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Displaying 1 - 25 of 1644

Amorphous Calcium Phosphate

November 1, 2001
Author(s)
Laurence C. Chow, E D. Eanes
… those that are composed principally of calcium and phosphate are most abundant in the teeth and exoskeletal … invertebrates. The existence of similar amorphous calcium phosphate (ACP) minerals in vertebrate organisms, on the … Amorphous Calcium Phosphate … Amorphous calcium phosphate, apatite, calcium phosphates, calification, …

Interfacial Properties of Hydroxyapatite Fluoroapatite and Octacalcium Phosphate

October 1, 2001
Author(s)
Ming S. Tung, Drago Skrtic
… The surface properties of calcium phosphate salts, such as hydroxyapatite (OHAp), fluoroapatite (Fap) and octacalcium phosphate (OCP), determine their overall interfacial … Properties of Hydroxyapatite Fluoroapatite and Octacalcium Phosphate … charge, fluoroapatite, hydroxyapatite, octacalcium phosphate, surface composition …

High Pressure Release and Dispersion of Hydrogen in a Partially Enclosed Compartment

March 1, 2011
Author(s)
Kuldeep R. Prasad, Thomas G. Cleary, William M. Pitts, Jiann C. Yang
… The study of compressed hydrogen release from high-pressure storage systems has practical application for hydrogen and fuel cell technologies. Such releases may occur … connecting piping, or direct PRD releases. Understanding hydrogen behavior during and after the unintended release …

The Influence Of Hydrogen On The Elastic Modulus And Anelastic Response Of Cold Worked Pure Iron

July 1, 2009
Author(s)
Richard E. Ricker, David J. Pitchure
… Understanding the influence of hydrogen on elastic deformation and anelastic response should contribute to our understanding of the influence of hydrogen on deformation and fracture. To accomplish this … samples of pure iron were cold-worked, charged with hydrogen, and examined in a dynamic mechanical analyzer. For …

COMPUTATIONAL MODELING OF HYDROGEN-ASSISTED FATIGUE CRACK GROWTH IN PIPELINE STEELS

July 31, 2017
Author(s)
Andrew Slifka, Robert L. Amaro, Elizabeth S. Drexler, Devin T. O'Connor, Benjamin E. Long
… In this work we further develop a model to predict hydrogen-assisted fatigue crack growth in steel pipelines and … elastic-plastic constitutive model in conjunction with a hydrogen diffusion model to predict the deformation and concentration of hydrogen around a fatigue crack tip. The hydrogen …

APPLICATION OF A MODEL OF HYDROGEN-ASSISTED FATIGUE CRACK GROWTH IN 4130 STEEL

July 31, 2017
Author(s)
Andrew Slifka, Robert L. Amaro, Devin T. O'Connor, Benjamin E. Long, Elizabeth S. Drexler
… lifetime of 4130 steel cylinders under the influence of hydrogen. This example is used to demonstrate the efficacy of … to be robust and incorporate features of stress-assisted hydrogen diffusion, large-scale plasticity, hydrogen gas pressure, loading frequency, and effects of …

Fatigue Crack Growth of Pipeline Steels in Gaseous Hydrogen- Predictive Model Calibrated to API-5L X52

September 9, 2012
Author(s)
Robert L. Amaro, Elizabeth S. Drexler, Neha N. Rustagi, Nicholas Nanninga, Yaakov Levy, Andrew J. Slifka
… the FCG of API-5L X100 steel in high-pressure gaseous hydrogen [1]. The model presumes that total FCG is a summation of a “pure” fatigue component and a hydrogen-assisted (HA) component. The hydrogen-assisted fatigue component is further divided into … 2012 International Hydrogen Conference …

A Thermodynamic Analysis of Refilling of a Hydrogen Tank

August 31, 2009
Author(s)
Jiann C. Yang
… A thermodynamic analysis of refilling of a gaseous hydrogen fuel tank is described. This study may lend itself to the applications of refilling a hydrogen storage tank onboard a hydrogen fuel cell vehicle. The gaseous hydrogen is treated … International Journal of Hydrogen Energy …

