WorldWideScience

Sample records for cement western countries

  1. Pigmentary disorders in Western countries

    NARCIS (Netherlands)

    van der Veen, J. P. Wietze

    2007-01-01

    Countries in the so-called "Western" world, especially in Europe, witnessed a dramatic change in ethnic backgrounds of their populations starting in the last decennia of the last century. This had repercussions on various aspects of our society, including medical practice. In dermatology for

  2. Peritoneal Dialysis in Western Countries.

    Science.gov (United States)

    Struijk, Dirk G

    2015-12-01

    better quality of life worldwide, but its prevalence is significantly lower than that of HD in all countries, with the exception of Hong Kong. Allowing reimbursement of PD but not HD has permitted to increase the use of PD over HD in many Asian countries like Hong Kong, Vietnam, Taiwan, Thailand, as well as in New Zealand and Australia over the last years. In the Western world, however, HD is still promoted, and the proportion of patients treated with PD decreases. Japan remains an exception in Asia where PD penetration is very low. Lack of adequate education of practitioners and information of patients might as well be reasons for the low penetration of PD in both the East and West. (2) Patient survival of PD varies between and within countries but is globally similar to HD. (3) Peritonitis remains the main cause of morbidity in PD patients. South Asian countries face specific issues such as high tuberculosis and mycobacterial infections, which are rare in developed Asian and Western countries. The infection rate is affected by climatic and socio-economic factors and is higher in hot, humid and rural areas. (4) Nevertheless, the promotion of a PD-first policy might be beneficial particularly for remote populations in emerging countries where the end-stage renal disease rate is increasing dramatically.

  3. Management of Membranous Nephropathy in Western Countries.

    Science.gov (United States)

    Alfaadhel, Talal; Cattran, Daniel

    2015-09-01

    Idiopathic membranous nephropathy (IMN) is a common cause of nephrotic syndrome (NS) in adults in Western countries. In 2012, the KDIGO (Kidney Disease: Improving Global Outcomes) working group published guidelines for the management of glomerulonephritis, thus providing a template for the treatment of this condition. While being aware of the impact of the clinicians' acumen and that patients may choose a different therapeutic option due to the risks of specific drugs and also of the evolving guidelines, this review details our approach to the management of patients with IMN in a Western center (Toronto). Based on studies published in Europe and North America, we included recent advances in the diagnosis and management of patients with membranous nephropathy similar to our practice population. We highlight the importance of establishing the idiopathic nature of this condition before initiating immunosuppressive therapy, which should include the screening for secondary causes, especially malignancy in the elderly population. The expected outcomes with and without treatment for patients with different risks of progression will be discussed to help guide clinicians in choosing the appropriate course of treatment. The role of conservative therapy as well as of established immunosuppressive treatment, such as the combination of cyclophosphamide and prednisone, and calcineurin inhibitors (CNIs), as well as of newer agents such as rituximab will be reviewed. Appropriate assessment is required to exclude secondary conditions causing membranous glomerulonephritis. The role of antibodies to phospholipase A2 receptor (anti-PLA2R) in establishing the primary disease is growing, though more data are required. The increase in therapeutic options supports treatment individualization, taking into account the availability, benefits and risks, as well as patient preference. (1) The prevalence of IMN is increasing worldwide, particularly in elderly patients, and has been reported in

  4. Solar Energy and the Western Asian Countries

    Science.gov (United States)

    De Morais Mendonca Teles, Antonio

    2016-07-01

    The Western Asian countries receive the most abundant solar radiation of the world. They also have enormous reserves of oil and natural gas. But the world reserves of those fuels will certainly diminish greatly as the worldwide demand for energy will increase steadily in the coming decades. And the suppliers of energy will have to contend with public concerns about the polluting effects of those fuels and the possible dangers of nuclear energy. Clearly a power source based on an non exhaustible and non-polluting fuel could be expected to find a role. It now appears that such a source is at hand in the solar energy. Here in this paper, under the principles in the United Nations' Agenda 21, we suggest to Western Asian countries, the study and own development of the following technologies based on solar energy; and comment about them: *photo-voltaic solar cell power plants - in the future, its cost per kilowatt-hour will probably be competitive as to other sources of electrical energy. A new technique, the solar non-imaging concentrator, with amorphous silicon-based thin films solar cells at the focus of the concentrators, can collect and intensify solar radiation far better than conventional concentrators do, thus reducing much more the cost; *bio-gas - using biological gas to produce energy and for heating/cooling purposes; *wind generation of electricity - it's nowadays, a non-expensive technique; *water pump for irrigation and human consuming, driving their power from photovoltaic cells; *and the study and own development of solar lasers for peaceful scientific studies. In this new kind of laser, the external necessary pumping energy comes from the high intensity of sunlight, produced with non-imaging concentrators. Solar lasers can give unexpected new great uses for mankind. Those achievements will require international cooperation and transfer of information, sustained research and development work, and some initial subsides by independent governments. Solar

  5. The behaviour of cemented backfill and the surrounding rockmass at western deep levels south mine

    CSIR Research Space (South Africa)

    York, G

    1992-11-01

    Full Text Available Cemented backfill is used at Western Deep Mine as local and regional support areas of high stopping width. The in situ performance is reported and compared to laboratory tests. A back analysis was carried out to obtain a more accurate value...

  6. Mathematics in middle schools in Western European countries

    NARCIS (Netherlands)

    Pelgrum, W.J.

    1988-01-01

    The International Association for the Evaluation of Educational Achievement has conducted a number of cross-national studies in which Western European countries participated. Results from the Second International Mathematics Study regarding the content and outcomes of this study in some Western

  7. A Hybrid Multidimensional Approach to Select a Country for Global Cement Plant Location

    Directory of Open Access Journals (Sweden)

    Muhammad Khurram Ali

    2015-04-01

    Full Text Available The globalization and saturated domestic markets force international firms to gradually expand their businesses across the borders to capture potential emerging markets. The decision to select a country for a new cement plant location demands analysis of a large number of factors. It is a multifaceted problem which requires investigation and prioritization of factors in a hierarchical way.This paper uses an FAHP (Fuzzy Analytic Hierarchy Process based procedure proposing a practical framework for solution of the GCPLP (Global Cement Plant Location Problem. It deals with real world ambiguities and handles a broader spectrum of influencing factors. The criteria for selection of a country for a new cement plant installation are prioritized from the FAHP based evaluation made by experts. Different global databases including the World Bank are used for the fuzzy ratings of the alternatives. It has been learnt in this particular problem that cement specific and cost related factors are the most sensitive while legal regulations and economic conditions are relatively less sensitive for the decision makers. Therefore, the countries having strong lime stone reserves, cheaper fuel costs and good internal marketing positions are higher in ranking. The paper concludes with different rankings of the four countries analyzed which assist the strategic managers in making decisions on the basis of mathematically computed results.

  8. A hybrid multidimensional approach to select a country for global cement plant location

    International Nuclear Information System (INIS)

    Ali, M.K.

    2015-01-01

    The globalization and saturated domestic markets force international firms to gradually expand their businesses across the borders to capture potential emerging markets. The decision to select a country for a new cement plant location demands analysis of a large number of factors. It is a multifaceted problem which requires investigation and prioritization of factors in a hierarchical way. This paper uses an FAHP (Fuzzy Analytic Hierarchy Process) based procedure proposing a practical framework for solution of the GCPLP (Global Cement Plant Location Problem). It deals with real world ambiguities and handles a broader spectrum of influencing factors. The criteria for selection of a country for a new cement plant installation are prioritized from the FAHP based evaluation made by experts. Different global databases including the World Bank are used for the fuzzy ratings of the alternatives. It has been learnt in this particular problem that cement specific and cost related factors are the most sensitive while legal regulations and economic conditions are relatively less sensitive for the decision makers. Therefore, the countries having strong lime stone reserves, cheaper fuel costs and good internal marketing positions are higher in ranking. The paper concludes with different rankings of the four countries analyzed which assist the strategic managers in making decisions on the basis of mathematically computed results. (author)

  9. WESTERN BALKANS’ COUNTRIES IN FOCUS OF GLOBAL ECONOMIC CRISIS

    OpenAIRE

    Engjell PERE; Albana HASHORVA

    2011-01-01

    The paper intends to analyze the impact of global economic crisis on the economies of Western Balkan Region. Albania, Bosnia & Herzegovina, Croatia, Macedonia (FYROM), Montenegro, Serbia, and Kosovo are part of this Region. The purpose of the paper is not to analyze the global crisis impact on specific sectors of the economies of the Western Balkan Countries, indeed, it focuses mainly on the macroeconomic level, identifying and analyzing fluctuations of major macroeconomic indicators of the e...

  10. The Development of Green Care in Western European Countries

    NARCIS (Netherlands)

    Haubenhofer, D.K.; Elings, M.; Hassink, J.; Hine, R.E.

    2010-01-01

    This article represents a review of green care across Western European countries. The following questions are addressed: What is green care, and what are its basic goals? What are the most commonly known types of green care interventions, and how are they connected to each other? There are different

  11. Monitoring of agricultural policy developments in the Western Balkan countries

    OpenAIRE

    VOLK TINA; REDNAK MIROSLAV; ERJAVEC EMIL; ZHLLIMA EDVIN; GJECI GRIGOR; BAJRAMOVIĆ SABAHUDIN; VAŠKO ŽELJKO; OGNJENOVIĆ DRAGANA; BUTKOVIĆ JAKUB; KEROLLI-MUSTAFA MIHONE; GJOKAJ EKREM; HOXHA BEKIM; DIMITRIEVSKI DRAGI; KOTEVSKA ANA; STAMENKOVSKA IVANA JANESKA

    2017-01-01

    This reports provides the analysis of the monitoring of agricultural policy in the Western Balkans (WB) countries. This reports attempts to show (i) the main development patterns in production and trade in WB; (ii) an overview of the new policy framework (new programming documents from the period 2013-2015) and its implementation; (iii) the scope and structure of budgetary transfers to agriculture in regional comparison and also in terms of approximation with the CAP; and (iv) the main charac...

  12. Business regulation and economic growth in the Western Balkan countries

    Directory of Open Access Journals (Sweden)

    Engjell PERE

    2013-06-01

    Full Text Available Actually economic policies in many countries aimed to stimulate their economic growth, particularly after negative impact of the global economic crisis. In this regards, fiscal regulation are an important aspect of those policies, that can promote or obstacle the economic growth in general. In this point of view this paper aims to analyze the system of administration rules in different Western Balkans Countries, (which includes Albania, Bosnia & Herzegovina, Croatia, Kosovo, Macedonia (FYROM, Montenegro and Serbia. Moreover, a special attention is given investigation of the regulation and administrative facilitation aspects of doing business in the above-mentioned countries, whether this system stimulates, or not, the development of private business and economic growth.The paper is divided into three main sections. The first part provides a retrospective of economic growth in the Western Balkan countries and the dependence of this growth on global economic development. The second part proceeds with the investigations of the impact of administrative regulation on economic growth. The third part, based on an econometric model, will analyze the correlation between economic growth and elaborated indicators which present the level of business administrative regulation system. Furthermore, this last section discusses the results and concludes. In this analysis, the paper is based substantially on the data base of "Doing Business 2013" (World Bank.

  13. Bringing Western-standard service stations to the Baltic countries

    International Nuclear Information System (INIS)

    Pesonen, H.

    1992-01-01

    Neste is the only Western oil company so far to have established a service station presence in the Baltic, with the exception of Norway's Statoil, which has one outlet near Tallinn Airport. Neste has an important logistical advantage compared to other companies in this respect as its two Finnish refineries are ideally located for supplying the region with high-quality petroleum products. Neste's first joint venture in the Baltic, Traffic Service, based in Estonia, was set up with Eesti Kutus in 1988 and opened its first service station in 1990. Other joint ventures are now up and running in Latvia, Lithuania, Poland, and St. Petersburg. A total of 10 - 15 stations, the majority strategically located along the route of the Via Baltica, are expected to be operational by the end of this year. The Neste network comprises a combination of new outlets and refurbished older stations that have been modernized to bring them up to Western standards. These offer a comprehensive range of fuels, lubricants, spare parts, and accessories, as well as food, confectionery, and coffee shop services. Some stations also offer repair and car wash facilities. Adapting to the transition from a communist economy to a Western, capitalist one has not been easy for the Baltic countries, and has inevitably created difficulties for companies like Neste, in areas such as legislation covering land ownership. Neste's joint ventures have also encountered difficulties in instilling the Western approach to business efficiency, and customer service in a workforce used to the Soviet retail system

  14. Factors affecting the use of prenatal care by non-western women in industrialized western countries: a systematic review.

    OpenAIRE

    Boerleider, A.W.; Wiegers, T.A.; Manniën, J.; Francke, A.L.; Devillé, W.L.J.M.

    2013-01-01

    Background: Despite the potential of prenatal care for addressing many pregnancy complications and concurrent health problems, non-western women in industrialized western countries more often make inadequate use of prenatal care than women from the majority population do. This study aimed to give a systematic review of factors affecting non-western women's use of prenatal care (both medical care and prenatal classes) in industrialized western countries.Methods: Eleven databases (PubMed, Embas...

  15. [Gnathostomosis, an exotic disease increasingly imported into Western countries].

    Science.gov (United States)

    Clément-Rigolet, Marina C; Danis, Martin; Caumes, Eric

    2004-12-04

    AN INCIDENTAL HELMITHIASIS IN MAN: Gnathostomiasis is an helminthic disease of animals due to a nematode belonging to the gender Gnathostoma. This gender includes many species, the most frequent being Gnathostoma spinigerum. Man is an incidental host. Human gnathostomiasis is endemic in some countries of South-East Asia, and Latin America. It is due to the consumption of raw or insufficiently cooked meat or fish. Since the beginning of the eighties, there is an increasing number of cases of gnathostomiasis described in Western countries in travellers returning from endemic countries. IN THE SKIN OR THE VISCERA: Gnathostomiasis is a cause of cutaneous and/or visceral larva migrans syndrome. Some visceral involvement, more particularly neurological forms, may lead to significant morbidity and mortality. The diagnosis is occasionally confirmed by the identification of the Gnathostoma larva in the skin or viscera. Most often the diagnosis relies on epidemiological, clinical and biological (hypereosinophilia, positive serologic test) grounds. ALBENDAZOLE AND IVERMECTINE: The first line treatment is albendazole, 400 mg once or twice a day during 21 days. The efficacy of ivermectin needs to be assessed more precisely. Relapses may occur up to 24 months after apparent cure.

  16. Understanding the motives for food choice in Western Balkan Countries.

    Science.gov (United States)

    Milošević, Jasna; Žeželj, Iris; Gorton, Matthew; Barjolle, Dominique

    2012-02-01

    Substantial empirical evidence exists regarding the importance of different factors underlying food choice in Western Europe. However, research results on eating habits and food choice in the Western Balkan Countries (WBCs) remain scarce. A Food Choice Questionnaire (FCQ), an instrument that measures the reported importance of nine factors underlying food choice, was administered to a representative sample of 3085 adult respondents in six WBCs. The most important factors reported are sensory appeal, purchase convenience, and health and natural content; the least important are ethical concern and familiarity. The ranking of food choice motives across WBCs was strikingly similar. Factor analysis revealed eight factors compared to nine in the original FCQ model: health and natural content scales loaded onto one factor as did familiarity and ethical concern; the convenience scale items generated two factors, one related to purchase convenience and the other to preparation convenience. Groups of consumers with similar motivational profiles were identified using cluster analysis. Each cluster has distinct food purchasing behavior and socio-economic characteristics, for which appropriate public health communication messages can be drawn. Copyright © 2011 Elsevier Ltd. All rights reserved.

  17. Mapping Asbestos-Cement Roofing with Hyperspectral Remote Sensing over a Large Mountain Region of the Italian Western Alps

    Directory of Open Access Journals (Sweden)

    Federico Frassy

    2014-08-01

    Full Text Available The World Health Organization estimates that 100 thousand people in the world die every year from asbestos-related cancers and more than 300 thousand European citizens are expected to die from asbestos-related mesothelioma by 2030. Both the European and the Italian legislations have banned the manufacture, importation, processing and distribution in commerce of asbestos-containing products and have recommended action plans for the safe removal of asbestos from public and private buildings. This paper describes the quantitative mapping of asbestos-cement covers over a large mountainous region of Italian Western Alps using the Multispectral Infrared and Visible Imaging Spectrometer sensor. A very large data set made up of 61 airborne transect strips covering 3263 km2 were processed to support the identification of buildings with asbestos-cement roofing, promoted by the Valle d’Aosta Autonomous Region with the support of the Regional Environmental Protection Agency. Results showed an overall mapping accuracy of 80%, in terms of asbestos-cement surface detected. The influence of topography on the classification’s accuracy suggested that even in high relief landscapes, the spatial resolution of data is the major source of errors and the smaller asbestos-cement covers were not detected or misclassified.

  18. Perceived impact of socially anxious behaviours on individuals’ lives in Western and East Asian countries

    NARCIS (Netherlands)

    Rapee, R.M.; Kim, J.; Wang, J.; Liu, X.; Hofmann, S.G.; Chen, J.; Oh, K.Y.; Bögels, S.M.; Arman, S.; Heinrichs, N.; Alden, L.E.

    2011-01-01

    The current study compared the predicted social and career impact of socially withdrawn and reticent behaviors among participants from Western and East Asian countries. Three hundred sixty-one college students from 5 Western countries and 455 students from 3 East Asian countries read hypothetical

  19. Analysis of prospects for advanced nuclear reactors in western countries

    Energy Technology Data Exchange (ETDEWEB)

    Di Sapia, R. [ENEA, Rome (Italy). Area Energetica; Foskolos, K. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1994-05-01

    Nuclear energy deployment faces stagnation in western european and north american countries as a result of barriers that have appeared over the years. Such barriers were identified in the domains of economics, public acceptance, energy policy, technology, licensing and regulations as well as environment and waste disposal. It is to the nuclear community and particularly the industry to take the initiative and the leadership role for the most significant approaches to overcome these barriers. These approaches include concetration of efforts, lowering of costs and financial risks and extensive use of the experience accumulated so far; clear setting of priorities and long-term global consideration of the energy issue; encouraging an appropriate, stable regulatory environment and harmonisation of general safety objectives and principles, and adequate, globally consistent and clear information to the public. Also within the prime responsability of the nuclear community belong the safe operation of existing plants; making available all necessary information to the public, the media and the political leaders, supporting the development and execution of national energy polcies; supporting authorities in improving regulatory processes; taking all measures to improve economics of nuclear power; pursuing plans for the safe disposal of radioactive wastes. Governments should place energy issues in the appropriate priority level and encourage the establishment of an equally favourable environment for nuclear energy, including a greater consensus among controversial opinion representatives. Finally, authorities should established reasonable, transparent and predictable regulatory enviroments. This paper describes the barriers in a systematic way and proposes appropriate measures to overcame them.

  20. Analysis of prospects for advanced nuclear reactors in western countries

    International Nuclear Information System (INIS)

    Di Sapia, R.

    1994-01-01

    Nuclear energy deployment faces stagnation in western european and north american countries as a result of barriers that have appeared over the years. Such barriers were identified in the domains of economics, public acceptance, energy policy, technology, licensing and regulations as well as environment and waste disposal. It is to the nuclear community and particularly the industry to take the initiative and the leadership role for the most significant approaches to overcome these barriers. These approaches include concentration of efforts, lowering of costs and financial risks and extensive use of the experience accumulated so far; clear setting of priorities and long-term global consideration of the energy issue; encouraging an appropriate, stable regulatory environment and harmonization of general safety objectives and principles, and adequate, globally consistent and clear information to the public. Also within the prime responsibility of the nuclear community belong the safe operation of existing plants; making available all necessary information to the public, the media and the political leaders, supporting the development and execution of national energy policies; supporting authorities in improving regulatory processes; taking all measures to improve economics of nuclear power; pursuing plans for the safe disposal of radioactive wastes. Governments should place energy issues in the appropriate priority level and encourage the establishment of an equally favourable environment for nuclear energy, including a greater consensus among controversial opinion representatives. Finally, authorities should established reasonable, transparent and predictable regulatory enviroments. This paper describes the barriers in a systematic way and proposes appropriate measures to overcame them

  1. Bespilotne letelice zapadnih zemalja / Unmanned aircraft of Western countries

    Directory of Open Access Journals (Sweden)

    Slavko Pokorni

    2002-11-01

    Full Text Available Trend sve češće primene bespilotnih letelica biće nastavljen nesumnjivo, i tokom ove decenije. U vezi s tim stiče se utisak da će razvoj borbenih bespilotnih letilica biti u usponu. Mada je u proteklom periodu težište bilo na razvoju bespilotnih letilica za vojne primene (gde su ulagana velika sredstva, a civilni sektor je, uglavnom, koristio rezultate razvoja vojnih bespilotnih letelica, u narednom periodu se očekuje porast ulaganja i u razvoj bespilotnih letelica u civilnom sektoru. Bespilotne letelice su imale značajnu ulogu u zadacima koje su obavljale multinacionalne snage u toku rata u Bosni i Hercegovini i agresije NATO-a na SRJ, pa je poznavanje karakteristika bespilotnih letelica, za pripadnike Vojske, od velikog značaja. U sažetom tabelarnom pregledu prikazani su podatci o bespilotnim letelicama uglavnom proizvođača iz zapadnih zemalja, što ne znači da ih ne proizvode i druge zemlje, posebno Ruska federacija kao i neke susedne zemlje (Bugarska, Hrvatska. / The increasingly frequent use of unmanned aircraft will continue unabated throughout this decade. About that the impression is that the development of combat drones will rise. Although in the past period the focus was on the development of unmanned military vehicles (where large funds were invested, and the civil sector used mainly the development of military drones, in the coming period, investment in the development of unmanned aircraft in the civil sector is expected . Unmanned aircraft played a significant role in the tasks performed by multinational forces during the war in Bosnia and Herzegovina and NATO aggression in the FR Yugoslavia, so the knowledge of the characteristics of drones for members of the Army is of great importance. The summary table shows the data on unmanned aircraft mainly manufactured from Western countries, which does not mean that they are not produced by other countries, especially the Russian Federation as well as some neighboring

  2. Factors affecting the use of prenatal care by non-western women in industrialized western countries: a systematic review

    NARCIS (Netherlands)

    Boerleider, A.W.; Wiegers, T.A.; Manniën, J.; Francke, A.L.; Devillé, W.L.J.M.

    2013-01-01

    Background Despite the potential of prenatal care for addressing many pregnancy complications and concurrent health problems, non-western women in industrialized western countries more often make inadequate use of prenatal care than women from the majority population do. This study aimed to give a

  3. Factors affecting the use of prenatal care by non-western women in industrialized western countries: a systematic review.

    NARCIS (Netherlands)

    Boerleider, A.W.; Wiegers, T.A.; Manniën, J.; Francke, A.L.; Devillé, W.L.J.M.

    2013-01-01

    Background: Despite the potential of prenatal care for addressing many pregnancy complications and concurrent health problems, non-western women in industrialized western countries more often make inadequate use of prenatal care than women from the majority population do. This study aimed to give a

  4. Factors affecting the use of prenatal care by non-western women in industrialized western countries: a systematic review

    NARCIS (Netherlands)

    Boerleider, A.W.; Wiegers, T.A.; Manniën, J.; Francke, A.L.; Deville, W.L.J.M.

    2013-01-01

    Background: Despite the potential of prenatal care for addressing many pregnancy complications and concurrent health problems, non-western women in industrialized western countries more often make inadequate use of prenatal care than women from the majority population do. This study aimed to give a

  5. The Prevalence and Management of Systemic Amyloidosis in Western Countries.

    Science.gov (United States)

    Nienhuis, Hans L A; Bijzet, Johan; Hazenberg, Bouke P C

    2016-04-01

    , evidence of systemic deposition, reliable typing, precursor assessment, severity of organ disease, risk assessment and prognosis, choice of treatment, and planned monitoring during follow-up. (1) AL amyloidosis is the most prevalent type of amyloidosis accounting for 65% of the amyloidosis-diagnosed patients in the UK and for 93% of the amyloidosis-diagnosed patients in China. The predisposition of men over women to develop AL amyloidosis might be higher in China than in Western countries (2:1 vs. 1.3:1). Both in the East and West, incidence increases with age. At the time of diagnosis, edema is twice as frequent and the proportion of renal involvement is higher in Chinese compared to Western patients. (2) Melphalan followed by autologous stem cell transplantation (ASCT) is the current standard therapy but is restricted to eligible patients. The efficacy and safety of bortezomib combined with dexamethasone were proven in Western patients and recently confirmed in a Chinese cohort. Recent studies in China and the US indicate that bortezomib induction prior to ASCT increases the response rate. Thalidomide and lenalidomide have shown benefit, but toxicity and lack of clinical evidence exclude these agents from first-line therapy. The green tea extract epigallocatechin-3-gallate is under investigation as an inhibitor of AL amyloid formation and a compound that might dissolve amyloid.

  6. Perceived impact of socially anxious behaviors on individuals' lives in Western and East Asian countries.

    Science.gov (United States)

    Rapee, Ronald M; Kim, Jinkwan; Wang, Jianping; Liu, Xinghua; Hofmann, Stefan G; Chen, Junwen; Oh, Kyung Ya; Bögels, Susan M; Arman, Soroor; Heinrichs, Nina; Alden, Lynn E

    2011-09-01

    The current study compared the predicted social and career impact of socially withdrawn and reticent behaviors among participants from Western and East Asian countries. Three hundred sixty-one college students from 5 Western countries and 455 students from 3 East Asian countries read hypothetical vignettes describing socially withdrawn and shy behaviors versus socially outgoing and confident behaviors. Participants then answered questions following each vignette indicating the extent to which they would expect the subject of the vignette to be socially liked and to succeed in their career. Participants also completed measures of their own social anxiety and quality of life. The results indicated significant vignette-by-country interactions in that the difference in perceived social and career impact between shy and outgoing vignettes was smaller among participants from East Asian countries than from Western countries. In addition, significant negative correlations were shown between personal level of shyness and experienced quality of life for participants from both groups of countries, but the size of this relationship was greater for participants from Western than East Asian countries. The results point to the more negative impact of withdrawn and socially reticent behaviors for people from Western countries relative to those from East Asia. Copyright © 2011. Published by Elsevier Ltd.

  7. Effects of capital markets development on economic growth of Western Balkan countries

    Directory of Open Access Journals (Sweden)

    MSc. Artor Nuhiu

    2011-12-01

    Full Text Available Through this research paper we have tried to elaborate the issue whether capital market development is an alternative towards economic growth and economic prosperity of developing countries in general, the Western Balkan countries in particular. The focus of the paper is to study the effects of proper functioning of capital markets and their im-pact on increasing the level of savings, capital investments and in locating relevant resources for long-term financing of the economy. The research paper presents positive and negative arguments, linking the establishment and development of a capital market and its impact on economic development of developing countries, particularly Western Balkan countries.

  8. Factors affecting the use of prenatal and postnatal care by women of non-western immigrant origin in industrialized western countries.

    NARCIS (Netherlands)

    Boerleider, A.W.; Devillé, W.L.J.M.; Francke, A.L.; Wiegers, T.A.

    2011-01-01

    Background: In many industrialized western countries immigrants constitute a substantial part of the population, which is also seen in the prenatal and postnatal care client population. Research in several industrialized western countries has shown that women of non-western immigrant origin make

  9. Gender Inequalities in the Education of the Second Generation in Western Countries

    Science.gov (United States)

    Fleischmann, Fenella; Kristen, Cornelia

    2014-01-01

    Drawing on comparative analyses from nine Western countries, we ask whether local-born children from a wide range of immigrant groups show patterns of female advantage in education that are similar to those prevalent in their host Western societies. We consider five outcomes throughout the educational career: test scores or grades at age 15,…

  10. Analysis of the agricultural and rural development policies of the Western Balkan countries

    OpenAIRE

    BAJRAMOVIĆ Sabahudin; BOGDANOV Natalija; BUTKOVIĆ Jakub; DIMITROVSKI Dragi; ERJAVEC Emil; GJECI Grigor; GJOKAJ Ekrem; HOXHA Bekim; STOMENKOVSKA Ivana Janeska; KONJEVIĆ Darko; KOTEVSKA Ana; MARTINOVIĆ Aleksandra; MIFTARI Iliriana; NACKA Marina; OGNJENOVIĆ Dragana

    2016-01-01

    This report was prepared by a team of academic experts from Western Balkan (WB) countries coordinated by the Regional Rural Development Standing Working Group (SWG) in South-East Europe. The study targets EU candidate and potential candidate countries from the Western Balkan region (Albania, Bosnia and Herzegovina, Macedonia, Montenegro, Serbia and Kosovo*). The main objectives of the study is the monitoring and evaluation of agricultural policies in the period 2012-2014 and assessment of the...

  11. Factors affecting the use of prenatal care by non-western women in industrialized western countries: a systematic review

    Science.gov (United States)

    2013-01-01

    Background Despite the potential of prenatal care for addressing many pregnancy complications and concurrent health problems, non-western women in industrialized western countries more often make inadequate use of prenatal care than women from the majority population do. This study aimed to give a systematic review of factors affecting non-western women’s use of prenatal care (both medical care and prenatal classes) in industrialized western countries. Methods Eleven databases (PubMed, Embase, PsycINFO, Cochrane, Sociological Abstracts, Web of Science, Women’s Studies International, MIDIRS, CINAHL, Scopus and the NIVEL catalogue) were searched for relevant peer-reviewed articles from between 1995 and July 2012. Qualitative as well as quantitative studies were included. Quality was assessed using the Mixed Methods Appraisal Tool. Factors identified were classified as impeding or facilitating, and categorized according to a conceptual framework, an elaborated version of Andersen’s healthcare utilization model. Results Sixteen articles provided relevant factors that were all categorized. A number of factors (migration, culture, position in host country, social network, expertise of the care provider and personal treatment and communication) were found to include both facilitating and impeding factors for non-western women’s utilization of prenatal care. The category demographic, genetic and pregnancy characteristics and the category accessibility of care only included impeding factors. Lack of knowledge of the western healthcare system and poor language proficiency were the most frequently reported impeding factors. Provision of information and care in women’s native languages was the most frequently reported facilitating factor. Conclusion The factors found in this review provide specific indications for identifying non-western women who are at risk of not using prenatal care adequately and for developing interventions and appropriate policy aimed at

  12. Factors affecting the use of prenatal care by non-western women in industrialized western countries: a systematic review.

    Science.gov (United States)

    Boerleider, Agatha W; Wiegers, Therese A; Manniën, Judith; Francke, Anneke L; Devillé, Walter L J M

    2013-03-27

    Despite the potential of prenatal care for addressing many pregnancy complications and concurrent health problems, non-western women in industrialized western countries more often make inadequate use of prenatal care than women from the majority population do. This study aimed to give a systematic review of factors affecting non-western women's use of prenatal care (both medical care and prenatal classes) in industrialized western countries. Eleven databases (PubMed, Embase, PsycINFO, Cochrane, Sociological Abstracts, Web of Science, Women's Studies International, MIDIRS, CINAHL, Scopus and the NIVEL catalogue) were searched for relevant peer-reviewed articles from between 1995 and July 2012. Qualitative as well as quantitative studies were included. Quality was assessed using the Mixed Methods Appraisal Tool. Factors identified were classified as impeding or facilitating, and categorized according to a conceptual framework, an elaborated version of Andersen's healthcare utilization model. Sixteen articles provided relevant factors that were all categorized. A number of factors (migration, culture, position in host country, social network, expertise of the care provider and personal treatment and communication) were found to include both facilitating and impeding factors for non-western women's utilization of prenatal care. The category demographic, genetic and pregnancy characteristics and the category accessibility of care only included impeding factors.Lack of knowledge of the western healthcare system and poor language proficiency were the most frequently reported impeding factors. Provision of information and care in women's native languages was the most frequently reported facilitating factor. The factors found in this review provide specific indications for identifying non-western women who are at risk of not using prenatal care adequately and for developing interventions and appropriate policy aimed at improving their prenatal care utilization.

  13. Knowledge economy readiness, innovativeness and competitiveness of the Western Balkan countries

    Directory of Open Access Journals (Sweden)

    Cvetanović Slobodan

    2015-01-01

    Full Text Available The Western Balkan countries have set themselves the goal to join the European Union as soon as possible. Accordingly, they must adjust the key components of their development policies to the Europe 2020 strategy, focusing on key priorities such as smart, sustainable and inclusive growth. This paper explores the relationship among knowledge economy readiness, innovativeness, and competitiveness of six Western Balkan countries (Albania, Bosnia and Herzegovina, Macedonia, Serbia, Croatia, and Montenegro and the group of six selected neighboring EU countries (Austria, Bulgaria, Greece, Hungary, Romania, and Slovenia. The paper relies on the data obtained from the Knowledge Economy Index of the World Bank Institute, INSEAD's Global Innovation Index and the Global Competitiveness Index of the World Economic Forum for 2013. Obtained data from all three sources indicated significantly lower readiness for the development of economy based on knowledge, innovation and competitiveness in the Western Balkans countries in comparison to the selected EU countries. The analysis of the interdependence of the aforementioned variables points to: a statistically significant correlation between the indicator knowledge economy index and the global innovation index for both groups of countries; b statistically significant linear correlation between innovativeness and innovation efficiency ratio for the Western Balkan countries. Conversely, no respective correlation has been registered for the group of selected EU countries; c no statistically significant correlation between the global innovation index and the global competitiveness index in the Western Balkan countries, while in respect of the group of selected EU countries, the existence of significant linear correlation between these variables has been revealed.

  14. Broadband adoption, digital divide, and the global economic competitiveness of Western Balkan countries

    Directory of Open Access Journals (Sweden)

    Mitrović Đorđe

    2015-01-01

    Full Text Available The existing variation in economic performance between countries is significantly affected by the level, diffusion, and use of different types of information and communication technology. In the last several years economic competitiveness increasingly depends on broadband availability and the adoption, use, and speed of this technology. Broadband access to the internet fosters economic growth and development and increases a country’s global competitiveness. This technology could have a big impact on the competitive advantage of Western Balkan countries because they currently experience a large digital divide, both within countries (between regions, urban and rural areas, different vulnerable groups, etc. and with EU countries. The purpose of the paper is to analyse the current level and dynamics of the digital divide in Western Balkan countries using the Broadband Achievement Index (BAI, the Data Envelopment Analysis (DEA-based model, the Global Competitiveness Index (GCI, the Corruption Perception Index (CPI, and cross-country methodology. This paper measures and compares Western Balkan countries’ current level of broadband adoption and their position on the evolutionary path towards closing the existing economic and digital gap with EU countries. Comparative analysis of calculated BAI data values, GCI, and CPI shows that Western Balkan countries belong to the ‘laggard’ group regarding their broadband achievement and global economic competitiveness. The values of the calculated BAI sub-indexes in this paper indicate the strong and weak sides of the corresponding aspects of broadband technology implementation and give directions for setting further priorities for political intervention, not only in the building of information society but also in the improvement of the economic competitiveness of Western Balkan countries.

  15. Performances of hydrated cement treated crushed rock base for Western Australian roads

    Directory of Open Access Journals (Sweden)

    Suphat Chummuneerat

    2014-12-01

    Full Text Available The resilient modulus (RM of hydrated cement treated crushed rock base (HCTCRB affected by amount of hydration periods, compaction and dryback processes was presented using repeated load triaxial tests. The related trends of RM corresponding to the different hydration periods still cannot be concluded. Instead, It is found that the moisture content plays more major influence on the RM performance. Higher additional water during compaction of HCTCRB, even at its optimum moisture content and induced higher dry density, led to the inferior RM performance compared to the sample without water addition. The RM of damper samples can be improved through dryback process and superior to that of the sample without water addition at the same moisture content. However, the samples without water addition during compaction deliver the comparable RM values even its dry density is lower than the other two types. These results indicate the significant influence of moisture content to the performances of HCTCRB with regardless of the dry density. Finally, the experimental results of HCTCRB and parent material are evaluated with the K-θ model and the model recommended by Austroads. These two models provide the excellent fit of the tested results with high degree of determination.

  16. Population health and status of epidemiology in Western European, Balkan and Baltic countries.

    Science.gov (United States)

    Seniori Costantini, Adele; Gallo, Federica; Pega, Frank; Saracci, Rodolfo; Veerus, Piret; West, Robert

    2015-02-01

    This article is part of a series commissioned by the International Epidemiological Association, aimed at describing population health and epidemiological resources in the six World Health Organization (WHO) regions. It covers 32 of the 53 WHO European countries, namely the Western European countries, the Balkan countries and the Baltic countries. The burdens of mortality and morbidity and the patterns of risk factors and inequalities have been reviewed in order to identify health priorities and challenges. Literature and internet searches were conducted to stock-take epidemiological teaching, research activities, funding and scientific productivity. These countries have among the highest life expectancies worldwide. However, within- and between-country inequalities persist, which are largely due to inequalities in distribution of main health determinants. There is a long tradition of epidemiological research and teaching in most countries, in particular in the Western European countries. Cross-national networks and collaborations are increasing through the support of the European Union which fosters procedures to standardize educational systems across Europe and provides funding for epidemiological research through framework programmes. The number of Medline-indexed epidemiological research publications per year led by Western European countries has been increasing. The countries accounts for nearly a third of the global epidemiological publication. Although population health has improved considerably overall, persistent within- and between-country inequalities continue to challenge national and European health institutions. More research, policy and action on the social determinants of health are required in the region. Epidemiological training, research and workforce in the Baltic and Balkan countries should be strengthened. European epidemiologists can play pivotal roles and must influence legislation concerning production and access to high-quality data. © The

  17. Go East: Differences between Poland and Western European countries in the motivational structures underlying seafood consumption

    DEFF Research Database (Denmark)

    Scholderer, Joachim; Brunsø, Karen; Olsen, Svein Ottar

    in the Netherlands. Despite the variation between Western European countries, a common finding was a much higher consistency between intentions and actual consumption behavior as compared to Poland. The differences are discussed in terms of their implications for supply chain management, product supply...... a deeper understanding of the preferences, motives and usage patterns of Polish seafood consumers. The aim of the study was to fill this gap. Representative consumer samples from Poland (N = 1000) and four Western European countries (Belgium, Denmark, Netherlands, Spain; total N = 3800) were surveyed...

  18. Assessing variation in tolerance in 23 Muslim-majority and Western countries.

    Science.gov (United States)

    Milligan, Scott; Andersen, Robert; Brym, Robert

    2014-08-01

    Scholars disagree over whether Islam hinders the development of liberal democracy in Muslim-majority countries. We contribute to this debate by assessing the influence of Islam at the individual and national levels on ethnic, racial, and religious tolerance in 23 countries. Our analyses are based on a set of multilevel models fitted to World Values Survey data and national-level contextual information from various sources. Our findings suggest that people living in Muslim-majority countries tend to be less tolerant than are those living in Western countries. Although a significant part of this difference is attributable to variation in level of economic development and income inequality, Muslim countries remain less tolerant even after controlling for these factors. On the other hand, controlling for other individual-level factors, nonpracticing Muslims in Western countries are more tolerant than are all others in both Muslim-majority and Western countries. This finding challenges common claims about the effects of Islam as a religion on tolerance, suggesting that it is Islamic political regimes--not Islam itself--that pose problems for social tolerance.

  19. Do GCI indicators predict SME creation? A Western Balkans cross-country comparative analysis

    OpenAIRE

    Fëllënza Lushaku; Alban Elshani; Lekë Pula

    2016-01-01

    In early stages SMEs were seen as insignificant supplement to large business supply, whereas today they have a very important social and economic role, because of their contribution to job creation. These contributions are very valuable in times of crises and rising unemployment. In Kosovo and the Western Balkan countries, including countries such as Albania, Macedonia, Montenegro, Serbia and Bosnia and Herzegovina, the development of SMEs can contribute in facing many challenges, effects of ...

  20. Evolution of the ageing process, quality of life and physical fitness in western countries

    OpenAIRE

    Ruiz-Montero, Pedro Jesús; Chiva, Oscar

    2017-01-01

    It is predicted that life expectancy will raise sharply in future stages, especially in western countries. In fact, life expectancy of developed countries is currently over the age of 70. Aging implies a series of physical, psychological, cognitive and social changes that condition one's self-concept, creating adaptive strategies and the knowledge to maintain one's well-being in spite of the changes. Albeit aging is a natural and inevitable process, the benefits of physical fitnes...

  1. Intercultural Effectiveness Training in three Western immigrant countries : A cross-cultural evaluation of critical incidents

    NARCIS (Netherlands)

    Herfst, Selma L.; van Oudenhoven, Jan Pieter; Timmerman, Marieke E.

    The purpose of the present study is the evaluation of material for a new intercultural training instrument. More specifically, we examine the validity of 21 critical incidents used in the training. The training programme is targeted at natives in Western immigrant countries dealing - mostly

  2. Framing the Iraq war: a cross-national comparison of newspaper framing in four Western countries

    NARCIS (Netherlands)

    Vliegenthart, R.; Schröder, H.

    2010-01-01

    In this paper we compare the newspaper attention for and framing of the Iraq issue in four Western countries (US, UK, Germany and the Netherlands) during the period September 2002 until August 2003. Using computer assisted coding based on wordlists constructed by human coders, we analyzed more than

  3. Peculiarities of Future Finance and Economics Specialists' Training in Western European Countries and Ukraine

    Science.gov (United States)

    Homoniuk, Olena; Pokudina, Larysa

    2016-01-01

    The article touches on the peculiarities of future finance and economics specialists' training in educational establishments of Western Europe and Ukraine. The problem of higher economic education has been considered. The experience of higher economic education organization in developed European countries has been generalized. The peculiarities of…

  4. Modelling Factors of Students' Work in Western Balkan Countries

    Science.gov (United States)

    Savic, Mirko; Kresoja, Milena

    2018-01-01

    The positive side of employment during studies is the increase of net investments in human capital. The main objective of this paper is to discover factors influencing the work of students in Serbia, Bosnia and Herzegovina and Montenegro and to compare students' employment in these three Western Balkan countries. Quantitative analysis based on…

  5. Tolerance of suicide, religion and suicide rates : an ecological and individual study in 19 Western countries

    NARCIS (Netherlands)

    Neeleman, J; Halpern, D; Leon, D; Lewis, G

    Background. Negative associations between religion and suicide, in individuals and countries, may be mediated by the degree to which suicide is tolerated. Methods. Linear regression was used to examine ecological associations between suicide tolerance, religion and suicide rates in 19 Western

  6. Peculiarities of the Research of the History of Western European Countries, Case of Norway

    Directory of Open Access Journals (Sweden)

    Alexey A. Vorobiev

    2015-01-01

    Full Text Available Abstract: Researcing of history of small advanced countries of Western Europe has a number of specific features, which are connected to its socio-economic level and dynamic development and the dependence on the external economic factor. So the article is devoted to the analysis of regularity of the development of the industry of Norwegian economic specialization (energy sector in the international division of labour as an important element of its historical development. The author of the article analyzes the influence of the energy sector on the political life of the country, the balance of political forces, legislation, foreign policy priorities, and the history of the development of society. At the same time he uses the interdisciplinary approach to determine the relationship of cause and effect between historical events to compile a complete historical picture. The author concludes that the regularities in history are universal and concern all small highly developed countries of Western Europe including Norway. The complex of economic, social, political, financial, legal, tax, environmental and other measures of state support to specialized branches of the national economy is the main semantic rod of historical events in many of the small countries of Western Europe. Analysis of individual industries of the economy in the international division of labor should be an integral part of researches of the historical development of small countries which have a narrow structure of economy, because it helps to understand the peculiarities of the historical development of nations.

  7. Mergers and Acquisitions in the Banking Sector: The Case of Western Balkan Countries / BKT Albania

    Directory of Open Access Journals (Sweden)

    Lulzim Rashiti

    2016-11-01

    Full Text Available This paper aims to explain the financial system which is the engine force for the development of a trade economy. This system ensures payment means in economy and has an impact on its real activity, through the implementation of financial intermediation, acquisitions and mergers in the banking industry that have occurred in recent years in the Western Balkan countries, and monetary policy transmission in these countries. In developing countries, among which are also: Serbia, Macedonia, Albania, Montenegro, etc., banking industry is o" en almost the most important area in the financial system. Therefore, this paper will focus on the way the acquisitions and mergers occurred in the banking system, by assuming that many of the conclusions are applicable to the entire financial system in the Western Balkans. This paper will elaborate on this aspect a case study that deals with the acquisition of Banka Kombetare Tregtare (National Commercial Bank in Albania by the Turkish company Calik Holding (Akif Bank.

  8. The Impact of Tourism on Economic Growth in the Western Balkan Countries: An Empirical Analysis

    Directory of Open Access Journals (Sweden)

    Prof. Dr Nasir Selimi

    2017-06-01

    Full Text Available Purpose: The purpose of this research paper is to empirically analyse the effects of tourism on economic growth in Western Balkan countries (Albania, Bosnia and Herzegovina, Croatia, FYROM, Montenegro and Serbia. Design/Methodology/Approach: The empirical analysis consists of 17-year panel data of 6 countries over the period 1998 to 2014. Several models are analysed using the panel regression econometric techniques. The study investigates the random and fixed effects, as well as individual heterogeneity across those countries. Also, the Hausman Taylor IV estimator is used as the most appropriate model for this analysis. The real income per capita of the sample countries is modelled as dependent on the lagged income per capita, tourist arrivals, tourism receipts, FDI stock, exports and government expenditures. Findings: The estimation results in all types of models, and indicate that tourism has a positive and significant impact on economic growth in the Western Balkan countries. The Hausman Taylor IV model suggests that for every 1% increase of tourist arrivals, the output will increase approximately by 0.08%. Research limitations/implications: Although the Hausman Taylor IV model performs well, the results should be interpreted with caution. The analysis has its limitations; firstly, the total number of observations is relatively small for a panel regression analysis; secondly, the problem of endogenity is not completely avoided. However, the study implies that these countries should enhance efforts for joint tourism sector policies to engender economic sustainability. Originality/Value: To our best knowledge, this is the first attempt of estimating the effects of tourism on economic growth in the Western Balkan countries using the Hausman Taylor IV model.

  9. Physical self-concept of adolescents in Western Balkan countries: a pilot study.

    Science.gov (United States)

    Janić, Snežana Radisavljević; Jurak, Gregor; Milanović, Ivana; Lazarević, Dušanka; Kovač, Marjeta; Novak, Dario

    2014-10-01

    The aim of this study was to explore physical self-concept of adolescents of the Western Balkans (Serbia, Slovenia, Croatia, and Bosnia and Herzegovina) according to sex and country. The participants were 2,606 students, ages 13 and 14 years (M = 13.5, SD = 0.9). The Physical Self-Description Questionnaire (PSDQ) was used to assess multidimensional physical self-concept. The results show the interaction of sex and country for three dimensions of physical self-concept (Appearance, Global Physical Self-Concept, and Self-Esteem). It was shown that female and male adolescents' perception of physical appearance, self-esteem, and global physical self-concept is more susceptible to influences of socio-cultural factors in the monitored countries. In all other dimensions of Physical self-concept, sex differences were consistently manifested in favour of male adolescents, except in Flexibility. Regardless of adolescents' sex, under the increasing influence of Western culture in the Western Balkan countries, adolescents more critically evaluate their body and motor abilities.

  10. Net capital flows to and the real exchange rate of Western Balkan countries

    Directory of Open Access Journals (Sweden)

    Gabrisch Hubert

    2015-01-01

    Full Text Available This paper uses Granger causality tests to assess the linkages between changes in the real exchange rate and net capital inflows using the example of Western Balkan countries, which have suffered from low competitiveness and external imbalances for many years. The real exchange rate is a measure of a country’s price competitiveness, and the paper uses two concepts: relative unit labour cost and relative inflation differential. The sample consists of six Western Balkan countries for the period 1996-2012, relative to the European Union (EU. The main finding is that changes in the net capital flows precede changes in relative unit labour costs and not vice versa. Also, there is evidence that net capital flows affect the inflation differential of countries, although to a less discernible extent. This suggests that the increasing divergence in the unit labour cost between the EU and Western Balkan countries up to the global financial crisis was at least partly the result of net capital inflows. The paper adds to the ongoing debate on improving cost competitiveness through wage restrictions as the main vehicle to avert the accumulation of current account imbalances. It shows the importance of changes in the exchange rate regime, reform of the interaction between the financial and the real sector, and financial supervision and structural change.

  11. Irregular Migration flows and human trafficking in the Western Balkan countries: challenges of the covergence of counter-trafficking response

    OpenAIRE

    Mece, Merita H.

    2016-01-01

    Irregular migration on the Western Balkan route has marked an unprecedented number during the last five years. Evidence indicates that both, non-European nationals and Western Balkan citizens have been involved in this complex migratory flow being exposed to various risks of human trafficking. But Western Balkan countries are source, transit and destination countries of human trafficking while their states are not well organized to implement a comprehensive and well-coordinated regional respo...

  12. DOCTRINAL AND IDEOLOGICAL PARADIGM OF THE CONSERVATISM IN THE WESTERN EUROPEAN COUNTRIES

    Directory of Open Access Journals (Sweden)

    Nikola Gjorshoski

    2015-04-01

    Full Text Available This paper is an illustration of certain specifications in the conservative discourse in a certain European western countries. Each one of the countries from the western hemisphere has its particular peculiarities that determine the usage of the political operation by the conservative parties. Certainly, the complexity of the conservative ideology study has been enriching with the perception of the most basic practices in the political activity of the right parties in some western countries. This paper consists of a short definition about the conservatism followed by its primary and secondary principles. Then, continues to an individual cases in a three highly developed European countries where as a sample are taken the most significant parties in the conservative and Christian Democrat ideology. The conservatism as a political ideology has been formed in the middle of the XVII century as a resistance towards the shifts and the challenges that were under influence of the enlightenment, industrialization and the urbanization. If the conservatism as a political theory, ideology and practice originates from the countries with foregoing activities, logically emerges a need to study their characteristics. The author’s intention is to represent the traits creating the content of that ideology and activity, what are the distinction marks that would be the most appealing of the certain country, as well as to prove the link with the parties from the conservative family on a European level. The study of the conservatism as a political ideology in the modern ideological- doctrinal spectrum would be certainly impossible if there is no closer look to those paradigms.

  13. Facebook use and acculturation: The case of overseas Chinese professionals in western countries

    OpenAIRE

    Mao, Yuping; Qian, Yuxia

    2015-01-01

    textabstractThe emergence of social network sites has provided new opportunities for intercultural communication. This study is one of the first to explore the role of Facebook on the acculturation of Chinese professionals overseas. Through qualitative interviews, we explored how overseas Chinese professionals use Facebook to maintain their social networks, manage their multicultural identities, and adapt to Western culture in their host countries. Our research reveals that overseas Chinese p...

  14. Labour Market Institutions in the Western Balkan Countries and their Economic Implications: Evidence for Kosova

    Directory of Open Access Journals (Sweden)

    MSc. Anera Alishani

    2013-12-01

    To address this issue, this paper provides a literature review of the notion of flexicurity and then investigates the relevance of flexicurity for the countries of the Western Balkans through its found components (flexible and reliable contractual arrangements, lifelong learning, active employment policies and social security system. Even though flexicurity can be a way out for low performed economies it is considered as highly costly.

  15. SUSPECTED CHILD ABUSE: UNUSUAL DEATH IN WESTERN COUNTRY. SUICIDE OR HOMICIDE?

    Directory of Open Access Journals (Sweden)

    Letizia Averna

    2012-03-01

    Full Text Available This case report describes a particular case of carbonized corpse, found in his burnt-out car in an isolated Palermo’s west suburban zone. The goal of this case report is to describe the shame and the social stigma related with suspicious of pedophilia and how it led a man to suicide by fire, considering that is an unusual way to die in western countries.

  16. The contribution of tourism industry on the GDP growth of Western Balkan countries

    Directory of Open Access Journals (Sweden)

    Čerović Slobodan

    2015-01-01

    Full Text Available Tourism industry records various economic, social, political and others influences and provides itself important position in the overall economic development of many countries. The analysis of the available data of tourist arrivals and number of tourist overnight stays in observed countries of the Western Balkans (Serbia, Macedonia, Montenegro led us to conduct research in order to determine tourism contribution to the overall economic growth. Based on the modified methodology used by Brida et al. (2008 for calculating real GDP growth rates and tourism contribution to the overall economic growth, the paper indicates that tourism makes a modest direct contribution to the overall economic growth in the examined countries, regardless of the continuous increase in the number of foreign tourist arrivals. The level of tourism contribution to the overall economic growth varies and it is primarily related to diversity and quality of supply (the highest contribution is recorded in Montenegro, while lowest contribution is observed in Macedonia.

  17. Improving estimates of the prevalence of Female Genital Mutilation/Cutting among migrants in Western countries

    Directory of Open Access Journals (Sweden)

    Livia Elisa Ortensi

    2015-02-01

    Full Text Available Background: Female Genital Mutilation/Cutting (FGM/C is an emerging topic in immigrant countries as a consequence of the increasing proportion of African women in overseas communities. Objective: While the prevalence of FGM/C is routinely measured in practicing countries, the prevalence of the phenomenon in western countries is substantially unknown, as no standardized methods exist yet for immigrant countries. The aim of this paper is to present an improved method of indirect estimation of the prevalence of FGM/C among first generation migrants based on a migrant selection hypothesis. A criterion to assess reliability of indirect estimates is also provided. Methods: The method is based on data from Demographic Health Surveys (DHS and Multiple Indicator Cluster Surveys (MICS. Migrants' Selection Hypothesis is used to correct national prevalence estimates and obtain an improved estimation of prevalence among overseas communities. Results: The application of the selection hypothesis modifies national estimates, usually predicting a lower occurrence of FGM/C among immigrants than in their respective practicing countries. A comparison of direct and indirect estimations confirms that the method correctly predicts the direction of the variation in the expected prevalence and satisfactorily approximates direct estimates. Conclusions: Given its wide applicability, this method would be a useful instrument to estimate FGM/C occurrence among first generation immigrants and provide corresponding support for policies in countries where information from ad hoc surveys is unavailable.

  18. Price dispersion in neighboring countries in the Western Balkans - the case of the Macedonian tomato industry

    Directory of Open Access Journals (Sweden)

    Blazhe JORDANOV

    2013-03-01

    Full Text Available The aim of this paper was to analyze the degree of change in price and co- movement of prices between markets. The distinctiveness of the study is that it introduced a single product (highly perishable product price relationship analysis between a pair of spatially separated markets in the countries of the Western Balkan. This study attempts to comprehend to what extent the Macedonian domestic market is integrated into the regional markets, as well as to understand the relationship between the spatially separated regional markets. The data refer to the domestic Macedonian market and four different regional markets (Croatia, Serbia, Kosovo and Montenegro, as major importers of Macedonian fresh tomatoes. These countries were part of a common market until the 1990s and in the past period transited to a market economy. The method used is common time series analysis through unit root test, co-integration test and causality test. The study showed that the Macedonian economy, especially in terms of the tomato industry, is highly vulnerable and dependant on external markets. Future developments do not only depend upon the advances in the country, but also on developments in the export destinations. This also applies to the other concerned countries in the regions. The main finding is that a small country such as Macedonia is absorbed by developments in other countries in the region. This finding is supported by the results of the study that demonstrated a high level of co-integration between the domestic and regional markets.

  19. Dietary intake and habits of South Asian immigrants living in Western countries.

    Science.gov (United States)

    LeCroy, Madison N; Stevens, June

    2017-06-01

    Previous reviews have indicated that immigration from South Asian to Western countries leads to unhealthy changes in diet; however, these reviews have been limited by the methods used in some included studies. This critical narrative review summarizes findings from original research articles that performed appropriate statistical analyses on diet data obtained using culturally appropriate diet assessment measures. All studies quantitatively compared the diets of South Asian immigrants with those of residents of Western or South Asian countries or with those of South Asian immigrants who had varying periods of time since immigration. Most studies examined total energy and nutrient intake among adults. Total energy intake tended to decrease with increasing duration of residence and immigrant generation, and immigrants consumed less protein and monounsaturated fat compared with Westerners. However, findings for intakes of carbohydrate, total fat, saturated fat, polyunsaturated fat, and micronutrients were mixed. Studies that examine food group intake and include South Asians living in South Asia as a comparison population are needed. © The Author(s) 2017. Published by Oxford University Press on behalf of the International Life Sciences Institute. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  20. How do government regulations influence the ability to practice Chinese herbal medicine in western countries.

    Science.gov (United States)

    Fleischer, Tom; Su, Yi-Chang; Lin, Sunny Jui-Shan

    2017-01-20

    The regulation policies of substances used in Chinese Herbal Medicine (CHM), have a direct influence on the ability of health providers to practice in the clinic. We set out to assess the truth behind the assumption that practice of CHM in the west is constrained by the regulations imposed by authorities in western countries. For the first part of our study we surveyed and compiled lists of banned and restricted Chinese Materia Medica (CMM) from six countries: USA, UK, Germany, Israel, Canada and Australia. Afterwards, we estimated the relevant importance of the 300 CMM most-commonly-prescribed to the practice of CHM according to prescriptions from 2,000,000 randomly selected patients, from the Taiwanese National Health Insurance Research Database (NHIRD). We then compared both lists and determined the clinical importance of the banned and restricted CMM. Except for regulations from Canada, most of the information of banned CMM proved to be difficult to organize. The USA was found to have the least amount of banned herbs, with 9 substances. Canada had the highest amount, with 98. In Germany, Australia, the UK, and Israel 10, 29, 36, 68 banned CMM were found, respectively. Apart from aristolochic acid containing substances, ma huang (, Ephedra sinica) was the only CMM banned in all countries. Most of the banned CMM were not found to be among the most-commonly-prescribed according to the NHIRD. Authorities should make this information more accessible. No clear relation exists between CHM regulations and any 'Western' common denominator, and the amount of banned CMM varied greatly among the surveyed countries. However, even among countries with a larger amount of banned CMM, the majority of these were in the bottom two-thirds in respect to the frequency of their use. Thus, regulations in some western countries surely influence the practice of CHM, however, the variability of CMM have been influenced by regulations only to a limited extent. Copyright © 2016 The

  1. Dietary heterogeneity among Western industrialized countries reflected in the stable isotope ratios of human hair.

    Science.gov (United States)

    Valenzuela, Luciano O; Chesson, Lesley A; Bowen, Gabriel J; Cerling, Thure E; Ehleringer, James R

    2012-01-01

    Although the globalization of food production is often assumed to result in a homogenization of consumption patterns with a convergence towards a Western style diet, the resources used to make global food products may still be locally produced (glocalization). Stable isotope ratios of human hair can quantify the extent to which residents of industrialized nations have converged on a standardized diet or whether there is persistent heterogeneity and glocalization among countries as a result of different dietary patterns and the use of local food products. Here we report isotopic differences among carbon, nitrogen and sulfur isotope ratios of human hair collected in thirteen Western European countries and in the USA. European hair samples had significantly lower δ(13)C values (-22.7 to -18.3‰), and significantly higher δ(15)N (7.8 to 10.3‰) and δ(34)S (4.8 to 8.3‰) values than samples from the USA (δ(13)C: -21.9 to -15.0‰, δ(15)N: 6.7 to 9.9‰, δ(34)S: -1.2 to 9.9‰). Within Europe, we detected differences in hair δ(13)C and δ(34)S values among countries and covariation of isotope ratios with latitude and longitude. This geographic structuring of isotopic data suggests heterogeneity in the food resources used by citizens of industrialized nations and supports the presence of different dietary patterns within Western Europe despite globalization trends. Here we showed the potential of stable isotope analysis as a population-wide tool for dietary screening, particularly as a complement of dietary surveys, that can provide additional information on assimilated macronutrients and independent verification of data obtained by those self-reporting instruments.

