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  1. EDITORIAL: The 19th MicroMechanics Europe Workshop (MME 2008) The 19th MicroMechanics Europe Workshop (MME 2008)

    NASA Astrophysics Data System (ADS)

    Schnakenberg, Uwe

    2009-07-01

    This special issue of Journal of Micromechanics and Microengineering is devoted to the 19th MicroMechanics Europe Workshop (MME 08), which took place at the RWTH Aachen University, Aachen, Germany, from 28-30 September, 2008. The workshop is a well recognized and established European event in the field of micro system technology using thin-film technologies for creating micro components, micro sensors, micro actuators, and micro systems. The first MME Workshop was held 1989 in Enschede (The Netherlands) and continued 1990 in Berlin (Germany), 1992 in Leuven (Belgium), and then was held annually in Neuchâtel (Switzerland), Pisa (Italy), Copenhagen (Denmark), Barcelona (Spain), Southampton (UK), Ulvik in Hardanger (Norway), Gif-sur-Yvette (France), Uppsala (Sweden), Cork (Ireland), Sinaia (Romania), Delft (The Netherlands), Leuven (Belgium), Göteborg (Sweden), Southampton (UK), and in Guimarães (Portugal). The two day workshop was attended by 180 delegates from 26 countries all over Europe and from Armenia, Austria, Bulgaria, Canada, China, Cuba, Iran, Japan, Korea, Malaysia, Taiwan, Turkey, and the United States of America. A total of 97 papers were accepted for presentation and there were a further five keynote presentations. I am proud to present 22 high-quality papers from MME 2008 selected for their novelty and relevance to Journal of Micromechanics and Microengineering. All the papers went through the regular reviewing procedure of IOP Publishing. I am eternally grateful to all the referees for their excellent work. I would also like to extend my thanks to the members of the Programme Committee of MME 2008, Dr Reinoud Wolffenbuttel, Professor José Higino Correia, and Dr Patrick Pons for pre-selection of the papers as well as to Professor Robert Puers for advice on the final selection of papers. My thanks also go to Dr Ian Forbes of IOP Publishing for managing the entire process and to the editorial staff of Journal of Micromechanics and Microengineering. I

  2. [Cholera in Europe and Denmark in the 19th century].

    PubMed

    Bonderup, G

    1996-01-01

    There are several reasons for dealing with cholera in the 19th century: it acted as a spotlight throwing into sharp relief the darkest corners of society that are seldom mentioned in the sources. We learn about everyday life in large parts of the population, especially the poor. The fight against the disease also reveals how a society worked socially and politically. When cholera arrived in Europe -- the first time was in the 1830's and several times after that--the population reacted very violently, often by lynching doctors, while the authorities more or less let matters take their course. That is why international researchers have come to see cholera as a catalyst for the constantly latent social unrest following in the train of wars and revolutions. During my research on cholera in Denmark it became clear to me that matters were different here. There were no riots, nor any signs of social unrest--neither before nor after the outbreak of cholera. On the contrary, the authorities and the population joined forces against the epidemic. There was an atmosphere of mutual trust, and almost everybody turned out to be worthy of such trust. That points to a balanced society based on consensus, so cholera also functions as a detector of the fundamental structure of a society.

  3. The Rise of Age Homogamy in 19th Century Western Europe

    ERIC Educational Resources Information Center

    van de Putte, Bart; Van Poppel, Frans; Vanassche, Sofie; Sanchez, Maria; Jidkova, Svetlana; Eeckhaut, Mieke; Oris, Michel; Matthijs, Koen

    2009-01-01

    In many parts of Western Europe the age at first marriage and the level of celibacy declined in the second half of the 19th century. This weakening of the European marriage pattern (EMP) can be interpreted as a "classic" response to the increase of the standard of living, but a more far-reaching interpretation is that the erosion of the…

  4. Causes of the rich flood period recorded in the South of Europe in the middle of the 19th century

    NASA Astrophysics Data System (ADS)

    Llasat, Maria-Carmen; Barrera-Escoda, Antonio; Brázdil, Rudolf; Kiss, Andrea; Coeur, Denis; Lang, Michel

    2015-04-01

    At the end of the Little Ice Age an increase in flood frequency and impacts was produced in the Southwest of Europe. In France, the Loire River recorded three extreme floods on the years 1846, 1856 and 1866, while the Tech River and the Têt River recorded other important events on 1842 and 1843. This last one was more spread and also affected the Aude River that recorded other remarkable floods in 1858 and 1862. The Ardèche River recorded seven flood events between 1846 and 1861 (Lang et al, 2001) and some of these events also affected the Drac and Isère Rivers, with more than 20 flood events in Grenoble (Coeur, 2003). The Rhone River was also recorded extreme floods (2003). In Spain, more than 60 flood events were recorded in Catalonia on the period 1840-1870 (Llasat et al, 2005), but also the Duero River in the western part of the Iberian Peninsula, and the Turia, Jucar and Ebro Rivers in the Eastern part of the same experienced catastrophic floods. The contribution analyses the causes that have produced this anomalous flood period, with particular consideration to the fact that the usual meteorological situations associated to heavy rainfalls and floods in these regions and catchments are not the same, and that during this period land uses, urban planning and vulnerability experienced important changes. Potential changes in flood seasonality will be also considered. Early instrumental data collected on the framework of the European Project SPHERE and the Spanish National Project RAMSHES, between others and public information like 20th century reanalysis (Compo et al, 2011) will be also considered to reconstruct the meteorological patterns. Recent research on the impact of solar variability and teleconnections will be discussed, giving in mind the apparently contradictions between the dominant NAOI values during this period and the usual atmospheric circulation pattern associated to floods nowadays. Finally, a comparison with flood events recorded in the same

  5. EDITORIAL: Selected papers from the 22nd MicroMechanics and Microsystems Europe Workshop (MME 2011) Selected papers from the 22nd MicroMechanics and Microsystems Europe Workshop (MME 2011)

    NASA Astrophysics Data System (ADS)

    Ohlckers, Per

    2012-07-01

    three-axis gyroscopes as the most recent 'killer' application. Regardless of application, low cost, high performance and high reliability seem to give us the winning hand leaving competing technology platforms in the dust, for instance in automotive applications. First, I would like to thank the authors of the selected papers for each of their individual excellent contributions. My gratitude also goes to my fellow members in the programme committee (Leon Abelmann, Marin Hill and Martin Hoffmann) for their devotion in the selection of invited speakers and submitted papers, as well as the anonymous JMM reviewers for their careful selection of the final 13 papers included here. Last, but not least, it has been an honour and pleasure for me to collaborate with the editorial staff of Journal of Micromechanics and Microengineering, with the selected best papers presented at MME 2011 included in this special section. This collaboration will continue also for MME 2012, and hopefully also for many future MME workshops. References [1] Morante J R 1997 Preface J. Micromech. Microeng. 7 [2] Evans A G R 1998 Preface J. Micromech. Microeng. 8 [3] Ohlckers P 1999 Introduction J. Micromech. Microeng. 9 [4] Bosseboeuf A 2000 Editorial J. Micromech. Microeng. 10 [5] Hill M 2002 Preface J. Micromech. Microeng. 12 [6] Dascalu D and Muller A 2003 Preface J. Micromech. Microeng. 13 [7] Wolffenbuttel R F 2004 14th Micromechanics Europe Workshop (MME 2003) J. Micromech. Microeng. 14 [8] Puers R 2005 15th European Workshop on Micromechanics (MME 2004) J. Micromech. Microeng. 15 [9] Enoksson P 2006 16th European Workshop on Micromechanics (MME 2005) J. Micromech. Microeng. 16 [10] Morgan H 2007 The 17th European Workshop on Micromechanics (MME 2006) J. Micromech. Microeng. 17 [11] Correia J H 2008 The 18th European Workshop on Micromechanics (MME 2007) J. Micromech. Microeng. 18 060201 [12] Schnakenberg U 2009 The 19th MicroMechanics Europe Workshop (MME 2008) J. Micromech. Microeng. 19 070201

  6. [Portable pharmacies during the 19th century, starting from the example of Reichard' pharmacy in his guided for travelers in Europe (1805)].

    PubMed

    Bonnemain, Bruno

    2015-09-01

    The portable pharmacy of Reichard, in his 1805 Guide for travelers in Europe is an example among others of a growing determination to answer the needs of the people to have access to drugs even in absence of health care professionals. One can observe the ultimate result by looking at portable pharmacies offered for sale by companies such as Menier and Pharmacie Centrale de France, but also by individual pharmacists. In spite of favorable changes of health care in all countries during the XXe century, portable pharmacy and kits are still widely proposed for sale, on Internet for example, for frequent diseases, including for pets!

  7. EDITORIAL: Selected papers from the 20th Micromechanics Europe Workshop (MME 09) (Toulouse, France, 20-22 September 2009) Selected papers from the 20th Micromechanics Europe Workshop (MME 09) (Toulouse, France, 20-22 September 2009)

    NASA Astrophysics Data System (ADS)

    Pons, Patrick

    2010-06-01

    This special section of the Journal of Micromechanics and Microengineering is devoted to the 20th European Workshop on Micromechanics (MME 2009), which was held in Toulouse, France, 20-22 September 2009. The MME workshop series started in 1989 in Twente and was the first European event created in the field of micro machining technology for developing micro components, micro sensors, micro actuators, and micro systems. Over the last two decades the MEMS community has grown considerably, and the MME workshops have sustained this progress through annual meetings all around Europe: Twente (The Netherlands, 1989), Berlin (Germany, 1990), Leuven (Belgium, 1992), Neuchatel (Switzerland, 1993), Pisa (Italy, 1994), Copenhagen (Denmark, 1995), Barcelona (Spain, 1996), Southampton (United Kingdom, 1997), Ulvik (Norway, 1998), Gif-sur-Yvette (France, 1999), Uppsala (Sweden, 2000), Cork (Ireland, 2001), Sinaia (Romania, 2002), Delft (The Netherlands, 2003), Leuven (Belgium, 2004), Goteborg (Sweden, 2005), Southampton (United Kingdom, 2006), Guimaraes (Portugal, 2007) and Aachen (Germany, 2008). For twenty years, MME conferences have provided an excellent opportunity to bring together many, predominantly European, scientists and engineers to present and discuss the latest developments in this field. For the 20th anniversary of the MicroMechanics Europe Workshop, 115 papers from 23 countries were submitted. Selected contributions were presented during four poster sessions, including short oral presentations. A very interesting feature of the MME workshops is their ability to promote young researchers. Six invited speakers from research centres and industry also gave an overview on advanced technological, characterization and simulation tools. The two day workshop was attended by 185 delegates from 22 countries all over Europe, and from Japan, Taiwan, USA and Mexico. On behalf of the MME 2009 Program Committee, I would like to express my sincere gratitude to all authors of

  8. The 19th Project Integration Meeting

    NASA Technical Reports Server (NTRS)

    Mcdonald, R. R.

    1981-01-01

    The Flat-Plate Solar Array Project is described. Project analysis and integration is discussed. Technology research in silicon material, large-area silicon sheet and environmental isolation; cell and module formation; engineering sciences, and module performance and failure analysis. It includes a report on, and copies of visual presentations made at, the 19th Project Integration Meeting held at Pasadena, California, on November 11, 1981.

  9. Proceedings of the 19th International Conference on Ion Beam Modification of Materials (IBMM 2014)

    NASA Astrophysics Data System (ADS)

    Vantomme, André; Temst, Kristiaan

    2015-12-01

    It is our pleasure to present the proceedings of the 19th International Conference on Ion Beam Modification of Materials, which took place from September 14th until September 19th, 2014. The conference was held in the historic center of Leuven, a medieval city in the heart of Europe, a city where centuries-old culture meets frontier science and technology. Among other places, the conference brought us to the University Hall, which has been in use by the university since its foundation in 1425, to the Infirmerie of the Grand Beguinage and to the medieval city of Bruges, the latter two being Unesco World Heritage sites.

  10. Astronomical dating in the 19th century

    NASA Astrophysics Data System (ADS)

    Hilgen, Frederik J.

    2010-01-01

    Today astronomical tuning is widely accepted as numerical dating method after having revolutionised the age calibration of the geological archive and time scale over the last decades. However, its origin is not well known and tracing its roots is important especially from a science historic perspective. Astronomical tuning developed in consequence of the astronomical theory of the ice ages and was repeatedly used in the second half of the 19th century before the invention of radio-isotopic dating. Building upon earlier ideas of Joseph Adhémar, James Croll started to formulate his astronomical theory of the ice ages in 1864 according to which precession controlled ice ages occur alternatingly on both hemispheres at times of maximum eccentricity of the Earth's orbit. The publication of these ideas compelled Charles Lyell to revise his Principles of Geology and add Croll's theory, thus providing an alternative to his own geographical cause of the ice ages. Both Croll and Lyell initially tuned the last glacial epoch to the prominent eccentricity maximum 850,000 yr ago. This age was used as starting point by Lyell to calculate an age of 240 million years for the beginning of the Cambrium. But Croll soon revised the tuning to a much younger less prominent eccentricity maximum between 240,000 and 80,000 yr ago. In addition he tuned older glacial deposits of late Miocene and Eocene ages to eccentricity maxima around 800,000 and 2,800,000 yr ago. Archibald and James Geikie were the first to recognize interglacials during the last glacial epoch, as predicted by Croll's theory, and attempted to tune them to precession. Soon after Frank Taylor linked a series of 15 end-moraines left behind by the retreating ice sheet to precession to arrive at a possible age of 300,000 yr for the maximum glaciation. In a classic paper, Axel Blytt (1876) explained the scattered distribution of plant groups in Norway to precession induced alternating rainy and dry periods as recorded by the

  11. Women in 19th Century Irish immigration.

    PubMed

    Jackson, P

    1984-01-01

    By the 1950s--100 years after the great famine of 1845-49-- 57% of emigrants from the 26 countries of Ireland were women. In the latter 1/2 of the 19th Century, increasing proportions of women emigrated, until they outnumbered men. For women it was more than a flight from poverty. It was also an escape from an increasingly patriarchal society, whose asymetrical development as a colony curtailed women's social space, even in their traditional role as wife and mother. The famine, which is the single greatest influence forcing emigration, undermined the social fabric of an agrarian society, hastening the process of agricultural transformation. The growth of a new class of Irish a British grazier landlords resulted in a situation of acute land scarcity, encouraging tendencies to cling to one's land holding without dividing it. This, combined with new inheritance practices, gave rise to widespread arranged marriages as a means of land consolidation, and the dowry system. The spontaneous marriage practices of famine days also were replaced by a postponement of marriage. These trends severely reduced the choices exerted by women. The absence of big industrialized cities, which might have absorbed displaced rural populations, removed available options, particularly for women. The system of land monopoly and inheritance revolving around male heads of households reinforced partriarchal relations, within a framework of rigid sexual norms, whose enforcement was easy because the church, which played an important role in the emergence of these values, was a major landowner in itself. The subordinated, invisible status of women in post-famine Ireland, and growing barriers to easy access to marriage partners, to waged employment and self-expression, all helped ensure the higher and higher emigration rates of women. The economic transformation of Irish agriculture accelerated the establishment of oppressive values and helped depreciate the position of women to a very low level. The

  12. [Origin of animal experimentation legislation in the 19th century].

    PubMed

    Pocard, M

    1999-01-01

    The first legislation in the world, designed to protect animals used in research, was passed in England in 1876, and is still in force today. It is one of the strictest in Europe. At the same period, France had no such law, and was the country conducting the greatest amount of animal experimentation. Comparing, these two countries, in the middle of the 19th century, can account for this difference. The most important difference seems to be related to the theological question: are animals endowed with a soul? Saint Augustine, claimed, in the 4th century, perhaps because of an experiment with the centipede, that animals do not have a soul. In the 17th century, René Descartes, using a different philosophical system, reached a similar conclusion, in France. On the other hand, under the influence of Charles Darwin, England rejected the Roman Catholic conclusion, about the soul of animals. The industrial revolution, occurring earlier in England than in France, also changed the society, developing urban areas, where people were cut off from rural life and changing human relationships with animals. The industrial revolution enabled the development of the press, giving impetus to public opinion. These facts, combined with a caution of science, which was more developed in England than in France, brought about the first important "anti-doctor" campaign.

  13. Selected papers from the 23rd MicroMechanics and Microsystems Europe Workshop (MME 2012) (Ilmenau, Germany, September 9-12, 2012)

    NASA Astrophysics Data System (ADS)

    Hoffmann, Martin

    2013-07-01

    In September 2012, the 23rd MicroMechanics Europe Workshop (MME) took place in Ilmenau, Germany. With about 120 participants from 20 countries and 76 accepted presentations, the workshop series turned out to be a successful platform for young scientists to present their work to our scientific community. Traditionally, the interaction is an important aspect of this workshop: while short presentations introduce the posters, an extended poster session allows intensive discussion which is quite useful to the participants. The discussion very often extends into the breaks and the evening events. It is also encouraging for them that the best presentations are selected and invited to submit a full paper to this journal. Thanks to the support of IOP Publishing, this next logical step to present work to the scientific world is made possible. In this issue, you can find the best papers that have been selected by a committee during the workshop taking the written workshop contribution, the poster and the presentation into account. Again, all areas of micromechanics from new technology developments up to systems integration were presented at the workshop at different levels of completion. The selected papers present those results which are almost complete. Nevertheless, it is nice to see that in some cases topics grow over the years from 'nice ideas' to realized system concepts. And although this is the 23rd workshop, it is clear that micromechanics is a topic that is not running short of new ideas. First, I would like to thank the authors of the selected papers for each of their individual excellent contributions. My gratitude also goes to my fellow members in the programme committee (Per Ohlckers, Martin Hill and Sami Franssila) for their cooperation in the selection of invited speakers and submitted papers, as well as the anonymous Journal of Micromechanics and Microengineering (JMM) reviewers for their careful selection of the final papers presented here. Last, but not

  14. Technical improvements in 19th century Belgian window glass production

    NASA Astrophysics Data System (ADS)

    Lauriks, Leen; Collette, Quentin; Wouters, Ine; Belis, Jan

    Glass was used since the Roman age in the building envelope, but it became widely applied together with iron since the 19th century. Belgium was a major producer of window glass during the nineteenth century and the majority of the produced window glass was exported all over the world. Investigating the literature on the development of 19th century Belgian window glass production is therefore internationally relevant. In the 17th century, wood was replaced as a fuel by coal. In the 19th century, the regenerative tank furnace applied gas as a fuel in a continuous glass production process. The advantages were a clean production, a more constant and higher temperature in the furnace and a fuel saving. The French chemist Nicolas Leblanc (1787-1793) and later the Belgian chemist Ernest Solvay (1863) invented processes to produce alkali out of common salt. The artificial soda ash improved the quality and aesthetics of the glass plates. During the 19th century, the glass production was industrialized, influencing the operation of furnaces, the improvement of raw materials as well as the applied energy sources. Although the production process was industrialized, glassblowing was still the work of an individual. By improving his work tools, he was able to create larger glass plates. The developments in the annealing process followed this evolution. The industry had to wait until the invention of the drawn glass in the beginning of the 20th century to fully industrialise the window glass manufacture process.

  15. Vocational Education in the 19th Century American Academy.

    ERIC Educational Resources Information Center

    Law, Gordon F.

    The phrase "all things useful and all things ornamental," coined by Benjamin Franklin, describes the stated mission of most of the approximately 6,000 educational academies flourishing in America in the mid-19th century. Built upon the roots of Latin grammar schools, the academies evolved to include courses in many areas, from classical…

  16. Woman Suffrage and the 19th Amendment. Teaching with Documents.

    ERIC Educational Resources Information Center

    National Archives and Records Administration, Washington, DC.

    Beginning in the mid-19th century, several generations of woman suffrage supporters lectured, wrote, marched, lobbied, and practiced civil disobedience to achieve what many people considered a radical change in the U.S. Constitution. Militant suffragists used tactics such as parades, silent vigils, and hunger strikes. In 1870 the 15th amendment to…

  17. Computational micromechanics

    NASA Astrophysics Data System (ADS)

    Ortiz, M.

    1996-09-01

    Selected issues in computational micromechanics are reviewed, with particular emphasis on multiple-scale problems and micromechanical models of material behavior. Examples considered include: the bridging of atomistic and continuum scales, with application to nanoindentation and the brittle-to-ductile transition; the development of dislocation-based constitutive relations for pure metallic crystals and intermetallic compounds, with applications to fracture of single crystals and bicrystals; the simulation of non-planar three-dimensional crack growth at the microscale, with application to mixed mode I III effective behavior and crack trapping and bridging in fiber-reinforced composites; and the direct micromechanical simulation of fragmentation of brittle solids and subsequent flow of the comminuted phase.

  18. [Popular knowledge about medicaments in 19th century periodicals].

    PubMed

    Arabas, Iwona

    2004-01-01

    Polish periodicals published since the beginning of 19th century contained household knowledge which was of great importance to peasants. In the second half of 19th century the number of articles related to prevention, treatment as well as life hygiene (including nutrition guidance) enlarged significantly. The term "household medicine box# was very often used in periodicals as titles of both: sections dedicated to hygiene or medicine as well as for articles describing medicaments intended to be kept in the boxes. Articles referenced law regulations stated in "law for pharmacists and pharmacies# from 1844. The availability of medical handbooks widened with the end of the century and this fact may have caused the changes in profiles of numerous medical sections in popular periodicals. However the changes did not affect publications related to contents of medical boxes.

  19. A comparison of 19th century and current attitudes to female sexuality.

    PubMed

    Studd, John

    2007-12-01

    The 19th century medical attitude to normal female sexuality was cruel, with gynecologists and psychiatrists leading the way in designing operations for the cure of the serious contemporary disorders of masturbation and nymphomania. The gynecologist Isaac Baker Brown (1811-1873) and the distinguished endocrinologist Charles Brown-Séquard (1817-1894) advocated clitoridectomy to prevent the progression to masturbatory melancholia, paralysis, blindness and even death. Even after the public disgrace of Baker Brown in 1866-7, the operation remained respectable and widely used in other parts of Europe. This medical contempt for normal female sexual development was reflected in public and literary attitudes. Or perhaps it led and encouraged public opinion. There is virtually no novel or opera in the last half of the 19th century where the heroine with 'a past' survives to the end. H. G. Wells's Ann Veronica and Richard Strauss's Der Rosenkavalier, both of which appeared in 1909, broke the mould and are important milestones. In the last 50 years new research into the sociology, psychology and physiology of sexuality has provided an understanding of decreased libido and inadequate sexual response in the form of hypoactive sexual desire disorder. This is now regarded as a disorder worthy of treatment, either by various forms of counseling or by the use of hormones, particularly estrogens and testosterone.

  20. [Suicide and cultural criticism in 19th century Spanish medicine].

    PubMed

    Plumed Domingo, José Javier; Novella, Enric J

    2015-01-01

    This paper explores the major role of suicide in the cultural criticism deployed by 19th century Spanish doctors by analysing the most important theoretical models that inspired their contributions to its aetiology. In the first half of the century, the most commonly debated causal factor was the passions, which were thought to stand in a permanent tension with a free, reflexive and conscious self, in accordance with the spiritualist doctrine that was then dominant. In the context of a growing somatisation of moral and intellectual phenomena, the notion of suicide as an act of free will was later modified, and it became considered the consequence of certain organic disturbances. However, this process did not alter the central role of suicidal behaviour within 19th-century cultural criticism, because the advent of degeneration theory meant that doctors finally had a doctrine that allowed them to combine biological determinism with the extended perception of a moral and social crisis threatening the stability and achievements of bourgeois society.

  1. [The advent of a newborn specialty: 19th century pediatrics].

    PubMed

    Baudon, Jean-Jacques

    2017-04-05

    Pediatrics began under the most unfavorable conditions that are difficult to imagine nowadays. Children at the start of the 19th century were considered as negligible. The death rate was tremendous, increased by the work of children in factories as soon as 6 years of age in textile industries. In upper classes, infants were fed by a wet nurse, far from their parents and death rate was high as well. The emergence of pediatrics was the result of work carried out in adult medicine in the first half of the 19th century: clinical anatomic method, knowledge of contagious diseases even before the discovery of bacteria, birth of bacteriology. During the whole century, infectious diseases contributed in a large part to children mortality, as that of adults, by cholera, typhus, variola, diphtheria, measles and tuberculosis. Progresses noted during the 2nd part of the century resulted from beginning of hygiene, antisepsis, nutrition improvement, taking consideration of children as human being asking for protection. In contrast, therapeutics as serotherapy, vaccinations at the break of the 20th century played a secondary role.

  2. [The technicalization of medicine in the 19th century].

    PubMed

    Olsén, J E

    2001-01-01

    The paper focuses on the role that instruments played in the medical discourse of the 19th century. Towards the end of the century, instruments had imbued the medical sciences to such an extent that the situation soon was compared to the vernacular confusion of the biblical tower of Babel. Whereas the autonomical recordings of laboratory apparatus, vouched for guarantee against biased test results, clinicians and general practitioners were finding it difficult to incorporate the new techniques into their daily routines. A tension between the instrument as invention, moulded to fit a particular series of experiments, and the instrument as a reproducible item, was inevitable. Hence, the unification of the science and practice of medicine, became an important topic at the international medical meetings of the late 19th century. Seen in the light of the industrialization and urbanization of occidental culture and society, the instrumentation of medicine entailed a number of significant issues which hinged on the relationship between the biological destiny of man and the artificial wonders of technology. Grand metaphors like the organic machine and the human motor, did not only signal a scientific preoccupation with the shortcomings of the living organism as opposed to the perfection of the machine, but also indicated closer ties between the human body and technology at large. In a certain sense, medical instruments, along with apparatuses such as the camera, the steam-engine, the telegraph, the phonograph and the cinematograph, offered a new set-up of codes with which the body and its functions could be reinterpreted. In this respect, the late nineteenth-century strive for the standardisation and unification of medical instruments, was not irreconcilable with the notion of the l'homme moyen, as conceived, for example, in the work of the Belgian mathematician Adolphe Quetelet. The paper outlines the span of medical measuring devices, dating from the sphygmometer of

  3. Florence Nightingale. A 19th-century mystic.

    PubMed

    Dossey, B M

    1998-06-01

    Florence Nightingale (1820-1910) received a clear and profoundly moving Call to serve God at the age of 16. Through a lifetime of hard work and discipline, she became a practicing mystic in the Western tradition, thereby becoming an instrument of God's love, which was the primary source of her great energy and the fabled "Nightingale power." To understand the life and work of this legendary healer, who forever changed human consciousness, the role of women, and nursing and public health systems in the middle of the 19th century, it is necessary to understand her motivation and inspiration. The purpose of this article is to discuss her life and work in the context of her mystical practice and to show the parallels between her life and the lives of three recognized women mystics.

  4. Cholera in Haiti and Other Caribbean Regions, 19th Century

    PubMed Central

    Szabo, Victoria

    2011-01-01

    Medical journals and other sources do not show evidence that cholera occurred in Haiti before 2010, despite the devastating effect of this disease in the Caribbean region in the 19th century. Cholera occurred in Cuba in 1833–1834; in Jamaica, Cuba, Puerto Rico, St. Thomas, St. Lucia, St. Kitts, Nevis, Trinidad, the Bahamas, St. Vincent, Granada, Anguilla, St. John, Tortola, the Turks and Caicos, the Grenadines (Carriacou and Petite Martinique), and possibly Antigua in 1850–1856; and in Guadeloupe, Cuba, St. Thomas, the Dominican Republic, Dominica, Martinique, and Marie Galante in 1865–1872. Conditions associated with slavery and colonial military control were absent in independent Haiti. Clustered populations, regular influx of new persons, and close quarters of barracks living contributed to spread of cholera in other Caribbean locations. We provide historical accounts of the presence and spread of cholera epidemics in Caribbean islands. PMID:22099117

  5. JANNAF 19th Propulsion Systems Hazards Subcommittee Meeting. Volume 1

    NASA Technical Reports Server (NTRS)

    Cocchiaro, James E. (Editor); Kuckels, Melanie C. (Editor)

    2000-01-01

    This volume, the first of two volumes is a compilation of 25 unclassified/unlimited-distribution technical papers presented at the Joint Army-Navy-NASA-Air Force (JANNAF) 19th Propulsion Systems Hazards Subcommittee (PSHS) meeting held jointly with the 37th Combustion Subcommittee (CS) and 25th Airbreathing Propulsion Subcommittee (APS), and 1st Modeling and Simulation Subcommittee (MSS) meetings. The meeting was held 13-17 November 2000 at the Naval Postgraduate School and Hyatt Regency Hotel, Monterey, California. Topics covered at the PSHS meeting include: impact and thermal vulnerability of gun propellants; thermal decomposition and cookoff behavior of energetic materials; violent reaction and detonation phenomena of solid energetic materials subjected to shock and impact loading; and hazard classification, and insensitive munitions testing of propellants and propulsion systems.

  6. Foam Micromechanics

    SciTech Connect

    Kraynik, A.M.; Neilsen, M.K.; Reinelt, D.A.; Warren, W.E.

    1998-11-03

    Foam evokes many different images: waves breaking at the seashore, the head on a pint of Guinness, an elegant dessert, shaving, the comfortable cushion on which you may be seated... From the mundane to the high tech, foams, emulsions, and cellular solids encompass a broad range of materials and applications. Soap suds, mayonnaise, and foamed polymers provide practical motivation and only hint at the variety of materials at issue. Typical of mukiphase materiaIs, the rheoIogy or mechanical behavior of foams is more complicated than that of the constituent phases alone, which may be gas, liquid, or solid. For example, a soap froth exhibits a static shear modulus-a hallmark of an elastic solid-even though it is composed primarily of two Newtonian fluids (water and air), which have no shear modulus. This apparent paradox is easily resolved. Soap froth contains a small amount of surfactant that stabilizes the delicate network of thin liq- uid films against rupture. The soap-film network deforms in response to a macroscopic strain; this increases interracial area and the corresponding sur- face energy, and provides the strain energy of classical elasticity theory [1]. This physical mechanism is easily imagined but very challenging to quantify for a realistic three-dimensional soap froth in view of its complex geome- try. Foam micromechanics addresses the connection between constituent properties, cell-level structure, and macroscopic mechanical behavior. This article is a survey of micromechanics applied to gas-liquid foams, liquid-liquid emulsions, and cellular solids. We will focus on static response where the foam deformation is very slow and rate-dependent phenomena such as viscous flow can be neglected. This includes nonlinear elasticity when deformations are large but reversible. We will also discuss elastic- plastic behavior, which involves yield phenomena. Foam structures based on polyhedra packed to fill space provide a unify- ing geometrical theme. Because a two

  7. [Gymnastics and therapeutic gymnastics in 19th century Hungary].

    PubMed

    Kölnei, Lívia

    2009-01-01

    Gymnastics as a way of healing and of preserving health spread in Hungary--almost exclusively among higher classes--only in the first half of the 19th century. The movement was inspired by naturopathic theories of the time, first of all by Christoph Wilhelm Hufeland's macrobiotics, by Vinzenz Priessnitz's hydrotherapy and by his healing gymnastics. Gymnastics has been utilized from the 30ies by a new bough of medicine, orthopaedy. The so called Swedish Gymnastics invented by Per Henrik Ling and by his son Hjalmar Ling or the method of the German gymnast Adolf Spiess were well known in Hungary as well. The pediatrist Agost Schöp-Merei founded the first Institute for Gymnastics in Pest in 1835. As orthopaedy developed, gymnastics was more and more utilized in curing locomotor disorders. Gymnastics however stood in close connection with hydropathy as well. Several institutes for hydropathy and gymnastics were founded in the 50ies and 60ies throughout the country. The most popular of them were those of Károly Siklósy and Sámuel Batizfalvy. Preventive gymnastics gained popularity only in the second half of the 19th century, as 1830 the French gymnast Ignatius Clair moved to Pest and founded the "Pester gymnastische Schule" (Gymnastics School of Pest). This private school flourished till 1863. The Gymnastic Federation of Pest (later National Gymnastics Federation), the first Hungarian sport club was founded in 1866. Tivadar Bakody played an important role in its creation. Gymnastics and sport at the beginning were closely connected with fire-service, so gymnastics clubs often functioned also as fire-guard-bodies. In the 70ies and 80ies the social basis of sport movement was slowly broadened out. The end of the century saw already 44 gymnastics-clubs in Hungary united in a single union, the National Federation of Gymnasts, which organized the education of the profession as well. The trend of development didn't cease up to the Great War. This time the movement was

  8. Science Fiction In Naples In The Middle Of The 19th Century

    NASA Astrophysics Data System (ADS)

    Capaccioli, Massimo; Cirella, Emilia Olostro; Stendardo, Enrica; Virgilio, Nicla

    Astronomer, intellectual, passionate patriot, and refined humanist, Ernesto Capocci Belmonte (Picinisco, May 31, 1798 - Naples, January 6, 1864) was a prominent figure of the scientific, cultural, and political life in Naples around the middle of the 19th century. He acquired international recognition for his studies on the orbits of comets and, since 1833, he was named director of the newly built Osservatorio Astronomico in Capodimonte: A prestigious position that he lost for political retaliation as a result of his participation in the movement against the Bourbon rulers in 1848, but which he regained in 1860 upon the arrival in Naples of Giuseppe Garibaldi. An intuitive and open-minded scholar, he looked always at the contemporary experiences in Europe and, as a scientist and cultivated human being, he sought to serve the community by enthusiastically devoting himself also to education and public outreach. He developed clear interests in literature and, as a forerunner, he dared to tackle the genre of science fiction. His short novel Relazione del viaggio alla Luna fatto da una donna nell'anno di grazia 2057 (Report of the Trip to the Moon done by a Woman in the Year of our Lord 2057), written in the period of his exile from the Observatory and practically given up as lost until a private copy was found in the library of one of Capocci's descendants, offers an interesting overview of astronomical knowledge and taste for the elegance in writing, and gives an unusual, and often ironic, viewpoint on the situation of sciences in Naples in the middle of the 19th century.

