Science.gov

Sample records for 10-4 mol dm-3

  1. Impact of 1 mmol dm(-3) concentrations of small molecules containing nitrogen-based cationic groups on the oxygen reduction reaction on polycrystalline platinum in aqueous KOH (1 mol dm(-3)).

    PubMed

    Ong, Ai Lien; Whelligan, Daniel K; Fox, Michael L; Varcoe, John R

    2013-11-21

    Alkaline anion-exchange membranes (AAEMs) containing cationic head-groups (e.g. involving quaternary ammonium and imidazolium groups) are of interest with regard to application in alkaline polymer electrolyte fuel cells (APEFCs). This initial ex situ study evaluated the effect of 1 mmol dm(-3) concentrations of model molecules containing (AAEM-relevant) cationic groups on the oxygen reduction reaction on a polycrystalline platinum disk (Ptpc) electrode in aqueous KOH (1 mol dm(-3)). The cationic molecules studied were tetramethylammonium (TMA), benzyltrimethylammonium (BTMA), 1-benzyl-3-methylimidazolium (BMI), 1-benzyl-4-aza-1-azoniabicyclo[2.2.2]octane (BAABCO) and 6-(benzyloxy)-N,N,N-trimethylhexan-1-aminium (BOTMHA). Both cyclic and hydrodynamic linear sweep rotating disk electrode voltammetry techniques were used. The resulting voltammograms, derived estimates of apparent electrochemically active surface areas, Tafel slopes, apparent exchange-current densities and the number of electrons transferred (per O2 molecule) were compared. The results strongly suggest that 1 mmol dm(-3) concentrations of BTMA, BAABCO, and (especially) BMI seriously inhibit the catalytic activities of Ptpc in an aqueous KOH electrolyte at 25 °C. The negative influence of (benzene-ring-free) TMA and Cl(-) anions (KCl control experiment) appeared to be less severe. The separation of the trimethylammonium group from the benzene ring via a hexyloxy spacer chain (in BOTMHA) also produced a milder negative effect. PMID:24100347

  2. Effect of cationic molecules on the oxygen reduction reaction on fuel cell grade Pt/C (20 wt%) catalyst in potassium hydroxide (aq, 1 mol dm(-3)).

    PubMed

    Ong, Ai Lien; Inglis, Kenneth K; Whelligan, Daniel K; Murphy, Sam; Varcoe, John R

    2015-05-14

    This study investigates the effect of 1 mmol dm(-3) concentrations of a selection of small cationic molecules on the performance of a fuel cell grade oxygen reduction reaction (ORR) catalyst (Johnson Matthey HiSPEC 3000, 20 mass% Pt/C) in aqueous KOH (1 mol dm(-3)). The cationic molecules studied include quaternary ammonium (including those based on bicyclic systems) and imidazolium types as well as a phosphonium example: these serve as fully solubilised models for the commonly encountered head-groups in alkaline anion-exchange membranes (AAEM) and anion-exchange ionomers (AEI) that are being developed for application in alkaline polymer electrolyte fuel cells (APEFCs), batteries and electrolysers. Both cyclic and hydrodynamic linear sweep rotating disk electrode voltammetry techniques were used. The resulting voltammograms and subsequently derived data (e.g. apparent electrochemical active surface areas, Tafel plots, and number of [reduction] electrons transferred per O2) were compared. The results show that the imidazolium examples produced the highest level of interference towards the ORR on the Pt/C catalyst under the experimental conditions used. PMID:25877304

  3. A Potentiometric, Spectrophotometric and Pitzer Ion-Interaction Study of Reaction Equilibria in the Aqueous H+-Al3+, H+-Oxalate and H+-Al3+-Oxalate Systems up to 5 mol*dm-3 NaCl

    SciTech Connect

    Boily, Jean F.; Qafoku, Odeta; Felmy, Andrew R.

    2007-12-01

    Aluminium-oxalate complexation was determined in acidic media of aqueous NaCl solutions ranging from 0.1-5.0 mol•dm-3. Complexation in the H+-Al3+ and H+-Oxalate systems was also studied to provide a set of internally consistent thermodynamic data. The ionic strength dependent formation constants describing the stabilities of the Al3+, AlOH2+, Al3(OH)45+, Al13O4(OH)247+, H2L, HL-, L2-, AlL+, AlL2- and AlL33- species (where L is the oxalate ion) was also described using a Pitzer ion interaction model. The derived parameters can be used to predict chemical speciation in the H+-Al3+-Oxalate system in the 0.1-5.0 mol•dm-3 NaCl range.

  4. Transcriptome analysis of Streptococcus pneumoniae treated with the designed antimicrobial peptides, DM3.

    PubMed

    Le, Cheng-Foh; Gudimella, Ranganath; Razali, Rozaimi; Manikam, Rishya; Sekaran, Shamala Devi

    2016-01-01

    In our previous studies, we generated a short 13 amino acid antimicrobial peptide (AMP), DM3, showing potent antipneumococcal activity in vitro and in vivo. Here we analyse the underlying mechanisms of action using Next-Generation transcriptome sequencing of penicillin (PEN)-resistant and PEN-susceptible pneumococci treated with DM3, PEN, and combination of DM3 and PEN (DM3PEN). DM3 induced differential expression in cell wall and cell membrane structural and transmembrane processes. Notably, DM3 altered the expression of competence-induction pathways by upregulating CelA, CelB, and CglA while downregulating Ccs16, ComF, and Ccs4 proteins. Capsular polysaccharide subunits were downregulated in DM3-treated cells, however, it was upregulated in PEN- and DM3PEN-treated groups. Additionally, DM3 altered the amino acids biosynthesis pathways, particularly targeting ribosomal rRNA subunits. Downregulation of cationic AMPs resistance pathway suggests that DM3 treatment could autoenhance pneumococci susceptibility to DM3. Gene enrichment analysis showed that unlike PEN and DM3PEN, DM3 treatment exerted no effect on DNA-binding RNA polymerase activity but observed downregulation of RpoD and RNA polymerase sigma factor. In contrast to DM3, DM3PEN altered the regulation of multiple purine/pyrimidine biosynthesis and metabolic pathways. Future studies based on in vitro experiments are proposed to investigate the key pathways leading to pneumococcal cell death caused by DM3. PMID:27225022

  5. Transcriptome analysis of Streptococcus pneumoniae treated with the designed antimicrobial peptides, DM3

    PubMed Central

    Le, Cheng-Foh; Gudimella, Ranganath; Razali, Rozaimi; Manikam, Rishya; Sekaran, Shamala Devi

    2016-01-01

    In our previous studies, we generated a short 13 amino acid antimicrobial peptide (AMP), DM3, showing potent antipneumococcal activity in vitro and in vivo. Here we analyse the underlying mechanisms of action using Next-Generation transcriptome sequencing of penicillin (PEN)-resistant and PEN-susceptible pneumococci treated with DM3, PEN, and combination of DM3 and PEN (DM3PEN). DM3 induced differential expression in cell wall and cell membrane structural and transmembrane processes. Notably, DM3 altered the expression of competence-induction pathways by upregulating CelA, CelB, and CglA while downregulating Ccs16, ComF, and Ccs4 proteins. Capsular polysaccharide subunits were downregulated in DM3-treated cells, however, it was upregulated in PEN- and DM3PEN-treated groups. Additionally, DM3 altered the amino acids biosynthesis pathways, particularly targeting ribosomal rRNA subunits. Downregulation of cationic AMPs resistance pathway suggests that DM3 treatment could autoenhance pneumococci susceptibility to DM3. Gene enrichment analysis showed that unlike PEN and DM3PEN, DM3 treatment exerted no effect on DNA-binding RNA polymerase activity but observed downregulation of RpoD and RNA polymerase sigma factor. In contrast to DM3, DM3PEN altered the regulation of multiple purine/pyrimidine biosynthesis and metabolic pathways. Future studies based on in vitro experiments are proposed to investigate the key pathways leading to pneumococcal cell death caused by DM3. PMID:27225022

  6. Vegetable-derived magnesium stearate functionality evaluation by DM(3) approach.

    PubMed

    Haware, Rahul V; Dave, Vivek S; Kakarala, Bhavyasri; Delaney, Sean; Staton, Scott; Munson, Eric; Gupta, Mali Ram; Stagner, William C

    2016-06-30

    This study quantifies the lubricating efficiency of two grades of crystalline vegetable-derived magnesium stearate (MgSt-V) using the DM(3) approach, which utilizes design of experiments (D) and multivariate analysis techniques (M3) to evaluate the effect of a material's (M1) molecular and macroscopic properties and manufacturing factors (M2) on critical product attributes. A 2(3) factorial design (2 continuous variables plus 1 categorical factor) with three center points for each categorical factor was used to evaluate the effect of MgSt-V fraction and blend time on running powder basic flow energy (BFE), tablet mechanical strength (TMS), disintegration time (DT), and running powder lubricant sensitivity ratio (LSR). Molecular characterization of MgSt-V employed moisture sorption-desorption analysis, (13)C nuclear magnetic resonance spectroscopy, thermal analysis, and powder X-ray diffraction. MgSt-V macroscopic analysis included mean particle size, specific surface area, particle morphology, and BFE. Principal component analysis and partial least squares multivariate analysis techniques were used to develop predictive qualitative and quantitative relationships between the molecular and macroscopic properties of MgSt-V grades, design variables, and resulting tablet formulation properties. MgSt-V fraction and blending time and their square effects showed statistical significant effects. Significant variation in the molecular and macroscopic properties of MgSt-V did not have a statistically significant impact on the studied product quality attributes (BFE, TMS, DT, and LSR). In setting excipient release specifications, functional testing may be appropriate in certain cases to assess the effect of statistically significant different molecular and macroscopic properties on product quality attributes. PMID:27108117

  7. 24 CFR 10.4 - Rules docket.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 24 Housing and Urban Development 1 2011-04-01 2011-04-01 false Rules docket. 10.4 Section 10.4... RULEMAKING: POLICY AND PROCEDURES General § 10.4 Rules docket. (a) All documents relating to rulemaking..., final rules and general notices are maintained in the Rules Docket Room (Room 5218), Department...

  8. 44 CFR 10.4 - Policy.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 44 Emergency Management and Assistance 1 2013-10-01 2013-10-01 false Policy. 10.4 Section 10.4 Emergency Management and Assistance FEDERAL EMERGENCY MANAGEMENT AGENCY, DEPARTMENT OF HOMELAND SECURITY GENERAL ENVIRONMENTAL CONSIDERATIONS General § 10.4 Policy. (a) FEMA shall act with care to assure that, in carrying out its...

  9. 44 CFR 10.4 - Policy.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 44 Emergency Management and Assistance 1 2014-10-01 2014-10-01 false Policy. 10.4 Section 10.4 Emergency Management and Assistance FEDERAL EMERGENCY MANAGEMENT AGENCY, DEPARTMENT OF HOMELAND SECURITY GENERAL ENVIRONMENTAL CONSIDERATIONS General § 10.4 Policy. (a) FEMA shall act with care to assure that, in carrying out its...

  10. 44 CFR 10.4 - Policy.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 44 Emergency Management and Assistance 1 2011-10-01 2011-10-01 false Policy. 10.4 Section 10.4 Emergency Management and Assistance FEDERAL EMERGENCY MANAGEMENT AGENCY, DEPARTMENT OF HOMELAND SECURITY GENERAL ENVIRONMENTAL CONSIDERATIONS General § 10.4 Policy. (a) FEMA shall act with care to assure that, in carrying out its...

  11. 44 CFR 10.4 - Policy.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 44 Emergency Management and Assistance 1 2012-10-01 2011-10-01 true Policy. 10.4 Section 10.4 Emergency Management and Assistance FEDERAL EMERGENCY MANAGEMENT AGENCY, DEPARTMENT OF HOMELAND SECURITY GENERAL ENVIRONMENTAL CONSIDERATIONS General § 10.4 Policy. (a) FEMA shall act with care to assure that, in carrying out its...

  12. 10 CFR 10.4 - Policy.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 1 2013-01-01 2013-01-01 false Policy. 10.4 Section 10.4 Energy NUCLEAR REGULATORY COMMISSION CRITERIA AND PROCEDURES FOR DETERMINING ELIGIBILITY FOR ACCESS TO RESTRICTED DATA OR NATIONAL SECURITY INFORMATION OR AN EMPLOYMENT CLEARANCE General Provisions § 10.4 Policy. It is the policy of the Nuclear Regulatory Commission to carry...

  13. 10 CFR 10.4 - Policy.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Policy. 10.4 Section 10.4 Energy NUCLEAR REGULATORY COMMISSION CRITERIA AND PROCEDURES FOR DETERMINING ELIGIBILITY FOR ACCESS TO RESTRICTED DATA OR NATIONAL SECURITY INFORMATION OR AN EMPLOYMENT CLEARANCE General Provisions § 10.4 Policy. It is the policy of the Nuclear Regulatory Commission to carry...

  14. 36 CFR 10.4 - Shipment.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 36 Parks, Forests, and Public Property 1 2011-07-01 2011-07-01 false Shipment. 10.4 Section 10.4... CERTAIN WILD ANIMALS § 10.4 Shipment. (a) Elk, buffaloes, and bears may be obtained at the Park and be... shipment in less than carload lots. Bears must be crated individually regardless of the number furnished...

  15. MolView users guide

    SciTech Connect

    Walenz, B.P.

    1996-06-01

    A system for viewing molecular data in a CAVE virtual reality environment is presented. The system, called MolView, consists of a frontend driver program that prepares the data and a backend CAVE program that displays the data. Both are written so that modifications and extensions are relatively easy to accomplish.

  16. 10 CFR 10.4 - Policy.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... Nuclear Regulatory Commission to carry out its responsibility for the security of the nuclear energy... 10 Energy 1 2014-01-01 2014-01-01 false Policy. 10.4 Section 10.4 Energy NUCLEAR REGULATORY COMMISSION CRITERIA AND PROCEDURES FOR DETERMINING ELIGIBILITY FOR ACCESS TO RESTRICTED DATA OR...

  17. 10 CFR 10.4 - Policy.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... Nuclear Regulatory Commission to carry out its responsibility for the security of the nuclear energy... 10 Energy 1 2011-01-01 2011-01-01 false Policy. 10.4 Section 10.4 Energy NUCLEAR REGULATORY COMMISSION CRITERIA AND PROCEDURES FOR DETERMINING ELIGIBILITY FOR ACCESS TO RESTRICTED DATA OR...

  18. 27 CFR 10.4 - Jurisdictional limits.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Jurisdictional limits. 10.4 Section 10.4 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU... direct effect of the inducement is to prevent, deter, hinder, or restrict other persons from selling...

  19. 36 CFR 10.4 - Shipment.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... CERTAIN WILD ANIMALS § 10.4 Shipment. (a) Elk, buffaloes, and bears may be obtained at the Park and be removed by truck. Elk and buffaloes, when not transported by truck, must be crated individually for...

  20. 43 CFR 10.4 - Inadvertent discoveries.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... National Historical Preservation Act (16 U.S.C. 470 (f) et seq.), 36 CFR 800.11 or section 3 (a) of the... Preservation Act (16 U.S.C. 470 (f) et seq.), 36 CFR 800.11 or section 3 (a) of the Archeological and Historic... 43 Public Lands: Interior 1 2012-10-01 2011-10-01 true Inadvertent discoveries. 10.4 Section...

  1. 17 CFR 10.4 - Business address; hours.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 17 Commodity and Securities Exchanges 1 2014-04-01 2014-04-01 false Business address; hours. 10.4 Section 10.4 Commodity and Securities Exchanges COMMODITY FUTURES TRADING COMMISSION RULES OF PRACTICE General Provisions § 10.4 Business address; hours. The Office of Proceedings is located at Three...

  2. 17 CFR 10.4 - Business address; hours.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 17 Commodity and Securities Exchanges 1 2012-04-01 2012-04-01 false Business address; hours. 10.4 Section 10.4 Commodity and Securities Exchanges COMMODITY FUTURES TRADING COMMISSION RULES OF PRACTICE General Provisions § 10.4 Business address; hours. The Office of Proceedings is located at Three...

  3. 17 CFR 10.4 - Business address; hours.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 17 Commodity and Securities Exchanges 1 2011-04-01 2011-04-01 false Business address; hours. 10.4 Section 10.4 Commodity and Securities Exchanges COMMODITY FUTURES TRADING COMMISSION RULES OF PRACTICE General Provisions § 10.4 Business address; hours. The Office of Proceedings is located at Three...

  4. 19 CFR 10.4 - Internal-revenue marks; erasure.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 19 Customs Duties 1 2014-04-01 2014-04-01 false Internal-revenue marks; erasure. 10.4 Section 10.4 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE... and Returned § 10.4 Internal-revenue marks; erasure. Internal-revenue brands or marks on casks...

  5. 19 CFR 10.4 - Internal-revenue marks; erasure.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 19 Customs Duties 1 2013-04-01 2013-04-01 false Internal-revenue marks; erasure. 10.4 Section 10.4 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE... and Returned § 10.4 Internal-revenue marks; erasure. Internal-revenue brands or marks on casks...

  6. 19 CFR 10.4 - Internal-revenue marks; erasure.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 19 Customs Duties 1 2011-04-01 2011-04-01 false Internal-revenue marks; erasure. 10.4 Section 10.4 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE... and Returned § 10.4 Internal-revenue marks; erasure. Internal-revenue brands or marks on casks...

  7. 19 CFR 10.4 - Internal-revenue marks; erasure.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 19 Customs Duties 1 2012-04-01 2012-04-01 false Internal-revenue marks; erasure. 10.4 Section 10.4 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE... and Returned § 10.4 Internal-revenue marks; erasure. Internal-revenue brands or marks on casks...

  8. 50 CFR 10.4 - When regulations apply.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 50 Wildlife and Fisheries 1 2010-10-01 2010-10-01 false When regulations apply. 10.4 Section 10.4... GENERAL PROVISIONS Introduction § 10.4 When regulations apply. The regulations of this subchapter B shall apply to all matters arising after the effective date of such regulations, with the following...

  9. 50 CFR 10.4 - When regulations apply.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 50 Wildlife and Fisheries 1 2011-10-01 2011-10-01 false When regulations apply. 10.4 Section 10.4... GENERAL PROVISIONS Introduction § 10.4 When regulations apply. The regulations of this subchapter B shall apply to all matters arising after the effective date of such regulations, with the following...

  10. 19 CFR 10.4 - Internal-revenue marks; erasure.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 19 Customs Duties 1 2010-04-01 2010-04-01 false Internal-revenue marks; erasure. 10.4 Section 10.4 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE... and Returned § 10.4 Internal-revenue marks; erasure. Internal-revenue brands or marks on casks...

  11. 40 CFR 10.4 - Evidence to be submitted.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 1 2014-07-01 2014-07-01 false Evidence to be submitted. 10.4 Section 10.4 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GENERAL ADMINISTRATIVE CLAIMS UNDER FEDERAL TORT CLAIMS ACT Procedures § 10.4 Evidence to be submitted. (a) Death. In support of a claim based on death, the claimant may be required...

  12. 39 CFR 10.4 - Financial disclosure reports.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 39 Postal Service 1 2012-07-01 2012-07-01 false Financial disclosure reports. 10.4 Section 10.4 Postal Service UNITED STATES POSTAL SERVICE THE BOARD OF GOVERNORS OF THE U.S. POSTAL SERVICE RULES OF CONDUCT FOR POSTAL SERVICE GOVERNORS (ARTICLE X) § 10.4 Financial disclosure reports. (a) Requirement of submission of reports. At the time of...

  13. 46 CFR 111.10-4 - Power requirements, generating sources.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 4 2013-10-01 2013-10-01 false Power requirements, generating sources. 111.10-4 Section 111.10-4 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING... services include cooking, heating, air conditioning (where installed), domestic refrigeration,...

  14. 46 CFR 111.10-4 - Power requirements, generating sources.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 4 2012-10-01 2012-10-01 false Power requirements, generating sources. 111.10-4 Section 111.10-4 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING... services include cooking, heating, air conditioning (where installed), domestic refrigeration,...

  15. 46 CFR 111.10-4 - Power requirements, generating sources.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 4 2014-10-01 2014-10-01 false Power requirements, generating sources. 111.10-4 Section 111.10-4 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING... services include cooking, heating, air conditioning (where installed), domestic refrigeration,...

  16. 46 CFR 111.10-4 - Power requirements, generating sources.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Power requirements, generating sources. 111.10-4 Section 111.10-4 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING... services include cooking, heating, air conditioning (where installed), domestic refrigeration,...

  17. 46 CFR 111.10-4 - Power requirements, generating sources.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 4 2011-10-01 2011-10-01 false Power requirements, generating sources. 111.10-4 Section 111.10-4 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING... services include cooking, heating, air conditioning (where installed), domestic refrigeration,...

  18. 39 CFR 10.4 - Financial disclosure reports.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... particular calendar year is required to file a public report in accordance with 5 CFR 2634.204(c). (b) Person... CONDUCT FOR POSTAL SERVICE GOVERNORS (ARTICLE X) § 10.4 Financial disclosure reports. (a) Requirement...

  19. International key comparison CCQM-K94: 10 μmol/mol dimethyl sulfide in nitrogen

    NASA Astrophysics Data System (ADS)

    Lee, S.; Heo, G. S.; Kim, Y.; Oh, S.; Han, Q.; Wu, H.; Konopelko, L. A.; Kustikov, Y. A.; Kolobova, A. V.; Efremova, O. V.; Pankratov, V. V.; Pavlov, M. V.; Culleton, L. P.; Brown, A. S.; Brookes, C.; Li, J.; Ziel, P. R.; van der Veen, A. M. H.

    2016-01-01

    Dimethyl sulfide (DMS) is an important compound in monitoring climate change and is monitored by the World Meteorological Organization Global Atmospheric Watch Volatile Organic Compounds (WMO-GAW VOC) program at several monitoring sites. It is essential that measurement results are accurate and consistent among the assigned values for primary gas mixtures to meet the WMO requirement. The purpose of this comparison is to compare the measurement capability of DMS at approximately 10 μ­mol/mol and expectation to contribute the establishment of traceability to single measurement scale for DMS between NMIs. Main text To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

  20. 39 CFR 10.4 - Financial disclosure reports.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... particular calendar year is required to file a public report in accordance with 5 CFR 2634.204(c). (b) Person... CONDUCT FOR POSTAL SERVICE GOVERNORS (ARTICLE X) § 10.4 Financial disclosure reports. (a) Requirement of... of their office for more than 60 days in any calendar year are not required to file...

  1. 39 CFR 10.4 - Financial disclosure reports.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... particular calendar year is required to file a public report in accordance with 5 CFR 2634.204(c). (b) Person... CONDUCT FOR POSTAL SERVICE GOVERNORS (ARTICLE X) § 10.4 Financial disclosure reports. (a) Requirement of... of their office for more than 60 days in any calendar year are not required to file...

  2. 39 CFR 10.4 - Financial disclosure reports.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... particular calendar year is required to file a public report in accordance with 5 CFR 2634.204(c). (b) Person... CONDUCT FOR POSTAL SERVICE GOVERNORS (ARTICLE X) § 10.4 Financial disclosure reports. (a) Requirement of... of their office for more than 60 days in any calendar year are not required to file...

  3. Optimized MOL-PCR for Characterization of Microbial Pathogens.

    PubMed

    Wuyts, Véronique; Roosens, Nancy H C; Bertrand, Sophie; Marchal, Kathleen; De Keersmaecker, Sigrid C J

    2016-01-01

    Characterization of microbial pathogens is necessary for surveillance, outbreak detection, and tracing of outbreak sources. This unit describes a multiplex oligonucleotide ligation-PCR (MOL-PCR) optimized for characterization of microbial pathogens. With MOL-PCR, different types of markers, like unique sequences, single-nucleotide polymorphisms (SNPs) and indels, can be simultaneously analyzed in one assay. This assay consists of a multiplex ligation for detection of the markers, a singleplex PCR for signal amplification, and hybridization to MagPlex-TAG beads for readout on a Luminex platform after fluorescent staining. The current protocol describes the MOL-PCR, as well as methods for DNA isolation, probe design, and data interpretation and it is based on an optimized MOL-PCR assay for subtyping of Salmonella Typhimurium. PMID:26742655

  4. MOL1 is required for cambium homeostasis in Arabidopsis.

    PubMed

    Gursanscky, Nial Rau; Jouannet, Virginie; Grünwald, Karin; Sanchez, Pablo; Laaber-Schwarz, Martina; Greb, Thomas

    2016-05-01

    Plants maintain pools of pluripotent stem cells which allow them to constantly produce new tissues and organs. Stem cell homeostasis in shoot and root tips depends on negative regulation by ligand-receptor pairs of the CLE peptide and leucine-rich repeat receptor-like kinase (LRR-RLK) families. However, regulation of the cambium, the stem cell niche required for lateral growth of shoots and roots, is poorly characterized. Here we show that the LRR-RLK MOL1 is necessary for cambium homeostasis in Arabidopsis thaliana. By employing promoter reporter lines, we reveal that MOL1 is active in a domain that is distinct from the domain of the positively acting CLE41/PXY signaling module. In particular, we show that MOL1 acts in an opposing manner to the CLE41/PXY module and that changing the domain or level of MOL1 expression both result in disturbed cambium organization. Underlining discrete roles of MOL1 and PXY, both LRR-RLKs are not able to replace each other when their expression domains are interchanged. Furthermore, MOL1 but not PXY is able to rescue CLV1 deficiency in the shoot apical meristem. By identifying genes mis-expressed in mol1 mutants, we demonstrate that MOL1 represses genes associated with stress-related ethylene and jasmonic acid hormone signaling pathways which have known roles in coordinating lateral growth of the Arabidopsis stem. Our findings provide evidence that common regulatory mechanisms in different plant stem cell niches are adapted to specific niche anatomies and emphasize the importance of a complex spatial organization of intercellular signaling cascades for a strictly bidirectional tissue production. PMID:26991973

  5. Comparison of primary standard gas mixtures: gravimetric production of carbon monoxide in nitrogen (3 μmol/mol)

    NASA Astrophysics Data System (ADS)

    Konopelko, L. A.; Kustikov, Y. A.; Kolobova, A. V.; Pankratov, V. V.; Pankov, A. A.; Efremova, O. V.; Augusto, Cristiane R.; Fioravante, Andreia L.; Ribeiro, Claudia C.; Teixeira, Denise C. G. S.; Elias, Elizandra C. S.; Oudwater, Rutger J.; Fagundes, Fátima A.; Silva, Marceli C.

    2016-01-01

    COOMET.QM-S3 is a supplementary comparison of primary standard gas mixtures—'Carbon monoxide in Nitrogen (3 μmol/mol)'. This is a bilateral comparison between VNIIM and INMETRO and it was conducted in 2013. Carbon monoxide is a toxic gas and in concentrations higher than 3-5 μmol/mol it is hazardous to human health. Therefore, it is important for NMIs to have the capability of an accurate carbon monoxide measurements. This comparison has shown that primary standard gas mixtures of carbon monoxide in nitrogen on the level of 3 μmol/mol, prepared in VNIIM and Inmetro, do not agree—the pair-wise degree of equivalence D (0.77%) is higher than the appropriate expanded uncertainty U(D) (0.29%). Main text To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

  6. 26 CFR 36.3121(l)(10)-4 - Payment of amounts equivalent to tax.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 26 Internal Revenue 15 2014-04-01 2014-04-01 false Payment of amounts equivalent to tax. 36.3121(l)(10)-4 Section 36.3121(l)(10)-4 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY... SUBSIDIARIES § 36.3121(l)(10)-4 Payment of amounts equivalent to tax. A domestic corporation which has...

  7. 26 CFR 36.3121(l)(10)-4 - Payment of amounts equivalent to tax.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 26 Internal Revenue 15 2011-04-01 2011-04-01 false Payment of amounts equivalent to tax. 36.3121(l)(10)-4 Section 36.3121(l)(10)-4 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY... SUBSIDIARIES § 36.3121(l)(10)-4 Payment of amounts equivalent to tax. A domestic corporation which has...

  8. 26 CFR 36.3121(l)(10)-4 - Payment of amounts equivalent to tax.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 15 2010-04-01 2010-04-01 false Payment of amounts equivalent to tax. 36.3121(l)(10)-4 Section 36.3121(l)(10)-4 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY... SUBSIDIARIES § 36.3121(l)(10)-4 Payment of amounts equivalent to tax. A domestic corporation which has...

  9. 26 CFR 36.3121(l)(10)-4 - Payment of amounts equivalent to tax.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 26 Internal Revenue 15 2012-04-01 2012-04-01 false Payment of amounts equivalent to tax. 36.3121(l)(10)-4 Section 36.3121(l)(10)-4 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY... SUBSIDIARIES § 36.3121(l)(10)-4 Payment of amounts equivalent to tax. A domestic corporation which has...

  10. 26 CFR 36.3121(l)(10)-4 - Payment of amounts equivalent to tax.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 26 Internal Revenue 15 2013-04-01 2013-04-01 false Payment of amounts equivalent to tax. 36.3121(l)(10)-4 Section 36.3121(l)(10)-4 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY... SUBSIDIARIES § 36.3121(l)(10)-4 Payment of amounts equivalent to tax. A domestic corporation which has...

  11. Crystal and mol-ecular structure of aflatrem.

    PubMed

    Lenta, Bruno N; Ngatchou, Jules; Kenfack, Patrice T; Neumann, Beate; Stammler, Hans-Georg; Sewald, Norbert

    2015-11-01

    The crystal structure of the title compound, C32H39NO4, confirms the absolute configuration of the seven chiral centres in the mol-ecule. The molecule has a 1,1-dimethylprop-2-enyl substituent on the indole nucleus and this nucleus shares one edge with the five-membered ring which is, in turn, connected to a sequence of three edge-shared fused rings. The skeleton is completed by the 7,7-trimethyl-6,8-dioxabi-cyclo-[3.2.1]oct-3-en-2-one group connected to the terminal cyclohexene ring. The two cyclohexane rings adopt chair and half-chair conformations, while in the dioxabi-cyclo-[3.2.1]oct-3-en-2-one unit, the six-membered ring has a half-chair conformation. The indole system of the mol-ecule exhibits a tilt of 2.02 (1)° between its two rings. In the crystal, O-H⋯O hydrogen bonds connect mol-ecules into chains along [010]. Weak N-H⋯π inter-actions connect these chains, forming sheets parallel to (10-1). PMID:26594569

  12. Crystal and mol­ecular structure of aflatrem

    PubMed Central

    Lenta, Bruno N.; Ngatchou, Jules; Kenfack, Patrice T.; Neumann, Beate; Stammler, Hans-Georg; Sewald, Norbert

    2015-01-01

    The crystal structure of the title compound, C32H39NO4, confirms the absolute configuration of the seven chiral centres in the mol­ecule. The molecule has a 1,1-dimethylprop-2-enyl substituent on the indole nucleus and this nucleus shares one edge with the five-membered ring which is, in turn, connected to a sequence of three edge-shared fused rings. The skeleton is completed by the 7,7-trimethyl-6,8-dioxabi­cyclo­[3.2.1]oct-3-en-2-one group connected to the terminal cyclohexene ring. The two cyclohexane rings adopt chair and half-chair conformations, while in the dioxabi­cyclo­[3.2.1]oct-3-en-2-one unit, the six-membered ring has a half-chair conformation. The indole system of the mol­ecule exhibits a tilt of 2.02 (1)° between its two rings. In the crystal, O—H⋯O hydrogen bonds connect mol­ecules into chains along [010]. Weak N—H⋯π inter­actions connect these chains, forming sheets parallel to (10-1). PMID:26594569

  13. Anthocyanins in berries of Maqui (Aristotelia chilensis (Mol.) Stuntz).

    PubMed

    Escribano-Bailón, María Teresa; Alcalde-Eon, Cristina; Muñoz, Orlando; Rivas-Gonzalo, Julián C; Santos-Buelga, Celestino

    2006-01-01

    The anthocyanin composition of berries of Maqui [Aristotelia chilensis (Mol.) Stuntz] was determined by HPLC with photodiode array and MS detection. Eight pigments corresponding to the 3-glucosides, 3,5-diglucosides, 3-sambubiosides and 3-sambubioside-5-glucosides of delphinidin and cyanidin were identified, the principal anthocyanin being delphinidin 3-sambubioside-5-glucoside (34% of total anthocyanins). The average total anthocyanin content was 137.6 +/- 0.4mg/100g of fresh fruit (211.9 +/- 0.6 mg/100g of dry fruit). The relative high anthocyanin content and the important presence of polar polyglycosylated derivatives makes the fruits of A. chilensis an interesting source of anthocyanin extracts for food and pharmaceutical uses. PMID:16454470

  14. 31 CFR 10.4 - Eligibility for enrollment as enrolled agent or enrolled retirement plan agent.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 31 Money and Finance: Treasury 1 2010-07-01 2010-07-01 false Eligibility for enrollment as enrolled agent or enrolled retirement plan agent. 10.4 Section 10.4 Money and Finance: Treasury Office of the Secretary of the Treasury PRACTICE BEFORE THE INTERNAL REVENUE SERVICE Rules Governing...

  15. 25 CFR 10.4 - What happens if the policies and standards are not followed?

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... not followed? The risk for human and civil rights violations due to lack of common standards will... followed? 10.4 Section 10.4 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAW AND ORDER... funding from potential resource sharing agreements with other law enforcement agencies may be...

  16. Designing and Construction of a DNA Vaccine Encoding Tb10.4 Gene of Mycobacterium tuberculosis

    PubMed Central

    Rashidian, Samira; Teimourpour, Roghayeh; Meshkat, Zahra

    2016-01-01

    Background: Tuberculosis (TB) remains as a major cause of death. Construction of a new vaccine against tuberculosis is an effective way to control it. Several vaccines against this disease have been developed. The aim of the present study was to cloning of tb10.4 gene in pcDNA3.1+ plasmid and evaluation of its expression in eukaryotic cells. Methods: Firstly, tb10.4 fragment was amplified by PCR and the PCR product was digested with restriction enzymes. Next, it was cloned into pcDNA3.1+ plasmid. Following that, pcDNA3.1+/tb10.4 recombinant plasmid was transfected into eukaryotic cells. Results: 5700 bp band for pcDNA3.1+/tb10.4 recombinant plasmid and 297 bp fragment for tb10.4 were observed. Cloning and transfection were successful. Conclusion: Successful cloning provides a basis for the development of new DNA vaccines against tuberculosis.

  17. Plasmids pMOL28 and pMOL30 of Cupriavidus metallidurans Are Specialized in the Maximal Viable Response to Heavy Metals▿ †

    PubMed Central

    Monchy, Sébastien; Benotmane, Mohammed A.; Janssen, Paul; Vallaeys, Tatiana; Taghavi, Safiyh; van der Lelie, Daniel; Mergeay, Max

    2007-01-01

    We fully annotated two large plasmids, pMOL28 (164 open reading frames [ORFs]; 171,459 bp) and pMOL30 (247 ORFs; 233,720 bp), in the genome of Cupriavidus metallidurans CH34. pMOL28 contains a backbone of maintenance and transfer genes resembling those found in plasmid pSym of C. taiwanensis and plasmid pHG1 of C. eutrophus, suggesting that they belong to a new class of plasmids. Genes involved in resistance to the heavy metals Co(II), Cr(VI), Hg(II), and Ni(II) are concentrated in a 34-kb region on pMOL28, and genes involved in resistance to Ag(I), Cd(II), Co(II), Cu(II), Hg(II), Pb(II), and Zn(II) occur in a 132-kb region on pMOL30. We identified three putative genomic islands containing metal resistance operons flanked by mobile genetic elements, one on pMOL28 and two on pMOL30. Transcriptomic analysis using quantitative PCR and microarrays revealed metal-mediated up-regulation of 83 genes on pMOL28 and 143 genes on pMOL30 that coded for all known heavy metal resistance proteins, some new heavy metal resistance proteins (czcJ, mmrQ, and pbrU), membrane proteins, truncated transposases, conjugative transfer proteins, and many unknown proteins. Five genes on each plasmid were down-regulated; for one of them, chrI localized on pMOL28, the down-regulation occurred in the presence of five cations. We observed multiple cross-responses (induction of specific metal resistance by other metals), suggesting that the cellular defense of C. metallidurans against heavy metal stress involves various regulons and probably has multiple stages, including a more general response and a more metal-specific response. PMID:17675385

  18. Deep Sub-micro mol{\\cdot }mol^{-1} Water-Vapor Measurement by Dual-Ball SAW Sensors for Temperature Compensation

    NASA Astrophysics Data System (ADS)

    Takeda, N.; Oizumi, T.; Tsuji, T.; Akao, S.; Takayanagi, K.; Nakaso, N.; Yamanaka, K.

    2015-12-01

    A collimated surface acoustic wave (SAW) circles around the equator of a sphere hundreds of times. Because of the long distance travel of the collimated SAW, a small change in the SAW propagation caused by the environment of the sphere can be accumulated as a measurable range in amplitude and/or in delay time. So, a spherical SAW device enables highly sensitive water-vapor measurements. In this paper, deep sub \\upmu mol{\\cdot }mol^{-1} water-vapor detection by 1 mm diameter quartz crystal ball SAW sensors is described. To measure such a low water-vapor concentration in real time, it is necessary to compensate the temperature dependence of the ball SAW sensor, which is about 20 ppm{\\cdot }°C^{-1} in delay time change. A dual-frequency burst analog detector was developed for the temperature compensation in real time. By using a harmonic SAW sensor, which was excited by 80 MHz and 240 MHz at the same time, it was confirmed that the delay time drift for a temperature range of 21.0°C ± 1.0°C became less than 0.05 ppm in delay time change. By using dual-ball SAW sensors (which included a 150 MHz sensor with a water-vapor sensitive layer and a 240 MHz sensor as a reference), water-vapor concentrations from 0.1 \\upmu mol{\\cdot }mol^{-1} to 5 \\upmu mol{\\cdot }mol^{-1} were successfully measured. It appears that the delay time change is proportional to the square root of the water-vapor concentration. The detection limit determined by the electrical noise of the system was estimated at 0.01 \\upmu mol{\\cdot }mol^{-1}.

  19. 41 CFR 302-10.4 - Are there any geographic limitations for transportation of a mobile home?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... limitations for transportation of a mobile home? 302-10.4 Section 302-10.4 Public Contracts and Property...-ALLOWANCES FOR TRANSPORTATION OF MOBILE HOMES AND BOATS USED AS A PRIMARY RESIDENCE Eligibility and Limitations § 302-10.4 Are there any geographic limitations for transportation of a mobile home?...

  20. 41 CFR 302-10.4 - Are there any geographic limitations for transportation of a mobile home?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... limitations for transportation of a mobile home? 302-10.4 Section 302-10.4 Public Contracts and Property...-ALLOWANCES FOR TRANSPORTATION OF MOBILE HOMES AND BOATS USED AS A PRIMARY RESIDENCE Eligibility and Limitations § 302-10.4 Are there any geographic limitations for transportation of a mobile home?...

  1. 10. 4TH FLOOR, HOTEL SOAP LINE No. 6 TO SOUTHWEST, ...

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

    10. 4TH FLOOR, HOTEL SOAP LINE No. 6 TO SOUTHWEST, WITH AUTOMATIC CUTTER (LEFT), PRESS (CENTER), AND WRAPPER (RIGHT); LARGE CHUTE AT CENTER FROM 5TH FLOOR BINS TO 3RD FLOOR SOAP MILLS; OVERHEAD AND FLOOR (LOWER RIGHT) FINISHED GOODS CONVEYORS TO G BLOCK (HAER NO. NJ-71-NN) - Colgate & Company Jersey City Plant, Building No. B-14, 54-58 Grand Street, Jersey City, Hudson County, NJ

  2. GridMol: a grid application for molecular modeling and visualization.

    PubMed

    Sun, Yanhua; Shen, Bin; Lu, Zhonghua; Jin, Zhong; Chi, Xuebin

    2008-02-01

    In this paper we present GridMol, an extensible tool for building a high performance computational chemistry platform in the grid environment. GridMol provides computational chemists one-stop service for molecular modeling, scientific computing and molecular information visualization. GridMol is not only a visualization and modeling tool but also simplifies control of remote Grid software that can access high performance computing resources. GridMol has been successfully integrated into China National Grid, the most powerful Chinese Grid Computing platform. In Section "Grid computing" of this paper, a computing example is given to show the availability and efficiency of GridMol. GridMol is coded using Java and Java3D for portability and cross-platform compatibility (Windows, Linux, MacOS X and UNIX). GridMol can run not only as a stand-alone application, but also as an applet through web browsers. In this paper, we will present the techniques for molecular visualization, molecular modeling and grid computing. GridMol is available free of charge under the GNU Public License (GPL) from our website: http://www.sccas.cn/~syh/GridMol/index.html. PMID:18231861

  3. HackaMol: An Object-Oriented Modern Perl Library for Molecular Hacking on Multiple Scales.

    PubMed

    Riccardi, Demian; Parks, Jerry M; Johs, Alexander; Smith, Jeremy C

    2015-04-27

    HackaMol is an open source, object-oriented toolkit written in Modern Perl that organizes atoms within molecules and provides chemically intuitive attributes and methods. The library consists of two components: HackaMol, the core that contains classes for storing and manipulating molecular information, and HackaMol::X, the extensions that use the core. The core is well-tested, well-documented, and easy to install across computational platforms. The goal of the extensions is to provide a more flexible space for researchers to develop and share new methods. In this application note, we provide a description of the core classes and two extensions: HackaMol::X::Calculator, an abstract calculator that uses code references to generalize interfaces with external programs, and HackaMol::X::Vina, a structured class that provides an interface with the AutoDock Vina docking program. PMID:25793330

  4. An Introduction to Using the Method of Levels (MOL) Therapy to Work with People Experiencing Psychosis.

    PubMed

    Tai, Sara J

    2016-01-01

    This paper provides a basic introduction to using method of levels (MOL) therapy with people experiencing psychosis. As MOL is a direct application of perceptual control theory (PCT), a brief overview of the three main theoretical principles of this theory--control, conflict, and reorganization will be outlined in relation to understanding psychosis. In particular, how these principles form the basis of problem conceptualisation and determine what an MOL therapist is required to do during therapy will be illustrated. A practical description of MOL will be given, using case examples and short excerpts of therapeutic interactions. Some direct contrasts will also be made with cognitive behaviour therapy for psychosis (CBTp) and psychodynamic approaches (PA) in order to help illustrate the theory and practice of MOL. PMID:27052610

  5. Financial services FY 1995 site support program plan WBS 6.10.4

    SciTech Connect

    Vodney, E.P.

    1994-09-01

    This is the signed Financial Service fiscal year 1995 Site Support Program Plan, Work Breakdown Structure 6.10.4, for the Hanford site. This plan is intended to enable the contractor to accomplish the following: ensure financial integrity in all Westinghouse Hanford Company (WHC) operation while supporting the programmatic activities of WHC, the US Department of Energy, Richland Operations Office, and other Hanford contractors; provide efficient and effective financial services, and value added audits and review that enable management to enhance future operational results.

  6. Fotoexcitación de Moléculas Pequeñas

    NASA Astrophysics Data System (ADS)

    González Díaz, P. F.

    El modelo estocástico no puede justificar la excitación multi-fotónica de moléculas pequeñas o muy simétricas. Basándonos en un escenario de interacción radiación-molécula cooperativo para la absorción de N-1 fotones IR por un sistema de N niveles, se especula que un posible mecanismo para la excitación no estocástica de moléculas pudiera ser la generación de procesos caóticos intra-moleculares.

  7. Stabilization of Polar Step Edges on Calcite (10.4) by the Adsorption of Congo Red.

    PubMed

    Momper, Rebecca; Nalbach, Martin; Lichtenstein, Karin; Bechstein, Ralf; Kühnle, Angelika

    2015-07-01

    In this work, we present the stabilization of polar step edges along the [010] direction of calcite (10.4) by the presence of a water-soluble organic molecule, namely Congo Red. While characteristic etch pits are observed on the surface in the absence of the additive, no etch pits can be found in the presence of the additive. Using atomic force microscopy, we can directly follow the restructuring of the surface. Upon addition of Congo Red, the charge-neutral step edges confining the characteristic etch pits vanish, while polar step edges along the [010] direction appear on the surface, which are entirely decorated by well-ordered molecular islands of the additive. After the restructuring has taken place, the surface exclusively exhibits these polar step edges. Our results give direct evidence of the fact that these polar step edges become thermodynamically favored when Congo Red is present. PMID:26053526

  8. A New CCD Camera at the Molėtai Observatory

    NASA Astrophysics Data System (ADS)

    Zdanavičius, J.; Zdanavičius, K.

    The results of the first testing of a new CCD camera of the Molėtai Observatory are given. The linearity and the flat field corrections of good accuracy are determined by using shifted star field exposures.

  9. 38 CFR 10.4 - Loss, destruction, or mutilation of adjusted service certificate while in possession of...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 1 2011-07-01 2011-07-01 false Loss, destruction, or mutilation of adjusted service certificate while in possession of Department of Veterans Affairs. 10.4... Adjusted Compensation; General § 10.4 Loss, destruction, or mutilation of adjusted service...

  10. 38 CFR 10.4 - Loss, destruction, or mutilation of adjusted service certificate while in possession of...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 1 2014-07-01 2014-07-01 false Loss, destruction, or mutilation of adjusted service certificate while in possession of Department of Veterans Affairs. 10.4... Adjusted Compensation; General § 10.4 Loss, destruction, or mutilation of adjusted service...

  11. 38 CFR 10.4 - Loss, destruction, or mutilation of adjusted service certificate while in possession of...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 1 2010-07-01 2010-07-01 false Loss, destruction, or mutilation of adjusted service certificate while in possession of Department of Veterans Affairs. 10.4... Adjusted Compensation; General § 10.4 Loss, destruction, or mutilation of adjusted service...

  12. 38 CFR 10.4 - Loss, destruction, or mutilation of adjusted service certificate while in possession of...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 1 2012-07-01 2012-07-01 false Loss, destruction, or mutilation of adjusted service certificate while in possession of Department of Veterans Affairs. 10.4... Adjusted Compensation; General § 10.4 Loss, destruction, or mutilation of adjusted service...

  13. 38 CFR 10.4 - Loss, destruction, or mutilation of adjusted service certificate while in possession of...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 1 2013-07-01 2013-07-01 false Loss, destruction, or mutilation of adjusted service certificate while in possession of Department of Veterans Affairs. 10.4... Adjusted Compensation; General § 10.4 Loss, destruction, or mutilation of adjusted service...

  14. 12 GHz Radio-Holographic Surface Measurements of the RRI 10.4~m Telescope

    NASA Astrophysics Data System (ADS)

    Balasubramanyam, R.; Venkatesh, S.; Raju, S. B.

    2009-09-01

    A modern Q-band low noise amplifier (LNA) front-end is being fitted to the 10.4~m millimeter-wave telescope at the Raman Research Institute (RRI) to support observations in the 40-50~GHz frequency range. To assess the suitability of the surface for this purpose, we measured the deviations of the primary surface from an ideal paraboloid using radio holography. We used the 11.6996 GHz beacon signal from the GSAT3 satellite, a 1.2~m reference antenna, commercial Ku-band Low Noise Block Convereters (LNBC) as the receiver front-ends and a Stanford Research Systems (SRS) lock-in amplifier as the backend. The LNBCs had independent free-running first local oscillators (LO). Yet, we recovered the correlation by using a radiatively injected common tone that served as the second local oscillator. With this setup, we mapped the surface deviations on a 64 × 64 grid and measured an rms surface deviation of ˜ 350~μm with a measurement accuracy of ˜ 50~μm.

  15. SCWRL and MolIDE: Computer programs for side-chain conformation prediction and homology modeling

    PubMed Central

    Wang, Qiang; Canutescu, Adrian A.; Dunbrack, Roland L.

    2009-01-01

    SCWRL and MolIDE are software applications for prediction of protein structures. SCWRL is designed specifically for the task of prediction of side-chain conformations given a fixed backbone usually obtained from an experimental structure determined by X-ray crystallography or NMR. SCWRL is a command-line program that typically runs in a few seconds. MolIDE provides a graphical interface for basic comparative (homology) modeling using SCWRL and other programs. MolIDE takes an input target sequence, and uses PSI-BLAST to identify and align templates for comparative modeling of the target. The sequence alignment to any template can be manually modified within a graphical window of the target-template alignment and visualization of the alignment on the template structure. MolIDE builds the model of the target structure based on the template backbone, predicted side-chain conformations with SCWRL, and a loop-modeling program for insertion-deletion regions with user-selected sequence segments. SCWRL and MolIDE can be obtained at http://dunbrack.fccc.edu/Software.php. PMID:18989261

  16. Real-Time PyMOL Visualization for Rosetta and PyRosetta

    PubMed Central

    Baugh, Evan H.; Lyskov, Sergey; Weitzner, Brian D.; Gray, Jeffrey J.

    2011-01-01

    Computational structure prediction and design of proteins and protein-protein complexes have long been inaccessible to those not directly involved in the field. A key missing component has been the ability to visualize the progress of calculations to better understand them. Rosetta is one simulation suite that would benefit from a robust real-time visualization solution. Several tools exist for the sole purpose of visualizing biomolecules; one of the most popular tools, PyMOL (Schrödinger), is a powerful, highly extensible, user friendly, and attractive package. Integrating Rosetta and PyMOL directly has many technical and logistical obstacles inhibiting usage. To circumvent these issues, we developed a novel solution based on transmitting biomolecular structure and energy information via UDP sockets. Rosetta and PyMOL run as separate processes, thereby avoiding many technical obstacles while visualizing information on-demand in real-time. When Rosetta detects changes in the structure of a protein, new coordinates are sent over a UDP network socket to a PyMOL instance running a UDP socket listener. PyMOL then interprets and displays the molecule. This implementation also allows remote execution of Rosetta. When combined with PyRosetta, this visualization solution provides an interactive environment for protein structure prediction and design. PMID:21857909

  17. Synthesis, Structure, and Characterization of Cu4S10(4-methylpyridine)4

    NASA Technical Reports Server (NTRS)

    Hepp, Aloysius F.; Richman, Robert M.; Duraj, Stan A.; Andras, Maria T.; Moore, Hall L.; Sabat, Michal; Eckles, William E.; Martuch, Robert A.

    1996-01-01

    The title compound, Cu4S10(4-methylpyridine)(sub 4) (dot) 4-methylpyridine was prepared by three different reactions: the oxidation of copper powder by sulfur and the reaction of copper (I) sulfide (or CuBr (dot) SMe2) with excess sulfur, both in the coordinating solvent, 4-methylpyridine. Red crystals of the compound obtained by layering with hexanes were subjected to single crystal X-ray diffraction. The structure was refined to R = 0.026 and R(sub w) = 0.036 in a space group P1bar (No. 2), with Z = 2, a = 13.983 (2) A, b = 15.384 (2) A, c = 9.660 (1) A, alpha = 93.87 (1)deg., beta = 93.38 (1)deg., gamma = 99.78 (1)deg., V = 2037.9 (9) A(exp 3). The compound has approximate S(sub 4) symmetry and consists of two pentasulfide chains linking four Cu(I) ions, each with a corrdinating 2-methylpyridine. The infrared spectrum was dominated by absorption due to coordinated 4-methylpyridine with several low-energy peaks attributable to S-S stretches, which were also observed by Raman spectroscopy. A featureless electronic absorption spectrum yielded a single peak in the near ultraviolet upon computer enhancement (lambda = 334 nm, epsilon = 10,000), most likely an intraligand transition. Cyclic voltammetry indicates that the polysulfide complex undergoes irrversible oxidation and reduction at +0.04 and -0.34 V vs. SCE, respectively, at 298 K in 4-methylpyridine when swept at 20 mV/sec. The electrochemical behavior was unvaried even at sweep rates as high as 100 V/sec.

  18. Microwave sintering of ZrO{sub 2}-12 mol% CeO{sub 2}

    SciTech Connect

    Janney, M.A.; Jackson, M.L.; Kimrey, H.D.

    1993-12-31

    Sintering of ZrO{sub 2}-12 mol% CeO{sub 2} was accelerated by microwave processing at 2.45 GHz as compared with conventional firing. However, the size of the ``microwave effect`` was significantly smaller than that which was previously observed for microwave sintering of ZrO{sub 2}-8 mol% Y{sub 2}O{sub 3}. The difference in the effect that the microwave field had on the two zirconia systems is interpreted in terms of their ionic conductivities.

  19. XmMol: an X11 and motif program for macromolecular visualization and modeling.

    PubMed

    Tufféry, P

    1995-02-01

    XmMol is a desktop tool designed to provide both interactive molecular graphics on X11 displays and easy interface with external applications. A kernel provides an interactive wire-frame display of macromolecules. It supports depth cueing, 3D clipping, and stereo. Various representations, coloring, and labeling modes are proposed. Docking and interactive backbone deformation tools are also supported. Communication protocols allow the user to develop new external features or to use XmMol as a visualization tool for external numerical programs. PMID:7794836

  20. COOMET.QM-K93 (COOMET 615/RU/13): key comparison in the field of measuring of the ethanol amount fraction in nitrogen (120 μmol/mol)

    NASA Astrophysics Data System (ADS)

    Konopelko, L. A.; Efremova, O. V.; Fatina, O. V.; Orshanskaia, A. A.; Rozhnov, M. S.; Melnyk, D. M.; Petryshyn, P. V.

    2016-01-01

    The relevance of the COOMET.QM-K93 comparison is founded on paying particular attention to reliability of measurements which are performed during the medical examination of drivers of vehicles in order to assess the degree of alcoholic intoxication. Standard gas mixtures of ethanol in nitrogen in cylinders under pressure play a key role in providing metrological assurance of breath-alcohol analyzers. Participating laboratories: VNIIM and Ukrmetrteststandart. This comparison was carried out in 2014-2015. This supplementary comparison supports CMC claims for: ethanol in the range 50-500 μmol/mol in a matrix of either nitrogen or synthetic air. Results: The results are consistent with the reference values. Main text To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

  1. CO/H2 Abundance Ratio ≈ 10-4 in a Protoplanetary Disk

    NASA Astrophysics Data System (ADS)

    France, Kevin; Herczeg, Gregory J.; McJunkin, Matthew; Penton, Steven V.

    2014-10-01

    The relative abundances of atomic and molecular species in planet-forming disks around young stars provide important constraints on photochemical disk models and provide a baseline for calculating disk masses from measurements of trace species. A knowledge of absolute abundances, those relative to molecular hydrogen (H2), are challenging because of the weak rovibrational transition ladder of H2 and the inability to spatially resolve different emission components within the circumstellar environment. To address both of these issues, we present new contemporaneous measurements of CO and H2 absorption through the "warm molecular layer" of the protoplanetary disk around the Classical T Tauri Star RW Aurigae A. We use a newly commissioned observing mode of the Hubble Space Telescope Cosmic Origins Spectrograph to detect warm H2 absorption in this region for the first time. An analysis of the emission and absorption spectrum of RW Aur shows components from the accretion region near the stellar photosphere, the molecular disk, and several outflow components. The warm H2 and CO absorption lines are consistent with a disk origin. We model the 1092-1117 Å spectrum of RW Aur to derive log10 N(H2) = 19.90+0.33-0.22 cm-2 at T rot(H2) = 440 ± 39 K. The CO A - X bands observed from 1410 to 1520 Å are best fit by log10 N(CO) = 16.1 +0.3-0.5 cm-2 at T rot(CO) = 200+650-125 K. Combining direct measurements of the H I, H2, and CO column densities, we find a molecular fraction in the warm disk surface of f H2 >= 0.47 and derive a molecular abundance ratio of CO/H2 = 1.6+4.7-1.3 × 10-4, both consistent with canonical interstellar dense cloud values. Based on observations made with the NASA/ESA Hubble Space Telescope, obtained from the data archive at the Space Telescope Science Institute. STScI is operated by the Association of Universities for Research in Astronomy, Inc. under NASA contract NAS 5-26555.

  2. Automated protein motif generation in the structure-based protein function prediction tool ProMOL.

    PubMed

    Osipovitch, Mikhail; Lambrecht, Mitchell; Baker, Cameron; Madha, Shariq; Mills, Jeffrey L; Craig, Paul A; Bernstein, Herbert J

    2015-12-01

    ProMOL, a plugin for the PyMOL molecular graphics system, is a structure-based protein function prediction tool. ProMOL includes a set of routines for building motif templates that are used for screening query structures for enzyme active sites. Previously, each motif template was generated manually and required supervision in the optimization of parameters for sensitivity and selectivity. We developed an algorithm and workflow for the automation of motif building and testing routines in ProMOL. The algorithm uses a set of empirically derived parameters for optimization and requires little user intervention. The automated motif generation algorithm was first tested in a performance comparison with a set of manually generated motifs based on identical active sites from the same 112 PDB entries. The two sets of motifs were equally effective in identifying alignments with homologs and in rejecting alignments with unrelated structures. A second set of 296 active site motifs were generated automatically, based on Catalytic Site Atlas entries with literature citations, as an expansion of the library of existing manually generated motif templates. The new motif templates exhibited comparable performance to the existing ones in terms of hit rates against native structures, homologs with the same EC and Pfam designations, and randomly selected unrelated structures with a different EC designation at the first EC digit, as well as in terms of RMSD values obtained from local structural alignments of motifs and query structures. This research is supported by NIH grant GM078077. PMID:26573864

  3. An extensively modified version of MolScript that includes greatly enhanced coloring capabilities.

    PubMed

    Esnouf, R M

    1997-04-01

    Owing to its flexibility, MolScript has become one of the most widely used programs for generating publication-quality molecular graphics. Integration with the Raster3D package, to allow the production of photorealistic rendered images, has increased its popularity still further. However, this intensive use has shown the need for enhancement of some areas of the program, especially for controlling the coloring of atoms, bonds, and molecules. This work describes a heavily modified version of MolScript that has added syntax for describing complicated coloring schemes and also has new graphics commands. Enhancements include drawing split-bond ball-and-stick models, smoothly varying the color of molecules (color ramping), abrupt color changes within secondary structural units, and the creation of dashed bonds. Making use of these added features is simple because all MolScript syntax is still supported and one typically needs only to add a few control commands. The final section of this article suggests some uses for this modified MolScript and provides illustrative examples. PMID:9385560

  4. A systematic framework for evaluating standard cell middle-of-line (MOL) robustness for multiple patterning

    NASA Astrophysics Data System (ADS)

    Xu, Xiaoqing; Cline, Brian; Yeric, Greg; Yu, Bei; Pan, David Z.

    2015-03-01

    Multiple patterning (triple and quadruple patterning) is being considered for use on the Middle-Of-Line (MOL) layers at the 10nm technology node and beyond.1 For robust standard cell design, designers need to improve the inter-cell compatibility for all combinations of cells and cell placements. Multiple patterning colorability checks break the locality of traditional rule checking and N-wise checks are strongly needed to verify the multiple patterning colorability for layout interaction across cell boundaries. In this work, a systematic framework is proposed to evaluate the library-level robustness over multiple patterning from two perpectives, including illegal cell combinations and full chip interactions. With efficient N-wise checks, the vertical and horizontal boundary checks are explored to predict illegal cell combinations. For full chip interactions, random benchmarks are generated by cell shifting and tested to evaluate the placement-level efforts needed to reduce the quadruple patterning to triple patterning for the MOL layer.

  5. Ligand-based virtual screening interface between PyMOL and LiSiCA.

    PubMed

    Dilip, Athira; Lešnik, Samo; Štular, Tanja; Janežič, Dušanka; Konc, Janez

    2016-01-01

    Ligand-based virtual screening of large small-molecule databases is an important step in the early stages of drug development. It is based on the similarity principle and is used to reduce the chemical space of large databases to a manageable size where chosen ligands can be experimentally tested. Ligand-based virtual screening can also be used to identify bioactive molecules with different basic scaffolds compared to already known bioactive molecules, thus having the potential to increase the structural variability of compounds. Here, we present an interface between the popular molecular graphics system PyMOL and the ligand-based virtual screening software LiSiCA available at http://insilab.org/lisica-plugin and demonstrate how this interface can be used in the early stages of drug discovery process.Graphical AbstractLigand-based virtual screening interface between PyMOL and LiSiCA. PMID:27606012

  6. SigMol: repertoire of quorum sensing signaling molecules in prokaryotes.

    PubMed

    Rajput, Akanksha; Kaur, Karambir; Kumar, Manoj

    2016-01-01

    Quorum sensing is a widespread phenomenon in prokaryotes that helps them to communicate among themselves and with eukaryotes. It is driven through quorum sensing signaling molecules (QSSMs) in a density dependent manner that assists in numerous biological functions like biofilm formation, virulence factors secretion, swarming motility, bioluminescence, etc. Despite immense implications, dedicated resources of QSSMs are lacking. Therefore, we have developed SigMol (http://bioinfo.imtech.res.in/manojk/sigmol), a specialized repository of these molecules in prokaryotes. SigMol harbors information on QSSMs pertaining to different quorum sensing signaling systems namely acylated homoserine lactones (AHLs), diketopiperazines (DKPs), 4-hydroxy-2-alkylquinolines (HAQs), diffusible signal factors (DSFs), autoinducer-2 (AI-2) and others. Database contains 1382: entries of 182: unique signaling molecules from 215: organisms. It encompasses biological as well as chemical aspects of signaling molecules. Biological information includes genes, preliminary bioassays, identification assays and applications, while chemical detail comprises of IUPAC name, SMILES and structure. We have provided user-friendly browsing and searching facilities for easy data retrieval and comparison. We have gleaned information of diverse QSSMs reported in literature at a single platform 'SigMol'. This comprehensive resource will assist the scientific community in understanding intraspecies, interspecies or interkingdom networking and further help to unfold different facets of quorum sensing and related therapeutics. PMID:26490957

  7. Production of high concentration of L-lactic acid from cellobiose by thermophilic Bacillus coagulans WCP10-4.

    PubMed

    Ong, Shufen Angeline; Ng, Zhi Jian; Wu, Jin Chuan

    2016-07-01

    Thermophilic Bacillus coagulans WCP10-4 is found to be able to convert cellobiose to optically pure L-lactic acid. Its β-glucosidase activity is detected in whole cells (7.3 U/g dry cells) but not in culture medium, indicating the intracellular location of the enzyme. Its β-glucosidase activity is observed only when cultured using cellobiose as the sole carbon source, indicating that the expression of this enzyme is tightly regulated in cells. The enzyme is most active at 50 °C and pH 7.0. The supplement of external β-glucosidase during fermentation of cellobiose (106 g/l) by B. coagulans WCP10-4 increased the fermentation time from 21 to 23 h and decreased the lactic acid yield from 96.1 to 92.9 % compared to the control without β-glucosidase supplementation. B. coagulans WCP10-4 converted 200 g/l of cellobiose to 196.3 g/l of L-lactic acid at a yield of 97.8 % and a productivity of 7.01 g/l/h. This result shows that B. coagulans WCP10-4 is a highly efficient strain for converting cellobiose to L-lactic acid without the need of supplementing external β-glucosidases. PMID:27183994

  8. Radiolysis of aqueous solutions of ammonium bicarbonate over a large dose range

    NASA Astrophysics Data System (ADS)

    Draganić, Z. D.; Negrón-Mendoza, A.; Sehested, K.; Vujošević, S. I.; Navarro-Gonzáles, R.; Albarrán-Sanchez, M. G.; Draganić, I. G.

    Oxygen-free aqueous solutions of 0.05 mol dm -3 ammonium and sodium bicarbonate were studied after receiving various doses of 60Co gammas (0.01-400 kGy) or 0.5-20 Gy pulses of 10 Mev electrons. Formate and oxalate were found to be the main radiolytic products, in addition to trace amounts of formaldehyde and an unidentified polymer. A large initial yield of formate in the γ-radiolysis, G( HCOO-)=2.2, is due to the reaction COO - + HCO -3⤦HCOO -+CO -3. The efficiency of organic synthesis within the large dose range studied is low and is explained by efficient pathways leading to the reformation of bicarbonate, where the reaction COO -+CO -3 is particularly significant. Computer fitting of the data obtained gives k(COO - + HCO -3)=(2±0.4) x 10 3 dm 3 mol -1 s -1, k(COO -+CO -3) = (5±1) x 10 7 dm 3 mol -1 s -1, k(NH 2+HCO -3)< 10 4 dm 3 mol -1 s -1, and k(NH 2+CO -3) = (1.5±0.5) x 10 9 dm 3 mol -1 s -1.

  9. VizieR Online Data Catalog: ExoMol line list for KCl (Barton+, 2014)

    NASA Astrophysics Data System (ADS)

    Barton, E. J.; Chui, C.; Golpayegani, S.; Yurchenko, S. N.; Tennyson, J.; Frohman, D. J.; Bernath, P. F.

    2014-03-01

    The files comprising this line list are in the standard ExoMol format, and are named sXXkYYcl.dat and tXXkYYcl.dat, where XX and YY are the mass numbers of the potassium and chlorine isotopes, respectively. The isotopologues covered are: (39K)(35Cl), (39K)(37Cl), (41K)(35Cl) and (41K)(37Cl). The partition functions from 1-3000K in 1K intervals for these isotopologues of KCl are also provided in files named pXXkYYcl.dat and consist of two columns (T/K followed by Q). (12 data files).

  10. Moléculas orgánicas obtenidas en simulaciones experimentales del medio interestelar.

    NASA Astrophysics Data System (ADS)

    Muñoz-Caro, Guillermo Manuel

    Las nubes moleculares son regiones de formación de estrellas, con temperaturas cinéticas entre 10-50 K y densidades de 103-106 átomos cm-3. Su materia está formada por gas y polvo interestelar. Estas partículas de polvo están cubiertas por una fina capa de hielo, de unos 0.01 μm, que contiene H2O y a menudo CO, CO2, CH3OH y NH3. El hielo es presumiblemente irradiado por fotones ultravioleta y rayos cósmicos en las zonas poco profundas de las nubes moleculares y las regiones circunestelares. En un sistema de vacío, P ˜ 10-7 mbar, simulamos la deposición de hielo a partir de 10 K y la irradiación ultravioleta por medio de una lámpara de descarga de hidrógeno activada con microondas. La evolución del hielo se observa por medio de un espectrómetro infrarrojo. De este modo es posible determinar la composición del hielo observado en el medio interestelar y predecir la presencia de moléculas aún no detectadas en el espacio, que han sido producto del procesamiento del hielo en nuestros experimentos. También es posible calentar el sistema hasta temperatura ambiente para sublimar el hielo depositado. Cuando el hielo ha sido previamente irradiado, se observa un residuo compuesto por moléculas orgánicas complejas, algunas prebióticas, como varios ácidos carboxílicos, aminas, amidas, ésteres y en menor proporción moléculas heterocíclicas y aminoácidos. Algunas de estas moléculas podrían detectarse en estado gaseoso por medio de observaciones milimétricas y de radio. También podrían estar presentes en el polvo cometario, cuyo análisis químico está planeado por las misiones Stardust y Rosetta. Mientras tanto, nuestro grupo está llevando a cabo el análisis de partículas de polvo interplanetario (IDPs), algunas de las cuales pueden ser de origen cometario. Al igual que ocurre con los productos obtenidos por irradiación del hielo en nuestros experimentos, algunas IDPs son ricas en material orgánico que contiene oxígeno.

  11. Classification moléculaire du cancer du sein au Maroc

    PubMed Central

    Fouad, Abbass; Yousra, Akasbi; Kaoutar, Znati; Omar, El Mesbahi; Afaf, Amarti; Sanae, Bennis

    2012-01-01

    Introduction La classification moléculaire des cancers du sein basée sur l'expression génique puis sur le profil protéique a permis de distinguer cinq groupes moléculaires: luminal A, luminal B, Her2/neu, basal-like et non-classées. L'objectif de cette étude réalisée au CHU Hassan II de Fès est de classer 335 cancers du sein infiltrant en groupes moléculaires, puis de les corréler avec les caractéristiques clinicopathologiques. Méthodes Etude rétrospective étalée sur 45 mois, comportant 335 patientes colligées au CHU pour le diagnostic et le suivi. Les tumeurs sont analysées histologiquement et classées après une étude immunohistochimique en groupes: luminal A, luminal B, Her2+, basal-like et non-classées. Résultats 54.3% des tumeurs sont du groupe luminal A, 16% luminal B, 11.3% Her2+, 11.3% basal-like et 7% non-classées. Le groupe luminal A renferme le plus faible taux de grade III, d'emboles vasculaires ainsi que de métastases; alors que le groupe des non-classées et basal-like représentent un taux élevé de grade III, une faible proportion d'emboles vasculaires et d'envahissement ganglionnaire. Ces facteurs sont significativement élevés dans les groupes luminal B et Her2+ avec un taux de survie globale de 78% et 76% respectivement. Dans le groupe luminal A, la survie globale des patientes est élevée (87%) alors qu'elle n'est que de 49% dans le groupe des triples négatifs (basal-like et non-classés). Conclusion Le groupe luminal B est différent du luminal A et il est de pronostic péjoratif vis à vis du groupe Her2+. Les caractéristiques clinicopathologiques concordent avec le profil moléculaire donc devraient être pris en considération comme facteurs pronostiques. PMID:23396646

  12. Microbes at their best: first Mol Micro Meeting Würzburg.

    PubMed

    Böhm, Alex; Papenfort, Kai; Lopez, Daniel; Vogel, Jörg

    2011-11-01

    Founded on ground-breaking discoveries such as the operon model by Jacob and Monod more than 50 years ago, molecular microbiology is now one of the most vibrant disciplines of the life sciences. The first Mol Micro Meeting Würzburg ('M3W') hosted more than 160 scientists from 14 countries to exchange their latest ideas in this field of research. Divided into the four main sessions Gene Regulation, Pathogenesis, Microbial Cell Biology and Signalling, the conference provided insight into current advances and future goals and challenges. PMID:21999404

  13. A new value for mol percent guanine + cytosine of DNA for the salmonid fish pathogen Renibacterium salmoninarum.

    PubMed

    Banner, C R; Rohovec, J S; Fryer, J L

    1991-03-15

    The mol% G + C of DNA extracted from seven different isolates of Renibacterium salmoninarum was determined. Organisms studied were from selected geographical areas (U.S.A., Canada, England and France) and were isolated from five different species of salmonid fish. The mol% G + C was determined to be 55.5, higher than the currently reported value of 53. PMID:2044940

  14. Data structures for ExoMol: Molecular line lists for exoplanet and other atmospheres

    NASA Astrophysics Data System (ADS)

    Tennyson, Jonathan; Hill, Christian; Yurchenko, Sergei N.

    2013-07-01

    At elevated temperatures the spectra of polyatomic molecules become extremely complicated with millions, or even billions, of transitions potentially playing an important role. The atmospheres of cool stars and "hot Jupiter" extrasolar planets are rich with molecules in the temperature range 1000 to 3000 K and their properties are strongly influenced by the infrared and visible spectra of these molecules. Access to extensive lists of transitions is essential for interpreting even the rather simple spectra that can be obtained from exoplanets. So far there are extensive, reliable lists of spectral lines for a number species including some stable diatomics, water and ammonia. Data are almost completely lacking for many key species such as methane. The ExoMol project aims to construct line lists of molecular transitions suitable for spectroscopic and atmospheric modelling of cool stars and exoplanets. At high temperatures it is necessary to consider huge numbers of lines even for a single species. Examples of line lists are given; data protocols defined and data handling issues which arise from trying to distribute these huge datasets discussed. In particular, a uniform but flexible format is given for the representation of line lists and cross sections resulting from the ExoMol project.

  15. SigMol: repertoire of quorum sensing signaling molecules in prokaryotes

    PubMed Central

    Rajput, Akanksha; Kaur, Karambir; Kumar, Manoj

    2016-01-01

    Quorum sensing is a widespread phenomenon in prokaryotes that helps them to communicate among themselves and with eukaryotes. It is driven through quorum sensing signaling molecules (QSSMs) in a density dependent manner that assists in numerous biological functions like biofilm formation, virulence factors secretion, swarming motility, bioluminescence, etc. Despite immense implications, dedicated resources of QSSMs are lacking. Therefore, we have developed SigMol (http://bioinfo.imtech.res.in/manojk/sigmol), a specialized repository of these molecules in prokaryotes. SigMol harbors information on QSSMs pertaining to different quorum sensing signaling systems namely acylated homoserine lactones (AHLs), diketopiperazines (DKPs), 4-hydroxy-2-alkylquinolines (HAQs), diffusible signal factors (DSFs), autoinducer-2 (AI-2) and others. Database contains 1382 entries of 182 unique signaling molecules from 215 organisms. It encompasses biological as well as chemical aspects of signaling molecules. Biological information includes genes, preliminary bioassays, identification assays and applications, while chemical detail comprises of IUPAC name, SMILES and structure. We have provided user-friendly browsing and searching facilities for easy data retrieval and comparison. We have gleaned information of diverse QSSMs reported in literature at a single platform ‘SigMol’. This comprehensive resource will assist the scientific community in understanding intraspecies, interspecies or interkingdom networking and further help to unfold different facets of quorum sensing and related therapeutics. PMID:26490957

  16. MegaMol--A Prototyping Framework for Particle-Based Visualization.

    PubMed

    Grottel, Sebastian; Krone, Michael; Muller, Christoph; Reina, Guido; Ertl, Thomas

    2015-02-01

    Visualization applications nowadays not only face increasingly larger datasets, but have to solve increasingly complex research questions. They often require more than a single algorithm and consequently a software solution will exceed the possibilities of simple research prototypes. Well-established systems intended for such complex visual analysis purposes have usually been designed for classical, mesh-based graphics approaches. For particle-based data, however, existing visualization frameworks are too generic - e.g. lacking possibilities for consistent low-level GPU optimization for high-performance graphics - and at the same time are too limited - e.g. by enforcing the use of structures suboptimal for some computations. Thus, we developed the system softwareMegaMol for visualization research on particle-based data. On the one hand, flexible data structures and functional module design allow for easy adaption to changing research questions, e.g. studying vapors in thermodynamics, solid material in physics, or complex functional macromolecules like proteins in biochemistry. Therefore, MegaMol is designed as a development framework. On the other hand, common functionality for data handling and advanced rendering implementations are available and beneficial for all applications. We present several case studies of work implemented using our system as well as a comparison to other freely available or open source systems. PMID:26357030

  17. MolProbity’s Ultimate Rotamer-Library Distributions for Model Validation

    PubMed Central

    Hintze, Bradley J.; Lewis, Steven M.; Richardson, Jane S.; Richardson, David C.

