Corrosion product layers on magnesium alloys AZ31 and AZ61: Surface chemistry and protective ability

Science.gov (United States)

Feliu, S.; Llorente, I.

2015-08-01

This paper studies the chemical composition of the corrosion product layers formed on magnesium alloys AZ31 and AZ61 following immersion in 0.6 M NaCl, with a view to better understanding their protective action. Relative differences in the chemical nature of the layers were quantified by X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), energy dispersive analysis of X-ray (EDX) and low-angle X-ray diffraction (XRD). Corrosion behavior was investigated by Electrochemical Impedance Spectroscopy (EIS) and hydrogen evolution measurement. An inhibitive effect from the corrosion product layers was observed from EIS, principally in the case of AZ31, as confirmed by hydrogen evolution tests. A link was found between carbonate enrichment observed by XPS in the surface of the corrosion product layer, concomitant with the increase in the protective properties observed by EIS.

77 FR 10649 - Modification of Class E Airspace; Douglas, AZ

Science.gov (United States)

2012-02-23

...-1313; Airspace Docket No. 11-AWP-17] Modification of Class E Airspace; Douglas, AZ AGENCY: Federal... Bisbee Douglas International Airport, Douglas, AZ. Decommissioning of the Cochise VHF Omni-Directional... Federal Register a notice of proposed rulemaking to amend controlled airspace at Douglas, AZ (76 FR 78180...

DERECHOS CIVILES Y POLÍTICOS EN EL PERIODO REVOLUCIONARIO

Directory of Open Access Journals (Sweden)

Juan Manuel Valcárcel Torres

2008-01-01

Full Text Available La investigación que origina el presente artículo corresponde al esfuerzo emprendido por varias universidades Colombianas empeñadas en profundizar en algunos aspectos relacionados con la inminente celebración del bicentenario Constitucional Colombiano. Estas universidades son las de Medellín, Manizales, Libre y Militar Nueva Granada. Esta ha concentrado sus esfuerzos en la evolución de los derechos fundamentales a lo largo de la historia constitucional contenida en el periodo comprendido entre los años 1.810-2010. Parte del logro de este esfuerzo consiste precisamente en revisar la evolución de los derechos civiles y políticos, para la cual comenzaremos por el periodo revolucionario.

Tank 241-AZ-101 tank characterization plan

International Nuclear Information System (INIS)

Schreiber, R.D.

1995-01-01

The Defense Nuclear Facilities Safety Board has advised the DOE to concentrate the near-term sampling and analysis activities on identification and resolution of safety issues. The Data Quality Objective (DQO) process was chosen as a tool to be used in the resolution of safety issues. As a result, A revision in the Federal Facilities Agreement and Consent Order (Tri-Party Agreement) milestone M-44 has been made, which states that ''A Tank Characterization Plan (TCP) will also be developed for each double-shell tank (DST) and single-shell tank (SST) using the DQO process. Development of TCPs by the DQO process is intended to allow users to ensure their needs will be met and that resources are devoted to gaining only necessary information''. This document satisfies that requirement for Tank 241-AZ-101 (AZ-101) sampling activities. Tank AZ-101 is currently a non-Watch List tank, so the only DQOs applicable to this tank are the safety screening DQO and the compatibility DQO, as described below. The contents of Tank AZ-101, as of October 31, 1994, consisted of 3,630 kL (960 kgal) of dilute non-complexed waste and aging waste from PUREX (NCAW, neutralized current acid waste). Tank AZ-101 is expected to have two primary layers. The bottom layer is composed of 132 kL of sludge, and the top layer is composed of 3,500 kL of supernatant, with a total tank waste depth of approximately 8.87 meters

User Manual for the AZ-101 Data Acquisition System (AS-101 DAS)

Energy Technology Data Exchange (ETDEWEB)

BRAYTON, D.D.

2000-02-17

User manual for the TK AZ-101 Waste Retrieval System Data Acquisition System. The purpose of this document is to describe use of the AZ-101 Data Acquisition System (AZ-101 DAS). The AZ-101 DAS is provided to fulfill the requirements for data collection and monitoring as defined in Letters of Instruction (LOI) from Numatec Hanford Corporation (NHC) to Fluor Federal Services (FFS). For a complete description of the system, including design, please refer to the AZ-101 DAS System Description document, RPP-5572.

User Manual for the AZ-101 Data Acquisition System (AS-101 DAS)

International Nuclear Information System (INIS)

BRAYTON, D.D.

2000-01-01

User manual for the TK AZ-101 Waste Retrieval System Data Acquisition System. The purpose of this document is to describe use of the AZ-101 Data Acquisition System (AZ-101 DAS). The AZ-101 DAS is provided to fulfill the requirements for data collection and monitoring as defined in Letters of Instruction (LOI) from Numatec Hanford Corporation (NHC) to Fluor Federal Services (FFS). For a complete description of the system, including design, please refer to the AZ-101 DAS System Description document, RPP-5572

76 FR 78180 - Proposed Modification of Class E Airspace; Douglas, AZ

Science.gov (United States)

2011-12-16

...-1313; Airspace Docket No. 11-AWP-17] Proposed Modification of Class E Airspace; Douglas, AZ AGENCY... action proposes to modify Class E airspace at Bisbee Douglas International Airport, Douglas, AZ... feet above the surface at Douglas, AZ. Additional controlled airspace is necessary to accommodate...

Histone H2A.Z is essential for estrogen receptor signaling

Science.gov (United States)

Gévry, Nicolas; Hardy, Sara; Jacques, Pierre-Étienne; Laflamme, Liette; Svotelis, Amy; Robert, François; Gaudreau, Luc

2009-01-01

Incorporation of H2A.Z into the chromatin of inactive promoters has been shown to poise genes for their expression. Here we provide strong evidence that H2A.Z is incorporated into the promoter regions of estrogen receptor (ERα) target genes only upon gene induction, and that, in a cyclic pattern. Moreover, members of the human H2A.Z-depositing complex, p400, also follow the same gene recruitment kinetics as H2A.Z. Importantly, cellular depletion of H2A.Z or p400 leads to a severe defect in estrogen signaling, including loss of estrogen-specific cell proliferation. We find that incorporation of H2A.Z within TFF1 promoter chromatin allows nucleosomes to adopt preferential positions along the DNA translational axis. Finally, we provide evidence that H2A.Z is essential to allow estrogen-responsive enhancer function. Taken together, our results provide strong mechanistic insight into how H2A.Z regulates ERα-mediated gene expression and provide a novel link between H2A.Z–p400 and ERα-dependent gene regulation and enhancer function. PMID:19515975

Tank 241-AZ-102 tank characterization plan

International Nuclear Information System (INIS)

Schreiber, R.D.

1995-01-01

The Defense Nuclear Facilities Safety Board has advised the DOE to concentrate the near-term sampling and analysis activities on identification and resolution of safety issues. The Data Quality Objective (DQO) process was chosen as a tool to be used in the resolution of safety issues. As a result, a revision in the Federal Facilities Agreement and Consent Order (Tri-Party Agreement) milestone M-44 has been made, which states that ''A Tank Characterization Plan (TCP) will also be developed for each double-shell tank (DST) and single-shell tank (SST) using the DQO process ... Development of TCPs by the DQO process is intended to allow users to ensure their needs will be met and that resources are devoted to gaining only necessary information''. This document satisfies that requirement for tank 241-AZ-102 (AZ-102) sampling activities. Tank AZ-102 is currently a non-Watch List tank, so the only DQOs applicable to this tank are the safety screening DQO and the compatibility DQO, as described below. The current contents of Tank AZ-102, as of October 31, 1994, consisted of 3,600 kL (950 kgal) of dilute non-complexed waste and aging waste from PUREX (NCAW, neutralized current acid waste). Tank AZ-102 is expected to have two primary layers. The bottom layer is composed of 360 kL of sludge, and the top layer is composed of 3,240 kL of supernatant, with a total tank waste depth of approximately 8.9 meters

Influence of the Composition of the Hank’s Balanced Salt Solution on the Corrosion Behavior of AZ31 and AZ61 Magnesium Alloys

Directory of Open Access Journals (Sweden)

Jakub Tkacz

2017-11-01

Full Text Available The electrochemical corrosion characteristics of AZ31 and AZ61 magnesium alloys were analyzed in terms of potentiodynamic tests and electrochemical impedance spectroscopy. The influence of the solution composition and material surface finish was examined also through the analysis of corrosion products created on the samples’ surface after electrochemical measurements in terms of scanning electron microscopy using energy-dispersive spectroscopy. Obtained data revealed the differences in the response of the magnesium alloys to enriched Hank’s Balanced Salt Solution—HBSS+ (with Mg2+ and Ca2+ ions and Hank’s Balanced Salt Solution—HBSS (without Mg2+ and Ca2+ ions. Both examined alloys exhibited better corrosion resistance from the thermodynamic and kinetic point of view in the enriched HBSS+. AZ61 magnesium alloy reached higher values of polarization resistance than AZ31 magnesium alloy in both the used corrosion solutions. Phosphate-based corrosion products were characteristic for the AZ31 and AZ61 alloys tested in the HBSS (without Mg2+ and Ca2+ ions. The combination of phosphate-based corrosion products and clusters of MgO and Mg(OH2 was typical for the surface of samples tested in the enriched HBSS+ (with Mg2+ and Ca2+ ions. Pitting corrosion attack was observed only in the case of enriched HBSS+.

Electrochemical corrosion behavior of AZ91D alloy in ethylene glycol

International Nuclear Information System (INIS)

Fekry, A.M.; Fatayerji, M.Z.

2009-01-01

The effect of concentration on the corrosion behavior of Mg-based alloy AZ91D was investigated in ethylene glycol-water solutions using electrochemical techniques i.e. potentiodynamic polarization, electrochemical impedance measurements (EIS) and surface examination via scanning electron microscope (SEM) technique. This can provide a basis for developing new coolants for magnesium alloy engine blocks. Corrosion behavior of AZ91D alloy by coolant is important in the automotive industry. It was found that the corrosion rate of AZ91D alloy decreased with increasing concentration of ethylene glycol. For AZ91D alloy in chloride >0.05 M or fluoride 0.05 M for fluoride containing ethylene glycol solution, some inhibition effect has been observed. The corrosion of AZ91D alloy in the blank can be effectively inhibited by addition of 0.05 mM paracetamol that reacts with AZ91D alloy and forms a protective film on the surface at this concentration as confirmed by surface examination.

Corrosion product layers on magnesium alloys AZ31 and AZ61: Surface chemistry and protective ability

Energy Technology Data Exchange (ETDEWEB)

Feliu, S., E-mail: sfeliu@cenim.csic.es; Llorente, I.

2015-08-30

Highlights: • Surface chemistry of the corrosion product layers on magnesium alloys. • Influence of the type of alloy on the carbonate surface enrichment. • Relation between surface composition and protection properties. - Abstract: This paper studies the chemical composition of the corrosion product layers formed on magnesium alloys AZ31 and AZ61 following immersion in 0.6 M NaCl, with a view to better understanding their protective action. Relative differences in the chemical nature of the layers were quantified by X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), energy dispersive analysis of X-ray (EDX) and low-angle X-ray diffraction (XRD). Corrosion behavior was investigated by Electrochemical Impedance Spectroscopy (EIS) and hydrogen evolution measurement. An inhibitive effect from the corrosion product layers was observed from EIS, principally in the case of AZ31, as confirmed by hydrogen evolution tests. A link was found between carbonate enrichment observed by XPS in the surface of the corrosion product layer, concomitant with the increase in the protective properties observed by EIS.

Corrosion product layers on magnesium alloys AZ31 and AZ61: Surface chemistry and protective ability

International Nuclear Information System (INIS)

Feliu, S.; Llorente, I.

2015-01-01

Highlights: • Surface chemistry of the corrosion product layers on magnesium alloys. • Influence of the type of alloy on the carbonate surface enrichment. • Relation between surface composition and protection properties. - Abstract: This paper studies the chemical composition of the corrosion product layers formed on magnesium alloys AZ31 and AZ61 following immersion in 0.6 M NaCl, with a view to better understanding their protective action. Relative differences in the chemical nature of the layers were quantified by X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), energy dispersive analysis of X-ray (EDX) and low-angle X-ray diffraction (XRD). Corrosion behavior was investigated by Electrochemical Impedance Spectroscopy (EIS) and hydrogen evolution measurement. An inhibitive effect from the corrosion product layers was observed from EIS, principally in the case of AZ31, as confirmed by hydrogen evolution tests. A link was found between carbonate enrichment observed by XPS in the surface of the corrosion product layer, concomitant with the increase in the protective properties observed by EIS

Reorganization of Damaged Chromatin by the Exchange of Histone Variant H2A.Z-2

Energy Technology Data Exchange (ETDEWEB)

Nishibuchi, Ikuno [Department of Cellular Biology, Research Institute for Radiation Biology and Medicine, Hiroshima University, Hiroshima (Japan); Department of Radiation Oncology, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima (Japan); Department of Radiation Oncology, Hiroshima Prefectural Hospital, Hiroshima (Japan); Suzuki, Hidekazu; Kinomura, Aiko; Sun, Jiying; Liu, Ning-Ang [Department of Cellular Biology, Research Institute for Radiation Biology and Medicine, Hiroshima University, Hiroshima (Japan); Horikoshi, Yasunori [Department of Cellular Biology, Research Institute for Radiation Biology and Medicine, Hiroshima University, Hiroshima (Japan); Research Center for Mathematics of Chromatin Live Dynamics, Hiroshima University, Hiroshima (Japan); Shima, Hiroki [Department of Biochemistry, Graduate School of Medical Sciences, Tohoku University, Sendai (Japan); Kusakabe, Masayuki; Harata, Masahiko [Laboratory of Molecular Biology, Graduate School of Agricultural Science, Tohoku University, Sendai (Japan); Fukagawa, Tatsuo [Department of Molecular Genetics, National Institute of Genetics and The Graduate University for Advanced Studies, Mishima (Japan); Ikura, Tsuyoshi [Laboratory of Chromatin Regulatory Network, Department of Mutagenesis, Radiation Biology Center, Kyoto University, Kyoto (Japan); Ishida, Takafumi [Department of Cardiovascular Medicine, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima (Japan); Nagata, Yasushi [Department of Radiation Oncology, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima (Japan); Tashiro, Satoshi, E-mail: ktashiro@hiroshima-u.ac.jp [Department of Cellular Biology, Research Institute for Radiation Biology and Medicine, Hiroshima University, Hiroshima (Japan); Research Center for Mathematics of Chromatin Live Dynamics, Hiroshima University, Hiroshima (Japan)

2014-07-15

Purpose: The reorganization of damaged chromatin plays an important role in the regulation of the DNA damage response. A recent study revealed the presence of 2 vertebrate H2A.Z isoforms, H2A.Z-1 and H2A.Z-2. However, the roles of the vertebrate H2A.Z isoforms are still unclear. Thus, in this study we examined the roles of the vertebrate H2A.Z isoforms in chromatin reorganization after the induction of DNA double-strand breaks (DSBs). Methods and Materials: To examine the dynamics of H2A.Z isoforms at damaged sites, we constructed GM0637 cells stably expressing each of the green fluorescent protein (GFP)-labeled H2A.Z isoforms, and performed fluorescence recovery after photobleaching (FRAP) analysis and inverted FRAP analysis in combination with microirradiation. Immunofluorescence staining using an anti-RAD51 antibody was performed to study the kinetics of RAD51 foci formation after 2-Gy irradiation of wild-type (WT), H2A.Z-1- and H2A.Z-2-deficient DT40 cells. Colony-forming assays were also performed to compare the survival rates of WT, H2A.Z-1-, and H2A.Z-2-deficient DT40 cells with control, and H2A.Z-1- and H2A.Z-2-depleted U2OS cells after irradiation. Results: FRAP analysis revealed that H2A.Z-2 was incorporated into damaged chromatin just after the induction of DSBs, whereas H2A.Z-1 remained essentially unchanged. Inverted FRAP analysis showed that H2A.Z-2 was released from damaged chromatin. These findings indicated that H2A.Z-2 was exchanged at DSB sites immediately after the induction of DSBs. RAD51 focus formation after ionizing irradiation was disturbed in H2A.Z-2-deficient DT40 cells but not in H2A.Z-1-deficient cells. The survival rate of H2A.Z-2-deficient cells after irradiation was lower than those of WT and H2A.Z-1- DT40 cells. Similar to DT40 cells, H2A.Z-2-depleted U2OS cells were also radiation-sensitive compared to control and H2A.Z-1-depleted cells. Conclusions: We found that vertebrate H2A.Z-2 is involved in the regulation of the DNA

Reorganization of Damaged Chromatin by the Exchange of Histone Variant H2A.Z-2

International Nuclear Information System (INIS)

Nishibuchi, Ikuno; Suzuki, Hidekazu; Kinomura, Aiko; Sun, Jiying; Liu, Ning-Ang; Horikoshi, Yasunori; Shima, Hiroki; Kusakabe, Masayuki; Harata, Masahiko; Fukagawa, Tatsuo; Ikura, Tsuyoshi; Ishida, Takafumi; Nagata, Yasushi; Tashiro, Satoshi

2014-01-01

Purpose: The reorganization of damaged chromatin plays an important role in the regulation of the DNA damage response. A recent study revealed the presence of 2 vertebrate H2A.Z isoforms, H2A.Z-1 and H2A.Z-2. However, the roles of the vertebrate H2A.Z isoforms are still unclear. Thus, in this study we examined the roles of the vertebrate H2A.Z isoforms in chromatin reorganization after the induction of DNA double-strand breaks (DSBs). Methods and Materials: To examine the dynamics of H2A.Z isoforms at damaged sites, we constructed GM0637 cells stably expressing each of the green fluorescent protein (GFP)-labeled H2A.Z isoforms, and performed fluorescence recovery after photobleaching (FRAP) analysis and inverted FRAP analysis in combination with microirradiation. Immunofluorescence staining using an anti-RAD51 antibody was performed to study the kinetics of RAD51 foci formation after 2-Gy irradiation of wild-type (WT), H2A.Z-1- and H2A.Z-2-deficient DT40 cells. Colony-forming assays were also performed to compare the survival rates of WT, H2A.Z-1-, and H2A.Z-2-deficient DT40 cells with control, and H2A.Z-1- and H2A.Z-2-depleted U2OS cells after irradiation. Results: FRAP analysis revealed that H2A.Z-2 was incorporated into damaged chromatin just after the induction of DSBs, whereas H2A.Z-1 remained essentially unchanged. Inverted FRAP analysis showed that H2A.Z-2 was released from damaged chromatin. These findings indicated that H2A.Z-2 was exchanged at DSB sites immediately after the induction of DSBs. RAD51 focus formation after ionizing irradiation was disturbed in H2A.Z-2-deficient DT40 cells but not in H2A.Z-1-deficient cells. The survival rate of H2A.Z-2-deficient cells after irradiation was lower than those of WT and H2A.Z-1- DT40 cells. Similar to DT40 cells, H2A.Z-2-depleted U2OS cells were also radiation-sensitive compared to control and H2A.Z-1-depleted cells. Conclusions: We found that vertebrate H2A.Z-2 is involved in the regulation of the DNA

Enhancing Microstructure and Mechanical Properties of AZ31-MWCNT Nanocomposites through Mechanical Alloying

Directory of Open Access Journals (Sweden)

J. Jayakumar

2013-01-01

Full Text Available Multiwall carbon nanotubes (MWCNTs reinforced Mg alloy AZ31 nanocomposites were fabricated by mechanical alloying and powder metallurgy technique. The reinforcement material MWCNTs were blended in three weight fractions (0.33%, 0.66%, and 1% with the matrix material AZ31 (Al-3%, zinc-1% rest Mg and blended through mechanical alloying using a high energy planetary ball mill. Specimens of monolithic AZ31 and AZ31-MWCNT composites were fabricated through powder metallurgy technique. The microstructure, density, hardness, porosity, ductility, and tensile properties of monolithic AZ31 and AZ31-MWCNT nano composites were characterized and compared. The characterization reveals significant reduction in CNT (carbon nanoTube agglomeration and enhancement in microstructure and mechanical properties due to mechanical alloying through ball milling.

Electrochemical corrosion behavior of AZ91D alloy in ethylene glycol

Energy Technology Data Exchange (ETDEWEB)

Fekry, A.M. [Chemistry Department, Faculty of Science, Cairo University, Giza 12613 (Egypt)], E-mail: hham4@hotmail.com; Fatayerji, M.Z. [Chemistry Department, Faculty of Science, Cairo University, Giza 12613 (Egypt)

2009-11-01

The effect of concentration on the corrosion behavior of Mg-based alloy AZ91D was investigated in ethylene glycol-water solutions using electrochemical techniques i.e. potentiodynamic polarization, electrochemical impedance measurements (EIS) and surface examination via scanning electron microscope (SEM) technique. This can provide a basis for developing new coolants for magnesium alloy engine blocks. Corrosion behavior of AZ91D alloy by coolant is important in the automotive industry. It was found that the corrosion rate of AZ91D alloy decreased with increasing concentration of ethylene glycol. For AZ91D alloy in chloride >0.05 M or fluoride <0.05 M containing 30% ethylene glycol solution, they are more corrosive than the blank (30% ethylene glycol-70% water). However, at concentrations <0.05 for chloride or >0.05 M for fluoride containing ethylene glycol solution, some inhibition effect has been observed. The corrosion of AZ91D alloy in the blank can be effectively inhibited by addition of 0.05 mM paracetamol that reacts with AZ91D alloy and forms a protective film on the surface at this concentration as confirmed by surface examination.

Influence of MC3T3-E1 preosteoblast culture on the corrosion of a T6-treated AZ91 alloy

Science.gov (United States)

Brooks, Emily K.; Tobias, Menachem E.; Yang, Shuying; Bone, Lawrence B.; Ehrensberger, Mark T.

2015-01-01

This study investigated the corrosion of artificially aged T6 heat-treated Mg-9%Al-1%Zn (AZ91) for biomedical applications. Corrosion tests and surface analysis were completed both with and without a monolayer of mouse preosteoblast MC3T3-E1 cells cultured on the sample. Electrochemical impedance spectroscopy (EIS) and inductively coupled plasma mass spectroscopy (ICPMS) were used to explore the corrosion processes after either 3 or 21 days of AZ91 incubation in cell culture medium (CCM). The EIS showed both the inner layer resistance (Rin) and outer layer resistance (Rout) were lower for samples without cells cultured on the surface at 3 days (Rin = 2.64 e4 Ω/cm2, Rout = 140 Ω/cm2) compared to 21 days (Rin = 3.60 e4 Ω/cm2, Rout = 287 Ω/cm2) due to precipitation of magnesium and calcium phosphates over time. Samples with preosteoblasts cultured on the surface had a slower initial corrosion (3 day, Rin = 1.88 e5 Ω/cm2, Rout = 1060 Ω/cm2) which was observed to increase over time (21 day, Rin = 2.99 e4 Ω/cm2, Rout = 287 Ω/cm2). Changes in the corrosion processes were thought to be related to changes in the coverage provided by the cell layer. Our results reveal that the presence of cells and biological processes are able to significantly influence the corrosion rate of AZ91. PMID:25715925

ANALYSIS RESULTS FOR BUILDING 241 702-AZ A TRAIN

International Nuclear Information System (INIS)

DUNCAN JB; FRYE JM; COOKE CA; LI SW; BROCKMAN FJ

2006-01-01

This report presents the analyses results for three samples obtained under RPP-PLAN-28509, Sampling and Analysis Plan for Building 241 702-AZ A Train. The sampling and analysis was done in response to problem evaluation request number PER-2004-6139, 702-AZ Filter Rooms Need Radiological Cleanup Efforts

ANALYSIS RESULTS FOR BUILDING 241 702-AZ A TRAIN

Energy Technology Data Exchange (ETDEWEB)

DUNCAN JB; FRYE JM; COOKE CA; LI SW; BROCKMAN FJ

2006-12-13

This report presents the analyses results for three samples obtained under RPP-PLAN-28509, Sampling and Analysis Plan for Building 241 702-AZ A Train. The sampling and analysis was done in response to problem evaluation request number PER-2004-6139, 702-AZ Filter Rooms Need Radiological Cleanup Efforts.

Influence of artificial biological fluid composition on the biocorrosion of potential orthopedic Mg-Ca, AZ31, AZ91 alloys

International Nuclear Information System (INIS)

Gu, X N; Zheng, Y F; Chen, L J

2009-01-01

The electrochemical behavior of potential orthopedic Mg-Ca, AZ31 and AZ91 alloys was studied in Hank's solution, Dulbecco's Modified Eagle's Medium (DMEM) and serum-containing medium (DMEM adding 10% fetal bovine serum (DMEM+FBS)) over a 7 day immersion period. The biocorrosion of the above three alloys for various immersion time intervals was investigated by linear polarization and electrochemical impedance spectroscopy (EIS). After 7 day immersion, potentiodynamic polarization tests were carried out and the surface morphologies of experimental samples were examined by scanning electron microscopy (SEM) observation complemented by energy-disperse spectrometer (EDS) analysis. It was shown that the corrosion of magnesium alloys was influenced by the composition of the solution. The results indicated that chloride ion could reduce the corrosion resistance and the hydrocarbonate ions could induce rapid surface passivation. The adsorbed amino acid on the experimental magnesium alloys' surface increased their polarization resistance and reduced current densities. The influence of the serum protein on corrosion was found to be associated with the magnesium alloy compositions. A Mg-Ca alloy exhibited an increased corrosion rate in the presence of serum protein. An AZ31 alloy showed an increased corrosion rate in DMEM+FBS in the initial 3 day immersion and the corrosion rate decreased thereafter. An AZ91 alloy, with high Al content, showed a reduced corrosion rate with the addition of FBS into DMEM.

Influence of artificial biological fluid composition on the biocorrosion of potential orthopedic Mg-Ca, AZ31, AZ91 alloys.

Science.gov (United States)

Gu, X N; Zheng, Y F; Chen, L J

2009-12-01

The electrochemical behavior of potential orthopedic Mg-Ca, AZ31 and AZ91 alloys was studied in Hank's solution, Dulbecco's Modified Eagle's Medium (DMEM) and serum-containing medium (DMEM adding 10% fetal bovine serum (DMEM+FBS)) over a 7 day immersion period. The biocorrosion of the above three alloys for various immersion time intervals was investigated by linear polarization and electrochemical impedance spectroscopy (EIS). After 7 day immersion, potentiodynamic polarization tests were carried out and the surface morphologies of experimental samples were examined by scanning electron microscopy (SEM) observation complemented by energy-disperse spectrometer (EDS) analysis. It was shown that the corrosion of magnesium alloys was influenced by the composition of the solution. The results indicated that chloride ion could reduce the corrosion resistance and the hydrocarbonate ions could induce rapid surface passivation. The adsorbed amino acid on the experimental magnesium alloys' surface increased their polarization resistance and reduced current densities. The influence of the serum protein on corrosion was found to be associated with the magnesium alloy compositions. A Mg-Ca alloy exhibited an increased corrosion rate in the presence of serum protein. An AZ31 alloy showed an increased corrosion rate in DMEM+FBS in the initial 3 day immersion and the corrosion rate decreased thereafter. An AZ91 alloy, with high Al content, showed a reduced corrosion rate with the addition of FBS into DMEM.

Determinacion de periodos fundamentales del suelo mediante vibraciones ambientales en el municipio de Humacao, Puerto Rico

Science.gov (United States)

Cintron Aponte, Rommel

La tecnica de Nakamura ha sido utilizada a nivel mundial para determinar periodos fundamentales del suelo. La tecnica consiste en calcular y graficar cocientes espectrales H/V de vibraciones ambientales registradas sobre el suelo. Mediciones de vibraciones ambientales fueron tomadas en 151 lugares dentro del municipio de Humacao, localizado al este de Puerto Rico. Los datos se procesaron utilizando espectros de Fourier y espectros de potencia. La tecnica fue validada al compararla con los resultados de cocientes espectrales H/V de registros de sismos debiles y tambien con una modelacion numerica realizada con datos de un ensayo "downhole". Las graficas de los cocientes espectrales H/V fueron divididas en casos y grupos, los cuales dependen de la facilidad para identificar el periodo fundamental pico y amplitudes en frecuencias menores de 1 Hz, respectivamente. Los resultados obtenidos con ambos espectros fueron comparados y se concluye que los mismos se complementan para proveer resultados mas confiables. Se crearon mapas de periodos fundamentales, factores de amplitud, isoperiodos y clasificacion sismica de sitio. Los mapas de isoperiodos fueron realizados en las zonas mas pobladas sobre depositos de suelo. El mapa de periodos fundamentales del suelo mostro buena correlacion con la geologia local. El mapa de clasificacion sismica derivado de periodos de sitio fue comparado con el mapa de clasificacion sismica derivado de barrenos geotecnicos. El mapa de clasificacion obtenido de periodos puede sobreestimar un poco algunas clasificaciones del suelo. Sin embargo, este mapa puede proveer un estimado aproximado de la velocidad de onda de corte promedio del suelo hasta una profundidad de 100 pies (30 metros).

241-AZ Tank Farm Construction Extent of Condition Review for Tank Integrity

Energy Technology Data Exchange (ETDEWEB)

Barnes, Travis J.; Boomer, Kayle D.; Gunter, Jason R.; Venetz, Theodore J.

2013-07-30

This report provides the results of an extent of condition construction history review for tanks 241-AZ-101 and 241-AZ-102. The construction history of the 241-AZ tank farm has been reviewed to identify issues similar to those experienced during tank AY-102 construction. Those issues and others impacting integrity are discussed based on information found in available construction records, using tank AY-102 as the comparison benchmark. In the 241-AZ tank farm, the second DST farm constructed, both refractory quality and tank and liner fabrication were improved.

241-AY/AZ waste storage tanks: Supplemental gravity load analysis. Volume 1

International Nuclear Information System (INIS)

Baliga, R.

1994-01-01

An analysis of the 241SY tanks performed by ADVENT(1994b) to resolve dome overload issues indicated that the tank can sustain the dome loads resulting from additional soil overburden depth, increased soil density, and increased concentrated load. Similar issues exist for the 241AY/AZ tanks and therefore, an interim analysis of the 241AY/AZ tanks is presented herein. The scope of this effort is to review and compare all design drawings pertaining to the 241AY and 241AZ tanks with those pertaining to the 241SY tanks; to modify the axisymmetric model of the 241SY tanks to represent the 241AY/AZ tanks; and to evaluate the effect of additional dome load on the 241AY/AZ tanks by performing a structural analysis for gravity loads (dead load + live load). ADVENTS's additional scope of work is to perform a qualitative evaluation of the 241AY/AZ tanks for seismic and thermal loadings (Vollert 1982 and Blume 1971). This qualitative evaluation does not include any detailed finite element analysis of the tanks. The following design-based gravity loading conditions are used in this interim analysis of the 241AY/AZ tanks to determine a baseline for the tank stresses or section loads

Grain refinement of AZ31 magnesium alloy by electromagnetic ...

Indian Academy of Sciences (India)

Low-frequency electromagnetic field; AZ31 magnesium alloy; Al4C3; grain refinement. Abstract. The effects of electromagnetic stirring and Al4C3 grain refiner on the grain refinement of semicontinuously cast AZ31 magnesium alloy were discussed in this investigation. The results indicate that electromagnetic stirring has an ...

Caustic leaching of composite AZ-101/AZ-102 Hanford tank sludge

International Nuclear Information System (INIS)

Rapko, B.M.; Wagner, M.J.

1997-07-01

To reduce the quantity (and hence the cost) of glass canisters needed for disposing of high-level radioactive wastes from the Hanford tank farms, pretreatment processes are needed to remove as much nonradioactive material as possible. This report describes the results of a laboratory-scale caustic leaching test performed on a composite derived from a combination of 241-AZ-101 and 241-AZ-102 Hanford Tank sludges. The goals of this FY 1996 test were to evaluate the effectiveness of caustic leaching on removing key components from the sludge and to evaluate the effectiveness of varying the free-hydroxide concentrations by incrementally increasing the free hydroxide concentration of the leach steps up to 3 M free hydroxide. Particle-size analysis of the treated and untreated sludge indicated that the size and range of the sludge particles remained essentially unchanged by the caustic leaching treatment. Both before and after caustic leaching, a particle range of 0.2 microm to 50 microm was observed, with mean particle diameters of 8.5 to 9 microm based on the volume distribution and mean particle diameters of 0.3 to 0.4 microm based on the number distribution

CLIMATERIO Y POSTMENOPAUSIA: ASPECTOS EDUCATIVOS A CONSIDERAR SEGUN LA ETAPA DEL PERIODO

OpenAIRE

ARAYA GUTIERREZ,ALEJANDRA; URRUTIA SOTO,MARIA TERESA; CABIESES VALDES,BALTICA

2006-01-01

El periodo del climaterio es una etapa de transición en la vida de la mujer caracterizada por cambios físicos, psicológicos y sociales. Es una etapa dinámica marcada por la repercusión de los cambios hormonales, principalmente por la paulatina disminución de los estrógenos. La presente revisión bibliográfica describe las características generales del periodo, cambios que ocurren y aspectos a educar en las mujeres durante el climaterio y la postmenopausia, con el propósito de dar una visión ac...

Bioetanol de la caña de azúcar

Directory of Open Access Journals (Sweden)

N. Aguilar-Rivera

2007-01-01

Full Text Available La búsqueda de la viabilidad y desarrollo de la agroindustria de la caña de azúcar es ya una política imperativa. La producción de caña y azúcar constituyen la principal agroindustria del país, con presencia en 57 ingenios azucareros, localizados en 15 estados de la república. Sin embargo, la actual ineficiencia productiva, altos costos y otras causas —como la entrada de jarabe de maíz de alta fructosa (HFCS de menor costo— han desplazado el consumo interno de azúcar de caña, principalmente en bebidas embotelladas. Todos estos factores han contribuido a la actual y prolongada crisis del sector azucarero. Por lo tanto, la industria debe reestructurarse y reducir la producción de azúcar hacia la competitividad, con la alternativa del etanol combustible en la búsqueda de un futuro para la industria azucarera en México. Con la producción de etanol (EtOH a gran escala, por parte de los ingenios azucareros, es posible visualizar un nuevo y futuro mercado de uso de energías renovables en México, oportunidades para la exportación e incrementar los beneficios ambientales y económicos a través de su uso. La flexibilidad de la producción combinada, de azúcar y etanol en los ingenios, permitirá alcanzar esquemas y objetivos ambientales como nación. Para la industria azucarera, su mayor competidesafío, en este sentido, representa disminuir los costos actuales de producción de etanol a través del uso de la ingeniería genética, uso de diferentes materias primas y la totalidad de la planta de caña de azúcar e introducir mejoras tecnológicas.

Influence of artificial biological fluid composition on the biocorrosion of potential orthopedic Mg-Ca, AZ31, AZ91 alloys

Energy Technology Data Exchange (ETDEWEB)

Gu, X N; Zheng, Y F [State Key Laboratory for Turbulence and Complex System and Department of Advanced Materials and Nanotechnology, College of Engineering, Peking University, Beijing 100871 (China); Chen, L J, E-mail: yfzheng@pku.edu.c [School of Material Science and Engineering, Shengyang University of Technology, Shenyang 110023 (China)

2009-12-15

The electrochemical behavior of potential orthopedic Mg-Ca, AZ31 and AZ91 alloys was studied in Hank's solution, Dulbecco's Modified Eagle's Medium (DMEM) and serum-containing medium (DMEM adding 10% fetal bovine serum (DMEM+FBS)) over a 7 day immersion period. The biocorrosion of the above three alloys for various immersion time intervals was investigated by linear polarization and electrochemical impedance spectroscopy (EIS). After 7 day immersion, potentiodynamic polarization tests were carried out and the surface morphologies of experimental samples were examined by scanning electron microscopy (SEM) observation complemented by energy-disperse spectrometer (EDS) analysis. It was shown that the corrosion of magnesium alloys was influenced by the composition of the solution. The results indicated that chloride ion could reduce the corrosion resistance and the hydrocarbonate ions could induce rapid surface passivation. The adsorbed amino acid on the experimental magnesium alloys' surface increased their polarization resistance and reduced current densities. The influence of the serum protein on corrosion was found to be associated with the magnesium alloy compositions. A Mg-Ca alloy exhibited an increased corrosion rate in the presence of serum protein. An AZ31 alloy showed an increased corrosion rate in DMEM+FBS in the initial 3 day immersion and the corrosion rate decreased thereafter. An AZ91 alloy, with high Al content, showed a reduced corrosion rate with the addition of FBS into DMEM.

Influence of the Composition of the Hank’s Balanced Salt Solution on the Corrosion Behavior of AZ31 and AZ61 Magnesium Alloys

Czech Academy of Sciences Publication Activity Database

Tkacz, J.; Slouková, K.; Minda, J.; Drábiková, J.; Fintová, Stanislava; Doležal, P.; Wasserbauer, J.

2017-01-01

Roč. 7, č. 11 (2017), č. článku 465. ISSN 2075-4701 Institutional support: RVO:68081723 Keywords : magnesium alloy * AZ31 * AZ61 * HBSS * HBSS+ * EIS * potentiodynamic test Subject RIV: JK - Corrosion ; Surface Treatment of Materials OBOR OECD: Coating and films Impact factor: 1.984, year: 2016 http://www.mdpi.com/2075-4701/7/11/465

Microstructural Characteristics and Mechanical Properties of 2205/AZ31B Laminates Fabricated by Explosive Welding

Directory of Open Access Journals (Sweden)

Yan Li

2017-04-01

Full Text Available A bimetal composite of 2205 duplex stainless steel and AZ31B magnesium alloy was cladded successfully through the method of explosive welding. The microstructural characteristics and mechanical properties of 2205/AZ31B bimetal composite are discussed. The interface of 2205/AZ31B bimetallic composite was a less regular wavy morphology with locally melted pockets. Adiabatic shear bands occurred only in the AZ31B side near explosive welding interface. The microstructure observed with EBSD showed a strong refinement near the interface zones. Line scan confirmed that the interface had a short element diffusion zone which would contribute to the metallurgical bonding between 2205 duplex stainless steel and AZ31B magnesium alloy. The value of micro-hardness near the bonding interface of composite plate increased because of work hardening and grain refinement. The tensile shear strength of bonding interface of 2205/AZ31B composite was 105.63 MPa. Tensile strength of 2205/AZ31B composite material was higher than the base AZ31B. There were two abrupt drops in stress in the stress–strain curves of the 2205/AZ31B composite materials.

AZ91C magnesium alloy modified by Cd

DEFF Research Database (Denmark)

Shabadi, R.; Ambat, Rajan; Dwarakadasa, E.S.

2014-01-01

In the present work, the effect of Cd on the microstructure, mechanical properties and general corrosion behaviour of AZ91C alloys was investigated. Addition of Cd was found not to be efficient in modifying/refining the microstructure or β-phase. A morphology change in β-phase from fine continuous...... precipitates to discontinuous β-phase upon the addition of Cd was observed. A marginal increment in mechanical properties was observed. General corrosion behaviour was followed with weight loss measurements, potentiostatic polarisation studies and surface studies in 3.5% sodium chloride solution and 3.......5% sodium chloride with 2% potassium dichromate solution. Cd addition deteriorated the corrosion behaviour of AZ91C. This behaviour was attributed to the formation of chunks of β-phase upon the addition of Cd. AZ91C with refined β-phase distribution, performed rather better in the NaCl solutions....

Influence of MC3T3-E1 preosteoblast culture on the corrosion of a T6-treated AZ91 alloy.

Science.gov (United States)

Brooks, Emily K; Tobias, Menachem E; Yang, Shuying; Bone, Lawrence B; Ehrensberger, Mark T

2016-02-01

This study investigated the corrosion of artificially aged T6 heat-treated Mg-9%Al-1%Zn (AZ91) for biomedical applications. Corrosion tests and surface analysis were completed both with and without a monolayer of mouse preosteoblast MC3T3-E1 cells cultured on the sample. Electrochemical impedance spectroscopy (EIS) and inductively coupled plasma mass spectroscopy (ICPMS) were used to explore the corrosion processes after either 3 or 21 days of AZ91 incubation in cell culture medium (CCM). The EIS showed both the inner layer resistance (Rin ) and outer layer resistance (Rout ) were lower for samples without cells cultured on the surface at 3 days (Rin  = 2.64 e4 Ω/cm(2) , Rout  = 140 Ω/cm(2) ) compared to 21 days (Rin  = 3.60 e4 Ω/cm(2) , Rout  = 287 Ω/cm(2) ) due to precipitation of magnesium and calcium phosphates over time. Samples with preosteoblasts cultured on the surface had a slower initial corrosion (3 day, Rin  = 1.88 e5 Ω/cm(2) , Rout  = 1060 Ω/cm(2) ) which was observed to increase over time (21 day, Rin  = 2.99 e4 Ω/cm(2) , Rout  = 287 Ω/cm(2) ). Changes in the corrosion processes were thought to be related to changes in the coverage provided by the cell layer. Our results reveal that the presence of cells and biological processes are able to significantly influence the corrosion rate of AZ91. © 2015 Wiley Periodicals, Inc.

76 FR 18378 - Amendment of Class E Airspace; Taylor, AZ

Science.gov (United States)

2011-04-04

...-1189; Airspace Docket No. 10-AWP-19] Amendment of Class E Airspace; Taylor, AZ AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Final rule. SUMMARY: This action will amend Class E airspace at Taylor Airport, Taylor, AZ, to accommodate aircraft using the CAMBO One Departure, and the Area Navigation (RNAV...

System Description for Tank 241-AZ-101 Waste Retrieval Data Acquisition System

International Nuclear Information System (INIS)

ROMERO, S.G.

2000-01-01

The proposed activity provides the description of the Data Acquisition System for Tank 241-AZ-101. This description is documented in HNF-5572, Tank 241-AZ-101 Waste Retrieval Data Acquisition System (DAS). This activity supports the planned mixer pump tests for Tank 241-AZ-101. Tank 241-AZ-101 has been selected for the first full-scale demonstration of a mixer pump system. The tank currently holds over 960,000 gallons of neutralized current acid waste, including approximately 12.7 inches of settling solids (sludge) at the bottom of the tank. As described in Addendum 4 of the FSAR (LMHC 2000a), two 300 HP mixer pumps with associated measurement and monitoring equipment have been installed in Tank 241-AZ-101. The purpose of the Tank 241-AZ-101 retrieval system Data Acquisition System (DAS) is to provide monitoring and data acquisition of key parameters in order to confirm the effectiveness of the mixer pumps utilized for suspending solids in the tank. The suspension of solids in Tank 241-AZ-101 is necessary for pretreatment of the neutralized current acid waste and eventual disposal as glass via the Hanford Waste Vitrification Plant. HNF-5572 provides a basic description of the Tank 241-AZ-101 retrieval system DAS, including the field instrumentation and application software. The DAS is provided to fulfill requirements for data collection and monitoring. This document is not an operations procedure or is it intended to describe the mixing operation. This USQ screening provides evaluation of HNF-5572 (Revision 1) including the changes as documented on ECN 654001. The changes include (1) add information on historical trending and data backup, (2) modify DAS I/O list in Appendix E to reflect actual conditions in the field, and (3) delete IP address in Appendix F per Lockheed Martin Services, Inc. request

Effect of mechanical vibrations on the wear behavior of AZ91 Mg alloy

Science.gov (United States)

Chaturvedi, V.; Pandel, U.; Sharma, A.

2018-02-01

AZ91 Mg alloy is the most promising alloy used for structural applications. The vibration induced methods are effective and economic viable in term of mechanical properties. Sliding wear tests were performed on AZ91 Mg alloy using a pin-on- disc configuration. Wear rates were measured at 5 N and 10N at a sliding velocity of 1m/s for varied frequency within the range of 5- 25Hz and a constant amplitude of 2mm. Microstructures of worn surfaces and wear debris were characterized by field emission scanning electron microscopy (FESEM). It is observed that wear resistance of vibrated AZ91 alloy at 15Hz frequency ad 2mm amplitude was superior than cast AZ91 Mg alloy. Finer grain size and equiaxed grain shape both are important parameters for better wear resistance in vibrated AZ91 Mg alloys. FESEM analysis revealed that wear is considerably affected due to frictional heat generated by the relative motion between AZ91 Mg alloy and EN31 steel surface. No single mechanism was responsible for material loss.

Corrosion behaviour and in vitro/in vivo biocompatibility of surface-modified AZ31 alloy; Comportamiento frente a la corrosion y biocompatibilidad in vitrolin vivo de la aleacion AZ31 modificada superficialmente

Energy Technology Data Exchange (ETDEWEB)

Carboneras, M.; Iglesias, C.; Perez-Maceda, B. T.; Valle, J. A. de; Garcia-Alonso, M. C.; Alobera, M. A.; Clemente, C.; Rubio, J. C.; Escudero, M. I.; Lozano, R. M.

2011-07-01

The present work evaluates the corrosion behaviour and the in vitro/in vivo biocompatibility of the AZ31 magnesium alloy, which fulfills the mechanical requirements of bone. The corrosion kinetic of as-received AZ31 alloy was not compatible with the cell growth. To improve its performance, the AZ31 alloy was surface modified by a chemical conversion treatment in hydrofluoric acid. The magnesium fluoride layer generated by the surface treatment of AZ31 alloy enhances its corrosion behaviour, allowing the in vitro growth of osteoblastic cells over the surface and the in vivo formation of a highly compact layer of new bone tissue. These results lead to consider the magnesium fluoride coating as necessary for potential use of the AZ31 alloy as biodegradable and absorbable implant for bone repair. (Author) 18 refs.

Influence of cerium on passivity behavior of wrought AZ91 alloy

International Nuclear Information System (INIS)

Wang Henan; Li Ying; Wang Fuhui

2008-01-01

In this paper, more focus had been put on the passivity behavior of wrought AZ91 alloy with 1.5 mass% Ce. The passive current density of wrought AZ91 alloy increased with addition of Ce and the passive film became unstable. Structures and compositions of the passive films formed on wrought AZ91 alloy without and with Ce in 0.01 M NaOH aqueous solution were analyzed by potentiostatic polarization, potentiostatic-galvanostatic (P-G) transient technique and X-ray photoelectron spectroscopy (XPS). The results showed that Ce only accumulated in the inner layer of passive film in the form of CeO 2 . Further analysis revealed that there were two main effects of Ce on the passive process of wrought AZ91 alloy: first, the existence of CeO 2 in inner layer of passive film made mass transport through the passive film follow tangent hyperbolic (T) impedance instead of Warburg impedance (W); second, donor concentration (N d ) of the passive film increased by a factor 10 when 1.5 mass% Ce existed in wrought AZ91 alloy, which led to the higher passivity current density

Effect of aluminum coatings on corrosion properties of AZ31 magnesium alloy

Energy Technology Data Exchange (ETDEWEB)

Chiu Liuho; Lin Hsingan; Chen Chunchin; Yang Chihfu [Dept. of materials engineering, Tatung Univ., Taipei (Taiwan); Chang Chiahua; Wu Jenchin [Physical chemistry section, chemical systems research div., Chung-Shan Inst. of Science and Technology, Tao-Yuan (Taiwan)

2003-07-01

This investigation aimed to increase the corrosion resistance of an AZ31 magnesium alloy by an aluminum arc spray coating and a post-treatment consisted of hot pressing and anodizing. It was found that the aluminum arc spraying alone was incapable of protection against corrosion due to the high amount of pores present in the coating layer. In order to solve the problem, densification of the Al arc-sprayed layer was carried out by hot pressing the coated AZ31 Mg alloy plate under an appropriate range of temperature, time and pressure. After hot pressing the Al coated AZ31 Mg alloy plate exhibited a much improved corrosion resistance. A final anodizing treatment applied to the AZ31 alloy with the dense Al coating further improved its resisting to corrosion. The results showed that, by adopting the Al arc spraying, hot pressing and anodizing process, the corrosion current density of the AZ31 alloy in a 3.5 wt% NaCl solution was from 2.1 x 10{sup -6} A/cm{sup 2} (original AZ31) to 3.7 x 10{sup -7} A/cm{sup 2} (after the surface treatment), which value is close to that of an anodized aluminum plate. (orig.)

Microstructure and Aging Behavior of Nonflammable AZ91D Mg Alloy

OpenAIRE

Seok Hong Min; Tae Kwon Ha

2014-01-01

Phase equilibria of AZ91D Mg alloys for nonflammable use, containing Ca and Y, were carried out by using FactSage® and FTLite database, which revealed that solid solution treatment could be performed at temperatures from 400 to 450oC. Solid solution treatment of AZ91D Mg alloy without Ca and Y was successfully conducted at 420oC and supersaturated microstructure with all beta phase resolved into matrix was obtained. In the case of AZ91D Mg alloy with some Ca and Y; howeve...

Corrosion properties and corrosion evolution of as-cast AZ91 alloy with rare earth yttrium

International Nuclear Information System (INIS)

Luo, T.J.; Yang, Y.S.

2011-01-01

Highlights: → Minor addition of Y will increase the corrosion resistance of AZ91 alloy, and 0.3 wt.% Y is the optimum addition. → A film composed of Mg(OH) 2 , MgCO 3 , Al(OH) 3 and Al 2 O 3 is formed on the surface of AZ91 alloy with rare earth Y free. → The film of AZ91 alloy with 0.3 wt.% Y is mainly composed of Mg(OH) 2 and MgCO 3 without any Al(OH) 3 and Al 2 O 3 . → The relative quantity of MgCO 3 in the surface film of AZ91 + 0.3 wt.% Y is bigger than that of AZ91 alloy with Y free. → Y 2 O 3 phase is found in the surface film of alloy III, which benefits to stabilize the surface film. -- Abstract: The corrosion resistance property and the corrosion evolution of as-cast AZ91 alloy with rare earth Y addition are investigated by using immersion tests, electrochemical impedance spectroscopy (EIS), and X-ray photoelectron spectroscopy (XPS). The results show that the proper amount of Y in the alloys can improve the corrosion resistance of AZ91 alloys effectively. With the increment of Y, the corrosion rate of the modified AZ91 alloys by Y addition was markedly less than that of AZ91 alloy. The corrosion rate of AZ91 alloy with 0.3 wt.% Y was the slightest, but further addition of Y content over 0.3 wt.% make the corrosion heavier. The XPS analysis suggests that the compound film of AZ91 alloy with 0.3 wt.% Y is mainly composed of Mg(OH) 2 and MgCO 3 without any Al(OH) 3 and Al 2 O 3 , in addition, Y 2 O 3 phase is found in the compound film of AZ91 alloy with 0.3 wt.% Y, which benefits to stabilize the surface film.

702AZ aging waste ventilation facility year 2000 test procedure

International Nuclear Information System (INIS)

Winkelman, W.D.

1998-01-01

This test procedure was developed to determine if the 702AZ Tank Ventilation Facility system is Year 2000 Compliant. The procedure provides detailed instructions for performing the operations necessary and documenting the results. This verification procedure will document that the 702AZ Facility Systems are year 2000 compliant and will correctly meet the criteria established in this procedure

Effect of the chemistry and structure of the native oxide surface film on the corrosion properties of commercial AZ31 and AZ61 alloys

Energy Technology Data Exchange (ETDEWEB)

Feliu, Sebastian, E-mail: sfeliu@cenim.csic.es [Centro Nacional de Investigaciones Metalurgicas CSIC, Avda. Gregorio del Amo 8, 28040 Madrid (Spain); Maffiotte, C. [CIEMAT-DT edificio 30, Avda. Complutense, 22, 28040 Madrid (Spain); Samaniego, A.; Galvan, Juan Carlos [Centro Nacional de Investigaciones Metalurgicas CSIC, Avda. Gregorio del Amo 8, 28040 Madrid (Spain); Barranco, Violeta [Centro Nacional de Investigaciones Metalurgicas CSIC, Avda. Gregorio del Amo 8, 28040 Madrid (Spain); Instituto de Ciencias de Materiales de Madrid, ICMM, Consejo Superior de Investigaciones Cientificas, CSIC, Sor Juana Ines de la Cruz, 3, Cantoblanco, 28049, Madrid (Spain)

2011-08-01

The purpose of this study has been to advance in knowledge of the chemical composition, structure and thickness of the thin native oxide film formed spontaneously in contact with the laboratory atmosphere on the surface of freshly polished commercial AZ31 and AZ61 alloys with a view to furthering the understanding of protection mechanisms. For comparative purposes, and to more fully describe the behaviour of the native oxide film, the external oxide films formed as a result of the manufacturing process (as-received condition) have been characterised. The technique applied in this research to study the thin oxide films (thickness of just a few nanometres) present on the surface of the alloys has basically been XPS (X-ray photoelectron spectroscopy) in combination with ion sputtering. Corrosion properties of the alloys were studied in 0.6 M NaCl by measuring charge transfer resistance values, which are deduced from EIS (electrochemical impedance spectroscopy) measurements after 1 h of exposure. Alloy AZ61 generally showed better corrosion resistance than AZ31, and the freshly polished alloys showed better corrosion resistance than the alloys in as-received condition. This is attributed to a combination of (1) higher thickness of the native oxide film on the AZ61 alloy and (2) greater uniformity of the oxide film in the polished condition. The formation of an additional oxide layer composed by a mixture of spinel (MgAl{sub 2}O{sub 4}) and MgO seems to diminish the protective properties of the passive layer on the surface of the alloys in as-received condition.

Effect of the chemistry and structure of the native oxide surface film on the corrosion properties of commercial AZ31 and AZ61 alloys

International Nuclear Information System (INIS)

Feliu, Sebastian; Maffiotte, C.; Samaniego, A.; Galvan, Juan Carlos; Barranco, Violeta

2011-01-01

The purpose of this study has been to advance in knowledge of the chemical composition, structure and thickness of the thin native oxide film formed spontaneously in contact with the laboratory atmosphere on the surface of freshly polished commercial AZ31 and AZ61 alloys with a view to furthering the understanding of protection mechanisms. For comparative purposes, and to more fully describe the behaviour of the native oxide film, the external oxide films formed as a result of the manufacturing process (as-received condition) have been characterised. The technique applied in this research to study the thin oxide films (thickness of just a few nanometres) present on the surface of the alloys has basically been XPS (X-ray photoelectron spectroscopy) in combination with ion sputtering. Corrosion properties of the alloys were studied in 0.6 M NaCl by measuring charge transfer resistance values, which are deduced from EIS (electrochemical impedance spectroscopy) measurements after 1 h of exposure. Alloy AZ61 generally showed better corrosion resistance than AZ31, and the freshly polished alloys showed better corrosion resistance than the alloys in as-received condition. This is attributed to a combination of (1) higher thickness of the native oxide film on the AZ61 alloy and (2) greater uniformity of the oxide film in the polished condition. The formation of an additional oxide layer composed by a mixture of spinel (MgAl 2 O 4 ) and MgO seems to diminish the protective properties of the passive layer on the surface of the alloys in as-received condition.

76 FR 30299 - Proposed Establishment of Class E Airspace; Kayenta, AZ

Science.gov (United States)

2011-05-25

...-0393; Airspace Docket No. 11-AWP-2] Proposed Establishment of Class E Airspace; Kayenta, AZ AGENCY... action proposes to establish Class E Airspace at Kayenta Airport, Kayenta, AZ. Controlled airspace is...) standard instrument approach procedures at Kayenta Airport. The FAA is proposing this action to enhance the...

EnviroAtlas - Phoenix, AZ - Block Groups

Data.gov (United States)

U.S. Environmental Protection Agency — This EnviroAtlas dataset is the base layer for the Phoenix, AZ EnviroAtlas area. The block groups are from the US Census Bureau and are included/excluded based on...

Korozní odolnost tvářených hořčíkových slitin AZ31 a AZ61 v Hankovì roztoku

Czech Academy of Sciences Publication Activity Database

Tkacz, J.; Slouková, K.; Minda, J.; Drábiková, J.; Fintová, Stanislava; Doležal, P.; Wasserbauer, J.

2016-01-01

Roč. 60, č. 4 (2016), s. 101-106 ISSN 1804-1213 Institutional support: RVO:68081723 Keywords : corrosion * AZ31 magnesium alloy * AZ61 magnesium alloy Subject RIV: JK - Corrosion ; Surface Treatment of Materials https://www.degruyter.com/view/j/kom.2016.60.issue-4/kom-2016-0016/kom-2016-0016.xml?format=INT

Differential deposition of H2A.Z in rice seedling tissue during the day-night cycle.

Science.gov (United States)

Zhang, Kang; Xu, Wenying; Wang, Chunchao; Yi, Xin; Su, Zhen

2017-03-04

Chromatin structure has an important role in modulating gene expression. The incorporation of histone variants into the nucleosome leads to important changes in the chromatin structure. The histone variant H2A.Z is highly conserved between different species of fungi, animals, and plants. However, dynamic changes to H2A.Z in rice have not been reported during the day-night cycle. In this study, we generated genome wide maps of H2A.Z for day and night time in harvested seedling tissues by combining chromatin immunoprecipitation and high-throughput sequencing. The analysis results for the H2A.Z data sets detected 7099 genes with higher depositions of H2A.Z in seedling tissues harvested at night compared with seedling tissues harvested during the day, whereas 4597 genes had higher H2A.Z depositions in seedlings harvested during the day. The gene expression profiles data suggested that H2A.Z probably negatively regulated gene expression during the day-night cycle and was involved in many important biologic processes. In general, our results indicated that H2A.Z may play an important role in plant responses to the diurnal oscillation process.

A study on the relationships between corrosion properties and chemistry of thermally oxidised surface films formed on polished commercial magnesium alloys AZ31 and AZ61

Science.gov (United States)

Feliu, Sebastián; Samaniego, Alejandro; Barranco, Violeta; El-Hadad, A. A.; Llorente, Irene; Serra, Carmen; Galván, J. C.

2014-03-01

This paper studies the changes in chemical composition of the thin oxide surface films induced by heating in air at 200 °C for time intervals from 5 min to 60 min on the freshly polished commercial AZ31 and AZ61 alloys with a view to better understanding their protective properties. This thermal treatment resulted in the formation of layers enriched in metallic aluminium at the interface between the outer MgO surface films and the bulk material. A strong link was found between the degree of metallic Al enrichment in the subsurface layer (from 10 to 15 at.%) observed by XPS (X-ray photoelectron spectroscopy) in the AZ61 treated samples and the increase in protective properties observed by EIS (electrochemical impedance spectroscopy) in the immersion test in 0.6 M NaCl. Heating for 5-60 min in air at 200 °C seems to be an effective, easy to perform and inexpensive method for increasing the corrosion resistance of the AZ61 alloy by approximately two or three times.

The A-Z of electronuclear power

International Nuclear Information System (INIS)

Temmerman, G. de; Chedorge, D.

1992-01-01

Both a bilingual translation aid and a reference book, 'The A-Z of Electronuclear Power' covers the full range of electronuclear activities and the English and French terminology relating to the different phases of the modern industrial process

76 FR 3570 - Proposed Amendment of Class E Airspace; Taylor, AZ

Science.gov (United States)

2011-01-20

...-1189; Airspace Docket No. 10-AWP-19] Proposed Amendment of Class E Airspace; Taylor, AZ AGENCY: Federal... proposes to modify Class E airspace at Taylor Airport, Taylor, AZ. Controlled airspace is necessary to accommodate aircraft using the CAMBO One Departure Area Navigation (RNAV) out of Taylor Airport. The FAA is...