  9. "Depressive pseudodementia" or "Melancholic dementia": a 19th century view.

    PubMed Central

    Berrios, G E

    1985-01-01

    Nineteenth century views on the interaction between dementia, depressive illness, general paralysis and brain localisation are discussed in the context of a book by A Mairet entitled: Melancholic Dementia. It is shown that by 1883 there was already awareness of the fact that severe affective disorder could lead to cognitive impairment. General paralysis was the commonest diagnosis put forward to account for patients with depression who went on to develop dementia. Patients so diagnosed, however, often recovered and clinical and statistical analysis of Mairet's case histories suggests that some were in fact suffering from depressive pseudodementia. Evidence is marshalled to show that during the 19th century there was wide disagreement concerning the clinical domain, course and even histopathology of general paralysis. This casts doubt on the traditional view that this condition served as "a paradigm" for other psychiatric diseases during this period. It is shown that by the turn of the century these difficulties led to a redefinition of the concept of dementia and to a marked narrowing of the clinical bounds of general paralysis. PMID:3889224

  10. Austrian pharmacy in the 18 and 19th century.

    PubMed

    Kletter, Christa

    2010-01-01

    This overview reflects the extensive changes in the health care system which had significant effects on the apothecaryâs profession and education. In the 18(th) century Maria Theresia assigned Gerard van Swieten to modernize the medical curriculum and to work out reforms for health care. The resulting sanitary bill released in 1770 and amended in 1773 became effective for the whole empire and influenced greatly the apothecaryâs profession. The Viennese Medical Faculty continued to be the supervisory body for the apothecaries, a situation which prolonged the conflicts between the faculty and the apothecaries. The financial and social distress prevalent in the 19(th) century also affected the apothecary business and led to a crisis of the profession. Furthermore, the apothecariesâ missing influence over the sanitary authorities delayed the release of a badly needed new apothecary bill until 1906. The introduction of a specific pharmaceutical curriculum at the university in 1853 was a great step forward to improve the pharmaceutical education. Nevertheless, the secondary school exam was not compulsory for the studies until 1920 and, therefore, the graduates were not on a par with other university graduates before that date. Women, except nuns, were not allowed to work as pharmacists until 1900.

  11. Faces and Photography in 19th-Century Visual Science.

    PubMed

    Wade, Nicholas J

    2016-09-01

    Reading faces for identity, character, and expression is as old as humanity but representing these states is relatively recent. From the 16th century, physiognomists classified character in terms of both facial form and represented the types graphically. Darwin distinguished between physiognomy (which concerned static features reflecting character) and expression (which was dynamic and reflected emotions). Artists represented personality, pleasure, and pain in their paintings and drawings, but the scientific study of faces was revolutionized by photography in the 19th century. Rather than relying on artistic abstractions of fleeting facial expressions, scientists photographed what the eye could not discriminate. Photography was applied first to stereoscopic portraiture (by Wheatstone) then to the study of facial expressions (by Duchenne) and to identity (by Galton and Bertillon). Photography opened new methods for investigating face perception, most markedly with Galton's composites derived from combining aligned photographs of many sitters. In the same decade (1870s), Kühne took the process of photography as a model for the chemical action of light in the retina. These developments and their developers are described and fixed in time, but the ideas they initiated have proved impossible to stop.

  12. Laser cleaning of 19th century Congo rattan mats

    NASA Astrophysics Data System (ADS)

    Carmona, N.; Oujja, M.; Roemich, H.; Castillejo, M.

    2011-09-01

    There is a growing interest by art conservators for laser cleaning of organic materials, such as wooden artworks, paper and textiles, since traditional cleaning with solvents can be a source of further decay and mechanical cleaning may be too abrasive for sensitive fibers. In this work we present a successful laser cleaning approach for 19th century rattan mats from the Brooklyn Museum collection of African Art, now part of the study collection at the Conservation Center in New York. Tests were carried out using the fundamental (1064 nm) and second harmonic (532 nm) wavelength of a Q-switched Nd:YAG laser to measure threshold values both for surface damage and color changes for different types of rattan samples. The irradiated substrates were investigated by optical microscopy, scanning electron microscopy and by UV-vis spectroscopy in order to determine the efficiency of laser cleaning and to assess possible deterioration effects that may have occurred as a result of laser irradiation. The study showed that by using the laser emission at 532 nm, a wavelength for which photon energy is below the bond dissociation level of the main cellulosic compounds and the water absorption is negligible, it is possible to select a range of laser fluences to remove the black dust layer without damaging the rattan material.

  13. Florence Nightingale: a 19th-century mystic.

    PubMed

    Dossey, Barbara M

    2010-03-01

    Florence Nightingale (1820-1910) received a clear and profoundly moving Call to serve God at the age of 16. Through a lifetime of hard work and discipline, she became a practicing mystic in the Western tradition, thereby becoming an instrument of God's love, which was the primarily source of her great energy and the fabled "Nightingale power." To understand the life and work of this legendary healer, who forever changed human consciousness, the role of women, and nursing and public health systems in the middle of the 19th century, it is necessary to understand her motivation and inspiration. This article will discuss her life and work in the context of her mystical practice and to show the parallels between her life and the lives of three recognized women mystics. In her epic Crimean war mission (1854-1856) of leading and directing women nurses in the army hospital at Scutari, Turkey, Florence Nightingale burst into world consciousness as a spiritual beacon of hope and compassion for all who suffered. Her historic breakthrough achievement--pioneering the modern administrative role of nurse superintendent with measurable outcomes supported by irrefutable data--in the face of incredible adversity was merely the cornerstone of her life work.

  14. William Prout: early 19th century physician-chemist.

    PubMed

    Rosenfeld, Louis

    2003-04-01

    In the early 19th century, the discoveries of new substances in the healthy and diseased body spawned a search for chemical explanations for physiologic phenomena to guide medical diagnosis and control therapy. William Prout's work on the nature and treatment of diseases of the urinary organs established his reputation as one of Britain's most distinguished physiological chemists. Prout was very skeptical of chemical remedies because of possible side effects, but he suggested iodine treatment for goiter. He emphasized that a satisfactory diet should include carbohydrates, fats, protein, and water. In 1824, he showed that the acid of the gastric juice was hydrochloric acid. Prout applied chemical methods and reasoning to physiology and was criticized for his view that the body's vital functions could be explained by chemistry. His remedy for lack of progress in animal chemistry was for physiologists to become chemists. Prout stimulated much discussion on atomic theory by his hypothesis that the atomic weights of all chemical elements are whole-number multiples of the atomic weight of hydrogen and that the chemical elements were condensed from hydrogen atoms.

  15. The Lowland Rivers of The Netherlands - Geodiversity and Cultural Heritage on 19th and early 20th century Landscape Paintings

    NASA Astrophysics Data System (ADS)

    Jungerius, Pieter Dirk; van den Ancker, Hanneke; Moes, Constance

    2015-04-01

    One of the major Dutch landscapes is formed by lowland rivers. They divide the country in a southern and a northern part, both physically and culturally. We screened the freely available database of 19th and early 20th century paintings of Simonis & Buunk, www.simonis-buunk.com, looking for lowland river landscapes depicting geodiversity and cultural heritage relationships (See References for other landscapes). Emperor Napoleon declared The Netherlands as naturally belonging to his empire as its lands originated from muds originating in France and transported there by the big rivers. A description that may have given rise to the idea of the Netherlands as a delta, but from a geomorphological perspective The Netherlands consists of series of river plains of terrestrial origin, of which the north-western part are subsiding and invaded by the sea. Now, the rivers Meuse and Rhine (including its branches Waal and IJssel) meander through ever larger river plains before reaching the North Sea. They end in estuaries, something one would not expect of rivers with catchments discharging a large part of Western Europe. Apart from the geological subsidence, the estuaries might be due to human interference, the exploitation of peat and building of dikes since the 11th century, heavy storms and the strong tidal currents. Archaeological finds show Vikings and Romans already used the river Rhine system for trading and transporting goods. During the Roman Empire the Rhine was part of The Limes, the northern defence line of the empire. Romans already influenced the distribution of water over the different river branches. Since the middle of the 19th century groins and canalization drastically changed the character of the rivers. The 19th and early 20th century landscape paintings illustrate this change as well as changes in land use. Examples of geodiversity and cultural heritage relationships shown: - meanders and irregular banks disappear as river management increases, i.a. bends

  16. [Developments in neurophysiology in the 19th century].

    PubMed

    Hess, C W

    1994-04-19

    The rise of neurophysiology in the 19th century was kindled by Luigi Aloysius Galvani's revolutionary claim for animal electricity at the end of the preceding century. He was first challenged by Allessandro Giuseppe Antonio Anastasio Volta who showed that the muscle twitch in Galvani's experiment was the result of electric stimulation rather than of an enabled biological current. The controversy between Galvani and Volta became a predominant and stimulating issue among the scientists of the early century and found its ultimate elucidation only 40 years later by the pioneering work of Carlo Matteucci of Pisa and Emil Heinrich Du Bois-Reymond of Berlin, who both deserve the reknown as founders of modern neurophysiology. As the first influential promoter and mastermind of the experimental physiology, François Magendie of Paris primarily investigated the nervous system and inaugurated the lesion experiments to clarify specific functions of neural structures. Johannes Müller founded the German school of physiology with its eminent neurophysiological offspring: Du Bois-Reymond, Hermann Ludwig Ferdinand von Helmholtz, and Eduard Friedrich Wilhelm Pflüger. It was Helmholtz's merit to have for the first time precisely assessed the motor conduction velocity by measuring the time interval between two different stimulation sites of the sciatic nerve of the frog. In their brilliant work published in 1870 Gustav Theodor Fritsch and Eduard Hitzig demonstrated that appropriately located focal electrical stimulation of the exposed cortex of dogs induces movement of the contralateral limbs and unequivocally disproved the then prevailing dogma of holistic capacity of the hemispheres, which denied localised functions within the cortex.(ABSTRACT TRUNCATED AT 250 WORDS)

  17. [Earth magnetism research in the 19th century].

    PubMed

    Schröder, W; Wiederkehr, K H

    2000-01-01

    Even before the discovery of the electromagnetism by Oersted, and before Ampère, who attributed all magnetism to the flux of electrical currents, A. v. Humboldt and Hansteen had turned to geomagnetism. With the help of the "Göttinger Magnetische Verein", a worldwide cooperation under the leadership of Gauss game into existence. Even today, Gauss' theory of the geomagnetism is one of the pillars for geomagnetical research work. Thereafter, J. v. Lamont, Prof. in Munich, took over the leadership in Germany. In England, the Magnetic Crusade was started by the initiative of John Herschel and E. Sabine. At the beginning of the forties, James Clarke Ross advanced to the Antarctic Continent, which was then quite unknown. Ten years later, Sabine was able to gather solar-terrestrial relations from the data of the colonical observatories. In the eighties, Arthur Schuster, following Balfour Stewart's ideas, succeeded in interpreting the daily variations of the electrical process in the high atmosphere. The geomagnetic research work in Germany was given a fresh impetus by the First Polar Year 1882-1883. Georg Neumayer, director of the "Deutsche Seewarte" in Hamburg, had been one of the initiators of the Polar Year. He had a close cooperation with the newly founded "Kaiserliches Marineobservatorium" in Wilhelmshaven, and he also managed to gain the collaboration of the "Gauss-Observatorium für Erdmagnetismus" in Göttingen under E. Schering. In the Polar Year, the first automatic recording magnetometers (Kew-Model) were used in a German observatory in Wilhelmshaven. Here M. Eschenhagen, who later became director of the geomagnetic section in the new Meterological-Magnetic Observatory in Potsdam, gained special merit. The treatise considers preceding hypotheses of geomagnetism as well as the palaeomagnetic studies. The essential seismological investigations at the turn of the 19th to the 20th century are briefly treated. They represent one of the keystones for the modern

  18. Absinthism: a fictitious 19th century syndrome with present impact

    PubMed Central

    Padosch, Stephan A; Lachenmeier, Dirk W; Kröner, Lars U

    2006-01-01

    Absinthe, a bitter spirit containing wormwood (Artemisia absinthium L.), was banned at the beginning of the 20th century as consequence of its supposed unique adverse effects. After nearly century-long prohibition, absinthe has seen a resurgence after recent de-restriction in many European countries. This review provides information on the history of absinthe and one of its constituent, thujone. Medical and toxicological aspects experienced and discovered before the prohibition of absinthe are discussed in detail, along with their impact on the current situation. The only consistent conclusion that can be drawn from those 19th century studies about absinthism is that wormwood oil but not absinthe is a potent agent to cause seizures. Neither can it be concluded that the beverage itself was epileptogenic nor that the so-called absinthism can exactly be distinguished as a distinct syndrome from chronic alcoholism. The theory of a previous gross overestimation of the thujone content of absinthe may have been verified by a number of independent studies. Based on the current available evidence, thujone concentrations of both pre-ban and modern absinthes may not have been able to cause detrimental health effects other than those encountered in common alcoholism. Today, a questionable tendency of absinthe manufacturers can be ascertained that use the ancient theories of absinthism as a targeted marketing strategy to bring absinthe into the spheres of a legal drug-of-abuse. Misleading advertisements of aphrodisiac or psychotropic effects of absinthe try to re-establish absinthe's former reputation. In distinction from commercially manufactured absinthes with limited thujone content, a health risk to consumers is the uncontrolled trade of potentially unsafe herbal products such as absinthe essences that are readily available over the internet. PMID:16722551

  19. Ottoman Greek Education System and Greek Girls' Schools in Istanbul (19th and 20th Centuries)

    ERIC Educational Resources Information Center

    Daglar Macar, Oya

    2010-01-01

    Modernization efforts in education, which were initiated in the 19th century, can be seen as forerunners of the modernization attempts in the Republic period. In this article, Greek education system in the Ottoman Empire will be discussed and the effects and importance of the changes observed in Greek girls' education in 19th and 20th centuries on…

  20. Reading for Moral Progress: 19th Century Institutions Promoting Social Change. Occasional Papers No. 207.

    ERIC Educational Resources Information Center

    Davis, Donald G., Jr.; And Others

    The three papers in this document examine the motives behind the collecting and loaning of publications in the 19th century. They describe the effects of three discrete movements designed to assist religious, military, and academic endeavors. The first paper, "Bread Upon the Waters: The Printed Word in Sunday Schools in 19th Century England…

  1. Whooping Cough: A Brief History to the 19th Century.

    PubMed

    Weston, Robert

    2012-01-01

    This paper examines the history of whooping cough (pertussis) from its first recorded mention in 1190 to the time when its microbial cause was identified. The historical records of the disease are complicated by the variation in the nomenclature employed and through using the same name for disorders with different symptoms. During the early-modern period it was considered to be a disease new to Europe-contagious, dangerous, and potentially epidemic. Believed to be confined to children, its significance was limited until the 18th century when its incidence increased markedly. This essay argues pertussis may have occurred in the late medieval period in individual, though not epidemical, cases.

  2. [JAN JĘDRZEJEWICZ AND EUROPEAN ASTRONOMY OF THE 2ND HALF OF THE 19TH CENTURY].

    PubMed

    Siuda-Bochenek, Magda

    2015-01-01

    Jan Jędrzejewicz was an amateur astronomer who in the 2nd half of the 19th century created an observation centre, which considering the level of research was comparable to the European ones. Jędrzejewicz settled down in Plonsk in 1862 and worked as a doctor ever since but his greatest passion was astronomy, to which he dedicated all his free time. In 1875 Jędrzejewicz finished the construction of his observatory. He equipped it with basic astronomical and meteorological instruments, then began his observations and with time he became quite skilled in it. Jędrzejewicz focused mainly on binary stars but he also pointed his telescopes at the planets of the solar system, the comets, the Sun, as well as all the phenomena appearing in the sky at that time. Thanks to the variety of the objects observed and the number of observations he stood out from other observers in Poland and took a very good position in the mainstream of the 19th-century astronomy in Europe. Micrometer observations of binary stars made in Płońsk gained recognition in the West and were included in the catalogues of binary stars. Interest in Jędrzejewicz and his observatory was confirmed by numerous references in the English "Nature" magazine.

  3. 4. LOOKING NORTHEAST TOWARDS LOCKS. 19TH CENTURY GRAVITY LOCKS ON ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. LOOKING NORTHEAST TOWARDS LOCKS. 19TH CENTURY GRAVITY LOCKS ON RIGHT. 20TH CENTURY ELECTRIC LIFT LOCKS ON LEFT. - New York State Barge Canal, Lockport Locks, Richmond Avenue, Lockport, Niagara County, NY

  4. The Electric Whirl in the 19th and 21st Centuries

    NASA Astrophysics Data System (ADS)

    Daffron, John A.; Greenslade, Thomas B.

    2012-12-01

    The electric whirl or electric fly in Fig. 1 is one of the many electrostatic demonstrations from the 19th century that continue to amuse and delight students today. It also introduces them to some good physics.

  5. PHOTOCOPY OF 19th CENTURY PHOTO OF THE ORIGINAL BRIDGE, courtesy ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    PHOTOCOPY OF 19th CENTURY PHOTO OF THE ORIGINAL BRIDGE, courtesy of Erie Railway Company - Erie Railway, Buffalo Division, Bridge 361.66, Genesee River, State Route 436, Portageville, Wyoming County, NY

  6. Heat and Kinetic Theory in 19th-Century Physics Textbooks: The Case of Spain.

    ERIC Educational Resources Information Center

    Vaquero, Jose M.; Santos, Andres

    2001-01-01

    Presents an analysis of the contents of 19th century Spanish textbooks. These textbooks are centered on imponderable fluids, the concept of energy, the mechanical theory of heat, and the kinetic theory of gases. (SAH)

  7. Heat and Kinetic Theory in 19th-Century Physics Textbooks: The Case of Spain

    NASA Astrophysics Data System (ADS)

    Vaquero, Joseb M.; Santos, Andrebs

    Spain was a scientifically backward country in the early 19th century. The causes were various political events, the War of Independence, and the reign of Fernando VII. The introduction of contemporary physics into textbooks was therefore a slow process. An analysis of the contents of 19th-century Spanish textbooks is presented here, centred on imponderable fluids, the concept of energy, the mechanical theory of heat, and the kinetic theory of gases.

  8. Compound floating pivot micromechanisms

    DOEpatents

    Garcia, Ernest J.

    2001-04-24

    A new class of tilting micromechanical mechanisms have been developed. These new mechanisms use compound floating pivot structures to attain far greater tilt angles than are practical using other micromechanical techniques. The new mechanisms are also capable of bi-directional tilt about multiple axes.

  9. The biological standard of living and mortality in Central Italy at the beginning of the 19th century.

    PubMed

    Coppola, Michela

    2013-12-01

    The biological standard of living in Central Italy at the beginning of the 19th century is analyzed using newly collected data on the height of recruits in the army of the Papal States. The results reveal a decline in height for the cohorts born under French rule (1796-1815). Although this trend was common to many parts of Europe, the estimated magnitude of the decline suggests a worsening of the biological standard of living of the working classes in the Papal States even relative to that of other countries. Despite the differences in the economic systems within the Papal States, no significant geographical variation in height has been found: even the most dynamic and advanced regions experienced a dramatic height decline. Mortality also increased during the period under consideration.

  10. PREFACE: 19th International Conference on Electron Dynamics in Semiconductors, Optoelectronics and Nanostructures (EDISON'19)

    NASA Astrophysics Data System (ADS)

    González, T.; Martín-Martínez, M. J.; Mateos, J.

    2015-10-01

    The 19th International Conference on Electron Dynamics in Semiconductors, Optoelectronics and Nanostructures (EDISON'19) was held at the Hospedería Fonseca (Universidad de Salamanca, Spain), on 29 June - 2 July, 2015, and was organized by the Electronics Area from the University of Salamanca. The Conference is held biannually and covers the recent progress in the field of electron dynamics in solid-state materials and devices. This was the 19th meeting of the international conference series formerly named Hot Carriers in Semiconductors (HCIS), first held in Modena in 1973. In the edition of 1997 in Berlin the name of the conference changed to International Conference on Nonequilibrium Carrier Dynamics in Semiconductors, keeping the same acronym, HCIS; and finally in the edition of Montpellier in 2009 the name was again changed to the current one, International Conference on Electron Dynamics in Semiconductors, Optoelectronics and Nanostructures (EDISON). The latest editions took place in Santa Barbara, USA, in 2011 and Matsue, Japan, in 2013. Research work on electron dynamics involves quite different disciplines, and requires both fundamental and technological scientific efforts. Attendees to the conference come mostly from academic institutions, belonging to both theoretical and experimental groups working in a variety of fields, such as solid-state physics, electronics, optics, electrical engineering, material science, laser physics, etc. In this framework, events like the EDISON conference become a basic channel for the progress in the field. Here, researchers working in different areas can meet, present their latest advances and exchange their ideas. The program of EDISON'19 included 13 invited papers, 61 oral contributions and 73 posters. These contributions originated from scientists in more than 30 different countries. The Conference gathered 140 participants, coming from 24 different countries, most from Europe, but also with a significant participation

  11. The purple coloration of four late 19th century silk dresses: A spectroscopic investigation

    NASA Astrophysics Data System (ADS)

    Woodhead, Andrea L.; Cosgrove, Bronwyn; Church, Jeffrey S.

    2016-02-01

    Prior to the 19th century the use of purple dyes for textile coloration was expensive and usually limited to royalty. The discovery of several synthetic purple dyes during the 19th century made the production of purple textiles more affordable and thus more readily available. The identification of the source of the purple coloration is of historical interest. Small yarn samples from four late 19th century silk dresses were analyzed using a combination of thin layer chromatography and surface enhanced Raman spectroscopy, Fourier transform infrared spectroscopy and energy dispersive x-ray spectroscopy. This combination of techniques enabled the analysis of the complex extraction products. While three of the dresses were found to be dyed using methyl violet, the fourth dress was found to be constructed from a warp yarn dyed with methyl violet in the presence of a tannic acid mordant, and a weft yarn dyed with mauve and a tin mordant.

  12. Micromechanisms with floating pivot

    DOEpatents

    Garcia, Ernest J.

    2001-03-06

    A new class of tilting micromechanical mechanisms have been developed. These new mechanisms use floating pivot structures to relieve some of the problems encountered in the use of solid flexible pivots.

  13. [Foods and drinks in a 19th century human physiology textbook].

    PubMed

    Chiancone, Francesco M

    2004-01-01

    The Author reports on the chapter of "Nutrition" in the Human Physiology textbook by P. Albertoni and A. Stefani published in the first half of the 19th century. This is one of the first textbooks that treats Physiology as an experimental science in contrast with the thinking of the previous century which was still dominated by Galen and Dioscorides.

  14. Missionaries and Tonic Sol-fa Music Pedagogy in 19th-Century China

    ERIC Educational Resources Information Center

    Southcott, Jane E.; Lee, Angela Hao-Chun

    2008-01-01

    In the 19th century, Christian missionaries in China, as elsewhere, used the Tonic Sol-fa method of music instruction to aid their evangelizing. This system was designed to improve congregational singing in churches, Sunday schools and missions. The London Missionary Society and other evangelical groups employed the method. These missionaries took…

  15. 5. Photocopy, GENERAL VIEW OF FORT TOTTEN, LOOKING NORTHWEST, mid19th ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    5. Photocopy, GENERAL VIEW OF FORT TOTTEN, LOOKING NORTHWEST, mid-19th century. Original photograph at State Historical Society of North Dakota, file No. B 37 - Fort Totten, 12 miles southwest of Devils Lake City off Route 57, Devils Lake, Ramsey County, ND

  16. The Romantic Rhetoric of 19th Century Obituaries: "She Gave a Few Faint Gasps and Died."

    ERIC Educational Resources Information Center

    Agnew, Eleanor

    Scholars of writing, language, and culture will find a rich fund of research material in 19th-century obituaries which convey extensive details of the deceased's life through an elegant language reminiscent of an oral culture. In contrast to today's newspaper obituaries, which are business-like, tight-lipped, and entirely devoid of any details or…

  17. An Analysis of Environmental Issues in 19th Century England Using the Writings of Charles Dickens

    ERIC Educational Resources Information Center

    MacKenzie, Ann Haley

    2008-01-01

    Charles Dickens lived during the best and worst of times in 19th century England. His writings were greatly influenced by the ongoing industrial revolution. He described abhorrent environmental conditions, inadequate sanitary practices, child abuse, and other social maladies of the times. By bringing Charles Dickens into the biology classroom,…

  18. Circumcision of the Female Intellect: 19th Century Women Who Opposed Scholarly Education

    ERIC Educational Resources Information Center

    Holmes, Marbeth

    2009-01-01

    In 19th century America, some women decried the opportunity for scholarly education as rebellion against religion and predicted a grim decline in the quality of life, home, and hearth for American families and for American culture and politics. In particular, women who opposed scholarly education argued that God had not created men and women…

  19. Japanese Concepts of Child Development from the Mid-17th to Mid-19th Century.

    ERIC Educational Resources Information Center

    Kojima, Hideo

    1986-01-01

    Summarizes beliefs and values about child rearing from documents written by experts on the mid-17th to mid-19th centuries. The experts argued that children are innately good rather than evil; environmental factors accounted for differences among children rather than innate factors; and children were autonomous rather than passive learners. (HOD)

  20. The Garbers: Using Digital History To Recreate a 19th-Century Family.

    ERIC Educational Resources Information Center

    Mason, Cheryl L.; Carter, Alice

    1999-01-01

    Describes a lesson in which students read a letter from the Web site "Valley of the Shadow: Two Communities during the American Civil War," an interactive archive of digitized primary sources. Students search the site's 1860 population census to learn about Thomas Garber and his family. Students also learn about life in the 19th century.…

  1. Seriously Popular: Rethinking 19th-Century American Literature through the Teaching of Popular Fiction

    ERIC Educational Resources Information Center

    Gatti, Lauren

    2011-01-01

    Curious about the connections between the author's students' reading tastes and those of 19th-century readers, the author read Nina Baym's excellent text "Novels, Readers, and Reviewers: Responses to Fiction in Antebellum America" to gain a sense of how readers in the 1800s might have thought about the texts that they read. Nineteenth-century…

  2. MOSQUITO VECTOR CONTROL AND BIOLOGY IN LATIN AMERICA - A 19TH SYMPOSIUM

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The 19th Annual Latin American symposium presented by the American Mosquito Control Association (AMCA) was held as part of the 75th Annual Meeting in New Orleans, LA, in April 2009. The principal objective, as for the previous 18 symposia, was to promote participation in the AMCA by vector control s...

  3. Pacific Telecommunications Council Annual Conference Proceedings (19th, Honolulu, Hawaii, January 19-22, 1997).

    ERIC Educational Resources Information Center

    Wedemeyer, Dan J., Ed.; Nickelson, Richard, Ed.

    This PTC'97 volume contains papers presented at the 19th annual conference of the Pacific Telecommunications Council, "Pacific Connections: Policy and Technology in the Information Economy" (1997). Three super-session groupings--industry, policy, and technology--provide attendees with a conceptual foundation from which subsequent…

  4. 1. COPY OF A LATE 19TH CENTURY BUSINESS CARD FOR ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. COPY OF A LATE 19TH CENTURY BUSINESS CARD FOR A. ALEXANDER & SON FLOURING MILLS. CARD OWNED BY THOMAS R. WILSON. Photographer: Berni Rich, Score Photographers, September 1986. - Alexander's Grist Mill, Lock 37 on Ohio & Erie Canal, South of Cleveland, Valley View, Cuyahoga County, OH

  5. Negative Numbers in the 18th and 19th Centuries: Phenomenology and Representations

    ERIC Educational Resources Information Center

    Maz-Machado, Alexander; Rico-Romero, Luis

    2009-01-01

    This article presents a categorization of the phenomena and representations used to introduce negative numbers in mathematics books published in Spain during the 18th and 19th centuries. Through a content analysis of fourteen texts which were selected for the study, we distinguished four phenomena typologies: physical, accounting, temporal and…

  6. Dancetime! 500 Years of Social Dance. Volume I: 15th-19th Centuries. [Videotape].

    ERIC Educational Resources Information Center

    Teten, Carol

    This VHS videotape recording is the first in a two-volume series that presents 500 years of social dance, music, and fashion. It focuses on the 15th-19th centuries, including Renaissance nobility, Baroque extravagance, Regency refinement, and Victorian romanticism. Each era reflects the changing relationships between men and women through the…

  7. [Rape and transgression. Forensic medicine and sexual morality in Spain in the 19th century].

    PubMed

    Carpena, Amalio Lorente

    2010-01-01

    The purpose of this paper is to analyse the importance of the contribution of the Spanish forensic medical discourse in the 19th century, and its application in cases of sexual harassment, to legitimize the sexual moral value of the time. For that reason we will analyse the main forensic medicine treaties edited in Spain during this century.

  8. "Le Droit de L'Enfant:" Ideologies of the Child in 19th Century French Literature and Child Welfare Reform.

    ERIC Educational Resources Information Center

    Kirschner, Suzanne

    This paper examines ideological themes present in movements for child labor reform and in literature in 19th century France. Separate sections cover early industrialization and child labor reform, the image of the romantic child in French literature, and ideology and reforms. By the mid-19th century, England, America, and France all had their…

  9. The tympanostomy tube: an ingenious invention of the mid 19th century.

    PubMed

    Mudry, Albert

    2013-02-01

    The introduction of the tympanostomy tube in the treatment of otitis media with effusion in the mid 20th century completely revolutionized its therapy. Nevertheless, it was not a new idea. The aim of this research is to elucidate the origin of prosthetic middle ear ventilation in the mid 19th century. A review of primary sources revealed at least seven different models of tympanostomy tube which were manufactured between 1845 and 1875. These included: Frank's gold tube, Lincke's rubber tube, Bonnafont's silver cannula, Politzer's hard rubber drain, Miot's metallic eyelet, Voltolini's gold ring, and Bonnafont's eyelet. Study of these early innovations shows that all of the technical and surgical principles of the tympanostomy tube were known in the mid 19th century. Widespread introduction into otological practice did not occur until the mid 20th century invention of the operating microscope.

  10. Racial differences in body mass indices of men imprisoned in 19th Century Texas.

    PubMed

    Carson, Scott Alan

    2009-03-01

    A limited amount of research has been done on the body mass index values of 19th century Americans. This paper uses Texas prison records to demonstrate that, in contrast to today's distributions, most BMI values were in the normal range. Only 21.5% and 1.2% of the population was overweight or obese, while today comparable figures are 36% and 23%. There was also little change in BMI values between 1876 and 1919. Farmers were consistently heavier than non-farmers, while Southwestern men had lower BMI values than their counterparts from other regions of the US. BMI values indicate that 19th century African-Americans, and whites populations were well fed in spite of large expenditures on energy.

  11. [Criminology and superstition at the turn of the 19th century].

    PubMed

    Bachhiesl, Christian

    2012-01-01

    Criminology, which institutionalised at university level at the turn of the 19th century, was intensively engaged in the exploration of superstition. Criminologists investigated the various phenomena of superstition and the criminal behaviour resulting from it. They discovered bizarre (real or imagined) worlds of thought and mentalities, which they subjected to a rationalistic regime of interpretation in order to arrive at a better understanding of offences and crimes related to superstition. However, they sometimes also considered the use of occultist practices such as telepathy and clairvoyance to solve criminal cases. As a motive for committing homicide superstition gradually became less relevant in the course of the 19th century. Around 1900, superstition was accepted as a plausible explanation in this context only if a psychopathic form of superstition was involved. In the 20th century, superstition was no longer regarded as an explanans but an explanandum.

  12. Physics education in the Greek community schools of Istanbul (19th century). The books

    NASA Astrophysics Data System (ADS)

    Lazos, Panayotis; Vlahakis, George N.

    2016-03-01

    During the 19th century a number of elementary and high schools were established for the need of the Greek community of Istanbul. Among the courses included in the curricula were those concerning the scientific study of Nature like Botany, Chemistry and Physics. In the present study we attempt to give a thorough description of the educational material used in these schools for the study of natural sciences with an emphasis in Physics. Especially we shall discuss the books used as course books as well as their probable sources. Furthermore we shall try to make a comparison with the relevant situation in the Greek state and the Ottoman Empire, where modern physics had been already introduced through textbooks based on Ganot's treatise on Physics. The results of our research will give for the first time a picture of the way Greek students in the 19th century Istanbul received their basic knowledge about Physics.

