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1996-12-31
Since 1977 the Brazilian electric sector has experienced an institutional and economic crisis.The new regulations for this sector and particularly the proposal for restructuring the electric utilities in Sao Paulo are presented 3 refs., 3 tabs.; e-mail: sguerra at fem.unicamp.br
Education digital libraries management: Sharing the experience of UNICAMP education faculty
2008-01-01
Purpose - This work aims to report the experience of implementing a university digital library by introducing all the technical/administrative and scientific production in the education field. Design/methodology/approach - The paper describes the process of conception, information architecture, the steps and methodology for structuring and establishing of the Digital Library of the Faculty of Education of the State University of Campinas (BDE - FE/UNICAMP), with the partnership of the UNICAMP Libraries System (SBU/UNICAMP), which manages the Nou-Rau software and stores the Digital Library of UNICAMP (BDU). It also identifies the skills and abilities the information professional must have, concerning the definition of criteria for the evaluation and selection of documents to be scanned, and...
1996-12-31
The radiation protection conditions in the Service or Radiotherapy/CAISM - UNICAMP are studied. A program of radiation protection composed by a radiation planning for the service, an area and individual monitoring program and a checking program is presented. Geiger Mueller detectors, ionization chambers, specific check lists and the results of about five years of individual monitoring are used in the implementation of the program 6 refs.
2008-07-01
Due to the importance and the need in studies with heavy and extra heavy petroleums and their residues, it was designed and built up by the oil research group of LOPCA/LDPS/FEQ/UNICAMP, in partnership with the Laboratory of Valuation Processes of CENPES / PETROBRAS, a pilot plant of falling film molecular distiller (national prototype), where some specific operational facilities were introduced. This project resulted in a suitable system for distillation of products of high molecular weight and thermally sensitive, without degradation of them. This work aims the achievement of distillate fractions of atmospheric residue 400 deg C+, using the new molecular distillation equipment. The experiments were carried out according to factorial design to assess the significant process variables in the molecular distillation prototype. The results showed that the evaporator temperature has high influence on the process and the feed flow rate has minimum influence, as it is desired. Additionally, the equipment showed easy handing operation, high operational stability and results varying around 1%. (author)
Cosmoeducao: uma proposta para o ensino de astronomia
Entende-se por cosmoeducao o desenvolvimento vivencial da unidade homem-cosmo. Este conceito norteado pela psicologia transpessoal, que estuda o ser humano em sua totalidade, onde suas relaes ecolgicas e csmicas so de grande importncia. Constata-se uma necessidade latente no ser humano moderno em resgatar uma relao holstica com o Universo. Neste trabalho exploramos meios de cultivar a conscincia de que o ser humano constitui parte integrante do cosmo e se relaciona com este com o objetivo de promover em si uma percepo ambiental mais ampla. Nossa hiptese de trabalho inicial foi que o ensino de contedos bsicos em astronomia realizado atravs de uma abordagem holstica, que incorpore prticas vivenciais correlacionadas queles contedos, pode despertar no indivduo sua identidade csmica. O mtodo que utilizamos o fenomenolgico e o universo desta pesquisa um grupo de estudantes da disciplina de Astronomia (Curso de Licenciatura em Geografia/UFRN), onde realizamos observao participante, entrevistas, depoimentos e as prticas vivenciais mencionadas. Neste caso estamos desenvolvendo e adaptando exerccios de algumas tcnicas teraputicas de psicologia transpessoal, que um de ns (LALM) tem aplicado no contexto clnico, para trabalhar aspectos cognitivos envolvidos naquele processo de conscientizao csmica. Resultados parciais claramente referendam a hiptese inicial. Um resultado a destacar fruto de uma dinmica de representao corporal interiorizada do eclipse lunar, envolvendo um pequeno grupo daqueles estudantes, na qual contedos mticos afloraram de maneira espontnea e contundente para todos, sugerindo ressonncia, ou pelo menos isomorfismo, entre o macro e o microcosmo. Este e outros resultados so discutidos em detalhe neste trabalho. (PPGECNM/UFRN; PRONEX/FINEP; NUPA/USP; Temticos/FAPESP).
Restructuring the PROALCOOL: Brazilian Program for Alcohol Fuel; Reestruturacao do PROALCOOL
1996-12-31
In 1996, the Brazilian government proposed resuming the investments for the PROALCOOL program. The possibility of restructuring this program considering its strategic character due to its economic,social and environmental aspects is analyzed 10 refs., 2 figs., 1 tab.; e-mail: bajay at fem.unicamp.br; berni at fem.unicamp.br
Research on hydrogenated amorphous silicon and related alloys for photovoltaiv applications
1984-01-01
An overview of the main activities on amorphous materials of photovoltaic interest performed at the Photovoltaic Conversion Laboratory at UNICAMP is presented. The laboratory is actively engaged in a research program concerning hidrogenated amorphous semiconductors and devices. (MWO)
P02-337 - Melancholy turning into ashes the fire of hysteria
2010-01-01
Objectives: To discuss the paradigm of melancholy in hysteria. Methods: case report of M., a 45 year-old woman, who is under psychotherapy and psychiatric treatment at the General Hospital of the University of Campinas (HC Unicamp). Results: K. is a 45 year-old divorced mother and former teacher, who started psychotherapy and psychiatric treatment at HC Unicamp in 2007, two years after the death of her father.Since such loss,K. made several violent suicide attempts: she jumped from the balcony of her apartment, took an overdose of medications, and set fire to her body in front of the mirror, which caused permanent scars. During both the psychotherapy sessions and the psychiatric consultations, K. frequently expressed how her life had lost its meaning after the death of her father. She ment...
1999-07-01
This paper describes the experiment developed at the Energy Department of the Faculdade de Engenharia Mecanica of UNICAMP, Brazil, aiming the surveillance of the Piracicaba and Capivari, state of Sao Paulo, Brazil, basin rivers photovoltaic potential. The paper also presents the first results obtained.
2000-07-01
This paper describes fast pyrolysis process from a continuous air fluidized bed reactor utilizing sugarcane bagasse, trash, and elephant grass. The experiment was conducted by UNICAMP (FEAGRI and NIPE) and the Copersucar Technology Center-CTC in Piracicaba-SP, Brazil. The process utilizes a atmospheric bubbling fluidized bed in pilot-plant-scale, combined with conventional systems to recovery of solids (pulverized charcoal) and Bio-Oil (pyrolysis liquid). The fast pyrolysis system was designed and built by UNICAMP, Copersucar Technology Center, and Termoquip Alternative Energy Ltda. The project is currently underway in its final phase to assembly and to adjust the experimental and instrumental arrangement. The experimental strategy will allow to optimize the studied parameters. The mathematical modelling will allow to obtain the temperature, product concentration, and velocity profiles, using a computational fluid dynamics technique named CFD to each experimental test condition. The ultimate goal of this research project is to develop alternative technologies to economically produce charcoal and Bio-Oil. A feasibility study, considering technical and environmental aspects will also be conducted.(author)
1999-09-01
Currently, high resolution computed tomography (HRCT) of the lung is the method of choice for diagnostic evaluation of patients suspected of having diffuse lung disease, due to its non invasiveness, fast execution, not requiring contrast agents and high anatomic resolution. The purpose of this paper is to describe and illustrate the basic findings of lung diseases as seen on HRCT, and list their differential diagnosis. The example are based on 40 selected cases of the Department of Radiology of the School of Medicine of the State University of Campinas (UNICAMP), Sao Paulo, Brazil.(author)
2010-01-01
Study design:Radiographic analysis of sagittal spinal alignment of paraplegics in a standing position under surface neuromuscular electrical stimulation (NMES).Objectives:Describing the radiographic parameters of the sagittal spinal alignment of paraplegics going through a rehabilitation program with NMES.Setting:The University Hospital's Ambulatory (UNICAMP), Campinas, Sao Paulo, Brazil.Methods:Panoramic X-ray images in profile were taken for 10 paraplegics. All patients participated in the rehabilitation program and were able to perform gait through NMES of the femoral quadriceps muscles. The radiographic parameters used for the analysis were the same as those described in the literature for healthy people. The results were didactically organized into three groups: anatomical shape of th...
1998-12-31
The rational use of energy is becoming a matter of great importance and interest on every sectors of society. Optimization techniques are efficient tools to get rational operations of energy. This paper presents an optimization model applied to a part of the CAESA public system water supply in Macapa, considering a daily programming horizon. CAESA is the company of water and drain of Amapa. The results achieve show a reduction potential up to 25% in actual electrical energy use of the studied system. (author) 7 refs., 8 figs., 6 tabs.; e-mail: cynthia e correia at fem.unicamp.br
2005-07-15
The present paper describes the synthesis of crystalline zirconium hydrogen phosphate by direct precipitation and its intercalation with pyridine and n-butylamine. The simple experiment was tested in the undergraduate inorganic chemistry laboratory course for chemistry students at IQ-UNICAMP using inexpensive reagents. The materials were characterized by powder X-ray diffraction and infrared analyses in order to obtain detailed information of the solid structure changes as a result of the intercalation process. Pyridine and n-butylamine are focused in this work as clear and elucidative examples leading to acid-base interactive processes that result in the well-formed infinite sequence of inorganic lamellar structures. (author)
2005-01-01
The present paper describes the synthesis of crystalline zirconium hydrogen phosphate by direct precipitation and its intercalation with pyridine and n-butylamine. The simple experiment was tested in the undergraduate inorganic chemistry laboratory course for chemistry students at IQ-UNICAMP using inexpensive reagents. The materials were characterized by powder X-ray diffraction and infrared analyses in order to obtain detailed information of the solid structure changes as a result of the intercalation process. Pyridine and n-butylamine are focused in this work as clear and elucidative examples leading to acid-base interactive processes that result in the well-formed infinite sequence of inorganic lamellar structures. (author)
2010-01-01
The present work was carried out with the aim to investigate some properties of an extracellular fructofuranosidase enzyme, with high transfructosylating activity, from Candida sp. LEB-I3 (Laboratory of Bioprocess Engineering, Unicamp, Brazil). The enzyme was produced through fermentation, and after cell separation from the fermented medium, the enzyme was concentrated by ethanol precipitation and than purified by anion exchange chromatography. The enzyme exhibited both fructofuranosidase (FA) and fructosyltransferase (FTA) activities on a low and high sucrose concentration. With sucrose as the substrate, the data fitted the MichaellisMenten model for FA, showing rather a substrate inhibitory shape for fructosyltransferase activity. The K m and v max values were shown to be 13.4g L...
Optimization of the implosion phase of TC-I by light emission analysis
1989-01-01
The best operation condition on the field-reversed theta-pinch TC-I at UNICAMP is studied by analysis of the helium-plasma light emission and electromagnetic signals observed during the preionization and implosion phase of FRC plasma. The TC-I device can be operated with a crowbar switch on the preionization and main capacitor banks, in order to fix the number of oscillations as well as the time interval between the end of the preionization and the main discharge phase. A detailed study of the plasma implosion has been carried out by changing the above parameters and also the working gas pressure by using a photodiode, a visible spectrometer, magnetic probes, a Faraday cup and a streak camera. (orig.)
A method for exergy analysis of sugar cane bagasse boilers
1998-03-01
This work presents a method to conduct a thermodynamic analysis of sugarcane bagasse boilers. The method is based on the standard and actual reactions which allows the calculation of the enthalpies of each process subequation and the exergies of each of the main flowrates participating in the combustion. The method is presented using an example with real data from a sugarcane bagasse boiler. A summary of the results obtained is also presented together based on the 1 st Law of Thermodynamics analysis, the exergetic efficiencies, and the irreversibility rates. The method presented is very rigorous with respect to data consistency, particularly for the flue gas composition. (author) 11 refs., 1 fig., 6 tabs.; e-mail: cortez at agr.unicamp.br
2010-01-01
Objectives: To determine the outcome of patients who underwent ECT in a Brazilian General Hospital between 1993 and 2007. Methods: Telephone contact with all patients (or their relatives) who were submitted to ECT during psychiatric hospitalization in HC-Unicamp-Brazil. Data were compiled for statistical analysis at SPSS. Results: There were 53 successful telephone contacts (33.9% of 153 patients who underwent ECT). Losses were due to changes of telephones/addresses. No refuses occurred. The mean time between the procedure and the contact was 55.4 months (3-170). Twenty patients (37.3%) and 37 relatives (69.8%) were interviewed. Most were women (60.4% n=32), 4 were inpatients by the occasion of the call and 4 died. The mean age was 42.9+/-19.4. The assessments of current mental state by pa...
