36 CFR 222.2 - Management of the range environment.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 36 Parks, Forests, and Public Property 2 2012-07-01 2012-07-01 false Management of the range environment. 222.2 Section 222.2 Parks, Forests, and Public Property FOREST SERVICE, DEPARTMENT OF AGRICULTURE... environment. (a) Allotments will be designated on the National Forest System and on other lands under Forest...

36 CFR 222.2 - Management of the range environment.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 36 Parks, Forests, and Public Property 2 2011-07-01 2011-07-01 false Management of the range environment. 222.2 Section 222.2 Parks, Forests, and Public Property FOREST SERVICE, DEPARTMENT OF AGRICULTURE... environment. (a) Allotments will be designated on the National Forest System and on other lands under Forest...

36 CFR 222.2 - Management of the range environment.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 36 Parks, Forests, and Public Property 2 2010-07-01 2010-07-01 false Management of the range environment. 222.2 Section 222.2 Parks, Forests, and Public Property FOREST SERVICE, DEPARTMENT OF AGRICULTURE... environment. (a) Allotments will be designated on the National Forest System and on other lands under Forest...

20 CFR 416.2222 - Confidentiality of information and records.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 20 Employees' Benefits 2 2010-04-01 2010-04-01 false Confidentiality of information and records. 416.2222 Section 416.2222 Employees' Benefits SOCIAL SECURITY ADMINISTRATION SUPPLEMENTAL SECURITY... comply with the provisions for confidentiality of information, including the security of systems, and...

33 CFR 222.2 - Acquisition of lands downstream from spillways for hydrologic safety purposes.

Code of Federal Regulations, 2010 CFR

2010-07-01

... CORPS OF ENGINEERS, DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE ENGINEERING AND DESIGN § 222.2... agencies having civil works responsibilities. (c) Reference. ER 405-2-150. (d) Discussion. A policy of... that would prevail without the project. General hydrologic engineering considerations are as follows...

33 CFR 222.2 - Acquisition of lands downstream from spillways for hydrologic safety purposes.

Code of Federal Regulations, 2013 CFR

2013-07-01

... CORPS OF ENGINEERS, DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE ENGINEERING AND DESIGN § 222.2... that would prevail without the project. General hydrologic engineering considerations are as follows... property. (iii) Flood durations are a maximum of 3 hours in urban areas and 24 hours in agricultural areas...

33 CFR 222.2 - Acquisition of lands downstream from spillways for hydrologic safety purposes.

Code of Federal Regulations, 2014 CFR

2014-07-01

... CORPS OF ENGINEERS, DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE ENGINEERING AND DESIGN § 222.2... that would prevail without the project. General hydrologic engineering considerations are as follows... property. (iii) Flood durations are a maximum of 3 hours in urban areas and 24 hours in agricultural areas...

33 CFR 222.2 - Acquisition of lands downstream from spillways for hydrologic safety purposes.

Code of Federal Regulations, 2012 CFR

2012-07-01

... CORPS OF ENGINEERS, DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE ENGINEERING AND DESIGN § 222.2... that would prevail without the project. General hydrologic engineering considerations are as follows... property. (iii) Flood durations are a maximum of 3 hours in urban areas and 24 hours in agricultural areas...

28 CFR 22.22 - Revelation of identifiable data.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 28 Judicial Administration 1 2012-07-01 2012-07-01 false Revelation of identifiable data. 22.22 Section 22.22 Judicial Administration DEPARTMENT OF JUSTICE CONFIDENTIALITY OF IDENTIFIABLE RESEARCH AND STATISTICAL INFORMATION § 22.22 Revelation of identifiable data. (a) Except as noted in paragraph (b) of this...

40 CFR 22.22 - Evidence.

Code of Federal Regulations, 2010 CFR

2010-07-01

... § 22.19 (a), (e) or (f) to all parties at least 15 days before the hearing date, the Presiding Officer... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Evidence. 22.22 Section 22.22... PERMITS Hearing Procedures § 22.22 Evidence. (a) General. (1) The Presiding Officer shall admit all...

40 CFR 22.22 - Evidence.

Code of Federal Regulations, 2012 CFR

2012-07-01

... § 22.19 (a), (e) or (f) to all parties at least 15 days before the hearing date, the Presiding Officer... 40 Protection of Environment 1 2012-07-01 2012-07-01 false Evidence. 22.22 Section 22.22... PERMITS Hearing Procedures § 22.22 Evidence. (a) General. (1) The Presiding Officer shall admit all...

40 CFR 22.22 - Evidence.

Code of Federal Regulations, 2011 CFR

2011-07-01

... § 22.19 (a), (e) or (f) to all parties at least 15 days before the hearing date, the Presiding Officer... 40 Protection of Environment 1 2011-07-01 2011-07-01 false Evidence. 22.22 Section 22.22... PERMITS Hearing Procedures § 22.22 Evidence. (a) General. (1) The Presiding Officer shall admit all...

40 CFR 22.22 - Evidence.

Code of Federal Regulations, 2014 CFR

2014-07-01

... § 22.19 (a), (e) or (f) to all parties at least 15 days before the hearing date, the Presiding Officer... 40 Protection of Environment 1 2014-07-01 2014-07-01 false Evidence. 22.22 Section 22.22... PERMITS Hearing Procedures § 22.22 Evidence. (a) General. (1) The Presiding Officer shall admit all...

40 CFR 22.22 - Evidence.

Code of Federal Regulations, 2013 CFR

2013-07-01

... § 22.19 (a), (e) or (f) to all parties at least 15 days before the hearing date, the Presiding Officer... 40 Protection of Environment 1 2013-07-01 2013-07-01 false Evidence. 22.22 Section 22.22... PERMITS Hearing Procedures § 22.22 Evidence. (a) General. (1) The Presiding Officer shall admit all...

33 CFR 222.2 - Acquisition of lands downstream from spillways for hydrologic safety purposes.

Code of Federal Regulations, 2011 CFR

2011-07-01

... CORPS OF ENGINEERS, DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE ENGINEERING AND DESIGN § 222.2... depth. (iii) Flood duration. (iv) Velocities. (v) Debris and erosion. (2) Determine the combinations of... hazardous and non-hazardous. Non-hazardous areas are defined as those areas where: (i) Flood depths are...

27 CFR 22.22 - Alternate methods or procedures; and emergency variations from requirements.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 27 Alcohol, Tobacco Products and Firearms 1 2012-04-01 2012-04-01 false Alternate methods or procedures; and emergency variations from requirements. 22.22 Section 22.22 Alcohol, Tobacco Products and... OF TAX-FREE ALCOHOL Administrative Provisions Authorities § 22.22 Alternate methods or procedures...

27 CFR 22.22 - Alternate methods or procedures; and emergency variations from requirements.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 27 Alcohol, Tobacco Products and Firearms 1 2014-04-01 2014-04-01 false Alternate methods or procedures; and emergency variations from requirements. 22.22 Section 22.22 Alcohol, Tobacco Products and... OF TAX-FREE ALCOHOL Administrative Provisions Authorities § 22.22 Alternate methods or procedures...

27 CFR 22.22 - Alternate methods or procedures; and emergency variations from requirements.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 27 Alcohol, Tobacco Products and Firearms 1 2011-04-01 2011-04-01 false Alternate methods or procedures; and emergency variations from requirements. 22.22 Section 22.22 Alcohol, Tobacco Products and... OF TAX-FREE ALCOHOL Administrative Provisions Authorities § 22.22 Alternate methods or procedures...

4 CFR 22.22 - Accelerated and Small Claims Procedures [Rule 22].

Code of Federal Regulations, 2013 CFR

2013-01-01

... 4 Accounts 1 2013-01-01 2013-01-01 false Accelerated and Small Claims Procedures [Rule 22]. 22.22 Section 22.22 Accounts GOVERNMENT ACCOUNTABILITY OFFICE GENERAL PROCEDURES RULES OF PROCEDURE OF THE GOVERNMENT ACCOUNTABILITY OFFICE CONTRACT APPEALS BOARD § 22.22 Accelerated and Small Claims Procedures [Rule...

27 CFR 22.22 - Alternate methods or procedures; and emergency variations from requirements.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 27 Alcohol, Tobacco Products and Firearms 1 2013-04-01 2013-04-01 false Alternate methods or procedures; and emergency variations from requirements. 22.22 Section 22.22 Alcohol, Tobacco Products and... OF TAX-FREE ALCOHOL Administrative Provisions Authorities § 22.22 Alternate methods or procedures...

4 CFR 22.22 - Accelerated and Small Claims Procedures [Rule 22].

Code of Federal Regulations, 2010 CFR

2010-01-01

... 4 Accounts 1 2010-01-01 2010-01-01 false Accelerated and Small Claims Procedures [Rule 22]. 22.22 Section 22.22 Accounts GOVERNMENT ACCOUNTABILITY OFFICE GENERAL PROCEDURES RULES OF PROCEDURE OF THE GOVERNMENT ACCOUNTABILITY OFFICE CONTRACT APPEALS BOARD § 22.22 Accelerated and Small Claims Procedures [Rule...

4 CFR 22.22 - Accelerated and Small Claims Procedures [Rule 22].

Code of Federal Regulations, 2011 CFR

2011-01-01

... 4 Accounts 1 2011-01-01 2011-01-01 false Accelerated and Small Claims Procedures [Rule 22]. 22.22 Section 22.22 Accounts GOVERNMENT ACCOUNTABILITY OFFICE GENERAL PROCEDURES RULES OF PROCEDURE OF THE GOVERNMENT ACCOUNTABILITY OFFICE CONTRACT APPEALS BOARD § 22.22 Accelerated and Small Claims Procedures [Rule...

4 CFR 22.22 - Accelerated and Small Claims Procedures [Rule 22].

Code of Federal Regulations, 2012 CFR

2012-01-01

... 4 Accounts 1 2012-01-01 2012-01-01 false Accelerated and Small Claims Procedures [Rule 22]. 22.22 Section 22.22 Accounts GOVERNMENT ACCOUNTABILITY OFFICE GENERAL PROCEDURES RULES OF PROCEDURE OF THE GOVERNMENT ACCOUNTABILITY OFFICE CONTRACT APPEALS BOARD § 22.22 Accelerated and Small Claims Procedures [Rule...

27 CFR 22.22 - Alternate methods or procedures; and emergency variations from requirements.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Alternate methods or procedures; and emergency variations from requirements. 22.22 Section 22.22 Alcohol, Tobacco Products and... OF TAX-FREE ALCOHOL Administrative Provisions Authorities § 22.22 Alternate methods or procedures...

Growth of crack-free GaN films on Si(111) substrate by using Al-rich AlN buffer layer

NASA Astrophysics Data System (ADS)

Lu, Yuan; Cong, Guangwei; Liu, Xianglin; Lu, Da-Cheng; Zhu, Qinsheng; Wang, Xiaohui; Wu, Jiejun; Wang, Zhanguo

2004-11-01

GaN epilayers were grown on Si(111) substrate by metalorganic chemical vapor deposition. By using the Al-rich AlN buffer which contains Al beyond stoichiometry, crack-free GaN epilayers with 1 μm thickness were obtained. Through x-ray diffraction (XRD) and secondary ion mass spectroscopy analyses, it was found that a lot of Al atoms have diffused into the under part of the GaN epilayer from the Al-rich AlN buffer, which results in the formation of an AlxGa1-xN layer at least with 300 nm thickness in the 1 μm thick GaN epilayer. The Al fraction x was estimated by XRD to be about 2.5%. X-ray photoelectron spectroscopy depth analysis was also applied to investigate the stoichiometry in the Al-rich buffer before GaN growth. It is suggested that the underlayer AlxGa1-xN originated from Al diffusion probably provides a compressive stress to the upper part of the GaN epilayer, which counterbalances a part of tensile stress in the GaN epilayer during cooling down and consequently reduces the cracks of the film effectively. The method using the Al diffusion effect to form a thick AlGaN layer is really feasible to achieve the crack-free GaN films and obtain a high crystal quality simultaneously.

Kinetic restriction of simple gases in porous carbons: transition-state theory study.

PubMed

Nguyen, Thanh X; Bhatia, Suresh K

2008-01-01

The separation of simple gases such as N2, Ar, CO2, and CH4 is an industrially important problem, particularly for the mitigation of greenhouse emissions. Furthermore, these gases are widely accepted as standard probing gases for the characterization of the microstructure of porous solids. However, a consistent set of microstructural parameters of a microporous solid determined from the use of adsorption measurements of these different gases is not always achieved because of differences in their pore accessibility. This is a long-standing and poorly understood problem. Here, we present the calculated results of the crossing time of N2, Ar, CO2, and CH4 between two neighboring cages through a constricted window in a realistic structural model of saccharose char, generated from hybrid reverse Monte Carlo (HRMC) simulation (Nguyen, T. X.; Bhatia, S. K.; Jain, S. K.; Gubbins, K. E. Mol. Simul. 2006, 32, 567-577) using transition state theory (TST), as described in our recent work (Nguyen, T. X.; Bhatia, S. K. J. Phys. Chem. 2007, 111, 2212-2222). The striking feature in these results is that whereas very fast diffusion of carbon dioxide within the temperature range of 273-343 K, with crossing time on the molecular dynamics scale (10-4-10-6 s), leads to instantaneous equilibrium and no hysteresis on the experimental time scale, slower diffusion of Ar and N2 at the low temperature of analysis indicates an accessibility problem. These results rationalize the experimental results of hysteresis for N2 at 77 K and Ar at 87 K but not for CO2 at 273 K in Takeda 3 A carbon molecular sieves. Furthermore, it is shown that CH4 diffusion through narrow pore mouths can be hindered even at ambient temperature. Finally, we show that the use of pore size and wall thickness distributions extracted from the adsorption of Ar at 87 K using the finite wall thickness (FWT) model (Nguyen, T. X.; Bhatia, S. K. Langmuir 2004, 20, 3532-3535 and Nguyen, T. X.; Bhatia, S. K. J. Phys. Chem. B 2004, 108, 14032-14042) provides the correct prediction of experimental CO2 adsorption in BPL and PCB carbons whereas that from N2 at 77 K gives a significant underprediction for both CO2 and CH4 in the BPL carbon. These trends are in excellent agreement with those predicted using the calculated crossing times.

Proposed quality control guidelines for antimicrobial susceptibility tests using tilmicosin.

PubMed Central

Shryock, T R; White, D W; Werner, C S; Staples, J M

1995-01-01

Quality control guidelines for tilmicosin, a novel veterinary-use-only macrolide, were developed in a multi-laboratory study according to established National Committee for Clinical Laboratory Standards (NCCLS) procedures (M23-T2). Tilmicosin was incorporated into Sensititre plates for broth microdilution endpoint testing and into two lots of 15-micrograms disks for Kirby-Bauer agar disk diffusion testing. One common lot and five unique lots of Mueller-Hinton media were used. (Broth was cation adjusted, and agar was supplemented with 5% defibrinated sheep blood.) Bacteria used for reference strains included Pasteurella haemolytica 128K, Pasteurella multocida ATCC 43137, and Staphylococcus aureus ATCC 29213 (microdilution) and ATCC 25923 (disk). Replicate tests were conducted. Disk diffusion and broth microdilution quality control ranges are proposed. PMID:7714188

29 CFR 22.22 - Exchange of witness lists, statements, and exhibits.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 29 Labor 1 2010-07-01 2010-07-01 true Exchange of witness lists, statements, and exhibits. 22.22 Section 22.22 Labor Office of the Secretary of Labor PROGRAM FRAUD CIVIL REMEDIES ACT OF 1986 § 22.22... statements that the party intends to offer in lieu of live testimony in accordance with § 22.33(b). At the...

29 CFR 22.22 - Exchange of witness lists, statements, and exhibits.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 29 Labor 1 2014-07-01 2013-07-01 true Exchange of witness lists, statements, and exhibits. 22.22 Section 22.22 Labor Office of the Secretary of Labor PROGRAM FRAUD CIVIL REMEDIES ACT OF 1986 § 22.22... statements that the party intends to offer in lieu of live testimony in accordance with § 22.33(b). At the...

29 CFR 22.22 - Exchange of witness lists, statements, and exhibits.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 29 Labor 1 2012-07-01 2012-07-01 false Exchange of witness lists, statements, and exhibits. 22.22 Section 22.22 Labor Office of the Secretary of Labor PROGRAM FRAUD CIVIL REMEDIES ACT OF 1986 § 22.22... statements that the party intends to offer in lieu of live testimony in accordance with § 22.33(b). At the...

29 CFR 22.22 - Exchange of witness lists, statements, and exhibits.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 29 Labor 1 2013-07-01 2013-07-01 false Exchange of witness lists, statements, and exhibits. 22.22 Section 22.22 Labor Office of the Secretary of Labor PROGRAM FRAUD CIVIL REMEDIES ACT OF 1986 § 22.22... statements that the party intends to offer in lieu of live testimony in accordance with § 22.33(b). At the...

29 CFR 22.22 - Exchange of witness lists, statements, and exhibits.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 29 Labor 1 2011-07-01 2011-07-01 false Exchange of witness lists, statements, and exhibits. 22.22 Section 22.22 Labor Office of the Secretary of Labor PROGRAM FRAUD CIVIL REMEDIES ACT OF 1986 § 22.22... statements that the party intends to offer in lieu of live testimony in accordance with § 22.33(b). At the...

All Prime Contract Awards by State or Country, Place, and Contractor. Part 15 (Amity N. Dakota-Tulsa Oklahoma)

DTIC Science & Technology

1990-01-01

m2 .m2 =~Z ZZ222* .=222* .=2222 moo 400 10 0 0- 0 0 00 0 0 OHp so 0I0moo 1.- r- .1 D 0> 00󈧬.1-N c>0In 0)(000-4-4 41) I 1 400 Y ’ 0 m’ -4 N-T 4101...0 00-4a4-4.-4-0 N 14 I 00 0) 0) 0) 0)0) 0)00) 0) MEM N1 C4 0) II 0) -4r- In r 00) Nl 0 In n Njo oo in -4 r-t-N a -4 o II I M) It -4MCMn"CNNN NOj 0 U00

28 CFR 22.22 - Revelation of identifiable data.

Code of Federal Regulations, 2013 CFR

2013-07-01

... sections 223(a)(12)(A), 223(a)(13), 223(a)(14), and 243 of the Juvenile Justice and Delinquency Prevention... 28 Judicial Administration 1 2013-07-01 2013-07-01 false Revelation of identifiable data. 22.22 Section 22.22 Judicial Administration DEPARTMENT OF JUSTICE CONFIDENTIALITY OF IDENTIFIABLE RESEARCH AND...

28 CFR 22.22 - Revelation of identifiable data.

Code of Federal Regulations, 2014 CFR

2014-07-01

... sections 223(a)(12)(A), 223(a)(13), 223(a)(14), and 243 of the Juvenile Justice and Delinquency Prevention... 28 Judicial Administration 1 2014-07-01 2014-07-01 false Revelation of identifiable data. 22.22 Section 22.22 Judicial Administration DEPARTMENT OF JUSTICE CONFIDENTIALITY OF IDENTIFIABLE RESEARCH AND...

34 CFR 222.66 - How does the Secretary determine whether a fiscally independent local educational agency is...

Code of Federal Regulations, 2010 CFR

2010-07-01

... independent LEA, as defined in § 222.2(c), is making a reasonable tax effort as required by § 222.63 or § 222... (referred to in this part as “tax rates”), as defined in § 222.2(c), with the tax rates of its generally... classification of real property is equal to at least 95 percent of each of the average tax rates of its generally...

34 CFR 222.66 - How does the Secretary determine whether a fiscally independent local educational agency is...

Code of Federal Regulations, 2011 CFR

2011-07-01

... independent LEA, as defined in § 222.2(c), is making a reasonable tax effort as required by § 222.63 or § 222... (referred to in this part as “tax rates”), as defined in § 222.2(c), with the tax rates of its generally... classification of real property is equal to at least 95 percent of each of the average tax rates of its generally...

40 CFR 85.2222 - On-board diagnostic test procedures.

Code of Federal Regulations, 2010 CFR

2010-07-01

.... 85.2222 Section 85.2222 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTROL OF AIR POLLUTION FROM MOBILE SOURCES Emission Control System Performance... inspected at the EPA Docket No. A-94-21 at EPA's Air Docket (LE-131), Room 1500 M, 1st Floor, Waterside Mall...

77 FR 53906 - Notice of Proposed Withdrawal and Opportunity for Public Meeting; California

Federal Register 2010, 2011, 2012, 2013, 2014

2012-09-04

...\\; Sec. 32, lots 4 and 5; Sec. 34, lot 4. T. 13 N., R. 10 E., Sec. 2, lot 1, and lots 3 to 15, inclusive; Sec. 9, lots 8, 12, and 13, and SW\\1/4\\NE\\1/4\\; Sec. 10, lots 1 to 10, inclusive, E\\1/2\\NE\\1/4\\, E\\1/2..., inclusive, S\\1/2\\ of lot 5, S\\1/2\\ of lot 8, lots 11 and 13; Sec. 19, lot 24; Sec. 20, lots 1, 2, 3, and 8...

76 FR 22012 - Amendment of Class E Airspace; Kokomo, IN

Federal Register 2010, 2011, 2012, 2013, 2014

2011-04-20

.../Cass County Airport, IN (Lat. 40[deg]42'41'' N., long. 86[deg]22'22'' W.) Peru Municipal Airport, IN...-mile radius of Peru Municipal Airport, and within a 6- mile radius of the Regional Health System...

Correlation of particle-induced displacement damage in silicon

NASA Astrophysics Data System (ADS)

Summers, G. P.; Dale, C. J.; Burke, E. A.; Wolicki, E. A.; Marshall, P. W.

1987-12-01

The effects of displacement damage caused in several types of silicon bipolar transistors by protons, deuterons, helium ions, and by 1-MeV-equivalent neutrons are considered. Measurements are compared to calculations of the nonionizing energy deposition in silicon as a function of particle type and energy. Measurements were made of displacement damage factors for 2N2222A and 2N2907A switching transistors, and for 2N3055, 2N6678, and 2N6547 power transistors, as a function of collector current using 3.7-175-MeV protons, 4.3-37-MeV deuterons, and 16.8-65-MeV helium ions. Long-term ionization effects on the value of the displacement damage factors were taken into account. In calculating the energy dependence of the nonionizing energy deposition, Rutherford, nuclear elastic, and nuclear inelastic interactions, and Lindhard energy partition were considered.

The development of a high sensitivity neutron displacement damage sensor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tonigan, Andrew M.; Parma, Edward J.; Martin, William J.

Here, the capability to characterize the neutron energy spectrum and fluence received by a test object is crucial to under-standing the damage effects observed in electronic components. For nuclear research reactors and high energy density physics fa-cilities this can pose exceptional challenges, especially with low level neutron fluences. An ASTM test method for characterizing neutron environments utilizes the 2N2222A transistor as a 1-MeV equivalent neutron fluence sensor and is applicable for environ-ments with 1 x 10 12 - 1 x 10 14 1-MeV(Si)-Eqv.-n/cm 2. In this work we seek to extend the range of this test method to lower fluencemore » environments utilizing the 2N1486 transistor. Here, the 2N1486 is shown to be an effective neutron displacement damage sensor as low as 1 x 10 10 1-MeV(Si)-Eqv.-n/cm 2.« less

The development of a high sensitivity neutron displacement damage sensor

DOE PAGES

Tonigan, Andrew M.; Parma, Edward J.; Martin, William J.

2016-11-23

Here, the capability to characterize the neutron energy spectrum and fluence received by a test object is crucial to under-standing the damage effects observed in electronic components. For nuclear research reactors and high energy density physics fa-cilities this can pose exceptional challenges, especially with low level neutron fluences. An ASTM test method for characterizing neutron environments utilizes the 2N2222A transistor as a 1-MeV equivalent neutron fluence sensor and is applicable for environ-ments with 1 x 10 12 - 1 x 10 14 1-MeV(Si)-Eqv.-n/cm 2. In this work we seek to extend the range of this test method to lower fluencemore » environments utilizing the 2N1486 transistor. Here, the 2N1486 is shown to be an effective neutron displacement damage sensor as low as 1 x 10 10 1-MeV(Si)-Eqv.-n/cm 2.« less

Crystal Structure and Catalytic Behavior in Olefin Epoxidation of a One-Dimensional Tungsten Oxide/Bipyridine Hybrid.

PubMed

Amarante, Tatiana R; Antunes, Margarida M; Valente, Anabela A; Paz, Filipe A Almeida; Pillinger, Martyn; Gonçalves, Isabel S

2015-10-19

The tungsten oxide/2,2'-bipyridine hybrid material [WO3(2,2'-bpy)]·nH2O (n = 1-2) (1) has been prepared in near quantitative yield by the reaction of H2WO4, 2,2'-bpy, and H2O in the mole ratio of ca. 1:2:700 at 160 °C for 98 h in a rotating Teflon-lined digestion bomb. The solid-state structure of 1 was solved and refined through Rietveld analysis of high-resolution synchrotron X-ray diffraction data collected for the microcrystalline powder. The material, crystallizing in the orthorhombic space group Iba2, is composed of a one-dimensional organic-inorganic hybrid polymer, ∞(1)[WO3(2,2'-bpy)], topologically identical to that found in the previously reported anhydrous phases [MO3(2,2'-bpy)] (M = Mo, W). While in the latter the N,N'-chelated 2,2'-bpy ligands of adjacent corner-shared {MO4N2} octahedra are positioned on the same side of the 1D chain, in 1 the 2,2'-bpy ligands alternate above and below the chain. The catalytic behavior of compound 1 for the epoxidation of cis-cyclooctene was compared with that for several other tungsten- or molybdenum-based (pre)catalysts, including the hybrid polymer [MoO3(2,2'-bpy)]. While the latter exhibits superior performance when tert-butyl hydroperoxide (TBHP) is used as the oxidant, compound 1 is superior when aqueous hydrogen peroxide is used, allowing near-quantitative conversion of the olefin to the epoxide. With H2O2, compounds 1 and [MoO3(2,2'-bpy)] act as sources of soluble active species, namely, the oxodiperoxo complex [MO(O2)2(2,2'-bpy)], which is formed in situ. Compounds 1 and [WO(O2)2(2,2'-bpy)] (2) were further tested in the epoxidation of cyclododecene, trans-2-octene, 1-octene, (R)-limonene, and styrene. The structure of 2 was determined by single-crystal X-ray diffraction and found to be isotypical with the molybdenum analogue.

Development and pilot line production of lithium doped silicon solar cells

NASA Technical Reports Server (NTRS)

Payne, P. A.

1972-01-01

The work performed over the period of September 1971 to August 1972 to develop production processes for fabrication of lithium doped P/N cells is described. The BCl3 diffusion without 02 was selected as the optimum diffusion process for fabrication of lithium doped cells. An 8-2-7 (warm up - deposition - drive-in time in minutes) diffusion schedule at 1055 C was used for the first two lots (300 cells each) delivered to JPL. Cell efficiencies ranged from 11.0 to 13.7% based on an AMO of 135.3 mW/sq cm. These high efficiencies were obtained using from 10 to 40 cells per boron diffusion; increasing the quantity beyond 40 resulted in lower outputs. At this point, the emphasis was placed on investigation of a BCl3 with 02 diffusion. Through evaluation of the effects of diffusion time and temperature, gas flow rates, and desposition plus drive-in vs. continuous deposition and no drive-in cycles, diffusion parameters were determined which produced short circuit currents of 136 + or - 4 mA for ten cells spaced along 12 in. of the diffusion boat. The quantity was increased to 60, 100, and 150 cell diffusions with no more variation in cell short circuit current than observed with 10 cells.

Ammonia losses and nitrogen partitioning at a southern High Plains open lot dairy

NASA Astrophysics Data System (ADS)

Todd, Richard W.; Cole, N. Andy; Hagevoort, G. Robert; Casey, Kenneth D.; Auvermann, Brent W.

2015-06-01

Animal agriculture is a significant source of ammonia (NH3). Cattle excrete most ingested nitrogen (N); most urinary N is converted to NH3, volatilized and lost to the atmosphere. Open lot dairies on the southern High Plains are a growing industry and face environmental challenges as well as reporting requirements for NH3 emissions. We quantified NH3 emissions from the open lot and wastewater lagoons of a commercial New Mexico dairy during a nine-day summer campaign. The 3500-cow dairy consisted of open lot, manure-surfaced corrals (22.5 ha area). Lactating cows comprised 80% of the herd. A flush system using recycled wastewater intermittently removed manure from feeding alleys to three lagoons (1.8 ha area). Open path lasers measured atmospheric NH3 concentration, sonic anemometers characterized turbulence, and inverse dispersion analysis was used to quantify emissions. Ammonia fluxes (15-min) averaged 56 and 37 μg m-2 s-1 at the open lot and lagoons, respectively. Ammonia emission rate averaged 1061 kg d-1 at the open lot and 59 kg d-1 at the lagoons; 95% of NH3 was emitted from the open lot. The per capita emission rate of NH3 was 304 g cow-1 d-1 from the open lot (41% of N intake) and 17 g cow-1 d-1 from lagoons (2% of N intake). Daily N input at the dairy was 2139 kg d-1, with 43, 36, 19 and 2% of the N partitioned to NH3 emission, manure/lagoons, milk, and cows, respectively.

How Does the Ionic Liquid Organizational Landscape Change when Nonpolar Cationic Alkyl Groups Are Replaced by Polar Isoelectronic Diethers?

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kashyap, Hemant K.; Santos, Cherry S.; Daly, Ryan P.

2012-12-21

The X-ray scattering experiments and molecular dynamics simulations have been performed to investigate the structure of four room temperature ionic liquids (ILs) comprising the bis(trifluoromethylsulfonyl)amide (NTf 2 –) anion paired with the triethyloctylammonium (N 2228 +) and triethyloctylphosphonium (P 2228 +) cations and their isoelectronic diether analogs, the (2-ethoxyethoxy)ethyltriethylammonium (N 222(2O2O2) +) and (2-ethoxyethoxy)ethyltriethylphosphonium (P 222(2O2O2) +) cations. Agreement between simulations and experiments is good and permits a clear interpretation of the important topological differences between these systems. The first sharp diffraction peak (or prepeak) in the structure function S(q) that is present in the case of the liquids containingmore » the alkyl-substituted cations is absent in the case of the diether substituted analogs. Using different theoretical partitioning schemes for the X-ray structure function, we show that the prepeak present in the alkyl-substituted ILs arises from polarity alternations between charged groups and nonpolar alkyl tails. In the case of the diether substituted ILs, we find considerable curling of tails. Anions can be found with high probability in two different environments: close to the cationic nitrogen (phosphorus) and also close to the two ether groups. Moreover, for the two diether systems, anions are found in locations from which they are excluded in the alkyl-substituted systems. This removes the longer range (polar/nonpolar) pattern of alternation that gives rise to the prepeak in alkyl-substituted systems.« less

2-(4-Meth-oxy-phen-yl)-1-pentyl-4,5-di-phenyl-1H-imidazole.

PubMed

Simpson, Jim; Mohamed, Shaaban K; Marzouk, Adel A; Talybov, Avtandil H; Abdelhamid, Antar A

2013-01-01

The title compound, C27H28N2O, is a lophine (2,4,5-triphenyl-1H-imidazole) derivative with an n-pentyl chain on the amine N atom and a 4-meth-oxy substituent on the benzene ring. The two phenyl and meth-oxy-benzene rings are inclined to the imidazole ring at angles of 25.32 (7), 76.79 (5) and 35.42 (7)°, respectively, while the meth-oxy substituent lies close to the plane of its benzene ring, with a maximum deviation of 0.126 (3) Å for the meth-oxy C atom. In the crystal, inversion dimers linked by pairs of C-H⋯O hydrogen bonds generate R2(2)(22) loops. These dimers are stacked along the a-axis direction.

Alternate methods of applying diffusants to silicon solar cells. [screen printing of thick-film paste materials and vapor phase transport from solid sources

NASA Technical Reports Server (NTRS)

Brock, T. W.; Field, M. B.

1979-01-01

Low-melting phosphate and borate glasses were screen printed on silicon wafers and heated to form n and p junctions. Data on surface appearance, sheet resistance and junction depth are presented. Similar data are reported for vapor phase transport from sintered aluminum metaphosphate and boron-containing glass-ceramic solid sources. Simultaneous diffusion of an N(+) layer with screen-printed glass and a p(+) layer with screen-printed Al alloy paste was attempted. No p(+) back surface field formation was achieved. Some good cells were produced but the heating in an endless-belt furnace caused a large scatter in sheet resistance and junction depth for three separate lots of wafers.

Greenhouse gas emissions from dairy open lot and manure stockpile in northern China: A case study.

PubMed

Ding, Luyu; Lu, Qikun; Xie, Lina; Liu, Jie; Cao, Wei; Shi, Zhengxiang; Li, Baoming; Wang, Chaoyuan; Zhang, Guoqiang; Ren, Shixi

2016-03-01

The open lots and manure stockpiles of dairy farm are major sources of greenhouse gas (GHG) emissions in typical dairy cow housing and manure management system in China. GHG (CO(2), CH(4) and N(2)O) emissions from the ground level of brick-paved open lots and uncovered manure stockpiles were estimated according to the field measurements of a typical dairy farm in Beijing by closed chambers in four consecutive seasons. Location variation and manure removal strategy impacts were assessed on GHG emissions from the open lots. Estimated CO(2), CH(4) and N(2)O emissions from the ground level of the open lots were 137.5±64.7 kg hd(-1) yr(-1), 0.45±0.21 kg hd(-1) yr(-1) and 0.13±0.08 kg hd(-1) yr(-1), respectively. There were remarkable location variations of GHG emissions from different zones (cubicle zone vs. aisle zone) of the open lot. However, the emissions from the whole open lot were less affected by the locations. After manure removal, lower CH(4) but higher N(2)O emitted from the open lot. Estimated CO(2), CH(4) and N(2)O emissions from stockpile with a stacking height of 55±12 cm were 858.9±375.8 kg hd(-1) yr(-1), 8.5±5.4 kg hd(-1) yr(-1) and 2.3±1.1 kg hd(-1) yr(-1), respectively. In situ storage duration, which estimated by manure volatile solid contents (VS), would affect GHG emissions from stockpiles. Much higher N(2)O was emitted from stockpiles in summer due to longer manure storage. This study deals with greenhouse gas (GHG) emissions from open lots and stockpiles. It's an increasing area of concern in some livestock producing countries. The Intergovernmental Panel on Climate Change (IPCC) methodology is commonly used for estimation of national GHG emission inventories. There is a shortage of on-farm information to evaluate the accuracy of these equations and default emission factors. This work provides valuable information for improving accounting practices within China or for similar manure management practice in other countries.

78 FR 51742 - Notice of Proposed Withdrawal and Opportunity for Public Meeting; California

Federal Register 2010, 2011, 2012, 2013, 2014

2013-08-21

..., inclusive, and SE\\1/ 4\\NE\\1/4\\; sec. 26, lots 11, 12, and 13, S\\1/2\\SE\\1/4\\NE\\1/4\\, and N\\1/ 2\\NE\\1/4\\SE\\1/4..., lots 13 to 16, inclusive, and 18 to 22, inclusive, and a portion of lot 8 as described in the Donation... platted. sec. 19, lots 11, 13, and 16 to 19, inclusive; sec. 20, lot 4; sec. 29, lots 7 and 11; sec. 32...

Prime Contract Awards Alphabetically by Contractor, by State or Country, and Place. Part 2. (American Nucleonics Corp.-Beachler Mark Associates)

DTIC Science & Technology

1989-01-01

Inn In -4 MOI -e4.~~3fm >U 6-z a ~ Wz ;w<<* -4.c 00)00 P.U~ 11.0U 22 02A4UZ z222 >Z 2222 02 * 00 U 0.-411)M)00 P. 0) U)n In C0U)M)004 0o RtO P 0)1a L o...z2 22222222zzz B 40 I W) 11 222 2 222 Z 222zz Z zzzzz2ZZZZ 11 1 Com 00n00 IV0) rto 04 l (0-4q O0 ()N04 0 ) I 0(0-4in0)-0000 B- >I woo B 11400) Rt...400o cc00. C X a vs I M-4 N X LU 4 0ULI L.. I.L. g,-4N-41U’I 4 N x 0U 5 cc N .40-4 N 2NGO(0 U-4 <-4 0)4 k ~N00004 (1 X wo Cci *00 IT4000 If .0 I 0-4

75 FR 50947 - Proposed Amendment of Class E Airspace; Kokomo, IN

Federal Register 2010, 2011, 2012, 2013, 2014

2010-08-18

... Logansport/Cass County Airport and Peru Municipal Airport also would be made in accordance with the FAA's...'32'' W.) Peru, Grissom Air Reserve Base, IN (Lat. 40[deg]38'53'' N., long. 86[deg]09'08'' W.) Grissom..., Logansport/Cass County Airport, IN (Lat. 40[deg]42'41'' N., long. 86[deg]22'22'' W.) Peru, Peru Municipal...

Recovery Act Home

Science.gov Websites

LAYING PAVEMENT Kirtland Air Force Base, N.M. - Workers lay new pavement to repair a parking lot . Slideshow 1 Slideshow 2 Kirtland Air Force Base, N.M. - Workers lay new pavement to repair a parking lot

Alpha List of Prime Contract Awards. Oct 91 - Sep 92. FY 92 (Federal Environmental Services - General Hospital Corporation)

DTIC Science & Technology

1993-01-01

4 I COON 4 X- IN IM COO 44 It~ LILA 55 ’)ýl LL - L W I -LLW - UUU-ýý .ý -UL..-- gL lA -40-U- (t’- 0-4-4 N CLIII S O0 I40 0x c> 4Nof-4-.) 05 CI OO 444...000 0- OC C CO C : 1 0-4-4 If 33 33:7 t3::t ;r333333:333r 333 3333: :r --3l3c c 3 c 33 3 :3 ofw 4. I000) i5 55 0 00) it so uC) 11 MM o 00...2Zzzzzz22zzzz2z22Zzzzzzzzzzzzzzz2222 z222zzzz 2 if 1C.)0-4 11 22zzmZZZZZZZZzzzz2zzzz2zz2zzzz~zzzzzzzzz2zz Z 55 C-4(10 II NN N NmJN N N N N :5 -4 1 CO-4NO 51 5 IO W-4NCO 19 it CO-4NCO

Effect of Sampling Plans on the Risk of Escherichia coli O157 Illness.

PubMed

Kiermeier, Andreas; Sumner, John; Jenson, Ian

2015-07-01

Australia exports about 150,000 to 200,000 tons of manufacturing beef to the United States annually. Each lot is tested for Escherichia coli O157 using the N-60 sampling protocol, where 60 small pieces of surface meat from each lot of production are tested. A risk assessment of E. coli O157 illness from the consumption of hamburgers made from Australian manufacturing meat formed the basis to evaluate the effect of sample size and amount on the number of illnesses predicted. The sampling plans evaluated included no sampling (resulting in an estimated 55.2 illnesses per annum), the current N-60 plan (50.2 illnesses), N-90 (49.6 illnesses), N-120 (48.4 illnesses), and a more stringent N-60 sampling plan taking five 25-g samples from each of 12 cartons (47.4 illnesses per annum). While sampling may detect some highly contaminated lots, it does not guarantee that all such lots are removed from commerce. It is concluded that increasing the sample size or sample amount from the current N-60 plan would have a very small public health effect.

28 CFR 22.22 - Revelation of identifiable data.

Code of Federal Regulations, 2011 CFR

2011-07-01

... STATISTICAL INFORMATION § 22.22 Revelation of identifiable data. (a) Except as noted in paragraph (b) of this section, research and statistical information relating to a private person may be revealed in identifiable... Act. (3) Persons or organizations for research or statistical purposes. Information may only be...

28 CFR 22.22 - Revelation of identifiable data.

Code of Federal Regulations, 2010 CFR

2010-07-01

... STATISTICAL INFORMATION § 22.22 Revelation of identifiable data. (a) Except as noted in paragraph (b) of this section, research and statistical information relating to a private person may be revealed in identifiable... sections 223(a)(12)(A), 223(a)(13), 223(a)(14), and 243 of the Juvenile Justice and Delinquency Prevention...

Growth kinetics and mass transport mechanisms of GaN columns by selective area metal organic vapor phase epitaxy

NASA Astrophysics Data System (ADS)

Wang, Xue; Hartmann, Jana; Mandl, Martin; Sadat Mohajerani, Matin; Wehmann, Hergo-H.; Strassburg, Martin; Waag, Andreas

2014-04-01

Three-dimensional GaN columns recently have attracted a lot of attention as the potential basis for core-shell light emitting diodes for future solid state lighting. In this study, the fundamental insights into growth kinetics and mass transport mechanisms of N-polar GaN columns during selective area metal organic vapor phase epitaxy on patterned SiOx/sapphire templates are systematically investigated using various pitch of apertures, growth time, and silane flow. Species impingement fluxes on the top surface of columns Jtop and on their sidewall Jsw, as well as, the diffusion flux from the substrate Jsub contribute to the growth of the GaN columns. The vertical and lateral growth rates devoted by Jtop, Jsw and Jsub are estimated quantitatively. The diffusion length of species on the SiOx mask surface λsub as well as on the sidewall surfaces of the 3D columns λsw are determined. The influences of silane on the growth kinetics are discussed. A growth model is developed for this selective area metal organic vapor phase epitaxy processing.

BLISS: A Computer Program for the Protection of Blood Donors

DTIC Science & Technology

1982-06-28

EXAMPLE 5 LIST OUTPUT -OC: I L. SECU F I T NO.: 111-11-1111 NAME: ALFRED RENTA NO. OF DONATIONS: 4 VDISK; 1 DONATION NO. : 1 DATE: 81-13-81 METHOD OF...DISK # I N-.’ SOCIAL SECURITY NO.: 111-11-1111 NAME: ALFRED RENTA .,, DONATION DATE: 04-23-81 -p SOCIAL SECURITY NO.: 222-22-2222 NAME: MILO BENDER

Role of diffusion-weighted MRI in differentiation of hepatic abscesses from non-infected fluid collections.

PubMed

Schmid-Tannwald, C; Schmid-Tannwald, C M; Morelli, J N; Neumann, R; Reiser, M F; Nikolaou, K; Rist, C

2014-07-01

To evaluate the role of diffusion-weighted magnetic resonance imaging (DW-MRI) in the differentiation of hepatic abscesses from non-infected fluid collections. In this retrospective study, 22 hepatic abscesses and 27 non-infected hepatic fluid collections were examined in 27 patients who underwent abdominal MRI including DW-MRI. Two independent observers reviewed T2-weighted + DW-MRI and T2-weighted + contrast-enhanced T1-weighted (CET1W) images in two sessions. Detection rates and confidence levels were calculated and compared using McNemar's and Wilcoxon's signed rank tests, respectively. Apparent diffusion coefficient (ADC) values of abscesses and non-infected fluid collections were compared using the t-test. Receiver operating characteristic (ROC) curves were constructed. There was no statistically significant difference in the accuracy of detecting abscesses using T2-weighted + DW-MRI (both observers: 21/22, 95.5%) versus T2-weighted + CET1W images (observer 1: 21/22, 95.5%; observer 2: 22/22, 100%; p < 0.01). Mean ADC values were significantly lower with abscesses versus non-infected fluid collections (0.83 ± 0.24 versus 2.25 ± 0.61 × 10(-3) mm(2)/s; p < 0.001). With ROC analysis there was good discrimination of abscess from non-infected fluid collections at a threshold ADC value of 1.36 × 10(-3) mm(2)/s. DW-MRI allows qualitative and quantitative differentiation of abscesses from non-infected fluid collections in the liver. Copyright © 2014 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

Ether bond effects in quaternary ammonium and phosphonium ionic liquid-propanol solutions

NASA Astrophysics Data System (ADS)

Kishimura, Hiroaki; Kohki, Erica; Nakada, Ayumu; Tamatani, Kentaro; Abe, Hiroshi

2018-03-01

The liquid-liquid equilibria (LLE) of quaternary ammonium and phosphonium ionic liquid (IL)-propanol solutions were examined. The ILs contained cations with or without ether bonds; the anion in all the ILs was bis(trifluoromethanesulfonyl)imide (TFSI-). The cations without ether groups are tributylmethyl ammonium (N4441+), triethylpentyl phosphonium (P2225+), triethyloctyl phosphonium (P2228+), and tributylmethyl phosphonium (P4441+). The cations containing ether groups are N,N-diethyl-N-methyl-N-(2-methoxyethyl) ammonium, (N122(2O1)+), triethyl(methoxymethyl) phosphonium (P222(1O1)+), and triethyl(2-methoxyethyl) phosphonium, (P222(2O1)+). Propanol isomer effect was observed to affect the LLEs, reflecting the geometrical factors and hydrophobicities of 1-propanol and 2-propanol. According to Raman spectroscopy, the TFSI- anion conformers in the mixtures were altered in the presence of ether bonds in the cations. The universal quasichemical (UNIQUAC) interaction parameters are consistent with significant factors affecting IL-propanol solutions, such as the type of cation (ammonium or phosphonium), ether bonds, TFSI- conformers, and propanol isomer effects.

Onyx versus nBCA and coils in the treatment of intracranial dural arteriovenous fistulas

PubMed Central

Choo, Douglas M

2016-01-01

Background and purpose Intracranial dural arteriovenous fistulas (DAVFs) with cortical venous drainage have significant morbidity and mortality. Complete closure of these lesions is necessary to reduce these risks. The purpose of our study was to compare the outcome of DAVFs treated with Onyx versus those treated with n-Butyl Cyanoacrylate (nBCA) and coil embolization in a case-control study. Compared with nBCA and coil embolization, we hypothesized that Onyx embolization for DAVF is safer and has a higher chance of complete obliteration, with no need for post-embolization surgery for the DAVF. Materials and methods From 1998 to 2015, 29 patients who had DAVFs were treated with endovascular embolization. Of these, 24 patients had imaging available for analysis. Successful closure rates, complications, and procedure time were compared between the embolization techniques. Results The chance of not requiring post-embolization surgery with Onyx (81.8%) was significantly higher (p = 0.005) than with nBCA (22.22%). The complication rate with Onyx (9.1%) tended to be lower compared with that of nBCA (22.22%; p = 0.37). Procedural time was not significantly different between Onyx (mean 267 minutes) and nBCA (mean 288 minutes) (p = 0.59). The odds ratio of a DAVF being treated with Onyx and then requiring no follow-up surgery was 17.5 (95% CI 1.97–155.4). Conclusion Our case-control study suggests that Onyx embolization is superior to nBCA and coil embolization in completely obliterating DAVFs, with higher odds of no post-embolization surgery. We also found that Onyx is safe for embolization of DAVFs, with no associated neurological mortality and morbidity. PMID:26748082

Onyx versus nBCA and coils in the treatment of intracranial dural arteriovenous fistulas.

PubMed

Choo, Douglas M; Shankar, Jai Jai Shiva

2016-04-01

Intracranial dural arteriovenous fistulas (DAVFs) with cortical venous drainage have significant morbidity and mortality. Complete closure of these lesions is necessary to reduce these risks. The purpose of our study was to compare the outcome of DAVFs treated with Onyx versus those treated with n-Butyl Cyanoacrylate (nBCA) and coil embolization in a case-control study. Compared with nBCA and coil embolization, we hypothesized that Onyx embolization for DAVF is safer and has a higher chance of complete obliteration, with no need for post-embolization surgery for the DAVF. From 1998 to 2015, 29 patients who had DAVFs were treated with endovascular embolization. Of these, 24 patients had imaging available for analysis. Successful closure rates, complications, and procedure time were compared between the embolization techniques. The chance of not requiring post-embolization surgery with Onyx (81.8%) was significantly higher (p = 0.005) than with nBCA (22.22%). The complication rate with Onyx (9.1%) tended to be lower compared with that of nBCA (22.22%; p = 0.37). Procedural time was not significantly different between Onyx (mean 267 minutes) and nBCA (mean 288 minutes) (p = 0.59). The odds ratio of a DAVF being treated with Onyx and then requiring no follow-up surgery was 17.5 (95% CI 1.97-155.4). Our case-control study suggests that Onyx embolization is superior to nBCA and coil embolization in completely obliterating DAVFs, with higher odds of no post-embolization surgery. We also found that Onyx is safe for embolization of DAVFs, with no associated neurological mortality and morbidity. © The Author(s) 2016.

Students creative thinking skills in solving two dimensional arithmetic series through research-based learning

NASA Astrophysics Data System (ADS)

Tohir, M.; Abidin, Z.; Dafik; Hobri

2018-04-01

Arithmetics is one of the topics in Mathematics, which deals with logic and detailed process upon generalizing formula. Creativity and flexibility are needed in generalizing formula of arithmetics series. This research aimed at analyzing students creative thinking skills in generalizing arithmetic series. The triangulation method and research-based learning was used in this research. The subjects were students of the Master Program of Mathematics Education in Faculty of Teacher Training and Education at Jember University. The data was collected by giving assignments to the students. The data collection was done by giving open problem-solving task and documentation study to the students to arrange generalization pattern based on the dependent function formula i and the function depend on i and j. Then, the students finished the next problem-solving task to construct arithmetic generalization patterns based on the function formula which depends on i and i + n and the sum formula of functions dependent on i and j of the arithmetic compiled. The data analysis techniques operative in this study was Miles and Huberman analysis model. Based on the result of data analysis on task 1, the levels of students creative thinking skill were classified as follows; 22,22% of the students categorized as “not creative” 38.89% of the students categorized as “less creative” category; 22.22% of the students categorized as “sufficiently creative” and 16.67% of the students categorized as “creative”. By contrast, the results of data analysis on task 2 found that the levels of students creative thinking skills were classified as follows; 22.22% of the students categorized as “sufficiently creative”, 44.44% of the students categorized as “creative” and 33.33% of the students categorized as “very creative”. This analysis result can set the basis for teaching references and actualizing a better teaching model in order to increase students creative thinking skills.

Development and Applications of Laminar Optical Tomography for In Vivo Imaging

NASA Astrophysics Data System (ADS)

Burgess, Sean A.

Laminar optical tomography (LOT) is an optical imaging technique capable of making depth-resolved measurements of absorption and fluorescence contrast in scattering tissue. LOT was first demonstrated in 2004 by Hillman et al [1]. The technique combines a non-contact laser scanning geometry, similar to a low magnification confocal microscope, with the imaging principles of diffuse optical tomography (DOT). This thesis describes the development and application of a second generation LOT system, which acquires both fluorescence and multi-wavelength measurements simultaneously and is better suited for in vivo measurements. Chapter 1 begins by reviewing the interactions of light with tissue that form the foundation of optical imaging. A range of related optical imaging techniques and the basic principles of LOT imaging are then described. In Chapter 2, the development of the new LOT imaging system is described including the implementation of a series of interfaces to allow clinical imaging. System performance is then evaluated on a range of imaging phantoms. Chapter 3 describes two in vivo imaging applications explored using the second generation LOT system, first in a clinical setting where skin lesions were imaged, and then in a laboratory setting where LOT imaging was performed on exposed rat cortex. The final chapter provides a brief summary and describes future directions for LOT. LOT has the potential to find applications in medical diagnostics, surgical guidance, and in-situ monitoring owing to its sensitivity to absorption and fluorescence contrast as well as its ability to provide depth sensitive measures. Optical techniques can characterize blood volume and oxygenation, two important biological parameters, through measurements at different wavelengths. Fluorescence measurements, either from autofluorescence or fluorescent dyes, have shown promise for identifying and analyzing lesions in various epithelial tissues including skin [2, 3], colon [4], esophagus [5, 6], oral mucosa [7, 8], and cervix [9]. The desire to capture these types of measurements with LOT motivated much of the work presented here.

Crystal structure of 5-{4'-[(2-{2-[2-(2-ammonio-eth-oxy)eth-oxy]eth-oxy}eth-yl)carbamo-yl]-4-meth-oxy-[1,1'-biphen-yl]-3-yl}-3-oxo-1,2,5-thia-diazo-lidin-2-ide 1,1-dioxide: a potential inhibitor of the enzyme protein tyrosine phosphatase 1B (PTP1B).

PubMed

Ruddraraju, Kasi Viswanatharaju; Hillebrand, Roman; Barnes, Charles L; Gates, Kent S

2015-04-01

The title compound, C24H32N4O8S, (I), crystallizes as a zwitterion. The terminal amine N atom of the [(2-{2-[2-(2-ammonio-eth-oxy)eth-oxy]eth-oxy}eth-yl)carbamo-yl] side chain is protonated, while the 1,2,5-thia-diazo-lidin-3-one 1,1-dioxide N atom is deprotonated. The side chain is turned over on itself with an intra-molecular N-H⋯O hydrogen bond. The 1,2,5-thia-diazo-lidin-3-one 1,1-dioxide ring has an envelope conformation with the aryl-substituted N atom as the flap. Its mean plane is inclined by 62.87 (8)° to the aryl ring to which it is attached, while the aryl rings of the biphenyl unit are inclined to one another by 20.81 (8)°. In the crystal, mol-ecules are linked by N-H⋯O and N-H⋯N hydrogen bonds, forming slabs lying parallel to (010). Within the slabs there are C-H⋯O and C-H⋯N hydrogen bonds and C-H⋯π inter-actions present.

40 CFR 85.2222 - On-board diagnostic test procedures.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 19 2013-07-01 2013-07-01 false On-board diagnostic test procedures... Warranty Short Tests § 85.2222 On-board diagnostic test procedures. The test sequence for the inspection of on-board diagnostic systems on 1996 and newer light-duty vehicles and light-duty trucks shall consist...

40 CFR 85.2222 - On-board diagnostic test procedures.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 19 2012-07-01 2012-07-01 false On-board diagnostic test procedures... Warranty Short Tests § 85.2222 On-board diagnostic test procedures. The test sequence for the inspection of on-board diagnostic systems on 1996 and newer light-duty vehicles and light-duty trucks shall consist...

40 CFR 85.2222 - On-board diagnostic test procedures.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 18 2011-07-01 2011-07-01 false On-board diagnostic test procedures... Warranty Short Tests § 85.2222 On-board diagnostic test procedures. The test sequence for the inspection of on-board diagnostic systems on 1996 and newer light-duty vehicles and light-duty trucks shall consist...

Modelisation de la diffusion sur les surfaces metalliques: De l'adatome aux processus de croissance

NASA Astrophysics Data System (ADS)

Boisvert, Ghyslain

Cette these est consacree a l'etude des processus de diffusion en surface dans le but ultime de comprendre, et de modeliser, la croissance d'une couche mince. L'importance de bien mai triser la croissance est primordiale compte tenu de son role dans la miniaturisation des circuits electroniques. Nous etudions ici les surface des metaux nobles et de ceux de la fin de la serie de transition. Dans un premier temps, nous nous interessons a la diffusion d'un simple adatome sur une surface metallique. Nous avons, entre autres, mis en evidence l'apparition d'une correlation entre evenements successifs lorsque la temperature est comparable a la barriere de diffusion, i.e., la diffusion ne peut pas etre associee a une marche aleatoire. Nous proposons un modele phenomenologique simple qui reproduit bien les resultats des simulations. Ces calculs nous ont aussi permis de montrer que la diffusion obeit a la loi de Meyer-Neldel. Cette loi stipule que, pour un processus active, le prefacteur augmente exponentiellement avec la barriere. En plus, ce travail permet de clarifier l'origine physique de cette loi. En comparant les resultats dynamiques aux resultats statiques, on se rend compte que la barriere extraite des calculs dynamiques est essentiellement la meme que celle obtenue par une approche statique, beaucoup plus simple. On peut donc obtenir cette barriere a l'aide de methodes plus precises, i.e., ab initio, comme la theorie de la fonctionnelle de la densite, qui sont aussi malheureusement beaucoup plus lourdes. C'est ce que nous avons fait pour plusieurs systemes metalliques. Nos resultats avec cette derniere approche se comparent tres bien aux resultats experimentaux. Nous nous sommes attardes plus longuement a la surface (111) du platine. Cette surface regorge de particularites interessantes, comme la forme d'equilibre non-hexagonale des i lots et deux sites d'adsorption differents pour l'adatome. De plus, des calculs ab initio precedents n'ont pas reussi a confirmer la forme d'equilibre et surestiment grandement la barriere. Nos calculs, plus complets et dans un formalisme mieux adapte a ce genre de probleme, predisent correctement la forme d'equilibre, qui est en fait due a un relachement different du stress de surface aux deux types de marches qui forment les cotes des i lots. Notre valeur pour la barriere est aussi fortement diminuee lorsqu'on relaxe les forces sur les atomes de la surface, amenant le resultat theorique beaucoup plus pres de la valeur experimentale. Nos calculs pour le cuivre demontre en effet que la diffusion de petits i lots pendant la croissance ne peut pas etre negligee dans ce cas, mettant en doute la valeur des interpretations des mesures experimentales. (Abstract shortened by UMI.)

Six-Month Safety Data of Recombinant Vesicular Stomatitis Virus-Zaire Ebola Virus Envelope Glycoprotein Vaccine in a Phase 3 Double-Blind, Placebo-Controlled Randomized Study in Healthy Adults.

PubMed

Halperin, Scott A; Arribas, Jose R; Rupp, Richard; Andrews, Charles P; Chu, Laurence; Das, Rituparna; Simon, Jakub K; Onorato, Matthew T; Liu, Kenneth; Martin, Jason; Helmond, Frans A

2017-06-15

This study (NCT02503202) evaluated the safety of recombinant vesicular stomatitis virus-Zaire Ebola virus envelope glycoprotein vaccine (rVSVΔG-ZEBOV-GP). Overall, 1197 subjects were randomized 2:2:2:2:1; 1194 were vaccinated with 1 dose of 1 of 3 lots of rVSVΔG- ZEBOV-GP (2 × 107 plaque-forming units [pfu], n = 797; combined-lots group), a single high-dose lot of rVSVΔG-ZEBOV-GP (1 × 108 pfu, n = 264; high-dose group), or placebo (n = 133). Daily temperatures and adverse events (AEs) were recorded days 1 to 42 postvaccination. Solicited AEs included injection-site AEs from days 1 to 5, and joint pain, joint swelling, vesicular lesions (blisters), and rashes from days 1 to 42. Serious AEs (SAEs) were recorded through 6 months postvaccination. Fever (≥38.0°C) was observed in 20.2% of combined lots (3.2% with ≥39.0°C), 32.2% of high-dose (4.3% with ≥39.0°C), and 0.8% of placebo (0.8% with ≥39.0°C). Incidences of AEs of interest (days 1-42) were arthralgia (17.1% combined lots, 20.4% high-dose, 3.0% placebo), arthritis (5.1% combined lots, 4.2% high-dose, 0.0% placebo), and rash (3.8% combined lots, 3.8% high-dose, 1.5% placebo). Twenty-one SAEs and 2 deaths were reported, all assessed by investigators as unrelated to vaccine. rVSVΔG-ZEBOV-GP was generally well-tolerated, with increased rates of injection-site and systemic AEs compared to placebo, and no vaccine-related SAEs or deaths. These findings support the use of rVSVΔG-ZEBOV-GP vaccine in persons at risk for Ebola virus disease. NCT02503202. © The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.

Correlation of Particle-Induced Displacement Damage in Silicon

NASA Astrophysics Data System (ADS)

Summers, G. P.; Burke, E. A.; Dale, C. J.; Wolicki, E. A.; Marshall, P. W.; Gehlhausen, M. A.

1987-12-01

Correlation is made between the effects of displacement damage caused in several types of silicon bipolar transistors by protons, deuterons, helium ions, and by 1 MeV equivalent neutrons. These measurements are compared to calculations of the nonionizing energy deposition in silicon as a function of particle type and energy. Measurements were made of displacement damage factors for 2N2222A and 2N2907A switching transistors, and for 2N3055, 2N6678, and 2N6547 power transistors, as a function of collector current using 3.7 - 175 MeV protons, 4.3 - 37 MeV deuterons, and 16.8 - 65 MeV helium ions. Long term ionization effects on the value of the displacement damage factors were taken into account. In calculating the energy dependence of the nonionizing energy deposition, Rutherford, nuclear elastic, and nuclear inelastic interactions, and Lindhard energy partition were considered. The main conclusions of the work are as follows: 1) The ratio of the displacement damage factors for a given charged particle to the 1 MeV equivalent neutron damage factor, as a function of energy, falls on a common curve which is independent of collector current. 2) Deuterons of a given energy are about twice as damaging as protons and helium ions are about eighteen times as damaging as protons.

Development of Sintered Si3N4 for High Performance Thermomechanical Applications.

DTIC Science & Technology

1984-01-01

noted( 17) that final grain size of sintered Si3 N4 is quite sensitive to both temperature and time at temperature. The sintering of Si NI containing...Characterization of Ube-SN-E0 Si3 N4 Chemical Analysis Lot A-10 Lot A-18 N (alkali fusion) wt . % 38 38 0 (inert gas fusion) wt . % 1.2 1.4 C (inert gas fusion) wt ...temperature stutral applications except for the high creep rate, Which is of the ame order a NC-13. The sintering of -qfiN4ontaning 5 wt % LiAIq0 1and

Sublimation as a landform-shaping process on Pluto

NASA Astrophysics Data System (ADS)

Moore, Jeffrey M.; Howard, Alan D.; Umurhan, Orkan M.; White, Oliver L.; Schenk, Paul M.; Beyer, Ross A.; McKinnon, William B.; Spencer, John R.; Grundy, Will M.; Lauer, Tod R.; Nimmo, Francis; Young, Leslie A.; Stern, S. Alan; Weaver, Harold A.; Olkin, Cathy B.; Ennico, Kimberly; New Horizons Science Team

2017-05-01

Fields of pits, both large and small, in Tombaugh Regio (Sputnik Planitia, and the Pitted Uplands to the east), and along the scarp of Piri Rupes, are examples of landscapes on Pluto where we conclude that sublimation drives their formation and evolution. Our heuristic modeling closely mimics the form, spacing, and arrangement of a variety of Tombaugh Regio's pits. Pluto's sublimation modified landforms appear to require a significant role for (diffusive) mass wasting as suggested by our modeling. In our models, the temporal evolution of pitted surfaces is such that initially lots of time passes with little happening, then eventually, very rapid development of relief and rapid sublimation. Small pits on Sputnik Planitia are consistent with their formation in N2-dominated materials. As N2-ice readily flows, some other ``stiffer'' volatile ice may play a role in supporting the relief of sublimation degraded landforms that exhibit several hundred meters of relief. A strong candidate is CH4, which is spectroscopically observed to be associated with these features, but the current state of rheological knowledge for CH4 ice at Pluto conditions is insufficient for a firm assessment.

Impact of industrial dry-milling on fumonisin redistribution in non-transgenic corn in Brazil.

PubMed

Bordini, Jaqueline Gozzi; Ono, Mario Augusto; Garcia, Glauco Tironi; Fazani, Victor Hugo Meconi; Vizoni, Édio; Rodrigues, Karem Caroline Bonacin; Hirooka, Elisa Yoko; Ono, Elisabete Yurie Sataque

2017-04-01

The aim of this study was to evaluate the fate of fumonisins B 1 (FB 1 ) and B 2 (FB 2 ) during industrial dry-milling in two lots from 2014 (n=120) and 2015 (n=120) of non-transgenic corn and their fractions (germ, pericarp, endosperm, cornmeal and grits), collected from one of the major Brazilian milling industries. Fumonisins were concentrated in the germ and pericarp at a rate of 322% and 188% (lot 1) and 311% and 263% (lot 2), respectively. In the endosperm, cornmeal and grits fumonisin levels decreased from 60 to 95%. Fumonisin levels in cornmeal and grits were below the maximum limit tolerated by the European Commission. Therefore, corn industrial dry-milling can contribute to reducing fumonisin levels in corn products intended for human consumption. Copyright © 2016 Elsevier Ltd. All rights reserved.

Monitoring health interventions – who's afraid of LQAS?

PubMed Central

Pezzoli, Lorenzo; Kim, Sung Hye

2013-01-01

Lot quality assurance sampling (LQAS) is used to evaluate health services. Subunits of a population (lots) are accepted or rejected according to the number of failures in a random sample (N) of a given lot. If failures are greater than decision value (d), we reject the lot and recommend corrective actions in the lot (i.e. intervention area); if they are equal to or less than d, we accept it. We used LQAS to monitor coverage during the last 3 days of a meningitis vaccination campaign in Niger. We selected one health area (lot) per day reporting the lowest administrative coverage in the previous 2 days. In the sampling plan we considered: N to be small enough to allow us to evaluate one lot per day, deciding to sample 16 individuals from the selected villages of each health area, using probability proportionate to population size; thresholds and d to vary according to administrative coverage reported; α ≤5% (meaning that, if we would have conducted the survey 100 times, we would have accepted the lot up to five times when real coverage was at an unacceptable level) and β ≤20% (meaning that we would have rejected the lot up to 20 times, when real coverage was equal or above the satisfactory level). We classified all three lots as with the acceptable coverage. LQAS appeared to be a rapid, simple, and statistically sound method for in-process coverage assessment. We encourage colleagues in the field to consider using LQAS in complement with other monitoring techniques such as house-to-house monitoring. PMID:24206650

Monitoring health interventions--who's afraid of LQAS?

PubMed

Pezzoli, Lorenzo; Kim, Sung Hye

2013-11-08

Lot quality assurance sampling (LQAS) is used to evaluate health services. Subunits of a population (lots) are accepted or rejected according to the number of failures in a random sample (N) of a given lot. If failures are greater than decision value (d), we reject the lot and recommend corrective actions in the lot (i.e. intervention area); if they are equal to or less than d, we accept it. We used LQAS to monitor coverage during the last 3 days of a meningitis vaccination campaign in Niger. We selected one health area (lot) per day reporting the lowest administrative coverage in the previous 2 days. In the sampling plan we considered: N to be small enough to allow us to evaluate one lot per day, deciding to sample 16 individuals from the selected villages of each health area, using probability proportionate to population size; thresholds and d to vary according to administrative coverage reported; α ≤5% (meaning that, if we would have conducted the survey 100 times, we would have accepted the lot up to five times when real coverage was at an unacceptable level) and β ≤20% (meaning that we would have rejected the lot up to 20 times, when real coverage was equal or above the satisfactory level). We classified all three lots as with the acceptable coverage. LQAS appeared to be a rapid, simple, and statistically sound method for in-process coverage assessment. We encourage colleagues in the field to consider using LQAS in complement with other monitoring techniques such as house-to-house monitoring.

2222 kidney transplantations at the University Hospital Basel: a story of success and new challenges.

PubMed

Wehmeier, Caroline; Georgalis, Argyrios; Hirt-Minkowski, Patricia; Amico, Patrizia; Hoenger, Gideon; Voegele, Thomas; Brun, Nicole; Bock, Andreas; Wolff, Thomas; Guerke, Lorenz; Bachmann, Alexander; Hopfer, Helmut; Dickenmann, Michael; Steiger, Jürg; Schaub, Stefan

2016-01-01

The aim was to investigate changes in kidney allograft donor/recipient characteristics and outcomes at our centre. We retrospectively reviewed all 2222 kidney transplantations performed between 1967 and 2015. The population was divided into four eras on the basis of time intervals corresponding to major changes in immunosuppression and pretransplant risk stratification: (i.) 1967-1980 (n = 231), (ii.) 1981-1997 (n = 883), (iii.) 1998-2004 (n = 437), (iv.) 2005-2015 (n = 671). In deceased donor transplants, we observed a continuous increase of the median recipient (45, 51, 56 and 58 years; p <0.0001) and donor (26, 36, 49 and 54 years; p <0.0001) age. Notably, the frequency of expanded criteria donors increased dramatically (1%, 10%, 28%, 40%, p <0.0001). Graft survival at 1 year (63%, 82%, 89%, 95%), 5 years (46%, 66%, 72%, 78%) and 10 years (27%, 46%, 48%, 61%) significantly improved (p <0.0001). Patient survival also significantly improved and remained stable at a high level within the last three eras (1 year: 97%; 5 years: 87%; 10 years: 71%). Similar trends along with slightly better outcomes were noticed in living donor transplantations. In the most recent era, graft losses in elderly patients were in 81% of cases related to the patient's death, whereas in young patients 83% of graft losses were caused by transplant failure (mainly rejection). Allograft function at the time of patients' deaths would have allowed for calculated 10 additional years with an estimated glomerular filtration rate >15 ml/min. Despite increasing donor and recipient age, outcomes improved, illustrating ongoing progress in kidney transplantation. A major new challenge is to match the functional capacity of the donor organ with the anticipated lifespan of the recipient.

HPV E6/E7 RNA in situ hybridization signal patterns as biomarkers of three-tier cervical intraepithelial neoplasia grade.

PubMed

Evans, Mark F; Peng, Zhihua; Clark, Kelli M; Adamson, Christine S-C; Ma, Xiao-Jun; Wu, Xingyong; Wang, Hongwei; Luo, Yuling; Cooper, Kumarasen

2014-01-01

Cervical lesion grading is critical for effective patient management. A three-tier classification (cervical intraepithelial neoplasia [CIN] grade 1, 2 or 3) based on H&E slide review is widely used. However, for reasons of considerable inter-observer variation in CIN grade assignment and for want of a biomarker validating a three-fold stratification, CAP-ASCCP LAST consensus guidelines recommend a two-tier system: low- or high-grade squamous intraepithelial lesions (LSIL or HSIL). In this study, high-risk HPV E6/E7 and p16 mRNA expression patterns in eighty-six CIN lesions were investigated by RNAscope chromogenic in situ hybridization (CISH). Specimens were also screened by immunohistochemistry for p16INK4a (clone E6H4), and by tyramide-based CISH for HPV DNA. HPV genotyping was performed by GP5+/6+ PCR combined with cycle-sequencing. Abundant high-risk HPV RNA CISH signals were detected in 26/32 (81.3%) CIN 1, 22/22 (100%) CIN 2 and in 32/32 (100%) CIN 3 lesions. CIN 1 staining patterns were typified (67.7% specimens) by abundant diffusely staining nuclei in the upper epithelial layers; CIN 2 lesions mostly (66.7%) showed a combination of superficial diffuse-stained nuclei and multiple dot-like nuclear and cytoplasmic signals throughout the epithelium; CIN 3 lesions were characterized (87.5%) by multiple dot-like nuclear and cytoplasmic signals throughout the epithelial thickness and absence/scarcity of diffusely staining nuclei (trend across CIN grades: P<0.0001). These data are consistent with productive phase HPV infections exemplifying CIN 1, transformative phase infections CIN 3, whereas CIN 2 shows both productive and transformative phase elements. Three-tier data correlation was not found for the other assays examined. The dual discernment of diffuse and/or dot-like signals together with the assay's high sensitivity for HPV support the use of HPV E6/E7 RNA CISH as an adjunct test for deciding lesion grade when CIN 2 grading may be beneficial (e.g. among young women) or when 'LSIL vs. HSIL' assignment is equivocal.

