arf regulatory proteins.

    PubMed

    Roy, Neeladri Sekhar; Yohe, Marielle E; Randazzo, Paul A; Gruschus, James M

    2016-01-01

    Pleckstrin Homology (PH) domains bind phospholipids and proteins. They are critical regulatory elements of a number enzymes including guanine nucleotide exchange factors (GEFs) and GTPase-activating proteins (GAPs) for Ras-superfamily guanine nucleotide binding proteins such as ADP-ribosylation factors (Arfs). Recent studies have indicated that many PH domains may bind more than one ligand cooperatively. Here we discuss the molecular basis of PH domain-dependent allosteric behavior of 2 ADP-ribosylation factor exchange factors, Grp1 and Brag2, cooperative binding of ligands to the PH domains of Grp1 and the Arf GTPase-activating protein, ASAP1, and the consequences for activity of the associated catalytic domains.

  1. Stress-Corrosion Cracking in Martensitic PH Stainless Steels

    NASA Technical Reports Server (NTRS)

    Humphries, T.; Nelson, E.

    1984-01-01

    Precipitation-hardening alloys evaluated in marine environment tests. Report describes marine-environment stress-corrosion cracking (SCC) tests of three martensitic precipitation hardening (PH) stainless-steel alloys.

  2. Meet EPA Scientist Jeff Szabo, Ph.D.

    EPA Pesticide Factsheets

    EPA scientist Jeff Szabo, Ph.D., has worked for the EPA’s National Homeland Security Research Center since 2005. He conducts and manages water security research projects at EPA’s Test and Evaluation facility.

  3. Meet EPA Ecologist Paul Mayer, Ph.D.

    EPA Pesticide Factsheets

    EPA ecologist Paul Mayer, Ph.D. works in EPA's Groundwater and Ecosystem Restoration division where he studies riparian zones (the area along rivers and streams where the habitats are influenced by both the land and water) and stream restoration

  4. Meet EPA Scientist Jordan West, Ph.D.

    EPA Pesticide Factsheets

    Jordan West, Ph.D. is an aquatic ecologist at EPA. Her areas of expertise include freshwater & marine ecology, climate change impacts and adaptation, resilience and threshold theory, environmental risk assessment, expert elicitation & stakeholder processes

  5. Swiss national MD-PhD-program: an outcome analysis.

    PubMed

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

    2009-09-19

    This study aims at a first evaluation of the outcome of the Swiss national MD-PhD program during the last 16 years. 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. Twenty-four questions assessed information regarding participant demographics, information on the PhD thesis and publication activity, current positions and research activity, as well as participant's opinions, attitudes and career goals. Eighty questionnaires were received from 126 MD-PhD students and graduates (63.5% response rate). The responders consisted of present students (36%), former graduates (56%), and dropouts (8%). The percentage of women in the program was 23%, and the average duration of the program was 4.2 +/- 1.4 years. Research interests were predominantly in the fields of neuroscience, immunology, molecular biology and cancer research. A considerable portion of the MD-PhD graduates had an excellent publication record stemming from their PhD research work, and 89% were planning to continue a research-orientated career. Over 50% of those MD-PhD graduates completing their thesis before 2002 had already reached an assistant or full professor position at the time of the survey. Nearly all participants considered the MD-PhD training helpful to their career and high quality standards were assigned to the acquired practical and intellectual skills. However, criticism was expressed concerning the general mentoring and the career related mentoring. Moreover, general mentoring and career related mentoring were significantly less well perceived in research groups employing more than seven PhD students at the same time. The MD-PhD students and graduates surveyed were satisfied with their education and most of them continued a research-orientated career. Regarding the overall positive evaluation, this study supports the view that MD-PhD graduates are well qualified for a successful career in

  6. [Photohemolysis sensitized by psoralen: dependence on pH].

    PubMed

    Potapenko, A Ia; Belichenko, I V; Mamedov, I S; Zhuravel', N N; Kiagova, A A; Beijersbergen van Henegouwen, G M J; De Vries, Ch

    2007-01-01

    The effect of pH on the hemolysis of erythrocytes photosensitized (366 nm, 23 Wt/m2) by psoralen has been studied. The dependence of the photohemolysis rate (V) on irradiation dose (D) was described by the equation V = Vo + kD, where Vo is the rate of hemolysis without irradiation (dark), and k is the constant. The index of the power at dose x was approximately equal to 2, and its value did not change as the pH of the erythrocyte suspension was changed. It was found that changes in pH led to a sharp change in the value of coefficient k and correspondingly V. The lowest rate of photohemolysis was observed in the pH range from 8.0 to 8.4. As pH was changed from 3.4 to 9.0 or from 8.0 to 7.4, the V value increased approximately twofold. At pH below 7.4, an abrupt increase (approximately fourfold) in V was observed, with the pK value being equal to 7.3. The psoralen molecule lacks titratable acidic and basic groups; therefore, the effects of pH can hardly be assigned to changes in the photophysical properties of the sensitizer. The increase in V in the alkaline region is prohably related to the acceleration of photooxidation of reduced glutathione, whereas the jump of V at pH of about 7.3 may be due to the titration of the product of psoralen photooxidation. The latter assumption is confirmed by the data of hign performance liquid chromatography. In these experiments, psoralen was oxidized in ethanol and mixed with the phosphate buffer at different pH values followed by a qualitative and quantitative analysis by high performance liquid chromatography of photoproducts. Several photoproducts of psoralen have been identified whose content depended on pH. The curve of titration of one photoproduct was similar in shape to the pH dependence of psoralen-photosensitized hemolysis.