2001-07-01
The project aims the implantation of a management program, for the maintenance of the conventional X-ray equipment at HUCFF. It has been implemented through the training of the electronic technicians who work at the Hospital. Essential courses were organized such as: Basics of Radioprotection, Radiographs Techniques, and Maintenance of equipment of X-Rays. Equipment: a library with the schemes of the equipment is being assembled in collaboration with UNICAMP. In order to manage the process, a software was created using the tools of the total quality for control of the maintenance. Preliminary tests: the equipment and their working conditions were evaluated, as well as the level of the employees' satisfaction with their use. The creation of a new routine for maintenance seeks to assist the demands of the new legislation in Brazil 5, and also reduce the costs to improve the quality of the images in the Radiodiagnostic Service. (author)
2009-08-15
This paper analyzes both the carbon fiber-based development for uranium centrifuges and the research project that supports its development effort over time. The carbon fibre-based engineering properties make it a valuable supply for high technological products, such as uranium ultracentrifuge. There is no production of such fibers in Brazil. Its trade is subject to international market restrictions due to carbon fibers' dual applications. The Centro Tecnologico da Marinha em Sao Paulo (CTMSP), the Universidade de Campinas (UNICAMP), the Universidade de Sao Paulo (USP), the RADICIFIBRAS Company, and the Financiadora de Estudos e Projetos (FINEP), which is responsible for the project financial support, established a partnership aiming the development of a domestic polyacrylonitrile (Pan)-based carbon fiber industry. Such alliances or technological partnerships are best known in developed countries, such as USA and Japan, as Cooperative Research or Research Joint Ventures (RJV). (author)
2009-01-01
This paper analyzes both the carbon fiber-based development for uranium centrifuges and the research project that supports its development effort over time. The carbon fibre-based engineering properties make it a valuable supply for high technological products, such as uranium ultracentrifuge. There is no production of such fibers in Brazil. Its trade is subject to international market restrictions due to carbon fibers' dual applications. The Centro Tecnologico da Marinha em Sao Paulo (CTMSP), the Universidade de Campinas (UNICAMP), the Universidade de Sao Paulo (USP), the RADICIFIBRAS Company, and the Financiadora de Estudos e Projetos (FINEP), which is responsible for the project financial support, established a partnership aiming the development of a domestic polyacrylonitrile (Pan)-based carbon fiber industry. Such alliances or technological partnerships ...
2008-07-01
In the context of the national petroleum industry, it is interesting to keep the production of the paraffinic lubricant oil type I, which implies in the identification of new loads to ensure the feeding of the existing units. Therefore, it is important to carry out carefully the characterization of the oils, defining its potential for fuel, asphalt and lubricant. Aiming to introduce in the characterization and evaluation of petroleum for lubricant, carried out by PETROBRAS/CENPES, information of basic oils, more similar to industrial oils, was built up in the Laboratory of Process Separation Development - LDPS of UNICAMP/FEQ, a deasphalting pilot unit. In this work, the deasphalting process of a vacuum residue of Brazilian petroleum is simulated, using Aspen Plus{sup R} simulator, in order to remove asphaltenes, resins and other heavy components of vacuum residue. The simulations were carried out considering the configuration of the pilot plant, evaluating the extraction in near-critical operational condition applied to a petroleum, using propane as the solvent. The extraction efficiency and the solvent power were evaluated considering variations in temperature, pressure and in the solvent/feed ratio in order to obtain yields with more efficiency in the production of deasphalted oil (DAO), what means more asphaltene removal. (author)
Study of metal removal by square Wetland System with Eleocharis SP. using SR-XRF
2007-07-01
The pollution of the water resources for metals, results of different economic activities. The objective of the present study was to use the SR-TXRF technique to evaluate the performance of Wetland system cultivated with Eleocharis sp. installed at FEAGRI-UNICAMP, in the metal removal. The metals analyzed were Cr, Mn, Fe, Zn and Pb. Samples of the wastewater in the exit, Eleocharis sp. leaf and medium boulder were collected during 20 weeks consecutively. The system was operated with different outflows and hydraulic detention times (HDT) as: 600 L.day{sup -1} (HDT 2 days), 400 L.day-1 (HDT 3 days), 300 L.day{sup -1} (HDT 4 days) and 200 L.day{sup -1} (HDT 6 days). The main source of metal removal was medium boulder with efficiency varying 30.1% for Cr and 98.9% for Pb, independent of the hydraulic detention time (HDT) used. The efficiency of the wetland in the Cr removal varied between 39.6 and 98.7%, and for Mn was higher than 81.6%. For Fe the performance was higher than 70.6% and for Cu the efficiency varied between 88.4 and 99.7 %, while for Pb the variation was 67.5 to 98.4 %. The wetland system with Eleocharis sp were in agreement with CONAMA legislation concern to Fe, Cu and Zn removal and for HDT of 2, 3, 4 and 6 days (HDT), moreover for Mn was necessary 4 and 6 days (HDT) and for Cr and Pb 6 days (HDT). (author)
2000-07-01
The utilization of the biomass to generate carbonaceous materials of great application for many industrial areas is emphasized in Brazil in relation to the use of the wood focusing on great promoting of energy and carbon supply, specially for carbothermic reduction. However, the critical constraints involve the huge exploitation of native forest and the constant need of increment of the enormous areas for replanted forests. In both situations, the economic and ecological aspects have to be considered. Our country, with a potentiality of 30 per cent of the world production of sugar cane,, has a production of sugar cane bagasse around 85 million tons, which it is utilization for energy cogeneration does not exceed 75 per cent of thi total amount. This way, could be very attractive the utilization of bagasse surplus for other areas such as carbothermic reduction of quartz into silicon. Therefore, the objective of the present research, that will be an integrating part of the QITS project (Quartz Industrial Trade System) - conducted by the Laboratory of Integrated Quartz Cycle of the UNICAMP (LIQC), SP, Brazil in partner ship with UNU/IAS (The United Nations Univ./ Inst. of Advanced Studies); is to study the chemical composition of the charcoal derived from bagasse. X-ray fluorescence spectrometer was used for chemical analysis of bagasse charcoal. The charcoal samples were obtained from pyrolysis using two types of reactor: rotary drum and static thermo reactor, where bulk temperature reached 400 to 550 deg C. After this pyrolysis procedure, were carried out heat treatment temperature in the range of 750 deg C in such samples. The impurity measurements in this type of charcoal showed quartz as the majority impurity, followed by considerable amounts of others elements such as K{sub 2}O, Al{sub 2}O{sub 2}, FeO{sub 2}, according to the pyrolysis process utilized. (author)
A unified methodology for hazardous and radioactive waste management
2007-07-01
In developing countries, the shortage of financial resources and the lacking in training and in suitable technical solutions are among the causes of the difficulties in planning a safe waste management - WM. In order to help managing wastes in an environmentally-friendly manner, technical and administrative procedures should be implemented. A methodology that systematizes the predisposal management activities of radioactive and nonradioactive wastes was developed (a doctoral thesis at UNICAMP), adopting an approach based on the integration of all steps involved. It is presented, through Data Flow Diagrams that show the flow of data between external entities, like generators, WM service providers, transporters and regulatory bodies, how the data move from a process to another, as well as data stores, where data are up-dated and retrieved. The methodology can be briefly described through a process of waste identification, characterization and classification using available data about wastes and applicable standards. Knowing the local infrastructure for waste treatment, conditioning and storage, it is verified the necessity of using of centralized facilities. In this case, the generator should prepare the waste package in accordance with the acceptance criteria from that facility and submit a transport plan to the regulatory body before transferring the waste package. A WM Program, approved by the competent bodies, should be complied with by generator. The methodology intends to be a facilitator tool, assisting the user in decisions related to generation, treatment, conditioning, storage and transport, as well as in updating the waste inventory of the facility. (author)
Active Na absorption (J/sub net//sup NA/) in rabbit proximal colon in vitro is paradoxically stimulated as (Na) in the bathing media is lowered with constant osmolarity. J/sub m..-->..s//sup Na/ increases almost linearly from 0 to 50 mM (Na)/sub 0/ but then plateaus and actually decreases from 50 to 140 mM (Na)/sub 0/, consistent with inhibition of an active transport process. Both lithium and Na are equally effective inhibitors of J/sub net//sup Na/, whereas choline and mannitol do not block the high rate of J/sub net//sup Na/ observed in decreased (Na)/sub 0/. Either gluconate or proprionate replacement of Cl inhibits J/sub net//sup Na/. J/sub net//sup Na/ at lowered (Na)/sub 0/ is electrically silent and is accompanied by increased Cl absorption; it is inhibited by 10/sup -3/ M amiloride and 10/sup -3/ theophylline but not by 10/sup -4/ M bumetanide. Epinephrine is equally effective at stimulating Na absorption at 50 and 140 mM (Na). Na gradient experiments are consistent with a predominantly serosal effect of the decreased (Na)/sub 0/. These results suggest that 1) Na absorption in rabbit proximal colon in vitro is stimulated by decreased (Na); 2) the effect is cation specific, both Na and Li blocking the stimulatory effect; 3) the transport is mediated by Na-H exchange and is Cl dependent but 4) is under different regulatory mechanisms than the epinephrine-sensitive Na-Cl cotransport previously described in proximal colon. Under the appropriate conditions, proximal colon absorbs Na extremely efficiently. Na-H exchange in this epithelium is cation inhibitable, either directly or by a secondary regulatory process.
1987-01-01
Active Na absorption (J/sub net//sup NA/) in rabbit proximal colon in vitro is paradoxically stimulated as (Na) in the bathing media is lowered with constant osmolarity. J/sub m..-->..s//sup Na/ increases almost linearly from 0 to 50 mM (Na)/sub 0/ but then plateaus and actually decreases from 50 to 140 mM (Na)/sub 0/, consistent with inhibition of an active transport process. Both lithium and Na are equally effective inhibitors of J/sub net//sup Na/, whereas choline and mannitol do not block the high rate of J/sub net//sup Na/ observed in decreased (Na)/sub 0/. Either gluconate or proprionate replacement of Cl inhibits J/sub net//sup Na/. J/sub net//sup Na/ at lowered (Na)/sub 0/ is electrically silent and is accompanied by increased Cl absorption; it is inhibited by 10/sup -3/ M amiloride and 10/sup -3/ theophylline but not by 10/sup -4/ M bumetanide. Epinephrine is equally effective at stimulating Na absorption at 50 and 140 mM (Na). Na gradient experiments are consistent with a predominantly serosal effect of the decreased (Na)/sub 0/. These results suggest that 1) Na absorption in rabbit proximal colon in vitro is stimulated by decreased (Na); 2) the effect is cation specific, both Na and Li blocking the stimulatory effect; 3) the transport is mediated by Na-H exchange and is Cl dependent but 4) is under different regulatory mechanisms than the epinephrine-sensitive Na-Cl cotransport previously described in proximal colon. Under the appropriate conditions, proximal colon absorbs Na extremely efficiently. Na-H exchange in this epithelium is cation inhibitable, either directly or by a secondary regulatory process.
50 CFR 17.11 - Endangered and threatened wildlife.
... E 15 NA NA Turtle, three-keeled Asian Melanochelys tricarinata...immediately above the Kennebec River Gorge in the town of Indian Stream Township... NA NA Snail, flat-spired three-toothed Triodopsis...
2010-01-01
The Na+/K+-ATPase exports 3Na+ and imports 2K+ at the expense of the hydrolysis of 1 ATP. In the absence of K+, it carries on electroneutral, Na+-dependent transient charge movement (also known as electroneutral Na+/Na+ exchange mode) and produces a transient current containing faster and slower components in response to a sudden voltage step. Components with different speeds represent sequential release of Na+ ions from three binding sites. The effect of holding potential on slow charge movement was studied in the presence of different concentrations of ADPi, Na i + and Na o + with the intention of improving our understanding of Na i + binding. However, the manipulation of [ADP]i and [Na+]i did not cause as pronounced changes as predicted in the magnitude of charge movement (Q tot), wh...
Ternary systems NaF-NaBr-Na2MoO4, KF-KCl-KB Trekhkomponentnye sistemy NaF-NaBr-Na2MoO4, KF-KCl-KBr
2009-01-01
Phase equilibriums in ternary systems NaF-NaBr-Na2MoO4 and KF-KCl-KBr have been studied by physicochemical methods of differential thermal and X-ray diffraction analyses. Triple eutectics and peritectics melting at 506 and 570 Deg C with specific enthalpy of melting equal to 241 and 328 kJ/kg, properly have been revealed in the NaF-NaBr-Na2MoO4 system. Two non-variant equilibriums exist in the NaF-NaBr-Na2MoO4 system, temperatures of crystallization and concentrations of initial components corresponding these equilibriums have been revealed
1991-01-01
Recent studies in hepatocytes indicate that Na(+)-coupled HCO3- transport contributes importantly to regulation of intracellular pH and membrane HCO3- transport. However, the direction of net coupled Na+ and HCO3- movement and the effect of HCO3- on Na+ turnover and Na+/K+ pump activity are not known. In these studies, the effect of HCO3- on Na+ influx and turnover were measured in primary rat hepatocyte cultures with 22Na+, and [Na+]i was measured in single hepatocytes using the Na(+)-sensitive fluorochrome SBFI. Na+/K+ pump activity was measured in intact perfused rat liver and hepatocyte monolayers as Na(+)-dependent or ouabain-suppressible 86Rb uptake, and was measured in single hepatocytes as the effect of transient pump inhibition by removal of extracellular K+ on membrane potential difference (PD) and [Na+]i. In hepatocyte monolayers, HCO3- increased 22Na+ ...
2008-01-01
Ion exchange isotherms for the sodium form of birnessite, a layered manganese oxide common in soils, were determined using isotope dilution analysis, by employing 22Na to pre-label the solid. The results were represented by plotting the equivalent ionic fraction of an entering cation in the ion exchanger versus the equivalent ionic fraction of the entering cation remaining in solution. Studying these ion exchange isotherms for sodium-univalent (i.e. NH4-Na, Li-Na, K-Na, and Cs-Na) and sodium-divalent pairs (Mg-Na, Ca-Na, Sr-Na and Ba-Na) on 22Na-birnessite made it possible to obtain a clear picture of the exchangeable sites available in birnessite. The isotherms also gave an estimation of the effect of cations likely to be present in aqueous environments on the uptake of the fission product radioisotopes of caesium and strontium ...