  13. Late 19th- and early 20th-century discussions of animal magnetism.

    PubMed

    Alvarado, Carlos S

    2009-10-01

    The mesmerists explained the phenomena of what was later called hypnosis as the effects of a force called animal magnetism. Both psychologists' and physicians' writings generally create the impression that the magnetic movement disappeared after the mid-19th century. While the concept of animal magnetism declined significantly by the end of the 19th century, it did not disappear completely. Some examples include the work of Hector Durville, Henri Durville, Emile Magnin, and Edmund Shaftesbury. Detailed accounts of the work of Edmund Gurney and Albert de Rochas are presented. Similar to its earlier counterpart, the late mesmeric movement was associated with what today is known as parapsychological phenomena. This association, and the belief that the demise of magnetic theory represents scientific progress, has led many to emphasize a history that is incomplete.

  14. Proceedings of the 19th annual meeting of the Adhesion Society

    SciTech Connect

    Ward, T.C.

    1996-12-31

    This is the proceedings of the 19th Annual Meeting of the Adhesion Society, held February 18-21, 1996. Papers are presented on various aspects of adhesion, ranging from studies at the molecular level, to studies of the intermixing of polymer chains across interface joints, to the study of polymer/metal joints. Separate abstracts of articles from this proceedings have been indexed into the database.

  15. JPRS Report, Soviet Union, Political Affairs, Preparations for the 19th Party Conference, Part 4.

    DTIC Science & Technology

    2007-11-02

    important element that would be political, that is, would fully meet the require- ments of party allegiance and party policy, which is a science and...historical sciences , former secretary of the party’s Saratov Obkom, under rubric "Towards the 19th Ail-Union Party Conference": "Teaching That Which...only two do not exist, but even one does not exist? According to the data of medical science , the risk factor for getting a heart attack has

  16. [Hygiene, hygienism and public health policy in late 19th century France].

    PubMed

    Cavé, Isabelle

    2015-01-01

    In France the desire to expand public health developed mainly because of the hygienist movement which prevailed in the 19th century. This paper aims to show how medical doctors committed themselves deeply at the Chambre des députés and Sénat with the objective of creating the legislation to control sanitary standards which was written between 1870 and 1914.

  17. [From ancient pot collections to the modern medicines. Menier's pot collection-19th century].

    PubMed

    Demouy, Isabelle

    2012-02-01

    At the beginning of the 19th century in 1816, Jean Antoine Brutus Menier founded the "Maison Centrale de Droguerie Menier". It supplied most of the pharmacies in France with drugs of animal, plant and mineral origin for the pharmaceutical preparations recommended at that time. The company provided training for many chemists and pharmacists, and as such, had a collection of pots containing over seven hundred drugs that is currently held at the head office of the Council of the College of Pharmacists in Paris. After having described the pot collection, set it against the 19th century background which experienced a real revolution within this profession, and after retracing its history, a study was then carried out in order to compare the former uses with the modern uses for each of the drugs. Thanks to this detailed, comparative analysis it is now possible to evaluate the relevance of the therapeutic range of drugs in the first half of the 19th century, before the significant rise in chemistry. The Germinal Law changed the pharmacist's profession, and with the birth of chemistry, the art of the pharmacy was revolutionised. However, the drugs, and particularly those of plant origin, have managed to keep a dominant position in today's pharmaceutical domain and in the French or European Pharmacopoeia.

  18. The psychologist as a poet: Kierkegaard and psychology in 19th-century Copenhagen.

    PubMed

    Pind, Jörgen L

    2016-11-01

    Psychology had an early start at the University of Copenhagen in the first half of the 19th century, where it was taught as the major part of a compulsory course required of all first-year students. Particularly important in the establishment of psychology at the university was Frederik Christian Sibbern, who was professor of philosophy from 1813 to 1870. Sibbern wrote numerous works on psychology throughout his career. In his first book on psychology, Sibbern expressed the view that the ideal psychologist should also be a poet. Søren Kierkegaard, Sibbern's student, was precisely such a poet-psychologist. Kierkegaard discussed psychology in many of his works, reflecting the gathering momentum of psychology in 19th-century Copenhagen, Denmark. The article brings out some aspects of Kierkegaard's poetic and literary-imaginative approach to psychology. In his opinion, psychology was primarily a playful subject and limited in the questions about human nature it could answer, especially when it came up against the "eternal" in man's nature. Kierkegaard had a positive view of psychology, which contrasts sharply with his negative views on the rise of statistics and the natural sciences. In the latter half of the 19th century, psychology turned positivistic at the University of Copenhagen. This left little room for Kierkegaard's kind of poetic psychology. (PsycINFO Database Record

  19. Delamination micromechanics analysis

    NASA Technical Reports Server (NTRS)

    Adams, D. F.; Mahishi, J. M.

    1985-01-01

    A three-dimensional finite element analysis was developed which includes elastoplastic, orthotropic material response, and fracture initiation and propagation. Energy absorption due to physical failure processes characteristic of the heterogeneous and anisotropic nature of composite materials is modeled. A local energy release rate in the presence of plasticity was defined and used as a criterion to predict the onset and growth of cracks in both micromechanics and macromechanics analyses. This crack growth simulation technique is based upon a virtual crack extension method. A three-dimensional finite element micromechanics model is used to study the effects of broken fibers, cracked matrix and fiber-matrix debond on the fracture toughness of the unidirectional composite. The energy release rates at the onset of unstable crack growth in the micromechanics analyses are used as critical energy release rates in the macromechanics analysis. This integrated micromechanical and macromechanical fracture criterion is shown to be very effective in predicting the onset and growth of cracks in general multilayered composite laminates by applying the criterion to a single-edge notched graphite/epoxy laminate subjected to implane tension normal to the notch.

  20. Probabilistic composite micromechanics

    NASA Technical Reports Server (NTRS)

    Stock, T. A.; Bellini, P. X.; Murthy, P. L. N.; Chamis, C. C.

    1988-01-01

    Probabilistic composite micromechanics methods are developed that simulate expected uncertainties in unidirectional fiber composite properties. These methods are in the form of computational procedures using Monte Carlo simulation. A graphite/epoxy unidirectional composite (ply) is studied to demonstrate fiber composite material properties at the micro level. Regression results are presented to show the relative correlation between predicted and response variables in the study.

  1. [Epidemic Cholera and American Reform Movements in the 19th Century].

    PubMed

    Kim, Seohyung

    2015-12-01

    The 19th century was the age of great reform in American history. After constructing of the canal and railroads, the industrialization began and American society changed so rapidly. In this period, there were so many social crisis and American people tried to solve these problems within the several reform movements. These reform movements were the driving forces to control cholera during the 19th century. Cholera was the endemic disease in Bengal, India, but after the 19th century it had spread globally by the development of trade networks. The 1832 cholera in the United States was the first epidemic cholera in American history. The mortality of cholera was so high, but it was very hard to find out the cause of this fatal infectious disease. So, different social discourses happened to control epidemic cholera in the 19th century, these can be understood within the similar context of American reform movements during this period. Board of Health in New York States made a new public health act to control cholera in 1832, it was ineffective. Some people insisted that the cause of this infectious disease was the corruption of the United States. They emphasized unjust and immoral system in American society. Moral reform expanded to Nativism, because lots of Irish immigrants were the victims of cholera. So, epidemic cholera was the opportunity to spread the desire for moral reform. To control cholera in 1849, the sanitary reform in Britain had affected. The fact that it was so important to improve and maintain the water quality for the control and prevention of disease spread, the sanitary reform happened. There were two different sphere of the sanitary reform. The former was the private reform to improve sewer or privy, the latter was the public reform to build sewage facilities. The 1849 cholera had an important meaning, because the social discourse, which had emphasized the sanitation of people or home expanded to the public sphere. When cholera broke out in 1866 again

  2. Glacier changes on South Georgia since the late-19th century documented in historical photographs

    NASA Astrophysics Data System (ADS)

    Gordon, John; Haynes, Valerie

    2014-05-01

    South Georgia is one of the few landmasses in the Southern Ocean. It provides a crucial geographical datapoint for glacier responses to climate change over different timescales. As part of an ongoing glacier inventory of the island, we are compiling a database of historical glacier photographs. Since the late 19th century, the island has been visited by numerous scientific and survey expeditions, as well as being the land-base for a major whaling industry. Historical photographs of the island are available from the late-19th century, beginning with the 1882-83 German International Polar Year Expedition. Many more exist from the 20th century, notably from the South Georgia Surveys in the 1950s. An assessment of the value of the photographs indicates that spatial coverage is variable, many lack reference features to pinpoint glacier positions and, in the case of smaller glaciers, the presence of snowcover makes it difficult to define the ice edge. Nevertheless, the photographs provide useful corroboration of more advanced glacier positions during the late-19th century and recession of smaller mountain and valley glaciers during the mid-20th century, while larger tidewater and sea-calving glaciers generally remained in relatively advanced positions until the 1980s. Since then, nearly all the glaciers have retreated; some of these retreats have been dramatic and a number of small mountain glaciers have fragmented or disappeared. The response of the glaciers can be related to synoptic-scale warming, particularly since the 1950s, moderated by individual glacier geometry and topography.

  3. Parents and children: ideas of heredity in the 19th century.

    PubMed

    Waller, John C

    2003-06-01

    The concept of heredity played a powerful role in structuring 19th-century debates over sickness, morality, class, race, education, social change and evolution. But there was very little agreement as to which qualities were heritable and how new hereditary variants were acquired. In consequence, notions of heredity existed in a wide variety of forms, expressing anything from extreme determinism and a belief in the incorrigibility of individuals, social and racial groups, to unleavened optimism, and a faith in ultimate human perfectibility. This article explores these rich hereditarian discourses to convey an impression of a century that was at least as preoccupied with the concept of biological inheritance as we are today.

  4. A 19th Century "Ideal" Oil Paint Medium: A Complex Hybrid Organic-Inorganic Gel.

    PubMed

    de Viguerie, Laurence; Jaber, Maguy; Pasco, Hélène; Lalevée, Jacques; Morlet-Savary, Fabrice; Ducouret, Guylaine; Rigaud, Baptiste; Pouget, Thierry; Sanchez, Clément; Walter, Philippe

    2017-02-01

    British 19th century painters such as J. M. W. Turner, commonly modified the properties of their paint by using gels called "gumtions". These gels allowed them to easily tune the paint handling and drying properties. The fascinating properties of these "gumtions" were obtained by adding lead acetate to a ternary system based on mastic resin, linseed oil and turpentine. Herein, we report and investigate in depth the rheological properties of these gels as well as their structure at a molecular and supra-molecular scale.

  5. Proceedings of the 19th Space Photovoltaic Research and Technology Conference

    NASA Technical Reports Server (NTRS)

    Castro, Stephanie (Compiler); Morton, Thomas (Compiler)

    2007-01-01

    The 19th Space Photovoltaic Research and Technology Conference (SPRAT XIX) was held September 20 to 22, 2005, at the Ohio Aerospace Institute (OAI) in Brook Park, Ohio. The SPRAT Conference, hosted by the Photovoltaic and Space Environments Branch of the NASA Glenn Research Center, brought together representatives of the space photovoltaic community from around the world to share the latest advances in space solar cell technology. This year's conference continued to build on many of the trends shown in SPRAT XVIII-the continued advances of thin-film and multijunction solar cell technologies and the new issues required to qualify those types of cells for space applications.

  6. [Private clinics in Nuremberg in the 19th and 20th century].

    PubMed

    Vasold, Manfred

    2008-01-01

    As a consequence of the industrialization German cities grew very rapidly during the 19th century. Nuremberg reached the number of 100 000 in 1881. Although that city had a large Municipality Hospital (since 1845), a number of specialized private hospitals was founded. Julius Cnopf, a doctor from Nuremberg, founded a children's hospital, one of the first children's hospitals in Germany. The Nuremberg Muncipality Hospital had more than 1000 beds before 1914 and many more than 2000 after 1945, for this reason the number of private owned hospitals remained rather small. Nonetheless were these small and highly specialized hospitals quite important for the city population of Nuremberg.

  7. An archival exploration of 19th-century American adult female offender parricides.

    PubMed

    Shon, Phillip Chong Ho; Williams, Christopher R

    2013-01-01

    Social and behavioral scientists have increasingly attended to the contexts and motivational dynamics underlying parricidal events. These efforts notwithstanding, most research has focused on adolescent or adult male offender populations. One largely neglected area of study is that of adult female offender parricide. The present study utilizes archival records to examine the contexts and sources of conflict that gave rise to adult female offender parricides in the late 19th century. Three general themes emerged, representing the primary contexts behind adult female offender parricide: (1) abuse and neglect; (2) instrumental, financially-motivated killings; and (3) expressive killings, often during the course of arguments. Each of these contexts is explored.

  8. 19th JANNAF Safety and Environmental Protection Subcommittee Meeting. Volume 1

    NASA Technical Reports Server (NTRS)

    Cocchiaro, J. E. (Editor); Becker, D. L. (Editor)

    2002-01-01

    This volume, the first of two volumes, is a compilation of 22 unclassified/unlimited technical papers presented at the 19th Joint Army-Navy-NASA-Air Force (JANNAF) Safety & Environmental Protection Subcommittee Meeting. The meeting was held 18-21 March 2002 at the Sheraton Colorado Springs Hotel, Colorado Springs, Colorado. Topics covered include green energetic materials and life cycle pollution prevention; space launch range safety; propellant/munitions demilitarization, recycling, and reuse: and environmental and occupational health aspects of propellants and energetic materials.

  9. [Emergence, migrations and reduction to routine in the political sciences (17th-19th centuries)].

    PubMed

    Beaud, Jean-Pierre

    2009-01-01

    This article explores the paths through which percentage imposed itself in the political sciences. At first used in the financial domain, percentage is incorporated in 1662 by Graunt in the field of studies of mortality; in the beginning of the 19th century it migrates towards studies in population growth, then it migrates to other territories to become a tool of general application. Each migration enters the framework of a new problematic: "the birth of mortality" in one case; "the birth of population" in the other. The recourse to percentages thus appears as one of the elements in the foundation of statistical objectivism.

  10. [The politics of the self: psychological science and bourgeois subjectivity in 19th century Spain.].

    PubMed

    Novella, Enric J

    2010-01-01

    This paper offers an analysis of the process of institutionalization of psychological knowledge in Spain following the educative reforms implemented during the second third of the 19th century, which prescribed its inclusion in the curricular program of the new secondary education. After a detailed examination of the theoretical orientation, the ideological assumptions and the socio-political connections of the contents transmitted to the students throughout the century, its militant spiritualism is interpreted as a highly significant attempt on the part of the liberal elites to articulate a pedagogy of subjectivity intended to counteract the trends toward reduction, naturalization and fragmentation of psychic life inherent to the development of modern science.

  11. [The explicative models of infectious diseases in Canada in the 19th Century].

    PubMed

    Goulet, Denis; Thouez, Jean-Pierre

    2004-01-01

    Until the last third of the 19th Century in Canada, physicians looked for the causes of infectious diseases and adopted explicative models associated to airist theories, climatic variations and the physical environment. Rarely did they mention the social environment. Yet, the interpretation of disease plays a fundamental role in the elaboration of preventive measures. Consequently, Canadian physicians adopted a naturalist approach based on local sanitation rather than a social approach of the disease. This reinforced the concept of "predisposing causes". By examining local conditions and, to a lesser extent, the living conditions of Quebec's population, the pre-bacteriologist theories prepared the way for the intervention of modern hygienists.

  12. Yale University Is Preserving Its Great Late-19th-Century Architecture by Remodeling the Old Campus

    ERIC Educational Resources Information Center

    Architectural Record, 1977

    1977-01-01

    Renovation of four late-19th-century Yale dormitories makes the most of their unique architectural character. Available from: Publications Office, 1221 Avenue of the Americas, New York, New York 10020; $5.00 single copy. (Author/MLF)

  13. The 'Ajuda Paralyses': history of a neuropsychiatric debate in mid-19th-century Portugal.

    PubMed

    Fontoura, Paulo

    2010-10-01

    The second half of the 19th century witnessed an increasing interest in neurology and psychiatry by Portuguese physicians, in parallel with the overall development of these disciplines in other countries. This process is reflected in the numerous case report publications as well as in debates taking place at the Lisbon Society of Medical Sciences, the major scientific forum of that time. The 'Ajuda Paralyses' were a mysterious succession of epidemics that occurred during 1860-64 in the Ajuda asylum for cholera and yellow fever orphans, which were extensively discussed during 1865-66 by Bernardino Antonio Gomes, Antonio Maria Barbosa, Abel Jordão and Eduardo Motta. Studying this debate helps understand the initial stages of development and the great interest that 'nervous diseases' had for Portuguese clinicians in the mid-19th century and possibly provides one of the first modern descriptions of nutrition-related polyradiculoneuropathy and the ocular findings associated with avitaminosis A. This debate took place at a decisive time for the scientific development of neurology and psychiatry, concurrent with the widespread application of the clinical-anatomical method and neuropathology to the study of diseases of the nervous system, which would set the foundations for our own modern pathophysiological framework. Therefore, the 'Ajuda paralyses' debate also provides a good basis for a discussion on the evolution of the concepts of hysteria and psychosomatic disease and the description of peripheral neuropathy from among a wealth of other entities that did not withstand the test of science.

  14. [Public health services and healthcare workforce in Bakar of the 18th and 19th century].

    PubMed

    Čulina, Tatjana

    2014-01-01

    This review article draws on scarce and poorly studied archival information and several published articles to describe the development and organisation of public health services in the town of Bakar over the 18th and 19th century. For a short while at the turn of the 19th century, Bakar established a hospital run by two physicians and one surgeon to treat patients affected by the so called Škrljevo disease, an endemic type of syphilis. As the century went on, the number of healthcare providers increased by two more physicians, four surgeons, and three to six licensed midwives. There was also a town pharmacy, that worked all that time. As a busy port, the town also provided well-organised maritime sanitary services. As its economy changed over the two centuries to come to a halt after an initial boom, which resulted in a severe drop in population from 7600 to 2000 people, public services deteriorated, including public health. Maritime services suffered the hardest blow, while the workforce gradually came down to one or two physicians and surgeons and several midwives.

  15. Accounts from 19th-century Canadian Arctic explorers' logs reflect present climate conditions

    NASA Astrophysics Data System (ADS)

    Overland, James E.; Wood, Kevin

    The widely perceived failure of 19th-century expeditions to find and transit the Northwest Passage in the Canadian Arctic is often attributed to extraordinary cold climatic conditions associated with the “Little Ice Age” evident in proxy records. However, examination of 44 explorers' logs for the western Arctic from 1818 to 1910 reveals that climate indicators such as navigability, the distribution and thickness of annual sea ice, monthly surface air temperature, and the onset of melt and freeze were within the present range of variability.The quest for the Northwest Passage through the Canadian archipelago during the 19th century is frequently seen as a vain and tragic failure. Polar exploration during the Victorian era seems to us today to have been a costly exercise in heroic futility, which in many respects it was. This perspective has been reinforced since the 1970s, when paleoclimate reconstructions based on Arctic ice core stratigraphy appeared to confirm the existence of exceptionally cold conditions consistent with the period glaciologists had termed the “Little Ice Age” (Figure 1a), with temperatures more than one standard deviation colder relative to an early 20th-century mean [Koerner, 1977; Koerner and Fisher, 1990; Overpeck et al., 1998]. In recent years, the view of the Little Ice Age as a synchronous worldwide and prolonged cold epoch that ended with modern warming has been questioned [Bradley and Jones, 1993; Jones and Briffa, 2001 ;Ogilvie, 2001].

  16. Extending the African instrumental record to the early 19th century

    SciTech Connect

    Nicholson, S.E.

    1997-11-01

    This paper describes progress toward the production of a data set that extends the African climate record back to the beginning of the 19th century. Qualitative documentary evidence, lake-level fluctuations and other proxy indicators are combined with historical rainfall records to produce regional time series. The data set has relatively high temporal and spatial resolution. The conceptualization is based on a climatic regionalization produced using modern data and an anomaly method in previous historical reconstructions. The data set provides information for some 100 regions with a 1 to 5 year resolution for most of the nineteenth century. Three to five quantitative classes of rainfall are utilized in the data set. Here, the available information to produce this record is summarized. The methodology utilized to combine proxy data and observations to produce a quantitative rainfall data set is described. This historical data set is compared with actual rainfall records for select regions where both are available. This comparison indicates the reliability of the proxy African data set. An analysis of the historical record indicates that the main characteristics of rainfall variability evident in the modern African record are also apparent in the 19th century record. 5 figs.

  17. Human Genetic Variation and Yellow Fever Mortality during 19th Century U.S. Epidemics

    PubMed Central

    2014-01-01

    ABSTRACT We calculated the incidence, mortality, and case fatality rates for Caucasians and non-Caucasians during 19th century yellow fever (YF) epidemics in the United States and determined statistical significance for differences in the rates in different populations. We evaluated nongenetic host factors, including socioeconomic, environmental, cultural, demographic, and acquired immunity status that could have influenced these differences. While differences in incidence rates were not significant between Caucasians and non-Caucasians, differences in mortality and case fatality rates were statistically significant for all epidemics tested (P < 0.01). Caucasians diagnosed with YF were 6.8 times more likely to succumb than non-Caucasians with the disease. No other major causes of death during the 19th century demonstrated a similar mortality skew toward Caucasians. Nongenetic host factors were examined and could not explain these large differences. We propose that the remarkably lower case mortality rates for individuals of non-Caucasian ancestry is the result of human genetic variation in loci encoding innate immune mediators. PMID:24895309

  18. Tuberculosis epidemiology and selection in an autochthonous Siberian population from the 16th-19th century.

    PubMed

    Dabernat, Henri; Thèves, Catherine; Bouakaze, Caroline; Nikolaeva, Dariya; Keyser, Christine; Mokrousov, Igor; Géraut, Annie; Duchesne, Sylvie; Gérard, Patrice; Alexeev, Anatoly N; Crubézy, Eric; Ludes, Bertrand

    2014-01-01

    Tuberculosis is one of most ancient diseases affecting human populations. Although numerous studies have tried to detect pathogenic DNA in ancient skeletons, the successful identification of ancient tuberculosis strains remains rare. Here, we describe a study of 140 ancient subjects inhumed in Yakutia (Eastern Siberia) during a tuberculosis outbreak, dating from the 16(th)-19(th) century. For a long time, Yakut populations had remained isolated from European populations, and it was not until the beginning of the 17(th) century that first contacts were made with European settlers. Subsequently, tuberculosis spread throughout Yakutia, and the evolution of tuberculosis frequencies can be tracked until the 19(th) century. This study took a multidisciplinary approach, examining historical and paleo-epidemiological data to understand the impact of tuberculosis on ancient Yakut population. In addition, molecular identification of the ancient tuberculosis strain was realized to elucidate the natural history and host-pathogen co-evolution of human tuberculosis that was present in this population. This was achieved by the molecular detection of the IS6110 sequence and SNP genotyping by the SNaPshot technique. Results demonstrated that the strain belongs to cluster PGG2-SCG-5, evocating a European origin. Our study suggests that the Yakut population may have been shaped by selection pressures, exerted by several illnesses, including tuberculosis, over several centuries. This confirms the validity and necessity of using a multidisciplinary approach to understand the natural history of Mycobacterium tuberculosis infection and disease.

  19. [From spermatic animalcules to sperm cells: the reconceptualization of generation in the 19th century].

    PubMed

    Vienne, Florence

    2009-09-01

    At the end of the 18th and still at the beginning of the 19th century most naturalists considered spermatic animalcules to be parasites of the seminal fluid that played no role in procreation. This view was progressively questioned by 19th century physiologists. They gradually redefined the spermatic animals as (cellular) products of the male organism, as agents of fertilization and bearers of the male heredity material. This article discusses this change from two different perspectives: on a microhistorical level, it analyzes the experimental research of the naturalist Lazzaro Spallanzani (1729-1799) and of the physiologist Albert Kölliker (1817-1905) in order to show how spermatozoa were turned into a new epistemic object of biology--the sperm cell. Further, it asks how the role of the reconceptualization of spermatic animalcules affected the long-term transformations that gave rise of our modern understanding of heredity, generation and the sexed body. By combining these two perspectives, the article aims to connect historiographies that are often kept separate: the macrohistorical narratives about gender and the body in the modern age and the microhistorical studies of biomedical practices and objects.

  20. [Medecine, Law, and Knowledge Production about the "Civilized" War in the Long 19th Century].

    PubMed

    Goltermann, Svenja

    2015-01-01

    The aim to 'civilize' warfare accompanied Medicine and International Law ever since the mid-19th century. However, the entanglement of Medicine and Law, crucial for such an endeavour, has not been taken into consideration so far; likewise, the huge importance of medical knowledge for the perception of wars and their ramifications did not garner much attention in historical research. Hence, by focusing on the 'long' 19th century, this paper shows, firstly, that the production of surgical knowledge during warfare aimed at measuring the effects of combat on human bodies in order to develop prognostic medical knowledge for future wars, as well as maintaining the combat strength of soldiers. Moreover, this knowledge production during warfare strived for the enhancement of medical competence in the diagnosis and treatment of wounds in general. Secondly, I show that this medical knowledge was not only relevant for warfare, but also crucial for the design of International Law: it served to nourish the debates among the so called 'civilized' nations about legitimate and illegitimate weaponry and warfare.

  1. A history of leprosy in Iran during the 19th and 20th centuries.

    PubMed

    Azizi, Mohammad Hossein; Bahadori, Moslem

    2011-11-01

    From ancient time leprosy has been regarded as a terrifying, stigmatized disease; nevertheless, its cause remained unidentified up to the late 19th century. For centuries numerous leprosy victims worldwide suffered from its morbidity and were socially isolated. The afflicted individuals were segregated because they were considered 'unclean' and had to live in leper colonies, generally under very poor conditions. Physicians believed that leprosy was an incurable, highly contagious, and hereditary disease. In 1873 the Norwegian physician, Gerhard Armauer Hansen (1841-1912), ended the myth of leprosy and discovered its causative agent, known as Mycobacterium leprae. Hansen's discovery was a great triumph in the fight against leprosy. In the 1930's, the first effective antileprosy drug, dapsone, was introduced and in the early 1980's multi-drug therapy was popularized because of high efficacy in resistant cases. Here, we have presented a brief look at the history of leprosy in the world with special focus on the historical account of leprosy in Iran, particularly during the 19th and 20th centuries.

  2. Geometric frustration on a 1/9th site depleted triangular lattice

    NASA Astrophysics Data System (ADS)

    Hopkinson, John; Beck, Jarrett

    2013-03-01

    In the searches both for new spin liquid and spin ice (artificial and macroscopic) candidates, geometrically frustrated two-dimensional spin systems have played a prominent role. Here we present a study of the classical antiferromagnetic Ising (AFI) model on the sorrel net, a 1/9th site depleted and 1/7th bond depleted triangular lattice. The AFI model on this corner-shared triangle net is found to have a large residual entropy per spin S/N = 0 . 48185 +/- 0 . 00008 , indicating the sorrel net is highly geometrically frustrated. Anticipating that it may be difficult to achieve perfect bond depletion, we investigate the physics resulting from turning back on the depleted bonds (J2). We present the phase diagram, analytic expressions for the long range partially ordered ground state spin structure for antiferromagnetic J2 and the short range ordered ground state spin structure for ferromagnetic J2, the magnetic susceptibility and the static structure factor. We briefly comment on the possibility that artificial spin ice on the sorrel lattice could by made, and on a recent report [T. D. Keene et al., Dalton Trans. 40 2983 (2011)] of the creation of a 1/9th depleted cobalt hydroxide oxalate. This work was supported by NSERC (JMH) and NSERC USRA (JJB)

  3. [Coping with leprosy in the Dutch West Indies in the 19th century; opposing but meaningful views from Suriname].

    PubMed

    Menke, Henk; Snelders, Stephen; Pieters, Toine

    2009-01-01

    Leprosy was highly prevalent among African slaves in the Dutch West Indian colony of Suriname. Largely based on observations in Suriname, Dutch physicians described the aetiology of leprosy in terms of'a substrate' to which all sorts of mixtures of infection, heredity and hygiene contributed ('seed and soil'). This explanatory model with multiple options for prevention and treatment left room for different developmental trajectories to control the spread of the disease in the various tropical colonies of the Dutch empire. In Suriname there was a growing worry in the 19th century regarding the spread of leprosy, threatening the health of slaves, settlers and colonial administrators. And this could be harmful to an already weakening plantation economy. This concern prompted the local administration to develop a rigorous policy of strict isolation of leprosy sufferers. This, in turn, intersected with a changing insight in Europe - including the Netherlands - that leprosy was non-contagious. However,'in splendid isolation' in the economically and politically marginal colony Suriname, Dutch physicians like Charles Landre and his son, Charles Louis Drognat Landré, could afford to ignore the European non-contagious approach and continue to support the strict isolation policies. Moreover, they developed a dissident radical explanation of leprosy as a disease caused only by contagion. In the absence of a receptive Dutch audience Drognat Landré published his contagion theory in French and so succeeded in inspiring the Norwegian Hansen, who subsequently discovered the culpable micro-organism. At the same time colonial administrators and physicians in the economically and politically important Dutch colonies in the East Indies adhered to the prevailing European concept and changed policies: the system of isolation was abolished. Given the rather different trajectories of leprosy health policies in the Dutch East and West Indies we point out the importance of a comparative

  4. Micromechanical Oscillating Mass Balance

    NASA Technical Reports Server (NTRS)

    Altemir, David A. (Inventor)

    1997-01-01

    A micromechanical oscillating mass balance and method adapted for measuring minute quantities of material deposited at a selected location, such as during a vapor deposition process. The invention comprises a vibratory composite beam which includes a dielectric layer sandwiched between two conductive layers. The beam is positioned in a magnetic field. An alternating current passes through one conductive layers, the beam oscillates, inducing an output current in the second conductive layer, which is analyzed to determine the resonant frequency of the beam. As material is deposited on the beam, the mass of the beam increases and the resonant frequency of the beam shifts, and the mass added is determined.

  5. Micromechanics of hearing

    NASA Astrophysics Data System (ADS)

    Hudspeth, A. J.

    2015-12-01

    The following summarizes the key points addressed during a tutorial session on the Micromechanics of Hearing that took place at the 12th International Workshop on the Mechanics of Hearing held at Cape Sounio, Greece, in June 2014. The tutorial was intended to present an overview of basic ideas and to address topics of current interest relevant to the Workshop. The session was recorded, and the audio file and accompanying visual content of the presentation can be found in the Mechanics of Hearing Digital Library (www.mechanicsofhearing.org).

  6. Paths to and from poverty in late 19th century novels

    PubMed Central

    Howden‐Chapman, Philippa; Kawachi, Ichiro

    2006-01-01

    Late 19th century novels provide graphic descriptions of working and living conditions and their impact on population health, in particular the detrimental effects of hunger, poor housing, environmental conditions, hazardous work and poor pay, smoking and alcohol and crime, but also the transformative possibilities of social and political action. The popularity of these novels helped raise the collective conscience of citizens and illuminated the direction for 20th century welfare reforms. Yet many of these problems remain and the pathways to and from poverty are still recognisable today. Although novels are now less central in conveying social information, re‐reading these novels enables us to understand how social and economic circumstances were understood at the time and what led to social and political change. PMID:16415257

  7. Following rules in the intermontane west: 19th-century mormon settlement.

    PubMed

    Norton, W

    2001-01-01

    The academic discipline of human geography is concerned with human activities, especially as these relate to physical landscapes and contribute to the modification of those landscapes. Although little attention has been paid to objectivist philosophies to inform human geography, behavior analysis might offer a useful explanatory model. As an example, a behavior analysis of selected aspects of 19th-century Mormon movement and settlement in the intermontane West is conducted. Mormons are a society of believers who practice cooperative effort and support for other members, and the Mormon church is governed by priesthood authority with members being called to perform tasks. This analysis employs the concepts of metacontingency, rule-governed behavior, and delayed reinforcement to analyze how Mormons settled the intermontane West.

  8. Electrical treatment of spinal cord injuries in the 18th and 19th centuries.

    PubMed

    Silver, John R; Weiner, M-F

    2013-05-01

    Two centuries ago, electricity was being used for the treatment of paraplegia and trials were taking place in France. This study aims to identify cases of traumatic paraplegia treated with electricity in the 19th century in order to assess the therapeutic benefit. Only four such cases were identified, none with a complete transection of the spinal cord since these patients would have died from pressure sores and urinary tract infections. The personalities involved, William Gull, William Erb, Guillaume Duchenne and Cyril Henry Golding Bird are portrayed and contemporaneous views on electrotherapy analysed. While the four patients apparently benefited from the treatment, the lack of follow-up and the incomplete data prevented a definitive conclusion on the therapeutic value of electrical treatment in traumatic paraplegia.

  9. Apothecary activity in Dubrovnik Dominican Monastery from 17th to the beginning 19th century.

    PubMed

    Krasic, Stjepan

    2011-01-01

    The origin of the Dominican monastery pharmacy is not clear, but sources suggest that it had operated from the eve of the great earthquake in Dubrovnik in 1667 to the beginning of the 19th century. Its last pharmacist, praised for his competence, passed away in 1803, leaving no one behind The prior travelled all the way to Naples to find a competent pharmacist in his stead, but never returned. Story has it that on the way back, the abbot and the pharmacist lost their lives in a shipwreck. The French army occupied the town in 1806, and the monastery was turned into a military camp. Following the retreat of the French army in 1814, the monastery was returned to the Dominicans, but the pharmacy was never restored.

