Sample records for anrs co3 aquitaine

  1. Incidence and Risk Factors for Severe Bacterial Infections in People Living with HIV. ANRS CO3 Aquitaine Cohort, 2000–2012

    Collin, Amandine; Le Marec, Fabien; Vandenhende, Marie-Anne; Lazaro, Estibaliz; Duffau, Pierre; Cazanave, Charles; Gérard, Yann; Dabis, François; Bruyand, Mathias; Bonnet, Fabrice


    Severe non-AIDS bacterial infections (SBI) are the leading cause of hospital admissions among people living with HIV (PLHIV) in industrialized countries. We aimed to estimate the incidence of SBI and their risk factors in a large prospective cohort of PLHIV patients over a 13-year period in France. Patients followed up in the ANRS CO3 Aquitaine cohort between 2000 and 2012 were eligible; SBI was defined as a clinical diagnosis associated with hospitalization of ≥48 hours or death. Survival analysis was conducted to identify risk factors for SBI.Total follow-up duration was 39,256 person-years [PY] (31,370 PY on antiretroviral treatment [ART]). The incidence of SBI decreased from 26.7/1000 PY [95% CI: 22.9–30.5] over the period 2000–2002 to 11.9/1000 PY [10.1–13.8] in 2009–2012 (p 50 copies/mL (Hazard Ratio [HR] = 5.1, 95% Confidence Interval: 4.2–6.2), CD4 count <500 cells/mm3 and CD4/CD8 ratio <0.8 (with a dose-response relationship for both markers), history of cancer (HR = 1.4 [1.0–1.9]), AIDS stage (HR = 1.7 [1.3–2.1]) and HCV coinfection (HR = 1.4, [1.1–1.6]). HIV-positive patients with diabetes were more prone to SBI (HR = 1.6 [0.9–2.6]). Incidence of SBI decreased over a 13-year period due to the improvement in the virological and immune status of PLHIV on ART. Risk factors for SBI include low CD4 count and detectable HIV RNA, but also CD4/CD8 ratio, HCV coinfection, history of cancer and diabetes, comorbid conditions that have been frequent among PLHIV in recent years. PMID:27050752

  2. Severe morbidity according to sex in the era of combined antiretroviral therapy: the ANRS CO3 Aquitaine Cohort.

    Mojgan Hessamfar

    Full Text Available To describe trends and determinants of severe morbidity in HIV-infected women and men.A French prospective cohort of HIV-infected patients of both sexes and all transmission categories.We used hospital admission data from January 2000 to December 2008. A severe morbid event (SME was defined as a clinical event requiring hospitalization for ≥48 h, several events could be reported during hospitalization. Yearly incidence rates of SME were estimated and compared using Generalized Estimating Equations.Among 4,987 patients (27% women, followed for a median of 8.7 years, 1,473 (30% were hospitalized (3,049 hospitalizations for 5,963 SME. The yearly incidence rate of hospitalization decreased in men, from 155 in 2000 to 80/1,000 person-years (PY in 2008 and in women, from 125 to 71/1,000 PY, (p50 years, HIV RNA >10,000 copies, CD4 <500/mm3, AIDS stage, hepatitis C co-infection and cardiovascular risk factors (diabetes, high blood pressure, and tobacco use were associated with SME.HIV-infected individuals in care in France require less and less frequently hospitalization. Women are now presenting with severe hepatic and cardio-vascular events. Disparities in SME between men and women are primarily explained by different exposure patterns to risk factors. Women should be targeted to benefit cardiovascular prevention policies as well as men.

  3. The renewable energies panorama in Aquitaine

    The Information network on the Economic Development in Aquitaine (IDEA) aims to collect and spread the environmental information concerning the Aquitaine, in order to implement an observatory of the regional environment and of the sustainable development. This panorama takes stock on the renewable energies development in Aquitaine: photovoltaic, geothermal energy, thermal solar, hydroelectricity and cogeneration. (A.L.B.)

  4. The renewable energies panorama in Aquitaine; Panorama des energies renouvelables en Aquitaine



    The Information network on the Economic Development in Aquitaine (IDEA) aims to collect and spread the environmental information concerning the Aquitaine, in order to implement an observatory of the regional environment and of the sustainable development. This panorama takes stock on the renewable energies development in Aquitaine: photovoltaic, geothermal energy, thermal solar, hydroelectricity and cogeneration. (A.L.B.)

  5. Wastes in Aquitaine. A regional guide; Les dechets en Aquitaine. Guide regional



    In the framework of French environmental policy and municipal and industrial waste disposal programs, a guide is presented for the Aquitaine region, which gives a comprehensive information on waste disposal effects and waste processing. Waste types and associated regulations are presented, with emphasis on volumes and data for Aquitaine region, followed by information on the various environmental labels and waste collection procedures, processing and ultimate disposal systems, financial incentives and taxes, waste exchange systems... The various types of municipal, industrial, agricultural and food industry wastes are reviewed with information on their characteristics, volumes, legislation, collection, processing and upgrading, and disposal

  6. The impacts of climate change in Aquitaine

    This article presents a book which addresses the impacts of climate change in the Aquitaine region by 2030-2050 in order to prepare the adaptation of the main economic sectors. Several fields are addressed: agriculture and wine-growing, forestry, estuaries, coasts and sea resources. The book examines two aspects of climate change due to greenhouse gas emissions: mitigation and adaptation. Two scenarios are studied: a global temperature increase of 2 degrees, and a global temperature increase between 4 and 5 degrees. As examples of this study, this article gives an overview of these issues of mitigation and adaptation in four domains: forests, wine-growing, air quality, and health

  7. [Intoxications specific to the Aquitaine region].

    Bédry, R; Gromb, S


    Some intoxications are more specifically linked to the Aquitaine region than to other regions of France, due to environmental circumstances (fauna, flora, climate) or traditional activities (gastronomy). Three types of intoxications are particular in this area. Pine processionary caterpillar envenomations (Thaumetopoea pityocampa), a Southern Europe pinewood parasite, are frequently encountered in the Landes' forest. They are responsible of ocular and/or skin lesions with urticaria or contact dermatitis, seldom associated with immediate IgE hypersensitivity. According to the south Atlantic coastal region geology and the marine streams, venomous marine animals are mainly located in Charente-Maritime for jellyfish, in Gironde and in Landes for weeverfish and in Atlantic Pyrenees for sea anemone. Usually not dangerous, first-aid workers treat most cases of these envenomations. Some endemic mushrooms (Tricholoma auratum) which grow on the dunes of the Atlantic coastal region, are usually considered as very good comestibles, but were recently responsible for serious intoxications: T.auratum was responsible of several cases of rhabdomyolysis, without neurological involvement, nor renal or hepatic lesion. Three deaths were notified. Animal studies confirmed the responsibility of the mushrooms. PMID:19375827

  8. 76 FR 61683 - ANR Pipeline Company; Notice of Application


    ... Energy Regulatory Commission ANR Pipeline Company; Notice of Application Take notice that on September 22, 2011, ANR Pipeline Company (ANR Pipeline), 717 Texas Street, Suite 2400, Houston, Texas 77002-2761... an offshore production platform in Mississippi Canyon Block 194 connecting with approximately...

  9. Technical meeting of OREAQ (Regional Observatory of Energy in Aquitaine): energy and greenhouse gases in Aquitaine, the system of the green certificates and the green electricity market

    The Information network on the Economic Development in Aquitaine (IDEA) aims to collect and spread the environmental information concerning the Aquitaine, in order to implement an observatory of the regional environment and of the sustainable development. This meeting is devoted to the greenhouse effect in Aquitaine. It discusses the carbon dioxide emissions bond to the energy, the green certificates and the green electricity market in France. (A.L.B.)

  10. Terroir and Cultural patrimony: reflections on regional cuisines in Aquitaine

    Isabelle Techoueyres


    Full Text Available Today the South West of France is widely renown for its cuisine and gastronomy. This presentation aims at exploring the different ingredients which contribute to the making of the concept of Regional Cuisine. It is based on field work undertaken in Aquitaine: it involved visits to families including 2 and even 3 generations in different areas, with interviews of individuals, observation, discussions. And also interviews with producers of food-products a well as persons in charge of their prom...

  11. Terroir and Cultural patrimony: reflections on regional cuisines in Aquitaine

    Isabelle Techoueyres


    Today the South West of France is widely renown for its cuisine and gastronomy. This presentation aims at exploring the different ingredients which contribute to the making of the concept of Regional Cuisine. It is based on field work undertaken in Aquitaine: it involved visits to families including 2 and even 3 generations in different areas, with interviews of individuals, observation, discussions. And also interviews with producers of food-products a well as persons in charge of their prom...

  12. « La naturopathie en Aquitaine »

    Marie-Pierre Estager


    Full Text Available Cet article sur la naturopathie en Aquitaine et plus précisément la conversion thérapeutique, a été élaboré à partir d’un travail de terrain sur lequel je me suis penchée pendant plusieurs années dans le cadre de ma thèse en anthropologie sociale et culturelle. Je me suis intéressée aux personnes qui sont passées d’un système médical conventionnel à un système de soins alternatif et naturel. En étudiant ce phénomène de « conversion thérapeutique », je les ai suivi dans leur apprentissage en n...

  13. Technical meeting of OREAQ (Regional Observatory of Energy in Aquitaine): energy and greenhouse gases in Aquitaine, the system of the green certificates and the green electricity market; Rencontre technique de l'OREAQ (Observatoire Regional de l'Energie en Aquitaine): energie et gaz a effet de serre en Aquitaine, le systeme des certificats verts et le marche de l'electricite verte



    The Information network on the Economic Development in Aquitaine (IDEA) aims to collect and spread the environmental information concerning the Aquitaine, in order to implement an observatory of the regional environment and of the sustainable development. This meeting is devoted to the greenhouse effect in Aquitaine. It discusses the carbon dioxide emissions bond to the energy, the green certificates and the green electricity market in France. (A.L.B.)

  14. 76 FR 56191 - Notice of Application; ANR Pipeline Company


    ..., operate, and maintain its Marshfield Reduction Project (MRP), comprised of a new 6,300 horsepower... County, Wisconsin, north of Stevens Point, Wisconsin, the MRP will eliminate the need for certain... Wisconsin. ANR states that the MRP will increase the reliability and flexibility of service for...

  15. An integrated approach to demonstrating the ANR pathway of proanthocyanidin biosynthesis in plants.

    Peng, Qing-Zhong; Zhu, Yue; Liu, Zhong; Du, Ci; Li, Ke-Gang; Xie, De-Yu


    Proanthocyanidins (PAs) are oligomers or polymers of plant flavan-3-ols and are important to plant adaptation in extreme environmental conditions. The characterization of anthocyanidin reductase (ANR) and leucoanthocyanidin reductase (LAR) has demonstrated the different biogenesis of four stereo-configurations of flavan-3-ols. It is important to understand whether ANR and the ANR pathway widely occur in the plant kingdom. Here, we report an integrated approach to demonstrate the ANR pathway in plants. This includes different methods to extract native ANR from different tissues of eight angiosperm plants (Lotus corniculatus, Desmodium uncinatum, Medicago sativa, Hordeum vulgare, Vitis vinifera, Vitis bellula, Parthenocissus heterophylla, and Cerasus serrulata) and one fern plant (Dryopteris pycnopteroides), a general enzymatic analysis approach to demonstrate the ANR activity, high-performance liquid chromatography-based fingerprinting to demonstrate (-)-epicatechin and other flavan-3-ol molecules, and phytochemical analysis of PAs. Results demonstrate that in addition to leaves of M. sativa, tissues of other eight plants contain an active ANR pathway. Particularly, the leaves, flowers and pods of D. uncinatum, which is a model plant to study LAR and the LAR pathways, are demonstrated to express an active ANR pathway. This finding suggests that the ANR pathway involves PA biosynthesis in D. uncinatum. In addition, a sequence BLAST analysis reveals that ANR homologs have been sequenced in plants from both gymnosperms and angiosperms. These data show that the ANR pathway to PA biosynthesis occurs in both seed and seedless vascular plants. PMID:22678031

  16. Introduction of apple ANR genes into tobacco inhibits expression of both CHI and DFR genes in flowers, leading to loss of anthocyanin

    Han, Yuepeng; Vimolmangkang, Sornkanok; Soria-Guerra, Ruth Elena; Schuyler S Korban


    Three genes encoding anthocyanidin reductase (ANR) in apple (Malus×domestica Borkh.), designated MdANR1, MdANR2a, and MdANR2b, have been cloned and characterized. MdANR1 shows 91% identity in coding DNA sequences with MdANR2a and MdANR2b, while MdANR2a and MdANR2b are allelic and share 99% nucleotide sequence identity in the coding region. MdANR1 and MdANR2 genes are located on linkage groups 10 and 5, respectively. Expression levels of both MdANR1 and MdANR2 genes are generally higher in yel...

  17. Regional trajectories of innovation in Green Chemistry: Evidence from the Aquitaine region (In French)

    Vanessa OLTRA (E3i-IFReDE-GRES); Maïder SAINT-JEAN (E3i, IFReDE-GRES)


    This article tries to apprehend the technological trajectories that develop in Aquitaine region in the field of green chemistry (GC). Breschi’s research works are used to stress that spatial patterns of innovation vary greatly amongst sectors according to the specific features of the underlying technology, as summarized by the concept of technological regime. In such a perspective, we take into account the role of industrial structures and technological regimes to apprehend regional trajector...

  18. Des pionniers autoconstructeurs aux coopérateurs : histoire des Castors en Aquitaine

    Boustingorry, Julie


    In Aquitaine, initiatives known as castorat1, a multi-faceted cooperative movement, represent a variety of alternatives to deal with inadequate public policies, when "civil society" takes action to solve the housing problem by itself. The emergence of a movement of this kind is linked to the acute nature of the housing problem, in a region in which the gradual nature of industrialization, or industrialisation douce2, has not facilitated awareness by the urban elites of the existence of this s...

  19. Dualist heresy in Aquitaine and the Agenais, c.1000-c.1249

    Taylor, Claire


    This thesis offers an account of dualist heresy in medieval Aquitaine. The first part asserts that the heresy referred to in early eleventh-century sources was dualist and originated in Balkan Bogomilism. It does this by combining two established methodologies. Through the first, reading the sources in their social context, it finds the poor experiencing increased poverty and oppression, and that some amongst the laity and clergy were observing signs prefiguring The End of historical time. No...

  20. Le patrimoine naturel aquitain vu du Web : discours, valeurs, fonctions

    Bouisset, Christine; Degrémont, Isabelle; Sevilla, Juan


    Si l’appropriation patrimoniale a longtemps été l’apanage d’acteurs scientifiques, érudits et largement institutionnels, les nouvelles technologies de communication permettent l’expression et la diffusion d’un discours patrimonial plus varié. À partir d’une étude de cas, l’Aquitaine et son traitement sur le Web, nous nous proposons donc de montrer la diversité tant dans les lieux choisis comme patrimoines que dans les acteurs au sens large qui participent au processus de patrimonialisation. L...

  1. Development of the PETawatt Aquitaine Laser system and new perspectives in physics

    Batani, D.; Koenig, M.; Miquel, J. L.; Ducret, J. E.; d'Humieres, E.; Hulin, S.; Caron, J.; Feugeas, J. L.; Nicolai, Ph; Tikhonchuk, V.; Serani, L.; Blanchot, N.; Raffestin, D.; Thfoin-Lantuejoul, I.; Rosse, B.; Reverdin, C.; Duval, A.; Laniesse, F.; Chancé, A.; Dubreuil, D.; Gastineau, B.; Guillard, J. C.; Harrault, F.; Lebœuf, D.; Le Ster, J.-M.; Pès, C.; Toussaint, J.-C.; Leboeuf, X.; Lecherbourg, L.; Szabo, C. I.; Dubois, J.-L.; Lubrano-Lavaderci, F.


    The paper describes the preparation of the short-pulse high-energy laser PETawatt Aquitaine Laser (PETAL), which will be coupled to the Laser Megajoule (LMJ) laser of CEA. The LMJ/PETAL facility will be opened for the academic access of European researchers. In parallel, diagnostics are being developed within the PETAL + project and many physical problems are being addressed ranging from the study of the problems of radiation generation and activation issues to the problem of generation of large electromagnetic pulses.

  2. A new Robertsonian translocation in Blonde d'Aquitaine cattle, rob (4; 10)

    Berland HM; Cribiu EP; Bahri-Darwich I; Darré R


    L’étude cytogénétique d’une population de bovins Blonde d’Aquitaine a permis de trouver une nouvelle translocation robertsonienne. Les chromosomes impliqués dans cette anomalie ont été déterminés à l’aide des techniques de marquage G (GTG), R (RBG) et C (CBG). Les chromosomes concernés sont le 4 et le 10. L’existence de deux vaches porteuses demi-soeurs de père indique une origine vraisemblablement paternelle de l’anomalie.

  3. Modelling of Aquitaine II pipe whipping test with the EUROPLEXUS fast dynamics code

    This paper presents a numerical simulation with the EUROPLEXUS fast dynamics software of a pipe whipping phenomenon occurring in the thermal hydraulic conditions of a loss of coolant accident in a PWR primary circuit. Different physical phenomena take place simultaneously during the rupture and the whipping of the pipe such as plasticity, contact, large displacements, two-phase flow regime and fluid structure interaction. Two kinds of numerical models - a simplified pipeline model and a mixed 1D/3D model - are considered and compared throughout modelling and computation. Numerical results are compared with experimental data belonging to the Aquitaine II test campaign

  4. Regional experience of evaluation of professional practice and quality assurance implementation in Aquitaine.

    Michel, P; Capdenat, E; Raymond, J M; Maurette, P; Daubech, L; Salamon, R; Amouretti, M


    We report the establishment of a voluntary programme for developing the assessment of professional practice and quality assurance conducted since 1989 in the Aquitaine region of south-west France. This experience, in a region where there are 14,000 hospital beds in about a hundred institutions, has aimed at two objectives: (1) the adoption by the region's health professionals of medical guidelines for good practice and methods for measuring quality and outcomes obtained, by means of university training in evaluation and the conducting of several surveys of professional practice and clinical audits; (2) similar adoption by the regional political, administrative and medical directors of quality assurance procedures defined by an organizational audit concerning the prescription of preoperative tests in the university hospital and in the main public hospitals of the region. The critical impetus that this experience has created, together with other factors related to the political decision-makers and health managers of the region, has led to an operational regional structure for developing clinical evaluation and quality in Aquitaine. PMID:9209920

  5. [Morning snack offer in kindergarten: outlook and practices in Aquitaine, France, between 2004 and 2008].

    Thibault, H; Carriere, C; Langevin, C; Atchoarena, S; Delmas, C; Baratchart, B-A; Ruello, M; Maurice-Tison, S


    The Nutrition, Prevention and Health for Children and Teenagers in Aquitaine program is a regional implementation of the French National Program of Nutrition and Health (PNNS). The first of two surveys of a representative sample of Aquitaine preschools was conducted in 2004-2005. This survey showed that more than 2/3 of teachers offered a morning snack to their pupils at around 10 o'clock in the morning, mainly composed of sweet cakes, cookies, or candies. Following this initial survey, actions were implemented starting in September 2005, aiming to stop systematic morning snacks or improve their composition. The same survey was repeated during 2007-2008 in order to analyze the changes in morning snack practices in preschools between 2004-2005 and 2007-2008. Data were collected from teachers of Aquitaine's preschools who filled out questionnaires. Schools were randomly chosen according to their size and whether or not they belonged to a priority education zone (ZEP). The results show that 57.9% of teachers organized a morning snack in 2007-2008, versus 68.7% in 2004-2005. In 2004-2005, 22% of teachers considered the morning snack as "unjustified" compared to 44% in 2007-2008. The composition of morning snacks improved: 17.7% of teachers offered fruit and/or milk in 2007-2008 versus 8.5% in 2004-2005. Morning snacks composed of other foods (such as sweets, chocolate pieces, cookies, pastries, bread, fruit juice) decreased from 60.2% in 2004-2005 to 40.2% in 2007-2008. In 2007-2008, 19% of the teachers reported that children had snacks in their schoolbag versus 34% in 2004-2005. The proportion of teachers reporting children having snacks in their schoolbag decreased from 34% in 2004-2005 to 19% in 2007-2008. Comparison between these two surveys is encouraging as it shows an improvement of the perception and practices of teachers regarding morning snacks. These results encourage the partners of this program to continue the fieldwork actions. PMID:20863673

  6. La résidence secondaire en Aquitaine : profils territoriaux

    Meyer, Anne-Marie


    Le parc de la résidence secondaire s’est constitué progressivement, privilégiant, en fonction des périodes, certains espaces ou certaines formes de construction. Il en découle une forte hétérogénéité tant spatiale que morphologique, reflet de l’évolution de la société. Ce portrait spatio-temporel du parc de la résidence secondaire sera esquissé à l’aide de l’exemple aquitain. Il est fondé sur une analyse des données issues de la base FILOCOM mise à disposition par la direction générale des Im...

  7. Gouvernance territoriale durable via les PME : L’exemple de la région Aquitaine

    Anne Musson


    A partir d’une enquête auprès de 18 PME aquitaines, nous analysons la représentation qu’elles se font du développement durable, de leurs territoires et de leurs relations avec les collectivités locales. Grâce à une analyse textuelle, nous montrons que l’hypothèse d’un développement durable local impulsé par les PME semble à ce jour réaliste. En maximisant le bien-être de la population, une politique volontariste de la part des collectivités locales constituerait alors le socle d’une attractiv...

  8. Measurement of gamma attenuation for ANR end shield model using CaSO4:Dy phosphor

    Highlights: ► Designing of Advanced Nuclear Reactor (ANR) end shield model. ► Measurement of gamma attenuation factor using CaSO4:Dy TL phosphor. ► Measurement of gamma attenuation factor under different conditions. ► Use of gamma attenuation factor for the actual end shield of ANR. ► Radiation level in the accessible area of ANR well below the permissible limit. - Abstract: In the present study, gamma attenuation factors were measured for End shield model of Advanced Nuclear Reactor (ANR). The model is of the size 700 × 700 × 1250 mm3 and made of steel ball and water mixture with 2 × 2 lattice locations at the centre of the model. The measurements were carried out using CaSO4:Dy TL phosphor. The streaming of gamma rays (includes core gamma, fission product gamma, activation gamma and capture gamma) was found to be attenuated by a factor of about 1500–4000 at a distance of 1125 mm from the incident face of the model, when it is filled with the mixture of water and steel ball. The corresponding exposure rate of streaming gamma rays was found to be about 1.2–2 R/h. The attenuation factors derived from the study was used for the designing of actual End shield for ANR

  9. Melting Relations of Multicomponent Carbonate System MgCO3 - FeCO3- CaCO3- Na2CO3 at 12-23 GPa

    Spivak, Anna; Solopova, Natalia; Litvin, Yuriy; Dubrovinsky, Leonid; Zakharchenko, Egor


    Considerable attention is focused on high-pressure high-temperature experimental study of melting phase relations of carbonates which were involved into a 'super-deep' diamond genesis. High-pressure stability of carbonate melts and their role in 'ultra-deep' diamonds genesis are most essential. Experimental study of melting relations of multicomponent carbonate system was carried out using multi-anvil press at the pressures 12 - 23 GPa and temperatures 800 to 1650 oC. Chemical compositions of starting carbonate system used for melting experiment were prepared by mixing: FeCO3 - 26,00; MgCO3- 26,00; CaCO3 - 25,00; Na2CO3 - 23,00 wt %. A region of partial melting for the system is experimentally determined. The partial melting field is arranged between low-temperature boundary of eutectics melting (solidus line) of the multicomponent carbonate and the boundary of complete melting (liquidus line) at higher temperature. From experimental observations, a Mg-Fe carbonate solid solution is the liquidus phase. At temperature lowering, the assemblage (Mg,Fe)CO3 + (Ca,Na2,Fe)CO3 + L (liquid) is formed. Then, the invariant eutectic assemblage (Mg,Fe)CO3 + (Ca,Na2,Fe)CO3 + Na2(Ca,Fe)(CO3)2+ L (liquid) which is determining for subsolidus assemblage (Mg,Fe)CO3 + (Ca,Na2,Fe)CO3 + Na2(Ca,Fe)(CO3)2 is formed. Next to liquidus line is one-phase field of completely miscible multicomponent carbonate melt. On the whole, the results demonstrate phase relations of solid carbonates and multicomponent carbonate liquid in the immediate vicinity to the low-temperature melting boundary. The early melting of the multicomponent carbonate system is compatible with the lower mantle geothermal conditions because the primary melting temperatures are noticeably below than the geothermal values. It is significant that multicomponent carbonate melts are stable and completely miscible under conditions as partial so complete melting. Thus, high-pressure high-temperature experimental data demonstrate

  10. Gouvernance territoriale et jeux de pouvoirs dans les espaces du vin en Aquitaine, Bordeaux - Bergerac - Jurançon

    Boivin, Nicolas


    The spaces of wine in Aquitaine (Bordeaux, Bergerac, Jurançon, place of sud west of France) are in mutation. They have to face the reforms of the greats institutions, in particular INAO. The territorial division becomes the spaces stake. Furthermore, to can answer at the globalized request, the producers, the traders and the others actors of the world of wine establish a governance. She pass by an implementation to a new decisional level : the ponds of production. This mode of territorial man...

  11. Global regulator Anr represses PlcH phospholipase activity in Pseudomonas aeruginosa when oxygen is limiting

    Jackson, Angelyca A.; Daniels, Emily F.; Hammond, John H.; Willger, Sven D.; Hogan, Deborah A.


    Haemolytic phospholipase C (PlcH) is a potent virulence and colonization factor that is expressed at high levels by Pseudomonas aeruginosa within the mammalian host. The phosphorylcholine liberated from phosphatidylcholine and sphingomyelin by PlcH is further catabolized into molecules that both support growth and further induce plcH expression. We have shown previously that the catabolism of PlcH-released choline leads to increased activity of Anr, a global transcriptional regulator that pro...

  12. CaCO3 and SrCO3 bioprecipitation by fungi isolated from calcareous soil.

    Li, Qianwei; Csetenyi, Laszlo; Paton, Graeme Iain; Gadd, Geoffrey Michael


    The urease-positive fungi Pestalotiopsis sp. and Myrothecium gramineum, isolated from calcareous soil, were examined for their properties of CaCO3 and SrCO3 biomineralization. After incubation in media amended with urea and CaCl2 and/or SrCl2 , calcite (CaCO3 ), strontianite (SrCO3 ), vaterite in different forms [CaCO3 , (Cax Sr1-x )CO3 ] and olekminskite [Sr(Sr,Ca)(CO3 )2 ] were precipitated, and fungal 'footprints' were observed on mineral surfaces. The amorphous precipitate mediated by Pestalotiopsis sp. grown with urea and equivalent concentrations of CaCl2 and SrCl2 was identified as hydrated Ca and Sr carbonates by Fourier transform infrared spectroscopy. Liquid media experiments showed M. gramineum possessed the highest Sr(2+) removal ability, and ∼ 49% of supplied Sr(2+) was removed from solution when grown in media amended with urea and 50 mM SrCl2 . Furthermore, this organism could also precipitate 56% of the available Ca(2+) and 28% of the Sr(2+) in the form of CaCO3 , SrCO3 and (Cax Sr1-x )CO3 when incubated in urea-amended media and equivalent CaCl2 and SrCl2 concentrations. This is the first report of biomineralization of olekminskite and coprecipitation of Sr into vaterite mediated by fungi. These findings suggest that urease-positive fungi could play an important role in the environmental fate, bioremediation or biorecovery of Sr or other metals and radionuclides that form insoluble carbonates. PMID:26119362

  13. Synthesis of the 1. ANR Energy Assessment colloquium - Which research for tomorrow's energy?

    Proposed by representatives of the main involved companies, agencies and institutions, the contributions of this colloquium addressed the following issues: the role of new energy technologies in the French and World sustainable development; The programmes 'New energy technologies'; Research priorities for these new technologies; Industry Perspectives and challenges; SMEs and the ANR; Research perspectives and challenges (electrochemical storage of energy, solar photovoltaic energy, new materials for energy, integration of renewable energies in electric systems, technological innovations for new energy technologies)

  14. [Clinical and biological effectiveness of antiretroviral therapy in the ANRS 1215 cohort].

    De Beaudrap, P; Diouf, A; Bousso Niang, K


    In 1998, the cohort ANRS 1215 was launched in Senegal with one of the first African antiretroviral treatment programs. Four hundred forty four HIV-infected adults started on ART were included between 1998 and 2004, and followed up to 2010. Mortality before 6 months was 15.6/100 person-year (PY) and associated to the initial disease severity. It decreased to 3.36/100 PY thereafter. The cumulative risks of virologic failure at 60 months and of drug resistance at 48 months were 25% and 16%, respectively. PMID:24619515

  15. Thermoluminescence of CaCO3:Dy and CaCO3:Mn

    CaCO3 samples doped with Dy and Mn were prepared in the laboratory by co-precipitation techniques. Thermoluminescence and emission spectra of these phosphors were studied and were compared with those of the naturally occuring calcite and undoped CaCO3 samples. Dy-doping seems to give a more efficient phosphor and indicates a possibility of getting a better phosphor by a judicious choice of a rare earth doping of CaCO3. Interesting result have been obtained on the TL glow curve variations of these phosphors with different temperature treatments prior to irradiation. (author)

  16. Radiolysis of Ca14CO3

    The partition-ion exclusion chromatography is evaluated to analyse non-ionic organic compounds obtained from radiolysis of high specific activity Ca14CO3. The Ca14CO3 was irradiated by β- decay of carbon-14 or by γ rays from a cobalt-60 source. The crystals were dissolved for qualitative and quantitative analysis of the radiolytic products. Formic and oxalic acids were produced in high yields. Glyoxylic, acetic and glycolic acids, formaldehyde and methanol were produced in low yields. Quantitative determination was carried out by liquid scintillation spectroscopy and the chemical yields (G-values) were calculated for the products. Mechanisms of product formation are proposed based on thermal annealing experiments. (Author)

  17. La construction d’une économie touristique sur la côte aquitaine sous la Ve république (1958-1988)

    Noailles, Mikael


    Longtemps réservé à une élite, le tourisme connaît un développement spectaculaire en Aquitaine après la Seconde Guerre mondiale. Il faut donc étudier comment par la démocratisation et la massification, le tourisme est passé de la marge au cœur du système socio-économique et politique aquitain. Cette longue période de profonds changements se traduit par l’organisation du secteur touristique à travers un réseau d’acteurs diversifié, par des mutations dans les pratiques touristiques. Le tourisme...