Effect of cadmium on transmembrane Na+ and K+ transport systems in human erythrocytes.
The effects of cadmium (Cd2+) on Na+,K(+)-ATPase in disrupted human erythrocyte membranes and on various transmembrane Na+ and K+ transport systems in intact erythrocyte suspensions were studied. Cadmium2+ inhibited the erythrocyte Na+,K(+)-ATPase enzyme with a 50% inhibition at a Cd2+ concentration of 6.25 microM. The Cd2+ inhibition in the human erythrocyte was non-competitive with respect to Na+,K+, and ATP. Cadmium2+ exerted no acute effect, however, on the Na+,K(+)-ATPase pump activity as measured by the ouabain sensitive 86Rb uptake or Na+ efflux in intact red blood cells. Cadmium2+ also inhibited the Ca2+ dependent K+ channels in human red blood cells, whereas it had no effect on Na+,K+ cotransport, Na+,Li+ countertransport, anion carrier, and the number of active Na+ pump units. The data indicate that in human erythrocytes under acute conditions Cd2+ exerts an inhibitory effect on Na+,K(+)-ATPase enzyme in disrupted erythrocytes and the Ca2+ stimulated K+ efflux in intact red blood cells without affecting the Na+ pump, Na+,K+ cotransport, and Na+,Li+ countertransport activity.
The specific ion effect on emulsions, foam and gels of a seed protein concentrate
2008-01-01
Protein concentrate was prepared from the seeds of jack bean (Canavalia ensiformis) and the influences of selected Hofmeister salts on some functional properties of the protein concentrate were investigated. The results indicate that kosmotropic salts (Na2SO4, NaCl, NaBr) had improved water absorption capacities over the chaotropic salts (NaI, NaClO4, NaSCN) and generally, the reduction in water absorption capacity followed the Hofmeister trend: Na2SO4
In situ synthesis of silica gel nanowire/Na+-montmorillonite nanocomposites by the sol-gel route
2007-01-01
Silica-gel nanowire/Na+-montmorillonite (Na+-MMT) nanocomposites were prepared by the in situ sol-gel process of tetraethyl orthosilicate (TEOS) in the presence of Na+-MMT and ammonia as catalyst. Microstructure characterization of the nanocomposites was done by SEM, TEM, EDX, XRD and FTIR. It was found that a lot of silica-gel nanowires grew along the edges of Na+-MMT. The combination between the nanowires and Na+-MMT was accomplished via polycondensation of the hydrolyzed TEOS and the edge -OH groups of Na+-MMT
Amination of butanol on Na forms of zeolites
1986-06-10
This paper studies the amination of 1-butanol by ammonia on the forms of zeolites with a different SiO/sub 2//A1/sub 2/O/sub 3/ ratio and a different backbone structure. The catalytic properties of the zeolites were compared with A1/sub 2/O/sub 3/ which is a well-known catalyst of amination. It is shown that the activity and selectivity of the zeolites increase in the order na-mordenite NaA, NaHSZ, NaY, NaX. Nonlocalized sodium cations are the carriers of the catalytic activity in the reaction of amination on Na forms of zeolites.
The low temperature adsorption of CO and the room temperature adsorption of acetonitrile, propionitrile, isobutyronitrile, pivalonitrile, benzonitrile, and o-toluonitrile on Na-mordenite (NaMOR) have been investigated by Fourier transform infrared (FT-IR) spectroscopy. The results have been compared with analogous experiments performed on H-mordenite, Na-X zeolite, and Na-silica-alumina. The Na distribution in NaMOR has also been investigated by X-ray diffraction and far-IR spectroscopy. The conclusions are that Na+ ion distribution is essentially random and that, together with the well-known interaction of the probes with Na+ ions in the side pockets and the main channels, a stronger additional interaction occurs in all cases. This new interaction is likely multiple, involving either more Na+ ions or Na and oxygen species. This interaction is more pronounced with the hindered nitriles, whose access at the main channels is likely forbidden. This suggests that this interaction, which is also observed on Na-X zeolites but not with Na-silica-alumina, occurs at the external mouths of the mordenite channels.
Targeting of renal proximal tubule Na,K-ATPase by salt-inducible kinase
2010-01-01
The renal proximal tubule (RPT) is a central locale for Na+ reabsorption, and blood pressure regulation. Na+ reabsorption in the RPT depends upon the Na,K-ATPase, which is controlled by a complex regulatory network, including Salt-Inducible Protein Kinase (SIK). SIKs are recently discovered members of the AMP-activated Protein Kinase (AMPK) family, which regulate salt homeostasis and metabolism in a number of tissues. In the RPT, SIK interacts with the Na,K-ATPase in the basolateral membrane (BM), regulating both the activity and level of Na,K-ATPase in the BM. Thus, Na,K-ATPase activity can be rapidly adjusted in response to changes in Na+ balance. Long-term changes in Na+ intake affect the state of SIK phosphorylation, and as a consequence the phosphorylation of TORCs, Transducers of Reg...
2008-01-01
The phase of equilibrium in the system Na2SO4-Na2CO3-NaF-H2O at 0digC is investigated by means of Translation Method. It is determined that the system is a member of simple eutectic system. There is one invariant point, four mono variant carves and six di variant equilibrium is modeled for the first time
New mechanism for the control of sodium transport in wheat
2002-01-01
Full text: Durum and other tetraploid wheats are typically very salt-sensitive compared to hexaploid bread wheats. This is primarily due to high rates of Na+ accumulation in the leaves in tetraploid wheat. Recently, we have discovered a durum landrace with low Na+ accumulation and enhanced K+/Na+ discrimination, much lower than current durum cultivars and similar to bread wheat. We have identified 3 different mechanisms for the control of Na+ transport to the leaves in this landrace, 1) control of Na+ uptake at the epidermis of the root, 2) control of Na+ loading into the xylem and 3) partitioning of Na+ into the leaf sheath. The low Na+ durum landrace had 3-4 fold lower Na+ uptake rates than durum cultivars. Using X ray microanalysis on snap-frozen root ...
1983-04-01
The room temperature modification of stoichiometric NASICON(Sc) is monoclinic Cc. At 64/sup 0/C there is a first order transition to a normal-conducting rhombohedral form R anti 3c. Na(1) sites are fully occupied whereas Na(2) sites are partially occupied. At 167/sup 0/C there is a transition to a superionic phase, but the structure remains rhombohedral R anti 3c. Vacancies are now shared equally by Na(1) and Na(2) sites. Fast Na-ion motion in stoichiometric Na/sub 3/Sc/sub 2/(PO/sub 4/)/sub 3/ arises from vacancy motion in a dogleg path between Na(1) and Na(2) sites.
2010-01-01
The through-diffusion of HTO, 22Na+ and 36Cl- in kaolinite, homo-ionic Na-illite and homo-ionic Na-montmorillonite was measured at a high degree of compaction as a function of the salt concentration in the `external solution', i.e. in the solution in contact with the clay sample. The clays were chosen for this study because of their differences in the number and nature of ion exchange sites leading to different proportions of interlayer-, inter-particle and free pore water. It was found that the diffusive mass transfer of Na+ in Na-montmorillonite and Na-illite increased with decreasing external salt concentration, while the opposite trend was observed for the diffusion of Cl-. These trends are more pronounced in the case of Na-montmorillonite than in Na-illite, while almost no salt effect...
Chemical interactions in multimetal/zeolite catalysts
This report treats four subject areas: PtCu/NaY and Pd/Cu/NaY catalysts; reducibility of Ni in PdNi/NaY catalysts; CO hydrogenation over PdNi/NaY catalysts; and PdFe/NaY, Ga/H-ZSM5 and PtGa/H-ZSM5 catalysts.
Chemical interactions in multimetal/zeolite catalysts
1992-02-07
This report treats four subject areas: PtCu/NaY and Pd/Cu/NaY catalysts; reducibility of Ni in PdNi/NaY catalysts; CO hydrogenation over PdNi/NaY catalysts; and PdFe/NaY, Ga/H-ZSM5 and PtGa/H-ZSM5 catalysts.
1974-11-01
The surface potentials of adsorbed monolayers of Na-n-octylsulfate and Na-n-dodecylsulfate at the interface air/NaCl solution have been investigated. The results are compared with the measurements of a Na-n-octylsulfate monolayer at the interface nonane/NaCl solution. The curve of the delta V-C dependence and the intermolecular interactions in the concentration range above and below CMC are discussed. (16 refs.)
Transport of Na48 Drift Chambers to Dubna
On 22 July, in the occasion of the departure of the Na48 Drift Chambers from CERN, Mikhail Itkis (acting Director of the JIINR) and Rolf Heuer (CERN Director General) visited the NA62 experimental area.
The discharge properties of Na/Ni3S2 cell at ambient temperature
2008-01-01
The discharge properties of a Na/Ni3S2 cell using 1M NaCF3SO3 in tetra(ethylene glycol)dimethyl ether liquid electrolyte were investigated at room temperature. The products were characterized by X-ray diffraction, scanning electron microscopy and energy dispersive spectroscopy. Electrochemical properties of Na/Ni3S2 cells were also presented by cyclic voltammetry and the galvanostatic current method. Na/Ni3S2 cells have an initial discharge capacity of 420mAhg-1 with a plateau potential at 0.94V versus Na/Na+. After the first discharge, Ni3S2 and Na react at room temperature and then form sodium sulfide (Na2S) and nickel. Sodium ion can be partially deintercalated from Na2S charge reaction. The discharge process can be explained as follows: Ni3S2+4Na3Ni+2Na2S.
The Beam and Detector for the NA48 Neutral Kaon CP Violation Experiment at CERN
The Beam and Detector, used for the NA48 experiment, devoted to the measurement of $Re(\\epsilon^{\\prime}/\\epsilon)$, and for the NA48/1 experiment on rare K_S and neutral hyperon decays, are described.
Structural Analysis of Ion Selectivity in the NaK Channel
2009-01-01
Here, we present a detailed characterization of ion binding in the NaK pore using the high resolution structures of NaK in complex with various cations. These structures reveal four ion binding...Full Text Available
Solubility of sodium and potassium iodates in saturated salt solutions
2009-01-01
The determination of the solubilities of KIO3 and NaIO3 in saturated NaCl solution at 0, 10, 20degreeC were carried out in two ternary systems KIO3-NaCl-H2O and NaIO3-NaCl-H2O. Saturated KIO3 and NaIO3 solutions were prepared and NaCl was added to saturation. Iodate concentrations were measured using standardized sodium thiosulphate. The solubilities of KIO3 and NaIO3 are temperature sensitive over the range 0degreeC to 20degreeC (unlike NaCl). Iodate solubility was much lower in saturated NaCl than that of deionised water. In saturated NaCl at 10degreeC, for example, NaIO3 was 19% and KIO3 was 15% the solubility of that found in deionised water at the same temperature.
Regulation of Na+ transport in brown adipose tissue.
1986-04-15
Full Text Available.In order to test the hypothesis that Na+, K+-ATPase (Na+,K+-dependent ATPase) is involved in the noradrenaline-mediated stimulation of respiration in brown adipose tissue, the effects of noradrenaline on Na+,K+-ATPase in isolated brown-fat-cell membrane vesicles, and on 22Na+ and K+ (86Rb+) fluxes across the membranes of intact isolated cells, were measured. The ouabain-sensitive fraction of the K+-dependent ATPase activity in the isolated membrane-vesicle preparation was small and was not affected by the presence of noradrenaline in the incubation media. The uptake of 86Rb+ into intact hormone-sensitive cells was inhibited by 80% by ouabain, but it was insensitive to the presence of noradrenaline. 22Na+ uptake and efflux measured in the intact cells were 8 times more rapid than the 86Rb+ fluxes and were unaffected by ouabain. This indicated the presence of a separate, more active, transport system for Na+ than the Na+,K+-ATPase. This is likely to be a Na+/Na+ exchange activity under normal aerobic conditions. However, under anaerobic conditions, or conditions simulating anaerobiosis (2 mM-NaCN), the unidirectional uptake of Na+ increased dramatically, while efflux was unaltered.
Regulation of Na+ transport in brown adipose tissue.
In order to test the hypothesis that Na+, K+-ATPase (Na+,K+-dependent ATPase) is involved in the noradrenaline-mediated stimulation of respiration in brown adipose tissue, the effects of noradrenaline on Na+,K+-ATPase in isolated brown-fat-cell membrane vesicles, and on 22Na+ and K+ (86Rb+) fluxes across the membranes of intact isolated cells, were measured. The ouabain-sensitive fraction of the K+-dependent ATPase activity in the isolated membrane-vesicle preparation was small and was not affected by the presence of noradrenaline in the incubation media. The uptake of 86Rb+ into intact hormone-sensitive cells was inhibited by 80% by ouabain, but it was insensitive to the presence of noradrenaline. 22Na+ uptake and efflux measured in the intact cells were 8 times more rapid than the 86Rb+ fluxes and were unaffected by ouabain. This indicated the presence of a separate, more active, transport system for Na+ than the Na+,K+-ATPase. This is likely to be a Na+/Na+ exchange activity under normal aerobic conditions. However, under anaerobic conditions, or conditions simulating anaerobiosis (2 mM-NaCN), the unidirectional uptake of Na+ increased dramatically, while efflux was unaltered.
The probe segments also contained heaters which provided heat to measure the ... The drill and rack was carried to the second probe site and the entire procedure was repeated. ... Platinum resistors provided heat, and the temperature rise at known ... Sampling operations - soil, rocks: NA. Trenching: NA. Raking: NA ...