HPV E6/E7 RNA In Situ Hybridization Signal Patterns as Biomarkers of Three-Tier Cervical Intraepithelial Neoplasia Grade

PubMed Central

Evans, Mark F.; Peng, Zhihua; Clark, Kelli M.; Adamson, Christine S.-C.; Ma, Xiao-Jun; Wu, Xingyong; Wang, Hongwei; Luo, Yuling; Cooper, Kumarasen

2014-01-01

Cervical lesion grading is critical for effective patient management. A three-tier classification (cervical intraepithelial neoplasia [CIN] grade 1, 2 or 3) based on H&E slide review is widely used. However, for reasons of considerable inter-observer variation in CIN grade assignment and for want of a biomarker validating a three-fold stratification, CAP-ASCCP LAST consensus guidelines recommend a two-tier system: low- or high-grade squamous intraepithelial lesions (LSIL or HSIL). In this study, high-risk HPV E6/E7 and p16 mRNA expression patterns in eighty-six CIN lesions were investigated by RNAscope chromogenic in situ hybridization (CISH). Specimens were also screened by immunohistochemistry for p16INK4a (clone E6H4), and by tyramide-based CISH for HPV DNA. HPV genotyping was performed by GP5+/6+ PCR combined with cycle-sequencing. Abundant high-risk HPV RNA CISH signals were detected in 26/32 (81.3%) CIN 1, 22/22 (100%) CIN 2 and in 32/32 (100%) CIN 3 lesions. CIN 1 staining patterns were typified (67.7% specimens) by abundant diffusely staining nuclei in the upper epithelial layers; CIN 2 lesions mostly (66.7%) showed a combination of superficial diffuse-stained nuclei and multiple dot-like nuclear and cytoplasmic signals throughout the epithelium; CIN 3 lesions were characterized (87.5%) by multiple dot-like nuclear and cytoplasmic signals throughout the epithelial thickness and absence/scarcity of diffusely staining nuclei (trend across CIN grades: P<0.0001). These data are consistent with productive phase HPV infections exemplifying CIN 1, transformative phase infections CIN 3, whereas CIN 2 shows both productive and transformative phase elements. Three-tier data correlation was not found for the other assays examined. The dual discernment of diffuse and/or dot-like signals together with the assay’s high sensitivity for HPV support the use of HPV E6/E7 RNA CISH as an adjunct test for deciding lesion grade when CIN 2 grading may be beneficial (e.g. among young women) or when ‘LSIL vs. HSIL’ assignment is equivocal. PMID:24625757

Urgent consultations at the dermatology department of Basel University Hospital, Switzerland: characterisation of patients and setting - a 12-month study with 2,222 patients data and review of the literature.

PubMed

Ruzza, N; Itin, P H; Beltraminelli, H

2014-01-01

Urgent consultations for skin disorders are commonly done in different settings. Scarce data exist about the characteristics of these patients. The aim of this study was to analyse specific characteristics of patients receiving an urgent consultation at a dermatology department in a university hospital. We prospectively recorded the data of all patients having had an urgent consultation during a period of 12 months. We registered 2,222 urgent consultations. The most frequent diagnoses were eczemas (24.8%), dermatomycoses (5.1%) and dermatitis not otherwise specified (4.8%). The most frequent treatments were topical steroids, emollients, topical antibiotics, systemic antihistamines, antibiotics and virostatics. 2.2% of patients were hospitalized, 78.8% asked for a consultation for a disease lasting less than 4 weeks, and 6.9% presented the same day as the skin disease appeared. This study shows the characteristics of patients receiving an urgent dermatologic consultation. It underlines the need for collaboration between dermatologists, other physicians, general practitioners and nurses. © 2014 S. Karger AG, Basel.

Effects of a malfunctional column on conventional and FeedCol-simulated moving bed chromatography performance.

PubMed

Song, Ji-Yeon; Oh, Donghoon; Lee, Chang-Ha

2015-07-17

The effects of a malfunctional column on the performance of a simulated moving bed (SMB) process were studied experimentally and theoretically. The experimental results of conventional four-zone SMB (2-2-2-2 configuration) and FeedCol operation (2-2-2-2 configuration with one feed column) with one malfunctional column were compared with simulation results of the corresponding SMB processes with a normal column configuration. The malfunctional column in SMB processes significantly deteriorated raffinate purity. However, the extract purity was equivalent or slightly improved compared with the corresponding normal SMB operation because the complete separation zone of the malfunctional column moved to a lower flow rate range in zones II and III. With the malfunctional column configuration, FeedCol operation gave better experimental performance (up to 7%) than conventional SMB operation because controlling product purity with FeedCol operation was more flexible through the use of two additional operating variables, injection time and injection length. Thus, compared with conventional SMB separation, extract with equivalent or slightly better purity could be produced from FeedCol operation even with a malfunctional column, while minimizing the decrease in raffinate purity (less than 2%). Copyright © 2015 Elsevier B.V. All rights reserved.

34 CFR 222.2 - What definitions apply to this part?

Code of Federal Regulations, 2012 CFR

2012-07-01

... percentage Low-rent housing School facilities (2) The following term defined in § 222.30 applies to this part..., but who are attending schools other than those operated by the applicant under a tuition arrangement... include children who— (i) Have never attended classes in schools of the LEA or of another educational...

34 CFR 222.2 - What definitions apply to this part?

Code of Federal Regulations, 2014 CFR

2014-07-01

... percentage Low-rent housing School facilities (2) The following term defined in § 222.30 applies to this part..., but who are attending schools other than those operated by the applicant under a tuition arrangement... include children who— (i) Have never attended classes in schools of the LEA or of another educational...

34 CFR 222.2 - What definitions apply to this part?

Code of Federal Regulations, 2013 CFR

2013-07-01

... percentage Low-rent housing School facilities (2) The following term defined in § 222.30 applies to this part..., but who are attending schools other than those operated by the applicant under a tuition arrangement... include children who— (i) Have never attended classes in schools of the LEA or of another educational...

20 CFR 222.2 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-04-01

... this chapter. Final divorce means a divorce that completely dissolves a marriage and restores the parties to the status of single persons; it is also referred to as an absolute divorce. Finally divorced person means a person whose marriage has been terminated or dissolved by a final divorce. Legal...

20 CFR 222.2 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-04-01

... this chapter. Final divorce means a divorce that completely dissolves a marriage and restores the parties to the status of single persons; it is also referred to as an absolute divorce. Finally divorced person means a person whose marriage has been terminated or dissolved by a final divorce. Legal...

20 CFR 222.2 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-04-01

... this chapter. Final divorce means a divorce that completely dissolves a marriage and restores the parties to the status of single persons; it is also referred to as an absolute divorce. Finally divorced person means a person whose marriage has been terminated or dissolved by a final divorce. Legal...

20 CFR 222.2 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-04-01

... this chapter. Final divorce means a divorce that completely dissolves a marriage and restores the parties to the status of single persons; it is also referred to as an absolute divorce. Finally divorced person means a person whose marriage has been terminated or dissolved by a final divorce. Legal...

Mechanical Properties of Aerojet, Thiokol, and JA2 High-Energy Gun Propellants at 1.5 m/s Deformation Rate

DTIC Science & Technology

2002-01-01

a2 6 n -32 4C La /C A> i c 4S Figure 5. Remains of specimens tested at 210, 630, and -32 0C. 5 I AUg 2001 "-1t AERQJET/"THIDKOL LOTS 0111W PM 4-40.00...10.00 +78.00 STRESS (Mra) -THIOKOL LOT LA -10T3--01 +5.C THIOKOL LOT JA-IEZ35--Z-02 JAZ LOT HCL03JO14-001 -28.00 AE J>:T? +0.00 4.00 0.0 .0 *20.0 O30 +40M0...WARREN MI 48397-5000 MATERIAL SCIENCE TEAM AMSSB RSS 14 BENET LABORATORIES J HERBERT AMSTA AR CCB M SENNETT R FISCELLA KANSAS ST M SOJA NATICK MA 01760

Significance of TP53 Mutation in Wilms Tumors with Diffuse Anaplasia: A Report from the Children's Oncology Group.

PubMed

Ooms, Ariadne H A G; Gadd, Samantha; Gerhard, Daniela S; Smith, Malcolm A; Guidry Auvil, Jaime M; Meerzaman, Daoud; Chen, Qing-Rong; Hsu, Chih Hao; Yan, Chunhua; Nguyen, Cu; Hu, Ying; Ma, Yussanne; Zong, Zusheng; Mungall, Andrew J; Moore, Richard A; Marra, Marco A; Huff, Vicki; Dome, Jeffrey S; Chi, Yueh-Yun; Tian, Jing; Geller, James I; Mullighan, Charles G; Ma, Jing; Wheeler, David A; Hampton, Oliver A; Walz, Amy L; van den Heuvel-Eibrink, Marry M; de Krijger, Ronald R; Ross, Nicole; Gastier-Foster, Julie M; Perlman, Elizabeth J

2016-11-15

To investigate the role and significance of TP53 mutation in diffusely anaplastic Wilms tumors (DAWTs). All DAWTs registered on National Wilms Tumor Study-5 (n = 118) with available samples were analyzed for TP53 mutations and copy loss. Integrative genomic analysis was performed on 39 selected DAWTs. Following analysis of a single random sample, 57 DAWTs (48%) demonstrated TP53 mutations, 13 (11%) copy loss without mutation, and 48 (41%) lacked both [defined as TP53-wild-type (wt)]. Patients with stage III/IV TP53-wt DAWTs (but not those with stage I/II disease) had significantly lower relapse and death rates than those with TP53 abnormalities. In-depth analysis of a subset of 39 DAWTs showed seven (18%) to be TP53-wt: These demonstrated gene expression evidence of an active p53 pathway. Retrospective pathology review of TP53-wt DAWT revealed no or very low volume of anaplasia in six of seven tumors. When samples from TP53-wt tumors known to contain anaplasia histologically were available, abnormal p53 protein accumulation was observed by immunohistochemistry. These data support the key role of TP53 loss in the development of anaplasia in WT, and support its significant clinical impact in patients with residual anaplastic tumor following surgery. These data also suggest that most DAWTs will show evidence of TP53 mutation when samples selected for the presence of anaplasia are analyzed. This suggests that modifications of the current criteria to also consider volume of anaplasia and documentation of TP53 aberrations may better reflect the risk of relapse and death and enable optimization of therapeutic stratification. Clin Cancer Res; 22(22); 5582-91. ©2016 AACR. ©2016 American Association for Cancer Research.

Lens Model and Time Delay Predictions for the Sextuply Lensed Quasar SDSS J2222+2745*

NASA Technical Reports Server (NTRS)

Sharon, Keren; Bayliss, Matthew B.; Dahle, Hakon; Florian, Michael K.; Gladders, Michael D.; Johnson, Traci L.; Paterno-Mahler, Rachel; Rigby, Jane R.; Whitaker, Katherine E.; Wuyts, Eva

2017-01-01

SDSS J2222+2745 is a galaxy cluster at z = 0.49, strongly lensing a quasar at z = 2.805 into six widely separated images. In recent Hubble Space Telescope imaging of the field, we identify additional multiply lensed galaxies and confirm the sixth quasar image that was identified by Dahle et al. We used the Gemini-North telescope to measure a spectroscopic redshift of z = 4.56 of one of the lensed galaxies. These data are used to refine the lens model of SDSS J2222+2745, compute the time delay and magnifications of the lensed quasar images, and reconstruct the source image of the quasar host and a lensed galaxy at z = 2.3. This galaxy also appears in absorption in our Gemini spectra of the lensed quasar, at a projected distance of 34 kpc. Our model is in agreement with the recent time delay measurements of Dahle et al., who found T(sub AB) = 47.7 +/- 6.0 days and T(sub AC) = 722 +/- 24 days. We use the observed time delays to further constrain the model, and find that the model-predicted time delays of the three faint images of the quasar are T(sub AD) = 502+/- 68 days, T( sub AE) = 611 +/- 75 days, and T(sub AF) = 415 +/- 72 days. We have initiated a follow-up campaign to measure these time delays with Gemini North. Finally, we present initial results from an X-ray monitoring program with Swift, indicating the presence of hard X-ray emission from the lensed quasar, as well as extended X-ray emission from the cluster itself, which is consistent with the lensing mass measurement and the cluster velocity dispersion.

LENS MODEL AND TIME DELAY PREDICTIONS FOR THE SEXTUPLY LENSED QUASAR SDSS J2222+2745

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sharon, Keren; Johnson, Traci L.; Paterno-Mahler, Rachel

2017-01-20

SDSS J2222+2745 is a galaxy cluster at z = 0.49, strongly lensing a quasar at z = 2.805 into six widely separated images. In recent Hubble Space Telescope imaging of the field, we identify additional multiply lensed galaxies and confirm the sixth quasar image that was identified by Dahle et al. We used the Gemini-North telescope to measure a spectroscopic redshift of z = 4.56 of one of the lensed galaxies. These data are used to refine the lens model of SDSS J2222+2745, compute the time delay and magnifications of the lensed quasar images, and reconstruct the source image ofmore » the quasar host and a lensed galaxy at z = 2.3. This galaxy also appears in absorption in our Gemini spectra of the lensed quasar, at a projected distance of 34 kpc. Our model is in agreement with the recent time delay measurements of Dahle et al., who found τ {sub AB} = 47.7 ± 6.0 days and τ {sub AC} = −722 ± 24 days. We use the observed time delays to further constrain the model, and find that the model-predicted time delays of the three faint images of the quasar are τ {sub AD} = 502 ± 68 days, τ {sub AE} = 611 ± 75 days, and τ {sub AF} = 415 ± 72 days. We have initiated a follow-up campaign to measure these time delays with Gemini North. Finally, we present initial results from an X-ray monitoring program with Swift , indicating the presence of hard X-ray emission from the lensed quasar, as well as extended X-ray emission from the cluster itself, which is consistent with the lensing mass measurement and the cluster velocity dispersion.« less

Nitridation of SiO2 for surface passivation

NASA Technical Reports Server (NTRS)

Lai, S. K. C.

1985-01-01

An attempt is made to relate the electrical properties of silicon dioxide film to the process history. A model is proposed to explain some of the observed results. It is shown that with our present knowledge of the dielectric, silicon dioxide film shows a lot of promise for its use in surface passivation, both for its resistance to impurity diffusion and for its resistance to radiation damage effects.

How do temperature and rainfall affect nitrous oxide emissions from open-lot beef cattle feedyard pens?

USDA-ARS?s Scientific Manuscript database

Temperature is a primary factor affecting greenhouse gas (GHG) emissions from agricultural soils, but little is known about how temperature affects nitrous oxide (N2O) emissions from manure. The majority of grain-fed cattle in the Texas Panhandle are finished in large, earthen-surfaced, open-lot fee...

[Peroperative peritoneal lavage and intra-abdominal instillation of antibiotics in an experiment].

PubMed

Batalík, B; Mydlo, J

1991-03-01

The authors present the results of an experiment on dogs where lethal diffuse peritonitis was induced in the standard way and was treated only by peroperative peritoneal lavage during reoperation within 24 hours. In the first group (n = 10) this method alone reduced the mortality despite the adverse prognosis to 70%, after addition of an effective antibiotic and metronidazole into the last lot of the lavage solution in the second equally sized group to 10%. The results prove a marked therapeutic asset of this method which as part of comprehensive treatment of peritonitis improves substantially the final effect also under clinical conditions.

Deflection test evaluation of different lots of the same nickel-titanium wire commercial brand

PubMed Central

Neves, Murilo Gaby; Lima, Fabrício Viana Pereira; Gurgel, Júlio de Araújo; Pinzan-Vercelino, Célia Regina Maio; Rezende, Fernanda Soares; Brandão, Gustavo Antônio Martins

2016-01-01

Introduction: The aim of this in vitro study was to compare the elastic properties of the load-deflection ratio of orthodontic wires of different lot numbers and the same commercial brand. Methods: A total of 40 nickel-titanium (NiTi) wire segments (Morelli OrtodontiaTM - Sorocaba, SP, Brazil), 0.016-in in diameter were used. Groups were sorted according to lot numbers (lots 1, 2, 3 and 4). 28-mm length segments from the straight portion (ends) of archwires were used. Deflection tests were performed in an EMIC universal testing machine with 5-N load cell at 1 mm/minute speed. Force at deactivation was recorded at 0.5, 1, 2 and 3 mm deflection. Analysis of variance (ANOVA) was used to compare differences between group means. Results: When comparing the force of groups at the same deflection (3, 2 and 1 mm), during deactivation, no statistical differences were found. Conclusion: There are no changes in the elastic properties of different lots of the same commercial brand; thus, the use of different lots of the orthodontic wires used in this research does not compromise the final outcomes of the load-deflection ratio. PMID:27007760

Deflection test evaluation of different lots of the same nickel-titanium wire commercial brand.

PubMed

Neves, Murilo Gaby; Lima, Fabrício Viana Pereira; Gurgel, Júlio de Araújo; Pinzan-Vercelino, Célia Regina Maio; Rezende, Fernanda Soares; Brandão, Gustavo Antônio Martins

2016-01-01

The aim of this in vitro study was to compare the elastic properties of the load-deflection ratio of orthodontic wires of different lot numbers and the same commercial brand. A total of 40 nickel-titanium (NiTi) wire segments (Morelli Ortodontia™--Sorocaba, SP, Brazil), 0.016-in in diameter were used. Groups were sorted according to lot numbers (lots 1, 2, 3 and 4). 28-mm length segments from the straight portion (ends) of archwires were used. Deflection tests were performed in an EMIC universal testing machine with 5-N load cell at 1 mm/minute speed. Force at deactivation was recorded at 0.5, 1, 2 and 3 mm deflection. Analysis of variance (ANOVA) was used to compare differences between group means. When comparing the force of groups at the same deflection (3, 2 and 1 mm), during deactivation, no statistical differences were found. There are no changes in the elastic properties of different lots of the same commercial brand; thus, the use of different lots of the orthodontic wires used in this research does not compromise the final outcomes of the load-deflection ratio.

Arsenic-Rich Polyarsenides Stabilized by Cp*Fe Fragments.

PubMed

Schmidt, Monika; Konieczny, David; Peresypkina, Eugenia V; Virovets, Alexander V; Balázs, Gabor; Bodensteiner, Michael; Riedlberger, Felix; Krauss, Hannes; Scheer, Manfred

2017-06-12

The redox chemistry of [Cp*Fe(η 5 -As 5 )] (1, Cp*=η 5 -C 5 Me 5 ) has been investigated by cyclic voltammetry, revealing a redox behavior similar to that of its lighter congener [Cp*Fe(η 5 -P 5 )]. However, the subsequent chemical reduction of 1 by KH led to the formation of a mixture of novel As n scaffolds with n up to 18 that are stabilized only by [Cp*Fe] fragments. These include the arsenic-poor triple-decker complex [K(dme) 2 ][{Cp*Fe(μ,η 2:2 -As 2 )} 2 ] (2) and the arsenic-rich complexes [K(dme) 3 ] 2 [(Cp*Fe) 2 (μ,η 4:4 -As 10 )] (3), [K(dme) 2 ] 2 [(Cp*Fe) 2 (μ,η 2:2:2:2 -As 14 )] (4), and [K(dme) 3 ] 2 [(Cp*Fe) 4 (μ 4 ,η 4:3:3:2:2:1:1 -As 18 )] (5). Compound 4 and the polyarsenide complex 5 are the largest anionic As n ligand complexes reported thus far. Complexes 2-5 were characterized by single-crystal X-ray diffraction, 1 H NMR spectroscopy, EPR spectroscopy (2), and mass spectrometry. Furthermore, DFT calculations showed that the intermediate [Cp*Fe(η 5 -As 5 )] - , which is presumably formed first, undergoes fast dimerization to the dianion [(Cp*Fe) 2 (μ,η 4:4 -As 10 )] 2- . © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

H-alpha observations of Sh2-190, Sh2-222, Sh2-229, Sh2-236 HII regions

NASA Astrophysics Data System (ADS)

Sahan, Muhittin

2018-02-01

Hα spectral line (6563Å) profiles of four northern HII regions in the our galaxy (Sh2-190, Sh2-222, Sh2-229, Sh2-236) have been obtained using DEFPOS spectrometer, located at coude focus of 150 cm RTT150 telescope at TUBITAK National Observatory (TUG, Antalya, Turkey). Observations were carried out at nights of 2015 December 24-27 with long exposure times ranging from 900s to 3600s. The LSR velocities and the linewidths (Full Width Half Maximum: FWHM) of the Hα emission lines were found to be in the range of -45.46 kms-1 to +3.57 kms-1 and 38.50 kms-1 to 44.10 kms-1, respectively. The Sh2-229 HII region is the faintest one (211.16 R), while the Sh2-236 HII region (IC410) is brightest source (535.75 R). The LSR velocity and the line width (FWHM) results of the DEFPOS/RTT150 system were compared with the data by several authors given in literature and results of DEFPOS data were found to be in good agreement with data given in literature.

OBLIQUE PHOTO OF NORTH AND WEST ELEVATIONS OF REMOTE ANALYTICAL ...

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

OBLIQUE PHOTO OF NORTH AND WEST ELEVATIONS OF REMOTE ANALYTICAL FACILITY (CPP-627) LOOKING SOUTHEAST. LABORATORY AND OFFICE BUILDING (CPP-602) APPEAR ON LEFT IN PHOTO. INL PHOTO NUMBER HD-22-2-2. Mike Crane, Photographer, 11/1998 - Idaho National Engineering Laboratory, Idaho Chemical Processing Plant, Fuel Reprocessing Complex, Scoville, Butte County, ID

Nitrous Oxide Production in Co- Versus Counter-Diffusion Nitrifying Biofilms

NASA Astrophysics Data System (ADS)

Peng, Lai; Sun, Jing; Liu, Yiwen; Dai, Xiaohu; Ni, Bing-Jie

2016-06-01

For the application of biofilm processes, a better understanding of nitrous oxide (N2O) formation within the biofilm is essential for design and operation of biofilm reactors with minimized N2O emissions. In this work, a previously established N2O model incorporating both ammonia oxidizing bacteria (AOB) denitrification and hydroxylamine (NH2OH) oxidation pathways is applied in two structurally different biofilm systems to assess the effects of co- and counter-diffusion on N2O production. It is demonstrated that the diffusion of NH2OH and oxygen within both types of biofilms would form an anoxic layer with the presence of NH2OH and nitrite ( ), which would result in a high N2O production via AOB denitrification pathway. As a result, AOB denitrification pathway is dominant over NH2OH oxidation pathway within the co- and counter-diffusion biofilms. In comparison, the co-diffusion biofilm may generate substantially higher N2O than the counter-diffusion biofilm due to the higher accumulation of NH2OH in co-diffusion biofilm, especially under the condition of high-strength ammonium influent (500 mg N/L), thick biofilm depth (300 μm) and moderate oxygen loading (~1-~4 m3/d). The effect of co- and counter-diffusion on N2O production from the AOB biofilm is minimal when treating low-strength nitrogenous wastewater.

Nitrous Oxide Production in Co- Versus Counter-Diffusion Nitrifying Biofilms

PubMed Central

Peng, Lai; Sun, Jing; Liu, Yiwen; Dai, Xiaohu; Ni, Bing-Jie

2016-01-01

For the application of biofilm processes, a better understanding of nitrous oxide (N2O) formation within the biofilm is essential for design and operation of biofilm reactors with minimized N2O emissions. In this work, a previously established N2O model incorporating both ammonia oxidizing bacteria (AOB) denitrification and hydroxylamine (NH2OH) oxidation pathways is applied in two structurally different biofilm systems to assess the effects of co- and counter-diffusion on N2O production. It is demonstrated that the diffusion of NH2OH and oxygen within both types of biofilms would form an anoxic layer with the presence of NH2OH and nitrite ( ), which would result in a high N2O production via AOB denitrification pathway. As a result, AOB denitrification pathway is dominant over NH2OH oxidation pathway within the co- and counter-diffusion biofilms. In comparison, the co-diffusion biofilm may generate substantially higher N2O than the counter-diffusion biofilm due to the higher accumulation of NH2OH in co-diffusion biofilm, especially under the condition of high-strength ammonium influent (500 mg N/L), thick biofilm depth (300 μm) and moderate oxygen loading (~1–~4 m3/d). The effect of co- and counter-diffusion on N2O production from the AOB biofilm is minimal when treating low-strength nitrogenous wastewater. PMID:27353382

20 CFR 222.2 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-04-01

... Act due to an entitlement claimant for a calendar month and made to him or her on the first day of the following month. Apply means to sign a form or statement that the Railroad Retirement Board accepts as an... parties to the status of single persons; it is also referred to as an absolute divorce. Finally divorced...

40 CFR 52.128 - Rule for unpaved parking lots, unpaved roads and vacant lots.

Code of Federal Regulations, 2011 CFR

2011-07-01

... where the exemption in paragraph (c)(2) of this section applies. (9) Motor vehicle—A self-propelled.... Research Triangle Park, N.C. May 1982. 3. “Method 9—Visible Determination of the Opacity of Emissions from... of the human eye—Reference 4.1 of section 4.) c. Angle of view 15 degrees maximum total angle d...

40 CFR 52.128 - Rule for unpaved parking lots, unpaved roads and vacant lots.

Code of Federal Regulations, 2010 CFR

2010-07-01

... where the exemption in paragraph (c)(2) of this section applies. (9) Motor vehicle—A self-propelled.... Research Triangle Park, N.C. May 1982. 3. “Method 9—Visible Determination of the Opacity of Emissions from... of the human eye—Reference 4.1 of section 4.) c. Angle of view 15 degrees maximum total angle d...

Simulation study on compressive laminar optical tomography for cardiac action potential propagation

PubMed Central

Harada, Takumi; Tomii, Naoki; Manago, Shota; Kobayashi, Etsuko; Sakuma, Ichiro

2017-01-01

To measure the activity of tissue at the microscopic level, laminar optical tomography (LOT), which is a microscopic form of diffuse optical tomography, has been developed. However, obtaining sufficient recording speed to determine rapidly changing dynamic activity remains major challenges. For a high frame rate of the reconstructed data, we here propose a new LOT method using compressed sensing theory, called compressive laminar optical tomography (CLOT), in which novel digital micromirror device-based illumination and data reduction in a single reconstruction are applied. In the simulation experiments, the reconstructed volumetric images of the action potentials that were acquired from 5 measured images with random pattern featured a wave border at least to a depth of 2.5 mm. Consequently, it was shown that CLOT has potential for over 200 fps required for the cardiac electrophysiological phenomena. PMID:28736675

Polymorphism of a widely used building block for halogen-bonded assemblies: 1,3,5-trifluoro-2,4,6-triiodobenzene.

PubMed

Raffo, Pablo A; Suárez, Sebastián; Fantoni, Adolfo C; Baggio, Ricardo; Cukiernik, Fabio D

2017-09-01

After reporting the structure of a new polymorph of 1,3,5-trifluoro-2,4,6-triiodobenzene (denoted BzF3I3), C 6 F 3 I 3 , (I), which crystallized in the space group P2 1 /c, we perform a comparative analysis with the already reported P2 1 /n polymorph, (II) [Reddy et al. (2006). Chem. Eur. J. 12, 2222-2234]. In polymorph (II), type-II I...I halogen bonds and I...π interactions connect molecules in such a way that a three-dimensional structure is formed; however, the way in which molecules are connected in polymorph (I), through type-II I...I halogen bonds and π-π interactions, gives rise to an exfoldable lamellar structure, which looks less tightly bound than that of (II). In agreement with this structural observation, both the melting point and the melting enthalpy of (I) are lower than those of (II).

Feature-Oriented Domain Analysis (FODA) Feasibility Study

DTIC Science & Technology

1990-11-01

controlling the synchronous behavior of the task. A task may wait for one or more synchronizing or message queue events. "* Each task is designed using the...Comparative Study 13 2.2.1. The Genesis System 13 2.2.2. MCC Work 15 2.2.2.1. The DESIRE Design Recovery Tool 15 0 2.2.2.2. Domain Analysis Method 1f...Illustration 43 Figure 6-1: Architectural Layers 48 Figure 6-2: Window Management Subsystem Design Structure 49 Figure 7-1: Function of a Window Manager

Growth of enterotoxigenic Staphylococcus aureus in povi masima, a traditional Pacific island food.

PubMed

Wong, T L; Whyte, R J; Graham, C G; Saunders, D; Schumacher, J; Hudson, J A

2004-01-01

To obtain preliminary data on the microbiology and hurdles to pathogen growth in the traditional Pacific Island food, povi masima, which is essentially beef brisket cured in brine. Six containers of povi masima were prepared and two were inoculated with five enterotoxigenic strains of Staphyloccocus aureus. The povi masima were divided into two lots each containing two uninoculated control and an inoculated container. Lot 1 was incubated at room temperature (20 degrees C) and lot 2 under refrigeration (4-5 degrees C) for up to 98 days. During storage, samples were removed and tested for aerobic plate count, coagulase-producing Staphylococci, Clostridium perfringens, staphylococcal enterotoxin and various chemical parameters of the food. Coagulase-producing Staphylococci and aerobic plate counts grew to high levels in both the inoculated and uninoculated lots stored at room temperature, but enterotoxin was only detected at one time point in these lots and this may represent a false positive result. The concentration of NaCl in the meat increased with time as concentrations equilibrated, and nitrite was rapidly lost in those lots stored at room temperature. Storage at 4-5 degrees C prevented proliferation of coagulase-producing Staphylococci. For safe curing and storage, this food should be kept under refrigeration as this prevented growth of staphylococci. Optimum storage would also be achieved with improved attempts to ensure equal distribution of NaCl prior to storage. Under conditions traditionally used to cure and store this food, enterotoxigenic staphylococci can grow to numbers where toxigenesis might occur, especially during the early stages of curing where the salt has not diffused from the brine into the meat.

Safety, immunogenicity, and lot-to-lot consistency of a split-virion quadrivalent influenza vaccine in younger and older adults: A phase III randomized, double-blind clinical trial

PubMed Central

Sesay, Sanie; Brzostek, Jerzy; Meyer, Ingo; Donazzolo, Yves; Leroux-Roels, Geert; Rouzier, Régine; Astruc, Béatrice; Szymanski, Henryk; Toursarkissian, Nicole; Vandermeulen, Corinne; Kowalska, Edyta; Van Damme, Pierre; Salamand, Camille; Pepin, Stephanie

2018-01-01

ABSTRACT Here, we report a randomized multicenter phase III trial assessing the lot-to-lot consistency of the 2014–2015 Northern Hemisphere quadrivalent split-virion inactivated influenza vaccine (IIV4; Sanofi Pasteur) and comparing its immunogenicity and safety with that of trivalent inactivated influenza vaccine (IIV3) in younger and older adults (EudraCT no. 2014-000785-21). Younger (18–60 y, n = 1114) and older (>60 y, n = 1111) adults were randomized 2:2:2:1:1 to receive a single dose of one of three lots of IIV4, the licensed IIV3 containing the B Yamagata lineage strain, or an investigational IIV3 containing the B Victoria lineage strain. Post-vaccination (day 21) hemagglutination inhibition antibody titers were equivalent for the three IIV4 lots. For the pooled IIV4s vs. IIV3, hemagglutination inhibition antibody titers were also non-inferior for the A strains, non-inferior for the B strain when present in the comparator IIV3, and superior for the B strain lineage when absent from the comparator IIV3. For all vaccine strains, seroprotection rates were ≥98% in younger adults and ≥90% in older adults. IIV4 also increased seroneutralizing antibody titers against all three vaccine strains of influenza. All vaccines were well tolerated, with no safety concerns identified. Solicited injection-site reactions were similar for IIV4 and IIV3 and mostly grade 1 and transient. This study showed that in younger and older adults, IIV4 had a similar safety profile as the licensed IIV3 and that including a second B strain lineage in IIV4 provided superior immunogenicity for the added B strain without affecting the immunogenicity of the three IIV3 strains. PMID:28968138

AlGaN/GaN heterostructures with an AlGaN layer grown directly on reactive-ion-etched GaN showing a high electron mobility (>1300 cm2 V-1 s-1)

NASA Astrophysics Data System (ADS)

Yamamoto, Akio; Makino, Shinya; Kanatani, Keito; Kuzuhara, Masaaki

2018-04-01

In this study, the metal-organic-vapor-phase-epitaxial growth behavior and electrical properties of AlGaN/GaN structures prepared by the growth of an AlGaN layer on a reactive-ion-etched (RIE) GaN surface without regrown GaN layers were investigated. The annealing of RIE-GaN surfaces in NH3 + H2 atmosphere, employed immediately before AlGaN growth, was a key process in obtaining a clean GaN surface for AlGaN growth, that is, in obtaining an electron mobility as high as 1350 cm2 V-1 s-1 in a fabricated AlGaN/RIE-GaN structure. High-electron-mobility transistors (HEMTs) were successfully fabricated with AlGaN/RIE-GaN wafers. With decreasing density of dotlike defects observed on the surfaces of AlGaN/RIE-GaN wafers, both two-dimensional electron gas properties of AlGaN/RIE-GaN structures and DC characteristics of HEMTs were markedly improved. Since dotlike defect density was markedly dependent on RIE lot, rather than on growth lot, surface contaminations of GaN during RIE were believed to be responsible for the formation of dotlike defects and, therefore, for the inferior electrical properties.

Community of Interest Engagement Process Plan

DTIC Science & Technology

2012-02-09

and input from Subject Matter Experts (SMEs), as shown in the far left of Figure 2. The team may prepare a Business Process Model Notation ( BPMN ) 22...22 Business Process Modeling Notation ( BPMN ) is a method of illustrating business processes in the form of a...Community of Interest Engagement Plan Joint Planning and Development Office 21 10. Acronyms BPMN Business Process Modeling Notation COI

Elevated temperature creep properties of NiAl cryomilled with and without Y2O3

NASA Technical Reports Server (NTRS)

Whittenberger, J. Daniel; Luton, Michael J.

1995-01-01

The creep properties of lots of NiAl cryomilled with and without Y2O3 have been determined in compression and tension. Although identical cryomilling procedures were used, differences in composition were found between the lot ground with 0.5 vol% yttria and the lot ground without Y2O3. Compression testing between 1000 and 1300 K yielded similar creep strengths for both materials, while tensile creep rupture testing indicated that the yttria-containing alloy was slightly stronger than the Y2O3-free version. Both compression and tensile testing showed two deformation regimes; whereas the stress state did not affect the high stress exponent (n approximately equals 10) mechanism, the low stress exponent regime n was approximately 6 in tension and approximately 2 in compression. The strengths in tension were somewhat less than those measured in compression, but the estimated activation energies (Q) of approximately 600 kJ/mol for tensile testing were closer to the previously measured values (approximately 700 kJ/mol) for NiAl-AlN and very different from the Q's of 400 and 200 kJ/mol for compression tests in the high and low stress exponent regimes, respectively. A Larson-Miller comparison indicated that cryomilling can produce an alloy with long-term, high-temperature strength at least equal to conventional superalloys.

Lens Model and Time Delay Predictions for the Sextuply Lensed Quasar SDSS J2222+2745

NASA Astrophysics Data System (ADS)

Sharon, Keren; Bayliss, Matthew B.; Dahle, Håkon; Florian, Michael K.; Gladders, Michael D.; Johnson, Traci L.; Paterno-Mahler, Rachel; Rigby, Jane R.; Whitaker, Katherine E.; Wuyts, Eva

2017-01-01

SDSS J2222+2745 is a galaxy cluster at z = 0.49, strongly lensing a quasar at z = 2.805 into six widely separated images. In recent Hubble Space Telescope imaging of the field, we identify additional multiply lensed galaxies and confirm the sixth quasar image that was identified by Dahle et al. We used the Gemini-North telescope to measure a spectroscopic redshift of z = 4.56 of one of the lensed galaxies. These data are used to refine the lens model of SDSS J2222+2745, compute the time delay and magnifications of the lensed quasar images, and reconstruct the source image of the quasar host and a lensed galaxy at z = 2.3. This galaxy also appears in absorption in our Gemini spectra of the lensed quasar, at a projected distance of 34 kpc. Our model is in agreement with the recent time delay measurements of Dahle et al., who found τAB = 47.7 ± 6.0 days and τAC = -722 ± 24 days. We use the observed time delays to further constrain the model, and find that the model-predicted time delays of the three faint images of the quasar are τAD = 502 ± 68 days, τAE = 611 ± 75 days, and τAF = 415 ± 72 days. We have initiated a follow-up campaign to measure these time delays with Gemini North. Finally, we present initial results from an X-ray monitoring program with Swift, indicating the presence of hard X-ray emission from the lensed quasar, as well as extended X-ray emission from the cluster itself, which is consistent with the lensing mass measurement and the cluster velocity dispersion. Based on observations made with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555. These observations are associated with program GO-13337.

Effect of SiN x diffusion barrier thickness on the structural properties and photocatalytic activity of TiO2 films obtained by sol-gel dip coating and reactive magnetron sputtering.

PubMed

Ghazzal, Mohamed Nawfal; Aubry, Eric; Chaoui, Nouari; Robert, Didier

2015-01-01

We investigate the effect of the thickness of the silicon nitride (SiN x ) diffusion barrier on the structural and photocatalytic efficiency of TiO2 films obtained with different processes. We show that the structural and photocatalytic efficiency of TiO2 films produced using soft chemistry (sol-gel) and physical methods (reactive sputtering) are affected differentially by the intercalating SiN x diffusion barrier. Increasing the thickness of the SiN x diffusion barrier induced a gradual decrease of the crystallite size of TiO2 films obtained by the sol-gel process. However, TiO2 obtained using the reactive sputtering method showed no dependence on the thickness of the SiN x barrier diffusion. The SiN x barrier diffusion showed a beneficial effect on the photocatalytic efficiency of TiO2 films regardless of the synthesis method used. The proposed mechanism leading to the improvement in the photocatalytic efficiency of the TiO2 films obtained by each process was discussed.

Diffusion of two-dimensional epitaxial clusters on metal (100) surfaces: Facile versus nucleation-mediated behavior and their merging for larger sizes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lai, King C.; Liu, Da -Jiang; Evans, James W.

For diffusion of two-dimensional homoepitaxial clusters of N atoms on metal(100) surfaces mediated by edge atom hopping, macroscale continuum theory suggests that the diffusion coefficient scales like DN ~ N -β with β = 3/2. However, we find quite different and diverse behavior in multiple size regimes. These include: (i) facile diffusion for small sizes N < 9; (ii) slow nucleation-mediated diffusion with small β < 1 for “perfect” sizes N = N p = L 2 or L(L+1), for L = 3, 4,… having unique ground state shapes, for moderate sizes 9 ≤ N ≤ O(10 2); the samemore » also applies for N = N p +3, N p + 4,… (iii) facile diffusion but with large β > 2 for N = Np + 1 and N p + 2 also for moderate sizes 9 ≤ N ≤ O(10 2); (iv) merging of the above distinct branches and subsequent anomalous scaling with 1 ≲ β < 3/2, reflecting the quasi-facetted structure of clusters, for larger N = O(10 2) to N = O(10 3); and (v) classic scaling with β = 3/2 for very large N = O(103) and above. The specified size ranges apply for typical model parameters. We focus on the moderate size regime where show that diffusivity cycles quasi-periodically from the slowest branch for N p + 3 (not Np) to the fastest branch for Np + 1. Behavior is quantified by Kinetic Monte Carlo simulation of an appropriate stochastic lattice-gas model. However, precise analysis must account for a strong enhancement of diffusivity for short time increments due to back-correlation in the cluster motion. Further understanding of this enhancement, of anomalous size scaling behavior, and of the merging of various branches, is facilitated by combinatorial analysis of the number of the ground state and low-lying excited state cluster configurations, and also of kink populations.« less

Diffusion of two-dimensional epitaxial clusters on metal (100) surfaces: Facile versus nucleation-mediated behavior and their merging for larger sizes

DOE PAGES

Lai, King C.; Liu, Da -Jiang; Evans, James W.

2017-12-05

For diffusion of two-dimensional homoepitaxial clusters of N atoms on metal(100) surfaces mediated by edge atom hopping, macroscale continuum theory suggests that the diffusion coefficient scales like DN ~ N -β with β = 3/2. However, we find quite different and diverse behavior in multiple size regimes. These include: (i) facile diffusion for small sizes N < 9; (ii) slow nucleation-mediated diffusion with small β < 1 for “perfect” sizes N = N p = L 2 or L(L+1), for L = 3, 4,… having unique ground state shapes, for moderate sizes 9 ≤ N ≤ O(10 2); the samemore » also applies for N = N p +3, N p + 4,… (iii) facile diffusion but with large β > 2 for N = Np + 1 and N p + 2 also for moderate sizes 9 ≤ N ≤ O(10 2); (iv) merging of the above distinct branches and subsequent anomalous scaling with 1 ≲ β < 3/2, reflecting the quasi-facetted structure of clusters, for larger N = O(10 2) to N = O(10 3); and (v) classic scaling with β = 3/2 for very large N = O(103) and above. The specified size ranges apply for typical model parameters. We focus on the moderate size regime where show that diffusivity cycles quasi-periodically from the slowest branch for N p + 3 (not Np) to the fastest branch for Np + 1. Behavior is quantified by Kinetic Monte Carlo simulation of an appropriate stochastic lattice-gas model. However, precise analysis must account for a strong enhancement of diffusivity for short time increments due to back-correlation in the cluster motion. Further understanding of this enhancement, of anomalous size scaling behavior, and of the merging of various branches, is facilitated by combinatorial analysis of the number of the ground state and low-lying excited state cluster configurations, and also of kink populations.« less

Elevated Temperature Compressive Strength Properties of Oxide Dispersion Strengthened NiAl After Cryo-milling and Roasting in Nitrogen

NASA Technical Reports Server (NTRS)

Whittenberger, J. Daniel; Grahle, Peter; Arzt, Eduard; Hebsur, Mohan

1998-01-01

In an effort to superimpose two different elevated temperature strengthening mechanisms in NiAl, several lots of oxide dispersion strengthened (ODS) NiAl powder have been cryo-milled in liquid nitrogen to introduce AlN particles at the grain boundaries. As an alternative to cryo-milling, one lot of ODS NiAl was roasted in nitrogen to produce AlN. Both techniques resulted in hot extruded AlN-strengthened, ODS NiAl alloys which were stronger than the base ODS NiAl between 1200 and 1400 K. However, neither the cryo-milled nor the N2-roasted ODS NiAl alloys were as strong as cryo-milled binary NiAl containing like amounts of AlN. The reason(s) for the relative weakness of cryo-milled ODS NiAl is not certain; however the lack of superior strength in N2-roasted ODS NiAl is probably due to its relatively large AlN particles.

Evidence that (-)-7-hydroxy-4'-dimethylheptyl-cannabidiol activates a non-CB(1), non-CB(2), non-TRPV1 target in the mouse vas deferens.

PubMed

Pertwee, Roger G; Thomas, Adèle; Stevenson, Lesley A; Maor, Yehoshua; Mechoulam, Raphael

2005-06-01

Previous experiments showed that R-(+)-WIN55212-induced inhibition of electrically-evoked contractions of mouse vasa deferentia could be antagonized by cannabidiol in a manner that appeared to be competitive but not to involve direct competition for established cannabinoid receptors. We have now discovered that (-)-7-hydroxy-4'-dimethylheptyl-cannabidiol (7-OH-DMH-CBD) inhibits electrically-evoked contractions of the vas deferens (EC(50)=13.3 nM). This it appeared to do by acting on prejunctional neurones as 100 nM 7-OH-DMH-CBD did not attenuate contractile responses to phenylephrine or beta,gamma-methylene-ATP. Although 7-OH-DMH-CBD was antagonized by SR141716A, it was less susceptible to antagonism by this CB(1) receptor antagonist than R-(+)-WIN55212. 7-OH-DMH-CBD was also antagonized by cannabidiol (1 microM; apparent K(B)=222.2 nM) but not by the CB(2) receptor antagonist, SR144528 (32 nM), or by naloxone (300 nM), ruthenium red (1 microM) or capsazepine (10 microM). Yohimbine (100 nM) enhanced the ability of 7-OH-DMH-CBD to inhibit electrically-evoked contractions. R-(+)-WIN55212 was also potentiated by 100 nM yohimbine, possibly reflecting ongoing sequestration of G(i/o) proteins from CB(1) receptors by alpha(2)-adrenoceptors. Our results suggest that 7-OH-DMH-CBD may activate a neuronal target in the vas deferens that is not a CB(1), CB(2), TRPV1, opioid or alpha(2)-adrenergic receptor but do not exclude the possibility that it also activates CB(1) receptors.

Spatially resolved emission of a high-redshift DLA galaxy with the Keck/OSIRIS IFU

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jorgenson, Regina A.; Wolfe, Arthur M., E-mail: raj@ifa.hawaii.edu

2014-04-10

We present the first Keck/OSIRIS infrared IFU observations of a high-redshift damped Lyα (DLA) galaxy detected in the line of sight to a background quasar. By utilizing the Laser Guide Star Adaptive Optics to reduce the quasar point-spread function to FWHM ∼ 0.''15, we were able to search for and map the foreground DLA emission free from the quasar contamination. We present maps of the Hα and [O III] λλ5007, 4959 emission of DLA 2222–0946 at a redshift of z ∼ 2.35. From the composite spectrum over the Hα emission region, we measure a star formation rate of 9.5 ±more » 1.0 M {sub ☉} yr{sup –1} and a dynamical mass of M {sub dyn} = 6.1 × 10{sup 9} M {sub ☉}. The average star formation rate surface density is (Σ{sub SFR}) = 0.55 M {sub ☉} yr{sup –1} kpc{sup –2}, with a central peak of 1.7 M {sub ☉} yr{sup –1} kpc{sup –2}. Using the standard Kennicutt-Schmidt relation, this corresponds to a gas mass surface density of Σ{sub gas} = 243 M {sub ☉} pc{sup –2}. Integrating over the size of the galaxy, we find a total gas mass of M {sub gas} = 4.2 × 10{sup 9} M {sub ☉}. We estimate the gas fraction of DLA 2222–0946 to be f {sub gas} ∼ 40%. We detect [N II] λ6583 emission at 3σ significance with a flux corresponding to a metallicity of 75% solar. Comparing this metallicity with that derived from the low-ion absorption gas ∼6 kpc away, ∼30% solar, indicates possible evidence for a metallicity gradient or enriched in/outflow of gas. Kinematically, both Hα and [O III] emission show relatively constant velocity fields over the central galactic region. While we detect some red and blueshifted clumps of emission, they do not correspond with rotational signatures that support an edge-on disk interpretation.« less

Association of vaccine handling conditions with effectiveness of live attenuated influenza vaccine against H1N1pdm09 viruses in the United States.

PubMed

Caspard, Herve; Coelingh, Kathleen L; Mallory, Raburn M; Ambrose, Christopher S

2016-09-30

This analysis examined potential causes of the lack of vaccine effectiveness (VE) of live attenuated influenza vaccine (LAIV) against A/H1N1pdm09 viruses in the United States (US) during the 2013-2014 season. Laboratory studies have demonstrated reduced thermal stability of A/California/07/2009, the A/H1N1pdm09 strain utilized in LAIV from 2009 through 2013-2014. Post hoc analyses of a 2013-2014 test-negative case-control (TNCC) effectiveness study investigated associations between vaccine shipping conditions and LAIV lot effectiveness. Investigational sites provided the LAIV lot numbers administered to each LAIV recipient enrolled in the study, and the vaccine distributor used by the site for commercially purchased vaccine. Additionally, a review was conducted of 2009-2014 pediatric observational TNCC effectiveness studies of LAIV, summarizing effectiveness by type/subtype, season, and geographic location. From the 2013 to 2014 TNCC study, the proportion of LAIV recipients who tested positive for H1N1pdm09 was significantly higher among children who received a lot released between August 1 and September 15, 2013, compared with a lot shipped either earlier or later (21% versus 4%; P<0.01). A linear relationship was observed between the proportion of subjects testing positive for H1N1pdm09 and outdoor temperatures during truck unloading at distributors' central locations. The review of LAIV VE studies showed that in the 2010-2011 and 2013-2014 influenza seasons, no significant effectiveness of LAIV against H1N1pdm09 was demonstrated for the trivalent or quadrivalent formulations of LAIV in the US, respectively, in contrast to significant effectiveness against A/H3N2 and B strains during 2010-2014. This study showed that the lack of VE observed with LAIV in the US against H1N1pdm09 viruses was associated with exposure of some LAIV lots to temperatures above recommended storage conditions during US distribution, and is likely explained by the increased susceptibility of the A/California/7/2009 (H1N1pdm09) LAIV strain to thermal degradation. NCT01997450. Copyright © 2016 The Author(s). Published by Elsevier Ltd.. All rights reserved.

Study on the generation of perfluorooctane sulfonate from the aqueous film-forming foam.

PubMed

Kishi, Takahiro; Arai, Mitsuru

2008-11-15

Perfluorooctane sulfonate (C(8)HF(17)SO(3)) and perfluorooctane acid (C(8)HF(15)O(2)) are artificial chemicals and have been used all over the world, mainly as water repellent agents, fluorochemical surfactants, coating agents, etc. However, perfluorooctane sulfonate and perfluorooctane acid are environmental contaminants because of their stability, bio-accumulativeness, and long-term persistence in the ecological environment. At the present day, they are diffused all over the world. Lately, this diffusion is viewed with suspicion and there is a movement towards their restriction, even if the environmental fate of them is still under investigation. Fluorochemical surfactants are key compounds in the aqueous film-forming foam (AFFF) formulations. AFFFs are used for massive conflagration such as industrial fire and petroleum fire because of their efficient fire control. On the other hand, a lot of AFFFs are used in case of massive conflagration and most of them enter ocean and groundwater. Actually, perfluorooctane sulfonate and perfluorooctane sulfonate related substances were detected from the fire-fighting facility of US forces. Therefore, there is the possibility of generating perfluorooctane sulfonate and perfluorooctane sulfonate related substances from fluorochemical surfactants in the AFFFs. In this study, activated sludge added AFFF were analyzed for perfluorooctane sulfonate and perfluorooctane acid with time. And the perfluorooctane sulfonate was directly detected after 2 days using LC-MS. This shows that AFFF can be decomposed perfluorooctane sulfonate by microorganisms easily. However, perfluorooctane sulfonate would not decompose at all. Additionally, activated sludge added N-polyoxyethylene-N-propyl perfluorooctane sulfonamide which is one of the fluorochemical surfactants used in the AFFF was analyzed for perfluorooctane sulfonate and perfluorooctane acid with time and the perfluorooctane sulfonate was detected too.

Diurnal variation in greenhouse fluxes from a feedyard pen surface

USDA-ARS?s Scientific Manuscript database

Accurate estimation of greenhouse gas (GHG) emissions, including nitrous oxide (N2O) and methane (CH4) from open-lot beef cattle feedlots is an increasing concern given the current and potential future reporting requirements for GHG emissions. Research concerning N2O and CH4 emission fluxes from the...

Variability in surface infrared reflectance of thirteen nitrile rubber gloves at key wavelengths for analysis of captan.

PubMed

Phalen, R N; Que Hee, Shane S

2007-02-01

The aim of this study was to investigate the surface variability of 13 powder-free, unlined, and unsupported nitrile rubber gloves using attenuated total reflection Fourier transform infrared (ATR-FT-IR) spectrophotometry at key wavelengths for analysis of captan contamination. The within-glove, within-lot, and between-lot variability was measured at 740, 1124, 1252, and 1735 cm(-1), the characteristic captan reflectance minima wavelengths. Three glove brands were assessed after conditioning overnight at relative humidity (RH) values ranging from 2 +/- 1 to 87 +/- 4% and temperatures ranging from -8.6 +/- 0.7 to 59.2 +/- 0.9 degrees C. For all gloves, 1735 cm(-1) provided the lowest background absorbance and greatest potential sensitivity for captan analysis on the outer glove surface: absorbances ranged from 0.0074 +/- 0.0005 (Microflex) to 0.0195 +/- 0.0024 (SafeSkin); average within-glove coefficients of variation (CV) ranged from 2.7% (Best, range 0.9-5.3%) to 10% (SafeSkin, 1.2-17%); within-glove CVs greater than 10% were for one brand (SafeSkin); within-lot CVs ranged from 2.8% (Best N-Dex) to 28% (SafeSkin Blue); and between-lot variation was statistically significant (p < or = 0.05) for all but two SafeSkin lots. The RH had variable effects dependent on wavelength, being minimal at 1735, 1252, and 1124 cm(-1) and highest at 3430 cm(-1) (O-H stretch region). There was no significant effect of temperature conditioning. Substantial within-glove, within-lot, and between-lot variability was observed. Thus, surface analysis using ATR-FT-IR must treat glove brands and lots as different. ATR-FT-IR proved to be a useful real-time analytical tool for measuring glove variability, detecting surface humidity effects, and choosing selective and sensitive wavelengths for analysis of nonvolatile surface contaminants.

Greening vacant lots to reduce violent crime: a randomised controlled trial

PubMed Central

Garvin, Eugenia C; Cannuscio, Carolyn C; Branas, Charles C

2014-01-01

Background Vacant lots are often overgrown with unwanted vegetation and filled with trash, making them attractive places to hide illegal guns, conduct illegal activities such as drug sales and prostitution, and engage in violent crime. There is some evidence that greening vacant lots is associated with reductions in violent crime. Methods We performed a randomised controlled trial of vacant lot greening to test the impact of this intervention on police reported crime and residents’ perceptions of safety and disorder. Greening consisted of cleaning the lots, planting grass and trees, and building a wooden fence around the perimeter. We randomly allocated two vacant lot clusters to the greening intervention or to the control status (no intervention). Administrative data were used to determine crime rates, and local resident interviews at baseline (n=29) and at follow-up (n=21) were used to assess perceptions of safety and disorder. Results Unadjusted difference-in-differences estimates showed a non-significant decrease in the number of total crimes and gun assaults around greened vacant lots compared with control. People around the intervention vacant lots reported feeling significantly safer after greening compared with those living around control vacant lots (p<0.01). Conclusions In this study, greening was associated with reductions in certain gun crimes and improvements in residents’ perceptions of safety. A larger randomised controlled trial is needed to further investigate the link between vacant lot greening and violence reduction. PMID:22871378

Anaerobic soil volume as a major controlling factor for soil denitrification and respiration

NASA Astrophysics Data System (ADS)

Reent Köster, Jan; Tong, Bingxin; Grosz, Balázs; Burkart, Stefan; Ruoss, Nicolas; Well, Reinhard

2017-04-01

Gas diffusion in soil is a key variable to control denitrification and its N2O to N2 product ratio since it affects two major proximal denitrification factors, i.e. the concentrations of O2 and of N2O. Gas diffusivity is governed by the structure and the state of water saturation of the pore system. At a given O2 consumption rate decreasing diffusivity causes an enhanced anaerobic soil volume where denitrification can occur. Gas diffusivity is generally quantified as bulk diffusion coefficients that represent the lineal diffusive gas flux through the soil matrix. However, the spatial distribution of respiratory O2 consumption and denitrification - and hence the local concentration of O2 and N2O - is highly non-homogeneous. Knowledge of the anaerobic soil volume fraction (ansvf) has been proposed as a key control on denitrification, and has subsequently been used in many denitrification models. The ansvf has previously been quantified by direct measurement of O2 distribution in individual soil aggregates using microsensors. The measured ansvf corresponded to modelled values based on measured aggregate diffusivity and respiration, but was not yet correlated with measured denitrification rates. In the present ongoing study, we are incubating soil cores amended with nitrate and organic litter in an automated mesocosm system under aerobic as well as anaerobic conditions. An N2 depleted incubation atmosphere and the 15N labeled soil nitrate pool facilitate quantification of the N2 production in the soil by IRMS, and fluxes of N2O and CO2 are monitored via gas chromatography. The ansvf and the measured denitrification and respiration rates will then be used for model validation. During the session we will present first results of this study.

Management of male osteoporosis.

PubMed

Cortet, B; Vasseur, J; Grardel, B; Catanzariti, L; Marchandise, X; Delcambre, B

2001-05-01

The objective of this study was to evaluate the efficacy of treatments for male osteoporosis selected based on the cause of the disease. Sixty-three men with osteoporosis (T-score at the lumbar spine and/or femoral neck lower than -2.5) with a mean age of 53+/-11 years were studied. Forty-three (68.3%) had a history of fracturing without trauma (vertebral fractures, 37 patients, 57%). Treatments were as follows: idiopathic osteoporosis: calcium and vitamin D supplements (N = 10) or cyclical etidronate for 2 weeks followed by calcium and vitamin D supplements for 76 days (N = 29); moderate idiopathic phosphate diabetes: calcitriol and phosphate (N = 15); idiopathic hypercalciuria: hydrochlorothiazide (N = 6); and hypogonadism: testosterone (N = 3). Percentage change in bone mineral density (mean +/- standard error of the mean) after 18 months: calcium and vitamin D (lumbar spine: 0.6+/-2; femoral neck: 2.2+/-2.2); etidronate (lumbar spine: 3.6+/-1.4*; femoral neck: 0.5+/-1); calcitriol (lumbar spine: 7.0+/-3.5*; femoral neck: 0.0+/-1.4); thiazide diuretic (lumbar spine: 1+/-3.2; femoral neck: -2.3+/-3.7); and testosterone (lumbar spine: 6.8+/-6.4; femoral neck: 2.5+/-2.7), where *P < 0.05 versus baseline. Gastrointestinal side effects occurred in three patients (4.8%), including two on calcitriol-phosphate therapy and one on etidronate therapy. Of the six (9.5%) patients who experienced incident fractures, four were on etidronate, one on calcitriol-phosphate, and one on calcium-vitamin D. No patients discontinued their treatment because of side effects. Etidronate and the combination of calcitriol-phosphate produce a significant increase in lumbar spine bone mass in men with idiopathic osteoporosis or moderate idiopathic phosphate diabetes.

Preferential Ascus Discharge during Cross Maturation in SORDARIA BREVICOLLIS

PubMed Central

MacDonald, D. J.; Bond, D. J.

1974-01-01

Crosses involving spore color mutants of Sordaria brevicollis all showed a decline in the frequency of second division asymmetric asci (2:2:2:2's) as the cross matured. This decline was due to the preferential maturation and/or discharge of these asci. The proportion of spindle overlap and recombinational asci within the group did not change as shown by ascus dissection. The preferential discharge was also found to occur in two-point crosses where the asci did not contain wild-type spores. PMID:4822469

Preferential ascus discharge during cross maturation in Sordaria brevicollis.

PubMed

MacDonald, D J; Bond, D J

1974-02-01

Crosses involving spore color mutants of Sordaria brevicollis all showed a decline in the frequency of second division asymmetric asci (2:2:2:2's) as the cross matured. This decline was due to the preferential maturation and/or discharge of these asci. The proportion of spindle overlap and recombinational asci within the group did not change as shown by ascus dissection. The preferential discharge was also found to occur in two-point crosses where the asci did not contain wild-type spores.

Calcium-loaded 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid blocks cell-to-cell diffusion of carboxyfluorescein in staminal hairs of Setcreasea purpurea.

PubMed

Tucker, E B

1990-08-01

The effect of microinjected calcium-loaded 1,2-bis(2-aminophenoxy) ethane-N,N,N',N'-tetraacetic acid (CaBAPTA) on cell-to-cell diffusion of carboxyfluorescein (CF) was examined in staminal hairs of S. purpurea Boom. The CaBAPTA was microinjected into the cytoplasm of the staminal hairs either with CF or prior to a subsequent microinjection of CF. The cell-to-cell diffusion of CF along the hair was monitored using enhanced-fluorescence video microscopy. Cytoplasmic streaming stopped in cells treated with CaBAPTA, indicating that intracellular Ca(2+) had increased. Cell-to-cell diffusion of CF was blocked in cells treated with Ca-BAPTA. An inhibition of cytoplasmic streaming and cell-to-cell diffusion was observed in the cells adjoining the CaBAPTA-microinjected cell, indicating that the Ca-BAPTA appeared to pass through plasmodesmata. While cytoplasmic streaming resumed 5-10 min after CaBAPTA treatment, cell-to-cell diffusion did not resume until 30-120 min later. These data support an involvement of calcium in the regulation of cell-to-cell communication in plants.

1. PARKING LOT BEFORE SOUTH ENTRANCE STATION, FACING N. PARK ...

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

1. PARKING LOT BEFORE SOUTH ENTRANCE STATION, FACING N. PARK ENTRANCE SIGN IS IN TREES IN CENTER. - South Entrance Road, Between South park boundary & Village Loop Road, Grand Canyon, Coconino County, AZ

Solubility and diffusivity of N{sub 2}O and CO{sub 2} in (diethanolamine + N-methyldiethanolamine + water) and in (diethanolamine + 2-amino-2-methyl-1-propanol + water)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, M.H.; Lee, W.C.

1996-05-01

Acid gases such as CO{sub 2} and H{sub 2}S are frequently removed from natural gas, synthetic natural gas, and other process gas streams by means of absorption into aqueous alkanol-amine solutions. The solubility and diffusivity of N{sub 2}O in (diethanolamine + N-methyldiethanolamine + water) and in (diethanolamine + 2-amino-2-methyl-1-propanol + water) were measured at (30, 35, and 40)C and at atmospheric pressure. Five (diethanolamine + N-methyldiethanolamine + water) and four (diethanolamine + 2-amino-2-methyl-1-propanol + water) systems were studied. The total amine mass percent in all cases was 30. A solubility apparatus was used to measure the solubility of N{sub 2}Omore » in amine solutions. The diffusivity was measured by a wetted wall column absorber. The N{sub 2}O analogy was used to estimate the solubility and diffusivity of CO{sub 2} in (diethanolamine + N-methyldiethanolamine + water) and in (diethanolamine + 2-amino-2-methyl-1-propanol + water).« less

Diffusion of Magnesium in Led Structures with InGaN/GaN Quantum Wells at True Growth Temperatures 860-980°C of p-GaN

NASA Astrophysics Data System (ADS)

Romanov, I. S.; Prudaev, I. A.; Brudnyi, V. N.

2018-05-01

The results of an investigation of Mg diffusion in blue LED structures with InGaN/GaN quantum wells are presented for various growth temperatures of the p-GaN layer. The values of the diffusion coefficient estimated for true growth temperatures of 860, 910, and 980°C were 7.5·10-17, 2.8·10-16, and 1.2·10-15 cm2/s, respectively. The temperature values given in the work were measured on the surface of the growing layer in situ using a pyrometer. The calculated activation energy for the temperature dependence of the diffusion coefficient was 2.8 eV.

Modified nondestructive colorimetric method to evaluate the variability of oxygen diffusion rate through wine bottle closures.

PubMed

Brotto, Laura; Battistutta, Franco; Tat, Lara; Comuzzo, Piergiorgio; Zironi, Roberto

2010-03-24

Some modifications to a previous nondestructive colorimetric method that permits evaluation of the oxygen diffusion rate through wine closures were proposed. The method is based on the reaction of indigo carmine solution with oxygen and the tristimulus measurement of the consequent color change. Simplified preparation and measurement procedures were set up, allowing the analysis of a large number of samples simultaneously. The method was applied to the evaluation of the variability within the lot of 20 different types of stoppers (synthetic, produced by molding, and natural cork). The closures were tested at a storage temperature of 26 degrees C. With regard to oxygen permeability, the natural cork stopper showed a low homogeneity within the lot, especially during the first month after bottling, whereas the synthetic closure showed a greater steadiness in the performance. The limits of the colorimetric method were also analyzed, and three possible causes of degradation of the indigo carmine solution were identified: oxygen, light, and heat.

Effects of composition of the micro porous layer and the substrate on performance in the electrochemical reduction of CO2 to CO

NASA Astrophysics Data System (ADS)

Kim, Byoungsu; Hillman, Febrian; Ariyoshi, Miho; Fujikawa, Shigenori; Kenis, Paul J. A.

2016-04-01

With the development of better catalysts, mass transport limitations are becoming a challenge to high throughput electrochemical reduction of CO2 to CO. In contrast to optimization of electrodes for fuel cells, optimization of gas diffusion electrodes (GDE) - consisting of a carbon fiber substrate (CFS), a micro porous layer (MPL), and a catalyst layer (CL) - for CO2 reduction has not received a lot of attention. Here, we studied the effect of the MPL and CFS composition on cathode performance in electroreduction of CO2 to CO. In a flow reactor, optimized GDEs exhibited a higher partial current density for CO production than Sigracet 35BC, a commercially available GDE. By performing electrochemical impedance spectroscopy in a CO2 flow reactor we determined that a loading of 20 wt% PTFE in the MPL resulted in the best performance. We also investigated the influence of the thickness and wet proof level of CFS with two different feeds, 100% CO2 and the mixture of 50% CO2 and N2, determining that thinner and lower wet proofing of the CFS yields better cathode performance than when using a thicker and higher wet proof level of CFS.

Communication: Diverse nanoscale cluster dynamics: Diffusion of 2D epitaxial clusters

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lai, King C.; Evans, James W.; Liu, Da -Jiang

The dynamics of nanoscale clusters can be distinct from macroscale behavior described by continuum formalisms. For diffusion of 2D clusters of N atoms in homoepitaxial systems mediated by edge atom hopping, macroscale theory predicts simple monotonic size scaling of the diffusion coefficient, D N ~ N –β, with β = 3/2. However, modeling for nanoclusters on metal(100) surfaces reveals that slow nucleation-mediated diffusion displaying weak size scaling β < 1 occurs for “perfect” sizes N p = L 2 and L(L+1) for integer L = 3,4,… (with unique square or near-square ground state shapes), and also for N p+3, Nmore » p+4,…. In contrast, fast facile nucleation-free diffusion displaying strong size scaling β ≈ 2.5 occurs for sizes N p+1 and N p+2. D N versus N oscillates strongly between the slowest branch (for N p+3) and the fastest branch (for N p+1). All branches merge for N = O(10 2), but macroscale behavior is only achieved for much larger N = O(10 3). Here, this analysis reveals the unprecedented diversity of behavior on the nanoscale.« less

Communication: Diverse nanoscale cluster dynamics: Diffusion of 2D epitaxial clusters

DOE PAGES

Lai, King C.; Evans, James W.; Liu, Da -Jiang

2017-11-27

The dynamics of nanoscale clusters can be distinct from macroscale behavior described by continuum formalisms. For diffusion of 2D clusters of N atoms in homoepitaxial systems mediated by edge atom hopping, macroscale theory predicts simple monotonic size scaling of the diffusion coefficient, D N ~ N –β, with β = 3/2. However, modeling for nanoclusters on metal(100) surfaces reveals that slow nucleation-mediated diffusion displaying weak size scaling β < 1 occurs for “perfect” sizes N p = L 2 and L(L+1) for integer L = 3,4,… (with unique square or near-square ground state shapes), and also for N p+3, Nmore » p+4,…. In contrast, fast facile nucleation-free diffusion displaying strong size scaling β ≈ 2.5 occurs for sizes N p+1 and N p+2. D N versus N oscillates strongly between the slowest branch (for N p+3) and the fastest branch (for N p+1). All branches merge for N = O(10 2), but macroscale behavior is only achieved for much larger N = O(10 3). Here, this analysis reveals the unprecedented diversity of behavior on the nanoscale.« less

VizieR Online Data Catalog: Circumgalactic medium surrounding z~2 quasars (Prochaska+, 2014)

NASA Astrophysics Data System (ADS)

Prochaska, J. X.; Lau, M. W.; Hennawi, J. F.

2017-08-01

The sample of quasar pairs analyzed here is a subset of the sample studied in QPQ6 (Cantalupo et al. 2014Natur.506...63C) for H I Lyα absorption. Specifically, we have restricted the current study to those pairs where the signal-to-noise ratio (S/N) at H I Lyα exceeds 9.5 per rest-frame Å. This facilitates a more precise evaluation of H I Lyα and generally insures sufficient S/N redward of Lyα for the metal-line analysis. Quasar emission redshifts are taken directly from QPQ6 (Cantalupo et al. 2014Natur.506...63C), following the methodology described in that manuscript. Briefly, we adopt a custom line-centering algorithm to centroid one or more far-UV emission lines and adopt the analysis of Shen et al. (2007, J/AJ/133/2222) to combine these measurements and assess systematic uncertainty in the final value. The median emission redshift of the 427 pairs is zemmedian=2.35 and the median uncertainty in the redshift measurements is ~520 km/s. The impact parameters range from R{perp}=39 kpc to 1 Mpc, with 52 pairs having R{perp}<200 kpc. (3 data files).

Comparison of surgically induced astigmatism following different glaucoma operations.

PubMed

Tanito, Masaki; Matsuzaki, Yukari; Ikeda, Yoshifumi; Fujihara, Etsuko

2017-01-01

To compare surgically induced astigmatism (SIA) among glaucomatous eyes treated with trabeculectomy (LEC), EX-PRESS ® shunt (EXP), ab externo trabeculotomy (exLOT), or microhook ab interno trabeculotomy (μLOT). Eighty right eyes of 80 subjects who underwent LEC (n=20), EXP (n=20), exLOT (n=20), or μLOT (n=20) were included. The dataset including the best-corrected visual acuity (BCVA), intraocular pressure (IOP), and keratometry recordings preoperatively and 3 months postoperatively was collected by chart review. The means of the vector magnitude, vector meridian, and arithmetic magnitude of the preoperative and postoperative astigmatism and SIA were calculated. The correlations among the SIA magnitude, postoperative BCVA, and IOP were assessed. The mean astigmatic arithmetic magnitudes did not differ significantly ( P =0.0732) preoperatively among the four groups, but the magnitude was significantly ( P =0.0002) greater in the LEC group than the other groups postoperatively. The mean SIA vectors were calculated to be 1.01 D at 56°, 0.62 D at 74°, 0.23 D at 112°, and 0.12 D at 97° for the LEC, EXP, exLOT, and μLOT groups, respectively. The mean SIA arithmetic magnitudes were significantly ( P <0.0001) greater in the LEC group than the other groups. Three months postoperatively, the SIA magnitude was correlated positively with the logarithm of the minimum angle of resolution (logMAR) BCVA ( r =0.3538) and negatively with the IOP ( r =-0.3265); the logMAR BCVA was correlated negatively with the IOP ( r =-0.3105). EXP, exLOT, and μLOT induce less corneal astigmatism than LEC in the early postoperative period.