Comparison of hydrogen embrittlement in three pipeline steels in high pressure gaseous hydrogen environments

February 15, 2012
Author(s)
Nicholas Nanninga, Yaakov Levy, Elizabeth S. Drexler, Ryan Condon, April Stevenson, Andrew J. Slifka
… steels have been measured in a high pressure (13.8 MPa) hydrogen gas environment. Significant losses in elongation to … and reduction in area were observed when testing in hydrogen as compared with air, and those changes were … by noticeable changes in fracture morphology. For hydrogen charged specimens, surface crack initiation and …

Raman and FTIR Spectroscopies of Fluorescein in Solutions

August 1, 2001
Author(s)
Lili Wang, A. E. Roitberg, Curtis W. Meuse, Adolfas K. Gaigalas
… pH range from 9.1 to 5.4. At pH 9.1 fluorescein is in the dianion form. At pH 5.4, fluorescein is a mixture of monoanion ({approximately equal to} 85 %), dianion and neutral forms (together {approximately equal to} … %). The fluorescence quantum yield drops from 0.93 for the dianion form to 0.37 for the monoanion form. The Raman and …

A Water Setting Tetracalcium Phosphate- Dicalcium Phosphate Dihydrate Cement

November 1, 2004
Author(s)
Elena F. Burguera, F Guitian, Laurence C. Chow
… This paper reports the development of a calcium phosphate cement, comprising tetracalcium phosphate (TTCP) and dicalcium phosphate dihydrate (DCPD), that hardens in 14 min with water … calcium phosphate, calcium phosphate cement, hydroxyapatite, mechcanical properties, …

Vertical Release of Hydrogen in a Partially Enclosed Compartment : Role of Wind and Buoyancy

January 25, 2011
Author(s)
Kuldeep R. Prasad, William M. Pitts, Jiann C. Yang
… The natural and wind driven mixing and dispersion of hydrogen released in an accidental manner in a partially … to predict the entrainment of air in a buoyant turbulent hydrogen plume and the properties of the resulting two layer … the important physical processes involved during hydrogen release as a vertical plume, and dispersion in a …

TOWARDS A TEST METHOD FOR HYDROGEN SENSOR PERFORMANCE

April 2, 2008
Author(s)
Nathan D. Marsh, Thomas G. Cleary
… standard test methods for the performance of commercial hydrogen sensors, we employed the Fire Emulator / Detector … of a representative selection of commercially-available hydrogen sensors.  These sensors depend on a variety of …  They were evaluated both for their response to hydrogen concentrations up to half the lower flammability …

Premixed Calcium Phosphate Cement Pastes

November 1, 2003
Author(s)
Shozo Takagi, Laurence C. Chow, S Hirayama, A Sugawara
… A self-hardening calcium phosphate cement (CPC-I), consisting of tetracalcium phosphate (TTCP) and dicalcium phosphate anhydrous (DCPA), has been shown in clinical … dicalcium phosphate glycerol, hydroxyapatite, hydroxypropyl … physicochemical properties, self-hardening calcium phosphate cement, tetracalcium phosphate, thicalcium phosphate …

Effect of wind and buoyancy on hydrogen release and dispersion in a compartment with vents at multiple levels

November 30, 2010
Author(s)
Kuldeep R. Prasad, William M. Pitts, Jiann C. Yang
… The natural and forced mixing and dispersion of hydrogen released in an accidental manner in a partially … the important physical processes involved during hydrogen release and dispersion in a compartment with vents … parameters. Model results indicate that the steady state hydrogen volume fraction in the compartment is lower when the …

ON MATERIAL-BASED HYDROGEN STORAGE

August 1, 2008
Author(s)
Jiann C. Yang
… pressure in a would-be situation wherein a material-based hydrogen storage system is rendered closed.  Under several … International Journal of Hydrogen Energy … Hydrogen, Safety, Storage … ON MATERIAL-BASED HYDROGEN STORAGE …