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

    PubMed Central

    Liao, Yi-Hung; Chou, Jung-Chuan

    2012-01-01

    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.

  8. Teaching Human Digestion and pH Using Technology

    ERIC Educational Resources Information Center

    Kim, Hanna

    2008-01-01

    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…

  9. Jennifer Sargent, PhD | Center for Cancer Research

    Cancer.gov

    Jennifer Sargent, PhDMay 3, 2016 Senior Editor, The Lancet London, UK Jennifer Sargent, Ph.D., is currently a Senior Editor at The Lancet.  Previously, she was an Associate Editor at Nature Reviews Endocrinology.  Dr. Sargent is also a former NIH Research Fellow, and served as an editor on the NIH Fellows Editorial Board, as well as completing a NIH Catalyst editorial internship. Topics to be covered:

  10. Teaching Human Digestion and pH Using Technology

    ERIC Educational Resources Information Center

    Kim, Hanna

    2008-01-01

    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…

  11. Shumard Oaks Successfully Planted on High pH Soils

    Treesearch

    Harvey E. Kennedy; Roger M. Krinard

    1985-01-01

    Shumard oak was successfully planted on high pH (7.8-8.0) Mississippi River alluvium soils where some other planted red oaks had failed. Survival and growth have been good through ages 10, 11, and 25 years in three separate plantings. Shumard oak on high pH soils, in addition to producing timber, would allow a consistent mast-producing tree on sites normally void of...

  12. Mouthguard and sports drinks on tooth surface pH.

    PubMed

    Maeda, Y; Yang, T-C; Miyanaga, H; Tanaka, Y; Ikebe, K; Akimoto, N

    2014-09-01

    The influence of sports drinks and mouthguards on the pH level of tooth surface was examined. A custom-made mouthguard was fabricated for each subject. The pH level was measured by electric pH meter with sensitivity of 0.01 up to 30 min. Sports drinks (pH=3.75) containing 9.4% sugar were used in this study. Measurements were performed on a cohort of 23 female subjects without a mouthguard (control), wearing a mouthguard only (MG), wearing a mouthguard after 30 ml sports drink intake (SD+MG), wearing a mouthguard during a 5-min jogging exercise (MG+EX) and wearing a mouthguard during jogging after sports drink intake (SD+MG+EX). For 7 male subjects, the same measurements were performed while a sports drink was taken over the mouthguard (MG+SD, MD+EX+SD). MG showed statistically higher pH level than control (p<0.05). SD+MG exhibited a significant decrease in pH level, and SD+MG+EX exhibited even below the critical level of pH 5.5 in some subjects. When sports drinks were taken over the mouthguard, no significant differences in pH level were observed among the different conditions.Within the limitations of this study, it was suggested that wearing a mouthguard during exercise is in itself not a possible risk factor for dental caries, while wearing a mouthguard after consuming sports drinks is.

  13. The PhD in Writing Accompanied by an Exegesis

    ERIC Educational Resources Information Center

    Arnold, Josie

    2005-01-01

    The position of this paper is to further the discussion on what constitutes academic assessment in the PhD by artefact and exegesis. In doing so, it explores some of the ideas that arose in setting up the PhD in creative writing at Swinburne University of Technology. Thus, I: (1) survey some of the questions that arise about the journeys made by…

  14. MD-PhD training: looking back and looking forward.

    PubMed

    Bonham, Ann C

    2014-01-01

    MD-PhD programs provide rigorous, integrated training for physician-scientists, enabling them to frame scientific questions in unique ways and to apply clinical insight to fundamental science. Few would question the influential contributions of MD-PhD physician-scientists in advancing medical science. In this issue of Academic Medicine, Jeffe et al affirm high levels of excellence in educational outcomes from MD-PhD training programs at U.S. MD-granting medical schools, especially programs that receive funding from the NIH Medical Scientist Training Program (MSTP). The author of this commentary observes that, in the face of current economic pressures, comprehensive, longitudinal national outcomes data from MSTP- and non-MSTP-funded MD-PhD programs will help verify the value provided by MD-PhD physician-scientists. She proposes that MD-PhD programs should better prepare the next generation of physician-scientists for future research environments, which will provide new technologies, venues, and modalities. These research environments will be more closely integrated within health care delivery systems, extend into diverse communities and regions, and employ complex technologies. MD-PhD physician-scientists also will train and gain expertise in broadening areas of research, such as health policy, health economics, clinical epidemiology, and medical informatics. Program leaders are ideally situated to foster innovative learning environments and methodologies. By sharing their innovations, they can help ensure production of a diverse MD-PhD physician-scientist workforce, prepared to engage in myriad research opportunities to meet patient and population needs in a new environment.