Comparison of surgically induced astigmatism following different glaucoma operations

PubMed Central

Tanito, Masaki; Matsuzaki, Yukari; Ikeda, Yoshifumi; Fujihara, Etsuko

2017-01-01

Aim To compare surgically induced astigmatism (SIA) among glaucomatous eyes treated with trabeculectomy (LEC), EX-PRESS® shunt (EXP), ab externo trabeculotomy (exLOT), or microhook ab interno trabeculotomy (μLOT). Subjects and methods Eighty right eyes of 80 subjects who underwent LEC (n=20), EXP (n=20), exLOT (n=20), or μLOT (n=20) were included. The dataset including the best-corrected visual acuity (BCVA), intraocular pressure (IOP), and keratometry recordings preoperatively and 3 months postoperatively was collected by chart review. The means of the vector magnitude, vector meridian, and arithmetic magnitude of the preoperative and postoperative astigmatism and SIA were calculated. The correlations among the SIA magnitude, postoperative BCVA, and IOP were assessed. Results The mean astigmatic arithmetic magnitudes did not differ significantly (P=0.0732) preoperatively among the four groups, but the magnitude was significantly (P=0.0002) greater in the LEC group than the other groups postoperatively. The mean SIA vectors were calculated to be 1.01 D at 56°, 0.62 D at 74°, 0.23 D at 112°, and 0.12 D at 97° for the LEC, EXP, exLOT, and μLOT groups, respectively. The mean SIA arithmetic magnitudes were significantly (P<0.0001) greater in the LEC group than the other groups. Three months postoperatively, the SIA magnitude was correlated positively with the logarithm of the minimum angle of resolution (logMAR) BCVA (r=0.3538) and negatively with the IOP (r=−0.3265); the logMAR BCVA was correlated negatively with the IOP (r=−0.3105). Conclusion EXP, exLOT, and μLOT induce less corneal astigmatism than LEC in the early postoperative period. PMID:29238159

Mode of Action of Membrane Perturbing Agents: Snake Venom Cardiotoxins and Phospholipases A

DTIC Science & Technology

1989-07-15

PLAz neurotoxins. Experimental Methods: Materials. Vencm from 1 nAjA atra, CTX from Naja n9ja kaouthia venom (Lots 125F-4007), bee venom PLAz ( Apis ... mellifera ), melittin, B-bungarotoxin, Tris base, Hepes (4-(2-hydroxyethyl)-l-piperazineethanesulfonic acid), Mes (4- morpholineethanesulfonic acid), bovine

Nutrient concentrations in leachate and runoff from dairy cattle lots with different surface materials

USDA-ARS?s Scientific Manuscript database

Nitrogen (N) and phosphorus (P) loss from agriculture persists as a water quality issue, and outdoor cattle lots can have a high loss potential. We monitored hydrology and nutrient concentrations in leachate and runoff from dairy heifer lots constructed with three surface materials (soil, sand, bark...

A facile method for synthesis of graphene-coated hexagonal ZnO photocatalyst with enhanced photodegradation activity

NASA Astrophysics Data System (ADS)

Zhang, Yunlong; Zhang, Yuzhi

2017-12-01

A kind of hexagonal ZnO (HZO) was synthesized in N-methyl-2-pyrrolidone (NMP)/H2O mixed solvent for a high exposure of polar ±(0001) facets to get a high-efficiency photocatalyst. The amine-functionalized HZO particles were coated with graphene oxide (GO) by electrostatic force-induced self-assemby and thermal reduction to form HZO@Gr core/shell structure. The as-prepared HZO and HZO@Gr were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Raman spectroscopy and UV-visible diffuse reflectance spectroscopy (UV-vis/DRS). The results indicate that the graphene on HZO@Gr remains high quality and the optical properties of the composite change a lot with sunlight absorption improving, bandgap and photoluminescence (PL) intensity decreasing. The obtained HZO photocatalyst shows good photocatalytic activity for methylene blue (MB) under UV-visible irradiation. Furthermore, the HZO@Gr photocatalyst exhibits the best photodegradation rate of MB reaching up to 98.2% within 50 minutes. The graphene-coated HZO structure could offer new directions which would further extend the scope for synthesis of various ZnO/graphene composites with improved properties useful for various applications.

Heat capacities and thermal diffusivities of n-alkane acid ethyl esters—biodiesel fuel components

NASA Astrophysics Data System (ADS)

Bogatishcheva, N. S.; Faizullin, M. Z.; Nikitin, E. D.

2017-09-01

The heat capacities and thermal diffusivities of ethyl esters of liquid n-alkane acids C n H2 n-1O2C2H5 with the number of carbon atoms in the parent acid n = 10, 11, 12, 14, and 16 are measured. The heat capacities are measured using a DSC 204 F1 Phoenix heat flux differential scanning calorimeter (Netzsch, Germany) in the temperature range of 305-375 K. Thermal diffusivities are measured by means of laser flash method on an LFA-457 instrument (Netzsch, Germany) at temperatures of 305-400 K. An equation is derived for the dependence of the molar heat capacities of the investigated esters on temperature. It is shown that the dependence of molar heat capacity C p,m (298.15 K) on n ( n = 1-6) is close to linear. The dependence of thermal diffusivity on temperature in the investigated temperature range is described by a first-degree polynomial, but thermal diffusivity a (298.15 K) as a function of n has a minimum at n = 5.

Diffusion in thoriated and nonthoriated nickel and nickel-chromium alloys at 1260 C

NASA Technical Reports Server (NTRS)

Whittenberger, J. D.

1972-01-01

Various solid-solid diffusion couples were assembled from thoriated and nonthoriated nickel-base alloys, welded, and diffusion annealed at 1260 C. Concentration profiles indicated that a thoria dispersion does not affect diffusion in Cr(alloy):Ni and Ni-4.8Al:Ni types of couples unless a fine grain structure is retained by the thoria particles. Metallography revealed the presence of thoria-free bands in the thoriated-Ni side of the diffusion zone. The bands contained grain boundaries and, in some cases, non-Kirkendall porosity. A mechanism based on the operation of vacancy sources is proposed to explain the thoria-free bands. In addition, a particular DS-NiCr:Ni couple had negligible Kirkendall porosity. This behavior was related to the grain structure of the particular lot of DS-NiCr.

Diffusion of Magnesium in Led Structures with InGaN/GaN Quantum Wells at True Growth Temperatures 860–980°C of p-GaN

NASA Astrophysics Data System (ADS)

Romanov, I. S.; Prudaev, I. A.; Brudnyi, V. N.

2018-05-01

The results of an investigation of Mg diffusion in blue LED structures with InGaN/GaN quantum wells are presented for various growth temperatures of the p-GaN layer. The values of the diffusion coefficient estimated for true growth temperatures of 860, 910, and 980°C were 7.5·10-17, 2.8·10-16, and 1.2·10-15 cm2/s, respectively. The temperature values given in the work were measured on the surface of the growing layer in situ using a pyrometer. The calculated activation energy for the temperature dependence of the diffusion coefficient was 2.8 eV.

"Thinking a Lot" Among the Khwe of South Africa: A Key Idiom of Personal and Interpersonal Distress.

PubMed

den Hertog, T N; de Jong, M; van der Ham, A J; Hinton, D; Reis, R

2016-09-01

"Thinking too much", and variations such as "thinking a lot", are common idioms of distress across the world. The contextual meaning of this idiom of distress in particular localities remains largely unknown. This paper reports on a systematic study of the content and cause, consequences, and social response and coping related to the local terms |x'an n|a te and |eu-ca n|a te, both translated as "thinking a lot", and was part of a larger ethnographic study among the Khwe of South Africa. Semi-structured exploratory interviews with community members revealed that "thinking a lot" refers to a common experience of reflecting on personal and interpersonal problems. Consequences were described in emotional, psychological, social, behavioral, and physical effects. Coping strategies included social support, distraction, and religious practices. Our contextualized approach revealed meanings and experiences of "thinking a lot" that go beyond a psychological state or psychopathology. The common experience of "thinking a lot" is situated in socio-political, economic, and social context that reflect the marginalized and displaced position of the Khwe. We argue that "thinking a lot" and associated local meanings may vary across settings, may not necessarily indicate psychopathology, and should be understood in individual, interpersonal, community, and socio-political dimensions.

Ammonia losses and nitrogen partitioning at the southern High Plains open lot dairy

USDA-ARS?s Scientific Manuscript database

Animal agriculture is a significant source of ammonia (NH3). Cattle excrete most ingested nitrogen (N); most urinary N is converted to NH3, volatilized and lost to the atmosphere. Open lot dairies on the southern High Plains are a growing industry and face environmental challenges as well as reporti...

Effect of Organic Substrates on the Photocatalytic Reduction of Cr(VI) by Porous Hollow Ga2O3 Nanoparticles

PubMed Central

Liu, Jin; Gan, Huihui; Wu, Hongzhang; Zhang, Xinlei; Zhang, Jun; Li, Lili; Wang, Zhenling

2018-01-01

Porous hollow Ga2O3 nanoparticles were successfully synthesized by a hydrolysis method followed by calcination. The prepared samples were characterized by field emission scanning electron microscope, transmission electron microscope, thermogravimetry and differential scanning calorimetry, UV-vis diffuse reflectance spectra and Raman spectrum. The porous structure of Ga2O3 nanoparticles can enhance the light harvesting efficiency, and provide lots of channels for the diffusion of Cr(VI) and Cr(III). Photocatalytic reduction of Cr(VI), with different initial pH and degradation of several organic substrates by porous hollow Ga2O3 nanoparticles in single system and binary system, were investigated in detail. The reduction rate of Cr(VI) in the binary pollutant system is markedly faster than that in the single Cr(VI) system, because Cr(VI) mainly acts as photogenerated electron acceptor. In addition, the type and concentration of organic substrates have an important role in the photocatalytic reduction of Cr(VI). PMID:29690548

Correlation of rates of tritium migration through porous concrete

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fukada, S.; Katayama, K.; Takeishi, T.

In a nuclear facility when tritium leaks from a glovebox to room accidentally, an atmosphere detritiation system (ADS) starts operating, and HTO released is recovered by ADS. ADS starts when tritium activity in air becomes higher than its controlled level. Before ADS operates, the laboratory walls are the final enclosure facing tritium and are usually made of porous concrete coated with a hydrophobic paint. In the present study, previous data on the diffusivity and adsorption coefficient of concrete and paints are reviewed. Tritium penetrates and migrates into concrete by following 3 ways. First, gaseous HT or T{sub 2} easily penetratesmore » into porous concrete. Its diffusivity is almost equal to that of H{sub 2}. When a gaseous molecule diffuses through pores with a smaller diameter than a mean free path, its migration rate is described by the Knudsen diffusion formula. The second mechanism is H{sub 2}O vapor diffusion in pores. Concrete holds a lot of structural water. Therefore, H{sub 2}O or HTO vapor can diffuse inside concrete pores along with adsorption-desorption and isotopic exchange with structural water, which is the third mechanism. Literature shows that the diffusivity of HTO through the epoxy-resin paint is determined as D(HTO)=1.0*10{sup -16} m{sup 2}/s. We have used this data to set a model and we have applied it to estimate residual tritium in laboratory walls. We have considered 2 accidental cases and a normal case: first, ADS starts operating 1 hour after 100 Ci HTO is released in the room, secondly, ADS starts 24 hours after 100 Ci HTO release and thirdly, when the walls are exposed to HTO for 10 years of normal operation. It appears that the immediate start up of ADS is indispensable for safety.« less

Modeling of Diffusivity for 2D Vacancy Nanopits and Comparison with 2D Adatom Nanoislands on Metal(100) Surfaces Including Analysis for Ag(100)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lai, King C.; Liu, Da-Jiang; Thiel, Patricia A.

Diffusion coefficients, D N, for 2D vacancy nanopits are compared with those for 2D homoepitaxial adatom nanoislands on metal(100) surfaces, focusing on the variation of DN with size, N. Here, N is measured in missing atoms for pits and adatoms for islands. Analysis of D N is based on kinetic Monte Carlo simulations of a tailored stochastic lattice-gas model, where pit and island diffusion are mediated by periphery diffusion, i.e., by edge atom hopping. Precise determination of D N versus N for typical parameters reveals a cyclical variation with an overall decrease in magnitude for increasing moderate O(10 2) ≤more » N ≤ O(10 3). Monotonic decay, D N~ N -β, is found for N ≥ O(10 2) with effective exponents, β = β eff, for both pits and islands, both well below the macroscopic value of βmacro = 3/2. D N values for vacancy pits are significantly lower (higher) than for adatom islands for moderate N in the case of low (high) kink rounding barrier. However, D N values for pits and islands slowly merge, and β eff → 3/2 for sufficiently large N. The latter feature is expected from continuum Langevin formulations appropriate for large sizes. Finally, we compare predictions from our model incorporating appropriate energetic parameters for Ag(100) with different sets of experimental data for diffusivity at 300 K, including assessment of β eff, for experimentally observed sizes N from ~100 to ~1000.« less

Modeling of Diffusivity for 2D Vacancy Nanopits and Comparison with 2D Adatom Nanoislands on Metal(100) Surfaces Including Analysis for Ag(100)

DOE PAGES

Lai, King C.; Liu, Da-Jiang; Thiel, Patricia A.; ...

2018-02-22

Diffusion coefficients, D N, for 2D vacancy nanopits are compared with those for 2D homoepitaxial adatom nanoislands on metal(100) surfaces, focusing on the variation of DN with size, N. Here, N is measured in missing atoms for pits and adatoms for islands. Analysis of D N is based on kinetic Monte Carlo simulations of a tailored stochastic lattice-gas model, where pit and island diffusion are mediated by periphery diffusion, i.e., by edge atom hopping. Precise determination of D N versus N for typical parameters reveals a cyclical variation with an overall decrease in magnitude for increasing moderate O(10 2) ≤more » N ≤ O(10 3). Monotonic decay, D N~ N -β, is found for N ≥ O(10 2) with effective exponents, β = β eff, for both pits and islands, both well below the macroscopic value of βmacro = 3/2. D N values for vacancy pits are significantly lower (higher) than for adatom islands for moderate N in the case of low (high) kink rounding barrier. However, D N values for pits and islands slowly merge, and β eff → 3/2 for sufficiently large N. The latter feature is expected from continuum Langevin formulations appropriate for large sizes. Finally, we compare predictions from our model incorporating appropriate energetic parameters for Ag(100) with different sets of experimental data for diffusivity at 300 K, including assessment of β eff, for experimentally observed sizes N from ~100 to ~1000.« less

Experimental and theoretical studies of the products of addition-elimination reactions between benzil dihydrazone and three isomeric chlorobenzaldehydes.

PubMed

Liu, Yun-Na; Cheng, Shuang-Shuang; Wang, Chao; Xing, Dian-Xiang; Liu, Yun; Tan, Xue-Jie

2015-07-01

A series of mono- and di-Schiff bases formed between benzil dihydrazone {BDH; systematic name: (1Z)-[(2E)-2-hydrazinylidene-1,2-diphenylethylidene]hydrazine} and three isomeric chlorobenzaldehydes were designed and synthesized to be used as model compounds to help to explain the reaction mechanisms for the formation of Schiff bases. These compounds are 1-(2-chlorobenzylidene)-2-{2-[2-(2-chlorobenzylidene)hydrazin-1-ylidene]-1,2-diphenylethylidene}hydrazine (BDHOCB), and the 3-chloro (BDHMCB) and 4-chloro (BDHPCB) analogues, all having the formula C28H20Cl2N4. Surprisingly, only di-Schiff bases were obtained; our attempts to push the reaction in favour of the mono-Schiff bases all failed. Density functional theory (DFT) calculations were performed to explain the trend in the experimental results. In the case of the systems studied, the type of Schiff base produced exhibits a clear dependence on the HOMO-LUMO energy gaps (ΔE(HOMO-LUMO)), i.e. the product is mainly governed by its stability. The compounds were characterized by single-crystal X-ray diffractometry, elemental analysis, melting point, (1)H NMR and (13)C NMR spectroscopy. The structural features of the three new Schiff bases are similar. For instance, they have the same chemical formula, all the molecules have a symmetrical double helix structure, with each Ph-C=N-N=C-Ph arm exhibiting an anti conformation, and their supramolecular interactions include intermolecular π-π and weak C-H...π stacking interactions. The crystal systems are different, however, viz. triclinic (space group P1¯) for BDHPCB, monoclinic (space group P2(1)/n) for BDHOCB and orthorhombic (space group Pnna) for BDHMCB.

Diffusion of two-dimensional epitaxial clusters on metal (100) surfaces: Facile versus nucleation-mediated behavior and their merging for larger sizes

NASA Astrophysics Data System (ADS)

Lai, King C.; Liu, Da-Jiang; Evans, James W.

2017-12-01

For diffusion of two-dimensional homoepitaxial clusters of N atoms on metal (100) surfaces mediated by edge atom hopping, macroscale continuum theory suggests that the diffusion coefficient scales like DN˜ N-β with β =3 /2 . However, we find quite different and diverse behavior in multiple size regimes. These include: (i) facile diffusion for small sizes N <9 ; (ii) slow nucleation-mediated diffusion with small β <1 for "perfect" sizes N = Np= L2 or L (L +1 ) , for L =3 ,4 , ... having unique ground-state shapes, for moderate sizes 9 ≤N ≤O (102) ; the same also applies for N =Np+3 , Np+ 4 , ... (iii) facile diffusion but with large β >2 for N =Np+1 and Np+2 also for moderate sizes 9 ≤N ≤O (102) ; (iv) merging of the above distinct branches and subsequent anomalous scaling with 1 ≲β <3 /2 , reflecting the quasifacetted structure of clusters, for larger N =O (102) to N =O (103) ; (v) classic scaling with β =3 /2 for very large N =O (103) and above. The specified size ranges apply for typical model parameters. We focus on the moderate size regime where we show that diffusivity cycles quasiperiodically from the slowest branch for Np+3 (not Np) to the fastest branch for Np+1 . Behavior is quantified by kinetic Monte Carlo simulation of an appropriate stochastic lattice-gas model. However, precise analysis must account for a strong enhancement of diffusivity for short time increments due to back correlation in the cluster motion. Further understanding of this enhancement, of anomalous size scaling behavior, and of the merging of various branches, is facilitated by combinatorial analysis of the number of the ground-state and low-lying excited state cluster configurations, and also of kink populations.

Major diffusion leaks of clamp-on leaf cuvettes still unaccounted: how erroneous are the estimates of Farquhar et al. model parameters?

PubMed

Rodeghiero, Mirco; Niinemets, Ulo; Cescatti, Alessandro

2007-08-01

Estimates of leaf gas-exchange characteristics using standard clamp-on leaf chambers are prone to errors because of diffusion leaks. While some consideration has been given to CO(2) diffusion leaks, potential water vapour diffusion leaks through chamber gaskets have been neglected. We estimated diffusion leaks of two clamp-on Li-Cor LI-6400 (Li-Cor, Inc., Lincoln, NE, USA) leaf chambers with polymer foam gaskets and enclosing either 2 or 6 cm(2) leaf area, and conducted a sensitivity analysis of the diffusion leak effects on Farquhar et al. photosynthesis model parameters - the maximum carboxylase activity of ribulose 1 x 5-bisphosphate carboxylase/oxygenase (Rubisco) (V(cmax)), capacity for photosynthetic electron transport (J(max)) and non-photorespiratory respiration rate in light (R(d)). In addition, net assimilation rate (A(n)) versus intercellular CO(2) (C(i)) responses were measured in leaves of Mediterranean evergreen species Quercus ilex L. enclosing the whole leaf chamber in a polyvinyl fluoride bag flushed with the exhaust air of leaf chamber, thereby effectively reducing the CO(2) and water vapour gradients between ambient air and leaf chamber. For the empty chambers, average diffusion leak for CO(2), K(CO2), (molar flow rate corresponding to unit CO(2) mole fraction difference) was ca. 0.40 micromol s(-1). K(CO2) increased ca. 50% if a dead leaf was clamped between the leaf chamber. Average diffusion leak for H(2)O was ca. 5- to 10-fold larger than the diffusion leak for CO(2). Sensitivity analyses demonstrated that the consequence of a CO(2) diffusion leak was apparent enhancement of A(n) at high CO(2) mole fraction and reduction at lower CO(2) mole fraction, and overall compression of C(i) range. As the result of these modifications, Farquhar et al. model parameters were overestimated. The degree of overestimation increased in the order of V(cmax) < J(max) < R(d), and was larger for smaller chambers and for leaves with lower photosynthetic capacity, leading to overestimation of all three parameters by 70-290% for 2 cm(2), and by 10-60% for 6 cm(2) chamber. Significant diffusion corrections (5-36%) were even required for leaves with high photosynthetic capacity measured in largest chamber. Water vapour diffusion leaks further enhanced the overestimation of model parameters. For small chambers and low photosynthetic capacities, apparent C(i) was simulated to decrease with increasing A(n) because of simultaneous CO(2) and H(2)O diffusion leaks. Measurements in low photosynthetic capacity Quercus ilex leaves enclosed in 2 cm(2) leaf chamber exhibited negative apparent C(i) values at highest A(n). For the same leaves measured with the entire leaf chamber enclosed in the polyvinyl fluoride bag, C(i) and A(n) increased monotonically. While the measurements without the bag could be corrected for diffusion leaks, the required correction in A(n) and transpiration rates was 100-500%, and there was large uncertainty in Farquhar et al. model parameters derived from 'corrected'A(n)/C(i) response curves because of uncertainties in true diffusion leaks. These data demonstrate that both CO(2) and water vapour diffusion leaks need consideration in measurements with clamp-on leaf cuvettes. As plants in natural environments are often characterized by low photosynthetic capacities, cuvette designs need to be improved for reliable measurements in such species.

26 CFR 1.199-9 - Application of section 199 to pass-thru entities for taxable years beginning on or before May 17...

Code of Federal Regulations, 2014 CFR

2014-04-01

... the trust's or estate's distributable net income (DNI), as defined by section 643(a), for the taxable... the gross receipts from PRS ($20,000), resulting in net income from PRS of $10,000. With respect to... attributed to tax-exempt interest is $2,222 ($8,000 × ($10,000 tax exempt interest/$36,000 gross receipts net...

26 CFR 1.199-9 - Application of section 199 to pass-thru entities for taxable years beginning on or before May 17...

Code of Federal Regulations, 2013 CFR

2013-04-01

... the trust's or estate's distributable net income (DNI), as defined by section 643(a), for the taxable... the gross receipts from PRS ($20,000), resulting in net income from PRS of $10,000. With respect to... attributed to tax-exempt interest is $2,222 ($8,000 × ($10,000 tax exempt interest/$36,000 gross receipts net...

26 CFR 1.199-9 - Application of section 199 to pass-thru entities for taxable years beginning on or before May 17...

Code of Federal Regulations, 2011 CFR

2011-04-01

... the trust's or estate's distributable net income (DNI), as defined by section 643(a), for the taxable... the gross receipts from PRS ($20,000), resulting in net income from PRS of $10,000. With respect to... attributed to tax-exempt interest is $2,222 ($8,000 × ($10,000 tax exempt interest/$36,000 gross receipts net...

Solubility and diffusivity of N{sub 2}O and CO{sub 2} in (monoethanolamine + N-methyldiethanolamine + water) and in (monoethanolamine + 2-amino-2-methyl-1-propanol + water)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, M.H.; Lai, M.D.

1995-03-01

Solutions of amines are frequently used in gas-treating processes to remove acid gases, such as CO{sub 2} and H{sub 2}S, from gas streams in the natural gas and synthetic ammonia industries and petroleum chemical plants. The solubility and diffusivity of N{sub 2}O in (monoethanolamine + N-methyldiethanolamine + water) and in (monoethanolamine + 2-amino-2-methyl-l-propanol + water) were measured at 30, 35, and 40 C and at atmospheric pressure. Six (monoethanolamine + N-methyldiethanolamine + water) and five (monoethanolamine + 2-amino-2-methyl-l-propanol + water) systems were studied. The total amine mass percent in all cases was 30. The solubilities were measured by a solubilitymore » apparatus similar to that of Haimour and Sandall (1984). A wetted wall column absorber was used to obtain the diffusivity of N{sub 2}O in amines. The N{sub 2}O solubilities in amine solutions have been correlated on the basis of the excess Henry constant correlation of Wang et al. (1992). The N{sub 2}O analogy was used to estimate the solubility and diffusivity of CO{sub 2} in (monoethanolamine + N-methyldiethanolamine + water) and in (monoethanolamine + 2-amino-2-methyl-l-propanol + water).« less

NMR relaxometric probing of ionic liquid dynamics and diffusion under mesoscopic confinement within bacterial cellulose ionogels

NASA Astrophysics Data System (ADS)

Smith, Chip J.; Gehrke, Sascha; Hollóczki, Oldamur; Wagle, Durgesh V.; Heitz, Mark P.; Baker, Gary A.

2018-05-01

Bacterial cellulose ionogels (BCIGs) represent a new class of material comprising a significant content of entrapped ionic liquid (IL) within a porous network formed from crystalline cellulose microfibrils. BCIGs suggest unique opportunities in separations, optically active materials, solid electrolytes, and drug delivery due to the fact that they can contain as much as 99% of an IL phase by weight, coupled with an inherent flexibility, high optical transparency, and the ability to control ionogel cross-sectional shape and size. To allow for the tailoring of BCIGs for a multitude of applications, it is necessary to better understand the underlying principles of the mesoscopic confinement within these ionogels. Toward this, we present a study of the structural, relaxation, and diffusional properties of the ILs, 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([emim][Tf2N]) and 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide ([bmpy][Tf2N]), using 1H and 19F NMR T1 relaxation times, rotational correlation times, and diffusion ordered spectroscopy (DOSY) diffusion coefficients, accompanied by molecular dynamics (MD) simulations. We observed that the cation methyl groups in both ILs were primary points of interaction with the cellulose chains and, while the pore size in cellulose is rather large, [emim]+ diffusion was slowed by ˜2-fold, whereas [Tf2N]- diffusion was unencumbered by incorporation in the ionogel. While MD simulations of [bmpy][Tf2N] confinement at the interface showed a diffusion coefficient decrease roughly 3-fold compared to the bulk liquid, DOSY measurements did not reveal any significant changes in diffusion. This suggests that the [bmpy][Tf2N] alkyl chains dominate diffusion through formation of apolar domains. This is in contrast to [emim][Tf2N] where delocalized charge appears to preclude apolar domain formation, allowing interfacial effects to be manifested at a longer range in [emim][Tf2N].

Influence of Liquid Structure on Fickian Diffusion in Binary Mixtures of n-Hexane and Carbon Dioxide Probed by Dynamic Light Scattering, Raman Spectroscopy, and Molecular Dynamics Simulations.

PubMed

Klein, Tobias; Wu, Wenchang; Rausch, Michael Heinrich; Giraudet, Cédric; Koller, Thomas M; Fröba, Andreas Paul

2018-06-11

This study contributes to a fundamental understanding how the liquid structure in a model system consisting of weakly associative n-hexane ( n-C 6 H 14 ) and carbon dioxide (CO 2 ) influences the Fickian diffusion process. For this, the benefits of light scattering experiments and molecular dynamics (MD) simulations at macroscopic thermodynamic equilibrium were combined synergistically. Our reference Fickian diffusivities measured by dynamic light scattering (DLS) revealed an unusual trend with increasing CO 2 mole fractions up to a CO 2 concentration of about 70 mol%, which agrees with our simulation results. The molecular impacts on the Fickian diffusion were analyzed by MD simulations, where kinetic contributions related to the Maxwell-Stefan (MS) diffusivity and structural contributions quantified by the thermodynamic factor were studied separately. Both the MS diffusivity and the thermodynamic factor indicate the deceleration of Fickian diffusion compared to an ideal mixture behavior. Computed radial distribution functions as well as a significant blue-shift of the CH-stretching modes of n-C 6 H 14 identified by Raman spectroscopy show that the slowing-down of the diffusion is caused by a structural organization in the binary mixtures over a broad concentration range in the form of self-associated n-C 6 H 14 and CO 2 domains. These networks start to form close to the infinite dilution limits and seem to have their largest extent at a solute-solvent transition point at about 70 mol% of CO 2 . The current results not only improve the general understanding of mass diffusion in liquids, but also serve to develop sound prediction models for Fick diffusivities.

Coal-Tar-Based Parking Lot Sealcoat: An Unrecognized Source of PAH to Settled House Dust

PubMed Central

2010-01-01

Despite much speculation, the principal factors controlling concentrations of polycyclic aromatic hydrocarbons (PAH) in settled house dust (SHD) have not yet been identified. In response to recent reports that dust from pavement with coal-tar-based sealcoat contains extremely high concentrations of PAH, we measured PAH in SHD from 23 apartments and in dust from their associated parking lots, one-half of which had coal-tar-based sealcoat (CT). The median concentration of total PAH (T-PAH) in dust from CT parking lots (4760 μg/g, n = 11) was 530 times higher than that from parking lots with other pavement surface types (asphalt-based sealcoat, unsealed asphalt, concrete [median 9.0 μg/g, n = 12]). T-PAH in SHD from apartments with CT parking lots (median 129 μg/g) was 25 times higher than that in SHD from apartments with parking lots with other pavement surface types (median 5.1 μg/g). Presence or absence of CT on a parking lot explained 48% of the variance in log-transformed T-PAH in SHD. Urban land-use intensity near the residence also had a significant but weaker relation to T-PAH. No other variables tested, including carpeting, frequency of vacuuming, and indoor burning, were significant. PMID:20063893

Coal-tar-based parking lot sealcoat: An unrecognized source of PAH to settled house dust

USGS Publications Warehouse

Mahler, B.J.; Van Metre, P.C.; Wilson, J.T.; Musgrove, M.; Burbank, T.L.; Ennis, T.E.; Bashara, T.J.

2010-01-01

Despite much speculation, the principal factors controlling concentrations of polycyclic aromatic hydrocarbons (PAH) in settled house dust (SHD) have not yet been identified. In response to recent reports that dust from pavement with coaltar-based sealcoat contains extremely high concentrations of PAH, we measured PAH in SHD from 23 apartments and in dust from their associated parking lots, one-half of which had coal-tar-based sealcoat (CT). The median concentration of total PAH (T-PAH) in dust from CT parking lots (4760 ??g/g, n = 11) was 530 times higher than that from parking lots with other pavement surface types (asphalt-based sealcoat, unsealed asphalt, concrete [median 9.0 ??g/g, n = 12]). T-PAH in SHD from apartments with CT parking lots (median 129 ??g/g) was 25 times higher than that in SHD from apartments with parking lots with other pavement surface types (median 5.1 ??g/g). Presence or absence of CT on a parking lot explained 48% of the variance in log-transformed T-PAH in SHD. Urban land-use intensity near the residence also had a significant but weaker relation to T-PAH. No other variables tested, including carpeting, frequency of vacuuming, and indoor burning, were significant. ?? 2010 American Chemical Society.

Diffusion behavior of Cu/Ta heterogeneous interface under high temperature and high strain: An atomistic investigation

NASA Astrophysics Data System (ADS)

Li, Ganglong; Wu, Houya; Luo, Honglong; Chen, Zhuo; Tay, Andrew A. O.; Zhu, Wenhui

2017-09-01

Three-dimensional (3D) integration technology using Cu interconnections has emerged as a promising solution to improve the performance of silicon microelectronic devices. However, Cu diffuses into SiO2 and requires a barrier layer such as Ta to ensure acceptable reliability. In this paper, the effects of temperature and strain normal to the interface on the inter-diffusion of Cu and Ta at annealing conditions are investigated using a molecular dynamics (MD) technique with embedded atomic method (EAM) potentials. Under thermal annealing conditions without strain, it is found that a Cu-rich diffusion region approximately 2 nm thick is formed at 1000 K after 10 ns of annealing. Ta is capable of diffusing into the interior of Cu but Cu hardly diffuses into the inner lattice of Ta. At the Cu side near the interface an amorphous structure is formed due to the process of diffusion. The diffusion activation energy of Cu and Ta are found to be 0.9769 and 0.586 eV, respectively. However, when a strain is applied, a large number of crystal defects are generated in the sample. As the strain is increased, extrinsic stacking faults (ESFs) and lots of Shockley partial dislocations appear. The density of the dislocations and the diffusion channels increase, promoting the diffusion of Cu atoms into the inner lattice of Ta. The thickness of the diffusion layer increases to 4 times the value when only a temperature load of 700 K is applied. The MD simulations demonstrated that Ta is very effective as a barrier layer under thermal loading only, and its effectiveness is impaired by tensile strain at the Cu/Ta interface. The simulations also clarified the mechanism that caused the impairment. The methodology and approach described in this paper can be followed further to study the effectiveness of barrier layers under various annealing and strain conditions, and to determine the minimum thickness of barrier layers required for a particular application.

Molecular dynamic simulations of selective self-diffusion of CH4/CO2/H2O/N2 in coal

NASA Astrophysics Data System (ADS)

Song, Y.; Jiang, B.; Li, F. L.

2017-06-01

The self-diffusion coefficients (D) of CH4/CO2/H2O/N2 at a relatively broad range of temperatures(298.15∼ 458.15K)and pressures (1∼6MPa) under the NPT, NPH, NVE, and NVT ensembles were obtained after the calculations of molecular mechanics(MM), annealing kinetics(AK), giant canonical Monte Carlo(GCMC), and molecular dynamics (MD) based on Wiser bituminous coal model (WM). The Ds of the adsorbates at the saturated adsorption configurations are D CH4418K. The average swelling ratios manifest as H2O (14.7∼35.18%)>CO2 (13.38∼32.25%)>CH4 (15.35∼23.71%)> N2 (11.47∼22.14%) (NPH, 1∼6MPa). There exits differences in D, swelling ratios and E among various ensembles, indicating that the selection of ensembles has an important influence on the MD calculations for self-diffusion coefficients.

Determination of axial and lateral exciton diffusion length in GaN by electron energy dependent cathodoluminescence

NASA Astrophysics Data System (ADS)

Hocker, Matthias; Maier, Pascal; Jerg, Lisa; Tischer, Ingo; Neusser, Gregor; Kranz, Christine; Pristovsek, Markus; Humphreys, Colin J.; Leute, Robert A. R.; Heinz, Dominik; Rettig, Oliver; Scholz, Ferdinand; Thonke, Klaus

2016-08-01

We demonstrate the application of low-temperature cathodoluminescence (CL) with high lateral, depth, and spectral resolution to determine both the lateral (i.e., perpendicular to the incident primary electron beam) and axial (i.e., parallel to the electron beam) diffusion length of excitons in semiconductor materials. The lateral diffusion length in GaN is investigated by the decrease of the GaN-related luminescence signal when approaching an interface to Ga(In)N based quantum well stripes. The axial diffusion length in GaN is evaluated from a comparison of the results of depth-resolved CL spectroscopy (DRCLS) measurements with predictions from Monte Carlo simulations on the size and shape of the excitation volume. The lateral diffusion length was found to be (95 ± 40) nm for nominally undoped GaN, and the axial exciton diffusion length was determined to be (150 ± 25) nm. The application of the DRCLS method is also presented on a semipolar (11 2 ¯ 2 ) sample, resulting in a value of (70 ± 10) nm in p-type GaN.

Evaluation of advanced bladder technology

NASA Technical Reports Server (NTRS)

Christensen, M. V.; Pasternak, R. A.

1972-01-01

Research conducted during this period is reported. Studies presented include: (1) diffusion and permeation of CO2, O2, N2, and NO2 through polytetra fluoroethylene; (2) diffusion, permeation and solubility of simple gases (CO2, O2, N2, CH4, C2H6, C3H8, and C2H4) through a copolymer of hexafluoro propylene and tetrafluoro ethylene (FEP); (3) viscous flow and diffusion of gases throug small apertures; (4) diffusion and permeation of O2, N2, CO2, CH4, C2H6, and C3H8 through nitroso rubber; and (5) results of gas transport studies with carborane siloxane, nitroso rubber, silicone membrane, krytox coating on teflon, and FEP coated glass cloth. Publications generated under this program are listed.

System-size corrections for self-diffusion coefficients calculated from molecular dynamics simulations: The case of CO2, n-alkanes, and poly(ethylene glycol) dimethyl ethers

NASA Astrophysics Data System (ADS)

Moultos, Othonas A.; Zhang, Yong; Tsimpanogiannis, Ioannis N.; Economou, Ioannis G.; Maginn, Edward J.

2016-08-01

Molecular dynamics simulations were carried out to study the self-diffusion coefficients of CO2, methane, propane, n-hexane, n-hexadecane, and various poly(ethylene glycol) dimethyl ethers (glymes in short, CH3O-(CH2CH2O)n-CH3 with n = 1, 2, 3, and 4, labeled as G1, G2, G3, and G4, respectively) at different conditions. Various system sizes were examined. The widely used Yeh and Hummer [J. Phys. Chem. B 108, 15873 (2004)] correction for the prediction of diffusion coefficient at the thermodynamic limit was applied and shown to be accurate in all cases compared to extrapolated values at infinite system size. The magnitude of correction, in all cases examined, is significant, with the smallest systems examined giving for some cases a self-diffusion coefficient approximately 15% lower than the infinite system-size extrapolated value. The results suggest that finite size corrections to computed self-diffusivities must be used in order to obtain accurate results.

Silver photo-diffusion and photo-induced macroscopic surface deformation of Ge{sub 33}S{sub 67}/Ag/Si substrate

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sakaguchi, Y., E-mail: y-sakaguchi@cross.or.jp; Asaoka, H.; Uozumi, Y.

2016-08-07

Ge-chalcogenide films show various photo-induced changes, and silver photo-diffusion is one of them which attracts lots of interest. In this paper, we report how silver and Ge-chalcogenide layers in Ge{sub 33}S{sub 67}/Ag/Si substrate stacks change under light exposure in the depth by measuring time-resolved neutron reflectivity. It was found from the measurement that Ag ions diffuse all over the matrix Ge{sub 33}S{sub 67} layer once Ag dissolves into the layer. We also found that the surface was macroscopically deformed by the extended light exposure. Its structural origin was investigated by a scanning electron microscopy.

Characterization and durability testing of plasma-sprayed zirconia-yttria and hafnia-yttria thermal barrier coatings. Part 1: Effect of spray parameters on the performance of several lots of partially stabilized zirconia-yttria powder

NASA Technical Reports Server (NTRS)

Miller, Robert A.; Leissler, George W.; Jobe, J. Marcus

1993-01-01

Initial experiments conducted on thermal barrier coatings prepared in the newly upgraded research plasma spray facility and the burner rig test facilities are discussed. Part 1 discusses experiments which establish the spray parameters for three baseline zirconia-yttria coatings. The quality of five similar coating lots was judged primarily by their response to burner rig exposure supplemented by data from other sources such as specimen characterizations and thermal diffusivity measurements. After allowing for burner rig variability, although there appears to be an optimum density (i.e., optimum microstructure) for maximum burner rig life, the distribution tends to be rather broad about the maximum. In Part 2, new hafnia-yttria-based coatings were evaluated against both baseline and alternate zirconia-yttria coatings. The hafnia-yttria coatings and the zirconia-yttria coatings that were prepared by an alternate powder vendor were very sensitive to plasma spray parameters, in that high-quality coatings were only obtained when certain parameters were employed. The reasons for this important observation are not understood. Also not understood is that the first of two replicate specimens sprayed for Part 1 consistently performed better than the second specimen. Subsequent experiments did not display this spray order affect, possibly because a chiller was installed in the torch cooling water circuit. Also, large changes in coating density were observed after switching to a new lot of electrodes. Analyses of these findings were made possible, in part, because of the development of a sensitive density measurement technique described herein in detail. The measured thermal diffusivities did not display the expected strong relationship with porosity. This surprising result was believed to have been caused by increased microcracking of the denser coatings on the stainless steel substrates.

A Massive-born Neutron Star with a Massive White Dwarf Companion

NASA Astrophysics Data System (ADS)

Cognard, Ismaël; Freire, Paulo C. C.; Guillemot, Lucas; Theureau, Gilles; Tauris, Thomas M.; Wex, Norbert; Graikou, Eleni; Kramer, Michael; Stappers, Benjamin; Lyne, Andrew G.; Bassa, Cees; Desvignes, Gregory; Lazarus, Patrick

2017-08-01

We report on the results of a 4 year timing campaign of PSR J2222-0137, a 2.44 day binary pulsar with a massive white dwarf (WD) companion, with the Nançay, Effelsberg, and Lovell radio telescopes. Using the Shapiro delay for this system, we find a pulsar mass m p = 1.76 ± 0.06 M ⊙ and a WD mass m c = 1.293 ± 0.025 M ⊙. We also measure the rate of advance of periastron for this system, which is marginally consistent with the general relativity prediction for these masses. The short lifetime of the massive WD progenitor star led to a rapid X-ray binary phase with little (< 10-2 M ⊙) mass accretion onto the neutron star; hence, the current pulsar mass is, within uncertainties, its birth mass, which is the largest measured to date. We discuss the discrepancy with previous mass measurements for this system; we conclude that the measurements presented here are likely to be more accurate. Finally, we highlight the usefulness of this system for testing alternative theories of gravity by tightly constraining the presence of dipolar radiation. This is of particular importance for certain aspects of strong-field gravity, like spontaneous scalarization, since the mass of PSR J2222-0137 puts that system into a poorly tested parameter range.

A Massive-born Neutron Star with a Massive White Dwarf Companion

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cognard, Ismaël; Guillemot, Lucas; Theureau, Gilles

We report on the results of a 4 year timing campaign of PSR J2222−0137, a 2.44 day binary pulsar with a massive white dwarf (WD) companion, with the Nançay, Effelsberg, and Lovell radio telescopes. Using the Shapiro delay for this system, we find a pulsar mass m {sub p} = 1.76 ± 0.06 M {sub ⊙} and a WD mass m {sub c} = 1.293 ± 0.025 M {sub ⊙}. We also measure the rate of advance of periastron for this system, which is marginally consistent with the general relativity prediction for these masses. The short lifetime of the massivemore » WD progenitor star led to a rapid X-ray binary phase with little (< 10{sup −2} M {sub ⊙}) mass accretion onto the neutron star; hence, the current pulsar mass is, within uncertainties, its birth mass, which is the largest measured to date. We discuss the discrepancy with previous mass measurements for this system; we conclude that the measurements presented here are likely to be more accurate. Finally, we highlight the usefulness of this system for testing alternative theories of gravity by tightly constraining the presence of dipolar radiation. This is of particular importance for certain aspects of strong-field gravity, like spontaneous scalarization, since the mass of PSR J2222−0137 puts that system into a poorly tested parameter range.« less

77 FR 22845 - Submission for OMB Review; Comment Request

Federal Register 2010, 2011, 2012, 2013, 2014

2012-04-17

... Number: 1545-2222. Type of Review: Revision of a currently approved collection. Title: VITA/TCE Volunteer... Tax Assistance (VITA) and Tax Counseling for the Elderly (TCE) programs assist seniors and individuals...

Theoretical and Empirical Studies on Using Program Mutation to Test the Functional Correctness of Programs.

DTIC Science & Technology

1980-02-01

implemented to test ANSI FORTRAN set D3. Using theorem 6 we then have programs. In building real testing tools for Theorem 18 : The recursion constructors...constants, scalar in theorems 10, 15, 16, and 18 , then Q must be variables, and array references) times the number equivalent to P. of unique data...for j,,rd1s longer thlan a fixed .1; 0. erot 2., .12.’Ie 1). Ullman2. li21122 arnd isolates and plrints each telegram along hI 2 .. 222.2.J~12.2.1 It

76 FR 39091 - Agency Information Collection Activities; Submission to OMB for Review and Approval; Comment...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-07-05

...: Betsy Metcalf, Enforcement Targeting & Data Division, Office of Compliance, 2222A, Environmental... agencies. Dated: June 28, 2011. Joseph A. Sierra, Acting Director, Collection Strategies Division. [FR Doc...

40 CFR 52.2222 - Approval status.

Code of Federal Regulations, 2011 CFR

2011-07-01

... greenhouse gases in the pollutant GHGs, by the gas's associated global warming potential published at Table A-1 to subpart A of 40 CFR part 98—Global Warming Potentials. (B) Sum the resultant value from...

System-size corrections for self-diffusion coefficients calculated from molecular dynamics simulations: The case of CO{sub 2}, n-alkanes, and poly(ethylene glycol) dimethyl ethers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Moultos, Othonas A.; Economou, Ioannis G.; Zhang, Yong

Molecular dynamics simulations were carried out to study the self-diffusion coefficients of CO{sub 2}, methane, propane, n-hexane, n-hexadecane, and various poly(ethylene glycol) dimethyl ethers (glymes in short, CH{sub 3}O–(CH{sub 2}CH{sub 2}O){sub n}–CH{sub 3} with n = 1, 2, 3, and 4, labeled as G1, G2, G3, and G4, respectively) at different conditions. Various system sizes were examined. The widely used Yeh and Hummer [J. Phys. Chem. B 108, 15873 (2004)] correction for the prediction of diffusion coefficient at the thermodynamic limit was applied and shown to be accurate in all cases compared to extrapolated values at infinite system size. Themore » magnitude of correction, in all cases examined, is significant, with the smallest systems examined giving for some cases a self-diffusion coefficient approximately 15% lower than the infinite system-size extrapolated value. The results suggest that finite size corrections to computed self-diffusivities must be used in order to obtain accurate results.« less

850-nm Zn-diffusion vertical-cavity surface-emitting lasers with with oxide-relief structure for high-speed and energy-efficient optical interconnects from very-short to medium (2km) reaches

NASA Astrophysics Data System (ADS)

Shi, Jin-Wei; Wei, Chia-Chien; Chen, Jason (Jyehong); Yang, Ying-Jay

2015-03-01

High-speed and "green" ~850 nm vertical-cavity surface-emitting lasers (VCSELs) have lately attracted lots of attention due to their suitability for applications in optical interconnects (OIs). To further enhance the speed and its maximum allowable linking distance of VCSELs are two major trends to meet the requirement of OI in next generation data centers. Recently, by use of the advanced 850 nm VCSEL technique, data rate as high as 64 Gbit/sec over 57m and 20 Gbit/sec over 2km MMF transmission have been demonstrated, respectively. Here, we will review our recent work about 850 nm Zn-diffusion VCSELs with oxide-relief apertures to further enhance the above-mentioned performances. By using Zn-diffusion, we can not only reduce the device resistance but also manipulate the number of optical modes to benefit transmission. Combing such device, which has excellent single-mode (SMSR >30 dB) and high-power (~7mW) performance, with advanced modulation format (OFDM), record-high bit-rate-distance-product through MMF (2.3 km×28 Gbit/sec) has been demonstrated. Furthermore, by selective etching away the oxide aperture inside Zn-diffusion VCSEL, significant enhancement of device speed, D-factor, and reliability can be observed. With such unique VCSEL structure, >40 Gbit/sec energy-efficient transmission over 100m MMF under extremely low-driving current density (<10kA/cm2) has been successfully demonstrated.

Communication: Diverse nanoscale cluster dynamics: Diffusion of 2D epitaxial clusters

NASA Astrophysics Data System (ADS)

Lai, King C.; Evans, James W.; Liu, Da-Jiang

2017-11-01

The dynamics of nanoscale clusters can be distinct from macroscale behavior described by continuum formalisms. For diffusion of 2D clusters of N atoms in homoepitaxial systems mediated by edge atom hopping, macroscale theory predicts simple monotonic size scaling of the diffusion coefficient, DN ˜ N-β, with β = 3/2. However, modeling for nanoclusters on metal(100) surfaces reveals that slow nucleation-mediated diffusion displaying weak size scaling β < 1 occurs for "perfect" sizes Np = L2 and L(L+1) for integer L = 3,4,… (with unique square or near-square ground state shapes), and also for Np+3, Np+4,…. In contrast, fast facile nucleation-free diffusion displaying strong size scaling β ≈ 2.5 occurs for sizes Np+1 and Np+2. DN versus N oscillates strongly between the slowest branch (for Np+3) and the fastest branch (for Np+1). All branches merge for N = O(102), but macroscale behavior is only achieved for much larger N = O(103). This analysis reveals the unprecedented diversity of behavior on the nanoscale.

Phytotoxicity as an indicator of stability of broiler production residues.

PubMed

Mendes, P M; Becker, R; Corrêa, L B; Bianchi, I; Dai Prá, M A; Lucia, T; Corrêa, E K

2016-02-01

Beddings used for successive broiler lots act as substrate to absorb water and feed from the excreta and may be subsequently used as agricultural fertilizers. This study evaluated the physicochemical characteristics and the phytotoxicity of beddings used to raise five consecutive broiler lots in five aviaries. Samples were collected for beddings not used yet and for beddings used at each of the five broiler lots. Lettuce and cucumber seeds were considered as phytotoxicity bioindicators. As beddings were used for greater number of lots, N, Ca, K, Mg and P contents generally increased, but the C content decreased, the pH alkalinized and humidity was reduced (P < 0.05). The germination index for lettuce and cucumber seeds was reduced with increased bedding (P < 0.05). Beddings used for at least five broiler lots presented decreased C:N ratio and would not recommended for agricultural use due to its toxicity for both tested seeds. Copyright © 2015 Elsevier Ltd. All rights reserved.

Diffusion of Mg dopant in metal-organic vapor-phase epitaxy grown GaN and AlxGa1-xN

NASA Astrophysics Data System (ADS)

Köhler, K.; Gutt, R.; Wiegert, J.; Kirste, L.

2013-02-01

Diffusion of the p-type dopant Mg in GaN and AlxGa1-xN which is accompanied by segregation and affected by transient effects in metal-organic vapor-phase epitaxy reactors is investigated. We have grown 110 nm thick Mg doped GaN and Al0.1Ga0.9N layers on top of undoped GaN and Al0.1Ga0.9N layers, respectively, in a temperature range between 925 °C and 1050 °C where we placed special emphasis on the lower temperature limit without diffusion to allow separation of Mg transients, diffusion, and segregation. Hereby, AlxGa1-xN layers enable monitoring of the resolution limit by secondary ion mass spectrometry analyses for the respective samples; therefore, thin AlxGa1-xN marker layers are incorporated in the thick GaN layers. We found an upper limit of 1.25 × 1019 cm-3 for diffusing Mg atoms in both sample types. Owing to the marked influence of Mg segregation in Al0.1Ga0.9N, diffusion is only seen by using a GaN cap on top of the Al0.1Ga0.9N layer sequence. Diffusion in Al0.1Ga0.9N is shown to be increased by about 25%-30% compared to GaN. Post growth annealing experiments under conditions equivalent to those used for growth of the Mg doped samples showed negligible diffusion. Comparing the results to well established findings on other doped III-V compounds, diffusion is explained by an interstitial-substitutional mechanism with a diffusion coefficient, which is concentration dependent. Analysis of the temperature dependent diffusivity revealed an activation energy of 5.0 eV for GaN:Mg and 5.2 eV for Al0.1Ga0.9N:Mg.

Escape and finite-size scaling in diffusion-controlled annihilation

DOE PAGES

Ben-Naim, Eli; Krapivsky, Paul L.

2016-12-16

In this paper, we study diffusion-controlled single-species annihilation with a finite number of particles. In this reaction-diffusion process, each particle undergoes ordinary diffusion, and when two particles meet, they annihilate. We focus on spatial dimensions d>2 where a finite number of particles typically survive the annihilation process. Using scaling techniques we investigate the average number of surviving particles, M, as a function of the initial number of particles, N. In three dimensions, for instance, we find the scaling law M ~ N 1/3 in the asymptotic regime N»1. We show that two time scales govern the reaction kinetics: the diffusionmore » time scale, T ~ N 2/3, and the escape time scale, τ ~ N 4/3. The vast majority of annihilation events occur on the diffusion time scale, while no annihilation events occur beyond the escape time scale.« less

Multisite reproducibility of the broth microdilution method for susceptibility testing of Nocardia species.

PubMed

Conville, Patricia S; Brown-Elliott, Barbara A; Wallace, Richard J; Witebsky, Frank G; Koziol, Deloris; Hall, Geraldine S; Killian, Scott B; Knapp, Cindy C; Warshauer, David; Van, Tam; Wengenack, Nancy L; Deml, Sharon; Woods, Gail L

2012-04-01

Antimicrobial susceptibility testing (AST) of clinical isolates of Nocardia is recommended to detect resistance to commonly used antimicrobial agents; such testing is complicated by difficulties in inoculum preparation and test interpretation. In this study, six laboratories performed repetitive broth microdilution testing on single strains of Nocardia brasiliensis, Nocardia cyriacigeorgica, Nocardia farcinica, Nocardia nova, and Nocardia wallacei. For each isolate, a total of 30 microdilution panels from three different lots were tested at most sites. The goal of the study was to determine the inter- and intralaboratory reproducibility of susceptibility testing of this group of isolates. Acceptable agreement (>90% agreement at ±1 dilution of the MIC mode) was found for amikacin, ciprofloxacin, clarithromycin, and moxifloxacin. After eliminating MIC values from single laboratories whose results showed the greatest deviation from those of the remaining laboratories, acceptable agreement was also found for amoxicillin-clavulanic acid, linezolid, minocycline, and tobramycin. Results showed unsatisfactory reproducibility of broth microdilution testing of ceftriaxone with N. cyriacigeorgica and N. wallacei, tigecycline with N. brasiliensis and N. cyriacigeorgica, and sulfonamides with N. farcinica and N. wallacei. N. nova ATCC BAA-2227 is proposed as a quality control organism for AST of Nocardia sp., and the use of a disk diffusion test for sulfisoxazole is proposed as a check of the adequacy of the inoculum and to confirm sulfonamide MIC results.

Diffusivity in surficial sediments and benthic mats determined by use of a combined N 2O-O 2 microsensor

NASA Astrophysics Data System (ADS)

Glud, Ronnie Nøhr; Jensen, Kim; Revsbech, Niels Peter

1995-01-01

Diffusional characteristics of two biologically active surface sediments were determined by use of a combined N 2O-O 2 microsensor. By analyzing changes in the N2O-gradients in these sediments, it was possible to determine the product ( φDs) for this species with submillimetre depth resolution, where φ is the porosity and Ds the substrate diffusion coefficient. The ( φDs)-value for O 2 could be calculated then from ( φDs)-value for N 2O, because the diffusivity of the two molecules were modified in the same way within the sediment. Both sediments exhibited fine-scale horizontal and vertical variability in diffusion characteristics, and this must be accounted for when analyzing microprofile data. The average ( φDs)-value for N 2O at 20°C for an estuarine surface sediment was 0.93 × 10 -5 cm2 s -1 (at 0-4 mm depth), while the value for the upper 2 mm of a stream sediment covered by a microbial mat was 1.42 × 10 -5 cm 2 s -1. Biological inactivation and oxidation by exposure to an O 2 atmosphere had no effect on the measured ( φDs) for the estuarine sediment; however, the value for the sediment covered by a microbial mat, with dense populations of meiofauna, decreased by 20%. The method presented is ideal for measurements of diffusivity at a high spatial resolution in surficial sediments and densely packed microbial communities.

Recent Applications of 2D Inorganic Nanosheets for Emerging Energy Storage System.

PubMed

Oh, Seung Mi; Patil, Sharad B; Jin, Xiaoyan; Hwang, Seong-Ju

2018-04-03

Among many types of nanostructured inorganic materials, highly anisotropic 2D nanosheets provide unique advantages in designing and synthesizing efficient electrode and electrocatalyst materials for novel energy storage technologies. 2D inorganic nanosheets boast lots of unique characteristics such as high surface area, short ion diffusion path, tailorable compositions, and tunable electronic structures. These merits of 2D inorganic nanosheets render them promising candidate materials as electrodes for diverse secondary batteries and supercapacitors, and electrocatalysts. A wide spectrum of examples is presented for inorganic nanosheet-based electrodes and electrocatalysts. Future perspectives in research about 2D nanosheet-based functional materials are discussed to provide insight for the development of next-generation energy storage systems using 2D nanostructured materials. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Prognostic Significance of Diffuse Large B-Cell Lymphoma Cell of Origin Determined by Digital Gene Expression in Formalin-Fixed Paraffin-Embedded Tissue Biopsies

PubMed Central

Scott, David W.; Mottok, Anja; Ennishi, Daisuke; Wright, George W.; Farinha, Pedro; Ben-Neriah, Susana; Kridel, Robert; Barry, Garrett S.; Hother, Christoffer; Abrisqueta, Pau; Boyle, Merrill; Meissner, Barbara; Telenius, Adele; Savage, Kerry J.; Sehn, Laurie H.; Slack, Graham W.; Steidl, Christian; Staudt, Louis M.; Connors, Joseph M.; Rimsza, Lisa M.; Gascoyne, Randy D.

2015-01-01

Purpose To evaluate the prognostic impact of cell-of-origin (COO) subgroups, assigned using the recently described gene expression–based Lymph2Cx assay in comparison with International Prognostic Index (IPI) score and MYC/BCL2 coexpression status (dual expressers). Patients and Methods Reproducibility of COO assignment using the Lymph2Cx assay was tested employing repeated sampling within tumor biopsies and changes in reagent lots. The assay was then applied to pretreatment formalin-fixed paraffin-embedded tissue (FFPET) biopsies from 344 patients with de novo diffuse large B-cell lymphoma (DLBCL) uniformly treated with rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) at the British Columbia Cancer Agency. MYC and BCL2 protein expression was assessed using immunohistochemistry on tissue microarrays. Results The Lymph2Cx assay provided concordant COO calls in 96% of 49 repeatedly sampled tumor biopsies and in 100% of 83 FFPET biopsies tested across reagent lots. Critically, no frank misclassification (activated B-cell–like DLBCL to germinal center B-cell–like DLBCL or vice versa) was observed. Patients with activated B-cell–like DLBCL had significantly inferior outcomes compared with patients with germinal center B-cell–like DLBCL (log-rank P < .001 for time to progression, progression-free survival, disease-specific survival, and overall survival). In pairwise multivariable analyses, COO was associated with outcomes independent of IPI score and MYC/BCL2 immunohistochemistry. The prognostic significance of COO was particularly evident in patients with intermediate IPI scores and the non–MYC-positive/BCL2-positive subgroup (log-rank P < .001 for time to progression). Conclusion Assignment of DLBCL COO by the Lymph2Cx assay using FFPET biopsies identifies patient groups with significantly different outcomes after R-CHOP, independent of IPI score and MYC/BCL2 dual expression. PMID:26240231

Diffusion of chains in a periodic potential

NASA Astrophysics Data System (ADS)

Terranova, G. R.; Mártin, H. O.; Aldao, C. M.

2017-09-01

We studied the diffusion of 1D rigid chains in a square wave potential of period T. We considered chains of type A (composed of N particles A) and chains of type A-B (composed of N/2 particles A and N/2 particles B). The square wave potential represents domains, a lamellar structure observed for block copolymers, in which the repulsive δ energy between each A particle (B particle) of the chain and B particles (A particles) of the medium where the chains diffuse. From Monte Carlo simulations and analytical results it is found that the normalized diffusivity D, for N\\ll T , presents a universal behavior as a function of X  =  Nδ for chains of type A and X  =  (Nδ  -  lnT 2) for chains of type A-B, with and exponential decay for large values of X. For fixed values of δ and T, D is a periodic function of N with period T and 2T for chains of type A and type A-B, respectively.

Banded Structures in Electron Pitch Angle Diffusion Coefficients from Resonant Wave Particle Interactions

NASA Technical Reports Server (NTRS)

Tripathi, A. K.; Singhal, R. P.; Khazanov, G. V.; Avanov, L. A.

2016-01-01

Electron pitch angle (D (alpha)) and momentum (D(pp)) diffusion coefficients have been calculated due to resonant interactions with electrostatic electron cyclotron harmonic (ECH) and whistler mode chorus waves. Calculations have been performed at two spatial locations L = 4.6 and 6.8 for electron energies 10 keV. Landau (n = 0) resonance and cyclotron harmonic resonances n = +/-1, +/-2,...+/-5 have been included in the calculations. It is found that diffusion coefficient versus pitch angle (alpha) profiles show large dips and oscillations or banded structures. The structures are more pronounced for ECH and lower band chorus (LBC) and particularly at location 4.6. Calculations of diffusion coefficients have also been performed for individual resonances. It is noticed that the main contribution of ECH waves in pitch angle diffusion coefficient is due to resonances n = +1 and n = +2. A major contribution to momentum diffusion coefficients appears from n = +2. However, the banded structures in D alpha and Dpp coefficients appear only in the profile of diffusion coefficients for n = +2. The contribution of other resonances to diffusion coefficients is found to be, in general, quite small or even negligible. For LBC and upper band chorus waves, the banded structures appear only in Landau resonance. The Dpp diffusion coefficient for ECH waves is one to two orders smaller than D alpha coefficients. For chorus waves, Dpp coefficients are about an order of magnitude smaller than D alpha coefficients for the case n does not = 0. In case of Landau resonance, the values of Dpp coefficient are generally larger than the values of D alpha coefficients particularly at lower energies. As an aid to the interpretation of results, we have also determined the resonant frequencies. For ECH waves, resonant frequencies have been estimated for wave normal angle 89 deg and harmonic resonances n = +1, +2, and +3, whereas for whistler mode waves, the frequencies have been calculated for angle 10 deg and Landau resonance. Further, in ECH waves, the banded structures appear for electron energies (is) greater than1 keV, and for whistler mode chorus waves, structures appear for energies greater than 2 keV at L = 4.6 and above 200 eV for L = 6.8. The results obtained in the present work will be helpful in the study of diffusion curves and will have important consequences for diffuse aurora and pancake distributions.

Banded Structures in Electron Pitch Angle Diffusion Coefficients from Resonant Wave-Particle Interactions

NASA Technical Reports Server (NTRS)

Tripathi, A. K.; Singhal, R. P.; Khazanov, G. V.; Avanov, L. A.

2016-01-01

Electron pitch angle (D(sub (alpha alpha))) and momentum (D(sub pp)) diffusion coefficients have been calculated due to resonant interactions with electrostatic electron cyclotron harmonic (ECH) and whistler mode chorus waves. Calculations have been performed at two spatial locations L=4.6 and 6.8 for electron energies less than or equal to 10 keV. Landau (n=0) resonance and cyclotron harmonic resonances n= +/- 1, +/-2, ... +/-5 have been included in the calculations. It is found that diffusion coefficient versus pitch angle (alpha) profiles show large dips and oscillations or banded structures. The structures are more pronounced for ECH and lower band chorus (LBC) and particularly at location 4.6. Calculations of diffusion coefficients have also been performed for individual resonances. It is noticed that the main contribution of ECH waves in pitch angle diffusion coefficient is due to resonances n=+1 and n=+2. A major contribution to momentum diffusion coefficients appears from n=+2. However, the banded structures in D(sub alpha alpha) and D(sub pp) coefficients appear only in the profile of diffusion coefficients for n=+2. The contribution of other resonances to diffusion coefficients is found to be, in general, quite small or even negligible. For LBC and upper band chorus waves, the banded structures appear only in Landau resonance. The D(sub pp) diffusion coefficient for ECH waves is one to two orders smaller than D(sub alpha alpha) coefficients. For chorus waves, D(sub pp) coefficients are about an order of magnitude smaller than D(sub alpha alpha) coefficients for the case n does not equal 0. In case of Landau resonance, the values of D(sub pp) coefficient are generally larger than the values of D(sub alpha alpha) coefficients particularly at lower energies. As an aid to the interpretation of results, we have also determined the resonant frequencies. For ECH waves, resonant frequencies have been estimated for wave normal angle 89 deg and harmonic resonances n= +1, +2, and +3, whereas for whistler mode waves, the frequencies have been calculated for angle 10 deg and Landau resonance. Further, in ECH waves, the banded structures appear for electron energies 1 greater than or equal to keV, and for whistler mode chorus waves, structures appear for energies greater than 2 keV at L=4.6 and above 200 eV for L=6.8. The results obtained in the present work will be helpful in the study of diffusion curves and will have important consequences for diffuse aurora and pancake distributions.

A search with Copernicus for interstellar N2 in diffuse clouds

NASA Technical Reports Server (NTRS)

Lutz, B. L.; Snow, T. P., Jr.; Owen, T.

1979-01-01

Multiple Copernicus scans of two N2 band regions (near 958.5 and 960.2A) of Delta Sco and Epsilon Per are reported. The observations indicate upper limits for the number of N2 molecules equal to 1.0-3.8 times 10 to the -12th/sq cm and 1.2-4.4 times 10 to the -12th/sq cm, respectively; the limits depend on the cloud temperature. It is suggested that the limits are consistent with the column densities predicted by chemical models for diffuse interstellar clouds, and the predicted relative abundances are presented in terms of the ratio of N(N2)/(2N(H2) + N(Hl)).

Statistical Aspects of Ice Gouging on the Alaskan Shelf of the Beaufort Sea,

DTIC Science & Technology

1983-09-01

ici 1)N I’ao’ ofciv i1111 da t Cl t it:c) dcc iiiiik i onIII ol l % I IIouI ile as~ d a 1c’ iiici of ,ic dcli al\\2 Not1. I % .. ol I lOt ii title...Ccii hilial dclisl to fileicll of a p-ii peline lot a IX1 (X)-. Miid 10-\\Cat McUMr 1crOd .31 .... v STATISTICAL ASPECTS OF ICE GOUGING ON THE ALASKAN...dlata obtained hetceni 19-2 and -l aw etcnatr’’ib (I-). I Ilti, v, ’Icletriiutted 1 9,9 (ele cl iug 1 974) \\ -ere CL Ird in the pr~ mI. a~ctag ing tile

The safety of the H1N1 influenza A vaccine in egg allergic individuals.

PubMed

Greenhawt, Matthew J; Chernin, Anna S; Howe, Laura; Li, James T; Sanders, Georgiana

2010-11-01

The safety of H1N1 vaccine is unknown in egg allergic (EA) recipients. To establish the safety of administering H1N1 vaccine and to evaluate the predictability of H1N1 skin testing in EA patients. In a controlled, prospective trial, H1N1 skin testing and vaccination was compared between EA patients (n = 105) and non-EA controls (n = 19). Those with negative H1N1 skin test results received a full H1N1 dose; those with a positive skin test result received a graded challenge (10%, 90%). Booster vaccine, if required, was given as a single dose from a different lot without prior testing. Prick and intradermal test results were positive in 3 (2.4%) of 124 and 41 (33.1%) of 124 study participants, respectively. Forty-one individuals received a 2-step graded vaccine challenge, including 13 of 25 with a history of egg anaphylaxis. No significant allergic reactions resulted from either method of vaccination or from subsequent booster doses. All study participants received the H1N1 vaccine without significant allergic reactions. Skin testing is unnecessary and does not predict vaccine tolerance. All study participants who received a graded challenge tolerated a single dose booster from a different, untested lot, including 7 individuals with a history of egg-induced anaphylaxis. We recommend administration of H1N1 vaccine to EA children without prior skin testing or graded challenge dosing. Copyright © 2010 American College of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

Diffusion barrier properties of single- and multilayered quasi-amorphous tantalum nitride thin films against copper penetration

NASA Astrophysics Data System (ADS)

Chen, G. S.; Chen, S. T.

2000-06-01

Tantalum-related thin films containing different amounts of nitrogen are sputter deposited at different argon-to-nitrogen flow rate ratios on (100) silicon substrates. Using x-ray diffractometry, transmission electron microscopy, composition and resistivity analyses, and bending-beam stress measurement technique, this work examines the impact of varying the nitrogen flow rate, particularly on the crystal structure, composition, resistivity, and residual intrinsic stress of the deposited Ta2N thin films. With an adequate amount of controlled, reactive nitrogen in the sputtering gas, thin films of the tantalum nitride of nominal formula Ta2N are predominantly amorphous and can exist over a range of nitrogen concentrations slightly deviated from stoichiometry. The single-layered quasi-amorphous Ta2N (a-Ta2N) thin films yield intrinsic compressive stresses in the range 3-5 GPa. In addition, the use of the 40-nm-thick a-Ta2N thin films with different nitrogen atomic concentrations (33% and 36%) and layering designs as diffusion barriers between silicon and copper are also evaluated. When subjected to high-temperature annealing, the single-layered a-Ta2N barrier layers degrade primarily by an amorphous-to-crystalline transition of the barrier layers. Crystallization of the single-layered stoichiometric a-Ta2N (Ta67N33) diffusion barriers occurs at temperatures as low as 450 °C. Doing so allows copper to preferentially penetrate through the grain boundaries or thermal-induced microcracks of the crystallized barriers and react with silicon, sequentially forming {111}-facetted pyramidal Cu3Si precipitates and TaSi2 Overdoping nitrogen into the amorphous matrix can dramatically increase the crystallization temperature to 600 °C. This temperature increase slows down the inward diffusion of copper and delays the formation of both silicides. The nitrogen overdoped Ta2N (Ta64N36) diffusion barriers can thus be significantly enhanced so as to yield a failure temperature 100 °C greater than that of the Ta67N33 diffusion barriers. Moreover, multilayered films, formed by alternately stacking the Ta67N33 and Ta64N36 layers with an optimized bilayer thickness (λ) of 10 nm, can dramatically reduce the intrinsic compressive stress to only 0.7 GPa and undergo high-temperature annealing without crystallization. Therefore, the Ta67N33/Ta64N36 multilayered films exhibit a much better barrier performance than the highly crystallization-resistant Ta64N36 single-layered films.

Power reserve following ramp-incremental cycling to exhaustion: implications for muscle fatigue and function.

PubMed

Hodgson, Michael D; Keir, Daniel A; Copithorne, David B; Rice, Charles L; Kowalchuk, John M

2018-04-26

In ramp-incremental cycling exercise, some individuals are capable of producing power output (PO) in excess of that produced at their limit of tolerance (LoT) while others cannot. This study sought to describe the: 1) prevalence of a "power reserve" within a group of young men (n=21; mean {plus minus} SD: age 25{plus minus}4 years; V̇O 2max 45{plus minus}8 ml•kg -1 •min -1 ); and 2) muscle fatigue characteristics of those with and without a power reserve. Power reserve was determined as the difference between peak PO achieved during a ramp-incremental test to exhaustion and maximal, single-leg isokinetic dynamometer power. Pre- versus post-exercise changes in voluntary and electrically-stimulated single-leg muscle force production measures (maximal voluntary contraction, voluntary activation, maximal isotonic velocity and isokinetic power; 1-, 10-, 50-Hz torque and 10/50-Hz ratio), V̇O 2max and constant-PO cycling time-to-exhaustion also were assessed. A dichotomy in power reserve was prevalent within the sample resulting in two groups: 1) "No Reserve" (NRES: <5% reserve; n=10) and 2) "Reserve" (RES: >15% reserve; n=11). At the LoT, all participants had achieved V̇O 2max . Muscle fatigue was evident in both groups, although the NRES group had greater reductions (p<0.05) in 10-Hz peak torque (PT), 10/50 Hz ratio, and maximal velocity. Time-to-exhaustion during the constant-PO test was 22{plus minus}16% greater (p<0.05) in RES (116{plus minus}19 s; PO = 317{plus minus}52 W) than in NRES (90{plus minus}23 s; PO = 337{plus minus}71 W), despite similar ramp-incremental exercise durations and V̇O 2max between groups. The differences in muscle fatigue and function between groups suggest that the mechanisms contributing to the LoT are not uniform.

Relativistic Electron Precipitation: An Observational Study.