  2. Dietary heterogeneity among Western industrialized countries reflected in the stable isotope ratios of human hair.

    Directory of Open Access Journals (Sweden)

    Luciano O Valenzuela

    Full Text Available Although the globalization of food production is often assumed to result in a homogenization of consumption patterns with a convergence towards a Western style diet, the resources used to make global food products may still be locally produced (glocalization. Stable isotope ratios of human hair can quantify the extent to which residents of industrialized nations have converged on a standardized diet or whether there is persistent heterogeneity and glocalization among countries as a result of different dietary patterns and the use of local food products. Here we report isotopic differences among carbon, nitrogen and sulfur isotope ratios of human hair collected in thirteen Western European countries and in the USA. European hair samples had significantly lower δ(13C values (-22.7 to -18.3‰, and significantly higher δ(15N (7.8 to 10.3‰ and δ(34S (4.8 to 8.3‰ values than samples from the USA (δ(13C: -21.9 to -15.0‰, δ(15N: 6.7 to 9.9‰, δ(34S: -1.2 to 9.9‰. Within Europe, we detected differences in hair δ(13C and δ(34S values among countries and covariation of isotope ratios with latitude and longitude. This geographic structuring of isotopic data suggests heterogeneity in the food resources used by citizens of industrialized nations and supports the presence of different dietary patterns within Western Europe despite globalization trends. Here we showed the potential of stable isotope analysis as a population-wide tool for dietary screening, particularly as a complement of dietary surveys, that can provide additional information on assimilated macronutrients and independent verification of data obtained by those self-reporting instruments.

  3. [Disparities of breast cancer burden between China and western countries and its implication].

    Science.gov (United States)

    Zheng, Ying; Zhang, Minlu

    2015-12-01

    The disease burden of breast cancer in China is growing, and its proportion contributed to the global burden is increasing accordingly. The western countries have achieved reduction of mortality and slow growth of incidence, while the breast cancer incidence and mortality rates have been increasing constantly with lower survival rates in China. The remarkable characteristics of breast cancer burden in China is the disparities of the current status and time trends of incidence, mortality and survival between urban and rural area. The breast cancer disease distributions and time trends in China and the differential from the developed countries are described, which may be benefit to draw the international experience on prevention, early detection, medical care and survival management. Assessment of the existing evidence, elaboration of the prevention, control strategies in consideration of Chinese social-economic and culture situation would be beneficial to rise to the future challenge.

  4. The Impact of Foreign Direct Investment on the Export Performance: Empirical Evidence for Western Balkan Countries

    Directory of Open Access Journals (Sweden)

    Dr.Sc. Nasir Selimi

    2016-07-01

    Full Text Available Recently there are many authors that have studied and analyzed the impact of foreign direct investments (FDI on the export performance. They have different opinions about the effect of foreign direct investments on the export performance. Some of them in their papers conclude that FDI have positive effect on the export performance and some not. There are also findings that FDI do not have any impact on the export performance. Of course for economic benefit of host country it is not important only the amount of FDI, but also their structure. To measure the effect of FDI on the export performance is not easy. Therefore, the main objective of this paper is to analyze empirically the foreign direct investments and exports performance during the period of 1996-2013 in Western Balkan countries. The paper also investigates for the fixed effects and individual heterogeneity across countries and years. Based on the panel regression techniques and Least Square Dummy Variable (LSDV regression method, FDI positively affect export performance in the sample countries in various model specifications. The results and conclusions of this paper we hope that will help everybody who are interested and studying this matter, especially the policy makers.  The last ones have the obligation to facilitate and promote the export if they award confirm that FDI contribute on developing their economy.

  5. Naso-ethmoidal encephalocele with bilateral orbital extension: report of a case in a western country.

    Science.gov (United States)

    Secci, Francesca; Consales, Alessandro; Merciadri, Paolo; Ravegnani, Giuseppe Marcello; Piatelli, Gianluca; Pavanello, Marco; Cama, Armando

    2013-10-01

    Encephalocele is a rare congenital malformation of the central nervous system with protrusion of cranial content (meninges, brain, and ventricles in different combinations) beyond the normal confines of the skull. Anterior encephaloceles occur with a high frequency in Southeast Asia, while in the Western countries occipital encephaloceles prevail. The treatment of an anterior (naso-ethmoidal) encephalocele involves a neurosurgeon or a multidisciplinary team (neurosurgeon, maxillofacial surgeon, plastic surgeon, and ENT surgeon) dealing with craniofacial surgery. Goals of surgery include removal or repositioning of nonfunctional cerebral tissue, closure of the dura, and reconstruction of skeletal and cutaneous structures. The prognosis depends from the anatomical site, volume of neural contents, and the presence of coexisting malformations. We report the case of an Italian child suffering from a naso-ethmoidal encephalocele with bilateral orbital extension. The surgical treatment was performed in two steps. Sincipital encephalocele is a complex pathology without a unique standardized surgical treatment. Its low incidence in Western countries can make its management particularly tricky.

  6. Impact of unemployment variations on suicide mortality in Western European countries (2000-2010).

    Science.gov (United States)

    Laanani, Moussa; Ghosn, Walid; Jougla, Eric; Rey, Grégoire

    2015-02-01

    A scientific debate is currently taking place on whether the 2008 economic crisis caused an increase in suicide rates. Our main objective was to assess the impact of unemployment rate on suicide rate in Western European countries between 2000 and 2010. We then tried to estimate the excess number of suicides attributable to the increase of unemployment during the 2008-2010 economic crisis. The yearly suicide rates were modelled using a quasi-Poisson model, controlling for sex, age, country and a linear time trend. For each country, the unemployment-suicide association was assessed, and the excess number of suicides attributable to the increase of unemployment was estimated. Sensitivity analyses were performed, notably in order to evaluate whether the unemployment-suicide association found was biased by a confounding context effect ('crisis effect'). A significant 0.3% overall increase in suicide rate for a 10% increase in unemployment rate (95% CI 0.1% to 0.5%) was highlighted. This association was significant in three countries: 0.7% (95% CI 0.0% to 1.4%) in the Netherlands, 1.0% (95% CI 0.2% to 1.8%) in the UK and 1.9% (95% CI 0.8% to 2.9%) in France, with a significant excess number of suicides attributable to unemployment variations between 2008 and 2010 (respectively 57, 456 and 564). The association was modified inconsistently when adding a 'crisis effect' into the model. Unemployment and suicide rates are globally statistically associated in the investigated countries. However, this association is weak, and its amplitude and sensitivity to the 'crisis effect' vary across countries. This inconsistency provides arguments against its causal interpretation. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  7. Bringing Western-standard service stations to the Baltic countries. Neste palvelee Baltiassa laadulla ja varmuudella

    Energy Technology Data Exchange (ETDEWEB)

    Pesonen, H.

    1992-01-01

    Neste is the only Western oil company so far to have established a service station presence in the Baltic, with the exception of Norway's Statoil, which has one outlet near Tallinn Airport. Neste has an important logistical advantage compared to other companies in this respect as its two Finnish refineries are ideally located for supplying the region with high-quality petroleum products. Neste's first joint venture in the Baltic, Traffic Service, based in Estonia, was set up with Eesti Kutus in 1988 and opened its first service station in 1990. Other joint ventures are now up and running in Latvia, Lithuania, Poland, and St. Petersburg. A total of 10 - 15 stations, the majority strategically located along the route of the Via Baltica, are expected to be operational by the end of this year. The Neste network comprises a combination of new outlets and refurbished older stations that have been modernized to bring them up to Western standards. These offer a comprehensive range of fuels, lubricants, spare parts, and accessories, as well as food, confectionery, and coffee shop services. Some stations also offer repair and car wash facilities. Adapting to the transition from a communist economy to a Western, capitalist one has not been easy for the Baltic countries, and has inevitably created difficulties for companies like Neste, in areas such as legislation covering land ownership. Neste's joint ventures have also encountered difficulties in instilling the Western approach to business efficiency, and customer service in a workforce used to the Soviet retail system.

  8. IRREGULAR MIGRATION FLOWS AND HUMAN TRAFFICKING IN THE WESTERN BALKAN COUNTRIES: CHALLENGES OF THE CONVERGENCE OF COUNTER-TRAFFICKING RESPONSE

    Directory of Open Access Journals (Sweden)

    Merita H. Mece

    2016-05-01

    Full Text Available Irregular migration on the Western Balkan route has marked an unprecedented number during the last five years. Evidence indicates that both, non-European nationals and Western Balkan citizens have been involved in this complex migratory flow being exposed to various risks of human trafficking. But Western Balkan countries are source, transit and destination countries of human trafficking while their states are not well organized to implement a comprehensive and well-coordinated regional response to combat it. This paper aims at examining challenges faced by the Western Balkan countries to converge anti-trafficking response while facing increased irregular migratory waves. Using secondary data it illustrates various disparities and differences among them concluding that a well-coordinated, multi-faceted and integrated regional response is needed to combat this humanitarian problem.

  9. Mingadhuga Mingayung: Respecting Country through Mother Mountain's Stories to Share Her Cultural Voice in Western Academic Structures

    Science.gov (United States)

    McKnight, Anthony

    2015-01-01

    The cultural invasion of Yuin Country in Australia not only colonized the Yuin people and Yuin Country itself, but also contributed to non-Aboriginal people's continual colonized journey of disconnecting self from Mother Earth. Cultural awareness is a process driven by Western theories informed by the colonial dualism that functions on separation…

  10. Experience of Forming Professional and Communicative Competency of Future Social Workers in Education Systems of Western European Countries

    Science.gov (United States)

    Baranyuk, Vita

    2015-01-01

    The article analyzes the experience of forming professional and communicative competency of future social workers in the education systems of Western European countries, in particular, France, Germany and Switzerland. On the basis of generalization of the studied data it has been found out that each country has its own techniques of forming…

  11. Do GCI indicators predict SME creation? A Western Balkans cross-country comparative analysis

    Directory of Open Access Journals (Sweden)

    Fëllënza Lushaku

    2016-03-01

    Full Text Available In early stages SMEs were seen as insignificant supplement to large business supply, whereas today they have a very important social and economic role, because of their contribution to job creation. These contributions are very valuable in times of crises and rising unemployment. In Kosovo and the Western Balkan countries, including countries such as Albania, Macedonia, Montenegro, Serbia and Bosnia and Herzegovina, the development of SMEs can contribute in facing many challenges, effects of inequality, high level of unemployment and demographic challenges. In addition, SME development can contribute to strengthening the competitiveness and productivity, while also promoting the growth of income per capita. Besides the positive perception the creation of small and medium enterprises has, it is also indispensable to consider their extinction rate, being the most affected category of businesses, especially in the initial stages. It is proved that the net SME creation and cross-country differences in the relationship between new businesses and extinct businesses, can serve as a recommendation for policy makers in order to create a favorable climate for small and medium enterprises. GCI indicators that measures global competitiveness are used to determine if the climate of competitiveness predicts the development of SMEs.

  12. Integrative review of cervical cancer screening in Western Asian and Middle Eastern Arab countries.

    Science.gov (United States)

    Ali, Suhailah; Skirton, Heather; Clark, Maria T; Donaldson, Craig

    2017-12-01

    Population-based screening programs have resulted in minimizing mortality and morbidity from cervical cancer. The aim of this integrative review was to explore the factors influencing access of women from Western Asian and Middle Eastern Arab countries to cervical cancer screening. A systematic search for studies conducted in Arab countries in those regions, and published in English between January 2002 and January 2017, was undertaken. Thirteen papers were selected and subjected to quality appraisal. A three step analysis was used, which involved a summary of the evidence, analysis of both quantitative and qualitative data, and integration of the results in narrative form. Few population-based cervical cancer screening programs had been implemented in the relevant countries, with low knowledge of, and perceptions about, cervical screening among Arab women, the majority of whom are Muslim. Factors affecting the uptake of cervical cancer screening practices were the absence of organized, systematic programs, low screening knowledge among women, healthcare professionals' attitudes toward screening, pain and embarrassment, stigma, and sociocultural beliefs. Policy changes are urgently needed to promote population-based screening programs. Future research should address the promotion of culturally-sensitive strategies to enable better access of Arab Muslim women to cervical cancer screening. © 2017 John Wiley & Sons Australia, Ltd.

  13. Product availability from delivery aspect: Evidence from retailers in selected Western Balkan countries

    Directory of Open Access Journals (Sweden)

    Grubor Aleksandar

    2016-01-01

    Full Text Available Bearing in mind that it represents one of the main preconditions of sales, product availability is the key task of retail companies and their delivery systems. This paper analyses its levels from the aspect of centralized and DSD systems. The research is conducted in Serbia, Bosnia and Herzegovina and Montenegro, including 84 stores and more than 70 FMCG products per each store. Thereby, the comparisons in product availability levels between alternative delivery systems are carried out within different trading formats and within different product categories. Unlike the results of similar studies and ongoing changes on retail markets, this research shows that at retailers in these Western Balkan countries, availability levels are higher in the case of DSD system.

  14. Risk factors for acute care hospital readmission in older persons in Western countries

    DEFF Research Database (Denmark)

    Pedersen, Mona Kyndi; Meyer, Gabriele; Uhrenfeldt, Lisbeth

    2017-01-01

    related to socio-demographics, health characteristics and clinical and organizational factors related to the care pathway. TYPES OF STUDIES: The current review considered analytical and descriptive epidemiological study designs that evaluated risk factors for acute care hospital readmission. OUTCOMES......: The outcome was readmission to an acute care hospital within one month of discharge. SEARCH STRATEGY: A three-step search was utilized to find published and unpublished studies in English, French, German, Norwegian, Swedish or Danish. Five electronic databases were searched from 2004 to 2013, followed...... summary and metasynthesis of the quantitative findings was conducted. RESULTS: Based on a review of nine studies from ten Western countries, we found several significant risk factors pertaining to readmission to an acute care hospital within one month of discharge in persons aged 65 years and over...

  15. Iceland as a western country. How to classify medieval church law in the vernacular

    Directory of Open Access Journals (Sweden)

    Lára Magnúsardóttir

    2015-12-01

    Full Text Available Iceland’s subjection to the king of Norway in 1262-64 was followed by a legislation in which a law book for Church and spiritual matters was composed in the vernacular for each country. Such law was implemented in Iceland in 1275 along with a separate secular law book in 1281. Both books remained in force until the middle of the 16th century. A church law that was separate, both from the secular law and that of Roman Church appears to set Iceland apart from other Western European countries where spiritual matters were governed according to the Latin law of the Roman Church. This has been viewed as an indication of constant rivalry between the religious and secular authorities, usually presenting the Church as an overreaching and even oppressive institution against which laity struggled. But a comparison of Icelandic Church law with the Latin Canon law shows that the Church in Iceland submitted entirely to the authority of the Roman Church and thus shows that the Icelandic Church law was, despite its obscure language, a specific representation of the law of the Roman Church. A Norwegian concordat from 1277 shows the king’s recognition of separate spiritual and temporal jurisdictions. This cooperation is readily apparent in later court cases.

  16. The Exploration of Mars and the Improvement of Living Conditions in Western Asian Countries

    Science.gov (United States)

    De Morais Mendonca Teles, Antonio

    2016-07-01

    Space is the new frontier. The exploration of a new world, Mars, has been giving people on Earth valuable comparative information about climatic and geological processes occurring here on our home planet. With the Viking 1 and 2, Mars Global Surveyor, Mars Odyssey, Mars Reconnaissance Orbiter, Sojourner, Spirit, Opportunity, Curiosity, etc., spacecrafts, which explored the Red Planet we obtained a great deal information about the extremely arid soil and dry air of Mars in the present, and its watery condition in the distant past. Now there is a decade-long, program of robotic exploration of the martian atmosphere and soil - the 'Mars Surveyor Program', which is a series of small, cheap and fast spacecrafts, carrying very few scientific instruments, to be launched about every two years. Here in this paper, under the principles in the United Nations' Agenda 21, we comment on this new phase of Mars exploration under development, which began in 1996, and its benefits to living conditions in developing countries with desert regions. A peaceful regular research of the arid Mars, will help us to understand much better the dynamics of formation of dry regions here on Earth. We suggest that, if the developing countries participate in that program, they will achieve the scientific understanding to create a practical technology, with which they will acquire ways to future transform their arid areas into a more humid places, and to slow the process of desertification of other regions. This, using their own natural resources and own scientific personnel. That would strongly benefit the living conditions in Western Asian countries, which have many desert regions.

  17. Different trends in euthanasia acceptance across Europe. A study of 13 western and 10 central and eastern European countries, 1981-2008.

    Science.gov (United States)

    Cohen, Joachim; Van Landeghem, Paul; Carpentier, Nico; Deliens, Luc

    2013-06-01

    We examined how acceptance of euthanasia among the general public has changed between 1981 and 2008 in western and central and eastern European (CEE) countries using data of the European Values Surveys. Data were collected in 1981, 1990, 1999 and 2008 for 13 western European countries and in 1990, 1999 and 2008 for 10 CEE countries. Euthanasia acceptance increased each decade up until 2008 in 11 of 13 western European countries; in CEE countries, it decreased or did not increase between 1999-2008 in 8 of 10 countries. A number of explanations for and implications of this apparent east-west polarization are suggested.

  18. Options of biofuel trade from Central and Eastern to Western European countries

    International Nuclear Information System (INIS)

    van Dam, J.; Faaij, A.P.C.; Lewandowski, I.; Van Zeebroeck, B.

    2009-01-01

    Central and Eastern European countries (CEEC) have a substantial biomass production and export potential. The objective of this study is to assess whether the market for biofuels and trade can be profitable enough to realize a supply of biofuels from the CEEC to the European market and to estimate the cost performance of the energy carriers delivered. Five NUTS-2 (Nomenclature d'Unites Territoriales Statistiques) regions with high biomass production potentials in Poland, Romania, Hungary and the Czech Republic were analysed for biofuel export options. From these regions pellets from willow can be provided to destination areas in Western European countries (WEC) at costs of 105.2-219.8 EUR t -1 . Ethanol can be provided at 11.95-20.89 EUR per GJ if the biomass conversion is performed at the destination areas in the WEC or at 14.84-17.83 EUR GJ -1 J if the biomass to ethanol conversion takes place (at small scale) at the CEEC region where the biomass is produced. Short sea shipping shows most cost advantages for longer distance international transport compared to inland waterway shipping and railway. Another reason for lower biofuel supply costs are shorter distances between the regions of biomass production and the destination areas. Therefore the Szczecin region in Poland, closely located to the Baltic Sea, shows a better economic performance for long distance trade of biomass production than the selected region in Hungary ('land-locked'). It is concluded that in future key CEEC regions can supply (pre-treated) biomass and biofuels to the European market at cost levels, which are sound and attractive to current and expected diesel and gasoline prices. (author)

  19. Cermet cements.

    Science.gov (United States)

    McLean, J W

    1990-01-01

    Cermet ionomer cements are sintered metal/glass powders, which can be made to react with poly(acids). These new cements are significantly more resistant to abrasion than regular glass ionomer cements and are widely accepted as core build-up materials and lining cements. They can strengthen teeth and provide the clinician with an opportunity to treat early dental caries.

  20. On Cooperation and Competition: A Comparative Analysis of National Policies for Internationalisation of Higher Education in Seven Western European Countries

    Science.gov (United States)

    Luijten-Lub, Anneke; Van der Wende, Marijk; Huisman, Jeroen

    2005-01-01

    The focus of this article is on a comparison of the national policies for internationalisation in seven Western European countries (Austria, Germany, Greece, the Netherlands, Norway, Portugal, and the United Kingdom). In this comparison, it will be shown that the trend suggested in previous research of increasing economical rationales for…

  1. Higher Education Co-operation and Western Dominance of Knowledge Creation and Flows in Third World Countries.

    Science.gov (United States)

    Selvaratnam, Viswanathan

    1988-01-01

    Third World adoption of the Western university and the accompanying Eurocentric system of information flow is criticized as sometimes being counterproductive and alien to developing nations. The potential for a self-reliant, interdependent higher education system among Third World countries is discussed. (MSE)

  2. Nurse prescribing of medicines in Western European and Anglo-Saxon countries: a survey on forces, conditions and jurisdictional control.

    NARCIS (Netherlands)

    Kroezen, M.; Francke, A.L.; Groenewegen, P.P.; Dijk, L. van

    2012-01-01

    Background: The number of Western European and Anglo-Saxon countries where nurses are legally allowed to prescribe medicines is growing. As the prescribing of medicines has traditionally been the task of the medical profession, nurse prescribing is changing the relationship between the medical and

  3. Explaining the gender gap in radical right voting: A cross-national investigation in 12 Western European countries

    NARCIS (Netherlands)

    Immerzeel, Tim; Coffe, Hilde; van der Lippe, Tanja

    2015-01-01

    It is common wisdom in radical right research that men are over-represented among the radical right electorate. We explore whether a radical right gender gap exists across 12 Western European countries and examine how this gap may be explained. Using the European Values Study (2010), we find a

  4. Economic analysis of different supporting policies for the production of electrical energy by solar photovoltaics in western European Union countries

    International Nuclear Information System (INIS)

    Dusonchet, Luigi; Telaretti, Enrico

    2010-01-01

    Within various renewable energy technologies, photovoltaics (PV) today attracts considerable attention due to its potential to contribute a major share of renewable energy in the future. However, PV market development is, undoubtedly, dependent on the political support of any given country. In this paper, after a brief analysis of national support policies in PV technology in western European Union (EU) countries, the authors perform an economic analysis of the main support mechanisms as implemented in the same countries, based on the calculation of the cash flow, the Net Present Value (NPV) and the Internal Rate of Return (IRR) indices. The analysis shows that in some situations support policies can be inconvenient for the owner of the PV-based generation system and that, in many cases, the differences between the implementation of the same support policy in different countries, can give rise to significantly different results. The analysis carried out in this work could help: ·to assess the impact of PV energy policies in different western European member states; ·renewable energy companies to identify potential PV markets and investigate the policy landscape across western EU countries.

  5. Trend in environmental education images of textbooks from Western and Eastern European countries and non-European countries

    OpenAIRE

    2011-01-01

    Abstract Textbook analysis is seen as a major element for studying environmental education addressing pupils, being image analysis rather relevant when studying textbooks written in 11 languages. We analysed 25 textbooks from 14 countries addressed to 14-16 years old pupils, focusing on: (i) local and foreign/global images; (ii) urban/rural and nature images; (iii) negative impact, human management and the beauty of nature; and (iv) men and women in images with negative and positiv...

  6. Pharmacological treatment for attention deficit hyperactivity disorder: functional outcomes in children and adolescents from non-Western countries

    OpenAIRE

    Altin, Murat; El-Shafei, Ahmed A; Yu, Maria; Desaiah, Durisala; Treuer, Tamas; Zavadenko, Nikolay; Gao, Hong Yun

    2013-01-01

    Objective: Functional outcomes were measured over a 12-month period in children and adolescents with attention deficit hyperactivity disorder (ADHD) after they received monotherapy. Design: Prospective, observational, noninterventional study. Setting: Conducted in six non-Western countries. Participants: Outpatients 6 to 17 years of age with a verified diagnosis of ADHD in accordance with the Diagnostic and Statistical Manual, Fourth Edition, Text Revision (DSM-IV-TR), together with t...

  7. A longitudinal comparison of age patterns and rates of suicide in Hong Kong, Taiwan and Japan and two Western countries.

    Science.gov (United States)

    Snowdon, John; Chen, Ying-Yeh; Zhong, Baoliang; Yamauchi, Takashi

    2018-01-01

    Suicide data relating to 1979-2014 were obtained from three East Asian jurisdictions (Taiwan, Hong Kong, Japan) and two 'Western' countries (Australia, New Zealand). Rates and age patterns of suicide have changed markedly since 1979. Graphs of these patterns largely remained either upward-sloping, bimodal or flat (uniform) over the 36 years, male commonly differing from female, and East Asian patterns more like each other than those of the Western countries. Japan's male middle-aged suicide rate reached a peak in 1999-2003, which, like increased rates among working age males in Hong Kong and Taiwan, has been attributed largely to consequences of Asian financial crises. Male to female ratios of suicide rates have remained higher in the Western countries, but late life suicide rates have decreased to varying extents in all five jurisdictions. Identifying reasons for differences between jurisdictions in their suicide rates and patterns at particular times, and over time, is likely to point to factors (period, cohort, psychosocial or cultural) that protect against or foster suicidal ideation. This avenue of research may assist in identifying ways of preventing suicide. Copyright © 2017. Published by Elsevier B.V.

  8. Comparison of perceived barriers to entrepreneurship in Eastern and Western European countries

    NARCIS (Netherlands)

    Iakovleva, T.A.; Kolvereid, L.; M.J. Gorgievski-Duijvesteijn (Marjan); Sørhaug, Ø

    2014-01-01

    textabstractThis qualitative study among 591 business students from four European countries investigated cross-country differences in the kind of barriers people perceive to business start-up. In line with institutional theory, the most important perceived barriers in all countries related to

  9. Petrologic and stable isotopic studies of a fossil hydrothermal system in ultramafic environment (Chenaillet ophicalcites, Western Alps, France): Processes of carbonate cementation

    Science.gov (United States)

    Lafay, Romain; Baumgartner, Lukas P.; Stephane, Schwartz; Suzanne, Picazo; German, Montes-Hernandez; Torsten, Vennemann

    2017-12-01

    The Late Jurassic Chenaillet ophiolitic complex (Western Alps) represents parts of an oceanic core-complex of the Liguria-Piemonte domain. A model for the origin and evolution of the Chenaillet ophicalcites based on textural and isotopic characterization is presented. The Chenaillet ophicalcites correspond to brecciated serpentinized peridotites that record seafloor shallow serpentinization at a minimum temperatures of 150 °C followed by authigenic carbonation. Carbonation starts with a network of micrometric to millimetric pre- or syn-clast formation calcite veins accompanied by a pervasive carbonation of residual olivine and serpentine inside the serpentinite mesh core. A matrix of small calcite (values that range between - 5‰ and + 0.4‰. The lower values were obtained for calcite within the serpentinite clasts. The δ18O (VSMOW) values have a range between + 11‰ and + 16‰ in carbonated clasts. The δ18O values in the matrix are fairly homogeneous with an average at + 12‰ and the late calcite veins have values between + 12.5 and + 15.5‰. These values suggest a relatively high temperature of formation for all the carbonates. Carbonates within clast are mainly characterized by a formation temperature in the range of 110 °C to 180 °C assuming a δ18O value of seawater of 0‰, the matrix forms at a temperature of ca. 165 °C. Late veins are characterized by a formation temperature ranging between 120and 155 °C. We propose a model where serpentinization is followed by discrete carbonation then brecciation and cementation as a consequence of continuous hydrothermal fluid circulation in the serpentinite basement. This is comparable to observations made in the stockwork of present-day long-lived oceanic hydrothermal systems.

  10. Class voting in Western industrialized countries, 1945-1990: Systematizing and testing explanations

    NARCIS (Netherlands)

    Nieuwbeerta, P.; Ultee, W.C.

    1999-01-01

    Analyzing data obtained from the literature and our own calculations, significant differences were found among countries in their levels of class voting. The Scandinavian countries had the highest and Canada and the USA the lowest levels of class voting. Since the 1950s, there was a decline in

  11. Honesty, trust and economic growth - A cross-cultural comparison of western industrialized countries

    NARCIS (Netherlands)

    Fetchenhauer, D; van der Vegt, G

    This article investigates cross-country differences in economic growth rates from a psychological perspective. Based on social capital theory it is argued that 1) financial honesty and trust are positively correlated with each other when they are aggregated on a country level and that 2) a high

  12. Nurse prescribing of medicines in Western European and Anglo-Saxon countries: a survey on forces, conditions and jurisdictional control.

    Science.gov (United States)

    Kroezen, Marieke; Francke, Anneke L; Groenewegen, Peter P; van Dijk, Liset

    2012-08-01

    The number of Western European and Anglo-Saxon countries where nurses are legally allowed to prescribe medicines is growing. As the prescribing of medicines has traditionally been the task of the medical profession, nurse prescribing is changing the relationship between the medical and nursing professions. To gain more insight into the forces that led to the introduction of nurse prescribing of medicines in Western European and Anglo-Saxon countries, as well as into the legal, educational and organizational conditions under which nurses prescribe in these countries. Moreover, this study sought to determine which consequences nurse prescribing has for the division of jurisdictional control over prescribing between the nursing and medical professions. International survey. An email survey was sent to 60 stakeholders of professional nursing or medical associations or government bodies, at national, state or provincial level across ten Western European and Anglo-Saxon countries, namely Australia, Canada, Finland, Ireland, the Netherlands, New Zealand, Spain, Sweden, the United Kingdom and the United States of America. The survey addressed the reasons for the introduction of nurse prescribing and the conditions under which nurses are or will be prescribing medicines. The response rate was 65% (n=39). It was shown that a diversity of forces led to the introduction of nurse prescribing, and respondents from nursing and medical associations and government bodies cited different forces as being important for the introduction of nurse prescribing. Representatives of nurses' associations oftentimes emphasized the medication needs of patients living in remote geographical areas, while representatives of medical associations more often pointed to workforce shortages within the health care service. The conditions under which nurses prescribe medicines vary considerably, from countries where nurses prescribe independently to countries in which prescribing by nurses is only

  13. Birth weight and perinatal mortality: A comparison of "optimal" birth weight in seven western European countries

    NARCIS (Netherlands)

    Graafmans, W.C.; Richardus, J.H.; Borsboom, G.J.J.M.; Bakketeig, L.; Langhoff-Roos, J.; Bergsjø, P.; Macfarlane, A.; Verloove-Vanhorick, P.; Mackenbach, J.; Aelvoet, W.; Alderdice, F.; Amelink, M.; Bakoula, C.; Blondel, B.; Bødker, B.; Bolumar, F.; Davidson, L.; Gissler, M.; Hartikainen, A.L.; Holt, J.; Kaminski, M.; Leidinger, J.; Lekea, V.; Lindmark, G.; Masuy-Stroobant, G.; Pal, K. van der; Penney, G.; Purificação Araújo, M. Da; Rantakallio, P.; Rebagliato, M.

    2002-01-01

    Background. Previous studies have suggested that a population's entire birth weight distribution may be shifted towards higher or lower birth weights, and that optimal birth weight may be lower in populations with a lower average birth weight. We evaluated this hypothesis for seven western European

  14. From Tegucigalpa to Teheran: Brazil's diplomacy as an emerging Western country

    Directory of Open Access Journals (Sweden)

    Andrea Quirino Steiner

    2014-01-01

    Full Text Available This paper reviews Brazil's pursuit for international insertion by: discussing its search for new partners; presenting an overview of the historical, cultural, and political features that render it the most Western of the emerging nations; and analyzing its participation in the management of two major international crises, the Honduran constitutional crisis and the Iranian nuclear crisis.

  15. Nurse prescribing of medicines in Western European and Anglo-Saxon countries: a systematic review of the literature.

    Science.gov (United States)

    Kroezen, Marieke; van Dijk, Liset; Groenewegen, Peter P; Francke, Anneke L

    2011-05-27

    A growing number of countries are introducing some form of nurse prescribing. However, international reviews concerning nurse prescribing are scarce and lack a systematic and theoretical approach. The aim of this review was twofold: firstly, to gain insight into the scientific and professional literature describing the extent to and the ways in which nurse prescribing has been realised or is being introduced in Western European and Anglo-Saxon countries; secondly, to identify possible mechanisms underlying the introduction and organisation of nurse prescribing on the basis of Abbott's theory on the division of professional labor. A comprehensive search of six literature databases and seven websites was performed without any limitation as to date of publication, language or country. Additionally, experts in the field of nurse prescribing were consulted. A three stage inclusion process, consisting of initial sifting, more detailed selection and checking full-text publications, was performed independently by pairs of reviewers. Data were synthesized using narrative and tabular methods. One hundred and twenty-four publications met the inclusion criteria. So far, seven Western European and Anglo-Saxon countries have implemented nurse prescribing of medicines, viz., Australia, Canada, Ireland, New Zealand, Sweden, the UK and the USA. The Netherlands and Spain are in the process of introducing nurse prescribing. A diversity of external and internal forces has led to the introduction of nurse prescribing internationally. The legal, educational and organizational conditions under which nurses prescribe medicines vary considerably between countries; from situations where nurses prescribe independently to situations in which prescribing by nurses is only allowed under strict conditions and supervision of physicians. Differences between countries are reflected in the jurisdictional settlements between the nursing and medical professions concerning prescribing. In some

  16. Pharmacological treatment for attention deficit hyperactivity disorder: functional outcomes in children and adolescents from non-Western countries

    Directory of Open Access Journals (Sweden)

    Murat Altin

    2013-09-01

    Full Text Available Objective: Functional outcomes were measured over a 12-month period in children and adolescents with attention deficit hyperactivity disorder (ADHD after they received monotherapy. Design: Prospective, observational, noninterventional study. Setting: Conducted in six non-Western countries. Participants: Outpatients 6 to 17 years of age with a verified diagnosis of ADHD in accordance with the Diagnostic and Statistical Manual, Fourth Edition, Text Revision (DSM-IV-TR, together with their physicians, decided to initiate or switch treatment for ADHD. Patients were prescribed pharmacological monotherapy: methylphenidate (n=221, nootropic agents (n=91, or atomoxetine (n=234. Measurements: Patients were followed for changes in their functional status and quality of life, which were assessed with the Child Health and Illness Profile–Child Edition (CHIPCE Achievement domain. Results: At the end of the study, a mean improvement on the CHIP-CE Achievement domain score was observed for all countries and therapies except in Taiwan, where patients received atomoxetine, and in Lebanon, where patients received methylphenidate. No patient experienced a serious adverse event during the study. Four patients discontinued due to a treatment-emergent adverse event. Conclusion: After 12 months of treatment, clinical and functional outcomes were improved in children and adolescents from non-Western countries who initiated and remained on their prescribed pharmacological monotherapy.

  17. Pharmacological treatment for attention deficit hyperactivity disorder: functional outcomes in children and adolescents from non-Western countries.

    Science.gov (United States)

    Altin, Murat; El-Shafei, Ahmed A; Yu, Maria; Desaiah, Durisala; Treuer, Tamas; Zavadenko, Nikolay; Gao, Hong Yun

    2013-09-13

    Functional outcomes were measured over a 12-month period in children and adolescents with attention deficit hyperactivity disorder (ADHD) after they received monotherapy. Prospective, observational, noninterventional study. Conducted in six non-Western countries. Outpatients 6 to 17 years of age with a verified diagnosis of ADHD in accordance with the Diagnostic and Statistical Manual, Fourth Edition, Text Revision (DSM-IV-TR), together with their physicians, decided to initiate or switch treatment for ADHD. Patients were prescribed pharmacological monotherapy: methylphenidate (n=221), nootropic agents (n=91), or atomoxetine (n=234). Patients were followed for changes in their functional status and quality of life, which were assessed with the Child Health and Illness Profile-Child Edition (CHIP-CE) Achievement domain. At the end of the study, a mean improvement on the CHIP-CE Achievement domain score was observed for all countries and therapies except in Taiwan, where patients received atomoxetine, and in Lebanon, where patients received methylphenidate. No patient experienced a serious adverse event during the study. Four patients discontinued due to a treatment-emergent adverse event. After 12 months of treatment, clinical and functional outcomes were improved in children and adolescents from non-Western countries who initiated and remained on their prescribed pharmacological monotherapy.

  18. Peer victimization and subjective health among students reporting disability or chronic illness in 11 Western countries

    DEFF Research Database (Denmark)

    Sentenac, Mariane; Gavin, Aoife; Nic Gabhainn, Saoirse

    2013-01-01

    BACKGROUND: To compare the strength of the association between peer victimization at school and subjective health according to the disability or chronic illness (D/CI) status of students across countries. METHODS: This study used data from 55 030 students aged 11, 13 and 15 years from 11 countries...... reporting D/CI were more likely to report being victims of bullying. Victims of bullying reported more negative subjective health outcomes regardless of their D/CI status. Although inclusive education is currently a major topic of educational policies in most countries, additional efforts should be made...

  19. Contextual explanations for numeracy and literacy skill disparities between native and foreign-born adults in western countries.

    Directory of Open Access Journals (Sweden)

    Mark Levels

    Full Text Available Using new direct measures of numeracy and literacy skills among 85,875 adults in 17 Western countries, we find that foreign-born adults have lower mean skills than native-born adults of the same age (16 to 64 in all of the examined countries. The gaps are small, and vary substantially between countries. Multilevel models reveal that immigrant populations' demographic and socioeconomic characteristics, employment, and language proficiency explain about half of the cross-national variance of numeracy and literacy skills gaps. Differences in origin countries' average education level also account for variation in the size of the immigrant-native skills gap. The more protective labor markets in immigrant-receiving countries are, the less well immigrants are skilled in numeracy and literacy compared to natives. For those who migrate before their teens (the 1.5 generation, access to an education system that accommodates migrants' special needs is crucial. The 1 and 1.5 generation have smaller numeracy and literacy skills gaps in more ethnically diverse societies.

  20. Peer victimization and subjective health among students reporting disability or chronic illness in 11 Western countries.

    Science.gov (United States)

    Sentenac, Mariane; Gavin, Aoife; Gabhainn, Saoirse Nic; Molcho, Michal; Due, Pernille; Ravens-Sieberer, Ulrike; Matos, Margarida Gaspar de; Malkowska-Szkutnik, Agnieszka; Gobina, Inese; Vollebergh, Wilma; Arnaud, Catherine; Godeau, Emmanuelle

    2013-06-01

    To compare the strength of the association between peer victimization at school and subjective health according to the disability or chronic illness (D/CI) status of students across countries. This study used data from 55 030 students aged 11, 13 and 15 years from 11 countries participating in the 2005-06 Health Behaviour in School-aged Children survey. Self-completed questionnaires were administered in classrooms. Multivariate models of logistic regression (controlled for confounding factors and countries) were used to investigate differences in the association between peer victimization and poor subjective health according to the D/CI status. Overall, 13.5% of the students reported having been bullied at least two or three times a month. The percentage of victims was significantly higher among those reporting D/CI than among others in all countries studied. Victims of bullying were more likely to report poor self-rated health, low life satisfaction and multiple health complaints. However, there were no differences in the associations between peer victimization and subjective health indicators according to the D/CI status. In all countries studied, students reporting D/CI were more likely to report being victims of bullying. Victims of bullying reported more negative subjective health outcomes regardless of their D/CI status. Although inclusive education is currently a major topic of educational policies in most countries, additional efforts should be made to improve the quality of the integration of students with D/CI.

  1. The influence of cultural differences between China and Western countries on cross-cultural communication

    Institute of Scientific and Technical Information of China (English)

    次仁德吉

    2017-01-01

    Cross-cultural communication refers to the communication between peoples of different cultural backgrounds. To solve and avoid the cultural conflicts and blocks, it is high time to enhance the actual skills of cross-cultural communication. This paper gives a comparative analysis of the concrete representations of differences between Chinese and western culture in cross-cultural communication. And it gives some communication principles on the cross-cultural communication.

  2. Western-style fast food intake and cardiometabolic risk in an Eastern country.

    Science.gov (United States)

    Odegaard, Andrew O; Koh, Woon Puay; Yuan, Jian-Min; Gross, Myron D; Pereira, Mark A

    2012-07-10

    Western-style fast food contributes to a dietary pattern portending poor cardiometabolic health in the United States. With globalization, this way of eating is becoming more common in developing and recently developed populations. We examined the association of Western-style fast food intake with risk of incident type 2 diabetes mellitus and coronary heart disease mortality in Chinese Singaporeans. This analysis included men and women 45 to 74 years of age who enrolled in the Singapore Chinese Health Study from 1993 to 1998. For CHD mortality, 52 584 participants were included and 1397 deaths were identified through December 31, 2009, via registry linkage. For type 2 diabetes mellitus, 43 176 participants were included and 2252 cases were identified during the follow-up interview (1999-2004) and validated. Hazard ratios for incident type 2 diabetes mellitus and coronary heart disease mortality were estimated with thorough adjustment for demographic, lifestyle, and dietary factors. Chinese Singaporeans with relatively frequent intake of Western-style fast food items (≥2 times per week) had an increased risk of developing type 2 diabetes mellitus (hazard ratio, 1.27; 95% confidence interval, 1.03-1.54) and dying of coronary heart disease (hazard ratio, 1.56; 95% confidence interval, 1.18-2.06) relative to their peers with little or no reported intake. These associations were not materially altered by adjustments for overall dietary pattern, energy intake, and body mass index. Western-style fast food intake is associated with increased risk of developing type 2 diabetes mellitus and of coronary heart disease mortality in an Eastern population. These findings suggest the need for further attention to global dietary acculturation in the context of ongoing epidemiological and nutrition transitions.

  3. Western-Style Fast Food Intake and Cardiometabolic Risk in an Eastern Country

    Science.gov (United States)

    Odegaard, Andrew O.; Koh, Woon Puay; Yuan, Jian-Min; Gross, Myron D.; Pereira, Mark A.

    2014-01-01

    Background Western-style fast food contributes to a dietary pattern portending poor cardiometabolic health in the United States. With globalization, this way of eating is becoming more common in developing and recently developed populations. Methods and Results We examined the association of Western-style fast food intake with risk of incident type 2 diabetes mellitus and coronary heart disease mortality in Chinese Singaporeans. This analysis included men and women 45 to 74 years of age who enrolled in the Singapore Chinese Health Study from 1993 to 1998. For CHD mortality, 52 584 participants were included and 1397 deaths were identified through December 31, 2009, via registry linkage. For type 2 diabetes mellitus, 43 176 participants were included and 2252 cases were identified during the follow-up interview (1999 –2004) and validated. Hazard ratios for incident type 2 diabetes mellitus and coronary heart disease mortality were estimated with thorough adjustment for demographic, lifestyle, and dietary factors. Chinese Singaporeans with relatively frequent intake of Western-style fast food items (≥2 times per week) had an increased risk of developing type 2 diabetes mellitus (hazard ratio, 1.27; 95% confidence interval, 1.03–1.54) and dying of coronary heart disease (hazard ratio, 1.56; 95% confidence interval, 1.18 –2.06) relative to their peers with little or no reported intake. These associations were not materially altered by adjustments for overall dietary pattern, energy intake, and body mass index. Conclusions Western-style fast food intake is associated with increased risk of developing type 2 diabetes mellitus and of coronary heart disease mortality in an Eastern population. These findings suggest the need for further attention to global dietary acculturation in the context of ongoing epidemiological and nutrition transitions. PMID:22753304

  4. Access to information on nuclear safety in some Western countries. Additional expertise commissioned by the Public Debate National Commission

    International Nuclear Information System (INIS)

    Marignac, Y.; Schneider, Th.; Drouet, F.

    2006-01-01

    The authors report the analysis of procedures implemented in different western countries (Switzerland, Finland, United Kingdom, Germany, Sweden and United States) about the access to information on nuclear safety in the broad sense, i.e. as far as population protection against accidental or malevolent situations is concerned. They aimed at analysing how these procedures conciliate pluralism and comprehensive debate while preserving national and industrial interests as well as population's confidence. For each country, they present the different pubic bodies or agencies in charge of nuclear installations and nuclear safety, the existing legal framework related to information on government and nuclear activities, and give examples of information related to nuclear safety (incident or accident concerning nuclear power station or radioactive wastes). The comparative analysis considers different issues: access to information, and pluralist expertise

  5. Strangers in strange lands: a metasynthesis of lived experiences of immigrant asian nurses working in Western countries.

    Science.gov (United States)

    Xu, Yu

    2007-01-01

    Nurses from Asian countries make up the majority of immigrant nurses globally. Although there are a limited number of studies on the lived experiences of Asian nurses working in Western countries, the development of nursing science will be impeded if the rich understanding gleaned from these studies is not synthesized. Using Noblit and Hare's (Meta-ethnography: Synthesizing Qualitative Studies. Newbury Park, Calif: Sage; 1988) procedures, a metasynthesis was conducted on 14 studies that met preset selection criteria. Four overarching themes emerged: (a) communication as a daunting challenge; (b) differences in nursing practice; (c) marginalization, discrimination, and exploitation; and (d) cultural differences. Based on the metasynthesis, a large narrative and expanded interpretation was constructed and implications for nursing knowledge development, clinical practice, and policy making are elaborated.

  6. Who Decides: Me or We? Family Involvement in Medical Decision Making in Eastern and Western Countries.

    Science.gov (United States)

    Alden, Dana L; Friend, John; Lee, Ping Yein; Lee, Yew Kong; Trevena, Lyndal; Ng, Chirk Jenn; Kiatpongsan, Sorapop; Lim Abdullah, Khatijah; Tanaka, Miho; Limpongsanurak, Supanida

    2018-01-01

    Research suggests that desired family involvement (FI) in medical decision making may depend on cultural values. Unfortunately, the field lacks cross-cultural studies that test this assumption. As a result, providers may be guided by incomplete information or cultural biases rather than patient preferences. Researchers developed 6 culturally relevant disease scenarios varying from low to high medical seriousness. Quota samples of approximately 290 middle-aged urban residents in Australia, China, Malaysia, India, South Korea, Thailand, and the USA completed an online survey that examined desired levels of FI and identified individual difference predictors in each country. All reliability coefficients were acceptable. Regression models met standard assumptions. The strongest finding across all 7 countries was that those who desired higher self-involvement (SI) in medical decision making also wanted lower FI. On the other hand, respondents who valued relational-interdependence tended to want their families involved - a key finding in 5 of 7 countries. In addition, in 4 of 7 countries, respondents who valued social hierarchy desired higher FI. Other antecedents were less consistent. These results suggest that it is important for health providers to avoid East-West cultural stereotypes. There are meaningful numbers of patients in all 7 countries who want to be individually involved and those individuals tend to prefer lower FI. On the other hand, more interdependent patients are likely to want families involved in many of the countries studied. Thus, individual differences within culture appear to be important in predicting whether a patient desires FI. For this reason, avoiding culture-based assumptions about desired FI during medical decision making is central to providing more effective patient centered care.

  7. Labour Market Institutions in the Western Balkan Countries and their Economic Implications: Evidence for Kosova

    OpenAIRE

    MSc. Anera Alishani; BA. Ariana Shabani; Dr.Sc. Muje Gjonbalaj

    2013-01-01

    Flexicurity as one of the most important priorities of employment policies in the EU and its Member States is considered to be also important for the other states of Central and Eastern Europe, including the Western Balkans. According to European Commission (2007, p.7), flexicurity as a combination of flexibility and security in working arrangements can be suggested as an answer to dynamic changes happening in today’s national and international economies; it is an answer to the EU’s dilemma o...

  8. Contextual explanations for numeracy and literacy skill disparities between native and foreign-born adults in western countries

    Science.gov (United States)

    Jencks, Christopher

    2017-01-01

    Using new direct measures of numeracy and literacy skills among 85,875 adults in 17 Western countries, we find that foreign-born adults have lower mean skills than native-born adults of the same age (16 to 64) in all of the examined countries. The gaps are small, and vary substantially between countries. Multilevel models reveal that immigrant populations’ demographic and socioeconomic characteristics, employment, and language proficiency explain about half of the cross-national variance of numeracy and literacy skills gaps. Differences in origin countries’ average education level also account for variation in the size of the immigrant-native skills gap. The more protective labor markets in immigrant-receiving countries are, the less well immigrants are skilled in numeracy and literacy compared to natives. For those who migrate before their teens (the 1.5 generation), access to an education system that accommodates migrants’ special needs is crucial. The 1 and 1.5 generation have smaller numeracy and literacy skills gaps in more ethnically diverse societies. PMID:28301541

  9. Large-Scale Preventive Chemotherapy for the Control of Helminth Infection in Western Pacific Countries: Six Years Later

    Science.gov (United States)

    Montresor, Antonio; Cong, Dai Tran; Sinuon, Mouth; Tsuyuoka, Reiko; Chanthavisouk, Chitsavang; Strandgaard, Hanne; Velayudhan, Raman; Capuano, Corinne M.; Le Anh, Tuan; Tee Dató, Ah S.

    2008-01-01

    In 2001, Urbani and Palmer published a review of the epidemiological situation of helminthiases in the countries of the Western Pacific Region of the World Health Organization indicating the control needs in the region. Six years after this inspiring article, large-scale preventive chemotherapy for the control of helminthiasis has scaled up dramatically in the region. This paper analyzes the most recent published and unpublished country information on large-scale preventive chemotherapy and summarizes the progress made since 2000. Almost 39 million treatments were provided in 2006 in the region for the control of helminthiasis: nearly 14 million for the control of lymphatic filariasis, more than 22 million for the control of soil-transmitted helminthiasis, and over 2 million for the control of schistosomiasis. In general, control of these helminthiases is progressing well in the Mekong countries and Pacific Islands. In China, despite harboring the majority of the helminth infections of the region, the control activities have not reached the level of coverage of countries with much more limited financial resources. The control of food-borne trematodes is still limited, but pilot activities have been initiated in China, Lao People's Democratic Republic, and Vietnam. PMID:18846234

  10. Options of biofuel trade from Central and Eastern to Western European countries

    NARCIS (Netherlands)

    van Dam, J.; Faaij, A.P.C.; Lewandowski, I.M.; Van Zeebroeck, B.

    2009-01-01

    Central and Eastern European countries (CEEC) have a substantial biomass production and export potential. The objective of this study is to assess whether the market for biofuels and trade can be profitable enough to realize a supply of biofuels from the CEEC to the European market and to estimate

  11. Interethnic contacts : a dynamic analysis of interaction between immigrants and natives in Western countries

    NARCIS (Netherlands)

    Martinovic, B.

    2010-01-01

    This book studies social integration of immigrants (i.e. contacts between immigrants and natives in leisure time) from a dynamic perspective. The central objective is to examine how such interethnic contacts change during the immigrants’ stay in the host country (do they increase, stagnate or

  12. The fractal research on several large stock market in China and western country

    Directory of Open Access Journals (Sweden)

    QU Bo

    2012-10-01

    Full Text Available The R/S method of the fractal theory was used in analysis the most influential stock markets in China ( Shanghai Composite Index-SSEC, the Shenzhen Composite Index-SZCI and Hang Seng Index-HSI in HongKong and the most impact foreign stock markets ( the Dow Jones, the Nasdaq and the S&P 500 in recent 10 years ( 2002-2011 stock index to study their differences. The Hurst exponent for the logarithmic rate of monthly return for Chinese stock markets were around 0.74,while the Hurst exponent for the western were around 0.77. The average cycle for Chinese stock markets were around 600 days,while westerns were around 1150 days. The price of the Dow Jones index had a greater influence on the price of SSEC than other markets, and HSI had a greater influence on SSCI than SSEC. Chinese and foreign markets had higher kurtosis than normal distribution, and during the first one or two cycle, the price data presented a right-skewed,peak and fat-tailed distribution characteristics. The data presented a left-skewed,peak and fat-tailed distribution afterwards. At the same time, the foreign data is much closer to normal distribution. This research is a good guidance for stock researcher understanding and studying the foreign stock markets.

  13. Rectal Tumour Staging with Endorectal Ultrasound: Is There Any Difference between Western and Eastern European Countries?

    Science.gov (United States)

    Fábián, Anna; Bor, Renáta; Farkas, Klaudia; Bálint, Anita; Milassin, Ágnes; Rutka, Mariann; Tiszlavicz, László; Wittmann, Tibor; Nagy, Ferenc; Molnár, Tamás; Szepes, Zoltán

    2016-01-01

    Background. Rectal tumour management depends highly on locoregional extension. Rectal endoscopic ultrasound (ERUS) is a good alternative to computed tomography and magnetic resonance imaging. However, in Hungary only a small amount of rectal tumours is examined with ERUS. Methods. Our retrospective study (2006-2012) evaluates the diagnostic accuracy of ERUS and compares the results, the first data from Central Europe, with those from Western Europe. The effect of neoadjuvant therapy, rectal probe type, and investigator's experience were also assessed. Results. 311 of the 647 ERUS assessed locoregional extension. Histological comparison was available in 177 cases: 67 patients underwent surgery alone; 110 received neoadjuvant chemoradiotherapy (CRT); ERUS preceded CRT in 77 and followed it in 33 patients. T-staging was accurate in 72% of primarily operated patients. N-staging was less accurate (62%). CRT impaired staging accuracy (64% and 59% for T- and N-staging). Rigid probes were more accurate (79%). At least 30 examinations are needed to master the technique. Conclusions. The sensitivity of ERUS complies with the literature. ERUS is easy to learn and more accurate in early stages but unnecessary for restaging after CRT. Staging accuracy is similar in Western and Central Europe, although the number of examinations should be increased.

  14. Cement Formation

    DEFF Research Database (Denmark)

    Telschow, Samira; Jappe Frandsen, Flemming; Theisen, Kirsten

    2012-01-01

    Cement production has been subject to several technological changes, each of which requires detailed knowledge about the high multiplicity of processes, especially the high temperature process involved in the rotary kiln. This article gives an introduction to the topic of cement, including...... an overview of cement production, selected cement properties, and clinker phase relations. An extended summary of laboratory-scale investigations on clinkerization reactions, the most important reactions in cement production, is provided. Clinker formations by solid state reactions, solid−liquid and liquid......−liquid reactions are discussed, as are the influences of particles sizes on clinker phase formation. Furthermore, a mechanism for clinker phase formation in an industrial rotary kiln reactor is outlined....

  15. (De)centralization of social support in six Western European countries.

    Science.gov (United States)

    Kroneman, Madelon; Cardol, Mieke; Friele, Roland

    2012-06-01

    Participation of disabled or chronically ill persons into the society may require support in the sense of human or technical aid. In this study we look into the decision making power of governments and the way citizens are involved in these processes. Decision making power can be political, financial and administrative and may be organized at national, regional or local level. This is a cross-sectional descriptive study of the decision making power in Belgium, France, Germany, the Netherlands, Sweden and the United Kingdom in 2010. We focused on acts and regulations for human and technical aids and for making the environment accessible. Several acts and regulations were identified in relation to social support. In the Netherlands and Sweden social support was mainly organized in one act, whereas in the other countries social support was part of several acts or regulations. Citizen's voice appeared to be represented in boards or advisory committees. Descriptions of entitlements varied from explicitly formulated to globally described. The level of decision making power varies between the countries en between the types of decision making power. Citizens' participation is mainly represented through patient associations. Countries with strongly decentralized decision making make use of framework legislation at national level to set general targets or aims. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  16. The prevalence of mental disorders among the homeless in western countries: systematic review and meta-regression analysis.

    Directory of Open Access Journals (Sweden)

    Seena Fazel

    2008-12-01

    Full Text Available BACKGROUND: There are well over a million homeless people in Western Europe and North America, but reliable estimates of the prevalence of major mental disorders among this population are lacking. We undertook a systematic review of surveys of such disorders in homeless people. METHODS AND FINDINGS: We searched for surveys of the prevalence of psychotic illness, major depression, alcohol and drug dependence, and personality disorder that were based on interviews of samples of unselected homeless people. We searched bibliographic indexes, scanned reference lists, and corresponded with authors. We explored potential sources of any observed heterogeneity in the estimates by meta-regression analysis, including geographical region, sample size, and diagnostic method. Twenty-nine eligible surveys provided estimates obtained from 5,684 homeless individuals from seven countries. Substantial heterogeneity was observed in prevalence estimates for mental disorders among the studies (all Cochran's chi(2 significant at p 85%. The most common mental disorders were alcohol dependence, which ranged from 8.1% to 58.5%, and drug dependence, which ranged from 4.5% to 54.2%. For psychotic illness, the prevalence ranged from 2.8% to 42.3%, with similar findings for major depression. The prevalence of alcohol dependence was found to have increased over recent decades. CONCLUSIONS: Homeless people in Western countries are substantially more likely to have alcohol and drug dependence than the age-matched general population in those countries, and the prevalences of psychotic illnesses and personality disorders are higher. Models of psychiatric and social care that can best meet these mental health needs requires further investigation.

  17. The Prevalence of Mental Disorders among the Homeless in Western Countries: Systematic Review and Meta-Regression Analysis

    Science.gov (United States)

    Fazel, Seena; Khosla, Vivek; Doll, Helen; Geddes, John

    2008-01-01

    Background There are well over a million homeless people in Western Europe and North America, but reliable estimates of the prevalence of major mental disorders among this population are lacking. We undertook a systematic review of surveys of such disorders in homeless people. Methods and Findings We searched for surveys of the prevalence of psychotic illness, major depression, alcohol and drug dependence, and personality disorder that were based on interviews of samples of unselected homeless people. We searched bibliographic indexes, scanned reference lists, and corresponded with authors. We explored potential sources of any observed heterogeneity in the estimates by meta-regression analysis, including geographical region, sample size, and diagnostic method. Twenty-nine eligible surveys provided estimates obtained from 5,684 homeless individuals from seven countries. Substantial heterogeneity was observed in prevalence estimates for mental disorders among the studies (all Cochran's χ2 significant at p 85%). The most common mental disorders were alcohol dependence, which ranged from 8.1% to 58.5%, and drug dependence, which ranged from 4.5% to 54.2%. For psychotic illness, the prevalence ranged from 2.8% to 42.3%, with similar findings for major depression. The prevalence of alcohol dependence was found to have increased over recent decades. Conclusions Homeless people in Western countries are substantially more likely to have alcohol and drug dependence than the age-matched general population in those countries, and the prevalences of psychotic illnesses and personality disorders are higher. Models of psychiatric and social care that can best meet these mental health needs requires further investigation. PMID:19053169

  18. A macro-sociological study into the changes in the popularity of domestic, European, and American pop music in Western countries

    NARCIS (Netherlands)

    Bekhuis, H.; Lubbers, M.; Ultee, W.C.

    2014-01-01

    Relying on the top 100 pop songs from year-end charts, we coded more than 30,000 chart positions based on the country of origin of the artist and the language of performance, in nine Western countries. We estimated cross-national differences and trends since 1973, testing expectations on

  19. Viewls - Possibilities and performance of international biofuel trade from CEEC to WEC[Central and Eastern European Countries; Western European Countries

    Energy Technology Data Exchange (ETDEWEB)

    Dam, J. van; Faaij, A.; Lewandowski, I. [Utrecht Univ., Dept. of Science, Technology and Society, Utrecht (Netherlands); Zeebroeck, B. van [Transport and Mobility Leuven, Leuven (Belgium); Falkenberg, D.; Hein, M.; Schroeder, G.; Thraen, D.; Weber, M. [Inst. of Energy and Environment, Leipzig (Germany)

    2006-05-13

    The EU has set high targets to increase the use of renewable energy sources from which a large part has to come from biomass. To meet these targets, a large amount of biomass resources is needed, which requires large areas of land in the EU for energy crop production. However, the availability of good land for energy crop production is limited in Western European countries (WEC). This means that the potential from indigenous biomass resources is not sufficient to meet the set bioenergy targets. At the same time, the expansion of the EU and the inclusion of the Central and Eastern European countries (CEEC) in agricultural and energy EU policies create potential difficulties as well as opportunities. Agriculture plays an important role in the CEEC furthermore, the share of agricultural employment is still large. In the future rationalization of the current agriculture in the CEEC is expected. This will lead to increased productivity and economic performance. On the other hand, unemployment and an increase in abandoned land are expected as well. A study of the technical biomass production potentials in the CEEC shows that in some scenarios the biomass production potential exceeds the current final energy consumption on a country level. The main objectives of this study are: 1) Define the critical factors to set up a stable international biofuel trade between CEEC and WEC, 2) Estimate the cost performance of the energy carriers delivered in the WEC from the CEEC, 3) Analyze the regional differences in cost performance of the energy carriers in the CEEC. (BA)

  20. Questionnaire-based survey on the distribution and incidence of canine babesiosis in countries of Western Europe

    Directory of Open Access Journals (Sweden)

    Halos Lénaïg

    2014-01-01

    Full Text Available The incidence of canine babesiosis may vary considerably from one country to another depending on the distribution of the causative parasite species and their specific vectors. The aim of the present study was to evaluate the clinical occurrence of canine babesiosis diagnosed in European veterinary clinics and propose an updated map of the disease distribution in Western Europe. Questionnaires were sent to companion animal veterinary clinics in Spain, France, Benelux, Germany and Austria. The annual number of babesiosis cases in 2010, the number of practitioners in the clinic and the location of the clinic were recorded. The total numbers of dogs and practitioners in each country were used for definition of the reference populations and the annual incidence of canine babesiosis was calculated by dividing the total number of reported babesiosis cases by the total number of dogs in the veterinary practices involved in the study. Data were georeferenced for distribution map construction. The overall annual incidence of clinical babesiosis amongst the investigated dog population was 0.7%, with significant variations amongst countries and regions. Three epidemiological situations were described: (i Spain, with co-existence of several species of piroplasms and patchy distribution of babesiosis, (ii France, with overall presence of babesiosis due to Babesia canis and local variations and (iii Benelux, Germany and Austria, with overall low prevalence of the disease associated with localised description related either to imported cases or to small autochthonous foci of B. canis infection.