    2016-01-01

    Here we describe the updated MolProbity rotamer-library distributions derived from an order-of-magnitude larger and more stringently quality-filtered dataset of about 8000 (vs. 500) protein chains, and we explain the resulting changes and improvements to model validation as seen by users. To include only sidechains with satisfactory justification for their given conformation, we added residue-specific filters for electron-density value and model-to-density fit. The combined new protocol retains a million residues of data, while cleaning up false-positive noise in the multi-χ datapoint distributions. It enables unambiguous characterization of conformational clusters nearly 1000-fold less frequent than the most common ones. We describe examples of local interactions that favor these rare conformations, including the role of authentic covalent bond-angle deviations in enabling presumably strained sidechain conformations. Further, along with favored and outlier, an allowed category (0.3% to 2.0% occurrence in reference data) has been added, analogous to Ramachandran validation categories. The new rotamer distributions are used for current rotamer validation in Mol-Probity and PHENIX, and for rotamer choice in PHENIX model-building and refinement. The multi-dimensional χ distributions and Top8000 reference dataset are freely available on GitHub. These rotamers are termed “ultimate” because data sampling and quality are now fully adequate for this task, and also because we believe the future of conformational validation should integrate sidechain with backbone criteria. PMID:27018641

  18. A novel protoapigenone analog RY10-4 induces breast cancer MCF-7 cell death through autophagy via the Akt/mTOR pathway

    SciTech Connect

    Zhang, Xuenong; Wei, Han; Liu, Ziwei; Yuan, Qianying; Wei, Anhua; Shi, Du; Yang, Xian; Ruan, Jinlan

    2013-07-15

    Protoapigenone is a unique flavonoid and enriched in many ferns, showing potent antitumor activity against a broad spectrum of human cancer cell lines. RY10-4, a modified version of protoapigenone, manifested better anti-proliferation activity in human breast cancer cell line MCF-7. The cytotoxicity of RY10-4 against MCF-7 cells is exhibited in both time- and concentration-dependent manners. Here we investigated a novel effect of RY10-4 mediated autophagy in autophagy defect MCF-7 cells. Employing immunofluorescence assay for microtubule-associated protein light-chain 3 (LC3), monodansylcadaverine staining, Western blotting analyses for LC3 and p62 as well as ultrastructural analysis by transmission electron microscopy, we showed that RY10-4 induced autophagy in MCF-7 cells but protoapigenone did not. Meanwhile, inhibition of autophagy by pharmacological and genetic approaches significantly increased the viability of RY10-4 treated cells, suggesting that the autophagy induced by RY10-4 played as a promotion mechanism for cell death. Further studies revealed that RY10-4 suppressed the activation of mTOR and p70S6K via the Akt/mTOR pathway. Our results provided new insights for the mechanism of RY10-4 induced cell death and the cause of RY10-4 showing better antitumor activity than protoapigenone, and supported further evidences for RY10-4 as a lead to design a promising antitumor agent. - Highlights: • We showed that RY10-4 induced autophagy in MCF-7 cells but protoapigenone did not. • Autophagy induced by RY10-4 played as a promotion mechanism for cell death. • RY10-4 induced autophagy in MCF-7 cell through the Akt/mTOR pathway. • We provided new insights for the mechanism of RY10-4 induced cell death.

  19. GTKDynamo: a PyMOL plug-in for QC/MM hybrid potential simulations.

    PubMed

    Bachega, José Fernando R; Timmers, Luís Fernando S M; Assirati, Lucas; Bachega, Leonardo R; Field, Martin J; Wymore, Troy

    2013-09-30

    Hybrid quantum chemical/molecular mechanical (QCMM) potentials are very powerful tools for molecular simulation. They are especially useful for studying processes in condensed phase systems, such as chemical reactions that involve a relatively localized change in electronic structure and where the surrounding environment contributes to these changes but can be represented with more computationally efficient functional forms. Despite their utility, however, these potentials are not always straightforward to apply since the extent of significant electronic structure changes occurring in the condensed phase process may not be intuitively obvious. To facilitate their use, we have developed an open-source graphical plug-in, GTKDynamo that links the PyMOL visualization program and the pDynamo QC/MM simulation library. This article describes the implementation of GTKDynamo and its capabilities and illustrates its application to QC/MM simulations. PMID:24137667

  20. VizieR Online Data Catalog: ExoMol line lists for CS isotopologues (Paulose+, 2015)

    NASA Astrophysics Data System (ADS)

    Paulose, G.; Barton, E. J.; Yurchenko, S. N.; Tennyson, J.

    2015-07-01

    The files comprising this line list are in the standard ExoMol format, and are named XXcYYsst.dat, XXcYYstr.dat, where XX and YY are the mass numbers of the Carbon and Sulphur isotopes, respectively. The isotopologues covered including their nuclear spin degeneracy factors g_ns are: (12C)(32S) g_ns = 1 (12C)(33S) g_ns = 4 (12C)(34S) g_ns = 1 (12C)(36S) g_ns = 1 (13C)(32S) g_ns = 2 (13C)(33S) g_ns = 8 (13C)(34S) g_ns = 2 (13C)(36S) g_ns = 2 The partition functions from 1-3000K in 1K intervals for these isotopologues of CS are also provided in files named XXcYYspf.dat. (24 data files).

  1. Kilogramm und Mol: SI-Basiseinheiten für Masse und Stoffmenge

    NASA Astrophysics Data System (ADS)

    Becker, Peter; Gläser, Michael

    2001-11-01

    Das Kilogramm ist eine SI-Basiseinheit, die bislang nicht hinreichend genau auf Naturkonstanten zurückgeführt werden kann. Gegenwärtig gibt es verschiedene Vorschläge, dieses Problem zu lösen. Ein Vorschlag ist die Neudefinition des Kilogramm auf Basis atomarer Massen. An der Physikalisch-Technischen Bundesanstalt (PTB) wird dazu an zwei verschiedenen Verfahren geforscht. Beim ersten Verfahren werden Goldionen zu einer Referenzmasse akkumuliert, beim zweiten die Avogadro-Konstante an einem Silizium-Einkristall bestimmt. Beide Verfahren könnten eine genau bestimmbare Zahl von Atomen liefern, mit der das Kilogramm neu definiert werden könnte. Dies könnte eine Zahl von 197 Au, von 28 Si oder auch von 12 C-Atomen sein, auf der bereits die SI-Einheit der Stoffmenge des Mol basiert.

  2. Moléculas orgánicas no-rígidas

    NASA Astrophysics Data System (ADS)

    Senent Díez, M. L.

    Se destaca la importancia del estudio espectroscópico ab initio de una serie de moléculas no-rígidas detectadas en el medio interestelar (acetona, dimetil-eter, etanol, metanol, metilamina, ldots), así como los últimos avances del desarrollo de la metodología para el tratamiento teórico de estas especies. Se describe, a modo de ejemplo, el análisis del espectro roto-torsional de la molécula de glicoaldehido que ha sido recientemente detectada en el centro Galáctico Sagitario B2 (N) [1]. Esta especie presenta dos movimientos de gran amplitud que interaccionan, descansan en el Infrarrojo Lejano y le confiere propiedades no-rígidas. La molécula puede existir en posiciones cis y trans y presenta cinco confórmeros estables, tres de simetría Cs (I, II y IV) y un doble mínimo trans de simetría C1 (III) . La conformación favorita, I, presenta simetría Cs y se estabiliza por la formación de un puente de hidrógeno entre los grupos OH y C=O. Los mínimos secundarios II, III, y IV se han determinado a 1278.2 cm-1 (trans, Cs), 1298.8 cm-1 (trans, C1) y 1865.2 cm-1 (cis, Cs) con cálculos MP4/cc-pVQZ que incluyen sustituciones triples. Para determinar que vibraciones interaccionan con las torsiones, se ha realizado un análisis armónico en los mínimos. Las frecuencias fundamentales armónicas correspondientes al mínimo I se han calculado en 213.4 cm-1 (torsión C-C) y 425.7 cm-1 (torsión OH). Es de esperar que tan sólo dos vibraciones, la flexión del grupo C-C-O y el aleteo del hidrógeno del grupo aldehídico puedan desplazar el espectro torsional de la molécula aislada. Para determinar el espectro torsional, se ha determinado la superficie de potencial en dos dimensiones mediante el cálculo ab initio de las geometrías y energías de 74 conformaciones seleccionadas. Estas últimas se han ajustado a un doble serie de Fourier. A partir de la PES y de los parámetros cinéticos del Hamiltoniano vibracional se han obtenido frecuencias e intensidades

  3. W4 theory for computational thermochemistry : in pursuit of confident sub-kJ/mol predictions.

    SciTech Connect

    Karton, A.; Rabinovich, E.; Martin, J. M. L.; Ruscic, B.; Chemistry; Weizmann Institute of Science

    2006-01-01

    In an attempt to improve on our earlier W3 theory [A. D. Boese et al., J. Chem. Phys. 120, 4129 (2004)] we consider such refinements as more accurate estimates for the contribution of connected quadruple excitations ({cflx T}{sub 4}), inclusion of connected quintuple excitations ({cflx T}{sub 5}), diagonal Born-Oppenheimer corrections (DBOC), and improved basis set extrapolation procedures. Revised experimental data for validation purposes were obtained from the latest version of the Active Thermochemical Tables thermochemical network. The recent CCSDT(Q) method offers a cost-effective way of estimating {cflx T}{sub 4} but is insufficient by itself if the molecule exhibits some nondynamical correlation. The latter considerably slows down basis set convergence for {cflx T}{sub 4}, and anomalous basis set convergence in highly polar systems makes two-point extrapolation procedures unusable. However, we found that the CCSDTQ-CCSDT(Q) difference converges quite rapidly with the basis set, and that the formula 1.10[CCSDT(Q)/cc-pVTZ+CCSDTQ/cc-pVDZ-CCSDT(Q)/cc-pVDZ] offers a very reliable as well as fairly cost-effective estimate of the basis set limit {cflx T}{sub 4} contribution. The {cflx T}{sub 5} contribution converges very rapidly with the basis set, and even a simple double-zeta basis set appears to be adequate. The largest {cflx T}{sub 5} contribution found in the present work is on the order of 0.5 kcal/mol (for ozone). DBOCs are significant at the 0.1 kcal/mol level in hydride systems. Post-CCSD(T) contributions to the core-valence correlation energy are only significant at that level in systems with severe nondynamical correlation effects. Based on the accumulated experience, a new computational thermochemistry protocol for first- and second-row main-group systems, to be known as W4 theory, is proposed. Its computational cost is not insurmountably higher than that of the earlier W3 theory, while performance is markedly superior. Our W4 atomization energies for

  4. Stratospheric temperature profile from balloon-borne measurements of the 10.4-micron band of CO2

    NASA Technical Reports Server (NTRS)

    Rinsland, C. P.; Goldman, A.; Murcray, F.J.; Murcray, D. G.; Smith, M. A. H.; Seals, R. K., Jr.; Larsen, J. C.; Rinsland, P. L.

    1983-01-01

    The technique of nonlinear least squares spectral curve fitting has been used to derive the stratospheric vertical temperature profile from balloon-borne measurements of the 10.4 micron band of CO2. The spectral data were obtained at sunset with the approximately 0.02 per cm resolution University of Denver interferometer system from a float altitude of 33.5 km near Alamogordo, New Mexico, on 23 March 1981. The r.m.s. deviation between the retrieved temperature profile and correlative radiosonde measurements is 2.2 K.

  5. Improvements in GROMACS plugin for PyMOL including implicit solvent simulations and displaying results of PCA analysis.

    PubMed

    Makarewicz, Tomasz; Kaźmierkiewicz, Rajmund

    2016-05-01

    In order to get the dynamic molecule model from the static one, the molecular dynamics (MD) simulation needs to be performed. Some software sets such as GROMACS are used for that purpose. Unfortunately they lack GUI. The Dynamics PyMOL plugin allows researcher to perform MD simulations directly from the PyMOL software by GUI-based interface of GROMACS tools. This paper describes many improvements introduced into the Dynamics PyMOL plugin 2.0 including: an integration with ProDy library, possibility to use the implicit solvents, an ability to interpret the MD simulations, and implementation of some more GROMACS functionality. PMID:27107576

  6. Three-dimensional hydration layer mapping on the (10.4) surface of calcite using amplitude modulation atomic force microscopy

    NASA Astrophysics Data System (ADS)

    Marutschke, Christoph; Walters, Deron; Cleveland, Jason; Hermes, Ilka; Bechstein, Ralf; Kühnle, Angelika

    2014-08-01

    Calcite, the most stable modification of calcium carbonate, is a major mineral in nature. It is, therefore, highly relevant in a broad range of fields such as biomineralization, sea water desalination and oil production. Knowledge of the surface structure and reactivity of the most stable cleavage plane, calcite (10.4), is pivotal for understanding the role of calcite in these diverse areas. Given the fact that most biological processes and technical applications take place in an aqueous environment, perhaps the most basic—yet decisive—question addresses the interaction of water molecules with the calcite (10.4) surface. In this work, amplitude modulation atomic force microscopy is used for three-dimensional (3D) mapping of the surface structure and the hydration layers above the surface. An easy-to-use scanning protocol is implemented for collecting reliable 3D data. We carefully discuss a comprehensible criterion for identifying the solid-liquid interface within our data. In our data three hydration layers form a characteristic pattern that is commensurate with the underlying calcite surface.

  7. Three-dimensional hydration layer mapping on the (10.4) surface of calcite using amplitude modulation atomic force microscopy.

    PubMed

    Marutschke, Christoph; Walters, Deron; Walters, Deron; Hermes, Ilka; Bechstein, Ralf; Kühnle, Angelika

    2014-08-22

    Calcite, the most stable modification of calcium carbonate, is a major mineral in nature. It is, therefore, highly relevant in a broad range of fields such as biomineralization, sea water desalination and oil production. Knowledge of the surface structure and reactivity of the most stable cleavage plane, calcite (10.4), is pivotal for understanding the role of calcite in these diverse areas. Given the fact that most biological processes and technical applications take place in an aqueous environment, perhaps the most basic - yet decisive - question addresses the interaction of water molecules with the calcite (10.4) surface. In this work, amplitude modulation atomic force microscopy is used for three-dimensional (3D) mapping of the surface structure and the hydration layers above the surface. An easy-to-use scanning protocol is implemented for collecting reliable 3D data. We carefully discuss a comprehensible criterion for identifying the solid-liquid interface within our data. In our data three hydration layers form a characteristic pattern that is commensurate with the underlying calcite surface. PMID:25074402

  8. Geophysical data from boreholes DM1, DM2, DM3, and DM3a, New Hydraulic Fracturing Facility, Oak Ridge National Laboratory, Oak Ridge, Tennessee

    SciTech Connect

    Haase, C S

    1987-03-01

    A comprehensive suite of geophysical logs was obtained from four deep monitoring boreholes at the New Hydrofracture Facility. The logging was an attempt to obtain stratigraphic, structural, and hydrologic information on the subsurface environment surrounding the hydrofracture facility. Logs obtained include caliper, gamma, neutron, density, single-point resistance, long- and short-normal resistivity, spontaneous potential, temperature, acoustic velocity, variable density, and borehole televiewer. Analysis and interpretation of the geophysical logs allowed the stratigraphic section at the facility to be determined and, by comparison with calibrated geophysical logs from borehole ORNL-Joy No. 2, allowed detailed inferences to be drawn about rock types and properties at the hydrofracture facility. Porosity values measured from the logs for Conasauga Group strata, as well as permeability values inferred from the logs, are low. Several intervals of apparently greater permeability, associated primarily with limestone-rich portions of the Maryville Limestone and sandstone-rich portions of the Rome Formation, were noted. Numerous fractures were identified by using several logs in combination. No one geophysical log was reliable for fracture identification although the acoustic-televiewer log appeared to have the greatest success. In addition to their characterization of subsurface conditions in the vicinity of the hydrofracture facility, the geophysical logs provided data on the extent of hydraulic fractures. Anomalies on single-point resistance logs that corresponded to prominent fractures identified on televiewer logs indicate intervals affected by hydraulic fractures associated with waste injection at the New Hydrofracture Facility. 14 refs.

  9. Antifungal and antibacterial activities of Araucaria araucana (Mol.) K. Koch heartwood lignans.

    PubMed

    Céspedes, Carlos L; Avila, J Guillermo; García, Ana M; Becerra, José; Flores, Cristian; Aqueveque, Pedro; Bittner, Magalis; Hoeneisen, Maritza; Martinez, Miguel; Silva, Mario

    2006-01-01

    Five lignans (secoisolariciresinol, pinoresinol, eudesmin, lariciresinol, and lariciresinol-4-methyl ether) were isolated from an MeOH extract from Araucaria araucana (Mol.) K. Koch wood for the first time in this species and their structures determined with spectroscopic methods. The antimicrobial activities of these compounds were determined for the bacteria Citrobacter sp., Bacillus subtilis, Escherichia coli, Micrococcus luteus, Staphylococcus aureus, and Pseudomonas aeruginosa, and for the white rooting and staining fungi Mucor miehei, Paecilomyces variotii, Ceratocystis pilifera, Trametes versicolor, and Penicillium notatum, and in addition, the MeOH extract was evaluated against Aspergillus niger, Candida albicans, Fusarium moniliforme, F. sporotrichum and Trichophyton mentagrophytes. The most sensitive bacteria against pinoresinol were the Gram-positive. However, secoisolariciresinol exhibited a significant antifungal activity on fungi of white rooting and wood staining and this compound completely inhibited the mycelial growth of T. versicolor and C. pilifera at 300 and 400 microg per disc, respectively, whereas pinoresinol showed a moderate inhibitory activity. On the other hand, the MeOH extract had the highest activity against rooting and staining and pathogenic fungi as well as T. versicolor, Fusarium spp. and Trichophyton mentagrophytes, inhibiting completely the growth at 400 microg per disc. PMID:16610214

  10. Synthesis and Properties of La2O3-Doped 8 mol% Yttria-Stabilized Cubic Zirconia

    NASA Astrophysics Data System (ADS)

    Aktas, Bulent; Tekeli, Suleyman; Salman, Serdar

    2014-01-01

    In this study, 8 mol% yttria-stabilized cubic zirconia (8YSZ) powder as a matrix material and 0-15 wt.% La2O3 powder as an additive were used to determine the effect of La2O3 addition and its amount on the phase stability, microstructure, sintering, and mechanical properties of 8YSZ. Colloidal processing was used to mix the powders uniformly and to obtain a homogenous microstructure. XRD results showed the existence of only a cubic crystal structure for 1 and 5 wt.% La2O3 addition amounts. However, La2Zr2O7 with a hexagonal and cubic crystal structure was observed in 8YSZ specimens doped with 10 and 15 wt.% La2O3. Further, up to 5 wt.% La2O3 was completely dissolved in the crystal structure of the specimens; however, above 5 wt.%, La2O3 reacted with 8YSZ at high temperatures and formed pyrochloric La2Zr2O7. Grain size measurements revealed that the grain size of 8YSZ increased up to 1 wt.% La2O3 addition, and then decreased beyond this amount. The hardness and fracture toughness of 8YSZ decreased and increased, respectively, with the increasing La2O3 amount.

  11. Detailed analyses of fresh and dried maqui (Aristotelia chilensis (Mol.) Stuntz) berries and juice.

    PubMed

    Brauch, J E; Buchweitz, M; Schweiggert, R M; Carle, R

    2016-01-01

    In this study, a detailed chemical characterization of nutritionally-relevant, quality-determining constituents in dried and fresh fruits as well as juices of maqui (Aristotelia chilensis (Mol.) Stuntz) is provided. A total of 8 glycosylated anthocyanins was characterized in maqui fruits, being composed of differently substituted cyanidin and delphinidin derivatives. During processing into juice, a substantial loss in total anthocyanin contents (TAC) was observed. TAC values were also reduced after drying of maqui berries. Likewise, the browning index (BI) of fresh fruits increased during processing. Being composed of flavonol glycosides and ellagic acids, 17 non-anthocyanin phenolics were characterized in all maqui samples. Besides characterizing phenolic compounds, antioxidant activities, total phenolics, major sugars, non-volatile organic acids, minerals and trace elements were quantitated. Moreover, total lipid contents and the fruits' mainly unsaturated fatty acid profiles are reported. The presented results indicate the high potential of maqui as so far under-utilized but extremely pigment-rich "superfruit". PMID:26212975

  12. molSimplify: A toolkit for automating discovery in inorganic chemistry.

    PubMed

    Ioannidis, Efthymios I; Gani, Terry Z H; Kulik, Heather J

    2016-08-15

    We present an automated, open source toolkit for the first-principles screening and discovery of new inorganic molecules and intermolecular complexes. Challenges remain in the automatic generation of candidate inorganic molecule structures due to the high variability in coordination and bonding, which we overcome through a divide-and-conquer tactic that flexibly combines force-field preoptimization of organic fragments with alignment to first-principles-trained metal-ligand distances. Exploration of chemical space is enabled through random generation of ligands and intermolecular complexes from large chemical databases. We validate the generated structures with the root mean squared (RMS) gradients evaluated from density functional theory (DFT), which are around 0.02 Ha/au across a large 150 molecule test set. Comparison of molSimplify results to full optimization with the universal force field reveals that RMS DFT gradients are improved by 40%. Seamless generation of input files, preparation and execution of electronic structure calculations, and post-processing for each generated structure aids interpretation of underlying chemical and energetic trends. © 2016 Wiley Periodicals, Inc. PMID:27364957

  13. Micropropagation of Prosopis chilensis (Mol.) Stuntz from young and mature plants.

    PubMed

    Caro, L A; Polci, P A; Lindström, L I; Echenique, C V; Hernández, L F

    2002-04-01

    Prosopis chilensis (Mol.) Stuntz (Algarrobo de Chile) is an important native tree species that can be grown in arid and semiarid regions for wood and forage production and environmental protection. Developing a simple and reliable in vitro protocol for cloning it would enable to improve it genetically. Explants of P. chilensis were taken from 4 months-old plants grown in the greenhouse or from adult trees grown in a natural environment. Nodal segments 1-2 cm long containing an axillary bud were selected from elongating shoots. These cuttings were aseptically cultured on two agar-solid basal media, MS or BTMm, and treated with 0.05 mg L-1 BA and 3 mg L-1 of either IAA, IBA or NAA. Sucrose (3% w/v) was used as carbon source. The percentage of sprouted cuttings and whole plant regeneration as well as its shoot and root length were recorded. Number, length and dry weight of shoots and roots were also measured. Rooting was successful with cuttings taken from young or adult plants, but explants from young plants showed a better response. Culturing in BTMm resulted in significantly greater shoot and root biomass than culturing in MS. Moreover, this response was higher in young explants when IBA was used as growth regulator. This paper reports a simple and effective method to micropropagate P. chilensis from young and adult plants. PMID:12058379

  14. Combination therapy of RY10-4 with the γ-secretase inhibitor DAPT shows promise in treating HER2-amplified breast cancer.

    PubMed

    Su, Feng; Zhu, Shilin; Ruan, Jinlan; Muftuoglu, Yagmur; Zhang, Longbo; Yuan, Qianying

    2016-01-26

    RY10-4, a novel protoapigenone analog, shows potent cytotoxicity against human breast cancer cells. However, breast cancer cell lines overexpressing human epidermal growth factor receptor 2 (HER2), SKBR3 and BT474, showed less sensitivity to RY10-4 when compared to breast cancer cells lines expressing lower levels of HER2, such as MDA-MB-231 and MCF-7 cells. This was associated with aberrant hyperactivity in Notch signaling in cells treated with RY10-4, since treatment with RY10-4 causes an increase in Notch activity by 2-to3.5-fold in SKBR3 and BT474 cell lines. The increase in activity was abrogated with a γ-secretase inhibitor, DAPT, or with Notch1 small-interfering RNA (si-Notch1). Cell proliferation was inhibited more effectively by RY10-4 plus DAPT or si-Notch1 than either agent alone. RY10-4 plus DAPT increases apoptosis in both HER2-overexpressing cell lines by two-fold compared to RY10-4 alone, while DAPT alone has no significant effects on apoptosis. In addition, we previously found RY10-4 could inhibit tumor growth through the PI3K/AKT pathway. Here we report that the combination of RY10-4 and DAPT exhibit additive suppression on AKT phosphorylation, contributing to the anti-cancer effects. In an animal model, this combination therapy inhibits the growth of SKBR3 tumor xenografts in nude mice to a greater extent than treatment with either reagent alone. These results indicate that the aberrant activation of Notch signaling impedes the inhibitory effect of RY10-4 on HER2-amplified cell proliferation. Furthermore, these adverse effects can be prevented by treatment combining RY10-4 with a Notch pathway inhibitor. PMID:26716652

  15. Combination therapy of RY10-4 with the γ-secretase inhibitor DAPT shows promise in treating HER2-amplified breast cancer

    PubMed Central

    Su, Feng; Zhu, Shilin; Ruan, Jinlan; Muftuoglu, Yagmur; Zhang, Longbo; Yuan, Qianying

    2016-01-01

    RY10-4, a novel protoapigenone analog, shows potent cytotoxicity against human breast cancer cells. However, breast cancer cell lines overexpressing human epidermal growth factor receptor 2 (HER2), SKBR3 and BT474, showed less sensitivity to RY10-4 when compared to breast cancer cells lines expressing lower levels of HER2, such as MDA-MB-231 and MCF-7 cells. This was associated with aberrant hyperactivity in Notch signaling in cells treated with RY10-4, since treatment with RY10-4 causes an increase in Notch activity by 2-to3.5-fold in SKBR3 and BT474 cell lines. The increase in activity was abrogated with a γ-secretase inhibitor, DAPT, or with Notch1 small-interfering RNA (si-Notch1). Cell proliferation was inhibited more effectively by RY10-4 plus DAPT or si-Notch1 than either agent alone. RY10-4 plus DAPT increases apoptosis in both HER2-overexpressing cell lines by two-fold compared to RY10-4 alone, while DAPT alone has no significant effects on apoptosis. In addition, we previously found RY10-4 could inhibit tumor growth through the PI3K/AKT pathway. Here we report that the combination of RY10-4 and DAPT exhibit additive suppression on AKT phosphorylation, contributing to the anti-cancer effects. In an animal model, this combination therapy inhibits the growth of SKBR3 tumor xenografts in nude mice to a greater extent than treatment with either reagent alone. These results indicate that the aberrant activation of Notch signaling impedes the inhibitory effect of RY10-4 on HER2-amplified cell proliferation. Furthermore, these adverse effects can be prevented by treatment combining RY10-4 with a Notch pathway inhibitor. PMID:26716652

  16. MIRADAS: The Multi-Object R=22K Near-IR Spectropolarimeter for the 10.4-meter GTC

    NASA Astrophysics Data System (ADS)

    Eikenberry, Stephen S.; MIRADAS Consortium

    2016-01-01

    The Mid-resolution InfRAreD Astronomical Spectrograph (MIRADAS), a near-infrared multi-object echelle spectrograph operating at spectral resolution R=22,000 over the 1-2.5µm bandpass, is being developed by an international consosrtium for the 10.4-meter Gran Telescopio Canarias (GTC). The MIRADAS consortium includes the University of Florida, Universidad de Barcelona, Universidad Complutense de Madrid, Instituto de Astrofísica de Canarias, as well as industrial partners in the US and Europe. MIRADAS completed its Final Design Review in mid-2015, and is currently undergoing fabrication, with planned first light in 2018/2019. In this paper, we review the overall science drivers and system design for MIRADAS, including key technologies such as cryogenic robotic probe arms, macroslicer mini-IFUs, full Stokes polarimetry, and a highly flexible observing configuration.

  17. RY10-4 Inhibits the Proliferation of Human Hepatocellular Cancer HepG2 Cells by Inducing Apoptosis In Vitro and In Vivo

    PubMed Central

    Zhang, Xuenong; Wang, Yanyan; Han, Shishi; Xiang, Huiyao; Peng, Yan; Wu, Yinghua; Pan, Songwei; Zhang, Ye; Ruan, Jinlan

    2016-01-01

    This study aimed to investigate the anti-tumor activity of RY10-4, a small molecular that was designed and synthesized based on the structure of protoapigenone. A previous screening study showed that RY10-4 possessed anti-proliferative effects against HepG2 human hepatocellular carcinoma cells. However, the full range of RY10-4 anti-cancer effects on liver tumors and the underlying mechanisms have not been identified. Herein, employing flow cytometry, and Western blot analysis, we demonstrate that RY10-4 can induce cell cycle arrest, intracellular reactive oxygen species (ROS) production and apoptosis in HepG2 cells. In HepG2 cell xenograft tumor model, RY10-4 significantly inhibited the growth of tumors and induced apoptosis in tumor cells, with little side effects. Moreover, RY10-4 caused the suppression of STAT3 activation, which may be involved the apoptosis induction. In addition, RY10-4 inhibited the proliferation of Hep3B and HuH-7 human hepatocellular carcinoma cells in a concentration-dependent manner. Taken together, our results suggest that RY10-4 has a great potential to develop as chemotherapeutic agent for liver cancer. PMID:26974964

  18. ExoMol molecular line lists - XIII. The spectrum of CaO

    NASA Astrophysics Data System (ADS)

    Yurchenko, Sergei N.; Blissett, Audra; Asari, Usama; Vasilios, Marcus; Hill, Christian; Tennyson, Jonathan

    2016-03-01

    An accurate line list for calcium oxide is presented covering transitions between all bound ro-vibronic levels from the five lowest electronic states X 1Σ+, A' 1Π, A 1Σ+, a 3Π, and b 3Σ+. The ro-vibronic energies and corresponding wavefunctions were obtained by solving the fully coupled Schrödinger equation. Ab initio potential energy, spin-orbit, and electronic angular momentum curves were refined by fitting to the experimental frequencies and experimentally derived energies available in the literature. Using our refined model we could (1) reassign the vibronic states for a large portion of the experimentally derived energies (van Groenendael A., Tudorie M., Focsa C., Pinchemel B., Bernath P. F., 2005, J. Mol. Spectrosc., 234, 255), (2) extended this list of energies to J = 61-118 and (3) suggest a new description of the resonances from the A 1Σ+-X 1Σ+ system. We used high level ab initio electric dipole moments reported previously (Khalil H., Brites V., Le Quere F., Leonard C., 2011, Chem. Phys., 386, 50) to compute the Einstein A coefficients. Our work is the first fully coupled description of this system. Our line list is the most complete catalogue of spectroscopic transitions available for 40Ca16O and is applicable for temperatures up to at least 5000 K. CaO has yet to be observed astronomically but its transitions are characterized by being particularly strong which should facilitate its detection. The CaO line list is made available in an electronic form as supplementary data to this article and at www.exomol.com.

  19. Dietary fibre concentrate from Chilean algarrobo (Prosopis chilensis (Mol.) Stuntz) pods: purification and characterization.

    PubMed

    Estévez, Ana María; Figuerola, Fernando; Bernuy, Enrique; Sáenz, Carmen

    2014-12-01

    Prosopis species are generally fast-growing, drought-resistant, nitrogen-fixing trees or shrubs. Fruits of Prosopis spp are indehiscent pods, where pericarp is formed by the epicarp, light brown in colour, and fibrous nature; the mesocarp known as pulp, which is rich in sugars; and the endocarp. The aim of this work was to obtain a fibre concentrate from the pods of Prosopis chilensis Mol. (Stuntz) and to determine the chemical, physical, and technological properties of the pod flour (PF) and of a fibre concentrate or pod purified flour (PPF). Acetone, ethanol, and water at different conditions of time and temperature were used in the purification process. PF showed 53.7 g/100 g of total sugar content, 4.2 g/100 g of reducing sugar content, 41.8 g/100 g of total dietary fibre, 35.8 g/100 g of insoluble fibre, and 6.0 g/100 g of soluble fibre content. The PPF has a total sugar content of 3.8 g/100 g, reducing sugar content of 2.2 g/100 g, total dietary fibre content of 80.8 g/100 g, insoluble fibre content of 75.1 g/100 g, and soluble fibre content of 5.7 g/100 g. The scanning electron microscopy analysis showed the existence of voids in the structure of PPF flour, which reveals the efficiency of the purification process with a high decrease in the total sugar content. PMID:24003035

  20. International comparison CCQM-K82: methane in air at ambient level (1800 to 2200) nmol/mol

    NASA Astrophysics Data System (ADS)

    Flores, Edgar; Viallon, Joële; Choteau, Tiphaine; Moussay, Philippe; Wielgosz, Robert I.; Kang, Namgoo; Kim, Byung Moon; Zalewska, Ewelina; H van der Veen, Adriaan (A. M.; Konopelko, Leonid; Wu, Hai; Han, Qiao; Rhoderick, George; Guenther, Franklin R.; Watanabe, Takuro; Shimosaka, Takuya; Kato, Kenji; Hall, Brad; Brewer, Paul

    2015-01-01

    The CCQM-K82 comparison was designed to evaluate the degrees of equivalence of NMI capabilities for methane in air primary reference mixtures in the range (1800 to 2200) nmol/mol. The balance gas for the standards was either scrubbed dry real air or synthetic air. CH4 in air standards have been produced by a number of laboratories for many years, with more recent developments focused on standards at atmospheric measurement concentrations and aimed at obtaining agreement between independently produced standards. A comparison of the differences in primary gas standards for methane in air was previously performed in 2003 (CCQM-P41 Greenhouse gases. 1 and 2) with a standard deviation of results around the reference value of 30 nmol/mol and 10 nmol/mol for a more limited set of standards. This can be contrasted with the level of agreement required from field laboratories routinely measuring atmospheric methane levels, set by Data Quality Objectives (DQO) established by the World Meteorological Organization (WMO) to reflect the scientifically desirable level of compatibility for CH4 measurements at the global scale, currently set at 2 nmol/mol (1 sigma). The measurements of this key comparison took place from May 2012 to June 2012. Eight laboratories took part in this comparison coordinated by the BIPM and NIST. Key comparison reference values were calculated based on Cavity Ring Down Spectroscopy Measurements performed at the BIPM, combined with participant's gravimetric values to identify a consistent set of standards. Regression analysis allowed predicted values for each standard to be calculated which acted as the KCRVs. In this comparison reported standard uncertainties by participants ranged from 0.50 nmol/mol to 2.4 nmol/mol and the uncertainties of individual KCRVs ranged from 0.68 nmol/mol to 0.71 nmol/mol. The standard deviation of the ensemble of standards about the KCRV value was 1.70 nmol/mol. This represents a greater than tenfold improvement in the level

  1. Phase transformation and wear studies of plasma sprayed yttria stabilized zirconia coatings containing various mol% of yttria

    SciTech Connect

    Aruna, S.T. Balaji, N.; Rajam, K.S.

    2011-07-15

    Plasma sprayable grade zirconia powders doped with various mol% of yttria (0, 2, 3, 4, 6, 8 and 12 mol%) were synthesized by a chemical co-precipitation route. The coprecipitation conditions were adjusted such that the powders possessed good flowability in the as calcined condition and thus avoiding the agglomeration step like spray drying. Identical plasma spray parameters were used for plasma spraying all the powders on stainless steel plates. The powders and plasma sprayed coatings were characterized by X-ray diffractometry, Scanning Electron Microscopy and Raman spectroscopy. Zirconia powders are susceptible to phase transformations when subjected to very high temperatures during plasma spraying and XRD is insensitive to the presence of some non crystalline phases and hence Raman spectroscopy was used as an important tool. The microstructure of the plasma sprayed coatings showed a bimodal distribution containing fully melted and unmelted zones. The microhardness and wear resistance of the plasma sprayed coatings were determined. Among the plasma sprayed coatings, 3 mol% yttria stabilized zirconia coating containing pure tetragonal zirconia showed the highest wear resistance. - Research Highlights: {yields} Preparation plasma sprayable YSZ powders without any agglomeration process and plasma spraying {yields} Phase transformation studies of plasma sprayed YSZ coatings by XRD and Raman spectroscopy {yields} Microstructure of the plasma sprayed coatings exhibited bimodal distribution {yields} Plasma sprayed 3 mol% YSZ coating exhibited the highest wear resistance {yields} Higher wear resistance is due to the higher fracture toughness of tetragonal 3 mol% YSZ phase.

  2. High temperature embrittlement caused by traces of calcium or strontium in an Al-5.5 mol% Mg alloy

    SciTech Connect

    Horikawa, Keitaro; Kuramoto, Shigeru; Kanno, Motohiro

    1998-09-04

    Al-5--10mol%Mg alloys are now being developed for automotive parts since they have good formability. However, an alloy containing magnesium of more than 5mol% has poor hot rolling characteristics. It has been reported that an Al-5.5mol%Mg alloy shows high temperature embrittlement (HTE) based on intergranular fracture at around 300 C depending on strain rate. This embrittlement is considered to be closely related to the unfavorable hot rolling characteristics of the Al-Mg alloy. One of the present authors reported recently that this embrittlement is caused by a trace amount of sodium of only of only 0.6mass ppm (0.7mol ppm) in a coarse-grained Al-5.5mol%Mg alloy produced using high purity ingots. Although numerous studies have been made on the effect of sodium, little is known about the effect of alkali and alkaline-earth elements other than sodium. However, unusual impurities may inevitably creep in the recycling process in future. For example, it is reported that the Al-Mg alloy is contaminated by calcium through the ceramic tube filter using during melting and casting, and strontium is used commercially as an additional element in Al-Si alloys. Hence, aluminum alloys made using recycled stock may be contaminated at least by calcium and strontium. The purpose of this study is to determine the effect of traces of calcium or strontium on hot ductility of an Al-5.5mol%Mg alloy.

  3. A signature of transience in bedrock river incision rates over timescales of 10(4)-10(7) years.

    PubMed

    Finnegan, Noah J; Schumer, Rina; Finnegan, Seth

    2014-01-16

    Measured rates of river incision into bedrock are commonly interpreted as proxies for rates of rock uplift (see refs 1 and 2, for example) and indices of the strength of climatic forcing of erosion over time (see refs 3 and 4, for example). This approach implicitly assumes that river incision rates are in equilibrium with external forcings over a wide range of timescales. Here we directly test this assumption by examining the temporal scaling of bedrock river incision from 155 independent measurements of river incision compiled from 14 sites. Of these sites, 11 exhibit a negative power-law dependence of bedrock river incision rate on measurement interval, a relationship that is apparent over timescales of 10(4)-10(7) years and is independent of tectonic and geomorphic setting. Thus, like rates of sediment accumulation, rates of river incision into bedrock exhibit non-steady-state behaviour even over very long measurement intervals. Non-steady-state behaviour can be explained by episodic hiatuses in river incision triggered by alluvial deposition, if such hiatuses have a heavy-tailed length distribution. Regardless of its cause, the dependence of incision rate on measurement interval complicates efforts to infer tectonic or climatic forcing from changes in rates of river incision over time or from comparison of rates computed over different timescales. PMID:24429636

  4. Compositional study of asteroids in the Erigone collisional family using visible spectroscopy at the 10.4 m GTC

    NASA Astrophysics Data System (ADS)

    Morate, David; de León, Julia; De Prá, Mário; Licandro, Javier; Cabrera-Lavers, Antonio; Campins, Humberto; Pinilla-Alonso, Noemí; Alí-Lagoa, Víctor

    2016-02-01

    Two primitive near-Earth asteroids, (101955) Bennu and (162173) Ryugu, will be visited by a spacecraft with the aim of returning samples back to Earth. Since these objects are believed to originate in the inner main belt primitive collisional families (Erigone, Polana, Clarissa, and Sulamitis) or in the background of asteroids outside these families, the characterization of these primitive populations will enhance the scientific return of the missions. The main goal of this work is to shed light on the composition of the Erigone collisional family by means of visible spectroscopy. Asteroid (163) Erigone has been classified as a primitive object, and we expect the members of this family to be consistent with the spectral type of the parent body. We have obtained visible spectra (0.5-0.9 μm) for 101 members of the Erigone family, using the OSIRIS instrument at the 10.4 m Gran Telescopio Canarias. We found that 87% of the objects have typically primitive visible spectra consistent with that of (163) Erigone. In addition, we found that a significant fraction of these objects (~50%) present evidence of aqueous alteration.

  5. Parallel vortex shedding at Re ;{=}{bm {O(10(4)}) a transverse control cylinder technique approach

    NASA Astrophysics Data System (ADS)

    Luo, S. C.; Xia, H. M.

    2005-10-01

    In the present studies, the effects of the end conditions of a circular cylinder on its wake at a fairly high Reynolds number of Re = 1.57× 10(4) were studied. The transverse control cylinder technique (TCCT) was previously reported to be able to induce parallel vortex shedding at Re = O(10(2)) . In the present work, experimental results showed that the TCCT is still effective in inducing parallel vortex shedding at Re = O(10(4)) . Initially, before the inclusion of the control cylinders, vortices shed by the main cylinder were curved (all shapes referred to are time-averaged shapes) owing to the influence of the cylinder end conditions. Later, two larger control cylinders of diameter D were included and were located normal and upstream of the main cylinder near its ends to change its end conditions. By manipulating the control distance (the gap between the control cylinders and the main cylinder), different vortex-shedding patterns could be induced. With both control cylinders fixed at the optimum control distance of L_1 = L_2 = L_0 = 1.26D, the main cylinder was induced to shed parallel vortices. For the cases of curved vortex shedding (without control cylinders) and parallel vortex shedding (with control cylinders at the optimum distance of L_1 = L_2 = L_0 = 1.26D), various aerodynamic parameters of the main cylinder were measured and compared. Results showed that the inclusion of the control cylinders speeded up the flow velocity at the ends of the main cylinder and led to a more uniform pressure distribution over the central span of the main cylinder, which finally resulted in parallel vortex shedding. Aerodynamic parameters such as drag coefficient and Strouhal number associated with parallel vortex shedding were found to be larger than their curved shedding counterparts. However, extra caution should be exercised in interpreting their implications as these data were under the influence of additional wind-tunnel blockage caused by the presence of the control

  6. New efficient ligand for sub-mol % copper-catalyzed C-N cross-coupling reactions running under air.

    PubMed

    Larsson, Per-Fredrik; Astvik, Peter; Norrby, Per-Ola

    2012-01-01

    A new efficient ligand, N,N''-dimethyldiethylene triamine (DMDETA), has been synthesized and evaluated for sub-mol % copper-catalyzed C-N cross-coupling reactions. The efficiency of the ligand was determined by kinetic methods. DMDETA proved to display efficiency similar to DMEDA and, in addition, the resulting catalyst was tolerant to air. PMID:23209530

  7. New efficient ligand for sub-mol % copper-catalyzed C–N cross-coupling reactions running under air

    PubMed Central

    Larsson, Per-Fredrik; Astvik, Peter

    2012-01-01

    Summary A new efficient ligand, N,N’’-dimethyldiethylene triamine (DMDETA), has been synthesized and evaluated for sub-mol % copper-catalyzed C–N cross-coupling reactions. The efficiency of the ligand was determined by kinetic methods. DMDETA proved to display efficiency similar to DMEDA and, in addition, the resulting catalyst was tolerant to air. PMID:23209530

  8. [The nuclear matrix proteins (mol. mass 38 and 50 kDa) are transported by chromosomes in mitosis].

    PubMed

    Murasheva, M I; Chentsov, Iu S

    2010-01-01

    It was shown by immunofluorescence method that serum M68 and serum K43 from patients with autoimmune disease stain interphase nuclei and periphery of mitotic chromosomes of pig kidney cells. Western blotting reveals the polypeptide with mol. mass of 50 kDa in serum M68, and the polypeptide with mol. mass of 38 kDa in serum K43. In the nuclear protein matrix, the antibodies to protein with mol. mass of 38 kDa stained only nucleolar periphery, while the antibodies to the protein with mol. mass of 50 kDa stained both the nucleolar periphery and all the interphase nucleus. It shows that among all components of nuclear protein matrix (lamina, internuclear network, residual nucleoli) only nucleolar periphery contains the 38 kDa protein, while the 50 kDa protein is a part of residual nucleolar periphery and takes part in nuclear protein network formation. In the interphase cells, both proteins were in situ localized in the nuclei, but one of them with mol. mass of 50 kDa was in the form of small clearly outlined granules, while the other (38 kDa) was in the form of small bright granules against the background of diffusely stained nuclei. Both proteins were also revealed as continuous ring around nucleolar periphery. During all mitotic stages, the 50 kDa protein was seen on the chromosomal periphery as a cover, and the 38 kDa protein formed separate fragments and granules around them. After nuclear and chromosome decondensation induced by hypotonic treatment, both antibodies stain interphase nuclei in diffuse manner, but in mitotic cells they stained the surface of the swollen chromosomes. The polypeptide with mol. mass of 50 kDa maintained strong connection with chromosome periphery both in norm and under condition of decondensation induced by hypotonic treatment and at subsequent recondensation in isotonic medium. In contrast, the protein with mol. mass of 38 kDa partially lost the contact with a chromosome during recondensation appearing also in the form of granules in

  9. Compositional study of asteroids in the Erigone collisional family using visible spectroscopy at the 10.4m GTC

    NASA Astrophysics Data System (ADS)

    Morate, David; de León, Julia; De Prá, Mário; Licandro, Javier; Cabrera-Lavers, Antonio; Campins, Humberto; Pinilla-Alonso, Noemí; Alí-Lagoa, Víctor

    2015-11-01

    Asteroid families are formed by the fragments produced by the disruption of a common parent body (Bendjoya & Zappalà 2002). Primitive asteroids in the solar system are believed to have undergone less thermal processing than the S-complex asteroids. Thus, study of primitive asteroid families provides information about the solar system formation period. The Erigone collisional family, together with other three families (Polana, Clarissa and Sulamitis), are believed to be the origin of the two primitive Near-Earth asteroids that are the main targets of the NASA’s OSIRIS-REx ((101955) Bennu) and JAXA’s Hayabusa 2 ((162173) 1999 JU3) missions (Campins et al. 2010; Campins et al. 2013; Lauretta et al. 2010; Tsuda et al. 2013). These spacecrafts will visit the asteroids, and a sample of their surface material will be returned to Earth. Understanding of the families that are considered potential sources will enhance the scientific return of the missions. The main goal of the work presented here is to characterize the Erigone collisional family. Asteroid (163) Erigone has been classified as a primitive object (Bus 1999; Bus & Binzel 2002), and we expect the members of this family to be consistent with the spectral type of the parent body. We have obtained visible spectra (0.5-0.9 μm) for 101 members of the Erigone family, using the OSIRIS instrument at the 10.4m Gran Telescopio Canarias. We performed a taxonomical classification of these asteroids, finding that the number of primitive objects in our sample is in agreement with the hypothesis of a common parent body. In addition, we have found a significant fraction of asteroids in our sample that present evidences of aqueous alteration. Study of aqueous alterations is important, as it can give information on the heating processes of the early Solar System, and for the associated astrobiological implications (it has been suggested that the Earth’s present water supply was brought here by asteroids, instead of comets

  10. mol2chemfig, a tool for rendering chemical structures from molfile or SMILES format to LATE X code

    PubMed Central

    2012-01-01

    Displaying chemical structures in LATE X documents currently requires either hand-coding of the structures using one of several LATE X packages, or the inclusion of finished graphics files produced with an external drawing program. There is currently no software tool available to render the large number of structures available in molfile or SMILES format to LATE X source code. We here present mol2chemfig, a Python program that provides this capability. Its output is written in the syntax defined by the chemfig TE X package, which allows for the flexible and concise description of chemical structures and reaction mechanisms. The program is freely available both through a web interface and for local installation on the user’s computer. The code and accompanying documentation can be found at http://chimpsky.uwaterloo.ca/mol2chemfig. PMID:23031664

  11. Using a PyMOL Activity to Reinforce the Connection between Genotype and Phenotype in an Undergraduate Genetics Laboratory

    PubMed Central

    Simmons, Alexandra D.; Nguyen, Thao K. T.; Follis, Jack L.; Ribes-Zamora, Albert

    2014-01-01

    With the purpose of developing an activity that would help clarify genetic concepts related to the connection between genotype and phenotype and the nature of mutations, we designed a three hour teaching module using the PyMol software. The activity starts with two pre-laboratory assignments, one to learn how to use PyMol and the other to read about a specific protein or protein family. During the laboratory students are given instructions where and how to find additional information on a specific disease and its causal mutations in order to prepare a 10-minute, in-class presentation. Using a post activity, anonymous quiz, we found a statistically significant different grade distribution in students that participated in the PyMol activity relative to a control group. We also found a significant improvement in the student’s comprehension when answering questions regarding the nature of mutations and protein structure. This demonstrates the utility of this simulation activity as a vehicle to improve student’s understanding of specific key genetic concepts. PMID:25461967

  12. Preparation of TiO2 Nanocrystallite Powders Coated with 9 mol% ZnO for Cosmetic Applications in Sunscreens

    PubMed Central

    Ko, Horng-Huey; Chen, Hui-Ting; Yen, Feng-Ling; Lu, Wan-Chen; Kuo, Chih-Wei; Wang, Moo-Chin

    2012-01-01

    The preparation of TiO2 nanocrystallite powders coated with and without 9 mol% ZnO has been studied for cosmetic applications in sunscreens by a co-precipitation process using TiCl4 and Zn(NO3)2·6H2O as starting materials. XRD results show that the phases of anatase TiO2 and rutile TiO2 coexist for precursor powders without added ZnO (T-0Z) and calcined at 523 to 973 K for 2 h. When the T-0Z precursor powders are calcined at 1273 K for 2 h, only the rutile TiO2 appears. In addition, when the TiO2 precursor powders contain 9 mol% ZnO (T-9Z) are calcined at 873 to 973 K for 2 h, the crystallized samples are composed of the major phase of rutile TiO2 and the minor phases of anatase TiO2 and Zn2Ti3O8. The analyses of UV/VIS/NIR spectra reveal that the absorption of the T-9Z precursor powders after being calcined has a red-shift effect in the UV range with increasing calcination temperature. Therefore, the TiO2 nanocrystallite powders coated with 9 mol% ZnO can be used as the attenuate agent in the UV-A region for cosmetic applications in sunscreens. PMID:22408415

  13. PyMod: sequence similarity searches, multiple sequence-structure alignments, and homology modeling within PyMOL

    PubMed Central

    2012-01-01

    Background In recent years, an exponential growing number of tools for protein sequence analysis, editing and modeling tasks have been put at the disposal of the scientific community. Despite the vast majority of these tools have been released as open source software, their deep learning curves often discourages even the most experienced users. Results A simple and intuitive interface, PyMod, between the popular molecular graphics system PyMOL and several other tools (i.e., [PSI-]BLAST, ClustalW, MUSCLE, CEalign and MODELLER) has been developed, to show how the integration of the individual steps required for homology modeling and sequence/structure analysis within the PyMOL framework can hugely simplify these tasks. Sequence similarity searches, multiple sequence and structural alignments generation and editing, and even the possibility to merge sequence and structure alignments have been implemented in PyMod, with the aim of creating a simple, yet powerful tool for sequence and structure analysis and building of homology models. Conclusions PyMod represents a new tool for the analysis and the manipulation of protein sequences and structures. The ease of use, integration with many sequence retrieving and alignment tools and PyMOL, one of the most used molecular visualization system, are the key features of this tool. Source code, installation instructions, video tutorials and a user's guide are freely available at the URL http://schubert.bio.uniroma1.it/pymod/index.html PMID:22536966

  14. Efectos de la irradiación iónica en hielos de moléculas carbonadas

    NASA Astrophysics Data System (ADS)

    Satorre, M. A.

    En Astrofísica podemos encontrar numerosos contextos en los cuales se observan moléculas en estado sólido que, en condiciones estándar de presión y temperatura, se encontrarían como gases o líquidos. Dichas moléculas se denominan hielos y han sido observadas en nubes densas del medio interestelar, en envolturas circumestelares, en satélites del Sistema Solar, en cometas, etc. Los hielos pueden ser alterados en su composición química debido a diversos factores como por ejemplo variaciones de temperatura o aportes energéticos por parte de la irradiación, ya sea tanto de fotones ultravioleta como de iones. Dependiendo del escenario astrofísico que analicemos, unos factores cobran más importancia que otros. Los experimentos de laboratorio muestran el efecto que produce sobre la composición de los hielos la irradiación iónica, en particular sobre los que contenían alguna molécula con átomos de carbono. Dicha composición se analiza con espectroscopía IR en el rango de 2 a ˜ 25μ m. La aplicabilidad de los resultados de los experimentos es distinta dependiendo de la composición química inicial de los hielos, del tipo de ion utilizado y de la dosis total de irradiación. Existen efectos generales de la irradiación sobre la materia en los experimentos de relevancia astrofísica como son: - la formación de nuevas moléculas, que pueden incluir o no el ion incidente; - la progresiva pérdida de hidrógeno (carbonización) cuando irradiamos muestras que originalmente contienen una determinada relación carbono/hidrógeno; - la variación de la temperatura de sublimación que presentan algunos hielos. Esto puede suceder tanto en hielos que estaban presentes antes de la irradiación como en hielos formados por ésta. Se presentará el papel del ion en la formación de nuevas moléculas a partir de las que originalmente se encontraban en el hielo. Al penetrar en él, el ion provoca distintos procesos como rotura de enlaces y excitaciones electr

  15. SERS of meso-droplets supported on superhydrophobic wires allows exquisitely sensitive detection of dipicolinic acid, an anthrax biomarker, considerably below the infective dose.

    PubMed

    Cheung, Melody; Lee, Wendy W Y; Cowcher, David P; Goodacre, Royston; Bell, Steven E J

    2016-08-01

    Surface-enhanced Raman measurements of <1 μL analyte/colloid meso-droplets on superhydrophobic wires with hydrophilic tips allowed dipicolinic acid, a spore biomarker for Bacillus anthracis (anthrax), to be detected at 10(-6) mol dm(-3). This is equivalent to 18 spores, significantly below the infective dose of 10(4) spores and 2 orders of magnitude better than previous measurements. PMID:27432481

  16. Hydroxyapatite crystallization in the presence of acetaminophen

    NASA Astrophysics Data System (ADS)

    Mangood, A.; Malkaj, P.; Dalas, E.

    2006-05-01

    The effect of acetaminophen; a widely used analgesic and fever reducing medicine; in supersaturated solutions of calcium phosphate was investigated under plethostatic conditions, at 37 °C, 0.15 M NaCl, pH 7.40. The rates of crystal growth measured in the presence of acetaminophen 1.654×10 -4 mol dm -3 to 6.616×10 -4 mol dm -3 were reduced by 43% to 79%, respectively. The inhibition effect on the crystal growth rate may be explained through adsorption onto the active growth sites. Kinetic analysis suggested Langmuir-type adsorption of acetaminophen on the HAP surface with a affinity value of 2.4×10 -4 dm 3 mol -1, for the substrate in the concentration range investigated. The electrophoretic mobility measurements showed that in the presence of acetaminophen the charge of the acetaminophen covered HAP particles was shifted to more negative values as compared to bare HAP. In the presence of acetaminophen no changes observed in the HAP overgrown morphology or in the apparent order of crystallization.

  17. 3d-modelling workflows for trans-nationally shared geological models - first approaches from the project GeoMol

    NASA Astrophysics Data System (ADS)

    Rupf, Isabel

    2013-04-01

    To meet the EU's ambitious targets for carbon emission reduction, renewable energy production has to be strongly upgraded and made more efficient for grid energy storage. Alpine Foreland Basins feature a unique geological inventory which can contribute substantially to tackle these challenges. They offer a geothermal potential and storage capacity for compressed air, as well as space for underground storage of CO2. Exploiting these natural subsurface resources will strongly compete with existing oil and gas claims and groundwater issues. The project GeoMol will provide consistent 3-dimensional subsurface information about the Alpine Foreland Basins based on a holistic and transnational approach. Core of the project GeoMol is a geological framework model for the entire Northern Molasse Basin, complemented by five detailed models in pilot areas, also in the Po Basin, which are dedicated to specific questions of subsurface use. The models will consist of up to 13 litho-stratigraphic horizons ranging from the Cenozoic basin fill down to Mesozoic and late Paleozoic sedimentary rocks and the crystalline basement. More than 5000 wells and 28 000 km seismic lines serve as input data sets for the geological subsurface model. The data have multiple sources and various acquisition dates, and their interpretations have gone through several paradigm changes. Therefore, it is necessary to standardize the data with regards to technical parameters and content prior to further analysis (cf. Capar et al. 2013, EGU2013-5349). Each partner will build its own geological subsurface model with different software solutions for seismic interpretation and 3d-modelling. Therefore, 3d-modelling follows different software- and partner-specific workflows. One of the main challenges of the project is to ensure a seamlessly fitting framework model. It is necessary to define several milestones for cross border checks during the whole modelling process. Hence, the main input data set of the

  18. Classification of a Haemophilus influenzae ABC Transporter HI1470/71 through Its Cognate Molybdate Periplasmic Binding Protein, MolA

    SciTech Connect

    Tirado-Lee, Leidamarie; Lee, Allen; Rees, Douglas C.; Pinkett, Heather W.

    2014-10-02

    molA (HI1472) from H. influenzae encodes a periplasmic binding protein (PBP) that delivers substrate to the ABC transporter MolB{sub 2}C{sub 2} (formerly HI1470/71). The structures of MolA with molybdate and tungstate in the binding pocket were solved to 1.6 and 1.7 {angstrom} resolution, respectively. The MolA-binding protein binds molybdate and tungstate, but not other oxyanions such as sulfate and phosphate, making it the first class III molybdate-binding protein structurally solved. The {approx}100 {mu}M binding affinity for tungstate and molybdate is significantly lower than observed for the class II ModA molybdate-binding proteins that have nanomolar to low micromolar affinity for molybdate. The presence of two molybdate loci in H. influenzae suggests multiple transport systems for one substrate, with molABC constituting a low-affinity molybdate locus.

  19. Classification of a Haemophilus influenzae ABC transporter HI1470/71 through its cognate molybdate periplasmic binding protein, MolA.

    PubMed

    Tirado-Lee, Leidamarie; Lee, Allen; Rees, Douglas C; Pinkett, Heather W

    2011-11-01

    molA (HI1472) from H. influenzae encodes a periplasmic binding protein (PBP) that delivers substrate to the ABC transporter MolB(2)C(2) (formerly HI1470/71). The structures of MolA with molybdate and tungstate in the binding pocket were solved to 1.6 and 1.7 Å resolution, respectively. The MolA-binding protein binds molybdate and tungstate, but not other oxyanions such as sulfate and phosphate, making it the first class III molybdate-binding protein structurally solved. The ∼100 μM binding affinity for tungstate and molybdate is significantly lower than observed for the class II ModA molybdate-binding proteins that have nanomolar to low micromolar affinity for molybdate. The presence of two molybdate loci in H. influenzae suggests multiple transport systems for one substrate, with molABC constituting a low-affinity molybdate locus. PMID:22078568

  20. Synthesis, EPR and luminescent properties of YAlO3:Fe3+ (0.1-0.9 mol%) nanopowders

    NASA Astrophysics Data System (ADS)

    Premkumar, H. B.; Nagabhushana, H.; Sharma, S. C.; Daruka Prasad, B.; Nagabhushana, B. M.; Rao, J. L.; Chakradhar, R. P. S.

    A simple and inexpensive combustion method was used to prepare Fe3+ doped YAlO3 perovskite within few minutes at low temperature (400 ± 10 °C). This might be useful in lowering the cost of the material. The final products were well characterized by various spectroscopic techniques such as PXRD, SEM, TEM, FTIR and UV-Visible. The average crystallite size was estimated from the broadening of the PXRD peaks and found to be in the range 45-90 nm, the results were in good agreement with the W-H plots and TEM. The crystallites show dumbbell shape, agglomerated particles with different size. The TL glow curves of 1-5 kGy γ-irradiated YAlO3:Fe3+ (0.1 mol%) nanopowder warmed at a heating rate of 3 °C s-1 records a single glow peak at ∼260 °C. The kinetic parameters namely activation energy (E), order of kinetics (b) and frequency factor (s) were determined at different gamma doses using the Chens glow peak shape method and the results were discussed in detail. The photoluminescence spectra for Fe3+ (0.1-0.9 mol%) doped YAlO3 records the lower energy band at 720 nm (4T1 (4G) → 6A1 (6S)) and the intermediate band located at 620 nm (4T2 (4G) → 6A1 (6S)) with the excitation of 378 nm. The higher energy band located at 514 nm was associated to 4E + 4A1 (4G) → 6A1 (6S) transition. The resonance signals at g values 7.6, 4.97, 4.10, 2.94, 2.33 and 1.98 were observed in EPR spectra of Fe3+ (0.1-0.9 mol%) doped YAlO3 recorded at room temperature. The g values indicate that the iron ions were in trivalent state and distorted octahedral site symmetry was observed.

  1. Synthesis, EPR and luminescent properties of YAlO3:Fe3+ (0.1-0.9mol%) nanopowders.

    PubMed

    Premkumar, H B; Nagabhushana, H; Sharma, S C; Daruka Prasad, B; Nagabhushana, B M; Rao, J L; Chakradhar, R P S

    2014-05-21

    A simple and inexpensive combustion method was used to prepare Fe(3+) doped YAlO3 perovskite within few minutes at low temperature (400±10°C). This might be useful in lowering the cost of the material. The final products were well characterized by various spectroscopic techniques such as PXRD, SEM, TEM, FTIR and UV-Visible. The average crystallite size was estimated from the broadening of the PXRD peaks and found to be in the range 45-90nm, the results were in good agreement with the W-H plots and TEM. The crystallites show dumbbell shape, agglomerated particles with different size. The TL glow curves of 1-5kGy γ-irradiated YAlO3:Fe(3+) (0.1mol%) nanopowder warmed at a heating rate of 3°Cs(-1) records a single glow peak at ∼260°C. The kinetic parameters namely activation energy (E), order of kinetics (b) and frequency factor (s) were determined at different gamma doses using the Chens glow peak shape method and the results were discussed in detail. The photoluminescence spectra for Fe(3+) (0.1-0.9mol%) doped YAlO3 records the lower energy band at 720nm ((4)T1 (4G)→(6)A1 (6S)) and the intermediate band located at 620nm ((4)T2 ((4)G)→(6)A1 (6S)) with the excitation of 378nm. The higher energy band located at 514nm was associated to (4)E+(4)A1 ((4)G)→(6)A1 (6S) transition. The resonance signals at g values 7.6, 4.97, 4.10, 2.94, 2.33 and 1.98 were observed in EPR spectra of Fe(3+) (0.1-0.9mol%) doped YAlO3 recorded at room temperature. The g values indicate that the iron ions were in trivalent state and distorted octahedral site symmetry was observed. PMID:24607471

  2. Excitação e fotoabsorção de moléculas interestelares no ultra violeta

    NASA Astrophysics Data System (ADS)

    Rodrigues, A. M. F.; Boechat-Roberty, H. M.; Souza, G. B.; Turci, C. C.

    2003-08-01

    O estudo dos processos de excitação, fotoabsorção e ionização molecular nas nuvens interestelar, permite a análise dos processos químicos, como a formação e destruição de moléculas, até mesmo daquelas que dão origem à vida. Acredita-se que as moléculas como CS2, NH3, CO2 e N2O estão presentes nas nuvens onde são formadas as estrelas e seus sistemas planetários. Estas moléculas são congeladas na superfície de objetos densos, como aqueles encontrados na Nuvem de Oort do nosso Sistema Solar. Quando esses objetos (cometas) desprendem-se dessa região, aproximam-se do Sol, sofrem a interação da radição Ultra Violeta (UV), passam à fase gasosa e são bombardeados por íons e elétrons presentes nos ventos solares. Obtivemos os espectros de fotoabsorção do CS2, NH3 e N2O na faixa do UV, convertendo espectros de Perda de Energia de Elétrons, medidos no menor ângulo de espalhamento e na energia de impacto de 1000 eV. Destes espectros determinamos os valores de força de oscilador (f) e de seção de choque absolutas na faixa de 500 a 2000 Å. Para tal, estudamos e comparamos dois diferentes métodos de conversão. Neste trabalho também geramos muitos dados moleculares como, valores absolutos de seção de choque elástica em função do ângulo de espalhamento e a distribuição de força do oscilador generalizada (df/dE) em função da energia de excitação para diversos ângulos de espalhamento. Comparando nossos espectros de fotoabsorção com o espectro da atmosfera de Júpiter, obtido pelo Telescópio Espacial Hubble, logo após o impacto do cometa Shoemaker-Levy 9, confirmamos a presença do CS2 e da amônia.

  3. Low temperature and magnetic field behaviour of the (Cr{sub 84}Re{sub 16}){sub 89.6}V{sub 10.4} alloy

    SciTech Connect

    Jacobs, B. S. Sheppard, C. J.; Prinsloo, A. R. E.; Lodya, L.

    2014-05-07

    Measurements of the temperature (T) dependence of the magnetic susceptibility (χ) and electrical resistance (R) on an antiferromagnetic (AFM) (Cr{sub 84}Re{sub 16}){sub 89.6}V{sub 10.4} alloy are reported in order to probe the existence of quantum critical behaviour (QCB) utilizing static magnetic fields (H) as a tuning parameter. The results indicate that an increase in H suppresses T{sub N} in such a way that it varies exponentially with increasing H. R(T) measurements show evidence of possible superconducting (SC) behaviour below 1 K at H = 0 T. These results therefore indicate the coexistence of the AFM and SC phases in the (Cr{sub 84}Re{sub 16}){sub 89.6}V{sub 10.4} alloy.

  4. Bilateral key comparison CCM.P-K3.1 for absolute pressure measurements from 3 × 10-6 Pa to 9 × 10-4 Pa

    NASA Astrophysics Data System (ADS)

    Fedchak, J. A.; Bock, Th; Jousten, K.

    2014-01-01

    This report describes the bilateral key comparison CCM.P-K3.1 between the National Institute of Standards and Technology (NIST) and Physikalisch-Technische Bundesanstalt (PTB) for absolute pressure in the range from 3 × 10-6 Pa to 9 × 10-4 Pa. This comparison was a follow-up to the comparison CCM.P-K3. Two ionization gauges and two spinning rotor gauges (SRGs) were used as the transfer standards for the comparison. The SRGs were used to compare the standards at a pressure of 9 × 10-4 Pa and to normalize the ionization gauge readings. The two ionization gauges were used to compare the standards in the pressure range of from 3 × 10-6 Pa to 3 × 10-4 Pa. Both laboratories used dynamic expansion chambers as standards in the comparison. The two labs showed excellent agreement with each other and with the CCM.P-K3 key comparison reference value (KCRV) over the entire range. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

  5. The oxidation of methanol and 2-propanol by potassium peroxodisulphate in aqueous solution: Free-radical chain mechanisms elucidated by radiation-chemical techniques

    NASA Astrophysics Data System (ADS)

    Schuchmann, Heinz-Peter; von Sonntag, Clemens

    The γ-radiolysis of methanol or 2-propanol in the presence of potassium peroxodisulphate has been studied in aqueous solution. These chain reactions have been followed by product analysis at various reactant concentrations. A curve-fitting procedure has been applied in order to extract mechanistic and kinetic information from product yield data. In these alcohols, the reaction chain consists mainly of reactions (10), (11) and (3), (4), respectively. SO -4˙+ CH3OH→ .CH2OH+H ++ SO2-4k=8×10 6dm 3mol -1s -1 (10) .CH2OH+ S2O2-8→ CH2O+ SO-4˙+ H++ SO2-4k=7±2×10 4dm 3mol -1s -1 (11) SO-4˙+( CH3) 2CHOH→ .C( CH3) 2OH+ H++ SO2-4k=9×10 7dm 3mol -1s -1 (3) .C( CH3) 2OH+ S2O2-8→( CH3) 2CO+ SO-4˙+ H++ SO2-4k=9±1×10 5dm 3mol -1s -1. (4) The explanation of the data requires inclusion in the mechanisms of the reaction of SO -4 with S 2O 2-8 which leads to the formation of a species (possibly S 2O -48, reaction 14) which in its behaviour toward the substrate resembles, but is less reactive than, the SO -4 (reactions 15 and 25). This mechanistic complication becomes apparent only at low [alcohol]/[S 2O 2-8] ratios. SO-4˙+ S2O2-8→ SO2-4+ S2O-4˙k=1×10 6dm 3mol -1s -1 (14) S2O-4˙+ CH3OH→ S2O2-8+ CH2OH+ H+k=2×10 4dm 3mol -1s -1 (15) S2O-4˙8+( CH3) 2CHOH→ S2O2-8+ .C( CH3) 2OH+ H+3×10 4⩽k⩽1×10 5dm 3mol -1s -1. (25) Further in the 2-propanol system, the inclusion of the bimolecular transformation of the isopropanol β-radical formed in reaction (5) into the α-radical (reaction 28) is necessary. SO-4˙+( CH3) 2CHOH→ .CH2CH( CH3) OH+ H++ SO2-4k=3±2×10 5dm 3mol -1s -1 (5) .CH 2CH(CH 3)OH+(CH 3) 2CHOH→(CH 3) 2CHOH+ .C(CH 3) 2OH k=7±3×10 2dm 3mol -1s -1. (28)

  6. Spherically shaped active transducer based on proton-irradiated vinylidene fluoride-trifluoroethylene 70/30 mol % copolymer

    SciTech Connect

    Lau, S.T.; Chan, H.L.W.; Choy, C.L.; Cheung, W.Y.; Wong, S.P.

    2006-05-15

    Spherically shaped active transducers using proton-irradiated vinylidene fluoride-trifluoroethylene 70/30 mol % copolymer films as the active elements are described. The copolymer films prepared by hot compression molding were irradiated with a high energy proton over a broad dose range (20-250 Mrad). The electrostrictive and piezoelectric responses of the copolymer have been characterized before subsequent transducer fabrication. The performances of the focused transducers constructed with a 4 mm aperture size and epoxy backing were evaluated under dc bias voltages. The transducers with focal lengths of 17.4-19.0 mm and a center frequency of 19 MHz display a broad bandwidth up to 94%. Besides, the transmitting output of the transducers increases with the dc bias voltage. For the copolymer active element irradiated at a proton dose of 107 Mrad, the transducer shows the highest transmitting voltage response of 1.34 kPa/V.

  7. Adhesive evaluation of thin films of LARC-TPI and LARC-TPI with 5 mol % ODA

    NASA Technical Reports Server (NTRS)

    Progar, D. J.

    1986-01-01

    A commercially available LARC-TPI film and an experimentally prepared film of LARC-TPI with 5 mol % of 4,4'-oxydianiline (ODA), designated as LARC-TPI/ODA in the report, supplied by Mitsui Toatsu Chemicals, Incorporated (MTCI), Japan, were evaluated as thermoplastic adhesive films for bonding Ti-6Al-4V. The LARC-TPI/ODA had been shown by MTCI to possess more flow than thermoplastic LARC-TPI and was, therefore, evaluated and compared to the LARC-TPI. Lap shear strength was used to evaluate the materials as adhesives. They were characterized after fracture by determining the glass transition temperature, Tg. The mode of failure was also reported. Thermal exposure at 204C for 500 and 1000 hrs and a 72-hour water-boil were conducted on lap shear specimens prepared with the two adhesive films. Lap shear tests were conducted at RT, 177C, 204C, and 232C before and after exposures.

  8. Combustion synthesis of 5 and 10 mol% YO 1.5 doped ThO 2 powders

    NASA Astrophysics Data System (ADS)

    Purohit, R. D.; Saha, S.; Tyagi, A. K.

    2003-11-01

    Nanocrystalline 5 and 10 mol% YO 1.5 doped ThO 2 powders were prepared by the combustion technique using citric acid as a fuel and nitrates as oxidants. The auto-ignition of the fuel-deficient precursors (prepared by thermal dehydration of the aqueous solutions containing metal nitrates and citric acid in required molar ratio) directly resulted in the well crystalline powders of the desired solid solutions along with traces of carbonaceous material. The as-prepared and calcined powders were characterized by X-ray diffraction (XRD), high-temperature XRD and by their sinterability. The YO 1.5 doped ThO 2 powders when cold-pressed and sintered at 1300 °C for 2 h resulted in ⩾95% of their theoretical densities with nanograin microstructure.

  9. Détection et exaltation de la luminescence de molécules biologiques individuelles en solution

    NASA Astrophysics Data System (ADS)

    Etienne, E.; Lenne, P. F.; Rigneault, H.

    2002-06-01

    La Spectroscopie de Corrélation de Fluorescence (FCS) est une technique d'analyse statistique des fluctuations de luminescence produites par des molécules fluorescentes diffusant librement dans un volume de collection de quelque μm^3. Une limitation fondamentale de la technique provient de l'ouverture numérique limitée des systèmes optiques conventionnels qui ne collectent qu'une faible partie des photons émis. Nous présentons des résultats relatifs à l'augmentation du nombre de photons collectés en utilisant le concept du contrôle de l'émission spontanée par des structures photoniques de type miroir diélectrique.

  10. MLP Tools: a PyMOL plugin for using the molecular lipophilicity potential in computer-aided drug design.

    PubMed

    Oberhauser, Nils; Nurisso, Alessandra; Carrupt, Pierre-Alain

    2014-05-01

    The molecular lipophilicity potential (MLP) is a well-established method to calculate and visualize lipophilicity on molecules. We are here introducing a new computational tool named MLP Tools, written in the programming language Python, and conceived as a free plugin for the popular open source molecular viewer PyMOL. The plugin is divided into several sub-programs which allow the visualization of the MLP on molecular surfaces, as well as in three-dimensional space in order to analyze lipophilic properties of binding pockets. The sub-program Log MLP also implements the virtual log P which allows the prediction of the octanol/water partition coefficients on multiple three-dimensional conformations of the same molecule. An implementation on the recently introduced MLP GOLD procedure, improving the GOLD docking performance in hydrophobic pockets, is also part of the plugin. In this article, all functions of the MLP Tools will be described through a few chosen examples. PMID:24777339

  11. Cristallisation, syncristallisation, et alliages moléculaires entre le lorazépam et l'oxazépam

    NASA Astrophysics Data System (ADS)

    Mascherpa-Corral, D.; Mascherpa, G.; Chauvet, A.

    1993-04-01

    Le polymorphisme et pseudopolymorphisme du lorazépam et oxazépam ont été étudiés par analyse thermique, calorimétrie différentielle à balayage et diffraction de rayons X. Deux formes polymorphes du lorazépam et plusieurs mono et hemisolvates ont été isolés à partir de recristallisation dans divers soivants. Aucun polymorphisme ni solvate n'a été mis en évidence avec l'oxazépam. Les paramètres cristallographiques des phases isolées ont été déterminées. A 160 et 203°C, le lorazépam et l'oxazépam perdent respectivement une molécule d'eau pour donner après réarrangement la quinazolinecarboxaldéhyde correspondante. La syncristallisation des deux benzodiazépines dans le benzène conduit à des alliages moléculaires à miscibilité totale à l'état solide dans tout le domaine de concentration entre l'exazépam el la forme α du lorazépam, elle n'est que partielle avec la forme β. Thermal analysis, differential scanning calorimetry, and X-ray diffraction were carried out to study the polymorphism and pseudopolymorphism of lorazepam and oxazepam. Two polymorphic forms of lorazepam and several mono- or hemisolvates were obtained after recrystallization from various solvents. No polymorphic form or solvate has been found for oxazepam. The crystallographic parameters of these new phases were determined. Lorazepam and oxazepam can lose a molecule of water at 160 and 203°C, respectively, and rearrange to quinazolinecarboxaldehyde. Mixed crystals of the two benzodiazepines, after recrystallization from benzene, lead to molecular alloys with complete solid solubility between oxazepam and the α-form of lorazepam over the whole range of composition but only to partial solubility with the β-form of lorazepam.

  12. Y{sub 2}O{sub 3}:Eu{sup 3+} (5 mol%) with Ag nanoparticles prepared by citrate precursor

    SciTech Connect

    Ferrari, J.L.; Cebim, M.A.; Pires, A.M.; Couto dos Santos, M.A.

    2010-09-15

    Y{sub 2}O{sub 3}:Eu{sup 3+} (5 mol% Eu{sup 3+}) and Y{sub 2}O{sub 3}:Eu{sup 3+} (5 mol% Eu{sup 3+}) containing 1 mol% of Ag nanoparticles were prepared by heat treatment of a viscous resin obtained via citrate precursor. TEM and EDS analyses showed that Y{sub 2}O{sub 3}:Eu{sup 3+} (5 mol% Eu{sup 3+}) is formed by nanoparticles with an average size of 12 nm, which increases to 30 nm when Ag is present because the effect of metal induced crystallization occurs. Ag nanoparticles with a size of 9 nm dispersed in Y{sub 2}O{sub 3}:Eu{sup 3+} (5 mol% Eu{sup 3+}) were obtained and the surface plasmon effect on Ag nanoparticles was observed. The emission around 612 nm assigned to the Eu{sup 3+} ({sup 5}D{sub 0{yields}}{sup 7}F{sub 2}) transition enhanced when the Ag nanoparticles were present in the Y{sub 2}O{sub 3}:Eu{sup 3+} luminescent material. - Graphical abstract: The presence of Ag nanoparticles together Y{sub 2}O{sub 3}:Eu{sup 3+} 5 mol% phosphor showed to affect directly the optical and crystallinity of the material. Luminescence spectra show directly the effect observed.

  13. Transferability of cucumber microsatellite markers used for phylogenetic analysis and population structure study in bottle gourd (Lagenaria siceraria (Mol.) Standl.).