DTIC Science & Technology

1980-01-01

al., 1970). These so-called "n + 1/2" waves (- n + 1/2) are found throughout the magnetosphere outside the plasmapause (Kennel et al., 1970; Shaw and...diffusion scattering one requires 2 L D~ . LSD - z ~.(21) 73 where aL = loss cone pitch angle D SD = coefficient for strong diffusion. Equation (20) can be...with substitutions yields a fluctuating field wave amplitude for strong electron diffusion: a." 0- x(23) and 00for f= LSD (24) LRo LRo + For ions

76 FR 28076 - Notice of Inventory Completion: Museum of Anthropology, Washington State University, Pullman, WA...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-05-13

... scrapers, 1 bone scraper handle, 1 lot of mussel shells, 1 lot of red ochre, 2 bone awls, 1 lot of charcoal... lots of bag residue, 4 lots of animal bones, 1 stone net sinker, 1 lot of tin can fragments, 2...

How can water quality be improved when the urban waste water directive has been fulfilled? A case study of the Lot river (France).

PubMed

Garnier, Josette; Ramarson, Antsiva; Thieu, Vincent; Némery, Julien; Théry, Sylvain; Billen, Gilles; Coynel, Alexandra

2018-04-01

The Lot river, a major tributary of the downstream Garonne river, the largest river on the Northern side of the Pyrenees Mountains, was intensively studied in the 1970s. A pioneering program called "Lot Rivière Claire" provided a diagnosis of water quality at the scale of the whole watershed and proposed an ambitious program to manage nutrient pollution and eutrophication largely caused by urban wastewater releases. Later on, the implementation of European directives from 1991 to 2000 resulted in the nearly complete treatment of point sources of pollution in spite of a doubling of the basin's population. At the outlet of the Lot river, ammonium and phosphate contamination which respectively peaked to 1 mg N-NH 4 L -1 and 0.3 mg P-PO 4 L -1 in the 1980s returned to much lower levels in recent years (0.06 mg N-NH 4 L -1 and 0.02 mg P-PO 4 L -1 ), a reduction by a factor 15. However, during this time, nitrate contamination has regularly increased since the 1980s, from 0.5 to 1.2 mg N-NO 3 L -1 in average, owing to the intensification of agriculture and livestock farming. Application of the Riverstrahler model allowed us to simulate the water quality of the Lot drainage network for the 2002-2014 period. We showed that, with respect to algal requirements, phosphorus and silica are well balanced, but nitrogen remains largely in excess over phosphorus and silica. This imbalance can be problematic for the ecological status of the water bodies. Using the model, for simulating various scenarios of watershed management, we showed that improvement of urban wastewater treatment would not result in any significant change in the river's water quality. Even though arable land occupies a rather limited fraction of the watershed area, only the adoption of better farming practices or more radical changes in the agro-food system could reverse the trend of increasing nitrate contamination.

Annealing of gallium nitride under high-N 2 pressure

NASA Astrophysics Data System (ADS)

Porowski, S.; Jun, J.; Krukowski, S.; Grzegory, I.; Leszczynski, M.; Suski, T.; Teisseyre, H.; Foxon, C. T.; Korakakis, D.

1999-04-01

GaN is the key material for blue and ultraviolet optoelectronics. It is a strongly bonded wurztite structure semiconductor with the direct energy gap 3.5 eV. Due to strong bonding, the diffusion processes require high temperatures, above 1300 K. However at this temperature range at ambient pressure, GaN becomes unstable and dissociates into Ga and N 2. Therefore high pressure of N 2 is required to study the diffusion and other annealing related processes. We studied annealing of bulk GaN nitride single crystals grown under high pressure and also annealing of homo- and heteroepitaxial GaN layers grown by MOCVD technique. Annealing at temperatures above 1300 K influences strongly the structural and optical properties of GaN crystals and layers. At this temperature diffusion of the Mg and Zn acceptors have been observed. In spite of very interesting experimental observations the understanding of microscopic mechanisms of these processes is limited.

7. YOSEMITE VALLEY SHUTTLE BUS AT SENTINEL BRIDGE SHUTTLE BUS ...

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

7. YOSEMITE VALLEY SHUTTLE BUS AT SENTINEL BRIDGE SHUTTLE BUS AND PARKING LOT AREA. LOOKING WNW. GIS: N-37 40 36.2 / W-119 44 45.0 - Yosemite National Park Roads & Bridges, Yosemite Village, Mariposa County, CA

Adsorption, Desorption, and Diffusion of Nitrogen in a Model Nanoporous Material: II. Diffusion Limited Kinetics in Amorphous Solid Water

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zubkov, Tykhon; Smith, R. Scott; Engstrom, Todd R.

2007-11-14

Tykhon Zubkov, R. Scott Smith, Todd R. Engstrom, and Bruce D. Kay The adsorption, desorption, and diffusion kinetics of N2 on thick (up to ~9 mm) porous films of amorphous solid water (ASW) films were studied using molecular beam techniques and temperature programmed desorption (TPD). Porous ASW films were grown on Pt(111) at low temperature (<30 K) from a collimated H2O beam at glancing incident angles. In thin films (<1 mm), the desorption kinetics are well described by a model that assumes rapid and uniform N2 distribution throughout the film. In thicker films, (>1 mm), N2 adsorption at 27 Kmore » results in a non-uniform distribution where most of N2 is trapped in the outer region of the film. Redistribution of N2 can be induced by thermal annealing. The apparent activation energy for this process is ~7 kJ/mol, which is approximately half of the desorption activation energy at the corresponding coverage. Blocking adsorption sites near the film surface facilitates transport into the film. Despite the onset of limited diffusion, the adsorption kinetics are efficient, precursor-mediated and independent of film thickness. An adsorption mechanism is proposed, in which a high-coverage N2 front propagates into a pore by the rapid transport of physisorbed 2nd layer N2 species on top of the 1st layer chemisorbed layer.« less

Highly Permeable AlPO-18 Membranes for N 2 /CH 4 Separation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zong, Zhaowang; Elsaidi, Sameh K.; Thallapally, Praveen K.

Herein we demonstrate that AlPO-18 membranes can separate N2/CH4 gas mixtures at unprecedented N2 permeances. The best membranes separated N2/CH4 mixtures with N2 permeances as high as 3076 GPU and separation selectivities as high as 4.6. Gas mixture separation data, N2 and CH4 adsorption isotherms, ideal adsorbed solution theory (IAST), and breakthrough experiments were collected to understand the separation mechanisms. Competitive adsorption and differences in diffusivities were identified as the prevailing separation mechanisms. Differences in diffusivity played a more dominant role than the competitive adsorption, and led to nitrogen selective membranes.

Atomistic simulations of CO2 and N2 within cage-type silica zeolites.

PubMed

Madison, Lindsey; Heitzer, Henry; Russell, Colin; Kohen, Daniela

2011-03-01

The behavior of CO(2) and N(2), both as single components and as binary mixtures, in two cage-type silica zeolites was studied using atomistic simulations. The zeolites considered, ITQ-3 and paradigm cage-type zeolite ZK4 (the all-silica analog of LTA), were chosen so that the principles illustrated can be generalized to other adsorbent/adsorbate systems with similar topology and types of interactions. N(2) was chosen both because of the potential uses of N(2)/CO(2) separations and because it differs from CO(2) most significantly in the magnitude of its Coulombic interactions with zeolites. Despite similarities between N(2) and CO(2) diffusion in other materials, we show here that the diffusion of CO(2) within cage-type zeolites is dominated by an energy barrier to diffusion located at the entrance to the narrow channels connecting larger cages. This barrier originates in Coulombic interactions between zeolites and CO(2)'s quadrupole and results in well-defined orientations for the diffusing molecules. Furthermore, CO(2)'s favorable electrostatic interactions with the zeolite framework result in preferential binding in the windows between cages. N(2)'s behavior, in contrast, is more consistent with that of molecules previously studied. Our analysis suggests that CO(2)'s behavior might be common for adsorbates with quadrupoles that interact strongly with a material that has narrow windows between cages.

Chemical Complexity in Local Diffuse and Translucent Clouds: Ubiquitous Linear C3H and CH3CN, a Detection of HC3N and an Upper Limit on the Abundance of CH2CN

NASA Astrophysics Data System (ADS)

Liszt, Harvey; Gerin, Maryvonne; Beasley, Anthony; Pety, Jerome

2018-04-01

We present Jansky Very Large Array observations of 20–37 GHz absorption lines from nearby Galactic diffuse molecular gas seen against four cosmologically distant compact radio continuum sources. The main new observational results are that l-C3H and CH3CN are ubiqitous in the local diffuse molecular interstellar medium at {\\text{}}{A}{{V}} ≲ 1, while HC3N was seen only toward B0415 at {\\text{}}{A}{{V}} > 4 mag. The linear/cyclic ratio is much larger in C3H than in C3H2 and the ratio CH3CN/HCN is enhanced compared to TMC-1, although not as much as toward the Horsehead Nebula. More consequentially, this work completes a long-term program assessing the abundances of small hydrocarbons (CH, C2H, linear and cyclic C3H and C3 {{{H}}}2, and C4H and C4H‑) and the CN-bearing species (CN, HCN, HNC, HC3N, HC5N, and CH3CN): their systematics in diffuse molecular gas are presented in detail here. We also observed but did not strongly constrain the abundances of a few oxygen-bearing species, most prominently HNCO. We set limits on the column density of CH2CN, such that the anion CH2CN‑ is only viable as a carrier of diffuse interstellar bands if the N(CH2CN)/N(CH2CN‑) abundance ratio is much smaller in this species than in any others for which the anion has been observed. We argue that complex organic molecules (COMS) are not present in clouds meeting a reasonable definition of diffuse molecular gas, i.e., {\\text{}}{A}{{V}} ≲ 1 mag. Based on observations obtained with the NRAO Jansky Very Large Array (VLA).

Lot-to-lot consistency of a tetravalent dengue vaccine in healthy adults in Australia: a randomised study.

PubMed

Torresi, Joseph; Heron, Leon G; Qiao, Ming; Marjason, Joanne; Chambonneau, Laurent; Bouckenooghe, Alain; Boaz, Mark; van der Vliet, Diane; Wallace, Derek; Hutagalung, Yanee; Nissen, Michael D; Richmond, Peter C

2015-09-22

The recombinant yellow fever-17D-dengue virus, live, attenuated, tetravalent dengue vaccine (CYD-TDV) has undergone extensive clinical trials. Here safety and consistency of immunogenicity of phase III manufacturing lots of CYD-TDV were evaluated and compared with a phase II lot and placebo in a dengue-naïve population. Healthy 18-60 year-olds were randomly assigned in a 3:3:3:3:1 ratio to receive three subcutaneous doses of either CYD-TDV from any one of three phase III lots or a phase II lot, or placebo, respectively in a 0, 6, 12 month dosing schedule. Neutralising antibody geometric mean titres (PRNT50 GMTs) for each of the four dengue serotypes were compared in sera collected 28 days after the third vaccination-equivalence among lots was demonstrated if the lower and upper limits of the two-sided 95% CIs of the GMT ratio were ≥0.5 and ≤2.0, respectively. 712 participants received vaccine or placebo and 614 (86%) completed the study; 17 (2.4%) participants withdrew after adverse events. Equivalence of phase III lots was demonstrated for 11 of 12 pairwise comparisons. One of three comparisons for serotype 2 was not statistically equivalent. GMTs for serotype 2 in phase III lots were close to each other (65.9, 44.1 and 58.1, respectively). Phase III lots can be produced in a consistent manner with predictable immune response and acceptable safety profile similar to previously characterised phase II lots. The phase III lots may be considered as not clinically different as statistical equivalence was shown for serotypes 1, 3 and 4 across the phase III lots. For serotype 2, although equivalence was not shown between two lots, the GMTs observed in the phase III lots were consistently higher than those for the phase II lot. As such, in our view, biological equivalence for all serotypes was demonstrated. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Lack of evidence for the presence of emerging HoBi-like viruses in North American fetal bovine serum lots.

PubMed

Bauermann, Fernando V; Flores, Eduardo F; Falkenberg, Shollie M; Weiblen, Rudi; Ridpath, Julia F

2014-01-01

The detection of an emerging pestivirus species, "HoBi-like virus," in fetal bovine serum (FBS) labeled as U.S. origin, but packaged in Europe, raised concerns that HoBi-like virus may have entered the United States. In the current study, 90 lots of FBS originating in North America (NA) were screened for pestivirus antigen and antibodies. Lots in group 1 (G1, 72 samples) and group 2 (G2, 9 samples) originated in NA and were packaged in the United States. Group 3 (G3) was composed of 9 lots collected in NA and processed in Europe. Lots in G1 were claimed negative for Bovine viral diarrhea virus (BVDV), while lots in G2 and G3 were claimed positive by the commercial processor. All lots in G1 and G2 tested negative by reverse transcription polymerase chain reaction (RT-PCR) using HoBi-like-specific primers. Two G1 lots tested positive by BVDV RT-PCR. One of these was also positive by virus isolation. All G2 lots were positive by BVDV RT-PCR. In addition, four G2 lots were VI positive while 1 lot was antigen-capture enzyme-linked immunosorbent assay (ELISA) positive. Two G3 lots were positive by HoBi-like-specific RT-PCR tests. All lots were negative for HoBi_D32/00 neutralizing antibodies. Seven lots (4 G1; 1 G2; 2 G3) had antibodies against BVDV by virus neutralization and/or antigen-capture ELISA. While there is no evidence of HoBi-like viruses in NA based on tested samples, further studies are required to validate HoBi-like virus-free status and develop means to prevent the spread of HoBi-like virus into NA.

Integrating Staff Elements, Personality Type and Groupthink

DTIC Science & Technology

2009-01-01

16.67% 0.00% 0.00% 22.22% ISTP ISFP INFP INTP 0.00% 0.00% 0.00% 5.56% ESTP ESFP ENFP ENTP 0.00% 5.56% 0.00% 11.11% ESTJ ESFJ ENFJ ENTJ 5.56...22.22 ENTP 2 11.11 INTP 1 5.56 ENFJ 1 5.56 Total Responses 18 100.00 % 35 What is your basic...is unlimited 13. SUPPLEMENTARY NOTES This monograph presents original research that seeks to reveal the relationship between individual

Estimation of Knudsen diffusion coefficients from tracer experiments conducted with a binary gas system and a porous medium.

PubMed

Hibi, Yoshihiko; Kashihara, Ayumi

2018-03-01

A previous study has reported that Knudsen diffusion coefficients obtained by tracer experiments conducted with a binary gas system and a porous medium are consistently smaller than those obtained by permeability experiments conducted with a single-gas system and a porous medium. To date, however, that study is the only one in which tracer experiments have been conducted with a binary gas system. Therefore, to confirm this difference in Knudsen diffusion coefficients, we used a method we had developed previously to conduct tracer experiments with a binary carbon dioxide-nitrogen gas system and five porous media with permeability coefficients ranging from 10 -13 to 10 -11  m 2 . The results showed that the Knudsen diffusion coefficient of N 2 (D N2 ) (cm 2 /s) was related to the effective permeability coefficient k e (m 2 ) as D N2  = 7.39 × 10 7 k e 0.767 . Thus, the Knudsen diffusion coefficients of N 2 obtained by our tracer experiments were consistently 1/27 of those obtained by permeability experiments conducted with many porous media and air by other researchers. By using an inversion simulation to fit the advection-diffusion equation to the distribution of concentrations at observation points calculated by mathematically solving the equation, we confirmed that the method used to obtain the Knudsen diffusion coefficient in this study yielded accurate values. Moreover, because the Knudsen diffusion coefficient did not differ when columns with two different lengths, 900 and 1500 mm, were used, this column property did not influence the flow of gas in the column. The equation of the dusty gas model already includes obstruction factors for Knudsen diffusion and molecular diffusion, which relate to medium heterogeneity and tortuosity and depend only on the structure of the porous medium. Furthermore, there is no need to take account of any additional correction factor for molecular diffusion except the obstruction factor because molecular diffusion is only treated in a multicomponent gas system. Thus, molecular diffusion considers only the obstruction factor related to tortuosity. Therefore, we introduced a correction factor for a multicomponent gas system into the DGM equation, multiplying the Knudsen diffusion coefficient, which includes the obstruction factor related to tortuosity, by this correction factor. From the present experimental results, the value of this correction factor was 1/27, and it depended only on the structure of the gas system in the porous medium. Copyright © 2018 Elsevier B.V. All rights reserved.

Atomistic Molecular Dynamics Simulations of Carbon Dioxide Diffusivity in n-Hexane, n-Decane, n-Hexadecane, Cyclohexane, and Squalane.

PubMed

Moultos, Othonas A; Tsimpanogiannis, Ioannis N; Panagiotopoulos, Athanassios Z; Trusler, J P Martin; Economou, Ioannis G

2016-12-22

Atomistic molecular dynamics simulations were carried out to obtain the diffusion coefficients of CO 2 in n-hexane, n-decane, n-hexadecane, cyclohexane, and squalane at temperatures up to 423.15 K and pressures up to 65 MPa. Three popular models were used for the representation of hydrocarbons: the united atom TraPPE (TraPPE-UA), the all-atom OPLS, and an optimized version of OPLS, namely, L-OPLS. All models qualitatively reproduce the pressure dependence of the diffusion coefficient of CO 2 in hydrocarbons measured recently, and L-OPLS was found to be the most accurate. Specifically for n-alkanes, L-OPLS also reproduced the measured viscosities and densities much more accurately than the original OPLS and TraPPE-UA models, indicating that the optimization of the torsional potential is crucial for the accurate description of transport properties of long chain molecules. The three force fields predict different microscopic properties such as the mean square radius of gyration for the n-alkane molecules and pair correlation functions for the CO 2 -n-alkane interactions. CO 2 diffusion coefficients in all hydrocarbons studied are shown to deviate significantly from the Stokes-Einstein behavior.

Constraining Gas Diffusivity-Soil Water Content Relationships in Forest Soils Using Surface Chamber Fluxes and Depth Profiles of Multiple Trace Gases

NASA Astrophysics Data System (ADS)

Dore, J. E.; Kaiser, K.; Seybold, E. C.; McGlynn, B. L.

2012-12-01

Forest soils are sources of carbon dioxide (CO2) to the atmosphere and can act as either sources or sinks of methane (CH4) and nitrous oxide (N2O), depending on redox conditions and other factors. Soil moisture is an important control on microbial activity, redox conditions and gas diffusivity. Direct chamber measurements of soil-air CO2 fluxes are facilitated by the availability of sensitive, portable infrared sensors; however, corresponding CH4 and N2O fluxes typically require the collection of time-course physical samples from the chamber with subsequent analyses by gas chromatography (GC). Vertical profiles of soil gas concentrations may also be used to derive CH4 and N2O fluxes by the gradient method; this method requires much less time and many fewer GC samples than the direct chamber method, but requires that effective soil gas diffusivities are known. In practice, soil gas diffusivity is often difficult to accurately estimate using a modeling approach. In our study, we apply both the chamber and gradient methods to estimate soil trace gas fluxes across a complex Rocky Mountain forested watershed in central Montana. We combine chamber flux measurements of CO2 (by infrared sensor) and CH4 and N2O (by GC) with co-located soil gas profiles to determine effective diffusivity in soil for each gas simultaneously, over-determining the diffusion equations and providing constraints on both the chamber and gradient methodologies. We then relate these soil gas diffusivities to soil type and volumetric water content in an effort to arrive at empirical parameterizations that may be used to estimate gas diffusivities across the watershed, thereby facilitating more accurate, frequent and widespread gradient-based measurements of trace gas fluxes across our study system. Our empirical approach to constraining soil gas diffusivity is well suited for trace gas flux studies over complex landscapes in general.

1. PARKING LOT AT GLACIER POINT. HALF DOME AT CENTER ...

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

1. PARKING LOT AT GLACIER POINT. HALF DOME AT CENTER REAR. LOOKING NE. GIS: N-36 43 45.8 / W-119 34 14.1 - Glacier Point Road, Between Chinquapin Flat & Glacier Point, Yosemite Village, Mariposa County, CA

Study of Diffusion Barrier for Solder/ n-Type Bi2Te3 and Bonding Strength for p- and n-Type Thermoelectric Modules

NASA Astrophysics Data System (ADS)

Lin, Wen-Chih; Li, Ying-Sih; Wu, Albert T.

2018-01-01

This paper investigates the interfacial reaction between Sn and Sn3Ag0.5Cu (SAC305) solder on n-type Bi2Te3 thermoelectric material. An electroless Ni-P layer successfully suppressed the formation of porous SnTe intermetallic compound at the interface. The formation of the layers between Bi2Te3 and Ni-P indicates that Te is the dominant diffusing species. Shear tests were conducted on both Sn and SAC305 solder on n- and p-type Bi2Te3 with and without a Ni-P barrier layer. Without a Ni-P layer, porous SnTe would result in a more brittle fracture. A comparison of joint strength for n- and p-type thermoelectric modules is evaluated by the shear test. Adding a diffusion barrier increases the mechanical strength by 19.4% in n-type and 74.0% in p-type thermoelectric modules.

Potential of pin-by-pin SPN calculations as an industrial reference

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fliscounakis, M.; Girardi, E.; Courau, T.

2012-07-01

This paper aims at analysing the potential of pin-by-pin SP{sub n} calculations to compute the neutronic flux in PWR cores as an alternative to the diffusion approximation. As far as pin-by-pin calculations are concerned, a SPH equivalence is used to preserve the reactions rates. The use of SPH equivalence is a common practice in core diffusion calculations. In this paper, a methodology to generalize the equivalence procedure in the SP{sub n} equations context is presented. In order to verify and validate the equivalence procedure, SP{sub n} calculations are compared to 2D transport reference results obtained with the APOLL02 code. Themore » validation cases consist in 3x3 analytical assembly color sets involving burn-up heterogeneities, UOX/MOX interfaces, and control rods. Considering various energy discretizations (up to 26 groups) and flux development orders (up to 7) for the SP{sub n} equations, results show that 26-group SP{sub 3} calculations are very close to the transport reference (with pin production rates discrepancies < 1%). This proves the high interest of pin-by-pin SP{sub n} calculations as an industrial reference when relying on 26 energy groups combined with SP{sub 3} flux development order. Additionally, the SP{sub n} results are compared to diffusion pin-by-pin calculations, in order to evaluate the potential benefit of using a SP{sub n} solver as an alternative to diffusion. Discrepancies on pin-production rates are less than 1.6% for 6-group SP{sub 3} calculations against 3.2% for 2-group diffusion calculations. This shows that SP{sub n} solvers may be considered as an alternative to multigroup diffusion. (authors)« less

Diwu Yanggan capsule improving liver histological response for patients with HBeAg-negative chronic hepatitis B: a randomized controlled clinical trial.

PubMed

Li, Hanmin; Ye, Zhihua; Gao, Xiang; Zhang, Lisheng; Yao, Xin; Gu, Jianxun; Lu, Dingbo; Wan, Ming; Xiao, Lin; Cai, Wangxi; Yan, Xuesheng; Zhao, Binbin; Wu, Yu; Zhang, Jinrong

2018-01-01

The number of patients with hepatitis B e antigen (HBeAg)-negative chronic hepatitis B (CHB) has shown a significant upward trend in recent years. However, antiviral drugs are not very effective. Regulation of liver regeneration by traditional Chinese medicine is an important way to improve clinical efficacy. This randomized controlled trial assessed the efficacy and safety of DWYG in patients with HBeAg-negative CHB. Overall, 130 subjects were randomized to (A) DWYG 1.2 g three times daily (n = 44), (B) entecavir 0.5 mg/day (n = 43) in combination with DWYG or (C) entecavir 0.5 mg/day (n = 43). The liver histological response rate was assessed as the primary efficacy endpoint. The results showed that the liver histological response rate in the combination treatment group was significantly higher than that in the group with entecavir (71.43% versus 22.22%; P = 0.036) after 48 weeks of treatment. And the pathological progression rate of liver in the group with DWYG was significantly lower than that of the entecavir group during 228 weeks of follow-up (0% versus 60.00%; P = 0.019). No significant adverse events occurred during the study. In conclusion, treating HBeAg-negative CHB with DWYG is safe and effective to improve liver histological response.

Diffusion coefficients significant in modeling the absorption rate of carbon dioxide into aqueous blends of N-methyldiethanolamine and diethanolamine and of hydrogen sulfide into aqueous N-methyldiethanolamine

DOE Office of Scientific and Technical Information (OSTI.GOV)

Adams, M.E.; Marshall, T.L.; Rowley, R.L.

1998-07-01

Absorption rates of gaseous CO{sub 2} into aqueous blends of N-methyldiethanolamine (MDEA) and diethanolamine (DEA) and of gaseous H{sub 2}S into aqueous MDEA were measured in a quiescent, inverted-tube diffusiometer by monitoring the rate of pressure drop. A numerical model for absorption, diffusion, and reaction of CO{sub 2} and H{sub 2}S in blends of MDEA, DEA, and water was developed. The model was used to regress diffusion coefficients of bicarbonate, carbamate, and MDEAH{sub 2}CO{sub 3} for the case of CO{sub 2} absorption and of bisulfide ion for the case of H{sub 2}S absorption from measured absorption rates. CO{sub 2} absorptionmore » rates and diffusion coefficients of bicarbonate, carbamate, and MDEAH{sub 2}CO{sub 3} were obtained at 298.2 K and 318.2 K in aqueous solutions containing 50 mass % total amine at DEA:MDEA mole ratios of 1:20, 1:4, 1L3, and 2:3. H{sub 2}S absorption rates and diffusion coefficients of bisulfide ion were obtained at 298.2 K and 318.2 K in aqueous solutions containing 20, 35, and 50 mass % MDEA.« less

75 FR 41237 - Public Land Order No. 7746; Withdrawal of Public Lands, South Fork of the American River; California

Federal Register 2010, 2011, 2012, 2013, 2014

2010-07-15

... the American River: Mount Diablo Meridian T. 11 N., R. 9 E., Sec. 10, NW\\1/4\\NW\\1/4\\ and S\\1/2\\; Sec...\\,SW\\1/4\\, and SE\\1/4\\; Sec. 32, N\\1/2\\NE\\1/4\\, SW\\1/4\\NE\\1/4\\, W\\1/2\\, and S\\1/2\\SE\\1/ 4\\. T. 11 N., R. 10 E., Sec. 18, lots 5, 6, and 7, and NW\\1/4\\NE\\1/4\\NW\\1/4\\; Sec. 22, NW\\1/4\\SE\\1/4\\SW\\1/4\\, and that...

Performance of the EUCAST Disk Diffusion Method, the CLSI Agar Screen Method, and the Vitek 2 Automated Antimicrobial Susceptibility Testing System for Detection of Clinical Isolates of Enterococci with Low- and Medium-Level VanB-Type Vancomycin Resistance: a Multicenter Study

PubMed Central

Giske, Christian G.; Haldorsen, Bjørg; Matuschek, Erika; Schønning, Kristian; Leegaard, Truls M.; Kahlmeter, Gunnar

2014-01-01

Different antimicrobial susceptibility testing methods to detect low-level vancomycin resistance in enterococci were evaluated in a Scandinavian multicenter study (n = 28). A phenotypically and genotypically well-characterized diverse collection of Enterococcus faecalis (n = 12) and Enterococcus faecium (n = 18) strains with and without nonsusceptibility to vancomycin was examined blindly in Danish (n = 5), Norwegian (n = 13), and Swedish (n = 10) laboratories using the EUCAST disk diffusion method (n = 28) and the CLSI agar screen (n = 18) or the Vitek 2 system (bioMérieux) (n = 5). The EUCAST disk diffusion method (very major error [VME] rate, 7.0%; sensitivity, 0.93; major error [ME] rate, 2.4%; specificity, 0.98) and CLSI agar screen (VME rate, 6.6%; sensitivity, 0.93; ME rate, 5.6%; specificity, 0.94) performed significantly better (P = 0.02) than the Vitek 2 system (VME rate, 13%; sensitivity, 0.87; ME rate, 0%; specificity, 1). The performance of the EUCAST disk diffusion method was challenged by differences in vancomycin inhibition zone sizes as well as the experience of the personnel in interpreting fuzzy zone edges as an indication of vancomycin resistance. Laboratories using Oxoid agar (P < 0.0001) or Merck Mueller-Hinton (MH) agar (P = 0.027) for the disk diffusion assay performed significantly better than did laboratories using BBL MH II medium. Laboratories using Difco brain heart infusion (BHI) agar for the CLSI agar screen performed significantly better (P = 0.017) than did those using Oxoid BHI agar. In conclusion, both the EUCAST disk diffusion and CLSI agar screening methods performed acceptably (sensitivity, 0.93; specificity, 0.94 to 0.98) in the detection of VanB-type vancomycin-resistant enterococci with low-level resistance. Importantly, use of the CLSI agar screen requires careful monitoring of the vancomycin concentration in the plates. Moreover, disk diffusion methodology requires that personnel be trained in interpreting zone edges. PMID:24599985

Measurement of diffusion coefficients important in modeling the absorption rate of carbon dioxide into aqueous N-methyldiethanolamine

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rowley, R.L.; Adams, M.E.; Marshall, T.L.

1997-03-01

Natural gas processors use amine treating processes to remove the acid gases H{sub 2}S and CO{sub 2} from gas streams. Absorption rates of gaseous CO{sub 2} into aqueous N-methyldiethanolamine (MDEA) solutions were measured in a quiescent, inverted-tube diffusiometer by monitoring the rate of pressure drop. The absorption rate was found to be insensitive to the diffusion coefficient of CO{sub 2} in solution but very sensitive to the diffusion rate of bicarbonate and protonated MDEA ions. Evidence also suggested that chemical reaction equilibrium is rapid relative to diffusion. A numerical model was developed on the basis of these observations. The modelmore » was used to regress diffusion coefficients of bicarbonate and protonated amine, which must be equivalent by electroneutrality arguments, from measured absorption rates. Complete modeling of the absorption process also required data for the diffusion coefficient of MDEA in water. These were measured using a Taylor dispersion apparatus. CO{sub 2} absorption rates and diffusion coefficients of bicarbonate and protonated MDEA were obtained at 298.2 K and 318.2 K in solutions containing 20, 35, and 50 mass % MDEA in water.« less

Galaxy collisions as a mechanism of ultra diffuse galaxy (UDG) formation

NASA Astrophysics Data System (ADS)

Baushev, A. N.

2018-04-01

We suggest a possible mechanism of ultra diffuse galaxy formation: the UDGs may occur as a result of a central collision of galaxies. If the galaxies are young and contain a lot of gas, the collision may kick all the gas off the systems and thus strongly suppress any further star formation. As a result, the galaxies now have a very low surface brightness and other properties typical of the ultra diffuse galaxies. We use the Coma cluster (where numerous UDGs were recently discovered) to test the efficiency of the process. The mechanism works very well and can transform a significant fraction of the cluster population into ultra diffuse galaxies. The UDGs formed by the process concentrate towards the center of the cluster, and their globular cluster systems remain undamaged, in accordance with observational results. The projected surface density of UDGs in the cluster may help us to recognize the mechanism of UDG formation, or clarify relative contributions of several possible competitive mechanisms at work.

Cu diffusion in single-crystal and polycrystalline TiN barrier layers: A high-resolution experimental study supported by first-principles calculations

NASA Astrophysics Data System (ADS)

Mühlbacher, Marlene; Bochkarev, Anton S.; Mendez-Martin, Francisca; Sartory, Bernhard; Chitu, Livia; Popov, Maxim N.; Puschnig, Peter; Spitaler, Jürgen; Ding, Hong; Schalk, Nina; Lu, Jun; Hultman, Lars; Mitterer, Christian

2015-08-01

Dense single-crystal and polycrystalline TiN/Cu stacks were prepared by unbalanced DC magnetron sputter deposition at a substrate temperature of 700 °C and a pulsed bias potential of -100 V. The microstructural variation was achieved by using two different substrate materials, MgO(001) and thermally oxidized Si(001), respectively. Subsequently, the stacks were subjected to isothermal annealing treatments at 900 °C for 1 h in high vacuum to induce the diffusion of Cu into the TiN. The performance of the TiN diffusion barrier layers was evaluated by cross-sectional transmission electron microscopy in combination with energy-dispersive X-ray spectrometry mapping and atom probe tomography. No Cu penetration was evident in the single-crystal stack up to annealing temperatures of 900 °C, due to the low density of line and planar defects in single-crystal TiN. However, at higher annealing temperatures when diffusion becomes more prominent, density-functional theory calculations predict a stoichiometry-dependent atomic diffusion mechanism of Cu in bulk TiN, with Cu diffusing on the N sublattice for the experimental N/Ti ratio. In comparison, localized diffusion of Cu along grain boundaries in the columnar polycrystalline TiN barriers was detected after the annealing treatment. The maximum observed diffusion length was approximately 30 nm, yielding a grain boundary diffusion coefficient of the order of 10-16 cm2 s-1 at 900 °C. This is 10 to 100 times less than for comparable underdense polycrystalline TiN coatings deposited without external substrate heating or bias potential. The combined numerical and experimental approach presented in this paper enables the contrasting juxtaposition of diffusion phenomena and mechanisms in two TiN coatings, which differ from each other only in the presence of grain boundaries.

Finite-time blow-up for quasilinear degenerate Keller-Segel systems of parabolic-parabolic type

NASA Astrophysics Data System (ADS)

Hashira, Takahiro; Ishida, Sachiko; Yokota, Tomomi

2018-05-01

This paper deals with the quasilinear degenerate Keller-Segel systems of parabolic-parabolic type in a ball of RN (N ≥ 2). In the case of non-degenerate diffusion, Cieślak-Stinner [3,4] proved that if q > m + 2/N, where m denotes the intensity of diffusion and q denotes the nonlinearity, then there exist initial data such that the corresponding solution blows up in finite time. As to the case of degenerate diffusion, it is known that a solution blows up if q > m + 2/N (see Ishida-Yokota [13]); however, whether the blow-up time is finite or infinite has been unknown. This paper gives an answer to the unsolved problem. Indeed, the finite-time blow-up of energy solutions is established when q > m + 2/N.

25MM Plastic Telescoped Cartridge Case Development Program

DTIC Science & Technology

1975-01-01

Mat’ I____ Projectile: 0wq. No. 30033;7,Rev, A, Platic "Band, 3000 Grain. Primer: Type .SmL. , Lot No.,, , Ne. . Flash Tubet.l3TSpe 1ell Project l...8217 _ ’_"__ Projectile: Dwg. No. 300347, Ray. A, Platic Biand, 3000 Graln. Primer: Type P-SIT.ML , Lot No. . No, Flash Tube:c<# 7’Tr-pecla1, Projectile Rot ntlo...Case: N ,o Rev. ___, Mati:.l, ILt Dwg. No,._____ Rev. M Nt l______Projectile: Dwg, No. 300347, ev • A, Platic ’ t -and, 3000 Grain, Primers Type , Lot

Flat-plate solar array project process development area, process research of non-CZ silicon material

NASA Technical Reports Server (NTRS)

Campbell, R. B.

1984-01-01

The program is designed to investigate the fabrication of solar cells on N-type base material by a simultaneous diffusion of N-type and P-type dopants to form an P(+)NN(+) structure. The results of simultaneous diffusion experiments are being compared to cells fabricated using sequential diffusion of dopants into N-base material in the same resistivity range. The process used for the fabrication of the simultaneously diffused P(+)NN(+) cells follows the standard Westinghouse baseline sequence for P-base material except that the two diffusion processes (boron and phosphorus) are replaced by a single diffusion step. All experiments are carried out on N-type dendritic web grown in the Westinghouse pre-pilot facility. The resistivities vary from 0.5 (UC OMEGA)cm to 5 (UC OMEGA)cm. The dopant sources used for both the simultaneous and sequential diffusion experiments are commercial metallorganic solutions with phosphorus or boron components. After these liquids are applied to the web surface, they are baked to form a hard glass which acts as a diffusion source at elevated temperatures. In experiments performed thus far, cells produced in sequential diffusion tests have properties essentially equal to the baseline N(+)PP(+) cells. However, the simultaneous diffusions have produced cells with much lower IV characteristics mainly due to cross-doping of the sources at the diffusion temperature. This cross-doping is due to the high vapor pressure phosphorus (applied as a metallorganic to the back surface) diffusion through the SiO2 mask and then acting as a diffusant source for the front surface.

Predicting pneumonitis risk: a dosimetric alternative to mean lung dose.

PubMed

Tucker, Susan L; Mohan, Radhe; Liengsawangwong, Raweewan; Martel, Mary K; Liao, Zhongxing

2013-02-01

To determine whether the association between mean lung dose (MLD) and risk of severe (grade ≥3) radiation pneumonitis (RP) depends on the dose distribution pattern to normal lung among patients receiving 3-dimensional conformal radiation therapy for non-small-cell lung cancer. Three cohorts treated with different beam arrangements were identified. One cohort (2-field boost [2FB]) received 2 parallel-opposed (anteroposterior-posteroanterior) fields per fraction initially, followed by a sequential boost delivered using 2 oblique beams. The other 2 cohorts received 3 or 4 straight fields (3FS and 4FS, respectively), ie, all fields were irradiated every day. The incidence of severe RP was plotted against MLD in each cohort, and data were analyzed using the Lyman-Kutcher-Burman (LKB) model. The incidence of grade ≥3 RP rose more steeply as a function of MLD in the 2FB cohort (N=120) than in the 4FS cohort (N=138), with an intermediate slope for the 3FS group (N=99). The estimated volume parameter from the LKB model was n=0.41 (95% confidence interval, 0.15-1.0) and led to a significant improvement in fit (P=.05) compared to a fit with volume parameter fixed at n=1 (the MLD model). Unlike the MLD model, the LKB model with n=0.41 provided a consistent description of the risk of severe RP in all three cohorts (2FB, 3FS, 4FS) simultaneously. When predicting risk of grade ≥3 RP, the mean lung dose does not adequately take into account the effects of high doses. Instead, the effective dose, computed from the LKB model using volume parameter n=0.41, may provide a better dosimetric parameter for predicting RP risk. If confirmed, these findings support the conclusion that for the same MLD, high doses to small lung volumes ("a lot to a little") are worse than low doses to large volumes ("a little to a lot"). Copyright © 2013 Elsevier Inc. All rights reserved.

Comparison of Apparent Diffusion Coefficient and Intravoxel Incoherent Motion for Differentiating among Glioblastoma, Metastasis, and Lymphoma Focusing on Diffusion-Related Parameter.

PubMed

Shim, Woo Hyun; Kim, Ho Sung; Choi, Choong-Gon; Kim, Sang Joon

2015-01-01

Brain tumor cellularity has been assessed by using apparent diffusion coefficient (ADC). However, the ADC value might be influenced by both perfusion and true molecular diffusion, and the perfusion effect on ADC can limit the reliability of ADC in the characterization of tumor cellularity, especially, in hypervascular brain tumors. In contrast, the IVIM technique estimates parameter values for diffusion and perfusion effects separately. The purpose of our study was to compare ADC and IVIM for differentiating among glioblastoma, metastatic tumor, and primary CNS lymphoma (PCNSL) focusing on diffusion-related parameter. We retrospectively reviewed the data of 128 patients with pathologically confirmed glioblastoma (n = 55), metastasis (n = 31), and PCNSL (n = 42) prior to any treatment. Two neuroradiologists independently calculated the maximum IVIM-f (fmax) and minimum IVIM-D (Dmin) by using 16 different b-values with a bi-exponential fitting of diffusion signal decay, minimum ADC (ADCmin) by using 0 and 1000 b-values with a mono-exponential fitting and maximum normalized cerebral blood volume (nCBVmax). The differences in fmax, Dmin, nCBVmax, and ADCmin among the three tumor pathologies were determined by one-way ANOVA with multiple comparisons. The fmax and Dmin were correlated to the corresponding nCBV and ADC using partial correlation analysis, respectively. Using a mono-exponential fitting of diffusion signal decay, the mean ADCmin was significantly lower in PCNSL than in glioblastoma and metastasis. However, using a bi-exponential fitting, the mean Dmin did not significantly differ in the three groups. The mean fmax significantly increased in the glioblastomas (reader 1, 0.103; reader 2, 0.109) and the metastasis (reader 1, 0.105; reader 2, 0.107), compared to the primary CNS lymphomas (reader 1, 0.025; reader 2, 0.023) (P < .001 for each). The correlation between fmax and the corresponding nCBV was highest in glioblastoma group, and the correlation between Dmin and the corresponding ADC was highest in primary CNS lymphomas group. Unlike ADC value derived from a mono-exponential fitting of diffusion signal, diffusion-related parametric value derived from a bi-exponential fitting with separation of perfusion effect doesn't differ among glioblastoma, metastasis, and PCNSL.

Space logistics simulation: Launch-on-time

NASA Technical Reports Server (NTRS)

Nii, Kendall M.

1990-01-01

During 1989-1990 the Center for Space Construction developed the Launch-On-Time (L-O-T) Model to help asses and improve the likelihood of successfully supporting space construction requiring multi-logistic delivery flights. The model chose a reference by which the L-O-T probability and improvements to L-O-T probability can be judged. The measure of improvement was chosen as the percent reduction in E(S(sub N)), the total expected amount of unscheduled 'hold' time. We have also previously developed an approach to determining the reduction in E(S(sub N)) by reducing some of the causes of unscheduled holds and increasing the speed at which the problems causing the holds may be 'fixed.' We provided a mathematical (binary linear programming) model for measuring the percent reduction in E(S(sub N)) given such improvements. In this presentation we shall exercise the model which was developed and draw some conclusions about the following: methods used, data available and needed, and make suggestions for areas of improvement in 'real world' application of the model.

Experimental study of mass diffusion coefficients of hydrogen in dimethyl phosphate and n-heptane

NASA Astrophysics Data System (ADS)

Guo, Y.; Zhu, L. K.; Zhang, Y. P.; Liu, J.; Guo, J. S.

2017-11-01

In this study, a laser holographic interferometer experimental system was developed for studying the gas-liquid mass diffusion coefficient. Then the experimental system’s uncertainty was analyzed to be at most ±0.2% therefore, this system was reliable. The mass diffusion coefficient of hydrogen in dimethyl phosphate and n-heptane was measured at atmospheric pressure in the temperature range of 273.15-338.15 K. Then, the experimental data were used to fit the correlations of the mass diffusion coefficient of hydrogen in dimethyl phosphate and n-heptane with temperature.

Molecular modeling of polymers 16. Gaseous diffusion in polymers: a quantitative structure-property relationship (QSPR) analysis.

PubMed

Patel, H C; Tokarski, J S; Hopfinger, A J

1997-10-01

The purpose of this study was to identify the key physicochemical molecular properties of polymeric materials responsible for gaseous diffusion in the polymers. Quantitative structure-property relationships, QSPRs were constructed using a genetic algorithm on a training set of 16 polymers for which CO2, N2, O2 diffusion constants were measured. Nine physicochemical properties of each of the polymers were used in the trial basis set for QSPR model construction. The linear cross-correlation matrices were constructed and investigated for colinearity among the members of the training sets. Common water diffusion measures for a limited training set of six polymers was used to construct a "semi-QSPR" model. The bulk modulus of the polymer was overwhelmingly found to be the dominant physicochemical polymer property that governs CO2, N2 and O2 diffusion. Some secondary physicochemical properties controlling diffusion, including conformational entropy, were also identified as correlation descriptors. Very significant QSPR diffusion models were constructed for all three gases. Cohesive energy was identified as the main correlation physicochemical property with aqueous diffusion measures. The dominant role of polymer bulk modulus on gaseous diffusion makes it difficult to develop criteria for selective transport of gases through polymers. Moreover, high bulk moduli are predicted to be necessary for effective gas barrier materials. This property requirement may limit the processing and packaging features of the material. Aqueous diffusion in polymers may occur by a different mechanism than gaseous diffusion since bulk modulus does not correlate with aqueous diffusion, but rather cohesive energy of the polymer.

Correlated diffusion of colloidal particles near a liquid-liquid interface.

PubMed

Zhang, Wei; Chen, Song; Li, Na; Zhang, Jia Zheng; Chen, Wei

2014-01-01

Optical microscopy and multi-particle tracking are used to investigate the cross-correlated diffusion of quasi two-dimensional colloidal particles near an oil-water interface. The behaviors of the correlated diffusion along longitudinal and transverse direction are asymmetric. It is shown that the characteristic length for longitudinal and transverse correlated diffusion are particle diameter d and the distance z from particle center to the interface, respectively, for large particle separation z. The longitudinal and transverse correlated diffusion coefficient D||(r) and D[perpendicular](r) are independent of the colloidal area fraction n when n < 0.3, which indicates that the hydrodynamic interactions(HIs) among the particles are dominated by HIs through the surrounding fluid for small n. For high area fraction n > 0.4 the power law exponent for the spatial decay of [Formula: see text] begins to decrease, which suggests the HIs are more contributed from the 2D particle monolayer self for large n.

Charge disproportionation in tetragonal La2MoO5, a small band gap semiconductor influenced by direct Mo-Mo bonding.

PubMed

Colabello, Diane M; Camino, Fernando E; Huq, Ashfia; Hybertsen, Mark; Khalifah, Peter G

2015-01-28

The structure of the novel compound La2MoO5 has been solved from powder X-ray and neutron diffraction data and belongs to the tetragonal space group P4/m (no. 83) with a = 12.6847(3) Å and c = 6.0568(2) Å and with Z = 8. It consists of equal proportions of bioctahedral (Mo2O10) and square prismatic (Mo2O8) dimers, both of which contain direct Mo-Mo bonds and are arranged in 1D chains. The Mo-Mo bond length in the Mo2O10 dimers is 2.684(8) Å, while there are two types of Mo2O8 dimers with Mo-Mo bonds lengths of 2.22(2) and 2.28(2) Å. Although the average Mo oxidation state in La2MoO5 is 4+, the very different Mo-Mo distances reflect the fact that the Mo2O10 dimers contain only Mo(5+) (d(1)), while the prismatic Mo2O8 dimers only contain Mo(3+) (d(3)), a result directly confirmed by density function theory calculations. This is due to the complete disproportionation of Mo(4+), a phenomenon which has not previously been observed in solid-state compounds. La2MoO5 is diamagnetic, behavior which is not expected for a nonmetallic transition-metal oxide whose cation sites have an odd number of d-electrons. The resistivity displays the Arrhenius-type activated behavior expected for a semiconductor with a band gap of 0.5 eV, exhibiting an unusually small transport gap relative to other diamagnetic oxides. Diffuse reflectance studies indicate that La2MoO5 is a rare example of a stable oxide semiconductor with strong infrared absorbance. It is shown that the d-orbital splitting associated with the Mo2O8 and Mo2O10 dimeric units can be rationalized using simple molecular orbital bonding concepts.

Alternative Fuels Data Center

Science.gov Websites

-4730 U.S. Internal Revenue Service Phone: (800) 829-1040 Federal Trade Commission Phone: (202) 326-2222 Excise Tax Branch U.S. Internal Revenue Service Office of Chief Counsel Phone: (202) 317-6855 U.S

Multipoint anchoring of the [2.2.2.2]metacyclophane motif to a gold surface via self-assembly: coordination chemistry of a cyclic tetraisocyanide revisited.

PubMed

Toriyama, Masaharu; Maher, Tiffany R; Holovics, Thomas C; Vanka, Kumar; Day, Victor W; Berrie, Cindy L; Thompson, Ward H; Barybin, Mikhail V

2008-04-21

A one-pot transformation of bis(2-isocyano-3-methylphenyl)ethane affords gram quantities of 8,16,24,32-tetraisocyano[2.2.2.2]metacyclophane ( 3). The solid state structure of 3 is remarkably close to the lowest energy conformation found on the potential energy landscape for 3 by DFT. In solution, the structure of metacyclophane 3 is mobile but can be locked in a rectangular gauche- anti- gauche- anti conformation by coordination of the isocyanide substituents to the [W(CO) 5] units to give [M] 4(mu 4-eta (1):eta (1):eta (1):eta (1)- 3) ( 5). The tetranuclear [M] 4(mu 4-eta (1):eta (1):eta (1):eta (1)- 3) motif featured in crystallographically characterized 5 may be present in several insoluble complexes of 3 previously described as mononuclear eta (4) species. A self-assembled monolayer of metacyclophane 3 is formed upon exposing a solution of 3 to the gold(111) surface with no precautions to exclude air or light. The monolayer nature of the film was confirmed by optical ellipsometry. The isocyanide stretching band for 3 shifts from 2119 cm (-1) in solution to 2175 cm (-1) upon chemisorption to metallic gold. The FTIR spectrum of the film indicates interaction of 3 with the gold surface via all four of its isocyanide anchors. No gold-facilitated oxidation of the -NC junctions was detected under ambient conditions. The energy cost associated with accessing the conformations of 3 suitable for mu 4-eta (1):eta (1):eta (1):eta (1) interaction of the molecule with the Au(111) surface is under 8 kcal/mol, a value that can be easily offset by formation of a gold-isocyanide bond. Two different mu 4-eta (1):eta (1):eta (1):eta (1) coordination arrangements of 3 with respect to gold atoms on the (111) face of the fcc Au lattice are suggested.

Soil Quality Assessment Is a Necessary First Step for Designing Urban Green Infrastructure.

PubMed

Montgomery, James A; Klimas, Christie A; Arcus, Joseph; DeKnock, Christian; Rico, Kathryn; Rodriguez, Yarency; Vollrath, Katherine; Webb, Ellen; Williams, Allison

2016-01-01

This paper describes the results of a preliminary project conducted by a team of DePaul University undergraduate students and staff from the Gary Comer Youth Center located on Chicago's South Side. The team assessed soil quality on 116 samples collected among four abandoned residential lots adjacent to the Comer Center. Soil quality data will be used in a follow-up study to determine the suitability of each lot for green infrastructure implementation. Green infrastructure may be a useful approach for providing ecosystem services and mitigating food deserts in inner-city communities. Soil quality on all lots was poor. All soils had pH >8.0, low biological activity, and low N mineralization potential. The soils were rich in available P and had mean total Pb concentrations above the USEPA threshold (400 mg kg) for children's playlots. Mean bioavailable Pb on the largest of the four lots was 12% of total Pb, indicating that most of the total Pb is not bioavailable. This result is encouraging because high bioavailable Pb concentrations are linked with negative health effects, particularly in children. All lots had NO-N concentrations below those considered to be appropriate for plant growth. On the other hand, no significant differences in mean concentrations of the other analytes were found. The poor soil quality in the four lots presents an opportunity to use green infrastructure to enhance ecosystem services, improve community and environmental health, and provide more equitable access to green space. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Investigating the validity of the Knudsen prescription for diffusivities in a mesoporous covalent organic framework

DOE Office of Scientific and Technical Information (OSTI.GOV)

Krishna, Rajamani; van Baten, Jasper M.

2011-04-27

Molecular dynamics (MD) simulations were performed to determine the self-diffusivity (D i,self) and the Maxwell–Stefan diffusivity (Ð I) of hydrogen, argon, carbon dioxide, methane, ethane, propane, n-butane, n-pentane, and n-hexane in BTP-COF, which is a covalent organic framework (COF) that has one-dimensional 3.4-nm-sized channels. The MD simulations show that the zero-loading diffusivity (Ð I(0)) is consistently lower, by up to a factor of 10, than the Knudsen diffusivity (D i,Kn) values. The ratio Ð I(0)/D i,Kn is found to correlate with the isosteric heat of adsorption, which, in turn, is a reflection of the binding energy for adsorption on themore » pore walls: the stronger the binding energy, the lower the ratio Ð I(0)/D i,Kn. The diffusion selectivity, which is defined by the ratio D 1,self/D 2,self for binary mixtures, was determined to be significantly different from the Knudsen selectivity (M 2/M 1) 1/2, where M I is the molar mass of species i. For mixtures in which component 2 is more strongly adsorbed than component 1, the expression (D 1,self/D 2,self)/(M 2/M 1)1/2 has values in the range of 1–10; the departures from the Knudsen selectivity increased with increasing differences in adsorption strengths of the constituent species. The results of this study have implications in the modeling of diffusion within mesoporous structures, such as MCM-41 and SBA-15.« less

Diffusivity of nitrous oxide in aqueous solutions of N-methyldiethanolamine and diethanolamine from 293 to 368 K

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tamimi, A.; Rinker, E.B.; Sandall, O.C.

1994-04-01

The diffusion coefficients for nitrous oxide in aqueous solutions of diethanolamine (DEA) and N-methyldiethanolamine (MDEA) were determined using a wetted-sphere absorber over the temperature range 293--368 K. The ranges of amine concentrations covered in the experiments were 10--30 mass % for DEA and 10--50 mass % for MDEA. The diffusion coefficients indicated a linear dependence on amine concentration, but the temperature dependence was nonlinear. It was found that the diffusivity of N[sub 2]O in aqueous DEA is always less than that in aqueous MDEA under equivalent conditions of amine concentration and temperature.

First-principles binary diffusion coefficients for H, H 2 and four normal alkanes + N 2

DOE PAGES

Jasper, Ahren W.; Kamarchik, Eugene; Miller, James A.; ...

2014-09-30

Collision integrals related to binary (dilute gas) diffusion are calculated classically for six species colliding with N 2. The most detailed calculations make no assumptions regarding the complexity of the potential energy surface, and the resulting classical collision integrals are in excellent agreement with previous semiclassical results for H + N 2 and H 2 + N 2 and with recent experimental results for C n H 2n+2 + N 2, n = 2–4. The detailed classical results are used to test the accuracy of three simplifying assumptions typically made when calculating collision integrals: (1) approximating the intermolecular potential asmore » isotropic, (2) neglecting the internal structure of the colliders (i.e., neglecting inelasticity), and (3) employing unphysical R –12 repulsive interactions. The effect of anisotropy is found to be negligible for H + N 2 and H 2 + N 2 (in agreement with previous quantum mechanical and semiclassical results for systems involving atomic and diatomic species) but is more significant for larger species at low temperatures. For example, the neglect of anisotropy decreases the diffusion coefficient for butane + N 2 by 15% at 300 K. The neglect of inelasticity, in contrast, introduces only very small errors. Approximating the repulsive wall as an unphysical R –12 interaction is a significant source of error at all temperatures for the weakly interacting systems H + N 2 and H 2 + N 2, with errors as large as 40%. For the normal alkanes in N 2, which feature stronger interactions, the 12/6 Lennard–Jones approximation is found to be accurate, particularly at temperatures above –700 K where it predicts the full-dimensional result to within 5% (although with somewhat different temperature dependence). Overall, the typical practical approach of assuming isotropic 12/6 Lennard–Jones interactions is confirmed to be suitable for combustion applications except for weakly interacting systems, such as H + N 2. For these systems, anisotropy and inelasticity can safely be neglected but a more detailed description of the repulsive wall is required for quantitative predictions. Moreover, a straightforward approach for calculating effective isotropic potentials with realistic repulsive walls is described. An analytic expression for the calculated diffusion coefficient for H + N 2 is presented and is estimated to have a 2-sigma error bar of only 0.7%.« less

SDSS J2222+2745: A GRAVITATIONALLY LENSED SEXTUPLE QUASAR WITH A MAXIMUM IMAGE SEPARATION OF 15.''1 DISCOVERED IN THE SLOAN GIANT ARCS SURVEY

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dahle, H.; Groeneboom, N.; Gladders, M. D.

2013-08-20

We report the discovery of a unique gravitational lens system, SDSS J2222+2745, producing five spectroscopically confirmed images of a z{sub s} = 2.82 quasar lensed by a foreground galaxy cluster at z{sub l} = 0.49. We also present photometric and spectroscopic evidence for a sixth lensed image of the same quasar. The maximum separation between the quasar images is 15.''1. Both the large image separations and the high image multiplicity are in themselves rare among known lensed quasars, and observing the combination of these two factors is an exceptionally unlikely occurrence in present data sets. This is only the thirdmore » known case of a quasar lensed by a cluster, and the only one with six images. The lens system was discovered in the course of the Sloan Giant Arcs Survey, in which we identify candidate lenses in the Sloan Digital Sky Survey and target these for follow-up and verification with the 2.56 m Nordic Optical Telescope. Multi-band photometry obtained over multiple epochs from 2011 September to 2012 September reveals significant variability at the {approx}10%-30% level in some of the quasar images, indicating that measurements of the relative time delay between quasar images will be feasible. In this lens system, we also identify a bright (g = 21.5) giant arc corresponding to a strongly lensed background galaxy at z{sub s} = 2.30. We fit parametric models of the lens system, constrained by the redshift and positions of the quasar images and the redshift and position of the giant arc. The predicted time delays between different pairs of quasar images range from {approx}100 days to {approx}6 yr.« less

Diffusion of protein through the human cornea.

PubMed

Charalel, Resmi A; Engberg, Kristin; Noolandi, Jaan; Cochran, Jennifer R; Frank, Curtis; Ta, Christopher N

2012-01-01

To determine the rate of diffusion of myoglobin and bovine serum albumin (BSA) through the human cornea. These small proteins have hydrodynamic diameters of approximately 4.4 and 7.2 nm, and molecular weights of 16.7 and 66 kDa, for myoglobin and BSA, respectively. Diffusion coefficients were measured using a diffusion chamber where the protein of interest and balanced salt solution were in different chambers separated by an ex vivo human cornea. Protein concentrations in the balanced salt solution chamber were measured over time. Diffusion coefficients were calculated using equations derived from Fick's law and conservation of mass in a closed system. Our experiments demonstrate that the diffusion coefficient of myoglobin is 5.5 ± 0.9 × 10(-8) cm(2)/s (n = 8; SD = 1.3 × 10(-8) cm(2)/s; 95% CI: 4.6 × 10(-8) to 6.4 × 10(-8) cm(2)/s) and the diffusion coefficient of BSA is 3.1 ± 1.0 × 10(-8) cm(2)/s (n = 8; SD = 1.4 × 10(-8) cm(2)/s; 95% CI: 2.1 × 10(-8) to 4.1 × 10(-8) cm(2)/s). Our study suggests that molecules as large as 7.2 nm may be able to passively diffuse through the human cornea. With applications in pharmacotherapy and the development of an artificial cornea, further experiments are warranted to fully understand the limits of human corneal diffusion and its clinical relevance. Copyright © 2012 S. Karger AG, Basel.

Diffusivity of nitrous oxide in N-methyldiethanolamine + diethanolamine + water

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rinker, E.B.; Russell, J.W.; Tamimi, A.

1995-05-01

The tertiary amine N-methyldiethanolamine and the secondary amine diethanolamine are commonly used in the gas-treating industry as chemical solvents for the removal of acid gases such as CO{sub 2} and H{sub 2}S. The diffusion coefficients for nitrous oxide in aqueous solutions consisting of N-methyldiethanolamine (MDEA) and diethanolamine (DEA) were measured over the temperature range 293--353 K for a total amine concentration of 50 mass % and for the mass ratio of DEA to MDEA varying from 0.0441 to 0.588. The experimental diffusion coefficients were found to be relatively insensitive to the mass ratio of amines.

Automated Quality of Care Evaluation Support System (AQCESS): AQCESS System Specification

DTIC Science & Technology

1985-03-29

11, 1974, by the Department of Defense Assistant Secretaries of Defense ( Com - ptroller, and Health and Environment). The program is now managed and...xx TIME xNxx 11 21 PERSONAL DATA - PRIVACY ACT OF 1974 12 3INAME xxm x SEX xFMP xx SSN xx DOD xx 13...00 -2 2 M.U.&.0I I , 0WU 0 w Z. C 009 t0 _j11M.w :.0 -2222 Com 444444444 WWIMWWWW W4, z ca c cc c 94 (Z0=00 I.1, a QK0W W W U L A. W 4f-c4IWUcc I 1 I

Broiler Campylobacter Contamination and Human Campylobacteriosis in Iceland ▿ †

PubMed Central

Callicott, Kenneth A.; Harðardóttir, Hjördís; Georgsson, Franklín; Reiersen, Jarle; Friðriksdóttir, Vala; Gunnarsson, Eggert; Michel, Pascal; Bisaillon, Jean-Robert; Kristinsson, Karl G.; Briem, Haraldur; Hiett, Kelli L.; Needleman, David S.; Stern, Norman J.

2008-01-01

To examine whether there is a relationship between the degree of Campylobacter contamination observed in product lots of retail Icelandic broiler chicken carcasses and the incidence of human disease, 1,617 isolates from 327 individual product lots were genetically matched (using the flaA short variable region [SVR[) to 289 isolates from cases of human campylobacteriosis whose onset was within approximately 2 weeks from the date of processing. When there was genetic identity between broiler isolates and human isolates within the appropriate time frame, a retail product lot was classified as implicated in human disease. According to the results of this analysis, there were multiple clusters of human disease linked to the same process lot or lots. Implicated and nonimplicated retail product lots were compared for four lot descriptors: lot size, prevalence, mean contamination, and maximum contamination (as characterized by direct rinse plating). For retail product distributed fresh, Mann-Whitney U tests showed that implicated product lots had significantly (P = 0.0055) higher mean contamination than nonimplicated lots. The corresponding median values were 3.56 log CFU/carcass for implicated lots and 2.72 log CFU/carcass for nonimplicated lots. For frozen retail product, implicated lots were significantly (P = 0.0281) larger than nonimplicated lots. When the time frame was removed, retail product lots containing Campylobacter flaA SVR genotypes also seen in human disease had significantly higher mean and maximum contamination numbers than lots containing no genotypes seen in human disease for both fresh and frozen product. Our results suggest that cases of broiler-borne campylobacteriosis may occur in clusters and that the differences in mean contamination levels may provide a basis for regulatory action that is more specific than a presence-absence standard. PMID:18791017

50 CFR 22.22 - What are the requirements concerning permits for Indian religious purposes?

Code of Federal Regulations, 2012 CFR

2012-10-01

... information: (1) Species and number of eagles or feathers proposed to be taken, or acquired by gift or...) You must submit reports or inventories, including photographs, of eagle feathers or parts on hand as...

50 CFR 22.22 - What are the requirements concerning permits for Indian religious purposes?

Code of Federal Regulations, 2010 CFR

2010-10-01

... information: (1) Species and number of eagles or feathers proposed to be taken, or acquired by gift or...) You must submit reports or inventories, including photographs, of eagle feathers or parts on hand as...

50 CFR 22.22 - What are the requirements concerning permits for Indian religious purposes?

Code of Federal Regulations, 2013 CFR

2013-10-01

... information: (1) Species and number of eagles or feathers proposed to be taken, or acquired by gift or...) You must submit reports or inventories, including photographs, of eagle feathers or parts on hand as...

50 CFR 22.22 - What are the requirements concerning permits for Indian religious purposes?

Code of Federal Regulations, 2011 CFR

2011-10-01

... information: (1) Species and number of eagles or feathers proposed to be taken, or acquired by gift or...) You must submit reports or inventories, including photographs, of eagle feathers or parts on hand as...

50 CFR 22.22 - What are the requirements concerning permits for Indian religious purposes?

Code of Federal Regulations, 2014 CFR

2014-10-01

... information: (1) Species and number of eagles or feathers proposed to be taken, or acquired by gift or...) You must submit reports or inventories, including photographs, of eagle feathers or parts on hand as...

Solubility and diffusivity of nitrous oxide in ternary mixtures of water, monoethanolamine, and N-methyldiethanolamine and solution densities and viscosities

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hagewiesche, D.P.; Ashour, S.S.; Sandall, O.C.

1995-05-01

Recently, several researchers have suggested using aqueous mixtures of small amounts of monoethanolamine and much larger amounts of N-methyldiethanolamine for the absorption of CO{sub 2} and for the selective removal of H{sub 2}S from gas streams of mixtures of CO{sub 2} and H{sub 2}S. The densities and viscosities of aqueous N-methyldiethanolamine/monoethanolamine (MDEA/MEA) blends containing 30 and 40 mass % total amine with MEA concentrations of 5, 10, and 15 mass % of the total amine concentration were measured at temperatures of 303, 313, and 323 K. The diffusion coefficients and Henry`s law constants of N{sub 2}O in these solutions weremore » also measured and were used to estimate the diffusion coefficients and Henry`s law constants of CO{sub 2} in these solutions according to the N{sub 2}O/CO{sub 2} analogy technique.« less

Measurement of minority carrier diffusion lengths in GaAs nanowires by a nanoprobe technique

DOE Office of Scientific and Technical Information (OSTI.GOV)

Darbandi, A.; Watkins, S. P., E-mail: simonw@sfu.ca

Minority carrier diffusion lengths in both p-type and n-type GaAs nanowires were studied using electron beam induced current by means of a nanoprobe technique without lithographic processing. The diffusion lengths were determined for Au/GaAs rectifying junctions as well as axial p-n junctions. By incorporating a thin lattice-matched InGaP passivating shell, a 2-fold enhancement in the minority carrier diffusion lengths and one order of magnitude reduction in the surface recombination velocity were achieved.

7 CFR 46.20 - Lot numbers.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 2 2011-01-01 2011-01-01 false Lot numbers. 46.20 Section 46.20 Agriculture... Receivers § 46.20 Lot numbers. An identifying lot number shall be assigned to each shipment of produce to be sold on consignment or joint account or for the account of another person or firm. A lot number should...

7 CFR 46.20 - Lot numbers.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 7 Agriculture 2 2013-01-01 2013-01-01 false Lot numbers. 46.20 Section 46.20 Agriculture... Receivers § 46.20 Lot numbers. An identifying lot number shall be assigned to each shipment of produce to be sold on consignment or joint account or for the account of another person or firm. A lot number should...

7 CFR 46.20 - Lot numbers.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 2 2014-01-01 2014-01-01 false Lot numbers. 46.20 Section 46.20 Agriculture... Receivers § 46.20 Lot numbers. An identifying lot number shall be assigned to each shipment of produce to be sold on consignment or joint account or for the account of another person or firm. A lot number should...

7 CFR 46.20 - Lot numbers.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 7 Agriculture 2 2012-01-01 2012-01-01 false Lot numbers. 46.20 Section 46.20 Agriculture... Receivers § 46.20 Lot numbers. An identifying lot number shall be assigned to each shipment of produce to be sold on consignment or joint account or for the account of another person or firm. A lot number should...

7 CFR 46.20 - Lot numbers.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 2 2010-01-01 2010-01-01 false Lot numbers. 46.20 Section 46.20 Agriculture... Receivers § 46.20 Lot numbers. An identifying lot number shall be assigned to each shipment of produce to be sold on consignment or joint account or for the account of another person or firm. A lot number should...

Adaptation of micro-diffusion method for the analysis of (15) N natural abundance of ammonium in samples with small volume.

PubMed

Zhang, Shasha; Fang, Yunting; Xi, Dan

2015-07-30

There are several preparation methods for the measurement of the nitrogen (N) isotopic composition of ammonium (NH4 (+) ) in different types of samples (freshwater, saltwater and soil extracts). The diffusion method is the most popular and it involves NH4 (+) in solutions being released under alkaline conditions and then immediately trapped by an acidified filter. However, the traditional preparation is designed for samples with large volume and relatively high N concentrations. The performance of diffusion for small-volume samples (e.g., a few milliliters) remains unknown. We examined the overall performance of micro-diffusion on 5 mL samples on varying the incubation time, temperature and initial NH4 (+) concentration. The trapped ammonia was chemically converted into nitrous oxide (N2 O) with hypobromite and hydroxylamine in sequence. The produced N2 O was analyzed by a commercially available purge and cryogenic trap system coupled to an isotope ratio mass spectrometer. We found that diffusion can be complete with no more than 7 days of treatment at 37 °C. Increasing the temperature to 50 °C and the incubation time to 11 days did not improve the overall performance. There were no significant differences in the overall performance during diffusion with NH4 (+) concentrations from 15 to 60 μM. The blank size was relatively large, and the N contamination might come from the reagents especially KCl salts. The method presented here combines micro-diffusion and hypobromite oxidation and hydroxylamine reduction. It is suitable for samples with small volume and low NH4 (+) concentrations. Our study demonstrates that the NH4 (+) concentrations in samples can be as low as 15 μM, and a volume of 5 mL is sufficient for this method. We suggest that this method can be used for the routine determination of (15) N/(14) N for either natural abundance or (15) N-enriched NH4 (+) . Copyright © 2015 John Wiley & Sons, Ltd.

Homogeneity of GAFCHROMIC EBT2 film among different lot numbers

PubMed Central

Takahashi, Yutaka; Tanaka, Atsushi; Hirayama, Takamitsu; Yamaguchi, Tsuyoshi; Katou, Hiroaki; Takahara, Keiko; Okamoto, Yoshiaki; Teshima, Teruki

2012-01-01

EBT2 film is widely used for quality assurance in radiation therapy. The purpose of this study was to investigate the homogeneity of EBT2 film among various lots, and the dose dependence of heterogeneity. EBT2 film was positioned in the center of a flatbed scanner and scanned in transmission mode at 75 dpi. Homogeneity was investigated by evaluating gray value and net optical density (netOD) with the red color channel. The dose dependence of heterogeneity in a single sheet from five lots was investigated at 0.5, 2, and 3 Gy. Maximum coefficient of variation as evaluated by netOD in a single film was 3.0% in one lot, but no higher than 0.5% in other lots. Dose dependence of heterogeneity was observed on evaluation by gray value but not on evaluation by netOD. These results suggest that EBT2 should be examined in each lot number before clinical use, and that the dose calibration curve should be constructed using netOD. PACS number: 87 PMID:22766947

Perinatal complications in women with kidney transplant.

PubMed

Vázquez-Rodríguez, Juan G; Ríos-Chavarría, Ana L

2012-01-01

Pregnancy in patients with kidney grafts is considered high-risk. Determine perinatal complications in women with kidney transplants treated by our hospital and compare them with complications reported in national and international literature. We studied perinatal complications in 18 patients with renal transplantation who delivered 19 newborns and were treated between 1 January 2009 and 31 December 2010. Results were compared with previous reports. Maternal age: 28.27 ± 4.70 years old, parity: 2, interval from transplant to conception: 7.52 ± 6.20 years, first prenatal visit 14.35 ± 6.74 weeks, prenatal care: 18.88 ± 9.18 weeks, 6 prenatal visits, gestational age at birth: 33.11 ± 8.72 weeks. Maternal complications: cesarean section: 88.88%, blood transfusion: 38.88%, anaemia: 33.33%, premature rupture of membranes: 22.22%, preterm delivery: 22.22%, urinary tract infection: 16.66%, preeclampsia: 11.11%, uncontrolled hypertension: 11.11%, miscarriage: 11.11%, uterine antony: 5.55%, gestational diabetes: 0%, and mortality: 0%. Foetal complications: premature birth: 52.63%, mortality: 21.05%, intensive care: 21.05%, and low birth weight due to growth restriction: 10.52%. Transplantation complications: filtration impairment without need for dialysis: 5.55%, graft rejection: 0%, and graft loss: 0%. The frequency of perinatal complications was high. Pregnancy had no adverse effect on renal function and patient survival. Stable renal grafts in women of childbearing age is not necessarily a contraindication for pregnancy.

Experimental research on the effects of water application on greenhouse gas emissions from beef cattle feedlots

USDA-ARS?s Scientific Manuscript database

The effect of water application (e.g., through rainfall or sprinkler system) on emissions of greenhouse gases (GHGs), such as nitrous oxide (N2O), methane (CH4), and carbon dioxide (CO2), from pen surfaces of open-lot beef cattle feedlots was evaluated under controlled laboratory conditions. Soil/ma...