  18. μ +-SR studies of the weak ferromagnets CoCO 3 and NiCO 3

    Lancaster, T.; Blundell, S. J.; Pratt, F. L.; Kurmoo, M.


    We present the results of zero-field μ +-SR measurements on CoCO 3 and NiCO 3. Both compounds are rhombohedral antiferromagnets which exhibit a spontaneous weak magnetisation below 22.2 and 17.2 K, respectively. This arises due to an anisotropic superexchange (Dzyaloshinsky-Moriya) interaction. We have studied the temperature dependence of the internal field in the ordered state and the magnetic fluctuations in the paramagnetic state. We describe the possible muon-site obtained from dipolar-field calculations.

  19. ANR Corpus architecturae religiosae europeae [CARE]saec. IV-X

    Christian Sapin


    Full Text Available Le projet ANR «Corpus des monuments religieux antérieurs à l’an Mil» [Corpus architecturae religiosae europeae/CARE – IV-X saec.] a débuté en janvier 2008. Il représente l’apport de la France à un programme international, initié en 2002 par l’IRCLAMA de Zagreb (Croatie . Ce corpus a pour objectif de recenser les édifices religieux d’Europe entre le IVe siècle et le tout début du XIe siècle. Il regroupe déjà l’Italie, l’Espagne, la Croatie, l’Europe centrale et demain, probablement, l’Irlande...

  20. Gravity anomalies, spatial variation of flexural rigidity, and role of inherited crustal structure in the Aquitaine Basin

    Angrand, Paul; Ford, Mary; Watts, Anthony; Bell, Rebecca E.


    The Aquitaine foreland basin developed from Campanian to Miocene by flexure of the upper (European) plate during the Pyrenean orogeny. The foreland basin forms a syn-orogenic sedimentary wedge up to 6 km thick in the south, thinning rapidly north and has a maximum width of 200 km in the west. The flexural basin was superimposed on a lithosphere previously affected by Apto-Albian hyper-extension. What are the effects of an inherited extremely weak and narrow rifted zone on the behavior of a superimposed flexural foreland basin? Coupled with surface and subsurface data, Bouguer gravity anomalies were used to determine the crustal structure of the northern Pyrenean retrowedge and the flexure of the European plate. In the centre, the basin shows a regional Bouguer anomaly pattern typical of foreland basins with the maximum of syn-orogenic deposits corresponding to a low and the forebulge to a high. However, south of the North Pyrenean Frontal Thrust (NPFT) this regional field is overprinted by strong positive Bouguer anomalies, which correspond to high density bodies (mantle or lower crust) transported along the NPFT. Stratigraphy shows that the central basin evolved as a series of narrow, laterally variable depocentres that migrated north. Shortening is accommodated mainly by thick skinned deformation and local reactivation of salt structures. In the east, the Toulouse Fault separates the central and eastern foreland. The eastern foreland shows a broader zone of negative Bouguer values. This foreland is salt-free and stratigraphy records higher subsidence. The easternmost basin is completely overprinted by the opening of the Gulf of Lion. In the west, the foreland does not show a typical regional gravity anomaly pattern due to overprinting by the opening of the Bay of Biscay. Instead, a major gravity high is centered on the northern Landes High, with a second high centered on the Labourd massif south of the NPFT. Neither the Parentis rift basin nor the salt

  1. Dietary behaviors as associated factors for overweight and obesity in a sample of adolescents from Aquitaine, France.

    Carriere, Caroline; Langevin, Coralie; Lamireau, Thierry; Maurice, Sylvie; Thibault, Hélène


    This study aimed to identify dietary behaviors that might be considered as associated factors for overweight or obesity among French adolescents. Forty-nine of the 536 middle and high schools in Aquitaine (southwest of France) were invited to take part in the study. For each school, participating adolescents were selected using stratification by grade. A self-report questionnaire, including information about sex, age, dietary behaviors, physical and sedentary activities, and parental socioeconomic status (SES), was filled in by adolescents during class. Overweight and obesity were defined according to the age- and sex-specific body mass index cutoff points of the International Obesity Task Force. Multivariate analysis (logistic regression) was used to identify independent dietary factors associated with overweight including obesity and obesity alone (adjustment on sex, age, parental SES, and weight status and adolescents' sedentary activity). In addition to parental SES and weight status and adolescents' sedentary activity, some dietary behaviors are also independently and significantly associated with a higher prevalence of overweight including obesity: absence (OR 1.43, 0.91-2.23) or rare (OR 1.57, 1.23-2.01) breakfast intake (p importance to carry out multifaceted educational actions among adolescents, by promoting physical activity and healthy food choices in order to prevent overweight and promote healthy lifestyle behaviors. PMID:22773296

  2. The system MgCO3-FeCO3-CaCO3-Na2CO3 at 12-23 GPa: Phase relations and significance for the genesis of ultradeep diamonds

    Spivak, A. V.; Solopova, N. A.; Dubrovinsky, L. S.; Litvin, Yu. A.


    Physical-chemical experimental studies at 12-23 GPa of phase relationships within four-members carbonate system MgCO3-FeCO3-CaCO3-Na2CO3 and its marginal system MgCO3-FeCO3-Na2CO3 were carried out. The systems are quite representative for a set of carbonate phases from inclusions in diamonds within transitional zone and lower mantle. PT-phase diagrams of multicomponent carbonate systems are suggested. PT parameters of boundaries of their eutectic melting (solidus), complete melting (liquids) are established. These boundaries define area of partial melting. Carbonate melts are stable, completely mixable, and effective solvents of elemental carbon thus defining the possibility of ultra-deep diamonds generation.

  3. Knygos viršelio tekstas ir anotacija paskutiniame knygos puslapyje gretinamuoju teksto žanrų analizės požiūriu

    Kontutytė, Eglė


    Teksto žanrų tyrimai – vienas iš svarbiausių teksto lingvistikos uždavinių. Naujausiu teksto lingvistikos požiūriu žanrus tirti ir įvertinti galima tik kitų teksto žanrų apsuptyje. Knygos atveju galima kalbėti apie su knyga susijusių teksto žanrų „šeimą“, apie keletą skirtingo turinio tekstų, atliekančių panašią funkciją. Tyrimo objektu pasirinkti kalbotyros knygų viršelio tekstai ir anotacijos paskutiniame puslapyje. Tyrimo tikslas, remiantis visuminiais žanrų analizės modeliais, nustatyti š...

  4. Drug use in prisons: strategies for harm reduction (ANRS-PRIDE Program

    Laurent Michel


    Full Text Available Abstract The existence of risky practices related to drug use inside prisons is a reality everywhere and is a major issue for the community as a whole. The level of implementation of harm reduction (HR measures recommended by the World Health Organization (WHO and the United Nations Office on Drugs and Crime (UNODC is very often poor and reveals inadequate concern about public health issues in the prison environment, without any respect for the principle of equivalence for prevention and health assistance with the general community. In 2009, the French National Agency for Research on AIDS and Viral Hepatitis (ANRS developed a comprehensive research program focusing on the prevention of infectious risks in prison settings. Different steps were defined and scheduled, and included i an inventory of harm reduction (HR measures, ii a qualitative survey on the reality of risky practices, iii an assessment of the social acceptability of HR measures, and iv an intervention trial exploring the feasibility of upgrading existing HR strategies. A progressive implementation of this program has shown it is feasible, but in France, it requires tenacity, simple long-term objectives, support from a scientific authority, pedagogical interventions for all involved, as well as constant discussion with the authorities. The implementation of this program in other countries is equally simple to manage.

  5. Drug use in prisons: strategies for harm reduction (ANRS-PRIDE Program).

    Michel, Laurent


    The existence of risky practices related to drug use inside prisons is a reality everywhere and is a major issue for the community as a whole. The level of implementation of harm reduction (HR) measures recommended by the World Health Organization (WHO) and the United Nations Office on Drugs and Crime (UNODC) is very often poor and reveals inadequate concern about public health issues in the prison environment, without any respect for the principle of equivalence for prevention and health assistance with the general community. In 2009, the French National Agency for Research on AIDS and Viral Hepatitis (ANRS) developed a comprehensive research program focusing on the prevention of infectious risks in prison settings. Different steps were defined and scheduled, and included i) an inventory of harm reduction (HR) measures, ii) a qualitative survey on the reality of risky practices, iii) an assessment of the social acceptability of HR measures, and iv) an intervention trial exploring the feasibility of upgrading existing HR strategies. A progressive implementation of this program has shown it is feasible, but in France, it requires tenacity, simple long-term objectives, support from a scientific authority, pedagogical interventions for all involved, as well as constant discussion with the authorities. The implementation of this program in other countries is equally simple to manage. PMID:27383342

  6. Magnetic compressor studies for F.E.L. applications at the Centre D'Etudes Scientifiques et Techniques D'Aquitaine

    A F.E.L. (Free Electron Laser) program based on a linear induction accelerator (LINAC) is currently being developed at CESTA (Aquitaine Center of Scientific and Technical Research). This technology requires the development of high power electric pulse generators (150 kV - 2 Ω) able to work at high repetition rates (≥ 1 kHz). Limitations of conventional power components (solid-state circuit, high pressure gas blown switches, hor-ellipsis) have led the authors to design pulse generators using magnetic switches. A prototype has been built and different magnetic cores were tested in single-shot mode

  7. Review and recommended thermodynamic properties of FeCO3

    Fosbøl, Philip Loldrup; Thomsen, Kaj; Stenby, Erling Halfdan


    An extensive review of entropy, enthalpy of formation and Gibbs energy of formation, heat capacity, aqueous solubility and solubility constant of FeCO3 is given. A consistent set of thermodynamic properties for FeCO3 and relevant aqeous species is selected and recommended for use. Speciation...

  8. Melting relations of multicomponent carbonate MgCO3-FeCO3-CaCO3-Na2CO3 system at 12-26 GPa: application to deeper mantle diamond formation

    Spivak, Anna; Solopova, Natalia; Dubrovinsky, Leonid; Litvin, Yuriy


    Carbonatic components of parental melts of the deeper mantle diamonds are inferred from their primary inclusions of (Mg, Fe, Ca, Na)-carbonate minerals trapped at PT conditions of the Earth's transition zone and lower mantle. PT phase diagrams of MgCO3-FeCO3-CaCO3-Na2CO3 system and its ternary MgCO3-FeCO3-Na2CO3 boundary join were studied at pressures between 12 and 24 GPa and high temperatures. Experimental data point to eutectic solidus phase relations and indicate liquidus boundaries for completely miscible (Mg, Fe, Ca, Na)- and (Mg, Fe, Ca)-carbonate melts. PT fields for partial carbonate melts associated with (Mg, Fe)-, (Ca, Fe, Na)-, and (Na2Ca, Na2Fe)-carbonate solid solution phases are determined. Effective nucleation and mass crystallization of deeper mantle diamonds are realized in multicomponent (Mg, Fe, Ca, Na)-carbonatite-carbon melts at 18 and 26 GPa. The multicomponent carbonate systems were melted at temperatures that are lower than the geothermal ones. This gives an evidence for generation of diamond-parental carbonatite melts and formation of diamonds at the PT conditions of transition zone and lower mantle.

  9. Patrimonialisation/The making of Heritage/Présentation Axe thématique projet ANR AQAPA

    David, Béatrice


    Atelier de lancement projet ANR/AQAPA 28, 29, 30 avril 2014. Présentation des axes thématiques : Béatrice David (LAVUE-AUS, Université Paris-8) Patrimonialisation (« mise en patrimoine)/ The making of heritage/ Heritagization The study of Heritage making has become in the last 20 years a legitimate "object" in social sciences, notably in anthropology, then by geographic studies which have largely invested the field, particularly in exploring the intimate link between Territory and Heritage. T...

  10. Neutron-diffraction reinvestigation of NiCO3

    Plumier, R.; Sougi, M.; Saint-James, R.


    Detailed powder neutron-diffraction experiments performed on NiCO3 show that at low temperature this carbonate is an antiferromagnet with an antiferromagnetic direction perpendicular to the trigonal axis and not at an angle 63° to this axis as has been previously reported. The oxygen parameter is found to be u=0.2813+/-0.0005, the largest found in the series of carbonates of the iron family. A careful examination of the magnetic reflection intensities indicates in NiCO3 a form-factor expansion and a magnetic-moment reduction leading to the same covalency parameter as that previously reported in NiO and KNiF3. Comparison with the isomorphous compounds MnCO3 and CoCO3 indicates in NiCO3 an increase of the superexchange interactions, both isotropic and anisotropic, a decrease of the spin-exchange polarization through the (CO3)2- radicals, and a substantial reduction of the covalency parameter.

  11. Geothermics in Aquitaine

    The geothermal exploitation of the Aquitanian Basin (S W France) started 15 years ago and has extended today to 12 different places. Three main aquifers of different depth are exploited in Bordeaux region: the old alluvial deposits of Garonne river (20-30 m), the Middle Eocene aquifer (300-400 m), and the Cenomanian-Turonian aquifer (900-1100 m) which is the deepest and most exploited for geothermal purposes. The drinkable quality of the water and the use of single-well technique are important factors that reduce the operating costs. Geothermics remains competitive with other energy sources due to the long-term stability of geothermal energy costs. (J.S.). 2 figs., 1 tab., 5 photos

  12. Rice-like hollow nano-CaCO3 synthesis

    Ulkeryildiz, Eda; Kilic, Sevgi; Ozdemir, Ekrem


    We have shown that Ca(OH)2 solution is a natural stabilizer for CaCO3 particles. We designed a CO2 bubbling crystallization reactor to produce nano-CaCO3 particles in homogenous size distribution without aggregation. In the experimental set-up, the crystallization region was separated from the stabilization region. The produced nanoparticles were removed from the crystallization region into the stabilization region before aggregation or crystal growth. It was shown that rice-like hollow nano-CaCO3 particles in about 250 nm in size were produced with almost monodispersed size distribution. The particles started to dissolve through their edges as CO2 bubbles were injected, which opened-up the pores inside the particles. At the late stages of crystallization, the open pores were closed as a result of dissolution-recrystallization of the newly synthesized CaCO3 particles. These particles were stable in Ca(OH)2 solution and no aggregation was detected. The present methodology can be used in drug encapsulation into inorganic CaCO3 particles for cancer treatment with some modifications.

  13. Alternative solution model for the ternary carbonate system CaCO3 - MgCO3 - FeCO3 - I. A ternary Bragg-Williams ordering model

    McSwiggen, P.L.


    The minerals of the ternary carbonate system CaCO3 - MgCO3 - FeCO3 represent a complex series of solid solutions and ordering states. An understanding of those complexities requires a solution model that can both duplicate the subsolidus phase relationships and generate correct values for the activities. Such a solution model must account for the changes in the total energy of the system resulting from a change in the ordering state of the individual constituents. Various ordering models have been applied to binary carbonate systems, but no attempts have previously been made to model the ordering in the ternary system. This study derives a new set of equations that allow for the equilibrium degree of order to be calculated for a system involving three cations mixing on two sites, as in the case of the ternary carbonates. The method is based on the Bragg-Williams approach. From the degree of order, the mole fractions of the three cations in each of the two sites can be determined. Once the site occupancies have been established, a Margules-type mixing model can be used to determine the free energy of mixing in the solid solution and therefore the activities of the various components. ?? 1993 Springer-Verlag.

  14. Base documentaire sur les artisanats gallo-romains en Lyonnaise et dans les cités du nord et de l’est de l’Aquitaine : Corpus de données. Présentation Documentary base on the Gallo-Roman craft industries in the Lyonnaise region and the cities of North and East Aquitaine: Data base – presentation

    Alain Ferdière


    Full Text Available Un important corpus de tout type d’artisanat pour la période romaine a été constitué et est ici accessible en lien : il concerne l’ensemble de la province romaine de Lyonnaise (du Finistère au Lyonnais, ainsi que les cités du nord et de l’est de la grande Aquitaine, des Pictons à l’ouest au Gabales au sud-est. Ce corpus examine, par type d’artisanat, essentiellement les contextes (types de sites, chronologie, et non les aspects techniques ou typologiques concernant ces artisanats.An important body of all types of craft industries has been built up for the Roman period and is accessible here in context: it concerns the whole of the Lyonnaise Roman province (from Finistère to Lyonnais as well as the cities of the north and of greater Aquitaine, from the Pictons to the west to the Gabales to the south-east. This body essentially examines for each type of craft industry the contexts (type of site, chronology and not the technical aspects or typologies concerning the craft industries.

  15. 不同场景下ANR配置策略及实践%ANR Configuration Stratagem and Application in Different Scenarios

    曹文俊; 郑成林; 钟期洪; 刘悦


    Self Organising Network is the very important key technology in LTE system. Automatic Neighbor Relation is a ma-ture technology in LTE SON. By ANR technology the neighbor relation can be realized Self-configuration、Self-optimization and Self-operation in LTE network. ANR technology was used wireless network optimizing in Chinese Telecom Operator’s. In this paper, using different ANR strategies under different scenarios, observe the ANR technology in the LTE network optimiza-tion, optimization for LTE neighbor cell to offer reference to the study and application.%自组织网络SON是4G网络非常重要的一个关键技术(3GPPTS32、3GPP TS36)。ANR是目前比较成熟的SON技术之一,通过ANR可以实现邻区的自配置(Self-configuration)、自优化(Self-optimization)和自操作(Self-operation)。在我国三大运营商的LTE网络中均已将ANR功能上线使用。文章通过在不同场景下使用不同的ANR策略,观察ANR在LTE网络自优化中产生的作用,为LTE邻区优化的学习和应用提供参考。

  16. The decarbonation and heat capacity of ZnCO3

    Haselton, H.T.; Goldsmith, J.R.


    The decarbonation curve for ZnCO3 has been determined in the pressure range 3-20 kbar by using a combination of cold-seal vessels and piston-cylinder apparatus with NaCl assemblies. Heat capacities for both synthetic and natural ZnCO3 samples were measured by differential scanning calorimetry at temperatures ranging from 340 to 497 K. The results of these experiments indicate that the enthalpy of formation for smithsonite, ??Hf(1,298.15), is approximately -817. kJ/mol. which is about 4 kJ more negative than most tabulated values. ?? 1987.

  17. Formation of carrageenan-CaCO3 bioactive membranes.

    Nogueira, Lucas F B; Maniglia, Bianca C; Pereira, Lourivaldo S; Tapia-Blácido, Delia R; Ramos, Ana P


    The high biocompatibility and resorbability of polymeric membranes have encouraged their use to manufacture medical devices. Here, we report on the preparation of membranes consisting of carrageenan, a naturally occurring sulfated polysaccharide that forms helical structures in the presence of calcium ions. We incorporated CaCO3 particles into the membranes to enhance their bioactivity and mechanical properties. Infrared spectroscopy and X-ray diffraction data confirmed CaCO3 incorporation into the polymeric matrix. We tested the bioactivity of the samples by immersing them in a solution that mimics the ionic composition and pH of the human body fluid. The hybrid membranes generated hydroxyapatite, as attested by X-ray diffraction data. Scanning electron and atomic force microscopies aided investigation of membrane topography before and after CaCO3 deposition. The wettability and surface free energy, evaluated by contact angle measures, increased in the presence of CaCO3 particles. These parameters are important for membrane implantation in the body. Moreover, membrane stiffness was up to 110% higher in the presence of the inorganic particles, as revealed by Young's modulus. PMID:26478280


    Wen-fang Liu; Jian Yu; Zhao-xia Guo


    The encapsulation of stearic acid coated nanometer CaCO3 by a polystyrene (PS) network via emulsion polymerization is described, where γ-methacryloxypropyltrimethoxysilane (MPS) was used as an efficient crosslinker. The important factors such as the type and amount of surfactant and initiator and the content of CaCO3 are investigated as well as the role of MPS. It has been shown that little PS was extractable with only 0.6 wt% of MPS (relative to styrene). The cationic surfactant cetyl trimethylammonium bromide (CTAB) proved more effective than the anionic surfactant sodium dodecyl sulfonate (SDS). The yield rises, particles become smaller and size distribution broadens with increased amount of CTAB. It is also found that either 2,2′-azobis(isobutyronitrile) (AIBN) or ammonium persulfate (APS) is suitable for attaining high monomer conversion. With increased amount of CaCO3, the encapsulation ratio can be varied from 17.9 to 3.6, while monomer conversion and yield decrease slightly. FT-IR spectra of the products after extraction indicate tight encapsulation between PS and CaCO3, and TEM photographs of composite particles with well-defined core-shell structure give direct evidence of encapsulation.

  19. Design and Syntheses of Three Novel Carbonate Halides: Cs3 Pb2 (CO3 )3 I, KBa2 (CO3 )2 F, and RbBa2 (CO3 )2 F.

    Liu, Lili; Yang, Yun; Dong, Xiaoyu; Zhang, Bingbing; Wang, Ying; Yang, Zhihua; Pan, Shilie


    Three new carbonate halides, Cs3 Pb2 (CO3 )3 I, KBa2 (CO3 )2 F and RbBa2 (CO3 )2 F have been synthesized with hydrothermal and solid-state methods. Cs3 Pb2 (CO3 )3 I is the first product in the lead carbonate iodides family; KBa2 (CO3 )2 F and RbBa2 (CO3 )2 F are the first two centrosymmetric compounds found in the alkaline-alkaline earth carbonate fluorides family. Cs3 Pb2 (CO3 )3 I crystallizes in a centrosymmetric space group C2/m, and exhibits a two- dimensional layered structure which is formed by [Cs4 Pb4 (CO3 )6 I2 ]∞ double-layers consisting of [Pb2 (CO3 )3 I]∞ single-layers bridged by the Cs atoms. KBa2 (CO3 )2 F and RbBa2 (CO3 )2 F, which are isostructural, crystallize in a trigonal crystal system with a centric space group of R3‾ featuring a honeycomb-like framework. First principle calculations indicate that Cs3 Pb2 (CO3 )3 I has a moderate birefringence and explain the difference between the band gaps of the title compounds from electron structures. The effects of cations and halogens on the structures and properties of the title compounds are also discussed. PMID:26822173

  20. Ce2Co3Ge5: a new U2Co3Si5 - type valance fluctuating compound

    Poly crystalline sample of Ce2Co3Ge5 have been prepared by arc melting and consequently annealing at 1100 deg C. Rietveld refinement of XRD shows that it crystallize in the orthorhombic U2Co3Si5 structure (space group Ibam) with crystal parameters a= 9.802A, b= 11.777A and c= 5.941A and unit cell volume V= 684.8 A3 The unit cell volume of Ce2Co3Ge5 is seen clearly to deviate from that expected on the basis of lanthanide contraction. From susceptibility measurement, effective magnetic moment of this compound μeff = 0.95 μB which is lower than magnetic moment free for Ce3+ ions (2.54 μB) but higher than that of non-magnetic Ce4+ state (0 μB). All these results clearly indicated Ce2Co3Ge5 to be a mixed valance compound. (author)

  1. Synthesis and photocatalytic property of multilayered Co3O4

    Zhang, Dong En; Ren, Li Zheng; Hao, Xiao Yun; Pan, Bin Bin; Wang, Ming Yan; Ma, Juan Juan; Li, Feng; Li, Shu An; Tong, Zhi Wei


    Co3O4 multilayered structures were successfully synthesized by a facile poly (ethylene glycol 20000) (PEG-20000) assisted hydrothermal technique in combination with calcination method. The final Co3O4 multilayered structures inherited perfectly the morphology of the preliminarily hydrothermal products. Experimental results obtained from the different growth stages demonstrate that the as-prepared precursor exhibit an interesting time-dependent evolution of building blocks, from urchin to multilayer. The possible formation mechanism for the hierarchical structures with various architectures is presented on account of the self-assembled growth induced by Ostwald ripening. Because of the unique structured composed of slices, the photocatalytic activity of the products was examined by measuring the photodecolourisation of methyl violet solution with ultraviolet radiation. The result shows that our products have a good photocatalytic activity.

  2. Observation of superficial antiferromagnetism in Co3O4 polycrystals

    von Dreifus, Driele; Chaves Pereira, Ernesto; Aparecido de Oliveira, Adilson Jesus


    We report on a systematic study about the magnetic properties of Co3O4 polycrystals with large size distribution (100-1200 nm) and the crystallite size of 68(4) nm on average. An antiferromagnetic transition at T N = 32 K, extensively reported in the literature for Co3O4, was observed. Furthermore, another transition at T t = 14 K, which is suppressed for H ≥ 35 kOe, was also identified. An increase in the magnetic susceptibility, as well as irreversibility between zero field cooled and field cooled data below T t were observed. The non-detection of a coercive field below T t, and the fact that T t and T N are independent from the driven frequencies in ac magnetic measurements as a function of temperature, confirm that both peaks are associated to antiferromagnetic transitions.

  3. Study on Properties of PP/Nano-CaCO3 Composite%PP/Nano-CaCO3复合材料性能的研究

    高岩磊; 陈慧; 郧海丽; 崔文广


    PP/nano-CaCO3 composite was prepared by melt blending PP with nano-CaCO3. The effect of the nano-CaCO3 content on mechanical property of the PP/nano-CaC03 composite was studied. The dispersion of the nano-CaCO3 in PP matrix was analyzed by SEM. The results show that: with the increase of content of nano-CaCO3, the impact strength and the tensile strength of the PP/nano-CaCO3 composite both increase firstly and then decrease, but the flexural modulus of the PP/nano-CaCO3 composite increase evidently. The dispersion of the nano-CaCO3 in PP matrix gradually becomes bad with the increase of the content of nano-CaCO3.%采用熔融共混法制备出了聚丙烯(PP)/纳米碳酸钙(nano-CaCO3)复合材料,研究了nano-CaCO3的加入量对复合材料力学性能的影响,利用扫描电镜(SEM)分析了nano-CaCO3在PP基体中的分散性.结果表明:随着nano-CaCO3用量的增加,PP/nano-CaCO3复合材料的冲击强度和拉伸强度均呈现出先增加后降低的趋势,而弯曲模量呈增加趋势;随着填加最的增加,nano-CaCO3在PP基体中的分散性逐渐变差.

  4. Validation of modelled imaging plates sensitivity to 1-100 keV x-rays and spatial resolution characterisation for diagnostics for the "PETawatt Aquitaine Laser"

    Boutoux, G.; Batani, D.; Burgy, F.; Ducret, J.-E.; Forestier-Colleoni, P.; Hulin, S.; Rabhi, N.; Duval, A.; Lecherbourg, L.; Reverdin, C.; Jakubowska, K.; Szabo, C. I.; Bastiani-Ceccotti, S.; Consoli, F.; Curcio, A.; De Angelis, R.; Ingenito, F.; Baggio, J.; Raffestin, D.


    Thanks to their high dynamic range and ability to withstand electromagnetic pulse, imaging plates (IPs) are commonly used as passive detectors in laser-plasma experiments. In the framework of the development of the diagnostics for the Petawatt Aquitaine Laser facility, we present an absolute calibration and spatial resolution study of five different available types of IP (namely, MS-SR-TR-MP-ND) performed by using laser-induced K-shell X-rays emitted by a solid silver target irradiated by the laser ECLIPSE at CEntre Lasers Intenses et Applications. In addition, IP sensitivity measurements were performed with a 160 kV X-ray generator at CEA DAM DIF, where the absolute response of IP SR and TR has been calibrated to X-rays in the energy range 8-75 keV with uncertainties of about 15%. Finally, the response functions have been modeled in Monte Carlo GEANT4 simulations in order to reproduce experimental data. Simulations enable extrapolation of the IP response functions to photon energies from 1 keV to 1 GeV, of interest, e.g., for laser-driven radiography.

  5. PP/CaCO3复合体系力学性能研究%Mechanical Properties of PP/CaCO3 Composite

    高蕊; 王燕; 裴现勇



  6. Access to HIV care in the context of universal test and treat: challenges within the ANRS 12249 TasP cluster-randomized trial in rural South Africa

    Mélanie Plazy; Kamal El Farouki; Collins Iwuji; Nonhlanhla Okesola; Joanna Orne-Gliemann; Joseph Larmarange; France Lert; Marie-Louise Newell; François Dabis; Rosemary Dray-Spira


    Introduction: We aimed to quantify and identify associated factors of linkage to HIV care following home-based HIV counselling and testing (HBHCT) in the ongoing ANRS 12249 treatment-as-prevention (TasP) cluster-randomized trial in rural KwaZulu-Natal, South Africa. Methods: Individuals ≥16 years were offered HBHCT; those who were identified HIV positive were referred to cluster-based TasP clinics and offered antiretroviral treatment (ART) immediately (five clusters) or according to national ...

  7. Is clinical practice concordant with the changes in guidelines for antiretroviral therapy initiation during primary and chronic HIV-1 infection? The ANRS PRIMO and COPANA cohorts.

    Krastinova, Evguenia; Seng, Remonie; Yeni, Patrick; Viard, Jean-Paul; Vittecoq, Daniel; Lascoux-Combe, Caroline; Fourn, Erwan; Pahlavan, Golriz; Delfraissy, Jean François; Goujard, Cécile; Meyer, Laurence


    OBJECTIVE: Guidelines for initiating HIV treatment are regularly revised. We explored how physicians in France have applied these evolving guidelines for ART initiation over the last decade in two different situations: chronic (CHI) and primary HIV-1 infection (PHI), since specific recommendations for PHI are also provided in France. METHODS: Data came from the ANRS PRIMO (1267 patients enrolled during PHI in 1996-2010) and COPANA (800 subjects enrolled at HIV diagnosis in 2004-2008) cohorts....