Comparison of ouabain-sensitive 86Rb uptake of canine renal and femoral arteries
1986-08-01
We have previously reported that various manifestations of the Na+ pump, such as ouabain binding, Na+-K+-ATPase, and /sup 86/Rb uptake, were similar in canine renal and femoral arteries. In this report we compare ouabain-sensitive /sup 86/Rb uptake in renal and femoral arteries under two selected conditions of intracellular Na+:low Na+ and Na+ loaded. When intracellular Na+ was low, the renal artery dissociation constant for Rb+ was 1.13 mM compared with the Na+-loaded condition of 2.49 mM. The femoral artery dissociation constant remained the same at both Na+ levels. The maximal rate of /sup 86/Rb uptake (Vmax) of the renal artery was the same at both Na+ levels, but the femoral artery Vmax was 23.6 and 11.11 nmol X mg-1 X 20 min-1 in Na+-loaded and low-Na+ vessels, respectively. The reason for the difference in Na+ pump regulation in these two vessels is not clear, but these results suggest that there are heterogeneous mechanisms for controlling ionic movements in vascular smooth muscle.
A law of the iterated logarithm of partial sums for NA random variables
2010-01-01
Consider a sequence of NA identically distributed random variables with the underlying distribution in the domain of attraction of the normal distribution. This paper proves that law of the iterated logarithm holds for sequences of NA random variables.
TECHNICAL DESCRIPTION OF A SODIUM-COMPONENT TEST INSTALLATION
The instellation is designed primarily for operational testing of Na- heated steam generators and intermediate heat exchangers suitable as prototype components for large, Na-cooled power plants. Other types of Na components can also be tested in the facility. The instellation consists of a 35-Mwt gas-fired Na heat source, a main primary-Na system, a main secondary-Na system, a water- steam system, and a set-up for heat rejection to air. (J.R.D.)
2000-01-01
The subject of this article is the personnel behavior and initiating events modeling, based on the operational experience in the NPP 'Kozloduy' initiating events reports. The development of models on qualitative information is much more difficult comparing the quantitative modeling. The modelling process is based on the artificial intelligence theory and methods including knowledge base and inference machine in the frame of logical models and semantic networks. (author)
2010-01-01
Naphthenic acids (NA) are a complex mixture of carboxylic acids that are natural constituents of oil sand found in north-eastern Alberta, Canada. NA are released and concentrated in the alkaline water used in the extraction of bitumen from oil sand sediment. NA have been identified as the principal toxic components of oil sands process-affected water (OSPW), and microbial degradation of lower molecular weight (MW) NA decreases the toxicity of NA mixtures in OSPW. Analysis by proton nuclear magnetic resonance spectroscopy indicated that larger, more cyclic NA contain greater carboxylic acid content, thereby decreasing their hydrophobicity and acute toxicity in comparison to lower MW NA. The relationship between the acute toxicity of NA and hydrophobicity suggests that narcosis is the probab...
Pressure dependence of the ionic conductivity of Na- and NaRb borate glasses
2006-01-01
The ionic conductivity of Na- and NaRb borate glasses is investigated as a function of hydrostatic pressure. Activation volumes of the dc conductivity are obtained from pressure-dependent ac conductivity measurements at a constant temperature of 180C. The activation volume of Na borate glasses decreases with increasing alkali content. It depends linearly on a separation parameter which is defined as the ratio of the average ionic distance and the average network atom distance. The activation volume of NaRb borate glasses increases from both end-members towards the mixed-alkali regime and passes through a maximum near the relative content Na/(Na+Rb)=0.4. In addition to mobility anomalies, observed earlier in these borate glasses, the maximum in the activation volume is a further i...
Nucleic acid extraction from biomining microorganisms
2009-01-01
Various methods of nucleic acid (NA) extraction were investigated with the aim of developing a quantitative method of NA extraction from five representative strains of biomining microorganisms. The process of removing cells from mineral surfaces, lysing microorganisms, precipitating NA and purifying RNA were analysed. The success of each method was examined spectrophotometrically, by agarose gel electrophoresis and PCR or quantitative real time PCR (qPCR). The most important step was shown to be cellular lysis, which principally impacted on thequantity of NA extracted from each strain. The quantity and quality of extracted NA was highlydependent on the method of NA precipitation. This study resulted in the development of a NA extraction method that reliably and reproducibly extracted NA from five strains of biomining microorganisms. Publisher: School of Biomedical Sciences
Nuclear magnetic resonance studies of metal ions in biological systems
2005-01-01
The subject of this Ph.D. thesis is to demonstrate the utilities of nuclear magnetic resonance (NMR), in both solution and solid-state, to study metal ions in biologically relevant molecules. We have used one- and two-dimensional solid-state 23Na NMR spectroscopy to determine accurate 23Na NMR parameters for Na+ sites in 10 nucleotides. Quantum mechanical calculation of 23Na NMR parameters was performed to unambiguously assign the observed 23Na parameters to individual Na+ sites. We have identified for the first time 23Na, 39K and 15N NMR spectral signatures (or spectral features) for Na+, K+ and NH4+ cations bound to a four stranded nucleic acid structure known as G-quadruplex. We have introduced a novel solid-state ...
NaCl multi-layer islands grown on Au(111)-(22xsq root3) probed by scanning tunneling microscopy
2008-01-01
The growth of multi-layer NaCl islands on Au(111)-(22xsq root3) surfaces was investigated using scanning tunneling microscopy (STM). We observed that the aspect of the NaCl islands drastically differs depending on the tunneling conditions. It is therefore possible to observe the layers forming an NaCl island or to image the gold reconstruction below the first NaCl layer. Atomically resolved STM images obtained on the first NaCl layer demonstrate that NaCl grows as an epitaxial crystalline film on Au(111)-(22xsq root3). STM images also suggest that some NaCl layers can be non-crystalline
Measurement of the electric quadrupole moments of {sup 26-29}Na
2000-05-01
The nuclear electric quadrupole moments of the isotopes {sup 26}Na, {sup 27}Na, {sup 28}Na and {sup 29}Na were measured by {beta}-NMR spectroscopy in single crystals of LiNbO{sub 3} and NaNO{sub 3}. High degrees of nuclear polarization were produced by optical pumping of the sodium atoms in a fast beam with a collinear laser beam. The polarized nuclei were implanted into the crystals and NMR signals were observed in the {beta}-decay asymmetries. Preparatory measurements also yielded improved values for the magnetic moments of {sup 27-31}Na and confirmed the spin I=3/2 for {sup 31}Na. The results are discussed in comparison with large-basis shell model calculations. (orig.)
Measurement of the electric quadrupole moments of $^{26-29}Na$
The nuclear electric quadrupole moments of the isotopes $^{26}$Na, $^{27}$Na, $^{28}$Na and $^{29}$Na were measured by $\\beta$-NMR spectroscopy in single crystals of LiNbO$_3$ and NaNO$_3$. Highdegrees of nuclear polarization were produced by optical pumping of the sodium atoms in a fast beam with a collinear laser beam.The polarized nuclei were implanted into the crystalsand NMR signals were observed in the $\\beta$-decay asymmetries. Preparatory measurements also yielded improved values for the magnetic moments of $^{27-31}$Na and confirmed the spin $I=3/2$for $^{31}$Na. The results are discussed in comparison withlarge-basis shell-model calculations.
Hydration valve controlled non-selective conduction of Na^+ and K^+ in the NaK channel
2010-01-01
The Na^+ and K^+ channels are essential to neural signaling, but our current knowledge at the atomic level is mainly limited to the conducting mechanism of K^+. Unlike a K^+ channel having four equivalent K^+-binding sites in its selectivity filter, a NaK channel has a vestibule in the middle part of its selectivity filter, and can conduct both Na^+ and K^+ ions. However, the underlying mechanism for non-selective ion conduction in NaK remains elusive. Here we find four small grottos connecting with the vestibule of the NaK selectivity filter, which form a vestibule-grotto complex perpendicular to the filter pore with a few water molecules within it. It is shown that two or more of the water molecules coming to the vestibule to coordinate the cation are necessary for conducting both Na^+ a...
Functional compartmentalization of oxidative and glycolytic metabolism in frog skin
1985-01-01
One of the basic functions of the epithelial cells of the skin of amphibians is unidirectional transport of Na+ from the environment into the blood. This transport is carried out in two stages. First, Na+ is absorbed from the environment by the epithelial cells through their apical membranes. Next, Na+ is actively drawn into the blood stream with the help of Na-K pumps which are located on the basolateral membranes. Huf, as early as 1957, proposed that ionic homeostasis of Na-transporting epithelial cells may be maintained at the expense of glycolysis, whereas the unidirectional transport of Na+ requires exclusively energy from oxidative metabolism. At that time, however, little was known about the nature of the Na-K pump and there were no isotopic data on permeability of epithelial cells to Na+ and K+. ...
Biosynthesis of trigonelline from nicotinate mononucleotide in mungbean seedlings
2008-01-01
To determine the biosynthetic pathway to trigonelline, the metabolism of [carboxyl-14C]nicotinate mononucleotide (NaMN) and [carboxyl-14C]nicotinate riboside (NaR) in protein extracts and tissues of embryonic axes from germinating mungbeans (Phaseolus aureus) was investigated. In crude cell-free protein extracts, in the presence of S-adenosyl-l-methionine, radioactivity from [14C]NaMN was incorporated into NaR, nicotinate and trigonelline. Activities of NaMN nucleotidase, NaR nucleosidase and trigonelline synthase were also observed in the extracts. Exogenously supplied [14C]NaR, taken up by embryonic axes segments, was readily converted to nicotinate and trigonelline. It is concluded that the NaMNNaRnicotinatetrigonelline pathway is operative in the embryonic axes of mungbean seedlings. T...
2010-01-01
The title compound Na2[BH4][NH2]=Na2BNH6 exists in two different modifications: the low-temperature (LT) b- and the high-temperature (HT) a-phase. The HT a-Na2BNH6 is accessible by single heating of the binaries NaNH2 and NaBH4 (molar ratio=1:1) to the melting point of 492K for 1h in evacuated Pyrex ampoules. On longer annealing (T=342K, 10 days), the HT a-phase converts completely to the LT b-phase. The b-
Rodlike micelles of sodium dodecyl sulfate in concentrated sodium halide solutions
1981-01-08
Light scattering from aqueous solutions of sodium dodecyl sulfate has been measured in the presence of 0.80 mole sodium halides at 35 C. Sodium dodecyl sulfate forms micelles having a molecular weight of aprox. 50,000 or less, at the critical micelle concentration, 0.013 g dl/sup -1/, in solutions of all sodium halides except for NaSCN, in which the micelle size is even smaller. The average micelle size increase with increasing concentration of sodium dodecyl sulfate further, and it reaches a maximum around 1 g dl/sup -1/. The molecular weight of the large micelle formed at the high concentrations is in increasing order: NaSCN, NaF, NaCl, NaBr and NaI; it is 185,000 in NaSCN and 357,000 in NaI solutions. The angular dependence of light scattering indicated that the large micelles are rodlike and have a common structure in NaCl, NaBr, and NaI solutions. 20 references.
Deliquescence of NaCl-NaNO3 and KNO3-NaNO3 Salt Mixtures at 90C
We conducted reversed deliquescence experiments in saturated NaCl-NaNO3-H2O and KNO{sub 3}-NaNO{sub 3}-H{sub 2}O systems at 90 C to determine relative humidity and solution composition. NaCl, NaNO{sub 3}, and KNO{sub 3} represent members of dust salt assemblages that are likely to deliquesce and form concentrated brines on high-level radioactive waste package surfaces in a repository environment at Yucca Mountain, NV, USA. Model predictions agree with experimental results for the NaCl-NaNO{sub 3}-H{sub 2}O system, but underestimate relative humidity by as much as 8% and solution composition by as much as 50% in the KNO{sub 3}-NaNO{sub 3}-H{sub 2}O system.
Deliquescence of NaCl-NaNO3 and KNO3-NaNO3 Salt Mixtures at 90C
2003-12-29
We conducted reversed deliquescence experiments in saturated NaCl-NaNO3-H2O and KNO{sub 3}-NaNO{sub 3}-H{sub 2}O systems at 90 C to determine relative humidity and solution composition. NaCl, NaNO{sub 3}, and KNO{sub 3} represent members of dust salt assemblages that are likely to deliquesce and form concentrated brines on high-level radioactive waste package surfaces in a repository environment at Yucca Mountain, NV, USA. Model predictions agree with experimental results for the NaCl-NaNO{sub 3}-H{sub 2}O system, but underestimate relative humidity by as much as 8% and solution composition by as much as 50% in the KNO{sub 3}-NaNO{sub 3}-H{sub 2}O system.