Workshop on Future Directions for Optical Information Processing.

DTIC Science & Technology

1981-03-01

h . The i reference point source simultaneously illuminates the i member of a family of n phase-encoding Aiffusers (e.g. shower glass , ground glass ...diffuser (ground glass ) section illuminated with a plane wave [35.37). The n(n-1) - 4(3) - 12 crosstalk terms have been distributed into the noise...for 2x2 input Fig. 6. Outnut of processor analogous to that array, l.Sx magnifier, ground glass diffuser of Fig. 5, but using spherical wavefront and

Effects of water-contaminated air on blowoff limits of opposed jet hydrogen-air diffusion flames

NASA Technical Reports Server (NTRS)

Pellett, Gerald L.; Jentzen, Marilyn E.; Wilson, Lloyd G.; Northam, G. Burton

1988-01-01

The effects of water-contaminated air on the extinction and flame restoration of the central portion of N2-diluted H2 versus air counterflow diffusion flames are investigated using a coaxial tubular opposed jet burner. The results show that the replacement of N2 contaminant in air by water on a mole for mole basis decreases the maximum sustainable H2 mass flow, just prior to extinction, of the flame. This result contrasts strongly with the analogous substitution of water for N2 in a relatively hot premixed H2-O2-N2 flame, which was shown by Koroll and Mulpuru (1986) to lead to a significant, kinetically controlled increase in laminar burning velocity.

Hydroxylamine diffusion can enhance N₂O emissions in nitrifying biofilms: a modeling study.

PubMed

Sabba, Fabrizio; Picioreanu, Cristian; Pérez, Julio; Nerenberg, Robert

2015-02-03

Wastewater treatment plants can be significant sources of nitrous oxide (N2O), a potent greenhouse gas. However, little is known about N2O emissions from biofilm processes. We adapted an existing suspended-growth mathematical model to explore N2O emissions from nitrifying biofilms. The model included N2O formation by ammonia-oxidizing bacteria (AOB) via the hydroxylamine and the nitrifier denitrification pathways. Our model suggested that N2O emissions from nitrifying biofilms could be significantly greater than from suspended growth systems under similar conditions. The main cause was the formation and diffusion of hydroxylamine, an AOB nitrification intermediate, from the aerobic to the anoxic regions of the biofilm. In the anoxic regions, hydroxylamine oxidation by AOB provided reducing equivalents used solely for nitrite reduction to N2O, since there was no competition with oxygen. For a continuous system, very high and very low dissolved oxygen (DO) concentrations resulted in lower emissions, while intermediate values led to higher emissions. Higher bulk ammonia concentrations and greater biofilm thicknesses increased emissions. The model effectively predicted N2O emissions from an actual pilot-scale granular sludge reactor for sidestream nitritation, but significantly underestimated the emissions when the NH2OH diffusion coefficient was assumed to be minimal. This numerical study suggests an unexpected and important role of hydroxylamine in N2O emission in biofilms.

Training Extract Historian AFSC: 791X2.

DTIC Science & Technology

1985-09-01

AW-RI61 I"N TRINING EXTRACT HISTORIAN AFSC: 9X2(U) RIR FORCE 1/2OCCUPATIONAL NERSURENENT CENTER RANDOLPH RFI TX SEP 05 UNCLASSIFIED F/O 519 ML ILhE...99919 :~~00 @04 0 00 mOto IIP-M’ ~ 1 1 F PIA@. .0 at0 Noost.4. NO~ -N C .ON.* 4 44 C C -Na d 0 *M -ON FM Ř ’a. fn . 10 00*0c f. - - - F 2 a. 0 �...CP.N INNN &. 4 . W! I.i. ID w~* At. *a -D x: T T. 6, +4 ao 11U a4 l.Ot I I O-AI61 IN TRAINING EXTRACT HISTORIAN AFSC: M9UM AIR FORCE 12I OCCUPATIONAL

77 FR 38849 - National Heart, Lung, and Blood Institute; Notice of Closed Meetings

Federal Register 2010, 2011, 2012, 2013, 2014

2012-06-29

... DEPARTMENT OF HEALTH AND HUMAN SERVICES National Institutes of Health National Heart, Lung, and... constitute a clearly unwarranted invasion of personal privacy. Name of Committee: National Heart, Lung, and... Heart, Lung, and Blood Institute, 6701 Rockledge Drive, Room 7190, Bethesda, MD 20892-7924, 301-435-2222...

Yellow Sea Mine Hunting Using the Navy’s CASS/GRAB Model

DTIC Science & Technology

2001-05-01

f15fe eeapoiaey5 ad o h otso 04 t.Y .a. L ion leo 210. 210 £igure 14. Februarv GDEM 4 hr a. Rock Botton at 37.5 N 123.0 E and a Source Depth= 25 .a...SinlLcsscnor 2zs47 * .... ... lt- . . .... ° 1 . ,, . ....... . . ........ lot ýto0 a. Figre2I FbruryGDM ~r G’ae•Botoma•.•..N 230Eand a Source Dpt 2-5 ft. a...1m • GDEM for a G ave4 B0to a 38 0.350Nt;J0 n So7 re Det,0 125ft a.RyTae0n3?Sga Ecs odm M30 aw -, .3 m- a n.03 3.b. 0.00~~~~ co?50.007 S• •r, • • •, • l

Temporal nitrous oxide emissions from beef cattle feedlot manure following a simulated rainfall event

USDA-ARS?s Scientific Manuscript database

A pilot-scale, recirculating-flow-through, non-steady-state (RFT-NSS) chamber system was designed for quantifying nitrous oxide (N2O) emissions from simulated open-lot beef cattle feedlot pens. The system employed five 1 square meter steel pans. A lid was placed systematically on each pan and heads...

Side chain variations radically alter the diffusion of poly(2-alkyl-2-oxazoline) functionalised nanoparticles through a mucosal barrier.

PubMed

Mansfield, Edward D H; de la Rosa, Victor R; Kowalczyk, Radoslaw M; Grillo, Isabelle; Hoogenboom, Richard; Sillence, Katy; Hole, Patrick; Williams, Adrian C; Khutoryanskiy, Vitaliy V

2016-08-16

Functionalised nanomaterials are gaining popularity for use as drug delivery vehicles and, in particular, mucus penetrating nanoparticles may improve drug bioavailability via the oral route. To date, few polymers have been investigated for their muco-penetration, and the effects of systematic structural changes to polymer architectures on the penetration and diffusion of functionalised nanomaterials through mucosal tissue have not been reported. We investigated the influence of poly(2-oxazoline) alkyl side chain length on nanoparticle diffusion; poly(2-methyl-2-oxazoline), poly(2-ethyl-2-oxazoline), and poly(2-n-propyl-2-oxazoline) were grafted onto the surface of thiolated silica nanoparticles and characterised by FT-IR, Raman and NMR spectroscopy, thermogravimetric analysis, and small angle neutron scattering. Diffusion coefficients were determined in water and in a mucin dispersion (using Nanoparticle Tracking Analysis), and penetration through a mucosal barrier was assessed using an ex vivo fluorescence technique. The addition of a single methylene group in the side chain significantly altered the penetration and diffusion of the materials in both mucin dispersions and mucosal tissue. Nanoparticles functionalised with poly(2-methyl-2-oxazoline) were significantly more diffusive than particles with poly(2-ethyl-2-oxazoline) while particles with poly(2-n-propyl-2-oxazoline) showed no significant increase compared to the unfunctionalised particles. These data show that variations in the polymer structure can radically alter their diffusive properties with clear implications for the future design of mucus penetrating systems.

Polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) in harbor sediments from Sea Lots, Port-of-Spain, Trinidad and Tobago

USGS Publications Warehouse

Mohammed, Azad; Peterman, Paul; Echols, Kathy; Feltz, Kevin; Tegerdine, George; Manoo, Anton; Maraj, Dexter; Agard, John; Orazio, Carl

2011-01-01

Concentrations of polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) were determined in nearshore marine surficial sediments from three locations in Trinidad. Sediments were sampled at Sea Lots on the west coast, in south Port-of-Spain Harbor, south of Sea Lots at Caroni Lagoon National Park, and on Trinidad's east coast at Manzanilla. Total PCB concentrations in Sea Lots sediments ranged from 62 to 601 ng/g (dry weight {dw}), which was higher than at Caroni and Manzanilla, 13 and 8 ng/g dw, respectively. Total OCP concentrations at Sea Lots were ranged from 44.5 to 145 ng/g dw, compared with 13.1 and 23.8 n/g (dw), for Caroni and Manzanilla respectively. The concentrations of PCBs and of some OCPs in sediments from Sea Lots were above the Canadian interim sediment quality guidelines. To date, this data is the first report on the levels of PCBs and other organochlorine compounds from Trinidad and Tobago.

FLUORIDE CONCENTRATIONS IN INDUSTRIALIZED BEVERAGES CONSUMED BY CHILDREN IN THE CITY OF BAURU, BRAZIL

PubMed Central

Lodi, Carolina Simonetti; Ramires, Irene; Pessan, Juliano Pelim; Neves, Lucimara Teixeira das; Buzalaf, Marília Afonso Rabelo

2007-01-01

The increasing consumption of juices, soft drinks and teas among children has increased significantly fluoride ingestion at the age range of risk for development of dental fluorosis. Objective: The purpose of this study was to evaluate fluoride concentrations in some brands of industrialized beverages consumed by children in the city of Bauru, SP, Brazil. Material and Methods: 98 brands of beverages were analyzed, divided into 3 lots, comprising 36, 32 and 30 brands, respectively, for the first, second and third lots. Fluoride concentrations were determined by HMDS-facilitated diffusion, using a fluoride ion-specific electrode (Orion 9409). Results: Fluoride concentrations ranged between 0.04 and 1.76 μg F/mL. It was observed a wide variation in fluoride concentrations among the different brands, as well as the different lots of the same brand. There was no information on fluoride concentrations on the labels of any product. Conclusions: Some of the products analyzed could contribute significantly to the total fluoride intake and, thus, be important risk factors for development of dental fluorosis, which indicates the need of controlling the production of these beverages with respect to fluoride concentration. PMID:19089131

[Coverage rate and satisfaction of populations after mass treatment with praziquantel and albendazole in Mali].

PubMed

Sangho, H; Dabo, A; Sidibé, A; Dembélé, R; Diawara, A; Diallo, A; Konaté, S

2009-01-01

In Mali, schistosomiasis always remains a major public health problem. In 2005, mass treatment campaigns with praziquantel and albendazole have been organized in all endemic regions. The present study aimed to assess the impact of these mass treatment campaigns and the recipient's satisfaction in two endemic areas (Mopti and Ségou). It was a cross-sectional study with one passage from February to March 2006. The study carried out on political authorities (n=142), teachers and school administers (n=70), health workers (n=46), community distributors (n=33), community members (n=2170) and pupils (n=2480). We used Lot Quality Assurance Sample (LQAS) to determine treatment coverage and recipient's satisfaction. Two types of lots were considered, villages and schools. Questionnaires were used for investigation. In Ségou, the treatment rates varied from 100% at school level and in community in Bla district to 97.2% in the community of Ségou town. In Mopti, a treatment rate of 100% was observed in Bankass and Douentza both at school and in the community. The proportion of happiest individuals (to feel well) after the mass treatment campaign was 72.3% among pupils and 76.6% in the community. The results of this study suggest that the high treatment coverage rates observed during these campaigns should be sustained by a yearly chemotherapy strategy preceded by a community's health education programmes.

Single-Nanoparticle Photoelectrochemistry at a Nanoparticulate TiO2 -Filmed Ultramicroelectrode.

PubMed

Peng, Yue-Yi; Ma, Hui; Ma, Wei; Long, Yi-Tao; Tian, He

2018-03-26

An ultrasensitive photoelectrochemical method for achieving real-time detection of single nanoparticle collision events is presented. Using a micrometer-thick nanoparticulate TiO 2 -filmed Au ultra-microelectrode (TiO 2 @Au UME), a sub-millisecond photocurrent transient was observed for an individual N719-tagged TiO 2 (N719@TiO 2 ) nanoparticle and is due to the instantaneous collision process. Owing to a trap-limited electron diffusion process as the rate-limiting step, a random three-dimensional diffusion model was developed to simulate electron transport dynamics in TiO 2 film. The combination of theoretical simulation and high-resolution photocurrent measurement allow electron-transfer information of a single N719@TiO 2 nanoparticle to be quantified at single-molecule accuracy and the electron diffusivity and the electron-collection efficiency of TiO 2 @Au UME to be estimated. This method provides a test for studies of photoinduced electron transfer at the single-nanoparticle level. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

How thin barrier metal can be used to prevent Co diffusion in the modern integrated circuits?

NASA Astrophysics Data System (ADS)

Dixit, Hemant; Konar, Aniruddha; Pandey, Rajan; Ethirajan, Tamilmani

2017-11-01

In modern integrated circuits (ICs), billions of transistors are connected to each other via thin metal layers (e.g. copper, cobalt, etc) known as interconnects. At elevated process temperatures, inter-diffusion of atomic species can occur among these metal layers, causing sub-optimal performance of interconnects, which may lead to the failure of an IC. Thus, typically a thin barrier metal layer is used to prevent the inter-diffusion of atomic species within interconnects. For ICs with sub-10 nm transistors (10 nm technology node), the design rule (thickness scaling) demands the thinnest possible barrier layer. Therefore, here we investigate the critical thickness of a titanium-nitride (TiN) barrier that can prevent the cobalt diffusion using multi-scale modeling and simulations. First, we compute the Co diffusion barrier in crystalline and amorphous TiN with the nudged elastic band method within first-principles density functional theory simulations. Later, using the calculated activation energy barriers, we quantify the Co diffusion length in the TiN metal layer with the help of kinetic Monte Carlo simulations. Such a multi-scale modelling approach yields an exact critical thickness of the metal layer sufficient to prevent the Co diffusion in IC interconnects. We obtain a diffusion length of a maximum of 2 nm for a typical process of thermal annealing at 400 °C for 30 min. Our study thus provides useful physical insights for the Co diffusion in the TiN layer and further quantifies the critical thickness (~2 nm) to which the metal barrier layer can be thinned down for sub-10 nm ICs.

Analysis of Al diffusion processes in TiN barrier layers for the application in silicon solar cell metallization

NASA Astrophysics Data System (ADS)

Kumm, J.; Samadi, H.; Chacko, R. V.; Hartmann, P.; Wolf, A.

2016-07-01

An evaporated Al layer is known as an excellent rear metallization for highly efficient solar cells, but suffers from incompatibility with a common solder process. To enable solar cell-interconnection and module integration, in this work the Al layer is complemented with a solder stack of TiN/Ti/Ag or TiN/NiV/Ag, in which the TiN layer acts as an Al diffusion barrier. X-ray photoelectron spectroscopy measurements prove that diffusion of Al through the stack and the formation of an Al2O3 layer on the stack's surface are responsible for a loss of solderability after a strong post-metallization anneal, which is often mandatory to improve contact resistance and passivation quality. An optimization of the reactive TiN sputter process results in a densification of the TiN layer, which improves its barrier quality against Al diffusion. However, measurements with X-ray diffraction and scanning electron microscopy show that small grains with vertical grain boundaries persist, which still offer fast diffusion paths. Therefore, the concept of stuffing is introduced. By incorporating oxygen into the grain boundaries of the sputtered TiN layer, Al diffusion is strongly reduced as confirmed by secondary ion mass spectroscopy profiles. A quantitative analysis reveals a one order of magnitude lower Al diffusion coefficient for stuffed TiN layers. This metallization system maintains its solderability even after strong post-metallization annealing at 425 °C for 15 min. This paper thus presents an industrially feasible, conventionally solderable, and long-term stable metallization scheme for highly efficient silicon solar cells.

Effect of diffusive and nondiffusive surfaces combinations on sound diffusion

NASA Astrophysics Data System (ADS)

Shafieian, Masoume; Kashani, Farokh Hodjat

2010-05-01

One of room acoustic goals, especially in small to medium rooms, is sound diffusion in low frequencies, which have been the subject of lots of researches. Sound diffusion is a very important consideration in acoustics because it minimizes the coherent reflections that cause problems. It also tends to make an enclosed space sound larger than it is. Diffusion is an excellent alternative or complement to sound absorption in acoustic treatment because it doesn’t really remove much energy, which means it can be used to effectively reduce reflections while still leaving an ambient or live sounding space. Distribution of diffusive and nondiffusive surfaces on room walls affect sound diffusion in room, but the amount, combination, and location of these surfaces are still the matter of question. This paper investigates effects of these issues on room acoustic frequency response in different parts of the room with different source-receiver locations. Room acoustic model based on wave method is used (implemented) which is very accurate and convenient for low frequencies in such rooms. Different distributions of acoustic surfaces on room walls have been introduced to the model and room frequency response results are calculated. For the purpose of comparison, some measurements results are presented. Finally for more smooth frequency response in small and medium rooms, some suggestions are made.

Comparison of diffuse CO2 degassing at Miravalles and Rincón de la Vieja volcanoes (Guanacaste Province, Costa Rica)

NASA Astrophysics Data System (ADS)

Liegler, A.; Bakkar Hindeleh, H.; Deering, C. D.; Fentress, S. E.

2015-12-01

Volcanic gas emissions are a key component for monitoring volcanic activity, magmatic input of volatiles to the atmosphere and the assessment of geothermal potential in volcanic regions. Diffuse soil degassing has been shown to represent a major part of volcanic gas emissions. However, this type of gas emission has not yet been quantified in the Guanacaste province of Costa Rica; a region of the country with several large, active or dormant volcanoes. We conducted the first study of diffuse CO2 degassing at Rincón de la Vieja and Miravalles volcanoes, both located in Guanacaste. Diffuse degassing was measured using the accumulation chamber method to quantify CO2 flux in regions where hydrothermal surface features indicate anomalous activity. The total diffuse carbon dioxide flux estimated at Miravalles in two areas, together roughly 2 km2 in size, was 135 t/day and in several areas at Rincón de la Vieja a minimum of 4 t/day. Comparatively low flux values and a very local concentration (few m2) of CO2 flux were observed at the active Rincón de la Vieja volcano, compared to the dormant Miravalles volcano, where significant soil flux was found over extended areas, not only around vents. Our assessment of the origin of these differences leads to two possibilities depending on if the surface features on the two volcanoes are fed by a common hydrothermal system or two separate ones. In the former case, the different intensity of diffuse CO2 flux could indicate a different degassing behavior and stronger concentration of gas emissions at the active vent areas at Rincon de la Vieja. In the latter case, where the hydrothermal systems are not linked, the amount of CO2 degassed through the flanks of the volcanoes could indicate that different physical and chemical conditions are governing the degassing of the two systems.

Redox-stratification controlled biofilm (ReSCoBi) for completely autotrophic nitrogen removal: the effect of co- versus counter-diffusion on reactor performance.

PubMed

Terada, Akihiko; Lackner, Susanne; Tsuneda, Satoshi; Smets, Barth F

2007-05-01

A multi-population biofilm model for completely autotrophic nitrogen removal was developed and implemented in the simulation program AQUASIM to corroborate the concept of a redox-stratification controlled biofilm (ReSCoBi). The model considers both counter- and co-diffusion biofilm geometries. In the counter-diffusion biofilm, oxygen is supplied through a gas-permeable membrane that supports the biofilm while ammonia (NH(4)(+)) is supplied from the bulk liquid. On the contrary, in the co-diffusion biofilm, both oxygen and NH(4)(+) are supplied from the bulk liquid. Results of the model revealed a clear stratification of microbial activities in both of the biofilms, the resulting chemical profiles, and the obvious effect of the relative surface loadings of oxygen and NH(4)(+) (J(O(2))/J(NH(4)(+))) on the reactor performances. Steady-state biofilm thickness had a significant but different effect on T-N removal for co- and counter-diffusion biofilms: the removal efficiency in the counter-diffusion biofilm geometry was superior to that in the co-diffusion counterpart, within the range of 450-1,400 microm; however, the efficiency deteriorated with a further increase in biofilm thickness, probably because of diffusion limitation of NH(4)(+). Under conditions of oxygen excess (J(O(2))/J(NH(4)(+)) > 3.98), almost all NH(4)(+) was consumed by aerobic ammonia oxidation in the co-diffusion biofilm, leading to poor performance, while in the counter-diffusion biofilm, T-N removal efficiency was maintained because of the physical location of anaerobic ammonium oxidizers near the bulk liquid. These results clearly reveal that counter-diffusion biofilms have a wider application range for autotrophic T-N removal than co-diffusion biofilms. (c) 2006 Wiley Periodicals, Inc.

40 CFR 52.128 - Rule for unpaved parking lots, unpaved roads and vacant lots.

Code of Federal Regulations, 2014 CFR

2014-07-01

.... Research Triangle Park, N.C. May 1982. 3. “Method 9—Visible Determination of the Opacity of Emissions from... other dust generating operations which have been terminated for over eight months. (3) The test methods... than or equal to a nominal 10 micrometers as measured by reference or equivalent methods that meet the...

40 CFR 52.128 - Rule for unpaved parking lots, unpaved roads and vacant lots.

Code of Federal Regulations, 2012 CFR

2012-07-01

.... Research Triangle Park, N.C. May 1982. 3. “Method 9—Visible Determination of the Opacity of Emissions from... other dust generating operations which have been terminated for over eight months. (3) The test methods... than or equal to a nominal 10 micrometers as measured by reference or equivalent methods that meet the...

40 CFR 52.128 - Rule for unpaved parking lots, unpaved roads and vacant lots.

Code of Federal Regulations, 2013 CFR

2013-07-01

.... Research Triangle Park, N.C. May 1982. 3. “Method 9—Visible Determination of the Opacity of Emissions from... other dust generating operations which have been terminated for over eight months. (3) The test methods... than or equal to a nominal 10 micrometers as measured by reference or equivalent methods that meet the...

Duration of fever and other symptoms after the inhalation of laninamivir octanoate hydrate for influenza treatment; comparison among the four Japanese influenza seasons from 2011-2012 to 2014-2015.

PubMed

Ikematsu, Hideyuki; Kawai, Naoki; Iwaki, Norio; Kashiwagi, Seizaburo

2016-09-01

The duration of fever and other symptoms as markers of the clinical effectiveness of laninamivir octanoate hydrate (laninamivir) were investigated in the Japanese 2014-2015 influenza season and the results were compared with those of the previous three seasons, 2011-2012 to 2013-2014. From these four seasons, the data of 636 influenza A(H3N2) and 128 influenza B patients was available for analysis. No significant difference was found in their baseline characteristics. The median duration of fever for all A(H3N2) patients ranged from 32.0 to 41.0 h. The duration of fever in the 2014-2015 season was significantly shorter than that in the 2012-2013 and 2013-2014 seasons (p = 0.0204 and 0.0391, respectively), but the differences were within nine hours. The median duration of symptoms for A(H3N2) ranged from 80.0 to 89.0 h, with no significant difference among the four seasons (p = 0.2222). The median duration of fever for B patients ranged from 43.0 to 50.0 h, with no significant difference among the four seasons. The duration of the symptoms for B varied by season, but no significant difference was found among the four seasons. Over the four seasons, 44 adverse events were reported from among 921 patients, with all resolving without treatment. These results indicate the continuing effectiveness of laninamivir against influenza A(H3N2) and B, with no safety issues. It is unlikely that the clinical use of laninamivir has caused viral resistance in the currently epidemic viruses. Copyright © 2016 Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

The genus Milnesium (Eutardigrada: Milnesiidae) in the Sierra Nevada de Santa Marta (Colombia), with the description of Milnesium kogui sp. nov.

PubMed

Londoño, Rosana; Daza, Anisbeth; Caicedo, Martín; Quiroga, Sigmer; Kaczmarek, Łukasz

2015-05-06

A new species, Milnesium kogui sp. nov. is described from the Sierra Nevada de Santa Marta, Colombia. The new species belongs to the tardigradum group and is most similar, by the claw configuration [2-2]-[2-2], to Milnesium dujiangensis and Milnesium katarzynae. Milnesium kogui sp. nov. differs from M. dujiangensis mainly by the presence of primary branches on all legs and from M. katarzynae by the absence of dorsal sculpture. Additionally, in this paper we present a list of all Milnesium species recorded in Colombia including Milnesium cf. barbadosense Meyer & Hinton, 2012 and M. brachyungue Binda & Pilato, 1990, new additions to the recorded fauna of Colombia.

Click- and chirp-evoked human compound action potentials

PubMed Central

Chertoff, Mark; Lichtenhan, Jeffery; Willis, Marie

2010-01-01

In the experiments reported here, the amplitude and the latency of human compound action potentials (CAPs) evoked from a chirp stimulus are compared to those evoked from a traditional click stimulus. The chirp stimulus was created with a frequency sweep to compensate for basilar membrane traveling wave delay using the O-Chirp equations from Fobel and Dau [(2004). J. Acoust. Soc. Am. 116, 2213–2222] derived from otoacoustic emission data. Human cochlear traveling wave delay estimates were obtained from derived compound band action potentials provided by Eggermont [(1979). J. Acoust. Soc. Am. 65, 463–470]. CAPs were recorded from an electrode placed on the tympanic membrane (TM), and the acoustic signals were monitored with a probe tube microphone attached to the TM electrode. Results showed that the amplitude and latency of chirp-evoked N1 of the CAP differed from click-evoked CAPs in several regards. For the chirp-evoked CAP, the N1 amplitude was significantly larger than the click-evoked N1s. The latency-intensity function was significantly shallower for chirp-evoked CAPs as compared to click-evoked CAPs. This suggests that auditory nerve fibers respond with more unison to a chirp stimulus than to a click stimulus. PMID:21117748

Clustered lot quality assurance sampling to assess immunisation coverage: increasing rapidity and maintaining precision.

PubMed

Pezzoli, Lorenzo; Andrews, Nick; Ronveaux, Olivier

2010-05-01

Vaccination programmes targeting disease elimination aim to achieve very high coverage levels (e.g. 95%). We calculated the precision of different clustered lot quality assurance sampling (LQAS) designs in computer-simulated surveys to provide local health officers in the field with preset LQAS plans to simply and rapidly assess programmes with high coverage targets. We calculated sample size (N), decision value (d) and misclassification errors (alpha and beta) of several LQAS plans by running 10 000 simulations. We kept the upper coverage threshold (UT) at 90% or 95% and decreased the lower threshold (LT) progressively by 5%. We measured the proportion of simulations with < or =d individuals unvaccinated or lower if the coverage was set at the UT (pUT) to calculate beta (1-pUT) and the proportion of simulations with >d unvaccinated individuals if the coverage was LT% (pLT) to calculate alpha (1-pLT). We divided N in clusters (between 5 and 10) and recalculated the errors hypothesising that the coverage would vary in the clusters according to a binomial distribution with preset standard deviations of 0.05 and 0.1 from the mean lot coverage. We selected the plans fulfilling these criteria: alpha < or = 5% beta < or = 20% in the unclustered design; alpha < or = 10% beta < or = 25% when the lots were divided in five clusters. When the interval between UT and LT was larger than 10% (e.g. 15%), we were able to select precise LQAS plans dividing the lot in five clusters with N = 50 (5 x 10) and d = 4 to evaluate programmes with 95% coverage target and d = 7 to evaluate programmes with 90% target. These plans will considerably increase the feasibility and the rapidity of conducting the LQAS in the field.

Safety and immunogenicity of a trivalent, inactivated, mammalian cell culture-derived influenza vaccine in healthy adults, seniors, and children.

PubMed

Halperin, Scott A; Smith, Bruce; Mabrouk, Taoufik; Germain, Marc; Trépanier, Pierre; Hassell, Thomas; Treanor, John; Gauthier, Richard; Mills, Elaine L

2002-01-15

We performed randomized, double-blind, controlled trials to assess the safety and immunogenicity of an inactivated, Madin Darby Canine Kidney (MDCK)-derived cell line produced influenza vaccine in healthy adults (19-50 years), children (3-12 years) and the elderly (> or =65 years). We studied three lots of cell culture-derived vaccine and one lot of licensed egg-derived vaccine in healthy adults (n=462), two lots of cell culture-derived vaccine and one lot of egg-derived vaccine in seniors (n=269), and one lot of each vaccine in children (n=209). Adverse events were collected during the first 3 days post-immunization; serum was collected before and 1 month after immunization. Rates of local and systemic adverse reactions were similar with both vaccines. An injection site adverse event rated at least moderate severity was reported by 21.9% of children who received the egg-derived vaccine and 25.0% of those who received the cell culture-derived vaccine. In healthy adults the proportions were 12.1 and 15.3%, respectively and 6.7 and 6.3%, respectively in seniors. Systemic events of at least moderate severity were 12.4 and 12.5% in children, 19.8 and 13.6% in healthy adults, and 14.1 and 9.7% in seniors; none of these differences were statistically significant. The antibody response against all three viruses was similar between the two vaccines. From 83 to 100% of children, healthy adults and seniors achieved hemagglutination inhibition titers in excess of 40 post-immunization. We conclude that the cell culture-derived vaccine was safe and immunogenic in children, healthy adults and seniors.

Immunogenicity and safety of an investigational multicomponent, recombinant, meningococcal serogroup B vaccine (4CMenB) administered concomitantly with routine infant and child vaccinations: results of two randomised trials.

PubMed

Vesikari, Timo; Esposito, Susanna; Prymula, Roman; Ypma, Ellen; Kohl, Igor; Toneatto, Daniela; Dull, Peter; Kimura, Alan

2013-03-09

Meningococcal serogroup B disease disproportionately affects infants. We assessed lot-to-lot consistency, safety and immunogenicity, and the effect of concomitant vaccination on responses to routine vaccines of an investigational multicomponent vaccine (4CMenB) in this population. We did primary and booster phase 3 studies between March 31, 2008, and Aug 16, 2010, in 70 sites in Europe. We used two series of sponsor-supplied, computer-generated randomisation envelopes to allocate healthy 2 month-old infants to receive routine vaccinations (diphtheria-tetanus-acellular pertussis, inactivated poliovirus, hepatitis B plus Haemophilus influenzae type b, and seven-valent pneumococcal vaccine) at 2, 4, and 6 months of age alone, or concomitantly with 4CMenB or serogroup C conjugate vaccine (MenC) in: 1) an open-label, lot-to-lot immunogenicity and safety substudy of three 4CMenB lots compared with routine vaccines alone (1:1:1:1, block size eight); or 2) an observer-blind, lot-to-lot safety substudy of three 4CMenB lots compared with MenC (1:1:1:3, block size six). At 12 months, 4CMenB-primed children from either substudy were randomised (1:1, block size two) to receive 4CMenB booster, with or without measles-mumps-rubella-varicella (MMRV) vaccine. Immunogenicity was assessed by serum bactericidal assay with human complement (hSBA) against serogroup B test strains, and on randomly selected subsets of serum samples for routine vaccines; laboratory personnel were masked to assignment. The first coprimary outcome was lot-to-lot consistency (hSBA geometric mean ratio of all lots between 0·5 and 2·0), and the second was an immune response (hSBA titre ≥5) for each of the three strains. The primary outcome for the booster study was immune response to booster dose. Immunogenicity data for 4CMenB were for the modified intention-to-treat population, including all infants from the open-label substudy who provided serum samples. The safety population included all participants who contributed safety data after at least one dose of study vaccine. These trials are registered with ClinicalTrials.gov, numbers NCT00657709 and NCT00847145. We enrolled 2627 infants in the open-label phase, 1003 in the observer-blind phase, and 1555 in the booster study. Lot-to-lot consistency was shown for the three 4CMenB lots, with the lowest 95% lower confidence limit being 0·74 and the highest upper limit being 1·33. Of 1181–1184 infants tested 1 month after three 4CMenB doses (all lots pooled), 100% (95% CI 99–100) had hSBA titres of 5 or more against strains selective for factor H binding protein and neisserial adhesin A, and 84% (82–86) for New Zealand outer-membrane vesicle. In a subset (n=100), 84% (75–91) of infants had hSBA titres of 5 or more against neisseria heparin binding antigen. At 12 months of age, waning titres were boosted by a fourth dose, such that 95–100% of children had hSBA titres of 5 or more for all antigens, with or without concomitant MMRV. Immune responses to routine vaccines were much the same with or without concomitant 4CMenB, but concomitant vaccination was associated with increased reactogenicity. 77% (1912 of 2478) of infants had fever of 38·5°C or higher after any 4CMenB dose, compared with 45% (295 of 659) after routine vaccines alone and 47% (228 of 490) with MenC, but only two febrile seizures were deemed probably related to 4CMenB. 4CMenB is immunogenic in infants and children aged 12 months with no clinically relevant interference with routine vaccines, but increases reactogenicity when administered concomitantly with routine vaccines. This breakthrough vaccine offers an innovative solution to the major remaining cause of bacterial meningitis in infant and toddlers. Novartis Vaccines and Diagnostics.

Using Global Invariant Manifolds to Understand Metastability in the Burgers Equation With Small Viscosity

NASA Astrophysics Data System (ADS)

Beck, Margaret; Wayne, C. Eugene

2009-01-01

The large-time behavior of solutions to the Burgers equation with small viscosity is described using invariant manifolds. In particular, a geometric explanation is provided for a phenomenon known as metastability, which in the present context means that solutions spend a very long time near the family of solutions known as diffusive N-waves before finally converging to a stable self-similar diffusion wave. More precisely, it is shown that in terms of similarity, or scaling, variables in an algebraically weighted L^2 space, the self-similar diffusion waves correspond to a one-dimensional global center manifold of stationary solutions. Through each of these fixed points there exists a one-dimensional, global, attractive, invariant manifold corresponding to the diffusive N-waves. Thus, metastability corresponds to a fast transient in which solutions approach this metastable manifold of diffusive N-waves, followed by a slow decay along this manifold, and, finally, convergence to the self-similar diffusion wave.

Effect of Grain Size on Differential Desorption of Volatile Species and on Non-ideal MHD Diffusivity

NASA Astrophysics Data System (ADS)

Zhao, Bo; Caselli, Paola; Li, Zhi-Yun

2018-05-01

We developed a chemical network for modeling the chemistry and non-ideal MHD effects from the collapsing dense molecular clouds to protostellar disks. First, we re-formulated the cosmic-ray desorption rate by considering the variations of desorption rate over the grain size distribution. We find that the differential desorption of volatile species is amplified by the grains larger than 0.1 μm, because larger grains are heated to a lower temperature by cosmic-rays and hence more sensitive to the variations in binding energies. As a result, atomic nitrogen N is ˜2 orders of magnitude more abundant than CO; N2H+ also becomes a few times more abundant than HCO+ due to the increased gas-phase N2. However, the changes in ionization fraction due to freeze-out and desorption only have minor effects on the non-ideal MHD diffusivities. Our chemical network confirms that the very small grains (VSGs: below a few 100 Å) weakens the efficiency of both ambipolar diffusion and Hall effect. In collapsing dense cores, a maximum ambipolar diffusion is achieved when truncating the MRN size distribution at 0.1 μm, and for a maximum Hall effect, the truncation occurs at 0.04 μm. We conclude that the grain size distribution is crucial to the differential depletion between CO and N2 related molecules, as well as to the non-ideal MHD diffusivities in dense cores.

Intradermally-administered influenza virus vaccine is safe and immunogenic in healthy adults 18-64 years of age.

PubMed

Gorse, Geoffrey J; Falsey, Ann R; Fling, John A; Poling, Terry L; Strout, Cynthia B; Tsang, Peter H

2013-05-01

To increase vaccine acceptance, intradermal (ID) influenza vaccine (Fluzone(®) Intradermal, Sanofi Pasteur Inc.) may be an attractive alternative to intramuscular (IM) vaccination due to smaller needle and volume injected. A multicenter, randomized (2:1 ID vs IM vaccines) study, blinded for ID vaccine lots, was conducted among 4292 adults 18-64 years of age enrolled in October 2008. Three lots of investigational trivalent influenza vaccine containing 9μg hemagglutinin (HA) per strain in 0.1mL administered ID with a 30 gauge, 1.5mm long needle were compared to standard dose vaccine (0.5mL containing 15μg HA/strain) given IM. The post-vaccination antibody geometric mean titers (GMT) for the ID vaccine were similar to the IM vaccine (H1N1: 193.2 vs. 178.3, H3N2: 246.7 vs. 230.7, and B: 102.5 vs. 126.9). Non-inferiority was met for the ID vaccine compared to IM vaccine as assessed by antibody GMT ratios (IM/ID) for all three virus strains (H1N1: 0.92, H3N2: 0.94, and B: 1.24). Seroconversion rates were non-inferior for H1N1 and H3N2, but not for B (ID vs. IM: H1N1: 61.2% vs. 60.5%, H3N2: 75.3% vs. 74.8%, and B: 46.2% vs. 54.2%). Seroprotection (HAI titer ≥1:40) rates were similar between groups (ID vs. IM, H1N1: 91.1% vs. 91.7%, H3N2: 90.7% vs. 91.4%, and B: 87.4% vs. 89.3%). Local injection site reactions overall were more common with ID than IM vaccine (ID vs. IM: 89.2% vs. 60.2%), but were usually grade 1 or 2 and transient. The frequencies of local injection site pain and systemic reactions were similar between vaccine groups, except more myalgia with IM vaccine. The ID vaccine elicited immune responses comparable to IM vaccine except for the seroconversion rate to B virus. With the exception of pain, local injection site reactions were more common with the ID vaccine, but well-tolerated and of short duration. ClinicalTrials.gov identifier: NCT00772109. Copyright © 2013 Elsevier Ltd. All rights reserved.

Transport coefficients in high-temperature ionized air flows with electronic excitation

NASA Astrophysics Data System (ADS)

Istomin, V. A.; Oblapenko, G. P.

2018-01-01

Transport coefficients are studied in high-temperature ionized air mixtures using the modified Chapman-Enskog method. The 11-component mixture N2/N2+/N /N+/O2/O2+/O /O+/N O /N O+/e- , taking into account the rotational and vibrational degrees of freedom of molecules and electronic degrees of freedom of both atomic and molecular species, is considered. Using the PAINeT software package, developed by the authors of the paper, in wide temperature range calculations of the thermal conductivity, thermal diffusion, diffusion, and shear viscosity coefficients for an equilibrium ionized air mixture and non-equilibrium flow conditions for mixture compositions, characteristic of those in shock tube experiments and re-entry conditions, are performed. For the equilibrium air case, the computed transport coefficients are compared to those obtained using simplified kinetic theory algorithms. It is shown that neglecting electronic excitation leads to a significant underestimation of the thermal conductivity coefficient at temperatures higher than 25 000 K. For non-equilibrium test cases, it is shown that the thermal diffusion coefficients of neutral species and the self-diffusion coefficients of all species are strongly affected by the mixture composition, while the thermal conductivity coefficient is most strongly influenced by the degree of ionization of the flow. Neglecting electronic excitation causes noticeable underestimation of the thermal conductivity coefficient at temperatures higher than 20 000 K.

Utility of Phox2b immunohistochemical stain in neural crest tumours and non-neural crest tumours in paediatric patients.

PubMed

Warren, Mikako; Matsuno, Ryosuke; Tran, Henry; Shimada, Hiroyuki

2018-03-01

This study evaluated the utility of Phox2b in paediatric tumours. Previously, tyrosine hydroxylase (TH) was the most widely utilised sympathoadrenal marker specific for neural crest tumours with neuronal/neuroendocrine differentiation. However, its sensitivity is insufficient. Recently Phox2b has emerged as another specific marker for this entity. Phox2b immunohistochemistry (IHC) was performed on 159 paediatric tumours, including (group 1) 65 neural crest tumours with neuronal differentiation [peripheral neuroblastic tumours (pNT)]: 15 neuroblastoma undifferentiated (NB-UD), 10 NB poorly differentiated (NB-PD), 10 NB differentiating (NB-D), 10 ganglioneuroblastoma intermixed (GNBi), 10 GNB nodular (GNBn) and 10 ganglioneuroma (GN); (group 2) 23 neural crest tumours with neuroendocrine differentiation [pheochromocytoma/paraganglioma (PCC/PG)]; (group 3) 27 other neural crest tumours including one composite rhabdomyosarcoma/neuroblastoma; and (group 4) 44 non-neural crest tumours. TH IHC was performed on groups 1, 2 and 3. Phox2b was expressed diffusely in pNT (n = 65 of 65), strongly in NB-UD and NB-PD and with less intensity in NB-D, GNB and GN. Diffuse TH was seen in all NB-PD, NB-D, GNB and GN, but nine of 15 NB-UD and a nodule in GNBn did not express TH (n = 55 of 65). PCC/PG expressed diffuse Phox2b (n = 23 of 23) and diffuse TH, except for one tumour (n = 22 of 23). In composite rhabdomyosarcoma, TH was expressed only in neuroblastic cells and Phox2b was diffusely positive in neuroblastic cells and focally in rhabdomyosarcoma. All other tumours were negative for Phox2b (n = none of 44). Phox2b was a specific and sensitive marker for pNT and PCC/PG, especially useful for identifying NB-UD often lacking TH. Our study also presented a composite rhabdomyosarcoma/neuroblastoma of neural crest origin. © 2017 John Wiley & Sons Ltd.

In-vitro characterization of 5-aminosalicylic acid release from MMX mesalamine tablets and determination of tablet coating thickness.

PubMed

Tenjarla, Srini; Abinusawa, Adeyinka

2011-01-01

Substantial variability in gastrointestinal pH is observed in patients with ulcerative colitis (UC). We characterized the effect of pH on 5-aminosalicylic acid (5-ASA) release from MMX mesalamine tablets (Shire Pharmaceuticals Inc., Wayne, PA, USA), examined thickness/uniformity of tablet film coatings, and explored the influence of simulating altered gastrointestinal motility. Nondestructive, three-dimensional, terahertz pulse imaging (TPI) was used to characterize the film coating of three lots of MMX mesalamine tablets (n=36). Thereafter, 5-ASA release from these tablets was evaluated using United States Pharmacopeia (USP) apparatus II at pH 6.8 and 7.2. Onset of tablet film-coat breach and mean dissolution time were determined for each lot. 5-ASA release was also assessed at three different paddle rotation speeds (50, 75, and 100 rpm) at pH 7.2. The mean ± SD film-coating thickness of the three lots of MMX mesalamine tablets were 109.2 ± 16.8, 113.1 ± 19.5, and 113.8 ± 19.8 μM, respectively. At pH 6.8 (100 rpm), the onset of film-coat breach was 10-30 minutes, whereas at pH 7.2 this was observed within 10 minutes. 5-ASA release was uniform at both pH conditions, with minimal lot-to-lot variability. Complete drug release was achieved within 6 hours under both pH conditions. 5-ASA release increased in proportion with paddle speed, but remained prolonged at all speeds. 5-ASA release from MMX mesalamine is unaffected by normal variations in simulated intracolonic pH. The dissolution profile of 5-ASA from MMX mesalamine tablets may be attributed to consistent outer film coatings and the hydrogel-forming matrix that controls the drug release after dissolution of the film coating.

Interaction of the dopants Mg and Si in Al xGa 1- x As/GaAs heterolayers (MOVPE): application to DQW laser structures

NASA Astrophysics Data System (ADS)

Korte, L.; Treichler, R.; Schreiber, M.; Tanner, Ch.; Kristen, G.; Hanke, C.; Weimann, G.

1991-01-01

The interaction of Mg and Si has been studied in GaAs/Al xGa 1- xAs DQW laser structures with a 50 nm Si diffusion barrier. The samples have been exposed to capless heat treatments at 860°C and under Si/SiO 2 and Si 3N 4 cap layers, and were analysed by SIMS. The Mg diffusion is highly dependent on the surface conditions during heating. A Si barrier is effective for temperature treatments under H 2/AsH 3 and Si/SiO 2. It is not effective under a Si 3N 4 cap where we detected very fast Mg diffusion. The Mg diffusion behaviour is discussed in terms of Si-Mg interaction and the influence of crystal defects.

Diffusion of organic pollutants within a biofilm in porous media

NASA Astrophysics Data System (ADS)

Fan, Chihhao; Kao, Chen-Fei; Liu, You-Hsi

2017-04-01

The occurrence of aquatic pollution is an inevitable environmental impact resulting from human civilization and societal advancement. Either from the natural or anthropogenic sources, the aqueous contaminants enter the natural environment and aggravate its quality. To assure the aquatic environment quality, the attached-growth biological degradation is often applied to removing organic contaminants by introducing contaminated water into a porous media which is covered by microorganism. Additionally, many natural aquatic systems also form such similar mechanism to increase their self-purification capability. To better understand this transport phenomenon and degradation mechanism in the biofilm for future application, the mathematic characterization of organic contaminant diffusion within the biofilm requires further exploration. The present study aimed to formulate a mathematic representation to quantify the diffusion of the organic contaminant in the biofilm. The BOD was selected as the target contaminant. A series of experiments were conducted to quantify the BOD diffusion in the biofilm under the conditions of influent BOD variation from 50 to 300 mg/L, COD:N:P ratios of 100:5:1 and 100:15:3, with or without auxiliary aeration. For diffusion coefficient calculation, the boundary condition of zero diffusion at the interface between microbial phase and contact media was assumed. With the principle of conservation of mass, the removed contaminants equal those that diffuse into the biofilm, and eq 1 results, and the diffusion coefficient (i.e., eq 2) can be solved through calculus with equations from table of integral. ∂2Sf- Df ∂z2 = Rf (1) --(QSin--QSout)2Y--- Df = 2μmaxxf(Sb + Ks ln-Ks-) Sb+Ks (2) Using the obtained experimental data, the diffusion coefficient was calculated to be 2.02*10-6 m2/d with influent COD of 50 mg/L at COD:N:P ratio of 100:5:1 with aeration, and this coefficient increased to 6.02*10-6 m2/d as the influent concentration increased to 300 mg/L. Meanwhile, the diffusion coefficient decreased to 2.61*10-7 m2/d as the retention time increased to 3 hours. Generally, the variation in diffusion coefficients between different COD:N:P ratios exhibits similar pattern with a slight decrease for the ratio of 100:15:3. The difference in diffusion coefficients between 1 and 2 hours was apparently greater than that between 2 and 3 hours, implying the diffusion was a critical factor for contaminant removal for the treatment condition with retention time of 1 hour or less, because higher retention time leads to better microbial degradation due to sufficient contact time for biological reactions. For 1 hour retention time, the increase in diffusion coefficient becomes limited as the influent COD concentration was equal to or above 150 mg/L. These obtained diffusion coefficients were applied to estimating the treatment efficiency for real domestic sewage. The result was found that the estimated effluent BOD concentrations were quite comparable to that obtained through experimental measurements.

7 CFR 29.35 - Lot seal.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 2 2010-01-01 2010-01-01 false Lot seal. 29.35 Section 29.35 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... INSPECTION Regulations Definitions § 29.35 Lot seal. A seal approved by the Director for sealing lots of...

7 CFR 29.35 - Lot seal.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 2 2011-01-01 2011-01-01 false Lot seal. 29.35 Section 29.35 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... INSPECTION Regulations Definitions § 29.35 Lot seal. A seal approved by the Director for sealing lots of...

Relaxation and Self-Diffusion of a Polymer Chain in a Melt

NASA Astrophysics Data System (ADS)

Hagita, Katsumi; Takano, Hiroshi

2004-04-01

Relaxation and self-diffusion of a polymer chain in a melt are discussed on the basis of the results of our recent Monte Carlo simulations of the bond fluctuation model, where only the excluded volume interaction is considered. Polymer chains are located on an L × L × L simple cubic lattice under periodic boundary conditions. Each chain consists of N segments, each of which occupies 2 × 2 × 2 unit cells. The results for N = 32, 48, 64, 96, 128, 192, 256, 384 and 512 at the volume fraction φ ≃ 0.5 are examined, where L = 128 for N ⩽ 256 and L = 192 for N ⩾ 384. The longest relaxation time τ is estimated by solving generalized eigenvalue problems for the equilibrium time correlation matrices of the positions of segments of a polymer chain. The self-diffusion constant D is estimated from the mean square displacements of the center of mass of a single polymer chain at the times larger than τ. From the data for N = 256, 384 and 512, the apparent exponents x r and xd, which describe the power law dependences of τ and D on N as τ ∝ N xr and D ∝ N-xd, are estimated to be xr ≃ 3.5 and xd ≃ 2.4, respectively. For N = 192, 256, 384 and 512, Dτ/ appears to be a constant, where denotes the mean square end-to-end distance of a polymer chain.

Three distinct modes in a surface micro-discharge in atmospheric pressure He + N{sub 2} mixtures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Dong; Liu, Dingxin, E-mail: liudingxin@mail.xjtu.edu.cn; He, Tongtong

2015-12-15

A surface micro-discharge in atmospheric pressure He + N{sub 2} mixtures is studied in this paper with an emphasis on the discharge modes. With the N{sub 2} admixture increasing from 0.1% to 20%, the discharge evolves from a spatially diffuse mode to a filamentary mode during positive half-cycles of the applied voltage. However during the negative half-cycles, an additional patterned mode emerges between the diffuse and the filamentary modes, which has not been reported before to exist in surface micro-discharges. In the diffuse and patterned modes, the plasmas cover almost the entirety of the mesh area during one cycle after plasma ignitionmore » in all mesh elements, and the discharge power increases linearly with the applied voltage. In contrast, plasma coverage of the mesh area is only partial in the filamentary mode and the plasma is more unstable with the discharge power increasing exponentially with the applied voltage. As the surface micro-discharge evolves through the three modes, the density of excited species changes significantly, for instance, the density of N{sub 2}{sup +}(B) drops by ∼20-fold from [N{sub 2}] = 0.2% to 20%. The N{sub 2}{sup +}(B) is predicted to be generated mainly through successive processes of Penning ionization by helium metastables and electron-impact excitation of N{sub 2}{sup +}(X), the latter is most responsible for the density decrease of N{sub 2}{sup +}(B) because much more N{sub 2}{sup +}(X) is converted to N{sub 4}{sup +}(X) as the increase of N{sub 2} fraction. Also, the electron density and electron temperature decrease with the discharge mode transition.« less

40 CFR 85.2223 - On-board diagnostic test report.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 18 2010-07-01 2010-07-01 false On-board diagnostic test report. 85... Tests § 85.2223 On-board diagnostic test report. (a) Motorists whose vehicles fail the on-board diagnostic test described in § 85.2222 shall be provided with the on-board diagnostic test results, including...

40 CFR 85.2223 - On-board diagnostic test report.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 18 2011-07-01 2011-07-01 false On-board diagnostic test report. 85... Tests § 85.2223 On-board diagnostic test report. (a) Motorists whose vehicles fail the on-board diagnostic test described in § 85.2222 shall be provided with the on-board diagnostic test results, including...

78 FR 55717 - TRENDnet, Inc.; Analysis of Proposed Consent Order To Aid Public Comment

Federal Register 2010, 2011, 2012, 2013, 2014

2013-09-11

... Pennsylvania Avenue NW., Washington, DC 20580, either in person or by calling (202) 326- 2222. You can file a... interested persons. Comments received during this period will become part of the public record. After thirty..., increases consumers' susceptibility to physical tracking or stalking, and reduces consumers' ability to...

76 FR 78259 - Valeant Pharmaceuticals International, Inc.; Analysis of Agreement Containing Consent Order to...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-12-16

... online or on paper, by following the instructions in the Request for Comment part of the SUPPLEMENTARY... online at https://ftcpublic.commentworks.com/ftc/valeantsanoficonsent , by following the instructions on... calling (202) 326-2222. You can file a comment online or on paper. For the Commission to consider your...

Immunogenicity and safety of three consecutive production lots of the non replicating smallpox vaccine MVA: A randomised, double blind, placebo controlled phase III trial.

PubMed

Overton, Edgar Turner; Lawrence, Steven J; Wagner, Eva; Nopora, Katrin; Rösch, Siegfried; Young, Philip; Schmidt, Darja; Kreusel, Christian; De Carli, Sonja; Meyer, Thomas P; Weidenthaler, Heinz; Samy, Nathaly; Chaplin, Paul

2018-01-01

Modified Vaccinia Ankara (MVA) is a live, viral vaccine under advanced development as a non-replicating smallpox vaccine. A randomised, double-blind, placebo-controlled phase III clinical trial was conducted to demonstrate the humoral immunogenic equivalence of three consecutively manufactured MVA production lots, and to confirm the safety and tolerability of MVA focusing on cardiac readouts. The trial was conducted at 34 sites in the US. Vaccinia-naïve adults aged 18-40 years were randomly allocated to one of four groups using a 1:1:1:1 randomization scheme. Subjects received either two MVA injections from three consecutive lots (Groups 1-3), or two placebo injections (Group 4), four weeks apart. Everyone except personnel involved in vaccine handling and administration was blinded to treatment. Safety assessment focused on cardiac monitoring throughout the trial. Vaccinia-specific antibody titers were measured using a Plaque Reduction Neutralization Test (PRNT) and an Enzyme-Linked Immunosorbent Assay (ELISA). The primary immunogenicity endpoint was Geometric Mean Titers (GMTs) after two MVA vaccinations measured by PRNT at trial visit 4. This trial is registered with ClinicalTrials.gov, number NCT01144637. Between March 2013 and May 2014, 4005 subjects were enrolled and received at least one injection of MVA (n = 3003) or placebo (n = 1002). The three MVA lots induced equivalent antibody titers two weeks after the second vaccination, with seroconversion rates of 99·8% (PRNT) and 99·7% (ELISA). Overall, 180 (6·0%) subjects receiving MVA and 29 (2·9%) subjects in the placebo group reported at least one unsolicited Adverse Event (AE) that was considered trial-related. Vaccination was well tolerated without significant safety concerns, particularly regarding cardiac assessment. The neutralizing and total antibody titers induced by each of the three lots were equivalent. No significant safety concerns emerged in this healthy trial population, especially regarding cardiac safety, thus confirming the excellent safety and tolerability profile of MVA. ClinicalTrials.gov NCT01144637.

The C4H radical and the diffuse interstellar bands. An ab initio study

NASA Technical Reports Server (NTRS)

Kolbuszewski, Marcin

1994-01-01

An ab initio study of the low-lying electronic states of C4H has been presented where the species studied has a chi(2)sigma(+) ground state and two low lying pi states. Based on the vertical and adiabatic excitation energies between those states it is suggested that the 4428 A diffuse interstellar band is not carried by C4H. The application of the particle in a box model shows strong coincidences between the strong DIB's and predicted wavelengths of pi-pi transitions in C(2n)H series. Based on those coincidences, it is suggested the C(2n)H species as good candidates for carriers of diffuse interstellar bands.

Increase in the diffusion length of minority carriers in Al{sub x}Ga{sub 1–x}N alloys ({sub x} = 0–0.1) fabricated by ammonia molecular beam epitaxy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Malin, T. V., E-mail: mal-tv@mail.ru; Gilinsky, A. M.; Mansurov, V. G.

2015-10-15

The room-temperature diffusion length of minority carriers in n-Al{sub 0.1}Ga{sub 0.9}N layers grown by ammonia molecular beam epitaxy on sapphire (0001) substrates used in structures for ultraviolet photodetectors is studied. Measurements were performed using the spectral dependence of the photocurrent recorded in a built-in p–n junction for thin samples and using the induced electron-current procedure for films up to 2 µm thick. The results show that the hole diffusion length in n-AlGaN films is 120–150 nm, which is larger than in GaN films grown under similar growth conditions by a factor of 3–4. This result can be associated with themore » larger lateral sizes characteristic of hexagonal columns in AlGaN layers grown by molecular beam epitaxy. No increase in the hole diffusion length is observed for thicker films.« less

Coal-Tar-Sealcoated Parking Lots: "Hot spots" of PAHs and N-heterocycles to Urban Streams and Lakes Result in "Hot Moments" of Toxicity

NASA Astrophysics Data System (ADS)

Mahler, B. J.; Van Metre, P. C.; Ingersoll, C.; Kunz, J. L.

2014-12-01

Coal-tar (CT) sealcoat, a potent source of polycyclic aromatic hydrocarbons (PAHs) and N-heterocycles, is applied to asphalt pavement of parking lots and driveways in many parts of the U.S. and Canada every 1 to 5 years. We measured the chemistry and toxicity of unfiltered runoff resulting from rain events simulated from 5 hours to 111 days after application of CT or asphalt (AS) sealcoat. PAHs and N-heterocycles were measured by GC/EIMS. Toxicity tests were done with Ceriodaphnia dubia and Pimephales promelas exposed 48 hours to undiluted and diluted (1 part runoff 9 parts control water) runoff under ambient lighting. Organisms were then transferred to fresh control water and subjected to a 4-hour pulse of ultraviolet radiation (UVR). Concentrations of 2- and 3-ringed PAHs and N-heterocycles in CT runoff, initially high (sum of 6 PAHs, 220 μg/L; sum of 7 N-heterocycles, 904 μg/L), decreased rapidly, whereas concentrations of 4-, 5- and 6-ringed PAHs more than doubled by 7 days after application (sum of 9 PAHs, 378 μg/L) and remained elevated 111 days after application (sum of 9 PAHs, 283 μg/L). Concentrations of PAHs and N-heterocycles in AS sealcoated runoff followed a similar pattern, but were ~10 times lower than those in CT runoff; concentrations in a sample of runoff from unsealed asphalt pavement were near or less than the detection limit. Organisms exposed to samples of undiluted CT-runoff collected during the 36 days following CT sealcoat application (no UVR exposure) experienced 100% mortality. Mortality (as much as 100%) of organisms exposed to the 10% dilution of CT runoff or to undiluted AS runoff occurred only with UVR; mortality of organisms exposed to the 10% solution of AS runoff and UVR was minimal. Results demonstrate that freshly CT-sealed parking lots and driveways are "hot spots" of PAH and N-heterocycle contamination and that prolonged "hot moments" of toxicity follow CT sealcoat application.

Model-free and analytical EAP reconstruction via spherical polar Fourier diffusion MRI.

PubMed

Cheng, Jian; Ghosh, Aurobrata; Jiang, Tianzi; Deriche, Rachid

2010-01-01

How to estimate the diffusion Ensemble Average Propagator (EAP) from the DWI signals in q-space is an open problem in diffusion MRI field. Many methods were proposed to estimate the Orientation Distribution Function (ODF) that is used to describe the fiber direction. However, ODF is just one of the features of the EAP. Compared with ODF, EAP has the full information about the diffusion process which reflects the complex tissue micro-structure. Diffusion Orientation Transform (DOT) and Diffusion Spectrum Imaging (DSI) are two important methods to estimate the EAP from the signal. However, DOT is based on mono-exponential assumption and DSI needs a lot of samplings and very large b values. In this paper, we propose Spherical Polar Fourier Imaging (SPFI), a novel model-free fast robust analytical EAP reconstruction method, which almost does not need any assumption of data and does not need too many samplings. SPFI naturally combines the DWI signals with different b-values. It is an analytical linear transformation from the q-space signal to the EAP profile represented by Spherical Harmonics (SH). We validated the proposed methods in synthetic data, phantom data and real data. It works well in all experiments, especially for the data with low SNR, low anisotropy, and non-exponential decay.

Analysis of Al diffusion processes in TiN barrier layers for the application in silicon solar cell metallization

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kumm, J.; Samadi, H.; Chacko, R. V.

An evaporated Al layer is known as an excellent rear metallization for highly efficient solar cells, but suffers from incompatibility with a common solder process. To enable solar cell-interconnection and module integration, in this work the Al layer is complemented with a solder stack of TiN/Ti/Ag or TiN/NiV/Ag, in which the TiN layer acts as an Al diffusion barrier. X-ray photoelectron spectroscopy measurements prove that diffusion of Al through the stack and the formation of an Al{sub 2}O{sub 3} layer on the stack's surface are responsible for a loss of solderability after a strong post-metallization anneal, which is often mandatorymore » to improve contact resistance and passivation quality. An optimization of the reactive TiN sputter process results in a densification of the TiN layer, which improves its barrier quality against Al diffusion. However, measurements with X-ray diffraction and scanning electron microscopy show that small grains with vertical grain boundaries persist, which still offer fast diffusion paths. Therefore, the concept of stuffing is introduced. By incorporating oxygen into the grain boundaries of the sputtered TiN layer, Al diffusion is strongly reduced as confirmed by secondary ion mass spectroscopy profiles. A quantitative analysis reveals a one order of magnitude lower Al diffusion coefficient for stuffed TiN layers. This metallization system maintains its solderability even after strong post-metallization annealing at 425 °C for 15 min. This paper thus presents an industrially feasible, conventionally solderable, and long-term stable metallization scheme for highly efficient silicon solar cells.« less

Aspects of Superconformal Field Theories

NASA Astrophysics Data System (ADS)

Gadde, Abhijit

Recently, a lot of progress has been made towards understanding the strongly coupled supersymmetric quantum gauge theories. The problem of strong coupling for SU(N) gauge theories can be formulated in two separate regimes of interest, one at finite N and the other at large N in 't Hooft limit. In the first case electric/magnetic duality also called S-duality and in the second, AdS/CFT duality map the strongly coupled problem to a weakly coupled one. Both of the dualities have been well understood in the maximally supersymmetric 4 d gauge theory, the N = 4 super Yang-Mills. In this thesis, as a natural next step, we focus on the strong coupling behavior in N = 2 supersymmetric gauge theories.

Understanding the Links Between Self-Report Emotional Intelligence and Suicide Risk: Does Psychological Distress Mediate This Relationship Across Time and Samples?

PubMed Central

Mérida-López, Sergio; Extremera, Natalio; Rey, Lourdes

2018-01-01

Objective: In the last decades, increasing attention has been paid to examining psychological resources that might contribute to our understanding of suicide risk. Although Emotional Intelligence (EI) is one dimension that has been linked with decreased suicidal ideation and behaviors, we detected several gaps in the literature in this area regarding the research designs and samples involved. In this research, we aimed to test a mediator model considering self-report EI, psychological distress and suicide risk across samples adopting both cross-sectional and prospective designs in two independent studies. Method: In Study 1, our purpose was to examine the potential role of psychological distress as a mediator in the relationship between self-report EI and suicide risk in a community sample comprised of 438 adults (270 women; mean age: 33.21 years). In Study 2, we sought to examine the proposed mediator model considering a 2-month prospective design in a sample of college students (n = 330 in T1; n = 311 in T2; 264 women; mean age: 22.22 years). Results: In Study 1, we found that psychological distress partially mediated the effect of self-report EI on suicide risk. More interestingly, findings from Study 2 showed that psychological distress fully mediated the relationship between self-report EI and suicide risk at Time 2. Conclusion: These results point out the role of psychological distress as a mediator in the association between self-report EI and suicide risk. These findings suggest an underlying process by which self-report EI may act as a protective factor against suicidal ideation and behaviors. In line with the limitations of our work, plausible avenues for future research and interventions are discussed. PMID:29867607

Effect of Crystal Defects on Minority Carrier Diffusion Length in 6H SiC Measured Using the Electron Beam Induced Current Method

NASA Technical Reports Server (NTRS)

Tabib-Azar, Massood

1997-01-01

We report values of minority carrier diffusion length in n-type 6H SiC measured using a planar Electron Beam Induced Current (EBIC) method. Values of hole diffusion length in defect free regions of n-type 6H SiC, with a doping concentration of 1.7El7 1/cu cm, ranged from 1.46 microns to 0.68 microns. We next introduce a novel variation of the planar method used above. This 'planar mapping' technique measured diffusion length along a linescan creating a map of diffusion length versus position. This map is then overlaid onto the EBIC image of the corresponding linescan, allowing direct visualization of the effect of defects on minority carrier diffusion length. Measurements of the above n-type 6H SiC resulted in values of hole diffusion length ranging from 1.2 micron in defect free regions to below 0.1 gm at the center of large defects. In addition, measurements on p-type 6H SiC resulted in electron diffusion lengths ranging from 1.42 micron to 0.8 micron.

Vibrio vulnificus and Vibrio parahaemolyticus in U.S. retail shell oysters: a national survey from June 1998 to July 1999.

PubMed

Cook, David W; Oleary, Paul; Hunsucker, Jeff C; Sloan, Edna M; Bowers, John C; Blodgett, Robert J; Depaola, Angelo

2002-01-01

From June 1998 to July 1999, 370 lots of oysters in the shell were sampled at 275 different establishments (71%, restaurants or oyster bars; 27%, retail seafood markets: and 2%, wholesale seafood markets) in coastal and inland markets throughout the United States. The oysters were harvested from the Gulf (49%). Pacific (14%), Mid-Atlantic (18%), and North Atlantic (11%) Coasts of the United States and from Canada (8%). Densities of Vibrio vulnificus and Vibrio parahaemolyticus were determined using a modification of the most probable number (MPN) techniques described in the Food and Drug Administration's Bacteriological Analytical Manual. DNA probes and enzyme immunoassay were used to identify suspect isolates and to determine the presence of the thermostable direct hemolysin gene associated with pathogenicity of V. parahaemolyticus. Densities of both V. vulnifcus and V. parahaemolyticus in market oysters from all harvest regions followed a seasonal distribution, with highest densities in the summer. Highest densities of both organisms were observed in oysters harvested from the Gulf Coast, where densities often exceeded 10,000 MPN/g. The majority (78%) of lots harvested in the North Atlantic, Pacific, and Canadian Coasts had V. vulnificus densities below the detectable level of 0.2 MPN/g; none exceeded 100 MPN/g. V. parahaemolyticus densities were greater than those of V. vulnificus in lots from these same areas, with some lots exceeding 1,000 MPN/g for V. parahaemolyticus. Some lots from the Mid-Atlantic states exceeded 10,000 MPN/g for both V. vulnificus and V. parahaemolyicus. Overall, there was a significant correlation between V. vulificus and V. parahaemolyticus densities (r = 0.72, n = 202, P < 0.0001), but neither density correlated with salinity. Storage time significantly affected the V. vulnificus (10% decrease per day) and V. parahaemolyticus (7% decrease per day) densities in market oysters. The thermostable direct hemolysin gene associated with V parahaemolyticus virulence was detected in 9 of 3,429 (0.3%) V. parahaemolyticus cultures and in 8 of 198 (4.0%) lots of oysters. These data can be used to estimate the exposure of raw oyster consumers to V. vulnificus and V. parahaemolyticus.

21 CFR 610.2 - Requests for samples and protocols; official release.

Code of Federal Regulations, 2010 CFR

2010-04-01

... Biologics Evaluation and Research, a manufacturer shall not distribute a lot of a product until the lot is... Evaluation and Research, a manufacturer shall not distribute a lot of a biological product until the lot is... 21 Food and Drugs 7 2010-04-01 2010-04-01 false Requests for samples and protocols; official...

21 CFR 610.2 - Requests for samples and protocols; official release.

Code of Federal Regulations, 2011 CFR

2011-04-01

... Biologics Evaluation and Research, a manufacturer shall not distribute a lot of a product until the lot is... Evaluation and Research, a manufacturer shall not distribute a lot of a biological product until the lot is... 21 Food and Drugs 7 2011-04-01 2010-04-01 true Requests for samples and protocols; official...

Leapfrog Diffusion Mechanism for One-Dimensional Chains on Missing-Row Reconstructed Surfaces

NASA Astrophysics Data System (ADS)

Montalenti, F.; Ferrando, R.

1999-02-01

We analyze the in-channel diffusion of dimers and longer n-adatom chains on Au and Pt (110) \\(1×2\\) surfaces by molecular dynamics simulations. From our calculations it arises that, on the missing-row reconstructed surface, a novel diffusion process, called leapfrog, dominates over concerted jumps, thus becoming the most frequent diffusion mechanism.

The DnaJ-Like Zinc-Finger Protein HCF222 Is Required for Thylakoid Membrane Biogenesis in Plants1[OPEN

PubMed Central

Hartings, Stephanie; Paradies, Susanne; Karnuth, Bianca; Eisfeld, Sabrina; Mehsing, Jasmin; Wolff, Christian; Levey, Tatjana

2017-01-01

To understand the biogenesis of the thylakoid membrane in higher plants and to identify auxiliary proteins required to build up this highly complex membrane system, we have characterized the allelic nuclear mutants high chlorophyll fluorescence222-1 (hcf222-1) and hcf222-2 and isolated the causal gene by map-based cloning. In the ethyl methanesulfonate-induced mutant hcf222-1, the accumulation of the cytochrome b6f (Cytb6f) complex was reduced to 30% compared with the wild type. Other thylakoid membrane complexes accumulated to normal levels. The T-DNA knockout mutant hcf222-2 showed a more severe defect with respect to thylakoid membrane proteins and accumulated only 10% of the Cytb6f complex, accompanied by a reduction in photosystem II, the photosystem II light-harvesting complex, and photosystem I. HCF222 encodes a protein of 99 amino acids in Arabidopsis (Arabidopsis thaliana) that has similarities to the cysteine-rich zinc-binding domain of DnaJ chaperones. The insulin precipitation assay demonstrated that HCF222 has disulfide reductase activity in vitro. The protein is conserved in higher plants and bryophytes but absent in algae and cyanobacteria. Confocal fluorescence microscopy showed that a fraction of HCF222-green fluorescent protein was detectable in the endoplasmic reticulum but that it also could be recognized in chloroplasts. A fusion construct of HCF222 containing a plastid transit peptide targets the protein into chloroplasts and was able to complement the mutational defect. These findings indicate that the chloroplast-targeted HCF222 is indispensable for the maturation and/or assembly of the Cytb6f complex and is very likely involved in thiol-disulfide biochemistry at the thylakoid membrane. PMID:28572458

The DnaJ-Like Zinc-Finger Protein HCF222 Is Required for Thylakoid Membrane Biogenesis in Plants.

PubMed

Hartings, Stephanie; Paradies, Susanne; Karnuth, Bianca; Eisfeld, Sabrina; Mehsing, Jasmin; Wolff, Christian; Levey, Tatjana; Westhoff, Peter; Meierhoff, Karin

2017-07-01

To understand the biogenesis of the thylakoid membrane in higher plants and to identify auxiliary proteins required to build up this highly complex membrane system, we have characterized the allelic nuclear mutants high chlorophyll fluorescence222-1 ( hcf222-1 ) and hcf222-2 and isolated the causal gene by map-based cloning. In the ethyl methanesulfonate-induced mutant hcf222-1 , the accumulation of the cytochrome b 6 f (Cytb6f) complex was reduced to 30% compared with the wild type. Other thylakoid membrane complexes accumulated to normal levels. The T-DNA knockout mutant hcf222-2 showed a more severe defect with respect to thylakoid membrane proteins and accumulated only 10% of the Cytb6f complex, accompanied by a reduction in photosystem II, the photosystem II light-harvesting complex, and photosystem I. HCF222 encodes a protein of 99 amino acids in Arabidopsis ( Arabidopsis thaliana ) that has similarities to the cysteine-rich zinc-binding domain of DnaJ chaperones. The insulin precipitation assay demonstrated that HCF222 has disulfide reductase activity in vitro. The protein is conserved in higher plants and bryophytes but absent in algae and cyanobacteria. Confocal fluorescence microscopy showed that a fraction of HCF222-green fluorescent protein was detectable in the endoplasmic reticulum but that it also could be recognized in chloroplasts. A fusion construct of HCF222 containing a plastid transit peptide targets the protein into chloroplasts and was able to complement the mutational defect. These findings indicate that the chloroplast-targeted HCF222 is indispensable for the maturation and/or assembly of the Cytb6f complex and is very likely involved in thiol-disulfide biochemistry at the thylakoid membrane. © 2017 American Society of Plant Biologists. All Rights Reserved.

