Late presentation of posterior urethral valve: two case reports

Directory of Open Access Journals (Sweden)

Carlos Márcio Nóbrega de Jesus

Full Text Available CONTEXT: Posterior urethral valve (PUV is a widely known condition affecting males that generally presents prenatally or at birth. PUVs have also been occasionally described in literature in cases diagnosed during adolescence or adulthood. CASE REPORT: This report presents two late PUV cases, one in a teenager and the other in an adult. Both cases had had clinical signs of urinary tract infection and obstructive urinary symptoms. The diagnoses were made by means of voiding cystourethrography and urethrocystoscopy. Endoscopic valve fulguration was the treatment chosen for both. Their follow-up was uneventful.

Abnormal antenatal sonogram: an indicator of disease severity in children with posterior urethral valves

International Nuclear Information System (INIS)

Harvie, S.; McLeod, L.; Acott, P.; Walsh, E.; Abdolell, M.; Macken, M.B.

2009-01-01

To review the association of an abnormal prenatal sonogram with most recent serum creatinine in patients with proven posterior urethral valves (PUV). Since 1992, all live-born patients between 1992-2004 with clinically proven PUV, with postnatally proven PUV, from 2 pediatric tertiary care centers, were reviewed for age at diagnosis, most recent serum creatinine, presence of chronic renal failure (CRF) (serum creatinine >2 standard deviations above normal for age), or end stage renal disease (dialysis or transplant). Available antenatal reports from the 2 centres and surrounding community hospitals were reviewed for gestational age (GA) at the time of ultrasound, volume of amniotic fluid, and urinary-tract abnormality. Thirty-four patients with proven PUV and prenatal sonograms were identified (1992-2004). Eighteen patients had abnormalities on their prenatal sonogram, with poor outcome in 5 (mean follow-up, 8 years [1-13 y]). No specific features were identified on prenatal sonogram. Sixteen patients had normal prenatal sonograms, with poor outcomes in 2 (mean follow-up, 8 years [3-13 y]). There is an increased risk of an abnormal serum creatinine among those patients with an abnormal prenatal study, odds ratio (OR) 2.6 (95% confidence interval, 0.35-32). PUV represents a spectrum of disease severity. A normal prenatal ultrasound does not preclude PUV. The majority of patients with a normal prenatal examination have good outcomes. The OR suggests that there may be increased risk for poor outcome in those with an abnormal prenatal examination. A multicenter study is necessary to obtain a larger sample size and more precise ORs. (author)

Abnormal antenatal sonogram: an indicator of disease severity in children with posterior urethral valves

Energy Technology Data Exchange (ETDEWEB)

Harvie, S. [Peterborough Health Centre, Dept. of Radiology, Peterborough, Ontario (Canada); McLeod, L. [IWK Health Centre, Dept. of Obstetrics and Gynaecology, Halifax, Nova Scotia (Canada); Acott, P. [IWK Health Centre, Dept. of Nephrology, Halifax, Nova Scotia (Canada); Walsh, E. [Dr. Charles A. Janeway Children' s Health Centre, Dept. of Radiology, St. John' s, Newfoundland (Canada); Abdolell, M. [QE II Health Sciences Centre, Dept. of Radiology, Halifax, Nova Scotia (Canada); Macken, M.B., E-mail: mmacken@dal.ca [IWK Health Centre, Dept. of Diagnostic Imaging, Halifax, Nova Scotia (Canada)

2009-10-15

To review the association of an abnormal prenatal sonogram with most recent serum creatinine in patients with proven posterior urethral valves (PUV). Since 1992, all live-born patients between 1992-2004 with clinically proven PUV, with postnatally proven PUV, from 2 pediatric tertiary care centers, were reviewed for age at diagnosis, most recent serum creatinine, presence of chronic renal failure (CRF) (serum creatinine >2 standard deviations above normal for age), or end stage renal disease (dialysis or transplant). Available antenatal reports from the 2 centres and surrounding community hospitals were reviewed for gestational age (GA) at the time of ultrasound, volume of amniotic fluid, and urinary-tract abnormality. Thirty-four patients with proven PUV and prenatal sonograms were identified (1992-2004). Eighteen patients had abnormalities on their prenatal sonogram, with poor outcome in 5 (mean follow-up, 8 years [1-13 y]). No specific features were identified on prenatal sonogram. Sixteen patients had normal prenatal sonograms, with poor outcomes in 2 (mean follow-up, 8 years [3-13 y]). There is an increased risk of an abnormal serum creatinine among those patients with an abnormal prenatal study, odds ratio (OR) 2.6 (95% confidence interval, 0.35-32). PUV represents a spectrum of disease severity. A normal prenatal ultrasound does not preclude PUV. The majority of patients with a normal prenatal examination have good outcomes. The OR suggests that there may be increased risk for poor outcome in those with an abnormal prenatal examination. A multicenter study is necessary to obtain a larger sample size and more precise ORs. (author)

Solid-phase extraction of plutonium in various oxidation states from simulated groundwater using N-benzoylphenylhydroxylamine

International Nuclear Information System (INIS)

Perevalov, S.A.; Malofeeva, G.I.; Kuzovkina, E.V.; Spivakov, B.Ya.

2013-01-01

Solid-phase extraction of plutonium in different individual and mixed oxidation states from simulated groundwater (pH 8.5) was studied. The extraction of plutonium species was carried out in a dynamic mode using DIAPAK C16 cartridges modified by N-benzoylphenylhydroxylamine (BPHA). It was shown that the extent of recovery depends on the oxidation state of plutonium. The extraction of Pu(IV) was at the level of 98-99% regardless of the volume and flow-rate of the sample solution. Pu(V) was extracted by 90-95% and 75-80% from 10- and 100-mL aliquots of the samples, respectively, whereas the extraction of Pu(VI) did not exceed 45-50%. An equimolar mixture of Pu(IV), Pu(V), and Pu(VI) was extracted by 74%. The distribution coefficients (K d ) and kinetic exchange capacities (S) of plutonium in various oxidation states were measured. It was found that during the sorption process, Pu(V) was reduced to Pu(IV) by 80-90% after an hour-long contact with the solid phase. Pu(VI) is reduced to Pu(V) by 34% and to Pu(IV) by 55%. In the case of mixed-valent solution of plutonium, only Pu(V) and Pu(IV) were found in the effluents. (author)

Posterior urethral valves: Risk factors for progression to renal failure.

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Bilgutay, Aylin N; Roth, David R; Gonzales, Edmond T; Janzen, Nicolette; Zhang, Wei; Koh, Chester J; Gargollo, Patricio; Seth, Abhishek

2016-06-01

Posterior urethral valves (PUVs) are the most common etiology for congenital urethral obstruction and congenital bilateral renal obstruction. PUVs produce a spectrum of urologic and renal sequelae. Our aims were to assess outcomes of PUV patients, to determine whether vesicoureteral reflux (VUR) is a risk factor for progression to renal failure, and to identify other risk factors for poor outcomes. We conducted a retrospective analysis of PUV patients from 2006 to 2014. Data collected included demographics, initial renal ultrasound (RUS) findings, creatinine at presentation and nadir, pre- and postoperative VUR status, presence or absence of recurrent urinary tract infections (UTIs), and surgical intervention(s). Univariate and multivariate analyses were used to determine risk factors for renal failure. Of 104 patients, 42.3% (44/104) were diagnosed prenatally, 31.8% (14/44) of whom underwent prenatal intervention. Postnatally, 90.4% (94/104) initially underwent transurethral resection of PUVs (TUR-PUVs). Vesicostomy was the next most common index surgery (4.8%). Forty-two percent (44/104) required >1 surgery. The predominant second surgery was repeat TUR-PUV in 16 patients. At last follow-up (mean 28.8 months after initial surgery), 20.2% had chronic kidney disease (CKD) of at least stage IIIA, and 8.6% had progressed to end-stage renal disease (ESRD). Antenatal diagnosis, prematurity, abnormal renal cortex, and loss of corticomedullary differentiation (CMD) on initial RUS were associated with CKD and ESRD on univariate analysis, as were elevated creatinine on presentation and at nadir. Presence of pre- or postoperative VUR and recurrent UTIs were associated with the need for multiple surgeries, but not with poor renal outcomes. On multivariate analysis, nadir creatinine was the only independent predictor of final renal function. Our finding that creatinine is the only independent risk factor for poor renal outcomes in PUV patients is consistent with the

Predictive value of CT for first esophageal variceal bleeding in patients with cirrhosis: Value of para-umbilical vein patency

Energy Technology Data Exchange (ETDEWEB)

Calame, Paul [Department of Radiology, University Hospitals of Besançon (France); Ronot, Maxime, E-mail: maxime.ronot@aphp.fr [Paris Nord Val de Seine, Beaujon, Clichy, Hauts-de-Seine (France); University Paris Diderot, Sorbonne Paris Cité, Paris (France); INSERM U1149, centre de recherche biomédicale Bichat-Beaujon, CRB3, Paris (France); Bouveresse, Sébastien [Department of Radiology, University Hospitals of Besançon (France); Cervoni, Jean-Paul [Department of Hepatology, University Hospitals of Besançon (France); Vilgrain, Valérie [Paris Nord Val de Seine, Beaujon, Clichy, Hauts-de-Seine (France); University Paris Diderot, Sorbonne Paris Cité, Paris (France); INSERM U1149, centre de recherche biomédicale Bichat-Beaujon, CRB3, Paris (France); Delabrousse, Éric [Department of Radiology, University Hospitals of Besançon (France)

2017-02-15

Highlights: • Large PUV are more frequent in patients without variceal bleeding and in those low-risk esophageal varices. • The PUV diameter is smaller in patients who experience variceal bleeding. • The imaging score could help to identify cirrhotic patients at high-risk for EVH. • Cirrhotic patients with high imaging score should be referred for treatment. - Abstract: Purpose: To evaluate if the presence/size of a para-umbilical vein (PUV) on computed tomography (CT) are associated with a first esophageal variceal hemorrhage (EVH) in patients with cirrhosis and whether imaging features can help identify patients at increased risk of EVH. Materials and methods: From January 2010 to June 2012 patients with cirrhosis who underwent CT and upper gastrointestinal endoscopy within six months were included. The presence/size of PUV was noted. PUV >5 mm were considered large (LPUV). Association with a first EVH was searched for, and validated in a prospective cohort of 55 patients. Results: 172 patients (113 men, mean 60 ± 12 yo) were included. Forty-three patients (25%) experienced a first EVH. LPUV were more frequent in the group without EVH (27% vs. 7%, p = 0.005). At multivariate analysis, factors associated with a first EVH were spleen size > 135 mm (Odd Ratio [OR] = 1.32 [95% confident interval [CI] 1.16–1.51], p < 0.001), ascites (OR = 4.07 [95%CI-1.84–9.01], p = 0.001) and small/absent PUV (OR = 3.06 [95%CI-1.86–5.05], p < 0.001). An imaging score combining these factors was significantly associated with first EVH in the study and the validation cohorts (EVH in 0%, 19%, and 33% when score 0–1, 2–3, and 4–5, respectively). Conclusions: A simple imaging score combining the PUV and spleen size, and the presence of ascites could help to identify cirrhotic patients at high-risk for EVH.

Predictive value of CT for first esophageal variceal bleeding in patients with cirrhosis: Value of para-umbilical vein patency

International Nuclear Information System (INIS)

Calame, Paul; Ronot, Maxime; Bouveresse, Sébastien; Cervoni, Jean-Paul; Vilgrain, Valérie; Delabrousse, Éric

2017-01-01

Highlights: • Large PUV are more frequent in patients without variceal bleeding and in those low-risk esophageal varices. • The PUV diameter is smaller in patients who experience variceal bleeding. • The imaging score could help to identify cirrhotic patients at high-risk for EVH. • Cirrhotic patients with high imaging score should be referred for treatment. - Abstract: Purpose: To evaluate if the presence/size of a para-umbilical vein (PUV) on computed tomography (CT) are associated with a first esophageal variceal hemorrhage (EVH) in patients with cirrhosis and whether imaging features can help identify patients at increased risk of EVH. Materials and methods: From January 2010 to June 2012 patients with cirrhosis who underwent CT and upper gastrointestinal endoscopy within six months were included. The presence/size of PUV was noted. PUV >5 mm were considered large (LPUV). Association with a first EVH was searched for, and validated in a prospective cohort of 55 patients. Results: 172 patients (113 men, mean 60 ± 12 yo) were included. Forty-three patients (25%) experienced a first EVH. LPUV were more frequent in the group without EVH (27% vs. 7%, p = 0.005). At multivariate analysis, factors associated with a first EVH were spleen size > 135 mm (Odd Ratio [OR] = 1.32 [95% confident interval [CI] 1.16–1.51], p < 0.001), ascites (OR = 4.07 [95%CI-1.84–9.01], p = 0.001) and small/absent PUV (OR = 3.06 [95%CI-1.86–5.05], p < 0.001). An imaging score combining these factors was significantly associated with first EVH in the study and the validation cohorts (EVH in 0%, 19%, and 33% when score 0–1, 2–3, and 4–5, respectively). Conclusions: A simple imaging score combining the PUV and spleen size, and the presence of ascites could help to identify cirrhotic patients at high-risk for EVH.

A Systematic Review on Renal and Bladder Dysfunction after Endoscopic Treatment of Infravesical Obstruction in Boys

NARCIS (Netherlands)

Hennus, Pauline M. L.; van der Heijden, Geert J. M. G.; Bosch, J. L. H. Ruud; de Jong, Tom P. V. M.; de Kort, Laetitia M. O.

2012-01-01

Background: Posterior urethral valves (PUV) may cause subtle to severe obstruction of the urethra, resulting in a broad clinical spectrum. PUV are the most common cause of chronic renal disease in boys. Our purpose was to report the incidences of kidney and bladder dysfunction in boys treated with

Semantically supporting data discovery, markup and aggregation in the European Marine Observation and Data Network (EMODnet)

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Lowry, Roy; Leadbetter, Adam

2014-05-01

The semantic content of the NERC Vocabulary Server (NVS) has been developed over thirty years. It has been used to mark up metadata and data in a wide range of international projects, including the European Commission (EC) Framework Programme 7 projects SeaDataNet and The Open Service Network for Marine Environmental Data (NETMAR). Within the United States, the National Science Foundation projects Rolling Deck to Repository and Biological & Chemical Data Management Office (BCO-DMO) use concepts from NVS for markup. Further, typed relationships between NVS concepts and terms served by the Marine Metadata Interoperability Ontology Registry and Repository. The vast majority of the concepts publicly served from NVS (35% of ~82,000) form the British Oceanographic Data Centre (BODC) Parameter Usage Vocabulary (PUV). The PUV is instantiated on the NVS as a SKOS concept collection. These terms are used to describe the individual channels in data and metadata served by, for example, BODC, SeaDataNet and BCO-DMO. The PUV terms are designed to be very precise and may contain a high level of detail. Some users have reported that the PUV is difficult to navigate due to its size and complexity (a problem CSIRO have begun to address by deploying a SISSVoc interface to the NVS), and it has been difficult to aggregate data as multiple PUV terms can - with full validity - be used to describe the same data channels. Better approaches to data aggregation are required as a use case for the PUV from the EC European Marine Observation and Data Network (EMODnet) Chemistry project. One solution, proposed and demonstrated during the course of the NETMAR project, is to build new SKOS concept collections which formalise the desired aggregations for given applications, and uses typed relationships to state which PUV concepts contribute to a specific aggregation. Development of these new collections requires input from a group of experts in the application domain who can decide which PUV

Developing data aggregation applications from a community standard semantic resource (Invited)

Science.gov (United States)

Leadbetter, A.; Lowry, R. K.

2013-12-01

The semantic content of the NERC Vocabulary Server (NVS) has been developed over thirty years. It has been used to mark up metadata and data in a wide range of international projects, including the European Commission (EC) Framework Programme 7 projects SeaDataNet and The Open Service Network for Marine Environmental Data (NETMAR). Within the United States, the National Science Foundation projects Rolling Deck to Repository and Biological & Chemical Data Management Office (BCO-DMO) use concepts from NVS for markup. Further, typed relationships between NVS concepts and terms served by the Marine Metadata Interoperability Ontology Registry and Repository. The vast majority of the concepts publicly served from NVS (35% of ~82,000) form the British Oceanographic Data Centre (BODC) Parameter Usage Vocabulary (PUV). The PUV is instantiated on the NVS as a SKOS concept collection. These terms are used to describe the individual channels in data and metadata served by, for example, BODC, SeaDataNet and BCO-DMO. The PUV terms are designed to be very precise and may contain a high level of detail. Some users have reported that the PUV is difficult to navigate due to its size and complexity (a problem CSIRO have begun to address by deploying a SISSVoc interface to the NVS), and it has been difficult to aggregate data as multiple PUV terms can - with full validity - be used to describe the same data channels. Better approaches to data aggregation are required as a use case for the PUV from the EC European Marine Observation and Data Network (EMODnet) Chemistry project. One solution, proposed and demonstrated during the course of the NETMAR project, is to build new SKOS concept collections which formalise the desired aggregations for given applications, and uses typed relationships to state which PUV concepts contribute to a specific aggregation. Development of these new collections requires input from a group of experts in the application domain who can decide which PUV

The Endoscopic Morphological Features of Congenital Posterior Urethral Obstructions in Boys with Refractory Daytime Urinary Incontinence and Nocturnal Enuresis.

Science.gov (United States)

Nakamura, Shigeru; Hyuga, Taiju; Kawai, Shina; Kubo, Taro; Nakai, Hideo

2016-08-01

Purpose This study aims to evaluate the endoscopic morphological features of congenital posterior urethral obstructions in boys with refractory daytime urinary incontinence and/or nocturnal enuresis. Patients and Methods A total of 54 consecutive patients underwent endoscopy and were diagnosed with a posterior urethral valve (PUV) (types 1-4). PUV type 1 was classified as severe, moderate, or mild. A transurethral incision (TUI) was mainly performed for anterior wall lesions of the PUV. Voiding cystourethrography and pressure flow studies (PFS) were performed before and 3 to 4 months after TUI. Clinical symptoms were evaluated 6 months after TUI, and outcomes were assessed according to PFS waveform pattern groups (synergic pattern [SP] and dyssynergic pattern [DP]). Results All patients had PUV type 1 and/or 3 (i.e., n = 34 type 1, 7 type 3, and 13 types 1 and 3). There were severe (n = 1), moderate (n = 21), and mild (n = 25) cases of PUV type 1. According to PFS, SP and DP were present in 43 and 11 patients, respectively. TUI was effective in the SP group and symptoms improved in 77.4 and 69.3% of patients with daytime incontinence and nocturnal enuresis, respectively. Almost no effect was observed in the DP group. A significant decrease in the detrusor pressure was observed at maximum flow rate using PFS in the SP group. Conclusions PUV type 1 encompassed lesions with a spectrum of obstructions ranging from severe to mild, with mild types whose main obstructive lesion existed at the anterior wall of urethra occurring most frequently in boys with refractory daytime urinary incontinence and/or nocturnal enuresis. Georg Thieme Verlag KG Stuttgart · New York.

Advantages of fulguration of posterior urethral valves by Nd: YAG laser

Directory of Open Access Journals (Sweden)

D K Gupta

2000-01-01

Full Text Available Posterior Urethral Valves (PUV are one of the com-monest urolgical problems seen in children and the electro-coagulation, which is the most widely preferred modality to ablate the valves, may not be feasible in small-for-date and low-birth-weight neonates as the suitable size resec-toscope/cystoscope may not available. With the availa-bility of Nd: YAG laser at our institute recently, we started performing the laser fulguration instead of electrocoagu-lation of the valves. We reviewed our experience with the emerging role of the Nd: YAG laser in the fulguration of PUV, comparing the results with a historical control group who underwent the classical electrocoagulation of the PUV. The boys (n=50 diagnosed to have PUV by VCUG were confirmed by Wolf 8.5 size cystoscope, underwent Nd: YAG laser fulguration of the valves with a bare fiber, as a day-care procedure without postoperative catheteri-zation. Historical controls (n=50 who had undergone classical electrocoagulation using 9.5 size Wolf resectos-cope served as the controls. The mean age was 1.3 y and 2.6 y in laser and electrocoagulation group respectively. The mean hospital stay of the electrocoagulation group was 3.8 d. Three patients after electrocoagulation devel-oped hematuria and 4 required refulguration whereas in the laser group 5 required refulguration and none devel-oped hematuria. In conclusion, endoscopic laser fulgura-tion of PUV is technically feasible even in neonates and small children. Laser offers excellent results that are com-parable to the time-honored electrocoagulation procedure. This has the additional advantage forfulgurating the PUV in smaller caliber urethra as this can be performed with the smaller available cystoscope that has a side channel, admitting the laser fiber.

Studies on the pathogenesis and survival of different culture forms of Listeria monocytogenes to pulsed UV-light irradiation after exposure to mild-food processing stresses.

Science.gov (United States)

Bradley, Derek; McNeil, Brian; Laffey, John G; Rowan, Neil J

2012-06-01

The effects of mild conventional food-processing conditions on Listeria monocytogenes survival to pulsed UV (PUV) irradiation and virulence-associated characteristics were investigated. Specifically, this study describes the inability of 10 strains representative of 3 different culture forms or morphotypes of L. monocytogenes to adapt to normally lethal levels of PUV-irradiation after exposure to sub-lethal concentrations of salt (7.5% (w/v) NaCl for 1 h), acid (pH 5.5 for 1 h), heating (48 °C for 1 h) or PUV (UV dose 0.08 μJ/cm(2)). Findings showed that the order of increasing sensitivity of L. monocytogenes of non-adapted and stressed morphotypes to low pH (pH 3.5 for 5 h, adjusted with lactic), high salt (17.5% w/v NaCl for 5 h), heating (60 °C for 1 h) and PUV-irradiation (100 pulses at 7.2 J and 12.8 J, equivalent to UV doses of 2.7 and 8.4 μJ/cm(2) respectively) was typical wild-type smooth (S/WT), atypical filamentous rough (FR) and atypical multiple-cell-chain (MCR) variants. Exposure of L. monocytogenes cells to sub-lethal acid, salt or heating conditions resulted in similar or increased susceptibility to PUV treatments. Only prior exposure to mild heat stressing significantly enhanced invasion of Caco-2 cells, whereas subjection of L. monocytogenes cells to combined sub-lethal salt, acid and heating conditions produced the greatest reduction in invasiveness. Implications of these findings are discussed. This constitutes the first study to show that pre-exposure to mild conventional food-processing stresses enhances sensitivity of different culture morphotypes of L. monocytogenes to PUV, which is growing in popularity as an alternative or complementary approach for decontamination in the food environment. Copyright © 2011 Elsevier Ltd. All rights reserved.

Posterior urethral valve with unilateral vesicoureteral reflux and patent urachus: A rare combination of urinary tract anomaliess

Directory of Open Access Journals (Sweden)

Mutiu O Atobatele

2015-01-01

Full Text Available Posterior urethral valve (PUV is a common cause of lower urinary tract obstruction in male infants with an incidence of 1:5000-8000. PUV continues to be a significant cause of morbidity and ongoing renal damage in infants and children. It can coexist with vesicoureteral reflux (VUR in about 50% of cases and also with patent urachus in about one-third of cases. It is a case of a 22-day-old full-term male child who presented with poor urinary stream and progressive abdominal distension of 5-day duration as well as leakage of clear fluid from umbilicus of 1-day duration. Abdominopelvic ultrasonography showed bilateral hydronephrosis. Micturating cystourethrogram also showed features of bladder outlet obstruction and PUV. In addition, a grade V left VUR and a fistulous tract between the dome of the urinary bladder and the umbilicus, which was consistent with a patent urachus was demonstrated. In conclusion, this case demonstrates a rare combination of congenital urinary tract anomalies involving PUV, left VUR and patent urachus.

The effect of melatonin on eye lens of rats exposed to ultraviolet radiation.

Science.gov (United States)

Anwar, M M; Moustafa, M A

2001-05-01

We investigated the influence of exogenously administered melatonin on adult rats eye lenses exposed to ultraviolet radiation (UV) A and B ranging from 356-254 nm irradiation at 8 microW/cm(2). Rats exposed to this range of UV for 15 min for one week showed a significant (PUV-radiation significantly (PUV irradiation, may be the main cause of lens opacification. Melatonin injection with radiation significantly reduced (Pradiation, SOD and GSH-Px enzyme activities increased significantly (PUV radiation was as effective as melatonin treatment concurrent with UV irradiation. We conclude that melatonin may protect the eye lens from the damaging effects of UV exposure, and its actions protect lens from oxidative stress, elevating Ca(2+) levels, which are considered as an important causes of cataractogenesis.

Radiation-induced non-equilibrium redox chemistry of plutonium: implications for environmental migration

International Nuclear Information System (INIS)

Haschke, J.M.; Siekhaus, W.J.

2009-01-01

Static concentrations of plutonium oxidation states in solution and at surfaces in oxide-water systems are identified as non-equilibrium steady states. These kinetically controlled systems are described by redox cycles based on irreversible disproportionation of Pu(IV), Pu(V), and Pu(VI) in OH-bridged intermediate complexes and at OH-covered oxide surfaces. Steady state is fixed by continuous redox cycles driven by radioactivity-promoted electron-transfer and energetically favorable reactions of Pu(III) and Pu(VII) disproportionation products with H2O. A model based on the redox cycles accounts for the high steady-state (Pu) coexisting with Pu(IV) hydrous oxide at pH 0-15 and for predominance of Pu(V) and Pu(VI) in solution. The steady-state (Pu) depends on pH and the surface area of oxide in solution, but not on the initial Pu oxidation state. PuO 2+x formation is attributed to high Pu(V) concentrations existing at water-exposed oxide surfaces. Results infer that migration of Pu in an aqueous environment is controlled by kinetic factors unique to that site and that the predominant oxidation states in solution are Pu(V) and Pu(VI)

Radiological findings of congenital urethral valves

International Nuclear Information System (INIS)

Yeon, Kyung Mo; Kook, Shin Ho

1990-01-01

Congenital urethral valve is the common cause of hydronephrosis in newborn infants and the most common cause of bladder outlet obstruction in male children. We reviewed and analysed radiological findings and associated anomalies of 16 cases of congenital urethral valve which were examined during the period from January 1985 to December 1989. The most frequent age was under one year old (56%). The main symptoms were urinary dribbing (37.5%), weak stream (25%) and urinary frequency and incontinence (25%). Anterior urethral valve (AUV) was 5 cases (31%) and posterior urethral valve (PUV) was 11 cases(69%), in which 10 cases were Type I and one case was Type III. Bladder wall thickening was seen in all cases and its severity was partly correlated with the degree of vesicoureteral reflux (VUR). VUR was observed in 12 cases (75%), and relatively severe in older age group. The degree of VUR was milder in AUV than PUV. Hydronephrosis was more severe in PUV than in anterior one, and its degree was correlated with the severity of VUR. Associated anomalies were ectopic urethral opening (2 cases), PDA (1 case), congenital megacolon (1 case) and patent urachus (1 case) in PUV. So early diagnosis and treatment of congenital urethral valve is essential to the prevention of renal damage

Late presentation of posterior urethral valves.

Science.gov (United States)

Jalbani, Imran Khan; Biyabani, Syed Raziuddin

2014-05-01

Presence of posterior urethral valves (PUV) is the most common cause of urinary tract obstruction in the male neonate. Late presentation occurs in 10% of cases. We present a case of PUVs in an adult male who presented with history of obstructive lower urinary tract symptoms and hematuria. On evaluation, he was found to have raised serum creatinine level. A voiding cystourethrogram (VCUG) could not be completely performed because of narrowing in the posterior urethra. A rigid urethrocystoscopy was performed at which he was found to have type-I posterior urethral valve which were fulgurated. A repeat uroflowmetry revealed maximum flow rate of 12 ml/second. This case highlights that PUVs is not solely a disease of infancy but may also present late. VCUG is the radiological investigation of choice but the diagnosis may be missed. A urethrocystoscopy is advised if there is a high index of suspicion.

Laser ablation of posterior urethral valves by fetal cystoscopy.

Science.gov (United States)

Martínez, José María; Masoller, Narcis; Devlieger, Roland; Passchyn, Esther; Gómez, Olga; Rodo, Joan; Deprest, Jan A; Gratacós, Eduard

2015-01-01

To report the results of fetal cystoscopic laser ablation of posterior urethral valves (PUV) in a consecutive series in two referral centers. Twenty pregnant women with a presumptive isolated PUV were treated with fetal cystoscopy under local anesthesia. Identification and fulguration of the PUV by one or several firing-contacts with diode laser were attempted. Perinatal and long-term outcomes were prospectively recorded. The median gestational age at procedure was 18.1 weeks (range 15.0-25.6), and median operation time was 24 min (range 15-40). Access to the urethra was achieved in 19/20 (95%) cases, and postoperative, normalization of bladder size and amniotic fluid was observed in 16/20 (80%). Overall, there were 9 (45%) terminations of pregnancy and 11 women (55%) delivered a liveborn baby at a mean gestational age of 37.3 (29.1-40.2) weeks. No infants developed pulmonary hypoplasia and all were alive at 15-110 months. Eight (40% of all fetuses, 72.7% of newborns) had normal renal function and 3 (27.3%) had renal failure awaiting renal transplantation. Fetoscopic laser ablation for PUV can achieve bladder decompression and amniotic fluid normalization with a single procedure in selected cases with anyhydramnios. There is still a significant risk of progression to renal failure pre or postnatally. © 2014 S. Karger AG, Basel.

Determination of Pu Oxidation states in the HCl Media Using with UV-Visible Absorption Spectroscopic Techniques

International Nuclear Information System (INIS)

Lee, Myung Ho; Suh, Mu Yeol; Park, Kyoung Kyun; Park, Yeong Jae; Kim, Won Ho

2006-01-01

The spectroscopic characteristics of Pu (III, IV, V, VI) in the HCl media were investigated by measuring Pu oxidation states using a UV-Vis-NIR spectrophotometer (400-1200 nm) after adjusting Pu oxidation states with oxidation/reduction reagents. Pu in stock solution was reduced to Pu(III) with NH 2 OH · HCl, and oxidized to Pu(IV) and Pu(VI) with NaNO 2 and HCIO 4 , respectively. Also, Pu(V) was adjusted in the Pu(VI) solution with NH 2 OH · HCl. The major absorption peaks of Pu (IV) and Pu(III) were measured in the 470 nm and 600 nm, respectively. The major absorption peaks of Pu (VI) and Pu(V) were measured in the 830 nm and 1135 nm, respectively. There was not found to be significant changes of UV-V is absorption spectra for Pu(III), Pu(IV) and Pu(VI) with aging time, except that an unstable Pu(V) immediately reduced to Pu(III).

Plutonium chemistry: a synthesis of experimental data and a quantitative model for plutonium oxide solubility

International Nuclear Information System (INIS)

Haschke, J.M.; Oversby, V.M.

2002-01-01

The chemistry of plutonium is important for assessing potential behavior of radioactive waste under conditions of geologic disposal. This paper reviews experimental data on dissolution of plutonium oxide solids, describes a hybrid kinetic-equilibrium model for predicting steady-state Pu concentrations, and compares laboratory results with predicted Pu concentrations and oxidation-state distributions. The model is based on oxidation of PuO 2 by water to produce PuO 2+x , an oxide that can release Pu(V) to solution. Kinetic relationships between formation of PuO 2+x , dissolution of Pu(V), disproportionation of Pu(V) to Pu(IV) and Pu(VI), and reduction of Pu(VI) are given and used in model calculations. Data from tests of pyrochemical salt wastes in brines are discussed and interpreted using the conceptual model. Essential data for quantitative modeling at conditions relevant to nuclear waste repositories are identified and laboratory experiments to determine rate constants for use in the model are discussed

Influence of iron redox transformations on plutonium sorption to sediments

Energy Technology Data Exchange (ETDEWEB)

Hixon, A.E.; Powell, B.A. [Environmental Engineering and Earth Sciences, Clemson Univ., Clemson, SC (United States); Hu, Y.J.; Nitsche, H. [Dept. of Chemistry, Univ. of California, Berkeley, CA (United States); Lawrence Berkeley National Lab., Berkeley, CA (United States); Kaplan, D.I. [Savannah River National Lab., Aiken, SC (United States); Kukkadapu, R.K.; Qafoku, O. [Pacific Northwest National Lab., Richland, WA (United States)

2010-07-01

Plutonium subsurface mobility is primarily controlled by its oxidation state, which in turn is loosely coupled to the oxidation state of iron in the system. Experiments were conducted to examine the effect of sediment iron mineral composition and oxidation state on plutonium sorption and reduction. A pH 6.3 vadose zone sediment containing iron oxides and iron-containing phyllosilicates was treated with various complexants (ammonium oxalate) and reductants (hydroxylamine hydrochloride and dithionite-citrate-bicarbonate (DCB)) to selectively leach and/or reduce iron oxide and phyllosilicate/clay Fe(III). {sup 57}Fe-Moessbauer spectroscopy was used to identify initial iron mineral composition of the sediment and monitor dissolution and reduction of iron oxides and reduction of phyllosilicate Fe(III). {sup 57}Fe-Moessbauer spectroscopy showed that the Fe-mineral composition of the untreated sediment is: 25-30% hematite, 60-65% small-particle/Al-goethite, and < 10% Fe(III) in phyllosilicate; there was no detectable Fe(II). Upon reduction with a strong chemical reductant (dithionite-citrate-bicarbonate buffer), much of the hematite and goethite was removed. Partial reduction of phyllosilicate Fe(III) was evident in the sediments subjected to DCB treatment. Sorption of Pu(V) was monitored over one week for the untreated and each of five treated sediment fractions. Plutonium oxidation state speciation in the aqueous and solid phases was monitored using solvent extraction, coprecipitation, and XANES. The rate of sorption appears to correlate with the fraction of Fe(II) in the sediment (untreated or treated). Pu(V) was the only oxidation state measured in the aqueous phase, irrespective of treatment, whereas Pu(IV) and much smaller amounts of Pu(V) and Pu(VI) were measured in the solid phase. Surface-mediated reduction of Pu(V) to Pu(IV) occurred in treated and untreated sediment samples; Pu(V) remained on untreated sediment surface for two days before reducing to Pu

Reversibility of sorption of plutonium-239 onto hematite and goethite colloids

International Nuclear Information System (INIS)

Lu, N.; Cotter, C.R.; Kitten, H.D.; Bentley, J.; Triay, I.R.

1998-01-01

Laboratory batch sorption experiments were conducted to evaluate: (1) sorption of plutonium-239 ( 239 Pu) on different iron oxide colloids (hematite and geothite), (2) sorption kinetics of colloidal Pu(IV) and soluble Pu(V) onto these two colloids, and (3) desorption of colloidal Pu(IV) and soluble Pu(V) from 239 Pu-loaded colloids as a function of time. Natural groundwater and carbonate-rich synthetic groundwater were used in this study. To examine the possible influence of bicarbonate on 239 Pu sorption, an additional set of experiments was conducted in sodium nitrate (NaNO 3 ) solutions under carbon dioxide free environments. Our results show that colloidal Pu(IV) as well as soluble Pu(V) was rapidly adsorbed by hematite and goethite colloids in both natural and synthetic groundwater. The amount of 239 Pu adsorbed by both iron oxide colloids in synthetic groundwater was higher than in natural groundwater. The presence of carbonate did not influence the sorption of 239 Pu. While sorption of soluble Pu(V) is a slow process, sorption of colloidal Pu(IV) occurs rapidly. Desorption of Pu from iron oxide colloids is much slower than the sorption processes. Our findings suggest that different sorption and desorption behaviors of 239 Pu by iron oxide colloids in groundwater may facilitate the transport of 239 Pu along potential flowpaths from the areas contaminated by radionuclide and release to the accessible environment. (orig.)

Speciation of actinides in marine waters

International Nuclear Information System (INIS)

Roberts, R.A.

1984-01-01

The oxidation state distribution of plutonium in seawater, pore water from marine sediments, and a series of model solutions similar to seawater was measured using a TTA solvent extraction technique and α liquid scintillation counting methods. Electromigration was used to compare migration behavior of americium in 0.7M NaCl solutions (pH 6.5 to 8.0) with the behavior calculated from predicted speciation. In all pH 8 solutions studied, Pu(VI) was rapidly reduced to Pu(V). In 0.7M NaCl, pH 8.0, and artifical seawater (no organics), the Pu(V) formed was stable. In real seawater (with organic components), a rapid reduction of Pu(VI) to Pu(IV) was also observed. The Pu(V) formed in seawater was metastable; a very slow reduction to Pu(IV) occurred. This reduction was catalyzed by light. Humic acid (obtained from marine sediments from the Bahama Islands), was added to 0.7M NaCl, pH 8.0 solutions to determine its effect on Pu redox reactions. The effect was similar to the reductions in seawater. Increasing the humic acid concentration decreased the amount of Pu(V) which was formed and favored the IV state. The americium electromigration experiments showed a +0.12 net charge for the Am complexes formed in 0.7M NaCl solutions from pH 7.0 to 8.0. This value was smaller than the charge of +0.94 calculated from predicted speciation

Presentation, management, and outcome of posterior urethral valves in a Nigerian tertiary hospital.

Science.gov (United States)

Orumuah, Agbugui Jude; Oduagbon, Obarisiagbon Edwin

2015-01-01

Posterior urethral valves (PUV) remain the most common cause of bladder outlet obstruction and renal insufficiency in male children. The aim of this study was to evaluate the presentation, management, challenges, and outcome of the disease in a Nigerian tertiary health institution. Retrospectively, medical records of male children with a diagnosis of PUVs over a 10 year period (2003-2012) were retrieved. All data in relation to the study objectives were recorded and analyzed. A total of 44 patients was managed for PUV within the period. The mean age of presentation was 3.95 years with 56.8% of the patients presenting after the age of 1 year. Voiding dysfunction noted in 40 (91.0%) patients was the most common mode of presentation. The most common finding on physical examination was a palpable bladder while urinary tract infection noted in 23 (52.3%) patients was the most common complication noted. Abdominal ultrasonography revealed dilated posterior urethra in 16 (36.4%) cases, while micturating cystourethrogram revealed a dilated proximal urethra in all 35 cases in which it was done, diverticulum in 6 and vesicoureteric reflux in 9. The creatinine value at presentation ranged between 0.4 mg/dl and 4.0 mg/dl with a mean of 1.02 ± 0.93 mg/dl. Urethroscopy in 37 patients confirmed type I and type III PUV in 35 and 2 patients, respectively. Valve ablation with a diathermy bugbee electrode provided relief of obstructions in the 37 patients who underwent the procedure without any significant immediate complication. The period of follow-up ranged between 2 weeks and 3 years with a mean of 10.2 months. There was sustained improvement in urine stream, reduction in the mean creatinine concentration and incidence of UTI during follow-up. However, patients with significantly impaired renal function had a poorer outcome. Many patients with PUV presented late within the reviewed period. Valve ablation provided relief of obstruction in most of the cases. There is a need to

A Locally Nonlinear Interpretation of PUV Measurements

Science.gov (United States)

1998-10-01

k ,h s vyk U ygk tanh khs0Ž . Ž .1 a a a cosh k hqzŽ .P obsf v ,k ,h sr g hyp s0Ž .2 a dcosh kh 14Ž .k cosh k hqzŽ .1 UV obsf v ,k ,h sU q vyk U hyu ...s0Ž . Ž .3 a 1 a a 1k sinh kh k cosh k hqzŽ .2 UV obsf v ,k ,h sU q vyk U hyu s0,Ž . Ž .4 a 2 a a 2k sinh kh In principle, a unique local solution at

A Sensitive Detection of Actinide Species in Solutions Using a Capillary Cell

International Nuclear Information System (INIS)

Cho, Hye Ryun; Park, Kyung Kyun; Jung, Euo Chang; Song, Kyu Seok

2009-01-01

Absorption spectra for a quantitative analysis of actinide elements such as U(VI) and Pu(V) were measured by using a liquid waveguide capillary cell (LWCC) which has an optical path length of 1.0 meter. In order to investigate radioactive elements, a LWCC is installed in a glove box and is coupled to a spectrophotometer with optical fibers. Limits of detection (LOD) for the system were determined as 0.74 and 0.35 μM with molar absorption coefficients of 8.14 ± 0.07 (414 nm) and 17.00 ± 0.16 (569 nm) M -1 cm -1 for U(VI) and Pu(V) ions, respectively. The measured LOD values are about 30 times more sensitive when compared to those achievable by using a conventional quartz cell with an optical path length of 1.0 cm. As an application with an enhanced sensitivity, a quantitative analysis for micromolar concentrations of Pu(V) has been performed to decrease the uncertainty in the formation constant of the Pu(VI)-OH complex.

Predicting postnatal renal function of prenatally detected posterior urethral valves using fetal diffusion-weighted magnetic resonance imaging with apparent diffusion coefficient determination.

Science.gov (United States)

Faure, Alice; Panait, Nicoleta; Panuel, Michel; Alessandrini, Pierre; D'Ercole, Claude; Chaumoitre, Kathia; Merrot, Thierry

2017-07-01

The objective of this study was to evaluate the accuracy of fetal diffusion-weighted magnetic resonance imaging with apparent diffusion coefficient (ADC) determination to predict postnatal renal function (nadir creatinine at 1 year and eGFR) of men with posterior urethral valves (PUV). Between 2003 and 2014, 11 MRI were performed on fetuses (between 28 and 32 weeks) in whom second trimester sonography suggested severe bilateral urinary tract anomalies, suspected of PUV. The ADC of the 11 fetuses ranged from 1.3 to 2.86 mm 2  s -1 (median = 1.79 mm 2  s -1 , normal range for fetal kidney: 1.1-1.8). Two pregnancies with ADC > 2.6 mm 2  s -1 were interrupted; the autopsy confirmed PUV and Potter syndrome. For the remaining nine babies, the follow-up was 5.4 years (0.8-10). Four children with abnormal ADC (1.8-2.3) had chronic kidney disease. The remaining five cases with normal nadir creatinine and eGFR had normal ADC. One case with unilateral elevated ADC had a poor ipsilateral renal function on dimercaptosuccinic acid scan. Here, it seems that diffusion-weighted magnetic resonance imaging with ADC determination could be useful in accurately evaluating fetal kidneys in PUV and predicting renal function. It may be an additional, non-invasive method when biologic and sonographic findings are inconclusive, especially in the case of oligohydramnios. Further studies are needed to confirm our data. © 2017 John Wiley & Sons, Ltd. © 2017 John Wiley & Sons, Ltd.

Presentation, management, and outcome of posterior urethral valves in a Nigerian tertiary hospital

Directory of Open Access Journals (Sweden)

Agbugui Jude Orumuah

2015-01-01

Full Text Available Background: Posterior urethral valves (PUV remain the most common cause of bladder outlet obstruction and renal insufficiency in male children. The aim of this study was to evaluate the presentation, management, challenges, and outcome of the disease in a Nigerian tertiary health institution. Patients and Methods: Retrospectively, medical records of male children with a diagnosis of PUVs over a 10 year period (2003-2012 were retrieved. All data in relation to the study objectives were recorded and analyzed. Results: A total of 44 patients was managed for PUV within the period. The mean age of presentation was 3.95 years with 56.8% of the patients presenting after the age of 1 year. Voiding dysfunction noted in 40 (91.0% patients was the most common mode of presentation. The most common finding on physical examination was a palpable bladder while urinary tract infection noted in 23 (52.3% patients was the most common complication noted. Abdominal ultrasonography revealed dilated posterior urethra in 16 (36.4% cases, while micturating cystourethrogram revealed a dilated proximal urethra in all 35 cases in which it was done, diverticulum in 6 and vesicoureteric reflux in 9. The creatinine value at presentation ranged between 0.4 mg/dl and 4.0 mg/dl with a mean of 1.02 ± 0.93 mg/dl. Urethroscopy in 37 patients confirmed type I and type III PUV in 35 and 2 patients, respectively. Valve ablation with a diathermy bugbee electrode provided relief of obstructions in the 37 patients who underwent the procedure without any significant immediate complication. The period of follow-up ranged between 2 weeks and 3 years with a mean of 10.2 months. There was sustained improvement in urine stream, reduction in the mean creatinine concentration and incidence of UTI during follow-up. However, patients with significantly impaired renal function had a poorer outcome. Conclusion: Many patients with PUV presented late within the reviewed period. Valve ablation

Investigations on the structure of complex compounds by radioisotope exchange. The structure of cyanonitrosyl complexes; Recherches sur la structure des complexes par echange de radioisotopes - Structure des complexes cyanonitrosyliques; Issledovanie struktury slozhnykh soedinenij pri pomoshchi radioizotopnogo obmena - struktura slozhnykh tsianonitrozilovykh soedinenij; Estudio de la estructura de complejos por intercambio radioisotopico - Estructura de los complejos cianonitrosilicos

Energy Technology Data Exchange (ETDEWEB)

Jezowska-Trzeblatowska, B; Ziolkowski, J [University of Wroclaw (Poland)

1962-03-15

central y la capa p del atomo de nitrogeno. (author) [Russian] V kachestve slozhnogo svyazuyushchego zvena nitrozilovaya gruppa predstavlyaet osobyj interes kak po svoej strukture, tak i blagodarya svoemu svojstvu obrazovyvat' gruppy NO{sup -} i NO{sup +}. Dlya issledovaniya ehlektronnoj struktury K{sub 3}Mn(CN){sub 6} i K{sub 3}Mn(CN){sub 6}NO, valentnosti metalla i kharaktera soedinenij byli proizvedeny issledovaniya pri pomoshchi metoda radioizotopnogo obmena, a takzhe i drugikh fiziko-khimicheskikh metodov. Bylo obnaruzheno, chto dobavlenie nitrozilovoj gruppy k ionam geksatsionata znachitel'no uvelichivaet ustojchivost' soedineniya kak v tverdom sostoyanii, tak i v rastvore. EHto nablyudenie bylo podtverzhdeno issledovaniem kinetiki obmena v sistemakh: (I) K{sub 3}Mn(CN){sub 6} + KC{sup 14}N; (II) K{sub 3}Mn(CN){sub 5}NO + KC{sup 14}N. V oboikh sluchayakh reaktsii obmena v funktsii vremeni yavlyayutsya reaktsiyami pervogo poryadka, no oni znachitel'no otlichayutsya drug ot druga po skorosti. EHnergii aktivatsii ehtikh reaktsij ravny E{sub 1}=8,5 kilokalorij na molekulu i E{sub 11}=22,8 kilokalorij na molekulu. Anion Mn(CN){sub 5}NO{sub 3} svetochuvstvitelen, tak chto reaktsiya obmena nosit fotokhimicheskij kharakter. Sootnoshenie postoyannykh skorostej obmena v temnote i pri standartizirovannom osveshchenii ravno 1:100. Pervaya reaktsiya obmena (I) proiskhodit po tipu assotsiatsii, togda kak vtoraya reaktsiya (II) sleduet slozhnomu mekhanizmu assotsiatsii i dissotsiatsii. Analiz raspredeleniya aktivnosti mezhdu tsianistymi gruppami, podvergayushchimisya obmenu v sostoyanii izotopnogo ravnovesiya, obnaruzhil identichnost' po men'shej mere chetyrekh tsianistykh grupp. Bol'shaya ustojchivost' nitrozilovykh soedinenij po sravneniyu s geksatsianatami, a takzhe otsutstvie vtorichnykh dissotsiatsij byli podtverzhdeny razlichnymi metodami. Vse ehto ukazyvaet na strukturu NO{sup -} kompleksa. Predydushchie issledovaniya pokazali, chto nitrozilovaya gruppa koordiniruetsya v

Parents' perceptions of counselling following prenatal diagnosis of congenital anomalies of the kidney and urinary tract: a qualitative study.