  8. Acceptance rate of clinical study endpoints and adequacy of source documentation: experience from clinical study endpoint review in NEAT001/ANRS143

    Juan Berenguer; Ferdinand Wit; Jansson, Per O; Christine Schwimmer; Kowalska, Justyna D; Juliette Saillard; Alpha Diallo; Pozniak, Anton L.; François Raffi; Jesper Grarup


    Introduction: NEAT001/ANRS143 was an open-label, randomized, non-inferiority study comparing raltegravir+darunavir/r(RGV+DRV/r) vs. tenofovir/emtricitabine+darunavir/r (TDF/FTC+DRV/r) in HIV-infected antiretroviral naïve adults. Primary efficacy outcome was a composite of virological and clinical events by week 96. Materials and Methods: Clinical trial units collected and translated supporting documentation (SD) related to the investigator-reported events. A coordinator ch...

  9. Study on Properties of HDPE/Nano-CaCO3 Composite%HDPE/nano-CaCO3复合材料性能研究

    崔文广; 高岩磊; 刘会茹; 郧海丽


    HDPE/nano-CaCO3 composite was prepared by melt blending. The effect of the nano-CaCO3 content on mechanical property of the HDPE/nano-CaCO 3 composite was studied. The dispersion of the nano-CaCOj in HDPE matrix was analyzed by SEM. The results showed that the impact strength and tensile strength of the HDPE/namrCaCO3 composite both increased with the namrCaCO3 content, and then decreased with the nano-CaCOj content, but the flexural modulus of the HDPE/namrCaCO3 composite evidently increased with the nano-CaCO3 content. The dispersion of the nano-CaCO3 in HDPE matrix gradually became bad.%采用熔融共混法制备出了高密度聚乙烯( HDPE)/纳米碳酸钙(nano-CaCO3)复合材料.研究了nano-CaCO3的加入量对复合材料力学性能的影响,利用扫描电镜(SEM)分析了nano-CaCO3在HDPE基体中的分散性.结果表明,随着nano-CaCO3用量的增加,HDPE/nano-CaCO3复合材料的冲击强度和拉伸强度均呈现出先增加后降低的趋势,而弯曲模量呈增加趋势;随着用量的增加,nano-CaCO3在HDPE基体中的分散性逐渐变差.

  10. APEX CO(3-2) observations of NGC6822

    De Rijcke, S.; Buyle, P.; Cannon, J.; Walter, F.; Lundgren, A.; Michielsen, D.; Dejonghe, H.


    We observed the CO(3-2) emission of the emission-line regions HubbleI, HubbleV, HubbleX, Holmberg 18, and the stellar emission-line object S28 in NGC6822 with the ESO Atacama Pathfinder Experiment (APEX) 12m telescope as part of its science verification. The very low system temperature of 130-180K enabled us to achieve detections in 4 single pointings and in a high spatial resolution 70''x70'' map of HubbleV. We compare the spectra with HI observations, obtained with the Australia Telescope C...

  11. Influences of polymer coating nano- CaCO3 on the dispersion of nano- CaCO3 in PVC%聚合物包覆对纳米CaCO3在PVC中分散的影响

    包永忠; 史建明; 黄志明; 翁志学




    胡圣飞; 郦华兴; 严海彪



  13. CaCO3 Precipitation Potential and Its Application%CaCO3沉淀势指数及其应用




  14. 纳米CaCO3表面有机化处理%Organic modification of nano-CaCO3 surface

    张桂霞; 刘国军



  15. Electronic, optical and bonding properties of MgCO 3

    Hossain, Faruque M.; Dlugogorski, B. Z.; Kennedy, E. M.; Belova, I. V.; Murch, Graeme E.


    The electronic, optical and bonding properties of MgCO 3 (magnesite, rhombohedral calcite-type structure) are calculated using a first-principles density-functional theory (DFT) method considering the exchange-correlation function within the local density approximation (LDA) and the generalized gradient approximation (GGA). The indirect band gap of magnesite is estimated to be 5.0 eV, which is underestimated by ˜1.0 eV. The fundamental absorption edge, which indicates the exact optical transitions from occupied valence bands to the unoccupied conduction band, is estimated by calculating the photon energy dependent imaginary part of the dielectric function using scissors approximations (rigid shift of unoccupied bands). The optical properties show consistent results with the experimental calcite-type structure and also show a considerable optical anisotropy of the magnesite structure. The density of states and Mulliken population analyses reveal the bonding nature between the atoms.

  16. Effect of Morphology of Co3O4 for Oxygen Evolution Reaction in Alkaline Water Electrolysis

    Xu, Qi-Zhi; Su, Yu-Zhi; Wu, Hao; Cheng, Hui; Hui, Yun-Ping; Li, Nan; Liu, Zhao-Qing


    In this paper, three different morphological Co3O4 electrodes for oxygen evolution reaction (OER) have been synthesized. By comparing the three morphologies of Co3O4, the electrocatalytic properties show that the urchin-like spheres of Co3O4 electrode has relative low overpotential and good electrocatalysis stability, indicating that the structure of urchin-like Co3O4 spheres exhibit an easy OER for water splitting.

  17. Etude préliminaire pour l’évaluation et le suivi du niveau de qualité des viandes bovines Label Rouge d’Aquitaine, par une méthode simplifiée alternative à celle du comité français d’accréditation (COFRAC)

    Ellies-Oury, Marie-Pierre; Dauvergne, Arlette; Papillon, Sandrine; Jacob, Hervé; Picard, Brigitte; Micol, Didier


    Les Organismes de Défense et de Gestion (ODG) ont la possibilité d’utiliser une méthode alternative au programme 133 du COFRAC pour prouver la supériorité sensorielle des produits Label Rouge (LR). En Aquitaine, il existe 4 LR en viande bovine : Boeuf Blond d’Aquitain, Boeuf Excellence, Boeuf de Chalosse et Boeuf de nos Campagnes. Dans un premier temps, un jury de 16 personnes qualifiées représentant les différents maillons de chacune des filières (éleveurs, abatteurs, chevillards...

  18. Foaming of CRT panel glass powder with Na2CO3

    Petersen, Rasmus Rosenlund; König, Jakob; Smedskjær, Morten Mattrup;

    composition in question. In this work, we foam panel glass cullet using sodium carbonate (Na2CO3) as a foaming agent, and study the foaming mechanism. When heat treating Na2CO3 powder with cullet powder, Na2CO3 reacts with the glass melt and is decomposed into Na2O and CO2. The released CO2 foams the glass...

  19. The system Na2CO3-CaCO3-MgCO3 at 6 GPa and 900-1250°C and its relation to the partial melting of carbonated mantle

    Shatskiy, Anton; Litasov, Konstantin D.; Sharygin, Igor S.; Egonin, Ilya A.; Mironov, Aleksandr M.; Palyanov, Yuri N.; Ohtani, Eiji


    In order to constrain the Na2CO3-CaCO3-MgCO3 T-X diagram at 6 GPa in addition to the binary and pseudo-binary systems we conducted experiments along the Na2CO3-Ca0.5Mg0.5CO3 join. At 900-1000°C, melting does not occur and isothermal sections are presented by one-, two- and three-phase regions containing Ca-bearing magnesite, aragonite, Na2CO3 (Na2) and Na2(Ca1-0.9Mg0-0.1)3-4(CO3)4-5 (Na2Ca3-4), Na4(Ca1-0.6Mg0-0.4)(CO3)3 (Na4Ca), Na2(Ca0-0.08Mg1-0.92)(CO3)2 (Na2Mg) phases with intermediate compositions. The minimum melting point locates between 1000°C and 1100°C. This point would resemble that of three eutectics: Mgs-Na2Ca3-Na2Mg, Na2Mg-Na2Ca3-Na4Ca or Na2Mg-Na4Ca-Na2, in the compositional interval of [45Na2CO3.55(Ca0.6Mg0.4)CO3]-[60Na2CO3.40Ca0.6Mg0.4CO3]. The liquidus projection has seven primary solidification phase regions for Mgs, Dol, Arg, Na2Ca3, Na4Ca, Na2 and Na2Mg. The results suggest that extraction of Na and Ca from silicate to carbonate components has to decrease minimum melting temperature of carbonated mantle rocks to 1000-1100°C at 6 GPa and yields Na-rich dolomitic melt with a Na# (Na2O/(Na2O + CaO + MgO)) ≥ 28 mol%.

  20. Online fibre optic OSL in vivo dosimetry for quality assurance of external beam radiation therapy treatments: The ANR-TECSAN Codofer Project; Dosimetrie in vivo par OSL, en ligne par fibre optique, pour l'assurance qualite des traitements par radiotherapie externe: le projet ANR-TECSAN Codofer

    Magne, S.; Ferdinand, P. [CEA Saclay, Laboratoire de mesures optiques, CEA LIST, 91191 Gif-sur-Yvette (France); De Carlan, L. [CEA Saclay, Laboratoire national Henri-Becquerel, CEA LIST, 91191 Gif-sur-Yvette (France); Bridier, A.; Isambert, A. [Service de physique, institut Gustave-Roussy, 39, rue Camille-Desmoulins, 94805 Villejuif (France); Hugon, R. [CEA Saclay, Departement capteur, signal et informations, CEA LIST, 91191 Gif-sur-Yvette (France); Guillon, J. [Societe Fimel, 18, rue Marie-et-Pierre-Curie, 92260 Fontenay-aux-Roses (France)


    The Codofer Project (2007-2009), led under the ANR-TECSAN Call, was coordinated by CEA LIST, in partnership with IGR and the Fimel company. The aim of the project was to design and test both metrologically and in clinical conditions OSL optical fiber sensors dedicated to in vivo dosimetry during external beam radiation therapy treatment with high-energy electrons. This study, combined with the results of clinical tests obtained within the European Project Maestro, has demonstrated the advantages of OSL/FO dosimetry for providing quality assurance of treatments. However, the French market for dosimetry has greatly changed as a result of the rules decreed by the French government in 2007. The OSL/FO product is now targeted for other treatment modalities lacking suitable dosimeters (ANR-INTRADOSE Project [2009-2011]). (authors)

  1. Investigation of interaction processes in SrCO3-VOsub(1,5) and BaCO3-VOsub(1,5) systems

    Interaction of sesquioxide of vanadium with strontium and barium carbonates is of redox character. Orthovanadate and carbon oxide are formed at the initial stage of the reaction. Therefore, it seems impossible to obtain stoichiometric vanadites MV2O4 in the systems SrCo3(BaCO3)-VOsub(1.5)

  2. CaCO3粉末表面光聚合处理的研究%Photo Polymerization of Acrylamide onto CaCO3 Particle Surfaces

    雷景新; 何光健; 高峻



  3. Solubility of Np(V) in K-Cl-CO3 and Na-K-Cl-CO3 solutions to high concentrations: measurements and thermodynamic model predictions

    The solubility of Np(V) in K-Cl-CO3 and Na-K-Cl-CO3 solutions was measured to confirm a published thermodynamic model for Np(V) solubility and solubility-controlling solid phases. Undersaturation experiments starting with NpO2OH(am), KNpO2CO3(s), or Na3NpO2(CO3)2(s) were conducted in KCl + K2CO3 and NaCl + KCl + Na2CO3 solutions to high electrolyte concentrations. Steady-state dissolved Np(V) concentrations were obtained within 180 days, at which time the final solid phases were characterized by X-ray diffraction techniques. The thermodynamic model and data base, based on the Pitzer ion interaction formalism for activity coefficients, has been parameterized in the NaCl, NaClO4, NaCl-CO2(g), NaClO4-CO2(g), Na2CO3, and K2CO3 systems but has not been parameterized using data from K-Cl-CO3 and Na-K-Cl-CO3 solutions. Predictions from the thermodynamic model match measured Np(V) solubilities in K-Cl-CO3 solutions to within 0.3 log units, confirming recent parameter values. Np(V) solubilities in Na-K-Cl-CO3 solutions agree within 0.5 log units when KNpO2CO3(s) was the equilibrium solid phase. A deviation of up to 0.8 log units resulted when Na3NpO2(CO3)2(s) was the equilibrium solid phase. Additionally, the data base provides satisfactory predictions of oversaturation solubility experiments in three complex synthetic brines. This work demonstrates that thermodynamic models can provide reliable predictions of Np(V) solubility in concentrated groundwaters such as may exist in the near- and far-field environments of nuclear waste repositories located in salt beds. (orig.)


    胡圣飞; 郦华兴; 严海彪



  5. The heat resistance of a polyurethane coating filled with modified nano-CaCO3

    Li, Bin; Li, Song-Mei; Liu, Jian-Hua; Yu, Mei


    The modification of polyurethane coating by adding surface-modified CaCO3 nanoparticles (nano-CaCO3) was investigated in this paper. To improve interfacial interaction between the nano-CaCO3 and the polyurethane (PU) matrix, a silane coupling agent (KH560) was used to modify the nano-CaCO3. The grafting of KH560 on the nano-CaCO3 surfaces was characterized by the TEM, FTIR and TGA techniques. The modification of the nano-CaCO3 surfaces with KH560 was demonstrated to improve the dispersity of nano-CaCO3. FTIR, SEM and AFM were used to characterize the polyurethane coating. The FTIR spectrum indicated that the modification of nano-CaCO3 does not influence the chemical structure of the PU matrix. The roughness and gloss of the nanocomposite coatings containing various amount of nano-CaCO3 were evaluated using a roughness tester and a brightness meter. The heat resistance of the polyurethane coating containing various amounts of nano-CaCO3 was evaluated using the TGA technique. The results revealed that nano-CaCO3 treatment with KH560 improves the nanoparticle dispersion and heat-resistance of polyurethane coating.

  6. Uptake of PrEP and condom and sexual risk behavior among MSM during the ANRS IPERGAY trial.

    Sagaon-Teyssier, Luis; Suzan-Monti, Marie; Demoulin, Baptiste; Capitant, Catherine; Lorente, Nicolas; Préau, Marie; Mora, Marion; Rojas Castro, Daniela; Chidiac, Christian; Chas, Julie; Meyer, Laurence; Molina, Jean-Michel; Spire, Bruno


    The double-blind phase of the randomized ANRS IPERGAY trial, evaluating sexual activity-based oral HIV pre-exposure prophylaxis (PrEP), was conducted among high-risk men who have sex with men (MSM). Results showed an 86% (95% CI: 40-98) relative reduction in HIV incidence among participants with tenofovir disoproxil fumarate-emtricitabine vs. placebo. The present pooled analysis aimed to analyze (i) participants' adherence to the prescribed treatment and/or condom use during sexual intercourse and (ii) sexual behavior during the double-blind phase of the study. Four hundred MSM were enrolled in the trial. Every 2 months they completed online questionnaires collecting sexual behavior and PrEP adherence data regarding their most recent sexual intercourse. A total of 2232 questionnaires (M0-M24) were analyzed. Changes over time were evaluated using a mixed model accounting for multiple measures. Irrespective of sexual partner and practice type, on average, 42.6% (min: 32.1-max: 45.8%) reported PrEP use only during their most recent episode of sexual intercourse; 29% (22.9-35.6%) reported both PrEP and condom use; 11.7% (7.2-18.9%) reported condom-use only, and 16.7% (10.8-29.6%) reported no PrEP or condom use with no significant change during the study. Scheduled (i.e., correct) PrEP use was reported on average by 59.0% (47.2-68.5%) of those reporting PrEP use during their most recent sexual intercourse. Overall, 70.3% (65.3-79.4%) and 69.3% (58.3-75.4%) of participants reported, respectively, condomless anal and condomless receptive anal intercourse during their most recent sexual encounter without significant change during follow-up. Overall, on average 83.3% (min: 70.4-max: 89.2%) of participants protected themselves by PrEP intake or condom use or both during the trial, and no increase in at-risk sexual practices was observed. None of these indicators showed significant trend during the follow-up, although we found a tendency toward decrease (p = .19) of the

  7. Enhancement of the visible light activity and stability of Ag2CO3 by formation of AgI/Ag2CO3 heterojunction

    Yu, Changlin; Wei, Longfu; Zhou, Wanqin; Chen, Jianchai; Fan, Qizhe; Liu, Hong


    An insurmountable problem for silver-based semiconductor photocatalysts is their poor stability. Here, at room temperature, AgI with different concentrations (5%, 10%, 20% and 30%) were coupled into Ag2CO3, producing a series of novel AgI/Ag2CO3 composite photocatalysts. The effects of AgI addition on the Ag2CO3 catalyst for photocatalytic degradation of methyl orange (MO) under visible light irradiation have been investigated. Some physicochemical technologies like N2 physical adsorption/desorption, powder X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive X-ray (EDX) spectroscopy, X-ray photoelectron spectroscopy (XPS), and UV-vis diffuse reflectance spectroscopy (UV-vis DRS) were applied to characterize these products. Results show that the photocatalytic degradation activity of AgI/Ag2CO3 photocatalyst is much higher than that of pure AgI and Ag2CO3. With the optimal content of AgI (20 wt%), the AgI/Ag2CO3 exhibits the highest photocatalytic degradation efficiency. Its first order reaction rate constant (0.54 h-1) is 20 times of that of AgI (0.026 h-1) and 3.6 times of that of Ag2CO3 (0.15 h-1). The characterizations and theory calculation show that AgI and Ag2CO3 have suitably matched band gap structures. The formation of AgI/Ag2CO3 heterojunction with intimate interface could effectively increase the separation efficiency of the e-/h+ pairs and promote the production of •OH and O2•- radicals, which brings about the fast degradation rate of the dye and an increase in photocatalytic stability.

  8. Study of the Differences of Thermal Stability of Mg-Al-CO3 and Zn-Al-CO3 Hydrotalcite%Mg-Al-CO3与Zn-Al-CO3水滑石热稳定性差异的研究

    李蕾; 张春英; 矫庆泽; 段雪


    The structures of Mg-Al-CO3 and Zn-Al-CO3 hydrotalcites have been studied by means of XRD, IR and TG-DTA. Although both have the same crystal structures, their thermal stabilities are quite different. During the thermal decomposition process, Mg-Al-CO3 hydrotalcite exhibits two stepsdesorption of interlayer water occurs at 200℃, followed by dehydroxylation of the brucite-like layers and loss of carbonate at 400℃, Zn-Al-CO3 hydrotalcite decomposes in one step-the desorption of interlayer water, structural water and carbon dioxide occurred at the same time at 200℃. The results of a theoretical study indicate that the bond strengths of OH-CO3-OH and OH-H2O-CO3-OH in Mg-Al-CO3 hydrotalcite are stronger than those in Zn-Al-CO3 hydrotalcite. It has been shown that the thermal stability of Mg-Al-CO3 hydrotalcite is higher than that of Zn-Al-CO3 hydrotalcite

  9. Crystallinity, magnetic and electrochemical studies of PVDF/Co3O4 polymer electrolyte

    Highlights: ► PVDF–Co3O4 nanocomposite films are prepared by spin coating method. ► Porosity and crystallinity of the films are discussed. ► Magnetic properties of the films are studied. ► Presence of Co3O4 in PVDF enhanced its conductivity. - Abstract: Organic–inorganic nanocomposites are gaining importance in the recent times as polymer electrolyte membranes. In the present work, composites were prepared by combining nano sized Co3O4 and poly(vinyledene fluoride) (PVDF), using spin coating technique. The surface of the PVDF/Co3O4 system characterized through field emission scanning electron microscopy (FESEM) revealed a porous structure of the films. The nanoparticles tend to aggregate on the surface and inside the pores, leading to a decrease in the porosity with an increase in Co3O4 content. Co3O4 nanoparticles prohibit crystallization of the polymer. Differential scanning calorimetry (DSC) studies revealed a decrease in crystallinity of PVDF/Co3O4 system with an increase in the oxide content. Magnetic property studies of the composite films revealed that with an increase in Co3O4 content, the saturation magnetization values of the nanocomposites increased linearly, showing successful incorporation of the nanoparticles in the polymer matrix. Further, ionic conductivity of the composite films was evaluated from electrochemical impedance spectroscopy. Addition of Co3O4 nanoparticles enhanced the conductivity of PVDF/Co3O4 system.

  10. A facile one-pot synthesis of higher yield porphyrin functionalized Co3O4 nanoparticles

    Graphical abstract: Porphyrins functionalized Co3O4 nanoparticles were prepared firstly via a facile one-step method. The high yield of prophyrin functionalized Co3O4 nanoparticles is more than 90%. - Highlights: • Por-Co3O4 NPs were first prepared via a facile one-pot hydrothermal method. • The yield of porphyrin-Co3O4 nanoparticles is more than 90%. • FT-IR reveals the coordination interaction between porphyin molecules and Co3O4. • Ethanol and the appropriate temperature are necessary in this experiment. - Abstract: Porphyrin functionalized Co3O4 nanoparticles were first prepared via a facile one-pot hydrothermal method. The functionalized nanoparticles were characterized by X-ray diffraction and transmission electron microscopy. Fourier transform infrared spectra revealed the coordination interaction between porphyrin molecules and Co3O4. The high yield of prophyrin functionalized Co3O4 nanoparticles is more than 90%. The phase, morphology and size of as-prepared nanoparticles were dramatically affected by the ratio of solvents, temperature and porphyrins with different substituents, respectively. Experimental results revealed that ethanol and the appropriate temperature were necessary for the formation of single-phase Co3O4. Furthermore, a probable growth mechanism of the formation of porphyrin functionalized Co3O4 nanoparticles was proposed





  12. CaCO3对PE/CaCO3共混体系力学性能影响的研究

    李春艳; 董金虎



  13. Generation of Co3O4 microparticles by solution combustion method and its Zn–Co3O4 composite thin films for corrosion protection

    Graphical abstract: The pseudo-cubic cobalt oxide microparticles have been successfully synthesized by a solution combustion method using Co(NO3)2·6H2O (oxidizer) and dextrose (sugar; fuel). The as-synthesized Co3O4 microparticles are crystalline and Rietveld refinement of calcined samples exhibited cubic structure with space group of Fm3m (No. 227). The generated Co3O4 microparticles were used to fabricate Zn–Co3O4 composite thin films for corrosion protection. Highlights: ► Synthesis of pseudo-cubic Co3O4 microparticles by solution combustion method. ► As-prepared Co3O4 compounds are calcined and structurally characterized. ► Prepared Co3O4 are utilized for the fabrication of Zn–Co3O4 composite thin films. - Abstract: Microcrystalline cobalt oxide (Co3O4) powder was successfully synthesized by a simple, fast, economical and eco-friendly solution-combustion method. The as-synthesized powder was calcined for an hour at temperatures ranging from 100 to 900 °C. The crystallite size, morphology, and chemical state of synthesized powders were characterized by powder XRD, TG-DTA, XPS, SEM/EDAX, TEM and FT-IR spectral methods. The as-synthesized Co3O4 powder was single-crystalline and Rietveld refinement of calcined samples exhibited cubic structure with space group of Fm3m (No. 227). The effect of calcination temperature on crystallite size and morphology was assessed. Scanning electron micrographs show a uniform, randomly oriented pseudo-cubic particle with porous like morphology and EDAX measurement showed its chemical composition. Thermal behavior of as-synthesized compound was examined. The TEM result revealed that, the particles are pseudo-cubic in nature with diameter of 0.2–0.6 μm and a length of 0.9–1.2 μm. The crystallite size increased with increase of calcination temperature. The synthesized Co3O4 powder was used to fabricate Zn–Co3O4 composite thin films and its corrosion behavior was analyzed by anodic polarization, tafel extrapolation

  14. Hydrocalcite (CaCO3 * H2O) and Nesquehonite (MgCO3 * 3H2O) in Carbonate Scales.

    Marschner, H


    Hydrocalcite (CaCO(3) * H(2)O) with exactly one molecule of hydrate water is the main component of carbonate scales deposited from cold water in contact with air. When the magnesium content of the water is high, the hydrocalcite occurs together with MgCO(3) * 3H(2)O (nesquehonite). From the conditions under which hydrocalcite is transformed into calcite and aragonite, it appears that in some cases aragonite in nature may be formed by way of an intermediary of CaCO(3) * H(2)O. PMID:17779803

  15. High-temperature heat capacity of Co3O4 spinel: thermally induced spin unpairing transition

    Mocala, K.; Navrotsky, A.; Sherman, David M.


    A strong anomaly was found in the heat capacity of Co3O4 between 1000 K and the decomposition temperature. This anomaly is not related to the decomposition of Co3O4 to CoO. The measured entropy of transition, ??S=46??4 J mol-1 K-1 of Co3O4, supports the interpretation that this anomaly reflects a spin unpairing transition in octahedrally coordinated Co3+ cations. Experimental values of heat capacity, heat content and entropy of Co3O4 in the high temperature region are provided. The enthalpy of the spin unpairing transition is 53??4 kJ mol-1 of Co3O4. ?? 1992 Springer-Verlag.

  16. 超微细CaCO3结晶的控制生长%Growth Control of Ultrafine CaCO3

    林荣毅; 张家芸; 张培新


    通过SEM显微技术,从亚微观结构研究Na5P3O10对Ca(OH)2碳化反应中CaCO3结晶的控制生长过程.结果表明,CaCO3结晶的成核、生长在时间上是重叠的伴随过程.在CaCO3反应结晶的起始阶段,Na5P3O10的存在促进了CaCO3的大量成核.通过SEM可以观测到大量亚稳态CaCO3籽晶(R=23~26nm)的存在.这时,CaCO3晶体生长并不符合Zener-Ham理论的扩散生长规律.结晶生长由穿越晶体界面的短程扩散控制.在反应结晶末期,SEM已观测不到亚稳态CaCO3籽晶的存在.CaCO3结晶生长遵循长程扩散控制模型R(t)=λi(Dt)n,时间指数n=0.4874~0.4992(理论值n=0.5).随着碳化液中Na5P3O10浓度的增大,常数λiDn由16.69降低至11.36,从而有效地控制CaCO3的结晶生长.%The ultrafine CaCO3 crystal growth controlled by Na5P3O10 in the carbonation of Ca(OH)2 suspension,was investigated by using SEM. The results show that CaCO3 nucleates along with the nucleus growth. The presence of Na5P3O10 accelerates the CaCO3 nucleation. At the initial stage,a large number of CaCO3 nucleus engender,and metastable tiny crystallites (R=2326nm) can be observed in SEM imagine. The CaCO3 crystal growth controlled by short distance diffusion when mass pass through the crystal interface,does not correspond to Zener-Ham theory. At the next stage,the metastable tiny crystallites disappear in SEM imagine. The CaCO3 crystal growth abides by the long distance control model R(t)=λi(Dt)n,in which the time coefficient n is 0.4874~0.4992 (theory value n=0.5) and the constant λiDn decreases from 16.69 to 11.36. Consequently,Na5P3O10 can effectively inhabit the CaCO3 crystal growth.

  17. Carbon Dioxide Activation by Scandium Atoms and Scandium Monoxide Molecules: Formation and Spectroscopic Characterization of ScCO3 and OCScCO3 in Solid Neon.

    Zhang, Qingnan; Qu, Hui; Chen, Mohua; Zhou, Mingfei


    The reactions of carbon dioxide with scandium monoxide molecules and scandium atoms are investigated using matrix isolation infrared spectroscopy in solid neon. The species formed are identified by the effects of isotopic substitution on their infrared spectra as well as density functional calculations. The results show that the ground state ScO molecule reacts with carbon dioxide to form the carbonate complex ScCO3 spontaneously on annealing. The ground state Sc atom reacts with two carbon dioxide molecules to give the carbonate carbonyl complex OCScCO3 via the previously reported OScCO insertion intermediate on annealing. The observation of these spontaneous reactions is consistent with theoretical predictions that both the Sc + 2CO2 → OCScCO3 and ScO + CO2 → ScCO3 reactions are thermodynamically exothermic and are kinetically facile, requiring little or no activation energy. PMID:26738558

  18. In Situ Investigations into CaCO3 Nucleation

    Nielsen, Michael Harold

    predictions of classical nucleation theory to this system. Low resolution microscopy techniques are further used to provide indirect evidence for the formation pathways of calcite on SAMs exhibiting different surface chemistries. The development of a platform for liquid phase transmission electron microscopy (TEM) utilizing a sealed liquid cell is described, and its utility in making novel observations of materials formation processes is demonstrated. Liquid phase TEM is further employed, using an open cell system which allows for mixing reagents, to directly observe formation pathways in the CaCO3 system.

  19. Nucleation kinetics of nesquehonite (MgCO 3·3H 2O) in the MgCl 2-Na 2CO 3 system

    Cheng, Wenting; Li, Zhibao


    The nucleation of nesquehonite (MgCO 3·3H 2O) in MgCl 2-Na 2CO 3 system with and without the addition of NaCl was studied within a supersaturation range of 1.06-1.48 at 288.15-308.15 K. The supersaturation ( S) of MgCO 3·3H 2O was exactly calculated by aqueous (H + ion) model through OLI platform. The conductivity method was applied in this experiment to determine the induction period of MgCO 3·3H 2O. The effects of temperature, supersaturation, and presence of additive (NaCl) on the induction period of MgCO 3·3H 2O were studied experimentally. As expected from theory, it was found that the induction period decreases when either temperature or supersaturation increases. The induction period was prolonged by adding NaCl in solutions at a constant supersaturation. From the dependence of the induction period on temperature and supersaturation, it was possible to distinguish between the homogeneous and heterogeneous nucleation mechanisms. At last, the activation energy ( Eact) for MgCO 3·3H 2O crystallization and the interfacial tension between MgCO 3·3H 2O and aqueous solutions of homogeneous ( γS,hom) and heterogeneous ( γS,het) nucleation were calculated from measurements of the induction period for the MgCO 3·3H 2O nucleation with and without the addition of NaCl.