    PubMed

    Bhawna; Abdin, M Z; Arya, L; Verma, M

    2015-02-01

    Improved breeding for developing fruit quality in bottle gourd (Lagenaria siceraria (Mol.) Standl.) necessitates knowledge regarding its genetic diversity. To achieve this, a set of 108 locus-specific SSR markers has been developed in bottle gourd by cross-species transferability from 995 mapped Cucumis sativus SSR markers. During screening, 280 primer pairs amplified in the bottle gourd germplasm, which were further evaluated in a diverse set of 42 lines, resulting in 19 polymorphic, 89 monomorphic, 15 with multiple bands, and the rest 157 showed no or very non-specific amplification. The 19 polymorphic primer pairs produced a total of 54 alleles. Gene diversity, Shannon's information index, and Nei's coefficient of differentiation were calculated suggesting a moderate genetic variation at the species level. A model-based population structure analysis divided these germplasm into two subpopulations. This marker set will be applicable for evaluating the genetic structure for association mapping, DNA fingerprinting, and mounting linkage maps and will be a practical tool set for further genetics. This study provides one of the first quantitative views of population genetic variation in bottle gourd. PMID:25471016

  14. Characterization of Transcriptome Remodeling during Cambium Formation Identifies MOL1 and RUL1 As Opposing Regulators of Secondary Growth

    PubMed Central

    Agusti, Javier; Lichtenberger, Raffael; Schwarz, Martina; Nehlin, Lilian; Greb, Thomas

    2011-01-01

    Cell-to-cell communication is crucial for the development of multicellular organisms, especially during the generation of new tissues and organs. Secondary growth—the lateral expansion of plant growth axes—is a highly dynamic process that depends on the activity of the cambium. The cambium is a stem cell–like tissue whose activity is responsible for wood production and, thus, for the establishment of extended shoot and root systems. Attempts to study cambium regulation at the molecular level have been hampered by the limitations of performing genetic analyses in trees and by the difficulty of accessing this tissue in model systems such as Arabidopsis thaliana. Here, we describe the roles of two receptor-like kinases, REDUCED IN LATERAL GROWTH1 (RUL1) and MORE LATERAL GROWTH1 (MOL1), as opposing regulators of cambium activity. Their identification was facilitated by a novel in vitro system in which cambium formation is induced in isolated Arabidopsis stem fragments. By combining this system with laser capture microdissection, we characterized transcriptome remodeling in a tissue- and stage-specific manner and identified series of genes induced during different phases of cambium formation. In summary, we provide a means for investigating cambium regulation in unprecedented depth and present two signaling components that control a process responsible for the accumulation of a large proportion of terrestrial biomass. PMID:21379334

  15. Mediterranean savanna of Acacia caven (Mol) is still a sink of CO2 in spite of severe hydrological drought conditions

    NASA Astrophysics Data System (ADS)

    Bravo-Martínez, F.; Meza, F. J.

    2012-12-01

    An eddy covariance tower was set up to monitor net ecosystem exchange (NEE) on a mediterranean shrubland of Acacia caven (Mol) in October 2010. This ecosystem (commonly referred as "espinal") is one of the most abundant land covers of Chile's central valley (2.000.000 ha). The last two years (2010-2011) were characterized by the occurrence of a severe drought (rainfall deficit 56%) and a small increase in temperature evaluated using a climatic change index (Peterson, 2005). We also detected a strong reduction in vegetation index during this period (evaluated using MODIS imagery). The historical analysis of the enhanced vegetation index (EVI) and leaf area index (LAI) showed that water status of the acacia savanna were at a minimum during this period (record of 14 years of data). The annual balance of NEE of 2011 was -54gC m-2 y-1, which means that the espinal is a sink of atmospheric CO2 notwithstanding the many stressors on photosynthesis. Monthly analysis of NEE shows the strong dependence of ecosystem fluxes on phenological state. Maximum rates of assimilation are a consequence of grassland activity, whereas secondary picks during the year (late spring and early autumn) are attributed to the semideciduos leaf of A. caven. Climatic conditions during the study season, confirm the tremendous plasticity of Acacia caven and its role as a colonizer of degraded sclerophyll forest because it adaptation to water and thermal stress.

  16. Catechin-based procyanidins from Peumus boldus Mol. aqueous extract inhibit Helicobacter pylori urease and adherence to adenocarcinoma gastric cells.

    PubMed

    Pastene, Edgar; Parada, Víctor; Avello, Marcia; Ruiz, Antonieta; García, Apolinaria

    2014-11-01

    In this work, the anti-Helicobacter pylori effect of an aqueous extract from dried leaves of Peumus boldus Mol. (Monimiaceae) was evaluated. This extract displayed high inhibitory activity against H. pylori urease. Therefore, in order to clarify the type of substances responsible for such effect, a bioassay-guided fractionation strategy was carried out. The active compounds in the fractions were characterized through different chromatographic methods (RP-HPLC; HILIC-HPLC). The fraction named F5 (mDP = 7.8) from aqueous extract was the most active against H. pylori urease with an IC50  = 15.9 µg gallic acid equivalents (GAE)/mL. HPLC analysis evidenced that F5 was composed mainly by catechin-derived proanthocyanidins (LC-MS and phloroglucinolysis). The anti-adherent effect of boldo was assessed by co-culture of H. pylori and AGS cells. Both the aqueous extract and F5 showed an anti-adherent effect in a concentration-dependent manner. An 89.3% of inhibition was reached at 2.0 mg GAE/mL of boldo extract. In conjunction, our results suggest that boldo extract has a potent anti-urease activity and anti-adherent effect against H. pylori, properties directly linked with the presence of catechin-derived proanthocyanidins. PMID:24853276

  17. Micro-solid oxide fuel cells using free-standing 3 mol.% yttria-stabilised-tetragonal-zirconia-polycrystal electrolyte foils

    NASA Astrophysics Data System (ADS)

    Evans, Anna; Bieberle-Hütter, Anja; Bonderer, Lorenz J.; Stuckenholz, Stefanie; Gauckler, Ludwig J.

    Ultrathin 3 mol.% yttria-stabilised-tetragonal-zirconia-polycrystal (Y-TZP) foils with thicknesses of 1-10 μm are fabricated by a new wet-chemical processing route. The foils are free-standing, semi-transparent and flexible. The in-plane electrical conductivity of the Y-TZP foil is 0.03 S m -1 at 500 °C. Cross-plane impedance measurements with sputtered Pt electrodes yield two arcs, of which the high-frequency arc is attributed to the ohmic resistance of the electrolyte and the low-frequency arc to the electrode-electrolyte interface. A symmetrical micro-solid oxide fuel cell (SOFC) is designed using this ultrathin free-standing Y-TZP foil as the electrolyte and sputtered Pt electrodes. An open-circuit voltage of 0.98 V and a maximum power density of 12 mW cm -2 are measured at 500 °C. These results prove the feasibility of this approach to the fabrication of miniaturised planar SOFCs without the need for microfabrication.

  18. Effect of heat treatment on deformation and mechanical properties of 8 mol% yttria-stabilized zirconia by Berkovich nanoindentation

    NASA Astrophysics Data System (ADS)

    Mao, W. G.; Luo, J. M.; Dai, C. Y.; Shen, Y. G.

    2015-05-01

    The effect of thermal treatment on the elasto-plastic transition and mechanical properties of air plasma-sprayed 8 mol% Y2O3-stabilized ZrO2 (8YSZ) thermal barrier coatings was studied by nanoindentation test at ultra-low loads with a Berkovich indenter. The area contact function of the indenter was calibrated repeatedly under nano-scales, and the indenter tip radius was estimated under different indentation depths, respectively. Owing to the heterogeneous and porous microstructure, the scatter of all collected experimental data was analyzed by Weibull statistic method. It is interesting to observe that the hardness exhibits an apparent reverse indentation size effect under very small depths. The Young's modulus of 8YSZ varies with ranging from 213 to 246 GPa due to the sintering effect. True hardness of 8YSZ increases from as-received 72.9 GPa to a top value 79.7 GPa under 100 thermal cycles, and then slightly decreases from this value to 75.5 GPa under 175 thermal cycles. The pure elastic and elasto-plastic indentation curves were obtained by adjusting the indentation load magnitude. The elasto-plastic transition and resolved shear stress fields were discussed carefully from the use of energetic models and Hertzian contact theory.

  19. MOL-D: A Collisional Database and Web Service within the Virtual Atomic and Molecular Data Center

    NASA Astrophysics Data System (ADS)

    Vujčič, V.; Jevremović, D.; Mihajlov, A. A.; Ignjatović, Lj. M.; Srećković, V. A.; Dimitrijević, M. S.; Malović, M.

    2015-12-01

    MOL-D database is a collection of cross-sections and rate coefficients for specific collisional processes and a web service within the Serbian Virtual Observatory (SerVO) and the Virtual Atomic and Molecular Data Center (VAMDC). This database contains photo-dissociation cross-sections for the individual ro-vibrational states of the diatomic molecular ions and rate coefficients for the atom-Rydberg atom chemi-ionization and inverse electron-ion-atom chemi-recombination processes. At the moment it contains data for photodissociation cross-sections of hydrogen H2+ and helium He2+ molecular ions and the corresponding averaged thermal photodissociation cross-sections. The ro-vibrational energy states and the corresponding dipole matrix elements are provided as well. Hydrogen and helium molecular ion data are important for calculation of solar and stellar atmosphere models and for radiative transport, as well as for kinetics of other astrophysical and laboratory plasma (i.e. early Universe).

  20. A 28,000 mol. wt toxin from Bacillus thuringiensis israelensis induces cation transport in rat muscle cultures.

    PubMed

    Cahan, R; Shainberg, A; Pechatnikov, I; Nitzan, Y

    1995-07-01

    The mechanism by which the Bacillus thuringiensis israelensis (Bti) 28,000 mol. wt toxin exerts its effect on mature muscle cultures was examined. The toxin inhibited Na+/K(+)-ATPase activity as revealed by 86Rb influx. A 50% inhibition of Na+/K(+)-ATPase activity was obtained with 0.2 microgram/ml of the toxin. The inhibition was time and dose dependent, and it was reversible with low doses of the toxin (up to 0.2 microgram/ml. A considerable release of 86Rb was obtained by doses greater than 0.2 microgram/ml. The 86Rb release was also time and dose dependent. This effect is probably non-specific, since 45Ca influx is also accelerated by toxin-treated cultures. Pre-incubation of the toxin with phosphotidylserine (PS) antagonized the toxin. It is concluded that the toxin is a hydrophobic protein which interacts with the membrane. In low doses this interaction reduces the activity of the sodium pump and in high doses it causes non-specific permeability of the sarcolemma. PMID:8588218

  1. Détermination assistée par ordinateur de la structure des molécules organiques

    NASA Astrophysics Data System (ADS)

    Nuzillard, J.-M.

    1998-02-01

    Nuclear Magnetic Resonance spectroscopy offers the unique possibility of accessing proximity relationships between atoms by means of chemical shift correlation experiments. Structure determination of small molecules has become thus much simpler. Computer programs can use directly correlation information for structure analysis. The use and operation mechanism of such a program, LSD (Logic for Structure Determination) are presented. The example compound is gibberellic acid, a natural product. La spectroscopie de Résonance Magnétique Nucléaire offre un moyen unique de déterminer des relations de proximité entre atomes par le biais des expériences de corrélation. L'analyse structurale de petites molécules organiques s'en trouve extrêmement facilitée. Des programmes informatiques peuvent utiliser directement les informations de corrélation pour déduire des structures. Le fonctionnement et l'usage d'un tel programme, LSD (Logic for Structure Determination), sont détaillés sur un exemple, l'acide gibberellique.

  2. Capteur de CO{2} à fibres optiques par absorption moléculaire à 4,3 μm

    NASA Astrophysics Data System (ADS)

    Bendamardji, S.; Alayli, Y.; Huard, S.

    1996-04-01

    This paper describes a remote optical fibre sensor for the carbon dioxide detection by molecular absorption in the near infrared (4.3 μm) corresponding to fundamental mode ν3. To overcome the problem of the strong attenuation signal of optical fibre in the near infrared, we have used the opto-suppling technique which changes the working wavelength from 4.3 μm to 860 nm and permits the use of standard optical fibre 50/125. The simulation of absorption has been obtained by original modelisation of the absorption spectrum and the establishment of the calibration curves takes to the sensor to detect a partial pressures greater than 100 μbar with a minimal error margin of 100 μbar, which is acceptable considering the future use of the device. The sensor has been designed to monitor the CO{2} rate in enriched greenhouses. Cet article décrit un capteur à fibres optiques de gaz carbonique par absorption moléculaire dans l'infrarouge moyen (4,3 μm) correspondant au mode fondamental ν3. La liaison entre le site de mesure et le site de contrôle est assurée par un fibre optique standard 50/125 après une transposition de longueur d'onde de 4,3 μm à 860 nm par opto-alimentation. La simulation de l'absorption a été obtenue par modélisation originale du spectre d'absorption et l'établissement des courbes d'étalonnage prévoit une marge d'erreur minimale de 100 μbar, ce qui est suffisant pour l'application du dispositif à la régulation de taux CO{2} dans les serres agricoles enrichies par de gaz.

  3. The role of 8 mol % yttria stabilized zirconia in the improvement of electrochemical performance of lanthanum manganite composite electrodes

    SciTech Connect

    Wang, S.; Jiang, Y.; Zhang, Y.; Yan, J.; Li, W.

    1998-06-01

    In this study, 8 mol % yttria stabilized zirconia (YSZ) + La{sub 0.8}Sr{sub 0.2}MnO{sub 3} (LSM) composite electrodes with addition of various amounts of YSZ were prepared on YSZ plates by a screen-printing method. The electrodes were then examined by scanning electron microscopy (SEM) and studied by ac impedance, cyclic voltammetry, and potential step as well as a polarization technique. For the oxygen reduction reaction on the pure LSM electrode, the dissociative adsorption of oxygen on the LSM surface and the transfer of oxygen ions from the triple-phase boundary (TPB) to the YSZ electrolyte lattice were found to be two comparable rate-determining steps. The electrochemical resistance of the former step was proportional to the {minus}0.5 power of p{sub O{sub 2}}, with a high activation energy of {approximately}2.0 eV. The electrochemical resistance of the latter step was found to be independent of p{sub O{sub 2}} with a low activation energy of {approximately}1.0 eV. With addition of YSZ to the LSM electrode, the electrochemical activity was improved substantially with much lower electrochemical resistances for both steps. Furthermore, the dissociative adsorption of oxygen became less rate determining on the electrode with more YSZ addition. It was found that the transfer of oxygen ion was the only rate-determining step on the 40% YSZ + LSM electrode. The improvement in the electrochemical performance with addition of YSZ was found mainly due to the spatial enlargement of the TPB area, which increased the electrochemically active sites for the oxygen adsorption and charge-transfer reaction.

  4. ExoMol: Large-scale production of line lists for molecules important for modelling of planetary atmospheres

    NASA Astrophysics Data System (ADS)

    Yurchenko, S.; Tennyson, J.

    2013-09-01

    The spectral characterization of astrophysical objects cool enough to form polyatomic molecules (the atmospheres of planets, brown dwarfs, planetary discs etc.) requires a huge amount of fundamental molecular data. With a few exceptions the existing molecular line lists are not sufficiently accurate and complete. The aim of ExoMol [1] is to generate comprehensive line lists for all molecules likely to be observable in exoplanet atmospheres in the foreseeable future (see www.exomol.com for more details). We identified the following 40 species that are important sources of opacity in (exo)planets and brown dwarfs and where there is currently a lack of fundamental data on wavelength and temperature-dependent absorption: • Diatomics: AlO, AlH, BeH, CaH, C2, CrH, FeH, HF, HCl, KCl, MgH, MgO, NaH, NaCl, NiH, O2,SiO, SiH, S2, SH, TiH, TiO, VO, YO • Triatomics: C3, H2S, SO2 • Tetratomics: H2CO, H2CS, HCCH, HOOH, PH3,SO3 • Pentatomics: CH4, HNO3 • Larger molecules: C2H4, C2H6, C3H8, P2H2, P2H4 The production of comprehensive and very large rotation-vibration and rotation-vibration-electronic line lists requires a mixture of first principles quantum mechanical methods and empirical tuning based on laboratory spectroscopic data and makes extensive use of state-of-the-art computing. These and other aspects of molecular line lists, their production and astrophysical applications will be discussed. The contribution will make specific reference to molecules for which line lists have recently been completed or are nearing completion: phosphine, hydrogen sulphide, hydrogen peroxide, methane, formaldehyde, nitric acid as well as to a number of diatomic molecules of astrophysical importance, see Fig. 1.

  5. MASSIVE STAR FORMATION, OUTFLOWS, AND ANOMALOUS H{sub 2} EMISSION IN Mol 121 (IRAS 20188+3928)

    SciTech Connect

    Wolf-Chase, Grace; Arvidsson, Kim; Smutko, Michael; Sherman, Reid

    2013-01-10

    We have discovered 12 new molecular hydrogen emission-line objects (MHOs) in the vicinity of the candidate massive young stellar object Mol 121, in addition to five that were previously known. H{sub 2} 2.12 {mu}m/H{sub 2} 2.25 {mu}m flux ratios indicate another region dominated by fluorescence from a photodissociation region, and one region that displays an anomalously low H{sub 2} 2.12 {mu}m/H{sub 2} 2.25 {mu}m flux ratio (<1) and coincides with a previously reported deeply embedded source (DES). Continuum observations at 3 mm reveal five dense cores; the brightest core is coincident with the DES. The next brightest cores are both associated with centimeter continuum emission. One of these is coincident with the IRAS source; the other lies at the centroid of a compact outflow defined by bipolar MHOs. The brighter of these bipolar MHOs exhibits [Fe II] emission and both MHOs are associated with CH{sub 3}OH maser emission observed at 95 GHz and 44 GHz. Masses and column densities of all five cores are consistent with theoretical predictions for massive star formation. Although it is impossible to associate all MHOs with driving sources in this region, it is evident that there are several outflows along different position angles, and some unambiguous associations can be made. We discuss implications of observed H{sub 2} 2.12 {mu}m/H{sub 2} 2.25 {mu}m and [Fe II] 1.64 {mu}m/H{sub 2} 2.12 {mu}m flux ratios and compare the estimated total H{sub 2} luminosity with the bolometric luminosity of the region. We conclude that the outflows are driven by massive young stellar objects embedded in cores that are likely to be in different evolutionary stages.

  6. Cantilever stress measurements for pulsed laser deposition of perovskite oxides at 1000 K in an oxygen partial pressure of 10(-4) millibars.

    PubMed

    Premper, J; Sander, D; Kirschner, J

    2015-03-01

    An in situ stress measurement setup using an optical 2-beam curvature technique is described which is compatible with the stringent growth conditions of pulsed laser deposition (PLD) of perovskite oxides, which involves high substrate temperatures of 1000 K and oxygen partial pressures of up to 1 × 10(-4) millibars. The stress measurements are complemented by medium energy electron diffraction (MEED), Auger electron spectroscopy, and additional growth rate monitoring by a quartz microbalance. A shielded filament is used to allow for simultaneous stress and MEED measurements at high substrate temperatures. A computer-controlled mirror scans an excimer laser beam over a stationary PLD target. This avoids mechanical noise originating from rotating PLD targets, and the setup does not suffer from limited lifetime issues of ultra high vacuum (UHV) rotary feedthroughs. PMID:25832240

  7. Space-resolved density diagnostic of a highly ionized holmium ([ital Z]=67) laser-produced plasma from 3[ital d][sup 10]4[ital l]-3[ital d][sup 10]4[ital l][prime] Cu I--like lines

    SciTech Connect

    Mandelbaum, P.; Behar, E. ); Seely, J.F.; Feldman, U.; Brown, C.M. ); Hammel, B.A.; Back, C.A.; Lee, R.W.; Kania, D.R. ); Bar-Shalom, A. )

    1994-06-01

    A space-resolved electron density diagnostic of a holmium laser-produced plasma has been performed using the intensity ratios of Cu I--like 3[ital d][sup 10]4[ital l]-3[ital d][sup 10]4[ital l][prime] lines. The atomic theoretical model of the Cu I--like ion included the 3[ital d][sup 10][ital nl] levels with [ital n]=4,5 and [ital l]=[ital s],[ital p],[ital d],[ital f]. The effect of line absorption at high electron densities is discussed and the atomic data obtained with the HULLAC computer code are compared with previously published data.

  8. EPR Spectroscopy of MolB2C2-A Reveals Mechanism of Transport for a Bacterial Type II Molybdate Importer*♦

    PubMed Central

    Rice, Austin J.; Alvarez, Frances J. D.; Schultz, Kathryn M.; Klug, Candice S.; Davidson, Amy L.; Pinkett, Heather W.

    2013-01-01

    In bacteria, ATP-binding cassette (ABC) transporters are vital for the uptake of nutrients and cofactors. Based on differences in structure and activity, ABC importers are divided into two types. Type I transporters have been well studied and employ a tightly regulated alternating access mechanism. Less is known about Type II importers, but much of what we do know has been observed in studies of the vitamin B12 importer BtuC2D2. MolB2C2 (formally known as HI1470/71) is also a Type II importer, but its substrate, molybdate, is ∼10-fold smaller than vitamin B12. To understand mechanistic differences among Type II importers, we focused our studies on MolBC, for which alternative conformations may be required to transport its relatively small substrate. To investigate the mechanism of MolBC, we employed disulfide cross-linking and EPR spectroscopy. From these studies, we found that nucleotide binding is coupled to a conformational shift at the periplasmic gate. Unlike the larger conformational changes in BtuCD-F, this shift in MolBC-A is akin to unlocking a swinging door: allowing just enough space for molybdate to slip into the cell. The lower cytoplasmic gate, identified in BtuCD-F as “gate I,” remains open throughout the MolBC-A mechanism, and cytoplasmic gate II closes in the presence of nucleotide. Combining our results, we propose a peristaltic mechanism for MolBC-A, which gives new insight in the transport of small substrates by a Type II importer. PMID:23709218

  9. RD-MolPack technology for the constitutive production of self-inactivating lentiviral vectors pseudotyped with the nontoxic RD114-TR envelope

    PubMed Central

    Marin, Virna; Stornaiuolo, Anna; Piovan, Claudia; Corna, Stefano; Bossi, Sergio; Pema, Monika; Giuliani, Erica; Scavullo, Cinzia; Zucchelli, Eleonora; Bordignon, Claudio; Rizzardi, Gian Paolo; Bovolenta, Chiara

    2016-01-01

    To date, gene therapy with transiently derived lentivectors has been very successful to cure rare infant genetic diseases. However, transient manufacturing is unfeasible to treat adult malignancies because large vector lots are required. By contrast, stable manufacturing is the best option for high-incidence diseases since it reduces the production cost, which is the major current limitation to scale up the transient methods. We have previously developed the proprietary RD2-MolPack technology for the stable production of second-generation lentivectors, based on the RD114-TR envelope. Of note, opposite to vesicular stomatitis virus glycoprotein (VSV-G) envelope, RD114-TR does not need inducible expression thanks to lack of toxicity. Here, we present the construction of RD2- and RD3-MolPack cells for the production of self-inactivating lentivectors expressing green fluorescent protein (GFP) as a proof-of-concept of the feasibility and safety of this technology before its later therapeutic exploitation. We report that human T lymphocytes transduced with self-inactivating lentivectors derived from RD3-MolPack cells or with self-inactivating VSV-G pseudotyped lentivectors derived from transient transfection show identical T-cell memory differentiation phenotype and comparable transduction efficiency in all T-cell subsets. RD-MolPack technology represents, therefore, a straightforward tool to simplify and standardize lentivector manufacturing to engineer T-cells for frontline immunotherapy applications. PMID:27222840

  10. RD-MolPack technology for the constitutive production of self-inactivating lentiviral vectors pseudotyped with the nontoxic RD114-TR envelope.

    PubMed

    Marin, Virna; Stornaiuolo, Anna; Piovan, Claudia; Corna, Stefano; Bossi, Sergio; Pema, Monika; Giuliani, Erica; Scavullo, Cinzia; Zucchelli, Eleonora; Bordignon, Claudio; Rizzardi, Gian Paolo; Bovolenta, Chiara

    2016-01-01

    To date, gene therapy with transiently derived lentivectors has been very successful to cure rare infant genetic diseases. However, transient manufacturing is unfeasible to treat adult malignancies because large vector lots are required. By contrast, stable manufacturing is the best option for high-incidence diseases since it reduces the production cost, which is the major current limitation to scale up the transient methods. We have previously developed the proprietary RD2-MolPack technology for the stable production of second-generation lentivectors, based on the RD114-TR envelope. Of note, opposite to vesicular stomatitis virus glycoprotein (VSV-G) envelope, RD114-TR does not need inducible expression thanks to lack of toxicity. Here, we present the construction of RD2- and RD3-MolPack cells for the production of self-inactivating lentivectors expressing green fluorescent protein (GFP) as a proof-of-concept of the feasibility and safety of this technology before its later therapeutic exploitation. We report that human T lymphocytes transduced with self-inactivating lentivectors derived from RD3-MolPack cells or with self-inactivating VSV-G pseudotyped lentivectors derived from transient transfection show identical T-cell memory differentiation phenotype and comparable transduction efficiency in all T-cell subsets. RD-MolPack technology represents, therefore, a straightforward tool to simplify and standardize lentivector manufacturing to engineer T-cells for frontline immunotherapy applications. PMID:27222840

  11. RD2-MolPack-Chim3, a Packaging Cell Line for Stable Production of Lentiviral Vectors for Anti-HIV Gene Therapy

    PubMed Central

    Stornaiuolo, Anna; Piovani, Bianca Maria; Bossi, Sergio; Zucchelli, Eleonora; Corna, Stefano; Salvatori, Francesca; Mavilio, Fulvio; Bordignon, Claudio; Rizzardi, Gian Paolo

    2013-01-01

    Abstract Over the last two decades, several attempts to generate packaging cells for lentiviral vectors (LV) have been made. Despite different technologies, no packaging clone is currently employed in clinical trials. We developed a new strategy for LV stable production based on the HEK-293T progenitor cells; the sequential insertion of the viral genes by integrating vectors; the constitutive expression of the viral components; and the RD114-TR envelope pseudotyping. We generated the intermediate clone PK-7 expressing constitutively gag/pol and rev genes and, by adding tat and rd114-tr genes, the stable packaging cell line RD2-MolPack, which can produce LV carrying any transfer vector (TV). Finally, we obtained the RD2-MolPack-Chim3 producer clone by transducing RD2-MolPack cells with the TV expressing the anti-HIV transgene Chim3. Remarkably, RD114-TR pseudovirions have much higher potency when produced by stable compared with transient technology. Most importantly, comparable transduction efficiency in hematopoietic stem cells (HSC) is obtained with 2-logs less physical particles respect to VSV-G pseudovirions produced by transient transfection. Altogether, RD2-MolPack technology should be considered a valid option for large-scale production of LV to be used in gene therapy protocols employing HSC, resulting in the possibility of downsizing the manufacturing scale by about 10-fold in respect to transient technology. PMID:23767932

  12. Characterizing exoplanet atmospheres with the 10.4m GTC telescope: New results from the world’s largest optical telescope

    NASA Astrophysics Data System (ADS)

    Wilson, Paul Anthony; Evans, Tom; Sing, David Kent; Nikolov, Nikolay; Lecavelier des Etangs, Alain; Colón, Knicole

    2015-12-01

    Exoplanet transit spectroscopy of hot Jupiters has given us the first detailed glimpses of the complex physical characteristics that govern these objects. These highly irradiated planets with their extended atmospheres lend themselves as excellent targets for probing their compositions, temperature-pressure profiles and the vertical abundance distributions.We have explored the atmospheres of several hot Jupiters using the 10.4m GTC telescope together with unique tunable filters capable of precision narrowband photometry at specific wavelengths. Using the worlds largest optical telescope we have been able to detect and characterise specific atmospheric features at higher resolutions than can be obtained with the Hubble Space Telescope. This is important as atmospheric signatures could be missed if the resolution is not sufficiently high.In this talk I will present a summary of the exoplanet atmospheres characterised with the GTC telescope. I will also present new results obtained by combining Kepler and GTC data to study the low-albedo atmosphere of TrES-2b.

  13. Influence of Fine Powder Feedstock (-10 + 2 μm) on the HVOF Spraying Characteristics, Coating Morphology, and Properties of WC-CoCr 86-10-4

    NASA Astrophysics Data System (ADS)

    Tillmann, W.; Nebel, J.; Piotrowski, W.

    2013-03-01

    The use of fine feedstock powder can extend the feasibility and scope of HVOF coatings to new fields of applications. Especially for the purpose of near-net-shape coatings, these powders facilitate homogeneous layer morphologies, and smooth coating surfaces. However, the small particle sizes also lead to several challenges. One major issue is the in-flight behavior which is distinctly affected by the low mass and relatively large specific surface of the particles. In this paper, the in-flight and coating characteristics of WC-CoCr 86-10-4 (-10 + 2 μm) were investigated. It was determined that the fine powder feedstock shows a high sensitivity to the gas flow, velocity, and temperature of the spray jet. Because of their low mass inertia, their velocity, for example, is actually influenced by local pressure nodes (shock diamonds) in the supersonic flow. Additionally, the relatively large specific surface of the particles promotes partial overheating and degradation. Nevertheless, the morphological and mechanical properties of the sprayed layer are hardly affected. In fact, the coatings feature a superior surface roughness, porosity, hardness, and wear resistance.

  14. Synthesis and characterisation of poly(acryalamide) grafted carboxymethyl xanthan gum copolymer.

    PubMed

    Badwaik, Hemant Ramchandra; Sakure, Kalyani; Alexander, Amit; Ajazuddin; Dhongade, Hemant; Tripathi, Dulal Krishna

    2016-04-01

    In the present work, an unreported graft copolymer of carboxymethyl xanthan gum and acrylamide has been synthesised by free radical polymerisation in a nitrogen atmosphere using ammonium persulphate as an initiator. The optimum reaction conditions adopted for affording maximum percentage of grafting including its grafting efficiency were obtained by varying the concentration of carboxymethyl xanthan gum from 4 to 24 g dm(-3); ammonium persulphate from 5×10(-4) to 30×10(-4)mol dm(-3); acrylamide from 0.4 to 1.2 mol dm(-3); reaction temperature from 55 to 75°C and reaction time from 30 to 90 min. The synthesised graft copolymer has been characterised by (1)H NMR, FTIR spectroscopy, X-ray diffraction measurement, thermal analysis, viscosity measurement and scanning electron microscopy. However, grafting of acrylamide onto carboxymethyl xanthan gum backbone enhanced its thermal stability. This graft copolymer might be well exploited globally as a potential carrier for drug delivery system. PMID:26772913

  15. The influence of hydrogen sulfide-to-hydrogen partial pressure ratio on the sulfidization of Pd and 70 mol% Pd–Cu membranes

    SciTech Connect

    Iyoha, O.; Enick, R.M.; Killmeyer, R.P.; Morreale, B.

    2007-11-15

    The influence of H2S-to-H2 partial pressure ratio on the sulfidization of Pd and 70 mol% Pd–Cu membrane alloys was studied using various H2Scontaining gas mixtures. The Pd membranes exposed to various H2S mixtures were in very good agreement with the thermodynamic calculations used in this study, resisting sulfidization when exposed to H2S-to-H2 ratios below the equilibrium value predicted for Pd4S formation, and experiencing sulfidization when exposed to ratios above the equilibrium values. The 70 mol% Pd–Cu membranes, however, exhibited deviations from the predicted values, resisting sulfidization at some conditions close to the equilibrium values at which sulfidization was expected, and experiencing sulfidization at some conditions at which resistance was expected. This phenomenon was attributed to deviations of the Pd–Cu alloy from ideality, probably due to Cu segregation at the membrane surface.

  16. The influence of hydrogen sulfide-to-hydrogen partial pressure ratio on the sulfidization of Pd and 70 mol% Pd-Cu membranes

    SciTech Connect

    Iyoha, O.; Enick, R.M.; Killmeyer, R.P.; Morreale, B.D.

    2007-11-15

    The influence of H2S-to-H2 partial pressure ratio on the sulfidization of Pd and 70 mol% Pd–Cu membrane alloys was studied using various H2S-containing gas mixtures. The Pd membranes exposed to various H2S mixtures were in very good agreement with the thermodynamic calculations used in this study, resisting sulfidization when exposed to H2S-to-H2 ratios below the equilibrium value predicted for Pd4S formation, and experiencing sulfidization when exposed to ratios above the equilibrium values. The 70 mol% Pd–Cu membranes, however, exhibited deviations from the predicted values, resisting sulfidization at some conditions close to the equilibrium values at which sulfidization was expected, and experiencing sulfidization at some conditions at which resistance was expected. This phenomenon was attributed to deviations of the Pd–Cu alloy from ideality, probably due to Cu segregation at the membrane surface.

  17. Structural homogeneity of photorefractive LiNbO3 crystals doped with 0.03-4.5 mol % of ZnO

    NASA Astrophysics Data System (ADS)

    Sidorov, N. V.; Palatnikov, M. N.; Teplyakova, N. A.; Gabain, A. A.; Efremov, I. N.

    2016-04-01

    Using the electronic spectroscopy method, the laser-conoscopy method, and the Raman light-scattering method, we have studied the structural homogeneity of LiNbO3 crystals doped with 0.03-4.5 mol % of ZnO. We have found that, as the laser radiation power is increased to 90 mW, the conoscopic patterns of crystals show additional distortions, which are attributed to the manifestation of the photorefractive effect. For the LiNbO3 crystal doped with 4.5 mol % of ZnO, in which the photorefractive effect is low, we have revealed a considerable shift (compared to the remaining crystals) of the optical absorption edge toward the shortwavelength range, which indicates a high structural homogeneity of this crystal. We have shown that, in the LiNbO3 crystal doped by 0.05 mol % ZnO, due to the displacement of NbLi and Li□ structural defects by Zn2+ cations, the crystal structure is ordered and, simultaneously, the number of defects with localized electrons decreases.

  18. Managing and delivering of 3D geo data across institutions has a web based solution - intermediate results of the project GeoMol.

    NASA Astrophysics Data System (ADS)

    Gietzel, Jan; Schaeben, Helmut; Gabriel, Paul

    2014-05-01

    The increasing relevance of geological information for policy and economy at transnational level has recently been recognized by the European Commission, who has called for harmonized information related to reserves and resources in the EU Member States. GeoMol's transnational approach responds to that, providing consistent and seamless 3D geological information of the Alpine Foreland Basins based on harmonized data and agreed methodologies. However, until recently no adequate tool existed to ensure full interoperability among the involved GSOs and to distribute the multi-dimensional information of a transnational project facing diverse data policy, data base systems and software solutions. In recent years (open) standards describing 2D spatial data have been developed and implemented in different software systems including production environments for 2D spatial data (like regular 2D-GI-Systems). Easy yet secured access to the data is of upmost importance and thus priority for any spatial data infrastructure. To overcome limitations conditioned by highly sophisticated and platform dependent geo modeling software packages functionalities of a web portals can be utilized. Thus, combining a web portal with a "check-in-check-out" system allows distributed organized editing of data and models but requires standards for the exchange of 3D geological information to ensure interoperability. Another major concern is the management of large models and the ability of 3D tiling into spatially restricted models with refined resolution, especially when creating countrywide models . Using GST ("Geosciences in Space and Time") developed initially at TU Bergakademie Freiberg and continuously extended by the company GiGa infosystems, incorporating these key issues and based on an object-relational data model, it is possible to check out parts or whole models for edits and check in again after modification. GST is the core of GeoMol's web-based collaborative environment designed to

  19. Development of 11-Plex MOL-PCR Assay for the Rapid Screening of Samples for Shiga Toxin-Producing Escherichia coli

    PubMed Central

    Woods, Travis A.; Mendez, Heather M.; Ortega, Sandy; Shi, Xiaorong; Marx, David; Bai, Jianfa; Moxley, Rodney A.; Nagaraja, T. G.; Graves, Steven W.; Deshpande, Alina

    2016-01-01

    Strains of Shiga toxin-producing Escherichia coli (STEC) are a serious threat to the health, with approximately half of the STEC related food-borne illnesses attributable to contaminated beef. We developed an assay that was able to screen samples for several important STEC associated serogroups (O26, O45, O103, O104, O111, O121, O145, O157) and three major virulence factors (eae, stx1, stx2) in a rapid and multiplexed format using the Multiplex oligonucleotide ligation-PCR (MOL-PCR) assay chemistry. This assay detected unique STEC DNA signatures and is meant to be used on samples from various sources related to beef production, providing a multiplex and high-throughput complement to the multiplex PCR assays currently in use. Multiplex oligonucleotide ligation-PCR (MOL-PCR) is a nucleic acid-based assay chemistry that relies on flow cytometry/image cytometry and multiplex microsphere arrays for the detection of nucleic acid-based signatures present in target agents. The STEC MOL-PCR assay provided greater than 90% analytical specificity across all sequence markers designed when tested against panels of DNA samples that represent different STEC serogroups and toxin gene profiles. This paper describes the development of the 11-plex assay and the results of its validation. This highly multiplexed, but more importantly dynamic and adaptable screening assay allows inclusion of additional signatures as they are identified in relation to public health. As the impact of STEC associated illness on public health is explored additional information on classification will be needed on single samples; thus, this assay can serve as the backbone for a complex screening system.

  20. Fabrication of short-period poled structures and UV sum-frequency generation in 8 mol % MgO-doped congruent LiTaO3 crystal

    NASA Astrophysics Data System (ADS)

    Oka, Toshiharu; Suhara, Toshiaki

    2016-04-01

    Heavily (8 mol %) MgO-doped congruent LiTaO3 (MgO:cLT) crystal has wider transparency range and is expected to have higher photorefractive damage resistance than LiNbO3 or non-doped LT crystal. We obtained uniform PP structures with periods of ∼7 and ∼2 µm in MgO:cLT crystal and demonstrated UV sum-frequency generation (SFG) experiments at 355 nm wavelength for the first time. The FWHM temperature acceptance bandwidths and the normalized SFG efficiencies were close to the calculated values.

  1. Deformation of as-cast LiF-22 mol pct CaF2 hypereutectic salt between 500 and 1015 K

    NASA Technical Reports Server (NTRS)

    Raj, S. V.; Whittenberger, J. D.

    1990-01-01

    Results are presented on compression tests conducted on as-cast LiF-22 mol pct CaF2 hypereutectic specimens at nominal strain rates between 1.8 x 10 to the -6th/sec and 0.25/sec over the temperature range 500-1015 K. In all instances, the stress-strain curves showed broad maxima, with negative strain-hardening rates after the peak stress sigma(max). It was found that, at low temperatures and high stresses, the CaF2 lamellae are rigid while the LiF matrix exhibits extensive transgranular cavitation, while at high temperatures and low stresses the CaF2 lamellae break down and spheroidize while the LiF matrix does not cavitate. It was concluded that the mechanical properties of the as-cast hypereutectic LiF-22 mol pct CaF2 are governed by the rate of deformation of the CaF2 phase. It is suggested that, for thermal energy storage applications, a spheroidal microstructure is more desirable than a lamellar structure.

  2. The adenovirus E3 10.4K and 14.5K proteins, which function to prevent cytolysis by tumor necrosis factor and to down-regulate the epidermal growth factor receptor, are localized in the plasma membrane.

    PubMed Central

    Stewart, A R; Tollefson, A E; Krajcsi, P; Yei, S P; Wold, W S

    1995-01-01

    The adenovirus type 2 and 5 E3 10,400- and 14,500-molecular-weight (10.4K and 14.5K) proteins are both required to protect some cell lines from lysis by tumor necrosis factor and to down-regulate the epidermal growth factor receptor. We have shown previously that both 10.4K and 14.5K are integral membrane proteins and that 14.5K is phosphorylated and O glycosylated. The 10.4K protein coimmunoprecipitates with 14.5K, indicating that the two proteins function as a complex. Here we show, using immunofluorescence and two different cell surface-labeling techniques, that both proteins are localized in the plasma membrane. In addition, we show that trafficking of each protein to the plasma membrane depends on concomitant expression of the other protein. Finally, neither protein could be immunoprecipitated from conditioned media, indicating that neither is secreted. Taken together, these results suggest that the plasma membrane is the site at which 10.4K and 14.5K function to inhibit cytolysis by tumor necrosis factor and to down-regulate the epidermal growth factor receptor. PMID:7983708

  3. Transfer Partial Molar Isentropic Compressibilities of ( l-Alanine/ l-Glutamine/Glycylglycine) from Water to 0.512 {mol} \\cdot {kg}^{-1} Aqueous {KNO}3/0.512 {mol} \\cdot {kg}^{-1} Aqueous {K}2{SO}4 Solutions Between 298.15 K and 323.15 K

    NASA Astrophysics Data System (ADS)

    Riyazuddeen; Gazal, Umaima

    2013-03-01

    Speeds of sound of ( l-alanine/ l-glutamine/glycylglycine + 0.512 {mol}\\cdot {kg}^{-1} aqueous {KNO}3/0.512 {mol}\\cdot {kg}^{-1} aqueous {K}2{SO}4) systems have been measured for several molal concentrations of amino acid/peptide at different temperatures: T = (298.15 to 323.15) K. Using the speed-of-sound and density data, the parameters, partial molar isentropic compressibilities φ _{kappa }0 and transfer partial molar isentropic compressibilities Δ _{tr} φ _{kappa }0, have been computed. The trends of variation of φ _{kappa }0 and Δ _{tr} φ _{kappa }0 with changes in molal concentration of the solute and temperature have been discussed in terms of zwitterion-ion, zwitterion-water dipole, ion-water dipole, and ion-ion interactions operative in the systems.

  4. Contrôle de l'orientation et de l'alignement moléculaire par un train d'impulsions soudaines

    NASA Astrophysics Data System (ADS)

    Sugny, D.

    2006-10-01

    Les récents progrès technologiques dans le domaine des Lasers permettent d'envisager le contrôle de nombreux processus quantiques jouant un rôle dans une variété de problèmes s'étendant de la réactivité chimique à l'information quantique. Dans ce contexte, nous nous sommes intéressés au contrôle de l'orientation ou de l'alignement moléculaire en utilisant un train d'impulsions soudaines. Nous avons défini des états cibles qui maximisent à la fois l'orientation ou l'alignement et sa durée dans le temps et montré comment atteindre ces états à l'aide de stratégie systématique ou optimisée

  5. Effect of Feedstock Powders on the Microstructural and Electrical Characteristics of 8 mol% Yttria-Stabilized Zirconia Plasma-Sprayed Coatings

    NASA Astrophysics Data System (ADS)

    Prakash, B. Shri; Balaji, N.; Grips, V. K. William; Siju; Aruna, S. T.

    2012-12-01

    Plasma-sprayed coatings of 8 mol% yttria-stabilized zirconia (YSZ) were fabricated using the feedstock powders obtained from co-precipitation (PPT) and spray-drying (SD) processes. Particle size and the specific mass (SM) of the feedstock powder were found to be the critical parameters that influence the microstructural and electrical properties of the coatings. While dense and larger particle-sized PPT powder resulted in a porous microstructure, dense coatings were obtained for SD powders with relatively lower SM. Electrical conductivity values of SD-coatings were found to be 30% higher than that of PPT-coatings. Electrical conductivity values of plasma-sprayed PPT-coatings improved significantly on decreasing the particles size. However, the size effect was only subtle in the case of SD coatings. PPT-coatings fabricated from smaller particle-sized powders had the necessary electrical conductivities appropriate for solid oxide fuel cell electrolyte applications.

  6. Determination of inorganic ionic mercury down to 5x10(-14) mol l(-1) by differential-pulse anodic stripping voltammetry.

    PubMed

    Meyer, S; Scholz, F; Trittler, R

    1996-09-01

    A new method is described for the reliable and ultrasensitive determination of inorganic ionic mercury, using differential-pulse anodic stripping voltammetry on a glassy carbon electrode. It has been possible to determine mercury down to a concentration of 5x10(-14) mol l(-1) (the lowest detection limit ever reported for a voltammetric method). This success was achieved by using a thiocyanate electrolyte and relatively long deposition times. The mercury ions are stabilized in the solution by the formation of strong thiocyanate complexes. This leads to a highly reproducible cathodic plating and anodic dissolution of mercury. A speciation analysis allowing to distinguish between dissolved atomic and ionic mercury in water is possible. PMID:15048362

  7. Structure and optical homogeneity of LiNbO{sub 3}:Zn (0.03–4.5 mol.%) crystals

    SciTech Connect

    Sidorov, Nikolay E-mail: tepl-na@chemy.kolasc.net.ru E-mail: Jovial1985@yandex.ru Tepljakova, Natalja E-mail: tepl-na@chemy.kolasc.net.ru E-mail: Jovial1985@yandex.ru Gabain, Aleksei E-mail: tepl-na@chemy.kolasc.net.ru E-mail: Jovial1985@yandex.ru Yanichev, Aleksander E-mail: tepl-na@chemy.kolasc.net.ru E-mail: Jovial1985@yandex.ru Palatnikov, Mikhail E-mail: tepl-na@chemy.kolasc.net.ru E-mail: Jovial1985@yandex.ru

    2014-11-14

    Structure and optical homogeneity of LiNbO{sub 3}:Zn (0.03–4.5 mol.%) crystals were searched by photoinduced light scattering and by Raman spectroscopy. The photorefractive effect depends on Zn{sup 2+} concentration nonmonotonically. Decrease of photorefractive effect is explained by decrease of structure defects with localized electrons. The Zn{sup 2+} cations replace structure defects Nb{sub Li} and Li{sub Nb}, trapping levels appear near the bottom of the conduction band and photo electrons recombine with emission under laser radiation. By the Raman spectra the area of the high structure order is found. In this area the own alternation, the alternation of impurity cations and the vacancies along the polar axis is almost perfect.

  8. Crystal structure of (2R)-1-[(methyl­sulfon­yl)­oxy]propan-2-aminium chloride: a chiral mol­ecular salt

    PubMed Central

    Rajegowda, H. R.; Palakshamurthy, B. S.; Lokanath, N. K.; Naveen, S.; Raghavendra Kumar, P.

    2015-01-01

    In the title chiral mol­ecular salt, C4H12NO3S+·Cl−, the cation is protonated at the N atom, producing [RNH3]+, where R is CH3SO2OCH2C(H)CH3. The N atom in the cation is sp 3-hybridized. In the crystal, cations and anions are connected by strong N—H⋯Cl hydrogen bonds to generate edge-shared 12-membered rings of the form {⋯Cl⋯HNH}3. This pattern of hydrogen bonding gives rise to zigzag supra­molecular layers in the ab plane. The layers are connected into a three-dimensional architecture by C—H⋯O hydrogen bonds. The structure was refined as an inversion twin. PMID:26594448

  9. Permeation of mixtures of four phenols through a supported liquid membrane in NaCl 1.0 mol/dm{sup 3} medium

    SciTech Connect

    Arana, G.; Borge, G.; Etxebarria, N.; Fernandez, L.A.

    1999-02-01

    The permeation of four phenols (phenol, 2-chlorophenol, 2-nitrophenol, and 2,4-dichlorophenol) through a supported liquid membrane has been studied in NaCl 1.0 mol/dm{sup 3} medium. The flux of each phenol was determined by measuring in real time the change of their concentration in the strip phase by making use of a fiber optic spectrophotometer and a multivariate calibration. The model for the permeation of phenol alone was first developed by making permeation experiments of a phenol, and then permeation studies of the mixture were carried out and the model was extended to those phenols. It was found that the permeation of a phenol is interfered with by the presence of other phenols.

  10. XPS and ToF-SIMS analysis of natural rubies and sapphires heat-treated in a reducing (5 mol% H 2/Ar) atmosphere

    NASA Astrophysics Data System (ADS)

    Achiwawanich, S.; James, B. D.; Liesegang, J.

    2008-12-01

    Surface effects on Mong Hsu rubies and Kanchanaburi sapphires after heat treatment in a controlled reducing atmosphere (5 mol% H 2/Ar) have been investigated using advanced surface science techniques including X-ray photoelectron spectroscopy (XPS) and time-of-flight secondary ion mass spectrometry (ToF-SIMS). Visual appearance of the gemstones is clearly affected by the heat treatment in a reducing atmosphere. Kanchanaburi sapphires, in particular, exhibit Fe-containing precipitates after the heat treatment which have not been observed in previous studies under an inert atmosphere. Significant correlation between changes in visual appearance of the gemstones and variations in surface concentration of trace elements, especially Ti and Fe are observed. The XPS and ToF-SIMS results suggest that; (1) a reducing atmosphere affects the oxidation state of Fe; (2) dissociation of Fe-Ti interaction may occur during heat treatment.

  11. Study of Li 2TiO 3 + 5 mol% TiO 2 lithium ceramics after long-term neutron irradiation

    NASA Astrophysics Data System (ADS)

    Chikhray, Y.; Shestakov, V.; Maksimkin, O.; Turubarova, L.; Osipov, I.; Kulsartov, T.; Kuykabayeba, A.; Tazhibayeva, I.; Kawamura, H.; Tsuchiya, K.

    2009-04-01

    Given work presents the results of complex material-science studies of 1 mm diameter ceramic pebbles manufactured of Li 2TiO 3 + 5 mol% TiO 2 ceramics before and after long-time neutron irradiation. Ceramic samples were placed in specially ampoules (six items) made of stainless steel Cr18Ni10Ti which were vacuumized and filled with helium. Irradiation of ampoules was carried out in the loop channel of WWRK reactor (Almaty, Kazakhstan) during 223 days at 6 MW power. After irradiation light-colored pebbles became grey-colored due to structure changes which generation of grey-colored inclusions (lithium oxide) with low density and microhardness. There is a radiation softening of lithium ceramic and that effect is higher for lower irradiation temperature 760 K than for 920 K. The value of maximum permissible load (pebble crash limit) at that is low and comprises ˜37.9 N. The content of residual tritium is higher for ceramic irradiated at 760 K (6.6 ± 0.6 × 10 11 Bq/kg) than for ceramic irradiated at 920 K (17 ± 3 × 10 10 Bq/kg). The size change indicates that pebble increase more after irradiation at 760 K than at 920 K where the bigger portion of tritium leaves the pebble. X-ray analysis shows radiation modification of Li 2TiO 3 + 5 mol% TiO 2 phase composition and generation of new phases: LiTi 2O 4, LiTiO 2 and Li 4Ti 5O 12.

  12. BioMOL: a computer-assisted biological modeling tool for complex chemical mixtures and biological processes at the molecular level.

    PubMed Central

    Klein, Michael T; Hou, Gang; Quann, Richard J; Wei, Wei; Liao, Kai H; Yang, Raymond S H; Campain, Julie A; Mazurek, Monica A; Broadbelt, Linda J

    2002-01-01

    A chemical engineering approach for the rigorous construction, solution, and optimization of detailed kinetic models for biological processes is described. This modeling capability addresses the required technical components of detailed kinetic modeling, namely, the modeling of reactant structure and composition, the building of the reaction network, the organization of model parameters, the solution of the kinetic model, and the optimization of the model. Even though this modeling approach has enjoyed successful application in the petroleum industry, its application to biomedical research has just begun. We propose to expand the horizons on classic pharmacokinetics and physiologically based pharmacokinetics (PBPK), where human or animal bodies were often described by a few compartments, by integrating PBPK with reaction network modeling described in this article. If one draws a parallel between an oil refinery, where the application of this modeling approach has been very successful, and a human body, the individual processing units in the oil refinery may be considered equivalent to the vital organs of the human body. Even though the cell or organ may be much more complicated, the complex biochemical reaction networks in each organ may be similarly modeled and linked in much the same way as the modeling of the entire oil refinery through linkage of the individual processing units. The integrated chemical engineering software package described in this article, BioMOL, denotes the biological application of molecular-oriented lumping. BioMOL can build a detailed model in 1-1,000 CPU sec using standard desktop hardware. The models solve and optimize using standard and widely available hardware and software and can be presented in the context of a user-friendly interface. We believe this is an engineering tool with great promise in its application to complex biological reaction networks. PMID:12634134

  13. Comparison of the Predicted Population Coverage of Tuberculosis Vaccine Candidates Ag85B-ESAT-6, Ag85B-TB10.4, and Mtb72f via a Bioinformatics Approach

    PubMed Central

    Davila, Jose; McNamara, Lucy A.; Yang, Zhenhua

    2012-01-01

    The Bacille-Calmette Guérin (BCG) vaccine does not provide consistent protection against adult pulmonary tuberculosis (TB) worldwide. As novel TB vaccine candidates advance in studies and clinical trials, it will be critically important to evaluate their global coverage by assessing the impact of host and pathogen variability on vaccine efficacy. In this study, we focus on the impact that host genetic variability may have on the protective effect of TB vaccine candidates Ag85B-ESAT-6, Ag85B-TB10.4, and Mtb72f. We use open-source epitope binding prediction programs to evaluate the binding of vaccine epitopes to Class I HLA (A, B, and C) and Class II HLA (DRB1) alleles. Our findings suggest that Mtb72f may be less consistently protective than either Ag85B-ESAT-6 or Ag85B-TB10.4 in populations with a high TB burden, while Ag85B-TB10.4 may provide the most consistent protection. The findings of this study highlight the utility of bioinformatics as a tool for evaluating vaccine candidates before the costly stages of clinical trials and informing the development of new vaccines with the broadest possible population coverage. PMID:22815851

  14. Grupos españoles de cálculos ab initio de moléculas de interés astrofísico

    NASA Astrophysics Data System (ADS)

    Yáñez, M.

    Pocos campos de la química están tan bien adaptados a la modelización por medio de los métodos teóricos de la Química Cuántica como la Astroquímica y la Química de la Atmósfera, donde las interacciones moleculares son, generalmente, lo suficientemente pequeñas para que el modelo de molécula aislada funcione muy bien. En España son varios los grupos teóricos que dedican su esfuerzo de investigación, o parte de él, al estudio de moléculas o procesos de interés en Astrofísica o en atmósferas planetarias. Presentaremos diferentes ejemplos paradigmáticos de esta actividad en la que se exploran desde aspectos estructurales, hasta aspectos espectroscópicos y dinámicos. Entre los últimos, cabe destacar estudios en los que se demuestra la importancia de procesos a dos estados, prohibidos por espín, en la formación astrofísica de diversos derivados de interés. En el tratamiento espectroscópico se han hecho esfuerzos interesantes, que han aunado teoría y experimento, en el estudio de sistemas relevantes desde el punto de vista atmosférico, como los hidratos de ácido nítrico, o el tratamiento espectroscópico de moléculas no rígidas. No menos interesantes son los estudios de fotoabsorción de radicales o de procesos multifotónicos. Son particularmente abundantes los estudios dedicados a la reactividad específica de sistemas de interés astrofísico o atmosférico, con el objetivo de esclarecer vías de formación de determinados compuestos o de proporcionar mecanismos que permitan identificar las etapas reactivas limitantes de reacciones de interés en esos medios y sobre los que no existía información previa. Así, por ejemplo, se han publicado interesantes estudios sobre la formación o propiedades de compuestos de fósforo, de silico o de azufre o sobre mecanismos de reacción en los que intervienen el ozono, el radical nitrato, el radical OH u otras especies. Finalmente, son también particularmente relevantes los estudios que varios

  15. Crystal and mol­ecular structure of meso-2,6-di­bromo­hepta­nedioic acid (meso-2,6-di­bromo­pimelic acid)

    PubMed Central

    Dirda, Nathaniel D. A.; Zavalij, Peter Y.; Kao, Joseph P. Y.

    2016-01-01

    The mol­ecular structure of the title compound, C7H10Br2O4, confirms the meso (2R,6S) configuration. In the crystal, mol­ecules are linked by pairs of O—H⋯O=C hydrogen bonds between their terminal carboxyl groups in an R 2 2(8) motif, forming extended chains that propagate parallel to the c axis. Adjacent chains are linked by C=O⋯Br halogen bonds. PMID:27006797

  16. 43 CFR 10.4 - Inadvertent discoveries.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... National Historical Preservation Act (16 U.S.C. 470 (f) et seq.), 36 CFR 800.11 or section 3 (a) of the... Preservation Act (16 U.S.C. 470 (f) et seq.), 36 CFR 800.11 or section 3 (a) of the Archeological and Historic... REPATRIATION REGULATIONS Human Remains, Funerary Objects, Sacred Objects, or Objects of Cultural Patrimony...

  17. 44 CFR 10.4 - Policy.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... environment without degradation, or undesirable and unintended consequences; (2) Preserving historic, cultural... development within the sustained carrying capacity of the ecosystem involved; and (4) Enhancing the quality...

  18. 43 CFR 10.4 - Inadvertent discoveries.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Public Lands: Interior Office of the Secretary of the Interior NATIVE AMERICAN GRAVES PROTECTION AND...) Notify any known lineal descendants of a deceased Native American individual whose human remains and... responsibilities under section 106 of the National Historical Preservation Act (16 U.S.C. 470 (f) et seq.), 36...

  19. 43 CFR 10.4 - Inadvertent discoveries.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... responsibilities under section 106 of the National Historical Preservation Act (16 U.S.C. 470 (f) et seq.), 36 CFR 800.11 or section 3 (a) of the Archeological and Historic Preservation Act (16 U.S.C. 469 (a-c... section 106 of the National Historical Preservation Act (16 U.S.C. 470 (f) et seq.), 36 CFR 800.11...

  20. 43 CFR 10.4 - Inadvertent discoveries.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... National Historical Preservation Act (16 U.S.C. 470 (f) et seq.), 36 CFR 800.11 or section 3 (a) of the... Preservation Act (16 U.S.C. 470 (f) et seq.), 36 CFR 800.11 or section 3 (a) of the Archeological and...

  1. Direct identification of phenolic constituents in Boldo Folium (Peumus boldus Mol.) infusions by high-performance liquid chromatography with diode array detection and electrospray ionization tandem mass spectrometry.

    PubMed

    Simirgiotis, M J; Schmeda-Hirschmann, G

    2010-01-22

    A very simple and direct method was developed for the qualitative analysis of polyphenols in boldo (Peumus boldus Mol., Monimiaceae) leaves infusions by high-performance liquid chromatography with diode array detection (HPLC-DAD) and electrospray ionization tandem mass spectrometry (HPLC-MS(n)). The phenolic constituents identified in infusions of the crude drug Boldo Folium were mainly proanthocyanidins and flavonol glycosides. In the infusions, 41 compounds were detected in male and 43 compounds in female leaf samples, respectively. Nine quercetin glycosides, eight kaempferol derivatives, nine isorhamnetin glycosides, three phenolic acids, one caffeoylquinic acid glycoside and twenty one proanthocyanidins were identified by HPLC-DAD and ESI-MS for the first time in the crude drug. Isorhamnetin glucosyl-di-rhamnoside was the most abundant flavonol glycoside in the male boldo sample, whereas isorhamnetin di-glucosyl-di-rhamnoside was the main phenolic compound in female boldo leaves infusion. The results suggest that the medicinal properties reported for this popular infusion should be attributed not only to the presence of catechin and boldine but also to several phenolic compounds with known antioxidant activity. The HPLC fingerprint obtained can be useful in the authentication of the crude drug Boldo Folium as well as for qualitative analysis and differentiation of plant populations in the tree distribution range. PMID:20022332

  2. Biréfringence électrique et polarisabilités moléculaires de CF2Cl-CCl3

    NASA Astrophysics Data System (ADS)

    Benoit-Denis, Anne-Marie

    Nous nous proposons de déterminer les valeurs des polarisabilités moléculaires relatives aux trois radiations principales de l'arc au mercure, ainsi que la direction des axes de l'ellipsoïde de polarisabilité optique de CF2Cl-CCl3, à partir des résultats de mesures d'effet Kerr de ce composé à l'état liquide. La biréfringence électrique de CF2Cl-CCl3 change de signe à la température T0=295 K. Ainsi nous obtenons une relation supplémentaire très utile entre les valeurs principales du tenseur de polarisabilité. Nous utilisons pour l'expression de la constante de Kerr la formule de Langevin-Born et faisons appel à la théorie des polarisabilités de liaisons pour calculer la valeur de la polarisabilité principale normale au plan de symétrie de CF2Cl-CCl3.

  3. Elasto-plastic characteristics and mechanical properties of as-sprayed 8 mol% yttria-stabilized zirconia coating under nano-scales measured by nanoindentation

    NASA Astrophysics Data System (ADS)

    Luo, J. M.; Dai, C. Y.; Shen, Y. G.; Mao, W. G.

    2014-08-01

    The elasto-plastic characteristics and mechanical properties of as-received 8 mol% Y2O3-ZrO2 (8YSZ) coatings were studied by nanoindentation at ultra-low loads with a Berkovich indenter at room temperature. All experimental data including hardness H and elastic modulus E were analyzed by the Weibull statistical method due to the porous and heterogeneous nature of the tested samples. It was found that the hardness firstly exhibits interesting reverse indentation size effect, and then shows normal indentation size effect within different indentation scales. The average elastic modulus of 8YSZ was estimated as 214.8 ± 13.2 GPa. In order to reveal the elasto-plastic characteristics of 8YSZ at nano-scales, the distribution of resolved shear stresses underneath the indenter tip region was evaluated by Hertzian contact theory when the deformation behavior of 8YSZ changed from fully elastic to elasto-plastic stages. The results shed light on understanding possible foreign object damage mechanisms of thermal barrier coating systems.

  4. Estudio teórico de moléculas de interés en Astrofísica: compuestos binarios policarbonados

    NASA Astrophysics Data System (ADS)

    Largo-Cabrerizo, A.

    Se han detectado en el espacio distintos compuestos binarios policarbonados (que se pueden formular como CnX), algunos de ellos con elementos de la primera fila del sistema periódico, pero también existen otros que contienen elementos de la segunda fila, como azufre o silicio. La información experimental sobre estos últimos compuestos es escasa, por lo que los estudios teóricos son especialmente valiosos en este campo. En esta comunicación presentaremos los avances mas recientes que sobre el tema ha realizado nuestro grupo. Incidiremos particularmente en dos aspectos. En primer lugar resumiremos los estudios en los que hemos intentado proporcionar información estructural sobre carburos metálicos formados por sodio, magnesio, aluminio o calcio, que pueda ser de ayuda a la hora de caracterizar estas moléculas en laboratorio como paso previo a su eventual detección en el espacio. Un aspecto importante dentro de este primer apartado es el análisis de las propiedades moleculares en función del tamaño del sistema (cuantificado en el numero de átomos de carbono) con el objeto de intentar sistematizar su estudio. En segundo lugar comentaremos brevemente algunos de los estudios realizados sobre posibles reacciones que pueden ser vías de síntesis de este tipo de compuestos en el medio interestelar.

  5. New insights about the presence of celestite into fossil bones from Molí del Baró 1 site (Isona i Conca Dellá, Lleida, Spain)

    NASA Astrophysics Data System (ADS)

    Piga, Giampaolo; Brunetti, Antonio; Lasio, Barbara; Malfatti, Luca; Galobart, Àngel; Dalla Vecchia, Fabio M.; Enzo, Stefano

    2015-02-01

    We have addressed an X-ray fluorescence (XRF) and X-ray diffraction (XRD) on a collection of thirteen fossil bone belonging to the Molí del Baró 1 paleontological site located near Sant Romà d'Abella (Isona i Conca Dellà Municipality, Lleida Province, Spain, dated to about 66.5 Ma, to investigate the fossilization occurred in this site in terms of physico-chemical properties. As a general behaviour, the XRD patterns showed the bioapatite mineral at a varying level of percentage, and accordingly, the correspondent XRF spectra turned out to be mainly dominated by the presence of Ca, obviously accompanied by phosphorus. Simultaneously, other elements such as Sr, Fe, Ba and Zn were found at non-negligible concentration levels and helped to assign the phase components in the XRD spectra. In three specimens, it was observed by XRD the rather unusual case where the original bioapatite bone mineral was completely substituted for by other mineralogical phases. In addition to this, celestite was also found as an important phase in ten specimens out of the thirteen examined. The occurrence of celestite in the bone structure appears a rather unusual observation within the literature of bones diagenesis. Its provenance is generally ascribed to marine vertebrate organisms, but the presence in the fossil bones of this site, where no evidence of marine environment exists, can be reconciled with occurrence of refluxing processes involving diagenetically altered fluids which were discharged into beds containing strontium sulphate-rich waters.

  6. Final report on key comparison CCQM-K73: Amount content of H+ in hydrochloric acid (0.1 mol kg-1)

    NASA Astrophysics Data System (ADS)

    Pratt, Kenneth W.; Ortiz-Aparicio, Jose Luis; Matehuala-Sanchez, Francisco Javier; Pawlina, Monika; Kozlowski, Wladyslaw; Borges, Paulo P.; da Silva Junior, Wiler B.; Borinsky, Mónica B.; Hernandez-Mabel Puelles, Ana; Hatamleh, Nadia; Acosta, Osvaldo; Nunes, João; Guiomar Lito, M. J.; Camões, M. Filomena; Filipe, Eduarda; Hwang, Euijin; Lim, Youngran; Bing, Wu; Qian, Wang; Chao, Wei; Hioki, Akiharu; Asakai, Toshiaki; Máriássy, Michal; Hanková, Zuzana; Nagibin, Sergey; Manska, Olexandra; Gavrilkin, Vladimir

    2013-01-01

    This key comparison (KC), CCQM-K73, was performed to demonstrate the capability of the participating National Metrology Institutes (NMIs) to measure the amount content of H+, νH+, in an HCl solution with a nominal νH+ of 0.1 mol kg-1. The comparison was a joint activity of the Electrochemical Working Group (EAWG) and Inorganic Analysis Working Group (IAWG) of the CCQM and was coordinated by NIST (USA) and CENAM (Mexico). The agreement of the results was not commensurate with the claimed uncertainties of the subset of participants that claimed small uncertainties for this determination. A workshop on technical issues relating to the CCQM-K73 measurements was conducted at the joint IAWG-EAWG meeting at the Bureau International des Poids et Mesures (BIPM), Paris (Sèvres) in April 2010. Several possible sources of bias were investigated, but none could explain the observed dispersion among the participants' results. In the absence of a specific cause for the dispersion, the IAWG and EAWG decided to assign a Key Comparison Reference Value, KCRV, and standard uncertainty of the KCRV, uKCRV, based on the DerSimonian-Laird statistical estimator. The uKCRV is dominated by the between-laboratory scatter of results in CCQM-K73. The uncertainty estimates from the participants with the lowest reported uncertainties remain unsupported by this KC. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

  7. Solvothermal syntheses and characterizations of three new holmium selenidostannates(iv): a rare example of adamantane-like [Sn4Se10](4-) selenidostannate(iv) with lanthanide complexes.

    PubMed

    Xiao, Hong-Ping; Zhou, Jian; Wang, Xiao-Li; Zou, Hua-Hong; Zhao, Rong-Qing; Xiao, Hong

    2014-08-28

    Three new holmium selenidostannates(iv), [Ho(dap)4]2[Sn2Se6]Cl2 (, dap = diaminopropane), {[Ho(dien)2]2(μ2-OH)2}[Sn2Se6] (, dien = diethylenetriamine), and [Ho2(tepa)2(μ2-OH)2Cl2]2[Sn4Se10]·4H2O (, tepa = tetraethylenepentamine), have been solvothermally synthesized and structurally characterized. consists of two mononuclear [Ho(dap)4](3+) complex cations, one [Sn2Se6](4-) anion built up from two [SnSe4] tetrahedra sharing a common edge, and two Cl(-) ions. consists of one binuclear holmium(iii) complex {[Ho(dien)2]2(μ2-OH)2}(4+) cation and one dimeric [Sn2Se6](4-) anion. is composed of rare binuclear holmium(iii) complex [Ho2(tepa)2(μ2-OH)2Cl2](2+) cations, adamantane-like [Sn4Se10](4-) and free water molecules. Although a few chalcogenidostannates(iv) with lanthanide(iii) complex cations acting as counterions have been reported, their anions are strongly dominated by the dimeric [Sn2Se6](4-) moieties. represents a rare example of an adamantane-like [Sn4Se10](4-) selenidostannate with lanthanide complexes as counterions. The optical properties of have been investigated by UV-vis spectroscopy. PMID:24986054

  8. Influence of 2mol% Na/Bi excess on multiferroic properties of (Na0.5Bi0.5) 0.99La0.01Ti0.988 Fe0.012O3 lead free system

    NASA Astrophysics Data System (ADS)

    Parmar, Kusum; Sharma, Hakikat; Kotnala, R. K.; Negi, N. S.

    2016-05-01

    Lead free (Na0.5Bi0.5) 0.99La0.01Ti0.988 Fe0.012O3 (NBLTF) system has been synthesized by sol gel method without and with 2 mol% excess of Na and Bi. X-ray diffraction patterns of NBLTF samples confirm perovskite structure having rhombohedral R3c phase symmetry. Metal oxide band observed at ~ 629 cm-1 wavnumber in FTIR spectra also confirm formation of perovskite phase in samples. Microstructural analysis exhibits dense crystal growth having better grains connectivity for NBLTF sample with 2 mol% excess Na/Bi which is supported by room temperature DC resistivity measurements. Dense crystal growth and low leakage current with 2 mol% excess Na/Bi is reported to improve multiferroic properties of NBLTF sample and provides new insight to explore single phase lead free multiferroic system.

  9. Diagnostic moléculaire du complexe Mycobacterium tuberculosis résistant à l'isoniazide et à la rifampicine au Burkina Faso

    PubMed Central

    Désire, Ilboudo; Cyrille, Bisseye; Florencia, Djigma; Souba, Diande; Albert, Yonli; Valerie, Bazie Jean Telesphore; Rebecca, Compaore; Charlemagne, Gnoula; Tamboura, Djibril; Rémy, Moret; Virginio, Pietra; Simplice, Karou Damintoti; Martial, Ouedraogo; Jacques, Simpore

    2015-01-01

    Introduction Cette étude a eu pour objectifs de diagnostiquer la tuberculose pulmonaire par l'examen microscopique et par la PCR des crachats et de déterminer les bases moléculaires de la résistance à la rifampicine et à l'isoniazide. Méthodes Le diagnostic du Complexe Mycobacterium Tuberculosis (CMTB) a été effectué par microscopie après coloration au Ziehl Nielsen et par PCR en temps réel en utilisant le kit d'identification du complexe MTB (Sacace Biotechnologie, Italie). Les résistances à la Rifampicine et à l'Isoniazide ont été étudiées par la technique de la PCR en utilisant le kit MTB résistance 8 (Sacace, Biotechnologie). Résultats Sur les 59 patients diagnostiqués pour la tuberculose pulmonaire, 59,3% étaient positifs en microscopie optique et 44,1% étaient positifs par PCR en Temps réel. Les résistances à la rifampicine (rpoB) et à l'isoniazide (katG et inhA) ont été observées chez 9 patients. La résistance à la rifampicine était due aux mutations (Asp516Val, Ser531Trp, Leu533Pro) et celle à l'isoniazide par les substitutions Ser315Thr du gène katG et C209T du gène inhA. Les multi résistances à la rifampicine et à l'isoniazide ont été observées dans 55,5% des échantillons et concernaient les associations: ropBAsp513Val + inhAC209T et rpoBLeu533Pro + katGSer315Thr. Conclusion La PCR en temps réel qui permet l'identification des allèles mutants rpoB, katG et inhA de M. tuberculosis est un outil de diagnostic épidémiologique de grande importance car elle permet de déterminer le niveau de résistance à la rifampicine et à l'isoniazide. PMID:26491516

  10. 5-Nitro-N 4,N 6-diphenyl­pyrimidine-4,6-diamine: polarized mol­ecules linked into π-stacked chains via three-centre C—H⋯(O)2 hydrogen bonds

    PubMed Central

    Rodríguez, Ricaurte; Nogueras, Manuel; Cobo, Justo; Glidewell, Christopher

    2009-01-01

    Mol­ecules of the title compound, C16H13N5O2, have no inter­nal symmetry despite the symmetric pattern of substitution in the pyrimidine ring. The intra­molecular distances indicate polarization of the electronic structure. There are two intra­molecular N—H⋯O hydrogen bonds and mol­ecules are linked into centrosymmetric dimers by pairs of three-centre C—H⋯(O)2 hydrogen bonds. These dimers are linked into chains by means of a π–π stacking inter­action. PMID:19726856

  11. Comment on "Synthesis, growth and characterization of a new metal-organic NLO material: Dibromo bis (L-proline) Cd(II)" [J. Mol. Struct. 1080 (2015) 37-43

    NASA Astrophysics Data System (ADS)

    Srinivasan, Bikshandarkoil R.; Naik, Madhavi Z.; Narvekar, Kedar U.

    2015-11-01

    The title paper by Boopathi and Ramasamy reports a study on the crystal growth and characterization of dibromobis(L-proline)cadmium(II) 1. Many points of criticism, concerning the crystal structure of 1 and the magnetic properties of 1, dibromobis(L-proline)zinc(II) 2 (J. Mol. Struc. 1033 (2013) 121-126) and diiodobis(2-aminopyridine)cadmium(II) 3 (J. Mol. Struc. 1042 (2013) 25-31) are described to show that compounds 1 to 3 are not soft magnets but instead diamagnetic solids.