Science.gov (United States)

Marokakis, Sarah; Kasparian, Nadine A; Kennedy, Sean E

2017-03-01

To explore parents' experiences of counselling after prenatal diagnosis of congenital anomalies of the kidney and urinary tract. Parents of a child born between September 2012 and March 2015 with posterior urethral valves (PUV) or multicystic dysplastic kidney (MCDK) completed a semi-structured telephone interview, demographic survey, and the 21-item self-report Depression, Anxiety and Stress Scales questionnaire. Qualitative data were analysed thematically using NVivo10 software. In all, 17 parents (PUV, eight; MCDK, nine) participated (response rate 40%), and most were offered counselling during pregnancy (14/17). Parents described feelings of shock, fear and uncertainty after diagnosis, and desired early information on all aspects of their child's condition. Most participants were satisfied with the information received; however, unmet information needs relating to treatment and prognosis were identified, particularly amongst fathers and parents in the PUV group. Some parents felt relieved after counselling (12/17); however, emotional distress often persisted long after diagnosis. Parents described a need for written and web-based information resources, specialised psychological services, and parent support groups. While parents valued counselling, many continued to report unmet informational and psychological needs. Early counselling addressing topics important to parents and provision of additional resources and support services may improve parents' adjustment to their baby's diagnosis. © 2016 The Authors BJU International © 2016 BJU International Published by John Wiley & Sons Ltd.

Bardet-biedl syndrome in a child with chronic kidney disease

International Nuclear Information System (INIS)

Valavi, Ehsan; Ahmadzadeh Ali; Ansari, Mohammad Javad Alemzadeh

2009-01-01

A 4-year old boy was referred for evaluation of renal failure, posterior urethral valve (PUV) and urinary tract infection. His parents added complaints of polyuria, polydipsia, enuresis, shortness of stature, and inappropriate obesity. Serum blood urea nitrogen and creatinine levels were 45 and 3.5 mg/dL, respectively. Urine culture was positive for Pseudomonas aeruginosa, and abdominal ultrasound revealed bilateral small kidneys. The patient's history included mild to moderate mental retardation and postaxial polydactyly of both lower limbs amputated two years ago. The combination of mental retardation, obesity, postaxial polydactyly, and bilateral renal hypoplasia were compatible with the diagnosis Bardet-Biedl syndrome (BBS). The combination of PUV and BBS is a rare condition that caused this early onset of renal failure and inappropriate obesity guided us to the diagnosis. (author)

Management of Posterior Urethral Valves in Rural Kenya

African Journals Online (AJOL)

Management of Posterior Urethral Valves in Rural. Kenya .... Antwi S. Audit of Posterior Urethral Valve (PUV) in Children at ... Community Paediatrics Committee, Infectious. Diseases ... Effect of Circumcision on Risk of Urinary Tract. Infection in ...

Urine Blockage in Newborns

Science.gov (United States)

... the ureter joins the kidney. Bladder outlet obstruction (BOO). BOO describes any blockage in the urethra or at ... urethral valves (PUV), the most common form of BOO seen in newborns and during prenatal ultrasound exams, ...

Gastrointestinal absorption of large amounts of plutonium. Effect of valency state on transfer

International Nuclear Information System (INIS)

Lataillade, G.; Duserre, C.; Metivier, H.; Madic, C.; CEA Centre d'Etudes Nucleaires de Fontenay-aux-Roses, 92

1989-01-01

The gastrointestinal absorption of Pu, ingested in valency state III, IV, V or VI was studied in baboons. For each state, the absorption of Pu from masses ranging from 1 to 7 mg per kg of body weight was compared with that from masses ranging from 5 to 45 μg per kg of body weight. The mass ingested did not affect the gastrointestinal absorption of Pu(IV) or PU(VI), but for Pu(V) and to a lesser extent Pu(III), absorption clearly increased about 150-fold and 7-fold respectively, when large masses of Pu were ingested. When small masses were ingested, the valency state did not affect absorption. The increased Pu absorption observed after ingestion of large masses of Pu(V) or (III) might be due to the weak hydrolysis of these valency states. (author)

Bardet-biedl syndrome in a child with chronic kidney disease

Directory of Open Access Journals (Sweden)

Valavi Ehsan

2009-01-01

Full Text Available A 4-year old boy was referred for evaluation of renal failure, posterior urethral valve (PUV and urinary tract infection. His parents added complaints of polyuria, polydipsia, enuresis, shortness of stature, and inappropriate obesity. Serum blood urea nitrogen and creatinine levels were 45 and 3.5 mg/dL, respectively. Urine culture was positive for Pseudomonas aeruginosa, and abdominal ultrasound revealed bilateral small kidneys. The patient′s history included mild to moderate mental retardation and postaxial polydactyly of both lower limbs amputated two years ago. The combination of mental retar-dation, obesity, postaxial polydactyly, and bilateral renal hypoplasia were compatible with the diagnosis Bardet-Biedl syndrome (BBS. The combination of PUV and BBS is a rare condition that caused this early onset of renal failure and inappropriate obesity guided us to the diagnosis.

Predictors and consequences of rural clients' satisfaction level in the district public-private mixed health system of Bangladesh

NARCIS (Netherlands)

Roy, Ashim; van der Weijden, Trudy; de Vries, Nanne

2017-01-01

Background: We investigated predictors of the rural clients' satisfaction level (CSL), and interlinks between perceived specific service quality (PSSQ), perceived utility value (PUV), CSL, and clients' reactions (CR) towards current and future utilization of providers and facilities in the

The maximization of the productivity of aquatic plants for use in controlled ecological life support systems (CELSS)

Science.gov (United States)

Thompson, B. G.

Lemna minor (common duckweed) and a Wolffia sp. were grown in submerged growth systems. Submerged growth increased the productivity/unit volume (P/UV) of the organisms and may allow these plants to be used in a controlled ecological life support system (CELSS).

Effect of Pulsed Ultraviolet Light and High Hydrostatic Pressure on the Antigenicity of Almond Protein Extracts.

Science.gov (United States)

The efficacy of pulsed ultraviolet light (PUV) and high hydrostatic pressure (HHP) on reducing the IgE binding to the almond extracts, was studied using SDS-PAGE, Western Blot, and ELISA probed with human plasma containing IgE antibodies to almond allergens, and a polyclonal antibody against almond ...

Vesicoureteric reflux in children

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Jameela A Kari

2013-01-01

Full Text Available Aim: This study aimed to identify the differences between primary and secondary vesicoureteric reflux (VUR and the effect of associated bladder abnormalities on kidney function. Patients and Methods: We retrospectively reviewed the medical records of children with VUR who were followed up at King Abdulaziz University Hospital from January 2005 to December 2010. The review included results of radiological investigations and kidney function tests. We used Chi-square test for statistical analysis and paired t-test to compare group means for initial and last creatinine levels. Results: Ninety-nine children were included in this study. Twenty (20.2% had primary VUR, 11 had high-grade VUR, while 9 had low-grade reflux. All children with low-grade VUR had normal dimercaptosuccinic acid (DMSA. Renal scars were present in 72% of the children with high-grade VUR. The mean creatinine levels (initial and last for both groups were normal. Seventy-nine (79.8% children had secondary VUR, which was due to posterior urethral valves (PUV (46.8%, neurogenic bladder caused by meningomyelocele (25.3%, non-neurogenic neurogenic bladder (NNB (21.5%, or neurogenic bladder associated with prune belly syndrome (6.3%. Children with NNB, meningomyelocele and PUV had high creatinine at presentation with no considerable worsening of their kidney functions during the last visit. Renal scars were present in 49.4% of the children with secondary VUR. Conclusion: Children with primary VUR and normal bladder had good-functioning kidneys, while those with secondary VUR associated with abnormal bladder caused by NNB, spina bifida or PUV had abnormal kidney functions. DMSA scans were useful in predicting higher grades of VUR in children with primary reflux.

Posterior urethral valve in a six year old boy with nocturnal ...

African Journals Online (AJOL)

We report a case of posterior urethral valve (PUV) in a six year old boy with nocturnal eneuresis and failure to thrive as the only presenting symptoms. The clinically occult lesion was only unravelled when micturating cystourethrogram revealed a dilated posterior urethra with a distal narrow stream of opacified urine, bilateral ...

Anterior urethral valves: not such a benign condition…

Directory of Open Access Journals (Sweden)

Omar eCruz-Diaz

2013-11-01

Full Text Available Purpose: Anterior urethral valves (AUV is an unusual cause of congenital obstruction of the male urethra, being 15 to 30 times less common than posterior urethral valves (PUV. It has been suggested that patients with congenital anterior urethral obstruction have a better prognosis than those with PUV.The long term prognosis of anterior urethral valves is not clear in the literature. In this report we describe our experience and long-term follow up of patients with AUV.Materials and methods: We retrospectively identified 13 patients who presented with the diagnosis of AUV in our institutions between 1994 and 2012. From the 11 patients included, we evaluated the gestational age, ultrasound and voiding cystourethrogram findings, age upon valve ablation, micturition pattern, creatinine and clinical follow up.Results: Between 1994 and 2012 we evaluated 150 patients with the diagnosis of urethral valves, where 11 patients (7.3% had AUV and an adequate follow up. Mean follow up is 6.3 years. 5 patients (45.4% had pre-natal diagnosis of AUV. The most common prenatal ultrasonographic finding was bilateral hydronephrosis and distended bladder.The mean gestational age was 37.6 weeks. Postnatally, 90% had trabeculated bladder, 80% hydronephrosis and 40% renal dysplasia. The most common clinical presentation was urinary tract infection in 5 patients (45.4%.7 patients (63.6% had primary transurethral valve resection or laser ablation and 3 patients (27.2% had primary vesicostomies. One boy (9.1% had urethrostomy with urethral diverticulum excision. 2 patients (18.2% developed end-stage renal disease (ESRD.Conclusions: Early urinary tract obstruction resulted in ESRD in 18% of our patient population. In our series, the complication rate and the evolution to renal failure are high and similar to patients with PUV. In patients with AUV we recommend long-term follow up and close evaluation of patient’s bladder and renal function.

Disinfection and toxicological assessments of pulsed UV and pulsed-plasma gas-discharge treated-water containing the waterborne protozoan enteroparasite Cryptosporidium parvum.

Science.gov (United States)

Hayes, Jennifer; Kirf, Dominik; Garvey, Mary; Rowan, Neil

2013-09-01

We report for the first time on the comparative use of pulsed-plasma gas-discharge (PPGD) and pulsed UV light (PUV) for the novel destruction of the waterborne enteroparasite Cryptosporidium parvum. It also describes the first cyto-, geno- and ecotoxicological assays undertaken to assess the safety of water decontaminated using PPGD and PUV. During PPGD treatments, the application of high voltage pulses (16 kV, 10 pps) to gas-injected water (N2 or O2, flow rate 2.5L/min) resulted in the formation of a plasma that generated free radicals, ultraviolet light, acoustic shock waves and electric fields that killed ca. 4 log C. parvum oocysts in 32 min exposure. Findings showed that PPGD-treated water produced significant cytotoxic properties (as determined by MTT and neutral red assays), genotoxic properties (as determined by comet and Ames assays), and ecotoxic properties (as determined by Microtox™, Thamnotox™ and Daphnotox™ assays) that are representative of different trophic levels in aquatic environment (pozone (0.8 mg/L) and/or dissociated nitric and nitrous acid that contributed to the observed disinfection and toxicity. Chemical analysis of PPGD-treated water revealed increasing levels of electrode metals that were present at ≤ 30 times the tolerated respective values for EU drinking water. PUV-treated water did not exhibit any toxicity and was shown to be far superior to that of PPGD for killing C. parvum oocysts taking only 90 s of pulsing [UV dose of 6.29 μJ/cm(2)] to produce a 4-log reduction compared to a similar reduction level achieved after 32min PPGD treatment as determined by combined in vitro CaCo-2 cell culture-qPCR. © 2013. Published by Elsevier B.V. All rights reserved.

Dual Pathology Causing Congenital Bladder Outlet Obstruction.

Science.gov (United States)

Kwong, Ruth; Johal, Navroop S; Upasani, Anand; Paul, Anu; Cuckow, Peter

2017-12-07

Anterior urethral syringocele is an uncommon congenital deformity characterised by cystic dilatation of bulbo-urethral gland ducts and is usually asymptomatic. We present a case on 4-day-old male neonate who presented with bilateral antenatal hydroureteronephrosis and renal impairment and found to have urethral syringocele and posterior urethral valves (PUV). Copyright © 2017. Published by Elsevier Inc.

A CLINICAL STUDY OF POSTERIOR URETHRAL VALVE AND ITS IMPACT ON RENAL FUNCTION

Directory of Open Access Journals (Sweden)

Nischal Prasad Reddy

2015-05-01

Full Text Available OBJECTIVES: T he most common congenital anomaly is Posterior Urethral valve (PUV and has as incidence of 1 in 8000 male births. It is the most common obstructive cause of end stage renal disease in children. Vesicoureteric reflux, recurrent UTI, voiding dysfunction and late onset renal failure are the long term major problems in these children. There are few long term outcome studies of children with PUV from India. These studies mainly concentrate on the surgical aspects. The study is aimed to assess the long term impact of PUV on renal function and th e growth of these children. METHODS: The study was conducted at AJ hospital, Mangalore between July 2010 - June 2011. Thirty children, with posterior urethral valve, five years or more post - surgery were included in the study. The details of children were obtained from records regarding age, presenting symptoms serum creatinine, presence of or absence of vesicoureteric reflux. Outcomes measured were stunting, renal failure (GFR, tubular functions and bladder functions. Results were analysed. RESULTS: Thirt y children were analysed. The age at presentation varied from antenatal detection to six years. About 46.6% of patients presented between 0 - 1 month, 36.6% between one month to one year, 16.8% between one to six years. The median age at presentation was thr ee months. Primary surgery done in the neonatal period in 33% children. Of the 28 children who had antenatal ultrasound, 20 had normal USS and eight had antenatally detected hydronephrosis (28.6%. Five out of eight had associated oligohydramnios. All thes e five children had GFR <90 m/m/1.73m 2 at follow up. CONCLUSION: Poor bladder function was seen in one - third of patients. Interventions as and when needed on follow - up are important in the management of all children with posterior urethral valve. Comprehen sive care should be the rule by a team comprising paediatrician, pediatric surgeon and pediatric nephrologists

Kimpo-iap K-14, Seoul, Korea. Revised Uniform Summary of Surface Weather Observations (RUSSWO). Parts A-F

Science.gov (United States)

1973-10-30

PTAC , O .10. 5 (O L- ),t ’puv m oso i t~ i ru oe4, , o wixe " DATA PROCESSING BRANCH USAF ETAC W AHRCNIIN AIR WEATHER SERVtCE/MAC W AHRC N IIN...18 19 - 20 21 22 23 24 25. 26 27. 28 29. 30 *31 O.B. WeB . Dry BulbWe, BAIbTDe-wP.n?. 92/ 91 Ct I l ’___ ____ _ _._ 1 _l’.-v ___ QO/ 87 , 913

[Effects of isocitrate lyase from Mycobacterium tuberculosis on the survival of Mycobacterium smegmatis in macrophage and mechanism thereof].

Science.gov (United States)

Li, Jun-Ming; Wan, La-Gen; Zhu, Dao-Yin; Li, Na; He, Yong-Lin; Yang, Chun

2008-02-26

To investigate the effects of isocitrate lyase (ICL) from Mycobacterium tuberculosis (MTB-icl) on the survival of Mycobacterium smegmatis (MS) in macrophage and illuminate the possible mechanisms. MTB-icl gene was amplified by PCR and cloned into Ecoli-Mycobacterium shuttle plasmid pUV15 to obtain recombinant shuttle plasmid pUV15-icl expressing ICL-GFP. The recombinant shuttle plasmid pUV15-icl and blank plasmid pUV15 were induced into MS of the line 1-2c so as to obtain rMS-pUV15-icl and rMS-pUV15. Shuttle plasmid rMS-pUV15-IG expressing ICL-green fluorescent protein (GFP) was constructed. rMS-pUV15-IG and MS 1-2c were used to infect the murine macrophages of the line RAW264.7, fluorescence microscopy was used to observe the expression of ICL-GFP. The expression of ICL in the MS swallowed by the macrophages was verified by RT-PCR and Western blotting. Another macrophages RAW264.7 were cultured and infected with rMS-pUV15-icl and rMS-pUV15 respectively. 0, 24, and 48 hours later macrophages were collected and the number of MS colonies was calculated. The interferon (IFN)-gamma and nitrogen oxide (NO) concentrations in the culture supernatants of macrophages infected by rMS-pUV15-icl and rMS-pUV15 were measured by ELISA and Griess assay respectively. The apoptotic rate of the macrophages was assayed by in situ TUNEL technique. Western blotting showed that the MTB ICL protein expression of the rMS-pUV15-icl was significantly higher than that of rMS-pUVI5. Fluorescence microscopy showed green fluorescence in the RAW264.7 cells infected with rMS-pUV15-IG, but not ion the RAW264.7 cells infected with MS 1-2c. 0 h after the infection of the macrophages there was not significant difference in the MS amount in the macrophages between the rMS-pUV15-isl and rMS-pUV15 groups, and 24 h and 48 h later the MS amounts of the rMS-pUV15-icl group were (32.78 +/- 2.90) x 10(3) and (23.33 + 2.34) x 10(3) respectively, both significantly higher than those of the rMS-pUV15 group [(14

Redox thermodynamic data of plutonium in acidic and carbonate media. Pu(V) stability

International Nuclear Information System (INIS)

Capdevila, H.

1992-01-01

Pu redox equilibria are studied in acidic and carbonate media in this thesis, to build a thermodynamic data bank consistent with the TDB (NEA-OECD) one and in connection with radioactive waste disposal programs. Literature is discussed and reinterpreted. The experimental method is tested with Uranium preliminary measurements. The reversible redox potentials (PuO 2 + and Pu 4+ /Pu 3+ ) are measured using the cyclic voltametric technique in perchloric media at several ionic strengths (from 0.5 to 3M) and temperatures (from 0 to 70 deg C). The Specific Interaction Theory (SIT) is used to measured activity coefficients and to extrapolate data to the standard conditions. The potentials variations versus temperature are linear in first approximation: the entropy changes are found constant from 0 to 70 deg C and the heat capacity changes are within uncertainties. The standard constant of PuO 2 + disproportionation into PuO 2 2+ and Pu 3+ is deduced from spectrophotometric measurements performed in perchloric media around pH=1 where Pu 4+ hydrolysis is discussed. The Pu non-reversible standard potentials (PuO 2 2+ /Pu 4+ for instance) are then calculated and validated with a spectrophotometric study of Pu 4+ formation from PuO 2 2+ and Pu 3+ in a 1M perchloric acidic solution. The Pu(VI/V) redox potential, activity coefficients and entropies are measured using the same technique in concentrated carbonate media. The limiting complex standard formation constants and the redox potential shifts (between acidic and carbonate media) are then discussed among the U, Np, Pu and Am actinides. A spectrophotometric study of the equilibrium between the complexes with 5 and 4 carbonate ligands allowed to measure Pu(IV) limiting complex stability at several ionic strengths. (author). 26 tabs., 46 figs., 95 refs

Testosterone Modifies Alterations to Detrusor Muscle after Partial Bladder Outlet Obstruction in Juvenile Mice

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Andrew S. Flum

2017-06-01

Full Text Available Lower urinary tract symptoms secondary to posterior urethral valves (PUV arise in boys during adolescence. The reasons for this have previously been attributed to increased urine output as boys experience increased growth. Additionally, there are few choices for clinicians to effectively treat these complications. We formed the new hypothesis that increased androgen levels at this time of childhood development could play a role at the cellular level in obstructed bladders. To test this hypothesis, we investigated the role of testosterone on bladder detrusor muscle following injury from partial bladder outlet obstruction (PO in mice. A PO model was surgically created in juvenile male mice. A group of mice were castrated by bilateral orchiectomy at time of obstruction (CPO. Testosterone cypionate was administered to a group of castrated, obstructed mice (CPOT. Bladder function was assessed by voiding stain on paper (VSOP. Bladders were analyzed at 7 and 28 days by weight and histology. Detrusor collagen to smooth muscle ratio (Col/SM was calculated using Masson’s trichrome stain. All obstructed groups had lower max voided volumes (MVV than sham mice at 1 day. Hormonally intact mice (PO continued to have lower MVV at 7 and 28 days while CPO mice improved to sham levels at both time points. In accordance, PO mice had higher bladder-to-body weight ratios than CPO and sham mice demonstrating greater bladder hypertrophy. Histologically, Col/SM was lower in sham and CPO mice. When testosterone was restored in CPOT mice, MVV remained low at 7 and 28 days compared to CPO and bladder-to-body weight ratios were also greater than CPO. Histologic changes were also seen in CPOT mice with higher Col/SM than sham and CPO mice. In conclusion, our findings support a role for testosterone in the fibrotic changes that occur after obstruction in male mice. This suggests that while other changes may occur in adolescent boys that cause complication in boys

pH-dependent Pu interaction of one bacterial isolate from Mont Terri Opalinus Clay

Energy Technology Data Exchange (ETDEWEB)

Moll, Henry; Cherkouk, Andrea [Helmholtz-Zentrum Dresden-Rossendorf e.V., Dresden (Germany). Div. Biogeochemistry

2016-07-01

Sporomusa sp. MT-2.99 cells displayed a strong pH dependent affinity for Pu. Relatively high maximal Pu loadings as for instance 230 mgPu/g{sub dry} {sub biomass} for Sporomusa sp. at pH 6.1 were achieved. A much slower abiotic reduction of Pu(VI) was observed at pH 4 compared to pH 6.1. Independent on pH an enrichment of Pu(V) in the supernatant and of Pu(IV)- polymers on the biomass was discovered.

Urinary Ascites in Newborn – A Rare Case Report

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Suryakant Y. Ingale

2014-01-01

Full Text Available Urinary Ascites in the newborn is a very rare condition. It is commonly secondary to posterior urethral valves (PUV which are membranous folds extending from proximal urethra leading to obstruction to urine flow. Here we report a two days old male neonate delivered full term in a hospital who presented with gross, uniform tense distension of abdomen with massive scrotal oedema, secondary to massive urinary ascites as a result of rupture of renal calyces. In addition there was a peri-renal urinoma.

Nadir creatinine in posterior urethral valves: How high is low enough?

Science.gov (United States)

Coleman, R; King, T; Nicoara, C-D; Bader, M; McCarthy, L; Chandran, H; Parashar, K

2015-12-01

Large retrospective studies of people with posterior urethral valves (PUV) have reported chronic renal insufficiency (CRI) in up to one third of the participants and end-stage renal failure in up to one quarter of them. Nadir creatinine (lowest creatinine during the first year following diagnosis) is the recognised prognostic indicator for renal outcome in PUV, the most commonly used cut-off being 1 mg/dl (88.4 umol/l). To conduct a statistical analysis of nadir creatinine in PUV patients in order to identify the optimal cut-off level as a prognostic indicator for CRI. Patients treated by endoscopic valve ablation at the present institution between 1993 and 2004 were reviewed. Chronic renal insufficiency was defined as CKD2 or higher. Statistical methods included receiver operating characteristic (ROC) curve analysis, Fisher exact test and diagnostic utility tests. Statistical significance was defined as P creatinine was identified in 96 patients. The median follow-up was 9.4 (IQR 7.0, 13.4) years. A total of 29 (30.2%) patients developed CRI, with nine (9.4%) reaching end-stage renal failure. On ROC analysis, Nadir creatinine was highly prognostic for future CRI, with an Area Under the Curve of 0.887 (P creatinine >88.4 umol/l compared with 19 of 86 (22.2%) patients with lower nadir creatinine (P creatinine cut-off of 88.4 umol/l gave a specificity of 100%, but poor sensitivity of 34.5%. Lowering the cut-off to 75 umol/l resulted in improvement in all diagnostic utility tests (Table). All 14 (100%) patients with nadir creatinine >75 umol/l developed CRI, compared with 15 of 82 (18.3%) patients with lower nadir creatinine (P creatinine creatinine >75 umol/l (OR 48.988; CI 4.9-490.11) to be independent risk factors for progression to CRI. Using cut-off values of 35 umol/l and 75 umol/l, patients can be stratified into low-, intermediate- and high-risk groups, with development of CRI in 5.3%, 28.3% and 100%, respectively (P creatinine >75 umol/l (0.85�

Interaction of Desulfovibrio aespoeensis with plutonium

International Nuclear Information System (INIS)

Moll, H.; Merroun, M.; Selenska-Pobell, S.; Bernhard, G.

2005-01-01

Full text of publication follows: Microbes are widely distributed in nature and they can strongly influence the migration of actinides in the environment. Microorganisms in concentrations of 1 x 10 3 to 5 x 10 6 cells ml -1 were estimated by Pedersen et al. in the aquifer system of the Aespoe Hard Rock Laboratory (Aespoe HRL) in Sweden. The number of sulfate-reducing bacteria (SRB) was between 10 1 to 2 x 10 4 cells ml -1 . We investigated the interaction of the SRB Desulfovibrio aespoeensis, DSM 10631 T , with plutonium. The 242 Pu was provided as a mixture of ca. 46% Pu(VI) and ca. 34% Pu(IV)-polymer. Interactions between bacteria and plutonium in mixed oxidation states were not yet intensively investigated. In this study, accumulation experiments were performed in order to obtain information about the amount of the Pu bound by bacteria in dependence on the contact time and the [Pu] initial at pH 5. We used liquid-liquid-extractions and absorption spectroscopy to determine the Pu speciation. In agreement with the results obtained with U(VI) [2] and Np(V), we found a strong dependence of the amount of accumulated Pu with [Pu] initial . Based on our results and taking into consideration the findings of Panak et al. [3], we developed a model describing the interaction of Pu(VI) and Pu(IV)- polymers with D. aespoeensis. In a first step, the Pu(VI) and Pu(IV)-polymers are bound to the biomass. The Pu(VI) is reduced to Pu(V) due to the activity of the cells within the first 24 h of contact time. Most of the formed Pu(V) dissolves due to the weak complexing properties. The dissolved Pu(V) disproportionates to Pu(IV) and Pu(VI) which are then interacting with functional groups of the cell surface structure. Indications were found also for a penetration of Pu species inside the bacterial cells. [1] Pedersen, K.: Microbial processes in radioactive waste disposal. SKB Technical Report TR-00- 04 (2000). [2] Moll, H.; Merroun, M.; Stumpf, Th.; Geipel, G.; Selenska-Pobell, S

Assessment of left ventricular torsion and untwisting in patients suffering from dilated cardiomyopathy by velocity vector imaging

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Xiao-juan ZHANG

2015-10-01

Full Text Available Objective　To evaluate the characteristics of left ventricular twisting (LVtw and untwisting (LVuntw in patients with dilated cardiomyopathy (DCM. Methods　Nineteen DCM patients (aged 18-82 years, mean 50.52±17.52 years, 2 females and 21 normal controls (aged 18-80 years, mean 49.05±16.94 years, 5 females were enrolled in present study. Basal and apical short axis view of two-dimensional images of left ventricle were obtained to analyze LV rotation, and the LV rotation velocity was detected by velocity vector imaging (VVI. LVtw, LVtw velocity, untwisting velocity and untwisting rate (untwR were calculated. Results　The rotated degree and velocity of the basal and apical parts of LV myocardium were irregularly changed along with the cardiac cycle in the DCM group. The rotation degree and rotation velocity at the basal and apex axis decreased in DCM group compared with that in normal group, while the peak of twisting (Ptw [(6.49±1.82°] and the peak of twisting velocity (PTV [(67.84±15.60°/s] decreased significantly in DCM group. The untwR and peak of untwisting velocity (PUV were also decreased significantly in DCM patients. Conclusion　The Ptw, PTV and PUV decrease significantly, and the LV untwR, impacted by the preload, is also decreased significantly in DCM patients. DOI: 10.11855/j.issn.0577-7402.2015.09.13

Future Generation Tactical Engagement Simulation, U.S. Army Prioritized Needs and Recommended Supporting Technology Development. Volume 2

Science.gov (United States)

1988-08-19

a battery box if the MILES torso harness were more like the LCE. Some soldiers wear both the MILES torso harness and the LCE. There have beer ...Meeting at the Army Aviation School, Ft. Rucker, Alabama, May 22, 1986 CW4 Perry Smith Directorate of Training and Doctrine (DOTD) CPT Venjie Gose DOTD Mr...TOPS ses m a 1.54 mienr aeflm Tredinlgy puv in somw aing obemu penstim. of Grimrn beer eWasider. A iWou of *YmbS tIdet. CUfs Pssdi Si Ow seiian "a

Determination of the solubility of Np(IV), Pu(III) - (VI),Am(III) - (VI), and Te(IV), (V) hydroxo compounds in 0.5 - 14 M NaOH solutions

Energy Technology Data Exchange (ETDEWEB)

Delegard, C.H.

1996-09-24

The solubilities of Am(III), Np(IV), Pu(IV), Tc(IV), Np(V), Pu(V), Am(V), and Tc(V) hydroxo compounds were studied in 0.5 to 14 M NaOH solutions at 25{+-}2 {degrees}C. The effects of fluoride, phosphate, carbonate, oxalate, and some other organic complexing agents on the solubilities of Np(IV), Pu(IV), and TC(IV) hydroxides were investigated at 1.0 and 4.0 M NAOH. Some predictions were made on the dissolved (I.V) and (V) species present in alkali solutions.

Challenges of UV light processing of low UVT foods and beverages

Science.gov (United States)

Koutchma, Tatiana

2010-08-01

Ultraviolet (UV) technology holds promise as a low cost non-thermal alternative to heat pasteurization of liquid foods and beverages. However, its application for foods is still limited due to low UV transmittance (LUVT). LUVT foods have a diverse range of chemical (pH, Brix, Aw), physical (density and viscosity) and optical properties (absorbance and scattering) that are critical for systems and process designs. The commercially available UV sources tested for foods include low and medium pressure mercury lamps (LPM and MPM), excimer and pulsed lamps (PUV). The LPM and excimer lamps are monochromatic sources whereas emission of MPM and PUV is polychromatic. The optimized design of UV-systems and UV-sources with parameters that match to specific product spectra have a potential to make UV treatments of LUVT foods more effective and will serve its further commercialization. In order to select UV source for specific food application, processing effects on nutritional, quality, sensorial and safety markers have to be evaluated. This paper will review current status of UV technology for food processing along with regulatory requirements. Discussion of approaches and results of measurements of chemico-physical and optical properties of various foods (fresh juices, milk, liquid whey proteins and sweeteners) that are critical for UV process and systems design will follow. Available UV sources did not prove totally effective either resulting in low microbial reduction or UV over-dosing of the product thereby leading to sensory changes. Beam shaping of UV light presents new opportunities to improve dosage uniformity and delivery of UV photons in LUVT foods.

Subsurface bio-mediated reduction of higher-valent uranium and plutonium

International Nuclear Information System (INIS)

Reed, Donald T.; Pepper, Sarah E.; Richmann, Michael K.; Smith, Geof; Deo, Randhir; Rittmann, Bruce E.

2007-01-01

Bio-mediated reduction of multivalent actinide contaminants plays an important role in their fate and transport in the subsurface. To initiate the process of extending recent progress in uranium biogeochemistry to plutonium, a side-by-side comparison of the bioreduction of uranyl and plutonyl species was conducted with Shewanella alga BrY, a facultative metal-reducing bacterium that is known to enzymatically reduce uranyl. Uranyl was reduced in our system, consistent with literature reports, but we have noted a strong coupling between abiotic and biotic processes and observe that non-reductive pathways to precipitation typically exist. Additionally, a key role of biogenic Fe 2+ , which is known to reduce uranyl at low pH, is suggested. In contrast, residual organics, present in biologically active systems, reduce Pu(VI) species to Pu(V) species at near-neutral pH. The predominance of relatively weak complexes of PuO 2 + is an important difference in how the uranyl and plutonyl species interacted with S. alga. Pu(V) also led to increased toxicity towards S. alga and is also more easily reduced by microbial activity. Biogenic Fe 2+ , produced by S. alga when Fe(III) is present as an electron acceptor, also played a key role in understanding redox controls and pathways in this system. Overall, the bioreduction of plutonyl is observed under anaerobic conditions, which favors its immobilization in the subsurface. Understanding the mechanism by which redox control is established in biologically active systems is a key aspect of remediation and immobilization strategies for actinides when they are present as subsurface contaminants

Local and Nanoscale Structure and Speciation in the PuO{sub 2+x-y}(OH){sub 2y} {center_dot}zH{sub 2}O System

Energy Technology Data Exchange (ETDEWEB)

Conradson, Steven D.; Begg, Bruce D.; Clark, David L.; Den Auwer, Christophe J.; Ding, Mei; Dorhout, Peter K.; Espinosa-Faller, Francisco J.; Gordon, Pamela L.; Haire, Richard G.; Hess, Nancy J.; Hess, Ryan F.; Keogh, D. Webster; Morales, Luis A.; Neu, Mary P.; Paviet-Hartmann, Patricia; Runde, Wolfgang; Tait, C DREW.; Veirs, D. Kirk; Villella, Phillip M.

2004-09-26

Pu L3 X-ray absorption fine structure spectra from 24 samples of PuO{sub 2+x} (and two related Pu substituted oxides), prepared by a variety of methods, demonstrate that (1) although the Pu sublattice remains the ordered part of the Pu distribution, the nearest-neighbor O atoms even at x = 0 are found in a multisite distribution with Pu-O distances consistent with the stable incorporation of OH{sup -} (and possibly H{sub 2}O and H{sup +}) into the PuO{sub 2} lattice; (2) the excess O from oxidation is found at Pu-O distances <1.9 {angstrom}, consistent with the multiply bound ''oxo''-type ligands found in molecular complexes of Pu(V) and Pu(VI); (3) the Pu associated with these oxo groups is most likely Pu(V), so that the excess O probably occurs as PuO{sub 2}{sup +} moieties that are aperiodically distributed through the lattice; and (4) the collective interactions between these defect sites most likely cause them to cluster so as give nanoscale heterogeneity in the form of domains that may have unusual reactivity, observed as sequential oxidation by H{sub 2}O at ambient conditions. The most accurate description of PuO{sub 2} is therefore actually PuO{sub 2+x-y}(OH){sub 2y} {center_dot} zH{sub 2}O, with pure, ordered, homogeneous PuO{sub 2} attained only when H{sub 2}O is rigorously excluded and the O activity is relatively low.

Reactions of plutonium with aceto-hydroxamic acid in aqueous solutions: first results

Energy Technology Data Exchange (ETDEWEB)

Butler, R.J.; Renshaw, J.C.; Collison, D.; Livens, F.R. [Manchester Univ. (United Kingdom). Dept. of Chemistry; Sinkov, S.; Choppin, G.R. [Florida State Univ., Tallahassee, FL (United States). Dept. of Chemistry; Taylor, R.J. [BNFL, Research and Technology, Sellafield, Seascale, Cumbria (United Kingdom)

2000-07-01

Optical spectroscopy has been used to follow the complexation reactions of Pu(IV) and Pu(VI) with the acetohydroxamate (AHA{sup -}) ligand. Significant reduction of Pu(IV) to Pu(III) occurs in the course of the experiment, although the experimental procedure has now been modified to suppress this and will allow Pu(IV)-AHA stability constants to be calculated. In the case of the Pu(VI)-AHA reaction, significant reduction occurs immediately, forming successively Pu(V), Pu(IV) and eventually Pu(III). This reaction was followed for 6 days, by which time Pu(VI) was quantitatively reduced to Pu(III). (authors)

Reactions of plutonium with aceto-hydroxamic acid in aqueous solutions: first results

International Nuclear Information System (INIS)

Butler, R.J.; Renshaw, J.C.; Collison, D.; Livens, F.R.

2000-01-01

Optical spectroscopy has been used to follow the complexation reactions of Pu(IV) and Pu(VI) with the acetohydroxamate (AHA - ) ligand. Significant reduction of Pu(IV) to Pu(III) occurs in the course of the experiment, although the experimental procedure has now been modified to suppress this and will allow Pu(IV)-AHA stability constants to be calculated. In the case of the Pu(VI)-AHA reaction, significant reduction occurs immediately, forming successively Pu(V), Pu(IV) and eventually Pu(III). This reaction was followed for 6 days, by which time Pu(VI) was quantitatively reduced to Pu(III). (authors)

The absorption spectra of Pu(VI), -(V) and -(IV) produced electrochemically in carbonate-bicarbonate media

International Nuclear Information System (INIS)

Wester, D.W.; Sullivan, J.C.

1983-01-01

Absorption spectra in carbonate and bicarbonate media have been measured for various oxidation states of plutonium. The oxidation state of plutonium was adjusted electrochemically (Pu(VI)-V), Esub(f)=+0.11 V vs. SCE) to avoid contamination by redox reagents. In carbonate medium the spectra of Pu(VI) and Pu(V) showed marked differences from the spectra of the same oxidation state in acidic solutions. In bicarbonate the spectra of Pu(VI) and Pu(IV) also differed from the corresponding spectra in acidic media. Reduction to Pu(III) resulted in a precipitate in both carbonate and bicarbonate media. (author)

Chemistry of tetravalent plutonium and zirconium. Hydrolysis, solubility, colloid formation and redox reactions

International Nuclear Information System (INIS)

Cho, Hye-Ryun

2006-01-01

in acidic condition, the concentration of each oxidation state of Pu must be determined prior to each experiment. The solubility data are determined directly after preparation and then the redox reactions between four different plutonium oxidation states are observed at different pH and Pu concentrations as a function of time. The results indicate that the redox behavior of Pu cannot be described by disproportionation of Pu alone. Under the experimental conditions, the redox reactions of Pu seem to be divided into two groups, Pu(IV) aq <-> Pu(III) aq and Pu(IV) coll <-> Pu(V) aq <-> Pu(VI) aq . In the Pu solution containing initially only Pu(IV), the reduction of Pu(IV) to Pu(III) aq dominates rather than the oxidation to Pu(V) aq and Pu(VI) aq . The observed two groups of reactions show the dependency of pH due to the related hydrolysis and colloid formation of Pu(IV). With increasing pH, the [Pu 4+ ] decreases either through its hydrolysis and colloid formation (increase of Pu(IV) coll ) or through its reduction (increase of Pu(III) aq ). The polymer species or colloids may dissolve to Pu(V)aq through the second reaction group (increase Pu(V) aq + Pu(VI) aq ). Consequently, it is observed that with increase of pH, [Pu(IV) aq ] decreases, [Pu(III) aq ] increases, and [Pu(IV) coll ]+[Pu(V) aq ]+[Pu(VI) aq ] increases. This study is also performed under inert gas conditions in order to investigate the influence of dissolved oxygen on the oxidation of Pu(IV) (Pu(IV) coll <-> Pu(V) aq ). From the relative abundance of the Pu oxidation states, namely the couples PuO 2 2+ /PuO 2 + and PuO 2 + /Pu(IV) coll , the redox potential Eh(V) can be obtained. The respective values agree well with the measured Eh values. In order to use the redox couple Pu 4+ /Pu 3+ , one has to take into account the strong hydrolysis of Pu(IV) which sets in below pH 1. When the abundance of Pu 4+ is calculated from the amount of [Pu(IV) aq. ]=[Pu 4+ ]+ sum y=1 4 [Pu(OH) y 4-y ] by use of hydrolysis

Chemical Changes Induced by Irradiation in Meats and Meat Components; Transformations Chimiques Provoquees par les Rayonnements dans les Viandes et Leurs Constituants; Khimicheskie prevrashcheniya v myasnykh produktakh i ikh sostavnykh chastyakh pod vozdejstviem oblucheniya; Alteraciones Quimicas Producidas por Irradiacion de las Carnes y de sus Componentes

Energy Technology Data Exchange (ETDEWEB)

Merritt, C. Jr. [Pioneering Research Division, United States Army Natick Laboratories, Natick, MA (United States)

1966-11-15

'ju konservacii otrazhaetsja na vkusovyh kachestvah, vyzyvaja pojavlenie specificheskogo privkusa i zapaha. Polagajut, chto jeto ob{sup j}asnjaetsja obrazovaniem letuchih himicheskih soedinenij pri dejstvii radiacii na belki i lipidnye molekuly. Analiz letuchih soedinenij osushhestvljaetsja na gazovom hromatografe s kriogennym ohlazhdeniem do zadannoj temperatury, gde proishodit razdelenie slozhnyh smesej. Identifikacija vydelennyh komponentov provoditsja s pomoshh'ju mass-spektrometrii s bystrym skennirovaniem. Proveden ischerpyvajushhij analjz letuchih soedinenij, vydeljajushhihsja iz govjadiny, svininy, baraniny i teljatiny, kotorye byli oblucheny, a takzhe analiz letuchih soedinenij, obrazujushhihsja pri razlozhenii pod dejstviem obluchenija nekotoryh aminokislot, belkov, zhivotnogo zhira, metilovyh jefirov zhirnyh kislot i trigliceridov. Rezul'taty analizov obluchennyh komponentov mjasnyh produktov sravnivajutsja s rezul'tatami, poluchennymi pri obluchenii samogo mjasa i ego otdel'nyh frakcij, chto daet vozmozh - nost' ustanovit' rol' kazhdoj frakcii v celom. Postulirujutsja mehanizmy obrazovanija letuchih komponentov ot kazhdoj frakcii, a takzhe vzaimodejstvie promezhutochnyh produktov ot razlichnyh frakcij. (author)

``Distribution and behaviour of plutonium in the waters of the channel and of the seine estuary``; ``Distribution et comportement du plutonium dans les eaux de la manche et de l`estuaire de la seine``

Energy Technology Data Exchange (ETDEWEB)

Garcia, K

1998-12-31

Excess dissolved plutonium has been measured in the coastal waters of the Channel, from Granville to Boulogne, probably due to sorption-desorption processus. In the Seine estuary, in situ measurements and experimental studies showed that the plutonium desorbs himself from particles in low salinity waters. The desorbed plutonium originates in marine and/or fluvial dissolved Pu. Marine dissolved Pu(V), originating from La Hague plant discharges and from atlantic waters, is reduced and sorbed when the salinity decreases onto estuarial particles: Isotopic Activity Ration {sup 238}Pu/{sup 239}, Pu(IR) of marine dissolved Pu(V) is about 0.7. Fluvial dissolved plutonium originates from atmospheric fallout and from an internal river source: fallout plutonium (IR=0.05) is unreactive with salinity while 45% of river plutonium (IR>1.7) flocculates at 0.5 g l{sup -1}. Desorbed plutonium may have various origins, depending on the Seine liquid discharges and on the tidal coefficient. When the marine waters do not migrate upstream, the low salinity waters encounters particles marked essentially with marine plutonium and the IR of desorbed Pu is about 0.7. The activities of desorbed plutonium are too low to have any influence on the distribution of plutonium in the coastal waters on the Seine Bay. When the marine waters migrate upstream, the low salinity waters meet particles marked essentially with river plutonium (IR>1.7) and desorbed plutonium has a very high IR. These estuarine conditions are encountered five to seven month a year and implicate an increase of the IR of 0.1 of the plutonium present in the coastal waters of the Seine bay (1.2.-1.3.). (author).

''Distribution and behaviour of plutonium in the waters of the channel and of the seine estuary''

International Nuclear Information System (INIS)

Garcia, K.

1997-01-01

Excess dissolved plutonium has been measured in the coastal waters of the Channel, from Granville to Boulogne, probably due to sorption-desorption processus. In the Seine estuary, in situ measurements and experimental studies showed that the plutonium desorbs himself from particles in low salinity waters. The desorbed plutonium originates in marine and/or fluvial dissolved Pu. Marine dissolved Pu(V), originating from La Hague plant discharges and from atlantic waters, is reduced and sorbed when the salinity decreases onto estuarial particles: Isotopic Activity Ration 238 Pu/ 239 , Pu(IR) of marine dissolved Pu(V) is about 0.7. Fluvial dissolved plutonium originates from atmospheric fallout and from an internal river source: fallout plutonium (IR=0.05) is unreactive with salinity while 45% of river plutonium (IR>1.7) flocculates at 0.5 g l -1 . Desorbed plutonium may have various origins, depending on the Seine liquid discharges and on the tidal coefficient. When the marine waters do not migrate upstream, the low salinity waters encounters particles marked essentially with marine plutonium and the IR of desorbed Pu is about 0.7. The activities of desorbed plutonium are too low to have any influence on the distribution of plutonium in the coastal waters on the Seine Bay. When the marine waters migrate upstream, the low salinity waters meet particles marked essentially with river plutonium (IR>1.7) and desorbed plutonium has a very high IR. These estuarine conditions are encountered five to seven month a year and implicate an increase of the IR of 0.1 of the plutonium present in the coastal waters of the Seine bay (1.2.-1.3.). (author)

Posterior urethral valves: 10 years audit of epidemiologic, diagnostic and therapeutic aspects in Yaoundé gynaeco-obstetric and paediatric hospital.

Science.gov (United States)

Tambo, Faustin Felicien Mouafo; Tolefac, Paul Nkemtendong; Ngowe, Marcelin Ngowe; Minkande, Jacqueline Ze; Mbouche, Landry; Guemkam, Georgette; Telelen, Neville Alemnju; Angwafo, Fru Fobuzshi; Sosso, Aurelien Maurice

2018-05-21

The incidence of posterior urethral valve (PUV) is estimated at 1:5000-1:8000 males. It is the most common paediatric urologic urgency and the most common cause of male obstructive uropathy and chronic renal failure in children. The study aimed to describe the experience of Yaoundé gynaeco-obstetrics and paediatric hospital in the management of PUV. Retrospectively, medical records were retrieved over a ten year period and all data recorded and analyzed for study objectives. Patients were called and evaluated for outcomes regarding morbidity and mortality. A total of 18 patients all males were managed over the ten year period, given prevalence of 13 cases/100,000 admissions and an admission rate of 2 per annum. The median age at presentation was 22 months and 13 (72.2%) participants presented late. Voiding urethrocystogram was done in all the participants where it showed dilated and elongated posterior urethral valves in 16 (88.9%) of the cases. Endoscopic valve ablation resulted in the relief of obstruction in all but 3 (16.7%) participants that had residual valves and 2 (11.2%) participants that had urethral stenosis. Type I valves were most common in 14 (78.0%) participants. The mean duration of follow up was 34.56 ± 21.47 months. Complications at final follow up were: 10 (55.6%) chronic renal failure, 2 (11.2%) end-stage renal failure. The case fatality rate was 5.6%. Many patients present late in our setting with already established complications. There is the need to counsel parents/guardians on the importance of long-term follow up after relief of obstruction.

Claims Protection in Construction Contracting.

Science.gov (United States)

1982-01-01

cotifAca 4’O or P04F oa &ACKPI&LOO QP/W SWiO GAIY. ADo 94Y1A16 ovat rRecos vor s.4, 0, W coq~mct. AIITU AWA -MVA4 A 3~ ~ ~ ~ puvR 17ear Cvtow AiD MftR 7W A/W...sequence (from the schedule) 4. Trends in project correspondence (look for the.3 start of a "paper record"). 42 sLou *- Wih I ons90;9 1 -;111. L With 15mm...competence is a risk that must be shared by each party, as they each have their own set of managers. It is an ongoing challenge for each organization to

Neptunium (V) Adsorption to a Halophilic Bacterium Under High Ionic Strength Conditions: A Surface Complexation Modeling Approach

Energy Technology Data Exchange (ETDEWEB)

Ams, David A [Los Alamos National Laboratory

2012-06-11

Rationale for experimental design: Np(V) -- important as analog for Pu(V) and for HLW scenarios; High ionic strength -- relevant to salt-based repositories such as the WIPP; Halophilic microorganisms -- representative of high ionic strength environments. For the first time showed: Significant adsorbant to halophilic microorganisms over entire pH range under high ionic strength conditions; Strong influence of ionic strength with increasing adsorption with increasing ionic strength (in contrast to trends of previous low ionic strength studies); Effect of aqueous Np(V) and bacterial surface site speciation on adsorption; and Developed thermodynamic models that can be incorporated into geochemical speciation models to aid in the prediction of the fate and transport of Np(V) in more complex systems.