  20. Heat capacities and entropies of rhodochrosite (MnCO3) and siderite (FeCO3) between 5 and 600 K.

    Robie, R.A.; Haselton, H.T., Jr.; Hemingway, B.S.


    The heat capacities of rhodochrosite, (Mn0.994Fe0.005Mg0.001)CO3, and siderite, 171(Fe0.956Mn0.042Mg0.002)CO3, were measured between 5 and 550 K by combined cryogenic-adiabatic and differential scanning calorimetry. These new data were used to reanalyse the thermodynamic properties of these phases.-J.A.Z.

  1. Dynamics of fossil fuel CO2 neutralization by marine CaCO3

    Archer, David; Kheshgi, Haroon; Maier-Reimer, Ernst


    A detailed model of the ocean circulation and carbon cycle was coupled to a mechanistic model of CaCO3 diagenesis in deep sea sediments to simulate the millennium-scale response of the oceans to future fossil fuel CO2 emissions to the atmosphere and deep sea. Simulations of deep sea injection of CO2 show that CaCO3 dissolution is sensitive to passage of high-CO2 waters through the Atlantic Ocean, but CaCO3 dissolution has a negligible impact on atmospheric pCO2 or the atmospheric stabilization CO2 emission in the coming centuries. The ultimate fate of the fossil fuel CO2 will be to react with CaCO3 on the seafloor and on land. An initial CaCO3 dissolution spike reverses the net sedimentation rate in the ocean until it is attenuated by an enhanced vertical gradient of alkalinity after about 1000 years. The magnitude of the initial spike is sensitive to assumptions about the kinetics for CaCO3 dissolution, but subsequent behavior appears to be less model dependent. Neutralization by seafloor CaCO3 occurs on a timescale of 5-6 kyr, and is limited to at most 60-70% of the fossil fuel release, even if the fossil fuel release is smaller than the seafloor erodible inventory of CaCO3. Additional neutralization by terrestrial CaCO3 restores a balance between CaCO3 weathering and seafloor accumulation on a timescale of 8.5 kyr, while the deficit of seafloor CaCO3 (the lysocline) is replenished with an e-folding timescale of approximately 18 kyr. The final equilibrium with CaCO3 leaves 7-8% of the fossil fuel CO2 remaining in the atmosphere, to be neutralized by the silicate rock cycle on a time frame of hundreds of thousands of years.

  2. The Effect of Ionic Liquids on the CaCO3 Crystal Growth

    Zhi Guo HU; Shi Li SONG; Jian Ji WANG; Lin YANG


    In this paper, the effect of ionic liquids on the CaCO3 crystal growth has been studied for the first time. The obtained CaCO3 crystals were charactered by the X-ray diffraction and scanning electron micrographs. The results showed that the control ability of ionic liquids for CaCO3 crystals growth was dependent on the counter anion very much.

  3. Carbon nanotube/Co3O4 composite for air electrode of lithium-air battery

    Yoon, Taek Han; Park, Yong Joon


    A carbon nanotube [CNT]/Co3O4 composite is introduced as a catalyst for the air electrode of lithium-air [Li/air] batteries. Co3O4 nanoparticles are successfully attached to the sidewall of the CNT by a hydrothermal method. A high discharge capacity and a low overvoltage indicate that the CNT/Co3O4 composite is a very promising catalyst for the air electrode of Li/air batteries.

  4. Uniaxial magnetic anisotropy of rhombohedral CoCO3 crystals at T = 0 K

    Men'shikov, V. V.; Rudenko, V. V.; Tugarinov, V. I.; Vorotynov, A. M.; Ovchinnikov, S. G.


    A method for calculating the contribution of exchange interaction to uniaxial anisotropy with the use of g' factors has been worked out using CoCO3 crystals as an example. The calculated contribution of dipole-dipole interactions to the anisotropy of CoCO3 is 0.93 cm-1. The sum of the contributions to the anisotropy constant of CoCO3 with the inclusion of the dipole-dipole interactions is 36.1 cm-1.


    Zhao-xia Guo; Jian Yu


    Nanometer calcium carbonate was modified with Frechet type polyether dendrons bearing a COOH group at the focal point by a wet-coating technique in dichloromethane at room temperature. The interaction between CaCO3 and the dendritic modifier was proven by IR and mass spectroscopy of the modified CaCO3 after thorough extraction with dichloromethane. The amount of tightly bonded organic modifier was estimated by TGA. It was shown that the amount of bonded molecules decreased with increasing generation number due to the larger number of branches. Compared to unmodified CaCO3, the modified CaCO3 possess different dispersibility in water and in organic solvents.

  6. Compound Method to Disperse CaCO3 Nanoparticles to Nano-Size in Water.

    Gu, Sui; Cai, Jihua; Wang, Jijun; Yuan, Ye; Chang, Dewu; Chikhotkin, Viktor F


    The invalidation of CaCO3 nanoparticles (nCaCO3) is often caused by the fact of agglomeration and inhomogeneous dispersion which limits its application into water-based drilling muds for low permeability reservoirs such as coalbed methane reservoir and shale gas/oil reservoir. Effective methods to disperse nCaCO3 to nano-size (≤ 100 nm) in water have seldom been reported. Here we developed a compound method containing mechanical stirring, ultrasonic treatment, the use of surfactant and stabilizer to disperse nCaCO3 in water. It comprises the steps adding 2% nCaCO3, 1% sodium dodecyl sulfonate (SDS), 2% cetyltrimethyl ammonium bromide (CTAB), 2% OP-10, 3% to 4% biopolymer (XC) in water successively, stirring it at a shear rate of 6000 to 8000 r/min for 15 minutes and treating it with ultrasonic at a frequency of 28 KHz for 30 to 40 minutes. The dispersed nCaCO3 was characterized with scanning electron microscope (SEM), transmission electron microscope (TEM) and particle size distribution (PSD) tests. We found that nCaCO3 could be dispersed to below 100 nm in water and the medium value of nCaCO3 was below 50 nm. This method paved the way for the utilization of nCaCO3 in drilling fluid and completion fluid for low permeability reservoirs such as coal seams and shale gas/oil formations. PMID:26682370

  7. Early changes in coagulation but not inflammatory biomarkers under intermittent ART: the randomized ANRS 106 WINDOW trial

    Sébastien Gallien


    Full Text Available Introduction: In the SMART trial, baseline plasma hsCRP, IL6 and D-dimer levels were strongly correlated to all-cause mortality. A case-control study has shown an increase of IL-6 and D-dimer levels after one month of antiretroviral therapy (ART interruption, which was correlated to viral load. Restarting ART was associated to a decrease in D-dimer but not IL-6 or hsCRP levels. We assessed biomarkers levels up to 96 weeks in ART-experienced adults with plasma HIV RNA levels <400 c/mL randomized in the ANRS 106 WINDOW trial to intermittent ART (IT: six cycles of eight weeks of ART interruption followed by eight weeks of ART versus continuous treatment (CT. Methods: Stored plasma for 160 participants (80 IT and 80 CT, matched by age, sex and CDC classification, were analyzed blinded for IL-6, sCD-14, hsCRP and D-dimer levels at baseline, week 8 (IT group only, week 16 and week 96. Lower levels of detection for IL-6, sCD14, hsCRP and D-Dimer were 1.5 pg/mL, 250 ng/mL, 0.03 µg/mL and 0.21 µg/mL, respectively. The primary objective was to compare changes in IL-6, hsCRP, sCD14 and D-dimer plasma levels from baseline to week 8, 16 and 96 in the IT and CT arms. Biomarkers levels were log10 transformed prior to analysis. Results: At baseline, patients were mostly men (86%, with a median age of 40 years, a CD4+ T-cell count of 768/mm3, have received a median of 4.7 years of ART and 85% had HIV RNA <50 c/mL. Proportion of patients with plasma HIV RNA levels<400 c/mL were 6% and 99%, 81% and 97%, 86% and 92% at weeks 8, 16 and 96 in the IT and CT arms, respectively. Plasma biomarkers levels are shown in the Table 1.Compared to baseline, D-dimer levels significantly increased 8 weeks after ART interruption in the IT arm (+23% fold change, 95% CI +9% to +39% but reverted to baseline levels at week 16 and remained unchanged at week 96. There was no significant change from baseline in the other biomarker levels in the IT arm. Similarly, no significant change

  8. Chemical and biological characterization of new Re(CO)3/[99mTc](CO)3 bombesin analogues

    Introduction: Bombesin, a neuropeptide with potential for breast and prostate tumor targeting, is rapidly metabolized in vivo, and as a result, uptake in tumor xenografts in mice is poor. An improvement can be expected from the introduction of nonnatural amino acids and spacers. Leu13 was replaced by cyclohexylalanine and Met14 by norleucine. Two spacers, -βAla-βAla- and 3,6-dioxa-8-aminooctanoic acid, were inserted between the receptor-binding amino acid sequence (7-14) of bombesin (BBS) and the retroNα-carboxymethyl histidine chelator used for labeling with the [99mTc](CO)3 core and the rhenium (Re) congener. Methods: The biological characterization of the new compounds was performed both in vitro on prostate carcinoma PC-3 cells (binding affinity, internalization/externalization) and in vivo (biodistribution in nude mice with tumor xenografts). The stability was also investigated in human plasma. The Re analogues were prepared for chemical characterization. Results: The nonnatural amino acids led to markedly slower degradation in human plasma and PC-3 cell cultures. The receptor affinity of the new technetium 99m ([99mTc])-labeled BBS analogues was similar to the unmodified compound with K d<1 nM. Uptake in the pancreas and in PC-3 tumor xenografts in nude mice was blocked by unlabeled BBS. The best target-to-nontarget uptake ratio was clearly due to the presence of the more polar spacer, -βAla-βAla-. Conclusions: The different spacers did not have a significant effect on stability or receptor affinity but had a clear influence on the uptake in healthy organs and tumors. Uptake in the kidneys was lower than in the liver, which is likely to be due to the lipophilicity of the compounds. A specific, high uptake was also observed in the gastrin-releasing peptide receptor-rich pancreas. Thus, with the introduction of spacers the in vivo properties of the compounds can be improved while leaving the affinity unaffected

  9. Role of baseline HIV-1 DNA level in highly-experienced patients receiving raltegravir, etravirine and darunavir/ritonavir regimen (ANRS139 TRIO trial.

    Charlotte Charpentier

    Full Text Available OBJECTIVE: In the ANRS 139 TRIO trial, the use of 3 new active drugs (raltegravir, etravirine, and darunavir/ritonavir, resulted in a potent and sustained inhibition of viral replication in multidrug-resistant treatment-experienced patients. The aim of this virological sub-study of the ANRS 139 TRIO trial was to assess: (i the evolution of HIV-1 DNA over the first year; and (ii the association between baseline HIV-1 DNA and virological outcome. METHODS: Among the 103 HIV-1-infected patients included in the ANRS-139 TRIO trial, HIV-1 DNA specimens were available for 92, 84, 88, and 83 patients at Week (W0, W12, W24, and W48, respectively. Quantification of total HIV-1 DNA was performed by using the commercial kit "Generic HIV DNA Cell" (Biocentric, Bandol, France. RESULTS: Baseline median HIV-1 DNA of patients displaying virological success (n= 61, viral blip (n= 20, and virological failure (n = 11 were 2.34 log(10 copies/10(6 PBMC (IQR= 2.15-2.66, 2.42 (IQR = 2.12-2.48, and 2.68 (IQR= 2.46-2.83, respectively. Although not statistically significant, patients exhibiting virological success or viral blip had a tendency to display lower baseline HIV-1 DNA than patients experiencing virological failure (P = 0.06. Median decrease of HIV-1 DNA between baseline and W48 was -0.13 log(10 copies/10(6 PBMC (IQR = -0.34 to +0.10, mainly explained by the evolution from W0 to W4. No more changes were observed in the W4-W48 period. CONCLUSIONS: In highly-experienced multidrug-resistant patients, HIV-1 DNA slightly decreased during the first month and then remained stable during the first year of highly potent antiretroviral regimen. In this population, baseline HIV-1 DNA might help to better predict the virological response and to tailor clinical therapeutic management as more aggressive therapeutic choices in patients with higher baseline HIV-1 DNA.

  10. Novel high-pressure structures of MgCO3, CaCO3 and CO2 and their role in Earth's lower mantle

    Oganov, Artem R.; Ono, Shigeaki; Ma, Yanming; Glass, Colin W.; Garcia, Alberto


    Most of the oxidized carbon in the Earth's lower mantle is believed to be stored in the high-pressure forms of MgCO3 and/or CaCO3 or possibly even CO2. Recently, through ab initio evolutionary simulations and high-pressure experiments, a complete picture of phase transformations of CaCO3 at mantle pressures was obtained. Here, using the same approach, we investigate the high-pressure structures of MgCO3. Two new structure types were predicted to be stable in the relevant pressure range: one at 82-138 GPa and the other above 138 GPa. Both phases contain rings of corner-sharing CO4-tetrahedra. These predictions were largely confirmed by the experiments presented here. A number of structurally very different, but energetically competitive metastable polymorphs were found and reveal complex high-pressure chemistry of MgCO3, in contrast to CaCO3. For CO2, from 19 GPa to at least 150 GPa, we find β-cristobalite structure to be stable. Differences between high-pressure tetrahedral carbonates and low-pressure silicates are discussed in terms of rigidity of the T-O-T angles (flexible when T = Si and stiff when T = C). We show that through most of the P-T conditions of the mantle, MgCO3 is the major host of oxidized carbon in the Earth. We discuss the possibility of CO2 release at the very bottom of the mantle, which could enhance partial melting of rocks and explain the geodynamical differences between the Earth and Venus.

  11. Room Temperature Ammonia Gas Sensing Characteristics of Co3O4

    P.N. Shelke


    Full Text Available Room temperature ammonia gas-sensing characteristics of Co3O4 pellet sensor are reported in this paper. For this purpose, Co3O4 powder is prepared by a route of simple precipitation + heating at 800 °C/2 hr. The as-prepared powder is characterized by using X-ray diffraction and scanning electron microscopy. The ammonia gas-sensing properties of Co3O4 pellets made at various loads of 3, 5, 7 & 9 ton and at constant time = 4 min. are measured using home-built static gas sensing system. The characterization studies revealed that the cobalt oxide particles formed are cubic spinel Co3O4, highly pure and spherical in shape. The particle size distribution is found to be nearly uniform with average particle size ~ 1 µm. The ammonia gas sensing properties of Co3O4 pellet sensor are found to be good. The highest sensitivities – S.F. = 175 and 358 are found at ~ 25 ppm and 250 ppm concentrations of ammonia gas respectively for the Co3O4 pellet sensor made at the load = 3 ton. Further, an admirable repeatability and reversibility in the ammonia gas sensing characteristics are observed for all the Co3O4 pellet sensors. The average response time of 4.0 min. and recovery time of 3.0 min. are obtained for all the Co3O4 pellet sensors.

  12. Synthesis of Co/Co3O4 Nanocomposite Particles Relevant to Magnetic Field Processing

    Srivastava, A.K.; Madhavi, S.; Menon, Mohan;


    Co/Co3O4 nanocomposite particles of various morphologies were synthesized by the reverse micelle technique. Equiaxed, rod and faceted crystals with rectangular, pentagonal and hexagonal cross sections were observed. Annealing resulted in the formation of a composite of cobalt oxide (Co3O4) and fcc...

  13. Preparation, characterization, viscosity and thermal conductivity of CaCO3 aqueous nanofluids


    CaCO3 aqueous nanofluids were prepared by dispensing aqueous CaCO3 paste into distilled water under ultrasonic vibration. The actual microstructures of the CaCO3 nanofluids with different particle volume fractions were characterized by freeze etching replication transmission electron microscopy (FERTEM). Thermal conductivity and rheological behavior of the nanofluids were measured by standard analyzers. The results show that CaCO3 paste as raw material for nanofluids is advantageous to reducing aggregation of primary nanoparticles. The effective viscosities and effective thermal conductivities of the CaCO3 nanofluids are related to the aggregates of nanoparticles and can be well predicted by the modified Krieger & Dougherty formula and the modified Hamilton & Crosser model, respectively.

  14. Crystal structure and magnetic properties of ultrafine nanocrystalline SmCo3 compound

    The single-phase ultrafine nanocrystalline SmCo3 compound with a high coercivity of 33 kOe and a Curie temperature of 925 K was prepared using a simple and efficient method, which took advantages of the concurrent processes of nanocrystallization and densification during spark plasma sintering. The crystal structure of the nanocrystalline SmCo3 compound was constructed. As compared with the conventional microcrystalline SmCo3 compound, a large axial ratio c/a = 4.920 and an expansion of the unit cell volume of 2.97% were obtained in the lattice structure of the nanocrystalline SmCo3. The relationship between the magnetic properties and the nanocrystalline structure was analyzed. A specific magnetic transition from the weak ferromagnetic to the strong ferromagnetic state was discovered in the nanocrystalline SmCo3 compound, which was considered to be related to the large anisotropic strain in the crystal lattice.

  15. Controlled precipitation of nesquehonite (MgCO 3·3H 2O) by the reaction of MgCl 2 with (NH 4) 2CO 3

    Wang, Yong; Li, Zhibao; Demopoulos, George P.


    In this study, homogeneous (unseeded) precipitation of nesquehonite (MgCO 3·3H 2O) by the reaction of MgCl 2 with (NH 4) 2CO 3 in supersaturated solutions was investigated. Factors that influence the precipitation of MgCO 3·3H 2O, such as reaction temperature, initial concentration, stirring speed, titration speed, equilibration time, have been studied. SEM images and particle size distribution show that the temperature, initial concentration and titration speed have significant effect on nesquehonite's crystal morphology and particle size. In addition, stirring speed and equilibration time also have some influence on its properties. X-ray powder diffraction (XRD) results show that the obtained crystals compositions are greatly affected by the reaction temperature. With the morphological transformation, their corresponding composition also change from MgCO 3· xH 2O to Mg 5(CO 3) 4(OH) 2·4H 2O in the interval of 288-333 K. With the optimization of operating conditions, the crystals can grow up to a length of about 40 μm and a width of 5 μm, indicating good filtration properties. High-purity nesquehonite obtained in this study was calcined to produce highly pure MgO at 1073 K as shown by XRD results.

  16. Co3O4 nanowires as high capacity anode materials for lithium ion batteries

    Highlights: ► The Co3O4 nanowires are synthesized from decomposition of CoC2O4·2H2O nanowires. ► The synthesis procedure shows us a facile and highly productive strategy. ► The Co3O4 nanowires are suitable as a promising anode material for LIBs. ► High capacity and good cycling stability are achieved for the Co3O4 nanowires. - Abstract: Co3O4 nanowires were synthesized from the decomposition of CoC2O4·2H2O nanowires which were obtained through a polyvinyl alcohol (PVA)-assisted solution-based precipitation process. And the formation mechanism of CoC2O4·2H2O nanowires was discussed. The Co3O4 nanowires had diameters in the range of 30–60 nm and lengths of several micrometers, inheriting the morphology of the CoC2O4·2H2O nanowires. The Co3O4 nanowires as an anode material in lithium-ion batteries exhibited a stable specific discharge/charge capacity of 611 mAh/g and 598 mAh/g after fifty cycles at a current density of 0.11 A/g, which were much higher than that of commercial Co3O4 nanoparticles. In addition, the charge capacity of the as-synthesized Co3O4 nanowires was more than two times higher than that of the commercial Co3O4 nanoparticles at a current density of 1.1 A/g. These results indicate that the as-prepared Co3O4 nanowires have potential to be a promising candidate as high capacity anode material in the next generation lithium-ion batteries.

  17. CaCO3的表面改性对PP/CaCO3复合材料性能的影响%Effect of Surface Modification of CaCO3 on Mechanical Properties of PP/CaCO3 Composite

    永山; 聪士; 于建; 西 敏夫



  18. Surface modification of CaCO3 filler and its characterization using inverse gas chromatography (IGC)

    Guangcheng ZHANG; Xuetao SHI; Yajuan XING; Ting CHEN


    A CaCO3 filler was treated by generally used coupling agents and a special one-ethylene-octene copolymer (POE)-g-maleic anhydride (MAH). Fourier transform infrared spectroscopy (FTIR) results show that the special coupling agent POE-g-MAH, in a chemical reaction with CaCO3, can produce an interfacial layer stronger than simple physical adhesion attained with usual coupling agents. Inverse gas chromatography (IGC) was used to investigate the surface free energy of CaCO3 after surface modification and to optimize the monolayer content of coupling agents. Based on the IGC results, it can be deduced that the monolayer cover is around 1.9% for CaCO3 treated with a titanate coupling agent. Scanning electron microscope (SEM) observation results show that the separated morphology existed in the ternary composites containing CaCO3 after surface treatment with coupling agents, whereas the core-shell morphology was obtained in the ternary composites with POE-g-MAH. The encapsulation of the CaCO3 filler treated with POE-g-MAH was caused by the strong chemical reaction between the elastomer and CaCO3 particles.

  19. Enhanced biohydrogen production from sugarcane bagasse by Clostridium thermocellum supplemented with CaCO3.

    Tian, Qing-Qing; Liang, Lei; Zhu, Ming-Jun


    Clostridium thermocellum ATCC 27405 was used to degrade sugarcane bagasse (SCB) directly for hydrogen production, which was significantly enhanced by supplementing medium with CaCO3. The effect of CaCO3 concentration on the hydrogen production was investigated. The hydrogen production was significantly enhanced with the CaCO3 concentration increased from 10mM to 20mM. However, with the CaCO3 concentration further increased from 20mM to 100mM, the hydrogen production didn't increase further. Under the optimal CaCO3 concentration of 20mM, the hydrogen production reached 97.83±5.19mmol/L from 2% sodium hydroxide-pretreated SCB, a 116.72% increase over the control (45.14±1.03mmol/L), and the yield of hydrogen production reached 4.89mmol H2/g SCBadded. Additionally, CaCO3 promoted the biodegradation of SCB and the growth of C. thermocellum. The stimulatory effects of CaCO3 on biohydrogen production are mainly attributed to the buffering capacity of carbonate. The study provides a novel strategy to enhance biohydrogen production from lignocellulose. PMID:26356113

  20. Structural, morphological, optical and magnetic properties of Co3O4 nanoparticles prepared by conventional method

    Gopinath, S.; Sivakumar, K.; Karthikeyen, B.; Ragupathi, C.; Sundaram, R.


    Cobalt oxide (Co3O4) is one of the favorable nanoparticles (NPs) that possesses many remarkable properties so that it can be used in medicine, chemistry, environment, energy, information, industry, and so on. In this study, the crystalline Co3O4 nanoparticles (NPs) were successfully prepared by an efficient conventional method technique from an using different fuels. In the present paper, pure phase and well-dispersed Co3O4 were synthesized via the starch and aqueous ammonia solution in the stoichiometric fuel compositions. The structure and morphology of by way of organized Co3O4 nanoparticles were characterized by the structural analysis, electron microscopy studies, and optical properties studies. Magnetic properties exposed that the Co3O4 nanoparticles had ferromagnetic performance at room temperature with saturation magnetization of 71.09 emu/g. The results revealed that the changing the precursor led to great effects on the crystal size, emission peaks, and the reaction time of preparing the Co3O4 NPs. The significant feature of this manuscript is that the effects of different precursors on the structural magnetic and optical properties of Co3O4 NPs were investigated for the first time. The average particle size of samples (A and B) 23.6 and 22.2 nm, respectively.

  1. In situ biosynthesis of bacterial nanocellulose-CaCO3 hybrid bionanocomposite: One-step process.

    Mohammadkazemi, Faranak; Faria, Marisa; Cordeiro, Nereida


    In this work, a simple and green route to the synthesis of the bacterial nanocellulose-calcium carbonate (BNC/CaCO3) hybrid bionanocomposites using one-step in situ biosynthesis was studied. The CaCO3 was incorporated in the bacterial nanocellulose structure during the cellulose biosynthesis by Gluconacetobacter xylinus PTCC 1734 bacteria. Hestrin-Schramm (HS) and Zhou (Z) culture media were used to the hybrid bionanocomposites production and the effect of ethanol addition was investigated. Attenuated total reflection Fourier transform infrared spectroscopy, field emission scanning electron microscopy, X-ray diffraction, energy-dispersive X-ray spectroscopy, inverse gas chromatography and thermogravimetric analysis were used to characterize the samples. The experimental results demonstrated that the ethanol and culture medium play an important role in the BNC/CaCO3 hybrid bionanocomposites production, structure and properties. The BNC/CaCO3 biosynthesized in Z culture medium revealed higher O/C ratio and amphoteric surface character, which justify the highest CaCO3 content incorporation. The CaCO3 was incorporated into the cellulosic matrix decreasing the bacterial nanocellulose crystallinity. This work reveals the high potential of in situ biosynthesis of BNC/CaCO3 hybrid bionanocomposites and opens a new way to the high value-added applications of bacterial nanocellulose. PMID:27157766

  2. [Bmim][TfO] ionic liquid-assisted oriented growth of Co3O4 nanoworms

    Graphical abstract: Display Omitted Highlights: ► First time, we have used [Bmim][TfO]IL for the synthesis of Co3O4 nanoworms. ► IL assists to form oriented growth of cubic Co3O4 nanoworms without intermediate. ► Cubic Co3O4 nanoworms are in the range of 20 nm width and 100–200 nm length. ► IL and oxidizing agent have not altered the Co3O4 structural characteristics. ► Co3O4 nanoworms exhibit crystalline domain dependent weak ferromagnetism. -- Abstract: Monodispersed worm-like structure of Co3O4 nanocrystals of 20 nm width and 100–200 nm length are prepared directly without any intermediate product by 1-n-butyl-3-methylimidazolium trifluoromethane sulfonate ionic liquid ([Bmim][TfO] IL) assisted precipitation method. The higher concentration of [Bmim][TfO] IL in the reaction medium leads to the formation of homogeneous nanoworms. The effect of synthesis temperature and the oxidizing agent (H2O2) on the Co3O4 particle's morphology and their magnetic properties are discussed. Thermogravimetric analysis (TGA), powder X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), field emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM) analysis were used to characterize the Co3O4 monodispersed nanoworms. The magnetic property of the spinel Co3O4 nanoworms is highly dependent on crystalline domains and exhibits weak ferromagnetic behavior with a narrow hysteresis loop opening.

  3. Catalytic properties of Co3O4 nanoparticles for rechargeable Li/air batteries

    Kim, Kwan Su; Park, Yong Joon


    Three types of Co3O4 nanoparticles are synthesized and characterized as a catalyst for the air electrode of a Li/air battery. The shape and size of the nanoparticles are observed using scanning electron microscopy and transmission electron microscopy analyses. The formation of the Co3O4 phase is confirmed by X-ray diffraction. The electrochemical property of the air electrodes containing Co3O4 nanoparticles is significantly associated with the shape and size of the nanoparticles. It appears t...

  4. Grain refinement of AZ91D magnesium alloy by MgCO3

    Ti Jun Chen; Xiang Dong Jiang; Ying Ma; Rui Quan Wang; Yuan Hao


    The grain refining technique of AZ91D magnesium alloy by MgCO3 has been investigated. The refining mechanism and tensile properties of the resulting alloy have also been discussed. The results indicate that MgCO3 can decrease its grain size from 311 to 53µm. Correspondingly, the tensile properties are obviously improved. The higher the cooling rate from addition temperature to pouring temperature or the higher the addition temperature, the finer the grains. The melt treated by MgCO3 should be...

  5. Electrical transport and thermochromic properties of polyaniline/chitosan/Co3O4 ternary nano composite

    V, Mini; Kamath, Archana; S, Raghu; Chapi, Sharanappa; H, Devendrappa


    A new Polyaniline/ chitosan/ Co3O4 (CPAESCO) ternary nanocomposite is prepared by in situ oxidation polymerization of aniline in the presence of (NH4)2S2O8, chitosan and Co3O4. The Structural, Thermal, Optical and Electrical features of Polyaniline (PANI), Polyaniline/ chitosan (CPANI) and CPAESCO were analyzed using FT-IR, TGA, UV-vis analysis and Impedance spectroscopy by varying temperature. The results show that the introduction of the Co3O4 nanoparticles into CPANI matrix enhanced its properties. Mott's parameters show 3D -VRH Type conduction in it.

  6. First-principles calculations of structural, electronic, optical and elastic properties of magnesite MgCO 3 and calcite CaCO 3

    Brik, M. G.


    Detailed ab initio calculations of the structural, electronic, optical and elastic properties of two crystals - magnesite (MgCO 3) and calcite (CaCO 3) - are reported in the present paper. Both compounds are important natural minerals, playing an important role in the carbon dioxide cycling. The optimized crystal structures, band gaps, density of states diagrams, elastic constants, optical absorption spectra and refractive indexes dependence on the wavelength all have been calculated and compared, when available, with literature data. Both crystals are indirect band compounds, with calculated band gaps of 5.08 eV for MgCO 3 and 5.023 eV for CaCO 3. Both values are underestimated by approximately 1.0 eV with respect to the experimental data. Although both crystals have the same structure, substitution of Mg by Ca ions leads to certain differences, which manifest themselves in noticeable change in the electronic bands profiles and widths, shape of the calculated absorption spectra, and values of the elastic constants. Response of both crystals to the applied hydrostatic pressure was analyzed in the pressure range of phase stability, variations of the lattice parameters and characteristic interionic distances were considered. The obtained dependencies of lattice constants and calculated band gap on pressure can be used for prediction of properties of these two hosts at elevated pressures that occur in the Earth's mantle.