Electrochemical polymerization of pyrrole over AZ31 Mg alloy for biomedical applications

International Nuclear Information System (INIS)

Srinivasan, A.; Ranjani, P.; Rajendran, N.

2013-01-01

Highlights: ► Polymerization of pyrrole over AZ31 Mg was carried out using cyclic voltammetry. ► Pyrrole concentration was optimized to accomplish the adherent and uniform coating. ► Effect of monomer concentration on the surface morphology was discussed. ► Corrosion resistance of AZ31 Mg in SBF was studied as a function of Py concentration. ► PPy coated AZ31 Mg alloy exhibited enhanced corrosion resistance at 0.25 M of Py. -- Abstract: Electrochemical polymerization of pyrrole (Py) from aqueous salicylate solution over AZ31 Mg alloy was carried out using cyclic voltammetry (CV). The effect of monomer concentration on the surface and electrochemical corrosion in simulated body fluid (SBF) were analysed. Attenuated total reflection-infrared (ATR-IR) spectra showed the characteristic ring stretching peaks for polypyrrole (PPy). Scanning electron microscopy (SEM) and atomic force microscopy (AFM) studies exhibited typical cauliflower morphology with rough surface for PPy coated AZ31 Mg alloy. Open circuit potential measurement and potentiodynamic polarization studies revealed that the coating prepared using 0.25 M of Py had positive shift of about 120 mV in corrosion potential and lower corrosion current density (0.03 mA/cm 2 ) compared to other concentrations and uncoated AZ31 Mg alloy (0.25 mA/cm 2 ). Electrochemical impedance spectroscopic (EIS) studies of uncoated and PPy coated Mg alloy in SBF revealed three-time constants behaviour with about one order of increment in impedance value for 0.25 M of Py

Friction welding of AZ31 magnesium alloy

Energy Technology Data Exchange (ETDEWEB)

Tsujino, R.; Ochi, H. [Osaka Inst. of Tech., Osaka (Japan); Kawai, G. [Osaka Sangyo Univ., Osaka (Japan); Yamaguchi, H.; Ogawa, K. [Osaka Prefecture Univ., Osaka (Japan); Suga, Y. [Keio Univ., Kanagawa (Japan)

2003-07-01

In this paper, for an acceleration of utilization of magnesium alloy which is being interested in recent years, friction welding of AZ31 magnesium alloy was carried out, and the joint performance was discussed in relation to the deformation heat input in the upset stage and upset loss as a evaluation factor. Where, the deformation heat input in the upset stage is mechanical work represented by the product of upset speed and axial pressure. As a result, it was made clear that the friction welding of AZ31 magnesium alloy was easy in the atmosphere, and good welded joints without a non- adhesion area at the weld interface could de obtained. Moreover, the evaluation factors discussed were possible to evaluate to joint performance. (orig.)

AZ-101 Mixer Pump Test Qualification Test Procedures (QTP)

International Nuclear Information System (INIS)

THOMAS, W.K.

2000-01-01

Describes the Qualification test procedure for the AZ-101 Mixer Pump Data Acquisition System (DAS). The purpose of this Qualification Test Procedure (QTP) is to confirm that the AZ-101 Mixer Pump System has been properly programmed and hardware configured correctly. This QTP will test the software setpoints for the alarms and also check the wiring configuration from the SIMcart to the HMI. An Acceptance Test Procedure (ATP), similar to this QTP will be performed to test field devices and connections from the field

In Vitro Studies on the Degradability, Bioactivity, and Cell Differentiation of PRP/AZ31B Mg Alloys Composite Scaffold

Directory of Open Access Journals (Sweden)

Jian Zou

2017-01-01

Full Text Available In recent years, more and more methods have been developed to improve the bioactivity of the biodegradable materials in bone tissue regeneration. In present study, we used rat mesenchymal stem cells (rMSCs to evaluate the outcomes of Mg alloys (AZ31B, Magnesium, and Aluminum and Platelet-rich plasma (PRP/Mg alloys on rMSCs biocompatibility and osteogenic differentiation. Water absorption experiments indicated that both bare AZ31B and PRP/AZ31B were capable of absorbing large amounts of water. But the water absorption ratio for PRP/AZ31B was significantly higher than that for bare AZ31B. The degradability experiments implied that both samples degraded at same speed. rMSCs on the surface of AZ31B distributed more and better than those on the AZ31B scaffold. In ALP activity experiment, the activity of rMSCs on the PRP/AZ31B was markedly higher than that on the AZ31B scaffolds on the 7th day and 14th day. qRT-PCR also showed that OPN and OCN were expressed in both samples. OPN and OCN expression in PRP/AZ31B sample were higher than those in bare AZ31B samples. In summary, the in vitro study implied that AZ31B combined with PRP could remarkably improve cell seeding, attachment, proliferation, and differentiation.

Selectividad de caña de azúcar en bovinos

Directory of Open Access Journals (Sweden)

E. M. Aranda

2009-01-01

Full Text Available Se condujo este trabajo con el objetivo de conocer la aceptación del forraje de caña de azúcar integral en la dieta con base de pasto para bovinos adultos fistulados en rumen y duodeno estabulados; para ello, se ofreció pasto estrella africana (Cynodon plectostachyus y caña de azúcar (Saccharum officinarum mezclada con 1% de urea a voluntad, por separado. Se midió la composición de los alimentos, consumo de materia seca, pH ruminal y duodenal. Se utilizaron técnicas de la estadística descriptiva, como la media aritmética y error estándar. La proteína, paredes celulares y hemicelulosa fueron mayores para el pasto estrella. El consumo de MS fue de 46.6 y 38.1% para la caña de azúcar y el pasto, respectivamente; el pH ruminal tuvo valores de 7.3, disminuyendo a 6.7 a las 12 h.; y el pH de la digesta duodenal osciló de 3.7 a 4.7. Se concluye que hubo mayor aceptación por la caña de azúcar y el pH ruminal no indica valores que afecten la celulólisis ruminal.

Comportamiento mecánico de la aleación AZ31 reforzada con nanofibras de carbono

Directory of Open Access Journals (Sweden)

Adeva, P.

2010-12-01

Full Text Available The aim of this study is to investigate the effect of reinforcing AZ31 with carbon nanofibres. The materials AZ31, AZ31-1 % C y AZ31-2 % C were produced by a conventional powder metallurgy route consisting of mechanical mixing of nanofibres and powders of AZ31, cool compactation and extrusion at 350 °C. After extrusion the three materials exhibited a recrystallized microstructure of similar grain size, fine and rather inhomogeneous. Furthermore, they presented a weak fibre texture with basal plane parallel to the extrusion direction. The tensile properties were affected by the nanofibres presence only at 100 °C. At this temperature, yield strength and tensile strength were 30% higher than in the unreinforced alloy.

En este trabajo se ha estudiado el efecto de la adición de nanofibras de carbono en las propiedades mecánicas de la aleación AZ31 procesada por una ruta pulvimetalúrgica convencional. Se prepararon tres materiales, AZ31, AZ31- 1 % C y AZ31-2 % C. Tras una mezcla mecánica de las nanofibras con los polvos de AZ31, se precompactaron en frío y se extruyeron a 350 °C. Los tres presentan una microestructura recristalizada con un tamaño de grano similar, fino aunque algo heterogéneo. Los tres materiales presentan una débil textura de fibra con el plano basal paralelo a la dirección de extrusión. Las propiedades mecánicas a tracción únicamente se ven afectadas por la presencia de nanofibras a 100 °C superando los materiales reforzados en un 30 % a los valores de límite elástico y resistencia de la aleación sin reforzar.

Microstructure and corrosion resistance of Ce–V conversion coating on AZ31 magnesium alloy

International Nuclear Information System (INIS)

Jiang, Xiao; Guo, Ruiguang; Jiang, Shuqin

2015-01-01

Highlights: • Through simple chemical conversion process, a Ce–V conversion coating is prepared on AZ31 magnesium alloy. The coating (∼2 μm thick) has a duplex structure and is composed of Mg, Al, Ce, V and O in the outer layer and Mg, Al, V, F and O in the inner layer. • The Ce–V conversion coating can increase the E corr by 157 mV and decrease the i corr by 80 times compared to AZ31 magnesium alloy substrate. Moreover, the performance of the Ce–V conversion coating excels the chromate conversion coating on AZ31 magnesium alloy. • The EIS results of Ce–V conversion coating indicate an increase of 10× in the corrosion resistance and a delay in the corrosion process kinetics compared to uncoated AZ31 magnesium alloy in 3.5 wt.% NaCl solution. • The ball cratering is a simple and effective technique of thickness measurement for chemical conversion coating. - Abstract: A Ce–V conversion coating was developed to improve the corrosion resistance of AZ31 magnesium alloy. Scanning electronic microscope (SEM), energy dispersive X-ray spectroscopy (EDS), X-ray photoelectron spectrometer (XPS), grazing incidence X-ray diffraction (GIXRD) and the ball cratering test were adopted to study the morphology, chemical composition, structure and thickness of the coating. The coating has duplex structure with network and its thickness is about 2 μm. The coating contains high contents of Ce and V, which exhibits amorphous structure. Potentiodynamic polarization shows the coating can increase the corrosion potential and reduce the corrosion current density of AZ31 magnesium alloy. Moreover, the electrochemical impedance spectra exhibit the coating significantly improves the corrosion resistance of AZ31 magnesium alloy. Results indicate that the Ce–V conversion coating can provide effective protection to AZ31 magnesium alloy

Microstructure and corrosion resistance of Ce–V conversion coating on AZ31 magnesium alloy

Energy Technology Data Exchange (ETDEWEB)

Jiang, Xiao, E-mail: xiaoxiao217@126.com; Guo, Ruiguang; Jiang, Shuqin

2015-06-30

Highlights: • Through simple chemical conversion process, a Ce–V conversion coating is prepared on AZ31 magnesium alloy. The coating (∼2 μm thick) has a duplex structure and is composed of Mg, Al, Ce, V and O in the outer layer and Mg, Al, V, F and O in the inner layer. • The Ce–V conversion coating can increase the E{sub corr} by 157 mV and decrease the i{sub corr} by 80 times compared to AZ31 magnesium alloy substrate. Moreover, the performance of the Ce–V conversion coating excels the chromate conversion coating on AZ31 magnesium alloy. • The EIS results of Ce–V conversion coating indicate an increase of 10× in the corrosion resistance and a delay in the corrosion process kinetics compared to uncoated AZ31 magnesium alloy in 3.5 wt.% NaCl solution. • The ball cratering is a simple and effective technique of thickness measurement for chemical conversion coating. - Abstract: A Ce–V conversion coating was developed to improve the corrosion resistance of AZ31 magnesium alloy. Scanning electronic microscope (SEM), energy dispersive X-ray spectroscopy (EDS), X-ray photoelectron spectrometer (XPS), grazing incidence X-ray diffraction (GIXRD) and the ball cratering test were adopted to study the morphology, chemical composition, structure and thickness of the coating. The coating has duplex structure with network and its thickness is about 2 μm. The coating contains high contents of Ce and V, which exhibits amorphous structure. Potentiodynamic polarization shows the coating can increase the corrosion potential and reduce the corrosion current density of AZ31 magnesium alloy. Moreover, the electrochemical impedance spectra exhibit the coating significantly improves the corrosion resistance of AZ31 magnesium alloy. Results indicate that the Ce–V conversion coating can provide effective protection to AZ31 magnesium alloy.

Effect of rare earth elements on high cycle fatigue behavior of AZ91 alloy

International Nuclear Information System (INIS)

Mokhtarishirazabad, M.; Boutorabi, S.M.A.; Azadi, M.; Nikravan, M.

2013-01-01

This article investigates effects of adding rare earth elements (RE) into a magnesium–aluminum–zinc alloy (the AZ91 alloy) on its high cycle fatigue (HCF) behavior. For this purpose, AZ91 and AZ91+1% RE (AZE911) alloys were gravity casted in a metallic die. RE elements were added to the AZ91 alloy in the form of mischmetals. Microscopic evaluations with the scanning electron microscopy (SEM) and mechanical tests include tensile, hardness and HCF behaviors, were performed on prepared samples. Rotary bending fatigue tests were carried out at a stress ratio (R) of −1 and a frequency of 125 Hz, at the room temperature, in the air. The microscopic investigation demonstrates that the addition of 1% RE elements leads to the formation of Al 11 RE 3 intermetallic particles which is associated to the reduction of β-(Mg 17 Al 12 ) phases. Results of mechanical experiments suggest a negligible effect of adding 1% RE elements on mechanical properties of the AZ91 alloy. Curves of stress-life (S–N) shows an increase in the fatigue strength at 10 5 cycles, from 100±10 MPa to 135±10 MPa, when RE elements were added to the AZ91 alloy

Effect of rare earth elements on high cycle fatigue behavior of AZ91 alloy

Energy Technology Data Exchange (ETDEWEB)

Mokhtarishirazabad, M., E-mail: mehdi-mokhtari@hotmail.com [School of Metallurgy and Materials Engineering, Iran University of Science and Technology, Tehran (Iran, Islamic Republic of); Boutorabi, S.M.A. [School of Metallurgy and Materials Engineering, Iran University of Science and Technology, Tehran (Iran, Islamic Republic of); Azadi, M.; Nikravan, M. [Irankhodro Powertrain Company (IPCO), Tehran (Iran, Islamic Republic of)

2013-12-10

This article investigates effects of adding rare earth elements (RE) into a magnesium–aluminum–zinc alloy (the AZ91 alloy) on its high cycle fatigue (HCF) behavior. For this purpose, AZ91 and AZ91+1% RE (AZE911) alloys were gravity casted in a metallic die. RE elements were added to the AZ91 alloy in the form of mischmetals. Microscopic evaluations with the scanning electron microscopy (SEM) and mechanical tests include tensile, hardness and HCF behaviors, were performed on prepared samples. Rotary bending fatigue tests were carried out at a stress ratio (R) of −1 and a frequency of 125 Hz, at the room temperature, in the air. The microscopic investigation demonstrates that the addition of 1% RE elements leads to the formation of Al{sub 11}RE{sub 3} intermetallic particles which is associated to the reduction of β-(Mg{sub 17}Al{sub 12}) phases. Results of mechanical experiments suggest a negligible effect of adding 1% RE elements on mechanical properties of the AZ91 alloy. Curves of stress-life (S–N) shows an increase in the fatigue strength at 10{sup 5} cycles, from 100±10 MPa to 135±10 MPa, when RE elements were added to the AZ91 alloy.

Test Excavations at Painted Rock Reservoir: Sites AZ Z:1:7, AZ Z:1:8, and AZ S:16:36.

Science.gov (United States)

1981-11-01

were dehydrated, trimmed to 12-mm squares, and 77 78 placed in catalyzed (0.05-percent benzoyl peroxide), deinhibited acrylic monomer (50-percent methyl ...refrigeration for 72 hours in partially polymerized ethyl- methyl methacrylate. The methacrylate was polymerized at 50 degrees C and 50 p.s.i. nitrogen...pollen types from fill of Feature 10, AZ Z:l:8 Pollen Type Percent Pinus spp. 0.5 Cheno-Am 92.0 Gramineae 2.0 Ambrosia spp. 0.5 Malvaceae 0.5 Zea spp. 2.0

Analysis of the Deformability of Two-Layer Materials AZ31/Eutectic / Analiza Możliwości Odkształcania Plastycznego Materiału Dwuwarstwowego AZ31/Eutektyka

Directory of Open Access Journals (Sweden)

Mola R.

2015-12-01

Full Text Available The paper present the results of physical simulation of the deformation of the two-layered AZ31/eutectic material using the Gleeble 3800 metallurgical processes simulator. The eutectic layer was produced on the AZ31 substrate using thermochemical treatment. The specimens of AZ31 alloy were heat treated in contact with aluminium powder at 445°C in a vacuum furnace. Depending on the heating time, Al-enriched surface layers with a thickness of 400, 700 and 1100 μm were fabricated on a substrate which was characterized by an eutectic structure composed of the Mg17Al12 phase and a solid solution of aluminium in magnesium. In the study, physical simulation of the fabricated two-layered specimens with a varying thickness of the eutectic layer were deformed using the plane strain compression test at various values of strain rates. The testing results have revealed that it is possible to deform the two-layered AZ31/eutectic material at low strain rates and small deformation values.

Corrosion behaviour of laser surface melted magnesium alloy AZ91D

International Nuclear Information System (INIS)

Taltavull, C.; Torres, B.; Lopez, A.J.; Rodrigo, P.; Otero, E.; Atrens, A.; Rams, J.

2014-01-01

A high power diode laser (HPDL) was used to produce laser surface melting (LSM) treatments on the surface of the Mg alloy AZ91D. Different treatments with different microstructures were produced by varying the laser-beam power and laser-scanning speed. Corrosion evaluation, using hydrogen evolution and electrochemical measurements, led to a relationship between microstructure and corrosion. Most corrosion rates for LSM treated specimens were within the scatter of the as-received AZ91D, whereas some treatments gave higher corrosion rates and some of the samples had corrosion rates lower than the average of the corrosion rate for AZ91D. There were differences in corroded surface morphology. Nevertheless laser treatments introduced surface discontinuities, which masked the effect of the microstructure. Removing these surface defects decreased the corrosion rate for the laser-treated samples. - Highlights: • Corrosion behavior of AZ91D Mg alloys is intimately related with its microstructure. • Laser surface melting treatments allows surface modification of the microstructure. • Different laser parameters can achieve different microstructures. • Controlling laser parameters can produce different corrosion rates and morphologies. • Increase of surface roughness due to laser treatment is relevant to the corrosion rate

Final results of double-shell tank 241-AZ-101 ultrasonic inspection

International Nuclear Information System (INIS)

JENSEN, C.E.

1999-01-01

This document presents the results and documentation of the nondestructive ultrasonic examination of tank 241-AZ-101. A tank inspection supplier was retained to provide and use an ultrasonic examination system (equipment, procedures, and inspectors) to scan a limited area of double-shell tank 241-AZ-101 primary tank wall and welds. The inspection found one reportable indication of thinning and no reportable pitting, corrosion, or cracking

PIB y población desde el periodo tardo colonial hasta 2014: el caso venezolano

OpenAIRE

Giuseppe Bernardo De Corso Sicilia

2018-01-01

El objetivo de este trabajo es múltiple, en primer lugar, propone una serie de población de Venezuela de 1783 a 2015, empleando nuevas estimaciones para el periodo colonial, guerra de independencia e información del censo de 2011, también, se incluye un primer análisis acerca del impacto demográfico de las inmigraciones en el crecimiento de la población en el siglo xx. Por otra parte, se presenta una serie del pib para el periodo 1783-1829. Con la nueva serie de población y del pib se obtiene...

A study on the relationships between corrosion properties and chemistry of thermally oxidised surface films formed on polished commercial magnesium alloys AZ31 and AZ61

International Nuclear Information System (INIS)

Feliu, Sebastián; Samaniego, Alejandro; Barranco, Violeta; El-Hadad, A.A.; Llorente, Irene; Serra, Carmen; Galván, J.C.

2014-01-01

Highlights: • Surface chemistry of heat treated magnesium alloys. • Relation between heat treatment and aluminium subsurface enrichment. • Relation between surface composition and corrosion behaviour. - Abstract: This paper studies the changes in chemical composition of the thin oxide surface films induced by heating in air at 200 °C for time intervals from 5 min to 60 min on the freshly polished commercial AZ31 and AZ61 alloys with a view to better understanding their protective properties. This thermal treatment resulted in the formation of layers enriched in metallic aluminium at the interface between the outer MgO surface films and the bulk material. A strong link was found between the degree of metallic Al enrichment in the subsurface layer (from 10 to 15 at.%) observed by XPS (X-ray photoelectron spectroscopy) in the AZ61 treated samples and the increase in protective properties observed by EIS (electrochemical impedance spectroscopy) in the immersion test in 0.6 M NaCl. Heating for 5–60 min in air at 200 °C seems to be an effective, easy to perform and inexpensive method for increasing the corrosion resistance of the AZ61 alloy by approximately two or three times

A study on the relationships between corrosion properties and chemistry of thermally oxidised surface films formed on polished commercial magnesium alloys AZ31 and AZ61

Energy Technology Data Exchange (ETDEWEB)

Feliu, Sebastián, E-mail: sfeliu@cenim.csic.es [Centro Nacional de Investigaciones Metalúrgicas CSIC, Avda. Gregorio del Amo 8, 28040 Madrid (Spain); Samaniego, Alejandro [Centro Nacional de Investigaciones Metalúrgicas CSIC, Avda. Gregorio del Amo 8, 28040 Madrid (Spain); Barranco, Violeta [Instituto de Ciencias de Materiales de Madrid, ICMM, Consejo Superior de Investigaciones Científicas, CSIC, Sor Juana Inés de la Cruz, 3, Cantoblanco, 28049, Madrid (Spain); El-Hadad, A.A. [Physics Department, Faculty of Science, Al-Azhar University, Nasr City 11884, Cairo (Egypt); Llorente, Irene [Centro Nacional de Investigaciones Metalúrgicas CSIC, Avda. Gregorio del Amo 8, 28040 Madrid (Spain); Serra, Carmen [Servicio de Nanotecnologia y Análisis de Superficies, CACTI, Universidade de Vigo, 36310 Vigo (Spain); Galván, J.C. [Centro Nacional de Investigaciones Metalúrgicas CSIC, Avda. Gregorio del Amo 8, 28040 Madrid (Spain)

2014-03-01

Highlights: • Surface chemistry of heat treated magnesium alloys. • Relation between heat treatment and aluminium subsurface enrichment. • Relation between surface composition and corrosion behaviour. - Abstract: This paper studies the changes in chemical composition of the thin oxide surface films induced by heating in air at 200 °C for time intervals from 5 min to 60 min on the freshly polished commercial AZ31 and AZ61 alloys with a view to better understanding their protective properties. This thermal treatment resulted in the formation of layers enriched in metallic aluminium at the interface between the outer MgO surface films and the bulk material. A strong link was found between the degree of metallic Al enrichment in the subsurface layer (from 10 to 15 at.%) observed by XPS (X-ray photoelectron spectroscopy) in the AZ61 treated samples and the increase in protective properties observed by EIS (electrochemical impedance spectroscopy) in the immersion test in 0.6 M NaCl. Heating for 5–60 min in air at 200 °C seems to be an effective, easy to perform and inexpensive method for increasing the corrosion resistance of the AZ61 alloy by approximately two or three times.

Biodegradable behaviors of AZ31 magnesium alloy in simulated body fluid

International Nuclear Information System (INIS)

Song Yingwei; Shan Dayong; Chen Rongshi; Zhang Fan; Han Enhou

2009-01-01

Magnesium alloys have unique advantages to act as biodegradable implants for clinical application. The biodegradable behaviors of AZ31 in simulated body fluid (SBF) for various immersion time intervals were investigated by electrochemical impedance spectroscopy (EIS) tests and scanning electron microscope (SEM) observation, and then the biodegradable mechanisms were discussed. It was found that a protective film layer was formed on the surface of AZ31 in SBF. With increasing of immersion time, the film layer became more compact. If the immersion time was more than 24 h, the film layer began to degenerate and emerge corrosion pits. In the meantime, there was hydroxyapatite particles deposited on the film layer. The hydroxyapatite is the essential component of human bone, which indicates the perfect biocompatibility of AZ31 magnesium alloy.

Study on fused/cast AZS refractories for deployment in vitrification of radioactive waste effluents

Energy Technology Data Exchange (ETDEWEB)

Sengupta, Pranesh, E-mail: praneshsengupta@gmail.com [Materials Science Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India); Mishra, R.K.; Soudamini, N. [Waste Management Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India); Sen, D.; Mazumder, S. [Solid State Physics Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India); Kaushik, C.P. [Waste Management Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India); Ajithkumar, T.G. [Central NMR Facility, National Chemical Laboratory, Pune 411 008 (India); Banerjee, K. [Nuclear Recycle Group, Mumbai 400 085 (India)

2015-12-15

‘Fused/cast Al{sub 2}O{sub 3}–ZrO{sub 2}–SiO{sub 2} (FC-AZS)’ is being considered as ‘glass contact refractory’ within ceramic melters, to be used for nuclear waste immobilization. Microstructural analyses reveal random distributions of baddeleyite (ZrO{sub 2}) within aluminosilicate (Al{sub 2}SiO{sub 5}) matrix. {sup 27}Al and {sup 29}Si NMR data suggest that within aluminosilicate matrix Al occurs in both 4- and 6-fold co-ordinations whereas Si prefers a 4-fold environment. Polydispersity of pores has been studied with small-angle neutron scattering (SANS) technique. Corrosion rates of FC-AZS within 6 M HNO{sub 3}, simulated wastes (500 h exposure), and borosilicate melt (975 °C, 800 h exposure) are found to be 0.38 × 10{sup 3} μmy{sup −1}, 0.13 × 10{sup 3} μmy{sup −1} and 4.75 × 10{sup 3} μmy{sup −1} respectively. A comparison of chemical interaction data clearly suggests that FC-AZS exhibits better chemical durability than AZC refractory (Al{sub 2}O{sub 3}–ZrO{sub 2}–Cr{sub 2}O{sub 3}, also used for similar purpose). Thermal cycling studies indicate that FC-AZS retains structural integrity (including compressive strength and density) even up to 20 cycles. - Highlights: • Vitrification of nuclear waste using AZS refractory within ceramic melter. • Microstructure of AZS refractory. • Interaction of AZS with simulated high level waste and glass.

CESIUM REMOVAL FROM TANKS 241-AN-103 & 241-SX-105 & 241-AZ-101 & 241AZ-102 COMPOSITE FOR TESTING IN BENCH SCALE STEAM REFORMER

Energy Technology Data Exchange (ETDEWEB)

DUNCAN JB; HUBER HJ

2011-04-21

This report documents the preparation of three actual Hanford tank waste samples for shipment to the Savannah River National Laboratory (SRNL). Two of the samples were dissolved saltcakes from tank 241-AN-103 (hereafter AN-103) and tank 241-SX-105 (hereafter SX-105); one sample was a supernate composite from tanks 241-AZ-101 and 241-AZ-102 (hereafter AZ-101/102). The preparation of the samples was executed following the test plans LAB-PLAN-10-00006, Test Plan for the Preparation of Samples from Hanford Tanks 241-SX-105, 241-AN-103, 241-AN-107, and LAB-PLN-l0-00014, Test Plan for the Preparation of a Composite Sample from Hanford Tanks 241-AZ-101 and 241-AZ-102 for Steam Reformer Testing at the Savannah River National Laboratory. All procedural steps were recorded in laboratory notebook HNF-N-274 3. Sample breakdown diagrams for AN-103 and SX-105 are presented in Appendix A. The tank samples were prepared in support of a series of treatability studies of the Fluidized Bed Steam Reforming (FBSR) process using a Bench-Scale Reformer (BSR) at SRNL. Tests with simulants have shown that the FBSR mineralized waste form is comparable to low-activity waste glass with respect to environmental durability (WSRC-STI-2008-00268, Mineralization of Radioactive Wastes by Fluidized Bed Steam Reforming (FBSR): Comparisons to Vitreous Waste Forms and Pertinent Durability Testing). However, a rigorous assessment requires long-term performance data from FBSR product formed from actual Hanford tank waste. Washington River Protection Solutions, LLC (WRPS) has initiated a Waste Form Qualification Program (WP-5.2.1-2010-001, Fluidized Bed Steam Reformer Low-level Waste Form Qualification) to gather the data required to demonstrate that an adequate FBSR mineralized waste form can be produced. The documentation of the selection process of the three tank samples has been separately reported in RPP-48824, Sample Selection Process for Bench-Scale Steam Reforming Treatability Studies Using

Neodymium-140 DOTA-LM3

DEFF Research Database (Denmark)

Severin, Gregory; Kristensen, Lotte K.; Nielsen, Carsten H.

2017-01-01

analogue, DOTA-LM3 (1,4,7,10- tetraazacyclododecane, 1,4,7- tri acetic acid, 10- acetamide N - p-Cl-Phecyclo(D-Cys-Tyr-d-4-amino-Phe(carbamoyl)-Lys-Thr-Cys)D-Tyr-NH2) and injected into H727 xenograft bearing mice. Comparative pre- and post-mortem PET imaging at 16 h postinjection was used to quantify......140Nd (t1/2 = 3.4 days), owing to its short-lived positron emitting daughter 140Pr (t1/2 = 3.4 min), has promise as an in vivo generator for positron emission tomography (PET). However, the electron capture decay of 140Nd is chemically disruptive to macrocycle-based radiolabeling, meaning...... the in vivo redistribution of 140Pr following 140Nd decay. The somatostatin receptor-positive pancreas exhibited the highest tissue accumulation of 140Nd-DOTA-LM3 (13% ID/g at 16 h) coupled with the largest observed redistribution rate, where 56 ± 7% (n = 4, mean ± SD) of the in situ produced 140Pr washed out...

22 CFR 140.5 - Overview.

Science.gov (United States)

2010-04-01

...). Section 140.7 establishes the procedures applicable to multilateral institutions and international organizations. Section 140.8 establishes the procedures applicable to recipients of scholarships and fellowships and participant trainees. Section 140.9 establishes the procedures applicable to non-governmental...

Rapid coating of AZ31 magnesium alloy with calcium deficient hydroxyapatite using microwave energy

International Nuclear Information System (INIS)

Ren, Yufu; Zhou, Huan; Nabiyouni, Maryam; Bhaduri, Sarit B.

2015-01-01

Due to their unique biodegradability, magnesium alloys have been recognized as suitable metallic implant materials for degradable bone implants and bioresorbable cardiovascular stents. However, the extremely high degradation rate of magnesium alloys in physiological environment has restricted its practical application. This paper reports the use of a novel microwave assisted coating technology to improve the in vitro corrosion resistance and biocompatibility of Mg alloy AZ31. Results indicate that a dense calcium deficient hydroxyapatite (CDHA) layer was uniformly coated on a AZ31 substrate in less than 10 min. Weight loss measurement and SEM were used to evaluate corrosion behaviors in vitro of coated samples and of non-coated samples. It was seen that CDHA coatings remarkably reduced the mass loss of AZ31 alloy after 7 days of immersion in SBF. In addition, the prompt precipitation of bone-like apatite layer on the sample surface during immersion demonstrated a good bioactivity of the CDHA coatings. Proliferation of osteoblast cells was promoted in 5 days of incubation, which indicated that the CDHA coatings could improve the cytocompatibility of the AZ31 alloy. All the results suggest that the CDHA coatings, serving as a protective layer, can enhance the corrosion resistance and biological response of magnesium alloys. Furthermore, this microwave assisted coating technology could be a promising method for rapid surface modification of biomedical materials. - Highlights: • A microwave assisted coating process for biodegradable Mg alloy. • CDHA coatings were successfully developed on AZ31 alloy in minutes. • The as-deposited CDHA coatings significantly reduced the degradation rate of AZ31 alloy. • The CDHA coated AZ31 alloy showed good bioactivity and biocompatibility in vitro. • The microwave assisted coating process can be used as rapid surface modification for bioimplants

Rapid coating of AZ31 magnesium alloy with calcium deficient hydroxyapatite using microwave energy

Energy Technology Data Exchange (ETDEWEB)

Ren, Yufu, E-mail: Yufu.Ren@rockets.utoledo.edu [Department of Mechanical, Industrial and Manufacturing Engineering, The University of Toledo, Toledo, OH (United States); Zhou, Huan [Department of Mechanical, Industrial and Manufacturing Engineering, The University of Toledo, Toledo, OH (United States); Institute of Biomedical Engineering and Health Sciences, Changzhou University, Changzhou, Jiangsu (China); Nabiyouni, Maryam [Department of Bioengineering, The University of Toledo, Toledo, OH (United States); Bhaduri, Sarit B. [Department of Mechanical, Industrial and Manufacturing Engineering, The University of Toledo, Toledo, OH (United States); Division of Dentistry, The University of Toledo, Toledo, OH (United States)

2015-04-01

Due to their unique biodegradability, magnesium alloys have been recognized as suitable metallic implant materials for degradable bone implants and bioresorbable cardiovascular stents. However, the extremely high degradation rate of magnesium alloys in physiological environment has restricted its practical application. This paper reports the use of a novel microwave assisted coating technology to improve the in vitro corrosion resistance and biocompatibility of Mg alloy AZ31. Results indicate that a dense calcium deficient hydroxyapatite (CDHA) layer was uniformly coated on a AZ31 substrate in less than 10 min. Weight loss measurement and SEM were used to evaluate corrosion behaviors in vitro of coated samples and of non-coated samples. It was seen that CDHA coatings remarkably reduced the mass loss of AZ31 alloy after 7 days of immersion in SBF. In addition, the prompt precipitation of bone-like apatite layer on the sample surface during immersion demonstrated a good bioactivity of the CDHA coatings. Proliferation of osteoblast cells was promoted in 5 days of incubation, which indicated that the CDHA coatings could improve the cytocompatibility of the AZ31 alloy. All the results suggest that the CDHA coatings, serving as a protective layer, can enhance the corrosion resistance and biological response of magnesium alloys. Furthermore, this microwave assisted coating technology could be a promising method for rapid surface modification of biomedical materials. - Highlights: • A microwave assisted coating process for biodegradable Mg alloy. • CDHA coatings were successfully developed on AZ31 alloy in minutes. • The as-deposited CDHA coatings significantly reduced the degradation rate of AZ31 alloy. • The CDHA coated AZ31 alloy showed good bioactivity and biocompatibility in vitro. • The microwave assisted coating process can be used as rapid surface modification for bioimplants.

Operational Test Report for the 241-AZ-101 Suspended Solids Profiler

International Nuclear Information System (INIS)

STENKAMP, D.M.

2000-01-01

This document comprises the Operational Test Report for the 241-AZ-101 Suspended Solids Profiler. This document presents the results of Operational Testing of the 241-AZ-101 Suspended Solids Profiler (SSP). Testing of the SSP was performed in accordance with OTP-260-005, ''SUSPENDED SOLIDS PROFILER OPERATIONAL TEST PROCEDURE''. The objective of the testing was to verify that all equipment and components functioned as designed, following construction completion and turnover to operations

23 CFR 140.912 - Transportation.

Science.gov (United States)

2010-04-01

... 23 Highways 1 2010-04-01 2010-04-01 false Transportation. 140.912 Section 140.912 Highways FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION PAYMENT PROCEDURES REIMBURSEMENT Reimbursement for Railroad Work § 140.912 Transportation. (a) Employees. The company's cost of necessary employee...

Tiwanaku influence and social inequality: A bioarchaeological, biogeochemical, and contextual analysis of the Larache cemetery, San Pedro de Atacama, Northern Chile.

Science.gov (United States)

Torres-Rouff, Christina; Knudson, Kelly J; Pestle, William J; Stovel, Emily M

2015-12-01

To assess the relationship between the Tiwanaku polity and the individuals buried at the Middle Horizon (∼AD500-1000) cemetery of Larache in northern Chile, a site that has been singled out as a potential elite foreign enclave. We explore this association through the skeletal remains of 48 individuals interred at the cemetery of Larache using bioarchaeological, biogeochemical, and artifactual evidence. Data from cranial modification practices, violent injury, and the mortuary assemblage are used to explore culturally constructed elements of status and identity, radiogenic strontium isotope analyses provide us with a perspective on the geographic origins of these individuals, and stable carbon and nitrogen analyses allow discussion of paleodiet and access to resources. Radiogenic strontium isotope values show the presence of multiple first generation migrants at Larache. Stable carbon and nitrogen isotope data reveal significant differences among individuals. The mortuary context reveals a standard pattern for the oases but also includes a series of unusual burials with abundant gold and few other objects. Interestingly, both local and nonlocal individuals with different head shapes had access to the differentiated burial context; however nonlocal individuals appear to be the only ones with a heavily maize-based diet. Our evidence shows that Larache served as a burial place for a diverse, yet culturally integrated and potentially elite segment of the Atacameño population, but not a foreign enclave as had been postulated. © 2015 Wiley Periodicals, Inc.

10 CFR 140.5 - Communications.

Science.gov (United States)

2010-01-01

... 10 Energy 2 2010-01-01 2010-01-01 false Communications. 140.5 Section 140.5 Energy NUCLEAR... Provisions § 140.5 Communications. Except where otherwise specified, all communications and reports... Reactors, Director, Office of Federal and State Materials and Environmental Management Programs, or...

23 CFR 140.916 - Protection.

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2010-04-01

... 23 Highways 1 2010-04-01 2010-04-01 false Protection. 140.916 Section 140.916 Highways FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION PAYMENT PROCEDURES REIMBURSEMENT Reimbursement for Railroad Work § 140.916 Protection. The cost of essential protective services which, in the opinion of a...

5 CFR 2416.140 - Employment.

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2010-01-01

... 5 Administrative Personnel 3 2010-01-01 2010-01-01 false Employment. 2416.140 Section 2416.140....140 Employment. No qualified individual with disabilities shall, on the basis of disability, be subject to discrimination in employment under any program or activity conducted by the agency. The...

49 CFR 1014.140 - Employment.

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2010-10-01

... 49 Transportation 8 2010-10-01 2010-10-01 false Employment. 1014.140 Section 1014.140... HANDICAP IN PROGRAMS OR ACTIVITIES CONDUCTED BY THE SURFACE TRANSPORTATION BOARD § 1014.140 Employment. No qualified handicapped person shall, on the basis of handicap, be subjected to discrimination in employment...

40 CFR 12.140 - Employment.

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2010-07-01

... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Employment. 12.140 Section 12.140... IN PROGRAMS OR ACTIVITIES CONDUCTED BY THE ENVIRONMENTAL PROTECTION AGENCY § 12.140 Employment. No... employment under any program or activity conducted by the agency. The definitions, requirements, and...

45 CFR 1214.140 - Employment.

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2010-10-01

... 45 Public Welfare 4 2010-10-01 2010-10-01 false Employment. 1214.140 Section 1214.140 Public....140 Employment. No qualified individual with handicaps shall, on the basis of handicap, be subjected to discrimination in employment under any program or activity conducted by the agency. The...

10 CFR 140.1 - Purpose.

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2010-01-01

... 10 Energy 2 2010-01-01 2010-01-01 false Purpose. 140.1 Section 140.1 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) FINANCIAL PROTECTION REQUIREMENTS AND INDEMNITY AGREEMENTS General Provisions § 140.1 Purpose. The regulations in this part are issued to provide appropriate procedures and requirements for...

1 CFR 500.140 - Employment.

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2010-01-01

... 1 General Provisions 1 2010-01-01 2010-01-01 false Employment. 500.140 Section 500.140 General... ACTIVITIES CONDUCTED BY THE NATIONAL COMMISSION FOR EMPLOYMENT POLICY § 500.140 Employment. No qualified handicapped person shall, on the basis of handicap, be subjected to discrimination in employment under any...

5 CFR 1850.140 - Employment.

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2010-01-01

... 5 Administrative Personnel 3 2010-01-01 2010-01-01 false Employment. 1850.140 Section 1850.140... PROGRAMS OR ACTIVITIES CONDUCTED BY THE OFFICE OF SPECIAL COUNSEL § 1850.140 Employment. No qualified individual with handicaps shall, on the basis of handicap, be subject to discrimination in employment under...

3 CFR 102.140 - Employment.

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2010-01-01

... 3 The President 1 2010-01-01 2010-01-01 false Employment. 102.140 Section 102.140 Presidential... PROGRAMS OR ACTIVITIES CONDUCTED BY THE EXECUTIVE OFFICE OF THE PRESIDENT § 102.140 Employment. No... employment under any program or activity conducted by the agency. The definitions, requirements, and...

20 CFR 365.140 - Employment.

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2010-04-01

... 20 Employees' Benefits 1 2010-04-01 2010-04-01 false Employment. 365.140 Section 365.140 Employees... § 365.140 Employment. No qualified individual with handicaps shall, on the basis of handicap, be subjected to discrimination in employment under any program or activity conducted by the agency. The...

45 CFR 1175.140 - Employment.

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2010-10-01

... 45 Public Welfare 3 2010-10-01 2010-10-01 false Employment. 1175.140 Section 1175.140 Public... PROGRAMS OR ACTIVITIES CONDUCTED BY THE NATIONAL ENDOWMENT FOR THE HUMANITIES § 1175.140 Employment. No qualified handicapped person shall, on the basis of handicap, be subjected to discrimination in employment...

49 CFR 807.140 - Employment.

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2010-10-01

... 49 Transportation 7 2010-10-01 2010-10-01 false Employment. 807.140 Section 807.140 Transportation... TRANSPORTATION SAFETY BOARD § 807.140 Employment. No qualified handicapped person shall, on the basis of handicap, be subjected to discrimination in employment under any program or activity conducted by the agency...

34 CFR 1200.140 - Employment.

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2010-07-01

... 34 Education 3 2010-07-01 2010-07-01 false Employment. 1200.140 Section 1200.140 Education... COUNCIL ON DISABILITY § 1200.140 Employment. No qualified individual with handicaps shall, on the basis of handicap, be subjected to discrimination in employment under any program or activity conducted by the...

5 CFR 723.140 - Employment.

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2010-01-01

... 5 Administrative Personnel 2 2010-01-01 2010-01-01 false Employment. 723.140 Section 723.140... PERSONNEL MANAGEMENT § 723.140 Employment. No qualified individual with handicaps shall, on the basis of handicap, be subject to discrimination in employment under any program or activity conducted by the agency...

22 CFR 1005.140 - Employment.

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2010-04-01

... 22 Foreign Relations 2 2010-04-01 2010-04-01 true Employment. 1005.140 Section 1005.140 Foreign... ACTIVITIES CONDUCTED BY THE INTER-AMERICAN FOUNDATION § 1005.140 Employment. No qualified handicapped person shall, on the basis of handicap, be subjected to discrimination in employment under any program or...

45 CFR 2104.140 - Employment.

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2010-10-01

... 45 Public Welfare 4 2010-10-01 2010-10-01 false Employment. 2104.140 Section 2104.140 Public....140 Employment. No qualified handicapped person shall, on the basis of handicap, be subjected to discrimination in employment under any program or activity conducted by the agency. The definitions, requirements...

5 CFR 1636.140 - Employment.

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2010-01-01

... 5 Administrative Personnel 3 2010-01-01 2010-01-01 false Employment. 1636.140 Section 1636.140... § 1636.140 Employment. No qualified individual with handicaps shall, on the basis of handicap, be subjected to discrimination in employment under any program or activity conducted by the agency. The...

22 CFR 219.140 - Employment.

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2010-04-01

... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Employment. 219.140 Section 219.140 Foreign... DEVELOPMENT § 219.140 Employment. No qualified handicapped person shall, on the basis of handicap, be subjected to discrimination in employment under any program or activity conducted by the agency. The...

50 CFR 550.140 - Employment.

Science.gov (United States)

2010-10-01

... 50 Wildlife and Fisheries 7 2010-10-01 2010-10-01 false Employment. 550.140 Section 550.140... IN PROGRAMS OR ACTIVITIES CONDUCTED BY MARINE MAMMAL COMMISSION § 550.140 Employment. No qualified handicapped person shall, on the basis of handicap, be subjected to discrimination in employment under any...

45 CFR 1706.140 - Employment.

Science.gov (United States)

2010-10-01

... 45 Public Welfare 4 2010-10-01 2010-10-01 false Employment. 1706.140 Section 1706.140 Public... CONDUCTED BY NATIONAL COMMISSION ON LIBRARIES AND INFORMATION SCIENCE § 1706.140 Employment. No qualified handicapped person shall, on the basis of handicap, be subjected to discrimination in employment under any...

29 CFR 2205.140 - Employment.

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2010-07-01

... 29 Labor 9 2010-07-01 2010-07-01 false Employment. 2205.140 Section 2205.140 Labor Regulations... REVIEW COMMISSION § 2205.140 Employment. No qualified handicapped person shall, on the basis of handicap, be subjected to discrimination in employment under any program or activity conducted by the agency...

1 CFR 457.140 - Employment.

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2010-01-01

... 1 General Provisions 1 2010-01-01 2010-01-01 false Employment. 457.140 Section 457.140 General... ACTIVITIES CONDUCTED BY THE NATIONAL CAPITAL PLANNING COMMISSION § 457.140 Employment. No qualified handicapped person shall, on the basis of handicap, be subjected to discrimination in employment under any...

45 CFR 2490.140 - Employment.

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2010-10-01

... 45 Public Welfare 4 2010-10-01 2010-10-01 false Employment. 2490.140 Section 2490.140 Public... MADISON MEMORIAL FELLOWSHIP FOUNDATION § 2490.140 Employment. No qualified individual with handicaps shall, on the basis of handicap, be subjected to discrimination in employment under any program or activity...

22 CFR 1701.140 - Employment.

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2010-04-01

... 22 Foreign Relations 2 2010-04-01 2010-04-01 true Employment. 1701.140 Section 1701.140 Foreign... PROGRAMS OR ACTIVITIES CONDUCTED BY THE UNITED STATES INSTITUTE OF PEACE § 1701.140 Employment. No... employment under any program or activity conducted by the agency. The definitions, requirements, and...

22 CFR 1103.140 - Employment.

Science.gov (United States)

2010-04-01

... 22 Foreign Relations 2 2010-04-01 2010-04-01 true Employment. 1103.140 Section 1103.140 Foreign... BOUNDARY AND WATER COMMISSION, UNITED STATES AND MEXICO, UNITED STATES SECTION § 1103.140 Employment. No qualified handicapped person shall, on the basis of handicap, be subjected to discrimination in employment...

22 CFR 1510.140 - Employment.

Science.gov (United States)

2010-04-01

... 22 Foreign Relations 2 2010-04-01 2010-04-01 true Employment. 1510.140 Section 1510.140 Foreign... PROGRAMS OR ACTIVITIES CONDUCTED BY THE AFRICAN DEVELOPMENT FOUNDATION § 1510.140 Employment. No qualified individual with handicaps shall, on the basis of handicap, be subject to discrimination in employment under...

11 CFR 6.140 - Employment.

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2010-01-01

... 11 Federal Elections 1 2010-01-01 2010-01-01 false Employment. 6.140 Section 6.140 Federal... OR ACTIVITIES CONDUCTED BY THE FEDERAL ELECTION COMMISSION § 6.140 Employment. No qualified handicapped person shall, on the basis of handicap, be subjected to discrimination in employment under any...

22 CFR 144.140 - Employment.

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2010-04-01

... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Employment. 144.140 Section 144.140 Foreign... PROGRAMS OR ACTIVITIES CONDUCTED BY THE UNITED STATES DEPARTMENT OF STATE § 144.140 Employment. No qualified handicapped person shall, on the basis of handicap, be subjected to discrimination in employment...

46 CFR 507.140 - Employment.

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2010-10-01

... 46 Shipping 9 2010-10-01 2010-10-01 false Employment. 507.140 Section 507.140 Shipping FEDERAL... HANDICAP IN PROGRAMS OR ACTIVITIES CONDUCTED BY THE FEDERAL MARITIME COMMISSION § 507.140 Employment. No qualified handicapped person shall, on the basis of handicap, be subjected to discrimination in employment...

29 CFR 4907.140 - Employment.

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2010-07-01

... 29 Labor 9 2010-07-01 2010-07-01 false Employment. 4907.140 Section 4907.140 Labor Regulations... THE PENSION BENEFIT GUARANTY CORPORATION § 4907.140 Employment. No qualified handicapped person shall, on the basis of handicap, be subjected to discrimination in employment under any program or activity...

29 CFR 2706.140 - Employment.

Science.gov (United States)

2010-07-01

... 29 Labor 9 2010-07-01 2010-07-01 false Employment. 2706.140 Section 2706.140 Labor Regulations... REVIEW COMMISSION § 2706.140 Employment. No qualified handicapped person shall, on the basis of handicap, be subjected to discrimination in employment under any program or activity conducted by the agency...

40 CFR 46.140 - Benefits.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Benefits. 46.140 Section 46.140 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GRANTS AND OTHER FEDERAL ASSISTANCE FELLOWSHIPS Applying for Fellowships § 46.140 Benefits. EPA fellowships may include funds to help you pay such things...

49 CFR 28.140 - Employment.

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2010-10-01

... 49 Transportation 1 2010-10-01 2010-10-01 false Employment. 28.140 Section 28.140 Transportation Office of the Secretary of Transportation ENFORCEMENT OF NONDISCRIMINATION ON THE BASIS OF HANDICAP IN PROGRAMS OR ACTIVITIES CONDUCTED BY THE DEPARTMENT OF TRANSPORTATION § 28.140 Employment. (a) No qualified...

45 CFR 2301.140 - Employment.

Science.gov (United States)

2010-10-01

... 45 Public Welfare 4 2010-10-01 2010-10-01 false Employment. 2301.140 Section 2301.140 Public... COMMISSION § 2301.140 Employment. No qualified individual with handicaps shall, on the basis of handicap, be subjected to discrimination in employment under any program or activity conducted by the agency. The...

22 CFR 711.140 - Employment.

Science.gov (United States)

2010-04-01

... 22 Foreign Relations 2 2010-04-01 2010-04-01 true Employment. 711.140 Section 711.140 Foreign... CORPORATION § 711.140 Employment. No qualified individual with handicaps shall, on the basis of handicap, be subject to discrimination in employment under any program or activity conducted by the agency. The...

24 CFR 9.140 - Employment.

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2010-04-01

... 24 Housing and Urban Development 1 2010-04-01 2010-04-01 false Employment. 9.140 Section 9.140... DEPARTMENT OF HOUSING AND URBAN DEVELOPMENT § 9.140 Employment. No qualified individual with disabilities shall, on the basis of disability, be subjected to discrimination in employment under any program or...

45 CFR 1153.140 - Employment.

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2010-10-01

... 45 Public Welfare 3 2010-10-01 2010-10-01 false Employment. 1153.140 Section 1153.140 Public... PROGRAMS OR ACTIVITIES CONDUCTED BY THE NATIONAL ENDOWMENT FOR THE ARTS § 1153.140 Employment. No qualified handicapped person shall, on the basis of handicap, be subjected to discrimination in employment under any...

19 CFR 201.140 - Employment.

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2010-04-01

... 19 Customs Duties 3 2010-04-01 2010-04-01 false Employment. 201.140 Section 201.140 Customs Duties... Commission § 201.140 Employment. No qualified handicapped person shall, on the basis of handicap, be subjected to discrimination in employment under any program or activity conducted by the agency. The...

22 CFR 530.140 - Employment.

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2010-04-01

... 22 Foreign Relations 2 2010-04-01 2010-04-01 true Employment. 530.140 Section 530.140 Foreign... PROGRAMS OR ACTIVITIES CONDUCTED BY THE BROADCASTING BOARD OF GOVERNORS § 530.140 Employment. No qualified handicapped person shall, on the basis of handicap, be subjected to discrimination in employment under any...

28 CFR 39.140 - Employment.

Science.gov (United States)

2010-07-01

... 28 Judicial Administration 1 2010-07-01 2010-07-01 false Employment. 39.140 Section 39.140... PROGRAMS OR ACTIVITIES CONDUCTED BY THE DEPARTMENT OF JUSTICE § 39.140 Employment. No qualified handicapped person shall, on the basis of handicap, be subjected to discrimination in employment under any program or...

25 CFR 720.140 - Employment.

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2010-04-01

... 25 Indians 2 2010-04-01 2010-04-01 false Employment. 720.140 Section 720.140 Indians THE OFFICE OF... OR ACTIVITIES CONDUCTED BY THE NAVAJO AND HOPI INDIAN RELOCATION COMMISSION § 720.140 Employment. No qualified handicapped person shall, on the basis of handicap, be subjected to discrimination in employment...

10 CFR 1041.140 - Employment.

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2010-01-01

... 10 Energy 4 2010-01-01 2010-01-01 false Employment. 1041.140 Section 1041.140 Energy DEPARTMENT OF... ACTIVITIES CONDUCTED BY THE DEPARTMENT OF ENERGY § 1041.140 Employment. No qualified handicapped person shall, on the basis of handicap, be subjected to discrimination in employment under any program or activity...

23 CFR 140.607 - Construction.

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2010-04-01

... 23 Highways 1 2010-04-01 2010-04-01 false Construction. 140.607 Section 140.607 Highways FEDERAL... Bond Issue Projects § 140.607 Construction. Construction shall be supervised by the SHA in the same manner as for regularly financed Federal-aid projects. The FHWA will make construction inspections and...

Corrosion and mechanical performance of AZ91 exposed to simulated inflammatory conditions.

Science.gov (United States)

Brooks, Emily K; Der, Stephanie; Ehrensberger, Mark T

2016-03-01

Magnesium (Mg) and its alloys, including Mg-9%Al-1%Zn (AZ91), are biodegradable metals with potential use as temporary orthopedic implants. Invasive orthopedic procedures can provoke an inflammatory response that produces hydrogen peroxide (H2O2) and an acidic environment near the implant. This study assessed the influence of inflammation on both the corrosion and mechanical properties of AZ91. The AZ91 samples in the inflammatory protocol were immersed for three days in a complex biologically relevant electrolyte (AMEM culture media) that contained serum proteins (FBS), 150 mM of H2O2, and was titrated to a pH of 5. The control protocol immersed AZ91 samples in the same biologically relevant electrolyte (AMEM & FBS) but without H2O2 and the acid titration. After 3 days all samples were switched into fresh AMEM & FBS for an additional 3-day immersion. During the initial immersion, inflammatory protocol samples showed increased corrosion rate determined by mass loss testing, increased Mg and Al ion released to solution, and a completely corroded surface morphology as compared to the control protocol. Although corrosion in both protocols slowed once the test electrolyte solution was replaced at 3 days, the samples originally exposed to the simulated inflammatory conditions continued to display enhanced corrosion rates as compared to the control protocol. These lingering effects may indicate the initial inflammatory corrosion processes modified components of the surface oxide and corrosion film or initiated aggressive localized processes that subsequently left the interface more vulnerable to continued enhanced corrosion. The electrochemical properties of the interfaces were also evaluated by EIS, which found that the corrosion characteristics of the AZ91 samples were potentially influenced by the role of intermediate adsorption layer processes. The increased corrosion observed for the inflammatory protocol did not affect the flexural mechanical properties of the AZ91

Tank 241-AZ-101 Mixer Pump Test Vapor Sampling and Analysis Plan

International Nuclear Information System (INIS)

TEMPLETON, A.M.

2000-01-01

This sampling and analysis plan (SAP) identifies characterization objectives pertaining to sample collection, laboratory analytical evaluation, and reporting requirements for vapor samples obtained during the operation of mixer pumps in tank 241-AZ-101. The primary purpose of the mixer pump test (MPT) is to demonstrate that the two 300 horsepower mixer pumps installed in tank 241-AZ-101 can mobilize the settled sludge so that it can be retrieved for treatment and vitrification. Sampling will be performed in accordance with Tank 241-AZ-101 Mixer Pump Test Data Quality Objective (Banning 1999) and Data Quality Objectives for Regulatory Requirements for Hazardous and Radioactive Air Emissions Sampling and Analysis (Mulkey 1999). The sampling will verify if current air emission estimates used in the permit application are correct and provide information for future air permit applications

42 CFR 457.140 - Budget.

Science.gov (United States)

2010-10-01

... 42 Public Health 4 2010-10-01 2010-10-01 false Budget. 457.140 Section 457.140 Public Health... Child Health Insurance Programs and Outreach Strategies § 457.140 Budget. The State plan, or plan amendment that has a significant impact on the approved budget, must include a budget that describes the...

25 CFR 140.21 - Gambling.

Science.gov (United States)

2010-04-01

... 25 Indians 1 2010-04-01 2010-04-01 false Gambling. 140.21 Section 140.21 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR FINANCIAL ACTIVITIES LICENSED INDIAN TRADERS § 140.21 Gambling. Gambling, by dice, cards, or in any way whatever, is strictly prohibited in any licensed trader's store or...

12 CFR 410.140 - Employment.

Science.gov (United States)

2010-01-01

... 12 Banks and Banking 4 2010-01-01 2010-01-01 false Employment. 410.140 Section 410.140 Banks and Banking EXPORT-IMPORT BANK OF THE UNITED STATES ENFORCEMENT OF NONDISCRIMINATION ON THE BASIS OF HANDICAP IN PROGRAMS OR ACTIVITIES CONDUCTED BY EXPORT-IMPORT BANK OF THE UNITED STATES § 410.140 Employment...

Microstructures of friction welded joints of AZ31 to AM60 magnesium alloys

Energy Technology Data Exchange (ETDEWEB)

Fukumoto, S.; Ono, T.; Tanaka, S.; Tsubakino, H. [Graduate School of Engineering, Himeji Inst. of Tech., Hyogo (Japan); Tomita, T.; Aritoshi, M. [Hyogo Prefectural Inst. of Industrial Research, Kobe, Hyogo (Japan); Okita, K. [Inst. of Industrial Research, Osaka Sangyo Univ., Osaka (Japan)

2003-07-01

AZ31 magnesium alloy was friction-welded to AM60 and the microstructures and the friction welding process were studied. The microstructures changed near the weld interface. The AZ31 was refined to a grain size of several {mu}m near the weld interface. The nucleation occurred in the shear bands that were introduced during the welding process. On the other hand, the eutectic structure was deformed and the lamellar structure which was composed of {alpha}-Mg and Mg{sub 17}Al{sub 12} was formed near the weld interface in AM60 alloy. In the friction process, the adhesion and peel off occurred alternately between AZ31 and AM60. Eventually, bonding was completed during upset process. (orig.)

Influencia de compuestos azúcares y no azúcares en la calidad industrial de caña de azúcar en Tucumán (R. Argentina: Parte 1: caña limpia y despuntada Influence of sugar and nonsugar compounds on sugarcane industrial quality in Tucumán (Argentine Republic

Directory of Open Access Journals (Sweden)

B. Silvia Zossi

Full Text Available Se estudió la concentración de compuestos azúcares y no azúcares, especialmente los que influyen en la formación del color y otros que inciden en el proceso industrial de producción de azúcar blanco directo, de las cuatro variedades comerciales de caña más difundidas en Tucumán (R. Argentina: TUCCP 77-42, LCP 85-384, CP 65-357 y RA 87-3. Estos ensayos fueron realizados durante las zafras 2004 a 2007 en caña limpia y despuntada. Los parámetros analizados fueron: extracción de jugo, Brix %, pol % en jugo y en caña, sacarosa y azúcar recuperable. Se estudiaron no azúcares inorgánicos, tales como cenizas, fosfato y sílice, y no azúcares orgánicos: fibra, almidón, compuestos antocianos y fenoles, nitrógeno amínico, ácidos cis y trans-aconítico, "indicator value" y color. De las cuatro variedades analizadas, la que mejor comportamiento presentó para producir azúcar blanco directo fue LCP 85-384, por su alto contenido en sacarosa y bajo contenido de componentes no azúcares. El segundo lugar le correspondió a la variedad RA 87-3, seguida por CP 65-357 y TUCCP 77-42.The concentration of sugar and nonsugar compounds, especially those which play a part in colour formation and others which affect direct white sugar manufacturing process, was studied in the four commercial cane varieties most widely grown in Tucumán (Argentine Republic: TUCCP 77-42, LCP 85-384, CP 65-357 and RA 87-3. Trials with clean cane were conducted during the 2004-2007 harvests. Analyzed parameters were: juice extraction, Brix %, pol % in juice and cane, sucrose and sugar recovery. Inorganic nonsugar compounds, such as ash, phosphate and silica, as well as organic ones, such as fibre, starch, anthocyanin and phenolic compounds, amino nitrogen, cis and trans-aconitic acids, indicator value and colour, were studied. Results showed that LCP 85-384 variety had the best factory performance to produce direct white sugar because of its high sucrose and low

25 CFR 140.19 - Drugs.

Science.gov (United States)

2010-04-01

... 25 Indians 1 2010-04-01 2010-04-01 false Drugs. 140.19 Section 140.19 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR FINANCIAL ACTIVITIES LICENSED INDIAN TRADERS § 140.19 Drugs. Traders shall not keep for sale, or sell, give away, or use any opium, chloral, cocaine, peyote or mescal bean...