  10. Height of female Americans in the 19th century and the antebellum puzzle.

    PubMed

    Carson, Scott Alan

    2011-03-01

    Using 19th century state prison records, this study contrasts the biological standard of living of comparable US African-American and white females during a period of relatively rapid economic development. White females were consistently taller than black females by about 1.5 cm (0.6 in.). Whites from Great Lakes and Plains states and black Southwestern females were the tallest. US females were tall compared to their European counterparts. The height of females began to decline in the antebellum period, possibly before that of males. The recovery of physical stature was also earlier among females than among males. This implies that the biological standard of lower-class men and women did not move in parallel during the onset of modern economic growth. It also implies that the antebellum puzzle was most likely rooted in the endogenous forces of socio-economic change rather than the exogenous changes in the disease environment.

  11. Placenta Accreta and Total Placenta Previa in the 19th Week of Pregnancy.

    PubMed

    Findeklee, S; Costa, S D

    2015-08-01

    Placentation disorders are the result of impaired embedding of the placenta in the endometrium. The prevalence of these disorders is estimated to be around 0.3 %. A history of previous prior uterine surgery (especially cesarean section and curettage) is the most common risk factor. Impaired placentation is differentiated into deep placental attachment; marginal, partial and total placenta previa; and placenta accreta, increta and percreta. Treatment depends on the severity of presentation and ranges from expectant management to emergency hysterectomy. In most cases, preterm termination of pregnancy is necessary. We report here on the case of a 39-year-old woman with placenta accreta and total placenta previa who underwent hysterectomy in the 19th week of pregnancy.

  12. [Healthcare in times of epidemics in Rio de Janeiro in the 19th century].

    PubMed

    Pimenta, Tânia Salgado

    2011-01-01

    This article aims to examine the provision of healthcare for the population of Rio de Janeiro in the mid-19th century and describe its reorganization during the crisis caused by outbreaks of yellow fever and cholera. In this context, it is essential to consider the significant changes taking place in healthcare during this period, also affecting the spaces in which hospital care was offered. Therefore, we focussed our investigation on Santa Casa da Misericórdia Hospital, the most important hospital in the capital of the Brazilian Empire. The sources used are the correspondence between the government and the hospital, the hospital annual reports, archives of the Central Board of Public Hygiene, and wide-circulation medical journals.

  13. Following rules in the intermontane west: 19th-century mormon settlement

    PubMed Central

    Norton, William

    2001-01-01

    The academic discipline of human geography is concerned with human activities, especially as these relate to physical landscapes and contribute to the modification of those landscapes. Although little attention has been paid to objectivist philosophies to inform human geography, behavior analysis might offer a useful explanatory model. As an example, a behavior analysis of selected aspects of 19th-century Mormon movement and settlement in the intermontane West is conducted. Mormons are a society of believers who practice cooperative effort and support for other members, and the Mormon church is governed by priesthood authority with members being called to perform tasks. This analysis employs the concepts of metacontingency, rule-governed behavior, and delayed reinforcement to analyze how Mormons settled the intermontane West. PMID:22478355

  14. The Rise of Commercial Telescope Making in 19th Century America

    NASA Astrophysics Data System (ADS)

    Launie, Kenneth J.

    2009-01-01

    Very few telescopes were made in America in the 18th century; astronomers needed to rely on distant European makers. While there is evidence of a few American craftsman-made telescopes that were shown at early to mid-19th century Mechanics' Fairs, Massachusetts native Amasa Holcomb appears to have been the first to offer them for sale commercially. Most of Holcomb's instruments were Herschelian reflectors with speculum metal mirrors. Henry Fitz started his optical career by making mirrors used for the first Daguerreotype portrait cameras, and by the mid 1840's he was offering refractors of ever-increasing size. Not long after Fitz started, Alvan Clark began selling telescopes, and the premature death of Fitz in 1863 may have aided Alvan Clark and Sons' rise to prominence. The later decades of the 1800s saw a dramatic increase in the number of college observatories, and with that came more manufacturers to supply the demand.

  15. [Brain physiology and the development of psychiatry in the 19th century].

    PubMed

    Alvarez Pelaez, R

    1993-01-01

    Great developments in study of the central and peripheral nervous system took place throughout the 19th century, especially in Britain. These studies, together with other factors, gave rise to the development of a somaticism of mental illness. The followers of this school of thought, most notably Henry Maudsley, supported the idea of materialism, based on the theory of evolution. They were opposed by those who believed in the duality of body and mind whith its different variants. These two visions constituted the centre of the theoretical debate of psychiatry at that time. The author pays special attention to the first stance and reaches the conclusion that this process of knowledge made mental illness to be considered as an organic disease and contribuited to the entry of the lunatic wholly into the sphere or medical action.

  16. Prospects for using sonar for underwater archeology on the Yenisei: surveying a 19th century shipwreck

    NASA Astrophysics Data System (ADS)

    Goncharov, A. E.; Mednikov, D. M.; Karelin, N. M.; Nasyrov, I. R.

    2016-11-01

    Current progress in underwater archeology is based on a rich arsenal of high-tech appliances, among which sonar technology plays a key role; it enables scientists not only to detect submerged archeological objects, but to examine them in high definition without having to conduct diving operations or use expensive underwater unmanned vehicles. While the majority of sensational scientific discoveries using sonar have been made in saltwater environments, freshwater ones, rivers in particular, have seen limited activity. The river Yenisei in central Siberia contains an unrecorded number of shipwrecks that await being discovered and studied. In this article we focus on the peculiarities of using sonar for detecting archeological sites on the Yenisei. This article is based on the results of the 2016 expedition, which has determined the location of Thames, a 19th century British steam schooner which was wrecked on the Yenisei.

  17. Lockyer's "Astronomy" among Serbs in the second half of the 19th century.

    NASA Astrophysics Data System (ADS)

    Trajkovska, V.; Ninković, S.

    1997-08-01

    The dynamical development of astronomy in the second half of 19th century has also found its adequate response among Serbs. As a good example may serve, in the opinion of the present authors, the translation of "Astronomy" by N. Lockyer into Serbian (the book was printed in 1880 in Novi Sad). The translator was Djordje Natošević who translated not the English original, but the German translation. The authors find Natošević an interesting personality. A physician by education he devoted the best part of his life to pedagogy and to enhancing the educational level in Serbian primary and secondary schools in Austria-Hungary of those days. He spent some time also in Serbia. It was then that he translated from German the textbook "Astronomy" by Lockyer, popular in those days.

  18. Reconstructions of global near-surface temperature change since the mid 19th century

    NASA Astrophysics Data System (ADS)

    Morice, Colin; Rayner, Nick; Kennedy, John

    2016-04-01

    Incomplete and non-uniform global observational coverage is a prominent source of uncertainty in instrumental records of global near-surface temperature change. In this study statistical methods are applied to the HadCRUT4 near-surface temperature data set to obtain improved estimates of global near-surface temperature change since the mid 19th century. Methods applied include those that interpolate according to local correlation structure (kriging) and reduced space methods that learn large-scale temperature patterns. The performance of each statistical reconstruction method has been benchmarked in application to a subset of CMIP5 simulations. Model fields are sub-sampled and simulated observational errors added to emulate observational data, permitting assessment of temperature field reconstruction algorithms in controlled tests in which globally complete temperature fields are known. In application to HadCRUT4 data the statistical reconstructions show relatively increased warming in the global average over the 21st century owing to reconstruction of temperatures in high northern latitudes, supporting the findings of Cowtan & Way (2014) and Karl et al. (2015). There is broad agreement between estimates of global and hemispheric changes throughout much of the 20th and 21st century. Agreement is reduced in data sparse periods and regions, notably in the 19th century and in the southern hemisphere. This finding is supported by the results of the climate model based benchmarks and highlights the importance of continued data rescue activities, such as those of the International Surface Temperature Initiative and ACRE. The results of this study will form an addition to the HadCRUT4 global near-surface temperature data set.

  19. Ochres and earths: matrix and chromophores characterization of 19th and 20th century artist materials.

    PubMed

    Montagner, Cristina; Sanches, Diogo; Pedroso, Joana; Melo, Maria João; Vilarigues, Márcia

    2013-02-15

    The present paper describes the main results obtained from the characterization of a wide range of natural and synthetic ochre samples used in Portugal from the 19th to the 20th century, including powder and oil painting samples. The powder ochre samples came from several commercial distributors and from the collection of Joaquim Rodrigo (1912-1997), a leading Portuguese artist, particularly active during the sixties and seventies. The micro-samples of oil painting tubes came from the Museu Nacional de Arte Contemporânea-Museu do Chiado (National Museum of Contemporary Art-Chiado Museum) in Lisbon and were used by Columbano Bordalo Pinheiro (1857-1929), one of the most prominent naturalist Portuguese painters. These tubes were produced by the main 19th century colourmen: Winsor & Newton, Morin et Janet, Maison Merlin, and Lefranc. The samples have been studied using μ-Fourier Transform Infrared Spectroscopy (μ-FTIR), Raman microscopy, μ-Energy Dispersive X-ray fluorescence (μ-EDXRF), and X-ray diffraction (XRD). The analyzed ochres were found to be a mixture of several components: iron oxides and hydroxides in matrixes with kaolinite, gypsum and chalk. The results obtained allowed to identify and characterize the ochres according to their matrix and chromophores. The main chromophores where identified by Raman microscopy as being hematite, goethite and magnetite. The infrared analysis of the ochre samples allowed to divide them into groups, according to the composition of the matrix. It was possible to separate ochres containing kaolinite matrix and/or sulfate matrix from ochres where only iron oxides and/or hydroxides were detected. μ-EDXRF and Raman were the best techniques to identify umber, since the presence of elements such as manganese is characteristic of these pigments. μ-EDXRF also revealed the presence of significant amounts of arsenic in all Sienna tube paints.

  20. Ochres and earths: Matrix and chromophores characterization of 19th and 20th century artist materials

    NASA Astrophysics Data System (ADS)

    Montagner, Cristina; Sanches, Diogo; Pedroso, Joana; Melo, Maria João; Vilarigues, Márcia

    2013-02-01

    The present paper describes the main results obtained from the characterization of a wide range of natural and synthetic ochre samples used in Portugal from the 19th to the 20th century, including powder and oil painting samples. The powder ochre samples came from several commercial distributors and from the collection of Joaquim Rodrigo (1912-1997), a leading Portuguese artist, particularly active during the sixties and seventies. The micro-samples of oil painting tubes came from the Museu Nacional de Arte Contemporânea-Museu do Chiado (National Museum of Contemporary Art-Chiado Museum) in Lisbon and were used by Columbano Bordalo Pinheiro (1857-1929), one of the most prominent naturalist Portuguese painters. These tubes were produced by the main 19th century colourmen: Winsor & Newton, Morin et Janet, Maison Merlin, and Lefranc. The samples have been studied using μ-Fourier Transform Infrared Spectroscopy (μ-FTIR), Raman microscopy, μ-Energy Dispersive X-ray fluorescence (μ-EDXRF), and X-ray diffraction (XRD). The analyzed ochres were found to be a mixture of several components: iron oxides and hydroxides in matrixes with kaolinite, gypsum and chalk. The results obtained allowed to identify and characterize the ochres according to their matrix and chromophores. The main chromophores where identified by Raman microscopy as being hematite, goethite and magnetite. The infrared analysis of the ochre samples allowed to divide them into groups, according to the composition of the matrix. It was possible to separate ochres containing kaolinite matrix and/or sulfate matrix from ochres where only iron oxides and/or hydroxides were detected. μ-EDXRF and Raman were the best techniques to identify umber, since the presence of elements such as manganese is characteristic of these pigments. μ-EDXRF also revealed the presence of significant amounts of arsenic in all Sienna tube paints.

  1. Micromechanical Study of Metals

    NASA Technical Reports Server (NTRS)

    Velikov, P. A.; Stchapov, N. P.; Lorenz, W. F.

    1945-01-01

    The Institut Scientifique Experimental des Transports at Moscow established toward the end of 1925 had since its inception included in its program the study of the mechanism of plastic deformation and the problems associated with it with reference to the materials of the means of transport. Before the program thus determined upon could be carried out, it was necessary to adopt a method of research, or, more exactly, a system of such methods. Because of the modest equipment of the laboratory of the recently established institute, the choice of any particular method was determined not only by the advantages it offered but also by the resources available. As a result of a series of studies and investigations, a method was determined upon which in this paper will be denoted as the micromechanical method. The underlying basis of this method is already known. As will be seen from the description that follows, the micromechanical method is merely a combination of the micrographic study of plastic deformations with mechanical tests on small specimens. It is a well-known fact that a number of investigators have largely employed and still are employing these two procedures and have thereby obtained good results. The authors of the present paper have found it useful to combine the two methods, by making the two studies simultaneously on the sane specimen.

  2. A Micromechanical RF Channelizer

    NASA Astrophysics Data System (ADS)

    Akgul, Mehmet

    The power consumption of a radio generally goes as the number and strength of the RF signals it must process. In particular, a radio receiver would consume much less power if the signal presented to its electronics contained only the desired signal in a tiny percent bandwidth frequency channel, rather than the typical mix of signals containing unwanted energy outside the desired channel. Unfortunately, a lack of filters capable of selecting single channel bandwidths at RF forces the front-ends of contemporary receivers to accept unwanted signals, and thus, to operate with sub-optimal efficiency. This dissertation focuses on the degree to which capacitive-gap transduced micromechanical resonators can achieve the aforementioned RF channel-selecting filters. It aims to first show theoretically that with appropriate scaling capacitive-gap transducers are strong enough to meet the needed coupling requirements; and second, to fully detail an architecture and design procedure needed to realize said filters. Finally, this dissertation provides an actual experimentally demonstrated RF channel-select filter designed using the developed procedures and confirming theoretical predictions. Specifically, this dissertation introduces four methods that make possible the design and fabrication of RF channel-select filters. The first of these introduces a small-signal equivalent circuit for parallel-plate capacitive-gap transduced micromechanical resonators that employs negative capacitance to model the dependence of resonance frequency on electrical stiffness in a way that facilitates the analysis of micromechanical circuits loaded with arbitrary electrical impedances. The new circuit model not only correctly predicts the dependence of electrical stiffness on the impedances loading the input and output electrodes of parallel-plate capacitive-gap transduced micromechanical device, but does so in a visually intuitive way that identifies current drive as most appropriate for

  3. Micromechanics of fracturing in nanoceramics

    PubMed Central

    Ovid'ko, I. A.

    2015-01-01

    An overview of key experimental data and theoretical representations on fracture processes in nanoceramics is presented. The focuses are placed on crack growth in nanoceramics and their toughening micromechanics. Conventional toughening micromechanisms are discussed which effectively operate in both microcrystalline-matrix ceramics containing nanoinclusions and nanocrystalline-matrix ceramics. Particular attention is devoted to description of special (new) toughening micromechanisms related to nanoscale deformation occurring near crack tips in nanocrystalline-matrix ceramics. In addition, a new strategy for pronounced improvement of fracture toughness of ceramic materials through fabrication of ceramic–graphene nanocomposites is considered. Toughening micromechanisms are discussed which operate in such nanocomposites containing graphene platelets and/or few-layer sheets. PMID:25713442

  4. Micromechanics of fracturing in nanoceramics.

    PubMed

    Ovid'ko, I A

    2015-03-28

    An overview of key experimental data and theoretical representations on fracture processes in nanoceramics is presented. The focuses are placed on crack growth in nanoceramics and their toughening micromechanics. Conventional toughening micromechanisms are discussed which effectively operate in both microcrystalline-matrix ceramics containing nanoinclusions and nanocrystalline-matrix ceramics. Particular attention is devoted to description of special (new) toughening micromechanisms related to nanoscale deformation occurring near crack tips in nanocrystalline-matrix ceramics. In addition, a new strategy for pronounced improvement of fracture toughness of ceramic materials through fabrication of ceramic-graphene nanocomposites is considered. Toughening micromechanisms are discussed which operate in such nanocomposites containing graphene platelets and/or few-layer sheets.

  5. Probabilistic Fiber Composite Micromechanics

    NASA Technical Reports Server (NTRS)

    Stock, Thomas A.

    1996-01-01

    Probabilistic composite micromechanics methods are developed that simulate expected uncertainties in unidirectional fiber composite properties. These methods are in the form of computational procedures using Monte Carlo simulation. The variables in which uncertainties are accounted for include constituent and void volume ratios, constituent elastic properties and strengths, and fiber misalignment. A graphite/epoxy unidirectional composite (ply) is studied to demonstrate fiber composite material property variations induced by random changes expected at the material micro level. Regression results are presented to show the relative correlation between predictor and response variables in the study. These computational procedures make possible a formal description of anticipated random processes at the intra-ply level, and the related effects of these on composite properties.

  6. EDITORIAL: Selected papers from the 19th International Colloquium on Magnetic Films and Surfaces

    NASA Astrophysics Data System (ADS)

    Miyazaki, T.; Inoue, J.

    2007-03-01

    The 19th International Colloquium on Magnetic Films and Surfaces (ICMFS 2006) was held on 14-18 August 2006 at the Sendai International Center in Sendai, Japan. The purpose of the Colloquium was to bring together scientists working on magnetic thin films and surfaces and to provide an opportunity for presentation and discussion of recent experimental and theoretical advances in the field. 285 scientists from 17 countries (Japan: 167, overseas: 118) participated in the Colloquium, as well as 6 family members. There were 56 oral and 178 poster presentations. The oral presentations consisted of 3 plenary talks, 23 invited talks and 30 contributed talks. The number of presentations by scientific category are as follows: Spin dependent transport: 43 Magnetic storage/memory: 9 Magnetization reversal and fast dynamics: 15 Spin injection and spin transfer torque: 26 Magnetic thin films and multilayers: 71 High spin polarization materials: 17 Hard and soft magnetic materials: 3 Magneto-optics: 5 Characterization techniques for thin films and surfaces: 7 Exchange coupling: 13 Micro- and nanopatterned magnetic structures: 18 Micromagnetic modelling: 2 One of the characteristics of the present Colloquium is an increase in the number of presentations in the field of spin-electronics, as seen above. This Cluster Issue of Journal of Physics D: Applied Physics includes several important papers in this rapidly developing field. We believe that, in the future, the field of magnetic materials will maintain its popularity and, on top of that, other fields such as spintronics materials, materials related to life sciences and medicine and also materials related to the environment will be investigated further. The ICMFS Conference started in London in 1964, and is now one of the world-wide conferences on magnetism. The Colloquium has been held in Japan four times now: the previous ones being the 5th ICMFS in the Mount Fuji area, the 10th at Yokohama and the 17th at Kyoto, which was

  7. How to compare the faces of the Earth? Walachia in mid-19th century and nowadays

    NASA Astrophysics Data System (ADS)

    Bartos-Elekes, Zsombor; Magyari-Sáska, Zsolt; Timár, Gábor; Imecs, Zoltán

    2014-05-01

    In 1864 a detailed map was made about Walachia, its title is Charta României Meridionale (Map of Southern Romania), it has 112 map sheets, it is often called after his draughtsman: Szathmári's map. The map has an outstanding position in the history of Romanian cartography, because it indicates a turning-point. Before the map, foreigners (Austrians and Russians) had made topographic maps about this vassal principality of the Ottoman Empire. The Austrian topographic survey (1855-1859) - which served as a basis for this map - was the last one and the most detailed of these surveys. The map was made between the personal-union (1859) and independence (1878) of the Danubian Principalities. This map was the first (to a certain extent) own map of the forming country. In consequence of this survey and map, the Romanian mapping institute was founded, which one - based on this survey and map - began the topographic mapping of the country. In the Romanian scientific literature imperfect and contradictory information has been published about this map. Only a dozen copies of the map were kept in few map collections; the researchers could have reached them with difficulties. During our research we processed the circumstances of the survey and mapmaking discovering its documentation in the archives of Vienna, as well as using the Romanian, Hungarian and German scientific literature. We found the copies in map collections from Vienna to Bucharest. We digitized all the map sheets from different collections. We calculated the parameters of the used geodetic datum and map projection. We published on the web, such we made the map reachable for everybody. The map can be viewed in different zoom levels; can be downloaded; settlements can be found using the place name index; areas can be exported in modern projection, so the conditions of that time could be compared with today's reality. Our poster presents on the one hand the survey and the map realized in mid-19th century and our

  8. Criminal insanity in 19th-century Ireland, Europe and the United States: cases, contexts and controversies.

    PubMed

    Kelly, Brendan D

    2009-01-01

    The insanity defence has a lengthy, complex history. This article provides a concise, comparative background to the evolution of criminal insanity legislation and institutions for the mentally ill in the nineteenth century, with particular reference to Ireland and the United States. Three key themes are identified and explored: (a) the emergence of the insanity defence in the nineteenth century (e.g. the McNaughtan Rules); (b) conditions in nineteenth-century asylums and institutions for the 'criminally insane' (with particular reference to overcrowding, physical illness and asylum deaths); and (c) nineteenth-century considerations of criminal responsibility in women with mental illness (with particular reference to medical and judicial views of the relevance of menstruation, pregnancy and child-birth). These themes are explored through review of historical literature (with particular reference to the work of Dr. Isaac Ray, founding father of forensic psychiatry in the United States) and examination of previously unpublished archival material from the Central Criminal Lunatic Asylum, Dublin.

  9. [Epidemic diseases in the Polish Kingdom in the thirties of the 19th century].

    PubMed

    Rutkowski, Marek

    2004-01-01

    We can observe that after downfall of the November Insurrection the authorities of the Polish Kingdom were effectively engaged in the fight against numerous epidemic diseases plaguing the local society. Among "contagions" of the time there were varicella, "gastric-nervous fever", "gastric-rhinitis fever" and typhus (especially in 1836). As usual, cholera was the most dangerous one. All medical and epidemiological services in the Polish Kingdom were making effective remedial measures in order to neutralize results of the epidemics. The implemented methods were effective enough to limit considerably the incidence and number of deceased during the epidemic, which started in October 1836 and lasted till the next year. An obligation of effective cooperation between the Polish authorities and the Russian army was introduced then. The sanitary action against cholera in 1836-1837 should be very highly assessed from the logistic point of view. The wide action of protective vaccination against varicella and numerous sanitary rules completed the favorable image of the Polish Kingdom sanitary services. All the factors mentioned above lead to a conclusion that in the thirtieth of the 19th century both civil and military authorities of the Polish Kingdom did practically utmost in order to limit negative results of cyclical recurrences of epidemic diseases. It should be also stressed that the protective actions undertaken in that time were both direct and long lasting enterprises.

  10. The impact of childhood sickness on adult socioeconomic outcomes: Evidence from late 19th century America

    PubMed Central

    Warren, John Robert; Knies, Laurie; Haas, Steven; Hernandez, Elaine M.

    2013-01-01

    We use family fixed-effects models to estimate the impact of childhood health on adult literacy, labor force outcomes, and marital status among pairs of white brothers observed as children in the 1880 U.S. Census and then as adults in the 1900–1930 Censuses. Given our focus on the 19th century, we observed a wider array of infectious, chronic, and traumatic health problems than is observed using data that are more recent; our results thus provide some insights into circumstances in modern developing countries where similar health problems are more frequently observed. Compared to their healthy siblings, sick brothers were less likely to be located (and thus more likely to be dead) 20–50 years after their 1880 enumeration. Sick brothers were also less likely to be literate, to have ever been married, and to have reported an occupation. However, among those with occupations, sick and healthy brothers tended to do similar kinds of work. We discuss the implications of our results for research on the impact of childhood health on socioeconomic outcomes in developed and developing countries. PMID:22809795

  11. Naming and Necessity: Sherborn’s Context in the 19th Century

    PubMed Central

    McOuat, Gordon

    2016-01-01

    Abstract By the late 19th Century, storms plaguing early Victorian systematics and nomenclature seemed to have abated. Vociferous disputes over radical renaming, the world-shaking clash of all-encompassing procrustean systems, struggles over centres of authority, and the issues of language and meaning had now been settled by the institution of a stable imperial museum and its catalogues, a set of rules for the naming of zoological objects, and a new professional class of zoologists. Yet, for all that tranquillity, the disputes simmered below the surface, re-emerging as bitter struggles over synonyms, trinomials, the subspecies category, the looming issues of the philosophy of scientific language, and the aggressive new American style of field biology – all pressed in upon the received practice of naming and classifying organisms and the threat of anarchy. In the midst rose an index. This paper will explore the context of CD Sherborn’s Index Animalium and those looming problems and issues which a laborious and comprehensive “index of nature” was meant to solve. PMID:26877652

  12. Factors influencing the recession rate of Niagara Falls since the 19th century

    NASA Astrophysics Data System (ADS)

    Hayakawa, Yuichi S.; Matsukura, Yukinori

    2009-09-01

    The rate of recession of Niagara Falls (Horseshoe and American Falls) in northeastern North America has been documented since the 19th century; it shows a decreasing trend from ca. 1 m y - 1 a century ago to ca. 0.1 m y - 1 at present. Reduction of the flow volume in the Niagara River due to diversion into bypassing hydroelectric schemes has often been taken to be the factor responsible, but other factors such as changes in the waterfall shape could play a role and call for a quantitative study. Here, we examine the effect of physical factors on the historically varying recession rates of Niagara Falls, using an empirical equation which has previously been proposed based on a non-dimensional multiparametric model which incorporates flow volume, waterfall shape and bedrock strength. The changes in recession rates of Niagara Falls in the last century are successfully modeled by this empirical equation; these changes are caused by variations in flow volume and lip length. This result supports the validity of the empirical equation for waterfalls in rivers carrying little transported sediment. Our analysis also suggests that the decrease in the recession rate of Horseshoe Falls is related to both artificial reduction in river discharge and natural increase in waterfall lip length, whereas that of American Falls is solely due to the reduction in flow volume.

  13. Collateral damage to marine and terrestrial ecosystems from Yankee whaling in the 19th century.

    PubMed

    Drew, Joshua; López, Elora H; Gill, Lucy; McKeon, Mallory; Miller, Nathan; Steinberg, Madeline; Shen, Christa; McClenachan, Loren

    2016-11-01

    Yankee whalers of the 19th century had major impacts on populations of large whales, but these leviathans were not the only taxa targeted. Here, we describe the "collateral damage," the opportunistic or targeted taking of nongreat whale species by the American whaling industry. Using data from 5,064 records from 79 whaling logs occurring between 1840 and 1901, we show that Yankee whalers captured 5,255 animals across three large ocean basins from 32 different taxonomic categories, including a wide range of marine and terrestrial species. The taxa with the greatest number of individuals captured were walruses (Odobenus rosmarus), ducks (family Anatidae), and cod (Gadus sp.). By biomass, the most captured species were walruses, grampus (a poorly defined group within Odontoceti), and seals (family Otariidae). The whalers captured over 2.4 million kg of nongreat whale meat equaling approximately 34 kg of meat per ship per day at sea. The species and areas targeted shifted over time in response to overexploitation of whale populations, with likely intensive local impacts on terrestrial species associated with multiyear whaling camps. Our results show that the ecosystem impacts of whaling reverberated on both marine and coastal environments.

  14. F/A-18 1/9th scale model tail buffet measurements

    NASA Technical Reports Server (NTRS)

    Martin, C. A.; Glaister, M. K.; Maclaren, L. D.; Meyn, L. A.; Ross, J.

    1991-01-01

    Wind tunnel tests were carried out on a 1/9th scale model of the F/A-18 at high angles of attack to investigate the characteristics of tail buffet due to bursting of the wing leading edge extension (LEX) vortices. The tests were carried out at the Aeronautical Research Laboratory low-speed wind tunnel facility and form part of a collaborative activity with NASA Ames Research Center, organized by The Technical Cooperative Program (TTCP). Information from the program will be used in the planning of similar collaborative tests, to be carried out at NASA Ames, on a full-scale aircraft. The program covered the measurement of unsteady pressures and fin vibration for cases with and without the wing LEX fences fitted. Fourier transform methods were used to analyze the unsteady data, and information on the spatial and temporal content of the vortex burst pressure field was obtained. Flow visualization of the vortex behavior was carried out using smoke and a laser light sheet technique.

  15. [Contribution of 19th-century religious congregations in the development of the nursing profession].

    PubMed

    Bezze, Sabrina; Manzoni, Edoardo; Di Mauro, Stefania

    2013-01-01

    The purpose of this historical research project is to examine the contribution of 19th-century religious congregations in the development of the nursing profession, based on the historical example of the Sisters of Charity of Sts. Bartolomea Capitanio and Vincenza Gerosa (or the Sisters of the Holy Child Mary). To this end, sixty three volumes were analysed, all taken from the historical archive of the Generalate of the Sisters of the Holy Child Mary in Milan, in via S. Sofia n.13, with the exception of just one, taken from the Braidense National Library, also in Milan. This research project has highlighted the sociological contribution provided by the Sisters of the Holy Child Mary to the professional nature of nursing, and to the development of the distinctive features of the nursing profession (Greenwood, 1980). All documentary sources were analysed in line with the Chabod historical research method (2006), and for their critical interpretation, a scheme of analysis was created. Two lines of investigation emerged from the data collected: the role of Sister Emilia Vinante as an expert with regard to the nursing profession, and the professional strategies promoted by FIRO (Federation of Italian Religious Nurses). Based on the conclusions of the research project, it may be stated that religious congregations contributed greatly to the nursing profession, leaving a decisive mark on the cultural and professional development of nurses.

  16. Elizabeth Brown and the Classification of Sunspots in the 19th Century

    NASA Astrophysics Data System (ADS)

    Larsen, Kristine

    2014-06-01

    British amateur astronomers collected solar observation data as members of organizations such as the British Astronomical Association (BAA) and Liverpool Astronomical Society (LAS) in the late 1800s. Amateur astronomer Elizabeth Brown (1830-99) served as Solar Section Director of both groups, and not only aggregated solar observations (including hand-drawn illustrations) from observers from around the globe, but worked closely with solar astronomer Edward Maunder and other professionals in an attempt to garner specific types of observations from BAA members in order to answer a number of astronomical questions of the day. For example, she encouraged the monitoring of the growth and decay of sunspot groups and published a number of her own observations of particular groups, urging observers to note whether faculae were seen before the birth of sunspots in a given region, a topic of controversy at that time. She also developed a system for classifying sunspots and sunspot groups based on their appearance, dividing then into 11 types: normal, compound, pairs, clusters, trains, streams, zigzags, elliptical, vertical, nebulous, and dots. This poster will summarize Brown’s important contributions to solar observing in the late 19th century and situate her classification scheme relative to those of A.L. Cortie (1901), M. Waldmeier (1938; 1947) and the modified Zurich system of McIntosh (1966; 1969; 1989).

  17. The mid 19th and early 20th Century Pull of a Nearby Eclipse Shadow Path

    NASA Astrophysics Data System (ADS)

    Bonifácio, Vitor

    2012-09-01

    The unique observing conditions allowed by total solar eclipses made them a highly desirable target of 19th and early 20th century astronomical expeditions, particularly after 1842. Due to the narrowness of the lunar shadow at the Earth's surface this usually implied traveling to faraway locations with all the subsequent inconveniences, in particular, high costs and complex logistics. A situation that improved as travel became faster, cheaper and more reliable. The possibility to observe an eclipse in one's own country implied no customs, no language barriers, usually shorter travelling distances and the likely support of local and central authorities. The eclipse proximity also provided a strong argument to pressure the government to support the eclipse observation. Sometimes the scientific elite would use such high profile events to rhetorically promote broader goals. In this paper we will analyse the motivation, goals, negotiating strategies and outcomes of the Portuguese eclipse expeditions made between 1860 and 1914. We will focus, in particular, on the observation of the solar eclipses of 22 December 1870 and 17 April 1912. The former allowed the start-up of astrophysical studies in the country while the movie obtained at the latter led Francisco da Costa Lobo to unexpectedly propose a polar flattening of the Moon.

  18. Climate and history in the late 18th and early 19th centuries

    NASA Astrophysics Data System (ADS)

    Feldman, Theodore S.

    As in many areas of human knowledge, the notion of climate acquired a deeper historical content around the turn of the 19th century. Natural philosophers, geographers, and others became increasingly aware of climate's own history and its relation to human, plant and animal, and Earth history. This article examines several aspects of this “historicization” of climate.The lively 18th century discussion of the influence of climate on society is well known. Montesquieu is its most famous representative, but Voltaire, Hume, Kant, and others also participated. Their debate was literary more than scientific, their goal the understanding of man, not climate. Partly for this reason and partly because of the lack of good information on climates, they made no attempt to gather substantial climatic data. In fact, the importance of systematically collecting reliable data was scarcely understood in any area of natural philosophy before the last decades of the century [Cf. Frängsmyr et al., 1990; Feldman, 1990]. Instead, participants in the debate repeated commonplaces dating from Aristotle and Hippocrates and based their conclusions on unreliable reports from travelers. As Glacken wrote of Montesquieu, “his dishes are from old and well-tested recipes” [Glacken, 1967, chapter 12]. This is not to say that the debate over climatic influence was not significant—only that its significance lay more in the history of man than in the atmospheric sciences.