Sodium transport in capillaries isolated from rat brain
1983-10-01
Brain capillary endothelial cells form a blood-brain barrier (BBB) that appears to play a role in fluid and ion homeostasis in brain. One important transport system that may be involved in this regulatory function is the Na+, K+-ATPase that was previously demonstrated to be present in isolated brain capillaries. The goal of the present study was to identify additional Na+ transport systems in brain capillaries that might contribute to BBB function. Microvessels were isolated from rat brains and 22Na+ uptake by and efflux from the cells were studied. Total 22Na+ uptake was increased and the rate of 22Na+ efflux was decreased by ouabain, confirming the presence of Na+, K+-ATPase in capillary cells. After inhibition of Na+, K+-ATPase activity, another saturable Na+ transport mechanism became apparent. Capillary uptake of 22Na+ was stimulated by an elevated concentration of Na+ or H+ inside the cells and inhibited by extracellular Na+, H+, Li+, and NH4+. Amiloride inhibited 22Na+ uptake with a Ki between 10(-5) and 10(-6) M but there was no effect of 1 mM furosemide on 22Na+ uptake by the isolated microvessels. These results indicate the presence in brain capillaries of a transport system capable of mediating Na+/Na+ and Na+/H+ exchange. As a similar transport system does not appear to be present on the luminal membrane of the brain capillary endothelial cell, it is proposed that Na+/H+ exchange occurs primarily across the antiluminal membrane.
STUDIES ON ELIMINATION OF RADIOACTIVE CESIUM. (2nd Report)
Pharmacological means to accelerate the elimination of Cs-137 introduced into the living organism are studied. Male dd mice and male Wistar rats are individually housed in metal metabolism cages, and provided with commercial solid diet and water. Radioactivity is determined in urine, and feces for 24 hours and 4 days after subcutaneous injection of a tracer dose of Cs/sup 137/Cl, and in various organs after sacrifices at the ends of these periods. Effects of various chemicals on these results are compared. Twenty five chemicals were investigated. They include inorganic Na salts such as Na bicarbonate, Na carbonate, Na suliate, Na thiosulfate, primary and secondary Na phosphates, and organic Na salts such as Na lactate, lactated Ringer, Na acetate, Na glucuronate, Na salt of thioctic acid, ATP Na, and Na pentobarbiturate. Na bicarbonate, Na phosphates, Na sulfate, and Na thiosulfate are found as eifective, especially Na bicarbonate, K bicarbonate shows scarcely any effect, nor do other K salts. It is therefore assumed that Cs will exchange with Na ion in the tubular cells. LiCl is found to accelerate the excretion of Cs-137 from mice and rats. This result is of interest with respect to the periodic law, since it is known that for the elimination of Sr-90, Ca salts are ineffective or slightly effective, whereas Mg salts are effective. Of the diuretics, chlorothiazide, which is considered to increase the excretion of K, does nor increase the elimination of Cs-137 in any dose. This result is different from that of Diamox, a diuretic of the same nature. Cardiac glycosides and xanthine derivatives are effective. Out of digitalis preparations, Digitamin (Shionogi), Digilanogen C (Fujisawa), Digosin (Chugai) are effective. Digitoxin and strospeside are ineffective, and after their application, retention of Cs-137 is observed in the heart muscle. G- strophanthin is ineffective in a smaller dose, but increases the elimination of Cs-137 in a larger dose. Caffeine and sodium benzoate are also effective, but theophylline and theobromine are not so effective. Out of osmotic diuretics, Na ferrocyanate alone increases fecal excretion of Cs-137, and decreases the retention in the body. NaI and KI have scarcely any effect. Phosphomolybdic acid inhibits the elimination of Cs-137 and increases its retention. The above mentioned effective chemicals are also investigated for effects on the elimination of Sr-90. (JAIF)
2004-01-01
Both radiotherapy and combination chemotherapy are effective in Hodgkin disease. Treatment stages are changing fundamentally over the last decades and are now influenced by the ultimate goal of curing all patients without inducing long-term toxicity such as secondary malignancies, infertility or cardiac and pulmonary complications. Because of that the treatment must be individualized
1999-12-27
The final state of Pb + Pb reactions at CERN SPS has been reconstructed with the Buda-Lund hydro model, by performing a simultaneous fit to NA49, NA44 and WA98 data on particle correlations and spectra.
1999-01-01
The final state of Pb + Pb reactions at CERN SPS has been reconstructed with the Buda-Lund hydro model, by performing a simultaneous fit to NA49, NA44 and WA98 data on particle correlations and spectra
Optical absorption spectra of small Na alkali-metal clusters
2009-10-20
The photoabsorption cross section of small sodium clusters (Na_4, Na^+_9, and Na+_21) is determined by means of a first-principles based linear response calculation for electron-hole coherences in the presence of an external electromagnetic field. Using a recently implemented approach, the resonance positions and linewidths of the optical absorption including electron-hole correlations are obtained from a consistent treatment of scattering and dephasing contributions in the linear response calculation.
The NaF documentation files are presented in Adobe Acrobat or Word files. PDF Generic Documentation for NaF PDF file Word Generic Documentation for NaF Word file Contact Paula M. Jacobs, Ph.D., 301-435-9181, jacobsp@mail.nih.gov, for information.
Na-Si binary phase diagram and solution growth of silicon crystals
2009-01-01
In the present study, a Na-Si binary phase diagram was first presented from the results of differential thermal analysis and X-ray diffraction. Based on the phase diagram, we performed low-temperature formation of single crystals, film and porous bulk of Si by vaporizing Na from a Na-Si melt at 800 or 900 deg. C
Ion exchange of ammonium in natural and synthesized zeolites
2008-01-01
In this study, zeolite Na-P and Na-Y was prepared by hydrothermal treatment of the Chinese natural clinoptilolite with NaOH. The ion exchange of NH4+ into the three zeolites in the temperature range of 288-333 K was also investigated, and the thermodynamic parameters were calculated. The selectivity sequence for NH4+ entering the sodium form of the three materials was Na-clinoptilolite
Fragmentation of the photoabsorption strength in neutral and charged metal microclusters
2010-02-21
The line shape of the plasma resonance in both neutral and charged small sodium clusters is calculated. The overall properties of the multipeak structure observed in the photoabsorption cross section of spherical Na_8 and Na_20 neutral clusters can be understood in terms of Landau damping. Quantal configurations are shown to play an important role. In the case of charged Na_9+ and Na_21^+ clusters a single peak is predicted that carries most of the oscillator strength.
A simple model for the refractive index of sodium iodide aqueous solutions
2000-03-01
A model for predicting the refractive index of sodium iodide (NaI) aqueous solution n{sub NaI} as a function of temperature T, NaI concentration c and wavelength {lambda} was determined for moderate parameter variations. The equation accurately predicted the salt concentration required to match n{sub NaI} to the refractive index of Pyrex n{sub P}. (orig.)
2006-01-01
This article reviews mainly the authors' efforts in studying and understanding the IR and Raman vibrational spectroscopic characteristics of (na)phthalocyanine in sandwich-type (na)phthalocyaninato and porphyrinato rare earth complexes. On the basis of systematic studies into the vibrational characteristics of (na)phthalocyanine in a wide range of homoleptic and heteroleptic bis- and tris-[(na)phthalocyaninato] and mixed (porphyrinato)[(na)phthalocyaninato] complexes of the whole series of rare earth metals, the effects of substituents, molecular symmetry, rare earth ionic size, rare earth valence state, and excitation wavelength on the vibrational characteristics of (na)phthalocyanine in sandwich rare earth complexes have been comparatively studied. The assignments of the IR and Raman ban...
2010-01-01
The purpose of this work was to develop technology for recycling NaCl containing in human liquid waste as intrasystem matter in a bioregenerative life support system (BLSS). The circulation of Na+ and Cl- excreted in urine is achieved by inclusion of halophytes, i.e. plants that naturally inhabit salt-rich soils and accumulate NaCl in their organs. A model of Na+ and Cl- recycling in a BLSS was designed, based on the NaCl turnover in the human-urine-nutrient solution-halophytic plant-human cycle. The study consisted of (i) selecting a halophyte suitable for inclusion in a BLSS, and (ii) determining growth conditions supporting maximal Na+ and Cl- accumulation in the shoots of the halophyte growing in a nutrient solution simulating mineralized urine. For the selected halophytic plant, Salic...
The reaction dynamics of sodium with ozone
1992-08-15
The reaction of sodium atoms (Na) with ozone (O{sub 3}) has been studied using crossed molecular beams at a collision energy of 18 kcal/mole. The only product observed was NaO. The reaction occurs via an electron-transfer mechanism that yields NaO which is forward scattered with respect to the sodium beam. The translational energy distribution peaks near the forward stripping limit but extends out to the maximum allowed by energy conservation. The fragmentation ratio of NaO upon electron bombardment ionization {ital I}(NaO{sup +})/({ital I}(NaO{sup +})+{ital I}(Na{sup +})) as a function of product translational energy has been measured for an electron energy of 200 V.
1982-01-01
It was previously shown that human lymphocytes maintain a normal accumulation of K+ and exclusion of Na+ between 37 degrees and 10 degrees C., and a significant net accumulation of K+ and exclusion of Na+ at even lower temperatures. The studies reported here show that the level of ATP is near-normal for at least 24 hours between 37 degrees and 10 degrees C., but that ATP synthesis and utilization are progressively and markedly decreased with decreasing temperatures below 37 degrees C. The activities of the membrane Na+- and K+-activated ATPases have typical marked temperature-dependences. Therefore, the normal accumulation of K+ and exclusion of Na+ between 37 degrees and 10 degrees C., and the normal rate of Na+ efflux at these temperatures, do not correlate with properties of the Na+,K+-ATPase or with rates of synthesis and utilization of ATP.
1979-09-01
Phytohemagglutinin (PHA) or concanavalin A treatment of lymphocytes causes an increase in membrane permeability so that the leak rates of Na and K increase 1.5- to 2-fold. Active Na and K transport increase proportionately in response to the increased membrane permeability. We have examined the role of lymphocyte Na concentration in sustaining the increased Na and K transport observed after PHA treatment. Cell Na concentration increases from 14.8 to 20.5 mmol/liter cell water in PHA-treated lymphocytes. Four lines of evidence suggest that the 5 to 6 mmol/liter cell water increase in lymphocyte Na accounts for the increase in active Na and K transport in mitogen-treated lymphocytes.
Metallic Na formation in NaCl crystals with irradiation of electron or vacuum ultraviolet photon
1997-03-01
Metallic Na was formed in NaCl single crystals with irradiation of a variety of radiation sources and analyzed the physical states with several methods. In the case of irradiation of 21 MeV electron pulses to the crystal blocks, the optical absorption and lifetime measurement of positron annihilation indicated appearance of Na clusters inside. Radiation effects of electron beam of 30 keV to the crystals in vacuum showed the appearance of not only metallic Na but atomic one during irradiation with Auger electron spectroscopy. Intense photon fluxes in vacuum ultraviolet region of synchrotron radiation were used as another source and an analyzing method of ultraviolet photoelectron spectroscopy. The results showed the metallic Na layered so thick that bulk plasmon can exist. (author)
Mechanisms of sodium uptake by roots of higher plants
2010-01-01
The negative impact of soil salinity on agricultural yields is significant. For agricultural plants, sensitivity to salinity is commonly (but not exclusively) due to the abundance of Na+ in the soil as excess Na+ is toxic to plants. We consider reducing Na+ uptake to be the key, as well as the most efficient approach, to control Na+ accumulation in crop plants and hence to improve their salt resistance. Understanding the mechanism of Na+ uptake by the roots of higher plants is crucial for manipulating salt resistance. Hence, the aim of this review is to highlight and discuss recent advances in our understanding of the mechanisms of Na+ uptake by plant roots at both physiological and molecular levels. We conclude that continued efforts to investigate the mechanisms of root Na+ uptake in hig...
Long range intermolecular interactions between the alkali diatomics Na2, K2, and NaK
Long range interactions between the ground state alkali diatomics Na2-Na2, K2-K2, Na2-K2, and NaK-NaK are examined. Interaction energies are first determined from ab initio calculations at the coupled-cluster with singles, doubles, and perturbative triples [CCSD(T)] level of theory, including counterpoise corrections. Long range energies calculated from diatomic molecular properties (polarizabilities and dipole and quadrupole moments) are then compared with the ab initio energies. A simple asymptotic model potential ELR=Eelec+Edisp+Eind is shown to accurately represent the intermolecular interactions for these systems at long range.
Li and Na in diamond: A comparison of DFT models
2007-12-15
Interstitial Li and Na have been suggested as alternatives for achieving shallow n-type doping of diamond. Experimental results have however been contradictory. We report ab initio density functional theory modeling of Li and Na in diamond and compare results using periodic pseudopotential plane wave, and all-electron APW+lo methods together with finite clusters using Gaussian basis sets. We show that although interstitial Li and Na are likely to behave as shallow donors, interstitial Li readily diffuses and it is energetically favorable for interstitial Li and Na to be trapped at existing vacancies in diamond. The resulting substitutional centers are not only passivated but also compensate other interstitial Li and Na donors. Na is shown to be incorporated in diamond as a substitutional acceptor, consistent with experimental observations.
Li and Na in diamond: A comparison of DFT models
2007-01-01
Interstitial Li and Na have been suggested as alternatives for achieving shallow n-type doping of diamond. Experimental results have however been contradictory. We report ab initio density functional theory modeling of Li and Na in diamond and compare results using periodic pseudopotential plane wave, and all-electron APW+lo methods together with finite clusters using Gaussian basis sets. We show that although interstitial Li and Na are likely to behave as shallow donors, interstitial Li readily diffuses and it is energetically favorable for interstitial Li and Na to be trapped at existing vacancies in diamond. The resulting substitutional centers are not only passivated but also compensate other interstitial Li and Na donors. Na is shown to be incorporated in diamond as a substitutional acceptor, consistent with experimental observations
2007-03-21
Silica-gel nanowire/Na{sup +}-montmorillonite (Na{sup +}-MMT) nanocomposites were prepared by the in situ sol-gel process of tetraethyl orthosilicate (TEOS) in the presence of Na{sup +}-MMT and ammonia as catalyst. Microstructure characterization of the nanocomposites was done by SEM, TEM, EDX, XRD and FTIR. It was found that a lot of silica-gel nanowires grew along the edges of Na{sup +}-MMT. The combination between the nanowires and Na{sup +}-MMT was accomplished via polycondensation of the hydrolyzed TEOS and the edge -OH groups of Na{sup +}-MMT.