  1. Questionnaire-based survey on the distribution and incidence of canine babesiosis in countries of Western Europe

    Science.gov (United States)

    Halos, Lénaïg; Lebert, Isabelle; Abrial, David; Danlois, Fabien; Garzik, Karin; Rodes, Daniel; Schillmeier, Monika; Ducrot, Christian; Guillot, Jacques

    2014-01-01

    The incidence of canine babesiosis may vary considerably from one country to another depending on the distribution of the causative parasite species and their specific vectors. The aim of the present study was to evaluate the clinical occurrence of canine babesiosis diagnosed in European veterinary clinics and propose an updated map of the disease distribution in Western Europe. Questionnaires were sent to companion animal veterinary clinics in Spain, France, Benelux, Germany and Austria. The annual number of babesiosis cases in 2010, the number of practitioners in the clinic and the location of the clinic were recorded. The total numbers of dogs and practitioners in each country were used for definition of the reference populations and the annual incidence of canine babesiosis was calculated by dividing the total number of reported babesiosis cases by the total number of dogs in the veterinary practices involved in the study. Data were georeferenced for distribution map construction. The overall annual incidence of clinical babesiosis amongst the investigated dog population was 0.7%, with significant variations amongst countries and regions. Three epidemiological situations were described: (i) Spain, with co-existence of several species of piroplasms and patchy distribution of babesiosis, (ii) France, with overall presence of babesiosis due to Babesia canis and local variations and (iii) Benelux, Germany and Austria, with overall low prevalence of the disease associated with localised description related either to imported cases or to small autochthonous foci of B. canis infection. PMID:24626325

  2. Public sector refraction and spectacle dispensing in low-resource countries of the Western Pacific.

    Science.gov (United States)

    Ramke, Jacqueline; du Toit, Rènée; Palagyi, Anna; Williams, Carmel; Brian, Garry

    2008-05-01

    Given that uncorrected refractive error is a frequent cause of vision impairment, and that there is a high unmet need for spectacles, an appraisal of public sector arrangements for the correction of refractive error was conducted in eight Pacific Island countries. Mixed methods (questionnaire and semi-structured interviews) were used to collect information from eye care personnel (from Fiji, Papua New Guinea, Solomon Islands, Vanuatu, Cook Islands, Samoa, Tonga and Tuvalu) attending a regional eye health workshop in 2005. Fiji, Tonga and Vanuatu had Vision 2020 eye care plans that included refraction services, but not spectacle provision. There was wide variation in public sector spectacle dispensing services, but, except in Samoa, ready-made spectacles and a full cost recovery pricing strategy were the mainstay. There were no systems for the registration of personnel, nor guidelines for clinical or systems management. The refraction staff to population ratio varied considerably. Solomon Islands, Tuvalu and Vanuatu had the best coverage by services, either fixed or outreach. Most services had little promotional activity or community engagement. To be successful, it would seem that public sector refraction services should answer a real and perceived need, fit within prevailing policy and legislation, value, train, retain and equip employees, be well managed, be accessible and affordable, be responsive to consumers, and provide ongoing good quality outcomes. To this end, a checklist to aid the initiation and maintenance of refraction and spectacle systems in low-resource countries has been constructed.

  3. Parenting and globalization in western countries: explaining differences in parent-child interactions.

    Science.gov (United States)

    Prevoo, Mariëlle Jl; Tamis-LeMonda, Catherine S

    2017-06-01

    We review research on intra-cultural differences in parenting, and the sources of those differences. Ethnic-minority parents differ from majority parents in parenting values, childrearing goals and resources-differences that affect parenting practices and children's development. Within-country comparisons indicate less sensitivity, more authoritarian discipline, less child-focused communications, and less engagement in learning activities in ethnic-minority compared to ethnic-majority parents, which help account for disparities in children. Despite group differences in parenting, associations between parenting and child development generalize across cultures, with rare exceptions. However, a focus on intra-cultural differences is based on comparisons of group 'averages', which masks the enormous variation within ethnic-minority samples. Within-group variation can be partly explained by stressors associated with low socioeconomic status (SES), acculturation and discrimination. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Leadership for child health in the developing countries of the Western Pacific

    Science.gov (United States)

    Subhi, Rami; Duke, Trevor

    2011-01-01

    The content and landscape of global child health is increasingly complex. There is strong evidence for the effectiveness of local, national and institutional leadership in reducing child mortality, but this has not been a focus of global health initiatives. Interventions to strengthen health systems should include support for local leadership: building-up institutions of training, empowering national paediatric professional associations, creating opportunities for contribution and leadership at national, provincial and local level, and networks of support for staff working in child health in remote areas. In the poorer high mortality burden countries of the Pacific, to meet the clinical and public health gaps, there is a need for increases in the education of child health nurse practitioners, and development of systems of continuing professional development for paediatric doctors and nurses. Involvement in local research, especially that which contributes directly to critical issues in child health policy or strengthening national data systems builds capacity for leadership. PMID:23198107

  5. Leadership for child health in the developing countries of the Western Pacific

    Directory of Open Access Journals (Sweden)

    Rami Subhi

    2011-06-01

    Full Text Available The content and landscape of global child health is increasingly complex. There is strong evidence for the effectiveness of local, national and institutional leadership in reducing child mortality, but this has not been a focus of global health initiatives. Interventions to strengthen health systems should include support for local leadership: building-up institutions of training, empowering national paediatric professional associations, creating opportunities for contribution and leadership at national, provincial and local level, and networks of support for staff working in child health in remote areas. In the poorer high mortality burden countries of the Pacific, to meet the clinical and public health gaps, there is a need for increases in the education of child health nurse practitioners, and development of systems of continuing professional development for paediatric doctors and nurses. Involvement in local research, especially that which contributes directly to critical issues in child health policy or strengthening national data systems builds capacity for leadership.

  6. Severe Anemia with Hemoperitoneum as a First Presentation for Multinodular Hepatocellular Carcinoma: A Rare Event in Western Countries

    Directory of Open Access Journals (Sweden)

    Thein Swe

    2016-01-01

    Full Text Available Hemoperitoneum due to spontaneous rupture of hepatocellular carcinoma is a life-threatening and rare condition in western countries with an incidence of less than 3% because of early detection of cirrhosis and neoplasm. Here, we describe a case of a 66-year-old male patient with altered mental status with hemorrhagic shock. Computed tomography scan of abdomen revealed hemoperitoneum and mass in liver. Patient underwent resection of liver tumor and biopsy revealed multinodular hepatocellular carcinoma. A high degree of suspicion is required where severe anemia and hemoperitoneum can be a first presentation for hepatocellular carcinoma especially in patients with chronic hepatitis C infection. Early diagnosis is crucial since mortality rates remain high for untreated cases.

  7. The moral code in Islam and organ donation in Western countries: reinterpreting religious scriptures to meet utilitarian medical objectives.

    Science.gov (United States)

    Rady, Mohamed Y; Verheijde, Joseph L

    2014-06-02

    End-of-life organ donation is controversial in Islam. The controversy stems from: (1) scientifically flawed medical criteria of death determination; (2) invasive perimortem procedures for preserving transplantable organs; and (3) incomplete disclosure of information to consenting donors and families. Data from a survey of Muslims residing in Western countries have shown that the interpretation of religious scriptures and advice of faith leaders were major barriers to willingness for organ donation. Transplant advocates have proposed corrective interventions: (1) reinterpreting religious scriptures, (2) reeducating faith leaders, and (3) utilizing media campaigns to overcome religious barriers in Muslim communities. This proposal disregards the intensifying scientific, legal, and ethical controversies in Western societies about the medical criteria of death determination in donors. It would also violate the dignity and inviolability of human life which are pertinent values incorporated in the Islamic moral code. Reinterpreting religious scriptures to serve the utilitarian objectives of a controversial end-of-life practice, perceived to be socially desirable, transgresses the Islamic moral code. It may also have deleterious practical consequences, as donors can suffer harm before death. The negative normative consequences of utilitarian secular moral reasoning reset the Islamic moral code upholding the sanctity and dignity of human life.

  8. [Diagnostic criteria and risk assessment of complications after gastric cancer surgery in western countries].

    Science.gov (United States)

    Wu, Zhouqiao; Wang, Qi; Shi, Jinyao; Cherry, Koh; Desiderio, Jacopo; Li, Ziyu; Ji, Jiafu

    2017-02-25

    Postoperative complications are important outcome measurements for surgical quality and safety control. However, the complication registration has always been problematic due to the lack of definition consensus and the other practical difficulties. This narrative review summarizes the data registry system for single institutional registry, national data registry, international multi-center trial registries in the western world, aiming to share the experience of complication classification and data registration. We interviewed Dr. Koh from Royal Prince Alfred Hospital in Australia for single institutional experience, Dr. van der Wielen and Dr. Desideriofor, from two international multi-center trial(STOMACH) and registry (IMIGASTRIC) respectively, and Prof. Dr. Wijnhoven from the Dutch Upper GI Audit(DUCA). The major questions include which complications are obligated to report in the respective registry, what are the definitions of those complications, who perform the registration, and how are the complications evaluated or classified. Four telephone conferences were initiated to discuss the above-mentioned topics. The DUCA and IMGASTRIC provided the definition of the major complications. The consent definition provided by DUCA was based on the LOW classification which came out after a four-year discussion and consensus meeting among international experts in the according field. However, none of the four registries asked for an obligatory standardization of the diagnostic criteria among the participating centers or surgeons. Instead, all the registries required a detailed recording of the diagnostic strategy and classification of the complications with the Clavien-Dindo scoring system. Most data were registered by surgeons or data managers during or immediately after the hospitalization. The investigators or an independent third party conducted the auditing of the data quality. Standardization of complication diagnosis among different centers is a difficult task

  9. Body image perceptions in Western and post-communist countries: a cross-cultural pilot study of children and parents.

    Science.gov (United States)

    Humenikova, Lenka; Gates, Gail E

    2008-07-01

    The development of an unrealistic ideal body image and body size dissatisfaction among children is common in Western countries, including the USA and many European nations. However, little is known about children's body image perceptions in post-communist countries. This pilot study evaluated body image perceptions in a sample of Czech school-aged children and their parents and compared them with the perceptions of American children and parents. Ninety-seven Czech and 45 American 4th-6th graders and their parents from eight urban schools participated in this study. A previously developed silhouette body image instrument was utilized in a parent questionnaire and during child interviews to measure perceived and ideal body image perceptions of children and parents. Descriptive statistics, independent t-tests and paired t-tests were used to compare differences between children's and parents' perceived and ideal body image perceptions. Associations between body image perceptions and other variables were explored using bivariate correlations. American children had a thinner ideal body image compared with Czech children (P Parent's ideal body image for their children did not differ by nationality (P = 0.858). While the pressure on children to look thinner was apparent among both American and Czech children, Czech children considered a larger body size as more ideal. A future study should evaluate body image perceptions and factors influencing these perceptions in a representative sample of Czech children and parents.

  10. The Media as a Dual Mediator of the Political Agenda–Setting Effect of Protest : A Longitudinal Study in Six Western European Countries

    NARCIS (Netherlands)

    Vliegenthart, R.; Walgrave, S.; Wouters, R.; Hutter, S.; Jennings, W.; Gava, R.; Tresh, A.; Varone, F.; Grossman, E.; Breunig, C.; Brouard, S.; Chaques-Bonafont, L.

    2016-01-01

    The study investigates the impact of media coverage of protest on issue attention in parliament (questions) in six Western European countries. Integrating several data sets on protest, media, and political agendas, we demonstrate that media coverage of protest affects parliamentary agendas: the more

  11. The Big-Fish-Little-Pond Effect: Generalizability of Social Comparison Processes over Two Age Cohorts from Western, Asian, and Middle Eastern Islamic Countries

    Science.gov (United States)

    Marsh, Herbert W.; Abduljabbar, Adel Salah; Morin, Alexandre J. S.; Parker, Philip; Abdelfattah, Faisal; Nagengast, Benjamin; Abu-Hilal, Maher M.

    2015-01-01

    Extensive support for the seemingly paradoxical negative effects of school- and class-average achievement on academic self-concept (ASC)-the big-fish-little-pond effect (BFLPE)--is based largely on secondary students in Western countries or on cross-cultural Program for International Student Assessment studies. There is little research testing the…

  12. A Comparison of Food Supply from 1984 to 2009 and Degree of Dietary Westernization in Taiwan with Asian Countries and World Continents

    Directory of Open Access Journals (Sweden)

    Cheau-Jane Peng

    2015-01-01

    Full Text Available Objective. To compare quality, quantity, and trends of food supply from 1984 to 2009 and degree of food westernization in Taiwan with Asian countries and world continents by using food balance data. Methods. We compiled data from food balance sheets of Taiwan and Food and Agriculture Organization, including five continents and three most populated countries each in Eastern, Southern, and Southeastern Asia over the period 1984–2009. Quantity of food supply per capita was referenced to Taiwan food guides. The population-weighted means of food supply from Europe, North America, South America, and Australia and New Zealand continents in terms of energy and nutrient distributions, animal/plant sources, and sugar/alcohol contribution were used as indicators of westernization. Trends of food supply per capita of six food groups were plotted, and linear regression was applied to evaluate food changes. Findings. Taiwan’s food supply provided sufficient quantity in food energy, with the lowest cereals/roots supply and rice to wheat ratio, but the highest meat and oil supplies per capita among the 10 studied Asian countries. Taiwan food supply showed the most westernization among these countries. Conclusion. Food supply of Taiwan, although currently sufficient, indicated some security problems and high tendency of diet westernization.

  13. A review of abortion laws in Western-European countries. A cross-national comparison of legal developments between 1960 and 2010

    NARCIS (Netherlands)

    Levels, Mark; Sluiter, Roderick; Need, Ariana

    2014-01-01

    The extent to which women have had access to legal abortions has changed dramatically in Western-Europe between 1960 and 2010. In most countries, abortion laws developed from completely banning abortion to allowing its availability on request. Both the timing and the substance of the various legal

  14. A Comparison of Food Supply from 1984 to 2009 and Degree of Dietary Westernization in Taiwan with Asian Countries and World Continents.

    Science.gov (United States)

    Peng, Cheau-Jane; Lin, Cheng-Yao; Guo, How-Ran

    2015-01-01

    To compare quality, quantity, and trends of food supply from 1984 to 2009 and degree of food westernization in Taiwan with Asian countries and world continents by using food balance data. We compiled data from food balance sheets of Taiwan and Food and Agriculture Organization, including five continents and three most populated countries each in Eastern, Southern, and Southeastern Asia over the period 1984-2009. Quantity of food supply per capita was referenced to Taiwan food guides. The population-weighted means of food supply from Europe, North America, South America, and Australia and New Zealand continents in terms of energy and nutrient distributions, animal/plant sources, and sugar/alcohol contribution were used as indicators of westernization. Trends of food supply per capita of six food groups were plotted, and linear regression was applied to evaluate food changes. Taiwan's food supply provided sufficient quantity in food energy, with the lowest cereals/roots supply and rice to wheat ratio, but the highest meat and oil supplies per capita among the 10 studied Asian countries. Taiwan food supply showed the most westernization among these countries. Food supply of Taiwan, although currently sufficient, indicated some security problems and high tendency of diet westernization.

  15. Prevalence and clinical implications of epstein-barr virus infection in de novo diffuse large B-cell lymphoma in Western countries

    DEFF Research Database (Denmark)

    Ok, Chi Young; Li, Ling; Xu-Monette, Zijun Y

    2014-01-01

    PURPOSE: Epstein-Barr virus-positive (EBV(+)) diffuse large B-cell lymphoma (DLBCL) of the elderly is a variant of DLBCL with worse outcome that occurs most often in East-Asian countries and is uncommon in the Western hemisphere. We studied the largest cohort of EBV(+) DLBCL, independent of age...

  16. Trial use of the Personal Qualities Assessment (PQA) in the entrance examination of a Japanese medical university: similarities to the results in western countries.

    Science.gov (United States)

    Fukui, Yuriko; Noda, Saeko; Okada, Midori; Mihara, Nakako; Kawakami, Yoriko; Bore, Miles; Munro, Don; Powis, David

    2014-01-01

    The Personal Qualities Assessment (PQA), developed by the University of Newcastle, Australia to assess the aptitude of future medical professionals, has been used in Western countries. The objective was to investigate whether the PQA is appropriate for Japanese medical school applicants. Two of the PQA tests, Libertarian-Dual-Communitarian moral orientations (Mojac) and Narcissism, Aloofness, Confidence, and Empathy (NACE), were translated into Japanese, and administered at the Tokyo Women's Medical University entrance examinations from 2007 to 2009. The distributions of the applicants' Mojac and NACE scores were close to the normal distribution, and the mean scores did not exhibit a large difference from those in Western countries. The only significant difference was that the mean score of the NACE test was slightly lower than the Western norm. The translated PQA tests may be appropriate for use with Japanese applicants, though further research considering cultural differences is required.

  17. Development of immunohistochemistry services for cancer care in western Kenya: Implications for low- and middle-income countries

    Directory of Open Access Journals (Sweden)

    Kirtika Patel

    2016-05-01

    Objectives, methods and outcomes: Over the past decade, in an academic North-South collaboration, cancer services were developed for the catchment area of Moi Teaching and Referral Hospital in western Kenya. A major hurdle to treatment of cancer in a resource-limited setting has been the lack of adequate diagnostic services. Building upon the foundations of a histology laboratory, strategic investment and training were used to develop IHC services. Key elements of success in this endeavour included: translation of resource-rich practices to are source-limited setting, such as using manual, small-batch IHC instead of disposable- and maintenance-intensive automated machinery, engagement of outside expertise to develop reagent-efficient protocols and supporting all levels of staff to meet the requirements of an external quality assurance programme. Conclusion: Development of low- and middle-income country models of services, such as the IHC laboratory presented in this paper, is critical for the infrastructure in resource-limited settings to address the growing cancer burden. We provide a low-cost model that effectively develops these necessary services in a challenging laboratory environment.

  18. Performance of oil industry cross-country pipelines in Western Europe. Statistical summary of reported spillages: 1978

    Energy Technology Data Exchange (ETDEWEB)

    de Waal, A.; Baradat, Y.

    1979-01-01

    CONCAWE's annual report on oil industry cross-country pipelines in Western Europe shows that in 1978 the pipeline network reached a combined length of 18,500 kilometres and transported 594 million cubic metres of crude oil and refined products. The gross spillage amounted to 3639 m/sup 3/, that is 0.000613 percent or about 6.1 parts per million of the total quantity transported. The net spillage loss was 1,377 m/sup 3/ since 2,262 m/sup 3/ were recovered at site. There were 15 spillage incidents reported during 1978, all of which were directly related to pipelines (none to pump-stations). In 4 incidents the oil spilled was completely recovered, and in 10 cases clean-up was completed within one week of the discovery of the spillage. No contamination of potable water sources was reported. The causes of the spillages are attributed to corrosion (7 incidents), third party activities (4), mechanical failure (3) and natural hazards, i.e. excessive rainfall (1). The report also gives a comparison for the five-year period 1974 to 1978.

  19. Performance of oil industry cross-country pipelines in Western Europe. Statistical summary of reported spillages, 1978

    Energy Technology Data Exchange (ETDEWEB)

    de Waal, A.; Baradat, Y.

    1979-01-01

    CONCAW's annual report on oil industry cross-country pipelines in Western Europe shows that in 1978 the pipeline network reached a combined length of 18,500 kilometers and transported 594 million cubic meters of crude oil and refined products. The gross spillage amounted to 3639 m/sup 3/, that is 0.000613% or about 6.1 ppM of the total quantity transported. The new spillage loss was 1377 m/sup 3/ since 2262 m/sup 3/ were recovered at site. There were 15 spillage incidents reported during 1978, all of which were directly related to pipelines (none to pump-stations). In 4 incidents the oil spilled was completely recovered, and in 10 cases clean-up was completed within one week of the discovery of the spillage. No contamination of potable water sources was reported. The causes of the spillages are attributed to corrosion (7 incidents), third party activities (4), mechanical failure (3) and natural hazards, i.e., excessive rainfall (1). The report also gives a comparison for the five-year period 1974-1978.

  20. Performance of oil industry cross-country pipelines in Western Europe, statistical summary of reported spillages - 1978

    Energy Technology Data Exchange (ETDEWEB)

    de Waal, A.; Baradat, Y.

    CONCAWE's annual report on oil industry cross-country pipelines in Western Europe shows that in 1978 the pipeline network reached a combined length of 18,500 kilometers and transported 594 million cubic meters of crude oil and refined products. The gross spillage amounted to 3639 cu. m, that is 0.000613 per cent or about 6.1 parts per million of the total quantity transported. The net spillage loss was 1,377 cu. m since 2,262 cu. m were recovered at site. There were 15 spillage incidents reported during 1978, all of which were directly related to pipelines (none to pump-stations). In 4 incidents the oil spilled was completely recovered, and in 10 cases clean-up was completed within one week of the discovery of the spillage. No contamination of potable water sources was reported. The causes of the spillages are attributed to corrosion (7 incidents), third party activities (4), mechanical failure (3) and natural hazards, i.e. excessive rainfall (1). The report also gives a comparison for the five-year period 1974-1978. (Copyright (c) CONCAWE 1979.)

  1. Cultural Differences between Chinese and Western Countries in Advertisements%从广告语看中西文化差异

    Institute of Scientific and Technical Information of China (English)

    石成蓉

    2007-01-01

    Cultural difference can be found in many aspects, this paper deals with the differences between Chinese culture and English culture in the perspective of advertisements. Advertising is an important part of people's life. Advertisements in a certain country attract certain consumers, so they reflect the unique culture in the given country. This paper will focus on four aspects to illustrate the cultural difference between China and Western countries found in advertising creation and advertising language aimed to help people understand cultural difference in the trend of globalization and accelerate the cross-cultural communication.

  2. CEMENT SLURRIES FOR GEOTHERMAL WELLS CEMENTING

    Directory of Open Access Journals (Sweden)

    Nediljka Gaurina-Međimurec

    1994-12-01

    Full Text Available During a well cementing special place belongs to the cement slurry design. To ensure the best quality of cementing, a thorough understanding of well parameters is essential, as well as behaviour of cement slurry (especially at high temperatures and application of proven cementing techniques. Many cement jobs fail because of bad job planning. Well cementing without regarding what should be accomplished, can lead to well problems (channels in the cement, unwanted water, gas or fluid production, pipe corrosion and expensive well repairs. Cementing temperature conditions are important because bot-tomhole circulating temperatures affect slurry thickening time, arheology, set time and compressive strength development. Knowing the actual temperature which cement encounters during placement allows the selection of proper cementing materials for a specific application. Slurry design is affected by well depth, bottom hole circulating temperature and static temperature, type or drilling fluid, slurry density, pumping time, quality of mix water, fluid loss control, flow regime, settling and free water, quality of cement, dry or liquid additives, strength development, and quality of the lab cement testing and equipment. Most Portland cements and Class J cement have shown suitable performances in geot-hermal wells. Cement system designs for geothermal wells differ from those for conventional high temperature oil and gas wells in the exclusive use of silica flour instead of silica sand, and the avoidance of fly ash as an extender. In this paper, Portland cement behaviour at high temperatures is described. Cement slurry and set cement properties are also described. Published in literature, the composition of cement slurries which were tested in geothermal conditions and which obtained required compressive strength and water permeability are listed. As a case of our practice geothermal wells Velika Ciglena-1 and Velika Ciglena-la are described.

  3. Intra-organizational dynamics as drivers of entrepreneurship among physicians and managers in hospitals of western countries.

    Science.gov (United States)

    Koelewijn, Wout T; Ehrenhard, Michel L; Groen, Aard J; van Harten, Wim H

    2012-09-01

    During the past decade, entrepreneurship in the healthcare sector has become increasingly important. The aging society, the continuous stream of innovative technologies and the growth of chronic illnesses are jeopardizing the sustainability of healthcare systems. In response, many European governments started to reform healthcare during the 1990s, replacing the traditional logic of medical professionalism with business-like logics. This trend is expected to continue as many governments will have to reduce their healthcare spending in response to the current growing budget deficits. In the process, entrepreneurship is being stimulated, yet little is known about intra-hospital dynamics leading to entrepreneurial behavior. The purpose of this article is to review existing literature concerning the influence of intra-organizational dynamics on entrepreneurship among physicians and managers in hospitals of Western countries. Therefore, we conducted a theory-led, systematic review of how intra-organizational dynamics among hospital managers and physicians can influence entrepreneurship. We designed our review using the neo-institutional framework of Greenwood and Hinings (1996). We analyze these dynamics in terms of power dependencies, interest dissatisfaction and value commitments. Our search revealed that physicians' dependence on hospital management has increased along with healthcare reforms and the resulting emphasis on business logics. This has induced various types of responses by physicians. Physicians can be pushed to adopt an entrepreneurial attitude as part of a defensive value commitment toward the business-like healthcare logic, to defend their traditionally dominant position and professional autonomy. In contrast, physicians holding a transformative attitude toward traditional medical professionalism seem more prone to adopt the entrepreneurial elements of business-like healthcare, encouraged by the prospect of increased autonomy and income. Interest

  4. Lunar cement

    Science.gov (United States)

    Agosto, William N.

    1992-01-01

    With the exception of water, the major oxide constituents of terrestrial cements are present at all nine lunar sites from which samples have been returned. However, with the exception of relatively rare cristobalite, the lunar oxides are not present as individual phases but are combined in silicates and in mixed oxides. Lime (CaO) is most abundant on the Moon in the plagioclase (CaAl2Si2O8) of highland anorthosites. It may be possible to enrich the lime content of anorthite to levels like those of Portland cement by pyrolyzing it with lunar-derived phosphate. The phosphate consumed in such a reaction can be regenerated by reacting the phosphorus product with lunar augite pyroxenes at elevated temperatures. Other possible sources of lunar phosphate and other oxides are discussed.

  5. Cement replacement materials. Properties, durability, sustainability

    International Nuclear Information System (INIS)

    Ramezanianpour, Ali Akbar

    2014-01-01

    The aim of this book is to present the latest findings in the properties and application of Supplementary Cementing Materials and blended cements currently used in the world in concrete. Sustainability is an important issue all over the world. Carbon dioxide emission has been a serious problem in the world due to the greenhouse effect. Today many countries agreed to reduce the emission of CO2. Many phases of cement and concrete technology can affect sustainability. Cement and concrete industry is responsible for the production of 7% carbon dioxide of the total world CO2 emission. The use of supplementary cementing materials (SCM), design of concrete mixtures with optimum content of cement and enhancement of concrete durability are the main issues towards sustainability in concrete industry.

  6. The in vitro evaluation of tigecycline tested against pathogens isolated in eight countries in the Asia-Western Pacific region (2008).

    Science.gov (United States)

    Farrell, David J; Turnidge, John D; Bell, Jan; Sader, Helio S; Jones, Ronald N

    2010-06-01

    To determine the in vitro activity of tigecycline and comparator common use antimicrobial agents tested against contemporary bacterial pathogens from the Asia-Western Pacific region. As part of the SENTRY Antimicrobial Surveillance Program, a total of 5759 Gram-positive and Gram-negative isolates were collected from 28 medical centers in eight Asia-Western Pacific countries during 2008. Minimum inhibitory concentrations (MICs) were determined using Clinical and Laboratory Standards Institute (CLSI) broth microdilution method and interpreted using CLSI breakpoints. United States Food and Drug Administration (US-FDA) breakpoints were used to interpret tigecycline susceptibility. Antimicrobial resistance was found to be widespread and prevalence varied considerably between the eight countries. Against pathogens for which breakpoints were available, >98% of all isolates were susceptible to tigecycline. Against all Gram-positive isolates, including methicillin (oxacillin)-resistant Staphylococcus aureus, penicillin- and multidrug-resistant pneumococci, and vancomycin-resistant enterococci, the highest tigecycline MIC found was 1 microg/ml. Against all Enterobacteriaceae, including extended-spectrum beta-lactamase phenotypes, tigecycline susceptibility was 97.5%. Tigecycline had good activity against Acinetobacter spp. but was much less active against Pseudomonas aeruginosa. Tigecycline demonstrated excellent sustained in vitro activity against a wide spectrum of contemporary Gram-positive and -negative pathogens from Asia-Western Pacific countries. Copyright (c) 2010 The British Infection Society. Published by Elsevier Ltd. All rights reserved.

  7. Socioeconomic development as a determinant of the levels of organochlorine pesticides and PCBs in the inhabitants of Western and Central African countries

    International Nuclear Information System (INIS)

    Luzardo, Octavio P.; Boada, Luis D.; Carranza, Cristina; Ruiz-Suárez, Norberto; Henríquez-Hernández, Luis Alberto; Valerón, Pilar F.; Zumbado, Manuel; Camacho, María; Arellano, José Luis Pérez

    2014-01-01

    Several studies of environmental samples indicate that the levels of many persistent organic pollutants (POPs) are increasing in Africa, but few studies have been conducted in humans. Simultaneously, many African countries are experiencing a rapid economic growth and implementing information and communication technologies (ICT). These changes have generated high amounts of electronic waste (e-waste) that have not been adequately managed. We tested the hypothesis that the current levels of two main classes of POPs in Western and Central African countries are affected by the degree of socioeconomic development. We measured the levels of 36 POPs in the serum of recent immigrants (N = 575) who came from 19 Sub-Saharan countries to the Canary Islands (Spain). We performed statistical analyses on their anthropometric and socioeconomic data. High median levels of POPs were found in the overall sample, with differences among the countries. Organochlorine pesticide (OCP) and polychlorinated biphenyl (PCB) levels increased with age. People from low-income countries had significantly higher OCP levels and much lower PCB levels than those from high-income countries. We found a significant association between the implementation of ICT and PCB contamination. Immigrants from the countries with a high volume of imports of second-hand electronic equipment had higher PCB levels. The economic development of Africa and the e-waste generation have directly affected the levels of POPs. The POP legacies of these African populations most likely are due to the inappropriate management of the POPs' residues. - Highlights: • Higher levels of organochlorine pesticides in Africans from low-income countries • Higher levels of PCBs in Africans from high-income countries • Levels of PCBs are significantly higher in people from West Africa. • Significant association between implementation of ICT and PCB contamination • High volume of second-hand electronic equipment is associated

  8. Socioeconomic development as a determinant of the levels of organochlorine pesticides and PCBs in the inhabitants of Western and Central African countries

    Energy Technology Data Exchange (ETDEWEB)

    Luzardo, Octavio P., E-mail: operez@dcc.ulpgc.es [Toxicology Unit, Department of Clinical Sciences, Universidad de Las Palmas de Gran Canaria, Las Palmas de Gran Canaria (Spain); Boada, Luis D. [Toxicology Unit, Department of Clinical Sciences, Universidad de Las Palmas de Gran Canaria, Las Palmas de Gran Canaria (Spain); Carranza, Cristina [Infectious Diseases and Tropical Medicine Unit, Hospital Universitario Insular de Gran Canaria, Las Palmas de Gran Canaria (Spain); Medical Sciences and Surgery Department, Universidad de Las Palmas de Gran Canaria, Las Palmas de Gran Canaria (Spain); Ruiz-Suárez, Norberto; Henríquez-Hernández, Luis Alberto; Valerón, Pilar F.; Zumbado, Manuel; Camacho, María [Toxicology Unit, Department of Clinical Sciences, Universidad de Las Palmas de Gran Canaria, Las Palmas de Gran Canaria (Spain); Arellano, José Luis Pérez [Infectious Diseases and Tropical Medicine Unit, Hospital Universitario Insular de Gran Canaria, Las Palmas de Gran Canaria (Spain); Medical Sciences and Surgery Department, Universidad de Las Palmas de Gran Canaria, Las Palmas de Gran Canaria (Spain)

    2014-11-01

    Several studies of environmental samples indicate that the levels of many persistent organic pollutants (POPs) are increasing in Africa, but few studies have been conducted in humans. Simultaneously, many African countries are experiencing a rapid economic growth and implementing information and communication technologies (ICT). These changes have generated high amounts of electronic waste (e-waste) that have not been adequately managed. We tested the hypothesis that the current levels of two main classes of POPs in Western and Central African countries are affected by the degree of socioeconomic development. We measured the levels of 36 POPs in the serum of recent immigrants (N = 575) who came from 19 Sub-Saharan countries to the Canary Islands (Spain). We performed statistical analyses on their anthropometric and socioeconomic data. High median levels of POPs were found in the overall sample, with differences among the countries. Organochlorine pesticide (OCP) and polychlorinated biphenyl (PCB) levels increased with age. People from low-income countries had significantly higher OCP levels and much lower PCB levels than those from high-income countries. We found a significant association between the implementation of ICT and PCB contamination. Immigrants from the countries with a high volume of imports of second-hand electronic equipment had higher PCB levels. The economic development of Africa and the e-waste generation have directly affected the levels of POPs. The POP legacies of these African populations most likely are due to the inappropriate management of the POPs' residues. - Highlights: • Higher levels of organochlorine pesticides in Africans from low-income countries • Higher levels of PCBs in Africans from high-income countries • Levels of PCBs are significantly higher in people from West Africa. • Significant association between implementation of ICT and PCB contamination • High volume of second-hand electronic equipment is associated

  9. Institutional shifts in inter-municipal service delivery: an analysis of developments in eight Western European countries

    NARCIS (Netherlands)

    Hulst, J.R.; van Montfort, A.J.G.M.; Haveri, A.; Airaksinen, J.; Kelly, J.

    2009-01-01

    Comparative research on inter-municipal cooperation in eight European countries shows that there is a great variety of institutional arrangements for cooperation across the different countries. Also, these arrangements tend to change over time in terms of the scope of cooperation among partners,

  10. THE FLAT TAX EFFECTS a€“ THEORETICAL AND EMPIRICAL EVIDENCE IN WESTERN AND EASTERN EUROPEAN COUNTRIES

    Directory of Open Access Journals (Sweden)

    Moga Aura Carmen

    2009-05-01

    Full Text Available This paper takes a close look at the advantages and disadvantages of the flat tax and looks at its proven benefits and failings in some European countries which adopted it and its theoretical or possible effects on the economies of other European countrie

  11. North Korea's Trade Expansion with Western Countries in the Early 1970's and Its Implications on North Korea's Current Attempts at Economic Rehabilitation

    Directory of Open Access Journals (Sweden)

    Jong-Woon Lee

    2002-12-01

    Full Text Available The purpose of this study is to provide the analytical background of North Korea's trade expansion with Western countries in the early 1970's and examine in depth the resulting impacts on the North Korean economy. Indeed, this study explores the implications of the mechanism and consequences of North Korea's increased trade with Western countries in the 1970's for the current situation of the country's trade expansion based on the rapid increase in imports and large trade deficit. As a result of researching North Korea's economic trajectory during the 1970's within this focus, this study asserts that, despite some positive aspects, North Korea's rapid increase of foreign trade in recent years possesses the immanent possibility of generating serious obstacles to the process of economic recovery. In this vein, this paper intends to explore some policy options North Korea should choose in order to create conditions conducive to economic rehabilitation and prevent the recurrence of similar situation as experienced in the 1970's.

  12. Performance of oil industry cross-country pipelines in Western Europe: statistical summary of reported spillages, 1979

    Energy Technology Data Exchange (ETDEWEB)

    de Waal, A.; Hayward, P.; Panisi, C.; Groenhof, J.

    This report presents statistical data relating to spillages from oil industry cross-country pipelines during the calendar year 1979, with comments and comparisons for the five year period 1975-1979. (Copyright (c) CONCAWE 1980.)

  13. Quality of life after ischemic stroke varies in western countries: data from the tinzaparin in Acute Ischaemic Stroke Trial (TAIST).

    Science.gov (United States)

    Sprigg, Nikola; Gray, Laura J; Bath, Philip M W; Christensen, Hanne; De Deyn, Peter Paul; Leys, Didier; O'Neill, Desmond; Ringelstein, E Bernd

    2012-10-01

    Functional outcome after stroke varies significantly between countries. However, whether health-related quality of life (QoL) after stroke also differs between countries is unknown. TAIST was a randomised controlled trial assessing the safety and efficacy of tinzaparin versus aspirin in 1484 patients with acute ischaemic stroke across 11 countries. Countries were grouped into 5 geographic regions: British Isles (Ireland and UK), Franco (Belgium and France), North America (Canada), northwest Europe (Germany and The Netherlands), and Scandinavia (Denmark, Finland, Norway, and Sweden). QoL was measured at 6 months using the Short-Form 36 (SF-36) health survey. The relationship between region and QoL was assessed relative to the British Isles using linear regression adjusted for case mix, service quality variables, and treatment assignment. A total of 1220 survivors were included in this analysis. Significant differences in QoL were identified between countries and regions; northwest Europe rated their QoL highest in terms of physical functioning (20.3; 95% confidence interval [CI] 10.8-29.8), bodily pain (12.3; 95% CI, 2.7-22.0), and vitality (9.0; 95% CI, 1.1-16.9). Franco countries reported the lowest QoL for emotional role (-17.9; 95% CI, -32.6 to -3.3) and mental health (-11.2; 95% CI, -18.2 to -4.3). The British Isles rated QoL lowest for physical and social functioning. Our data indicate that QoL varies considerably among countries and regions, even when adjusted for prognostic case mix and care quality variables. How different case mixes and healthcare systems might contribute to these findings merits further investigation. Copyright © 2012 National Stroke Association. Published by Elsevier Inc. All rights reserved.

  14. Socioeconomic development as a determinant of the levels of organochlorine pesticides and PCBs in the inhabitants of Western and Central African countries.

    Science.gov (United States)

    Luzardo, Octavio P; Boada, Luis D; Carranza, Cristina; Ruiz-Suárez, Norberto; Henríquez-Hernández, Luis Alberto; Valerón, Pilar F; Zumbado, Manuel; Camacho, María; Arellano, José Luis Pérez

    2014-11-01

    Several studies of environmental samples indicate that the levels of many persistent organic pollutants (POPs) are increasing in Africa, but few studies have been conducted in humans. Simultaneously, many African countries are experiencing a rapid economic growth and implementing information and communication technologies (ICT). These changes have generated high amounts of electronic waste (e-waste) that have not been adequately managed. We tested the hypothesis that the current levels of two main classes of POPs in Western and Central African countries are affected by the degree of socioeconomic development. We measured the levels of 36 POPs in the serum of recent immigrants (N=575) who came from 19 Sub-Saharan countries to the Canary Islands (Spain). We performed statistical analyses on their anthropometric and socioeconomic data. High median levels of POPs were found in the overall sample, with differences among the countries. Organochlorine pesticide (OCP) and polychlorinated biphenyl (PCB) levels increased with age. People from low-income countries had significantly higher OCP levels and much lower PCB levels than those from high-income countries. We found a significant association between the implementation of ICT and PCB contamination. Immigrants from the countries with a high volume of imports of second-hand electronic equipment had higher PCB levels. The economic development of Africa and the e-waste generation have directly affected the levels of POPs. The POP legacies of these African populations most likely are due to the inappropriate management of the POPs' residues. Copyright © 2014 Elsevier B.V. All rights reserved.

  15. Producing cement

    Energy Technology Data Exchange (ETDEWEB)

    Stone, E G

    1923-09-12

    A process and apparatus are described for producing Portland cement in which pulverized shale is successively heated in a series of inclined rotary retorts having internal stirrers and oil gas outlets, which are connected to condensers. The partially treated shale is removed from the lowermost retort by a conveyor, then fed separately or conjointly into pipes and thence into a number of vertically disposed retorts. Each of these retorts may be fitted interiorly with vertical arranged conveyors which elevate the shale and discharge it over a lip, from whence it falls to the bottom of the retorts. The lower end of each casing is furnished with an adjustable discharge door through which the spent shale is fed to a hopper, thence into separate trucks. The oil gases generated in the retorts are exhausted through pipes to condensers. The spent shale is conveyed to a bin and mixed while hot with ground limestone. The admixed materials are then ground and fed to a rotary kiln which is fired by the incondensible gases derived from the oil gases obtained in the previous retorting of the shale. The calcined materials are then delivered from the rotary kiln to rotary coolers. The waste gases from the kiln are utilized for heating the retorts in which the ground shale is heated for the purpose of extracting therefrom the contained hydrocarbon oils and gases.

  16. Building multi-country collaboration on watershed management: lessons on linking environment and public health from the Western Balkans

    Science.gov (United States)

    Community-based watershed resilience programs that bridge public health and environmental outcomes often require cross-boundary, multi-country collaboration. The CRESSIDA project, led by the Regional Environmental Center for Central and Eastern Europe (REC) and supported by the U...

  17. The Making of the Executive Head: The Process of Defining Institutional Leaders in Certain Western European Countries.

    Science.gov (United States)

    Neave, Guy

    1988-01-01

    An examination of the formal procedures by which European university's chief executive is selected and the role he or she fulfills finds many differences among countries. One notable innovation is the election of administrators within the institution. It is suggested that the drive toward professional management may endanger academic collegiality.…

  18. English in Product Advertisements in Non-English-Speaking Countries in Western Europe: Product Image and Comprehension of the Text

    NARCIS (Netherlands)

    Gerritsen, M.; Nickerson, C.; Hooft, A.P.J.V. van; Meurs, W.F.J. van; Korzilius, H.P.L.M.; Nederstigt, U.; Starren, M.B.P.; Crijns, R.M.J.

    2010-01-01

    Although English has been shown to be the most frequently used foreign language in product advertisements in countries where it is not the native language, little is known about its effects. This article examines the response to advertisements in English compared to the response to the same ad in

  19. Lining up higher education. Trends in selected higher education statistics in ten Western countries (IHEM Trendreport 2004)

    NARCIS (Netherlands)

    Kaiser, Franciscus; Hillegers, Harm; Legro, Iwen

    2005-01-01

    In this fourth IHEM trend report, key statistical issues like student flows (new entrants, enrolment, and graduation, broken down by discipline and gender), rates of participation, staff, and finance are presented for the ten IHEM core countries over the period 1995 till recent. National statistical

  20. WHITE CEMENT IN SUSTAINABLE DEVELOPMENT

    OpenAIRE

    Y.C.P RAMANA BABU; B.SAI DOONDI; N. M .V .VAMSI KRISHNA; K.PRASANTHI

    2013-01-01

    India is one among the fast developing countries in the world in the areas of Infrastructure. Now a day, Carbon monoxide (CO) and carbon dioxide (CO2) are the temporary atmospheric pollutants in the environment chiefly emitted from the fuel burning vehicles and street lights which lead to global warming and pose a major threat tothe survival and sustainable development. This paper deals with the principal purpose of use of white cement in pavement design which will take care of the Green hous...

  1. Cross-cultural medical education: can patient-centered cultural competency training be effective in non-Western countries?

    Science.gov (United States)

    Ho, Ming-Jung; Yao, Grace; Lee, Keng-Lin; Beach, Mary Catherine; Green, Alexander R

    2008-01-01

    No evidence addresses the effectiveness of patient-centered cultural competence training in non-Western settings. To examine whether a patient-centered cultural competency curriculum improves medical students' skills in eliciting the patients' perspective and exploring illness-related social factors. Fifty-seven medical students in Taiwan were randomly assigned to either the control (n = 27) or one of two intervention groups: basic (n = 15) and extensive (n = 15). Both intervention groups received two 2-hour patient-centered cultural competency workshops. In addition, the extensive intervention group received a 2-hour practice session. The control group received no training. At the end of the clerkship, all students were evaluated with an objective structured clinical examination (OSCE). Students in the extensive intervention group scored significantly higher than the basic intervention and control groups in eliciting the patient's perspective (F = 18.38, p social factors (F = 6.66, p = 0.003, eta(2) = 0.20). Patient-centered cultural competency training can produce improvement in medical students' cross-cultural communication skills in non-Western settings, especially when adequate practice is provided.

  2. Asphalt cement poisoning

    Science.gov (United States)

    ... petroleum material that hardens when it cools. Asphalt cement poisoning occurs when someone swallows asphalt. If hot ... found in: Road paving materials Roofing materials Tile cements Asphalt may also be used for other purposes.

  3. Radioactivity of bone cement

    International Nuclear Information System (INIS)

    Scherer, M.A.; Winkler, R.; Ascherl, R.; Lenz, E.

    1993-01-01

    A total of 14 samples of different types of bone cement from five different manufacturers were examined for their radioactivity. Each of the investigated bone cements showed a low radioactivity level, i.e. between [de

  4. Ultrafine portland cement performance

    Directory of Open Access Journals (Sweden)

    C. Argiz

    2018-04-01

    Full Text Available By mixing several binder materials and additions with different degrees of fineness, the packing density of the final product may be improved. In this work, ultrafine cement and silica fume mixes were studied to optimize the properties of cement-based materials. This research was performed in mortars made of two types of cement (ultrafine Portland cement and common Portland cement and two types of silica fume with different particle-size distributions. Two Portland cement replacement ratios of 4% and 10% of silica fume were selected and added by means of a mechanical blending method. The results revealed that the effect of the finer silica fume mixed with the coarse cement enhances the mechanical properties and pore structure refinement at a later age. This improvement is somewhat lower in the case of ultrafine cement with silica fume.

  5. Sulfur polymer cement concrete

    International Nuclear Information System (INIS)

    Weber, H.H.; McBee, W.C.

    1990-01-01

    Sulfur-based composite materials formulated using sulfur polymer cement (SPC) and mineral aggregates are described and compared with conventional portland cement based materials. Materials characteristics presented include mechanical strength, chemical resistance, impact resistance, moisture permeation, and linear shrinkage during placement and curing. Examples of preparation and placement of sulfur polymer cement concrete (SC) are described using commercial scale equipment. SC applications presented are focused into hostile chemical environments where severe portland cement concrete (PCC) failure has occurred

  6. Using reference nutrient density goals with food balance sheet data to identify likely micronutrient deficits for fortification planning in countries in the Western Pacific region.

    Science.gov (United States)

    Gibson, Rosalind S; Cavalli-Sforza, Tommaso

    2012-09-01

    Collection of nationwide food consumption data at the individual level is the preferred option for planning fortification programs. However, such data are seldom collected in low-income countries. In contrast, Food Balance Sheets (FBS), published annually for approximately 180 countries, may provide a source of national data for program planning. To explore the use of micronutrient densities from FBS data to identify likely deficits for eight micronutrients in national diets. Micronutrient densities in the daily available food supply per capita were calculated from the micronutrient contents of 95 food commodities in 17 Western Pacific Region countries. Densities were compared with reference nutrient density goals developed to ensure that at least 95% of individuals, irrespective of life-stage group, are likely to have adequate intakes. Of the eight micronutrients, Cambodia and Korea D.P.R. had likely deficits for six; China, Fiji, Kiribati, Korea Republic, Lao P.D.R., Philippines, Solomon Islands, Vanuatu, and Viet Nam had likely deficits for five; Brunei Darussalam, Malaysia, Mongolia, New Zealand, and Papua New Guinea had likely deficits for four; and New Caledonia had likely deficits for three. The most frequent deficits were for iron, zinc, and calcium (all countries), followed by vitamin B2 and vitamin A (n = 13), vitamin B1 (n = 2), and vitamin B12 (n = 1). The nutrient density approach could be applied to FBS data for ranking countries according to likely micronutrient deficits, but it provides no information on distribution of nutrient supply for fortification program planning. The approach described here could be applied to data from Household Consumption and Expenditures Surveys (HCES) to characterize households at greatest risk.

  7. Neurological deaths of American adults (55-74) and the over 75's by sex compared with 20 Western countries 1989-2010: Cause for concern.

    Science.gov (United States)

    Pritchard, Colin; Rosenorn-Lanng, Emily

    2015-01-01

    Have USA total neurological deaths (TNDs) of adults (55-74) and the over 75's risen more than in twenty Western Countries? World Health Organization TND data are compared with control mortalities cancer mortality rates (CMRs) and circulatory disease deaths (CDDs) between 1989-1991 and 2008-2010 and odds ratios (ORs) and confidence intervals calculated. Neurological Deaths - Twenty country (TC) average 55-74 male rates per million (pm) rose 2% to 503 pm, USA increased by 82% to 627 pm. TC average females rose 1% to 390 pm, USA rising 48% to 560 pm. TC average over 75's male and female increased 117% and 143%; USA rising 368% and 663%, significantly more than 16 countries. Cancer mortality - Average 55-74 male and female fell 20% and 12%, USA down 36% and 18%. TC average over 75's male and female fell 13% and 15%, the USA 29% and 2%. Circulatory deaths - TC average 55-74 rates fell 60% and 46% the USA down 54% and 53%. Over 75's average down 46% and 39%, USA falling 40% and 33%. ORs for rose substantially in every country. TC average 75's ORs for CMR: TND male and females were 1:2.83 and 1:3.04 but the USA 1:5.18 and 1:6.50. The ORs for CDD: TND male and females TC average was 1:3.42 and 1:3.62 but the USA 1:6.13 and 1:9.89. Every country's neurological deaths rose relative to the controls, especially in the USA, which is a cause for concern and suggests possible environmental influences.

  8. Trends in admissions for acute respiratory infections in children: an inter-country comparison between Western Australia and England

    Directory of Open Access Journals (Sweden)

    Hannah Moore

    2017-04-01

    The availability of similar datasets in two economically similar countries in different hemispheres has afforded the opportunity to characterise and compare the epidemiology of paediatric respiratory infections over a 13 year period. Future analyses will allow us to assess differences in coding practices, seasonality and risk factors such as socio-economic deprivation and prematurity. Furthermore the availability of linked laboratory data for respiratory pathogens in each jurisdiction will allow for comparisons of pathogen-specific epidemiology and the impact of universal vaccination programs.

  9. ULTRA-LIGHTWEIGHT CEMENT

    International Nuclear Information System (INIS)

    Fred Sabins

    2001-01-01

    The objective of this project is to develop an improved ultra-lightweight cement using ultralight hollow glass spheres (ULHS). Work reported herein addresses Task 1: Assess Ultra-Lightweight Cementing Problems and Task 3: Test Ultra-Lightweight Cements. Results reported this quarter include a review and summary of Halliburton Energy Services (HES) and BJ Services historical performance data for lightweight cement applications. These data are analyzed and compared to ULHS cement and foamed cement performances. Similar data is expected from Schlumberger, and an analysis of this data will be completed in the following phases of the project. Quality control testing of materials used to formulate ULHS cements in the laboratory was completed to establish baseline material performance standards. A testing protocol was developed employing standard procedures as well as procedures tailored to evaluate ULHS and foamed cement. This protocol is presented and discussed. Results of further testing of ULHS cements are presented along with an analysis to establish cement performance design criteria to be used during the remainder of the project. Finally, a list of relevant literature on lightweight cement performance is compiled for review during the next quarter

  10. ULTRA-LIGHTWEIGHT CEMENT

    International Nuclear Information System (INIS)

    Fred Sabins

    2001-01-01

    The objective of this project is to develop an improved ultra-lightweight cement using ultra-lightweight hollow glass spheres (ULHS). Work reported herein addresses Task 1: Assess Ultra-Lightweight Cementing Issues, Task 2: Review Russian Ultra-Lightweight Cement Literature, Task 3: Test Ultra-Lightweight Cements, and Task 8: Develop Field ULHS Cement Blending and Mixing Techniques. Results reported this quarter include: preliminary findings from a literature review focusing on problems associated with ultra-lightweight cements; summary of pertinent information from Russian ultra-lightweight cement literature review; laboratory tests comparing ULHS slurries to foamed slurries and sodium silicate slurries for two different applications; and initial laboratory studies with ULHS in preparation for a field job

  11. Implementing preventive iron-folic acid supplementation among women of reproductive age in some Western Pacific countries: possibilities and challenges.

    Science.gov (United States)

    Smitasiri, Suttilak; Solon, Florentino S

    2005-12-01

    Lack of effective implementation mechanisms is identified as a major obstacle in the prevention and control of iron-deficiency anemia. This paper discusses experiences gained from implementing iron-folic acid supplementation in the Philippines, Vietnam, and Cambodia. The understanding of contextual elements is proposed as a foundation for planning interventions. Moreover, it is suggested that a social marketing framework should provide a way of thinking about how to influence related behaviors. The application of a social marketing framework applied using a "5 P's" approach: public relations and collaboration, product, price, place, and promotion, is described, as well as enabling factors (possibilities) and inhibiting factors (challenges) of this approach. Although a program to improve iron nutrition among women of reproductive age may not be simple to implement, it is essential to enhancing health, human development, and economic advancement in developing countries.

  12. Self-management Following a Cardiac Event in People of Chinese Ethnicity Living in Western Countries: A Scoping Review.

    Science.gov (United States)

    Zhang, Ling; Gallagher, Robyn; Ding, Ding; Neubeck, Lis

    2018-06-01

    Health outcomes and impact of cardiovascular disease vary between populations, where ethnic minorities and immigrant groups are more likely to be disadvantaged. Compared with the majority residents, health outcomes, especially short-term mortality from coronary heart disease event are worse in people of Chinese ethnicity, potentially due to poor self-management and experiences with the healthcare system in host countries. A scoping review was conducted. Four overarching themes were found: (1) understanding of heart disease, risk factors and symptom recognition, (2) adherence to medication and lifestyle modification, (3) health service/information choice, and (4) family role in disease self-management and decision making. All themes were greatly influenced by English language proficiency and cultural practices. English language proficiency and cultural practices should be taken into consideration when providing healthcare services for people of Chinese ethnicity, as it plays an important role in self-management and experiences with the healthcare system.

  13. Positive postpartum depression screening practices and subsequent mental health treatment for low-income women in Western countries: a systematic literature review.

    Science.gov (United States)

    Hansotte, Elinor; Payne, Shirley I; Babich, Suzanne M

    2017-01-01

    Left undiagnosed and/or untreated, the short-and long-term sequelae of postpartum depression may negatively impact both mother and child. In Western countries, access to mental health care is influenced by socioeconomic factors. The objective of this systematic literature review is to compile factors that hinder and improve access to postpartum depression treatment in low-income women after a positive screen for postpartum depression. The key question of focus is: what are the characteristics associated with access to mental health treatment for low-income women with a positive postpartum depression screen in Western countries? A PRISMA-based systematic literature review was conducted of studies published in English before February 2016 that looked at treatment for postpartum depression in low-income women who had been identified with the condition. PubMed and EBSCO databases were searched using MESH and key terms and found 100 articles that met the selection criteria. After review by two independent researchers, 18 studies with 17 unique populations were included in the literature review. Two independent abstractors searched the included articles for themes surrounding impediments and advantages for low-income women identified with postpartum depression in obtaining mental health treatment. Characteristics of successful mental health treatment included studies that employed the use of a home visitor and those that separated outcomes for women with previous mental health treatment. Themes that emerged as treatment obstacles included cultural barriers, physical barriers, systemic health care barriers, and social barriers. This review will help to better inform screening and treatment priorities for those in the medical field who may encounter women experiencing postpartum depression and are not aware of the various barriers to care specific to low-income women. This review will also help policymakers identify specific obstacles that are not addressed in postpartum

  14. Ventilatory Function and Cigarette Smoking in Cement Handlers in ...

    African Journals Online (AJOL)

    Introduction: Occupational exposure to dust and cigarette smoking play important roles in the pathogenesis of lung diseases, particularly in developing countries. To determine the effects of outdoor cement dust exposure and cigarette smoking on lung health, we compared ventilatory function in cement handlers (smokers ...

  15. Trends and patterns of antidepressant use in children and adolescents from five western countries, 2005-2012

    DEFF Research Database (Denmark)

    Bachmann, Christian J; Aagaard, Lise; Burcu, Mehmet

    2016-01-01

    and stratified by age, sex, and according to subclass and specific drug. Across the years, the prevalence of ATD use increased from 1.3% to 1.6% in the US data (+26.1%); 0.7% to 1.1% in the UK data (+54.4%); 0.6% to 1.0% in Denmark data (+60.5%); 0.5% to 0.6% in the Netherlands data (+17.6%); and 0.3% to 0.......5% in Germany data (+49.2%). The relative growth was greatest for 15-19 year olds in Denmark, Germany and UK cohorts, and for 10-14 year olds in Netherlands and US cohorts. While SSRIs were the most commonly used ATDs, particularly in Denmark (81.8% of all ATDs), Germany and the UK still displayed notable......Following the FDA black box warning in 2004, substantial reductions in antidepressant (ATD) use were observed within 2 years in children and adolescents in several countries. However, whether these reductions were sustained is not known. The objective of this study was to assess more recent trends...

  16. Simulating Spatial Growth Patterns in Developing Countries: A Case of Shama in the Western Region of Ghana.

    Science.gov (United States)

    Inkoom, J. N.; Nyarko, B. K.

    2014-12-01

    The integration of geographic information systems (GIS) and agent-based modelling (ABM) can be an efficient tool to improve spatial planning practices. This paper utilizes GIS and ABM approaches to simulate spatial growth patterns of settlement structures in Shama. A preliminary household survey on residential location decision-making choice served as the behavioural rule for household agents in the model. Physical environment properties of the model were extracted from a 2005 image implemented in NetLogo. The resulting growth pattern model was compared with empirical growth patterns to ascertain the model's accuracy. The paper establishes that the development of unplanned structures and its evolving structural pattern are a function of land price, proximity to economic centres, household economic status and location decision-making patterns. The application of the proposed model underlines its potential for integration into urban planning policies and practices, and for understanding residential decision-making processes in emerging cities in developing countries. Key Words: GIS; Agent-based modelling; Growth patterns; NetLogo; Location decision making; Computational Intelligence.

  17. Prolactinoma and hyperprolactinaemia: a transcultural comparative study between Germany as a western, liberal, industrialised country and Syria as an oriental society with a strong Islamic tradition.

    Science.gov (United States)

    Kann, Peter Herbert; Juratli, Nour; Kabalan, Younes

    2010-10-01

    Prolactinomas and hyperprolactinaemia cause hypogonadism and impairment of sexual and reproductive function. In this transcultural study, clinical characteristics of prolactinoma/hyperprolactinaemia were compared between a liberal, western, industrialised country and a more traditional, Islamic, oriental society. Sixty-two Syrian patients with hyperprolactinaemia were compared to 62 German patients with hyperprolactinaemia. In Syria and Germany, prolactinoma and hyperprolactinaemia were more frequent in females than in males (Syria 87% females; Germany 63% females). Prolactinomas were larger in males, males were older at diagnosis in both countries. Recorded clinical symptoms were comparable, even if culturally determined differences in spontaneous reporting of and asking for symptoms might be considered. The average age of the Syrian patients at diagnosis of hyperprolactinaemia was more than 6 years lower than in the German cohort (33.4 ± 10.4 vs. 39.7 ± 17.6 years). In Germany, a variety of therapeutic regimens were applied. In Syria, bromocriptine was prescribed exclusively. The differences may be attributed to culturally determined differences in sexual and reproductive behaviour, i.e. sexual intercourses of young, unmarried girls and women in association to the use of oral contraceptives regulating the menstrual cycle, maternal age at first delivery and birth frequency. Exclusive prescription of bromocriptine in Syria may be associated to limited resources and the safety of bromocriptine during pregnancy.

  18. Innovation process in industrialized countries of Western Europe. Vol. 3. Innovations in the power industry. Der Innovationsprozess in westeuropaeischen Industrielaendern. Bd. 3. Innovation in der Energiewirtschaft

    Energy Technology Data Exchange (ETDEWEB)

    Ray, G F [National Institute of Economic and Social Research, London (UK)

    1979-01-01

    A group of European economic research institutes as well as a group of sociologists working in the Social Sciences Department of the University of Hamburg examined the industrial innovation process in companies situated in the Federal Republic of Germany, Great Britain, and Sweden. The following institutes were members of the group of economic research institutes: The Ifo-Institute for Economic Research at Munich, which also assumed coordinating responsibilities, the National Institute of Economic and Social Research, London, as well as the Industriens Utredningsinstitut, Stockholm. The purpose of this multinational project was to examine the process of research work in development and application of technologies using cases of innovation found in the energy industry. The study was intended to lead innovation research out of its methodical and scientific isolation to bridge certain gaps found in the existing innovation research work and thus to provide politicians and innovators in the major industrialized countries of the Western World with useful tools for decision making. Volume 3 contains the general development of the world energy situation and of problems of energy policy to be found in the three countries. Furthermore, it contains detailed studies of the innovation process of the latest major individual technologies to be found in this field.

  19. Coronary heart disease incidence among non-Western immigrants compared to Danish-born people: effect of country of birth, migrant status, and income.