  12. Measurement of direct CP violation parameters in B± → J/ψK± and B± → J/ψπ± decays with 10.4 fb-1 of Tevatron data.

    PubMed

    Abazov, V M; Abbott, B; Acharya, B S; Adams, M; Adams, T; Agnew, J P; Alexeev, G D; Alkhazov, G; Alton, A; Askew, A; Atkins, S; Augsten, K; Avila, C; Badaud, F; Bagby, L; Baldin, B; Bandurin, D V; Banerjee, S; Barberis, E; Baringer, P; Bartlett, J F; Bassler, U; Bazterra, V; Bean, A; Beattie, M; Begalli, M; Bellantoni, L; Beri, S B; Bernardi, G; Bernhard, R; Bertram, I; Besançon, M; Beuselinck, R; Bhat, P C; Bhatia, S; Bhatnagar, V; Blazey, G; Blessing, S; Bloom, K; Boehnlein, A; Boline, D; Boos, E E; Borissov, G; Brandt, A; Brandt, O; Brock, R; Bross, A; Brown, D; Bu, X B; Buehler, M; Buescher, V; Bunichev, V; Burdin, S; Buszello, C P; Camacho-Pérez, E; Casey, B C K; Castilla-Valdez, H; Caughron, S; Chakrabarti, S; Chan, K M; Chandra, A; Chapon, E; Chen, G; Cho, S W; Choi, S; Choudhary, B; Cihangir, S; Claes, D; Clutter, J; Cooke, M; Cooper, W E; Corcoran, M; Couderc, F; Cousinou, M-C; Cutts, D; Das, A; Davies, G; de Jong, S J; De La Cruz-Burelo, E; Déliot, F; Demina, R; Denisov, D; Denisov, S P; Desai, S; Deterre, C; DeVaughan, K; Diehl, H T; Diesburg, M; Ding, P F; Dominguez, A; Dubey, A; Dudko, L V; Duperrin, A; Dutt, S; Eads, M; Edmunds, D; Ellison, J; Elvira, V D; Enari, Y; Evans, H; Evdokimov, V N; Feng, L; Ferbel, T; Fiedler, F; Filthaut, F; Fisher, W; Fisk, H E; Fortner, M; Fox, H; Fuess, S; Garbincius, P H; Garcia-Bellido, A; García-González, J A; Gavrilov, V; Geng, W; Gerber, C E; Gershtein, Y; Ginther, G; Golovanov, G; Grannis, P D; Greder, S; Greenlee, H; Grenier, G; Gris, Ph; Grivaz, J-F; Grohsjean, A; Grünendahl, S; Grünewald, M W; Guillemin, T; Gutierrez, G; Gutierrez, P; Haley, J; Han, L; Harder, K; Harel, A; Hart, B; Hauptman, J M; Hays, J; Head, T; Hebbeker, T; Hedin, D; Hegab, H; Heinson, A P; Heintz, U; Hensel, C; Heredia-De La Cruz, I; Herner, K; Hesketh, G; Hildreth, M D; Hirosky, R; Hoang, T; Hobbs, J D; Hoeneisen, B; Hogan, J; Hohlfeld, M; Howley, I; Hubacek, Z; Hynek, V; Iashvili, I; Ilchenko, Y; Illingworth, R; Ito, A S; Jabeen, S; Jaffré, M; Jayasinghe, A; Holzbauer, J; Jeong, M S; Jesik, R; Jiang, P; Johns, K; Johnson, E; Johnson, M; Jonckheere, A; Jonsson, P; Joshi, J; Jung, A W; Juste, A; Kajfasz, E; Karmanov, D; Katsanos, I; Kehoe, R; Kermiche, S; Khalatyan, N; Khanov, A; Kharchilava, A; Kharzheev, Y N; Kiselevich, I; Kohli, J M; Kozelov, A V; Kraus, J; Kumar, A; Kupco, A; Kurča, T; Kuzmin, V A; Lammers, S; Lamont, I; Lebrun, P; Lee, H S; Lee, S W; Lee, W M; Lei, X; Lellouch, J; Li, D; Li, H; Li, L; Li, Q Z; Lim, J K; Lincoln, D; Linnemann, J; Lipaev, V V; Lipton, R; Liu, H; Liu, Y; Lobodenko, A; Lokajicek, M; Lopes de Sa, R; Luna-Garcia, R; Lyon, A L; Maciel, A K A; Madar, R; Magaña-Villalba, R; Malik, S; Malyshev, V L; Mansour, J; Martínez-Ortega, J; Mason, N; McCarthy, R; McGivern, C L; Meijer, M M; Melnitchouk, A; Menezes, D; Mercadante, P G; Merkin, M; Meyer, A; Meyer, J; Miconi, F; Mondal, N K; Mulhearn, M; Nagy, E; Narain, M; Nayyar, R; Neal, H A; Negret, J P; Neustroev, P; Nguyen, H T; Nunnemann, T; Orduna, J; Osman, N; Osta, J; Pal, A; Parashar, N; Parihar, V; Park, S K; Partridge, R; Parua, N; Patwa, A; Penning, B; Perfilov, M; Peters, Y; Petridis, K; Petrillo, G; Pétroff, P; Pleier, M-A; Podstavkov, V M; Popov, A V; Prewitt, M; Price, D; Prokopenko, N; Qian, J; Quadt, A; Quinn, B; Ratoff, P N; Razumov, I; Ripp-Baudot, I; Rizatdinova, F; Rominsky, M; Ross, A; Royon, C; Rubinov, P; Ruchti, R; Sajot, G; Sánchez-Hernández, A; Sanders, M P; Santos, A S; Savage, G; Sawyer, L; Scanlon, T; Schamberger, R D; Scheglov, Y; Schellman, H; Schwanenberger, C; Schwienhorst, R; Sekaric, J; Severini, H; Shabalina, E; Shary, V; Shaw, S; Shchukin, A A; Simak, V; Skubic, P; Slattery, P; Smirnov, D; Snow, G R; Snow, J; Snyder, S; Söldner-Rembold, S; Sonnenschein, L; Soustruznik, K; Stark, J; Stoyanova, D A; Strauss, M; Suter, L; Svoisky, P; Titov, M; Tokmenin, V V; Tsai, Y-T; Tsybychev, D; Tuchming, B; Tully, C; Uvarov, L; Uvarov, S; Uzunyan, S; Van Kooten, R; van Leeuwen, W M; Varelas, N; Varnes, E W; Vasilyev, I A; Verkheev, A Y; Vertogradov, L S; Verzocchi, M; Vesterinen, M; Vilanova, D; Vokac, P; Wahl, H D; Wang, M H L S; Warchol, J; Watts, G; Wayne, M; Weichert, J; Welty-Rieger, L; Williams, M R J; Wilson, G W; Wobisch, M; Wood, D R; Wyatt, T R; Xie, Y; Yamada, R; Yang, S; Yasuda, T; Yatsunenko, Y A; Ye, W; Ye, Z; Yin, H; Yip, K; Youn, S W; Yu, J M; Zennamo, J; Zhao, T G; Zhou, B; Zhu, J; Zielinski, M; Zieminska, D; Zivkovic, L

    2013-06-14

    We present a measurement of the direct CP-violating charge asymmetry in B(±) mesons decaying to J/ψK(±) and J/ψπ(±) where J/ψ decays to μ(+) μ(-), using the full run II data set of 10.4 fb(-1) of proton-antiproton collisions collected using the D0 detector at the Fermilab Tevatron Collider. A difference in the yield of B(-) and B(+) mesons in these decays is found by fitting to the difference between their reconstructed invariant mass distributions resulting in asymmetries of A(J/ψK) = [0.59 ± 0.37]%, which is the most precise measurement to date, and A(J/ψπ) = [-4.2 ± 4.5]%. Both measurements are consistent with standard model predictions. PMID:25165913

  13. Effect of boron oxide addition on fibre drawing, mechanical properties and dissolution behaviour of phosphate-based glass fibres with fixed 40, 45 and 50 mol% P2O5

    PubMed Central

    Sharmin, Nusrat; Parsons, Andrew J; Rudd, Chris D

    2014-01-01

    Previous studies investigating manufacture of phosphate-based glass fibres from glasses fixed with P2O5 content less than 50 mol% showed that continuous manufacture without breakage was very difficult. In this study, nine phosphate-based glass formulations from the system P2O5-CaO-Na2O-MgO-B2O3 were prepared with P2O5 contents fixed at 40, 45 and 50 mol%, where Na2O was replaced by 5 and 10 mol% B2O3 and MgO and CaO were fixed to 24 and 16 mol%, respectively. The effect of B2O3 addition on the fibre drawing, fibre mechanical properties and dissolution behaviour was investigated. It was found that addition of 5 and 10 mol% B2O3 enabled successful drawing of continuous fibres from glasses with phosphate (P2O5) contents fixed at 40, 45 and 50 mol%. The mechanical properties of the fibres were found to significantly increase with increasing B2O3 content. The highest tensile strength (1200 ± 130 MPa) was recorded for 45P2O5-16CaO-5Na2O-24MgO-10B2O3 glass fibres. The fibres were annealed, and a comparison of the mechanical properties and mode of degradation of annealed and non-annealed fibres were investigated. A decrease in tensile strength and an increase in tensile modulus were observed for the annealed fibres. An assessment of the change in mechanical properties of both the annealed and non-annealed fibres was performed in phosphate-buffered saline (PBS) at 37℃ for 28 and 60 days, respectively. Initial loss of mechanical properties due to annealing was found to be recovered with degradation. The B2O3-containing glass fibres were found to degrade at a much slower rate as compared to the non-B2O3-containing fibres. Both annealed and non-annealed fibres exhibited a peeling effect of the fibre's outer layer during degradation. PMID:24939962

  14. Report of pilot study CCM.P-P1 for international comparison of absolute pressure measurements in gas from 3 × 10-9 Pa to 9 × 10-4 Pa

    NASA Astrophysics Data System (ADS)

    Yoshida, Hajime; Arai, Kenta; Komatsu, Eiichi; Fujii, Kenichi; Bock, Thomas; Jousten, Karl

    2015-01-01

    A bilateral comparison of absolute gas pressure measurements from 3 × 10-9 Pa to 9 × 10-4 Pa was performed between the National Metrology Institute of Japan (NMIJ) and Physikalisch-Technische Bundesanstalt (PTB). It is a pilot study CCM.P-P1 for the next international comparison in this pressure range to test the stability of ultrahigh vacuum gauges (UHV gauges) as transfer standards. Two spinning rotor gauges (SRGs), an axial-symmetric transmission gauge (ATG), and an extractor gauge (EXG) were used as transfer standards. The calibration ratio of one SRG was sufficiently stable, but the other was not. This result indicates that improvements in the transport mechanism for SRG are needed. The two ionization gauges ATG and EXG, on the other hand, were sufficiently stable. Provisional equivalence of the pressures realized by the primary standards at NMIJ and PTB was found. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by CCM-WGS.

  15. Measurement of the φ*η distribution of muon pairs with masses between 30 and 500 GeV in 10.4 fb-1 of pp¯ collisions

    DOE PAGESBeta

    Abazov, Victor Mukhamedovich

    2015-04-06

    We present a measurement of the distribution of the variable φ*η for muon pairs with masses between 30 and 500 GeV, using the complete run II data set collected by the D0 detector at the Fermilab Tevatron proton-antiproton collider. This corresponds to an integrated luminosity of 10.4 fb–1 at √s = 1.96 TeV. The data are corrected for detector effects and presented in bins of dimuon rapidity and mass. The variable φ*η probes the same physical effects as the Z/γ* boson transverse momentum, but is less susceptible to the effects of experimental resolution and efficiency. These are the first measurementsmore » at any collider of the φ*η distributions for dilepton masses away from the Z → ℓ+ℓ– boson mass peak. As a result, the data are compared to QCD predictions based on the resummation of multiple soft gluons.« less

  16. Measurement of the φ*η distribution of muon pairs with masses between 30 and 500 GeV in 10.4 fb-1 of pp¯ collisions

    SciTech Connect

    Abazov, Victor Mukhamedovich

    2015-04-06

    We present a measurement of the distribution of the variable φ*η for muon pairs with masses between 30 and 500 GeV, using the complete run II data set collected by the D0 detector at the Fermilab Tevatron proton-antiproton collider. This corresponds to an integrated luminosity of 10.4 fb–1 at √s = 1.96 TeV. The data are corrected for detector effects and presented in bins of dimuon rapidity and mass. The variable φ*η probes the same physical effects as the Z/γ* boson transverse momentum, but is less susceptible to the effects of experimental resolution and efficiency. These are the first measurements at any collider of the φ*η distributions for dilepton masses away from the Z → ℓ+ boson mass peak. As a result, the data are compared to QCD predictions based on the resummation of multiple soft gluons.

  17. A novel vaccine p846 encoding Rv3615c, Mtb10.4, and Rv2660c elicits robust immune response and alleviates lung injury induced by Mycobacterium infection.

    PubMed

    Kong, Hongmei; Dong, Chunsheng; Xiong, Sidong

    2014-01-01

    Development of effective anti-tuberculosis (TB) vaccines is one of the important steps to improve control of TB. Cell-mediated immune response significantly affects the control of M. tuberculosis infection. Thus, vaccines able to elicit strong cellular immune response hold special advantages against TB. In this study, three well-defined mycobacterial antigens (Rv3615c, Mtb10.4 [Rv0228], and Rv2660c) were engineered as a novel triple-antigen fusion DNA vaccine p846. The p846 vaccine consists of a high density of CD4(+) and CD8(+) T-cell epitopes. Intramuscular immunization of p846 induced robust T cells mediated immune response comparable to that of bacillus Calmette-Guérin (BCG) vaccination but more effective than that of individual antigen vaccination. After mycobacterial challenge, p846 immunization decreased bacterial burden at least 15-fold compared with individual antigen-based vaccination. Notably, the lungs of mice immunized with p846 exhibited fewer inflammatory cell infiltrates and less damage than those of control group mice. Our data demonstrate that the potential of p846 vaccine to protect against TB and the feasibility of this design strategy for further TB vaccine development. PMID:24280763

  18. From 1.5 Meters to 10.4 Meters in 20 Years: Technological Evolution at the Instituto de Astrofísica de Canarias in the Development of Infrared Instrumentation for Terrestrial Telescopes

    NASA Astrophysics Data System (ADS)

    Caicoya, P. G. R.; Cabrera, M. B.; Izquierdo, P. F.; Patrón, J.; Sánchez de La Rosa, V.; Sangines, F. T.

    This paper reviews the evolution of the technical development of infrared instrumentation for terrestrial telescopes at the Instituto de Astrofísica de Canarias (IAC). The three most representative instruments, CAIN (installed on the 1.5 m Carlos Sánchez Telescope), LIRIS (on the 4.2 m William Herschel Telescope), and EMIR (on the 10.4 m Gran Telescopio Canarias) are described and compared. Each project entailed an improvement and a technological advance in relation to its predecessor. Larger optical beams brought larger lenses, larger mechanisms to hold them, stiffer and more massive support structures, and a scale factor upgrade of their cryostats. The evolution of infrared projects has been closely linked to the development of the manufacturing, assembly, integration and verification facilities at the IAC and has also had a strong influence on management techniques. As an indication of the growth in complexity of projects over time, this paper highlights the framework of available human resources, established consortia, timing and costs associated with the three instruments.

  19. New data on the presence of celestite into fossil bones from the uppermost Cretaceous Molí del Baró-1 site (Spain) and an alternative hypothesis on its origin

    NASA Astrophysics Data System (ADS)

    Piga, Giampaolo; Marmi, Josep; Galobart, Àngel; Brunetti, Antonio; Lasio, Barbara; Malfatti, Luca; Enzo, Stefano

    2016-05-01

    The Molí del Barò-1 site is located in south-central Pyrenees (Spain) and is dated to about 66.5 Ma (latest Cretaceous), just before the end Cretaceous mass extinction that wiped out most dinosaurs and many other groups of organisms. The site has yielded one of the richest fossil assemblages of the continental upper Maastrichtian from western Europe. A combined investigation by X-ray fluorescence (XRF), Fourier Transform Infrared spectroscopy attenuated total reflectance (FTIR-ATR) and powder X-ray diffraction (XRD), supplemented with the Rietveld analysis, was conducted on twenty-seven fossil bone samples from Molí del Baró-1 vertebrate-bearing fossil site to investigate taphonomy and diagenetic processes in terms of physico-chemical properties. The XRD analysis confirms the unusual presence of celestite and other rare sulphates in the bone structure. Previous explanations of the presence and sometimes abundance of celestite in the fossil bones from this site were based on the supposed total absence of marine water in the original depositionary environment. New geological information suggesting the possibility of marine influence allows formulating an alternative hypothesis focused on the peculiar environment of deposition of Molí del Baró-1 site.

  20. Interaction forces in thin liquid films stabilized by hydrophobically modified inulin polymeric surfactant. 2. Emulsion films.

    PubMed

    Exerowa, D; Gotchev, G; Kolarov, T; Khristov, Khr; Levecke, B; Tadros, Th

    2007-02-13

    The interaction forces in emulsion films stabilized using hydrophobically modified inulin (INUTEC SP1) were investigated by measuring the disjoining pressure of a microscopic horizontal film between two macroscopic emulsion drops of isoparaffinic oil (Isopar M). A special measuring cell was used for this purpose whereby the disjoining pressure Pi was measured as a function of the equivalent film thickness hw. The latter was determined using an interferometric method. In this way Pi-hw curves were established at a constant INUTEC SP1 concentration of 2x10(-5) mol.dm-3 and at various NaCl concentrations. At a constant disjoining pressure of 36 Pa, a constant temperature of 22 degrees C, and a film radius of 100 microm, hw decreased with an increase in the NaCl concentration, Cel, and reached a constant value of 11 nm at Cel=5x10(-2) mol.dm-3. This reduction in film thickness is due to the compression of the electrical double layer, and at the above critical NaCl concentration any electrostatic repulsion is removed and only steric interaction remains. This critical electrolyte concentration represents the transition from electrostatic to steric interaction. At a NaCl concentration of 2x10(-4) mol.dm-3 the Pi-hw isotherms showed a gradual decrease in hw with an increase in capillary pressure, after which there was a jump in hw from approximately 30 to approximately 7.2 nm when Pi reached a high value of 2-5.5 kPa. This jump is due to the formation of a Newton black film (NBF), giving a layer thickness of the polyfructose loops of approximately 3.6 nm. The film thickness did not change further when the pressure reached 45 kPa, indicating the high stability of the film. Pi-hw isotherms were obtained at various NaCl concentrations, namely, 5x10(-2), 5x10(-1), 1.0, and 2.0 mol.dm-3. The initial thicknesses are within the range 9-11 nm, after which a transition zone starts, corresponding to a pressure of about 0.5 kPa. In this zone all films transform to an NBF with a jump

  1. Estudio comparativo de las moléculas isovalentes de interés atmosférico CF3Cl y CF3Br y sus correspondientes halógenos aislados Cl y Br.

    NASA Astrophysics Data System (ADS)

    Mayor, E.; Velasco, A. M.; Martín, I.; Lavín, C.

    Los estados Rydberg moleculares han suscitado en los últimos años un creciente interés entre los espectroscopistas experimentales, motivado en parte por el desarrollo de nuevas técnicas espectroscópicas capaces de investigar estos estados altamente excitados electrónicamente. Los procesos de fotoabsorción que implican estados Rydberg en los derivados halogenados del metano son de gran importancia, debido a su abundancia en la atmósfera y a sus implicaciones medioambientales. Por ello, la obtención de datos relativos a sus fuerzas de oscilador es de gran interés. En este trabajo se aborda el estudio de dichas propiedades para las moléculas isovalentes CF3Cl y CF3Br. Ambas moléculas presentan idéntica estructura electrónica para el estado fundamental por lo que se espera que sus espectros Rydberg presenten grandes similitudes, en ausencia de perturbaciones. Por ello y dada la escasez de datos relativos a fuerzas de oscilador, hemos establecido la corrección de nuestros resultados en base a las analogías esperadas en las intensidades espectrales correspondientes a transiciones análogas. Por otro lado, Novak y col. [1] han encontrado experimentalmente un marcado carácter atómico en el espectro correspondiente a estas moléculas, siendo muy similar a los de los átomos de Cl y Br. Por ello en el presente trabajo, además de establecer la comparación entre ambas moléculas hemos buscado las similitudes con sus respectivos halógenos. Los cálculos relativos a las especies moleculares se han realizado utilizando la Metodología Molécular de Orbítales de Defecto Cuántico (MQDO) [2], mientras que para el estudio de los átomos de Cl y Br se empleó la versión relativista del método (RQDO) [3].

  2. Demographical, Clinical, and Psychological Characteristics of Users and Nonusers of an Online Platform for T2DM Patients (e-VitaDM-3/ZODIAC-44)

    PubMed Central

    Roelofsen, Yvonne; van Vugt, Michael; Hendriks, Steven H.; van Hateren, Kornelis J. J.; Groenier, Klaas H.; Snoek, Frank J.; Kleefstra, Nanne; Huijsman, Robbert; Bilo, Henk J. G.

    2016-01-01

    Background. Online platforms offer opportunities for support in changing lifestyle and taking responsibility for one's health, but engaging patients with type 2 diabetes is challenging. Previous studies have shown that patients interested in platforms were more often male, younger, and higher educated. This study aims to investigate differences in clinical and psychological characteristics between users and nonusers of a newly developed platform. Methods. A prospective study started in the Drenthe region of Netherlands. Participants in the study concerning quality of care and quality of life were additionally invited to use the platform. Results. 633 patients were registered after they opted for platform use. Of these patients, 361 (57.0%) never logged on, 184 (29.1%) were labeled “curious” users, and 88 (13.9%) were identified as “active” users. Users had lower HbA1c levels and more often hypertension compared to nonusers, and reported higher quality of life, better well-being, lower diabetes-related distress, and better medication adherence. Discussion. Platform use was associated with more favorable clinical and psychological characteristics relative to nonuse. Those with greater severity of disease, lower mood, and progression of disease used the platform the least. Other approaches need to be developed to reach these patients. Furthermore, improving the platform could also help to reach them. This trial is registered with Clinicaltrials.gov NCT01570140. PMID:26682232

  3. Formation of studtite during the oxidative dissolution of UO2 by hydrogen peroxide: a SFM study.

    PubMed

    Clarens, F; de Pablo, J; Díez-Pérez, I; Casas, I; Giménez, J; Rovira, M

    2004-12-15

    Understanding the formation of alteration phases on the surface of spent nuclear fuel, such as those observed during leaching experiments, is necessary in order to predict the concentration of radionuclides in the near-field of a final repository. Hydrogen peroxide has been identified as one of the oxidants formed by the radiolysis of water in the presence of spent nuclear fuel; especially due to alpha activity. The presence of this species in solution can contribute to the formation of uranium peroxide secondary phases. In this work, we have studied the oxidative dissolution of synthetic UO2 disks in hydrogen peroxide solutions of two different concentrations (5 x 10(-4) and 5 x 10(-6) mol dm(-3)), both at pH 5.8 +/- 0.1. The solid surface evolution of the disks has been followed by means of ex-situ scanning force microscope (SFM) measurements, and uranium concentration in solution has been determined by inductively coupled plasma mass spectrometry. During the first stage of the experiment, SFM images indicate that only UO2 dissolution is occurring. After 142 h, a secondary phase is observed on the surface of the solid at 5 x 10(-4) mol dm(-3) hydrogen peroxide concentration. This secondary phase has been identified by X-ray diffraction as studtite (UO4 x 4H2O). From the analysis of SFM topographic profiles at different elapsed times, a precipitation rate for the studtite has been estimated to be in the range of (8-32) x 10(-10) mol m(-2) s(-1). PMID:15669324

  4. New photophysical insights in noncovalent interaction between fulleropyrrolidine and a series of zincphthalocyanines.

    PubMed

    Ray, Anamika; Santhosh, Kotni; Bhattacharya, Sumanta

    2011-09-01

    The present article reports, for the first time, the photophysical aspects of noncovalent interaction of a fullerene derivative, namely, C(60) pyrrolidine tris-acid ethyl ester (PyC(60)) with a series of zincphthalocyanines, for example, underivatized zincphthalocyanine (1), zinc-1,4,8,11,15,18,22,25-octabutoxy-29H,31H-phthalocyanine (2), and zinc-2,3,9,10,16,17,23,24-octakis-(octyloxy)-29H,31H-phthalocyanine (3) in toluene. Ground state electronic interaction of PyC(60) with 1, 2 and 3 has been evidenced from the observation of well-defined charge transfer (CT) absorption bands in the visible region. Utilizing the CT transition energy, vertical electron affinity (E(A)(v)) of PyC(60) is determined. Steady state fluorescence experiment enables us to determine the value of binding constant (K) in the magnitude of 2.60 × 10(4) dm(3mol(-1), 2.20 × 10(4) dm(3mol(-1), and 1.27 × 10(4) dm(3mol(-1) for the noncovalent complexes of PyC(60) with 1, 2, and 3, respectively. K values of PyC(60)-ZnPc complexes suggest that PyC(60) is incapable of discriminating between 1, 2, and 3 in solution. Lifetime experiment signifies the importance of static quenching phenomenon for our presently investigated supramolecules and it yields larger magnitude of charge separated rate constant for the PyC(60)-1 species in toluene. Photoinduced energy transfer between PyC(60) and ZnPc derivatives, namely, 1, 2, and 3, in toluene, has been evidenced with nanosecond laser photolysis method by observing the transient absorption bands in the visible region; transient absorption studies establish that energy transfer from (T)PyC(60)* to the ZnPc occurs predominantly, as confirmed by the consecutive appearance of the triplet states of PyC(60). Theoretical calculations at semiempirical level (PM3) evoke the single projection geometric structures for the PyC(60)-ZnPc systems in vacuo, which also proves that interaction between PyC(60) and ZnPc is governed by the electrostatic mechanism rather

  5. Structural analysis of xSrO-(50 - x)CaO-50P2O5 glasses with x=0, 5, or 10 mol% for potential use in a local delivery system for osteomyelitis treatment.

    PubMed

    Comeau, P A; Filiaggi, M J

    2016-01-01

    The introduction of ions into a local delivery matrix is one method of managing degradation and subsequent release of the incorporated therapeutic agents. Of interest in this study was whether we could modify the structural nature of calcium polyphosphate (CPP) glass and the subsequent therapeutic potential of this local delivery matrix with inclusion of strontium (Sr). We found that adding 10 mol% Sr significantly increased the density and chain length of the glass. There was no significant impact of Sr doping on the subsequent loading of vancomycin into the matrix, or the matrix porosity. The noted differences in structural stability, ion release, and vancomycin release between the un-doped CPP matrices and 10 mol% Sr-doped CPP matrices in vitro are likely a result of a decrease in glass disorder upon Sr addition to the glass and preferential retention of Sr over Ca during matrix degradation. This study has provided further evidence that Sr incorporation may serve to both manipulate antibiotic release from the amorphous CPP matrix and provide a potential source of therapeutic ions for enhanced bone regeneration. PMID:26478355

  6. KEY COMPARISON: Final report on international key comparison CCQM-K65: Gas standards containing methyl and ethyl mercaptans (at the level of 20-30 µmol/mol) in methane

    NASA Astrophysics Data System (ADS)

    Konopelko, L. A.; Kustikov, Y. A.; Vishnyakov, I. M.; Pavlov, M. V.; Efremova, O. V.; Woo, Jin-Chun; Kim, Yong-Doo; Wessel, Rob M.; Ziel, Paul R.; Milton, Martin J. T.; Vargha, G.; Brown, A.; Uprichard, Ian

    2010-01-01

    The key comparison CCQM-K65 was intended to compare the capabilities for the preparation and value assignment of gas standards for methyl and ethyl mercaptans in methane, maintained at the participating national metrological institutes: VNIIM (Russia), KRISS (Korea), VSL (Netherlands) and NPL (United Kingdom). The range of the nominal amount of substance fractions of the comparison gas mixtures was 20 µmol/mol to 30 µmol/mol, which is close to regulatory level (in several countries including Russia) for mercaptans in odorated natural gas. This comparison was proposed at the 12th GAWG meeting in October 2004 and was conducted in 2008. Conclusions are as follows: The results of all laboratories are consistent with the reference values. The observed differences between the reference and reported values are within +/-0.9% for methyl mercaptan and +/-0.75% for ethyl mercaptan relative to the gravimetric values, and do not exceed the appropriate assigned expanded uncertainties. The prepared mixtures were found to be stable during about a year within the uncertainty of the measurements. The gravimetric values were successfully validated with a dynamic method. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (MRA).

  7. Final report on COOMET.QM-S1 (COOMET project no 483/RU/09): Supplementary comparison of primary standard gas mixtures: Nitrogen monoxide in nitrogen (50 µmol/mol)

    NASA Astrophysics Data System (ADS)

    Konopelko, L. A.; Kustikov, Y. A.; Kolobova, A. V.; Shor, N. B.; Efremova, O. V.; Rozhnov, M. S.; Melnyk, D. M.; Kozia, V. G.; Shpilnyi, S. A.; Petryshyn, P. V.; Iakubov, S. E.; Kluchits, A. S.; Ananyin, V. N.; Mironchik, A. M.; Mokhnach, M. V.; Valkova, M.; Stovcik, V.; Walden, J.; Augusto, C. R.; Fioravante, A. L.; Ribeiro, C. C.; Sobrinho, D. C. G.; Oudwater, R. J.; da Cunha, V. S.

    2014-01-01

    Nitrogen monoxide is one of the main contaminants present in the atmospheric air due to emissions of vehicles and power stations. Taking into account the positive experience of VNIIM in the pilot study CCQM-P73 (Nitrogen monoxide gas standards, 30 µmol/mol to 70 µmol/mol), a COOMET project (No 483/RU/09) on the subject was decided and registered in the KCDB as supplementary comparison COOMET.QM-S1. This involved six National Metrology Institutes, aiming to consolidate or support their Calibration and Measurement Capabilities in this field. It was found that most of the results were consistent with the reference (gravimetric) values, with observed differences not exceeding ±1.3% and not exceeding either the appropriate assigned expanded uncertainties. There was, however, one exception: the INMETRO difference from the reference value is slightly higher than the expended uncertainty. The mixtures prepared for this exercise were found to be stable during about one year within the uncertainty of the measurements. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by COOMET, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

  8. Translational, vibrational, rotational enhancements and alignments of reactions H + ClF (v = 0-5, j = 0,3,6,9) → HCl + F and HF + Cl, at Erel = 0.5-20 kcal/mol

    NASA Astrophysics Data System (ADS)

    Victor Wei-Keh, Chao(Wu

    2013-10-01

    Quasi-classical trajectory calculations of the title reactions H + ClF (v = 0-5, j = 0,3,6,9) → HCl + F and H + ClF (v = 0-5, j = 0,3,6,9) → HF + Cl at Erel = 0.5 kcal/mol-20 kcal/mol on ground potential energy surface DHTSN of 1 2A' [M. P. Deskevich, M. Y. Hayes, K. Takahashi, R. T. Skodje and D. J. Nesbitt, J. Chem. Phys. 124, 224303 (2006)] are performed. Potential energy surfaces derived from DHTSN for the title reactions are obtained, and compared with that of DHTSN for the reaction F + HCl → HF + Cl. Both potential energy surfaces have an early barrier pattern. Integral cross sections and alignments of product molecules HCl and HF dependent on the internal energy states v and j of reactant molecule ClF are obtained and compared. Translational, vibrational, and rotational energy specific translational enhancements of the reactant molecule ClF of the title reactions are found. Reaction mechanisms of the title reactions according to the respective potential energy contours are further found and explained. Reasons of simultaneous translational and vibrational enhancements are clarified.

  9. Mol-Gastronomie Vinaigrettes und Benetzung

    NASA Astrophysics Data System (ADS)

    Vilgis, Thomas

    2005-03-01

    Dass wir Salatblätter mit einer Vinaigrette übergießen, hat natürlich einen kulinarischen Grund: Die Kombination von Essig und Öl verleiht Salat erheblich an Geschmack. Nicht nur durch deren Eigengeschmack, sondern auch durch die Lösungseigenschaften von Geschmacksstoffen. Allerdings liefern Salatsaucen auch einen physikalischen Grund für ihre Beliebtheit: die Benetzungsfähigkeit der Blätter.

  10. Study of the interactions of molten sodium nitrate-potassium nitrate 50 mol % mixture with water vapor and carbon dioxide in air. Final report, June 2, 1980-June 30, 1981

    SciTech Connect

    White, S.H.; Twardoch, U.M.

    1981-09-01

    The interactions of aerial components such as water, carbon dioxide, and oxygen with the binary 50 mol % mixture of sodium nitrate and potassium nitrate have been studied in the temperature range 300 to 600/sup 0/C using electrochemical methods. In addition, the behavior of nitrite ions in this melt was investigated electrochemically. By judicious choice of techniques, in situ electroanalysis was possible and the necessary relevant data to accomplish this is presented, as well as insight into the corresponding electrochemical mechanisms associated with the electroactive species. The influence of each atmospheric component was examined separately. At temperatures above 300/sup 0/C, nitrite ions are found to accumulate due to thermal decomposition of the nitrate. Water is highly soluble in the salt mixture, but no hydrolytic reactions were observed. Two methods of in situ analysis for water are described. Pure carbon dioxide is found to attack the melt at all temperatures above 250/sup 0/C producing carbonate. (LEW)

  11. Different cation-protonation patterns in mol­ecular salts of unsymmetrical dimethyhydrazine: C2H9N2·Br and C2H9N2·H2PO3

    PubMed Central

    Katinaitė, Judita; Harrison, William T. A.

    2016-01-01

    We describe the syntheses and crystal structures of two mol­ecular salts containing the 1,1-di­methyl­hydrazinium cation, namely 1,1-di­methyl­hydrazin-1-ium bromide, C2H9N2 +·Br−, (I), and 2,2-di­methyl­hydrazin-1-ium di­hydrogen phosphite, C2H9N2 +·H2PO3 −, (II). In (I), the cation is protonated at the methyl­ated N atom and N—H⋯Br hydrogen bonds generate [010] chains in the crystal. In (II), the cation is protonated at the terminal N atom and cation-to-anion N—H⋯O and anion-to-anion O—H⋯O hydrogen bonds generate (001) sheets. PMID:27536415

  12. Different cation-protonation patterns in mol-ecular salts of unsymmetrical dimethyhydrazine: C2H9N2·Br and C2H9N2·H2PO3.

    PubMed

    Katinaitė, Judita; Harrison, William T A

    2016-08-01

    We describe the syntheses and crystal structures of two mol-ecular salts containing the 1,1-di-methyl-hydrazinium cation, namely 1,1-di-methyl-hydrazin-1-ium bromide, C2H9N2 (+)·Br(-), (I), and 2,2-di-methyl-hydrazin-1-ium di-hydrogen phosphite, C2H9N2 (+)·H2PO3 (-), (II). In (I), the cation is protonated at the methyl-ated N atom and N-H⋯Br hydrogen bonds generate [010] chains in the crystal. In (II), the cation is protonated at the terminal N atom and cation-to-anion N-H⋯O and anion-to-anion O-H⋯O hydrogen bonds generate (001) sheets. PMID:27536415

  13. Thermo-optic dispersion formula for the ordinary wave in 5 mol% MgO doped LiNbO3 and its application to temperature insensitive second-harmonic generation

    NASA Astrophysics Data System (ADS)

    Umemura, Nobuhiro; Matsuda, Daisuke

    2016-05-01

    We report the high accuracy thermo-optic dispersion formula for the ordinary wave of 5 mol% MgO doped congruent LiNbO3 (MgO:LiNbO3), which reproduces well our experimental data for the temperature-dependent birefringent phase-matching (BPM) and quasi-phase-matching (QPM) conditions with the oo-e, oo-o, and oe-o interactions in the 0.41-3.7 μm range. In addition, we found the temperature insensitive quasi-phase-matched second-harmonic generation (QPM/SHG) points exist in periodically poled MgO:LiNbO3 (MgO:PPLN) with the oo-o and oe-o interactions for the first time.

  14. Oxygen isotope systematics in the aragonite-CO2-H2O-NaCl system up to 0.7 mol/kg ionic strength at 25 °C

    USGS Publications Warehouse

    Kim, Sang-Tae; Gebbinck, Christa Klein; Mucci, Alfonso; Coplen, Tyler B.

    2014-01-01

    To investigate the oxygen isotope systematics in the aragonite-CO2-H2O-NaCl system, witherite (BaCO3) was precipitated quasi-instantaneously and quantitatively from Na-Cl-Ba-CO2 solutions of seawater-like ionic strength (I = 0.7 mol/kg) at two pH values (~7.9 and ~10.6) at 25 °C. The oxygen isotope composition of the witherite and the dissolved inorganic carbon speciation in the starting solution were used to estimate the oxygen isotope fractionations between HCO3¯ and H2O as well as between CO3 2 and H2O. Given the analytical error on the oxygen isotope composition of the witherite and uncertainties of the parent solution pH and speciation, oxygen isotope fractionation between NaHCO3° and HCO3¯, as well as between NaCO3¯ and CO3 2, is negligible under the experimental conditions investigated. The influence of dissolved NaCl concentration on the oxygen isotope fractionation in the aragonite-CO2-H2O-NaCl system also was investigated at 25 °C. Aragonite was precipitated from Na-Cl-Ca-Mg-(B)-CO2 solutions of seawater-like ionic strength using passive CO2 degassing or constant addition methods. Based upon our new experimental observations and published experimental data from lower ionic strength solutions by Kim et al. (2007b), the equilibrium aragonite-water oxygen isotope fractionation factor is independent of the ionic strength of the parent solution up to 0.7 mol/kg. Hence, our study also suggests that the aragonite precipitation mechanism is not affected by the presence of sodium and chloride ions in the parent solution over the range of concentrations investigated.

  15. Localization of the genes for the two chlorophyll a-conjugated polypeptides (mol. wt. 51 and 44 kd) of the photosystem II reaction center on the spinach plastid chromosome.

    PubMed

    Westhoff, P; Alt, J; Herrmann, R G

    1983-01-01

    A core particle of the water-oxidizing photosystem II reaction center has been prepared from stacked spinach thylakoid membranes by a procedure involving extraction with the non-ionic detergent dodecyl-beta-D-maltoside and centrifugation in sucrose gradients. The protein-pigment complex consists of at least four polypeptide species: two components with mol. wts. of 51 and 44 kd which are conjugated with chlorophyll a and beta-carotene, the herbicide-binding protein of mol. wt. 32 kd and cytochrome b 559 (11 kd). The genes for the 51-and 44-kd polypeptides have been located on the circular 150-kbp spinach plastid chromosome. They were identified by hybrid-selection mapping, in vitro transcription-translation of recombinant DNAs and specific antisera which were used to characterize the translation products. The plastid chromosome carries one uninterrupted copy for each of these genes in its large single-copy region. The gene for the 51-kd protein (which probably bears the P(680) reaction center chlorophyll a) is located in close proximity to the gene for cytochrome b6, and some 70 kbp away from the gene for the ;32-kd' herbicide-binding protein of the reducing side of photosystem II. The gene for the 44-kd protein is situated halfway between these two genes adjacent to the gene for the P(700) chlorophyll a apoprotein of the photosystem I reaction center. Both photosystem II genes are transcribed into discrete RNA species in the same direction but from the opposite strand as the gene for the ;32-kd' protein. PMID:16453486

  16. Contribution of seismic processing to put up the scaffolding for the 3-dimensional study of deep sedimentary basins: the fundaments of trans-national 3D modelling in the project GeoMol

    NASA Astrophysics Data System (ADS)

    Capar, Laure

    2013-04-01

    Within the framework of the transnational project GeoMol geophysical and geological information on the entire Molasse Basin and on the Po Basin are gathered to build consistent cross-border 3D geological models based on borehole evidence and seismic data. Benefiting from important progress in seismic processing, these new models will provide some answers to various questions regarding the usage of subsurface resources, as there are geothermal energy, CO2 and gas storage, oil and gas production, and support decisions-making to national and local administrations as well as to industries. More than 28 000 km of 2D seismic lines are compiled reprocessed and harmonized. This work faces various problems like the vertical drop of more than 700 meters between West and East of the Molasse Basin and to al lesser extent in the Po Plain, the heterogeneities of the substratum, the large disparities between the period and parameters of seismic acquisition, and depending of their availability, the use of two types of seismic data, raw and processed seismic data. The main challenge is to harmonize all lines at the same reference level, amplitude and step of signal processing from France to Austria, spanning more than 1000 km, to avoid misfits at crossing points between seismic lines and artifacts at the country borders, facilitating the interpretation of the various geological layers in the Molasse Basin and Po Basin. A generalized stratigraphic column for the two basins is set up, representing all geological layers relevant to subsurface usage. This stratigraphy constitutes the harmonized framework for seismic reprocessing. In general, processed seismic data is available on paper at stack stage and the mandatory information to take these seismic lines to the final stage of processing, the migration step, are datum plane and replacement velocity. However several datum planes and replacement velocities were used during previous processing projects. Our processing sequence is to

  17. Spectroscopic studies, fluorescence quenching by molecular oxygen and amplified spontaneous emission of 1,4-bis [2-(2-pyridyl) vinyl] benzene (P2VB) diolefinic laser dye

    NASA Astrophysics Data System (ADS)

    El-Daly, Samy A.; Ebeid, E. M.

    2014-04-01

    The UV-visible electronic absorption spectra, molar absorptivity, fluorescence spectra, fluorescence quantum yield and excited state lifetime of 1,4-bis [2-(2-pyridyl) vinyl] benzene P2VB were measured in different solvents. The fluorescence quenching of P2VB by molecular oxygen was also studied using lifetime measurements. A 2 × 10-4 mol dm-3 solution of P2VB in dimethyl formamide (DMF) gave amplified spontaneous emission (ASE) in blue spectral region with emission maximum at 420 nm upon pumping by 337.1 nitrogen laser pulse. The photochemical quantum yields (ϕc) of trans-cis photoisomerization of P2VB were calculated in different organic solvents. The photoreactivity of P2VB are also studied PMMA matrix.

  18. Radiolysis of solutions containing organo-disulphides

    NASA Astrophysics Data System (ADS)

    Elliot, Allen John; Simsons, Anita Sandra; Sopchyshyn, Frederick Charles

    When oxidized dithiothreitol (DTT- ox), oxidized gluthathione (GSSG), or dithiodiproprionic acid is radiolysed in N 2O-saturated sodium formate solutions, a chain reduction of the disulphide to the corresponding thiol occurs. The chain propagating step is the abstraction of the hydrogen atom in the formate ion by the thiyl radical. For the dithiothreitol thiyl radical, the rate constant for the abstraction is ≥ 3.6 × 10 4 mol -1 dm 3 s -1. The more sterically hindered penicillamine disulphide does not undergo this chain reaction. While the (CH 3) 2ĊOH radical does not reduce DTT- ox, it reduces GSSG to glutathione. At pH 9, the acetone radical anion, (CH 3) 2ĊO -, reduces both DTT- ox and GSSG.

  19. Degradation of the herbicide 2, 4-dichlorophenoxyacetic acid (2,4-D) dimethylamine salt by gamma radiation from cobalt-60 in aqueous solution containing humic acid

    NASA Astrophysics Data System (ADS)

    Campos, Sandro X.; Vieira, Eny M.; Cordeiro, Paulo J. M.; Rodrigues-Fo, Edson; Murgu, Michael

    2003-12-01

    In this study, gamma radiation from cobalt-60 was used to degrade the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) dimethylamine salt in water in the presence of humic acid. The 2,4-D dimethylamine salt 1.13×10 -4 mol dm -3 solution was irradiated with different doses. HPLC was used as an analytical technique to determine the degradation rate of herbicide studied. The results showed that the herbicide was completely degraded at an absorbed dose of 3 kGy. Degradation decreased when humic acid was added to all the doses. ESI/MS and MS/MS were used to identify the radiolytic degradation products. A fragmentation path for production of 4.6-dichlororesorcinol, is suggested. The radiolytic yields ( G) were calculated.

  20. Contribution of seismic processing to put up the scaffolding for the 3-dimensional study of deep sedimentary basins: the fundaments of trans-national 3D modelling in the project GeoMol

    NASA Astrophysics Data System (ADS)

    Capar, Laure

    2013-04-01

    Within the framework of the transnational project GeoMol geophysical and geological information on the entire Molasse Basin and on the Po Basin are gathered to build consistent cross-border 3D geological models based on borehole evidence and seismic data. Benefiting from important progress in seismic processing, these new models will provide some answers to various questions regarding the usage of subsurface resources, as there are geothermal energy, CO2 and gas storage, oil and gas production, and support decisions-making to national and local administrations as well as to industries. More than 28 000 km of 2D seismic lines are compiled reprocessed and harmonized. This work faces various problems like the vertical drop of more than 700 meters between West and East of the Molasse Basin and to al lesser extent in the Po Plain, the heterogeneities of the substratum, the large disparities between the period and parameters of seismic acquisition, and depending of their availability, the use of two types of seismic data, raw and processed seismic data. The main challenge is to harmonize all lines at the same reference level, amplitude and step of signal processing from France to Austria, spanning more than 1000 km, to avoid misfits at crossing points between seismic lines and artifacts at the country borders, facilitating the interpretation of the various geological layers in the Molasse Basin and Po Basin. A generalized stratigraphic column for the two basins is set up, representing all geological layers relevant to subsurface usage. This stratigraphy constitutes the harmonized framework for seismic reprocessing. In general, processed seismic data is available on paper at stack stage and the mandatory information to take these seismic lines to the final stage of processing, the migration step, are datum plane and replacement velocity. However several datum planes and replacement velocities were used during previous processing projects. Our processing sequence is to

  1. Multi-approach mapping to help spatial planning and management of the kelp species L. digitata and L. hyperborea: Case study of the Molène Archipelago, Brittany

    NASA Astrophysics Data System (ADS)

    Bajjouk, Touria; Rochette, Sébastien; Laurans, Martial; Ehrhold, Axel; Hamdi, Anouar; Le Niliot, Philippe

    2015-06-01

    The Molène Archipelago in Brittany (France) hosts one of the largest kelp forests in Europe. Beyond their recognized ecological importance as an essential habitat and food for a variety of marine species, kelp also contributes towards regional economies by means of the alginate industry. Thousands of tons of kelp are collected each year for the needs of the chemical and food industries. Kelp harvesting in Brittany mainly concerns two species, Laminaria digitata (59,000 t) and Laminaria hyperborea (24,000 t), that, together, represent approximately 95% of the national landings. Estimating the available standing stock and its distribution is a clear need for providing appropriate and sustainable management measures. Prior to estimating the spatial distribution of biomasses, we produced a detailed seabed topography map with accurate hard substrate delineation thanks to surveys and appropriate processing of airborne optical and acoustic imaging. Habitat suitability models of presence-absence and biomass were then developed for each species by relating in situ observations from underwater video and sampling to the many biotic and abiotic factors that may govern kelp species distribution. Our statistical approach combining generalized additive models (GAM) in a delta approach also provided spatial uncertainty associated with each prediction to help management decisions. This study confirmed that the adopted strategy, based on an integrated approach, enhanced knowledge on kelp biomass distributions in the Molène Archipelago and provided a promising direct link between research and management. Indeed, the high resolution topography and hard substrate maps produced for the study greatly improved knowledge on the sea bottom of the area. This was also of major importance for an accurate mapping of kelp distribution. The quality of the habitat suitability models was verified with fishing effort data (RECOPESCA program) and confirmed by local managers and kelp harvesters

  2. Postnatal - physiological research of the bronchial receptor system development on the isolated preparation of the human trachea in vitro.

    PubMed

    Sukalo, Aziz; Islami, Hilmi; Shabani, Ragib; Dauti, Hilmi; Kutllovci, Skender; Kastrati, Bashkim

    2006-08-01

    Research was done on pharmacological-physiological development of the bronchial receptor system on the smooth muscles of trachea in the newborn children, alive-born and stillborn children. Monitored was the response on: acetylcholine, dopamine, histamine and serotonin in different molar concentrations 10(-4), 10(-3), 10(-2), 10 mol/dm(-3), micromol/dm(-3)). Research was done on tonus of tracheal smooth muscles of 23 tracheal preparations taken by autopsy after death from different factors. Based on pharmacological-physiological research on the preparations of human isolated trachea it was find out that: acetylcholine stimulation effect is significant (p>0,01) in 38-41 weeks of pregnancy comparing with that in 30-37 weeks of pregnancy (p>0,01), while dopamine stimulation effect is significant (p>0,05) in 30-37 pregnancy weeks comparing with the effect of acetylcholine and dopamine on the still-born infants of the same pregnancy period (p<0,01). Histaminic receptors were developed during intrauterine life after 38 weeks of pregnancy (p>0,025). Serotonin has caused contraction of the bronchial smooth muscles after 30 pregnancy weeks, but response was not significant (p<0,01). This suggests that cholinergic and adrenergic system of the airways in alive newborn infants develops in parallel intrauterine, contrary to other systems which develop in certain extrauterine life phases. PMID:16995853

  3. Strongly enhanced vortex pinning from 4 to 77 K in magnetic fields up to 31 T in 15 mol.% Zr-added (Gd, Y)-Ba-Cu-O superconducting tapes

    SciTech Connect

    Xu, A; Delgado, L; Khatri, N; Liu, Y; Selvamanickam, V; Abraimov, D; Jaroszynski, J; Kametani, F; Larbalestier, DC

    2014-04-01

    Applications of REBCO coated conductors are now being developed for a very wide range of temperatures and magnetic fields and it is not yet clear whether vortex pinning strategies aimed for high temperature, low field operation are equally valid at lower temperatures and higher fields. A detailed characterization of the superconducting properties of a 15 mol.% Zr-added REBCO thin film made by metal organic chemical vapor deposition, from 4.2 to 77 K under magnetic fields up to 31 T is presented in this article. Even at a such high level of Zr addition, T-c depression has been avoided (T-c = 91 K), while at the same time an exceptionally high irreversibility field H-irr approximate to 14.8 T at 77 K and a remarkably high vortex pinning force density F-p approximate to 1.7 TN/m(3) at 4.2 K have been achieved. We ascribe the excellent pinning performance at high temperatures to the high density (equivalent vortex matching field similar to 7 T) of self-assembled BZO nanorods, while the low temperature pinning force is enhanced by large additional pinning which we ascribe to strain-induced point defects induced in the REBCO matrix by the BZO nanorods. Our results suggest even more room for further performance enhancement of commercial REBCO coated conductors and point the way to REBCO coil applications at liquid nitrogen temperatures since the critical current density J(c)(H//c) characteristic at 77 K are now almost identical to those of fully optimized Nb-Ti at 4 K. (C) 2014 Author(s).

  4. Gd(1.96-x)Y(x)Eu0.04O3 (x = 0.0, 0.49, 0.98, 1.47, 1.96 mol%) nanophosphors: propellant combustion synthesis, structural and luminescence studies.

    PubMed

    Shilpa, C J; Dhananjaya, N; Nagabhushana, H; Sharma, S C; Shivakumara, C; Sudheerkumar, K H; Nagabhushana, B M; Chakradhar, R P S

    2014-07-15

    Gd(1.96-x)Y(x)Eu0.04O3 (x = 0.0, 0.49, 0.98, 1.47, 1.96 mol%) nanophosphors were synthesized by propellant combustion method at low temperature (400°C). The powder X-ray diffraction patterns of as formed Gd1.96Eu0.04O3 showed monoclinic phase, however with the addition of yttria it transforms from monoclinic to pure cubic phase. The porous nature increases with increase of yttria content. The particle size was estimated from Scherrer's and W-H plots which was found to be in the range 30-40 nm. These results were in well agreement with transmission electron microscopy studies. The optical band gap energies estimated were found to be in the range 5.32-5.49 eV. PL emission was recorded under 305 nm excitation show an intense emission peak at 611 nm along with other emission peaks at 582, 641 nm. These emission peaks were attributed to the transition of (5)D0→(7)FJ (J = 0, 1, 2, 3) of Eu(3+) ions. It was observed that PL intensity increases with increase of Y content up to x = 0.98 and thereafter intensity decreases. CIE color co-ordinates indicates that at x = 1.47 an intense red bright color can be achieved, which could find a promising application in flat panel displays. The cubic and monoclinic phases show different thermoluminescence glow peak values measured under identical conditions. The response of the cubic phase to the applied dose showed good linearity, negligible fading, and simple glow curve structure than monoclinic phase indicating that suitability of this phosphor in dosimetric applications. PMID:24699292

  5. Optical spectra and crystal field analysis of Dy3+ in Cs2NaDyCl6 and Cs2NaYCl6: Dy3+(5 mol %)

    NASA Astrophysics Data System (ADS)

    Foster, David R.; Richardson, F. S.

    1985-02-01

    Optical absorption and emission measurements are reported for the Cs2NaDyCl6 and Cs2NaYCl6: Dy3+(5 mol %) systems under variable-temperature (10-298 K) conditions. For both systems, the data are compatible with the retention of octahedral (Oh) site symmetry at the Dy3+ ions over the entire 298 to 10 K temperature range. The only differentiation between the systems is the much greater quantum efficiency of 4F9/2 emission in the doped system vs that in the neat system. Forty-five crystal-field levels spanning 18 multiplets of the Dy3+ 4f9 electronic configuration are located and assigned, and an additional 12 crystal-field levels associated with six other multiplet manifolds are located, but left unassigned. These energy level results are analyzed on the basis of a nine-parameter 4f-electron Hamiltonian operating within a complete Russell-Saunders (SLJ) basis set for the 4f9 configuration of Dy3+. The most intense electric-dipole vibronic lines observed in the optical spectra are assigned to one-phonon vibronic transitions associated with the three odd-parity ``moiety'' modes of the DyCl3-6 octahedral clusters: ν3(t1u), ν4(t1u), and ν6(t2u). Intensity calculations are reported for both the no-phonon magnetic-dipole (origin) transitions and the one-phonon (ν3, ν4, and ν6) electric-dipole vibronic transitions.

  6. 40 CFR 10.4 - Evidence to be submitted.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... such expenses. (7) If damages for pain and suffering prior to death are claimed, a physician's detailed statement specifying the injuries suffered, duration of pain and suffering, any drugs administered for pain... pain and suffering, the claimant may be required to submit the following evidence or information: (1)...

  7. 40 CFR 10.4 - Evidence to be submitted.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... such expenses. (7) If damages for pain and suffering prior to death are claimed, a physician's detailed statement specifying the injuries suffered, duration of pain and suffering, any drugs administered for pain... pain and suffering, the claimant may be required to submit the following evidence or information: (1)...

  8. 40 CFR 10.4 - Evidence to be submitted.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... authenticated death certificate or other competent evidence showing cause of death, date of death, and age of... such expenses. (7) If damages for pain and suffering prior to death are claimed, a physician's detailed statement specifying the injuries suffered, duration of pain and suffering, any drugs administered for...

  9. 17 CFR 10.4 - Business address; hours.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... in other matters within the scope of this part. Legal holidays include New Year's Day, Washington's Birthday, Memorial Day, Independence Day, Labor Day, Columbus Day, Veterans Day, Thanksgiving Day... Centre, 1155 21st Street NW., Washington, DC 20581. It is open each day, except Saturdays, Sundays...

  10. 40 CFR 10.4 - Evidence to be submitted.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... such expenses. (7) If damages for pain and suffering prior to death are claimed, a physician's detailed statement specifying the injuries suffered, duration of pain and suffering, any drugs administered for pain... pain and suffering, the claimant may be required to submit the following evidence or information: (1)...

  11. Transients and cooperative action of β-carotene, vitamin E and C in biological systems in vitro under irradiation

    NASA Astrophysics Data System (ADS)

    Getoff, Nikola; Platzer, Isabel; Winkelbauer, Cornelia

    1999-08-01

    Using N •3 species as specific electron acceptor a defined ascorbate radical: AH •↔A •-+H + (λ max=360 nm, ɛ=3400 dm 3 mol -1 cm -1) is observed. The attack of DMSO •+ on vit.E results in a vit.E • radical ( k=1×10 9 dm 3 mol -1 s -1; λ max=425 nm, ɛ=2400 dm 3 mol -1 cm -1; 2 k=4.7×10 8 dm 3 mol -1 s -1). Vit.E-acetate leads to the formation of a radical cation (vit.E-ac •+). β-carotene reacts also with DMSO •+ forming a radical cation, β-car •+ ( k=1.75×10 8 dm 3 mol -1 s -1; λ max=942 nm, ɛ=14 600 dm 3 mol -1 cm -1), which probably leads to the formation of a dimer radical cation, (β-car) •+2 ( k=2.5×10 7 dm 3 mol -1 s -1). Using E.coli bacteria (AB1157) as a model system in vitro it was found that all three vitamins are rather efficient radiation protecting agents. They can also increase the activity of cytostatica, e.g., mitomycin C (MMC), by electron transfer process. The mixture of vit.E-ac and β-car acts contradictory, but adding vit.C to it a strong cooperative enhancement of the MMC activity is observed once again. A relationship between the pulse radiolysis and the radiation biological data is found and discussed. A possible explanation of the previously reported trials concerning the role of vit.E and β-car on the increased occurence of lung and other types of cancer in smokers and drinkers is presented.

  12. Diagnostic moléculaire d'helicobacter pylori par PCR chez les patients en consultation gastroentérologique au Centre Médical Saint Camille de Ouagadougou

    PubMed Central

    Werme, Karidia; Bisseye, Cyrille; Ouedraogo, Issiaka; Yonli, Albert Théophane; Ouermi, Djénèba; Djigma, Florencia; Moret, Rémy; Gnoula, Charlemagne; Nikiema, Jean-Baptiste; Simpore, Jacques

    2015-01-01

    Introduction L'infection par Helicobacter pylori constitue un problème de santé publique notamment dans les pays en développement. Elle entraine une gastrite pouvant évoluer vers des formes sévères d'ulcération et de transformation maligne. La présenté étude avait pour objectif de diagnostiquer H. pylori par des techniques sérologique et moléculaire au Burkina Faso. Méthodes L’étude prospective a été conduite de mars à juin 2012 sur 70 patients venus en consultation dans le service de gastroentérologie au Centre Médical Saint Camille. Le diagnostic de H. pylori a été réalisé par le test ELISA Immunocomb (ORGENICS Ltd, Yavne, Israël) et la PCR sur des biopsies gastriques prélevées sur les patients. Résultats Les pathologies gastroduodénales étaient plus fréquentes chez les patients de plus de 45 ans. Les prévalences de H. pylori étaient respectivement de 88,57% et de 91,43% par sérologie Immunocomb et par PCR. La différence entre les deux techniques n’était pas significative (P = 0,573). La performance de la PCR a été comparée à celle de la technique Immunocomb. Les résultats montrent une sensibilité et une spécificité de 92,2% et 50,0% pour la technique Immunocomb. Conclusion Le diagnostic de H. pylori par PCR est plus spécifique que le test sérologique Immunocomb et devrait être introduit dans le diagnostic de routine de cette bactérie pathogène au Burkina Faso. PMID:26327960

  13. Coordination of bis­(pyrazol-1-yl)amine to palladium(II): influence of the co-ligands and counter-ions on the mol­ecular and crystal structures1

    PubMed Central

    Mendoza, María de los Angeles; Bernès, Sylvain; Mendoza-Díaz, Guillermo

    2015-01-01

    The structures of a series of complexes with general formula n[Pd(pza)X]Y·mH2O (n = 1, 2; X = Cl, Br, I, N3, NCS; Y = NO3, I, N3, [Pd(SCN)4]; m = 0, 0.5, 1) have been determined, where pza is the tridentate ligand bis­[2-(3,5-di­methyl­pyrazol-1-yl)eth­yl]amine, C14H23N5. In all complexes, {bis­[2-(3,5-di­methyl­pyrazol-1-yl-κN 2)eth­yl]amine-κN}chlorido­palladium nitrate, [Pd(pza)Cl]NO3, (1), {bis­[2-(3,5-di­methyl­pyrazol-1-yl-κN 2)eth­yl]amine-κN}bromido­palladium nitrate, [Pd(pza)Br]NO3, (2), {bis­[2-(3,5-di­methyl­pyrazol-1-yl-κN 2)eth­yl]amine-κN}iodido­palladium iodide hemihydrate, [Pd(pza)I]I·0.5H2O, (3), azido{bis­[2-(3,5-di­methyl­pyrazol-1-yl-κN 2)eth­yl]amine-κN}palladium azide monohydrate, [Pd(pza)N3]N3·H2O, (4), and bis­[{bis­[2-(3,5-di­methyl­pyrazol-1-yl-κN 2)eth­yl]amine-κN}(thio­cyanato-κN)palladium] tetra­kis­(thio­cyanato-κS)palladate, [Pd(pza)NCS]2[Pd(SCN)4], (5), the [Pd(pza)X]+ complex cation displays a square-planar coordination geometry, and the pza ligand is twisted, approximating twofold rotation symmetry. Although the pza ligand is found with the same conformation along the series, the dihedral angle between pyrazole rings depends on the co-ligand X. This angle span the range 79.0 (3)–88.6 (1)° for the studied complexes. In (3), two complex cations, two I− anions and one water mol­ecule of crystallization are present in the asymmetric unit. In (5), the central amine group of pza is disordered over two positions [occupancy ratio 0.770 (18):0.230 (18)]. The complex [Pd(SCN)4]2− anion of this compound exhibits inversion symmetry and shows the Pd2+ transition metal cation likewise in a square-planar coordination environment. Compound (5) is also a rare occurrence of a non-polymeric compound in which the pseudohalide ligand NCS− behaves both as thio­cyanate and iso­thio­cyanate, i.e. is coordinating either through the N atom (in the cation) or the S atom (in the anion). PMID

  14. The advantage of spectrophotometric measurement for size-selective complexing of Cu(II) with O2N2-azacrown ligands

    NASA Astrophysics Data System (ADS)

    Ghanbari, Bahram; Gholamnezhad, Parisa

    2015-03-01

    A comparative investigation of the interaction of Cu(II) with a series of 15- to 19-membered mixed-donor dibenzo-substituted macrocyclic ligands, each incorporating an O2N2-donor set, has been carried out using UV-Visible studies in methanol. Although a ring size effect has been reported for a related series of Ni(II) complexes, no such metal ion discrimination has been reported for Cu(II) in terms of its binding constants with 14- to 17-membered macrocycles. Employing Job's method of continuous variation established 1:1 stoichiometry for the interaction between Cu(II) and 1-5. From UV-Visible studies applying the Benesi-Hildebrand equation, the binding constants (K) of Cu(II) with 1-5 were determined to be Cu(II)/1 = 3330 (±321) dm3 mol-1, Cu(II)/2 = 33,700 (±71) dm3 mol-1, Cu(II)/3 = 7260 (±151) dm3 mol-1, Cu(II)/4 = 57,000 (±257) dm3 mol-1 and Cu(II)/5 = 13,900 (±398) dm3 mol-1 in methanol at 25 °C, respectively. The calculated binding constants showed a saw-tooth pattern in which 4 (18-membered ring) gives the highest K value for these complexes. The thermodynamic parameters (ΔG, ΔH, and TΔS) of the respective complexes have also been determined.

  15. Raman Analysis of Dilute Aqueous Samples by Localized Evaporation of Submicroliter Droplets on the Tips of Superhydrophobic Copper Wires.

    PubMed

    Cheung, Melody; Lee, Wendy W Y; McCracken, John N; Larmour, Iain A; Brennan, Steven; Bell, Steven E J

    2016-04-19

    Raman analysis of dilute aqueous solutions is normally prevented by their low signal levels. A very general method to increase the concentration to detectable levels is to evaporate droplets of the sample to dryness, creating solid deposits which are then Raman probed. Here, superhydrophobic (SHP) wires with hydrophilic tips have been used as supports for drying droplets, which have the advantage that the residue is automatically deposited at the tip. The SHP wires were readily prepared in minutes using electroless galvanic deposition of Ag onto copper wires followed by modification with a polyfluorothiol (3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,10-heptadecafluoro-1-decanethiol, HDFT). Cutting the coated wires with a scalpel revealed hydrophilic tips which could support droplets whose maximum size was determined by the wire diameter. Typically, 230 μm wires were used to support 0.6 μL droplets. Evaporation of dilute melamine droplets gave solid deposits which could be observed by scanning electron microscopy (SEM) and Raman spectroscopy. The limit of detection for melamine using a two stage evaporation procedure was 1 × 10(-6) mol dm(-3). The physical appearance of dried droplets of sucrose and glucose showed that the samples retained significant amounts of water, even under high vacuum. Nonetheless, the Raman detection limits of sucrose and glucose were 5 × 10(-4) and 2.5 × 10(-3) mol dm(-3), respectively, which is similar to the sensitivity reported for surface-enhanced Raman spectroscopy (SERS) detection of glucose. It was also possible to quantify the two sugars in mixtures at concentrations which were similar to those found in human blood through multivariate analysis. PMID:27031750

  16. The effect of coadsorbent and solvent on the photovoltaic performance of 2,9,16,23-Tetrakis(7-coumarinoxy-4-methyl)-phthalocyaninatocopper-sensitized solar cells

    NASA Astrophysics Data System (ADS)

    Zhang, Fei; Wang, Shi-Rong; Li, Xiang-Gao; Xiao, Yin; Guo, Jun-Jie

    2016-03-01

    The synthesis, characterization and thermal properties of CuPc-Cou were reported and the effects of chenodeoxycholic acid (CHENO) as a coadsorbent and the solvent on the solar cell's performance were investigated. The ground state absorbance of CuPc-Cou showed the molar extinction coefficients as high as 2.90 × 104 dm3 mol-1 cm-1 in DMF and 2.74 × 104 dm3 mol-1 cm-1 in CH2Cl2. The thermal stability studies indicated that CuPc-Cou was stable up to 370 °C. Furthermore, HOMO and LUMO energies made it clear that CuPc-Cou can be used as a sensitizer for DSSC. Adding CHENO onto TiO2 nanoparticles not only reduced the adsorption of phthalocyanine sensitizers but also prevented the aggregation behavior, leading to different photovoltaic performance. The open circuit voltage of the solar cells with CHENO coadsorbent increased due to the enhanced electron lifetime in TiO2 nanoparticles coupled with the band edge shift of TiO2 to negative potentials. The optimal dye adsorption condition of the TiO2 electrode was found to be 3 × 10-4 M CuPc-Cou solution containing 6.0 mM CHENO in dichloromethane, which could contribute to improve the PCE by 69% as compared to the solar cell fabricated with TiO2 electrode sensitized by the CuPc-Cou in absence of CHENO and the optimal condition in DMF. It indicated that CuPc-Cou in DMF was easy to aggregate than in CH2Cl2 for the solvent effect.

  17. An ultrasensitive electrochemical genosensor for Brucella based on palladium nanoparticles.

    PubMed

    Rahi, A; Sattarahmady, N; Heli, H

    2016-10-01

    Palladium nanoparticles were potentiostatically electrodeposited on a gold surface at a highly negative potential. The nanostructure, as a transducer, was utilized to immobilize a Brucella-specific probe and the process of immobilization and hybridization was detected by electrochemical methods. The proposed method for detection of the complementary sequence and a non-complementary sequence was applied. The fabricated genosensor was evaluated for the assay of the bacteria in the cultured and human samples with and without PCR. The genosensor could detect the complementary sequence with a sensitivity of 0.02 μA dm(3mol(-1), a linear concentration range of 1.0 × 10(-12) to 1.0 × 10(-19) mol dm(-3), and a detection limit of 2.7 × 10(-20) mol dm(-3). PMID:27423961

  18. Diffusion coefficients of sodium fluoride in aqueous solutions at 298.15 k and 310.15 k.

    PubMed

    Ribeiro, Ana C F; Lobo, Victor M M; Sobral, Abilio J F N; Soares, Helder T F C; Esteso, Ana R J; Esteso, Miguel A

    2010-06-01

    Mutual diffusion coefficients (interdiffusion coefficients) have been measured for sodium fluoride in water at 298.15 K and 310.15 K at concentrations between 0.003 mol dm-3 and 0.05 mol dm-3. The diffusion coefficients were measured using a conductimetric cell. The experimental mutual diffusion coefficients are discussed on the basis of the Onsager-Fuoss model. The limiting molar conductivity of the fluoride ion in these solutions at 310.15 K has been estimated using these results. PMID:24061738

  19. Reaction of diethyl maleate and diethyl fumarate with hydrated electrons and hydroxyl radicals

    NASA Astrophysics Data System (ADS)

    Bíró, Á.; Wojnárovits, L.

    1996-03-01

    In dilute aqueous solution diethyl maleate (DEM) and diethyl fumarate (DEF) scavenge hydrated electrons with a rate constant of 2.2·10 10 mol -1 dm 3 s -1. DEM - reversibly protonates with pK a = 5.2. The pK a of DEF - is below 4. The electron adducts decay in second order reactions. The OH radicals add to the double bonds with 5.9·10 9 mol -1 dm 3 s -1. In the reaction α-carboxyalkyl radicals are produced. In disproportionation of radicals oxalacetic acid ethylester forms that in alkaline solution leads to strong permanent absorbency in the UV.

  20. Voltammetric behavior of methaqualone and its determination by single-sweep oscillopolarography.

    PubMed

    Zhang, Lijuan; Zhang, Shaofeng; Wan, Youzhi

    2003-04-10

    A well derivative reduction wave of methaqualone (MTQ) was obtained in 0.033 mol dm(-3) B-R (pH 3.76) buffer solution by single-sweep oscillopolarography. The peak potential is -1.36 V (vs. saturated calomel reference electrode, SCE). The peak current is proportional to the concentration of methaqualone over the range of 7.0 x 10(-8)-9.0 x 10(-6) mol dm(-3). The method has been successfully applied to the determination of methaqualone in tablets. The wave is believed to result from irreversible adsorption through studies of its electrochemical behavior and reaction mechanism. PMID:18968991

  1. Indirect spectrophotometric determination of small amounts of selenium(IV) and arsenic(V) by simple extraction using flotation columns.

    PubMed

    Mostafa, G A; Ghazy, S E

    2001-10-01

    A simple, rapid and selective procedure for the indirect spectrophotometric determination of Se(IV) and As(V) has been developed. It is based on the reduction of Se(IV) to Se(0) and As(V) to As(III) with hydroiodic acid (KI + HCl). The liberated iodine, equivalent to each analyte, is quantitatively extracted with oleic acid (HOL) surfactant. The iodine-HOL system exhibits its maximum absorbance at 435 nm. The different analytical parameters affecting the extraction and determination processes have been examined. The calibration graphs were found to be linear over the ranges 5-120 and 0.25-20 ppm of Se(IV) and As(V), with lower detection limits of 2.5 and 0.15 ppm and molar absorptivities of 1 x 10(4) and 0.5 x 10(4) dm3 mol(-1) cm(-1), respectively. Sandell's sensitivity was calculated to be 0.0078 and 0.0149 microg/cm2 in the same order. The relative standard deviation for five replicate analyses of 40 ppm Se(IV) and 4 ppm As(V) were 1.0 and 0.9%, respectively. The proposed procedure in the presence of EDTA as a masking agent for foreign ions has been successfully applied to the determination of Se(IV) in a reference sample and As(V) in copper metal, in addition to their determination in spiked and polluted water samples. PMID:11990594

  2. A spectrophotometric study of the formation and deprotonation of thioarsenite species in aqueous solution at 22 °C

    NASA Astrophysics Data System (ADS)

    Zakaznova-Herzog, Valentina P.; Seward, Terry M.

    2012-04-01

    The ionization constants of thioarsenous acid have been determined at 22 °C by measuring the ultraviolet and visible spectra of thioarsenite species in dilute, aqueous sulfide solutions having S/As = 4.18, As = 1.1 × 10-4 mol/dm3 and pH ≈ 6-10.4. No oxidized species such as arsenate, thioarsenate or polysulfides were detected in the experimental solutions. The equilibrium constants for the thioarsenous acid ionization reactions were obtained from a principal component analysis treatment of the spectra and are as follows: H3AsS3=H+H2AsS3- for which pKa1=3.77 (±0.15) H2-AsS32-=H+H2AsS3- for which pKa2=6.53 (±0.08) HAsS32-=H+AsS33- for which pKa3=9.29 (±0.08) The pKa’s for the oxythioarsenous ionization reactions have also been estimated by analogy with those for the end member arsenous and thioarsenous acids. The data emphasize the important role of the simple arsenic(III) thioanions in defining the transport and redox chemistry of arsenic in sulfide-containing natural waters.

  3. Cytogenetic damage in shallot ( Allium cepa) root meristems induced by oil industry "high-density brines".

    PubMed

    Vidaković-Cifrek, Z; Pavlica, M; Regula, I; Papes, D

    2002-10-01

    Saturated water solutions of calcium chloride, calcium bromide (densities 1.30 kg x dm(-3) and 1.61 kg x dm(-3), respectively) and their 1:1 mixture have been commonly used as oil industry "high-density brines." In our experiment they were added to tap water in amounts appropriate to achieve concentrations of 0.025, 0.05, 0.075, and 0.1 mol x dm(-3) to study their cytotoxic effect on the root tip cells of shallot ( Allium cepa L. var. ascalonicum). All tested solutions in concentrations of 0.075 and 0.1 mol x dm(-3) caused significant inhibition of shallot root growth. CaBr (2) showed this effect in concentration 0.05 mol x dm(-3). The investigated solutions in all concentrations applied decreased mitotic activity in root tip cells. The most of mitotic abnormalities were the consequence of spindle failure and chromosome stickiness. Furthermore, the cell microtubules were investigated by indirect immunofluorescence to confirm that most abnormalities observed were the consequence of spindle failure. The present study, as well as previously done Lemna tests and Chlorella tests showed that investigated samples have certain effects on plants, so constant control of their presence in the environment is needed. PMID:12202923

  4. Crystal structure of cis-bis­{4-phenyl-1-[(3R)-1,7,7-tri­methyl-2-oxobi­cyclo­[2.2.1]heptan-3-ylidene]thio­semicarbazidato-κ3 O,N 1,S}cadmium(II) with an unknown solvent mol­ecule

    PubMed Central

    Nogueira, Vanessa Senna; Bresolin, Leandro; Näther, Christian; Jess, Inke; de Oliveira, Adriano Bof

    2015-01-01

    The reaction between the racemic mixture of the camphor-4-phenyl­thio­semicarbazone derivative and cadmium acetate dihydrate yielded the title compound, [Cd(C17H20N3OS)2]. The CdII ion is six-coordinated in a distorted octa­hedral environment by two deprotonated thio­semicarbazone ligands acting as an O,N,S-donor in a tridentate chelating mode, forming five-membered chelate rings. In the crystal, the mol­ecules are connected via pairs of N—H⋯S and C—H⋯S inter­actions, building centrosymmetric dimers. One of the ligands is disordered in the campher unit over two sets of sites with site-occupancy factors of 0.7 and 0.3. The structure contains additional solvent mol­ecules, which are disordered and for which no reasonable split model was found. Therefore, the data were corrected for disordered solvent using the SQUEEZE routine [Spek (2015 ▸). Acta Cryst. C71, 9–18] in PLATON. Since the disordered solvents were removed by data processing, and the number of solvent entities was a suggestion only, they were not considered in the chemical formula and subsequent chemical or crystal information. PMID:26870441

  5. Crystal structure of cis-bis-{4-phenyl-1-[(3R)-1,7,7-tri-methyl-2-oxobi-cyclo-[2.2.1]heptan-3-ylidene]thio-semicarbazidato-κ(3) O,N (1),S}cadmium(II) with an unknown solvent mol-ecule.

    PubMed

    Nogueira, Vanessa Senna; Bresolin, Leandro; Näther, Christian; Jess, Inke; de Oliveira, Adriano Bof

    2015-12-01

    The reaction between the racemic mixture of the camphor-4-phenyl-thio-semicarbazone derivative and cadmium acetate dihydrate yielded the title compound, [Cd(C17H20N3OS)2]. The Cd(II) ion is six-coordinated in a distorted octa-hedral environment by two deprotonated thio-semicarbazone ligands acting as an O,N,S-donor in a tridentate chelating mode, forming five-membered chelate rings. In the crystal, the mol-ecules are connected via pairs of N-H⋯S and C-H⋯S inter-actions, building centrosymmetric dimers. One of the ligands is disordered in the campher unit over two sets of sites with site-occupancy factors of 0.7 and 0.3. The structure contains additional solvent mol-ecules, which are disordered and for which no reasonable split model was found. Therefore, the data were corrected for disordered solvent using the SQUEEZE routine [Spek (2015 ▸). Acta Cryst. C71, 9-18] in PLATON. Since the disordered solvents were removed by data processing, and the number of solvent entities was a suggestion only, they were not considered in the chemical formula and subsequent chemical or crystal information. PMID:26870441

  6. High Calcium (~80mol%) Late Stage Carbonate in ALH84001

    NASA Astrophysics Data System (ADS)

    Gildea, K. J.; Holland, G.; Lyon, I. C.; Chatzitheodoridis, E.; Burgess, R.

    2006-03-01

    Brief petrological, chemical and textural description of previously undescribed high Ca late stage carbonate in Martian meteorite ALH84001. This carbonate surrounds Mg rich carbonates and rosette fragments.

  7. Mol-Gastronomie Granulare Fleischgerichte und molekulares Kleben

    NASA Astrophysics Data System (ADS)

    Vilgis, Thomas A.

    2005-09-01

    Buletten, Fleischküchle oder Kebabs, Köstlichkeiten aus gehacktem Fleisch bestimmter Körnung, finden sich in allen Kulturen. Physikalisch ein großes Problem, denn zu Tisch dürfen diese Gebilde nicht auseinander brechen und zerfallen. Für ausreichend Bindung und Klebung muss also gesorgt werden.