Characterization of the first core sample of neutralized current acid waste from double-shell tank 101-AZ

International Nuclear Information System (INIS)

Peterson, M.E.; Scheele, R.D.; Tingey, J.M.

1989-09-01

In FY 1989, Westinghouse Hanford Company (WHC) successfully obtained four core samples (totaling seven segments) of neutralized current acid waste (NCAW) from double-shell tanks (DSTs) 101-AZ and 102-AZ. A segment was a 19-in.-long and 1-in.-diameter cylindrical sample of waste. A core sample consisted of enough 19-in.-long segments to obtain the waste of interest. Three core samples were obtained from DST 101-AZ and one core sample from DST 102-AZ. Two DST 101-AZ core samples consisted of two segments per core, and the third core sample consisted of only one segment. The third core consisted of the solids from the bottom of the tank and was used to determine the relative abrasiveness of this NCAW. The DST 102-AZ core sample consisted of two segments. The core samples were transported to the Pacific Northwest Laboratory (PNL), where the waste was extruded from its sampler and extensively characterized. A characterization plan was followed that simulated the processing of the NCAW samples through retrieval, pretreatment and vitrification process steps. Physical, rheological, chemical and radiochemical properties were measured throughout the process steps. The characterization of the first core sample from DST 101-AZ was completed, and the results are provided in this report. The results for the other core characterizations will be reported in future reports. 3 refs., 13 figs., 10 tabs

Formation and mechanism of nanocrystalline AZ91 powders during HDDR processing

Energy Technology Data Exchange (ETDEWEB)

Liu, Yafen; Fan, Jianfeng, E-mail: fanjianfeng@tyut.edu.cn; Zhang, Hua; Zhang, Qiang; Gao, Jing; Dong, Hongbiao, E-mail: hd38@leicester.ac.uk; Xu, Bingshe

2017-03-15

Grain sizes of AZ91 alloy powders were markedly refined to about 15 nm from 100 to 160 μm by an optimized hydrogenation-disproportionation-desorption-recombination (HDDR) process. The effect of temperature, hydrogen pressure and processing time on phase and microstructure evolution of AZ91 alloy powders during HDDR process was investigated systematically by X-ray diffraction, optical microscopy, scanning electron microscopy and transmission electron microscopy, respectively. The optimal HDDR process for preparing nanocrystalline Mg alloy powders is hydriding at temperature of 350 °C under 4 MPa hydrogen pressure for 12 h and dehydriding at 350 °C for 3 h in vacuum. A modified unreacted core model was introduced to describe the mechanism of grain refinement of during HDDR process. - Highlights: • Grain size of the AZ91 alloy powders was significantly refined from 100 μm to 15 nm. • The optimal HDDR technology for nano Mg alloy powders is obtained. • A modified unreacted core model of grain refinement mechanism was proposed.

Characteristics of AZ31 Mg alloy joint using automatic TIG welding

Science.gov (United States)

Liu, Hong-tao; Zhou, Ji-xue; Zhao, Dong-qing; Liu, Yun-teng; Wu, Jian-hua; Yang, Yuan-sheng; Ma, Bai-chang; Zhuang, Hai-hua

2017-01-01

The automatic tungsten-inert gas welding (ATIGW) of AZ31 Mg alloys was performed using a six-axis robot. The evolution of the microstructure and texture of the AZ31 auto-welded joints was studied by optical microscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy, and electron backscatter diffraction. The ATIGW process resulted in coarse recrystallized grains in the heat affected zone (HAZ) and epitaxial growth of columnar grains in the fusion zone (FZ). Substantial changes of texture between the base material (BM) and the FZ were detected. The {0002} basal plane in the BM was largely parallel to the sheet rolling plane, whereas the c-axis of the crystal lattice in the FZ inclined approximately 25° with respect to the welding direction. The maximum pole density increased from 9.45 in the BM to 12.9 in the FZ. The microhardness distribution, tensile properties, and fracture features of the AZ31 auto-welded joints were also investigated.

Microstructure and corrosion behavior of electrodeposited nano-crystalline nickel coating on AZ91 Mg alloy

Energy Technology Data Exchange (ETDEWEB)

Zarebidaki, Arman, E-mail: arman.zare@iauyazd.ac.ir; Mahmoudikohani, Hassan, E-mail: hassanmahmoudi.k@gmail.com; Aboutalebi, Mohammad-Reza

2014-12-05

Highlights: • Activation, zincating, and Cu electrodeposition were used as pretreatment processes for electrodeposition of nickel coatings. • Nano-crystalline nickel coatings were successfully electrodeposited onto the AZ91 Mg alloys. • Effect of nickel electrodeposited coating on the corrosion resistance of AZ91 Mg alloy has been studied. - Abstract: In order to enhance the corrosion resistance, nickel coating was electrodeposited onto AZ91 Mg alloy. Activation, zincating, and Cu electrodeposition used as pretreatment processes for better adhesion and corrosion performance of the nickel over layer. The corrosion properties of the AZ91 Mg alloy, nickel electroplated AZ91 Mg alloy, and pure nickel was assessed via polarization and electrochemical impedance spectroscopy (EIS) methods in 3.5 wt% NaCl solution. Moreover, the structure of the coating was investigated by means of X-ray diffraction, whereas specimen’s morphology and elemental composition were analyzed using scanning electron microscope (SEM) equipped with energy dispersive spectrometer (EDS). Measurements revealed that the coating has a nano-crystalline structure with the grain size of 95 nm. Corrosion results showed superior corrosion resistance for the coated AZ91 Mg alloy as the corrosion current density decreased from 2.5 × 10{sup −4} A cm{sup −2}, for the uncoated sample, to 1.5 × 10{sup −5} A cm{sup −2}, for coated specimen and the corrosion potential increased from −1.55 V to −0.98 V (vs. Ag/AgCl) at the same condition.

“Mne govorjat, kakaja bednost’ slovarja...” Il protosamizdat del periodo staliniano alla ricerca di un’espressività

Directory of Open Access Journals (Sweden)

Massimo Maurizio

2015-07-01

Full Text Available L’estetica della letteratura afferente al circuito samizdat dopo il XX congresso del PCUS (1956 è strettamente legata alla produzione non ufficiale del periodo staliniano, a sua volta definitasi secondo una relazione antitetica alla poesia proletaria degli anni Venti. Molte delle figure di rife- rimento di questo periodo hanno attinto il proprio linguaggio e gli strumenti poetici dall'arsenale espressivo e formale del Secolo d’Argento, sebbene differenziadosene notevolmente e adattan- dolo all'estetica che essi perseguivano, intimamente alternativa a quella realsocialista. La com- plessa poetica di autori quali E. Kropivnickij, Jan Satunovskj (come anche, in un periodo succes- sivo, il “discepolo” del primo G Sapgir e molti altri hanno attinto i tratti distintivi della propria produzione dalla rielaborazione dell’arte proletaria della prima metà degli anni Venti alla luce di una visione dissacrante e grottesca della contemporaneità, che emerge in primo luogo dall'aspetto delle loro opere poetiche.

Nanopublication beyond the sciences: the PeriodO period gazetteer

Directory of Open Access Journals (Sweden)

Patrick Golden

2016-02-01

Full Text Available The information expressed in humanities datasets is inextricably tied to a wider discursive environment that is irreducible to complete formal representation. Humanities scholars must wrestle with this fact when they attempt to publish or consume structured data. The practice of “nanopublication,” which originated in the e-science domain, offers a way to maintain the connection between formal representations of humanities data and its discursive basis. In this paper we describe nanopublication, its potential applicability to the humanities, and our experience curating humanities nanopublications in the PeriodO period gazetteer.

Expression of P. falciparum var Genes Involves Exchange of the Histone Variant H2A.Z at the Promoter

Science.gov (United States)

Petter, Michaela; Lee, Chin Chin; Byrne, Timothy J.; Boysen, Katja E.; Volz, Jennifer; Ralph, Stuart A.; Cowman, Alan F.; Brown, Graham V.; Duffy, Michael F.

2011-01-01

Plasmodium falciparum employs antigenic variation to evade the human immune response by switching the expression of different variant surface antigens encoded by the var gene family. Epigenetic mechanisms including histone modifications and sub-nuclear compartmentalization contribute to transcriptional regulation in the malaria parasite, in particular to control antigenic variation. Another mechanism of epigenetic control is the exchange of canonical histones with alternative variants to generate functionally specialized chromatin domains. Here we demonstrate that the alternative histone PfH2A.Z is associated with the epigenetic regulation of var genes. In many eukaryotic organisms the histone variant H2A.Z mediates an open chromatin structure at promoters and facilitates diverse levels of regulation, including transcriptional activation. Throughout the asexual, intraerythrocytic lifecycle of P. falciparum we found that the P. falciparum ortholog of H2A.Z (PfH2A.Z) colocalizes with histone modifications that are characteristic of transcriptionally-permissive euchromatin, but not with markers of heterochromatin. Consistent with this finding, antibodies to PfH2A.Z co-precipitate the permissive modification H3K4me3. By chromatin-immunoprecipitation we show that PfH2A.Z is enriched in nucleosomes around the transcription start site (TSS) in both transcriptionally active and silent stage-specific genes. In var genes, however, PfH2A.Z is enriched at the TSS only during active transcription in ring stage parasites. Thus, in contrast to other genes, temporal var gene regulation involves histone variant exchange at promoter nucleosomes. Sir2 histone deacetylases are important for var gene silencing and their yeast ortholog antagonises H2A.Z function in subtelomeric yeast genes. In immature P. falciparum parasites lacking Sir2A or Sir2B high var transcription levels correlate with enrichment of PfH2A.Z at the TSS. As Sir2A knock out parasites mature the var genes are

Recommendation Report: EJournals/EBooks A-Z Management System

KAUST Repository

Ramli, Rindra M.

2014-01-01

This is a recommendation report for KAUST Library on the Ejournals / EBooks AZ Management systems project. It briefly described the issues faced by the ERM Team, project plan overview and the project findings as well as the recommendation(s).

76 FR 62144 - Environmental Impact Statement for Implementation of Passenger Rail Service Between Tucson, AZ...

Science.gov (United States)

2011-10-06

... impacts to the natural and built environment of those alternatives, and invite public participation in the... will provide programmatic assessment of environmental effects associated with the construction... Environmental Impact Statement for Implementation of Passenger Rail Service Between Tucson, AZ and Phoenix, AZ...

The study of a Mg-rich epoxy primer for protection of AZ91D magnesium alloy

Energy Technology Data Exchange (ETDEWEB)

Lu Xiangyu [School of Materials Science and Engineering, Beijing University of Chemical Technology, Beijing 100029 (China); Zuo Yu, E-mail: zuoy@mail.buct.edu.c [School of Materials Science and Engineering, Beijing University of Chemical Technology, Beijing 100029 (China); Zhao Xuhui; Tang Yuming; Feng Xingguo [School of Materials Science and Engineering, Beijing University of Chemical Technology, Beijing 100029 (China)

2011-01-15

Research highlights: {yields} A Mg-rich epoxy primer was prepared by adding pure magnesium particles in epoxy coating. Cross scratch testing results showed that in 3% NaCl solution the Mg-rich primer showed better protection for AZ91D magnesium alloy than the same epoxy primer without Mg addition. {yields} The open circuit potential of AZ91D alloy in NaCl solution decreased after coated with Mg-rich coating, suggesting that cathodic protection effect of the Mg-rich coating on AZ91D alloy was present. {yields} EIS studies showed that during the immersion tests of AZ91D alloy with Mg-rich coating the magnesium particles in coating dissolved with the charge-transfer resistance R{sub ct} at the magnesium particle/coating interface decreased and the double-layer capacitance Q{sub dl} increased. While the coating resistance remained stable for a long time and corrosion of the AZ91D alloy substrate was obviously delayed. - Abstract: A Mg-rich epoxy primer was prepared by adding pure magnesium particles to an epoxy coating. The coating properties were studied with electrochemical impedance spectroscopy (EIS), scanning electronic microscopy (SEM) and X-ray diffraction (XRD). The Mg-rich primer showed better protection for AZ91D magnesium alloy than the same epoxy primer without Mg addition. The open circuit potential measurements showed cathodic protection effect of the Mg-rich primer on AZ91D alloy. Cross scratch testing showed that the Mg-rich primer provided better protection for the substrate than original epoxy coating. The precipitation of Mg(OH){sub 2} in the coating also provided some degree of barrier protection.

The study of a Mg-rich epoxy primer for protection of AZ91D magnesium alloy

International Nuclear Information System (INIS)

Lu Xiangyu; Zuo Yu; Zhao Xuhui; Tang Yuming; Feng Xingguo

2011-01-01

Research highlights: → A Mg-rich epoxy primer was prepared by adding pure magnesium particles in epoxy coating. Cross scratch testing results showed that in 3% NaCl solution the Mg-rich primer showed better protection for AZ91D magnesium alloy than the same epoxy primer without Mg addition. → The open circuit potential of AZ91D alloy in NaCl solution decreased after coated with Mg-rich coating, suggesting that cathodic protection effect of the Mg-rich coating on AZ91D alloy was present. → EIS studies showed that during the immersion tests of AZ91D alloy with Mg-rich coating the magnesium particles in coating dissolved with the charge-transfer resistance R ct at the magnesium particle/coating interface decreased and the double-layer capacitance Q dl increased. While the coating resistance remained stable for a long time and corrosion of the AZ91D alloy substrate was obviously delayed. - Abstract: A Mg-rich epoxy primer was prepared by adding pure magnesium particles to an epoxy coating. The coating properties were studied with electrochemical impedance spectroscopy (EIS), scanning electronic microscopy (SEM) and X-ray diffraction (XRD). The Mg-rich primer showed better protection for AZ91D magnesium alloy than the same epoxy primer without Mg addition. The open circuit potential measurements showed cathodic protection effect of the Mg-rich primer on AZ91D alloy. Cross scratch testing showed that the Mg-rich primer provided better protection for the substrate than original epoxy coating. The precipitation of Mg(OH) 2 in the coating also provided some degree of barrier protection.

Acceptance Test Report for the 241-AZ-101 Ultrasonic Interface Level Analyzer

International Nuclear Information System (INIS)

ANDREWS, J.E.

2000-01-01

This document comprises the Acceptance Test Report for the 241-AZ-101 Ultrasonic Interface Level Analyzer. This document presents the results of Acceptance Testing of the 241-AZ-101 Ultrasonic Interface Level Analyzers (URSILLAs). Testing of the URSILLAs was performed in accordance with ATP-260-001, ''URSILLA Pre-installation Acceptance Test Procedure''. The objective of the testing was to verify that all equipment and components function in accordance with design specifications and original equipment manufacturer's specifications

Project W-211 Initial Tank Retrieval Systems (ITRS) Description of Operations for 241-AZ-102

Energy Technology Data Exchange (ETDEWEB)

BRIGGS, S.R.

2000-02-25

The primary purpose of the Initial Tank Retrieval Systems (ITRS) is to provide systems for retrieval of radioactive wastes stored in underground double-shell tanks (DSTs) for transfer to alternate storage, evaporation, pretreatment or treatment, while concurrently reducing risks associated with safety watch list and other DSTs. This Description of Operation (DOO) defines the control philosophy for the waste retrieval system for Tank 241-AZ-102 (AZ-102). This DOO provides a basis for the detailed design of the Project W-211 Retrieval Control System (RCS) for AZ-102 and also establishes test criteria for the RCS.

Project W-211 Initial Tank Retrieval Systems (ITRS) Description of Operations for 241-AZ-102

International Nuclear Information System (INIS)

BRIGGS, S.R.

2000-01-01

The primary purpose of the Initial Tank Retrieval Systems (ITRS) is to provide systems for retrieval of radioactive wastes stored in underground double-shell tanks (DSTs) for transfer to alternate storage, evaporation, pretreatment or treatment, while concurrently reducing risks associated with safety watch list and other DSTs. This Description of Operation (DOO) defines the control philosophy for the waste retrieval system for Tank 241-AZ-102 (AZ-102). This DOO provides a basis for the detailed design of the Project W-211 Retrieval Control System (RCS) for AZ-102 and also establishes test criteria for the RCS

75 FR 81190 - Television Broadcasting Services; Yuma, AZ

Science.gov (United States)

2010-12-27

... FEDERAL COMMUNICATIONS COMMISSION 47 CFR Part 73 [DA 10-2365; MB Docket No. 02-151; RM-10453] Television Broadcasting Services; Yuma, AZ AGENCY: Federal Communications Commission. ACTION: Dismissal. SUMMARY: The Commission dismisses the petition for rulemaking filed by Arizona Western College, requesting...

Tipos de Tiempo en el periodo de Semana Santa Vallisoletana.

OpenAIRE

Miranda Martín, Javier

2017-01-01

El propósito del proyecto es el análisis y la caracterización de ciertos tipos de tiempo a partir de los datos observados de la Base de Datos Climatológica del Observatorio de Valladolid. Los datos analizados corresponden a los ocho días de Semana Santa de un periodo de 37 años que comprenden entre los años 1981 y 2017. Grado en Geografía y Ordenación del Territorio

Cesium Removal From Tanks 241-AN-103 and 241-SX-105 and 241-AZ-101 and 241-AZ-102 Composite For Testing In Bench Scale Steam Reformer

International Nuclear Information System (INIS)

Duncan, J.B.; Huber, H.J.

2011-01-01

This report documents the preparation of three actual Hanford tank waste samples for shipment to the Savannah River National Laboratory (SRNL). Two of the samples were dissolved saltcakes from tank 241-AN-103 (hereafter AN-103) and tank 241-SX-105 (hereafter SX-105); one sample was a supernate composite from tanks 241-AZ-101 and 241-AZ-102 (hereafter AZ-101/102). The preparation of the samples was executed following the test plans LAB-PLAN-10-00006, Test Plan for the Preparation of Samples from Hanford Tanks 241-SX-105, 241-AN-103, 241-AN-107, and LAB-PLN-l0-00014, Test Plan for the Preparation of a Composite Sample from Hanford Tanks 241-AZ-101 and 241-AZ-102 for Steam Reformer Testing at the Savannah River National Laboratory. All procedural steps were recorded in laboratory notebook HNF-N-274 3. Sample breakdown diagrams for AN-103 and SX-105 are presented in Appendix A. The tank samples were prepared in support of a series of treatability studies of the Fluidized Bed Steam Reforming (FBSR) process using a Bench-Scale Reformer (BSR) at SRNL. Tests with simulants have shown that the FBSR mineralized waste form is comparable to low-activity waste glass with respect to environmental durability (WSRC-STI-2008-00268, Mineralization of Radioactive Wastes by Fluidized Bed Steam Reforming (FBSR): Comparisons to Vitreous Waste Forms and Pertinent Durability Testing). However, a rigorous assessment requires long-term performance data from FBSR product formed from actual Hanford tank waste. Washington River Protection Solutions, LLC (WRPS) has initiated a Waste Form Qualification Program (WP-5.2.1-2010-001, Fluidized Bed Steam Reformer Low-level Waste Form Qualification) to gather the data required to demonstrate that an adequate FBSR mineralized waste form can be produced. The documentation of the selection process of the three tank samples has been separately reported in RPP-48824, Sample Selection Process for Bench-Scale Steam Reforming Treatability Studies Using

Acceptance Test Report for the 241-AZ-101 Ultrasonic Interface Level Analyzer

Energy Technology Data Exchange (ETDEWEB)

ANDREWS, J.E.

2000-01-27

This document comprises the Acceptance Test Report for the 241-AZ-101 Ultrasonic Interface Level Analyzer. This document presents the results of Acceptance Testing of the 241-AZ-101 Ultrasonic Interface Level Analyzers (URSILLAs). Testing of the URSILLAs was performed in accordance with ATP-260-001, ''URSILLA Pre-installation Acceptance Test Procedure''. The objective of the testing was to verify that all equipment and components function in accordance with design specifications and original equipment manufacturer's specifications.

Development of mechanical properties in a CaO added AZ31 magnesium alloy processed by equal-channel angular pressing

Energy Technology Data Exchange (ETDEWEB)

Bae, Seong-Hwan [Division of Materials Science and Engineering, Hanyang University, Seoul 133-791 (Korea, Republic of); Metal Forming Technology R& D Group, Korea Institute of Industrial Technology, Incheon 406-840 (Korea, Republic of); Jung, Ki Ho; Shin, Young-Chul; Yoon, Duk Jae [Metal Forming Technology R& D Group, Korea Institute of Industrial Technology, Incheon 406-840 (Korea, Republic of); Kawasaki, Megumi, E-mail: megumi@hanyang.ac.kr [Division of Materials Science and Engineering, Hanyang University, Seoul 133-791 (Korea, Republic of); Departments of Aerospace & Mechanical Engineering and Materials Science, University of Southern California, Los Angeles, CA 90089-1453 (United States)

2016-02-15

Processing through the application of equal-channel angular pressing (ECAP) is recognized as one of the attractive severe plastic deformation techniques where the processed bulk metals generally achieve ultrafine-grained microstructure leading to improved physical characteristics and mechanical properties. Magnesium has received much attention to date for its lightweight, high strength and excellent elasticity. Mg alloys with addition of CaO is reported to provide the successful casting procedure without usage of greenhouse gas, SF{sub 6}, whereas it is generally used for preventing the oxidation of Mg during casting. In the present investigation, a CaO added AZ31 (AZ31-CaO) magnesium alloy was processed by ECAP at elevated temepratures with a few steps of reduction which result in significant grain refinement to ~ 1.5 μm after 6 passes. Compression testing at room temperature demonstrated the AZ31-CaO alloy after ECAP showed enhanced yield strength more than the as-processed commercial AZ31 alloy while both alloys maintained ductility in spite of significant reduction in grain size. The improved strength in the AZ31-CaO alloy was attributed to the formation of fine Al{sub 2}Ca precipitates which experience breaking-up through ECAP and accelerate the microstructural refinement. Moreover, the preservation of ductility was attributed to the enhancement of strain hardening capability in the AZ31 alloy at room temperature. This study discusses the feasibility of using ECAP to improve both strength and ductility on magnesium alloys by applying the diagram describing the paradox of strength and ductility. - Highlights: • AZ31 and AZ31-CaO magnesium alloys were processed by ECAP up to 6 passes. • AZ31-CaO alloy after ECAP showed improved yield strength without losing ductility. • CaO in AZ31 forms fine Al{sub 2}Ca accelerating microstructural refinement during ECAP. • Feasibility of using ECAP was shown to improve both strength and ductility in Mg.

Development of mechanical properties in a CaO added AZ31 magnesium alloy processed by equal-channel angular pressing

International Nuclear Information System (INIS)

Bae, Seong-Hwan; Jung, Ki Ho; Shin, Young-Chul; Yoon, Duk Jae; Kawasaki, Megumi

2016-01-01

Processing through the application of equal-channel angular pressing (ECAP) is recognized as one of the attractive severe plastic deformation techniques where the processed bulk metals generally achieve ultrafine-grained microstructure leading to improved physical characteristics and mechanical properties. Magnesium has received much attention to date for its lightweight, high strength and excellent elasticity. Mg alloys with addition of CaO is reported to provide the successful casting procedure without usage of greenhouse gas, SF 6 , whereas it is generally used for preventing the oxidation of Mg during casting. In the present investigation, a CaO added AZ31 (AZ31-CaO) magnesium alloy was processed by ECAP at elevated temepratures with a few steps of reduction which result in significant grain refinement to ~ 1.5 μm after 6 passes. Compression testing at room temperature demonstrated the AZ31-CaO alloy after ECAP showed enhanced yield strength more than the as-processed commercial AZ31 alloy while both alloys maintained ductility in spite of significant reduction in grain size. The improved strength in the AZ31-CaO alloy was attributed to the formation of fine Al 2 Ca precipitates which experience breaking-up through ECAP and accelerate the microstructural refinement. Moreover, the preservation of ductility was attributed to the enhancement of strain hardening capability in the AZ31 alloy at room temperature. This study discusses the feasibility of using ECAP to improve both strength and ductility on magnesium alloys by applying the diagram describing the paradox of strength and ductility. - Highlights: • AZ31 and AZ31-CaO magnesium alloys were processed by ECAP up to 6 passes. • AZ31-CaO alloy after ECAP showed improved yield strength without losing ductility. • CaO in AZ31 forms fine Al 2 Ca accelerating microstructural refinement during ECAP. • Feasibility of using ECAP was shown to improve both strength and ductility in Mg.

23 CFR 140.505 - Reimbursable costs.

Science.gov (United States)

2010-04-01

... 23 Highways 1 2010-04-01 2010-04-01 false Reimbursable costs. 140.505 Section 140.505 Highways... Administrative Settlement Costs-Contract Claims § 140.505 Reimbursable costs. (a) Federal funds may participate in administrative settlement costs which are: (1) Incurred after notice of claim, (2) Properly...

23 CFR 140.612 - Cash management.

Science.gov (United States)

2010-04-01

... 23 Highways 1 2010-04-01 2010-04-01 false Cash management. 140.612 Section 140.612 Highways FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION PAYMENT PROCEDURES REIMBURSEMENT Reimbursement for Bond Issue Projects § 140.612 Cash management. By July 1 of each year the SHA will provide...

7 CFR 4280.140 - Financial statements.

Science.gov (United States)

2010-01-01

... 7 Agriculture 15 2010-01-01 2010-01-01 false Financial statements. 4280.140 Section 4280.140... Efficiency Improvements Program Section B. Guaranteed Loans § 4280.140 Financial statements. (a) The... financial statements, at its sole discretion when the Agency is concerned about the applicant's credit risk. ...

32 CFR 644.140 - Physical protection.

Science.gov (United States)

2010-07-01

... 32 National Defense 4 2010-07-01 2010-07-01 true Physical protection. 644.140 Section 644.140... ESTATE HANDBOOK Acquisition Acquisition by Leasing § 644.140 Physical protection. It is essential that the Division or District Engineer make provision for the physical protection for all facilities under...

An exponential material model for prediction of the flow curves of several AZ series magnesium alloys in tension and compression

International Nuclear Information System (INIS)

Fereshteh-Saniee, F.; Barati, F.; Badnava, H.; Fallah Nejad, Kh.

2012-01-01

Highlights: ► The exponential model can represent flow behaviors of AZ series Mg alloys very well. ► Strain rate sensitivities of AZ series Mg alloys in compression are nearly the same. ► Effect of zinc element on tensile activation energy is higher than on compressive one. ► Activation energies of AZ80 and AZ81 in tension were greater than in compression. ► Tensile and compressive rate sensitivities of AZ80 are not close to each other. -- Abstract: This paper is concerned with flow behaviors of several magnesium alloys, such as AZ31, AZ80 and AZ81, in tension and compression. The experiments were performed at elevated temperatures and for various strain rates. In order to eliminate the effect of inhomogeneous deformation in tensile and compression tests, the Bridgeman’s and numerical correction factors were respectively employed. A two-section exponential mathematical model was also utilized for prediction of flow stresses of different magnesium alloys in tension and compression. Moreover, based on the compressive flow model proposed, the peak stress and the relevant true strain could be estimated. The true stress and strain of the necking point can also be predicted using the corresponding relations. It was found that the flow behaviors estimated by the exponential flow model were encouragingly in very good agreement with experimental findings.

Diffusion Bonding and Post-Weld Heat Treatment of Extruded AZ91 Magnesium Alloys

Directory of Open Access Journals (Sweden)

Fei LIN

2015-11-01

Full Text Available The grain size of as-extruded AZ91 magnesium alloys was refined to 12.31 μm from 21.41 μm by recrystallization annealing. The vacuum diffusion welding of as-annealed AZ91 magnesium alloys was researched. The results showed that the maximum shear strength of joints reached 64.70 MPa in the situation of 10 MPa bonding pressure, 18 Pa vacuum degree, 470 °C bonding temperature and 90 min bonding time; both bonding temperature and time are the main influence factors on as-extruded AZ91 magnesium alloys diffusion welding. Then the diffusion welded specimens were annealed, and the shear strength of joints was further improved to 76.93 MPa.DOI: http://dx.doi.org/10.5755/j01.ms.21.4.9699

7 CFR 15e.140 - Employment.

Science.gov (United States)

2010-01-01

... 7 Agriculture 1 2010-01-01 2010-01-01 false Employment. 15e.140 Section 15e.140 Agriculture Office... OR ACTIVITIES CONDUCTED BY THE UNITED STATES DEPARTMENT OF AGRICULTURE § 15e.140 Employment. No... employment under any program or activity conducted by the agency. The definitions, requirements, and...

12 CFR 313.140 - Future benefits.

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2010-01-01

... 12 Banks and Banking 4 2010-01-01 2010-01-01 false Future benefits. 313.140 Section 313.140 Banks... CORPORATE DEBT COLLECTION Civil Service Retirement and Disability Fund Offset § 313.140 Future benefits. Unless otherwise prohibited by law, the FDIC may request that a debtor's anticipated or future benefit...

20 CFR 401.140 - General principles.

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2010-04-01

... 20 Employees' Benefits 2 2010-04-01 2010-04-01 false General principles. 401.140 Section 401.140... INFORMATION Disclosure of Official Records and Information § 401.140 General principles. When no law... follow FOIA principles to resolve that question. We do this to insure uniform treatment in all situations...

Insomnio, latencia al sueño y cantidad de sueño en estudiantes universitarios chilenos durante el periodo de clases y exámenes

OpenAIRE

Samuel Durán Agüero; Giovanni Rosales Soto; Cristóbal Moya Cantillana; Paula García Milla

2017-01-01

Objetivo:Determinar los factores asociados a la cantidad de horas de sueño, somnolenciadiurna e insomnio antes y durante un periodo de clases y exámenes.Material y métodos:Se evaluó a 384 alumnos de ambos sexos (74,1% mujeres), quienesreportaron su peso y estatura. A cada estudiante se le aplicó el Cuestionario de Insomnio y laEscala De Somnolencia de Epworth en el periodo de clases y periodo de exámenes.Resultados:Al comparar la somnolencia diurna, insomnio, latencia al sueño y cantidad deho...

The effects of alloying elements on microstructures and mechanical properties of tungsten inert gas welded AZ80 magnesium alloys joint

Science.gov (United States)

Li, Hui; Zhang, Jiansheng; Ding, Rongrong

2017-11-01

The effects of alloying elements on the macrostructures, microstructures and tensile strength of AZ80 Mg alloy weldments were studied in the present study. The results indicate that with the decrease of Al element content of filler wire, the welding defects of seam are gradually eliminated and the β-Mg17Al12 phases at α-Mg boundaries are refined and become discontinuous, which are beneficial to the improvement of tensile strength. With AZ31 Mg alloy filler wire, the maximum tensile strength of AZ80 weldment is 220 MPa and fracture occurs at the welding seam of joint. It is experimentally proved that robust AZ80 Mg alloy joints can be obtained by tungsten inert gas (TIG) welding process with AZ31 Mg alloy filler wire. However, further study is required to improve the microstructures and reduce welding defects of joint in order to further improve the joining strength of AZ80 Mg alloy joint.

23 CFR 140.807 - Reimbursable costs.

Science.gov (United States)

2010-04-01

... 23 Highways 1 2010-04-01 2010-04-01 false Reimbursable costs. 140.807 Section 140.807 Highways... Highway Agency Audit Expense § 140.807 Reimbursable costs. (a) Federal funds may be used to reimburse an SHA for the following types of project related audit costs: (1) Salaries, wages, and related costs...

40 CFR 1033.140 - Rated power.

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2010-07-01

... 40 Protection of Environment 32 2010-07-01 2010-07-01 false Rated power. 1033.140 Section 1033.140... EMISSIONS FROM LOCOMOTIVES Emission Standards and Related Requirements § 1033.140 Rated power. This section describes how to determine the rated power of a locomotive for the purposes of this part. (a) A locomotive...

7 CFR 905.140 - Gift packages.

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2010-01-01

... 7 Agriculture 8 2010-01-01 2010-01-01 false Gift packages. 905.140 Section 905.140 Agriculture... TANGELOS GROWN IN FLORIDA Rules and Regulations Non-Regulated Fruit § 905.140 Gift packages. Any handler..., ship any varieties for the following purpose and types of shipment: (a) To any person gift packages...

23 CFR 140.906 - Labor costs.

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2010-04-01

... 23 Highways 1 2010-04-01 2010-04-01 false Labor costs. 140.906 Section 140.906 Highways FEDERAL... Railroad Work § 140.906 Labor costs. (a) General. (1) Salaries and wages, at actual or average rates, and... reimbursable when supported by adequate records. This shall include labor costs associated with preliminary...

23 CFR 140.606 - Project agreements.

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2010-04-01

... Reimbursement for Bond Issue Projects § 140.606 Project agreements. Project Agreements, Form PR-2, shall be... 23 Highways 1 2010-04-01 2010-04-01 false Project agreements. 140.606 Section 140.606 Highways... projects. 1 The text of FHWA Form PR-2 is found in 23 CFR part 630, subpart C, appendix A. ...

Effect of Pr addition on microstructure and mechanical properties of AZ61 magnesium alloy

Directory of Open Access Journals (Sweden)

You Zhiyong

2014-03-01

Full Text Available To improve the strength, hardness and heat resistance of Mg-6Al-1Zn (AZ61 alloy, the effects of Pr addition on the as-cast microstructure and mechanical properties of AZ61 alloy were investigated at room and elevated temperatures by means of Brinell hardness measurement, optical microscope (OM, scanning electron microscope (SEM, energy dispersive spectroscopy (EDS, X-ray diffractometer (XRD and DNS100 electronic universal testing machine. The results show that the microstructures of Pr-containing AZ61 alloys were refined, with primary β-Mg17Al12 phase distributed homogeneously. When the addition of Pr is up to 1.2wt.%, the β phase becomes finer, and new needle-like or short-rod shaped Al11Pr3 phase and blocky AlPr phase appear. As a result, optimal tensile properties are obtained. However, greater than 1.2wt.% Pr addition leads to poorer mechanical properties due to the aggregation of the needle-like phase and large size of grains. The present research findings provide a new way for strengthening of magnesium alloys at room and elevated temperatures, and a method of producing thermally-stable AZ61 magnesium alloy.

Study on fused/cast AZS refractories for deployment in vitrification of radioactive waste effluents

Science.gov (United States)

Sengupta, Pranesh; Mishra, R. K.; Soudamini, N.; Sen, D.; Mazumder, S.; Kaushik, C. P.; Ajithkumar, T. G.; Banerjee, K.

2015-12-01

'Fused/cast Al2O3-ZrO2-SiO2 (FC-AZS)' is being considered as 'glass contact refractory' within ceramic melters, to be used for nuclear waste immobilization. Microstructural analyses reveal random distributions of baddeleyite (ZrO2) within aluminosilicate (Al2SiO5) matrix. 27Al and 29Si NMR data suggest that within aluminosilicate matrix Al occurs in both 4- and 6-fold co-ordinations whereas Si prefers a 4-fold environment. Polydispersity of pores has been studied with small-angle neutron scattering (SANS) technique. Corrosion rates of FC-AZS within 6 M HNO3, simulated wastes (500 h exposure), and borosilicate melt (975 °C, 800 h exposure) are found to be 0.38 × 103 μmy-1, 0.13 × 103 μmy-1 and 4.75 × 103 μmy-1 respectively. A comparison of chemical interaction data clearly suggests that FC-AZS exhibits better chemical durability than AZC refractory (Al2O3-ZrO2-Cr2O3, also used for similar purpose). Thermal cycling studies indicate that FC-AZS retains structural integrity (including compressive strength and density) even up to 20 cycles.

21 CFR 168.140 - Maple sirup.

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2010-04-01

... 21 Food and Drugs 2 2010-04-01 2010-04-01 false Maple sirup. 168.140 Section 168.140 Food and... § 168.140 Maple sirup. (a) Maple sirup is the liquid food derived by concentration and heat treatment of the sap of the maple tree (Acer) or by solution in water of maple sugar (mapel concrete) made from...

Blocking spinal CCR2 with AZ889 reversed hyperalgesia in a model of neuropathic pain

Directory of Open Access Journals (Sweden)

Vaillancourt François

2010-12-01

Full Text Available Abstract Background The CCR2/CCL2 system has been identified as a regulator in the pathogenesis of neuropathy-induced pain. However, CCR2 target validation in analgesia and the mechanism underlying antinociception produced by CCR2 antagonists remains poorly understood. In this study, in vitro and in vivo pharmacological approaches using a novel CCR2 antagonist, AZ889, strengthened the hypothesis of a CCR2 contribution to neuropathic pain and provided confidence over the possibilities to treat neuropathic pain with CCR2 antagonists. Results We provided evidence that dorsal root ganglia (DRG cells harvested from CCI animals responded to stimulation by CCL2 with a concentration-dependent calcium rise involving PLC-dependent internal stores. This response was associated with an increase in evoked neuronal action potentials suggesting these cells were sensitive to CCR2 signalling. Importantly, treatment with AZ889 abolished CCL2-evoked excitation confirming that this activity is CCR2-mediated. Neuronal and non-neuronal cells in the spinal cord were also excited by CCL2 applications indicating an important role of spinal CCR2 in neuropathic pain. We next showed that in vivo spinal intrathecal injection of AZ889 produced dose-dependent analgesia in CCI rats. Additionally, application of AZ889 to the exposed spinal cord inhibited evoked neuronal activity and confirmed that CCR2-mediated analgesia involved predominantly the spinal cord. Furthermore, AZ889 abolished NMDA-dependent wind-up of spinal withdrawal reflex pathway in neuropathic animals giving insight into the spinal mechanism underlying the analgesic properties of AZ889. Conclusions Overall, this study strengthens the important role of CCR2 in neuropathic pain and highlights feasibility that interfering on this mechanism at the spinal level with a selective antagonist can provide new analgesia opportunities.

Effect of Rare Earth on Corrosion Products and Impedance Behavior of AZ91 Magnesium Alloy Under Dry-wet Cycles

Directory of Open Access Journals (Sweden)

ZHAO Xi

2017-04-01

Full Text Available The effect of mischmetal of lanthanum and cerium on the composition and structure of the corrosion products on the surface of AZ91 Mg alloy in deicing salt solution under dry-wet cycles was investigated by scanning electron microscopy (SEM, X-ray diffraction (XRD and energy dispersive spectrometer (EDS. The results show that the corrosion products of AZ91 Mg alloy without mischmetal addition (La,Ce are mainly composed of Mg(OH2, MgO, CaCO3 and Mg6Al2CO3(OH16·4H2O; and (La,CeAlO3 can be found in the products of AZ91 with mischmetal addition, meanwhile dense layer occurs in the corrosion products. Electrochemical impedance spectroscopy (EIS measurements show that the charge transfer resistance of AZ91 alloy with mischmetal addition tested in the same dry-wet cycles is much higher than that of AZ91 alloy, the addition of mischmetal helps to reduce the dispersing effect of impedance spectroscopy, indicating that the corrosion resistance of AZ91 Mg alloy and the stability of corrosion product films can be improved by mischmetal of La and Ce.

Effectiveness of Ti-micro alloying in relation to cooling rate on corrosion of AZ91 Mg alloy

International Nuclear Information System (INIS)

Candan, S.; Celik, M.; Candan, E.

2016-01-01

In this study, micro Ti-alloyed AZ91 Mg alloys (AZ91 + 0.5wt.%Ti) have been investigated in order to clarify effectiveness of micro alloying and/or cooling rate on their corrosion properties. Molten alloys were solidified under various cooling rates by using four stage step mold. The microstructural investigations were carried out by using scanning electron microscopy (SEM). Corrosion behaviors of the alloys were evaluated by means of immersion and electrochemical polarization tests in 3.5% NaCl solution. Results showed that the Mg 17 Al 12 (β) intermetallic phase in the microstructure of AZ91 Mg alloy formed as a net-like structure. The Ti addition has reduced the distribution and continuity of β intermetallic phase and its morphology has emerged as fully divorced eutectic. Compared to AZ91 alloy, the effect of the cooling rate in Ti-added alloy on the grain size was less pronounced. When AZ91 and its Ti-added alloys were compared under the same cooling conditions, the Ti addition showed notably high corrosion resistance. Electrochemical test results showed that while I corr values of AZ91 decrease with the increase in the cooling rate, the effect of the cooling rate on I corr values was much lower in the Ti-added alloy. The corrosion resistance of AZ91 Mg alloy was sensitive towards the cooling rates while Ti-added alloy was not affected much from the cooling conditions. - Highlights: • Effect the cooling rate on grain size was less pronounced in the Ti-added alloy. • The morphology of the β phase transformed into fully divorced eutectics. • Ti addition exhibited significantly higher corrosion resistance. • Ti micro alloying is more effective than faster cooling of the alloy on corrosion.

TIP48/Reptin and H2A.Z requirement for initiating chromatin remodeling in estrogen-activated transcription.

Directory of Open Access Journals (Sweden)

Mathieu Dalvai

2013-04-01

Full Text Available Histone variants, including histone H2A.Z, are incorporated into specific genomic sites and participate in transcription regulation. The role of H2A.Z at these sites remains poorly characterized. Our study investigates changes in the chromatin environment at the Cyclin D1 gene (CCND1 during transcriptional initiation in response to estradiol in estrogen receptor positive mammary tumour cells. We show that H2A.Z is present at the transcription start-site and downstream enhancer sequences of CCND1 when the gene is poorly transcribed. Stimulation of CCND1 expression required release of H2A.Z concomitantly from both these DNA elements. The AAA+ family members TIP48/reptin and the histone variant H2A.Z are required to remodel the chromatin environment at CCND1 as a prerequisite for binding of the estrogen receptor (ERα in the presence of hormone. TIP48 promotes acetylation and exchange of H2A.Z, which triggers a dissociation of the CCND1 3' enhancer from the promoter, thereby releasing a repressive intragenic loop. This release then enables the estrogen receptor to bind to the CCND1 promoter. Our findings provide new insight into the priming of chromatin required for transcription factor access to their target sequence. Dynamic release of gene loops could be a rapid means to remodel chromatin and to stimulate transcription in response to hormones.

A biodegradable AZ91 magnesium alloy coated with a thin nanostructured hydroxyapatite for improving the corrosion resistance

Energy Technology Data Exchange (ETDEWEB)

Mukhametkaliyev, T.M.; Surmeneva, M.A. [National Research Tomsk Polytechnic University, 634050, Lenin Avenue 43, Tomsk (Russian Federation); Vladescu, A. [National Research Tomsk Polytechnic University, 634050, Lenin Avenue 43, Tomsk (Russian Federation); National Institute for Optoelectronics, 409 Atomistilor St., RO77125 Magurele (Romania); Cotrut, C.M. [National Research Tomsk Polytechnic University, 634050, Lenin Avenue 43, Tomsk (Russian Federation); Politehnica University of Bucharest, 313 Spl. Independentei, Bucharest (Romania); Braic, M.; Dinu, M. [National Institute for Optoelectronics, 409 Atomistilor St., RO77125 Magurele (Romania); Vranceanu, M.D. [Politehnica University of Bucharest, 313 Spl. Independentei, Bucharest (Romania); Pana, I. [National Institute for Optoelectronics, 409 Atomistilor St., RO77125 Magurele (Romania); Faculty of Physics, Bucharest University, 405 Atomistilor St., RO77125 Magurele (Romania); Mueller, M. [Fraunhofer Institute for Interfacial Engineering and Biotechnology IGB, 70569 Stuttgart (Germany); Surmenev, R.A., E-mail: rsurmenev@gmail.com [National Research Tomsk Polytechnic University, 634050, Lenin Avenue 43, Tomsk (Russian Federation)

2017-06-01

The main aim of this study was to investigate the properties of an AZ91 alloy coated with nanostructured hydroxyapatite (HA) prepared by radio frequency (RF) magnetron sputtering. The bioactivity and biomineralization of the AZ91 magnesium alloy coated with HA were investigated in simulated body fluid (SBF) via an in vitro test. Scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, and X-ray diffraction (XRD) analyses were performed. The samples were immersed in SBF to study the ability of the surface to promote the formation of an apatite layer as well as corrosion resistance and mass change of the HA-coated AZ91 alloy. Electrochemical tests were performed to estimate the corrosion behaviour of HA-coated and uncoated samples. The results revealed the capability of the HA coating to significantly improve the corrosion resistance of the uncoated AZ91 alloy. - Highlights: • The nanostructured HA layer allows to control the degradation rate of the AZ91 alloy. • The HA coating significantly reduces the corrosion current density. • The HA coating significantly improves the polarization resistance in vitro. • The RF magnetron deposited HA coating promotes calcium-phosphate precipitation in SBF.

A biodegradable AZ91 magnesium alloy coated with a thin nanostructured hydroxyapatite for improving the corrosion resistance

International Nuclear Information System (INIS)

Mukhametkaliyev, T.M.; Surmeneva, M.A.; Vladescu, A.; Cotrut, C.M.; Braic, M.; Dinu, M.; Vranceanu, M.D.; Pana, I.; Mueller, M.; Surmenev, R.A.

2017-01-01

The main aim of this study was to investigate the properties of an AZ91 alloy coated with nanostructured hydroxyapatite (HA) prepared by radio frequency (RF) magnetron sputtering. The bioactivity and biomineralization of the AZ91 magnesium alloy coated with HA were investigated in simulated body fluid (SBF) via an in vitro test. Scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, and X-ray diffraction (XRD) analyses were performed. The samples were immersed in SBF to study the ability of the surface to promote the formation of an apatite layer as well as corrosion resistance and mass change of the HA-coated AZ91 alloy. Electrochemical tests were performed to estimate the corrosion behaviour of HA-coated and uncoated samples. The results revealed the capability of the HA coating to significantly improve the corrosion resistance of the uncoated AZ91 alloy. - Highlights: • The nanostructured HA layer allows to control the degradation rate of the AZ91 alloy. • The HA coating significantly reduces the corrosion current density. • The HA coating significantly improves the polarization resistance in vitro. • The RF magnetron deposited HA coating promotes calcium-phosphate precipitation in SBF.

Influencia de compuestos azúcares y no azúcares en la calidad industrial de caña de azúcar en Tucumán, R. Argentina: caña verde y quemada (Parte 2 Effect of sugar and non sugar compounds on sugar cane industrial quality in Tucumán (Argentina

Directory of Open Access Journals (Sweden)

B. Silvia Zossi

2011-06-01

Full Text Available A partir de 1997 en Tucumán, R. Argentina, entre el 65% y el 85% de la caña destinada a la producción de azúcar se cosecha en verde o quemada, mediante el sistema de cosecha integral. El resto del cultivo se cosecha en forma semimecánica, con un predominio del uso de la quema, del corte manual y carguío mecánico. La quema de caña, antes o después de ser cosechada, se realiza para remover las hojas adheridas a sus tallos, minimizando así el ingreso de no azúcares a la fábrica. Desde el año 2005, debido a disposiciones legislativas, la cosecha de caña en verde fue aumentando gradualmente, lo que incrementó considerablemente la concentración de compuestos no azúcares en el proceso de elaboración de azúcar. Por ello se decidió evaluar los principales componentes azúcares y no azúcares, especialmente los formadores de color, y su influencia en el proceso fabril de las cuatro variedades comerciales más difundidas en la provincia: TUCCP 77-42, LCP 85-384, CP 65-357 y RA 87-3, cosechadas de tres maneras diferentes: tallo molible limpio, despuntado y sin hojas; caña quemada para eliminar las hojas y despuntada y caña cosechada en verde, con un 15% de "trash" (hojas y despunte aproximadamente. En este trabajo se presentan los datos obtenidos con cosecha en verde y quemada. Los resultados mostraron que la variedad LCP 85-384 es la que presentó el mejor comportamiento para la producción de azúcar, por su mayor contenido de este sacárido y menores tenores de fibra y compuestos no azúcares, independientemente del tipo de cosecha. En las cuatro variedades estudiadas, disminuyeron la extracción de jugo y la cantidad de azúcar recuperable en fábrica y se incrementaron los contenidos de compuestos no azúcares, principalmente almidón y cenizas, cuando se trabajó con caña cosechada en verde.Since 1997 in Tucumán, Argentina, between 65% and 85% of cane for sugar production has been harvested mechanically, either green or burnt

Análisis del perfil de azúcares en la autentificación de zumos de frutas

OpenAIRE

Úbeda Gallego, Ana

2013-01-01

El objetivo general ha sido estudiar el perfil de azúcares por HPAEC-PAD para la autentificación de zumos de frutas de naranja, manzana y piña. Este objetivo general se ha dividido en los siguientes objetivos parciales: 1. Optimizar el método de análisis de azúcares por HPAEC-PAD. Para ello se han ensayado distintas concentraciones de NaOH en la fase móvil y distinta velocidad de flujo. Se han analizando muestras de azúcares, zumos concentrados y zumos comerciales. 2. Determinar el p...

29 CFR 1615.140 - Employment.

Science.gov (United States)

2010-07-01

... 29 Labor 4 2010-07-01 2010-07-01 false Employment. 1615.140 Section 1615.140 Labor Regulations Relating to Labor (Continued) EQUAL EMPLOYMENT OPPORTUNITY COMMISSION ENFORCEMENT OF NONDISCRIMINATION ON THE BASIS OF DISABILITY IN PROGRAMS OR ACTIVITIES CONDUCTED BY THE EQUAL EMPLOYMENT OPPORTUNITY...

EnviroAtlas - Phoenix, AZ - BenMAP Results by Block Group

Data.gov (United States)

U.S. Environmental Protection Agency — This EnviroAtlas dataset demonstrates the effect of changes in pollution concentration on local populations in 2,434 block groups in Phoenix, AZ. The US EPA's...

42 CFR 410.140 - Definitions.

Science.gov (United States)

2010-10-01

... 42 Public Health 2 2010-10-01 2010-10-01 false Definitions. 410.140 Section 410.140 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES MEDICARE PROGRAM... condition of abnormal glucose metabolism diagnosed using the following criteria: A fasting blood sugar...

7 CFR 948.140 - Application.

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2010-01-01

... 7 Agriculture 8 2010-01-01 2010-01-01 false Application. 948.140 Section 948.140 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... packing facilities are located in an area where inspection is not readily available or the actual cost for...

21 CFR 820.140 - Handling.

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2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Handling. 820.140 Section 820.140 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES... manufacturer shall establish and maintain procedures to ensure that mixups, damage, deterioration...

22 CFR 1600.140 - Employment.

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2010-04-01

... 22 Foreign Relations 2 2010-04-01 2010-04-01 true Employment. 1600.140 Section 1600.140 Foreign... Employment. No qualified handicapped person shall, on the basis of handicap, be subjected to discrimination in employment under any program or activity conducted by the agency. The definitions, requirements...

45 CFR 1181.140 - Employment.

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2010-10-01

... 45 Public Welfare 3 2010-10-01 2010-10-01 false Employment. 1181.140 Section 1181.140 Public... Employment. No qualified handicapped person shall, on the basis of handicap, be subjected to discrimination in employment under any program or activity conducted by the agency. The definitions, requirements...

16 CFR 1034.140 - Employment.

Science.gov (United States)

2010-01-01

... 16 Commercial Practices 2 2010-01-01 2010-01-01 false Employment. 1034.140 Section 1034.140... Employment. No qualified handicapped person shall, on the basis of handicap, be subjected to discrimination in employment under any program or activity conducted by the agency. The definitions, requirements...

Tank 241-AZ-102 Privatization Push Mode Core Sampling and Analysis Plan; FINAL

International Nuclear Information System (INIS)

TEMPLETON, A.M.

1999-01-01

This sampling and analysis plan (SAP) identifies characterization objectives pertaining to sample collection, laboratory analytical evaluation, and reporting requirements for samples obtained from tank 241-AZ-102. The purpose of this sampling event is to obtain information about the characteristics of the contents of 241-AZ-102. Push mode core samples will be obtained from risers 15C and 24A to provide sufficient material for the chemical analyses and tests required to satisfy these data quality objectives. The 222-S Laboratory will extrude core samples, composite the liquids and solids, perform chemical analyses, and provide subsamples to the Process Chemistry Laboratory. The Process Chemistry Laboratory will prepare test plans and perform process tests to evaluate the behavior of the 241-AZ-102 waste undergoing the retrieval and treatment scenarios defined in the applicable DQOs. Requirements for analyses of samples originating in the process tests will be documented in the corresponding test plan

Influence of inorganic acid pickling on the corrosion resistance of magnesium alloy AZ31 sheet

DEFF Research Database (Denmark)

Nwaogu, Ugochukwu Chibuzoh; Blawert, C.; Scharnagl, N.

2009-01-01

Surface contaminants as a result of thermo-mechanical processing of magnesium alloys, e.g. sheet rolling, can have a negative effect on the corrosion resistance of magnesium alloys. Especially contaminants such as Fe, Ni and Cu, left on the surface of magnesium alloys result in the formation...... of micro-galvanic couples and can therefore increase corrosion attack on these alloys. Due to this influence they should be removed to obtain good corrosion resistance. In this study, the effect of inorganic acid pickling on the corrosion behaviour of a commercial AZ31 magnesium alloy sheet...... cleaning the AZ31 sheet. However, to obtain reasonable corrosion resistance at least 5 mu m of the surface of AZ31 magnesium alloy sheet have to be removed....

36 CFR 909.140 - Employment.

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2010-07-01

... 36 Parks, Forests, and Public Property 3 2010-07-01 2010-07-01 false Employment. 909.140 Section... DEVELOPMENT CORPORATION § 909.140 Employment. No qualified handicapped person shall, on the basis of handicap, be subjected to discrimination in employment under any program or activity conducted by the agency...

36 CFR 812.140 - Employment.

Science.gov (United States)

2010-07-01

... 36 Parks, Forests, and Public Property 3 2010-07-01 2010-07-01 false Employment. 812.140 Section... PRESERVATION § 812.140 Employment. No qualified handicapped person shall, on the basis of handicap, be subjected to discrimination in employment under any program or activity conducted by the agency. The...

36 CFR 406.140 - Employment.

Science.gov (United States)

2010-07-01

... 36 Parks, Forests, and Public Property 3 2010-07-01 2010-07-01 false Employment. 406.140 Section... COMMISSION § 406.140 Employment. No qualified handicapped person shall, on the basis of handicap, be subjected to discrimination in employment under any program or activity conducted by the agency. The...

36 CFR 1208.140 - Employment.

Science.gov (United States)

2010-07-01

... 36 Parks, Forests, and Public Property 3 2010-07-01 2010-07-01 false Employment. 1208.140 Section... ARCHIVES AND RECORDS ADMINISTRATION § 1208.140 Employment. No qualified individual with handicaps shall, on the basis of handicap, be subject to discrimination in employment under any program or activity...

17 CFR 149.140 - Employment.

Science.gov (United States)

2010-04-01

... 17 Commodity and Securities Exchanges 1 2010-04-01 2010-04-01 false Employment. 149.140 Section... COMMISSION § 149.140 Employment. No qualified handicapped person shall, on the basis of handicap, be subjected to discrimination in employment under any program or activity conducted by the agency. The...

38 CFR 15.140 - Employment.

Science.gov (United States)

2010-07-01

... 38 Pensions, Bonuses, and Veterans' Relief 1 2010-07-01 2010-07-01 false Employment. 15.140... § 15.140 Employment. No qualified individual with handicaps shall, on the basis of handicap, be subject to discrimination in employment under any program or activity conducted by the agency. The...

31 CFR 17.140 - Employment.

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2010-07-01

... 31 Money and Finance: Treasury 1 2010-07-01 2010-07-01 false Employment. 17.140 Section 17.140... Employment. No qualified individual with handicaps shall, on the basis of handicap, be subjected to discrimination in employment under any program or activity conducted by the Department. The definitions...

36 CFR 1154.140 - Employment.

Science.gov (United States)

2010-07-01

... 36 Parks, Forests, and Public Property 3 2010-07-01 2010-07-01 false Employment. 1154.140 Section... ARCHITECTURAL AND TRANSPORTATION BARRIERS COMPLIANCE BOARD § 1154.140 Employment. No qualified handicapped person shall, on the basis of handicap, be subjected to discrimination in employment under any program or...

13 CFR 136.140 - Employment.

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2010-01-01

... 13 Business Credit and Assistance 1 2010-01-01 2010-01-01 false Employment. 136.140 Section 136....140 Employment. (a) No qualified individual with handicaps shall, on the basis of handicap, be subjected to discrimination in employment under any program, or activity conducted by the Agency. (b) The...

A biodegradable AZ91 magnesium alloy coated with a thin nanostructured hydroxyapatite for improving the corrosion resistance.

Science.gov (United States)

Mukhametkaliyev, T M; Surmeneva, M A; Vladescu, A; Cotrut, C M; Braic, M; Dinu, M; Vranceanu, M D; Pana, I; Mueller, M; Surmenev, R A

2017-06-01

The main aim of this study was to investigate the properties of an AZ91 alloy coated with nanostructured hydroxyapatite (HA) prepared by radio frequency (RF) magnetron sputtering. The bioactivity and biomineralization of the AZ91 magnesium alloy coated with HA were investigated in simulated body fluid (SBF) via an in vitro test. Scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, and X-ray diffraction (XRD) analyses were performed. The samples were immersed in SBF to study the ability of the surface to promote the formation of an apatite layer as well as corrosion resistance and mass change of the HA-coated AZ91 alloy. Electrochemical tests were performed to estimate the corrosion behaviour of HA-coated and uncoated samples. The results revealed the capability of the HA coating to significantly improve the corrosion resistance of the uncoated AZ91 alloy. Copyright © 2017 Elsevier B.V. All rights reserved.

44 CFR 19.140 - Dissemination of policy.

Science.gov (United States)

2010-10-01

... ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Introduction § 19.140 Dissemination of policy. (a... 44 Emergency Management and Assistance 1 2010-10-01 2010-10-01 false Dissemination of policy. 19.140 Section 19.140 Emergency Management and Assistance FEDERAL EMERGENCY MANAGEMENT AGENCY, DEPARTMENT...

40 CFR 52.140 - Monitoring transportation trends.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 3 2010-07-01 2010-07-01 false Monitoring transportation trends. 52.140 Section 52.140 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS Arizona § 52.140 Monitoring transportation...

Development of AZS refractories for the glass industry

International Nuclear Information System (INIS)

Guzman, A.M.; Rodriguez, P.