  7. PP/纳米CaCO3分散体系的研究%Study of Dispersants for PP/nano-CaCO3 Blend

    李远; 陈建国; 陈腊琼; 王正东


    本文研究了不同的分散剂对PP/纳米CaCO3体系的分散效果,以及加工工艺条件对该体系的影响。结果表明:超分散剂CH-1A对纳米CaCO3有显著的分散作用,使体系的冲击强度有了大幅度提高。在使PP完全塑化的前提下,超分散剂CH-1A使纳米CaCO3在PP中随转速的提高其分散效果也提高,使体系具有较好的加工性能。%Dispering effects of three different kinds of dispersants on PP/nano-CaCO3 system and influences of processing parameters on it were studied,the results showed that hyper-dispersant CH-1A had the most excellent dispering effect on nonao-calcium carbonate in PP and made the impact strength of the system markedly improved.The dispering effect of hyper-dispersant CH-1A became better with the increase of rolling speed if PP was wholly plasticized and made the system have a better processing properties.

  8. Thermal behavior of SrSO4-SrCO3 and SrSO4-SrCO3-Al2O3 mixtures

    The high temperature behavior of SrSO4, SrCO3 and Al2O3 mixtures was studied. A mixture of 1:1 mole of SrSO4 and mechanically activated SrCO3 was mixed and characterized using thermal gravimetric analysis. Some samples were uniaxially pressed and sintered at 1100, 1200 and 1300 deg. C for 8 h and then analyzed using X-ray diffraction and scanning electron microscopy. Additionally, a mixture of SrSO4:SrCO3:Al2O3 was uniaxially pressed and sintered at 1500 deg. C. The decomposition temperature of SrCO3 was decreased 18 deg. by milling for 180 min. Samples sintered at 1300 deg. C showed a microstructure free of porosity. X-ray diffraction analysis showed the presence of SrO and SrSO4 after sintering at 1100, 1200 and 1300 deg. C. The mixture containing alumina showed the formation of a strontium aluminum oxide sulfate compound in addition to strontium aluminate

  9. 红掌ANR基因克隆及其表达与佛焰苞颜色的相关性分析%Cloning of ANR Gene from Anthurium and Relativity Analysis of Its Expression with the Spath Color

    李雪; 李志英; 丛汉卿; 徐立


    Anthocyanidin is an important content for plant color appearence. Caltivars of A nthurium andraeanum display varies spathe colors have different concentrations of anthocyanidin. In anthocyanin biosynthetic pathway, Anthocyanidin Reductase (ANR) is a key enzyme to catalyze anthocyanidins to proanthocyanidin (PC). In order to verify the regulation of ANR in anthocyanin synthesis, we cloned the whole cDNA sequence of ANR by RACE technology according to the known ANR fragment from SSH library. BLAST results showed that A nA NR had high similarity, 72%~75%, with reported ANR gene from Populus trichocarpa, Camellia sinensis and V itis vinifera. RT-PCR results showed that in anthurium cultivars with different spathe colors, the expression level of A nA NR was negatively related with the accumulation of anthocyanidin.%花青素是植物颜色形成的重要成分之一。不同红掌品种中的花青素含量与佛焰苞颜色密切相关。花青素还原酶(ANR)是植物花青素调控代谢途径中催化产生原花青素的一个重要基因。为了探明ANR对花青素合成的作用,本研究根据从抑制差减文库中获得的基因片段,采用RACE技术克隆红掌ANR基因cDNA全长序列。BLAST结果显示,红掌ANR基因全长核苷酸序列与已报道的植物(葡萄,茶树,毛果杨等)同源性为72%~75%,氨基酸序列的同源性则达到78%~79%。RT-PCR结果表明ANR在不同颜色的红掌佛焰苞中表达有差异,其表达量与花青素含量成负相关。

  10. Mechano-activated preparation of CaCO3/RCOO- compound material and its characterization ( Ⅱ )-the action mechanism of RCOO- and CaCO3%CaCO3/RCOO-复合材料的制备与性能研究(Ⅱ)——RCOO-与CaCO3表面作用机理




  11. 'Scorpion-like' dithiocarbamato-carboxylate ligands for linking M(CO)3+ (M = Tc, Re)

    Complexation of M(CO)3+ (M = Tc, Re) with dithiocarbamato-carboxylate ligands was studied. It was found that the dithiocarbamate chelation unit has rather high affinity to M(CO)3+ species and the resulting complexes are extremely stable in a wide pH range. The complex M(CO)3[S2CN(CH2COO)2] is monomeric in solution (ESI MS) and dimeric in the crystal phase (single-crystal XRD). The 'scorpion-like' dithiocarbamato-carboxylate ligands were prepared; it was shown that C5 chain is long enough to reach back to the free coordination vacancy in M(CO)3+ core and to block it. (author)

  12. Structural, electrical and optical properties of Co3O4 nanoparticles

    Makhlouf, Salah A.; Bakr, Zinab H.; Aly, Kamal I.; Moustafa, M. S.


    Co3O4 nanoparticles were prepared by chemical precipitation followed by heat treatment at different temperatures. The structure and morphology of Co3O4 nanoparticles were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, Transmission electron microscopy and the N2 adsorption-desorption techniques. The results indicate the formation of a single crystalline Co3O4 phase with a high surface area, mesoporous structure and particles size that depends on the calcination temperature. DC electrical conductivity was investigated in the temperature range 160-470 K. Variation of the electrical conductivity with temperature reveals double-valued activation energy, and the data was discussed in view of the structural and morphological properties. The temperature dependence of the AC conductivity and dielectric constant was also investigated in the same temperature range. In addition, analysis of the optical properties indicates a red shift of the absorption peaks relative to bulk Co3O4.

  13. Preparation and electrochemical capacitance of cobalt oxide (Co3O4) nanotubes as supercapacitor material

    Cobalt oxide (Co3O4) nanotubes have been successfully synthesized by chemically depositing cobalt hydroxide in anodic aluminum oxide (AAO) templates and thermally annealing at 500 oC. The synthesized nanotubes have been characterized by scanning electron microscope (SEM), transmission electron microscope (TEM) and X-ray diffraction (XRD). The electrochemical capacitance behavior of the Co3O4 nanotubes electrode was investigated by cyclic voltammetry, galvanostatic charge-discharge studies and electrochemical impedance spectroscopy in 6 mol L-1 KOH solution. The electrochemical data demonstrate that the Co3O4 nanotubes display good capacitive behavior with a specific capacitance of 574 F g-1 at a current density of 0.1 A g-1 and a good specific capacitance retention of ca. 95% after 1000 continuous charge-discharge cycles, indicating that the Co3O4 nanotubes can be promising electroactive materials for supercapacitor.

  14. Synthesis of Co3S4 Nanosheets and Their Superior Supercapacitor Property

    Xu, Bo; Pan, Lu; Zhu, Qiyong


    Sheet-like Co3S4 nanomaterial with high purity was synthesized via a facile and easily controlled one-step hydrothermal route. The structure and morphology of the as-synthesized sample was characterized by x-ray diffraction, transmission electron microscopy, and field emission scanning electron microscopy, respectively. The Co3S4 nanosheets with a mean size of 10 nm or so were used as electrode material and the supercapacitor property was determined. The results show that the specific capacitance of the Co3S4 nanosheets reaches 1037 F/g at 1 A/g. After 3000 charge-discharge recycles, the remained specific capacitance of the supercapacitor is 978 F/g, which is 94.3% of its initial value. The experiments indicate that the Co3S4 supercapacitor possesses high specific capacitance and excellent cyclic stability, which suggests its potential application in supercapacitor.

  15. Controllable synthesis of self-assembly Co3O4 nanoflake microspheres for electrochemical performance

    Liu, Fangyan; Zhang, Binbin; Su, Hai; Zhang, Haitao; Zhang, Lei; Yang, Weiqing


    Tuning the ratios of ethanol to water, self-assembling microspheres composed of Co3O4 nanoflakes are synthesized by the hydrothermal method. The scanning electron microscopy (SEM) images of as-grown samples obviously show that the dispersive multilayered structures gradually change into micro/nanobelts and cubic blocks structures, and then into the desired self-assembled microspheres with increasing ratios of ethanol to water. Also, all the x-ray diffraction (XRD) patterns evidently demonstrate that all obtained Co3O4 has cubic crystal structure. The corresponding synthesis mechanism is discussed in detail. More importantly, the unique self-assembling Co3O4 nanoflake microspheres have excellent electrochemical performance with large specific capacitance, good rate capability and excellent cycling performance, evidently presenting a potential capability of Co3O4 nanoflake microspheres to act as electrode materials for supercapacitors in sustainable power sources.

  16. Non-enzymatic hydrogen peroxide sensor based on Co3O4 nanocubes

    Guang Sheng Cao; Lei Wang; Pengfei Yuan; Chao Gao; Xiaojuan Liu; Tong Li; Tianmin Li


    The Co3O4 nanocubes were prepared by using hydrogen peroxide (H2O2) as oxidant, Co(NO3)2. 6H2O as a cobalt source. The products were characterized in detail by multiform techniques: scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffraction (XRD). The prepared Co3O4 nanocubes were applied to study the electrocatalytic reduction of hydrogen peroxide (H2O2) in 0.01 M pH 7.0 phosphate buffer medium. The Co3O4 nanocubes exhibit remarkable electrocatalytic activity for H2O2 reduction. Furthermore, the obtained Co3O4 nanocubes have been employed as electrode materials for electrochemical sensing H2O2.

  17. Ultrasound-assisted green synthesis of nanocrystalline Co3O4 in the ionic liquid

    Cobalt oxide Co3O4 nanoparticles have been synthesized via sonochemical method in an ionic liquid, 1-Ethyl-3-methylimidazolium tetrafluoroborate [EMIM][BF4] for the first time. The crystal structure of Co3O4 nanoparticles has been characterized by using powder X-ray diffraction (XRD). Morphology has been characterized by transmission electron microscopy (TEM). The optical properties were studied by UV-VIS Spectrometer

  18. Low-temperature Growth of Single-crystal SrCO3 Nanoneedles

    Guang Sheng GUO; Fu Bo GU; Zhi Hua WANG; Hong You GUO


    Single-crystal SrCO3 nanoneedles were synthesized in reverse micelles at low temperature. The products were characterized by X-ray diffraction, X-ray energy dispersive spectrometer, transmission electron microscopy and selected area electronic diffraction. The influences of experimental conditions on the morphologies of the products were discussed. The growth mechanism of SrCO3 nanoneedles in reverse micelles were proposed.

  19. Three-dimensional porous graphene-Co3O4 nanocomposites for high performance photocatalysts

    Bin, Zeng; Hui, Long


    Novel three-dimensional porous graphene-Co3O4 nanocomposites were synthesized by freeze-drying methods. Scanning and transmission electron microscopy revealed that the graphene formed a three-dimensional porous structure with Co3O4 nanoparticles decorated surfaces. The as-obtained product showed high photocatalytic efficiency and could be easily separated from the reaction medium by magnetic decantation. This nanocomposite may be expected to have potential in water purification applications.

  20. Co3O4 Nanocrystals on Graphene as a Synergistic Catalyst for Oxygen Reduction Reaction

    Liang, Yongye; Li, Yanguang (Charles); Wang, Hailiang; Zhou, Jigang; Wang, Jian; Regier, Tom; Dai, Hongjie


    Catalysts for oxygen reduction and evolution reactions are at the heart of key renewable energy technologies including fuel cells and water splitting. Despite tremendous efforts, developing oxygen electrode catalysts with high activity at low costs remains a grand challenge. Here, we report a hybrid material of Co3O4 nanocrystals grown on reduced graphene oxide (GO) as a high-performance bi-functional catalyst for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). While Co3O...

  1. Preparation, electronic structure, and photocatalytic properties of Bi2O2CO3 nanosheet

    Bi2O2CO3 nanosheet with a thickness of less than 20 nm was synthesized via hydrothermal and solvothermal process. The properties of the as-prepared nanosheet were characterized by X-ray diffraction, scanning electron microscopy, and diffuse reflectance spectra. The electronic structure was investigated using first-principle calculations. Application of the as-prepared Bi2O2CO3 nanosheet in photocatalysis was also studied.

  2. PE/CaCO3-nanocomposites synthesized by in-situ polymerization



    Polyethylene-nanocomposites with CaCO3-weight fractions from 0 to 15 wt.% were prepared by in-situ polymerization with Me2Si(Ind)2ZrCl2/MAO metallocene catalysts. A high activity especially in the presence of TIBA was observed. The morphology was investigated by using raster electron microscopy (REM) showing that the CaCO3-nanoparticles are uniformly distributed. The melting temperatures and the crystallization temperatures are not much influenced by increasing filler content.

  3. Synthesis of Co/Co3O4 nanocomposite particles relevant to magnetic field processing.

    Srivastava, A K; Madhavi, S; Menon, M; Ramanujan, R V


    Co/Co3O4 nanocomposite particles of various morphologies were synthesized by the reverse micelle technique. Equiaxed, rod and faceted crystals with rectangular, pentagonal and hexagonal cross sections were observed. Annealing resulted in the formation of a composite of cobalt oxide (Co3O4) and fcc cobalt (Co). Removal of boron residues from the final product was established by surface characterization. Magnetic moment of these nanocomposite particles is relevant to magnetic field processing. PMID:21137765

  4. Nano—CaCO3改性聚烯烃树脂研究进展%Research of Progress on Modifications of Nano-- CaCO3/polyolefin Composites

    姜鹏; 韩亚魁; 程泰山; 冼以积; 曹新鑫


    介绍了nano—CaCO3改性聚丙烯、聚乙烯、聚氯乙烯、苯乙烯和ABS等树脂的力学性能、结晶行为和老化行为等性能的研究进展。并对nano—CaCO3的改性应用和研究方向做了展望。%The modifications of nano-- CaCO3/PP, nano-- CaCO3/PE, nano-- CaCO3 / PVC, nano--CaCO3/PS and nano--CaCO3/ABS as well as the nanocomposites" me- chanical properties, crystallization behavior and ageing behavior were reviewed in this paper. Furthermore, the modified application and research direction of nano--CaCO3 were also prospected.

  5. Fe2O3/ Co3O4 composite nanoparticle ethanol sensor

    Mirzaei, Ali; Sun, Gun-Joo; Kheel, Hyejoon; Lee, Sangmin; lee, Chongmu


    In this study Fe2O3/Co3O4 nanocomposites were synthesized by using a simple hydrothermal route. The X-ray diffraction analysis results showed that synthesized powders were pure, and nanocrystalline in nature. Moreover, Scanning electron microscopy revealed that Fe2O3 nanoparticles had spherical shapes while Co3O4 particles had a rod-like morphology. Ethanol sensing properties of Fe2O3/Co3O4 nanocomposites were examined and compared with those of pristine Fe2O3 nanoparticles. It was shown that the gas sensing properties of Fe2O3/Co3O4 nanocomposites were superior to those of pristine Fe2O3 nanoparticles and for all concentrations of ethanol, the response of the nanocomposite sensor was higher than the pristine Fe2O3 nanoparticle sensor. In detail, the response of Fe2O3/Co3O4 nanocomposite sensor to 200 ppm of ethanol at 300{\\deg}C was about 3 times higher than pristine one. Also in general, the response and recovery times of Fe2O3/Co3O4 nanocomposite sensor were shorter than those of the pristine one. The impr...

  6. Study of antibacterial activity of Ag and Ag2CO3 nanoparticles stabilized over montmorillonite

    Sohrabnezhad, Sh.; Pourahmad, A.; Mehdipour Moghaddam, M. J.; Sadeghi, A.


    Silver carbonate and silver nanoparticles (NPs) over of stabilizer montmorillonite (MMT) have been synthesized in aqueous and polyol solvent, respectively. Dispersions of silver nanoparticles have been prepared by the reduction of silver nitrate over of MMT in presence and absence of Na2CO3 compound in ethylene glycol. It was observed that montmorillonite was capable of stabilizing formed Ag nanoparticles through the reduction of Ag+ ions in ethylene glycol. Na2CO3 was used as carbonate source in synthesis of Ag2CO3 NPs in water solvent and also for controlling of Ag nanoparticles size in ethylene glycol medium. The samples were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), and ultraviolet-visible diffuse reflectance spectroscopy (DRS). The TEM images showed that Ag NPs size in presence Na2CO3 salts was smaller than without that. The results indicated intercalation of Ag and Ag2CO3 nanoparticles into the montmorillonite clay layers. The diffuse reflectance spectra exhibited a strong surface plasmon resonance (SPR) adsorption peak in the visible region, resulting from Ag nanoparticles. The antibacterial testing results showed that the Ag2CO3-MMT nanocomposite exhibited an antibacterial activity higher than Ag-MMT sample against Escherichia coli.

  7. Influence of CaCO3 Whisker Content on Mechanical and Tribological Properties of Polyetheretherketone Composites

    Youxi LIN; Chenghui GAO; Ning LI


    The mechanical and tribological properties of polyetheretherketone(PEEK)composites filled with CaCO3 whisker in various content of 0~45%(wt pct)were investigated. The composite specimens were prepared by compression molding. Tribological testing of composites in dry wear mode against carbon steel ring was carried out on a MM200 block-on-ring apparatus. Data on neat PEEK were also included for comparison. It was observed that inclusion of CaCO3 whisker affected the most mechanical properties and the friction and wear in a beneficial way. With an increase in CaCO3 whisker content, friction coefficient continuously decreased but the trends in wear performance varied. The specific wear rate showed minima as 1.28×10-6 mm3/Nm for 15% CaCO3 whisker inclusion followed by a slow increase for further CaCO3 whisker addition. In terms of friction applications, when the tribological and mechanical properties are combined, the optimal content of CaCO3 whisker in the filled PEEK should be recommended as 15% to 20%. Fairly good correlations are observed in friction coefficient vs bending modulus and wear rate vs bending strength, confirming that the bending properties prove to be the most important tribology controlling parameters in the present work.

  8. Poly(3-hydroxybutyrate and Poly(3-hydroxybutyrate-co-3-hydroxyvalerate: Structure, Property, and Fiber

    Qingsheng Liu


    Full Text Available Poly(3-hydroxybutyrate [P(3HB] and poly(3-hydroxybutyrate-co-3-hydroxyvalerate [P(3HB-co-3HV] are produced by various microorganisms as an intracellular carbon and energy reserve from agricultural feedstocks such as sugars and plant oils under unbalanced growth conditions. P(3HB and P(3HB-co-3HV have attracted the attention of academia and industry because of its biodegradability, biocompatibility, thermoplasticity, and plastic-like properties. This review first introduced the isodimorphism, spherulites, and molecular interaction of P(3HB and P(3HB-co-3HV. In addition, the effects of 3HV content on the melting temperature and crystallization rate were discussed. Then the drawbacks of P(3HB and P(3HB-co-3HV including brittleness, narrow melt processing window, low crystallization rate, slow biodegradation rate in body, and so on were summarized. At last, the preparation, structure, and properties of P(3HB and P(3HB-co-3HV fiber were introduced.

  9. Influence of Surfactant-polymer Complexes on Crystallization and Aggregation of CaCO3

    PAN Yan; GUO Yu-peng; ZHAO Xu; WANG Zi-chen


    Hollow calcium carbonate(CaCO3) microspheres with different morphologies were synthesized via the precipitation reaction of calcium chloride with sodium carbonate in the presence of different surfactant-polymer complexes.The selected anionic surfactants were sodium dodecyl sulfonate(SDS) and sodium dodecyl benzenesulfonate(SDBS),respectively.The selected water-soluble polymers were polyacrylic acid(PAA) and polyvinyl pyrrolidone(PVP).In this work,SDS-PVP "pearl-necklace model" micellar complex was formed via hydrophobic effectiveness between SDS and PVP and it served as the spherical template to generate spherical CaCO3 aggregates with hollow microspheres composed of about 500 nm irregular shaped particles.SDS-PAA complexes and SDBS-PAA complexes formed "core-shell model" aggregates with calcium ions serving as the medium to link the anionic surfactant and the polymer.SDS-PAA "core-shell model" aggregates would act as templates for hollow CaCO3 microspheres consisting of 30-50 nm irregular shaped crystallites.SDBS-PAA "core-shell model" aggregates served as the spherical aggregate templates to generate spherical CaCO3 aggregates consisted of many small spherical particles which had grown together.All the obtained CaCO3 hollow microspheres are calcite particles.This research may provide new insight into the control of morphologies of hollow CaCO3 microspheres in the presence of surfactantpolymer complexes.

  10. Activity-composition relations in the system CaCO 3-MgCO 3 predicted from static structure energy calculations and Monte Carlo simulations

    Vinograd, Victor L.; Burton, Benjamin P.; Gale, Julian D.; Allan, Neil L.; Winkler, Björn


    Thermodynamic mixing properties and subsolidus phase relations of the rhombohedral carbonate system, (1 - x) · CaCO 3 - x · MgCO 3, were modelled in the temperature range of 623-2023 K with static structure energy calculations based on well-parameterised empirical interatomic potentials. Relaxed static structure energies of a large set of randomly varied structures in a 4 × 4 × 1 supercell of R3¯c calcite ( a = 19.952 Å, c = 17.061 Å) were calculated with the General Utility Lattice Program (GULP). These energies were cluster expanded in a basis set of 12 pair-wise effective interactions. Temperature-dependent enthalpies of mixing were calculated by the Monte Carlo method. Free energies of mixing were obtained by thermodynamic integration of the Monte Carlo results. The calculated phase diagram is in good agreement with experimental phase boundaries.

  11. Insight into the Li2CO3-K2CO3 eutectic mixture from classical molecular dynamics: Thermodynamics, structure, and dynamics

    Corradini, Dario; Coudert, François-Xavier; Vuilleumier, Rodolphe


    We use molecular dynamics simulations to study the thermodynamics, structure, and dynamics of the Li2CO3-K2CO3 (62:38 mol. %) eutectic mixture. We present a new classical non-polarizable force field for this molten salt mixture, optimized using experimental and first principles molecular dynamics simulations data as reference. This simple force field allows efficient molecular simulations of phenomena at long time scales. We use this optimized force field to describe the behavior of the eutectic mixture in the 900-1100 K temperature range, at pressures between 0 and 5 GPa. After studying the equation of state in these thermodynamic conditions, we present molecular insight into the structure and dynamics of the melt. In particular, we present an analysis of the temperature and pressure dependence of the eutectic mixture's self-diffusion coefficients, viscosity, and ionic conductivity.

  12. Plasma-Engraved Co3 O4 Nanosheets with Oxygen Vacancies and High Surface Area for the Oxygen Evolution Reaction.

    Xu, Lei; Jiang, Qianqian; Xiao, Zhaohui; Li, Xingyue; Huo, Jia; Wang, Shuangyin; Dai, Liming


    Co3 O4 , which is of mixed valences Co(2+) and Co(3+) , has been extensively investigated as an efficient electrocatalyst for the oxygen evolution reaction (OER). The proper control of Co(2+) /Co(3+) ratio in Co3 O4 could lead to modifications on its electronic and thus catalytic properties. Herein, we designed an efficient Co3 O4 -based OER electrocatalyst by a plasma-engraving strategy, which not only produced higher surface area, but also generated oxygen vacancies on Co3 O4 surface with more Co(2+) formed. The increased surface area ensures the Co3 O4 has more sites for OER, and generated oxygen vacancies on Co3 O4 surface improve the electronic conductivity and create more active defects for OER. Compared to pristine Co3 O4 , the engraved Co3 O4 exhibits a much higher current density and a lower onset potential. The specific activity of the plasma-engraved Co3 O4 nanosheets (0.055 mA cm(-2) BET at 1.6 V) is 10 times higher than that of pristine Co3 O4 , which is contributed by the surface oxygen vacancies. PMID:26990905

  13. Sensitivity of pelagic CaCO3 dissolution to ocean acidification in an ocean biogeochemical model

    A. Regenberg


    Full Text Available In ocean biogeochemical models pelagic CaCO3 dissolution is usually calculated as R = k * Sn, where k is the dissolution rate constant transforming S, the degree of (under- saturation of seawater with respect to CaCO3, into a time dependent rate R, and n is the reaction rate order. Generally, there are two ways to define the saturation state of seawater with respect to CaCO3: (1 Δ[CO32−], which reflects the difference between the in-situ carbonate ion concentration and the saturation concentration, and (2 Ω, which is approximated by the ratio of in-situ carbonate ion concentration over the saturation concentration. Although describing the same phenomenon, the deviation from equilibrium, both expressions are not equally applicable for the calculation of CaCO3 dissolution in the ocean across pressure gradients, as they differ in their sensitivity to ocean acidification (change of [CO32−] over depth. In the present study we use a marine biogeochemical model to test the sensitivity of pelagic CaCO3 dissolution to ocean acidification (1–4 × CO2 + stabilization, exploring the possible parameter space for CaCO3 dissolution kinetics as given in the literature. We find that at the millennial time scale there is a wide range of CaCO3 particle flux attenuation into the ocean interior (e.g. a reduction of −55 to −85% at 1000 m depth, which means that there are significant differences in the impact on particle ballasting, depending on the kinetic expression applied.

  14. Co3O4/ZnO nanocomposites for gas-sensing applications

    Highlights: ► By a facile wet-chemistry route Co3O4/ZnO nanocomposites were successfully prepared. ► The ZnO is loaded on the surface of Co3O4 nanoparticles with compact hetero-interface. ► The obtained nanocomposites exhibit enhanced gas sensing properties with good stability and high sensing response. ► The excellent gas sensing properties and the easily scaled-up preparation route make the prepared nanocomposites promising for real application. - Abstract: Co3O4/ZnO nanocomposites were prepared by an easy wet-chemistry route without any organic additive or surfactant used. The nanocomposites were systematically characterized by X-ray powder diffraction, scanning electron microscopy, (high-resolution) transmission electron microscopy, selected area electron diffraction, and energy-dispersive X-ray spectroscopy. The results show that ZnO is loaded on the surface of Co3O4 nanoparticles with a compact and clean hetero-interface. The obtained nanocomposites were tested for gas-sensing applications with ethanol and formaldehyde as model gases. It was revealed that the nanocomposites exhibit enhanced gas-sensing performance such as high stability and high sensing response. The sensing responses to 100 ppm ethanol or formaldehyde (46 to ethanol and 20 to formaldehyde) are much higher than those of pristine Co3O4 nanoparticles (6.2 to ethanol and 4.4 to formaldehyde), commercial Co3O4 powder (1.6 to ethanol and 1.5 to formaldehyde), and pure ZnO sample (7.5 to ethanol and 4.1 to formaldehyde). These results suggest that the integration of Co3O4 with ZnO is a promising route to the development of effective sensing materials. The excellent gas-sensing properties and the easily up-scalable preparation route make the prepared nanocomposites be promising for real applications.

  15. Research and characterization of nano - CaCO3 dispersed in polystyrene%纳米CaCO3在PS中分散的表征和规律研究

    王旭; 濮阳楠; 黄锐; 任志军; 陈海涛



  16. Research on the formula of PVC door & window profiles containing nano-CaCO3%添加纳米CaCO3的PVC门窗异型材的配方研究

    杨秀岭; 苗乃芬; 韩正



  17. PVC/纳米CaCO3复合材料的制备与性能研究%Study on preparation and property of PVC/nano CaCO3 compound material

    应建波; 钟明强; 徐立新



  18. Investigation of miscibility of p(3hydroxybutyrate-co-3hydroxyhexanoate) and epoxidized natural rubber blends

    Akram, Faridah; Chan, Chin Han; Natarajan, Valliyappan David


    Poly(3-hydroxybutyrate-co-3-hydroxyhexanoate [P(3HB-co-3HHx)] produced by C. necator PHB-4 harboring phaCcs from crude palm kernel oil with 21 mol% of 3-hydroxyhexanoate and epoxidized natural rubber with 25 mol% of epoxy content (ENR-25) were used to study the miscibility of the blends by attenuated total reflection-Fourier transform infrared (ATR-FTIR) and differential scanning calorimetry (DSC). The polymers used were purified and the blends were prepared by solution casting method. Nuclear magnetic resonance (NMR) spectra confirm the purity and molecular structures of P(3HB-co-3HHx) and ENR-25. FTIR spectra for different compositions of P(3HB-co-3HHx) and ENR-25 blends show absorbance change of the absorbance bands but with no significant shifting of the absorbance bands as the P(3HB-co-3HHx) content decreases, which shows that there is no intermolecular interaction between the parent polymer blends. On top of that, there are two Tgs present for the blends and both remain constant for different compositions which corresponds to the Tgs of the parent polymers. This indicates that the blends are immiscible.

  19. Co3O4 based catalysts for NO oxidation and NOx reduction in fast SCR process

    Reaction activities of several developed catalysts for NO oxidation and NOx (NO + NO2) reduction have been determined in a fixed bed differential reactor. Among all the catalysts tested, Co3O4 based catalysts are the most active ones for both NO oxidation and NOx reduction reactions even at high space velocity (SV) and low temperature in the fast selective catalytic reduction (SCR) process. Over Co3O4 catalyst, the effects of calcination temperatures, SO2 concentration, optimum SV for 50% conversion of NO to NO2 were determined. Also, Co3O4 based catalysts (Co3O4-WO3) exhibit significantly higher conversion than all the developed DeNOx catalysts (supported/unsupported) having maximum conversion of NOx even at lower temperature and higher SV since the mixed oxide Co-W nanocomposite is formed. In case of the fast SCR, N2O formation over Co3O4-WO3 catalyst is far less than that over the other catalysts but the standard SCR produces high concentration of N2O over all the catalysts. The effect of SO2 concentration on NOx reduction is found to be almost negligible may be due to the presence of WO3 that resists SO2 oxidation. (author)

  20. Tuneable ultra high specific surface area Mg/Al-CO3 layered double hydroxides.

    Chen, Chunping; Wangriya, Aunchana; Buffet, Jean-Charles; O'Hare, Dermot


    We report the synthesis of tuneable ultra high specific surface area Aqueous Miscible Organic solvent-Layered Double Hydroxides (AMO-LDHs). We have investigated the effects of different solvent dispersion volumes, dispersion times and the number of re-dispersion cycles specific surface area of AMO-LDHs. In particular, the effects of acetone dispersion on two different morphology AMO-LDHs (Mg3Al-CO3 AMO-LDH flowers and Mg3Al-CO3 AMO-LDH plates) was investigated. It was found that the amount of acetone used in the dispersion step process can significantly affect the specific surface area of Mg3Al-CO3 AMO-LDH flowers while the dispersion time in acetone is critical factor to obtain high specific surface area Mg3Al-CO3 AMO-LDH plates. Optimisation of the acetone washing steps enables Mg3Al-CO3 AMO-LDH to have high specific surface area up to 365 m(2) g(-1) for LDH flowers and 263 m(2) g(-1) for LDH plates. In addition, spray drying was found to be an effective and practical drying method to increase the specific surface area by a factor of 1.75. Our findings now form the basis of an effective general strategy to obtain ultrahigh specific surface area LDHs. PMID:26308729

  1. Characterization of corn starch films reinforced with CaCO3 nanoparticles.

    Qingjie Sun

    Full Text Available The characterization of corn starch (CS films impregnated with CaCO3 nanoparticles was investigated. Criteria such as morphology, crystallinity, water vapor permeability (WVP, opacity, and mechanical properties were the focus of the investigation. It was found that the CaCO3 contents had significant effects on the tensile properties of the nanocomposite films. The addition of CaCO3 nanoparticles to the CS films significantly increased tensile strength from 1.40 to 2.24 MPa, elongation from 79.21 to 118.98%, and Young's modulus from 1.82 to 2.41 MPa. The incorporation of CaCO3 nanoparticles increased the opacity of films, lowered the degree of WVP and film solubility value compared to those of the CS films. The results of scanning electron microscopy (SEM showed that with the increase of CaCO3 nanoparticles content in starch films, the roughness of the films increased, and pores or cavities were found on the surface of the films, while small cracks were observed in the structures of the fractured surfaces. X-ray diffraction showed that the addition of nanoparticles increased the peaks in the intensity of films.