  8. 14a-Hy­droxy-12-methyl-10-(4-methyl­phen­yl)-8,9,9a,10,12,13,14,14a-octa­hydro-10a,14-methano-5H-indeno­[2′,1′:4,5]azepino[3,4-b]pyrrolizine-5,15(7H,11H)-dione

    PubMed Central

    Nagalakshmi, R. A.; Suresh, J.; Malathi, K.; Kumar, R. Ranjith; Lakshman, P. L. Nilantha

    2013-01-01

    In the title compound, C27H28N2O3, each of the pyrrolidine rings adopts a twisted conformation, as does the cyclo­pentane ring. The indane ring has an r.m.s deviation of 0.0693 Å. The dihedral angle between the mean plane of the pyrrolizine ring and indane system is 82.58 (1)°. The piperidine ring has the methyl substituent in an equatorial position and adopts a twisted chair conformation. The mol­ecular structure is stabilized by a weak intra­molecular O—H⋯N inter­action. PMID:24098257

  9. A 1H NMR titration study on the binding constants for D- and L-tryptophan inclusion complexes with 6-O-α-D-glucosyl-β-cyclodextrin. Formation of 1:1 and 2:1 (host:guest) complexes

    NASA Astrophysics Data System (ADS)

    Akita, Tomoki; Matsui, Yoshihisa; Yamamoto, Tatsuyuki

    2014-02-01

    A 1H NMR titration study revealed that 6-O-α-D-glucosyl-β-cyclodextrin (G1-β-CD) forms 1:1 and 2:1 (host:guest) inclusion complexes with D- and L-tryptophan in alkaline D2O solutions (pD 11.0). The binding constants (K1's) for the 1:1 complexes of D-isomer at 298 K (59 mol-1 dm3) were virtually equal to that of L-isomer (54 mol-1 dm3). On the other hand, the K2 values for 2:1 complexes of D-isomer (42 mol-1 dm3) were larger than that of L-counterpart (12 mol-1 dm3). These facts suggest that the first CD molecule includes the indole ring moiety of tryptophan, followed by inclusion with the second CD molecule in the vicinity of chiral center, α-carbon of the guest, to result in the difference in K2's for two enantiomers. Two-dimensional NMR measurement (Rotating-frame nuclear Overhauser Effect SpectroscopY, ROESY) supported this interpretation.

  10. Rate coefficients of hydroxyl radical reactions with pesticide molecules and related compounds: A review

    NASA Astrophysics Data System (ADS)

    Wojnárovits, László; Takács, Erzsébet

    2014-03-01

    Rate coefficients published in the literature on hydroxyl radical reactions with pesticides and related compounds are discussed together with the experimental methods and the basic reaction mechanisms. Recommendations are made for the most probable values. Most of the molecules whose rate coefficients are discussed have aromatic ring: their rate coefficients are in the range of 2×109-1×1010 mol-1 dm3 s-1. The rate coefficients show some variation with the electron withdrawing-donating nature of the substituent on the ring. The rate coefficients for triazine pesticides (simazine, atrazine, prometon) are all around 2.5×109 mol-1 dm3 s-1. The values do not show variation with the substituent on the s-triazine ring. The rate coefficients for the non-aromatic molecules which have C=C double bonds or several C-H bonds may also be above 1×109 mol-1 dm3 s-1. However, the values for molecules without C=C double bonds or several C-H bonds are in the 1×107-1×109 mol-1 dm3 s-1 range.

  11. Absorption spectrophotometric, fluorescence and quantum chemical investigations on non-covalent interaction between PC₇₀BM and designed diporphyrin in solution.

    PubMed

    Ray, Anamika; Bauri, Ajoy; Bhattacharya, Sumanta

    2015-01-01

    Present work reports the photophysical insights on supramolecular interaction of a C₇₀ derivative, namely, [6,6]-phenyl C₇₁ butyric acid methyl ester (PC₇₀BM), with two designed diporphyrin molecules having dithiophene (1) and carbazole (2) spacer in toluene and benzonitrile. Both absorption spectrophotometric and steady state fluorescence investigations reveal efficient complexation of PC₇₀BM with 1 and 2 in both toluene and benzonitrile. The magnitude of average value of binding constant, viz., Kav, for the complexes of PC₇₀BM with 1 and 2 in toluene (benzonitrile) are estimated to be 2.185 × 10(3)dm(3)mol(-1) (3.215 × 10(3)dm(3)mol(-1)) and 10.180 × 10(3)dm(3)mol(-1) (25.405 × 10(3)dm(3)mol(-1)), respectively. Selectivity in binding for the complexation process of PC₇₀BM with 1 and 2 is estimated to be ∼4.6 and ∼7.90 as observed in toluene and benzonitrile, respectively. The complexation between PC₇₀BM and diporphyrin is well accounted by a theoretical model which takes into account the electronic subsystems of both acceptor and donor. Ab initio calculations in vacuo establish that size selective orientation pattern of PC₇₀BM towards the cavity of diporphyrin dictates the magnitude of binding and electronic structure of the PC₇₀BM/diporphyrin complexes. PMID:25138385

  12. Poly-Alizarin red S/multiwalled carbon nanotube modified glassy carbon electrode for the boost up of electrocatalytic activity towards the investigation of dopamine and simultaneous resolution in the presence of 5-HT: A voltammetric study.

    PubMed

    Reddaiah, K; Madhusudana Reddy, T; Venkata Ramana, D K; Subba Rao, Y

    2016-05-01

    Poly-Alizarin red S/multiwalled carbon nanotube film on the surface of glassy carbon electrode (poly-AzrS/MWCNT/GCE) was synthesized by electrochemical process and was used for the sensitive and selective determination of dopamine (DA) by employing voltammetric techniques. The electrocatalytic response of the modified electrode was found to exhibit admirable activity. The simultaneous determination of dopamine in the presence of serotonin (5-HT) was found to exhibit very good response at poly-AzrS/MWCNTs/GCE. The effect of pH, scan rate, accumulation time and concentration of dopamine was studied at the developed poly-AzrS/MWCNTs/GCE. The poly-AzrS/MWCNTs/GCE exhibited an efficient electron mediating behavior together with well resolved peaks for dopamine, in 0.1mol/dm(3) phosphate buffer (PBS) solution of pH7.0. The limit of detection (LOD) and limit of quantification (LOQ) were found to be as 1.89×10(-7)mol/dm(3) and 6.312×10(-7)mol/dm(3) respectively with a dynamic range from 1×10(-6) to 1.8×10(-5)mol/dm(3). The interfacial electron transfer behavior of DA was studied by electrochemical impedance spectroscopy (EIS); the studies showed that the charge transfer rate was enhanced at poly-AzrS/MWCNTs/GCE when compared with bare GCE and poly-AzrS/GCE. PMID:26952453

  13. Alkali doped poly (2,5-benzimidazole) membrane for alkaline water electrolysis: Characterization and performance

    NASA Astrophysics Data System (ADS)

    Diaz, Liliana A.; Hnát, Jaromír; Heredia, Nayra; Bruno, Mariano M.; Viva, Federico A.; Paidar, Martin; Corti, Horacio R.; Bouzek, Karel; Abuin, Graciela C.

    2016-04-01

    The properties and performance of linear and cross-linked KOH doped ABPBI membranes as electrolyte/separator for zero gap alkaline water electrolysis cells are evaluated and compared with a commercial Zirfon® diaphragm. Stability in alkaline environment, swelling, thermal properties, water sorption, KOH uptake and conductivity of linear (L-ABPBI) and cross-linked (C-ABPBI) membranes doped with different concentrations of KOH are analyzed. Linear membranes show stability up to 3.0 mol·dm-3 KOH doping, while cross-linked membranes are stable up to 4.2 mol·dm-3 KOH doping. Both kinds of membranes exhibit good thermal stability and reasonable specific ionic conductivity at 22 °C in the range between 7 and 25 mS·cm-1, being slightly higher the conductivity of C-ABPBI membranes than that of L-ABPBI ones. In short-term electrolysis tests both L-ABPBI and C-ABPBI membranes show better performance than Zirfon diaphragm in the range from 50 to 70 °C. A current density of 335 mA·cm-2 at a cell voltage of 2.0 V is attained with C-ABPBI membranes doped in 3 mol·dm-3 KOH at 70 °C, a performance comparable with that of commercial units operating at temperatures ca. 80 °C and 30 wt% KOH (6.7 mol·dm-3) as electrolyte.

  14. Decay Mechanism of NO3(•) Radical in Highly Concentrated Nitrate and Nitric Acidic Solutions in the Absence and Presence of Hydrazine.

    PubMed

    Garaix, Guillaume; Horne, Gregory P; Venault, Laurent; Moisy, Philippe; Pimblott, Simon M; Marignier, Jean Louis; Mostafavi, Mehran

    2016-06-01

    The decay mechanism of NO3(•) has been determined through a combination of experiment and calculation for 7 mol dm(-3) solutions of deaerated aqueous LiNO3 and HNO3, in the absence and presence of hydrazine (N2H4, N2H5(+), and N2H6(2+)). In the absence of hydrazine, the predominant NO3(•) decay pathways are strongly dependent upon the pH of the solution. For neat, neutral pH LiNO3 solutions (7 mol dm(-3)), NO3(•) produced by the pulse is fully consumed within 160 μs by OH(•) (37%), H2O (29%), NO2(-) (17%), and NO2 (17%). For acidic HNO3 solutions (7 mol dm(-3)), radiolytically produced NO3(•) is predominantly consumed within 1 ms by HNO2 (15%) and NO2 (80%). Intervening formulations exhibit the mechanistic transition from neat LiNO3 to neat HNO3. In highly acidic nitric acid solution, hydrazine exists mainly as N2H5(+) and N2H6(2+), both of which rapidly consume NO3(•) in addition to other decay mechanisms, with rate constants of 2.9 (±0.9) × 10(7) and 1.3 (±0.3) × 10(6) dm(3) mol(-1) s(-1), respectively. PMID:27171587

  15. Cysteine as a green corrosion inhibitor for Cu37Zn brass in neutral and weakly alkaline sulphate solutions.

    PubMed

    Radovanović, Milan B; Petrović, Marija B; Simonović, Ana T; Milić, Snežana M; Antonijević, Milan M

    2013-07-01

    The aim of this study was to investigate electrochemical properties of brass in neutral and weakly alkaline solutions in the presence of cysteine as a nontoxic and ecological corrosion inhibitor. Potentiodynamic measurements, open circuit potential measurements, as well as chronoamperometric measurements were the methods used during investigation of the inhibitory effect of cysteine on the corrosion behaviour of brass. Potentiodynamic measurements showed that cysteine behaves as a mixed-type inhibitor in the investigated media. Based on polarization curves for brass in a weakly alkaline solution of sodium sulphate at varying cysteine concentrations, an interaction occurs between Cu(+) ions and the inhibitor, resulting in the formation of a protective complex on the electrode surface. The results of chronoamperometric measurements confirm the results obtained by potentiodynamic measurements. Optical microphotography of the brass surface also confirms the formation of a protective film in the presence of a 1 × 10(-4) mol/dm(3) cysteine. Adsorption of cysteine on the brass surface proceeds according to the Langmuir adsorption isotherm. PMID:22836675

  16. Highly sensitive extractive spectrophotometric determination of palladium(II) in synthetic mixtures and hydrogenation catalysts using benzildithiosemicarbazone.

    PubMed

    Reddy, B Krishna; Reddy, K Janardhan; Kumar, J Rajesh; Kumar, A Kiran; Reddy, A Varada

    2004-06-01

    A simple and highly sensitive method was developed for the extractive-spectrophotometric determination of palladium with benzilidithiosemicarbazone. The metal ion formed a reddish brown complex with benzildithiosemicarbazone in a potassium chloride-hydrochloric acid buffer of pH 2.5, which was easily extractable into methyl isobutyl ketone. The 1:1 complex showed the maximum absorbance at 395 nm with a Beer's law range of 0.25-3.5 ppm. The molar absorptivity and Sandell's sensitivity were found to be 3.018 x 10(4) dm3 mol(-1) cm(-1) and 0.0035 microg cm(-2), respectively. The correlation coefficient of the Pd(II)-BDTSC complex was 0.998, which indicated an excellent linearity between the two variables. The repeatability of the method was checked by finding the relative standard deviation (RSD) (n = 10), which was 0.46%. The instability constant of the complex calculated from Edmond and Birnbaum's method was 2.41 x 10(-5), that of Asmus' method is 2.53 x 10(-5) at room temperature. The interfering effects of various cations and anions were studied. The proposed method was successfully applied to the determination of palladium(II) in synthetic mixtures and hydrogenation catalysts. The validity of the method was tested by comparing the results with those obtained using an atomic absorption spectrophotometer. PMID:15228112

  17. Oxalate molecule as the trap for gamma-irradiation energy in the amorphous aluminosilicate Al2(OH)6H4SiO4

    SciTech Connect

    Nothig-Laslo, V.; Horvath, L.; Bilinski, H. )

    1990-07-01

    Paramagnetic species which were the products of gamma irradiation at 77 K and at room temperature were studied by ESR spectroscopy in the amorphous aluminosilicate, Al2(OH)6H4SiO4, prepared in the presence and in the absence of oxalate ion. The aluminosilicate precipitated from the solution containing the oxalate ion in 10(-4) mol dm-3 concentration contained the oxalate only in trace amounts. When gamma-irradiated at 77 K and at room temperature, this compound gave the stable paramagnetic species represented by the single ESR line centered at g = 2.000. We ascribe this spectrum to the CO2- radical formed from the oxalate ion. The same aluminosilicate prepared in the absence of the oxalate either produced no stable paramagnetic product after gamma irradiation at room temperature or resulted in composite ESR spectra, indicating the presence of several paramagnetic species if irradiated at 77 K. Complex ESR spectra were transformed by heating to the stable paramagnetic centers which differed from the one obtained from oxalate ion. We conclude that in Al2(OH)6H4SiO4 oxalate acts as a trap for the gamma-radiation energy.

  18. A biosensor for monitoring formaldehyde using a new lipophilic tetrathiafulvalene-tetracyanoquinodimethane salt and a polyurethane membrane.

    PubMed

    Kataky, R; Bryce, M R; Goldenberg, L; Hayes, S; Nowak, A

    2002-03-01

    A format for a disposable screen-printed biosensor was investigated for monitoring formaldehyde. The screen-printed sensor format comprised a working electrode (WE) modified with platinised carbon, a new lipophilic tetrathiafulvalene-tetracyanoquinodimethane (TTF-TCNQ) salt as mediator, a plasticised polyurethane membrane (TECOFLEX SG80, PU) with anionic sites and the enzyme (formaldehyde dehydrogenase FOH) and co-factor (beta-NAD(+)). The new lipophilic TTF-TCNQ salt gave a smooth, robust electrode surface rather than microcrystalline deposits of the salt observed with TTF-TCNQ salts. Entrapment of the enzyme and co-factor behind a plastcised PU membrane with anionic sites enhanced the sensitivity and stability of the sensor. A linear response between 10(-3) and 10(-4) mol dm(-3) was observed. To demonstrate the feasibility of the use of the screen-printed sensor to monitoring formaldehyde in ambient air, preliminary experiments were carried out in the vicinity of a local medium density fibreboard factory and its performance compared to that of a biosensor made from the same platinised carbon and enzyme system, but without the lipophilic TTF-TCNQ and membrane, using a commercial 'Rank' cell. Samples were collected using a Molspin 'Super-sniffer'. PMID:18968517

  19. Development of receptor bronchial system in isolated preparation of piglet trachea in vitro.

    PubMed

    Bexheti, Sadi; Haliti, Naim; Islami, Hilmi; Sukalo, Aziz; Nuraj, Bajram; Krasniqi, Valon; Kutllovci, Skender; Beqiraj, Rruke; Disha, Mentor

    2010-01-01

    In this paper we present the flow research of the development of receptor bronchial system in the first month of extra-uterine life up to the sixth month of development, performed by tracking the reactions of isolated tracheal rings in acetylcholine (Ach), propranolol (P), histamine (Hist), and prostaglandin (PGF2-alfa) in concentrations of: 10-4, 10-3, 10-2 and 10-1 mol/dm3; in piglets of ages: 1 month, 2 months, 4 months and 6 months. Results shows that Ach causes reaction of smooth muscles from the first month of extra-uterine life (p < 0.01) and that Propranolol (P) significantly emphasizes the effect of Ach (p > 0.1), while histamine and PGF2-alpha do not cause constriction (histamine up to 4 months of age, PGF2-alfa up to 6 months of extra-uterine life). This shows that cholinergic and adrenergic system in piglet airways is developed during intrauterine life and reaction can be registered in the first month of extra-uterine life, while other receptor systems are developed in later periods of extra-uterine life. This suggests that lack of reaction of tracheal smooth musculature (TSM) comes as a result of sufficient non-maturity of mast cells from which chemical mediators, with local functioning, are released. PMID:20514768

  20. Role of meconium in the reaction of airways smooth musculature in the newborn with meconium aspiration syndrome (MAS).

    PubMed

    Islami, Hilmi; Bexheti, Sadi; Shabani, Ragip; Nuraj, Bajram; Zeqiri, Fehmi; Sukalo, Aziz; Kurtishi, Ilir; Kutllovci, Skender; Qorraj, Hasime; Disha, Mentor

    2009-11-01

    The role of meconium in the respiratory system was studied in newborns, who died from various causes (250 up to 3000 g of weight). We monitored tracheal rings response to dopamine, serotonin and ethanol in different concentrations (dopamine: 0,05 mg/ml, 0,5 mg/ml, 5 mg/ml; serotonin (5-HT): 10-4, 10-3, 10-2, 10-1 mol/dm3; ethanol: 0,02 ml, 0,5 ml, 1,0 ml; 96%). Tracheal smooth musculature tonus (TSM) was examined in 48 tracheal preparations taken after the newborn exitus due to different reasons. Based on functional researche of isolated preparations of tracheas, it may be concluded that: aspiration of meconium has not changed the response of TSM to dopamine, serotonin and ethanol (p>0,1) in comparison with the control group, which have died due to different lung inflammatory processes (e.g. pneumonia, bronchopneumonia, atelectasis, cerebral hemorrhage). The results suggest that meconium does not potentiate the constricting action of dopamine, serotonin and ethanol in tracheobronchial system. Meconium causes mild relaxation of the TSM through a mechanism that is not intermediated by the products of cyclooxygenases (prostaglandins, prostacyclins) from the tracheal epithelium or proteins. Also, as it seems, the direct activity of many tested acids in the smooth musculature has no significant impact on increase of the airways tonus in MAS syndrome. PMID:20002002

  1. Synthesis, crystal structure and third-order non-linear optical properties of a Zn(II) two-dimensional polymer

    NASA Astrophysics Data System (ADS)

    Li, Yong; Zhang, Zhaoxia; Cui, Xiaobing; Li, Teng; Li, Kechang

    2010-05-01

    Two-dimensional (2-D) metal-organic polymer [Zn 3(μ 2-4,4'-bipy) 2(μ 2-be) 2(be) 2(μ 2-N 3) 2] n1 (4,4'-bipy = 4,4'-bipyridine, be = benzoate, N 3- = azide anion) has been synthesized by low-hot reaction and characterized by single-crystal X-ray diffraction, elemental analyses, IR spectra and UV-visible spectra. The 2-D structure is built from the linkage of secondary building units of trinuclear [Zn 3(μ 2-4,4'-bipy) 2(μ 2-be) 2(be) 2(μ 2-N 3) 2] clusters by a mixed connector of 4,4'-bipyridine, benzoate and azide. The third-order non-linear optical (NLO) properties of the 1 were also investigated with modulus of the hyperpolarizability ( γ) 8.51 × 10 -30 esu for 1 in a 3.17 × 10 -4 mol dm -3 DMF solution.

  2. The Examination of Afyonkarahisar's Geothermal System Corrosion

    NASA Astrophysics Data System (ADS)

    Buyuksagis, A.; Erol, S.

    2013-02-01

    Corrosion and scaling of metal surfaces are the major problems caused by geothermal fluids when metallic structures are used. This article describes a study of corrosion and scaling problems in the Afyonkarahisar Geothermal Heating System (AFJET) in Afyonkarahisar, Turkey. Water analysis, XRD, SEM, EDX, IC, ICP-OES analyses, and electrochemical methods were used in this study. Pentasodium triphosphate (Na5P3O10), maleic anhydride (C4H2O3), and 1,3-benzendisulfonic acid disodium salt (C6H4Na2O6S2) were used as corrosion inhibitors. Tests were carried out using geothermal water from AF11 well. The experimental temperatures were chosen as 298, 333, and 358 K. Inhibitor concentrations were chosen as 1 × 10-1, 1 × 10-2, 1 × 10-3, and 1 × 10-4 mol/dm3. Moreover, mixed inhibitor solutions were prepared using the inhibitor concentrations that showed the best inhibition. The first mixed inhibitor solution showed 96% inhibition. The second mixed inhibitor solution showed 90% inhibition. The tested inhibitors act as anodic inhibitors. XRD analysis shows that there is CaCO3 aragonite scaling in the system. Increasing TDS, alkalinity, and hardness all promote scale formation. The photomicrographs from SEM-EDX and the metallographic microscope show that the tested inhibitors form a protective film on the surface. IC and ICP-OES analyses show that the concentration of Ca2+ is very high, which supports scale formation.

  3. Response of Smooth Bronchial Musculature in Bronchoconstrictor Substances in Newborn with Lung Atelectasis at the Respiratory Distress Syndrome (RDS)

    PubMed Central

    Mustafa, Lirim; Islami, Pëllumb; Shabani, Nora; Jashanica, Adelina; Islami, Hilmi

    2014-01-01

    ABSTRACT Objective: Role of the atelectasis (hypoxia) in the respiratory system of the live and exited newborn (250 up to 3000 g. of body weight), which has died due to different causes was studied in this work. Methods: Response of tracheal rings to dopamine, serotonine and ethanol in the different molar concentrations (dopamine: 0,05 mg/ml, 0,5 mg/ml, 5 mg/ml; serotonine (5-HT): 10-4, 10-3, 10-2, 10-1 mol/dm3; ethanol: 0,2 ml, 0,5 ml, 1,0 ml; 96%) was followed up. Study of the smooth tracheal musculature tone (STM) was elaborated in 16 tracheal preparations taken following the newborn death due to different causes. Results: Based on functional researches of tracheal isolated preparations, it was ascertained as follows: atelectasis (cases born with lung hypoxia) has changed the response of STM to dopamine, serotonine and ethanol in a significant manner (p<0,01) in comparison to cases of controlling group, which has died due to lung inflammatory processes (e.g. pneumonia, bronchopneumonia, cerebral hemorrhage), which have also caused significant response (p<0,05). Conclusion: Results suggest that exited cases from lung atelectasis and cases of controlling group reacts to above mentioned substances by causing significant constrictor action of tracheobronchial system. PMID:24783902

  4. Synthesis, crystal structure and third-order non-linear optical properties of a two-dimensional coordination network [Cd(AcO)2(L)2(H2O)

    NASA Astrophysics Data System (ADS)

    Zhang, Zhao-Xia; Pan, Wei-Cheng; Hong, Peng-Zhi; Li, Ke-Chang; Li, Yong

    2015-02-01

    A novel two-dimensional (2-D) Cd(II) coordination network [Cd(AcO)2(L)2(H2O)] 1 (AcO = acetate, L = 4-(1,2,4-triazol-1-yl) benzoic acid ethyl ester) has been synthesized by low-temperature solid-state reaction and characterized by single-crystal X-ray diffraction, elemental analyses, IR spectra and UV-visible spectra. The molecules of the complex are interconnected into layers by O-H⋯O and C-H⋯O hydrogen bonds in which participate AcO-, L and H2O ligands. The intermolecular hydrogen-bonds interactions are the most significant factors controlling the novel supramolecular sheet fashion packing of the title compound in the crystal state. The third-order non-linear optical (NLO) properties of the title compound 1 were also investigated and they exhibit the reverse saturable absorption and self-defocusing performance with modulus of the hyperpolarizability (γ) 2.30 × 10-30 esu for 1 in a 2.15 × 10-4 mol dm-3 DMF solution.

  5. A new selective chromogenic reagent for the spectrophotometric determination of thallium(I) and (III) and its separation using flotation and the solid-phase extraction on polyurethane foam.

    PubMed

    Abou-El-Sherbini, Khaled S; Mostafa, Gamal A E; Hassanien, Mohamed M

    2003-09-01

    A new sensitive chromogenic reagent, 9,10-phenanthaquinone monoethylthiosemicarbazone (PET), has been synthesized and used in the spectrophotometric determination of Tl(III). In HNO3, H2SO4 or H3PO4 acids, PET can react immediately at room temperature with Tl(III) to form a red 2:1 complex with a maximum absorption at 516 nm. The different analytical parameters affecting the extraction and determination processes have been examined. The calibration curve was found to be linear over the range 0.2-10 microg cm(-3) with a molar absorptivity of 2.2 x 10(4) dm3 mol(-1) cm(-1). Sandell's sensitivity was found to be 0.0093 microg cm(-2). No interference from macroamounts of foreign ions was detected, except for Pd(II). However, Pd(II) does not affect the determination process, because its complex with PET has its lambda(max) at 625 nm. The proposed method has been applied to the determination of Tl(I and III) in synthetic and natural samples after separation by flotation (in oleic acid/kerosene) and solid-phase extraction (on polyurethane foam) techniques. The two methods were found to be accurate and not subject to random error, but solid-phase extraction was preferred because it is cheap, simpler and there is no contamination risk coming from flotation reagents. PMID:14516078

  6. Adsorption mechanisms of RNA mononucleotides on silver nanoparticles

    NASA Astrophysics Data System (ADS)

    Miljanić, Snežana; Dijanošić, Adriana; Matić, Ivona

    2015-02-01

    Surface-enhanced Raman scattering (SERS) of four RNA mononucleotides (AMP, GMP, CMP and UMP) has been studied on the citrate-reduced silver colloid aggregated with sodium sulfate. Concentration dependent spectra in the range of 1 × 10-7-1 × 10-4 mol dm-3 were obtained, assigned and interpreted according to the surface selection rules. For purine mononucleotides, AMP and GMP, adsorption onto the silver nanoparticles through the six-membered ring of the nitrogenous base was suggested. Concentration dependent splitting of the ring breathing band in the spectra of AMP indicated coexistence of two species on the silver surface, which differed in contribution of the adenine N1 atom and the exocyclic NH2 group in binding. Unlike the AMP spectra, the spectra of GMP implied only one mode of adsorption of the molecules onto the silver nanoparticles, taking place through the guanine N1H and Cdbnd O group. Weak SERS spectra of pyrimidine mononucleotides, CMP and UMP, pointed to involvement of carbonyl oxygen in adsorption process, whereby the molecules adopted the position on the nanoparticles with ribose close to the metal surface. Intense bands in the low wavenumber region, associated with stretching of the formed Agsbnd N and/or Agsbnd O bonds, supported chemical binding of the RNA mononucleotides with the silver surface.

  7. The system NaCl-CaCl[sub 2]-H[sub 2]O; 2: Densities for ionic strengths of 0. 1--19. 2 mol[center dot]kg[sup [minus]1] at 298. 15 and 308. 15 K and at 0. 1 MPa

    SciTech Connect

    Oakes, C.S.; Bodnar, R.J. . Dept. of Geological Sciences); Simonson, J.M. . Chemistry Division)

    1990-01-01

    Data on the physical properties of the ternary system NaCl-CaCl[sub 2]-H[sub 2]O are of particular importance in the processing and disposal of brines produced from industrial processes, chemical manufacture, and petroleum and geothermal reservoirs. Densities for ternary solutions in the system NaCl-CaCl[sub 2]-H[sub 2]O were measured with a vibrating-tube densimeter at 298.15 [+-] 0.09 and 308.15 [+-] 0.03 K and 0.1 MPa and over a range of ionic strengths from 0.1 to 19.2 mol[center dot]kg[sup [minus]1]. The present results are in excellent agreement with previously published data for the NaCl-H[sub 2]O binary and are in very good agreement with the more precise of the available data for the CaCl[sub 2]-H[sub 2]O binary at 298.15 K. Very large discrepancies between the results of the three most recent reports of densities for the CaCl[sub 2]-H[sub 2]O system at 308.15 K are resolved here, improving both the accuracy and precision for this system. Most significantly, the results reported here substantially expand the volumetric data base for ternary solutions. On the basis of the results of this study, most of the previously reported 308.15 K density data in the ternary system appear to contain large errors. The authors have evaluated the data within the framework of the Pitzer formalism and obtain new values for the ion interaction and mixing parameters for this ternary system. In addition to the parameters determined from the binary end-member solutions, it was found that only [theta][sub NaCa][sup v] was needed to represent the ternary results.

  8. A note on the temperature dependence of Henry's Law coefficients for methanol and ethanol

    NASA Astrophysics Data System (ADS)

    Warneck, Peter

    Measurements reported in the literature of gas-liquid partition coefficients for methanol and ethanol dissolved in water are compiled and critically evaluated to establish the temperature dependence. The data are linearly correlated in the ln( KH[mol dm -3 atm -1]) versus reciprocal absolute temperature coordinate frame and, when treated by a linear regression analysis, yield: ln( KH)=-(12.46±0.25)+(5312.4±76.0)/ T in the case of methanol (0-80 °C) and ln( KH)=-(15.87±0.82)+(6274.0±241.6)/ T in the case of ethanol (0-60 °C). The measurements at 25 °C average to KH(298.15)=(2.16±0.14)×10 2 mol dm -3 atm -1 ( n=8) and KH(298.15)=(1.94±0.13)×10 2 mol dm -3 atm -1 ( n=8), respectively. Enthalpies of solution derived from the temperature dependence are 44.17±0.63 kJ mol -1 for methanol and 52.16±2.01 kJ mol -1 for ethanol.

  9. 22 CFR 19.10-4 - Death or divorce of a spouse and remarriage after retirement.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...-4 Death or divorce of a spouse and remarriage after retirement. (a) If the marriage of an annuitant... necessary, as of the first of the month following the death or divorce. If the marriage was dissolved by death, the annuity shall be recomputed and paid at its full amount. If the marriage is dissolved...

  10. 22 CFR 19.10-4 - Death or divorce of a spouse and remarriage after retirement.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...-4 Death or divorce of a spouse and remarriage after retirement. (a) If the marriage of an annuitant... necessary, as of the first of the month following the death or divorce. If the marriage was dissolved by death, the annuity shall be recomputed and paid at its full amount. If the marriage is dissolved...

  11. Detail design of a 10.4-m stretched-membrane dish. Phase 2, Final report

    SciTech Connect

    Not Available

    1994-01-01

    This report describes efforts conducted under Tasks 3 and 4 of the second phase of the project to develop a single-element stretched-membrane dish concept to reduce the cost of a high-performance concentrating solar collector. We completed the detailed design for such a collector suitable to drive a 25-kWe Stirling motor generator. The design includes the collectors, optical element, the drive, and support systems. The aperture of the optical element was sized to provide the required energy to the engine based on test data and analytical models of the concentrator receiver, and engine. The design of the optical element was improved based on experience gained from the design, fabrication, and testing of several prototypes.

  12. Financial services FY 1996 site support program plan, WBS 6.10.4. Revision 1

    SciTech Connect

    Schafer, D.D.

    1995-09-01

    This program plan outlines the financial services to be provided to the Hanford reservation by the Westinghouse Hanford Company. The topics of the plan include the Hanford strategic plan, program mission, program strategy, technical requirements baseline, schedule baseline, cost baseline, performance measures, technical objectives, program performance and program funding required.

  13. 22 CFR 19.10-4 - Death or divorce of a spouse and remarriage after retirement.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 22 Foreign Relations 1 2012-04-01 2012-04-01 false Death or divorce of a spouse and remarriage...-4 Death or divorce of a spouse and remarriage after retirement. (a) If the marriage of an annuitant... spouse is dissolved by divorce or by death of the spouse, the retiree's annuity shall be recomputed,...

  14. 25 CFR 10.4 - What happens if the policies and standards are not followed?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... not followed? The risk for human and civil rights violations due to lack of common standards will... funding from potential resource sharing agreements with other law enforcement agencies may be...

  15. Modeling Interacting Galaxies or how to perform 10^4 simulations in a minute?

    NASA Astrophysics Data System (ADS)

    Harfst, Stefan; Theis, Christian

    Genetic algorithms (GAs) are powerful tools for optimization and search problems. E.g. they can be applied for investigating the extended parameter space of interacting galaxies (Theis, 1999). Their general idea is to mimic natural evolution: A population of individuals represented by chromosomes which correspond to single points in parameter space (i.e. single N-body simulations) is evolved according to the principle of ``survival of the fittest''. The fitness is calculated by a comparison of observed intensities with the numerical model. New individuals are created by ``sexual reproduction'' whereas the probability for an individual to become a parent increases with its fitness. After two individuals are chosen as parents cross-over and mutation operators are applied to their chromosomes. This breeding is repeated until a sufficient fit is achieved. A typical fit consisting of 100 generations and a population with 100 members (10000 models) takes about 3 CPU-hours on a Pentium-II processor. In order to study more extended parameter spaces, as in the case of groups of galaxies, a considerably larger population is desired. A substantial gain in performance can be achieved by a parallel implementation of a GA. Even for the simplest approach where only the evaluation of fitness is done in parallel one can expect a speedup up to two orders of magnitude. An additional speedup might be achieved by a more sophisticated GA method, the so called ``island model'': In this case the population is divided into subpopulations that evolve isolated from each other most of the time and exchange individuals only occasionally, by this simulating migration.

  16. 22 CFR 19.10-4 - Death or divorce of a spouse and remarriage after retirement.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...-4 Death or divorce of a spouse and remarriage after retirement. (a) If the marriage of an annuitant... necessary, as of the first of the month following the death or divorce. If the marriage was dissolved by death, the annuity shall be recomputed and paid at its full amount. If the marriage is dissolved...

  17. 22 CFR 19.10-4 - Death or divorce of a spouse and remarriage after retirement.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...-4 Death or divorce of a spouse and remarriage after retirement. (a) If the marriage of an annuitant... necessary, as of the first of the month following the death or divorce. If the marriage was dissolved by death, the annuity shall be recomputed and paid at its full amount. If the marriage is dissolved...

  18. Equilibrium studies of copper ion adsorption onto palm kernel fibre.

    PubMed

    Ofomaja, Augustine E

    2010-07-01

    The equilibrium sorption of copper ions from aqueous solution using a new adsorbent, palm kernel fibre, has been studied. Palm kernel fibre is obtained in large amounts as a waste product of palm oil production. Batch equilibrium studies were carried out and system variables such as solution pH, sorbent dose, and sorption temperature were varied. The equilibrium sorption data was then analyzed using the Langmuir, Freundlich, Dubinin-Radushkevich (D-R) and Temkin isotherms. The fit of these isotherm models to the equilibrium sorption data was determined, using the linear coefficient of determination, r(2), and the non-linear Chi-square, chi(2) error analysis. The results revealed that sorption was pH dependent and increased with increasing solution pH above the pH(PZC) of the palm kernel fibre with an optimum dose of 10g/dm(3). The equilibrium data were found to fit the Langmuir isotherm model best, with a monolayer capacity of 3.17 x 10(-4)mol/g at 339K. The sorption equilibrium constant, K(a), increased with increasing temperature, indicating that bond strength between sorbate and sorbent increased with temperature and sorption was endothermic. This was confirmed by the increase in the values of the Temkin isotherm constant, B(1), with increasing temperature. The Dubinin-Radushkevich (D-R) isotherm parameter, free energy, E, was in the range of 15.7-16.7kJ/mol suggesting that the sorption mechanism was ion exchange. Desorption studies showed that a high percentage of the copper was desorbed from the adsorbent using acid solutions (HCl, HNO(3) and CH(3)COOH) and the desorption percentage increased with acid concentration. The thermodynamics of the copper ions/palm kernel fibre system indicate that the process is spontaneous and endothermic. PMID:20346574

  19. A mixed acid based vanadium-cerium redox flow battery with a zero-gap serpentine architecture

    NASA Astrophysics Data System (ADS)

    Leung, P. K.; Mohamed, M. R.; Shah, A. A.; Xu, Q.; Conde-Duran, M. B.

    2015-01-01

    This paper presents the performance of a vanadium-cerium redox flow battery using conventional and zero-gap serpentine architectures. Mixed-acid solutions based on methanesulfonate-sulfate anions (molar ratio 3:1) are used to enhance the solubilities of the vanadium (>2.0 mol dm-3) and cerium species (>0.8 mol dm-3), thus achieving an energy density (c.a. 28 Wh dm-3) comparable to that of conventional all-vanadium redox flow batteries (20-30 Wh dm-3). Electrochemical studies, including cyclic voltammetry and galvanostatic cycling, show that both vanadium and cerium active species are suitable for energy storage applications in these electrolytes. To take advantage of the high open-circuit voltage (1.78 V), improved mass transport and reduced internal resistance are facilitated by the use of zero-gap flow field architecture, which yields a power density output of the battery of up to 370 mW cm-2 at a state-of-charge of 50%. In a charge-discharge cycle at 200 mA cm-2, the vanadium-cerium redox flow battery with the zero-gap architecture is observed to discharge at a cell voltage of c.a. 1.35 V with a coulombic efficiency of up to 78%.

  20. Removal of nickel(II) ions from aqueous solutions using the natural clinoptilolite and preparation of nano-NiO on the exhausted clinoptilolite

    NASA Astrophysics Data System (ADS)

    Rajic, Nevenka; Stojakovic, Djordje; Jovanovic, Mina; Logar, Natasa Zabukovec; Mazaj, Matjaz; Kaucic, Venceslav

    2010-12-01

    The natural zeolite tuff (clinoptilolite) from a Serbian deposit has been studied as adsorbent for Ni(II) ions from aqueous solutions. Its sorption capacity at 298 K varies from 1.9 mg Ni g -1 (for the initial solution concentration of 100 mg Ni dm -3) to 3.8 mg Ni g -1 (for C0 = 600 mg Ni dm -3) and it increases 3 times at 338 K. The sorption is best described by the Sips isotherm model. The sorption kinetics follows the pseudo-second-order model, the activation energies being 7.44, 5.86, 6.62 and 6.63 kJ mol -1 for C0 = 100, 200, 300 and 400 mg Ni dm -3, respectively. The sorption involves a film diffusion, an intra-particle diffusion, and a chemical cation-exchange between the Na + ions of clinoptilolite and the Ni 2+ ions. The sorption is endothermic (Δ H° being 37.9, 33.4, 30.0, 27.7 and 24.3 kJ mol -1 for C0 = 100, 200, 300, 400 and 600 mg Ni dm -3, respectively) and spontaneous in the 298-338 K temperature range. Thermal treatment of the Ni(II)-loaded clinoptilolite results in the formation of spherical nano-NiO particles of approx. 5 nm in diameter which are randomly dispersed in the clinoptilolite lattice.

  1. An annual survey of bacterial production, respiration and ectoenzyme activity in coastal NW Mediterranean waters: temperature and resource controls.

    PubMed

    Céa, B; Lefèvre, D; Chirurgien, L; Raimbault, P; Garcia, N; Charrière, B; Grégori, G; Ghiglione, J F; Barani, A; Lafont, M; Van Wambeke, F

    2015-09-01

    We simultaneously measured bacterial production (BP), bacterial respiration (BR), alkaline phosphatase activity (phos) and ectoaminopeptidase activity (prot) in relation to biogeochemical parameters, nutritive resources and in situ temperature over a 1-year survey at the long-term observatory the SOLEMIO station (Marseille bay, NW Mediterranean Sea). Despite its proximity to the coast, oligotrophic conditions prevailed at this station (yearly mean of Chl a = 0.43 μg dm(-3), NO3 = 0.55 μmol dm(-3) and PO4 = 0.04 μmol dm(-3)). Episodic meteorological events (dominant winds, inputs from the Rhone River) induced rapid oscillations (within 15 days) in temperature and sometimes salinity that resulted in rapid changes in phytoplankton succession and a high variability in C/P ratios within the particulate and dissolved organic matter. Throughout the year, BP ranged from 0.01 to 0.82 μg C dm-(3) h-(1) and bacterial growth efficiency varied from 1 to 39%, with higher values in summer. Enrichment experiments showed that BP was limited most of the year by phosphorus availability (except in winter). A significant positive correlation was found between in situ temperature, BP, BR and phos. Finally, we found that temperature and phosphate availability were the main factors driving heterotrophic bacterial activity and thus play a fundamental role in carbon fluxes within the marine ecosystem. PMID:25217279

  2. Influence of lactose on the diffusion of calcium ions at physiological temperature.

    PubMed

    Verissimo, Luis M P; Ribeiro, Vânia C M; Ribeiro, Ana C F; Melia Rodrigo, M; Esteso, Miguel A

    2014-11-15

    Mutual diffusion coefficients for calcium chloride (0.100 mol dm(-3)) in aqueous solutions containing lactose at various concentrations (from 0.005 to 0.200 mol dm(-3)) have been measured at 37°C (physiological temperature), by using a conductimetric cell coupled to an automatic system to follow the diffusion. This cell uses an open-ended capillary method based on the measurement of the electrical resistance of a solution placed inside the capillaries at recorded times. The analysis of the CaCl2 diffusion coefficient values obtained suggests the presence of some CaCl2/lactose aggregates in the media, which are influenced by the temperature. PMID:24912727

  3. Mutual diffusion coefficients in systems containing the nickel ion

    NASA Astrophysics Data System (ADS)

    Ribeiro, Ana C. F.; Veríssimo, Luis V. M. M.; Gomes, Joselaine C. S.; Santos, Cecilia I. A. V.; Barros, Marisa C. F.; Lobo, Victor M. M.; Sobral, Abílio J. F. N.; Esteso, Miguel A.; Leaist, Derek G.

    2013-04-01

    Mutual diffusion coefficients of nickel chloride in water have been measured at 293.15 K and 303.15 K and at concentrations between 0.020 mol dm-3 and 0.100 mol dm-3, using a conductimetric cell. The experimental mutual diffusion coefficients are discussed on the basis of the Onsager-Fuoss model. The equivalent conductances at infinitesimal concentration of the nickel ion in these solutions at those temperatures have been estimated using these results. In addition, from these data, we have estimated some transport and structural parameters, such as limiting diffusion coefficient, ionic conductance at infinitesimal concentration, hydrodynamic radii and activation energy, contributing this way to a better understanding of the structure of these systems and of their thermodynamic behavior in aqueous solution at different concentrations.

  4. Effect of temperature on O⊘ reactions and equilibria: A pulse radiolysis study

    NASA Astrophysics Data System (ADS)

    Elliot, Allen John; McCracken, David Ritchie

    The p Ka of the hydroxyl radical was measured over the 20-80°C temperature range. At 20°C, the p Ka was 11.84 and fell to 10.81 at 80°C. The dissociation constant for the ozonide anion (O⊘ 3⇌O 2+O⊘) was found to be 5.5 × 10 -7 mol dm -3 at 20°C and 46.2 × 10 -7 mol dm -3 at 70°C. The rate constants and activation energies for the reaction of O⊘ and OH with 2-propanol, methanol and 3-hexene-1,6-dicarboxylate ions have also been measured.

  5. Electrochemical properties of LiCoPO4-thin film electrodes in LiF-based electrolyte solution with anion receptors

    NASA Astrophysics Data System (ADS)

    Fukutsuka, Tomokazu; Nakagawa, Takuya; Miyazaki, Kohei; Abe, Takeshi

    2016-02-01

    Compatibility of LiF + anion receptors/propylene carbonate (PC) electrolyte solution with high potential positive electrode for lithium-ion batteries was examined by cyclic voltammetry. As anion receptors, tripropyl borate (TPB), tris(pentafluorophenyl) borane (TPFPB), and tris(hexafluoroisopropyl) borate (THFIPB) were used. LiCoPO4 thin-film electrodes were prepared by sol-gel method and used as both carbon- and binder-free model electrodes. From cyclic voltammograms, LiCoPO4 showed better cycleability in 0.1 mol dm-3 LiF + 0.1 mol dm-3 THFIPB/PC, however, other anion receptors did not give positive influence. It is indicated that the surface protecting layer from F--THFIPB complex and made LiCoPO4 stable. Electrochemical behavior depending on anion receptors was discussed according to reaction activity of F-.

  6. Leaching of Calcareous Bornite Ore in Ammoniacal Solution Containing Ammonium Persulfate

    NASA Astrophysics Data System (ADS)

    Liu, Zhi-xiong; Yin, Zhou-lan; Chen, Yi-guang; Xiong, Li-zhi

    2014-12-01

    The leaching process of copper from calcareous bornite ore using ammonium persulfate as an oxidant in ammoniacal solution was investigated. The effects of stirring speed, temperature, initial concentration of ammonia and ammonium persulfate, and liquid-to-solid (L/S) ratio on the extraction percentage of copper from bornite ore were studied. The results show that the optimum leaching conditions for bornite ore with a maximum extraction of copper 88.9 pct are temperature 313.15 K (40 °C), reaction time 4 hours, stirring speed 600 r /min, L/S ratio 7/1 cm3/g, initial concentration of ammonia 2.0 mol/dm3, and ammonium persulfate 3.0 mol/dm3.

  7. Reaction of alcohol radicals with cyclic disulfides. An optical and conductimetric pulse radiolysis study

    NASA Astrophysics Data System (ADS)

    Anderson, Robert F.; Vojnovic, Borivoj; Patel, Kantilal B.; Michael, Barry D.

    The disulfides lipoamide (LIPA) and oxidized dithiothreitol ( ox-DTT) react with methanol, ethanol, isopropanol and t-butanol radicals in aqueous solution at pH10.8 to form disulfide radical anions. Electron transfer rates range from ca 10 7 dm 3 mol -1s -1 for t-butanol radicals with LIPA to 3.6 × 10 8 dm 3 mol -1s -1 for methanol radicals with LIPA. The formations of the disulfide radical anions were followed by simultaneously monitoring absorption changes at 400 nm and changes in conductance with time. The electron transfer efficiencies are higher for LIPA than for ox-DTT increasing in the series t-butanol ≪isopropanol

  8. Cathodic adsorptive stripping voltammetric determination of uranium with potassium hydrogen phthalate.

    PubMed

    Farghaly, O A; Ghandour, M A

    1999-06-01

    The adsorption properties of dioxouranium (II)-Phathalate complexes onto hanging mercury drop electrode are exploited in developing a highly sensitive and selective stripping voltammetric procedure for the determination of uranium (VI). The reduction current of adsorbed complex ions of U(VI) was measured by both linear sweep (LSCSV) and differential pulse cathodic stripping voltammetry (DPCSV), preceded by a period of preconcentration onto the electrode surface. As low as 2x10(-9) mol dm(-3) (0.5 mug/l) and 2x10(-8) mol dm(-3) (4.8 mug/l) with accumulation time 240 and 120 s using DPCSV and LSCSV, respectively, have been determined successfully. The relative standard deviation of 2.2% at the 5 ppm level was obtained. The interferences of some metal ions and anions were studied. The application of this method was tested in the determination of uranium in superphosphate fertilizer. PMID:18967571

  9. A Cyclic Voltammetry Experiment Illustrating Redox Potentials, Equilibrium Constants, and Substitution Reactions in Coordination Chemistry

    NASA Astrophysics Data System (ADS)

    Toma, Henrique E.; Araki, Koiti; Dovidauskas, Sergio

    2000-10-01

    We report a cyclic voltammetry experiment focusing on the [RuIII(EDTA)(H2O)]- complex and its equilibrium reaction with dimethyl sulfoxide (DMSO) in aqueous solution, yielding the [RuIII(EDTA)(kS-DMSO)]- complex. From the electrochemistry data, the formation constants for the [RuIII(EDTA)(kS-DMSO)]- and [RuII(EDTA)(kS-DMSO)]2- complexes were calculated as 2.0 mol-1 dm3 and 2.7 x 109 mol-1 dm3, respectively. The results illustrate the kinetic lability of the ruthenium(III)-EDTA complexes and the role of backbonding stabilization in ruthenium(II)-DMSO complexes. The experiment has been successfully performed in a Coordination Chemistry course, exploiting fundamental aspects of metal complexes and the applications of that important electrochemical technique.

  10. Decomposition of persistent pharmaceuticals in wastewater by ionizing radiation

    NASA Astrophysics Data System (ADS)

    Kimura, Atsushi; Osawa, Misako; Taguchi, Mitsumasa

    2012-09-01

    Pharmaceuticals in wastewater were treated by the combined method of activated sludge and ionizing radiation in laboratory scale. Oseltamivir, aspirin, and ibuprofen at 5 μmol dm-3 in wastewater were decomposed by the activated sludge at reaction time for 4 h. Carbamazepine, ketoprofen, mefenamic acid, clofibric acid, and diclofenac were not biodegraded completely, but were eliminated by γ-ray irradiation at 2 kGy. The rate constants of the reactions of these pharmaceuticals with hydroxyl radicals were estimated by the competition reaction method to be 4.0-10×109 mol-1 dm3 s-1. Decompositions of the pharmaceuticals in wastewater by ionizing radiation were simulated by use of the rate constants and the amount of total organic carbon as parameters. Simulation curves of concentrations of these pharmaceuticals as a function of dose described the experimental data, and the required dose for the elimination of them in wastewater by ionizing radiation can be estimated by this simulation.

  11. Host-guest interaction of flavanone and 7-aminoflavone with C-Hexylpyrogallol[4]arene

    NASA Astrophysics Data System (ADS)

    Chandrasekaran, Sowrirajan; Enoch, Israel V. M. V.

    2014-11-01

    In this paper, we report the structures of the host-guest complexes of flavanone and 7-aminoflavone (guests) with C-Hexylpyrogallol[4]arene (host). The study of the host-guest binding is carried out using UV-Visible absorption, steady-state and time-resolved fluorescence, and 2D ROESY spectroscopy. The stoichiometry and the binding constant of the C-Hexylpyrogallol[4]arene-guest complexes are reported based on absorption and fluorescence titrations. Both flavanone and 7-aminoflavone form 1:1 complexes with the host with binding constant values of 1.71 × 104 mol-1 dm3 and 2.06 × 104 mol-1 dm3 respectively. Fluorescence quenching of the two flavonoids on complex formation occurs and the Stern-Volmer constants are reported. The mode of binding of flavanone and 7-aminoflavone with the host molecule is optimized with 2D ROESY and the structures of the inclusion complexes are proposed.

  12. Stabilization of emulsions using polymeric surfactants based on inulin.

    PubMed

    Tadros, Th F; Vandamme, A; Levecke, B; Booten, K; Stevens, C V

    2004-05-20

    The use of polymeric surfactants for stabilization of emulsions is described. A brief account of general classification and description of polymeric surfactants is given. This is followed by a description of the adsorption and conformation of polymeric surfactants at interfaces. The theoretical approaches for studying polymer adsorption are briefly described. This is followed by a section on the experimental techniques that can be applied to study adsorption and conformation of polymers at the interface. Examples are given to illustrate the experimental techniques. A section is devoted to the interaction between droplets containing adsorbed polymer layers (steric stabilization). The last section gives results on oil-in-water (O/W) emulsions stabilised with a novel graft copolymeric surfactant based on inulin that has been modified by introducing alkyl groups. Two oils were used, namely Isopar M (isoparaffinic oil) and cyclomethicone. Emulsions prepared using the inulin-based surfactant have large droplets, but this could be significantly reduced by addition of a cosurfactant in the oil phase, namely Span 20. The stability of the emulsions was investigated in water, in 0.5, 1.0, 1.5 and 2 mol dm(-3) NaCl and in 0.5, 1.0, 1.5 and 2 mol dm(-3) MgSO(4). These emulsions were stable for more than 1 year up to 50 degrees C in NaCl concentrations up to 2 mol dm(-3) and 1 mol dm(-3) MgSO(4). This high stability in high electrolyte concentrations could be attributed to the nature of the hydrophilic (stabilizing) polyfructose chain. This was confirmed using cloud point measurements, which showed high hydration of the polyfructose chain in such high electrolyte concentrations. This ensured the long-term physical stability resulting from the strong steric repulsion between the polyfructose chains. PMID:15072943

  13. Catalytic-Oxidative Leaching of Low-Grade Complex Zinc Ore by Cu (II) Ions Produced from Copper Ore in Ammonia-Ammonium Sulfate Solution

    NASA Astrophysics Data System (ADS)

    Liu, Zhi Xiong; Yin, Zhou Lan; Hu, Hui Ping; Chen, Qi Yuan

    2012-10-01

    The catalytic-oxidative leaching of a mixed ore, which consists of low-grade oxide copper ore and oxide zinc ore containing ZnS, was investigated in ammonia-ammonium sulfate solution. The effect of the main parameters, such as mass ratio of copper ore to zinc ore, liquid-to-solid ratio, concentration of lixivant, leaching time, and temperature, was studied. The optimal leaching conditions with a maximum extraction of Cu 92.6 pct and Zn 85.5 pct were determined as follows: the mass ratio of copper ore to zinc ore 4/10 g/g, temperature 323.15 K (50 °C), leaching time 6 hours, stirring speed 500 r/min, liquid-to-solid ratio 3.6/1 cm3/g, concentration of lixivant including ammonia 2.0 mol/dm3, ammonium sulfate 1.0 mol/dm3, and ammonium persulfate 0.3 mol/dm3. It was found that ZnS in the oxide zinc ore could be extracted with Cu(II) ion, which was produced from copper ore and was used as the catalyst in the presence of ammonium persulfate.

  14. UV-Vis, fluorescence and NMR spectroscopic investigations on inclusion properties of a designed tetrahomocalix[8]arene with fullerenes C 60 and C 70 in solution

    NASA Astrophysics Data System (ADS)

    Halder, Amal; Bhatt, Suchitra; Nayak, Sandip K.; Chattopadhyay, Subrata; Bhattacharya, Sumanta

    2011-12-01

    The present article reports the spectroscopic investigations on non-covalent interaction of fullerenes C 60 and C 70 with a macrocyclic receptor molecule, namely, 1,3,5,7-tetrahomo- p- tert-butylcalix[8]arene ( 1) in toluene. Jobs method of continuous variation reveals 1:1 stoichiometry for the fullerene complexes of 1. The most fascinating feature of the present study is that 1 binds selectively C 60 compared to C 70 as obtained from binding constant ( K) data of C 60- 1 ( KC60- 1) and C 70- 1 ( KC70- 1) complexes which are enumerated to be 265,000 dm 3 mol -1 and 63,430 dm 3 mol -1, respectively, and selectivity in binding ( KC60- 1/K C70- 1) is estimated to be 4.18 as obtained from UV-Vis study. Steady state fluorescence studies reveal quenching of fluorescence of 1 in presence of fullerenes and the K value of the C 60- 1 and C 70- 1 complexes are estimated to be 80,760 and 68,780 dm 3 mol -1, respectively, with selectivity in binding (K C60- 1/K C70- 1) ˜1.18. 1H NMR analysis provides very good support in favor of strong binding between C 60 and 1. The high value of K value for C 60- 1 complex indicates that 1 forms an inclusion complex with C 60.

  15. Aggregation of Congo red with surfactants and Ag-nanoparticles in an aqueous solution

    NASA Astrophysics Data System (ADS)

    AL-Thabaiti, Shaeel Ahmed; Aazam, Elham Shafik; Khan, Zaheer; Bashir, Ommer

    2016-03-01

    Self aggregation, sorption, and interaction of Congo red, with cetyltrimethylammonium bromide (CTAB), sodium dodecylsulfate (SDS), Ag+ ions and silver nanoparticles have been determined spectrophotometrically. Congo red self-aggregation was identified from UV-visible spectra due to the shrinkage in an absorption band at 495 nm. The shape of the absorbance spectrum changed entirely with increasing [Congo red] but wavelength maxima remain unchanged. The molar absorptivity was found to be 9804 mol- 1 dm3 cm- 1 at 495 nm. Absorption spectra of Congo red with Ag+ ions show an isosbestic point. The complex formation constant and difference in absorption coefficients were found to be 8.5 × 104 mol- 1 dm3 and 11,764 mol- 1 dm3 cm- 1, respectively. Silver nano-particles could not be used for the catalytic degradation of Congo red because it results in the formation of a strong complex with them. Sodium dodecylsulfate did not show any significant interaction with this dye. Congo red was also used as a probe to determine the critical micellar concentration of CTAB.

  16. Zepto-molar electrochemical detection of Brucella genome based on gold nanoribbons covered by gold nanoblooms

    NASA Astrophysics Data System (ADS)

    Rahi, Amid; Sattarahmady, Naghmeh; Heli, Hossein

    2015-12-01

    Gold nanoribbons covered by gold nanoblooms were sonoelectrodeposited on a polycrystalline gold surface at -1800 mV (vs. AgCl) with the assistance of ultrasound and co-occurrence of the hydrogen evolution reaction. The nanostructure, as a transducer, was utilized to immobilize a Brucella-specific probe and fabrication of a genosensor, and the process of immobilization and hybridization was detected by electrochemical methods, using methylene blue as a redox marker. The proposed method for detection of the complementary sequence, sequences with base-mismatched (one-, two- and three-base mismatches), and the sequence of non-complementary sequence was assayed. The fabricated genosensor was evaluated for the assay of the bacteria in the cultured and human samples without polymerase chain reactions (PCR). The genosensor could detect the complementary sequence with a calibration sensitivity of 0.40 μA dm3 mol-1, a linear concentration range of 10 zmol dm-3 to 10 pmol dm-3, and a detection limit of 1.71 zmol dm-3.

  17. Emissive osmium(II) complexes supported by N-heterocyclic carbene-based C^C^C-pincer ligands and aromatic diimines.

    PubMed

    Chung, Lai-Hon; Chan, Siu-Chung; Lee, Wing-Chun; Wong, Chun-Yuen

    2012-08-20

    Osmium(II) complexes containing N-heterocyclic carbene (NHC)-based pincer ligand 1,3-bis(1-methylimidazolin-2-ylidene)phenyl anion (C(1)^C^C(1)) or 1,3-bis(3-methylbenzimidazolin-2-ylidene)phenyl anion (C(2)^C^C(2)) and aromatic diimine (2,2'-bipyridine (bpy), 1,10-phenanthroline (phen), or 4,4'-diphenyl-2,2'-bipyridine (Ph(2)bpy)) in the form of [Os(C^C^C)(N^N)(CO)](+) have been prepared. Crystal structures for these complexes show that the Os-C(NHC) bonds are essentially single (Os-C(NHC) distances = 2.079(5)-2.103(7) Å). Spectroscopic comparisons and time-dependent density functional theory (TD-DFT) calculations suggest that the lowest-energy electronic transition associated with these complexes (λ(max) = 493-536 nm, ε(max) = (5-10) × 10(3) dm(3) mol(-1) cm(-1), solvent = CH(3)CN) originate from a d(π)(Os(II)) → π*(N^N) metal-to-ligand charge transfer transition, where the d(π)(Os(II)) and π*(N^N) levels contain significant contribution from the C^C^C ligands. All these complexes are emissive in the red-spectral region (674-731 nm) with quantum yields of 10(-4)-10(-2) and emission lifetimes of around 1-6 μs. Transient absorption spectroscopy and spectroelectrochemical measurements have also been used to probe the nature of the emissive excited-states. Overall, this joint experimental and theoretical investigation reveals that the C^C^C ligands can be used to modulate the photophysical properties of a [Os(N^N)] core via the formation of the hybrid [Os + C^C^C] frontier orbitals. PMID:22873818

  18. Degradation of monochlorophenols by γ-irradiation

    NASA Astrophysics Data System (ADS)

    Schmid, S.; Krajnik, P.; Quint, R. M.; Solar, S.

    1997-11-01

    The degradation of aqueous 5 × 10 -4 mol dm -3 2-, 3- and 4-chlorophenol (2-CIP, 3-CIP, 4-CIP) under reducing and oxidizing conditions has been studied by steady state γ-radiolysis. The reaction with e aq- leads to reductive dechlorination which equals the degradation of the chlorophenols. Solely phenol is the major organic compound formed. In N 2O saturated solutions the dehalogenation is much less effective. In the case of 4-CIP 40% and in that of 2- and 3-CIP only 20% of the decomposed substrates are resulting in chlorine free organic compounds. From these pyrocatechol for 2-CIP and hydroquinone for 4-CIP could be identified in minor amounts. Main products are the hydroxylated substrates originating from the primarily formed ortho- and para OH-adducts. These are for 2-CIP: chlorohydroquinone and 3-chlorocatechol, for 3-CIP: chlorohydroquinone, 3- and 4-chlorocatechol and for 4-CIP: 4-chlorocatechol. In the presence of oxygen, where the OH-adducts are converted into peroxyl radicals, the degradation yield of the substrates corresponds to that of OH radicals up to doses of 0.5 kGy. The dechlorination process in this dose range is 50% for 4-CIP, and 33% for 2- and 3-CIP. The position of chlorine on the aromatic ring strongly influences the dehalogenation and degradation process. A pronounced dependency of the dose/yield curves on the oxygen concentration was observed. This indicates that for an efficient degradation process of chlorophenols oxygen supply is necessary during irradiation.

  19. The effect of hydrogen peroxide on uranium oxide films on 316L stainless steel

    NASA Astrophysics Data System (ADS)

    Wilbraham, Richard J.; Boxall, Colin; Goddard, David T.; Taylor, Robin J.; Woodbury, Simon E.

    2015-09-01

    For the first time the effect of hydrogen peroxide on the dissolution of electrodeposited uranium oxide films on 316L stainless steel planchets (acting as simulant uranium-contaminated metal surfaces) has been studied. Analysis of the H2O2-mediated film dissolution processes via open circuit potentiometry, alpha counting and SEM/EDX imaging has shown that in near-neutral solutions of pH 6.1 and at [H2O2] ⩽ 100 μmol dm-3 the electrodeposited uranium oxide layer is freely dissolving, the associated rate of film dissolution being significantly increased over leaching of similar films in pH 6.1 peroxide-free water. At H2O2 concentrations between 1 mmol dm-3 and 0.1 mol dm-3, formation of an insoluble studtite product layer occurs at the surface of the uranium oxide film. In analogy to corrosion processes on common metal substrates such as steel, the studtite layer effectively passivates the underlying uranium oxide layer against subsequent dissolution. Finally, at [H2O2] > 0.1 mol dm-3 the uranium oxide film, again in analogy to common corrosion processes, behaves as if in a transpassive state and begins to dissolve. This transition from passive to transpassive behaviour in the effect of peroxide concentration on UO2 films has not hitherto been observed or explored, either in terms of corrosion processes or otherwise. Through consideration of thermodynamic solubility product and complex formation constant data, we attribute the transition to the formation of soluble uranyl-peroxide complexes under mildly alkaline, high [H2O2] conditions - a conclusion that has implications for the design of both acid minimal, metal ion oxidant-free decontamination strategies with low secondary waste arisings, and single step processes for spent nuclear fuel dissolution such as the Carbonate-based Oxidative Leaching (COL) process.

  20. ExoMol molecular line lists - XIV: The rotation-vibration spectrum of hot SO2

    NASA Astrophysics Data System (ADS)

    Underwood, Daniel S.; Tennyson, Jonathan; Yurchenko, Sergei N.; Huang, Xinchuan; Schwenke, David W.; Lee, Timothy J.; Clausen, Sønnik; Fateev, Alexander

    2016-04-01

    Sulphur dioxide is well-known in the atmospheres of planets and satellites, where its presence is often associated with volcanism, and in circumstellar envelopes of young and evolved stars as well as the interstellar medium. This work presents a line list of 1.3 billion 32S16O2 vibration-rotation transitions computed using an empirically-adjusted potential energy surface and an ab initio dipole moment surface. The list gives complete coverage up to 8000 cm-1 (wavelengths longer than 1.25 μm) for temperatures below 2000 K. Infrared absorption cross sections are recorded at 300 and 500 C are used to validated the resulting ExoAmes line list. The line list is made available in electronic form as supplementary data to this article and at www.exomol.com.

  1. ExoMol line lists XV: A new hot line list for hydrogen peroxide

    NASA Astrophysics Data System (ADS)

    Al-Refaie, Ahmed F.; Polyansky, Oleg L.; Ovsyannikov, Roman I.; Tennyson, Jonathan; Yurchenko, Sergei N.

    2016-05-01

    A computed line list for hydrogen peroxide, H216O2, applicable to temperatures up to T = 1250 K is presented. A semi-empirical high accuracy potential energy surface is constructed and used with an ab initio dipole moment surface as input TROVE to compute 7.5 million rotational-vibrational states and around 20 billion transitions with associated Einstein-A coefficients for rotational excitations up to J = 85. The resulting APTY line list is complete for wavenumbers below 6 000 cm-1 (λ < 1.67 μm) and temperatures up to 1250 K. Room-temperature spectra are compared with laboratory measurements and data currently available in the HITRAN database and literature. Our rms with line positions from the literature is 0.152 cm-1 and our absolute intensities agree better than 10%. The full line list is available from the CDS database as well as at www.exomol.com.

  2. Batch and Continuous Ultrasound Assisted Extraction of Boldo Leaves (Peumus boldus Mol.).

    PubMed

    Petigny, Loïc; Périno-Issartier, Sandrine; Wajsman, Joël; Chemat, Farid

    2013-01-01

    Vegetal extracts are widely used as primary ingredients for various products from creams to perfumes in the pharmaceutical, nutraceutic and cosmetic industries. Having concentrated and active extract is essential, as the process must extract as much soluble material as possible in a minimum time, using the least possible volume of solvent. The boldo leaves extract is of great interest for the industry as it holds a great anti-oxidant activity due to high levels of flavonoids and alkaloids such as boldine. Ultrasound Assisted Extraction (UAE) has been used to improve the efficiency of the plant extraction, reducing extraction time, increasing the concentration of the extract with the same amount of solvent and plant material. After a preliminary study, a response surface method has been used to optimize the extraction of soluble material from the plant. The results provided by the statistical analysis revealed that the optimized conditions were: sonication power 23 W/cm2 for 40 min and a temperature of 36 °C. The optimized parameters of the UAE provide a better extraction compared to a conventional maceration in terms of process time (30 min instead of 120 min), higher yield, more energy saving, cleanliness, safety and product quality. PMID:23481637

  3. Batch and Continuous Ultrasound Assisted Extraction of Boldo Leaves (Peumus boldus Mol.)

    PubMed Central

    Petigny, Loïc; Périno-Issartier, Sandrine; Wajsman, Joël; Chemat, Farid

    2013-01-01

    Vegetal extracts are widely used as primary ingredients for various products from creams to perfumes in the pharmaceutical, nutraceutic and cosmetic industries. Having concentrated and active extract is essential, as the process must extract as much soluble material as possible in a minimum time, using the least possible volume of solvent. The boldo leaves extract is of great interest for the industry as it holds a great anti-oxidant activity due to high levels of flavonoids and alkaloids such as boldine. Ultrasound Assisted Extraction (UAE) has been used to improve the efficiency of the plant extraction, reducing extraction time, increasing the concentration of the extract with the same amount of solvent and plant material. After a preliminary study, a response surface method has been used to optimize the extraction of soluble material from the plant. The results provided by the statistical analysis revealed that the optimized conditions were: sonication power 23 W/cm2 for 40 min and a temperature of 36 °C. The optimized parameters of the UAE provide a better extraction compared to a conventional maceration in terms of process time (30 min instead of 120 min), higher yield, more energy saving, cleanliness, safety and product quality. PMID:23481637

  4. Free-radical scavengers and antioxidants from Peumus boldus Mol. ("Boldo").

    PubMed

    Schmeda-Hirschmann, G; Rodriguez, J A; Theoduloz, C; Astudillo, S L; Feresin, G E; Tapia, A

    2003-04-01

    The dry leaves of Peumus boldus (Monimiaceae) are used in infusion or decoction as a digestive and to improve hepatic complains. Preliminary assays showed free-radical scavenging activity in hot water extracts of boldo leaves, measured by the decoloration of a methanolic solution of the 1,1-diphenyl-2-picryl-hydrazyl radical (DPPH). Assay-guided isolation led to the active compounds. Catechin proved to be the main free-radical scavenger of the extracts. Lipid peroxidation in erythrocytes was inhibited by boldo extracts and fractions at 500 microg/ml with higher effect for the ethyl acetate soluble and alkaloid fractions. The IC50 for catechin and boldine in the lipid peroxidation test were 75.6 and 12.5 microg/ml, respectively. On the basis of dry starting material the catechin content in the crude drug was 2.25% while the total alkaloid calculated as boldine was 0.06%. The activity of boldine was six times higher than catechin in the lipid peroxidation assay. However, the mean catechin:total alkaloid content ratio was 37:1. The relative concentration of alkaloids and phenolics in boldo leaves and their activity suggest that free-radical scavenging effect is mainly due to catechin and flavonoids and that antioxidant effect is mainly related with the catechin content The high catechin content of boldo leaves and its bioactivity suggest that quality control of Boldo folium has to combine the analysis of catechin as well as their characteristic aporphine alkaloids. PMID:12747739

  5. [Storage of cereal bars with mesquite cotyledon (Prosopis chilensis (Mol) Stuntz)].

    PubMed

    Escobar, B; Estévez, A M; Guiñez, M A

    2000-06-01

    The use of walnut or peanut in the elaboration of cereal bars represents a possible risk of undesirable changes during their storage due to their high content of unsaturated fatty acids in the oil; oxidizing of the fatty acids is one of the main causes of deterioration. Development of new snack products implies the use of packages that should protect the food against the damage caused by light and reduce the oxygen concentration of in their interior. The objective of this investigation was to evaluate the physical, chemical and sensory changes in the storage of cereal bars with peanut or walnut and mezquite cotyledon subjected to two thermal treatments, packed in cellophane or milky polypropilene. Four types of bars were elaborated with 6% of mezquite cotyledon, treated by microwaves or toasted, and with 18% of peanut or walnut. The bars were stored for 90 days at room temperature; and each 30 days it was measured moisture content, peroxides index, water activity, sensory quality and acceptability. The peroxides values (4.9-13.8 meq/kg of oil) indicates that the shelf life of the bars in all the studied treatments was 90 days. The packaging materials used allows to maintain in good conditions, for 3 months, the cereals bars of moisture (7.4-11.2%), water activity (0.50-0.65) and sensory acceptability. PMID:11048587

  6. Coprecipitation Synthesis of Superplastic 3 Mol. % Yttria -- Stabilized Tetragonal Zirconia Polycrystalline / Magnesium Aluminate Spinel Nanocomposite

    NASA Astrophysics Data System (ADS)

    Opoku, Michael

    3 mole % Yttria-stabilized tetragonal zirconia polycrystalline/Magnesium aluminate spinel (3Y-TZP/MgAl2O4) nanocomposite have exhibited high strain rate superplasticity at 1.7x10--2 --3.3x10--1 s --1. Low strain rate superplasticity (10--5--10 --3 s--1) has been the main drawback of using superplastic ceramics in industries. Microstructural design of 3Y-TZP/MgAl2O4 composite is a key in obtaining high strain rate superplasticity within the range of 10 --2--100 s--1 ). 3Y-TZP/MgAl2O4 may experience a surge in its application at high temperature if the microstructure is designed to exhibit high strain rates at low temperatures. In the present study, the reverse coprecipitation synthesis technique was adopted to synthesize nanocomposite powders containing 70%3Y-TZP/30%MgAl 2O4 and 60%3Y-TZP/40%MgAl2O4 with microstructural characteristics suitable for superplastic application. It was expected that the coprecipitation synthesis technique route will yield highly homogeneous nanocrystalline composite powders, which could be sintered into a dense component with high thermal stability of the small grains. Microstructual features observed after processing powders of 3Y-TZP/MgAl2O4 revealed that the coprecipitation synthesis is a suitable technique for processing nanocomposite powders for superplastic application.

  7. VizieR Online Data Catalog: Properties of SCUBA cores in Perseus mol. cloud (Curtis+, 2010)

    NASA Astrophysics Data System (ADS)

    Curtis, E. I.; Richer, J. S.

    2013-05-01

    We extracted fully calibrated and reduced SCUBA 850um maps across the four regions in Perseus we observed with HARP from the data presented by Hatchell et al. (2005, Cat. J/A+A/440/151), where we refer the reader for details of the observations and processing. In short, the data were taken during 20 nights between 1999 and 2003. (2 data files).

  8. ExoMol line lists - XV. A new hot line list for hydrogen peroxide

    NASA Astrophysics Data System (ADS)

    Al-Refaie, Ahmed F.; Polyansky, Oleg L.; Ovsyannikov, Roman I.; Tennyson, Jonathan; Yurchenko, Sergei N.

    2016-09-01

    A computed line list for hydrogen peroxide, H216O2, applicable to temperatures up to T = 1250 K is presented. A semi-empirical high-accuracy potential energy surface is constructed and used with an ab initio dipole moment surface as input TROVE to compute 7.5 million rotational-vibrational states and around 20 billion transitions with associated Einstein-A coefficients for rotational excitations up to J = 85. The resulting APTY line list is complete for wavenumbers below 6000 cm-1 (λ < 1.67 μm) and temperatures up to 1250 K. Room-temperature spectra are compared with laboratory measurements and data currently available in the HITRAN data base and literature. Our rms with line positions from the literature is 0.152 cm-1 and our absolute intensities agree better than 10 per cent. The full line list is available from the CDS data base as well as at www.exomol.com.

  9. ExoMol line lists XVIII. The high temperature spectrum of VO.

    NASA Astrophysics Data System (ADS)

    McKemmish, Laura K.; Yurchenko, Sergei N.; Tennyson, Jonathan

    2016-08-01

    An accurate line list, VOMYT, of spectroscopic transitions is presented for hot VO. The 13 lowest electronic states are considered. Curves and couplings are based on initial ab initio electronic structure calculations and then tuned using available experimental data. Dipole moment curves, used to obtain transition intensities, are computed using high levels of theory (e.g. MRCI/aug-cc-pVQZ using state-specific or minimal-state CAS for dipole moments). This line list contains over 277 million transitions between almost 640,000 energy levels. It covers the wavelengths longer than 0.29 μm and includes all transitions from energy levels within the lowest nine electronic states which have energies less than 20,000 cm-1 to upper states within the lowest 13 electronic states which have energies below 50,000 cm-1. The line lists give significantly increased absorption at infrared wavelengths compared to currently available VO line lists. The full line lists is made available in electronic form via the CDS database and at www.exomol.com.

  10. Plasma etch challenges with new EUV lithography material introduction for patterning for MOL and BEOL

    NASA Astrophysics Data System (ADS)

    Lee, Changwoo; Nagabhirava, Bhaskar; Goss, Michael; Wang, Peng; Friddle, Phil; Schmitz, Stafan; Wu, Jian; Yang, Richard; Mignot, Yann; Rassoul, Nouradine; Hamieh, Bassem; Beique, Genevieve; Labonte, Andre; Labelle, Catherine; Arnold, John; Mucci, John

    2015-03-01

    As feature critical dimension (CD) shrinks towards and beyond the 7nm node, patterning techniques for optical lithography with double and triple exposure will be replaced by EUV patterning. EUV enables process and overlay improvement, as well as a potential cost reduction due to fewer wafer passes and masks required for patterning. However, the EUV lithography technique introduces newer types of resists that are thinner and softer compared to conventional 193nm resists currently being used. The main challenge is to find the key etch process parameters to improve the EUV resist selectivity, reduce LER and LWR, minimize line end shrink, improve tip-to-tip degradation, and avoid line wiggling while still enabling previous schemes such as trench-first-metal-hard-mask (TFMHM), self-aligned via (SAV) and self-aligned contact (SAC). In this paper, we will discuss some of the approaches that we have investigated to define the best etch process adjustments to enable EUV patterning. RF pulsing is one of the key parameters utilized to overcome most of the previously described challenges, and has also been coupled with stack optimization. This study will focus on RF pulsing (high vs. low frequency results) and bias control (RF frequency dependence). In particular, pulsing effects on resist morphology, selectivity and profile management will be reported, as well as the role of aspect ratio and etch chemistry on organic mask wiggling and collapse. This work was performed by the Research Alliance Teams at various IBM Research and Development Facilities.

  11. P. MULTOCIDA MEMBRANE PROTEOME ANALYSIS (POSTER PRESENTATION FOR THE AM. SOC. BIOCHEM. & MOL. BIOL. MEETING)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Commercial bacterins for the control of fowl cholera are comprised of P. multocida serotypes A:1, A:3, and A:4, which are the serotypes that are most often associated with outbreaks in poultry flocks. A membrane-associated protein fraction (cross-protective factor, CPF), comprised of 11 major prote...

  12. ExoMol line lists - VIII. A variationally computed line list for hot formaldehyde

    NASA Astrophysics Data System (ADS)

    Al-Refaie, Ahmed F.; Yachmenev, Andrey; Tennyson, Jonathan; Yurchenko, Sergei N.