2004-01-01

Refractory materials can support high temperatures, thermal strength and the contact with aggressive environments, for this reason they are widely used in the cement, glass and steel industry. Commercial AZS (alumina-zirconia-silica) refractories are a good alternative in refractory materials for the glass industry' because they can support the aggressive conditions during liquid processing of glass. However, another problem encountered in glass industry is contamination by refractory' material that fall into the molten glass, which can produce a series of defects in the final product. This research was conducted to develop new formulations of AZS refractories with different amounts of ZrO 2 with the purpose of improving the characteristics, properties and the work conditions in the glass melting furnaces and, at the same time, lower the costs this type of refractories. The results obtained indicate that the composition with low content of ZrO 2 can provide better properties than the commercial product, with some modifications in the particle size distribution. Copyright (2004) AD-TECH - International Foundation for the Advancement of Technology Ltd

75 FR 883 - Environmental Impact Statement; Maricopa County, AZ

Science.gov (United States)

2010-01-06

...; Maricopa County, AZ AGENCY: Federal Highway Administration (FHWA), DOT. ACTION: Notice of Intent. SUMMARY...: (602) 382-8998, e-mail: [email protected] SUPPLEMENTARY INFORMATION: The FHWA, in cooperation with the... reasonable alternatives will be considered including: (1) Taking no action; (2) using alternate travel modes...

21 CFR 812.140 - Records.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Records. 812.140 Section 812.140 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES... disposed of. (3) Records of each subject's case history and exposure to the device. Case histories include...

18 CFR 1313.140 - Employment.

Science.gov (United States)

2010-04-01

... 18 Conservation of Power and Water Resources 2 2010-04-01 2010-04-01 false Employment. 1313.140... § 1313.140 Employment. No qualified handicapped person shall, on the basis of handicap, be subjected to discrimination in employment under any program or activity conducted by the agency. The definitions, requirements...

44 CFR 16.140 - Employment.

Science.gov (United States)

2010-10-01

... 44 Emergency Management and Assistance 1 2010-10-01 2010-10-01 false Employment. 16.140 Section 16... CONDUCTED BY THE FEDERAL EMERGENCY MANAGEMENT AGENCY § 16.140 Employment. No qualified individual with handicaps shall, on the basis of handicap, be subject to discrimination in employment under any program or...

10 CFR 140.6 - Reports.

Science.gov (United States)

2010-01-01

... 10 Energy 2 2010-01-01 2010-01-01 false Reports. 140.6 Section 140.6 Energy NUCLEAR REGULATORY... Reports. (a) In the event of bodily injury or property damage arising out of or in connection with the... records and furnish such reports to the Commission as the Commission deems necessary for the...

Effects of sintering temperature on the corrosion behavior of AZ31 alloy with Ca–P sol–gel coating

Energy Technology Data Exchange (ETDEWEB)

Niu, Bo [School of Materials Science and Engineering, Liaoning University of Technology, Jinzhou, Liaoning Province, 121001 (China); Shi, Ping, E-mail: p_shi@sohu.com [School of Materials Science and Engineering, Liaoning University of Technology, Jinzhou, Liaoning Province, 121001 (China); Wei, Donghua [School of Materials Science and Engineering, Liaoning University of Technology, Jinzhou, Liaoning Province, 121001 (China); E, Shanshan [School of Mathematics and Physics, Bohai University, Jinzhou, Liaoning Province, 121013 (China); Li, Qiang; Chen, Yang [School of Materials Science and Engineering, Liaoning University of Technology, Jinzhou, Liaoning Province, 121001 (China)

2016-04-25

To slow down the initial biodegradation rate of magnesium alloy, calcium phosphate (Ca–P) coatings were prepared on AZ31 magnesium alloy by a sol–gel technique. To study the effects of sintering temperature on microstructure, bonding strength and corrosion behavior of the coatings, scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD) and an adhesive strength test were used to characterize the coatings. The corrosion resistance of the coatings was investigated by immersion test and electrochemical corrosion techniques in simulated body fluid (SBF) solution. It shows that the sol–gel coatings consist of Ca{sub 2}P{sub 2}O{sub 7}, mixture of Ca{sub 2}P{sub 2}O{sub 7}, Ca{sub 3}(PO{sub 4}){sub 2} and hydroxyapatite, and hydroxyapatite, by sintering respectively at 300 °C, 400 °C and 500 °C. There are major cracks on the coatings. The crack area portion on the coating and the bonding strength at the interface between the calcium phosphate coating and the bare AZ31 increases, and the corrosion resistance of the coated AZ31 in SBF decreases with increasing sintering temperatures from 300 °C to 500 °C. Based on our investigations, the corrosion resistance of the coated AZ31 in SBF depends mainly on the crack area portion on the coatings, rather than on the coating phase stability. - Highlights: • Ca–P coating was prepared on AZ31 alloy by a sol–gel technique. • Crack area portion in the coating increases with temperatures. • Bonding strength between Ca–P coating and substrate increases with temperatures. • Corrosion resistance of the coated AZ31 in SBF decreases with temperatures. • Corrosion resistance of the coated AZ31 depends mainly on the crack area portion.

The Schizosaccharomyces pombe JmjC-protein, Msc1, prevents H2A.Z localization in centromeric and subtelomeric chromatin domains.

Directory of Open Access Journals (Sweden)

Luke Buchanan

2009-11-01

Full Text Available Eukaryotic genomes are repetitively packaged into chromatin by nucleosomes, however they are regulated by the differences between nucleosomes, which establish various chromatin states. Local chromatin cues direct the inheritance and propagation of chromatin status via self-reinforcing epigenetic mechanisms. Replication-independent histone exchange could potentially perturb chromatin status if histone exchange chaperones, such as Swr1C, loaded histone variants into wrong sites. Here we show that in Schizosaccharomyces pombe, like Saccharomyces cerevisiae, Swr1C is required for loading H2A.Z into specific sites, including the promoters of lowly expressed genes. However S. pombe Swr1C has an extra subunit, Msc1, which is a JumonjiC-domain protein of the Lid/Jarid1 family. Deletion of Msc1 did not disrupt the S. pombe Swr1C or its ability to bind and load H2A.Z into euchromatin, however H2A.Z was ectopically found in the inner centromere and in subtelomeric chromatin. Normally this subtelomeric region not only lacks H2A.Z but also shows uniformly lower levels of H3K4me2, H4K5, and K12 acetylation than euchromatin and disproportionately contains the most lowly expressed genes during vegetative growth, including many meiotic-specific genes. Genes within and adjacent to subtelomeric chromatin become overexpressed in the absence of either Msc1, Swr1, or paradoxically H2A.Z itself. We also show that H2A.Z is N-terminally acetylated before, and lysine acetylated after, loading into chromatin and that it physically associates with the Nap1 histone chaperone. However, we find a negative correlation between the genomic distributions of H2A.Z and Nap1/Hrp1/Hrp3, suggesting that the Nap1 chaperones remove H2A.Z from chromatin. These data describe H2A.Z action in S. pombe and identify a new mode of chromatin surveillance and maintenance based on negative regulation of histone variant misincorporation.

7 CFR 65.140 - Food service establishment.

Science.gov (United States)

2010-01-01

... retail establishments that provide ready-to-eat foods that are consumed either on or outside of the... 7 Agriculture 3 2010-01-01 2010-01-01 false Food service establishment. 65.140 Section 65.140..., PEANUTS, AND GINSENG General Provisions Definitions § 65.140 Food service establishment. Food service...

33 CFR 118.140 - Painting bridge piers.

Science.gov (United States)

2010-07-01

... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Painting bridge piers. 118.140 Section 118.140 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES BRIDGE LIGHTING AND OTHER SIGNALS § 118.140 Painting bridge piers. The District Commander may require...

Influence of Sulfate-Reducing Bacteria on the Corrosion Residual Strength of an AZ91D Magnesium Alloy

Science.gov (United States)

Zhu, Xianyong; Liu, Yaohui; Wang, Qiang; Liu, Jiaan

2014-01-01

In this paper, the corrosion residual strength of the AZ91D magnesium alloy in the presence of sulfate-reducing bacteria is studied. In the experiments, the chemical composition of corrosion film was analyzed by a scanning electron microscope with energy dispersive X-ray spectroscopy. In addition, a series of instruments, such as scanning electronic microscope, pH-meter and an AG-10TA materials test machine, were applied to test and record the morphology of the corrosion product, fracture texture and mechanical properties of the AZ91D magnesium alloy. The experiments show that the sulfate-reducing bacteria (SRB) play an important role in the corrosion process of the AZ91D magnesium alloy. Pitting corrosion was enhanced by sulfate-reducing bacteria. Corrosion pits are important defects that could lead to a significant stress concentration in the tensile process. As a result, sulfate-reducing bacteria influence the corrosion residual strength of the AZ91D magnesium alloy by accelerating pitting corrosion. PMID:28788236

Reproducción de Micropterus salmoides (Pisces: Centrarchidae, en el embalse Gustavo Díaz Ordaz, Sinaloa, México

Directory of Open Access Journals (Sweden)

Rigoberto Beltrán Alvarez

2013-09-01

Full Text Available Micropterus salmoides es un pez de importancia para la pesca deportiva en la mayoría de los embalses de México y del mundo, por lo que en el embalse Gustavo Díaz Ordaz se realizó un estudio sobre aspectos reproductivos entre agosto 2008 y marzo 2011. Se recolectaron 938 organismos, a los cuales se les midió la longitud (Lt cm, peso (Pt g, se determinó el sexo, índice gonadosomático, factor de condición, fecundidad y talla de primera madurez. La longitud y peso de los ejemplares recolectados varió de 15.9 a 63 cm (37.4±78.0 y de 57 a 4 431g (731.7±619.0, respectivamente. La relación peso total-longitud total se ajustó a un modelo tipo potencial, el crecimiento fue alométrico positivo, no se obtuvieron diferencias significativas entre machos y hembras (F=0.9955, p=0.3187. La proporción macho-hembra fue 1:0.83. Los desoves masivos inician en diciembre y finalizan en abril. La talla de primera reproducción fue de 33.7cm y la fecundidad promedio de 32 294±12 878.7 ovocitos/hembra. El índice gonadosomático se mantuvo bajo desde mayo hasta noviembre y alto entre enero y marzo. El factor de condición registró valores altos previos al desove y disminuyó al final del periodo reproductivo.

Tank 241-AZ-101 criticality assessment resulting from pump jet mixing: Sludge mixing simulation

Energy Technology Data Exchange (ETDEWEB)

Onishi, Y.; Recknagle, K.

1997-04-01

Tank 241-AZ-101 (AZ-101) is one of 28 double-shell tanks located in the AZ farm in the Hanford Site`s 200 East Area. The tank contains a significant quantity of fissile materials, including an estimated 9.782 kg of plutonium. Before beginning jet pump mixing for mitigative purposes, the operations must be evaluated to demonstrate that they will be subcritical under both normal and credible abnormal conditions. The main objective of this study was to address a concern about whether two 300-hp pumps with four rotating 18.3-m/s (60-ft/s) jets can concentrate plutonium in their pump housings during mixer pump operation and cause a criticality. The three-dimensional simulation was performed with the time-varying TEMPEST code to determine how much the pump jet mixing of Tank AZ-101 will concentrate plutonium in the pump housing. The AZ-101 model predicted that the total amount of plutonium within the pump housing peaks at 75 g at 10 simulation seconds and decreases to less than 10 g at four minutes. The plutonium concentration in the entire pump housing peaks at 0.60 g/L at 10 simulation seconds and is reduced to below 0.1 g/L after four minutes. Since the minimum critical concentration of plutonium is 2.6 g/L, and the minimum critical plutonium mass under idealized plutonium-water conditions is 520 g, these predicted maximums in the pump housing are much lower than the minimum plutonium conditions needed to reach a criticality level. The initial plutonium maximum of 1.88 g/L still results in safety factor of 4.3 in the pump housing during the pump jet mixing operation.

Tank 241-AZ-101 criticality assessment resulting from pump jet mixing: Sludge mixing simulation

International Nuclear Information System (INIS)

Onishi, Y.; Recknagle, K.

1997-04-01

Tank 241-AZ-101 (AZ-101) is one of 28 double-shell tanks located in the AZ farm in the Hanford Site's 200 East Area. The tank contains a significant quantity of fissile materials, including an estimated 9.782 kg of plutonium. Before beginning jet pump mixing for mitigative purposes, the operations must be evaluated to demonstrate that they will be subcritical under both normal and credible abnormal conditions. The main objective of this study was to address a concern about whether two 300-hp pumps with four rotating 18.3-m/s (60-ft/s) jets can concentrate plutonium in their pump housings during mixer pump operation and cause a criticality. The three-dimensional simulation was performed with the time-varying TEMPEST code to determine how much the pump jet mixing of Tank AZ-101 will concentrate plutonium in the pump housing. The AZ-101 model predicted that the total amount of plutonium within the pump housing peaks at 75 g at 10 simulation seconds and decreases to less than 10 g at four minutes. The plutonium concentration in the entire pump housing peaks at 0.60 g/L at 10 simulation seconds and is reduced to below 0.1 g/L after four minutes. Since the minimum critical concentration of plutonium is 2.6 g/L, and the minimum critical plutonium mass under idealized plutonium-water conditions is 520 g, these predicted maximums in the pump housing are much lower than the minimum plutonium conditions needed to reach a criticality level. The initial plutonium maximum of 1.88 g/L still results in safety factor of 4.3 in the pump housing during the pump jet mixing operation

Tank 241-AZ-102 Privatization Push Mode Core Sampling and Analysis Plan

International Nuclear Information System (INIS)

RASMUSSEN, J.H.

1999-01-01

This sampling and analysis plan (SAP) identifies characterization objectives pertaining to sample collection, laboratory analytical evaluation, and reporting requirements for samples obtained from tank 241-AZ-102. The purpose of this sampling event is to obtain information about the characteristics of the contents of 241-AZ-102 required to satisfy the Data Quality Objectives For TWRS Privatization Phase I : Confirm Tank TIS An Appropriate Feed Source For High-Level Waste Feed Batch X(HLW DQO) (Nguyen 1999a), Data Quality Objectives For TWRS Privatization Phase 1: Confirm Tank TIS An Appropriate Feed Source For Low-Activity Waste Feed Batch X (LAW DQO) (Nguyen 1999b), Low Activity Waste and High Level Waste Feed Data Quality Objectives (L and H DQO) (Patello et al. 1999) and Characterization Data Needs for Development, Design, and Operation of Retrieval Equipment Developed through the Data Quality Objective Process (Equipment DQO) (Bloom 1996). The Tank Characterization Technical Sampling Basis document (Brown et al. 1998) indicates that these issues, except the Equipment DQO apply to tank 241-AZ-102 for this sampling event. The Equipment DQO is applied for shear strength measurements of the solids segments only. Poppiti (1999) requires additional americium-241 analyses of the sludge segments. Brown et al. (1998) also identify safety screening, regulatory issues and provision of samples to the Privatization Contractor(s) as applicable issues for this tank. However, these issues will not be addressed via this sampling event. Reynolds et al. (1999) concluded that information from previous sampling events was sufficient to satisfy the safety screening requirements for tank 241-AZ-102. Push mode core samples will be obtained from risers 15C and 24A to provide sufficient material for the chemical analyses and tests required to satisfy these data quality objectives. The 222-S Laboratory will extrude core samples, composite the liquids and solids, perform chemical analyses

24 CFR 990.140 - Occupied dwelling units.

Science.gov (United States)

2010-04-01

... 24 Housing and Urban Development 4 2010-04-01 2010-04-01 false Occupied dwelling units. 990.140 Section 990.140 Housing and Urban Development Regulations Relating to Housing and Urban Development... Eligible Unit Months § 990.140 Occupied dwelling units. A PHA is eligible to receive operating subsidy for...

Lactancia materna, alimentación artificial y el primer contacto con azúcar

Directory of Open Access Journals (Sweden)

Fabian Calixto Fraiz

2013-01-01

Full Text Available Objetivo: Este estudio evaluó los cambios en el patrón de lactancia materna, alimentación artificial y en la introducción de azúcar en la dieta de niños de 0 a 36 meses, a través de dos estudios, con un intervalo de 13 años en la ciudad de Curitiba, Paraná, Brasil. Material y métodos: Poblaciones semejantes de una misma región geográfica fueron evaluadas a través de un cuestionario, en los años de 1993 y 2006, envolviendo, respectivamente, las madres de 180 y 94 niños. Introducción de azúcar en la dieta fue considerada precoz cuando ocurrió antes del 6º mes completo de vida. Los datos fueron analizados estadísticamente a través del test de qui-cuadrado y test exacto de Fisher (α= 0,05. Resultados: Hubo diferencias en la frecuencia del primer contacto con azúcar (p <0,001, que ocurrió en el primer mes de vida en 61,7% de los niños del primer estudio y en sólo 3,2% de los niños del segundo estudio. Hubo diferencias en el patrón de lactancia materna (p = 0,02, siendo la prevalencia de niños amamantados mayor en el segundo estudio. No fueron encontradas diferencias estadísticamente significativas en la prevalencia de uso de biberón, uso de biberón durante la noche y lactancia materna durante la noche, así como en el uso de biberón conteniendo azúcar. Conclusiones: Estos resultados indican que la lactancia materna puede, además de sus varias ventajas, también promover el aplazamiento de la introducción de azúcar en la dieta infantil. Nuevas investigaciones son necesarias para confirmar esta hipótesis.

Insomnio, latencia al sueño y cantidad de sueño en estudiantes universitarios chilenos durante el periodo de clases y exámenes

Directory of Open Access Journals (Sweden)

Samuel Durán Agüero

2017-01-01

Full Text Available Objetivo:Determinar los factores asociados a la cantidad de horas de sueño, somnolenciadiurna e insomnio antes y durante un periodo de clases y exámenes.Material y métodos:Se evaluó a 384 alumnos de ambos sexos (74,1% mujeres, quienesreportaron su peso y estatura. A cada estudiante se le aplicó el Cuestionario de Insomnio y laEscala De Somnolencia de Epworth en el periodo de clases y periodo de exámenes.Resultados:Al comparar la somnolencia diurna, insomnio, latencia al sueño y cantidad dehoras de sueño entre periodo de clases y exámenes se observó un incremento en la latencia alsueño (p<0,05 durante los exámenes. Al realizar la comparación según estado nutricional seobservó, en el caso de las mujeres, que aquellas que presentan sobrepeso/obesidad tienen unamenor cantidad de horas de sueño en ambos periodos (p<0,05; en hombres, los que presentansobrepeso/obesidad tienen una mayor somnolencia diurna en exámenes (p<0,01. Al realizarla regresión logística tomando como variable dependiente somnolencia diurna, en mujeres seincrementa el riesgo de somnolencia diurna:OR=3,1 (IC95 % 1,1-8,8; en cambio, la ausenciade insomnio es un factor protector para somnolencia diurna:OR=0,06 (IC95 % 0,01-0,35.Conclusión:En periodo de exámenes se incrementa significativamente la latencia al sueño, enespecial en mujeres; en hombres se observa una disminución de las horas de sueño. Finalmente, las mujeres presentan un mayor riesgo de somnolencia diurna; en cambio, la ausencia deinsomnio es un factor protector. Ni el estado nutricional ni el consumo de cafeína se asociaroncon problemas de sueño.

Enrique Díaz and Present Phpotographies (From Graphic Notes to Photo-essays

Directory of Open Access Journals (Sweden)

Rebeca Monroy Nasr

1998-10-01

Full Text Available With "Enrique Díaz and Present Phpotographies (From Graphic Notes to Photo-essays ", the author presents part of our photo­graphic history, as well as some aspects of its development as a form of journalism and of art. She rescues the figure of Enrique Díaz Reyna as representative of the union of graphic journalists, due to his technical, formal and conceptual traits, all of them tools with which he opened important paths and innovative graphical and aesthetic proposals. This essay presents some aspects of the graphic journalist's work in Mexico City, from the twenties to the forties. As a guide to the photographer's extensi­ve work, the author reviews some of the proposals he made as his work became more mature: first, the graphic note, later, recrea­ting the photo-reportage, and finally, exploring with photoessays. Thus, attention is centered particularly on Díaz Reyna's visual language, where the signs of a distinctive modernity appro­priate of his time allow us to understand a substantial part of the transition towards a contemporary and  truly national photo-journalism.

Anticorrosive magnesium hydroxide coating on AZ31 magnesium alloy by hydrothermal method

International Nuclear Information System (INIS)

Zhu Yanying; Wu Guangming; Xing Guangjian; Li Donglin; Zhao Qing; Zhang Yunhong

2009-01-01

Magnesium alloys are potential biodegradable biomaterials in orthopedic surgery. However, the rapid degradation rate has limited their application in biomedical field. A great deal of studies have been done to improve the resistance of magnesium alloys. In this article, An anticorrosive magnesium hydroxide coating with a thickness of approximately 100μm was formed on an AZ31 magnesium alloy by hydrothermal method. The morphology of the coatings were observed by an optical microscope and SEM. And the samples were soaked in hank's solution (37 deg. C) to investigate the corrosion resistance. Magnesium alloy AZ31 with magnesium hydroxide coatings present superior corrosion resistance than untreated samples.

21 CFR 146.140 - Pasteurized orange juice.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 2 2010-04-01 2010-04-01 false Pasteurized orange juice. 146.140 Section 146.140... and Beverages § 146.140 Pasteurized orange juice. (a) Pasteurized orange juice is the food prepared from unfermented juice obtained from mature oranges as specified in § 146.135, to which may be added...

The effects of zirconium and beryllium on microstructure evolution, mechanical properties and corrosion behaviour of as-cast AZ63 alloy

International Nuclear Information System (INIS)

Jafari, Hassan; Amiryavari, Peyman

2016-01-01

Alloying elements are able to strongly modify the microstructure characteristics of Mg–Al–Zn alloys which dominate mechanical and corrosion properties of the alloys. In this research, the individual effects of Zr and Be additions on the microstructure, mechanical and corrosion properties of as-cast AZ63 alloy were explored. The results revealed that the addition of Zr leads to microstructure refinement in as-cast AZ63 alloy, resulting in improved tensile and hardness properties. 0.0001 and 0.001 wt% Be containing cast AZ63 alloy exhibited microstructure coarsening, while morphological alteration from sixford symmetrical to irregular shape grain was observed for the alloy containing 0.01 and 0.1 wt% Be. No specific Be compound was detected. In addition, mechanical properties of AZ63 alloy containing Zr was improved due to the microstructure modification, while Be containing alloy responded reverse behaviour. The corrosion resistance of AZ63 alloy was improved after the addition of Zr and Be due to the grain refinement and passivation effects, respectively. However, when the Zr content exceeds 0.5 wt%, the formation of Al 2 Zr affected the corrosion resistance. In other words, AZ63–0.5Zr alloy provided the lowest corrosion rate.

The Effects of Rare Earth Pr and Heat Treatment on the Wear Properties of AZ91 Alloy

Directory of Open Access Journals (Sweden)

Ning Li

2018-06-01

Full Text Available This paper investigated the influences of Pr addition and heat treatment (T6 on the dry sliding wear behavior of AZ91 alloy. The wear rates and friction coefficients were measured by using a pin-on-disc tribometer under loads of 30, 60 and 90 N at dry sliding speeds of 100 rpm, over a sliding time of 15 min. The worn surfaces were examined using a scanning electron microscope and was analyzed with an energy dispersive spectrometer. The experimental results revealed that AZ91-1.0%Pr magnesium alloy exhibited lower wear rate and friction coefficient than the other investigated alloys. As the applied load increased, the wear rate and friction coefficient increased. Compared with the as-cast AZ91-1.0%Pr magnesium alloy, the hardness and wear resistance of the alloy after solution treatment were reduced, and through the subsequent aging, the hardness and wear resistance of the alloy were improved and the hardness was 101.1 HB (compared to as-cast AZ91 magnesium alloy, it increased by 45%. The AZ91-1.0%Pr with T6 magnesium alloy exhibited best wear resistance. Abrasion was dominant at load of 30 N, delamination was dominant at load of 60 N and plastic deformation was dominant at load of 90 N. Oxidation was observed at all loads.

Multivalent binding of PWWP2A to H2A.Z regulates mitosis and neural crest differentiation.

Science.gov (United States)

Pünzeler, Sebastian; Link, Stephanie; Wagner, Gabriele; Keilhauer, Eva C; Kronbeck, Nina; Spitzer, Ramona Mm; Leidescher, Susanne; Markaki, Yolanda; Mentele, Edith; Regnard, Catherine; Schneider, Katrin; Takahashi, Daisuke; Kusakabe, Masayuki; Vardabasso, Chiara; Zink, Lisa M; Straub, Tobias; Bernstein, Emily; Harata, Masahiko; Leonhardt, Heinrich; Mann, Matthias; Rupp, Ralph Aw; Hake, Sandra B

2017-08-01

Replacement of canonical histones with specialized histone variants promotes altering of chromatin structure and function. The essential histone variant H2A.Z affects various DNA-based processes via poorly understood mechanisms. Here, we determine the comprehensive interactome of H2A.Z and identify PWWP2A as a novel H2A.Z-nucleosome binder. PWWP2A is a functionally uncharacterized, vertebrate-specific protein that binds very tightly to chromatin through a concerted multivalent binding mode. Two internal protein regions mediate H2A.Z-specificity and nucleosome interaction, whereas the PWWP domain exhibits direct DNA binding. Genome-wide mapping reveals that PWWP2A binds selectively to H2A.Z-containing nucleosomes with strong preference for promoters of highly transcribed genes. In human cells, its depletion affects gene expression and impairs proliferation via a mitotic delay. While PWWP2A does not influence H2A.Z occupancy, the C-terminal tail of H2A.Z is one important mediator to recruit PWWP2A to chromatin. Knockdown of PWWP2A in Xenopus results in severe cranial facial defects, arising from neural crest cell differentiation and migration problems. Thus, PWWP2A is a novel H2A.Z-specific multivalent chromatin binder providing a surprising link between H2A.Z, chromosome segregation, and organ development. © 2017 The Authors.

Dictionary of engines. The internal combustion engine from A-Z; Lexikon Motorentechnik. Der Verbrennungsmotor von A-Z

Energy Technology Data Exchange (ETDEWEB)

Schaefer, F. (ed.); Basshuysen, R. van

2004-04-01

This dictionary describes current engine technology and gives an outlook to the future. Cross-references, broader and narrower terms ensure optimal user guidance. Entries do not stand alone but provide content-oriented information. About 4,500 terms are included from A-Z, providing an outline of subjects like exhaust systems, acoustics, supercharging, combustion chamber, injection systems, control, flame propagation, mixing, catalytic converters, pistons, fuels, cooling, crank casing, stratified charging, lambda control, camshaft, oil, particulate filters, sensors/actuators, pollutants, valves, combustion processes, efficiency, ignition, cylinder head. The dictionary is for development engineers in the motor car industry, in component and system development in the supply industry, university teachers and students, foremen in motor car repair shops, etc. (orig.) [German] Das Lexikon Motorentechnik ist ein Nachschlagewerk, das die aktuelle Motorentechnik umfassend beschreibt und Ausblicke in der Zukunft ermoeglicht. Das ausgefeilte System aus Querverweisen fuehrt alle Unterbegriffe zum Hauptbegriff und ermoeglicht so eine optimale Benutzerfuehrung. Dadurch stehen die Stichwoerter nicht isoliert, sondern es werden inhaltlich zusammenhaengende Betrachtungen moeglich. Der Inhalt umfasst 4 500 Begriffe von A-Z wie z.B.: Abgastechnik, Akustik, Aufladung, Brennraum, Einspritzsysteme, Elektronische Motorsteuerung, Flammenausbreitung, Gemischbildung, Katalysator, Kolben, Kraftstoff, Kuehlung, Kurbelgehaeuse, Kurbeltrieb, Ladungswechsel, Lambda-Regelung, Nockenwelle, Oel, Partikelfilter, Sensoren/Aktuatoren, Schadstoffe, Ventiltrieb, Verbrennungsverfahren, Wirkungsgrad, Zuendung, Zylinderkopf. Die Zielgruppen waeren Ingenieure in Motoren- und Fahrzeugentwicklung der Automobilindustrie, Ingenieure in der Komponenten- und Systementwicklung der Zuliefererindustrie, Professoren und Studenten an Hochschulen mit Schwerpunkt Kraftfahrzeugtechnik, Meister in Kfz-Werkstaetten. (orig.)

Systematic understanding of corrosion behavior of plasma electrolytic oxidation treated AZ31 magnesium alloy using a mouse model of subcutaneous implant

Energy Technology Data Exchange (ETDEWEB)

Jang, Yongseok [Engineering Research Center for Revolutionizing Metallic Biomaterials (ERC-RMB), North Carolina A and T State University, Greensboro, NC, 27411 (United States); Tan, Zongqing [Internal Medicine, College of Medicine, University of Cincinnati, OH 45211 (United States); Jurey, Chris [Luke Engineering, Wadsworth, OH 44282 (United States); Collins, Boyce [Engineering Research Center for Revolutionizing Metallic Biomaterials (ERC-RMB), North Carolina A and T State University, Greensboro, NC, 27411 (United States); Badve, Aditya [Business and Biology, The University of North Carolina at Chapel Hill, NC 27514 (United States); Dong, Zhongyun [Internal Medicine, College of Medicine, University of Cincinnati, OH 45211 (United States); Park, Chanhee; Kim, Cheol Sang [Department of Bio-nano System Engineering, Chonbuk National University, Jeonju, Jeonbuk 561-756 (Korea, Republic of); Sankar, Jagannathan [Engineering Research Center for Revolutionizing Metallic Biomaterials (ERC-RMB), North Carolina A and T State University, Greensboro, NC, 27411 (United States); Yun, Yeoheung, E-mail: yyun@ncat.edu [Engineering Research Center for Revolutionizing Metallic Biomaterials (ERC-RMB), North Carolina A and T State University, Greensboro, NC, 27411 (United States)

2014-12-01

This study was conducted to identify the differences between corrosion rates, corrosion types, and corrosion products in different physiological environments for AZ31 magnesium alloy and plasma electrolytic oxidation (PEO) treated AZ31 magnesium alloy. In vitro and in vivo tests were performed in Hank's Balanced Salt Solution (HBSS) and mice for 12 weeks, respectively. The corrosion rates of both AZ31 magnesium alloy and PEO treated AZ31 magnesium alloy were calculated based on DC polarization curves, volume of hydrogen evolution, and the thickness of corrosion products formed on the surface. Micro X-ray computed tomography (Micro-CT), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX) and X-ray diffraction (XRD) were used to analyze morphological and chemical characterizations of corrosion products. The results show that there is more severe localized corrosion after in vitro test in HBSS; however, the thicknesses of corrosion products formed on the surface for AZ31 magnesium alloy and PEO treated AZ31 magnesium alloy in vivo were about 40% thicker than the thickness of corrosion products generated in vitro. The ratio of Ca and P (Ca/P) in the corrosion products also differed. The Ca deficient region and higher content of Al in corrosion product than AZ31 magnesium alloy were identified after in vivo test in contrast with the result of in vitro test. - Highlights: • Effects of plasma electrolytic oxidation on AZ31 in vitro and in vivo • Retardation of degradation via plasma electrolytic oxidation in vitro and in vivo • Differentiation of in vitro and in vivo corrosion types and products.

Systematic understanding of corrosion behavior of plasma electrolytic oxidation treated AZ31 magnesium alloy using a mouse model of subcutaneous implant

International Nuclear Information System (INIS)

Jang, Yongseok; Tan, Zongqing; Jurey, Chris; Collins, Boyce; Badve, Aditya; Dong, Zhongyun; Park, Chanhee; Kim, Cheol Sang; Sankar, Jagannathan; Yun, Yeoheung

2014-01-01

This study was conducted to identify the differences between corrosion rates, corrosion types, and corrosion products in different physiological environments for AZ31 magnesium alloy and plasma electrolytic oxidation (PEO) treated AZ31 magnesium alloy. In vitro and in vivo tests were performed in Hank's Balanced Salt Solution (HBSS) and mice for 12 weeks, respectively. The corrosion rates of both AZ31 magnesium alloy and PEO treated AZ31 magnesium alloy were calculated based on DC polarization curves, volume of hydrogen evolution, and the thickness of corrosion products formed on the surface. Micro X-ray computed tomography (Micro-CT), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX) and X-ray diffraction (XRD) were used to analyze morphological and chemical characterizations of corrosion products. The results show that there is more severe localized corrosion after in vitro test in HBSS; however, the thicknesses of corrosion products formed on the surface for AZ31 magnesium alloy and PEO treated AZ31 magnesium alloy in vivo were about 40% thicker than the thickness of corrosion products generated in vitro. The ratio of Ca and P (Ca/P) in the corrosion products also differed. The Ca deficient region and higher content of Al in corrosion product than AZ31 magnesium alloy were identified after in vivo test in contrast with the result of in vitro test. - Highlights: • Effects of plasma electrolytic oxidation on AZ31 in vitro and in vivo • Retardation of degradation via plasma electrolytic oxidation in vitro and in vivo • Differentiation of in vitro and in vivo corrosion types and products

The effect of PVD coatings on the corrosion behaviour of AZ91 magnesium alloy

International Nuclear Information System (INIS)

Altun, Hikmet; Sen, Sadri

2006-01-01

In this study, multilayered AlN (AlN + AlN + AlN) and AlN + TiN were coated on AZ91 magnesium alloy using physical vapour deposition (PVD) technique of DC magnetron sputtering, and the influence of the coatings on the corrosion behaviour of the AZ91 alloy was examined. A PVD system for coating processes, a potentiostat for electrochemical corrosion tests, X-ray difractometer for compositional analysis of the coatings, and scanning electron microscopy for surface examinations were used. It was determined that PVD coatings deposited on AZ91 magnesium alloy increased the corrosion resistance of the alloy, and AlN + AlN + AlN coating increased the corrosion resistance much more than AlN + TiN coating. However, it was observed that, in the coating layers, small structural defects e.g., pores, pinholes, cracks that could arise from the coating process or substrate and get the ability of protection from corrosion worsened were present

Impacto del reintegro tributario en los estados financieros de una empresa comercializadora de productos avícolas en el periodo 2007- 2009

OpenAIRE

Fernandez Ruíz, Sussann Lizbeth; Vásquez Del Águila, Juan Carlos

2011-01-01

El objetivo fue determinar el impacto del reintegro tributario en los estados financieros de la Empresa Comercializadora de productos avícolas "Don Pollo" de la ciudad de !quitos durante el periodo 2007-2009. La investigación fue documental, retrospectiva y de diseño descriptivo. La población estuvo constituida por el conjunto de estados financieros de la empresa comercializadora de productos avícolas "Don Pollo" y la muestra estuvo conformada por los estados financieros del periodo 2007-2009...

In vitro corrosion of magnesium alloy AZ31 — a synergetic influence of glucose and Tris

Science.gov (United States)

Li, Ling-Yu; Liu, Bin; Zeng, Rong-Chang; Li, Shuo-Qi; Zhang, Fen; Zou, Yu-Hong; Jiang, Hongwei George; Chen, Xiao-Bo; Guan, Shao-Kang; Liu, Qing-Yun

2018-05-01

Biodegradable Mg alloys have generated great interest for biomedical applications. Accurate predictions of in vivo degradation of Mg alloys through cost-effective in vivo evaluations require the latter to be conducted in an environment close to that of physiological scenarios. However, the roles of glucose and buffering agents in regulating the in vivo degradation performance of Mg alloys has not been elucidated. Herein, degradation behavior of AZ31 alloy is investigated by hydrogen evolution measurements, pH monitoring and electrochemical tests. Results indicate that glucose plays a content-dependent role in degradation of AZ31 alloy in buffer-free saline solution. The presence of a low concentration of glucose, i.e. 1.0 g/L, decreases the corrosion rate of Mg alloy AZ31, whereas the presence of 2.0 and 3.0 g/L glucose accelerates the corrosion rate during long term immersion in saline solution. In terms of Tris-buffered saline solution, the addition of glucose increases pH value and promotes pitting corrosion or general corrosion of AZ31 alloy. This study provides a novel perspective to understand the bio-corrosion of Mg alloys in buffering agents and glucose containing solutions.

Augmenting the Energy-Saving Impact of IEEE 802.3az via the Control Plane

OpenAIRE

Thaenchaikun , Chakadkit; Jakllari , Gentian; Paillassa , Béatrice

2015-01-01

International audience; IEEE 802.3az, the recent standard for Energy Efficient Ethernet, is one of the main contributions of the ICT industry to the global quest for energy efficiency. Energy consumption reduction is accomplished by essentially replacing the continuous IDLE of legacy IEEE 802.3 cards with a Low Power Idle. While this is an important step in the right direction, studies have shown that the energy saving with IEEE 802.3az highly depends on the traffic load and stops for link ut...

Systematic understanding of corrosion behavior of plasma electrolytic oxidation treated AZ31 magnesium alloy using a mouse model of subcutaneous implant.

Science.gov (United States)

Jang, Yongseok; Tan, Zongqing; Jurey, Chris; Collins, Boyce; Badve, Aditya; Dong, Zhongyun; Park, Chanhee; Kim, Cheol Sang; Sankar, Jagannathan; Yun, Yeoheung

2014-12-01

This study was conducted to identify the differences between corrosion rates, corrosion types, and corrosion products in different physiological environments for AZ31 magnesium alloy and plasma electrolytic oxidation (PEO) treated AZ31 magnesium alloy. In vitro and in vivo tests were performed in Hank's Balanced Salt Solution (HBSS) and mice for 12 weeks, respectively. The corrosion rates of both AZ31 magnesium alloy and PEO treated AZ31 magnesium alloy were calculated based on DC polarization curves, volume of hydrogen evolution, and the thickness of corrosion products formed on the surface. Micro X-ray computed tomography (Micro-CT), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX) and X-ray diffraction (XRD) were used to analyze morphological and chemical characterizations of corrosion products. The results show that there is more severe localized corrosion after in vitro test in HBSS; however, the thicknesses of corrosion products formed on the surface for AZ31 magnesium alloy and PEO treated AZ31 magnesium alloy in vivo were about 40% thicker than the thickness of corrosion products generated in vitro. The ratio of Ca and P (Ca/P) in the corrosion products also differed. The Ca deficient region and higher content of Al in corrosion product than AZ31 magnesium alloy were identified after in vivo test in contrast with the result of in vitro test. Copyright © 2014 Elsevier B.V. All rights reserved.

Warm Deep Drawing of Rectangular Parts of AZ31 Magnesium Alloy Sheet Adopting Variable Blank Holder Force

International Nuclear Information System (INIS)

Peng Yinghong; Chang Qunfeng; Li Dayong; Zeng Xiaoqin

2007-01-01

AZ31 magnesium alloy sheet with good shape and formability is fabricated by warm cross rolling. Uniaxial tensile tests are conducted using a Gleeble 3500 thermal - mechanical simulator, and the mechanical properties of AZ31 magnesium alloy sheet are analyzed. A warm deep drawing process of square part is also simulated by the finite element method. The influences of blank holder force on the formability are numerically investigated. A double-action hydraulic press that can realize adjustable blank holder forces is developed and its working principle and control system are introduced. Some warm deep drawing experiments of square parts of AZ31 magnesium alloy sheet are also performed. Different variation schemes of the blank holder force with the stroke of the punch are tested, and the experiment results are compared. Results show that the suitable blank holder force variation scheme is a ladder curve with the punch stroke. Adopting the variable blank holder force technique can improve 13.2% of the drawing depth of square parts of AZ31 magnesium alloy sheet

Extracción de quitina utilizando ácido láctico

OpenAIRE

Colina Rincón, Marinela Nazareth; Medina Robles, Karen Dianne; Vargas Colina, José Alejandro; Rincón Prieto, Dianela Isabel; Arismendi, Rossana; Montilla, Brinolfo

2017-01-01

RESUMEN En este trabajo, se evaluó la extracción de quitina a partir de desechos de crustáceos involucrando la fermentación láctica generando ácido láctico para la  desproteinización y desmineralización del material, usando suero de leche y azúcar como sustrato y fuente de carbono, por un periodo de 2 y 3 semanas a temperatura ambiente. Los resultados mostraron que la concentración óptima de azúcar para la extracción de quitina de un 10% m/v, evidenciando un descenso del pH y consecue...

Synthesis and biological evaluation of [11C]AZ12504948; a novel tracer for imaging of glucokinase in pancreas and liver

International Nuclear Information System (INIS)

Jahan, M.; Johnström, P.; Nag, S.; Takano, A.; Korsgren, O.; Johansson, L.; Halldin, C.; Eriksson, O.

2015-01-01

Introduction: Glucokinase (GK) is potentially a target for imaging of islets of Langerhans. Here we report the radiosynthesis and preclinical evaluation of the GK activator, [ 11 C]AZ12504948, for in vivo imaging of GK. Methods: [ 11 C]AZ12504948 was synthesized by O-methylation of the precursor, AZ125555620, using carbon-11 methyl iodide ([ 11 C]CH 3 I). Preclinical evaluation was performed by autoradiography (ARG) of human tissues and PET/CT studies in pig and non-human primate. Result: [ 11 C]AZ12504948 was produced in reproducible good radiochemical yield in 28–30 min. Radiochemical purity of the formulated product was > 98% for up to 2 h with specific radioactivities 855 ± 209 GBq/μmol (n = 8). The preclinical evaluation showed some specificity for GK in liver, but not in pancreas. Conclusion: [ 11 C]AZ12504948 images GK in liver, but the low specificity impedes the visualization of GK in pancreas. Improved target specificity is required for further progress using PET probes based on this class of GK activators

Final Report for Crucible -Scale Radioactive Vitrification and Product Test of Waste Envelope B (AZ-102) Low-Activity Waste Glass

International Nuclear Information System (INIS)

CRAWFORD, CHARLES

2004-01-01

A proof-of-technology demonstration for the Hanford River Protection Project (RPP) Waste treatment and Immobilization Plant (WTP) was performed by the Savannah River Technology Center (SRTC). As part of this demonstration, treated AZ-102 Low-Activity Waste supernate was vitrified using a crucible-scale furnace. Initial glass samples were quench-cooled and characterized for metals and radionuclides. The glass was also durability tested using the American Society for Testing and Materials (ASTM) Product Consistency Test (PCT) protocol. These tests used the AZ-102 glass formulation Low Activity Waste (LAW) B88 that targeted AZ-102 waste loading at 5 wt% Na2O. After these initial results were obtained with the quench-cooled LAWB88 glass, a prototypical container centerline cooling (CCC) program was supplied to SRTC by WTP. A portion of the quench-cooled LAWB88 glass was remelted and centerline cooled. Samples from the CCC low-activity AZ-102 glass waste form were durability tested using the PCT and characterized for crystalline phase identification.This final report documents the characterization and durability of this AZ-102 glass

Tank 241-AZ-102 Privatization Push Mode Core Sampling and Analysis Plan

International Nuclear Information System (INIS)

TEMPLETON, A.M.

1999-01-01

This sampling and analysis plan (SAP) identifies characterization objectives pertaining to sample collection, laboratory analytical evaluation, and reporting requirements for samples obtained from tank 241-AZ-102

Tank 241-AZ-102 Privatization Push Mode Core Sampling and Analysis Plan

International Nuclear Information System (INIS)

RASMUSSEN, J.H.

2000-01-01

This sampling and analysis plan (SAP) identifies characterization objectives pertaining to sample collection, laboratory analytical evaluation, and reporting requirements for samples obtained from tank 241-AZ-102

78 FR 34403 - Notice of Availability of the Record of Decision for the Quartzsite Solar Energy Project, AZ

Science.gov (United States)

2013-06-07

...; AZA34666] Notice of Availability of the Record of Decision for the Quartzsite Solar Energy Project, AZ... Solar Energy Project (QSEP). The Acting Assistant Secretary for Land and Minerals Management approved...: http://www.blm.gov/az/st/en/prog/energy/solar/quartzsite_solar_energy.html . FOR FURTHER INFORMATION...

Development of a Ballistic Specification for Magnesium Alloy AZ31B

National Research Council Canada - National Science Library

Jones, Tyrone L; DeLorme, Richard D

2008-01-01

The U.S. Army Research Laboratory (ARL) and Magnesium Elektron North America (MENA) have conducted a joint effort to develop and evaluate rolled plate in commercially available magnesium alloy-temper AZ31B-H24...

Interfacial microstructure and mechanical properties of Cf/AZ91D composites with TiO2 and PyC fiber coatings.

Science.gov (United States)

Li, Shaolin; Qi, Lehua; Zhang, Ting; Ju, Luyan; Li, Hejun

2017-10-01

In spite of the effectiveness of the fiber coatings on interface modification of carbon fiber reinforced magnesium matrix composites, the cost and exclusive equipment for the coatings preparation are usually ignored during research work. In this paper, pyrolytic carbon (PyC) and TiO 2 were coated on carbon fiber surface to study the effects of fiber coatings on interfacial microstructure and mechanical properties of carbon fiber reinforced AZ91D composites (C f /AZ91D composites). It was indicated that both the two coatings could modify the interface and improve the mechanical properties of the composites. The ultimate tensile strength of the TiO 2 -C f /AZ91D and the PyC-C f /AZ91D composite were 333MPa and 400MPa, which were improved by 41.7% and 70.2% respectively, compared with the untreated-C f /AZ91D composite. The microstructure observation revealed that the strengthening of the composites relied on fiber integrity and moderate interfacial bonding. MgO nano-particles were generated at the interface due to the reaction of TiO 2 with Mg in the TiO 2 -C f /AZ91D composite. The volume expansion resulting from the reaction let to disordered intergranular films and crystal defects at the interface. The fibers were protected and the interfacial reaction was restrained by PyC coating in the PyC-C f /AZ91D composite. The principle to select the coating of fiber was proposed by comparing the effectiveness and cost of the coatings. Copyright © 2017 Elsevier Ltd. All rights reserved.

Correlative change of corrosion behavior with the microstructure of AZ91 Mg alloy modified with Y additions

International Nuclear Information System (INIS)

Jia, Ruiling; Zhang, Ming; Zhang, Lina; Zhang, Wei; Guo, Feng

2015-01-01

Highlights: • The effect of Y addition into the AZ91 Mg alloys was investigated. • Initial stage of corrosion was studied by in-situ 3D digital microscopy observation. • The potential difference was investigated by Kelvin probe force microscopy. • The effect of Y addition on the corrosion mechanisms of AZ91 alloy was studied. - Abstract: Microstructure characterization of the AZ91 magnesium alloys with or without rare earth element yttrium (Y) has been revealed by SEM, EDS and EPMA. Some Y-rich phases can be found in the magnesium alloys with Y additions. The fraction of β-Mg 17 Al 12 phase obvious decreases and turns into granular distribution with the increase of Y addition instead of original wet distribution along grain boundaries. The results of the potentiodynamic polarization tests show that the corrosion resistance of AZ91 alloy is improved with appropriate Y additions. But an in-situ observation of 3D digital microscopy for the initial stage of corrosion of the magnesium alloy with 0.9%Y addition shows that Y-rich phases act as cathodic effect and the α phases in the vicinity of them acting as anode are corroded. So the additions of Y have a beneficial effect that can depress the overall corrosion of AZ91 alloy, whereas its harmful effect is related to Y-rich phases because they present the highest Volta potential difference from the adjacent matrix and they can drive galvanic corrosion

Correlative change of corrosion behavior with the microstructure of AZ91 Mg alloy modified with Y additions

Energy Technology Data Exchange (ETDEWEB)

Jia, Ruiling, E-mail: jrl014014@163.com [College of Materials Science and Engineering, Inner Mongolia University of Technology, Hohhot, Inner Mongolia 010051 (China); Zhang, Ming; Zhang, Lina [College of Materials Science and Engineering, Inner Mongolia University of Technology, Hohhot, Inner Mongolia 010051 (China); Zhang, Wei [Laboratory for Corrosion and Protection, Institute of Metal Research, Chinese Academy of Sciences, 62 Wencui Road, Shenyang 110016 (China); Guo, Feng [College of Materials Science and Engineering, Inner Mongolia University of Technology, Hohhot, Inner Mongolia 010051 (China)

2015-06-15

Highlights: • The effect of Y addition into the AZ91 Mg alloys was investigated. • Initial stage of corrosion was studied by in-situ 3D digital microscopy observation. • The potential difference was investigated by Kelvin probe force microscopy. • The effect of Y addition on the corrosion mechanisms of AZ91 alloy was studied. - Abstract: Microstructure characterization of the AZ91 magnesium alloys with or without rare earth element yttrium (Y) has been revealed by SEM, EDS and EPMA. Some Y-rich phases can be found in the magnesium alloys with Y additions. The fraction of β-Mg{sub 17}Al{sub 12} phase obvious decreases and turns into granular distribution with the increase of Y addition instead of original wet distribution along grain boundaries. The results of the potentiodynamic polarization tests show that the corrosion resistance of AZ91 alloy is improved with appropriate Y additions. But an in-situ observation of 3D digital microscopy for the initial stage of corrosion of the magnesium alloy with 0.9%Y addition shows that Y-rich phases act as cathodic effect and the α phases in the vicinity of them acting as anode are corroded. So the additions of Y have a beneficial effect that can depress the overall corrosion of AZ91 alloy, whereas its harmful effect is related to Y-rich phases because they present the highest Volta potential difference from the adjacent matrix and they can drive galvanic corrosion.

Strongly coupled band in 140Gd

International Nuclear Information System (INIS)

Falla-Sotelo, F.; Oliveira, J.R.B.; Rao, M.N.

2005-01-01

Several high-K states are known to exist in the mass 130-140 region. For the N=74 even-even isotopes, Kπ = 8 - isomers, with lifetimes ranging from ns to ms, are known in 128 Xe, 130 Ba, 132 Ce, 134 Nd, 136 Sm, and 138 Gd[. In 140 Gd, we have observed for the first time a band also based on an Iπ = 8 - state. This could be the first case of a Kπ = 8 - state observed in an N=76 even-even isotope. The systematics of the Kπ = 8 - isomeric states in N=74 isotopes has been studied by A.M. Bruce et al. These states decay towards the K = 0 ground state band, and the transitions are K-forbidden. The 140 Gd case presents strong similarities but also some significant differences with relation to the N=74 isotopes. We propose the same configuration but with larger deformation in 140 Gd

Comportamiento frente a la corrosión y biocompatibilidad in vitro/in vivo de la aleación AZ31 modificada superficialmente

OpenAIRE

Escudero, M. L.; Clemente, C.; Rubio, J. C.; Alobera, M. A.; García-Alonso, M. C.; del Valle, J. A.; Iglesias, C.; Pérez-Maceda, B. T.; Carboneras, M.; Lozano, R. M.

2011-01-01

The present work evaluates the corrosion behaviour and the in vitro/in vivo biocompatibility of the AZ31 magnesium alloy, which fulfills the mechanical requirements of bone. The corrosion kinetic of as-received AZ31 alloy was not compatible with the cell growth. To improve its performance, the AZ31 alloy was surface modified by a chemical conversion treatment in hydrofluoric acid. The magnesium fluoride layer generated by the surface treatment of AZ31 alloy enhances its corrosion behaviour, a...

Microstructure investigation and first-principle analysis of die-cast AZ91 alloy with calcium addition

International Nuclear Information System (INIS)

Lin, L.; Wang, F.; Yang, L.; Chen, L.J.; Liu, Z.; Wang, Y.M.

2011-01-01

Highlights: → Die-cast AZ91 with Ca addition was investigated experimentally and theoretically. → Precipitation sequence was confirmed with increasing Ca addition. → Phase stability difference was verified by first-principle calculation. → Valence configurations were associated with alloying effects of Al, Mg and Ca. - Abstract: In order to get improved mechanical properties of die-cast AZ91 alloy under elevated temperatures, Ca element was added as a cost-effective alloying constituent. It appeared that minor Ca addition less than 0.5 wt% would result in no apparent change in microstructure, but the tensile strength at elevated temperatures was improved considerably. When increasing Ca addition to more than 1.0 wt%, Al 2 Ca phase will precipitate during solidification, no Mg 2 Ca phase was discovered. Homogeneous microstructure and high temperature stability in tensile strength of die-cast AZ91 alloy with Ca addition was mainly attributed to the precipitation of Al 2 Ca phase, which considerably refined the bulky β-Mg 17 Al 12 phase distributed originally at the grain boundaries of die-cast AZ91 alloy with no Ca addition. The priority of Al 2 Ca phase compared to Mg 2 Ca phase in precipitation sequence was verified by first-principle calculation of their cohesive energy and formation enthalpy, and can also be associated with more bounding electrons between Al and Ca atoms.

41 CFR 101-4.140 - Dissemination of policy.

Science.gov (United States)

2010-07-01

... EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Introduction § 101-4.140... 41 Public Contracts and Property Management 2 2010-07-01 2010-07-01 true Dissemination of policy. 101-4.140 Section 101-4.140 Public Contracts and Property Management Federal Property Management...

Elección de fluidos en el periodo perioperatorio del trasplante renal

OpenAIRE

Alejandro Gonzalez-Castro; María Ortiz-Lasa; Yhivian Peñasco; Camilo González; Carmen Blanco; Juan Carlos Rodriguez-Borregan

2017-01-01

El suero salino normal (SSN) ha sido clásicamente el fluido de resucitación elegido en el periodo perioperatorio del trasplante renal frente a aquellas soluciones balanceadas con potasio. Sin embargo, los problemas derivados de la hipercloremia desencadenada por la infusión de SSN han llevado a la realización de estudios que comparaban esta solución con los fluidos equilibrados. Mediante la presente revisión narrativa se deduce que el uso de cristaloides balanceados con contenido de potasio e...

17 CFR 140.1 - Headquarters office.

Science.gov (United States)

2010-04-01

... 17 Commodity and Securities Exchanges 1 2010-04-01 2010-04-01 false Headquarters office. 140.1..., FUNCTIONS, AND PROCEDURES OF THE COMMISSION Organization § 140.1 Headquarters office. (a) General. The headquarters office of the Commission is located at Three Lafayette Centre, 1155 21st Street, NW., Washington...

23 CFR 140.609 - Progress and final vouchers.

Science.gov (United States)

2010-04-01

... 23 Highways 1 2010-04-01 2010-04-01 false Progress and final vouchers. 140.609 Section 140.609 Highways FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION PAYMENT PROCEDURES REIMBURSEMENT Reimbursement for Bond Issue Projects § 140.609 Progress and final vouchers. (a) Progress vouchers may be...

40 CFR 45.140 - Budget and project period.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Budget and project period. 45.140 Section 45.140 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GRANTS AND OTHER FEDERAL ASSISTANCE TRAINING ASSISTANCE § 45.140 Budget and project period. The budget and project periods for...

27 CFR 27.140 - Certification requirements for wine.

Science.gov (United States)

2010-04-01

... for wine. 27.140 Section 27.140 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS IMPORTATION OF DISTILLED SPIRITS, WINES, AND BEER Importer's Records and Reports Other Records § 27.140 Certification requirements for wine. (a) Definitions...

Evaluation of AY/AZ tank farm ventilation system during aging waste retrieval operations

International Nuclear Information System (INIS)

Wong, J.J.; Waters, E.D.

1995-01-01

Waste Management is currently planning to demonstrate mobilization of radioactive waste sludges in Tank 101-AZ beginning in October 1991. The retrieval system being designed will utilize mixer pumps that generate high-velocity, high-volume submerged liquid jets to mobilize settled solids. There is concern that these jets may also generate radioactive aerosols, some of which may be carried into the tank Ventilation system. The purpose of this study is to determine if the current AY/AZ ventilation system or the proposed ventilation system upgrade (Project W-030) will provide adequate deentrainment of liquid and solid aerosols during mixer pump operations, or if the radioactive aerosols will overload the HEPA filters

21 CFR 189.140 - Diethylpyrocarbonate (DEPC).

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Diethylpyrocarbonate (DEPC). 189.140 Section 189.140 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... alcoholic and nonalcoholic beverages. (b) Food containing any added or detectable level of DEPC is deemed to...

41 CFR 51-10.140 - Employment.

Science.gov (United States)

2010-07-01

... 41 Public Contracts and Property Management 1 2010-07-01 2010-07-01 true Employment. 51-10.140... WHO ARE BLIND OR SEVERELY DISABLED § 51-10.140 Employment. No qualified handicapped person shall, on the basis of handicap, be subjected to discrimination in employment under any program or activity...

Ion exchange separation of carrier-free 140Ba and 140La from their equilibrium mixture using nitrilotriacetic acid and ascorbic acid as eluents

International Nuclear Information System (INIS)

Das, N.R.; Bhattacharyya, S.N.

1982-01-01

A simple cation exchange procedure for separation of 140 Ba- 140 La using Dowex 50W-X8 and nitrilotriacetic acid or ascorbic acid as the eluent has been described. The optimal separation of the daughter from the parent has been achieved using a 4% Na-nitrilotriacetate or Na-ascorbate solution at pH 7. The parent, 140 Ba, left in the column can be eluted with dilute hydrochloric acid or it can be retained in the column for milking off the daughter, 140 La, when needed. The radiochemical purity of the separated isotopes, 140 Ba and 140 La, were verified by γ-ray spectrometry. (author)

Influence of The Arrangement of Materials and Microstructural Analysis During FSW of AZ80A

Directory of Open Access Journals (Sweden)

Sevvel P.

2017-09-01

Full Text Available The main objective of this paper is to produce defect free weldments with improved properties during friction stir welding of dissimilar Mg alloys. The influence of the anisotropic arrangement of materials when AZ80A Mg alloy is taken as advancing side and AZ91C Mg alloy as retreating side and vice versa with respect to their mechanical properties and microstructural characteristics were investigated. The effects of various FSW parameters on the quality of these joints were also analyzed and best optimized FSW parameters were suggested. Defect free sound joints with excellent mechanical properties were produced when AZ80A Mg alloy was positioned at retreating side. At the same time, it seems a little bit difficult to obtain good quality joints with the contrary arrangement of materials. These investigations revealed that materials having inferior plastic deformability must be kept at the advancing side to obtain sound joints during FSW of dissimilar alloys of Magnesium.

A study of the deformation and failure mechanisms of protective intermetallic coatings on AZ91 Mg alloys using microcantilever bending

Energy Technology Data Exchange (ETDEWEB)

Lu, Mingyuan; Mead, James; Wu, Yueqin; Russell, Hugh; Huang, Han, E-mail: han.huang@uq.edu.au

2016-10-15

In this study, a nanoindentation-based microcantilever bending technique was utilized to investigate the interfacial properties of a β-Mg{sub 17}Al{sub 12}/AZ91 Mg alloy film/substrate system under tensile loading conditions. Finite element analysis (FEA) was first undertaken to optimise the design of cantilever structures for inducing high tensile stresses at the interface. Cantilevers consisting of a necked region or notch at the interface were determined to be the most successful designs. Microcantilevers containing the β-Mg{sub 17}Al{sub 12}/AZ91 interface were then made using focused ion beam (FIB) milling technique. Necks were made in the cantilevers to intensify the tension at the interface and notches were used to introduce a stress concentration to the interface. During bending, the cantilevers were deflected to failure. Subsequent analysis of the deformed cantilevers using electron microscopies revealed that plastic deformation, and subsequent ductile rupture, of the AZ91 phase was the dominant failure mechanism. When the β-Mg{sub 17}Al{sub 12}/AZ91 film/substrate system was subjected to tension, the softer AZ91 phase failed prior to interfacial delamination, demonstrating that the strength of the interface exceeded the stresses that caused ductile failure in the substrate material. - Highlights: •Microcantilever bending was used to study the property of film/substrate interface. •FEA was used to optimise cantilever design for achieving high interfacial tension. •The intermetallic coatings on AZ91 substrate have strong interfacial adhesion.