  2. Investigation of miscibility of p(3hydroxybutyrate-co-3hydroxyhexanoate) and epoxidized natural rubber blends

    Poly(3-hydroxybutyrate-co-3-hydroxyhexanoate [P(3HB-co-3HHx)] produced by C. necator PHB−4 harboring phaCcs from crude palm kernel oil with 21 mol% of 3-hydroxyhexanoate and epoxidized natural rubber with 25 mol% of epoxy content (ENR-25) were used to study the miscibility of the blends by attenuated total reflection-Fourier transform infrared (ATR-FTIR) and differential scanning calorimetry (DSC). The polymers used were purified and the blends were prepared by solution casting method. Nuclear magnetic resonance (NMR) spectra confirm the purity and molecular structures of P(3HB-co-3HHx) and ENR-25. FTIR spectra for different compositions of P(3HB-co-3HHx) and ENR-25 blends show absorbance change of the absorbance bands but with no significant shifting of the absorbance bands as the P(3HB-co-3HHx) content decreases, which shows that there is no intermolecular interaction between the parent polymer blends. On top of that, there are two Tgs present for the blends and both remain constant for different compositions which corresponds to the Tgs of the parent polymers. This indicates that the blends are immiscible

  3. Synthesis, characterization and ellipsometric study of ultrasonically sprayed Co3O4 films

    Gençyılmaz, O.; Taşköprü, T.; Atay, F.; Akyüz, İ.


    In the present study, cobalt oxide (Co3O4) films were produced using ultrasonic spray pyrolysis technique onto the glass substrate at different temperatures (200-250-300-350 °C). The effect of substrate temperature on the structural, optical, surface and electrical properties of Co3O4 films was reported. Thickness, refractive index and extinction coefficient of the films were determined by spectroscopic ellipsometry, and X-ray diffraction analyses revealed that Co3O4 films were polycrystalline fcc structure and the substrate temperature significantly improved the crystal structure of Co3O4 films. The films deposited at 350 °C substrate temperature showed the best structural quality. Transmittance, absorbance and reflectance spectra were taken by means of UV-Vis spectrophotometer, and optical band gap values were calculated using optical method. Surface images and roughness values of the films were taken by atomic force microscopy to see the effect of deposition temperature on surface properties. The resistivity of the films slightly decreases with increase in the substrate temperature from 1.08 × 104 to 1.46 × 102 Ω cm. Finally, ultrasonic spray pyrolysis technique allowed production of Co3O4 films, which are alternative metal oxide film for technological applications, at low substrate temperature.

  4. Investigation of miscibility of p(3hydroxybutyrate-co-3hydroxyhexanoate) and epoxidized natural rubber blends

    Akram, Faridah; Chan, Chin Han; Natarajan, Valliyappan David [Faculty of Applied Sciences, Universiti Teknologi MARA, Shah Alam, 40450 Selangor Darul Ehsan (Malaysia)


    Poly(3-hydroxybutyrate-co-3-hydroxyhexanoate [P(3HB-co-3HHx)] produced by C. necator PHB{sup −}4 harboring phaC{sub cs} from crude palm kernel oil with 21 mol% of 3-hydroxyhexanoate and epoxidized natural rubber with 25 mol% of epoxy content (ENR-25) were used to study the miscibility of the blends by attenuated total reflection-Fourier transform infrared (ATR-FTIR) and differential scanning calorimetry (DSC). The polymers used were purified and the blends were prepared by solution casting method. Nuclear magnetic resonance (NMR) spectra confirm the purity and molecular structures of P(3HB-co-3HHx) and ENR-25. FTIR spectra for different compositions of P(3HB-co-3HHx) and ENR-25 blends show absorbance change of the absorbance bands but with no significant shifting of the absorbance bands as the P(3HB-co-3HHx) content decreases, which shows that there is no intermolecular interaction between the parent polymer blends. On top of that, there are two T{sub g}s present for the blends and both remain constant for different compositions which corresponds to the T{sub g}s of the parent polymers. This indicates that the blends are immiscible.

  5. The structural, electronic and dynamic properties of the L12- type Co3Ti alloy

    The structural, electronic and dynamic properties of the cubic Co3Ti alloy in L12 structure have been investigated using a pseudopotential plane wave (PP-PW) method within the generalized gradient approximation proposed by Perdew–Burke–Ernzerhof (GGA-PBE). The structural properties, including the lattice constant, the bulk modulus and its pressure derivative agree reasonably with the previous results. The density of state (DOS), projected density of state (PDOS) and electronic band structure are also reported. The DOS shows that Co3Ti alloy has a metallic character since the energy bands cross the Fermi level. The density of states at Fermi level mainly comes from the Co-3d states. Phonon dispersion curves and their corresponding total densities of states were obtained using a linear response in the framework of the density functional perturbation theory. All computed phonon frequencies are no imaginer and thus, Co3Ti alloy is dynamically stable. The zone center phonon modes have been founded to be 9.307, 9.626 and 13.891 THz for Co3Ti

  6. Epitaxy of polar semiconductor Co3O4 (110): Growth, structure, and characterization

    The (110) plane of Co3O4 spinel exhibits significantly higher rates of carbon monoxide conversion due to the presence of active Co3+ species at the surface. However, experimental studies of Co3O4 (110) surfaces and interfaces have been limited by the difficulties in growing high-quality films. We report thin (10–250 Å) Co3O4 films grown by molecular beam epitaxy in the polar (110) direction on MgAl2O4 substrates. Reflection high-energy electron diffraction, atomic force microscopy, x-ray diffraction, and transmission electron microscopy measurements attest to the high quality of the as-grown films. Furthermore, we investigate the electronic structure of this material by core level and valence band x-ray photoelectron spectroscopy, and first-principles density functional theory calculations. Ellipsometry reveals a direct band gap of 0.75 eV and other interband transitions at higher energies. A valence band offset of 3.2 eV is measured for the Co3O4/MgAl2O4 heterostructure. Magnetic measurements show the signature of antiferromagnetic ordering at 49 K. FTIR ellipsometry finds three infrared-active phonons between 300 and 700 cm−1.

  7. First principles study of structural stability and site preference in Co3 (W,X

    Joshi Sri Raghunath


    Full Text Available Since the discovery [1] of γ′ precipitate (L12 – Co3(Al, W in the Co-Al-W ternary system, there has been an increased interest in Co-based superalloys. Since these alloys have two phase microstructures (γ + γ′ similar to Ni-based superalloys [2], they are viable candidates in high temperature applications, particularly in land-based turbines. The role of alloying on stability of the γ′ phase has been an active area of research. In this study, electronic structure calculations were done to probe the effect of alloying in Co3W with L12 structure. Compositions of type Co3(W,X, (where X/Y = Mn, Fe, Ni, Pt, Cr , Al, Si, V, W, Ta, Ti, Nb, Hf, Zr and Mo were studied. Effect of alloying on equilibrium lattice parameters and ground state energies was used to calculate Vegard's coefficients and site preference related data. The effect of alloying on the stability of the L12 structure vis a vis other geometrically close packed ordered structures was also studied for a range of Co3X compounds. Results suggest that the penchant of element for the W sublattice can be predicted by comparing heats of formation of Co3X in different structures.

  8. Multifunctional Co3S4/graphene composites for lithium ion batteries and oxygen reduction reaction.

    Mahmood, Nasir; Zhang, Chenzhen; Jiang, Jie; Liu, Fei; Hou, Yanglong


    Cobalt sulfide is a good candidate for both lithium ion batteries (LIBs) and cathodic oxygen reduction reaction (ORR), but low conductivity, poor cyclability, capacity fading, and structural changes hinder its applications. The incorporation of graphene into Co3S4 makes it a promising electrode by providing better electrochemical coupling, enhanced conductivity, fast mobility of ions and electrons, and a stabilized structure due to its elastic nature. With the objective of achieving high-performance composites, herein we report a facile hydrothermal process for growing Co3S4 nanotubes (NTs) on graphene (G) sheets. Electrochemical impedance spectroscopy (EIS) verified that graphene dramatically increases the conductivity of the composites to almost twice that of pristine Co3S4. Electrochemical measurements indicated that the as-synthesized Co3S4/G composites exhibit good cyclic stability and a high discharge capacity of 720 mA h g(-1) up to 100 cycles with 99.9% coulombic efficiency. Furthermore, the composites react with dissolved oxygen in the ORR by four- and two-electron mechanisms in both acidic and basic media with an onset potential close to that of commercial Pt/C. The stability of the composites is much higher than that of Pt/C, and exhibit high methanol tolerance. Thus, these properties endorse Co3 S4 /G composites as auspicious candidates for both LIBs and ORR. PMID:23447515

  9. Ultrathin Co3 O4 Layers Realizing Optimized CO2 Electroreduction to Formate.

    Gao, Shan; Jiao, Xingchen; Sun, Zhongti; Zhang, Wenhua; Sun, Yongfu; Wang, Chengming; Hu, Qitao; Zu, Xiaolong; Yang, Fan; Yang, Shuyang; Liang, Liang; Wu, Ju; Xie, Yi


    Electroreduction of CO2 into hydrocarbons could contribute to alleviating energy crisis and global warming. However, conventional electrocatalysts usually suffer from low energetic efficiency and poor durability. Herein, atomic layers for transition-metal oxides are proposed to address these problems through offering an ultralarge fraction of active sites, high electronic conductivity, and superior structural stability. As a prototype, 1.72 and 3.51 nm thick Co3 O4 layers were synthesized through a fast-heating strategy. The atomic thickness endowed Co3 O4 with abundant active sites, ensuring a large CO2 adsorption amount. The increased and more dispersed charge density near Fermi level allowed for enhanced electronic conductivity. The 1.72 nm thick Co3 O4 layers showed over 1.5 and 20 times higher electrocatalytic activity than 3.51 nm thick Co3 O4 layers and bulk counterpart, respectively. Also, 1.72 nm thick Co3 O4 layers showed formate Faradaic efficiency of over 60 % in 20 h. PMID:26783062

  10. Pulsed laser deposition of Co3O4 nanocatalysts for dye degradation and CO oxidation

    Co3O4 nanoparticles (NPs) assembled coatings were synthesized using pulsed laser deposition (PLD) by taking advantage of phase explosion process. The coatings were prepared at substrate temperature of 150 °C by using three different laser fluences (3, 5, and 7 J/cm2) in order to tune the size of NPs. Structural property and surface morphology of NPs were investigated by Raman spectroscopy and electron microscopy respectively. The catalytic activity of these Co3O4 NPs coatings was tested for dye degradation as well as for CO oxidation. Co3O4 coating (3 J/cm2) was able to completely degrade Methylene blue dye with significantly high rate, via photo Fenton reaction under visible light irradiation, as compared to Co3O4 powder catalyst mainly owing to the size and nanocrystalline nature of NPs on the catalyst surface. Coating synthesized at low laser fluence (3 J/cm2) showed best catalytic activity. This particular coating also showed above 90% conversion efficiency of CO to CO2 at 250 °C with very high specific rate. The special features of NPs, such as narrow size distribution, small average size (5–20 nm), perfect spherical shape, low degree of agglomeration, and nanocrystalline phase, are the main factors responsible for the enhanced catalytic activity of the PLD produced Co3O4 NPs assembled coating.

  11. Donut-shaped Co3O4 nanoflakes grown on nickel foam with enhanced supercapacitive performances

    Han, Zhicheng; Zheng, Xin; Yao, Shunyu; Xiao, Huanhao; Qu, Fengyu; Wu, Xiang


    Donut-shaped Co3O4 nanoflakes grown on nickel foam were successfully fabricated by a simple one-pot hydrothermal approach. The prepared products were functionalized as the supercapacitors electrodes. Electrochemical performance of the as-prepared products demonstrated high specific capacitance (518 mF cm-2) and excellent cycling stability (∼25% loss) after 6000 repetitive cycles at a charge-discharge current density of 1 mA cm-2. The superior electrochemical performance may be ascribed into two reasons: one is the unique spatial structures which possess many active sites and provide enhanced combination between the electrode and nickel foam to support fast ion and electron transfer, the other is that donut-shaped Co3O4 nanoflakes electrodes show relatively lower resistances. It is expected that the as-obtained donut-shaped Co3O4 nanoflakes could have potential applications in portable electronics and electrical vehicles.

  12. Synthesis and Characterization of MWCNT/ CaCO3 Hybrid Compound

    Since their discovery, carbon nano tubes (CNT) have been actively researched and drawn a great interest for a wide variety of potential application. Several of synthesis method have been developed for the production of CNT. In this work, the chemical vapor deposition (CVD) technique was used to synthesis the multi walled carbon nano tubes/ calcium carbonate (MWCNT/ CaCO3) hybrid compound. A gas mixture of CH4/ N2 was used as the source of carbon and Ni/ CaCO3 compound was used as catalyst for the growth of the hybrid compound. The catalyst was prepared using nickel salt and CaCO3 mixture via coprecipitation method. The process was then followed by drying, calcination, reduction and growth the CNT in the tube furnace. The resulted compound was then analysed using XRD, SEM and HRTEM. (author)

  13. A parametric study of CaCO3 scaling in AISI 316 stainless steel tubes

    Khan, M. Sultan; Budair, M. O.; Zubair, S. M.

    The formation of undesirable layer of deposits on the heat-transfer surface is defined as fouling. These deposits present a major problem in the operation and maintenance of heat exchangers, particularly in cooling-water systems. It has been generally observed that the deposits in such systems consist mainly of calcium carbonate (CaCO3), which has inverse solubility characteristics. An experimental study was carried out to determine the effect of tube surface temperature, Reynolds number, tube diameter and salt concentration on the growth of CaCO3 scale. In this paper, effects of some of these parameters on fouling growth are discussed. The effect of CaCO3 concentration on the scale growth is compared with the ionic diffusion model presented by Hasson. The variation of the fouling thickness along the length of the heat exchanger is also illustrated. Furthermore, dimensionless parameters are introduced to present the fouling resistance data collected during the experimental study.

  14. Ultrathin mesoporous Co3O4 nanosheets on Ni foam for high-performance supercapacitors

    Ultrathin Co3O4 nanosheets with a mesoporous structure and a large surface area are hydrothermally grown on a three dimensional nickel foam. The ultrathin mesoporous Co3O4 nanosheets are grown on Ni foam with robust adhesion, which endows fast ion and electron transport, large electroactive surface area, and excellent structural stability. Such unique nanoarchitecture exhibits remarkable electrochemical performance with high capacitance and desirable cycle life. When evaluate as an electrode material for supercapacitors, the Co3O4 nanosheets electrode is able to deliver high specific capacitance of 2194 F g−1 at a current density of 1 A g−1 in 1 M KOH aqueous solution. The electrode also exhibits excellent cycling stability by retaining 93.1% of the maximum capacitance after 5000 charge-discharge cycles. The fabrication strategy presented here is facile, cost-effective, and can offer a way for energy storage device applications

  15. Ordered CoSn-type ternary phases in Co3Sn3-xGex

    Allred, Jared M.; Jia, Shuang; Bremholm, Martin; Chan, Benny C.; Cava, Robert J.


    CoSn is the prototype compound of the B35 structure, which has long been of interest due to its rarity and unusually low packing density. We report the synthesis and properties of the solid solution Co3Sn3-xGex for 0 ⩽ x ⩽ 2, in order to clarify the conditions necessary to stabilize such a phase....... By taking advantage of the chemical differences between the two crystallographically inequivalent Sn sites in the structure, we observe ordered ternary phases, nominally Co3SnGe2 and Co3Sn2Ge. The electron count and unit cell configuration remain unchanged from CoSn; these observations thus help to...

  16. PUA/PSS multilayer coated CaCO3 microparticles as smart drug delivery vehicles.

    Du, Chao; Shi, Jun; Shi, Jin; Zhang, Li; Cao, Shaokui


    Hybrid CaCO3 microparticles coated by sodium poly(styrene sulfonate) (PSS) and aliphatic poly(urethane-amine) (PUA) were developed as thermal-/pH-responsive drug delivery vehicles via LbL self-assembly technique. The DOX release from the CaCO3 microparticles was higher than 60% within 36 h, whereas the value of PUA/PSS-coated microparticles was only 20%. The results demonstrated that the PUA/PSS multilayer coating could reduce the drug release rate and significantly assuage the initial burst release of DOX. In addition, the drug release of the hybrid microparticles was found to be thermal-/pH-dual responsive. More interestingly, more than 90% of DOX was released in 36 h at pH2.1 and 55 °C owing to the combined action of the dissolution of the CaCO3 core and the shrinkage of aliphatic PUA. PMID:23910272

  17. AC Humidity Sensing Properties of Mesoporous K2CO3-SiO2 Composite Materials

    Liang Guo


    Full Text Available The mesoporous silica SBA-15 and mesoporous K2CO3-SiO2 composite material were synthesized. Characterization of microstructure and morphology of materials indicated that the composite material had saved the porous framework of mesoporous silica SBA-15. Humidity sensing properties of different inverse proportion K2CO3-SiO2 composite material were studied and we found that the sample with 0.16 g/g K2CO3 exhibited excellent linearity in the wide humidity range. The complex impedance changed five orders of magnitude from 11% RH to 95% RH. The rapid response and recovery time were 10 s and 38 s, respectively. Finally a feasible ion transfer mechanism was brought forward to explain the sensing mechanism.

  18. A high-pressure study of PbCO3 by XRD and Raman spectroscopy

    Zhang, Yu-Feng; Liu, Jing; Qin, Zhen-Xing; Lin, Chuan-Long; Xiong, Lun; Li, Rui; Bai, Li-Gang


    The pressure-induced phase transitions of PbCO3 are studied using synchrotron radiation in a diamond anvil cell at room temperature. The XRD measurement indicates that PbCO3 with an initial phase of aragonite-type structure undergoes two phase transitions at ~7.8 GPa and ~15.7 GPa, respectively. The higher-pressure phase appearing at ~15.7 GPa is stable up to 51.8 GPa. The two phase transitions are further confirmed by Raman scattering up to 23.3 GPa. During the decompression process, the high-pressure phases of PbCO3 are gradually recovered to the starting aragonite-type structure, but exhibit some hysteresis. The bulk modulus B0 of the aragonite-type structure is obtained to be 63±(3) GPa by fitting the volume-pressure data to the Birch—Murnaghan equation of states with B'0 fixed to 4.

  19. Formic Acid Modified Co3O4-CeO2 Catalysts for CO Oxidation

    Ruishu Shang


    Full Text Available A formic acid modified catalyst, Co3O4-CeO2, was prepared via facile urea-hydrothermal method and applied in CO oxidation. The Co3O4-CeO2-0.5 catalyst, treated by formic acid at 0.5 mol/L, performed better in CO oxidation with T50 obtained at 69.5 °C and T100 obtained at 150 °C, respectively. The characterization results indicate that after treating with formic acid, there is a more porous structure within the Co3O4-CeO2 catalyst; meanwhile, despite of the slightly decreased content of Co, there are more adsorption sites exposed by acid treatment, as suggested by CO-TPD and H2-TPD, which explains the improvement of catalytic performance.

  20. Co3O4@MWCNT nanocable as cathode with superior electrochemical performance for supercapacitors.

    Wang, Xiaowei; Li, Minxia; Chang, Zheng; Yang, Yaqiong; Wu, Yuping; Liu, Xiang


    Using a simple hydrothermal procedure, cobalt oxide (Co3O4) with preferred orientation along (220) planes is in situ prepared and coated on MWCNT. The prepared Co3O4@MWCNT nanocable shows superior electrochemical performance as cathode material for aqueous supercapacitors in 0.5 M KOH solution. Its redox peaks retain the well-defined shapes even when the scan rate increases to 200 mV/s. Its specific capacitance is high, 590 F/g at 15 A/g and 510 F/g even at 100 A/g within the potential range from -0.2 to 0.58 V (vs SCE). There is no capacitance fading after 2000 full cycles. This excellent performance is superior to the pristine and the reported Co3O4, which is ascribed to the unique nanocable structure with orientation. PMID:25591171

  1. A facile method to fabricate porous Co3O4 hierarchical microspheres

    Flower-like Co3O4 hierarchical microspheres composed of self-assembled porous nanoplates have been prepared by a two-step method without employing templates. The first step involves the synthesis of flower-like Co(OH)2 microspheres by a solution route at low temperatures. The second step includes the calcination of the as-prepared Co(OH)2 microspheres at 200 deg. C for 1 h, causing their decomposition to form porous Co3O4 microspheres without destruction of their original morphology. The samples were characterized by scanning electron microscope, transmission electron microscope, X-ray diffractormeter and Fourier transform infrared spectroscope. Some experimental factors including solution temperature and surfactant on the morphologies of the final products have been investigated. The magnetic properties of Co3O4 microspheres were also investigated. - Graphical Abstract: Flower-like Co3O4 microspheres are composed of self-assembled nanoplates and these nanoplates appear to be closely packed in the microspheres. These nanoplates consist of a large number of nanocrystallites less than 5 nm in size with a porous structure, in which the connection between nanocrystallites is random. Research Highlights: → Flower-like Co3O4 hierarchical microspheres composed of self-assembled porous nanoplates have been prepared by a two-step method without employing templates. → Layered Co(OH)2 microspheres were prepared with an appropriate approach under low temperatures for 1 h reaction. → Calcination caused Co(OH)2 decomposition to form porous Co3O4 microspheres without destruction of their original morphology.

  2. Insight into electrochemical properties of Co3O4–modified magnetic polymer electrolyte

    Highlights: • A novel cobaltosic oxide-modified magnetic agarose electrolyte. • Magnetic field–induced ordered microstructure and increased ionic conductivity. • Improved recombination process and good long-term stability of DSSCs after magnetic field treatment. • Better photovoltaic performance of the Co3O4-modified DSSC than that of NiO-modified DSSC under magnetic field treatment. - Abstract: Agarose–based electrolyte containing magnetic Co3O4 nanoparticles is studied for quasi–solid–state dye–sensitized solar cells (DSSCs) under external magnetic field treatment. SEM studies reveal the existence of oriented microstructure in Co3O4–modified agarose electrolyte film under proper magnetic field intensity. The formation mechanism of this ordered structure induced by magnetic field is analyzed. The impedance analysis shows that the ionic conductivity of Co3O4–modified agarose electrolyte is obviously increased by applying magnetic field intensity of 25 mT. Improved electron recombination process and photoelectric performance are observed in DSSCs under certain magnetic field treatment by electrochemical impedance spectra (EIS) and photovoltaic studies. The DSSC treated with magnetic field can maintain the efficiency unchanged for 434 hours without sealing. This is attributed to the high ionic conductivity and improved electron transfer process in DSSC resulting from the magnetic field treatment. Comparison of photovoltaic performances for Co3O4 and NiO modified DSSCs under 25 mT magnetic field treatment shows that Co3O4-modified DSSC exhibits higher energy conversion efficiency than that of NiO-modified one at the same condition

  3. Facile synthesis of porous Co3O4 nanoplates for supercapacitor applications

    Tao Geng; Li Zhang; Hongyan Wang; Keying Zhang; Xia Zhou


    Porous tricobalt tetraoxide (Co3O4) nanoplates with large aspect ratio have been obtained by annealing Co(OH)2 precursor nanoplates synthesized by a facile reflux method without the need for any template or surfactant. After the heat treatment, the as-obtained phase-pure Co3O4 nanoplates with a wellretained structure were applied as the electrode material for supercapacitors, and the sample exhibits excellent performance with a high specific capacitance of 225 F g–1 after 2000 charge–discharge cycles at 2 A g–1, corresponding to a retention of 97% of the initial capacitance.

  4. Testing the cation-hydration effect on the crystallization of Ca–Mg–CO3 systems

    Xu, Jie; Yan, Chao; Zhang, Fangfu; Konishi, Hiromi; Xu, Huifang; Teng, H. Henry


    Magnesium-bearing carbonate minerals play critical roles in the health and function of the Earth system because they constitute a significant fraction of lithosphere carbon reservoir and build skeletal structures for the majority of marine invertebrate organisms. Despite wide occurrence, high-Mg and sole-Mg phases such as dolomite ([Ca,Mg]CO3) and magnesite (MgCO3) prove virtually impossible to be crystallized under ambient conditions. It has long been believed that Mg2+ hydration is the caus...

  5. Interdiffusion between Co3O4 coating and the oxide scale of Fe-22Cr alloy

    Hansson, Anette Nørgaard; Friehling, Peter B.; Linderoth, Søren; Somers, Marcel A.J.


    In solid oxide fuels cell stacks, the Fe-Cr interconnector plates and their oxidation scale formed during operation must have sufficiently high electrical conductivity at the operating temperature. It is anticipated that this can be achieved by reaction-diffusion between Co3O4 and the chromia sca...... of inter-diffusion between the oxide scale and the Co3O4 coating were investigated with X-ray diffraction, scanning electron microscopy and energy-dispersive spectroscopy. The results obtained are discussed in relation to a calculated Cr-Co-oxide phase diagrams....

  6. Improved reactivity of large coal particles by K2CO3 addition during steam gasification

    Coetzee, Sansha; Neomagus, Hein W J P; Bunt, John R.; Everson, Raymond C.


    In this study, the excess solution impregnation method was used to impregnate large coal particles (5 and 10 mm) with K2CO3, and the effect of the additive on steam gasification reactivity was investigated. A washed bituminous, medium rank-C Highveld coal, with an ash content of 12.6 wt.% (air-dried basis), was used for experimentation. The excess solution method was used to impregnate coal particles with the selected additive, K2CO3, and results from XRF analysis indicated that t...

  7. Single Crystalline Co3O4 Nanocrystals Exposed with Different Crystal Planes for Li-O2 Batteries

    Su, Dawei; Dou, Shixue; Wang, Guoxiu


    Single crystalline Co3O4 nanocrystals exposed with different crystal planes were synthesised, including cubic Co3O4 nanocrystals enclosed by {100} crystal planes, pseudo octahedral Co3O4 enclosed by {100} and {110} crystal planes, Co3O4 nanosheets exposed by {110} crystal planes, hexagonal Co3O4 nanoplatelets exposed with {111} crystal planes, and Co3O4 nanolaminar exposed with {112} crystal planes. Well single crystalline features of these Co3O4 nanocrystals were confirmed by FESEM and HRTEM analyses. The electrochemical performance for Li-O2 batteries shows that Co3O4 nanocrystals can significantly reduce the discharge-charge over-potential via the effect on the oxygen evolution reaction (OER). From the comparison on their catalytic performances, we found that the essential factor to promote the oxygen evolution reactions is the surface crystal planes of Co3O4 nanocrystals, namely, crystal planes-dependent process. The correlation between different Co3O4 crystal planes and their effect on reducing charge-discharge over-potential was established: {100} < {110} < {112} < {111}.

  8. Enzyme-assisted growth of nacreous CaCO3/polymer hybrid nanolaminates via the formation of mineral bridges

    Yeom, Bongjun; Char, Kookheon


    Laminated nanostructures in nacre have been adopted as models in the fabrication of strong, tough synthetic nanocomposites. However, the utilization of CaCO3 biominerals in these composites is limited by the complexity of the synthesis method for nanosized biominerals. In this study, we use the enzymatic reaction of urease to generate a nanoscale CaCO3 thin film to prepare CaCO3/polymer hybrid nanolaminates. Additional layers of CaCO3 thin film are consecutively grown over the base CaCO3 layer with the intercalation of organic layers. The morphology and crystallinity of the added CaCO3 layers depend strongly on the thickness of the organic layer coated on the underlying CaCO3 layer. When the organic layer is less than 20 nm thick, the amorphous CaCO3 layer is spontaneously transformed into crystalline calcite layer during the growth process. We also observe crystalline continuity between adjacent CaCO3 layers through interconnecting mineral bridges. The formation of these mineral bridges is crucial to the epitaxial growth of CaCO3 layers, similar to the formation of natural nacre.