Formation of the complex oxide NaNdTiO4
2008-01-01
The processes of phase formation in the Na2CO3-TiO2 and Na2CO3-TiO2-Nd2O3 systems are investigated in the temperature range 600900C. The high-temperature solid-phase reactions underlying the process of formation of complex oxide NaNdTiO4 are studied. It is established that the synthesis of the NaNdTiO4 compound occurs through the reaction of the intermediate product Na8Ti5O14 with neodymium oxide in the temperature range 720780C. The optimum method is proposed for synthesizing NaNdTiO4, which makes it possible to reduce the temperature of the synthesis, to avoid the formation of impurities, and to obtain the product in a finely dispersed state.
1989-01-01
A study was made of the influence of A2 phosholipase on 22Na release from cells of nerve ganglia of edible snail. The treatment of nerve ganglia with A2 phospholipase inhibits Na, K-pump of neuronal membranes and does not exert a substantial effects on Na/Ca metabolism. There is a similarity between the effects of ionizing radiation and A2 phospholipase on the release of 22Na from cells
2010-08-26
The radionuclide 22Na is a potential astronomical observable that is expected to be produced in classical novae in quantities that depend on the thermonuclear rate of the 22Na(p,g)23Mg reaction. We have measured the strengths of low-energy 22Na(p,g)23Mg resonances directly and absolutely using a radioactive 22Na target. We find the strengths of resonances at E_p = 213, 288, 454, and 610 keV to be higher than previous measurements by factors of 2.4 to 3.2, and we exclude important contributions to the rate from proposed resonances at E_p = 198, 209, and 232 keV. The 22Na abundances expected in the ejecta of classical novae are reduced by a factor of ~ 2.
Decomposition of sodium tetraphenylborate
The chemical decomposition of aqueous alkaline solutions of sodium tetraphenylborate, NaTPB, has been investigated. The focus of the investigation is on the determination of components which influence NaTPB decomposition. Copper(II) ions, solution temperature, and solution pH (hydroxide ion concentration) have all been demonstrated to affect NaTPB stability. Their relationship with each other and the stability of NaTPB has been determined. Based upon this knowledge, a method for stabilizing NaTPB was determined. Decomposition of a NaTPB solution was delayed with the addition of sodium hydroxide. In additional work, the elimination of oxygen from the reaction environment did not prevent NaTPB decomposition in the presence of copper(II) ions but did, however, affect the course of decomposition.
Decomposition of sodium tetraphenylborate
1990-01-01
The chemical decomposition of aqueous alkaline solutions of sodium tetraphenylborate, NaTPB, has been investigated. The focus of the investigation is on the determination of components which influence NaTPB decomposition. Copper(II) ions, solution temperature, and solution pH (hydroxide ion concentration) have all been demonstrated to affect NaTPB stability. Their relationship with each other and the stability of NaTPB has been determined. Based upon this knowledge, a method for stabilizing NaTPB was determined. Decomposition of a NaTPB solution was delayed with the addition of sodium hydroxide. In additional work, the elimination of oxygen from the reaction environment did not prevent NaTPB decomposition in the presence of copper(II) ions but did, however, affect the course of decomposition.
Decomposition of sodium tetraphenylborate
1990-12-31
The chemical decomposition of aqueous alkaline solutions of sodium tetraphenylborate, NaTPB, has been investigated. The focus of the investigation is on the determination of components which influence NaTPB decomposition. Copper(II) ions, solution temperature, and solution pH (hydroxide ion concentration) have all been demonstrated to affect NaTPB stability. Their relationship with each other and the stability of NaTPB has been determined. Based upon this knowledge, a method for stabilizing NaTPB was determined. Decomposition of a NaTPB solution was delayed with the addition of sodium hydroxide. In additional work, the elimination of oxygen from the reaction environment did not prevent NaTPB decomposition in the presence of copper(II) ions but did, however, affect the course of decomposition.
Antagonistic sensory cues generate gustatory plasticity in Caenorhabditis elegans
2006-01-25
Full Text Available.Caenorhabditis elegans shows chemoattraction to 0.1–200 mM NaCl, avoidance of higher NaCl concentrations, and avoidance of otherwise attractive NaCl concentrations after prolonged exposure to NaCl (gustatory plasticity). Previous studies have shown that the ASE and ASH sensory neurons primarily mediate attraction and avoidance of NaCl, respectively. Here we show that balances between at least four sensory cell types, ASE, ASI, ASH, ADF and perhaps ADL, modulate the response to NaCl. Our results suggest that two NaCl-attraction signalling pathways exist, one of which uses Ca
Alkaline consumption mechanisms by crude oil: A comparison of sodium carbonate and sodium hydroxide
2008-01-01
Alkaline agents have an appeal for enhanced oil recovery because of their low cost and favorable performance. In this paper, sodium carbonate (Na2CO3) and sodium hydroxide (NaOH) are used as the alkaline chemicals, at the same Na2O content, to investigate the oil/water interfacial reactions between the Daqing crude oil and the alkaline solutions. Moreover, oleic acid or the mixture of ethyl acetate and phthalic acid diethyl ester were added into the crude oil, respectively, to facilitate the direct observation of the interfacial reactions and to compare the functional effectiveness of alkalis. The results showed that: Na2CO3 reacted slowly and partly with the acid components in crude oil, while NaOH did it very fast and completely. Interestingly, Na2CO3 is better than NaOH in lowering the ...
Thyroid hormones increase Na -H exchange activity in renal brush border membranes
1985-06-01
Na -H exchange activity, i.e., amiloride-sensitive Na and H flux, in renal proximal tubule brush border (luminal) membrane vesicles was increased in the hyperthyroid rat and decreased in the hypothyroid rat, relative to the euthyroid animal. A positive correlation was found between Na -H exchange activity and serum concentrations of thyroxine (T4) and triiodothyronine (T3). The thyroid status of the animal did not alter amiloride-insensitive Na uptake. The rate of passive pH gradient dissipation was higher in membrane vesicles from hyperthyroid rats compared to the rate in vesicles from hypothyroid animals, a result which would tend to limit the increase in Na uptake in vesicles from hyperthyroid animals. Na -dependent phosphate uptake was increased in membrane vesicles from hyperthyroid rats; Na -dependent D-glucose and L-proline uptakes were not changed by the thyroid status of the animal. The effect of thyroid hormones in increasing the uptake of Na in the brush border membrane vesicle is consistent with the action of the hormones in enhancing renal Na reabsorption.
Target atom excitations in collisions of He sup + and He sup 2+ with Na at q times (20--140) keV
1989-11-01
We have studied the rarget atom excitations in the collisions of He{sup +} and He{sup 2+} with Na in the energy range of {ital q}{times}(20--140) keV by optical measurements. The NaI 589.0+589.6 nm(3p {r arrow} 3s), NaI 818.3 nm (3d {r arrow} 3p) and NaI 568.8 nm (4d {r arrow} 3p) lines for He+Na collision system have been observed by an OMA system. In He{sup 2+}+Na collision system, only NaI 589.0+589.6 nm line was observed. The emission cross sections of the NaI lines observed and Na (3p) excitation cross sections are calculated. An obvious effect of coulomb potential of projectile ions on the target excitation has been observed.
2010-01-01
Introduction This in vitro study aimed to investigate the antibacterial effects of photodynamic therapy (PDT) with methylene blue (MB) or toluidine blue (TB) (both at 15 mg/mL) as a supplement to instrumentation/irrigation of root canals experimentally contaminated with Enterococcus faecalis. Methods Seventy extracted teeth had their root canals contaminated with an endodontic strain of E. faecalis for 7 days, instrumented with nickel-titanium instruments and irrigated either with 2.5% NaOCl or with 0.85% NaCl, and then randomly distributed into four experimental groups: MB/NaOCl (PDT with MB and NaOCl as the irrigant), TB/NaOCl (PDT with TB and NaOCl as the irrigant), MB/NaCl (PDT with MB and NaCl as the irrigant), and TB/NaCl (PDT with TB and NaCl as the irrigant). For PDT, the photosens...
2009-01-01
The objectives of the present study were to evaluate the effect of four eucalyptus species on (i) selected surface soil properties and (ii) the distribution of inorganic and organic phosphorus (Pi and Po) fractions. Soil samples were collected from soil 0-20 cm deep beneath and between trees. The Pi forms were determined by sequential extraction with sodium bicarbonate (NaHCO3-P), ammonium acetate (NH4OAc) (OAc-P), ammonium fluoride (NH4F-P), sodium hydroxide (NaOH)-sodium carbonate (Na2CO3) (HC-P), citrate dithionite (CD-P), and sulfuric acid (H2SO4) (H2SO4-P). The Po forms were sequentially extracted with NaHCO3 (NaHCO3-Po), NaOH (NaOH-Po), and H2SO4 (H2SO4-Po). The NaOH-Po was subdivided into moderately stable (NaOH-Pom) and highly stable Po (NaOH-Pos). Organic matter, clay and sil...
1991-12-01
This report describes a facility called NA-NET created to allow numerical analysts (na) an easy method of communicating with one another. The main advantage of the NA-NET is uniformity of addressing. All mail is addressed to the Internet host na-net.ornl.gov'' at Oak Ridge National Laboratory. Hence, members of the NA-NET do not need to remember complicated addresses or even where a member is currently located. As long as moving members change their e-mail address in the NA-NET everything works smoothly. The NA-NET system is currently located at Oak Ridge National Laboratory. It is running on the same machine that serves netlib. Netlib is a separate facility that distributes mathematical software via electronic mail. For more information on netlib consult, or send the one-line message send index'' to netlib{at}ornl.gov. The following report describes the current NA-NET system from both a user's perspective and from an implementation perspective. Currently, there are over 2100 members in the NA-NET. An average of 110 mail messages pass through this facility daily.
1991-12-01
This report describes a facility called NA-NET created to allow numerical analysts (na) an easy method of communicating with one another. The main advantage of the NA-NET is uniformity of addressing. All mail is addressed to the Internet host ``na-net.ornl.gov`` at Oak Ridge National Laboratory. Hence, members of the NA-NET do not need to remember complicated addresses or even where a member is currently located. As long as moving members change their e-mail address in the NA-NET everything works smoothly. The NA-NET system is currently located at Oak Ridge National Laboratory. It is running on the same machine that serves netlib. Netlib is a separate facility that distributes mathematical software via electronic mail. For more information on netlib consult, or send the one-line message ``send index`` to netlib{at}ornl.gov. The following report describes the current NA-NET system from both a user`s perspective and from an implementation perspective. Currently, there are over 2100 members in the NA-NET. An average of 110 mail messages pass through this facility daily.
2008-01-01
Alkaline soil is more challenging factor to grow plants than saline soil based on the size of its affected area. To reveal genetic expression changes by alkaline and saline soil, Leymus chinensis (Trin.) Tzvel. was examined response to Na2CO3 and NaCl stresses by using microarray chips comprising 1642 cDNA clones, previously reported by us. A total of 536 genes were responsive to Na2CO3 and NaCl stresses by up-regulation or down-regulation. We observed transcriptional changes arose more to Na2CO3 stress, or leaves than to NaCl stress or roots, respectively, in L. chinensis genome. Overall, 99 and 59 genes were up-regulated, while 365 and 176 genes were down-regulated in leaves and roots, respectively; demonstrating down-regulation occurs more as the response to the Na2CO3 and NaCl stress. ...
Deliquescence of NaCl-NaNO3, KNO3-NaNO3, and NaCl-KNO3 Salt Mixtures From 90 to 120?C
2004-10-20
We conducted reversed deliquescence experiments in saturated NaCl-NaNO{sub 3}-H{sub 2}O, KNO{sub 3}-NaNO{sub 3}-H{sub 2}O, and NaCl-KNO{sub 3}-H{sub 2}O systems from 90 to 120 C as a function of relative humidity and solution composition. NaCl, NaNO{sub 3}, and KNO{sub 3} represent members of dust salt assemblages that are likely to deliquesce and form concentrated brines on high-level radioactive waste package surfaces in a repository environment at Yucca Mountain, NV, USA. Discrepancy between model prediction and experimental code can be as high as 8% for relative humidity and 50% for dissolved ion concentration. The discrepancy is attributed primarily to the use of 25 C models for Cl-NO{sub 3} and K-NO{sub 3} ion interactions in the current Yucca Mountain Project high-temperature Pitzer model to describe the non-ideal behavior of these highly concentrated solutions.
Astrocytes generate Na+-mediated metabolic waves
Glutamate-evoked Na+ increase in astrocytes has been identified as a signal coupling synaptic activity to glucose consumption. Astrocytes participate in multicellular signaling by transmitting intercellular Ca2+ waves. Here we show that intercellular Na+ waves are also evoked by activation of single cultured cortical mouse astrocytes in parallel with Ca2+ waves; however, there are spatial and temporal differences. Indeed, maneuvers that inhibit Ca2+ waves also inhibit Na+ waves; however, inhibition of the Na+/glutamate cotransporters or enzymatic degradation of extracellular glutamate selectively inhibit the Na+ wave. Thus, glutamate released by a Ca2+ wave-dependent mechanism is taken up by the Na+/glutamate cotransporters, resulting in a regenerative propagation of cytosolic Na+ increases. The Na+ wave gives rise to a spatially correlated increase in glucose uptake, which is prevented by glutamate transporter inhibition. Therefore, astrocytes appear to function as a network for concerted neurometabolic coupling through the generation of intercellular Na+ and metabolic waves.