    Science.gov (United States)

    Bo, Anne; Zinckernagel, Line; Krasnik, Allan; Petersen, Jorgen H; Norredam, Marie

    2015-10-01

    Increasing global migration has made immigrants' health an important topic worldwide. We examined the effect of country of birth, migrant status (refugee/family-reunified) and income on coronary heart disease (CHD) incidence. This was a historical prospective register-based cohort study. The study cohort consisted of immigrants above 18 years from non-Western countries who had obtained a residence permit in Denmark as a refugee (n = 29,045) or as a family-reunified immigrant (n = 28,435) from 1 January 1993-31 December 1999 and a Danish-born reference population (n = 229,918). First-time CHD incidence was identified from 1 January 1993-31 December 2007. Incidence ratios for 11 immigrant groups were estimated using Cox regression analysis. Immigrants from Afghanistan, Iraq, Turkey, Eastern Europe and Central Asia, South Asia, the Former Yugoslavia, and the Middle East and North Africa had significantly higher incidences of CHD (hazard ratio (HR) = 1.36; 95% confidence interval (CI): 1.05-1.75 to HR = 2.86; 95% CI: 2.01-4.08) compared with Danish-born people. Immigrants from Somalia, South and Middle America, Sub-Saharan Africa and women from East Asia and the Pacific did not differ significantly from Danish-born people, whereas immigrant men from East Asia and the Pacific had a significantly lower incidence (HR = 0.32; 95% CI: 0.17-0.62). When also including migrant status, the higher incidences were reduced. Refugee men (HR = 1.35; 95% CI: 1.11-1.65) and women (HR = 1.33; 95% CI: 1.08-1.65) had a significantly higher incidence of CHD than family-reunified immigrants. When migrant status and income were included simultaneously, the incidences decreased to an insignificant level for most immigrant groups. Most non-Western immigrant groups had a higher incidence of CHD than Danish-born people. The study revealed that migrant status and income are important underlying mechanisms of the effect of country of birth on CHD. © The European

  20. Effect of olive waste (Husk on behavior of cement paste

    Directory of Open Access Journals (Sweden)

    Sharaf Alkheder

    2016-12-01

    Full Text Available Jordan is a famous country in terms of olive trees agriculture that resulted in a mass production of olive oil products. The huge amounts of olive waste (husk that resulted from olives processing to produce olive oil represent an environmental challenge in the country. The idea in this paper comes to use olive waste as a partial replacement for Portland cement in cement paste to conserve the environment, reduce cement consumption and increase cost efficiency. The wastes were burned properly in an oven and maintained for 6 h until it was fully transformed into ashes. Then, the oven was turned off and ashes were allowed to cool. After cooling, the material passed sieve #200 were used. The sieved ashes were used in the cement mix as a partial cement replacement for making the mortar and cement paste. Normal consistency and setting time were determined as well as soundness, compressive strength. Results indicated that normal consistency of the cement pastes containing different percentage of olive waste is somehow lower than that of the ordinary cement paste and slightly decreases with increasing the percentage. The results also indicated that the compressive strength of hardened blended cement paste containing different percentages of olive waste slightly decrease with olive waste content at 3, 7, and 28 days.

  1. The contemporary cement cycle of the United States

    Science.gov (United States)

    Kapur, A.; Van Oss, H. G.; Keoleian, G.; Kesler, S.E.; Kendall, A.

    2009-01-01

    A country-level stock and flow model for cement, an important construction material, was developed based on a material flow analysis framework. Using this model, the contemporary cement cycle of the United States was constructed by analyzing production, import, and export data for different stages of the cement cycle. The United States currently supplies approximately 80% of its cement consumption through domestic production and the rest is imported. The average annual net addition of in-use new cement stock over the period 2000-2004 was approximately 83 million metric tons and amounts to 2.3 tons per capita of concrete. Nonfuel carbon dioxide emissions (42 million metric tons per year) from the calcination phase of cement manufacture account for 62% of the total 68 million tons per year of cement production residues. The end-of-life cement discards are estimated to be 33 million metric tons per year, of which between 30% and 80% is recycled. A significant portion of the infrastructure in the United States is reaching the end of its useful life and will need to be replaced or rehabilitated; this could require far more cement than might be expected from economic forecasts of demand for cement. ?? 2009 Springer Japan.

  2. Systemic Measures and Legislative and Organizational Frameworks Aimed at Preventing or Mitigating Drug Shortages in 28 European and Western Asian Countries

    Science.gov (United States)

    Bochenek, Tomasz; Abilova, Vafa; Alkan, Ali; Asanin, Bogdan; de Miguel Beriain, Iñigo; Besovic, Zeljka; Vella Bonanno, Patricia; Bucsics, Anna; Davidescu, Michal; De Weerdt, Elfi; Duborija-Kovacevic, Natasa; Fürst, Jurij; Gaga, Mina; Gailīte, Elma; Gulbinovič, Jolanta; Gürpınar, Emre U.; Hankó, Balázs; Hargaden, Vincent; Hotvedt, Tor A.; Hoxha, Iris; Huys, Isabelle; Inotai, Andras; Jakupi, Arianit; Jenzer, Helena; Joppi, Roberta; Laius, Ott; Lenormand, Marie-Camille; Makridaki, Despina; Malaj, Admir; Margus, Kertu; Marković-Peković, Vanda; Miljković, Nenad; de Miranda, João L.; Primožič, Stanislav; Rajinac, Dragana; Schwartz, David G.; Šebesta, Robin; Simoens, Steven; Slaby, Juraj; Sović-Brkičić, Ljiljana; Tesar, Tomas; Tzimis, Leonidas; Warmińska, Ewa; Godman, Brian

    2018-01-01

    Drug shortages have been identified as a public health problem in an increasing number of countries. This can negatively impact on the quality and efficiency of patient care, as well as contribute to increases in the cost of treatment and the workload of health care providers. Shortages also raise ethical and political issues. The scientific evidence on drug shortages is still scarce, but many lessons can be drawn from cross-country analyses. The objective of this study was to characterize, compare, and evaluate the current systemic measures and legislative and organizational frameworks aimed at preventing or mitigating drug shortages within health care systems across a range of European and Western Asian countries. The study design was retrospective, cross-sectional, descriptive, and observational. Information was gathered through a survey distributed among senior personnel from ministries of health, state medicines agencies, local health authorities, other health or pharmaceutical pricing and reimbursement authorities, health insurance companies and academic institutions, with knowledge of the pharmaceutical markets in the 28 countries studied. Our study found that formal definitions of drug shortages currently exist in only a few countries. The characteristics of drug shortages, including their assortment, duration, frequency, and dynamics, were found to be variable and sometimes difficult to assess. Numerous information hubs were identified. Providing public access to information on drug shortages to the maximum possible extent is a prerequisite for performing more advanced studies on the problem and identifying solutions. Imposing public service obligations, providing the formal possibility to prescribe unlicensed medicines, and temporary bans on parallel exports are widespread measures. A positive finding of our study was the identification of numerous bottom-up initiatives and organizational frameworks aimed at preventing or mitigating drug shortages. The

  3. Advanced cementation concepts

    International Nuclear Information System (INIS)

    Howard, C.G.

    1989-10-01

    The purpose of this programme of work was to investigate whether improvements could be made to existing formulations for cement suitable for the immobilization of intermediate level radioactive waste. Two additives were selected, microsilica and limestone flour. Improvements to the cement were only slight. (author)

  4. Preparation of hydraulic cement

    Energy Technology Data Exchange (ETDEWEB)

    1921-08-28

    A process for the preparation of hydraulic cement by the use of oil-shale residues is characterized in that the oil-shale refuse is mixed with granular basic blast-furnace slag and a small amount of portland cement and ground together.

  5. Low force cementation.

    Science.gov (United States)

    Wilson, P R

    1996-07-01

    The marginal adaptation of full coverage restorations is adversely affected by the introduction of luting agents of various minimum film thicknesses during the cementation process. The increase in the marginal opening may have long-term detrimental effects on the health of both pulpal and periodontal tissues. The purpose of this study was to determine the effects of varying seating forces (2.5, 12.5, 25 N), venting, and cement types on post-cementation marginal elevation in cast crowns. A standardized cement space of 40 microns was provided between a machined gold crown and a stainless steel die. An occlusal vent was placed that could be opened or closed. The post-cementation crown elevation was measured, following the use of two commercially available capsulated dental cements (Phosphacap, and Ketac-cem Applicap). The results indicate that only the combination of Ketac-Cem Applicap and crown venting produced post-cementation crown elevation of less than 20 microns when 12.5 N seating force was used. Higher forces (25 N) and venting were required for comparable seating when using Phosphacap (19 microns). The amount of force required to allow maximum seating of cast crowns appears to be cement specific, and is reduced by effective venting procedures.

  6. Cementation process study

    International Nuclear Information System (INIS)

    Park, H.H.; Han, K.W.; Ahn, S.J.; Choi, K.S.; Lee, M.W.; Ryu, Y.K.

    1985-01-01

    In the cementation process study, in 1984, design of the waste treatment simulator was finished for the first step. We can experience not only the operation of solidification system but the design and construction of comming large scale plant through the design of cementation process. (Author)

  7. Peritoneal Dialysis in Western Countries

    NARCIS (Netherlands)

    Struijk, Dirk G.

    2015-01-01

    Peritoneal dialysis (PD) for the treatment of end-stage renal failure was introduced in the 1960s. Nowadays it has evolved to an established therapy that is complementary to hemodialysis (HD), representing 11% of all patients treated worldwide with dialysis. Despite good clinical outcomes and

  8. Modified pavement cement concrete

    Science.gov (United States)

    Botsman, L. N.; Ageeva, M. S.; Botsman, A. N.; Shapovalov, S. M.

    2018-03-01

    The paper suggests design principles of pavement cement concrete, which covers optimization of compositions and structures at the stage of mixture components selection due to the use of plasticizing agents and air-retaining substances that increase the viability of a concrete mixture. It also demonstrates advisability of using plasticizing agents together with air-retaining substances when developing pavement concrete compositions, which provides for the improvement of physical and mechanical properties of concrete and the reduction of cement binding agent consumption thus preserving strength indicators. The paper shows dependences of the main physical-mechanical parameters of concrete on cement consumption, a type and amount of additives.

  9. Radioactive waste cementation

    International Nuclear Information System (INIS)

    Soriano B, A.

    1996-01-01

    This research was carried out to develop the most adequate technique to immobilize low and medium-activity radioactive waste. different brands of national cement were used, portland and pozzolanic cement. Prismatic and cylindrical test tubes were prepared with different water/cement (W/C) relationship. Additives such a as clay and bentonite were added in some other cases. Later, the properties of these test tubes were evaluated. Properties such as: mechanical resistance, immersion resistance, lixiviation and porosity resistance. Cement with the highest mechanical resistance values, 62,29 MPa was pozzolanic cement for a W/C relationship of 0,35. It must be mentioned that the other types of cements reached a mechanical resistance over 10 MPa, a value indicated by the international standards for transportation and storage of low and medium-activity radioactive waste at a superficial level. However, in the case of immersion resistance, Sol cement (portland type I) with a W/C relationship of 0,35 reached a compression resistance over 61,92 MPa; as in the previous cases, the other cements reached a mechanical resistance > 10 MPa. Regarding porosity, working with W/C relationships = 0,35 0,40 and 0,45, without additives and with additives, the percentage of porosity found for all cements is lower than 40% percentage indicated by international standards. With regard to the lixiviation test, pozzolanic cement best retained Cesium-137 and Cobalt-60, and increased its advantages when bentonite was added, obtaining a lixiviation rate of 2,02 x E-6 cm/day. Sol cement also improved its properties when bentonite was added and obtained a lixiviation rate of 2,84 x E-6 cm/day for Cesium-137. However, Cobalt-60 is almost completely retained with the 3 types of cement with or without additives, reaching the limits indicated by the international standards for the lixiviation rate of beta-gamma emitter < 5,00E-4 cm/day. Characterizing the final product involves the knowledge of its

  10. Tympanoplasty with ionomeric cement

    DEFF Research Database (Denmark)

    Kjeldsen, A D; Grøntved, A M

    2000-01-01

    with isolated erosion of the long incus process have been treated with a new surgical technique in which the ossicular chain was rebuilt with ionomeric cement. The results in hearing performance (mean pure-tone average (PTA) 0.5, 1 and 2 kHz) were evaluated pre- and post-surgery, and compared to those...... of > 10 dB, in 4 there was a slight improvement and in 2 a decline. The difference was not statistically significant. Hearing improvement using ionomeric cement in type II tympanoplasty was satisfactory. Reconstruction of the ossicular chain with ionomeric cement is recommended, as the procedure is easy...

  11. Assessment of radon and thoron exhalation from Indian cement samples using smart radon and thoron monitors

    International Nuclear Information System (INIS)

    Sahoo, B.K.; Sapra, B.K; Agarwal, T.K.; Babu, D.A.R.

    2015-01-01

    It has been established that primarily, there exist two important sources that contribute to indoor radon/thoron namely, the exhalation from ground and building materials. The contribution from ground, although significant, is treated as a case of existing exposure. Then, the only source that can be controlled during the construction is the choice of building materials. Cement is an important building material used in the construction of houses and buildings in India. The housing sector is the largest cement consumer with 53% of the total Indian cement demand followed by the infrastructure sector. India with a production capacity of 165 million tones (MT) (in 2007), was the second largest cement producer in the world after China. The industry produces various types of cement like ordinary portland cement (OPC), Portland pozzolana cement (PPC), portland slag cement (PSC), rapid hardening portland cement (RHPC), sulphate resistant cement (SRC) and white cement (WC). Several studies have been undertaken on cement in various countries because it is commonly used in bulk quantities in the construction of houses and other civil structures. However, detailed information regarding the radon and thoron exhalation into indoor air from various types of cements produced in India is scarce. In the present work, an attempt has been made to systematically determine the radon and thoron exhalation from 50 cement samples (17 OPC, 15 PPC, 04 PSC, 06 RHPC, 04 WC and 04 SRC). The data thus obtained is used to calculate the indoor radon and thoron source term and the contributed inhalation dose based on a model room structure. The measured values of radon and thoron exhalation from cement samples were comparable with the reported values in other countries. This study showed that the cement samples used in civil constructions do not pose any radiological hazard to the Indian population. (author)

  12. the Danish cement industry

    OpenAIRE

    la Cour, Lisbeth Funding; Møllgård, Peter

    2001-01-01

    We test econometrically whether the sole Danish producer of cement holds a dominant position in the Danish market for (grey) cement. In import penetration tests, we find that its pricing and quantity decisions are independent of import price and quantity, implying that it can act to a considerable extent independently of its competitors. We also test whether it can act independently of its customers and find that its demand is inelastic with respect to its price. It thus holds a dominant posi...

  13. Energy optimization and reduction of carbon footprint in cement manufacturing

    Energy Technology Data Exchange (ETDEWEB)

    Gallestey, Eduardo; Crosley, Gabriela; Wilson, Andrew; Maier, Urs; Hoppler, Rolf; Boerrnert, Thomas

    2010-09-15

    Cement producers are large consumers of thermal and electrical energy, which are only available at steadily increasing costs. Efforts to reduce demands by using higher efficiency equipment and substituting -fuels and raw materials to lower production costs have been addressed in recent years. Under the Kyoto Protocol industrialised countries agreed to reduce their collective greenhouse gas emissions. Cement producers as some of the largest emitters of CO2 have been especially challenged to find new and innovative ways to reduce greenhouse gas emissions. This paper summarise some ABB technologies developed to assist the cement industry to meet these goals.

  14. From an “Internationalist Woman” to “Just another Asian Immigrant”: Transformation of Japanese Women’s Self-Image before and after Permanent Settlement in a Western Country

    Directory of Open Access Journals (Sweden)

    Atsuko KAWAKAMI

    2009-11-01

    Full Text Available Young middle class Japanese women who speak English identify themselves as career-oriented “internationalist women.” They hold positive self-images; however, their self-images become convoluted with negative images as they experience changes in their lives. When they marry white males and become permanent residents in Western countries, their self-identities transform into “just another Asian immigrant” out of many. Many Japanese wives of white husbands deny their association with their compatriots when they actually do associate with other Japanese immigrant women. They also deny racial factors in their attraction to their white husbands. I argue that these behaviors are harnessed to redevelop a self-identity by renouncing the stereotypical images of Eurocentric Japanese women. This paper will describe the transformation of Japanese women’s self-images before and after permanent settlement in a Western country and the process of their redevelopment of self-identity.

  15. Fabrication of Phosphate Cement with High Integrity

    International Nuclear Information System (INIS)

    Yang, Jae Hwan; Lee, Chang Hwa; Heo, Cheol Min; Jeon, Min Ku; Kang, Kweon Ho

    2011-01-01

    As the development of industrial society has accelerated, hazardous wastes are generated as well. According to the 1986 statistics of U.S.A, each person made 40 tons of waste in America that year. Treatment of radioactive waste is one of the most important and serious problems related to waste treatments, because its radioactivity and decaying heat have harmful effects to human and environment for a long time. Nuclear developed countries have used conventional method of treatment such as vitrification or cementation in order to stabilize and solidify radioactive waste. Although the former guarantees the formation of high leaching resistant and durable waste form, it requires several hundred (or even more than one thousand) temperature to melt glass frit. This process generates secondary waste volatilized, as well as being non-economical. Cement technology played a role of immobilizing low and middle class wastes. It has advantages of low temperature setting, low cost, easy process, etc. The alkalinity of ordinary cement, however, constrains the utility of cement to the solidification of alkaline waste. In addition, leachability and mechanical strength of cements are not quite appropriate for the stabilization of high level waste. In this regard, chemically bonded phosphate cement(CBPC), which sets by an acid-base reaction, is a potentially expectable material for immobilization of radioactive waste. CBPC not only sets at room temperature, but also encapsulates various isotopes chemically. The performance of CBPC can be enhanced by the addition of fly ash, sand, wollastonite, etc. This study aims at fabricating the CBPC containing fly ash with high integrity. Morphology, microstructure, and compressive strength are evaluated using SEM, and digital compressing machine

  16. Cement for Oil Well Cementing Operations in Ghana

    African Journals Online (AJOL)

    Michael

    For Portland cement to qualify as oil well cement, the chemical and physical properties must meet ..... Reservoir Engineering, Stanford University,. Stanford, California, pp. ... Construction”, PhD Thesis, Kwame Nkrumah. University of Science ...

  17. ULTRA-LIGHTWEIGHT CEMENT

    Energy Technology Data Exchange (ETDEWEB)

    Fred Sabins

    2001-10-23

    The objective of this project is to develop an improved ultra-lightweight cement using ultra-lightweight hollow glass spheres (ULHS). Work reported herein addresses tasks performed in the fourth quarter as well as the other three quarters of the past year. The subjects that were covered in previous reports and that are also discussed in this report include: Analysis of field laboratory data of active cement applications from three oil-well service companies; Preliminary findings from a literature review focusing on problems associated with ultra-lightweight cements; Summary of pertinent information from Russian ultra-lightweight cement literature review; and Comparison of compressive strengths of ULHS systems using ultrasonic and crush methods Results reported from the fourth quarter include laboratory testing of ULHS systems along with other lightweight cement systems--foamed and sodium silicate slurries. These comparison studies were completed for two different densities (10.0 and 11.5 lb/gal) and three different field application scenarios. Additional testing included the mechanical properties of ULHS systems and other lightweight systems. Studies were also performed to examine the effect that circulation by centrifugal pump during mixing has on breakage of ULHS.

  18. Internal globalization of Western Balkan

    Directory of Open Access Journals (Sweden)

    Vukotić Veselin

    2006-01-01

    Full Text Available What are potential and real effects of the globalization process on the economic connection between Western Balkan countries? What is the crucial change in relations between Western Balkan countries and its economies inexorably brought by globalization? What are the elements of political economy of Western Balkan globalization? What are reflections of the conflict between political and economic areas of Western Balkan? These are some of the issues discuses in this paper.

  19. Concrete = aggregate, cement, water?

    International Nuclear Information System (INIS)

    Jelinek, J.

    1990-01-01

    Concrete for the Temelin nuclear power plant is produced to about 70 different formulae. For quality production, homogeneous properties of aggregates, accurate proportioning devices, technological discipline and systematic inspections and tests should be assured. The results are reported of measuring compression strength after 28 days for different concrete samples. The results of such tests allow reducing the proportion of cement, which brings about considerable savings. Reduction in cement quantities can also be achieved by adding ash to the concrete mixes. Ligoplast, a plasticizer addition is used for improving workability. (M.D). 8 figs

  20. Technology Roadmaps: Cement

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2009-07-01

    To support its roadmap work focusing on key technologies for emissions reductions, the International Energy Agency (IEA) also investigated one particular industry: cement. Cement production includes technologies that are both specific to this industry and those that are shared with other industries (e.g., grinding, fuel preparation, combustion, crushing, transport). An industry specific roadmap provides an effective mechanism to bring together several technology options. It outlines the potential for technological advancement for emissions reductions in one industry, as well as potential cross-industry collaboration.

  1. Reducing cement's CO2 footprint

    Science.gov (United States)

    van Oss, Hendrik G.

    2011-01-01

    The manufacturing process for Portland cement causes high levels of greenhouse gas emissions. However, environmental impacts can be reduced by using more energy-efficient kilns and replacing fossil energy with alternative fuels. Although carbon capture and new cements with less CO2 emission are still in the experimental phase, all these innovations can help develop a cleaner cement industry.

  2. Cement Mason's Curriculum. Instructional Units.

    Science.gov (United States)

    Hendirx, Laborn J.; Patton, Bob

    To assist cement mason instructors in providing comprehensive instruction to their students, this curriculum guide treats both the skills and information necessary for cement masons in commercial and industrial construction. Ten sections are included, as follow: related information, covering orientation, safety, the history of cement, and applying…

  3. Cementation of liquid radioactive waste

    International Nuclear Information System (INIS)

    Efremenkov, V.

    2004-01-01

    The cementation methods for immobilisation of radioactive wastes are discussed in terms of methodology, chemistry and properties of the different types of cements as well as the worldwide experience in this field. Two facilities for cementation - DEWA and MOWA - are described in details

  4. Cementing a wellbore using cementing material encapsulated in a shell

    Energy Technology Data Exchange (ETDEWEB)

    Aines, Roger D.; Bourcier, William L.; Duoss, Eric B.; Spadaccini, Christopher M.; Cowan, Kenneth Michael

    2016-08-16

    A system for cementing a wellbore penetrating an earth formation into which a pipe extends. A cement material is positioned in the space between the wellbore and the pipe by circulated capsules containing the cement material through the pipe into the space between the wellbore and the pipe. The capsules contain the cementing material encapsulated in a shell. The capsules are added to a fluid and the fluid with capsules is circulated through the pipe into the space between the wellbore and the pipe. The shell is breached once the capsules contain the cementing material are in position in the space between the wellbore and the pipe.

  5. Cementing a wellbore using cementing material encapsulated in a shell

    Energy Technology Data Exchange (ETDEWEB)

    Aines, Roger D.; Bourcier, William L.; Duoss, Eric B.; Floyd, III, William C.; Spadaccini, Christopher M.; Vericella, John J.; Cowan, Kenneth Michael

    2017-03-14

    A system for cementing a wellbore penetrating an earth formation into which a pipe extends. A cement material is positioned in the space between the wellbore and the pipe by circulated capsules containing the cement material through the pipe into the space between the wellbore and the pipe. The capsules contain the cementing material encapsulated in a shell. The capsules are added to a fluid and the fluid with capsules is circulated through the pipe into the space between the wellbore and the pipe. The shell is breached once the capsules contain the cementing material are in position in the space between the wellbore and the pipe.

  6. The mechanical effect of the existing cement mantle on the in-cement femoral revision.

    LENUS (Irish Health Repository)

    Keeling, Parnell

    2012-08-01

    Cement-in-cement revision hip arthroplasty is an increasingly popular technique to replace a loose femoral stem which retains much of the original cement mantle. However, some concern exists regarding the retention of the existing fatigued and aged cement in such cement-in-cement revisions. This study investigates whether leaving an existing fatigued and aged cement mantle degrades the mechanical performance of a cement-in-cement revision construct.

  7. Chest radiological findings in pakistani cement mill workers

    International Nuclear Information System (INIS)

    Meo, Sultan A.

    2003-01-01

    Chest radiological findings in Pakistani cement mill workers Even in the 21st century, in developing countries millions of people work daily in dusty environments. They are exposed to different types of health hazards namely, fumes, gases and dust, which are risk factors for developing occupational diseases. Therefore, the aim of this study was to perform chest radiology to determine the occupational hazards of cement dust on the lungs of cement mill workers. This study was carried out in the Department of Physiology, Faculty of Health and Medical Sciences, Hamdard University Karachi, Pakistan, during the period June to August 2000. In this study 50, apparently healthy volunteer male cement mill workers were randomly selected with an average of 13 years exposure with age ranging from 20-60 years. They were matched with 50, healthy male control subjects in terms of age, height, weight and socioeconomic status. Both groups met with exclusion criteria as per standard. Radiology was performed by Trophy radiology. Results: The present study demonstrated 12% of cases with interstitial lung disease and 2% of cases with pleural thickening and chronic bronchitis in cement mill workers. Conclusion: Exposure to cement dust causes interstitial lung disease, pleural thickening and chronic bronchitis in cement mill workers. (author)

  8. Prevalence and Social Determinants of Smoking in 15 Countries from North Africa, Central and Western Asia, Latin America and Caribbean: Secondary Data Analyses of Demographic and Health Surveys.

    Science.gov (United States)

    Sreeramareddy, Chandrashekhar T; Pradhan, Pranil Man Singh

    2015-01-01

    Article 20 of the World Health Organisation Framework Convention on Tobacco Control calls for a cross-country surveillance of tobacco use through population-based surveys. We aimed to provide country-level prevalence estimates for current smoking and current smokeless tobacco use and to assess social determinants of smoking. Data from Demographic and Health Surveys done between 2005 and 2012, among men and women from nine North African, Central and West Asian countries and six Latin American and Caribbean countries were analyzed. Weighted country-level prevalence rates were estimated for 'current smoking' and 'current use of smokeless tobacco (SLT) products' among men and women. In each country, social determinants of smoking among men and women were assessed by binary logistic regression analyses by including men's and women's sampling weights to account for the complex survey design. Prevalence of smoking among men was higher than 40% in Armenia (63.1%), Moldova (51.1%), Ukraine (52%), Azerbaijan (49.8 %), Kyrgyz Republic (44.3 %) and Albania (42.52%) but the prevalence of smoking among women was less than 10% in most countries except Ukraine (14.81%) and Jordan (17.96%). The prevalence of smokeless tobacco use among men and women was less than 5% in all countries except among men in the Kyrgyz Republic (10.6 %). Smoking was associated with older age, lower education and poverty among men and higher education and higher wealth among women. Smoking among both men and women was associated with unskilled work, living in urban areas and being single. Smoking among men was very high in Central and West Asian countries. Social pattern of smoking among women that was different from men in education and wealth should be considered while formulating tobacco control policies in some Central and West Asian countries.

  9. Prevalence and Social Determinants of Smoking in 15 Countries from North Africa, Central and Western Asia, Latin America and Caribbean: Secondary Data Analyses of Demographic and Health Surveys.

    Directory of Open Access Journals (Sweden)

    Chandrashekhar T Sreeramareddy

    Full Text Available Article 20 of the World Health Organisation Framework Convention on Tobacco Control calls for a cross-country surveillance of tobacco use through population-based surveys. We aimed to provide country-level prevalence estimates for current smoking and current smokeless tobacco use and to assess social determinants of smoking.Data from Demographic and Health Surveys done between 2005 and 2012, among men and women from nine North African, Central and West Asian countries and six Latin American and Caribbean countries were analyzed. Weighted country-level prevalence rates were estimated for 'current smoking' and 'current use of smokeless tobacco (SLT products' among men and women. In each country, social determinants of smoking among men and women were assessed by binary logistic regression analyses by including men's and women's sampling weights to account for the complex survey design.Prevalence of smoking among men was higher than 40% in Armenia (63.1%, Moldova (51.1%, Ukraine (52%, Azerbaijan (49.8 %, Kyrgyz Republic (44.3 % and Albania (42.52% but the prevalence of smoking among women was less than 10% in most countries except Ukraine (14.81% and Jordan (17.96%. The prevalence of smokeless tobacco use among men and women was less than 5% in all countries except among men in the Kyrgyz Republic (10.6 %. Smoking was associated with older age, lower education and poverty among men and higher education and higher wealth among women. Smoking among both men and women was associated with unskilled work, living in urban areas and being single.Smoking among men was very high in Central and West Asian countries. Social pattern of smoking among women that was different from men in education and wealth should be considered while formulating tobacco control policies in some Central and West Asian countries.

  10. Blood donation barriers and facilitators of Sub-Saharan African migrants and minorities in Western high-income countries: a systematic review of the literature

    NARCIS (Netherlands)

    Klinkenberg, E. F.; Huis In 't Veld, E. M. J.; de Wit, P. D.; van Dongen, A.; Daams, J. G.; de Kort, W. L. A. M.; Fransen, M. P.

    2018-01-01

    The present study aimed to gain more insight into, and summarise, blood donation determinants among migrants or minorities of Sub-Saharan heritage by systematically reviewing the current literature. Sub-Saharan Africans are under-represented in the blood donor population in Western high-income

  11. Cement manufacture and the environment - Part I: Chemistry and technology

    Science.gov (United States)

    Van Oss, H. G.; Padovani, A.C.

    2002-01-01

    Hydraulic (chiefly portland) cement is the binding agent in concrete and mortar and thus a key component of a country's construction sector. Concrete is arguably the most abundant of all manufactured solid materials. Portland cement is made primarily from finely ground clinker, which itself is composed dominantly of hydraulically active calcium silicate minerals formed through high-temperature burning of limestone and other materials in a kiln. This process requires approximately 1.7 tons of raw materials perton of clinker produced and yields about 1 ton of carbon dioxide (CO2) emissions, of which calcination of limestone and the combustion of fuels each contribute about half. The overall level of CO2 output makes the cement industry one of the top two manufacturing industry sources of greenhouse gases; however, in many countries, the cement industry's contribution is a small fraction of that from fossil fuel combustion by power plants and motor vehicles. The nature of clinker and the enormous heat requirements of its manufacture allow the cement industry to consume a wide variety of waste raw materials and fuels, thus providing the opportunity to apply key concepts of industrial ecology, most notably the closing of loops through the use of by-products of other industries (industrial symbiosis). In this article, the chemistry and technology of cement manufacture are summarized. In a forthcoming companion article (part II), some of the environmental challenges and opportunities facing the cement industry are described. Because of the size and scope of the U.S. cement industry, the analysis relies primarily on data and practices from the United States.

  12. High Y-chromosomal diversity and low relatedness between paternal lineages on a communal scale in the Western European Low Countries during the surname establishment

    OpenAIRE

    Larmuseau, M H D; Boon, N; Vanderheyden, N; Van Geystelen, A; Larmuseau, H F M; Matthys, K; De Clercq, W; Decorte, R

    2015-01-01

    There is limited knowledge on the biological relatedness between citizens and on the demographical dynamics within villages, towns and cities in pre-17th century Western Europe. By combining Y-chromosomal genotypes, in-depth genealogies and surname data in a strict genetic genealogical approach, it is possible to provide insights into the genetic diversity and the relatedness between indigenous paternal lineages within a particular community at the time of the surname adoption. To obtain thes...

  13. Mineral resource of the month: hydraulic cement

    Science.gov (United States)

    van Oss, Hendrik G.

    2012-01-01

    Hydraulic cements are the binders in concrete and most mortars and stuccos. Concrete, particularly the reinforced variety, is the most versatile of all construction materials, and most of the hydraulic cement produced worldwide is portland cement or similar cements that have portland cement as a basis, such as blended cements and masonry cements. Cement typically makes up less than 15 percent of the concrete mix; most of the rest is aggregates. Not counting the weight of reinforcing media, 1 ton of cement will typically yield about 8 tons of concrete.

  14. Cement-latex grouting mortar for cementing boreholes

    Energy Technology Data Exchange (ETDEWEB)

    Kateev, I S; Golyshkina, L A; Gorbunova, I V; Kurochkin, B M; Vakula, Ya V

    1980-01-01

    The need for the development of cement-latex grouting mortar for the purpose of separating strata when reinforcing boreholes at deposits in the Tatar Associated SSR is evaluated. Results of studies of the physical and mechanical properties of cement-latex grouting mortar systems (mortar plus brick) are presented. Formulas for preparing cement-latex grouting mortor are evaluated and results of industrial tests of such mortars shown.

  15. US cement industry

    Energy Technology Data Exchange (ETDEWEB)

    Nisbet, M.A.

    1997-12-31

    This paper describes the cement and concrete industry, and provides data on energy use and carbon dioxide emissions. The potential impact of an energy tax on the industry is briefly assessed. Opportunities identified for reducing carbon dioxide emissions include improved energy efficiency, alternative fuels, and alternative materials. The key factor in determining CO{sub 2} emissions is the level of domestic production. The projected improvement in energy efficiency and the relatively slow growth in domestic shipments indicate that CO{sub 2} emissions in 2000 should be about 5% above the 1990 target. However, due to the cyclical nature of cement demand, emissions will probably be above target levels during peak demand and below target levels during demand troughs. 7 figs., 2 tabs.

  16. Chemical environment in cements

    International Nuclear Information System (INIS)

    Glasser, F.B.; Angus, M.J.; McCulloch, C.E.; Macphee, D.; Rahman, A.A.

    1984-01-01

    The alkalinity of Portland cements is responsible for precipitation and low solubility of many radwastes species. The sources of alkalinity are evaluated and two chemical models, based on experimental and theoretical data presented enabling the effect of blending agents (PFA, silica fume, etc.) to be evaluated and the alkalinity of the system at longer ages predicted. The data take the form of a solubility model which is applicable to non-heat generating wastes. 7 refs., 10 figs

  17. Performance of Cement Containing Laterite as Supplementary Cementing Material

    Directory of Open Access Journals (Sweden)

    Abbas Bukhari, Z. S.

    2013-03-01

    Full Text Available The utilization of different industrial waste, by-products or other materials such as ground granulated blast furnace slag, silica fume, fly ash, limestone, and kiln dust, etc. as supplemen- tary cementing materials has received considerable attention in recent years. A study has been conducted to look into the performance of laterite as Supplementary Cementing Materials (SCM. The study focuses on compressive strength performance of blended cement containing different percentage of laterite. The cement is replaced accordingly with percentage of 2 %, 5 %, 7 % and 10 % by weight. In addition, the effect of use of three chemically different laterites have been studied on physical performance of cement as in setting time, Le-Chatlier expansion, loss on ignition, insoluble residue, free lime and specifically compressive strength of cement cubes tested at the age of 3, 7, and 28 days. The results show that the strength of cement blended with laterite as SCM is enhanced. Key words: Portland cement, supplementary cementing materials (SCM, laterite, compressive strength KUI – 6/2013 Received January 4, 2012 Accepted February 11, 2013

  18. First forum ''BISE'' for: the intelligent energy in the municipalities and the new member states, of candidate countries and western Balkans

    International Nuclear Information System (INIS)

    2004-01-01

    The european commission and the european association of municipalities (Energie Cites) established a permanent ''Intelligent Energy Forum of European Municipalities'' (named BISE Forum) as form of periodical information exchange between municipal associations and other potential partners in Europe. In the framework of the reduction of the sustainable energy gap between the Central and Eastern European Countries and the most advanced energy-efficient EU 15 countries, the aim of this forum is to promote the creation of national energy cities networks, to integrate the initiatives and networks at an European scale and to promote the idea of an European Emergency Plan in order to improve energy efficiency in Eastern European Countries as quickly as possible. This document presents the proceedings and a selection of cases studies linked to the first BISE Forum. (A.L.B.)

  19. Wide-scale utilization of MSWI fly ashes in cement production and its impact on average heavy metal contents in cements: The case of Austria.

    Science.gov (United States)

    Lederer, Jakob; Trinkel, Verena; Fellner, Johann

    2017-02-01

    A number of studies present the utilization of fly ashes from municipal solid waste incineration (MSWI) in cement production as a recycling alternative to landfilling. While there is a lot of research on the impact of MSWI fly ashes utilization in cement production on the quality of concrete or the leaching of heavy metals, only a few studies have determined the resulting heavy metal content in cements caused by this MSWI fly ashes utilization. Making use of the case of Austria, this study (1) determines the total content of selected heavy metals in cements currently produced in the country, (2) designs a scenario and calculates the resulting heavy metal contents in cements assuming that all MSWI fly ashes from Austrian grate incinerators were used as secondary raw materials for Portland cement clinker production and (3) evaluates the legal recyclability of demolished concretes produced from MSWI fly ash amended cements based on their total heavy metal contents. To do so, data from literature and statistics are combined in a material flow analysis model to calculate the average total contents of heavy metals in cements and in the resulting concretes according to the above scenario. The resulting heavy metal contents are then compared (i) to their respective limit values for cements as defined in a new technical guideline in Austria (BMLFUW, 2016), and (ii) to their respective limit values for recycling materials from demolished concrete. Results show that MSWI fly ashes utilization increases the raw material input in cement production by only +0.9%, but the total contents of Cd by +310%, and Hg, Pb, and Zn by +70% to +170%. However these and other heavy metal contents are still below their respective limit values for Austrian cements. The same legal conformity counts for recycling material derived from concretes produced from the MSWI fly ash cements. However, if the MSWI fly ash ratio in all raw materials used for cement production were increased from 0.9% to 22

  20. Barium aluminate cement: its application

    International Nuclear Information System (INIS)

    Drozdz, M.; Wolek, W.

    1975-01-01

    The technology of manufacturing barium aluminate cement from barium sulfate and alumina, using a rotary kiln for firing the clinker is described. The method of granulation of the homogenized charge was used. Conditions of using the ''to mud'' method in industry were indicated. The physical and chemical properties of barium aluminate cement are determined and the quality of several batches of cement prepared on a semi-industrial scale and their suitability for making highly refractory concretes are tested. The optimal composition of the concretes is determined as a function of the mixing water and barium aluminate cement contents. Several experimental batches of concretes were used in the linings of furnaces in the steel industry. The suitability of these cements for use in fields other than steelmaking is examined. It is established that calcium aluminate cement has certain limited applications [fr

  1. Influence of relationship water/cement upon the processing of cements with pozzolana in standard mortar

    Directory of Open Access Journals (Sweden)

    Gener Rizo, M.

    2002-03-01

    Full Text Available The processing of standard mortar is completed following different methods in accordance with the country, but they exist two fundamental tendecies, the ISO and the ASTM. The cuban norm for mechanic-physic tests is based in ISO, and so they use a constant relationship water/cement in the processing of standard mortar a great problem concerning the cement users when they tested those mixed with puzzolanes, because they don't take care of the bigger water needs of those materials. In this work we present an study of the behaviour of Pozzolanic Portland cements (PP-250 elaborates with a fix and changeable relationship water/cement, obtained starting from the fluidity of the pure Portland cement. (P-350 The results obtained shows that the mechanical resistance decreased in cement mortars PP-250 realised with changeable relationship water/cement. So we recommend the adoption of an optional procedure to elaborate a quality mortar with pozzolana cements.

    La elaboración del mortero normalizado se realiza internacionalmente por diferentes métodos, pero existen dos tendencias fundamentales, la enunciada por ISO y por ASTM. La norma cubana de ensayos físico-mecánicos de cemento se basa en la norma ISO, por lo que para la elaboración del mortero normalizado se utiliza una relación agua/cemento constante. Esto ha provocado discrepancias con los usuarios del cemento, especialmente cuando se ensayan los cementos que contienen puzolanas, ya que se plantea que no se tiene en cuenta la mayor demanda de agua de estos materiales. En el presente trabajo se presenta un estudio del comportamiento de cementos Portland Puzolánicos (PP-250 elaborados con una relación agua/ cemento fija y variable, lograda a partir de la fluidez de la pasta de cemento Portland puro (P-350. Los resultados obtenidos indican que se producen disminuciones en la resistencia mecánica en los morteros de cemento PP-250 elaborados con agua/ cemento variable y recomienda la

  2. XRF analysis of portland cement for major and trace elements

    International Nuclear Information System (INIS)

    Abdunnabi, A. R.

    2012-12-01

    Libyan portland cement produced in several factories around the country, in Lip tis, Zoltan, Souq-Elkamis, Dernah and El-Fatach, were analyzed for quantitative major and trace elements and mineral content, which were compered with those imported from Spain, Romania, Cyprus, and Egypt. X-ray fluorescence spectro X lab 2000 spectrometer equipped with Rh-and X-ray tube was used for the analysis of various samples. The detector Si(Li) with a resolution of 148 eV at Mn K-a=5.9 keV facilitates the determination of a wide range of elements from sodium to uranium, with a detection limit at sub levels. Cement samples in the powder form were analyzed using the pellet-technique. The pellets were prepared by mixing 4g of the cement powder with 0.9 g of binder (HWC) and pressed at high pressure. A ful analysis including, background counting, matrix correction and all relevant corrections were achieved automatically by XLAB 2000 software package. For major and trace elements X RF results were higher for most of the elements than those analyzed with atomic absorption spectrometry. The mineral content showed that Libyan cement is comparable to the imported ones, also the Libyan cement meets the requirements of the international specifications of the portland cement. (Author)

  3. Stability of reinforced cemented backfills

    International Nuclear Information System (INIS)

    Mitchell, R.J.; Stone, D.M.

    1987-01-01

    Mining with backfill has been the subject of several international meetings in recent years and a considerable research effort is being applied to improve both mining economics and ore recovery by using backfill for ground support. Classified mill tailings sands are the most commonly used backfill material but these fine sands must be stabilized before full ore pillar recovery can be achieved. Normal portland cement is generally used for stabilization but the high cost of cement prohibits high cement usage. This paper considers the use of reinforcements in cemented fill to reduce the cement usage. It is concluded that strong cemented layers at typical spacings of about 3 meters in a low cement content bulk fill can reinforce the fill and reduce the overall cement usage. Fibre reinforcements introduced into strong layers or into bulk fills are also known to be effective in reducing cement usage. Some development work is needed to produce the ideal type of anchored fibre in order to realize economic gains from fibre-reinforced fills

  4. High Y-chromosomal diversity and low relatedness between paternal lineages on a communal scale in the Western European Low Countries during the surname establishment.

    Science.gov (United States)

    Larmuseau, M H D; Boon, N; Vanderheyden, N; Van Geystelen, A; Larmuseau, H F M; Matthys, K; De Clercq, W; Decorte, R

    2015-07-01

    There is limited knowledge on the biological relatedness between citizens and on the demographical dynamics within villages, towns and cities in pre-17th century Western Europe. By combining Y-chromosomal genotypes, in-depth genealogies and surname data in a strict genetic genealogical approach, it is possible to provide insights into the genetic diversity and the relatedness between indigenous paternal lineages within a particular community at the time of the surname adoption. To obtain these insights, six Flemish communities were selected in this study based on the differences in geography and historical development. After rigorous selection of appropriate DNA donors, low relatedness between Y chromosomes of different surnames was found within each community, although there is co-occurrence of these surnames in each community since the start of the surname adoption between the 14th and 15th century. Next, the high communal diversity in Y-chromosomal lineages was comparable with the regional diversity across Flanders at that time. Moreover, clinal distributions of particular Y-chromosomal lineages between the communities were observed according to the clinal distributions earlier observed across the Flemish regions and Western Europe. No significant indication for genetic differences between communities with distinct historical development was found in the analysis. These genetic results provide relevant information for studies in historical sciences, archaeology, forensic genetics and genealogy.

  5. Developing Low-Clinker Ternary Blends for Indian Cement Industry

    Science.gov (United States)

    Pal, Aritra

    2018-05-01

    In today's scenario cement-concrete has become the backbone of infrastructure development. The use of concrete is increasing day by day and so does cement. One of the major concerns is that the cement manufacturing contributes 7% of total man-made CO2 emission in the environment. At the same time India being a developing country secured the second position in cement production. On the other hand solid waste management is one of the growing problems in India. As we are one of the major contributors in this situation so, the time has come to think about the sustainable alternatives. From various researches it has been observed that the low clinker cement can be suitable option. In the present paper we have tried to develop a low clinker ternary blend for Indian cement industry using the concept of synergetic behavior of fly ash-limestone reaction and formation of more stable monocarboaluminate hydrate and hemicarboaluminate hydrate. 30% fly ash and 15% limestone and 5% gypsum have been used as supplementary cementing material for replacing 50% clinker. The mechanical properties like, compressive strength, have been studied for the fly ash limestone ternary blends cements and the results have been compared with the other controlled blends and ternary blends. The effect of intergrinding of constituent materials has shown a comparable properties which can be used for various structural application. The effect of dolomitic limestone has also been studied in fly ash limestone ternary blends and the result shows the relation between compressive strength and dolomite content is inversely proportional.

  6. Compressive Strength Of Rice Husk Ash-Cement Sandcrete Blocks ...

    African Journals Online (AJOL)

    There is growing demand for alternative, low-cost building material in developing countries. The effect of partial substitution of ordinary Portland cement with Rice Husk Ash (RHA) on the compressive strength of hollow sandcrete block was investigated through laboratory experimental procedures. The specific gravity, initial ...

  7. Using dehydrated cement paste as new type of cement additive

    NARCIS (Netherlands)

    Yu, R.; Shui, Z.H.; Dong, J

    2013-01-01

    This paper presents an experimental study, including evaluation and modification, on using dehydrated cement paste (DCP) as a new type of cement additive. After a series of processes, normal DCP (N-DCP) was produced as before and a modified form of DCP (M-DCP) was produced as well. The cementitious

  8. Biomass for green cement

    Energy Technology Data Exchange (ETDEWEB)

    Cumming, R. [Lafarge Canada Inc., Calgary, AB (Canada)

    2006-07-01

    Lafarge examined the use of waste biomass products in its building materials and provided background information on its operations. Cement kiln infrastructure was described in terms of providing access to shipping, rail and highways; conveying and off-loading equipment; having large storage facilities; and, offering continuous monitoring and stack testing. The presentation identified the advantages and disadvantages of a few different biomass cases such as coal; scrap tires; non-recyclable household waste; and processed biomass. A chart representing landfill diversion rates was presented and the presentation concluded with a discussion of energy recovery and recycling. 1 tab., figs.

  9. Process of preparing hydraulic cement

    Energy Technology Data Exchange (ETDEWEB)

    1919-12-11

    A process of preparing hydraulic cement from oil shale or shale coke is characterized in that the oil shale or shale coke after the distillation is burned long and hot to liberate the usual amount of carbonic acid and then is fine ground to obtain a slow hardening hydraulic cement.

  10. Health hazards of cement dust

    International Nuclear Information System (INIS)

    Meo, Sultan A.

    2004-01-01

    ven in the 21st century, millions of people are working daily in a dusty environment. They are exposed to different types of health hazards such as fume, gases and dust, which are risk factors in developing occupational disease. Cement industry is involved in the development of structure of this advanced and modern world but generates dust during its production. Cement dust causes lung function impairment, chronic obstructive lung disease, restrictive lung disease, pneumoconiosis and carcinoma of the lungs, stomach and colon. Other studies have shown that cement dust may enter into the systemic circulation and thereby reach the essentially all the organs of body and affects the different tissues including heart, liver, spleen, bone, muscles and hairs and ultimately affecting their micro-structure and physiological performance. Most of the studies have been previously attempted to evaluate the effects of cement dust exposure on the basis of spirometry or radiology, or both. However, collective effort describing the general effects of cement dust on different organ and systems in humans or animals, or both has not been published. Therefore, the aim of this review is to gather the potential toxic effects of cement dust and to minimize the health risks in cement mill workers by providing them with information regarding the hazards of cement dust. (author)

  11. Ceramic microspheres for cementing applications

    NARCIS (Netherlands)

    2011-01-01

    A method and apparatus for manufacturing ceramic microspheres from industrial slag. The microspheres have a particle size of about 38 microns to about 150 microns. The microspheres are used to create a cement slurry having a density of at least about 11 lbs/g. The resultant cement slurry may then be

  12. Ceramic microspheres for cementing applications

    NARCIS (Netherlands)

    2010-01-01

    A method and apparatus for manufacturing ceramic microspheres from industrial slag. The microspheres have a particle size of about 38 microns to about 150 microns. The microspheres are used to create a cement slurry having a density of at least about 11 lbs/g. The resultant cement slurry may then be

  13. Ceramic microspheres for cementing applications

    NARCIS (Netherlands)

    2012-01-01

    A method and apparatus for manufacturing ceramic microspheres from industrial slag. The microspheres have a particle size of about 38 microns to about 150 microns. The microspheres are used to create a cement slurry having a density of at least about 11 lbs/g. The resultant cement slurry may then be

  14. Corrosion resistant cemented carbide

    International Nuclear Information System (INIS)

    Hong, J.

    1990-01-01

    This paper describes a corrosion resistant cemented carbide composite. It comprises: a granular tungsten carbide phase, a semi-continuous solid solution carbide phase extending closely adjacent at least a portion of the grains of tungsten carbide for enhancing corrosion resistance, and a substantially continuous metal binder phase. The cemented carbide composite consisting essentially of an effective amount of an anti-corrosion additive, from about 4 to about 16 percent by weight metal binder phase, and with the remaining portion being from about 84 to about 96 percent by weight metal carbide wherein the metal carbide consists essentially of from about 4 to about 30 percent by weight of a transition metal carbide or mixtures thereof selected from Group IVB and of the Periodic Table of Elements and from about 70 to about 96 percent tungsten carbide. The metal binder phase consists essentially of nickel and from about 10 to about 25 percent by weight chromium, the effective amount of an anti-corrosion additive being selected from the group consisting essentially of copper, silver, tine and combinations thereof

  15. Ghetto poverty and pollution in Egypt: a deadly threat for western countries caused by new and infectious mutants. A cultural, social and microbiological synopsis.

    Science.gov (United States)

    Wassili, J H; Baradaeus, Cyril

    2012-10-01

    Egypt, whose soil germinated the first civilization, monotheism, refined ethics and culture of sharing the abundance of extracted natural resources among its populace became the crucible proliferating de-novo genotypes of organic and moral maladies. The enigma is these mutations are synchronized by several factors, namely; failing medical health, if there is any, abundant filth, cultural bankruptcy, over population, dogmatic militarism, societal deprivation and characterization, etc. These domineering ingredients fossilized Egypt as of 1952 coup in an irrevocable national apoptosis, together with the crippled social justice and imbalanced distribution of wealth among Egyptians, rates of bacterial and viral evolution to second generation resistant to known medical interventions are expected to exponentially accelerate. Therefore, it deemed essential to elaborate on pollution and psychosis-induced inflammations and grievous crimes evoked by dogmatic cults at the breeding source, e.g., ghettos and sporadic locations of the homeless in Cairo, Alexandria and Upper Egyptian villages. While this second generation of viral and bacterial diseases could labor plagues threatening the precariously maintained so-called social fabric of Middle Eastern countries, that are uniquely segregating its populace according to their dogmatic affiliations and soaked into intolerance, it would definitely compromise the integrity of the expensively managed medical care system of developed countries.

  16. Estimation of CO2 emissions from China’s cement production: Methodologies and uncertainties

    International Nuclear Information System (INIS)

    Ke, Jing; McNeil, Michael; Price, Lynn; Khanna, Nina Zheng; Zhou, Nan

    2013-01-01

    In 2010, China’s cement output was 1.9 Gt, which accounted for 56% of world cement production. Total carbon dioxide (CO 2 ) emissions from Chinese cement production could therefore exceed 1.2 Gt. The magnitude of emissions from this single industrial sector in one country underscores the need to understand the uncertainty of current estimates of cement emissions in China. This paper compares several methodologies for calculating CO 2 emissions from cement production, including the three main components of emissions: direct emissions from the calcination process for clinker production, direct emissions from fossil fuel combustion and indirect emissions from electricity consumption. This paper examines in detail the differences between common methodologies for each emission component, and considers their effect on total emissions. We then evaluate the overall level of uncertainty implied by the differences among methodologies according to recommendations of the Joint Committee for Guides in Metrology. We find a relative uncertainty in China’s cement-related emissions in the range of 10 to 18%. This result highlights the importance of understanding and refining methods of estimating emissions in this important industrial sector. - Highlights: ► CO 2 emission estimates are critical given China’s cement production scale. ► Methodological differences for emission components are compared. ► Results show relative uncertainty in China’s cement-related emissions of about 10%. ► IPCC Guidelines and CSI Cement CO 2 and Energy Protocol are recommended

  17. Challenges of the growing African cement market – environmental issues, regulative framework, and quality infrastructure requirements

    Directory of Open Access Journals (Sweden)

    Schmidt Wolfram

    2018-01-01

    Full Text Available The African cement, concrete and construction business is growing at rapid pace. The cement sales are expected to grow rapidly until 2050. The number of newly built cement plants increases dramatically and in addition more cements are being imported from outside the continent, e.g. from Turkey, Pakistan, Indonesia, and China, driven by overcapacities in the countries of origin. This causes a high number of potentials and challenges at the same time. Newly built cement plants can operate directly at best technological state of the art and thus incorporate more sustainable technologies as well as produce new and more sustainable products such as cements blended with sustainable supplementary cementitious materials such as calcined clays, and industrial or agricultural by products. At the same time the new variety of binding agent as well as the international imports, which are driven by price considerations, make the cement market prone to quality scatter. This puts pressure on the quality control regulations and institutions to ensure safety of construction, healthy application, and environmental safety for the population. The paper presents possible solutions to build up the rapidly increasing African cement production more sustainably than in the rest of the world as well as the related challenges and obstacles that need to be overcome. Based on experiences with a series of pan-African cement testing laboratory proficiency schemes conclusions are made on technical, regulative and political level.

  18. Insulin detemir in the management of type 2 diabetes in non-Western countries: safety and effectiveness data from the A₁chieve observational study.

    Science.gov (United States)

    Zilov, Alexey; El Naggar, Nabil; Shah, Siddharth; Shen, Chunduo; Haddad, Jihad

    2013-09-01

    This subgroup analysis of the A₁chieve study examined data from 15,545 people who started treatment with insulin detemir ± oral glucose-lowering drugs in routine clinical care. A₁chieve was a 24-week, international, prospective, non-interventional study of people with type 2 diabetes from non-Western nations starting treatment with basal insulin detemir, bolus insulin aspart or biphasic insulin aspart 30, alone or in combination, to evaluate their safety and effectiveness in routine clinical practice. HbA₁c for the global cohort improved after 24 weeks from 9.5 ± 1.6% by -2.0 ± 1.6% [80 ± 17 by -22 ± 17 mmol/mol] (-2.1 ± 1.6% [-23 ± 17 mmol/mol] for insulin-naïve participants; -1.6 ± 1.7% [-17 ± 19 mmol/mol] for prior insulin users). Fasting plasma glucose and postprandial plasma glucose were also significantly reduced (pquality of life improved over 24 weeks for all people starting treatment with insulin detemir. People with type 2 diabetes in poor glycaemic control starting treatment with insulin detemir reported significant improvements in glycaemic control with improved treatment tolerability, irrespective of prior treatment and geographical region, after 24 weeks. Copyright © 2013. Published by Elsevier Ireland Ltd.

  19. Nuclear Energy in Western Europe: At the End of its Business Cycle? A review of policies in selected West European countries and Russia

    Energy Technology Data Exchange (ETDEWEB)

    Tangen, Kristian

    1997-12-31

    A series of seminars were held in Norway in 1995-97 focusing on nuclear energy policies, mainly in Europe. The key questions were: (1) What are the major driving forces behind the development of the nuclear industry?, and (2) Are we seeing the end of the nuclear energy era, or will we actually discover that the nuclear energy is moving towards its second blossom? This report summarizes the discussions at the seminars and discusses the above questions. The nature of the driving forces depends on the country in question. In France and Russia the nuclear sectors are large and prestigious and the course is difficult to change. In Germany and Sweden, political parties have adopted an anti-nuclear attitude and the issue is controversial, involving arguments both pro and con. The British nuclear sector has come to the end of the road. The main driving force has been the deregulation of the electricity market. In all countries, climate issues, independence from energy import, prestige and low costs have been arguments against close-downs. Massive expansion of nuclear power in Europe is unlikely. However, new plants might appear in Finland, Turkey or France. It is likely that technological development of the nuclear power sector, if any, will come in Asia. It is unclear whether this sector will benefit from climate issues. Renewable energy could become an important competitor if enough electricity could be produced. A state has been reached in which nuclear energy is both difficult to expand and to phase out. The nuclear energy issues are unlikely to affect the European gas market significantly. 53 refs., 10 refs., 13 tabs.

  20. Nuclear Energy in Western Europe: At the End of its Business Cycle? A review of policies in selected West European countries and Russia

    Energy Technology Data Exchange (ETDEWEB)

    Tangen, Kristian

    1998-12-31

    A series of seminars were held in Norway in 1995-97 focusing on nuclear energy policies, mainly in Europe. The key questions were: (1) What are the major driving forces behind the development of the nuclear industry?, and (2) Are we seeing the end of the nuclear energy era, or will we actually discover that the nuclear energy is moving towards its second blossom? This report summarizes the discussions at the seminars and discusses the above questions. The nature of the driving forces depends on the country in question. In France and Russia the nuclear sectors are large and prestigious and the course is difficult to change. In Germany and Sweden, political parties have adopted an anti-nuclear attitude and the issue is controversial, involving arguments both pro and con. The British nuclear sector has come to the end of the road. The main driving force has been the deregulation of the electricity market. In all countries, climate issues, independence from energy import, prestige and low costs have been arguments against close-downs. Massive expansion of nuclear power in Europe is unlikely. However, new plants might appear in Finland, Turkey or France. It is likely that technological development of the nuclear power sector, if any, will come in Asia. It is unclear whether this sector will benefit from climate issues. Renewable energy could become an important competitor if enough electricity could be produced. A state has been reached in which nuclear energy is both difficult to expand and to phase out. The nuclear energy issues are unlikely to affect the European gas market significantly. 53 refs., 10 refs., 13 tabs.

  1. 21 CFR 888.4200 - Cement dispenser.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Cement dispenser. 888.4200 Section 888.4200 Food... DEVICES ORTHOPEDIC DEVICES Surgical Devices § 888.4200 Cement dispenser. (a) Identification. A cement dispenser is a nonpowered syringe-like device intended for use in placing bone cement (§ 888.3027) into...

  2. A cement based syntactic foam

    International Nuclear Information System (INIS)

    Li Guoqiang; Muthyala, Venkata D.

    2008-01-01

    In this study, a cement based syntactic foam core was proposed and experimentally investigated for composite sandwich structures. This was a multi-phase composite material with microballoon dispersed in a rubber latex toughened cement paste matrix. A trace amount of microfiber was also incorporated to increase the number of mechanisms for energy absorption and a small amount of nanoclay was added to improve the crystal structure of the hydrates. Three groups of cement based syntactic foams with varying cement content were investigated. A fourth group of specimens containing pure cement paste were also prepared as control. Each group contained 24 beam specimens. The total number of beam specimens was 96. The dimension of each beam was 30.5 cm x 5.1 cm x 1.5 cm. Twelve foam specimens from each group were wrapped with plain woven 7715 style glass fabric reinforced epoxy to prepare sandwich beams. Twelve cubic foam specimens, three from each group, with a side length of 5.1 cm, were also prepared. Three types of testing, low velocity impact test and four-point bending test on the beam specimens and compression test on the cubic specimens, were conducted to evaluate the impact energy dissipation, stress-strain behavior, and residual strength. Scanning electron microscope (SEM) was also used to examine the energy dissipation mechanisms in the micro-length scale. It was found that the cement based syntactic foam has a higher capacity for dissipating impact energy with an insignificant reduction in strength as compared to the control cement paste core. When compared to a polymer based foam core having similar compositions, it was found that the cement based foam has a comparable energy dissipation capacity. The developed cement based syntactic foam would be a viable alternative for core materials in impact-tolerant composite sandwich structures

  3. Crown and bridge cements: clinical applications.

    Science.gov (United States)

    Bunek, Sabiha S; Powers, John M

    2012-12-01

    Cement selection can be confusing because factors such as substrate, the type of restoration, and patient needs must be considered. Some substrates require additional treatment before cementation. This article describes the most commonly used traditional crown and bridge cements (GI and RMGI) used for metal and metal-ceramic restorations, and resin cements used for all-ceramic restorations. Advantages, disadvantages, indications, and contraindications of cements have been reviewed. Recommended uses of cements for metal, ceramic, and laboratory composite restorations have been presented. General guidelines for surface treatment ot silica- and zirconia-based restorations when using resin cements have been discussed.

  4. Cement/slag chemistry studies

    International Nuclear Information System (INIS)

    Glasser, F.P.; Macphee, D.; Atkins, M.; Beckley, N.; Carson, S.O.; Wilding, C.R.; McHugh, G.