Author's reply to 'Comment on 'Plutonium chemistry: a synthesis of experimental data and a quantitative model for plutonium oxide solubility' by J.M. Haschke and V.M. Oversby'

International Nuclear Information System (INIS)

Haschke, John M.

2004-01-01

In the accompanying letter, Newton and Hobart comment on a recent paper [J. Nucl. Mater. 305 (2002) 187] and conclude that a proposed alternative explanation for self-reduction of Pu(VI) is based on misinterpretation of data. Result of quantitative kinetic modeling contradicts this conclusion and the accepted explanation by showing that self-induced α-particle reduction of 239 Pu(VI) at pH 1.5 does not account for the observed reduction rate of Pu(VI) or for dependence of the rate on [Pu(VI)]. Similar modeling shows that kinetic behavior is consistent with a self-reduction process based on disproportionation of Pu(VI). Validity of the alternative concept is supported by close similarities in the kinetic behavior of Pu(V) and Pu(VI)

Simulation study of the chemical forms of neptunium and plutonium in groundwater from a borehole in the northwest region

International Nuclear Information System (INIS)

Ma Yingming; Jin Yuren; Wang Zhiqiang; Liu Dongxu; Liu Wei; Liu Yan

2009-01-01

According to physics-chymistry characteristic of groundwater from a borehole in the northwest region, we performed simulation study of the chemical forms of neptunium and plutonium by the geochemistry modeling program EQ3/6. The main conclusions are as follows: the main chemical form of neptunium in the groundwater is Np(V)'s NpO 2 + , subordination chemical forms are NpO 2 Cl, NpO 2 CO 3 - , NpO 2 OH, NpO 2 SO 4 - ; the main existing form of plutonium in the groundwater is Pu(IV)'s Pu(OH)5-and subordination chemical form is Pu(V)'s PuO 2 + . In addition,the temperature, pH and Eh also have different impacts on the chemical form of neptunium and plutonium. (authors)

Determination of Radiotracer Stability of Tritium-Labelled Compounds in Biological Studies; Determination de la Stabilite des Composes Trities Employes comme Indicateurs en Biologie; 041e 043f 0440 0435 0434 0414 043b ; Determinacion de la Estabilidad de los Compuestos Tritiados en los Estudios Biologicos Mediante Indicadores

Energy Technology Data Exchange (ETDEWEB)

Okita, G. T.; Spratt, J. L. [Argonne Cancer Research Hospital and Department of Pharmacology, University of Chicago, Chicago, IL (United States)

1962-02-15

compuestos marcados hasta lograr una actividad especifica constante no excluye la posibilidad de que en los organismos vivos se produzca un intercambio entre atomos de tritio y de hidrogeno. La estabilidad radiotrazadora puede demostrarse mediante diversos metodos, una vez que se haya efectuado una purificacion radioquimica meticulosa de la sustancia marcada. En la memoria se describen tres metodos diferentes utilizados para determinar la estabilidad radiotrazadora de los compuestos de tritio. Uno de ellos consiste en comparar el periodo biologico de un compuesto de {sup 3}H con el de un compuesto similar marcado con {sup 14}C. Este metodo es aplicable especialmente a las sustancias endogenas que sufren una dilucion isotopica al ser administradas a los animales. La estabilidad de los compuestos exogenos puede comprobarse mediante un segundo metodo, con arreglo al cual basta demostrar que no se produce disminucion de la actividad especifica cuando la sustancia marcada se aisla de nuevo de las muestras biologicas. Un tercer metodo, mas rapido que el primero, y aplicable tanto a las sustancias endogenas como exogenas, consiste en determinar la razon isotopica {sup 3}H/{sup 14}C en una mezcla del mismo compuesto marcado con ambos isotopos. La constancia de las razones isotopicas antes de administrar la sustancia doblemente marcada y despues de aislarla de nuevo de organos o excreta constituye una prueba de su estabilidad radiotrazadora. Este metodo es aplicable especialmente en los casos en que el aislamiento de vestigios de sustancia exige el empleo de un portador inactivo. En la memoria se presentan datos relativos al empleo de estos metodos para la comprobacion de la estabilidad radiotrazadora, con especial referencia al colesterol, la morfina y la digitoxina marcadas, como ejemplos de los tres metodos mencionados. (author) [Russian] Rasprostranivsheesja za poslednee vremja v biologicheskih issledovanijah shirokoe primenenie mechen- nyh tritiem soedinenij vyzyvaet

Interactions of Microbes found at Aespoe Underground Lab with Actinides such as Curium, Plutonium and Uranium

Energy Technology Data Exchange (ETDEWEB)

Moll, H.; Merroun, M.; Geipel, G.; Rossberg, A.; Hennig, C.; Selenska-Pobell , S.; Bernhard, G. [Forschungszentrum Dresden-Rossendorf e.V., Inst. fuer Radioc hemie, 01314 Dresden (Germany)]. e-mail: h.moll@fzd.de; Stumpf, Th. [Forschungszentru m Karlsruhe, Inst. fuer Nukleare Entsorgung, 76021 Karlsruhe (Germany)

2007-06-15

Sulfate-reducing bacteria (SRB) frequently occur in the deep granitic rock aquifers at the Aespoe Hard Rock Laboratory (Aespoe HRL), Sweden. The new SRB strain Desulfovibrio aespoeensis could be isolated. Results describing the basic interaction mechanisms of uranium, curium, and plutonium with cells of D. aespoeensis DSM 10631T will be presented. The interaction experiments with the actinides showed that the cells are able to remove all three actinides from the surrounding solution. The amount of removed actinide and the interaction mechanism varied among the different actinides. The main U(VI) removal occurred after the first 24 h. The contact time, pH and [U(VI)]initial influence the U removal efficiency. The presence of uranium caused a damaging of the cell membranes. TEM revealed an accumulation of U inside the bacterial cell. D. aespoeensis are able to form U(IV). A complex interaction mechanism takes place consisting of biosorption, bioreduction and bioaccumulation. In the case of {sup 242}Pu, solvent extractions, UV-vis- and XANES spectroscopy were used to determine the speciation of the Pu oxidation states. In the first step, the Pu(VI) and Pu(IV)-polymers are bound to the biomass. Solvent extractions showed that 97 % of the initially present Pu(VI) is reduced to Pu(V) due to the activity of the cells within the first 24 h. Most of the formed Pu(V) dissolves from the cell envelope back to the aqueous solution due to the weak complexing properties of this plutonium oxidation state. In the case of curium at a much lower metal concentration of 3x10{sup -7} M, a pure biosorption of Cm(III) on the cell envelope forming an inner-sphere surface complex most likely with organic phosphate groups was detected. To summarize, the strength of the interaction of D. aespoeensis with the selected actinides at pH 5 and actinide concentrations = 10 mg/L ([Cm] 0.07 mg/L) follows the pattern: Cm > U > Pu >> Np.

11-year field study of Pu migration from Pu III, IV, and VI sources

International Nuclear Information System (INIS)

Kaplan, D.I.; Serkiz, S.M.; Demirkanli, D.I.; Gumapas, L.; Fjeld, R.A.; Molz, F.J.; Powell, B.A.

2005-01-01

Full text of publication follows: Understanding the processes controlling Pu mobility in the subsurface environment is important for estimating the amount of Pu waste that can be safely disposed in vadose zone burial sites. To study long-term Pu mobility, four 52-L lysimeters filled with sediment collected from the Savannah River Site near Aiken South Carolina were amended with well characterized solid Pu sources (Pu III Cl 3 , Pu IV (NO 3 ) 4 , Pu IV (C 2 O 4 ) 2 , and Pu VI O 2 (NO 3 ) 2 ) and left exposed to natural precipitation for 2 to 11 years. Pu oxidation state distribution in the Pu(III) and Pu(IV) lysimeters sediments (a red clayey sediment, pH = 6.3) were similar, consisting of 0% Pu(III), >92% Pu(IV), 1% Pu(V), 1% Pu(VI), and the remainder was a Pu polymer. These three lysimeters also had near identical sediment Pu concentration profiles, where >95% of the Pu remained within 1.25 cm of the source after 11 years; moving at an overall rate of 0.9 cm yr -1 . As expected, Pu moved more rapidly through the Pu(VI) lysimeter, at an overall rate of 12.5 cm yr -1 . Solute transport modeling of the sediment Pu concentration profile data in the Pu(VI) lysimeter indicated that some transformation of Pu into a much less mobile form, presumably Pu(IV), had occurred during the course of the two year study. This modeling also supported previous laboratory measurements showing that Pu(V) or Pu(VI) reduction was five orders of magnitude faster than corresponding Pu(III) or Pu(IV) oxidation. The slow oxidation rate (1 x 10-8 hr -1 ; t 1/2 = 8,000 yr) was not discernable from the Pu(VI) lysimeter data that reflected only two years of transport but was readily discernable from the Pu(III) and Pu(IV) lysimeter data that reflected 11 yr of transport. (authors)

The Role of Diffusion Measurements in the Study of Crystal Lattice Defects; Role des Mesures de la Diffusion dans l'Etude des Defauts des Reseaux Cristallins; Rol' diffuzionnykh izmerenij v izuchenii defektov kristallicheskikh reshetok.rol' diffuzionnykh izmerenij v izuchenii defektov kristallicheskikh reshetok; Las Mediciones de la Difusion en el Estudio de Defectos de los Reticulados Cristalinos

Energy Technology Data Exchange (ETDEWEB)

Kidson, G. V. [Chalk River Nuclear Laboratories, ON (Canada)

1966-02-15

Measurements of atomic mobility in solids are frequently of direct interest to those concerned with the design, development and utilization of materials in engineering. Increasing attention, however, is currently devoted to an understanding of such properties in terms of the occurrence and nature of point and line defects in the crystals. This paper reviews some recent diffusion studies conducted at CRNL that provide, in addition to data of interest in nuclear technology, a means of gaining some insight into the more fundamental nature of the lattice defects occurring in the materials. The systems discussed are (i) self diffusion in the high temperature phase of pure zirconium, (ii) solute diffusion in lead, and (iii) interdiffusion of aluminium and zirconium. The unusual and at present incompletely understood results described in (i) are briefly reviewed. Evidence is given to suggest that diffusion occurs either through a dense dislocation network produced as a result of a martensitic phase transformation, or, alternatively, by excess vacancies introduced into the crystal by impurities. In (ii) the extraordinarily rapid diffusion of noble metal solutes in high-purity lead single crystals will be discussed in terms of the state of solution of the solute atoms. It will be shown that their diffusion behaviour can be understood by assuming that a fraction f{sub i} of the dissolved solute atoms occupy interstitial sites. The measured diffusion coefficient D{sub m} is related to the interstitial diffusion coefficient by D{sub m} = f{sub i}D{sub i}. In (iii) the formation and rapid growth of a single intermetallic compound ZrAl{sub 3} in the diffusion zone formed between pure zirconium and pure aluminium is described and the diffusion mechanism is interpreted in terms of the structure of the compound lattice. The results indicate that ZrAl{sub 3} forms a defect lattice, leading to the relatively rapid migration of aluminium atoms. (author) [French] Les mesures du transport atomique dans les solides presentent souvent un interet direct pour les ingenieurs specialises dans l'etude, la mise au point et l'utilisation de materiaux. Actuellement on s'efforce de plus en plus d'aboutir a la comprehension de ces proprietes en fonction de l'apparition et la nature de defauts ponctuels et lineaires dans les cristaux. Le memoire fait le point de certaines etudes de diffusion effectuees recemment a Chalk River; ces travaux non seulement fournissent des resultats importants pour la technologie nucleaire, mais permettent egalement de mieux comprendre la nature des defauts de reseaux que l'on rencontre dans les materiaux. Les questions etudiees sont: a) l'autodiffusion dans la phase de zirconium pur a haute temperature; b) la diffusion d'un solute dans le plomb; c) l'interdiffusion de l'aluminium et du zirconium. L'auteur discute brievement les resultats assez surprenants et encore imparfaitement compris qui sont decrits sous a). Certaines indications donnent a penser que la diffusion se produit soit par un reseau serre de dislocation resultant d'une transformation de la phase martensitique, soit par un excedent de lacunes provoquees dans le cristal par des impuretes. Sous b), l'auteur discute la diffusion extraordinairement rapide des solutes de metaux nobles dans des monocristaux de plomb de grande purete selon l'etat de solution des atomes du solute. Il montre que Ton peut comprendre leur comportement de diffusion si l'on admet qu'une fraction f Inverted-Question-Mark des atomes dissous du solute occupe des sites interstitiels. Le coefficient de diffusion mesure D{sub m} et le coefficient de diffusion interstitielle sont lies par la relation D{sub m} = f{sub i}D{sub i}. Sous c), l'auteur decrit la formation et la croissance rapide d'un compose intermetallique unique ZrAl{sub 3} dans la zone de diffusion formee entre le zirconium et l'aluminium purs et il interprete le mecanisme de diffusion en fonction de la structure du reseau compose. Il ressort des resultats que ZrAl{sub 3} forme un reseau de defauts entrafhant la migration relativement rapide des atomes d'aluminium. (author) [Spanish] Las mediciones de movilidad atomica en solidos suelen presentar interes directo para quienes trabajan en el proyecto, desarrollo y utilizacion de materiales en ingenieria. En la actualidad, sin embargo, existe un interes cada vez mayor por comprender esas propiedades en funcion de la presencia y la fndole de defectos puntiformes y lineales en los cristales. La presente memoria pasa revista a algunos estudios de difusion realizados recientemente en los Chalk River Nuclear Laboratories; ademas de aportar datos de interes para la tecnologfa nuclear, esos estudios contribuyen a un mejor conocimiento de la fndole de los defectos reticulares que aparecen en los materiales. Los aspectos analizados son: i) autodifusion en la fase de alta temperatura del circonio puro; ii) difusion del soluto en plomo; iii) interdifusion de aluminio y circonio. Se pasa breve revista a los resultados algo sorprendentes y todavfa no del todo comprendidos, descritos en i). Se presentan puebas que sugieren que la difusion se produce, ya sea en virtud de una densa red de dislocacion originada por una transformacion de la fase martensftica, ya por un exceso de huecos introducidos en el cristal por obra de las impurezas. En ii) se analiza la difusion extraordinariamente rapida de solutos de metales nobles en monocristales de plomo de alta pureza, en funcion del estado de disolucion de los atomos del soluto. Se demuestra que la difusion puede comprenderse suponiendo que una fraccion f{sub i} de los atomos disueltos del soluto ocupan lugares intersticiales. El coeficiente de difusion medido Dm se relaciona con el coeficiente de difusion intersticial mediante la expresion D{sub m} = f{sub i}D{sub i}. En iii) se describe la formacion y el rapido crecimiento de un compuesto intermetalico uenico ZrAl{sub 3} en la zona de difusion formada entre el circonio y el aluminiopuros, y el mecanismo de difusion se interpreta en terminos de la estructura del reticulado compuesto. Los resultados indican que el ZrAl{sub 3} forma un reticulado con defectos, lo que conduce a la migracion relativamente rapida de los atomos de aluminio. (author) [Russian] Izmerenie podvizhnosti atomov v tverdyh telah chasto predstavljaet neposredst- vennyj interes dlja lic, zanimajushhihsja konstruirovaniem, razrabotkoj i ispol'zovaniem materialov v tehnike. Odnako v nastojashhee vremja vse bol'shee vnimanie udeljaetsja izucheniju takih svojstv s uchetom nalichija i haraktera tochechnyh i linejnyh defektov v kristallah. Rassmatrivajutsja nekotorye poslednie issledovanija diffuzii, provedennye v Jadernyh labora- torijah Chok-River, kotorye ne tol'ko dajut dannye, predstavljajushhie interes dlja jader- noj tehnologii, no i pozvoljajut bolee fundamental'no ponjat' harakter defektov reshetok, vstrechajushhihsja v materialah. Rassmatrivaemymi sistemami javljajutsja: 1) samodiffuzija v vysokotemperaturnoj faze chistogo cirkonija; 2) diffuzija rastvorennogo veshhestva v svin- ce i 3) vzaimnaja diffuzija aljuminija i cirkonija. Kratko rassmatrivajutsja neobychnye i v nastojashhee vremja ne polnost'ju ponjatye rezul'taty, soderzhashhiesja v punkte 1). Privodjatsja dannye, kotorye dajut osnovanie predpolagat', chto diffuzija proishodit ili cherez plot- nuju sistemu dislokacii, obrazovavshujusja v rezul'tate transformacii martensitovoj fazy, ili cherez izbytochnye vakansii v kristalle, svjazannye s primesjami. Vo vtorom punk- te budet obsuzhdat'sja vopros o chrezvychajno bystroj diffuzii rastvorennyh blagorodnyh metallov v monokristallah svinca vysokoj chistoty s tochki zrenija sostojanija atomov rastvo- rennogo veshhestva. Pokazano, chto ih diffuzionnoe povedenie mozhet byt' ponjato, esli predpolozhit', chto frakcija f{sub i} atomov rastvorennogo veshhestva zanimaet mezhdouzlija. Izmerennyj kojefficient diffuzii Ot s v jazans kojefficientom mezhdouzlovoj diffuzii otno- sheniem D{sub m} = fiDi. V punkte 3) opisyvaetsja obrazovanie i bystryj rost edinichnogo mezh- metallicheskogo soedinenija ZrAl{sub 3} v zone diffuzii, obrazovavshejsja mezhdu chistym cirko- niem i chistym aljuminiem, i mehanizm diffuzii ob{sup j}asnjaetsja ishodja iz struktury reshet- ki soedinenija. Rezul'taty pokazyvajut, chto ZrAl{sub 3} obrazuet defektnuju reshetku, kotoraja privodit k otnositel'no bystroj migracii atomov aljuminija. (author)

Posterior urethral valves: Morphological normalization of posterior urethra after fulguration is a significant factor in prognosis.

Science.gov (United States)

Menon, Prema; Rao, K L N; Vijaymahantesh, S; Kanojia, R P; Samujh, R; Batra, Y K; Sodhi, K S; Saxena, A K; Bhattacharya, A; Mittal, B R

2010-07-01

To assess the changes in urethral morphology 3 months post fulguration of posterior urethral valves (PUVs) on micturating cystourethrogram (MCUG) and correlate these changes with the overall clinical status of the patient. A total of 217 children, managed for PUVs during a period of 6 years in a single surgical unit were prospectively studied. The ratio of the diameters of the prostatic and bulbar urethras (PU/BU) was calculated on the pre- and post-fulguration MCUG films. They were categorized into three groups based on the degree of normalization of posterior urethra (post-fulguration PU/BU ratio). Of the 133 patients, 131 had normal urinary stream and 4 (3%) had nocturnal enuresis. Vesicoureteral reflux (VUR), initially seen in 83 units (31% units), regressed completely at a mean duration of 6 months in 41 units (49%). Of the 152 non-VUR, hydroureteronephrosis (HUN) units, 11 were poorly functioning kidneys. Persistent slow but unobstructed drainage was seen in 23 units (16%) over a period of 1.5-5 years (mean 2.5 years). Group B: All the 11 patients had a normal stream. Four (36.4%) had daytime frequency for a mean duration of 1 year and one (9%) had nocturnal enuresis for 1 year. Grade IV-V VUR was seen in five patients (three bilateral), which regressed completely by 3 months in five units (62.5%). In the non-VUR, HUN patients, slow (but unobstructed) drainage was persistent in two units (14%) at 3 years. Group C: Of the 16 patients, only 5 (31.3%) were asymptomatic. Six patients (nine units) had persistent VUR for 6 months to 3 years. Of the 20 units with HUN, 17 (85%) were persistent at 1-4 years (mean 2 years). Eight patients (50%) required a second fulguration while 3 (18.7%) required urethral dilatation for stricture following which all parameters improved. Adequacy of fulguration should be assessed by a properly performed MCUG. A postop PU/BU ratio >3 SD (1.92) should alert to an incomplete fulguration or stricture. Patients within normal range ratio

Detection, fate and inactivation of pathogenic norovirus employing settlement and UV treatment in wastewater treatment facilities

International Nuclear Information System (INIS)

Barrett, M.; Fitzhenry, K.; O'Flaherty, V.; Dore, W.; Keaveney, S.; Cormican, M.; Rowan, N.; Clifford, E.

2016-01-01

It is accepted that discharged wastewaters can be a significant source of pathogenic viruses in receiving water bodies contributing to pollution and may in turn enter the human food chain and pose a risk to human health, thus norovirus (NoV) is often a predominant cause of gastroenteritis globally. Working with NoV poses particular challenges as it cannot be readily identified and detection by molecular methods does not assess infectivity. It has been proposed that the infectivity of NoV may be modelled through the use of an alternative virus; F-specific RNA (FRNA) bacteriophages; GA genotype and other FRNA bacteriophages have been used as a surrogate in studies of NoV inactivation. This study investigated the efficiency of novel pulsed ultraviolet irradiation and low pressure ultraviolet irradiation as a potential pathogen inactivation system for NoV and FRNA bacteriophage (GA) in secondary treated wastewaters. The role of UV dose and the impact of suspended solids concentration on removal efficiency were also examined. The study also investigated the role of settlement processes in wastewater treatment plants in removing NoV. While NoV inactivation could not be determined it was found that at a maximum UV dose of 6.9 J/cm"2 (6900 mJ/cm"2) an average 2.4 log removal of FRNA bacteriophage (GA) was observed; indicating the potential need for high UV doses to remove NoV if FRNA bacteriophage prove a suitable indicator for NoV. The study found that increasing concentrations of suspended solids impacted on PUV efficiency however, it appears the extent of the impact may be site specific. Furthermore, the study found that settlement processes can play a significant role in the removal of FRNA bacteriophage, thus potentially NoV. - Highlights: • Effectiveness of low pressure UV and novel high-intensity pulsed UV disinfection in NoVs removal. • Reduction of FRNA bacteriophage was seen in clarified wastewater after settling. • Adsorption of viral particles to solids

Detection, fate and inactivation of pathogenic norovirus employing settlement and UV treatment in wastewater treatment facilities

Energy Technology Data Exchange (ETDEWEB)

Barrett, M. [Microbial Ecology Laboratory, Microbiology, School of Natural sciences, National University of Ireland Galway (Ireland); Ryan Institute, National University of Ireland Galway (Ireland); College of Engineering and Informatics, National University of Ireland Galway (Ireland); Fitzhenry, K. [Ryan Institute, National University of Ireland Galway (Ireland); College of Engineering and Informatics, National University of Ireland Galway (Ireland); O' Flaherty, V. [Microbial Ecology Laboratory, Microbiology, School of Natural sciences, National University of Ireland Galway (Ireland); Ryan Institute, National University of Ireland Galway (Ireland); Dore, W.; Keaveney, S. [Marine Institute, Galway (Ireland); Cormican, M. [Ryan Institute, National University of Ireland Galway (Ireland); Centre for Health from Environment, Ryan Institute, National University of Ireland Galway (Ireland); Rowan, N. [Bioscience Research Institute, Athlone Institute of Technology (Ireland); Clifford, E., E-mail: eoghan.clifford@nuigalway.ie [Ryan Institute, National University of Ireland Galway (Ireland); College of Engineering and Informatics, National University of Ireland Galway (Ireland)

2016-10-15

It is accepted that discharged wastewaters can be a significant source of pathogenic viruses in receiving water bodies contributing to pollution and may in turn enter the human food chain and pose a risk to human health, thus norovirus (NoV) is often a predominant cause of gastroenteritis globally. Working with NoV poses particular challenges as it cannot be readily identified and detection by molecular methods does not assess infectivity. It has been proposed that the infectivity of NoV may be modelled through the use of an alternative virus; F-specific RNA (FRNA) bacteriophages; GA genotype and other FRNA bacteriophages have been used as a surrogate in studies of NoV inactivation. This study investigated the efficiency of novel pulsed ultraviolet irradiation and low pressure ultraviolet irradiation as a potential pathogen inactivation system for NoV and FRNA bacteriophage (GA) in secondary treated wastewaters. The role of UV dose and the impact of suspended solids concentration on removal efficiency were also examined. The study also investigated the role of settlement processes in wastewater treatment plants in removing NoV. While NoV inactivation could not be determined it was found that at a maximum UV dose of 6.9 J/cm{sup 2} (6900 mJ/cm{sup 2}) an average 2.4 log removal of FRNA bacteriophage (GA) was observed; indicating the potential need for high UV doses to remove NoV if FRNA bacteriophage prove a suitable indicator for NoV. The study found that increasing concentrations of suspended solids impacted on PUV efficiency however, it appears the extent of the impact may be site specific. Furthermore, the study found that settlement processes can play a significant role in the removal of FRNA bacteriophage, thus potentially NoV. - Highlights: • Effectiveness of low pressure UV and novel high-intensity pulsed UV disinfection in NoVs removal. • Reduction of FRNA bacteriophage was seen in clarified wastewater after settling. • Adsorption of viral particles

The Problems of Controlling Defects in the Materials Used for the First Czechoslovak Nuclear-Power Station; Problemes de Controle des Defauts dans les Materiaux Utilises a la Premiere Centrale Nucleaire de Tchecoslovaquie; Problemy defektoskopicheskogo kontrolya stroitel'nykh materialov reaktora pervoj chekhoslovatskoj atomnoj ehlektrostantsii; Problemas de Control de Defectos en los Materiales Utilizados en la Primera Central Nuclear de Checoslovaquia

Energy Technology Data Exchange (ETDEWEB)

Radislav, Filipp [Zavody Im.V.I. Lenina, Pl' zen, Czechoslovakia (Czech Republic)

1965-09-15

. Igualmente, se compensa el efecto de la irregularidad del acoplamiento acustico; el dispositivo envia impulsos al dispositivo del registro a distancia. Las dimensiones del defecto se determinan con ayuda de un atenuador. En la actualidad, se esta montando una instalacion automatica que permitira proceder al control de la superficie de un cilindro vertical. En el caso de las soldaduras, es necesario efectuar el control en la parte exterior a temperatura elevada. Con esa finalidad, en la fabrica 'V.I. Lenin' d e Pilsen se ha construido un dispositivo especial que permite procecer a controles de gran exactitud a altas temperaturas. El control no destructivo de los elementos soldados se efectua igualmente por rayos X. La medicion de pequenosi espesores y del metal base de una soldadura se hace mediante rayos X caracteristicos, utilizando chasis especiales. En la radioscopia de piezas soldadas de gran espesor se recurre a un betatron de procedencia checoslovaca. En la memoria se describe la tecnica de los ensayos, los resultados obtenidos y se comparan las caracteristicas del mencionado betatron de 15 MeV con otro construido por la firma Siemens. (author) [Russian] Daetsja kratkoe opisanie korpusa reaktora pervoj chehoslovackoj atomnoj jelektrostancii. Vysokie tre- bovanija k konstrukcii i tehnologii izgotovlenija korpusa reaktora, vypolnennogo iz nizko- legirovannoj nestarejushhej stali (tolshhina stenok 650 mm), priveli k neobhodimosti razra- botki metoda 'svidetelej' dlja kontrolja prochnosti konstrukcii bez razrushenija osnovnogo materiala i svarnyh soedinenij. Dlja kontrolja kachestva osnovnogo materiala i svarnyh soedinenij v bol'shoj mere is- pol'zuetsja ul'trazvukovoj impul'snyj metod s primeneniem odnogo zonda. Daetsja opisanie metodiki ispytanij i ocenki pokazanij vo vremja issledovanija osnovnogo materiala, a takzhe metodiki ispytanija kachestva jelektroshlakovyh svarnyh soedinenij, svarnyh soedinenij, provedennyh v atmosfere uglekislogo gaza , i ruchnyh dugovyh

UV irradiation improves the bond strength of resin cement to fiber posts.

Science.gov (United States)

Zhong, Bo; Zhang, Yong; Zhou, Jianfeng; Chen, Li; Li, Deli; Tan, Jianguo

2011-01-01

The purpose is to evaluate the effect of UV irradiation on the bond strength between epoxy-based glass fiber posts and resin cement. Twelve epoxy-based glass fiber posts were randomly divided into three groups. Group 1 (Cont.): No surface treatment. Group 2 (Low-UV): UV irradiation was conducted from a distance of 10 cm for 10 min. Group 3 (High-UV): UV irradiation was conducted from a distance of 1 cm for 3 min. A resin cement (CLEARFIL SA LUTING) was used for the post cementation to form resin slabs which contained fiber posts in the center. Microtensile bond strengths were tested and the mean bond strengths (MPa) were 18.81 for Cont. group, 23.65 for Low-UV group, 34.75 for High-UV group. UV irradiation had a significant effect on the bond strength (pUV irradiation demonstrates its capability to improve the bond strength between epoxy-based glass fiber posts and resin cement.

Association of actinides with microorganisms and clay: Implications for radionuclide migration from waste-repository sites

International Nuclear Information System (INIS)

Ohnuki, T.; Francis, A.; Kozai, N.; Sakamoto, F.; Ozaki, T.; Nankawa, T.; Suzuki, Y.

2010-01-01

We conducted a series of basic studies on the microbial accumulation of actinides to elucidate their migration behavior around backfill materials used in the geological disposal of radioactive wastes. We explored the interactions of U(VI) and Pu(VI) with Bacillus subtilis, kaolinite clay, and within a mixture of the two, directly analyzing their association with the bacterium in the mixture by transmission electron microscopy (TEM) and scanning electron microscopy (SEM). The accumulation of U by the mixture rose as the numbers of B. subtilis cells increased. Treating the kaolinite with potassium acetate (CH 3 COOK) removed approximately 80% of the associated uranium while only 65% was removed in the presence of B. subtilis. TEM-EDS analysis confirmed that most of the U taken from solution was associated with B. subtilis. XANES analyses revealed that the oxidation state of uranium associated with B. subtilis, kaolinite, and with the mixture containing both was U(VI). The amount of Pu sorbed by B. subtilis increased with time, but did not reach equilibrium in 48 h; in kaolinite alone, equilibrium was attained within 8 h. After 48 h, the oxidation state of Pu in the solutions exposed to B. subtilis and to the mixture had changed to Pu(V), whereas the oxidation state of the Pu associated with both was Pu(IV). In contrast, there was no change in the oxidation state of Pu in the solution nor on kaolinite after exposure to Pu(VI). SEM-EDS analysis indicated that most of the Pu in the mixture was associated with the bacteria. These results suggest that U(VI) and Pu(VI) preferentially are sorbed to bacterial cells in the presence of kaolinite clay, and that the mechanism of accumulation of U and Pu differs. U(VI) is sorbed directly to the bacterial cells, whereas Pu(VI) first is reduced to Pu(V) and then to Pu(IV), and the latter is associated with the cells. These results have important implications on the migrations of radionuclides around the repository sites of

Posterior urethral valves: Morphological normalization of posterior urethra after fulguration is a significant factor in prognosis

Directory of Open Access Journals (Sweden)

Menon Prema

2010-01-01

Full Text Available Aim: To assess the changes in urethral morphology 3 months post fulguration of posterior urethral valves (PUVs on micturating cystourethrogram (MCUG and correlate these changes with the overall clinical status of the patient. Materials and Methods: A total of 217 children, managed for PUVs during a period of 6 years in a single surgical unit were prospectively studied. The ratio of the diameters of the prostatic and bulbar urethras (PU/BU was calculated on the pre- and post-fulguration MCUG films. They were categorized into three groups based on the degree of normalization of posterior urethra (post-fulguration PU/BU ratio. Results: Group A: Of the 133 patients, 131 had normal urinary stream and 4 (3% had nocturnal enuresis. Vesicoureteral reflux (VUR, initially seen in 83 units (31% units, regressed completely at a mean duration of 6 months in 41 units (49%. Of the 152 non-VUR, hydroureteronephrosis (HUN units, 11 were poorly functioning kidneys. Persistent slow but unobstructed drainage was seen in 23 units (16% over a period of 1.5-5 years (mean 2.5 years. Group B: All the 11 patients had a normal stream. Four (36.4% had daytime frequency for a mean duration of 1 year and one (9% had nocturnal enuresis for 1 year. Grade IV-V VUR was seen in five patients (three bilateral, which regressed completely by 3 months in five units (62.5%. In the non-VUR, HUN patients, slow (but unobstructed drainage was persistent in two units (14% at 3 years. Group C: Of the 16 patients, only 5 (31.3% were asymptomatic. Six patients (nine units had persistent VUR for 6 months to 3 years. Of the 20 units with HUN, 17 (85% were persistent at 1-4 years (mean 2 years. Eight patients (50% required a second fulguration while 3 (18.7% required urethral dilatation for stricture following which all parameters improved. Conclusions: Adequacy of fulguration should be assessed by a properly performed MCUG. A postop PU/BU ratio >3 SD (1.92 should alert to an incomplete

Plutonium speciation affected by environmental bacteria

International Nuclear Information System (INIS)

Neu, M.P.; Icopini, G.A.; Boukhalfa, H.

2005-01-01

Plutonium has no known biological utility, yet it has the potential to interact with bacterial cellular and extracellular structures that contain metal-binding groups, to interfere with the uptake and utilization of essential elements, and to alter cell metabolism. These interactions can transform plutonium from its most common forms, solid, mineral-adsorbed, or colloidal Pu(IV), to a variety of biogeochemical species that have much different physico-chemical properties. Organic acids that are extruded products of cell metabolism can solubilize plutonium and then enhance its environmental mobility, or in some cases facilitate plutonium transfer into cells. Phosphate- and carboxylate-rich polymers associated with cell walls can bind plutonium to form mobile biocolloids or Pu-laden biofilm/mineral solids. Bacterial membranes, proteins or redox agents can produce strongly reducing electrochemical zones and generate molecular Pu(III/IV) species or oxide particles. Alternatively, they can oxidize plutonium to form soluble Pu(V) or Pu(VI) complexes. This paper reviews research on plutonium-bacteria interactions and closely related studies on the biotransformation of uranium and other metals. (orig.)

Mechanism of the rapid dissolution of Pu02 under oxidizing conditions and applications

International Nuclear Information System (INIS)

Madic, C.; Lecomte, M.; Bourges, J.; Koehly, G.

1991-01-01

Until the recent years, plutonium dioxide was known to be among the metallic oxides the most difficult to dissolve. From thermodynamic calculations it can be predicted that PuO 2 will dissolve under oxidizing conditions. This can be achieved using Ag(II) species possibly regenerated by electrochemical means. The mechanism of such a process has been elucidated using carbon paste electrochemistry and 18 O labelling. These studies demonstrate that the chemical reaction limiting the overall proces is located on the surface of the solid PuO 2 , and that the first step consists in the oxidation of the plutonium into Pu(V) species. Applications of the dissolution process of PuO 2 by electrogenerated Ag(II) were growing in the recent years in FRANCE. These applications developed often in collaboration with SGN and COGEMA, concern the treatment of: out of specifications PuO 2 , incineration ashes, wastes produced during MOX fuel fabrication, and during the dismantling of old nuclear facilities. A general overview of these different applications is given

Urinary tract infection after retrograde urethrogram in children: A multicenter study.

Science.gov (United States)

Malhotra, Neha R; Green, Jared R; Rigsby, Cynthia K; Holl, Jane L; Cheng, Earl Y; Johnson, Emilie K

2017-12-01

The risk of post-procedural urinary tract infection (ppUTI) after retrograde urethrogram (RUG) has not been well quantified. Prophylactic antibiotics may reduce the risk, but must be weighed against the risks of antibiotic resistance. Prior research has shown that this risk is variable after voiding cystourethrogram (0-42% reported ppUTI rate) and appears to be low after urodynamics (0-4.8%) but this risk has not been well documented for patients undergoing RUG. We aimed to (1) describe the rate of ppUTI after RUG, and (2) examine factors associated with use of antibiotics at the time of RUG. We conducted a retrospective cohort study of children undergoing RUG at two hospitals January 1, 2004, to December 31, 2014. ppUTI within 7 days was measured. Antibiotic prophylaxis was determined. Relationships between clinical characteristics and receipt of pre-procedure antibiotics were evaluated using univariate statistics. Forty-two patients (100% male, median age 11.7 years) underwent 47 RUGs. Indications included trauma (27%), hypospadias (17%), and non-hypospadias (27%) stricture. Study indication and antibiotic administration practices are illustrated in the Figure. Three patients (6.4%) had a history of posterior urethral valves (PUV); one had neurogenic bladder (NGB) (2.4%). Two (4%) studies were performed within 30 days of a clinical UTI and 11% had a positive urinalysis or culture within 30 days pre-RUG. UTI in the 30 days before RUG was not associated with antibiotic prescription (p > 0.99). One child (2.1%; 95% CI 0-6.3%) had a ppUTI: a 7-year-old, uncircumcised male with a history of PUV and voiding dysfunction who was asymptomatic at the time of RUG. Although the risk of ppUTI after RUG appears to be low, the rare occurrence of an iatrogenic UTI can lead to high cost and patient morbidity, particularly in cases similar to our patients who required inpatient admission for intravenous antibiotics. To help balance the risk of UTI with the associated healthcare

Actinide speciation bound to hydrous ferric oxide colloids in the near-field conditions of the waste pond at 'Mayak' facility (Russia)

International Nuclear Information System (INIS)

Kalmykov, St.; Khasanova, A.; Kriventsov, V.; Teterin, Y.; Novikov, A.

2007-01-01

Full text of publication follows: 'Mayak' facility is a nuclear waste and spent nuclear fuel reprocessing plant located in Ural Mountains, Russia. The opened pond, Karachay Lake, was used for several decades for the discharge of low- and intermediate level waste solutions containing fission products and traces of actinides. Due to high salt concentration and high density of waste solutions, they are penetrating into the groundwater system that is represented by oxic Eh conditions. The speciation of actinides in groundwater samples collected close to Karachay Lake was studied by successive micro- and ultra-filtrations with subsequent SEM, TEM, nano-SIMS, membrane extraction and other techniques. It was established that U and Np were found in soluble fraction (pass through 10 kD ultra-filter) in the form of their bi- and tri-carbonate complexes that was supported by chemical thermodynamic calculations. In contrast, Pu and Am were bound to nano-colloids 10 kD - 50 nm in size. The SEM and TEM data indicate the presence of variety of different colloidal particles which relative concentration decrease in the row: hydrous ferric oxides (HFO) >> clays ≅ calcite > rutile ≅ hematite ≅ barite ≅ MnO 2 > monazite > other phases. The SIMS with submicron resolution (Cameca nanoSIMS-50) was used to study local concentration of actinides. According to the obtained data among different colloids detected in the sample actinides were preferentially bound to HFO and MnO 2 while other phases did not sorb actinides. In order to determine actinide speciation bound to HFO colloids XPS and An L 3 edge XAFS measurements were done at Siberian Synchrotron Radiation Centre. The storage ring VEPP-3 with electron beam energy of 2 GeV and an average stored current of 80 mA was used as the source of radiation. Since the concentration of actinides in actual samples was too low for XAFS, the samples for measurements were prepared by contacting about 10 -5 M solutions of Np(V) and Pu(V) with

Stabilization of actinides and lanthanides in unusually high oxidation states

International Nuclear Information System (INIS)

Eller, P.G.; Penneman, R.A.

1986-01-01

Chemical environments can be chosen which stabilize actinides and lanthanides in unusually high or low oxidation states and in unusual coordination. In many cases, one can rationalize the observed species as resulting from strong charge/size influences provided by specific sites in host lattices (e.g., Tb(IV) in BaTbO 3 or Am(IV) in polytungstate anions). In other cases, the unusual species can be considered from an acid-base viewpoint (e.g., U(III) in AsF 5 /HF solution or Pu(VII) in Li 5 PuO 6 ). In still other cases, an interplay of steric and redox effects can lead to interesting comparisons (e.g., instability of double fluoride salts of Pu(V) and Pu(VI) relative to U, Np, and Am analogues). Generalized ways to rationalize compounds containing actinides and lanthanides in unusual valences (particularly high valences), including the above and numerous other examples, will form the focus of this paper. Recently developed methods for synthesizing high valent f-element fluorides using superoxidizers and superacids at low temperatures will also be described. 65 refs., 8 figs., 9 tabs

Mass spectrometric studies of the complexing behaviour of actinide ions in solution

International Nuclear Information System (INIS)

Steppert, Michael

2012-01-01

As the long-term radiotoxicity of spent nuclear fuel is governed by Plutonium and the Minor Actinides, these elements are focussed on for investigations in the framework of safety assessment for nuclear waste repositories. To shed more light on the selectivity of the partitioning ligands BTP and BTBP towards the extraction of trivalent actinides, the complexes these ligands form with lanthanides in octanolic solution were characterized. The differences in the extraction efficiencies among the different lanthanides were traced back to the varying preferential formation of Ln(BTP)3 complexes, depending on the ionic radius of the lanthanides. Additionally it was shown that depending on the sterical demand of BTBP ligands nitrate anions coordinate in the first coordination shell of Eu(BTBP)2-complexes. As the behavior of Plutonium under geochemical conditions is of particular interest for the safety assessment of potential nuclear waste repositories, the second part of the thesis focuses on the hydrolysis and colloid formation behavior of aqueous Plutonium solutions. The solution species of Zirconium(IV) as analogue for Plutonium(IV) as well as of Uranium(VI) and Plutonium(VI) were characterized and quantified by means of electrospray ionization mass spectrometry. Moreover the colloid-induced reduction of Pu(V) to Pu(IV) and the subsequent formation of colloidal species was investigated. [de

Plutonium - its behavior in natural-water systems and assimilation by man

International Nuclear Information System (INIS)

Larsen, R.P.; Nelson, D.M.; Bhattacharyya, M.H.; Oldham, R.D.

1981-01-01

There are a number of factors which must be considered in establishing whether or not the inadvertent intrusion of a sizable amount of plutonium-bearing material into a natural-water system may have a significant impact on the health of those individuals who use that system as a drinking-water resource. These factors include the chemical form(s) and solubility of plutonium in natural waters, its behavior in relation to natural processes (geochemical and biological), its fate in water-treatment systems, and its uptake by man from drinking water. From the results obtained of the behavior in natural-water systems, it appears that (1) the chemical forms of plutonium dissolved in natural waters are Pu(IV) and Pu(V), (2) the soluble plutonium in many waters is bound to the organic constituents which probably enhance plutonium solubility, (3) the natural process responsible for the removal of plutonium from water is adsorption onto sediments, and (4) in water-treatment systems, soluble plutonium is oxidized to the VI state and this form is not removed. From investigations of gastrointestinal absorption, it appears that the value for f 1 , the fraction transferred from the gut to blood, is greater than 1 x 10 - 3 and may be as high as 2 x 10 - 1

Stability of rare earth complexes with 2-(o-hydroxyphenyl)benzimidazole in aqueous-dioxane medium. Ustojchivost' kompleksnykh soedinenij RZEh s 2-(o-oksifenil)benzimidazolom v vodno-dioksanovoj srede

Energy Technology Data Exchange (ETDEWEB)

Akhrimenko, Z M; Panyushkin, V T; Fedorova, M V [Kubanskij Gosudarstvennyj Univ., Krasnodar (USSR)

1990-01-01

Method of potentiometric titration was used to determine protonation constants of 2-(-hydroxyphenyl)benzimidazole (pK{sub 1}=4.5; pK{sub 2}=11.30) and stability constants of Pr,Nd,Sm,Eu,Tb,Dy complexes with this ligand. Nonmonotonous change of lgK{sub 1} with increase of ordinal number of rare earth element was revealed.

Method of obtaining concentrated preparations of Cl{sup 36} and Br{sup 82} by recoil nuclei under exposure to high-density neutron fields; Preparation de composes du chlore-36 et du brome-82 de haute activite specifique, par exposition de noyaux de recul a des champs neutroniques intenses; Poluchenie kontsentrirovannykh preparatov Cl{sup 36} i Br{sup 82} metodom yader otdachi pri obluchenii v nejtronnykh polyakh vysokoj plotnosti; Obtencion de compuestos de cloro-36 y de bromo-82 de alta actividad especifica por retroceso de nucleos en campos neutronicos intensos

Energy Technology Data Exchange (ETDEWEB)

Kurchatova, L N; Kurchatov, B V

1962-01-15

resultado de la superposicion de toda una serie de procesos : formacion de atomos de cloro radiactivo, separacion radiolitica del haluro, difusion de los productos obtenidos en la red cristalina del carbono, su sorcion en la superficie y su recombinacion en distintos centros. La extraordinaria variedad de condiciones en que se forman e interaccionan los productos de irradiacion con el esqueleto carbonico y su superficie depende de un gran numero de factores, a saber : la estructura ultramicroscopica, la naturaleza de los nuevos compuestos, que estan relacionados con el tipo de compuestos superficiales, la existencia en la superficie del carbono de centros con un espectro continuo de energia de sorcion, la probable formacion de diversos centros estacionarios de recombinacion por irradiacion del carbono, etc. Por ello, las tecnicas utilizadas ofrecen la posibilidad de realizar una gran variedad de experimentos a fin de establecer las condiciones optimas de enriquecimiento. (author) [Russian] Klassicheskij metod polucheniya kontsentrirovannykh radioaktivnykh preparatov Stsilarda-CHalmersa obychno rassmatrivaetsya kak malo ehffektivnyj pri ispol'zovanii bol'shikh integral'nykh potokov nejtronov iz-za znachitel'nogo razlozheniya obluchaemogo soedineniya pod dejstviem radiatsii. Avtorami najdeny soedineniya broma i khlora s uglerodom, pozvolyayushchie poluchat' sushchestvennoe obogashchenie radioaktivnymi izotopami khlora i broma metodom yader otdachi pri obluchenii v nejtronnykh potokakh poryadka 10{sup 13} nejtr./sek-cm{sup 2}. EHti soedineniya otvechayut formule C{sub n}X, gde X-Cl ili Br, N = 10 + 20 dlya soedineniya khlora i 25 + 70 -dlya soedinenij broma. Oni dostatochno ustojchivy termicheski i khimicheski. Soedinenie sostava C{sub 30}Br vyderzhivaet nagrevanie do 300{sup o}C v atmosfere argona bez otshchepleniya broma; ono razlagaetsya polnost'yu pri temperature 600{sup o}C. Ukazannoe soedinenie broma s uglerodom prakticheski ustojchivo k vozdejstviyu vodnykh rastvorov

Cleaning up the legacy of the cold war: plutonium oxides and the role of synchrotron radiation research

International Nuclear Information System (INIS)

Clark, David L.

2015-01-01

This presentation will cover three aspects of Los Alamos synchrotron radiation studies of plutonium oxides: (1) the use of UHV X-ray spectroscopy techniques to gain insights into the electronic structure of the actinide dioxides; (2) the results and interpretation Pu X-ray Absorption Fine Structure (XAFS) spectra of 24 samples of PuO 2+x ; and (3) the application of synchrotron radiation towards the decontamination and decommissioning of the Rocky Flats Environmental Technology Site (RFETS, the former nuclear weapons production site for the US). I will summarize a multidisciplinary effort to characterize the electronic structure and bonding of stoichiometric AnO 2 (U, Pu) using our screened hybrid DFT calculations for comparison with photoemission spectroscopy (PES) to measure the experimental density of states (DOS), and with oxygen K-edge X-ray absorption spectroscopy (XAS) to map the O 2p character in the unoccupied DOS. I will also describe the structural chemistry of laboratory prepared AnO 2+x systems (An = U, Pu; 0 ≤ x ≤ 0.25) using a combination of X-ray absorption fine structure spectroscopy (XAFS) and X-ray and neutron scattering of laboratory prepared samples. All data are consistent with mixed-valent solids where plutonium exists as a mixture of Pu(IV) and Pu(V) oxidation states, and uranium exists as a mixture of U(IV) and U(VI)

Influence of dissolved organic carbon on the sorption of plutonium to natural sediments

International Nuclear Information System (INIS)

Nelson, D.M.; Karttunen, J.O.; Orlandini, K.A.; Larsen, R.P.