  19. Shark tooth weapons from the 19th Century reflect shifting baselines in Central Pacific predator assemblies.

    PubMed

    Drew, Joshua; Philipp, Christopher; Westneat, Mark W

    2013-01-01

    The reefs surrounding the Gilbert Islands (Republic of Kiribati, Central Pacific), like many throughout the world, have undergone a period of rapid and intensive environmental perturbation over the past 100 years. A byproduct of this perturbation has been a reduction of the number of shark species present in their waters, even though sharks play an important in the economy and culture of the Gilbertese. Here we examine how shark communities changed over time periods that predate the written record in order to understand the magnitude of ecosystem changes in the Central Pacific. Using a novel data source, the shark tooth weapons of the Gilbertese Islanders housed in natural history museums, we show that two species of shark, the Spot-tail (Carcharhinus sorrah) and the Dusky (C. obscurus), were present in the islands during the last half of the 19(th) century but not reported in any historical literature or contemporary ichthyological surveys of the region. Given the importance of these species to the ecology of the Gilbert Island reefs and to the culture of the Gilbertese people, documenting these shifts in baseline fauna represents an important step toward restoring the vivid splendor of both ecological and cultural diversity.

  20. Age-specific measles mortality during the late 19th-early 20th centuries.

    PubMed

    Shanks, G D; Waller, M; Briem, H; Gottfredsson, M

    2015-12-01

    Measles mortality fell prior to the introduction of vaccines or antibiotics. By examining historical mortality reports we sought to determine how much measles mortality was due to epidemiological factors such as isolation from major population centres or increased age at time of infection. Age-specific records were available from Aberdeen; Scotland; New Zealand and the states of Australia at the end of the 19th and beginning of the 20th centuries. Despite the relative isolation of Australia, measles mortality was concentrated in very young children similar to Aberdeen. In the more isolated states of Tasmania, Western Australia and Queensland adults made up 14-15% of measles deaths as opposed to 8-9% in Victoria, South Australia and New South Wales. Mortality in Iceland and Faroe Islands during the 1846 measles epidemic was used as an example of islands isolated from respiratory pathogens. The transition from crisis mortality across all ages to deaths concentrated in young children occurred prior to the earliest age-specific mortality data collected. Factors in addition to adult age of infection and epidemiological isolation such as nutritional status and viral virulence may have contributed to measles mortality outcomes a century ago.

  1. Neurologic approaches to hysteria, psychogenic and functional disorders from the late 19th century onwards.

    PubMed

    Stone, J

    2017-01-01

    The history of functional neurologic disorders in the 20th century from the point of view of the neurologist is U-shaped. A flurry of interest between the 1880s and early 1920s gave way to lack of interest, skepticism, and concern about misdiagnosis. This was mirrored by increasing professional and geographic divisions between neurology and psychiatry after the First World War. In the 1990s the advent of imaging and other technology highlighted the positive nature of a functional diagnosis. Having been closer in the early 20th century but later more separate, these disorders are now once again the subject of academic and clinical interest, although arguably still very much on the fringes of neurology and neuropsychiatry. Revisiting older material provides a rich source of ideas and data for today's clinical researcher, but also offers cautionary tales of theories and treatments that led to stagnation rather than advancement of the field. Patterns of treatment do have a habit of repeating themselves, for example, the current enthusiasm for transcranial magnetic stimulation compared to the excitement about electrotherapy in the 19th century. For these reasons, an understanding of the history of functional disorders in neurology is arguably more important than it is for other areas of neurologic practice.

  2. The dawn of chelonian research: turtles between comparative anatomy and embryology in the 19th century.

    PubMed

    MacCord, Kate; Caniglia, Guido; Moustakas-Verho, Jacqueline E; Burke, Ann C

    2015-05-01

    Many evo-devo studies of the turtle's shell draw hypotheses and support from historical sources. The groundbreaking works of Cuvier, Geoffroy St. Hilaire, Carus, Rathke, Owen, and others are being revived in modern research, and their centuries-old understanding of the turtle's shell reconsidered. In the works of these eminent biologists of the 19th century, comparative anatomy and embryology of turtle morphology set the stage for future studies in developmental biology, histology, and paleontology. Given the impact that these works still make on modern research, it is important to develop a thorough appreciation of previous authors, regarding how they arrived at their conclusions (i.e., what counted as evidence?), whether there was debate amongst these authors about shell development (i.e., what counted as an adequate explanation?), and even why these men, some of the most powerful and influential thinkers and anatomists of their day, were concerned with turtles. By tracing and exposing the context and content of turtle shell studies in history, our aim is to inform modern debates about the evolution and development of the turtle's shell.

  3. Structural and behavioural changes in the short term preventive check in the northwest Balkans in the 18th and 19th centuries.

    PubMed

    Hammel, E A; Galloway, P R

    2000-03-01

    Fertility responded negatively to grain insufficiency (proxied by grain price increases), and mortality responded positively in Croatia-Slavonia-Srem in the 18th and 19th centuries, as in most of Europe. Shifts in the intensity and timing of these responses occurred over time as social and economic structures changed. Shifts in the elasticity of fertility with respect to grain supply inversely mimic and lag changes in the elasticity of mortality. Both appear to be induced by increasing land shortage, the collapse of feudalism, and differences in the patterns of adjustment to post-feudal conditions among former civil and military serfs. Generally, responses are stronger for civil and former civil serfs, who may have been in less favorable economic circumstances than the military. Fertility responses in the year of a price shock come to dominate those in the year following, suggesting a shift from contraception to abortion as economic and social conditions apparently worsened and strategies of control intensified. Analysis of monthly responses supports the conjecture based on the annual responses. The shift to the preventive check and strength of the preventive check in the same year as the price shock is unusual in Europe and beyond. Analysis is based on 25 parishes and employs lagged annual and monthly time series analysis with corrections for autocorrelation, in combination with ethnographic and historical data.

  4. Threads of Change in 19th Century American Literature: A Language Arts Unit for Grades 7-9.

    ERIC Educational Resources Information Center

    Crossett, Becky F.; And Others

    This unit of study for junior-high level high-ability language arts students explores five themes in 19th century American history through literature of the times: romanticism, transcendentalism, abolitionism, industrialism, and feminism. Each of the five "isms" has its own "literature box" that contains appropriate documents…

  5. ​​​History of Cholera Outbreaks in Iran during the 19th and 20th Centuries

    PubMed Central

    Azizi, MH; Azizi, F

    2010-01-01

    Cholera is an acute infectious disease with high mortality if left untreated. Historically, between the 19th and 20th centuries seven great pandemics of cholera occurred and worldwide, thousands of people died. Based on an old theory, cholera was considered an air-born disease and the emergence of its outbreaks were attributed to bad weather or miasma. However later in the 18th century, British physician John Snow (1813-1858) explained the association of a terrible cholera outbreak in London in 1849 to contamination of the drinking water supply with human excreta. Despite his finding, the causative agent of this dreaded illness was unidentified until later in the 19th century. In 1854, Filippo Pacini (1812-1883) an anatomist from Italy and then in 1883, Robert Koch (1843-1910) the German bacteriologist, discovered ‘vibrio cholerae’ as the etiologic agent. During the major pandemics of cholera in 19th and 20th centuries this illness reached Iran and led to vast depopulation and a crucial impact on the country’s socioeconomic status. Poor public health conditions, lack of a well-organized public health authority for implementing preventive and quarantine measures as well as Iran’s specific geographic location were the main facilitating factors of the emergence of various epidemics, including cholera in Iran. The present paper briefly reviews the cholera outbreaks in Iran during the 19th and 20th centuries. PMID:25197514

  6. How To Dance through Time. Volume I: The Romance of Mid-19th Century Couple Dances. Beginning Level. [Videotape].

    ERIC Educational Resources Information Center

    Teten, Carol

    This 35-minute VHS videotape is the first in a series of "How To Dance Through Time" videos. It provides how-to instructions to help beginning dancers learn the mid-19th century ballroom couple dances. It introduces dancers to the basic steps, which accompany the romantic dance music of the past. Each dance segment is introduced by a…

  7. The use of Congreve-type war Rockets by the Spanish in the 19th century: A chronology

    NASA Technical Reports Server (NTRS)

    Sancho, P. M.

    1977-01-01

    A yearly account of military uses, by the Spanish, of Congreve war rockets is given, from the year 1810 until 1895. Events prior to the 19th century are also recorded which include the use of rockets against the Moors of Valencia and documentation, from literature of that period, relating to rocket applications.

  8. The Case for Consolidation: Our 19th-Century Model of Governance Is a Formula for Mediocrity

    ERIC Educational Resources Information Center

    Amdursky, Saul

    2004-01-01

    We need fewer public libraries with greater dependence. Here at the beginning of the 21st century, public libraries are still saddled with a 19th-century model of government. They are far too beholden to governing authorities, usually municipal or county governments, for their financial sustenance. This is a formula for mediocrity. "Local control"…

  9. Founding of Compulsory Civil Education According to the Education Acts from Second Half of the 19th Century

    ERIC Educational Resources Information Center

    Lukaš, Mirko

    2012-01-01

    Records of education in Croatia occur very soon after the settlement of Croats in this area. It is tied to 9th century and Duke Trpimir. Initial steps of education were not legally bounded nor the school was obligatory. In the second half of the 19th century, more precisely in 1871, with the First Education Act education becomes obligatory. Using…

  10. How Conceptual Frameworks Influence Clinical Practice: Evidence from the Writings of John Thelwall, a 19th-Century Speech Therapist

    ERIC Educational Resources Information Center

    Duchan, Judith F.

    2006-01-01

    Background: The impact of speech therapists' conceptual frameworks on their clinical methods tends to be ignored or taken for granted by today's practitioners. One way to show the importance of such frameworks is to study how they were used previously. John Thelwall, a 19th-century elocutionist, offers a rich source for studying the influence of…

  11. The Struggle To Survive: Work for Racial Ethnic Women in the 18th- and 19th-Century United States.

    ERIC Educational Resources Information Center

    Higginbotham, Elizabeth

    The work situations of Black, Mexican American, and Chinese immigrant women in 18th- and 19th-century United States are explored. Generally, when engaged in agricultural work, all ethnic people were considered units of labor. However, because the slave owner needed to perpetuate his property, Black women were allowed lower rates of production when…

  12. [Eventful life stories. Members of student fraternities persecuted in Silesia in the early 19th century].

    PubMed

    Schmidt, Walter

    2003-01-01

    This study supplemented by three charts and a list of biographies, is, for the first time, encompassing their life-data, their resumés and even their professional careers as well as political commitments shown by more than 200 Silesian students. They, at the University of Breslau, but also at other German universities, had joined the student fraternities in the 20-ies and early 30-ies of the 19th century and, in consequence, were persecuted by state authorities, notably in Prussia and, in the majority of cases, had been sentenced to prison terms of varying degrees. The first demagogic persecution, which happened in the first half of the twenties, culminating in 1822 in the Breslau Arminen Trail and ending up with the staging of the Youth-Association-Trail in 1826, had implicated about 100 Silesians, with a smaller portion of them - apart from teh three Youth-Association Silesians who were sentenced to five years imprisonment in a fortress - getting away with a relatively short "political fortress imprisonment". Later a considerable part of them made a career in the prussian judicial authority, in the institutions of higher learning, as parish priests, physicians and scientists, whereas any political engagement remained a rare exception. Out of the 137 Silesian members of the student fraternities affected by the second wave of persecution, the overwhelming majority of them being Protestants and originating partly from the middle classes, mostly artisans, and from intellectual background, with about a hundred of them being given essentially higher sentences ranging from six years up to capital punishment and, in the event of reprieves, they had to serve their sentences between six months and four-to-six years in a fortress. The majority of them made a medium-level professional career, never exceeding the medium ranks, as judicial officers, lawyers in state or communal services, parish priests, teachers or physicians. However, from this group of persecuted persons, a

  13. Micromechanics of shear banding

    SciTech Connect

    Gilman, J.J.

    1992-08-01

    Shear-banding is one of many instabilities observed during the plastic flow of solids. It is a consequence of the dislocation mechanism which makes plastic flow fundamentally inhomogeneous, and is exacerbated by local adiabatic heating. Dislocation lines tend to be clustered on sets of neighboring glide planes because they are heterogeneously generated; especially through the Koehler multiple-cross-glide mechanism. Factors that influence their mobilities also play a role. Strain-hardening decreases the mobilities within shear bands thereby tending to spread (delocalize) them. Strain-softening has the inverse effect. This paper reviews the micro-mechanisms of these phenomena. It will be shown that heat production is also a consequence of the heterogeneous nature of the microscopic flow, and that dislocation dipoles play an important role. They are often not directly observable, but their presence may be inferred from changes in thermal conductivity. It is argued that after deformation at low temperatures dipoles are distributed a la Pareto so there are many more small than large ones. Instability at upper yield point, the shapes of shear-band fronts, and mechanism of heat generation are also considered. It is shown that strain-rate acceleration plays a more important role than strain-rate itself in adiabatic instability.

  14. Micromechanics of Drosophila Audition

    NASA Astrophysics Data System (ADS)

    Göpfert, M. C.; Robert, D.

    2003-02-01

    An analysis is presented of the auditory micromechanics of the fruit fly Drosophila melanogaster. In this animal, the distal part of the antenna constitutes a resonantly tuned sound receiver, the vibrations of which are transduced by a chordotonal sense organ in the antenna's base. Analyzing the mechanical behavior of the antennal receiver by means of microscanning laser Doppler vibrometry, we show that the auditory system of wild-type flies exhibits a hardening stiffness nonlinearity and spontaneously generates oscillations in the absence of external stimuli. According to the deprivation of these mechanical properties in mechanosensory mutants, the receiver's nonlinearity and oscillation activity are introduced by chordotonal auditory neurons. Requiring the mechanoreceptor-specific extracellular linker protein No-mechanoreceptor-potential-A (NompA), NompC mechanosensory transduction channels, Beethoven (Btv), and Touch-insensitive-larva-B (TilB), nonlinearity and oscillation activity of the fly's antennal receiver depend on prominent components of the auditory transduction machinery and seem to originate from motility of auditory receptor cilia.

  15. 19th century London dust-yards: a case study in closed-loop resource efficiency.

    PubMed

    Velis, Costas A; Wilson, David C; Cheeseman, Christopher R

    2009-04-01

    The material recovery methods used by dust-yards in early 19th century London, England and the conditions that led to their development, success and decline are reported. The overall system developed in response to the market value of constituents of municipal waste, and particularly the high coal ash content of household 'dust'. The emergence of lucrative markets for 'soil' and 'breeze' products encouraged dust-contractors to recover effectively 100% of the residual wastes remaining after readily saleable items and materials had been removed by the thriving informal sector. Contracting dust collection to the private sector allowed parishes to keep the streets relatively clean, without the need to develop institutional capacity, and for a period this also generated useful income. The dust-yard system is, therefore, an early example of organised, municipal-wide solid waste management, and also of public-private sector participation. The dust-yard system had been working successfully for more than 50 years before the Public Health Acts of 1848 and 1875, and was thus important in facilitating a relatively smooth transition to an institutionalised, municipally-run solid waste management system in England. The dust-yards can be seen as early precursors of modern materials recycling facilities (MRFs) and mechanical-biological treatment (MBT) plants; however, it must be emphasised that dust-yards operated without any of the environmental and occupational health considerations that are indispensable today. In addition, there are analogies between dust-yards and informal sector recycling systems currently operating in many developing countries.

  16. The lost origin of chemical ecology in the late 19th century.

    PubMed

    Hartmann, Thomas

    2008-03-25

    The origin of plant chemical ecology generally dates to the late 1950s, when evolutionary entomologists recognized the essential role of plant secondary metabolites in plant-insect interactions and suggested that plant chemical diversity evolved under the selection pressure of herbivory. However, similar ideas had already flourished for a short period during the second half of the 19th century but were largely forgotten by the turn of the century. This article presents the observations and studies of three protagonists of chemical ecology: Anton Kerner von Marilaun (1831-1898, Innsbruck, Austria, and Vienna, Austria), who mainly studied the impact of geological, climatic, and biotic factors on plant distribution and survival; Léo Errera (1858-1906, Brussels, Belgium), a plant physiologist who analyzed the localization of alkaloids in plant cells and tissues histochemically; and Ernst Stahl (1848-1919, Jena, Germany), likely the first experimental ecologist and who performed feeding studies with snails and slugs that demonstrated the essential role of secondary metabolites in plant protection against herbivores. All three, particularly Stahl, suggested that these "chemical defensive means" evolved in response to the relentless selection pressure of the heterotrophic community that surrounds plants. Although convincingly supported by observations and experiments, these ideas were forgotten until recently. Now, more than 100 years later, molecular analysis of the genes that control secondary metabolite production underscores just how correct Kerner von Marilaun, Errera, and, particularly, Stahl were in their view. Why their ideas were lost is likely a result of the adamant rejection of all things "teleological" by the physiologists who dominated biological research at the time.

  17. Geomagnetic research in the 19th century: a case study of the German contribution

    NASA Astrophysics Data System (ADS)

    Schröder, W.; Wiederkehr, K.-H.

    2001-10-01

    Even before the discovery of electromagnetism by Oersted, and before the work of Ampère, who attributed all magnetism to the flux of electrical currents, A.v. Humboldt and Hansteen had turned to geomagnetism. Through the ``Göttinger Magnetischer Verein'', a worldwide cooperation under the leadership of Gauss came into existence. Even today, Gauss's theory of geomagnetism is one of the pillars of geomagnetic research. Thereafter, J.v. Lamont, in Munich, took over the leadership in Germany. In England, the Magnetic Crusade was started by the initiative of John Herschel and E. Sabine. At the beginning of the 1840s, James Clarke Ross advanced to the vicinity of the southern magnetic pole on the Antarctic Continent, which was then quite unknown. Ten years later, Sabine was able to demonstrate solar-terrestrial relations from the data of the colonial observatories. In the 1980s, Arthur Schuster, following Balfour Stewart's ideas, succeeded in interpreting the daily variations of the electrical process in the high atmosphere. Geomagnetic research work in Germany was given a fresh impetus by the programme of the First Polar Year 1882-1883. Georg Neumayer, director of the ``Deutsche Seewarte'' in Hamburg, was one of the initiators of the Polar Year. He forged a close cooperation with the newly founded ``Kaiserliches Marineobservatorium'' in Wilhelmshaven, and also managed to gain the collaboration of the ``Gauss-Observatorium für Erdmagnetismus'' in Göttingen under E. Schering. In the Polar Year, the first automatic recording magnetometers (Kew-Model) were used in the German observatory at Wilhelmshaven. Here, M. Eschenhagen, who later became director of the geomagnetic section in the new Meteorological Magnetic Observatory in Potsdam, deserves special credit. Early hypotheses of geomagnetism and pioneering palaeomagnetic experiments are briefly reviewed. The essential seismological investigations at the turn of the 19th to the 20th century are also briefly described as

  18. The lost origin of chemical ecology in the late 19th century

    PubMed Central

    Hartmann, Thomas

    2008-01-01

    The origin of plant chemical ecology generally dates to the late 1950s, when evolutionary entomologists recognized the essential role of plant secondary metabolites in plant–insect interactions and suggested that plant chemical diversity evolved under the selection pressure of herbivory. However, similar ideas had already flourished for a short period during the second half of the 19th century but were largely forgotten by the turn of the century. This article presents the observations and studies of three protagonists of chemical ecology: Anton Kerner von Marilaun (1831–1898, Innsbruck, Austria, and Vienna, Austria), who mainly studied the impact of geological, climatic, and biotic factors on plant distribution and survival; Léo Errera (1858–1906, Brussels, Belgium), a plant physiologist who analyzed the localization of alkaloids in plant cells and tissues histochemically; and Ernst Stahl (1848–1919, Jena, Germany), likely the first experimental ecologist and who performed feeding studies with snails and slugs that demonstrated the essential role of secondary metabolites in plant protection against herbivores. All three, particularly Stahl, suggested that these “chemical defensive means” evolved in response to the relentless selection pressure of the heterotrophic community that surrounds plants. Although convincingly supported by observations and experiments, these ideas were forgotten until recently. Now, more than 100 years later, molecular analysis of the genes that control secondary metabolite production underscores just how correct Kerner von Marilaun, Errera, and, particularly, Stahl were in their view. Why their ideas were lost is likely a result of the adamant rejection of all things “teleological” by the physiologists who dominated biological research at the time. PMID:18218780

  19. Forgotten research from 19th century: science should not follow fashion.

    PubMed

    Galler, Stefan

    2015-02-01

    The fine structure of cross-striated muscle and its changes during contraction were known already in considerable detail in the 19th century. This knowledge was the result of studying birefringence properties of muscle fibres under the polarization microscope, a method mainly established by Brücke (Denk Kais Akad Wiss Math Naturwiss Cl 15:69-84, 1858) in Vienna, Austria. The knowledge was seemingly forgotten in the first half of the 20th century before it was rediscovered in 1954. This rediscovery was essential for the formulation of the sliding filament theory which represents the commonly accepted concept of muscle contraction (A.F. Huxley and Niedergerke, Nature 173:971-973, 1954; H.E. Huxley and Hanson, Nature 173:973-976, 1954). The loss of knowledge was the result of prevailing views within the scientific community which could be attributed to "fashion": it was thought that the changes of cross-striations, which were observed under the microscope, were inconsequential for contraction since other types of movements like cell crawling and smooth muscle contraction were not associated with similar changes of the fine structure. The basis for this assumption was the view that all types of movements associated with life must be caused by the same mechanisms. Furthermore, it was assumed that the light microscopy was of little use, because the individual molecules that carry out life functions cannot be seen under the light microscope. This unfortunate episode of science history teaches us that the progress of science can severely be retarded by fashion.

  20. Micromechanics for ceramic matrix composites

    NASA Technical Reports Server (NTRS)

    Murthy, P. L. N.; Chamis, C. C.

    1991-01-01

    The fiber substructuring concepts and the micromechanics equations that are embedded in the Ceramic Matrix Composite Analyzer (CEMCAN) computer code are described as well as the code itself, its current features and capabilities, and some examples to demonstrate the code's versatility. The methodology is equally applicable to metal matrix and polymer matrix composites. The prediction of ply mechanical and thermal properties agree very well with the existing models in the Integrated Composite Analyzer and the Ceramic Matrix Composite Analyzer, lending credence to the fiber substructuring approach. Fiber substructuring can capture greater local detail than conventional unit-cell-based micromechanical theories. It offers promise in simulating complex aspects of micromechanics in ceramic matrix composites.

  1. Then and Now: Fundraising during a Fiscal Crisis--Lessons from the 19th Century

    ERIC Educational Resources Information Center

    Muscatelli, Anton; Mackay, Francesca

    2011-01-01

    A housing and municipal construction bubble popped and generated a lending crisis in which interbank lending rates became impossibly high. The banking crisis, which spread across Europe and the United States, eventually impacted other industries, leading to a stock market crash and an economic contraction lasting several years. This was not in…

  2. Musical expressions of life: a look at the 18th and 19th century from a human becoming perspective.

    PubMed

    Jonas-Simpson, Christine

    2004-10-01

    What follows is an exploration of 18th and 19th century music of the Western world through a nursing science lens, specifically that of the human becoming theory. This article was written while I was enrolled in a music history course, which afforded me the opportunity to explore music as musical expressions of life. Rooted in the human becoming philosophical perspective, which focuses on unitary human experience and the quality of human life, I discuss musical expressions of life with examples from various composers throughout the 18th and 19th century. This article concludes with a reflection on musical expressions and their contribution to the enhancement of the quality of human life, a focus of nursing from a human becoming perspective.

  3. [The construction of a medical discipline and its challenges: Orthopedics in Switzerland during the 19th and 20th centuries].

    PubMed

    Kaba, Mariama

    2015-07-01

    During the 19th century, numerous figures, with different qualifications, claimed to practice orthopedics: doctors, surgeons, inventors of equipment and instruments, and other empiricists. They performed certain types of techniques, massages, surgical operationsand/or fitted prostheses. The polysemous notion of orthopedics had created conflicts of interest that would reach their height at the end of the 19th century. The integration of orthopedics into the training at the university level enhanced its proximity to surgery, a discipline that has dominated the so-called modern medicine. During the 20th century, various medical branches defend the legitimacy of certain orthopedic practices, thereby threating to a degree the title itself of this specialization. By examining the challenges that have shaped the history of orthopedics in Switzerland, this article also seeks to shed light on the strategies that were implemented in adopting a medical and technical discipline within a transforming society.

  4. Stature in 19th and early 20th century Copenhagen. A comparative study based on skeletal remains.

    PubMed

    Jørkov, Marie Louise S

    2015-12-01

    Individual stature depends on multifactorial causes and is often used as a proxy for investigating the biological standard of living. While the majority of European studies on 19th and 20th century populations are based on conscript heights, stature derived from skeletal remains are scarce. For the first time in Denmark this study makes a comparison between skeletal stature and contemporary Danish conscript heights and investigates stature of males and females temporally and between socially distinct individuals and populations in 19th and early 20th century Copenhagen. A total of 357 individuals (181 males, 176 females) excavated at the Assistens cemetery in Copenhagen is analyzed. Two stature regression formulae (Trotter, 1970; Boldsen, 1990) are applied using femur measurements and evaluated compared to conscript heights. The results indicate that mean male stature using Boldsen follows a similar trend as the Danish conscript heights and that Trotter overestimate stature by ca. 6cm over Boldsen. At an inter population level statistically significant differences in male stature are observed between first and second half of the 19th century towards a slight stature decrease and larger variation while there are no significant changes observed in female stature. There are insignificant differences in stature between middle and high class individuals, but male stature differs statistically between cemeteries (p=0.000) representing middle/high class, paupers and navy employees, respectively. Female stature had no significant wealth gradient (p=0.516). This study provides new evidence of stature among males and females during the 19th century and suggests that males may have been more sensitive to changes in environmental living and nutrition than females.

  5. [The comparison of the two Ottoman books of anatomy (17-19th centuries) with regard to the circulatory system].

    PubMed

    Uluçam, E; Gökçe, N

    2000-01-01

    17th and 19th centuries were particularly important for the development of the Ottoman medicine. Westernization which had already started in the 17th century continued along the 19th and the early 20th centuries. Turkish physicians began to contact with their European colleagues and in this period Latin medical terminology began to appear in the Ottoman medical literature. Sirvanli Semseddin Itaki's work of the 17th century, the Teşrihü'l Ebdan ve Tercüman-i Kibale-i Feylesufan, is the first illustrated Turkish manuscript of anatomy. The illustrations are qualified as developed examples, compared with the medical literature and knowledge of the period. In the 19th century, Sanizade Mehmet Ataullah Efendi (1771-1826) wrote a modern book of anatomy for the Ottoman medical doctors. Miyarü'l Etibba was one of the earliest printed medical books in Turkish. The second volume of Sanizade's Hamse, Miratü'l Ebdan fi Teşrih-i Azai'l Insan is the first printed Ottoman book on anatomy. In Usulü't-Tabia, the third volume of Hamse, the circulatory system is discussed. In this article, we studied the circulatory system described in Semseddin Itaki's Teşrih-ül Ebdan ve Tercüman-i Kibale-i Feylesufan and in Sanizade's Usulü't-Tabia and compared them.

  6. EDITORIAL: The 19th International Conference on Optical Fibre Sensors, OFS-19 The 19th International Conference on Optical Fibre Sensors, OFS-19

    NASA Astrophysics Data System (ADS)

    Sampson, David D.; Jones, Julian D. C.; Tatam, Ralph P.

    2009-03-01

    OFS-19 was held in April 2008 in Perth, Australia, with Professor David Sampson (University of Western Australia) as General Chair assisted by Technical Programme Co-Chairs Professor Stephen Collins (Victoria University, Australia), Professor Kyunghwan Oh (Yonsei University, Korea) and Dr Ryozo Yamauchi (Fujikura Ltd, Japan). 'OFS-19' has once again affirmed the OFS series as the leading international conference for the optical fibre sensor community. Since its inception, in London in 1983, and under the leadership of an international steering committee independent of any learned society or professional institution, it has been held approximately every eighteen months. The venue nominally rotates from Europe, to the Americas, and thence to Asia and the Pacific. OFS-19 demonstrated the continuing vigour of the community, with some 240 papers presented, plus 8 tutorials; submissions and attendance were from 29 countries, with a little over half coming from the Asia-Pacific Region. In recent years, it has become a tradition to publish a post-conference special issue in Measurement Science and Technology, and these special issues offer a representative sample of the current status of the field. In the 25 years since OFS began, many of the early ideas and laboratory-based proof-of-principle experiments have successfully evolved into highly developed instrumentation systems and commercial products. One of the greatest success stories has been the optical fibre Bragg grating. Its exquisite intrinsic sensitivity to temperature and strain has led to an expanding niche in structural monitoring, especially in civil engineering. It has formed the 'beach-head' for penetration of optical fibre sensors into the oil and gas industry, initially in the harsh environment of down-hole monitoring. Latterly, it has paved the way for new applications of one of the earliest fibre optic sensors, the fibre hydrophone, which is now making its mark in sub-sea seismic surveying. Additionally

  7. Changes in the geodiversity of Dutch peatlands inferred from 19th and 20th century landscape paintings

    NASA Astrophysics Data System (ADS)

    Jungerius, Pieter Dirk; van den Ancker, Hanneke; Wevers, Nina

    2013-04-01

    Geodiversity is the natural and cultural range of geological, geomorphological and soil features. We analysed the large database of 19th and early 20th century paintings of Simonis and Buunk (www.Simonis-Buunk.com) to track changes in the geodiversity of Dutch peatlands since pre-photographic times. Peat dominated in two of the eight main landscapes of the Netherlands: the Lowland peats in the Holocene west and the Highland peats in the sandy Pleistocene eastern parts. Painters were mainly attracted by the lowland peats. Since more than thousand years, peat plays a major role in Dutch military security, economy, ecology and cultural life. Natural variety and cultural use resulted in a geodiversity that is unique in Europe. There are more than 100 place names with 'veen' (= peat), and surnames with 'veen' are common. Proof of the exploitation of peat for salt and fuel exists from the Roman times onwards. In the 9th century, peatlands were drained and reclaimed for growing wheat. Already in the 11th century, it was necessary to build dikes to prevent flooding, to control waterlevels to avoid further oxidation, and to convert landuse to grassland. But subsidence continued, and in the 14th century windmills were needed to drain the lands and pump the water out. In the 16th century industrial peat exploitation fuelled the rise of industries and cities. All this draining and digging caused the peat surface to shrink. The few remaining living peats are conserved by nature organisations. Geodiversity and landscape paintings In the peat landscapes, popular painting motives were high water levels, the grasslands of the 'Green Heart', the winding streams and remaining lakes. The paintings of landscapes where peat had been removed, show watermanagement adaptations: wind mills, different water levels, canals made for the transport of fuel, bridges, tow paths and the 'plassen', i.e. the lakes left after peat exploitation. The droogmakerijen (reclaimed lakes), now 2 to 5 m below

  8. Summary of the 19th International Conference on Arabidopsis Research (July 23-27, 2008 in Montreal, Canada)

    SciTech Connect

    Schroeder, Julian I

    2009-10-01

    The 19th International Conference on Arabidopsis Research was a successful meeting attended by 815 scientists from around the world including 322 from the United States, 146 attendees from Canada, 179 from Europe, 134 from Asia, and 34 from a combination of Australia, South America, Africa and the Middle East. The scientific program was of excellent quality featuring 64 talks, including 41 from invited speakers. The Keynote Lecture, delivered by Chris Somerville (Energy Biosciences Institute/UC Berkeley) was particularly relevant to US agriculture and energy research and was titled The Development of Cellulosic Biofuels. There were also 6 community-organized workshops featuring 30 additional talks on topics including Frontiers in Plant Systems Biology, Sources and strategies for Gene Structure, Gene Function, and Metabolic Pathway annotation at TAIR and AraCyc, Advanced Bioinformatic Resources for Arabidopsis, Laser Microtechniques and Applications with Arabidopsis, Plant Proteomics- Tools, Approaches, Standards and Breakthroughs in Studying the Proteome, and Phytohormone Biosynthesis and Signal Transduction. Conference organizers arranged a special seminar by Jim Collins (head of the Directorate of Biosciences at NSF) to provide a community discussion forum regarding the future of Arabidopsis research. Approximately 575 posters were presented in topic areas including, among others, Development, Signal Transduction, Cell Walls, Non-Arabidopsis Systems, and Interactions with Biotic and Abiotic Factors. All conference abstracts and the full program are posted at The Arabidopsis Information Resource (TAIR), a publicly-accessibly website (www.arabidopsis.org/news/abstracts.jsp.) A survey completed by approximately 40% of the meeting attendees showed high satisfaction with the quality of the presentations, meeting organization and the city of Montreal. The conference is the largest annual international Arabidopsis venue which allowed the exchange of information at the

  9. Examining the ground layer of St. Anthony from Padua 19th century oil painting by Raman spectroscopy, scanning electron microscopy and X-ray diffraction

    NASA Astrophysics Data System (ADS)

    Vančo, Ľubomír; Kadlečíková, Magdaléna; Breza, Juraj; Čaplovič, Ľubomír; Gregor, Miloš

    2013-01-01

    In this paper we studied the material composition of the ground layer of a neoclassical painting. We used Raman spectroscopy (RS) as a prime method. Thereafter scanning electron microscopy combined with energy dispersive spectroscopy (SEM-EDS) and X-ray powder diffraction (XRD) were employed as complementary techniques. The painting inspected was of the side altar in King St. Stephen's Church in Galanta (Slovakia), signed and dated by Jos. Chr. Mayer 1870. Analysis was carried out on both covered and uncovered ground layers. Four principal compounds (barite, lead white, calcite, dolomite) and two minor compounds (sphalerite, quartz) were identified. This ground composition is consistent with the 19th century painting technique used in Central Europe consisting of white pigments and white fillers. Transformation of lead white occurred under laser irradiation. Subdominant Raman peaks of the components were measured. The observed results elucidate useful partnership of RS and SEM-EDS measurements supported by X-ray powder diffraction as well as possibilities and limitations of non-destructive analysis of covered lower layers by RS.