    1988-01-01

    The performance of cement-based matrices intended for radwaste immobilization is assessed. The long-term performance of the matrix is characterized by thermodynamic evaluation of experimental data. The results are presented in a general form, amenable to a range of specific formulations. The interaction of specific radwaste components with cements has been studied, using Iodine as an example. It occurs as both I - and IO 3 - species, but these differ sharply in sorption characteristics. The effect of ionizing radiation of the pH and E h of cement matrices is reported. (author)

  5. Cements in Radioactive Waste Disposal

    International Nuclear Information System (INIS)

    Glasser, F.P.

    2013-01-01

    The use of cement and concrete to immobilise radioactive waste is complicated by the wide- ranging nature of inorganic cementing agents available as well as the range of service environments in which cement is used and the different functions expected of cement. For example, Portland cement based concretes are widely used as structural materials for construction of vaults and tunnels. These constructions may experience a long pre-closure performance lifetime during which they are required to protect against collapse and ingress of water: strength and impermeability are key desirable characteristics. On the other hand, cement and concrete may be used to form backfills, ranging in permeability. Permeable formulations allow gas readily to escape, while impermeable barriers retard radionuclide transport and reduce access of ground water to the waste. A key feature of cements is that, while fresh, they pass through a fluid phase and can be formed into any shape desired or used to infiltrate other materials thereby enclosing them into a sealed matrix. Thereafter, setting and hardening is automatic and irreversible. Where concrete is used to form structural elements, it is also natural to use cement in other applications as it minimises potential for materials incompatibility. Thus cement- mainly Portland cement- has been widely used as an encapsulant for storage, transport and as a radiation shield for active wastes. Also, to form and stabilise structures such as vaults and silos. Relative to other potential matrices, cement also has a chemical immobilisation potential, reacting with and binding with many radionuclides. The chemical potential of cements is essentially sacrificial, thus limiting their performance lifetime. However performance may also be required in the civil engineering sense, where strength is important, so many factors, including a geochemical description of service conditions, may require to be assessed in order to predict performance lifetime. The

  6. Cements in Radioactive Waste Disposal

    Energy Technology Data Exchange (ETDEWEB)

    Glasser, F. P. [University of Aberdeen, Scotland (United Kingdom)

    2013-09-15

    The use of cement and concrete to immobilise radioactive waste is complicated by the wide- ranging nature of inorganic cementing agents available as well as the range of service environments in which cement is used and the different functions expected of cement. For example, Portland cement based concretes are widely used as structural materials for construction of vaults and tunnels. These constructions may experience a long pre-closure performance lifetime during which they are required to protect against collapse and ingress of water: strength and impermeability are key desirable characteristics. On the other hand, cement and concrete may be used to form backfills, ranging in permeability. Permeable formulations allow gas readily to escape, while impermeable barriers retard radionuclide transport and reduce access of ground water to the waste. A key feature of cements is that, while fresh, they pass through a fluid phase and can be formed into any shape desired or used to infiltrate other materials thereby enclosing them into a sealed matrix. Thereafter, setting and hardening is automatic and irreversible. Where concrete is used to form structural elements, it is also natural to use cement in other applications as it minimises potential for materials incompatibility. Thus cement- mainly Portland cement- has been widely used as an encapsulant for storage, transport and as a radiation shield for active wastes. Also, to form and stabilise structures such as vaults and silos. Relative to other potential matrices, cement also has a chemical immobilisation potential, reacting with and binding with many radionuclides. The chemical potential of cements is essentially sacrificial, thus limiting their performance lifetime. However performance may also be required in the civil engineering sense, where strength is important, so many factors, including a geochemical description of service conditions, may require to be assessed in order to predict performance lifetime. The

  7. Simulating Spatial Growth Patterns in Developing Countries: an Agent Based Modelling Approach. A Case of Shama in the Western Region of Ghana

    Science.gov (United States)

    Inkoom, J. N.

    2011-12-01

    In Sub-Saharan Africa, rapid urban growth is characterized by prolific expansion of unplanned (informal) structures, and unguided spatial expansion. These unguided expansions by human agents have outstripped the regulatory capacities of Central and Local government. Governmental institutions in finding solutions to the unguided expansion in unplanned use of land have to call for the modelling of what influences the spatial decision and role of human agents in the growth of informal settlement. The objective of the study is to simulate spatial growth pattern of settlements in the Shama district using an agent based model. The study was conducted within a framework of NetLogo. The NetLogo assisted to incorporate and simulate driving forces that affect location decision-making by households and the growth of informal settlement. A survey was conducted to obtain household location decision preferences. The development of unplanned settlement has been a function of land price, proximity to economic centre's, household economic potential, and the location decision-making patterns of households. The exploratory analysis found particularly that majority of spontaneous development took place on areas liable to floods suggesting that some structures fall outside the required building regulations. The application of the proposed model indicates its potential to improve urban planning policies and decision-making processes in emerging cities of developing countries. Also, the result of the simulation suggests potential preferential location for residential development. The research justifies an approach in the area of simulating urban dynamics with agent-based models.

  8. Does cement mantle thickness really matter?

    OpenAIRE

    Caruana, J.

    2008-01-01

    The thickness of the cement mantle around the femoral component of total hip replacements is a contributing factor to aseptic loosening and revision. Nevertheless, various designs of stems and surgical tooling lead to cement mantles of differing thicknesses. This thesis is concerned with variability in cement thickness around the Stanmore Hip, due to surgical approach, broach size and stem orientation, and its effects on stress and cracking in the cement. The extent to which cement mantle thi...

  9. Alternative Fuels in Cement Production

    DEFF Research Database (Denmark)

    Larsen, Morten Boberg

    The substitution of alternative for fossil fuels in cement production has increased significantly in the last decade. Of these new alternative fuels, solid state fuels presently account for the largest part, and in particular, meat and bone meal, plastics and tyre derived fuels (TDF) accounted...... for the most significant alternative fuel energy contributors in the German cement industry. Solid alternative fuels are typically high in volatile content and they may differ significantly in physical and chemical properties compared to traditional solid fossil fuels. From the process point of view......, considering a modern kiln system for cement production, the use of alternative fuels mainly influences 1) kiln process stability (may accelerate build up of blockages preventing gas and/or solids flow), 2) cement clinker quality, 3) emissions, and 4) decreased production capacity. Kiln process stability...

  10. Calcium Aluminate Cement Hydration Model

    Directory of Open Access Journals (Sweden)

    Matusinović, T.

    2011-01-01

    Full Text Available Calcium aluminate cement (AC is a very versatile special cement used for specific applications. As the hydration of AC is highly temperature dependent, yielding structurally different hydration products that continuously alter material properties, a good knowledge of thermal properties at early stages of hydration is essential. The kinetics of AC hydration is a complex process and the use of single mechanisms models cannot describe the rate of hydration during the whole stage.This paper examines the influence of temperature (ϑ=5–20 °C and water-to-cement mass ratio (mH /mAC = 0.4; 0.5 and 1.0 on hydration of commercial iron-rich AC ISTRA 40 (producer: Istra Cement, Pula, Croatia, which is a part of CALUCEM group, Figs 1–3. The flow rate of heat generation of cement pastes as a result of the hydration reactions was measured with differential microcalorimeter. Chemically bonded water in the hydrated cement samples was determined by thermo-gravimetry.Far less heat is liberated when cement and water come in contact for the first time, Fig. 1, than in the case for portland cement (PC. Higher water-to-cement ratio increases the heat evolved at later ages (Fig. 3 due to higher quantity of water available for hydration. A significant effect of the water-to-cement ratio on the hydration rate and hydration degree showed the importance of water as being the limiting reactant that slows down the reaction early. A simplified stoichiometric model of early age AC hydration (eq. (8 based on reaction schemes of principal minerals, nominally CA, C12A7 and C4AF (Table 1, was employed. Hydration kinetics after the induction period (ϑ < 20 °C had been successfully described (Fig. 4 and Table 2 by a proposed model (eq. (23 which simultaneously comprised three main mechanisms: nucleation and growth, interaction at phase boundary, and mass transfer. In the proposed kinetic model the nucleation and growth is proportional to the amount of reacted minerals (eq

  11. Rheological measurements on cement grouts

    International Nuclear Information System (INIS)

    Dalton, M.J.

    1986-06-01

    This report describes the techniques which have been developed at Winfrith for assessing the rheological properties of cement grouts. A discussion of the theory of rheology and its application to cement is given and the methodology for calibrating a special paddle measuring system for a commercial viscometer is described. The use of the system for determining flow curves, equilibrium viscosity, viscosity as a function of shearing time and structure changes is also discussed. (author)

  12. Natural gamma-emitting radionuclides in egyptian cement

    International Nuclear Information System (INIS)

    El Arabi, A.M.; Abbady, A.; El Kamel, A.H.; Nosier, A.; Moustafa, A.

    2005-01-01

    Samples of cement manufactured in Egypt and the various raw materials, which compose the product, have been analyzed using gamma-spectroscopy, in order to determine the concentration of natural radionuclides and associated radiological hazard. The mean of specific activity due to all the three radionuclides (226 R a, 232 T h and 40 K ) were found to be 20±4 , 11± 2, 320 ± 18 (gypsum), 41 ±8, 27± 5, 410± 27 (clay), 58 ± 11, 18 3, 321± 20 (Iron ore) and 37.6 ± 6, 11.8 ± 3, 178.6 ± 15 Bq.kg-1 (Portland cement), respectively. 40 K concentration could not be detected in Slag; limestone; Sulphate resistant cement; Clinker and White cement, while the mean activity concentrations of 226 R a and 232 T h are 239 ± 16, 48.7 ± 7; 31.5 ±5, 10 ± 2; 47 ± 7, 20 ± 4; 23 ± 5, 10.4 ± 3 and 23 ± 5, 11 ±3 Bq.kg-1, respectively. The measured activity concentrations of these natural radionuclides were compared with data of some countries. The present values are in the same range and sometimes less than those in other countries

  13. Natural gamma-emitting radionuclides in egyptian cement

    International Nuclear Information System (INIS)

    El-Arabi, A.M.; Abbady, A.; El-Kamel, A.H.; Nosier, A.; Moustafa, A.

    2005-01-01

    Samples of cement manufactured in Egypt and the various raw materials, which compose the product, have been analyzed using gamma-spectroscopy, in order to determine the concentration of natural radionuclides and associated radiological hazard. The mean of specific activity due to all the three radionuclides (226 R a, 232 T h and 40 K ) were found to be 20 ± 4 , 11 ± 2, 320 ± 18 (gypsum), 41 ± 8, 27 ± 5, 410 ± 27 (clay), 58 ± 11, 18 3, 321 ± 20 (Iron ore) and 37.6 ± 6, 11.8 ± 3, 178.6 ± 15 Bq.kg-1 (Portland cement), respectively. 40 K concentration could not be detected in Slag; limestone; Sulphate resistant cement; Clinker and White cement, while the mean activity concentrations of 226 R a and 232 T h are 239 ± 16, 48.7 ± 7; 31.5 ± 5, 10 ± 2; 47 3 ± 7, 20 ± 4; 23 ± 5, 10.4 ± 3 and 23 ± 5, 11 ± 3 Bq.kg-1, respectively. The measured activity concentrations of these natural radionuclides were compared with data of some countries. The present values are in the same range and sometimes less than those in other countries

  14. Cement pulmonary embolism after vertebroplasty.

    Science.gov (United States)

    Sifuentes Giraldo, Walter Alberto; Lamúa Riazuelo, José Ramón; Gallego Rivera, José Ignacio; Vázquez Díaz, Mónica

    2013-01-01

    In recent years, the use of vertebral cementing techniques for vertebroplasty and kyphoplasty has spread for the treatment of pain associated with osteoporotic vertebral compression fractures. This is also associated with the increased incidence of complications related with these procedures, the most frequent being originated by leakage of cementation material. Cement can escape into the vertebral venous system and reach the pulmonary circulation through the azygous system and cava vein, producing a cement embolism. This is a frequent complication, occurring in up to 26% of patients undergoing vertebroplasty but, since most patients have no clinical or hemodynamical repercussion, this event usually goes unnoticed. However, some serious, and even fatal cases, have been reported. We report the case of a 74-year-old male patient who underwent vertebroplasty for persistent pain associated with osteoporotic L3 vertebral fracture and who developed a cement leak into the cava vein and right pulmonary artery during the procedure. Although he developed a pulmonary cement embolism, the patient remained asymptomatic and did not present complications during follow-up. Copyright © 2012 Elsevier España, S.L. All rights reserved.

  15. Calcium Orthophosphate Cements and Concretes

    Directory of Open Access Journals (Sweden)

    Sergey V. Dorozhkin

    2009-03-01

    Full Text Available In early 1980s, researchers discovered self-setting calcium orthophosphate cements, which are a bioactive and biodegradable grafting material in the form of a powder and a liquid. Both phases form after mixing a viscous paste that after being implanted, sets and hardens within the body as either a non-stoichiometric calcium deficient hydroxyapatite (CDHA or brushite, sometimes blended with unreacted particles and other phases. As both CDHA and brushite are remarkably biocompartible and bioresorbable (therefore, in vivo they can be replaced with newly forming bone, calcium orthophosphate cements represent a good correction technique for non-weight-bearing bone fractures or defects and appear to be very promising materials for bone grafting applications. Besides, these cements possess an excellent osteoconductivity, molding capabilities and easy manipulation. Furthermore, reinforced cement formulations are available, which in a certain sense might be described as calcium orthophosphate concretes. The concepts established by calcium orthophosphate cement pioneers in the early 1980s were used as a platform to initiate a new generation of bone substitute materials for commercialization. Since then, advances have been made in the composition, performance and manufacturing; several beneficial formulations have already been introduced as a result. Many other compositions are in experimental stages. In this review, an insight into calcium orthophosphate cements and concretes, as excellent biomaterials suitable for both dental and bone grafting application, has been provided.

  16. The Western Sahara conflict I

    African Journals Online (AJOL)

    Polisario unilaterally declared a "Saharawi Arab Democratic Republic" (27 Feb. 1976). Since .... Furthermore, Frente Polisario managed to keep the Western Sahara question on .... these countries and their fragile ethnic and political balance.

  17. Western Sufism

    DEFF Research Database (Denmark)

    Sedgwick, Mark

    Western Sufism is sometimes dismissed as a relatively recent "new age" phenomenon, but in this book, Mark Sedgwick argues that it actually has very deep roots, both in the Muslim world and in the West. In fact, although the first significant Western Sufi organization was not established until 1915......, the first Western discussion of Sufism was printed in 1480, and Western interest in some of the ideas that are central to Sufi thought goes back to the thirteenth century. Sedgwick starts with the earliest origins of Western Sufism in late antique Neoplatonism and early Arab philosophy, and traces later......, the year in which the first Western Sufi order based not on the heritage of the European Middle Ages, Renaissance and Enlightenment, but rather on purely Islamic models, was founded. Later developments in this and other orders are also covered. Western Sufism shows the influence of these origins...

  18. Low pH Cements

    International Nuclear Information System (INIS)

    Savage, David; Benbow, Steven

    2007-05-01

    The development of low-pH cements for use in geological repositories for radioactive waste stems from concerns over the potential for deleterious effects upon the host rock and other EBS materials (notably bentonite) under the hyperalkaline conditions (pH > 12) of cement pore fluids. Low pH cement (also known as low heat cement) was developed by the cement industry for use where large masses of cement (e.g. dams) could cause problems regarding heat generated during curing. In low pH cements, the amount of cement is reduced by substitution of materials such as fly ash, blast furnace slag, silica fume, and/or non-pozzolanic silica flour. SKB and Posiva have ruled out the use of blast furnace slag and fly-ash and are focusing on silica fume as a blending agent. Currently, no preferred composition has been identified by these agencies. SKB and Posiva have defined a pH limit ≤ 11 for cement grout leachates. To attain this pH, blending agents must comprise at least 50 wt % of dry materials. Because low pH cement has little, or no free portlandite, the cement consists predominantly of calcium silicate hydrate (CSH) gel with a Ca/Si ratio ≤ 0.8. Although there are potential implications for the performance of the spent fuel and cladding due to the presence of hyperalkaline fluids from cement, the principal focus for safety assessment lies with the behaviour of bentonite. There are a number of potential constraints on the interaction of hyperalkaline cement pore fluids with bentonite, including mass balance, thermodynamic issues, mass transport, and kinetics, but none of these is likely to be limiting if conventional OPC cements are employed in repository construction. Nevertheless: Low-pH cements may supply approximately 50 % less hydroxyl ions than conventional OPC for a given volume of cement, but mass balance constraints are complicated by the uncertainty concerning the type of secondary minerals produced during cement-bentonite interaction. The change of aqueous

  19. Low pH Cements

    Energy Technology Data Exchange (ETDEWEB)

    Savage, David; Benbow, Steven [Quintessa Ltd., Henley-on-Thames (United Kingdom)

    2007-05-15

    The development of low-pH cements for use in geological repositories for radioactive waste stems from concerns over the potential for deleterious effects upon the host rock and other EBS materials (notably bentonite) under the hyperalkaline conditions (pH > 12) of cement pore fluids. Low pH cement (also known as low heat cement) was developed by the cement industry for use where large masses of cement (e.g. dams) could cause problems regarding heat generated during curing. In low pH cements, the amount of cement is reduced by substitution of materials such as fly ash, blast furnace slag, silica fume, and/or non-pozzolanic silica flour. SKB and Posiva have ruled out the use of blast furnace slag and fly-ash and are focusing on silica fume as a blending agent. Currently, no preferred composition has been identified by these agencies. SKB and Posiva have defined a pH limit {<=} 11 for cement grout leachates. To attain this pH, blending agents must comprise at least 50 wt % of dry materials. Because low pH cement has little, or no free portlandite, the cement consists predominantly of calcium silicate hydrate (CSH) gel with a Ca/Si ratio {<=} 0.8. Although there are potential implications for the performance of the spent fuel and cladding due to the presence of hyperalkaline fluids from cement, the principal focus for safety assessment lies with the behaviour of bentonite. There are a number of potential constraints on the interaction of hyperalkaline cement pore fluids with bentonite, including mass balance, thermodynamic issues, mass transport, and kinetics, but none of these is likely to be limiting if conventional OPC cements are employed in repository construction. Nevertheless: Low-pH cements may supply approximately 50 % less hydroxyl ions than conventional OPC for a given volume of cement, but mass balance constraints are complicated by the uncertainty concerning the type of secondary minerals produced during cement-bentonite interaction. The change of aqueous

  20. Development of cement material using inorganic additives

    International Nuclear Information System (INIS)

    Toyohara, Masumitsu; Satou, Tatsuaki; Wada, Mikio; Ishii, Tomoharu; Matsuo, Kazuaki.

    1997-01-01

    Inorganic admixtures to enhance the fluidity of cement material was developed. These admixtures turned into easy to immobilize the miscellaneous radioactive waste using cement material. It was found that the ζ potential of cement particles was directly proportional to the content of the inorganic admixtures in cement paste and the particles of cement were dispersed at the high ζ potential. The condensed sodium phosphate, which was the main component of the inorganic admixtures, retarded the dissolution of Ca 2+ ion from the cement, and generated the colloids by incorporating dissolved Ca 2+ ion. The cement material containing the inorganic admixtures was found to have the same mechanical strength and adsorption potential of radionuclides in comparison to normal cement materials. It was confirmed that the cement material containing the inorganic admixture was effectively filled gaps of miscellaneous radioactive waste. (author)

  1. Development of high-performance blended cements

    Science.gov (United States)

    Wu, Zichao

    2000-10-01

    This thesis presents the development of high-performance blended cements from industrial by-products. To overcome the low-early strength of blended cements, several chemicals were studied as the activators for cement hydration. Sodium sulfate was discovered as the best activator. The blending proportions were optimized by Taguchi experimental design. The optimized blended cements containing up to 80% fly ash performed better than Type I cement in strength development and durability. Maintaining a constant cement content, concrete produced from the optimized blended cements had equal or higher strength and higher durability than that produced from Type I cement alone. The key for the activation mechanism was the reaction between added SO4 2- and Ca2+ dissolved from cement hydration products.

  2. Utilization of the national Portland cement for immobilizing radioactive wastes - Physical characteristics

    International Nuclear Information System (INIS)

    Rzyski, B.M.; Suarez, A.A.

    1988-01-01

    This paper shows the results obtained in the study of the national Portland cement, P320, as matrix for radioactive nitric waste incorporation. Cement use practice in other countries is common for this purposes and demonstrates to be cheap and accessible when low and medium level wastes are immobilized. Some of physical characteristics as: homogeneity,mechanical strenght, setting and porosity are analysed due to water-cement ratio and salt contents. Those characteristics which are proper of the final product, must be controlled in such way to assure a long time integrity of the wasteform. The establishment of process and quality control criteria are based in such kind of data. (author) [pt

  3. Polymer-cement interactions towards improved wellbore cement fracture sealants

    Science.gov (United States)

    Beckingham, B. S.; Iloejesi, C.; Minkler, M. J.; Schindler, A. K.; Beckingham, L. E.

    2017-12-01

    Carbon capture, utilization, and storage (CCUS) in deep geologic formations is a promising means of reducing point source emissions of CO2. In these systems, CO2 is captured at the source and then injected to be utilized (eg. in enhanced oil recovery or as a working fluid in enhanced geothermal energy plants) or stored in geologic formations such as depleted oil and gas reservoirs or saline aquifers. While CCUS in subsurface systems could aid in reducing atmospheric CO2 emissions, the potential for CO2 leakage from these systems to overlying formations remains a major limitation and poses a significant risk to the security of injected CO2. Thus, improved materials for both initial wellbore isolation and repairing leakage pathways that develop over time are sought. One approach for the repair of cement fractures in wellbore (and other) systems is the injection of polymer materials into the fracture with a subsequent environmentally dependent (temperature, pressure, pH, etc.) densification or solidification. Here, we aim to investigate novel polymer materials for use to repair leaking wellbores in the context of CCUS. We synthesize and fully characterize a series of novel polymer materials and utilize a suite of analysis techniques to examine polymer-cement interactions at a range of conditions (namely temperature, pressure and pH). Initial findings will be leveraged to design novel polymer materials for further evaluation in polymer-cement composite cores, cement fracture healing, and the aging behavior of healed cements.

  4. THE USE OF SISAL FIBRE AS REINFORCEMENT IN CEMENT BASED COMPOSITES

    OpenAIRE

    Tolêdo Filho,Romildo Dias; Joseph,Kuruvilla; Ghavami,Khosrow; England,George Leslie

    1999-01-01

    ABSTRACT The inclusion of fibre reinforcement in concrete, mortar and cement paste can enhance many of the engineering properties of the basic materials, such as fracture toughness, flexural strength and resistance to fatigue, impact, thermal shock and spalling. In recent years, a great deal of interest has been created worldwide on the potential applications of natural fibre reinforced, cement based composites. Investigations have been carried out in many countries on various mechanical prop...

  5. International students' experience of a western medical school: a mixed methods study exploring the early years in the context of cultural and social adjustment compared to students from the host country.

    Science.gov (United States)

    McGarvey, A; Brugha, R; Conroy, R M; Clarke, E; Byrne, E

    2015-07-02

    Few studies have addressed the challenges associated with international students as they adapt to studying medicine in a new host country. Higher level institutions have increasing numbers of international students commencing programmes. This paper explores the experiences of a cohort of students in the early years of medical school in Ireland, where a considerable cohort are from an international background. A mixed exploratory sequential study design was carried out with medical students in the preclinical component of a five year undergraduate programme. Data for the qualitative phase was collected through 29 semi-structured interviews using the peer interview method. Thematic analysis from this phase was incorporated to develop an online questionnaire combined with components of the Student Adaptation to College Questionnaire and Student Integration Questionnaire. First year students were anonymously surveyed online. The Mokken Scaling procedure was used to investigate the students' experiences, both positive and negative. Three main themes are identified; social adjustment, social alienation and cultural alienation. The response rate for the survey was 49% (467 Respondents). The Mokken Scaling method identified the following scales (i) Positive experience of student life; (ii) Social alienation, which comprised of negative items about feeling lonely, not fitting in, being homesick and (iii) Cultural alienation, which included the items of being uncomfortable around cultural norms of dress and contact between the sexes. With the threshold set to H = 0.4. Subscales of the positive experiences of student life scale are explored further. Overall student adjustment to a western third level college was good. Students from regions where cultural distance is greatest reported more difficulties in adjusting. Students from these regions also demonstrate very good adaptation. Some students from the host country and more similar cultural backgrounds were also

  6. Recent developments in the cement industry: a comparative study between Mexico and India

    Directory of Open Access Journals (Sweden)

    Ganesh Babu Kumaran

    2008-10-01

    Full Text Available Since early twentieth century, the use of cement has become a popular and strategic product for economic growth of every country. In India as in Mexico, the first factories began in the earlier twentieth century, India is nowadays the world’s second largest producer and Mexico is the third firm in cement production, despite being the tenth world producer. The eighties have significate for both countries major structural changes in its economy, which have radically altered the structure and functioning of the cement industry and even more during the decade of the nineties. This article discusses the recent performance of the cement industry in both countries, compares the dynamics and causes that gave rise to these changes. It examines changes in the structure of domestic market in both countries and the strategies employed by large companies that operate in both, including a brief analysis of the role of transnational corporations in their development at the stage of globalization and liberalization of markets that characterizes the last two decades. Finally, it explores the great changes that make possible the growth and expansion of the cement industry during the period, based on technological change, the determinants of competitiveness and the role of economic policies in the development of industry in both countries.

  7. Seepage/Cement Interactions

    International Nuclear Information System (INIS)

    Carpenter, D.

    2000-01-01

    The Development Plan (CRWMS M andO 1999a) pertaining to this task defines the work scopes and objectives for development of various submodels for the Physical and Chemical Environment Abstraction Model for TSPA-LA. The Development Plan (CRWMS M andO 1999a) for this specific task establishes that an evaluation be performed of the chemical reactions between seepage that has entered the drift and concrete which might be used in the repository emplacement drifts. The Development Plan (CRWMS M andO 1999a) then states that the potential effects of these water/grout reactions on chemical conditions in the drift be assessed factoring in the influence of carbonation and the relatively small amount of grout. This task is also directed at: (1) developing a conceptualization of important cement/seepage interactions and potential impacts on EBS performance, (2) performing a screening analysis to assess the importance of cement/seepage interactions. As the work progresses and evolves on other studies, specifically the Engineered Barrier System: Physical and Chemical Environment (P andCE) Model (in progress), many of the issues associated with items 1 and 2, above, will be assessed. Such issues include: (1) Describing the mineralogy of the specified cementitious grout and its evolution over time. (2) Describing the composition of the water before contacting the grout. (3) Developing reasonable upper-bound estimates for the composition of water contacting grout, emphasizing pH and concentrations for anions such as sulfate. (4) Evaluating the equilibration of cement-influenced water with backfill and gas-phase CO 2 . (5) Developing reasonable-bound estimates for flow rate of affected water into the drift. The concept of estimating an ''upper-bound'' range for reaction between the grout and the seepage, particularly in terms of pH is based on equilibrium being established between the seepage and the grout. For example, this analysis can be based on equilibrium being established as

  8. Following “the Roots” of Kratom (Mitragyna speciosa): The Evolution of an Enhancer from a Traditional Use to Increase Work and Productivity in Southeast Asia to a Recreational Psychoactive Drug in Western Countries

    Science.gov (United States)

    Cinosi, Eduardo; Martinotti, Giovanni; Simonato, Pierluigi; Singh, Darshan; Demetrovics, Zsolt; Roman-Urrestarazu, Andres; Bersani, Francesco Saverio; Vicknasingam, Balasingam; Piazzon, Giulia; Li, Jih-Heng; Yu, Wen-Jing; Kapitány-Fövény, Máté; Farkas, Judit; Di Giannantonio, Massimo; Corazza, Ornella

    2015-01-01

    The use of substances to enhance human abilities is a constant and cross-cultural feature in the evolution of humanity. Although much has changed over time, the availability on the Internet, often supported by misleading marketing strategies, has made their use even more likely and risky. This paper will explore the case of Mitragyna speciosa Korth. (kratom), a tropical tree used traditionally to combat fatigue and improve work productivity among farm populations in Southeast Asia, which has recently become popular as novel psychoactive substance in Western countries. Specifically, it (i) reviews the state of the art on kratom pharmacology and identification; (ii) provides a comprehensive overview of kratom use cross-culturally; (iii) explores the subjective experiences of users; (iv) identifies potential risks and side-effects related to its consumption. Finally, it concludes that the use of kratom is not negligible, especially for self-medication, and more clinical, pharmacological, and socioanthropological studies as well as a better international collaboration are needed to tackle this marginally explored phenomenon. PMID:26640804

  9. Following “the Roots” of Kratom (Mitragyna speciosa: The Evolution of an Enhancer from a Traditional Use to Increase Work and Productivity in Southeast Asia to a Recreational Psychoactive Drug in Western Countries

    Directory of Open Access Journals (Sweden)

    Eduardo Cinosi

    2015-01-01

    Full Text Available The use of substances to enhance human abilities is a constant and cross-cultural feature in the evolution of humanity. Although much has changed over time, the availability on the Internet, often supported by misleading marketing strategies, has made their use even more likely and risky. This paper will explore the case of Mitragyna speciosa Korth. (kratom, a tropical tree used traditionally to combat fatigue and improve work productivity among farm populations in Southeast Asia, which has recently become popular as novel psychoactive substance in Western countries. Specifically, it (i reviews the state of the art on kratom pharmacology and identification; (ii provides a comprehensive overview of kratom use cross-culturally; (iii explores the subjective experiences of users; (iv identifies potential risks and side-effects related to its consumption. Finally, it concludes that the use of kratom is not negligible, especially for self-medication, and more clinical, pharmacological, and socioanthropological studies as well as a better international collaboration are needed to tackle this marginally explored phenomenon.

  10. A modified PMMA cement (Sub-cement) for accelerated fatigue testing of cemented implant constructs using cadaveric bone.

    Science.gov (United States)

    Race, Amos; Miller, Mark A; Mann, Kenneth A

    2008-10-20

    Pre-clinical screening of cemented implant systems could be improved by modeling the longer-term response of the implant/cement/bone construct to cyclic loading. We formulated bone cement with degraded fatigue fracture properties (Sub-cement) such that long-term fatigue could be simulated in short-term cadaver tests. Sub-cement was made by adding a chain-transfer agent to standard polymethylmethacrylate (PMMA) cement. This reduced the molecular weight of the inter-bead matrix without changing reaction-rate or handling characteristics. Static mechanical properties were approximately equivalent to normal cement. Over a physiologically reasonable range of stress-intensity factor, fatigue crack propagation rates for Sub-cement were higher by a factor of 25+/-19. When tested in a simplified 2 1/2-D physical model of a stem-cement-bone system, crack growth from the stem was accelerated by a factor of 100. Sub-cement accelerated both crack initiation and growth rate. Sub-cement is now being evaluated in full stem/cement/femur models.

  11. 76 FR 76760 - Gray Portland Cement and Cement Clinker From Japan

    Science.gov (United States)

    2011-12-08

    ... and Cement Clinker From Japan Determination On the basis of the record \\1\\ developed in the subject... duty order on gray Portland cement and cement clinker from Japan would be likely to lead to... and Cement Clinker from Japan: Investigation No. 731- TA-461 (Third Review). By order of the...

  12. Seating load parameters impact on dental ceramic reinforcement conferred by cementation with resin-cements.

    LENUS (Irish Health Repository)

    Addison, Owen

    2010-09-01

    Cementation of all-ceramic restorations with resin-cements has been demonstrated to reduce the incidence of fracture in service. The aim was to investigate the influence of loading force and loading duration applied during cementation on the reinforcement conferred by a resin-cement on a leucite reinforced glass-ceramic.

  13. Cement radwaste solidification studies third annual report

    International Nuclear Information System (INIS)

    Brown, D.J.; James, J.M.; Lee, D.J.; Smith, D.L.; Walker, A.T.

    1982-03-01

    This report summarises cement radwaste studies carried out at AEE Winfrith during 1981 on the encapsulation of medium and low active waste in cement. During the year more emphasis has been placed on the work which is directly related to the solidification of SGHWR active sludge. Information has been obtained on the properties of 220 dm 3 drums of cemented waste. The use of cement grouts for the encapsulation of solid items has also been investigated during 1981. (U.K.)

  14. Characterization of cement-stabilized Cd wastes

    International Nuclear Information System (INIS)

    Maria Diez, J.; Madrid, J.; Macias, A.

    1996-01-01

    Portland cement affords both physical and chemical immobilization of cadmium. The immobilization has been studied analyzing the pore fluid of cement samples and characterizing the solid pastes by X-ray diffraction. The influence of cadmium on the cement hydration and on its mechanical properties has been also studied by isothermal conduction calorimetry and by the measure of strength and setting development. Finally, the effect of cement carbonation on the immobilization of cadmium has been analyzed

  15. Substantial global carbon uptake by cement carbonation

    OpenAIRE

    Xi, Fengming; Davis, Steven J.; Ciais, Philippe; Crawford-Brown, Douglas; Guan, Dabo; Pade, Claus; Shi, Tiemao; Syddall, Mark; Lv, Jie; Ji, Lanzhu; Bing, Longfei; Wang, Jiaoyue; Wei, Wei; Yang, Keun-Hyeok; Lagerblad, Björn

    2016-01-01

    Calcination of carbonate rocks during the manufacture of cement produced 5% of global CO2 emissions from all industrial process and fossil-fuel combustion in 20131, 2. Considerable attention has been paid to quantifying these industrial process emissions from cement production2, 3, but the natural reversal of the process—carbonation—has received little attention in carbon cycle studies. Here, we use new and existing data on cement materials during cement service life, demolition, and secondar...

  16. Cementation unit for radioactive wastes

    International Nuclear Information System (INIS)

    Dellamano, Jose Claudio; Vicente, Roberto; Lima, Jose Rodrigues de

    2001-01-01

    This communication describes the waste cementation process and facility developed at Instituto de Pesquisas Energeticas e Nucleares - IPEN. The process is based on 200 litres batch operation, in drum mixing, with continuous cement feeding. The equipment is a single recoverable helicoidal mixer and a turning table that allows the drum to rotate during the mixing operation, simulating a planetary mixer. The facility was designed to treat contact handled liquids and wet solid wastes, but can be adapted for shielded equipment and remote operation. (author)

  17. Radioactivity concentrations in common brands of cement in Nigeria

    International Nuclear Information System (INIS)

    Farai, I.P.; Ejeh, J.E.

    2006-01-01

    Radioactivity concentrations of 238 U, 232 Th and 40 K in common brands of Portland cement in Nigeria have been measured using a shielded 7.6 cm x 7.6 cm NaI(Tl) detector coupled to a Canberra series 10 plus multichannel analyzer. The cement samples show significant spread in their radioactivity concentrations, even among samples of the same brand. The weighted means of the activity concentrations of 238 U, 232 Th and 40 K in the different brands were 52.4, 4.1 and 91.8 Bq/kg, respectively. The radium equivalent ranged between 29.1 and 128.1 Bq/kg with a weighted mean value of 68.5 Bq/kg. The values are lower than corresponding values in cement samples in most other countries as contained in recent publications. They are also lower than the UNSCEAR recommended maximum of 370 Bq/kg. The safety criteria developed by ITB Poland for radioactivity in building materials, especially for radon build-up in homes were however, exceeded in some of the cement samples. (authors)

  18. 21 CFR 872.3275 - Dental cement.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Dental cement. 872.3275 Section 872.3275 Food and... DENTAL DEVICES Prosthetic Devices § 872.3275 Dental cement. (a) Zinc oxide-eugenol—(1) Identification... filling or as a base cement to affix a temporary tooth filling, to affix dental devices such as crowns or...

  19. Cement production from coal conversion residues

    International Nuclear Information System (INIS)

    Brown, L.D.; Clavenna, L.R.; Eakman, J.M.; Nahas, N.C.

    1981-01-01

    Cement is produced by feeding residue solids containing carbonaceous material and ash constituents obtained from converting a carbonaceous feed material into liquids and/or gases into a cement-making zone and burning the carbon in the residue solids to supply at least a portion of the energy required to convert the solids into cement

  20. Multicomponent modelling of Portland cement hydration reactions

    NARCIS (Netherlands)

    Ukrainczyk, N.; Koenders, E.A.B.; Van Breugel, K.

    2012-01-01

    The prospect of cement and concrete technologies depends on more in depth understanding of cement hydration reactions. Hydration reaction models simulate the development of the microstructures that can finally be used to estimate the cement based material properties that influence performance and

  1. Electrically conductive Portland cement concrete.

    Science.gov (United States)

    1986-01-01

    There is a need for an effective, simple-to-install secondary anode system for use in the cathodic protection of reinforced concrete bridge decks. In pursuit of such a system, carbon fibers and carbon black were incorporated in portland cement concre...

  2. Polymer reinforcement of cement systems

    International Nuclear Information System (INIS)

    Swamy, R.N.

    1979-01-01

    In the last couple of decades several cement- and concrete-based composites have come into prominence. Of these, cement-polymer composites, like cement-fibre composites, have been recognised as very promising, and considerable research and development on their properties, fabrication methods and application are in progress. Of the three types of concrete materials which incorporate polymers to form composites, polymer impregnated concrete forms a major development in which hardened concrete is impregnated with a liquid monomer which is subsequently polymerized to form a rigid polymer network in the pores of the parent material. In this first part of the extensive review of the polymer reinforcement of cement systems, the process technology of the various monomer impregnation techniques and the properties of the impregnated composite are assessed critically. It is shown that the high durability and superior performance of polymer impregnated concrete can provide an economic and competitive alternative in in situ strengthening, and in other areas where conventional concrete can only at best provide adequate performance. The review includes a section on radiation-induced polymerization. (author)

  3. Westerns fra hele verden

    DEFF Research Database (Denmark)

    Bjerre, Thomas Ærvold

    2014-01-01

    Om den amerikanske western, spaghettiwesterns, kommunistiske westerns og danske westerns - i forbindelse med Kristian Levrings The Salvation (2014).......Om den amerikanske western, spaghettiwesterns, kommunistiske westerns og danske westerns - i forbindelse med Kristian Levrings The Salvation (2014)....

  4. Assessment of natural radioactivity levels and radiation hazards due to cement industry

    International Nuclear Information System (INIS)

    El-Taher, A.; Abdel Halim, A.S.

    2010-01-01

    The cement industry is considered as one of the basic industries that plays an important role in the national economy of developing countries. Activity concentrations of 226 Ra, 232 Th and 40 K in Assiut cement and other local cement types from different Egyptian factories has been measured by using γ-ray spectrometry. From the measured γ-ray spectra, specific activities were determined. The measured activity concentrations for these natural radionuclides were compared with the reported data for other countries. The average values obtained for 226 Ra, 232 Th and 40 K activity concentration in different types of cement are lower than the corresponding global values reported in UNSCEAR publications. The obtained results show that the averages of radiation hazard parameters for Assiut cement factory are lower than the acceptable level of 370 Bq kg -1 for radium equivalent Ra eq , 1 for level index Iγr, the external hazard index Hex ≤1 and 59 (nGy h -1 ) for absorbed dose rate. The manufacturing operation reduces the radiation hazard parameters. Cement does not pose a significant radiological hazard when used for construction of buildings.

  5. [Cement augmentation on the spine : Biomechanical considerations].

    Science.gov (United States)

    Kolb, J P; Weiser, L; Kueny, R A; Huber, G; Rueger, J M; Lehmann, W

    2015-09-01

    Vertebral compression fractures are the most common osteoporotic fractures. Since the introduction of vertebroplasty and screw augmentation, the management of osteoporotic fractures has changed significantly. The biomechanical characteristics of the risk of adjacent fractures and novel treatment modalities for osteoporotic vertebral fractures, including pure cement augmentation by vertebroplasty, and cement augmentation of screws for posterior instrumentation, are explored. Eighteen human osteoporotic lumbar spines (L1-5) adjacent to vertebral bodies after vertebroplasty were tested in a servo-hydraulic machine. As augmentation compounds we used standard cement and a modified low-strength cement. Different anchoring pedicle screws were tested with and without cement augmentation in another cohort of human specimens with a simple pull-out test and a fatigue test that better reflects physiological conditions. Cement augmentation in the osteoporotic spine leads to greater biomechanical stability. However, change in vertebral stiffness resulted in alterations with the risk of adjacent fractures. By using a less firm cement compound, the risk of adjacent fractures is significantly reduced. Both screw augmentation techniques resulted in a significant increase in the withdrawal force compared with the group without cement. Augmentation using perforated screws showed the highest stability in the fatigue test. The augmentation of cement leads to a significant change in the biomechanical properties. Differences in the stability of adjacent vertebral bodies increase the risk of adjacent fractures, which could be mitigated by a modified cement compound with reduced strength. Screws that were specifically designed for cement application displayed greatest stability in the fatigue test.

  6. Sustainability of cement kiln co-processing of wastes in India: a pilot study.

    Science.gov (United States)

    Baidya, Rahul; Ghosh, Sadhan Kumar; Parlikar, Ulhas V

    2017-07-01

    Co-processing in cement kiln achieves effective utilization of the material and energy value present in the wastes, thereby conserving the natural resources by reducing the use of virgin material. In India, a number of multifolded initiatives have been taken that take into account the potential and volume of waste generation. This paper studies the factors which might influence the sustainability of co-processing of waste in cement kilns as a business model, considering the issues and challenges in the supply chain framework in India in view of the four canonical pillars of sustainability. A pilot study on co-processing was carried out in one of the cement plant in India to evaluate the environmental performance, economical performance, operational performance and social performance. The findings will help India and other developing countries to introduce effective supply chain management for co-processing while addressing the issues and challenges during co-processing of different waste streams in the cement kilns.

  7. Cement solidification of spent ion exchange resins produced by the nuclear industry

    International Nuclear Information System (INIS)

    Jaouen, C.; Vigreux, B.

    1988-01-01

    Cement solidification technology has been applied to spent ion exchange resins for many years in countries throughout the world (at reactors, research centers and spent fuel reprocessing plants). Changing specifications for storage of radioactive waste have, however, confronted the operators of such facilities with a number of problems. Problems related both to the cement solidification process (water/cement/resin interactions and chemical interactions) and to its utilization (mixing, process control, variable feed composition, etc.) have often led waste producers to prefer other, polymer-based processes, which are very expensive and virtually incompatible with water. This paper discusses research on cement solidification of ion exchange resins since 1983 and the development of application technologies adapted to nuclear service conditions and stringent finished product quality requirements

  8. Physical and mechanical properties of cement mortar made with brick waste

    Directory of Open Access Journals (Sweden)

    Mohamed Guendouz

    2018-01-01

    Full Text Available The development of new building materials is a current problem where researchers are trying to find the right materials for each region and returning cheapest countries. Recycling and recovery of waste are now considered as a promising solution to meet the deficit between production and consumption and protecting the environment. This work focused on the study of the effect of brick waste in the production of cement mortar with substitution rates ranging from 5-30% by weight of cement and to compare its performance with fresh and hardened state with ordinary mortar considered as control mortar. Compressive and tensile strengths up to 28 days of age were compared with those of controlled mortar. Water absorption was also measured at 28 days of age. The test results indicate the beneficial effect of brick waste powder on performance of cement mortar with an optimum of 15% of cement weight substitution.

  9. CO2 Capture by Cement Raw Meal

    DEFF Research Database (Denmark)

    Pathi, Sharat Kumar; Lin, Weigang; Illerup, Jytte Boll

    2013-01-01

    The cement industry is one of the major sources of CO2 emissions and is likely to contribute to further increases in the near future. The carbonate looping process has the potential to capture CO2 emissions from the cement industry, in which raw meal for cement production could be used...... as the sorbent. Cyclic experiments were carried out in a TGA apparatus using industrial cement raw meal and synthetic raw meal as sorbents, with limestone as the reference. The results show that the CO2 capture capacities of the cement raw meal and the synthetic raw meal are comparable to those of pure limestone...... that raw meal could be used as a sorbent for the easy integration of the carbonate looping process into the cement pyro process for reducing CO2 emissions from the cement production process....

  10. Leaching of tritium from a cement composite

    International Nuclear Information System (INIS)

    Matsuzuru, Hideo; Ito, Akihiko

    1978-10-01

    Leaching of tritium from cement composites into an aqueous phase has been studied to evaluate the safety of incorporation of the tritiated liquid waste into cement. Leaching tests were performed by the method recommended by the International Atomic Energy Agency. The Leaching fraction was measured as functions of waste-cement ratio (Wa/C), temperature of leachant and curing time. The tritium leachability of cement in the long term test follows the order: alumina cement portland cement slag cement. The fraction of tritium leached increases with increasing Wa/C and temperature and decreasing curing period. A deionized water as a leachant gives a slightly higher leachability than synthetic sea water. The amount leached of tritium from a 200 l drum size specimen was estimated on the basis of the above results. (author)

  11. Through BHA (Bottom Hole Assembly) cementing with proprietary cementing technology

    Energy Technology Data Exchange (ETDEWEB)

    Fanguy, Charles ' Joey' ; Mueller, Dan T. [BJ Services Company, Houston, TX (United States); Garrett, J.C. [Palm Energy Partners, LLC, Metairie, LA (United States)

    2004-07-01

    There are many problems that can arise when drilling into sub-normally pressured or naturally fractured zones. Lost circulation is one problem that is commonly encountered while drilling oil and gas wells. Lost circulation can lead to increased costs associated with drilling due to rig time, spreadsheet costs, and expensive mud system losses. Cement is one of the most effective treatment options, although it is not normally considered the first option because most operators are forced to trip out of the wellbore and utilize a squeeze packer. This is not always a viable option because of potential well control issues associated with the hydrostatic pressure reduction due to the losses of the whole mud. One treatment option that is commonly overlooked is pumping cement slurries through the bottom hole assembly and drill bit. This is generally not attempted for a variety of reasons. These reasons include: I Concern about 'squeezing off' of the cement in the bit II Lack of potential quality control associated with mixing 'on the fly' III Lack of the ability to test the actual mixed slurry samples The use of a pre-mixed, storable cement slurry has eliminated the concerns associated with pumping cement slurries through mud motors, MWD tools, BHA's, and drill bits. This advanced cement technology has been successfully utilized while reducing the risks associated with these lost circulation treatments. In addition, this technology has eliminated the costs associated with using a squeeze packer and the rig time required for several trips out of the wellbore. The paper will describe the premixed slurry properties and QA/QC procedures that are required for successful through the bit operations. This paper will also provide case histories of successful through the bit operation, as well as background information leading to the treatments. The case histories include successful through the bit remediation of severe lost circulation zones and as well the

  12. Analysis of cement-treated clay behavior by micromechanical approach

    OpenAIRE

    Zhang , Dong-Mei; Yin , Zhenyu; Hicher , Pierre Yves; Huang , Hong-Wei

    2013-01-01

    International audience; Experimental results show the significant influence of cement content on the mechanical properties of cement-treated clays. Cementation is produced by mixing a certain amount of cement with the saturated clay. The purpose of this paper is to model the cementation effect on the mechanical behavior of cement-treated clay. A micromechanical stress-strain model is developed considering explicitly the cementation at inter-cluster contacts. The inter-cluster bonding and debo...

  13. THE USE OF SISAL FIBRE AS REINFORCEMENT IN CEMENT BASED COMPOSITES

    Directory of Open Access Journals (Sweden)

    Romildo Dias Tolêdo Filho

    1999-08-01

    Full Text Available ABSTRACT The inclusion of fibre reinforcement in concrete, mortar and cement paste can enhance many of the engineering properties of the basic materials, such as fracture toughness, flexural strength and resistance to fatigue, impact, thermal shock and spalling. In recent years, a great deal of interest has been created worldwide on the potential applications of natural fibre reinforced, cement based composites. Investigations have been carried out in many countries on various mechanical properties, physical performance and durability of cement based matrices reinforced with naturally occurring fibres including sisal, coconut, jute, bamboo and wood fibres. These fibres have always been considered promising as reinforcement of cement based matrices because of their availability, low cost and low consumption of energy. In this review, the general properties of the composites are described in relation to fibre content, length, strength and stiffness. A chronological development of sisal fibre reinforced, cement based matrices is reported and experimental data are provided to illustrate the performance of sisal fibre reinforced cement composites. A brief description on the use of these composite materials as building products has been included. The influence of sisal fibres on the development of plastic shrinkage in the pre-hardened state, on tensile, compressive and bending strength in the hardened state of mortar mixes is discussed. Creep and drying shrinkage of the composites and the durability of natural fibres in cement based matrices are of particular interest and are also highlighted. The results show that the composites reinforced with sisal fibres are reliable materials to be used in practice for the production of structural elements to be used in rural and civil construction. This material could be a substitute asbestos-cement composite, which is a serious hazard to human and animal health and is prohibited in industrialized countries. The

  14. Synthesis of Portland cement and calcium sulfoaluminate-belite cement for sustainable development and performance

    Science.gov (United States)

    Chen, Irvin Allen

    Portland cement concrete, the most widely used manufactured material in the world, is made primarily from water, mineral aggregates, and portland cement. The production of portland cement is energy intensive, accounting for 2% of primary energy consumption and 5% of industrial energy consumption globally. Moreover, portland cement manufacturing contributes significantly to greenhouse gases and accounts for 5% of the global CO2 emissions resulting from human activity. The primary objective of this research was to explore methods of reducing the environmental impact of cement production while maintaining or improving current performance standards. Two approaches were taken, (1) incorporation of waste materials in portland cement synthesis, and (2) optimization of an alternative environmental friendly binder, calcium sulfoaluminate-belite cement. These approaches can lead to less energy consumption, less emission of CO2, and more reuse of industrial waste materials for cement manufacturing. In the portland cement part of the research, portland cement clinkers conforming to the compositional specifications in ASTM C 150 for Type I cement were successfully synthesized from reagent-grade chemicals with 0% to 40% fly ash and 0% to 60% slag incorporation (with 10% intervals), 72.5% limestone with 27.5% fly ash, and 65% limestone with 35% slag. The synthesized portland cements had similar early-age hydration behavior to commercial portland cement. However, waste materials significantly affected cement phase formation. The C3S--C2S ratio decreased with increasing amounts of waste materials incorporated. These differences could have implications on proportioning of raw materials for cement production when using waste materials. In the calcium sulfoaluminate-belite cement part of the research, three calcium sulfoaluminate-belite cement clinkers with a range of phase compositions were successfully synthesized from reagent-grade chemicals. The synthesized calcium sulfoaluminate

  15. The cement recycling of the earthquake disaster debris by Hachinohe Cement Co., Ltd

    International Nuclear Information System (INIS)

    Kataoka, Masayuki

    2015-01-01

    A tremendous quantity of earthquake disaster debris and tsunami sediment was resulted by the Great East Japan Earthquake on March 11, 2011. Hachinohe Cement Co., Ltd., a Sumitomo Osaka Cement subsidiary, was the first cement industry company to receive and process such waste materials outside of their usual prefecture area, while the company is performing their treatment and recycling services locally in Hachinohe City and Aomori Prefecture. This report provides an explanation about the recycling mechanism of waste materials and by-products in cement manufacturing process, and introduces an example of actual achievements for the disaster debris treatment by utilizing the cement recycling technologies at the Hachinohe Cement Plant. (author)

  16. Determination of quality standard of cemented radioactive wastes

    International Nuclear Information System (INIS)

    Johan, B.

    1997-01-01

    The standard determination of cemented low activity radioactive waste has been carried out. This study was intended to find the quality of immobilized product as a guaranty to the public and the environmental safety. As preliminary study, there parameters type have been studied i.e, the density, compressive strength and the leaching rate. By adopted the formulations of advanced country and field data, it can be concluded that the cementation waste should have the density, p, between 1.70 and 2.50 g.cm - 3, the compressive strength, S, between 20 and 50 N.mm - 2, the leaching rates R n between 1.70 x 10 - 2 and 2.50 x 10 - 3 g.cm - 2.day - 1 and after 150 days leaching time the leaching rate R n - 3 g.cm - 2.day - 1. This study is expected to be used to propose the Indonesian National Standard (INS) (author)

  17. Primary cemented total hip arthroplasty: 10 years follow-up

    Directory of Open Access Journals (Sweden)

    Nath Rajendra

    2010-01-01

    Full Text Available Background: Primary cemented total hip arthroplasty is a procedure for non-traumatic and traumatic affections of the hip. Long term follow-up is required to assess the longevity of the implant and establish the procedure. Indo-Asian literature on long term result of total hip arthroplasty is sparse. We present a 10-year follow-up of our patients of primary cemented total hip arthroplasty. Materials and Methods: We operated 31 hips in 30 patients with primary cemented total hip arthroplasty. We followed the cases for a minimum period of 10 years with a mean follow-up period of 12.7 years. The mean age of the patients was 60.7 years (range 37-82 yrs male to female ratio was 2:1. The clinical diagnoses included - avascular necrosis of femoral head (n=15, sero positive rheumatoid arthritis (n=5, seronegative spondylo-arthropathy (n=4, neglected femoral neck fractures (n=3, healed tubercular arthritis (n=2 and post traumatic osteoarthritis of hip (n=2. The prostheses used were cemented Charnley′s total hip (n=12 and cemented modular prosthesis (n=19. The results were assessed according to Harris hip score and radiographs taken at yearly intervals. Results: The mean follow-up is 12.7 yrs (range 11-16 yrs Results in all operated patients showed marked improvement in Harris hip score from preoperative mean 29.2 to 79.9 at 10 years or more followup. However, the non-inflammatory group showed more sustained long term improvement as compared to the inflammatory group, as revealed by the Harris hip score. Mean blood loss was 450ml (±3.7 ml, mean transfusion rate was 1.2 units (±.3. The complications were hypotension (n=7, shortening> 1.5 cm (n=9, superficial infection (n=2 and malposition of prosthesis (n=1. Conclusion: The needs of Indian Asian patients, vary from what is discussed in literature. The pain tolerance is greater than western population and financial constraints are high. Thus revision surgery among Indian-Asian patients is less compared

  18. Use sulfoferritic cements in construction

    Science.gov (United States)

    Samchenko, Svetlana V.; Zorin, Dmitriy A.

    2018-03-01

    Currently, high-rise construction has received increasing attention around the world. In the big cities under construction is less space and one solution is the high-rise construction. However, high-rise buildings use special requirements, such as strength, thermal insulation, wind load and others. When concrete is exposed to continuous loads by wind or to mechanical loads, it undergoes abrasion. Resistance to this process depends on the characteristics of materials that the concrete and finishing seams are made of. Research on increasing impact and abrasion resistance of calcium sulfoferrite-based cement stone from the perspective of formation of cement stone structure will be instrumental in developing durable materials for application in high-rise construction.

  19. Concrete research using blended cements

    International Nuclear Information System (INIS)

    Butler, W.B.

    2001-01-01

    Concrete research increasingly involves the use of mixes containing one or more of the supplementary cementitious materials (SCMs), often in conjunction with chemical admixtures. The influence of materials is commonly evaluated on the basis of water/ cement or water/ binder ratio and SCM content as a percentage of total binder, with dosage level of chemical admixture varied to maintain workability. As a result, more than one variable is introduced at a time and the objectives of the research may not be achieved. The significance of water/ cement ratio and addition rates of admixtures are examined from a practical standpoint with suggestions for more appropriate means of evaluation of the influence of individual materials. Copyright (2001) The Australian Ceramic Society

  20. The density of cement phases

    International Nuclear Information System (INIS)

    Balonis, M.; Glasser, F.P.

    2009-01-01

    The densities of principal crystalline phases occurring in Portland cement are critically assessed and tabulated, in some cases with addition of new data. A reliable and self-consistent density set for crystalline phases was obtained by calculating densities from crystallographic data and unit cell contents. Independent laboratory work was undertaken to synthesize major AFm and AFt cement phases, determine their unit cell parameters and compare the results with those recorded in the literature. Parameters were refined from powder diffraction patterns using CELREF 2 software. A density value is presented for each phase, showing literature sources, in some cases describing limitations on the data, and the weighting attached to numerical values where an averaging process was used for accepted data. A brief discussion is made of the consequences of the packing of water to density changes in AFm and AFt structures.

  1. Glass ionomer cement: literature review

    OpenAIRE

    Sérgio Spezzia

    2017-01-01

    Introduction: In the dental area preventive actions occur in an attempt to avoid the installation of caries, a disease that has an increased prevalence in the population and which is a Public Health problem. Some resources are used for such, such as: performing early diagnosis and the option for conservative treatments of minimal intervention. The glass ionomer cement (CIV), coming from its beneficial characteristics that meet current trends, is closely related to the precepts of Preventive a...

  2. Modernization of Byuzmeyinsky Cement Plant

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-03-01

    With an objective of saving energy and reducing greenhouse gas emission, investigations and discussions were given on a modernization project for Byuzmeyinsky Cement Factory, the only cement factory in Turkmenistan. Byuzmeyinsky Cement Factory uses the wet process which consumes a large amount of energy, is inferior in production efficiency and quality, and discharging a great amount of greenhouse effect gas. The present project will execute change of the raw material crusher into a vertical roll mill for one of the four wet kilns, and change of the facilities for raw material powder mixing and storing and clinker manufacturing into dry-type facilities using the NSP system. As a result of the discussions, the energy saving effect would be 86,321 tons of crude oil equivalent annually, and the greenhouse gas emission reducing effect would be 224,467 t-CO2 annually. The total fund amount required for the project is estimated to be 90,211,000 dollars. With regard to the profitability, the internal financial profit rate would be 9.71% after tax, and the ROE would be 18.62%, whereas the project is considered feasible. (NEDO)

  3. A Twofold Comparison between Dual Cure Resin Modified Cement and Glass Ionomer Cement for Orthodontic Band Cementation.

    Science.gov (United States)

    Attar, Hanaa El; Elhiny, Omnia; Salem, Ghada; Abdelrahman, Ahmed; Attia, Mazen

    2016-12-15

    To test the solubility of dual cure resin modified resin cement in a food simulating solution and the shear bond strength compared to conventional Glass ionomer cement. The materials tested were self-adhesive dual cure resin modified cement and Glass Ionomer (GIC). Twenty Teflon moulds were divided into two groups of tens. The first group was injected and packed with the modified resin cement, the second group was packed with GIC. To test the solubility, each mould was weighed before and after being placed in an analytical reagent for 30 days. The solubility was measured as the difference between the initial and final drying mass. To measure the Shear bond strength, 20 freshly extracted wisdom teeth were equally divided into two groups and embedded in self-cure acrylic resin. Four mm sections of stainless steel bands were cemented to the exposed buccal surfaces of teeth under a constant load of 500 g. Shear bond strength was measured using a computer controlled materials testing machine and the load required to deband the samples was recorded in Newtons. GIC showed significantly higher mean weight loss and an insignificant lower Shear bond strength, compared to dual cure resin Cement. It was found that dual cure resin modified cement was less soluble than glass ionomer cement and of comparable bond strength rendering it more useful clinically for orthodontic band cementation.

  4. Globalisation and western music historiography

    Directory of Open Access Journals (Sweden)

    Romanou Katy

    2015-01-01

    Full Text Available Globalisation of musicology and music history aims to fuse the divisions created during Western music’s acme, and is referred to as “post-European historical thinking”. Therefore, “post” and “pre” European historical thinking have much in common. One aspect of this process of fragmentation was that music history was separated from theory and that Western Music Histories succeeded General Music Histories (a development described in some detail in the article. Connecting global music history with “post-European” historical thinking is one among numerous indications of Western awareness that European culture has reached some sort of a terminal phase. Concurrently, countries that have been developing by following Western Europe as a prototype, are leading today some past phase of Western development, which, with the ideas of cultural relativism prevailing, are not considered inferior.

  5. Use of Incineration Solid Waste Bottom Ash as Cement Mixture in Cement Production

    Science.gov (United States)

    Jun, N. H.; Abdullah, M. M. A. B.; Jin, T. S.; Kadir, A. A.; Tugui, C. A.; Sandu, A. V.

    2017-06-01

    Incineration solid waste bottom ash was use to examine the suitability as a substitution in cement production. This study enveloped an innovative technology option for designing new equivalent cement that contains incineration solid waste bottom ash. The compressive strength of the samples was determined at 7, 14, 28 and 90 days. The result was compared to control cement with cement mixture containing incineration waste bottom ash where the result proved that bottom ash cement mixture able achieve its equivalent performance compared to control cement which meeting the requirement of the standards according to EN 196-1. The pozzolanic activity index of bottom ash cement mixture reached 0.92 at 28 days and 0.95 at 90 and this values can be concluded as a pozzolanic material with positive pozzolanic activity. Calcium hydroxide in Portland cement decreasing with the increasing replacement of bottom ash where the reaction occur between Ca(OH)2 and active SiO2.