Reduced Hardening Time of Calcium Phosphate Cements

October 16, 2008
Author(s)
Milenko Markovic, S. Takagi, Laurence C. Chow
… The first self-hardening calcium phosphate cement (CPC) consisting of tetracalcium phosphate (TTCP, Ca 4 (PO 4 ) 2 O) and dicalcium phosphate anhydrous (DCPA, CaHPO 4 ) or dicalcium phosphate … calcium, calcium phosphate cement, crystallinity, hardening time, …

NATURAL AND FORCED VENTILATION OF BUOYANT GAS RELEASED IN A FULL-SCALE GARAGE: COMPARISON OF MODEL PREDICTIONS AND EXPERIMENTAL DATA

December 19, 2011
Author(s)
Kuldeep R. Prasad, William M. Pitts, Marco G. Fernandez, Jiann C. Yang
… Increase in the number of hydrogen fueled applications in the marketplace will require … and explosion associated with the unintended release of hydrogen within a structure. Predicting the temporally evolving hydrogen concentration in a structure, with unknown release …

FATIGUE CRACK GROWTH RATES OF API X70 PIPELINE STEELS IN PRESSURIZED HYDROGEN GAS COMPARED WITH AN X52 PIPELINE IN HYDROGEN SERVICE

September 1, 2017
Author(s)
Elizabeth S. Drexler, Andrew J. Slifka, Robert L. Amaro, Damian S. Lauria, Jeffrey W. Sowards
… At the present time, steel selection for hydrogen pipelines is limited to API X52 grade. However, the … pipeline steel that is currently in service transporting hydrogen gas, as well as two X70 pipeline steels. The compact tension specimens were tested in hydrogen gas pressurized to 5.5 MPa or 34 MPa. A comparison …

Thermodynamics of the Hydrolysis Reactions of +--D-galactose 1-phosphate, sn-glycerol 3-phosphate, 4 nitrophenyl phosphate, phosphocreatine, and 3-phospho-D-glycerate

May 1, 2009
Author(s)
Robert N. Goldberg, Brian E. Lang, Catherine T. Lo, David J. Ross, Yadu D. Tewari
… been used to conduct a thermodynamic investigation of five phosphate hydrolysis reactions: α-D-galactose 1 phosphate(aq) + H2O(l) = D-galactose(aq) + orthophosphate(aq) (1), sn-glycerol 3-phosphate(aq) + H2O(l) = glycerol(aq) + orthophosphate(aq) … apparent equilibrium constants, ±-D-galactose 1-phosphate, sn-glycerol 3 phosphate, 4 nitrophenyl phosphate, …

FATIGUE CRACK GROWTH OF TWO X52 PIPELINE STEELS IN A PRESSURIZED HYDROGEN ENVIRONMENT

September 9, 2012
Author(s)
Andrew J. Slifka, Elizabeth S. Drexler, Neha N. Rustagi, Damian S. Lauria, Joseph D. McColskey, Robert L. Amaro
… One alloy was from a new linepipe that was installed for hydrogen service in 2011. The other alloy was from a vintage … results were compared with tests conducted in pressurized hydrogen gas. All tests were run at (load ratio) R = 0.5 and a frequency of 1 Hz. Tests were conducted at hydrogen pressures of 5.5 MPa and 34 MPa. A new method that …

Analysis of Thermodynamic Processes Involving Hydrogen

March 5, 2008
Author(s)
Jiann C. Yang, Marcia L. Huber
… thermodynamic processes involving the storage and use of hydrogen has been examined using the NIST REFPROP database. … when the exposure temperature is very close to the hydrogen autoignition temperature. … International Journal of Hydrogen Energy … autoignition, hydrogen, Joule-Thomson effect, thermodynamics …

Effect of the Calcium to Phosphate Ratio of TTCP on the Properties of a TTCP-DCPD Bone Cement

September 17, 2007
Author(s)
Elena F. Burguera, F Guitian, Laurence C. Chow
… Six different tetracalcium phosphate products were synthesized by solid state reaction … at high temperature by varying the overall calcium to phosphate ratio of the synthesis mixture. The objective was to evaluate the effect of the calcium to phosphate ratio on a TTCP-DCPD cement. The resulting six …
Displaying 1 - 25 of 1644
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