Time Delay Measurements for the Cluster-lensed Sextuple Quasar SDSS J2222+2745

NASA Astrophysics Data System (ADS)

Dahle, H.; Gladders, M. D.; Sharon, K.; Bayliss, M. B.; Rigby, J. R.

2015-11-01

We report first results from an ongoing monitoring campaign to measure time delays between the six images of the quasar SDSS J2222+2745, gravitationally lensed by a galaxy cluster. The time delay between A and B, the two most highly magnified images, is measured to be {τ }{{AB}}=47.7+/- 6.0 days (95% confidence interval), consistent with previous model predictions for this lens system. The strong intrinsic variability of the quasar also allows us to derive a time delay value of {τ }{{CA}}=722+/- 24 days between image C and A, in spite of modest overlap between their light curves in the current data set. Image C, which is predicted to lead all the other lensed quasar images, has undergone a sharp, monotonic flux increase of 60%-75% during 2014. A corresponding brightening is firmly predicted to occur in images A and B during 2016. The amplitude of this rise indicates that time delays involving all six known images in this system, including those of the demagnified central images D-F, will be obtainable from further ground-based monitoring of this system during the next few years. Based on observations made with the Nordic Optical Telescope, operated on the island of La Palma jointly by Denmark, Finland, Iceland, Norway, and Sweden, in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofisica de Canarias, and including observations obtained at the Gemini Observatory, which is operated by the Association of Universities for Research in Astronomy, Inc., under a cooperative agreement with the NSF on behalf of the Gemini partnership: the National Science Foundation (United States), the National Research Council (Canada), CONICYT (Chile), the Australian Research Council (Australia), Ministério da Ciência, Tecnologia e Inovação (Brazil) and Ministerio de Ciencia, Tecnologi´a e Innovación Productiva (Argentina).

Thermodiffusion, molecular diffusion and Soret coefficient of binary and ternary mixtures of n-hexane, n-dodecane and toluene.

PubMed

Alonso de Mezquia, David; Wang, Zilin; Lapeira, Estela; Klein, Michael; Wiegand, Simone; Mounir Bou-Ali, M

2014-11-01

In this study, the thermodiffusion, molecular diffusion, and Soret coefficients of 12 binary mixtures composed of toluene, n-hexane and n-dodecane in the whole range of concentrations at atmospheric pressure and temperatures of 298.15 K and 308.15 K have been determined. The experimental measurements have been carried out using the Thermogravitational Column, the Sliding Symmetric Tubes and the Thermal Diffusion Forced Rayleigh Scattering techniques. The results obtained using the different techniques show a maximum deviation of 9% for the thermodiffusion coefficient, 8% for the molecular diffusion coefficient and 2% for the Soret coefficient. For the first time we report a decrease of the thermodiffusion coefficient with increasing ratio of the thermal expansion coefficient and viscosity for a binary mixture of an organic ring compound with a short n-alkane. This observation is discussed in terms of interactions between the different components. Additionally, the thermogravitational technique has been used to measure the thermodiffusion coefficients of four ternary mixtures consisting of toluene, n-hexane and n-dodecane at 298.15 K. In order to complete the study, the values obtained for the molecular diffusion coefficient in binary mixtures, and the thermodiffusion coefficient of binary and ternary mixtures have been compared with recently derived correlations.

Molecular mechanism of hydrocarbons binding to the metal–organic framework

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sun, Xiuquan; Wick, Collin D.; Thallapally, Praveen K.

The adsorption and diffusivity of methane, ethane, n-butane, n-hexane and cyclohexane in a metal organic framework (MOF) with the organic linker tetrakis[4-(carboxyphenyl)oxamethyl]methane, the metal salt, Zn2+, and organic pillar, 4,4’-bipyridin was studied using molecular dynamics simulations. For the n-alkanes, the longer the chain, the lower the free energy of adsorption, which was attributed to a greater number of contacts between the alkane and MOF. Cyclohexane had a slightly higher adsorption free energy than n-hexane. Furthermore, for cyclo- and n-hexane, there were no significant differences in adsorption free energies between systems with low to moderate loadings. The diffusivity of the n-alkanesmore » was found to strongly depend on chain length with slower diffusion for longer chains. Cyclohexane had no effective diffusion, suggesting that the selectivity the MOF has towards n-hexane over cyclohexane is the result of kinetics instead of energetics. This work was supported by the U.S. Department of Energy's (DOE) Office of Basic Energy Sciences, Chemical Sciences program. The Pacific Northwest National Laboratory is operated by Battelle for DOE.« less

Polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) in harbor sediments from Sea Lots, Port-of-Spain, Trinidad and Tobago.

PubMed

Mohammed, Azad; Peterman, Paul; Echols, Kathy; Feltz, Kevin; Tegerdine, George; Manoo, Anton; Maraj, Dexter; Agard, John; Orazio, Carl

2011-06-01

Concentrations of polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) were determined in nearshore marine surficial sediments from three locations in Trinidad. Sediments were sampled at Sea Lots on the west coast, in south Port-of-Spain Harbor, south of Sea Lots at Caroni Lagoon National Park, and on Trinidad's east coast at Manzanilla. Total PCB concentrations in Sea Lots sediments ranged from 62 to 601ng/g (dry weight {dw}), which was higher than at Caroni and Manzanilla, 13 and 8ng/g dw, respectively. Total OCP concentrations at Sea Lots were ranged from 44.5 to 145ng/g dw, compared with 13.1 and 23.8n/g (dw), for Caroni and Manzanilla respectively. The concentrations of PCBs and of some OCPs in sediments from Sea Lots were above the Canadian interim sediment quality guidelines. To date, this data is the first report on the levels of PCBs and other organochlorine compounds from Trinidad and Tobago. Copyright © 2011 Elsevier Ltd. All rights reserved.

Search with COPERNICUS for interstellar N/sub 2/ in diffuse clouds

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lutz, B.L.; Owen, T.; Snow, T.P. Jr.

1979-01-01

Multiple Copernicus scans of the rho'/sup 1/..sigma../sub u//sup +/--X/sup 1/..sigma../sub g//sup +/(0--0) and l/sup 1/Pi/sub u/--X/sup 1/..sigma../sub g//sup +/(0--0) band regions of N/sub 2/ in the spectra of delta Sco and epsilon Per result in upper limits of N (N/sub 2/) < or =1.0--3.8 x 10/sup 12/ cm/sup -2/ and N (N/sub 2/) < or =1.2--4.4 x 10/sup 12/ cm/sup -2/, respectively, depending upon the cloud temperature. These limits are consistent with the column densities expected from current chemical models for diffuse interstellar clouds, representing relative abundances with respect to hydrogen nuclei of N (N/sub 2/)/2N (H/sub 2/)+N (H I)more » < or =0.69--2.6 x 10/sup -9/ for delta Sco and < or =0.31--1.1 x 10/sup -8/ for epsilon Per.« less

The Importance of Reagent Lot Registration in External Quality Assurance/Proficiency Testing Schemes.

PubMed

Stavelin, Anne; Riksheim, Berit Oddny; Christensen, Nina Gade; Sandberg, Sverre

2016-05-01

Providers of external quality assurance (EQA)/proficiency testing schemes have traditionally focused on evaluation of measurement procedures and participant performance and little attention has been given to reagent lot variation. The aim of the present study was to show the importance of reagent lot registration and evaluation in EQA schemes. Results from the Noklus (Norwegian Quality Improvement of Primary Care Laboratories) urine albumin/creatinine ratio (ACR) and prothrombin time international normalized ratio (INR) point-of-care EQA schemes from 2009-2015 were used as examples in this study. The between-participant CV for Afinion ACR increased from 6%-7% to 11% in 3 consecutive surveys. This increase was caused by differences between albumin reagent lots that were also observed when fresh urine samples were used. For the INR scheme, the CoaguChek INR results increased with the production date of the reagent lots, with reagent lot medians increasing from 2.0 to 2.5 INR and from 2.7 to 3.3 INR (from the oldest to the newest reagent lot) for 2 control levels, respectively. These differences in lot medians were not observed when native patient samples were used. Presenting results from different reagent lots in EQA feedback reports can give helpful information to the participants that may explain their deviant EQA results. Information regarding whether the reagent lot differences found in the schemes can affect patient samples is important and should be communicated to the participants as well as to the manufacturers. EQA providers should consider registering and evaluating results from reagent lots. © 2016 American Association for Clinical Chemistry.

Control of Ga-oxide interlayer growth and Ga diffusion in SiO2/GaN stacks for high-quality GaN-based metal-oxide-semiconductor devices with improved gate dielectric reliability

NASA Astrophysics Data System (ADS)

Yamada, Takahiro; Watanabe, Kenta; Nozaki, Mikito; Yamada, Hisashi; Takahashi, Tokio; Shimizu, Mitsuaki; Yoshigoe, Akitaka; Hosoi, Takuji; Shimura, Takayoshi; Watanabe, Heiji

2018-01-01

A simple and feasible method for fabricating high-quality and highly reliable GaN-based metal-oxide-semiconductor (MOS) devices was developed. The direct chemical vapor deposition of SiO2 films on GaN substrates forming Ga-oxide interlayers was carried out to fabricate SiO2/GaO x /GaN stacked structures. Although well-behaved hysteresis-free GaN-MOS capacitors with extremely low interface state densities below 1010 cm-2 eV-1 were obtained by postdeposition annealing, Ga diffusion into overlying SiO2 layers severely degraded the dielectric breakdown characteristics. However, this problem was found to be solved by rapid thermal processing, leading to the superior performance of the GaN-MOS devices in terms of interface quality, insulating property, and gate dielectric reliability.

Dye adsorption mechanisms in TiO2 films, and their effects on the photodynamic and photovoltaic properties in dye-sensitized solar cells.

PubMed

Hwang, Kyung-Jun; Shim, Wang-Geun; Kim, Youngjin; Kim, Gunwoo; Choi, Chulmin; Kang, Sang Ook; Cho, Dae Won

2015-09-14

The adsorption mechanism for the N719 dye on a TiO2 electrode was examined by the kinetic and diffusion models (pseudo-first order, pseudo-second order, and intra-particle diffusion models). Among these methods, the observed adsorption kinetics are well-described using the pseudo-second order model. Moreover, the film diffusion process was the main controlling step of adsorption, which was analysed using a diffusion-based model. The photodynamic properties in dye-sensitized solar cells (DSSCs) were investigated using time-resolved transient absorption techniques. The photodynamics of the oxidized N719 species were shown to be dependent on the adsorption time, and also the adsorbed concentration of N719. The photovoltaic parameters (Jsc, Voc, FF and η) of this DSSC were determined in terms of the dye adsorption amounts. The solar cell performance correlates significantly with charge recombination and dye regeneration dynamics, which are also affected by the dye adsorption amounts. Therefore, the photovoltaic performance of this DSSC can be interpreted in terms of the adsorption kinetics and the photodynamics of oxidized N719.

A fast collocation method for a variable-coefficient nonlocal diffusion model

NASA Astrophysics Data System (ADS)

Wang, Che; Wang, Hong

2017-02-01

We develop a fast collocation scheme for a variable-coefficient nonlocal diffusion model, for which a numerical discretization would yield a dense stiffness matrix. The development of the fast method is achieved by carefully handling the variable coefficients appearing inside the singular integral operator and exploiting the structure of the dense stiffness matrix. The resulting fast method reduces the computational work from O (N3) required by a commonly used direct solver to O (Nlog ⁡ N) per iteration and the memory requirement from O (N2) to O (N). Furthermore, the fast method reduces the computational work of assembling the stiffness matrix from O (N2) to O (N). Numerical results are presented to show the utility of the fast method.

Spirometry, Static Lung Volumes, and Diffusing Capacity.

PubMed

Vaz Fragoso, Carlos A; Cain, Hilary C; Casaburi, Richard; Lee, Patty J; Iannone, Lynne; Leo-Summers, Linda S; Van Ness, Peter H

2017-09-01

Spirometric Z-scores from the Global Lung Initiative (GLI) rigorously account for age-related changes in lung function and are thus age-appropriate when establishing spirometric impairments, including a restrictive pattern and air-flow obstruction. However, GLI-defined spirometric impairments have not yet been evaluated regarding associations with static lung volumes (total lung capacity [TLC], functional residual capacity [FRC], and residual volume [RV]) and gas exchange (diffusing capacity). We performed a retrospective review of pulmonary function tests in subjects ≥40 y old (mean age 64.6 y), including pre-bronchodilator measures for: spirometry ( n = 2,586), static lung volumes by helium dilution with inspiratory capacity maneuver ( n = 2,586), and hemoglobin-adjusted single-breath diffusing capacity ( n = 2,508). Using multivariable linear regression, adjusted least-squares means (adj LS Means) were calculated for TLC, FRC, RV, and hemoglobin-adjusted single-breath diffusing capacity. The adj LS Means were expressed with and without height-cubed standardization and stratified by GLI-defined spirometry, including normal ( n = 1,251), restrictive pattern ( n = 663), and air-flow obstruction (mild, [ n = 128]; moderate, [ n = 150]; and severe, [ n = 394]). Relative to normal spirometry, restrictive-pattern had lower adj LS Means for TLC, FRC, RV, and hemoglobin-adjusted single-breath diffusing capacity ( P ≤ .001). Conversely, relative to normal spirometry, mild, moderate, and severe air-flow obstruction had higher adj LS Means for FRC and RV ( P < .001). However, only mild and moderate air-flow obstruction had higher adj LS Means for TLC ( P < .001), while only moderate and severe air-flow obstruction had higher adj LS Means for RV/TLC ( P < .001) and lower adj LS Means for hemoglobin-adjusted single-breath diffusing capacity ( P < .001). Notably, TLC (calculated as FRC + inspiratory capacity) was not increased in severe air-flow obstruction ( P ≥ .11) because inspiratory capacity decreased with increasing air-flow obstruction ( P < .001), thus opposing the increased FRC ( P < .001). Finally, P values were similar whether adj LS Means were height-cubed standardized. A GLI-defined spirometric restrictive pattern is strongly associated with a restrictive ventilatory defect (decreased TLC, FRC, and RV), while GLI-defined spirometric air-flow obstruction is strongly associated with hyperinflation (increased FRC) and air trapping (increased RV and RV/TLC). Both spirometric impairments were strongly associated with impaired gas exchange (decreased hemoglobin-adjusted single-breath diffusing capacity). Copyright © 2017 by Daedalus Enterprises.

Photometric model of diffuse surfaces described as a distribution of interfaced Lambertian facets.

PubMed

Simonot, Lionel

2009-10-20

The Lambertian model for diffuse reflection is widely used for the sake of its simplicity. Nevertheless, this model is known to be inaccurate in describing a lot of real-world objects, including those that present a matte surface. To overcome this difficulty, we propose a photometric model where the surfaces are described as a distribution of facets where each facet consists of a flat interface on a Lambertian background. Compared to the Lambertian model, it includes two additional physical parameters: an interface roughness parameter and the ratio between the refractive indices of the background binder and of the upper medium. The Torrance-Sparrow model--distribution of strictly specular facets--and the Oren-Nayar model--distribution of strictly Lambertian facets--appear as special cases.

Diffusion in silicate melts: III. Empirical models for multicomponent diffusion

NASA Astrophysics Data System (ADS)

Yan, Liang; Richter, Frank M.; Chamberlin, Laurinda

1997-12-01

Empirical models for multicomponent diffusion in an isotropic fluid were derived by splitting the component's dispersion velocity into two parts: (a) an intrinsic velocity which is proportional to each component's electrochemical potential gradient and independent of reference frame and (b) a net interaction velocity which is both model and reference frame dependent. Simple molecules (e.g., M pO q) were chosen as endmember components. The interaction velocity is assumed to be either the same for each component (leading to a common relaxation velocity U) or proportional to a common interaction force ( F). U or F is constrained by requiring no local buildup in either volume or charge. The most general form of the model-derived diffusion matrix [ D] can be written as a product of a model-dependent kinetic matrix [ L] and a model independent thermodynamic matrix [ G], [ D] = [ L] · [ G]. The elements of [ G] are functions of derivatives of chemical potential with respect to concentration. The elements of [ L] are functions of concentration and partial molar volume of the endmember components, Cio and Vio, and self diffusivity Di, and charge number zi of individual diffusing species. When component n is taken as the dependent variable they can be written in a common form L ij = D jδ ij + C io[V noD n - V joD j)A i + (p nz nD n - p jz jD j)B i] where the functional forms of the scaling factors Ai and Bi depend on the model considered. The off-diagonal element Lij ( i ≠ j) is directly proportional to the concentration of component i, and thus negligible when i is a dilute component. The salient feature of kinetic interaction or relaxation is to slow down larger (volume or charge) and faster diffusing components and to speed up smaller (volume or charge) and slower moving species, in order to prevent local volume or charge buildup. Empirical models for multicomponent diffusion were tested in the ternary system CaOAl 2O 3SiO 2 at 1500°C and 1 GPa over a large range of melt compositions. Model-derived diffusion matrices calculated using measured self diffusivities (Ca, Al, Si, and O), partial molar volumes, and activities were compared with experimentally derived diffusion matrices at two melt compositions. Chemical diffusion profiles computed using the model-derived diffusion matrices, accounting for the compositional dependency of self diffusivities and activity coefficients, were also compared with the experimentally measured ones. Good agreement was found between the ionic common-force model derived diffusion profiles and the experimentally measured ones. Secondary misfits could result from either inadequacies of the model or inaccuracies in activity-composition relationship. The results show that both kinetic interactions and thermodynamic nonideality contribute significantly to the observed diffusive coupling in the molten CaOAl 2O 3SiO 2.

Lithium and sodium adsorption properties of two-dimensional aluminum nitride

NASA Astrophysics Data System (ADS)

Sengupta, Amretashis

2018-09-01

In this work the lithiation and sodiation properties of 2-dimensional (2D) AlN sheets are studied from density functional theory (DFT) simulations. 2D AlN showed theoretical specific capacity of 500.8 and 385.3 mA h g-1, maximum open circuit voltage of 1.49 and 1.86 V and diffusion barriers 0.40 and 0.15 eV, for Li and Na adsorption respectively. The calculations show 2D AlN as a possible alternative as anode material in Li-ion and Na-ion batteries. Further the high specific capacity and small diffusion barriers for Na atoms can make 2D AlN useful in supercapacitors. The change in carrier transport properties due to Li/Na adsorption on monolayer AlN can also be useful in chemical/bio-sensors and nanoelectronics devices.

Enhanced gas absorption in the ionic liquid 1-n-hexyl-3-methylimidazolium bis(trifluoromethylsulfonyl)amide ([hmim][Tf2N]) confined in silica slit pores: a molecular simulation study.

PubMed

Shi, Wei; Luebke, David R

2013-05-07

Two-dimensional NPxyT and isostress-osmotic (N2PxyTf1) Monte Carlo simulations were used to compute the density and gas absorption properties of the ionic liquid (IL) 1-n-hexyl-3-methylimidazolium bis(trifluoromethylsulfonyl)amide ([hmim][Tf2N]) confined in silica slit pores (25-45 Å). Self-diffusivity values for both gas and IL were calculated from NVE molecular dynamics simulations using both smooth and atomistic potential models for silica. The simulations showed that the molar volume of [hmim][Tf2N] confined in 25-45-Å silica slit pores is 12-31% larger than that of the bulk IL at 313-573 K and 1 bar. The amounts of CO2, H2, and N2 absorbed in the confined IL are 1.1-3 times larger than those in the bulk IL because of the larger molar volume of the confined IL compared to the bulk IL. The CO2, N2, and H2 molecules are generally absorbed close to the silica wall where the IL density is very low. This arrangement causes the self-diffusivities of these gases in the confined IL to be 2-8 times larger than those in the bulk IL at 298-573 K. The solubilities of water in the confined and bulk ILs are similar, which is likely due to strong water interactions with [hmim][Tf2N] through hydrogen bonding, so that the molar volume of the confined IL plays a less important role in determining the H2O solubility. Water molecules are largely absorbed in the IL-rich region rather than close to the silica wall. The self-diffusivities of water correlate with those of the confined IL. The confined IL exhibits self-diffusivities larger than those of the bulk IL at lower temperatures, but smaller than those of the bulk IL at higher temperatures. The findings from our simulations are consistent with available experimental data for similar confined IL systems.

38 CFR 36.4255 - Loans for the acquisition of a lot.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 38 Pensions, Bonuses, and Veterans' Relief 2 2010-07-01 2010-07-01 false Loans for the acquisition of a lot. 36.4255 Section 36.4255 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS... of a lot. (a) A loan to finance all or part of the cost of acquisition by the veteran of a lot on...

38 CFR 36.4255 - Loans for the acquisition of a lot.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 38 Pensions, Bonuses, and Veterans' Relief 2 2013-07-01 2013-07-01 false Loans for the acquisition of a lot. 36.4255 Section 36.4255 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS... of a lot. (a) A loan to finance all or part of the cost of acquisition by the veteran of a lot on...

38 CFR 36.4255 - Loans for the acquisition of a lot.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 38 Pensions, Bonuses, and Veterans' Relief 2 2012-07-01 2012-07-01 false Loans for the acquisition of a lot. 36.4255 Section 36.4255 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS... of a lot. (a) A loan to finance all or part of the cost of acquisition by the veteran of a lot on...

38 CFR 36.4255 - Loans for the acquisition of a lot.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 38 Pensions, Bonuses, and Veterans' Relief 2 2011-07-01 2011-07-01 false Loans for the acquisition of a lot. 36.4255 Section 36.4255 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS... of a lot. (a) A loan to finance all or part of the cost of acquisition by the veteran of a lot on...

38 CFR 36.4255 - Loans for the acquisition of a lot.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 38 Pensions, Bonuses, and Veterans' Relief 2 2014-07-01 2014-07-01 false Loans for the acquisition of a lot. 36.4255 Section 36.4255 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS... of a lot. (a) A loan to finance all or part of the cost of acquisition by the veteran of a lot on...

The relations between network-operation and topological-property in a scale-free and small-world network with community structure

NASA Astrophysics Data System (ADS)

Ma, Fei; Yao, Bing

2017-10-01

It is always an open, demanding and difficult task for generating available model to simulate dynamical functions and reveal inner principles from complex systems and networks. In this article, due to lots of real-life and artificial networks are built from series of simple and small groups (components), we discuss some interesting and helpful network-operation to generate more realistic network models. In view of community structure (modular topology), we present a class of sparse network models N(t , m) . At the moment, we capture the fact the N(t , 4) has not only scale-free feature, which means that the probability that a randomly selected vertex with degree k decays as a power-law, following P(k) ∼k-γ, where γ is the degree exponent, but also small-world property, which indicates that the typical distance between two uniform randomly chosen vertices grows proportionally to logarithm of the order of N(t , 4) , namely, relatively shorter diameter and lower average path length, simultaneously displays higher clustering coefficient. Next, as a new topological parameter correlating to reliability, synchronization capability and diffusion properties of networks, the number of spanning trees over a network is studied in more detail, an exact analytical solution for the number of spanning trees of the N(t , 4) is obtained. Based on the network-operation, part hub-vertex linking with each other will be helpful for structuring various network models and investigating the rules related with real-life networks.

77 FR 6863 - Proposed Collection; Comment Request for VITA/TCE Program Forms

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-09

.../TCE Program Forms AGENCY: Internal Revenue Service (IRS), Treasury. ACTION: Notice and request for... VITA/TCE Program Forms 14310, 8653, 8654, and 14024. DATES: Written comments should be received on or... . SUPPLEMENTARY INFORMATION: Title: VITA/TCE Program Forms. OMB Number: 1545-2222. Form Number: Forms 14310, 8653...

77 FR 59939 - National Heart, Lung, and Blood Institute; Notice of Closed Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2012-10-01

... DEPARTMENT OF HEALTH AND HUMAN SERVICES National Institutes of Health National Heart, Lung, and... unwarranted invasion of personal privacy. Name of Committee: Heart, Lung, and Blood Initial Review Group... Heart, Lung, and Blood Institute, 6701 Rockledge Drive, Room 7190, Bethesda, MD 20892-7924, 301-435-2222...

Spectralon solar diffuser BRDF variation for NPP, JPSS J1 and J2

NASA Astrophysics Data System (ADS)

Murgai, Vijay; Johnson, Lindsay; Klein, Staci

2017-09-01

The Visible/Infrared Imaging Radiometer Suite (VIIRS) is a key sensor on the Suomi National Polar-orbiting Partnership (NPP) satellite as well as the upcoming Joint Polar Satellite System (JPSS). VIIRS collects Earth radiometric and imagery data in 22 spectral bands from 0.4 to 12.5 μm. Radiometric calibration of the reflective bands in the 0.4 to 2.5 μm wavelength range is performed by measuring the sunlight reflectance from Spectralon®. Reflected sun light is directly proportional to the Bidirectional Reflectance Distribution Function (BRDF) of the Spectralon. This paper presents the BRDF measurements of the Spectralon for JPSS J2 in the 0.4 - 1.63 μm wavelength using PASCAL (Polarization And Scatter Characterization Analysis of Lambertian materials) with an uncertainty better than 1.2%. PASCAL makes absolute measurements of the BRDF in an analogous fashion to the National Institute of Standards and Technology (NIST) Spectral Tri-function Automated Reflectance Reflectometer (STARR) facility. Unique additional features of this instrument include the ability to vary the sample elevation and roll / clock the sample about its normal, allowing measurement of BRDF in the as used geometry. Comparison of BRDF in the as used configuration for NPP, J1, and J2 shows variation of up to 3%. The sign of the change from panel to panel depends on the angle of incidence and view angle. The results demonstrate lot to lot variability in Spectralon and emphasize the necessity of characterizing each panel. A pattern in the BRDF variation is also presented.

Surface Morphology Evolution Mechanisms of InGaN/GaN Multiple Quantum Wells with Mixture N2/H2-Grown GaN Barrier.

PubMed

Zhou, Xiaorun; Lu, Taiping; Zhu, Yadan; Zhao, Guangzhou; Dong, Hailiang; Jia, Zhigang; Yang, Yongzhen; Chen, Yongkang; Xu, Bingshe

2017-12-01

Surface morphology evolution mechanisms of InGaN/GaN multiple quantum wells (MQWs) during GaN barrier growth with different hydrogen (H 2 ) percentages have been systematically studied. Ga surface-diffusion rate, stress relaxation, and H 2 etching effect are found to be the main affecting factors of the surface evolution. As the percentage of H 2 increases from 0 to 6.25%, Ga surface-diffusion rate and the etch effect are gradually enhanced, which is beneficial to obtaining a smooth surface with low pits density. As the H 2 proportion further increases, stress relaxation and H 2 over- etching effect begin to be the dominant factors, which degrade surface quality. Furthermore, the effects of surface evolution on the interface and optical properties of InGaN/GaN MQWs are also profoundly discussed. The comprehensive study on the surface evolution mechanisms herein provides both technical and theoretical support for the fabrication of high-quality InGaN/GaN heterostructures.

Dynamic and structural properties of room-temperature ionic liquids near silica and carbon surfaces.

PubMed

Li, Song; Han, Kee Sung; Feng, Guang; Hagaman, Edward W; Vlcek, Lukas; Cummings, Peter T

2013-08-06

The dynamic and structural properties of a room-temperature ionic liquid (RTIL) 1-butyl-3-methyl-imidazolium(trifluoromethanesulfonimide) ([C4mim][Tf2N]) confined in silica and carbon mesopores were investigated by molecular dynamics (MD) simulations and nuclear magnetic resonance (NMR) experiments. The complex interfacial microstructures of confined [C4mim][Tf2N] are attributed to the distinctive surface features of the silica mesopore. The temperature-dependent diffusion coefficients of [C4mim][Tf2N] confined in the silica or carbon mesopore exhibit divergent behavior. The loading fraction (f = 1.0, 0.5, and 0.25) has a large effect on the magnitude of the diffusion coefficient in the silica pore and displays weaker temperature dependence as the loading fraction decreases. The diffusion coefficients of mesoporous carbon-confined [C4mim][Tf2N] are relatively insensitive to the loading faction and exhibit a temperature dependence that is similar to the bulk dependence at all loading levels. Such phenomena can be attributed to the unique surface heterogeneity, dissimilar interfacial microstructures, and interaction potential profile of RTILs near silica and carbon walls.

Immunogenicity and safety of the candidate RTS,S/AS01 vaccine in young Nigerian children: a randomized, double-blind, lot-to-lot consistency trial.

PubMed

Umeh, Rich; Oguche, Stephen; Oguonu, Tagbo; Pitmang, Simon; Shu, Elvis; Onyia, Jude-Tony; Daniyam, Comfort A; Shwe, David; Ahmad, Abdullahi; Jongert, Erik; Catteau, Grégory; Lievens, Marc; Ofori-Anyinam, Opokua; Leach, Amanda

2014-11-12

For regulatory approval, consistency in manufacturing of vaccine lots is expected to be demonstrated in confirmatory immunogenicity studies using two-sided equivalence trials. This randomized, double-blind study (NCT01323972) assessed consistency of three RTS,S/AS01 malaria vaccine batches formulated from commercial-scale purified antigen bulk lots in terms of anti-CS-responses induced. Healthy children aged 5-17 months were randomized (1:1:1:1) to receive RTS,S/AS01 at 0-1-2 months from one of three commercial-scale purified antigen bulk lots (1600 litres-fermentation scale; commercial-scale lots), or a comparator vaccine batch made from pilot-scale purified antigen bulk lot (20 litres-fermentation scale; pilot-scale lot). The co-primary objectives were to first demonstrate consistency of antibody responses against circumsporozoite (CS) protein at one month post-dose 3 for the three commercial-scale lots and second demonstrate non-inferiority of anti-CS antibody responses at one month post-dose 3 for the commercial-scale lots compared to the pilot-scale lot. Safety and reactogenicity were evaluated as secondary endpoints. One month post-dose-3, anti-CS antibody geometric mean titres (GMT) for the 3 commercial scale lots were 319.6 EU/ml (95% confidence interval (CI): 268.9-379.8), 241.4 EU/ml (207.6-280.7), and 302.3 EU/ml (259.4-352.3). Consistency for the RTS,S/AS01 commercial-scale lots was demonstrated as the two-sided 95% CI of the anti-CS antibody GMT ratio between each pair of lots was within the range of 0.5-2.0. GMT of the pooled commercial-scale lots (285.8 EU/ml (260.7-313.3)) was non-inferior to the pilot-scale lot (271.7 EU/ml (228.5-323.1)). Each RTS,S/AS01 lot had an acceptable tolerability profile, with infrequent reports of grade 3 solicited symptoms. No safety signals were identified and no serious adverse events were considered related to vaccination. RTS,S/AS01 lots formulated from commercial-scale purified antigen bulk batches induced a consistent anti-CS antibody response, and the anti-CS GMT of pooled commercial-scale lots was non-inferior to that of a lot formulated from a pilot-scale antigen bulk batch. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

Determination of carrier diffusion length in GaN

NASA Astrophysics Data System (ADS)

Hafiz, Shopan; Zhang, Fan; Monavarian, Morteza; Avrutin, Vitaliy; Morkoç, Hadis; Özgür, Ümit; Metzner, Sebastian; Bertram, Frank; Christen, Jürgen; Gil, Bernard

2015-01-01

Diffusion lengths of photo-excited carriers along the c-direction were determined from photoluminescence (PL) and cross-sectional cathodoluminescence (CL) measurements in p- and n-type GaN epitaxial layers grown on c-plane sapphire by metal-organic chemical vapor deposition. The investigated samples incorporate a 6 nm thick In0.15Ga0.85N active layer capped with either 500 nm p-GaN or 1500 nm n-GaN. The top GaN layers were etched in steps and PL from the InGaN active region and the underlying layers was monitored as a function of the top GaN thickness upon photo-generation near the surface region by above bandgap excitation. Taking into consideration the absorption in the top GaN layer as well as active and underlying layers, the diffusion lengths at 295 K and at 15 K were measured to be 93 ± 7 nm and 70 ± 7 nm for Mg-doped p-type GaN and 432 ± 30 nm and 316 ± 30 nm for unintentionally doped n-type GaN, respectively, at photogenerated carrier densities of 4.2 × 1018 cm-3 using PL spectroscopy. CL measurements of the unintentionally doped n-type GaN layer at much lower carrier densities of 1017 cm-3 revealed a longer diffusion length of 525 ± 11 nm at 6 K.

Comparison of particle sizes between 238PuO 2 before aqueous processing, after aqueous processing, and after ball milling

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mulford, Roberta Nancy

Particle sizes determined for a single lot of incoming Russian fuel and for a lot of fuel after aqueous processing are compared with particle sizes measured on fuel after ball-milling. The single samples of each type are believed to have particle size distributions typical of oxide from similar lots, as the processing of fuel lots is fairly uniform. Variation between lots is, as yet, uncharacterized. Sampling and particle size measurement methods are discussed elsewhere.

Assessment of induced rat mammary tumour response to chemotherapy using the apparent diffusion coefficient of tissue water as determined by diffusion-weighted 1H-NMR spectroscopy in vivo.

PubMed

Lemaire, L; Howe, F A; Rodrigues, L M; Griffiths, J R

1999-03-01

Chemosensitivity of N-methyl-N-nitrosourea-induced rat mammary tumours treated with 5-fluorouracil at a dose of 100 mg kg(-1) i.p. was assessed by using diffusion-weighted 1H-MRS to measure the average diffusion coefficient (ADC) of water in the tumour tissue. ADC measurements prior to any therapy correlated positively with necrotic fraction. Tumours with low initial ADC (< 0.95 x 10(9) m2 s(-1)) showed an increase in ADC 7 days after treatment, whereas tumours with a high initial ADC (> 1.2 x 10(9) m2 s(-1)) showed a decrease. All tumours decreased significantly in volume (P < 0.05) 2, 5 and 7 days after treatment. At day 7 post-treatment, tumours with a high pre-treatment ADC started to regrow. The initial ADC value, as well as changes after treatment predict tumour chemosensitivity, which could be clinically relevant.

Vacant Lots: Productive Sites for Aedes (Stegomyia) aegypti (Diptera: Culicidae) in Mérida City, México

PubMed Central

BAAK-BAAK, CARLOS M.; ARANA-GUARDIA, ROGER; CIGARROA-TOLEDO, NOHEMI; LOROÑO-PINO, MARÍA ALBA; REYES-SOLIS, GUADALUPE; MACHAIN-WILLIAMS, CARLOS; BEATY, BARRY J.; EISEN, LARS; GARCÍA-REJÓN, JULIÁN E.

2014-01-01

We assessed the potential for vacant lots and other non-residential settings to serve as source environments for Aedes (Stegomyia) aegypti (L.) in Mérida City, México. Mosquito immatures were collected, during November 2011 – June 2013, from residential premises (n = 156 site visits) and non-residential settings represented by vacant lots (50), parking lots (18), and streets/sidewalks (28). Collections totaled 46,025 mosquito immatures of 13 species. Ae. aegypti was the most commonly encountered species accounting for 81.0% of total immatures, followed by Culex quinquefasciatus Say (12.1%). Site visits to vacant lots (74.0%) were more likely to result in collection of Ae. aegypti immatures that residential premises (35.9%). Tires accounted for 75.5% of Ae. aegypti immatures collected from vacant lots. Our data suggest that vacant lots should be considered for inclusion in mosquito surveillance and control efforts in Mérida City, as they often are located near homes, commonly have abundant vegetation, and frequently harbor accumulations of small and large discarded water-holding containers that we now have demonstrated to serve as development sites for immature mosquitoes. Additionally, we present data for associations of immature production with various container characteristics, such as storage capacity, water quality and physical location in the environment. PMID:24724299

In vitro germination of zygotic embryos of hybrid BRS Manicoré (E. guineensis X E. oleifera).

PubMed

Bonetti, Keila A P; Quoirin, Marguerite; Quisen, Regina C; Lima, Suelen C S

2016-01-01

The interspecific oil palm hybrid BRS Manicoré (E. guineensis x E. oleifera) has superior agronomic characteristics. However, the germination rate is low (30%) and the process is slow when the seeds are sown in a conventional form. The purpose of this study was to optimize the in vitro germination of zygotic embryos of this hybrid comparing seed lots. The viability of zygotic embryos was evaluated by the tetrazolium test (0.075%) for 4 h. The embryos were cultured on MS and Y3 culture media, with and without the addition of NaH2PO4, as well as on MS, MS1/2 and N6 medium. In MS medium containing NaH2PO4, the germination rate was increased from 40 to 70% in comparison with the medium without sodium phosphate. The comparison between the culture media MS, MS 1/2, N6 and Y3 showed that 75% of zygotic embryos cultured in the Y3 medium formed whole plants (with roots and shoots defined), a higher percentage than embryos cultured on MS, MS 1/2 and N6 media (46, 35 and 17% respectively). In the same Y3 culture medium, the embryos were larger (36% ≥ 2 cm and 30% ≥ 5 cm) than in the other media. Results obtained by the tetrazolium test were similar to those of germination, showing the effect of the genotype of each seed lot. For the germination and development of plantlets it is essential to add NaH2PO4 to a culture medium containing no phosphate or with a low phosphate concentration.

The Role of Skp1-Cul1-F-box Ubiquitin Ligases in Src-Stimulated Estrogen Receptor Proteolysis and Estrogen Receptor Target Gene Expression

DTIC Science & Technology

2014-03-01

encoded by ESR1 , is a steroid hormone receptor superfamily member1,2 that mediates oestrogen-stimulated proliferation in hormone-responsive cancers. ERα...cancer. Deletions, rearrangements and point mutations in ESR1 are too uncommon to account for ER– breast cancer20,21. MicroRNA 22 (miR-22)22, miR...222 (REF. 23), miR-221 (REF. 23), miR-206 (REF. 24) and miR-18a25 have been shown to target ESR1 . Increased miR-18a levels were observed more

North Atlantic OMEGA Navigation System Validation

DTIC Science & Technology

1980-07-21

Southeast Coast of Greenland c. Small triangular area between Iceland and Norway Winter Night: a. Extreme western part of Gulf of Mexico b. Southeast ...00 I c c i . IA.. ........ . . AWA. ~ ~ -;....... ... ~ ~ % i lot, oil N Io .. .....-.. .... .... 1 11~ 11 1 1 Ji l II...IW **.~.**..***.*A P HU.:* .0 Oil .4* 3 v .-.... ~IM I, * *. *... , C*.*.... IL. JI IL’ as 04 ......... !’ . ~ ~ . . .2 *................ 914~ 44 44

S{sub 2}SA preconditioning for the S{sub n} equations with strictly non negative spatial discretization

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bruss, D. E.; Morel, J. E.; Ragusa, J. C.

2013-07-01

Preconditioners based upon sweeps and diffusion-synthetic acceleration have been constructed and applied to the zeroth and first spatial moments of the 1-D S{sub n} transport equation using a strictly non negative nonlinear spatial closure. Linear and nonlinear preconditioners have been analyzed. The effectiveness of various combinations of these preconditioners are compared. In one dimension, nonlinear sweep preconditioning is shown to be superior to linear sweep preconditioning, and DSA preconditioning using nonlinear sweeps in conjunction with a linear diffusion equation is found to be essentially equivalent to nonlinear sweeps in conjunction with a nonlinear diffusion equation. The ability to use amore » linear diffusion equation has important implications for preconditioning the S{sub n} equations with a strictly non negative spatial discretization in multiple dimensions. (authors)« less

The effect of heat treatment on structural and electronic properties of niobium nitride prepared by a thermal diffusion method

DOE PAGES

Farha, Ashraf Hassan; Ozkendir, Osman Murat; Elsayed-Ali, Hani E.; ...

2016-11-15

NbN coatings are prepared onto Nb substrate by thermal diffusion at high temperatures. The formation of NbN coating by thermal diffusion was studied in the range of 1250-1500 °C at constant nitrogen background gas pressure (1.3x10 -3 Pa) and processing time (180 min). The electronic and crystal structures of the NbN coatings were investigated. It was found that nitrogen diffuses into Nb forming the Nb-N solid solution (bcc) a-NbN phase that starts to appear above 1250 °C. Increasing the processing temperature gives richer a-phase concentration. Besides, X-ray absorption spectroscopy (XAS) was performed to study the electronic structure of the NbNmore » layer. The results of the electronic structural study corroborate the crystal structural analysis. The Nb M 3,2 edge X-ray absorption spectroscopy (XAS) spectrum shows strong temperature dependence. At the highest processing temperature (1500 °C), the number of d holes increased. Nitrogen diffusion into Nb is resulting to increase electrostatic interaction between d electron and core hole. Lastly, for the studied conditions, only the α-NbN was observed in the X-ray diffraction patterns.« less

The effect of heat treatment on structural and electronic properties of niobium nitride prepared by a thermal diffusion method

DOE Office of Scientific and Technical Information (OSTI.GOV)

Farha, Ashraf Hassan; Ozkendir, Osman Murat; Elsayed-Ali, Hani E.

NbN coatings are prepared onto Nb substrate by thermal diffusion at high temperatures. The formation of NbN coating by thermal diffusion was studied in the range of 1250-1500 °C at constant nitrogen background gas pressure (1.3x10 -3 Pa) and processing time (180 min). The electronic and crystal structures of the NbN coatings were investigated. It was found that nitrogen diffuses into Nb forming the Nb-N solid solution (bcc) a-NbN phase that starts to appear above 1250 °C. Increasing the processing temperature gives richer a-phase concentration. Besides, X-ray absorption spectroscopy (XAS) was performed to study the electronic structure of the NbNmore » layer. The results of the electronic structural study corroborate the crystal structural analysis. The Nb M 3,2 edge X-ray absorption spectroscopy (XAS) spectrum shows strong temperature dependence. At the highest processing temperature (1500 °C), the number of d holes increased. Nitrogen diffusion into Nb is resulting to increase electrostatic interaction between d electron and core hole. Lastly, for the studied conditions, only the α-NbN was observed in the X-ray diffraction patterns.« less

Accelerated ions and self-excited Alfvén waves at the Earth's bow shock

NASA Astrophysics Data System (ADS)

Berezhko, E. G.; Taneev, S. N.; Trattner, K. J.

2011-07-01

The diffuse energetic ion event and related Alfvén waves upstream of the Earth's bow shock, measured by AMPTE/IRM satellite on 29 September 1984, 06:42-07:22 UT, was studied using a self-consistent quasi-linear theory of ion diffusive shock acceleration and associated Alfvén wave generation. The wave energy density satisfies a wave kinetic equation, and the ion distribution function satisfies the diffusive transport equation. These coupled equations are solved numerically, and calculated ion and wave spectra are compared with observations. It is shown that calculated steady state ion and Alfvén wave spectra are established during the time period of about 1000 s. Alfvén waves excited by accelerated ions are confined within the frequency range (10-2 to 1) Hz, and their spectral peak with the wave amplitude δB ≈ B comparable to the interplanetary magnetic field value B corresponds to the frequency 2 × 10-2 Hz. The high-frequency part of the wave spectrum undergoes absorption by thermal protons. It is shown that the observed ion spectra and the associated Alfvén wave spectra are consistent with the theoretical prediction.

The high temperature creep deformation of Si3N4-6Y2O3-2Al2O3

NASA Technical Reports Server (NTRS)

Todd, J. A.; Xu, Zhi-Yue

1988-01-01

The creep properties of silicon nitride containing 6 wt percent yttria and 2 wt percent alumina have been determined in the temperature range 1573 to 1673 K. The stress exponent, n, in the equation epsilon dot varies as sigma sup n, was determined to be 2.00 + or - 0.15 and the true activation energy was found to be 692 + or - 25 kJ/mol. Transmission electron microscopy studies showed that deformation occurred in the grain boundary glassy phase accompanied by microcrack formation and cavitation. The steady state creep results are consistent with a diffusion controlled creep mechanism involving nitrogen diffusion through the grain boundary glassy phase.

Thickness engineering of atomic layer deposited Al2O3 films to suppress interfacial reaction and diffusion of Ni/Au gate metal in AlGaN/GaN HEMTs up to 600 °C in air

NASA Astrophysics Data System (ADS)

Suria, Ateeq J.; Yalamarthy, Ananth Saran; Heuser, Thomas A.; Bruefach, Alexandra; Chapin, Caitlin A.; So, Hongyun; Senesky, Debbie G.

2017-06-01

In this paper, we describe the use of 50 nm atomic layer deposited (ALD) Al2O3 to suppress the interfacial reaction and inter-diffusion between the gate metal and semiconductor interface, to extend the operation limit up to 600 °C in air. Suppression of diffusion is verified through Auger electron spectroscopy (AES) depth profiling and X-ray diffraction (XRD) and is further supported with electrical characterization. An ALD Al2O3 thin film (10 nm and 50 nm), which functions as a dielectric layer, was inserted between the gate metal (Ni/Au) and heterostructure-based semiconductor material (AlGaN/GaN) to form a metal-insulator-semiconductor high electron mobility transistor (MIS-HEMT). This extended the 50 nm ALD Al2O3 MIS-HEMT (50-MIS) current-voltage (Ids-Vds) and gate leakage (Ig,leakage) characteristics up to 600 °C. Both, the 10 nm ALD Al2O3 MIS-HEMT (10-MIS) and HEMT, failed above 350 °C, as evidenced by a sudden increase of approximately 50 times and 5.3 × 106 times in Ig,leakage, respectively. AES on the HEMT revealed the formation of a Ni-Au alloy and Ni present in the active region. Additionally, XRD showed existence of metal gallides in the HEMT. The 50-MIS enables the operation of AlGaN/GaN based electronics in oxidizing high-temperature environments, by suppressing interfacial reaction and inter-diffusion of the gate metal with the semiconductor.

Field performance of a porous asphaltic pavement.

DOT National Transportation Integrated Search

1992-01-01

The Virginia Department of Transportation constructed a 2.52-acre parking lot of porous asphaltic pavement in Warrenton, Virginia. Runoff from the lot was collected and monitored for quantity, detention time, and quality. Prior to the lot opening for...

White matter microstructure on diffusion tensor imaging is associated with conventional magnetic resonance imaging findings and cognitive function in adolescents born preterm

PubMed Central

FELDMAN, HEIDI M; LEE, ELIANA S; LOE, IRENE M; YEOM, KRISTEN W; GRILL-SPECTOR, KALANIT; LUNA, BEATRIZ

2013-01-01

AIM Diffusion tensor imaging (DTI) was used to evaluate white matter architecture after preterm birth. The goals were (1) to compare white matter microstructure in two cohorts of preterm- and term-born children; and (2) within preterm groups, to determine if sex, gestational age, birthweight, white matter injury score from conventional magnetic resonance imaging (MRI), or IQ was associated with DTI measures. METHOD Participants (n=121; 66 females, 55 males) were aged 9 to 16 years. They comprised 58 preterm children (site 1, n=25; and site 2, n=33) born at less than 36 weeks’ gestation (mean 29.4wks; birthweight 1289g) and 63 term children (site 1, n=40; site 2, n=23) born at more than 37 weeks’ gestation. DTI was analyzed using tract-based spatial statistics. Diffusion measures were fractional anisotropy, axial, radial, and mean diffusivity. RESULTS In no region of the white matter skeleton was fractional anisotropy lower in the preterm group at either site. Within the preterm groups, fractional anisotropy was significantly associated with white matter injury score, but not sex, gestational age, or birthweight. At site 1, fractional anisotropy was associated with IQ. INTERPRETATION DTI contributes to understanding individual differences after preterm birth but may not differentiate a relatively high-functioning group of preterm children from a matched group of term-born children. PMID:22803787

Prioritization of candidate disease genes by topological similarity between disease and protein diffusion profiles.

PubMed

Zhu, Jie; Qin, Yufang; Liu, Taigang; Wang, Jun; Zheng, Xiaoqi

2013-01-01

Identification of gene-phenotype relationships is a fundamental challenge in human health clinic. Based on the observation that genes causing the same or similar phenotypes tend to correlate with each other in the protein-protein interaction network, a lot of network-based approaches were proposed based on different underlying models. A recent comparative study showed that diffusion-based methods achieve the state-of-the-art predictive performance. In this paper, a new diffusion-based method was proposed to prioritize candidate disease genes. Diffusion profile of a disease was defined as the stationary distribution of candidate genes given a random walk with restart where similarities between phenotypes are incorporated. Then, candidate disease genes are prioritized by comparing their diffusion profiles with that of the disease. Finally, the effectiveness of our method was demonstrated through the leave-one-out cross-validation against control genes from artificial linkage intervals and randomly chosen genes. Comparative study showed that our method achieves improved performance compared to some classical diffusion-based methods. To further illustrate our method, we used our algorithm to predict new causing genes of 16 multifactorial diseases including Prostate cancer and Alzheimer's disease, and the top predictions were in good consistent with literature reports. Our study indicates that integration of multiple information sources, especially the phenotype similarity profile data, and introduction of global similarity measure between disease and gene diffusion profiles are helpful for prioritizing candidate disease genes. Programs and data are available upon request.

Proton irradiation effects on minority carrier diffusion length and defect introduction in homoepitaxial and heteroepitaxial n-GaN [Proton irradiation effects on minority carrier diffusion length and defect introduction in homoepitaxial n-GaN

DOE Office of Scientific and Technical Information (OSTI.GOV)

Collins, K. C.; Armstrong, Andrew M.; Allerman, Andrew A.

Here, inherent advantages of wide bandgap materials make GaN-based devices attractive for power electronics and applications in radiation environments. Recent advances in the availability of wafer-scale, bulk GaN substrates have enabled the production of high quality, low defect density GaN devices, but fundamental studies of carrier transport and radiation hardness in such devices are lacking. Here, we report measurements of the hole diffusion length in low threading dislocation density (TDD), homoepitaxial n-GaN, and high TDD heteroepitaxial n-GaN Schottky diodes before and after irradiation with 2.5 MeV protons at fluences of 4–6 × 10 13 protons/cm 2. We also characterize themore » specimens before and after irradiation using electron beam-induced-current (EBIC) imaging, cathodoluminescence, deep level optical spectroscopy (DLOS), steady-state photocapacitance, and lighted capacitance-voltage (LCV) techniques. We observe a substantial reduction in the hole diffusion length following irradiation (50%–55%) and the introduction of electrically active defects which could be attributed to gallium vacancies and associated complexes (V Ga-related), carbon impurities (C-related), and gallium interstitials (Ga i). EBIC imaging suggests long-range migration and clustering of radiation-induced point defects over distances of ~500 nm, which suggests mobile Ga i. Following irradiation, DLOS and LCV reveal the introduction of a prominent optical energy level at 1.9 eV below the conduction band edge, consistent with the introduction of Ga i.« less

Proton irradiation effects on minority carrier diffusion length and defect introduction in homoepitaxial and heteroepitaxial n-GaN [Proton irradiation effects on minority carrier diffusion length and defect introduction in homoepitaxial n-GaN

DOE PAGES

Collins, K. C.; Armstrong, Andrew M.; Allerman, Andrew A.; ...

2017-12-21

Here, inherent advantages of wide bandgap materials make GaN-based devices attractive for power electronics and applications in radiation environments. Recent advances in the availability of wafer-scale, bulk GaN substrates have enabled the production of high quality, low defect density GaN devices, but fundamental studies of carrier transport and radiation hardness in such devices are lacking. Here, we report measurements of the hole diffusion length in low threading dislocation density (TDD), homoepitaxial n-GaN, and high TDD heteroepitaxial n-GaN Schottky diodes before and after irradiation with 2.5 MeV protons at fluences of 4–6 × 10 13 protons/cm 2. We also characterize themore » specimens before and after irradiation using electron beam-induced-current (EBIC) imaging, cathodoluminescence, deep level optical spectroscopy (DLOS), steady-state photocapacitance, and lighted capacitance-voltage (LCV) techniques. We observe a substantial reduction in the hole diffusion length following irradiation (50%–55%) and the introduction of electrically active defects which could be attributed to gallium vacancies and associated complexes (V Ga-related), carbon impurities (C-related), and gallium interstitials (Ga i). EBIC imaging suggests long-range migration and clustering of radiation-induced point defects over distances of ~500 nm, which suggests mobile Ga i. Following irradiation, DLOS and LCV reveal the introduction of a prominent optical energy level at 1.9 eV below the conduction band edge, consistent with the introduction of Ga i.« less

Diffusion of dioxygen in 1-alkenes and biphenyl in perfluoro- n-alkanes

NASA Astrophysics Data System (ADS)

Kowert, Bruce A.; Sobush, Kurtis T.; Dang, Nhan C.; Seele, Louis G., III; Fuqua, Chantel F.; Mapes, Courtney L.

2002-02-01

The translational diffusion constant, D, has been measured for O 2 in the even 1-alkenes 1-C 6H 12 to 1-C 16H 32 and biphenyl in n-C 6F 14 and n-C 9F 20. Deviations from the Stokes-Einstein relation were found; the use of D/ T= A/ ηp gave p=0.560±0.017 for O 2 in the 1-alkenes, the same (within experimental error) as found previously for O 2 in the n-alkanes. The charge transfer (CT) transition used to detect O 2 in the 1-alkenes is at 220 nm. The D values for biphenyl in the perfluoro- n-alkanes (PFAs) are consistent with those in the n-alkanes, where p=0.718±0.004. These results suggest that O 2 has similar solute-solvent interactions in both the 1-alkenes and n-alkanes as does biphenyl in the n-alkanes and PFAs.

Diffusion-weighted imaging in the evaluation of odontogenic cysts and tumours.

PubMed

Srinivasan, K; Seith Bhalla, A; Sharma, R; Kumar, A; Roychoudhury, A; Bhutia, O

2012-10-01

The differentiation between keratocystic odontogenic tumour (KCOT) and other cystic/predominantly cystic odontogenic tumours is difficult on conventional CT and MR sequences as there is overlap in the imaging characteristics of these lesions. The purpose of this study was to evaluate the role of diffusion-weighted imaging (DWI) and to assess the performance of apparent diffusion coefficients (ADCs) in the differential diagnosis of odontogenic cysts and tumours. 20 patients with odontogenic cysts and tumours of the maxillomandibular region were examined with DWI. Diffusion-weighted images were obtained with a single-shot echoplanar technique with b-values of 0, 500 and 1000 s mm(-2). An ADC map was obtained at each slice position. The cystic areas of ameloblastoma (n=10) showed free diffusion with a mean ADC value of 2.192±0.33×10(-3) mm(2) s(-1), whereas the solid areas showed restricted diffusion with a mean ADC value of 1.041±0.41×10(-3) mm(2) s(-1). KCOT (n=5) showed restricted diffusion with a mean ADC value of 1.019±0.07×10(-3) mm(2) s(-1). There was a significant difference between the ADC values of KCOT and cystic ameloblastoma (p<0.01, Mann-Whitney U-test). The cut-off with which KCOT and predominantly cystic ameloblastomas were optimally differentiated was 2.013×10(-3) mm(2) s(-1), which yielded 100% sensitivity and 100% specificity. DWI can be used to differentiate KCOT from cystic (or predominantly cystic) odontogenic tumours.

Electron microscopy of AlN-SiC interfaces and solid solutions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bentley, J.; Tanaka, S.; Davis, R.F.

In a 2H AlN-SiC solid solution grown by MBE on {alpha}(6H)-SiC (3{degrees} from [0001]), the epilayer contained a high density of basal faults related to {approximately}5 nm steps on the growth surface: no compositional inhomogeneity was detected by PEELS. In diffusion couples of polycrystalline, sintered AlN on SiC annealed at 1600 and 1700{degrees}C. 8H sialon [nominally (AlN){sub 2}Al{sub 2}O{sub 3}] formed at the interface of SiC and recrystallized epitactic AlN grains, and Si{sub 3}N{sub 4}-rich {beta}{prime} sialon particles formed in the SiC. No interdiffusion was detected by PEELS in diffusion couples of MBE-grown AlN on SiC annealed at 1700 andmore » 1850{degrees}C. Irregular epilayer thickness explains companion Auger depth profile results.« less

Integration of amorphous tantalum silicon nitride (TaSiN) films as diffusion barriers in a Cu/SiLK(TM) metallization scheme

NASA Astrophysics Data System (ADS)

Padiyar, Sumant Devdas

2003-09-01

Current and future performance requirements for high- speed integrated circuit (IC) devices have placed great emphasis on the introduction of novel materials, deposition techniques and improved metrology techniques. The introduction of copper interconnects and more currently low-k dielectric materials in IC fabrication are two such examples. This introduction necessitates research on the compatibility of these materials and process techniques with adjacent diffusion barrier materials. One candidate, which has attracted significant attention is tantalum-silicon-nitride (TaSiN) on account of its superior diffusion barrier performance and high recrystallization temperature1. The subject of this dissertation is an investigation of the integration compatibility and performance of TaSiN barrier layers with a low-k dielectric polymer (SiLK ®2). A plasma- enhanced chemical vapor deposition (PECVD) approach is taken for growth of TaSiN films in this work due to potential advantages in conformal film coverage compared to more conventional physical vapor deposition methods. A Design of Experiment (DOE) methodology was introduced for PECVD of TaSiN on SiLK to optimize film properties such as film composition, resistivity, growth rate and film roughness with respect to the predictors viz. substrate temperature, precursor gas flow and plasma power. The first pass study determined the response window for optimized TaSiN film composition, growth rate and low halide contamination and the compatibility of the process with an organic polymer substrate, i.e. SiLK. Second-pass studies were carried out to deposit ultra- thin (10nm) films on: (a)blanket SiLK to investigate the performance of TaSiN films against copper diffusion, and (b)patterned SiLK to evaluate step coverage and conformality. All TaSiN depositions were carried out on SiO2 substrates for baseline comparisons. A second purpose of the diffusion barrier in IC processing is to improve interfacial adhesion between the barrier and the adjacent dielectric material; especially important for an organic polymer like SiLK. Hence, a detailed study was undertaken to evaluate the interfacial adhesion of TaSiN with SiLK and SiO2 and study the dependence of the adhesion with the film composition. The results of diffusion barrier performance studies, conformality studies, and interfacial adhesion studies of TaSiN films are discussed in relation to the elemental compositions of the films. 1J. S. Reid, M. Nicolet, J. Appl. Phys. 79 (2) p. 1109 (1996). 2SiLK is a low-k dielectric candidate registered by Dow Chemical Company, MI.

Sediment diffusion method improves wastewater nitrogen removal in the receiving lake sediments.

PubMed

Aalto, Sanni L; Saarenheimo, Jatta; Ropponen, Janne; Juntunen, Janne; Rissanen, Antti J; Tiirola, Marja

2018-07-01

Sediment microbes have a great potential to transform reactive N to harmless N 2 , thus decreasing wastewater nitrogen load into aquatic ecosystems. Here, we examined if spatial allocation of the wastewater discharge by a specially constructed sediment diffuser pipe system enhanced the microbial nitrate reduction processes. Full-scale experiments were set on two Finnish lake sites, Keuruu and Petäjävesi, and effects on the nitrate removal processes were studied using the stable isotope pairing technique. All nitrate reduction rates followed nitrate concentrations, being highest at the wastewater-influenced sampling points. Complete denitrification with N 2 as an end-product was the main nitrate reduction process, indicating that the high nitrate and organic matter concentrations of wastewater did not promote nitrous oxide (N 2 O) production (truncated denitrification) or ammonification (dissimilatory nitrate reduction to ammonium; DNRA). Using 3D simulation, we demonstrated that the sediment diffusion method enhanced the contact time and amount of wastewater near the sediment surface especially in spring and in autumn, altering organic matter concentration and oxygen levels, and increasing the denitrification capacity of the sediment. We estimated that natural denitrification potentially removed 3-10% of discharged wastewater nitrate in the 33 ha study area of Keuruu, and the sediment diffusion method increased this areal denitrification capacity on average 45%. Overall, our results indicate that sediment diffusion method can supplement wastewater treatment plant (WWTP) nitrate removal without enhancing alternative harmful processes. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

Accelerated Cartesian expansion (ACE) based framework for the rapid evaluation of diffusion, lossy wave, and Klein-Gordon potentials

DOE PAGES

Baczewski, Andrew David; Vikram, Melapudi; Shanker, Balasubramaniam; ...

2010-08-27

Diffusion, lossy wave, and Klein–Gordon equations find numerous applications in practical problems across a range of diverse disciplines. The temporal dependence of all three Green’s functions are characterized by an infinite tail. This implies that the cost complexity of the spatio-temporal convolutions, associated with evaluating the potentials, scales as O(N s 2N t 2), where N s and N t are the number of spatial and temporal degrees of freedom, respectively. In this paper, we discuss two new methods to rapidly evaluate these spatio-temporal convolutions by exploiting their block-Toeplitz nature within the framework of accelerated Cartesian expansions (ACE). The firstmore » scheme identifies a convolution relation in time amongst ACE harmonics and the fast Fourier transform (FFT) is used for efficient evaluation of these convolutions. The second method exploits the rank deficiency of the ACE translation operators with respect to time and develops a recursive numerical compression scheme for the efficient representation and evaluation of temporal convolutions. It is shown that the cost of both methods scales as O(N sN tlog 2N t). Furthermore, several numerical results are presented for the diffusion equation to validate the accuracy and efficacy of the fast algorithms developed here.« less

1. Context view showing cabin on Lot 2 in foreground ...

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

1. Context view showing cabin on Lot 2 in foreground (17419 North Shore Drive) and east side of Frank-Jensen Summer Home on Lot 3 in background. - Frank-Jensen Summer Home, 17423 North Lake Shore Drive, Telma, Chelan County, WA

Effects of H2O, CO2, and N2 air contaminants on critical airside strain rates for extinction of hydrogen-air counterflow diffusion flames

NASA Technical Reports Server (NTRS)

Pellett, G. L.; Northam, G. B.; Wilson, L. G.; Guerra, Rosemary

1989-01-01

Dish-shaped counterflow diffusion flames centered by opposing laminar jets of H2 and clean and contaminant O2/N2 mixtures in an argon bath at 1 atm were used to study the effects of contaminants on critical airside strain. The jet velocities for both flame extinction and restoration are found for a wide range of contaminant and O2 concentrations in the air jet. The tests are also conducted for a variety of input H2 concentrations. The results are compared with those from several other studies.

Charge Disproportionation in Tetragonal La 2MoO 5 , a Small Band Gap Semiconductor Influenced by Direct Mo–Mo Bonding

DOE PAGES

Colabello, Diane M.; Camino, Fernando E.; Huq, Ashfia; ...

2014-12-31

The structure of the novel compound La 2MoO 5 has been solved from powder X-ray and neutron diffraction data and belongs to the tetragonal space group P4/m (no. 83) with a = 12.6847(3) Å and c = 6.0568(2) Å and with Z = 8. It consists of equal proportions of bioctahedral (Mo 2O 10) and square prismatic (Mo 2O 8) dimers, both of which contain direct Mo-Mo bonds and are arranged in 1D chains. The Mo-Mo bond length in the Mo 2O 10dimers is 2.684(8) Å, while there are two types of Mo 2O 8 dimers with Mo-Mo bonds lengthsmore » of 2.22(2) and 2.28(2) Å. Although the average Mo oxidation state in La 2MoO 5 is 4+, the very different Mo-Mo distances reflect the fact that the Mo 2O 10 dimers contain only Mo5+ (d(1)), while the prismatic Mo2O8 dimers only contain Mo 3+ (d 3), a result directly confirmed by density function theory calculations. This is due to the complete disproportionation of Mo 4+, a phenomenon which has not previously been observed in solid-state compounds. La 2MoO 5 is diamagnetic, behavior which is not expected for a nonmetallic transition-metal oxide whose cation sites have an odd number of d-electrons. The resistivity displays the Arrhenius-type activated behavior expected for a semiconductor with a band gap of 0.5 eV, exhibiting an unusually small transport gap relative to other diamagnetic oxides. Diffuse reflectance studies indicate that La 2MoO 5 is a rare example of a stable oxide semiconductor with strong infrared absorbance. Lastly, we show that the d-orbital splitting associated with the Mo 2O 8 and Mo 2O 10 dimeric units can be rationalized using simple molecular orbital bonding concepts.« less

Fast parallel algorithms that compute transitive closure of a fuzzy relation

NASA Technical Reports Server (NTRS)

Kreinovich, Vladik YA.

1993-01-01

The notion of a transitive closure of a fuzzy relation is very useful for clustering in pattern recognition, for fuzzy databases, etc. The original algorithm proposed by L. Zadeh (1971) requires the computation time O(n(sup 4)), where n is the number of elements in the relation. In 1974, J. C. Dunn proposed a O(n(sup 2)) algorithm. Since we must compute n(n-1)/2 different values s(a, b) (a not equal to b) that represent the fuzzy relation, and we need at least one computational step to compute each of these values, we cannot compute all of them in less than O(n(sup 2)) steps. So, Dunn's algorithm is in this sense optimal. For small n, it is ok. However, for big n (e.g., for big databases), it is still a lot, so it would be desirable to decrease the computation time (this problem was formulated by J. Bezdek). Since this decrease cannot be done on a sequential computer, the only way to do it is to use a computer with several processors working in parallel. We show that on a parallel computer, transitive closure can be computed in time O((log(sub 2)(n))2).

Transscleral diffusion of ethacrynic acid and sodium fluorescein

PubMed Central

Lin, Cheng-Wen; Wang, Yong; Challa, Pratap; Epstein, David L.

2007-01-01

Purpose One of the current limitations in developing novel glaucoma drugs that target the trabecular meshwork (TM) is the induced corneal toxicity from eyedrop formulations. To avoid the corneal toxicity, an alternative approach would be to deliver TM drugs through the sclera. To this end, we quantified ex vivo diffusion coefficient of a potential TM drug, ethacrynic acid (ECA), and investigated mechanisms of ECA transport in the sclera. Methods An Ussing-type diffusion apparatus was built to measure the apparent diffusion coefficient of ECA in fresh porcine sclera at 4 °C. To understand mechanisms of ECA transport, we quantified the transscleral transport of a fluorescent tracer, sodium fluorescein (NaF), that has a similar molecular weight but is more hydrophilic compared to ECA. Furthermore, we developed a mathematical model to simulate the transport processes and used it to analyze the experimental data. The model was also used to investigate the dependence of diffusion coefficients on volume fraction of viable cells and the binding of NaF and ECA to scleral tissues. Results The diffusion coefficients of ECA and NaF in the sclera were 48.5±15.1x10-7 cm2/s (n=9) and 5.23±1.93x10-7 cm2/s (n=8), respectively. Both diffusion coefficients were insensitive to cell shrinkage caused by ECA during the diffusion experiments and cell damage caused by the storage of tissues ex vivo before the experiments. Binding of ECA to scleral tissues could not be detected. The apparent maximum binding capacity and the apparent equilibrium dissociation constant for NaF were 80±5 mM and 2.5±0.5 mM (n=3), respectively. Conclusions These data demonstrated that ECA diffusion was minimally hindered by structures in the sclera, presumably due to the lack of cells and binding sites for ECA in the sclera. PMID:17356511

Probabilistic and statistical relationships between number of vehicles and number of visitors at a geologic site in a National Park

USGS Publications Warehouse

Crovelli, R.A.

1997-01-01

The National Park Service needs to establish in all of the national parks how large the parking lots should be in order to enjoy and presence our natural resources, for example, in the Delicate Arch in the Arches National Park. Probabilistic and statistical relationships were developed between the number of vehicles (N) at one time in the Wolfe Ranch parking lot and the number of visitors (X) at Delicate Arch 1.5 miles away in the Arches National Park, southeastern Utah. The value of N is determined such that 30 or more visitors are at the arch only 10% of the time.

First passage times and asymmetry of DNA translocation

NASA Astrophysics Data System (ADS)

Lua, Rhonald C.; Grosberg, Alexander Y.

2005-12-01

Motivated by experiments in which single-stranded DNA with a short hairpin loop at one end undergoes unforced diffusion through a narrow pore, we study the first passage times for a particle, executing one-dimensional Brownian motion in an asymmetric sawtooth potential, to exit one of the boundaries. We consider the first passage times for the case of classical diffusion, characterized by a mean-square displacement of the form ⟨(Δx)2⟩˜t , and for the case of anomalous diffusion or subdiffusion, characterized by a mean-square displacement of the form ⟨(Δx)2⟩˜tγ with 0<γ<1 . In the context of classical diffusion, we obtain an expression for the mean first passage time and show that this quantity changes when the direction of the sawtooth is reversed or, equivalently, when the reflecting and absorbing boundaries are exchanged. We discuss at which numbers of “teeth” N (or number of DNA nucleotides) and at which heights of the sawtooth potential this difference becomes significant. For large N , it is well known that the mean first passage time scales as N2 . In the context of subdiffusion, the mean first passage time does not exist. Therefore, we obtain instead the distribution of first passage times in the limit of long times. We show that the prefactor in the power relation for this distribution is simply the expression for the mean first passage time in classical diffusion. We also describe a hypothetical experiment to calculate the average of the first passage times for a fraction of passage events that each end within some time t* . We show that this average first passage time scales as N2/γ in subdiffusion.

Dielectrophoresis enhances the whitening effect of carbamide peroxide on enamel.

PubMed

Ivanoff, Chris S; Hottel, Timothy L; Garcia-Godoy, Franklin; Riga, Alan T

2011-10-01

To compare the enamel whitening effect of a 20-minute dielectrophoresis enhanced electrochemical delivery to a 20-minute diffusion treatment. Forty freshly extracted human teeth without detectable caries or restoration were stored in distilled water at 4 degrees C and used within 1 month of extraction. Two different bleaching gels (Plus White 5 Minute Speed Whitening Gel and 35% Opalescence PF gel) were tested. The study had two parts: Part 1--Quantitative comparison of hydrogen peroxide (H2O2, HP) absorption--following application of an over-the-counter 35% HP whitening gel (Plus White 5 Minute Speed Whitening Gel) to 30 (n = 30) extracted human teeth by conventional diffusion or dielectrophoresis. The amount of H2O2 that diffused from the dentin was measured by a colorimetric oxidation-reduction reaction kit. HP concentration was measured by UV-Vis spectroscopy at 550 nm. Part 2--HP diffusion in stained teeth--35% carbamide peroxide whitening gel (35% Opalescence PF gel) was applied to 10 extracted human teeth (n = 10) stained by immersion in a black tea solution for 48 hours. The teeth were randomly assigned to the 20-minute dielectrophoresis or diffusion treatment group; whitening was evaluated by a dental spectrophotometer and macro-photography. Part 1: The analysis found significant differences between both groups with relative percent errors of 3% or less (a single outlier had an RPE of 12%). The average absorbance for the dielectrophoresis group in round 1 was 79% greater than the diffusion group. The average absorbance for the dielectrophoresis group in round 2 was 130% greater than the diffusion group. A single-factor ANOVA found a statistically significant difference between the diffusion and dielectrophoresis groups (P = 0.01). Part 2--The average change in Shade Guide Units (SGU) was 0.6 for the diffusion group, well under the error of measurement of 0.82 SGU. The average change in SGU for the dielectrophoresis group was 9, significantly above the error of measurement and 14 times or 1,400% greater than the diffusion group average. A single-factor ANOVA found a statistically significant difference between the diffusion and dielectrophoresis treatment groups (P < 0.001).