  9. Preparation of Ag2O/Ag2CO3/MWNTs composite photocatalysts for enhancement of ciprofloxacin degradation

    Wang, Huiqin; Li, Jinze; Huo, Pengwei; Yan, Yongsheng; Guan, Qingfeng


    The Ag2O/Ag2CO3/multi-walled carbon nanotube (MWNTs) composite photocatalysts were prepared by calcination of the obtained precipitate. The structures and morphology of as-prepared composite photocatalysts were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), diffuse reflectance spectroscopy (DRS), photoluminescence (PL) spectroscopy, X-ray photoelectron spectroscopy (XPS). The Ag2O/Ag2CO3/MWNTs composite photocatalysts exhibit higher degradation rate of ciprofloxacin (CIP) than the pure Ag2CO3, Ag2O/Ag2CO3 and Ag2CO3/MWNTs under visible light irradiation. The amount of loaded Ag2CO3 onto MWNTs and calcined time for Ag2CO3/MWNTs were systematically investigated, and the optimal amount of loaded Ag2CO3 and calcined time of Ag2CO3/MWNTs are 150 wt% and 10 min, respectively. The highest photocatalytic degradation rate of CIP could reach 76% under optimal conditions. The active species trapping experiments were also analyzed, the results show that the holes are main contributor for the degradation processes of CIP, furthermore the electrons, rad O2- and rad OH are also crucially influenced the photocatalytic degradation processes of CIP. The possible photocatalytic processes of CIP with Ag2O/Ag2CO3/MWNTs composite photocatalyst are also proposed.

  10. Observation of atomic steps on CaCO3 crystal surface

    SunJie-Lin; HuJun; 等


    By using scanning polarization force microscopy,the deliquescence process and the atomic steps on the cleavage surface of CaCO3 in air were studied in situ.Under an exposure to medium umidity(-57%),the sloiw step movement has been observed.

  11. Porous Co3O4 hollow nanododecahedra for nonenzymatic glucose biosensor and biofuel cell.

    Zhang, Erhuan; Xie, Yu; Ci, Suqin; Jia, Jingchun; Wen, Zhenhai


    Cobalt oxide hollow nanododecahedra (Co3O4-HND) is synthesized by a facile thermal transformation of cobalt-based metal-organic framework (Co-MOF, ZIF-67) template. The morphology and properties of the Co3O4-HND are characterized by a set of techniques, including transmission electron microscope (TEM), powder X-ray diffraction (XRD), scanning electron microscope (SEM) and Brunner-Emmet-Teller (BET). When tested as a non-enzymatic electrocatalyst for glucose oxidation reaction, the Co3O4-HND exhibits a high activity and shows an outstanding performance for determining glucose with a wide window of 2.0μM to 6.06mM, a high sensitivity of 708.4μAmM(-1)cm(-2), a low detection limit of 0.58μM (S/N=3), and fast response time(glucose, Co3O4-HND could be served as an attractive non-enzyme and noble-metal-free electrocatalyst in glucose fuel cell (GFC) due to its excellent electrochemical properties, low cost and facile preparation. PMID:26918617

  12. Hierarchically triangular prism structured Co3O4: Self-supported fabrication and photocatalytic property

    The formation of ammonium cobalt (II) phosphate was utilized to synthesize unprecedented 3D structures of Co3O4, triangular prisms and trunk-like structures, via a self-supported and organics-free method. The length of a triangular side of the prepared 3D triangular prisms is ~1...

  13. CaCO3 nanoparticle synthesis by carbonation of lime solution in microemulsion systems

    Sugih, A.K.; Shukla, D.; Heeres, H.J.; Mehra, A.


    Various aspects of nanoparticle precipitation in gas-reverse micellar systems have been studied. The experimental system chosen for investigation deals with the precipitation of CaCO3 nanoparticles. The effect of operating variables, such as water-to-surfactant molar ratio, different continuous phas

  14. Co3O4–ZnO hierarchical nanostructures by electrospinning and hydrothermal methods

    Kanjwal, Muzafar Ahmed; Sheikh, Faheem A.; Barakat, Nasser A.M.;


    A new hierarchical nanostructure that consists of cobalt oxide (Co3O4) and zinc oxide (ZnO) was produced by the electrospinning process followed by a hydrothermal technique. First, electrospinning of a colloidal solution that consisted of zinc nanoparticles, cobalt acetate tetrahydrate and poly...

  15. Interferometric CO(3-2) Observations toward the Central Region of NGC 1068

    Tsai, Mengchun; Matsushita, Satoki; Baker, Andrew J; Espada, Daniel


    We present CO(3-2) interferometric observations of the central region of the Seyfert 2 galaxy NGC 1068 using the Submillimeter Array, together with CO(1-0) data taken with the Owens Valley Radio Observatory Millimeter Array. Both the CO(3-2) and CO(1-0) emission lines are mainly distributed within ~5 arcsec of the nucleus and along the spiral arms, but the intensity distributions show differences; the CO(3-2) map peaks in the nucleus, while the CO(1-0) emission is mainly located along the spiral arms. The CO(3-2)/CO(1-0) ratio is about 3.1 in the nucleus, which is four times as large as the average line ratio in the spiral arms, suggesting that the molecular gas there must be affected by the radiation arising from the AGN. On the other hand, the line ratios in the spiral arms vary over a wide range from 0.24 to 2.34 with a average value around 0.75, which is similar to the line ratios of star-formation regions, indicating that the molecular gas is affected by star formation. Besides, we see a tight correlatio...

  16. Click chemistry for [99mTc(CO)3] labeling of Lys3-bombesin

    99mTc-HYNIC labeled Lys3-bombesin has shown specific binding to gastrin-releasing peptide receptors (GRP-r) over-expressed in cancer cells. Click chemistry offers an innovative functionalization strategy for biomolecules such as bombesin. The aim of this research was to apply a click chemistry approach for [99mTc(CO)3] labeling of Lys3-bombesin and to compare the in vitro MCF7 breast cancer cell uptake and biodistribution profile in mice with that of 99mTc-EDDA/HYNIC-Lys3-bombesin. The results suggest a higher lipophilicity for 99mTc(CO)3-triazole-Lys3-bombesin which explains its higher in vivo hepatobiliary elimination. Pancreas-to-blood ratio for 99mTc(CO)3-triazole-Lys3-bombesin was 4.46 at 3 h and both bombesin radiopharmaceuticals showed specific recognition for GRP receptors in MCF7 cancer cells. Click chemistry is a reliable approach for [99mTc(CO)3] labeling of Lys3-bombesin.

  17. Electron-beam induced deposition and autocatalytic decomposition of Co(CO3NO

    Florian Vollnhals


    Full Text Available The autocatalytic growth of arbitrarily shaped nanostructures fabricated by electron beam-induced deposition (EBID and electron beam-induced surface activation (EBISA is studied for two precursors: iron pentacarbonyl, Fe(CO5, and cobalt tricarbonyl nitrosyl, Co(CO3NO. Different deposits are prepared on silicon nitride membranes and silicon wafers under ultrahigh vacuum conditions, and are studied by scanning electron microscopy (SEM and scanning transmission X-ray microscopy (STXM, including near edge X-ray absorption fine structure (NEXAFS spectroscopy. It has previously been shown that Fe(CO5 decomposes autocatalytically on Fe seed layers (EBID and on certain electron beam-activated surfaces, yielding high purity, polycrystalline Fe nanostructures. In this contribution, we investigate the growth of structures from Co(CO3NO and compare it to results obtained from Fe(CO5. Co(CO3NO exhibits autocatalytic growth on Co-containing seed layers prepared by EBID using the same precursor. The growth yields granular, oxygen-, carbon- and nitrogen-containing deposits. In contrast to Fe(CO5 no decomposition on electron beam-activated surfaces is observed. In addition, we show that the autocatalytic growth of nanostructures from Co(CO3NO can also be initiated by an Fe seed layer, which presents a novel approach to the fabrication of layered nanostructures.

  18. Exploring the Potential of (99m)Tc(CO)3-Labeled Triazolyl Peptides for Tumor Diagnosis.

    Gaonkar, Raghuvir H; Ganguly, Soumya; Baishya, Rinku; Dewanjee, Saikat; Sinha, Samarendu; Gupta, Amit; Ganguly, Shantanu; Debnath, Mita C


    In recent years the authors have reported on (99m)Tc(CO)3-labeled peptides that serve as carriers for biomolecules or radiopharmaceuticals to the tumors. In continuation of that work they report the synthesis of a pentapeptide (Met-Phe-Phe-Gly-His; pep-1), a hexapeptide (Met-Phe-Phe-Asp-Gly-His; pep-2), and a tetrapeptide (Asp-Gly-Arg-His; pep-3) and the attachment of 3-amino-1,2,4-triazole to the β carboxylic function of the aspartic acid unit of pep-2 and pep-3. The pharmacophores were radiolabeled in high yields with [(99m)Tc(CO)3(H2O)3](+) metal aqua ion, characterized for their stability in serum and saline, as well as in His solution, and found to be substantially stable. B16F10 cell line binding studies showed favorable uptake and internalization. In vivo behavior of the radiolabeled triazolyl peptides was assessed in mice bearing induced tumor. The (99m)Tc(CO)3-triazolyl pep-3 demonstrated rapid urinary clearance and comparatively better tumor uptake. Imaging studies showed visualization of the tumor using (99m)Tc(CO)3-triazolyl pep-3, but due to high abdominal background, low delineation occurred. Based on the results further experiments will be carried out for targeting tumor with triazolyl peptides. PMID:27093344

  19. Synthesis, characterization and self-assembly of Co3+ complexes appended with phenol and catechol groups

    Afsar Ali; Deepak Bansal; Rajeev Gupt


    This work presents the syntheses, characterization and hydrogen bonding based self-assembly of Co3+ complexes of pyridine-amide based bidentate ligands containing appended phenol and catechol groups. Placement of multiple hydrogen bond donors (phenolic OH and amidic NH groups) and acceptors (Oamide groups) in these molecules results in interesting self-assembled architectures.

  20. Theoretical Study on Co3+ in Aqueous Solution in Terms of ABEEM/MM Model

    GUAN,Qing-Mei; YANG,Zhong-Zhi


    A detailed theoretical investigation on Co3+ hydration in aqueous solution has been carried out by means of molecular dynamics (MD) simulations based on the atom-bond electronegativity equalization method fused into molecular mechanics (ABEEM/MM). The effective Co3+ ion-water potential has been constructed by fitting to ab initio structures and binding energies for ionic clusters. And then the ion-water interaction potential was applied in combination with the ABEEM-7P water model to molecular dynamics simulations of single Co3+(aq.) solution, managing to reproduce many experimental structural and dynamical properties of the solution. Here, not only the common properties (radial distribution function, angular distribution function and solvation energy) obtained for Co3+ in ABEEM-7P water solution were in good agreement with those from the experimental methods and other molecular dynamics simulations but also very interesting properties of charge distributions, geometries of water molecules, hydrogen bond, diffusion coefficients, vibrational spectra are investigated by ABEEM/MM model.

  1. Fabrication and Characterization of Nano-CaCO3/Polypropylene Foam Sheets


    By applying the reinforcing and toughening effect of calcium carbonate (CaCO3) nanoparticles on polypropylene, foam sheets of good performance were successfully fabricated by extrusion. The equipment and conditions of the extrusion were explored. The mechanical properties of the produced foam sheets were tested. The effect of CaCO3 nano-particles on the mechanical properties and the cellular structure of the sheets was comprehensively studied. The experimental results show that the optimum content of CaCO3 nano-particles in the composite material was~4wt%. At this content, the nano-particles were well dispersed in the substrate, and the composite material had maximum tensile strength and impact strength. Surface treatment of the nano-particles only affected the impact strength of the composite material. CaCO3 micro-particles, on the other hand, showed little effect on the properties of the composite material when the micro-particles content was less than 5 wt%. At a content higher than 5wt%, the properties of the composite material significantly worsened.

  2. Preparation of Co3O4 Nanofibers via an Electrospinning Technique

    Chang Lu SHAO; Hong Yu GUAN; Shang Bin WEN; Bin CHEN; Xing Hua YANG; Jian GONG; Yi Chun LIU


    Thin PVA/cobalt acetate composite fibers were prepared by using sol-gel processing and electrospinning technique.After calcination of the above precursor fibers, Co3O4 nanofibers with a diameter of 50-150 nm could be successfully obtained.The fibers were characterized by SEM, FT-IR,WAXD,respectively.

  3. Preparation and evaluation of New [99Tcm (CO3]+-Labelled phenanthroline complexes

    The chief requirement to determine if pharmaceuticals may be AD-tracer is that complexes can pass through BBB to enter the brain and have rapid clean from the brain. To develop early diagnose radiopharmaceuticals for Alzheimer's disease, new phenanthroline complexes 2-(9-anthryl)-1H-imidazo [4, 5-f] [1, 10] phenanthroline (aip) and 2-(9-anthryl)-1ethyl-imidazo [4, 5-f] [1, 10] phenanthroline (aeip) based on the early research of Ru complexes banding to DNA used for fluescence method were synthesized and labelled by 99Tcm-tricarbonyl core. Radiochemical purities of complexes 99Tcm(CO)+3-aip and 99Tcm(CO)+3-aeip were found to be more than 95% as proved by radio-HPLC. Paper electrophoresis show that these complexes are neutral. Biodistribution of these complexes in mice shows the higher early uptakes in brain(2 min, 99Tcm(CO)+3-aip: (1.028 ± 0.096)%ID/g; 99Tcm(CO)+3-aeip: (1.191 ± 0.197)%ID/g). (authors)

  4. Morphological Control of Co3O4 and Its Photocatalytic Properties

    Cobaltosic oxide (Co3O4), a p-type semiconductor, belongs to the normal spinel crystal structure based on a cubic close packing array of oxide ions. The size, surface, geometry, and crystal phase of catalysts are important parameters for controlling their chemical, optical, and ...

  5. Co3O4@Reduced Graphene Oxide Nanoribbon for high performance Asymmetric Supercapacitor

    Graphical abstract: Display Omitted -- Abstract: In the work, we have successfully fabricated an aqueous, high potential asymmetric supercapacitor (ASC) based on Co3O4/reduced graphene oxide nanoribbon (RGONR) hybrid electrodes. Here, Co3O4/RGONR film worked as the positive electrode while RGONR film served as negative electrode in the designed ASC. Uniformly immobilized Co3O4 nanoparticles (NPs) onto graphene nanoribbon have the advantage of high electronic conductivity via underlying RGONR with short ion diffusion path in uniform mesoporous structure. As a consequence, ASC Co3O4/RGONR//RGONR exhibited 1.6 V wide operating potential window for charge storage along with significantly improved capacitive performance than symmetric counterpart. It also demonstrates superior device performance with energy density, 64.2 Wh kg−1 (much higher than that of symmetric cell) with high power density, 8.3 kW Kg−1 due to optimized mass ratio of the electrodes. In addition, it reveals long term charge/discharge cycling stability with ~94% capacitance retention after 2000 cycles. This high-performance hybrid ASC pave their way for promising applications of pulse power systems

  6. Study on Tensile Properties of PVC Drainage Pipe Synergistic with ACR/CaCO3%ACR与CaCO3协同作用对PVC管材拉伸性能的研究



    CaCO3, ACR, CaCO3 and ACR blends on the tensile properties of PVCdrainage pipe. When the CaCO3 in an amount up to 20 parts and the ACR amount of 5 parts, The results showed that: the tensile strength is about 40MPa,the elongation at break reaches 120%.%分别研究了CaCO3、ACR、CaCO3与ACR共混体对PVC排水管材的拉伸性能的影响。CaCO3的用量达到20%、用量5%时,当ACR管材的拉伸强度为40MPa,断裂仲长率为120%。

  7. Study of Filling of PVC/CPE Composite by Nano-CaCO3%纳米级CaCO3填充PVC/CPE复合材料研究

    胡圣飞; 严海标; 王燕舞; 林志云



  8. Highly acid-durable carbon coated Co3O4 nanoarrays as efficient oxygen evolution electrocatalysts

    Yang, Xiulin


    Most oxygen evolution reaction (OER) electrocatalysts are not stable in corrosive acids. Even the expensive RuO2 or IrO2, the most acid-resistant oxides, can be dissolved at an oxidative potential. Herein, we realize that the failures of OER catalysts are mostly caused by the weak interface between catalysts and the substrates. Hence, the study of the interface structure between catalysts and substrates is critical. In this work, we observe that the cheap OER catalysts Co3O4 can be more durable than the state-of-the-art RuO2 if the interface quality is good enough. The Co3O4 nanosheets deposited on carbon paper (Co3O4/CP) is prepared by electroplating of Co-species and followed by a two-step calcination process. The 1st step occurs in vacuum in order to maintain the surface integrity of the carbon paper and converts Co-species to Co(II)O. The 2nd step is a calcination in ambient conditions which enables the complete transformation of Co(II)O to Co3O4 without degrading the mechanical strength of the Co3O4-CP interface. Equally important, an in situ formation of a layer of amorphous carbon on top of Co3O4 further enhances the OER catalyst stability. Therefore, these key advances make the Co3O4 catalyst highly active toward the OER in 0.5 M H2SO4 with a small overpotential (370 mV), to reach 10 mA/cm2. The observed long lifetime for 86.8 h at a constant current density of 100 mA/cm2, is among the best of the reported in literature so far, even longer than the state-of-art RuO2 on CP. Overall, our study provides a new insight and methodology for the construction of a high-performance and high stability OER electrocatalysts in corrosive acidic environments.

  9. 超细CaCO3对ABS材料力学性能的影响%Effect of ultrafine CaCO3 on mechanical properties of ABS blending material

    钱岑; 李怀栋


    采用双螺杆挤出机熔融挤出共混的方法,在较高螺杆转速条件下研究了CaCO3表面处理剂品种、CaCO3颗粒直径及其含量等因素对ABS/弹性体/CaCO3共混材料力学性能和加工流动性能的影响.结果表明,在CaCO3颗粒直径1.08~1.96 μm、C型表面处理剂、螺杆转速480r/min、220℃的共混条件下,可制得综合力学性能较好的ABS/高胶粉(GP)/CaCO3(质量比62.9∶17.1∶20)和ABS/EVA/CaCO3(质量比74.6∶20.4∶5)共混材料.%The effect of CaCO3 surface treated agents,CaCO3 particle diameter and content on mechanical properties and the melt flow rate of ABS/elastomer/CaCO3 blending material is investigated by means of melt extrusion and blending with twin-screw extruder.The results show that the blending materials with better mechanical properties such as ABS/GP/CaCO3 (mass ratio:62.9/17.1/20)and ABS/EVA/CaCO3 (mass ratio:74.6/20.4/5) can be obtained under the conditions of CaCO3 particle diameter 1.08-1.96 μm,screw rotation speed 480 r/min and extrusion temperature 220 ℃.

  10. Study on Surface Modification of Nano-CaCO3 and Its Application in PP%Nano-CaCO3的表面改性及其在PP中的应用

    崔文广; 高岩磊; 牟微; 雷霓


    选用钛酸酯偶联剂对纳米碳酸钙(nano-CaCO3)进行表面改性,以改善其在聚丙烯(PP)中的分散性.利用透射电镜(TEM)和扫描电镜(SEM)表征了nano-CaCO3的改性效果,研究了改性条件对PP/nano-CaCO3复合材料性能的影响.结果表明:在偶联剂用量2.0%、改性时间25 min、改性温度85℃的条件下,PP/nano-CaCO3复合材料的综合性能较好;改性后nano-CaCO3的分散性得到有效改善.%Nano-CaCO3 was modified by titanate coupling agent in order to improve its dispersion in PP. The modified effect of nano-CaCO3 was analyzed by TEM and SEM, and the effects of conditions of modification on property of PP/nano-CaCO3 composite were studied. The results show that the comprehensive properties of PP/nano-CaCO3 composite are optimal when nano-CaCO3 is modified by 2.0% coupling agent for 25 min at 85℃. The dispersion of modified nano-CaCO3 is better than that of unmodified nano-CaCO3.

  11. New synthetic route to Mg–Al–CO3 layered double hydroxide using magnesite

    Highlights: ► The use of magnesite to prepare Mg–Al–CO3 LDH is novel. ► The result sample is systematically studied. ► Furthermore, the cost of preparing Mg–Al–CO3 LDH may be reduced through this synthetic route. ► In the synthesis process, there is no CO2 released. That is significant to environmental protection. - Abstract: A novel synthesis of Mg–Al–CO3 layered double hydroxide (LDH) through chemical precipitation and hydrothermal methods has been investigated in this paper. The advantages of this method are using magnesite as magnesium source and no CO2 released in the process of preparation. Mg–Al–CO3 LDH (ZY) prepared under the optimized condition (the molar ratio of magnesite and Al(NO3)3·9H2O was 2.5:1; the aging time and temperature were 16 h and 100 °C, respectively) was characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), thermo-gravimetric and differential thermal analyser (TG–DTA) and scanning electron microscope (SEM). The crystal morphology of the prepared LDH displays platelet-like structure with a hexagonal shape, which is agreed with the LDH produced by industrial chemicals. Through elemental analysis and inductively coupled plasma-atomic emission spectrometry (ICP-AES), the chemical formula of ZY is determined as Mg0.70Al0.30(OH)2(CO3)0.15·0.6H2O

  12. Studies on Electrochemical Deposition and Characterization of Co3o4 Films

    P.N. Shelke


    Full Text Available The Co3O4 films are prepared using two steps method. Initially, the films are electrochemically deposited on stainless steel and copper substrates from the solution containing CoSO4 and H3BO3 at various molar concentrations (0.05, 0.09, 0.13, 0.17, 0.21, 0.25 and 0.28 M of CoCl2 in deposition bath. These as-deposited films are transformed into Co3O4 phase by heating them at 350 °C / 2 hr. These as-heated films are characterized by using X-ray diffraction, X-ray photoelectron spectroscopy, UV-Visible spectroscopy, Fourier transform infrared spectroscopy and scanning electron microscopy. From the characterization studies, the as-heated films are found to be containing single cubic spinel Co3O4 phase with high purity. The variation in molar concentration of CoCl2 in electrochemical deposition bath showed the profound effect on optical properties of Co3O4 films. The better optical properties, (i absorptance (α = 0.945, emittance (ε = 0.071 and (ii absorptance (α = 0.950, emittance (ε = 0.070 are obtained for the Co3O4 films prepared on stainless steel and copper substrates respectively at 0.28 M concentration of CoCl2 as compared to the data reported in literature. The strength and adhesion of as-heated films on both the substrates are found to be good for the molar concentrations of CoCl2 < 0.28 M.

  13. Promotional effects of samarium on Co3O4 spinel for CO and CH4 oxidation

    徐香兰; 韩红; 刘建军; 刘文明; 李文龙; 王翔


    A series of Co3O4 spinel catalysts modified by Sm were prepared by co-precipitation method and tested for CH4 and CO oxidation. The addition of a small amount of Sm into Co3O4 led to an improvement in the catalytic activity for both reactions. Co0.98Sm0.02 and Co0.95Sm0.05, the two samples with Co/Sm molar ratio of 0.98/0.02 and 0.95/0.05 in sequence, showed the similar and the highest activity for CH4 oxidation, with CH4 complete conversion at 450 ºC. In contrast, Co0.90Sm0.10 was the most active sample for CO oxidation, with CO complete conversion at 120 ºC. The catalysts were characterized by techniques of N2 adsor-tion-desorption with Brunauer-Emmett-Teller technique (N2-BET), X-ray powder diffraction (XRD), thermal gravity analy-sis-differential scanning calorimetry (TGA-DSC), H2 temperature programmed reduction (H2-TPR) and X-ray photoelectron spec-troscopy analysis (XPS). Compared with pure Co3O4, for Co1-xSmx catalysts with 0.02≤x≤0.10, the addition of a small amount of Sm resulted in the formation of spinel Co3O4 and amorphous SmCoO3, hence increasing the number of Co3+and the active surface oxygen species, which was responsible for the improvement of the activity. Co0.95Sm0.05 catalyst showed not only high thermal stability and activity but also good reaction durability in the presence of 5%water vapor for CH4 oxidation.

  14. 填料表面处理对ABS/CaCO3复合材料性能的影响%Influence of filler's surface treatment on mechanical and thermal properties of ABS/CaCO3 composites




  15. Study on Friction Reducing and Anti-wear of CaCO3 Nanoparticles as Additives in Lubricating Oils

    GU Zhou-ming; GU Cai-xiang; WANG Ren-bin


    This paper has insepected the size and the structure of the calcium carbonate (CaCO3) particles by adopting X-ray diffraction and transmission electron microscope (TEM). The suitable surfactants have been selected and put into lubricating oil with nanometer CaCO3 particles. By testing some parameters, such as the maximum non-seizure load, the shape and diameter of wear scar, the friction factor, the nanometer CaCO3 particles' properties of extreme pressure,anti-wear and friction reduction have been tested and analyzed. The properties of the nanometer CaCO3 particles' tribology chemistry have been analyzed through X-ray photoelectron spectrum (XPS) test. Also the nanometer CaCO3 particles'mechanism of anti-wear and friction reduction has been studied systematically. The research results show that, the lubricating oil with nanometer CaCO3 particles have good tribological properties.

  16. Study on Friction Reducing and Anti-wear of CaCO3 Nanoparticles as Additives in Lubricating Oils

    GUZhou-ming; GUCai-xiang; WANGRen-bin


    This paper has insepected the size mad the structure of the calcium carbonate (CaCO3) particles by adopting X-ray diffraction and transmission electron microscope (TEM). The suitable surfactants have been selected and put into lubricating oil with nanometer CaCO3 particles. By testing some parameters, such as the maximum non-seizure load, the shape and diameter of wear scar, the friction factor, the nanometer CaCO3 particles' properties of extreme pressure, anti-wear and friction reduction have been tested and analyzed. The properties of the nanometer CnCO3 particles' tribology chemistry have been analyzed through X-ray photoelectron spectrum (XPS) test. Also the nanometer CaCO3 particles' mechanism of anti-wear and friction reduction has been studied systematically. The research results show thai, the lubricating oil with nanometer CaCO3 particles have good tribological properties.


    Xuehua Chen; Chunzhong Li; Shoufang Xu; Ling Zhang; Wei Shao; H. L. Du


    Polymethyl methacrylate (PMMA)-coated nano-CaCO3 particles were prepared by in-situ emulsion polymerization. The mechanical properties of nano-CaCO3 particles-reinforced PVC were investigated using an AG-2000A universal testing machine and an XJU-2.75 izod impact tester; interfacial adhesion between CaCO3 nanoparticles and PVC matrix by SEM, and structure of PMMA coated on the surface of CaCO3 by FTIR and 1H-NMR. The results indicate that the PMMA coated on the nano CaCO3 particles consists mainly of syndiotactic structure, and their three tacticity contents were rr 52.8%, mm 7.3% and mr 39.9%, respectively. The interfacial adhesion between CaCO3 nanoparticles and PVC matrix was significantly improved when the CaCO3 nanoparticles were coated with PMMA, which led to increased Young's moduli and tensile strengths of the PMMA-coated CaCO3/PVC composites. The izod impact strengths of the composites were strongly affected by the PMMA coating thickness and increased significantly with increasing the volume fraction of CaCO3 filler in the composites.

  18. Effects of the Na2CO3 dopant on electron injection and transport in organic light emitting devices

    Na2CO3 is used as an n-type dopant to improve the electro-optical properties of tris(8-hydroxyquinoline)aluminum (Alq3)-based organic light-emitting diodes (OLEDs). Device properties such as the turn-on voltage, maximum luminance, and device efficiency were improved as Na2CO3 was doped. The higher mobility of Na2CO3-doped samples has been derived using space-charge-limited current measurements. Photoelectron spectroscopy results show that some electrons transfer from Na2CO3 into Alq3, which moves the Fermi level close to the lowest unoccupied molecular orbital of Alq3. Therefore, both the electron-transporting ability and electron-injection efficiency were enhanced, which improves the charge carrier balance in OLEDs and leads to better device efficiency. - Highlights: ► Na2CO3-doped OLEDs have improved opto-electrical properties. ► Na2CO3-doped Alq3 layers possess an enhanced electron injection ability. ► The higher mobility of the Na2CO3-doped samples derived by the SCLC model. ► The reaction between Na2CO3 and Alq3 results in an electron transfer process. ► The Na2CO3-doping moves the Fermi level close to the LUMO of Alq3

  19. Effect of magnesium addition on structural and magnetic properties of NiO, Co3O4 nanoparticles

    Magnesium added NiO and Co3O4 nanoparticles were prepared from microwave assisted method. The cubic phase natures of NiO, Co3O4 nanoparticles have been ascertained from X-ray diffraction. XRD pattern reveals the size of the particles was reduced to quantum level for NiO than Co3O4 due to the addition of magnesium ion. FTIR spectra have been performed to identify the vibration peaks of metal oxygen. Room temperature magnetic measurement ensures small ferromagnetic nature for Mg added NiO with higher saturation magnetization. superparamagnetic nature was examined for Mg added Co3O4 nanoparticles

  20. Neutron powder diffraction and magnetic studies of mesoporous Co3O4

    Samples of mesoporous Co3O4, created by using mesoporous silicas KIT-6 and SBA-16 as hard templates to control the growth of Co3O4 have been investigated with SQUID magnetometry and neutron powder diffraction, to reveal the effects of high surface area on the magnetic and electronic properties. DC magnetic susceptibility measurements show lower Neel ordering temperatures and lower magnetic moments than in a 'bulk' reference. A lower second transition temperature is also observed in the mesoporous samples, associated with the freezing of the surface (shell) magnetic moments. Measurements taken with increasing applied field at constant temperature show the materials to be antiferromagnetic as expected. Complementary parametric neutron powder diffraction studies show similar trends between the two mesoporous samples when looking at their Neel temperatures, and verify long range order within the samples.

  1. 51V-NMR study of the Kagome staircase compound Co3V2O8

    Kagome staircase compound Co3V2O8 (S = 3/2) has a structure very similar to multiferroic compound Ni3V2Og (S = 1), but their magnetic phase diagrams differ noticeably. We present the results of the first NMR study in Co3V2O8 single crystal. From 51V-NMR spectra, the components of electric field gradient (EFG) tensor and of magnetic shifts tensor, Ki, are obtained. The temperature dependences of NMR shifts 51Ki for each main crystal axis direction are well described by a spin contributions in the paramagnetic phase. In ferromagnetic phase the zero field 51V-NMR spectrum is observed in the temperature range of 1.5-6.3 K.