  15. PH-Sensitive Ni(OH)2-Based Microelectrochemical Transistors.

    DTIC Science & Technology

    1986-11-24

    basic solution is increased, VG for device turn on moves negative, in accord with the known pH dependence of the redox chemistry of Ni(OH)2 " Detection...transistor behavicr i 3 illustrated under dynamic and steady state conditions; as the pH of a basic solution is increased, VG for device turn on moves...important battery electrode, Ni(OH)2 is an electrochromic material, becoming colored upon electrochemical oxidation.6 Like other electrochromic transition

  16. Glutamate transport into synaptic vesicles. Roles of membrane potential, pH gradient, and intravesicular pH.

    PubMed

    Tabb, J S; Kish, P E; Van Dyke, R; Ueda, T

    1992-08-05

    Glutamate, the major excitatory neurotransmitter in the mammalian central nervous system, is transported into bovine synaptic vesicles in a manner that is ATP dependent and requires a vesicular electrochemical proton gradient. We studied the electrical and chemical elements of this driving force and evaluated the effects of chloride on transport. Increasing concentrations of Cl- were found to increase the steady-state ATP-dependent vesicular pH gradient (delta pH) and were found to concomitantly decrease the vesicular membrane potential (delta psi). Low millimolar chloride concentrations, which cause 3-6-fold stimulation of vesicular glutamate uptake, caused small but measurable increases in delta pH and decreases in delta psi, when compared to control vesicles in the absence of chloride. Nigericin in potassium buffers was used to alter the relative proportions of delta pH and delta psi. Compared to controls, at all chloride concentrations tested, nigericin virtually abolished delta pH and increased the vesicle interior positive delta psi. Concomitantly, nigericin increased ATP-dependent glutamate uptake in 0-1 mM chloride but decreased glutamate uptake in 4 mM (45%), 20 mM (80%), and 140 mM (75%) Cl- (where delta pH in the absence of nigericin was large). These findings suggest that either delta psi, delta pH, or a combination can drive glutamate uptake, but to different degrees. In the presence of 4 mM Cl-, where uptake is optimal, both delta psi and delta pH contribute to the driving force for uptake. When the extravesicular pH was increased from 7.4 to 8.0, more Cl- was required to stimulate vesicular glutamate uptake. In the absence of Cl-, as extravesicular pH was lowered to 6.8, uptake was over 3-fold greater than it was at pH 7.4. As extravesicular pH was reduced from 8.0 toward 6.8, less Cl- was required for maximal stimulation. Decreasing the extravesicular pH from 8.0 to 6.8 in the absence of Cl- significantly increased glutamate uptake activity, even

  17. Data collection and analysis strategies for phMRI.

    PubMed

    Mandeville, Joseph B; Liu, Christina H; Vanduffel, Wim; Marota, John J A; Jenkins, Bruce G

    2014-09-01

    Although functional MRI traditionally has been applied mainly to study changes in task-induced brain function, evolving acquisition methodologies and improved knowledge of signal mechanisms have increased the utility of this method for studying responses to pharmacological stimuli, a technique often dubbed "phMRI". The proliferation of higher magnetic field strengths and the use of exogenous contrast agent have boosted detection power, a critical factor for successful phMRI due to the restricted ability to average multiple stimuli within subjects. Receptor-based models of neurovascular coupling, including explicit pharmacological models incorporating receptor densities and affinities and data-driven models that incorporate weak biophysical constraints, have demonstrated compelling descriptions of phMRI signal induced by dopaminergic stimuli. This report describes phMRI acquisition and analysis methodologies, with an emphasis on data-driven analyses. As an example application, statistically efficient data-driven regressors were used to describe the biphasic response to the mu-opioid agonist remifentanil, and antagonism using dopaminergic and GABAergic ligands revealed modulation of the mesolimbic pathway. Results illustrate the power of phMRI as well as our incomplete understanding of mechanisms underlying the signal. Future directions are discussed for phMRI acquisitions in human studies, for evolving analysis methodologies, and for interpretative studies using the new generation of simultaneous PET/MRI scanners. This article is part of the Special Issue Section entitled 'Neuroimaging in Neuropharmacology'.

  18. Data Collection and Analysis Strategies for phMRI

    PubMed Central

    Mandeville, Joseph B.; Liu, Christina H.; Vanduffel, Wim; Marota, John J.A.; Jenkins, Bruce G.

    2014-01-01

    Although functional MRI traditionally has been applied mainly to study changes in task-induced brain function, evolving acquisition methodologies and improved knowledge of signal mechanisms have increased the utility of this method for studying responses to pharmacological stimuli, a technique often dubbed “phMRI”. The proliferation of higher magnetic field strengths and the use of exogenous contrast agent have boosted detection power, a critical factor for successful phMRI due to the restricted ability to average multiple stimuli within subjects. Receptor-based models of neurovascular coupling, including explicit pharmacological models incorporating receptor densities and affinities and data-driven models that incorporate weak biophysical constraints, have demonstrated compelling descriptions of phMRI signal induced by dopaminergic stimuli. This report describes phMRI acquisition and analysis methodologies, with an emphasis on data-driven analyses. As an example application, statistically efficient data-driven regressors were used to describe the biphasic response to the mu-opioid agonist remifentanil, and antagonism using dopaminergic and GABAergic ligands revealed modulation of the mesolimbic pathway. Results illustrate the power of phMRI as well as our incomplete understanding of mechanisms underlying the signal. Future directions are discussed for phMRI acquisitions in human studies, for evolving analysis methodologies, and for interpretative studies using the new generation of simultaneous PET/MRI scanners. PMID:24613447