    2015-04-01

    A computed line list for formaldehyde, H212C16O, applicable to temperatures up to T = 1500 K is presented. An empirical potential energy and ab initio dipole moment surfaces are used as the input to the nuclear motion program TROVE. The resulting line list, referred to as AYTY, contains 10.3 million rotational-vibrational states and around 10 billion transition frequencies. Each transition includes associated Einstein-A coefficients and absolute transition intensities, for wavenumbers below 10 000 cm-1 and rotational excitations up to J = 70. Room-temperature spectra are compared with laboratory measurements and data currently available in the HITRAN data base. These spectra show excellent agreement with experimental spectra and highlight the gaps and limitations of the HITRAN data. The full line list is available from the CDS data base as well as at www.exomol.com.

  13. VizieR Online Data Catalog: ExoMol line lists for HNO3 (Pavlyuchko+, 2015)

    NASA Astrophysics Data System (ADS)

    Pavlyuchko, A. I.; Yurchenko, S. N.; Tennyson, J.

    2015-05-01

    The data for each isotopologue are in two parts. The first, HNO3.states contains a list of rovibronic states. Each state is labelled with the total angular momentum, state degeneracy, total parity, vibrational quantum number, projection of the electronic, spin and total angular momenta. Each state has a unique number, which is the number of the row in which it appears in the file. This number is the means by which the state is related to the second part of the data system, the transitions files. Because of their size, the transitions are listed in 71 separate files, each containing all the transitions in a 100cm-1 wavenumber range. These and their contents are ordered by increasing frequency. The name of the file includes the lowest frequency in the range; thus the a-00500.dat file contains all the transitions in the frequency range 500-600cm-1. The transition files a-*.dat contain three columns: the reference number in the energy file of the upper state; that of the lower state; and the Einstein A coefficient of the transition. (3 data files).

  14. ExoMol molecular line lists - XIV. The rotation-vibration spectrum of hot SO2

    NASA Astrophysics Data System (ADS)

    Underwood, Daniel S.; Tennyson, Jonathan; Yurchenko, Sergei N.; Huang, Xinchuan; Schwenke, David W.; Lee, Timothy J.; Clausen, Sønnik; Fateev, Alexander

    2016-07-01

    Sulphur dioxide is well-known in the atmospheres of planets and satellites, where its presence is often associated with volcanism, and in circumstellar envelopes of young and evolved stars as well as the interstellar medium. This work presents a line list of 1.3 billion 32S16O2 vibration-rotation transitions computed using an empirically adjusted potential energy surface and an ab initio dipole moment surface. The list gives complete coverage up to 8000 cm-1 (wavelengths longer than 1.25 μm) for temperatures below 2000 K. Infrared absorption cross-sections are recorded at 300 and 500 C are used to validated the resulting ExoAmes line list. The line list is made available in electronic form as supplementary data to this article and at www.exomol.com.

  15. Seismic Monitoring at the Underground Nuclear Research Laboratory in Mol, Belgium - 12461

    SciTech Connect

    Areias, Lou

    2012-07-01

    Micro-seismic piezoelectric transmitters installed in the Boom Clay at HADES produce predominantly high frequency signals, above 5 kHz, which favour the generation of P waves. However, above 5 kHz shear (S) waves are not detected by the installation. Recent studies at HADES indicate that it is possible to detect S waves with the current setup when applying a low (5 kHz) cut-off filter. The results also show that S waves have frequencies mainly below 1 kHz, while P waves are detectable at all of the eight transmitted frequencies but show optimum resolution in the range of 7 to 23 kHz. Although the system offers great potential for monitoring the evolution of a geological disposal site, further improvements in signal generation and treatment are necessary. One of these includes the design and testing of a new S-wave source at HADES planned in the framework of the EC MoDeRn project (http://www.modern-fp7.eu/). The seismic installation at HADES continues to provide useful information on the changing properties of the Boom Clay in the near and far field around the PRACLAY gallery since its start of operation in 2006. In the future, the system will also monitor the PRACLAY heater experiment that will start in 2012 and go on for 10 years. So far, the results of long term seismic monitoring show that S waves contain frequencies mainly below 1 kHz. The P waves are detectable at all of the eight transmitted frequencies but show optimum resolution in the range of 7 to 23 kHz. To improve the signal-to-noise ratio and detection of S waves at HADES it is, therefore, necessary to apply a strong low-pass filter that matches the S-wave frequency content. Due to the different frequency ranges observed for the P and S waves, it is recommended to treat them separately. The evolution of both P and S wave velocities in the EDZ around the PRACLAY gallery show continued recovery since its construction in 2007. Modelling results of the variation in crack density obtained from the inversion of the modelled P-wave transmission velocities further confirm the recovery of the EDZ and the self-healing properties of the Boom Clay. (authors)

  16. VizieR Online Data Catalog: ExoMol line lists for CH4 (Yurchenko+, 2014)

    NASA Astrophysics Data System (ADS)

    Yurchenko, S. N.; Tennyson, J.

    2014-02-01

    The data are in two parts. The first, ch4_0-39.dat contains a list of 7,819,352 rovibrational states. Each state is labelled with: nine normal mode vibrational quantum numbers and the vibrational symmety; three rotational quantum numbers including the total angular momentum J and rotational symmetry; the total symmetry quantum number Gamma and the running number in the same (J,Gamma,Polyad) combination, where Polyad is a polyad number (see paper). In addition there are nine local mode vibrational numbers and the largest coefficient used to assign the state in question. Each rovibrational state has a unique number, which is the number of the row in which it appears in the file. This number is the means by which the state is related to the second part of the data system, the transitions files. The total degeneracy is also given to facilitate the intensity calculations. Because of their size, the transitions are listed in 120 separate files, each containing all the transitions in a 100cm-1 frequency range. These and their contents are ordered by increasing frequency. The name of the file includes the lowest frequency in the range; thus the a-00500.dat file contains all the transitions in the frequency range 500-600cm-1. The transition files contain three columns: the reference number in the energy file of the upper state; that of the lower state; and the Einstein A coefficient of the transition. The energy file and the transitions files are zipped, and need to be extracted before use. There is a Fortran 90 programme, s_10to10.f90 which may be used to generate synthetic spectra (see s_10to10.txt for details). Using this, it is possible to generate absorption or emission spectra in either 'stick' form or else cross-sections convoluted with a gaussian with the half-width at half maximum being specified by the user, or with a the temperature-dependent doppler half-width. Sample input files s*.inp for use with s10to10.f90 are supplied. (9 data files).

  17. Fe-Al layered double hydroxides in bromate reduction: Synthesis and reactivity.

    PubMed

    Chitrakar, Ramesh; Makita, Yoji; Sonoda, Akinari; Hirotsu, Takahiro

    2011-02-15

    This study presents a rare use of layered double hydroxides of Fe(II) and Al(III) (Fe-Al LDH), as reported for the first time for bromate removal from aqueous solutions. The Fe-Al LDH samples were prepared with Fe/Al molar ratios of 1-4 using a co-precipitation method at pH 7, with subsequent hydrothermal treatment at 120°C. The Fe-Al LDH (molar ratio of Fe/Al=1, 2) with a layered structure exhibited nearly complete removal of bromate from initial concentration of 100μmol/dm(3) at a wide pH range of 4.0-10.5 over a 2h reaction period; the residual bromate concentration in the solution was lower than the detection limit of 0.07μmol/dm(3) (9μg-BrO(3)(-)/dm(3)). During the reaction period, bromide was released into the solution via a reduction process. Reactivity of Fe-Al LDH with a Fe/Al molar ratio of 2 did not decrease the bromate reduction efficiency during 30days. PMID:21126742

  18. Nanostructured crystals of fluorite phases Sr{sub 1−x}R{sub x}F{sub 2+x} (R Are Rare Earth Elements) and their ordering: 10. Ordering under spontaneous crystallization and annealing of Sr{sub 1−x}R{sub x}F{sub 2+x} Alloys (R = Tb-Lu, Y) with 23.8–36.1 mol % RF{sub 3}

    SciTech Connect

    Sulyanova, E. A. Karimov, D. N.; Sulyanov, S. N.; Zhmurova, Z. I.; Golubev, A. M.; Sobolev, B. P.

    2015-01-15

    The products of spontaneous crystallization (at a cooling rate of ∼200 K/min) of Sr{sub 1−x}R{sub x}F{sub 2+x} melts in the homogeneity range of the fluorite phase have been investigated. Thirty-two irrational compositions with 23.8–36.1 mol % RF{sub 3} and eight rational Sr{sub 2}RF{sub 7} compositions are obtained. With respect to the RF{sub 3} content, these compositions form five groups: (1) Sr{sub 0.762}R{sub 0.238}F{sub 2.238} (23.8% RF{sub 3}), (2) Sr{sub 0.744}R{sub 0.256}F{sub 2.256} (25.6%), (3) Sr{sub 0.718}R{sub 0.282}F{sub 2.282} (28.2%), (4) Sr{sub 2}RF{sub 7} (33.3%), and (5) Sr{sub 0.639}R{sub 0.361}F{sub 2.361} (36.1%). R = Tb-Lu, Y for all groups. Quenching melts of group 5 with R = Tb, Dy, and Ho leads to the formation of ordered phases with the trigonal distortion of the rhβ-Na{sub 7}Zr{sub 6}F{sub 31} type, while for melts of group 5 with R = Lu, quenching yields a phase of the trigonal rhα′-Sr{sub 4}Lu{sub 3}F{sub 17} type. In group 5 with R = Y, Er, Tm, or Yb and in groups 1–4 with all REEs, fluorite phases are formed. Annealing at 900 ± 20°C for 96 h with subsequent cooling at a rate of ∼200 K/min expands the variety of ordered phases: a phase with a new r type of orthorhombic distortion is formed in group 1 with R = Lu, in group 2 with R = Tm or Lu, and in group 3 with R = Ho-Lu, Y; a t-Sr{sub 2}RF{sub 7} phase with tetragonal distortion is formed in group 4 with R = Tb-Er, Y; and a phase of trigonal rhα′ type is formed in group 5 with R = Y, Yb, or Lu. A fluorite phase arises in group 1 with R = Tb-Lu, Y as a result of quenching and annealing. The tendency to ordering becomes more pronounced with an increase in the RF{sub 3} content and REE atomic number. The annealing conditions do not provide equilibrium or the completely ordered state of all alloys.

  19. 31 CFR 10.4 - Eligibility to become an enrolled agent, enrolled retirement plan agent, or registered tax return...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... under the provisions of this part. (b) Enrollment as a retirement plan agent upon examination. The... any practitioner under the provisions of this part. (c) Designation as a registered tax return... practitioner under the provisions of this part. (d) Enrollment of former Internal Revenue......

  20. Reynolds numbers influence the directionality of self-propelled microjet engines in the 10-4 regime

    NASA Astrophysics Data System (ADS)

    Zhao, Guanjia; Nguyen, Nam-Trung; Pumera, Martin

    2013-07-01

    The motion directionality of self-propelled bubble-jet microengines is influenced by their velocities and/or viscosity of the media in which they move. The influence of the fuel concentration from 1 to 3 wt% of H2O2 in 0.5% steps and of the glycerol fraction from 0 to 64% in aqueous solution on the directionality of the microjets motions is examined systematically. We show that with decreasing Reynolds numbers of the system (that is, with increasing viscosity or decreasing velocity of the microjets), the directionality of the motion shifts from circular to linear motion. This translates to a shorter travel time towards a designated target for the microjets despite moving at a slower speed, since the movements are linear instead of circular. We show that such dependence of trajectories of microjets on Re is a general issue. This observation has a strong implication for the real-world applications of microjets.The motion directionality of self-propelled bubble-jet microengines is influenced by their velocities and/or viscosity of the media in which they move. The influence of the fuel concentration from 1 to 3 wt% of H2O2 in 0.5% steps and of the glycerol fraction from 0 to 64% in aqueous solution on the directionality of the microjets motions is examined systematically. We show that with decreasing Reynolds numbers of the system (that is, with increasing viscosity or decreasing velocity of the microjets), the directionality of the motion shifts from circular to linear motion. This translates to a shorter travel time towards a designated target for the microjets despite moving at a slower speed, since the movements are linear instead of circular. We show that such dependence of trajectories of microjets on Re is a general issue. This observation has a strong implication for the real-world applications of microjets. Electronic supplementary information (ESI) available: Videos S1-S4. See DOI: 10.1039/c3nr01891a

  1. Medical Laboratory Technician--Hematology, Serology, Blood Banking & Immunohematology, 10-4. Military Curriculum Materials for Vocational and Technical Education.

    ERIC Educational Resources Information Center

    Ohio State Univ., Columbus. National Center for Research in Vocational Education.

    This course, the third of three courses in the medical laboratory technician field adapted from military curriculum materials for use in vocational and technical education, was designed as a refresher course for student self-study and evaluation. It is suitable for use by advanced students or beginning students participating in a supervised…

  2. Non-enzymatic glucose biosensor based on hyperbranched pine-like gold nanostructure.

    PubMed

    Heli, H; Amirizadeh, O

    2016-06-01

    Hyperbranched pine-like gold nanostructure was electrodeposited on the polycrystalline gold surface at 0 mV (vs. AgCl) with the assistance of histidine as a soft template. The nanostructure was then applied as a highly sensitive nonenzymatic sensor for glucose. The catalytic activity and sensitivity of the gold nanostructure toward the electrooxidation of glucose was excellent without surface fouling and deterioration effects. The current related to the oxidation of glucose rapidly and linearly depended on its concentration with a sensitivity of 776.8 μA cm(-2)mmol(-1)dm(3), a detection limit of 3.39 μmol dm(-3) with a relative standard deviation of 2.32%. PMID:27040206

  3. Radiation-induced decomposition of trace amounts of 17 β-estradiol in water

    NASA Astrophysics Data System (ADS)

    Kimura, Atsushi; Taguchi, Mitsumasa; Arai, Hidehiko; Hiratsuka, Hiroshi; Namba, Hideki; Kojima, Takuji

    2004-03-01

    The radiation-induced decomposition of trace amounts of 17 β-estradiol (E2) in water was studied as a function of the dose of 60Co γ-rays. The rate constant of the reaction of the OH radicals with E2 was estimated to be 1.6×10 10 mol dm -3 s -1 by a comparison with the known rate constant for the reaction with phenol. Both E2 and E2-equivalent concentrations were estimated by LC-MS and ELISA, and decreased with an increase in γ-rays dose. E2 (1.8 nmol dm -3) in water was degraded almost completely by irradiations up to 10 Gy. The estrogen activity of the same sample solution still remained at a dose of 10 Gy, but decreased at 30 Gy to the lower than the threshold level of contamination to induce some estrogenic effects on the environmental ecology.

  4. The study of secondary effects in vibrational and hydrogen bonding properties of 2- and 3-ethynylpyridine and ethynylbenzene by IR spectroscopy.

    PubMed

    Vojta, Danijela; Matanović, Ivana; Kovačević, Goran; Baranović, Goran

    2014-11-11

    Weak hydrogen bonds formed by 2- and 3-ethynylpyridine and ethynylbenzene with trimethylphosphate and phenol were characterized by IR spectroscopy and DFT calculations (B3LYP/6-311++G(d, p)). The structure and stability of ethynylpyridines and ethynylbenzene in the gas phase and in the complexes with trimethylphosphate and phenol are discussed in terms of geometry and electronic charge redistribution. Anharmonic effects are taken into account when calculating vibrational wavenumbers of these systems what lead to partial improvement of agreement with experiment. The changes in the electronic charge distribution are behind the frequency shifts of the CC stretching in opposite direction depending on the role the ethyne molecule has in a hydrogen bonded complex (Δν̃=+9 cm(-1) in trimethylphosphate complexes, Δν̃=-3 cm(-1) in phenol complexes). The association constants were determined by keeping the concentrations of proton donors approximately constant and low enough to avoid self-association and the proton acceptors were present in excess. The values obtained for the association constants and enthalpy changes in C2Cl4 (for trimethylphosphate complexes K≈0.5-1.0 mol(-1)dm(3) and -ΔrH≈6-8 kJ mol(-1), for phenol complexes K≈20-40 mol(-1) dm3-ΔrH≈17-22 kJ mol(-1)) are in good agreement with literature data. PMID:24866088

  5. Drivers of summer oxygen depletion in the central North Sea

    NASA Astrophysics Data System (ADS)

    Queste, B. Y.; Fernand, L.; Jickells, T. D.; Heywood, K. J.; Hind, A. J.

    2015-06-01

    In stratified shelf seas, oxygen depletion beneath the thermocline is a result of a greater rate of biological oxygen demand than the rate of supply of oxygenated water. Suitably equipped gliders are uniquely placed to observe both the supply through the thermocline and the consumption of oxygen in the bottom layers. A Seaglider was deployed in the shallow (≈ 100 m) stratified North Sea in a region of known low oxygen during August 2011 to investigate the processes regulating supply and consumption of dissolved oxygen below the pycnocline. The first deployment of such a device in this area, it provided extremely high resolution observations, 316 profiles (every 16 min, vertical resolution of 1 m) of CTD, dissolved oxygen concentrations, backscatter and fluorescence during a three day deployment. The high temporal resolution observations revealed occasional small scale events that supply oxygenated water into the bottom layer at a rate of 2±1 μmol dm-3 day-1. Benthic and pelagic oxygen sinks, quantified through glider observations and past studies, indicate more gradual background consumption rates of 2.5±1 μmol dm-3 day-1. This budget revealed that the balance of oxygen supply and demand is in agreement with previous studies of the North Sea. However, the glider data show a net oxygen consumption rate of 2.8±0.3 μmol dm-3 day-1 indicating a localised or short-lived increase in oxygen consumption rates. This high rate of oxygen consumption is indicative of an unidentified oxygen sink. We propose that this elevated oxygen consumption is linked to localised depocentres and rapid remineralisation of resuspensded organic matter. The glider proved to be an excellent tool for monitoring shelf sea processes despite challenges to glider flight posed by high tidal velocities, shallow bathymetry, and very strong density gradients. The direct observation of these processes allows more up to date rates to be used in the development of ecosystem models.

  6. Role of radiolytically generated species in radiation induced polymerization of sodium p-styrene sulphonate (SSS) in aqueous solution: Steady state and pulse radiolysis study

    NASA Astrophysics Data System (ADS)

    Bhardwaj, Y. K.; Mohan, H.; Sabharwal, S.; Majali, A. B.

    2000-06-01

    Radiation induced polymerization of sodium p-styrene sulphonate (SSS) in aqueous solution has been investigated by steady state and pulse radiolysis techniques. Effect of dose, dose rate, monomer concentration, pH and ambient conditions on polymerization was investigated. The reactions of primary radicals of water radiolysis such as OH radical, e -aq, H atom, O rad - and some oxidizing radicals like N rad 3, Cl rad -2,Br rad -2, and reducing specie like CO rad -2 with SSS have also been investigated. SSS reacts with OH radical with a rate constant of 5.9×10 9 dm 3 mol -1s -1 at pH 6.3. The results indicate that ˜83% of OH radicals undergo electron transfer reaction resulting in a cation radical species while remaining ˜17% react via addition reaction. The hydrated electron reacts with SSS with a rate constant 1.3×10 10 dm 3 mol -1 s -1 to form an anion that undergoes fast protonation to form H-adduct at pH 6.3. At high pH (>10) the anion is able to transfer electron to methyl vilogen and p-nitro aceto phenone ( p-NAP) where as H-adduct is unable to transfer electron. At pH ˜1 H atom reaction with SSS is diffusion controlled with a rate constant of 5×10 9 dm 3 mol -1 s -1 and results in formation of H adduct. It was seen that anion reacts with solute an order faster than cation generated radiolytically indicating anionic initiation of polymerization of SSS. Molecular weight of the polymer formed by radiation polymerization, determined by viscosity measurement, are of the order of 10 7 and higher molecular weight polymers are obtained at lower dose rates. In presence of a crosslinking agent gelation of polymer is much faster than the monomer and a polymer concentration ˜20% is most efficiently crosslinked.

  7. 226Ra bioavailability to plants at the Urgeiriça uranium mill tailings site.

    PubMed

    Madruga, M J; Brogueira, A; Alberto, G; Cardoso, F

    2001-01-01

    Large amounts of solid wastes (tailings) resulting from the exploitation and treatment of uranium ore at the Urgeiriça mine (north of Portugal) have been accumulated in dams (tailing ponds). To reduce the dispersion of natural radionuclides into the environment, some dams were revegetated with eucalyptus (Eucalyptus globolus) and pines (Pinus pinea). Besides these plants, some shrubs (Cytisus spp.) are growing in some of the dams. The objective of this study is to determine the 226Ra bioavailability from uranium mill tailings by quantifying the total and available fraction of radium in the tailings and to estimate its transfer to plants growing on the tailing piles. Plant and tailing samples were randomly collected and the activity concentration of 226Ra in plants (aerial part and roots) and tailings was measured by gamma-spectrometry. The exchangeable fraction of radium in tailings was quantified using one single step extraction with 1 mol dm-3 ammonium acetate (pH = 7) or 1 mol dm-3 calcium chloride solutions. The results obtained for 226Ra uptake by plants show that 226Ra concentration ratios for eucalyptus and pines decrease at low 226Ra concentrations in the tailings and appear relatively constant at higher radium concentrations. For shrubs, the concentration ratios increase at higher 226Ra solid waste concentrations approaching a saturation value. Percentage values of 16.0 +/- 8.3 and 12.9 +/- 8.9, for the fraction of radium extracted from the tailings, using 1 mol dm-3 ammonium acetate or calcium chloride solutions, respectively, were obtained. The 226Ra concentration ratios determined on the basis of exchangeable radium are one order of magnitude higher than those based on total radium. It can be concluded that, at a 95% confidence level, more consistent 226Ra concentration ratios were obtained when calculated on the basis of available radium than when total radium was considered, for all the dams. PMID:11379070

  8. Synthesis, DNA binding and complex formation reactions of 3-amino-5,6-dimethyl-1,2,4-triazine with Pd(II) and some selected biorelevant ligands

    NASA Astrophysics Data System (ADS)

    Shoukry, Azza A.; Alghanmi, Reem M.

    2015-03-01

    With the purpose of studying the binding behavior of Pd(II) complexes with DNA as the main biological target, and their ability to penetrate reasonably into tumour cells and destroy their replication ability, Pd(ADT)Cl2 complex was synthesized and characterized, where ADT is 3-amino-5,6-dimethyl-1,2,4-triazine. Stoichiometry and stability constants of the complexes formed between various biologically relevant ligands (amino acids, amides, DNA constituents, and dicarboxylic acids) and [Pd(ADT)(H2O)2]2+ were investigated at 25 °C and at constant 0.1 mol dm-3 ionic strength. The concentration distribution diagrams of the various species formed are evaluated. Further investigation of the binding properties of the diaqua complex [Pd(ADT)(H2O)2]2+ with calf thymus DNA (CT-DNA) was investigated by UV-vis spectroscopy. The intrinsic binding constants (Kb) calculated from UV-vis absorption studies was calculated to be 2.00 × 103 mol dm-3. The calculated (Kb) value was found to be of lower magnitude than that of the classical intercalator EB (Ethidium bromide) (Kb = 1.23(±0.07) × 105 mol dm-3) suggesting an electrostatic and/or groove binding mode for the interaction with CT-DNA. Thermal denaturation has been systematically studied by spectrophotometric method and the calculated ΔTm was nearly 5 °C, supporting the electrostatic and/or groove binding mode for the interaction between the complex and CT-DNA

  9. Determination of enantiomeric purity of mandelonitrile with derivatized cyclodextrins in water

    NASA Astrophysics Data System (ADS)

    Hickel, Andrea; Gradnig, Günther; Schall, Michael; Zangger, Klaus; Griengl, Herfried

    1997-03-01

    A variety of derivatized cyclodextrins was used for the determination of the optical purity of mandelonitrile by 1H-NMR (nuclear magnetic resonance) spectroscopy in aqueous solution. Mandelonitrile was formed by the enzymatic reaction of benzaldehyde and HCN (or acetone cyanohydrine) with the hydroxynitrile lyase (Hnl) from Hevea brasiliensis (rubber tree). It turned out that the best separation was achieved with acetyl-β-cyclodextrin ( Kd = 12 dm 3 mol -1). A straightforward integration was possible if there was more than 5% of one of the enantiomers in the solution. Below this value, the results were not reproducible enough for quantitative analysis.

  10. Chemical properties and toxicity of soils contaminated by mining activity.

    PubMed

    Agnieszka, Baran; Tomasz, Czech; Jerzy, Wieczorek

    2014-09-01

    This research is aimed at assessing the total content and soluble forms of metals (zinc, lead and cadmium) and toxicity of soils subjected to strong human pressure associated with mining of zinc and lead ores. The research area lay in the neighbourhood of the Bolesław Mine and Metallurgical Plant in Bukowno (Poland). The study obtained total cadmium concentration between 0.29 and 51.91 mg, zinc between 7.90 and 3,614 mg, and that of lead between 28.4 and 6844 mg kg(-1) of soil d.m. The solubility of the heavy metals in 1 mol dm(-3) NH4NO3 was 1-49% for zinc, 5-45% for cadmium, and <1-10% for lead. In 1 mol HCl dm(-3), the solubility of the studied metals was much higher and obtained values depending on the collection site, from 45 to 92% for zinc, from 74 to 99%, and from 79 to 99% for lead. The lower solubility of the heavy metals in 1 mol dm(-3) NH4NO3 than 1 mol HCl dm(-3) is connected with that, the ammonium nitrate has low extraction power, and it is used in determining the bioavailable (active) form of heavy metals. Toxicity assessment of the soil samples was performed using two tests, Phytotoxkit and Microtox(®). Germination index values were between 22 and 75% for Sinapis alba, between 28 and 100% for Lepidium sativum, and between 10 and 28% for Sorghum saccharatum. Depending on the studied soil sample, Vibrio fischeri luminescence inhibition was 20-96%. The sensitivity of the test organisms formed the following series: S. saccharatum > S. alba = V. fischeri > L. sativum. Significant positive correlations (p ≤ 0.05) of the total and soluble contents of the metals with luminescence inhibition in V. fischeri and root growth inhibition in S. saccharatum were found. The general trend observed was an increase in metal toxicity measured by the biotest with increasing available metal contents in soils. All the soil samples were classified into toxicity class III, which means that they are toxic and present severe danger. Biotest are a good complement to

  11. Structural properties of aqueous metoprolol succinate solutions. Density, viscosity, and refractive index at 311 K

    NASA Astrophysics Data System (ADS)

    Deosarkar, S. D.; Kalyankar, T. M.

    2013-06-01

    Density, viscosity and refractive index of aqueous solutions of metoprolol succinate of different concentrations (0.005-0.05 mol dm-3) were measured at 38°C. Apparent molar volume of resultant solutions were calculated and fitted to the Masson's equation and apparent molar volume at infinite dilution was determined graphically. Viscosity data of solutions has been fitted to the Jone-Dole equation and viscosity A- and B-coefficients were determined graphically. Physicochemical data obtained were discussed in terms of molecular interactions.

  12. Experimental determination of Henry's law constant of perfluorooctanoic acid (PFOA) at 298 K by means of an inert-gas stripping method with a helical plate

    NASA Astrophysics Data System (ADS)

    Kutsuna, Shuzo; Hori, Hisao

    The Henry's law constant ( KH) of perfluorooctanoic acid (PFOA, C 7F 15C(O)OH) was determined at 298 K in aqueous sulfuric acid solutions and in aqueous sodium chloride and sulfuric acid mixtures by an inert-gas stripping method in which a helical plate was used to increase the residence time of the gas bubbles in the solutions. The partial pressures of C 7F 15C(O)OH in the purge gas ( PPFOA) were determined by means of Fourier-transform infrared spectroscopy. Time-courses of PPFOA and concentrations of PFOA in the test solutions ( CPFOA) differed from those typically obtained by an inert-gas stripping, indicating both the presence of C 7F 15C(O)OH aggregates, even at low concentrations of C 7F 15C(O)OH in aqueous sulfuric acid solutions, and the adsorption of gaseous C 7F 15C(O)OH on the walls of the experimental apparatus. We derived overall gas-to-water partition coefficients ( KH') by simulating the time-courses of PPFOA and CPFOA simultaneously to optimize parameters of the model relating to the partitioning, the aggregation, and the adsorption. The KH' value for 0.31 mol dm -3 sulfuric acid solutions at 298 K was determined at 3.8 ± 0.1 mol dm -3 atm -1. From the relationship between KH' and the ionic strength of aqueous sulfuric acid solutions, the KH values of C 7F 15C(O)OH at 298 K were determined at 9.9 ± 1.5 mol dm -3 atm -1 for p Ka = 2.8 and 5.0 ± 0.2 mol dm -3 atm -1 for p Ka = 1.3. The p Ka value of 1.3 seems to be most probable among the reported three values for C 7F 15C(O)OH, taking into account dependence of KH' on sulfuric acid concentrations for aqueous sodium chloride and sulfuric acid mixtures. Despite the low p Ka value, the relatively small KH of C 7F 15C(O)OH obtained at 298 K suggests a substantial partitioning of C 7F 15C(O)OH in air in the environment.

  13. mtsslSuite: In silico spin labelling, trilateration and distance-constrained rigid body docking in PyMOL

    NASA Astrophysics Data System (ADS)

    Hagelueken, Gregor; Abdullin, Dinar; Ward, Richard; Schiemann, Olav

    2013-10-01

    Nanometer distance measurements based on electron paramagnetic resonance methods in combination with site-directed spin labelling are powerful tools for the structural analysis of macromolecules. The software package mtsslSuite provides scientists with a set of tools for the translation of experimental distance distributions into structural information. The package is based on the previously published mtsslWizard software for in silico spin labelling. The mtsslSuite includes a new version of MtsslWizard that has improved performance and now includes additional types of spin labels. Moreover, it contains applications for the trilateration of paramagnetic centres in biomolecules and for rigid-body docking of subdomains of macromolecular complexes. The mtsslSuite is tested on a number of challenging test cases and its strengths and weaknesses are evaluated.

  14. Broad Temperature Pinning Study of 15 mol.% Zr-Added (Gd, Y)-Ba-Cu-O MOCVD Coated Conductors

    SciTech Connect

    Xu, AX; Khatri, N; Liu, YH; Majkic, G; Galstyan, E; Selvamanickam, V; Chen, YM; Lei, CH; Abraimov, D; Hu, XB; Jaroszynski, J; Larbalestier, D

    2015-06-01

    BaZrO3 (BZO) nanocolumns have long been shown to be very effective for raising the pinning force F-p of REBa2Cu3Ox (REBCO, where RE = rare earth) films at high temperatures and recently at low temperatures too. We have successfully incorporated a high density of BZO nanorods into metal organic chemical vapor deposited (MOCVD) REBCO coated conductors via Zr addition. We found that, compared to the 7.5% Zr-added coated conductor, dense BZO nanorod arrays in the 15% Zr-added conductor are effective over the whole temperature range from 77 K down to 4.2 K. We attribute the substantially enhanced J(c) at 30 K to the weak uncorrelated pinning as well as the strong correlated pinning. Meanwhile, by tripling the REBCO layer thickness to similar to 2.8 mu m, the engineering critical current density J(e) at 30 K exceeds J(e) of optimized Nb-Ti wires at 4.2 K.

  15. [Use of algarrobo (Prosopis chilensis (Mol) Stuntz) flour as protein and dietary fiber source in cookies and fried chips manufacture].

    PubMed

    Escobar, Berta; Estévez, Ana María; Fuentes, Carolina; Venegas, Daniela

    2009-06-01

    Limiting amino acids of the protein from chilean "algarrobo" are isoleucine, theronine and methionine/cyteine. Cereals and legume blends allow to improve the amino acid balance, since legume have more lysine, and cereals are richer in sulphur amino acids. Due to the nutritional interest of "algarrobo" cotyledons, the use of "algarrobo cotyledon" flour (ACF) in sweet and salty snack manufacture was evaluated. Cookies and fried salty chips with 0%, 10% and 20% ACF were prepared. Flours were analyzed for color, particle size, moisture, proximate composition, available lysine, and soluble, insoluble and total dietary fiber. Cookies and chips were analyzed for the same characteristics (except for particle size); besides there were determined water activity, weight and size of the units, and also, the caloric value was computed. Sensory quality and acceptance of both products were evaluated. It is noticeable the high amount of protein, lipids, ash, crude fiber (63.6; 10.2; 4.3 and 4.2 g/100 g dmb, respectively), available lysine (62.4 mg/g protein) and total dietary fiber (24.2 g/100 g dmb) of ACF. Both, cookies and chips with ACF, showed a significant increase in the amount of protein, lipids, ash, crude fiber and, available lysine (from 15.5 to 19,3 and from 20.3 a 29.6 mg lisina/g protein, respectively), and total dietary fiber (from 1.39 to 2.80 and from 1.60 a 5.60 g/100 g dmb, respectively). All of the cookies trials were well accepted ("I like it very much"); chips with 10% of AFC showed the highest acceptance ("I like it"). It can be concluded that the use of ACF in cookies and chips manufacture increases the contribution of available lysine; their protein and dietary fiber content, improving the soluble/insoluble fiber ratio, without affect neither their physical nor their sensory acceptance. PMID:19719017

  16. The Potential of Algarrobo ( Prosopis chilensis (Mol.) Stuntz) for Regeneration of Desertified Soils: Assessing Seed Germination Under Saline Conditions

    NASA Astrophysics Data System (ADS)

    Westphal, Claus; Gachón, Paloma; Bravo, Jaime; Navarrete, Carlos; Salas, Carlos; Ibáñez, Cristian

    2015-07-01

    Due to their multipurpose use, leguminous trees are desirable for the restoration of degraded ecosystems. Our aim was to investigate seed germination of the leguminous tree Prosopis chilensis in response to salinity, one of the major abiotic challenges of desertified soils. Germination percentages of seed from 12 wild P. chilensis populations were studied. Treatments included four aqueous NaCl concentrations (150, 300, 450, and 600 mM). In each population, the highest germination percentage was seen using distilled water (control), followed closely by 150 mM NaCl. At 300 mM NaCl or higher salt concentration, germination was progressively inhibited attaining the lowest value at 450 mM NaCl, while at 600 mM NaCl germination remained reduced but with large variation among group of samples. These results allowed us to allocate the 12 groups from where seeds were collected into three classes. First, the seeds from Huanta-Rivadavia showed the lowest percent germination for each salt condition. The second group was composed of moderately salt-tolerant seeds with 75 % germination at 300 mM NaCl, followed by 50 % germination at 450 mM NaCl and 30 % germination at 600 mM NaCl. The third group from Maitencillo and Rapel areas was the most salt tolerant with an impressive seed germination level of 97 % at 300 mM NaCl, 82 % at 450 mM NaCl, and 42 % at 600 mM NaCl. Our results demonstrate that P. chilensis seeds from these latter localities have an increased germination capability under saline stress, confirming that P. chilensis is an appropriate species to rehabilitate desertified soils.

  17. VizieR Online Data Catalog: ExoMol line lists for H216O2 (Al-Refaie+, 2016)

    NASA Astrophysics Data System (ADS)

    Al-Refaie, A. F.; Polyansky, O. L.; Tennyson, J.; Yurchenko, S. N.

    2016-06-01

    The data are in two parts. The first, h2o20-85.dat contains a list of 7,560,352 rovibrational states. Each state is labelled with: six normal mode vibrational quantum numbers the torsional symmetry number (tau) and the vibrational symmetry; three rotational quantum numbers including the total angular momentum J and rotational symmetry; the total symmetry quantum number Gamma and the running number in the same J,Gamma block. In addition there are six local mode vibrational numbers and the largest coefficient used to assign the state in question. Each rovibrational state has a unique number, which is the number of the row in which it appears in the file. This number is the means by which the state is related to the second part of the data system, the transitions files. The total degeneracy is also given to facilitate the intensity calculations. Because of their size, the transitions are listed in 60 separate files, each containing all the transitions in a 100cm-1 frequency range. These and their contents are ordered by increasing frequency. The name of the file includes the lowest frequency in the range; thus the a-0500.dat file contains all the transitions in the frequency range 500-600cm-1. The transition files contain three columns: the reference number in the energy file of the upper state; that of the lower state; and the Einstein A coefficient of the transition. The energy file and the transitions files are zipped, and need to be extracted before use. There is a Fortran 90 programme, s_APTY.f90 which may be used to generate synthetic spectra (see s_APTY.txt for details). Using this, it is possible to generate absorption or emission spectra in either 'stick' form or else cross-sections convoluted with a gaussian with the half-width at half maximum being specified by the user, or with a the temperature-dependent doppler half-width. Sample input files s*.inp for use with sAPTY.f90 are supplied. (10 data files).

  18. VizieR Online Data Catalog: NIR survey of Spitzer YSOs in Orion Mol. Cloud (Kounkel+, 2016)

    NASA Astrophysics Data System (ADS)

    Kounkel, M.; Megeath, S. T.; Poteet, C. A.; Fischer, W. J.; Hartmann, L.

    2016-06-01

    As part of program GO 11548, 87 orbits of HST observations were successfully executed with the NICMOS camera in 2008 August and September. The remaining protostars in the target catalog were observed in 126 orbits obtained between 2009 August and 2010 December with WFC3. A total of five nights of observations were obtained at the NASA InfraRed Telescope Facility (IRTF) with the NSFCAM2 camera in the L' band, centered at 3.76um. (2 data files).

  19. ExoMol molecular line lists - XVI. The rotation-vibration spectrum of hot H2S

    NASA Astrophysics Data System (ADS)

    Azzam, Ala'a. A. A.; Tennyson, Jonathan; Yurchenko, Sergei N.; Naumenko, Olga V.

    2016-08-01

    This work presents the AYT2 line list: a comprehensive list of 114 million $^{1}$H$_2$$^{32}$S vibration-rotation transitions computed using an empirically-adjusted potential energy surface and an {\\it ab initio} dipole moment surface. The line list gives complete coverage up to 11000 \\cm\\ (wavelengths longer than 0.91 $\\mu$m) for temperatures up to 2000 K. Room temperature spectra can be simulated up to 20000 \\cm\\ (0.5 $\\mu$m) but the predictions at visible wavelengths are less reliable. AYT2 is made available in electronic form as supplementary data to this article and at \\url{www.exomol.com}.

  20. Observation des cycles enzymatiques des ADN topoisomérases par micromanipulation de molécules individuelles

    NASA Astrophysics Data System (ADS)

    Strick, Terence R.; Charvin, Gilles; Dekker, Nynke H.; Allemand, Jean-François; Bensimon, David; Croquette, Vincent

    In this article, we describe single-molecule assays using magnetic traps and we applied these assays to topoisomerase enzymes which unwind and disentangle DNA molecules. First, the elasticity of single DNA molecule is characterized using the magnetic trap. We show that a twisting constraint may be easily applied and that its effect upon DNA may be measured accurately. Then we describe how the topoisomerase activity may be observed at the single-molecule level giving direct access to the important biological parameters of the enzyme such as velocity and processivity. Furthermore, individual cycles of unwinding can be observed in real time. This permits an accurate characterization of the enzyme's biochemical cycle. The data treatment required to identify and analyze individual topoisomerization cycles will be presented in detail. This analysis is applicable to a wide variety of molecular motors. To cite this article: T.R. Strick et al., C. R. Physique 3 (2002) 595-618.

  1. KEY COMPARISON: International comparison CCQM-K51: Carbon monoxide (CO) in nitrogen (5 µmol mol-1)

    NASA Astrophysics Data System (ADS)

    Botha, Angelique; Janse van Rensburg, Mellisa; Tshilongo, James; Leshabane, Nompumelelo; Ntsasa, Napo; Kato, Kenji; Matsumoto, Nobuhiro; Stummer, Volker; Konopelko, L. A.; Kustikov, Y. A.; Pankratov, V. V.; Vasserman, I. I.; Zavyalov, C. V.; Gromova, E. V.; Uprichard, Ian; Vargha, Gergely; Maruyama, M.; Heine, Hans-Joachim; Rangel Murillo, Francisco; Serrano Caballero, Victor M.; Pérez Castorena, Alejandro; Mace, Tatiana; Guenther, Franklin; Miller, Walter; Rojo, Andrés; Fernández, Teresa; Cieciora, Dariusz; Cunha, Valnei S.; Ribeiro, Claudia C.; Augusto, Cristiane R.; Qiao, Han; Zhou, Zeyi; Smeulders, Damian; Gerboles, Michel; Kapus, Matej; Wessel, Rob M.; Dias, Florbela; Baptista, Gonçalo; Gupta, Prabhat K.; Johri, P.; Laongsri, Bunthoon; Sinweeruthai, Ratirat; Niederhauser, Bernhard; Ackermann, Andreas; Froehlich, Marina; Wolf, Andreas; Lee, Jeongsoon; Musil, Stanislav; Valkova, Miroslava; Walden, Jari; Laurila, Sisko

    2010-01-01

    The first key comparison on carbon monoxide (CO) in nitrogen dates back to 1992 (CCQM-K1a). It was one of the first types of gas mixtures that were used in an international key comparison. Since then, numerous national metrology institutes (NMIs) have been setting up facilities for gas analysis, and have developed claims for their Calibration and Measurement Capabilities (CMCs) for these mixtures. Furthermore, in the April 2005 meeting of the CCQM (Consultative Committee for Amount of Substance) Gas Analysis Working Group, a policy was proposed to repeat key comparisons for stable mixtures every 10 years. This comparison was performed in line with the policy proposal and provided an opportunity for NMIs that could not participate in the previous comparison. NMISA from South Africa acted as the pilot laboratory. Of the 25 participating laboratories, 19 (76%) showed satisfactory degrees of equivalence to the gravimetric reference value. The results show that the CO concentration is not influenced by the measurement method used, and from this it may be concluded that the pure CO, used to prepare the gas mixtures, was not 13C-isotope depleted. This was confirmed by the isotope ratio analysis carried out by KRISS on a 1% mixture of CO in nitrogen, obtained from the NMISA. There is no indication of positive or negative bias in the gravimetric reference value, as the results from the different laboratories are evenly distributed on both sides of the key comparison reference value. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (MRA).

  2. Threshold Photoelectron Photoion Coincidence (TPEPICO) Studies. The Road to ± 0.1 kJ/mol Thermochemistry

    SciTech Connect

    Baer, Tomas

    2013-10-14

    The threshold photoelectron photoion coincidence (TPEPICO) technique is utilized to investigate the dissociation dynamics and thermochemistry of energy selected medium to large organic molecular ions. The reactions include parallel and consecutive steps that are modeled with the statistical theory in order to extract dissociation onsets for multiple dissociation paths. These studies are carried out with the aid of molecular orbital calculations of both ions and the transition states connecting the ion structure to their products. The results of these investigations yield accurate heats of formation of ions, free radicals, and stable molecules. In addition, they provide information about the potential energy surface that governs the dissociation process. Isomerization reactions prior to dissociation are readily inferred from the TPEPICO data.

  3. The Potential of Algarrobo (Prosopis chilensis (Mol.) Stuntz) for Regeneration of Desertified Soils: Assessing Seed Germination Under Saline Conditions.

    PubMed

    Westphal, Claus; Gachón, Paloma; Bravo, Jaime; Navarrete, Carlos; Salas, Carlos; Ibáñez, Cristian

    2015-07-01

    Due to their multipurpose use, leguminous trees are desirable for the restoration of degraded ecosystems. Our aim was to investigate seed germination of the leguminous tree Prosopis chilensis in response to salinity, one of the major abiotic challenges of desertified soils. Germination percentages of seed from 12 wild P. chilensis populations were studied. Treatments included four aqueous NaCl concentrations (150, 300, 450, and 600 mM). In each population, the highest germination percentage was seen using distilled water (control), followed closely by 150 mM NaCl. At 300 mM NaCl or higher salt concentration, germination was progressively inhibited attaining the lowest value at 450 mM NaCl, while at 600 mM NaCl germination remained reduced but with large variation among group of samples. These results allowed us to allocate the 12 groups from where seeds were collected into three classes. First, the seeds from Huanta-Rivadavia showed the lowest percent germination for each salt condition. The second group was composed of moderately salt-tolerant seeds with 75% germination at 300 mM NaCl, followed by 50% germination at 450 mM NaCl and 30% germination at 600 mM NaCl. The third group from Maitencillo and Rapel areas was the most salt tolerant with an impressive seed germination level of 97% at 300 mM NaCl, 82 % at 450 mM NaCl, and 42 % at 600 mM NaCl. Our results demonstrate that P. chilensis seeds from these latter localities have an increased germination capability under saline stress, confirming that P. chilensis is an appropriate species to rehabilitate desertified soils. PMID:25894272

  4. ExoMol molecular line lists - XVI. The rotation-vibration spectrum of hot H2S

    NASA Astrophysics Data System (ADS)

    Azzam, Ala'a. A. A.; Tennyson, Jonathan; Yurchenko, Sergei N.; Naumenko, Olga V.

    2016-08-01

    This work presents the AYT2 line list: a comprehensive list of 115 million 1H232S vibration-rotation transitions computed using an empirically adjusted potential energy surface and an ab initio dipole moment surface. The line list gives complete coverage up to 11 000 cm-1 (wavelengths longer than 0.91 μm) for temperatures up to 2000 K. Room temperature spectra can be simulated up to 20 000 cm-1 (0.5 μm) but the predictions at visible wavelengths are less reliable. AYT2 is made available in electronic form as supplementary data to this paper at www.exomol.com.

  5. ExoMol line lists - VII. The rotation-vibration spectrum of phosphine up to 1500 K

    NASA Astrophysics Data System (ADS)

    Sousa-Silva, Clara; Al-Refaie, Ahmed F.; Tennyson, Jonathan; Yurchenko, Sergei N.

    2015-01-01

    A comprehensive hot line list is calculated for 31PH3 in its ground electronic state. This line list, called SAlTY, contains almost 16.8 billion transitions between 7.5 million energy levels and it is suitable for simulating spectra up to temperatures of 1500 K. It covers wavelengths longer than 1 μm and includes all transitions to upper states with energies below hc × 18 000 cm-1 and rotational excitation up to J = 46. The line list is computed by variational solution of the Schrödinger equation for the rotation-vibration motion employing the nuclear-motion program TROVE. A previously reported ab initio dipole moment surface is used as well as an updated `spectroscopic' potential energy surface, obtained by refining an existing ab initio surface through least-squares fitting to the experimentally derived energies. Detailed comparisons with other available sources of phosphine transitions confirms SAlTY's accuracy and illustrates the incompleteness of previous experimental and theoretical compilations for temperatures above 300 K. Atmospheric models are expected to severely underestimate the abundance of phosphine in disequilibrium environments, and it is predicted that phosphine will be detectable in the upper troposphere of many substellar objects. This list is suitable for modelling atmospheres of many astrophysical environments, namely carbon stars, Y dwarfs, T dwarfs, hot Jupiters and Solar system gas giant planets. It is available in full from the Strasbourg data centre, CDS, and at www.exomol.com.

  6. ExoMol line lists - IV. The rotation-vibration spectrum of methane up to 1500 K

    NASA Astrophysics Data System (ADS)

    Yurchenko, Sergei N.; Tennyson, Jonathan

    2014-05-01

    A new hot line list is calculated for 12CH4 in its ground electronic state. This line list, called 10to10, contains 9.8 billion transitions and should be complete for temperatures up to 1500 K. It covers the wavelengths longer than 1 μm and includes all transitions to upper states with energies below hc · 18 000 cm-1 and rotational excitation up to J = 39. The line list is computed using the eigenvalues and eigenfunctions of CH4 obtained by variational solution of the Schrödinger equation for the rotation-vibration motion of nuclei employing program TROVE and a new `spectroscopic' potential energy surface (PES) obtained by refining an ab initio PES (CCSD(T)-F12c/aug-cc-pVQZ) through least-squares fitting to the experimentally derived energies with J = 0-4 and a previously reported ab initio dipole moment surface (CCSD(T)-F12c/aug-cc-pVTZ). Detailed comparisons with other available sources of methane transitions including HITRAN, experimental compilations and other theoretical line lists show that these sources lack transitions both higher temperatures and near-infrared wavelengths. The 10to10 line list is suitable for modelling atmospheres of cool stars and exoplanets. It is available from the CDS data base as well as at www.exomol.com.

  7. VizieR Online Data Catalog: ExoMol line lists for formaldehyde H2CO (Al-Refaie+,

    NASA Astrophysics Data System (ADS)

    Al-Refaie, A. F.; Yachmenev, A.; Tennyson, J.; Yurchenko, S. N.

    2015-01-01

    The data are in two parts. The first, h2co_0-70.dat contains a list of 10,296,998 rovibrational states. Each state is labelled with: 6 normal mode vibrational quantum numbers, and the vibrational symmetry; three rotational quantum numbers including the total angular momentum J, the projection of J in the z-axis K,rotational symmetry and the total symmetry quantum number Gamma In addition there are six local mode vibrational numbers and the largest coeffecient used to assign the state in question. Each rovibrational state has a unique number, which is the number of the row in which it appears in the file. This number is the means by which the state is related to the second part of the data system, the transitions files. The total degeneracy is also given to facilitate the intensity calculations. Because of their size, the transitions are listed in 100 separate files, each containing all the transitions in a 100cm-1 frequency range. These and their contents are ordered by increasing frequency. The name of the file includes the lowest frequency in the range; thus the a-00500.dat file contains all the transitions in the frequency range 500-600cm-1. The transition files contain three columns: the reference number in the energy file of the upper state; that of the lower state; and the Einstein A coefficient of the transition. The energy file and the transitions files are zipped, and need to be extracted before use. There is a Fortran 90 programme, s_AYTY.f90 which may be used to generate synthetic spectra (see s_AYTY.txt for details). Using this, it is possible to generate absorption or emission spectra in either 'stick' form or else cross-sections convoluted with a gaussian with the half-width at half maximum being specified by the user, or with a the temperature-dependent doppler half-width. Sample input files s*.inp for use with sSAlTY.f90 are supplied. (9 data files).

  8. Protein adsorption behaviors onto photocatalytic Ti(IV)-doped calcium hydroxyapatite particles.

    PubMed

    Kandori, Kazuhiko; Kuroda, Tomohiko; Wakamura, Masato

    2011-10-15

    The fundamental experiments on the adsorption behaviors of proteins onto photocatalytic Ti(4+)-doped calcium hydroxyapatite (TiHap) particles were examined comparing to those onto the calcium hydroxyapatite (CaHap) and commercially available typical titanium oxide (TiO(2)) photocatalyst (TKP-101). The heat treated TiHap and CaHap particles were also used after treated these particles at 650°C for 1h (abbreviated as TiHap650 and CaHap650, respectively). All the adsorption isotherms of bovine serum albumin (BSA), myoglobin (MGB) and lysozyme (LSZ) from 1×10(-4)mol/dm(3) KCl solution were the Langmuirian type. The saturated amounts of adsorbed BSA (n(s)(BSA)) for the CaHap650 particles was higher than that for CaHap. Similar results were observed for TiHap and TiHap650. The adsorption of LSZ exhibited the same result of BSA, while the saturated amounts of adsorbed LSZ (n(s)(LSZ)) value on the TiHap were much higher than CaHap. However, the saturated amounts of adsorbed MGB (n(s)(MGB)) are almost equal to those for the CaHap and TiHap nevertheless whether these particles were heat treated at 650°C or not. The TKP-101 exhibited extremely small adsorption capacity of all proteins due to its small particle size of ca. 4nm in diameter. The independence of the n(s)(MGB) value on the zeta potential (zp) of the particles was explained by the electrostatical neutrality of MGB molecules. On the other hand, the n(s)(LSZ) values were increased with increase in the negative zp of the particles. This fact was explained by increasing the electrostatic attractive forces between negatively charged particles and positively charged LSZ. However, the n(s)(BSA) values exhibit maxima for the heat treated TiHap650 and CaHap650 particles. This result was interpreted to the formation of β-TCP crystal phase by the heat treatment. The produced Ca(2+) ions by dissolution from β-TCP phase may exert as binders between BSA and surfaces of the heat treated particles. PMID:21724376

  9. A search for temperature induced time-dependent structural transitions in 10mol%Sc2O3–1mol%CeO2–ZrO2 and 8mol%Y2O3–ZrO2 electrolyte ceramics

    SciTech Connect

    Chen, Yan; Orlovskaya, Nina; Payzant, E. Andrew; Graule, Thomas; Kuebler, Jakob

    2014-11-08

    Both Sc2O3–CeO2-stabilized-ZrO2 (SCSZ) and Y2O3-stabilized-ZrO2 (YSZ) show similar Young's modulus damping at 175–400 °C and 200–400 °C, respectively, by impulse excitation acoustic technique. The phase transition in SCSZ is considered responsible for the damping; however for YSZ, such a phase transition has never been reported. To clarify the relation of damping and structural transition in these two materials, the time-dependent high temperature stabilities are studied by in situ X-ray diffraction, neutron diffraction and Raman scattering during long-term annealing of SCSZ at 350 °C and YSZ at 275 °C. The cubic-to-rhombohedral transition in SCSZ is detected. However, the existence of t' phase in YSZ raw powders is confirmed without significant changes of the cubic structure during isothermal annealing. It is concluded that the phase transition contributes to the Young's modulus damping in SCSZ, while the structural transition is excluded from the reason for damping in YSZ.

  10. A search for temperature induced time-dependent structural transitions in 10mol%Sc2O3–1mol%CeO2–ZrO2 and 8mol%Y2O3–ZrO2 electrolyte ceramics

    DOE PAGESBeta

    Chen, Yan; Orlovskaya, Nina; Payzant, E. Andrew; Graule, Thomas; Kuebler, Jakob

    2014-11-08

    Both Sc2O3–CeO2-stabilized-ZrO2 (SCSZ) and Y2O3-stabilized-ZrO2 (YSZ) show similar Young's modulus damping at 175–400 °C and 200–400 °C, respectively, by impulse excitation acoustic technique. The phase transition in SCSZ is considered responsible for the damping; however for YSZ, such a phase transition has never been reported. To clarify the relation of damping and structural transition in these two materials, the time-dependent high temperature stabilities are studied by in situ X-ray diffraction, neutron diffraction and Raman scattering during long-term annealing of SCSZ at 350 °C and YSZ at 275 °C. The cubic-to-rhombohedral transition in SCSZ is detected. However, the existence of t'more » phase in YSZ raw powders is confirmed without significant changes of the cubic structure during isothermal annealing. It is concluded that the phase transition contributes to the Young's modulus damping in SCSZ, while the structural transition is excluded from the reason for damping in YSZ.« less

  11. The study of hydrogen bonding and π⋯π interactions in phenol⋯ethynylbenzene complex by IR spectroscopy.

    PubMed

    Vojta, Danijela; Vazdar, Mario

    2014-11-11

    Weak hydrogen bonds between phenol and ethynylbenzene in tetrachloroethene were explored by using FTIR spectroscopy. Association constants (Kc) were determined by high dilution method at two temperatures, 20°C and 26°C, and they are, respectively, 0.54±0.09 mol(-1) dm3 and 0.36±0.08 mol(-1) dm3. The position of ethynylbenzene stretching band, when in hydrogen bonding complex with phenol (CC⋯), is proposed to be governed by the interplay of OH⋯π (CC moiety or phenyl ring of ethynylbenzene) and π⋯π (phenyl ring of phenol⋯CC moiety or phenyl ring of ethynylbenzene) interactions. This conclusion is supported by the findings on the complex between ethanol and ethynylbenzene; in the latter, CC⋯ stretching band is shifted to the higher wavenumbers, as expected when ethynylbenzene interacts with hydrogen bond donor. Geometries and energies of the presumed complexes, as well as their vibrational spectra, are predicted by using ab initio calculations. The spectroscopic and thermodynamic data obtained here offer the missing pieces in the present picture of migration of H-atom of phenol OH group between competing hydrogen bond accepting centers on ethynylbenzene. PMID:24845872

  12. Comparative assessment of the methods for exchangeable acidity measuring

    NASA Astrophysics Data System (ADS)

    Vanchikova, E. V.; Shamrikova, E. V.; Bespyatykh, N. V.; Zaboeva, G. A.; Bobrova, Yu. I.; Kyz"yurova, E. V.; Grishchenko, N. V.

    2016-05-01

    A comparative assessment of the results of measuring the exchangeable acidity and its components by different methods was performed for the main mineral genetic horizons of texturally-differentiated gleyed and nongleyed soddy-podzolic and gley-podzolic soils of the Komi Republic. It was shown that the contents of all the components of exchangeable soil acidity determined by the Russian method (with potassium chloride solution as extractant, c(KCl) = 1 mol/dm3) were significantly higher than those obtained by the international method (with barium chloride solution as extractant, c(BaCl2) = 0.1 mol/dm3). The error of the estimate of the concentration of H+ ions extracted with barium chloride solution equaled 100%, and this allowed only qualitative description of this component of the soil acidity. In the case of the extraction with potassium chloride, the error of measurements was 50%. It was also shown that the use of potentiometric titration suggested by the Russian method overestimates the results of soil acidity measurement caused by the exchangeable metal ions (Al(III), Fe(III), and Mn(II)) in comparison with the atomic emission method.

  13. Catalytic behavior of a palladium doped binder free paper based cobalt electrode in electroreduction of hydrogen peroxide

    NASA Astrophysics Data System (ADS)

    Zhang, Dongming; Ye, Ke; Cao, Dianxue; Yin, Jinling; Cheng, Kui; Wang, Bin; Xu, Yang; Wang, Guiling

    2015-01-01

    A piece of flexible and conductive A4 paper is prepared by coating a layer of graphite with a normal 8B pencil. Then, Co nano-plates and Pd are assembled by a simple electrodeposition and chemical-reduction methods on the surface of the electrified paper, respectively. The as-prepared paper substrate/graphite-Co film-Pd (PG-CoPd) electrode is characterized by scanning electron microscopy equipped with energy dispersive X-ray spectrometer, transmission electron microscope and X-ray diffractometer. The catalytic activity of the PG-CoPd electrode for H2O2 electroreduction is investigated by means of cyclic voltammetry and chronoamperometry. The preparation process of the PG-CoPd electrode does not use any binder and it exhibits a three dimensional (3D) nano structure, high stability and good electric conductivity. The mass of the Pd in PG-CoPd is about 0.0535 mg cm-2 and the reduction current density reaches to -4.30 A cm-2 mg-1 in 1 mol dm-3 NaOH and 1.4 mol dm-3 H2O2 at -0.5 V, which is higher than our previous reports of Au/Pd modified Co electrode.

  14. In situ monitoring of pH titration by Raman spectroscopy

    NASA Astrophysics Data System (ADS)

    Elbagerma, M. A.; Azimi, Gholamhassan; Edwards, H. G. M.; Alajtal, A. I.; Scowen, I. J.

    2010-05-01

    Molecular speciation of organic compounds in solution is essential for the understanding of ionic complexation. The Raman technique was chosen because it allows the identification of compounds in different states, and it can give information about the molecular geometry from the analysis of the vibrational spectra. The effect of pH on organic compounds can give information about the ionisation of molecule species. In this study the ionisation steps of salicylic acid and paracetamol have been studied by means of potentiometry coupled with Raman spectroscopy at 30.0 °C in a solution of ionic strength 0.96 mol dm -3 (KNO 3) and 0.04 mol dm -3 (HNO 3). The protonation and deprotonation behaviour of the molecules were studied in different pH regions. The abundance of the three different species in the Raman spectra of aqueous salicylic acid have been identified satisfactorily, characterised, and determined by numeric treatment of the data using a multiwavelength curve-fitting program and confirmed with the observed spectral information.

  15. Preparation of Mg-vermiculite nanoparticles using potassium persulfate treatment.

    PubMed

    Matĕjka, Vlastimil; Supová-Krístková, Monika; Kratosvá, Gabriela; Valásková, Marta

    2006-08-01

    Delamination/exfoliation process of the Mg-vermiculite (Letovice, Czech Republic), particles with size less than 5 microm, was studied after potassium persulfate treatment and compared with known method utilized hydrogen peroxide treatment. X-ray powder diffraction (XRPD) patterns showed that treatment of Mg-vermiculite with different molar concentration of potassium persulfate: c = 0.02, 0.04, and 0.08 mol x dm(-3) at the temperature 60 degrees C for 2 hr caused reduction of relative intensity (I(rel.)) of the basal 001 diffraction to the 15%, 9%, and 4%, respectively, compared to intensity of 001 diffraction of untreated Mg-vermiculite (I(rel.) = 100%). On the other hand I(rel.) of the 001 diffraction of Mg-vermiculite after treatment with 30% and 50% (c = 9.8 and 17.4 mol x dm(-3)) hydrogen peroxide at the 60 degrees C for 2 hr decreased only to I(rel.) = 36% and 32%, respectively. Atomic Force Microscopy (AFM) and Scanning Electron Microscopy (SEM) verified effect of potassium persulfate treatment on structure degradation which is connected with higher degree of delamination/exfoliation of the particles and their cracking into nano-sized particles. PMID:17037860

  16. Vitamin E analogue Trolox C. E.s.r. and pulse-radiolysis studies of free-radical reactions.

    PubMed Central

    Davies, M J; Forni, L G; Willson, R L

    1988-01-01

    The reactions between Trolox C, a water-soluble vitamin E analogue, and several oxidizing free radicals including the hydroxyl radical and various peroxy radicals were examined by using the pulse-radiolysis technique. The results demonstrate that Trolox C may undergo rapid one-electron-transfer reactions as well as hydrogen-transfer processes; the resulting phenoxyl radical is shown to be relatively stable, in common with the phenoxyl radical derived from vitamin E. The reactions between the Trolox C phenoxyl radical and a variety of biologically relevant reducing compounds were examined by using both pulse radiolysis and e.s.r. The results demonstrate that the Trolox C phenoxyl radical is readily repaired by ascorbate (k = 8.3 x 10(6) dm3.mol-1.s-1) and certain thiols (k less than 10(5) dm3.mol-1.s-1) but not by urate, NADH or propyl gallate. Evidence from e.s.r. studies indicates that thiol-containing compounds may also enter into similar repair reactions with the alpha-tocopherol phenoxyl radical. Kinetic evidence is presented that suggests that Trolox C may 'repair' proteins that have been oxidized by free radicals. PMID:2849418

  17. Electrochemical characterisation of activated carbon particles used in redox flow battery electrodes

    NASA Astrophysics Data System (ADS)

    Radford, G. J. W.; Cox, J.; Wills, R. G. A.; Walsh, F. C.

    The Faradaic and non-Faradaic characteristics of a series of activated carbon particles (used to produce composite carbon-polymer electrodes for redox flow cells) have been determined using aqueous electrolytes (sulfuric acid and sodium polysulfide) at 295 K. The particles were mounted as a circular section (ca. 0.80 cm 2) shallow packed bed of 2.5 mm thickness in the direction of electrolyte flow (mean linear flow velocity ≈ 6 mm s -1). Cyclic voltammetry in deaerated, 1 mol dm -3 H 2SO 4 at 295 K indicated a specific capacitance in the range of 50-140 F g -1. Linear sweep voltammetry and galvanostatic step studies in an alkaline sodium polysulfide electrolyte (1.8 mol dm -3 Na 2S 2.11) have demonstrated marked differences amongst various types of activated carbon. Such differences are highlighted during galvanostatic charge-discharge cycling of half-cell electrodes in the polysulfide electrolyte. The electrochemical characteristics are compared to those based on (N 2 adsorption) gas porosimetry measurements.

  18. Molecular dynamics simulations of ring inversion in RDX

    NASA Astrophysics Data System (ADS)

    Wallis, Eric P.; Thompson, Donald L.

    1993-08-01

    Molecular dynamics simulations, using the finite volume method of Murrell and co-workers [J. Chem. Phys. 94, 3908 (1991)], have been carried out to study conformational changes in hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) in isolation and in dense Xe gas. The configurational distributions for RDX in a Xe bath and in the gas-phase are markedly different. The results show that as the solvent concentration increases, the concentration of RDX molecules in the boat conformation increases by a factor of about 4. The rate constant for the chair→boat ring inversion was calculated as a function of the xenon concentration [Xe]. The rate constant obeys Lindemann behavior at low concentrations, i.e., it increases with increasing solvent density. At [Xe]˜6.2 mol dm-3, the rate constant reaches a maximum (Kramer's turnover) and becomes a decreasing function of the solvent concentration. For [Xe] above 16.2 mol dm-3, the rate constant again increases as a function of the solvent density.

  19. Enhancement of ethanol oxidation at Pt and PtRu nanoparticles dispersed over hybrid zirconia-rhodium supports

    NASA Astrophysics Data System (ADS)

    Rutkowska, Iwona A.; Koster, Margaretta D.; Blanchard, Gary J.; Kulesza, Pawel J.

    2014-12-01

    A catalytic material for electrooxidation of ethanol that utilizes PtRu nanoparticles dispersed over thin films of rhodium-free and rhodium-containing zirconia (ZrO2) supports is described here. The enhancement of electrocatalytic activity (particularly in the potential range as low as 0.25-0.5 V vs. RHE), that has been achieved by dispersing PtRu nanoparticles (loading, 100 μg cm-2) over the hybrid Rh-ZrO2 support composed of nanostructured zirconia and metallic rhodium particles, is clearly evident from comparison of the respective voltammetric and chronoamperometric current densities recorded at room temperature (22 °C) in 0.5 mol dm-3 H2SO4 containing 0.5 mol dm-3 ethanol. Porous ZrO2 nanostructures, that provide a large population of hydroxyl groups in acidic medium in the vicinity of PtRu sites, are expected to facilitate the ruthenium-induced removal of passivating CO adsorbates from platinum, as is apparent from the diagnostic experiments with a small organic molecule such as methanol. Although Rh itself does not show directly any activity toward ethanol oxidation, the metal is expected to facilitate C-C bond splitting in C2H5OH. It has also been found during parallel voltammetric and chronoamperometric measurements that the hybrid Rh-ZrO2 support increases activity of the platinum component itself toward ethanol oxidation in the low potential range.

  20. The study of hydrogen bonding and π⋯π interactions in phenol⋯ethynylbenzene complex by IR spectroscopy

    NASA Astrophysics Data System (ADS)

    Vojta, Danijela; Vazdar, Mario

    2014-11-01

    Weak hydrogen bonds between phenol and ethynylbenzene in tetrachloroethene were explored by using FTIR spectroscopy. Association constants (Kc) were determined by high dilution method at two temperatures, 20 °C and 26 °C, and they are, respectively, 0.54 ± 0.09 mol-1 dm3 and 0.36 ± 0.08 mol-1 dm3. The position of ethynylbenzene stretching band, when in hydrogen bonding complex with phenol (Ctbnd C⋯), is proposed to be governed by the interplay of OH⋯π (Ctbnd C moiety or phenyl ring of ethynylbenzene) and π⋯π (phenyl ring of phenol⋯Ctbnd C moiety or phenyl ring of ethynylbenzene) interactions. This conclusion is supported by the findings on the complex between ethanol and ethynylbenzene; in the latter, Ctbnd C⋯ stretching band is shifted to the higher wavenumbers, as expected when ethynylbenzene interacts with hydrogen bond donor. Geometries and energies of the presumed complexes, as well as their vibrational spectra, are predicted by using ab initio calculations. The spectroscopic and thermodynamic data obtained here offer the missing pieces in the present picture of migration of H-atom of phenol OH group between competing hydrogen bond accepting centers on ethynylbenzene.

  1. Impact of lysozyme on stability mechanism of nanozirconia aqueous suspension

    NASA Astrophysics Data System (ADS)

    Szewczuk-Karpisz, Katarzyna; Wiśniewska, Małgorzata

    2016-08-01

    The effect of lysozyme (LSZ) presence on the zirconium(IV) oxide (ZrO2) aqueous suspension stability was examined. The applied zirconia contains mesopores (with a diameter about 30 nm) and its mean particle size is about 100 nm. To determine the stability mechanism of ZrO2 suspension in the biopolymer presence, the adsorption and electrokinetic (surface charge density and zeta potential) measurements were performed in the pH range 3-10. The lysozyme adsorption on the nanozirconia surface proceeds mainly through electrostatic forces. Under solid-polymer repulsion conditions, there is no adsorption of lysozyme (pH < 6, CNaCl 0.01 mol/dm3). The increase of solution ionic strength to 0.2 mol/dm3 causes screening of unfavourable forces and biopolymer adsorption becomes possible. The LSZ addition to the ZrO2 suspension influences its stability. At pH 3, 4.6 and 7.6, slight improvement of the system stability was obtained. In turn, at pH 9 considerable destabilization of nanozirconia particles covered by polymeric layers occurs.

  2. Partial molar volumes and viscous properties of glycine-aqueous urea solutions at 298.15 K

    NASA Astrophysics Data System (ADS)

    Deosarkar, S. D.; Ban, A. R.; Tawde, P. D.; Sawale, R. T.

    2015-07-01

    Density (ρ) and viscosity (η) of glycine ( c = 0.02-0.22 mol dm-3) in aqueous urea ( c = 0.5, 1.5, and 3.0 mol dm-3) solutions were measured at 298.15 K. Experimental density data has been used to calculate apparent molar volumes (φv) of glycine in aqueous and aqueous-urea solutions at 298.15 K. The dependence of apparent molar volumes on concentration of glycine was fitted to the Massons relation and apparent molar volume of glycine at infinite dilution (partial molar volume, φ{v/0}) was determined graphically. The partial molar volumes of transfer (Δtrφ{v/0}) of glycine at infinite dilution from pure water to aqueous-urea solutions at 298.15 K were calculated and interpreted in terms of various interactions and structural fittings in studied solutions. The relative viscosity data has been analyzed by Jones-Dole relation and viscosity B-coefficients were determined graphically. Viscosity B-coefficient of transfer (Δ B) was also calculated and compared with Δtrφ{v/0}.

  3. Black carbon in cloud-water and rain water during monsoon season at a high altitude station in India

    NASA Astrophysics Data System (ADS)

    Budhavant, K. B.; Rao, P. S. P.; Safai, P. D.; Leck, C.; Rodhe, H.

    2016-03-01

    We present results of measurements of black carbon (BC) from ground-based wet-only rainwater (RW) and cloud-water (CW) sampling at a mountain field station, Sinhagad, situated in south western India during the period from June 2008 to October 2010. The amount of BC in the sample was determined by photometry at a wavelength of 528 nm after a procedure including the filtration through a 0.4 μm polycarbonate membrane filter. Water soluble concentrations of major anions in RW and CW were also determined. The average concentration of BC in RW (16 μmol dm-3) is higher by at least a factor 2 than that found in similar studies reported from other parts of the world. On the other hand, the average concentration of BC in CW (47 μmol dm-3) is lower by about a factor of 2 than that found at other sites. The ratio between the average concentrations in CW and RW varies from 2 (K+) to 7 (SO42-). The ratio for BC was about 3. No significant difference was observed for pH. Analysis of air mass back trajectories and of correlations between the various components indicates that long range transport of pollutants and dust from East Africa and Southern part of the Arabian peninsula might contribute to the high concentrations of BC and some of the ionic constituents at Sinhagad during the monsoon season.

  4. Electrocatalytic oxidation of ethanol in acid medium: Enhancement of activity of vulcan-supported Platinum-based nanoparticles upon immobilization within nanostructured zirconia matrices

    NASA Astrophysics Data System (ADS)

    Rutkowska, Iwona A.; Kulesza, Pawel J.

    2014-09-01

    Composite electrocatalytic materials that utilize carbon (Vulcan) supported Pt or PtRu nanoparticles dispersed within thin films of zirconia (ZrO2) are considered here for oxidation of such a biofuel as ethanol in acid medium. The systems were characterized using electrochemical techniques as well as transmission electron microscopy. The enhancement of activity was clearly evident upon comparison of the respective voltammetric and chronoamperometric current densities recorded (at room temperature in 0.5 mol dm-3H2SO4 containing 0.5 mol dm-3 ethanol) using the Vulcan supported Pt and PtRu catalysts in the presence and absence of zirconia. In all cases, the noble metal loading was the same, 100 μg cm-2. Apparently, the existence of large population of hydroxyl groups (originating from zirconia) in the vicinity of Pt-based catalyst, in addition to possible specific interactions between zirconia and the ruthenium component of PtRu, facilitated the oxidative removal (from Pt) of the passivating (e.g., CO) reaction intermediates (adsorbates). By utilizing carbon supported, rather than bare or unsupported, Pt or PtRu nanoparticles (dispersed within the semiconducting zirconia), the overall charge distribution at the electrocatalytic interface was improved.

  5. Experimental determination of Henry's law constants of trifluoroacetic acid at 278-298 K

    NASA Astrophysics Data System (ADS)

    Kutsuna, Shuzo; Hori, Hisao

    Equilibrium partial pressures of trifluoroacetic acid ( P C(O)OH) over aqueous trifluoroacetic acid test solutions were determined at 278.15, 288.15, and 298.15 K. The concentration of undissociated trifluoroacetic acid ( C C(O)OH) in each test solution was determined by means of attenuated total reflection IR spectroscopy and window factor analysis. From the linear relationship between P C(O)OH and C C(O)OH, the Henry's law constant of trifluoroacetic acid ( KH) at 298.15 K was determined to be 5800±700 mol dm -3 atm -1 and KH at temperature T in K was determined to be KH=5780 exp[-4120×(1/298.15-1/ T)] in mol dm -3 atm -1. The KH value at 298.15 K was 0.65 times the reported value [Bowden, D.J., Clegg, S.L., Brimblecombe, P., 1996. The Henry's law constant of trifluoroacetic acid and its partitioning into liquid water in the atmosphere. Chemosphere 32, 405-420] for p Ka=0.47 and it was equal to that for p Ka=0.2.

  6. Radiation and quantum chemical studies of chalcone derivatives.

    PubMed

    Gaikwad, P; Priyadarsini, K I; Naumov, S; Rao, B S M

    2010-08-01

    The reactions of oxidizing radicals ((*)OH, Br(2)(*-), and SO(4)(*-)) with -OH-, -CH(3)-, or -NH(2)-substituted indole chalcones and hydroxy benzenoid chalcones were studied by radiation and quantum chemical methods. The (*)OH radical was found to react by addition at diffusion-controlled rates (k = 1.1-1.7 x 10(10) dm(3) mol(-1) s(-1)), but Br(2)(*-) radical reacted by 2 orders of magnitude lower. Quantum chemical calculations at the B3LYP/6-31+G(d,p) level of theory have shown that the (C2-OH)(*), (C11-OH)(*), and (C10-OH)(*) adducts of the indole chalcones and the (C7-OH)(*) and (C8-OH)(*) adducts of the hydroxy benzenoid chalcones are more stable with DeltaH = -39 to -28 kcal mol(-1) and DeltaG = -32 to -19 kcal mol(-1). This suggests that (*)OH addition to the alpha,beta-unsaturated bond is a major reaction channel in both types of chalcones and is barrierless. The stability and lack of dehydration of the (*)OH adducts arise from two factors: strong frontier orbital interaction due to the low energy gap between interacting orbitals and the negligible Coulombic repulsion due to small absolute values of Mulliken charges. The transient absorption spectrum measured in the (*)OH radical reaction with all the indole chalcone derivatives exhibited a maximum at 390 nm, which is in excellent agreement with the computed value (394 nm). The formation of three phenolic products under steady-state radiolysis is in line with the three stable (*)OH adducts predicted by theory. Independent of the substituent, identical spectra (lambda(max) = 330-360 and approximately 580 nm) were obtained on one-electron oxidation of the three indole chalcones. MO calculations predict the deprotonation from the -NH group is more efficient than from the substituent due to the larger electron density on the N1 atom forming the chalcone indolyl radical. Its reduction potential was determined to be 0.56 V from the ABTS(*-)/ABTS(2-) couple. In benzenoid chalcones, the (*)OH adduct spectrum is

  7. Auto-ignition and upper explosion limit of rich propane-air mixtures at elevated pressures.

    PubMed

    Norman, F; Van den Schoor, F; Verplaetsen, F

    2006-09-21

    The auto-ignition limits of propane-air mixtures at elevated pressures up to 15 bar and for concentrations from 10 mol% up to 70 mol% are investigated. The experiments are performed in a closed spherical vessel with a volume of 8 dm3. The auto-ignition temperatures decrease from 300 degrees C to 250 degrees C when increasing the pressure from 1 bar to 14.5 bar. It is shown that the fuel concentration most sensitive to auto-ignition depends on initial pressure. A second series of experiments investigates the upper flammability limit of propane-air mixtures at initial temperatures up to 250 degrees C and pressures up to 30 bar near the auto-ignition area. Finally the propane auto-oxidation is modelled using several detailed kinetic reaction mechanisms and these numerical calculations are compared with the experimental results. PMID:16716499

  8. Complexation of tetrandrine with calcium ion probed by various spectroscopic methods and molecular modeling

    NASA Astrophysics Data System (ADS)

    Stanculescu, Ioana; Mandravel, Cristina; Landy, David; Woisel, Patrice; Surpateanu, Gheorghe

    2003-07-01

    The formation of the complex between tetrandrine and the calcium ion, in solution, was studied using FTIR, UV-Vis, 1H NMR, 13C NMR and electrospray mass spectroscopy spectroscopic methods and molecular modeling. The calcium salts used were: Ca(ClO 4) 2·4H 2O and Ca(Picrate) 2 in the solvents: acetonitrile (CH 3CN), deuterated acetonitrile (CD 3CN) and tetrahydrofurane (THF). The determined complex stability constant was: 20277±67 dm 3 mol -1 and corresponding free energy Δ G0=-5.820±0.002 kcal mol -1. The molecular simulation of the complex formation with the MM3 Augmented force field integrated in CAChe provided useful data about its energy. Combining the experimental results and molecular modeling we propose a model for the structure of tetrandrine-Ca complex with an eight coordinated geometry.