25 CFR 140.26 - Infectious plants.

Science.gov (United States)

2010-04-01

... 25 Indians 1 2010-04-01 2010-04-01 false Infectious plants. 140.26 Section 140.26 Indians BUREAU... Infectious plants. Traders shall not introduce into, sell, or spread within Indian reservations any plant, plant product, seed, or any type of vegetation, which is infested, or infected or which might act as a...

25 CFR 140.1 - Sole power to appoint.

Science.gov (United States)

2010-04-01

... 25 Indians 1 2010-04-01 2010-04-01 false Sole power to appoint. 140.1 Section 140.1 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR FINANCIAL ACTIVITIES LICENSED INDIAN TRADERS § 140.1 Sole power to appoint. The Commissioner of Indian Affairs shall have the sole power and authority to...

Facebook Marketing - Fra A-Z

DEFF Research Database (Denmark)

Mortensen, Thomas Bøtker

2009-01-01

Facebook Marketing – Leverage Social Media to Grow Your Business af Steven Holzner er Facebook Marketing fra A-Z, som kan anbefales til virksomheder, som overvejer at bevæge sig ud i cyber space og afprøve mulighederne for at markedsføre sig dér. Bogen beskriver på hvilke væsentlige punkter...... marketing på Facebook adskiller sig fra traditionel marketing, og gennemgår trin for trin de fundamentale ting, som man skal vide for, at virksomheden kan agere med den tilsigtede effekt i et socialt netværk som Facebook. Og eftersom 34 % af den danske befolkning i dag er hoppet med på Facebook vognen og...... har oprettet en profil på Facebook, er potentialet åbenlyst....

EnviroAtlas - Phoenix, AZ - Meter-Scale Urban Land Cover (MULC) Data (2010)

Data.gov (United States)

U.S. Environmental Protection Agency — The EnviroAtlas Phoenix, AZ Meter-Scale Urban Land Cover (MULC) data and map were generated from USDA NAIP (National Agricultural Imagery Program) four band (red,...

Stamping of Thin-Walled Structural Components with Magnesium Alloy AZ31 Sheets

International Nuclear Information System (INIS)

Chen, F.-K.; Chang, C.-K.

2005-01-01

In the present study, the stamping process for manufacturing cell phone cases with magnesium alloy AZ31 sheets was studied using both the experimental approach and the finite element analysis. In order to determine the proper forming temperature and set up a fracture criterion, tensile tests and forming limit tests were first conducted to obtain the mechanical behaviors of AZ31 sheets at various elevated temperatures. The mechanical properties of Z31 sheets obtained from the experiments were then adopted in the finite element analysis to investigate the effects of the process parameters on the formability of the stamping process of cell phone cases. The finite element simulation results revealed that both the fracture and wrinkle defects could not be eliminated at the same time by adjusting blank-holder force or blank size. A drawbead design was then performed using the finite element simulations to determine the size and the location of drawbead required to suppress the wrinkle defect. An optimum stamping process, including die geometry, forming temperature, and blank dimension, was then determined for manufacturing the cell phone cases. The finite element analysis was validated by the good agreement between the simulation results and the experimental data. It confirms that the cell phone cases can be produced with magnesium alloy AZ31 sheet by the stamping process at elevated temperatures

46 CFR 133.140 - Stowage of rescue boats.

Science.gov (United States)

2010-10-01

... SYSTEMS Requirements for All OSVs § 133.140 Stowage of rescue boats. (a) Rescue boats must be stowed as follows: (1) Each rescue boat must be ready for launching in not more than 5 minutes. (2) Each rescue boat... 46 Shipping 4 2010-10-01 2010-10-01 false Stowage of rescue boats. 133.140 Section 133.140...

Histone variant H2A.Z antagonizes the positive effect of the transcriptional activator CPC1 to regulate catalase-3 expression under normal and oxidative stress conditions.

Science.gov (United States)

Dong, Qing; Wang, Yajun; Qi, Shaohua; Gai, Kexin; He, Qun; Wang, Ying

2018-05-05

In eukaryotes, deposition of the histone variant H2A.Z into nucleosomes through the chromatin remodeling complex, SWR1, is a crucial step in modulating gene transcription. Recently, H2A.Z has been shown to control the expression of responsive genes, but the underlying mechanism of how H2A.Z responds to physiological stimuli is not well understood. Here, we reveal that, in Neurospora crassa, H2A.Z is a negative regulator of catalase-3 gene, which is responsible for resistance to oxidative stress. H2A.Z represses cat-3 gene expression through direct incorporation at cat-3 locus in a SWR1 complex dependent pathway. Notably, loss of H2A.Z or SWR1 subunits leads to increased binding of a transcription factor, CPC1, at cat-3 locus. Additionally, introduction of plasmids containing gene encoding H2A.Z or SWR1 complex subunits into wild-type strains decreased CAT-3 expression, indicating that H2A.Z counteracts the positive effect of CPC1 to achieve low level cat-3 expression under non-inductive condition. Furthermore, upon oxidative stress, H2A.Z is rapidly evicted from cat-3 locus for the recruitment of CPC1, resulting in robust and full cat-3 gene expression in response to external stimuli. Collectively, this study strongly demonstrates that H2A.Z antagonizes the function of transcription factor to regulate responsive gene transcription under normal conditions and to poise for gene full activation under oxidative stress. Copyright © 2018. Published by Elsevier Inc.

Friction stir welded AM50 and AZ31 Mg alloys: Microstructural evolution and improved corrosion resistance

Energy Technology Data Exchange (ETDEWEB)

Templeman, Yael [Department of Materials Engineering, Ben Gurion University of the Negev, PO Box 653, Beer Sheva 84105 (Israel); Ben Hamu, Guy [Department of Mechanical Engineering, Sami Shamoon College of Engineering, Ashdod 77245 (Israel); Meshi, Louisa, E-mail: Louisa@bgu.ac.il [Department of Materials Engineering, Ben Gurion University of the Negev, PO Box 653, Beer Sheva 84105 (Israel)

2017-04-15

One of the major drawbacks of Mg alloys is poor weldability, caused by porosity formation during conventional fusion welding processes. Friction Stir Welding (FSW) is promising technique in this context since it is a solid state technique. Contradicting results were published in the literature regarding the FSWed Mg alloys joint's properties. Current research was performed in order to investigate the microstructure and corrosion properties of FSWed Mg alloys, studying representatives of two commercial families: wrought AZ31-H24 and die cast AM50. It was found that in both alloys recrystallization occurred during the FSW. In AM50 the mechanism of the recrystallization was continuous, manifested by dislocation rearrangement into sub grain boundaries. In AZ31 discontinuous recrystallization had occurred through grain boundaries migration - twins rotated with respect to the matrix, turning into low angle grain boundaries. Corrosion resistance has improved during the FSW in both alloys to different extents. In the AM50 alloy, the nugget exhibited significantly higher surface potential than the base metal mainly due to the higher Al concentration in the matrix of the nugget, resulting from the dissolution of Al-enrichment and β-Mg{sub 17}Al{sub 12} phase. In the AZ31 alloy, no change in Al concentration had occurred, and the surface potential measured in the nugget was only slightly higher than in the base metal. These results underline the appropriateness of the FSW for Mg alloys since during the conventional welding deterioration of the corrosion resistance occurs. - Highlights: • Following FSW, AZ31-H24 experienced discontinuous recrystallization. • In AZ31 grain boundaries migration occurred, thus twins rotated. • In die cast AM50 continuous recrystallization occurred during the FSW. • In AM50 - dislocations rearranged into sub grain boundaries. • Corrosion resistance has improved during the FSW in both alloys to different extent.

Friction stir welded AM50 and AZ31 Mg alloys: Microstructural evolution and improved corrosion resistance

International Nuclear Information System (INIS)

Templeman, Yael; Ben Hamu, Guy; Meshi, Louisa

2017-01-01

One of the major drawbacks of Mg alloys is poor weldability, caused by porosity formation during conventional fusion welding processes. Friction Stir Welding (FSW) is promising technique in this context since it is a solid state technique. Contradicting results were published in the literature regarding the FSWed Mg alloys joint's properties. Current research was performed in order to investigate the microstructure and corrosion properties of FSWed Mg alloys, studying representatives of two commercial families: wrought AZ31-H24 and die cast AM50. It was found that in both alloys recrystallization occurred during the FSW. In AM50 the mechanism of the recrystallization was continuous, manifested by dislocation rearrangement into sub grain boundaries. In AZ31 discontinuous recrystallization had occurred through grain boundaries migration - twins rotated with respect to the matrix, turning into low angle grain boundaries. Corrosion resistance has improved during the FSW in both alloys to different extents. In the AM50 alloy, the nugget exhibited significantly higher surface potential than the base metal mainly due to the higher Al concentration in the matrix of the nugget, resulting from the dissolution of Al-enrichment and β-Mg 17 Al 12 phase. In the AZ31 alloy, no change in Al concentration had occurred, and the surface potential measured in the nugget was only slightly higher than in the base metal. These results underline the appropriateness of the FSW for Mg alloys since during the conventional welding deterioration of the corrosion resistance occurs. - Highlights: • Following FSW, AZ31-H24 experienced discontinuous recrystallization. • In AZ31 grain boundaries migration occurred, thus twins rotated. • In die cast AM50 continuous recrystallization occurred during the FSW. • In AM50 - dislocations rearranged into sub grain boundaries. • Corrosion resistance has improved during the FSW in both alloys to different extent.

Alterações do desenvolvimento de crianças prematuras nascidas de mães com malária no periodo gestacional

OpenAIRE

Simões, Maria da Conceição Ribeiro

2012-01-01

Objetivo : O estudo buscou avaliar as alterações no desenvolvimento de crianças prematuras nascidas de mães com malária no periodo gestacional, em Porto Velho, Rondônia. O objetivo principal é descrever as alterações encontradas nessas crianças aplicando um teste preditivo para alterações no desenvolvimento e compará-las à um grupo controle de crianças prematuras nascidas de mães que não apresentaram malária no periodo gestacional. Métodos : Por ser um estudo do tipo transvers...

Tank 241-AZ-101 steam bumping and settling Process Test report

International Nuclear Information System (INIS)

Winkler, C.M.

1995-01-01

This report summarizes the process test in which the airlift circulators in Tank 241-AZ-101 were shutdown. The test was successful, in that no extreme temperature excursions occurred. Only general data was obtianed through the use of a gamma energy probe

Corrosion behavior of biodegradable material AZ31 coated with beeswax-colophony resin

Science.gov (United States)

Gumelar, Muhammad Dikdik; Putri, Nur Ajrina; Anggaravidya, Mahendra; Anawati, Anawati

2018-05-01

Magnesium (Mg) and its alloys are potential candidates for biodegradable implant materials owing to their ability to degrade spontaneously in a physiological environment. However, the degradation rate is still considered too fast in human body solution. A coating is typically applied to slowdown corrosion rate of Mg alloys. In this work, an organic coating of mixture beeswax-colophony with ratios of 40-60, 50-50, and 60-40 in wt% was synthesized and applied on commercial magnesium alloyAZ31. The coated specimens were then characterized with SEM and XRF. The corrosion behavior of the coated specimens was evaluated by immersion test in 0.9 wt% NaCl solution at 37°C for 14 days. The results indicated that the coating material improved the corrosion resistance of the AZ31 alloy.

Method of producing a solution of radioactive lanthanum-140 from radioactive barium-140 in an isotope generator and installation to carry out the method

International Nuclear Information System (INIS)

Akerman, K.; Jacobs, G.; Sauerwein, K.

1979-01-01

A method of separating radioactive lanthanum-140 from radioactive Ba-140 is proposed. The lanthanum-140 will be washed out of a sulphate precipitate and separated from Ba-140-sulphate by a granular filter mass of CaSO 4 and BaSO 4 . Details of the process are given. (UWI) [de

Effect of magnesium hydride on the corrosion behavior of an AZ91 magnesium alloy in sodium chloride solution

International Nuclear Information System (INIS)

Chen Jian; Dong Junhua; Wang Jianqiu; Han Enhou; Ke Wei

2008-01-01

The effect of magnesium hydride on the corrosion behavior of an as-cast AZ91 alloy in 3.5 wt.% NaCl solution was investigated using gas collection method and potentiostatic test. The Pourbaix diagram of Mg-H 2 O system was built using thermodynamic calculation. It was possible that magnesium hydride could form in the whole pH range in theory. The experimental results showed that at cathodic region, magnesium hydride formed on surface, which was the controlling process for the corrosion behavior of AZ91 alloy; at anodic region and free corrosion potential, magnesium hydride model and partially protective film model, monovalent magnesium ion model and particle undermining model were responsible for the corrosion process of AZ91 alloy

Role of Receptor-Interacting Protein 140 in human fat cells

Directory of Open Access Journals (Sweden)

Stenson Britta M

2010-01-01

Full Text Available Abstract Background Mice lacking Receptor-interacting protein 140 (RIP140 have reduced body fat which at least partly is mediated through increased lipid and glucose metabolism in adipose tissue. In humans, RIP140 is lower expressed in visceral white adipose tissue (WAT of obese versus lean subjects. We investigated the role of RIP140 in human subcutaneous WAT, which is the major fat depot of the body. Methods Messenger RNA levels of RIP140 were measured in samples of subcutaneous WAT from women with a wide variation in BMI and in different human WAT preparations. RIP140 mRNA was knocked down with siRNA in in vitro differentiated adipocytes and the impact on glucose transport and mRNA levels of target genes determined. Results RIP140 mRNA levels in subcutaneous WAT were decreased among obese compared to lean women and increased by weight-loss, but did not associate with mitochondrial DNA copy number. RIP140 expression increased during adipocyte differentiation in vitro and was higher in isolated adipocytes compared to corresponding pieces of WAT. Knock down of RIP140 increased basal glucose transport and mRNA levels of glucose transporter 4 and uncoupling protein-1. Conclusions Human RIP140 inhibits glucose uptake and the expression of genes promoting energy expenditure in the same fashion as the murine orthologue. Increased levels of human RIP140 in subcutaneous WAT of lean subjects may contribute to economize on energy stores. By contrast, the function and expression pattern does not support that RIP140 regulate human obesity.

Mechanical behaviour of biodegradable AZ31 magnesium alloy after long term in vitro degradation.

Science.gov (United States)

Adekanmbi, Isaiah; Mosher, Christopher Z; Lu, Helen H; Riehle, Mathis; Kubba, Haytham; Tanner, K Elizabeth

2017-08-01

Biodegradable magnesium alloys including AZ31 are exciting candidates for temporary implants as they eliminate the requirement for surgical removal, yet have higher mechanical properties than degradable polymers. However, the very long term mechanical properties and degradation of these alloys have not been fully characterized. The tensile, bending and corrosion behaviour of biodegradable AZ31 Mg alloy specimens have been investigated for up to 9months in vitro in phosphate buffered saline (PBS). Small AZ31 Mg specimens showed a significant drop in bend yield strength and modulus after 3months in vitro degradation and an average mass loss of 6.1%. Larger dumbbell specimens showed significant drops in tensile strength from 251.96±3.53MPa to 73.5±20.2MPa and to 6.43±0.9MPa and in modulus from 47.8±5.6GPa to 25.01±3.4GPa and 2.36±0.89GPa after 3 and 9months respectively. These reductions were accompanied by an average mass loss of 18.3% in 9months. Degradation rate for the small and large specimens followed similar profiles with immersion time, with peak degradation rates of 0.1747gm -2 h - 1 and 0.0881gm -2 h - 1 , and average rates of 0.1038gm -2 h - 1 and 0.0397gm -2 h - 1 respectively. SEM fractography and polished specimen cross-sections revealed corrosion pits, cracks and corrosion induced defects. These data indicate the potential of AZ31 Mg for use in implants that require medium term degradation with load bearing mechanical properties. Copyright © 2017 Elsevier B.V. All rights reserved.

Influence of boron addition on the grain refinement and mechanical properties of AZ91 Mg alloy

International Nuclear Information System (INIS)

Suresh, M.; Srinivasan, A.; Ravi, K.R.; Pillai, U.T.S.; Pai, B.C.

2009-01-01

This article reports the effect of boron addition on the grain refinement efficiency and mechanical properties of AZ91 magnesium alloy. The results show that the addition of boron in the form of Al-4B master alloy, significantly refines the grain size of AZ91 alloy. This refinement is due to the presence of AlB 2 particles, which act as potential nucleants for Mg grains. Improved mechanical properties are obtained with the addition of boron due to the finer grains.

Structural evaluation of thermocouple probes for 241-AZ-101 waste tank

International Nuclear Information System (INIS)

Kanjilal, S.K.

1994-01-01

This document reports on the structural analysis of the thermocouple probe to be installed in 241-AZ-101 waste tank. The thermocouple probe is analyzed for normal pump mixing operation and potential earthquake induced loads required by the Hanford Site Design Criteria SDC-4.1

Structural evaluation of thermocouple probes for 241-AZ-101 waste tank

Energy Technology Data Exchange (ETDEWEB)

Kanjilal, S.K.

1994-12-06

This document reports on the structural analysis of the thermocouple probe to be installed in 241-AZ-101 waste tank. The thermocouple probe is analyzed for normal pump mixing operation and potential earthquake induced loads required by the Hanford Site Design Criteria SDC-4.1.

Conformal, planarizing and bridging AZ5214-E layers deposited by a 'draping' technique on non-planar III V substrates

Science.gov (United States)

Eliás, P.; Strichovanec, P.; Kostic, I.; Novák, J.

2006-12-01

A draping technique was tested for the deposition of positive-tone AZ5214-E photo-resist layers on non-planar (1 0 0)-oriented III-V substrates, which had a variety of three-dimensional (3D) topographies micromachined in them that consisted, e.g., of mesa ridges confined to side facets with variable tilt, inverted pyramidal holes and stubs confined to perpendicular side facets. All objects were sharp-edged. In each draping experiment, an AZ5214-E sheet was (1) formed floating on the water surface, (2) lowered onto a non-planar substrate and (3) draped over it during drying to form either self-sustained, or conformal, or planarizing layers over the non-planar substrates. The draping process is based on the depression of the glass transition temperature Tg of AZ5214-E material induced by penetrant water molecules that interact with AZ5214-E. During the process, the molecules are initially trapped under an AZ5214-E sheet and then transported out through the sheet via permeation. The water-AZ5214-E interaction modifies the stiffness κ of the sheet. The magnitude of the effect depends on temperature T and on partial water vapour pressure difference p(T, P, κ): the net effect is that Tg = f(C(T, P), p(T, P, κ)) is lowered as the concentration C of water increases with T and p, where P is the permeability of the sheet. The interaction depressed the Tg of the sheets as low as or lower than 53 °C for 6 µm thick sheets. At room temperature T Tg, the sheet becomes rubbery and mouldable by adhesion and capillary forces. As a result, it can either contour or planarize the topography depending on its geometry and thickness of the sheet.

Structure of the AZ91 alloy pressure castings fabricated of home scrap containing charge

Directory of Open Access Journals (Sweden)

Z. Konopka

2011-04-01

Full Text Available The influence of the AZ91 alloy home scrap addition to the metal charge on both the structure and the selected mechanical propertiesof pressure castings was examined in this article. Two heats were made using different components, the first with only pure AZ91 alloyingots in the charge, and the second containing 30 wt % of home scrap. The hot chamber 3 MN machine was used for casting. Thestructures of the castings and their Brinell hardness were examined for both cases. A strong refinement of crystals was observed in castings made with the contribution of the recycled material. Any significant differences in castings hardness were not observed.

Influence of Zeolite Coating on the Corrosion Resistance of AZ91D Magnesium Alloy.

Science.gov (United States)

Banerjee, P Chakraborty; Woo, Ren Ping; Grayson, Sam Matthew; Majumder, Amrita; Raman, R K Singh

2014-08-22

The protective performance of zeolite coating on AZ91D magnesium alloy was evaluated using potentiodynamic polarisation and electrochemical impedance spectroscopy (EIS) in 0.1 M sodium chloride solution (NaCl). Electrical equivalent circuit (EEC) was developed based upon hypothetical corrosion mechanisms and simulated to correspond to the experimental data. The morphology and the chemical nature of the coating were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD) analysis. Post corrosion morphologies of the zeolite coated and the uncoated AZ91D alloy were investigated using SEM. The corrosion resistance of the zeolite coated specimen was at least one order of magnitude higher than the uncoated specimen.

9 CFR 381.140 - Relabeling poultry products.

Science.gov (United States)

2010-01-01

... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Relabeling poultry products. 381.140... AGENCY ORGANIZATION AND TERMINOLOGY; MANDATORY MEAT AND POULTRY PRODUCTS INSPECTION AND VOLUNTARY INSPECTION AND CERTIFICATION POULTRY PRODUCTS INSPECTION REGULATIONS Labeling and Containers § 381.140...

Corrosion characterization of micro-arc oxidization composite electrophoretic coating on AZ31B magnesium alloy

Energy Technology Data Exchange (ETDEWEB)

Wang, Congjie [School of Materials Science and Engineering, Xi’an University of Technology, Xi’an 710048 (China); Jiang, Bailing [School of Materials Science and Engineering, Nanjing Tech University, Nanjing 211816 (China); Liu, Ming [General Motors China Science Lab, Shanghai 201206 (China); Ge, Yanfeng [School of Materials Science and Engineering, Xi’an University of Technology, Xi’an 710048 (China)

2015-02-05

Highlights: • A new protective composite coatings were prepared on AZ31B Mg alloy. • The E-coat locked into MAO coat by discharge channels forming a smoother and compact surface without defects. • Comparing with MAO coat, the MAOE composite coat could provide an excellent barrier for bare Mg against corrosion attack. - Abstract: A two layer composite coating system was applied on the surface of AZ31B magnesium alloy by Micro-arc Oxidation (MAO) plus electrophoretic coat (E-coat) technique. The Mg sample coated with MAO plus E-coat (MAOE) was compared with bare Mg and Mg sample coated by MAO only. The surface microstructure and cross section of bare and coated Mg before and after corrosion were examined by Scanning Electron Microscopy (SEM). The corrosion performance of bare and coated Mg was evaluated using electrochemical measurement and hydrogen evolution test. The results indicated that the corrosion resistance of AZ31B Mg alloy was significantly improved by MAOE composite coating. The corrosion mechanism of bare and coated Mg is discussed.

Influence of heat treatment on the machinability and corrosion behavior of AZ91 Mg alloy

Directory of Open Access Journals (Sweden)

Swetha Chowdary V

2018-03-01

Full Text Available In the present study, AZ91 Mg alloy was heat treated at 410 °C for 6, 12 and 24 h to investigate the influence of heat treatment on machinability and corrosion behavior. The effect of soaking time on the amount and distribution of Mg17Al12 (β – phase was analyzed under the optical microscope. Microhardness measurements demonstrated the increased hardness with increased heat treatment soaking time, which can be attributed to the solid solution strengthening. The influence of super saturated α-grains on reducing the cutting force (Fz with respect to increased cutting speed was observed as prominent. The corrosion behavior of the heat treated specimens was studied by conducting electrochemical tests. Surprisingly, corrosion rate of heat treated samples was observed as increased compared with the base material. From the results, it is evident that the machinability of AZ91 Mg alloy can be improved by producing super saturated α-grains through heat treatment but at the cost of losing corrosion resistance. Keywords: AZ91 Mg alloy, Solid solution, Turning, Corrosion, Machinability

AZ-2000-IECW and StaMet Black Kapton Options for Solar Probe Plus MAG Sensor MLI Kevlar/Polyimide Shells

Science.gov (United States)

Choi, Michael K.

2017-01-01

AZ-2000-IECW white paint and StaMet black Kapton have been evaluated for the Kevlar/polyimide shells that enclose the Solar Probe Plus Magnetometer (MAG) sensors and multilayer insulation. Flight qualification testing on AZ-2000-IECW painted Kevlar/polyimide laminate was completed at Goddard Space Flight Center. This paint potentially meets all the requirements. However, it has no flight heritage. StaMet is hotter in the sun, and is specular. The results of the MAG thermal balance test show StaMet meets the thermal requirement and heater power budget. The mission prefers to fly StaMet after evaluating the risks of AZ-2000-IECW flaking and glint from StaMet to the Star Trackers.

Mapping of p140Cap phosphorylation sites

DEFF Research Database (Denmark)

Repetto, Daniele; Aramu, Simona; Boeri Erba, Elisabetta

2013-01-01

phosphorylation and tunes its interactions with other regulatory molecules via post-translation modification. In this work, using mass spectrometry, we found that p140Cap is in vivo phosphorylated on tyrosine (Y) within the peptide GEGLpYADPYGLLHEGR (from now on referred to as EGLYA) as well as on three serine...... residues. Consistently, EGLYA has the highest score of in silico prediction of p140Cap phosphorylation. To further investigate the p140Cap function, we performed site specific mutagenesis on tyrosines inserted in EGLYA and EPLYA, a second sequence with the same highest score of phosphorylation. The mutant...

Test-retest reliability of [{sup 11}C]AZ10419369 binding to 5-HT{sub 1B} receptors in human brain

Energy Technology Data Exchange (ETDEWEB)

Nord, Magdalena; Finnema, Sjoerd J.; Schain, Martin; Halldin, Christer; Farde, Lars [Karolinska Institutet, Center for Psychiatric Research, R5:00, Karolinska University Hospital, Department of Clinical Neuroscience, Stockholm (Sweden)

2014-02-15

[{sup 11}C]AZ10419369 is a recently developed 5-HT{sub 1B} receptor radioligand that is sensitive to changes in endogenous serotonin concentrations in the primate brain. Thus, [{sup 11}C] AZ10419369 may serve as a useful tool in clinical studies of the pathophysiology and pharmacological treatment of diseases related to the serotonin system, such as depression and anxiety disorders. The aim of this study was to evaluate the test-retest reliability of [{sup 11}C]AZ10419369. Eight men were examined with PET and [{sup 11}C] AZ10419369 twice on the same day. The binding potentials (BP{sub ND}) of [{sup 11}C]AZ10419369 in selected serotonergic projection areas and in the raphe nuclei (RN) were determined using the simplified reference tissue model, and for comparison also using a wavelet-aided parametric imaging approach. The BP{sub ND} values obtained from the first and second PET scans were compared by means of descriptive statistics, difference, absolute variability and intraclass correlation coefficient. Similar BP{sub ND} values were obtained with the two methods. The absolute mean differences in BP{sub ND} between PET 1 and PET 2 were less than 3 % in all serotonergic projection regions. Absolute variabilities were low in cortical regions (5 - 7 %), low to moderate (7 - 14 %) in subcortical regions, but higher (20 %) in the RN. The BP{sub ND} of [{sup 11}C]AZ10419369 is highly reproducible in cortical regions and satisfactory in subcortical projection areas. The variability in the RN is higher. Thus larger sample sizes or larger divergences are required to assess a potential difference between subjects or between experimental conditions in this region. (orig.)

Nano grained AZ31 alloy achieved by equal channel angular rolling process

International Nuclear Information System (INIS)

Hassani, F.Z.; Ketabchi, M.

2011-01-01

Equal channel angular rolling (ECAR) is a severe plastic deformation process which is carried out on large, thin sheets. The grain size could be significantly decreased by this process. The main purpose of this study is to investigate the possibility of grain refinement of AZ31 magnesium alloy sheet by this process to nanometer. The effect of the number of ECAR passes on texture evolution of AZ31 magnesium alloy was investigated. ECAR temperature was controlled to maximize the grain refinement efficiency along with preventing cracking. The initial microstructure of as-received AZ31 sheet showed an average grain size of about 21 μm. The amount of grain refinement increased with increasing the pass number. After 10 passes of the process, significant grain refinement occurred and the field emission scanning electron microscopic (FESEM) micrographs showed that the size of grains were decreased significantly to about 14-70 nm. These grains were formed at the grain boundaries and inside some of the previous larger micrometer grains. Observation of optical microstructures and X-ray diffraction patterns (XRD) showed the formation of twins after ECAR process. Micro-hardness of material was studied at room temperature. There was a continuous enhancement of hardness by increasing the pass number of ECAR process. At the 8th pass, hardness values increased by 53%. At final passes hardness reduced slightly, which was attributed to saturation of strain in high number of passes.

Diffusion and solubility of Au implanted into the AZ1350 photoresist

International Nuclear Information System (INIS)

Soares, M.R.F.; Kaschny, J.R.A.; Santos, J.H.R. dos; Amaral, L.; Behar, M.; Fink, D.

2000-01-01

In the present paper we report diffusion and solubility results for Au into the photoresist AZ1350. Au was implanted into AZ1350 films at very low energy (E=20 keV) and fluences (PHI=10 12 and 5x10 12 Au/cm 2 ). In this way the radiation damage introduced by the implantation process was minimized and cluster formation was avoided. Annealing was performed in the 150-300 deg. C temperature range and the as implanted and thermal treated samples were analyzed using the Rutherford backscattering (RBS) technique. For the lowest implantation fluence the results have shown a regular atomic diffusion process characterized by an activation energy of E a =640 meV. Instead, for PHI=5x10 12 Au/cm 2 the diffusional mechanism has revealed the effects of the radiation damage. In addition solubility measurements indicate that the solubility limit at 250 deg. C is of the order 0.3 at.%

Effects of organic acid pickling on the corrosion resistance of magnesium alloy AZ31 sheet

DEFF Research Database (Denmark)

Nwaogu, Ugochukwu Chibuzoh; Blawert, C.; Scharnagl, N.

2010-01-01

mu m of the contaminated surface was required to reach corrosion rates less than 1 mm/year in salt spray condition. Among the three organic acids examined, acetic acid is the best choice. Oxalic acid can be an alternative while citric acid is not suitable for cleaning AZ31 sheet, because......Organic acids were used to clean AZ31 magnesium alloy sheet and the effect of the cleaning processes on the surface condition and corrosion performance of the alloy was investigated. Organic acid cleanings reduced the surface impurities and enhanced the corrosion resistance. Removal of at least 4...

El cine musical clásico en Estados Unidos (1927-1960) y su repercusión en los medios audiovisuales posteriores a este periodo

OpenAIRE

Andrés Bailón, Sergio de

2013-01-01

[ES] Estudio de los estilos musicales y la funcionalidad de los números musicales en el contexto del cine musical americano del periodo comprendido entre 1927 y 1960, así como la repercusión de dichos elementos estilísticos y estructurales en creaciones Estudio de los estilos musicales y la funcionalidad de los números musicales en el contexto del cine musical americano del periodo comprendido entre 1927 y 1960, así como la repercusión de dichos elementos estilísticos y estructurales en creac...

9 CFR 3.140 - Care in transit.

Science.gov (United States)

2010-01-01

... Warmblooded Animals Other Than Dogs, Cats, Rabbits, Hamsters, Guinea Pigs, Nonhuman Primates, and Marine... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Care in transit. 3.140 Section 3.140 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE ANIMAL...

31 CFR 28.140 - Dissemination of policy.

Science.gov (United States)

2010-07-01

... 31 Money and Finance: Treasury 1 2010-07-01 2010-07-01 false Dissemination of policy. 28.140 Section 28.140 Money and Finance: Treasury Office of the Secretary of the Treasury NONDISCRIMINATION ON... elementary and secondary school students, employees, sources of referral of applicants for admission and...

7 CFR 1.140 - Conferences and procedure.

Science.gov (United States)

2010-01-01

... 7 Agriculture 1 2010-01-01 2010-01-01 false Conferences and procedure. 1.140 Section 1.140 Agriculture Office of the Secretary of Agriculture ADMINISTRATIVE REGULATIONS Rules of Practice Governing...) An outline of the case or defense; (ii) The legal theories upon which the party will rely; (iii...

Cantidad y calidad de información de riesgos divulgada por las empresas españolas: Un análisis en periodos diferentes del ciclo económico

Directory of Open Access Journals (Sweden)

J. David Cabedo Semper

2016-07-01

Full Text Available La obligación de las empresas de informar en los estados financieros de los riesgos a los que se enfrentan ha dado lugar a la aparición de una emergente línea de investigación sobre el grado de divulgación de información sobre riesgos y de su calidad. En este sentido, el presente trabajo analiza la cantidad y la calidad de la información de riesgos para 2 periodos diferentes de ciclo económico: un periodo de bonanza económica (2006 y un periodo de crisis (2011. El estudio se realiza para el caso español utilizando empresas que cotizaban en el mercado continuo durante los años 2006 y 2011. Los resultados evidencian que las empresas presentan un mayor volumen de información sobre riesgos en el periodo de crisis, mientras que este aumento no se corresponde con un mayor grado de calidad de dicha información. Este mayor nivel de información de riesgos se debe a los riesgos financieros, sin detectar aumentos estadísticamente significativos en información de riesgos no financieros.

Loss of mechanical properties in vivo and bone-implant interface strength of AZ31B magnesium alloy screws with Si-containing coating.

Science.gov (United States)

Tan, Lili; Wang, Qiang; Lin, Xiao; Wan, Peng; Zhang, Guangdao; Zhang, Qiang; Yang, Ke

2014-05-01

In this study the loss of mechanical properties and the interface strength of coated AZ31B magnesium alloy (a magnesium-aluminum alloy) screws with surrounding host tissues were investigated and compared with non-coated AZ31B, degradable polymer and biostable titanium alloy screws in a rabbit animal model after 1, 4, 12 and 21weeks of implantation. The interface strength was evaluated in terms of the extraction torque required to back out the screws. The loss of mechanical properties over time was indicated by one-point bending load loss of the screws after these were extracted at different times. AZ31B samples with a silicon-containing coating had a decreased degradation rate and improved biological properties. The extraction torque of Ti6Al4V, poly-l-lactide (PLLA) and coated AZ31B increased significantly from 1week to 4weeks post-implantation, indicating a rapid osteosynthesis process over 3weeks. The extraction torque of coated AZ31B increased with implantation time, and was higher than that of PLLA after 4weeks of implantation, equalling that of Ti6Al4V at 12weeks and was higher at 21weeks. The bending loads of non-coated AZ31B and PLLA screws degraded sharply after implantation, and that of coated AZ31B degraded more slowly. The biodegradation mechanism, the coating to control the degradation rate and the bioactivity of magnesium alloys influencing the mechanical properties loss over time and bone-implant interface strength are discussed in this study and it is concluded that a suitable degradation rate will result in an improvement in the mechanical performance of magnesium alloys, making them more suitable for clinical application. Copyright © 2013 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Estructura administrativa de la Provincia de Bogotá durante el periodo comprendido entre 1832- 1857

OpenAIRE

Restrepo Robledo, Luz Marina

2010-01-01

El estudio de la estructura administrativa de la provincia de Bogotá en el siglo IX es importante por cuanto se muestra por primera vez cuales fueron los primeros entes administrativos que se crearon durante este periodo, fundamentalmente durante la vigencia de la constitución de 1832. El régimen territorial de las provincias se dividió a su vez en cantones y éstos, en distritos parroquiales.

STIS E140M Sensitivity Curves

Science.gov (United States)

Monroe, TalaWanda R.

2017-08-01

The spectrophotometric white dwarf G191-B2B will be observed with the E140M grating to obtain an updated set of sensitivity curves for this highly used mode. Spectroscopic sensitivity monitoring observations of BD+284211 have shown that the blaze function shapes have changed since SM4 and now limit the relative photometric flux accuracy of 14 of 43 E140M spectral orders to 5-10% at the edges. The blaze function shape changes have hindered attempts to determine the post-SM4 temporal blaze function shifts for this grating. Given the popularity of this unique FUV mode, with almost full simultaneous coverage of 1144 to 1710 A in a single observation, and consideration of the STIS archival legacy, we request 1 orbit to re-observe G191-B2B with the E140/1425 setting.

40 CFR 96.140 - State trading budgets.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 20 2010-07-01 2010-07-01 false State trading budgets. 96.140 Section...) NOX BUDGET TRADING PROGRAM AND CAIR NOX AND SO2 TRADING PROGRAMS FOR STATE IMPLEMENTATION PLANS CAIR NOX Allowance Allocations § 96.140 State trading budgets. The State trading budgets for annual...

Effect of Mucin and Bicarbonate Ion on Corrosion Behavior of AZ31 Magnesium Alloy for Airway Stents.

Science.gov (United States)

Jang, Yongseok; Owuor, Daniel; Waterman, Jenora T; White, Leon; Collins, Boyce; Sankar, Jagannathan; Gilbert, Thomas W; Yun, Yeoheung

2014-08-15

The biodegradable ability of magnesium alloys is an attractive feature for tracheal stents since they can be absorbed by the body through gradual degradation after healing of the airway structure, which can reduce the risk of inflammation caused by long-term implantation and prevent the repetitive surgery for removal of existing stent. In this study, the effects of bicarbonate ion (HCO₃ - ) and mucin in Gamble's solution on the corrosion behavior of AZ31 magnesium alloy were investigated, using immersion and electrochemical tests to systematically identify the biodegradation kinetics of magnesium alloy under in vitro environment, mimicking the epithelial mucus surfaces in a trachea for development of biodegradable airway stents. Analysis of corrosion products after immersion test was performed using scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX) and X-ray diffraction (XRD). Electrochemical impedance spectroscopy (EIS) was used to identify the effects of bicarbonate ions and mucin on the corrosion behavior of AZ31 magnesium alloys with the temporal change of corrosion resistance. The results show that the increase of the bicarbonate ions in Gamble's solution accelerates the dissolution of AZ31 magnesium alloy, while the addition of mucin retards the corrosion. The experimental data in this work is intended to be used as foundational knowledge to predict the corrosion behavior of AZ31 magnesium alloy in the airway environment while providing degradation information for future in vivo studies.

Influence of Zeolite Coating on the Corrosion Resistance of AZ91D Magnesium Alloy

Directory of Open Access Journals (Sweden)

P. Chakraborty Banerjee

2014-08-01

Full Text Available The protective performance of zeolite coating on AZ91D magnesium alloy was evaluated using potentiodynamic polarisation and electrochemical impedance spectroscopy (EIS in 0.1 M sodium chloride solution (NaCl. Electrical equivalent circuit (EEC was developed based upon hypothetical corrosion mechanisms and simulated to correspond to the experimental data. The morphology and the chemical nature of the coating were characterized by scanning electron microscopy (SEM and X-ray diffraction (XRD analysis. Post corrosion morphologies of the zeolite coated and the uncoated AZ91D alloy were investigated using SEM. The corrosion resistance of the zeolite coated specimen was at least one order of magnitude higher than the uncoated specimen.

Cambio en azúcares fermentables en la remolacha azucarera almacenada en atmósferas aerobia y anaerobia para la producción de etanol

Directory of Open Access Journals (Sweden)

Juan Manuel Vargas Ramírez

2014-06-01

Full Text Available Los métodos de almacenamiento de largo plazo son necesarios para preservar los azúcares fermentables en la remolacha y permitir el funcionamiento exitoso a lo largo del año en las plantas procesadoras para la obtención de etanol. Se estudió el almacenamiento anaeróbico de la remolacha azucarera como una alternativa al almacenamiento convencional en pilas a la intemperie utilizado actualmente en fábricas de azúcar de remolacha. Los resultados experimentales indican una pérdida de <15% en el total de los azúcares fermentables en la remolacha azucarera almacenada anaeróbicamente durante 14 semanas a 4 °C. Después de 14 semanas de almacenamiento, 99 ± 4% de los azúcares fermentables iniciales fueron preservados en la remolacha almacenada en condiciones aeróbicas a 4 °C. El almacenamiento aeróbico y anaeróbico de remolacha azucarera a 25 ° C conserva 82 ± 9 y 48 ± 11% del contenido de azúcar fermentable, respectivamente. Los azúcares fermentables y etanol en exudados contribuyeron insignificantemente (<3% para el rendimiento del etanol global de remolacha azucarera después del almacenamiento.

A Study on Compressive Anisotropy and Nonassociated Flow Plasticity of the AZ31 Magnesium Alloy in Hot Rolling

Directory of Open Access Journals (Sweden)

Guoqiang Wang

2014-01-01

Full Text Available Effect of anisotropy in compression is studied on hot rolling of AZ31 magnesium alloy with a three-dimensional constitutive model based on the quadratic Hill48 yield criterion and nonassociated flow rule (non-AFR. The constitutive model is characterized by compressive tests of AZ31 billets since plastic deformations of materials are mostly caused by compression during rolling processes. The characterized plasticity model is implemented into ABAQUS/Explicit as a user-defined material subroutine (VUMAT based on semi-implicit backward Euler's method. The subroutine is employed to simulate square-bar rolling processes. The simulation results are compared with rolled specimens and those predicted by the von Mises and the Hill48 yield function under AFR. Moreover, strip rolling is also simulated for AZ31 with the Hill48 yield function under non-AFR. The strip rolling simulation demonstrates that the lateral spread generated by the non-AFR model is in good agreement with experimental data. These comparisons between simulation and experiments validate that the proposed Hill48 yield function under non-AFR provides satisfactory description of plastic deformation behavior in hot rolling for AZ31 alloys in case that the anisotropic parameters in the Hill48 yield function and the non-associated flow rule are calibrated by the compressive experimental results.

Precipitation behavior and effect of new precipitated β phase in AZ80 magnesium alloy

Institute of Scientific and Technical Information of China (English)

TANG Wei; HAN En-hou; XU Yong-bo; LIU Lu

2006-01-01

Granular precipitate that was a new kind of β-Mg17Al12 phase found in aged AZ80 wrought Mg alloy at all aging temperature was studied. The structure and precipitation behavior of this granular β-Mg17Al12 precipitate were studied by environmental scanning electron microscopy (ESEM) and transmission electron microscopy (TEM). The effect of the granular precipitate on mechanical properties of AZ80 alloy was also studied. The new precipitate that was granular and nucleated both on grain boundaries (GBs) and twin boundaries, has the same crystal structure and lattice parameter as those of the continuous or discontinuous precipitated β-Mg17Al12. And the nucleation and growth of the granular precipitate are faster than those of the other two precipitates at higher temperatures (above 583 K), but are suppressed at lower temperatures (below 423 K). At lower temperatures, the discontinuous β-Mg17Al12 precipitates firstly and the granular β-Mg17Al12 precipitates after aged more than 40 h. The crack is easily nucleated on the phase boundaries of granular phase and matrix because of the weak binding force. As a result, the strength and ductility of AZ80 Mg alloy are decreased by the granular β-Mg17Al12 precipitate.

Mixer pump test plan for double shell tank AZ-101

International Nuclear Information System (INIS)

STAEHR, T.W.

1999-01-01

Mixer pump systems have been chosen as the method for retrieval of tank wastes contained in double shell tanks at Hanford. This document describes the plan for testing and demonstrating the ability of two 300 hp mixer pumps to mobilize waste in tank AZ-101. The mixer pumps, equipment and instrumentation to monitor the test were installed by Project W-151

40 CFR 97.140 - State trading budgets.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 20 2010-07-01 2010-07-01 false State trading budgets. 97.140 Section...) FEDERAL NOX BUDGET TRADING PROGRAM AND CAIR NOX AND SO2 TRADING PROGRAMS CAIR NOX Allowance Allocations § 97.140 State trading budgets. The State trading budgets for annual allocations of CAIR NOX allowances...

21 CFR 163.140 - Skim milk chocolate.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 2 2010-04-01 2010-04-01 false Skim milk chocolate. 163.140 Section 163.140 Food... milk chocolate. (a) Description. Skim milk chocolate is the food that conforms to the standard of identity, and is subject to the requirements for label declaration of ingredients for milk chocolate in...

In vitro corrosion of pure magnesium and AZ91 alloy?the influence of thin electrolyte layer thickness

OpenAIRE

Zeng, Rong-Chang; Qi, Wei-Chen; Zhang, Fen; Li, Shuo-Qi

2016-01-01

In vivo degradation predication faces a huge challenge via in vitro corrosion test due to the difficulty for mimicking the complicated microenvironment with various influencing factors. A thin electrolyte layer (TEL) cell for in vitro corrosion of pure magnesium and AZ91 alloy was presented to stimulate the in vivo corrosion in the micro-environment built by the interface of the implant and its neighboring tissue. The results demonstrated that the in vivo corrosion of pure Mg and the AZ91 all...

Effect of interlayer configurations on joint formation in TLP bonding of Ti-6AI-4V to Mg-AZ31

International Nuclear Information System (INIS)

Atieh, A. M.; Khan, T. I.

2013-01-01

In this research work, the transient liquid phase (TLP) bonding process was utilized to fabricate joints using thin (20 micro m) nickel and copper foils placed between two bonding surfaces to help facilitate joint formation. Two joint configurations were investigated, first, Ti-6Al-4V/CuNi/Mg-AZ31 and second, Ti-6Al-4V/NiCu/Mg-AZ3L The effect of bonding time on microstructural developments across the joint and the changes in mechanical properties were studied as a function of bonding temperature and pressure. The bonded specimens were examined by metallographic analysis, scanning electron microscopy (SEM), and X-ray diffraction (XRD). In both cases, intermetallic phase of CuMg/sub 2/ and Mg/sub 3/AlNi/sub 2/ was observed inside the joint region. The results show that joint shear strengths for the Ti-6Al-4V/CuNi/Mg-AZ31 setup produce joints with shear strength of 57 MPa compared to 27MPa for joints made using the Ti-6Al-4V/NiCu/Mg-AZ31 layer arrangement. (author)

Effect of interlayer configurations on joint formation in TLP bonding of Ti-6Al-4V to Mg-AZ31

International Nuclear Information System (INIS)

Atieh, A M; Khan, T I

2014-01-01

In this research work, the transient liquid phase (TLP) bonding process was utilized to fabricate joints using thin (20μm) nickel and copper foils placed between two bonding surfaces to help facilitate joint formation. Two joint configurations were investigated, first, Ti-6Al-4V/CuNi/Mg-AZ31 and second, Ti-6Al-4V/NiCu/Mg-AZ3L The effect of bonding time on microstructural developments across the joint and the changes in mechanical properties were studied as a function of bonding temperature and pressure. The bonded specimens were examined by metallographic analysis, scanning electron microscopy (SEM), and X-ray diffraction (XRD). In both cases, intermetallic phase of CuMg 2 and Mg 3 AlNi 2 was observed inside the joint region. The results show that joint shear strengths for the Ti-6Al-4V/CuNi/Mg-AZ31 setup produce joints with shear strength of 57 MPa compared to 27MPa for joints made using the Ti-6Al-4V/NiCu/Mg-AZ31 layer arrangement

Evolution of twinning in extruded AZ31 alloy with bimodal grain structure

Energy Technology Data Exchange (ETDEWEB)

Garcés, G., E-mail: ggarces@cenim.csic.es [Department of Physical Metallurgy, National Centre for Metallurgical Research CENIM-CSIC, Av. De Gregorio del Amo 8, 28040 Madrid (Spain); Oñorbe, E. [CIEMAT, Division of Structural Materials, Avenida Complutense, 40, 28040 Madrid (Spain); Gan, W. [German Engineering Materials Science Centre at MLZ, Helmholtz-Zentrum Geesthacht, Lichtebergstr. 1, D-85747 Garching (Germany); Máthis, K. [Department of Physics of Materials, Faculty of Mathematics and Physics, Charles University, KeKarlovu 5, 121 16 Praha 2 (Czech Republic); Tolnai, D. [Institute of Materials Research, Helmholtz-Zentrum Geesthacht, Max-Planck-Str. 1, 21502 Geesthacht (Germany); Horváth, K. [Department of Physics of Materials, Faculty of Mathematics and Physics, Charles University, KeKarlovu 5, 121 16 Praha 2 (Czech Republic); Pérez, P.; Adeva, P. [Department of Physical Metallurgy, National Centre for Metallurgical Research CENIM-CSIC, Av. De Gregorio del Amo 8, 28040 Madrid (Spain)

2017-04-15

Twinning in extruded AZ31 alloy with a bimodal grain structure is studied under compression along the extrusion direction. This study has combined in-situ measurements during the compression tests by Synchrotron Radiation Diffraction and Acoustic Emission techniques and the evaluation of the microstructure and texture in post-mortem compression samples deformed at different strains. The microstructure of the alloy is characterized by the coexistence of large areas of fine dynamic recrystallized grains and coarse non-recrystallized grains elongated along extrusion direction. Twinning occurs initially in large elongated grains before the macroscopic yield stress which is controlled by the twinning in equiaxed dynamically recrystallized grains. - Highlights: • The AZ31 extruded at low temperature exhibits a bimodal grains structure. • Twinning takes place before macroscopic yielding in coarse non-DRXed grains. • DRXed grains controls the beginning of plasticity in magnesium alloys with bimodal grain structure.

Wire Arc Additive Manufacturing of AZ31 Magnesium Alloy: Grain Refinement by Adjusting Pulse Frequency

Directory of Open Access Journals (Sweden)

Jing Guo

2016-10-01

Full Text Available Wire arc additive manufacturing (WAAM offers a potential approach to fabricate large-scale magnesium alloy components with low cost and high efficiency, although this topic is yet to be reported in literature. In this study, WAAM is preliminarily applied to fabricate AZ31 magnesium. Fully dense AZ31 magnesium alloy components are successfully obtained. Meanwhile, to refine grains and obtain good mechanical properties, the effects of pulse frequency (1, 2, 5, 10, 100, and 500 Hz on the macrostructure, microstructure and tensile properties are investigated. The results indicate that pulse frequency can result in the change of weld pool oscillations and cooling rate. This further leads to the change of the grain size, grain shape, as well as the tensile properties. Meanwhile, due to the resonance of the weld pool at 5 Hz and 10 Hz, the samples have poor geometry accuracy but contain finer equiaxed grains (21 μm and exhibit higher ultimate tensile strength (260 MPa and yield strength (102 MPa, which are similar to those of the forged AZ31 alloy. Moreover, the elongation of all samples is above 23%.

In vitro corrosion of pure magnesium and AZ91 alloy—the influence of thin electrolyte layer thickness

Science.gov (United States)

Zeng, Rong-Chang; Qi, Wei-Chen; Zhang, Fen; Li, Shuo-Qi

2016-01-01

In vivo degradation predication faces a huge challenge via in vitro corrosion test due to the difficulty for mimicking the complicated microenvironment with various influencing factors. A thin electrolyte layer (TEL) cell for in vitro corrosion of pure magnesium and AZ91 alloy was presented to stimulate the in vivo corrosion in the micro-environment built by the interface of the implant and its neighboring tissue. The results demonstrated that the in vivo corrosion of pure Mg and the AZ91 alloy was suppressed under TEL condition. The AZ91 alloy was more sensitive than pure Mg to the inhibition of corrosion under a TEL thickness of less than 200 µm. The TEL thickness limited the distribution of current, and thus localized corrosion was more preferred to occur under TEL condition than in bulk solution. The TEL cell might be an appropriate approach to simulating the in vivo degradation of magnesium and its alloys. PMID:26816655

14 CFR 1264.140 - Stay pending appeal.

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 5 2010-01-01 2010-01-01 false Stay pending appeal. 1264.140 Section 1264... FRAUD CIVIL PENALTIES ACT OF 1986 § 1264.140 Stay pending appeal. (a) An initial decision is stayed automatically pending disposition of a motion for reconsideration or of an appeal to the authority head. (b) No...

Strongly coupled band in {sup 140}Gd

Energy Technology Data Exchange (ETDEWEB)

Falla-Sotelo, F.; Oliveira, J.R.B.; Rao, M.N. [Instituto de Fisica, Universidade de Sao Paulo, Sao Paulo (Brazil)] (and others)

2005-07-01

Several high-K states are known to exist in the mass 130-140 region. For the N=74 even-even isotopes, K{pi} = 8{sup -} isomers, with lifetimes ranging from ns to ms, are known in {sup 128}Xe, {sup 130}Ba, {sup 132}Ce, {sup 134}Nd, {sup 136}Sm, and {sup 138}Gd[. In {sup 140}Gd, we have observed for the first time a band also based on an I{pi} = 8{sup -} state. This could be the first case of a K{pi} = 8{sup -} state observed in an N=76 even-even isotope. The systematics of the K{pi} = 8{sup -} isomeric states in N=74 isotopes has been studied by A.M. Bruce et al. These states decay towards the K = 0 ground state band, and the transitions are K-forbidden. The {sup 140}Gd case presents strong similarities but also some significant differences with relation to the N=74 isotopes. We propose the same configuration but with larger deformation in {sup 140}Gd.

Corrosion of AZ91D magnesium alloy with a chemical conversion coating and electroless nickel layer

International Nuclear Information System (INIS)

Huo Hongwei; Li Ying; Wang Fuhui

2004-01-01

A chemical conversion treatment and an electroless nickel plating were applied to AZ91D alloy to improve its corrosion resistance. By conversion treatment in alkaline stannate solution, the corrosion resistance of the alloy was improved to some extent as verified by immersion test and potentiodynamic polarization test in 3.5 wt.% NaCl solution at pH 7.0. X-ray diffraction patterns of the stannate treated AZ91D alloy showed the presence of MgSnO 3 · H 2 O, and SEM images indicated a porous structure, which provided advantage for the adsorption during sensitisation treatment prior to electroless nickel plating. A nickel coating with high phosphorus content was successfully deposited on the chemical conversion coating pre-applied to AZ91D alloy. The presence of the conversion coating between the nickel coating and the substrate reduced the potential difference between them and enhanced the corrosion resistance of the alloy. An obvious passivation occurred for the nickel coating during anodic polarization in 3.5 wt.% NaCl solution

Qualitative Research of AZ31 Magnesium Alloy Aircraft Brackets Produced by a New Forging Method

Directory of Open Access Journals (Sweden)

Dziubińska A.

2016-06-01

Full Text Available The paper reports a selection of numerical and experimental results of a new closed-die forging method for producing AZ31 magnesium alloy aircraft brackets with one rib. The numerical modelling of the new forming process was performed by the finite element method.The distributions of stresses, strains, temperature and forces were examined. The numerical results confirmed that the forgings produced by the new forming method are correct. For this reason, the new forming process was verified experimentally. The experimental results showed good agreement with the numerical results. The produced forgings of AZ31 magnesium alloy aircraft brackets with one rib were then subjected to qualitative tests.

Cytotoxicity studies of AZ31D alloy and the effects of carbon dioxide on its biodegradation behavior in vitro

Energy Technology Data Exchange (ETDEWEB)

Wang, Jiali, E-mail: wangjialicsu@yahoo.cn [Center for Translational Medicine Research and Development, Institute of Biomedical and Health Engineering, Chinese Academy of Sciences, Shenzhen 518055 (China); Musculoskeletal Research Laboratory, Department of Orthopaedics and Traumatology, The Chinese University of Hong Kong, Hong Kong SAR (China); Qin, Ling [Center for Translational Medicine Research and Development, Institute of Biomedical and Health Engineering, Chinese Academy of Sciences, Shenzhen 518055 (China); Musculoskeletal Research Laboratory, Department of Orthopaedics and Traumatology, The Chinese University of Hong Kong, Hong Kong SAR (China); Wang, Kai [School of Humanities and Social Sciences, Hunan University of Chinese Medicine, Changsha 410208 (China); Wang, Jue; Yue, Ye [Center for Translational Medicine Research and Development, Institute of Biomedical and Health Engineering, Chinese Academy of Sciences, Shenzhen 518055 (China); Li, Yangde [Guangdong Innovation Team for Biodegradable Magnesium and Medical Implants, E-ande, Dongguan 523660 (China); Tang, Jian [Center for Translational Medicine Research and Development, Institute of Biomedical and Health Engineering, Chinese Academy of Sciences, Shenzhen 518055 (China); Li, Weirong [Guangdong Innovation Team for Biodegradable Magnesium and Medical Implants, E-ande, Dongguan 523660 (China)

2013-10-01

Magnesium alloys have been advocated as potential artificial bone materials due to their biocompatibility and biodegradability. The understanding of their corrosive mechanism in physiological environments is therefore essential for making application-orientated designs. Thus, this in vitro study was designed to assess the effects of CO{sub 2} on corrosive behavior of AZ31D to mimic in vivo special ingredient. Electrochemical technologies accompanied with Scanning electron microscope, Fourier transform infrared, X-ray diffraction, Energy dispersive spectroscopy and hydrogen evolution measurement were employed to analyze corrosive rates and mechanisms of AZ31D. Moreover, the biocompatibility of AZ31D was assessed with a direct cell attachment assay and an indirect cytotoxicity test in different diluted extracts. The ion concentrations in extracts were measured using inductively coupled plasma mass spectrometry to offer explanations on the differences of cell viability in the indirect test. The results of the direct cytotoxicity assay showed that the corrosive rate of AZ31D was too rapid to allow for cell adhesion. Extracts diluted less than 20 times would cause adverse effects on cell proliferation, likely due to excessive ions and gas release. Moreover, the presence of CO{sub 2} did not cause significant differences on corrosive behavior of AZ31D according to the results of electrochemical testing and hydrogen evolution measurement. This might be caused by the simultaneous process of precipitation and dissolution of MgCO{sub 3} due to the penetration role of CO{sub 2}. This analysis of corrosive atmospheres on the degradation behavior of magnesium alloys would contribute to the design of more scientific in vitro testing systems in the future. - Highlights: • We evaluate the effects of CO{sub 2} on corrosion behavior of magnesium alloys. • We assess the feasibility of commercial AZ31D alloy as potential implants. • CO{sub 2} is not the key factor to minimize

27 CFR 1.40 - Change of name.

Science.gov (United States)

2010-04-01

... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Change of name. 1.40... Amendment and Duration of Basic Permits § 1.40 Change of name. In the event of any change in the name (trade or corporate name) of a permittee, or, in the event a permittee desires to engage in operations under...

Fatigue characteristics of sand-cast AZ91D magnesium alloy

Directory of Open Access Journals (Sweden)

Zhenming Li

2017-03-01

Full Text Available The fatigue characteristics of the AZ91D-T6 alloy samples taken from engine blocks have been investigated at 20 °C and elevated temperature (150 °C. The fatigue strength and cyclic stress amplitude of the alloy significantly decrease with the increase of the test temperature, although cyclic hardening occurs continuously until failure for both temperatures. With the increase of the temperature, the decreased fatigue life of the alloy tested at the same stress amplitude is mainly attributed to the decreased matrix strength and the increased hysteresis energies. Fatigue failure of the engine blocks made of AZ91D-T6 alloy is mainly controlled by casting defects. For the defect-free specimens, the crack initiation behavior is determined by the single-slip (20 °C and by environment-assisted cyclic slip (150 °C during fatigue, respectively. The low-cycle fatigue lives of the alloy can be predicted using the Coffin-Manson relation and Basquin laws, the three-parameter equation and the energy-based concepts, while the high-cycle fatigue lives of the alloy fitted well with the developed long crack life model and MSF life models.