  6. Natural cement as the precursor of Portland cement: Methodology for its identification

    International Nuclear Information System (INIS)

    Varas, M.J.; Alvarez de Buergo, M.; Fort, R.

    2005-01-01

    When cements appeared in the 19th century, they took the place of traditional binding materials (lime, gypsum, and hydraulic lime) which had been used until that time. Early cements can be divided into two groups, natural and artificial (Portland) cements. Natural cements were introduced first, but their widespread usage was short-lived as they were quickly replaced by artificial cements (Portland), still the most important and predominant today. The main differences between natural and artificial cements arise during the manufacturing process. The final properties of the cements are greatly influenced by differences in the raw materials and burning temperatures employed. The aim of this paper is to assess the efficiency of traditional analytical techniques (petrographic microscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy (FTIR)) used to differentiate natural and artificial cements

  7. Effects of cement particle size distribution on performance properties of Portland cement-based materials

    Energy Technology Data Exchange (ETDEWEB)

    Bentz, D.P.; Garboczi, E.J.; Haecker, C.J.; Jensen, O.M.

    1999-10-01

    The original size, spatial distribution, and composition of Portland cement particles have a large influence on hydration kinetics, microstructure development, and ultimate properties of cement-based materials. In this paper, the effects of cement particle size distribution on a variety of performance properties are explored via computer simulation and a few experimental studies. Properties examined include setting time, heat release, capillary porosity percolation, diffusivity, chemical shrinkage, autogenous shrinkage, internal relative humidity evolution, and interfacial transition zone microstructure. The effects of flocculation and dispersion of the cement particles in the starting microstructures on resultant properties are also briefly evaluated. The computer simulations are conducted using two cement particle size distributions that bound those commonly in use today and three different water-to-cement ratios: 0.5, 0.3, and 0.246. For lower water-to-cement ratio systems, the use of coarser cements may offer equivalent or superior performance, as well as reducing production costs for the manufacturer.

  8. The cement solidification systems at LANL

    International Nuclear Information System (INIS)

    Veazey, G.W.

    1990-01-01

    There are two major cement solidification systems at Los Alamos National Laboratory. Both are focused primarily around treating waste from the evaporator at TA-55, the Plutonium Processing Facility. The evaporator receives the liquid waste stream from TA-55's nitric acid-based, aqueous-processing operations and concentrates the majority of the radionuclides in the evaporator bottoms solution. This is sent to the TA-55 cementation system. The evaporator distillate is sent to the TA-50 facility, where the radionuclides are precipitated and then cemented. Both systems treat TRU-level waste, and so are operated according to the criteria for WIPP-destined waste, but they differ in both cement type and mixing method. The TA-55 systems uses Envirostone, a gypsum-based cement and in-drum prop mixing; the TA-50 systems uses Portland cement and drum tumbling for mixing

  9. Characterization of experimental cements with endodontic goal

    International Nuclear Information System (INIS)

    Dantas, A.M.X.; Sousa, W.J.B.; Oliveira, E.D.C.; Carrodeguas, R.G.; Fook, M.V. Lia; Universidade Estadual da Paraiba

    2017-01-01

    The present study aimed to characterize experimental endodontic cements using as comparative parameter MTA cement. Two experimental endodontic cements were assessed: one based on 95% tri-strontium aluminate and 5% gypsum (CE1) and another based on 50% Sr_3Al_2O_6 and 50% non-structural white cement (CE2). Experimental cements were manipulated and characterized by scanning electron microscopy (SEM), coupled to EDS mode, X-ray diffractometer (XRD) and Thermogravimetric (TG) analysis. Data analysis demonstrated that the particles of the materials used presented varied shapes and sizes, with similar elements and crystalline behavior. However, CE1 presented increased mass loss. Experimental cements presents similarities to MTA, nevertheless, further studies are encourage to determinate comparative properties with the commercially material. (author)

  10. Modelling porewater chemistry in hydrated Portland cement

    International Nuclear Information System (INIS)

    Berner, U.R.

    1987-01-01

    Extensive employment of concrete is foreseen in radioactive waste repositories. A prerequisite for modelling the interactions between concrete and formation waters is characterization of the concrete system. Available experimental data from high pressure squeezing of cement pore-water indicate that, besides the high pH due to alkali hydroxide dissolution, cement composition itself influences the solubility determining solid phases. A model which simulates the hydration of Portland cement assuming complete hydration of the main clinker minerals is presented. The model also includes parameters describing the reactions between the cement and blending agents. Comparison with measured pore-water data generally gives a consistent picture and, as expected, the model gives correct predictions for pure Portland cements. For blended cements, the required additional parameters can, to some extent, be derived from pore-water analysis. 14 references, 1 figure, 4 tables

  11. Chemistry of cements for nuclear applications

    International Nuclear Information System (INIS)

    Barrett, P.; Glasser, F.P.

    1992-01-01

    In recent times the nuclear industry has thrown up challenges which cannot be met by the application of conventional civil and materials engineering knowledge. The contributions in this volume investigate all aspects of cement performance. The scope of the papers demonstrates the current balance of activities which have as their objective the elucidation of kinetics and immobilization, determining material interactions and of assessing future performance. The papers reflect the varied goals of the sponsors who include national governments, the Commission of the European Communities and the nuclear industries. In six parts attention is paid to the durability of cement and concrete in repository environment; interactions between cement, waste components and ground water; properties and performance of cement materials; leach behavior and mechanisms, diffusional properties of cement and concrete, including porosity-permeability relationships; and thermodynamics of cementitious systems and modelling of cement performance

  12. The mechanical effect of the existing cement mantle on the in-cement femoral revision.

    Science.gov (United States)

    Keeling, Parnell; Lennon, Alexander B; Kenny, Patrick J; O'Reilly, Peter; Prendergast, Patrick J

    2012-08-01

    Cement-in-cement revision hip arthroplasty is an increasingly popular technique to replace a loose femoral stem which retains much of the original cement mantle. However, some concern exists regarding the retention of the existing fatigued and aged cement in such cement-in-cement revisions. This study investigates whether leaving an existing fatigued and aged cement mantle degrades the mechanical performance of a cement-in-cement revision construct. Primary cement mantles were formed by cementing a polished stem into sections of tubular steel. If in the test group, the mantle underwent conditioning in saline to simulate ageing and was subject to a fatigue of 1 million cycles. If in the control group no such conditioning or fatigue was carried out. The cement-in-cement procedure was then undertaken. Both groups underwent a fatigue of 1 million cycles subsequent to the revision procedure. Application of a Mann-Whitney test on the recorded subsidence (means: 0.51, 0.46, n=10+10, P=0.496) and inducible displacement (means: 0.38, 0.36, P=0.96) revealed that there was no statistical difference between the groups. This study represents further biomechanical investigation of the mechanical behaviour of cement-in-cement revision constructs. Results suggest that pre-revision fatigue and ageing of the cement may not be deleterious to the mechanical performance of the revision construct. Thus, this study provides biomechanical evidence to back-up recent successes with this useful revision technique. Copyright © 2012 Elsevier Ltd. All rights reserved.

  13. Sustainable Development of the Cement Industry and Blended Cements to Meet Ecological Challenges

    OpenAIRE

    Sobolev, Konstantin

    2003-01-01

    The world production of cement has greatly increased in the past 10 years. This trend is the most significant factor affecting technological development and the updating of manufacturing facilities in the cement industry. Existing technology for the production of cement clinker is ecologically damaging; it consumes much energy and natural resources and also emits pollutants. A new approach to the production of blended or high-volume mineral additive (HVMA) cement helps to improve its ecologi...

  14. Pulmonary Cement Embolism following Percutaneous Vertebroplasty

    Directory of Open Access Journals (Sweden)

    Ümran Toru

    2014-01-01

    Full Text Available Percutaneous vertebroplasty is a minimal invasive procedure that is applied for the treatment of osteoporotic vertebral fractures. During vertebroplasty, the leakage of bone cement outside the vertebral body leads to pulmonary cement embolism, which is a serious complication of this procedure. Here we report a 48-year-old man who was admitted to our hospital with dyspnea after percutaneous vertebroplasty and diagnosed as pulmonary cement embolism.

  15. Incorporation of bitumen and calcium silicate in cement and lime stabilized soil blocks

    Science.gov (United States)

    Kwan, W. H.; Cheah, C. B.; Ramli, M.; Al-Sakkaf, Y. K.

    2017-04-01

    Providing affordable housing is the most critical problem in many of the developing countries. Using earth materials in building construction is one of the feasible methods to address this issue and it can be a way towards sustainable construction as well. However, the published information on the stabilized soil blocks is limited. Therefore, the present study is conducted to examine the characterization of the soils and engineering properties of the stabilized soil blocks. Four types of stabilizer were used in the study, namely; cement, slaked lime, bitumen emulsion and calcium silicate. Cement and slaked lime were added at different percentages in the range of 5% to 15%, with interval of 2.5%. The percentage was determined based on weight of soil. Meanwhile, bitumen emulsion and calcium silicate were incorporated at various percentages together with 10% of cement. Dosage of bitumen emulsion is in the range of 2% to 10% at interval of 2% while calcium silicate was incorporated at 0.50%, 0.75%, 1.00%, 1.25%, 1.50% and 2.00%. Results show that cement is the most viable stabilizer for the soil block among all stabilizers in this study. The bulk density, optimum moisture content and compressive strengths were increased with the increasing cement content. The most suitable cement content was 10% added at moisture content of 12%. Lime, bitumen and calcium contents were recommended at 5.0%, 6.0% and 1.25%, respectively.

  16. Tritium sorption by cement and subsequent release

    International Nuclear Information System (INIS)

    Ono, F.; Tanaka, S.; Yamawaki, M.

    1994-01-01

    In a fusion reactor or tritium handling facilities, contamination of concrete by tritium and subsequent release from it to the reactor or experimental rooms is a matter of problem for safety control of tritium and management of operational environment. In order to evaluate these tritium behavior, interaction of tritiated water with concrete or cement should be clarified. In the present study, HTO sorption and subsequent release from cement were studied by combining various experimental methods. From the basic studies on tritium-cement interactions, it has become possible to evaluate tritium uptake by cement or concrete and subsequent tritium release behavior as well as tritium removing methods from them

  17. Immobilisation of ion exchange resins in cement

    International Nuclear Information System (INIS)

    Howard, C.G.; Jolliffe, C.B.; Lee, D.J.

    1990-09-01

    The removal of activity from spent decontaminating solutions eg LOMI can be achieved using organic ion exchange resins. These resins can be successfully immobilised in cement based matrices. The optimum cement system contained 10% ordinary Portland cement 84% gg blast furnace slag, 6% microsilica with a water cement ratio of 0.5 and a dry resin loading of 36% with respect to total weight. This formulation was successfully scaled up to 200 litres giving a product with acceptable compressive strength, dimensional stability and elastic modulus. Storage of samples under water appears to have no detrimental effects on the product's properties. (author)

  18. Immobilisation of ion exchange resins in cement

    International Nuclear Information System (INIS)

    Howard, C.G.; Jolliffe, C.B.; Lee, D.J.

    1990-09-01

    The removal of activity from spent decontaminating solutions eg LOMI can be achieved using organic ion exchange resins. These resins can be successfully immobilised in cement based matrices. The optimum cement system contained 10% ordinary Portland cement, 84% gg blast furnace slag, 6% microsilica with a water cement ratio of 0.5 and a dry resin loading of 36% with respect to total weight. This formulation was successfully scaled up to 200 litres giving a product with acceptable compressive strength, dimensional stability and elastic modulus. Storage of samples under water appears to have no detrimental effects on the products' properties. (author)

  19. Use of rubber crumbs in cement concrete

    Science.gov (United States)

    Longvinenko, A. A.

    2018-03-01

    Rubber crumb obtained from worn out tires has been increasingly used over the last 15-20 years, especially in manufacture of asphalt and cement concrete mixtures. This review pays principal attention to application of the rubber crumb to cement concrete mixtures. Use of the rubber crumb in cement concrete is not as successful as in asphalt concrete mixtures, due to incompatibility problems linked to chemical composition and a significant difference in rigidity between the rubber crumb and concrete mixture aggregates. Different methods are proposed and studied to mitigate the adverse influence and increase the beneficial effects of the rubber crumb when added to cement concrete.

  20. Controls on Cementation in a Chalk Reservoir

    DEFF Research Database (Denmark)

    Meireles, Leonardo Teixeira Pinto; Hussein, A.; Welch, M.J.

    2017-01-01

    In this study, we identify different controls on cementation in a chalk reservoir. Biot’s coefficient, a measure of cementation, stiffness and strength in porous rocks, is calculated from logging data (bulk density and sonic Pwave velocity). We show that Biot’s coefficient is correlated...... that some degree of pore filling cementation occurred in Kraka (Alam, 2010). Lack of correlation between Biot’s coefficient and Gamma Ray (GR) indicates that the small amount of clay present is generally located in the pore space, thus not contributing to frame stiffness. While there was no compositional...... control on cementation via clay, we could infer that stratigraphy impacts on the diagenetic process....

  1. Immobilisation of radwaste in cement based matrices

    International Nuclear Information System (INIS)

    Glasser, F.P.; Macphee, D.; Atkins, M.; Pointer, C.; Cowie, J.; Wilding, C.R.; Mattingley, N.J.; Evans, P.A.

    1989-01-01

    The solubilities and influence on cement pH are reported for calcium aluminate and aluminosulphate hydrates. The solubility of Ca(OH) 2 is reported to 700 bars. Polymerization of C-S-H is investigated by NMR. Specific interactions of U 6+ and iodine (I - , IO 3 - ) with cement components are described. The impact of radiation on cements and the influence of higher temperature are documented. The role of dissolved Ca and CO 2 in groundwaters as dissolution media for cements are reported. (author)

  2. Integer programming of cement distribution by train

    Science.gov (United States)

    Indarsih

    2018-01-01

    Cement industry in Central Java distributes cement by train to meet daily demand in Yogyakarta and Central Java area. There are five destination stations. For each destination station, there is a warehouse to load cements. Decision maker of cement industry have a plan to redesign the infrastructure and transportation system. The aim is to determine how many locomotives, train wagons, and containers and how to arrange train schedules with subject to the delivery time. For this purposes, we consider an integer programming to minimize the total of operational cost. Further, we will discuss a case study and the solution the problem can be calculated by LINGO software.

  3. Prediction of hydroxyl concentrations in cement pore water using a numerical cement hydration model

    NARCIS (Netherlands)

    Eijk, van R.J.; Brouwers, H.J.H.

    2000-01-01

    In this paper, a 3D numerical cement hydration model is used for predicting alkali and hydroxyl concentrations in cement pore water. First, this numerical model is calibrated for Dutch cement employing both chemical shrinkage and calorimetric experiments. Secondly, the strength development of some

  4. Evaluation of cement thixotropy for the cement of oil wells in areas ...

    African Journals Online (AJOL)

    ... economical for cementing job operations in wells with loss zones. The results also show that the effect of LHF is positive, since in addition to his contribution to long term performances, especially the durability of hardened concrete, it improves the thixotropy of cement made of plaster. Keywords: cementing; lost circulation; ...

  5. The ovens of the industry of the cement and their contribution to the handling of solid residuals and dangerous

    International Nuclear Information System (INIS)

    Riveros Rojas, Marcelo

    1995-01-01

    The substitution of certain row matters in the process of elaboration of the cement, as flying ashes, polluted soils with petroleum, muds of the industry of the petroleum, oxides of the industry of the steel, foundry sand and tires, they can replace until 40% of the necessities of energy of a cement oven contributing to improve the conservation of the environment. This new technology is using with success in United States and some countries of Europe

  6. Geotechnical Properties of Clayey Soil Stabilized with Cement ...

    African Journals Online (AJOL)

    ADOWIE PERE

    2017-12-31

    Dec 31, 2017 ... ... to investigate the different effects of cement-sawdust ash and cement on a ... Keywords: Cement, Saw dust, strength test subgrade material, highway construction ... characteristics of lateritic soil stabilized with sawdust ash.

  7. Studies on cement matrix materials used at the Radioactive Waste Treatment Plant for radwaste conditioning

    International Nuclear Information System (INIS)

    Dragolici, Felicia; Lungu, Laura; Nicu, Mihaela; Rotarescu, Gheorghe; Turcanu, Corneliu

    2003-01-01

    The research activities performed by Department of Radioactive Waste Management is focused on the treatment of LLAW products obtained by chemical precipitation and on the conditioning of these products by cementation. The individual mechanisms implied in the chemical precipitation processes are directly dependent on the precipitate properties and structure, which in turn are connected with the initial system composition and the precipitation procedure, i.e. reagent concentration, rate and orders of chemical addition, mixing rate and time and ageing conditions. In case of conditioning by cementation, the chemical nature and proportion of the sludges or concentrates affect both the hydrolysis of the initial cement components and the reactions of metastable hydration constituents, as well as the mechanical strength and chemical resistance of the hardened cemented matrix.Generally, the study of the precipitation products and their behaviour during cementation and the long-term disposal is extremely difficult because of the system complexity (phase composition and structure) and the lack of the non-destructive analytical methods. The experience accumulated by the countries who advanced nuclear programmes in military and socio-economic fields and which produced important volumes of radioactive wastes, leads us to study some of mineral additives to be used in the conditioning and disposal technology. Is well known that some mineral additives can diminish the leaching rate of the radionuclides in the disposal environment.The studies have the purpose to obtain the most propitious mixture of cement-bentonite and cement-volcanic tuff, which have the mechanical properties similar to the cement paste used for the conditioning of radioactive waste.Taking into account the characteristics of these mineral binders, namely a very good plasticity and capacity of adsorption, which lead at the decrease of porosity, the mixture is planned to be used in the future, at the Radioactive

  8. Economic benefits of reducing emissions from the cement industry

    International Nuclear Information System (INIS)

    El-Fadel, M.; Metni, M.; Nuwayhid, M.I.; Kobrossi, R.

    1999-01-01

    Full text.Air pollution has recently been a growing concern in Lebanon particularly around industrial facilities and in urban areas. The cement industry constitutes a major polluting source and its impacts have historically raised considerable local public concern, as was previously the case in many developed countries. In this context, the town of Chekka, which is the site of four cement factories, has been the subject of long-lived controversy with respect to emissions and potential adverse environmental impacts. While field observations and public health complains support the presence of such impacts., scientific data are almost non-existent to adequately evaluate the actual situation. This paper describes recent efforts conducted towards a proper air quality characterization in order to shed light on the extent and nature of the impact of the cement industry in the Chekka region on its immediate vicinity. For this purpose, continuous monitoring of selected air pollutants (particulate matter, nitrogen dioxide, and carbon monoxide) was conducted during a limited period. In addition, pollutant dispersion modeling was performed to better define exposure areas. Field measurements coupled with simulation results were linked to a survey questionnaire to assess potential health and material damage on a sample area. The economic benefits of emissions reduction of selected pollutants are presented in the context of the results obtained during this study

  9. Rietveld analysis, powder diffraction and cement

    International Nuclear Information System (INIS)

    Peterson, V.

    2002-01-01

    Full text: Phase quantification of cement is essential in its industrial use, however many methods are inaccurate and/or time consuming. Powder diffraction is one of the more accurate techniques used for quantitative phase analysis of cement. There has been an increase in the use of Rietveld refinement and powder diffraction for the analysis and phase quantification of cement and its components in recent years. The complex nature of cement components, existence of solid solutions, polymorphic variation of phases and overlapping phase peaks in diffraction patterns makes phase quantification of cements by powder diffraction difficult. The main phase in cement is alite, a solid solution of tricalcium silicate. Tricalcium silicate has been found to exist in seven modifications in three crystal systems, including triclinic, monoclinic, and rhombohedral structures. Hence, phase quantification of cements using Rietveld methods usually involves the simultaneous modelling of several tricalcium silicate structures to fit the complex alite phase. An industry ordinary Portland cement, industry and standard clinker, and a synthetic tricalcium silicate were characterised using neutron, laboratory x-ray and synchrotron powder diffraction. Diffraction patterns were analysed using full-profile Rietveld refinement. This enabled comparison of x-ray, neutron and synchrotron data for phase quantification of the cement and examination of the tricalcium silicate. Excellent Rietveld fits were achieved, however the results showed that the quantitative phase analysis results differed for some phases in the same clinker sample between various data sources. This presentation will give a short introduction about cement components including polymorphism, followed by the presentation of some problems in phase quantification of cements and the role of Rietveld refinement in solving these problems. Copyright (2002) Australian X-ray Analytical Association Inc

  10. Compressive Strength and Physical Properties Behavior of Cement Mortars with addition of Cement Klin Dust

    OpenAIRE

    Auday A Mehatlaf

    2017-01-01

    Cement Klin Dust (CKD) was the waste of almost cement industry factories, so that in this paper utilization of CKD as filler in cement and/or concrete was the main objective. CKD from the Karbala cement factory had been used and analysis to know the chemical composition of the oxides was done. In this paper cement mortars with different weight percentages of CKD (0,5,10,20,30,40) had been prepared. Physical properties such as density and porosity were done in different age curing (3, 7, 28) d...

  11. The improved heat integration of cement production under limited process conditions: A case study for Croatia

    International Nuclear Information System (INIS)

    Boldyryev, Stanislav; Mikulčić, Hrvoje; Mohorović, Zoran; Vujanović, Milan; Krajačić, Goran; Duić, Neven

    2016-01-01

    Given that cement is the most widely used material for housing and modern infrastructure needs, this paper analyses the energy efficiency of the cement manufacturing processes for a particular cement plant. The cement industry is one of the largest consumers of carbon-containing primary energy sources and one of the primary polluters of the environment, emitting approximately 5% of global pollution. Energy consumption represents the largest part of the production cost for cement factories and has a significant influence on product prices. Given that it is realised in modern society that infrastructural projects lead to a higher level of economy and sustainability for countries, reducing the production cost in the cement industry is a very important problem. The authors analysed the energy consumption of a particular cement factory in Croatia to determine the minimum energy targets of production and proposed pathways to improve energy efficiency. The Process Integration approach was used in this study. Nevertheless, the features of the cement factory forced the research to update its methodological steps to propose real pathways for a retrofit project with the aim of achieving the optimal minimum temperature difference between process streams. There are various streams, including those that contain solid particles, gas and air streams, and streams, that should be cooled down rapidly; these facts become more complicated by the special construction of the process equipment, which causes heat transfer between some streams to be impossible. The main objective of this paper is to determine the potential of real energy savings and propose a solution for a new concept of heat exchanger network (HEN) that avoids the process traps and provides a feasible retrofit. The maximum heat recovery of that production of a particular type of cement was determined and improved when a HEN was built. The authors conclude that the energy consumption of the cement factory can be reduced by

  12. A Study on the Manufacturing Properties of Crack Self-Healing Capsules Using Cement Powder for Addition to Cement Composites

    OpenAIRE

    Choi, Yun-Wang; Oh, Sung-Rok; Choi, Byung-Keol

    2017-01-01

    We fabricated crack self-healing capsules using cement powder for mixing into cement composites and evaluated the properties of the capsule manufacturing process in this study. The manufacture of the self-healing capsules is divided into core production processing of granulating cement in powder form and a coating process for creating a wall on the surfaces of the granulated cement particles. The produced capsules contain unhardened cement and can be mixed directly with the cement composite m...

  13. Analysis of Chemical Composition of Portland Cement in Ghana: A Key to Understand the Behavior of Cement

    OpenAIRE

    Bediako, Mark; Amankwah, Eric Opoku

    2015-01-01

    The performance of Portland cement in concrete or mortar formation is very well influenced by chemical compositions among other factors. Many engineers usually have little information on the chemical compositions of cement in making decisions for the choice of commercially available Portland cement in Ghana. This work analyzed five different brands of Portland cement in Ghana, namely, Ghacem ordinary Portland cement (OPC) and Portland limestone cement (PLC), CSIR-BRRI Pozzomix, Dangote OPC, a...

  14. Influence of Cements Containing Calcareous Fly Ash as a Main Component Properties of Fresh Cement Mixtures

    Science.gov (United States)

    Gołaszewski, Jacek; Kostrzanowska-Siedlarz, Aleksandra; Ponikiewski, Tomasz; Miera, Patrycja

    2017-10-01

    The main goal of presented research was to examine usability of cements containing calcareous fly ash (W) from technological point of view. In the paper the results of tests concerning the influence of CEM II and CEM IV cements containing fly ash (W) on rheological properties, air content, setting times and plastic shrinkage of mortars are presented and discussed. Moreover, compatibility of plasticizers with cements containing fly ash (W) was also studied. Additionally, setting time and hydration heat of cements containing calcareous fly ash (W) were determined. In a broader aspect, the research contributes to promulgation of the possibility of using calcareous fly ash (W) in cement and concrete technology, what greatly benefits the environment protection (utilization of waste fly ash). Calcareous fly ash can be used successfully as the main component of cement. Cements produced by blending with processed fly ash or cements produced by interginding are characterized by acceptable technological properties. In respect to CEM I cements, cements containing calcareous fly ash worsen workability, decrease air content, delay setting time of mixtures. Cements with calcareous fly ash show good compatibility with plasticizers.

  15. The influence of cement type and temperature on chloride binding in cement paste

    DEFF Research Database (Denmark)

    Jensen, Ole Mejlhede; Korzen, Migge Sofie Hoffmann; Skibsted, Jørgen

    1998-01-01

    This paper describes effects of cement type and temperature on chloride binding in cement paste, which is an important subject in relation to life-time modelling of reinforced concrete structures. The influence of cement type on chloride binding is investigated by substituting cement with pure...... cement clinker. Both theoretical considerations and experimental data for chloride binding in cement pastes are presented. A physico-chemically based model to describe the influence of temperature on physical binding of chloride is presented. Solid-state 27Al and 29Si magic-angle spinning (MAS) nuclear...... magnetic resonance (NMR) spectroscopy has been used for quantification of the anhydrous and hydrated aluminate and silicate phases in the chloride exposed cement pastes. The 27Al isotropic chemical shift and nuclear quadrupole coupling is reported for a synthetic sample of Friedel's salt, Ca2Al(OH)6Cl×2H2O....

  16. Feasibility of producing nano cement in a traditional cement factory in Iraq

    Directory of Open Access Journals (Sweden)

    Sada Abdalkhaliq Hasan Alyasri

    2017-12-01

    Full Text Available This study investigates the economic feasibility of producing nano cement through the establishment of a production line within an existing cement factory. Creating a nano cement production line within the Alkufa Cement factory in Iraq is selected as a case study. Evaluation measures including internal rate of return (IRR, net present value (NPV and breakeven point (BEP are used to evaluate the possible gain that can be achieved from this option. The results demonstrated a positive NPV. The IRR is found to be 26.8% and BEP is reached within 3 years after the establishment of the line. This indicates that producing nano cement in the existing cement factory is economically feasible and can be more advantageous than the ordinary cement.

  17. Is it cement to be? Downhole cement that uses zeolite additive may offer lightweight alternative

    Energy Technology Data Exchange (ETDEWEB)

    Mahoney, J.

    2001-05-01

    C2C Zeolite Corporation produces zeolites from a large deposit near Cache Creek, British Columbia, and processes them for use as an additive in downhole cement well casings. Early research indicates that zeolites can significantly improve the way downhole cement is made in the oil industry. Zeolites are made up mostly of silicates of aluminum and calcium. They have a great ability to absorb water, resulting in a lighter and more fluid cement than is currently available. C2C claims that zeolites will reduce cement weight, column pressure and operator costs. The cost benefits of using lighter cement downhole includes easier moving, processing and handling of the mix. Initial research suggests that zeolites might prove to be viable alternatives to other cement lighteners such as silica fumes or flyash. Zeolite-based cement also performed reasonably well in freeze-thaw tests and showed good adhesion and no evidence of shrinkage in downhole tests. 3 figs.

  18. Cements in radioactive waste management. Characterization requirements of cement products for acceptance and quality assurance purposes

    International Nuclear Information System (INIS)

    Rahman, A.A.; Glasser, F.P.

    1987-01-01

    Cementitious materials are used as immobilizing matrices for low (LLW) and medium-level wastes (MLW) and are also components of the construction materials in the secondary barriers and the repositories. This report has concerned itself with a critical assessment of the quality assurance aspects of the immobilization and disposal of MLW and LLW cemented wastes. This report has collated the existing knowledge of the use and potential of cementitious materials in radioactive waste immobilization and highlighted the physico-chemical parameters. Subject areas include an assessment of immobilization objectives and cement as a durable material, waste stream and matrix characterization, quality assurance concepts, nature of cement-based systems, chemistry and modelling of cement hydration, role and effect of blending agents, radwaste-cement interaction, assessment of durability, degradative and radiolytic processes in cements and the behaviour of cement-based matrices and their near-field interactions with the environment and the repository conditions

  19. Shrinkage Properties of Cement Stabilized Gravel

    DEFF Research Database (Denmark)

    Lund, Mia Schou Møller; Hansen, Kurt Kielsgaard

    2014-01-01

    Cement stabilized gravel is an attractive material in road construction because its strength prop-erties are accommodating the increasingly higher requirements to the bearing capacity of a base course. However, reflection cracking of cement stabilized gravel is a major concern. In this pa...

  20. Development and design of a cementation process

    International Nuclear Information System (INIS)

    Vicente, R.

    1986-01-01

    The conceptual design of a facility for the immobilization of intermediate level liquid waste in cement is presented. The cementation process adopted a vibration assisted mixing process. The solidified waste is packed in 200 litres drum with barite concrete lining. The waste package is classified as Type A package for transport. (Author) [pt

  1. Development and design of a cementation process

    International Nuclear Information System (INIS)

    Vicente, R.

    1987-01-01

    The conceptual design of a facility for the immobilization of intermediate-level liquid wastes in cement is presented. The cementation process adopted a vibration assisted mixing process. The solidified waste is packed in 200 litres drum with barite concrete lining. The waste package is classified as Type A package for transport. (Author) [pt

  2. Investigation of a Hardened Cement Paste Grout

    DEFF Research Database (Denmark)

    Esteves, Luis Pedro; Sørensen, Eigil Verner

    This report documents a series of tests performed on a hardened cement paste grout delivered by the client, Det Norske Veritas A/S.......This report documents a series of tests performed on a hardened cement paste grout delivered by the client, Det Norske Veritas A/S....

  3. Chloride ingress in cement paste and mortar

    DEFF Research Database (Denmark)

    Jensen, Ole Mejlhede; Hansen, Per Freiesleben; Coats, Alison M.

    1999-01-01

    In this paper chloride ingress in cement paste and mortar is followed by electron probe microanalysis. The influence of several paste and exposure parameters on chloride ingress are examined (e.g., water-cement ratio, silica fume addition, exposure time, and temperature), The measurements...

  4. Basic Chemistry for the Cement Industry.

    Science.gov (United States)

    Turner, Mason

    This combined student workbook and instructor's guide contains nine units for inplant classes on basic chemistry for employees in the cement industry. The nine units cover the following topics: chemical basics; measurement; history of cement; atoms; bonding and chemical formulas; solids, liquids, and gases; chemistry of Portland cement…

  5. Facial skeletal augmentation using hydroxyapatite cement.

    Science.gov (United States)

    Shindo, M L; Costantino, P D; Friedman, C D; Chow, L C

    1993-02-01

    This study investigates the use of a new calcium phosphate cement, which sets to solid, microporous hydroxyapatite, for facial bone augmentation. In six dogs, the supraorbital ridges were augmented bilaterally with this hydroxyapatite cement. On one side, the hydroxyapatite cement was placed directly onto the bone within a subperiosteal pocket. On the opposite side, the cement was contained within a collagen membrane tubule and then inserted into a subperiosteal pocket. The use of collagen tubules facilitated easy, precise placement of the cement. All implants maintained their original augmented height throughout the duration of the study. They were well tolerated without extrusion or migration, and there was no significant sustained inflammatory response. Histologic studies, performed at 3, 6, and 9 months revealed that when the cement was placed directly onto bone, progressive replacement of the implant by bone (osseointegration of the hydroxyapatite with the underlying bone) without a loss of volume was observed. In contrast, when the cement-collagen tubule combination was inserted, primarily a fibrous union was noted. Despite such fibrous union, the hydroxyapatite-collagen implant solidly bonded to the underlying bone, and no implant resorption was observed. Hydroxyapatite cement can be used successfully for the experimental augmentation of the craniofacial skeleton and may be applicable for such uses in humans.

  6. Elaborating the History of Our Cementing Societies

    DEFF Research Database (Denmark)

    Cao, Zhi; Shen, Lei; Løvik, Amund N.

    2017-01-01

    Modern cities and societies are built fundamentally based on cement and concrete. The global cement production has risen sharply in the past decades due largely to urbanization and construction. Here we deployed a top-down dynamic material flow analysis (MFA) model to quantify the historical deve...

  7. TECHNOLOGICAL CHANGES IN THE CEMENT MANUFACTURING INDUSTRY.

    Science.gov (United States)

    WESSON, CARL E.

    THE PURPOSE OF THIS STUDY IS TO PRESENT A PRELIMINARY PICTURE OF OCCUPATIONAL CHANGES BROUGHT ABOUT IN THE MANUFACTURE OF CEMENT AS A RESULT OF INTRODUCING AUTOMATED EQUIPMENT. ONE AUTOMATED AND SEVERAL CONVENTIONAL TYPE CEMENT PLANTS WERE STUDIED. ANALYSIS OF DATA OBTAINED THROUGH RESEARCH AND DATA COLLECTED DURING THE STUDY REVEALED THAT…

  8. Pre-portland cements and geopolymers

    Czech Academy of Sciences Publication Activity Database

    Hanzlíček, Tomáš; Perná, Ivana; Ertl, Z.; Miller, S.M.

    2012-01-01

    Roč. 9, č. 1 (2012), s. 57-62 ISSN 1214-9705 Institutional research plan: CEZ:AV0Z30460519 Keywords : caementum * cement itious * calcareous cement Subject RIV: JN - Civil Engineering Impact factor: 0.530, year: 2011 http://www.irsm.cas.cz/materialy/acta_content/2012_01/5_Hanzlicek.pdf

  9. Contact dermatitis in cement workers in Isfahan

    Directory of Open Access Journals (Sweden)

    Iraji Fariba

    2006-01-01

    Full Text Available BACKGROUND: Due to recent industrialization and inadequately protected workers or in other words poor supervision on constructive workers habits in our large city of Isfahan cement contact dermatitis is relatively high especially among cement factory workers and constructive personnel. PURPOSES: To investigate the prevalence rate of cement contact dermatitis in cement factory workers in Isfahan. METHODS: A case-control clinical study was carried out by randomly selecing 150 factory workders and 150 official clerks in a cement factory in Isfahan in 2001. After a complete physical examination, data was recorded in observational checklists. FINDINGS: The percentages of contact dermatitis prevalences in the first and the second groups were 22% and 5.3% respectively. About 60% of cement workers with contact dermatitis were between 30-40 years of age. There was a direct relationship with age in both groups of the workers. In the high-exposure group, the hand eczema along was 70% but in the other group the percentage of involvement was the same in exposed and unexposed anatomical areas. CONCLUSIONS: There was a direct relationship between occurrence and the severity of involvement and duration of contact in the first group. Cent percent of cement workers had contact dermatitis after 10 or less years, but the percentage among the other group was 35%. LIMITATION: Irritant contact dermatitis to cement has not been detected.

  10. Leach characterization of cement encapsulated wastes

    International Nuclear Information System (INIS)

    Roy, D.M.; Scheetz, B.E.; Wakeley, L.D.; Barnes, M.W.

    1982-01-01

    Matrix encapsulation of defense nuclear waste as well as intermediate-level commercial wastes within a low-temperature cementitious composite were investigated. The cements for this study included both as-received and modified calcium silicate and calcium aluminate cements. Specimens were prepared following conventional formulation techniques designed to produce dense monoliths, followed by curing at 60 0 C. An alternative preparation procedure is contrasted in which the specimens were ''warm'' pressed in a uniaxial press at 150 0 C at 50,000 psi for 0.5 h. Specimens of the waste/cement composites were leached in deionized water following three different procedures which span a wide range of temperatures and solution saturation conditions. Aluminate and compositionally adjusted silicate cements exhibited a better retentivity for Cs and Sr than did the as-received silicate cement. 15 refs

  11. Conditioning of radioactive waste solutions by cementation

    International Nuclear Information System (INIS)

    Vejmelka, P.; Rudolph, G.; Kluger, W.; Koester, R.

    1992-02-01

    For the cementation of the low and intermediate level evaporator concentrates resulting from the reprocessing of spent fuel numerous experiments were performed to optimize the waste form composition and to characterize the final waste form. Concerning the cementation process, properties of the waste/cement suspension were investigated. These investigations include the dependence of viscosity, bleeding, setting time and hydration heat from the waste cement slurry composition. For the characterization of the waste forms, the mechanical, thermal and chemical stability were determined. For special cases detailed investigations were performed to determine the activity release from waste packages under defined mechanical and thermal stresses. The investigations of the interaction of the waste forms with aqueous solutions include the determination of the Cs/Sr release, the corrosion resistance and the release of actinides. The Cs/Sr release was determined in dependence of the cement type, additives, setting time and sample size. (orig./DG) [de

  12. Energetically Modified Cement (EMC) - Performance Mechanism

    Energy Technology Data Exchange (ETDEWEB)

    Ronin, Vladimir; Elfgren, Lennart [Luleaa Univ. of Technology (Sweden). Centre for High Performance Cement

    2003-03-01

    Energetically Modified Cements, EMC, made of intensively milled cement (50%) and fillers (50%) of quartz or fly ash have been compared to blends of Ordinary Portland Cement, OPC, and fillers. The EMCs have better properties than other blends and are comparable to unblended OPC. This remarkable fact can probably be explained as follows. The grinding process reduces the size of both cement grains and fillers. This combined with the creation of micro defects gives the ground cement a very high degree of hydration. The increased early hydration and a better distribution of hydration products results in an extensive pore size refinement of the hardened binder. This pore size refinement leads to a favorably reduced permeability and diffusivity and very good mechanical properties.

  13. Cement analysis using d + D neutrons

    International Nuclear Information System (INIS)

    Womble, Phillip C.; Paschal, Jon; Moore, Ryan

    2005-01-01

    In the cement industry, the primary concern is quality control. The earlier the cement industry can institute quality control upon their product, the more significant their savings in labor, energy and material. We are developing a prototype cement analyzer using pulsed neutrons from a d-D electronic neutron generator with the goal of ensuring quality control of cement in an on-line manner. By utilizing a low intensity d-D neutron source and a specially-designed moderator assembly, we are able to produce one of the safest neutron-based systems in the market. Also, this design includes some exciting new methods of data acquisition which may substantially reduce the final installation costs. In our proof-of-principle measurements, we were able to measure the primary components of cement (Al, Si, Ca and Fe) to limits required for the raw materials, the derived mixes and the clinkers utilizing this neutron generator

  14. Dentin-cement Interfacial Interaction

    Science.gov (United States)

    Atmeh, A.R.; Chong, E.Z.; Richard, G.; Festy, F.; Watson, T.F.

    2012-01-01

    The interfacial properties of a new calcium-silicate-based coronal restorative material (Biodentine™) and a glass-ionomer cement (GIC) with dentin have been studied by confocal laser scanning microscopy (CLSM), scanning electron microscopy (SEM), micro-Raman spectroscopy, and two-photon auto-fluorescence and second-harmonic-generation (SHG) imaging. Results indicate the formation of tag-like structures alongside an interfacial layer called the “mineral infiltration zone”, where the alkaline caustic effect of the calcium silicate cement’s hydration products degrades the collagenous component of the interfacial dentin. This degradation leads to the formation of a porous structure which facilitates the permeation of high concentrations of Ca2+, OH-, and CO32- ions, leading to increased mineralization in this region. Comparison of the dentin-restorative interfaces shows that there is a dentin-mineral infiltration with the Biodentine, whereas polyacrylic and tartaric acids and their salts characterize the penetration of the GIC. A new type of interfacial interaction, “the mineral infiltration zone”, is suggested for these calcium-silicate-based cements. PMID:22436906

  15. Cement and concrete options paper

    International Nuclear Information System (INIS)

    1999-10-01

    Greenhouse gas emissions associated with the production of concrete are projected to increase from 10.5 million tonnes in 1990 to almost 14 million tonnes in 2010. Over half of this amount will be non-energy related emissions of carbon dioxide resulting from the conversion of limestone to lime. According to this report by industry experts, the industry has an excellent record of improving energy efficiency and there are few easy gains remaining. Nevertheless, improvements in energy efficiency and fuel use, increased use of concrete where it can be shown to result in net reduction of GHG emissions, and partial replacement of cement by supplementary cementitious materials that involve no additional generation of GHGs, could yield an approximate reduction in carbon dioxide emissions of nearly seven million tons in 2010. The industry proposes three measures to realise these benefits: (1) encouraging replacement of fossil fuels by otherwise waste material, (2) encouraging increased use of concrete in constructing houses and roads, and (3) encouraging increased use of supplementary cementing materials. The industry is opposed to carbon or energy taxes that increase the cost of doing business, on the grounds that such taxes would adversely affect the industry's competitive position internationally. tabs

  16. Chemical alteration of cement hydrates by dissolution

    International Nuclear Information System (INIS)

    Sugiyama, Daisuke; Fujita, Tomonari; Nakanishi, Kiyoshi

    2000-01-01

    Cementitious material is a potential waste packaging and backfilling material for the radioactive waste disposal, and is expected to provide both physical and chemical containment. In particular, the sorption of radionuclides onto cementitious material and the ability to provide a high pH condition are very important parameters when considering the release of radionuclides from radioactive wastes. For the long term, in the geological disposal environment, cement hydrates will be altered by, for example, dissolution, chemical reaction with ions in the groundwater, and hydrothermal reaction. Once the composition or crystallinity of the constituent minerals of a cement hydrate is changed by these processes, the pH of the repository buffered by cementitious material and its sorption ability might be affected. However, the mechanism of cement alteration is not yet fully understood. In this study, leaching experiments of some candidate cements for radioactive waste disposal were carried out. Hydrated Ordinary Portland Cement (OPC), Blast Furnace Slag blended cement (OPC/BFS) and Highly containing Flyash and Silicafume Cement (HFSC) samples were contacted with distilled water at liquid:solid ratios of 10:1, 100:1 and 1000:1 at room temperature for 200 days. In the case of OPC, Ca(OH) 2 dissolved at high liquid:solid ratios. The specific surface area of all cement samples increased by leaching process. This might be caused by further hydration and change of composition of constituent minerals. A model is presented which predicts the leaching of cement hydrates and the mineral composition in the hydrated cement solid phase, including the incongruent dissolution of CSH gel phases and congruent dissolution of Ca(OH) 2 , Ettringite and Hydrotalcite. Experimental results of dissolution of Ca-O-H and Ca-Si-O-H phases were well predicted by this model. (author)

  17. CONCRETE BASED ON MODIFIED DISPERSE CEMENT SYSTEM

    Directory of Open Access Journals (Sweden)

    D. V. Rudenko

    2016-08-01

    Full Text Available Purpose. The article considers definition of the bond types occurring in a modified cement concrete matrix, and the evaluation of the quality of these links in a non-uniform material to determine the geometrical and physical relationships between the structure and the cement matrix modifiers. Methodology. To achieve this purpose the studies covered the microstructure of dispersed modified concrete cement matrix, the structure formation mechanism of the modified cement concrete system of natural hardening; as well as identification of the methods of sound concrete strength assessment. Findings. The author proposed a model of the spatial structure of the concrete cement matrix, modified by particulate reinforcement crystal hydrates. The initial object of study is a set of volume elements (cells of the cement matrix and the system of the spatial distribution of reinforcing crystallohydrates in these volume elements. It is found that the most dangerous defects such as cracks in the concrete volume during hardening are formed as a result of internal stresses, mainly in the zone of cement matrix-filler contact or in the area bordering with the largest pores of the concrete. Originality. The result of the study is the defined mechanism of the process of formation of the initial strength and stiffness of the modified cement matrix due to the rapid growth of crystallohydrates in the space among the dispersed reinforcing modifier particles. Since the lack of space prevents from the free growth of crystals, the latter cross-penetrate, forming a dense structure, which contributes to the growth of strength. Practical value. Dispersed modifying cement matrix provides a durable concrete for special purposes with the design performance characteristics. The developed technology of dispersed cement system modification, the defined features of its structure formation mechanism and the use of congruence principle for the complex of technological impacts of physical

  18. Microscale Investigation of Arsenic Distribution and Species in Cement Product from Cement Kiln Coprocessing Wastes

    Directory of Open Access Journals (Sweden)

    Yufei Yang

    2013-01-01

    Full Text Available To improve the understanding of the immobilization mechanism and the leaching risk of Arsenic (As in the cement product from coprocessing wastes using cement kiln, distribution and species of As in cement product were determined by microscale investigation methods, including electron probe microanalysis (EPMA and X-ray absorption spectroscopy. In this study, sodium arsenate crystals (Na3AsO412H2O were mixed with cement production raw materials and calcined to produce cement clinker. Then, clinker was mixed water to prepare cement paste. EPMA results showed that As was generally distributed throughout the cement paste. As content in calcium silicate hydrates gel (C-S-H was in low level, but higher than that in other cement mineral phases. This means that most of As is expected to form some compounds that disperse on the surfaces of cement mineral phases. Linear combination fitting (LCF of the X-ray absorption near edge structure spectra revealed that As in the cement paste was predominantly As(V and mainly existed as Mg3(AsO42, Ca3(AsO42, and Na2HAsO4.

  19. Cement-in-cement acetabular revision with a constrained tripolar component.

    Science.gov (United States)

    Leonidou, Andreas; Pagkalos, Joseph; Luscombe, Jonathan

    2012-02-17

    Dislocation of a total hip replacement (THR) is common following total hip arthroplasty (THA). When nonoperative management fails to maintain reduction, revision surgery is considered. The use of constrained acetabular liners has been extensively described. Complete removal of the old cement mantle during revision THA can be challenging and is associated with significant complications. Cement-in-cement revision is an established technique. However, the available clinical and experimental studies focus on femoral stem revision. The purpose of this study was to present a case of cement-in-cement acetabular revision with a constrained component for recurrent dislocations and to investigate the current best evidence for this technique. This article describes the case of a 74-year-old woman who underwent revision of a Charnley THR for recurrent low-energy dislocations. A tripolar constrained acetabular component was cemented over the primary cement mantle following removal of the original liner by reaming, roughening the surface, and thoroughly irrigating and drying the primary cement. Clinical and radiological results were good, with the Oxford Hip Score improving from 11 preoperatively to 24 at 6 months postoperatively. The good short-term results of this case and the current clinical and biomechanical data encourage the use of the cement-in-cement technique for acetabular revision. Careful irrigation, drying, and roughening of the primary surface are necessary. Copyright 2012, SLACK Incorporated.

  20. Detecting Poor Cement Bonding and Zonal Isolation Problems Using Magnetic Cement Slurries

    KAUST Repository

    Nair, Sriramya D.; Patzek, Tadeusz; van Oort, Eric

    2017-01-01

    There has been growing interest in the use of magnetorheological fluids to improve displacement efficiency of fluids (drilling fluids, spacer fluids, cement slurries) in the eccentric casing annuli. When magnetic particles are mixed with the cement slurry for improved displacement, they provide an excellent opportunity for sensing the presence and quality of cement in the annulus. This work focuses on using sophisticated 3D computational electromagnetics to simulate the use of a magnetic cement slurry for well cement monitoring. The main goal is to develop a new tool, which is capable of locating magnetic cement slurry that is placed behind a stainless steel casing. An electromagnetic coil was used to generate a magnetic field inside the borehole. It was found that when a current was passed through the electric coils, magnetic field lines passed through the stainless steel casing, the cement annulus and the rock formation. Three sensors were placed inside the cased borehole and the magnetic field strength variations were observed at these locations. Various factors that have a significant influence on zonal isolation were considered. These include, effect of debonding between casing and cement annulus, effect of changing annuli thickness, influence of a fracture in the rock formation, effect of changing magnetic permeability of cement and finally influence of annuli eccentricity. Based on the results shown in the paper along with the next generation of supersensitive magnetic sensors that are being developed, the magnetic approach appears to be a viable alternative for evaluating the quality of the cement annulus to ensure good zonal isolation.

  1. Sustainable Development of the Cement Industry and Blended Cements to Meet Ecological Challenges

    Directory of Open Access Journals (Sweden)

    Konstantin Sobolev

    2003-01-01

    Full Text Available The world production of cement has greatly increased in the past 10 years. This trend is the most significant factor affecting technological development and the updating of manufacturing facilities in the cement industry. Existing technology for the production of cement clinker is ecologically damaging; it consumes much energy and natural resources and also emits pollutants. A new approach to the production of blended or high-volume mineral additive (HVMA cement helps to improve its ecological compatibility. HVMA cement technology is based on the intergrinding of portland cement clinker, gypsum, mineral additives, and a special complex admixture. This new method increases the compressive strength of ordinary cement, improves durability of the cement-based materials, and - at the same time - uses inexpensive natural mineral additives or industrial by-products. This improvement leads to a reduction of energy consumption per unit of the cement produced. Higher strength, better durability, reduction of pollution at the clinker production stage, and decrease of landfill area occupied by industrial by-products, all provide ecological advantages for HVMA cement.

  2. Detecting Poor Cement Bonding and Zonal Isolation Problems Using Magnetic Cement Slurries

    KAUST Repository

    Nair, Sriramya D.

    2017-10-02

    There has been growing interest in the use of magnetorheological fluids to improve displacement efficiency of fluids (drilling fluids, spacer fluids, cement slurries) in the eccentric casing annuli. When magnetic particles are mixed with the cement slurry for improved displacement, they provide an excellent opportunity for sensing the presence and quality of cement in the annulus. This work focuses on using sophisticated 3D computational electromagnetics to simulate the use of a magnetic cement slurry for well cement monitoring. The main goal is to develop a new tool, which is capable of locating magnetic cement slurry that is placed behind a stainless steel casing. An electromagnetic coil was used to generate a magnetic field inside the borehole. It was found that when a current was passed through the electric coils, magnetic field lines passed through the stainless steel casing, the cement annulus and the rock formation. Three sensors were placed inside the cased borehole and the magnetic field strength variations were observed at these locations. Various factors that have a significant influence on zonal isolation were considered. These include, effect of debonding between casing and cement annulus, effect of changing annuli thickness, influence of a fracture in the rock formation, effect of changing magnetic permeability of cement and finally influence of annuli eccentricity. Based on the results shown in the paper along with the next generation of supersensitive magnetic sensors that are being developed, the magnetic approach appears to be a viable alternative for evaluating the quality of the cement annulus to ensure good zonal isolation.

  3. Parameters of Alumina Cement and Portland Cement with Addition of Chalcedonite Meal

    Science.gov (United States)

    Kotwa, Anna

    2017-10-01

    Aluminous cement is a quick binder with special properties. It is used primarily to make non-standard monolithic components exposed to high temperatures, + 1300°C. It is also a component of adhesives and mortars. It has a very short setting time. It is characterized by rapid increase in mechanical strength and resistance to aggressive sulphates. It can be used in reinforced concrete structures. Laying of concrete, construction mortar made of alumina cement can be carried out even at temperatures of -10°C. This article discusses a comparison of the parameters of hardened mortar made of alumina cement GÓRKAL 40 and Portland cement CEM I 42.5R. The mortars contain an addition of chalcedonite meal with pozzolanic properties, with particle size of less than 0.063μm. The meal was added in amounts of 5% and 20% of cement weight. Chalcedonite meal used in the laboratory research is waste material, resulting from chalcedonite aggregate mining. It has the same properties as the rock from which it originates. We have compared the parameters of hardened mortar i.e. compressive strength, water absorption and capillarity. The addition of 20% chalcedonite meal to mortars made from aluminous cement will decrease durability by 6.1% relative to aluminous cement mortar without addition of meal. Considering the results obtained during the absorbency tests, it can be stated that the addition of chalcedonite meal reduces weight gains in mortars made with cement CEM I 42.5 R and alumina cement. Use of alumina cement without addition of meal in mortars causes an increase of mass by 248% compared to Portland cement mortars without additions, in the absorption tests. The addition of chalcedonite meal did not cause increased weight gain in the capillary action tests. For the alumina cement mortars, a lesser weight gains of 24.7% was reported, compared to the Portland cement mortar after 28 days of maturing.

  4. DEVELOPING COUNTRIES. TRANSITION ECONOMIES

    Directory of Open Access Journals (Sweden)

    Dumitru FILIPEANU

    2016-05-01

    Full Text Available According to the modern theories of economic development – the take-off, backwardness, convergence and balanced growth hypothesis - the new industrialized states from Asia seem to have noticed the advantages of backwardness from which low income countries benefited, namely the possibility to take advantage of the latest technological discoveries of advanced countries, thus achieving a faster growth than the latter which operated closer to the technological border. The assimilation of appropriate technologies, however, required the efficient mobilization and allocation of resources and the improvement of human and physical capital. While the Western countries were confronted with crises generated by inflationary shocks and movements of speculative capital, the relative isolation of countries whose economy was planned by the world economy sheltered them until 1990, unemployment being practically non-existent. Asia's exceptional economic success is not only due to borrowing Western practices, but also to the fact that Asian societies maintained certain traditional features of their own culture - such as a strong work ethic - and integrated them in the modern business environment.

  5. Natural radioactivity of raw materials and products of cement manufacturing and of power plant fly ashes

    International Nuclear Information System (INIS)

    Gallyas, Miklos

    1984-01-01

    The natural radioactivity was investigated for several building materials used in Hungary, including cement, concrete, glasses, fine ceramic products, insulation materials, and also for some industrial wastes utilized as building material aggregates like slags, fly ashes etc., from their radiation health aspect. The dose commitments of the population from building materials standardized in several countries are presented. The 232 Th, 226 Ra, and 40 K contents of building materials were measured by gamma spectrometry, using NaI/Tl/scintillation detectors. The results were used to qualify cement materials and fly ash aggregates according to their origin in Hungary, from the point of view of their natural radioactivity. It was concluded that the radioactivity level of the majority of Hungarian cements are below the adopted international standards. (R.P.)

  6. Environmental Assessment of Different Cement Manufacturing ...

    Science.gov (United States)

    Due to its high environmental impact and energy intensive production, the cement industry needs to adopt more energy efficient technologies to reduce its demand for fossil fuels and impact on the environment. Bearing in mind that cement is the most widely used material for housing and modern infrastructure, the aim of this paper is to analyse the Emergy and Ecological Footprint of different cement manufacturing processes for a particular cement plant. There are several mitigation measures that can be incorporated in the cement manufacturing process to reduce the demand for fossil fuels and consequently reduce the CO2 emissions. The mitigation measures considered in this paper were the use of alternative fuels and a more energy efficient kiln process. In order to estimate the sustainability effect of the aforementioned measures, Emergy and Ecological Footprint were calculated for four different scenarios. The results show that Emergy, due to the high input mass of raw material needed for clinker production, stays at about the same level. However, for the Ecological Footprint, the results show that by combining the use of alternative fuels together with a more energy efficient kiln process, the environmental impact of the cement manufacturing process can be lowered. The research paper presents an analysis of the sustainability of cement production , a major contributor to carbon emissions, with respect to using alternative fuels and a more efficient kiln. It show

  7. Correlating cement characteristics with rheology of paste

    International Nuclear Information System (INIS)

    Vikan, H.; Justnes, H.; Winnefeld, F.; Figi, R.

    2007-01-01

    The influence of cement characteristics such as cement fineness and clinker composition on the 'flow resistance' measured as the area under the shear stress-shear rate flow curve has been investigated. Three different types of plasticizers namely naphthalene sulphonate-formaldehyde condensate, polyether grafted polyacrylate, and lignosulphonate have been tested in this context on 6 different cements. The flow resistance correlated well with the cement characteristic (Blaine.{d.cC 3 A + [1 - d].C 3 S}) where the factor d represents relative reactivity of cubic C 3 A and C 3 S while cC 3 A and C 3 S represent the content of these minerals. It was found to be either a linear or exponential function of the combined cement characteristic depending on plasticizer type and dosage. The correlation was valid for a mix of pure cement and cement with fly ash, limestone filler (4%), as well as pastes with constant silica fume dosage, when the mineral contents were determined by Rietveld analysis of X-ray diffractograms

  8. 21 CFR 888.3027 - Polymethylmethacrylate (PMMA) bone cement.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Polymethylmethacrylate (PMMA) bone cement. 888... Polymethylmethacrylate (PMMA) bone cement. (a) Identification. Polymethylmethacrylate (PMMA) bone cement is a device...: Polymethylmethacrylate (PMMA) Bone Cement.” [67 FR 46855, July 17, 2002] ...

  9. Effect of Cement Grades on some properties of Sandcrete ...

    African Journals Online (AJOL)

    The purpose of this study is to investigate the effects of cement grade on some properties of sandcrete. The cement used for this work was Ordinary Portland cement (Dangote brand) of grade 42.5 and 32.5 meeting the requirement of ASTM C150 type 1 cement. Three types of fine aggregate was also used to produce ...

  10. Energy economy and industrial ecology in the Brazilian cement sector

    International Nuclear Information System (INIS)

    Tavares, Marina Elisabete Espinho; Schaeffer, Roberto

    1999-01-01

    The article discusses the following issues of the Brazilian cement sector: the Brazilian cement main types specification, cement quantities evolution produced in Brazil from 1987 to 1997, energy conservation in the cement production process with additives, energy economy cost estimates from the utilization of additives, and several technologies energy economy cost used in the industrial sector

  11. Thermal behavior of asphalt cements

    International Nuclear Information System (INIS)

    Claudy, P.M.; Letoffe, J.M.; Martin, D.; Planche, J.P.

    1998-01-01

    Asphalt cements are highly complex mixtures of hydrocarbon molecules whose thermal behavior is of prime importance for petroleum and road industry. From DSC, the determination of several thermal properties of asphalts is given, e.g. glass-transition temperature and crystallized fraction content.The dissolution of a pure n-paraffin C n H 2n+2 in an asphalt, as seen by DSC, should be a single peak. For 20 g of these glasses change with time and temperature. The formation of the crystallized phases is superposed to the enthalpic relaxation of the glasses, making a kinetic study very difficult. (Copyright (c) 1998 Elsevier Science B.V., Amsterdam. All rights reserved.)

  12. Western blotting.

    Science.gov (United States)

    Kurien, Biji T; Scofield, R Hal

    2006-04-01

    Western blotting (protein blotting or immunoblotting) is a powerful and important procedure for the immunodetection of proteins post-electrophoresis, particularly proteins that are of low abundance. Since the inception of the protocol for protein transfer from an electrophoresed gel to a membrane in 1979, protein blotting has evolved greatly. The scientific community is now confronted with a variety of ways and means to carry out this transfer. This review describes the various procedures that have been used to transfer proteins from a gel to a membrane based on the principles of simple diffusion, vacuum-assisted solvent flow and electrophoretic elution. Finally, a brief description of methods generally used to detect antigens on blots is also described.

  13. Operating experience with KRAFTWERK UNION cementation line

    International Nuclear Information System (INIS)

    Podmaka, L.; Tomik, L.

    1988-01-01

    A facility is described designed for fixation in a cement matrix of the radioactive concentrate produced by thickening waste water from the Bohunice nuclear power plant. The cementation line output is 0.6 m 3 concentrate/h. The concentrate is put in 200 l drums. The individual operating units, cement management, air conditioning, dosimetric monitoring and the building part are described. The requirements for the operators and the assessment of the quality of raw materials and the product are discussed. (M.D.). 3 figs., 4 refs

  14. Synthesis of pure Portland cement phases

    DEFF Research Database (Denmark)

    Wesselsky, Andreas; Jensen, Ole Mejlhede

    2009-01-01

    Pure phases commonly found in Portland cement clinkers are often used to test cement hydration behaviour in simplified experimental conditions. The synthesis of these phases is covered in this paper, starting with a description of phase relations and possible polymorphs of the four main phases...... in Portland cement, i.e. tricalcium silicate, dicalcium silicate, tricalcium aluminate and tetracalcium alumino ferrite. Details of the The process of solid state synthesis are is described in general including practical advice on equipment and techniques. Finally In addition, some exemplary mix compositions...