1981-01-01

One prominent aspect of the environmental behavior of plutonium is a tendency for strong, though not complete, association with soil and sediments. The nature of this association is not well understood, and the water quality parameters which may affect it have not been identified. It is assumed that adsorption is dependent upon the chemical species present (oxidation state and complex ion associations) and that the uncomplexed form of Pu(IV) is the one that is most highly sorbed. In certain oligotrophic waters the dissolved plutonium is primarily in the oxidized form (presumably as Pu(V)), a form that is weakly sorbed. This could account for its solubility. In all water, however, some of the dissolved plutonium is present in the reduced form (presumably as Pu(IV)). The apparent solubility of this reduced form, as measured by a sediment concentration factor, varies markedly among the lakes. The concentrations of dissolved organic carbon (DOC) have now been measured in the waters from a number of lakes and a general dependence of the sediment concentration factor (K/sub D/) for Pu(IV) upon DOC has become evident. In order to study the nature of this plutonium-organic complex in more detail several experiments were conducted in which the sediment concentration factor was measured as a function of DOC concentration

Plutonium(VI) accumulation and reduction by lichen biomass: correlation with U(VI)

International Nuclear Information System (INIS)

Ohnuki, Toshihiko; Aoyagi, Hisao; Kitatsuji, Yoshihiro; Samadfam, Mohammad; Kimura, Yasuhiko; William Purvis, O.

2004-01-01

The uptake of plutonium(VI) and uranium(VI) by lichen biomass was studied in the foliose lichen Parmotrema tinctorum to elucidate the migration behavior of Pu and U in the terrestrial environment. Pu and U uptake by P. tinctorum averaged 0.040±0.010 and 0.055±0.015 g g dry -1 , respectively, after 96 h incubation with 4.0x10 -4 mol l -1 Pu solutions of pH 3, 4 and 5. SEM observations showed that the accumulated Pu is evenly distributed on the upper and lower surfaces of P. tinctorum, in contrast to U(VI), which accumulated in both cortical and medullary layers. UV/VIS absorption spectroscopy demonstrates that a fraction of Pu(VI) in the solution is reduced to Pu(V) by the organic substances released from P. tinctorum, and the accumulated Pu on the surface is reduced to Pu(IV), while U(VI) keeps the oxidation state of VI. Since the solubility of Pu(IV) hydroxides is very low, reduced Pu(VI) does not penetrate to the medullary layers, but is probably precipitated as Pu(IV) hydroxides on the cortical lichen surface. It is concluded that the uptake and reduction of Pu(VI) by lichens is important to determine the mobilization and oxidation states of Pu in the terrestrial environment

Research Program to Determine Redox Reactions and Their Effects on Speciation and Mobility of Plutonium in DOE Wastes

International Nuclear Information System (INIS)

Choppin, G.R.; Rai, D.

2000-01-01

Plutonium in geologic matrices undergoes a variety of complex reactions which complicate its environmental behavior. These complexities in plutonium chemistry whereby a large variety of precipitation, dissolution, adsorption/desorption, and redox reactions control plutonium speciation and concentrations, result in the need for a rather large amount of reliable, fundamental data to predict Pu behavior in geologic media. These data are also needed for evaluation of remediation strategies that involve removing most of the contaminants by selective methods, followed by in situ immobilization of residual contaminants. Two areas were studied during this project: (1) thermodynamic data for Th(IV) and Pu(IV) complexes of EDTA and for Pu(V) interactions with chloride; (2) kinetic data for redox reactions of Pu in the presence of common redox agents (e.g., H 2 O 2 , MnO 2 , and NaOCl) encountered under waste disposal conditions. These studies are relevant to understanding Pu behavior in wastes disposed of in diverse geologic conditions (e.g., at the WIPP and YUCCA Mountain repositories and in contaminated sediments at many different DOE sites) and also for developing effective remediation strategies (e.g., processing of high level waste tanks). These studies have yielded data to address redox reactions of plutonium in the presence of environmentally important agents (e.g. organic and inorganic oxidants/reductants)

Lower urinary tract development and disease

Science.gov (United States)

Rasouly, Hila Milo; Lu, Weining

2013-01-01

Congenital Anomalies of the Lower Urinary Tract (CALUT) are a family of birth defects of the ureter, the bladder and the urethra. CALUT includes ureteral anomalies such as congenital abnormalities of the ureteropelvic junction (UPJ) and ureterovesical junction (UVJ), and birth defects of the bladder and the urethra such as bladder-exstrophy-epispadias complex (BEEC), prune belly syndrome (PBS), and posterior urethral valves (PUV). CALUT is one of the most common birth defects and is often associated with antenatal hydronephrosis, vesicoureteral reflux (VUR), urinary tract obstruction, urinary tract infections (UTI), chronic kidney disease and renal failure in children. Here, we discuss the current genetic and molecular knowledge about lower urinary tract development and genetic basis of CALUT in both human and mouse models. We provide an overview of the developmental processes leading to the formation of the ureter, bladder, and urethra, and different genes and signaling pathways controlling these developmental processes. Human genetic disorders that affect the ureter, bladder and urethra and associated gene mutations are also presented. As we are entering the post-genomic era of personalized medicine, information in this article may provide useful interpretation for the genetic and genomic test results collected from patients with lower urinary tract birth defects. With evidence-based interpretations, clinicians may provide more effective personalized therapies to patients and genetic counseling for their families. PMID:23408557

Research Program to Determine Redox Reactions and Their Effects on Speciation and Mobility of Plutonium in DOE Wastes

Energy Technology Data Exchange (ETDEWEB)

Choppin, G.R.; Rai, D.

2000-10-01

Plutonium in geologic matrices undergoes a variety of complex reactions which complicate its environmental behavior. These complexities in plutonium chemistry whereby a large variety of precipitation, dissolution, adsorption/desorption, and redox reactions control plutonium speciation and concentrations, result in the need for a rather large amount of reliable, fundamental data to predict Pu behavior in geologic media. These data are also needed for evaluation of remediation strategies that involve removing most of the contaminants by selective methods, followed by in situ immobilization of residual contaminants. Two areas were studied during this project: (1) thermodynamic data for Th(IV) and Pu(IV) complexes of EDTA and for Pu(V) interactions with chloride; (2) kinetic data for redox reactions of Pu in the presence of common redox agents (e.g., H{sub 2}O{sub 2}, MnO{sub 2}, and NaOCl) encountered under waste disposal conditions. These studies are relevant to understanding Pu behavior in wastes disposed of in diverse geologic conditions (e.g., at the WIPP and YUCCA Mountain repositories and in contaminated sediments at many different DOE sites) and also for developing effective remediation strategies (e.g., processing of high level waste tanks). These studies have yielded data to address redox reactions of plutonium in the presence of environmentally important agents (e.g. organic and inorganic oxidants/reductants).

Oxidizing dissolution of spent MOX47 fuel subjected to water radiolysis: Solution chemistry and surface characterization by Raman spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Jegou, C., E-mail: christophe.jegou@cea.f [Commissariat a l' Energie Atomique (CEA), Marcoule Reasearch Center, B.P. 17171, F-30207 Bagnols-sur-Ceze Cedex (France); Caraballo, R.; De Bonfils, J.; Broudic, V.; Peuget, S. [Commissariat a l' Energie Atomique (CEA), Marcoule Reasearch Center, B.P. 17171, F-30207 Bagnols-sur-Ceze Cedex (France); Vercouter, T. [Commissariat a l' Energie Atomique (CEA), Saclay Reasearch Center, B.P. 11, F-91191 Gif-sur-Yvette Cedex (France); Roudil, D. [Commissariat a l' Energie Atomique (CEA), Marcoule Reasearch Center, B.P. 17171, F-30207 Bagnols-sur-Ceze Cedex (France)

2010-04-01

The mechanisms of oxidizing dissolution of spent MOX fuel (MIMAS TU2 (registered) ) subjected to water radiolysis were investigated experimentally by leaching spent MOX47 fuel samples in pure water at 25 deg. C under different oxidizing conditions (with and without external gamma irradiation); the leached surfaces were characterized by Raman spectroscopy. The highly oxidizing conditions resulting from external gamma irradiation significantly increased the concentration of plutonium (Pu(V)) and uranium (U(VI)) compared with a benchmark experiment (without external irradiation). The oxidation behavior of the plutonium-enriched aggregates differed significantly from that of the UO{sub 2} matrix after several months of leaching in water under gamma irradiation. The plutonium in the aggregates appears to limit fuel oxidation. The only secondary phases formed and identified to date by Raman spectroscopy are uranium peroxides that generally precipitate on the surface of the UO{sub 2} grains. Concerning the behavior of plutonium, solution analysis results appear to be compatible with a conventional explanation based on an equilibrium with a Pu(OH){sub 4(am)} phase. The fission product release - considered as a general indicator of matrix alteration - from MOX47 fuel also increases under external gamma irradiation and a change in the leaching mode is observed. Diffusive leaching was clearly identified, coinciding with the rapid onset of steady-state actinide concentrations in the bulk solution.

Development of a Self-Consistent Model of Plutonium Sorption: Quantification of Sorption Enthalpy and Ligand-Promoted Dissolution

Energy Technology Data Exchange (ETDEWEB)

Powell, Brian [Clemson Univ., SC (United States); Kaplan, Daniel I [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Arai, Yuji [Univ. of Illinois, Urbana-Champaign, IL (United States); Becker, Udo [Univ. of Michigan, Ann Arbor, MI (United States); Ewing, Rod [Stanford Univ., CA (United States)

2016-12-29

This university lead SBR project is a collaboration lead by Dr. Brian Powell (Clemson University) with co-principal investigators Dan Kaplan (Savannah River National Laboratory), Yuji Arai (presently at the University of Illinois), Udo Becker (U of Michigan) and Rod Ewing (presently at Stanford University). Hypothesis: The underlying hypothesis of this work is that strong interactions of plutonium with mineral surfaces are due to formation of inner sphere complexes with a limited number of high-energy surface sites, which results in sorption hysteresis where Pu(IV) is the predominant sorbed oxidation state. The energetic favorability of the Pu(IV) surface complex is strongly influenced by positive sorption entropies, which are mechanistically driven by displacement of solvating water molecules from the actinide and mineral surface during sorption. Objectives: The overarching objective of this work is to examine Pu(IV) and Pu(V) sorption to pure metal (oxyhydr)oxide minerals and sediments using variable temperature batch sorption, X-ray absorption spectroscopy, electron microscopy, and quantum-mechanical and empirical-potential calculations. The data will be compiled into a self-consistent surface complexation model. The novelty of this effort lies largely in the manner the information from these measurements and calculations will be combined into a model that will be used to evaluate the thermodynamics of plutonium sorption reactions as well as predict sorption of plutonium to sediments from DOE sites using a component additivity approach.

Influence of Aerosol Properties and the Respiratory Pattern upon Hazards Evaluation following Inhalation Exposure; Influence des Caracteristiques des Aerosols et du Regime de la Respiration sur l'Evaluation des Risques, a la Suite d'une Exposition par Inhalation; Vliyanie svojstv aehrozolej i obraztsa respiratora na otsenku opasnosti oblucheniya pri vdykhanii radioaktivnykh veshchestv; Influencia de las Propriedades de los Aerosoles y de su Esquema Repiratorio en la Evaluacion de los Riesgos Consecutivos a una Exposicion por Inhalacion

Energy Technology Data Exchange (ETDEWEB)

Thomas, R. G. [Lovelace Foundation for Medical Education and Research, Albuquerque, NM (United States)

1964-10-15

diferentes caracteristicas fisicas y quimicas de las particulas inhaladas y las tres variables biologicas antes mencionadas. Se presentan datos acerca de la cantidad y localizacion de la sustancia depositada, determinados en funcion del tamano de las particulas inhaladas, en el caso de un compuesto soluble en los tejidos (cloruro de cesio) y en el caso de un compuesto insoluble en los tejidos (Cloruro de torio). Asimismo, se facilita informacion encaminada a explicar las variaciones que se producen en la distribucion de un elemento en los tejidos y en su excrecion, segun su forma fisicaca y quimica al ser inhalado. Se exponen datos proporcionados por los experimentos realizados con aerosoles de muchas sustancias, entre ellas las ya mencionadas, para poner de manifiesto la peculiar correlacion existente entre la carga corporal y la excrecion por via fecal durante los primeros dias consecutivos a la exposicion. Se demuestra la ventaja de efectuar a la vez analisis de orina y de heces para determinaciones biologicas. Utilizando los anteriores datos como ejemple, se ponen de relieve los errores inherentes a los actuales metodos de evaluacion practica de riesgos, basados en el analisis de muestras de aire y de sustancias biologicas. (author) [Russian] Imeetsja tri vazhnyh biologicheskih parametrov, neobhodimyh dlja ocenki opasnosti v rezul'tate popadanija soedinenij v organizm ljubym putem. K nim otnosjatsja: 1) kolichestvo otlozhivshegosja v organizme veshhestva; 2) raspredelenie i kinetika peremeshhenij v organizme; 3) skorost' vyvedenija veshhestva. Pri sluchajnom obluchenii v celom otsutstvujut dostatochnye kolichestvennye dannye po jetim punktam. V doklade izlagajutsja dannye jeksperimental'nyh issledovanij na zhivotnyh, pokazyvajushhie sootnoshenie mezhdu razlichnymi fizicheskimi i himicheskimi harakteristikami vdyhaemyh chastic i upomjanutymi vyshe tremja biologicheskimi peremennymi. Predstavleny dannye o kolichestve i lokalizacii otlozhivshegosja materiala kak funkcii

Speciation of the plutonium at trace levels by capillary electrophoresis-ICP-MS coupling

International Nuclear Information System (INIS)

Ambard, Ch.

2007-01-01

The CE-ICP-MS coupling allowed the development of new analytical methods for the study of plutonium speciation at trace levels including complexation studies of this element by organic and inorganic ligands. First, a method, called dual detection, based on the simultaneous use of the UV-Visible spectrophotometer integrated in the capillary electrophoresis and the ICPMS was developed and validated. It allows the unambiguous determination of electrophoretic mobilities for separated chemical species and gives a powerful tool for speciation studies. Then, the influence on plutonium redox speciation of the buffer from the background electrolyte was evaluated. This study showed the implications of the electrolyte constituents' choice on plutonium redox equilibrium in the sample. Furthermore, the CE-ICP-MS coupling was used for studying the plutonium complexation at trace levels by some organic (NTA and DTPA) and inorganic ligands (carbonates). The behaviour of plutonium valence +III, +IV and +VI was studied in the presence of buffer at near neutral pH. Different species of plutonium were observed depending on the initial oxidation state of the plutonium. This study showed the potential of poly-amino-carboxylic acids, such as NTA and DTPA, for dissolving plutonium precipitates, regardless its initial speciation. Finally, the carbonation of pentavalent neptunium, as an analogue of Pu(V), was achieved at very low concentration of Np (10 -8 mol.L -1 ). The formation constant of NpO 2 (CO 3 )- at 25 deg. C and 2,5 x 10 -2 mol.L -1 ionic strength was measured by CE-ICP-MS and found to be consistent with literature data. (author)

Speciation of the plutonium at trace levels by capillary electrophoresis-ICP-MS coupling

International Nuclear Information System (INIS)

Ambard, Ch.

2007-01-01

The CE-ICP-MS coupling allowed the development of new analytical methods for the study of plutonium (Pu) speciation at trace levels including complexation studies of this element by organic and inorganic ligands. First, a method, called dual detection, based on the simultaneous use of the UV-Visible spectrophotometer integrated in the capillary electrophoresis and the ICP-MS was developed and validated. It allows the unambiguous determination of electrophoretic mobilities for separated chemical species and gives a powerful tool for speciation studies. Then, the influence on Pu redox speciation of the buffer from the background electrolyte was evaluated. This study showed the implications of the electrolyte constituents' choice on Pu redox equilibrium in the sample. Furthermore, the CE-ICP-MS coupling was used for studying the Pu complexation at trace levels by some organic (NTA and DTPA) and inorganic ligands (carbonates). The behaviour of Pu valence +III, +IV and +VI was studied in the presence of buffer at near neutral pH. Different species of Pu were observed depending on the initial oxidation state of the plutonium. The study showed the potential of poly-amino-carboxylic acids, such as NTA and DTPA, for dissolving Pu precipitates, regardless its initial speciation. Finally, the carbonation of pentavalent neptunium, as an analogue of Pu(V), was achieved at very low concentration of Np (10 -8 mol.L -1 ). The formation of NpO 2 (CO 3 ) - at 25 C and 2,5*10 -2 mol.L -1 ionic strength was measured by CE-ICP-MS and found to consistent with literature data. (author)

The Effect of the Ammonium Group on the Different Annealing Processes; Role du Groupe Ammonium dans les Differents Processus de Recuit; 042d 0424 0424 0415 041a 0422 0410 041c 041c 041e 041d 0418 0415 0412 041e 0419 0413 0420 0423 041f 041f 042b 041d 0410 0420 0410 0417 041b 0418 0427 041d 042b 0415 041f 0420 041e 0426 0415 0421 0421 042b 041e 0422 0416 0418 0413 0410 ; Efecto del Grupo Amonio en Diferentes Procesos de Recocido

Energy Technology Data Exchange (ETDEWEB)

Getoff, N. [Institute Of Chemistry, Oesterreichische Studiengesellschaft fuer Atomenergie GmbH, Vienna (Austria)

1965-04-15

certains fragments de recul metastables qui peuvent susciter la formation de substances reductrices, par exemple l'hydrazine. Le rendement en hydrazine augmente quand les echantillons solides exposes aux neutrons sont ulterieurement traites par les rayons gamma, les ultrasons, etc. Une forte variation de la retention se produit en meme temps que croit le rendement en hydrazine. (author) [Spanish] El grupo amonio puede desempenar un papel fundamental en los diferentes procesos de recocido de compuestos amonicos sometidos a irradiacion neutronica. Se han investigado algunas particularidades de este efecto. Con el proposito de dar una vision mas amplia de este tema, se examinan brevemente en primer lugar algunos resultados tipicos, ya publicados, referentes al recocido termico, por irradiacion, fotoquimico y ultrasonico de sulfatos de amonio y de potasio, asi como de dicromatos de amonio y de potasio. Seguidamente se dan a conocer nuevos datos experimentales que muestran la influencia del grupo amonio en el recocido termico, por irradiacion ye ultrasonico de fosfatos mono, di y triamonico. Se ha demostrado que en las condiciones de irradiacion neutronica reinantes en-el reactor, el grupo amonio de un compuesto puede transformarse en ciertos fragmentos de retroceso metaestables capaces de dar origen a sustancias reductoras como, por ejemplo, lahidracina. El rendimiento dehidracina aumenta sometiendo las muestras irradiadas con neutrones a un tratamiento ulterior con rayos gamma, ultrasonidos, etc. Paralelamente al aumento del rendimiento de hidracina, se modifica considerablemente la retencion. (author) [Russian] Ammonievaja gruppa mozhet igrat' vazhnuju rol' v razlichnyh processah otzhiga soedinenij ammonija, obluchennyh nejtronami. Issledovalis' nekotorye detali jetogo jeffekta. Dlja togo, chtoby dat' bolee polnuju kartinu jetogo voprosa, vnachale kratko obsuzhdajutsja nekotorye tipichnye,uzhe opublikovannye rezul'taty, kasajushhiesja teplovogo, radiacionnogo

Oxidation-state distribution of plutonium in surface and subsurface waters at Thule, northwest Greenland

International Nuclear Information System (INIS)

McMahon, C.A.; Leon Vintro, L.; Mitchell, P.I.; Dahlgaard, H.

2000-01-01

The speciation of plutonium in Arctic waters sampled on the northwest Greenland shelf in August 1997 is discussed in this paper. Specifically, we report the results of analyses carried out on seawater sampled (a) close to the Thule air base where, in 1968, a US military aircraft carrying four nuclear weapons crashed on sea ice, releasing kilogram quantities of plutonium to the snow pack and underlying seabed sediments, and (b) at a reference station (Upernavik) located ∼400 km to the south. The data show that most of the plutonium in the dissolved phase at Thule is in the form of Pu(V, VI) (mean: 68±6%; n=6), with little if any distinction apparent between surface and bottom waters. Further, the oxidation state distribution at stations close to the accident site is similar to that measured at Upernavik, remote from this site. It is also similar to the distribution observed in shelf waters at mid-latitudes, suggesting that the underlying processes controlling plutonium speciation are insensitive to temperature over the range 0-25 deg. C. Measurements using tangential-flow ultrafiltration indicate that virtually all of the plutonium (including the fraction in a reduced chemical form) is present as fully dissolved species. Most of this plutonium would seem to be of weapons fallout origin, as the mean 238 Pu/ 239,240 Pu activity ratio in the water column (dissolved phase) at Thule (0.06±0.02; n=10) is similar to the global fallout ratio at this latitude (∼0.04). Thus, there is little evidence of weapons-grade plutonium in the water column at Thule at the present time

Plutonium gastrointestinal absorption by adults baboons

International Nuclear Information System (INIS)

Lataillade, G.; Madic, C.; Willemot, J.M.; Germain, P.; Colle, C.; Metivier, H.

1991-01-01

Gastrointestinal absorption of plutonium was investigated in baboons after ingestion of plutonium solution (oxidation states III; IV; V; VI), and plutonium incorporated in soya bean and winkles. We studied the effects of oxidation state and ingested mass for masses ranging from 0.35 μg to 51.6 x 10 +3 μg (4 x 10 -2 to 7776 μg of plutonium per kg of body weight). No clear increase in plutonium retention was shown for concentrations of plutonium smaller than 1 μg/kg. From 1 μg/kg to 1 mg/kg no effects of mass or oxidation state was observed and the mean fractional retention value was 10 -4 . For ingested masses higher than 1 mg/kg the fractional retention values respectively increased for Pu(V) and Pu(III) to (0.9 + 0.2) x 10 -2 and (7.4 + 4.1) x 10 -4 of the ingested mass. This increase might be due to the weak hydrolysis of these oxidation states which would increase gastrointestinal absorption by decrease of hydroxide formation. The fraction of plutonium retained after ingestion of soya bean was (3.0 + 0.5) x 10 -4 about 3 fold higher than the value for 238 Pu nitrate solution. No clear increase in plutonium retention was shown after ingestion of winkles containing 238 Pu. In conclusion, except for high masses of ingested Pu, the retention of which could reach 1% of the ingested dose, our results show that the gastrointestinal transfer factor of 10 -4 proposed by ICRP for gastrointestinal absorption of soluble form of Pu is acceptable, but 10 -3 would provide better safety margin [fr

Mid-year report: IPC liaison and chemistry of thermal reconstitution

International Nuclear Information System (INIS)

Delegard, C.H.

1995-05-01

A program of investigation into the chemistry of alkaline Hanford Site tank waste is being conducted. The investigations have two main subtasks: liaison with the Institute of Physical Chemistry of the Russian Academy of Sciences and further laboratory testing of the chemistry of thermal reconstitution of Hanford Site tank waste. Progress to date includes: (1) a technical dialogue has been established with the Institute scientists; (2) editing of a technical literature review on the chemistry of the transuranic elements and technetium in alkaline media written by researchers at the Institute is complete; (3) four tasks from the Institute have been selected for support by the US Department of Energy; (4) technical information has been supplied to the Institute describing the composition of Hanford Site tank waste; (5) tests, using genuine waste from tank 104-S (a REDOX Process sludge), comparing the performance of thermal reconstitution with enhanced sludge washing show markedly improved dissolution of aluminum achieved by the thermal treatment; (6) a reduction/coprecipitation method was tested and shown to remove plutonium, solubilized by thermal treatment, rapidly and efficiently from solution; (7) technical chemistry support was provided to calciner kinetics tests at the University of Idaho; (8) tests to determine the speciation of plutonium and neptunium solubilized by thermal treatment show dissolved Pu(V) and Np(V) hydroxide complexes are produced, a Np(V) peroxide complex also was identified; (9) recently published data on Pu(IV) carbonate complexation in moderately alkaline (pH 12 to 13) solution led to reexamination of previous investigations of plutonium complexation in highly alkaline (3 to 5 molar NaOH) solutions

Research summary: characterization of radionuclide and moisture movement through arid region sediments

International Nuclear Information System (INIS)

Gee, G.W.; Jones, T.L.; Rai, D.

1981-09-01

This project has the task of understanding the movement of moisture and radionuclides under arid region conditions. This understanding will be used to maximize the isolation of low level waste from the environment. Specific objectives include: field monitoring of moisture and radionuclide transport at an arid region site; assessment of the interaction of radionuclides with unsaturated soils in arid regions; evaluation of radionuclide transport in unsaturated soils by appropriate mathematical models; and assessment of the importance of upward migration of radionuclides by evaporation and diffusion processes. The Burial Waste Test Facility (BWTF) located near Richland, Washington, on the Department of Energy (DOE) Hanford Site has been monitored for water content and radionuclide transport for the past two years. Tritium movement has been observed to depths of 7.6 m in both irrigated and nonirrigated lysimeters. Laboratory tests were conducted to determine how leachate from uranium tailings interacts with geologic materials. Acid leach tailings and tailings solution and geologic materials typical of mill site tailing pits were physically and chemically characterized. Investigation was made of the sorption characteristics of heavy metals and radionuclides on the geologic materials under low and neutral pH conditions. From solubility tests conducted at Pacific Northwest Laboratory, thermodynamic considerations predicted that for the Eh-pH range of natural aqueous environment, the dominant species of Pu is likely to be Pu(V) in relatively oxidizing environments and Pu(III) in reducing environments. Radionuclide transport through unsaturated media was investigated by using two solute transport models to describe the transport of tritium and strontium-85 in laboratory columns. A new approach was used to analyze radon emissions from uranium mill tailings

Causes and outcome of prenatally diagnosed hydronephrosis

Directory of Open Access Journals (Sweden)

Ahmadzadeh Ali

2009-01-01

Full Text Available Hydronephrosis is the most common abnormal finding in the urinary tract on prenatal screening with ultrasonography (U/S. Hydronephrosis may be obstructive or non-obstructive; obstructive lesions are more harmful to the developing kidneys. The aim of the study was to evaluate the causes of renal pelvic dilatation and the outcome of postnatal treatment in infants with hydronephrosis diagnosed prenatally with U/S. We prospectively studied 67 (60 males newborns with hydronephrosis diagnosed prenatally and confirmed postnatally with U/S from Sept. 2005 to Oct. 2007. The patients were allocated to three groups based on the mea-surement of the anteroposterior renal pelvic diameter (APRPD in transverse plane: mild (6-9.9 mm, moderate (10-14.9 mm and severe (> 15 mm hydronephrosis. Voiding cystourethrography (VCUG was obtained in all of the patients to rule out vesicoureteral reflux (VUR. In cases with negative VUR, Diethylenetriamine-pentaacetic acid (DTPA scan with diuretic renography was performed to detect ureteropelvic joint obstruction (UPJO. Twenty two cases (32.8% had mild, 20 (29.9% had moderate, and 25 (37.3% had severe hydronephrosis. The causes of hydroneph-rosis were VUR (40.2%, UPJO (32.8%, posterior urethral valves (PUVs (13.4 %, and transient hydronephrosis (13.4 %. The lesion was obstructive in 37 (55.2% infants. Totally, 33 (49.2% patients with hydronephrosis (9 mild, 9 moderate, and 15 severe subsequently developed com-plications such as UTI and renal insufficiency, or required surgery. Associated abnormalities were observed in 15 (22.4% patients. We conclude that every newborn with any degree of hydro-nephrosis should be assessed postnatally for specific diagnosis and treatment.

Causes and outcome of prenatally diagnosed hydronephrosis

International Nuclear Information System (INIS)

Ahmadzadeh, Ali; Tahmasebi, Morteza; Gharibvand, Mohammad Momen

2009-01-01

Hydronephrosis is the most common abnormal finding in the urinary tract on prenatal screening with ultrasonography (U/S). Hydronephrosis may be obstructive or nonobstructive; obstructive lesions are more harmful to the developing kidneys. The aim of the study was to evaluate the causes of renal pelvic dilatation and the outcome of postnatal treatment in infants with hydronephrosis diagnosed prenatally with U/S. We prospectively studied 67 (60 males) newborns with hydronephrosis diagnosed prenatally and confirmed postnatally with U/S from Sept. 2005 to Oct. 2007. The patients were allocated to three groups based on the mea-surement of the anteroposterior renal pelvic diameter (APRPD) in transverse plane: mild (6-9.9 mm), moderate (10-14.9 mm) and severe (> 15 mm) hydronephrosis. Voiding cystourethrography (VCUG) was obtained in all of the patients to rule out vesicoureteral reflux (VUR). In cases with negative VUR, Diethylenetriamine-pentaacetic acid (DTPA) scan with diuretic renography was performed to detect ureteropelvic joint obstruction (UPJO). Twenty two cases (32.8%) had mild, 20 (29.9%) had moderate, and 25 (37.3%) had severe hydronephrosis. The causes of hydronephrosis were VUR (40.2%), UPJO (32.8%), posterior urethral valves (PUVs) (13.4 %), and transient hydronephrosis (13.4 %). The lesion was obstructive in 37 (55.2%) infants. Totally, 33 (49.2%) patients with hydronephrosis (9 mild, 9 moderate, and 15 severe) subsequently developed complications such as UTI and renal insufficiency, or required surgery. Associated abnormalities were observed in 15 (22.4%) patients. We conclude that every newborn with any degree of hydronephrosis should be assessed postnatally for specific diagnosis and treatment. (author)

Radionuclide sorption in Yucca Mountain tuffs with J-13 well water: Neptunium, uranium, and plutonium. Yucca Mountain site characterization program milestone 3338

International Nuclear Information System (INIS)

Triay, I.R.; Cotter, C.R.; Kraus, S.M.; Huddleston, M.H.

1996-08-01

We studied the retardation of actinides (neptunium, uranium, and plutonium) by sorption as a function of radionuclide concentration in water from Well J-13 and of tuffs from Yucca Mountain. Three major tuff types were examined: devitrified, vitric, and zeolitic. To identify the sorbing minerals in the tuffs, we conducted batch sorption experiments with pure mineral separates. These experiments were performed with water from Well J-13 (a sodium bicarbonate groundwater) under oxidizing conditions in the pH range from 7 to 8.5. The results indicate that all actinides studied sorb strongly to synthetic hematite and also that Np(V) and U(VI) do not sorb appreciably to devitrified or vitric tuffs, albite, or quartz. The sorption of neptunium onto clinoptilolite-rich tuffs and pure clinoptilolite can be fitted with a sorption distribution coefficient in the concentration range from 1 X 10 -7 to 3 X 10 -5 M. The sorption of uranium onto clinoptilolite-rich tuffs and pure clinoptilolite is not linear in the concentration range from 8 X 10 -8 to 1 X 10 -4 M, and it can be fitted with nonlinear isotherm models (such as the Langmuir or the Freundlich Isotherms). The sorption of neptunium and uranium onto clinoptilolite in J-13 well water increases with decreasing pH in the range from 7 to 8.5. The sorption of plutonium (initially in the Pu(V) oxidation state) onto tuffs and pure mineral separates in J-13 well water at pH 7 is significant. Plutonium sorption decreases as a function of tuff type in the order: zeolitic > vitric > devitrified; and as a function of mineralogy in the order: hematite > clinoptilolite > albite > quartz

Sup(239,240)Pu in estuarine and shelf waters of the north-eastern United States

International Nuclear Information System (INIS)

Sholkovitz, E.R.; Mann, D.R.

1987-01-01

The distribution of sup(239,240)Pu between dissolved and particulate forms has been measured in four estuaries on the north-east coast of the United States (Connecticut River, Delaware Bay, Chesapeake Bay, and Mullica River). The data cover the whole salinity range from freshwater input to shelf waters at 3.5% and includes one profile from a nearly anoxic basin in the Chesapeake Bay. In the organic-rich Mullica River estuary, large-scale removal of riverine dissolved sup(239,240)Pu occurs at low salinities due to salt-induced coagulation, a mechanism analogous to that for iron and humic acids. Within the 0 to 2.5-3.5% zone in the other three estuaries, the activity of dissolved sup(239,240)Pu increases almost conservatively. The activities of particulate sup(239,240)Pu are highest in the more turbid waters of low salinity regime (0-1.5%), but become increasingly insignificant with respect to dissolved sup(239,240)Pu as salinities increase. At higher salinities corresponding to shelf water, there is a sharp increase in dissolved sup(239,240)Pu activity. The dissolved sup(239,240)Pu activity within each estuary appears to be inversely related to the flushing time of water. The sharp decrease in dissolved sup(239,240)Pu activities between shelf and estuarine waters appears to be driven by removal within the estuaries themselves rather than on the shelf. Dissolved sup(239,240)Pu activities are lower in the nearly-anoxic bottom waters of Chesapeake Bay indicating enhanced removal by redox transformation of Pu [i.e., Pu(V) to Pu(IV)]. (author)

'Targeted top down' approach for the investigation of UTI: A 10-year follow-up study in a cohort of 1000 children.

Science.gov (United States)

Broadis, E; Kronfli, R; Flett, M E; Cascio, S; O'Toole, S J

2016-02-01

Investigations following urinary tract infection (UTI) aim to identify children who are prone to renal scarring, which may be preventable. In 2002, in an attempt to reduce unnecessary intervention, the present institution standardised the investigation of children with a confirmed UTI. This study aimed to identify the significance of urological abnormalities on investigations following a UTI in children, prior to the introduction of the National Institute for Health and Care Excellence (NICE) guidelines. Clinical information on the first 1000 patients was retrieved from a prospective UTI hospital database. The follow-up period was 10 years. There were 180 males and 820 females (M:F = 1:4.5). The median age of presentation was 5 years (range 11 days-16 years). A renal ultrasound (US) was performed on all patients, and was normal in 93% of cases (n = 889) (see Figure). Of the 7% who had an abnormal US (n = 71), 54 were female and 17 male (M:F = 1:3). A total of 372 DMSA scans were requested and 350 attended their appointment. Of these, 278 cases (79%) were reported as normal, while 72 had an abnormality documented. Of these 72 patients with abnormalities on DMSA scan, 49 had a repeat DMSA scan: 30 demonstrated permanent scarring, while the DMSA scan became normal in 19. Sixteen of the 278 patients whose DMSA scan was initially normal had a repeat DMSA scan due to symptoms, and all scans were normal. Twelve (1.2%) patients required surgical intervention: three underwent circumcision for recurrent UTIs; three underwent endoscopic treatment of VUR; one had a PUV resection; one underwent a cystoscopy; three had a pyeloplasty for pelvi-ureteric junction obstruction; and one had a ureteric reimplantation for vesico-ureteric junction obstruction. After initial investigations and management, 936 patients were discharged from the UTI clinic: 47 of them re-presented - 40 with recurrent UTIs and seven with dysuria. Thirty-five of the 47 children who re-presented with urological

Role of vesicostomy in the management of posterior urethral valve in Sub-Saharan Africa.

Science.gov (United States)

Lukong, C S; Ameh, E A; Mshelbwala, P M; Jabo, B A; Gomna, A; Anumah, M A; Nmadu, P T; Mfuh, A Y

2014-02-01

To review the role of vesicostomy in the management of posterior urethral valve (PUV), in neonates and infants, given the limitations for endoscopic treatment in this setting. A review of 35 patients who presented with posterior urethral valve over a 10-year period. Demographic and clinical information were prospectively recorded on a structured pro forma, and the data extracted analysed using SPSS 11.0. The 35 boys were aged 3 days to 10 years (median 3 weeks). Twenty-three (65.7%) had a vesicostomy (age range 3 days-3 years, median 3 weeks). The mode of presentation was poor urinary stream 15 (65.2%), urinary retention 4 (17.4%), and renal failure 6 (26.1%). Main findings were palpable bladder 23 (100%), hydronephrosis 4 (17.4%). Abdominal ultrasound confirmed hydronephrosis and thickened bladder wall, and voiding/expressive cystourethrogram confirmed dilated posterior urethra and vesicoureteric reflux in all 23 patients. Complications following vesicostomy were stoma stenosis 1 (4.3%), bladder mucosal prolapse 1 (4.3%), perivesicostomy abscess 1 (4.3%); there was no mortality. Following vesicostomy, 10 (43.5%) patients had excision of the valves and vesicostomy closure at age 2-8 years (median 4 years). They are well, with normal renal ultrasonographic findings, bladder capacity range 115-280 ml, and normal urea, serum electrolytes, creatinine, at 3 years of follow up. Thirteen (56.5%) are still awaiting valvotomy but have remained well and with normal ultrasonographic renal findings. Vesicostomy is a useful temporising mode of urinary diversion in neonates and infants with posterior urethral valve (in the absence of unobstructed upper tracts) when facilities for endoscopic valve ablation are not readily available. Copyright © 2013 Journal of Pediatric Urology Company. Published by Elsevier Ltd. All rights reserved.

[Significance of early diagnosis of posterior urethral valves in fetus for further development - own experience].

Science.gov (United States)

Krzemień, Grażyna; Szmigielska, Agnieszka; Wawer, Zofia; Roszkowska-Blaim, Maria

2013-01-01

The incidence of posterior urethral valves is estimated to be from 3:1000 to 8:1000 and this is one of the most common causes of obstruction of urinary tract in boys. About 13-17% of children with posterior urethral valves develop end stage renal failure. We present a  6-month-old boy with late diagnosis of posterior urtehral valves. Antenatal ultrasound investigation of the urinary tract was normal. A small degree of oligohydramnios was found during delivery. At the age of six months the boy was admitted to hospital because of urinary tract infection, hypertension (130/90 mmHg) and acute kidney injury (urea - 46 mg/dL, creatinine - 1.1 mg/dL, GFR - 35.5 mL/min/1.73 m2 ). Bilateral hydronephrosis and megaureters, low-capacity bladder with hypertrophied wall were seen on ultrasound examination. Voiding cystourethrograhy revealed vesicoureteral refluxes (III/V), hypertrophy of the bladder wall with numerous diverticula and dilated posterior urethra. During urethroscopy urethral valves were resected. Increased intravesical pressure (leak point up to 305 cm H2 O) was found on urodynamic test. Renal scintigraphy (99mTc-EC) revealed decreased intake of isotope in the left kidney (5%), and the right kidney intake was 95% ERPF. The patient was qualified for left-sided nephrectomy, which was postponed because of high leak point and high risk of worsening of vesicoureteral reflux to right kidney after nephrectomy. Anticholinergic and α-blocker treatment was started. At the age of 11 months left-side nephrectomy was performed because of recurrent urinary tract infections. After 3.5-year follow-up blood pressure, physical development, kidney function tests, and urinalysis are normal. Additionally to this investigation the significance of early diagnosis including prenatal (PUV) for further development as well as further therapeutic procedure is discussed.

EXTRA·M: a computing code system for analysis of the Purex process with mixer settlers for reprocessing

International Nuclear Information System (INIS)

Tachimori, Shoichi

1994-03-01

A computer code system EXTRA·M, for simulation of transient behavior of the solutes in a multistage countercurrent extraction process, was developed aiming to predict the distribution and chemical behaviors of actinide elements, i.e., U, Pu, Np, and of technetium in the Purex process of fuel reprocessing. The mathematical model is applicable to a complete mixing stagewise contactor such as mixer settler and to the Purex, with tri-n-butylphosphate (TBP) and nitric acid system. The main characteristics of the EXTRA·M are as follows; i) Calculation of distribution ratios of the solutes is based on numerical equations of which parameter values are to be determined by a best fit method with a number of experimental data. ii) Total of 18 solutes; U(IV), U(VI), Pu(III), Pu(IV), Pu(V), Pu(VI), Np(IV), Np(V), Np(VI), Tc(IV), Tc(V), Tc(VI), Tc(VII), Zr(IV), HNO 3 , hydrazine, hydroxylamine nitrate and nitrous acid, are treated and rate equations of total 40 chemical reactions involving these solutes are incorporated. iii) Instantaneous change of flow conditions, i.e., concentration of the solutes and flow rate of the feeding solutions, is contrived by computation. iv) Reflux or bypass mode calculation, in which an aqueous raffinate stream is transferred to the preceding bank or stage, is possible. The present report explains the concept, assumptions and characteristics of the model, the material balance equations including distribution and reaction rate equations and their solution method, and the usefulness of the model by showing some examples of the verification results. A description and source program of EXTRA·M1, as an example, are listed in the annex. (J.P.N.) 63 refs

Profile of urinary tract infections in paediatric patients

Directory of Open Access Journals (Sweden)

Palak Gupta

2015-01-01

Full Text Available Background & objectives: This cross-sectional study was conducted at a tertiary care centre in Puducherry, south India, with the aim of finding the profile of the paediatric urinary tract infection (UTI, bacterial pathogens involved, and also to observe vesicoureteric reflux (VUR and renal scarring in these patients. Methods: A total of 524 paediatric patients ≤13 yr, suspected to have UTI, were included in the study. Urine samples were collected, processed for uropathogen isolation and antibiotic susceptibility test was performed as per the Clinical and Laboratory Standards Institute (CLSI guidelines. Thirty two culture proven children with UTI underwent micturating cysto-urethrography (MCU and dimercaptosuccinic acid (DMSA scanning was done for 69 children. Results: o0 f the 524 children, 186 (35.4% had culture proven UTI with 105 (56.4% being infants, 50 (27.4% between 1-5 yr, 30 (16.12% between 5-13 yr and 129 (69.35% males. Posterior urethral valve (PUV was noted in three, hydronephrosis in one, VUR in 18 and renal scarring in 33. VUR as well as renal scarring were more in males >1 yr of age. A significant association (P=0.0054 was noted with a combined sensitivity and specificity of these investigations being 83 and 90 per cent, respectively of the MCU and DMSA scans for detecting VUR. Escherichia coli was the most common pathogen isolated, sensitive to nitrofurantoin, followed by cefoperazone-sulbactam, aminoglycosides and meropenem. Interpretation & conclusions: Our results indicate that UTI varies with age and gender and extensive evaluation is required in boys under one year of age with UTI. This study also highlights the better efficacy of aminoglycosides, cefoperazone-sulbactam and nitrofurantoin in vitro compared with meropenem in Gram-negative uropathogens.

Profile of urinary tract infections in paediatric patients

Science.gov (United States)

Gupta, Palak; Mandal, Jharna; Krishnamurthy, Sriram; Barathi, Deepak; Pandit, Nandini

2015-01-01

Background & objectives: This cross-sectional study was conducted at a tertiary care centre in Puducherry, south India, with the aim of finding the profile of the paediatric urinary tract infection (UTI), bacterial pathogens involved, and also to observe vesicoureteric reflux (VUR) and renal scarring in these patients. Methods: A total of 524 paediatric patients ≤13 yr, suspected to have UTI, were included in the study. Urine samples were collected, processed for uropathogen isolation and antibiotic susceptibility test was performed as per the Clinical and Laboratory Standards Institute (CLSI) guidelines. Thirty two culture proven children with UTI underwent micturating cysto-urethrography (MCU) and dimercaptosuccinic acid (DMSA) scanning was done for 69 children. Results: of the 524 children, 186 (35.4%) had culture proven UTI with 105 (56.4%) being infants, 50 (27.4%) between 1-5 yr, 30 (16.12%) between 5-13 yr and 129 (69.35%) males. Posterior urethral valve (PUV) was noted in three, hydronephrosis in one, VUR in 18 and renal scarring in 33. VUR as well as renal scarring were more in males >1 yr of age. A significant association (P=0.0054) was noted with a combined sensitivity and specificity of these investigations being 83 and 90 per cent, respectively of the MCU and DMSA scans for detecting VUR. Escherichia coli was the most common pathogen isolated, sensitive to nitrofurantoin, followed by cefoperazone-sulbactam, aminoglycosides and meropenem. Interpretation & conclusions: Our results indicate that UTI varies with age and gender and extensive evaluation is required in boys under one year of age with UTI. This study also highlights the better efficacy of aminoglycosides, cefoperazone-sulbactam and nitrofurantoin in vitro compared with meropenem in Gram–negative uropathogens. PMID:26112850

Radiation Synthesis of Stannous Dibromodibutyl; Synthese radiochimique de l'etain dibromopibutyle; Radiatsionno-khimicheskij sintez dibromdibutilolova; Sintesis radioquimica del dffiromodibutilestano

Energy Technology Data Exchange (ETDEWEB)

Abramova, L. V.; Vereshchinskij, I. V.; Kocheshkov, K. A.; Miretskij, V. Yu.; Pozdneev, V. V.; Ryabukhin, Yu. S.; Sheverdina, N. I.

1963-11-15

dosimetro de sulfato de hierro es de {approx}50 rad/s. Se utilizaron diversas proporciones de estafio metalico en polvo y bromuro de butilo de distintos grados de pureza. Se comprobo que en tales condiciones se desarrolla una reaccion radioquimica orientada en virtud de la cual se produce basicamente dibromodibutilestaflo con elevado rendimiento. Se demostro que el proceso tiene un periodo de induccion cuya duracion depende de la pureza del bromuro de butilo inicial. Este mismo factor influye tambien notablemente en la velocidad de formacion del producto final. Se comprobo que el estafio que no interviene en la reaccion puede volver a utilizarse para obtener dibromodibutilestaflo, pero en ese caso se anula por completo el periodo de induccion. Estas propiedades satisfacen los requisitos para la realizacion de un proceso continuo. Los autores proponen un mecanismo de reaccion, para explicar las leyes de este proceso que se desarrolla con un elevado rendimiento radioquimico. (author) [Russian] Printsipial'naya vozmozhnost' sinteza olovoorganicheskikh soedinenij pri dejstvii {gamma}-izlucheniya Co{sup 60} na smesi metallicheskogo olova i sootvetstvuyushchikh galoidalkilov vpervye byla ustanovlena Abramovoj, Kocheshkovym i SHeverdinoj v 1956 g. Usloviya provedeniya opytov v steklyannoj apparature bez peremeshivaniya ne pozvolyali vyyavit' kineticheskie zakonomernosti obrazovaniya ehtogo klassa metalloorganicheskikh soedinenij. Nastoyashchaya rabota byla postavlena dlya vyyasneniya vliyaniya ryada faktorov na skorost' radiatsionno-khimicheskogo sinteza olovoorganicheskikh soedinenij na primere dibromdibutilolova. S ehtoj tsel'yu byla skonstruirovana i izgotovlena spetsial'naya ustanovka s periodicheskoj zagruzkoj komponentov i vygruzkoj produktov reaktsii. Otlichitel'nymi osobennostyami ustanovki yavlyalis' vozmozhnost' ee termostatirovaniya, osushchestvlenie ehffektivnogo peremeshivaniya i periodicheskogo otbora prob dlya analizov. Osnovnoj uzel ustanovki (reaktsionnyj sosud iz

Some symmetrical halogen and methoxy exchange reactions in aromatic systems; Quelques reactions symetriques d'echanges d'halogenes et de groupes methoxyles dans les composes aromatiques; Simmetricheskie reaktsii s galoidnym i metoksidnym obmenom v aromaticheskikh sistemakh; Algunas reacciones simetricas de intercambio de halogenos y grupos metoxilo en compuestos aromaticos

Energy Technology Data Exchange (ETDEWEB)

Broadbank, R W.C.; Harhash, A H.E.; Kanchanalai, S [Leicester College of Technology and Commerce, Leicester (United Kingdom)

1962-03-15

. Los autores describen seguidamente la preparacion de ciertos compuestos nitrometoxi- aromaticos marcados con carbono-14 en el grupo metoxilo. Estudiaron reacciones simetricas de intercambio de grupos metoxilo entre estos compuestos e iones metoxilo disueltos en metanol. Despues ele separar los reactivos (en muestras de la meczla tomada a intervalos adecuados) por extraccion con tolueno y agua, recuperaron los compuestos aromaticos y determinaron sus actividades especificas por recuento mediante un fosforo ele plastico. Al analizar los resultados experimentales, dedican particular atencion a la influencia ejercida por la fuerza ionica sobre la velocidad especifica de reaccion. Establecen comparaciones con los efectos ele la fuerza ionica observados en las reacciones simetricas nucleofilicas biomoleculares en un atomo de carbono (alifatico) saturado, y mencionan algunas otras reacciones de sustituciones nucleofilicas en compuestos aromaticos. (author) [Russian] Izotopnye indikatory nezamenimy pri izuchenii kinetiki reaktsij s nukliofil'nosimmetricheskim zameshcheniem pri aromaticheskom atome ugleroda. Obmen joda mezhdu jodo-nitro-aromaticheskimi soedineniyami i ionami jodida v atsetonovom ili metanolovom rastvore izuchalsya kak s kachestvennoj, tak i kolichestvennoj tochek zreniya posredstvom mecheniya ionov jodida jodom-131. U smesi reaktsii pri opredelennykh intervalakh vremeni bralis' obraztsy, dva reaktanta razdelyalis' toluolovodnoj ehkstraktsiej, a khod reaktsii opredelyalsya beta-otschetom zhidkostnogo schetchika Gejgera-Myullera. Izmereniya rasprostranyalis' takzhe na ''svobodnye ot nositelya'' kontsentratsii ionov jodida. Privoditsya opisanie prigotovleniya nekotorykh nitro-metoksi-aromaticheskikh soedinenij, mechennykh uglerodom-14 v metoksinovoj gruppe. Privoditsya issledovanie reaktsij simmetricheskogo metoksinovogo obmena ehtikh soedinenij s metoksidnymi ionami v metanovom rastvore. Posle otdeleniya reaktantov (iz obraztsov smesi reaktsii, vzyatykh cherez

Reviews | Reseñas de libros

Directory of Open Access Journals (Sweden)

Pasado y Memoria

2012-12-01

Full Text Available Contiene: CALATAYUD, Santiago; MILLÁN, Jesús; ROMEO, María Cruz (eds., Estado y periferias en la España del siglo XIX. Nuevos enfoques, Valencia, PUV, 2009, 459 pp. / Juan Antonio Inarejos Muñoz ; VILAR, Juan Bautista; VILAR, María José, Mujeres, Iglesia y Secularización. El Monasterio de Santa Clara la Real de Murcia en el tránsito de la Ilustración al Liberalismo (1788-1874, Murcia, Universidad de Murcia, 2012, 498 pp. / Francisco Manuel Pastor Garrigues ; SEBASTIÁ ALCARAZ, Rafael (coord., Las escuelas normales de la provincia de Alicante durante el siglo XIX, San Vicente del Raspeig, Editor Ramón Torrés, 2012, 131 pp. / José Miguel Santacreu Soler ; GÓMEZ REUS, Teresa (ed., Mujeres al frente. Testimonios de la Gran Guerra, Madrid, Huerga y Fierro Editores, 2012, 238 pp. / Mónica Moreno Seco ; VILLA GARCÍA, Roberto, La República en las urnas. El despertar de la democracia en España, Madrid, Marcial Pons, 2011, 530 pp. / Juan Martínez Leal ; GRAU, Vicent, La Segona República a Castelló. Una memoria històrica positiva, pròleg de Rosa Monlleó, Castelló de la Plana, Publicacions de la Universitat Jaume I, 2012, 465 pp. / Ricard Camil Torres Fabra ; TOMASONI, Matteo, ACCIAI, Enrico, GRASSIA, Edoardo (a cura di, «Spagna Anno Zero»: la guerra come soluzione, dossier monográfico publicado en Diacronie. Studi di Storia Contemporanea, nº 7 (luglio 2011, en línea en . / Gaspar Díez Pomares ; BJERG, María, El viaje de los niños. Inmigración, infancia y memoria en la Argentina de la segunda posguerra, Buenos Aires, Edhasa, 2012, 150 pp. / Bárbara Ortuño Martínez ; TELTSCHIK, Horst, 329 días. Desde la caída del Muro hasta la reunificación alemana, Barcelona, Círculo de Lectores, 1992, 427 pp. / Félix Gil Feito ; MARIMON, Antoni; SERRA, Sebastià (dirs., Diccionari de Partits Polítics de les Illes Balears (1900-2008, Palma, Lleonard Muntaner Editor, 2012, 460 pp. / José Miguel Santacreu Soler.