Short-term variations of diffuse CO2 emission from the summit crater of Teide volcano, Tenerife, Canary Islands

NASA Astrophysics Data System (ADS)

Melián, Gladys V.; Ocampo, Stephany; Nisbet, Andrew; McKnight, Samara; Monzón, Tania; Asensio-Ramos, María; Alonso, Mar; Rodríguez, Fátima; García-Merino, Marta; Amonte, Cecilia; Pérez, Nemesio M.

2017-04-01

Teide volcano in Tenerife, Canary Islands, is characterized by the presence of a weak fumarolic system, steamy ground, and high rates of diffuse CO2 degassing all around this area. The temperature of the fumaroles (83˚ C) corresponds to the boiling point of water at discharge conditions. Previous diffuse CO2 surveys have shown to be an important tool to detect early warnings of possible impending volcanic unrests at Tenerife Island (Melián et al., 2012; Pérez et al., 2013). During June, July and August 2016, twelve soil gas surveys were performed at the summit crater of Teide volcano in order to evaluate short-term variations of diffuse CO2 degassing pattern. Soil CO2 efflux and soil temperature were always measured at the same 38 observation sites homogeneously distributed within an area of about 6,972 m2 inside the summit crater. Soil CO2 diffuse effluxes were estimated according to the accumulation chamber method and using a non-dispersive infrared (NDIR) LICOR-820 CO2analyzer. Soil CO2 efflux values presented a range from non-detectable (˜0.5 gṡm-2ṡd-1) to 10.8 kgṡm-2ṡd-1, with an average value of 2.7 kgṡm-2ṡd-1, while soil temperature ranged from 13.1 to 83.6˚ C with a mean value of 55.6˚ C. Sequential Gaussian simulations (sGs) were used for mapping and estimate the volcanic diffuse CO2 emission at each survey. The highest values of diffuse CO2 efflux were measured along the east (>8 kgṡm-2ṡd-1) and west (>5 kgṡm-2ṡd-1) sectors of the crater. Areas with highest diffuse CO2 effluxes were also characterized by a relatively high soil temperature (>60˚ C) and by an intense hydrothermal alteration. Weekly diffuse CO2 emission variations from the summit crater during the study period showed a range between 13.5 and 24.7 tṡd-1 with an average value of 18.9 tṡd-1. During these 3 months, the seismic activity rate was about 10 seismic events per month registered by the Instituto Geográfico Nacional (IGN; http://www.ign.es). We compared these observed weekly variations with monthly variations of a longer period with similar seismic rate such as 2014 (about 8 seismic events per month, and values ranged from 15.6 to 22.4 tṡd-1, and an average value of 19.0 tṡd-1. These values are in the same order than the observed during our study. However, for a longer period of observation, from 1999 to 2010, diffuse CO2 emission rates varied from 2.2 to 36.3 tṡd-1, with a mean value of 15.7 tṡd-1 (Melián et al., 2012). The long-term variations observed in the diffuse CO2 emission rates during this period of 10 years were significantly higher than short-term variations observed in the period of study. It is also important to note that the volcanic-seismic crisis of 2004 occurred with an increase on the CO2 emission from Teide summit crater (Melián et al., 2012). This study shows that during periods of seismic tranquility, diffuse CO2 emission rates will not suffer significant variations, whether performed on a weekly or monthly basis. References: Melián et al., 2012. Bull. Volcanol. DOI 10.1007/s00445-012-0613-1 Pérez et al., 2013. J. Geol. Soc. DOI 10.1144/jgs2012-125 .

Comparison between Disk Diffusion and Microdilution Methods for Determining Susceptibility of Clinical Fungal Isolates to Caspofungin▿

PubMed Central

Milici, Maria Eleonora; Maida, Carmelo Massimo; Spreghini, Elisabetta; Ravazzolo, Barbara; Oliveri, Salvatore; Scalise, Giorgio; Barchiesi, Francesco

2007-01-01

We compared the caspofungin (CAS) susceptibility testing results generated by the disk diffusion (DD) assay with the results of the Clinical and Laboratory Standards Institute (CLSI) broth microdilution (BD) reference method for 106 yeast isolates. The isolates represented 11 different fungal species, including Candida albicans (n = 50), C. parapsilosis (n = 10), C. glabrata (n = 10), C. tropicalis (n = 10), C. guillermondii (n = 6), C. rugosa (n = 5), C. krusei (n = 5), C. kefyr (n = 2), C. pelliculosa (n = 2), Saccharomyces cerevisiae (n = 3), and Geotrichum candidum (n = 3). The DD assay was performed in supplemented Mueller-Hinton agar with CAS, which was tested at concentrations of 2, 10, and 25 μg per disk. MICs and inhibition zone diameters were evaluated at 24 and 48 h. In general, the results obtained by the DD assay correlated well with those obtained by the BD method. In particular, a significant correlation between methods was observed when CAS was used at concentration of 2 μg/disk at a reading time of either 24 or 48 h. PMID:17728477

Contribution by Macroalgal Mats to Primary Production of a Shallow Embayment Under High and Low Nitrogen-loading Rates

NASA Astrophysics Data System (ADS)

Peckol, P.; Rivers, J. S.

1996-09-01

The limits on primary production in areas undergoing eutrophication may be set by indirect effects of nitrogen loading, i.e. decreasing irradiances, associated with proliferating opportunistic algae. Using in situphoton flux density (PFD) availability estimates within unattached algal mats and photosynthetic parameters determined from photosynthesis vs.irradiance (P vs.I) curves generated for the dominant components of mat assemblages, Cladophora vagabundaand Gracilaria tikvahiae, seasonal net mat production rate for estuaries (Waquoit Bay, Massachusetts, U.S.A.) receiving high (Childs River) and low (Sage Lot Pond) N-loading rates were determined. Although abundance of C. vagabundawas 2× greater than G. tikvahiae, the former species contributed only about 50% of total mat productivity, due largely to rapid light attenuation within the dense algal mat. While mat production was low and similar at both sides during winter (≈0·35 g C m -2 day -1), for other seasons, the net mat daytime productivity at Childs River, the N-loaded site, was 2·5× higher than rates determined for Sage Lot Pond. Although annual net daytime production at Childs River (1094 g C m -2 year -1) was comparable to estimates for other algal mat assemblages in eutrophic systems, primary production of the Waquoit Bay system was found to become self-limiting as available PFD controls maximum productivity. In photosynthetically inactive portions of the algal mat, carbon release was estimated from tissue-loss measurements at 0·14 g C m -2 day -1for C. vagabundaand 0·05 g C m -2 day -1for G. tikvahiae. Annual in situC release of 73 g C m -2is ≈20% of annual net mat production (fixed carbon not respired by algae) in this embayment. Although both estuaries showed net autotrophy year round (Pg:R>1), the high metabolic cost of a large, inactive mat resulted in lower Pg:R ratios at Childs Rivers than at Sage Lot Pond, particularly during the summer period of peak production. Thus, it is predicted that the Waquoit Bay system will experience an overall decline in Pg:R ratios and consequent increase in anoxic events as eutrophication continues.

The role of the Ti and Mo barrier layer in Ti/Al metallization to AlGaN/GaN heterostructures at identical process conditions: a structural and chemical characterization

NASA Astrophysics Data System (ADS)

Chandran, Narendraraj; Kolakieva, Lilyana; Kakanakov, Roumen; Polychroniadis, E. K.

2015-11-01

The composition and structure of TiAl-based metallizations have been investigated depending on the Ti and Mo barriers. The lowest contact resistivity of 4 × 10-6 Ω.cm2 for a Ti barrier and 7 × 10-6 Ω.cm2 for a Mo barrier is obtained at a Ti/Al ratio of 0.43 after annealing at 800 °C. The scanning transmission electron microscope (STEM) and energy dispersive spectroscopy (EDS) analyses reveal that Mo is not an effective barrier for the Au in-diffusion and Al out of diffusion during annealing. The intensive diffusion processes lead to the formation of the semimetal TiN compound at the interface and intermetallic phases of Au, Al, and Ti, the structure and composition of which depend on the barrier metal.

Aerodynamic Characteristics of the Close-Coupled Canard as Applied to Low-to-Moderate Swept Wings. Volume 2. Subsonic Speed Regime

DTIC Science & Technology

1979-01-01

I I I I , UNCLASSIFIED SIECURITV CloWF7ICATIOp4 Of’ THIS PAOE (When Date Entered) R ’ PORT DOCUMENTATION PAGE BEFORE COMPLETING FORM r ~ HNSr-c9/21 2...FASE: DISTRIBUTION TdNLIMITED 17. 01ST R IHaU TI1N 17 A T fM E T h~ I I . sh~e f(. nt 14* 4411 1 ft¶ ork " 2t’. Nit~Sllernt ttarn~pnpetl 16...Iw lot-tn-Iri, Rat jun Vxi llloin wl ii C(’anmrd l) (,- l eci t lnm . . r . . . . i . n. . . t . . . . . .. . 7 2 A 0 - ý1t 1. 1mliu Drop Vitr io l

Optimizing Search Patterns for Multiple Searchers Prosecuting a Single Contact In the South China Sea

DTIC Science & Technology

2016-09-01

searching for lost car keys in a parking lot to prosecuting a submarine in the South China Sea. This research draws on oceanographic properties to...search area based on the oceanographic properties at 21N 119E. 14. SUBJECT TERMS Search Theory, Undersea Warfare, South China Sea, Anti- Submarine ...lot to prosecuting a submarine in the South China Sea. This research draws on oceanographic properties to develop a search radii for two surface ships

Performance and emissions of an engine fuelled by biogas of palm oil mill effluent

NASA Astrophysics Data System (ADS)

Arjuna, J.; Sitorus, T. B.; Ambarita, H.; Abda, S.

2018-02-01

This research investigates the performance and emissions of an engine by biogas and gasoline. The experiments use biogas of palm oil mill effluent (POME) with turbocharger at engine loading conditions (100, 200, 300, 400, and 500 Watt). Specific fuel consumption and thermal efficiency are used to compare engine performance, and emission analysis is based on parameters such as carbon monoxide (CO), hydrocarbon (HC), carbon dioxide (CO2) and oxide (O2). The experimental data show that the maximum thermal efficiency when engine use biogas and gasoline is 20.44% and 22.22% respectively. However, there was CO emission reduction significantly when the engine using POME biogas.

Molecular dynamics simulation of the ionic liquid N-ethyl-N,N-dimethyl-N-(2-methoxyethyl)ammonium bis(trifluoromethanesulfonyl)imide.

PubMed

Siqueira, Leonardo J A; Ribeiro, Mauro C C

2007-10-11

Thermodynamics, structure, and dynamics of an ionic liquid based on a quaternary ammonium salt with ether side chain, namely, N-ethyl-N,N-dimethyl-N-(2-methoxyethyl)ammonium bis(trifluoromethanesulfonyl)imide, MOENM2E TFSI, are investigated by molecular dynamics (MD) simulations. Average density and configurational energy of simulated MOENM2E TFSI are interpreted with models that take into account empirical ionic volumes. A throughout comparison of the equilibrium structure of MOENM2E TFSI with previous results for the more common ionic liquids based on imidazolium cations is provided. Several time correlation functions are used to reveal the microscopic dynamics of MOENM2E TFSI. Structural relaxation is discussed by the calculation of simultaneous space-time correlation functions. Temperature effects on transport coefficients (diffusion, conductivity, and viscosity) are investigated. The ratio between the actual conductivity and the estimate from ionic diffusion by the Nernst-Einstein equation indicates that correlated motion of neighboring ions in MOENM2E TFSI is similar to imidazolium ionic liquids. In line with experiment, Walden plot of conductivity and viscosity indicates that simulated MOENM2E TFSI should be classified as a poor ionic liquid.

First-principles study of transition-metal nitrides as diffusion barriers against Al

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mei, Zhi-Gang; Yacout, Abdellatif M.; Kim, Yeon Soo

2016-04-01

Using density-functional theory based first-principles calculations we provided a comparative study of the diffusion barrier properties of TiN, ZrN, and HfN against Al for U-Mo dispersion fuel applications. We firstly examined the thermodynamic stability of these transition-metal nitrides with Al. The calculated heats of reaction show that both TiN and ZrN are thermodynamically unstable diffusion barrier materials, which might be decomposed by Al at relatively high temperatures. As a comparison, HfN is a stable diffusion barrier material for Al. To evaluate the kinetic stability of these nitride systems against Al diffusion, we investigated the diffusion mechanisms of Al in TiN,more » ZrN and HfN using atomic scale simulations. The effect of non-stoichiometry on the defect formation and Al migration was systematically studied. (C) 2015 ELSEVIER B.V. All rights reserved« less

Molecular dynamics simulations of diffusion and clustering along critical isotherms of medium-chain n-alkanes.

PubMed

Mutoru, J W; Smith, W; O'Hern, C S; Firoozabadi, A

2013-01-14

Understanding the transport properties of molecular fluids in the critical region is important for a number of industrial and natural systems. In the literature, there are conflicting reports on the behavior of the self diffusion coefficient D(s) in the critical region of single-component molecular systems. For example, D(s) could decrease to zero, reach a maximum, or remain unchanged and finite at the critical point. Moreover, there is no molecular-scale understanding of the behavior of diffusion coefficients in molecular fluids in the critical regime. We perform extensive molecular dynamics simulations in the critical region of single-component fluids composed of medium-chain n-alkanes-n-pentane, n-decane, and n-dodecane-that interact via anisotropic united-atom potentials. For each system, we calculate D(s), and average molecular cluster sizes κ(cl) and numbers N(cl) at various cluster lifetimes τ, as a function of density ρ in the range 0.2ρ(c) ≤ ρ ≤ 2.0ρ(c) at the critical temperature T(c). We find that D(s) decreases with increasing ρ but remains finite at the critical point. Moreover, for any given τ < 1.2 × 10(-12) s, κ(cl) increases with increasing ρ but is also finite at the critical point.

Understanding Nitrifier Denitrification: How far are we?

NASA Astrophysics Data System (ADS)

Wrage-Mönnig, N.

2014-12-01

Nitrifier denitrification is the oxidation of ammonia (NH3) via hydroxylamine (NH2OH) to nitrite (NO2-) and subsequent reduction of NO2- via nitric oxide (NO) to the greenhouse gas nitrous oxide (N2O) and possibly to dinitrogen (N2) by autotrophic nitrifiers. Especially in recent years, a lot of research has been conducted on this pathway. Under some conditions, it might dominate the N2O production from soils. Methods for studying nitrifier denitrification include selective inhibition, stable isotope and isotopomer methods, molecular and modelling approaches. They are applied from pure culture and pot studies to the field scale, trying to improve our knowledge of the conditions and factors controlling nitrifier denitrification. But how far are we? What have we learned so far and what remains to be discovered? With this contribution, I am trying to give an update of our understanding of this less well-known but important pathway.

Assumptions of acceptance sampling and the implications for lot contamination: Escherichia coli O157 in lots of Australian manufacturing beef.

PubMed

Kiermeier, Andreas; Mellor, Glen; Barlow, Robert; Jenson, Ian

2011-04-01

The aims of this work were to determine the distribution and concentration of Escherichia coli O157 in lots of beef destined for grinding (manufacturing beef) that failed to meet Australian requirements for export, to use these data to better understand the performance of sampling plans based on the binomial distribution, and to consider alternative approaches for evaluating sampling plans. For each of five lots from which E. coli O157 had been detected, 900 samples from the external carcass surface were tested. E. coli O157 was not detected in three lots, whereas in two lots E. coli O157 was detected in 2 and 74 samples. For lots in which E. coli O157 was not detected in the present study, the E. coli O157 level was estimated to be <12 cells per 27.2-kg carton. For the most contaminated carton, the total number of E. coli O157 cells was estimated to be 813. In the two lots in which E. coli O157 was detected, the pathogen was detected in 1 of 12 and 2 of 12 cartons. The use of acceptance sampling plans based on a binomial distribution can provide a falsely optimistic view of the value of sampling as a control measure when applied to assessment of E. coli O157 contamination in manufacturing beef. Alternative approaches to understanding sampling plans, which do not assume homogeneous contamination throughout the lot, appear more realistic. These results indicate that despite the application of stringent sampling plans, sampling and testing approaches are inefficient for controlling microbiological quality.

7 CFR 27.12 - Classification request for each lot of cotton.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 2 2014-01-01 2014-01-01 false Classification request for each lot of cotton. 27.12... CONTAINER REGULATIONS COTTON CLASSIFICATION UNDER COTTON FUTURES LEGISLATION Regulations Classification Requests § 27.12 Classification request for each lot of cotton. For each lot or mark of cotton of which the...

7 CFR 27.12 - Classification request for each lot of cotton.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 2 2010-01-01 2010-01-01 false Classification request for each lot of cotton. 27.12... CONTAINER REGULATIONS COTTON CLASSIFICATION UNDER COTTON FUTURES LEGISLATION Regulations Classification Requests § 27.12 Classification request for each lot of cotton. For each lot or mark of cotton of which the...

7 CFR 27.12 - Classification request for each lot of cotton.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 7 Agriculture 2 2013-01-01 2013-01-01 false Classification request for each lot of cotton. 27.12... CONTAINER REGULATIONS COTTON CLASSIFICATION UNDER COTTON FUTURES LEGISLATION Regulations Classification Requests § 27.12 Classification request for each lot of cotton. For each lot or mark of cotton of which the...

7 CFR 27.12 - Classification request for each lot of cotton.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 2 2011-01-01 2011-01-01 false Classification request for each lot of cotton. 27.12... CONTAINER REGULATIONS COTTON CLASSIFICATION UNDER COTTON FUTURES LEGISLATION Regulations Classification Requests § 27.12 Classification request for each lot of cotton. For each lot or mark of cotton of which the...

7 CFR 27.12 - Classification request for each lot of cotton.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 7 Agriculture 2 2012-01-01 2012-01-01 false Classification request for each lot of cotton. 27.12... CONTAINER REGULATIONS COTTON CLASSIFICATION UNDER COTTON FUTURES LEGISLATION Regulations Classification Requests § 27.12 Classification request for each lot of cotton. For each lot or mark of cotton of which the...

Methods To Determine the Silicone Oil Layer Thickness in Sprayed-On Siliconized Syringes.

PubMed

Loosli, Viviane; Germershaus, Oliver; Steinberg, Henrik; Dreher, Sascha; Grauschopf, Ulla; Funke, Stefanie

2018-01-01

The silicone lubricant layer in prefilled syringes has been investigated with regards to siliconization process performance, prefilled syringe functionality, and drug product attributes, such as subvisible particle levels, in several studies in the past. However, adequate methods to characterize the silicone oil layer thickness and distribution are limited, and systematic evaluation is missing. In this study, white light interferometry was evaluated to close this gap in method understanding. White light interferometry demonstrated a good accuracy of 93-99% for MgF 2 coated, curved standards covering a thickness range of 115-473 nm. Thickness measurements for sprayed-on siliconized prefilled syringes with different representative silicone oil distribution patterns (homogeneous, pronounced siliconization at flange or needle side, respectively) showed high instrument (0.5%) and analyst precision (4.1%). Different white light interferometry instrument parameters (autofocus, protective shield, syringe barrel dimensions input, type of non-siliconized syringe used as base reference) had no significant impact on the measured average layer thickness. The obtained values from white light interferometry applying a fully developed method (12 radial lines, 50 mm measurement distance, 50 measurements points) were in agreement with orthogonal results from combined white and laser interferometry and 3D-laser scanning microscopy. The investigated syringe batches (lot A and B) exhibited comparable longitudinal silicone oil layer thicknesses ranging from 170-190 nm to 90-100 nm from flange to tip and homogeneously distributed silicone layers over the syringe barrel circumference (110- 135 nm). Empty break-loose (4-4.5 N) and gliding forces (2-2.5 N) were comparably low for both analyzed syringe lots. A silicone oil layer thickness of 100-200 nm was thus sufficient for adequate functionality in this particular study. Filling the syringe with a surrogate solution including short-term exposure and emptying did not significantly influence the silicone oil layer at the investigated silicone level. It thus appears reasonable to use this approach to characterize silicone oil layers in filled syringes over time. The developed method characterizes non-destructively the layer thickness and distribution of silicone oil in empty syringes and provides fast access to reliable results. The gained information can be further used to support optimization of siliconization processes and increase the understanding of syringe functionality. LAY ABSTRACT: Silicone oil layers as lubricant are required to ensure functionality of prefilled syringes. Methods evaluating these layers are limited, and systematic evaluation is missing. The aim of this study was to develop and assess white light interferometry as an analytical method to characterize sprayed-on silicone oil layers in 1 mL prefilled syringes. White light interferometry showed a good accuracy (93-99%) as well as instrument and analyst precision (0.5% and 4.1%, respectively). Different applied instrument parameters had no significant impact on the measured layer thickness. The obtained values from white light interferometry applying a fully developed method concurred with orthogonal results from 3D-laser scanning microscopy and combined white light and laser interferometry. The average layer thicknesses in two investigated syringe lots gradually decreased from 170-190 nm at the flange to 100-90 nm at the needle side. The silicone layers were homogeneously distributed over the syringe barrel circumference (110-135 nm) for both lots. Empty break-loose (4-4.5 N) and gliding forces (2-2.5 N) were comparably low for both analyzed syringe lots. Syringe filling with a surrogate solution, including short-term exposure and emptying, did not significantly affect the silicone oil layer. The developed, non-destructive method provided reliable results to characterize the silicone oil layer thickness and distribution in empty siliconized syringes. This information can be further used to support optimization of siliconization processes and increase understanding of syringe functionality. © PDA, Inc. 2018.

46 CFR 160.047-5 - Inspections and tests. 1

Code of Federal Regulations, 2013 CFR

2013-10-01

...: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Specification for a Buoyant Vest, Kapok or Fibrous Glass, Adult... labeled buoyant vests shall— (1) Maintain quality control of the materials used, the manufacturing methods.... (b) Lot size and sampling. (1) A lot consists of 500 buoyant vests or fewer. (2) A new lot begins...

46 CFR 160.047-5 - Inspections and tests. 1

Code of Federal Regulations, 2014 CFR

2014-10-01

...: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Specification for a Buoyant Vest, Kapok or Fibrous Glass, Adult... labeled buoyant vests shall— (1) Maintain quality control of the materials used, the manufacturing methods.... (b) Lot size and sampling. (1) A lot consists of 500 buoyant vests or fewer. (2) A new lot begins...

46 CFR 160.047-5 - Inspections and tests. 1

Code of Federal Regulations, 2012 CFR

2012-10-01

...: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Specification for a Buoyant Vest, Kapok or Fibrous Glass, Adult... labeled buoyant vests shall— (1) Maintain quality control of the materials used, the manufacturing methods.... (b) Lot size and sampling. (1) A lot consists of 500 buoyant vests or fewer. (2) A new lot begins...

Biexponential characterization of prostate tissue water diffusion decay curves over an extended b-factor range.

PubMed

Mulkern, Robert V; Barnes, Agnieszka Szot; Haker, Steven J; Hung, Yin P; Rybicki, Frank J; Maier, Stephan E; Tempany, Clare M C

2006-06-01

Detailed measurements of water diffusion within the prostate over an extended b-factor range were performed to assess whether the standard assumption of monoexponential signal decay is appropriate in this organ. From nine men undergoing prostate MR staging examinations at 1.5 T, a single 10-mm-thick axial slice was scanned with a line scan diffusion imaging sequence in which 14 equally spaced b factors from 5 to 3,500 s/mm(2) were sampled along three orthogonal diffusion sensitization directions in 6 min. Due to the combination of long scan time and limited volume coverage associated with the multi-b-factor, multidirectional sampling, the slice was chosen online from the available T2-weighted axial images with the specific goal of enabling the sampling of presumed noncancerous regions of interest (ROIs) within the central gland (CG) and peripheral zone (PZ). Histology from prescan biopsy (n=9) and postsurgical resection (n=4) was subsequently employed to help confirm that the ROIs sampled were noncancerous. The CG ROIs were characterized from the T2-weighted images as primarily mixtures of glandular and stromal benign prostatic hyperplasia, which is prevalent in this population. The water signal decays with b factor from all ROIs were clearly non-monoexponential and better served with bi- vs. monoexponential fits, as tested using chi(2)-based F test analyses. Fits to biexponential decay functions yielded intersubject fast diffusion component fractions in the order of 0.73+/-0.08 for both CG and PZ ROIs, fast diffusion coefficients of 2.68+/-0.39 and 2.52+/-0.38 microm(2)/ms and slow diffusion coefficients of 0.44+/-0.16 and 0.23+/-0.16 um(2)/ms for CG and PZ ROIs, respectively. The difference between the slow diffusion coefficients within CG and PZ was statistically significant as assessed with a Mann-Whitney nonparametric test (P<.05). We conclude that a monoexponential model for water diffusion decay in prostate tissue is inadequate when a large range of b factors is sampled and that biexponential analyses are better suited for characterizing prostate diffusion decay curves.

76 FR 57041 - Kobe Brown and Gregory W. Pearson, dba DERMAPPS; Analysis of Proposed Consent Order To Aid Public...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-09-15

... received on or before October 10, 2011. ADDRESSES: Interested parties may file a comment online or on paper... section below. Write ``DERMAPPS, File No. 102 3205'' on your comment, and file your comment online at... in person or by calling (202) 326-2222. You can file a comment online or on paper. For the Commission...

Nitric oxide kinetics in the afterglow of a diffuse plasma filament

NASA Astrophysics Data System (ADS)

Burnette, D.; Montello, A.; Adamovich, I. V.; Lempert, W. R.

2014-08-01

A suite of laser diagnostics is used to study kinetics of vibrational energy transfer and plasma chemical reactions in a nanosecond pulse, diffuse filament electric discharge and afterglow in N2 and dry air at 100 Torr. Laser-induced fluorescence of NO and two-photon absorption laser-induced fluorescence of O and N atoms are used to measure absolute, time-resolved number densities of these species after the discharge pulse, and picosecond coherent anti-Stokes Raman spectroscopy is used to measure time-resolved rotational temperature and ground electronic state N2(v = 0-4) vibrational level populations. The plasma filament diameter, determined from plasma emission and NO planar laser-induced fluorescence images, remains nearly constant after the discharge pulse, over a few hundred microseconds, and does not exhibit expansion on microsecond time scale. Peak temperature in the discharge and the afterglow is low, T ≈ 370 K, in spite of significant vibrational nonequilibrium, with peak N2 vibrational temperature of Tv ≈ 2000 K. Significant vibrational temperature rise in the afterglow is likely caused by the downward N2-N2 vibration-vibration (V-V) energy transfer. Simple kinetic modeling of time-resolved N, O, and NO number densities in the afterglow, on the time scale longer compared to relaxation and quenching time of excited species generated in the plasma, is in good agreement with the data. In nitrogen, the N atom density after the discharge pulse is controlled by three-body recombination and radial diffusion. In air, N, NO and O concentrations are dominated by the reverse Zel'dovich reaction, N + NO → N2 + O, and ozone formation reaction, O + O2 + M → O3 + M, respectively. The effect of vibrationally excited nitrogen molecules and excited N atoms on NO formation kinetics is estimated to be negligible. The results suggest that NO formation in the nanosecond pulse discharge is dominated by reactions of excited electronic states of nitrogen, occurring on microsecond time scale.

Gas mixture for diffuse-discharge switch

DOEpatents

Christophorou, Loucas G.; Carter, James G.; Hunter, Scott R.

1984-01-01

Gaseous medium in a diffuse-discharge switch of a high-energy pulse generator is formed of argon combined with a compound selected from the group consisting of CF.sub.4, C.sub.2 F.sub.6, C.sub.3 F.sub.8, n-C.sub.4 F.sub.10, WF.sub.6, (CF.sub.3).sub.2 S and (CF.sub.3).sub.2 O.

Gas mixture for diffuse-discharge switch

DOEpatents

Christophorou, L.G.; Carter, J.G.; Hunter, S.R.

1982-08-31

Gaseous medium in a diffuse-discharge switch of a high-energy pulse generator is formed of argon combined with a compound selected from the group consisting of CF/sub 4/, C/sub 2/F/sub 6/, C/sub 3/F/sub 8/, n-C/sub 4/F/sub 10/, WF/sub 6/, (CF/sub 3/)/sub 2/S and (CF/sub 3/)/sub 2/O.

Determination of molecular diffusion coefficient in n-alkane binary mixtures: empirical correlations.

PubMed

De Mezquia, D Alonso; Bou-Ali, M Mounir; Larrañaga, M; Madariaga, J A; Santamaría, C

2012-03-08

In this work we have measured the molecular diffusion coefficient of the n-alkane binary series nC(i)-nC(6), nC(i)-nC(10), and nC(i)-nC(12) at 298 K and 1 atm and a mass fraction of 0.5 by using the so-called sliding symmetric tubes technique. The results show that the diffusion coefficient at this concentration is proportional to the inverse viscosity of the mixture. In addition, we have also measured the diffusion coefficient of the systems nC(12)-nC(6), nC(12)-nC(7), and nC(12)-nC(8) as a function of concentration. From the data obtained, it is shown that the diffusion coefficient of the n-alkane binary mixtures at any concentration can be calculated from the molecular weight of the components and the dynamic viscosity of the corresponding mixture at 50% mass fraction.

Low oxygen treatment prior to cold storage decreases the incidence of bitter pit in 'Golden Reinders' apples.

PubMed

Val, Jesús; Fernández, Victoria; López, Paola; Peiró, Jose María; Blanco, Alvaro

2010-02-01

The effect of subjecting 'Golden Reinders' apples to a low O(2) pre-treatment (LOT; 1-2% O(2)) was evaluated as a strategy to decrease the rate of bitter pit (BP) incidence after standard cold storage (ST). Immediately after harvest, apples were stored for 10 days at 20 degrees C under low O(2). Thereafter, apples were cold-stored (0-4 degrees C) for 4 months and changes were monitored in terms of BP incidence, fruit quality traits and mineral element concentrations. After 4 months cold storage, LOT apples presented a 2.6-fold decrease in the rate of BP incidence (14%) versus the values obtained for standard cold-stored fruits (37% BP incidence). LOT increased flesh firmness, total soluble solids and titratable acidity as compared to the quality traits determined for cold-stored fruits. Lower cortex Ca and Mg concentrations as compared to ST apples were determined in association with LOT, 2 months after cold storage. Application of a LOT prior to cold storage may be a promising strategy to reduce the incidence of BP and preserve fruit quality, which should be further investigated.

Statistical distribution of building lot frontage: application for Tokyo downtown districts

NASA Astrophysics Data System (ADS)

Usui, Hiroyuki

2018-03-01

The frontage of a building lot is the determinant factor of the residential environment. The statistical distribution of building lot frontages shows how the perimeters of urban blocks are shared by building lots for a given density of buildings and roads. For practitioners in urban planning, this is indispensable to identify potential districts which comprise a high percentage of building lots with narrow frontage after subdivision and to reconsider the appropriate criteria for the density of buildings and roads as residential environment indices. In the literature, however, the statistical distribution of building lot frontages and the density of buildings and roads has not been fully researched. In this paper, based on the empirical study in the downtown districts of Tokyo, it is found that (1) a log-normal distribution fits the observed distribution of building lot frontages better than a gamma distribution, which is the model of the size distribution of Poisson Voronoi cells on closed curves; (2) the statistical distribution of building lot frontages statistically follows a log-normal distribution, whose parameters are the gross building density, road density, average road width, the coefficient of variation of building lot frontage, and the ratio of the number of building lot frontages to the number of buildings; and (3) the values of the coefficient of variation of building lot frontages, and that of the ratio of the number of building lot frontages to that of buildings are approximately equal to 0.60 and 1.19, respectively.

Oxygen-induced high diffusion rate of magnesium dopants in GaN/AlGaN based UV LED heterostructures.

PubMed

Michałowski, Paweł Piotr; Złotnik, Sebastian; Sitek, Jakub; Rosiński, Krzysztof; Rudziński, Mariusz

2018-05-23

Further development of GaN/AlGaN based optoelectronic devices requires optimization of the p-type material growth process. In particular, uncontrolled diffusion of Mg dopants may decrease the performance of a device. Thus it is meaningful to study the behavior of Mg and the origins of its diffusion in detail. In this work we have employed secondary ion mass spectrometry to study the diffusion of magnesium in GaN/AlGaN structures. We show that magnesium has a strong tendency to form Mg-H complexes which immobilize Mg atoms and restrain their diffusion. However, these complexes are not present in samples post-growth annealed in an oxygen atmosphere or Al-rich AlGaN structures which naturally have a high oxygen concentration. In these samples, more Mg atoms are free to diffuse and thus the average diffusion length is considerably larger than for a sample annealed in an inert atmosphere.

77 FR 45815 - Indian Child Welfare Act; Designated Tribal Agents for Service of Notice

Federal Register 2010, 2011, 2012, 2013, 2014

2012-08-01

[email protected] Native Village of Port Graham, Patrick Norman, Chief, P.O. Box 5510, Port Graham, AK 99603; Phone: (907) 284-2227; Fax: (907) 284-2222 Native Village of Port Heiden, Gerda Kosbruk, Tribal Administrator and Samantha Holm, Tribal Children Service Worker; 2200 James Street, Port Heiden, AK 99549; Phone...

Progress in p(+)n InP solar cells fabricated by thermal diffusion

NASA Technical Reports Server (NTRS)

Faur, Mircea; Faur, Maria; Flood, D. J.; Brinker, D. J.; Weinberg, I.; Fatemi, N. S.; Vargas-Aburto, Carlos; Goradia, C.; Goradia, Manju

1992-01-01

In SPRAT XI, we proposed that p(sup +)n diffused junction InP solar cells should exhibit a higher conversion efficiency than their n(sup +)p counterparts. This was mainly due to the fact that our p(sup +)n (Cd,S) cell structures consistently showed higher V (sub OC) values than our n(sup +)p (S,Cd) structures. The highest V(sub OC) obtained with the p(sup +)n (Cd,S) cell configuration was 860 mV, as compared to the highest V(sub OC) 840 mV obtained with the n(sup +)p (S,Cd) configuration (AMO, 25 C). In this work, we present the performance results of our most recent thermally diffused cells using the p(sup +)n (Cd,S) structure. We have been able to fabricate cells with V(sub OC) values approaching 880 mV. Our best cell with an unoptimized front contact grid design (GS greater than or equal to 10%) showed a conversion efficiency of 13.4% (AMO, 25 C) without an AR coating layer. The emitter surface was passivated by a -50A P rich oxide. Achievement of such high V(sub OC) values was primarily due to the fabrication of emitter surfaces, having EPD densities as low as 2E2 cm(sup -2) and N(sub a)N(sub d) of about 3E18 cm (sup -3). In addition, our preliminary investigation of p(sup +)n structures seem to suggest that Cd-doped emitter cells are more radiation resistant than Zn-doped emitter cells against both high energy electron and proton irradiation.

7 CFR 42.121 - Sampling and inspection procedures.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 2 2011-01-01 2011-01-01 false Sampling and inspection procedures. 42.121 Section 42... REGULATIONS STANDARDS FOR CONDITION OF FOOD CONTAINERS Skip Lot Sampling and Inspection Procedures § 42.121 Sampling and inspection procedures. (a) Following skip lot procedure authorization, inspect every lot...

7 CFR 42.121 - Sampling and inspection procedures.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 2 2010-01-01 2010-01-01 false Sampling and inspection procedures. 42.121 Section 42... REGULATIONS STANDARDS FOR CONDITION OF FOOD CONTAINERS Skip Lot Sampling and Inspection Procedures § 42.121 Sampling and inspection procedures. (a) Following skip lot procedure authorization, inspect every lot...

First principles calculations of ceramics surfaces and interfaces: Examples from beta-silicon nitride and alpha-alumina

NASA Astrophysics Data System (ADS)

Dunn, Jennifer Synowczynski

The goal of this thesis was to use first principles calculations to provide a fundamental understanding at the atomistic level of the mechanisms (e.g. structural relaxations of ceramic surfaces/interfaces, charge transfer reactions, adsorption and dissociation phenomena, localized debonding) behind macroscopic behavior in ceramics (e.g. fracture toughness, corrosion, catalysis). This thesis includes the results from three independent Density Functional Theory (DFT) studies of beta-Si3N4 and alpha-Al2O 3. Due to the computational complexity of first principles calculations, the models in this thesis do not consider temperature or pressure effects and are limited to describing the behavior of systems containing less than 200 atoms. In future studies, these calculations can be used to train a reactive molecular dynamics force field (REAXFF) so that larger scale phenomena including temperature effects can be explicitly simulated. In the first study, the effect of over 30 dopants on the stability of the interface between beta-Si3N4 grains and the intergranular glassy SiON film (IGF) was investigated. The dopants chosen not only represented commonly known glass modifiers and sintering aides but also enabled us to search for dependencies based on atomic size and electronic orbital configuration. To ensure that the approximations used in our model captured the key physical phenomena occurring on the beta-Si3N4 (100) surface and at the Si3N4/ IGF interface, we compared to experimental data (i.e. High Angle Annual Dark Field-Scanning Transmission Electron Microscopy atomic positions and fracture toughness values (Mikijelj B., 2009)). We identified a computational metric (the interfacial stability factor S) which correlates with experimentally measured fracture toughness values. The interfacial stability factor S is defined as the binding energy of the doped system minus the binding energy of the undoped system, where the binding energy is the total energy of the system minus the sum of the energies of the constituent atoms. In the second study, we performed constrained geometry barrier calculations of the interaction of CO with the (001) beta-Si3N4 surface to answer the following questions: (1) Does the CO combustion product interact with the Si3N4 surface and if so, what is the mechanism? (2) Once adsorbed, can CO further dissociate into isolated surface active C and O species? (3) Is it more energetically favorable for C to diffuse into the bulk beta-Si3N4 or along its surface? and (4) What is the barrier to C diffusing into an amorphous SiO2 intergranular film? Our calculations indicated that CO spontaneously adsorbs to the (001) beta-Si 3N4 surface. However, at ambient temperatures, further dissociation into isolated surface adsorbed C and O species was not thermodynamically or kinetically feasible. The barrier to C diffusing interstitially 1A and 5A into the bulk crystalline lattice is 2.12 and 4.42 eV respectively for a defect free, clean surface. However, the barrier for C surface diffusion is much smaller, ˜ 0.87 eV. Therefore, we concluded that surface is rich in C which can diffuse to the Si3N4/SiO2 interface and contribute to chemical erosion near the grain boundary interface. In the final study, we created a DFT model to investigate the 'inverse spillover effect' that occurs during hydrogen combustion on catalytically active Pt clusters supported by alpha-Al2O3. Our results indicated that the dissociation of O2 was not thermodynamically favored on the alpha-Al2O3 surface. However, both H2 and H2O dissociated, forming hydroxyls with oxygen atoms in the second atomic layer. Once dissociated, the oxygen species could diffuse locally but encountered a large barrier to long-range surface diffusion in the absence of defects or other species. In contrast, the barrier to the long-range surface diffusion of hydrogen was modest under ideal conditions. We also identified several adsorption and dissociation products for Pt, Pt-O [ads] Pt3, O, H, O2, H2, and H 2O on the alpha-Al2O3 (0001) surface and described how these structures changed the surface reconstruction. Specifically, we concluded that the adsorption of molecular H2O, atomic Pt, and Pt trimers changed the termination for the alpha-Al2O3 (0001) surface from aluminum to oxygen terminated in the vicinity of the adsorption products. This should have a dramatic affect on catalytic activity and surface diffusion. We confirmed this for O surface diffusion near surface Al where the presence of atomic Pt decreased the diffusion barrier from 1.17 to 0.22 eV.

A comparative study of three-terminal Hanle signals in CoFe/SiO{sub 2}/n{sup +}-Si and Cu/SiO{sub 2}/n{sup +}-Si tunnel junctions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, Jeong-Hyeon; Cho, B. K., E-mail: chobk@gist.ac.kr; Grünberg Center for Magnetic Nanomaterials, Gwangju Institute of Science and Technology

We performed three-terminal (3T) Hanle measurement for two types of sample series, CoFe/SiO{sub 2}/n{sup +}-Si and Cu/SiO{sub 2}/n{sup +}-Si, with various tunnel resistances. Clear Hanle signal and anomalous scaling between spin resistance-area product and tunnel resistance-area product were observed in CoFe/SiO{sub 2}/n{sup +}-Si devices. In order to explore the origin of the Hanle signal and the impurity-assisted tunneling effect on the Hanle signal in our devices, Hanle measurement in Cu/SiO{sub 2}/n{sup +}-Si devices was performed as well. However, no detectable Hanle signal was observed in Cu/SiO{sub 2}/n{sup +}-Si, even though a lot of samples with various tunnel resistances were studiedmore » in wide temperature and bias voltage ranges. Through a comparative study, it is found that the impurity-assisted tunneling magnetoresistance mechanism would not play a dominant role in the 3T Hanle signal in CoFe/SiO{sub 2}/n{sup +}-Si tunnel junctions, where the SiO{sub 2} was formed by plasma oxidation to minimize impurities.« less

Evaluation of scanning 2D barcoded vaccines to improve data accuracy of vaccines administered.

PubMed

Daily, Ashley; Kennedy, Erin D; Fierro, Leslie A; Reed, Jenica Huddleston; Greene, Michael; Williams, Warren W; Evanson, Heather V; Cox, Regina; Koeppl, Patrick; Gerlach, Ken

2016-11-11

Accurately recording vaccine lot number, expiration date, and product identifiers, in patient records is an important step in improving supply chain management and patient safety in the event of a recall. These data are being encoded on two-dimensional (2D) barcodes on most vaccine vials and syringes. Using electronic vaccine administration records, we evaluated the accuracy of lot number and expiration date entered using 2D barcode scanning compared to traditional manual or drop-down list entry methods. We analyzed 128,573 electronic records of vaccines administered at 32 facilities. We compared the accuracy of records entered using 2D barcode scanning with those entered using traditional methods using chi-square tests and multilevel logistic regression. When 2D barcodes were scanned, lot number data accuracy was 1.8 percentage points higher (94.3-96.1%, P<0.001) and expiration date data accuracy was 11 percentage points higher (84.8-95.8%, P<0.001) compared with traditional methods. In multivariate analysis, lot number was more likely to be accurate (aOR=1.75; 99% CI, 1.57-1.96) as was expiration date (aOR=2.39; 99% CI, 2.12-2.68). When controlling for scanning and other factors, manufacturer, month vaccine was administered, and vaccine type were associated with variation in accuracy for both lot number and expiration date. Two-dimensional barcode scanning shows promise for improving data accuracy of vaccine lot number and expiration date records. Adapting systems to further integrate with 2D barcoding could help increase adoption of 2D barcode scanning technology. Published by Elsevier Ltd.

Estimation of Knudsen diffusion coefficients from tracer experiments conducted with a binary gas system and a porous medium

NASA Astrophysics Data System (ADS)

Hibi, Yoshihiko; Kashihara, Ayumi

2018-03-01

A previous study has reported that Knudsen diffusion coefficients obtained by tracer experiments conducted with a binary gas system and a porous medium are consistently smaller than those obtained by permeability experiments conducted with a single-gas system and a porous medium. To date, however, that study is the only one in which tracer experiments have been conducted with a binary gas system. Therefore, to confirm this difference in Knudsen diffusion coefficients, we used a method we had developed previously to conduct tracer experiments with a binary carbon dioxide-nitrogen gas system and five porous media with permeability coefficients ranging from 10-13 to 10-11 m2. The results showed that the Knudsen diffusion coefficient of N2 (DN2) (cm2/s) was related to the effective permeability coefficient ke (m2) as DN2 = 7.39 × 107ke0.767. Thus, the Knudsen diffusion coefficients of N2 obtained by our tracer experiments were consistently 1/27 of those obtained by permeability experiments conducted with many porous media and air by other researchers. By using an inversion simulation to fit the advection-diffusion equation to the distribution of concentrations at observation points calculated by mathematically solving the equation, we confirmed that the method used to obtain the Knudsen diffusion coefficient in this study yielded accurate values. Moreover, because the Knudsen diffusion coefficient did not differ when columns with two different lengths, 900 and 1500 mm, were used, this column property did not influence the flow of gas in the column. The equation of the dusty gas model already includes obstruction factors for Knudsen diffusion and molecular diffusion, which relate to medium heterogeneity and tortuosity and depend only on the structure of the porous medium. Furthermore, there is no need to take account of any additional correction factor for molecular diffusion except the obstruction factor because molecular diffusion is only treated in a multicomponent gas system. Thus, molecular diffusion considers only the obstruction factor related to tortuosity. Therefore, we introduced a correction factor for a multicomponent gas system into the DGM equation, multiplying the Knudsen diffusion coefficient, which includes the obstruction factor related to tortuosity, by this correction factor. From the present experimental results, the value of this correction factor was 1/27, and it depended only on the structure of the gas system in the porous medium.

Modeling the chemistry of the dense interstellar clouds. I - Observational constraints for the chemistry

NASA Technical Reports Server (NTRS)

Federman, S. R.; Huntress, W. T., Jr.; Prasad, S. S.

1990-01-01

A search for correlations arising from molecular line data is made in order to place constraints on the chemical models of interstellar clouds. At 10 to the 21st H2/sq cm, N(CO) for dark clouds is a factor of six greater than the value for diffuse clouds. This implies that the strength of the UV radiation field where CO shields itself from dissociation is about one-half the strength of the average Galactic field. The dark cloud data indicate that the abundance of CO continues to increase with A(V) for directions with A(V) of 4 mag or less, although less steeply with N(H2) than for diffuse clouds. For H2CO, a quadratic relationship is obtained in plots versus H2 column density. The data suggest a possible turnover at the highest values for A(V). NH3 shows no correlation with H2, C(O-18), HC3N, or HC5N; a strong correlation is found between HC5N and HC3N, indicating a chemical link between the cyanopolyynes.

Quasilinear diffusion coefficients in a finite Larmor radius expansion for ion cyclotron heated plasmas

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, Jungpyo; Wright, John; Bertelli, Nicola

In this study, a reduced model of quasilinear velocity diffusion by a small Larmor radius approximation is derived to couple the Maxwell’s equations and the Fokker Planck equation self-consistently for the ion cyclotron range of frequency waves in a tokamak. The reduced model ensures the important properties of the full model by Kennel-Engelmann diffusion, such as diffusion directions, wave polarizations, and H-theorem. The kinetic energy change (Wdot ) is used to derive the reduced model diffusion coefficients for the fundamental damping (n = 1) and the second harmonic damping (n = 2) to the lowest order of the finite Larmormore » radius expansion. The quasilinear diffusion coefficients are implemented in a coupled code (TORIC-CQL3D) with the equivalent reduced model of the dielectric tensor. We also present the simulations of the ITER minority heating scenario, in which the reduced model is verified within the allowable errors from the full model results.« less

Quasilinear diffusion coefficients in a finite Larmor radius expansion for ion cyclotron heated plasmas

DOE PAGES

Lee, Jungpyo; Wright, John; Bertelli, Nicola; ...

2017-04-24

In this study, a reduced model of quasilinear velocity diffusion by a small Larmor radius approximation is derived to couple the Maxwell’s equations and the Fokker Planck equation self-consistently for the ion cyclotron range of frequency waves in a tokamak. The reduced model ensures the important properties of the full model by Kennel-Engelmann diffusion, such as diffusion directions, wave polarizations, and H-theorem. The kinetic energy change (Wdot ) is used to derive the reduced model diffusion coefficients for the fundamental damping (n = 1) and the second harmonic damping (n = 2) to the lowest order of the finite Larmormore » radius expansion. The quasilinear diffusion coefficients are implemented in a coupled code (TORIC-CQL3D) with the equivalent reduced model of the dielectric tensor. We also present the simulations of the ITER minority heating scenario, in which the reduced model is verified within the allowable errors from the full model results.« less

Ambient-temperature diffusion and gettering of Pt atoms in GaN with surface defect region under 60Co gamma or MeV electron irradiation

NASA Astrophysics Data System (ADS)

Hou, Ruixiang; Li, Lei; Fang, Xin; Xie, Ziang; Li, Shuti; Song, Weidong; Huang, Rong; Zhang, Jicai; Huang, Zengli; Li, Qiangjie; Xu, Wanjing; Fu, Engang; Qin, G. G.

2018-01-01

Generally, the diffusion and gettering of impurities in GaN needs high temperature. Calculated with the ambient-temperature extrapolation value of the high temperature diffusivity of Pt atoms in GaN reported in literature, the time required for Pt atoms diffusing 1 nm in GaN at ambient temperature is about 19 years. Therefore, the ambient-temperature diffusion and gettering of Pt atoms in GaN can hardly be observed. In this work, the ambient-temperature diffusion and gettering of Pt atoms in GaN is reported for the first time. It is demonstrated by use of secondary ion mass spectroscopy that in the condition of introducing a defect region on the GaN film surface by plasma, and subsequently, irradiated by 60Co gamma-ray or 3 MeV electrons, the ambient-temperature diffusion and gettering of Pt atoms in GaN can be detected. It is more obvious with larger irradiation dose and higher plasma power. With a similar surface defect region, the ambient-temperature diffusion and gettering of Pt atoms in GaN stimulated by 3 MeV electron irradiation is more marked than that stimulated by gamma irradiation. The physical mechanism of ambient-temperature diffusion and gettering of Pt atoms in a GaN film with a surface defect region stimulated by gamma or MeV electron irradiation is discussed.

Diffused junction p(+)-n solar cells in bulk GaAs. I Fabrication and cell performance

NASA Technical Reports Server (NTRS)

Bhat, I.; Bhat, K. N.; Mathur, G.; Borrego, J. M.; Ghandhi, S. K.

1984-01-01

This paper describes the fabrication of solar cells made by a simple open tube p(+)-diffusion into bulk n-GaAs. In addition, cell performance is provided as an indicator of the quality of bulk GaAs for this application. Initial results using this technique (12.2 percent efficiency at AM1 for 0.5 sq cm cells) are promising, and indicate directions for materials improvement. It is shown that the introduction of the diffusant (zinc) with point defects significantly affects the material properties and results in an increase in current capability.

7 CFR 868.36 - Loss of identity.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 7 2010-01-01 2010-01-01 false Loss of identity. 868.36 Section 868.36 Agriculture... identity. (a) Lots. The identity of a packaged lot, bulk lot, or sublot of a commodity shall be considered... or location after the time of original inspection, unless the identity is preserved; or (2) More...

7 CFR 868.36 - Loss of identity.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 7 2014-01-01 2014-01-01 false Loss of identity. 868.36 Section 868.36 Agriculture... identity. (a) Lots. The identity of a packaged lot, bulk lot, or sublot of a commodity shall be considered... or location after the time of original inspection, unless the identity is preserved; or (2) More...

7 CFR 868.36 - Loss of identity.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 7 2011-01-01 2011-01-01 false Loss of identity. 868.36 Section 868.36 Agriculture... identity. (a) Lots. The identity of a packaged lot, bulk lot, or sublot of a commodity shall be considered... or location after the time of original inspection, unless the identity is preserved; or (2) More...

7 CFR 868.36 - Loss of identity.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 7 Agriculture 7 2013-01-01 2013-01-01 false Loss of identity. 868.36 Section 868.36 Agriculture... identity. (a) Lots. The identity of a packaged lot, bulk lot, or sublot of a commodity shall be considered... or location after the time of original inspection, unless the identity is preserved; or (2) More...

7 CFR 868.36 - Loss of identity.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 7 Agriculture 7 2012-01-01 2012-01-01 false Loss of identity. 868.36 Section 868.36 Agriculture... identity. (a) Lots. The identity of a packaged lot, bulk lot, or sublot of a commodity shall be considered... or location after the time of original inspection, unless the identity is preserved; or (2) More...

Passivation of phosphorus diffused silicon surfaces with Al{sub 2}O{sub 3}: Influence of surface doping concentration and thermal activation treatments

DOE Office of Scientific and Technical Information (OSTI.GOV)

Richter, Armin, E-mail: armin.richter@ise.fraunhofer.de; Benick, Jan; Kimmerle, Achim

2014-12-28

Thin layers of Al{sub 2}O{sub 3} are well known for the excellent passivation of p-type c-Si surfaces including highly doped p{sup +} emitters, due to a high density of fixed negative charges. Recent results indicate that Al{sub 2}O{sub 3} can also provide a good passivation of certain phosphorus-diffused n{sup +} c-Si surfaces. In this work, we studied the recombination at Al{sub 2}O{sub 3} passivated n{sup +} surfaces theoretically with device simulations and experimentally for Al{sub 2}O{sub 3} deposited with atomic layer deposition. The simulation results indicate that there is a certain surface doping concentration, where the recombination is maximal duemore » to depletion or weak inversion of the charge carriers at the c-Si/Al{sub 2}O{sub 3} interface. This pronounced maximum was also observed experimentally for n{sup +} surfaces passivated either with Al{sub 2}O{sub 3} single layers or stacks of Al{sub 2}O{sub 3} capped by SiN{sub x}, when activated with a low temperature anneal (425 °C). In contrast, for Al{sub 2}O{sub 3}/SiN{sub x} stacks activated with a short high-temperature firing process (800 °C) a significant lower surface recombination was observed for most n{sup +} diffusion profiles without such a pronounced maximum. Based on experimentally determined interface properties and simulation results, we attribute this superior passivation quality after firing to a better chemical surface passivation, quantified by a lower interface defect density, in combination with a lower density of negative fixed charges. These experimental results reveal that Al{sub 2}O{sub 3}/SiN{sub x} stacks can provide not only excellent passivation on p{sup +} surfaces but also on n{sup +} surfaces for a wide range of surface doping concentrations when activated with short high-temperature treatments.« less

Some field experience with subsynchronous vibration of centrifugal compressors

NASA Technical Reports Server (NTRS)

Wang, Xi-Xuan; Gu, Jin-Chu; Shen, Qin-Gen; Hua, Yong-Li; Zhu, Lan-Sheng; Du, Yun-Tian

1989-01-01

A lot of large chemical fertilizer plants producing 1000 ton NH3/day and 1700 ton urea/day were constructed in the 1970's in China. During operation, subsynchronous vibration takes place occasionally in some of the large turbine-compressor sets and has resulted in heavy economic losses. Two cases of subsynchronous vibration are described: Self-excited vibration of the low-pressure (LP) cylinder of one kind of N2-H2 multistage compressor; and Forced subsynchronous vibration of the high-pressure (HP) cylinder of the CO2 compressor.

Piroplasmosis in wildlife: Babesia and Theileria affecting free-ranging ungulates and carnivores in the Italian Alps.

PubMed

Zanet, Stefania; Trisciuoglio, Anna; Bottero, Elisa; de Mera, Isabel Garcia Fernández; Gortazar, Christian; Carpignano, Maria Grazia; Ferroglio, Ezio

2014-02-17

Piroplasmosis are among the most relevant diseases of domestic animals. Babesia is emerging as cause of tick-borne zoonosis worldwide and free-living animals are reservoir hosts of several zoonotic Babesia species. We investigated the epidemiology of Babesia spp. and Theileria spp. in wild ungulates and carnivores from Northern Italy to determine which of these apicomplexan species circulate in wildlife and their prevalence of infection. PCR amplification of the V4 hyper-variable region of the 18S rDNA of Babesia sp./Theileria sp was carried out on spleen samples of 1036 wild animals: Roe deer Capreolus capreolus (n = 462), Red deer Cervus elaphus (n = 52), Alpine Chamois Rupicapra rupicapra (n = 36), Fallow deer Dama dama (n = 17), Wild boar Sus scrofa (n = 257), Red fox Vulpes vulpes (n = 205) and Wolf Canis lupus (n = 7). Selected positive samples were sequenced to determine the species of amplified Babesia/Theileria DNA. Babesia/Theileria DNA was found with a mean prevalence of 9.94% (IC95% 8.27-11.91). The only piroplasms found in carnivores was Theileria annae, which was detected in two foxes (0.98%; IC95% 0.27-3.49). Red deer showed the highest prevalence of infection (44.23%; IC95% 31.6-57.66), followed by Alpine chamois (22.22%; IC95% 11.71-38.08), Roe deer (12.55%; IC95% 9.84-15.89), and Wild boar (4.67%; IC95% 2.69-7.98). Genetic analysis identified Babesia capreoli as the most prevalent piroplasmid found in Alpine chamois, Roe deer and Red deer, followed by Babesia bigemina (found in Roe deer, Red deer and Wild boar), and the zoonotic Babesia venatorum (formerly Babesia sp. EU1) isolated from 2 Roe deer. Piroplasmids of the genus Theileria were identified in Wild boar and Red deer. The present study offers novel insights into the role of wildlife in Babesia/Theileria epidemiology, as well as relevant information on genetic variability of piroplasmids infecting wild ungulates and carnivores.

[Application of anoptomagnetic probe Gd-DO3A-EA-FITC in imaging and analyzing the brain interstitial space].

PubMed

Li, Y Q; Sheng, Y; Liang, L; Zhao, Y; Li, H Y; Bai, N; Wang, T; Yuan, L; Han, H B

2018-04-18

To investigate the application of the optical magnetic bimodal molecular probe Gd-DO3A-ethylthiouret-fluorescein isothiocyanate (Gd -DO3A-EA-FITC) in brain tissue imaging and brain interstitial space (ISS). In the study, 24 male SD rats were randomly divided into 3 groups, including magnetic probe group (n=6), optical probe group (n=6) and optical magnetic bimodal probe group (n=12), then the optical magnetic bimodal probe group was divided equally into magnetic probe subgroup (n=6) and optical probe subgroup (n=6). Referencing the brain stereotaxic atlas, the coronal globus pallidus as center level, the probes including gadolinium-diethylene triamine pentaacetic acid (Gd-DTPA), fluorescein isothiocyanate (FITC) and Gd-DO3A-EA-FITC of 2 μL (10 mmol/L) were injected into the caudate nucleus respectively, magnetic resonance imaging (MRI) was performed in the magnetic probe group and magnetic probe subgroup to image the dynamic diffusion and distribution of the probes in the brain ISS, a self-developed brain ISS image processing system was used to measure the diffusion coefficient, clearance, volume fraction and half-time in these two groups. Laser scanning confocal microscope (LSCM) was performed in vitro in the optical probe group and optical probe subgroup for fluorescence imaging at the time points 2 hours after the injection of the probe, and the distribution in the oblique sagittal slice was compared with the result of the first two groups. For the magnetic probe group and magnetic probe subgroup, there were the same imaging results between the probes of Gd-DTPA and Gd-DO3A-EA-FITC. The diffusion parameters of Gd-DTPA and Gd-DO3A-EA-FITC were as follows: the average diffusion coefficients [(3.31±0.11)×10 -4 mm 2 /s vs. (3.37±0.15)×10 -4 mm 2 /s, t=0.942, P=0.360], the clearance [(3.04±0.37) mmol/L vs. (2.90±0.51) mmol/L, t=0.640, P=0.531], the volume fractions (17.18%±0.14% vs. 17.31%±0.15%, t=1.961, P=0.068), the half-time [(86.58±3.31) min vs. (84.61±2.38) min, t=1.412, P=0.177], the diffusion areas [(23.25±0.68) mm 2 vs. (22.71±1.00) mm 2 , t=1.100, P=0.297]. The statistical analysis of each brain was made by t test, and the diffusion parameters were not statistically significant. Moreover, for the optical probe group and optical probe subgroup, the diffusion area of Gd-DO3A-EA-FITC [(22.61±1.16) mm 2 ] was slightly larger than that of FITC [(22.10±1.29) mm 2 ], the statistical analysis of each brain was made by t test, and the diffusion parameters were not statistically significant (t=0.713, P=0.492). Gd-DO3A-EA-FITC shows the same imaging results as the traditional GD-DTPA, and it can be used in measuring brain ISS.

On matrix diffusion: formulations, solution methods and qualitative effects

NASA Astrophysics Data System (ADS)

Carrera, Jesús; Sánchez-Vila, Xavier; Benet, Inmaculada; Medina, Agustín; Galarza, Germán; Guimerà, Jordi

Matrix diffusion has become widely recognized as an important transport mechanism. Unfortunately, accounting for matrix diffusion complicates solute-transport simulations. This problem has led to simplified formulations, partly motivated by the solution method. As a result, some confusion has been generated about how to properly pose the problem. One of the objectives of this work is to find some unity among existing formulations and solution methods. In doing so, some asymptotic properties of matrix diffusion are derived. Specifically, early-time behavior (short tests) depends only on φm2RmDm / Lm2, whereas late-time behavior (long tracer tests) depends only on φmRm, and not on matrix diffusion coefficient or block size and shape. The latter is always true for mean arrival time. These properties help in: (a) analyzing the qualitative behavior of matrix diffusion; (b) explaining one paradox of solute transport through fractured rocks (the apparent dependence of porosity on travel time); (c) discriminating between matrix diffusion and other problems (such as kinetic sorption or heterogeneity); and (d) describing identifiability problems and ways to overcome them. RésuméLa diffusion matricielle est un phénomène reconnu maintenant comme un mécanisme de transport important. Malheureusement, la prise en compte de la diffusion matricielle complique la simulation du transport de soluté. Ce problème a conduit à des formulations simplifiées, en partie à cause de la méthode de résolution. Il s'en est suivi une certaine confusion sur la façon de poser correctement le problème. L'un des objectifs de ce travail est de trouver une certaine unité parmi les formulations et les méthodes de résolution. C'est ainsi que certaines propriétés asymptotiques de la diffusion matricielle ont été dérivées. En particulier, le comportement à l'origine (expériences de traçage courtes) dépend uniquement du terme φm2RmDm / Lm2, alors que le comportement à long terme (traçages de longue durée) ne dépend que de φmRm, et non pas du coefficient de diffusion matricielle ou de la forme et de la taille des blocs. Ceci est toujours vrai pour le temps moyen d'arrivée. Ces propriétés permettent: (a) d'analyser le comportement de la diffusion matricielle; (b) d'expliquer un paradoxe du transport de soluté dans les roches fracturées (la dépendance apparente entre la porosité et le temps de transit); (c) de faire la distinction entre la diffusion matricielle et d'autres problèmes, tels que la sorption cinétique ou l'hétérogénéité et (d) de décrire les problèmes d'identification et les façons de les résoudre. Resumen La difusión en la matriz está reconocida en la actualidad como un importante mecanismo de transporte de solutos. Desgraciadamente, tener en cuenta este proceso complica las simulaciones de transporte. Esto ha llevado a una serie de formulaciones simplificadas, motivadas en parte por el propio método de solución. Como resultado, se ha producido cierta confusión respecto a cuál es la manera adecuada de formular el problema. Uno de los objetivos de este trabajo es encontrar una cierta unidad entre las formulaciones existentes y los métodos de solución, lo que conduce a algunas propiedades asintóticas de la difusión en la matriz; específicamente, se comprueba que el comportamiento para tiempos cortos depende únicamente del parámetro φm2RmDm / Lm2, mientras que el de tiempos largos depende sólo de φmRm, y no del coeficiente de difusión en la matriz o del tamaño o forma del bloque. Esto último también es cierto, en todos los casos, respecto al tiempo medio de llegada (definido como el valor esperado de la distribución de tiempos de llegada). Estas propiedades son útiles para: (a) analizar el comportamiento cualitativo de la difusión en la matriz; (b) explicar una de las paradojas del transporte de solutos en medios fracturados, la aparente dependencia entre porosidad y tiempo de llegada; (c) discriminar entre difusión en la matriz y otros problemas, como las reacciones con cinética química o la heterogeneidad; y (d) describir problemas de identificabilidad y posibles modos de resolverlos.

Electrophilic-Nucleophilic Dualism of Nickel(II) toward Ni···I Noncovalent Interactions: Semicoordination of Iodine Centers via Electron Belt and Halogen Bonding via σ-Hole.

PubMed

Bikbaeva, Zarina M; Ivanov, Daniil M; Novikov, Alexander S; Ananyev, Ivan V; Bokach, Nadezhda A; Kukushkin, Vadim Yu

2017-11-06

The nitrosoguanidinate complex [Ni{NH═C(NMe 2 )NN(O)} 2 ] (1) was cocrystallized with I 2 and sym-trifluorotriiodobenzene (FIB) to give associates 1·2I 2 and 1·2FIB. Structures of these solid species were studied by XRD followed by topological analysis of the electron density distribution within the framework of Bader's approach (QTAIM) at the M06/DZP-DKH level of theory and Hirshfeld surface analysis. Our results along with inspection of XRD (CCDC) data, accompanied by the theoretical calculations, allowed the identification of three types of Ni···I contacts. The Ni···I semicoordination of the electrophilic nickel(II) center with electron belt of I 2 was observed in 1·2I 2 , the metal-involving halogen bonding between the nucleophilic nickel(II)-d z 2 center and σ-hole of iodine center was recognized and confirmed theoretically in the structure of [FeNi(CN) 4 (IPz)(H 2 O)] n (IPz = 4-N-coordinated 2-I-pyrazine), whereas the arrangement of FIB in 1·2FIB provides a boundary case between the semicoordination and the halogen Ni···I bondings. In 1·2I 2 and 1·2FIB, noncovalent interactions were studied by variable temperature XRD detecting the expansion of noncovalent contacts with preservation of covalent bond lengths upon the temperature increase from 100 to 300 K. The nature and energies of all identified types of the Ni···I noncovalent interactions in the obtained (1·2I 2 and 1·2FIB) and in the previously reported ([FeNi(CN) 4 (IPz)(H 2 O)] n , [NiL 2 ](I 3 ) 2 ·2I 2 (L = o-phenylene-bis(dimethylphosphine), [NiL]I 2 (L = 1,4,8,11-tetra-azacyclotetradecane), Ni(en) 2 ] n [AgI 2 ] 2n (en = ethylenediamine), and [NiL](ClO 4 ) (L = 4-iodo-2-((2-(2-(2-pyridyl)ethylsulfanyl)ethylimino)methyl)-phenolate)) structures were studied theoretically. The estimated strengths of these Ni···I noncovalent contacts vary from 1.6 to 4.1 kcal/mol and, as expected, become weaker on heating. This work is the first emphasizing electrophilic-nucleophilic dualism of any metal center toward noncovalent interactions.

Formation and coarsening of near-surface Ga nanoparticles on SiN{sub x}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Canniff, J. C.; Jeon, S.; Huang, S.

2015-06-15

We have investigated the formation and coarsening of near-surface Ga nanoparticles (NPs) in SiN{sub x} using Ga{sup +} focused-ion-beam-irradiation of SiN{sub x}, followed by rapid thermal annealing. For surfaces with minimal curvature, diffusive growth is apparent, leading to nearly close packed arrays with NP diameters as small as 3 nm and densities as high as ∼4 × 10{sup 12} cm{sup −2}. The diffusive flux increases with annealing temperature, leading to NP coarsening by Ostwald ripening. For surfaces with increased curvature, diffusion towards the valleys also increases during annealing, leading to Ga NP coalescence and a bi-modal distribution of NP sizes.

Photonic crystal lasers using wavelength-scale embedded active region

NASA Astrophysics Data System (ADS)

Matsuo, Shinji; Sato, Tomonari; Takeda, Koji; Shinya, Akihiko; Nozaki, Kengo; Kuramochi, Eiichi; Taniyama, Hideaki; Notomi, Masaya; Fujii, Takuro; Hasebe, Koichi; Kakitsuka, Takaaki

2014-01-01

Lasers with ultra-low operating energy are desired for use in chip-to-chip and on-chip optical interconnects. If we are to reduce the operating energy, we must reduce the active volume. Therefore, a photonic crystal (PhC) laser with a wavelength-scale cavity has attracted a lot of attention because a PhC provides a large Q-factor with a small volume. To improve this device's performance, we employ an embedded active region structure in which the wavelength-scale active region is buried with an InP PhC slab. This structure enables us to achieve effective confinement of both carriers and photons, and to improve the thermal resistance of the device. Thus, we have obtained a large external differential quantum efficiency of 55% and an output power of -10 dBm by optical pumping. For electrical pumping, we use a lateral p-i-n structure that employs Zn diffusion and Si ion implantation for p-type and n-type doping, respectively. We have achieved room-temperature continuous-wave operation with a threshold current of 7.8 µA and a maximum 3 dB bandwidth of 16.2 GHz. The results of an experimental bit error rate measurement with a 10 Gbit s-1 NRZ signal reveal the minimum operating energy for transferring a single bit of 5.5 fJ. These results show the potential of this laser to be used for very short reach interconnects. We also describe the optimal design of cavity quality (Q) factor in terms of achieving a large output power with a low operating energy using a calculation based on rate equations. When we assume an internal absorption loss of 20 cm-1, the optimized coupling Q-factor is 2000.

A Comparative Study on the Lot Release Systems for Vaccines as of 2016.

PubMed

Fujita, Kentaro; Naito, Seishiro; Ochiai, Masaki; Konda, Toshifumi; Kato, Atsushi

2017-09-25

Many countries have already established their own vaccine lot release system that is designed for each country's situation: while the World Health Organization promotes for the convergence of these regulatory systems so that vaccines of assured quality are provided globally. We conducted a questionnaire-based investigation of the lot release systems for vaccines in 7 countries and 2 regions. We found that a review of the summary protocol by the National Regulatory Authorities was commonly applied for the independent lot release of vaccines, however, we also noted some diversity between countries, especially in regard to the testing policy. Some countries and regions, including Japan, regularly tested every lot of vaccines, whereas the frequency of these tests was reduced in other countries and regions as determined based on the risk assessment of these products. Test items selected for the lot release varied among the countries or regions investigated, although there was a tendency to prioritize the potency tests. An understanding of the lot release policy may contribute to improving and harmonizing the lot release system globally in the future.