  19. Monitoring pH and ORP in a SHARON reactor.

    PubMed

    Claros, J; Serralta, J; Seco, A; Ferrer, J; Aguado, D

    2011-01-01

    This paper analyses the valuable information provided by the on-line measurements of pH and oxidation reduction potential (ORP) in a continuous single high ammonia removal over nitrite (SHARON) reactor. A laboratory-scale SHARON reactor equipped with pH, ORP, electric conductivity and dissolved oxygen (DO) probes has been operated for more than one year. Nitrogen removal over nitrite has been achieved by adding methanol at the beginning of anoxic stages. Time evolution of pH and ORP along each cycle allows identifying the decrease in nitritation rate when ammonia is consumed during the aerobic phase and the end of the denitrification process during the anoxic phase. Therefore, monitoring pH and ORP can be used to develop a real-time control system aimed at optimizing the length of both aerobic and anoxic stages. Real-time control of methanol addition can be carried out by using the information provided by these probes: excessive methanol addition in the anoxic stage is clearly detected in the ORP profile of the following aerobic phase, while a deficit of methanol is detected in both pH and ORP profiles of that anoxic phase. Moreover, other valuable information such as the amount of ammonia nitrified, failures in DO measurements, excessive stirring during the anoxic stage and methanol dosage in the aerobic phase was also provided by the pH and ORP profiles.

  20. Automated high precision secondary pH measurements

    NASA Astrophysics Data System (ADS)

    Bastkowski, F.; Jakobsen, P. T.; Stefan, F.; Kristensen, H. B.; Jensen, H. D.; Kawiecki, R.; Wied, C. E.; Kauert, A.; Seidl, B.; Spitzer, P.; Eberhardt, R.; Adel, B.

    2013-04-01

    A new setup for high precision, automated secondary pH measurements together with a reference measurement procedure has been developed and tested in interlaboratory comparisons using buffers pH 4.005, pH 7.000, and pH 10.012 at 25 °C and 37 °C. Using primary buffers as standards, a standard uncertainty in pH better than 0.005 can be reached. The central measuring device is a one piece, thermostatted cell of PFA (perfluoroalkoxy) with a built-in Hamilton® Single Pore™ Glass electrode. Due to its flow-through principle this device allows pH measurements with low consumption of measurement solutions. The very hydrophobic and smooth PFA as construction material facilitates complete emptying of the cell. Furthermore, the tempering unit affords very precise temperature control and hence contributes to the low target uncertainty of the produced secondary buffer solutions. Use of a symmetric measurement sequence and the two point calibration was sufficient to reach high precision and accuracy.

  1. Structure of human saposin A at lysosomal pH

    SciTech Connect

    Hill, Chris H.; Read, Randy J.; Deane, Janet E.

    2015-06-27

    A 1.8 Å resolution structure of the sphingolipid activator protein saposin A has been determined at pH 4.8, the physiologically relevant lysosomal pH for hydrolase enzyme activation and lipid-transfer activity. The saposins are essential cofactors for the normal lysosomal degradation of complex glycosphingolipids by acid hydrolase enzymes; defects in either saposin or hydrolase function lead to severe metabolic diseases. Saposin A (SapA) activates the enzyme β-galactocerebrosidase (GALC), which catalyzes the breakdown of β-d-galactocerebroside, the principal lipid component of myelin. SapA is known to bind lipids and detergents in a pH-dependent manner; this is accompanied by a striking transition from a ‘closed’ to an ‘open’ conformation. However, previous structures were determined at non-lysosomal pH. This work describes a 1.8 Å resolution X-ray crystal structure determined at the physiologically relevant lysosomal pH 4.8. In the absence of lipid or detergent at pH 4.8, SapA is observeed to adopt a conformation closely resembling the previously determined ‘closed’ conformation, showing that pH alone is not sufficient for the transition to the ‘open’ conformation. Structural alignments reveal small conformational changes, highlighting regions of flexibility.

  2. Salivary pH changes during 10% carbamide peroxide bleaching.

    PubMed

    Leonard, R H; Bentley, C D; Haywood, V B

    1994-08-01

    The purpose of this study was to evaluate the effect on salivary pH of a 10% carbamide peroxide solution when used with a custom-fitted guard for bleaching teeth. Baseline pH values were established for unstimulated saliva and on saliva produced while wearing an empty guard. After insertion of a guard half filled with Proxigel, salivary pH measurements were made at 5-minute intervals until the values returned to baseline levels. Mean salivary pH values were 6.81 +/- 0.11 for unstimulated samples and 6.91 +/- 0.18 after insertion of the empty guard. After insertion of the filled guard, there was a statistically insignificant decrease in salivary pH during the first 5 minutes, followed by an increase above baseline at 10 minutes, to a mean peak value of 7.32 +/- 0.27 at 15 minutes. The difference between the baseline values and the mean peak value at 15 minutes was statistically significant. The results of the study indicated that the pH of saliva increased significantly during the first 15 minutes of nightguard vital bleaching and did not significantly drop below baseline in the first 2 hours after insertion with a moderately low-pH solution.

  3. pH sensing using boron doped diamond electrodes.