Radioisotopes as tracers for reactions in molten fluoride media; Les radioisotopes comme indicateurs des reactions se produisant dans des milieux de fluorures fondus; Ispol'zovanie radioizotopov v kachestve indikatorov dlya reaktsij v rasplavlennoj ftoristoj srede; Los radioisotopos como indicadores de las reacciones que tienen lugar en un medio de fluoruros fundidos

Energy Technology Data Exchange (ETDEWEB)

Grimes, W R; Shaffer, J H; Strehlow, R A; Ward, W T; Watson, G M [Oak Ridge National Laboratory, Oak Ridge, TN (United States)

1962-03-15

produce un aumento de la concentracion de radioisotopos en la solucion, de conformidad con la ley de accion de masas. Cuando se enfrian ciertas mezclas de LiF y BeF{sub 2} fundidas que contengan CeF{sub 3} y fluoruros de las tierras raras, la fase primaria consiste en una solucion solida de los trifluoruros. Los autores han evaluado los equilibrios entre la solucion fundida y la solucion solida, para diversos pares de fluoruros. No han observado ninguna desviacion notable respecto de la ley de accion de masas. Los autores logran la separacion de diversas especies por precipitacion selectiva de los oxidos a partir de soluciones de fluoruros fundidos. (author) [Russian] Putem ispol'zovaniya sootvetstvuyushchikh radioizotopov i standartnykh metodov otscheta byli izucheny khimicheskie reaktsii, kotorye mogut okazat'sya poleznymi dlya udaleniya nekotorykh sostavnykh chastej iz rasplavlennykh ftoristykh rastvorov. Byli izucheny sleduyushchie kategorii reaktsij: 1) izotopnyj obmen mezhdu rastvorennym indikatorom i nerastvorimymi slozhnymi veshchestvami; 2) raspredelenie rastvorennogo indikatora mezhdu rasplavom i rastvorom analogichnogo slozhnogo veshchestva v tverdom sostoyanii i 3) osazhdenie radioizotopa v kachestve nerastvorimogo slozhnogo veshchestva. V tipichnykh ehksperimentakh nablyudalos', chto radioaktivnyj indikator LaF{sub 3} v rasplavakh LiF-NaF bystro obmenivaetsya na neaktivnyj La{sub 2}O{sub 3}. V ehtom rastvoritele analogichnyj bystryj obmen proiskhodit mezhdu radioaktivnym indikatorom CeF{sub 3} i neaktivnym CeO{sub 2}; trebuemoe v poslednem sluchae perenesenie ehlektrona ochevidno ne prepyatstvuet ehtoj reaktsii. V sootvetstvii s printsipom massovogo dejstviya dobavlenie k kazhdoj iz ehtikh sistem neaktivnogo CeF{sub 3} uvelichivalo soderzhanie radioaktivnogo indikatora v rastvore. Pri okhlazhdenii nekotorykh rasplavov ZiF-BeF{sub 2}, soderzhashchikh CeF{sub 3}, i redkikh zemel' v kachestve pervichnoj fazy obrazuetsya tverdyj rastvor triftoristykh soedinenij

The Estimation of Internal Contamination with Uranium from Urine Analysis Results; Evaluation de la Contamination Interne par l'Uranium a Partir des Resultats de l'Analyse d'Urines; 041e 0426 0414 ; Evaluacion de la Contaminacion Interna con Uranio a Partir de los Resultados del Analisis de Orina

Energy Technology Data Exchange (ETDEWEB)

Jackson, S. [Authority Health and Safety Branch, Radiological Protection Division, United Kingdom Atomic Energy Authority, Harwell, Berks. (United Kingdom)

1964-11-15

tejido oseo es menos peligrosa, eh el caso del uranio natural, que la toxicidad para el rinon. Cuando se trata de compuestos solubles de uranio altamente enriquecido cuya actividad especifica es elevada, la consideracion primordial es de caracter radiologico; los efectos quimicos en los rinones son menos peligrosos ijue la irradiacion del esqueleto qiie, por tanto, ha de considerarse como el organo critico. En este caso, es preferible tratar de evaluar la carga retenida en el cuerpo, y no la absorcion de uranio. Esta operacion se puede efectuar analizando muestras de orina tomadas no inmediatamente despues de la exposicion, sino al cabo de algun tiempo. Probablemente, el material mas indicado en la practica son las muestras tomadas al termino de unas vacaciones, pero en algunos casos puede ser necesario aceptar muestras tomadas despues de un fin de semana durante el que la persona interesada no haya concurrido al trabajo. (author) [Russian] Naibolee chastoj prichinoj popadanija urana v organizm javljaetsja vdyhanie uranovoj pyli. Rastvorimye uranovye soedinenija bystro vsasyvajutsja iz legkih, i bol'shaja chast' urana, popadajushhego v krovotok, vydeljaetsja s mochoj; Stepen' pogloshhenija rastvorimogo urana vo vremja rabot mozhet byt opredelena'na osnove soderzhanija urana v probah mochi, vzjatyh neposredstvenno posle jetogo. Harakternoj chertoj rastvorimyh soedinenij prirodnogo urana javljaetsja ne radiologicheskoe porazhenie, svjazannoe s himicheskim jeffektom urana, osevshego v pochkah. Chast' urana osedaet v kostjah skeleta, no obluchenie kostej javljaetsja menee kriticheskim v sluchae prirodnogo urana, chem toksichnost dlja pochek. Dlja rastvorimyh soedinenij vysokoobogashhennogo urana, imejushhih vysokuju specificheskuju aktivnost, glavnoj opasnost'ju javljaetsja radiologicheskaja; himicheskie jeffekty v pochkah menee opasny, chem obluchenie kostej', kotorye, takim obrazov stanovjatsja kriticheskim organom. V jetom sluchae luchshe popytat'sja opredelit

[Effects of different surface treatments on the zirconia-resin cement bond strength].

Science.gov (United States)

Liao, Y; Liu, X Q; Chen, L; Zhou, J F; Tan, J G

2018-02-18

To evaluate the effects of different surface treatments on the shear bond strength between zirconia and resin cement. Forty zirconia discs were randomly divided into four groups (10 discs in each group) for different surface treatments: control, no surface treatment; sandblast, applied air abrasion with aluminum oxide particles; ultraviolet (UV), the zirconia sample was placed in the UV sterilizer at the bottom of the UV lamp at 10 mm, and irradiated for 48 h; cold plasma, the discs were put in the cold plasma cabinet with the cold plasma generated from the gas of He for 30 s. Specimens of all the groups were surface treated prior to cementation with Panavia F 2.0 cement. The surface morphology and contact angle of water were measured. The shear bond strengths were tested and the failure modes were examined with a stereomicroscope. Surface morphology showed no difference between the UV/cold plasma group and the control group. Sandblasted zirconia displayed an overall heterogeneous distribution of micropores. The contact angle of the control group was 64.1°±2.0°. After sandblasting, UV irradiation and cold plasma exposure, the values significantly decreased to 48.8°±2.6°, 27.1°±3.6° and 32.0°±3.3°. The values of shear bond strength of the specimens with sandblasted (14.82±2.01) MPa were higher than those with no treatment (9.41±1.07) MPa with statistically significant difference (Pbond strength of the specimens with UV irradiation (10.02±0.64) MPa were higher than those with no treatment (9.41±1.07) MPa, but without statistically significant difference (P>0.05). The values of cold plasma group (18.34±3.05) MPa were significantly higher than those of control group (9.41±1.07) MPa, even more than those with sandblast(14.82±2.01) MPa (PUV and cold plasma treatment. The surface C/O ratio also decreased after UV and cold plasma treatment. Zirconia specimens treated with UV and cold plasma could significantly improve the hydrophilicity. The surface

The consideration and representation of retention processes in the WIPP performance assessment: justification of adopted approaches and interaction with the regulator. Part 2: EPA review process and approval justification

International Nuclear Information System (INIS)

Byrum, Ch.; Peake, T.

2002-01-01

The Environmental Protection Agency (EPA) was directed by Congress to review whether the Waste Isolation Pilot Plant (WIPP) would comply with EPA regulations on radioactive waste disposal. The review of the effectiveness of retardation in the Culebra Dolomite Member of the Rustler Formation was a major focus of the Agency's review since the Culebra is postulated to be the major long-term pathway for the movement of radionuclides. EPA review consisted of reviewing the Department of Energy's (DOE) data as well as conducting separate evaluations and modelling. EPA independent evaluation identified several issues of concern: First, steady-state conditions did not appear to be reached in some experiments. Second, the effect of actinide concentration did not appear to be addressed. Third, the effect of magnesium oxide backfill in the repository for creating alkaline pH conditions in the brines passing through was not considered. Fourth, the experiments for Am(III) failed for various reasons and Pu(V) was used to represent Am(III). EPA also considered other concerns voiced by different reviewers in its review. After receipt of information supplemental to DOE's Compliance Certification Application (CCA), EPA was able to determine that the experimental foundation supported the retardation conceptual model in the Culebra and the parameters used were adequate. EPA independent modelling confirmed DOE's modelling that indicated radionuclide releases through the Culebra would be greatly reduced by even low K d values. However, EPA did determine that DOE should have used a log-uniform probability distribution for the retardation distribution coefficients (K d s)instead of the uniform probability distribution used in DOE's compliance calculations. EPA required an additional Performance Assessment (PA), called the Performance Assessment Verification Test (PAVT). The change in the K d distribution from uniform to log-uniform was incorporated for the K d values used in the PAVT. The

Extensions of the techniques for the accelerated unspecific isotopic labelling of organic compounds; Applications nouvelles des techniques accelererees du marquage non specifique de composes organiques; Rasprostranenie metodov uskoreniya mecheniya nespetsifichnymi izotopami organicheskikh slozhnykh soedinenij; Nuevas aplicaciones de las tecnicas de marcacion inespecifica acelerada de compuestos organicos

Energy Technology Data Exchange (ETDEWEB)

Ghanem, N A [National Research Centre, El-Dokki, Cairo (Egypt); Westermark, T [Division of Physical Chemistry, Royal Institute of Technology, Stockholm 70 (Sweden)

1962-03-15

The paper aims at reviewing new means of obtaining acceleration in the reaction of a radioactive gas with a target material to be labelled and examples of successful cases. The techniques include the use of microwave and radiowave discharges, glow discharges affected through DC or AC sources, and simply ultraviolet radiation. Specific activities of more than 100 mc/g in purified significant quantities of products were obtained. Periods of exposure to discharge were of the order of one minute and decomposition was limited in most cases. Calculations of utilization of the energy absorbed during the labelling process were compared with the energy from ionizing radiation used by Wilzbach and others, and G values for isotope replacement are given. In polystyrene labelling, evidence is found that the mechanisms is governed by an atom-molecule reaction. (author) [French] Les auteurs passent en revue des methodes recentes visant a accelerer la reaction d'un gaz radioactif avec des matieres a marquer; ils citent des cas de reussite. Les techniques etudiees comportent l'emploi de decharges de micro-ondes et d'ondes hertziennes, de decharges luminescentes par des sources de courant continu ou alternatif et de simples rayons ultraviolets. On a obtenu des activites specifiques superieures a 100 mc/g dans des quantites importantes de produits purifies. Les temps d'exposition a la decharge etaient de l'ordre d'une minute; dans la plupart des cas, la decomposition etait limitee. Les auteurs comparent la quantite d'energie absorbee au cours du marquage a celle qui est necessaire lorsqu'on emploie des rayonnements ionisants, comme l'ont fait Wilzbach et autres; ils donnent les valeurs G de remplacement des isotopes. Dans le marquage du polystyrene, il semble bien que le processus soit regi par une reaction atome-molecule. (author) [Spanish] El objeto de la memoria es pasar revista a nuevos metodos para acelerar la reaccion de un gas radiactivo con el material de blanco que se desea marcar, y citar ejemplos en los que este procedimiento se ha empleado con exito. Las diversas tecnicas se basan en el uso de descargas de microondas y de ondas hertzianas, descargas luminiscentes producidas por corriente continua, o alterna, o sencillamente rayos ultravioleta. Se han obtenido cantidades considerables de productos purificados con actividades superiores a 100 mcuries/g. Los tiempos de exposicion a las descargas son del orden de un minuto, y en la mayoria de los casos se observo poca descomposicion. Los autores calcularon el rendimiento energetico alcanzado en estos metodos de marcacion y lo comparan con el correspondiente a las radiaciones ionizantes empleadas por Wilzbach y otros investigadores; tambien dan los valores de G para la sustitucion isotopica. Existen pruebas de que la marcacion del poliestireno se produce en virtud de una reaccion atomo-molecula. (author) [Russian] Tsel'yu nastoyashchego doklada yavlyaetsya rassmotrenie novykh sposobov uskoreniya reaktsii mezhdu radioaktivnym gazom i materialom misheni, podlezhashchim mecheniyu, a takzhe privedenie primerov uspeshnykh sluchaev. Ehti metody vklyuchayut ispol'zovanie razryadov mikrovoln i radiovoln, tleyushchikh razryadov pod vozdejstviem istochnikov postoyannogo ili peremennogo tokov, ili prosto radiatsii ul'trafioletovykh luchej. Byla dostignuta udel'naya aktivnost', dokhodyashchaya do 100 mikrokyuri na gramm, v znachitel'nykh kolichestvakh ochishchennogo produkta. Vremya vozdejstviya razryada bylo poryadka odnoj minuty, i vo mnogikh sluchayakh razlozhenie bylo chrezvychajno ogranichennym. Dayutsya podschety ehffektivnosti ispol'zovaniya ehnergii dlya proizvodstva mecheniya ehtimi metodami po sravneniyu s zatratoj dlya toj zhe tseli ehnergii ioniziruyushchego izlucheniya, ispol'zuemoj Vil'tsbakhom i dr. ; krome togo, ukazyvayutsya znacheniya radiatsionnokhimicheskogo vykhoda G dlya zameny izotopov. Est' ukazaniya na to, chto pri mechenii polistirola mekhanizm opredelyaetsya reaktsiej atom-molekula. (author)

Radioisotopes in the physical chemistry of corrosion processes and their inhibition; Les radioisotopes dans la chimie physique des processus de corrosion et de leur inhibition; Primenenie radioizotopov v fizicheskoj khimii protsessov korrozii i ikh tormozheniya; Los radioisotopos en la quimica fisica de los procesos de corrosion y de inhibicion

Energy Technology Data Exchange (ETDEWEB)

Cartledge, G H [Chemistry Division, Oak Ridge National Laboratory, Oak Ridge, TN (United States)

1962-03-15

periodico, es particularmente adecuado para algunos de estos estudios. Las ventajas do este elemento estriban, en sus propiedades nucleares. La memoria resume las propiedades quimicas de los compuestos de tecnecio y las compara con las de los compuestos correspondientes de {sup 51}Cr, de molibdeno y de wolframio, que con tanta frecuencia se emplean en el estudio de la inhibicion. La memoria describe seguidamente ciertos estudios experimentales como ejemplo de los usos a que se ha destinado el tecnecio en los trabajos de este tipo. Entre ellos menciona estudios empiricos de su accion como eficaz inhibidor de la corrosion del hierro, y observaciones de la actividad de superficie realizadas durante periodos largos de tiempo. Otros estudios efectuados con {sup 99}Tc y con {sup 131}I han demostrado la importancia de la adsorcion competitiva de iones en la determinacion de la cinetica de los procesos de corrosion y de inhibicion. Como tercer ejemplo, describe como las propiedades excepcionales del tecnecio han permitido distinguir claramente las contribuciones relativas del oxigeno de las del inhibidor oxidante en el mantenimiento de la pasividad. (author) [Russian] Sredi faktorov, vkhodyashchikh v fundamental'noe izuchenie ehlektrokhimicheskikh protsessov korrozii i tormozheniya, vydelyayutsya v chastnosti sleduyushchie: a) razlichnye vidy adsorbtsionnykh yavlenij; b) ionoobmennye svojstva passivnykh plenok; c) ehlektrokhimicheskaya kinetika kak anodnykh, tak i katodnykh protsessov, proiskhodyashchikh mezhdu metallom i korrozijnoj sredoj. Teper' pri pomoshchi radioizotopov mozhno provesti nekotorye issledovaniya ehtikh yavlyaenij, kotorye nevozmozhno osushchestvit' obychnymi sredstvami. Tekhnetsij, gomolog margantsa v periodicheskoj sisteme, okazalsya ves'ma podkhodyashchim dlya nekotorykh ehtikh issledovanij. Ego yadernye svojstva krajne interesny u ehtom otnoshenii. V doklade kratko izlagayutsya khimicheskie svojstva soedinenij tekhnetsiya, protivopostavlennye svojstvam

Application of radioisotopes to studies of crystal imperfections; Application des radioisotopes a l'etude des imperfections des cristaux; Primenenie radioizotopov dlya izucheniya defektov v kristallakh; Aplicaciones de los radioisotopos al estudio de las imperfecciones cristalinas

Energy Technology Data Exchange (ETDEWEB)

Sproull, R L; Slack, G A; Moss, M; Pohl, R O; Krumhansl, J A [Laboratory of Atomic and Solid State Physics, Cornell University, Ithaca, NY (United States)

1962-01-15

indicadores anadidos. La segunda aplicacion consiste en introducir en los haluros alcalinos pequenas cantidades de iones-impureza a fin de poder estudiar la dispersion de fonones causada por dichas impurezas, o por los huecos que crean en la red cristalina; los autores efectuan las mediciones correspondientes a temperaturas muy bajas, ya que en tales condiciones las imperfecciones de la red imponen limitaciones al libre recorrido medio de los fonones. En estos trabajos han empleado generalmente el radioisotopo {sup 45}Ca. Los autores pasan revista a los resultados de su labor, citan algunas aplicaciones actuales de los radioisotopos en este campo y formulan observaciones sobre sus posibles aplicaciones en lo futuro. (author) [Russian] Radioizotopy byli ispol'zovany v dvukh vazhnykh napravleniyakh dlya izucheniya defektov v shchelochnykh galoidnykh kristallakh. Zonal'noe rafinirovanie soedinenij proveryalos' izotopnymi indikatorami, a koehffitsienty izolyatsii opredelyalis' iz poluchennykh dannykh. Drugoe primenenie zaklyuchalos' v vvedenii nebol'shikh kontsentratsij primesej ionov v shchelochnye galoidy s tem, chtoby izuchit' rasseyanie fononov takimi defektami ili vakansiyami, imi vyzyvaemymi; ehti izmereniya proizvodyatsya pri ochen' nizkikh temperaturakh, pri kotorykh srednyaya velichina svobodnogo probega fonona ogranichivaetsya defektami reshetki. Radioizotopom, poluchivshim naibolee shirokoe primenenie, yavlyaetsya kal'tsij-45. (author)

Micturating cystourethrogram as a tool for investigating UTI in children - An institutional audit.

Science.gov (United States)

Hua, L; Linke, R J; Boucaut, H A P; Khurana, S

2016-10-01

Micturating cystourethrograms (MCUG) are the gold standard for evaluating vesicoureteric reflux (VUR). There is a growing consensus for increasing the threshold for performing MCUGs following urinary tract infections (UTI) in children. There are several varying guidelines. It is important to detect high-grade reflux in the setting of an UTI because of potential long-term complications. This audit aimed to retrospectively: (1) identify the conformance rate of local guidelines at the Women's and Children's Hospital (WCH); (2) assess predictors for an abnormal MCUG; and (3) compare local guidelines against the Royal Children's Hospital, Melbourne (RCH), National Institute for Healthcare and Excellence (NICE), and American Academy of Pediatrics (AAP) guidelines for selectively detecting high-grade reflux. The number of MCUGs performed from 2008 to 2012 at the WCH radiology department was collected. Patients undergoing MCUG during the 2012 calendar year were identified. Only children having an initial MCUG as part of an UTI investigation with prerequisite imaging as per guidelines were included. Each child's age, sex, referral source, reason, renal ultrasound (RUS) prior to the MCUG, MCUG result and VUR grade were recorded. The WCH guidelines were applied to determine conformance, to evaluate predictors for an abnormal MCUG, and compared against other retrospectively applied guidelines (RCH, NICE, AAP). There was complete data for 168 children who underwent MCUG as part of an UTI investigation (median age 0.79 years, range 0.12-8.74, male:female 67:101). There were 67/168 abnormal MCUGs (62 children with VUR, five bladder diverticulum), and 97 refluxing renal units (43 high-grade VUR units). No posterior urethral valves (PUV) were identified as part of the UTI investigation. A total of 143/168 patients had prior RUS (normal:abnormal 67:76). The WCH guidelines had 82% conformance. There was no statistically significant association between an abnormal MCUG and age, sex

Comparative Studies of Chemical Effects following Nuclear Reactions and Transformations on Metal Organic Phenyl Compounds; Etudes Comparatives des Effets Chimiques Induits par les Reactions et les Transformations Nucleaires sur des Composes Phenylmetalliques; 0421 0420 0410 0414 ; Estudios Comparativos de los Efectos Quimicos de las Reacciones y Transformaciones Nucleares en Compuestos Fenil-Organometalicos

Energy Technology Data Exchange (ETDEWEB)

Merz, E.; Riedel, H. J. [Kernforschungsanlage, Juelich, Federal Republic of Germany (Germany)

1965-04-15

retroceso secundarios (interacciones elasticas e inelasticas), entre ellas la influencia peculiar del oxigeno. (author) [Russian] Izuchenie himicheskih jeffektov, sozdavaemyh v processe jadernyh reakcij atomami otdachi bol'shoj jenergii v tverdyh telah i zhidkostjah, provodilos' na osnovanii shirokogo sopostavlenija produktov, obrazovannyh reakcijami (p,{gamma}) i (p, 2p) v soedinenijah fenila s metallami , kak to: germaniem, olovom, svincom, mysh'jakom i sur'moj. V dopolnenie k jetomu radioaktivnye produkty otdachi, obrazovannye posle K-zahvata na tetrafenile germanija-68, sravnivajutsja s rezul'tatami reakcii (p,7) na trifenile gallija i reakcii (p, {gamma}) na tetrafenile germanija. Nakonec, jeto issledovanie rasprostranilos' na {beta}{sup -}-perehod tetrafenila germanija-77 v mysh'jak-77. S pomoshh'ju razlichnyh metodov otdelenija, naprimer, hromatografii adsorbcii na glinozeme, ionnogo obmena i jelektroforeza byli otdeleny razlichnye radioaktivnye produkty otdachi i opredeleny vyhody kazhdogo iz nih. Ustanovleno, chto v jadernyh reakcijah soedinenij vysheupomjanutyh metallov, imejushhih odinakovuju strukturu svjazej, obrazujutsja pochti te zhe kategorii produktov otdachi. Odnako raspredelenie vyhodov obnaruzhivaet harakternye rashozhdenija mezhdu reakcijami (p,{gamma}) i reakcijami (p, 2p). Obnaruzhivaetsja tol'ko neznachitel'noe vlijanie obluchenija na vyhody pri vozdejstvii ego sootvetstvenno na zhidkosti i rastvory. Porazhajut znachitel'nye rashozhdenija, obnaruzhivaemye dlja novyh soedinenij, poluchennyh v rezul'tate jadernyh prevrashhenij; jeti rashozhdenija kasajutsja ne tol'ko vida tipichnyh produktov, no takzhe i procentnoj doli ih vyhoda. Tak, naprimer, rjad produktov otdachi germanija i gallija metalloorganicheskogo haraktera byli obnaruzheny v jadernyh reakcijah na tetrafenile germanija-77, chego vovse ne nabljudalos' pri processah K-zahvata na tetrafenile germanija-68. {beta}{sup -}-raspad na tetrafenile germanija-77 vedet k obrazovaniju pochti takih zhe

Production of C{sup 14}-labelled compounds from C{sup 14}O{sub 2} accelerated in an electric field - Physico-chemical analysis of some radioactive compounds obtained; Production de composes marques au {sup 14}C a partir de {sup 14}CO{sub 2} accelere dans un champ electrique - Analyse physico-chimique de quelques composes radioactifs obtenus; Proizvodstvo mechennykh uglerodom-14 soedinenij iz C{sup 14}O{sub 2}, uskorennogo v ehlektricheskom pole - Fiziko-khimicheskij analiz neskol'kikh poluchennykh radioaktivnykh soedinenij; Obtencion de compuestos marcados con {sup 14}C a partir de {sup 14}CO{sub 2} acelerado en un campo electrico - Analisis fisicoquimico de algunos de los compuestos radiactivos obtenidos

Energy Technology Data Exchange (ETDEWEB)

Guillaume, M [Universite de Liege, Belgique (Belgium)

1962-03-15

This paper describes a method of labelling which is based on the acceleration by an electric field of C{sup 14}O{sub 2}, which can then react with an organic target in its path. The discharge cell described operates at 500 Y, 150 {mu}A, and the organic products to be labelled are exposed to this field for about three hours with CO{sub 2} having a specific activity of 24mc/mmole. The maximum yield remains low (about 6%), and 60% of the C{sup 14}O{sub 2} is destroyed. This maximum activity is obtained only for aliphatic chains (50 {mu}c/g for glutaric acid) or for aromatic substances with an aliphatic chain (acetyl-salicylic acid). (author) [French] Le present memoire expose une methode de marquage basee sur l'acceleration par un champ electrique de {sup 14}CO{sub 2}, qui est alors susceptible d'entrer en reaction avec une cible organique se trouvant dans sa trajectoire. La cellule a decharge decrite fonctionne sous 500 V, 150 {mu}A, et les produits organiques a marquer sont soumis a ce champ pendant environ trois heures, avec du CO{sub 2} d'activite specifique 24 mc/mmole. Le rendement maximum obtenu reste faible (6% environ), et 60% du {sup 14}CO{sub 2} est detruit. Ce rendement maximum n'est obtenu que pour les chaines aliphatiques (50 {mu}c/g pour l'acide glutarique) ou pour des substances aromatiques presentant une chaine aliphatique (acide acetylsalicylique). (author) [Spanish] La memoria describe un metodo de marcacion que consiste en acelerar {sup 14}CO{sub 2} en un campo electrico para que pueda reaccionar con blancos constituidos por sustancias organicas colocadas en su trayectoria. La celda de descarga que describe la memoria funciona a 500 V y 150 {mu}A, y los productos organicos que se desean marcar se exponen al campo asi creado durante unas tres horas a CO{sub 2} de una actividad especifica de 24 mc/mmol. El rendimiento maximo obtenido es bajo (aproximadamente 6%) y el 60% del {sup 14}CO{sub 2} queda destruido. Este rendimiento maximo solo se alcanza con cadenas alifaticas (50 {mu}c/g para el acido glutarico) o con moleculas ciclicas que presenten una cadena alifatica (acido acetilsalicilico). (author) [Russian] V dannoj rabote izlagaetsya metod mecheniya, osnovannyj na uskorenii ehlektricheskim polem C{sup 14}O{sub 2}, kotoryj v ehto vremya poddaetsya vstupleniyu v reaktsiyu s organicheskoj mishen'yu, nakhodyashchejsya na ego traektorii. Opysyvaemaya razryadnaya kamera dejstvuet pod napryazheniem 500 v, 150 mka, a podlezhashchie mecheniyu organicheskie veshchestva vvodyatsya v ehto pole i nakhodyatsya tam okolo 3 chasov vmeste s CO{sub 2} udel'noj aktivnosti v 24 mkyuri/mmol'. Maksimal'nyj vykhod poluchennykh produktov ostaetsya slabym (okolo 6%), a 60% C{sup 14}O{sub 2} - razrusheno. EHtot maksimal'nyj vykhod poluchaetsya tol'ko dlya alifaticheskikh tsepej (50 mkkyuri/r dlya glutarovoj kisloty) ili dlya aromaticheskikh veshchestv, predstavlyayushchikh alifaticheskuyu tsep' (atsetilgalitsilovuyu kislotu). (author)

Identification of solution products of lanthanoid (3) diethyldithiocarbamatohexamethyl phosphotriamide compounds from IR, electron and sup 1 H, sup 13 C, sup 31 P NMR absorption spectra. Identifikatsiya produktov rastvoreniya diehtilditiokarbamatogeksametil fosfotriamidnykh soedinenij lantanoidov (3) po IK, ehlektronnym i YaMR sup 1 H, sup 13 C, sup 31 P spektram pogloshcheniya

Energy Technology Data Exchange (ETDEWEB)

Skopenko, V V; Savost' yanova, A F; Trachevskij, V V; Gorbalyuk, A D; Sukhan, T A [Kievskij Gosudarstvennyj Univ., Kiev (Ukrainian SSR)

1991-01-01

By the methods of conductometry, IR, electron and {sup 1}H, {sup 13}C, {sup 31}P NMR spectroscopy nonaqueous solutions of the compounds (La(S{sub 2}CNEt{sub 2})Hmpa{sub 5})(BPh{sub 4}){sub 2}, Hmpa=OP(NMe{sub 2}){sub 3}; (Ln(S{sub 2}CNEt{sub 2}){sub 2}Hmpa{sub 3})BPh{sub 4}, Ln=Y, La-Lu; (Ln(S{sub 2}CNEt{sub 2}){sub 3}Hmpa{sub 2}), Ln=La-Gd, have been investigated. It is ascertained that bis-dithiocarbamate compounds are dissolved in all the studied solvents with preservation of composition and structure of lanthanide (3) inner coordination sphere. Tris-dithiocarbamates in nonaqueous solutions are subjected to reactions of ligand redistribution according to schemes depending on the solvent nature. In the process of dissolving of lanthanum monodithiocarbamate bond isomerization of dithiocarbamate groups occurs, which is pronounced in splitting of {sup 1}H and {sup 13}C NMR signals.

Plutonium sorption to nanocast mesoporous carbon

Energy Technology Data Exchange (ETDEWEB)

Parsons-Moss, Tashi; Wang, Deborah; Jones, Stephen; Olive, Daniel; Nitsche, Heino [California Univ., Berkeley, CA (United States). Dept. of Chemistry; Lawrence Berkeley National Laboratory, Berkeley, CA (United States). Nuclear Science Div.; Tueysuez, Harun [Lawrence Berkeley National Laboratory, Berkeley, CA (United States). Nuclear Science Div.; Max-Planck-Institut fuer Kohlenforschung, Muelheim an der Ruhr (Germany)

2014-09-01

materials was measured to be at least 58 ± 5 mg {sup 239}Pu per g CMK carbon, compared to 12 ± 5 mg {sup 239}Pu per g activated carbon. The presence of EDTA in solution decreased the Pu sorption to CMK. Desorption from all samples occurred in 1 M HClO{sub 4}, usually within 24 h. The Pu interaction with the carbon surface was also probed via X-ray absorption spectroscopy (XAS) on the Pu L{sub III} absorption edge. Spectral fits of the X-ray absorption near-edge structure (XANES) data collected on both types of CMK samples showed that Pu(VI) was reduced to Pu(IV) at the carbon surface. The high affinity of mesoporous carbon for Pu, and the spontaneous reduction of Pu(VI) or Pu(V) to Pu(IV) at these carbon surfaces could be valuable for a variety of applications. (orig.)

Positron Scanning of Liver and Pancreas; Exploration de Foie et du Pancreas par les Positrons; Pozitronoskopiya pecheni i podzheludochnoj zhelezy; Exploracion del higado y del pancreas mediante positrones

Energy Technology Data Exchange (ETDEWEB)

Aronow, S; Thors, R; Brownell, G L [Physics Research Laboratory and Department of Surgery, Massachusetts General Hospital, Boston, MA (United States)

1959-07-01

para determinar el contorno del pancreas y del higado, respectivamente. Es singularmente dificil el problema de lograr una representacion visual del pancreas dado su reducido tamano y la presencia en su proximidad de organos de grandes dimensiones en los que el zinc se concentra. Los autores examinan diferentes procedimientos para abordar este problema. El cobre-64 en forma ionica sencilla y en forma de sal del acido etilendiaminotetra-acetico se concentra notablemente en el higado. Las exploraciones de ese organo mediante positrones parecen facilitar de modo considerable el diagnostico correcto de diferentes trastornos hepaticos. Los autores presentan datos sobre la distribucion de diferentes isotopos y compuestos en organismos animales. (author) [Russian] Uspeshnoe primenenie pozitronoskopi i v lokalizatsii mozgovykh opukholej vydvinulo ideyu o primenenii ehtogo tekhnicheskogo priema dlya analogichnykh tselej v lechenii drugikh organov. V obsledovaniyakh podzheludochno j zhelezy i pecheni ispol'zuyutsya sootvetstvenno Zn{sup 62} i Si{sup 64} v razlichnykh vida''. Vvidu obychno nebol'shogo razmera podzheludochno j zhelezy i nalichiya vblizi nee bol'shikh sosredotochivayushchi kh v sebe tsink organov problema obsledovaniya ee predstavlyaet osobye zatrudneniya. V dokumente rassmatrivayuts ya razlichnye sposoby resheniya ehtoj problemy. Kontsentratsiya v pecheni Si{sup 64} v prostom ionizirovanno m vide i v vide mednogo versenata dostigaet znachitel'nykh razmerov. Pozitronoskopi ya pecheni veroyatno pozvolit uspeshno provodit' diagnostiku razlichnykh narushenij deyatel'nosti pecheni. V dokumente privodyatsya dannye o raspredeleni i razlichnykh izotopov i khimicheskikh soedinenij v zhivykh organizmakh. (author)

Thermal And Gamma-Radiation Annealing Of The Iridium-192 Recoil Species In Crystalline Na{sub 2}IrCl{sub 6} {center_dot} 6H{sub 2}O; Recuit Thermique et par Rayonnement Gamma de l'espece {sup 192}Ir de Recul dans des Cristaux de Na{sub 2}IrCl{sub 6} * 6H{sub 2}O; 0422 0415 041f 041b 041e 0412 041e 0419 0418 0413 0410 041c 041c 0410 - 041e 0422 0416 0418 0413 041f 0420 041e 0414 0423 041a 0422 041e 0412 041e 0422 0414 0410 0427 0418 0418 0420 0418 0414 0418 042f -192 0412 041a 0420 0418 0421 0422 0410 041b 041b 0418 0427 0415 0421 041a 041e 041c Na{sub 2}IrCl{sub 6} {center_dot} 6H{sub 2}O; Regeneracion Termica y por Irradiacion Gamma de las Especies de Retroceso del Iridio-192 en Na{sub 2}IrCl{sub 6} {center_dot} 6H{sub 2}O Cristalino

Energy Technology Data Exchange (ETDEWEB)

Bell, Rita; Herr, W. [Kernforschungsanlage Juelich, Institut fuer Kernchemie der Universitaet Koeln, Cologne, Federal Republic of Germany (Germany)

1965-04-15

}IrCl{sub 6} * 6H{sub 2}O. Si bien la mayoria de ellos tienen caracter anionico, dos de ellos se comportan como cationes marcados con {sup 192}Ir. Los autores han estudiado el comportamiento de estos compuestos libres de portador frente a los agentes reductores y oxidantes y al envejecimiento en solucion. Investigaron independientemente la hidrolisis de los hexacloro complejos de iridio tri y tetravalente, que habian sido marcados con {sup 36}Cl y {sup 192}Ir. La comparacion entre las dos series de resultados, corroborada por otros datos obtenidos por activacion neutronica, permite identificar la mayor parte de los productos de retroceso como complejos octaedricos de Ir(III) que contienen ligandos Cl{sup -}, H{sub 2}O y OH{sup -} en distintas proporciones. Evidentemente, el agua de cristalizacion desempena un papel importante en la formacion de las especies de retroceso. La regeneracion termica de estos productos a 120 Degree-Sign C revela una rapida disminucion de los rendimientos de los acuocloro, hidroxicloro y acuohidroxicloro complejos y la formacion del compuesto precursor con excepcion del pentacloro complejo. La proporcion de este complejo disminuye unicamente despues de un aumento inicial, lo que indica que interviene como producto intermedio durante la regeneracion de otros productos. La regeneracion y presenta muchas fases separadas cuya tendencia general es una transicion de especies con un bajo contenido de Cl a otras con un elevado contenido de Cl, que conduce finalmente a un hexacloro complejo. Ello demuestra que el proceso de recocido consiste en la nueva penetracion de atomos (o iones) Cl en la esfera de ligandos, con el desplazamiento concomitante de H{sub 2}O y de OH (OH{sup -}). (author) [Russian] Imeetsja vozmozhnost' otdelenija posredstvom bumazhnogo jelektroforeza po krajnej mere 13 razlichnyh soedinenij otdachi, obrazujushhihsja Na{sub 2}IrCl{sub 6} * 6H{sub 2}O v rezul'tate jadernoj reakcii {sup 191}Ir (n, {gamma}) {sup 192}Ir. V to vremja kak

Effects of Temperature and Pressure on Hot-Atom Reactions in Bromoethane; Effets de la Temperature et de la Pression sur les Reactions des Atomes Chauds dans le Bromoethane; Vliyanie temperatury i davleniya na reaktsii goryachikh atomov v bromehtane; Efectos de la Temperatura y de la Presion en las Reacciones de Atomos Calientes en el Bromoetano

Energy Technology Data Exchange (ETDEWEB)

Cole, A. J.; Mia, M. D.; Miller, G. E.; Shaw, P. F.D. [Nuclear Physics Laboratory, Oxford University, Oxford (United Kingdom)

1965-04-15

-Sign C y a la presion atmosferica, asi como a 18 Degree-Sign C y presiones de hasta 10{sup 4} atm. Ademas de los compuestos ya conocidos en este sistema, se han hallado pequeflas cantidades de bromoetano, 1,2-dibromoetano, mono y dibromo- propanos y mono, di, tri y tetra bromobutanos; tambien hay pruebas indirectas de produccion debromobutenos. Las reacciones dependientes de la difusion son complejas, y se pueden explicar suponiendo que en las proximidades del atomo caliente se produce una pirolisis del liquido por la que se forman radicales bromo- etilo y etileno. La adicion de radicales a este ultimo determina la formacion de bromuros que contienen mas de dos atomos de carbono, asi como sus rendimientos dependientes de la difusion. La disminucion de la temperatura o el aumento de la presion se traduce por lo general en un incremento del rendimiento atribuible a una menor velocidad de difusion. El. efecto es mas acusado en el rendimiento de 1, 2-dibromoetano producido principalmente por la reaccion difusiva de radicales bromoetilo, que se cuadruplica al aplicar una presion de 10{sup 4} atm debido a la supresion de la disociacion CH{sub 2}-CH{sub 2}Br Rightwards-Arrow-Over-Leftwards-Arrow CH{sub 2} = CH{sub 2} + Br bajo la influencia de la ''punta termica''. En cambio, la disociacion del radical (CH{sub 3} -CHBr) en bromoetano y un atomo de hidrogeno no es energeticamente viable, y el rendimiento de 1,1-dibromoetano es casi independiente de la presion. La variacion del rendimiento de bromoetano para grandes concentraciones de bromo en funcion de la temperatura y de la presion se aproxima al valor que se habia previsto. (author) [Russian] Izuchalis' vyhody soedinenij, soderzhashhih Br{sup 80m} kotoryj byl poluchen oblucheniem smesej bromjetan-bromina nejtronami 14 Mjev pri temperaturah 18 Degree-Sign C, -80 Degree-Sign C i -115 Degree-Sign C pri atmosfernom davlenii, a takzhe pri 18 Degree-Sign C i davlenijah do 10{sup 4} atmosfer. Pomimo soedinenij jetoj sistemy

Sorption/Desorption Interactions of Plutonium with Montmorillonite

Science.gov (United States)

Begg, J.; Zavarin, M.; Zhao, P.; Kersting, A. B.

2012-12-01

first order process. Furthermore, a pH dependence was observed, with less desorbed at pH 4 compared to pH 8. We suggest the pH dependence is likely controlled by reoxidation of Pu(IV) to Pu(V) and aqueous speciation. We will present models used to describe desorption behavior and discuss the implications for Pu transport. References: Kersting, A.B.; Efurd, D.W.; Finnegan, D.L.; Rokop, D.J.; Smith, D.K.; Thompson J.L. (1999) Migration of plutonium in groundwater at the Nevada Test Site, Nature, 397, 56-59. Novikov A.P.; Kalmykov, S.N.; Utsunomiya, S.; Ewing, R.C.; Horreard, F.; Merkulov, A.; Clark, S.B.; Tkachev, V.V.; Myasoedov, B.F. (2006) Colloid transport of plutonium in the far-field of the Mayak Production Association, Russia, Science, 314, 638-641. Santschi, P.H.; Roberts, K.; Guo, L. (2002) The organic nature of colloidal actinides transported in surface water environments. Environ. Sci. Technol., 36, 3711-3719. This work was funded by U. S. DOE Office of Biological & Environmental Sciences, Subsurface Biogeochemistry Research Program, and performed under the auspices of the U. S. Department of Energy by Lawrence Livermore National Security, LLC under Contract DE-AC52-07NA27344. LLNL-ABS-570161

Speciation of plutonium during sorption and diffusion in Opalinus clay

International Nuclear Information System (INIS)

Kaplan, Ugras

2013-01-01

well as on OPA thin sections and diffusion samples. Pu L III -edge EXAFS spectra of powder samples showed that an innersphere sorption of Pu(IV) species on OPA surface was formed, independent from the initial Pu oxidation states in solution. By combining the applied spatially resolved methods, it was possible for the first time to determine the elemental distribution of Pu and other elements contained in OPA using μ-XRF. Pu L III -edge μ-XANES spectra on Pu hot spots of thin sections and diffusion samples confirmed that less mobile Pu(IV) is the dominating species on OPA after sorption and diffusion processes. In addition, for the first time a diffusion profile of Pu in OPA was measured using μ-XRF. The speciation of Pu with μ-XANES showed that Pu(V) was reduced progressively along its diffusion path to Pu(IV). By μ-XRD the clay mineral illite was identified as the main mineral phase in areas where Pu was enriched and iron(II)-bearing siderite could be one of the redox-active mineral phases contained in OPA. The results of this work show that OPA is a suitable option for the geological disposal with regard to the safety of a nuclear repository.