Diffusive and rotational dynamics of condensed n-H2 confined in MCM-41

DOE Office of Scientific and Technical Information (OSTI.GOV)

Prisk, Timothy R; Bryan, Matthew; Sokol, Paul E

2014-01-01

In this paper, we report an inelastic neutron scattering study of liquid and solid n-H2 confined within MCM-41. This is a high surface area, mesoporous silica glass with a narrow pore size distribution centered at 3.5 nm. The scattering data provides information about the diffusive and rotational dynamics of the adsorbed n-H2 at low temperatures. In the liquid state, the neutron scattering data demonstrates that only a fraction of the adsorbed o-H2 is mobile on the picosecond time scale. This mobile fraction undergoes liquid-like jump diffusion, and values for the residence time t and effective mean-squared displacement hu2i are reportedmore » as a function of pore filling. In the solid state, the rotational energy levels of adsorbed H2 are strongly perturbed from their free quantum rotor behavior in the bulk solid. The underlying orientational potential of the hindered rotors is due to the surface roughness and heterogeneity of the MCM-41 pore walls. This potential is compared to the hindering potential of other porous silicas, such as Vycor. Strong selective adsorption makes the interfacial layer rich in o-H2, leaving the inner core volume consisting of a depleted mixture of o-H2 and p-H2.« less

A photographic method for estimating wear of coal tar sealcoat from parking lots

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mateo Scoggins; Tom Ennis; Nathan Parker

2009-07-01

Coal-tar-based sealcoat has been recognized as an important source of PAHs to the environment through wear and transport via stormwater runoff. Sealcoat removal rates have not been measured or even estimated in the literature due to the complex array of physical and chemical process involved. A photographic study was conducted that incorporates all sources of wear using 10 coal tar-sealed parking lots in Austin, Texas, with sealcoat age ranging from 0 to 5 years. Randomly located photographs from each parking lot were analyzed digitally to quantify black sealed areas versus lighter colored unsealed areas at the pixel level. The resultsmore » indicate that coal tar sealcoat wears off of the driving areas of parking lots at a rate of approximately 4.7% per year, and from the parking areas of the lots at a rate of approximately 1.4% per year. The overall annual loss of sealcoat was calculated at 2.4%. This results in an annual delivery to the environment of 0.51 g of PAHs per m{sup 2} of coal tar-sealed parking lot. These values provide a more robust and much higher estimate of loading of PAHs from coal tar sealcoated parking lots when compared to other available measures. 20 refs., 6 figs.« less

[Analysis of drug advertising in Spanish gynecology journals].

PubMed

Diez, Brezo; Hidalgo, Agustín

2012-01-01

To determine advertising pressure in three Spanish gynecology journals, to describe the characteristics of the drugs advertised and to analyze compliance with current regulatory standards in drug advertisements. We identified the number of advertisements, the characteristics of the drugs advertised, the minimum information required by legislation and the advertising message in the selected journals. A total of 139 advertisements were identified, corresponding to 33 distinct products (28 prescription medicines and five over-the-counter drugs). Advertising pressures were 18.13% in Progresos de Obstetricia y Ginecología, 16.18% in Acta Ginecológica and 5.21% in Clínica e Investigación en Ginecología y Obstetricia. Legislative failure occurred in 82.14% of the advertisements and in 22.22% of slogans, while 41.46% of advertising messages were misleading. A critical attitude to advertising among health professionals is advisable. Information contained in advertisements should be contrasted with official and other independent sources. Copyright © 2011 SESPAS. Published by Elsevier España. All rights reserved.

Assessing gull abundance and food availability in urban parking lots

USGS Publications Warehouse

Clark, Daniel E.; Whitney, Jillian J.; MacKenzie, Kenneth G.; Koenen, Kiana K. G.; DeStefano, Stephen

2015-01-01

Feeding birds is a common activity throughout the world; yet, little is known about the extent of feeding gulls in urban areas. We monitored 8 parking lots in central Massachusetts, USA, during the fall and winter of 2011 to 2013 in 4 monitoring sessions to document the number of gulls present, the frequency of human–gull feeding interactions, and the effectiveness of signage and direct interaction in reducing human-provisioned food. Parking lots were divided between “education” and “no-education” lots. In education lots, we erected signs about problems caused when people feed birds and also asked people to stop feeding birds. We did not erect signs or ask people to stop feeding birds at no-education lots. We spent >1,200 hours in parking lots (range = 136 to 200 hours per parking lot), and gulls were counted every 20 minutes. We conducted >4,000 counts, and ring-billed gulls (Lorus delawarensis) accounted for 98% of all gulls. Our educational efforts were minimally effective. There were fewer feedings (P = 0.01) in education lots during one of the monitoring sessions but significantly more gulls (P = 0.008) in education lots during 2 monitoring sessions. While there was a marginal decrease (P = 0.055) in the number of feedings after no-education lots were transformed into education lots, there was no difference in gull numbers in these lots (P = 0.16). Education appears to have some influence in reducing the number of people feeding gulls, but our efforts were not able to reduce the number of human feeders or the amount of food enough to influence the number of gulls using parking lots.

Holographic wavefront sensor, based on diffuse Fourier holography

NASA Astrophysics Data System (ADS)

Gorelaya, Alina; Orlov, Vyacheslav; Venediktov, Vladimir

2017-09-01

Many areas of optical science and technology require fast and accurate measurement of the radiation wavefront shape. Today there are known a lot of wavefront sensor (WFS) techniques, and their number is growing up. The last years have brought a growing interest in several schematics of WFS, employing the holography principles and holographic optical elements (HOE). Some of these devices are just the improved versions of the standard and most popular Shack-Hartman WFS, while other are based on the intrinsic features of HOE. A holographic mode wavefront sensor is proposed, which makes it possible to measure up to several tens of wavefront modes. The increase in the number of measured modes is implemented using the conversion of a light wave entering the sensor into a wide diffuse light beam, which allows one to record a large number of holograms, each intended for measuring one of the modes.

Relationship of In Vivo MR Parameters to Histopathological and Molecular Characteristics of Newly Diagnosed, Nonenhancing Lower-Grade Gliomas.

PubMed

Luks, Tracy L; McKnight, Tracy Richmond; Jalbert, Llewellyn E; Williams, Aurelia; Neill, Evan; Lobo, Khadjia A; Persson, Anders I; Perry, Arie; Phillips, Joanna J; Molinaro, Annette M; Chang, Susan M; Nelson, Sarah J

2018-06-05

The goal of this research was to elucidate the relationship between WHO 2016 molecular classifications of newly diagnosed, nonenhancing lower grade gliomas (LrGG), tissue sample histopathology, and magnetic resonance (MR) parameters derived from diffusion, perfusion, and 1 H spectroscopic imaging from the tissue sample locations and the entire tumor. A total of 135 patients were scanned prior to initial surgery, with tumor cellularity scores obtained from 88 image-guided tissue samples. MR parameters were obtained from corresponding sample locations, and histograms of normalized MR parameters within the T2 fluid-attenuated inversion recovery lesion were analyzed in order to evaluate differences between subgroups. For tissue samples, higher tumor scores were related to increased normalized apparent diffusion coefficient (nADC), lower fractional anisotropy (nFA), lower cerebral blood volume (nCBV), higher choline (nCho), and lower N-acetylaspartate (nNAA). Within the T2 lesion, higher tumor grade was associated with higher nADC, lower nFA, and higher Cho to NAA index. Pathological analysis confirmed that diffusion and metabolic parameters increased and perfusion decreased with tumor cellularity. This information can be used to select targets for tissue sampling and to aid in making decisions about treating residual disease. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

Dynamics of an integral membrane peptide: a deuterium NMR relaxation study of gramicidin.

PubMed Central

Prosser, R S; Davis, J H

1994-01-01

Solid state deuterium (2H) NMR inversion-recovery and Jeener-Broekaert relaxation experiments were performed on oriented multilamellar dispersions consisting of 1,2-dilauroyl-sn-glycero-3-phosphatidylcholine and 2H exchange-labeled gramicidin D, at a lipid to protein molar ratio (L/P) of 15:1, in order to study the dynamics of the channel conformation of the peptide in a liquid crystalline phase. Our dynamic model for the whole body motions of the peptide includes diffusion of the peptide around its helix axis and a wobbling diffusion around a second axis perpendicular to the local bilayer normal in a simple Maier-Saupe mean field potential. This anisotropic diffusion is characterized by the correlation times, tau R parallel and tau R perpendicular. Aligning the bilayer normal perpendicular to the magnetic field and graphing the relaxation rate, 1/T1Z, as a function of (1-S2N-2H), where S2N-2H represents the orientational order parameter, wer were able to estimate the correlation time, tau R parallel, for rotational diffusion. Although in the quadrupolar splitting, which varies as (3 cos2 theta D-1), has in general two possible solutions to theta D in the range 0 < or = theta D < or = 90 degrees, the 1/T1Z vs. (1-S2N-2H) curve can be used to determine a single value of theta D in this range. Thus, the 1/T1Z vs. (1-S2N-2H) profile can be used both to define the axial diffusion rate and to remove potential structural ambiguities in the splittings. The T1Z anisotropy permits us to solve for the two correlation times (tau R parallel = 6.8 x 10(-9) s and tau R perpendicular = 6 x 10(-6) s). The simulated parameters were corroborated by a Jeener-Broekaert experiment where the bilayer normal was parallel to the principal magnetic field. At this orientation the ratio, J2(2 omega 0)/J1(omega 0) was obtained in order to estimate the strength of the restoring potential in a model-independent fashion. This measurement yields the rms angle, 1/2 (= 16 +/- 2 degrees at 34 degrees C), formed by the peptide helix axis and the average bilayer normal. PMID:7520294

Distortion-free diffusion tensor imaging for evaluation of lumbar nerve roots: Utility of direct coronal single-shot turbo spin-echo diffusion sequence.

PubMed

Sakai, Takayuki; Doi, Kunio; Yoneyama, Masami; Watanabe, Atsuya; Miyati, Tosiaki; Yanagawa, Noriyuki

2018-06-01

Diffusion tensor imaging (DTI) based on a single-shot echo planer imaging (EPI-DTI) is an established method that has been used for evaluation of lumbar nerve disorders in previous studies, but EPI-DTI has problems such as a long acquisition time, due to a lot of axial slices, and geometric distortion. To solve these problems, we attempted to apply DTI based on a single-shot turbo spin echo (TSE-DTI) with direct coronal acquisition. Our purpose in this study was to investigate whether TSE-DTI may be more useful for evaluation of lumbar nerve disorders than EPI-DTI. First, lumbar nerve roots of five healthy volunteers were evaluated for optimization of imaging parameters with TSE-DTI including b-values and the number of motion proving gradient (MPG) directions. Subsequently, optimized TSE-DTI was quantitatively compared with conventional EPI-DTI by using fractional anisotropy (FA) values and visual scores in subjective visual evaluation of tractography. Lumbar nerve roots of six patients, who had unilateral neurologic symptoms in one leg, were evaluated by the optimized TSE-DTI. TSE-DTI with b-value of 400 s/mm 2 and 32 diffusion-directions could reduce the image distortion compared with EPI-DTI, and showed that the average FA values on the symptomatic side for six patients were significantly lower than those on the non-symptomatic side (P < 0.05). Tractography with TSE-DTI might show damaged areas of lumbar nerve roots without severe image distortion. TSE-DTI might improve the reproducibility in measurements of FA values for quantification of a nerve disorder, and would become a useful tool for diagnosis of low back pain. Copyright © 2018 Elsevier Inc. All rights reserved.

Separation of Anisotropy and Exchange Broadening Using 15N CSA- 15N- 1H Dipole-Dipole Relaxation Cross-Correlation Experiments

NASA Astrophysics Data System (ADS)

Renner, Christian; Holak, Tad A.

2000-08-01

Based on the measurement of cross-correlation rates between 15N CSA and 15N-1H dipole-dipole relaxation we propose a procedure for separating exchange contributions to transverse relaxation rates (R2 = 1/T2) from effects caused by anisotropic rotational diffusion of the protein molecule. This approach determines the influence of anisotropy and chemical exchange processes independently and therefore circumvents difficulties associated with the currently standard use of T1/T2 ratios to determine the rotational diffusion tensor. We find from computer simulations that, in the presence of even small amounts of internal flexibility, fitting T1/T2 ratios tends to underestimate the anisotropy of overall tumbling. An additional problem exists when the N-H bond vector directions are not distributed homogeneously over the surface of a unit sphere, such as in helix bundles or β-sheets. Such a case was found in segment 4 of the gelation factor (ABP 120), an F-actin cross-linking protein, in which the diffusion tensor cannot be calculated from T1/T2 ratios. The 15N CSA tensor of the residues for this β-sheet protein was found to vary even within secondary structure elements. The use of a common value for the whole protein molecule therefore might be an oversimplification. Using our approach it is immediately apparent that no exchange broadening exists for segment 4 although strongly reduced T2 relaxation times for several residues could be mistaken as indications for exchange processes.

Acoustic Directivity Patterns for Army Weapons. Supplement 1

DTIC Science & Technology

1982-09-01

12. GOVT ACCESSION NO, S. RECIPIENT’S CATALOG NUMW9M CERL- TR -N-60 A l 4_ 4. TITLE (and Subdti) S. TYPE OF REPORT & PERIOD COVERED ACOUSTIC DIRECTIVITY...5.4 36.1 124.9 -13-4 01.3 7032 119.2 -11.1 F kah 11816 19.3 IS. 16 1007 14179 17 3.MVUh.N 1963 -13.8 51.3 US66 135.3 -11.4 786& 76.1 136. -124 Imukm... ISO .$ sti.l 1342 -12.7 1116 16.7 131.5 113. 1816 111.8 9815L Is"I 22C- 154.2 .12.6 9611 90. 1511.4 -15.2 IW1 111.7 36.4 -ILU 146 91.7 366.5 lots5

Managing Life-Cycle Information of Aircraft Components

DTIC Science & Technology

2012-04-01

Journal of Production Economics , 128(1), 393–403. Ferrer, G., Dew, n., & Apte, U. (2010). When is RFiD right for your Service? International Journal of Production Economics , 124... International Journal of Production Economics , 133(2), 612–621. Hozak, K., & Hill, J. (2010). The material handling trade-off when lot splitting with...pp. 38–56). erlangen, Germany: Publicis Publishing. Ferrer, G. (2010). Open architecture, inventory

SH Observations In and Toward Sgr B2(N): Linking the Missing Sulfur

NASA Astrophysics Data System (ADS)

McCarthy, Michael

Where is the missing sulfur in the molecular reservoir of the interstellar medium (ISM)? In the warm gas phase ISM, the abundance of sulfur is nearly equivalent to its solar value, but in the cold, diffuse clouds which span the space between stars, sulfur is depleted by several orders of magnitude. Our inability to account for this depletion represents a significant gap in our understanding of the fundamental chemical and physical processes occurring in the primordial reservoirs of gas and dust in the ISM. Central to this chemistry is SH, a radical for which few observations presently exist, and for which SOFIA is uniquely capable of accessing in its ground rotational state. We propose observations of SH in the cold, shocked molecular shell surrounding Sgr B2(N), and, simultaneously, in diffuse and translucent clouds along the line of sight to Sgr B2(N). We will constrain the abundance of SH, and compare it to previous measurements of SO, CS, C_2S, HCS(+) , H_2CS, and H_2S in these sources which span the evolutionary timescale from diffuse clouds to dense, cold shocked regions.

Concentration dependence of lipopolymer self-diffusion in supported bilayer membranes

PubMed Central

Zhang, Huai-Ying; Hill, Reghan J.

2011-01-01

Self-diffusion coefficients of poly(ethylene glycol)2k-derivatized lipids (DSPE-PEG2k-CF) in glass-supported DOPC phospholipid bilayers are ascertained from quantitative fluorescence recovery after photobleaching (FRAP). We developed a first-order reaction–diffusion model to ascertain the bleaching constant, mobile fraction and lipopolymer self-diffusion coefficient Ds at concentrations in the range c ≈ 0.5–5 mol%. In contrast to control experiments with 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine-N-(7-nitro-2-1,3-benzoxadiazol-4-yl) (ammonium salt) (DOPE-NBD) in 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC), the lipopolymer self-diffusion coefficient decreases monotonically with increasing concentration, without a distinguishing mushroom-to-brush transition. Our data yield a correlation Ds = D0/(1 + αc), where D0 ≈ 3.36 µm2 s−1 and α ≈ 0.56 (with c expressed as a mole percent). Interpreting the dilute limit with the Scalettar–Abney–Owicki statistical mechanical theory for transmembrane proteins yields an effective disc radius ae ≈ 2.41 nm. On the other hand, the Bussell–Koch–Hammer theory, which includes hydrodynamic interactions, yields ae ≈ 2.92 nm. As expected, both measures are smaller than the Flory radius of the 2 kDa poly(ethylene glycol) (PEG) chains, RF ≈ 3.83 nm, and significantly larger than the nominal radius of the phospholipid heads, al ≈ 0.46 nm. The diffusion coefficient at infinite dilution D0 was interpreted using the Evans–Sackmann theory, furnishing an inter-leaflet frictional drag coefficient bs ≈ 1.33 × 108 N s m−3. Our results suggest that lipopolymer interactions are dominated by the excluded volume of the PEG-chain segments, with frictional drag dominated by the two-dimensional bilayer hydrodynamics. PMID:20504804

Very Efficient High-order Hyperbolic Schemes for Time-dependent Advection Diffusion Problems: Third-, Fourth-, and Sixth-order

DTIC Science & Technology

2014-07-07

boundary condition (x ¼ 7p =2; j ¼ 2p; U ¼ 1; m ¼ 1) on N ¼ 10 uniform nodes (Dt ¼ 0:01.) Table 10 Unsteady linear advection–diffusion problem with periodic...500 3rd 55 2 4th 55 2 6th 55 2 1000 3rd 116 2 4th 116 2 6th 116 2 Table 11 Unsteady linear advection–diffusion problem with oscillatory BC (x ¼ 7p =2; a...dependent problem with oscillatory BC (x ¼ 7p =2; a ¼ 1.) using the third-order RD-GT scheme with the BDF3 time discretization. Number of nodes Dt (BDF3

Evaluation of pH and calcium ion diffusion from calcium hydroxide pastes and MTA.

PubMed

Sáez, María Del M; López, Gabriela L; Atlas, Diana; de la Casa, María L

2017-04-01

The aim of this ex vivo study was to evaluate changes in pH and calcium ion diffusion through root dentin from calcium hydroxide (Ca (OH) 2 ) and mineral trioxide aggregate (MTA) pastes at 7, 30 and 60 days; and the relationship between pH and ion diffusion. Thirty-two human premolars were used. Crowns were sectioned and root canals instrumented and filled in with the following preparations: 1) Ca(OH) 2 + distilled water (n=7); 2) Ca(OH) 2 + 0.1% chlorhexidine gluconate (n=7); 3) MTA + distilled water (n=7); 4) MTA + 0.1% chlorhexidine gluconate (CHX) (n=7); 5) distilled water (n=2) (control); 6) 0.1% chlorhexidine gluconate (n=2) (control). The apex and coronary opening were sealed with IRM. Roots were placed in Eppendorf tubes with 1 ml distilled water at 37°C and 100% humidity. At baseline, 7, 30 and 60 days, pH was measured with pH meter, and calcium ion content in the solution was analyzed by atomic absorption spectrophotometry. The data were statistically analyzed using ANOVA, simple linear regression analysis and Pearson's correlation test. The highest pH values were achieved with calcium hydroxide pastes at 60 days (p ≤ 0.05). Calcium ions were released in all groups. The calcium hydroxide paste with distilled water at 60 days had the highest calcium ion value (p ≤ 0.01). There was a positive correlation between calcium and pH values. Sociedad Argentina de Investigación Odontológica.

ECX and PEX rheology. Progress report, October--December 1975

DOE Office of Scientific and Technical Information (OSTI.GOV)

West, G.T.

1975-01-01

The objectives of this project are: (1) to evaluate the capillary rheometer as a device to qualitatively measure the extrusion properties of extrusion cast and paste explosives; (2) to study and determine means to distinguish and characterize the rheological properties of different lots of ECX and PEX; and (3) to apply results from (1) and (2) to production loading operations involving ECX and PEX. The second objective (to study and determine means to distinguish and characterize rheological properties) of this project has been accomplished. Testing procedures were finalized, and general knowledge of the rheometer itself was gained. Three batches ofmore » 85/15 (wt. percent) RDX/Sylgard were tested in the Instron Capillary Rheometer. Each lot was statistically distinguishable from the other two lots. One lot exhibited a significantly lower apparent viscosity than the other two lots, which were statistically different from each other, but which were in fairly close agreement.« less

Free water determines diffusion alterations and clinical status in cerebral small vessel disease.

PubMed

Duering, Marco; Finsterwalder, Sofia; Baykara, Ebru; Tuladhar, Anil Man; Gesierich, Benno; Konieczny, Marek J; Malik, Rainer; Franzmeier, Nicolai; Ewers, Michael; Jouvent, Eric; Biessels, Geert Jan; Schmidt, Reinhold; de Leeuw, Frank-Erik; Pasternak, Ofer; Dichgans, Martin

2018-06-01

Diffusion tensor imaging detects early tissue alterations in Alzheimer's disease and cerebral small vessel disease (SVD). However, the origin of diffusion alterations in SVD is largely unknown. To gain further insight, we applied free water (FW) imaging to patients with genetically defined SVD (Cerebral Autosomal Dominant Arteriopathy with Subcortical Infarcts and Leukoencephalopathy [CADASIL], n = 57), sporadic SVD (n = 444), and healthy controls (n = 28). We modeled freely diffusing water in the extracellular space (FW) and measures reflecting fiber structure (tissue compartment). We tested associations between these measures and clinical status (processing speed and disability). Diffusion alterations in SVD were mostly driven by increased FW and less by tissue compartment alterations. Among imaging markers, FW showed the strongest association with clinical status (R 2 up to 34%, P < .0001). Findings were consistent across patients with CADASIL and sporadic SVD. Diffusion alterations and clinical status in SVD are largely determined by extracellular fluid increase rather than alterations of white matter fiber organization. Copyright © 2018 the Alzheimer's Association. All rights reserved.

Assessment of diffusion tensor image quality across sites and vendors using the American College of Radiology head phantom.

PubMed

Wang, Zhiyue J; Seo, Youngseob; Babcock, Evelyn; Huang, Hao; Bluml, Stefan; Wisnowski, Jessica; Holshouser, Barbara; Panigrahy, Ashok; Shaw, Dennis W W; Altman, Nolan; McColl, Roderick W; Rollins, Nancy K

2016-05-08

The purpose of this study was to explore the feasibility of assessing quality of diffusion tensor imaging (DTI) from multiple sites and vendors using American College of Radiology (ACR) phantom. Participating sites (Siemens (n = 2), GE (n= 2), and Philips (n = 4)) reached consensus on parameters for DTI and used the widely available ACR phantom. Tensor data were processed at one site. B0 and eddy current distortions were assessed using grid line displacement on phantom Slice 5; signal-to-noise ratio (SNR) was measured at the center and periphery of the b = 0 image; fractional anisotropy (FA) and mean diffusivity (MD) were assessed using phantom Slice 7. Variations of acquisition parameters and deviations from specified sequence parameters were recorded. Nonlinear grid line distortion was higher with linear shimming and could be corrected using the 2nd order shimming. Following image registration, eddy current distortion was consistently smaller than acquisi-tion voxel size. SNR was consistently higher in the image periphery than center by a factor of 1.3-2.0. ROI-based FA ranged from 0.007 to 0.024. ROI-based MD ranged from 1.90 × 10-3 to 2.33 × 10-3 mm2/s (median = 2.04 × 10-3 mm2/s). Two sites had image void artifacts. The ACR phantom can be used to compare key qual-ity measures of diffusion images acquired from multiple vendors at multiple sites.

An improved CCA-secure conditional proxy re-encryption without pairings

NASA Astrophysics Data System (ADS)

Chang, Yanni; He, Mingxing; Li, Xiao; Xing, Pengfei

2014-10-01

In order to solve fine-grained delegation, the definition of conditional proxy re-encryption was proposed and soon draws a lot of attention in recent years. All of the existing schemes except one are based on bilinear pairings, which computation is costly. We point out that the only one existing conditional proxy re-encryption scheme without pairings can not solve fine-grained delegation essentially. Then we propose a new property of conditional proxy re-encryption scheme, that is non-diffusibility, that means if the proxy with a re-encryption key under one condition conclude with delegatee, they can obtain the re-encryption keys under any other conditions. We also propose a concrete CCA-secure conditional proxy re-encryption scheme without pairings. To the best of our knowledge, this is the first CCA-secure conditional proxy re-encryption scheme without pairings, which satisfies the non-diffusibility property.

Tularemia vaccine: Safety, reactogenicity, "Take" skin reactions, and antibody responses following vaccination with a new lot of the Francisella tularensis live vaccine strain - A phase 2 randomized clinical Trial.

PubMed

Mulligan, Mark J; Stapleton, Jack T; Keitel, Wendy A; Frey, Sharon E; Chen, Wilbur H; Rouphael, Nadine; Edupuganti, Srilatha; Beck, Allison; Winokur, Patricia L; El Sahly, Hana M; Patel, Shital M; Atmar, Robert L; Graham, Irene; Anderson, Edwin; El-Kamary, Samer S; Pasetti, Marcela F; Sztein, Marcelo B; Hill, Heather; Goll, Johannes B

2017-08-24

Tularemia is caused by Francisella tularensis, a gram-negative bacterium that has been weaponized as an aerosol. For protection of personnel conducting biodefense research, the United States Army required clinical evaluation of a new lot of tularemia live vaccine strain manufactured in accordance with Current Good Manufacturing Practices. A phase 2 randomized clinical trial compared the new lot (DVC-LVS) to the existing vaccine that has been in use for decades (USAMRIID-LVS). The vaccines were delivered by scarification to 228 participants. Safety, reactogenicity, take and/or antibody levels were assessed on days 0, 1, 2, 8, 14, 28, 56, and 180. Both vaccines were safe and had acceptable reactogenicity profiles during six months of follow-up. There were no serious or grade 3 and 4 laboratory adverse events. Moderate systemic reactogenicity (mostly headache or feeling tired) was reported by ∼23% of participants receiving either vaccine. Injection site reactogenicity was mostly mild itchiness and pain. The frequencies of vaccine take skin reactions were 73% (95% CI, 64, 81) for DVC-LVS and 80% (95% CI, 71, 87) for USAMRIID-LVS. The 90% CI for the difference in proportions was -6.9% (-16.4, 2.6). The rates of seroconversion measured by microagglutination assay on days 28 or 56 were 94% (95% CI, 88, 98; n=98/104) for DVC-LVS and 94% (95% CI, 87, 97; n=103/110) for USAMRIID-LVS (p=1.00). Day 14 sera revealed more rapid seroconversion for DVC-LVS relative to USAMRIID-LVS: 82% (95% CI, 73, 89) versus 55% (95% CI, 45, 65), respectively (p<0.0001). The DVC-LVS vaccine had similar safety, reactogenicity, take and antibody responses compared to the older USAMRIID vaccine, and was superior for early (day 14) antibody production. Vaccination take was not a sensitive surrogate for seroconversion in a multi-center study where personnel at five research clinics performed assessments. ClinicalTrials.gov identifier NCT01150695. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Collision cross sections and transport coefficients of O-, O2 -, O3 - and O4 - negative ions in O2, N2 and dry air for non-thermal plasmas modelling

NASA Astrophysics Data System (ADS)

Hennad, Ali; Yousfi, Mohammed

2018-02-01

The ions interaction data such as interaction potential parameters, elastic and inelastic collision cross sections and the transport coefficients (reduced mobility and diffusion coefficients) have been determined and analyzed in the case of the main negative oxygen ions (O-, O2 -, O3 - and O4 -) present in low temperature plasma at atmospheric pressure when colliding O2, N2 and dry air. The ion transport has been determined from an optimized Monte Carlo simulation using calculated elastic and experimentally fitted inelastic collision cross sections. The elastic momentum transfer collision cross sections have been calculated from a semi-classical JWKB approximation based on a ( n-4) rigid core interaction potential model. The cross sections sets involving elastic and inelastic processes were then validated using measured reduced mobility data and also diffusion coefficient whenever available in the literature. From the sets of elastic and inelastic collision cross sections thus obtained for the first time for O3-/O2, O2 -/N2, O3 -/N2, and O4 -/N2 systems, the ion transport coefficients were calculated in pure gases and dry air over a wide range of the density reduced electric field E/N.

Comparative analyses of industrial-scale human platelet lysate preparations.

PubMed

Pierce, Jan; Benedetti, Eric; Preslar, Amber; Jacobson, Pam; Jin, Ping; Stroncek, David F; Reems, Jo-Anna

2017-12-01

Efforts are underway to eliminate fetal bovine serum from mammalian cell cultures for clinical use. An emerging, viable replacement option for fetal bovine serum is human platelet lysate (PL) as either a plasma-based or serum-based product. Nine industrial-scale, serum-based PL manufacturing runs (i.e., lots) were performed, consisting of an average ± standard deviation volume of 24.6 ± 2.2 liters of pooled, platelet-rich plasma units that were obtained from apheresis donors. Manufactured lots were compared by evaluating various biochemical and functional test results. Comprehensive cytokine profiles of PL lots and product stability tests were performed. Global gene expression profiles of mesenchymal stromal cells (MSCs) cultured with plasma-based or serum-based PL were compared to MSCs cultured with fetal bovine serum. Electrolyte and protein levels were relatively consistent among all serum-based PL lots, with only slight variations in glucose and calcium levels. All nine lots were as good as or better than fetal bovine serum in expanding MSCs. Serum-based PL stored at -80°C remained stable over 2 years. Quantitative cytokine arrays showed similarities as well as dissimilarities in the proteins present in serum-based PL. Greater differences in MSC gene expression profiles were attributable to the starting cell source rather than with the use of either PL or fetal bovine serum as a culture supplement. Using a large-scale, standardized method, lot-to-lot variations were noted for industrial-scale preparations of serum-based PL products. However, all lots performed as well as or better than fetal bovine serum in supporting MSC growth. Together, these data indicate that off-the-shelf PL is a feasible substitute for fetal bovine serum in MSC cultures. © 2017 AABB.

Lot-to-lot consistency of live attenuated SA 14-14-2 Japanese encephalitis vaccine manufactured in a good manufacturing practice facility and non-inferiority with respect to an earlier product.

PubMed

Zaman, K; Naser, Abu Mohd; Power, Maureen; Yaich, Mansour; Zhang, Lei; Ginsburg, Amy Sarah; Luby, Stephen P; Rahman, Mahmudur; Hills, Susan; Bhardwaj, Mukesh; Flores, Jorge

2014-10-21

We conducted a four-arm, double-blind, randomized controlled trial among 818 Bangladeshi infants between 10 and 12 months of age to establish equivalence among three lots of live attenuated SA 14-14-2 JE vaccine manufactured by the China National Biotec Group's Chengdu Institute of Biological Products (CDIBP) in a new Good Manufacturing Practice (GMP) facility and to evaluate non-inferiority of the product with a lot of the same vaccine manufactured in CDIBP's original facility. The study took place in two sites in Bangladesh, rural Matlab and Mirpur in urban Dhaka. We collected pre-vaccination (Day 0) and post-vaccination Day 28 (-4 to +14 days) blood samples to assess neutralizing anti-JE virus antibody titers in serum by plaque reduction neutralization tests (PRNT). Seroprotection following vaccination was defined as a PRNT titer ≥1:10 at Day 28 in participants non-immune at baseline. Follow-up for reactogenicity and safety was conducted through home visits at Day 7 and monitoring for serious adverse events through Day 28. Seroprotection rates ranged from 80.2% to 86.3% for all four lots of vaccine. Equivalence of the seroprotection rates between pairs of vaccine lots produced in the new GMP facility was satisfied at the pre-specified 10% margin of the 95% confidence interval (CI) for two of the three pairwise comparisons, but not for the third (-4.3% observed difference with 95% CI of -11.9 to 3.3%). Nevertheless, the aggregate seroprotection rate for all three vaccine lots manufactured in the GMP facility was calculated and found to be within the non-inferiority margin (within 10%) to the vaccine lot produced in the original facility. All four lots of vaccine were safe and well tolerated. These study results should facilitate the use of SA 14-14-2 JE vaccine as a routine component of immunization programs in Asian countries. Copyright © 2014 Elsevier Ltd. All rights reserved.

Warranties for Weapons: Theory and Initial Assessment.

DTIC Science & Technology

1987-04-01

the warranty on the C-17 air vehicle.2 This warranty calls for the field measurement of some five maintainability parameters, redesign and retrofit of...NOTE N-2479-AF Warranties for Weapons: Theory and Initial Assessment James P. Stucker, Giles K. Smith April 1987 Prepared for The United States Air Force...cost, schedule, performance, and reliability? The Air Force and the other Services currently are spending a lot of money and effort specifying

[Friedreich's disease in the department of neurology in Dakar].

PubMed

Ndiaye, M; Ndao, A K; Sene-Diouf, F; Diop, A G; Diagne, M; Thiam, A; Ndiaye, M M; Ndiaye, I P

2000-01-01

A retrospective study of Friedreich's ataxia was conducted from january 1960 to december 1997. Eighten cases had been collected. Friedreich's ataxia was the second disorder after Pierre Marie's ataxia among inherited ataxia. Parental consanguinity has been found in 27.77% of cases. The sex-ratio was 2.6 for males. 66,67% of Friedreich's ataxia cases began after 25 years. Clinical signs were: cerebellar ataxia, sensitive disorders in 70%, pyramidal syndrom and cardiomyopathy in 22.22%, bones dysmorphy in 50% of cases. Electromyography indicated severe axonopathy of members with decreased somesthesic potentials in six cases. Glycaemia was normal in all cases. Clinical future presented wide variation between one and fourth years old.

Three Permeable Pavements Performances for Priority Metal Pollutants and Metals Associated with Deicing Chemicals from Edison Parking Lot, NJ

EPA Science Inventory

The U.S. Environmental Protection Agency constructed a 4000-m2 parking lot in Edison, New Jersey in 2009. The parking lot is surfaced with three permeable pavements [permeable interlocking concrete pavers (PICP), pervious concrete (PC), and porous asphalt (PA)]. Samples of each p...

Fundamental Aspects of Pressuremeter Testing.

DTIC Science & Technology

1987-04-30

consolidomreter is giveln ill Fig. 3.1. To reduce the consolidation time, drainage is provided at the top and botton , of the specimen. A detailed mechanical...OCf I. f,1 rr cal stait so, m~ode ~1, ThC ( ;1!1. ( Ia fl-- lot a! 9 an(.- tf. n’’.j" .. ( amn CIa, (ko-tem and 1Biriii. 1140% are it.o tt3’ (d i...plane strain tests, the intermediate principal stress is [ lot known unless the sides of the specinien corresponding to the plane of zero deform-a

MULTI-WAVELENGTH OBSERVATIONS OF THE SPATIO-TEMPORAL EVOLUTION OF SOLAR FLARES WITH AIA/SDO. I. UNIVERSAL SCALING LAWS OF SPACE AND TIME PARAMETERS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aschwanden, Markus J.; Zhang, Jie; Liu, Kai, E-mail: aschwanden@lmsal.com, E-mail: jzhang7@gmu.edu

2013-09-20

We extend a previous statistical solar flare study of 155 GOES M- and X-class flares observed with AIA/SDO to all seven coronal wavelengths (94, 131, 171, 193, 211, 304, and 335 Å) to test the wavelength dependence of scaling laws and statistical distributions. Except for the 171 and 193 Å wavelengths, which are affected by EUV dimming caused by coronal mass ejections (CMEs), we find near-identical size distributions of geometric (lengths L, flare areas A, volumes V, and fractal dimension D{sub 2}), temporal (flare durations T), and spatio-temporal parameters (diffusion coefficient κ, spreading exponent β, and maximum expansion velocities v{submore » max}) in different wavelengths, which are consistent with the universal predictions of the fractal-diffusive avalanche model of a slowly driven, self-organized criticality (FD-SOC) system, i.e., N(L)∝L {sup –3}, N(A)∝A {sup –2}, N(V)∝V {sup –5/3}, N(T)∝T {sup –2}, and D{sub 2} = 3/2, for a Euclidean dimension d = 3. Empirically, we find also a new strong correlation κ∝L {sup 0.94±0.01} and the three-parameter scaling law L∝κ T {sup 0.1}, which is more consistent with the logistic-growth model than with classical diffusion. The findings suggest long-range correlation lengths in the FD-SOC system that operate in the vicinity of a critical state, which could be used for predictions of individual extreme events. We find also that eruptive flares (with accompanying CMEs) have larger volumes V, longer flare durations T, higher EUV and soft X-ray fluxes, and somewhat larger diffusion coefficients κ than confined flares (without CMEs)« less

Mathematical analysis of the Photovoltage Decay (PVD) method for minority carrier lifetime measurements

NASA Technical Reports Server (NTRS)

Vonroos, O. H.

1982-01-01

When the diffusion length of minority carriers becomes comparable with or larger than the thickness of a p-n junction solar cell, the characteristic decay of the photon-generated voltage results from a mixture of contributions with different time constants. The minority carrier recombination lifetime tau and the time constant l(2)/D, where l is essentially the thickness of the cell and D the minority carrier diffusion length, determine the signal as a function of time. It is shown that for ordinary solar cells (n(+)-p junctions), particularly when the diffusion length L of the minority carriers is larger than the cell thickness l, the excess carrier density decays according to exp (-t/tau-pi(2)Dt/4l(2)), tau being the lifetime. Therefore, tau can be readily determined by the photovoltage decay method once D and L are known.

Application of pulsed field gradient NMR techniques for investigating binding of flavor compounds to macromolecules.

PubMed

Jung, Da-Mi; De Ropp, Jeffrey S; Ebeler, Susan E

2002-07-17

Two diffusion-based NMR techniques are presented and used to investigate the binding of selected flavor compounds to macromolecules. A pulsed field gradient NMR (PFG-NMR) method was applied to measure the apparent diffusion coefficients of four alkanone compounds as they associated with bovine serum albumin (BSA). The change in the apparent diffusion coefficient as a function of the BSA/alkanone ratio was fitted to yield binding constants (K(a)()) and binding stoichiometry (n) for each alkanone. The results showed that the apparent diffusion coefficients of alkanones increased with a decrease in the BSA/alkanone ratios, and the measured values of K(a)() and n were comparable with those obtained with other methods and depended on the alkanone structure. A diffusion-based nuclear Overhauser effect (called diffusion NOE pumping) method was also applied to screen mixtures of flavor compounds and identify those that have a binding affinity to complex macromolecules. Using this technique benzaldehyde and vanillin were observed to bind with bovine serum albumin, whereas 2-phenylethanol was identified as a nonbinding or weakly binding ligand with BSA. The diffusion NOE pumping method was also applied to a hydro alcoholic solution of cacao bean tannin extracts to which a mixture of ethylbenzoate, benzaldehyde, and 2-phenylethanol was added. The diffusion NOE pumping technique clearly indicated that ethylbenzoate had a stronger binding affinity to the polymeric (-)-epicatechin units of the cacao bean tannin extracts than the other two flavor compounds. The results successfully demonstrate the potential applications of diffusion-based NMR techniques for studying flavors and nonvolatile food matrix interactions.

Correlation between apparent diffusion coefficient value on diffusion-weighted MR imaging and Gleason score in prostate cancer.

PubMed

Wu, X; Reinikainen, P; Vanhanen, A; Kapanen, M; Vierikko, T; Ryymin, P; Hyödynmaa, S; Kellokumpu-Lehtinen, P-L

2017-01-01

To investigate whether diffusion-weighted imaging (DWI) apparent diffusion coefficient (ADC) correlates with prostate cancer aggressiveness and further to compare the diagnostic performance of ADC and normalized ADC (nADC: normalized to non-tumor tissue). Thirty pre-treatment patients (mean age, 69years; range: 59-78years) with prostate cancer underwent magnetic resonance imaging (MRI) examination, including DWI with three b values: 50, 400, and 800s/mm 2 . Both ADC and nADC were correlated with the Gleason score obtained through transrectal ultrasound-guided biopsy. The tumor minimum ADC (ADC min : the lowest ADC value within tumor) had an inverse correlation with the Gleason score (r=-0.43, P<0.05), and it was lower in patients with Gleason score 3+4 than in those with Gleason score 3+3 (0.54±0.11×10 3 mm 2 /s vs. 0.64±0.12×10 -3 mm 2 /s, P<0.05). Both the nADC min and nADC mean correlated with the Gleason score (r=-0.52 and r=-0.55, P<0.01; respectively), and they were lower in patients with Gleason score 3+4 than those with Gleason score 3+3 (P<0.01; respectively). Receiver operating characteristic (ROC) analysis showed that the area under the ROC curve was 0.765, 0.818, or 0.833 for the ADC min , nADC min , or nADC mean ; respectively, in differentiating between Gleason score 3+4 and 3+3 tumors. Tumor ADC min , nADC min , and nADC mean are useful markers to predict the aggressiveness of prostate cancer. Copyright © 2016 Éditions françaises de radiologie. Published by Elsevier Masson SAS. All rights reserved.

Fargo-Moorhead Urban Study. Water Supply Appendix. Volume 3. Phase 2, Attachment A: Geochemical Investigations of the Old Fargo Landfill.

DTIC Science & Technology

1985-05-01

2 nHOLIES 2"IROCK LOWER LIMIT Of WASTE CELL UNDERLYING LAKE CLAYS DETAIL OF OBSERVATION WELLS INSTALLED IN 1981. FIGURE 3 V11 N8uber Depth to Botton ...ma- ~53 NOIJVAZ*I3 46 U = S. 4 9 U S .9 U I U ~! 0 I C a I i 15 ii liii I I ii. I SI I I UOLLVMdI3UUd aI,- Jo SIssot a S S aI - - a - U a -1*~ aw ...saarckJp 50 PIer.,4M-------- Chemist 11-22 I~et,D o~kota Stat* Depar’tment of H.Wh Public HealWi L-3horators I Lot tjmoer! 83-01’ 4494 g -Date Colectect

Evaluation of diffusion models in breast cancer.

PubMed

Panek, Rafal; Borri, Marco; Orton, Matthew; O'Flynn, Elizabeth; Morgan, Veronica; Giles, Sharon L; deSouza, Nandita; Leach, Martin O; Schmidt, Maria A

2015-08-01

The purpose of this study is to investigate whether the microvascular pseudodiffusion effects resulting with non-monoexponential behavior are present in breast cancer, taking into account tumor spatial heterogeneity. Additionally, methodological factors affecting the signal in low and high diffusion-sensitizing gradient ranges were explored in phantom studies. The effect of eddy currents and accuracy of b-value determination using a multiple b-value diffusion-weighted MR imaging sequence were investigated in test objects. Diffusion model selection and noise were then investigated in volunteers (n = 5) and breast tumor patients (n = 21) using the Bayesian information criterion. 54.3% of lesion voxels were best fitted by a monoexponential, 26.2% by a stretched-exponential, and 19.5% by a biexponential intravoxel incoherent motion (IVIM) model. High correlation (0.92) was observed between diffusion coefficients calculated using mono- and stretched-exponential models and moderate (0.59) between monoexponential and IVIM (medians: 0.96/0.84/0.72 × 10(-3) mm(2)/s, respectively). Distortion due to eddy currents depended on the direction of the diffusion gradient and displacement varied between 1 and 6 mm for high b-value images. Shift in the apparent diffusion coefficient due to intrinsic field gradients was compensated for by averaging diffusion data obtained from opposite directions. Pseudodiffusion and intravoxel heterogeneity effects were not observed in approximately half of breast cancer and normal tissue voxels. This result indicates that stretched and IVIM models should be utilized in regional analysis rather than global tumor assessment. Cross terms between diffusion-sensitization gradients and other imaging or susceptibility-related gradients are relevant in clinical protocols, supporting the use of geometric averaging of diffusion-weighted images acquired with diffusion-sensitization gradients in opposite directions.

Using behavioral statistical physics to understand supply and demand

NASA Astrophysics Data System (ADS)

Farmer, Doyne

2007-03-01

We construct a quantitative theory for a proxy for supply and demand curves using methods that look and feel a lot like physics. Neoclassical economics postulates that supply and demand curves can be explained as the result of rational agents selfishly maximizing their utility, but this approach has had very little empirical success. We take quite a different approach, building supply and demand curves out of impulsive responses to not-quite-random trading fluctuations. Because of reasons of empirical measurability, as a good proxy for changes in supply and demand we study the aggregate price impact function R(V), giving the average logarithmic price change R as a function of the signed trading volume V. (If a trade vi is initiated by a buyer, it has a plus sign, and vice versa for sellers; the signed trading volume for a series of N successive trades is VN(t) = ∑i=t^i=t+N vi). We develop a ``zero-intelligence" null hypothesis that each trade vi gives an impulsive kick f(vi) to the price, so that the average return RN(t) = ∑i=t^i=t+N f(vi). Under the assumption that vi is IID, R(VN) has a characteristic concave shape, becoming linear in the limit as N ->∞. Under some circumstances this is universal for large N, in the sense that it is independent of the functional form of f. While this null hypothesis gives useful qualitative intuition, to make it quantitatively correct, one must add two additional elements: (1) The signs of vi are a long-memory process and (2) the return R is efficient, in the sense that it is not possible to make profits with a linear prediction of the signs of vi. Using data from the London Stock Exchange we demonstrate that this theory works well, predicting both the magnitude and shape of R(VN). We show that the fluctuations in R are very large and for some purposes more important than the average behavior. A computer model for the fluctuations suggests the existence of an equation of state relating the diffusion rate of prices to the flow of trading orders.

Lot-to-lot Consistency, Safety, Tolerability and Immunogenicity of an Investigational Hexavalent Vaccine in US Infants.

PubMed

Block, Stanley L; Klein, Nicola P; Sarpong, Kwabena; Russell, Stephen; Fling, John; Petrecz, Maria; Flores, Sheryl; Xu, Jin; Liu, Guanghan; Stek, Jon E; Foglia, Ginamarie; Lee, Andrew W

2017-02-01

This multicenter phase III study (NCT01340937) evaluated the consistency of immune responses to 3 separate lots of diphtheria-tetanus toxoids-acellular pertussis 5, inactivated poliovirus vaccine, Haemophilus influenzae type b, and hepatitis B (DTaP5-IPV-Hib-HepB), an investigational hexavalent vaccine (HV). Healthy infants were randomized (2:2:2:1) to receive HV or Pentacel (Control). Groups 1, 2 and 3 received HV at 2, 4 and 6 months, and Control at 15 months. Group 4 received Control at 2, 4, 6 and 15 months, plus Recombivax HB (HepB) at 2 and 6 months. Concomitant Prevnar 13 was given to all groups at 2, 4, 6 and 15 months; pentavalent rotavirus vaccine (RV5) was given to all groups at 2, 4 and 6 months. Blood specimens (3-5 mL) were collected immediately before administration of dose 1, postdose 3, immediately before toddler dose, and after toddler dose. Adverse events were recorded after each vaccination. The 3 manufacturing lots of HV induced consistent antibody responses to all antigens. Immunogenicity of HV was noninferior to Control for all antibodies, except for pertussis filamentous hemagglutinin geometric mean concentration postdose 3, and pertussis pertactin (PRN) geometric mean concentration after toddler dose. Postdose 3 immunogenicity of concomitantly administered Prevnar 13 was generally similar (except for serotype 6B) when given with HV or Control. Adverse events of HV were similar to Control, except for a higher rate of fever ≥38.0°C [49.2% vs. 35.4%, estimated difference 13.7% (8.4, 18.8)]. HV demonstrated lot-to-lot manufacturing consistency; safety and immunogenicity were comparable with the licensed vaccines. HV provides a new combination vaccine option within the US 2-month, 4-month and 6-month vaccine series.

Effect of nitrogen segregation on TED and loss of phosphorus in CZ-Si

NASA Astrophysics Data System (ADS)

Fujiwara, N.; Saito, K.; Nakabayashi, Y.; Osuman, H. I.; Toyonaga, K.; Matsumoto, S.; Sato, Y.

2002-01-01

Transient enhanced diffusion (TED) and dose loss (pile-up) are investigated for phosphorus-implanted samples covered with both oxide and nitride films. P ions were implanted into p-type (1 0 0) CZ-Si (dose 5×10 13 cm-3, 100 keV) through a chemical vapor deposition (CVD) Si 3N 4 film. For a half of samples, Si 3N 4 was etched off and SiO 2 films were grown by CVD. Both samples were annealed for 20-360 min at 700 °C. Diffusivity of P and the dose loss were estimated based on the secondary-ion mass spectrometry (SIMS) P profiles. Both Si/Si 3N 4 and Si/SiO 2 interfaces were investigated with transmission electron microscopy (TEM) and electron energy-loss spectroscopy (EELS). There is no significant difference in P diffusivity between the SiO 2 and Si 3N 4 films for the present annealing condition of 700 °C for 20-360 min. Regarding dose loss, a distinct different behavior was observed. In case of the SiO 2 cover film, amount of dose decreases with the annealing time. On the other hand, amount of dose decrease with annealing time up to 180 min, but is recovered for more than 180 min in case of the Si 3N 4 cover film. From TEM and EELS analyses, it is found that nitrogen segregates at the Si/Si 3N 4 interface, resulting in recovery of dose loss.

Beyond the Methanogenic Black-Box: Greenhouse Gas Fluxes (CO2, CH4, N2O) as Evidence for Wetlands as Dynamic Redox Systems

NASA Astrophysics Data System (ADS)

Mcnicol, G.; Knox, S. H.; Sturtevant, C. S.; Baldocchi, D. D.; Silver, W. L.

2015-12-01

Seminal wetland research in the 1990s demonstrated that annual methane (CH4) fluxes scaled positively with ecosystem production across distinctive wetlands globally. This relationship implies a model of flooded wetland ecosystems as 'methanogenic black-boxes'; poised at a low redox state, and tending to release a fixed fraction of incoming annual productivity as CH4. In contrast, recent studies have reported high ratios of carbon dioxide (CO2) to CH4 emissions, and are adding to a body of evidence suggesting wetlands can vary more widely in their redox state. To explore this apparent incongruence we used principles of redox thermodynamics and laboratory experiments to develop predictions of wetland greenhouse gas (GHG) fluxes under different redox regimes. We then used a field study to test the hypothesis that ecosystem seasonality in gross primary productivity (GPP) and temperature would drive changes in GHG emissions, mediated by a dynamic - as opposed to static - redox regime. We estimated wetland GHG emissions from an emergent marsh in the Sacramento Delta, CA from March 2014-2015. We measured CO2, CH4 and N2O emissions via diffusion and ebullition with manual sampling, and whole-ecosystem fluxes of CO2 and CH4 using eddy-covariance. Ebullition and diffusive CH4 fluxes were strongly seasonal, with minimum rates (0.86 and 0.35 mg C-CH­­4 m-2 yr-1, respectively) during winter, and maximum rates (1.3 and 1.8 g C-CH­­4 m-2 yr-1, respectively) during the summer growing season. In contrast, winter diffusive CO2 fluxes (494 g C-CO2 m-2 yr-1) and fall bubble CO2 concentrations (1.49%) were highest, despite being seasons of lower GPP, temperature, and CH4 flux. Further, diffusive and ebullition fluxes of N2O showed zero net flux only during spring and summer months, whereas the wetland was a significant source of N2O during winter (81.2 ± 24.4 mg N-N2O m-2 yr-1). These seasonal flux dynamics contradict a 'methanogenic black box' model of wetland redox, which predicts carbon limitation of, and concurrent maxima in, heterotrophic CO2 and CH4 emissions, and no significant N2O emissions. Rather these results suggest that wetlands can function as dynamic redox environments where GHG emission rate and composition varies predictably in time with seasonal changes in GPP and temperature.

SAPO-34 Membranes for N-2/CH4 separation: Preparation, characterization, separation performance and economic evaluation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, SG; Zong, ZW; Zhou, SJ

2015-08-01

SAPO-34 membranes were synthesized by several routes towards N-2/CH4 separation. Membrane synthesis parameters including water content in the gel, crystallization time, support pore size, and aluminum source were investigated. High performance N-2-selective membranes were obtained on 100-nm-pore alumina tubes by using Al(i-C3H7O)(3) as aluminum source with a crystallization time of 6 h. These membranes separated N-2 from CH, with N-2 permeance as high as 500 GPU with separation selectivity of 8 at 24 degrees C. for a 50/50 N-2/CH4 mixture. Nitrogen and CH, adsorption isotherms were measured on SAPO-34 crystals. The N-2 and CH, heats of adsorption were 11 andmore » 15 kJ/mol, respectively, which lead to a preferential adsorption of CE-H-4 over N-2 in the N-2/CH4 mixture. Despite this, the SAPO-34 membranes were selective for N-2 over CH4 in the mixture because N-2 diffuses much faster than CH4 and differences in diffusivity played a more critical role than the competitive adsorption. Preliminary economic evaluation indicates that the required N-2/CH4 selectivity would be 15 in order to maintain a CH4 loss below 10%. For small nitrogen-contaminated gas wells, our current SAPO-34 membranes have potential to compete with the benchmark technology cryogenic distillation for N-2 rejection. (C) 2015 Elsevier B.V. All rights reserved,« less

Influence of N2 annealing on TiO2 tubes structure and its photocatalytic activity

NASA Astrophysics Data System (ADS)

Chen, Xiaoxiang; Pan, Zhanchang; Yu, Ke; Xiao, Jun; Wu, Shoukun; Li, Jinghong; Chen, Chun; Lin, Yingsheng; Hu, Guanghui; Xu, Yanbin

2018-02-01

In this work, the TiO2 tubes (TBs) were prepared by solvothermal method. The morphology and phase structure of TiO2 TBs is significantly affected by N2 annealing temperature. XRD was used to characterize the phase structure of the as-prepared samples. The morphology and surface areas were characterized by SEM and N2 adsorption-desorption, which show that the tubes were assembled with about 100-nm nanosheets and small ball particles under 400 and 600 °C N2 annealing; when temperature reached 800 °C, the surface of tubes appeared a lot of collapse and many large holes. In addition, the surface areas of 400 °C TiO2, 600 °C TiO2, and 800 °C TiO2 TBs were significantly affected by N2 annealing. Most importantly, the UV-vis and electrochemical tests demonstrate 600 °C TiO2 TBs exhibit higher absorption intensity and photocurrent; thus, it possess on better photocatalytic activity. Therefore, the photocatalytic performance for TiO2 TBs is significantly co-affected by surface area and mix-phase. [Figure not available: see fulltext.

[Characterization and comparison of interferon reference standards using UPLC-MS].

PubMed

Tao, Lei; Pei, De-ning; Han, Chun-mei; Chen, Wei; Rao, Chun-ming; Wang, Jun-zhi

2015-01-01

The study aims to characterize and compare interferon reference standards from 5 manufacturers. By testing molecular mass and trypsin-digested peptide mass mapping, the amino acid sequence was verified and post-translational modifications such as disulfide bond were identified. Results show that the molecular mass and amino acid sequence were consistent with theory; the disulfide bonds of 4 lots of interferon were Cys1-Cys98/Cys29-Cys138, 1 lot was Cys29-Cys139/Cys86-Cys99; N-terminal "+Met", acetyl N-terminal and Met oxidation were identified in part of the sample. UPLC-MS can be used to characterize and compare interferon reference standards from different manufacturers.

Fabrication of porous carbon sphere@SnO2@carbon layer coating composite as high performance anode for sodium-ion batteries

NASA Astrophysics Data System (ADS)

Li, Xin; Sun, Xiaohong; Gao, Zhiwen; Hu, Xudong; Guo, Jingdong; Cai, Shu; Guo, Ruisong; Ji, Huiming; Zheng, Chunming; Hu, Wenbin

2018-03-01

SnO2 has triggered lots of research efforts as anode for sodium-ion batteries. However, the volume expansion and poor conductivity lead to an unsatisfactory electrochemical performance for the practical application of SnO2. In this work, a novel carbon-coated SnO2 supported by porous carbon sphere composite is synthesized by hydrothermal process combining with annealing method. The porous carbon sphere@SnO2@carbon layer coating composite anode delivers a reversible capacity of 326 mAh g-1 over 80 cycles at a current density of 50 mA g-1. Even at 1600 mA g-1, a capacity of 82 mAh g-1 is still maintained after 550 cycles. Such excellent performance can be ascribed to the unique structure, which efficiently accommodates volume expansion, enhances conductivity and offers shortened sodium-ion transport pathway. The charge-storage mechanisms can be comprised of diffusion-controlled reaction and pseudocapacitance effect. At high scan rate of 1.0 mV s-1, the capacity contribution of pseudocapacitance effect could reach as high as 78%.

Photovoltaic characteristics of diffused P/+N bulk GaAs solar cells

NASA Technical Reports Server (NTRS)

Borrego, J. M.; Keeney, R. P.; Bhat, I. B.; Bhat, K. N.; Sundaram, L. G.; Ghandhi, S. K.

1982-01-01

The photovoltaic characteristics of P(+)N junction solar cells fabricated on bulk GaAs by an open tube diffusion technique are described in this paper.Spectral response measurements were analyzed in detail and compared to a computer simulation in order to determine important material parameters. It is projected that proper optimization of the cell parameters can increase the efficiency of the cells from 12.2 percent to close to 20 percent.

Passivation of phosphorus diffused silicon surfaces with Al2O3: Influence of surface doping concentration and thermal activation treatments

NASA Astrophysics Data System (ADS)

Richter, Armin; Benick, Jan; Kimmerle, Achim; Hermle, Martin; Glunz, Stefan W.

2014-12-01

Thin layers of Al2O3 are well known for the excellent passivation of p-type c-Si surfaces including highly doped p+ emitters, due to a high density of fixed negative charges. Recent results indicate that Al2O3 can also provide a good passivation of certain phosphorus-diffused n+ c-Si surfaces. In this work, we studied the recombination at Al2O3 passivated n+ surfaces theoretically with device simulations and experimentally for Al2O3 deposited with atomic layer deposition. The simulation results indicate that there is a certain surface doping concentration, where the recombination is maximal due to depletion or weak inversion of the charge carriers at the c-Si/Al2O3 interface. This pronounced maximum was also observed experimentally for n+ surfaces passivated either with Al2O3 single layers or stacks of Al2O3 capped by SiNx, when activated with a low temperature anneal (425 °C). In contrast, for Al2O3/SiNx stacks activated with a short high-temperature firing process (800 °C) a significant lower surface recombination was observed for most n+ diffusion profiles without such a pronounced maximum. Based on experimentally determined interface properties and simulation results, we attribute this superior passivation quality after firing to a better chemical surface passivation, quantified by a lower interface defect density, in combination with a lower density of negative fixed charges. These experimental results reveal that Al2O3/SiNx stacks can provide not only excellent passivation on p+ surfaces but also on n+ surfaces for a wide range of surface doping concentrations when activated with short high-temperature treatments.

The influence of parental encouragement and caring about healthy eating on children's diet quality and body weights.

PubMed

Faught, Erin; Vander Ploeg, Kerry; Chu, Yen Li; Storey, Kate; Veugelers, Paul J

2016-04-01

In order to mitigate childhood obesity, evidence on what influences children's health behaviours is needed to inform new health promotion strategies. The present study investigated the association between parental practices and their child's diet and body weight status. Grade 5 students and their parents completed health surveys. Parents were asked how much they 'encourage their child to eat healthy foods' and how much they 'personally care about healthy eating'. Children's diet quality and vegetable and fruit intake were assessed using an FFQ. Children's heights and weights were measured to determine body weight status. Mixed-effects regression models were used to determine the influence of parental responses on the outcomes of interest. Elementary schools across the province of Alberta, Canada. Grade 5 students (aged 10 and 11 years; n 8388) and their parent(s). Most parents reported caring about healthy eating and encouraging their child to eat healthy foods at least quite a lot. Children whose parents who cared or encouraged 'very much' compared with 'quite a lot' were more likely have better diet quality and were less likely to be overweight. Children whose parents both cared and encouraged 'very much' compared with 'quite a lot' scored an average of 2·06 points higher on the diet quality index (β=2·06; 95 % CI 1·45, 2·66). Health promotion strategies that aim for a high level of parental interest and encouragement of their children to eat healthy foods may improve diet quality and prevent overweight among children.

Relationship between gaseous N dynamics and the hydraulic state of hierarchically structured soils

NASA Astrophysics Data System (ADS)

Schlüter, Steffen; Dörsch, Peter; Vogel, Hans-Jörg

2017-04-01

The inherent spatial heterogeneity of soil generates spatially distributed micro-sites with different local N gas (NO, N2O, N2) production and release rates. Moreover, local micro-site conditions and the pathways between them depend on soil moisture which itself is highly dynamic close to the soil surface. These relationships need to be taken into account for a quantitative understanding of soil denitrification and associated N gas dynamics. Soil structure has been recognized as a key factor to understand the high spatial variability of N gas emissions. In particular gaseous N release from soils depends on: i) the total denitrification rate, which is related to the spatial extent and distribution of anaerobic sites and ii) the probability of N2O to escape from the soil without being further reduced to N2. This impact of soil structure is typically ignored in studies with soil slurries or repacked soil. In this project we run well-defined mesocosm experiments on N gas dynamics with hierarchically structured, artificial soils in which the spatial distribution of substrate and denitrifiers is known exactly. Sintered, porous glass pellets are inoculated with strains of Paracoccus denitrificans and/or Agrobacterium tumefaciens and amended with nutrient solution. These pellets are embedded in coarse-grained sand within gas-tight columns under O2/He atmosphere. The pellets are either places in layers or randomly to create different patterns of N gas production sites and diffusion pathways. Denitrification occurs in the anaerobic centers of the porous pellets, while the partially saturated sand matrix controls the diffusive transport of N gases towards the headspace, where all relevant gas concentrations are monitored with gas chromatography. Water saturations are adjusted such that the diffusive pathways are either fully continuous or partially discontinuous. Preliminary results indicate that the water content exert a major control on the magnitude of denitrification, whereas the onset and dynamics are mainly controlled by the position of the substrate and the denitrifiers.

SIEST-A-RT: a study of vacancy diffusion in crystalline silicon using a local-basis first-principle (SIESTA) activation technique (ART).

NASA Astrophysics Data System (ADS)

El Mellouhi, Fedwa; Mousseau, Normand; Ordejón, Pablo

2003-03-01

We report on a first-principle study of vacancy-induced self-diffusion in crystalline silicon. Our simulations are performed on supercells containing 63 and 215 atoms. We generate the diffusion paths using the activation-relaxation technique (ART) [1], which can sample efficiently the energy landscape of complex systems. The forces and energy are evaluated using SIESTA [2], a selfconsistent density functional method using standard norm-conserving pseudopotentials and a flexible numerical linear combination of atomic orbitals basis set. Combining these two methods allows us to identify diffusion paths that would not be reachable with this degree of accuracy, using other methods. After a full relaxation of the neutral vacancy, we proceed to search for local diffusion paths. We identify various mechanisms like the formation of the four fold coordinated defect, and the recombination of dangling bonds by WWW process. The diffusion of the vacancy proceeds by hops to first nearest neighbor with an energy barrier of 0.69 eV. This work is funded in part by NSERC and NATEQ. NM is a Cottrell Scholar of the Research Corporation. [1] G. T. Barkema and N. Mousseau, Event-based relaxation of continuous disordered systems, Phys. Rev. Lett. 77, 4358 (1996); N. Mousseau and G. T. Barkema, Traveling through potential energy landscapes of disordered materials: ART, Phys. Rev. E 57, 2419 (1998). [2] Density functional method for very large systems with LCAO basis sets D. Sánchez-Portal, P. Ordejón, E. Artacho and J. M. Soler, Int. J. Quant. Chem. 65, 453 (1997).

Rotational diffusion of nondipolar and charged solutes in alkyl-substituted imidazolium triflimides: effect of C2 methylation on solute rotation.

PubMed

Prabhu, Sugosh R; Dutt, G B

2014-08-07

Rotational diffusion of a nondipolar solute 2,5-dimethyl-1,4-dioxo-3,6-diphenylpyrrolo[3,4-c]pyrrole (DMDPP) and a charged solute rhodamine 110 (R110) has been investigated in 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([BMIM][Tf2N]) and 1-butyl-2,3-dimethylimidazolium bis(trifluoromethylsulfonyl)imide ([BMMIM][Tf2N]) to understand the influence of the C2 methylation on solute rotation. The measured reorientation times of the nondipolar solute DMDPP are similar in both the ionic liquids and follow Stokes-Einstein-Debye hydrodynamic theory with slip hydrodynamics. In contrast, rotational diffusion of the charged solute R110 in [BMIM][Tf2N] obeys stick hydrodynamics due to specific interactions with the anion of the ionic liquid. Nevertheless, the intriguing result of this study is that the reorientation times of R110 in [BMMIM][Tf2N] deviate significantly from the predictions of stick hydrodynamics, especially at ambient temperatures. The solute-solvent boundary condition parameter Cobs, which is defined as the ratio of the measured reorientation time to the one calculated using the SED theory with stick boundary condition, for R110 is lower by a factor of 2 in [BMMIM][Tf2N] compared to [BMIM][Tf2N] at 298 K. Upon increasing the temperature, Cobs gradually increases and eventually matches with that obtained in [BMIM][Tf2N] at 348 K. It has been well established that methylation of the C2 position in [BMMIM][Tf2N] switches off the main hydrogen-bonding interaction between the anion and the cation, but increases the Coulombic interactions. As a consequence of the enhanced interionic interactions between the cation and anion of the ionic liquid, specific interactions between R110 and [Tf2N] diminish leading to the faster rotation of the solute. However, such an influence is not apparent in case of DMDPP as it does not experience specific interactions with either the cation or the anion of these ionic liquids.

Enhanced visible light photocatalytic H2-production of g-C3N4/WS2 composite heterostructures

NASA Astrophysics Data System (ADS)

Akple, Maxwell Selase; Low, Jingxiang; Wageh, S.; Al-Ghamdi, Ahmed. A.; Yu, Jiaguo; Zhang, Jun

2015-12-01

As a clean and renewable solar H2-production system to address the increasing global environmental crisis and energy demand, photocatalytic hydrogen production from water splitting using earth abundant materials has received a lot of attention. In this study, WS2-graphitic carbon nitride (g-C3N4) composites were prepared using WO3 and thiourea as precursors through a gas-solid reaction. Different amount of WS2 were loaded on g-C3N4 to form the heterostructures and the composite samples exhibited enhanced photocatalytic activity for H2 production under visible light. The composite sample with 0.01 wt% WS2 exhibited the highest H2-production rate of 101 μmol g-1 h-1, which was even better than that of the Pt-C3N4 sample with the same loading content. The high photocatalytic activity was attributed to the formation of heterojunction between g-C3N4 and WS2 cocatalyst which allowed for effective separation of photogenerated charge carriers. This work showed the possibility for the utilization of low cost WS2 as an efficient cocatalyst to promote the photocatalytic H2 production of g-C3N4.

Increased diffuse radiation fraction does not significantly accelerate plant growth

NASA Astrophysics Data System (ADS)

Angert, Alon; Krakauer, Nir

2010-05-01

A recent modelling study (Mercado et al., 2009) claims that increased numbers of scattering aerosols are responsible for a substantial fraction of the terrestrial carbon sink in recent decades because higher diffuse light fraction enhances plant net primary production (NPP). Here we show that observations of atmospheric CO2 seasonal cycle and tree ring data indicate that the relation between diffuse light and NPP is actually quite weak on annual timescales. The inconsistency of these data with the modelling results may arise because the relationships used to quantify the enhancement of NPP were calibrated with eddy covariance measurements of hourly carbon uptake. The effect of diffuse-light fraction on carbon uptake could depend on timescale, since this effect varies rapidly as sun angle and cloudiness change, and since plants can respond dynamically over various timescales to change in incoming radiation. Volcanic eruptions, such as the eruption of Mount Pinatubo in 1991, provide the best available tests for the effect of an annual-scale increase in the diffuse light fraction. Following the Pinatubo Eruption, in 1992 and 1993, a sharp decrease in the atmospheric CO2 growth rate was observed. This could have resulted from enhanced plant carbon uptake. Mercado et al. (2009) argue that largely as a result of the (volcanic aerosol driven) increase in diffuse light fraction, NPP was elevated in 1992, particularly between 25° N-45° N where annual NPP was modelled to be ~0.8 PgC (~10%) above average. In a previous study (Angert et al., 2004) a biogeochemical model (CASA) linked to an atmospheric tracer model (MATCH), was used to show that a diffuse-radiation driven increase in NPP in the extratropics will enhance carbon uptake mostly in summer, leading to a lower CO2 seasonal minimum. Here we use a 'toy model' to show that this conclusion is general and model-independent. The model shows that an enhanced sink of 0.8 PgC, similar to that modelled by Mercado et al. (2009), will result in a measurable decrease (~0.6ppm) in the seasonal CO2 minimum. This holds regardless of whether the sink is the result of 1) An increase in NPP, or 2) The combined effect of a temperature-driven decrease in heterotrophic respiration (Rh) and no change in NPP. This is since both NPP and Rh peak in summer. By contrast, observations from the NOAA global CO2 monitoring network show the opposite change in the seasonal minimum in 1992 and 1993 (~0.2ppm increase) both at Mauna Loa, and in the Marine Boundary Layer mean (>20° N), which is hard to reconcile with increased NPP in northern summer. Another indicator of annual NPP is tree wood increment. Previous work (Krakauer et al., 2003) showed that the average response in tree ring series after past Pinatubo-size volcanic eruptions implied lower NPP north of 45° N, presumably as a result of shorter growing season and lower total irradiance induced by scattering aerosols, and no significant change in NPP at lower latitudes. Here we show that In 1992, after the Pinatubo eruption, ring width in the 25° N-45° N band was 99.3±2.9% of average (n=351 sites), similar to the average of 100.4±2.2% over past eruptions (n=15 eruptions) (Uncertainty is given as 2 SE.). These results are also inconsistent with substantial NPP enhancement, although a limitation of the tree-ring approach is that available measurements do not uniformly sample the latitude band. The combined evidence of tree rings and the CO2 seasonal cycle shows that the enhancement of NPP by scattering aerosols on annual timescales is weak. This result suggests that reducing aerosols through stricter pollution controls may strengthen the land carbon sink, while geo-engineering schemes which aim to mitigate global warming by spreading scattering aerosols in the stratosphere may weaken it.

The effect of ethanol gas impurity on the discharge mode and discharge products of argon plasma jet at atmospheric pressure

NASA Astrophysics Data System (ADS)

Xia, Wenjie; Liu, Dingxin; Xu, Han; Wang, Xiaohua; Liu, Zhijie; Rong, Mingzhe; Kong, Michael G.

2018-05-01

Argon is a widely used working gas of plasmas, which is much cheaper than helium but on the other hand much more difficult to generate diffuse discharge at atmospheric pressure. In order to meet the application requirements, plenty of researches have been reported to facilitate the diffuse discharge happening for argon plasmas, and in this paper an approach of using ethanol gas (EtOH) impurity is investigated. The discharge characteristics of Ar + EtOH plasma jet are studied as a function of the applied voltage and the concentration of EtOH, from which the concentration of EtOH between ∼200 and ∼3300 parts per million (ppm) is determined necessary for the generation of diffuse discharge. Compared with the helium plasma jet in literature, it is deduced that the diffuse discharge is probably caused by the Penning ionization happening between the metastable argon and EtOH. The discharge products of Ar + EtOH (672 ppm) plasma jet are measured and the corresponding chemistry pathways are analyzed. About 20% of EtOH is decomposed via complex chemical reactions to form more than a dozen of neutral species, such as CH3CHO, CH3COOH, CO, H2O, and C n H2n+2 (n ≥ 3), and various kinds of ionic species, including C+, CH+, ArH+, {{{{O}}}2}-, CH3CH2O‑, etc.