Pengaruh waktu kontak terhadap kualitas sambungan hasil las gesek (Friction Welding Magnesium AZ-31

Directory of Open Access Journals (Sweden)

Solihin Solihin

2018-01-01

Full Text Available Abstrak: Pengelasan merupakan salah suatu proses penyambungan dua atau lebih bahan teknik, dengan atau tanpa peroses pencairan logam dasarnya. Teknologi Las Gesek (Friction Welding, FW merupakan salah satu teknik pengelasan padat atau pengelasan tanpa proses pencairan (solid-state welding. Pembangkitan panas dalam proses FW dihasilkan dengan cara menggesekkan permukaan material las (base metal hingga mencapai temperatur penyambungannya (semi-solid temperature atau sekitar 80% dari temperature cair bahan, dan dalam hal Magnesium AZ31 adalah sekitar temperatur 5500C. Setelah bahan mencapai temperatur semi-solid tersebut, kemudian diberi tekanan agar terjadi proses penyambungan. Penelitian ini bertujuan untuk mengetahui pengaruh variasi proses terhadap kualitas hasil pengelasan gesek, yang meliputi: kekuatan tarik, struktur makro, dan nilai kekerasan bahan hasil las. Parameter pengujiannya adalah variasi waktu kontak las, yaitu selama 3, 5, dan 10 menit. Kecepatan putar spindle selama proses pengelasan ditetapkan 1400 rpm. Hasil pengelasan menunjukkan bahwa waktu kontak gesek 3 menit menghasilkan kekuatan tarik tertinggi (16,78 MPa, bila dibandingkan dengan dua parameter lain. Hasil uji keras pada daerah las (stir zone menunjukkan angka kekerasan rata-rata yang relative konsisten, atau sebesar 60 HRE untuk semua parameter, sedangkan angka kekerasan rata-rata di daerah terpengaruh panas (heat affected zone, HAZ untuk waktu kontak gesek 3, 5 dan 10 menit secara berturut-turut adalah sebesar 69,6; 64,6; dan 60,6 HRE. Hasil penelitian awal ini memberikan potensi studi lanjutan pada berbagai parameter pengelasan lain agar didapatkan kualitas sambungan las gesek yang optimum untuk proses pengelasan gesek Magnesium AZ-31. Kata Kunci: Las gesek, Magnesium AZ-31, struktur makro, cacat void. Abstract: Welding is a process technology aiming to join two or more materials. Friction Welding (FW is including in a solid-state technology cluster, where the heat is

Lysobacter capsici AZ78 produces cyclo(L-Pro-L-Tyr), a 2,5-diketopiperazine with toxic activity against sporangia of Phytophthora infestans and Plasmopara viticola.

Science.gov (United States)

Puopolo, G; Cimmino, A; Palmieri, M C; Giovannini, O; Evidente, A; Pertot, I

2014-10-01

To investigate low molecular weight compounds produced in vitro by Lysobacter capsici AZ78 and their toxic activity against sporangia of plant pathogenic oomycetes. Assays carried out in vitro showed that L. capsici AZ78 drastically inhibits the growth of plant pathogenic oomycetes. Accordingly, the preventive application of culture filtrates of L. capsici AZ78 on grapevine and tomato plants reduced the infections, respectively, caused by Plasmopara (Pl.) viticola and Phytophthora infestans. The subsequent chemical analysis of the culture filtrates of L. capsici AZ78 by spectroscopic (essentially 1D and 2D (1)H NMR and (13)C NMR and ESI MS spectra) and optical methods led to the identification of the 2,5-diketopiperazine cyclo(L-Pro-L-Tyr) that inhibited the development of P. infestans sporangia in vitro and on tomato leaves. Furthermore, a genomic region with high sequence identity with genes coding for a hybrid polyketide synthase and nonribosomal peptide synthetase was detected in L. capsici AZ78. Lysobacter capsici AZ78 produces cyclo(L-Pro-L-Tyr) in vitro that was effective in killing the sporangia of P. infestans and Pl. viticola in vitro. Moreover, this low molecular weight compound prevents the occurrence of late blight lesions when applied on tomato leaves. The application of L. capsici AZ78 cells or its own culture filtrates effectively controls both P. infestans and Pl. viticola. Cyclo(L-Pro-L-Tyr) produced by L. capsici AZ78 is toxic against sporangia of both these oomycetes. These data enforce the potential in the use of Lysobacter members for the control of plant pathogenic oomycetes and provide the basis for the development of new low-impact fungicides based on cyclo(L-Pro-L-Tyr). © 2014 The Society for Applied Microbiology.

Azúcar agridulce: trabajo y sindicatos en la agroindustria azucarera colombiana, 1960-1980

Directory of Open Access Journals (Sweden)

Juan Sebastián Marulanda Restrepo

2012-07-01

Full Text Available

Resumen

Esta investigación reconstruye el contexto laboral de los obreros en la agroindustria azucarera en Colombia entre los años de 1960 y 1980, un periodo de cambios profundos en las condiciones del trabajo de los trabajadores azucareros por cuenta de las transformaciones en este particular tipo de industria. Entre estas deben citarse hechos como la introducción de nuevas tecnologías en el cultivo de la caña y el incremento de la necesidad de mano de obra, producto de la expansión de las zonas cultivadas y al aumento de la producción, debidas a la apertura de mercados como Estados Unidos, cerrados al azúcar cubano a causa de la Revolución. Por otro lado, el sindicalismo azucarero estuvo inmerso en contradicciones que hicieron problemática la cohesión entre las diferentes organizaciones. En síntesis, las circunstancias mencionadas modificaron sustancialmente el panorama laboral de los obreros azucareros.

Palabras claves: obreros azucareros, industria azucarera, ingenios, salarios, sindicatos.

Abstract

This investigation reconstruct the employment context of the workers in the sugar industry in Colombia between 1960 and 1980, a period of profound changes in conditions of sugar workers on account of the transformations in this particular kind of industry. Between these transformations must be mentioned facts as the introduction of new technologies in the cane farming and the increase of need of farm workers, due to the expansion of cane farms and the rise of sugar production, because of the openness of markets such as United States, closed to cuban sugar because of the Revolution. On the other hand, the sugar labor union movement was immersed in contradictions that were problematic the unity between different organizations. In short, the mentioned circumstances substantially

Evaluación de la mezcla de ametrina + clomazone en caña de azúcar

Directory of Open Access Journals (Sweden)

Valent\\u00EDn A. Esqueda

2001-01-01

Full Text Available caña de azúcar. Se estableció un experimento en el Rancho Casablanca, Municipio de Puente Nacional, en el estado de Veracruz, México, para evaluar la toxicidad ocasionada por la mezcla de los herbicidas ametrina + clomazone a las variedades de caña de azúcar MEX-79-431, MEX-69-290, MEX-68- P23 y CP-72-2086. Se evaluaron cuatro tratamientos de control de malezas: 1. Ametrina + clomazone (1200 + 800 g/ha, 2. Ametrina + clomazone (1800 + 1200 g/ha, 3. Ametrina + 2,4-D (1225 + 650 g/ha y 4. Testigo limpio. Los herbicidas se aplicaron cuando la caña de azúcar tenía entre dos y cuatro hojas. La mezcla de ametrina + clomazone ocasionó blanqueamiento del follaje en todas las variedades de caña de azú- car. El área con blanqueamiento, varió entre el 36,3 y 47,5% con la dosis mas alta de esta mezcla; entre el 25 y 39,4%, con la dosis menor y prácticamente desapareció a los 45 días despu és de la aplicación. A su vez, la mezcla de ametrina + 2,4- D no ocasionó blanqueamiento. La toxicidad ocasionada por la mezcla de ametrina + clomazone no afectó el número de hojas por planta, el número de tallos en 2 m lineales y la altura de las plantas. Tampoco fueron afectados el rendimiento de tallos y el contenido de sacarosa

N terminus of Swr1 binds to histone H2AZ and provides a platform for subunit assembly in the chromatin remodeling complex.

Science.gov (United States)

Wu, Wei-Hua; Wu, Chwen-Huey; Ladurner, Andreas; Mizuguchi, Gaku; Wei, Debbie; Xiao, Hua; Luk, Ed; Ranjan, Anand; Wu, Carl

2009-03-06

Variant histone H2AZ-containing nucleosomes are involved in the regulation of gene expression. In Saccharomyces cerevisiae, chromatin deposition of histone H2AZ is mediated by the fourteen-subunit SWR1 complex, which catalyzes ATP-dependent exchange of nucleosomal histone H2A for H2AZ. Previous work defined the role of seven SWR1 subunits (Swr1 ATPase, Swc2, Swc3, Arp6, Swc5, Yaf9, and Swc6) in maintaining complex integrity and H2AZ histone replacement activity. Here we examined the function of three additional SWR1 subunits, bromodomain containing Bdf1, actin-related protein Arp4 and Swc7, by analyzing affinity-purified mutant SWR1 complexes. We observed that depletion of Arp4 (arp4-td) substantially impaired the association of Bdf1, Yaf9, and Swc4. In contrast, loss of either Bdf1 or Swc7 had minimal effects on overall complex integrity. Furthermore, the basic H2AZ histone replacement activity of SWR1 in vitro required Arp4, but not Bdf1 or Swc7. Thus, three out of fourteen SWR1 subunits, Bdf1, Swc7, and previously noted Swc3, appear to have roles auxiliary to the basic histone replacement activity. The N-terminal region of the Swr1 ATPase subunit is necessary and sufficient to direct association of Bdf1 and Swc7, as well as Arp4, Act1, Yaf9 and Swc4. This same region contains an additional H2AZ-H2B specific binding site, distinct from the previously identified Swc2 subunit. These findings suggest that one SWR1 enzyme might be capable of binding two H2AZ-H2B dimers, and provide further insight on the hierarchy and interdependency of molecular interactions within the SWR1 complex.

Microstructural evolution and tensile mechanical properties of thixoformed AZ91D magnesium alloy with the addition of yttrium

International Nuclear Information System (INIS)

Zhao Zude; Chen Qiang; Kang Feng; Shu Dayu

2009-01-01

The microstructure evolution of AZ91D magnesium alloy in the semi-solid state has been proposed or reported in previous literature. However, no detailed investigation has been conducted regarding the relationship between the microstructure and tensile mechanical properties of the thixoformed AZ91D magnesium alloy. In this paper, the microstructure of AZ91D alloy with the addition of yttrium was produced by the semi-solid thermal transformation (SSTT) route and the strain-induced melt activation (SIMA) route, respectively. Isothermal holding experiments investigated grain coarsening and the degree of spheroidization as a function of holding time in the semi-solid state. The SSTT route and the SIMA route were used to obtain the semi-solid feedstock for thixoforming. The results show that solid particles of the SSTT alloy are spheroidized to some extent but the previous irregular shape is still obvious in some of them. While the SIMA alloy exhibits ideal, fine microstructure, in which completely spheroidized solid particles contain little entrapped liquid. The microstructure of the SSTT alloy is less spheroidized compared with the SIMA alloy under the similar isothermal holding condition. As the holding time increases, the mean solid particle size of the SSTT alloy decreases initially, then increases, while the mean solid particle size of the SIMA alloy increases monotonously at 560 deg. C. Compared with the SSTT alloy, the SIMA alloy obtains finer grains under the similar isothermal holding condition. The mechanical properties of the thixoformed AZ91D alloy with the addition of yttrium produced by the SIMA route are better than those of the thixoformed alloy produced by the SSTT route. The ultimate tensile strength, yield strength and elongation for the thixoformed alloy produced by the SIMA route are 303.1 MPa, 147.6 MPa and 13.27%, respectively. The tensile properties for the AZ91D alloy with the addition of yttrium thixoformed from starting material produced by

Comparison of simulants to actual neutralized current acid waste: process and product testing of three NCAW core samples from Tanks 101-AZ and 102-AZ

Energy Technology Data Exchange (ETDEWEB)

Morrey, E.V.; Tingey, J.M.; Elliott, M.L.

1996-10-01

A vitrification plant is planned to process the high-level waste (HLW) solids from Hanford Site tanks into canistered glass logs for disposal in a national repository. Programs were established within the Pacific Northwest Laboratory Vitrification Technology Development (PVTD) Project to test and model simulated waste to support design, feed processability, operations, permitting, safety, and waste-form qualification. Parallel testing with actual radioactive waste was performed on a laboratory-scale to confirm the validity of using simulants and glass property models developed from simulants. Laboratory-scale testing has been completed on three radioactive core samples from tanks 101-AZ and 102-AZ containing neutralized current acid waste (NCAW), which is one of the first waste types to be processed in the high-level waste vitrification plant under a privatization scenario. Properties of the radioactive waste measured during process and product testing were compared to simulant properties and model predictions to confirm the validity of simulant and glass property ,models work. This report includes results from the three NCAW core samples, comparable results from slurry and glass simulants, and comparisons to glass property model predictions.

Comparison of simulants to actual neutralized current acid waste: Process and product testing of three NCAW core samples from Tanks 101-AZ and 102-AZ

Energy Technology Data Exchange (ETDEWEB)

Morrey, E.V.; Tingey, J.M.

1996-04-01

A vitrification plant is planned to process the high-level waste (HLW) solids from Hanford Site tanks into canistered glass logs for disposal in a national repository. Programs have been established within the Pacific Northwest Laboratory Vitrification Technology Development (PVTD) Project to test and model simulated waste to support design, feed processability, operations, permitting, safety, and waste-form qualification. Parallel testing with actual radioactive waste is being performed on a laboratory-scale to confirm the validity of using simulants and glass property models developed from simulants. Laboratory-scale testing has been completed on three radioactive core samples from tanks 101-AZ and 102-AZ containing neutralized current acid waste (NCAW), which is one of the first waste types to be processed in the high-level waste vitrification plant under a privatization scenario. Properties of the radioactive waste measured during process and product testing were compared to simulant properties and model predictions to confirm the validity of simulant and glass property models work. This report includes results from the three NCAW core samples, comparable results from slurry and glass simulants, and comparisons to glass property model predictions.

Mechanical properties of AZ31 alloy processed by a green metallurgy route; Propiedades mecanicas de la aleacion AZ31 procesada por una ruta eco-sostenible

Energy Technology Data Exchange (ETDEWEB)

D' Enrico, F.; Garces, G.; Hofer, M.; Kim, S. K.; Perez, P.; Cabeza, S.; Adeva, P.

2013-07-01

Recently it has been proved that molding of defect-free components of various commercial alloys of magnesium can be carried out successfully when small amounts of CaO are added to the melt, making unnecessary the use of SF{sub 6} coverage. In the case of AZ alloys, this process also remarkably improves their mechanical properties not only by the greater cleaning of alloys but also by the formation of CaAl{sub 2} phase. This work, part of the Green project Metallurgy (http://www.green-metallurgy.eu) funded by the European Union (LIFE+2009), studies the influence of different CaO additions on the microstructure and mechanical properties of AZ31 Eco-Mg alloy. The alloy was processed by a conventional route involving extrusion of as-cast rods as well as by a powder metallurgy route (PM) using chips as starting material. The objective was to analyze the viability of recycling machining chips to manufacture components for the automobile industry and transportation in general, because of its low cost and environmental impact. It has been demonstrated that alloys processed from chips exhibit the highest tensile stress values, close to 320 MPa. (Author)

Comparison of simulants to actual neutralized current acid waste: process and product testing of three NCAW core samples from Tanks 101-AZ and 102-AZ

International Nuclear Information System (INIS)

Morrey, E.V.; Tingey, J.M.; Elliott, M.L.

1996-10-01

A vitrification plant is planned to process the high-level waste (HLW) solids from Hanford Site tanks into canistered glass logs for disposal in a national repository. Programs were established within the Pacific Northwest Laboratory Vitrification Technology Development (PVTD) Project to test and model simulated waste to support design, feed processability, operations, permitting, safety, and waste-form qualification. Parallel testing with actual radioactive waste was performed on a laboratory-scale to confirm the validity of using simulants and glass property models developed from simulants. Laboratory-scale testing has been completed on three radioactive core samples from tanks 101-AZ and 102-AZ containing neutralized current acid waste (NCAW), which is one of the first waste types to be processed in the high-level waste vitrification plant under a privatization scenario. Properties of the radioactive waste measured during process and product testing were compared to simulant properties and model predictions to confirm the validity of simulant and glass property ,models work. This report includes results from the three NCAW core samples, comparable results from slurry and glass simulants, and comparisons to glass property model predictions

Comparison of simulants to actual neutralized current acid waste: Process and product testing of three NCAW core samples from Tanks 101-AZ and 102-AZ

International Nuclear Information System (INIS)

Morrey, E.V.; Tingey, J.M.

1996-04-01

A vitrification plant is planned to process the high-level waste (HLW) solids from Hanford Site tanks into canistered glass logs for disposal in a national repository. Programs have been established within the Pacific Northwest Laboratory Vitrification Technology Development (PVTD) Project to test and model simulated waste to support design, feed processability, operations, permitting, safety, and waste-form qualification. Parallel testing with actual radioactive waste is being performed on a laboratory-scale to confirm the validity of using simulants and glass property models developed from simulants. Laboratory-scale testing has been completed on three radioactive core samples from tanks 101-AZ and 102-AZ containing neutralized current acid waste (NCAW), which is one of the first waste types to be processed in the high-level waste vitrification plant under a privatization scenario. Properties of the radioactive waste measured during process and product testing were compared to simulant properties and model predictions to confirm the validity of simulant and glass property models work. This report includes results from the three NCAW core samples, comparable results from slurry and glass simulants, and comparisons to glass property model predictions

CSER 96-014: criticality safety of project W-151, 241-AZ-101 retrieval system process test

Energy Technology Data Exchange (ETDEWEB)

Vail, T.S., Fluor Daniel Hanford

1997-02-06

This Criticality Safety Evaluation Report (CSER) documents a review of the criticality safety implications of a process test to be performed in tank 241-AZ-101 (101-AZ). The process test will determine the effectiveness of the retrieval system for mobilization of solids and the practicality of the system for future use in the underground storage tanks at Hanford. The scope of the CSER extends only to the testing and operation of the mixer pumps and does not include the transfer of waste from the tank. Justification is provided that a nuclear criticality is extremely unlikely, if not impossible, in this tank.

Estereotipos sobre el envejecimiento seg?n el periodo del desarrollo y el g?nero

OpenAIRE

Sandino Forero, Juliana

2016-01-01

Teniendo en cuenta el dr?stico aumento en Colombia y el mundo de la poblaci?n adulta mayor la pir?mide poblacional se ha invertido. Lo que ha generado que cada vez haya m?s adultos mayores y la esperanza de vida sea mayor. Motivo por el cual surge la importancia de conocer diversos aspectos del envejecimiento, entre ellos los estereotipos. Adicionalmente hay muy poca investigaci?n relacionada con los estereotipos sobre el envejecimiento seg?n el g?nero y el periodo de desarrollo. Levy (2009)...

Geologie study off gravels of the Agua Fria River, Phoenix, AZ

Science.gov (United States)

Langer, W.H.; Dewitt, E.; Adams, D.T.; O'Briens, T.

2010-01-01

The annual consumption of sand and gravel aggregate in 2006 in the Phoenix, AZ metropolitan area was about 76 Mt (84 million st) (USGS, 2009), or about 18 t (20 st) per capita. Quaternary alluvial deposits in the modern stream channel of the Agua Fria River west of Phoenix are mined and processed to provide some of this aggregate to the greater Phoenix area. The Agua Fria drainage basin (Fig. 1) is characterized by rugged mountains with high elevations and steep stream gradients in the north, and by broad alluvial filled basins separated by elongated faultblock mountain ranges in the south. The Agua Fria River, the basin’s main drainage, flows south from Prescott, AZ and west of Phoenix to the Gila River. The Waddel Dam impounds Lake Pleasant and greatly limits the flow of the Agua Fria River south of the lake. The southern portion of the watershed, south of Lake Pleasant, opens out into a broad valley where the river flows through urban and agricultural lands to its confluence with the Gila River, a tributary of the Colorado River.

Effect of Mucin and Bicarbonate Ion on Corrosion Behavior of AZ31 Magnesium Alloy for Airway Stents

Directory of Open Access Journals (Sweden)

Yongseok Jang

2014-08-01

Full Text Available The biodegradable ability of magnesium alloys is an attractive feature for tracheal stents since they can be absorbed by the body through gradual degradation after healing of the airway structure, which can reduce the risk of inflammation caused by long-term implantation and prevent the repetitive surgery for removal of existing stent. In this study, the effects of bicarbonate ion (HCO3− and mucin in Gamble’s solution on the corrosion behavior of AZ31 magnesium alloy were investigated, using immersion and electrochemical tests to systematically identify the biodegradation kinetics of magnesium alloy under in vitro environment, mimicking the epithelial mucus surfaces in a trachea for development of biodegradable airway stents. Analysis of corrosion products after immersion test was performed using scanning electron microscopy (SEM, energy dispersive X-ray spectroscopy (EDX and X-ray diffraction (XRD. Electrochemical impedance spectroscopy (EIS was used to identify the effects of bicarbonate ions and mucin on the corrosion behavior of AZ31 magnesium alloys with the temporal change of corrosion resistance. The results show that the increase of the bicarbonate ions in Gamble’s solution accelerates the dissolution of AZ31 magnesium alloy, while the addition of mucin retards the corrosion. The experimental data in this work is intended to be used as foundational knowledge to predict the corrosion behavior of AZ31 magnesium alloy in the airway environment while providing degradation information for future in vivo studies.

Microstructure characteristics and effect of aging process on the mechanical properties of squeeze-cast AZ91 alloy

International Nuclear Information System (INIS)

Han, G.M.; Han, Z.Q.; Luo, A.A.; Liu, B.C.

2015-01-01

Highlights: • Characterization of three-dimensional morphologies of precipitates using AFM. • Quantitative microstructure of aged squeeze-cast AZ91 alloy. • The non-uniform continuous precipitation during aging of squeeze-cast AZ91 alloy. • The relationship between microstructure and property of aged squeeze-cast AZ91 alloy. - Abstract: Quantitative microstructure information is critical to modeling and prediction of mechanical properties of structural components. In this study, the microstructure characteristics of aged squeeze-cast AZ91 alloy were investigated using scanning electron microscopy (SEM), transmission electron microscopy (TEM), and atomic force microscopy (AFM) analyses. Particularly, a study of the three-dimensional morphology of continuous precipitation during heat treatment was carried out using a combination of TEM and AFM. The results showed that a typical precipitate consisted of three kinds of faces, namely, broad, side, and end faces. The precipitate also presented a lath-shaped morphology with lozenge ends. Combined SEM and TEM analyses revealed quantitative information on the sizes and area number densities of precipitates after aging at different temperatures with different times. In general, the length and width of precipitates increased more rapidly than thickness during aging. The area number density initially increased and then slowly decreased because of coarsening. Furthermore, a special microstructure characteristic of the non-uniform continuous precipitation during aging was investigated using electron probe microanalysis (EPMA). The relationship between hardness response and yield strength was established

75 FR 11939 - DNS Electronics, Chandler, AZ; Notice of Termination of Investigation

Science.gov (United States)

2010-03-12

... DEPARTMENT OF LABOR Employment and Training Administration [TA-W-70,654] DNS Electronics, Chandler, AZ; Notice of Termination of Investigation Pursuant to Section 223 of the Trade Act of 1974, as... on behalf of workers of DNS Electronics, Chandler, Arizona. The petitioning group of workers is...

Comportamiento frente a la corrosión y biocompatibilidad in vitro/in vivo de la aleación AZ31 modificada superficialmente

Directory of Open Access Journals (Sweden)

Escudero, M. L.

2011-06-01

Full Text Available The present work evaluates the corrosion behaviour and the in vitro/in vivo biocompatibility of the AZ31 magnesium alloy, which fulfills the mechanical requirements of bone. The corrosion kinetic of as-received AZ31 alloy was not compatible with the cell growth. To improve its performance, the AZ31 alloy was surface modified by a chemical conversion treatment in hydrofluoric acid. The magnesium fluoride layer generated by the surface treatment of AZ31 alloy enhances its corrosion behaviour, allowing the in vitro growth of osteoblastic cells over the surface and the in vivo formation of a highly compact layer of new bone tissue. These results lead to consider the magnesium fluoride coating as necessary for potential use of the AZ31 alloy as biodegradable and absorbable implant for bone repair.En el presente trabajo se ha estudiado el comportamiento frente a la corrosión y la biocompatibilidad in vitro/in vivo de la aleación de magnesio AZ31, cuyas propiedades mecánicas son superiores a los requisitos mecánicos del hueso. La aleación en estado de recepción ha mostrado una cinética de corrosión no compatible con el crecimiento celular. Para mejorar su comportamiento, el material ha sido modificado superficialmente mediante tratamiento de conversión química en ácido fluorhídrico. La capa de fluoruro de magnesio generada tras este tratamiento mejora el comportamiento del material frente a la corrosión, permitiendo el crecimiento in vitro de células osteoblásticas sobre su superficie y la formación in vivo de una capa de nuevo tejido óseo muy compacta. Estos resultados permiten concluir que el recubrimiento de fluoruro de magnesio es necesario para que el material AZ31 pueda ser potencialmente aplicado como implante biodegradable y reabsorbible en reparaciones óseas.

Preparation and characterization of inorganic and organic coatings on AZ91D magnesium alloy with electroless plating pretreatment

Energy Technology Data Exchange (ETDEWEB)

Zhang, S.Y.; Li, Q.; Zhang, H.X.; Wang, S.Y.; Liu, F. [School of Chemistry and Chemical Engineering, Southwest University Chongqing, 400715 (China); Yang, X.K. [School of Materials Science and Engineering, Southwest University Chongqing, 400715 (China)

2011-09-15

In this paper, a protective coating scheme was applied for the corrosion protection of AZ91D magnesium alloy. Electroless Ni coating (EN coating) as bottom layer, electrodeposited Ni coating (ENN coating), and silane-based coating (ENS coating) as top layer, respectively, were successfully prepared on AZ91D magnesium alloy by combination techniques. Scanning electron microscopy and X-ray diffraction were employed to investigate the surface and phase structure of coatings, respectively. The electrochemical corrosion behaviors of coatings in neutral 3.5 wt% NaCl solution were evaluated by electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization techniques. The corrosion testing showed that the three kinds of coatings all could provide corrosion protection for AZ91D magnesium alloy to a certain extent, and the corrosion resistance of ENN and ENS was superior to EN. In order to further study the corrosion protection properties of ENN and ENS, a comparative investigation on the evolution of EIS of ENN and ENS was carried out by dint of immersion test in neutral 3.5 wt% NaCl solution. The results indicated that, compared with ENN, the ENS could provide longer corrosion protection for AZ91D magnesium alloy. It is significant to determine the barrier effect of each coating, which could provide reference for industry applications. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Pump Jet Mixing and Pipeline Transfer Assessment for High-Activity Radioactive Wastes in Hanford Tank 241-AZ-102

Energy Technology Data Exchange (ETDEWEB)

Y Onishi; KP Recknagle; BE Wells

2000-08-09

The authors evaluated how well two 300-hp mixer pumps would mix solid and liquid radioactive wastes stored in Hanford double-shell Tank 241-AZ-102 (AZ-102) and confirmed the adequacy of a three-inch (7.6-cm) pipeline system to transfer the resulting mixed waste slurry to the AP Tank Farm and a planned waste treatment (vitrification) plant on the Hanford Site. Tank AZ-102 contains 854,000 gallons (3,230 m{sup 3}) of supernatant liquid and 95,000 gallons (360 m{sup 3}) of sludge made up of aging waste (or neutralized current acid waste). The study comprises three assessments: waste chemistry, pump jet mixing, and pipeline transfer. The waste chemical modeling assessment indicates that the sludge, consisting of the solids and interstitial solution, and the supernatant liquid are basically in an equilibrium condition. Thus, pump jet mixing would not cause much solids precipitation and dissolution, only 1.5% or less of the total AZ-102 sludge. The pump jet mixing modeling indicates that two 300-hp mixer pumps would mobilize up to about 23 ft (7.0 m) of the sludge nearest the pump but would not erode the waste within seven inches (0.18 m) of the tank bottom. This results in about half of the sludge being uniformly mixed in the tank and the other half being unmixed (not eroded) at the tank bottom.

Pump Jet Mixing and Pipeline Transfer Assessment for High-Activity Radioactive Wastes in Hanford Tank 241-AZ-102

International Nuclear Information System (INIS)

Onishi, Y.; Recknagle, K.P.; Wells, B.E.

2000-01-01

The authors evaluated how well two 300-hp mixer pumps would mix solid and liquid radioactive wastes stored in Hanford double-shell Tank 241-AZ-102 (AZ-102) and confirmed the adequacy of a three-inch (7.6-cm) pipeline system to transfer the resulting mixed waste slurry to the AP Tank Farm and a planned waste treatment (vitrification) plant on the Hanford Site. Tank AZ-102 contains 854,000 gallons (3,230 m 3 ) of supernatant liquid and 95,000 gallons (360 m 3 ) of sludge made up of aging waste (or neutralized current acid waste). The study comprises three assessments: waste chemistry, pump jet mixing, and pipeline transfer. The waste chemical modeling assessment indicates that the sludge, consisting of the solids and interstitial solution, and the supernatant liquid are basically in an equilibrium condition. Thus, pump jet mixing would not cause much solids precipitation and dissolution, only 1.5% or less of the total AZ-102 sludge. The pump jet mixing modeling indicates that two 300-hp mixer pumps would mobilize up to about 23 ft (7.0 m) of the sludge nearest the pump but would not erode the waste within seven inches (0.18 m) of the tank bottom. This results in about half of the sludge being uniformly mixed in the tank and the other half being unmixed (not eroded) at the tank bottom

The extrusion of AZ-series magnesium alloys - extending the processing limits by hydrostatic extrusion; Erweiterung der Prozessgrenzen beim Strangpressen von Magnesiumknetlegierungen der AZ-Reihe durch das hydrostatische Strangpressverfahren

Energy Technology Data Exchange (ETDEWEB)

Swiostek, J. [GKSS-Forschungszentrum Geesthacht GmbH (Germany). Inst. fuer Werkstofforschung

2008-12-04

The present study is concerned with the analysis of the influence of hydrostatic extrusion on the microstructural development and mechanical properties of extruded profiles of the AZ-series magnesium alloys. This work also deals with the correlation between the microstructure and resulting mechanical properties for the case extruded profiles. (orig.)

Cerium Addition Improved the Dry Sliding Wear Resistance of Surface Welding AZ91 Alloy

Directory of Open Access Journals (Sweden)

Qingqiang Chen

2018-02-01

Full Text Available In this study, the effects of cerium (Ce addition on the friction and wear properties of surface welding AZ91 magnesium alloys were evaluated by pin-on-disk dry sliding friction and wear tests at normal temperature. The results show that both the friction coefficient and wear rate of surfacing magnesium alloys decreased with the decrease in load and increase in sliding speed. The surfacing AZ91 alloy with 1.5% Ce had the lowest friction coefficient and wear rate. The alloy without Ce had the worst wear resistance, mainly because it contained a lot of irregularly shaped and coarse β-Mg17Al12 phases. During friction, the β phase readily caused stress concentration and thus formed cracks at the interface between β phase and α-Mg matrix. The addition of Ce reduced the size and amount of Mg17Al12, while generating Al4Ce phase with a higher thermal stability. The Al-Ce phase could hinder the grain-boundary sliding and migration and reduced the degree of plastic deformation of subsurface metal. Scanning electron microscopy observation showed that the surfacing AZ91 alloy with 1.5% Ce had a total of four types of wear mechanism: abrasion, oxidation, and severe plastic deformation were the primary mechanisms; delamination was the secondary mechanism.

Flow behaviour of magnesium alloy AZ31B processed by equal-channel angular pressing

International Nuclear Information System (INIS)

Arun, M S; Chakkingal, U

2014-01-01

Magnesium alloys are characterised by their low density, high specific strength and stiffness. But, the potential application of Mg is limited by its low room-temperature ductility and formability. Formability can be improved by developing an ultrafine grained (UFG) structure. Equal channel angular pressing (ECAP) is a well known process that can be used to develop an ultrafine grained microstructure. The aim of this study was to investigate the flow behaviour of AZ31B magnesium alloy after ECAP. The specimen was subjected to three passes of ECAP with a die angle of 120° using processing route Bc. The processing temperature was 523 K for the first pass and 423 K for the subsequent two passes. The microstructure characterisation was done. Compression tests of ECAPed and annealed specimens were carried out at strain rates of 0.01 – 1s −1 and deformation temperatures of 200 – 300°C using computer servo-controlled Gleeble-3800 system. The value of activation energy Q and the empirical materials constants of A and n were determined. The equations relating flow stress and Zener-Hollomon parameter were proposed. In the case annealed AZ31, the activation energy was determined to be 154 kJ/mol, which was slightly higher than the activation energy of 144 kJ/mol for ECAPed AZ31

Flow behaviour of magnesium alloy AZ31B processed by equal-channel angular pressing

Science.gov (United States)

Arun, M. S.; Chakkingal, U.

2014-08-01

Magnesium alloys are characterised by their low density, high specific strength and stiffness. But, the potential application of Mg is limited by its low room-temperature ductility & formability. Formability can be improved by developing an ultrafine grained (UFG) structure. Equal channel angular pressing (ECAP) is a well known process that can be used to develop an ultrafine grained microstructure. The aim of this study was to investigate the flow behaviour of AZ31B magnesium alloy after ECAP. The specimen was subjected to three passes of ECAP with a die angle of 120° using processing route Bc. The processing temperature was 523 K for the first pass and 423 K for the subsequent two passes. The microstructure characterisation was done. Compression tests of ECAPed and annealed specimens were carried out at strain rates of 0.01 - 1s-1 and deformation temperatures of 200 - 300°C using computer servo-controlled Gleeble-3800 system. The value of activation energy Q and the empirical materials constants of A and n were determined. The equations relating flow stress and Zener-Hollomon parameter were proposed. In the case annealed AZ31, the activation energy was determined to be 154 kJ/mol, which was slightly higher than the activation energy of 144 kJ/mol for ECAPed AZ31.

Electrodeposition of Al-Mn alloy on AZ31B magnesium alloy in molten salts

International Nuclear Information System (INIS)

Zhang Jifu; Yan Chuanwei; Wang Fuhui

2009-01-01

The Al-Mn alloy coatings were electrodeposited on AZ31B Mg alloy in AlCl 3 -NaCl-KCl-MnCl 2 molten salts at 170 deg. C aiming to improve the corrosion resistance. However, in order to prevent AZ31B Mg alloy from corrosion during electrodeposition in molten salts and to ensure excellent adhesion of coatings to the substrate, AZ31B Mg alloy should be pre-plated with a thin zinc layer as intermediate layer. Then the microstructure, composition and phase constituents of the coatings were investigated by scanning electron microscopy (SEM), energy-dispersive X-ray spectrometry (EDX), and X-ray diffraction (XRD). It was indicated that, by adjusting the MnCl 2 content in the molten salts from 0.5 wt% to 2 wt%, the Mn content in the alloy coating was increased and the phase constituents were changed from f.c.c Al-Mn solid solution to amorphous phase. The corrosion resistance of the coatings was evaluated by potentiodynamic polarization measurements in 3.5% NaCl solution. It was confirmed that the Al-Mn alloy coatings exhibited good corrosion resistance with a chear passive region and significantly reduced corrosion current density at anodic potentiodynamic polarization. The corrosion resistance of the alloy coatings was also related with the microstructure and Mn content of the coatings.

Complicaciones maternas de la cesárea en gestantes a término en periodo expulsivo en un hospital general de Lima, Perú

Directory of Open Access Journals (Sweden)

Javier Puma

2015-01-01

Full Text Available Objetivo: Describir las complicaciones maternas de la cesárea en gestantes a término en periodo expulsivo en un hospital general. Material y métodos: Estudio descriptivo, observacional, retrospectivo, tipo serie de casos, realizado en el Hospital Nacional Cayetano Heredia entre el 1 de enero de 2011 hasta el 31 diciembre de 2012. Se incluyeron 67 gestantes a término operadas en periodo expulsivo. Se revisaron las historias clínicas de las pacientes, se registraron las características clínicas y las complicaciones maternas. Resultados: En el periodo de estudio se realizaron 4 218 cesáreas, siendo el 1,84% hechas en periodo expulsivo. En general, 59/ 67 (88,1% presentaron algún tipo de complicación. Se observaron 8 casos de hipotonía uterina (11,9% y 2 (2,9% de atonía. En 5 (7,4% pacientes ocurrieron desgarros de segmento adyacente a la histerotomía, siendo 2 de ellos asociados a compromiso de cuerpo uterino y vagina, y 4 (5,9% casos a laceración de arteria uterina, uno fue bilateral. No se produjeron lesiones en tracto urinario ni digestivo y tampoco hubo necesidad de reintervención quirúrgica. Cuatro pacientes presentaron hemorragia puerperal, dos asociados a hipotonía uterina post cesárea. En 56 (83,5% casos ocurrió anemia post operatoria. Hubo 1 (1,5% caso de endometritis, 3 (4,5% infecciones de herida operatoria. Conclusiones: La cesárea realizada en período expulsivo ocasiona complicaciones frecuentes, algunas muy severas.

Empleo y salarios en argentina en el periodo de la Post-Convertibilidad

Directory of Open Access Journals (Sweden)

Nilson Javier Ibagón Martín

2015-03-01

Full Text Available El Articulo analiza los procesos de precarización laboral que se han dado en Argentina a la largo de los últimos 25 años, haciendo  especial énfasis en el llamado periodo de “post-convertibilidad” o “dólar alto”. En este sentido, se estudia para dicho periodo, la existencia de una serie de continuidades económicas y sociales  heredadas de la década del noventa, las cuales, ponen de manifiesto una serie de estrategias y políticas empleadas por parte de los sectores económicos dominantes, que les han permitido en buena parte, por un lado, transferir a las trabajadores los costos de las crisis económicas, y por otro, frenar el acceso de estos últimos a una             redistribución de la riqueza en tiempos de bonanza y crecimiento.Palabras clave: Empleo; Salarios bajos; Política Monetaria; Desindustrialización; Política Industrial. Employment and wages in argentina in the period of Post-ConvertibilityAbstract Article analyzes the processes of labor precariousness that have occurred in Argentina during the last 25 years, with particular emphasis in the period of “post-convertibility” or “high dollar”. In this direction, the existence of a number of inherited continuities of the nineties is studied. These legacies reveal a series of strategies and policies used by the dominant economic sectors, that have allowed them, on the one hand, transfer the costs of the economic crisis on workers, and secondly, curb the access of this group to a redistribution of wealth in good times and growth.Keywords: Employment; Low Wage; Monetary Policy; Deindustrialization; Industrial Policy.

Laser cladding of Zr-based coating on AZ91D magnesium alloy for ...

Indian Academy of Sciences (India)

based coating made of Zr powder was fabricated on AZ91D magnesium alloy by laser cladding. The microstructure of the coating was characterized by XRD, SEM and TEM techniques. The wear resistance of the coating was evaluated under dry ...

241-AZ-101 Waste Tank Color Video Camera System Shop Acceptance Test Report

Energy Technology Data Exchange (ETDEWEB)

WERRY, S.M.

2000-03-23

This report includes shop acceptance test results. The test was performed prior to installation at tank AZ-101. Both the camera system and camera purge system were originally sought and procured as a part of initial waste retrieval project W-151.

241-AZ-101 Waste Tank Color Video Camera System Shop Acceptance Test Report

International Nuclear Information System (INIS)

WERRY, S.M.

2000-01-01

This report includes shop acceptance test results. The test was performed prior to installation at tank AZ-101. Both the camera system and camera purge system were originally sought and procured as a part of initial waste retrieval project W-151

The Corrosion Protection of Magnesium Alloy AZ31B

Science.gov (United States)

Danford, M. D.; Mendrek, M. J.; Mitchell, M. L.; Torres, P. D.

1997-01-01

Corrosion rates for bare and coated Magnesium alloy AZ31B have been measured. Two coatings, Dow-23(Trademark) and Tagnite(Trademark), have been tested by electrochemical methods and their effectiveness determined. Electrochemical methods employed were the scanning reference electrode technique (SRET), the polarization resistance technique (PR) and the electrochemical impedance spectroscopy technique (EIS). In addition, general corrosion and stress corrosion methods were employed to examine the effectiveness of the above coatings in 90 percent humidity. Results from these studies are presented.

Dry Sliding Wear Charactristics of Aluminum 6061-T6, Magnesium AZ31 and Rock Dust Composite

Science.gov (United States)

Balachandar, R.; Balasundaram, R.; Rajkumar, G.

2018-02-01

In recent years, the use of aluminum composite is gaining popularity in a wide range of applications like automobiles, aerospace and constructions (both interior & exterior) panels etc., due to its high strength, low density characteristics. Various reinforcing materials are used with aluminum 6061-T6 in order to have better mechanical properties. The addition of 0.3% of magnesium AZ31 will increase the ultimate tensile strength by 25 %. The reinforcement of rock dust will decrease the density. Hence, in order to have an advantages of magnesium AZ31 and rock dust, in this work, these two constitutes are varied from 1% to 2% on the base material of Al6061-T6 in stir casting. To evaluate the wear characteristics, Pin on disc is used in these composites. The input parameters are speed, time & load. The output response is wear. To minimize the number of experiments, L9 orthogonal array is used. The test results showed that a composite of 97% of Al (6061-T6), 1% Mg (AZ31) & 2 % of rock dust produced less wear. To find the best value of operating parameter for each sample, ANN-GA is used.

12 CFR 516.140 - How long is the comment period?

Science.gov (United States)

2010-01-01

... 12 Banks and Banking 5 2010-01-01 2010-01-01 false How long is the comment period? 516.140 Section 516.140 Banks and Banking OFFICE OF THRIFT SUPERVISION, DEPARTMENT OF THE TREASURY APPLICATION PROCESSING PROCEDURES Comment Procedures § 516.140 How long is the comment period? (a) General. Except as...

Project W-314 specific test and evaluation plan for AZ tank farm upgrades

International Nuclear Information System (INIS)

Hays, W.H.

1998-01-01

The purpose of this Specific Test and Evaluation Plan (STEP) is to provide a detailed written plan for the systematic testing of modifications made by the addition of the SN-631 transfer line from the AZ-O1A pit to the AZ-02A pit by the W-314 Project. The STEP develops the outline for test procedures that verify the system's performance to the established Project design criteria. The STEP is a lower tier document based on the W-314 Test and Evaluation P1 an (TEP). Testing includes Validations and Verifications (e.g., Commercial Grade Item Dedication activities, etc), Factory Tests and Inspections (FTIs), installation tests and inspections, Construction Tests and Inspections (CTIs), Acceptance Test Procedures (ATPs), Pre-Operational Test Procedures (POTPs), and Operational Test Procedures (OTPs). The STEP will be utilized in conjunction with the TEP for verification and validation

El blocao (y el bloqueo de José Díaz Fernández

Directory of Open Access Journals (Sweden)

Luis Fernando Bueno Morillas

2015-06-01

Full Text Available El blocao (1928 fue la primera novela de José Díaz Fernández. Supuso un éxito editorial insólito hasta entonces porque reunía tres características novedosas: una actitud crítica ante la guerra de Marruecos, una integración de las novedades vanguardistas en la que su autor llamó literatura de avanzada y un posicionamiento del intelectual al lado de las reivindicaciones del pueblo. Sin embargo, aunque publicó otra novela un año después (La Venus mecánica, un libro teórico en el que definía la literatura que él propugnaba y practicaba (El nuevo romanticismo y algunas narraciones breves, Díaz Fernández se bloqueó y dejó la literatura narrativa que tan buenas expectativas levantó. Analizaremos las posibles causas de ese bloqueo.

El medievalismo fértil de Paloma Díaz-Mas

Directory of Open Access Journals (Sweden)

Rafael M. Mérida Jiménez

2001-01-01

Full Text Available The author of this article is concerned with trying to understand why Paloma Díaz-Mas, the writer of such an excellent novel as La tierra fértil (1999, has not received much critical attention. He underlines three main reasons. First, she does not live in Madrid or Barcelona and so she is far away from the main centres of cultural power. Second, she teaches Spanish literature in the Basque Country, a political and linguistic community which significantly differs from that of many other writers. Third, she writes historical novels, which does not appear to be very fashionable in Spain these days. Moreover, Díaz-Mas is a woman writer who does not make use of the most commonly available feminine patterns, and she does not seem to offer a model easy to include in a given feminist methodology either. However, Mérida-Jiménez argues that Paloma provides an intelligent deconstruction of “male authority” through subtle rhetorical means, as well as a representation of the weakness of his “domination” in very innovative ways, such as those derived from the dialectics between history and fiction, centrality and marginality, heterosexuality and homosexuality, individual and society, dream and reason or tradition and modernity.

Las juntas directivas en la capitalización de empresas en Colombia para el periodo 1956-1973

OpenAIRE

Castellanos Cabrera, Germán Andrés

2015-01-01

El presente documento realiza una descripción de como estaban estructuradas las juntas directivas de las principales empresas del país para el periodo de 1956 a 1957. De manera simultánea, se lleva a cabo un cuidadoso análisis, junto con un ejercicio comparativo, de si estas estructuras estaban en acorde a lo que sugiere la literatura acerca de la Gobernanza Corporativa.

30 CFR 62.140 - Dual hearing protection level.

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Dual hearing protection level. 62.140 Section... HEALTH REGULATIONS OCCUPATIONAL NOISE EXPOSURE § 62.140 Dual hearing protection level. If during any work shift a miner's noise exposure exceeds the dual hearing protection level, the mine operator must, in...

¿ES ÚTIL EL ANÁLISIS TÉCNICO EN PERIODOS DE CRISIS FINANCIERA? Evidencia para el mercado bursátil latinoamericano

Directory of Open Access Journals (Sweden)

Christian Espinosa

2014-01-01

Full Text Available En este artículo investigamos si los instrumentos de análisis técnico son útiles en periodos de crisis financieras. Considerando cuatro de los principales índices latinoamericanos —Bovespa (Brasil, IGBLV (Perú, IPC (México e IPSA (Chile— no encontramos Considerando cuatro de los principales índices latinoamericanos —Bovespa (Brasil, IGBLV (Perú, IPC (México e IPSA (Chile— no encontramos evidencia a favor del uso de análisis técnico en periodos de crisis financiera. Las técnicas que otorgan rentabilidades más altas no son las mismas que reportan rendimientos más bajos. En general, los instrumentos de mediano plazo son los que reportan un mayor rendimiento, mientras que los de corto plazo reportan un menor rendimiento.

25 CFR 140.23 - Credit at trader's risk.

Science.gov (United States)

2010-04-01

... 25 Indians 1 2010-04-01 2010-04-01 false Credit at trader's risk. 140.23 Section 140.23 Indians....23 Credit at trader's risk. Credit given Indians will be at the trader's own risk, as no assistance... accept pawns or pledges of personal property by Indians to obtain credit or loans. ...

Cambio generacional del consumo de frutas y verduras en México a través de un análisis de edad-periodo-cohorte 1994-2014

Directory of Open Access Journals (Sweden)

Fabiola LópezGonzález

2018-01-01

Full Text Available Objetivo: Cuantificar el cambio en el consumo de frutas y verduras en México entre 1994 y 2014, identificar su tendencia en el tiempo y segmentar el grupo de hogares por nivel de consumo, según la edad de la cabeza del hogar, con la intención de comprender la evolución del consumo de frutas y verduras de la población mexicana. Material y métodos: Se utilizaron datos sobre gasto en frutas y verduras, provenientes de la Encuesta Nacional de Ingreso y Gasto en Hogares de 1994 a 2014; se realizó una prueba F sobre el consumo per cápita para identificar si el incremento es significativo y se llevó a cabo la modelación edad-cohorte-periodo de esta misma variable para anticipar cambios a largo plazo. Resultados: Los hábitos de compra de frutas y verduras entre 1994 y 2014 reflejan un incremento en el consumo de estos alimentos de 60 gramos (30.3% en el periodo de observación. Se encontraron efectos edad-cohorte-periodo y una relación positiva entre el consumo de frutas y verduras y la edad. Conclusiones: El consumo de frutas y verduras se incrementó en forma significativa durante el periodo estudiado; se espera que continúe al alza como consecuencia del envejecimiento poblacional. Es necesario aumentar el consumo de estos alimentos en los jóvenes a fin de prevenir el desarrollo de padecimientos crónicos.

Role of manganese on the grain refining efficiency of AZ91D magnesium alloy refined by Al4C3

International Nuclear Information System (INIS)

Liu Shengfa; Zhang Yuan; Han Hui

2010-01-01

A novel Mg-50% Al 4 C 3 (hereafter in wt.%) master alloy has been developed by powder in situ synthesis process, the role of manganese on the grain refining efficiency of AZ91D magnesium alloy refined by this master alloy has been investigated. X-ray diffraction (XRD) and energy dispersive X-ray spectroscopy (EDS) results show the existence of Al 4 C 3 particles in this master alloy. After addition of 0.6% Al 4 C 3 or combined addition of 0.6% Al 4 C 3 and 0.27% Mn, the average grain size of AZ91D decreased dramatically from 360 μm to 210 μm, and from 360 μm to130 μm, respectively. However, no further refinement of grain size was achieved with additional amount of Mn exceeding 0.27% for AZ91D alloy refined by 0.6% Al 4 C 3 in the present investigation. Al-C-O-Mn-Fe-rich intermetallic particles with an Al-C-O-rich coating film, often observed in the central region of magnesium grains of the AZ91D alloy treated by the combination of Al 4 C 3 and Mn, are proposed to be the potent nucleating substrates for primary α-Mg.

47 CFR 25.140 - Qualifications of fixed-satellite space station licensees.

Science.gov (United States)

2010-10-01

... 47 Telecommunication 2 2010-10-01 2010-10-01 false Qualifications of fixed-satellite space station licensees. 25.140 Section 25.140 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES SATELLITE COMMUNICATIONS Applications and Licenses Space Stations § 25.140 Qualifications...

Surface characterization and cytocompatibility evaluation of silanized magnesium alloy AZ91 for biomedical applications

Directory of Open Access Journals (Sweden)

Agnieszka Witecka, Akiko Yamamoto, Henryk Dybiec and Wojciech Swieszkowski

2012-01-01

Full Text Available Mg alloys with high Al contents have superior corrosion resistance in aqueous environments, but poor cytocompatibility compared to that of pure Mg. We have silanized the cast AZ91 alloy to improve its cytocompatibility using five different silanes: ethyltriethoxysilane (S1, 3-aminopropyltriethoxysilane (S2, 3-isocyanatopyltriethoxysilane (S3, phenyltriethoxysilane (S4 and octadecyltriethoxysilane (S5. The surface hydrophilicity/hydrophobicity was evaluated by water contact angle measurements. X-ray photoelectron analysis was performed to investigate the changes in surface states and chemical composition. All silane reagents increased adsorption of the albumin to the modified surface. In vitro cytocompatibility evaluation revealed that silanization improved cell growth on AZ91 modified by silane S1. Measurement of the concentration of Mg2+ ions released during the cell culture indicated that silanization does not affect substrate degradation.

High performance corrosion and wear resistant composite titanium nitride layers produced on the AZ91D magnesium alloy by a hybrid method

Directory of Open Access Journals (Sweden)

Michał Tacikowski

2014-09-01

Full Text Available Composite, diffusive titanium nitride layers formed on a titanium and aluminum sub-layer were produced on the AZ91D magnesium alloy. The layers were obtained using a hybrid method which combined the PVD processes with the final sealing by a hydrothermal treatment. The microstructure, resistance to corrosion, mechanical damage, and frictional wear of the layers were examined. The properties of the AZ91D alloy covered with these layers were compared with those of the untreated alloy and of some engineering materials such as 316L stainless steel, 100Cr6 bearing steel, and the AZ91D alloy subjected to commercial anodizing. It has been found that the composite diffusive nitride layer produced on the AZ91D alloy and then sealed by the hydrothermal treatment ensures the corrosion resistance comparable with that of 316L stainless steel. The layers are characterized by higher electrochemical durability which is due to the surface being overbuilt with the titanium oxides formed, as shown by the XPS examinations, from titanium nitride during the hydrothermal treatment. The composite titanium nitride layers exhibit high resistance to mechanical damage and wear, including frictional wear which is comparable with that of 100Cr6 bearing steel. The performance properties of the AZ91D magnesium alloy covered with the composite titanium nitride coating are substantially superior to those of the alloy subjected to commercial anodizing which is the dominant technique employed in industrial practice.

Laser cladding of Zr-based coating on AZ91D magnesium alloy for ...

Indian Academy of Sciences (India)

3Hubei Key Laboratory of Hydroelectric Machinery Design & Maintenance, ... To improve the wear and corrosion resistance of AZ91D magnesium alloy, Zr-based coating made of ... process that lead to inflammatory cascades which reduce bio- ... tions regarding their application as protective films on load- ... Experimental.

Sealing of PEO Coated AZ91 Magnesium Alloy Using La-Based Solutions

Directory of Open Access Journals (Sweden)

Luca Pezzato

2017-01-01

Full Text Available In this work, solutions containing lanthanum salts were used for a post-treatment of sealing to increase the corrosion resistance of PEO coated AZ91 alloy. PEO coatings were produced on samples of AZ91 magnesium alloy using an alkaline solution containing sodium hydroxide, sodium phosphates, and sodium silicates. The sealing treatment was performed in a solution containing 12 g/L of La(NO33 at pH 4 at different temperatures and for different treatment times. Potentiodynamic polarization test, an EIS test, showed that the sealing treatment with solution containing lanthanum nitrate caused a remarkable increase in the corrosion resistance. The corrosion behavior was correlated with the surface morphology and elemental composition evaluated with scanning electron microscope (SEM, X-ray diffraction (XRD, and X-ray photoelectron spectroscopy (XPS. In particular, the sealing treatment at 50°C for 30 min resulted in being the most promising to increase the corrosion properties of PEO treated samples because of the formation of a homogeneous sealing layer, mainly composed of La(OH3.

Surface roughness optimization in machining of AZ31 magnesium alloy using ABC algorithm

Directory of Open Access Journals (Sweden)

Abhijith

2018-01-01

Full Text Available Magnesium alloys serve as excellent substitutes for materials traditionally used for engine block heads in automobiles and gear housings in aircraft industries. AZ31 is a magnesium alloy finds its applications in orthopedic implants and cardiovascular stents. Surface roughness is an important parameter in the present manufacturing sector. In this work optimization techniques namely firefly algorithm (FA, particle swarm optimization (PSO and artificial bee colony algorithm (ABC which are based on swarm intelligence techniques, have been implemented to optimize the machining parameters namely cutting speed, feed rate and depth of cut in order to achieve minimum surface roughness. The parameter Ra has been considered for evaluating the surface roughness. Comparing the performance of ABC algorithm with FA and PSO algorithm, which is a widely used optimization algorithm in machining studies, the results conclude that ABC produces better optimization when compared to FA and PSO for optimizing surface roughness of AZ 31.

Auditoría financiera y tributaria a la empresa Fideos Paraíso, periodo fiscal 2013

OpenAIRE

Cusco Quinde, Ana Jackeline

2014-01-01

El documento consiste en una Auditoría Financiera y Tributaria a la Empresa Fideos Paraíso, periodo fiscal 2013; obteniendo como resultado, luego del análisis, un informe de auditoría con salvedades en la parte contable-financiera y tributaria. The document is a Financial and Tax Audit Company Fideos Paraíso, fiscal year 2013; resulting in, after the analysis, a qualified audit report on the financial and tax accounting part.

Study on fluidity of squeeze cast AZ91D magnesium alloy with different wall thicknesses

Directory of Open Access Journals (Sweden)

Chen Yun

2014-03-01

Full Text Available Rectangular cross-section specimens with different section thicknesses were prepared to study the influences of pouring temperature, mould temperature and squeeze velocity on the fluidity of squeeze cast AZ91D magnesium alloy by means of orthogonal test design method. The results show that pouring temperature, mould temperature and squeeze velocity can significantly affect the fluidity of magnesium alloy specimens with wall thickness no more than 4 mm, and the pouring temperature is the most influential factor on the fluidity of specimens with wall thickness of 1, 2 and 3 mm, while mould temperature is the one for specimens with wall thickness of 4 mm. Increasing pouring temperature between 700 °C and 750 °C is beneficial to the fluidity of AZ91D magnesium alloy, and increasing mould temperature significantly enhances the filling ability of thick (3 and 4 mm section castings. The fluidity of squeeze cast magnesium alloy increases with the increase of wall thickness. It is not recommended to produce magnesium alloy casting with wall thickness of smaller than 3 mm by squeeze cast process due to the poor fluidity. The software DPS was used to generate the regression model, and linear regression equations of the fluidity of squeeze cast AZ91D with different wall thicknesses are obtained using the test results.

Structural and electrochemical behavior of sol-gel ZrO2 ceramic film on chemically pre-treated AZ91D magnesium alloy

International Nuclear Information System (INIS)

Li Qing; Chen Bo; Xu Shuqiang; Gao Hui; Zhang Liang; Liu Chao

2009-01-01

In the present investigation sol-gel-based ZrO 2 ceramic film was obtained using zirconium acetate as the precursor material. The film was deposited on AZ91D magnesium alloy by a dip-coating technique. An uniform stannate conversion coating as chemical pretreatment was employed as an intermediate layer prior to deposition of the ZrO 2 film in order to provide advantage for the formation of sol-gel-based ZrO 2 layer. The corrosion properties, structure, composition and morphology of these coatings on AZ91D magnesium alloy were studied by potentiodynamic polarization tests, EIS, XRD, SEM, respectively. According to the electrochemical tests, the corrosion resistance of AZ91D magnesium alloy was found to be greatly improved by means of this new environment-friendly surface treatment.

Fatigue properties of magnesium alloy AZ91 processed by severe plastic deformation

Czech Academy of Sciences Publication Activity Database

Fintová, Stanislava; Kunz, Ludvík

2015-01-01

Roč. 42, FEB (2015), s. 219-228 ISSN 1751-6161 R&D Projects: GA ČR GAP108/10/2001 Institutional support: RVO:68081723 Keywords : AZ91 magnesium alloy * ECAP * Fatigue * Crack initiation Subject RIV: JL - Materials Fatigue, Friction Mechanics Impact factor: 2.876, year: 2015 http://www.sciencedirect.com/science/article/pii/S1751616114003713

Evaluation of waste temperatures in AWF tanks for bypass mode operation of the 702-AZ ventilation system (Project W-030)

International Nuclear Information System (INIS)

Sathyanarayana, K.