  10. Polynesia and polygenism: the scientific use of travel literature in the early 19th century.

    PubMed

    Carhart, Michael C

    2009-04-01

    Christoph Meiners (1747-1810) was one of 18th-century Europe's most important readers of global travel literature, and he has been credited as a founder of the disciplines of ethnology and anthropology. This article examines a part of his final work, "Untersuchungen über die Verschiedenheiten der Menschennaturen" [Inquiries on the differences of human natures], published posthumously in the 1810s. Here Meiners developed an elaborate argument, based on empirical evidence, that the different races of men emerged indigenously at different times and in different places in natural history. Specifically this article shows how a sedentary scholar who never left Europe constructed a narrative of human origins and migrations on the basis of (1) French theory from the 1750s (Charles de Brosses and Simon Pelloutier) and (2) data gathered by explorers as reported in travel literature (J.R. Forster, Pérouse, Cook, Marsden).

  11. An outbreak of cerebrospinal fever in a 19th century British Mediterranean naval base.

    PubMed

    Savona-Ventura, C

    1994-10-01

    Epidemic Meningococcal meningitis first made its definite appearance in Europe in the beginning of the nineteenth century. The first recorded epidemic in the Maltese Islands, which straddled the sea-routes of the Mediterranean, occurred in the late nineteenth century. This paper describes a manuscript report prepared at the request of the Lieutenant Governor regarding this epidemic in the light of the contemporary knowledge about the infection.

  12. [Mortality in Nuremberg in the 19th century (about 1800 to 1913)].

    PubMed

    Vasold, Manfred

    2006-01-01

    Before the middle of the 19th century urban life was hazardous, life expectancy in big cities was shorter than in the countryside, it was half as high as it is today. Cities used to be called "the graves of mankind"; they were unhygienic, since their inhabitants lived under crowded, unhealthy conditions. In German cities infant mortality was extremely high, one out of three new-born children died within its first year. In most big cities more people died in any given year than were born. In 1806, when the Imperial City of Nuremberg was absorbed by the Kingdom of Bavaria, it had 25 000 inhabitants, fewer than around the year 1600. In the following decades Nuremberg grew quickly, up to 50000 in 1846 and 100000 in 1881, 330000 in 1910. Its population was living extremely crowded within the medieval city-walls, up to 58 000 (1885) in the old parts of the city, more than twice as many as in 1806. Mortality was bound to increase, as more and more people moved to Nuremberg. Mortality rose from 25.5 per thousand in the 1820's to 29.4 in the 1850's and 32.8 in the 1860's. This increase of population was mainly due to migration from outside, from the countryside. New industries settled down in Nuremberg and provided new jobs, the new factories produced lots of smoke and dangerous dust. The general living conditions of the workers were poor, people were much smaller than nowadays. During the industrialisation labor was backbreaking, working hours were extremely long, and annual working hours were more than twice as long as today. New and better legislation was written by the Northern German Confederation, founded in 1867. Now the magistrate of Nuremberg recognised that something had to be done. In the following years physicians began to collect information as to morbidity and mortality in various parts of Nuremberg. Very many people still died of infectious diseases, esp. of tubercolosis, typhoid fever, diphtheria, pertussis, scarlet fever and other infectious diseases. There

  13. Human impacts of hydrometeorological extremes in the Bohemian-Moravian Highlands derived from documentary sources in the 18th-19th centuries

    NASA Astrophysics Data System (ADS)

    Dolák, Lukáš; Brázdil, Rudolf; Valášek, Hubert

    2014-05-01

    The extent of damage caused by hydrometeorological events or extremes (HME) has risen up in the entire world in the last few years. Especially the floods, flash floods, torrential rains and hailstorms are the most typical and one of the most frequent kind of natural disasters in the central Europe. Catastrophes are a part of human history and people were forced to cope with their consequences (e. g. material damage, economical losses, impacts on agriculture and society or losses of human lives). This paper analyses the human impacts of HME in the Bohemian-Moravian Highlands (central part of the Czech Republic) on the basis of documentary sources from the 18th-19th centuries. The paper presents various negative impacts of natural disasters on lives and property and subsequent inconveniences of Czech peasants. The preserved archival documents of estates or domains became the primary sources of data (e. g. taxation reliefs, damaged records, reports of afflicted farmers, administrative correspondence etc.). Particularly taxation reliefs relate to taxation system in the Czech lands during the 17th-19th centuries allowing to farmers to ask for tax alleviation when their crops were significantly damaged by any HME. These archival documents are a highly valuable source for the study of human impacts of natural disasters. Devastating consequences of these extremes affected individual farmers much more than the aristocracy. Floods caused inundations of farmer's fields, meadows, houses and farm buildings, washed away the arable land with crops, caused losses of cattle, clogged the land with gravel and mud and destroyed roads, bridges or agricultural equipment. Afflicted fields became worthless and it took them many years to become became fertile again. Crop was also damaged by hailstorms, droughts or late/early frosts. All these events led to lack of food and seeds in the following year and it meant the decrease of living standard, misery and poverty of farmers. Acquired

  14. On Ideas as Actors: How Ideas about Yellow Fever Causality Shaped Public Health Policy Responses in 19th-Century Galveston.

    PubMed

    Goldberg, Daniel S

    2012-01-01

    This article uses debates regarding yellow fever causality among leading healers in 19th-century Galveston, Texas, U.S., as a means of exploring the extent to which ideas are social actors. That is, the analysis demonstrates that ideas about yellow fever causality shaped contemporaneous public health policy responses to yellow fever outbreaks in 19th-century Galveston. The article contributes to the growing literature documenting that contagionist and anticontagionist views were often assimilated, and also supports the historiography showing that the predisposing/exciting causes dichotomy is a more robust intellectual framework for understanding 19th-century attributions of disease causality.

  15. EDITORIAL: The 18th European Workshop on Micromechanics (MME 07)

    NASA Astrophysics Data System (ADS)

    Correia, J. H.

    2008-06-01

    This special issue of Journal of Micromechanics and Microengineering is devoted to the 18th European Workshop on Micromechanics (MME 07), which took place at the University of Minho, Guimarães, Portugal from 16-18 September 2007. Since the first workshop at the University of Twente in 1989 the field of micromechanics has grown substantially and new fields have been added: optics, RF, biomedical, chemistry, and in recent years the emergence of nanotechnology. This year an extensive programme was scheduled with contributions from new materials research to new manufacturing techniques. In addition, the invited speakers presented a review of the state-of-the-art in several main trends in current research, with the focus on micro/nanosystems in the ICT Work Programme in EC FP7. As ever, the two day workshop was attended by delegates from all over Europe, the USA, Brazil, Egypt, Japan and Canada. A total of 96 papers were accepted for presentation and there were a further five keynote presentations. The workshop provides a forum for young researchers to learn about new experimental methods and to enhance their knowledge of the field. This special issue presents a selection of 17 of the best papers from the workshop. The papers highlight fluidic and optical devices, energy scavenging microsystems, neural probe arrays and microtechnology fabrication techniques. All the papers went through the regular reviewing procedure of IOP Publishing, and I am grateful to all the referees for their excellent work. I would also like to extend my thanks to Professor Robert Puers for advice on the final selection of papers and to Ian Forbes of IOP Publishing for managing the entire process. My thanks also go to the editorial staff of Journal of Micromechanics and Microengineering. I believe that this special issue will provide a good overview of the topics presented at the workshop and I hope you enjoy reading it.

  16. Nitrogen, land and water inputs in changing cattle farming systems. A historical comparison for France, 19th-21st centuries.

    PubMed

    Chatzimpiros, Petros; Barles, Sabine

    2010-09-15

    This paper provides an original account of the long-term regional metabolism in relation to the cattle rearing in western France starting by the precise formulation of animal diets at three key dates of the 19th, 20th and 21st centuries. We established links between the demand in fodder of the meat and dairy sectors and the necessary inputs of nitrogen, water and land as well as the land cover changes occurring on the affected local and remote cattle acreage. The average agricultural productivity for fodder supply is estimated at about 50 kg N/ha in the mid-19th, 54 kg N/ha in the early 20th and 150 kg N/ha at the turning of the 21st century. Jointly for the dairy and meat productions, the potential efficiency in the conversion of the vegetal into animal protein more than doubled over the studied period, passing from less than 9% in the 19th to 20% in the 21st century. The current cattle sector is sustained for about 25% by land situated beyond the regional frontiers and uses water at intensities that approach or exceed the availability of renewable water. The nitrogen pollution is expressed in terms of the Net Anthropogenic Nitrogen Inputs (NANI) and, by comparison to the N recovered in products, is used to define the N-Environmental Efficiency of the farming. We discuss the historical succession of the factors that contributed to the growth of the meat and milk production and make a comparison of the impacts and policy between the local and distant resources.

  17. A 920-kilometer optical fiber link for frequency metrology at the 19th decimal place.

    PubMed

    Predehl, K; Grosche, G; Raupach, S M F; Droste, S; Terra, O; Alnis, J; Legero, Th; Hänsch, T W; Udem, Th; Holzwarth, R; Schnatz, H

    2012-04-27

    Optical clocks show unprecedented accuracy, surpassing that of previously available clock systems by more than one order of magnitude. Precise intercomparisons will enable a variety of experiments, including tests of fundamental quantum physics and cosmology and applications in geodesy and navigation. Well-established, satellite-based techniques for microwave dissemination are not adequate to compare optical clocks. Here, we present phase-stabilized distribution of an optical frequency over 920 kilometers of telecommunication fiber. We used two antiparallel fiber links to determine their fractional frequency instability (modified Allan deviation) to 5 × 10(-15) in a 1-second integration time, reaching 10(-18) in less than 1000 seconds. For long integration times τ, the deviation from the expected frequency value has been constrained to within 4 × 10(-19). The link may serve as part of a Europe-wide optical frequency dissemination network.

  18. Micromechanics Analysis Code (MAC) Developed

    NASA Technical Reports Server (NTRS)

    1997-01-01

    The ability to accurately predict the thermomechanical deformation response of advanced composite materials continues to play an important role in the development of these strategic materials. Analytical models that predict the effective behavior of composites are used not only by engineers in performing structural analysis of large-scale composite components but also by material scientists in developing new material systems. For an analytical model to fulfill these two distinct functions, it must be based on a micromechanics approach that uses physically based deformation and life constitutive models, and it must allow one to generate the average (macro) response of a composite material given the properties of the individual constituents and their geometric arrangement. Only then can such a model be used by a material scientist to investigate the effect of different deformation mechanisms on the overall response of the composite and, thereby, identify the appropriate constituents for a given application. However, if a micromechanical model is to be used in a large-scale structural analysis it must be (1) computationally efficient, (2) able to generate accurate displacement and stress fields at both the macro and micro level, and (3) compatible with the finite element method. In addition, new advancements in processing and fabrication techniques now make it possible to engineer the architectures of these advanced composite systems. Full utilization of these emerging manufacturing capabilities require the development of a computationally efficient micromechanics analysis tool that can accurately predict the effect of microstructural details on the internal and macroscopic behavior of composites. Computational efficiency is required because (1) a large number of parameters must be varied in the course of engineering (or designing) composite materials and (2) the optimization of a material's microstructure requires that the micromechanics model be integrated with

  19. Analysis of 18th-19th century's historical samples of Iranian ink and paper belonging to the Qajar dynasty

    NASA Astrophysics Data System (ADS)

    Agha-Aligol, D.; Khosravi, F.; Lamehi-Rachti, M.; Baghizadeh, A.; Oliaiy, P.; Shokouhi, F.

    2007-11-01

    Thirteen historical Iranian manuscripts belonging to the Qajar dynasty (18th-19th Century BC) were investigated by micro-PIXE technique using Van de Graaff accelerator in the Nuclear Science & Technology Research Institute in Iran. The aim of the present work has mainly been to determine the elemental composition of different inks and papers. In addition, the effects due to the variation of thickness and texture of the paper were simultaneously measured with the off-axis STIM technique. Elemental maps by micro-PIXE were compared to photographs taken in visible light.

  20. Causes of mortality due to rheumatic diseases in Jerez de los Caballeros (Badajoz) during the 19th century.

    PubMed

    Peral Pacheco, Diego; Suárez-Guzmán, Francisco Javier

    2016-01-01

    A total of 26,203 of the deaths in Jerez de los Caballeros (Badajoz) during the 19th century were collected and grouped according to the Bertillon's Classification, in order to study the causes of death from rheumatic diseases. An analysis was made using the Death Registers, those located in the Parish Archives, and files of the Municipal Archives. There were a total of 31 deaths due to rheumatic diseases, with the 65-74 years age group being most frequent. The lack of records may be due to the inaccuracy of the diagnoses. September was the month of increased mortality.

  1. The influence of inequality on the standard of living: worldwide anthropometric evidence from the 19th and 20th centuries.

    PubMed

    Blum, Matthias

    2013-12-01

    We provide empirical evidence on the existence of the Pigou-Dalton principle. The latter indicates that aggregate welfare is - ceteris paribus - maximized when incomes of all individuals are equalized (and therefore marginal utility from income is as well). Using anthropometric panel data on 101 countries during the 19th and 20th centuries, we determine that there is a systematic negative and concave relationship between height inequality and average height. The robustness of this relationship is tested by means of several robustness checks, including two instrument variable regressions. These findings help to elucidate the impact of economic inequality on welfare.

  2. ["The mind-body problem". The relation of psychical to physical in 19th century German psychology].

    PubMed

    Romand, David

    2010-01-01

    During the 19th century, the question of the relation between the soul and the body was deeply renewed by German psychological studies. The new elaborated conception of the relationship between the psychical and the physical coincides with the appearance of a cognitivist paradigm, in which mental phenomena are considered as entities that may be individualised, isolated, and then correlated with the activity of specific neural substrates. German psychologists were confronted with the problem of the correlation between psychical life and the nervous system (localisation of mental phenomena and nature of this correlative relationship), and propose an extensive analysis on the neural conditions and the emergence of psychical processes.

  3. An archival exploration of homicide--suicide and mass murder in the context of 19th-century American parricides.

    PubMed

    Shon, Phillip Chong Ho; Roberts, Michael A

    2010-02-01

    There has been little attempt to integrate contemporary studies of suicide and mass murder to homicide-suicides. The current research attempts to do so in the context of 19th-century parricides in America. This project uses archival records from The New York Times and the Chicago Tribune, 1851-1899, resulting in a total of 231 incidents. Our results indicate that parricides, mass murders, and suicides tended to originate as spontaneous acts, usually during the course of an argument, gathering momentum as the interaction unfolded. We contend that suicide is one way of alleviating threats to offender's loss of self-identity.

  4. An early 19th-century Canadian surgical practice: the casebook of John Mackieson of Charlottetown, 1795–1885

    PubMed Central

    Shephard, David A.E.; Grogono, Basil J.S.

    2002-01-01

    A casebook written by Dr. John Mackieson (1795–1885), of Charlottetown, contains the records of 49 surgical cases he managed between 1826 and 1857. In view of the rarity of first-hand accounts of surgical practice in Canada in the mid-19th century, Mackieson’s case records are a significant source of information. These cases are discussed in order to delineate Mackieson’s approach to the surgical problems he faced in his general practice. His case records also illustrate some of the general problems that beset surgeons in that era. PMID:11939660

  5. An international effort to cure a global health problem: A report on the 19th Hemoglobin Switching Conference.

    PubMed

    Blobel, Gerd A; Bodine, David; Brand, Marjorie; Crispino, John; de Bruijn, Marella F T R; Nathan, David; Papayannopoulou, Thalia; Porcher, Catherine; Strouboulis, John; Zon, Len; Higgs, Douglas R; Stamatoyannopoulos, George; Engel, James Douglas

    2015-10-01

    Every 2 years since 1978, an international group of scientists, physicians, and other researchers meet to discuss the latest developments in the underlying etiology, mechanisms of action, and developmental acquisition of cellular and systemic defects exhibited and elicited by the most common inherited human disorders, the hemoglobinopathies. The 19th Hemoglobin Switching Conference, held in September 2014 at St. John's College in Oxford, once again exceeded all expectations by describing cutting edge research in cellular, molecular, developmental, and genomic advances focused on these diseases. The conference comprised about 60 short talks over 3 days by leading investigators in the field. This meeting report describes the highlights of the conference.

  6. Clinical Anatomy of the Liver: Review of the 19th Meeting of the Japanese Research Society of Clinical Anatomy

    PubMed Central

    Sakamoto, Yoshihiro; Kokudo, Norihiro; Kawaguchi, Yoshikuni; Akita, Keiichi

    2017-01-01

    Precise clinical knowledge of liver anatomy is required to safely perform a hepatectomy, for both open and laparoscopic surgery. At the 19th meeting of the Japanese Research Society of Clinical Anatomy (JRSCA), we conducted special symposia on essential issues of liver surgery, such as the history of hepatic segmentation, the glissonean pedicle approach, application of 3-D imaging simulation and fluorescent imaging using indocyanine green solution, a variety of segmentectomies including caudate lobectomy, the associating liver partition and portal vein embolization for stage hepatectomy and harvesting liver grafts for living donor liver transplantation. The present review article provides useful information for liver surgeons and anatomic researchers. PMID:28275581

  7. Micromechanical Analyses of Sturzstroms

    NASA Astrophysics Data System (ADS)

    Imre, Bernd; Laue, Jan; Springman, Sarah M.

    2010-05-01

    have been made observable and reproducible within a physical and a distinct element numerical modelling environment (DEM). As link between field evidence gained from the deposits of natural sturzstroms, the physical model within the ETH Geotechnical Drum Centrifuge (Springman et al., 2001) and the numerical model PFC-3D (Cundall and Strack, 1979; Itasca, 2005), serves a deterministic fractal analytical comminution model (Sammis et al., 1987; Steacy and Sammis, 1991). This approach allowed studying the effects of dynamic fragmentation within sturzstroms at true (macro) scale within the distinct element model, by allowing for a micro-mechanical, distinct particle based, and cyclic description of fragmentation at the same time, without losing significant computational efficiency. Theses experiments indicate rock mass and boundary conditions, which allow an alternating fragmenting and dilating dispersive regime to evolve and to be sustained long enough to replicate the spreading and run out of sturzstroms. The fragmenting spreading model supported here is able to explain the run out of a dry granular flow, beyond the travel distance predicted by a Coulomb frictional sliding model, without resorting to explanations by mechanics that can only be valid for certain, specific of the boundary conditions. The implications derived suggest that a sturzstrom, because of its strong relation to internal fractal fragmentation and other inertial effects, constitutes a landslide category of its own. Its mechanics differ significantly from all other gravity driven mass flows. This proposition does not exclude the possible appearance of frictionites, Toma hills or suspension flows etc., but it considers them as secondary features. The application of a fractal comminution model to describe natural and experimental sturzstrom deposits turned out to be a useful tool for sturzstrom research. Implemented within the DEM, it allows simulating the key features of sturzstrom successfully and

  8. Micromechanics of cellularized biopolymer networks

    PubMed Central

    Jones, Christopher A. R.; Cibula, Matthew; Feng, Jingchen; Krnacik, Emma A.; McIntyre, David H.; Levine, Herbert; Sun, Bo

    2015-01-01

    Collagen gels are widely used in experiments on cell mechanics because they mimic the extracellular matrix in physiological conditions. Collagen gels are often characterized by their bulk rheology; however, variations in the collagen fiber microstructure and cell adhesion forces cause the mechanical properties to be inhomogeneous at the cellular scale. We study the mechanics of type I collagen on the scale of tens to hundreds of microns by using holographic optical tweezers to apply pN forces to microparticles embedded in the collagen fiber network. We find that in response to optical forces, particle displacements are inhomogeneous, anisotropic, and asymmetric. Gels prepared at 21 °C and 37 °C show qualitative difference in their micromechanical characteristics. We also demonstrate that contracting cells remodel the micromechanics of their surrounding extracellular matrix in a strain- and distance-dependent manner. To further understand the micromechanics of cellularized extracellular matrix, we have constructed a computational model which reproduces the main experiment findings. PMID:26324923

  9. Early diagnosis of neurodegenerative diseases - the long awaited Holy Grail and bottleneck of modern brain research - 19th HUPO BPP workshop: May 22-24, 2013, Dortmund, Germany.

    PubMed

    Schrötter, Andreas; Magraoui, Fouzi El; Gröttrup, Bernd; Wiltfang, Jens; Heinsen, Helmut; Marcus, Katrin; Meyer, Helmut E; Grinberg, Lea T; Park, Young Mok

    2013-10-01

    The HUPO Brain Proteome Project (HUPO BPP) held its 19th workshop in Dortmund, Germany, from May 22 to 24, 2013. The focus of the spring workshop was on strategies and developments concerning early diagnosis of neurodegenerative diseases.

  10. Medical and Social Aspects of Syphilis in the Balkans from the mid-19th Century to the Interwar.

    PubMed

    Tsiamis, Costas; Vrioni, Georgia; Poulakou-Rebelakou, Effie; Gennimata, Vasiliki; Murdjeva, Mariana А; Tsakris, Athanasios

    2016-03-01

    The current study presents some aspects of syphilis in the Balkan Peninsula from the 19th century until the Interwar. Ever since the birth of modern Balkan States (Greece, Bulgaria, Turkey and Serbia), urbanization, poverty and the frequent wars have been considered the major factors conducive to the spread of syphilis. The measures against sex work and sexually transmitted diseases (STDs) were taken in two aspects, one medical and the other legislative. In this period, numerous hospitals for venereal diseases were established in the Balkan countries. In line with the international diagnostic approach and therapeutic standards, laboratory examinations in these Balkan hospitals included spirochete examination, Wassermann reaction, precipitation reaction and cerebrospinal fluid examination. Despite the strict legislation and the adoption of relevant laws against illegal sex work, public health services were unable to curb the spread of syphilis. Medical and social factors such as poverty, citizen's ignorance of STDs, misguided medical perceptions, lack of sanitary control of prostitution and epidemiological studies, are highlighted in this study. These factors were the major causes that helped syphilis spread in the Balkan countries during the 19th and early 20th century. The value of these aspects as a historic paradigm is diachronic. Failure to comply with the laws and the dysfunction of public services during periods of war or socioeconomic crises are both factors facilitating the spread of STDs.

  11. Sleepwalking in Italian operas: a window on popular and scientific knowledge on sleep disorders in the 19th century.

    PubMed

    Riva, Michele Augusto; Sironi, Vittorio Alessandro; Tremolizzo, Lucio; Lombardi, Carolina; De Vito, Giovanni; Ferrarese, Carlo; Cesana, Giancarlo

    2010-01-01

    There is little knowledge on sleepwalking in ancient times even though it is a very common condition. The aim of this report is to describe the backgrounds of medical knowledge on somnambulism in the 19th century, a key period in the development of neurosciences, by analysing its representation in two famous Italian operas: La Sonnambula by Vincenzo Bellini and Macbeth by Giuseppe Verdi. The 19th-century operas may be considered as a crossing point between the popular and intellectual world because they mirror popular answers to phenomena that were still awaiting scientific explanations. Shakespeare's play Macbeth was also considered. In Shakespeare's play and in Verdi's Macbeth, sleepwalking is looked upon as a neuropsychiatric disorder, a manifestation of internal anxiety. In La Sonnambula by Bellini, this condition is considered as common disorder that anticipates scientific theories. The analysed Italian operas provide two different views on sleepwalking, probably because they are based on texts belonging to different periods. Their examination allows one to understand the gradual evolution of theories on sleepwalking, from demoniac possession to mental disorder and sleep disease. At the same time, this analysis throws some light on the history of psychological illnesses.

  12. Improvement of health care for the poor in Split (southern Croatia) during the first half of the 19th century.

    PubMed

    Brisky, Livia; Brisky, Tibor

    2011-12-01

    The aim of this study was to investigate the health care available for the poor citizens of Split during the first half of the 19th century. Soon after being constructed in 1797, the Civic Hospital in Split founded by the Ergovac brothers for the needs of the poor was transformed into a military hospital. Consequently, caring for this social stratum was taken over by two inadequate shelters and later by a small civic hospital situated in the Split suburb of Dobri. The year of the application of Petar Ergovac to the supreme ruler for the transformation of the hospital building established by his family from a military to a civil institution was found, as well as the correct data regarding its return to initial idea in 1821. On the basis of the archival documents kept in the Archaeological Museum in Split and in the State Archives in Zadar, the work organization of the Civic Hospital in Split and the first stage of its change from a charitable to a public health hospital institution were presented. This study revealed the aspiration of the authorities in the first half of the 19th century to improve the health system of the city of Split.

  13. Medical diagnosis of legal culpability: the impact of early psychiatric testimony in the 19th century English criminal trial.

    PubMed

    Toole, Ciara J

    2012-01-01

    Fast-paced developments in psychiatry, neuroscience and emerging neuroimaging technologies place continual pressure on the legal recognition of mental illness and disease across jurisdictional boundaries. Nevertheless, the Canadian legal definition of exculpatory mental disease in the context of criminal liability has remained largely static, sheltered from the immediate influence of medical theory and advancements. In order to effectively reflect on the intersection of mental health and criminal justice systems in this area, it is important to understand its historical development and the English common law origins of the current approach. Specifically turning to the early 19th century, documented history and accounts of early medical witness testimony on the mental state of the accused provide a unique opportunity to understand the initial collision between fundamental concepts of moral and legal culpability and new scientific understandings of mental function and disease. In this article, I suggest that early psychiatric testimony to the accused's mental state challenged the evolving criminal law of 19th century England to reconcile its restrictive definition of "insanity" with expanding scientific reasoning and accounts of mental disease. The trial of Edward Oxford, an attempted royal assassination case of 1840, is examined as a symbolic height in this conflict prior to the first common law pronouncement of the current approach in 1843. As debate continues on the role of medical advancement in the identification of exculpatory medical disorders in law, this historical perspective may serve as a touchstone in balancing the enforcement of legal culpability with our society's greater appreciation for mental illness.

  14. Evolution of disability in late 19th century America: Civil War pensions for Union Army veterans with musculoskeletal conditions.

    PubMed

    Blanck, Peter; Linares, Claudia; Song, Chen

    2002-01-01

    This article examines the evolution of musculoskeletal (MSK) disability and its impact on mortality and work patterns in the late 19th century in America, in the context of the Civil War disability policy scheme. The study was conducted on 17,702 Union Army (UA) Civil War veterans. Of these, 10,789 were examined and diagnosed with major MSK conditions, rheumatism, sciatica, and spinal curvature, between 1862 and 1907. Analyses examine MSK (i) prevalence rates by birth cohort and age group; (ii) fatality rates as compared with other disabilities; (iii) risk rates by occupation type; and (iv) lifespan for MSK patients. MSK conditions are commonly claimed disabilities within the Civil War data set, with prevalence rates increasing with age. Regression studies show that working in clerical and professional (relative to manual labor) occupations decreases the likelihood of being examined for and diagnosed with MSK conditions. MSK patients examined at older ages tended to have longer lifespan than those examined at younger ages. The findings suggest that changes in age, environmental, and occupational conditions during the late 19th century affected MSK condition prevalence and the average lifespan of MSK patients. Implications for contemporary disability policy are discussed.

  15. Anthropometric comparison of portraits of Korean and Japanese beauty in the late 18th and early 19th centuries.

    PubMed

    Hwang, Kun; Hwang, Se Ho

    2005-09-01

    The aim of this study is to elaborate comparative portraits of Korean and Japanese beauty in the late 18th and early 19th centuries. Six portraits of beauty in the Korean Joseon Dynasty (early 19th century) and 5 in Japanese Edo Dynasty (late 18th century) were analyzed. Twenty anthropometric items were applied to the measure of the features on each portrait and 18 proportional indices of the face were calculated. Among the 18 indices, Korean and Japanese beauty did not show any significant differences in 13, but in 5: 1) the ratio of eye fissure to intercanthal distance was greater in Japanese beauty; 2) eye inclination was greater in Japanese beauty; 3) the ratio of nasal width to intercanthal distance was greater in Japanese beauty; 4) the ratio of nasal and facial width was greater in Korean beauty; and 5) the ratio of vermilion size to mouth width was greater in Japanese beauty. It is assumed that Korean had narrower eye fissure, lower eye inclination, wider nasal ala, and thinner lip than what Japanese craved during that era.

  16. A light on medical practice in 19th-century Canada: the medical manuscripts of Dr. John Mackieson of Charlottetown

    PubMed Central

    Shephard, D A

    1998-01-01

    During his long career as a physician in Charlottetown, Dr. John Mackieson (1795-1885) compiled 4 medical manuscripts: 2 sets of case records, a synopsis of the medical conditions that were common in his day and a formulary. As primary sources, these documents provide information about medicine in 19th-century Canada and augment our knowledge of the problems of medical practice in that era. They illustrate aspects of the work of Dr. Mackieson, a generalist with interests in surgery and obstetrics, and they facilitate an understanding of the rationale underlying the treatments that he and his contemporaries used. Although 150 years old, the case records can be appreciated for their relevance to the art of medicine. Two excerpts from the case records, presented in this article, provide a sense of Dr. Mackieson's writings and introduce a discussion on the significance of these manuscripts in relation to the ideas on disease and treatment that governed medical practice, both in Prince Edward Island and elsewhere in Canada, in the 19th century. PMID:9724982

  17. [Historical sketch of modern pharmaceutical science and technology (Part 3). From the second half of the 19th century to World War II].

    PubMed

    Yamakawa, K

    1995-01-01

    The history of modern pharmaceutical science and technology, from the second half of the 19th century to the end of World War II, is divided into nine sections for the purpose of discussion. 1. The European medical and pharmaceutical science and technology at the end of the 19th century is reviewed. Pharmacology, bacteriology and biochemistry were built in this period. 2. The Meiji Government accepted Western medicine and medical law and regulations in 1883. Consequently, the Japanese physician changed from Eastern (Kanpooi) to Western (Seiyooi). 3. Modern scientific and engineering education had been accepted in America, England, Germany, and France etc. Foreign scientists and engineers (Oyatoi-gai-kokujin) were educated by practice and theory. The Faculty of Engineering was established in the universities in Japan. This fact is one of the differences in the history of universities in Europe and America. 4. Pharmaceutical education in the Meiji period (1873-1911). Twenty-nine schools of pharmacy were built in this period. However, 20 schools of pharmacy had been closed. Pharmacy and pharmaceutical industry was not established in the Meiji era. 5. The profession of pharmacist in 1873-1944. The policy of medicine was changed by the Meiji Government in 1889, when Western physicians were allowed to prepare medicines for patients, and this practice continues today. Political and technological power of Japanese pharmacists was weak, so their role was not estimated. 6. Consequences of world War I, and the establishment of the pharmaceutical industry. The Sino-Japanese War (1894-95) and Russo-Japanese War (1904-05) were won fortunately. The first pharmaceutical company was established in 1885. At this times, many pharmaceutical manufacturing companies, which were converted from whole sale merchants, were built. Then started the manufacturing of commercial drugs. 7. Hygienic chemistry and some problems of public hygiene. The causes of diseses unique to Japan, such as

  18. Method for preventing micromechanical structures from adhering to another object

    DOEpatents

    Smith, J.H.; Ricco, A.J.

    1998-06-16

    A method for preventing micromechanical structures from adhering to another object includes the step of immersing a micromechanical structure and its associated substrate in a chemical species that does not stick to itself. The method can be employed during the manufacture of micromechanical structures to prevent micromechanical parts from sticking or adhering to one another and their associated substrate surface. 3 figs.

  19. Evidence of active dune sand on the Great Plains in the 19th century from accounts of early explorers

    USGS Publications Warehouse

    Muhs, D.R.; Holliday, V.T.

    1995-01-01

    Dune fields are found in several areas of the Great Plains, and though mostly stabilised today, the accounts of early explorers show that they were more mobile in the last century. Using an index of dune mobility and tree ring data, it is found that these periods of mobility were related to temperature-induced drought, the high temperatures increasing evapotranspiration. Explorers also record that rivers upwind of these dune fields had shallow braided channels in the 19th century, and these would have supplied further aeolian sand. It is concluded that these dunes are extremely susceptible to climate change and that it may not need global warming to increase their mobility again. -K.Clayton

  20. [Military Knowledge: War Sciences and Army Libraries in France in the 19th Century (c. 1800-c. 1900)].

    PubMed

    Thoral, Marie-Cecile

    2015-01-01

    This article analyses the development of military knowledge in France in the 19th century, both in terms of production of knowledge (especially through the Dépôt de la Guerre) and of transmission through a network of army libraries. The strategic dimension of this form of knowledge required a direct intervention of the state, to control or restrict the publication of sensitive data. State intervention was also necessary to coordinate and generate a unified, applied military knowledge using data submitted by members of different army branches, or by civilians. The work of military librarians and bibliologists was all the more difficult because of the very wide range of sciences which could be used by the army. Growing state intervention and public funding were thus essential for the production and transmission of military knowledge.