Treatment of solutions of fission products - Separation of caesium-137; Traitement des solutions de produits de fission - Separation du cesium-137; Obrabotka rastvorov produktov deleniya - Razdelenie tseziya-137; Tratamiento de soluciones de productos de fision - Separacion del cesio-137

Energy Technology Data Exchange (ETDEWEB)

Stiennon-Bovy, R [Centre d' Etude de l' Energie Nucleaire, Mol (Belgium); Gvion, R [Commission Israelienne de l' Energie Atomique, Tel-Aviv (Israel)

1962-01-15

appreciable de l'activite du cesium, sa realisation a la temperature ordinaire, et la possibilite d'exploitation en regime continu. Par ce procede, la recuperation du cesium peut etre faite avant l'elimination de certains produits de fission. (author) [Spanish] Los autores han adaptado el metodo analitico de determinacion del cesio por medio de la dipierilamina a la recuperacion en escala industrial del cesio-137 contenido en soluciones de productos de fision de elevada actividad. El procedimiento propuesto permite aislar el cesio en forma de cloruro en una sola operacion y recuperar el reactivo de precipitacion con facilidad. Los autores proponen un procedimiento basico. Han estudiado el efecto de las radiaciones sobre la dipierilamina y sus compuestos. Este efecto es practicamente nulo para los compuestos solidos, y despreciable para las soluciones. Ademas, los autores han estudiado el arrastre del cesio por el ion amonico. El procedimiento descrito presenta las ventajas siguientes: elevado grado de descontaminacion del cesio, sencillez del procedimiento y facilidad con que se puede recuperar y volver a emplear el reactivo, elevado rendimiento en la recuperacion del cesio y de la dipierilamina, concentracion apreciable de la actividad del cesio, posibilidad de trabajar a temperatura ambiente, posibilidad de trabajar en regimen continuo. Este procedimiento permite recuperar cesio antes de eliminar ciertos productos de fision. (author) [Russian] Dlya promyshlennogo izvlecheniya tseziya-137 iz rastvorov produktov deleniya avtory primenili analiticheskij sposob dozirovki tseziya pri pomoshchi dipikrilamina v promyshlennom masshtabe i s vysokimi aktivnostyami. Predlagaemyj sposob pozvolyaet odnoj operatsiej izolirovat' tsezij v vide khloristogo soedineniya i legko izvlech' reagent osadka. Avtory predlagayut printsipial'nuyu skhemu. Oni izuchili dejstvie izluchenij na dipikrilamin i ego soedineniya. EHto dejstvie okazyvaetsya prakticheski ravnym nulyu dlya tverdykh soedinenij i

Trace Analysis of Boron in Nuclear Graphite by Means of Gas Chromatography; Analyse de traces de bore dans le graphite nucleaire au moyen de la chromatographie gazeuse; Analiz metodom gazovoj khromatografii sledov bora v yadernom grafite; Analisis de vestigios de boro en el grafito nuclear por cromatografia de gases

Energy Technology Data Exchange (ETDEWEB)

Zado, F. [Rudjer Boskovlc Institute, Zagreb, Yugoslavia (Croatia)

1963-11-15

izgotovlena iz stekla s 20% w/w smazkoj iz ftorirovannykh uglevodorodov na kizel'gure. Prinimalis' spetsial'nye mery predostorozhnosti iz-za vlagochuvstvitel'nosti trekhkhloristykh soedinenij bora. (author)

Radioinitiation of Chain Branched Reactions and its Sensitization; Amorcage sous rayonnement des reactions par ramification en chaine; sensibilisation du processus; Radiatsionnoe initsiirovanie tsennykh razvetvlennykh reaktsij i ego sensibilizatsiya; Radioiniciacion de reacciones en cadena ramificadas y medios para aumentar su sensibilidad

Energy Technology Data Exchange (ETDEWEB)

Barelko, E V; Kartashova, L I; Komarov, P N; Proskurnin, M A [Karpov Physico-Chemical Institute, Moscow, Union of Soviet Socialist Republics (Russian Federation)

1960-07-15

fondamentales de la reaction d'oxydation par radiolyse du benzene : accumulation des divers produits de la reaction, action de la temperature, de la pression, de la puissance et de la dose d'irradiation sur le processus d'accumulation des produits de la reaction. Quelques conclusions sont exposees sur le mecanisme de la reaction. Les auteurs decrivent la construction de l'installation qui fonctionne en circuit ferme. (author) [Spanish] Figuran en esta memoria los resultados de los trabajos efectuados por los autores sobre la radioiniciacion de las reacciones de oxidacion de compuestos organicos en cadenas ramificadas. Se demuestra el papel que desempenan las radiaciones como agente de iniciacion, tomando como ejemplo la oxidacion del butanol y de varios hidrocarburos no saturados. La reaccion tiene caracter autoacelerador y prosigue espontaneamente al cesar la irradiacion. Se ha estudiado detalladamente el proceso de oxidacion del benceno, compuesto que se caracteriza por una elevada resistencia a las radiaciones. Los autores han ideado un metodo para sensibilizar la radioiniciacion de la oxidacion de compuestos radioresistentes por sustancias quimicamente inertes, pero inestables frente a las radiaciones. En la memoria se examinan los principales factores de que depende la radiooxidacion del benceno, a saber, concentracion de los distintos productos de reaccion e influencia de la temperatura, de la presion, de la energia y de la dosis de radiacion en el proceso de acumulacion de esos productos. Los autores formulan tambien algunas conclusiones sobre el mecanismo del proceso y describen la construccion de la instalacion de circulacion. (author) [Russian] V doklade predstavleny rezul'taty issledovanij avtorov po radiatsionnomu initsiirovaniyu tsepnykh razvetvlennykh reaktsij okisleniya organicheskikh soedinenij. Na primere okisleniya nekotorykh nenasyshchennykh uglevodorodov i butanola pokazana rol' izlucheniya kak initsiiruyushchego agenta. Reaktsiya imeet

Employment of the H{sup 3}-Progesterone in the Examination of the Synthesis of 17-OH-Corticosteroids by Human Placental Tissue; Emploi de la Progesterone Tritiee Pour L'etude de la Synthese des Steroiedes Surrenaux et Placentaires; 0418 0441 0414 ; Empleo de la Progesterone Tritiada en el Estudio de la Sintesis de Esteroides Suprarrenales y Placentarios

Energy Technology Data Exchange (ETDEWEB)

Polvani, F.; Roversi, G. D.; Silvestrini, R. [Clinica Ostetrica E Ginecologica dell' Universita di Milano Laboratorio di Microbiologia E Chemioterapia ' ' Farmitalia' ' , Milano (Italy)

1962-02-15

recemment obtenus. (author) [Spanish] Los autores han realizado estudios sobre la biosintesis de los esteroides suprarrenales y placentarios empleando progesterona marcada con tritio como precursor de los 17 hidroxicorticosteroides. Incubaron durante tres horas, en atmosfera de O{sub 2} , homogeneizados de capsulas suprarrenales de vacunos junto con progesterona tritiada. Seguidamente extrajeron los corticosteroides por el metodo de Meyer y los separaron por cromatografia en columna de Florisil, determinando los {Delta}-4-3-cetosteroides por cromatografia sobre papel. Sumergieron estas ultimas en una emulsion nuclear (Ilford K2 ''gel form'') y los mantuvieron durante 21 dias a 4 Degree-Sign C para lograr la identificacion de cortisona y Cortisol tritiados y de otros esteroides durante el proceso fotografico. Para los homogeneizados de placenta emplearon la misma tecnica que, con ayuda de un contador de gas, permitio detectar en las manchas del cromatograma la radiactividad de los 11-hidroxicorticoides de formacion reciente. (author) [Russian] Mechennyj tritiem progesteron ispol'zovalsja v ka- chestve prodromal'nogo faktora 17-ON-kortikosteroidov dlja izuchenija bio- sinteza placentnyh i adrenal'nyh steroidov. Gomogenaty iz nadpochechnika zhivotnyh vyderzhivalis' v termostate s {sup 3}N- progesteronom v atmosfere O{sub 2} v techenie treh chasov. Zatem izvlekalis' korti- kosteroidy po metodu Mejera i prigotavlivalis' hromatograficheski v florizi- lovyh kolonkah i na hromatograficheskoj bumage lokalizovalis' del'ta-4-3- ketosteroidy. Poslednjaja propityvalas' jadernoj jemul'siej (Ilford K 2 'forma gelja') i vyderzhivalas' pri temperature 4 Degree-Sign S v techenie 21 dnja, chto obespechivalo for- mirovanie {sup 3}N-kortizona, {sup 3}N-kortizola i drugih steroidal'nyh soedinenij, kogda stalo ochevidnym fotograficheskoe projavlenie. Podobnyj metod inkubacii ispol'zovalsja v issledovanijah placentnyh gomogenatov, kotorye obnaruzhivajut radioaktivnost' nedavno poluchennyh 11-ON

A study of the mechanism of certain heterogeneous catalytic processes using C{sup 14}-labelled compounds; Utilisation de composes marques au carbone-14 pour l'etude du mecanisme de certains processus catalytiques heterogenes; Issledovanie mekhanizma nekotorykh geterogenno-kataliticheskikh protsessov s primeneniem soedinenij, mechennykh uglerodom-14; Estudio del mecanismo de algunos procesos de catalisis heterogenea con ayuda de compuestos marcados con carbono-14

Energy Technology Data Exchange (ETDEWEB)

Isagulyants, G V; Balandin, A A

1962-03-15

An investigation is made of the method of calculating individual phase velocities for parallel, consecutive and parallel-consecutive reactions from kinetic data obtained by the use of labelled atoms. The method is used for calculating individual phase velocities in the decomposition reaction of isopropyl alcohol into vanadium trioxides, dehydrogenations of butane-butylene mixtures and dehydrations of ethyl alcohol. Compounds containing C{sup 14} were used in this study. (author) [French] Le memoire expose une methode par laquelle on calcule les vitesses a differents stades dans les reactions paralleles, consecutives et paralleles-consecutives en se servant de donnees cinetiques obtenues par l'utilisation d'atomes indicateurs. Cette methode est utilisee pour le calcul des vitesses a differents stades de la decomposition de l'alcool isopropylique par le trioxyde de vanadium, de la deshydrogenation des melanges butane-butylene et de la deshydratation de l'alcool ethylique. Pour ces travaux, on a utilise des composes contenant du carbone-14. (author) [Spanish] Se describe un metodo de calculo de las velocidades correspondientes a las distintas etapas de una serie de reacciones paralelas, consecutivas y paralelo-consecutivas, partiendo de datos cineticos obtenidos mediante atomos marcados. El metodo se aplica a la determinacion de las velocidades de las reacciones de descomposicion del alcohol isopropilico por el trioxido de vanadio, de deshidrogenacion de mezclas de butano y buteno y de deshidratacion del alcohol etilico. El trabajo se llevo a cabo con ayuda de compuestos marcados con carbono-14. (author) [Russian] Rassmotren metod rascheta skorostej otdel'nykh stadij dlya parallel'nykh, konsekutivnykh i parallel'no-konsekutivnykh reaktsij, iskhodya iz kineticheskikh dannykh, poluchennykh s primeneniem mechenykh atomov. Metod primenen k raschetu skorostej otdel'nykh stadij v reaktsii razlozheniya izopropilovogo spirta na trekhokisi vanadiya, degidrogenizatsii butan-butilenovykh smesej, degidratatsii ehtilovogo spirta. V rabote byli ispol'zovany soedineniya, soderzhashchie radiouglerod-14. (author)

Radionuclide release from research reactor spent fuel

Energy Technology Data Exchange (ETDEWEB)

Curtius, H., E-mail: h.curtius@fz-juelich.de [Forschungszentrum Juelich, Institut fuer Energieforschung, IEF-6 Sicherheitsforschung und Reaktortechnik, Geb. 05.3, D-52425 Juelich (Germany); Kaiser, G.; Mueller, E.; Bosbach, D. [Forschungszentrum Juelich, Institut fuer Energieforschung, IEF-6 Sicherheitsforschung und Reaktortechnik, Geb. 05.3, D-52425 Juelich (Germany)

2011-09-01

Numerous investigations with respect to LWR fuel under non oxidizing repository relevant conditions were performed. The results obtained indicate slow corrosion rates for the UO{sub 2} fuel matrix. Special fuel-types (mostly dispersed fuels, high enriched in {sup 235}U, cladded with aluminium) are used in German research reactors, whereas in German nuclear power plants, UO{sub 2}-fuel (LWR fuel, enrichment in {sup 235}U up to 5%, zircaloy as cladding) is used. Irradiated research reactor fuels contribute less than 1% to the total waste volume. In Germany, the state is responsible for fuel operation and for fuel back-end options. The institute for energy research (IEF-6) at the Research Center Juelich performs investigation with irradiated research reactor spent fuels under repository relevant conditions. In the study, the corrosion of research reactor spent fuel has been investigated in MgCl{sub 2}-rich salt brine and the radionuclide release fractions have been determined. Leaching experiments in brine with two different research reactor fuel-types were performed in a hot cell facility in order to determine the corrosion behaviour and the radionuclide release fractions. The corrosion of two dispersed research reactor fuel-types (UAl{sub x}-Al and U{sub 3}Si{sub 2}-Al) was studied in 400 mL MgCl{sub 2}-rich salt brine in the presence of Fe{sup 2+} under static and initially anoxic conditions. Within these experimental parameters, both fuel types corroded in the experimental time period of 3.5 years completely, and secondary alteration phases were formed. After complete corrosion of the used research reactor fuel samples, the inventories of Cs and Sr were quantitatively detected in solution. Solution concentrations of Am and Eu were lower than the solubility of Am(OH){sub 3}(s) and Eu(OH){sub 3}(s) solid phases respectively, and may be controlled by sorption processes. Pu concentrations may be controlled by Pu(IV) polymer species, but the presence of Pu(V) and Pu

Radiation Polymerization of Acetylene Hydrocarbons. Special Features; Particularites de la polymerisation radiochimique des hydrocarbures acetyleniques; Radiatsionnaya polimerizatsiya atsetilenovykh proizvodnykh; Particularidades de la radiopolimerizacion de los hidrocarburos acetilenicos

Energy Technology Data Exchange (ETDEWEB)

Barkalov, I. M.; Gol' danskij, V. I.; Go, Min' -Gao

1963-11-15

de la polimerizacion por radicales (v.g., velocidad de polimerizacion proporcional a la velocidad de iniciacion; energia de activacion muy pequefla; ausencia de inhibicion por el oxigeno). Sin embargo, se trata indudablemente de una polimerizacion por radicales. Los autores llegaron a esa conclusion al estudiar la iniciacion de la polimerizacion de hidrocarburos acetilenicos por compuestos que poseen caracteristicas de radicales, a saber, el peroxido de benzoilo y el dinitrilo del acido azoisobutirico. Estudiaron asi las propiedades cineticas y el mecanismo de degradacion del peroxido en presencia de hidrocarburos acetilenicos (v.g., fenilacetileno, deuterofenilacetileno y metilfenilacetileno). Tambien investigaron la cinetica de la copolimerizacion del fenilacetileno con diferentes monomeros vinilicos y la composicion de los copolimeros producidos a partir de distintas mezclas iniciales. Estos datos, juntamente con los resultados del estudio de la cinetica de la polimerizacion del fenilacetileno (usando benzoquinona como inhibidor) demuestran la escasa capacidad de reaccion del radical fenilacetilenico. La marcada desviacion con respecto a la ley de aditividad observada en la radiopolimerizacion en diversos disolventes, es indice de una considerable transferencia de energia a los hidrocarburos acetilenicos y sus polimeros. (author) [Russian] Sintez i issledovanie svojstv polimerov s sistemoj sopryazhennykh svyazej yavlyaetsya novym i ves'ma perspektivnym napravleniem v khimii vysokomolekulyarnykh soedinenij. Kharakternoj chertoj takikh polimernykh sistem yavlyaetsya bol'shaya stepen' delokalizatsii P-ehlektronov v makromolekule. Umen'shenie ehnergii vozbuzhdeniya v trepletnoe sostoyanie, ravno kak i ponizhenie potentsiala ionizatsii pri bol'shikh tsepyakh sopryazheniya, obuslavlivaet poluprovodnikovye i spetsificheskie magnitnye svojstva ehtikh soedinenij. Krome togo, ehti polimernye sistemy s sopryazhennymi svyazyami okazalis' ves'ma ehffektivnymi stabilizatorami

Application of radioisotopes to the investigation of the kinetics and mechanism of reactions of some inorganic complex compounds; Application des radioisotopes a l'etude de la cinetique et du mecanisme des reactions de certains complexes inorganiques; Primenenie radioizotopov k issledovaniyam kinetiki i mekhanizma reaktsij nekotorykh neorganicheskikh slozhnykh soedinenij; Aplicacion de los radioisotopos al estudio de la cinetica y del mecanismo de las reacciones de algunos complejos inorganicos

Energy Technology Data Exchange (ETDEWEB)

Harris, Gordon M [Department of Chemistry, University of Buffalo, Buffalo 14, NY (United States)

1962-03-15

Radioisotopes are invaluable tools in the study of many types of inorganic chemical reactions, particularly those involving complex ionic substances in aqueous solution. One important approach is through research on the rates and mechanisms of isotopic exchange processes. For example, a series of studies has been made of the exchange between carbon-14-labelled ''free'' carbonate and the ligand carbonate in octahedral complex ions of the type CoA{sub 2}CO{sub 3}{sup +}, where A = 2 NH{sub 3}, ethylenediamine (en), propylenediamine (pn), or trimethylenediamine (tn). These studies have led to a rather thorough understanding of the nature of this kind of ligand substitution reaction, and of the part played by the non-exchanging amine ligands in the process. Similar studies of oxalate exchange with tris-oxalato complexes of the form M (C{sub 2}O{sub 4}){sub 3}{sup -3}, where M = Co (III), Cr (III), or Rh (III), have been equally fruitful. An alternative technique, applicable only when using low-atomic-weight radioisotopes such as carbon-14, is to observe the equilibrium or kinetic isotope effects in the reaction of interest. I t has, for instance, been possible to interpret differences in the ligand carbonate exchange mechanism of Coen{sub 2}CO{sub 3}{sup +} and Cotn{sub 2}CO{sub 3}{sup +} on the basis of equilibrium isotope-effect measurements made on the carbonate exchange reaction. Similarly, data on the kinetic isotope effect in the acid-catalysed aquation of the Co (NH{sub 3}){sub 4}CO{sub 3}{sup +} ion has supported deductions as to the nature of the rate-determining bond-breakage step in such reactions. Finally, the mechanistic path of certain atoms or radicals in inorganic reactions, where a choice between alternative explanations must be made, is frequently facilitated by a radioactive tracer experiment. An example is the proof that cyanide does not appear as a rapidly exchanging intermediate in the oxidation of thiocyanate ion by hydrogen peroxide, although cyanide is an important end-product. (author) [French] Les radioisotopes sont particulierement precieux dans l'etude de nombreux types de reactions de chimie minerale, notamment de reactions ou interviennent des ions complexes en solution aqueuse. Les recherches sur la vitesse et le mecanisme des echanges isotopiques constituent un aspect important de ces applications. C'est ainsi qu'on a fait une serie d'etudes sur l'echange entre du carbonate ''libre'' marque au carbone-14 et le carbonate qui joue le role de coordinafc dans les ions complexes octaedriques du type CoA{sub 2}CO{sub 3}{sup +}, ou A represente le 2NH{sub 3}, ou l'ethylene-diamine (en), ou la propylene-diamine (pn) ou la trimethylene-diamine (tn). Grace aux etudes ainsi effectuees, on connait assez exactement la nature de ces reactions par substitution de coordinate, ainsi que le role joue par les coordinais amines qui ne participent pas a l'echange. Des etudes analogues sur l'echange entre oxalates dans les complexes tri-oxaliques de forme M (C{sub 2}O{sub 4}){sub 3}{sup 3-}, ou M=Co (III), Cr (III), ou Rh (III), n'ont pas ete moins fecondes en resultats. Une autre technique, applicable seulement lorsqu'on utilise des radioisotopes de faible poids atomique comme le carbone-14, consiste a observer les effets d'equilibre ou les effets cinetiques que les isotopes exercent sur la reaction etudiee. C'est ainsi qu'il a ete possible d'interpreter des differences dans le mecanisme d'echange du coordinat carbonate dans le Coen{sub 2}CO{sub 3}{sup +} et le Cotn{sub 2}CO{sub 3}{sup +}, par mesure de l'effet isotopique a l'etat d'equilibre dans la reaction d'echange des carbonates. De meme, des donnees sur l'effet isotopique cinetique dans l'hydratation avec catalyseur acide de l'ion Co(NH{sub 3}){sub 4}CO{sub 3}{sup +} ont confirme les deductions faites en ce qui concerne l'etape a laquelle se rompt la liaison, etape qui determine la vitesse de ces reactions. Enfin, la determination des positions successives de certains atomes ou radicaux, dans des reactions inorganiques pour lesquelles il faut choisir entre differentes explications, est souvent facilitee par l'emploi d'indicateurs radioactifs. C'est ainsi qu'on a pu prouver que le cyanure n'est pas un produit intermediaire qui subit un echange rapide dans l'oxydation de l'ion thiocyanate par le peroxyde d'hydrogene, quoique le cyanure soit un produit final important de la reaction. (author) [Spanish] Los radioisotopos constituyen medios auxiliares de incalculable valor para el estudio de muchos tipos de reacciones de la quimica inorganica, especialmente de aquellas en que intervienen iones complejos en solucion acuosa. Uno de sus aspectos mas importantes es la determinacion de las velocidades de reaccion y del mecanismo de los intercambios isotopicos. Por ejemplo, el autor ha realizado una serie de estudios sobre el intercambio entre carbonato ''libre'' marcado con carbono-14 y carbonato ligante en iones complejos octaedricos del tipo CoA{sub 2}CO{sub 3}{sup +}, donde A = 2NH{sub 3}, etilendiamina (en), propilendiamina (pn) o trimetilendiamina (tn). Estos estudios han permitido comprender a fondo la naturaleza de las reacciones de sustitucion de ligantes de este tipo y del papel que desempenan en el proceso los ligantes amino que no experimentan intercambio. Igualmente fructiferos han sido unos estudios analogos del intercambio de restos oxalato en complejos trioxalicos de formula M (C{sub 2}O{sub 4}){sub 3}{sup 3-}, en la que M = Co (III), Cr (III) o Rh (III). Otra tecnica, que puede aplicarse solamente cuando se emplean radioisotopos de bajo peso atomico, tales como el carbono-14, consiste en observar los efectos de equilibrio o los efectos cineticos que los isotopos ejercen sobre la reaccion. Como ejemplo, el autor ha logrado interpretar diferencias entre los mecanismos de intercambio de los restos carbonato ligantes entre el Coen{sub 2}CO{sub 3}{sup +} y el Cotn{sub 2}CO{sub 3}{sup +} por medicion del efecto isotopico, en estado de equilibrio, efectuada en la reaccion de intercambio de carbonatos. De la misma manera, los datos relativos al efecto cinetico de los isotopos en la hidratacion del ion Co(NH{sub 3}){sub 4}CO{sub 3}{sup +} catalizada por acidos han corroborado las teorias sobre el caracter de la fase de ruptura de enlaces, que determina la velocidad de estas reacciones. Por ultimo, los experimentos con trazadores radiactivos facilitan frecuentemente el estudio de las posiciones sucesivas de ciertos atomos o radicales en las reacciones inorganicas para las que existen diversas explicaciones teoricamente posibles. Como ejemplo puede citarse la demostracion de que en la oxidacion del ion tiocianato por peroxido de hidrogeno, el cianuro no es un producto intermedio que sufre un intercambio rapido a pesar de que constituye uno de los principales productos finales. (author) [Russian] Ispol'zovanie radioizotopov okazyvaet neotsenimye uslugi pri issledovanii khimicheskikh neorganicheskikh reaktsij samykh raznoobraznykh vidov i, v chastnosti, reaktsij so slozhnymi ionizirovannymi veshchestvami v vodnykh rastvorakh. Odnim iz vazhnykh metodov sluzhit izuchenie skorosti i mekhanizma protsessov izotopnogo obmena. Tak, naprimer, byl proveden ryad issledovanij obmen a mezhdu t.n. ''svobodnym'' karbonatom, mechennym uglerodom-14, i svyazyvayushchim karbonatom oktaehdral'nykh slozhnykh ionov tipa CoA{sub 2}CO{sub 3}{sup +}, gde A = 2 NH{sub 3}, ehtilendiamin (en), propilendiamin (pn) ili trimetilendiamin (tn). EHti issledovaniya priveli k dovol'no tochnomu ponimaniyu kharaktera reaktsij ehtogo roda po zamene svyazi, a takzhe roli v ehtoj reaktsii neuchastvuyushchikh v obmene svyazyvayushchikh aminovykh zven'ev. Analogichnye issledovaniya obmena oksalatov, provedennye so slozhnymi trioaksalatami tipa M (C{sub 2}O{sub 4}){sub 3}{sup -3}, gde M=Co (III), Cr (III) ili Br (III), dali stol' zhe plodotvornye rezul'taty. Drugim metodom, primenimym tol'ko v sluchae ispol'zovaniya radioizotopov s malym atomnym vesom, kak naprimer ugleroda-14, mozhet sluzhit' izuchenie v sootvetstvuyushchikh reaktsiyakh ravnovesiya ili kineticheskogo izotopnogo vozdejstviya. Tak, naprimer, na osnovanii izmereniya ravnovesiya vozdejstviya izotopov v reaktsiyakh obmena karbonatov predstavilos' vozmozhnym istolkovat' razlichie v mekhanizme obmena svyazyvayushchikh karbonatov Coen{sub 2}CO{sub 3}{sup +} i Cotn{sub 2}CO{sub 3}{sup +}. Podobnym zhe obrazom dannye o kineticheskom vozdejstvii izotopov pri kislotno-katalizirovannoj gidratatsii ionov Co (NH{sub 3}){sub 4}CO{sub 3}{sup +} podtverdili vyvody otnositel'no kharaktera ehtikh reaktsij v stadii razryva svyazi, opredelyayushchej skorost' reaktsij. Nakonets, opyty s primeneniem radioaktivnykh indikatorov chasto oblegchayut izuchenie traektorii nekotorykh atomov ili radikalov v neorganicheskikh reaktsiyakh, pri kotorykh prikhoditsya delat' vybor mezhdu dvumya vozmozhnymi ob{sup y}asneniyami. Primerom ehtogo mozhet sluzhit' dokazatel'stvo togo, chto, po-vidimomu, pri okislenii tiotsionatovykh ionov perekis'yu vodoroda tsianidy ne yavlyayutsya sredoj bystrogo obmena, khotya oni i yavlyayutsya vazhnym konechnym produktom. (author)

Research on the Primary Processes of Radiation-Initiated Polymerization; Recherches sur les processus primaires de polymerisation amorcee par rayonnements; Issledovaniya osnovnykh protsessov polimerizatsii pod vozdejstviem oblucheniya; Estudios sobre los procesos primarios en la polimerizacion radioinducida

Energy Technology Data Exchange (ETDEWEB)

Okamura, S; Manabe, T; Higashimura, T; Oishi, Y; Futami, S

1960-07-15

benzola razlichnym monomeram sleduyushchaya : sopryazhennye monomery > nesopryazhennye monomery > sootvetstvuyushchie predel'nye soedineniya. EHksperimenty s kvenchingom provodyatsya takzhe s ispol'zovaniem rastvorov polimerov v benzole. Poryadok otdachi sleduyushchij : natural'nyj kauchuk > polistirol > polivinilovaya sol' > akrilovye polimery. Rezul'taty, poluchennye dlya kvenchinga s pomoshch'yu sopolimera stirol-metil-metakrilata, ukazyvayut na to, chto osobaya sposobnost' k kvenchingu soedinenij stirola v sopolimere proyavlyaetsya v men'shej stepeni, chem v gomopolimere . Issledovalas' polimerizatsiya stirola v rastvorakh dvukhloristogo metilena pri nizkoj temperature. Poluchennye rezul'taty otnositel'no zavisimosti skorosti polimerizatsii ot intensivnosti soglasuyutsya s ionnym mekhanizmom. Sostav sopolimerov, poluchennykh s metil-metakrilatom, takzhe podtverzhdaet ehtot vyvod. (author)

Diffusion, recrystallization and phase transformations; Diffusion, recristallisation et changements de phase; Diffuziya, rekristallizatsiya i fazovye prevrashcheniya; Difusion, recristalizacion y cambios de fase

Energy Technology Data Exchange (ETDEWEB)

Bokshtejn, S Z; Gubareva, M A; Kishkin, S T; Moroz, L M

1962-01-15

rekristallizatsii, a takzhe posle polimorfnogo {alpha} {r_reversible} {gamma} prevrascheniya, atomy granits iskhodnykh zeren ne smeshchayutsya na znachitel'nye rasstoyaniya. Analogichno, atomy primesi (radioaktivnyj uglerod), raspolozhennye na granitsakh iskhodnogo zerna, ne perekhodyat na granitsy novykh zeren rekristallizovannogo metalla. V otlichie ot ehtogo plasticheskaya deformatsiya soprovozhdaetsya znachitel'nym peremeshcheniem atomov, raspolozhennykh na granitse zerna. Poluchennye dannye pokazyvayut, chto peremeshchenie granits zeren pri rekristallizatsii i pri posleduyushchem roste zeren svyazano s nekotorym spetsificheskim mekhanizmom, otlichnym ot obychnogo diffuzionnogo. Pokazano, chto strukturnye izmeneniya, protekayushchie v splavakh pri vysokikh temperaturakh, mogut izmenyat' skorost' protsessov samodiffuzii i geterodiffuzii. V rezul'tate issledovaniya diffuzionnykh protsessov v titane i ego splavakh v zavisimosti ot polimorfnogo sostoyaniya ustanovleno, chto skorost' protsessa v razlichnykh kristallicheskikh modifikatsiyakh titana sil'no otlichaetsya. EHtim snimaetsya sushchestvovavshee protivorechie mezhdu vysokoj temperaturoj plavleniya titana i otnositel'no nizkoj ehnergiej aktivatsii protsessa diffuzii v titane. (author)

Role of Exchange Equilibria in Structural Chemistry; Role des Equilibres d'Echange en Chimie Structurale; Rol' ravnovesiya obmena v strukturnoj khimii; Papel de los Equilibrios de Intercambio en Quimica Estructural

Energy Technology Data Exchange (ETDEWEB)

Van Wazer, J. R.; Moedritzer, K. [Monsanto Company, St. Louis, MI (United States)

1965-10-15

partes de estructuras moleculares. Ademas, se han estudiado cuantitativamente los equilibrios entre estructuras ciclicas y aciclicas. El hincapie que la quimica estructural hace sobre los compuestos del carbono (como lo pone de manifiesto la division de la'quimica descriptiva en las categorias e inorganica) se atribuye al hecho de ser sumamente lentas las reacciones de intercambio donde intervienen enlaces C-C o uniones entre carbono y cualquier otro atomo que no posea orbitales de enlace libres en niveles bajos (por ejemplo: Si, Ge, N, P, As, O, S, Se, F, Cl, Br). No obstante ello, hay vastos dominios de la quimica inorganica que no han podido describirse dado que las moleculas sufren reacciones de intercambio tan rapidas que resulta imposible separarlas. Sin embargo, se las puede identificar y valorar por metodos ffsicos (tales como la resonancia magnetica nuclear) con constantes de tiempo pequenas, a condicion de someter los datos obtenidos a un tratamiento matematico adecuado, siendo este tratamiento de una complejidad que justifica el empleo de una calculadora rapida [6,16]. Los topicos expuestos se ejemplifican [2, 12, 24, 28] mediante sistemas especificos seleccionados entre. los trabajos mas recientes del autor. Ademas de los estudios de equilibrio, se presta atencion a la cinetica [26, 27] de los procesos de intercambio. Se presentan varios teoremas generales que permiten predecir los tipos y cantidades de productos [6, 18]. (author) [Russian] Hotja v proshlom znachitel'- naja dolja usilij v oblasti reakcij obmena byla posvjashhena razboru monofunkcional'nyh zame- stitelej v polifunkcional'nom atome ili ego chasti, slozhnye molekuly mogut takzhe pod- vergat'sja obmenu chastej i davat' takim obrazom ravnovesnoe raspredelenie razlichnyh molekuljarnyh razmerov i form. Ispol'zovanie jadernogo magnitnogo rezonansa (JaMR) s vysokim razresheniem dlja issledovanija takih ravnovesnyh smesej slozhnyh soedinenij bylo opisano v 1964 i 1965 g g . vo mnogih dokladah

Economic wealth and soil erosion in new Citrus plantations in Eastern Spain or how to explain the Land Degradation

Science.gov (United States)

Giménez-Morera, Antonio; Cerdà, Artemio; Pereira, Pauloq

2014-05-01

higher than rainfed agriculture soil (García Orenes et al., 2009). Acknowledgements The research projects GL2008-02879/BTE, LEDDRA 243857 and RECARE FP7 project 603498 supported this research. References Bono, E. 2010. Naranja y desarrollo. La base agrícola exportadora de la economía del País Valenciano y el modelo de crecimiento hacea afuera. PUV, Valencia, 203 pp. Cerdà, A. 2001. Erosión hídrica del suelo en el Territorio Valenciano. El estado de la cuestión a través de la revisión bibliográfica. Geoforma Ediciones, Logroño, 79 pp. Cerdá, A. 2007. Soil water erosion on road embankments in Eastern Spain. Science of the Total Environments 378, 151-155. Cerdà, A., Morera, A.G., Bodí, M.B. 2009. Soil and water losses from new citrus orchards growing on sloped soils in the western Mediterranean basin. Earth Surface Processes and Landforms, 34 (13), 1822-1830. García-Orenes, F., Cerdà, A., Mataix-Solera, J., Guerrero, C., Bodí, M.B., Arcenegui, V., Zornoza, R. & Sempere, J.G. 2009. Effects of agricultural management on surface soil properties and soil-water losses in eastern Spain. Soil and Tillage Research, doi:10.1016/j.still.2009.06.002 Liu, Y., Tao, Y., Wan, K.Y., Zhang, G.S., Liu, D.B., Xiong, G.Y., Chen, F. 2012. Runoff and nutrient losses in citrus orchards on sloping land subjected to different surface mulching practices in the Danjiangkou Reservoir area of China. Agricultural Water Management, 110, 34-40. Wang, L., Tang, L., Wang, X., Chen, F. 2010. Effects of alley crop planting on soil and nutrient losses in the citrus orchards of the Three Gorges Region. Soil and Tillage Research, 110 (2), 243-250.

Physical Properties of P.V.C. Attenuated Network Copolymers Produced by Ionizing Radiation; Proprietes physiques des copolymeres obtenus sous l'action de rayonnements ionisants et dont le reseau est attenue par l'effet du chlorure de polyvinyle; Fizicheskie svojstva polivinilkhloridnykh obednennykh tsepej sopolimerov, poluchennykh v rezul'tate vozdejstviya ioniziruyushchej radiatsii; Propiedades fisicas de los copolimeros de redes atenuadas por cloruro de polivinilo obtenidos por irradiacion

Energy Technology Data Exchange (ETDEWEB)

Pinner, S H [Tube Investments Research Laboratories, Hinxton Hall, Cambridge (United Kingdom)

1960-07-15

perekrestnykh svyazej v polivinilkhloride s pomoshch'yu ioniziruyushchej radiatsii stavit osobye problemy. V svyazi s neblagopriyatnym obrazovaniem poperechnykh svyazej i parametrami razrusheniya svyazej dlya dannogo polimera dozy radiatsii, neobkhodimye dlya obrazovaniya prochnykh tsoperechnykh plotnostej soedinenij, yavlyayutsya slishkom bol'shimi i parallel'no s ehtim proiskhodit protsess obestsvechivaniya i degidrogalogenirovaniya. EHti trudnosti udalos' preodolet' putem vvedeniya diallilovykh i triallilovykh ehfirov v polivinilkhlorid eshche do oblucheniya. Takim obrazom udalos' poluchit' produkty s prochnymi poperechnymi svyazyami pri otnositel'no malykh dozakh ioniziruyushchej radiatsii. Proverka fizicheskikh svojstv dannykh produktov pokazyvaet, chto oni yavlyayutsya ne prostymi graft-sopolimerami, chto obychno svyazano s prisutstviem dlinnykh razvetvlennykh tsepej, a obednennymi allilovymi polimernymi svyazyami. V ehtikh materialakh sochetayutsya svojstva iskhodnogo polimera i allilovoj svyazi. V doklade govoritsya o prochnosti na razryv, module i rastyazhenii oslablennoj svyazi sopolimerov, kotorye rassmatrivayutsya v zavisimosti ot temperatury, kontsentratsii i roli allilovogo ehfira. Takzhe privodyatsya zamechaniya po stojkosti poluchennykh produktov k razbukhaniyu i k khimicheskomu vozdejstviyu. (author)

Retention of Radionuclides by Infants: I. Study Techniques and Error Evaluation; Retention des Radionucleides chez les Enfants en bas Age: I. Methodes de Recherche et Evaluation des Erreurs; 0417 0410 0414 ; Retencion de Radionuclidos en los Ninos de Pecho: I. Tecnicas de Estudio y Calculo del Error

Energy Technology Data Exchange (ETDEWEB)

Straub, C. P.; Kahn, B.; Wellman, H. N.; Telles, N. C.; Seltzer, R. A. [Radiological Health Research Activities, Robert A. Taft Sanitary Engineering Center, US Public Health Service, Department Of Health, Education and Welfare, Cincinnati, OH (United States)

1964-11-15

analizadas. Se ha preparado y utilizado un panal de papel especial con baja concentracion de estroncio estable. Se han calculado los valores de retencion para el calcio y el fosforo en el caso de 30 ninos. Las observaciones efectuadas demuestran que la retencion relativa de estroncio-90, referida al calcio, es mas elevada en los ninos que en los adultos. (author) [Russian] Nachinaja s 1960 goda provoditsja izmerenie stepeni zaderzhki radioizotopov i ustojchivyh himicheskih soedinenij u detej v vozraste ot 1 goda do 11 let. Za det'mi s so glasija roditelej velis' nabljudenija v sootvetstvujushhej domashnej srede, deti otbiralis' posle konsul'tacii s detskim vrachom, lechivshim rebenka, i vrachom laboratorii. Deti pitalis' gotovymi produktami ad lib opredelennogo kachestva i assortimenta. Pishhevye produkty, vdyhaemyj vozduh i voda, ispol'zuemye neposredstvenno i v processe podgotovki formuly, javljalis' istochnikom normal'nogo postuplenija v organizm izuchaemyh radioizotopov i ustojchivyh himicheskih soedinenij. Proizvodilsja'analiz obrazcov pishhevyh produktov, vody, ispol'zuemyh salfetok i bumagi. Vydelenija sobiralis' v podlezhashhie udaleniju salfetki, otdel'no mocha i kal. Opredeljalos' ili budet opredeljat'sja zaderzhka sledujushhih radioizotopov i ustojchivyh jelementov: stroncij-90, stroncij-89, cezij-137, radij-226, kal'cij, stroncij, fosfor i kalij. Jeti issledovanija znachitel'no otlichajutsja ot predydushhih. Radioizotopy i ustojchivye jelementy nahodilis' v obychnyh koncentracijah i v obychno vstrechajushhihsja himicheskih formah. Vozduh i voda, zagrjaznennye do urovnja okruzhajushhej sredy, i imejushhiesja v prodazhe pishhevye produkty javljalis' edinstvennym istochnikom pogloshhenija, poskol'ku nikakie radioizotopy i ustojchivye himicheskie soedinenija ne dobavljalis'. Issleduemye deti predstavljali soboj obychnyh zdorovyh (negospital'zirovannyh) detej v ih obychnoj domashnej srede. Osnovnye problemy pri provedenii jetih issledovanij zakljuchalis' v 1

Study of reactions of metals with sulphur and phosphorus compounds by pulsed temperatures; Etude des reactions entre metaux et composes du soufre et du phosphore au moyen de brusques hausses de temperature; Issledovanie reaktsii metallov s soedineniyami sery i fosfora pri regulyarnykh izmeneniyakh temperatury; Estudio de reacciones entre metales y compuestos de azufre y de fosforo empleando impulsos de temperatura

Energy Technology Data Exchange (ETDEWEB)

Campbell, R B; Grunberg, L [National Engineering Laboratory, East Kilbride, Glasgow (United Kingdom)

1962-01-15

, los autores han tenido en cuenta la estructura de los materiales empleados y los procesos de difusion a los que se debe el progreso de la reaccion una vez iniciada esta. (author) [Russian] Protivoiznosnoe dejstvie sernykh i fosfornykh soedinenij, kotorye obychno dobavlyayutsya k mashinnym maslam, zavisit ot khimicheskikh reaktsij s metallicheskimi poverkhnostyami shesterenok. EHti reaktsii imeyut mesto kak pri osnovnoj temperature masel (primerno 100 Degree-Sign C), tak i pri vysokikh temperaturakh (priblizitel'no 600 Degree-Sign C) v techenie nebol'shogo promezhutka vremeni, kogda zubtsy shesterenok vstupayut vo vzai-modejstvie pod nagruzkoj. Temperaturnye izmeneniya sozdavalis' v apparate, v kotorom korotkie impul'sy ehlektrotoka ispol'zovalis' dlya nagrevaniya metallicheskikh provodov, pogruzhennykh v mineral'noe maslo, soderzhashchee v rastvore mechenye soedineniya sery-35 i fosfora-32. Zameryalas' voznikavshaya v provodakh radioaktivnost'. Stepen' reaktsii opredelyalas' kak funktsiya temperatury i vremeni. Rezul'taty reaktsii vyrazhalis' posredstvom osnovnykh zakonov kinetiki. Izucheniyu podverglis' voprosy izmeneniya skorosti reaktsii v zavisimosti ot nalichiya drugikh sostavov v rastvore. Bylo takzhe opredeleno vliyanie predvaritel'no obrazovannykh pokrytij poverkhnosti, soderzhashchikh seru, fosfor, khlor i/ili kislorod. Dlya ob{sup y}asneniya rezul'tatov raboty ispol'zuyutsya dannye o strukture materialov, a takzhe rassmatrivayutsya protsessy diffuzij tam, gde reaktsii vykhodili za svoi nachal'nye stadii. (author)

Optimization of Gamma-Ray Counting and Spectrometry in Biomedical Tracer Studies; Optimisation du Comptage et de la Spectrometrie des Rayons Gamma dans des Etudes Biomedicales Faites a l'Aide de Traceurs; Optimizatsiya gamma-scheta i spektrometrii gamma-luchej v biomeditsinskikh issledovaniyakh s pomoshch'yu indikatorov; Optimizacion del Recuento y de la Espectrometry Gamma en los Estudios Biomedicos con Indicadores

Energy Technology Data Exchange (ETDEWEB)

Guinn, V. P. [General Dynamics Corporation, San Diego, CA (United States)

1965-10-15

de recuento se ha calculado la actividad especifica minima detectable de la muestra, asi como los niveles requeridos para las precisiones estadfsticas (expresadas como desviaciones tipo) de {+-} 20%, {+-} 10%, {+-} 5% y {+-}2% En varios casos se han comparado los limites calculados con valores experimentales. Se ha prestado especial atencion a las mejores condiciones para reducir al mfnimo las contribuciones de los rayos X generados en el plomo, de los rayos gamma retrodispersos, de los maximos de escape, de las particulas beta de las muestras y de las radiaciones de frenado. (author) [Russian] V biomedicinskih issledovanijah s pomoshh'ju indikatorov, osobenno ljudej i, tem bolee, detej i beremennyh zhenshhin, vazhno rabotat' pri naimenee nizkom urovne vvodimyh radioizotopov, naskol'ko jeto sovmestimo s trebuemoj tochnost'ju i pravil'nost'ju posledujushhih izmerenij radioaktivnosti. Analo- gichnym obrazom, v sluchae vvedenija v organizm stabil'nyh jelementov (v vide opredelennyh soedinenij) ili obogashhennyh stabil'nyh izotopov (opjat'-taki v vide soedinenij) dlja dal'- nejshego radioaktivacionnogo analiza poluchennyh prob, s tochki zrenija toksikologii vazhno sokrashhat' do minimuma kolichestvo vvodimogo jelementa. V laboratorijah byla tshhatel'no izuchena problema optimizacii otschityvanija odnogo, dvuh n treh gamma-izluchajushhih radioizotopov pri pomoshhi scintilljacionnyh schetchikov s kristallom NaJ(Tl), odnokanal'noj i mnogokanal'noj spektrometrii, prichem osoboe vni- manie udeljalos' issledovanijam pri pomoshhi mechenija odnim, dvumja ili tremja indikatorami, naibolee chasto ispol'zuemymi v bnomedicinskih issledovanijah, a imenno: hrom-51, zoloto-198, selen-75, rtut'-197, med'-64, mysh'jak-76, brom-82, zhelezo-59, kobal't-60, kal'cij-42 i natrij-24. Odinakovye soobrazhenija otnosjatsja k opredeleniju pri pomoshhi shiroko ispol'zuemogo aktivacionnogo analiza teplovymi nejtronami sootvetstvujushhih jelementov ili obogashhennyh stabil'nyh izotopov, tak chto

Uptake, retention and excretion of strontium in man; Assimilation, retention et excretion du strontium chez l'homme; Pogloshchenie, zaderzhka i vydelenie strontsiya organizmom cheloveka; Absorcion, retencion y excrecion del estroncio en el hombre

Energy Technology Data Exchange (ETDEWEB)

Harrison, G. E. [Radiobiological Research Unit, Medical Research Council, Harwell (United Kingdom)

1963-02-15

estroncio en el esqueleto y sugiere que existen por lo menos tres grados de fijacion del estroncio radiactivo en los huesos. Estudia particularmente la retencion despues de varios meses de aplicada la dosis y la relacion existente entre esta retencion y la dosis de radiacion de {sup 90}Sr recibida por el esqueleto. Propone por ultimo una formula para evaluar la retencion en el organismo de una dosis de estroncio radiactivo a partir del valor de la radiactividad excretada con la orina. (author) [Russian] Obsuzhdaetsya vopros o vsasyvanii strontsiya iz zheludochno-kishechnogo trakta v svyazi s dietoj i razlichnymi komponentami khlebnomolochnoj diety. Privodyatsya rezul'taty, poluchennye pri ispol'zovanii kompleksnykh soedinenij, i diety s vysokim soderzhaniem kal'tsiya dlya umen'sheniya pogloshcheniya strontsiya. Obsutdaetsya sootnoshenie strontsiya i kal'tsiya v razlichnykh chastyakh tela u vzroslogo cheloveka. Privodyatsya rezul'taty nedavnikh ehksperimental'nykh issledovanij, provedennykh u zdorovykh lyudej na postoyannoj diete, pri ehtom osoboe vnimanie udelyaetsya vydeleniyu s mochoj i zaderzhke strontsiya-85, soderzhashchegosya v ehksperimental'noj diete. Opredelyalos' takzhe ehndogennoe vydelenie s ehkskrementami. Ehti dannye sravnivayutsya s rezul'tatami, poluchennymi pri odnokratnom vnutrivennom vvedenii radioaktivnogo strontsiya. Vo vsekh sluchayakh uderzhanie strontsiya opoedelyalos' izmereniem radioaktivnosti vsego organizma s pomoshch'yu amplitudnogo analizatora impul'sov. Analiziruyutsya prichiny ehaderkhki strontsiya a' skelete i postiliruetsya, chto imeyutsya, po krajnej meretri stepeni svyazi radioaktivnogo strontsiya s kostyami. Obsukhdaetsya, v chastnosti, zaderkhka izotopa v techenie neskol'kikh mesyatsev posle ego vvedeniya, a tayue svyaz' ehtoj zaderzhki s dozoj oblucheniya, poluchaemoj skeletom ot strontsiya-90. Predlagaetsya formula dlya opredeleniya uderzhaniya organizmom radioaktivnoj dozy strontsiya v zavisimosti ot radioaktivnosti, vydelyaemoj s

Non-Destructive Examination of the Heat-Affected Zone of Welded Zr-Nb Alloy; Controle Non Destructif de la Zone d'Un Alliage Zr-Nb Affectee par la Chaleur Lors du Soudage; Nedestruktivnoe ispytanie zony svarnogo shva iz tsirkonij-niobij splava, kotoryj podverzhen teplovomu vliyaniyu; Examen No Destructivo de la Zona de Soldadura Afectada por el Calor en las Aleaciones de Circonio y Niobio

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Hanstock, R. F.; Walker, D. C.B. [U.K.A.E.A. Reactor Materials Laboratory, Culcheth (United Kingdom)

1965-10-15

sencilla modificacion, para examinar las soldaduras en las aleaciones de circonio y niobio. Se da un ejemplo de las variaciones en la respuesta de la sonda en las distintas partes de una soldadura afectadas por el calor, y se las compara con los resultados del estudio de la corrosion efectuado en autoclave. (author) [Russian] Ispol'zovanie splava iz cir- konija i 2,5% niobija dlja obolochki vysokogo davlenija v reaktorah s vodnym zamedlitelem imeet rjad preimushhestv, svjazannyh s prochnost'ju je t ogo splava blagodarja termoobrabotke. Termoobrabotka takzhe chuvstvitel'no vlijaet na korrozionnuju stojkost' splava v uslovijah raboty reaktora, i v zonah svarki plavleniem, kotorye podverzheny teplovomu vlijaniju, mogut pojavit'sja zony nizkoj korrozionnoj stojkosti. Zony, podverzhennye korrozii, mozhno usta- novit' putem obrabotki v avtoklave. Odnako je tot metod javljaetsja neudobnym v teh slucha- jah, kogda putem svarki sobirajutsja krupnogabaritnye kontury vysokogo davlenija. Prishli k vyvodu, chto zony teplovogo vozdejstvija, chuvstvitel'nye k korrozii, mozhno obnaruzhit' putem izmerenija termojelektricheskogo potenciala mezhdu nagretym metallicheskim tochech- nym zondom, kontaktirujushhimsja s opredelennymi oblastjami svarnogo shva, i primykajushhim k nemu metallom. Termojelektricheskij zond izgotavlivaetsja tak zhe, kak zond, kotoryj soz - dan Britanskoj associaciej po issledovanijam cvetnyh metallov dlja izmerenija tolshhiny pokrytija metallicheskih substratov. Imejushhijsja v prodazhe pribor, kotoryj vkljuchaet takoj zond s neznachitel'nymi vidoizmenenijami, mozhno ispol'zovat' dlja ispytanija svarnyh soedinenij iz cirkonij-niobij splavov. Privoditsja primer izmenenija zondovoj chuvstvitel'- nosti po zonam svarnogo shva, podverzhennym teplovomu vozdejstviju, i jet ot primer srav- nivaetsja s provedennym v avtoklave ispytaniem na korroziju. (author)