1997-01-01

This report describes the results of thermal hydraulic analysis performed to provide data in support of Project W-030 to startup new 702-AZ Primary Ventilation System. During the startup of W-030 system, the ventilation system will be operating in bypass mode. In bypass made of operation, the system is capable of supplying 1000 cfm total flow for all four AWF doubleshell tanks. The design of the W-030 system is based on the assumption that both the recirculation loop of the primary ventilation system and the secondary ventilation which provides cooling would be operating. However, during the startup neither the recirculation system nor the secondary ventilation system will be operating. A minimum flow of 100 cfm is required to prevent any flammable gas associated risk. The remaining 600 cfm flow can be divided among the four tanks as necessary to keep the peak sludge temperatures below the operating temperature limit. For the purpose of determining the minimum flow required for cooling each tank, the thermal hydraulic analysis is performed to predict the peak sludge temperatures in AY/AZ tanks under different ventilation flows. The heat load for AZ farm tanks is taken from characterization reports and for the AY farm tanks, the heat load was estimated by thermal analysis using the measured waste temperatures and the waste liquid evaporation rates. The tank 241-AZ-101 and the tank 241-AZ-102 have heat loads of 241,600 and 199,500 Btu/hr respectively. The tank 241-AY-101 and tank 241-AY-102 have heat loads of 41,000 and 33,000 Btu/hr respectively. Using the ambient meteorological conditions of temperature and relative humidity for the air and tank, some soil surface and the sludge levels reported in recent documents, the peak sludge and supernatant temperatures were predicted for various primary ventilation flows ranging from 100 to 400 cfm for AZ tanks and 100 and 150 cfm for AY tanks. The results of these thermal hydraulic analyses are presented. Based on the

40 CFR 421.140 - Applicability: Description of the primary antimony subcategory.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 28 2010-07-01 2010-07-01 true Applicability: Description of the primary antimony subcategory. 421.140 Section 421.140 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS NONFERROUS METALS MANUFACTURING POINT SOURCE CATEGORY Primary Antimony Subcategory § 421.140...

An electron back-scattered diffraction study on the microstructure evolution of AZ31 Mg alloy during equal channel angular extrusion

International Nuclear Information System (INIS)

Jin Li; Lin Dongliang; Mao Dali; Zeng Xiaoqin; Ding Wenjiang

2006-01-01

Microstructure evolution of AZ31 Mg alloy during equal channel angular extrusion (ECAE) was investigated by electron back-scattered diffraction (EBSD). The grains of AZ31 Mg alloy were refined significantly after ECAE 1-8 passes at 498 K and the distributions of grain size tended to be more uniform with pass number increasing. Frequency of sub-boundaries and low angle grain boundaries (LAGBs) increased at initial stage of deformation, and sub-boundaries and LAGBs evolved into high angle grain boundaries (HAGBs) with further deformation, which resulted in the high frequency of HAGBs in the alloy after ECAE 8 passes. Preferred misorientation angle with frequency peak near 30 deg. and 90 deg. were observed. The frequency peaks were weak after ECAE 1 pass but became stronger with the increase of pass numbers. Micro-textures were formed in AZ31 microstructure during ECAE and were stronger with the pass number increasing

The effect of Ca and RE elements on the precipitation kinetics of Mg17Al12 phase during artificial aging of magnesium alloy AZ91

International Nuclear Information System (INIS)

Amir Esgandari, B.; Mehrjoo, H.; Nami, B.; Miresmaeili, S.M.

2011-01-01

Highlights: → Ca and RE elements decrease the precipitation rate during aging of AZ91 alloy. → Precipitation kinetics and mechanism during aging of the alloys were studied. → Effect of Ca and RE on creep properties of age hardened AZ91 alloy was studied. - Abstract: The effect of simultaneous alloying with Ca and rare earth (RE) elements on the age hardening kinetics of AZ91 was studied through the fitting of the Johnson-Mehl-Avrami (JMA) equation. The results showed that the addition of both Ca and RE elements not only suppress discontinuous precipitation of the Mg 17 Al 12 phase during the age hardening process, but also decrease the alloy hardness. Fitting the JMA equation to the experimental data indicated that the phase transformation during age hardening of an alloy variant containing both Ca and RE (at 170 deg. C and 190 deg. C) and standard AZ91 (at 170 deg. C) takes place by the nucleation of precipitates on dislocations. In contrast, the precipitation during age hardening of AZ91 at 190 deg. C occurs via nucleation at grain boundaries. Although it was observed that the creep strength of age hardened specimens are lower than that of the as cast specimens, but age hardening treatment has lower deleterious influence on the creep resistance of the alloy containing Ca and RE in comparison with conventional AZ91. This may be ascribed to the decreased precipitation rate resulting from the addition of both Ca and RE elements.

Corrosion performance of MAO coatings on AZ31 Mg alloy in simulated body fluid vs. Earle's Balance Salt Solution

Energy Technology Data Exchange (ETDEWEB)

Wilke, Benjamin M. [Department of Mechanical Engineering, PO Box 755905, University of Alaska Fairbanks, Fairbanks, AK 99775 (United States); Zhang, Lei, E-mail: lzhang14@alaska.edu [Department of Mechanical Engineering, PO Box 755905, University of Alaska Fairbanks, Fairbanks, AK 99775 (United States); Li, Weiping; Ning, Chengyun [School of Materials Science and Engineering, South China University of Technology, Guangzhou 510641 (China); Chen, Cheng-fu [Department of Mechanical Engineering, PO Box 755905, University of Alaska Fairbanks, Fairbanks, AK 99775 (United States); Gu, Yanhong [College of Mechanical Engineering, Beijing Institute of Petrochemical Technology, Beijing 102617 (China)

2016-02-15

Graphical abstract: - Highlights: • MAO coating is deposited on AZ31 Mg alloy by microarc oxidation. • Corrosion performance of MAO-coated AZ31 in EBSS vs. c-SBF is studied. • MAO-coated AZ31 exhibits enhanced corrosion resistance compared to bare AZ31. • Samples in EBSS show slower corrosion progression than the samples in c-SBF. • CO{sub 2} buffer and less chloride in EBSS cause corrosion rate gap in c-SBF and EBSS. - Abstract: Earle's Balance Salt Solution (EBSS) provides an alternative to the conventional simulated body fluids (c-SBF) and has been shown to better simulate the corrosion conditions in vivo. In this work, a series of tests were conducted to explore the corrosion performance of MAO-coated AZ31 samples in EBSS vs. c-SBF. Samples were produced by varying MAO process parameters and then immersed up to 21 days in both EBSS and c-SBF. The corrosion rates were evaluated by the electrochemical impedance spectroscopy and potentiodynamic scanning. Scanning electron microscope (SEM) was used to compare the progression of microcracks across the surface of the coatings. The evaluation of cross-sectional thickness showed an increase in MAO coating thickness with the process voltage. MAO samples with a thicker coating generally have higher impedance and lower current density at the initial immersion time point of 0.5 h. Samples in EBSS showed higher initial impedance and lower current density values as compared to c-SBF counterparts for all process groups. Samples in EBSS demonstrated a much slower corrosion rate than c-SBF samples because of the decreased chloride content and CO{sub 2} buffering mechanism of the EBSS.

Corrosion performance of MAO coatings on AZ31 Mg alloy in simulated body fluid vs. Earle's Balance Salt Solution

International Nuclear Information System (INIS)

Wilke, Benjamin M.; Zhang, Lei; Li, Weiping; Ning, Chengyun; Chen, Cheng-fu; Gu, Yanhong

2016-01-01

Graphical abstract: - Highlights: • MAO coating is deposited on AZ31 Mg alloy by microarc oxidation. • Corrosion performance of MAO-coated AZ31 in EBSS vs. c-SBF is studied. • MAO-coated AZ31 exhibits enhanced corrosion resistance compared to bare AZ31. • Samples in EBSS show slower corrosion progression than the samples in c-SBF. • CO 2 buffer and less chloride in EBSS cause corrosion rate gap in c-SBF and EBSS. - Abstract: Earle's Balance Salt Solution (EBSS) provides an alternative to the conventional simulated body fluids (c-SBF) and has been shown to better simulate the corrosion conditions in vivo. In this work, a series of tests were conducted to explore the corrosion performance of MAO-coated AZ31 samples in EBSS vs. c-SBF. Samples were produced by varying MAO process parameters and then immersed up to 21 days in both EBSS and c-SBF. The corrosion rates were evaluated by the electrochemical impedance spectroscopy and potentiodynamic scanning. Scanning electron microscope (SEM) was used to compare the progression of microcracks across the surface of the coatings. The evaluation of cross-sectional thickness showed an increase in MAO coating thickness with the process voltage. MAO samples with a thicker coating generally have higher impedance and lower current density at the initial immersion time point of 0.5 h. Samples in EBSS showed higher initial impedance and lower current density values as compared to c-SBF counterparts for all process groups. Samples in EBSS demonstrated a much slower corrosion rate than c-SBF samples because of the decreased chloride content and CO 2 buffering mechanism of the EBSS.

La Caña de Azúcar y sus Derivados en la Huasteca San Luís Potosí México

Directory of Open Access Journals (Sweden)

Noé Aguilar Rivera

2011-08-01

Full Text Available La caña de azúcar es el principal cultivo de México, su cosecha se lleva a cabo en 665,000 ha que ocupan a 2.5 millones de personas. Existen 57 ingenios azucareros localizados en 15 estados de la republica. La industria ha cambiado dramáticamente desde la introducción de la caña de azúcar hace 486 años (año 1523 y su situación es reflejo de su metamorfosis y de intereses económicos y políticos. Fueron los españoles quienes introdujeron la caña de azúcar y tomaron así ventajas de las condiciones favorables que México ofrecía para el cultivo y la comercialización de los productos de derivados de la caña de azúcar (melazas, azúcar, panela o piloncillo y aguardiente. Grandes plantaciones fueron establecidas en diversas áreas como la Huasteca Potosina (San Luis Potosí. Esas plantaciones modificaron no solo las condiciones de vida, además la constitución de cada una de esas sociedades. El cambio fue dramático debido a la gran cantidad de indígenas nativos y al interés de los españoles hacia otras mercancías como los minerales y otros cultivos. En este trabajo se presentan algunos aspectos de la evolución y las estrategias para el desarrollo de la industria azucarera en la Huasteca Potosina San Luis Potosí durante el Virreinato de Nueva España.

Effect of alternating voltage treatment on corrosion resistance of AZ91D magnesium alloy

Energy Technology Data Exchange (ETDEWEB)

Liu, X. [Corrosion and Protection Laboratory, Key Laboratory of Superlight Materials and Surface Technology (Harbin Engineering University), Ministry of Education, Harbin (China); Zhang, T.; Shao, Y.; Meng, G.; Wang, F. [Corrosion and Protection Laboratory, Key Laboratory of Superlight Materials and Surface Technology (Harbin Engineering University), Ministry of Education, Harbin (China); State Key Laboratory for Corrosion and Protection, Institute of Metal Research, Chinese Academy of Sciences, Shenyang (China)

2012-06-15

AZ91D magnesium alloy was treated by the alternating voltage (AV) treatment technique. The optimal AV-treatment parameters of the alloy were determined by orthogonal experiments. Polarization curve, electrochemical impedance spectroscopy (EIS), and scanning electrochemical microscopy (SECM) were used to understand the effect of AV-treatment on the corrosion resistance of the alloy. AFM, contact angle, and XPS were employed to investigate further the influence of AV-treatment on the properties of the surface film formed on the alloy after AV-treatment. The results showed that a uniform and stable film was formed and the corrosion resistance of AZ91D magnesium alloy was significantly improved after AV-treatment. This was caused by the noticeable change of the chemical structure and semi-conducting properties of the surface film after AV-treatment. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

5 CFR 185.140 - Stays ordered by the Department of Justice.

Science.gov (United States)

2010-01-01

... 5 Administrative Personnel 1 2010-01-01 2010-01-01 false Stays ordered by the Department of Justice. 185.140 Section 185.140 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS PROGRAM FRAUD CIVIL REMEDIES § 185.140 Stays ordered by the Department of Justice. If, at any time...

41 CFR 105-53.140 - Office of Operations and Industry Relations.

Science.gov (United States)

2010-07-01

... 41 Public Contracts and Property Management 3 2010-07-01 2010-07-01 false Office of Operations and Industry Relations. 105-53.140 Section 105-53.140 Public Contracts and Property Management Federal Property... FUNCTIONS Central Offices § 105-53.140 Office of Operations and Industry Relations. The Office of Operations...

[Construction and identification of Nogo extra cellular peptide residues 1-40 gene lentiviral vector].

Science.gov (United States)

Yuan, Haifeng; Song, Yueming; Liu, Hao; Zhou, Chunguang; Kong, Qingquan; Liu, Liming; Gong, Quan

2012-02-01

To construct a lentiviral expression vector carrying Nogo extra cellular peptide residues 1-40 (NEP1-40) and to obtain NEP1-40 efficient and stable expression in mammalian cells. The DNA fragment of NEP1-40 coding sequence was amplified by PCR with designed primer from the cDNA library including NEP1-40 gene, and then subcloned into pGC-FU vector with in-fusion technique to generate the lentiviral expression vector, pGC-FU-NEP1-40. The positive clones were screened by PCR and the correct NEP1-40 was confirmed by sequencing. Recombinant lentiviruses were produced in 293T cells after the cotransfection of pGC-FU-NEP1-40, and packaging plasmids of pHelper 1.0 and pHelper 2.0. Green fluorescent protein (GFP) expression of infected 293T cells was observed to evaluate gene delivery efficiency. NEP1-40 protein expression in 293T cells was detected by Western blot. The lentiviral expression vector carrying NEP1-40 was successfully constructed by GFP observation, and NEP1-40 protein expression was detected in 293T cells by Western blot. The recombinant lentivirus pGC-FU-NEP1-40 is successfully constructed and it lays a foundation for further molecular function study of NEP 1-40.

General profile of the nutrition surplus in Mexico from 1990-2013: An approach using the energy supplied by macronutrients and food groups

Directory of Open Access Journals (Sweden)

José Cutberto Hernández Ramírez

2016-12-01

Full Text Available En este texto se analiza la evolución del suministro excesivo de kilocalorías en México desde 1990 a 2013. Para cada año del periodo se estimó el requerimiento de energía y macronutrimentos de la población mexicana y se lo contrastó con el respectivo suministro per cápita para estimar la discrepancia entre requerimiento y suministro. Las discrepancias se analizaron como serie temporal. Así, el excedente energético osciló entre 700 y 800 kcal/día per cápita en todo el periodo y los azúcares-dulcificantes aportaron el mayor suministro energético por encima de su requerimiento. El exceso de lípidos se incrementó de modo intenso y constante principalmente por el aumento de lípidos de carne de aves de corral y cerdo. El exceso aportado por las bebidas alcohólicas tendió a polarizarse en el creciente consumo de cerveza. En suma, a partir de los azúcares-dulcificantes y la carne se tendió a configurar el suministro energético y su respectivo excedente. Esto tiene implicaciones directas en la prevalencia de enfermedades crónicas no transmisibles así como en el uso insostenible de la tierra, el agua y la energía.

Possibilities of 140Nd production by the VINCY cyclotron

International Nuclear Information System (INIS)

Comor, J.J.; Dakovic, M.

2000-01-01

Application of positron emission tomography (PET) in modern medical diagnosis relies on the application of short lived radionuclides 11 C, 13 N, 15 O and 18 F, presuming their production in the close vicinity of the PET camera. Application of long-lived positron emitters would enable the regional distribution of PET radiopharmaceuticals, which would significantly lower the price of PET diagnosis, as well as enable its application in fields currently inhibited by the short half-life of available positron emitters. One of the candidates for application in PET is the generator system 140 Nd/ 140 Pr, due to the long half-life of 140 Nd (3,37 days). Theoretical calculations confirm that this radionuclide can be produced with high yields by protons accelerated to energies bellow 30 MeV. Due to its optimal operating parameters, the VINCY Cyclotron could produce enough 140 Nd for its regional distribution to a number of PET centers (author)

Metallurgical bond between magnesium AZ91 alloy and aluminium plasma sprayed coatings

Czech Academy of Sciences Publication Activity Database

Kubatík, Tomáš František; Pala, Zdeněk; Neufuss, Karel; Vilémová, Monika; Mušálek, Radek; Stoulil, J.; Slepička, P.; Chráska, Tomáš

2015-01-01

Roč. 282, November (2015), s. 163-170 ISSN 0257-8972 R&D Projects: GA ČR(CZ) GP14-31538P Institutional support: RVO:61389021 Keywords : Plasma spraying * AZ91 magnesium alloy * Aluminium * Metallurgical bond * X-ray diffraction Subject RIV: JK - Corrosion ; Surface Treatment of Materials Impact factor: 2.139, year: 2015 http://www.sciencedirect.com/science/article/pii/S0257897215303297

Propuesta de un certificado de defunción para mejorar el registro y reporte de la muerte en el periodo perinatal

Directory of Open Access Journals (Sweden)

Contreras-Lemus Javier

2001-01-01

Full Text Available Objetivo. Analizar la forma en que se registran los nacimientos y la muerte en el periodo perinatal, en el Instituto Mexicano del Seguro Social (IMSS, y documentar si el registro de la muerte, en este periodo, es adecuado. Material y métodos. Entre enero y marzo de 2000, se aplicó una encuesta en las 37 delegaciones del IMSS, para conocer, del año 1999, el total de nacimientos vivos y muertos, las defunciones ocurridas antes del séptimo día, considerando su edad gestacional y peso al nacimiento. Con estos datos se analizó la mortalidad hebdomadal e infantil y se calcularon las tasas correspondientes, incluyendo o desagregando a los niños con o = 28 semanas de gestación. Antes de la primera semana de vida extrauterina fallecieron 4 556 niños, de los cuales 1 385 (30.4% pesaron http://www.insp.mx/salud/index.html

Flow mechanisms in creep of a short-fibre AZ91 alloy-based composite

Czech Academy of Sciences Publication Activity Database

Pahutová, Marie; Sklenička, Václav; Kuchařová, Květa; Svoboda, Milan; Langdon, T. G.

43 2005, č. 1 (2005), s. 34-44 ISSN 0023-432X R&D Projects: GA ČR(CZ) GA106/03/0901 Institutional research plan: CEZ:AV0Z20410507 Keywords : AZ91 magnesium alloy * metal matrix composite * short fibre reinforcement Subject RIV: JG - Metallurgy Impact factor: 0.973, year: 2005

Fault-tolerant epoxy-silane coating for corrosion protection of magnesium alloy AZ31

NARCIS (Netherlands)

Lamaka, S.V.; Xue, H.B.; Meis, N.N.A.H.; Esteves, A.C.C.; Ferreira, M.G.S.

2015-01-01

In this work, a hybrid epoxy-silane coating was developed for corrosion protection of magnesium alloy AZ31. The average thickness of the film produced by dip-coating procedure was 14 µm. The adhesion strength of the epoxy-silane coating to the Mg substrate was evaluated by pull-off tests and was

Thermal Microstructural Stability of AZ31 Magnesium after Severe Plastic Deformation

Energy Technology Data Exchange (ETDEWEB)

Young, John P.; Askari, Hesam A.; Hovanski, Yuri; Heiden, Michael J.; Field, David P.

2015-03-01

Both equal channel angular pressing and friction stir processing have the ability to refine the grain size of twin roll cast AZ31 magnesium and potentially improve its superplastic properties. This work used isochronal and isothermal heat treatments to investigate the microstructural stability of twin roll cast, equal channel angular pressed and friction stir processed AZ31 magnesium. For both heat treatment conditions, it was found that the twin roll casted and equal channel angular pressed materials were more stable than the friction stir processed material. Calculations of the grain growth kinetics showed that severe plastic deformation processing decreased the activation energy for grain boundary motion with the equal channel angular pressed material having the greatest Q value of the severely plastically deformed materials and that increasing the tool travel speed of the friction stir processed material improved microstructural stability. The Hollomon-Jaffe parameter was found to be an accurate means of identifying the annealing conditions that will result in substantial grain growth and loss of potential superplastic properties in the severely plastically deformed materials. In addition, Humphreys’s model of cellular microstructural stability accurately predicted the relative microstructural stability of the severely plastically deformed materials and with some modification, closely predicted the maximum grain size ratio achieved by the severely plastically deformed materials.

Eficiencia en el sector financiero colombiano en el periodo 1995-2008

Directory of Open Access Journals (Sweden)

ALEJANDRO RAMÍREZ VIGOYA

2010-01-01

los años 1995 y 2008. La eficiencia se mide a través de los retornos de los factores de producción, en este caso de los préstamos y los salarios sobre los ingresos de los bancos. Como modelo teórico se utilizan funciones Cobb-Douglas y como modelo econométrico se utilizan datos panel. Se analizan los retornos en modelos de efectos fijos, ya que la muestra es toda la población de bancos comerciales en Colombia. Los modelos que se analizan se corren con efectos por año y con efectos por banco. Uno de los resultados interesantes es que el sector bancario en el periodo analizado presenta rendimientos constantes de escala. Se presenta menor eficiencia de todos los bancos en los años siguientes a la recesión de 1999.

En híbrida mezcolanza: Exile and Cultural Anxiety in Alirio Díaz Guerra’s Lucas Guevara

Directory of Open Access Journals (Sweden)

Jeffrey Browitt

2005-03-01

Full Text Available The novel Lucas Guevara, written by the Colombian exile, Alirio Díaz Guerra, was first published in New York in 1914. It is considered to be the earliest novel about Latin American immigration to the United States written in Spanish. This fact alone merits its study. A second edition was published in 2001 along with a critical-biographical introduction, which presents the novel as the precursor of a developing genre of Hispanic immigrant literature centred on the naïve Latin American migrant who arrives in the United States inspired by the opportunities which the metropolis supposedly affords, but who nevertheless suffers a series of misfortunes because of the inability to adapt to the new culture. On the level of overt content, the novel is a lachrymose, stereotypical and conventional denunciation of the supposed evils of an amoral US society and the libertine and materialistic values underpinning it. But on a much deeper level, a picture emerges of Díaz Guerra himself as a displaced, disenchanted intellectual exile who suffers (or has suffered an acute cultural and class anxiety in the transition from a patrician Arcadia to the heart of capitalist, industrial modernity. Through a reading of the narrative voice, and by extension the implied author, we witness his difficult coming to terms with a highly-charged New York society (in comparison to his homeland, not only because of the sexual liberation brought on by secular modernization, but also because of the close proximity of volatile, eroticised bodies on the over-crowded Lower East Side of New York, the scene of the novel and Díaz Guerra’s point of entry into the United States. The novel also provides an occasion to contrast how Díaz Guerra deals with the condition of exile, in contrast to that most emblematic of Latin American political refugees, José Martí.

Corrosion behavior of friction stir welded AZ31B Mg alloy - Al6063 alloy joint

Directory of Open Access Journals (Sweden)

B. Ratna Sunil

2016-12-01

Full Text Available In the present work, AZ31B Mg alloy and Al6063 alloy-rolled sheets were successfully joined by friction stir welding. Microstructural studies revealed a sound joint with good mechanical mixing of both the alloys at the nugget zone. Corrosion performance of the joint was assessed by immersing in 3.5% NaCl solution for different intervals of time and the corrosion rate was calculated. The joint has undergone severe corrosion attack compared with both the base materials (AZ31B and Al6063 alloys. The predominant corrosion mechanism behind the high corrosion rate of the joint was found to be high galvanic corrosion. From the results, it can be suggested that the severe corrosion of dissimilar Mg–Al joints must be considered as a valid input while designing structures intended to work in corroding environment.

Effect of antimony, bismuth and calcium addition on corrosion and electrochemical behaviour of AZ91 magnesium alloy

International Nuclear Information System (INIS)

Zhou Wei; Aung, Naing Naing; Sun Yangshan

2009-01-01

This study investigated the effect of antimony, bismuth and calcium addition on the corrosion and electrochemical behaviour of AZ91 magnesium alloy in 3.5% NaCl solution. Techniques including constant immersion, electrochemical potentiodynamic polarisation, scanning electron microscopy (SEM), energy dispersed spectroscopy (EDS) and X-ray diffraction (XRD) were used to characterise electrochemical and corrosion properties and surface topography. It was found that corrosion attack occurred preferentially on Mg 3 Bi 2 and Mg 3 Sb 2 particles while Mg 17 Al 8 Ca 0.5 and Mg 2 Ca phases showed no detrimental effect on corrosion. Combined addition of small amounts of bismuth and antimony to the AZ91 alloy resulted in significant increase in corrosion rate

Investigation on the Effect of Pulsed Energy on Strength of Fillet Lap Laser Welded AZ31B Magnesium Alloys

Science.gov (United States)

Salleh, M. N. M.; Ishak, M.; Aiman, M. H.; Idris, S. R. A.; Romlay, F. R. M.

2017-09-01

AZ31B magnesium alloy have been hugely applied in the aerospace, automotive, and electronic industries. However, welding thin sheet AZ31B was challenging due to its properties which is easily to evaporated especially using conventional fusion welding method such as metal inert gas (MIG). Laser could be applied to weld this metal since it produces lower heat input. The application of fiber laser welding has been widely since this type of laser could produce better welding product especially in the automotive sectors. Low power fiber laser was used to weld this non-ferrous metal where pulse wave (PW) mode was used. Double fillet lap joint was applied to weld as thin as 0.6 mm thick of AZ31B and the effect of pulsed energy on the strength was studied. Bond width, throat length, and penetration depth also was studied related to the pulsed energy which effecting the joint. Higher pulsed energy contributes to the higher fracture load with angle of irradiation lower than 3 °

Factorization of RSA-140 using the number field sieve

NARCIS (Netherlands)

S.H. Cavallar; B. Dodson; A.K. Lenstra (Arjen); P.C. Leyland; W.M. Lioen (Walter); P.L. Montgomery; B. Murphy; H.J.J. te Riele (Herman); P. Zimmermann

1999-01-01

textabstractOn February 2, 1999, we completed the factorization of the 140--digit number RSA--140 with the help of the Number Field Sieve factoring method (NFS). This is a new general factoring record. The previous record was established on April 10, 1996 by the factorization of the 130--digit

Hydroxyapatite coating on AZ91 magnesium alloy via sol-gel method

OpenAIRE

Albayrak, Sevda; Çinici, Hanifi; Çalın, Recep; Cömert, Canser

2018-01-01

Producinga material lighter than available biomaterials, having corrosion-resistance tobiological attacks and histocompatible similar to the bone structure in orderto use in biomedical applications is the purpose of this study. Lightness isextremely important in biomedical applications because stainless steel and manyof the similar heavy metallic alloys can lead to infection by causing harm totissues around the implant when it is used in the body. Although the lightnessof AZ91 Mg alloy is an ...

Constituyentes volátiles del mango de azúcar

OpenAIRE

Bautista., Edgar; Duque, Carmenza; Torres, Rafael

2010-01-01

Empleando Extracción de Volátiles por Espacio de Cabeza Dinámico y Extracción Líquido-Líquido, se estudió el aroma del mango de azúcar (Mangifera indica L), variedad nativa Colombiana apreciada por su exquisito aroma y sabor. Estos dos métodos complementarios permifieron la identificación, por Cromatografía de Gases de Alta resolución y Cromatografía de Gases de Alta Resolución - Espectrometría de Masas, de 52 coinponentes, entre los cuales sobresalieron como mayoritarios el 3-careno, el b...

Effects of filter materials on microstructure and mechanical properties of AZ91

Directory of Open Access Journals (Sweden)

Wu Guohua

2010-11-01

Full Text Available The present investigation studied the effects of different kinds of ceramic foam filters (CFF incorporating gas bubbling on the microstructure and mechanical properties of virgin AZ91 alloys, and the reactions between filters and Mg melt during filtration. The results show that the purification process of CFF incorporating gas bubbling process can obviously improve the Rm and A of AZ91 alloy, especially the A. Amongst the selected four kinds of CFF, the MgO filter is the most suitable for filtrating Mg melt, and the filtration effective sequence of four kinds of filtrating materials is as follows: MgO>Al2O3>ZrO2>SiC. With MgO filter incorporating gas bubbling treatment under Ar flow rate of 2 L/min and temperature of 730 °C, the ultimate tensile strength Rm and elongation A can be improved greatly from 175.3 MPa and 2.74% to 195.4 MPa and 4.54%, respectively. No inclusions are found on the fracture surface of the sample filtrated by MgO ceramic foam filter, and the fracture mode is quasi-cleavage crack.

Microstructure control during twin roll casting of an AZ31 magnesium alloy

International Nuclear Information System (INIS)

Huang, Y; Bayandorian, I; Fan, Z

2012-01-01

The existing twin roll casting technique for magnesium alloys suffers heterogeneity in both microstructure and chemistry and downstream processing is required to improve the strip quality, resulting in cost rise. In the present work, twin roll casting was carried out using an AZ31 magnesium alloy, with the application of intensive shearing melt conditioning prior to casting. The effect of process parameters such as pouring temperature and casting speed on microstructure control during casting and subsequent downstream processing was studied. Experimental results showed that the melt conditioning treatment allowed the production of AZ31 strips with uniform and refined microstructure free of centreline segregations. It was also shown that an optimized combination of pouring temperature and casting speed, in conjunction with a strip thickness control operation, resulted in uniformly distributed stored energies due to enhanced plastic deformation, which promoted recrystallization during casting and subsequent heat treatment. Strips prepared by twin roll casting and homogenization developed similar microstructural features to those prepared by twin roll casting followed by lengthy downstream processing by homogenization, hot rolling and annealing and displayed a weaker basal texture, exhibiting a potentially better formability.

Mechanical properties of AZ31 alloy processed by a green metallurgy route

International Nuclear Information System (INIS)

D'Enrico, F.; Garces, G.; Hofer, M.; Kim, S. K.; Perez, P.; Cabeza, S.; Adeva, P.

2013-01-01

Recently it has been proved that molding of defect-free components of various commercial alloys of magnesium can be carried out successfully when small amounts of CaO are added to the melt, making unnecessary the use of SF 6 coverage. In the case of AZ alloys, this process also remarkably improves their mechanical properties not only by the greater cleaning of alloys but also by the formation of CaAl 2 phase. This work, part of the Green project Metallurgy (http://www.green-metallurgy.eu) funded by the European Union (LIFE+2009), studies the influence of different CaO additions on the microstructure and mechanical properties of AZ31 Eco-Mg alloy. The alloy was processed by a conventional route involving extrusion of as-cast rods as well as by a powder metallurgy route (PM) using chips as starting material. The objective was to analyze the viability of recycling machining chips to manufacture components for the automobile industry and transportation in general, because of its low cost and environmental impact. It has been demonstrated that alloys processed from chips exhibit the highest tensile stress values, close to 320 MPa. (Author)

Desarrollo de las pequeñas industrias rurales de la caña de azúcar en iberoamerica: Melaza, Panela y Azúcar Moreno

OpenAIRE

Da Silva, Fabio César; Cesar, Marco; Hernández Díaz-Ambrona, Carlos Gregorio

2010-01-01

Los niveles de producción de azúcar en los últimos años crecen a un ritmo semejante al crecimiento poblacional. El fabricante debe estar atento a las características de calidad del producto que su mercado o comprador/consumidor exige y la facilidad de transporte al centro consumidor. La legislación debe especificar los requisitos mínimos pero el fabricante debe tener como desafío ofrecer un producto de calidad y reducir los riesgos ambientales en sus cultivos en función de la aptitud de la...

A New Factor in American Destiny: Visions of Porfirio Díaz and the Politics of “Logical Paternalism”

Directory of Open Access Journals (Sweden)

Jason Ruiz

2011-12-01

Full Text Available This essay interprets American representations of dictator Porfirio Díaz in relation to the “economic conquest” of Mexico that took place during his long rule (1876–1911, a period known as the “Porfiriato,” in which Americans invested more than $1 billion. No single person inspired as much attention from travelers, reporters, and photographers during the late nineteenth and early twentieth centuries as Díaz, and their visions of the President helped to shape perceptions of Mexico as a desirable field in which to expand US capitalism and influence. Travelers clamored to meet him and his sophisticated young wife, and their travelogues were rich with descriptions of such encounters. Reporters, dazzled by the rapid transformation of Mexico during his 35-year rule, described Díaz in such terms as “the Mexican Wizard” and “the maker of modern Mexico” until the very end of his regime. Photographers, working in a relatively new medium, amassed a huge body of works devoted to the dictator; even at an advanced age late in his rule, the President’s image adorned postcards and commemorative cartes-de-visite that posited him in heroic and hypermasculine terms (not unlike those of his US counterpart, Theodore Roosevelt. Ultimately, this essay argues that representations like these reflected American desires for a Mexican body politic that was amenable to economic and social transformation under the inextricable banners of “progress” and US capitalism. Prevailing images of Díaz and his family suggested that Mexico was as friendly to foreign investors as it was to foreign visitors.

Laser surface forming of AlCoCrCuFeNi particle reinforced AZ91D matrix composites

Science.gov (United States)

Meng, Guanghui; Yue, T. M.; Lin, Xin; Yang, Haiou; Xie, Hui; Ding, Xu

2015-07-01

Traditionally, the laser melt injection (LMI) technique can only be used for forming ceramic particles reinforced metal matrix composites (MMCs) for enhancing surface properties of lightweight engineering materials. In this research, the LMI method was employed to form metal particles reinforced MMCs on AZ91D instead. This was viable because of the unique properties of the AlCoCrCuFeNi high-entropy alloy (HEA) metal particles used. The large difference in melting point between the HEA and the substrate material (AZ91D), and the limited reaction and the lack of fusion between the HEA and Mg have made it possible that a metal particles reinforced AZ91D composite material was produced. The reason of limited reaction was considered mainly due to the relatively high mixing enthalpy between the HEA constituent elements and Mg. Although there was some melting occurred at the particles surface with some solute segregation found in the vicinity close to the surface, intermetallic compounds were not observed. With regard to the wear resistance of the MMCs, it was found that when the volume fraction of the reinforcement phase, i.e. the HEA particles, reached about 0.4, the wear volume loss of the coating was only one-seventh of that of the substrate material.

Corrosion behaviors in physiological solution of cerium conversion coatings on AZ31 magnesium alloy

International Nuclear Information System (INIS)

Cui Xiufang; Yang Yuyun; Liu Erbao; Jin Guo; Zhong Jinggao; Li Qingfen

2011-01-01

In this paper, a non-toxic Ce-based conversion coating was obtained on the surface of bio-medical AZ31 magnesium alloys. The micro-morphology of the coating prepared with optimal technical parameters and immersed in physiological solution (Hank's solution) in different time was observed by scanning electron microscopy (SEM), composition of the cerium conversion coating and corrosion products in Hank's solution were characterized by X-ray photoelectron spectroscopy (XPS) and energy dispersive spectroscopy (EDS), respectively. In addition, the corrosion property in Hank's solution was studied by electrochemical experiment and immersion test. The results show that the dense Ce-based conversion coating is obtained on the surface of AZ31 magnesium alloys in optimal technical parameters and the conversion coating consists of a mass of trivalent and tetravalent cerium oxides. The cerium conversion coating can provide obvious protection of magnesium alloys and can effectively reduce the degradation speed in Hank's solution. Also the degradation products have little influence on human body.

High speed cutting of AZ31 magnesium alloy

Directory of Open Access Journals (Sweden)

Liwei Lu

2016-06-01

Full Text Available Using LBR-370 numerical control lathe, high speed cutting was applied to AZ31 magnesium alloy. The influence of cutting parameters on microstructure, surface roughness and machining hardening were investigated by using the methods of single factor and orthogonal experiment. The results show that the cutting parameters have an important effect on microstructure, surface roughness and machine hardening. The depth of stress layer, roughness and hardening present a declining tendency with the increase of the cutting speed and also increase with the augment of the cutting depth and feed rate. Moreover, we established a prediction model of the roughness, which has an important guidance on actual machining process of magnesium alloy.

The surface chemistry of 3-mercaptopropyltrimethoxysilane films deposited on magnesium alloy AZ91

International Nuclear Information System (INIS)

Scott, A.; Gray-Munro, J.E.

2009-01-01

Magnesium and its alloys have desirable physical and mechanical properties for a number of applications. Unfortunately, these materials are highly susceptible to corrosion, particularly in the presence of aqueous solutions. The purpose of this study is to develop a uniform, non-toxic surface treatment to enhance the corrosion resistance of magnesium alloys. This paper reports the influence of the coating bath parameters and alloy microstructure on the deposition of 3-mercaptopropyltrimethoxysilane (MPTS) coatings on magnesium alloy AZ91. The surface chemistry at the magnesium/MPTS interface has also been explored. The results indicate that the deposition of MPTS onto AZ91 was influenced by both the pH and MPTS concentration in the coating bath. Furthermore, scanning electron microscopy results showed that the MPTS film deposited uniformly on all phases of the magnesium alloy surface. X-ray photoelectron spectroscopy studies revealed that at the magnesium/MPTS interface, the molecules bond to the surface through the thiol group in an acid-base interaction with the Mg(OH) 2 layer, whereas in the bulk of the film, the molecules are randomly oriented.

Microstructural characterization and finite element modeling of AZ31 magnesium alloys welded joints

Directory of Open Access Journals (Sweden)

José A. Segarra

2018-03-01

Full Text Available In this article, it has been studied how the microstructure of AZ31 magnesium alloy can be affected by the thermic cycles produced by welding processes, trying to modeling by element finite software the thermic cycles in this material. The AZ31 samples tested were welded using Gas Tugsten Arc Welding (GTAW and different filler materials. For this investigation, optic microscopy, scanning electronic microscopy, and finite elements method software has been used. This work indicates in one hand that in this type of alloys the microconstituyentes are Al-Mn o Al-Mn-Mg compounds, the presence of β-phase cannot be found at room temperature in this research at room, on the other hand the obtained simulation models indicate that the recrystallization takes place in the areas which reach maximum temperatures around 550 °C, this value is also the limit of the dissolution area for the Al-Mn o Al-Mn-Mg precipitated particles which are very likely to act as inhibitors of the corrosion in NaCl electrolytes.

32 CFR 935.140 - Motor vehicle maintenance and equipment.

Science.gov (United States)

2010-07-01

... 32 National Defense 6 2010-07-01 2010-07-01 false Motor vehicle maintenance and equipment. 935.140... AND INSULAR REGULATIONS WAKE ISLAND CODE Motor Vehicle Code § 935.140 Motor vehicle maintenance and equipment. (a) Each person who has custody of a motor vehicle on Wake Island shall present that vehicle for...

Analysis of metallic traces from the biodegradation of endomedullary AZ31 alloy temporary implants in rat organs after long implantation times.

Science.gov (United States)

Bodelón, O G; Iglesias, C; Garrido, J; Clemente, C; Garcia-Alonso, M C; Escudero, M L

2015-08-04

AZ31 alloy has been tested as a biodegradable material in the form of endomedullary implants in female Wistar rat femurs. In order to evaluate the accumulation of potentially toxic elements from the biodegradation of the implant, magnesium (Mg), aluminium (Al), zinc (Zn), manganese (Mn) and fluorine (F) levels have been measured in different organs such as kidneys, liver, lungs, spleen and brain. Several factors that may influence accumulation have been taken into account: how long the implant has been in place, whether or not the bone is fractured, and the presence of an MgF2 protective coating on the implant. The main conclusions and the clinical relevance of the study have been that AZ31 endomedullary implants have a degradation rate of about 60% after 13 months, which is fully compatible with fracture consolidation. Neither bone fracture nor an MgF2 coating seems to influence the accumulation of trace elements in the studied organs. Aluminium is the only alloying element in this study that requires special attention. The increase in Al recovered from the sampled organs represents 3.95% of the amount contained in the AZ31 implant. Al accumulates in a statistically significant way in all the organs except the brain. All of this suggests that in long-term tests AZ31 may be a suitable material for osteosynthesis.

78 FR 23135 - Safety Zone; Blue Water Resort & Casino West Coast Nationals; Parker, AZ

Science.gov (United States)

2013-04-18

...-AA00 Safety Zone; Blue Water Resort & Casino West Coast Nationals; Parker, AZ AGENCY: Coast Guard, DHS... Water Resort & Casino West Coast Nationals. This temporary safety zone is necessary to provide for the....). RPM Racing Enterprises is sponsoring the Blue Water Resort & Casino West Coast Nationals, which is...

75 FR 5115 - Temporary Concession Contract for Lake Mead National Recreation Area, AZ/NV

Science.gov (United States)

2010-02-01

... National Recreation Area, AZ/NV AGENCY: National Park Service, Department of the Interior. ACTION: Notice of intention to award temporary concession contract for Lake Mead National Recreation Area. SUMMARY: Pursuant to 36 CFR 51.24, public notice is hereby given that the National Park Service intends to award a...

Comparison of Electrochemical Methods for the Evaluation of Cast AZ91 Magnesium Alloy

Czech Academy of Sciences Publication Activity Database

Tkacz, J.; Minda, J.; Fintová, Stanislava; Wasserbauer, J.

2016-01-01

Roč. 9, č. 11 (2016), č. článku 925. ISSN 1996-1944 Institutional support: RVO:68081723 Keywords : AZ91 magnesium alloy * cathodic polarization curve * anodic polarization curve * linear polarization curve Subject RIV: JK - Corrosion ; Surface Treatment of Materials Impact factor: 2.654, year: 2016 http://www.mdpi.com/1996-1944/9/11/925

Autoantibodies to a 140-kd protein in juvenile dermatomyositis are associated with calcinosis.

LENUS (Irish Health Repository)

Gunawardena, H

2009-06-01

OBJECTIVE: The identification of novel autoantibodies in juvenile dermatomyositis (DM) may have etiologic and clinical implications. The aim of this study was to describe autoantibodies to a 140-kd protein in children recruited to the Juvenile DM National Registry and Repository for UK and Ireland. METHODS: Clinical data and sera were collected from children with juvenile myositis. Sera that recognized a 140-kd protein by immunoprecipitation were identified. The identity of the p140 autoantigen was investigated by immunoprecipitation\\/immunodepletion, using commercial monoclonal antibodies to NXP-2, reference anti-p140, and anti-p155\\/140, the other autoantibody recently described in juvenile DM. DNA samples from 100 Caucasian children with myositis were genotyped for HLA class II haplotype associations and compared with those from 864 randomly selected UK Caucasian control subjects. RESULTS: Sera from 37 (23%) of 162 patients with juvenile myositis were positive for anti-p140 autoantibodies, which were detected exclusively in patients with juvenile DM and not in patients with juvenile DM-overlap syndrome or control subjects. No anti-p140 antibody-positive patients were positive for other recognized autoantibodies. Immunodepletion suggested that the identity of p140 was consistent with NXP-2 (the previously identified MJ autoantigen). In children with anti-p140 antibodies, the association with calcinosis was significant compared with the rest of the cohort (corrected P < 0.005, odds ratio 7.0, 95% confidence interval 3.0-16.1). The clinical features of patients with anti-p140 autoantibodies were different from those of children with anti-p155\\/140 autoantibodies. The presence of HLA-DRB1*08 was a possible risk factor for anti-p140 autoantibody positivity. CONCLUSION: This study has established that anti-p140 autoantibodies represent a major autoantibody subset in juvenile DM. This specificity may identify a further immunogenetic and clinical phenotype within the

AZ-101 Mixer Pump Demonstration and Tests Data Management Analysis Plan

Energy Technology Data Exchange (ETDEWEB)

DOUGLAS, D.G.

2000-02-22

This document provides a plan for the analysis of the data collected during the AZ-101 Mixer Pump Demonstration and Tests. This document was prepared after a review of the AZ-101 Mixer Pump Test Plan (Revision 4) [1] and other materials. The plan emphasizes a structured and well-ordered approach towards handling and examining the data. This plan presumes that the data will be collected and organized into a unified body of data, well annotated and bearing the date and time of each record. The analysis of this data will follow a methodical series of steps that are focused on well-defined objectives. Section 2 of this plan describes how the data analysis will proceed from the real-time monitoring of some of the key sensor data to the final analysis of the three-dimensional distribution of suspended solids. This section also identifies the various sensors or sensor systems and associates them with the various functions they serve during the test program. Section 3 provides an overview of the objectives of the AZ-101 test program and describes the data that will be analyzed to support that test. The objectives are: (1) to demonstrate that the mixer pumps can be operated within the operating requirements; (2) to demonstrate that the mixer pumps can mobilize the sludge in sufficient quantities to provide feed to the private contractor facility, and (3) to determine if the in-tank instrumentation is sufficient to monitor sludge mobilization and mixer pump operation. Section 3 also describes the interim analysis that organizes the data during the test, so the analysis can be more readily accomplished. Section 4 describes the spatial orientation of the various sensors in the tank. This section is useful in visualizing the relationship of the Sensors in terms of their location in the tank and how the data from these sensors may be related to the data from other sensors. Section 5 provides a summary of the various analyses that will be performed on the data during the test

AZ-101 Mixer Pump Demonstration and Tests: Data Management (Analysis) Plan

International Nuclear Information System (INIS)

DOUGLAS, D.G.

2000-01-01

This document provides a plan for the analysis of the data collected during the AZ-101 Mixer Pump Demonstration and Tests. This document was prepared after a review of the AZ-101 Mixer Pump Test Plan (Revision 4) [1] and other materials. The plan emphasizes a structured and well-ordered approach towards handling and examining the data. This plan presumes that the data will be collected and organized into a unified body of data, well annotated and bearing the date and time of each record. The analysis of this data will follow a methodical series of steps that are focused on well-defined objectives. Section 2 of this plan describes how the data analysis will proceed from the real-time monitoring of some of the key sensor data to the final analysis of the three-dimensional distribution of suspended solids. This section also identifies the various sensors or sensor systems and associates them with the various functions they serve during the test program. Section 3 provides an overview of the objectives of the AZ-101 test program and describes the data that will be analyzed to support that test. The objectives are: (1) to demonstrate that the mixer pumps can be operated within the operating requirements; (2) to demonstrate that the mixer pumps can mobilize the sludge in sufficient quantities to provide feed to the private contractor facility, and (3) to determine if the in-tank instrumentation is sufficient to monitor sludge mobilization and mixer pump operation. Section 3 also describes the interim analysis that organizes the data during the test, so the analysis can be more readily accomplished. Section 4 describes the spatial orientation of the various sensors in the tank. This section is useful in visualizing the relationship of the Sensors in terms of their location in the tank and how the data from these sensors may be related to the data from other sensors. Section 5 provides a summary of the various analyses that will be performed on the data during the test

High power, 140 GHz gyrotron

International Nuclear Information System (INIS)

Kreischer, K.E.; Temkin, R.J.; Mulligan, W.J.; MacCabe, S.; Chaplya, R.

1982-01-01

The design and construction of a pulsed 100 kW, 140 GHz gyrotron is described. Initial gyrotron operation is expected in early 1982. Advances in gyrotron theory have also been carried out in support of this experimental research. The application of gyrotrons to plasma diagnostics is also under investigation. (author)

Effect of the Strain Rate on the Tensile Properties of the AZ31 Magnesium Alloy

International Nuclear Information System (INIS)

Jeong, Seunghun; Park, Jiyoun; Choi, Ildong; Park, Sung Hyuk

2013-01-01

The effect of the strain rate at a range of 10‒4 ⁓ 3 × 10"2s"-1 on the tensile characteristics of a rolled AZ31 magnesium alloy was studied. The normal tensile specimens were tested using a high rate hydraulic testing machine. Specimens were machined from four sheets with different thicknesses, 1, 1.5, 2 and 3 mm, along three directions, 0°, 45°, and 90° to the rolling direction. The results revealed that all the specimens had a positive strain rate sensitivity of strength, that is, the strength increased with increasing strain rate. This is the same tendency as other automotive steels have. Our results suggest that the AZ31 magnesium alloy has better collision characteristics at high strain rates because of improved strength with an increasing strain rate. Ductility decreased with an increasing strain rate with a strain rate under 1 s"-1, but it increased with an increasing strain rate over 1 s"-1. The mechanical properties of the AZ31 magnesium alloy depend on the different microstructures according to the thickness. Two and 3 mm thickness specimens with a coarse and non-uniform grain structure exhibited worse mechanical properties while the 1.5 mm thickness specimens with a fine and uniform grain structure had better mechanical properties. Specimens machined at 0° and 45° to the rolling direction had higher absorbed energy than that of the 90° specimen. Thus, we demonstrate it is necessary to choose materials with proper thickness and machining direction for use in automotive applications.

Iron Phosphate Glass for Vitrifying Hanford AZ102 LAW in Joule Heated and Cold Crucible Induction Melters - 12240

Energy Technology Data Exchange (ETDEWEB)

Day, Delbert E.; Brow, Richard K.; Ray, Chandra S.; Reis, Signo T. [Missouri University of Science and Technology, 1870 Miner Circle, Rolla, MO 65409 (United States); Kim, Cheol-Woon [MO-SCI Corporation, 4040 HyPoint North, Rolla, MO 65401 (United States); Vienna, John D.; Sevigny, Gary [Pacific North West National Laboratory, Battelle Blvd., Richland, WA 99352 (United States); Peeler, David; Johnson, Fabienne C.; Hansen, Eric K. [Savannah River National Laboratory, Savannah River Site, 999-W, Aiken, SC 29803 (United States); Soelberg, Nick [Idaho National Laboratory, 2525 Fremont Avenue, Idaho Falls, ID 83415 (United States); Pegg, Ian L.; Gan, Hao [Catholic University of America, 620 Michigan Avenue, N.E., Washington, DC 20064 (United States)

2012-07-01

An iron phosphate composition for vitrifying a high sulfate (∼17 wt%) and high alkali (∼80 wt%) Hanford low activity waste (LAW), known as AZ-102 LAW, has been developed for processing in a Joule Heated Melter (JHM) or a Cold Crucible Induction Melter (CCIM). This composition produced a glass waste form, designated as MS26AZ102F-2, with a waste loading of 26 wt% of the AZ-102 which corresponded to a total alkali and sulfate (represented as SO{sub 3}) content of 21 and 4.4 wt%, respectively. A slurry (7 M Na{sup +}) of MS26AZ102F-2 simulant was melted continuously at temperatures between 1030 and 1090 deg. C for 10 days in a small JHM at PNNL and for 70 hours in a CCIM at INL. The as-cast glasses produced in both melters and in trial laboratory experiments along with their canister centerline cooled (CCC) counterparts met the requirements for the Product Consistency Test (PCT) and the Vapor Hydration Test (VHT) responses in the Hanford Tank Waste Treatment and Immobilization Plant (WTP) Contract. These glass waste forms retained up to 77 % of the SO{sub 3} (3.3 wt%), 100% of the Cesium, and 33 to 44% of the rhenium (used as a surrogate for Tc) all of which either exceeded or were comparable to the retention limit for these species in borosilicate glass nuclear waste form. Analyses of commercial K-3 refractory lining and the Inconel 693 metal electrodes used in JHM indicated only minimum corrosion of these components by the iron phosphate glass. This is the first time that an iron phosphate composition was melted continuously in a slurry fed JHM and in the US, thereby, demonstrating that iron phosphate glasses can be used as alternative hosts for vitrifying nuclear waste. The following conclusions are drawn from the results of the present work. (1) An iron phosphate composition, designated as MS26AZ102F-2, containing 26 wt% of the simulated high sulfate (17 wt%), high alkali (80 wt%) Hanford AZ-102 LAW meets all the criteria for processing in a JHM and CCIM. This

40 CFR 80.140 - Definitions.

Science.gov (United States)

2010-07-01

... evaluated by weight. Leaded gasoline means gasoline which is produced with the use of any lead additive or... FUELS AND FUEL ADDITIVES Detergent Gasoline § 80.140 Definitions. The definitions in this section apply... given them in 40 CFR part 79, subpart A. Additization means the addition of detergent to gasoline or...

Corrosion behaviour of AZ91D and AM50 magnesium alloys with Nd and Gd additions in humid environments

Energy Technology Data Exchange (ETDEWEB)

Arrabal, R., E-mail: raularrabal@quim.ucm.es [Departamento de Ciencia de Materiales, Facultad de Ciencias Quimicas, Universidad Complutense, 28040 Madrid (Spain); Matykina, E.; Pardo, A.; Merino, M.C. [Departamento de Ciencia de Materiales, Facultad de Ciencias Quimicas, Universidad Complutense, 28040 Madrid (Spain); Paucar, K. [Gabinete de Corrosion, Facultad de Ingenieria Quimica y Textil, Universidad Nacional de Ingenieria, Cod. Postal 25, Lima (Peru); Mohedano, M.; Casajus, P. [Departamento de Ciencia de Materiales, Facultad de Ciencias Quimicas, Universidad Complutense, 28040 Madrid (Spain)

2012-02-15

Highlights: Black-Right-Pointing-Pointer Mg alloys with additions of Nd and Gd were exposed to high humidity atmosphere. Black-Right-Pointing-Pointer The increase of Nd or Gd diminished the effect of micro-galvanic couples. Black-Right-Pointing-Pointer Corrosion resistance of the AM50 alloy improved with the addition of Nd or Gd by 43%. Black-Right-Pointing-Pointer Nd and Gd had no significant effect on the corrosion resistance of the AZ91D alloy. - Abstract: AM50 and AZ91D alloys modified with rare earths (RE) were evaluated under atmospheric conditions. Nd and Gd additions resulted in formation of Al{sub 2}RE and Al-Mn-RE compounds and reduction of the fraction of {beta}-phase. According to surface potential maps, RE-containing intermetallics were more noble than the {beta}-phase, but less than Al-Mn inclusions. As a result, the action of micro-galvanic couples depended on the added amount of RE and the initial alloy microstructure. Nd or Gd additions improved the corrosion resistance of the AM50 alloy by up to 43%, but had no significant effect on the corrosion resistance of the AZ91D alloy.

Corrosion behaviour of AZ91D and AM50 magnesium alloys with Nd and Gd additions in humid environments

International Nuclear Information System (INIS)

Arrabal, R.; Matykina, E.; Pardo, A.; Merino, M.C.; Paucar, K.; Mohedano, M.; Casajús, P.

2012-01-01

Highlights: ► Mg alloys with additions of Nd and Gd were exposed to high humidity atmosphere. ► The increase of Nd or Gd diminished the effect of micro-galvanic couples. ► Corrosion resistance of the AM50 alloy improved with the addition of Nd or Gd by 43%. ► Nd and Gd had no significant effect on the corrosion resistance of the AZ91D alloy. - Abstract: AM50 and AZ91D alloys modified with rare earths (RE) were evaluated under atmospheric conditions. Nd and Gd additions resulted in formation of Al 2 RE and Al–Mn–RE compounds and reduction of the fraction of β-phase. According to surface potential maps, RE-containing intermetallics were more noble than the β-phase, but less than Al–Mn inclusions. As a result, the action of micro-galvanic couples depended on the added amount of RE and the initial alloy microstructure. Nd or Gd additions improved the corrosion resistance of the AM50 alloy by up to 43%, but had no significant effect on the corrosion resistance of the AZ91D alloy.

Factores de competitividad de la agroindustria de la caña de azúcar en México

Directory of Open Access Journals (Sweden)

Noé Aguilar Rivera

2011-01-01

Full Text Available La industria azucarera de México integra actividades agrícolas de crecimiento, cosecha y transporte de caña a la producción de azúcar estándar y refinada, con otros productos y subproductos. Para competir en una economía global, es importante establecer criterios de desempeño para reducir costos de producción en términos de competitividad técnica, productividad y eficiencia en aspectos como rendimientos, caña de azúcar y agroindustrial por hectárea y de fábrica. En este artículo se discuten algunos indicadores de competitividad económica y técnica de la industria de caña de azúcar mexicana, con metodologías de benchmarking y diamante de Porter. Los resultados mostraron que son numerosos los factores técnicos y económicos que limitan el crecimiento, debido a que la industria mexicana se ha mantenido no competitiva y requiere mejorar e innovar en la reducción de costos, sobre todo en materia prima, cosecha y transporte. También está la diversificación, con base en los subproductos, como residuos de cosecha, bagazo, melazas, lodo de filtros y vinazas; esto es de gran importancia como fuente renovable de energía y materias primas.

Influence of Route-R on wrought magnesium AZ61 alloy mechanical properties through equal channel angular pressing

Directory of Open Access Journals (Sweden)

Muralidhar Avvari

2014-06-01

Full Text Available A new fundamental route entitled ‘Route-R’ is introduced to refine the grains in the material through Equal Channel Angular Pressing (ECAP process. In route R, specimen is inverted to the original position in each ECAP pass. In the present work, AZ61 alloy is processed using ECAP process for three different fundamental routes mainly route A, route Bc, and route R. ECAP experiment is carried out on AZ61 alloy at lower temperature of 483 K up to two passes. Microstructural characterization is evaluated on unECAPed and ECAPed specimens for three routes. Average grain size of the alloy is to be reduced from 66 μm to 16 μm, 14.1 μm and 10 μm for route A routes Bc, and route R respectively. Vickers microhardness of the alloy is found to be 60 HV for as received material. This microhardness of the alloy is increased to 71 HV, 72 HV, and 74 HV for route A, route Bc, and route R respectively. Mechanical properties of the AZ61 alloy are observed to be route R is providing maximum YS, UTS, and percentage elongation than other route A and route Bc. Tensile fracture topography of the specimen is analyzed using three different routes for two passes.

Temporal regulation of foregut development by HTZ-1/H2A.Z and PHA-4/FoxA.

Directory of Open Access Journals (Sweden)

Dustin L Updike

2006-09-01

Full Text Available The histone variant H2A.Z is evolutionarily conserved and plays an essential role in mice, Drosophila, and Tetrahymena. The essential function of H2A.Z is unknown, with some studies suggesting a role in transcriptional repression and others in activation. Here we show that Caenorhabditis elegans HTZ-1/H2A.Z and the remodeling complex MYS-1/ESA1-SSL-1/SWR1 synergize with the FoxA transcription factor PHA-4 to coordinate temporal gene expression during foregut development. We observe dramatic genetic interactions between pha-4 and htz-1, mys-1, and ssl-1. A survey of transcription factors reveals that this interaction is specific, and thus pha-4 is acutely sensitive to reductions in these three proteins. Using a nuclear spot assay to visualize HTZ-1 in living embryos as organogenesis proceeds, we show that HTZ-1 is recruited to foregut promoters at the time of transcriptional onset, and this recruitment requires PHA-4. Loss of htz-1 by RNAi is lethal and leads to delayed expression of a subset of foregut genes. Thus, the effects of PHA-4 on temporal regulation can be explained in part by recruitment of HTZ-1 to target promoters. We suggest PHA-4 and HTZ-1 coordinate temporal gene expression by modulating the chromatin environment.

23 CFR 140.603 - Programs.

Science.gov (United States)

2010-04-01

... Bond Issue Projects § 140.603 Programs. Programs covering projects to be financed from the proceeds of bonds shall be prepared and submitted to FHWA. Project designations shall be the same as for regular Federal-aid projects except that the prefix letter “B” for bond issue shall be used as the first letter of...

77 FR 20356 - Foreign-Trade Zone 277-Western Maricopa County, AZ; Application for Manufacturing Authority...

Science.gov (United States)

2012-04-04

... Maricopa County, AZ; Application for Manufacturing Authority; Suntech Arizona, Inc., (Solar Panel... facility is used for the manufacture of 275 and 290 watt solar panels for industrial use. Components and... to solar panels (duty-free) for the foreign inputs noted above. Suntech would also be exempt from...

Microstructure and corrosion behavior of laser surface-treated AZ31B Mg bio-implant material.

Science.gov (United States)

Wu, Tso-Chang; Ho, Yee-Hsien; Joshi, Sameehan S; Rajamure, Ravi S; Dahotre, Narendra B

2017-05-01

Although magnesium and magnesium alloys are considered biocompatible and biodegradable, they suffer from poor corrosion performance in the human body environment. In light of this, surface modification via rapid surface melting of AZ31B Mg alloy using a continuous-wave Nd:YAG laser was conducted. Laser processing was performed with laser energy ranging from 1.06 to 3.18 J/mm 2 . The corrosion behavior in simulated body fluid of laser surface-treated and untreated AZ31B Mg alloy samples was evaluated using electrochemical technique. The effect of laser surface treatment on phase and microstructure evolution was evaluated using X-ray diffraction and scanning electron microscopy. Microstructure examination revealed grain refinement as well as formation and uniform distribution of Mg 17 Al 12 phase along the grain boundary for laser surface-treated samples. Evolution of such unique microstructure during laser surface treatment indicated enhancement in the corrosion resistance of laser surface-treated samples compared to untreated alloy.