  9. Improved, selective, human intestinal carboxylesterase inhibitors designed to modulate 7-ethyl-10-[4-(1-piperidino)-1-piperidino]carbonyloxycamptothecin (irinotecan; CPT-11) toxicity

    PubMed Central

    Hicks, Latorya D.; Hyatt, Janice L; Stoddard, Shana; Tsurkan, Lyudmila; Edwards, Carol C.; Wadkins, Randy M.; Potter, Philip M.

    2009-01-01

    CPT-11 is an antitumor prodrug that is hydrolyzed by carboxylesterases (CE) to yield SN-38, a potent topoisomerase I poison. However, the dose limiting toxicity is delayed diarrhea that is thought to arise, in part, from activation of the prodrug by a human intestinal CE (hiCE). Therefore, we have sought to identify selective inhibitors of hiCE that may have utility in modulating drug toxicity. We have evaluated one such class of molecules (benzene sulfonamides), and developed QSAR models for inhibition of this protein. Using these predictive models, we have synthesized a panel of fluorene analogues that are selective for hiCE, demonstrating no cross reactivity to the human liver CE, hCE1, or towards human cholinesterases, and have Ki values as low as 14nM. These compounds prevented hiCE-mediated hydrolysis of the drug and the potency of enzyme inhibition correlated with the clogP of the molecules. These studies will allow the development and application of hiCE-specific inhibitors designed to selectively modulate drug hydrolysis in vivo. PMID:19534556

  10. Line intensities and temperature-dependent line broadening coefficients of Q-branch transitions in the v2 band of ammonia near 10.4 μm

    NASA Astrophysics Data System (ADS)

    Sur, Ritobrata; Spearrin, R. Mitchell; Peng, Wen Y.; Strand, Christopher L.; Jeffries, Jay B.; Enns, Gregory M.; Hanson, Ronald K.

    2016-05-01

    We report measured line intensities and temperature-dependent broadening coefficients of NH3 with Ar, N2, O2, CO2, H2O, and NH3 for nine sQ(J,K) transitions in the ν2 fundamental band in the frequency range 961.5-967.5 cm-1. This spectral region was chosen due to the strong NH3 absorption strength and lack of spectral interference from H2O and CO2 for laser-based sensing applications. Spectroscopic parameters were determined by multi-line fitting using Voigt lineshapes of absorption spectra measured with two quantum cascade lasers in thermodynamically-controlled optical cells. The temperature dependence of broadening was measured over a range of temperatures between 300 and 600 K. These measurements aid the development of mid-infrared NH3 sensors for a broad range of gas mixtures and at elevated temperatures.

  11. Variables, Designs, and Instruments in the Search for Teacher Effectiveness. Beginning Teacher Evaluation Study. Technical Report Series. Technical Report 75-10-4.

    ERIC Educational Resources Information Center

    Joyce, Bruce R.; And Others

    When evaluating the effectiveness of beginning teachers, researchers are interested in defining those teacher behaviors which are related to student achievement in elementary school reading and mathematics. This review of the research literature addresses three issues: (1) definition of the variables which should receive the greatest emphasis in…

  12. Sorption of selenium(IV) and selenium(VI) onto magnetite

    NASA Astrophysics Data System (ADS)

    Martínez, M.; Giménez, J.; de Pablo, J.; Rovira, M.; Duro, L.

    2006-03-01

    In this work, we have studied the sorption of selenium ( 79Se is one of the main radionuclides in a spent nuclear fuel repository) on magnetite (Fe 3O 4), a mineral present in the near-field of a nuclear waste repository that might represent an important retardation factor for the mobility of many radionuclides. The sorption of both Se(IV) and Se(VI) onto magnetite has been fitted by a non-competitive Langmuir isotherm with Γmax = (3.13 ± 0.07) × 10 -6 mol m -2 and KL = (1.19 ± 0.07) × 10 6 dm 3 mol -1 for Se(IV) and Γmax = (3.5 ± 0.2) × 10 -6 mol m -2 and KL = (3.0 ± 0.1) × 10 5 dm 3 mol -1 for Se(VI). The variation of the sorption of selenium with pH has been modeled using the Triple Layer Surface Complexation Model and the equilibrium constants between selenium and magnetite have been obtained using the FITEQL program. For the case of Se(IV), the best fitting has been obtained using two inner-sphere complexes, lbond2 FeOHSeO 32- and lbond2 FeHSeO 3, while for Se(VI), the best fitting has been obtained considering only an outer-sphere complex, lbond2 FeOH 2+sbnd SeO 42-. The surface complexation reactions derived in this work are in agreement with those stated by other authors for sorption of Se(IV) and Se(VI) on hydrous iron oxides.

  13. The exploration of hydrogen bonding properties of 2,6- and 3,5-diethynylpyridine by IR spectroscopy

    NASA Astrophysics Data System (ADS)

    Vojta, Danijela; Kovačević, Goran; Vazdar, Mario

    2015-02-01

    Hydrogen bonding properties of 2,6- and 3,5-diethynylpyridine were analyzed by exploring of their interactions with trimethylphosphate, as hydrogen bond acceptor, or phenol, as hydrogen bond donor, in tetrachloroethene C2Cl4. The employment of IR spectroscopy enabled unravelling of their interaction pattern as well as the determination of their association constants (Kc) and standard reaction enthalpies (ΔrH⦵). The association of diethynylpyridines with trimethylphosphate in stoichiometry 1:1 is established through tbnd Csbnd H⋯O hydrogen bond, accompanied by the secondary interaction between Ctbnd C moiety and CH3 group of trimethylphosphate. In the complexes with phenol, along with the expected OH⋯N interaction, Ctbnd C⋯HO interaction is revealed. In contrast to 2,6-diethynylpyridine where the spatial arrangement of hydrogen bond accepting groups enables the simultaneous involvement of phenol OH group in both OH⋯N and OH⋯Ctbnd C hydrogen bond, in the complex between phenol and 3,5-diethynylpyridine this is not possible. It is postulated that cooperativity effects, arisen from the certain type of resonance-assisted hydrogen bonds, contribute the stability gain of the latter. Associations of diethynylpyridines with trimethylphosphate are characterized as weak (Kc ≈ 0.8-0.9 mol-1 dm3; -ΔrH⦵ ≈ 5-8 kJ mol-1), while their complexes with phenol as medium strong (Kc ≈ 5 mol-1 dm3; -ΔrH⦵ ≈ 15-35 kJ mol-1). Experimental findings on the studied complexes are supported with the calculations conducted at B3LYP/6-311++G(d,p) level of theory in the gas phase. Two conformers of diethynylpyridine⋯trimethylphosphate dimers are formed via tbnd Csbnd H⋯O interaction, whereas dimers between phenol and diethynylpyridines are established through OH⋯N interaction.

  14. Kinetics and thermodynamics of copper ions removal from wastewater by use of zeolite.

    PubMed

    Panayotova, M I

    2001-01-01

    Natural Bulgarian zeolite was tested for its ability to remove Cu2+ from model wastewater. Influence of process variables was investigated. It was found that the optimum wastewater to zeolite ratio is 100:1 and the optimum pH value of water to be treated is 5.5 to 7.5. Zeolite with finer particles shows a higher uptake capacity. The simultaneous presence of Ca2+ and Mg2+ in concentrations similar to their concentrations in Bulgarian natural water does not significantly influence the uptake of Cu2+. Zeolite modification by treating it with NaCl, CH3COONa and NaOH increases its uptake ability. Copper ions are strongly immobilized by modified zeolite and secondary pollution of water caused by its contact with preloaded zeolite is very low (1.5-2.5% of Cu2+ preliminary immobilized have been released back into acidified water). Contacting with 2 mol dm(-3) NaCl can easily regenerate loaded zeolite; best results were obtained for zeolite modified with NaCl. Requirements of Bulgarian standards for industrial wastewater can be met by a one-stage process for an initial Cu2+ concentration of 10 mg dm(-3), and by a two stage process for an initial Cu2+ concentration of 50 mg dm(-3). Uptake of Cu2+ by zeolite from neutral wastewater has proved to be as effective as Cu2+ removal by precipitation of copper hydroxide. The process of Cu2+ uptake by natural zeolite is best described by the kinetic equation for adsorption. This fact, together with the correlation found between the Cu2+ uptake and the amount of Na+, Ca2+ and K+ released into solution by zeolite shows that the ion exchange sorption plays the basic role in Cu2+ uptake by natural zeolite. The value obtained for the apparent activation energy (26.112 kJ mol(-1) implies that the process can be easily carried out with a satisfactory rate. The uptake equilibrium is best described by the Langmuir adsorption isotherm, with Langmuir constants KL= 6.4 x 10(-2) dm3 mg(-1) and M = 6.74 mg g(-1). The apparent equilibrium constant

  15. Simultaneous square-wave voltammetric determination of aspartame and cyclamate using a boron-doped diamond electrode.

    PubMed

    Medeiros, Roberta Antigo; de Carvalho, Adriana Evaristo; Rocha-Filho, Romeu C; Fatibello-Filho, Orlando

    2008-07-30

    A simple and highly selective electrochemical method was developed for the simultaneous determination of aspartame and cyclamate in dietary products at a boron-doped diamond (BDD) electrode. In square-wave voltammetric (SWV) measurements, the BDD electrode was able to separate the oxidation peak potentials of aspartame and cyclamate present in binary mixtures by about 400 mV. The detection limit for aspartame in the presence of 3.0x10(-4) mol L(-1) cyclamate was 4.7x10(-7) mol L(-1), and the detection limit for cyclamate in the presence of 1.0x10(-4) mol L(-1) aspartame was 4.2x10(-6) mol L(-1). When simultaneously changing the concentration of both aspartame and cyclamate in a 0.5 mol L(-1) sulfuric acid solution, the corresponding detection limits were 3.5x10(-7) and 4.5x10(-6) mol L(-1), respectively. The relative standard deviation (R.S.D.) obtained was 1.3% for the 1.0x10(-4) mol L(-1) aspartame solution (n=5) and 1.1% for the 3.0x10(-3) mol L(-1) cyclamate solution. The proposed method was successfully applied in the determination of aspartame in several dietary products with results similar to those obtained using an HPLC method at 95% confidence level. PMID:18585340

  16. Preconcentration and determination of cadmium by GFAAS after solid-phase extraction with synthetic zeolite.

    PubMed

    Minamisawa, Hiroaki; Okunugi, Ryoko; Minamisawa, Mayumi; Tanaka, Satoshi; Saitoh, Kazunori; Arai, Nobumasa; Shibukawa, Masami

    2006-05-01

    The solid-phase extraction (SPE) method for the preconcentration of trace amounts of cadmium using synthetic zeolite A-4 and its determination by graphite furnace atomic absorption spectrometry (GFAAS) was investigated. The preconcentration conditions, such as the optimum pH range of the sample solution for the adsorption of cadmium and the kind of acid solution for dissolving the cadmium-adsorbed synthetic zeolite A-4, as well as the measurement conditions for the determination of cadmium by GFAAS, e.g., the ashing and atomizing temperature, were investigated. Quantitative recovery of cadmium onto zeolite A-4 from the sample solution over the pH range 2.0 - 9.0 was achieved by the batch method. After the solid-phase (cadmium-adsorbed zeolite A-4) was separated from the sample solution by a membrane filter, it was dissolved in 2.0 cm(3) of 2.0 mol dm(-3) nitric acid. An aliquot of the resulting solution was injected into the graphite furnace. In GFAAS measurements an alternate gas (Ar, 90%; O(2), 10%) was used as a sheath gas, and the ashing temperature and atomizing temperature were 400 degrees C and 1600 degrees C, respectively. The detection limit (3 sigma) for cadmium was 0.002 microg dm(-3). The relative standard deviation at 0.010 microg dm(-3) was 3.5 - 4.5% (n = 5). The proposed method has been successfully applied to the analysis of trace cadmium in environmental water samples. PMID:16770049

  17. Characterization of relaxant mechanism of H2 S in mouse corpus cavernosum.

    PubMed

    Aydinoglu, Fatma; Ogulener, Nuran

    2016-04-01

    The aim of this study was to investigate the mechanism of H2 S-induced relaxation in mouse corpus cavernosal tissue. l-cysteine (10(-6) × 10(-3) mol/L) and exogenous H2 S (NaHS; 10(-6) to 10(-3) mol/L) induced concentration-dependent relaxation. l-cysteine-induced relaxations was reduced by d,l-propargylglycine, a cystathionine gamma lyase (CSE) inhibitor but not influenced by aminooxyacetic acid, a cystathionine beta synthase (CBS) inhibitor. l-cysteine induced relaxations, but not of those of H2 S diminished in endothelium-denuded tissues. N(ω) -nitro-l-arginine (l-NA; 10(-4) mol/L), a nitric oxide synthase inhibitor, and ODQ (10(-4) mol/L), a guanylyl cyclase inhibitor, increased the H2 S-induced relaxation. Zaprinast (5 × 10(-6) mol/L) and sildenafil (10(-6) mol/L), phosphodiesterase inhibitors, inhibited H2 S-induced relaxation. Adenylyl cyclase inhibitors N-ethylmaleimide (2.5 × 10(-5) mol/L) and SQ22536 (10(-4) mol/L) reduced relaxation to H2 S. Also, H2 S-induced relaxation was reduced by KCl (50 mmol/L), 4-aminopyridine (10(-3) mol/L), a Kv inhibitor, glibenclamide (10(-5) mol/L), a KATP inhibitor or barium chloride (10(-5) mol/L), a KIR inhibitor. However, H2 S-induced relaxation was not influenced by apamin (10(-6) mol/L), a SKC a (2+) inhibitor, charybdotoxin (10(-7) mol/L), an IKC a (2+) and BKC a (2+) inhibitor or combination of apamin and charybdotoxin. Nifedipine (10(-6) mol/L), an L-type calcium channel blocker and atropine (10(-6) mol/L), a muscarinic receptor blocker, inhibited H2 S-induced relaxation. However, H2 S-induced relaxation was not influenced by ouabain (10(-4) mol/L), a Na(+) /K(+) -ATPase inhibitor. This study suggests that H2 S endogenously synthesizes from l-cysteine by CSE endothelium-dependent in mouse corpus cavernosum tissue, and exogenous H2 S may cause endothelium-independent relaxations via activation of K channels (KATP channel, KV channels, KIR channels), L-type voltage-gated Ca(2+) channels, adenylyl cyclase

  18. Sunlight-driven photochemical halogenation of dissolved organic matter in seawater: a natural abiotic source of organobromine and organoiodine.

    PubMed

    Méndez-Díaz, José Diego; Shimabuku, Kyle K; Ma, Jing; Enumah, Zachary O; Pignatello, Joseph J; Mitch, William A; Dodd, Michael C

    2014-07-01

    Reactions of dissolved organic matter (DOM) with photochemically generated reactive halogen species (RHS) may represent an important natural source of organohalogens within surface seawaters. However, investigation of such processes has been limited by difficulties in quantifying low dissolved organohalogen concentrations in the presence of background inorganic halides. In this work, sequential solid phase extraction (SPE) and silver-form cation exchange filtration were utilized to desalt and preconcentrate seawater DOM prior to nonspecific organohalogen analysis by ICP-MS. Using this approach, native organobromine and organoiodine contents were found to range from 3.2-6.4 × 10(-4) mol Br/mol C and 1.1-3.8 × 10(-4) mol I/mol C (or 19-160 nmol Br L(-1) and 6-36 nmol I L(-1)) within a wide variety of natural seawater samples, compared with 0.6-1.2 × 10(-4) mol Br/mol C and 0.6-1.1 × 10(-5) mol I/mol C in terrestrial natural organic matter (NOM) isolates. Together with a chemical probe method specific for RHS, the SPE+ICP-MS approach was also employed to demonstrate formation of nanomolar levels of organobromine and organoiodine during simulated and natural solar irradiation of DOM in artificial and natural seawaters. In a typical experiment, the organobromine content of 2.1 × 10(-4) mol C L(-1) (2.5 mg C L(-1)) of Suwannee River NOM in artificial seawater increased by 69% (from 5.9 × 10(-5) to 1.0 × 10(-4) mol Br/mol C) during exposure to 24 h of simulated sunlight. Increasing I(-) concentrations (up to 2.0 × 10(-7) mol L(-1)) promoted increases of up to 460% in organoiodine content (from 8.5 × 10(-6) to 4.8 × 10(-5) mol I/mol C) at the expense of organobromine formation under the same conditions. The results reported herein suggest that sunlight-driven reactions of RHS with DOM may play a significant role in marine bromine and iodine cycling. PMID:24933183

  19. Relationship between electrochemical potentials and substitution reaction rates of ferrocene-containing β-diketonato rhodium(I) complexes; cytotoxicity of [Rh(FcCOCHCOPh)(cod)].

    PubMed

    Conradie, Jeanet; Swarts, Jannie C

    2011-06-14

    A series of ferrocene-containing rhodium complexes of the type [Rh(FcCOCHCOR)(cod)] (cod = 1,5-cyclooctadiene) with R = CF(3), 1, (E(pa)(Rh) = 269; E(o)'(Fc) = 329 mV vs. Fc/Fc(+)), CCl(3), 2, (E(pa) = 256; E(o)' = 312 mV), CH(3), 3, (E(pa) = 177; E(o)' = 232 mV), Ph = C(6)H(5), 4, (E(pa) = 184; E(o)' = 237 mV), and Fc = ferrocenyl = (C(5)H(5))Fe(C(5)H(4)), 5, (E(pa) = 135; E(o)'(Fc1) = 203; E(o)'(Fc2) = 312 mV), have been studied electrochemically in CH(3)CN. Results indicated that the rhodium(I) centre is irreversibly oxidised to Rh(III) in a two-electron transfer process before the ferrocenyl fragment is reversibly oxidized in a one-electron transfer process. The peak anodic (oxidation) potential, E(pa), (in V vs. Fc/Fc(+)) of the rhodium core in 1-5 relates to k(2), the second-order rate constant for the substitution of (FcCOCHCOR)(-) with 1,10-phenanthroline in [Rh(FcCOCHCOR)(cod)] to form [Rh(phen)(cod)](+) in methanol at 25 °C with the equation lnk(2) = 39.5 E(pa)(Rh) - 3.69, while the formal oxidation potential of the ferrocenyl groups in 1-5 relates to k(2) by lnk(2) = 40.8 E(o)'(Fc)-6.34. Complex 4 (IC(50) = 28.2 μmol dm(-3)) was twice as cytotoxic as the free FcCOCH(2)COPh ligand having IC(50) = 54.2 μmol dm(-3), but approximately one order of magnitude less toxic to human HeLa neoplastic cells than cisplatin (IC(50) = 2.3 μmol dm(-3)). PMID:21423964

  20. Biogeochemical and microbiological characteristic of the pockmark sediments, the Gdansk Deep, The Baltic Sea

    NASA Astrophysics Data System (ADS)

    Pimenov, Nikolay; Kanapatskiy, Timur; Sivkov, Vadim; Toshchakov, Stepan; Korzhenkov, Aleksei; Ulyanova, Marina

    2016-04-01

    Comparison of the biogeochemical and microbial features was done for the gas-bearing and background sediments as well as near-bottom water of the Gdansk Deep, The Baltic Sea. Data were received in October, 2015 during 64th cruise of the R/V Akademik Mstislav Keldysh. Gas-bearing sediments were sampled within the known pockmark (Gas-Point, depth 94 m). Background sediments area (BG-Point, depth 86 m) was located several km off the pockmark area. The sulphate concentration in the pore water of the surface sediment layer (0-5 cm) of Gas-Point was 9,7 mmol/l, and sharply decreased with depth (did not exceed 1 mmol/l deeper than 50 cm). The sulphate concentration decrease at BG-Point also took place but was not so considerable. Sulphate concentration decrease is typical for the organic rich sediments of the high productive areas, both as for the methane seep areas. Fast sulphate depletion occurs due to active processes of its microbial reduction by consortium of the sulphate-reduction bacteria, which may use low-molecular organic compounds or hydrogen, formed at the different stages of the organic matter destruction; as well as within the process of the anaerobic methane oxidation by consortium of the methane-trophic archaea and sulphate-reduction bacteria. Together with sulphate concentration decrease the methane content increase, typical for the marine sediments, occurred. At the Gas-Point the methane concentration varied within 10 μmol/dm3 in the surface layer till its maximum at sediment horizon of 65 cm (5 mmol/dm3), and decreased to 1.5 mmol/dm3 at depth of 300 cm. The BG-Point maximum values were defined at sediment horizon 6 cm (2,6 μmol/dm3). Methane sulfate transition zone at the Gas-Point sediments was at 25-35 cm depth; whereas it was not defined at the BG-Point mud. High methane concentration in the gas-bearing sediments results in the formation of the methane seep from the sediments to the near-bottom water. So the Gas-Point near-bottom waters were

  1. Complexation of mercury(II) ions with humic acids in tundra soils

    NASA Astrophysics Data System (ADS)

    Vasilevich, R. S.; Beznosikov, V. A.; Lodygin, E. D.; Kondratenok, B. M.

    2014-03-01

    The interaction mechanisms of mercury(II) ions with preparations of humic acids (HAs) isolated from organic horizons of surface-gleyed soils (Haplic Stagnosol (Gelic, Siltic)) of shrub tundra and hydromorphic peat gley soils (Histic Cryosol (Reductaquic, Siltic)) of moss-lichen tundra have been studied. The particular features of the interactions between the mercury(II) ions and the HAs are related to the molecular structure of the HAs, the mercury concentration range, and the environmental parameters. The fixation of mercury(II) ions into stable coordination compounds is most efficient in the pH range of 2.5-3.5. At the element concentrations below 0.50 μmol/dm3, the main complexing sites of HAs are their peripheral aminoacid functional groups. Pyrocatechol, salicylate, and phenolic groups from the nuclear moiety of molecules interact in the concentration range of 0.0005-0.50 mmol/dm3; the physical sorption of mercury hydroxo complexes by the surface of HAs is the main process occurring in the system.

  2. INTERACTION OF LASER RADIATION WITH MATTER: Influence of Ca and Pb impurities on the bulk optical strength of ultrapure NaCl and KCl crystals

    NASA Astrophysics Data System (ADS)

    Vinogradov, An V.; Voszka, R.; Kovalev, Valerii I.; Faĭzullov, F. S.; Janszky, J.

    1987-06-01

    A significant increase (by a factor of about 3) of the bulk damage threshold in the case of interaction of CO2 laser radiation pulses with ultrapure NaCl and KCl crystals grown in a reactive atmosphere was observed on introduction of divalent metal ions Ca and Pb in concentrations of 10-5-10-6 mol/mol. Impurities were introduced in concentrations of 10-8-10-3 and 2×10-7-10-4 mol/mol into the melts of KCl and NaCl, respectively. The concentration of other impurities (including OH) did not exceed ~10-6 mol/mol. A physical model was developed to account for the observed dependence on the basis of an analogy between a system of colloidal particles and F centers in a crystal and a liquid-vapor system.

  3. HEF-19-induced relaxation of colonic smooth muscles and the underlying mechanisms

    PubMed Central

    Wei, Yuan-Yuan; Sun, Lu-Lu; Fu, Shou-Ting

    2013-01-01

    AIM: To investigate the relaxant effect of chromane HEF-19 on colonic smooth muscles isolated from rabbits, and the underlying mechanisms. METHODS: The relaxant effect and action mechanisms of HEF-19 were investigated using descending colon smooth muscle of the rabbits. Preparations 1 cm long were mounted in 15-mL tissue baths containing Tyrode’s solution, maintained at 37 ± 0.5 °C and aerated with a mixture of 5% CO2 in oxygen (Carbogen). The tension and amplitude of the smooth muscle strips were recorded after adding HEF-19 (10-6, 10-5 and 10-4 mol/L). After cumulative administration of four antispasmodic agents, including acetylcholine chloride (Ach) (10-4 mol/L), histamine (10-4 mol/L), high-K+ (60 mmol/L) and BaCl2 (8.2 mmol/L), HEF-19 (3 × 10-7-3 × 10-4 mol/L) was added to investigate the relaxant effect of HEF-19. CaCl2 (10-4-2.5 × 10-3 mol/L) was added cumulatively to the smooth muscle preparations pretreated with and without HEF-19 (1 × 10-6 or 3 × 10-6 mol/L) and verapamil (1 × 10-7 mol/L) to study the mechanisms involved. Finally, phasic contraction was induced with ACh (15 × 10-6 mol/L), and CaCl2 (4 × 10-3 mol/L) was added to the smooth muscle preparations pretreated with and without HEF-19 (3 × 10-6 mol/L or 1 × 10-5 mol/L) and verapamil (1 × 10-7 mol/L) in calcium-free medium to further study the underlying mechanisms. RESULTS: HEF-19 (1 × 10-6, 1 × 10-5 and 1 × 10-4 mol/L) suppressed spontaneous contraction of rabbit colonic smooth muscles. HEF-19 (3 × 10-7-3 × 10-4 mol/L) relaxed in a concentration-dependent manner colonic smooth muscle preparations pre-contracted with BaCl2, high-K+ solution, Ach or histamine with respective EC50 values of 5.15 ± 0.05, 5.12 ± 0.08, 5.58 ± 0.16 and 5.25 ± 0.24, thus showing a spasmolytic activity. HEF-19 (1 × 10-6 mol/L and 3 × 10-6 mol/L) shifted the concentration-response curves of CaCl2 to the right and depressed the maximum response to CaCl2. The two components contracted by Ach were

  4. Concentration dependences of density, viscosity, refractive index, and other derived properties of metoclopramide aqueous solutions at 303.15 K

    NASA Astrophysics Data System (ADS)

    Sawale, R. T.; Deosarkar, S. D.; Kalyankar, T. M.

    2015-07-01

    Density ( ρ), viscosity ( η) and refractive index ( n D) of an antiemetic drug metoclopramide (4-amino-5-chloro- N-(2-(diethylamino)ethyl)-2-methoxybenzamide hydrochloride) solutions containing amino acids (glycine, D-alanine, L-cystine and L-histidine) were measured in the concentration range 0.01-0.17 mol/dm3 at 303.15 K. The apparent molar volume (φv) of this drug in aqueous amino acid solutions was calculated from the density data and fitted to the Massons relation, and the partial molar volume φ{v/0} of the drug was determined graphically. The partial molar volumes of transfer (Δtrφ{v/0}) of drug at infinite dilution from pure water to aqueous amino acid solutions were calculated and interpreted in terms of different interactions between the drug and amino acids.

  5. Kinetics and mechanism of alkane hydroperoxidation with tert-butyl hydroperoxide catalysed by a vanadate anion.

    PubMed

    Shul'pin, Georgiy B; Kozlov, Yuriy N

    2003-07-01

    tert-Butyl hydroperoxide oxidizes alkanes in acetonitrile at 60 degrees C if the soluble vanadium(v) salt, n-Bu4NVO3, is used as a catalyst. Alkyl hydroperoxides are formed as main products which decompose during the course of the reaction to produce the more stable corresponding alcohols and ketones. Turnover numbers (ie. numbers of moles of products per one mole of a catalyst) attained 250. The kinetics and selectivity of the reaction have been studied. The mechanism proposed involves the formation of a complex between the V(V) species and t-BuOOH (K5 was estimated to be 5 dm3 mol(-1)) followed by decomposition of this complex (k6 = 0.2 s(-1)). The generated V(IV) species reacts with another t-BuOOH molecule to produce an active t-BuO* radical which attacks the hydrocarbon. PMID:12945701

  6. Spectrophotometric determination of glucosamine and its analogous amino sugars with o-hydroxyhydroquinonephthalein and palladium(II).

    PubMed

    Yamaguchi, Takako; Inoue, Mayumi; Miyachi, Kanako; Tominaga, Hiroshi; Fujita, Yoshikazu

    2004-02-01

    A simple and highly sensitive spectrophotometric method for the determination of glucosamine and its analogous amino sugars was established based on fading of the palladium(II)-o-hydroxyhydroquinonephthalein-hexadecyltrimethylammonium complex. In the determination of glucosamine, Beer's law is obeyed in the range of 0.02 - 0.18 microg ml(-1), with an effective molar absorptivity at 630 nm and the relative standard deviation being 8.4 x 10(5) dm3 mol(-1) cm(-1) and 1.08% (n = 10). This method is about 70-times more sensitive than the Elson-Morgan method. The method was successfully applied to the assay of glucosamine in actual samples. PMID:15055973

  7. Ionizing radiation induced degradation of monuron in dilute aqueous solution

    NASA Astrophysics Data System (ADS)

    Kovács, Krisztina; He, Shijun; Míle, Viktória; Földes, Tamás; Pápai, Imre; Takács, Erzsébet; Wojnárovits, László

    2016-07-01

    The decomposition of monuron was investigated in dilute aqueous solutions using pulse radiolysis and γ-radiolysis in order to identify the intermediates and final products. The main reaction takes place between monuron and the hydroxyl radicals yielding hydroxycyclohexadienyl type radicals with a second order rate constant of (7.4±0.2)×109 mol-1 dm3 s-1. In •OH reactions, the aminyl and phenoxyl radicals may also form. Dechlorination was observed in both hydroxyl radical and hydrated electron reactions. The •OH induced dechlorination reactions are suggested to occur through OH substitution or phenoxyl radical formation. The rate of oxidation is very high in the presence of dissolved oxygen. Some of the results are also supported by quantum chemical calculations.

  8. Dimethoxymethane and trimethoxymethane as alternative fuels for fuel cells

    NASA Astrophysics Data System (ADS)

    Chetty, Raghuram; Scott, Keith

    The electrooxidation of dimethoxymethane (DMM) and trimethoxymethane (TMM) was studied at different platinum-based electrocatalysts deposited onto a titanium mesh substrate by thermal decomposition of chloride precursors. Half-cell tests showed an increase in oxidation current for the methoxy fuels at the platinum electrode with the alloying of ruthenium and tin. Increase in reaction temperature and reactant concentration showed an increase in current density for the mesh-based anodes similar to carbon-supported catalysts. Single fuel cell tests, employing the titanium mesh anode with PtRu and PtSn catalysts showed maximum power densities up to 31 mW cm -2 and 48 mW cm -2 for 1.0 mol dm -3 aqueous solutions of DMM and TMM, respectively at 60 °C using oxygen.

  9. Metal complexes of salicylhydroxamic acid (H2Sha), anthranilic hydroxamic acid and benzohydroxamic acid. Crystal and molecular structure of [Cu(phen)2(Cl)]Cl x H2Sha, a model for a peroxidase-inhibitor complex.

    PubMed

    O'Brien, E C; Farkas, E; Gil, M J; Fitzgerald, D; Castineras, A; Nolan, K B

    2000-04-01

    Stability constants of iron(III), copper(II), nickel(II) and zinc(II) complexes of salicylhydroxamic acid (H2Sha), anthranilic hydroxamic acid (HAha) and benzohydroxamic acid (HBha) have been determined at 25.0 degrees C, I=0.2 mol dm(-3) KCl in aqueous solution. The complex stability order, iron(III) > copper(II) > nickel(II) approximately = zinc(II) was observed whilst complexes of H2Sha were found to be more stable than those of the other two ligands. In the preparation of ternary metal ion complexes of these ligands and 1,10-phenanthroline (phen) the crystalline complex [Cu(phen)2(Cl)]Cl x H2Sha was obtained and its crystal structure determined. This complex is a model for hydroxamate-peroxidase inhibitor interactions. PMID:10830846

  10. Metal ion-tetracycline interactions in biological fluids. 2. Potentiometric study of magnesium complexes with tetracycline, oxytetracycline, doxycycline, and minocycline, and discussion of their possible influence on the bioavailability of these antibiotics in blood plasma.

    PubMed

    Berthon, G; Brion, M; Lambs, L

    1983-08-01

    The formation constants of the various complexes formed by magnesium with four tetracycline derivatives, namely, tetracycline itself, oxytetracycline, doxycycline, and minocycline, were determined by potentiometry over large pH ranges under experimental conditions pertaining to blood plasma (37 degrees C, NaCl 0.15 mol dm-3). The results were used, together with those previously obtained on the complexation of these tetracyclines with proton and calcium, to assess the influence of the two alkali earth metal ions on the bioavailability of these drugs in blood plasma. Accordingly, simulations of the distribution of the four tetracyclines into their different proton and metal complex species were calculated. The distributions confirm that, in combination with the protein-bound fraction of the tetracyclines, the metal-bound fraction represents more than 99% of these drugs in plasma, the extent of their free fraction commonly being less than 1%. PMID:6619838

  11. Large electronic third-order optical nonlinearities of cyanine dyes measured by resonant femtosecond degenerate four-wave mixing

    NASA Astrophysics Data System (ADS)

    Kasatani, Kazuo

    2003-01-01

    Third-order optical nonlinearities of several cyanine dyes were measured under resonant conditions by the femtosecond degenerate four-wave mixing (DFWM) technique. Temporal profiles of the DFWM signal were measured with a time resolution of 0.3 ps, and were found to consist of at least two components, the coherent instantaneous nonlinear response and the delayed response with a decay time constant of several hundred picoseconds. The latter can be attributed to molecular rotational relaxation of these dyes. The values of electronic component of the optical nonlinear susceptibility, χ e xxxx (3), for these dyes were ≈2×10 -12 esu at the very low concentration of 1×10 -5 mol dm -3. The electronic component of molecular hyperpolarizability, γe, was calculated to be ≈1×10 -28 esu for each dye.

  12. Electrochemical cell design for the impedance studies of chlorine evolution at DSA(®) anodes.

    PubMed

    Silva, J F; Dias, A C; Araújo, P; Brett, C M A; Mendes, A

    2016-08-01

    A new electrochemical cell design suitable for the electrochemical impedance spectroscopy (EIS) studies of chlorine evolution on Dimensionally Stable Anodes (DSA(®)) has been developed. Despite being considered a powerful tool, EIS has rarely been used to study the kinetics of chlorine evolution at DSA anodes. Cell designs in the open literature are unsuitable for the EIS analysis at high DSA anode current densities for chlorine evolution because they allow gas accumulation at the electrode surface. Using the new cell, the impedance spectra of the DSA anode during chlorine evolution at high sodium chloride concentration (5 mol dm(-3) NaCl) and high current densities (up to 140 mA cm(-2)) were recorded. Additionally, polarization curves and voltammograms were obtained showing little or no noise. EIS and polarization curves evidence the role of the adsorption step in the chlorine evolution reaction, compatible with the Volmer-Heyrovsky and Volmer-Tafel mechanisms. PMID:27587166

  13. Effect of carboxymethyl cellulose and ionic strength on stability of mineral suspensions in potash ore flotation systems.

    PubMed

    Pawlik, M; Laskowski, J S; Ansari, A

    2003-04-15

    The adsorption of sodium carboxymethyl cellulose from aqueous solutions varying in ionic strength from that of distilled water to 50% NaCl/KCl brine (about 3.5 mol/dm(3)) onto illite and dolomite has been studied. The purpose of this work was to investigate the solvency effects in the phenomena underlying the potash flotation process that is carried out in saturated brine. Based on viscosity measurements, the adsorption results were analyzed in terms of a simple model of polymer macromolecules in solution. Suspension stability measurements carried out concomitantly with adsorption tests showed the ranges of carboxymethyl cellulose concentration over which the tested suspensions either were aggregated or were restabilized. PMID:12686172

  14. Role of charge transfer interaction and the chemical physics behind effective fulleropyrrolidine/porphyrin non-covalent interaction in solution.

    PubMed

    Mondal, Ashis; Santhosh, Kotni; Bauri, Ajoy; Bhattacharya, Sumanta

    2014-01-01

    The present paper reports the photophysical insights on supramolecular interaction of a monoporphyrin derivative, namely, 1, with C60 pyrrolidine tris-acid ethyl ester (PyC60) in toluene and benzonitrile. The ground state interaction between PyC60 and 1 is facilitated through charge transfer interaction. Both UV-Vis and steady state measurements elicit almost similar magnitude of binding constant for the PyC60/1 complex in toluene and benzonitrile, viz., 6825 and 6540 dm(3 )mol(-1), respectively. Life time measurement evokes that rate of charge separation is fast in benzonitrile. Both hybrid-DFT and DFT calculations provide very good support in favor of electronic charge-separation in PyC60/1 system in vacuo. PMID:24291433

  15. Flue gas treatment for SO2 removal with air-sparged hydrocyclone technology.

    PubMed

    Bokotko, Romuald P; Hupka, Jan; Miller, Jan D

    2005-02-15

    Laboratory results from an initial study on the removal of SO2 from gas mixtures are reported using air-sparged hydrocyclone (ASH) technology. Tap water and alkaline solutions were used for absorption, and the influence of gas flow rate, water flow rate, and length of the ASH unit were investigated. The research results indicate thatthe air-sparged hydrocyclone can be used as a highly efficient absorber for SO2 emissions. The ASH allows for 97% SO2 removal using water alone for sulfur dioxide content in the gas phase of 5 g/m3. All SO2 is removed in weakly alkaline solution (0.01 mol NaOH/dm3). PMID:15773494

  16. Synthesis of novel amorphous calcium carbonate by sono atomization for reactive mixing.

    PubMed

    Kojima, Yoshiyuki; Kanai, Makoto; Nishimiya, Nobuyuki

    2012-03-01

    Droplets of several micrometers in size can be formed in aqueous solution by atomization under ultrasonic irradiation at 2 MHz. This phenomenon, known as atomization, is capable of forming fine droplets for use as a reaction field. This synthetic method is called SARM (sono atomization for reactive mixing). This paper reports on the synthesis of a novel amorphous calcium carbonate formed by SARM. The amorphous calcium carbonate, obtained at a solution concentration of 0.8 mol/dm(3), had a specific surface area of 65 m(2)/g and a composition of CaCO(3)•0.5H(2)O as determined using thermogravimetric/differential thermal analysis (TG-DTA). Because the ACC had a lower hydrate composition than conventional amorphous calcium carbonate (ACC), the ACC synthesized in this paper was very stable at room temperature. PMID:21788149

  17. The use of modified divinylbenzene-polystyrene resins in the separation of fermentation products. A case study utilizing amino acids and a dipeptide.

    PubMed

    Casillas, J L; Addo-Yobo, F; Kenney, C N; Aracil, J; Martínez, M

    1992-01-01

    The adsorption of phenylalanine, aspartic acid, asparagine and aspartame from phosphate-buffered aqueous solutions with modified divinyl-benzene-polystyrene resins has been investigated using high pressure liquid chromatography (HPLC). The pH studied was 2.8, the temperature range was 293-313 K and the ionic strength was maintained at 1.0 mol dm-3. Over the range of variables investigated, the adsorption isotherms are linear and may be characterized by temperature and pH-dependent apparent adsorption equilibrium constants, characteristic of the resin-adsorbate system. By studying the dependence on temperature of this adsorption constant, heats of adsorption and entropy of adsorption have been estimated. In terms of the heat liberated on adsorption, the amino acids and a dipeptide can be ranked thus: aspartame > phenylalanine > aspartic acid > asparagine. PMID:1368901

  18. Solute effects on the interaction between water and ethanol in aged whiskey.

    PubMed

    Nose, Akira; Hojo, Masashi; Suzuki, Mika; Ueda, Tadaharu

    2004-08-25

    The hydrogen-bonding structure of water-ethanol in whiskey was examined on the basis of (1)H NMR chemical shifts of the OH of water and ethanol. Phenolic acids and aldehydes (gallic, vanillic, and syringic acids; vanillin and syringaldehyde) exhibited their structure-making effects regardless of the presence or absence of 0.1 or 0.2 mol dm(-3) acetic acid. The OH-proton chemical shifts were measured for 32 malt whiskey samples of a distillery, aged for 0-23 years in five different types of casks. The OH-proton chemical shift values of the whiskies shifted toward the lower field in proportion to their contents of total phenols. It can be concluded that the strength of the hydrogen bonding in aged whiskies is directly predominated by acidic and phenolic components gained in oak wood casks and not dependent on just the aging time. PMID:15315370

  19. Radiolysis of aqueous solutions of acetic acid in the presence of Na-montmorillonite

    NASA Technical Reports Server (NTRS)

    Navarro-Gonzalez, R.; Negron-Mendoza, A.; Ramos, S.; Ponnamperuma, C.

    1990-01-01

    The gamma-irradiation of 0.8 mol dm-3 aqueous, oxygen-free acetic acid solutions was investigated in the presence or absence of Na-montmorillonite. H2, CH4, CO, CO2, and several polycarboxylic acids were formed in all systems. The primary characteristics observed in the latter system were: (1) Higher yield of the decomposition of acetic acid; (2) Lower yield of the formation of polycarboxylic acids; (3) No effect on the formation of methane; (4) Higher yield of the formation of carbon dioxide; and (5) The reduction of Fe3+ in the octahedral sites of Na-montmorillonite. A possible reaction scheme was proposed to account for the observed changes. The results are important in understanding heterogeneous processes in radiation catalysis and might be significant to prebiotic chemistry.

  20. Stability of the aqueous suspensions of nanotubes in the presence of nonionic surfactant.

    PubMed

    Lisunova, Milana O; Lebovka, Nikolai I; Melezhyk, Olexander V; Boiko, Yurie P

    2006-07-15

    Stability of aqueous suspensions of multiwalled carbon nanotubes (MWNTs) and their percolation behavior are investigated. Nanotubes of aqueous suspensions show a strong tendency to aggregation and networking into electroconductive clusters. The percolation threshold of the electrical conductivity is rather low and of order phi approximately 0.01 (where phi is the volume fraction), which can be explained by the high aspect ratio of MWNTs. Strong influence of the nonionic surfactant Triton X-305 on the colloidal stability of aqueous suspensions of MWNTs is observed. Addition of surfactant exerts a stabilizing effect at surfactant concentration C(s) proportional to the weight concentration C of MWNTs, C(s) approximately C mol/dm3. The transient behavior of electrical conductivity in the aqueous suspensions is explained by fractal aggregation processes. The fractal dimension is shown to be sensitive to the surfactant concentration C(s). PMID:16600279

  1. Properties of graphite-stainless steel composite in bipolar plates in simulated anode and cathode environments of PEM fuel cells

    NASA Astrophysics Data System (ADS)

    Włodarczyk, Renata

    2014-09-01

    The use of a graphite-stainless steel composite as bipolar plates (BP) in polymer electrolyte membrane fuel cells (PEMFCs) has been evaluated. The study covers measurements of mechanical properties, microstructural examination, analysis of surface profile, wettability, porosity and corrosion resistance of the composite. The corrosion properties of the composite were examined in 0.1 mol·dm-3 H2SO4 + 2 ppm F- saturated with H2 or with O2 and in solutions with different pH: in Na2SO4+ 2 ppm F- (pH = 1.00, 3.00, 5.00) at 80 °C. The performed tests indicate that the graphite modified with stainless steel can be a good choice to be used as a bipolar plate in PEM fuel cells.

  2. A conductivity study of unsymmetrical 2:1 type "complex ion" electrolyte: cadmium chloride in dilute aqueous solutions.

    PubMed

    Apelblat, Alexander; Esteso, Miguel A; Bešter-Rogač, Marija

    2013-05-01

    Systematic and precise measurements of electrical conductivities of aqueous solutions of cadmium chloride were performed in the 2 × 10(-5)-1 × 10(-2) mol·dm(-3) concentration range, from 278.15 to 313.15 K. Determined conductances were interpreted in terms of molecular model which includes a mixture of two 1:1 and 2:1 electrolytes. The molar limiting conductances of λ(0)(CdCl(+), T) and λ(0)(1/2Cd(2+), T), the equilibrium constants of CdCl(+) formation K(T) and the corresponding standard thermodynamic functions were evaluated using the Quint-Viallard conductivity equations, the Debye-Hückel equations for activity coefficients and the mass-action equation. An excellent agreement between calculated and experimental conductivities was reached. PMID:23534843

  3. The Multiple Forms of alpha-Amylase Enzyme of the Araucaria Species of South America: A. araucana (Mol.) Koch and A. angustifolia (Bert.) O. Kutz : A Comparative Study.

    PubMed

    Salas, E; Cardemil, L

    1986-08-01

    alpha-Amylase is one of the major enzymes present in the seeds of both Araucaria species of South America and it initiates starch hydrolysis during germination and early seedling growth. The pattern of the multiple forms of alpha-amylase of the two Araucaria species was investigated by electrophoresis and isoelectrofocusing of the native enzyme in polyacrylamide gels. The enzyme forms were compared in the embryo and megagametophyte of quiescent seeds and of seeds imbibed for 18, 48, and 90 hours. Specific alpha-amylase enzyme forms appear and disappear during these imbibition periods showing both similarities and differences between tissues and species. Before imbibition, there are five alpha-amylase forms identical in both tissues, but different between species. After 18 hours of imbibition, there are two enzyme forms in both tissues of Araucaria araucana seeds, only one form in the embryo of Araucaria angustifolia but two forms in the megagametophyte of this specie. After 48 hours of seed imbibition, most of the enzyme forms present in quiescent seeds reappear. At 90 hours of imbibition different enzyme forms are detected in the embryo with respect to the gametophyte. The changes in form patterns of alpha-amylase are discussed according to a possible regulation of gene expression by endogenous gibberellins. PMID:16664944

  4. Corrigendum to "Electronic structure and photoelectron spectra of nickel (II) acetylacetonate and its thio- and amino-substituted analogues" [J. Mol. Struct. 1099 (2015) 579-587

    NASA Astrophysics Data System (ADS)

    Vovna, Vitaliy I.; Korochentsev, Vladimir V.; Komissarov, Alexander A.; L'vov, Igor B.; Myshakina, Nataliya S.

    2016-01-01

    The authors regret to inform that it was given erroneous spelling of Vitaliy I. Vovna author name in the published version of the article. It was written "Vitaliy V. Vovna" instead of "Vitaliy I. Vovna".

  5. Structural characterization of two benzene-1,2-di-amine complexes of zinc chloride: a mol-ecular compound and a co-crystal salt.

    PubMed

    Zick, Patricia L; Geiger, David K

    2016-07-01

    The structures of two zinc complexes containing bidentate benzene-1,2-di-amine ligands are reported. (Benzene-1,2-di-amine-κ(2) N,N')di-chloro-idozinc, [ZnCl2(C6H8N2)], (I), displays a distorted tetra-hedral coordination sphere for the metal cation. The di-amine ligand and the Zn atom reside on a crystallographic mirror plane. In the 1:1 co-crystal salt trans-di-aqua-bis-(4,5-di-methyl-benzene-1,2-di-amine-κ(2) N,N')zinc chloride-4,5-di-methyl-benzene-1,2-di-amine (1/1), [Zn(C8H12N2)2(H2O)2]Cl2·2C8H12N2, (II), the zinc(II) complex cation exhibits a tetra-gonally distorted octa-hedral coordination sphere. The Zn atom sits on a crystallographically imposed inversion center and the di-amine ligands are tilted 30.63 (6)° with respect to the ZnN4 plane. Both complexes exhibit extensive hydrogen bonding. In (I), a stacked-sheet extended structure parallel to (101) is observed. In (II), the co-crystallized di-amine is hydrogen-bonded to the complex cation via O-H⋯N and N-H⋯N linkages. These units are in turn linked into planes along (200) by O-H⋯Cl and N-H⋯Cl hydrogen bonds. PMID:27555958

  6. Engineering microstructure and redox properties in the mixed conductor Ce(0.9)Pr(0.1)O(2-δ) + Co 2 mol%.

    PubMed

    Balaguer, María; Solís, Cecilia; Roitsch, Stefan; Serra, José M

    2014-03-21

    10% Praseodymium doped ceria exhibits a combination of mixed ionic and electronic conductivity, redox catalytic properties and chemical compatibility with water and carbon dioxide at high temperatures. Minor additions of cobalt oxide have been demonstrated to act as a sintering aid as well as an effective promoter of the electronic conduction. However, an excess of sintering temperature causes cobalt aggregation into the grain boundaries as inferred from FE-SEM/EDX and TEM analysis. The redox behaviour of the materials was studied by means of temperature programmed desorption (TPD) and reduction (TPR). This work shows the systematic study of sintering conditions in order to understand the evolution of the material microstructure, grain boundaries and the role of cobalt in this complex system. The final purpose of the work is to improve both electronic and oxygen ion transport properties for their potential application as oxygen-transport membranes and solid oxide fuel cell components. The sample sintered at 1000 °C exhibited the highest total conductivity at high temperatures, which is principally related to the improvement in the electronic conductivity through the grain boundary network. PMID:24141898

  7. pH- and mol-ratio dependent formation of zinc(II) coordination polymers with iminodiacetic acid: Synthesis, spectroscopic, crystal structure and thermal studies

    SciTech Connect

    Ni Lubin; Zhang Ronghua; Liu Qiongxin; Xia Wensheng; Wang Hongxin; Zhou Zhaohui

    2009-10-15

    Three novel zinc coordination polymers (NH{sub 4}){sub n}[Zn(Hida)Cl{sub 2}]{sub n} (1), [Zn(ida)(H{sub 2}O){sub 2}]{sub n} (2), [Zn(Hida){sub 2}]{sub n}.4nH{sub 2}O (3) (H{sub 2}ida=iminodiacetic acid) and a monomeric complex [Zn(ida)(phen)(H{sub 2}O)].2H{sub 2}O (4) (phen=1,10-phenanthroline) have been synthesized and characterized by X-ray diffraction methods. 1 and 2 form one-dimensional (1-D) chain structures, whereas 3 exhibits a three-dimensional (3-D) diamondoid framework with an open channel. The mononuclear complex 4 is extended into a 3-D supramolecular architecture through hydrogen bonds and pi-pi stacking. Interestingly, cyclic nonplanar tetrameric water clusters are observed that encapsulated in the 3-D lattice of 4. Based on {sup 1}H and {sup 13}C NMR observations, there is obvious coordination of complex 2 in solution, while 1 and 3 decompose into free iminodiacetate ligand. Monomer [Zn(ida)(H{sub 2}O){sub 3}] (5) is considered as a possible discrete species from 2. These coordination polymers can serve as good molecular precursors for zinc oxide. - Text3: Reaction of zinc salt with iminodiacetic acid afforded three new coordination polymers 1-3 and a monomer 4, which is dependent on pH value and molar ratio of the reactants.

  8. A cell surface integral membrane glycoprotein of 85,000 mol wt (gp85) associated with triton X-100-insoluble cell skeleton.

    PubMed

    Tarone, G; Ferracini, R; Galetto, G; Comoglio, P

    1984-08-01

    The Triton X-100-insoluble skeleton of baby hamster kidney BHK cells consists of the nucleus, intermediate-size filaments, and actin fibers. By transmission electron microscopy, membrane fragments were found to be associated with these insoluble structures. When radioiodinated or [3H]glucosamine-labeled cells were extracted with 0.5% Triton, most plasma membrane glycoproteins were solubilized except for a glycoprotein with a molecular weight of 85,000 (gp85) that remained associated with the insoluble skeletons. Immunoprecipitation with a specific antiserum indicated that the gp85 is not a proteolytic degradation product of fibronectin, an extracellular matrix glycoprotein insoluble in detergent. A monoclonal antibody of BHK cells specific for gp85 was produced. Immunofluorescence analysis with this monoclonal antibody indicated that gp85 is not associated with the extracellular matrix, but is confined to the cell membrane. Both in fixed and unfixed intact cells, fluorescence was concentrated in dots preferentially aligned in streaks on the cell surface. Gp85 was found to behave as an integral membrane protein interacting with the hydrophobic core of the lipid bilayer since it was extracted from membrane preparations by ionic detergents such as SDS, but not by 0.1 N NaOH (pH 12) in the absence of detergents, a condition known to release peripheral molecules. Association of gp85 with the cell skeleton was unaffected by increasing the Triton concentration up to 5%, but it was affected when actin filaments were dissociated or when a protein-denaturing agent (6 M urea) was used in the presence of Triton, suggesting that protein-protein interactions are involved in the association of gp85 with the cell skeleton. We conclude that gp85 is an integral plasma membrane glycoprotein that might have a role in cell surface-cytoskeleton interaction. PMID:6378925

  9. Retraction: A. Amedei et al. Multiple Sclerosis: The Role of Cytokines in Pathogenesis and in Therapies. Int. J. Mol. Sci. 2012, 13, 13438-13460.

    PubMed

    Editorial Office, International Journal Of Molecular Science

    2016-01-01

    We have been made aware that the title paper [1] contains text taken verbatim from previously published articles by Shyi-Jou Chen et al. [2] and Ghislain Opdenakker and Jo Van Damme [3].[...]. PMID:27384554

  10. Corrigendum to "Stereochemical analysis of menthol and menthylamine isomers using calculated and experimental optical rotation data" [J. Mol. Struct. 1103 (2016) 166-176

    NASA Astrophysics Data System (ADS)

    Reinscheid, F.; Reinscheid, U. M.

    2016-04-01

    The authors regret to inform that a typographical error occurred in the published version of the article. In the last sentence of the abstract and of the conclusion the correct expression with the specific optical rotation should read "-10 < [α] < +10". We would like to apologize for the inconvenience caused.

  11. Ouverture mécanique de la molécule d'ADN par micro-manipulation et mesure de force

    NASA Astrophysics Data System (ADS)

    Bockelmann, Ulrich; Essevaz-Roulet, B.; Thomen, Philippe; Heslot, François

    In this paper we summarize part of our work on the mechanical unzipping of DNA. We have prepared molecular constructions which allow us to attach the two complementary strands of one end of a single DNA molecule of the bacteriophage λ separately to a glass microscope slide and a microscopic bead. In a first series of experiments, a soft microneedle acting as a force sensor is attached to the bead and its deflection is measured with an optical microscope. In a second series, we use an optical trapping interferometer to capture the bead and to measure its displacement to nm resolution. The sample is slowly displaced with respect to the force measurement device, leading to a progressive opening of the double helix. The force measured during this mechanical opening shows a characteristic variation which is related to the base pair sequence of the DNA molecule. To cite this article: U. Bockelmann et al., C. R. Physique 3 (2002) 585-594.

  12. Three-dimensional representations of complex carbohydrates and polysaccharides--SweetUnityMol: a video game-based computer graphic software.

    PubMed

    Pérez, Serge; Tubiana, Thibault; Imberty, Anne; Baaden, Marc

    2015-05-01

    A molecular visualization program tailored to deal with the range of 3D structures of complex carbohydrates and polysaccharides, either alone or in their interactions with other biomacromolecules, has been developed using advanced technologies elaborated by the video games industry. All the specific structural features displayed by the simplest to the most complex carbohydrate molecules have been considered and can be depicted. This concerns the monosaccharide identification and classification, conformations, location in single or multiple branched chains, depiction of secondary structural elements and the essential constituting elements in very complex structures. Particular attention was given to cope with the accepted nomenclature and pictorial representation used in glycoscience. This achievement provides a continuum between the most popular ways to depict the primary structures of complex carbohydrates to visualizing their 3D structures while giving the users many options to select the most appropriate modes of representations including new features such as those provided by the use of textures to depict some molecular properties. These developments are incorporated in a stand-alone viewer capable of displaying molecular structures, biomacromolecule surfaces and complex interactions of biomacromolecules, with powerful, artistic and illustrative rendering methods. They result in an open source software compatible with multiple platforms, i.e., Windows, MacOS and Linux operating systems, web pages, and producing publication-quality figures. The algorithms and visualization enhancements are demonstrated using a variety of carbohydrate molecules, from glycan determinants to glycoproteins and complex protein-carbohydrate interactions, as well as very complex mega-oligosaccharides and bacterial polysaccharides and multi-stranded polysaccharide architectures. PMID:25475093

  13. pH- and mol-ratio dependent formation of zinc(II) coordination polymers with iminodiacetic acid: synthesis, spectroscpic, crystal structure and thermal studies

    PubMed Central

    Ni, Lu-Bin; Zhang, Rong-Hua; Liu, Qiong-Xin; Xia, Wen-Sheng; Wang, Hongxin; Zhou, Zhao-Hui

    2009-01-01

    Three novel zinc coordination polymers (NH4)n[Zn(Hida)Cl2]n (1), [Zn(ida)(H2O)2]n (2), [Zn(Hida)2]n·4nH2O (3) (H2ida = iminodiacetic acid) and a monomeric complex [Zn(ida)(phen)(H2O)]·2H2O (4) (phen=1,10-phenanthroline) have been synthesized and characterized by X-ray diffraction methods. 1 and 2 form one-dimensional (1-D) chain structures, whereas 3 exhibits a three-dimensional (3-D) diamondoid framework with an open channel. The mononuclear complex 4 is extended into a 3-D supramolecular architecture through hydrogen bonds and π-π stacking. Interestingly, cyclic nonplanar tetrameric water clusters are observed that encapsulated in the 3-D lattice of 4. Based on 1H and 13C NMR observations, there is obvious coordination of complex 2 in solution, while 1 and 3 decompose into free iminodiacetate ligand. Monomer [Zn(ida)(H2O)3] (5) is considered as a possible discrete species from 2. These coordination polymers can serve as good molecular precursors for zinc oxide. PMID:20161370

  14. Corrigendum to "New REMPI observations and analyses for Rydberg and ion-pair states of HI" [J. Mol. Spectrosc. 290 (2013) 5-12

    NASA Astrophysics Data System (ADS)

    Hróðmarsson, Helgi Rafn; Wang, Huasheng; Kvaran, Ágúst

    2016-06-01

    This article presents a comprehensive overview of Rydberg and ion-pair states for HI in the two-photon excitation region of 69,600-72,300 cm-1. There are two errors in the paper that need to be addressed. These are associated with (i) the wavelength calibration and (ii) the assignment of the d3Π0(1) Rydberg state spectrum.

  15. Structural characterization of two benzene-1,2-di­amine complexes of zinc chloride: a mol­ecular compound and a co-crystal salt

    PubMed Central

    Zick, Patricia L.; Geiger, David K.

    2016-01-01

    The structures of two zinc complexes containing bidentate benzene-1,2-di­amine ligands are reported. (Benzene-1,2-di­amine-κ2 N,N′)di­chloro­idozinc, [ZnCl2(C6H8N2)], (I), displays a distorted tetra­hedral coordination sphere for the metal cation. The di­amine ligand and the Zn atom reside on a crystallographic mirror plane. In the 1:1 co-crystal salt trans-di­aqua­bis­(4,5-di­methyl­benzene-1,2-di­amine-κ2 N,N′)zinc chloride–4,5-di­methyl­benzene-1,2-di­amine (1/1), [Zn(C8H12N2)2(H2O)2]Cl2·2C8H12N2, (II), the zinc(II) complex cation exhibits a tetra­gonally distorted octa­hedral coordination sphere. The Zn atom sits on a crystallographically imposed inversion center and the di­amine ligands are tilted 30.63 (6)° with respect to the ZnN4 plane. Both complexes exhibit extensive hydrogen bonding. In (I), a stacked-sheet extended structure parallel to (101) is observed. In (II), the co-crystallized di­amine is hydrogen-bonded to the complex cation via O—H⋯N and N—H⋯N linkages. These units are in turn linked into planes along (200) by O—H⋯Cl and N—H⋯Cl hydrogen bonds. PMID:27555958

  16. Nouvelles techniques d'imagerie multiphonique : vers une nouvelle génération de marqueurs moléculaires

    NASA Astrophysics Data System (ADS)

    Blanchard-Desce, Mireille

    Novel microscopies based on nonlinear optical (NLO) phenomena such as two-photon excited fluorescence (TPEF) and second-harmonic generation (SHG) have gained overwhelming popularity in the biology community owing to the many advantages they provide in biological imaging. Examples of molecular engineering approaches toward NLO-probes specifically designed for SHG and/or TPEF imaging of lipid membranes and biological cells are given here, providing an illustration of their intriguing potential in the area of real-time, non-damaging imaging of biological structures. Optimized NLO-markers open new routes for improved monitoring and better understanding of fundamental dynamic processes. To cite this article: M. Blanchard-Desce, C. R. Physique 3 (2002) 439-448.

  17. [Development of a cookie formulation for celiac people using defatted Chilean hazel nut (Gevuina avellana. Mol) flour and quinoa (Chenopodium quinoa Willd) flour].

    PubMed

    Villarroel, Mario; Huiriqueo, Carolina; Hazbun, Julia; Carrillo, Diego

    2009-06-01

    The present investigation deals with the optimization of a cookie formulation based on deffated chilean hazel nut flour (DCHF) and quinoa flour (QF) characterized for being gluten free resources, aimed to increment the nutritional options of the celiac population using Taguchi methodology. Four independent variables DCHF, QF, ammonium bicarbonated (AB) and baking time (BT) at three levels each one were considered in orden to evaluate their effects on the sensory quality (SQ) and signal to noise ratio (S/N) of the optimized product. To determine the optimun levels and relative magnitude of the effects of each parameter L9 3(4) orthogonal array with nine design points and two replications each totalizing eighteen experimental runs was used. Results were analyzed using differences between the average values of each factor according to the working level and also analysis of variance (ANOVA). The desired characteristics were the maxima SQ and S/R responses, so Taguchi "the larger the better" performance formula was used. Optimun conditions turn out to be DCHF 24.3%; QF 7.1%; AB 0.6%; BT 22 minutes. Among the chemical characteristics highlighted components such as protein (8.9%) and fiber (12.7%). Regarding the prolamine content of 1.5 ppm its result was under the limit considered for CODEX (20 ppm) classifying this product as gluten free. On the other hand, the shelf life study expressed as conjugated dienes (CD) was 3.6% after 45 days at 30 degrees C storage conditions proving this product is stable to rancidness. Hedonic test data shown 100% approval, splitted as follow 75% (like very much) and 25% (like). Finally 100% of celiac peoples inquired in this study were well disposed to buy this product. PMID:19719016

  18. The crystal structures of three clozapinium salts: different mol­ecular configurations, and supra­molecular assembly in one, two and three dimensions

    PubMed Central

    Kaur, Manpreet; Jasinski, Jerry P.; Yathirajan, Hemmige S.; Kavitha, Channappa N.; Glidewell, Christopher

    2015-01-01

    The structures of three salts derived from clozapine, 8-chloro-11-(4-methyl­piperazin-1-yl)-5H-dibenzo[b,e][1,4]diazepine, are reported, namely, clo­za­pin­ium 3,5-di­nitro­benzoate dimethyl sulfoxide monosolvate, C18H20ClN4 +·C7H3N2O6 −·C2H6OS, (I), where the dimethyl sulfoxide component is disordered over two sets of atomic sites having occupancies 0.627 (2) and 0.373 (2); clo­za­pin­ium hydrogen maleate 0.21-hydrate, C18H20ClN4 +·C4H3O4 −·0.21H2O, (II), and clozapinium 2-hy­droxy­benzoate, C18H20ClN4 +·C7H5O3 −, (III). In all three salts, the protonation site is the methyl­ated N atom of the piperazine ring, and the dimensions and conformations of the fused tricyclic system are very similar. However, differences are apparent in the piperazine component: in both compounds (II) and (III), the unprotonated N atom of this ring has a pyramidal geometry, but in compound (I) this atom has a planar geometry. In compound (III), both N-substituents in this ring occupy equatorial sites, but in compound (II) the fused tricyclic system occupies an axial site of the piperazine ring. The independent components of compound (I) are linked within the selected asymmetric unit by a combination of N—H⋯O and C—H⋯O hydrogen bonds, and these hydrogen-bonded aggregates are linked into chains by an aromatic π–π stacking inter­action. In compound (II), the components are linked into sheets by a combination of O—H⋯O, N—H⋯O and C—H⋯O hydrogen bonds, and in compound (III), a combination of N—H⋯O, C—H⋯O and C—H⋯N hydrogen bonds links the components into a three-dimensional framework structure. Comparisons are made with some similar compounds. PMID:26029402

  19. Corrigendum to "Synthesis, structural features, and methyl methacrylate polymerisation of binuclear zinc(II) complexes with tetradentate pyrazolyl ligands" [J. Mol. Struct. 1063 (2014) 70-76

    NASA Astrophysics Data System (ADS)

    Kim, Sunghoon; Kim, Dongil; Lee, Ha-Jin; Lee, Hyosun

    2015-05-01

    The authors regret to inform that 4,4‧-bis-(N,N-di(1H-pyrazolyl-1-methyl)phenyl)methane (L2) and its binuclear 4,4‧-bis-(N,N-di-(1H-pyrazolyl-1-methyl)phenyl)methane(dichloro)Zn(II) complex, namely, [L2Zn2Cl4] in the paper were published as the thesis for the degree of master in the Department of Chemistry at Kyungpook National University in 2003.

  20. Crystal structure of zwitterionic 4-(ammonio­methyl)­benzoate: a simple mol­ecule giving rise to a complex supra­molecular structure

    PubMed Central

    Atria, Ana María; Garland, Maria Teresa; Baggio, Ricardo

    2014-01-01

    The asymmetric unit of the title compound, C8H9NO2·H2O consists of an isolated 4-(ammonio­meth­yl)benzoate zwitterion derived from 4-amino­methyl­benzoic acid through the migration of the acidic proton, together with a water molecule of crystallization that is disordered over three sites with occupancy ratios (0.50:0.35:0.15). In the crystal structure, N—H⋯O hydrogen bonds together with π–π stacking of the benzene rings [centroid–centroid distance = 3.8602 (18) Å] result in a strongly linked, compact three-dimensional structure. PMID:25484753

  1. A novel citrate selective electrode based on surfactant modified nano-clinoptilolite.

    PubMed

    Hasheminejad, Mahdieh; Nezamzadeh-Ejhieh, Alireza

    2015-04-01

    A citrate-selective sensor was prepared by modification of a PVC membrane with modified nano-clinoptilolite particles by hexadecyltrimethyl ammonium surfactant (SMZ). A Nernstian slope of 29.9 ± 0.2 mV per decade of citrate concentration was obtained over the concentration range of 5.0 × 10(-5)-5.0 × 10(-2) mol L(-1) of citrate. The electrode showed a fast response time (⩽ 10 s) and a detection limit of 1.3 × 10(-5) mol L(-1) of citrate. The linear range and detection limit were respectively changed to 1.0 × 10(-4)-5.0 × 10(-2) mol L(-1) and 1.0 × 10(-4) mol L(-1) of citrate when the micronized clinoptilolite particles were used. PMID:25442622

  2. EIS and XPS investigations on the corrosion mechanism of ternary Zn-Co-Mo alloy coatings in NaCl solution

    NASA Astrophysics Data System (ADS)

    Winiarski, J.; Tylus, W.; Szczygieł, B.

    2016-02-01

    The changes in composition of the corrosion products of electrodeposited ternary Zn-Co-Mo alloy coatings on AISI 1015 steel during exposure to 0.5 mol dm-3 NaCl solution were investigated. XPS studies demonstrated that at the initial stage of corrosion on the surface of Zn-Co-Mo coating zinc hydroxide layer is formed. Hydroxyl groups react with chloride and carbonate ions which lead to the formation of zinc hydroxy carbonates and zinc hydroxy chlorides. The share of these compounds in the oxidation products is initially large. However, with time zinc hydroxy compounds slowly changes to zinc oxide, which is more stable corrosion product. It was estimated that after 24 h of exposure to NaCl solution nearly 60% of zinc detected on the surface of Zn-Co-Mo coating was present in the ZnO form, 18% in the form of zinc hydroxy chloride, and more than 21% as zinc hydroxy carbonate. XPS analyses revealed that the amount of zinc hydroxy chloride increases as the exposure time lengthens and it is significantly higher than at the surface of binary Zn-Co coating. The presence of crystalline zinc chloride hydroxide as a stable product of corrosion of ternary Zn-Co-Mo alloy coating in a 0.5 mol dm-3 NaCl solution was confirmed by XRD analysis. According to XRD and FTIR other zinc corrosion products like: ZnO, Zn(OH)2 and Zn5(CO3)2(OH)6 were also present. The results of XPS and EIS measurements allow us to assume that in the presence of Mo in the alloy, on the surface of ternary Zn-Co-Mo alloy (3.4 wt.% Co, 2.7 wt.% Mo) coating more zinc hydroxy chloride is formed, which favors higher corrosion resistance of this coating.

  3. Considerable Enhancement of Emission Yields of [Au(CN)2(-)] Oligomers in Aqueous Solutions by Coexisting Cations.

    PubMed

    Wakabayashi, Ryo; Maeba, Junichi; Nozaki, Koichi; Iwamura, Munetaka

    2016-08-01

    The photophysical properties of [Au(CN)2(-)] oligomers in aqueous solutions were investigated as functions of coexisting cations as well as the viscosity and temperature of solutions. A solution of [Au(CN)2(-)] in the concentration range of 0.03-0.2 mol/dm(3) exhibited emission peaks at 460-480 nm because of the presence of oligomers larger than trimers. Although the emission yields (ϕem) of K[Au(CN)2] solutions were <1%, it considerably increased to 43% when 1.0 mol/dm(3) tetraethylammonium chloride (Et4NCl) was added. The lifetimes of the main emission bands were also significantly varied with additional salts, e.g., KCl, 15 ns; Et4NCl, 520 ns. The time-resolved emission measurements of [Au(CN)2(-)] in a water/glycerol mixture indicated that the lifetimes were almost directly proportional to the inverse of the viscosity of the solution. On the other hand, the intrinsic lifetimes of dimers and trimers with weak emission in shorter wavelength regions were very short and independent of the viscosity of the solutions and coexisting cations (dimer, ∼25 ps; trimer, ∼2 ns). These results indicated that the deactivation of the excited-state [Au(CN)2(-)]n oligomers (n ≥ 4) was dominated by the dissociation of the oligomers to a shorter species (dimer or trimer). The hydrophobic interactions between tetraalkylammonium cations and CN ligands remarkably stabilized the larger oligomers and suppressed the dissociation of the excited-state oligomers, which enhanced the emission yield of the oligomers. This work provides a new method of "exciplex tuning" by changing the environment of excited-state [Au(CN)2(-)]n oligomers. PMID:27391559

  4. The exploration of hydrogen bonding properties of 2,6- and 3,5-diethynylpyridine by IR spectroscopy.

    PubMed

    Vojta, Danijela; Kovačević, Goran; Vazdar, Mario

    2014-11-01

    Hydrogen bonding properties of 2,6- and 3,5-diethynylpyridine were analyzed by exploring of their interactions with trimethylphosphate, as hydrogen bond acceptor, or phenol, as hydrogen bond donor, in tetrachloroethene C2Cl4. The employment of IR spectroscopy enabled unravelling of their interaction pattern as well as the determination of their association constants (Kc) and standard reaction enthalpies (ΔrH(⦵)). The association of diethynylpyridines with trimethylphosphate in stoichiometry 1:1 is established through CH⋯O hydrogen bond, accompanied by the secondary interaction between CC moiety and CH3 group of trimethylphosphate. In the complexes with phenol, along with the expected OH⋯N interaction, CC⋯HO interaction is revealed. In contrast to 2,6-diethynylpyridine where the spatial arrangement of hydrogen bond accepting groups enables the simultaneous involvement of phenol OH group in both OH⋯N and OH⋯CC hydrogen bond, in the complex between phenol and 3,5-diethynylpyridine this is not possible. It is postulated that cooperativity effects, arisen from the certain type of resonance-assisted hydrogen bonds, contribute the stability gain of the latter. Associations of diethynylpyridines with trimethylphosphate are characterized as weak (Kc≈0.8-0.9mol(-1)dm(3); -ΔrH(⦵)≈5-8kJmol(-1)), while their complexes with phenol as medium strong (Kc≈5mol(-1)dm(3); -ΔrH(⦵)≈15-35kJmol(-1)). Experimental findings on the studied complexes are supported with the calculations conducted at B3LYP/6-311++G(d,p) level of theory in the gas phase. Two conformers of diethynylpyridine⋯trimethylphosphate dimers are formed via CH⋯O interaction, whereas dimers between phenol and diethynylpyridines are established through OH⋯N interaction. PMID:25467686

  5. In situ monitoring of corrosion mechanisms and phosphate inhibitor surface deposition during corrosion of zinc-magnesium-aluminium (ZMA) alloys using novel time-lapse microscopy.

    PubMed

    Sullivan, James; Cooze, Nathan; Gallagher, Callum; Lewis, Tom; Prosek, Tomas; Thierry, Dominique

    2015-01-01

    In situ time-lapse optical microscopy was used to examine the microstructural corrosion mechanisms in three zinc-magnesium-aluminium (ZMA) alloy coated steels immersed in 1% NaCl pH 7. Preferential corrosion of MgZn(2) lamellae within the eutectic phases was observed in all the ZMA alloys followed by subsequent dissolution of Zn rich phases. The total extent and rate of corrosion, measured using time-lapse image analysis and scanning vibrating electrode technique (SVET) estimated mass loss, decreased as Mg and Al alloying additions were increased up to a level of 3 wt% Mg and 3.7 wt% Al. This was probably due to the increased presence of MgO and Al(2)O(3) at the alloy surface retarding the kinetics of cathodic oxygen reduction. The addition of 1 × 10(-2) mol dm(-3) Na(3)PO(4) to 1% NaCl pH 7 had a dramatic influence on the corrosion mechanism for a ZMA with passivation of anodic sites through phosphate precipitation observed using time-lapse image analysis. Intriguing rapid precipitation of filamentous phosphate was also observed and it is postulated that these filaments nucleate and grow due to super saturation effects. Polarisation experiments showed that the addition of 1 × 10(-2) mol dm(-3) Na(3)PO(4) to the 1% NaCl electrolyte promoted an anodic shift of 50 mV in open circuit potential for the ZMA alloy with a reduction in anodic current of 2.5 orders of magnitude suggesting that it was acting primarily as an anodic inhibitor supporting the inferences from the time-lapse investigations. These phosphate additions resulted in a 98% reduction in estimated mass loss as measured by SVET demonstrating the effectiveness of phosphate inhibitors for this alloy system. PMID:25912828

  6. Chemical properties which control selectivity and efficacy of aromatic N-oxide bioreductive drugs.

    PubMed

    Wardman, P; Priyadarsini, K I; Dennis, M F; Everett, S A; Naylor, M A; Patel, K B; Stratford, I J; Stratford, M R; Tracy, M

    1996-07-01

    Pulse radiolysis was used to generate radicals from one electron reduction of 1,2,4-benzotriazine-1,4-dioxides (derivatives of tirapazamine), and of imidazo [1,2-a]quinoxaline-4-oxides (analogues of RB90740), which have selective toxicity towards hypoxic cells. Radicals from the mono N-oxides (from the latter compounds) react with oxygen approximately 10-40 times faster than does the tirapazamine radical. Radicals from the tirapazamine analogues studied react with oxygen up to approximately 10 times slower than tirapazamine radicals. The quinoxaline N-oxide radicals are involved in prototropic equilibria with pK(a) values (5.5 to 7.4) spanning that reported for tirapazamine (6.0). Generation of radicals radiolytically in the presence of H donors (formate, 2-propanol, deoxyribose) indicate a chain reaction ascribed to H abstraction by the drug radical. The protonated drug radical is much more reactive than the radical anion (H abstraction rate constant approximately equal to 10(2) - 10(3) dm3 mol-1 s-1). Chain termination is ascribed to drug radical-radical reactions, i.e. radical stability in anoxia, with rate constants 2k approximately equal to 1 x 10(7) to 2 x 10(8) dm3 mol-1 s-1 at pH approximately 7.4. Estimates of the reduction potentials of the drug-radical couples in water at pH 7 for two of the mono-N-oxides were in the range-0.7 to 0.8 V vs NHE at pH 7. PMID:8763850

  7. Determination of Cr(VI) in welding fumes by anion-exchange fast protein liquid chromatography with electrothermal atomic absorption spectrometric detection.