    PubMed

    Fierro, Stéphane; Mitani, Naoko; Comninellis, Christos; Einaga, Yasuaki

    2011-10-06

    The boron doped diamond (BDD) electrode is presented as an appropriate candidate for next generation glass-free, highly stable and accurate pH sensors. The method used in this study is based on the potential change related to the hydrogen evolution reaction following a current step, which is pH dependent. Alkali cations in the solution have no influence on the accuracy of the pH calibration curve, which provides an advantage with respect to the conventional pH glass electrode. The unwanted influence of electrochemically active compounds in solution can be avoided by adjusting the current density applied during chronopotentiometric measurements. The accuracy of the pH measurements is due to the excellent stability as well as the wide potential window and low background current of BDD electrodes. This faculty was not observed when using conventional electrode materials. The efficacy of this new type of pH sensor has been tested using tap water as a typical real sample.

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

    SciTech Connect

    Palumbo, Anthony Vito; Phillips, Jana Randolph; Fagan, Lisa Anne; Drake, Meghan M; Ruther, Rose Emily; Fisher, L. Suzanne; Amonette, J. E.

    2007-01-01

    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.

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

    SciTech Connect

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

    2007-07-01

    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.

  6. Characterisation and deployment of an immobilised pH sensor spot towards surface ocean pH measurements.

    PubMed

    Clarke, Jennifer S; Achterberg, Eric P; Rérolle, Victoire M C; Abi Kaed Bey, Samer; Floquet, Cedric F A; Mowlem, Matthew C

    2015-10-15

    The oceans are a major sink for anthropogenic atmospheric carbon dioxide, and the uptake causes changes to the marine carbonate system and has wide ranging effects on flora and fauna. It is crucial to develop analytical systems that allow us to follow the increase in oceanic pCO2 and corresponding reduction in pH. Miniaturised sensor systems using immobilised fluorescence indicator spots are attractive for this purpose because of their simple design and low power requirements. The technology is increasingly used for oceanic dissolved oxygen measurements. We present a detailed method on the use of immobilised fluorescence indicator spots to determine pH in ocean waters across the pH range 7.6-8.2. We characterised temperature (-0.046 pH/°C from 5 to 25 °C) and salinity dependences (-0.01 pH/psu over 5-35), and performed a preliminary investigation into the influence of chlorophyll on the pH measurement. The apparent pKa of the sensor spots was 6.93 at 20 °C. A drift of 0.00014 R (ca. 0.0004 pH, at 25 °C, salinity 35) was observed over a 3 day period in a laboratory based drift experiment. We achieved a precision of 0.0074 pH units, and observed a drift of 0.06 pH units during a test deployment of 5 week duration in the Southern Ocean as an underway surface ocean sensor, which was corrected for using certified reference materials. The temperature and salinity dependences were accounted for with the algorithm, R=0.00034-0.17·pH+0.15·S(2)+0.0067·T-0.0084·S·1.075. This study provides a first step towards a pH optode system suitable for autonomous deployment. The use of a short duration low power illumination (LED current 0.2 mA, 5 μs illumination time) improved the lifetime and precision of the spot. Further improvements to the pH indicator spot operations include regular application of certified reference materials for drift correction and cross-calibration against a spectrophotometric pH system. Desirable future developments should involve novel

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

    PubMed

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

    2010-01-01

    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.

  8. A computer program for correlating dental plaque pH values, cH+, plaque titration, critical pH, resting pH and the solubility of enamel apatite.

    PubMed

    Larsen, M J; Pearce, E I

    1997-07-01

    A computer program was written in Visual Basic (Microsoft) to calculate (a) the area between a plaque pH curve (as seen after a sucrose rinse) and either a resting pH (around pH 7) or a critical pH value (around 5.5) above at least parts of the pH curve; (b) the solubility of apatite at the pH values in plaque; (c) the area between the plaque pH solubility curve and the apatite solubility at the resting pH/critical pH; (d) the area between plaque cH+ curve and the cH+ value at resting pH/ critical pH; and (e) the area between a plaque pH curve and a cut-off pH value below the curve, e.g. pH 3. It was found that because both the cH+ and the solubility of apatite increased logarithmically with a pH drop, the two latter area functions (d, e) were basically different from those based directly on pH curves. Thus, pH changes around the resting pH value had little effect on areas calculated from concentrations of H+ and solubility. In contrast, a small pH change around pH 4 had a strong impact on both demineralization potential and areas based on cH+. Also, because of the logarithmic nature, demineralization potentials were generally large in comparison to remineralization potentials, a point that has hitherto received little attention.

  9. Coral calcifying fluid pH is modulated by seawater carbonate chemistry not solely seawater pH.

    PubMed

    Comeau, S; Tambutté, E; Carpenter, R C; Edmunds, P J; Evensen, N R; Allemand, D; Ferrier-Pagès, C; Tambutté, S; Venn, A A

    2017-01-25

    Reef coral calcification depends on regulation of pH in the internal calcifying fluid (CF) in which the coral skeleton forms. However, little is known about calcifying fluid pH (pHCF) regulation, despite its importance in determining the response of corals to ocean acidification. Here, we investigate pHCF in the coral Stylophora pistillata in seawater maintained at constant pH with manipulated carbonate chemistry to alter dissolved inorganic carbon (DIC) concentration, and therefore total alkalinity (AT). We also investigate the intracellular pH of calcifying cells, photosynthesis, respiration and calcification rates under the same conditions. Our results show that despite constant pH in the surrounding seawater, pHCF is sensitive to shifts in carbonate chemistry associated with changes in [DIC] and [AT], revealing that seawater pH is not the sole driver of pHCF Notably, when we synthesize our results with published data, we identify linear relationships of pHCF with the seawater [DIC]/[H(+)] ratio, [AT]/ [H(+)] ratio and [[Formula: see text