Preparation and crystal structure of NaAu/sub 3/Si and NaAu/sub 3/Ge
1980-11-01
In the course of our investigations of the ternary systems Na-Au-Si(Ge) we obtained the new compounds NaAu/sub 3/Si and NaAu/sub 3/Ge. Their crystal structure has been determined from single crystal X-ray diffraction data. They crystallize in the cubic space group Pa3 with unit cell parameters a = 891.6 pm and a = 902.1 pm, resp., and Z = 8.
Using a first-principles computational tensile test, we show that the ideal tensile strength of an Al grain boundary (GB) is reduced with both Na and Ca GB segregation. We demonstrate that the fracture occurs in the GB interface, dominated by the break of the interfacial bonds. Experimentally, we further show that the presence of Na or Ca impurity, which causes intergranular fracture, reduces the ultimate tensile strength when embrittlement occurs. These results suggest that the Na/Ca-induced intergranular embrittlement of an Al alloy originates mainly from the GB weakening due to the Na/Ca segregation.
Ionic conductivity enhancement in Na2SO4-PAN polymer composites
2005-01-01
The ionic conductivity of sodium sulfate Na2SO4-polyacrylonitrile (PAN) composites has been measured for various compositions. The ionic conductivity has been found to be enhanced up to six times with the addition of PAN polymer. The enhancement of conductivity with composite formation is strange because PAN itself is simply a matrix material. The phase transitions of Na2SO4 are observed to be dependent on the existence of PAN, only in the first heating run of Na2SO4(V). These are discussed with the peculiarities of the structural phase transitions in Na2SO4. With the addition of PAN, the mechanical properties are greatly improved
Effects of cytotoxins on intracellular Na/K balance in mouse embryonic cell
2008-01-01
Cytoplasmic Na/K imbalance induced by cytotoxic substances (ethylene glycol and cytochalasin B) was studied. Incubation in Dulbeccos medium with these cytotoxins caused changes in K and Na concentrations in the mouse two-cell embryo blastomer. The effects of both substances resulted in a drop of Na content in the embryonic cell. Washing from cytochalasin B restored the initial Na/K balance in the cytoplasm. Possible adaptive mechanisms involved in the regulation of intracellular ionic homeostasis are discussed.
1954-01-01
The toxicity of EDTA-Na, inert Sr (NO/sub 3/)/sub 2/ and Ba (NO/sub 3/)/sub 2/ has been examined. Simultaneous injection of EDTA-Na showed no significant effect upon the distribution of radio-Sr in the bones of mice. The distribution of radio-Y in the bones of mice tended to decrease following the simultaneous subcutaneous injection of /sup 91/Y and EDTA-Na.
1980-01-01
Male albino rats were subjected to acute dehydration through purging by giving tinct. podophyllum extract (7 mg/100 g body wt) through orogastric tube. Influx of 86Rb and 22Na in erythrocytes in vitro was studied both in the experimental and control group of animals. The results showed a marked increase in influx of 86Rb and a decrease in influx of 22Na in red blood cells of dehydrated rats. In vivo studies with 22Na and 86Rb showed that the absorption of Na+ and K+ from the gut takes minimum 30 min. (auth.)
Caustic Recycle from Hanford Tank Waste Using Large Area NaSICON Structures (LANS)
2009-03-31
This report presents the results of a 5-day test of an electrochemical bench-scale apparatus using a proprietary (NAS-GY) material formulation of a (Na) Super Ion Conductor (NaSICON) membrane in a Large Area NaSICON Structures (LANS) configuration. The primary objectives of this work were to assess system performance, membrane seal integrity, and material degradation while removing Na from Group 5 and 6 tank waste from the Hanford Site.
Caustic Recycle from Hanford Tank Waste Using Large Area NaSICON Structures (LANS)
2009-01-01
This report presents the results of a 5-day test of an electrochemical bench-scale apparatus using a proprietary (NAS-GY) material formulation of a (Na) Super Ion Conductor (NaSICON) membrane in a Large Area NaSICON Structures (LANS) configuration. The primary objectives of this work were to assess system performance, membrane seal integrity, and material degradation while removing Na from Group 5 and 6 tank waste from the Hanford Site
Voltage-gated Na(+) channels (Na(v)) regulate the excitability of sensory neurons and are potential targets for novel analgesics. The secreolytic ambroxol reduces pain-related behavior in rodents and alleviates pain in humans. With properties resembling those of local anesthetics, ambroxol has been reported to block Na(+) currents in sensory neurons with a preference for tetrodotoxin-resistant (TTXr) Na(+) currents encoded by Na(v)1.8. However, the molecular determinants for ambroxol-induced block of Na(+) channels and a preferential block of Na(v)1.8 opposed to tetrodotoxin-sensitive (TTXs) Na(v) alpha-subunits have not been studied in detail. By means of whole-cell voltage clamp recordings, we studied the effects of ambroxol and local anesthetics on the recombinant TTXr subunit Na(v)1.8, on TTXs Na(v) alpha-subunits and on mutants of Na(v)1.4 that are insensitive to local anesthetics. Tonic and use-dependent block by ambroxol was strongly alleviated in local anesthetic-insensitive Na(v)1.4 mutants. Use-dependent block, but not tonic block was significantly stronger on Na(v)1.8 than on TTXs channels. The TTXs subunit Na(v)1.3 displayed the least degree of use-dependent block by ambroxol. The local anesthetics mepivacaine and S(-)-bupivacaine also blocked Na(v)1.8 and TTXs channels differentially. While mepivacaine displayed a preferential use-dependent block of Na(v)1.8, S(-)-bupivacaine displayed a preference for TTXs Na(+) channels. Our data show that ambroxol acts as a typical local anesthetic on Na(+) channels interacting with specific residues in the S6 segments. This property probably meditates the analgesic effect of ambroxol. Ambroxol preferentially blocks Na(v)1.8, however shares this property with established local anesthetics like mepivacaine.
Thermodynamics of Liquid Metal Alloys Containing Sodium.
After Van der Lugt et al. suggested there is transport anomaly at eutectic concentration as 25% Na in Na-Cs system and there is suggestion too that ordering might happen at deep eutectic condition, we are interested in this case because there is nothing shown in Van der Lugt scattering experiments and Ichikawa and Granstaff's E.M.F. (though not detailed) hint nothing again in this concentration range. Our data indicate ideal mixing of Na-Cs happens in this concentration range and the energy of mixing is one-third smaller than ideal case. On the other hand, phenomenological theory has been established and found to fit experiments quite well, we hoped to see the alternative features on theory and this lead to Se and Bi. Selinium has its chain-like structure as long as thousands of atoms and its electronic behavior is very sensitive to tiny amount of impurities. We are interested in seeing interruptions of this chain-like structure by active Sodium ions but our E.M.F. data shows large scattering due to the highly corrosive character of Na-Se mixture at elevated temperatures. It is not possible to draw detailed thermodynamic information. While Bismuth shows an anomaly in the Hall coefficient on melting as does T1 it quite different from Sb as T1 differs from Ga. Since Na-T1, and Na-Ga data are available, we determined to see what will be the ionic structure and electronic environment in Na-Bi. Our data shows some similarity between Na-Bi and Na-T1 in low Na concentration range yet quite different from Na-Ga. Of course, the best mixing result occurs around 20% Na, the eutectic point in this case. There appears to be a much stronger interaction between Na and Bi atoms than Na-T1, but no compound formed in the concentration range below 46% Na.
Na+ Transport in Cardiac Myocytes; Implications for Excitation-Contraction Coupling
Intracellular Na+ concentration ([Na+]i) is very important in modulating the contractile and electrical activity of the heart. Upon electrical excitation of the myocardium, voltage-dependent Na+ channels open, triggering the upstroke of the action potential (AP). During the AP, Ca2+ enters the myocytes via L-type Ca2+ channels. This triggers Ca2+ release from the sarcoplasmic reticulum (SR) and thus activates contraction. Relaxation occurs when cytosolic Ca2+ declines, mainly due to re-uptake into the SR via SR Ca2+-ATPase and extrusion from the cell via the Na+/Ca2+ exchanger (NCX). NCX extrudes one Ca2+ ion in exchange for three Na+ ions and its activity is critically regulated by [Na+]i. Thus, via NCX, [Na+]i is centrally involved in the regulation of intracellular [Ca2+] and contractility. Na+ brought in by Na+ channels, NCX and other Na+ entry pathways is extruded by the Na+/K+ pump (NKA) to keep [Na+]i low. NKA is regulated by phospholemman, a small sarcolemmal protein that associates with NKA. Unphosphorylated phospholemman inhibits NKA by decreasing the pump affinity for internal Na+ and this inhibition is relieved upon phosphorylation. Here we discuss the main characteristics of the Na+ transport pathways in cardiac myocytes and their physiological and pathophysiological relevance.
Malic Dehydrogenase from Tamarix Roots
Soluble and mitochondrial malic dehydrogenases (MDH) were isolated from root tips of the halophyte Tamarix tetragyna L. grown in the presence and absence of NaCl. The activity of the enzymes isolated from root tips grown in the presence of NaCl was lower than that of the enzymes isolated from roots grown in absence of NaCl. The mitochondrial MDH was much more sensitive to salinity than the soluble MDH. The soluble enzyme from roots grown in NaCl had a higher Km for malate and lower Km for NAD than enzyme from the control roots. Addition of NaCl in vitro at 72 mM significantly stimulated the reductive activity of soluble MDH, while higher NaCl concentrations (240 mM and above) depressed enzyme activity. The inhibition of enzyme activity by various salts was found to be in the order MgCl2 > NaCl = KCl > Na2SO4. Mannitol at equiosmotic concentrations had no effect. Substrate inhibition, typical for oxaloacetate oxidation, was not observed at high NaCl concentrations in vitro and high substrate concentrations neutralized the inhibitory effect of NaCl. Increased coenzyme concentrations had no effect. In vitro NaCl increased the Km for malate and oxaloacetate already at relatively low concentrations. At the same time NaCl decreased the Km for NAD and NADH. The inhibitory effect of NaCl on enzyme activity seems not to be due to the effect on the Km alone. Soluble and mitochondrial MDH had different responses to pH changes, mitochondrial MDH being more sensitive. Mitochondrial MDH released from the particles had a similar response to that of the entire particles. Changes of pH modified the effect of NaCl on enzyme activity. It was postulated that NaCl apparently induces conformational changes in the enzyme.
Abnormal sodium transport in synaptosomes from brain of uremic rats.
1985-06-01
Full Text Available.The causes of central nervous system (CNS) dysfunction in uremia are not well known and are not completely reversed by dialysis. This problem was investigated in synaptosomes, which are membrane vesicles from synaptic junctions in the brain. We measured Na uptake under conditions of control, veratridine stimulation, and tetrodotoxin inhibition, in synaptosomes from normal and acutely uremic (blood urea nitrogen, 250 mg/dl) rats. In the control state, maximal Na uptake was 2.2 +/- 0.2 and 1.9 +/- 0.3 nmol/mg of protein in normal and uremic synaptosomes, respectively. With veratridine stimulation, Na uptake was increased by 1.9 and 3.6 nmol/mg of protein in normal vs. uremic rats (P less than 0.001). The increased veratridine-stimulated Na uptake observed in uremia could be due either to increased membrane permeability to Na or decrease in the Na-K ATPase pump activity. To investigate this, we studied the Na-K ATPase pump function by evaluating uptake of K (using rubidium as a tracer), uptake of Na during ATP stimulation, and inhibition of Rb and Na uptake by ouabain. In uremic rats both Rb uptake and ATP-stimulated Na uptake were significantly less than in normals (P less than 0.005). This suggests a defect in the Na-K ATPase pump. Membrane permeability for Na was then evaluated both by measuring initial Na uptake, and with addition of valinomycin. No change in Na uptake pattern was observed with valinomycin, and initial Na uptake was not significantly different in normal versus uremic synaptosomes. These data show that (a) in uremic rats veratridine-stimulated Na accumulation is significantly greater than normal; (b) the increased Na accumulation observed in uremia appears to be due to alterations in Na-K ATPase pump activity; and (c) the altered Na accumulation observed is probably not due to a uremic environment, but may be secondary to a physiologic alteration in synaptosomal function due to the uremic state. These abnormalities may affect neurotransmission and may be associated with the CNS alterations observed in uremia.
Thermal transformation of quaternary compounds in NaF-CaF2-AlF3 system
2009-01-01
Details of quaternary compounds formation in the system NaF-CaF2-AlF3 are specified. To achieve this aim, the samples of phases NaCaAlF6 and Na2Ca3Al2F14 have been obtained by high-temperature solid-phase synthesis. Their thermal behavior when heated up to 800 deg. C has been studied using the methods of high-temperature X-ray diffraction (XRD) and thermal analysis (TA). The system under consideration can be regarded as a quasibinary section CaF2-NaAlF4, where at T=745-750 deg. C invariant equilibrium is implemented with the phases CaF2-NaCaAlF6-Na2Ca3Al2F14-(liqui d melt)-(NaAlF4). The peculiarity of the equilibrium is NaAlF4 metastability at ...