  15. Estimation and measurement of porosity change in cement paste

    International Nuclear Information System (INIS)

    Lee, Eunyong; Jung, Haeryong; Kwon, Ki-jung; Kim, Do-Gyeum

    2011-01-01

    Laboratory-scale experiments were performed to understand the porosity change of cement pastes. The cement pastes were prepared using commercially available Type-I ordinary Portland cement (OPC). As the cement pastes were exposed in water, the porosity of the cement pastes sharply increased; however, the slow decrease of porosity was observed as the dissolution period was extended more than 50 days. As expected, the dissolution reaction was significantly influenced by w/c ratio and the ionic strength of solution. A thermodynamic model was applied to simulate the porosity change of the cement pastes. It was highly influenced by the depth of the cement pastes. There was porosity increase on the surface of the cement pastes due to dissolution of hydration products, such as portlandite, ettringite, and CSH. However, the decrease of porosity was estimated inside the cement pastes due to the precipitation of cement minerals. (author)

  16. Compressive Strength and Physical Properties Behavior of Cement Mortars with addition of Cement Klin Dust

    Directory of Open Access Journals (Sweden)

    Auday A Mehatlaf

    2017-12-01

    Full Text Available Cement Klin Dust (CKD was the waste of almost cement industry factories, so that in this paper utilization of CKD as filler in cement and/or concrete was the main objective. CKD from the Karbala cement factory had been used and analysis to know the chemical composition of the oxides was done. In this paper cement mortars with different weight percentages of CKD (0,5,10,20,30,40 had been prepared. Physical properties such as density and porosity were done in different age curing (3, 7, 28 day. In addition, mechanical properties included the coefficient of thermal conductivity and compressive strength had also observed with different age (3,7, and 28 for all prepared specimens. From the obtained the experimental results and their discussion, it was clear that the addition (20% of CKD had the good results in cement mortars.  

  17. Characterization and chemical activity of Portland cement and two experimental cements with potential for use in dentistry.

    Science.gov (United States)

    Camilleri, J

    2008-09-01

    To evaluate the chemical activity of Portland cement and two other cement types with similar chemical composition to mineral trioxide aggregate with the aim of developing these cements for further applications in dentistry. The chemical composition of the three cement types namely Portland cement, calcium sulpho-aluminate cement and calcium fluoro-aluminate cement was evaluated by elemental analysis using energy dispersive analysis with X-ray under the scanning electron microscope and by X-ray diffraction analysis (XRD) to determine the phases. The constituents of the hydration reaction by-products were evaluated by XRD analysis of the set cements at 1, 7, 28 and 56 days and by analysis of the leachate by ion chromatography. The pH of both cements and leachate was determined at different time intervals. Cements admixed with micro-silica were also tested to determine the effect of micro-silica on the reaction by-products. All three cement types were composed of tricalcium silicate as the main constituent phase. The hydration reaction of Portland cement produced calcium hydroxide. However, this was not present in the other cements tested at all ages. Admixed micro-silica had little or no effect on the cements with regard to reaction by-products. The pH of all cements tested was alkaline. Both the experimental calcium sulpho-aluminate cement and calcium fluoro-aluminate cement had different hydration reactions to that of Portland cement even though calcium silicate was the major constituent element of both cement types. No calcium hydroxide was produced as a by-product to cement hydration. Micro-silica addition to the cement had no effect on the hydration reaction.

  18. Gamma Spectrometry Analysis of Different Brands of Cement used in Nigeria

    International Nuclear Information System (INIS)

    Olarinoye, I.O.; Baba-Kutigi, A.N.; Sharifat, I.; Kolo, M.T.

    2014-01-01

    The natural radionuclide content of common brands of cement consumed in Nigeria is presented in this work. Samples of 9 brands of grey ordinary Portland cement (OPC) and 5 brands of white cement were collected and analyzed for their radiological content by gamma spectrometry using a 7.6 x 7.6 NaI(TI) detector. The total average content of 226 Ra, 232 Th and 40 k for all the cement brand samples were 38.1, 27.9 and 301.1 Bq/kg respectively and are lower when compared to the world average (50, 50 and 500 Bq/Kg) in building materials. The evaluated radium equivalent activities, external and internal indices were lower than the recommended safe limit and are comparable with result from similar studies concluded in other countries. The evaluation mean gonadal dose of equivalents of two cement brand samples were found to be higher than the world average in soil while others are less than the world average in soil.

  19. Radiation dose estimation and mass attenuation coefficients of cement samples used in Turkey

    International Nuclear Information System (INIS)

    Damla, N.; Cevik, U.; Kobya, A.I.; Celik, A.; Celik, N.; Van Grieken, R.

    2010-01-01

    Different cement samples commonly used in building construction in Turkey have been analyzed for natural radioactivity using gamma-ray spectrometry. The mean activity concentrations observed in the cement samples were 52, 40 and 324 Bq kg -1 for 226 Ra, 232 Th and 40 K, respectively. The measured activity concentrations for these radionuclides were compared with the reported data of other countries and world average limits. The radiological hazard parameters such as radium equivalent activities (Ra eq ), gamma index (I γ ) and alpha index (I α ) indices as well as terrestrial absorbed dose and annual effective dose rate were calculated and compared with the international data. The Ra eq values of cement are lower than the limit of 370 Bq kg -1 , equivalent to a gamma dose of 1.5 mSv y -1 . Moreover, the mass attenuation coefficients were determined experimentally and calculated theoretically using XCOM in some cement samples. Also, chemical compositions analyses of the cement samples were investigated.

  20. 76 FR 50252 - Gray Portland Cement and Cement Clinker From Japan; Scheduling of an Expedited Five-Year Review...

    Science.gov (United States)

    2011-08-12

    ... INTERNATIONAL TRADE COMMISSION [Investigation No. 731-TA-461 (Third Review)] Gray Portland Cement and Cement Clinker From Japan; Scheduling of an Expedited Five-Year Review Concerning the Antidumping Duty Order on Gray Portland Cement and Cement Clinker From Japan AGENCY: United States International...

  1. Influence of Cement Particle-Size Distribution on Early Age Autogenous Strains and Stresses in Cement-Based Materials

    DEFF Research Database (Denmark)

    Bentz, Dale P.; Jensen, Ole Mejlhede; Hansen, Kurt Kielsgaard

    2001-01-01

    The influence of cement particle-size distribution on autogenous strains and stresses in cement pastes of identical water-to-cement ratios is examined for cement powders of four different finenesses. Experimental measurements include chemical shrinkage, to quantify degree of hydration; internal r...

  2. Effect of Abutment Modification and Cement Type on Retention of Cement-Retained Implant Supported Crowns

    OpenAIRE

    Farzin, Mitra; Torabi, Kianoosh; Ahangari, Ahmad Hasan; Derafshi, Reza

    2014-01-01

    Objective: Provisional cements are commonly used to facilitate retrievability of cement-retained fixed implant restorations; but compromised abutment preparation may affect the retention of implant-retained crowns.The purpose of this study was to investigate the effect of abutment design and type of luting agent on the retentive strength of cement-retained implant restorations. Materials and Method: Two prefabricated abutments were attached to their corresponding analogs and embedded in an ac...

  3. Foamed cement for squeeze cementing low-pressure, highly permeable reservoirs

    International Nuclear Information System (INIS)

    Chmllowski, W.; Kondratoff, L.B.

    1992-01-01

    Four different cement squeezing techniques have been used on wells producing from the Keg River formation in the Rainbow Lake area of Alberta, Canada. This paper evaluates 151 cement squeeze treatments performed at 96 wellsites and compares the use of foam cement vs. conventional squeeze treatments and techniques. Discussion includes key aspects, such as candidate selection, slurry design, treatment design, economic evaluation, and operational considerations

  4. Hydration of fly ash cement and microstructure of fly ash cement pastes

    Energy Technology Data Exchange (ETDEWEB)

    Shiyuan, H.

    1981-01-01

    The strength development and hydration of fly ash cement and the influence of addition of gypsum on those were studied at normal and elevated temperatures. It was found that an addition of a proper amount of gypsum to fly ash cement could accelerate the pozzolanic reaction between CH and fly ash, and as a result, increase the strength of fly ash cement pastes after 28 days.

  5. Nanofunctionalized zirconia and barium sulfate particles as bone cement additives

    Directory of Open Access Journals (Sweden)

    Riaz Gillani

    2009-12-01

    Full Text Available Riaz Gillani1, Batur Ercan1, Alex Qiao3, Thomas J Webster1,21Division of Engineering, 2Department of Orthopaedics, Brown University, Providence, RI, USA; 3G3 Technology Innovations, LLC, Pittsford, NY, USAAbstract: Zirconia (ZrO2 and barium sulfate (BaSO4 particles were introduced into a methyl methacrylate monomer (MMA solution with polymethyl methacrylate (PMMA beads during polymerization to develop the following novel bone cements: bone cements with unfunctionalized ZrO2 micron particles, bone cements with unfunctionalized ZrO2 nanoparticles, bone cements with ZrO2 nanoparticles functionalized with 3-(trimethoxysilylpropyl methacrylate (TMS, bone cements with unfunctionalized BaSO4 micron particles, bone cements with unfunctionalized BaSO4 nanoparticles, and bone cements with BaSO4 nanoparticles functionalized with TMS. Results demonstrated that in vitro osteoblast (bone-forming cell densities were greater on bone cements containing BaSO4 ceramic particles after four hours compared to control unmodified bone cements. Osteoblast densities were also greater on bone cements containing all of the ceramic particles after 24 hours compared to unmodified bone cements, particularly those bone cements containing nanofunctionalized ceramic particles. Bone cements containing ceramic particles demonstrated significantly altered mechanical properties; specifically, under tensile loading, plain bone cements and bone cements containing unfunctionalized ceramic particles exhibited brittle failure modes whereas bone cements containing nanofunctionalized ceramic particles exhibited plastic failure modes. Finally, all bone cements containing ceramic particles possessed greater radio-opacity than unmodified bone cements. In summary, the results of this study demonstrated a positive impact on the properties of traditional bone cements for orthopedic applications with the addition of unfunctionalized and TMS functionalized ceramic nanoparticles

  6. Cement stabilization of hazardous and radioactive electroplating sludge

    International Nuclear Information System (INIS)

    Langton, C.A.; Pickett, J.B.; Martin, M.L.

    1991-01-01

    Cement stabilization was evaluated for treatment of nickel and uranium in electroplating sludge at the Savannah River Site. Waste forms were prepared by pretreating the sludge and the solidifying it in a variety of cement, cement plus flyash, and cement-flyash-slag mixes. The sludge was also treated by one-step filtration-solidification. Leaching results and processing data indicate the cement solidification is an effective method of treating hazardous-low-level electroplating waste

  7. experimental study of cement grout: rheological behavior and sedimentation

    OpenAIRE

    Rosquoët , Frédéric; Alexis , Alain ,; Khelidj , Abdelhafid; Phelipot-Mardelé , Annabelle

    2002-01-01

    International audience; Three basic elements (cement, water and admixture) usually make up injectable cement grouts used for prestressed cable coating, repair and consolidation of masonry, soil grouting, etc... The present study was divided into two parts. First, in order to characterize rheologically fresh cement paste with W/C ratios (water/cement ratio) varying between 0.35 and 1, an experimental study was carried out and has revealed that the cement past behaves like a shear-thinning mate...

  8. Nanoscaled Mechanical Properties of Cement Composites Reinforced with Carbon Nanofibers

    OpenAIRE

    Barbhuiya, Salim; Chow, PengLoy

    2017-01-01

    This paper reports the effects of carbon nanofibers (CNFs) on nanoscaled mechanical properties of cement composites. CNFs were added to cement composites at the filler loading of 0.2 wt % (by wt. of cement). Micrographs based on scanning electron microscopy (SEM) show that CNFs are capable of forming strong interfacial bonding with cement matrices. Experimental results using nanoindentation reveal that the addition of CNFs in cement composites increases the proportions of high-density calcium...

  9. Effect of Cement Composition in Lampung on Concrete Strength

    OpenAIRE

    Riyanto, Hery

    2014-01-01

    The strength and durability of concrete depends on the composition of its constituent materials ie fine aggregate, coarse aggregate, cement, water and other additives. The cement composition is about 10% acting as a binder paste material fine and coarse aggregates. In the Lampung market there are several brands of portland cement used by the community to make concrete construction. Although there is a standard of the government of portland cement composition, yet each brand of cement has diff...

  10. INFLUENCE OF WINE ACID ON RHEOLOGICAL PROPERTIES OF WELL BORE CEMENT SLURRIES AND HARDENED CEMENT PROPERTIES

    Directory of Open Access Journals (Sweden)

    Nediljka Gaurina-Međimurec

    1989-12-01

    Full Text Available Adaptation of commercial types of domestic cements for use in cementing the deep wells is a process by which Yugoslav oil industry tends to solve problems of completion of those wells independently. In order to design a domestic, cheep and effective retarder, tests of applicability of wine acid on cement slurries have been carried out. Besides examining the necessary wine acid content to achieve desirable Theological properties, the influence of this additive on properties of hardened cement samples has been tested too (the paper is published in Croatian.

  11. Basalt waste added to Portland cement

    Directory of Open Access Journals (Sweden)

    Thiago Melanda Mendes

    2016-08-01

    Full Text Available Portland cement is widely used as a building material and more than 4.3 billion tons were produced in 2014, with increasing environmental impacts by this industry, mainly through CO2 emissions and consumption of non-removable raw materials. Several by-products have been used as raw materials or fuels to reduce environmental impacts. Basaltic waste collected by filters was employed as a mineral mixture to Portland cement and two fractions were tested. The compression strength of mortars was measured after 7 days and Scanning Electron Microscopy (SEM and Electron Diffraction Scattering (EDS were carried out on Portland cement paste with the basaltic residue. Gains in compression strength were observed for mixtures containing 2.5 wt.% of basaltic residue. Hydration products observed on surface of basaltic particles show the nucleation effect of mineral mixtures. Clinker substitution by mineral mixtures reduces CO2 emission per ton of Portland cement.

  12. Subgrade stabilization alternatives to lime and cement.

    Science.gov (United States)

    2010-04-15

    This project involved four distinct research activities, (1) the influence of temperature on lime-stabilized soils, (2) the influence of temperature on cement-stabilized soils (3) temperature modeling of stabilized subgrade and (4) use of calcium chl...

  13. Cement materials for cesium and iodine confinement

    International Nuclear Information System (INIS)

    Nicolas, G.; Lequeux, N.; Boch, P.; Prene, S.

    2001-01-01

    The following topics were dealt with: radioactive waste storage, cement materials reacting with radioactive cesium and iodine, chemical barrier formation against radioactive pollution, ceramization, long term stability, XRD, PIXE analysis

  14. Recycled concrete aggregate in portland cement concrete.

    Science.gov (United States)

    2013-01-01

    Aggregates can be produced by crushing hydraulic cement concrete and are known as recycled concrete : aggregates (RCA). This report provides results from a New Jersey Department of Transportation study to identify : barriers to the use of RCA in new ...

  15. Recycled materials in Portland cement concrete

    Science.gov (United States)

    2000-06-01

    This report pertains to a comprehensive study involving the use of recycled materials in Portland cement concrete. Three different materials were studied including crushed glass (CG), street sweepings (SS), and recycled concrete (RC). Blast furnace s...

  16. Pore structure in blended cement pastes

    DEFF Research Database (Denmark)

    Canut, Mariana Moreira Cavalcanti

    Supplementary cementitious materials (SCMs), such as slag and fly ash, are increasingly used as a substitute for Portland cement in the interests of improvement of engineering properties and sustainability of concrete. According to studies improvement of engineering properties can be explained by...... on assumptions of degree of reaction and product densities gave for plain cement pastes results comparable to MIP data.......Supplementary cementitious materials (SCMs), such as slag and fly ash, are increasingly used as a substitute for Portland cement in the interests of improvement of engineering properties and sustainability of concrete. According to studies improvement of engineering properties can be explained...... supplement each other. Cement pastes (w/b=0.4) with and without slag and fly ash cured at two moisture (sealed and saturated) and temperature (20 and 55ºC) conditions were used to investigate the combined impact of SCMs addition and curing on the pore structure of pastes cured up to two years. Also...

  17. High performance concrete with blended cement

    International Nuclear Information System (INIS)

    Biswas, P.P.; Saraswati, S.; Basu, P.C.

    2012-01-01

    Principal objectives of the proposed project are two folds. Firstly, to develop the HPC mix suitable to NPP structures with blended cement, and secondly to study its durability necessary for desired long-term performance. Three grades of concrete to b considered in the proposed projects are M35, M50 and M60 with two types of blended cements, i.e. Portland slag cement (PSC) and Portland pozzolana cement (PPC). Three types of mineral admixtures - silica fume, fly ash and ground granulated blast furnace slag will be used. Concrete mixes with OPc and without any mineral admixture will be considered as reference case. Durability study of these mixes will be carried out

  18. Effects of the super plasticizers and the water/cement ratio on the mini-slump of Portland cement pastes

    International Nuclear Information System (INIS)

    Meirelles, J.R.; Morelli, A.C.; Baldo, J.B.

    1998-01-01

    The rheology of Portland cement concrete is dominated by the cement paste rheology. In general the rheological behavior of cement pastes is evaluated by means of the mini-slump test. In the present paper it was investigated the effect of the water/cement ratio was as of two types of superplasticizers (melamine and naftalen based) on the mini-slump of pastes of common cement pastes. (author)

  19. Mechanical characterization of sisal reinforced cement mortar

    OpenAIRE

    R. Fujiyama; F. Darwish; M.V. Pereira

    2014-01-01

    This work aims at evaluating the mechanical behavior of sisal fiber reinforced cement mortar. The composite material was produced from a mixture of sand, cement, and water. Sisal fibers were added to the mixture in different lengths. Mechanical characterization of both the composite and the plain mortar was carried out using three point bend, compression, and impact tests. Specimens containing notches of different root radii were loaded in three point bending in an effort to determine the eff...

  20. Topics in cement and concrete research

    OpenAIRE

    Brouwers, Jos; Russel, M.I.; Basheer, P.A.M.

    2007-01-01

    The present paper addresses several topics in regard to the sustainable design and use of concrete. First, major features concerning the sustainable aspects of the material concrete are summarised. Then the major constituent, from an environmental point of view, cement is discussed in detail, particularly the hydration and application of slag cement. The intelligent combining of mineral oxides, which are found in clinker, slag, fly ashes etc., is designated as mineral oxide engineering. It re...

  1. WESTERN ALGERIA

    Directory of Open Access Journals (Sweden)

    Mohamed Meddi

    2013-01-01

    Full Text Available Soil erosion by rain and surface runoff is an important problem in the Mediterranean countries. The study of the relationship between erosion and sediment transport with hydrological and climatic factors have b een conducted in many countries around the world. The aim of this work is to show ra infall impact on the variability of spatial and temporal concentration in twelve drainage basins in the west of Algeria. We will also seek to find a representative parameter of rainfall erosive potential on a Time and spatial scale. When studying sediment transport in twelve drainage basins of the Centre and the west of Algeria, we have found that the modified Fournier index Which explains much of the specific degradation comp ared to the Fournier index. The study of the temporal variability of the annual rain fall series, modified Fournier index and concentration of the precipitation in the year for a series from 1930 to 2007 showed a negative trend of the two variables. The a nnual rainfall and modified Fournier index have declined by more than 20%. This de cline is more significant in inland areas.

  2. Study on properties and testing methods of thermo-responsive cementing system for well cementing in heavy oil thermal recovery

    Science.gov (United States)

    Li, Lianjiang

    2017-08-01

    In this paper, thermo-responsive cement slurry system were being developed, the properties of conventional cement slurry, compressive strength high temperature of cement sheath, mechanical properties of cement sheath and thermal properties of cement sheath were being tested. Results were being used and simulated by Well-Life Software, Thermo-responsive cement slurry system can meet the requirements of heavy oil thermal recovery production. Mechanical and thermal properties of thermo-responsive cement sheath were being tested. Tensile fracture energy of the thermo-responsive cement sheath is larger than conventional cement. The heat absorption capacity of conventional cement sheath is larger than that of thermo-responsive cement sheath, this means more heat is needed for the unit mass once increasing 1.0 °C, which also indicates that thermo-responsive cement own good heat insulating and preservation effects. The heat conductivity coefficient and thermal expansion coefficient of thermo-responsive cement is less than and conventional cement, this means that thermo-responsive cement have good heat preservation and insulation effects with good thermal expansion stabilities.

  3. Photoactive glazed polymer-cement composite

    Science.gov (United States)

    Baltes, Liana; Patachia, Silvia; Tierean, Mircea; Ekincioglu, Ozgur; Ozkul, Hulusi M.

    2018-04-01

    Macro defect free cements (MDF), a kind of polymer-cement composites, are characterized by remarkably high mechanical properties. Their flexural strengths are 20-30 times higher than those of conventional cement pastes, nearly equal to that of an ordinary steel. The main drawback of MDF cements is their sensitivity to water. This paper presents a method to both diminish the negative impact of water on MDF cements mechanical properties and to enlarge their application by conferring photoactivity. These tasks were solved by glazing MDF cement with an ecological glaze containing nano-particles of TiO2. Efficiency of photocatalytic activity of this material was tested against methylene blue aqueous solution (4.4 mg/L). Influence of the photocatalyst concentration in the glaze paste and of the contact time on the photocatalysis process (efficiency and kinetic) was studied. The best obtained photocatalysis yield was of 97.35%, after 8 h of exposure to 254 nm UV radiation when used an MDF glazed with 10% TiO2 in the enamel paste. Surface of glazed material was characterized by optic microscopy, scratch test, SEM, XRD, and EDS. All these properties were correlated with the aesthetic aspect of the glazed surface aiming to propose using of this material for sustainable construction development.

  4. Pre-cementation of deep shaft

    Science.gov (United States)

    Heinz, W. F.

    1988-12-01

    Pre-cementation or pre-grouting of deep shafts in South Africa is an established technique to improve safety and reduce water ingress during shaft sinking. The recent completion of several pre-cementation projects for shafts deeper than 1000m has once again highlighted the effectiveness of pre-grouting of shafts utilizing deep slimline boreholes and incorporating wireline technique for drilling and conventional deep borehole grouting techniques for pre-cementation. Pre-cementation of deep shaft will: (i) Increase the safety of shaft sinking operation (ii) Minimize water and gas inflow during shaft sinking (iii) Minimize the time lost due to additional grouting operations during sinking of the shaft and hence minimize costly delays and standing time of shaft sinking crews and equipment. (iv) Provide detailed information of the geology of the proposed shaft site. Informations on anomalies, dykes, faults as well as reef (gold bearing conglomerates) intersections can be obtained from the evaluation of cores of the pre-cementation boreholes. (v) Provide improved rock strength for excavations in the immediate vicinity of the shaft area. The paper describes pre-cementation techniques recently applied successfully from surface and some conclusions drawn for further considerations.

  5. Analysis of rheological properties of bone cements.

    Science.gov (United States)

    Nicholas, M K D; Waters, M G J; Holford, K M; Adusei, G

    2007-07-01

    The rheological properties of three commercially available bone cements, CMW 1, Palacos R and Cemex ISOPLASTIC, were investigated. Testing was undertaken at both 25 and 37 degrees C using an oscillating parallel plate rheometer. Results showed that the three high viscosity cements exhibited distinct differences in curing rate, with CMW 1 curing in 8.7 min, Palacos R and Cemex ISOPLASTIC in 13 min at 25 degrees C. Furthermore it was found that these curing rates were strongly temperature dependent, with curing rates being halved at 37 degrees C. By monitoring the change of viscosity with time over the entire curing process, the results showed that these cements had differing viscosity profiles and hence exhibit very different handling characteristics. However, all the cements reached the same maximum viscosity of 75 x 10(3) Pa s. Also, the change in elastic/viscous moduli and tan delta with time, show the cements changing from a viscous material to an elastic solid with a clear peak in the viscous modulus during the latter stages of curing. These results give valuable information about the changes in rheological properties for each commercial bone cement, especially during the final curing process.

  6. Development of a biodegradable bone cement

    International Nuclear Information System (INIS)

    Yusof Abdullah; Nurhaslinda Ee Abdullah; Wee Pee Chai; Norita Mohd Zain

    2002-01-01

    Biodegradable bone cement is a newly developed bone repair material, which is able to give immediate support to the implant area, and does not obstruct the bone repairing and regeneration process through appropriate biodegradation rate, which is synchronized with the mechanical load it should bear. The purpose of this study is to locally produce biodegradable bone cement using HA as absorbable filler. The cement is composed of an absorbable filler and unsaturated polyester for 100% degradation. Cross-linking effect is achieved through the action of poly (vinyl pyrrol lidone) (PVP) and an initiator. On the other hand, PPF was synthesized using direct esterification method. Characteristics of the bone cement were studied; these included the curing time, cross-linking effect and curing temperature. The products were characterized using X-Ray diffraction (XRD) to perform phase analysis and Scanning Electrons Microscopes to determine the morphology. The physical and mechanical properties of the bone cement were also investigated. The biocompatibility of the bone cement was tested using simulated body physiological solution. (Author)

  7. Evaluation of the amount of excess cement around the margins of cement-retained dental implant restorations: the effect of the cement application method.

    Science.gov (United States)

    Chee, Winston W L; Duncan, Jesse; Afshar, Manijeh; Moshaverinia, Alireza

    2013-04-01

    Complete removal of excess cement from subgingival margins after cementation of implant-supported restorations has been shown to be unpredictable. Remaining cement has been shown to be associated with periimplant inflammation and bleeding. The purpose of this study was to investigate and compare the amount of excess cement after cementation with 4 different methods of cement application for cement-retained implant-supported restorations. Ten implant replicas/abutments (3i) were embedded in acrylic resin blocks. Forty complete veneer crowns (CVCs) were fabricated by waxing onto the corresponding plastic waxing sleeves. The wax patterns were cast and the crowns were cemented to the implant replicas with either an interim (Temp Bond) or a definitive luting agent (FujiCEM). Four methods of cement application were used for cementation: Group IM-Cement applied on the internal marginal area of the crown only; Group AH-Cement applied on the apical half of the axial walls of the crown; Group AA-Cement applied to all axial walls of the interior surface of the crown, excluding the occlusal surface; and Group PI-Crown filled with cement then seated on a putty index formed to the internal configuration of the restoration (cementation device) (n=10). Cement on the external surfaces was removed before seating the restoration. Cement layers were applied on each crown, after which the crown was seated under constant load (80 N) for 10 minutes. The excess cement from each specimen was collected and measured. One operator performed all the procedures. Results for the groups were compared, with 1 and 2-way ANOVA and the Tukey multiple range test (α=.05). No significant difference in the amount of excess/used cement was observed between the 2 different types of cements (P=.1). Group PI showed the least amount of excess cement in comparison to other test groups (P=.031). No significant difference was found in the amount of excess cement among groups MI, AH, and AA. Group AA showed the

  8. Cement Types, Composition, Uses and Advantages of Nanocement, Environmental Impact on Cement Production, and Possible Solutions

    Directory of Open Access Journals (Sweden)

    S. P. Dunuweera

    2018-01-01

    Full Text Available We first discuss cement production and special nomenclature used by cement industrialists in expressing the composition of their cement products. We reveal different types of cement products, their compositions, properties, and typical uses. Wherever possible, we tend to give reasons as to why a particular cement type is more suitable for a given purpose than other types. Cement manufacturing processes are associated with emissions of large quantities of greenhouse gases and environmental pollutants. We give below quantitative and qualitative analyses of environmental impact of cement manufacturing. Controlling pollution is a mandatory legal and social requirement pertinent to any industry. As cement industry is one of the biggest CO2 emitters, it is appropriate to discuss different ways and means of CO2 capture, which will be done next. Finally, we give an account of production of nanocement and advantages associated with nanocement. Nanofillers such as nanotitania, nanosilica, and nanoalumina can be produced in large industrial scale via top-down approach of reducing size of naturally available bulk raw materials to those in the nanorange of 1 nm–100 nm. We mention the preparation of nanotitania and nanosilica from Sri Lankan mineral sands and quartz deposits, respectively, for the use as additives in cement products to improve performance and reduce the amount and cost of cement production and consequent environmental impacts. As of now, mineral sands and other treasures of minerals are exported without much value addition. Simple chemical modifications or physical treatments would add enormous value to these natural materials. Sri Lanka is gifted with highly pure quartz and graphite from which silica and graphite nanoparticles, respectively, can be prepared by simple size reduction processes. These can be used as additives in cements. Separation of constituents of mineral sands is already an ongoing process.

  9. In vitro tensile strength of luting cements on metallic substrate.

    Science.gov (United States)

    Orsi, Iara A; Varoli, Fernando K; Pieroni, Carlos H P; Ferreira, Marly C C G; Borie, Eduardo

    2014-01-01

    The aim of this study was to determine the tensile strength of crowns cemented on metallic substrate with four different types of luting agents. Twenty human maxillary molars with similar diameters were selected and prepared to receive metallic core castings (Cu-Al). After cementation and preparation the cores were measured and the area of crown's portion was calculated. The teeth were divided into four groups based on the luting agent used to cement the crowns: zinc phosphate cement; glass ionomer cement; resin cement Rely X; and resin cement Panavia F. The teeth with the crowns cemented were subjected to thermocycling and later to the tensile strength test using universal testing machine with a load cell of 200 kgf and a crosshead speed of 0.5 mm/min. The load required to dislodge the crowns was recorded and converted to MPa/mm(2). Data were subjected to Kruskal-Wallis analysis with a significance level of 1%. Panavia F showed significantly higher retention in core casts (3.067 MPa/mm(2)), when compared with the other cements. Rely X showed a mean retention value of 1.877 MPa/mm(2) and the zinc phosphate cement with 1.155 MPa/mm(2). Glass ionomer cement (0.884 MPa/mm(2)) exhibited the lowest tensile strength value. Crowns cemented with Panavia F on cast metallic posts and cores presented higher tensile strength. The glass ionomer cement showed the lowest tensile strength among all the cements studied.

  10. Study on Cr(VI) Leaching from Cement and Cement Composites

    Science.gov (United States)

    Palascakova, Lenka; Kanuchova, Maria

    2018-01-01

    This paper reports an experimental study on hexavalent chromium leaching from cement samples and cement composites containing silica fume and zeolite additions that were subjected to various leaching agents. The water-soluble Cr(VI) concentrations in cements ranged from 0.2 to 3.2 mg/kg and represented only 1.8% of the total chromium content. The presence of chromium compounds with both chromium oxidation states of III and VI was detected in the cement samples by X-ray photoelectron spectroscopy (XPS). Leaching tests were performed in a Britton-Robinson buffer to simulate natural conditions and showed increased dissolution of Cr(VI) up to 6 mg/kg. The highest amount of leached hexavalent chromium was detected after leaching in HCl. The findings revealed that the leaching of chromium from cements was higher by 55–80% than that from the cement composites. A minimum concentration was observed for all cement samples when studying the relationship between the soluble Cr(VI) and the cement storage time. PMID:29690550

  11. Sulphur cement pre-composition and process for preparing such sulphur cement pre-composition

    NARCIS (Netherlands)

    2013-01-01

    The invention provides a process for the preparation of a sulphur cement pre-composition comprising reacting sulphur modifier with polysulphide-containing organosilane to obtain in the presence of sulphur the sulphur cement pre-composition, wherein the organosilane has the general molecular formula:

  12. Characterization of cement minerals, cements and their reaction products at the atomic and nano scale

    DEFF Research Database (Denmark)

    Skibsted, Jørgen; Hall, Christopher

    2008-01-01

    Recent advances and highlights in characterization methods are reviewed for cement minerals, cements and their reaction products. The emphasis is on X-ray and neutron diffraction, and on nuclear magnetic resonance methods, although X-ray absorption and Raman spectroscopies are discussed briefly...

  13. Ceramic residue for producing cements, method for the production thereof, and cements containing same

    OpenAIRE

    Sánchez de Rojas, María Isabel; Frías, Moisés; Asensio, Eloy; Medina Martínez, César

    2014-01-01

    [EN] The invention relates to a ceramic residue produced from construction and demolition residues, as a puzzolanic component of cements. The invention also relates to a method for producing said ceramic residues and to another method of producing cements using said residues. This type of residue is collected in recycling plants, where it is managed. This invention facilitates a potential commercial launch.

  14. Analysis of CCRL proficiency cements 151 and 152 using the Virtual Cement and Concrete Testing Laboratory

    International Nuclear Information System (INIS)

    Bullard, Jeffrey W.; Stutzman, Paul E.

    2006-01-01

    To test the ability of the Virtual Cement and Concrete Testing Laboratory (VCCTL) software to predict cement hydration properties, characterization of mineralogy and phase distribution is necessary. Compositional and textural characteristics of Cement and Concrete Reference Laboratory (CCRL) cements 151 and 152 were determined via scanning electron microscopy (SEM) analysis followed by computer modeling of hydration properties. The general procedure to evaluate a cement is as follows: (1) two-dimensional SEM backscattered electron and X-ray microanalysis images of the cement are obtained, along with a measured particle size distribution (PSD); (2) based on analysis of these images and the measured PSD, three-dimensional microstructures of various water-to-cement ratios are created and hydrated using VCCTL, and (3) the model predictions for degree of hydration under saturated conditions, heat of hydration (ASTM C186), setting time (ASTM C191), and strength development of mortar cubes (ASTM C109) are compared to experimental measurements either performed at NIST or at the participating CCRL proficiency sample evaluation laboratories. For both cements, generally good agreement is observed between the model predictions and the experimental data

  15. The effect of sand/cement ratio on radon exhalation from cement specimens containing 226Ra

    International Nuclear Information System (INIS)

    Takriti, S.; Shweikani, R.; Ali, A. F.; Rajaa, G.

    2002-09-01

    Portland cement was mixed with different kind of sand (calcite and silica) in different ratio to produce radioactive specimens with radium chloride. The release of radon from these samples was studied. The results showed that radon release from the calcite-cement samples increased with the increases of the sand mixed ratio until fixed value (about 20%) then decreased to less than its release from the beginning, and the release changed with the sand size also. Radon release from silica-cement samples had the same observations of calcite-cement samples. It was found that calcite-cement reduced the radon exhalation quantity rather than the silica-cement samples. The decreases of the radon exhalation from the cement-sand may be due to the creation of free spaces in the samples, which gave the possibility to radon to decay into these free spaces rather than radon exhalation. The daughters of the radon decay 214 Bi and 214 Pb reported by gamma measurements of the cement-sand samples. (author)

  16. Characterization of cement minerals, cements and their reaction products at the atomic and nano scale

    International Nuclear Information System (INIS)

    Skibsted, Jorgen; Hall, Christopher

    2008-01-01

    Recent advances and highlights in characterization methods are reviewed for cement minerals, cements and their reaction products. The emphasis is on X-ray and neutron diffraction, and on nuclear magnetic resonance methods, although X-ray absorption and Raman spectroscopies are discussed briefly

  17. Glass ionomer cement: literature review

    Directory of Open Access Journals (Sweden)

    Sérgio Spezzia

    2017-12-01

    Full Text Available Introduction: In the dental area preventive actions occur in an attempt to avoid the installation of caries, a disease that has an increased prevalence in the population and which is a Public Health problem. Some resources are used for such, such as: performing early diagnosis and the option for conservative treatments of minimal intervention. The glass ionomer cement (CIV, coming from its beneficial characteristics that meet current trends, is closely related to the precepts of Preventive and Minimally Invasive Dentistry and the new preservative techniques recommended. Objective: The objective of the present article was to carry out a literature review study, to determine the characteristics of CIV that has a prominent role in the Minimally Invasive Dentistry profile. Results: The dentist surgeon must be aware of the classification, according to its composition and physical-chemical nature: conventional ionomers; ionomers reinforced by metals; high viscosity and various types of resin modified glass ionomers to correctly choose the CIV that will be used in their clinical interventions, which should occur based on the properties of the material and its clinical indication. Conclusion: It was concluded that the implementation of preventive techniques with CIV in public health care, tend to minimize curative treatments, concurrently valuing the low complexity dental procedures performed in Primary Care, avoiding referrals for treatment of cases of greater complexity at the level Secondary and tertiary care, saving resources.

  18. Alternative Fuel for Portland Cement Processing

    Energy Technology Data Exchange (ETDEWEB)

    Schindler, Anton K; Duke, Steve R; Burch, Thomas E; Davis, Edward W; Zee, Ralph H; Bransby, David I; Hopkins, Carla; Thompson, Rutherford L; Duan, Jingran; ; Venkatasubramanian, Vignesh; Stephen, Giles

    2012-06-30

    The production of cement involves a combination of numerous raw materials, strictly monitored system processes, and temperatures on the order of 1500 °C. Immense quantities of fuel are required for the production of cement. Traditionally, energy from fossil fuels was solely relied upon for the production of cement. The overarching project objective is to evaluate the use of alternative fuels to lessen the dependence on non-renewable resources to produce portland cement. The key objective of using alternative fuels is to continue to produce high-quality cement while decreasing the use of non-renewable fuels and minimizing the impact on the environment. Burn characteristics and thermodynamic parameters were evaluated with a laboratory burn simulator under conditions that mimic those in the preheater where the fuels are brought into a cement plant. A drop-tube furnace and visualization method were developed that show potential for evaluating time- and space-resolved temperature distributions for fuel solid particles and liquid droplets undergoing combustion in various combustion atmospheres. Downdraft gasification has been explored as a means to extract chemical energy from poultry litter while limiting the throughput of potentially deleterious components with regards to use in firing a cement kiln. Results have shown that the clinkering is temperature independent, at least within the controllable temperature range. Limestone also had only a slight effect on the fusion when used to coat the pellets. However, limestone addition did display some promise in regards to chlorine capture, as ash analyses showed chlorine concentrations of more than four times greater in the limestone infused ash as compared to raw poultry litter. A reliable and convenient sampling procedure was developed to estimate the combustion quality of broiler litter that is the best compromise between convenience and reliability by means of statistical analysis. Multi-day trial burns were conducted

  19. Cement for oil well developed from ordinary cement: characterization physical, chemical and mineralogical

    International Nuclear Information System (INIS)

    Oliveira, D.N.S.; Neves, G. de A.; Chaves, A.C.; Mendonca, A.M.G.D.; Lima, M.S. de; Bezerra, U.T.

    2012-01-01

    This work aims to characterize a new type of cement produced from the mixture of ordinary Portland cement, which can be used as an option in the cementing of oil wells. To enable this work we used the method of lineal programming for the new cement composition, then conducted tests to characterize through particle size analysis by laser diffraction, chemical analysis by EDX, TGA, X-ray diffraction, time grip, resistance to compression. The overall result showed that the new cement had made low-C3A, takes more time to the CPP, thermal stability up to 500 ° C, the kinetics of hydration and low levels of major components consistent with the specifications of ABNT. (author)

  20. Effect of Cement Type on Autogenous Deformation of Cement-Based Materials

    DEFF Research Database (Denmark)

    Pietro, Lura; Ye, Guang; van Breugel, Klaas

    2004-01-01

    In this paper, measurements of non-evaporable water content, chemical shrinkage, autogenous deformation, internal relative humidity (RH), pore solution composition, and early-age elastic modulus are presented and discussed. All experiments were performed on Portland cement and blast-furnace slag...... (BFS) cement pastes. Self-desiccation shrinkage of the BFS cement paste was modeled based on the RH measurements, following the capillary-tension approach. The main findings of this study are: 1) self-desiccation shrinkage can be related to self-desiccation both for Portland and for BFS cement pastes......, taking into account the influence of the dissolved salts in the pore solution, 2) the BFS cement paste studied shows pronounced self-desiccation and self-desiccation shrinkage, mainly caused by its very fine pore structure....

  1. Petroleum Sludge as gypsum replacement in cement plants: Its Impact on Cement Strength

    Science.gov (United States)

    Benlamoudi, Ali; Kadir, Aeslina Abdul; Khodja, Mohamed

    2017-08-01

    Due to high cost of cement manufacturing and the huge amount of resources exhaustion, companies are trying to incorporate alternative raw materials or by-products into cement production so as to produce alternative sustainable cement. Petroleum sludge is a dangerous waste that poses serious imparts on soil and groundwater. Given that this sludge contains a high percentage of anhydrite (CaSO4), which is the main component of gypsum (CaSO4.2H2O), it may play the same gypsum role in strength development. In this research, a total replacement of gypsum (100%) has been substituted by petroleum sludge in cement production and has led to an increase of 28.8% in UCS values after 28 curing days. Nevertheless, the burning of this waste has emitted a considerable amount of carbon monoxide (CO) gas that needs to be carefully considered prior to use petroleum sludge within cement plants.

  2. Comparative study on strength properties of cement mortar by partial replacement of cement with ceramic powder and silica fume

    Science.gov (United States)

    Himabindu, Ch.; Geethasri, Ch.; Hari, N.

    2018-05-01

    Cement mortar is a mixture of cement and sand. Usage of high amount of cement increases the consumption of natural resources and electric power. To overcome this problem we need to replace cement with some other material. Cement is replaced with many other materials like ceramic powder, silica fume, fly ash, granulated blast furnace slag, metakaolin etc.. In this research cement is replaced with ceramic powder and silica fume. Different combinations of ceramic powder and silica fume in cement were replaced. Cement mortar cubes of 1:3 grade were prepared. These cubes were cured under normal water for 7 days, 14days and 28 days. Compressive strength test was conducted for all mixes of cement mortar cubes.

  3. Chromium content in human skin after in vitro application of ordinary cement and ferrous-sulphate-reduced cement

    DEFF Research Database (Denmark)

    Fullerton, A; Gammelgaard, Bente; Avnstorp, C

    1993-01-01

    The amount of chromium found in human skin after in vitro application of cement suspensions on full-thickness human skin in diffusion cells was investigated. Cement suspensions made from ordinary Portland cement or Portland cement with the chromate reduced with added ferrous sulphate were used....... The cement suspensions were either applied on the skin surface under occlusion for 48 h or applied repeatedly every 24 h for 96 h. No statistically significant difference in chromium content of skin layers between skin exposed to ordinary Portland cement, skin exposed to cement with added ferrous sulphate...... and unexposed skin was observed, despite a more permeable skin barrier at the alkaline pH of the cement suspensions, i.e., pH 12.5. Increased chromium levels in epidermis and dermis were seen when ordinary Portland cement was applied as a suspension with added sodium sulphate (20%) on the skin surface for 96 h...

  4. Immobilization of radioactive waste in cement based matrices

    International Nuclear Information System (INIS)

    Glasser, F.P.; Rahman, A.A.; Macphee, S.; Atkins, M.; Beckley, N.; Carson, S.

    1986-11-01

    Experimental and theoretical studies of hydrated cement systems are described. The behaviour of slag-based cement is described with a view to predicting their long term pH, Esub(n) and mineralogical balance. Modelling studies which enable the prediction at long ages of cement composites are advanced and a base model of the CaO-SiO 2 -H 2 O system presented. The behaviour of U and I in cements is explored. The tolerance of cement systems for a wide range of miscellaneous waste stream components and environmental hazards is described. The redox potential in cements is effectively lowered by irradiation. (author)

  5. Colorectal cancer and non-malignant respiratory disease in asbestos cement and cement workers

    International Nuclear Information System (INIS)

    Jacobsson, K.

    1993-09-01

    Radiologically visible parenchymal changes (small opacities >= 1/0;ILO 1980 classification) were present in 20% of a sample of workers (N=174), employed for 20 years (median) in an asbestos cement plant. Exposure-response relationships were found, after controlling for age and smoking habits. In a sample of asbestos cement workers with symptoms and signs suggestive of pulmonary disease (N=33), increased lung density measured by x-ray computed tomography, and reduced static lung volumes and lung compliance was found. In a cohort of asbestos cement workers (N=1.929) with an estimated median exposure of 1.2 fibres/ml, the mortality from non-malignant respiratory disease was increased in comparison to a regional reference cohort (N=1.233). A two-to three-fold increase of non-malignant respiratory mortality was noted among workers employed for more than a decade in the asbestos cement plant, compared to cement workers (N=1.526), who in their turn did not experience and increased risk compared to the general population. In the cohorts of asbestos cement and cement workers, there was a tow-to three-fold increased incidence of cancer in the right part of the colon, compared to the general population as well as to external reference cohorts of other industrial workers (N=3.965) and fishermen (N=8.092). A causal relation with the exposure to mineral dust and fibres was supported by the findings of higher risk estimated in subgroups with high cumulated asbestos doses or longer duration of cement work. The incidence of cancer in the left part of the colon was not increased. Morbidity data, but not mortality data, disclosed the subsite-specific risk pattern. Both asbestos cement workers and cement workers has an increased incidence of rectal cancer, compared with the general population, and with the fishermen. The risk was, however, of the same magnitude among the other industrial workers. 181 refs

  6. Experimental Study on Artificial Cemented Sand Prepared with Ordinary Portland Cement with Different Contents

    Directory of Open Access Journals (Sweden)

    Dongliang Li

    2015-07-01

    Full Text Available Artificial cemented sand test samples were prepared by using ordinary Portland cement (OPC as the cementing agent. Through uniaxial compression tests and consolidated drained triaxial compression tests, the stress-strain curves of the artificial cemented sand with different cementing agent contents (0.01, 0.03, 0.05 and 0.08 under various confining pressures (0.00 MPa, 0.25 MPa, 0.50 MPa and 1.00 MPa were obtained. Based on the test results, the effect of the cementing agent content (Cv on the physical and mechanical properties of the artificial cemented sand were analyzed and the Mohr-Coulomb strength theory was modified by using Cv. The research reveals that when Cv is high (e.g., Cv = 0.03, 0.05 or 0.08, the stress-strain curves of the samples indicate a strain softening behavior; under the same confining pressure, as Cv increases, both the peak strength and residual strength of the samples show a significant increase. When Cv is low (e.g., Cv = 0.01, the stress-strain curves of the samples indicate strain hardening behavior. From the test data, a function of Cv (the cementing agent content with c′ (the cohesion force of the sample and Δϕ′ (the increment of the angle of shearing resistance is obtained. Furthermore, through modification of the Mohr-Coulomb strength theory, the effect of cementing agent content on the strength of the cemented sand is demonstrated.

  7. Experimental Study on Artificial Cemented Sand Prepared with Ordinary Portland Cement with Different Contents.

    Science.gov (United States)

    Li, Dongliang; Liu, Xinrong; Liu, Xianshan

    2015-07-02

    Artificial cemented sand test samples were prepared by using ordinary Portland cement (OPC) as the cementing agent. Through uniaxial compression tests and consolidated drained triaxial compression tests, the stress-strain curves of the artificial cemented sand with different cementing agent contents (0.01, 0.03, 0.05 and 0.08) under various confining pressures (0.00 MPa, 0.25 MPa, 0.50 MPa and 1.00 MPa) were obtained. Based on the test results, the effect of the cementing agent content ( C v ) on the physical and mechanical properties of the artificial cemented sand were analyzed and the Mohr-Coulomb strength theory was modified by using C v . The research reveals that when C v is high (e.g., C v = 0.03, 0.05 or 0.08), the stress-strain curves of the samples indicate a strain softening behavior; under the same confining pressure, as C v increases, both the peak strength and residual strength of the samples show a significant increase. When C v is low (e.g., C v = 0.01), the stress-strain curves of the samples indicate strain hardening behavior. From the test data, a function of C v (the cementing agent content) with c ' (the cohesion force of the sample) and Δϕ' (the increment of the angle of shearing resistance) is obtained. Furthermore, through modification of the Mohr-Coulomb strength theory, the effect of cementing agent content on the strength of the cemented sand is demonstrated.

  8. Push-out bond strengths of different dental cements used to cement glass fiber posts.

    Science.gov (United States)

    Pereira, Jefferson Ricardo; Lins do Valle, Accácio; Ghizoni, Janaina Salomon; Lorenzoni, Fábio César; Ramos, Marcelo Barbosa; Barbosa, Marcelo Ramos; Dos Reis Só, Marcus Vinícius

    2013-08-01

    Since the introduction of glass fiber posts, irreversible vertical root fractures have become a rare occurrence; however, adhesive failure has become the primary failure mode. The purpose of this study was to evaluate the push-out bond strength of glass fiber posts cemented with different luting agents on 3 segments of the root. Eighty human maxillary canines with similar root lengths were randomly divided into 8 groups (n=10) according to the cement assessed (Rely X luting, Luting and Lining, Ketac Cem, Rely X ARC, Biscem, Duo-link, Rely X U100, and Variolink II). After standardized post space preparation, the root dentin was pretreated for dual-polymerizing resin cements and untreated for the other cements. The mixed luting cement paste was inserted into post spaces with a spiral file and applied to the post surface that was seated into the canal. After 7 days, the teeth were sectioned perpendicular to their long axis into 1-mm-thick sections. The push-out test was performed at a speed of 0.5 mm/min until extrusion of the post occurred. The results were evaluated by 2-way ANOVA and the all pairwise multiple comparison procedures (Tukey test) (α=.05). ANOVA showed that the type of interaction between cement and root location significantly influenced the push-out strength (Pcements and glass ionomer cements showed significantly higher values compared to dual-polymerizing resin cements. In all root segments, dual-polymerizing resin cements provided significantly lower bond strength. Significant differences among root segments were found only for Duo-link cement. Copyright © 2013 The Editorial Council of the Journal of Prosthetic Dentistry. Published by Mosby, Inc. All rights reserved.

  9. The differences between soil grouting with cement slurry and cement-water glass slurry

    Science.gov (United States)

    Zhu, Mingting; Sui, Haitong; Yang, Honglu

    2018-01-01

    Cement slurry and cement-water glass slurry are the most widely applied for soil grouting reinforcement project. The viscosity change of cement slurry is negligible during grouting period and presumed to be time-independent while the viscosity of cement-water glass slurry increases with time quickly and is presumed to be time-dependent. Due to the significantly rheology differences between them, the grouting quality and the increasing characteristics of grouting parameters may be different, such as grouting pressure, grouting surrounding rock pressure, i.e., the change of surrounding rock pressure deduced by grouting pressure. Those are main factors for grouting design. In this paper, a large-scale 3D grouting simulation device was developed to simulate the surrounding curtain grouting for a tunnel. Two series of surrounding curtain grouting experiments under different geo-stress of 100 kPa, 150 kPa and 200 kPa were performed. The overload test on tunnel was performed to evaluate grouting effect of all surrounding curtain grouting experiments. In the present results, before 240 seconds, the grouting pressure increases slowly for both slurries; after 240 seconds the increase rate of grouting pressure for cement-water glass slurry increases quickly while that for cement slurry remains roughly constant. The increasing trend of grouting pressure for cement-water glass is similar to its viscosity. The setting time of cement-water glass slurry obtained from laboratory test is less than that in practical grouting where grout slurry solidifies in soil. The grouting effect of cement-water glass slurry is better than that of cement slurry and the grouting quality decreases with initial pressure.

  10. Cement replacement by sugar cane bagasse ash: CO2 emissions reduction and potential for carbon credits.

    Science.gov (United States)

    Fairbairn, Eduardo M R; Americano, Branca B; Cordeiro, Guilherme C; Paula, Thiago P; Toledo Filho, Romildo D; Silvoso, Marcos M

    2010-09-01

    This paper presents a study of cement replacement by sugar cane bagasse ash (SCBA) in industrial scale aiming to reduce the CO(2) emissions into the atmosphere. SCBA is a by-product of the sugar/ethanol agro-industry abundantly available in some regions of the world and has cementitious properties indicating that it can be used together with cement. Recent comprehensive research developed at the Federal University of Rio de Janeiro/Brazil has demonstrated that SCBA maintains, or even improves, the mechanical and durability properties of cement-based materials such as mortars and concretes. Brazil is the world's largest sugar cane producer and being a developing country can claim carbon credits. A simulation was carried out to estimate the potential of CO(2) emission reductions and the viability to issue certified emission reduction (CER) credits. The simulation was developed within the framework of the methodology established by the United Nations Framework Convention on Climate Change (UNFCCC) for the Clean Development Mechanism (CDM). The State of São Paulo (Brazil) was chosen for this case study because it concentrates about 60% of the national sugar cane and ash production together with an important concentration of cement factories. Since one of the key variables to estimate the CO(2) emissions is the average distance between sugar cane/ethanol factories and the cement plants, a genetic algorithm was developed to solve this optimization problem. The results indicated that SCBA blended cement reduces CO(2) emissions, which qualifies this product for CDM projects. 2010 Elsevier Ltd. All rights reserved.

  11. Properties of Non-Structural Concrete Made with Mixed Recycled Aggregates and Low Cement Content.

    Science.gov (United States)

    López-Uceda, Antonio; Ayuso, Jesús; López, Martin; Jimenez, José Ramón; Agrela, Francisco; Sierra, María José

    2016-01-26

    In spite of not being legally accepted in most countries, mixed recycled aggregates (MRA) could be a suitable raw material for concrete manufacturing. The aims of this research were as follows: (i) to analyze the effect of the replacement ratio of natural coarse aggregates with MRA, the amount of ceramic particles in MRA, and the amount of cement, on the mechanical and physical properties of a non-structural concrete made with a low cement content; and (ii) to verify if it is possible to achieve a low-strength concrete that replaces a greater amount of natural aggregate with MRA and that has a low cement content. Two series of concrete mixes were manufactured using 180 and 200 kg/m³ of CEM II/A-V 42.5 R type Portland cement. Each series included seven concrete mixes: one with natural aggregates; two MRA with different ceramic particle contents; and one for each coarse aggregate replacement ratio (20%, 40%, and 100%). To study their properties, compressive and splitting tensile strength, modulus of elasticity, density, porosity, water penetration, and sorptivity, tests were performed. The results confirmed that the main factors affecting the properties analyzed in this research are the amount of cement and the replacement ratio; the two MRAs used in this work presented a similar influence on the properties. A non-structural, low-strength concrete (15 MPa) with an MRA replacement ratio of up to 100% for 200 kg/m³ of cement was obtained. This type of concrete could be applied in the construction of ditches, sidewalks, and other similar civil works.

  12. CEMENT TRANSPORTATION LIMITED-FLEET MODELING AND ASSIGNING TO RATED DEMANDS

    Directory of Open Access Journals (Sweden)

    Narjes MASHHADI BANDANI

    2017-04-01

    Full Text Available Transportation is an inseparable part of the supply chain, with a key role in product distribution. This role is highlighted when ratio of “the cost of transportation” to “the value of goods” such as cement is significant. Iran has recently become one of the main centers of cement production in the world. However, transportation is the most important challenge in cement distribution because of weak structure of the transportation fleet and its independent action. Independence of and lack of commitment on the part of transportation fleets to cement companies as well as lack of timely delivery due to shortage of transportation in some routes and seasons lead to customers` dissatisfaction and even market loss or lack of market development. One of the significant differences between the transportation system in Iran and that in developed countries is lack of complete productivity of the transportation fleet. It means that trucks are driver-based in Iran. This paper introduces a model considering some issues such as driver-based trucks, size of the transportation fleet based on the number of active trucks, and demand priorities in the cement company. Taking the relation between the number of active trucks and the cement company into account, this model assigns weekly demands to the transportation fleet. It also tries to minimize the delay to respond to demands and increases the efficiency of the transportation fleet. Finally, this current condition-based model is compared with two other models including “no constraints on different routes of trucks” as well as single-route model for trucks.

  13. Properties of Non-Structural Concrete Made with Mixed Recycled Aggregates and Low Cement Content

    Science.gov (United States)

    López-Uceda, Antonio; Ayuso, Jesús; López, Martin; Jimenez, José Ramón; Agrela, Francisco; Sierra, María José

    2016-01-01

    In spite of not being legally accepted in most countries, mixed recycled aggregates (MRA) could be a suitable raw material for concrete manufacturing. The aims of this research were as follows: (i) to analyze the effect of the replacement ratio of natural coarse aggregates with MRA, the amount of ceramic particles in MRA, and the amount of cement, on the mechanical and physical properties of a non-structural concrete made with a low cement content; and (ii) to verify if it is possible to achieve a low-strength concrete that replaces a greater amount of natural aggregate with MRA and that has a low cement content. Two series of concrete mixes were manufactured using 180 and 200 kg/m3 of CEM II/A-V 42.5 R type Portland cement. Each series included seven concrete mixes: one with natural aggregates; two MRA with different ceramic particle contents; and one for each coarse aggregate replacement ratio (20%, 40%, and 100%). To study their properties, compressive and splitting tensile strength, modulus of elasticity, density, porosity, water penetration, and sorptivity, tests were performed. The results confirmed that the main factors affecting the properties analyzed in this research are the amount of cement and the replacement ratio; the two MRAs used in this work presented a similar influence on the properties. A non-structural, low-strength concrete (15 MPa) with an MRA replacement ratio of up to 100% for 200 kg/m3 of cement was obtained. This type of concrete could be applied in the construction of ditches, sidewalks, and other similar civil works. PMID:28787874

  14. Concrete and cement composites used for radioactive waste deposition.

    Science.gov (United States)

    Koťátková, Jaroslava; Zatloukal, Jan; Reiterman, Pavel; Kolář, Karel

    2017-11-01

    This review article presents the current state-of-knowledge of the use of cementitious materials for radioactive waste disposal. An overview of radwaste management processes with respect to the classification of the waste type is given. The application of cementitious materials for waste disposal is divided into two main lines: i) as a matrix for direct immobilization of treated waste form; and ii) as an engineered barrier of secondary protection in the form of concrete or grout. In the first part the immobilization mechanisms of the waste by cement hydration products is briefly described and an up-to date knowledge about the performance of different cementitious materials is given, including both traditional cements and alternative binder systems. The advantages, disadvantages as well as gaps in the base of information in relation to individual materials are stated. The following part of the article is aimed at description of multi-barrier systems for intermediate level waste repositories. It provides examples of proposed concepts by countries with advanced waste management programmes. In the paper summary, the good knowledge of the material durability due to its vast experience from civil engineering is highlighted however with the urge for specific approach during design and construction of a repository in terms of stringent safety requirements. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Effect of wet curing duration on durability parameters of hydraulic cement concretes.

    Science.gov (United States)

    2010-01-01

    Hydraulic cement concrete slabs were cast and stored outdoors in Charlottesville, Virginia, to study the impact of wet curing duration on durability parameters. Concrete mixtures were produced using portland cement, portland cement with slag cement, ...

  16. Influence of temporary cement contamination on the surface free energy and dentine bond strength of self-adhesive cements.

    Science.gov (United States)

    Takimoto, Masayuki; Ishii, Ryo; Iino, Masayoshi; Shimizu, Yusuke; Tsujimoto, Akimasa; Takamizawa, Toshiki; Ando, Susumu; Miyazaki, Masashi

    2012-02-01

    The surface free energy and dentine bond strength of self-adhesive cements were examined after the removal of temporary cements. The labial dentine surfaces of bovine mandibular incisors were wet ground with #600-grit SiC paper. Acrylic resin blocks were luted to the prepared dentine surfaces using HY Bond Temporary Cement Hard (HY), IP Temp Cement (IP), Fuji TEMP (FT) or Freegenol Temporary Cement (TC), and stored for 1 week. After removal of the temporary cements with an ultrasonic tip, the contact angle values of five specimens per test group were determined for the three test liquids, and the surface-energy parameters of the dentine surfaces were calculated. The dentine bond strengths of the self-adhesive cements were measured after removal of the temporary cements in a shear mode at a crosshead speed of 1.0mm/min. The data were subjected to one-way analysis of variance (ANOVA) followed by Tukey's HSD test. For all surfaces, the value of the estimated surface tension component γ(S)(d) (dispersion) was relatively constant at 41.7-43.3 mJm(-2). After removal of the temporary cements, the value of the γ(S)(h) (hydrogen-bonding) component decreased, particularly with FT and TC. The dentine bond strength of the self-adhesive cements was significantly higher for those without temporary cement contamination (8.2-10.6 MPa) than for those with temporary cement contamination (4.3-7.1 MPa). The γ(S) values decreased due to the decrease of γ(S)(h) values for the temporary cement-contaminated dentine. Contamination with temporary cements led to lower dentine bond strength. The presence of temporary cement interferes with the bonding performance of self-adhesive cements to dentine. Care should be taken in the methods of removal of temporary cement when using self-adhesive cements. Copyright © 2011 Elsevier Ltd. All rights reserved.