  1. The dentist's armamentarium: a collection of 19th century instruments in the Louisiana State University School of Dentistry Library.

    PubMed

    Cheramie, Toby J; Strother, Elizabeth A

    2008-01-01

    A small collection of antique dental instruments located in the LSU School of Dentistry Library (LSUSD) provides a glimpse into the world of the 19th century dentist. The instruments in this collection, with handles carved from common and rare early materials such as bone, wood, ivory, ebony, cameo, shell and pearl, provide a striking contrast to all-steel instruments of the 20th century. An understanding of their development and function substantially increases appreciation of these instruments, which can be categorized as instruments for oral surgery, prophylaxis, restoration, and general use. In this article, the authors summarize the historical development of each type of instrument and describe the specific items in the LSUSD Library collection.

  2. Geologic and hydrologic hazards in glacierized basins in North America resulting from 19th and 20th century global warming

    USGS Publications Warehouse

    O'Connor, J. E.; Costa, J.E.

    1993-01-01

    Alpine glacier retreat resulting from global warming since the close of the Little Ice Age in the 19th and 20th centuries has increased the risk and incidence of some geologic and hydrologic hazards in mountainous alpine regions of North America. Abundant loose debris in recently deglaciated areas at the toe of alpine glaciers provides a ready source of sediment during rainstorms or outburst floods. This sediment can cause debris flows and sedimentation problems in downstream areas. Moraines built during the Little Ice Age can trap and store large volumes of water. These natural dams have no controlled outlets and can fail without warning. Many glacier-dammed lakes have grown in size, while ice dams have shrunk, resulting in greater risks of ice-dam failure. The retreat and thinning of glacier ice has left oversteepened, unstable valley walls and has led to increased incidence of rock and debris avalanches. ?? 1993 Kluwer Academic Publishers.

  3. [The delayed emergence of the printing chronograph in French observatories (late 19th - early 20th centuries].

    PubMed

    Lamy, Jérôme; Soulu, Frédéric

    2015-01-01

    Western observatories became scientific factories from the mid-19th century. Astrometry symbolized the transition to an industrious economy of scientific practices. The printing chronograph, which reduced the personal equations of the observers, was, first in the United States, then in England, the symbolic instrument of this transformation. In France, the initiatives of the astronomer Liais were prototypical. In the practices of the Hendaye Observatory, and thanks to the abbé Verschaffel, the printing chronograph made its definitive entry in French observatories at the beginning of the 20th century. Excessive centralization of French astronomy, the authoritarianism of Urbain Le Verrier, the director of the Paris Observatory, and the poor market for scientific instruments explain why the printing chronograph took root, belatedly, in France.

  4. From facial expressions to bodily gestures: Passions, photography and movement in French 19(th)-century sciences.

    PubMed

    Pichel, Beatriz

    2016-02-01

    This article aims to determine to what extent photographic practices in psychology, psychiatry and physiology contributed to the definition of the external bodily signs of passions and emotions in the second half of the 19(th) century in France. Bridging the gap between recent research in the history of emotions and photographic history, the following analyses focus on the photographic production of scientists and photographers who made significant contributions to the study of expressions and gestures, namely Duchenne de Boulogne, Charles Darwin, Paul Richer and Albert Londe. This article argues that photography became a key technology in their works due to the adequateness of the exposure time of different cameras to the duration of the bodily manifestations to be recorded, and that these uses constituted facial expressions and bodily gestures as particular objects for the scientific study.

  5. [Traces of blood. The significance of blood in criminology at the turn of the 19th century].

    PubMed

    Bachhiesl, Christian

    2010-03-01

    In late 19th and early 20th century, criminology became institutionalized as an independent branch of science. Methodologically it focused on the 'exact' methods of the natural sciences, but also it tried to integrate the methods of the humanities. This mix of methods becomes visible in the treatment of blood, which on the one hand was an object of then brand new methods of scientific analysis (identification of human blood by the biological or precipitin method), and on the other hand was analyzed as a product of the magic and superstitious mentalities of criminals. The methodical tension resulting from this epistemological crossbreeding did not disturb the criminologists, for whom the reconciliation of opposite ways of thinking and researching seemed to be possible. In this encyclopaedic analysis of blood early criminology tried to combine the anthropological exploration of vampirism with the chemical and microscopic detection of antibodies and haemoglobin, thus mirroring the positivistic optimism that was then prevalent.

  6. The black cholera comes to the central valley of America in the 19th century - 1832, 1849, and later.

    PubMed

    Daly, Walter J

    2008-01-01

    In mid-19th Century, cholera was epidemic throughout the world. Small towns of the American Midwest were not spared. The disease was blamed on miasmas arising from local causes, so flight from affected localities were logical and common. Flight, added to mortality, caused virtual depopulation of many small towns. Drinking water was drawn from rivers or shallow wells, often near seeping cesspools. Local merchants tried unsuccessfully to calm panic by suppressing information. Cholera was not good for business. Business was depressed. Organized religion thrived. National and state days of prayer were appointed to appease an angry God. During these frightening times, the people learned nothing about the infectiousness of cholera or about its prevention through sanitation. Their experiences tended to reinforce their belief in miasmas or divine retribution. The great epidemics of mankind describe human behavior in times of unavoidable and incurable crisis. Nineteenth Century cholera experiences illustrate a people's reaction to catastrophic disease, which they believed was incurable and unpreventable.

  7. Paleontology and Darwin's Theory of Evolution: The Subversive Role of Statistics at the End of the 19th Century.

    PubMed

    Tamborini, Marco

    2015-11-01

    This paper examines the subversive role of statistics paleontology at the end of the 19th and the beginning of the 20th centuries. In particular, I will focus on German paleontology and its relationship with statistics. I argue that in paleontology, the quantitative method was questioned and strongly limited by the first decade of the 20th century because, as its opponents noted, when the fossil record is treated statistically, it was found to generate results openly in conflict with the Darwinian theory of evolution. Essentially, statistics questions the gradual mode of evolution and the role of natural selection. The main objections to statistics were addressed during the meetings at the Kaiserlich-Königliche Geologische Reichsanstalt in Vienna in the 1880s. After having introduced the statistical treatment of the fossil record, I will use the works of Charles Léo Lesquereux (1806-1889), Joachim Barrande (1799-1833), and Henry Shaler Williams (1847-1918) to compare the objections raised in Vienna with how the statistical treatment of the data worked in practice. Furthermore, I will discuss the criticisms of Melchior Neumayr (1845-1890), one of the leading German opponents of statistical paleontology, to show why, and to what extent, statistics were questioned in Vienna. The final part of this paper considers what paleontologists can derive from a statistical notion of data: the necessity of opening a discussion about the completeness and nature of the paleontological data. The Vienna discussion about which method paleontologists should follow offers an interesting case study in order to understand the epistemic tensions within paleontology surrounding Darwin's theory as well as the variety of non-Darwinian alternatives that emerged from the statistical treatment of the fossil record at the end of the 19th century.

  8. Effect of hemostasis and electrosurgery on the development and evolution of brain tumor surgery in the late 19th and early 20th centuries.

    PubMed

    Vender, John R; Miller, Jason; Rekito, Andy; McDonnell, Dennis E

    2005-04-15

    Hemostatic options available to the surgeon in the late 19th and early 20th centuries were limited. The surgical ligature was limited in value to the neurological surgeon because of the unique structural composition of brain tissue as well as the approaches and operating angles used in this type of surgery. In this manuscript the authors review the options available and the evolution of surgical hemostatic techniques and electrosurgery in the late 19th and early 20th centuries and the impact of these methods on the surgical management of tumors of the brain and its coverings.

  9. Micromechanical Evaluation of Ceramic Matrix Composites

    DTIC Science & Technology

    1991-02-01

    Materials Sciences Corporation AD-A236 756 M.hM. 9 1 0513 IEIN HIfINU IIl- DTIC JUN 06 1991 MICROMECHANICAL EVALUATION OF S 0 CERAMIC MATRIX COMPOSITES C...Classification) \\() Micromechanical Evaluation of Ceramic Matrix Composites ) 12. PERSONAL AUTHOR(S) C-F. Yen, Z. Hashin, C. Laird, B.W. Rosen, Z. Wang 13a. TYPE...and strengthen the ceramic composites. In this task, various possibilities of crack propagation in unidirectional ceramic matrix composites under

  10. [Development of animal husbandry in Groningen in the 18th and 19th century; a broad outline].

    PubMed

    Paping, R F

    2001-01-01

    This overview is mainly focussed on the clay area forming the northern half of the province. It is the wealthiest and most characteristic part, being cultured since the Middle Ages as testified by the many churches that even small villages were able to construct. About 1700 the province of Groningen enjoyed already a modern economy, fitting in with that of the other coastal areas of Friesland, Zeeland and Holland (the last mentioned was the richest region of the world in the 17th and 18th century). As aspects of modernity at that time can be considered: 1) the use of modern agricultural methods with higher yields per hectare and higher milk yields per cow than produced in the land provinces on the sandy soils; 2) Agriculture was aimed at earning money by selling of hte products. In opposition to the farmers in the land provinces, who mainly produced for subsistence farming, the farmers in the coastal areas produced for the trade; 3) A high degree of specialization was found in the rural areas. 30-40% of the families had own farms, 25% of the population were labourers, owing only small pieces of land and the rest of the working population had occupations outside agriculture (craftmen, shopkeepers, shipmasters, merchants etc.). Whereas on the sandy soils practically every family owned a farm, be it mostly a very small one. After reviewing the changes in the distribution of land in use of the production of fieldcrops or for meadows-always in function of the market value of the products-and after a discussion of type of cattle husbandry (breeding, fattening, dairying) it is concluded that a relative decrease of the importance of cattle husbandry in the clay region during the 18th - 19th century can be observed. Intensification of land use had a positive effect on crop-production. The much-heard opinion that the cattle plague epizootic of 1768-1786 caused a transition in land use through a switch from animal husbandry to arable farming, is not held by the author

  11. Embryonic development of chicken (Gallus Gallus Domesticus) from 1st to 19th day-ectodermal structures.

    PubMed

    Toledo Fonseca, Erika; De Oliveira Silva, Fernanda Menezes; Alcântara, Dayane; Carvalho Cardoso, Rafael; Luís Franciolli, André; Sarmento, Carlos Alberto Palmeira; Fratini, Paula; José Piantino Ferreira, Antônio; Miglino, Maria Angélica

    2013-12-01

    Birds occupy a prominent place in the Brazilian economy not only in the poultry industry but also as an animal model in many areas of scientific research. Thus the aim of this study was to provide a description of macro and microscopic aspects of the ectoderm-derived structures in chicken embryos / fetuses poultry (Gallus gallus domesticus) from 1st to 19th day of incubation. 40 fertilized eggs, from a strain of domestic chickens, with an incubation period of 2-19 days were subjected to macroscopic description, biometrics, light, and scanning microscopy. All changes observed during the development were described. The nervous system, skin and appendages and organs related to vision and hearing began to be identified, both macro and microscopically, from the second day of incubation. The vesicles from the primitive central nervous system-forebrain, midbrain, and hindbrain-were identified on the third day of incubation. On the sixth day of incubation, there was a clear vascularization of the skin. The optic vesicle was first observed fourth day of development and on the fifth day there was the beginning of the lens formation. Although embryonic development is influenced by animal line as well as external factors such as incubation temperature, this paper provides a chronological description for chicken (Gallus gallus domesticus) during its embryonic development.

  12. From Coin to Medal: A Metallurgical Study of the Brazing Drop on a 19th Century Scudo

    NASA Astrophysics Data System (ADS)

    Breda, M.; Canovaro, C.; Pérez, A. F. Miranda; Calliari, I.

    2012-11-01

    In the past, it was customary to use out-of-circulation coins as pendants by brazing a peg or ring on the edge of the coin in order to transform it into a devotional or decorative object; this practice was very common for specimens of the Papal States, especially for silver coins. This metallurgical investigation of a 19th century Scudo aimed to relate the internal structure of the coin to the minting technology with a special focus on the brazing drop, in order to provide information on the solidification microstructure arising from a strongly nonequilibrium process such as brazing. The results show that the Ag content in the coin ranges from 92% in the bulk up to 97% on the surface, due to enrichment, while analysis of the brazing revealed that it consists of an Ag-Cu-Zn-Pb alloy, for which the melting temperature has been estimated. Considering the distribution of minor elements, Zn segregates in the secondary (Cu-rich) β-dendrites and inside the whole eutectic structure, while Pb is only present in the Ag-based phases and seems to reduce the solubility of Zn inside the primary (Ag-rich) α-dendrites.

  13. Scurvy in the British Mercantile Marine in the 19th century, and the contribution of the Seamen's Hospital Society.

    PubMed

    Cook, G C

    2004-04-01

    When long voyages in sailing vessels were commonplace, scurvy was a major health hazard in mariners of all nations. The observations of James Lind (1716-94) and others indicated that citrus fruits had both a preventive and curative role in this disease. In the light of this work, by 1800 the disease had been virtually eliminated from Britain's Royal Navy. However, it continued in the merchant navies of all nations until the latter half of the 19th century. In 1867, the Merchant Shipping Amendment Act was passed by the British Parliament largely as a result of a concerted effort by the Seamen's Hospital Society (SHS), one of whose physicians, Harry Leach (1836-79) was the major proselytiser for improved conditions in the merchant service. Examination of the SHS records before and after this event demonstrate a marked reduction in the prevalence of scurvy in the Port of London. Although other factors-such as the introduction of steam ships, which resulted in faster voyages-were clearly important, the compulsory administration of genuine lime juice under supervision in the merchant service seems to have exerted a significant effect.

  14. Quantifying pollen-vegetation relationships to reconstruct forests using 19th-century forest composition and pollen data

    USGS Publications Warehouse

    Dawson, Andria; Paciorek, Christopher J.; McLachlan, Jason S.; Goring, Simon; Williams, John W.; Jackson, Stephen T.

    2016-01-01

    Mitigation of climate change and adaptation to its effects relies partly on how effectively land-atmosphere interactions can be quantified. Quantifying composition of past forest ecosystems can help understand processes governing forest dynamics in a changing world. Fossil pollen data provide information about past forest composition, but rigorous interpretation requires development of pollen-vegetation models (PVMs) that account for interspecific differences in pollen production and dispersal. Widespread and intensified land-use over the 19th and 20th centuries may have altered pollen-vegetation relationships. Here we use STEPPS, a Bayesian hierarchical spatial PVM, to estimate key process parameters and associated uncertainties in the pollen-vegetation relationship. We apply alternate dispersal kernels, and calibrate STEPPS using a newly developed Euro-American settlement-era calibration data set constructed from Public Land Survey data and fossil pollen samples matched to the settlement-era using expert elicitation. Models based on the inverse power-law dispersal kernel outperformed those based on the Gaussian dispersal kernel, indicating that pollen dispersal kernels are fat tailed. Pine and birch have the highest pollen productivities. Pollen productivity and dispersal estimates are generally consistent with previous understanding from modern data sets, although source area estimates are larger. Tests of model predictions demonstrate the ability of STEPPS to predict regional compositional patterns.

  15. The Black Cholera Comes to the Central Valley of America in the 19th Century - 1832, 1849, and Later

    PubMed Central

    Daly, Walter J.

    2008-01-01

    In mid-19th Century, cholera was epidemic throughout the world. Small towns of the American Midwest were not spared. The disease was blamed on miasmas arising from local causes, so flight from affected localities were logical and common. Flight, added to mortality, caused virtual depopulation of many small towns. Drinking water was drawn from rivers or shallow wells, often near seeping cesspools. Local merchants tried unsuccessfully to calm panic by suppressing information. Cholera was not good for business. Business was depressed. Organized religion thrived. National and state days of prayer were appointed to appease an angry God. During these frightening times, the people learned nothing about the infectiousness of cholera or about its prevention through sanitation. Their experiences tended to reinforce their belief in miasmas or divine retribution. The great epidemics of mankind describe human behavior in times of unavoidable and incurable crisis. Nineteenth Century cholera experiences illustrate a people's reaction to catastrophic disease, which they believed was incurable and unpreventable. PMID:18596846

  16. Quantifying pollen-vegetation relationships to reconstruct ancient forests using 19th-century forest composition and pollen data

    NASA Astrophysics Data System (ADS)

    Dawson, Andria; Paciorek, Christopher J.; McLachlan, Jason S.; Goring, Simon; Williams, John W.; Jackson, Stephen T.

    2016-04-01

    Mitigation of climate change and adaptation to its effects relies partly on how effectively land-atmosphere interactions can be quantified. Quantifying composition of past forest ecosystems can help understand processes governing forest dynamics in a changing world. Fossil pollen data provide information about past forest composition, but rigorous interpretation requires development of pollen-vegetation models (PVMs) that account for interspecific differences in pollen production and dispersal. Widespread and intensified land-use over the 19th and 20th centuries may have altered pollen-vegetation relationships. Here we use STEPPS, a Bayesian hierarchical spatial PVM, to estimate key process parameters and associated uncertainties in the pollen-vegetation relationship. We apply alternate dispersal kernels, and calibrate STEPPS using a newly developed Euro-American settlement-era calibration data set constructed from Public Land Survey data and fossil pollen samples matched to the settlement-era using expert elicitation. Models based on the inverse power-law dispersal kernel outperformed those based on the Gaussian dispersal kernel, indicating that pollen dispersal kernels are fat tailed. Pine and birch have the highest pollen productivities. Pollen productivity and dispersal estimates are generally consistent with previous understanding from modern data sets, although source area estimates are larger. Tests of model predictions demonstrate the ability of STEPPS to predict regional compositional patterns.

  17. Theodor Waitz's theory of feelings and the rise of affective sciences in the mid-19th century.

    PubMed

    Romand, David

    2015-11-01

    The German psychologist Theodor Waitz (1821-1864) was an important theorist of affectivity in the mid-19th century. This article aims to revisit Waitz's contribution to affective psychology at a crucial moment of its history. First, I elaborate the context in which Waitz's ideas were carried out by showing how affective sciences emerged as an autonomous field of investigation between about 1770 and 1910. Second, I discuss the principles of Waitz's model of affectivity and their contextual significance. Third, I deal with the first major category of affective states identified by Waitz, namely, "formal feelings," which are supposed to be involved in the appraisal of the relational properties between representations. Fourth, I investigate "qualitative feelings," the second major category of affective states identified by Waitz, which refer to affective processes that relate to specific representational contents, namely, intellectual, aesthetic, and moral feelings. In conclusion, I emphasize the genealogical link between Waitz's pioneering research on musical feelings and current research on emotion and expectation in music.

  18. [The midwives of Guadalajara (México) in the 19th century, the plundering of their art].

    PubMed

    Díaz Robles, Laura Catalina; Oropeza Sandoval, Luciano

    2007-01-01

    This study examines the social devaluation of the knowledge and practice used by midwives in their work. The research is limited to historical events that took place during the 19th century in the city of Guadalajara, capital of the state of Jalisco in Mexico. The study shows how the displacement and subordination of these women were associated with the higher social status of physicians. Supported by advances in medicine and by the authority derived from the knowledge acquired through formal educational institutions, doctors started to undermine the value of empirical knowledge and subordinate it to the knowledge that came from these advances. It is shown how doctors detract from and subordinated the midwife to the scientific-employment field of medicine by using a discourse that degraded empirical knowledge and by institutionalizing training courses that tended to ignore the practical know-how of these women and replace it with knowledge derived from scientific medicine. The study is based on information from archives and scientific journals of the time: Archiva Fondos Especiales de la Biblioteca Pública de Jalisco, Archivo Histórico de Jalisco, Archivo Histórico de la Universidad de Guadalajara, Archivo Municipal de Guadalajara and Revista Médica.

  19. Geophysical survey applied to underwater archaeology: a 19th century town submerged in Tequesquitengo Lake, Morelos, México

    NASA Astrophysics Data System (ADS)

    Galindo Dominguez, R. E.; Bandy, W. L.

    2010-12-01

    In August 2009, we conducted an underwater geophysical survey with archaeological objectives at the Tequesquitengo Lake, in Morelos, Mexico. This survey was supervised by researchers from the UNAM’s Institute of Geophysics. The main objectives were to locate and delimitate the archaeological site of a submerged town which lies at the bottom of the lake since the mid 19th century by using geophysical survey techniques. A small size vessel used for our survey was provided by the local Harbour Master, onboard which we mounted a differential GPS unit, navigation system, a dual 38 kHz/200 Khz echosounder and 200 kHz sidescan sonar system, and a marine proton magnetometer, to accomplish our objectives. A bathymetric survey of the site was carried out. And using magnetometry the archaeological site was delimitated. We acquired various sonar images of the higher structures of a church. The magnetic maps showed us some anomalies, which could be an indication of the remains of the submerged town. Additional future surveys, backed up by more research dives could definitely help us in obtaining a broad insight into the history and cultural diversity of this site.

  20. The "Abyssal Society". François-Alphonse Forel and the Case of Deep Fauna in Late 19th Century.

    PubMed

    Campanella, Sara

    2016-01-01

    Ichthyological investigations and technological advancements, such as the laying of submarine telegraph cables, promoted new dredging methods in the second half of the 19th century. In contrast to the idea of a lifeless deep ocean (Edward Forbes' azoic hypothesis), the discovery of deep water fauna and the challenge of defining its systematics opened up new theoretical perspectives. In this frame, which was already marked by the impact of Darwin's theory, naturalistic surveys in freshwater environments in western Switzerland intertwined with those of oceanographic expeditions. The study of the fauna in the depths of subalpine lakes by the Swiss savant François-Alphonse Forel was one of the most striking examples of this turning point, because the relatively recently evolution of its freshwater fauna allowed him to investigate: (a) the role of isolation, (b) the progressive differentiation of species from a common ancestor, and (c) the constitution of a species-specific category in form transition, from a genealogical viewpoint to an ecological one.

  1. [Psychophysical parallelism. On a discursive figure in the field of scientific changes in the late 19th century].

    PubMed

    Wegener, Mai

    2009-01-01

    The article traces the rise and fall of "psychophysical parallelism" - which was the most advanced scientific formulation of the mind / body relationship in the second half of the 19th century - through an interdisciplinary and broad geographical spectrum. It sheds light on the extremely different positions that rallied round this discursive figure, ranging from Fechner, Hering, Mach, Wundt, Bain, Hughlings Jackson, and Taine to Freud and Saussure. The article develops the thesis that the psychophysical parallelism functioned as a 'hot zone' within and a symptom of the changes in the order of sciences at that time. Against that background, the criticism of the psychophysical parallelism which became prominent around 1900 (Stumpf, Busse, Bergson, Mauthner et. al.) indicates the cooling of this 'hot zone' and the establishment of a new order within the scientific disciplines. The article pays particular attention to the position of this figure in contemporaneous language theories. Its basic assumption is that the relationship between the body and the psyche is itself constituted by language.

  2. "Winged sponges": houseflies as carriers of typhoid fever in 19th- and early 20th-century military camps.

    PubMed

    Cirillo, Vincent J

    2006-01-01

    Typhoid fever was the scourge of 19th- and early 20th-century armies. During the Spanish-American War (1898) and the Anglo-Boer War (1899- 1902), typhoid killed more soldiers than enemy bullets. Walter Reed and his coworkers investigated the cause of the typhoid epidemics in the U.S. Army camps and concluded that, next to human contact, the housefly (Musca domestica) was the most active agent in the spread of the disease. British medical officers in South Africa, facing even worse typhoid epidemics, reached the same conclusion. The experiences of the American and British armies finally convinced the medical profession and public health authorities that these insects conveyed typhoid. The housefly was now seen as a health menace. Military and civilian sanitarians waged fly-eradication campaigns that prevented the housefly's access to breeding places (especially human excrement), and that protected food and drink from contamination. Currently, M. domestica is recognized as the mechanical vector of a wide variety of viral, bacterial, and protozoal pathogens. Fly control is still an important public health measure in the 21st century, especially in developing countries.

  3. Teaching of Psychology: Ideas and Innovations. Proceedings of the Annual Conference on Undergraduate Teaching of Psychology (19th, Monticello, New York, April 6-8, 2005)

    ERIC Educational Resources Information Center

    Zaromatidis, Katherine, Ed.; Oswald, Patricia A., Ed.; Levine, Judith R., Ed.; Indenbaum, Gene, Ed.

    2005-01-01

    The 19th Annual Conference on Undergraduate Teaching of Psychology was held on April 6-8, 2005 at Kutsher's Country Club in Monticello, New York. The conference was sponsored by the Psychology Department of the State University of New York at Farmingdale. The conference featured two keynote speakers--Dr. James Naire, sponsored by Wadsworth…

  4. American Journalism Historians Association Annual Convention (London, Ontario, Canada, October 3-5, 1996). Part I: Selected Papers Covering the Colonial Period through the 19th Century.

    ERIC Educational Resources Information Center

    American Journalism Historians' Association.

    The 16 papers presented in this collection all deal with journalism and journalists from colonial America through the 19th century. The papers and their authors are: "Fighting for a Continent: Newspaper Coverage of the English and French War for Control of North America, 1754-1760" (David A. Copeland); "A Romance with 'Local'…

  5. Development of Formal Agricultural Education in Canada (Based on the Analysis of Scientific Periodicals of the 19th-Early 20th Centuries)

    ERIC Educational Resources Information Center

    Havrylenko, Kateryna

    2016-01-01

    The article states that one of the world leaders in agricultural sector training is Canada, which has gained a great scientific and practical experience. The paper examines the role of periodicals of the 19th-early 20th centuries, preserved in the Canadian book funds for the establishment and development of formal agricultural education of this…

  6. Atomic Pioneers, Book 2, From the Mid-19th to the Early 20th Century. A World of the Atom Series Booklet.

    ERIC Educational Resources Information Center

    Hiebert, Ray; Hiebert, Roselyn

    This booklet is concerned with the last half of the 19th and the beginning of the 20th century when a great surge of knowledge vital to atomic science took place, as illustrated by work by Faraday, Mendeleev, Roentgen, Becquerel and the Curies. Each succeeding discovery brought atomic science closer to the great breakthrough that marked the close…

  7. Library Automation as a Source of Management Information. Papers presented at the Clinic on Library Applications of Data Processing (19th, Urbana, IL, April 25-28, 1982).

    ERIC Educational Resources Information Center

    Lancaster, F. Wilfrid, Ed.

    Papers presented at the 19th Clinic on Library Applications of Data Processing represent a great variety, ranging from a tutorial on management information and decision support systems, through more philosophical discussions of the value of computer-derived information in library management, to studies of the use of automated systems as sources of…

  8. Cultural and Educational Dimensions Reflected in Books Popularizing Scientific Knowledge--A Case Study: "The Sky", a 19th Century Book Popularizing Astronomy

    ERIC Educational Resources Information Center

    Halkia, Krystallia; Botouropoulou, Iphigenia

    2005-01-01

    The present work is concerned with one of the most successful books popularizing astronomy of the last half of the 19th century, published in France under the title "L' Astronomie Populaire". The book was translated into Greek and was the first book, out of 100, which was published in order to be a part of a popular library meant to educate the…

  9. National Gender Policy in Public Education in the Russian Empire in the Latter Half of the 19th-Early 20th Centuries

    ERIC Educational Resources Information Center

    Saifullova, Razilia Rauilovna; Maslova, Inga Vladimirovna; Krapotkina, Irina Evgenevna; Kaviev, Airat Farkhatovich; Nasyrova, Liliya Gabdelvalievna

    2016-01-01

    This article presents the national gender policy in public education in the Russian Empire in the latter half of the 19th-early 20th centuries. In the course of work the authors have used special historical research methods enabling to hammer out the facts and to approach historical sources from a critical standpoint. The comparative method…

  10. History at the Mercy of Politicians and Ideologies: Germany, England, and the Netherlands in the 19th and 20th Centuries

    ERIC Educational Resources Information Center

    Wilschut, Arie H. J.

    2010-01-01

    The paper analyses and compares developments in history teaching in Germany, England, and the Netherlands in the 19th and 20th centuries. The development of history teaching in the three countries shows striking similarities. National politics have always used history education for purposes which did not necessarily tally with distanced critical…

  11. The Rise and Fall of Science Education: A Content Analysis of Science in Elementary Reading Textbooks of the 19th Century

    ERIC Educational Resources Information Center

    Rillero, Peter

    2010-01-01

    In the 19th century the textbook dominated the curriculum and methods of instruction. The most important textbook was the textbook of reading known as the reader. In the early 1800s science was not established as a separate primary grade subject. The science students encountered in these reading textbooks may have been their only formal science…

  12. The Humanistic Approach to Upbringing and Education in the Creative Legacy of the Ukrainian Pedagogues of the Second Half of the 19th Century

    ERIC Educational Resources Information Center

    Anosov, Ivan Pavlovych; Elkin, Mark Veniaminovych; Golovkova, Marina Mykhaylivna; Korobchenko, Angelina Anatoliivna; Oksa, Mykola Mykolayovych

    2015-01-01

    The article is dedicated to the study of the humanistic approach to upbringing and education in the creative legacy of the Ukrainian pedagogues of the second half of the 19th century. Through the analysis of S. Myropolskiy's and Kh. Alchevska's pedagogical legacy, a world outlook position of scholars concerning humanisation of the educational…

  13. Ideological Themes in Movements for Child Labor Reform and in Images of Children in Literature in 19th Century England and America.

    ERIC Educational Resources Information Center

    Kirschner, Suzanne

    This paper explores ideological factors that influenced child labor reform and the image of the child as depicted in romantic and sentimental literature of 19th century England and the United States. In both countries the image of the child and the view of the relative roles of the parent and the state in bearing responsibility for children…

  14. Technology in Mathematics Education: Proceedings of the 19th Annual Conference of the Mathematics Education Research Group of Australasia (MERGA) (Melbourne, Victoria, Australia, June 30-July 3, 1996).

    ERIC Educational Resources Information Center

    Clarkson, Philip C., Ed.

    This document contains papers presented at the 19th annual conference of the Mathematics Education Research Group of Australasia. Topics of the presentations include learning research, mathematical representations, problem solving, strategic learning behaviors, algebraic thinking and learning environments, teaching and learning of algebra,…

  15. (Re)Constructions of Etymology of the Term "Electricity" in French German and Modern Greek Textbooks of Physics of 18th-19th Centuries

    ERIC Educational Resources Information Center

    Patsopoulos, Dimitrios

    2005-01-01

    The different and contrasting versions of the etymology of the term "electricity" in Modern Greek textbooks of Physics of the 18th and 19th century, which are influenced by French and German textbooks, are not mere (re)constructions that serve the didactic purposes and objectives of their authors. They are (in)directly related to the social and…

  16. New early instrumental series since the beginning of the 19th century in eastern Iberia (Valencia, Spain)

    NASA Astrophysics Data System (ADS)

    Sanchez-Lorenzo, Arturo; Barriendos, Mariano; Guinaldo, Elena; Lopez-Bustins, Joan A.

    2010-05-01

    Early instrumental series are the main source for climate information in the 18th and the first part of the 19th century, which is when systematic meteorological observations started in most national meteorological services. The first continuous series in Spain starts in 1780 in Barcelona due to meteorological observations made by the medical doctor Francisco Salvá Campillo. Moreover, only two other series have been recovered at the present in Spain: Madrid and Cádiz/San Fernando. Until present, in Spain the major part of the meteorological observations detected in early instrumental periods were made by medical doctors, who started to pay attention to the environmental factors influencing population health under the Hippocrates oath, although also there are military institutions and academic university staff (e.g. physicists, mathematicians, etc.). Due to the high spatial and temporal climate variability in the Iberian Peninsula, it is important to recover and digitize more climatic series, and this is one of the main goals of the Salvá-Sinobas project (http://salva-sinobas.uvigo.es/) funded by the Spanish Ministry of Environment, and Rural and Marine Affairs for the 2009-2011 period. The first new series with systematic observations was detected in the city of Valencia, in the eastern façade of the Iberian Peninsula. The meteorological observations were daily published in the newspapers Diario de Valencia (1804-1834) and Diario Mercantil de Valencia (1837-1863) until official meteorological observations started in 1858 at the University of Valencia. Each day 3-daily observations (morning, midday, afternoon) were published with five climatic variables: temperature, air pressure, humidity, wind direction and the sky state. Only during the 1804-1808 period daily rainfall data is available. We checked the observer comments published in the newspapers to obtain metadata about the instruments and meteorological station information. Unfortunately, temperature data

  17. Two Intense Decades of 19th Century Whaling Precipitated Rapid Decline of Right Whales around New Zealand and East Australia

    PubMed Central

    Carroll, Emma L.; Jackson, Jennifer A.; Paton, David; Smith, Tim D.