    PubMed

    Milacic, Radmila; Scancar, Janez; Tusek, Janez

    2002-02-01

    The applicability of an anion-exchange fast protein liquid chromatographic-electrothermal atomic absorption spectrometric procedure (FPLC-ETAAS) was investigated for the determination of Cr(VI) in welding fumes after alkaline extraction of aerosols loaded on filters. Gas tungsten arc welding (GTAW) of stainless steel was applied. Samples of welding fumes were collected during regular welding on polycarbonate membrane filters of 8 microm and 0.4 microm pore size (inhalable and respirable aerosols). Alkaline extraction (2% NaOH-3% Na2CO3) of filters in a heated ultrasonic bath was applied to leach Cr from the airborne particulate matter. 0.5 cm3 of sample extract was then injected onto an anion-exchange FPLC column. Tris-HCl buffer (0.005 mol dm(-3), pH 8.0) and the same buffer with NaCl (0.5 mol dm(-3)) were employed in gradient elution (15 min, flow rate 1 cm3 min(-1)). The separated Cr species were determined "off line" by ETAAS in 0.5 cm3 fractions. Cr(VI) was reproducibly and quantitatively eluted from 12.0 to 13.0 min with a maximum peak at 12.5 min. Good repeatability of measurement (+/-3.0%) of alkaline extracts was obtained for Cr(VI). The LOD (3s) was found to be 0.035 microg m(-3) Cr(VI), when 2 m3 of aerosols were collected on the filter. Validation of the procedure was performed by spiking alkaline extracts and by the analysis of standard reference material CRM 545, Cr(VI) in welding dust loaded on a filter. The technique was successfully applied for the determination of Cr(VI) in welding fumes. PMID:11939630

  8. A novel approach for speciation of airborne chromium by convective-interaction media fast-monolithic chromatography with electrothermal atomic-absorption spectrometric detection.

    PubMed

    Scancar, Janez; Milacic, Radmila

    2002-05-01

    A new analytical procedure using an anion-exchange separation support based on convective-interaction media (CIM) was developed for the speciation of chromium. The separation of Cr(VI) was performed on a weak anion-exchange CIM diethylamine (DEAE) fast-monolithic chromatographic disc. Buffer A (0.005 mol dm(-3) TRIS-HCl, pH 8.0) and buffer B (buffer A plus 3 mol dm(-3) NH4NO3) were employed in the separation procedure. The separated chromium species were determined 'off-line' by ETAAS in 0.5 cm3 fractions. The applicability of the CIM DEAE-ETAAS procedure was investigated for the determination of airborne Cr(VI) at a plasma cutting workplace. Aerosols were collected on polycarbonate membrane filters of 8 and 0.4 microm pore size (inhalable and respirable aerosols). Alkaline extraction of filters in a heated ultrasonic bath was applied to leach chromium. Good repeatability of measurement (+/-3.0%) of the alkaline extracts was obtained for Cr(VI). The LOD (3s) was found to be 0.30 microg m(-3) Cr(VI), when 0.25 m3 of air was collected on the filter. The validation of the procedure was performed by spiking filters with Cr(VI) and by the analysis of the standard reference material CRM 545, Cr(VI) in welding dust loaded on a filter. Good recoveries for spiked samples (101-102%) and good agreement between Cr(VI) found and the reported certified value for CRM 545 were obtained. The extracts were also analysed by the FPLC-ETAAS technique. Good agreement between two techniques (r2 = 0.9978) confirmed the reliability of the CIM DEAE-ETAAS procedure developed. The main advantage of the procedure lies in the speed of the chromatographic separation (chromatographic run completed in 15 min). PMID:12081040

  9. Flow injection online spectrophotometric determination of uranium after preconcentration on XAD-4 resin impregnated with nalidixic acid.

    PubMed

    Shahida, Shabnam; Ali, Akbar; Khan, Muhammad Haleem; Saeed, Muhammad Mufazzal

    2013-02-01

    In this work, spectrophotometer was used as a detector for the determination of uranium from water, biological, and ore samples with a flow injection system coupled with solid phase extraction. In order to promote the online preconcentration of uranium, a minicolumn packed with XAD-4 resin impregnated with nalidixic acid was utilized. The system operation was based on U(VI) ion retention at pH 6 in the minicolumn at flow rate of 15.2 mL min(-1). The uranium complex was removed from the resin by 0.1 mol dm(-3) HCl at flow rate of 3.2 mL min(-1) and was mixed with arsenazo III solution (0.05 % solution in 0.1 mol dm(-3) HCl, 3.2 mL min(-1)) and driven to flow through cell of spectrophotometer where its absorbance was measured at 651 nm. The influence of chemical (pH and HCl (as eluent and reagent medium) concentration) and flow (sample and eluent flow rate and preconcentration time) parameters that could affect the performance of the system as well as the possible interferents was investigated. At the optimum conditions for 60 s preconcentration time (15.2 mL of sample volume), the method presented a detection limit of 1.1 μg L(-1), a relative standard deviation (RSD) of 0.8 % at 100 μg L(-1), enrichment factor of 30, and a sample throughput of 42 h(-1), whereas for 300 s of the preconcentration time (76 mL of sample volume), a detection limit of 0.22 μg L(-1), a RSD of 1.32 % at 10 μg L(-1), enrichment factor of 150, and a sampling frequency of 11 h(-1) were reported. PMID:22580790

  10. A transient method for measuring the DC streaming potential coefficient of porous and fractured rocks

    NASA Astrophysics Data System (ADS)

    Walker, E.; Glover, P. W. J.; Ruel, J.

    2014-02-01

    High-quality streaming potential coupling coefficient measurements have been carried out using a newly designed cell with both a steady state methodology and a new pressure transient approach. The pressure transient approach has shown itself to be particularly good at providing high-quality streaming potential coefficient measurements as each transient increase or decrease allows thousands of measurements to be made at different pressures to which a good linear regression can be fitted. Nevertheless, the transient method can be up to 5 times as fast as the conventional measurement approaches because data from all flow rates are taken in the same transient measurement rather than separately. Test measurements have been made on samples of Berea and Boise sandstone as a function of salinity (approximately 18 salinities between 10-5 mol/dm3 and 2 mol/dm3). The data have also been inverted to obtain the zeta potential. The streaming potential coefficient becomes greater (more negative) for fluids with lower salinities, which is consistent with existing measurements. Our measurements are also consistent with the high-salinity streaming potential coefficient measurements made by Vinogradov et al. (2010). Both the streaming potential coefficient and the zeta potential have also been modeled using the theoretical approach of Glover (2012). This modeling allows the microstructural, electrochemical, and fluid properties of the saturated rock to be taken into account in order to provide a relationship that is unique to each particular rock sample. In all cases, we found that the experimental data were a good match to the theoretical model.

  11. Selective recovery of minor trivalent actinides from high level liquid waste by R-BTP/SiO2-P adsorbents

    NASA Astrophysics Data System (ADS)

    Sano, Yuichi; Surugaya, Naoki; Yamamoto, Masahiko

    2010-03-01

    Concerning the selective recovery of minor trivalent actinides (MA(III) = Am(III) and Cm(III)) from high level liquid waste (HLLW) by extraction chromatography, adsorption and elution behaviours of MA(III) and fission products (FP) in a nitric acid media were studied using iHex-BTP/SiO2-P adsorbents, which is expected to show high adsorption affinity for MA(III) even in concentrated HNO3 solution, such as HLLW. In the batch experiments, Pd showed strong adsorption on iHex-BTP/SiO2-P adsorbents under any concentration of HNO3. The MA(III) and heavy Ln(III) (Sm(III), Eu(III) and Gd(III)) were also adsorbed at the condition of high HNO3 concentration, but they showed no adsorption under low HNO3concentration. The separation factor for MA(III)/heavy Ln(III) took the maximum value (over 100) at around 1mol/dm3 HNO3. It was difficult to elute MA(III) or heavy Ln(III) selectively by HNO3 from the iHex-BTP/SiO2-P adsorbents degradated by γ-ray irradiation. The chromatographic separation of real HLLW by an iHex-BTP/SiO2-P column showed that MA(III) could be recovered selectively by adjusting the acidity of the feed solution, i.e. HLLW, to 1mol/dm3 and using H2O as eluant. The adsorption of Pd(II) can be decreased by the addition of appropriate complexing reagents, e.g. DTPA, into HLLW without any effects on the MA(III) adsorption.

  12. Removal of nickel from electroplating rinse waters using electrostatic shielding electrodialysis/electrodeionization.

    PubMed

    Dermentzis, Konstantinos

    2010-01-15

    Electrostatic shielding zones made of electrode graphite powder were used as a new type of ionic and electronic current sinks. Because of the local elimination of the applied electric field, voltage and current within the zones, ions are led inside them and accumulate there. The current sinks were implemented in electrostatic shielding electrodialysis of a simulated nickel plating rinse water containing 100 mg L(-1) nickel and electrodeionization of a 0.001 M NiSO(4) solution with simultaneous electrochemical regeneration of the ion exchange resin beds. Pure water was obtained with a Ni(2+) ion concentration of less than 0.1 mg L(-1) at a flow rate of 2.02 x 10(-4)dm(3)s(-1) diluate stream and a current density of 30 Am(-2). PMID:19766388

  13. Interaction Mode between Inclusion Complex of Vitamin K3 with γ- Cyclodextrin and Herring-Sperm DNA.

    PubMed

    Tang, Yan; Cai, Li; Xue, Kang; Wang, Chunling; Xiong, Xiaoli

    2016-05-01

    Methods including spectroscopy, electronic chemistry and thermodynamics were used to study the inclusion effect between γ-cyclodextrin (CD) and vitamin K3(K3), as well as the interaction mode between herring-sperm DNA (hsDNA) and γ-CD-K3 inclusion complex. The results from ultraviolet spectroscopic method indicated that VK3 and γ-CD formed 1:1 inclusion complex, with the inclusion constant Kf = 1.02 × 10(4) L/mol, which is based on Benesi-Hildebrand's viewpoint. The outcomes from the probe method and Scatchard methods suggested that the interaction mode between γ-CD-K3 and DNA was a mixture mode, which included intercalation and electrostatic binding effects. The binding constants were K (θ)25°C = 2.16 × 10(4) L/mol, and K(θ)37°C = 1.06 × 10(4) L/mol. The thermodynamic functions of the interaction between γ-CD-K3 and DNA were ΔrHm(θ) = -2.74 × 10(4) J/mol, ΔrSm(θ) = 174.74 J·mol(-1)K(-1), therefore, both ΔrHm(θ) (enthalpy) and ΔrSm(θ) (entropy) worked as driven forces in this action. PMID:27057789

  14. [Annual change of phytoplankton ecological features in Fangchenggang Bay of Guangxi, South China].

    PubMed

    Zhuang, Jun-Lian; Xu, Ming-Ben; Zhang, Rong-Can; Chen, Bo

    2011-05-01

    In March, June, September, and December 2007, investigations were conducted on the species composition, dominant species, community structure, and abundance distribution of phytoplankton in the Fangchenggang Bay of Guangxi. Based on the investigation data, the phytoplankton abundance, biotic index, and their correlations with environmental factors were analyzed. A total of 138 species of 54 genera were identified, among which, 112 species belonged to 37 genera of diatoms, 21 species belonged to 12 genera of dinoflagellates, 2 species belonged to chrysophyta, 2 species belonged to chlorophyta, and 1 species belonged to cyanophyta. In whole year, the dominant species was Skeletonema costatum. The species number had a trend decreasing from the outer to the inner of the Bay and from spring to winter, while the cell abundance was decreased from the inner to the outer of the Bay. There was an obvious annual change in the cell abundance, being the highest (151.39 x 10(4) cells x dm(-3)) in summer (June) and the lowest (0.35 x 10(4) cells x dm(-3)) in winter (December). In spring, both the diversity and the species number were higher. Correlation analysis demonstrated that the distribution of phytoplankton community had definite correlations with water nutrient content, temperature and salinity. At the observation stations 1 and 2 in west Bay, due to the effects of Fangcheng River runoff and hydrodynamic forces such as tide, water salinity was lower and nutrient content was higher, and accordingly, S. costatum cells in summer could greatly reproduce, even result in high probability of red tide. PMID:21812311

  15. Electrodialytic Transport Properties of Anion-Exchange Membranes Prepared from Poly(vinyl alcohol) and Poly(vinyl alcohol-co-methacryloyl aminopropyl trimethyl ammonium chloride)

    PubMed Central

    Jikihara, Atsushi; Ohashi, Reina; Kakihana, Yuriko; Higa, Mitsuru; Kobayashi, Kenichi

    2012-01-01

    Random-type anion-exchange membranes (AEMs) have been prepared by blending poly(vinyl alcohol) (PVA) and the random copolymer-type polycation, poly(vinyl alcohol-co-methacryloyl aminopropyl trimethyl ammonium chloride) at various molar percentages of anion-exchange groups to vinyl alcohol groups, Cpc, and by cross-linking the PVA chains with glutaraldehyde (GA) solution at various GA concentrations, CGA. The characteristics of the random-type AEMs were compared with blend-type AEMs prepared in our previous study. At equal molar percentages of the anion exchange groups, the water content of the random-type AEMs was lower than that of the blend-type AEMs. The effective charge density of the random-type AEMs increased with increasing Cpc and reached a maximum value. Further, the maximum value of the effective charge density increased with increasing CGA. The maximum value of the effective charge density, 0.42 mol/dm3, was obtained for the random-type AEM with Cpc = 4.2 mol % and CGA = 0.15 vol %. A comparison of the random-type and blend-type AEMs with almost the same Cpc showed that the random-type AEMs had lower membrane resistance than the blend-type ones. The membrane resistance and dynamic transport number of the random-type AEM with Cpc = 6.0 mol % and CGA = 0.15 vol % were 4.8 Ω cm2 and 0.83, respectively. PMID:24958543

  16. Thermodynamic and structural studies on the complexation of guanidino-appended α-cyclodextrin derivatives with p-nitrophenolate ion

    NASA Astrophysics Data System (ADS)

    Takezawa, Keita; Hirai, Tomoki; Yamamoto, Tatsuyuki; Yoshikiyo, Keisuke

    2016-03-01

    Thermodynamic parameters (ΔG, ΔH, and TΔS) for the complexation of mono(3-deoxy-3-guanidino-altro)-α-cyclodextrin (1) or mono(3-deoxy-3-guanidino)-α-CD (2) with p-nitrophenolate ion were determined by 1H NMR titration experiments in D2O solution containing 0.10 mol dm-3 Na2CO3-NaHCO3 at 298, 308, 318, and 328 K, to investigate the effect of the macro ring flexibility of 1 on the complexation with the planar guest. Both ΔH and TΔS values for the inclusion complexation of 1 with the guest (-39.6 kJ mol-1 and -23.3 kJ mol-1, respectively) decreased more than those for 2 with the guest (-27.6 kJ mol-1 and -10.0 kJ mol-1, respectively). This fact suggested that the degree of freedom of the guest and the flexibility of the macro ring of 1 were decreased by the tight binding of the guest in the manner of induced fit. The existence of anisotropic ring current effect by the guest on the 1H NMR signals for C(3)- and C(5)-H's of 1 confirmed that the molecular rotation of the guest is retarded in the complex of 1 with p-nitrophenolate ion. The molecular orientation of the guest in the inclusion complex with 1 was determined by means of ROESY (rotating-frame overhauser effect spectroscopy) experiment.

  17. A new approach for deriving the solar irradiance from non-flaring solar upper atmosphere plasmas at 2 x 10^4<-T<-2 x 10^7 K

    SciTech Connect

    Colgan, James P; Abdallaf, Jr., Joseph; Fontes, Christopher J; Sherrill, Manolo E; Feldmn, U; Landi, E; Brown, C M; Seely, J F; Doschek, G A; Dammasch, I E

    2008-01-01

    We propose a new approach for deriving the solar irradiance in the X-ray to VUV range due to the emission by solar upper atmosphere plasmas at 2 x 10{sup 4} {le} T {le} 2 x 10{sup 7} K. Our approach is based on new understanding of the properties of the solar upper atmosphere; specifically, the discovery that the majority of emission from the non-flaring solar upper transition region and corona in the temperature range 3 x 10{sup 5} {le} T {le} 3 x 10{sup 6} K arises from isothermal plasmas that have four distinct temperatures: 0.35, 0.9, 1.4 and 3 x 10{sup 6} K. In the lower transition region (2 x 10{sup 4} {le} T {le} 2 x 10{sup 5} K) of coronal holes, quiet regions or active regions, although multithermal and variable in brightness, the shape of emission measure vs. temperature curves is almost constant. Flaring plasmas are for most part isothermal, although their emission measure and temperature continuously change. In this paper we review these recent results and propose a set of simple spectrometers for recording the solar spectrum in several narrow bands. The solar emission measure, average plasma temperature, and composition can be derived using the measured line fluxes. By combining the emission measure and other plasma properties with the output of a suite of atomic physics codes, which are also described here, the solar irradiance in the temperature range 2 x 10{sup 4} {le} T {le} 2 x 10{sup 7} K can be calculated.

  18. Fluorescence-based sensor for Pb(II) using tetra-(3-bromo-4-hydroxyphenyl)porphyrin in liquid and immobilized medium

    NASA Astrophysics Data System (ADS)

    Bozkurt, Serap Seyhan; Ayata, Sevda; Kaynak, Ipek

    2009-05-01

    A new optical sensor for sensing of Pb 2+ in immobilized medium (PVC film) and ethanol medium was developed by using 5,10,15,20-tetra-(3-bromo-4-hydroxyphenyl)porphyrin (TBHPP) synthesized. The sensor-based TBHPP showed a linear response towards Pb 2+ in concentration range from 5 × 10 -6 to 4 × 10 -4 mol L -1 in PVC film and 5 × 10 -6 to 3 × 10 -4 mol L -1 in ethanol medium, with a working pH 7. The detection limit was 2 × 10 -8 and 4 × 10 -8 mol L -1 for Pb 2+ in PVC film and ethanol medium respectively. The response time of Pb 2+ was found as 4 min for PVC film and 2 min for ethanol medium. The sensor developed in two different mediums was used for lead determination in standard soil sample with satisfactory results.

  19. Adenosine 3',5'-monophosphate in relation to inhibition of cervical smooth muscle activity in early pregnant women.

    PubMed

    Norström, A; Bryman, I

    1991-08-01

    Contractile activity was registered in strips of cervical tissue obtained by needle biopsy from women in the first trimester of pregnancy. Dibutyryl cyclic adenosine-3',5'-monophosphate (5 x 10(-6) mol/l), isobutyryl methylxanthine (10(-4) mol/l), and forskolin (10(-5)-10(-4) mol/l), the latter two drugs known to increase the levels of endogenous cAMP, inhibited spontaneous muscle activity. The levels of tissue cAMP were determined in strips during relaxation induced by prostaglandin E2 or purified porcine relaxin and compared with cAMP levels in strips from the same women during contractile activity. Exposure to prostaglandin E2 but not to relaxin was followed by increased levels of cAMP. It is suggested that cAMP has a role as a second messenger in the prostaglandin E2-mediated relaxation of cervical smooth muscle. PMID:1654721

  20. Photocatalytic oxidation of 2,4,6-trichlorophenol in water using a cocurrent downflow contactor reactor (CDCR).

    PubMed

    Ochuma, Idoko J; Fishwick, Robert P; Wood, Joseph; Winterbottom, J Mike

    2007-06-18

    The heterogeneous photocatalytic oxidation of aqueous solutions of 2,4,6-trichlorophenol (2,4,6-TCP) as a model pollutant in industrial wastewater has been carried out in a pilot scale cocurrent downflow contactor reactor (CDCR). The reactions were carried out in the presence of Ultra-Violet radiation, O(2) and TiO(2) photocatalyst (VP Aeroperl P25/20). The TiO(2) was characterized by Dynamic Vapour Sorption (DVS) technique giving specific surface area and surface energy of 46.06 m(2)g(-1) and 80.12 mJ m(-2), respectively. The CDC reactor was fitted with an internally and vertically mounted 1.0 kW or 2.0 kW UV lamp. The reactions were carried out at 50 degrees C and 1 bar, with the reactor being operated in closed loop recycle mode and suspended photocatalyst being re-circulated. The CDC reactor, a device of very high mass transfer efficiency giving unusually large gas hold-up of approximately 50%, was operated with oxygen mass transfer and dissolution in the zone above the UV lamp (high mass transfer zone) and along and around the UV lamp housing (reaction zone). Under optimized reaction conditions, 100% conversion of 2,4,6-TCP was achieved in 180 min using 15 dm(3) solutions with initial concentration of 120 mg dm(-3). A combination of TiO(2) photocatalyst, UV irradiation and oxidant was observed to give the most rapid photodegradation and photomineralization of the 2,4,6-TCP in comparison with irradiation only. Using the 1 kW or 2 kW UV lamps, conversion of 100 mg dm(-3) of 2,4,6-TCP after 30 min was 62.51% and 90.71%, respectively, with initial reaction rates of 1.33 x 10(-5) and 4.22 x 10(-5) mol min(-1), respectively, and rate constants 0.0046 and 0.29 min(-1), respectively. PMID:17320288

  1. Final report on international comparison EURO.QM-S5/1166: Carbon dioxide mixtures in nitrogen

    NASA Astrophysics Data System (ADS)

    Dias, Florbela A.; Baptista, Gonçalo; Rakowska, Agata; Chye, Teo Chin; Beng Keat, Teo; Cieciora, Darek; Augusto, Cristiane; Lin, Tsai-Yin; Niederhauser, Bernhard; Fükö, Judit; Sinweeruthai, Ratirat; Johri, Prabha; Akcadag, Fatma; Tarhan, Tanil; van der Veen, Adriaan M. H.; van Wijk, Janneke

    2013-01-01

    This supplementary comparison is designed to test the capabilities of the participants to measure and certify carbon dioxide in nitrogen, and to provide supporting evidence for the CMCs of institutes for carbon dioxide. Indeed this comparison aims to demonstrate the capabilities of IPQ in the production of primary gas mixtures of carbon dioxide in nitrogen and for the participant laboratories to demonstrate their capabilities on certifying primary gas mixtures of percent levels of carbon dioxide in nitrogen. Moreover, a number of NMIs had already participated in the key comparison CCQM-K52, but in a lower range. This EURAMET comparison offers an opportunity to the laboratories to submit CMC in a higher range. In this comparison the laboratories analysed the gas mixtures that are gravimetrically produced and analyzed by IPQ. Each cylinder had its own reference value calculated from the gravimetric preparation. The pressure in the cylinders was approximately 10 MPa; aluminum cylinders of 5 dm3 nominal volume were used. This comparison provides evidence in support of CMCs for carbon dioxide within the range of 1.0 × 10-2 mol/mol to 20.0 × 10-2 mol/mol in a nitrogen/air balance. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by EURAMET, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

  2. Separating chemical and excluded volume interactions of polyethylene glycols with native proteins: Comparison with PEG effects on DNA helix formation.

    PubMed

    Shkel, Irina A; Knowles, D B; Record, M Thomas

    2015-09-01

    Small and large PEGs greatly increase chemical potentials of globular proteins (μ2), thereby favoring precipitation, crystallization, and protein-protein interactions that reduce water-accessible protein surface and/or protein-PEG excluded volume. To determine individual contributions of PEG-protein chemical and excluded volume interactions to μ2 as functions of PEG molality m3 , we analyze published chemical potential increments μ23  = dμ2/dm3 quantifying unfavorable interactions of PEG (PEG200-PEG6000) with BSA and lysozyme. For both proteins, μ23 increases approximately linearly with the number of PEG residues (N3). A 1 molal increase in concentration of PEG -CH2 OCH2 - groups, for any chain-length PEG, increases μBSA by ∼2.7 kcal/mol and μlysozyme by ∼1.0 kcal/mol. These values are similar to predicted chemical interactions of PEG -CH2 OCH2 - groups with these protein components (BSA ∼3.3 kcal/mol, lysozyme ∼0.7 kcal/mol), dominated by unfavorable interactions with amide and carboxylate oxygens and counterions. While these chemical effects should be dominant for small PEGs, larger PEGS are expected to exhibit unfavorable excluded volume interactions and reduced chemical interactions because of shielding of PEG residues in PEG flexible coils. We deduce that these excluded volume and chemical shielding contributions largely compensate, explaining why the dependence of μ23 on N3 is similar for both small and large PEGs. PMID:25924886

  3. Possible role of organic peroxides in the detection of irradiated food

    NASA Astrophysics Data System (ADS)

    Shengchu, Qi; Jilan, Wu; Yan, Zhu

    1993-07-01

    In order to determine the level of organic peroxides induced by autooxidation, random sampling of pork has been performed with ˜ 300 analytical data. The organic peroxide content in unirradiated pork has been estimated as (5.4±3.0)X10 -5mol.kg -1. The dependence of yield of peroxide in pork, minced meat and braised chicken on absorbed dose has been investigated. For killing trichinae 0.5˜1 kGy is used, the quantity of peroxide in pork will be 2X10 -4mol.kg -1 (or 4X10 -4 mol.kg -1 for 1 kGy), which is 3.7˜7.4 times greater than the background. If 3 kGy is used to eliminate Samonella, the quantity of peroxides in pork will be 1.3X10 -3mol.kg -1., which approaches 24 times greater than the average value of background. When minced meat was irradiated in the presence of air, a chain reaction takes place with G (organic peroxides) value 30.2. Radiation processing dose of braised chicken for shelf-life extension is ˜ 9kGy, organic peroxide content in braised chicken fat is 32.5X10 -4mol.kg -1, which is about 14.7 times greater than average value (2.2X10 -4mol.kg -1) in unirradiated one. Applying peroxide method to qualitatively detect the irradiated food containing fat is satisfactory. Recombining with measuring ESR signal of irradiated bone will cause the method of detection more accurate and perfect.

  4. In search of nuclear fusion in electrolytic cells and in metal/gas systems

    NASA Astrophysics Data System (ADS)

    McCracken, D. R.; Paquette, J.; Boniface, H. A.; Graham, W. R. C.; Johnson, R. E.; Briden, N. A.; Cross, W. G.; Arneja, A.; Tennant, D. C.; Lone, M. A.; Buyers, W. J. L.; Chambers, K. W.; McIlwain, A. K.; Attas, E. M.; Dutton, R.

    1990-06-01

    It has been reported recently in the literature that unexpected thermal and nuclear effects (production of excess heat, neutrons, γ-rays, and tritium) can occur during the electrolysis of heavy water at palladium or titanium electrodes, or during temperature and pressure cycling of the titanium/deuterium gas system. We have attempted to reproduce some of these experiments. A variety of electrochemical cells having palladium cathodes in the form of wires, tubes, sheets, and rods have been used to electrolyze heavy water containing 0.1 mol.dm-3 LiOH, 0.1 mol.dn-3 LiOD or 0.5 mol.dm-3 D3PO4. Current densities of up to 200 mA.cm-2 were applied. The mass of the palladium cathodes covered the range from 1-40 grams and the surface area varied from 8-140 cm2. Neutron detection systems with low constant backgrounds were used to search for neutron emission during electrolysis. These included3He- and10BF3-based detectors. After running some of the cells for more than 30 days, no neutron emission above background could be detected. This puts upper limits of 0.5 s-1 and 2×10-23 fus. D-D.s-1 on the neutron emission and the fusion rate, respectively. A sensitive and accurate heat-flow calorimeter was built and used to monitor the energy balance of some of the cells during electrolysis. No unexpected heat effects were observed. This puts an upper limit of 0.13 W.cm-3 on the specific excess power. No enrichment of the electrolyte in tritium was evident after electrolysis. Experiments were also performed with the titanium/ deuterium gas system. These consisted of exposing titanium metal to a deuterium gas pressure of 40 atmospheres, lowering the temperature to -196°C, releasing the pressure and gradually warming the titanium to room temperature. No neutron emission above background was observed during these experiments, which puts upper limits of 0.5 s-1 and 4×10-25 fus.D-D.s-1 on the neutron emission and fusion rate, respectively.

  5. Exploring the first steps in core-shell electrocatalyst preparation: in situ characterization of the underpotential deposition of Cu on supported Au nanoparticles.

    PubMed

    Price, Stephen W T; Speed, Jonathon D; Kannan, Prabalini; Russell, Andrea E

    2011-12-01

    The underpotential deposition (upd) of a Cu shell on a non-Pt nanoparticle core followed by galvanic displacement of the Cu template shell to form core-shell electrocatalyst materials is one means by which the Pt-based mass activity targets required for commercialization of PEM fuel cells may be reached. In situ EXAFS measurements were conducted at both the Au L(3) and the Cu K absorption edges during deposition of Cu onto a carbon-supported Au electrocatalyst to study the initial stages of formation of such a core-shell electrocatalyst. The Au L(3) EXAFS data obtained in 0.5 mol dm(-3) H(2)SO(4) show that the shape of the Au core is potential dependent, from a flattened to a round spherical shape as the Cu upd potential is approached. Following the addition of 2 mmol dm(-3) Cu, the structure was also measured as a function of the applied potential. At +0.2 V vs Hg/Hg(2)SO(4), the Cu(2+) species was found to be a hydrated octahedron. As the potential was made more negative, single-crystal studies predict an ordered bilayer of sulfate anions and partially discharged Cu ions, followed by a complete/uniform layer of Cu atoms. In contrast, the model obtained by fitting the Au L(3) and Cu K EXAFS data corresponds first to partially discharged Cu ions deposited at the defect sites in the outer shell of the Au nanoparticles at -0.42 V, followed by the growth of clusters of Cu atoms at -0.51 V. The absence of a uniform/complete Cu shell, even at the most negative potentials investigated, has implications for the structure, and the activity and/or stability, of the core-shell catalyst that would be subsequently formed following galvanic displacement of the Cu shell. PMID:22032178

  6. Reductive dehalogenation of 5-bromouracil by aliphatic organic radicals in aqueous solutions; electron transfer and proton-coupled electron transfer mechanisms

    NASA Astrophysics Data System (ADS)

    Matasović, Brunislav; Bonifačić, Marija

    2011-06-01

    Reductive dehalogenation of 5-bromouracil by aliphatic organic radicals CO2-rad , rad CH 2OH, rad CH(CH 3)OH, and rad CH(CH 3)O - have been studied in oxygen free aqueous solutions in the presence of organic additives: formate, methanol or ethanol. For radicals production 60Co γ-radiolysis was employed and the yield of bromide was measured by means of ion chromatography. Both radical anions have reducing potential negative enough to transfer an electron to BrU producing bromide ion and U rad radical. High yields of bromide have been measured increasing proportional to the concentration of the corresponding organic additives at a constant dose rate. This is characteristic for a chain process where regeneration of radical ions occurs by H-atom abstraction by U rad radical from formate or ethanol. Results with the neutral radicals conformed earlier proposition that the reduction reaction of α-hydroxyalkyl radicals proceeds by the proton-coupled electron transfer mechanism ( Matasović and Bonifačić, 2007). Thus, while both rad CH 2OH and rad CH(CH 3)OH did not react with BrU in water/alcohol solutions, addition of bicarbonate and acetate in mmol dm -3 concentrations, pH 7, brought about chain debromination to occur in the case of rad CH(CH 3)OH radical as reactant. Under the same conditions phosphate buffer, a base with higher bulk proton affinity, failed to have any influence. The results are taken as additional proofs for the specific complex formation of α-hydroxyalkyl radicals with suitable bases which enhances radicals' reduction potential in comparison with only water molecules as proton acceptors. Rate constants for the H-atom abstraction from ethanol and formate by U rad radicals have been estimated to amount to about ≥85 and 1200 dm 3 mol -1 s -1, respectively.

  7. Understanding the bioavailability and sequestration of different metal cations in the presence of a biodegradable chelant S,S-EDDS in biological fluids and natural waters.

    PubMed

    Bretti, Clemente; Cigala, Rosalia Maria; De Stefano, Concetta; Lando, Gabriele; Sammartano, Silvio

    2016-05-01

    Ethylenediamine-N,N'-disuccinic acid is a biodegradable alternative to EDTA, therefore its use for the sequestration of Ca(2+), Sn(2+), Cu(2+), Zn(2+) and Fe(3+) is analyzed. New data on its binding ability towards these cations were obtained with potentiometric, voltammetric and calorimetric measurements at different ionic strengths and at T = 298.15 K. Real multi-component fluids, namely fresh water, urine, sea water, saliva and blood plasma were chosen as case studies to evaluate the sequestering ability of EDDS in comparison with EDTA. Speciation diagrams were drawn in selected conditions, considering all interactions among the "natural" components of the fluid and those studied in this work, EDDS and EDTA (cL = 1 mmol dm(-3)) as sequestering agents and the cited metal cations (cM ∼ 10(-5) mol dm(-3)). The comparison of the sequestering ability of EDDS and EDTA is done using pM and pL0.5. In blood plasma the plasma mobilizing index was adopted. It was found that EDDS is a good alternative to EDTA, which tends to bind Ca(2+) and Mg(2+) more than EDDS. In particular, EDTA cannot be used as a sequestrant for Sn(2+) when cCa > cEDTA. EDDS is more efficient than EDTA at pH < 8, particularly in urine, where carbonate is absent. In sea water, the sequestering ability of EDDS towards Fe(3+) is higher than that of EDTA. In blood plasma, the PMI of EDDS towards Cu(2+) is higher than that of EDTA. Thermodynamic information, in terms of ΔH and ΔS, for the protonation and metal complex formation reactions are reported. PMID:26921587

  8. Electrooxidation and Determination of Dopamine Using a Nafion®-Cobalt Hexacyanoferrate Film Modified Electrode

    PubMed Central

    Castro, Suely S. L.; Mortimer, Roger J.; de Oliveira, Marcelo F.; Stradiotto, Nelson R.

    2008-01-01

    The electrocatalysis of dopamine has been studied using a cobalt hexacyanoferrate film (CoHCFe)-modified glassy carbon electrode. Using a rotating disk CoHCFe-modified electrode, the reaction rate constant for dopamine was found to be 3.5 × 105 cm3 mol-1 s-1 at a concentration of 5.0 × 10-5 mol L-1. When a Nafion® film is applied to the CoHCFe-modified electrode surface a high selectivity for the determination of dopamine over ascorbic acid was obtained. The analytical curve for dopamine presented linear dependence over the concentration range from 1.2 × 10-5 to 5.0 × 10-4 mol L-1 with a slope of 23.5 mA mol-1 L and a linear correlation coefficient of 0.999. The detection limit of this method was 8.9 × 10-6 mol L-1 and the relative standard deviation for five measurements of 2.5 × 10-4 mol L-1 dopamine was 0.58%.

  9. Interaction with biomacromolecules and antiproliferative activities of Mn(II), Ni(II), Zn(II) complexes of demethylcantharate and 2,2'-bipyridine.

    PubMed

    Zhang, Fan; Lin, Qiu-Yue; Hu, Wan-Li; Song, Wen-Ji; Shen, Shu-Ting; Gui, Pan

    2013-06-01

    Three new transition metal complexes [Mn2(DCA)2(bipy)2]·5H2O (1), [M2(DCA)2(bipy)2(H2O)]·10H2O(M=Ni(II)(2);Zn(II)(3)), (DCA=demethylcantharate, 7-oxabicyclo[2,2,1]heptane-2,3-dicarboxylate, C8H8O5) were synthesized and characterized by elemental analysis, molar conductance, infrared spectra and X-ray diffraction techniques. Each metal ion was six-coordinated in complexes. Complex 1 has a Mn2O2 center. Complexes 2 and 3 have asymmetric binuclear structure. Great amount of intermolecular hydrogen-bonding and π-π(*) stacking interactions were formed in these complex structures. The DNA-binding properties of complexes were investigated by electronic absorption spectra and viscosity measurements. The DNA binding constants Kb/(Lmol(-1)) were 1.71×10(4) (1), 2.62×10(4) (2) and 1.59×10(4) (3) at 298 K. The complexes could quench the intrinsic fluorescence of bovine serum albumin (BSA) strongly through static quenching. The protein binding constants Ka/(L mol(-1)) were 7.27×10(4) (1), 4.55×10(4) (2) and 7.87×10(4) L mol(-1) (3) and binding site was one. The complexes bind more tightly with DNA and BSA than with ligands. Complexes 1 and 3 had stronger inhibition ratios than Na2(DCA) against human hepatoma cells (SMMC-7721) lines and human gastric cancer cells (MGC80-3) lines in vitro. Complex 3 showed the strongest antiproliferative activity against SMMC-7721 (IC50=29.46±2.12 μmol L(-1)) and MGC80-3 (IC50=27.02±2.38 μmol L(-1)), which shows potential in anti-cancer drug development. PMID:23557779

  10. TEMPO-functionalized zinc phthalocyanine: synthesis, magnetic properties, and its utility for electrochemical sensing of ascorbic acid.

    PubMed

    Korkut, Sibel Eken; Akyüz, Duygu; Özdoğan, Kemal; Yerli, Yusuf; Koca, Atıf; Şener, M Kasım

    2016-02-21

    Zinc(ii) phthalocyanine (TEMPO-ZnPc), peripherally functionalized with 2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO) radicals is synthesized and its magneto structural and electrochemical behaviors are investigated. TEMPO-ZnPc shows multi-electron ring based reduction reactions and a TEMPO based oxidation reaction. Spectroelectrochemical measurements support these peak assignments. TEMPO-ZnPc is tested as a homogeneous and heterogeneous ascorbic acid (AA) sensor. Disappearance of TEMPO-ZnPc based reduction processes and the observation of new waves at around 0 and 1.20 V with respect to increasing AA concentration indicate the interaction of TEMPO-ZnPc with AA and usability of the complex as an electrochemical AA sensor. For practical usage as heterogeneous electrocatalysts for AA sensing, a glassy carbon electrode (GCE) is coated with TEMPO-ZnPc (GCE/TEMPO-ZnPc) and this modified electrode is tested as a heterogeneous AA sensor. The redox peak of GCE/TEMPO-ZnPc at 0.81 V decreases the peak current while a new wave is observed at 0.65 V during the titration of the electrolyte with AA. GCE/TEMPO-ZnPc sense AA with 1.75 × 10(-6) mol dm(-3) LOD with a sensitivity of 1.89 × 10(3) A cm mol(-1). PMID:26766137

  11. Ni-Supported Pd Nanoparticles with Ca Promoter: A New Catalyst for Low-Temperature Ammonia Cracking

    PubMed Central

    Polanski, Jaroslaw; Bartczak, Piotr; Ambrozkiewicz, Weronika; Sitko, Rafal; Siudyga, Tomasz; Mianowski, Andrzej; Szade, Jacek; Balin, Katarzyna; Lelątko, Józef

    2015-01-01

    In this paper we report a new nanometallic, self-activating catalyst, namely, Ni-supported Pd nanoparticles (PdNPs/Ni) for low temperature ammonia cracking, which was prepared using a novel approach involving the transfer of nanoparticles from the intermediate carrier, i.e. nano-spherical SiO2, to the target carrier technical grade Ni (t-Ni) or high purity Ni (p-Ni) grains. The method that was developed allows a uniform nanoparticle size distribution (4,4±0.8 nm) to be obtained. Unexpectedly, the t-Ni-supported Pd NPs, which seemed to have a surface Ca impurity, appeared to be more active than the Ca-free (p-Ni) system. A comparison of the novel PdNPs/Ni catalyst with these reported in the literature clearly indicates the much better hydrogen productivity of the new system, which seems to be a highly efficient, flexible and durable catalyst for gas-phase heterogeneous ammonia cracking in which the TOF reaches a value of 2615 mmolH2/gPd min (10,570 molNH3/molPd(NP) h) at 600°C under a flow of 12 dm3/h (t-Ni). PMID:26308929

  12. Effect of diacetylrhein on the phagocytosis of polymorphonuclear leucocytes and its influence on the biosynthesis of hyaluronate in synovial cells.

    PubMed

    Schöngen, R N; Giannetti, B M; van de Leur, E; Reinards, R; Greiling, H

    1988-05-01

    1. The influence of diacetylrhein on the luminol-induced chemiluminescence of zymosan-activated polymorphonuclear leucocytes (PMNL) was investigated. At a concentration of 4 x 10(-5) mol/l diacetylrhein an inhibition of about 40% was found. 2. A model for the degradation of hyaline cartilage by frustrated phagocytosis was developed, in which human polymorphonuclear leucocytes cause a release of glycosaminoglycan peptides from hyaline cartilage slices (bovine nasal septum). We observed a 20% inhibition of this release at a concentration of 10(-4) mol/l diacetylrhein. 3. Human synovial fibroblasts synthesize the glycosaminoglycan hyaluronate. As a parameter of the rate of hyaluronate synthesis we measured the incorporation of 14C-glucosamine into hyaluronate. At a concentration of 2 x 10(-4) mol/l diacetylrhein a 4-fold increase of 14C-glucosamine incorporation in the membrane fraction of the synovial cells (tryptic fraction) and a 1.6-fold elevation of glucosamine release into the medium was measured. The synovial fibroblasts show a higher (1.5-fold) glucose consumption and lactate production in the presence of diacetylrhein (2 x 10(-4) mol/l). PMID:3415721

  13. Association of Eu(III) and Cm(III) With Halophiles

    NASA Astrophysics Data System (ADS)

    Ozaki, T.; Takenaka, Y.; Ohnuki, T.; Gillow, J. B.; Francis, A. J.

    2003-12-01

    Halophiles live in high ionic strength brine. The mechanisms of metal association with these microorganisms are poorly understood. In this study, we determined the distribution of Eu(III) and Cm(III) on halophiles, Halomonas sp. (WIPP1A) which was isolated from the Waste Isolation Pilot Plant (WIPP) repository in Carlsbad, US., Halomonas elongata (ATCC33173), Halobacterium salinarum (ATCC19700), and Halobacterium halobium (ATCC43214) and examined the coordination environment of Eu(III) adsorbed on the cells by time-resolved laser-induced fluorescence spectroscopy (TRLFS). The cells of Halomonas sp. and H. elongata were grown in media containing 10 - 15 w/v% and 3.5 - 30 w/v% NaCl, respectively. Halobacterium salinarum and H. halobium were grown in media containing 25 w/v% NaCl. The logarithmic distribution coefficient (log Kd) was measured by using the cells at the late exponential phase. After washing the cells with the same concentrations of NaCl, the cells were mixed with 1x10-6 mol dm-3 Eu(III) and 1x10-8 mol dm-3 Cm(III) at pH 5 in the same concentrations of NaCl and log Kd of Eu(III) and Cm(III) was determined. For Halomonas sp. and H. elongata, log Kd was determined as a function of NaCl concentrations. The coordination environment of Eu(III) adsorbed on the cells was estimated by TRLFS. For TRLFS measurements, samples were prepared by adding cells to a solution of 1x10-3 mol dm-3 Eu(III) with the same concentrations of NaCl as the culture media. For Halomonas sp. and H. elongata, log Kd of Cm(III) was apparently larger than that of Eu(III) at all the NaCl concentrations examined. On the other hand, log Kd of Eu(III) and Cm(III) for H. salinarum and H. halobium was almost identical. Our previous study demonstrated that non-halophiles, Chlorella vulgaris, Bacillus subtilis, and Pseudomonas fluorescens show no preferences between these elements. Chemical properties of Eu(III) and Cm(III) are almost identical. Our findings suggest that the difference in log Kd

  14. Interactions of thioflavin T with serum albumins: Spectroscopic analyses

    NASA Astrophysics Data System (ADS)

    Sen, Priyankar; Fatima, Sadaf; Ahmad, Basir; Khan, Rizwan Hasan

    2009-09-01

    The interaction of thioflavin T (ThT) with serum albumins from four different mammalian species i.e. human, bovine, porcine and rabbit, has been investigated by circular dichroism (CD), fluorescence spectroscopy and ITC. The binding constant ( K) for HSA was found to be 9.9 × 10 4 M -1, 4.3 × 10 4 M -1 for RSA, 1.07 × 10 4 M -1 for PSA and 0.3 × 10 4 M -1 for BSA and the number of binding sites ( n) were 1.14, 1.06, 0.94 and 0.8, respectively, which is very significant. By using unfolding pathway of HSA in the presence of urea, domain II of HSA has been assigned to possess binding site of ThT. Its binding constant is comparable to many drugs that bind at domain II of HSA, like salicylate, warfarin, digitoxin, etc. Acting force between HSA and ThT is showing that both hydrophobic and electrostatic forces have contributed for the interaction. Δ Gbinding, Δ H and Δ S were calculated to be -28.46 kJ mol -1, -3.50 kJ mol -1 and 81.04 J K -1 mol -1, respectively. The data described here will help to increase our understanding about the interaction of ThT with native proteins. The results also indicate that care must be taken while using ThT as a probe for detecting amyloid fibrils.

  15. Effects of chemical cues on larval survival, settlement and metamorphosis of abalone Haliotis asinina

    NASA Astrophysics Data System (ADS)

    Wang, Xiaobing; Bai, Yang; Huang, Bo

    2010-11-01

    Low larval survival, poor settlement, and abnormal metamorphosis are major problems in seed production of donkey-ear abalone Haliotis asinina. We examined the effects of chemical cues including epinephrine, nor-epinephrine, and serotonin on larval survival, settlement, and metamorphosis in order to determine the possibility of using these chemicals to induce the problems. The results show that epinephrine could enhance metamorphosis rate at 10-6 mol/L only but higher concentrations (10-3-10-4 mol/L); and nor-epinephrine could inhibit the performance significantly, and serotonin could increase significantly the performance at a wide-range concentration (10-3-10-6 mol/L). Treatment with serotonin at 10-5 mol/L for 72 hours resulted in the highest settlement rate (42.2%) and survival rate (49.3%), while at 10-4 mol/L for 72 hours resulted in the highest metamorphosis rate (38.8%). Therefore, serotonin may be used as a fast metamorphosis inducer in abalone culture.

  16. Microbial Siderophores

    NASA Astrophysics Data System (ADS)

    Budzikiewicz, Herbert

    Iron is of great importance for many metabolic processes since the redox potential between its two valence states Fe2+ and Fe3+ lies within the range of physiological processes. Actually, iron is not a rare element, it is fourth in abundance in the earth crust, but it is not readily available for microorganisms. In the soil ferric oxide hydrates are formed at pH values around seven and the concentration of free Fe3+ is at best 10-17 mol/dm3 while about 10-6 mol/dm3 would be needed. In living organisms iron is usually strongly bound to peptidic substances such as transferrins. To increase the supply of soluble iron microorganisms other than those living in an acidic habitat may circumvent the problem by reduction of Fe3+ to Fe2+ (182), which seems to be of major importance for marine phytoplankton (151); see also amphiphilic marine bacteria (Sect.2.8) and Fe2+ binding ligands (Sect. 7) below. An important alternative is the production of Fe3+ chelating compounds, so-called siderophores. Siderophores are secondary metabolites with masses below 2,000 Da and a high affinity to Fe3+. Small iron-siderophore complexes can enter the cell via unspecific porins, larger ones need a transport system that recognizes the ferri-siderophore at the cell surface. In the cell, iron is released mostly by reduction to the less strongly bound Fe2+ state (137), and the free siderophore is re-exported ("shuttle mechanism"); for a modified shuttle system see pyoverdins (Sect. 2.1) and amonabactins (Sect. 2.7). Rarely the siderophore is degraded in the periplasmatic space as, e.g. enterobactin (Sect. 2.7). Alternatively Fe3+ is transferred at the cell surface from the ferri-siderophore to a trans-membrane transport system ("taxi mechanism"). A probably archaic and unspecific variety of the taxi mechanism comprises the reduction of Fe3+ at the cell surface (see ferrichrome A, Sect. 2.6 (99, 105)). The terms "shuttle" and "taxi mechanism" were coined by Raymond and Carrano (296).

  17. Pulse and gamma radiolysis studies of 3-sulfo propyl methacrylate in aqueous solutions

    NASA Astrophysics Data System (ADS)

    Panda, Anjali; Mohan, Hari; Sabharwal, S.

    2001-10-01

    Radiation induced polymerization of 3-sulfo propyl methacrylate (SPMA) in aqueous solution (10 wt%) has been studied by steady state and pulse radiolysis techniques. The effect of radiation characteristics such as irradiation dose, dose rate and the presence of crosslinking agent on the gel formation of SPMA monomer has been investigated. In N 2 -saturated solution, the gel formation doses for SPMA were found to be 70 and 258 Gy at dose rates of 1.2 and 5 kGy h -1, respectively. The swelling ratio results showed that the gel obtained at a constant dose of 0.8 kGy dose swells ˜630 times of its dry weight at a dose rate of 5 kGy h -1 whereas it is 394 times of its dry weight for the dose rate 1.2 kGy h -1. The reactions of the primary radicals of water radiolysis such as e aq-, H-atom, OH radical, O rad - , and some oxidizing radicals like N3rad , Cl2rad - , SO4rad - and reducing species like CO 2rad - with SPMA have been studied using pulse radiolysis technique. The results show that the reaction of e aq-, H-atom and OH radicals with SPMA are in the diffusion controlled limit with their respective bimolecular rate constant values being 8.6×10 9, 2×10 9 and 1.5×10 10 dm 3 mol -1 s -1. The radical anion, SPMA rad - , ( λmax=280 nm) is observed to undergo fast protonation forming H-adduct, SPMA—H rad , ( λmax=310 nm) with a p Ka value of 9.1. Cl 2rad - reacts with a bimolecular rate constant of 3.5×10 7 dm 3 mol -1 s -1 forming solute radical cation ( λmax=265 nm). One-electron oxidation and reduction potentials for SPMA/SPMA rad + and SPMA/SPMA rad - couples are estimated to be more than +1.6 and less than -1.9 V, respectively.

  18. Electrochromic and colorimetric properties of nickel(II) oxide thin films prepared by aerosol-assisted chemical vapor deposition.

    PubMed

    Sialvi, Muhammad Z; Mortimer, Roger J; Wilcox, Geoffrey D; Teridi, Asri Mat; Varley, Thomas S; Wijayantha, K G Upul; Kirk, Caroline A

    2013-06-26

    Aerosol-assisted chemical vapor deposition (AACVD) was used for the first time in the preparation of thin-film electrochromic nickel(II) oxide (NiO). The as-deposited films were cubic NiO, with an octahedral-like grain structure, and an optical band gap that decreased from 3.61 to 3.48 eV on increase in film thickness (in the range 500-1000 nm). On oxidative voltammetric cycling in aqueous KOH (0.1 mol dm(-3)) electrolyte, the morphology gradually changed to an open porous NiO structure. The electrochromic properties of the films were investigated as a function of film thickness, following 50, 100, and 500 conditioning oxidative voltammetric cycles in aqueous KOH (0.1 mol dm(-3)). Light modulation of the films increased with the number of conditioning cycles. The maximum coloration efficiency (CE) for the NiO (transmissive light green, the "bleached" state) to NiOOH (deep brown, the colored state) electrochromic process was found to be 56.3 cm(2) C(-1) (at 450 nm) for films prepared by AACVD for 15 min followed by 100 "bleached"-to-colored conditioning oxidative voltammetric cycles. Electrochromic response times were <10 s and generally longer for the coloration than the bleaching process. The films showed good stability when tested for up to 10 000 color/bleach cycles. Using the CIE (Commission Internationale de l'Eclairage) system of colorimetry the color stimuli of the electrochromic NiO films and the changes that take place on reversibly oxidatively switching to the NiOOH form were calculated from in situ visible spectra recorded under electrochemical control. Reversible changes in the hue and saturation occur on oxidation of the NiO (transmissive light green) form to the NiOOH (deep brown) form, as shown by the track of the CIE 1931 xy chromaticity coordinates. As the NiO film is oxidized, a sharp decrease in luminance was observed. CIELAB L*a*b* coordinates were also used to quantify the electrochromic color states. A combination of a low L* and positive a

  19. (2Z,4E)-1-(5-Fluoro-2-hy­droxy­phen­yl)-5-(4-fluoro­phen­yl)-3-hy­droxy­penta-2,4-dien-1-one

    PubMed Central

    Chen, Jing-Wei; He, Zhuo; Wu, Zhen; Fang, Mei-Juan; Fang, Hua

    2014-01-01

    In the title mol­ecule, C17H12F2O3, the dihedral angle between the benzene rings is 8.6 (2)°. In the crystal, two pairs of O—H⋯O hydrogen bonds connect the mol­ecules into inversion dimers. In addition, weak C—H⋯F hydrogen bonds link the dimers into a two-dimensional network parallel to (10-4). The carbonyl O atom is an acceptor for two weak intra­molecular hydrogen bonds. PMID:24527017

  20. Interaction of ICT receptor with serum albumins in aqueous buffer

    NASA Astrophysics Data System (ADS)

    Wu, Fang-Ying; Ji, Zhao-Jun; Wu, Yu-Mei; Wan, Xiao-Fen

    2006-06-01

    A novel compound, p-(dimethylamino)benzamido-thiosemicarbazide ( 1), based on intramolecular charge transfer fluorescence was synthesized. In pH 7.4 Tris-HCl buffer, the emission intensity of 1 increased upon the addition of HSA or BSA due to the energy transfer from the protein to 1 and also the hydrophobic microenvironment provided by HSA or BSA. The binding constants between 1 and proteins were 1.41 × 10 5 mol -1 L for HSA and 8.68 × 10 4 mol -1 L for BSA, respectively. There is only one binding site. The interaction between 1 and proteins was further investigated by synchronous fluorescence.

  1. The kinetics and inhibition of p-nitrophenylacetate-hydrolysing esterases in a solitary bee, Megachile rotundata (Fab.).

    PubMed

    Frohlich, D R; Boeker, E A; Brindley, W A

    1990-05-01

    1. The kinetics and inhibition of p-nitrophenylacetate hydrolysis by cytosolic esterases of female alfalfa leafcutting bees, Megachile rotundata (Fab.) was examined. 2. For p-nitrophenylacetate, the Km = 1.24 x 10(-4) M and Vmax = 2.29 x 10(-9) mol/s per mg protein. 3. Regarding four organophosphate insecticides, the mechanism of inhibition in all cases was mixed (competitive and uncompetitive) and, based on inhibition constants, the order of toxicity was naled greater than paraoxon greater than trichlorfon greater than oxydemeton methyl. 4. Comparisons are made to the honey bee, Apis mellifera. PMID:2349807

  2. Potassium channel antagonists and vascular reactivity in stroke-prone spontaneously hypertensive rats.

    PubMed

    Kolias, T J; Chai, S; Webb, R C

    1993-06-01

    The goal of this study was to characterize differences in contractile responsiveness to several potassium channel antagonists in vascular smooth muscle from stroke-prone spontaneously hypertensive rats (SHRSP) and Wistar-Kyoto normotensive rats (WKY). Helically-cut strips of carotid arteries (endothelium removed) from SHRSP and WKY were mounted in muscle baths for measurement of isometric force generation. Contractile responses to tetraethylammonium (10(-4) to 3 x 10(-2) mol/L) and barium (3 x 10(-5) mol/L), blockers of the voltage-dependent and large conductance, calcium activated potassium channels, were greater in carotid arteries from SHRSP than in those from WKY. In contrast, contractile responses to the voltage-dependent potassium channel blockers 3,4-diamino-pyridine (10(-6) to 3 x 10(-3) mol/L) and sparteine (10(-6) to 3 x 10(-2) mol/L) in arteries from SHRSP did not differ from WKY values. Carotid arteries from SHRSP and WKY did not contract to apamin (10(-9) to 10(-6) mol/L), an antagonist of the small conductance, calcium activated potassium channel. Furthermore, relaxation responses to diazoxide (3 x 10(-4) mol/L), an activator of the ATP-sensitive potassium channel, and subsequent contractions to the ATP-sensitive potassium channel blocker glyburide (10(-8) to 3 x 10(-6) mol/L) in arteries from SHRSP did not differ from WKY values. Carotid artery segments from SHRSP were more sensitive to the contractile effects of elevated potassium than those from WKY. We conclude that altered activity of the large conductance, calcium activated potassium channel may play a role in the increased responsiveness observed in arteries from SHRSP. PMID:8343237

  3. Spectrofluorimetric determination of cefixime using terbium-danofloxacin probe

    PubMed Central

    Manzoori, Jamshid L.; Amjadi, Mohammad; Soltani, Naser; Jouyban, Abolghasem

    2014-01-01

    Objective(s): Cefixime (Cfx), is a semi-synthetic third-generation oral cephalosporin antibiotic that is prescribed for the treatment of susceptible infections. There are some procedures for the determination of Cfx in pharmaceutical formulations and biological samples. Herein a spectrofluorimetric method was proposed for Cfx determination based on the fluorescence quenching of terbium-danofloxacin (Tb3+-Dano) in the presence of Cfx. Materials and Methods: Cfx was detected based on fluorescence quenching of terbium-danofloxacin (Tb3+-Dano) in the presence of Cfx with maximum excitation and emission wavelengths at 347 nm and 545 nm, respectively. The quenched fluorescence intensity of Tb3+- Dano system is proportional to the concentration of Cfx. The optimum conditions for the determination of Cfx were studied. Results: The maximum response was achieved under optimum conditions of [Tris buffer]= 0.008 mol/l (pH 6.5), [Tb3+]=1×10-4 mol/l and [Dano]=1×10-4 mol/l. The developed method was evaluated in terms of accuracy, precision and limit of detection. The linear concentration ranges for quantification of Cfx were 8.8×10-8-8.8×10-7 mol/l and 1.1×10-7-8.8×10-7 mol/l in standard and human serum samples with the detection limits (S/N=3) of 2.8×10-8 mol/l and 3.9×10-8 mol/l, respectively. The Cfx was determined in pharmaceutical tablets and spiked serum samples and the results were satisfactory. Conclusion: This method is simple, practical and relatively interference-free for determination of Cfx in pharmaceutical tablets and serum samples. PMID:24904718

  4. Corrigendum to "Excitation spectra of the d3Πg -c3 Σu+ band system of C2" [J. Mol. Spectrosc. 302 (2014) 9-16

    NASA Astrophysics Data System (ADS)

    Nakajima, Masakazu; Endo, Yasuki

    2014-11-01

    The authors regret that a transcription error was found in Table 1 of the original version of this paper. The spin-rotation constant 102γ determined in the present study for the v = 2 level, -1.0795(83), is incorrect. The value should be 1.5027(83).

  5. Studies into the Stability of 3-O-Glycosylated and 3,5-O-Diglycosylated Anthocyanins in Differently Purified Liquid and Dried Maqui (Aristotelia chilensis (Mol.) Stuntz) Preparations during Storage and Thermal Treatment.

    PubMed

    Brauch, Johanna E; Kroner, Mareike; Schweiggert, Ralf M; Carle, Reinhold

    2015-10-01

    Anthocyanin stabilities in diluted and differently purified maqui preparations were assessed during storage and thermal treatment at different pH values. By sequentially depleting the matrix, the influence of polar low-molecular-weight matrix constituents and non-anthocyanin phenolics was shown to be negligible. In contrast, pH substantially affected thermal stabilities of differently glycosylated cyanidin and delphinidin derivatives. At pH 3.6, half-lives of 3-O-glycosides were substantially shorter than those of respective 3,5-O-diglycosides. However, at pH 2.2, an inverse stability behavior was observed. Findings were corroborated using isolated pigments. Upon heating, cyanidin derivatives were more stable than their respective delphinidins, but their stability was similar during storage. Anthocyanins in liquid samples were more stable when stored at 4 °C as compared to 20 °C, whereas those in dried powders revealed maximum stability throughout storage. The study contains a detailed discussion and mechanistic hypothesis for the above-mentioned findings, providing insights relevant for food applications of maqui anthocyanins. PMID:26338479

  6. Corrigendum to "Temperature dependence of self- and N2-broadeningand pressure-induced shifts in the 3 ← 0 band of CO" [J. Mol. Struct. 695-696 (2004) 269-286

    NASA Astrophysics Data System (ADS)

    Predoi-Cross, A.; Hnatovsky, C.; Strong, K.; Drummond, J. R.; Chris Benner, D.

    2015-10-01

    The authors regret to inform that it has been brought to their attention that there may have been problems in the spectroscopic analysis published in this paper. Since we are unable to locate all the spectra and re-analyze them, we would like to kindly ask the readers not to read the content of section 3 and the sentences in Abstract, Introduction and Conclusions that refer to the spectroscopic analysis carried out in this study.

  7. Modélisation théorique des expériences de molécules uniques sur l'ADN et l'ARN : de l'élasticité au dégraffage des bases

    NASA Astrophysics Data System (ADS)

    Cocco, Simona; Marko, John F.; Monasson, Rémi

    We review statistical-mechanical theories of single-molecule micromanipulation experiments on nucleic acids. Firstly, models for describing polymer elasticity are introduced. We then review how these models are used to interpret single-molecule force-extension experiments on single-stranded and double-stranded DNA. Depending on the force and the molecules used, both smooth elastic behavior and abrupt structural transitions are observed. Thirdly, we show how combining the elasticity of two single nucleic acid strands with a description of the base-pairing interactions between them explains much of the phenomenology and kinetics of RNA and DNA 'unzipping' experiments. To cite this article: S. Cocco et al., C. R. Physique 3 (2002) 569-584.

  8. Comment on "Molecular Structure analysis and Spectroscopic Characterization of Carbimazole with experimental (FT-IR, FT-Raman and UV-Vis) techniques and quantum chemical calculations" [J. Mol. Struct. 1052 (2013) 38-49

    NASA Astrophysics Data System (ADS)

    Erben, Mauricio F.

    2014-01-01

    The title paper [1] reports the analysis of the vibrational spectra (infrared and Raman) of solid carbimazole based on the computed molecular structure for a rather unusual conformer. The optimized structure does agree neither with the reported crystallographic data nor with previous vibrational studies omitted in [1]. Here, after a careful analysis of the conformational space, the proper molecular structure of carbimazole has been calculated and the vibrational spectra have been analyzed. These results are in agreement with the available experimental data.

  9. Corrigendum to "Line shape parameters measurement and computations for self-broadened carbon dioxide transitions in the 30012 ← 00001 and 30013 ← 00001 bands, line mixing, and speed dependence" [J. Mol. Spectrosc. 245 (2007) 34-51

    NASA Astrophysics Data System (ADS)

    Predoi-Cross, A.; Unni, A. V.; Liu, W.; Schofield, I.; Holladay, C.; McKellar, A. R. W.; Hurtmans, D.

    2016-04-01

    The authors have been notified that there may be errors in the spectroscopic analysis presented in this published article. While the authors are re-analysing the spectra in a different approach, we would like to ask the readers to ignore the discussion of line parameters other than line positions. We would like to assure the readers that we are preparing follow-up manuscripts where we will compare our new results with those published earlier. These manuscripts will be submitted for publication in the same journal.

  10. Corrigendum to "The importance of suppressing spin diffusion effects in the accurate determination of the spatial structure of a flexible molecule by nuclear Overhauser effect spectroscopy" [J. Mol. Struct. 1106 (2016) 373-381

    NASA Astrophysics Data System (ADS)

    Khodov, I. A.; Efimov, S. V.; Kiselev, M. G.; Batista de Carvalho, L. A. E.; Klochkov, V. V.

    2016-06-01

    The original article to which this erratum refers was published in Journal of Molecular Structure, vol. 1106 (2016) [1]. In the original version of this article, Table 1 contained an error in column 10 (interatom distance averaging following the (r6)-algorithm, proton pairs H9-H5 and H7-H9). Analogous mistype was also present in Table 2 in Ref. [2] for distances H7-H9. Values present in Refs. [1,2] were far too small, but they were presented only for the sake of comparison of different averaging methods and did not influence the final conformer distribution. The Table 1 is reproduced below with the error corrected.

  11. RETRACTION of "Immune memory responses to HBV vaccine 13-18 years after primary vaccination" by L. Hou, W. Li, X. Wei, Y. Zhou, Y. Zhuo, H. Wu, B. Shen. Genet. Mol. Res. 14 (3): 8466-8472 (2015).

    PubMed

    Hou, L; Li, W; Wei, X; Zhou, Y; Zhuo, Y; Wu, H; Shen, B

    2016-01-01

    The article "Immune memory responses to HBV vaccine 13-18 years after primary vaccination" by L. Hou, W. Li, X. Wei, Y. Zhou, Y. Zhuo, H. Wu, B. Shen published in 2015 in Genetics and Molecular Research 14(3): 8466-8472 (http://dx.doi.org/10.4238/2015.July.28.14) has been found to be substantially equal to the article "Immune memory response induced in vitro by recombinant hepatitis B surface antigen challenge 13-18 years after primary vaccination" published in the Journal of Medical Virology 86:1700-1704 (2014) from Andrea do Livramento et al. (DOI: 10.1002/jmv.24012). The corresponding author of the article published in Genetics and Molecular Research, Baosheng Shen, alerted our editorial staff about this situation and requested the retraction of the article. The Publisher and Editor retract this article in Accordance with the recommendations of the Committee on Publication Ethics (COPE). After a thorough investigation, we have strong reasons to believe que the peer review process was failure and after review and contacting the authors, the editors of Genetics and Molecular Research have decided to retract the article. The authors and their institutions have been advised of this serious breach of ethics. PMID:26985925

  12. Corrigendum to "Synthesis and spectral characterization of new homologous 1,3,5-triaryl-2-pyrazolines: Influence of alkyloxy chain length on fluorescence" [Spectrochim. Acta Part A: Mol. Biomol. Spectrosc. 133 (2014) 182-189

    NASA Astrophysics Data System (ADS)

    Abbas, Asghar; Hussain, Safdar; Hafeez, Noureen; Naseer, Muhammad Moazzam

    2015-03-01

    The authors regret to inform that the affiliation of one of the authors, namely, Noureen Hafeez has been written as Department of Forensic Medicine & Toxicology, Rawalpindi Institute of Health Sciences (RIHS), Bahria University, Islamabad, Pakistan in the published article. The correct address is shown above.

  13. Phase structure and thermal evolution in coatings and powders obtained by sol-gel process: Part I. ZrO{sub 2}{endash}11.3 mol {percent} Y{sub 2}O{sub 3}

    SciTech Connect

    Rivas, P.C.; Caracoche, M.C.; Martinez, J.A.; Rodriguez, A.M.; Caruso, R.; Pellegri, N.; de Sanctis, O.

    1997-02-01

    Yttria-stabilized cubic zirconia powders and coatings produced by the sol-gel method have been investigated by Perturbed Angular Correlation Spectroscopy (PAC). Results indicate that the metastable cubic phase is retained during heating and cooling cycles. The hyperfine interaction that describes this cubic phase, once crystallized, exhibits two components in a constant ratio of 4:1. The components represent different vacancy configurations. For the fast movement of oxygen vacancies starting at 750{degree}C, which is reflected by the damping of the hyperfine pattern, an activation energy of 0.96 eV was determined. {copyright} {ital 1997 Materials Research Society.}

  14. Corrigendum to "Natural dye extract of lawsonia inermis seed as photo sensitizer for titanium dioxide based dye sensitized solar cells" [Spectrochim. Acta A Mol. Biomol. Spectrosc. 128 (2014) 420-426

    NASA Astrophysics Data System (ADS)

    Ananth, S.; Vivek, P.; Arumanayagam, T.; Murugakoothan, P.

    2015-05-01

    The authors regret to inform that the following text in page No. 425, "The conventionally prepared TiO2 based DSSC exhibits the observed values of Isc = 1.6 mA cm-2, Voc = 0.48 V and the calculated value of FF is 64.32%. Similarly, for pre dye treated TiO2 based DSSC, the observed values of Isc = 2.99 mA cm-2, Voc = 0.50 V and the calculated value of FF is 66.9%" should be read as, "The conventionally prepared TiO2 based DSSC exhibits the observed values of Isc = 2.99 mA cm-2, Voc = 0.50 V and the calculated value of FF is 66.9%. Similarly, for pre dye treated TiO2 based DSSC, the observed values of Isc = 4.2 mA cm-2, Voc = 0.56 V and the calculated value of FF is 62.5%". Though the text is typed wrongly, the I-V graph, the discussions and our conclusions are as same as that of our published article.

  15. Studies on enzymic browning of potatoes (Solanum tuberosum). III. Kinetics of potato phenoloxidase (EC 1.14.18.1 monophenol, dihydroxyphenylalanine: oxygen-oxidoreductase).

    PubMed

    Matheis, G; Belitz, H D

    1977-03-21

    From initial velocity studies a sequential mechanism for the reactions catalysed by phenoloxidase from potatoes is indicated. The data are in accordance with an ordered addition of oxygen and phenolic substrate to the enzyme, with oxygen being the first substrate bound at thermodynamic equilibrium. The Michaelis constants for L-tyrosine, L-dopa, and chlorogenic acid are 1.4 X 10(-3), 3.3 X 10(-4), and 1.4 X 10(-4) mol/l, respectively. The dissociation constant for the enzyme-oxygen complex is about 10(-3) mol/l. In the presence of chlorogenic acid no lag phase occurs in the course of L-tyrosine oxidation. With increasing amounts of chlorogenic acid the tyrosinase activity goes through a maximum. The significance of these findings for the in vivo action of the enzyme is discussed. PMID:404777

  16. Determination of kinetic parameters for biomass combustion.

    PubMed

    Álvarez, A; Pizarro, C; García, R; Bueno, J L; Lavín, A G

    2016-09-01

    The aim of this work is to provide a wide database of kinetic data for the most common biomass by thermogravimetric analysis (TGA) and differential thermogravimetry (DTG). Due to the characteristic parameters of DTG curves, a two-stage reaction model is proposed and the kinetic parameters obtained from model-based methods with energy activation values for first and second stages in the range 1.75·10(4)-1.55·10(5)J/mol and 1.62·10(4)-2.37·10(5)J/mol, respectively. However, it has been found that Flynn-Wall-Ozawa and Kissinger-Akahira-Sunose model-free methods are not suitable to determine the kinetic parameters of biomass combustion since the assumptions of these two methods were not accomplished in the full range of the combustion process. PMID:27233095

  17. Flow injection spectrophotometric determination of isoproterenol using an avocado (Persea americana) crude extract immobilized on controlled-pore silica reactor.

    PubMed

    Lupetti, Karina Omuro; Vieira, Iolanda Cruz; Fatibello-Filho, Orlando

    2002-04-22

    An enzymatic reactor was constructed by the immobilization of polyphenol oxidase (PPO) from avocado (Persea americana) crude extract in an inorganic support of controlled pore silica (CPS), after a previous step of silanization. This inorganic support has been used as an excellent carrier to immobilize this enzyme and the enzymatic reactor was used in a flow injection system for the determination of isoproterenol in pharmaceutical products. The procedure is based on the oxidation reaction of this drug with immobilized PPO and the product obtained was monitored at 492 nm. This system presented an analytical curve from 1.23x10(-4) to 7.38x10(-4) mol l(-1) isoproterenol with a detection limit of 6.25x10(-5) mol l(-1). Recoveries of isoproterenol between 98.5 and 103.1%, a relative standard deviation (R.S.D.) less than 1% (n=10) and 36 determinations per h were obtained. PMID:18968613

  18. A new synthesis of carbon encapsulated Fe5C2 nanoparticles for high-temperature Fischer-Tropsch synthesis.

    PubMed

    Hong, Seok Yong; Chun, Dong Hyun; Yang, Jung-Il; Jung, Heon; Lee, Ho-Tae; Hong, Sungjun; Jang, Sanha; Lim, Jung Tae; Kim, Chul Sung; Park, Ji Chan

    2015-10-28

    Using a simple thermal treatment under a CO flow, uniform micrometer-sized iron oxalate dihydrate cubes prepared by hydrothermal reaction were transformed into Fe5C2@C nanoparticles to form a mesoporous framework; the final structure was successfully applied to the high-temperature Fischer-Tropsch reaction and it showed high activity (CO conversion = 96%, FTY = 1.5 × 10(-4) molCO gFe(-1) s(-1)) and stability. PMID:26416550

  19. Pressure Dependence of the Acid/Base Equilibria of Methyl Orange in Aqueous Solutions to 1000 bars at 20°C

    SciTech Connect

    Suleimenov, Oleg M; Boily, Jean F

    2006-07-31

    The pressure dependence on the acid/base equilibria of methyl orange in aqueous solution was measured at 20°C in the 1-1000 bar range with a newly designed flow-through spectrophotometric cell. Combined chemometric and thermodynamic analyses of uv-vis spectrophotometric data were used to extract the dissociation constants as well as the changes in molar volume and isothermal compressibility of methyl orange as a function of pressure. The results show increasing pressure promotes the deprotonation of the methyl orange, with pK values ranging from 3.505 at 1 bar to 3.445 (0.002) at 1000 bars. Increasing pressure also yields small values of negative changes in the molar volume ranging from –6.9 cm3∙mol-1 at 1 bar to –1.7 cm3∙mol-1 at 1000 bars. The isothermal compressibility of methyl orange in this pressure range was estimated using the 2nd derivative of 2nd and 3rd order polynomial fits to the constants and gave rise to a constant value of –48.4x 10-4 cm3∙mol-1∙bar-1 in the former case, and increasing values from -107×10-4 cm3∙mol-1∙bar-1 at 1 bar to 3.43×10-4 cm3∙mol-1∙bar-1 at 1000 bars in the latter case. Molar absorption coefficients for the protonated and deprotonated species were also shown to be only slightly affected by pressure changes and can be used to accurately predict the absorption spectra of methyl orange as a function of pressure.

  20. New atmospheric composition observations in the Karakorum region: Influence of local emissions and large-scale circulation during a summer field campaign

    NASA Astrophysics Data System (ADS)

    Putero, D.; Cristofanelli, P.; Laj, P.; Marinoni, A.; Villani, P.; Broquet, A.; Alborghetti, M.; Bonafè, U.; Calzolari, F.; Duchi, R.; Landi, T. C.; Verza, G. P.; Vuillermoz, E.; Bonasoni, P.

    2014-11-01

    In this work we provide an overview of short lived climate forcers (SLCFs) and carbon dioxide variability in the Karakorum, by presenting results deriving from a field campaign carried out at Askole (3015 m a.s.l., Pakistan Northern Areas), by Baltoro glacier. By using an innovative embedded and transportable system, continuous measurements of aerosol particle number concentration (Np, 1571 ± 2670 cm-3), surface ozone (O3, 31.7 ± 10.4 nmol/mol), carbon dioxide (CO2, 394.3 ± 6.9 μmol/mol) and meteorological parameters have been performed from August 20th to November 10th 2012. The domestic combustion from the Askole village emerged as a possible systematic source of contamination in the valley, with short-lasting pollution events probably related to domestic cooking activities characterized by high values of Np (6066 ± 5903 cm-3). By excluding these local contamination events, mountain thermal wind regime dominated the diurnal variability of Np, O3 and CO2. In comparison to night-time, we observed higher Np (+354 cm-3) and O3 (+7 nmol/mol) but lower CO2 (-8 μmol/mol) in air-masses coming from the lower valley during the central part of the day. Part of the day-to-day atmospheric composition variability can be also ascribed to synoptic circulation variability, as observed by using HYSPLIT 5-day back-trajectories.