Analysis of the Volatile Constituents of Irradiated Apple Juice; Analyse des Constituants Volatils des Jus de Pommes Irradies; Mezhdunarodnyj proekt po oblucheniyu fruktov i fruktovykh sokov; Analisis de los Componentes Volatiles de los Zumos de Manzana Irradiados

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Dubois, P.; Zenz, H.; Stehlik, G.; Kaindl, K. [Agence Europeenne pour l' Energie Nucleaire, Seibersdorf (Austria)

1966-11-15

sootvetstvujushhij emu na hromatogrammah pik polnost'ju pokryvaetsja pikom jetanola, kogda rech' idet o nekoj- centrirovannyh sokah. Byli obnaruzheny k tomu zhe obrazovanija furana i dvuh soedinenij, kotorye pojavljajutsja tol'ko v vide sledov i kotorye ne byli opredeleny do nastojashhego vremeni. Poluchennye rezul'taty byli analogichny tem, chto i pri pasterizacii putem nagrevanija. (author)

Rare-Earth-Rich Alloys; Alliages a Teneur Elevee en Terres Rares; Splavy, obogashchennye redkozemel'nymi ehlementami; Aleaciones Ricas en Tierras Raras

Energy Technology Data Exchange (ETDEWEB)

Copeland, M.; Kato, H. [Albany Metallurgy Research Center, Bureau of Mines, United States Department of the Interior, Albany, OR (United States)

1964-06-15

solubilidad solida del metal aleado con la tierra rara y estudiaron la oxidacion y la corrosion. Los autores no observaron ningun aumento de la resistencia a la oxidacion en la atmosfera que pudiera atribuirse a la aleacion; es mas, la mayor parte de las adiciones ejercieron efectos nocivos. El aluminio mejoro notablemente la resistencia a la corrosion en agua caliente de las tierras raras sometidas a ensayo; la adicion de otros metales no pertenecientes al grupo de las tierras raras tambien aumento esa resistencia, pero en menor grado. (author) [Russian] Redkozemel'nye metally s vysokim secheniem zahvata teplovyh nejtronov predstavljajut interes dlja upravlenija reaktorami, proizvodjashhimi jelektrojenergiju; odnako oni podverzheny korrozii. I s hodja iz toj predposylki, chto neredkozemel'nye metally mogut byt' splavleny s disproziem, orbiem, gadoliniem i samariem i mogut uluchshit' ih svojstva, izucheny vlijanija redkozemel'nyh metallov opredelennyh dobavok ih na splavy. Izuchena rastvorimost' n e redkozemel'nyh metallov cirkonija, vanadija, hroma, zheleza, nikelja, medi, aljuminija i kremnija v disprozii, jerbii, gadolinii i samarii, a takzhe ih vlijanie na tochki plavlenija, preobrazovanie v tverdoe telo i korrozijnye svojstva. Podgotovleny diagrammy faz vplot' do pervyh soedinenij, obogashhennyh redkozemel'nymi jelementami ili jevtetik, kotorye voznikli vpervye. Po zavershenii jetoj chasti raboty byli sozdany splavy, obrabotany pri vysokoj temperature s cel'ju poluchenija maksimal'noj rastvorimosti tverdyh neredkozemel'nyh jelementov, dobavljaemyh dlja splava, i byli provedeny ispytanija na okislenie i korroziju. Pri splavlenii ne nabljudalos' uluchshenija redkozemel'nyh metallov v otnoshenii stojkosti k okisleniju na vozduhe, i fakticheski v bol'shinstve dobavki okazalis' vrednymi. Aljuminij v znachitel'noj stepeni uluchshil soprotivljaemost' k korrozii ot gorjachej vody v aprobirovannyh redkozemel'nyh jelementah; drugie neredkozemel'nye metally pri dobavkah uluchshili

Radiochemical Determination of Plutonium for Radiological Purposes; Determination Radiochimique du Plutonium a des Fins Radiologiques; Radiokhimicheskoe opredelenie plutoniya dlya tselej radiologii; Determinacion Radioquimica del Plutonio con Fines Radiologicos

Energy Technology Data Exchange (ETDEWEB)

Nielsen, J. M.; Beasley, T. M. [Chemical Laboratory, Hanford Laboratories, General Electric Company, Richland, WA (United States)

1964-10-15

, kostej, tkanej i rastitel'nosti, prichem podcherkivaetsja neobhodimost' izbegat' obrazovanija tugoplavkih plohorastvorimyh soedinenij plutonija. Rassmatrivajutsja analiticheskie metody opredelenija plutonija v jetih materialah, kotorye vkljuchajut sovmestnoe osazhdenie, jekstragirovanie zhidkost'-zhidkost', ionno-obmennuju hromatografiju i ispol'zovanie izotopov plutonija dlja konechnyh opredelenij posredstvom analizov al'fa-jenergii. Posredstvom schetno-vychislitel'noj statistiki proizvedeno sravnenie imejushhejsja chuvstvitel'nosti v vychislenii nizkih urovnej al'fa-scheta s pomoshh'ju ionizacionnoj kamery, proporcional'nyh schetchikov, diodnyh schetchikov i jemul'sii s jadernoj metkoj. Metody izotopnogo analiza plutonija s pomoshh'ju al'fa-spektrometrii, metodov jadernoj jemul'sii i zhidkostnyh scintil- ljacionnyh schetchikov takzhe vkljucheny v jetot dokument. Ispol'zovanie neizotopnyh nositelej v kachestve istochnika postoronnej aktivnosti i urovni soderzhanija plutonija v okruzhajushhej srede, nedavno obnaruzhennye na zemnom share, obsuzhdajutsja v svjazi s kontrol'nymi obrazcami. Dlja budushhih metodov analiza plutonija rassmatrivajutsja dve vozmozhnosti, gde trebuetsja povyshennaja chuvstvitel'nost'. Jetimi vozmozhnostjami javljajutsja aktivacionnyj analiz i podschet produktov raspada. (author)

The Formation of Polymeric Products in Reactions of Polyvalent Recoil Atoms; Formation de Polymeres lors de Reactions Provoquees par des Atomes de Recul Polyvalents; Obrazovanie polimernykh produktov pri reaktsiyakh polivalentnykh atomov otdachi; Formacion de Polimeros en las Reacciones de Atomos de Retroceso Polivalentes

Energy Technology Data Exchange (ETDEWEB)

Dzantiev, B. G.; Stukan, R. A.; Shvedchikov, A. P.; Shishkov, A. V. [Institut Himicheskoj Fiziki AN SSSR, Moskva, SSSR (Russian Federation)

1965-04-15

mechenyh polimernyh produktov v processe himicheskoj stabilizacii atomov otdachi sery-35 i ugleroda-14, poluchajushhihsja po jadernym reakcijam Cl{sup 35} /n, p/S{sup 35} i N{sup 14}/n, p/C{sup 14} v gazovoj i zhidkoj fazah. Mozhno predpolozhit', chto v processe stabilizacii gorjachie atomy ugleroda obrazujut metilenovye biradikaly, kotorye po svoej sposobnosti vstupat' v reakciju vo mnogom napominajut povedenie atomarnoj sery. Issledovanija provodilis' kak dlja parafinovyh (CH{sub 4}, C{sub 2}H{sub 6}), tak i dlja ciklicheskih (ciklogeksan, ciklogeksen, benzol) uglevodorod. Oblucheniju podvergalis' binarnye sistemy uglevodorod-datchik gorjachih atomov S{sup 35} i C{sup 14}. V kachestve poslednego ispol'zovalis' soedinenija CCI{sub 4}, HCl i ammiak. Obluchenie provodilos' na reaktore tipa IRT-1000 pri potoke teplovyh nejtronov 10{sup 11} - 10{sup 12} neJtron/cm{sup 2}sek. Pokazano, chto dlja razlichnyh soedinenij v zhidkoj faze do 60-90% sery-35 stabilizuetsja v forme polimera, vyhod kotorogo jekstremal'no zavisit ot sostava, prohodja cherez maksimum pri sootnoshenii komponentov, blizkom k jekvimolekuljarnomu. V gazovoj faze vyhod polimera sostavljaet 30 - 40% ot obshhej aktivnosti. Metodom radiohromatografii na bumage ustanovleno, chto mechenye polimernye produkty imejut slozhnyj sostav i predstavljajut soboj smes' dvuh kachestvenno otlichnyh tipov soedinenij, vyhod kotoryh po-raznomu menjaetsja v zavisimosti ot sootnoshenija komponentov. Uvelichenie vremeni obluchenija privodit k rostu vyhoda mechenogo polimera. V sluchae zhidkofaznoj sistemy C{sub 6}H{sub 12}-CCl{sub 4} molekuljarnyj ves S{sup 35}-soderzhashhego polimera, opredeljalsja metodom diffuzii iz kapilljara i okazalsja ravnym 5000 dlja polimera odnogo tipa i 500 - 1000 dlja drugogo. Obrazovanie vysokokipjashhego mechenogo produkta nabljudalos' takzhe pri obluchenii chistogo CCI{sub 4}. Analogichnye opyty provodilis' v sisteme jetilen -ammiak v gazovoj faze pri vysokom davlenii. Pokazano, chto v jetom sluchae

Theoretical Aspects of Phonon Dispersion Curves for Metals; Aspects Theoriques des Courbes de Dispersion des Phonons pour les Metaux; Teoreticheskie aspekty fononnykh dispersionnykh krivykh dlya metallov; Aspectos Teoricos de las Curvas de Dispersion Fononica en Metales

Energy Technology Data Exchange (ETDEWEB)

Cochran, W. [Department of Natural Philosophy, University of Edinburgh, Scotland (United Kingdom)

1965-04-15

, manifiestan la presencia de fuerzas de alcance relativamente grande, que se extienden a varios espacios interatomicos. Los resultados relativos al plomo son particularmente interesantes; no fue posible ajustarlos a un modelo de constantes de fuerza, pero las curvas de dispersion de los vectores de onda en las direcciones de simetria, analizadas en funcion de las constantes de fuerza entre planos atomicos, revelan la existencia de un potencial interatomico de caracter oscilatorio que se extiende a distancias superiores a 20A. La memoria trata de trabajos teoricos recientes, relacionados con el calculo de las curvas de dispersion fononica en metales y con la explicacion del largo alcance del potencial interatomico. En la actualidad, el metodo mas prometedor para abordar con criterio general la interaccion atomica en los metales parece ser el de los 'pseudoatomos neutros ', denominacion recientemente acunada por Ziman. Se exponen los principios de esta teoria de Aproximacion y se examina su relacion con las anomalias de Kohn en las curvas de dispersion fononica. En el caso del sodio, los valores experimentales concuerdan con los datos teoricos, y el potencial interatomico varia periodicamente en la distancia {pi}/k{sub F}, donde hk{sub F} es el momento de Fermi, como ha demostrado Koenig por un procedimiento diferente. Toya y Sham han realizado calculos mas exactos para el sodio; se examinan las relaciones existentes entre los diferentes metodos y otros trabajos de indole mas general, tales como los de Harrison. (author) [Russian] V nastojashhee vremja v rezul'tate jeksperimentov po neuprugomu rassejaniju nejtronov dovol'no polno izucheny fononnye dispersionnye krivye po krajnej mere dlja djuzhiny metallicheskih jelementov i intermetallicheskih soedinenij. Rezul'taty imejut odnu obshhuju oso- oennost': analiz ih s tochki zrenija konstant mezhatomnyh sil pokazyvaet nalichie dovol'no dal'nodejstvujushhih sil, prostirajushhihsja na neskol'ko mezhatomnyh rasstojanij. Osobyj interes

Technical Developments in the USAEC Process Radiation Development Program; Etudes technologiques dans le cadre du programme de mise au point d'applications industrielles des rayonnements de la CEA-EU; Issledovaniya v oblasti promyshlennogo primeneniya izluchenij, vkhodyashchie v programmu komissii po atomnoj ehnergii USAEC; Progresos tecnicos en el programa de la USAEC para el fomento de la irradiacion industrial

Energy Technology Data Exchange (ETDEWEB)

Machurek, J. E.; Stein, M. H. [Division of Isotopes Development, USAEC, Washington, DC (United States)

1963-11-15

ispol'zovanie ioniziruyushchikh izluchenij v promyshlennosti. Provedeno chetyrnadtsat' takikh issledovanij, rezul'taty nekotorykh iz nikh izlozheny v obshchikh chertakh v dannoj rabote, ostal'nye izlagayutsya bolee podrobno - v drugikh stat'yakh trudov. Temy issledovanij vklyuchayut: 1. Prigotovlenie kombinatsij derevo-plastik, ispol'zuya gamma-izluchenie dlya indutsirovaniya polimerizatsii. 2. Ispol'zovanie beta-izlucheniya produktov deleniya dlya gidrogenizatsii uglya, i ego produktov s tsel'yu polucheniya zhidkogo uglevodorodnogo topliva. 3. Poluchenie poluprovodnikovykh priborov s formirovaniem zadannogo prostranstvennogo raspredeleniya primesej v zavisimosti ot legirovaniya putem nejtronnykh prevrashchenij. 4. Vyzvannaya izlucheniem polimerizatsiya ehtilena i sopolimerov. 5. Osnovnye issledovaniya mekhanizmov i kinetiki reaktsij, vyzvannykh izlucheniem. 6. Radiatsionno-khimicheskie protsessy pri ftorirovanii razlichnykh aromaticheskikh soedinenij. 7. Ispol'zovanie polifunktsional'nykh monomerov dlya intensifikatsii radiatsionnogo sshivaniya poliehtilena, polipropilena, poliizobutilena i atsetattsellyulozy. 8. Vliyanie nabukhaniya, deformatsii i temperatury na fizicheskie i khimicheskie svojstva polimerov, poluchennykh s pomoshch'yu radiatsii. 9. Vliyanie strukturnykh faktorov na radiatsionnye izmeneniya v polimerakh, privodyashchie k graftsopolimerizatsii. 10. Ispol'zovanie yadernykh izluchenij dlya modifikatstsii tekstil'nykh materialov. 11. Reaktsii, vyzvannye izlucheniem kriptona-85. 12. Podgotovka ''Spravochnika po radiatsii''. 13. Ispol'zovanie metalloorganicheskoj svyazi dlya gamma-dozimetrii pri bol'shikh moshchnostyakh dozy. 14. Razrabotka dozimetra s solnechnym ehlementom. (author)

The use of radioactive tracers in lubrication and wear research; Emploi des indicateurs radioactifs dans les recherches sur la lubrification et l'usure; Ispol'zovanie mechenykh atomov pri issledovanii voprosov smazki i iznosa; Utilizacion de los indicadores radiactivos en los estudios sobre la lubricacion y el desgaste

Energy Technology Data Exchange (ETDEWEB)

Campbell, R B; Grunberg, L; Milne, A A; Wright, K H.R. [Lubrication, Wear and Mechanical Engineering Aspects of Corrosion Division, National Engineering Laboratory, Thorntonhall, Glasgow (United Kingdom)

1962-01-15

chastitsy okisi zheleza ispol'zuyutsya dlya izucheniya ikh roli v protsesse iznosa. Reaktivnost' poverkh- nosti zakalennykh metallov izuchalas' s pomoshch'yu mechennoj uglerodom-14 stearinovoj kisloty i rastvora sery-35. Skorost' reaktsii v primesi masla dlya shesteren analizirovalas' putem propuskaniya korotkikh impul'sov ehlektrotoka po metallicheskim provodam, opushchennym v rastvory soedinenij, mechennykh seroj-35 i fosforom-32. Sozdanie stojkikh k istiraniyu plenok na poverkhnosti zub'ev shesterenok izuchalos' kak funktsiya nagruzki, skorosti i vremeni raboty. Vopros, vstrechayushchijsya vo mnogikh iz vidov ehtogo primeneniya, sostoit v prevrashchenii izmeryaemoj aktivnosti v absolyutnye kolichestva materialov, prisutstvuyushchikh na poverkhnosti plenok ili v produktakh iznosa. Dlya ehtoj zhe tseli ispol'zovalis' metody kalibrovaniya. (author)

Production of Strontium-90 Thermal Power Sources; Fabrication de sources d'energie thermique au strontium-90; Proizvodstvo istochnikov ''teplovoj ehnergii iz Sr''9''0; Preparacion de fuentes de energia termica con estroncio-90

Energy Technology Data Exchange (ETDEWEB)

Cochran, J. S.; Bloom, J. L.; Schneider, A. [Martin Company, Nuclear Division, Baltimore 3, MD (United States)

1963-11-15

rajonakh. V ehtom smysle Sr{sup 90} priobretaet bol'shoe znachenie iz-za ego shirokoj dostupnosti, aktivnosti i toj sravnitel'noj legkosti, s kotoroj ego mozhno prevrashchat' v kompaktnye istochniki tepla. Generatory, rabotayushchie na Sr{sup 90} sluzhat v kachestve istochnikov pitaniya avtomaticheskikh meteorologicheskikh i navigatsionnykh stantsij; rassmatrivaetsya vozmozhnost' primeneniya Sr{sup 90} v kachestve istochnika ehnergii dlya dvigatelej kosmicheskikh korablej. Pri sravnitel'noj otsenke ryada strontsievykh soedinenij okazalos', chto naibolee tselesoobrazno ispol'zovat' titanat, tak kak on obladaet naibolee tsennymi svojstvami. Sr{sup 90}, otdelennyj ot drugikh produktov deleniya, ochishchaetsya do trebuemoj stepeni chistoty na predpriyatii Komissii po atomnoj ehnergii SSHA v Khehnforde i trasportiruetsya v vide karbonata v ''gorya- chuyu'' kameru(firmy ''Martin''), gde prevrashchaetsya v granulirovannyj titanat. V ehtom protsesse ispol'zuetsya distantsionnoe upravlenie, analogichnoe primenyaemomu v obychnom khimicheskom i keramicheskom proizvodstve. Granuly, zaklyuchennye v kapsuly, pomeshchayutsya v kontejnery tipa ''Khastellou C'' dlya primeneniya v ehnergeticheskikh ustanovkakh s termoehlektricheskim preobrazovaniem ehnergii. Zdes' prikhoditsya stalkivat'sya s neobychnymi ehkspluatatsionnymi problemami, tak kak bol'shie kolichestva obrabatyvaemogo Sr{sup 90} (milliony kyuri v god) obladayut strashnoj radioaktivnost'yu i sozdayut opasnost' zarazheniya. Opisano ustrojstvo prisposoblenij, oborudovaniya, kharakterizuyutsya tekhnologiya i tekhnika bezopasnosti. Opisyvayutsya dannye opyta, priobretennogo vo vremya nedavnej pererabotki pervykh 250 000 kyuri Sr{sup 90} v toplivo dlya generatora SNAP-7 (yadernaya batareya). Privodyatsya takzhe dannye po germetizatsii granul v kontejnerakh, po kalorimetrii, dezaktivatsii i metodike udaleniya otkhodov. (author)

Reactions of Hot Tritium Atoms with Amino Acids; Reactions entre Atomes Chauds de Tritium et Acides Amines; Reaktsii goryachikh atomov tritiya s aminokislotami; Reacciones de Atomos de Tritio Calientes con Aminoacidos

Energy Technology Data Exchange (ETDEWEB)

Simonov, E. F.; Nesmejanov, An. N. [Moskovskij Gosudarstvennyj Universitet, Moskva, SSSR (Russian Federation)

1965-04-15

investigaron los rendimientos de las reacciones de los atomos calientes de tritio: a) con aminoacidos, de longitud de cadena creciente; b) con aminoacidos de longitud de cadena constante, pero que contenian distintos grupos funcionales. Con esta finalidad irradiaron durante 15 min, con un flujo de 0,87 * 10{sup 13} neutrones lentos/cm{sup 2} * s, mezclas de carbonato de litio con los aminoacidos que se querian estudiar. Efectuaron los analisis cromato- graficos en fase gaseosa con ayuda de columnas intercambiables (tamices moleculares, parafina liquida en diatomeas) asi como por cromatografia sobre papel. Los datos obtenidos acerca de la resistencia a la radiolisis de los aminoacidos en funcion de la longitud de la cadena carbonada, aunque esten en contradiccion con una de las reglas fundamentales de la radioquimica, a saber, que la resistencia de las moleculas aumenta con el aumento de la longitud de su cadena, pueden explicarse por la transferencia intramolecular de energia a lo largo de la cadena carbonada, desde el lugar de impacto del atomo caliente al grupo oxidrilo y su subsiguiente ''desexcitacion''. En cambio, si bien la energia de los atomos de retroceso del tritio es mayor que la energia de enlace quimico, esta ultima influye en la resistencia a la radiolisis de las moleculas cuya longitud de cadena es la misma, pero que contienen distintos grupos funcionales. (author) [Russian] V literature v nastojashhee vremja otsutstvujut sistematicheskie dannye o vzaimodejstvii atomov otdachi tritija s aminokislotami. V to zhe vremja, takie dannye v sochetanii s imejushhimisja rezul'tatami dlja organicheskih kislot i aminov mogli by pomoch' ustanovit' mehanizm gorjachih reakcij, v zavisimosti ot struktury soedinenij (dlina cepi, funkcional'nye zamestiteli). Byli issledovany vyhody reakcii gorjachih atomov tritija: 1) s aminokislotami pri uvelichenii dliny cepi poslednih, 2) s aminokislotami odnoj dliny uglerodnoj cepi, no raznymi funkcional'nymi zamestiteljami. Dlja jetoj celi

Liquid Scintillation Detection of Tritium and other Radioisotopes in Insoluble or Quenching Organic Samples; Detection par compteur a scintillations a liquides du tritium et des autres radioelements contenus dans des echantillons organiques insolubles ou coupeurs; Obnaruzhenie tritiya metodom zhidkostnoj stsintillyatsii v nerastvorimykh ili sposo'nykh gasit' izluchenie organicheskikh o'raztsakh; Deteccion del tritio u otros radioisotopos por centelleo liquido en muestras organicas insolubles o que provocan extincion

Energy Technology Data Exchange (ETDEWEB)

Eastham, J F; Westbrook, H L; Gonzales, D [University of Tennessee, Knoxville, TN (United States)

1962-01-15

las sustancias organicas, a saber, el recuento por centelleos de liquidos. Estos inconvenientes, que son la extincion del centelleo producida por. muchas muestras organicas y la escasa solubilidad de otras, son particularmente frecuentes en las sustancias de importancia biologica. El procedimiento ideado por los autores consiste en lo siguiente: combustion de la muestra, envuelta en papel de filtro, en un matraz lleno de oxigeno; disolucion de los productos de combustion en un disolvente adecuado que se introduce en el matraz antes de la combustion, y recuento por centelleo de la actividad de la solucion. Ademas de superar los inconvenientes mencionados, este procedimiento posee otras ventajas: eficacia con muestras de actividades muy diversas (algunas, tan baja como 1{mu}c/M), precision (tan elevada como la de cualquier otro metodo general de radioanalisis del {sup 3}H) y posibilidad de aplicarlo a otros emisores beta blandos ({sup 14}C y {sup 35}S). Con un espectrometro de centelleo y merced al procedimiento ideado, es posible efectuar un radioanalisis diferencial de muestras marcadas con tres indicadores ({sup 3}H, {sup 14}C y {sup 35}S). Los autores describen con detalle las tecnicas y los sistemas de disolventes utilizados. Asimismo, exponen los resultados obtenidos en el analisis de sustancias que provocan extincion, como 2,4- dinitrofenilhidrazona s y colorantes de tiazol, y de sustancias insolubles, como proteinas e hidratos de carbono. Estudian la aplicacion de estas tecnicas al analisis de los efectos isotopicos {sup 1}H/{sup 3}H en ciertas reacciones de reduccion. (author) [Russian] CHtoby oblegchit' izuchenie vliyaniya izotopa H{sup 1}/H{sup 3} na vosstanovlenie organicheskikh soedinenij neobkhodimo bylo razrabotat' protsedury dlya preodoleniya dvukh osnovnykh ogranichenij v naibolee udobnom obshchem metode izmereniya radioaktivnosti organicheskikh veshchestv posredstvom zhidkostnogo stsintillyatora . EHti ogranicheniya, kotorymi yavlyayutsya

Compounds Labelled with Low-Energy Gamma-Ray Emitters for Medical Isotope Scanning; Gammagraphie au Moyen de Composes Marques avec des Emetteurs Gamma de Faible Energie; Soedineniya, ispol'zuemye pri meditsinskom izotopnom skennirovanii, mechennye s pomoshch'yu gamma-izluchatelej nizkoj ehnergii; Compuestos Marcados con Emisores Gamma de Baja Energia para la Exploracion Medica Mediante Isotopos

Energy Technology Data Exchange (ETDEWEB)

Scheer, K. E.; Zum Winkel, K.; Georgi, M. [Czerny-Krankenhaus der Universitat Heidelberg, Federal Republic of Germany (Germany)

1964-10-15

izluchenija v tkanjah organizma ogranichivaet glubinu obnaruzhenija povrezhdeg nij. V krupnyh organah, naprimer v pecheni, ustranjaetsja nalozhenie izluchenija ot zadnego otdela organa. Jeto pozvoljaet luchshe obnaruzhivat' bolee poverhnostnye porazhenija. Naibolee vazhnym gamma-izluchajushhim radioizotopom nizkoj jenergii javljaetsja jod-125, pri skennirovanii shhitovidnoj zhelezy on ispol'zuetsja v forme iodida. Sootvetstvujushhim soedineniem dlja skennirovanija pecheni javljaetsja mechennaja jodom-125 bengal'skaja roza. Drugim soedineniem javljaetsja jod-125 -CAI (denaturirovannyj pri vysokoj temperature al'bumin). Ustanovleno, chto pri skennirovanii pochek naibolee podhodjashhim soedineniem dlja vnutrimyshechnogo vvedenija vmeste s gialuronidazoj s cel'ju obespechenija ravnomernogo urovnja radioaktivnosti v pochkah javljaetsja jod-125-gippuran. Drugim poleznym gamma-izluchajushhim radioizotopom nizkoj jenergii, kotoryj primenjaetsja pri medicinskom skennirovanii, javljaetsja rtut'-197, kotoryj mozhno ispol'zovat' v vide hlorida pri skennirovanii pochek i selezenki. Neobhodimo predprinimat' osobye mery predostorozhnosti, chtoby izbezhat' perekryvanija pochek i selezenki. Pri ispol'zovanii neogidrina, mechennogo rtut'ju-197, poluchajut bolee vysokokachestvennye skennogrammy. Jeto soedinenie primenjaetsja takzhe dlja ustanovlenija lokalizacii mozgovyh opuholej. Obsuzhdajutsja tipichnye skennogrammy shhitovidnoj zhelezy, pecheni, selezenki, pochek i mozgovyh opuholej, poluchennye s pomoshh'ju gamma-izluchatelej nizkoj jenergii, i obychnyh radioizotopov i soedinenij, a takzhe dostoinstva pervyh. (author)

Some solvent extraction studies of trivalent metal halides; Quelques etudes sur l'extraction par solvant d'halogenures de metaux trivalents; Izuchenie ehkstraktsii nekotorykh rastvoritelej iz trekhvalentnykh metallicheskikh galoidov; Algunos estudios de la extraccion mediante disolventes de haluros de metales trivalentes

Energy Technology Data Exchange (ETDEWEB)

Dietz, Jr, R J; Mendez, J; Irvine, Jr, J W [Department of Chemistry and Laboratory for Nuclear Science, Massachusetts Institute of Technology, Cambridge, MA (United States)

1962-03-15

'no vysokimi diehlektricheskimi svojstvami. Po kolebaniyam koehffitsienta ehkstraktsii pri razlichnoj kontsentratsii metalla byla poluchena konstanta ionizatsii vspomogatel'nogo ehlektrolita, HCl ili HBr, v nevodnoj faze s ispol'zovaniem metoda, razrabotannogo Poskantserom. Variatsii koehffitsienta ehkstraktsii s kontsentratsiej HX ispol'zovalis' dlya rascheta konstant stabil'nosti dlya slozhnykh obraztsov MX{sub 3} i MX{sub 4}{sup -}. Tak kak oni yavlyayutsya reaktsiyami vodnoj fazy, to ne zavisyat ot ispol'zovannogo organicheskogo rastvoritelya, i poluchena polnaya soglasovannost' dlya In (III)-HCl pri ispol'zovanii dvojnogo ehfira (2-khloroehtil) i nitrobenzola. Popytki provedeniya otsenki obrazovaniya konstant dlya gallievogo khlorida i soedinenij broma okonchilis' neudachej, tak kak slozhnoe obrazovanie proiskhodit v ochen' uzkom diapazone kontsentratsii kisloty. Raschety na osnove rezul'tatov ehkstraktsii fraktsii (GaCl{sub 4}{sup -})/{Sigma} Ga (III) v kachestve funktsii ot kontsentratsii NS1 nakhodyatsya v kolichestvennom sootvetstvii s rezul'tatami, poluchennymi Krausom i Nel'sonom pri izmerenii ionnogo obmena. (author)

Radioisotope Scanning of the Pancreas with Selenomethionine-Se{sup 75}; Gammagraphie du Pancreas a l'Aide de la Selenomethionine-{sup 75}Se; Diagnosticheskoe fotoskennirovanie podzheludochnoj zhelezy; Gammagrafia del Pancreas Mediante Radioisotopos

Energy Technology Data Exchange (ETDEWEB)

Sodee, D. B. [Doctors Hospital and Renner Clinic Foundation, Cleveland Heights, OH (United States)

1964-10-15

voznikajushhee v rezul'tate koncentraciiselenometionina - {sup 75}Se v pecheni izluchenie, kotoroe v proshlom meshalo tochnomu opredeleniju kontura podzheludochnoj zhelezy. Nedavno avtory ispol'zovali kristall razmerom 12,5 h 7,5 sm i 121-kanal'nyj svincovyj kollimator s fokusnym rasstojaniem 12,5 sm. Jeto uluchshilo kachestvo izobrazhenija, i po mere usovershenstvovanija metodiki mozhno budet, verojatno, videt' men'shie povrezhdenija na bol'shej glubine. Okazalos',chto karcinoma podzheludochnoj zhelezy koncentriruet selenometionina -Se75 . huzhe, chem normal'naja tkan'. S pomoshh'ju jetoj metodiki udalos' pravil'no istolkovat' zabolevanie u 5 iz 6 bol'nyh, stradajushhih karcinomoj podzheludochnoj zhelezy. Nepoddajushhiesja obnaruzheniju Mel'chajshie karcinomatoznye uzly byli zatemneny uvelichennoj pechen'ju. Diagnoz ostrogo i hronicheskogo pankreatita takzhe podtverzhdaetsja skennirovaniem podzheludochnoj zhelezy, poskol'ku povrezhdennye kletki podzheluzhochnoj zhelezy ne koncentrirujut selenometionin -{sup 75}Se. Avtor takzhe opisyvaet izbiratel'noe pogloshhenie selenometionina -{sup 75}Se tkan'ju para- shhitovidnoj zhelezy . S pomoshh'ju jetogo zhe metoda skennirovanija byli obnaruzheny adenomy parashhitovidnoj zhelezy u nebol'shoj gruppy bol'nyh s povyshennoj funkciej parashhitovid- noj zhelezy. Fotoskennirovanie podzheludochnoj zhelezy uzhe javljaetsja prakticheskim metodom, i v nastojashhee vremja vedetsja izuchenie fotoskennirovanija parashhitovidnoj zhelezy. Narjadu s vnov' probudivshimsja interesom k organam, kotorye byli nevidimy pri obychnyh radiograficheskih metodah, selektivnoe skennirovanie organov s pomoshh'ju soedinenij,soderzhashhih mechenye atomy i podobrannyh po ih biohemicheskim svojstvam, stanovitsja vazhnym metodom budushhego. (author)

Sample Preparations Used in Biomedical Research and Training at the Special Training Division of the Oak Ridge Institute of Nuclear Studies; Methodes de Preparation d'Echantillons Employees dans la Recherche et la Formation Biologiques et Medicales a la Division de Formation Speciale de l'Institut d'Etudes Nucleaires d'Oak Ridge; Prigotovlenie obraztsov dlya biomeditsinskikh issledovanij i dlya uchebnykh tselej v otdele spetsial'noj podgotovki okridzhskogo instituta yadernykh issledovanii; Metodos de Preparacion de Muestras Aplicados en las Investigaciones Biomedicas y en la Capacitacion Profesional de la Division de Formacion Especial del Instituto de Estudios Nucleares de Oak Ridge

Energy Technology Data Exchange (ETDEWEB)

Akers, L. K. [Oak Ridge Institute of Nuclear Studies, Oak Ridge, TN (United States)

1965-10-15

ambientales lleva a cabo una labor considerable de preparacion de muestras muy delgadas que permiten alcanzar una resolucion mas elevada de los espectros alfa. Para ello se utilizan procedimientos de deposito electrolitico a partir de mezclas disolventes. Se efectuan mediciones con una bateria especial de contadores Fairstein-Frisch de rejilla conectados a un analizador de 512 canales para el registro simultaneo de mas de un espectro. Tambien se utilizan detectores de estado solido y se comparan los resultados obtenidos con detectores de rejilla y de semiconductores. (author) [Russian] Pri osushhestvlenii issledovatel'skih i uchebnyh programm Otdela special'noj podgotovki ispol'zujut samye raznoobraznye metody prigotovlenija obrazcov. Oni vkljuchajut kak prostye derzhateli istochnikov, naprimer metallicheskie, kartonnye i plastmassovye, tak i ustrojstva dlja osazhdenija, v kotoryh ispol'zujutsja derzhateli iz nerzhavejushhej stali i steklovolokna, a takzhe special'nye derzhateli istochnikov dlja izmerenija obrazcov v zhidkostnyh schetchikah. Krome jetih metodov, razrabotan rjad metodov, predstavljajushhih osobyj interes pri izuchenii biomedicinskih problem. Odnim iz naibolee vazhnyh iz jetih metodov javljaetsja ispol'zovanie kataliticheskogo sinteza benzola, kotoryj razrabotan do takoj stepeni, chto obshhij vyhod sostavljaet bolee 90% . Jetot sintez mozhno ispol'zovat' dlja uglerodnyh soedinenij, predstavljajushhih interes pri provedenii jeksperimentov s indikatornymi kolichestvami i izuchenii problem opredelenija vozrasta. Poskol'ku sintez svjazan s polucheniem dvuokisi ugleroda na odnoj stadii i s gidrataciej metallicheskogo karbida na drugoj stadii, ego mozhno ispol'zovat' libo dlja izmerenija ugleroda-14 ili tritija, libo ih odnovremennogo izmerenija vo vremja jeksperimentov s dvojnym mecheniem. Znachitel'naja rabota prodelana v oblasti aktivacionnogo analiza biologicheskih materialov, v chastnosti, po osushhestvleniju radiojekologicheskih programm Otdela. Opisyvajutsja

Recoil Processes of Cr{sup 51} in Mixed Inorganic Systems; Processus de Recul de {sup 51}Cr dans des Melanges Inorganique; 041f 0420 041e 0426 0415 0421 0421 042b 0421 042f 0414 0420 0410 041c 0418 041e 0422 0414 0410 0427 0418 0425 0420 041e 041c 0410 -51 0412 0421 041c 0415 III 0410 041d 041d 042b 0425 041d 0415 041e 0420 0413 0410 041d 0418 0427 0415 0421 041a 0418 0425 0421 0418 0421 0422 0415 041c 0410 0425 ; Procesos de Retroceso del {sup 51}Cr en Sistemas Inorganicos Mixtos

Energy Technology Data Exchange (ETDEWEB)

Veljkovic, S. R.; Milenkovic, S. M.; Ratkovic, M. R. [Boris Kidric Institute of Nuclear Sciences, Vinca, Yugoslavia (Serbia); Faculty Of Natural Sciences, Belgrade University, Belgrade, Yugoslavia (Serbia)

1965-04-15

smesjah hromatov ili solej hroma s neorganicheskimi okislami. V kachestve okislov ispol'zovalis' AI{sub 2}O{sub 3}, SiO{sub 2} i MgO. Termicheskie jeffekty kontrolirovalis' parallel'no dlja ocenki chisto teplovyh vozdejstvij v reaktore i dlja ocenki vozmozhnogo vnutrennego nagreva v mishenjah. V sisteme, gde hromaty byli osazhdeny na MgO, nabljudalos' sil'noe vosstanovlenie do hrom-iona. Pri temperature obluchenija nejtronnye jeffekty prevalirovali nad termicheskimi processami i tol'ko nagrevanie do temperatury vyshe 600 Degree-Sign S davalo podobnyj rezul'tat. Ion hroma vo vremja obluchenija ne izmenilsja. Uvelichenie koncentracii hromatov privodilo k horosho izvestnomu uderzhaniju Cr{sup 51}O{sub 4}{sup =}. Hromaty, adsorbirovannye na glinozeme, sohranjali formu okisi tak zhe, kak i v sisteme s SiO{sub 2}. Teplovye jeffekty imeli to zhe samoe napravlenie. Ion hroma, absorbirovannyj na jetih okisjah, vedet sebja razlichno. V sisteme s glinozemom otmechalos' sil'noe okislenie, kotoroe znachitel'no prevyshalo vklad teplovyh processov. Pri sravnenii jeffekta obluchenija i nagreva v sisteme s SiO{sub 2} obnaruzhena nebol'shaja raznica, hotja bylo otmecheno bol'shoe diffuzionnoe obednenie poverhnosti ionami hroma. Obshhaja osobennost' vseh sistem sostoit v ochen' nebol'shoj koncentracii soedinenij hroma. Himija tonkogo sloja, po-vidimomu, otlichaetsja ot obychnogo povedenija bol'shih mass hromatov v bol'shinstve sluchaev, kak v teplovyh processah, tak i v processe otdachi. Jeto mozhet oznachat', chto processy v ''gorjachih tochkah'', nahodjas' v zavisimosti ot vseh komponentov, mogut davat' himicheskie produkty, chuvstvitel'nye k harakteru misheni. Obobshhennaja kartina processov s jadrami otdachi v tverdyh soedinenijah, po-vidimomu, nuzhdaetsja v dopolnitel'nom rassmotrenii voprosa o materiale matric. (author)

Production, soil erosion and economic failure in new citrus plantations in Eastern Spain

Science.gov (United States)

Giménez Morera, Antonio; Carles membrado, Joan; Cerdà, Artemi; Ángel González Peñaloza, Félix

2013-04-01

investment to develop the new plantations, an income lower than the expenses, the removal of terraces, drainage and irrigation ditches and the high erosion rates show a Desertification process triggered by the commercial agriculture of citrus. Acknowledgements The research projects GL2008-02879/BTE and LEDDRA 243857 supported this research. References Bono, E. 2010. Naranja y desarrollo. La base agrícola exportadora de la economía del País Valenciano y el modelo de crecimiento hacea afuera. PUV, Valencia, 203 pp. Cerdà, A. 2001. Erosión hídrica del suelo en el Territorio Valenciano. El estado de la cuestión a través de la revisión bibliográfica. Geoforma Ediciones, Logroño, 79 pp. Cerdá, A. 2007. Soil water erosion on road embankments in Eastern Spain. Science of the Total Environments 378, 151-155. Cerdà, A., Morera, A.G., Bodí, M.B. 2009. Soil and water losses from new citrus orchards growing on sloped soils in the western Mediterranean basin. Earth Surface Processes and Landforms, 34 (13), 1822-1830. García-Orenes, F., Cerdà, A., Mataix-Solera, J., Guerrero, C., Bodí, M.B., Arcenegui, V., Zornoza, R. & Sempere, J.G. 2009. Effects of agricultural management on surface soil properties and soil-water losses in eastern Spain. Soil and Tillage Research, doi:10.1016/j.still.2009.06.002 González-Peñaloza, F.A., Cerdà, Zavala, L.M., Jordán, A. 2012. Do conservative agriculture practices increase soil water repellency? A case study in citrus-cropped soils. Soil & Tillage Research 124, 233 - 239. Liu, Y., Tao, Y., Wan, K.Y., Zhang, G.S., Liu, D.B., Xiong, G.Y., Chen, F. 2012. Runoff and nutrient losses in citrus orchards on sloping land subjected to different surface mulching practices in the Danjiangkou Reservoir area of China. Agricultural Water Management, 110, 34-40. Piqueras, J. 1999. El espacio Geográfico valenciano. Una síntesis geográfica. Valencia, 356 pp. Piqueras, J. 2012. Geografía del Territorio Valenciano. Departament de Geografia, Universitat

Nucleic Acids and Protein Metabolism of Bone Marrow Cells Studied by Means of Tritiumlabelled Precursors; Etude du Metabolisme des Acides Nucleiques et des Proteines dans les Cellules de la Moelle Osseuse, a l'Aide de Precurseurs Trities; 0418 0437 0443 0414 ; Estudio con Ayuda de Precursores Tritiados del Metabolismo de los acidos Nucleicos y de las Proteinas en las Celulas de la Medula Osea;

Energy Technology Data Exchange (ETDEWEB)

Gavosto, F. [Istituto di Clinica Medica Generale e Centro di Studi Fisico-Biologici, Universita de Turin, Turin (Italy)

1962-02-15

demostrado que en las celulas normales de la medula osea la razon entre la incorporacion de uridina y la de aminoacidos permanece constante. En los casos de leucemia aguda, la incorporacion de acido ribonucleico y de precursores proteinicos en las celulas leucemicas es siempre sensiblemente mas reducida, aunque varia de un caso a otro. Asimismo, la razon entre la incorporacion de uridina y la de aminoacidos se altera constantemente en estas celulas. El autor estudia la disminucion y disociacion del metabolismo del acido ribonucleico y de las proteinas en las celulas leucemicas (leucemia aguda), relacionando estos fenomenos con la maduracion defectuosa, tipica de estas celulas. (author) [Russian] Obsuzhdajutsja prei- mushhestva ispol'zovanija mechennyh tritiem slozhnyh soedinenij v metodah avto- radiograficheskogo analiza. Dejstvitel'no, jelektrony tritija obladajut maksi- mal'noj jenergiej 0,018 Mjev, chto sootvetstvuet priblizitel'no rasstojaniju 1 mikrona na fotograficheskoj plenke, dostigaja tem samym nailuchshej vozmozh- noj razreshajushhej sposobnosti v masshtabe kletok i ih komponentov. Jeto osobenno polezno pri izuchenii javlenij metabolizma v tkanjah, sostojashhih; kak jeto imeet mestno v kostnom mozge, iz raznovidnostej kletok, nahodjashhihsja na razlichnoj stadii differenciacii. Jetot metod byl ispol'zovan dlja issledovanija metabolizma nukleinovyh kislot i proteina v zdorovyh i porazhennyh lejkemiej kletkah kostnogo mozga. Izuchenie metabolizma dioksiribonukleinovoj kisloty proizvodilos' pri pomoshhi specificheskogo predshestvennika, a imenno timidina tritija. Putem sopostavlenija nahodjashhihsja na odnoj i toj zhe stadii sozrevanija chastic zdoro- vyh i porazhennyh lejkemiej tkanej byli obnaruzheny znachitel'nye rashozhde- nija v procentnyh doljah mechenyh kletok. V chastnosti, v jachejkah, porazhennyh ostroj lejkemiej, nabnjudalos' gorazdo bolee slaboe pogloshhenie timidina, chto prinimalos' za dokazatel'stvo men'shej sposobnosti razmnozhenija jetih kletochek po

On the Behaviour of Radioisotopes Incorporated in Glass Blocks; Le Comportement des Radioisotopes Vitrifies; O Povedenii Radioaktivnyh Izotopov, Lokalizovannyh v Steklovidnyh Blokah; Comportamiento de los Radioisotopos Vitrificados

Energy Technology Data Exchange (ETDEWEB)

Zimakov, P. V.; Kulichenko, V. V.; Duhovich, F. S.; Salamatmn, B. A.