1979-05-26
In this work new ABX and A/sub 2/BX phases are reported with A = Na, K, B = Cd, Hg and X = Sn, Pb. NaHgSn, NaCdSn and KHgSn phases are produced and characterized by X-ray diffraction. According to the powder sample findings NaHgSn and NaCdSn are of the same structure with a hexagonal lattice in contrast to KHgSn with a rhombic elementary cell. The systems Na/sub 2/HgSn, Na/sub 2/CdPb and Na/sub 2/HgPb crystallize with a fcc structure, whereas for Na/sub 2/CdSn a hexagonal lattice has been found. The phases K/sub 2/CdSn and K/sub 2/CdPb have been prepared with A = K. They are of the same structure and have a rhombic lattice.
2009-01-01
High aspect ratio platelike sodium niobate (NaNbO3) was successfully synthesized from precursor Bi2.5Na3.5Nb5O18 by the topochemical microcrystal conversion process. Platelike bismuth layered-perovskite Bi2.5Na3.5Nb5O18 precursor was first synthesized by the molten-salt synthesis process, and then reacted with the complementary reactant Na2CO3 in NaCl flux, the platelike Bi2.5Na3.5Nb5O18 particles were transformed into the perovskite NaNbO3 particles that preserved the morphology of Bi2.5Na3.5Nb5O18 precursor at 950 deg. C for 4 h with the weight ratio of oxide to salt 1:1.5. The length of ...
2010-01-01
The effect of sodium citrate (Na-citrate) on myosin and actin denaturation in myofibrils was investigated. Na-citrate significantly suppressed the thermal inactivation of Ca2+-ATPase of carp myosin in a concentration-dependent manner. The effect was greater than that of sorbitol. A similar effect was observed with myofibrils in which myosin is stabilized by F-actin binding. Na-citrate dissolved myofibrils at lower concentration than NaCl. Nevertheless, Na-citrate at 1M failed to denature F-actin in myofibrils, while 1M NaCl denatured F-actin almost completely. Na-citrate suppressed the NaCl-induced F-actin denaturation. Sorbitol did not show such protective effect on F-actin denaturation. Moreover, Na-citrate suppressed the freeze denaturation of myofibrils at lower concentration than sorb...
Structure and basic magnetic properties of the honeycomb lattice compounds Na2Co2TeO6 and Na3Co2SbO6
2006-09-26
The synthesis, structure, and basic magnetic properties of Na2Co2TeO6 and Na3Co2SbO6 are reported. The crystal structures were determined by neutron powder diffraction. Na2Co2TeO6 has a two-layer hexagonal structure (space group P6322) while Na3Co2SbO6 has a single-layer monoclinic structure (space group C2/m). The Co, Te, and Sb ions are in octahedral coordination, and the edge sharing octahedra form planes interleaved by sodium ions. Both compounds have full ordering of the Co2+ and Te6+/Sb5+ ions in the ab plane such that the Co2+ ions form a honeycomb array; the stacking of the honeycomb arrays differ in the two compounds. Both Na2Co2TeO6 and Na3Co2SbO6 reveal antiferromagnetic ordering at low temperatures, with a metamagnetic transition displayed by Na3Co2SbO6.
Sodium transport from blood to brain: inhibition by furosemide and amiloride
1983-10-01
Brain sodium uptake in vivo was studied using a modified intracarotid bolus injection technique in which the uptake of 22Na+ was compared with that of the relatively impermeable molecule, (3H)L-glucose. At a Na+ concentration of 1.4 mM, Na+ uptake was 1.74 +/- 0.07 times greater than L-glucose uptake. This decreased to 1.34 +/- 0.04 at 140 mM Na+, indicating saturable Na+ uptake. Relative Na+ extraction was not affected by pH but was inhibited by amiloride (Ki . 3 X 10(-7) M) and by 1 mM furosemide. The effects of these two inhibitors were additive. Brain uptake of 86Rb+, a K+ analogue, was measured to study interaction of K+ with Na+ transport systems. Relative 86Rb+ extraction was also inhibited by amiloride; however, it was not inhibited by furosemide. The results suggest the presence of two distinct transport systems that allow Na+ to cross the luminal membrane of the brain capillary endothelial cell. These transport systems could play an important role in the movement of Na+ from blood to brain.
Nucleotide requirements for sodium-sodium exchange catalysed by the sodium pump in human red cells
1. Resealed red cell ghosts containing a variety of nucleoside triphosphates, or a mixture of tri- and diphosphates, were allowed to lose 24Na into a 10 mM-K medium or a K-free high-Na medium in the presence and absence of ouabain. 2. Only ATP supported a ouabain-sensitive Na:K exchange in the 10 mM-K medium, or a ouabain-sensitive Na:Na exchange in the K-free medium. 3. Because of ATPase and adenylate kinase activity, it is difficult to control the levels of ATP and ADP inside resealed red cell ghosts. Some control was achieved by incorporating into the ghosts an ATP regenerating system consisting of creatine phosphate and creatine kinase. 4. Measurements of 24Na efflux from ghosts prepared in this way showed that ADP is required for the ouabain-sensitive exchange of Na that occurs in K-free high-Na media, but not for the normal exchange of Na for K that occurs in K-containing media. 5. The significance of these findings is discussed.
NaAlF4: Preparation, crystal structure and thermal stability
2010-01-01
The compound NaAlF4 has been obtained in the form of thin fibrous crystals or fine colorless powder by condensation at 18 deg. C of vapors arising over chiolite Na5Al3F14 or NaCaAlF6, heated up to 800 deg. C. Thermal stability has been investigated by the methods of thermal analysis and high temperature X-ray diffraction. When heated in air, NaAlF4 is stable up to 390-400 deg. C, then there is an exothermal solid state decay into Na5Al3F14(s) and AlF3(s). At higher temperature Na5Al3F14(s) decays into Na3AlF6(s) and NaAlF4(g). The crystal structure (space group Cmcm, a=3.6124(1) A, b=14.9469(7) A, c=5.2617(3) A, V=284.10 A3) has been determined by X-ray powder ...
Inelastic and reactive collisions with polarized excited Na atoms
Polarization effects in inelastic collisions of laser state-prepared Na(3/sup 2/P, M/sub J/) with Na/sup +/ leading to Na(3/sup 2/D) or Na(3/sup 2/S) are discussed for the energy range E/sub cm/ = 5-47.5eV. Studies with linearly polarized light can be explained with a simple ''locking'' model of the Na(P)-orbital. The investigations employing circularly polarized light are a very sensitive test of the models describing the nonadiabatic angular momentum coupling between electronic and nuclear motion. The dynamical effects of the electronic spin on the angular momentum transfer are discussed. Recent crossed-beam experiments on the Na + O/sub 2/ -> NaO = O reaction in the energy range E/sub cm/ = 0/3-0.8eV show a pronounced dependence on the electric electronic symmetry of Na. 17 refs., 11 figs.
Inelastic and reactive collisions with polarized excited Na atoms
1985-07-01
Polarization effects in inelastic collisions of laser state-prepared Na(3/sup 2/P, M/sub J/) with Na/sup +/ leading to Na(3/sup 2/D) or Na(3/sup 2/S) are discussed for the energy range E/sub cm/ = 5-47.5eV. Studies with linearly polarized light can be explained with a simple ''locking'' model of the Na(P)-orbital. The investigations employing circularly polarized light are a very sensitive test of the models describing the nonadiabatic angular momentum coupling between electronic and nuclear motion. The dynamical effects of the electronic spin on the angular momentum transfer are discussed. Recent crossed-beam experiments on the Na + O/sub 2/ -> NaO = O reaction in the energy range E/sub cm/ = 0/3-0.8eV show a pronounced dependence on the electric electronic symmetry of Na. 17 refs., 11 figs.
2010-01-01
ABSTRACT Using confocal microscopy, X-ray microanalysis and the scanning ion-selective electrode technique, we investigated the signalling of H2O2, cytosolic Ca2+ ([Ca2+]cyt) and the PM H+-coupled transport system in K+/Na+ homeostasis control in NaCl-stressed calluses of Populus euphratica. An obvious Na+/H+ antiport was seen in salinized cells; however, NaCl stress caused a net K+ efflux, because of the salt-induced membrane depolarization. H2O2 levels, regulated upwards by salinity, contributed to ionic homeostasis, because H2O2 restrictions by DPI or DMTU caused enhanced K+ efflux and decreased Na+/H+ antiport activity. NaCl induced a net Ca2+ influx and a subsequent rise of [Ca2+]cyt, which is involved in H2O2-mediated K+/Na+ homeostasis in salinized P. euphratica cells. When callus c...
Desulphurization of damped battery paste by sodium carbonate and sodium hydroxide
2007-09-27
The paper treats investigation of the desulphurization process of damped Pb-paste by Na{sub 2}CO{sub 3} or NaOH. There is determined the effect of Na{sub 2}CO{sub 3} (NaOH) concentration and the liquid-solid phase ratio on the process parameters (degree of desulphurization and degree of Na{sub 2}CO{sub 3} (NaOH) utilization in function of the temperature and process duration). The optimum conditions for carrying out desulphurization of Pb-pastes by Na{sub 2}CO{sub 3} or NaOH are determined in dependence of the used reactors (common reactor with laboratory agitator and rotary reactor of drum type). The content of inclusions in the solutions is examined with the purpose of producing sufficiently pure crystalline Na{sub 2}SO{sub 4} for the industry. (author)
Comparative studies of etching mechanisms of CR-39 in NaOH/H2O and NaOH/ethanol
2007-01-01
The bulk etch rate for CR-39 in NaOH/ethanol was faster than those in aqueous solution of NaOH (NaOH/H2O). Furthermore, a layer of precipitate always accumulates on the surface of CR-39 detector during etching in NaOH/ethanol, which is absent during etching in NaOH/H2O. In the present work, mass spectrometry results have shown that the same etched products are present in the etchants of NaOH/H2O and NaOH/ethanol after etching of CR-39. This shows that CR-39 has the same etching mechanism in both etchants. These etched products support the etching mechanism of scission of the carbonate ester bond in CR-39 by the hydroxide ion through basic hydrolysis of ester. The difference in the bulk etch rates can be explained in terms of the solubility of the etched products in the etchants. FTIR analyses of the solute formed from the etchants show the ...
1985-03-01
Phorbol 12-myristate 13-acetate and other phorbol esters induce an intracellular alkalinization in rat thymic lymphocytes. An extracellular acidification can be recorded concomitantly. This transmembrane H/sup +/ (equivalent) flux is dependent on external Na/sup +/ and is amiloride sensitive. Phorbol esters also stimulate an amiloride-sensitive uptake of /sup 22/Na/sup +/, suggesting activation of Na/sub 0//sup +//H/sub i//sup +/ exchange. Only those phorbol derivatives that are tumor promoters and activators of protein kinase C stimulate the antiport. Activation of the Na/sup +//H/sup +/ exchange is brought about by a change in the cytoplasmic pH sensitivity of the antiport. Activation of the Na/sup +//H/sup +/ exchanger by phorbol esters results in membrane hyperpolarization, due to indirect stimulation of the electrogenic Na/sup +//K/sup +/ pump by the increased intracellular Na/sup +/ concentrations. Increased Na/sup +//H/sup +/ exchange also produces cell swelling, which may be one of the earliest manifestations of the growth-promoting properties of the phorbol esters.
Biosynthesis of trigonelline from nicotinate mononucleotide in mungbean seedlings.
To determine the biosynthetic pathway to trigonelline, the metabolism of [carboxyl-(14)C]nicotinate mononucleotide (NaMN) and [carboxyl-(14)C]nicotinate riboside (NaR) in protein extracts and tissues of embryonic axes from germinating mungbeans (Phaseolus aureus) was investigated. In crude cell-free protein extracts, in the presence of S-adenosyl-L-methionine, radioactivity from [(14)C]NaMN was incorporated into NaR, nicotinate and trigonelline. Activities of NaMN nucleotidase, NaR nucleosidase and trigonelline synthase were also observed in the extracts. Exogenously supplied [(14)C]NaR, taken up by embryonic axes segments, was readily converted to nicotinate and trigonelline. It is concluded that the NaMN-->NaR-->nicotinate-->trigonelline pathway is operative in the embryonic axes of mungbean seedlings. This result suggests that trigonelline is synthesised not only from NAD but also via the de novo biosynthetic pathway of pyridine nucleotides.
Assessment of red cell sodium transport in essential hypertension
1982-02-01
Abnormal erythrocyte Na+ transport has been reported in patients with essential hypertension and some first-degree relatives. The two major techniques now employed for estimating Na+ transport--Na+/Li+ countertransport and Na+/K+ cotransport--are rather intricate and time consuming. Furthermore, the precise nature of the transport processes being measured is not clear. We have developed a simpler, more direct technique based on measurement of 22Na+ accumulation by erythrocytes. 22Na+ uptake by red cells from patients with essential hypertension averages twice normal. Indeed, of 21 patients with essential hypertension, only 2 patients had values within the upper end of the normal range. In 12 patients with secondary hypertension and no family history of essential hypertension, erythrocyte 22Na+ accumulation was within normal limits. Control experiments indicate that our technique for estimating red cell 22Na+ uptake is highly reproducible and shows little day-to-day variation. This procedure for the assessment of erythrocyte Na+ transport should be useful in differential diagnosis and the presymptomatic identification of individuals genetically prone to essential hypertension.
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