  10. Ligand accessibility and bioactivity of a hormone–dendrimer conjugate depend on pH and pH history

    SciTech Connect

    Kim, Sung Hoon; Madak-Erdogan, Zeynep; Bae, Sung Chul; Carlson, Kathryn E.; Mayne, Christopher G.; Granick, Steve; Katzenellenbogen, Benita S.; Katzenellenbogen, John A.

    2015-07-17

    Estrogen conjugates with a polyamidoamine (PAMAM) dendrimer have shown remarkably selective regulation of the nongenomic actions of estrogens in target cells in this paper. In response to pH changes, however, these estrogen–dendrimer conjugates (EDCs) display a major morphological transition that alters the accessibility of the estrogen ligands that compromises the bioactivity of the EDC. A sharp break in dynamic behavior near pH 7 occurs for three different ligands on the surface of a PAMAM-G6 dendrimer: a fluorophore (tetramethylrhodamine [TMR]) and two estrogens (17α-ethynylestradiol and diphenolic acid). Collisional quenching and time-resolved fluorescence anisotropy experiments with TMR–PAMAM revealed high ligand shielding above pH 7 and low shielding below pH 7. Furthermore, when the pH was cycled from 8.5 (conditions of ligand–PAMAM conjugation) to 4.5 (e.g., endosome/lysosome) and through 6.5 (e.g., hypoxic environment) back to pH 8.5, the 17α-ethynylestradiol– and diphenolic acid–PAMAM conjugates experienced a dramatic, irreversible loss in cell stimulatory activity; dynamic NMR studies indicated that the hormonal ligands had become occluded within the more hydrophobic core of the PAMAM dendrimer. Thus, the active state of these estrogen–dendrimer conjugates appears to be metastable. Finally, this pH-dependent irreversible masking of activity is of considerable relevance to the design of drug conjugates with amine-bearing PAMAM dendrimers.

  11. Effect of systemic pH on pH sub i and lactic acid generation in exhaustive forearm exercise

    SciTech Connect

    Hood, V.L.; Schubert, C.; Keller, U.; Mueller, S. Univ. of Vermont College of Medicine, Burlington )

    1988-09-01

    To investigate whether changes in systemic pH affect intracellular pH (pH{sub i}), energy-rich phosphates, and lactic acid generation in muscle, eight normal volunteers performed exhaustive forearm exercise with arterial blood flow occluded for 2 min on three occasions. Subjects ingested 4 mmol/kg NH{sub 4}Cl (acidosis; A) or NaHCO{sub 3} (alkalosis; B) or nothing (control; C) 3 h before the exercise. Muscle pH{sub i} and phosphocreatine (PCr) content were measured with {sup 31}P-nuclear magnetic resonance ({sup 31}P-NMR) spectroscopy during exercise and recovery. Lactate output during 0.5-7 min of recovery was calculated as deep venous-arterial concentration differences times forearm blood flow. Before exercise, blood pH and bicarbonate were lower in acidosis than alkalosis and intermediate in control. Lactic acid output during recovery was less with A than B and intermediate in C. PCr utilization and resynthesis were not affected by extracellular pH changes. pH{sub i} did not differ before exercise or at its end. Hence systemic acidosis inhibited and alkalosis stimulated lactic acid output. These findings suggest that systemic pH regulates cellular acid production, protecting muscle pH, at the expense of energy availability.

  12. pH influences the biocompatibility of methylene blue solutions.

    PubMed

    Gusman, David Jonathan Rodrigues; Cintra, Luciano Tavares Angelo; Novaes, Vivian Cristina Noronha; Matheus, Henrique Rinaldi; de Araujo, Nathália Januario; de Almeida, Juliano Milanezi

    2017-05-23

    The aim of this study was to investigate the biocompatibility of methylene blue at different pH levels through the method of implantation in subcutaneous tissue. Eighty-four sterilized polyethylene tubes were allocated in the subcutaneous tissue of 28 rats, each one receiving four tubes, set into four groups: group tube (G-T)-empty tube, fibrin group (G-F)-tube filled with fibrin sponge, group methylene blue pH 7 (G-MB/pH 7)-tube filled with fibrin sponge soaked by methylene blue (100 μg/ml) at pH 7.0, and group methylene blue pH 1 (G-MB/pH 1)-tube filled with fibrin sponge and soaked by methylene blue (100 μg/ml) at pH 1.0. After 7, 15, and 30 days, seven animals from each group were euthanized, and the tubes involved by the surrounding tissue were removed and fixed with 4% buffered formaldehyde solution. The collected pieces were processed and histological sections (4 μm) were stained with hematoxylin and eosin and analyzed by light microscopy. Scores were assigned to analysis of histopathologic parameters. The results were statistically analyzed by the Kruskal-Wallis test (p ≤ 0.05). At 7 and 30 days, the G-MB/pH 1 group showed no significant difference in the G-T control group, while G-MB/pH 7 had a significant increase on tissue reaction, also when compared to G-T. At 15 days, there was no statistical difference between the groups. Within the limits of this study, it is concluded that methylene blue at pH 1.0 provides better biocompatibility than at pH 7.0.