Evaluation of self-healing ability of Ce–V conversion coating on AZ31 magnesium alloy

Directory of Open Access Journals (Sweden)

Xiao Jiang

2016-09-01

Full Text Available This study investigated the influence of cerium nitrate in vanadate solutions on the properties of Ce–V conversion coatings on AZ31 magnesium alloys, and evaluated the self-healing behavior of the Ce–V conversion coating for AZ31 magnesium alloy. The results showed that the additions of cerium nitrate prevented pentavalent vanadium from reducing to tetravalent vanadium in the coatings during conversion reaction process. Adding appropriate cerium nitrate to vanadate solution led to a thicker coating with a more compact CeVO4 layer. The corrosion behavior of the Ce–V conversion coating was investigated by the electrochemical tests and the scratch immersion test in 3.5 wt.% NaCl solution. The self-healing ability of the coating was confirmed from all tests. The surface analysis revealed that the self-healing effect of the Ce–V conversion coating was only provided by the release and migration of vanadium compounds.

SIN TIERRAS NI LETRAS... HISTORIA DE LA EDUCACION MAPUCHE EN EL PERIODO REDUCCIONAL (1880-1930)

OpenAIRE

CANO, DANIEL

2011-01-01

Este es un estudio que analiza históricamente la educación entregada a los mapuches durante los años reduccionales. Dicho periodo ha sido determinado por la historiografía nacional como el tiempo que transcurrió desde la entrega del primer título de merced en 1884 –un año tras el término de la ocupación de la Araucanía- hasta 1929, cuando se concedió el último de aquellos títulos. Nuestro objetivo principal fue conocer con certeza el número total de niños mapuches que asistieron a la escuela ...

Mechanical properties of plasma-sprayed layers of aluminium and aluminium alloy on AZ 91

Czech Academy of Sciences Publication Activity Database

Kubatík, Tomáš František; Ctibor, Pavel; Mušálek, Radek; Janata, Marek

2017-01-01

Roč. 51, č. 2 (2017), s. 323-327 ISSN 1580-2949 R&D Projects: GA ČR(CZ) GP14-31538P Institutional support: RVO:61389021 Keywords : plasma spraying of aluminium * adhesion of coating * wear * magnesium alloy AZ91 Subject RIV: JG - Metallurgy OBOR OECD: Materials engineering Impact factor: 0.436, year: 2016

TiO2 Deposition on AZ31 Magnesium Alloy Using Plasma Electrolytic Oxidation

Directory of Open Access Journals (Sweden)

Leon White

2013-01-01

Full Text Available Plasma electrolytic oxidation (PEO has been used in the past as a useful surface treatment technique to improve the anticorrosion properties of Mg alloys by forming protective layer. Coatings were prepared on AZ31 magnesium alloy in phosphate electrolyte with the addition of TiO2 nanoparticles using plasma electrolytic oxidation (PEO. This present work focuses on developing a TiO2 functional coating to create a novel electrophotocatalyst while observing the surface morphology, structure, composition, and corrosion resistance of the PEO coating. Microstructural characterization of the coating was investigated by X-ray diffraction (XRD and scanning electron microscopy (SEM followed by image analysis and energy dispersive spectroscopy (EDX. The corrosion resistance of the PEO treated samples was evaluated with electrochemical impedance spectroscopy (EIS and DC polarization tests in 3.5 wt.% NaCl. The XRD pattern shows that the components of the oxide film include Mg from the substrate as well as MgO and Mg2TiO4 due to the TiO2 nanoparticle addition. The results show that the PEO coating with TiO2 nanoparticles did improve the corrosion resistance when compared to the AZ31 substrate alloy.

Ultrasonic Examination of Double-Shell Tank 241-AZ-102 Examination Completed August 2003

International Nuclear Information System (INIS)

Pardini, Allan F.; Posakony, Gerald J.

2003-01-01

COGEMA Engineering Corporation (COGEMA), under a contract from CH2M Hill Hanford Group (CH2M Hill), has performed an ultrasonic nondestructive examination of selected portions of Double-Shell Tank 241-AZ-102. The purpose of this examination was to provide information that could be used to evaluate the integrity of the wall of the primary tank. The requirements for the ultrasonic examination of Tank 241-AZ-102 were to detect, characterize (identify, size, and locate), and record measurements made of any wall thinning, pitting, or cracks that might be present in the wall of the primary tank. Any measurements that exceed the requirements set forth in the Engineering Task Plat (ETP), RPP-11832 (Jensen 2002) and summarized on page 1 of this document, are reported to CH2M Hill and the Pacific Northwest National Laboratory (PNNL) for further evaluation. Under the contract with CH2M Hill, all data is to be recorded on disk and paper copies of all measurements are provided to PNNL for third-party evaluation. PNNL is responsible for preparing a report that describes the results of the COGEMA ultrasonic examinations

Room Temperature Shear Band Development in Highly Twinned Wrought Magnesium AZ31B Sheet

Science.gov (United States)

Scott, Jon; Miles, Michael; Fullwood, David; Adams, Brent; Khosravani, Ali; Mishra, Raja K.

2013-01-01

Failure mechanisms were studied in wrought AZ31B magnesium alloy after forming under different strain paths. Optical micrographs were used to observe the shear band formation and regions of high twin density in samples strained under uniaxial, biaxial, and plane strain conditions. Interrupted testing at 4 pct effective strain increments, until failure, was used to observe the evolution of the microstructure. The results showed that shear bands, with a high percentage of twinned grains, appeared early in the samples strained under biaxial or plane strain tension. These bands are similar to those seen in uniaxial tension specimens just prior to failure where the uniaxial tensile ductility was much greater than that observed for plane strain or biaxial tension conditions. A forming limit diagram for AZ31B, which was developed from the strain data, showed that plane strain and biaxial tension had very similar limit strains; this contrasts with materials like steel or aluminum alloys, which typically have greater ductility in biaxial tension compared to plane strain tension.

Improvement of high temperature fatigue lifetime in AZ91 magnesium alloy by heat treatment

International Nuclear Information System (INIS)

Mokhtarishirazabad, Mehdi; Azadi, Mohammad; Hossein Farrahi, Gholam; Winter, Gerhard; Eichlseder, Wilfred

2013-01-01

In the present paper, an improvement in high temperature fatigue properties of the AZ91 magnesium alloy with rare earth elements has been obtained by a typical heat treatment, denoted by T6. For this objective, out-of-phase thermo-mechanical fatigue, room temperature and high temperature low cycle fatigue tests are performed to compare lifetimes. Several rare earth elements are initially added to the AZ91 alloy during a gravity casting process in permanent molds. Also, the type of the heat treatment is examined. Results of specimens with only the solution (the T4 heat treatment) and the solution with the ageing process (the T6 heat treatment) are compared under isothermal fatigue loadings. Microstructural investigations are carried out, before and after fatigue experiments to demonstrate the heat treatment effect. Results showed that both low cycle fatigue and thermo-mechanical fatigue of the alloy at high temperatures increases tremendously after the T6 heat treatment. This behavior attributes to the variation of the ductility, which was a result of microstructural changes during the heat treatment and the varying temperature in fatigue tests

Improvement of high temperature fatigue lifetime in AZ91 magnesium alloy by heat treatment

Energy Technology Data Exchange (ETDEWEB)

Mokhtarishirazabad, Mehdi [School of Metallurgy and Materials Engineering, Iran University of Science and Technology, Tehran (Iran, Islamic Republic of); Azadi, Mohammad, E-mail: m_azadi@ip-co.com [Fatigue and Wear Workgroup, Irankhodro Powertrain Company (IPCO), Tehran (Iran, Islamic Republic of); Hossein Farrahi, Gholam [School of Mechanical Engineering, Sharif University of Technology, Tehran (Iran, Islamic Republic of); Winter, Gerhard; Eichlseder, Wilfred [Chair of Mechanical Engineering, University of Leoben, Leoben (Austria)

2013-12-20

In the present paper, an improvement in high temperature fatigue properties of the AZ91 magnesium alloy with rare earth elements has been obtained by a typical heat treatment, denoted by T6. For this objective, out-of-phase thermo-mechanical fatigue, room temperature and high temperature low cycle fatigue tests are performed to compare lifetimes. Several rare earth elements are initially added to the AZ91 alloy during a gravity casting process in permanent molds. Also, the type of the heat treatment is examined. Results of specimens with only the solution (the T4 heat treatment) and the solution with the ageing process (the T6 heat treatment) are compared under isothermal fatigue loadings. Microstructural investigations are carried out, before and after fatigue experiments to demonstrate the heat treatment effect. Results showed that both low cycle fatigue and thermo-mechanical fatigue of the alloy at high temperatures increases tremendously after the T6 heat treatment. This behavior attributes to the variation of the ductility, which was a result of microstructural changes during the heat treatment and the varying temperature in fatigue tests.

21 CFR 173.140 - Esterase-lipase derived from Mucor miehei.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Esterase-lipase derived from Mucor miehei. 173.140... HUMAN CONSUMPTION Enzyme Preparations and Microorganisms § 173.140 Esterase-lipase derived from Mucor miehei. Esterase-lipase enzyme, consisting of enzyme derived from Mucor miehei var. Cooney et Emerson by...

El legado psicológico de Rogelio Díaz-Guerrero

OpenAIRE

Reynaldo Alarcón

2010-01-01

O autor identifica quatro dimensões básicas na obra do psicólogo mexicano Rogelio Díaz-Guerrero (1918-2004): a) seu interesse pioneiro por construir uma psicología do mexicano se inicia com a publicação de Estudios de psicología del mexicano (1961) e culmina 42 anos depois com seu livro Bajo las garras de la cultura. Psicología del mexicano 2 (2003); b) a orientação culturalista de seu pensamento; c) sua adesão à psicologia transcultural, em reação ao etnocentrismo psicológico dominante em su...

Effect of the Strain Rate on the Tensile Properties of the AZ31 Magnesium Alloy

Energy Technology Data Exchange (ETDEWEB)

Jeong, Seunghun; Park, Jiyoun; Choi, Ildong [Korea Maritime University, Busan (Korea, Republic of); Park, Sung Hyuk [Korea Institute of Materials Science, Changwon (Korea, Republic of)

2013-10-15

The effect of the strain rate at a range of 10‒4 ⁓ 3 × 10{sup 2}s{sup -}1 on the tensile characteristics of a rolled AZ31 magnesium alloy was studied. The normal tensile specimens were tested using a high rate hydraulic testing machine. Specimens were machined from four sheets with different thicknesses, 1, 1.5, 2 and 3 mm, along three directions, 0°, 45°, and 90° to the rolling direction. The results revealed that all the specimens had a positive strain rate sensitivity of strength, that is, the strength increased with increasing strain rate. This is the same tendency as other automotive steels have. Our results suggest that the AZ31 magnesium alloy has better collision characteristics at high strain rates because of improved strength with an increasing strain rate. Ductility decreased with an increasing strain rate with a strain rate under 1 s{sup -}1, but it increased with an increasing strain rate over 1 s{sup -}1. The mechanical properties of the AZ31 magnesium alloy depend on the different microstructures according to the thickness. Two and 3 mm thickness specimens with a coarse and non-uniform grain structure exhibited worse mechanical properties while the 1.5 mm thickness specimens with a fine and uniform grain structure had better mechanical properties. Specimens machined at 0° and 45° to the rolling direction had higher absorbed energy than that of the 90° specimen. Thus, we demonstrate it is necessary to choose materials with proper thickness and machining direction for use in automotive applications.

Interfacial Reaction Characteristics and Mechanical Properties of Welding-brazing Bonding Between AZ31B Magnesium Alloy and PRO500 Ultra-high Strength Steel

Directory of Open Access Journals (Sweden)

CHEN Jian-hua

2017-11-01

Full Text Available Experiments were carried out with TIG welding-brazing of AZ31B magnesium alloy to PRO500 steel using TIG arc as heat source. The interfacial reaction characteristics and mechanical properties of the welding-brazing bonding were investigated. The results show that an effective bonding is achieved between AZ31B magnesium alloy and PRO500 steel by using TIG welding-brazing method. Some spontaneous oxidation reactions result in the formation of a transition zone containing AlFe3 phase with rich oxide. The micro-hardness value of the interfacial transition zone is between that of the AZ31B and the PRO500. Temper softening zone appears due to the welding thermal cycle nearby the bonding position in the interface. A higher heat input makes an increase of the brittle phases and leads to an obvious decrease of the bonding strength.

Pérdidas laborales ocasionadas por muertes prematuras en España: un análisis para el periodo 2005-2009

Directory of Open Access Journals (Sweden)

Luz María Peña Longobardo

2015-01-01

Full Text Available Fundamentos: El impacto económico que causan las enfermedades va mucho más allá del gasto sanitario, transmitiéndose a la sociedad a través de diferentes dimensiones. El principal objetivo de este estudio fue estimar la evolución de las pérdidas de productividad laboral causadas por muertes prematuras en España durante el periodo 2005-2009. Métodos: Se emplearon varias fuentes estadísticas (Registro de defunciones según la causa de muerte, Encuesta de Población Activa y Encuesta de Estructura Salarial para desarrollar un modelo de simulación basado en el enfoque de capital humano que permitió estimar las pérdidas laborales ocasionadas por muertes prematuras para el periodo analizado. Adicionalmente, se llevaron a cabo dos escenarios alternativos en los que se analizó la influencia de la evolución epidemiológica en los resultados obtenidos. Resultados: El modelo de simulación mostró una caída de las pérdidas laborales asociadas a muertes prematuras que fue desde 8.935 millones de euros en 2005 a 8.073 millones de euros en 2009. El análisis de las causas reducidas de muerte señaló que nueve causas de enfermedad (accidentes de tráfico, tumor maligno de tráquea, suicidios, infarto agudo de miocardio, SIDA, cirrosis, tumor de mama, enfermedades cerebrovasculares y cáncer de colon supusieron el 35,6% del total de Años Potenciales de Vida Laboral Perdidos y 36,6% del total de pérdida estimada. Las pérdidas estimadas representaron el 0,98%, 0,85% y 0,77% del Producto Interior Bruto de 2005, 2007 y 2009, respectivamente. Conclusiones: Las pérdidas laborales ocasionadas por muertes prematuras en España disminuyeron sustancialmente en el periodo analizado. Esta reducción se debió fundamentalmente a la favorable evolución epidemiológica de la mortalidad prematura.

24 CFR 964.140 - Resident training.

Science.gov (United States)

2010-04-01

... TENANT PARTICIPATION AND TENANT OPPORTUNITIES IN PUBLIC HOUSING Tenant Participation § 964.140 Resident... Resident Management Corporations and duly elected Resident Councils; (3) Public housing policies, programs... colleges, vocational schools; and (4) HUD and other Federal agencies and other local public, private and...

Reemplazo de grasa y azúcar en magdalenas. Efecto sobre las propiedades reológicas, térmicas, de textura y sensoriales

OpenAIRE

MARTÍNEZ CERVERA, SANDRA

2013-01-01

El presente trabajo de tesis se centra en el estudio de las propiedades reológicas, térmicas, de textura y sensoriales de magdalenas en las que se ha reemplazado parcial o totalmente la grasa o el azúcar. La masa de las magdalenas es una emulsión de aceite en agua compuesta por una base de harina que incorpora grasa y azúcar como ingredientes principales y, como opcionales, huevo, leche y otros componentes. El producto final se caracteriza por tener una estructura poro...

Feminism and Postmodernism in Paloma Díaz-Mas's "The World According to Valdés" and "In Search of a Portrait"

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Fuencisla Zomeño

2002-06-01

Full Text Available This paper analyzes the influence of postmodernism in Paloma Díaz-Mas's feminist approach through two short stories, "The World According to Valdés," and "In Search of a Portrait." The political situation after Franco's death embraced democracy which allowed writers to pay more attention to intellectual concerns. Women writers steered the radical positions of the 1970s toward a more philosophical and intellectual analysis of reality and artistic expression during the eighties. In these two short stories, Díaz-Mas addresses women's issues by questioning the scope of modernist and humanist views. She criticizes the modernist concept of unity (text/identity pointing out the discrimination that this unity creates in art, through the distinction between high art/mass culture; and in the individual, through the distinction between feminine/masculine and high/low. Even though Díaz-Mas's main characters in the two stories are women, she does not solely focus on defending them, but she contrasts present and past to parody the causes which produce discrimination in the social and artistic processes.

Standard Test Method for Measuring Reaction Rates by Analysis of Barium-140 From Fission Dosimeters

CERN Document Server

American Society for Testing and Materials. Philadelphia

2008-01-01

1.1 This test method describes two procedures for the measurement of reaction rates by determining the amount of the fission product 140Ba produced by the non-threshold reactions 235U(n,f), 241Am(n,f), and 239Pu(n,f), and by the threshold reactions 238U(n,f), 237Np(n,f), and 232Th(n,f). 1.2 These reactions produce many fission products, among which is 140Ba, having a half-life of 12.752 days. 140Ba emits gamma rays of several energies; however, these are not easily detected in the presence of other fission products. Competing activity from other fission products requires that a chemical separation be employed or that the 140Ba activity be determined indirectly by counting its daughter product 140La. This test method describes both procedure (a), the nondestructive determination of 140Ba by the direct counting of 140La several days after irradiation, and procedure (b), the chemical separation of 140Ba and the subsequent counting of 140Ba or its daughter 140La. 1.3 With suitable techniques, fission neutron fl...

Violencia contra la mujer en feminicidio en el periodo 2009- 2014 por regiones en el Perú

OpenAIRE

Torres Castillo, Rosa María

2017-01-01

La presente investigación “Violencia Contra la Mujer en Feminicidio en el periodo 2009 -2014 por regiones en el Perú” tuvo como objetivo general determinar las diferencias existentes en los casos de violencia contra la mujer en Feminicidio que se han producido en el quinquenio 2009-2014 por regiones en el Perú. La población estuvo conformada por las estadísticas de feminicidios de los años 2009-2014, la muestra censal considero toda la población, en los cuales se han emplead...

Determinantes y perfiles de la participacion laboral en Colombia en el periodo 2002-2013

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Nestor Ivan Gonzalez-Quintero

2015-06-01

Full Text Available Para establecer los determinantes de la participación laboral en Colombia, sobre una muestra de individuos con representatividad nacional, así como el aporte de cada uno de estos determinantes a la dinámica de la tasa de participación en el periodo 2002-2013, se estiman modelos tipo probit y se establecen perfiles de participación, a partir de las probabilidades estimadas, condicionadas para cuatro grupos de mujeres y hombres en diferentes rangos de edad. Se concluye que alcanzar niveles de educación superior, contar con un ingreso por pensión y la presencia de menores en el hogar son factores importantes para explicar tal dinámica.

A New Factor in American Destiny: Visions of Porfirio Díaz and the Politics of “Logical Paternalism”

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Jason Ruiz

2011-12-01

Full Text Available This essay interprets American representations of dictator Porfirio Díaz in relation to the “economic conquest” of Mexico that took place during his long rule (1876–1911, a period known as the “Porfiriato,” in which Americans invested more than $1 billion. No single person inspired as much attention from travelers, reporters, and photographers during the late nineteenth and early twentieth centuries as Díaz, and their visions of the President helped to shape perceptions of Mexico as a desirable field in which to expand US capitalism and influence. Travelers clamored to meet him and his sophisticated young wife, and their travelogues were rich with descriptions of such encounters. Reporters, dazzled by the rapid transformation of Mexico during his 35-year rule, described Díaz in such terms as “the Mexican Wizard” and “the maker of modern Mexico” until the very end of his regime. Photographers, working in a relatively new medium, amassed a huge body of works devoted to the dictator; even at an advanced age late in his rule, the President’s image adorned postcards and commemorative cartes-de-visite that posited him in heroic and hypermasculine terms (not unlike those of his US counterpart, Theodore Roosevelt. Ultimately, this essay argues that representations like these reflected American desires for a Mexican body politic that was amenable to economic and social transformation under the inextricable banners of “progress” and US capitalism. Prevailing images of Díaz and his family suggested that Mexico was as friendly to foreign investors as it was to foreign visitors.

Corrosion fatigue behaviors of two biomedical Mg alloys - AZ91D and WE43 - In simulated body fluid.

Science.gov (United States)

Gu, X N; Zhou, W R; Zheng, Y F; Cheng, Y; Wei, S C; Zhong, S P; Xi, T F; Chen, L J

2010-12-01

Magnesium alloys have been recently developed as biodegradable implant materials, yet there has been no study concerning their corrosion fatigue properties under cyclic loading. In this study the die-cast AZ91D (A for aluminum 9%, Z for zinc 1% and D for a fourth phase) and extruded WE43 (W for yttrium 4%, E for rare earth mischmetal 3%) alloys were chosen to evaluate their fatigue and corrosion fatigue behaviors in simulated body fluid (SBF). The die-cast AZ91D alloy indicated a fatigue limit of 50MPa at 10⁷ cycles in air compared to 20MPa at 10⁶ cycles tested in SBF at 37°C. A fatigue limit of 110MPa at 10⁷ cycles in air was observed for extruded WE43 alloy compared to 40MPa at 10⁷ cycles tested in SBF at 37°C. The fatigue cracks initiated from the micropores when tested in air and from corrosion pits when tested in SBF, respectively. The overload zone of the extruded WE43 alloy exhibited a ductile fracture mode with deep dimples, in comparison to a brittle fracture mode for the die-cast AZ91D. The corrosion rate of the two experimental alloys increased under cyclic loading compared to that in the static immersion test. Copyright © 2010 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Application of heat treatment and hot extrusion processes to improve mechanical properties of the AZ91 alloy

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T. Reguła

2010-04-01

Full Text Available The main aim of this paper is to evaluate the effects of hot working (extrusion and hest treatment on room temperature mechanical properties of magnesium-based AZ91 alloy. The results were compared with as-cast condition. The examined material had been obtained by gravity casting to permanent moulds and subsequently subjected to heat treatment and/or processed by extrusion at 648 K. Microstructural and mechanical properties of properly prepared specimens were studied. Rm, Rp02 and A5 were determined from tensile tests. Brinell hardness tests were also conducted. The research has shown that hot working of AZ91 alloy provides high mechanical properties unattainable by cast material subjected to heat-treatment. The investigated alloy subjected to hot working and subsequently heat-treated has doubled its strength and considerably improved the elongation - compared with the as-cast material.

Puccinia kuehnii (KRÜGER) BUTLER Y Puccinia melanocephala H. SYDOW Y P. SYDOW. EN EL CULTIVO DE LA CAÑA DE AZÚCAR

OpenAIRE

Infante, Danay; Martínez, B; González, E; González, Noyma

2009-01-01

La caña de azúcar es atacada por dos especies de Puccinia: la roya carmelita causada por P. melanocephala y la anaranjada por P. kuehnii. La primera ha prevalecido en el continente Americano, mientras que la segunda en Asia y Oceanía. Estas royas se diferencian respecto a las condiciones ambientales, la forma de presentarse el síntoma y el lugar de desarrollo del mismo. La mayor severidad causada por la roya carmelita se manifiesta durante los periodos fríos, en plantaciones de tres a seis me...

Aproximación a la evolución paleoecológica del periodo Tardiglaciar y Postglaciar del Pirineo Central (Ribagorza y Noguera).

OpenAIRE

Bergadà, M. M.; Fullola, J. M.; Serrat, D.; Montserrat Martí, Josep María; Vilaplana, J. M.

1992-01-01

[ES] Aproximación a la evolución paleoecológica durante el periodo Tardiglariar y postglaciar de dos puntos de Pirineo y la Depresión del Ebro mediante la correlación de depósitos de distin origen: Llauset (depósito lacustre) y Parco (depósito detrítico en cueva).

Bernal Díaz del Castillo, la memoria y la representación

Directory of Open Access Journals (Sweden)

María Luisa Fischer

2016-04-01

Full Text Available En este trabajo se analizan los procedimientos narrativos que verosimilizan la versión de la historia que define Bernal Díaz del Castillo. Se analiza la función que en el total del relato cumplen los capítulos de largos listados que lo cierran y, especialmente, el capítulo CCVI, dedicado a los retratos indistinguibles de los capitanes españoles de la Nueva España. Se muestra cómo la memoria privilegiada del cronista está funcionando bajo el predicamento de una retórica -en este caso, la del retrato del héroe, de origen medieval- que disputa su lugar frente a la pretendida reconstrucción de la experiencia por la vía única de la memoria. This work analyse the narrative procedures which Bernal Díaz del Castillo uses to make his version of history appear to be probable. The function of the long lists at the end of the story and, especially of Chapter CCVI, containing the indistinguishable portraits of New Spain's Spanish capitains is explained. How the chronicler's privileged memory functions as a rhetorical category -in this case, that of the portrait of a medieval hero- who argues his case for the pretended reconstruction of an experience based only on memory is shown.

El abordaje comparativo de 'La conquista' en dos autores mestizos: Garcilaso de la Vega y Ruiz Díaz Guzmán A comparative approach about 'La conquista' in the work of two mestizo authors: Garcilaso de la Vega y Ruiz Díaz Guzmán

Directory of Open Access Journals (Sweden)

Sebastián Eduardo Pardo

2011-12-01

Full Text Available El artículo propone analizar la representación del proceso de dominación colonial, coloquialmente conocido como "La Conquista", en los trabajos de dos autores pertenecientes a las primeras generaciones de mestizos de principios del siglo XVII: Garcilaso de la Vega y Ruy Díaz de Guzmán. La elección responde a dos cuestiones fundamentales; por un lado, ambos expresan un fuerte sentido de pertenencia regional al autodenominarse "naturales" de las áreas culturales sobre las cuales escriben; por la otra, ambos mantienen una relación compleja pero bien diferenciada con respecto a la problemática del mestizaje adscribiendo a identidades étnicas opuestas: mientras Garcilaso se presenta como inca, Ruy Díaz de Guzmán lo hace como español. En este sentido se discutirán las trayectorias de los mencionados autores para llevar a cabo el análisis comparado de sus vidas, sus ideologías y sus obras.This paper analyses the representation of colonial domination, process commonly known as "The Conquest", in the work of two writers belonging to the first half-breed generations of the early 17th century: Garcilaso de la Vega and Ruy Díaz de Guzmán. The selection is based on two fundamental criteria: on the one hand both declare themselves as "naturales" and reveal a strong sense of belonging regarding the cultural areas they describe; on the other hand, both attach themselves to opposite ethnic identities, thus maintaining a different relationship with the complex problems of mestizaje and miscegenation -while Garcilaso claims to be an Inca, Ruy Díaz de Guzmán introduces himself as a Spaniard. Therefore, the biographies of both authors are discussed in order to understand their life trajectories, ideologies and work from a comparative point of view.

Corrosion resistance of titanium ion implanted AZ91 magnesium alloy

International Nuclear Information System (INIS)

Liu Chenglong; Xin Yunchang; Tian Xiubo; Zhao, J.; Chu, Paul K.

2007-01-01

Degradable metal alloys constitute a new class of materials for load-bearing biomedical implants. Owing to their good mechanical properties and biocompatibility, magnesium alloys are promising in degradable prosthetic implants. The objective of this study is to improve the corrosion behavior of surgical AZ91 magnesium alloy by titanium ion implantation. The surface characteristics of the ion implanted layer in the magnesium alloys are examined. The authors' results disclose that an intermixed layer is produced and the surface oxidized films are mainly composed of titanium oxide with a lesser amount of magnesium oxide. X-ray photoelectron spectroscopy reveals that the oxide has three layers. The outer layer which is 10 nm thick is mainly composed of MgO and TiO 2 with some Mg(OH) 2 . The middle layer that is 50 nm thick comprises predominantly TiO 2 and MgO with minor contributions from MgAl 2 O 4 and TiO. The third layer from the surface is rich in metallic Mg, Ti, Al, and Ti 3 Al. The effects of Ti ion implantation on the corrosion resistance and electrochemical behavior of the magnesium alloys are investigated in simulated body fluids at 37±1 deg. C using electrochemical impedance spectroscopy and open circuit potential techniques. Compared to the unimplanted AZ91 alloy, titanium ion implantation significantly shifts the open circuit potential (OCP) to a more positive potential and improves the corrosion resistance at OCP. This phenomenon can be ascribed to the more compact surface oxide film, enhanced reoxidation on the implanted surface, as well as the increased β-Mg 12 Al 17 phase

Investigation of the chemical vicinity of defects in Mg and AZ31 with positron coincident Doppler boarding spectroscopy

International Nuclear Information System (INIS)

Stadlbauer, Martin

2008-01-01

Within the scope of the present work, two main goals have been achieved: Firstly, the coincident Doppler broadening spectrometer (CDBS) at the high intense positron source NEPOMUC has been elaborately improved in order to increase the spatial resolution for defect mapping measurements and to investigate samples with shallow positron trapping sites which are present e. g. in magnesium. Secondly, as an application, the chemical vicinity of defects in the industrially used magnesium based alloy AZ31 has been examined by means of the detailed investigation of ion-irradiated specimen with positron annihilation spectroscopy. Detailed simulations with the finite-element simulation tool COMSOL were used to optimize the focal diameter of the positron beam at the sample position in order to increase the spatial resolution. With a value of 0.3 mm, sub-mm resolution has now been reached. The CDBS has been furthermore equipped with a sample cooling unit in order to reach liquid nitrogen temperature, maintaining the feature of scanning the sample for defect mapping. Defects and their chemical surrounding in ion irradiated magnesium and the magnesium based alloy AZ31 were then investigated on an atomic scale with the CDBS. In the respective spectra the chemical information and the defect contribution have been thoroughly separated. For this purpose, samples of annealed Mg were irradiated with Mg-ions in order to create exclusively defects. In addition Al- and Zn-ion irradiations on Mg-samples were performed in order to create samples with both defects and impurity atoms. The ion irradiated area on the samples was investigated with laterally and depth resolved positron Doppler broadening spectroscopy (DBS) and compared with SRIM-simulations of the vacancy distribution. The investigation of the chemical vicinity of crystal defects in AZ31 was performed with CDBS on Mg-ion irradiated AZ31 with Mg-ion irradiated Mg. The outer tail of the energy distribution in the annihilation

Investigation of the chemical vicinity of defects in Mg and AZ31 with positron coincident Doppler boarding spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Stadlbauer, Martin

2008-03-10

Within the scope of the present work, two main goals have been achieved: Firstly, the coincident Doppler broadening spectrometer (CDBS) at the high intense positron source NEPOMUC has been elaborately improved in order to increase the spatial resolution for defect mapping measurements and to investigate samples with shallow positron trapping sites which are present e. g. in magnesium. Secondly, as an application, the chemical vicinity of defects in the industrially used magnesium based alloy AZ31 has been examined by means of the detailed investigation of ion-irradiated specimen with positron annihilation spectroscopy. Detailed simulations with the finite-element simulation tool COMSOL were used to optimize the focal diameter of the positron beam at the sample position in order to increase the spatial resolution. With a value of 0.3 mm, sub-mm resolution has now been reached. The CDBS has been furthermore equipped with a sample cooling unit in order to reach liquid nitrogen temperature, maintaining the feature of scanning the sample for defect mapping. Defects and their chemical surrounding in ion irradiated magnesium and the magnesium based alloy AZ31 were then investigated on an atomic scale with the CDBS. In the respective spectra the chemical information and the defect contribution have been thoroughly separated. For this purpose, samples of annealed Mg were irradiated with Mg-ions in order to create exclusively defects. In addition Al- and Zn-ion irradiations on Mg-samples were performed in order to create samples with both defects and impurity atoms. The ion irradiated area on the samples was investigated with laterally and depth resolved positron Doppler broadening spectroscopy (DBS) and compared with SRIM-simulations of the vacancy distribution. The investigation of the chemical vicinity of crystal defects in AZ31 was performed with CDBS on Mg-ion irradiated AZ31 with Mg-ion irradiated Mg. The outer tail of the energy distribution in the annihilation

Simulation of AZ-PN100 resist pattern fluctuation in X-ray lithography, including synchrotron beam polarization

International Nuclear Information System (INIS)

Scheckler, E.W.; Ogawa, Taro; Tanaka, Toshihiko; Takeda, Eiji; Oizumi, Hiroaki.

1993-01-01

A new simulation model for nanometer-scale pattern fluctuation in X-ray lithography is presented and applied to a study of AZ-PN100 negative chemical amplification resist. The exposure simulation considers polarized photons from a synchrotron radiation (SR) source. Monte Carlo simulation of Auger and photoelectron generation is followed by electron scattering simulation to determine the deposited energy distribution at the nanometer scale, including beam polarization effects. An acid-catalyst random walk model simulates the post-exposure bake (PEB) step. Fourier transform infrared (FTIR) spectroscopy and developed resist thickness measurements are used to fit PEB and rate models for AZ-PN100. A polymer removal model for development simulation predicts the macroscopic resist shape and pattern roughness. The simulated 3σ linewidth variation is in excess of 24 nm. Simulation also shows a detrimental effect if the beam polarization is perpendicular to the line. Simulation assuming a theoretical ideal exposure yields a 50 nm minimum line for standard process conditions. (author)

Optimization of process factors for self-healing vanadium-based conversion coating on AZ31 magnesium alloy

Energy Technology Data Exchange (ETDEWEB)

Li, Kun; Liu, Junyao [State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083 (China); Lei, Ting, E-mail: tlei@mail.csu.edu.cn [State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083 (China); Xiao, Tao [2nd Xiangya Hospital, Central South University, Changsha 410011 (China)

2015-10-30

Highlights: • The optimum operating conditions were determined by an orthogonal experiment. • The coating is composed of oxides and hydroxides of V{sup 5+}, V{sup 4+} and Mg(OH){sub 2}. • The self-healing performance was investigated by cross-cut immersion test. • The vanadia conversion coating provided active corrosion protection to AZ31 alloy. - Abstract: A self-healing vanadium-based conversion coating was prepared on AZ31 magnesium alloy. The optimum operating conditions including vanadia solution concentration, pH and treating temperature for obtaining the best corrosion protective vanadia coatings and improved localized corrosion resistance to the magnesium substrate were determined by an orthogonal experiment design. Surface morphology and composition of the resultant conversion coatings were investigated by scanning electron microscope (SEM) and X-ray photoelectron spectroscopy (XPS). The self-healing behavior of the coating was investigated by cross-cut immersion test and electrochemical impedance spectroscopy (EIS) measurements in 3.5% NaCl solution.

Optimization of process factors for self-healing vanadium-based conversion coating on AZ31 magnesium alloy

International Nuclear Information System (INIS)

Li, Kun; Liu, Junyao; Lei, Ting; Xiao, Tao

2015-01-01

Highlights: • The optimum operating conditions were determined by an orthogonal experiment. • The coating is composed of oxides and hydroxides of V"5"+, V"4"+ and Mg(OH)_2. • The self-healing performance was investigated by cross-cut immersion test. • The vanadia conversion coating provided active corrosion protection to AZ31 alloy. - Abstract: A self-healing vanadium-based conversion coating was prepared on AZ31 magnesium alloy. The optimum operating conditions including vanadia solution concentration, pH and treating temperature for obtaining the best corrosion protective vanadia coatings and improved localized corrosion resistance to the magnesium substrate were determined by an orthogonal experiment design. Surface morphology and composition of the resultant conversion coatings were investigated by scanning electron microscope (SEM) and X-ray photoelectron spectroscopy (XPS). The self-healing behavior of the coating was investigated by cross-cut immersion test and electrochemical impedance spectroscopy (EIS) measurements in 3.5% NaCl solution.

Influence of Friction Stir Welding on Mechanical Properties of Butt Joints of AZ61 Magnesium Alloy

Directory of Open Access Journals (Sweden)

Seung-Ju Sun

2017-01-01

Full Text Available In this study, the effect of heat input on the mechanical properties and fracture behaviors of AZ61 magnesium alloy joints has been studied. Magnesium alloy AZ61 plates with thickness of 5 mm were welded at different ratios of tool rotational speed to welding speed (ω/ν. The average ultimate tensile strength of all weld conditions satisfying a ω/ν ratio of 3 reached 100% of the strength of the base material. Fractures occurred at the interface between the thermomechanical affected zone at advancing side and the stir zone in all welded specimens. From the scanning electron microscope and electron backscatter diffraction analysis, it was determined that the interface between the thermomechanical affected zone and the stir zone, which is the region where the grain orientation changes, was the weakest part; the advancing side region was relatively weaker than the retreating side region because the grain orientation change occurred more dramatically in the advancing side region.

17 CFR 201.140 - Commission orders and decisions: Signature and availability.

Science.gov (United States)

2010-04-01

... 17 Commodity and Securities Exchanges 2 2010-04-01 2010-04-01 false Commission orders and decisions: Signature and availability. 201.140 Section 201.140 Commodity and Securities Exchanges SECURITIES... and decisions: Signature and availability. (a) Signature required. All orders and decisions of the...

Propiedades mecánicas de la aleación AZ31 procesada por una ruta eco-sostenible

Directory of Open Access Journals (Sweden)

D’Errico, F.

2013-12-01

Full Text Available Recently it has been proved that molding of defect-free components of various commercial alloys of magnesium can be carried out succesfully when small amounts of CaO are added to the melt, making unnecessary the use of SF6 coverage. In the case of AZ alloys, this process also remarkably improves their mechanical properties not only by the greater cleaning of alloys but also by the formation of CaAl2 phase. This work, part of the Green project Metallurgy (http://www.green-metallurgy.eu funded by the European Union (LIFE+2009, studies the influence of different CaO additions on the microstructure and mechanical properties of AZ31 Eco-Mg alloy. The alloy was processed by a conventional route involving extrusion of as-cast rods as well as by a powder metallurgy route (PM using chips as starting material. The objective was to analyze the viability of recycling machining chips to manufacture components for the automobile industry and transportation in general, because of its low cost and environmental impact. It has been demostrated that alloys processed from chips exhibit the highest tensile stress values, close to 320 MPa.Recientemente se ha demostrado la posibilidad de fabricar por moldeo, componentes libres de defectos de diferentes aleaciones comerciales de magnesio, añadiendo CaO al caldo, sin emplear SF6. En el caso de las aleaciones AZ este proceso, además, mejora notablemente las propiedades mecánicas, no sólo por la mayor limpieza de las aleaciones sino también por la presencia de la fase CaAl2 que se forma por la incorporación de calcio al caldo. Este trabajo, enmarcado dentro del proyecto Green Metallurgy (http://www.green-metallurgy.eu financiado por la Unión Europea (Programa LIFE+2009, estudia la influencia de diferentes adiciones de CaO en la microestructura y propiedades mecánicas de la aleación Eco-Mg AZ31. El estudio se lleva a cabo en aleaciones AZ31 con 0,5, 1 y 1,5% CaO procesadas por dos rutas diferentes, aleaciones

Organic coatings silane-based for AZ91D magnesium alloy

International Nuclear Information System (INIS)

Hu Junying; Li Qing; Zhong Xiankang; Li Longqin; Zhang Liang

2010-01-01

Organic coatings silane-based containing electron withdrawing group or electron donating group have been synthesized and evaluated as prospective surface treatments for AZ91D magnesium alloy by hydrolysis and condensation reaction of the different silanes. Electrochemical tests were employed to confirm the corrosion resistance ability of the two kinds of organic coatings. The results showed that the coating with electron donating group had better corrosion protection performance. On the basis of the spatial configuration and the density of charge of those silanes molecules which was obtained through Gaussian 03 procedure based on B3LYP and density functional theory, combining experiment results, the rational explanation was provided.

Near-liquidus forging, partial remelting and thixoforging of an AZ91D + Y magnesium alloy

International Nuclear Information System (INIS)

Zhao Zude; Chen Qiang; Hu Chuankai; Huang Shuhai; Wang Yuanqing

2009-01-01

A new route, near-liquidus forging plus partial remelting, has been developed for obtaining globular microstructures. Firstly, a material is formed by near-liquidus forging for obtaining a fine dendritic microstructure. Globular microstructure can be produced by reheating the material into the semi-solid temperature range for a period of time. In this paper, an AZ91D alloy with the addition of yttrium was prepared by near-liquidus forging. Microstructure evolution during partial remelting was studied at temperatures and for times. Tensile mechanical properties of thixoforged components were also determined. It is shown that the fine dendritic structure firstly evolves into a blocky structure during partial remelting. With prolonged holding time, the blocky structure disintegrates into polygonal solid particles. Prolonging time and increasing temperature promote a faster spheroidization. Good mechanical properties are obtained for the thixoforged AZ91D alloy with the addition of yttrium prepared by near-liquidus forging, with a yield strength of 160.9 MPa and a ultimate tensile strength of 301.7 MPa and a elongation to fracture of 9.734%.

Research on the drawing process with a large total deformation wires of AZ31 alloy

International Nuclear Information System (INIS)

Bajor, T; Muskalski, Z; Suliga, M

2010-01-01

Magnesium and their alloys have been extensively studied in recent years, not only because of their potential applications as light-weight engineering materials, but also owing to their biodegradability. Due to their hexagonal close-packed crystallographic structure, cold plastic processing of magnesium alloys is difficult. The preliminary researches carried out by the authors have indicated that the application of the KOBO method, based on the effect of cyclic strain path change, for the deformation of magnesium alloys, provides the possibility of obtaining a fine-grained structure material to be used for further cold plastic processing with large total deformation. The main purpose of this work is to present research findings concerning a detailed analysis of mechanical properties and changes occurring in the structure of AZ31 alloy wire during the multistage cold drawing process. The appropriate selection of drawing parameters and the application of multistep heat treatment operations enable the deformation of the AZ31 alloy in the cold drawing process with a total draft of about 90%.

Mechanical properties and microstructural evaluation of AA1100 to AZ31 dissimilar friction stir welds

Energy Technology Data Exchange (ETDEWEB)

Azizieh, M., E-mail: azizieh@gmail.com [Department of Materials Science and Engineering, Ahvaz Branch, Islamic Azad University, Ahvaz (Iran, Islamic Republic of); Sadeghi Alavijeh, A. [School of Mechatronic Systems Engineering, Simon Fraser University, 250-13450 102 Avenue, Surrey, BC V3T 0A3 (Canada); Abbasi, M. [High Temperature Energy Materials, Korea Institute of Science and Technology, Seoul, 136-791 (Korea, Republic of); Balak, Z. [Department of Materials Science and Engineering, Ahvaz Branch, Islamic Azad University, Ahvaz (Iran, Islamic Republic of); Kim, H.S. [Department of Materials Science and Engineering, Pohang University of Science and Technology, Pohang, 790-784 (Korea, Republic of)

2016-02-15

In this paper, microstructure and mechanical properties of dissimilar friction stir welds of AA1100 and AZ31 were investigated to understand the effects of rotational and travel speed as well as pin position. The tensile results of welded samples revealed that the sound welds were formed when the stirring pin deviated from the centreline to the AZ31 side. The X-ray diffraction shows that Al{sub 3}Mg{sub 2} and Al{sub 12}Mg{sub 17} intermetallics formation occurs in the stir zone during the welding process. High hardness of these intermetallic phases increased the hardness of the stir zone to 110 Hv. The best tensile results were obtained in the sample processed in the range of 28–32 (rev/mm) rotational to travel speed ratio. - Highlights: • For Al to Mg friction stir welding, tool offset must be to Mg side. • There is an optimum rotational speed for obtain the highest strength. • Intermetallics form in any welding condition. • The volume fraction of intermetallic is directly related to FSW peak temperature.

Novel hybrid sol-gel coatings for corrosion protection of AZ31B magnesium alloy

International Nuclear Information System (INIS)

Lamaka, S.V.; Montemor, M.F.; Galio, A.F.; Zheludkevich, M.L.; Trindade, C.; Dick, L.F.; Ferreira, M.G.S.

2008-01-01

This work aims to develop and study new anticorrosion films for AZ31B magnesium alloy based on the sol-gel coating approach. Hybrid organic-inorganic sols were synthesized by copolymerization of epoxy-siloxane and titanium or zirconium alkoxides. Tris(trimethylsilyl) phosphate was also used as additive to confer additional corrosion protection to magnesium-based alloy. A sol-gel coating, about 5-μm thick, shows good adhesion to the metal substrate and prevents corrosion attack in 0.005 M NaCl solution for 2 weeks. The sol-gel coating system doped with tris(trimethylsilyl)-phosphate revealed improved corrosion protection of the magnesium alloy due to formation of hydrolytically stable Mg-O-P chemical bonds. The structure and the thickness of the sol-gel film were characterized by transmission electron microscopy (TEM) and scanning electron microscopy (SEM). The corrosion behaviour of AZ31B substrates pre-treated with the sol-gel derived hybrid coatings was tested by electrochemical impedance spectroscopy (EIS). The chemical composition of the silylphosphate-containing sol-gel film at different depths was investigated by X-ray photoelectron spectroscopy (XPS) with depth profiling

Análisis del servicio de asistencia técnica ejecutado por la unidad municipal de asistencia técnica agropecuaria -Umata-, (periodo 1.998-2.007) en el municipio de Florencia, Caquetá

OpenAIRE

Lugo Perea, Leyson Jimmy

2009-01-01

En este estudio de analiza el servicio de asistencia agropecuaria que ha venido prestando la UMATA, durante el periodo 1998-2007 en Florencia Caquetá. Este ente descentralizado funciona básicamente a través de la ejecución de planes, programas y proyectos urbanos y rurales. Se identificaron y analizaron los planes, programas y proyectos desarrollados durante el periodo de estudio| la inversión y fuentes de financiación y se conocieron la percepción, valoración el...

Porfirio Díaz y la “Gran Dieta Simbólica”: ¿La masonería mexicana bajo control?

Directory of Open Access Journals (Sweden)

Rogelio Aragón

2015-01-01

Full Text Available Las fuentes más consultadas para la historia de la masonería en México durante el período conocido como"Porfiriato" apuntan a que fue, precisamente, el presidente Porfirio Díaz el artífice de la unificación de lamasonería bajo la llamada "Gran Dieta Simbólica". Sin embargo, el intercambio epistolar entre el generalDíaz y Ermilio Cantón -que más bien fue monólogo epistolar de este último-, dirigente de facto de la GranDieta, apunta en una dirección distinta. El presente artículo contrapone la información proporcionada por lasfuentes bibliográficas con la correspondencia del presidente.

The research on the effect of MgCO{sub 3} on the grain refinement in AZ31 magnesium alloy

Energy Technology Data Exchange (ETDEWEB)

Gao, S.Y.; Cui, J.Z.; Li, Q.C.; Zhang, Z.Q. [Key Laboratory of Electromagnetic Processing of Materials, Ministry of Education, Northeastern University, Shenyang (China)

2010-08-15

The effect of MgCO{sub 3} addition on the as-cast microstructure of AZ31 magnesium alloy has been widely investigated. The results show that the average grain size of the {alpha}-Mg grain in AZ31 magnesium alloy decreases from about 570 {mu}m to 100 {mu}m by the addition of 0.6 wt.% MgCO{sub 3} as gain refiner at 760 C. Based on the analysis of EDS, theoretical calculation of E{sub bind} and Gibbs free energy, we esteem that grain refiner mechanism is mainly attributed to the generation of Al{sub 4}C{sub 3}, which can be serviced as nucleation site and restrain grain boundary from growing and transferring. (Abstract Copyright [2010], Wiley Periodicals, Inc.)

In vitro and in vivo studies of biodegradable fine grained AZ31 magnesium alloy produced by equal channel angular pressing.

Science.gov (United States)

Ratna Sunil, B; Sampath Kumar, T S; Chakkingal, Uday; Nandakumar, V; Doble, Mukesh; Devi Prasad, V; Raghunath, M

2016-02-01

The objective of the present work is to investigate the role of different grain sizes produced by equal channel angular pressing (ECAP) on the degradation behavior of magnesium alloy using in vitro and in vivo studies. Commercially available AZ31 magnesium alloy was selected and processed by ECAP at 300°C for up to four passes using route Bc. Grain refinement from a starting size of 46μm to a grain size distribution of 1-5μm was successfully achieved after the 4th pass. Wettability of ECAPed samples assessed by contact angle measurements was found to increase due to the fine grain structure. In vitro degradation and bioactivity of the samples studied by immersing in super saturated simulated body fluid (SBF 5×) showed rapid mineralization within 24h due to the increased wettability in fine grained AZ31 Mg alloy. Corrosion behavior of the samples assessed by weight loss and electrochemical tests conducted in SBF 5× clearly showed the prominent role of enhanced mineral deposition on ECAPed AZ31 Mg in controlling the abnormal degradation. Cytotoxicity studies by MTT colorimetric assay showed that all the samples are viable. Additionally, cell adhesion was excellent for ECAPed samples particularly for the 3rd and 4th pass samples. In vivo experiments conducted using New Zealand White rabbits clearly showed lower degradation rate for ECAPed sample compared with annealed AZ31 Mg alloy and all the samples showed biocompatibility and no health abnormalities were noticed in the animals after 60days of in vivo studies. These results suggest that the grain size plays an important role in degradation management of magnesium alloys and ECAP technique can be adopted to achieve fine grain structures for developing degradable magnesium alloys for biomedical applications. Copyright © 2015 Elsevier B.V. All rights reserved.

Reação da laranjeira azêda à tristeza Reaction of the sour orange plant to tristeza

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A. S. Costa

1954-01-01

Full Text Available Mudinhas novas de laranjeira azêda podem ser infetadas com o vírus da tristeza por meio do afídio vetor da moléstia ou mais fàcilmente por enxertia. Plantas adultas são muitos resistentes, quase imunes. A recuperação do vírus da tristeza de plantas de laranja azeda infetadas é efetuada com facilidade por meio de enxertia e com muita dificuldade por meio do vetor. Os sintomas comumente apresentados por mudinhas de laranja azêda afetadas, consistem em amarelecimento das fôlhas novas, paralisação no crescimento e eventual queda das fôlhas amareladas. Em caso de infecção com estirpes fracas do vírus, os sintomas são menos evidentes e comumente há recuperação. As fôlhas formadas após recuperação, muitas vêzes apresentam palidez de pequenas extensões das nervuras. Os tecidos do floema da laranjeira azêda, abaixo do enxêrto de laranjeira doce infetada, mostram degeneração. Êstes sintomas têm sido utilizados para distinguir a tristeza de outras moléstias que causam declínio da planta. Sintomas de depressões no lenho ("pitting" raramente se manifestam em laranjeira azêda. Não se conhece presentemente nenhuma variedade de laranja azêda tolerante à tristeza, não se podendo, portanto, utilizar êsse cavalo para copas nas quais o vírus da tristeza se multiplica e atinge concentrações elevadas. Entretanto, a laranjeira azeda ainda pode ser usada como cavalo para alguns limões dos tipos Eureka e Siciliano e para a própria laranjeira azêda, em áreas invadidas pela moléstia. Há possibilidade de que o cavalo de azêda possa vir a ser novamente empregado para variedades que usualmente perecem quando nela enxertadas, lançando-se mão de medidas auxiliares como a inoculação prévia da copa com uma estirpe fraca do vírus, pela utilização do tipo de copa com união múltipla, etc. Borbulhas de plantas de laranja azêda afetadas pela tristeza nem sempre encerram o vírus. Borbulhas de plantas afetadas ou de

75 FR 11554 - Notice of Intent to Repatriate Cultural Items: Museum of Northern Arizona, Flagstaff, AZ

Science.gov (United States)

2010-03-11

... continue to be used by traditional Navajo religious practitioners. Based on the sacred esoteric knowledge... Northern Arizona, Flagstaff, AZ, that meet the definitions of ``sacred objects'' and ``objects of cultural... the area of Farmington, NM. The 29 cultural items are 4 watercolors of sacred Navajo Yei figures and...

Determination of the magnetic moment of $^{140}$Pr

CERN Multimedia

Kowalska, M; Kreim, K D; Krieger, A R; Litvinov, Y

We propose to measure the nuclear magnetic moment of the neutron-deficient isotope $^{140}$Pr using collinear laser spectroscopy at the COLLAPS experiment. This nuclide is one of two nuclear systems for which a modulated electron capture decay has been observed in hydrogen-like ions in a storage ring. The firm explanation of the observed phenomenon is still missing but some hypotheses suggest an interaction of the unpaired electron with the surrounding magnetic fields of the ring. In order to verify or discard these hypotheses the magnetic moment of $^{140}$Pr is required since this determines the energy of the 1s hyperfine splitting.

commodity: el caso del mercado internacional del azúcar

Directory of Open Access Journals (Sweden)

Julio César Alonso

2013-01-01

Full Text Available Este trabajo estudia el comportamiento estacional de los precios internacionales del azúcar transados en Nueva York y Londres. Para este caso, empleando pruebas de raíces estacionales y una muestra mensual desde enero de 1989 hasta diciembre de 2010, se encuentra la existencia de un comportamiento estacional estocástico no estacionario. Dicha conducta implica que un “verano” se puede convertir en un “invierno”, resultado que no había sido documentado previamente en estos mercados. Por otro lado, empleando dicho hallazgo, los resultados muestran que es posible construir un modelo autorregresivo de media móvil que se comporta relativamente mejor al pronosticar el precio frente a un modelo que no tiene en cuenta dicho tipo de estacionalidad.

A study on relations between the levels of GMP-140 and microangiopathy in NIDDM

International Nuclear Information System (INIS)

Du Tongxin; Wang Zizheng; Shi Hongzhen

1995-01-01

The relations between the level of GMP-140 and microangiopathy in NIDDM for earlier diagnosis or better treatment are investigated, the level of GMP-140 in both platelet and plasma was measured. The level of GMP-140 in both platelet and plasma in 104 cases with NIDDM (55 with and 49 without microagiopathy) and 38 controls were assayed by RIA and also simultaneously with direct platelet count. The level of GMP-140 in both platelet and plasma in NIDDM was remarkably higher than that in controls (P 1 = 0.69, r 2 = 0.75). No differences existed in platelet count between NIDDM and controls. The level of GMP-140 and ophthalmoscopic study had no change after decreasing the concentration of blood glucose (<7.8 mmol/L) and administrating aspirin for 6 months. Microangiopathy in NIDDM had close relation with platelet function and the level of GMP-140

Corrosion mechanism and model of pulsed DC microarc oxidation treated AZ31 alloy in simulated body fluid

Energy Technology Data Exchange (ETDEWEB)

Gu Yanhong, E-mail: ygu2@alaska.edu [Department of Mechanical Engineering, University of Alaska Fairbanks, Fairbanks, AK 99775 (United States); Chen Chengfu [Department of Mechanical Engineering, University of Alaska Fairbanks, Fairbanks, AK 99775 (United States); Bandopadhyay, Sukumar [Department of Mining Engineering, University of Alaska Fairbanks, Fairbanks, AK 99775 (United States); Ning Chengyun [College of Materials Science and Engineering, South China University of Technology, Guangzhou 510640 (China); Zhang Yongjun [Department of Mining Engineering, University of Alaska Fairbanks, Fairbanks, AK 99775 (United States); Guo Yuanjun [College of Materials Science and Engineering, South China University of Technology, Guangzhou 510640 (China)

2012-06-01

This paper addresses the effect of pulse frequency on the corrosion behavior of microarc oxidation (MAO) coatings on AZ31 Mg alloys in simulated body fluid (SBF). The MAO coatings were deposited by a pulsed DC mode at four different pulse frequencies of 300 Hz, 500 Hz, 1000 Hz and 3000 Hz with a constant pulse ratio. Potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) tests were used for corrosion rate and electrochemical impedance evaluation. The corroded surfaces were examined by X-ray diffraction (XRD), X-ray fluorescence (XRF) and optical microscopy. All the results exhibited that the corrosion resistance of MAO coating produced at 3000 Hz is superior among the four frequencies used. The XRD spectra showed that the corrosion products contain hydroxyapatite, brucite and quintinite. A model for corrosion mechanism and corrosion process of the MAO coating on AZ31 Mg alloy in the SBF is proposed.

Corrosion mechanism and model of pulsed DC microarc oxidation treated AZ31 alloy in simulated body fluid

International Nuclear Information System (INIS)

Gu Yanhong; Chen Chengfu; Bandopadhyay, Sukumar; Ning Chengyun; Zhang Yongjun; Guo Yuanjun

2012-01-01

This paper addresses the effect of pulse frequency on the corrosion behavior of microarc oxidation (MAO) coatings on AZ31 Mg alloys in simulated body fluid (SBF). The MAO coatings were deposited by a pulsed DC mode at four different pulse frequencies of 300 Hz, 500 Hz, 1000 Hz and 3000 Hz with a constant pulse ratio. Potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) tests were used for corrosion rate and electrochemical impedance evaluation. The corroded surfaces were examined by X-ray diffraction (XRD), X-ray fluorescence (XRF) and optical microscopy. All the results exhibited that the corrosion resistance of MAO coating produced at 3000 Hz is superior among the four frequencies used. The XRD spectra showed that the corrosion products contain hydroxyapatite, brucite and quintinite. A model for corrosion mechanism and corrosion process of the MAO coating on AZ31 Mg alloy in the SBF is proposed.

PML nuclear body component Sp140 is a novel autoantigen in primary biliary cirrhosis.

Science.gov (United States)

Granito, Alessandro; Yang, Wei-Hong; Muratori, Luigi; Lim, Mark J; Nakajima, Ayako; Ferri, Silvia; Pappas, Georgios; Quarneti, Chiara; Bianchi, Francesco B; Bloch, Donald B; Muratori, Paolo

2010-01-01

Some patients with primary biliary cirrhosis (PBC) have antinuclear antibodies (ANAs). These ANAs include the "multiple nuclear dots" (MND) staining pattern, targeting promyelocytic leukemia protein (PML) nuclear body (NB) components, such as "speckled 100-kD" protein (Sp100) and PML. A new PML NB protein, designated as Sp140, was identified using serum from a PBC patient. The aim of this study was to analyze the immune response against Sp140 protein in PBC patients. We studied 135 PBC patients and 157 pathological controls with type 1 autoimmune hepatitis, primary sclerosing cholangitis, and systemic lupus erythematosus. We used indirect immunofluorescence and a neuroblastoma cell line expressing Sp140 for detecting anti-Sp140 antibodies, and a commercially available immunoblot for detecting anti-Sp100 and anti-PML antibodies. Anti-Sp140 antibodies were present in 20 (15%) PBC patients but not in control samples, with a higher frequency in antimitochondrial antibody (AMA)-negative cases (53 vs. 9%, P<0.0001). Anti-Sp140 antibodies were found together with anti-Sp100 antibodies in all but one case (19 of 20, 90%) and with anti-PML antibodies in 12 (60%) cases. Anti-Sp140 positivity was not associated with a specific clinical feature of PBC. Our study identifies Sp140 as a new, highly specific autoantigen in PBC for the first time. The very frequent coexistence of anti-Sp140, anti-Sp100 and anti-PML antibodies suggests that the NB is a multiantigenic complex in PBC and enhances the diagnostic significance of these reactivities, which are particularly useful in AMA-negative cases.