  17. Improved cement solidification of low and intermediate level radioactive wastes

    International Nuclear Information System (INIS)

    1993-01-01

    Cementation was the first and is still the most widely applied technique for the conditioning of low and intermediate level radioactive wastes. Compared with other solidification techniques, cementation is relatively simple and inexpensive. However, the quality of the final cemented waste forms depends very much on the composition of the waste and the type of cement used. Different kinds of cement are used for different kinds of waste and the compatibility of a specific waste with a specific cement type should always be carefully evaluated. Cementation technology is continuously being developed in order to improve the characteristics of cemented waste in accordance with the increasing requirements for quality of the final solidified waste. Various kinds of additives and chemicals are used to improve the cemented waste forms in order to meet all safety requirements. This report is meant mainly for engineers and designers, to provide an explanation of the chemistry of cementation systems and to facilitate the choice of solidification agents and processing equipment. It reviews recent developments in cementation technology for improving the quality of cemented waste forms and provides a brief description of the various cement solidification processes in use. Refs, figs and tabs

  18. Alpha radioactivity in Indian cement samples

    International Nuclear Information System (INIS)

    Nain, M.; Chauhan, R. P.; Chakarvarti, S. K.

    2006-01-01

    The essential constituents of radioactive and each of cements like lime, silica and alumina are derived from earth's crust in which radioactive elements like uranium, thorium etc are also present in varying amounts almost everywhere. These two elements are considered as the parent elements of uranium and thorium radioactive decay series in which radon and thoron are produced respectively as decay products. In the present study the samples of ordinary Portland cement , Portland pozzolana cement and some other cementious finishing materials like white cement, Plaster of Paris , cement putty etc were collected and analysed for radium and radon concentrations along with radon exhalation rates. Materials and Methods: Alpha sensitive LR-115 Type II plastic track detectors commonly known as S olid State Nuclear Track Detectors w ere used to measure the radium and radon concentration. The alpha particles emitted from the radon causes the radiation damaged tracks. The Chemical etching in NaOH at 60 C for about 90 minutes was done to reveal these latent tracks, which were then scanned and counted by an optical microscope of suitable magnification. By calculating the track density of registered tracks, the radon and radium concentrations along with exhalation rate of radon, were determined using required formulae. Results: The radon and radium concentration in various brands of cements found to vary from 333±9.9 to 506±13.3 Bq m-3 and from 3.7±0.1 to 5.6±0.2 Bq k g-1 while in various cementious finishing materials used in the construction, these were found to vary from 378±19.7 to 550±9.8 Bq m-3 and from 4.2±0.2 to 6.1±0.1 Bq Kg-1, respectively. Based on the data the mass and surface exhalation rates were also calculated Conclusion: The measurements indicate that there is marginal variation of the concentration of radium and radon in various brands of cements in India with lower levels in the cement samples having red oxide and higher levels in fly ash based cement

  19. Stimuli-responsive cement-reinforced rubber.

    Science.gov (United States)

    Musso, Simone; Robisson, Agathe; Maheshwar, Sudeep; Ulm, Franz-Josef

    2014-05-14

    In this work, we report the successful development of a cement-rubber reactive composite with reversible mechanical properties. Initially, the composite behaves like rubber containing inert filler, but when exposed to water, it increases in volume and reaches a stiffness that is intermediate between that of hydrogenated nitrile butadiene rubber (HNBR) and hydrated cement, while maintaining a relatively large ductility characteristic of rubber. After drying, the modulus increases even further up to 400 MPa. Wet/drying cycles prove that the elastic modulus can reversibly change between 150 and 400 MPa. Utilizing attenuated total reflection Fourier transform infrared spectroscopy), we demonstrate that the high pH produced by the hydration of cement triggers the hydrolysis of the rubber nitrile groups into carboxylate anions. Thus, the salt bridges, generated between the carboxylate anions of the elastomer and the cations of the filler, are responsible for the reversible variations in volume and elastic modulus of the composite as a consequence of environmental moisture exposure. These results reveal that cement nanoparticles can successfully be used to accomplish a twofold task: (a) achieve an original postpolymerization modification that allows one to work with carboxylate HNBR (HXNBR) not obtained by direct copolymerization of carboxylate monomers with butadiene, and (b) synthesize a stimuli-responsive polymeric composite. This new type of material, having an ideal behavior for sealing application, could be used as an alternative to cement for oil field zonal isolation applications.

  20. Microbial-influenced cement degradation: Literature review

    International Nuclear Information System (INIS)

    Rogers, R.D.; Hamilton, M.A.; McConnell, J.W. Jr.

    1993-03-01

    The Nuclear Regulatory Commission stipulates that disposed low-level radioactive waste (LLW) be stabilized. Because of apparent ease of use and normal structural integrity, cement has been widely used as a binder to solidify LLW. However, the resulting waste forms are sometimes susceptible to failure due to the actions of waste constituents, stress, and environment. This report reviews literature which addresses the effect of microbiologically influenced chemical attack on cement-solidified LLW. Groups of microorganisms are identified, which are capable of metabolically converting organic and inorganic substrates into organic and mineral acids. Such acids aggressively react with concrete and can ultimately lead to structural failure. Mechanisms inherent in microbial-influenced degradation of cement-based material are the focus of this report. This report provides sufficient evidence of the potential for microbial-influenced deterioration of cement-solidified LLW to justify the enumeration of the conditions necessary to support the microbiological growth and population expansion, as well as the development of appropriate tests necessary to determine the resistance of cement-solidified LLW to microbiological-induced degradation that could impact the stability of the waste form

  1. Possibilities of special cements in ceramic applications

    International Nuclear Information System (INIS)

    Capmas, A.; Bier, T.A.

    1993-01-01

    About 25 years ago, the only way to have confinement material for high temperature applications was to prepare a ceramic by sintering or fusion at high temperature. A new technology came, with the production of Low Cement Castables. This new product was obtained by a careful choice of the granulometry of the aggregates, an optimization of the defloculation of fine particles, including the cement (Calcium Aluminate Cement) and the addition of silica fume. Silica fume brought two improvements: a) a fluidifying effect, due partly to the low sensitivity of viscosity to pH, and partly to the geometric effect of the nicely spherical particle, b) a chemical effect, brought by the reaction of silica and Calcium Aluminate Cement to give a coherent zeolithic structure, through which water could escape during the first firing. From a ceramist point of view, it is interesting to understand how this components, nearly colloidal system mixed in water can be heated up to ceramization without any noticeable change in mechanical characteristics and shrinkage. From a more practical point of view, it is also interesting to realize that some characteristics, usually attributed only to ceramics, also apply with low cement castables technology: high compressive strength, flexural strength, corrosion resistance, abrasion resistance, impact resistance. (orig.)

  2. Accelerated hydration of high silica cements

    International Nuclear Information System (INIS)

    Walker, Colin; Yui, Mikazu

    2012-01-01

    Current Japanese designs for high level radioactive waste (HLW) repositories anticipate the use of both bentonite (buffer and backfill material) and cement based materials. Using hydrated Ordinary Portland Cement (OPC) as a grouting material is undesirable because the associated high pH buffer will have an undisputed detrimental effect on the performance of the bentonite buffer and backfill and of the host rock by changing its porosity. Instead, hydrated low pH cement (LopHC) grouting materials are being developed to provide a pH inferior or equal to 11 to reduce these detrimental effects. LopHC grouting materials use mixtures of superfine OPC (SOPC) clinker and silica fume (SF), and are referred as high silica cements (HSC). The focus of the present study was to identify the development of the unhydrated and hydrated mineral assemblage and the solution chemistry during the hydration of HSC. Since hydration experiments of cementitious materials are notably slow, a ball mill was used to accelerate hydration. This was done for two reasons. Firstly, to develop a method to rapidly hydrate cement based materials without the need for higher temperatures (which can alter the mineral assemblage), and secondly, to ensure that the end point of hydration was reached in a reasonable time frame and so to realize the final mineralogy and solution chemistry of hydrated HSC

  3. Reinforcing of Cement Composites by Estabragh Fibres

    Science.gov (United States)

    Merati, A. A.

    2014-04-01

    The influence of Estabragh fibres has been studied to improve the performance characteristics of the reinforced cement composites. The concrete shrinkage was evaluated by counting the number of cracks and measuring the width of cracks on the surface of concrete specimens. Although, the Estabragh fibres lose their strength in an alkali environment of cement composites, but, the ability of Estabragh fibres to bridge on the micro cracks in the concrete matrix causes to decrease the width of the cracks on the surface of the concrete samples in comparison with the plain concrete. However, considering the mechanical properties of specimens such as bending strength and impact resistance, the specimens with 0.25 % of Estabragh fibre performed better in all respects compared to the physical and mechanical properties of reinforced cement composite of concrete. Consequently, by adding 0.25 % of Estabragh fibres to the cement composite of concrete, a remarkable improvement in physical and mechanical properties of fibre-containing cement composite is achieved.

  4. Plug cementing: Horizontal to vertical conditions

    Energy Technology Data Exchange (ETDEWEB)

    Calvert, D.G.; Heathman, J.F.; Griffith, J.E.

    1995-12-31

    This paper presents an in-depth study of cement plug placement that was conducted with large-scale models for the improvement of plug cementing practices and plug integrity. Common hole and workstring geometries were examined with various rheology and density ratios between the drilling fluid and cement. The critical conditions dictating the difference between success and failure for various wellbore angles and conditions were explored, and the mechanisms controlling slurry movement before and after placement are now better understood. An understanding of these mechanisms allows the engineer to better tailor a design to specific hole conditions. Controversial concepts regarding plug-setting practices have been examined and resolved. The cumulative effects of density, rheology, and hole angle are major factors affecting plug success. While the Boycott effect and an extrusion effect were observed to be predominant in inclined wellbores, a spiraling or {open_quotes}roping{close_quotes} effect controls slurry movement in vertical wellbores. Ultimate success of a cement plug can be obtained if allowances are made for these effects in the job design, provided all other previously published recommended placement practices are followed. Results of this work can be applied to many sidetracking and plug-to-abandon operations. Additionally, the understanding of the fluid movement (creep) mechanisms holds potential for use in primary and remedial cementing work, and in controlling the placement of noncementitious fluids in the wellbore.

  5. International comparisons of energy efficiency in power, steel, and cement industries

    International Nuclear Information System (INIS)

    Oda, Junichiro; Akimoto, Keigo; Tomoda, Toshimasa; Nagashima, Miyuki; Wada, Kenichi; Sano, Fuminori

    2012-01-01

    Industrial energy efficiency is of paramount importance both for conserving energy resources and reducing CO 2 emissions. In this paper, we compare specific energy consumption among countries in fossil power generation, steel, and cement sectors. The evaluations were conducted using common system boundaries, allocation, and calculation methods. In addition, we disaggregate within sectors, such as with blast furnace–basic oxygen furnace (BF–BOF) steel and scrap-based electric arc furnace (Scrap-EAF) steel. The results reveal that characteristics vary by sub-sector. Regional differences in specific energy consumption are relatively large in the power, BF–BOF steel, and cement sectors. For coal power generation and BF–BOF steel production, continual maintenance and rehabilitation are of key importance. We confirm these key factors identified in the previous work on our estimated numerical values. In BF–BOF steel production, corrections for hot metal ratios (pig iron production per unit of BOF crude steel production) and quality of raw materials have a large effect on the apparent specific energy consumption. Available data is not yet sufficient for straightforward evaluation of the steel and cement sectors. - Highlights: ► We compare energy efficiency among countries in power, steel, and cement sectors. ► In steel and cement sectors, the results are provided in terms of specific energy consumption (GJ/ton of product). ► We distinguish BOF steel and EAF steel. ► New installation and continual maintenance are the key for energy efficiency. ► Corrections have a large impact on apparent specific energy consumption.

  6. Contact damage failure analyses of fretting wear behavior of the metal stem titanium alloy-bone cement interface.

    Science.gov (United States)

    Zhang, Lanfeng; Ge, Shirong; Liu, Hongtao; Wang, Qingliang; Wang, Liping; Xian, Cory J

    2015-11-01

    Although cemented titanium alloy is not favored currently in the Western world for its poor clinical and radiography outcomes, its lower modulus of elasticity and good biocompatibility are instrumental for its ability supporting and transforming physical load, and it is more suitable for usage in Chinese and Japanese populations due to their lower body weights and unique femoral characteristics. Through various friction tests of different cycles, loads and conditions and by examining fretting hysteresis loops, fatigue process curves and wear surfaces, the current study investigated fretting wear characteristics and wear mechanism of titanium alloy stem-bone cement interface. It was found that the combination of loads and displacement affected the wear quantity. Friction coefficient, which was in an inverse relationship to load under the same amplitude, was proportional to amplitudes under the same load. Additionally, calf serum was found to both lubricate and erode the wear interface. Moreover, cement fatigue contact areas appeared black/oxidative in dry and gruel in 25% calf serum. Fatigue scratches were detected within contact areas, and wear scars were found on cement and titanium surfaces, which were concave-shaped and ring concave/ convex-shaped, respectively. The coupling of thermoplastic effect and minimal torque damage has been proposed to be the major reason of contact damage. These data will be important for further studies analyzing metal-cement interface failure performance and solving interface friction and wear debris production issues. Copyright © 2015 Elsevier Ltd. All rights reserved.

  7. [The beginning of western medical education].

    Science.gov (United States)

    Kee, C D

    1992-01-01

    Our country had quite an advanced system of medical education during the era of the Koryo Kingdom, and during the Choson Dynasty, the Kyong Guk Dae Jon, in which a systematized medical education was clearly described, was compiled in the era of King Sejong. However, the educational system was not for Western medicine. Western medicine was first introduced to our country in the 9th year of King Injo (1631) when Chong Du Won, Yi Yong Jun, etc. returned from Yon Gyong (Beiuin) with Chik Bang Oe Gi. Knowledge of Western medicine was disseminated by Shil Hak (practical learning) scholars who read a translation in Chinese characters, of Chik Bang Oe Gi. Yi Ik (Song Ho), Yi Gyu Gyong (O ju), Choe Han Gi (Hye Gang), Chong Yak Yong (Ta San), etc., read books of Western medicine and introduced in writing the excellent theory of Western medicine. In addition, Yu Hyong Won (Pan Gye), Pak Ji Won (Yon Am), Pak Je Ga (Cho Jong), etc., showed much interest in Western medicine, but no writings by them about western medicine can be found. With the establishment of a treaty of amity with Japan in the 13th year of King Kojong (1876), followed by the succession of amity treaties with Western powers, foreigners including medical doctors were permitted to flow into this country. At that time, doctors Horace N. Allen, W. B. Scranton, John W. Heron, Rosetta Sherwood (Rosetta S. Hall), etc., came to Korea and inaugurated hospitals, where they taught Western medicine to Korean students. Dr. Horace N. Allen, with the permission of king Kojong, established Che Jung Won in April 1885, and in March 1886, he began at the hospital to provide education of Western medicine to Korean students who were recrutied by the Korean Government. However, the education was not conduted on a regular basis, only training them for work as assistants. This is considered to be the pioneer case of Western medical education in this country. Before that time, Japanese medical doctors came to Korea, but there are no

  8. Characterization of Two 20kDa-Cement Protein (cp20k) Homologues in Amphibalanus amphitrite

    KAUST Repository

    He, Li-Sheng; Zhang, Gen; Qian, Pei-Yuan

    2013-01-01

    The barnacle, Amphibalanus amphitrite, is a common marine fouling organism. Understanding the mechanism of barnacle adhesion will be helpful in resolving the fouling problem. Barnacle cement is thought to play a key role in barnacle attachment. Although several adult barnacle cement proteins have been identified in Megabalanus rosa, little is known about their function in barnacle settlement. In this study, two homologous 20k-cement proteins (cp20k) in Amphibalanus amphitrite, named Bamcp20k-1 and Bamcp20k-2, were characterized. The two homologues share primary sequence structure with proteins from other species including Megabalanus rosa and Fistulobalanus albicostatus. The conserved structure included repeated Cys domains and abundant charged amino acids, such as histidine. In this study we demonstrated that Bamcp20k-1 localized at the α secretory cells in the cyprid cement gland, while Bamcp20k-2 localized to the β secretory cells. The differential localizations suggest differential regulation for secretion from the secretory cells. Both Bamcp20k-1 and Bamcp20k-2 from cyprids dissolved in PBS. However, adult Bamcp20k-2, which was dominant in the basal shell of adult barnacles, was largely insoluble in PBS. Solubility increased in the presence of the reducing reagent Dithiothreitol (DTT), suggesting that the formation of disulfide bonds plays a role in Bamcp20k-2 function. In comparison, Bamcp20k-1, which was enriched in soft tissue, could not be easily detected in the shell and base by Western blot and easily dissolved in PBS. These differential solubilities and localizations indicate that Bamcp20k-1 and Bamcp20k-2 have distinct functions in barnacle cementing. © 2013 He et al.

  9. Characterization of Two 20kDa-Cement Protein (cp20k) Homologues in Amphibalanus amphitrite

    KAUST Repository

    He, Li-Sheng

    2013-05-22

    The barnacle, Amphibalanus amphitrite, is a common marine fouling organism. Understanding the mechanism of barnacle adhesion will be helpful in resolving the fouling problem. Barnacle cement is thought to play a key role in barnacle attachment. Although several adult barnacle cement proteins have been identified in Megabalanus rosa, little is known about their function in barnacle settlement. In this study, two homologous 20k-cement proteins (cp20k) in Amphibalanus amphitrite, named Bamcp20k-1 and Bamcp20k-2, were characterized. The two homologues share primary sequence structure with proteins from other species including Megabalanus rosa and Fistulobalanus albicostatus. The conserved structure included repeated Cys domains and abundant charged amino acids, such as histidine. In this study we demonstrated that Bamcp20k-1 localized at the α secretory cells in the cyprid cement gland, while Bamcp20k-2 localized to the β secretory cells. The differential localizations suggest differential regulation for secretion from the secretory cells. Both Bamcp20k-1 and Bamcp20k-2 from cyprids dissolved in PBS. However, adult Bamcp20k-2, which was dominant in the basal shell of adult barnacles, was largely insoluble in PBS. Solubility increased in the presence of the reducing reagent Dithiothreitol (DTT), suggesting that the formation of disulfide bonds plays a role in Bamcp20k-2 function. In comparison, Bamcp20k-1, which was enriched in soft tissue, could not be easily detected in the shell and base by Western blot and easily dissolved in PBS. These differential solubilities and localizations indicate that Bamcp20k-1 and Bamcp20k-2 have distinct functions in barnacle cementing. © 2013 He et al.

  10. Effect of temporary cements on the microtensile bond strength of self-etching and self-adhesive resin cement.

    Science.gov (United States)

    Carvalho, Edilausson Moreno; Carvalho, Ceci Nunes; Loguercio, Alessandro Dourado; Lima, Darlon Martins; Bauer, José

    2014-11-01

    The aim of this study was to evaluate the microtensile bond strength (µTBS) of self-etching and self-adhesive resin cement systems to dentin affected by the presence of remnants of either eugenol-containing or eugenol-free temporary cements. Thirty extracted teeth were obtained and a flat dentin surface was exposed on each tooth. Acrylic blocks were fabricated and cemented either with one of two temporary cements, one zinc oxide eugenol (ZOE) and one eugenol free (ZOE-free), or without cement (control). After cementation, specimens were stored in water at 37°C for 1 week. The restorations and remnants of temporary cements were removed and dentin surfaces were cleaned with pumice. Resin composite blocks were cemented to the bonded dentin surfaces with one of two resin cements, either self-etching (Panavia F 2.0) or self-adhesive (RelyX U-100). After 24 h, the specimens were sectioned to obtain beams for submission to µTBS. The fracture mode was evaluated under a stereoscopic loupe and a scanning electron microscope (SEM). Data from µTBS were submitted to two-way repeated-measure ANOVA and the Tukey test (alpha = 0.05). The cross-product interaction was statistically significant (p cements reduced the bond strength to Panavia self-etching resin cements only (p cements did not interfere in the bond strength to dentin of self-adhesive resin cements.

  11. An Experimental Study of Portland Cement and Superfine Cement Slurry Grouting in Loose Sand and Sandy Soil

    Directory of Open Access Journals (Sweden)

    Weijing Yao

    2018-04-01

    Full Text Available Grouting technology is widely applied in the fields of geotechnical engineering in infrastructure. Loose sand and sandy soil are common poor soils in tunnel and foundation treatments. It is necessary to use superfine cement slurry grouting in the micro-cracks of soil. The different effectiveness of Portland cement slurry and superfine cement slurry in sandy soil by the laboratory grouting experiment method were presented in this paper. The grouting situations of superfine cement slurry injected into sand and sandy soil were explored. The investigated parameters were the dry density, wet density, moisture content, internal friction angle, and cohesion force. The results show that the consolidation effect of superfine cement is better than that of Portland cement due to the small size of superfine cement particles. The superfine cement can diffuse into the sand by infiltration, extrusion, and splitting. When the water–cement ratio of superfine cement slurry is less than 2:1 grouting into loose sand, the dry and wet density decrease with the increase in the water–cement ratio, while the moisture content and cohesive force gradually increase. When the water–cement ratio of superfine cement slurry is 1:1 grouting into loose sand and sandy soil, the dry density, wet density, and cohesive force of loose sand are larger than those of sandy soil. The results of the experiment may be relevant for engineering applications.

  12. Heat of hydration measurements on cemented radioactive wastes. Part 1: cement-water pastes

    International Nuclear Information System (INIS)

    Lee, D.J.

    1983-12-01

    This report describes the hydration of cement pastes in terms of chemical and kinetic models. A calorimetric technique was used to measure the heat of hydration to develop these models. The effects of temperature, water/cement ratio and cement replacements, ground granulated blast furnace slag (BFS) and pulverised fuel ash (PFA) on the hydration of ordinary Portland cement (OPC) is reported. The incorporation of BFS or PFA has a marked effect on the hydration reaction. The effect of temperature is also important but changing the water/cement ratio has little effect. Results from cement pastes containing only water and cement yield total heats of reaction of 400, 200 and 100 kJ/kg for OPC, BFS and PFA respectively. Using the results from the models which have been developed, the effect of major salts present in radioactive waste streams can be assessed. Values of the total heat of reaction, the time to complete 50 percent reaction, and the energy of activation, can be compared for different waste systems. (U.K.)

  13. Preparing hydraulic cement from oil-shale residue

    Energy Technology Data Exchange (ETDEWEB)

    1921-08-28

    A process for preparation of hydraulic cement from oil-shale residue is characterized in that, as flux is used, rich-in-lime poor-in-sulfur portland-cement clinker, by which the usual gypsum addition, is avoided.

  14. compaction delay versus properties of cement-bound lateritic soil

    African Journals Online (AJOL)

    hp

    hour intervals on soil-cement mixes 3,5,8; and 1, 3, 5 percent cement contents by weight of dry soils, for ... stabilized soils were the Compaction test (Standard Proctor), the Unconfined Compressive. Strength .... Plastic limit (%). % passing BS ...

  15. Diffusion of radon through varying depths of cement

    International Nuclear Information System (INIS)

    Takriti, S.; Shweikani, R.; Ali, A.F.; Hushari, M.; Kheitou, M.

    2001-01-01

    Portland cement was mixed with different concentrations of radium chloride (1200, 2400 and 3600 Bq) to produce radioactive sources. These sources were surrounded with cement of different thickness (1, 2 and 4 cm). The release of radon from these sources (before and after being surrounded) was studied. The results showed that radon release from the sources itself was less then its release from the same source after being surrounded by cement, and the release did not change with the thickness of cement. Samples were covered with a thin layer of polyethylene before being surrounded with cement. It was found that this additional layer reduced the radon exhalation. This thin layer stopped any reaction between the source and the surrounding cement during solidification of the cement layers. These reactions are thought to be the reason for the increase of radon exhalation from the sources surrounded by cement

  16. stabilization of ikpayongo laterite with cement and calcium carbide

    African Journals Online (AJOL)

    PROF EKWUEME

    Laterite obtained from Ikpayongo was stabilized with 2-10 % cement and 2-10 % Calcium Carbide waste, for use .... or open dumping which have effect on surface and ... Table 1: Chemical Composition of Calcium Carbide Waste and Cement.

  17. Study on cementation of simulated radioactive borated liquid wastes

    International Nuclear Information System (INIS)

    Sun Qina; Li Junfeng; Wang Jianlong

    2010-01-01

    To compare sulfoaluminate cement with ordinary Portland cement on their cementation of radioactive borated liquid waste and to provide more data for formula optimization, simulated radioactive borated liquid waste were solidified by the two cements. 28 d compressive strength and strength losses after water/freezing/irradiation resistance tests were investigated. Leaching test and X-ray diffraction analysis were also conducted. The results show that it is feasible to solidify borated liquid wastes with sulfoaluminate cement and ordinary Portland cement with formulas used in the study. The 28 d compressive strengths, strength losses after tests and simulated nuclides leaching rates of the solidified waste forms meet the demand of GB 14569.1-93. The sulfoaluminate cement formula show better retention of Cs + than ordinary Portland cement formula. Boron, in form of B (OH) 4 - , incorporate in ettringite as solid solutions. (authors)

  18. Eco-efficiency of the world cement industry: A data envelopment analysis

    Energy Technology Data Exchange (ETDEWEB)

    Oggioni, G., E-mail: oggioni@eco.unibs.i [University of Brescia, Faculty of Economics, Department of Quantitative Methods, IT-25122 Brescia (Italy); Riccardi, R., E-mail: riccardi@ec.unipi.i [University of Brescia, Faculty of Economics, Department of Quantitative Methods, IT-25122 Brescia (Italy); Toninelli, R., E-mail: roberta.toninelli@unifi.i [University of Pisa, Faculty of Economics, Department of Statistics and Applied Mathematics, IT-56124 Pisa (Italy)

    2011-05-15

    Chemical reactions and the combustion of dirty fuels, such as coal and petroleum coke (petcoke), that are used in cement production processes generate a significant amount of CO{sub 2} emissions. In this paper, we provide an eco-efficiency measure for 21 prototypes of cement industries operating in many countries by applying both a data envelopment analysis (DEA) and a directional distance function approach, which are particularly suitable for models where several production inputs and desirable and undesirable outputs are taken into account. To understand whether this eco-efficiency is due to a rational utilization of inputs or to a real carbon dioxide reduction as a consequence of environmental regulation, we analyze the cases where CO{sub 2} emissions can either be considered as an input or as an undesirable output. Empirical results show that countries where cement industries invest in technologically advanced kilns and adopt alternative fuels and raw materials in their production processes are eco-efficient. This gives a comparative advantage to emerging countries, such as India and China, which are incentivized to modernize their production processes.

  19. Eco-efficiency of the world cement industry: A data envelopment analysis

    International Nuclear Information System (INIS)

    Oggioni, G.; Riccardi, R.; Toninelli, R.

    2011-01-01

    Chemical reactions and the combustion of dirty fuels, such as coal and petroleum coke (petcoke), that are used in cement production processes generate a significant amount of CO 2 emissions. In this paper, we provide an eco-efficiency measure for 21 prototypes of cement industries operating in many countries by applying both a data envelopment analysis (DEA) and a directional distance function approach, which are particularly suitable for models where several production inputs and desirable and undesirable outputs are taken into account. To understand whether this eco-efficiency is due to a rational utilization of inputs or to a real carbon dioxide reduction as a consequence of environmental regulation, we analyze the cases where CO 2 emissions can either be considered as an input or as an undesirable output. Empirical results show that countries where cement industries invest in technologically advanced kilns and adopt alternative fuels and raw materials in their production processes are eco-efficient. This gives a comparative advantage to emerging countries, such as India and China, which are incentivized to modernize their production processes.

  20. Experimental techniques for cement hydration studies

    Directory of Open Access Journals (Sweden)

    Andreas Luttge

    2011-10-01

    Full Text Available Cement hydration kinetics is a complex problem of dissolution, nucleation and growth that is still not well understood, particularly in a quantitative way. While cement systems are unique in certain aspects they are also comparable to natural mineral systems. Therefore, geochemistry and particularly the study of mineral dissolution and growth may be able to provide insight and methods that can be utilized in cement hydration research. Here, we review mainly what is not known or what is currently used and applied in a problematic way. Examples are the typical Avrami approach, the application of Transition State Theory (TST to overall reaction kinetics and the problem of reactive surface area. Finally, we suggest an integrated approach that combines vertical scanning interferometry (VSI with other sophisticated analytical techniques such as atomic force microscopy (AFM and theoretical model calculations based on a stochastic treatment.

  1. Transportation of ions through cement based materials

    International Nuclear Information System (INIS)

    Chatterji, S.

    1994-01-01

    Transportation of ions, both anions and cations, through cement based materials is one of the important processes in their durability and as such has been studied very extensively. It has been studied from the point of view of the reinforcement corrosion, alkali-silica reaction, sulfate attack on cement and concrete, as well as in the context of the use of the cement based materials in the disposal of nuclear waste. In this paper the fundamental equations of diffusion, i.e. Fick's two equations, Nernst and Nernst-Planck equations have been collected. Attention has been drawn to the fact that Fick's two equations are valid for non-ionic diffusants and that for ions the relevant equations are those of Nernst and Nernst-Planck. The basic measurement techniques have also been commented upon

  2. Heavy cement slurries; Pastas pesadas de cimento

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Francisco Avelar da; Conceicao, Antonio C. Farias [PETROBRAS, XX (Brazil). Distrito de Perfuracao do Nordeste. Div. de Tecnicas de Perfuracao; Marins, Carlos Cesar Silva [PETROBRAS, XX (Brazil). Dept. de Perfuracao. Div. de Revestimento e Cimentacao

    1990-12-31

    When going deeper in a high pressure well, the only way to successfully cement your casing or linear is through the use of heavy cement slurry. In 1987 PETROBRAS geologists presented to the Drilling Department a series of deep, hot and high pressure wells to be drilled. The Casing and Cement Division of this department then started a program to face this new challenge. This paper introduces the first part of this program and shows how PETROBRAS is dealing with heavy weight slurries. We present the slurry formulations tested in laboratory, the difficulties found in mixing them in the field, rheology measurements, API free water and API fluid loss from both laboratory and field samples. (author) 3 tabs.

  3. Immobilisation of ion exchange resins in cement

    International Nuclear Information System (INIS)

    Howard, C.G.; Jolliffe, C.B.; Lee, D.J.

    1990-02-01

    Over the last seven years, Low Oxidation State Metal Ion reagents (LOMI) have been used to decontaminate the 100 MW(e) Steam Generating Heavy Water Ractor (SGHWR) at Winfrith. The use of these reagents has resulted in a dilute ionic solution containing activation products which are produced by corrosion of metallic components in the reactor. It has been demonstrated that the amount of activity in the solution can be reduced using organic ion exchanger resins. These resins consist of a cross linked polystyrene with sulphonic acid or quaternary ammonium function groups and can be successfully immobilised in blended cement systems. The formulation which has been developed is produced from a 9 to 1 blend of ground granulated blast furnace slag (BFS) and ordinary Portland cement (OPC) containing 28% ion exchange resin in the water saturated form. If 6% Microsilica is added to the blended cement the waste loading can be increased to 36 w/o. (author)

  4. Application of Carbonate Looping to Cement Industry

    DEFF Research Database (Denmark)

    Lin, Weigang; Illerup, Jytte Boll; Dam-Johansen, Kim

    2012-01-01

    In the present work, cycle experiments of different types of limestone, cement raw meal and a mixture of limestone and clay were carried out in laboratory scale setups at more realistic conditions (i.e. calcination temperature is 950°C and CO2 concentration is 80%) to simulate the performance...... with an increase in the CO2 partial pressure during calcination, indicating enhancement of sintering by the presence of CO2. As sorbents, cement raw meal and the mixture of limestone and clay show a similar trend as limestone with respect to the decay of the CO2 carrying capacity and this capacity is lower than...... that of limestone at the same conditions in most cases. SEM and XRD analyses indicate that a combination of severe sintering and formation of calcium silicates attributes to the poor performance of the cement raw meal....

  5. Mechanical characterization of sisal reinforced cement mortar

    Directory of Open Access Journals (Sweden)

    R. Fujiyama

    2014-01-01

    Full Text Available This work aims at evaluating the mechanical behavior of sisal fiber reinforced cement mortar. The composite material was produced from a mixture of sand, cement, and water. Sisal fibers were added to the mixture in different lengths. Mechanical characterization of both the composite and the plain mortar was carried out using three point bend, compression, and impact tests. Specimens containing notches of different root radii were loaded in three point bending in an effort to determine the effect of the fibers on the fracture toughness of the material. The results obtained indicate that, while fiber reinforcement leads to a decrease in compressive strength, J-integral calculations at maximum load for the different notch root radii have indicated, particularly for the case of long fibers, a significant superiority of the reinforced material in comparison with the plain cement mortar, in consistence with the impact test data.

  6. CO2 Capture for Cement Technology

    DEFF Research Database (Denmark)

    Pathi, Sharat Kumar

    , whereas in a normal cement plant, it is 0.9 kg/ kg cl. However the thermal energy demand in the integrated plant increases from 3.9 MJ/ kg cl to 5.6 MJ/ kg cl. But on the other side this additional energy spent can be recovered as a high quality heat to generate electricity. The potential to generate...... electricity depends on the scale of the plant, the bigger the production capacity of cement plant the better, with capacity higher than 3400 tons of clinker/day is required to produce captive electricity to meet the demand both from the cement plant operations and from the CO2 capture system operations....

  7. Hospital waste ashes in Portland cement mortars

    International Nuclear Information System (INIS)

    Genazzini, C.; Zerbino, R.; Ronco, A.; Batic, O.; Giaccio, G.

    2003-01-01

    Nowadays, most concretes incorporate mineral additions such as pozzolans, fly ash, silica fume, blast furnace slag, and calcareous filler among others. Although the technological and economical benefits were the main reasons for the use of mineral additions, the prevention of environmental contamination by means of proper waste disposal becomes a priority. The chance of incorporating hospital waste ashes in Portland cement-based materials is presented here. Ash characterization was performed by chemical analysis, X-ray diffraction, radioactive material detection, and fineness and density tests. Conduction calorimetry and setting time tests were developed on pastes including ash contents from 0% to 100%. Mortars were prepared including ash contents up to 50% of cement. The results of setting time, temperature development, flexural and compressive strengths, water absorption, density, and leachability are analyzed. Results indicate that Portland cement systems could become an alternative for the disposal of this type of ashes

  8. Cementation of wastes with boric acid

    International Nuclear Information System (INIS)

    Tello, Cledola C.O.; Haucz, Maria Judite A.; Alves, Lilian J.L.; Oliveira, Arno H.

    2000-01-01

    In nuclear power plants (PWR) are generated wastes, such as concentrate, which comes from the evaporation of liquid radioactive wastes, and spent resins. Both have boron in their composition. The cementation process is one of the options to solidify these wastes, but the boron has a negative effect on the setting of the cement mixture. In this paper are presented the experiments that are being carried out in order to overcome this problem and also to improve the efficiency of the process. Simulated wastes were cemented using additives (clays, admixtures etc.). In the process and product is being evaluated the effect of the amount, type and addition order of the materials. The mixtures were selected in accordance with their workability and incorporated waste. The solidified products are monolithic without free water with a good mechanical resistance. (author)

  9. Hydration kinetics of cement composites with varying water-cement ratio using terahertz spectroscopy

    Science.gov (United States)

    Ray, Shaumik; Dash, Jyotirmayee; Devi, Nirmala; Sasmal, Saptarshi; Pesala, Bala

    2015-03-01

    Cement is mixed with water in an optimum ratio to form concrete with desirable mechanical strength and durability. The ability to track the consumption of major cement constituents, viz., Tri- and Dicalcium Silicates (C3S, C2S) reacting with water along with the formation of key hydration products, viz., Calcium-Silicate-Hydrate (C-S-H) which gives the overall strength to the concrete and Calcium Hydroxide (Ca(OH)2), a hydration product which reduces the strength and durability, using an efficient technique is highly desirable. Optimizing the amount of water to be mixed with cement is one of the main parameters which determine the strength of concrete. In this work, THz spectroscopy has been employed to track the variation in hydration kinetics for concrete samples with different water-cement ratios, viz., 0.3, 0.4, 0.5 and 0.6. Results show that for the sample with water-cement ratio of 0.3, significant amount of the C3S and C2S remain unreacted even after the initial hydration period of 28 days while for the cement with water-cement ratio of 0.6, most of the constituents get consumed during this stage. Analysis of the formation of Ca(OH)2 has been done which shows that the concrete sample with water-cement ratio of 0.6 produces the highest amount of Ca(OH)2 due to higher consumption of C3S/C2S in presence of excess water which is not desirable. Samples with water-cement ratio of 0.4 and 0.5 show more controlled reaction during the hydration which can imply formation of an optimized level of desired hydration products resulting in a more mechanically strong and durable concrete.

  10. Cementation of the solid radioactive waste with polymer-cement solutions using the method of impregnation

    International Nuclear Information System (INIS)

    Gorbunova, O.

    2015-01-01

    Cementation of solid radioactive waste (SRW), i.e. inclusion of solid radioactive waste into cement matrix without cavities - is one of the main technological processes used for conditioning low and intermediate level radioactive waste. At FSUE 'Radon' the industrialized method of impregnation has been developed and since 2003 has been using for cementation of solid radioactive waste. The technology is that the polymer-cement solution, having high penetrating properties, is supplied under pressure through a tube to the bottom of the container in which solid radioactive waste has preliminarily been placed. The polymer-cement solution is evenly moving upwards through the channels between the particles of solid radioactive waste, fills the voids in the bulk volume of the waste and hardens, forming a cement compound, the amount of which is equal to the original volume. The aim of the investigation was a selection of a cement solution suitable for SRW impregnation (including fine particles) without solution depletion and bottom layers stuffing. It has been chosen a polymer: PHMG (polyhexamethylene-guanidine), which is a stabilizing and water-retaining component of the cement solution. The experiments confirm that the polymer increases the permeability of the cement solution by a 2-2.5 factor, the viscosity by a 1.2 factor, the stability of the consistency by a 1.5-1.7 factor, and extends the operating range of the W/C ratio to 0.5-1.1. So it is possible to penetrate a volume of SRW bigger by a 1.5-2.0 factor. It has been proved, that PHMG polymer increases strength and frost-resistance of the final compounds by a 1.8-2.7 factor, and contributes to fast strength development at the beginning of hardening and it decreases Cs-137 leashing rate by a 1.5-2 factor

  11. Comparison of modified sulfur cement and hydraulic cement for encapsulation of radioactive and mixed wastes

    International Nuclear Information System (INIS)

    Kalb, P.D.; Heiser, J.H. III; Colombo, P.

    1990-01-01

    The majority of solidification/stabilization systems for low-level radioactive waste (LLW) and mixed waste, both in the commercial sector and at Department of Energy (DOE) facilities, utilize hydraulic cement (such as portland cement) to encapsulate waste materials and yield a monolithic solid waste form for disposal. Because hydraulic cement requires a chemical hydration reaction for setting and hardening, it is subject to potential interactions between elements in the waste and binder that can retard or prevent solidification. A new and innovative process utilizing modified sulfur cement developed by the US Bureau of Mines has been applied at Brookhaven National Laboratory (BNL) for the encapsulation of many of these problem wastes. Modified sulfur cement is a thermoplastic material, and as such, it can be heated above its melting point, combined with dry waste products to form a homogeneous mixture, and cooled to form a monolithic solid product. Under sponsorship of the DOE, research and development efforts at BNL have successfully applied the modified sulfur cement process for treatment of a range of LLWs including sodium sulfate salts, boric acid salts, and incinerator bottom ash and for mixed waste contaminated incinerator fly ash. Process development studies were conducted to determine optimal waste loadings for each waste type. Property evaluation studies were conducted to test waste form behavior under disposal conditions by applying relevant performance testing criteria established by the Nuclear Regulatory Commission (for LLW) and the Environmental Protection Agency (for hazardous wastes). Based on both processing and performance considerations, significantly greater waste loadings were achieved using modified sulfur cement when compared with hydraulic cement. Technology demonstration of the modified sulfur cement encapsulation system using production-scale equipment is scheduled for FY 1991

  12. STUDY OF FUNCTIONAL RESULTS OF CEMENTED TOTAL HIP REPLACEMENT BY MOORE’S APPROACH

    Directory of Open Access Journals (Sweden)

    Arunim

    2016-02-01

    Full Text Available INTRODUCTION The total hip replacement (THR has probably become the surgical procedure of choice for vide variety of hip joint disabling diseases. The prosthesis used for THR is often grouped into cemented, cement-less and hybrid ones. There has been increasing trends in use of cement-less components citing more number of complications namely loosening, increased infection rate etc. however with additional cost factors as well. We conducted this study to ascertain whether in a developing country like ours should we really switch over to un-cemented hip replacements dreading such complications or can we still use cemented prosthesis with equally good if not better results. METHODS A study of functional results of cemented total hip replacement was done in patients with varied age groups ranging from 40 years to 75 years with the average age being 54.8 years. 20 patients with 21 diseased hips were treated with cemented total hip replacement by Moore’s posterior approach at NSCB Subharti medical college, Meerut, UP from December 2010 to December 2013 and reviewed thereafter with an average follow-up period of 4.2 years. Average surgical time required was one and half hour. Patients were asked to come for follow up on 1st month, 3rd month and 6th month and then every 6 months and were assessed as per modified Harris Hip Score. RESULTS All the patients were evaluated according to the Modified Harris Hip Scoring system. The results showed 14(67% hips with excellent results, 4(19% with good results, and 3(14% hips with fair results. No poor outcome was noted in this study. 2 cases of dislocation (10% were noted one on the 5th post-operative day and the other occurred after the patient was discharged from the institution. CONCLUSIONS The management of diseased and destroyed hips with chronic pain with cemented total hip replacement is effective and gives stable, mobile and painless hip joint to the patient. Functional results are excellent and

  13. Density and mechanical properties of calcium aluminate cement

    Science.gov (United States)

    Ahmed, Syed Taqi Uddin; Ahmmad, Shaik Kareem

    2018-04-01

    Calcium aluminate cements are a special type of cements which have their composition mainly dominated by the presence of Monocalcium Aluminates. In the present paper for the first time we have shown theoretical density and elastic constants for various calcium aluminate cements. The density of the present CAS decrease with aluminates presents in the cement. Using the density data, the elastic moduli namely Young's modulus, bulk and shear modulus show strong linear dependence as a function of compositional parameter.

  14. Comparison of creep of the cement pastes included fly ash

    Directory of Open Access Journals (Sweden)

    Padevět Pavel

    2017-01-01

    Full Text Available The paper is devoted to comparison of creep of cement pastes containing fly ash admixture. The size of creep in time depends on the amount of components of the cement paste. Attention is paid to the content of classical fly ash in cement paste and its impact on the size of creep. The moisture of cement pastes is distinguished because it significantly affects the rheological properties of the material.

  15. Expansion control for cementation of incinerated ash

    International Nuclear Information System (INIS)

    Nakayama, T.; Suzuki, S.; Hanada, K.; Tomioka, O.; Sato, J.; Irisawa, K.; Kato, J.; Kawato, Y.; Meguro, Y.

    2015-01-01

    A method, in which incinerated ash is solidified with a cement material, has been developed to dispose of radioactive incinerated ash waste. A small amount of metallic Al, which was not oxidized in the incineration, existed in the ash. When such ash was mixed with a cement material and water, alkaline components in the ash and the cement were dissolved in the mixing water and then metallic Al reaction with the alkaline compounds resulted in generation of H 2 . Because the H 2 generation began immediately just after the mixing, H 2 bubbles pushed up the mixed grout material and an expanded solidified form was obtained. The expansion leads to lowering the strength of the solidified form and making harmful void. In this study, we tried to control H 2 generation from the reaction of metallic Al in the cementation by means of following two methods, one was a method to let metallic Al react prior to the cementation and the other was a method to add an expansion inhibitor that made an oxide film on the surface of metallic Al. In the pre-treatment, the ash was soaked in water in order to let metallic Al react with it, and then the ash with the immersion solution was dried at 105 Celsius degrees. The pre-treated ash was mixed with an ordinary portland cement and water. The inhibitor of lithium nitrite, sodium nitrite, phosphoric acid, or potassium dihydrogen phosphate was added at the mixing process. The solidified forms prepared using the pre-treated ash and lithium nitrite were not expanded. Phosphoric acid and sodium nitrite were effective for expansion control, but potassium dihydrogen phosphate did not work. (authors)

  16. Durability of pulp fiber-cement composites

    Science.gov (United States)

    Mohr, Benjamin J.

    Wood pulp fibers are a unique reinforcing material as they are non-hazardous, renewable, and readily available at relatively low cost compared to other commercially available fibers. Today, pulp fiber-cement composites can be found in products such as extruded non-pressure pipes and non-structural building materials, mainly thin-sheet products. Although natural fibers have been used historically to reinforce various building materials, little scientific effort has been devoted to the examination of natural fibers to reinforce engineering materials until recently. The need for this type of fundamental research has been emphasized by widespread awareness of moisture-related failures of some engineered materials; these failures have led to the filing of national- and state-level class action lawsuits against several manufacturers. Thus, if pulp fiber-cement composites are to be used for exterior structural applications, the effects of cyclical wet/dry (rain/heat) exposure on performance must be known. Pulp fiber-cement composites have been tested in flexure to examine the progression of strength and toughness degradation. Based on scanning electron microscopy (SEM), environmental scanning electron microscopy (ESEM), energy dispersive spectroscopy (EDS), a three-part model describing the mechanisms of progressive degradation has been proposed: (1) initial fiber-cement/fiber interlayer debonding, (2) reprecipitation of crystalline and amorphous ettringite within the void space at the former fiber-cement interface, and (3) fiber embrittlement due to reprecipitation of calcium hydroxide filling the spaces within the fiber cell wall structure. Finally, as a means to mitigate kraft pulp fiber-cement composite degradation, the effects of partial portland cement replacement with various supplementary cementitious materials (SCMs) has been investigated for their effect on mitigating kraft pulp fiber-cement composite mechanical property degradation (i.e., strength and toughness

  17. Controls on Cementation in a Chalk Reservoir

    DEFF Research Database (Denmark)

    Meireles, Leonardo Teixeira Pinto; Hussein, A.; Welch, M.J.

    In this study, we identify different controls on cementation in a chalk reservoir. Biot’s coefficient, a measure of cementation, stiffness and strength in porous rocks, is calculated from logging data (bulk density and sonic Pwave velocity). We show that Biot’s coefficient is correlated...... to the water saturation of the Kraka reservoir and is partly controlled by its stratigraphic sub-units. While the direct causal relationship between Biot’s coefficient and water saturation cannot be extended for Biot’s coefficient and porosity, a correlation is also identified between the two, implying...

  18. Porosity and liquid absorption of cement paste

    DEFF Research Database (Denmark)

    Krus, M.; Hansen, Kurt Kielsgaard; Kunzel, H. M.

    1997-01-01

    be a slowing-down effect which is related to water because the absorption of organic liquids, such as hexane, is quite normal. Measurements of the porosity of hardened cement paste determined by helium pycnometry and water saturation show that water molecules can enter spaces in the microstructure which...... are not accessible to the smaller helium atoms. Considering the results of dilatation tests both before and after water and hexane saturation, it seems possible that a contraction of capillary pores due to moisture-related swelling of the cement gel leads to the non-linear water absorption over the square root...

  19. Tanzania. A developing mining country; Tansania. Bergbauland im Aufbruch

    Energy Technology Data Exchange (ETDEWEB)

    Elsner, Harald [Bundesanstalt fuer Geowissenschaften und Rohstoffe (BGR), Hannover (Germany). Fachbereich Wirtschaftsgeologie der mineralischen Rohstoffe

    2009-03-19

    Tanzania is the rising country in East Africa, to which not least of all the booming mining sector contributes. Many large gold mines, two precious stone mines, three cement works and smaller facilities for extraction of salt, phosphates, gypsum, pozzolana, coal and coloured gemstones currently characterise the mining sector. The high mineral potential of the country combined with the mining legislation favouring investment will also lead in future to the development of further deposits in particular, nickel, gold, coal and graphite. (orig.)

  20. Characterization of monolith block of spent resin cementation

    International Nuclear Information System (INIS)

    Prayitno; Endro-Kismolo; Isman MT

    1996-01-01

    Spent resin immobilization process with cement was done to prevent release of radionuclide in the ultimate storage or disposal. The varied Composition of water/cement ratio in the cementation process were 0.3; 0.4; 0.5 and the various weight of resin waste are 25 g, 37.5 g and 50 gram. The compressive strength of the various water/cement ratio without spent resin was bigger than 0.3. This investigation proved that the compressive strength of Tiga Roda cement was bigger than those of Gresik cement or Nusantara cement. The compressive of the cement block of were the spent resin cementation was influenced by the water/cement ratio and the total spent resin addition. The best condition reached at the water/cement ratio of 0.3 and 25 gram spent resin, was compressive strength of 17.86 N/mm 2 . Leaching rate of the various weight composition of spent resin cementation for 91 days were between 10 -2 - 10 -4 gram.cm -2 .day -1

  1. Immobilisation of shredded waste in a cement monolith

    International Nuclear Information System (INIS)

    James, J.M.; Smith, D.L.

    1987-11-01

    During 1983/84 work was continued on the development of the process for the encapsulation of shredded waste in cement. Using simulant shredded waste the conditions for operating the process on the 500 litres scale have been established. Evaluation of the cemented product showed that it was satisfactorily infilled with cement grout with no significant voidage. (author)

  2. 21 CFR 888.4220 - Cement monomer vapor evacuator.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Cement monomer vapor evacuator. 888.4220 Section... (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Surgical Devices § 888.4220 Cement monomer vapor evacuator. (a) Identification. A cement monomer vapor evacuator is a device intended for use during surgery to contain or remove...

  3. LEACHING BOUNDARY IN CEMENT-BASED WASTE FORMS

    Science.gov (United States)

    Cement-based fixation systems are among the most commonly employed stabilization/solidification techniques. These cement haste mixtures, however, are vulnerable to ardic leaching solutions. Leaching of cement-based waste forms in acetic acid solutions with different acidic streng...

  4. 21 CFR 888.4230 - Cement ventilation tube.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Cement ventilation tube. 888.4230 Section 888.4230...) MEDICAL DEVICES ORTHOPEDIC DEVICES Surgical Devices § 888.4230 Cement ventilation tube. (a) Identification. A cement ventilation tube is a tube-like device usually made of plastic intended to be inserted into...

  5. 21 CFR 888.4210 - Cement mixer for clinical use.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Cement mixer for clinical use. 888.4210 Section... (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Surgical Devices § 888.4210 Cement mixer for clinical use. (a) Identification. A cement mixer for clinical use is a device consisting of a container intended for use in mixing...

  6. Geotechnical properties of clayey soil stabilized with cement ...

    African Journals Online (AJOL)

    The study was conducted to investigate the different effects of cement-sawdust ash and cement on a clayey soil sampled from Mandate Lodge, Landmark University, Omu-Aran, Nigeria. The binder mix of cementsawdust ash (CSDA) was mixed in a ratio of 1:1. The CSDA and cement were added to the soil samples at ...

  7. the effect of cement dust exposure on haematological and liver

    African Journals Online (AJOL)

    Daniel Owu

    LIVER FUNCTION PARAMETERS OF CEMENT FACTORY WORKERS IN. SOKOTO ... to cement dust. (mean years of exposure = 9.6± 1.5 years) and 46 matched unexposed controls. ... was assessed by measuring serum liver function tests. .... of cement, may increase the risk of autoimmune disease. ... Mosby's Manual of.

  8. Optimization of mix design by using superplasticized cement

    International Nuclear Information System (INIS)

    Khaskheli, G.B.; Kumar, A.; Umrani, A.N.

    2009-01-01

    Superplasticizers are high range water reducers which are capable of producing high-strength concrete with low permeability. Recently a cement factory in Sindh has launched SPC (Superplasticized Cement) which contains the required amount of superplasticizers. It is needed to investigate its performance compared to that of OPC (Ordinal-Y Portland Cement). This study is framed to optimize various strengths of structural concrete through the use of SPC of the cement factory. In total 288 cubes (6x6x6) were cast and tested for four different compressive strength of concrete (8000, 6000, 5000 and 4000 psi) manufactured with two brands of cement (OPC and SPC) of the cement factory and two different coarse aggregate sizes (40 and 20 mm) at three different curing ages (7,14 and 28 days). The effect on compressive strength of structural concrete was also observed by adopting 5 and 10% reduction in cement content of the superplasticized cement. Results have indicated that structural concrete made with superplasticized cement could give higher compressive strength than that of OPC at all the curing ages, and 10% saving in cement content could be achieved by using superplasticized cement. Structural concrete made with superplasticized cement could attain higher strength in a shorter period of time, and workability of structural concrete could be increased by using SPC. (author)

  9. Computation of X-ray powder diffractograms of cement components ...

    Indian Academy of Sciences (India)

    Computation of X-ray powder diffractograms of cement components and its application to phase analysis and hydration performance of OPC cement. Rohan Jadhav N C Debnath. Volume 34 Issue 5 August 2011 pp 1137- ... Keywords. Portland cement; X-ray diffraction; crystal structure; characterization; Rietveld method.

  10. Assessment of Pollution Potentialities of some Portland Cement ...

    African Journals Online (AJOL)

    Chemical analysis of some Portland cement commonly used in Nigeria was carried out. All the cement studies were found to be good for concrete work especially where no special property is required. The concentration levels of heavy metals in all the cement samples were above the tolerance limit and therefore need to ...

  11. Radiopacity of portland cement associated with different radiopacifying agents.

    Science.gov (United States)

    Húngaro Duarte, Marco Antonio; de Oliveira El Kadre, Guâniara D'arc; Vivan, Rodrigo Ricci; Guerreiro Tanomaru, Juliane Maria; Tanomaru Filho, Mário; de Moraes, Ivaldo Gomes

    2009-05-01

    This study evaluated the radiopacity of Portland cement associated with the following radiopacifying agents: bismuth oxide, zinc oxide, lead oxide, bismuth subnitrate, bismuth carbonate, barium sulfate, iodoform, calcium tungstate, and zirconium oxide. A ratio of 20% radiopacifier and 80% white Portland cement by weight was used for analysis. Pure Portland cement and dentin served as controls. Cement/radiopacifier and dentin disc-shaped specimens were fabricated, and radiopacity testing was performed according to the ISO 6876/2001 standard for dental root sealing materials. Using Insight occlusal films, the specimens were radiographed near to a graduated aluminum stepwedge varying from 2 to 16 mm in thickness. The radiographs were digitized and radiopacity compared with the aluminum stepwedge using Digora software (Orion Corporation Soredex, Helsinki, Finland). The radiographic density data were converted into mmAl and analyzed statistically by analysis of variance and Tukey-Kramer test (alpha = 0.05). The radiopacity of pure Portland cement was significantly lower (p cement/radiopacifier mixtures were significantly more radiopaque than dentin and Portland cement alone (p cement/bismuth oxide and Portland cement/lead oxide presented the highest radiopacity values and differed significantly from the other materials (p cement/zinc oxide presented the lowest radiopacity values of all mixtures (p cement as radiopacifying agents. However, the possible interference of the radiopacifiers with the setting chemistry, biocompatibility, and physical properties of the Portland cement should be further investigated before any clinical recommendation can be done.

  12. Automated system for management of cementation line at Kursk NPP

    International Nuclear Information System (INIS)

    Petukhov, K.S.; Troshchenko, V.G.; Osintsev, V.V.; Molotkov, V.P.

    2005-01-01

    At Kursk NPP technological scheme of radioactive wastes tempering by dry cement mixture in continuously working mixer with continuous dosing of cement mixture components is accepted. The automated system designed for control and management of liquid radioactive wastes cementation in real time is represented [ru

  13. Substitution of strontium for calcium in glass ionomer cements (Part ...

    African Journals Online (AJOL)

    Substitution of strontium for calcium in glass ionomer cements (Part 1): Glass synthesis and characterisation, and the effects on the cement handling variables and ... acid to form glass ionomer cements, whose properties were investigated at different time points: working and setting times were determined by rheometry; and, ...

  14. CEMENT KILN DUST AS A MATERIAL FOR BUILDING BLOCKS ...

    African Journals Online (AJOL)

    This paper presents the results of a study on the properties of hollow sandcrete blocks with cement kiln dust (CKD) as an additive and as a replacement for ordinary portland cement (OPC). When CKD was used as a replacement for cement, the compressive strength and density of blocks generally decreased with higher ...

  15. An Experimental Study of Portland Cement and Superfine Cement Slurry Grouting in Loose Sand and Sandy Soil

    OpenAIRE

    Weijing Yao; Jianyong Pang; Yushan Liu

    2018-01-01

    Grouting technology is widely applied in the fields of geotechnical engineering in infrastructure. Loose sand and sandy soil are common poor soils in tunnel and foundation treatments. It is necessary to use superfine cement slurry grouting in the micro-cracks of soil. The different effectiveness of Portland cement slurry and superfine cement slurry in sandy soil by the laboratory grouting experiment method were presented in this paper. The grouting situations of superfine cement slurry inject...

  16. Determining the water-cement ratio, cement content, water content and degree of hydration of hardened cement paste: Method development and validation on paste samples

    International Nuclear Information System (INIS)

    Wong, H.S.; Buenfeld, N.R.

    2009-01-01

    We propose a new method to estimate the initial cement content, water content and free water/cement ratio (w/c) of hardened cement-based materials made with Portland cements that have unknown mixture proportions and degree of hydration. This method first quantifies the composition of the hardened cement paste, i.e. the volumetric fractions of capillary pores, hydration products and unreacted cement, using high-resolution field emission scanning electron microscopy (FE-SEM) in the backscattered electron (BSE) mode and image analysis. From the obtained data and the volumetric increase of solids during cement hydration, we compute the initial free water content and cement content, hence the free w/c ratio. The same method can also be used to calculate the degree of hydration. The proposed method has the advantage that it is quantitative and does not require comparison with calibration graphs or reference samples made with the same materials and cured to the same degree of hydration as the tested sample. This paper reports the development, assumptions and limitations of the proposed method, and preliminary results from Portland cement pastes with a range of w/c ratios (0.25-0.50) and curing ages (3-90 days). We also discuss the extension of the technique to mortars and concretes, and samples made with blended cements.

  17. Influence of agglomeration of a recycled cement additive on the hydration and microstructure development of cement based materials

    NARCIS (Netherlands)

    Yu, R.; Shui, Z.H.

    2013-01-01

    This paper presents a study, including experimental and mechanism analysis, on investigating the effect of agglomeration of a recycled cement additive on the hydration and microstructure development of cement based materials. The recycled additive is firstly produced form waste hardened cement paste

  18. Comparative evaluation of marginal leakage of provisional crowns cemented with different temporary luting cements: In vitro study

    Directory of Open Access Journals (Sweden)

    Sheen Juneja Arora

    2016-01-01

    Conclusion: The temporary cements with eugenol showed more microleakage than those without eugenol. SC-10 crowns showed more microleakage compared to Protemp 4 crowns. SC-10 crowns cemented with Kalzinol showed maximum microleakage and Protemp 4 crowns cemented with HY bond showed least microleakage.

  19. Dose response effect of cement dust on respiratory muscles competence in cement mill workers.

    Science.gov (United States)

    Meo, Sultan A; Azeem, Muhammad A; Qureshi, Aijaz A; Ghori, G Moinudin; Al-Drees, Abdul Majeed; Feisal Subhan, Mirza Muhammad

    2006-12-01

    Electromyography (EMG) of respiratory muscles is a reliable method of assessing the ventilatory muscle function, but still its use has not been fully utilized to determine the occupational and environmental hazards on respiratory muscles. Therefore, EMG of intercostal muscles was performed to determine the dose response effect of cement dust on respiratory muscles competence. Matched cross-sectional study of EMG in 50 non-smoking cement mill workers with an age range of 20 - 60 years, who worked without the benefit of cement dust control ventilation or respiratory protective devices. EMG was performed by using surface electrodes and chart recorder. Significant reduction was observed in number of peaks (p competence and stratification of results shows a dose-effect of years of exposure in cement mill.

  20. Micropore characteristics of organic matter pools in cemented and non-cemented podzolic horizons

    NARCIS (Netherlands)

    Catoni, M.; D'amico, M.E.; Mittelmeijer-Hazeleger, M.C.; Rothenberg, G.; Bonifacio, E.

    2014-01-01

    In Podzols, organic matter (OM) is stabilized mainly by interaction with minerals, as a direct consequence of pedogenic processes. Metal-organic associations strongly affect OM surface features, particularly microporosity. Cemented ortstein horizons (CM) may form during podzolization, accompanied by