1963-02-15

steklovidnyh blokov, kak pravilo, vozrastaet posle ih progreva svyshe 400 Degree-Sign C. Otsjuda nezhelatel'no dopuskat' obrazovanija slishkom vysokih temperatur v mogil'nikah. Vysokaja plotnost' radiacii vysokoradioaktivnyh blokov takzhe-sil'no vlijaet na izmenenie struktury blokov, a sledovatel'no i prochnosti lokalizacii v nih oskolochnyh izotopov. Izmenenija takzhe idut v pervuju ochered' s poverhnosti pri kontakte s vneshnej sredoj (vozduh, voda). Vyshela- chivaemost' izotopov iz obluchaemyh blokov, kak pravilo, uvelichivaetsja. Jeksperimental'no ustanovlen povyshennyj vyhod radioaktivnyh izotopov s poverhnosti v gazovuju fazu dlja radioaktivnyh blokov. - Uchityvaja sovokupnost faktorov, dejstvujushhih na steklovidnye bloki v techenie dlitel'nogo vremeni, nuzhno putem special'nogo podbora ih himicheskogo sostava (fljusa) i''uslovij prigotovlenija,' obespechit' nadezhnuju lokalizaciju radioaktivnyh izotopov v zahoronennyh blokah; Osobyj interes v jetom otnoshenii predstavljaet primenenie dlja fljusovanija soedinenij titana. (author)

Technique for the Measurement of Low-Level Radioactivity of Organic Iodine in Large-Volume Urine Samples; Technique de Mesure de la Faible Radioactivite de l'Iode Organique Contenu dans des Echantillons d'Urine de Grand Volume; Metod izmereniya nizkikh aktivnostej organicheskogo joda v krupnykh obraztsakh mochi; Tecnicas de Medicion de Bajas Actividades de Yodo Organico Contenido en Muestras de Orina de Gran Volumen

Energy Technology Data Exchange (ETDEWEB)

Nicolesco-Zinca, D.; Matei, I. [Institut d' Endocrinologie de l' Academie Roumaine, Bucarest (Romania)

1965-10-15

que presentan una desyodacion normal y en 10 cretinos con bocio, en cinco de los cuales la desyodacion era deficiente. Se administro 1 {mu}Ci de diyodotirosina-{sup 131}I. El metodo se puede emplear administrando una dosis radiactiva por lo menos 50 veces menor y permite separar la diyodotirosina y recuperarla en una muestra de 40 a 50 mi de orina con un error tipo de 0,42% en un plazo de algunas horas; requiere un aparato de centelleo con cristal de Nal hueco que se encuentra corrientemente en los laboratorios de medicina nuclear. (author) [Russian] V jadernoj jendokrinologii voznikajut dve bol'shie problemy v otnoshenii opredelenija pochechnogo vydelenija joda kak organicheskih soedinenij,' mechennyh in vitro: - ih kolichestvennoe razdelenie ot iodistogo soedinenija, prisutstvujushhego v moche, dazhe esli koncentracija joda v dvadcat' raz bol'she; - opredelenie ih nizkoj aktivnosti v krupnyh obrazcah mochi, prichem koncentracija na 1 ml mochi sostavljaet priblizitel'no 10{sup -5} ot vvedennoj aktivnosti, kotoraja dolzhna, v svoju ochered', byt' po vozmozhnosti nizkoj. Obychno razdelenie proizvoditsja metodom bumazhnoj hromatografii, kotoryj ispol'zuet lish' nebol'shie obrazcy mochi. Jetot metod trudoemok, trebuet mnogo vremeni i priborov dlja hromatografii. Pri opredelenii aktivnosti na bumage zagrjaznenie obnaruzhivaetsja na vsej lente. Nesmotrja na popravki rekuperacija aktivnosti sostavljaet lish' 89,9%i eshhe men'she, esli primenjaetsja butanovyj jekstrakt. Po izlagaemomu metodu krupnyj obrazec mochi prohodit cherez mikrokolonku kationobmen- noj smoly N{sup +}. Organicheskie soedinenija radioaktivnogo ioda fiksirujutsja na kationobmennoj smole, i ih aktivnost' opredeljaetsja s pomoshh'ju scintilljacionnogo zonda, imejushhego kristall NaJ(Tl). Posle proverki dlja zadannyh uslovij rekuperacii diiodotirozina mochi my nashli molnuju rekuperaciju so standartnymi pogreshnostjami v srednem 0,42% dlja 10 jeksperimentov . Jetot metod primenjalsja dlja opredelenija

Personnel Dosimeters with Radiation Elements; Dosimetres Individuels Comportant des Elements Emetteurs; 0418 041d 0414 0418 0412 0418 0414 ; Dosimetros Individuales Provistos de Elementos Emisores

Energy Technology Data Exchange (ETDEWEB)

Hosemann, R.; Warrikhoff, H. F.H. [Fritz-Haber-Institut der Max-Planck-Gesellschaft, Berlin-Dahlem, Federal Republic of Germany (Germany)

1965-06-15

construccion en forma eliptica o esferica del elemento es preferible a cualquier otra. Las dimensiones externas del instrumento son las mismas que las de los dosimetros tipo estilografica corrientemente utilizados. Cada aparato esta provisto de un conmutador de descarga y de un dispositivo de mando. (author) [Russian] Jelementom izluchenija javljaetsja vakuumnyj diod, jelektrody kotorogo izluchajut jelektrony razlichnogo zarjada na edinicu izluchenija. Poskol'ku ispuskaemye jelektrony pokidajut odin jelektrod s vysokoj jenergiej, to drugoj jelektrod mozhet zarjazhat'sja do proporcional'no vysokogo naprjazhenija bez dopolnitel'noj jenergii. V sootvetstvii s jetim svojstvom, jeti sistemy neposredstvennogo otscheta nazyvajutsja jelementami izluchenija. Dlja togo chtoby izmerit' rentgenovskie i gamma-luchi, odin jelektrod delaetsja iz svinca, a drugoj iz ugleroda. Nezavisimost' ot dliny volny po otnosheniju k edinice rentgena poluchena s pomoshh'ju tak nazyvaemogo metoda fil'tracii jelektrona. Chuvstvitel'nost' sostavljaet priblizitel'no 0,5 vol't/rentgen {+-} 8% v diapazone ot 80 kjev do 1,25 Mjev (polnyj masshtab 200 - 2000 rentgen, libo linejnyj kvazi-logarifm). Dlja izmerenija medlennyh i bystryh nejtronov vyzvannaja beta-aktivnost' jelektrodov zarjazhaet vstroennyj jelektron. Predstavljaetsja vozmozhnym izmerit' gamma-luchi, a takzhe i nejtrony v edinicah bjer s pomoshh'ju odnogo instrumenta. Nejtronnaja chuvstvitel'nost' gamma-jelementa mozhet byt' fakticheski nulevoj, odnako gamma-chuvstvitel'nost' nejtronnogo jelementa vyzovet nekotorye trudnosti. Harakternymi preimushhestvami jetih instrumentov javljajutsja: 1. SamOzarjazhajushhiesja sistemy, vsegda gotovye k dejstviju, neogranichennoe vremja hranenija, otsutstvie batarej ili zarjazhajushhih komponentov. 2. Chrezvychajno nizkoe zatuhanie, poskol'ku dlja izoljacii ispol'zujutsja vakuum i kvarc. 3. Kachestvennost' izmerenij naibolee vysokoj dozy vsledstvie otsutstvija vozdejstvija novyh soedinenij (vakuum). 4. Libo

Chemical Behaviour of C{sup 11} in Liquid Hydrocarbons; Comportement Chimique de {sup 11}C dans les Hydrocarbures Liquides; Khimicheskaya kharakteristika ugleroda-11 v zhidkikh uglevodorodakh; Comportamiento Quimico del {sup 11}C en Hidrocarburos Liquidos

Energy Technology Data Exchange (ETDEWEB)

Voigt, A. F.; Clark, D. E.; Mesich, F. G. [Institute of Atomic Research and Department of Chemistry, Iowa State University, Ames, IA (United States)

1965-04-15

obshhim kolichestvom obrazovavshegosja C{sub 11}, izmerennym vo vsem obrazce pered razdeleniem. Protochnye schetchiki kalibrovalis' pri uslovii obrazovanija vsego Si v hode jeksperimentov, v processe kotoryh ves' obrazec szhigalsja, prevrashhajas' v CO{sub 2}, i prohodil cherez protochnyj schetchik. Nashi bolee rannie jeksperimenty byli svjazany tol'ko s ispol'zovaniem gazoobraznyh produktov, kotorye v nastojashhee vremja horosho zarekomendovali sebja v otnoshenii molekul razlichnyh veshhestv misheni pri raznyh znachenijah dozy. Tekushhie jeksperimenty s proizvodnymi molekulami, podobnymi po razmeru molekulam materiala misheni, okazalis' ochen' poleznymi pri izuchenii voprosa o mehanizmah rekombinacii atomov otdachi. Osobyj interes predstavljaet vyhod produkta s odnim atomom ugleroda bol'she po sravneniju s mishen'ju, chto javljaetsja rezul'tatom novoj reakcii. Raspolozhenie dopolnitel'nogo atoma v molekule veshhestva misheni, kotoroe harakterizuetsja nalichiem neskol'kih dopolnitel'nyh tochek, daet informaciju otnositel'no samogo processa. Pri zamedlenii atoma otdachi do velichiny jenergii, pri kotoroj vozmozhno ustanovlenie svjazi, po krajnej mere vremenno, izlishnjaja jenergija, kotoruju prinosit v sistemu atom C{sub 11}, mozhet privesti k razryvu svjazi gde-libo v drugom meste v predelah aktiviruemogo kompleksa, chto obychno privodit k obrazovaniju dvuhuglerodnogo produkta. Esli kompleks mozhet byt' sohranen bez razryva, to obrazuetsja dopolnitel'nyj produkt. Takim obrazom, sravnenie vyhodov dvuhuglerodnyh soedinenij, acetilena, jetilena i jetana i dopolnitel'nyh produktov predostavljaet cennuju informaciju otnositel'no jenergii, pri kotoroj vozmozhno obrazovanie ustojchivoj svjazi, i haraktera soderzhashhej C{sub 11} gruppy, vstupajushhej v reakciju. (author)

Indirect Determination of Half-Lives of Short-Lived Fission Gases Using a Gas Flow Method; Determination Indirecte des Courtes PeRiodes de Produits de Fission Gazeux, par une Methode a Courant Gazeux; 041a 041e 0421 0412 0415 041d 041d 041e 0415 041e 041f 0420 0415 0414 0415 041b 0415 041d 0418 0415 041f 0415 0420 0418 041e 0414 041e 0412 041f 041e 041b 0423 0420 0410 0421 041f 0410 0414 0410 041a 041e 0420 041e 0422 041a 041e 0416 0418 0412 0423 0429 0418 0425 0413 0410 0417 041e - 041e 0411 0420 0410 0417 041d 042b 0425 041f 0420 041e 0414 0423 041a 0422 041e 0412 0414 0415 041b 0415 041d 0418 042f 0421 0418 0421 041f 041e 041b 042c 0417 041e 0412 0410 041d 0418 0415 041c 041c 0415 0422 041e 0414 041e 0412 0413 0410 0417 041e 0412 041e 0413 041e 041f 041e 0422 041e 041a 0410 ; Determinacion Indirecta del T 1/2 de los Cases de Fision de Periodo Corto por un Metodo de Circulacion

Energy Technology Data Exchange (ETDEWEB)

Patzelt, P.; Herrmann, G. [Institut fuer Anorganische Chemie und Kernchemie der Universitaet Mainz, Mainz, Federal Republic of Germany (Germany)

1965-07-15

.87 {+-} 0.15 min; {sup 138}Xe, 14.5 {+-} 0.5 min; {sup 139}Xe, 40.4 {+-} 1.3 s: {sup 140}Xe, 13.33 {+-} 0.27s; {sup 141}Xe, 1.70 {+-} 0.05s; {sup 142}Xe, 1.15 {+-} 0.04s- y {sup 143}Xe, 0.96 {+-} 0.02s. Los periodos de semidesintegracion se determinaron extrapolando las curvas correspondientes de desintegracion beta o las curvas de atenuacion de los picos gamma. Los datos enumerados representan los promedios resultantes de una serie de mediciones' a los que se ha aplicado un coeficiente de ponderacion W{sub i} Tilde-Operator 1/o{sup 2}. Todos los computos se rtan realizado en el centro de calculo electronico de la Universidad de Maguncia. (author) [Russian] Poskol'ku issledovanie raspredelenija zarjadov pri jadernom delenii trebuet opredelenija pervichnyh vyhodov otdel'nyh produktov delenija, kotorye v bol'shinstve sluchaev javljajutsja libo korotkozhivushimi sami po sebe, libo proishodjat iz korotkozhivushhih predshestvennikov, to neobhodimo provesti ochen' bystroe i jeffektivnoe razdelenie sosednih chlenov cepochki produktov delenija. Ispol'zuja chrezvychajno vysokuju jemanacionnuju sposobnost' nekotoryh uranovyh soedinenij, naibolee legko razdelit' gazoobraznye produkty delenija v bolee chem 12 cepochkah produktov delenija. Raschety vyhodov, a takzhe jeffektivnaja jemanacionnaja sposobnost' tolstyh sloev misheni mogut, odnako, ispytyvat' sushhestvennoe vlijanie so storony dannyh o periode poluraspada gazov. Pojetomu periody poluraspada izotopov kriptona i ksenona (Kr{sup 89}-Kr{sup 93} i Xe{sup 137}- X{sup 143}) {sup y}li opredeleny s bol'shoj tochnost'ju pri ispol'zovanii metoda skorosti potoka sovmestno s uluchshennym metodom zarjazhennogo jelektroda. Izmerenija proizvodilis' posredstvom aktivnogo otlozhenija dolgozhivushhih produktov raspadah na jelektrodah. ' Skorost' potoka, vremja obluchenija, period ohlazhdenija i sistema scheta izbiralis' takim obrazom, chtoby izmerenija otdel'nyh dochernih produktov okazalis' naibolee blagoprijatnymi. V nekotoryh sluchajah v

Chemical State of Radiobromine Formed by the Rb{sup 85}(n, {alpha}) Br{sup 82} Reaction; Etat Chimique Du Ra Diobrome Forme Par La Reaction {sup 85}Rb (n, {alpha}) {sup 82}Br; 0425 0418 041c 0418 0427 0415 0421 041a 041e 0415 0421 041e 0421 0422 041e 042f 041d 0418 0415 0420 0410 0414 0418 041e 0410 041a 0422 0418 0412 041d 041e 0413 041e 0411 0420 041e 041c 0410 , 041e 0411 0420 0410 0417 041e 0412 0410 041d 041d 041e 0413 041e 041f 0420 0418 0420 0415 0410 041a 0426 0418 0418 Rb{sup 85}(n, {alpha}) Br{sup 82}; Estado Quimico Del Radiobromo Formado Por La Reaccion {sup 85}Rb (n, {alpha}) {sup 82}Br

Energy Technology Data Exchange (ETDEWEB)

Vlatkovic, M.; Kauiic, S. [' ' Ruder Boskovic' ' Institute, Zagreb, Yugoslavia (Croatia)

1965-04-15

los atomos de {sup 82}Br de energia muy elevada y a su incapacidad de regenerarse en los compuestos de rubidio investigados. (author) [Russian] Jetot doklad kasaetsja himicheskogo raspredelenija radioaktivnogo broma mezhdu ego naivysshim (BrO{sub 3}{sup -}) i bolee nizkimi (Br{sup -}, Br{sub 2}, BrO{sup -}) sostojanijami okislenija, poluchaemymi v rezul'tate jadernyh reakcij Rb{sup 85}(n, {alpha}) Br{sup 82} v rjade neorganicheskih tverdyh soedinenij rubidija. Obrazcy vysushennogo Rb{sub 2}SO{sub 4}, Rb{sub 2}S{sub 2}O{sub 8}, RbMnO{sub 4}, RbNO{sub 3}, Rb{sub 2}CO{sub 3} i RblO{sub 3} byli oblucheny nejtronami s jenergiej 14 Mjev na nejtronnom generatore (tipa T+d). Okazalos', chto v sluchae Rb{sub 2}SO{sub 4}, obluchennogo pri komnatnoj temperature ili pri -195 Degree-Sign C, priblizitel'no 8% ot obshhej aktivnosti broma-82 bylo obnaruzheno v bromatnoj frakcii, ostal'naja chast' soputstvovala bromidnoj frakcii. Obluchenie RbMnO{sub 4} and RbNO{sub 3} pri komnatnoj temperature davalo primerno 1% aktivnosti, sootvetstvujushhej bolee vysokomu sostojaniju okislenija broma, hotja v sluchajah Rb{sub 2}S{sub 2}O{sub 8} , Rb{sub 2}CO{sub 3} i RblO{sub 3} aktivnost' mozhno bylo obnaruzhit' tol'ko v bromidnoj frakcii. Nebol'shoe uvelichenie aktivnosti bromata nabljudalos' takzhe, kogda obluchennyj nejtronami Rb{sub 2}SO{sub 4} nagrevalsja do 250 Degree-Sign C. Pri bolee vysokih temperaturah (do 500 Degree-Sign C) aktivnost' perehodila vo frakciju, sootvetstvujushhuju bolee nizkomu sostojaniju okislenija. Nagrevanie obluchennyh RbMnO{sub 4} i RbNO{sub 3} ne vyzyvalo nikakogo okislenija broma. Hotja v sluchae s RbNO{sub 3} predvaritel'noe gamma-obluchenie dozoj v 22 Mrad ne imelo nikakogo vlijanija na raspredelenie jader otdachi broma, analiz Rb{sub 2}SO{sub 4} predvaritel'no obluchennogo gamma-luchami (55 Mrad), daval bolee vysokuju aktivnost' bromata po sravneniju s obrazcami, kotorye do nejtronnogo obluchenija byli tol'ko vysusheny pri 150 Degree-Sign C. 5 zakljuchenie

Multidimensional Gamma-Ray Spectrometry and its Use in Biology; La Spectrometry Gamma Multidimensionnelle et son Application en Biologie; Mnogomernaya spektrometriya gamma-luchej i ee ispol'zovanie v biologii; La Espectrometria Gamma Multidimensional y su Empleo en Biologia

Energy Technology Data Exchange (ETDEWEB)

Nielsen, J. M.; Kornberg, H. A. [Battelle Memorial Institute, Pacific Northwest Laboratory, Richland, WA (United States)

1965-10-15

v prirode i obrazuemyj kosmicheskimi luchami), cezij-134 i cezij-137 (radioizotopy, obrazujushhiesja v rezul'tate vzryva bomb) mozhno legko izmerit' v fakticheski sushhestvujushhih kolichestvah (v nekotoryh sluchajah menee odnogo raspada v minutu na 1 kg) v mjase, rybe i drugih pishhevyh produktah, a takzhe v moche, chto pozvoljaet izuchat' processy pogloshhenija i vydelenija. Jetot metod pri- menim k issledovanijam, gde pribegajut k dobavleniju indikatorov, i mozhet byt' osobenno poleznym dlja odnovremennogo izmerenija pogloshhenija, otlozhenija i oborota rjada dolzhnym obrazom mechenyh soedinenij v organizme zhivotnogo. V sluchae ispol'zovanija sovmestno s nejtronnym aktivacionnym analizom jetot metod daet vozmozhnost' izmerjat' bol'shuju grup- pu jelementov v tkanjah i krovi dazhe na urovne neskol'kih chastej na milliard. (author)

Radiotracer Approaches to Carbamate Insecticide Toxicology; Emploi des radio indicateurs pour l'etude de la toxicologie des insecticides a base de carbamates; Primenenie radioaktivnykh indikatorov dlya izucheniya toksikologii karbamatnykh insektitsidov; Estudio con radioindicadores de la toxico logia de los insecticidas a base de carbamatos

Energy Technology Data Exchange (ETDEWEB)

Casida, J. E. [University of Wisconsin, Madison, WI (United States)

1963-09-15

5-[3-metil-2-dimetilcarbamil]- pirazolina) y un compuesto comparable indican tambien que el ataque oxidante forma derivados N-metilo y N-metilol. Faltan todavia muchos datos sobre la relacion entre esas reacciones de desintaxicacion y el mecanismo de resistencia, la accion de las sustancias sinergicas, la toxicidad selectiva de este grupo de insecticidas, y la naturaleza y el significado de los residuos. Es probable tambien que el metabolismo del Sevin inyectado en las plantas sea oxidativo mas que hidrolitico, pero no se ha establecido todavia la naturaleza de los productos y el mecanismo enzimatico. (author) [Russian] Metilkarbamaty yavlyayutsya odnoj iz glavnykh grupp insektitsidov. Mnogie nerazreshennye problemy toksikologii ehtikh veshchestv mogut byt' legko izucheny pri pomoshchi radioaktivnykh indikatorov. Byli izgotovleny N, N-dimetidkarbamaty, karbonilovaya gruppa kotorykh metilas' C{sup 14}, a takzhe N-metilkar- bamaty, metilovaya, karbonilovaya gruppa i kbl'tsa kotorykh byli mecheny C{sup 14}. Farmakologicheskoe dejstvie ehtikh slozhnykh soedinenij, veroyatno, svyazano s tormozheniem atsetilkholinesteraehy i mozhet vklyuchat' karbamilatsiyu. Mechenie karbonilovoj ili metilovoj gruppy karbamatov daet vozmozhnost' v ikh reaktsiyakh s ochishchennoj kholinesterazoj ili s drugimi ehsterazami kriticheski izuchit' reaktsiyu karbamida tsii, a takzhe legkost' samoproizvol'noj ili vyzvannoj reaktivatsii ili dekarbamilatsii. Fiziologicheskoe znachenie tormozheniya kholinesterazy mozhet byt' izucheno pri pomoshchi vvedeniya mechennogo C{sup 14} atsetata i analiza mechenogo atsetilkholina, nakopivshegosya v nervnykh tkanyakh, ili zhe putem ispol'zovaniya atsetil-C{sup 14}-kholina v kachestve substrata dlya opredeleniya In vitro stepeni tormozheniya kholiya- esterazy v tkanyakh otravlennykh zhivotnykh pri minimal'nom rastvorenii vo vremya analiza ingibitorov i fermentov.Nekotorye'uspekhi byli dostignuty pri pomoshchi mechennykh radioizotopami veshchestv v issledovanii

Electron-Exchange Reactions of Aromatic Molecules; Echanges d'Electrons de Molecules Aromatiques; Reaktsii ehlektronnogo obmena aromaticheskikh molekul; Reacciones de Intercambio Electronico en Moleculas Aromaticas

Energy Technology Data Exchange (ETDEWEB)

Malachesky, P. A.; Miller, T. A.; Layloff, T.; Adams, R. N. [University of Kansas, Lawrence, KS (United States)

1965-10-15

'shoe kolichestvo informacii otnositel'no skorosti mehanizma processov neorganicheskogo obmena jelektronov. V protivopolozhnost' jetomu chisto organicheskim sistemam udeljalos' dovol'no neznachitel'noe vnimanie. Skorost' gomogennogo jelektronnogo obmena (k{sub 0bm})i geterogennye konstanty skorosti dlja jelektrodnoj reakcii (k{sub jel}) byli izmereny lish' dlja neskol'kih ugle- vodorodov . Bylo izmereno k{sub 0bm} dlja razlichnyh aromaticheskih sistem, v tom chisle uglevodorodov, hinonov i nitrosoedinenij. Jeti izmerenija byli provedeny posredstvom jelektronnogo para- magnitnogo rezonansa (EPR) s perenosom izmerenij na smesi radikal'nyh ionov i ih mate- rinskih soedinenij. Nam takzhe udalos' izmerit' k0bm s takoj tochnost'ju, kotoraja pozvo- ljaet obnaruzhit' nebol'shie razlichija, vyzvannye, verojatno; molekuljarnoj strukturoj i sre- doj. Uglevodorodnye sistemy, podobnye antracenovomu/antracenovomu anionu, javljajutsja ves'ma bystrymi pri velichine k{sub 0gM} priblizitel'no 10{sup 8}-10{sup 9} litr mol{sup -i} sek{sup -1}. Nekotorye zame- shhennye aromaticheskie soedinenija, podobnye hinonam i nitrilam, takzhe javljajutsja ves'ma bystrymi. Odnako, kogda imeetsja sil'naja funkcija jelektronnogo akceptora, podobno nitro- gruppe v nitrobenzole, velichina k{sub 0gM} sokrashhaetsja na faktor 10. Predstavljaetsja vozmozhnym korrelirovat' izmenenija v k{sub obm} v serijah nitrobenzola s pomoshh'ju plotnosti neparnyh jelek- tronov po konstantam svjazi N{sup 14} spektra EPR. Krome togo, nitroaromaticheskie serii obna- ruzhivajut ochen' bol'shie razlichija v znachenijah k{sub 0b} m s rastvorjajushhej sistemoj. Jeti izmene- nija mozhno korrelirovat' blagodarja nedavnim issledovanijam jeffekta sol'vatacii na sverh- tonkie konstanty svjazi. V poslednee vremja Markus rassmotrel teoriju himicheskogo i jelektrohimicheskogo pere- nosa jelektronov i predlozhil korreljacii mezhdu znachenijami k{sub obm} i k{sub jel}. Nami special'no byl izmeren kjel dlja sistemy nitrobenzola v uslovijah, kotorye

Calcination of Radioactive Waste in Molten Sulphur; Calcination de Dechets Radioactifs dans le Soufre Fondu; 041a 0410 041b 042c 0426 0418 041d 0418 0420 041e 0412 0410 041d 0418 0415 0420 0410 0414 0418 041e 0410 041a 0422 0418 0412 041d 042b 0425 041e 0422 0425 041e 0414 041e 0412 0412 0420 0410 0421 041f 041b 0410 0412 041b 0415 041d 041d 041e 0419 0421 0415 0420 0415 ; Calcinacion de Desechos Radiactivos en Azufre Fundido

Energy Technology Data Exchange (ETDEWEB)

Winsche, W. E.; Davis, Jr., M. W.; Goodlett, Jr., C. B.; Occhipinti, E. S.; Webster, D. S. [E.I. Du Pont de Nemours and Co., Aiken, SC (United States)

1963-02-15

odnogo - pjati chasov dlja udalenija sernoj kisloty i ostavshejsja vody i dlja dal'nejshego kvl'ninirovanija i vosstanovlenija himicheskih soedinenij v sbrosnom sernom shlamme. Na jetih stadijah rasplavlennaja sera sluzhit v kachestve teploprovodnoj sredy, prepjatstvuet uvlecheniju radioaktivnyh tverdyh chastic obrazujushhimisja parami i gazami, a takzhe uletuchivaniju radioaktivnogo rutenija ne dopuskaja obrazovanija chetyrehokiela. Laboratornye opyty s ispol'zovaniem v kachestve pitajushhego rastvora koncentrirovannyh othodov vysokoj aktivnosti (1.3 x 10{sup 9} {gamma} c/(min)(ml), 2.0M Al(N0{sub 3}){sub 3}, i 1.5M HNO{sub 3}) pokazali, chto na jetih stadijah processa vyhodjashhimi gazami uvlekaetsja priblizitel'no lish' odna chast' na 100 000 chastej aktivnosti, soderzhashhejsja v ishodnom produkte. Po okonchanii vysokotemperaturnoj obrabotki sbrosnoj sernyj shlamm ohlazhdaetsja do 120 Degree-Sign C - 150 Degree-Sign C i slivaetsja v emkosti dlja okonchatel'nogo hranenija, v kotoryh on zatverdevaet. Stojkost' zatverdevshego sbrosnogo sernogo olamma protiv vozdejstvija vody byla ispol'zovana v kachestve mery jeffektivnosti jetogo metoda obrabotki, hotja avtory ne otkazyvajutsja ot zashhity sistemy emkostej protiv vozdejstvija vody. Iz imitirujushhih rastvorov, soderzhashhih Al(NO{sub 3}){sub 3} jeili nitraty rastvorennoj nerzhavejushhej stali s indikatornymi kolichestvami radioaktivnogo stroncija i cezija, a takzhe iz koncentrirovannyh vysokoradioaktivnyh othodov, soderzhashhih Al(NO{sub 3}){sub 3}, byli izgotovleny nebol'shie cilindry otverzhdennogo shlamma. Jeti cilindry podvergalis' dlitel'nomu vozdejstviju vody. Skorost' vyshhelachivanija opredeljalas' iz rascheta polnogo udalenija materiala iz poverhnostnogo sloja. Posle pervonachal'nogo perioda (6-8 nedel'), kogda vyshhelachivanie proishodit sravnitel'no bystro, nabljudaemaja skorost' vyshhelachivanija sostavljala 0,25 - 0,50 mm v god. (author)

New Frontiers for Non-Destructive Testing in the Nuclear Age; Perspectives des Essais Non Destructifs a l'Ere Nucleaire; ''Novye rubezhi'' nedestruktivnykh ispytanij v yadernyj vek; Nuevas Posibilidades de los Ensayos No Destructivos en la Era Nuclear

Energy Technology Data Exchange (ETDEWEB)

Ballard, D. W. [Sandia Laboratory Albuquerque, NM (United States)

1965-10-15

aplicarlas a la produccion si se quiere lograr un mayor nivel de seguridad en el empleo-del equipo nuclear. (author) [Russian] Posle vtoroj mirovoj vojny kolossal'no vozroslo chislo metodov nedestruktivnyh ispytanij chto mozhno v znachitel'noj stepeni ob'jasnit' tem, chto v jadernoj promyshlennosti pred{sup j}av- ljajutsja vse bolee strogie trebovanija k kachestvu i nadezhnosti oborudovanija. Slozhnost' sis- temy i obshhie rashody, svjazannye s povrezhdenijami, nastol'ko vozrosli, chto sushhestvuet na stojatel'naja neobhodimost' v razrabotke bolee jeffektivnyh metodov nedestruktivnyh ispy- tanij, a takzhe v ih ispol'zovanii na vsem protjazhenii proizvodstvennogo cikla. V nastojashhee vremja znachitel'no rasshirjajutsja vozmozhnosti primenenija horosho izvest- nyh metodov ispytanij, naprimer s pomoshh'ju radiografii, ul'trazvuka i jelektromagnitnyh kolebanij, dlja udovletvorenija vse vozrastajushhih trebovanij tehnicheskogo usovershenstvova- nija. Odnovremenno razrabatyvajutsja novye principy ispytanij special'no dlja togo , chto- by proverit' te trebovanija, kotorye pred{sup j}avljajutsja k staticheskim i dinamicheskim harakte- ristikam. Jeti bystrodejstvujushhie metody s vysokoj razreshajushhej sposobnost'ju, javljaju- shhiesja poistine ''novymi rubezhami'' nedestruktivnyh ispytanij, polozheny v osnovu nasto- jashhej raboty. V chislo novejshih metodov, kotorye rassmatrivajutsja v doklade, vhodit ispol'zovanie infrakrasnyh luchej dlja opredelenija prochnosti svarnyh soedinenij. Rassmatrivaetsja ispy- tanie struktur metodom kinoradiografii vo vremja vibracionnogo ispytanija s cel'ju izuche- nija ih dinamicheskogo povedenija. Drugoj oblast'ju, kotoraja imeet iskljuchitel'no vazhnoe zna- chenie dlja poluchenija nadezhnogo reaktornogo topliva, javljaetsja jeffektivnoe nahozhdenie mesta techi. Rassmatrivaetsja metod proverki zakljuchennyh v o''olochku komponentov, pri kotorom ispol'zuetsja radioaktivnyj gaz i kotoryj pozvoljaet izmerjat' skorosti utechki, sostavlja- jushhie 10

Action of Mercaptan and Disulfide in Hydrogen Atom Exchange Reactions; Action des Thioalcools et des Disulfures dans les Reactions d'Echange d'Atomes d'Hydrogene; Vozdejstvie merkaptanov i disul'fidov v reaktsiyakh obmena atoma vodoroda; Accion de los Mercaptanos y Disulfuros en las Reacciones de Intercambio del Hidrogeno Atomico

Energy Technology Data Exchange (ETDEWEB)

Cohen, S. G. [Brandeis University Waltham, MA (United States)

1965-10-15

radikalami, a takzhe fotohimicheskie i navedennye radiaciej bol'shoj jenergii reakcii mogut byt' katalizirovany ili zatormozheny bystrymi reakcijami obmena atoma vodoroda merkaptanov i disul'fidov. Navedennye pod vlijaniem sveta radikaly i senzitivirovannye benzofenonom reakcii dekarbonizacii aldegidov katalizirujutsja merkaptanami. Cepnaja reakcija posledovatel'nogo perenosa vodoroda R' + RCH = O -> RH + RC = O uskorjaetsja analogichnoj posledovatel'nost'ju perenosov atoma vodoroda s uchastiem slozhnyh soedinenij sery: R' + C{sub 6}H{sub 5}CH{sub 2}SH -> RH + C{sub 6}H{sub 5}CH{sub 2}S'; C{sub 6}H{sub 5}CH{sub 2}S + RCH = 0 -> C{sub 6}H{sub 5}CH{sub 2}SH + RC = 0. Fotovosstanovlenie benzofenona v 2-propanole vedet k obrazovaniju benzpinakola cherez necepnuju reakciju posredstvom radikalov (C{sub 6}H{sub 5}){sub 2}C-OH and (CH{sub 3}){sub 2}COH. Jeta reakcija zamedljaetsja i tormozitsja merkaptanom i disul'fidom, kotorye vnov' prevrashhajut radikaly v ishodnye materialy bystrymi reakcijami perenosa vodoroda, a sami reagenty regenerirujutsja v svoi sostojanija drugoj valentnosti, prichem kazhdaja molekula slozhnogo soedinenija sery prohodit bez himicheskih posledstvij cherez mnogie kvanty: (C{sub 6}H{sub 5}){sub 2}C-OH + AS' -> (C{sub 6}H{sub 5}){sub 2}C = O + ASH; (CH{sub 3}){sub 2}C-OH + ASH -> (CH{sub 3}){sub 2}C = 0 + AS'. Dokazatel'stvami takogo mehanizma mogut sluzhit': privedenie v sostojanie ravnovesija pervonachal'no prisutstvovavshego merkaptana ili disul'fida vo vremja tormozhenija; grozdevanie opticheski aktivnogo spirta vo vremja tormozhenija; obmen dejterija vo vremja tormozhenija. Analogichnoe tormozhenie nabljudaetsja pri obrazovanii odnogo tol'ko promezhutochnogo radikala, kak jeto proishodit v spirtovyh sostavah benzofenona - benzgidrola i acetofenona - {alpha} - metilbenzila. Tormozhenie slozhnymi soedinenijami sery putem takogo zhe mehanizma nabljudaetsja v navedennom gamma-luchami kobal'ta-60 prevrashhenii benzofenona v benzpinakol; naftalin ne proizvodit

Sb{sup III} - Sb{sup V} Exchange Reaction in Hydrochloric: Acid Solutions; Echange Sb{sup III}-Sb{sup V} dans des Solutions d'Acide Chlorhydrique; Reaktsiya obmena Sb(III) - Sb(V) v rastvorakh khloristovodorodnoj kisloty; Intercambio Sb{sup III}-Sb{sup V} en Soluciones de HCl

Energy Technology Data Exchange (ETDEWEB)

Kambara, T.; Yamaguchi, K.; Yasuba, S. [Shizuoka University, Shizuoka City (Japan)

1965-10-15

promezhutochnyh soedinenij pri obmene sur'my. Summiruja vysheupomjanutye rezul'taty, mozhno skazat', chto sushhestvovanie maksimal'noj skorosti obmena pri koncentracii HCl okolo 2,0 M v oblasti nizkoj koncentracii HCl mozhet byt', po-vidimomu, prekrasno ob'jasneno. (author)

Applications of Fluorine-18 in Biological Studies with Special Reference to Bone and Thyroid Physiology; Emploi du Fluor-18 dans des Études Biologiques, Notamment sur la Physiologie des Os et de la Thyroïde; ИСПОЛЬЗОВАНИЕ ФТОРА-18 В БИОЛОГИЧЕСКИХ ИССЛЕДОВАНИЯХ С УДЕЛЕНИЕМ ОСОБОГО ВНИМАНИЯ ВОПРОСАМ ФИЗИОЛОГИИ КОСТЕЙ И ФИЗИОЛОГИИ ПИТОВИДНОЙ ЖЕЛЕЗЫ; Aplicaciones del Fluor-18 en Estudios Biologicos, con Especial Referencia a la Fisiologia del Esqueleto y de la Tiroides

Energy Technology Data Exchange (ETDEWEB)

Anbar, M. [Weizmann Institute of Science (Israel); IAEC Soreq Research Establishment, Rehovot (Israel)

1963-03-15

4} estimula la accion inhibidora que ejercen sobre la captacion de yodo los iones hierro, cobre, cinc, cadmio, fluoruro, tiocianiato y otros, demostrando que en ella interviene la funcion de captacion. En una serie analoga de experimentos, se encontro que los compuestos sulfhidrilicos y las azidas incrementan la captacion de fluoroborato, aunque disminuyen la captacion total de yodo. Seguidamente, se demostro que la funcion de captacion es menos radiosensible que las funciones de formacion y liberacion de tiroxina. Otra aplicacion muy distinta de los iones fluoroborato marcados con {sup 18}F fue la localizacion de tumores cerebrales por exploracion direccional de coincidencias en la que se aprovecha la baja permeabilidad para estos iones de la barrera sangre- cerebro intacta. Se prepararon agentes de quelacion fluoroaromaticos marcados con {sup 18}F y se aplicaron a problemas de fisiologia de tejido oseo. Para estudiar la permeabilidad a traves de membranas biologicas, se emplearon colorantes aromaticos vitales marcados con {sup 18}F. Se han preparado antimeiabolitos que contienen fluor, marcados con {sup 18}F, entre otros, el 5-fluorouracilo y el acido fluoroorotico y se han aplicado al estudio de problemas fisiologicos e investigaciones sobre el cancer. (author) [Russian] V techenie poslednih treh let ftor-18 primenjaetsja v nashej laboratorii dlja razlichnyh biologicheskih i medicinskih issledovanij. Razrabotany metody poluchenija ftora v rezul'tate reakcij s O{sup 16} (p, n), O{sup 15} (H{sup 3}, p), i F{sup 18} (n, 2 ,). Soedinenija, mechennye radioaktivnym ftorom, byli poducheny metodom izotopnogo obmena sinteza, mechenija otdachej i uderzhivaniem ftora vo ftoroorganicheskih soedinenijah v rezul'tate reakcii (p,2 p). Razrabotana special'naja tehnika scheta nizkogo urovnja aktivnosti dlja raboty s malymi aktivnostjami indikatornyh kolichestv organicheskih ftoristyh soedinenij. Iony ftora-18 byli ispol'zovany pri izuchenii fiziologii kostej. Bylo obnaruzheno

Radioisotopes and Radiation in Animal and Plant Insect Pest Control; Emploi des radioisotopes et des rayonnements dans la lutte contre les insectes nuisibles aux plantes et aux animaux; Ispol'zovanie radioizotopov i radiashchi v bor'be s nasekomymi-vreditelyami rastenij i zhivotnykh; Utilizacion de los radioisotopos y de las radiaciones en la lucha contra los insectos nocivos para las plantas y los animales

Energy Technology Data Exchange (ETDEWEB)

Andreev, S. V.; Martens, B. K.; Samojlova, V. A.; Molchanova, Z. I. [Vsesoyuznyj Institut Zashchity Rastenij, Leningrad, SSSR (Russian Federation)

1963-09-15

. Krome togo, metod daet vozmozhnost' issledovat' slozhnejshij kompleks voprosov parazitizma i khishchnichestva (voprosy izucheniya pishchevykh tsiklov promekhutochnogo pitaniya i khemataksisa). Primenenie metoda samomarkirovki polevykh gryzunov s pomoshch'yu radioaktivnykh primanok pozvolilo ustanovit' razmery pishchevykh arealov. Ispol'zovanie pestitsidov, sintezirovannykh o radioaktivnymi izotopami, v sochetanii s metodom radiokhromatografii, flyuorometrii i drugimi pozvolilo issledovat' slozhnejshie biokhimicheskie protsessy, protekayushchie v rasteniyakh i nasekomykh pod vliyaniem toksikantov. Na primere fosfornoorganicheskikh soedinenij tipa tiofosa i metafosa byla ustanovlena skorost' gidroliza ehtikh insektitsidov v zavisimosti ot fazy razvitiya rasteniya i ego fiziologicheskogo sostoyaniya, a takkhe uslovij vneshnej sredy. Opredelena dlitel'nost' sokhraneniya ostatochnykh kolichestv toksikantov na sel'skokhozyajstvennoj produktsii v zavisimosti ot srokov khimicheskikh obrabotok. S pomoshch'yu radioaktivnykh izotopov vyyavleny osobennosti metaboliticheskikh protsessov, ustojchivykh i neustojchivykh k gerbitsidam rastenij. Vnesenie v pestitsidy izotopov s korotkim periodom poluraspada v indikatornykh kolichestvakh daet vozmozhnost' proizvodit' otsenku kachestva obrabotki semennogo materiala i posevov sel'skokhozyajstvennykh rastenij pestitsidami pri ispol'zovanii razlichnykh sistem opryskivatelej, a takzhe opredelyat' optimal'nye normy ikh raskhoda. Putem vozdejstviya ioniziruyushchikh izluchenij na ehntomopatogennye mikroorganizmy (Beauverla basslana Unill.) dokazana vozmozhnost' povysit' ikh virulentnost' v tselyakh uluchsheniya mikrobiologicheskogo metoda bor'by s vrednymi nasekomymi. Sterilizutatsee i letal'noe dejstvie ionizirudtsikh izluchenij mozhet byt' ispol'zovano kak aktivnoe sredstvo bor'by s vrednymi nasekomymi. Primeneniem gamma radiatsii ustanovleny sterilizukhkhtsie dozy dlya ryada nasekomykh-vreditelej zapasov (Calandra granarla L., Acanthoscelides

Production of Xenon Compounds by the Beta Decay of Iodine in Iodine Compounds; Production de Composes du Xenon par Desintegration Beta de l'Iode dans les Composes Iodes; 041f 0420 041e 0418 0417 0412 041e 0414 0421 0422 0412 041e 0421 041e 0415 0414 0418 041d 0415 041d 0418 0419 041a 0421 0415 041d 041e 041d 0410 041f 041e 0421 0420 0415 0414 0421 0422 0412 041e 041c 0411 0415 0422 0410 - 0420 0410 0421 041f 0410 0414 0410 0419 041e 0414 0410 0412 0419 041e 0414 0418 0421 0422 042b 0425 0421 041e 0415 0414 0418 041d 0415 041d 0418 042f 0425 ; Produccion de Compuestos de Xenon por Desintegracion Beta del Yodo de Compuestos Yodados

Energy Technology Data Exchange (ETDEWEB)

Perlow, G. J.; Perlow, M. R. [Argonne National Laboratory, Argonne, IL (United States)

1965-04-15

Messbauera v He{sup 129}. Pervoe vozbuzhdennoe sostojanie v He{sup 129} imeet J{sup {pi}} = 3+/2, T{sub Vulgar-Fraction-One-Half} = 10{sup -9} * sek i ono lezhit na 40 kjev vyshe |+osnovnogo sostojanija. Ono razmnozhaetsja raspadom iz 1,6 * 10{sup 6} J{sup 129}. Jeffekt Messbauera gamma-luchej s jenergiej 40 kjev mozhno legko nabljudat' s mnogimi istochnikami i poglotiteljami v jeksperimentah, prodelannyh pri 4,2 Degree-Sign K. Jelektro-kvadrupol'noe rasshheplenie vozbuzhdennogo sostojanija imeet rezul'tatom dve linii absorbcii, esli ispol'zuetsja smeshhenie Dopplera dlja skennirovanija spektra. Razdelenie mezhdu linijami harakterizuet jelektronnuju konfiguraciju v ksenone i chasto nedvusmyslenno opredeljaet strukturu. ti pervyh jeksperimentah ispol'zovalsja istochnik NaJ{sup 129} s poglotiteljami iz setchatogo gidrohinona, Na{sub 4}XeO{sub 6}, HeF{sub 4} i HeF{sub 2}. Odnolinejnye spektry nabljudalis' dlja klatrata i peksenata, a dvuhlinejnye spektry - dlja ftoristyh soedinenij. Edinichnaja linija ukazyvaet, chto v istochnike J {yields} XeO javljaetsja izojelektronnym dochernim produktom. Kogda v kachestve istochnika ispol'zovalos' soedinenie Na{sub 3}H{sub 2}JO{sub 6} s setchatym poglotitelem, neotdajushhaja frakcija uvelichilas' na faktor 3, vlecha za soboj usilenie svjazi. KJO{sub 4} takzhe daet odnu, no neskol'ko menee intensivnuju, liniju. SNaJO{sub 3} v kachestve istochnika i s setchatym poglotitelem rasshheplenie nabljudalos' s ukazaniem na to, chto JO{sub 3}{sup -} {yields} HeO{sub 3}. Jeto bylo podtverzhdeno blagodarja nabljudeniju za identichnym rasshhepleniem v HeO{sub 3} poglotitele pri ispol'zovanii istochnika KJO{sub 4}. Jeksperiment s KJCl{sub 4} - N{sub 2}O v kachestve istochnika i setchatym poglotitelem pokazal rasshheplenie neskol'ko men'shee, chem v XeF4. Zdes' JC14 -HeSl{sub 4} . Ispol'zuja vyravnennye kristally KJCI{sub 4} N{sub 2}O i delaja kolichestvennye izmerenija plotnosti, bylo ustanovleno, chto kvadratno-ploskostnaja struktura JCl{sub 4

Studies of the Solid and Liquid Phases of HF, HCl and HBr by Slow-Neutron Inelastic Scattering; Etude des Phases Solide et Liquide de HF, HCl Et HBr par la Diffusion Inelastique des Neutrons Lents; 0418 0417 0423 0427 0415 041d 0418 0415 0422 0412 0415 0420 0414 042b 0425 0418 0416 0418 0414 041a 0418 0425 0424 0410 0417 HF, HCl I HBr 0421 041f 041e 041c 041e 0429 042c 042e 041d 0415 0423 041f 0420 0423 0413 041e 0413 041e 0420 0410 0421 0421 0415 042f 041d 0418 042f 041c 0415 0414 041b 0415 041d 041d 042b 0425 041d 0415 0419 0422 0420 041e 041d 041e 0412 ; Estudio de las Fases Solida y Liquida del HF, HCl Y HBr por Dispersion Inelastica de Neutrones Lentos

Energy Technology Data Exchange (ETDEWEB)

Boutin, H. [Picatinny Arsenal, Dover, NJ (United States); Brookhaven National Laboratory, Upton, NY (United States); Safford, G. J. [Brookhaven National Laboratory, Upton, NY (United States)

1965-06-15

}asneno bolee slaboj stepen'ju associacii, kotoruju mozhno ozhidat' v svjazi s umen'sheniem otricatel'nogo zarjada aniona. Sistematicheskoe izuchenie jetih spektrov v razlichnyh fazah i pri razlichnyh temperaturah pozvoljaet provesti razlichie mezhdu harakteristikami nizkokachestvennyh dvizhenij reshetki ili cepi s vodorodnoj svjaz'ju i harakteristikami teh nizkochastotnyh dvizhenij, kotorye zatragivajut vzaimodejstvija blizhajshego soseda ili blizkodejstvujushhie sily. Rezul'taty jetih izmerenij soglasujutsja s imejushhimisja dannymi, poluchennymi s pomoshh'ju infrakrasnyh luchej, i pokazyvajut, chto vodorodnaja svjaz' javljaetsja sushhestvennym faktorom ob{sup j}asnenija spektrov tverdyh faz kak HCl, tak i NVg. Odnako jeti dannye ne soglasujutsja s teoriej, kotoraja ob{sup j}asnjaet tverdye fazy jetih soedinenij tol'ko s tochki zrenija prostyh dipol'nyh sistem ili s tochki zrenija dal'nih vzaimodejstvij, zatragivajushhih dipol'nyj moment odnoj otdel'noj sostavnoj chasti, vzaimodejstvujushhej so srednim jelektricheskim polem. (author)

Reactions of Hot Hydrogen Atoms with Ethylene. The Role of Excited Ethyl Radicals as Intermediate Products; Reactions des Atomes Chauds d'Hydrogene avec l'Ethylene. Le Role des Radicaux Ethyle Excites Comme Produits Intermediaires; Reaktsiya goryachikh atomov vodoroda s ehtilenom. Rol' vozbuzhdennykh ehtil'nykh radikalov kak promezhutochnykh produktov; Reacciones de Atomos Calientes de Hidrogeno con Etileno Papel de los Radicales Etilicos Excitados como Productos Intermedios

Energy Technology Data Exchange (ETDEWEB)

Dzantiev, B. G.; Shvedchikov, A. P. [Institut Himicheskoj Fiziki AN SSSR, SSSR (Russian Federation)

1965-04-15

.datchikov (katarometr) i protochnyj schetchik Gejgera). Pokazano, chto spektr mechenyh i nemechenyh produktov v obluchaemom jetilene znachitel'no otlichaetsja. Osnovnymi nemechenymi produktami javljajutsja C{sub 2}H{sub 2}, C{sub 2}H{sub 6}, C{sub 4}H{sub 10} i uglevodorody >C{sub 4}; vyhod H{sub 2} mal. Osnovnymi nemechenymi produktami javljajutsja HT, C{sub 2}H{sub 3}T i. C{sub 4}H{sub 9}T, vyhod C{sub 2}H5T i osobenno C{sub 2}HT neznachitelen. Vyhody mechenyh soedinenij zavisjat ot vvedenija dobavok v jetilen (ammiak, gelij, jod), vida litijsoderzhashhego soedinenija, struktury misheni. Ponizhenie temperatury s 50 do -78 Degree-Sign malo vlijaet na raspredelenie mechenyh produktov, odnako, pri perehode k tverdomu jetilenu (-196 Degree-Sign C) nabljudaetsja fazovyj jeffekt: umen'shaetsja vyhod HT i C{sub 4}H{sub 9}T i uvelichivaetsja aktivnost' materinskogo soedinenija C{sub 2}H{sub 3}T. Pokazano, chto pri radiolize C{sub 9}H{sub 4} i ego smesej s ammiakom otnoshenie C{sub 2}H{sub 6}/C{sub 4}H{sub 10} ravno 1,0 {+-} 0,3, chto ne soglasuetsja s kanonicheskoj shemoj dlja reakcij disproporcionirovanija i rekombinacii teplovyh jetil'nyh radikalov (C{sub 2}H{sub 6}/C{sub 4}H{sub 10} = 0,2 {+-} 0,1). Na osnovanii dannyh po vlijaniju dobavok gelija i temperatury na vyhod C{sub 2}H{sub 6} i C{sub 4} Nju pri radiolize C{sub 2}H{sub 4} i pri fotolize smesej C{sub 2}H{sub 4} -HJ sformulirovano predstavlenie ob obrazovanii vozbuzhdennyh jetil'nyh radikalov C{sub 2}H{sub 5}*. Poslednie poluchajutsja za schet prisoedinenija gorjachih atomov vodoroda (generiruemyh radioliticheski ili fotoliticheski) k jetilenu: H* + C{sub 2}H{sub 4} = C{sub 2}H{sub 5}*. Pokazano, chto C{sub 2}H{sub 5}*-radikal legko vstupaet v reakciju otryva C{sub 2}H*{sub 5} + RH = C{sub 2}H{sub 6} + R, chto ob'jasnjaet ''izbytochnoe'' kolichestvo jetana, obrazujushhegosja pri radiolize jetilena. (author)