  13. DIGESTION PRODUCTS OF THE PH20 HYALURONIDASE INHIBIT REMYELINATION

    PubMed Central

    Preston, Marnie; Gong, Xi; Su, Weiping; Matsumoto, Steven G.; Banine, Fatima; Winkler, Clayton; Foster, Scott; Xing, Rubing; Struve, Jaime; Dean, Justin; Baggenstoss, Bruce; Weigel, Paul H.; Montine, Thomas J.; Back, Stephen A.; Sherman, Larry S.

    2012-01-01

    OBJECTIVE Oligodendrocyte progenitor cells (OPCs) recruited to demyelinating lesions often fail to mature into oligodendrocytes (OLs) that remyelinate spared axons. The glycosaminoglycan hyaluronan (HA) accumulates in demyelinating lesions and has been implicated in the failure of OPC maturation and remyelination. We tested the hypothesis that OPCs in demyelinating lesions express a specific hyaluronidase, and that digestion products of this enzyme inhibit OPC maturation. METHODS Mouse OPCs grown in vitro were analyzed for hyaluronidase expression and activity. Gain of function studies were used to define the hyaluronidases that blocked OPC maturation. Mouse and human demyelinating lesions were assessed for hyaluronidase expression. Digestion products from different hyaluronidases and a hyaluronidase inhibitor were tested for their effects on OPC maturation and functional remyelination in vivo. RESULTS OPCs demonstrated hyaluronidase activity in vitro and expressed multiple hyaluronidases including HYAL1, HYAL2, and PH20. HA digestion by PH20 but not other hyaluronidases inhibited OPC maturation into OLs. In contrast, inhibiting HA synthesis did not influence OPC maturation. PH20 expression was elevated in OPCs and reactive astrocytes in both rodent and human demyelinating lesions. HA-digestion products generated by the PH20 hyaluronidase but not another hyaluronidase inhibited remyelination following lysolecithin-induced demyelination. Inhibition of hyaluronidase activity lead to increased OPC maturation and promoted increased conduction velocities through lesions. INTERPRETATION We determined that PH20 is elevated in demyelinating lesions and that increased PH20 expression is sufficient to inhibit OPC maturation and remyelination. Pharmacological inhibition of PH20 may therefore be an effective way to promote remyelination in multiple sclerosis and related conditions. PMID:23463525

  14. PH5 for integrating and archiving different data types

    NASA Astrophysics Data System (ADS)

    Azevedo, Steve; Hess, Derick; Beaudoin, Bruce

    2016-04-01

    PH5 is IRIS PASSCAL's file organization of HDF5 used for seismic data. The extensibility and portability of HDF5 allows the PH5 format to evolve and operate on a variety of platforms and interfaces. To make PH5 even more flexible, the seismic metadata is separated from the time series data in order to achieve gains in performance as well as ease of use and to simplify user interaction. This separation affords easy updates to metadata after the data are archived without having to access waveform data. To date, PH5 is currently used for integrating and archiving active source, passive source, and onshore-offshore seismic data sets with the IRIS Data Management Center (DMC). Active development to make PH5 fully compatible with FDSN web services and deliver StationXML is near completion. We are also exploring the feasibility of utilizing QuakeML for active seismic source representation. The PH5 software suite, PIC KITCHEN, comprises in-field tools that include data ingestion (e.g. RefTek format, SEG-Y, and SEG-D), meta-data management tools including QC, and a waveform review tool. These tools enable building archive ready data in-field during active source experiments greatly decreasing the time to produce research ready data sets. Once archived, our online request page generates a unique web form and pre-populates much of it based on the metadata provided to it from the PH5 file. The data requester then can intuitively select the extraction parameters as well as data subsets they wish to receive (current output formats include SEG-Y, SAC, mseed). The web interface then passes this on to the PH5 processing tools to generate the requested seismic data, and e-mail the requester a link to the data set automatically as soon as the data are ready. PH5 file organization was originally designed to hold seismic time series data and meta-data from controlled source experiments using RefTek data loggers. The flexibility of HDF5 has enabled us to extend the use of PH5 in several

  15. Microphone-Independent Robust Signal Processing Using Probabilistic Optimum Filtering

    DTIC Science & Technology

    1994-01-01

    11. A. Acero , "Acoustical and Environmental Robustness in Automatic Speech Recognition," Ph.D. Thesis, Carnegie-MeLton University, Sep- tember 1990...12. R.M. Stem, FJ-I. Leu, Y. Ohshima, T.M. Sullivan, and A. Acero , "Multiple Approaches to Robust Speech Recognition," 1992 Interna- tional

  16. Monitoring the Productivity of Coastal Systems Using PH ...

    EPA Pesticide Factsheets

    The impact of nutrient inputs to the eutrophication of coastal ecosystems has been one of the great themes of coastal ecology. There have been countless studies devoted to quantifying how human sources of nutrients, in particular nitrogen (N), effect coastal water bodies. These studies, which often measure in situ concentrations of nutrients, chlorophyll, and dissolved oxygen, are often spatially and/or temporally intensive and expensive. We provide evidence from experimental mesocosms, coupled with data from the water column of a well-mixed estuary, that pH can be a quick, inexpensive, and integrative measure of net ecosystem metabolism. In some cases, this approach is a more sensitive tracer of production than direct measurements of chlorophyll and carbon-14. Taken together, our data suggest that pH is a sensitive, but often overlooked, tool for monitoring estuarine production. This presentation will explore the potential utility of pH as an indicator of ecosystem productivity. Our data suggest that pH is a sensitive and potentially integrator of net ecosystem production. It should not be overlooked, that measuring pH is quick, easy, and inexpensive, further increasing its value as an analytical tool.