  2. Magnetic Properties of Nd8Fe83Co3B6 Nanocomposite Magnets


    The influence of quenching technology, annealing temperature and time on the structures and magnetic properties of Nd8Fe83Co3B6 nanocomposite magnets was investigated. The results show that the α-Fe/Nd2Fe14B nanocomposite magnet containing a small amount of B is difficult to form amorphous state. The magnetic properties of 26 m/s quenched Nd8Fe83Co3B6 powders annealed at 640℃×480 s reach iHc=513 kA/m, Br=1.05 T and (BH)max=92.0 kJ/m3. The grain size is Dα-Fe=21.5 nm and DNd2Fe14B=30.2 nm.

  3. Electric Field-Controlled Crystallizing CaCO3 Nanostructures from Solution.

    Qi, Jian Quan; Guo, Rui; Wang, Yu; Liu, Xuan Wen; Chan, Helen Lai Wah


    The role of electric field is investigated in determining the structure, morphology, and crystallographic characteristics of CaCO3 nanostructures crystallized from solution. It is found that the lattice structure and crystalline morphology of CaCO3 can be tailed by the electric field applied to the solution during its crystallization. The calcite structure with cubic-like morphology can be obtained generally without electric field, and the vaterite structure with the morphology of nanorod is formed under the high electric field. The vaterite nanorods can be piled up to the petaliform layers. Both the nanorod and the petaliform layer can have mesocrystal structures which are piled up by much fine units of the rods with the size of several nanometers. Beautiful rose-like nanoflowers can be self-arranged by the petaliform layers. These structures can have potential application as carrier for medicine to involve into metabolism of living cell. PMID:26932759

  4. Magnetization of the canted antiferromagnetic CoCO3 in Abragam-Pryce approximation

    Weiss molecular field theory was used to calculate the magnetization of the canted antiferromagnetic CoCO3 (TN=18.1K). Wave functions of magnetic doublets near Co2+ ground state in Abragam-Pryce approximation were determined. One of the crystal field variables, free Co2+ ion isotropic exchange interaction inside, and between magnetic sublatticies, and rotation angle φ, characterizing nonequivalence ion Co2+ positions, were used as parameters. From comparison with the experimental data exchange interaction anisotropy and g-factors g-bar , g-bar were obtained. At low temperatures T2+(1%)+CdCO3 single crystals. At high temperatures in the paramagnetic region, experimental data differs from calculated ones by more than two times. It is shown that this discrepancy cannot be described within the frames of used approximations

  5. Influence of Modified Nanosized CaCO3 on the Properties of Pigment Coated Paper%改性纳米CaCO3对涂布纸性能的影响

    唐艳军; 李友明; 薛国新



  6. Nano-CaCO3/HDPE复合材料流变性能的研究%Study on Rheological Behavior of Nano-CaCO3/HDPE Composites

    常杰云; 张帆


    通过熔融共混法制备了纳米碳酸钙/高密度聚乙烯( nano-CaCO3/HDPE)复合材料,使用旋转流变仪研究了复合材料的动态流变性能.结果表明,当nano-CaCO3加入量≤4%(质量分数)时,随着nano-CaCO3含量的增加,nano-CaCO3/HDPE复合材料的储能模量、损耗模量和复数黏度均高于纯HDPE,并逐渐上升.%By the method of melt blending, HDPE/nano-CaCO3composites were prepared and the dy-namic rheological properties were studied by rotational rheometer. The results indicated after nano-CaCO 3 was treated with silane coupling agent, with the increasing content ( ≤4% ) of namo-CaCO3, the storage modu-lus , loss modulus and complex viscosity were rising with the nano-CaCO3 content, and higher than that of pure HDPE.

  7. Co3O4/C nanocapsules with onion-like carbon shells as anode material for lithium ion batteries

    Graphical abstract: Co3O4 nanocapsules with the onion-like carbon shells were synthesized. As anode materials for lithium ion battery, the Co3O4 nanocapsules deliver an initial discharge capacity of 1467.6 mAh g−1 at 0.5 C and maintain a high reversible capacity of 1026.9 mAh g−1 after 50 cycles. -- Highlights: • Co3O4 nanocapsules with onion-like carbon shell have been synthesized. • Co3O4 nanocapsules deliver an initial discharge capacity of 1467.6 mAh g−1 at 0.5 C. • Co3O4 nanocapsules maintain a reversible capacity of 1026.9 mAh g−1 after 50 cycles. • Onion-like carbon shells can improve the electrochemical performance of Co3O4. -- Abstract: The synthesis and characterization of core/shell-type Co3O4/C nanocapsules for application as anode material in lithium ion batteries are reported in this paper. The synthesis process involves the preparation of Co/C nanocapsules using a modified arc-discharge method and the annealing of the Co/C nanocapsules at 300 °C for 2 h in air. The as-synthesized products show a spherical shape and a core/shell-type structure in which a Co3O4 nanoparticle core of diameter 10–30 nm is encapsulated by an onion-like carbon shell of thickness approximately 1 nm. The Co/C nanocapsules can be stable below 130 °C, and be oxidized above 205 °C in air. The Co3O4/C nanocapsules deliver an initial discharge capacity of 1467.6 mAh g−1 at 0.5 C and maintain a high reversible capacity of 1026.9 mAh g−1 after 50 charge–discharge cycles, much higher than the Co3O4 nanoparticles (471.5 mAh g−1). A postmortem analysis of the Co3O4 and Co3O4/C anodes subjected to prolonged cycling reveals the existence of a lower degree of surface cracking and particle breakage in the Co3O4/C anode than the Co3O4 anode. The improved electrochemical performance and structural stability in the Co3O4/C nanocapsules are attributed to the enhanced electrical conductivity and structural buffering provided by the onion-like carbon shell

  8. Heterogeneous microchemistry between CdSO4 and CaCO3 particles under humidity and liquid water

    Highlights: ► Raman analysis of chemical reactions between CdSO4 and CaCO3 particles. ► Under humid air no changes of morphology and chemical composition were observed. ► Condensation of liquid water generates an insoluble CdCO3 layer on CaCO3 surface. ► Addition of water previously equilibrated with CaCO3 generates CdCO3 and CaSO4. -- Abstract: Laboratory experiments using in situ Raman imaging combined with ex situ TOF-S-SIMS demonstrate the behavior of CdSO4·8/3H2O microparticles in contact with {101¯4} CaCO3 (calcite) surface under three different experimental conditions representative of unpolluted atmosphere. The contact of CdSO4·8/3H2O particles with CaCO3 surface in humid air (RH ∼ 40–80%) does not induce any chemical reaction. In contrast, the condensation of a water drop on CdSO4·8/3H2O/CaCO3 interface causes the free dissolution of CdSO4·8/3H2O particle in the drop. A CdSO4·8/3H2O microcrystal is reformed after gentle drying with a CdSO4·H2O coating of the CaCO3 surface. The TOF-S-SIMS image of the CaCO3 surface provides evidence of a thin layer corresponding probably to insoluble coating of CdCO3 (otavite) or CdxCa1−xCO3 solid solution at the liquid–solid interface. This layer armours the CaCO3 from further dissolution and stops the reaction. The deposition of CdSO4·8/3H2O particle in water drop previously in contact with CaCO3 for a long time generates CdCO3 small rhombohedral crystals while gentle drying provokes the crystallization of bar shape crystals of CaSO4·2H2O (gypsum). These laboratory results provide valuable chemical prediction for a possible fate of cadmium rich particles emitted in the atmosphere and thus, can contribute to realistic assessment of human exposure to Cd hazard

  9. CO2 assisted synthesis of highly dispersed Co3O4 nanoparticles on mesoporous carbon for lithium ion battery

    Graphical abstract: Co3O4 nanoparticles were uniformly dispersed onto the mesoporous carbon support (Co3O4/mC) using a facile process in CO2–expanded ethanol (CE) solution. Compared with Co3O4/mC-E synthesized in pure ethanol, the Co3O4/mC-CE exhibited better cycle performance which could be attributed to the synergistic effects between the superior structures of mesoporous C support and the highly dispersed Co3O4 nanoparticles. - Highlights: • Co3O4 nanoparticles were highly dispersed on mesoporous C in CE system. • The synthesis avoided the use of precipitants and aggregation of Co3O4 particles. • Co3O4/mC exhibited better cycle performance than the reference sample. • The synergistic effects of the mC and Co3O4 resulted in the improved performance. - Abstract: Co3O4 nanoparticles were uniformly dispersed onto the mesoporous carbon support (Co3O4/mC) using a facile process in CO2–expanded ethanol (CE) solution. During the synthesis, CO2 played the dual roles, one is to provide a simple physical expansion to evenly disperse the precursors onto the mesoporous carbon support, and the other is to offer some chemical groups such as CO32− to facilitate the complete and uniform deposition through the coordination to the metallic cations with these anions. When used as anode material for lithium ion batteries (LIBs), the Co3O4/mC synthesized in CO2-expanded ethanol solution exhibited larger surface area and better cycle performance compared with the reference sample synthesized in pure ethanol. The enhanced cycle performance could be attributed to the synergistic effects between the superior structures of mesoporous C support and the highly dispersed Co3O4 nanoparticles. More importantly, the synthesis of Co3O4/mC composite in CE solution was green and highly efficient, avoiding the use of precipitant and the aggregation of Co3O4, which would definitely enrich the strategies for the fabrication of carbon-based transition-metal oxide composites with great

  10. Insights into Reaction Mechanism of Na2CO3 in Foaming Process of Cullet Powder

    Petersen, Rasmus Rosenlund; König, Jakob; Smedskjær, Morten Mattrup;

    prior to glass melting, the resulting decomposition product Na2O has strong impact on the melt viscosity, phase separation and crystallisation behaviour, and also mechanical properties of the final glass. This is relatively well understood in literature. In contrast, when Na2CO3 is added as a foaming...... in the glass, making the studied cullet powder potentially suitable for producing insulation materials. Finally, we discuss these results based on supplementary x-ray diffraction and scanning electron microscopy analyses....

  11. Poly (3-Hydroxybutyrate-co-3-Hydroxyhexanoate)/Collagen Hybrid Scaffolds for Tissue Engineering Applications

    Lomas, Alex J.; Webb, William R.; Han, Jianfeng; Chen, Guo-Qiang; Sun, Xun; Zhang, Zhirong; Alicia J. El Haj; Forsyth, Nicholas R.


    The benefits associated with polyhydroxyalkanoates (PHA) in tissue engineering include high immunotolerance, low toxicity, and biodegradability. Poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx), a molecule from the PHA family of biopolymers, shares these features. In this study, the applicability of human embryonic stem cells (hESCs), spontaneously differentiated hESCs (SDhESCs), and mesenchymal stem cells (hMSCs) in conjunction with PHBHHx and collagen as a biocompatible replacement st...

  12. Crystallization of the CaCO3 mineral in the presence of the protein ovalbumin

    The kinetics of CaCO3 mineralization was studied by SANS in a 0.1 M aqueous CaCl2 solution in the presence of the protein ovalbumin found in chicken eggs. As the scattering from the protein and the mineral was observed within different Q regimes the evolution of the protein and mineral could be followed independently. It is observed that ovalbumin denaturates during the first 3 h and leads to a strong enhancement of mineralization

  13. Gas Permeability Properties of Poly(3-hydroxybutyrate-co-3-hydroxyhexanoate)

    Vandewijngaarden, Jens; Murariu, Marius; Dubois, Philippe; Carleer, Robert; Yperman, Jan; Adriaensens, Peter; Schreurs, Sonja; LEPOT, Nadia; Peeters, Roos; Buntinx, Mieke


    Environmental issues, such as the depletion of fossil resources and waste disposal, have instigated the development of poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx), a biobased and biodegradable polymer, bacterially produced from palm oil. PHBHHx is a versatile polymer and this study aims to further characterize it for the possible application as food packaging material. In this respect, barrier properties for gases such as O2, water vapor and CO2 are of great importance. PHBHHx film...

  14. Formation of Co3O4 Nanotubes and the Magnetic Behaviour at Low Temperature

    LI Tao; YANG Shao-Guang; HUANG Li-Sheng; GU Ben-Xi; DU You-Wei


    @@ Tubular Co3O4 nanostructures were prepared from cobalt nanowires embedded in an anodic alumina template.The morphologies of nanowires / nanotubes were studied by transmission electron microscopy, and x-ray diffraction was used in the analysis of the nanostructures and phases. A possible formation mechanism of the process from nanowires to nanotubes is discussed. The vibrating sample magnetometer measurements show anomalous magnetic behaviour of the cobalt oxide nanotubes at low temperature.

  15. High power Co3O4/ZnO p–n type piezoelectric transducer

    Enhancing the output power of piezoelectric transducer is essential in order to supply sufficient and sustainable power to wireless sensor nodes or electronic devices. In this work, a Co3O4/ZnO p–n type power piezoelectric transducer which can be operated at low frequencies has been developed by utilizing n-type semiconducting zinc oxide (ZnO) and p-type semiconducting tricobalt tetroxide (Co3O4). We utilize ZnO to be the piezoelectric transducer and build a multi-layer (Au/Co3O4/ZnO/Ti) thin film structure. The ZnO thin film with preferred orientation along the (002) plane was deposited under optimized deposition conditions on the flexible titanium (Ti) foil with thickness of 80 μm. The Co3O4/ZnO interface forms a p–n junction and increases the difference in Fermi levels between the two electrodes, resulting in the great enhancement of output power. The measured output power of the p–n type piezoelectric transducer with optimal resistance of 100 kΩ is 10.4 μW at low operating frequency of 37 Hz, which is 10.9 times of output power of ZnO piezoelectric transducers. - Highlights: • Deposited zinc oxide performed good piezoelectric coefficient. • ZnO thin film with preferred orientation along the (002) plane was deposited. • A p–n type piezoelectric transducer with enhanced output power was fabricated. • 10.9 times increment in output power was obtained. • Increase of difference in Fermi level and p–n junction formation was explained

  16. CuO and Co3O4 Nanoparticles: Synthesis, Characterizations, and Raman Spectroscopy

    Rashad, M.; Rüsing, M.; Berth, G.; Lischka, K.; Pawlis, A.


    Copper oxide and cobalt oxide (CuO, Co3O4) nanocrystals (NCs) have been successfully prepared in a short time using microwave irradiation without any postannealing treatment. Both kinds of nanocrystals (NCs) have been prepared using copper nitrate and cobalt nitrate as the starting materials and distilled water as the solvent. The resulted powders of nanocrystals (NCs) were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), an...

  17. Production of CaCO3/hyperbranched polyglycidol hybrid films using spray-coating technique.

    Malinova, Kalina; Gunesch, Manfred; Montero Pancera, Sabrina; Wengeler, Robert; Rieger, Bernhard; Volkmer, Dirk


    Biomineralizing organisms employ macromolecules and cellular processing strategies in order to produce highly complex composite materials such as nacre. Bionic approaches translating this knowledge into viable technical production schemes for a large-scale production of biomimetic hybrid materials have met with limited success so far. Investigations presented here thus focus on the production of CaCO(3)/polymer hybrid coatings that can be applied to huge surface areas via reactive spray-coating. Technical requirements for simplicity and cost efficiency include a straightforward one-pot synthesis of low molecular weight hyperbranched polyglycidols (polyethers of 2,3-epoxy-1-propanol) as a simple mimic of biological macromolecules. Polymers functionalized with phosphate monoester, sulfate or carboxylate groups provide a means of controlling CaCO(3) particle density and morphology in the final coatings. We employ reactive spray-coating techniques to generate CaCO(3)/hybrid coatings among which vaterite composites can be prepared in the presence of sulfate-containing hyperbranched polyglycidol. These coatings show high stability and remained unchanged for periods longer than 9 months. By employing carboxylate-based hyperbranched polyglycidol, it is possible to deposit vaterite-calcite composites, whereas phosphate-ester-based hyperbranched polyglycidol leads to calcite composites. Nanoindentation was used to study mechanical properties, showing that coatings thus obtained are slightly harder than pure calcite. PMID:22386308

  18. Rambutan-like FeCO3 hollow microspheres: facile preparation and superior lithium storage performances.

    Zhong, Yiren; Su, Liwei; Yang, Mei; Wei, Jinping; Zhou, Zhen


    Rambutan-like FeCO3 hollow microspheres were prepared via a facile and economic one-step hydrothermal method. The structure and morphology evolution mechanism was disclosed through time-dependent experiments. After undergoing the symmetric inside-out Ostwald ripening, the resultants formed microporous/nanoporous constructions composed of numerous one-dimensional (1D) nanofiber building blocks. Tested as anode materials of Li-ion batteries, FeCO3 hollow microspheres presented attractive electrochemical performances. The capacities were over 1000 mAh g(-1) for initial charge, ~880 mAh g(-1) after 100 cycles at 50 mA g(-1), and ~710 mAh g(-1) after 200 cycles at 200 mA g(-1). The 1D nanofiber assembly and hollow interior endow this material efficient contact with electrolyte, short Li(+) diffusion paths, and sufficient void spaces to accommodate large volume variation. The cost-efficient FeCO3 with rationally designed nanostructures is a promising anode candidate for Li-ion batteries. PMID:24066809

  19. A laboratory investigation of cyanobacterial extracellular polymeric secretions (EPS) in influencing CaCO 3 polymorphism

    Kawaguchi, T.; Decho, A. W.


    Bahamian stromatolites are well-laminated structures, consisting of lithified layers alternating between unlithified layers containing fine-grained carbonate ooids. The lithified layers consist of abundant aragonite needles embedded within a matrix of extracellular polymeric secretions (EPS) by cyanobacteria, Schizothrix sp. Laboratory investigations were conducted using EPS extracted from natural stromatolites and laboratory isolates of Schizothrix sp., to chemically characterize EPS, and determine in vitro how EPS may influence CaCO 3 polymorphism. EPS mainly consisted of acidic polysaccharides and proteins. Biochemical analyses indicated that contents of uronic acids and carbohydrates in EPS from lithified layers decreased when compared with unlithified layer EPS, while the protein content remained relatively constant. CaCO 3 nucleation experiments demonstrated that EPS from the lithified layer, induced aragonite crystal formation in vitro, as confirmed by scanning electron microscopy and Fourier transform infrared (FT-IR) spectroscopy. In contrast, EPS from the unlithified layer or laboratory-cultured Schizothrix sp. induced calcite crystal formation. These laboratory results suggest the possibility that the biochemical composition, specifically small proteins, of EPS influences the resulting mineralogy of CaCO 3.

  20. Effect of Li 2CO 3 additive on gas generation in lithium-ion batteries

    Shin, Jee-Sun; Han, Chi-Hwan; Jung, Un-Ho; Lee, Shung-Ik; Kim, Hyeong-Jin; Kim, Keon

    To elucidate the mechanism of gas generation during charge-discharge cycling of a lithium-ion cell, the generated gases and passive films on the carbon electrode are examined by means of gas chromatography (GC) and Fourier transform infrared (FTIR) spectroscopy. In ethyl carbonate/dimethyl carbonate and ethyl carbonate/diethyl carbonate 1 M LiPF 6 electrolytes, the detected gaseous products are CO 2, CO, CH 4, C 2H 4, C 2H 6, etc. The FTIR spectrum of the surface of the carbon electrode shows bands which correspond to Li 2CO 3, ROCO 2Li, (ROCO 2Li) 2, and RCO 2Li. These results suggest that gas evolution is caused by electrode decomposition, reactive trace impurities, and electrolyte reduction. The surface of the electrode is composed of electrolyte reduction products. When 0.05 M Li 2CO 3 is added as an electrolyte additive, the total volume of generated gases is reduced, and the discharge capacity and the conductivity of lithium-ions are increased. These results can be explained by a more compact and thin 'solid electrolyte interface' film on the carbon electrode formed by Li 2CO 3, which effectively prevents solvent co-intercalation and carbon exfoliation.

  1. Fabrication and Properties of Degradable PPC/ EVOH/ starch/ CaCO3 Composites

    QIAO Junjuan; DU Fengguang; PANG Maizhi; XIAO Min; WANG Shuanjin; MENG Yuezhong


    Thermally stable and biodegradable composites from poly (propylene carbonate) (PPC), poly (ethylene-co-vinyl alcohol) (EVOH), starch and CaCO3, were fabricated by melt blending. Differential scanning calorimetry (DSC), differential thermal analysis/ thermal gravimetric analysis (DTA/TGA), tensile test and scanning electron microscope (SEM) were performed to investigate the miscibility, thermal behavior and tensile properties of the PPC/ EVOH/ Starch/ CaCO3 composites. DSC results indicate that the introduction of EVOH could improve the compatibility between PPC and starch to some extent because of the interfacial interaction between PPC and EVOH, leading to an increase in tensile strength. The tensile strength began to decrease when more starch was added due to the aggregation of starch particles. SEM examination showed the good interfacial bonding between the fillers and polymeric components. The incorporation of both EVOH and fillers can greatly increase the thermal stability of PPC matrix. The PPC/ EVOH/ Starch/ CaCO3 composites can be melt processed and can be used as a common biodegradable material for a wide application.

  2. Effect of nano BaCO3 on pyrolytic reaction of phenol-formaldehyde resin

    Zhang, Xu; Ma, Qing-zhi; Zhang, Zhong-feng; Peng, Wan-xi; Zhang, Ming-long


    Phenol-formaldehyde resin is used as the most adhesive to produce waterproof plant-based composite. However, this product contains phenol and formaldehyde which can be easily released to pollute air and water. Based on the single-factor method, the effect of nano BaCO3 on situabtion of pyrolytic reaction of PF resin was studied by Py-GC/MS. There were components including carbon dioxide, D,.alpha.-tocopherol, 1,3-bis(trimethylsilyl) benzene, phenol from PF resin in 590(see manuscript) He gas. However, the 17 compounds including phenol, 2-methyl-, phenol, carbon dioxide, p-xylene, toluene, phenol, 2-ethyl-, phenol, 2,3-dimethyl-, benzene, 1,2,3-trimethyl-, etc were identified by Py-GC/MS after PF/BaCO3 composite was pyrolyzed in 590(see manuscript) He gas, and phenol and phenol derivants were found in the compounds. The result showed that nano BaCO3 could effectively delay the pyrolysis of PF resin.

  3. 12CO(3-2) Emission in Spiral Galaxies: Warm Molecular Gas in Action?

    Galaz, Gaspar; Bronfman, Leonardo; Rubio, Monica


    Using the APEX sub-millimeter telescope we have investigated the 12CO(3-2) emission in five face-on nearby barred spiral galaxies, where three of them are high surface brightness galaxies (HSBs) lying at the Freeman limit, and two are low surface brightness galaxies (LSBs). We have positive detections for two of three HSB spirals and non-detections for the LSBs. For the galaxies with positive detection (NGC0521 and PGC070519), the emission is confined to their bulges, with velocity dispersions of ~90 and ~73 km/s and integrated intensities of 1.20 and 0.76 K/km/s, respectively. For the non-detections, the estimated upper limit for the integrated intensity is ~0.54 K/km/s. With these figures we estimate the H2 masses as well as the atomic-to-molecular mass ratios. Although all the galaxies are barred, we observe 12CO(3-2) emission only for galaxies with prominent bars. We speculate that bars could dynamically favor the 12CO(3-2) emission, as a second parameter after surface brightness. Therefore, secular evolu...

  4. CuO and Co3O4 Nanoparticles: Synthesis, Characterizations, and Raman Spectroscopy

    M. Rashad


    Full Text Available Copper oxide and cobalt oxide (CuO, Co3O4 nanocrystals (NCs have been successfully prepared in a short time using microwave irradiation without any postannealing treatment. Both kinds of nanocrystals (NCs have been prepared using copper nitrate and cobalt nitrate as the starting materials and distilled water as the solvent. The resulted powders of nanocrystals (NCs were characterized by X-ray diffraction (XRD, transmission electron microscopy (TEM, scanning electron microscopy (SEM, and atomic force microscopy (AFM measurements. The obtained results confirm the presence of the both of oxides nanopowders produced during chemical precipitation using microwave irradiation. A strong emission under UV excitation is obtained from the prepared CuO and Co3O4 nanoparticles. The results show that the nanoparticles have high dispersion and narrow size distribution. The line scans of atomic force microscopy (AFM images of the nanocrystals (NCs sprayed on GaAs substrates confirm the results of both X-ray diffraction and transmission electron microscopy. Furthermore, vibrational studies have been carried out using Raman spectroscopic technique. Specific Raman peaks have been observed in the CuO and Co3O4 nanostructures, and the full width at half maximum (FWHM of the peaks indicates a small particle size of the nanocrystals.

  5. Phase transitions ordering–phase separation in the Co3V alloy

    Highlights: • Ordering–phase separation transition in the Co3V alloy occurs two times. • A tendency to phase separation takes place above 800 and below 450 °C. • Ordering with L12 phase formation occurs in the 450–800 °C interval. - Abstract: An electron microscopic study of the Co3V alloy microstructure formed after heat treatment at different temperatures has been conducted. Two phase transitions ordering–phase separation have been discovered, which occur in the alloy at temperatures of about 450 and 800 °C. At high-temperature phase separation, the microstructure consists of bcc vanadium atom particles and a fcc solid solution; at low-temperature phase separation, it is a cellular structure, in which the cellular boundaries are enriched in vanadium. In the region of ordering, it consists of particles of the Co3V chemical compound, randomly distributed in the solid solution. It is shown that at none of the temperatures do these microstructures correspond to those shown in the Co–V phase diagram.

  6. Synthesis of nano-CaCO3 composite particles and their application

    Wei Wu; Xueqin Zhang; Jianfeng Chen; Shuling Shen


    Nano-calcium carbonate composite particles were synthesized by the soapless emulsion polymerization technique of dou-ble monomers. The composite particles formation mechanism was investigated. The effects of composite particles on the mechanical properties of nano-CaCO3-ABS (acrylonitrile-butadiene-styrene copolymer) composite material were studied. It was validated that the composite particles are made up of the nano-calcium carbonate cores and the shells of alternating copolymers of butyl acrylate (BA) and styrene (St). The shells are chemically grafted and physically wrapped on the surface of nano-calcium carbonate particles.When the composite particles were filled in ABS matrix, the CaCO3 particles are homogeneously dispersed in the composite material as nanoscales. The impact strength of the composite material is obviously enhanced after idling appropriate amounts of composite particles. It can be concluded that the soapless emulsion polymerization of double monomers is an effective method for nano-CaCO3 surface treatment.

  7. Minicrystal and XPS Analysis of SiO2 coated superfine CaCO3 Powder%SiO2包覆超细CaCO3的微晶分析和XPS研究

    华益苗; 袁骏; 岳林海; 蔡菊香


    The superfine CaCO3 powder coated with SiO2 was synthesized. Through XRD technique, the cell parameters and crystallite size of reference and coated CaCO3 were calculated. SiO2 present in the state of amorphous and prevent the agglomeration and growth of CaCO3 micro-crystal. By comparing the result of XPS analysis of reference compound to coated sample, CaCO3 has been coated successfully with SiO2. The thickness of the coating is about 2.4~3.4nm. From the difference (0. BeV increase) of the binding energy of Ca2p, we presume that the bind Si-O-Ca has formed in the surface of CaCO3.

  8. Effects of Surface-treated CaCO3 on Polyurethane Sealant Characteristics%表面处理CaCO3对单组分聚氨酯密封剂性能的影响




  9. 改性纳米CaCO3/PVC复合材料的力学性能%Mechanical Properties of Modified Nano-CaCO3/PVC Composites



    采用钛酸酯偶联剂和PMMA 接枝方法改性纳米碳酸钙,并采用熔融共混法制备了改性纳米CaCO3增韧PVC( CaCO3/PVC)复合材料,研究了复合材料的力学性能.对比于未处理纳米CaCO3和钛酸酯偶联剂处理纳米CaCO3,PMMA接枝聚合改性纳米CaCO3与基体的相容性最好,增韧PVC复合材料的拉伸强度得到较大幅度提高.

  10. Sexual risk behaviour among people living with HIV according to the biomedical risk of transmission: results from the ANRS-VESPA2 survey

    Marie Suzan-Monti


    Full Text Available Introduction: People living with HIV (PLHIV on antiretroviral therapy (ART, with sustained undetectable viral load (sUVL and no history of sexually transmitted infections for at least six months, are considered to have a low risk of HIV transmission (LRT. We aimed to characterize, in a representative sample of French PLHIV, the sexual behaviour of LRT PLHIV compared with non-LRT PLHIV. Methods: The cross-sectional ANRS-VESPA2 survey was conducted on adult PLHIV attending French hospitals in 2011. The LRT PLHIV group included participants with sUVL and no sexually transmitted infection for at least 12 months. Socio-behavioural and medical data were collected. Chi-square tests helped compare sexual risk indicators between LRT and non-LRT PLHIV. The survey's retrospective nature allowed us to perform complementary category-based analyses of LRT PLHIV according to whether they had sUVL for at least 18, 24 or 36 months in three socio-epidemiological groups: men who have sex with men (MSM, other men and women. Results: Analysis included 2638 PLHIV diagnosed >12 months with available viral load data. The proportion of LRT PLHIV varied from 58% (≥12 months sUVL to 38% (≥36 months sUVL. Irrespective of sUVL duration, we found the following: 1 LRT men (MSM and other men were more likely to report having no sexual partner than their non-LRT counterparts. Among men having sexual partners in the previous 12 months, no significant difference was seen between LRT and non-LRT men in the number of sexual partners. LRT women were less likely to report having more than one sexual partner than non-LRT women; 2 LRT MSM were more likely to report being in sexually inactive couples than their non-LRT counterparts; 3 among sexually active participants, no difference was observed between LRT and non-LRT PLHIV concerning condom use with their serodiscordant steady partner or with their most recent casual sexual partners. Conclusions: LRT PLHIV with sUVL ≥12 months