  17. Interfacial pH during mussel adhesive plaque formation

    PubMed Central

    Rodriguez, Nadine R. Martinez; Das, Saurabh; Kaufman, Yair; Israelachvili, Jacob N.; Waite, J. Herbert

    2015-01-01

    Mussel (Mytilus californianus) adhesion to marine surfaces involves an intricate and adaptive synergy of molecules and spatio-temporal processes. Although the molecules, such as mussel foot proteins (mfps), are well characterized, deposition details remain vague and speculative. Developing methods for the precise surveillance of conditions that apply during mfp deposition would aid both in understanding mussel adhesion and translating this adhesion into useful technologies. To probe the interfacial pH at which mussels buffer the local environment during mfp deposition, a lipid bilayer with tethered pH-sensitive fluorochromes was assembled on mica. The interfacial pH during foot contact with modified mica ranged from 2.2−3.3, which is well below the seawater pH of ~8. The acidic pH serves multiple functions: it limits mfp-Dopa oxidation, thereby enabling the catecholic functionalities to adsorb to surface oxides by H-bonding and metal ion coordination, and provides a solubility switch for mfps, most of which aggregate at pH ≥ 7-8. PMID:25875963

  18. pH responsive graft copolymers of chitosan.

    PubMed

    Yilmaz, Elvan; Yalinca, Zulal; Yahya, Kovan; Sirotina, Uliana

    2016-09-01

    Grafting suitable polymers onto chitosan can produce cationic or polyampholyte polymers or hydrogels that are potential smart biomedical materials. Chitosan-graft-[poly(diethylamino)ethyl methacrylate] has been prepared in three different physical forms as linear free chains in solution, chemical gels crosslinked with glutaraldehyde, and poly(diethylamino)ethyl methacrylate] grafted onto chitosan tripolyphosphate gel beads. In addition to chemical structure, the graft copolymers were characterized with respect to their dissolution and swelling behavior in aqueous solution. It has been established that solubility of the products is controlled by the grafting yield. While pH sensitive polymers, which collapse at a given pH value are obtained at lower grafting yields, hydrogels form at higher grafting yields with pH responsive swelling behavior. Glutaraldehyde crosslinked chitosan-graft-[poly(diethylamino)ethyl methacrylate] gels and chitosan tripolyphosphate gel beads grafted with poly[(diethylamino)ethyl methacrylate] exhibit pH sensitive swelling with highest equilibrium swelling capacity at pH=1.2.

  19. Near-infrared noninvasive spectroscopic determination of pH

    DOEpatents

    Alam, Mary K.; Robinson, Mark R.

    1998-08-11

    Methods and apparatus for, preferably, determining noninvasively and in vitro pH in a human. The non-invasive method includes the steps of: generating light at three or more different wavelengths in the range of 1000 nm to 2500 nm; irradiating blood containing tissue; measuring the intensities of the wavelengths emerging from the blood containing tissue to obtain a set of at least three spectral intensities v. wavelengths; and determining the unknown values of pH. The determination of pH is made by using measured intensities at wavelengths that exhibit change in absorbance due to histidine titration. Histidine absorbance changes are due to titration by hydrogen ions. The determination of the unknown pH values is performed by at least one multivariate algorithm using two or more variables and at least one calibration model. The determined pH values are within the physiological ranges observed in blood containing tissue. The apparatus includes a tissue positioning device, a source, at least one detector, electronics, a microprocessor, memory, and apparatus for indicating the determined values.

  20. Interfacial pH during mussel adhesive plaque formation.

    PubMed

    Martinez Rodriguez, Nadine R; Das, Saurabh; Kaufman, Yair; Israelachvili, Jacob N; Waite, J Herbert

    2015-01-01

    Mussel (Mytilus californianus) adhesion to marine surfaces involves an intricate and adaptive synergy of molecules and spatio-temporal processes. Although the molecules, such as mussel foot proteins (mfps), are well characterized, deposition details remain vague and speculative. Developing methods for the precise surveillance of conditions that apply during mfp deposition would aid both in understanding mussel adhesion and translating this adhesion into useful technologies. To probe the interfacial pH at which mussels buffer the local environment during mfp deposition, a lipid bilayer with tethered pH-sensitive fluorochromes was assembled on mica. The interfacial pH during foot contact with modified mica ranged from 2.2 to 3.3, which is well below the seawater pH of ~ 8. The acidic pH serves multiple functions: it limits mfp-Dopa oxidation, thereby enabling the catecholic functionalities to adsorb to surface oxides by H-bonding and metal ion coordination, and provides a solubility switch for mfps, most of which aggregate at pH ≥ 7-8.