    2014-01-01

    Right whales (Eubalaena spp.) were the focus of worldwide whaling activities from the 16th to the 20th century. During the first part of the 19th century, the southern right whale (E. australis) was heavily exploited on whaling grounds around New Zealand (NZ) and east Australia (EA). Here we build upon previous estimates of the total catch of NZ and EA right whales by improving and combining estimates from four different fisheries. Two fisheries have previously been considered: shore-based whaling in bays and ship-based whaling offshore. These were both improved by comparison with primary sources and the American offshore whaling catch record was improved by using a sample of logbooks to produce a more accurate catch record in terms of location and species composition. Two fisheries had not been previously integrated into the NZ and EA catch series: ship-based whaling in bays and whaling in the 20th century. To investigate the previously unaddressed problem of offshore whalers operating in bays, we identified a subset of vessels likely to be operating in bays and read available extant logbooks. This allowed us to estimate the total likely catch from bay-whaling by offshore whalers from the number of vessels seasons and whales killed per season: it ranged from 2,989 to 4,652 whales. The revised total estimate of 53,000 to 58,000 southern right whales killed is a considerable increase on the previous estimate of 26,000, partly because it applies fishery-specific estimates of struck and loss rates. Over 80% of kills were taken between 1830 and 1849, indicating a brief and intensive fishery that resulted in the commercial extinction of southern right whales in NZ and EA in just two decades. This conforms to the global trend of increasingly intense and destructive southern right whale fisheries over time. PMID:24690918

  18. 19th-20th century rainfall patterns reconstructed from sediment provenance in a Santa Barbara Basin box core

    NASA Astrophysics Data System (ADS)

    Napier, T.; Hendy, I. L.; Schimmelmann, A.

    2013-12-01

    Rainfall patterns in Southern California directly affect the availability of water resources and induce hazards in this highly populated and water stressed region. Extreme weather consists of heavy rainfall events in winter associated with atmospheric rivers, and drought conditions when winter rains do not arrive. Water availability has a significant societal impact in Southern California. Here we reconstruct 19th-20th century precipitation history of river catchments draining into Santa Barbara Basin (SBB) through a combination of high-resolution elemental and mineralogical analyses. The deep center of the SBB features suboxic bottom waters and high sedimentation rates resulting in minimal bioturbation of annual sedimentation, which enables high-resolution paleoclimate research. Scanning XRF analysis at a 200 μm resolution of box core SPR0901-04BC from SBB was used to determine annual changes in sediment composition. Samples at 1 cm resolution from the same box core were analyzed for a more extensive suite of elements by ICP-MS, while mineralogy in each sample was determined from whole rock and clay fraction (<2 μm) analysis using X-ray defraction. Elements associated with siliciclastic sediment increase in relative abundance during wet years when significant river runoff events (floods) occurred. The relative proportions of these elements differ between flood events, possibly reflecting differences in temporal and/or spatial rainfall patterns that vary the response of each river catchment draining into SBB. Watershed sediment from the Santa Ynez Mountain streams and Ventura and Santa Clara River catchments derives mostly from Cenozoic sedimentary units, except the Santa Clara River catchment, which contains metamorphic and igneous units. As river runoff is responsible for a significant portion of the terrigenous input into SBB, and is primarily the result of precipitation events, characteristic mineralogy and elemental signatures are a direct recorder of

  19. Hydrometeorological extremes reconstructed from documentary evidence for the Jihlava region in the 17th-19th centuries

    NASA Astrophysics Data System (ADS)

    Dolak, Lukas; Brazdil, Rudolf; Chroma, Katerina; Valasek, Hubert; Belinova, Monika; Reznickova, Ladislava

    2016-04-01

    Different documentary evidence (taxation records, chronicles, insurance reports etc.) is used for reconstruction of hydrometeorological extremes (HMEs) in the Jihlava region (central part of the recent Czech Republic) in the 17th-19th centuries. The aim of the study is description of the system of tax alleviation in Moravia, presentation of utilization of early fire and hail damage insurance claims and application of the new methodological approaches for the analysis of HMEs impacts. During the period studied more than 400 HMEs were analysed for the 16 estates (past basic economic units). Late frost on 16 May 1662 on the Nove Mesto na Morave estate, which destroyed whole cereals and caused damage in the forests, is the first recorded extreme event. Downpours causing flash floods and hailstorms are the most frequently recorded natural disasters. Moreover, floods, droughts, windstorms, blizzards, late frosts and lightning strikes starting fires caused enormous damage as well. The impacts of HMEs are classified into three categories: impacts on agricultural production, material property and the socio-economic impacts. Natural disasters became the reasons of losses of human lives, property, supplies and farming equipment. HMEs caused damage to fields and meadows, depletion of livestock and triggered the secondary consequences as lack of seeds and finance, high prices, indebtedness, poverty and deterioration in field fertility. The results are discussed with respect to uncertainties associated with documentary evidences and their spatiotemporal distribution. Archival records, preserved in the Moravian Land Archives in Brno and other district archives, create a unique source of data contributing to the better understanding of extreme events and their impacts.

  20. Achievements of Polish doctors in gastrodiaphanoscopy at the turn of the 19(th) and 20(th) centuries.

    PubMed

    Kierzek, Andrzej; Paprocka-Borowicz, Małgorzata; Pozowski, Andrzej; Kuciel-Lewandowska, Jadwiga

    2013-01-01

    Diaphanoscopy/transillumination, the method of shining a bright light through tissues, was devised in the mid-19(th) century and developed after the invention of the light bulb by T.A. Edison. Benjamin Milliot was the first to examine the stomach by means of an incandescent platinum wire. The experiments conducted by Max Einhorn using a device consisting of a Nelaton catheter with an inserted light bulb, were valuable. In Poland the method of gastrodiaphanoscopy was popularized by Teodor Heryng, Mikołaj Rejchman and by Warsaw doctors. They used a diaphanoscope consisting of a gutta-percha probe distally equipped with a metal attachment with a light bulb hidden in it and with a so-called cooling device. The examination would usually be conducted in the standing position after the stomach had been filled with water. Light patches corresponding to the stomach's lower and side boundaries would be obtained. Rejchman's observation, that such a contractile and flexible organ as the stomach, changing its volume and position, is bound to change its light image, was correct. Heryng's and Rejchman's research inspired the foreign researchers Renvier, Leopold Kuttner and John Jacobson. Extensive research was subsequently conducted by C.A. Meltzing and Wilhelm Schwartz. Diaphanoscopy would also be performed by Walery Jaworski, the pioneer of gastrology. He was particularly interested in transillumination of the stomach, peritoneum and omentum tumours. Eugeniusz Kozierowski, a practicing physician from Gorlice, diagnosed neoplastic pylorostenosisusing this method. Gastrodiaphanoscopy is a historical method, now of no value against gastroendoscopy and the state-of-the-art methods of image diagnostics.

  1. Nelson's wound: treatment of spinal cord injury in 19th and early 20th century military conflicts.

    PubMed

    Hanigan, William C; Sloffer, Chris

    2004-01-15

    During the first half of the 19th century, warfare did not provide a background for a systematic analysis of spinal cord injury (SCI). Medical officers participating in the Peninsular and Crimean Wars emphasized the dismal prognosis of this injury, although authors of sketchy civil reports persuaded a few surgeons to operate on closed fractures. The American Medical and Surgical History of the War of the Rebellion was the first text to provide summary of results in 642 cases of gunshot wounds of the spine. The low incidence of this injury (0.26%) and the high mortality rate (55%) discouraged the use of surgery in these cases. Improvements in diagnoses and the introduction of x-ray studies in the latter half of the century enabled Sir G. H. Makins, during the Boer War, to recommend delayed intervention to remove bone or bullet fragments in incomplete injuries. The civil experiences of Elsberg and Frazier in the early 20th century promoted a meticulous approach to treatments, whereas efficient transport of injured soldiers during World War I increased the numbers of survivors. Open large wounds or cerebrospinal fluid leakage, signs of cord compression in recovering patients, delayed clinical deterioration, or intractable pain required surgical exploration. Wartime recommendations for urological and skin care prevented sepsis, and burgeoning pension systems provided specialized longterm rehabilitation. By the Armistice, the effective surgical treatment and postoperative care that had developed through decades of interaction between civil and military medicine helped reduce incidences of morbidity and dispel the hopelessness surrounding the combatant with an SCI.

  2. Achievements of Polish doctors in gastrodiaphanoscopy at the turn of the 19th and 20th centuries

    PubMed Central

    Paprocka-Borowicz, Małgorzata; Pozowski, Andrzej; Kuciel-Lewandowska, Jadwiga

    2013-01-01

    Diaphanoscopy/transillumination, the method of shining a bright light through tissues, was devised in the mid-19th century and developed after the invention of the light bulb by T.A. Edison. Benjamin Milliot was the first to examine the stomach by means of an incandescent platinum wire. The experiments conducted by Max Einhorn using a device consisting of a Nelaton catheter with an inserted light bulb, were valuable. In Poland the method of gastrodiaphanoscopy was popularized by Teodor Heryng, Mikołaj Rejchman and by Warsaw doctors. They used a diaphanoscope consisting of a gutta-percha probe distally equipped with a metal attachment with a light bulb hidden in it and with a so-called cooling device. The examination would usually be conducted in the standing position after the stomach had been filled with water. Light patches corresponding to the stomach’s lower and side boundaries would be obtained. Rejchman’s observation, that such a contractile and flexible organ as the stomach, changing its volume and position, is bound to change its light image, was correct. Heryng’s and Rejchman’s research inspired the foreign researchers Renvier, Leopold Kuttner and John Jacobson. Extensive research was subsequently conducted by C.A. Meltzing and Wilhelm Schwartz. Diaphanoscopy would also be performed by Walery Jaworski, the pioneer of gastrology. He was particularly interested in transillumination of the stomach, peritoneum and omentum tumours. Eugeniusz Kozierowski, a practicing physician from Gorlice, diagnosed neoplastic pylorostenosisusing this method. Gastrodiaphanoscopy is a historical method, now of no value against gastroendoscopy and the state-of-the-art methods of image diagnostics. PMID:24868282

  3. A chaotic model for the plague epidemic that has occurred in Bombay at the end of the 19th century

    NASA Astrophysics Data System (ADS)

    Mangiarotti, Sylvain

    2015-04-01

    The plague epidemic that has occurred in Bombay at the end of the 19th century was detected in 1896. One year before, an Advisory Committee had been appointed by the Secretary of State for India, the Royal Society, and the Lister Institute. This Committee made numerous investigations and gathered a large panel of data including the number of people attacked and died from the plague, records of rat and flea populations, as well as meteorological records of temperature and humidity [1]. The global modeling technique [2] aims to obtain low dimensional models able to simulate the observed cycles from time series. As far as we know, this technique has been tried only to one case of epidemiological analysis (the whooping cough infection) based on a discrete formulation [3]. In the present work, the continuous time formulation of this technique is used to analyze the time evolution of the plague epidemic from this data set. One low dimensional model (three variables) is obtained exhibiting a limit cycle of period-5. A chaotic behavior could be derived from this model by tuning the model parameters. It provides a strong argument for a dynamical behavior that can be approximated by low dimensional deterministic equations. This model also provides an empirical argument for chaos in epidemics. [1] Verjbitski D. T., Bannerman W. B. & Kápadiâ R. T., 1908. Reports on Plague Investigations in India (May,1908), The Journal of Hygiene, 8(2), 161 -308. [2] Mangiarotti S., Coudret R., Drapeau L. & Jarlan L., 2012. Polynomial search and Global modelling: two algorithms for modeling chaos. Physical Review E, 86(4), 046205. [3] Boudjema G. & Cazelles B., 2003. Extraction of nonlinear dynamics from short and noisy time series. Chaos, Solitons and Fractals, 12, 2051-2069.

  4. Using sunshine duration data to reconstruct total solar radiation time series since the late 19th century, for Athens area

    NASA Astrophysics Data System (ADS)

    Founda, Dimitra; Kazadzis, Stelios; Pierros, Fragiskos; Mihalopoulos, Nikolaos

    2015-04-01

    Due to the scarcity of surface solar radiation measurements and the lack of long term time series of this variable, sunshine duration (SDu) has been widely considered as a useful proxy for surface total solar radiation (TSR) reaching the earth. Numerous relationships between SDu and TSR have been proposed which vary between sites, as a result of the dependence of the two variables from climatic and astronomical components. At the National Observatory of Athens (NOA), measurements of sunshine duration and surface total solar radiation have been conducted continuously since 1897 and 1953 respectively. These are the longest uninterrupted time series of SDu and TSR in the country. The ability of SDu observations at NOA to serve as a proxy for the estimation of TSR and the detection of its interannual and multi decadal variability is examined in the study. Using the respective time series we have retrieved the relationship between SDu and TSR on a monthly, seasonal and annual basis. To test the retrieved functions we have derived them for the period 1985-2013 and tested them for the period 1953-1984, where synchronous SDu and TSR measurements are available. A strong linear relationship between the time series of monthly SDU and TSR was found. The two series were highly correlated (correlation coefficient > 0.95, p<0.001). On a seasonal basis, stronger correlation between SDu and TSR was detected in winter, autumn and spring, when SDu and TSR exhibit larger variability due to cloudiness. The correlation coefficient was lower in summer, when almost clear sky conditions prevail in Athens. The results showed that SDu observations in Athens can successfully provide quantitative information on shortwave solar radiation, particularly under all-sky conditions. The calculated functions can be used for the reconstruction of TSR back to the late 19th century. This unique 115-yrs SDu and TSR retrieved datasets can provide valuable and unknown information of TSR variability over the

  5. Two intense decades of 19th century whaling precipitated rapid decline of right whales around New Zealand and East Australia.

    PubMed

    Carroll, Emma L; Jackson, Jennifer A; Paton, David; Smith, Tim D

    2014-01-01

    Right whales (Eubalaena spp.) were the focus of worldwide whaling activities from the 16th to the 20th century. During the first part of the 19th century, the southern right whale (E. australis) was heavily exploited on whaling grounds around New Zealand (NZ) and east Australia (EA). Here we build upon previous estimates of the total catch of NZ and EA right whales by improving and combining estimates from four different fisheries. Two fisheries have previously been considered: shore-based whaling in bays and ship-based whaling offshore. These were both improved by comparison with primary sources and the American offshore whaling catch record was improved by using a sample of logbooks to produce a more accurate catch record in terms of location and species composition. Two fisheries had not been previously integrated into the NZ and EA catch series: ship-based whaling in bays and whaling in the 20th century. To investigate the previously unaddressed problem of offshore whalers operating in bays, we identified a subset of vessels likely to be operating in bays and read available extant logbooks. This allowed us to estimate the total likely catch from bay-whaling by offshore whalers from the number of vessels seasons and whales killed per season: it ranged from 2,989 to 4,652 whales. The revised total estimate of 53,000 to 58,000 southern right whales killed is a considerable increase on the previous estimate of 26,000, partly because it applies fishery-specific estimates of struck and loss rates. Over 80% of kills were taken between 1830 and 1849, indicating a brief and intensive fishery that resulted in the commercial extinction of southern right whales in NZ and EA in just two decades. This conforms to the global trend of increasingly intense and destructive southern right whale fisheries over time.

  6. Micromechanical models for textile composites

    NASA Technical Reports Server (NTRS)

    Sankar, Bhavani V.; Marrey, Ramesh V.

    1995-01-01

    Numerical and analytical micromechanical models are presented to predict the thermoelastic behavior of a textile composite. In the numerical model, the unit-cell is discretized with finite elements, and periodic boundary conditions are imposed between opposite faces of the unit-cell. For a thin textile composite, stress gradients effects through the thickness are demonstrated. The consequent difference in the stiffness and strength behavior of thick and thin composites are discussed. The numerical model is implemented to predict 3-D thermo-elastic constants for a thick textile composite, and the plate thermo-mechanical properties for a thin textile composite. The numerical model is extended to compute the thermal residual microstresses due to processing to predict the composite failure envelopes. An analytical model - Selective Averaging Method (SAM) - is proposed, which is based on a judicious combination of stiffness and compliance averaging to estimate the 3-D elastic constants. Both the models are tested and verified for several examples by comparing the stiffness properties with elasticity solutions and available results.

  7. Qubit thermometry for micromechanical resonators

    SciTech Connect

    Brunelli, Matteo; Olivares, Stefano; Paris, Matteo G. A.

    2011-09-15

    We address estimation of temperature for a micromechanical oscillator lying arbitrarily close to its quantum ground state. Motivated by recent experiments, we assume that the oscillator is coupled to a probe qubit via Jaynes-Cummings interaction and that the estimation of its effective temperature is achieved via quantum-limited measurements on the qubit. We first consider the ideal unitary evolution in a noiseless environment and then take into account the noise due to nondissipative decoherence. We exploit local quantum estimation theory to assess and optimize the precision of estimation procedures based on the measurement of qubit population and to compare their performances with the ultimate limit posed by quantum mechanics. In particular, we evaluate the Fisher information (FI) for population measurement, maximize its value over the possible qubit preparations and interaction times, and compare its behavior with that of the quantum Fisher information (QFI). We found that the FI for population measurement is equal to the QFI, i.e., population measurement is optimal, for a suitable initial preparation of the qubit and a predictable interaction time. The same configuration also corresponds to the maximum of the QFI itself. Our results indicate that the achievement of the ultimate bound to precision allowed by quantum mechanics is in the capabilities of the current technology.

  8. Frequency stabilization in nonlinear micromechanical oscillators

    NASA Astrophysics Data System (ADS)

    Antonio, Dario; Zanette, Damián H.; López, Daniel

    2012-05-01

    Mechanical oscillators are present in almost every electronic device. They mainly consist of a resonating element providing an oscillating output with a specific frequency. Their ability to maintain a determined frequency in a specified period of time is the most important parameter limiting their implementation. Historically, quartz crystals have almost exclusively been used as the resonating element, but micromechanical resonators are increasingly being considered to replace them. These resonators are easier to miniaturize and allow for monolithic integration with electronics. However, as their dimensions shrink to the microscale, most mechanical resonators exhibit nonlinearities that considerably degrade the frequency stability of the oscillator. Here we demonstrate that, by coupling two different vibrational modes through an internal resonance, it is possible to stabilize the oscillation frequency of nonlinear self-sustaining micromechanical resonators. Our findings provide a new strategy for engineering low-frequency noise oscillators capitalizing on the intrinsic nonlinear phenomena of micromechanical resonators.

  9. PREFACE: The 19th European Sectional Conference on Atomic and Molecular Physics of Ionized Gases Preface: The 19th European Sectional Conference on Atomic and Molecular Physics of Ionized Gases

    NASA Astrophysics Data System (ADS)

    Gordillo-Vazquez, F. J.

    2009-07-01

    The 19th Europhysics Sectional Conference on the Atomic and Molecular Physics of Ionized Gases (ESCAMPIG-2008) took place in Granada (Spain) from 15 to 19 July 2008. The conference was mainly organized by the Spanish National Research Council (CSIC), with the collaboration and support of the University of Córdoba (UCO) and the Research Center for Energy, Environment and Technology (CIEMAT). It is already 35 years since the first ESCAMPIG in 1973. The first editions of ESCAMPIG were in consecutive years (1973 and 1974) but later on it became a biennial conference of the European Physical Society (EPS) initially focusing on the collisional and radiative atomic and molecular processes in low temperature plasmas. The successive ESCAMPIGs took place in Bratislava in 1976 (3rd), Essen in 1978 (4th), Dubrovnik in 1980 (5th) and so on until the last one organized in Granada in 2008 (19th), the first ESCAMPIG in Spain. A number of changes have taken place in the Granada edition of ESCAMPIG. First, the previous six topics that have remained unchanged for almost two decades (since 1990) have now been updated to become twelve new topics which, in the opinion of the International Scientific Committee (ISC), will enhance the opportunity for discussions and communication of new findings and developments in the field of low temperature plasmas. The new list of topics for ESCAMPIG is: • Atomic and molecular processes in plasmas • Transport phenomena, particle velocity distribution function • Physical basis of plasma chemistry • Plasma surface interaction (boundary layers, sheath, surface processes) • Plasma diagnostics • Plasma and dicharges theory and simulation • Self-organization in plasmas, dusty plasmas • Upper atmospheric plasmas and space plasmas • Low pressure plasma sources • High pressure plasma sources • Plasmas and gas flows • Laser produced plasmas Secondly, a new prize has been created, the `William Crookes' prize in Plasma Physics to be

  10. Analogy among microfluidics, micromechanics, and microelectronics.

    PubMed

    Li, Sheng-Shian; Cheng, Chao-Min

    2013-10-07

    We wish to illuminate the analogous link between microfluidic-based devices, and the already established pairing of micromechanics and microelectronics to create a triangular/three-way scientific relationship as a means of interlinking familial disciplines and accomplishing two primary goals: (1) to facilitate the modeling of multidisciplinary domains; and, (2) to enable us to co-simulate the entire system within a compact circuit simulator (e.g., Cadence or SPICE). A microfluidic channel-like structure embedded in a micro-electro-mechanical resonator via our proposed CMOS-MEMS technology is used to illustrate the connections among microfluidics, micromechanics, and microelectronics.

  11. Policy Commercializing Nonprofits in Health: The History of a Paradox From the 19th Century to the ACA

    PubMed Central

    FOX, DANIEL M

    2015-01-01

    growth and commercialization of nonprofits in the health sector since the late 19th century remains influential in health policy, especially for the allocation of resources. However, aspects of the implementation of the ACA may constrain some of the effects of the paradox. PMID:25752354

  12. Analysis of Climatic Variations based on the Instrumental Meteorological Records at Dejima, Japan since 19th century.

    NASA Astrophysics Data System (ADS)

    Zaiki, M.

    2001-12-01

    When we make a study of past climatic variations, it would be preferable to get as long instrumental records as possible. In Japan, however, the earliest official meteorological observations by JMA (Japan Meteorological Agency) started at Hakodate in 1872, since which only 128 years have passed. Prior to that period, there was no official instrumental record in Japan. Recently, we could fortunately get information that several instrumental observations were taken under the responsibility of the Dutch in Dejima (Nagasaki) covering the periods 1819-1828, 1845-1858 and 1871-1878. As Nagasaki meteorological observatory was established in 1878, these Dutch instrumental series could be connected with the instrumental Nagasaki observatory series (1878-present). Although a lot of benefits are available in using long-term meteorological data for a study of climatic variations, there are some problems to be solved beforehand, such as inhomogeneity between historical data and modern data. In response to this fact mentioned above, we made the study of 1) making the database of Dejima/Nagasaki meteorological records for 180 years since 1819; 2) homogenizing monthly mean temperatures; 3) analyzing climate evolution in Nagasaki since early 19th century; and 4) developing and constructing the method for homogenizing daily mean temperatures. Firstly, in order to make the data base of Dejima/Nagasaki records, all meteorological elements (temperature, pressure, humidity, wind and precipitation) in Dutch records were converted to the same units as the present ones and digitized into the computer readable form. Secondly, inhomogenized monthly mean temperature data were completed by applying the mean calculation and height correction method, and the Jones et al. (1986) method. The latter method would be reasonable compared to the former method. Thirdly, climate variability of homogenized monthly mean temperature in Nagasaki was analyzed by comparing to the estimated temperatures from

  13. PREFACE: 19th International Conference on the Application of High Magnetic Fields in Semiconductor Physics and Nanotechnology (HMF-19)

    NASA Astrophysics Data System (ADS)

    Muraki, Koji; Takeyama, Shojiro

    2011-12-01

    This volume contains invited and contributed papers from the 19th International Conference on the Application of High Magnetic Fields in Semiconductor Physics and Nanotechnology (HMF-19) held in Fukuoka, Japan, from 1-6 August 2010. This conference was mainly sponsored by the Tokyo University-'Horiba International fund', which was donated by Dr Masao Horiba, the founder of Horiba Ltd. The scientific program of HMF-19 consisted of 37 invited talks, 24 contributed talks, and 83 posters, which is available from the conference homepage http://www.hmf19.iis.u-tokyo.ac.jp/index.html. Each manuscript submitted for publication in this volume has been independently reviewed. The Editor is very grateful to all the reviewers for their quick responses and helpful reports and to all the authors for their submissions and patience for the delay in the editorial process. Finally, the Editor would like to express his sincere gratitude to all the individuals involved in the conference organization and all the attendees, who made this conference so successful. Koji Muraki Conference photograph Committees Chair Conference chairS Takeyama(ISSP-UT) Conference secretary T Machida (IIS-UT) Program chair K Muraki (NTT) Local organizing chair K Oto (Chiba Univ.) Advisory Committee International Domestic L Brey (ES) T Ando (TIT) Z H Chen (CN) Y Hirayama (Tohoku Univ.) S Das Sarma (US) G Kido (NIMS) L Eaves (GB) N Miura (JP) J P Eisenstein (US) J Nitta (Tohoku Univ.) K Ensslin (CH) T Takamasu (NIMS) J Furdyna (US) G M Gusev (BR) I Kukushkin (RU) Z D Kvon (RU) G Landwehr (DE) J C Maan (NL) A H MacDonald (US) N F Oliveira Jr (BR) A Pinczuk (US) J C Portal (FR) A Sachrajda (CA) M K Sanyal(IN) R Stepniewski(PL) Program Committee Chair: K Muraki(NTT) International Domestic G Bauer (AU) H Ajiki (Osaka Univ.) G Boebinger (US) H Aoki (Hongo, UT) S Ivanov (RU) K Nomura (RIKEN) K von Klitzing (DE) T Okamoto (Hongo, UT) R Nicholas (GB) T Osada (ISSP-UT ) M Potemski (FR) N Studart (BR) U Zeitler (NL

  14. Improvements in the wallpaper industry during the second half of the 19th century: micro-Raman spectroscopy analysis of pigmented wallpapers.

    PubMed

    Castro, K; Vandenabeele, P; Rodríguez-Laso, M D; Moens, L; Madariaga, J M

    2005-08-01

    Scientific studies of the pigments used in the manufacturing process of some pigmented wallpapers are presented in this work. Non-destructive micro-Raman spectroscopy was selected for this purpose, and provides important information about how the 19th century wallpaper industry incorporated new materials in their works and designs. At the same time, analysis can help to date the samples of uncatalogued wallpapers. Chrome yellow, burnt Sienna, Prussian blue, ultramarine blue, red lead, carbon black, calcium carbonate, red iron oxide and a red organic pigment were identified. According to the palette used, as well as to the manufacturing process, the wallpapers in this study can be dated to the second half of the 19th century.

  15. Improvements in the wallpaper industry during the second half of the 19th century: Micro-Raman spectroscopy analysis of pigmented wallpapers

    NASA Astrophysics Data System (ADS)

    Castro, K.; Vandenabeele, P.; Rodríguez-Laso, M. D.; Moens, L.; Madariaga, J. M.

    2005-08-01

    Scientific studies of the pigments used in the manufacturing process of some pigmented wallpapers are presented in this work. Non-destructive micro-Raman spectroscopy was selected for this purpose, and provides important information about how the 19th century wallpaper industry incorporated new materials in their works and designs. At the same time, analysis can help to date the samples of uncatalogued wallpapers. Chrome yellow, burnt Sienna, Prussian blue, ultramarine blue, red lead, carbon black, calcium carbonate, red iron oxide and a red organic pigment were identified. According to the palette used, as well as to the manufacturing process, the wallpapers in this study can be dated to the second half of the 19th century.

  16. Proceedings of the Conference on Behavior Representation in Modeling and Simulation (19th), held in Charleston, South Carolina, 21 - 24 March 2010

    DTIC Science & Technology

    2010-03-01

    34 "Proceedings of the National Academy of Sciences USA," and leading field journals. Popular accounts have appeared in newspapers, magazines, books, online ... online at http://brimsconference.org/archives/2007/abstract/07bri ms-203.htm Proceedings of the 19th Conference on Behavior Representation in...three high school students explored an online IMMEXTM problem space where the goal was to make a decision whether the simulated person should seek

  17. A probabilistic approach to composite micromechanics

    NASA Technical Reports Server (NTRS)

    Stock, T. A.; Bellini, P. X.; Murthy, P. L. N.; Chamis, C. C.

    1988-01-01

    Probabilistic composite micromechanics methods are developed that simulate expected uncertainties in unidirectional fiber composite properties. These methods are in the form of computational procedures using Monte Carlo simulation. A graphite/epoxy unidirectional composite (ply) is studied to demonstrate fiber composite material properties at the micro level. Regression results are presented to show the relative correlation between predicted and response variables in the study.

  18. Key micromechanics issues in integrated material design

    NASA Astrophysics Data System (ADS)

    Bennoura, M.; Aboutajeddine, A.

    2017-03-01

    Nowadays the acceleration of material discovery is essential more than ever to hold the fast evolving requirements of innovative products. This acceleration depends on our ability to set up a material design process for tailoring materials from targeted engineering performances. One of the important building block passages, in the material design journey, is the bridging of micro-scale to meso-scale through micromechanical models. Unfortunately, these models include a lot of uncertainties resulting from their inbuilt ad-hoc assumptions, which inevitably impacts the material design process performance. In the present paper, robust design methods are reviewed and subsequently applied to quantify uncertainty in micromechanical models and mitigate its impact on material design performances. This includes examining principles for evaluating the level degree of uncertainty on material design process, and their use in micromechanical models. Also, developing robust design approaches to alleviate uncertainty effects and improve the quality of the design performance. Ultimately, the limitations of these approaches are discussed and the research opportunities, to overcome the shortness of actual approaches in respect to micromechanical models, are clarified.

  19. Micromechanical Modeling of Woven Metal Matrix Composites

    NASA Technical Reports Server (NTRS)

    Bednarcyk, Brett A.; Pindera, Marek-Jerzy

    1997-01-01

    This report presents the results of an extensive micromechanical modeling effort for woven metal matrix composites. The model is employed to predict the mechanical response of 8-harness (8H) satin weave carbon/copper (C/Cu) composites. Experimental mechanical results for this novel high thermal conductivity material were recently reported by Bednarcyk et al. along with preliminary model results. The micromechanics model developed herein is based on an embedded approach. A micromechanics model for the local (micro-scale) behavior of the woven composite, the original method of cells (Aboudi), is embedded in a global (macro-scale) micromechanics model (the three-dimensional generalized method of cells (GMC-3D) (Aboudi). This approach allows representation of true repeating unit cells for woven metal matrix composites via GMC-3D, and representation of local effects, such as matrix plasticity, yarn porosity, and imperfect fiber-matrix bonding. In addition, the equations of GMC-3D were reformulated to significantly reduce the number of unknown quantities that characterize the deformation fields at the microlevel in order to make possible the analysis of actual microstructures of woven composites. The resulting micromechanical model (WCGMC) provides an intermediate level of geometric representation, versatility, and computational efficiency with respect to previous analytical and numerical models for woven composites, but surpasses all previous modeling work by allowing the mechanical response of a woven metal matrix composite, with an elastoplastic matrix, to be examined for the first time. WCGMC is employed to examine the effects of composite microstructure, porosity, residual stresses, and imperfect fiber-matrix bonding on the predicted mechanical response of 8H satin C/Cu. The previously reported experimental results are summarized, and the model predictions are compared to monotonic and cyclic tensile and shear test data. By considering appropriate levels of porosity

  20. Present and Future Security Challenges in Northern Europe

    DTIC Science & Technology

    2002-04-09

    navies" were impossible without Nordic/Baltic supplies. The Nordic dynasties were instrumental to the creation of Europe and the modem world. From the...140 to the early 19th century, war between Scandinavian dynasties and adjacent kingdoms for regional predominance and European "great power" status...to halt Romanov expansion, the Nordic states have been the minor players and most often pawns in European power players’ efforts to solve the

  1. Probabilistic micromechanics for high-temperature composites

    NASA Technical Reports Server (NTRS)

    Reddy, J. N.

    1993-01-01

    The three-year program of research had the following technical objectives: the development of probabilistic methods for micromechanics-based constitutive and failure models, application of the probabilistic methodology in the evaluation of various composite materials and simulation of expected uncertainties in unidirectional fiber composite properties, and influence of the uncertainties in composite properties on the structural response. The first year of research was devoted to the development of probabilistic methodology for micromechanics models. The second year of research focused on the evaluation of the Chamis-Hopkins constitutive model and Aboudi constitutive model using the methodology developed in the first year of research. The third year of research was devoted to the development of probabilistic finite element analysis procedures for laminated composite plate and shell structures.

  2. Falsehood on the move. The Aztec children and science in the second half of the 19th century.

    PubMed

    Podgorny, Irina

    2014-01-01

    Allegedly kidnapped from a secret city in Central America, the "Aztec children" began a showman's career in the early-1850s. They died around 1900, after being observed by countless pathologists and ethnologists from Europe and the US. Most of the literature on the "Aztec children" has emphasized racial theories, the imperial gaze, and the character of "ethnological shows", where monstrosity and ethnicity were practically synonymous. Less attention has been paid to the fact that scientists continuously insisted that the case was false, an argument that instead of debunking the myth of the "Aztec children", contributed to establishing the "Aztecs" as "a matter of fact". In examining the case of the "Aztec children", this essay aims to explore what can be called the shifting nature or elusiveness of falsehood.

  3. [Cathedrals to sciences or temples of knowledge? The museums of natural sciences of Cordoba, Argentina, by the end of the 19th century].

    PubMed

    Tognetti, L

    2001-01-01

    The museums of Botany, Mineralogy and Zoology of the Facultad de Ciencias Físico-Matemáticas were created along with a world wide phenomenon, defined by some authors as the "museum movement," in a time the basics of this movement were being restructured. Thus, this work intends to go over the building stage of the natural history museums in a peripheral domain --- Cordoba by the end of the 19th century --- in order to partially understand this transition process. The strategy is to analyze the collections and find out how and why they were gathered. Two other aspects are also relevant: the human resources and the funds these institutions were granted.

  4. Micromechanical apparatus for measurement of forces

    DOEpatents

    Tanner, Danelle Mary; Allen, James Joe

    2004-05-25

    A new class of micromechanical dynamometers has been disclosed which are particularly suited to fabrication in parallel with other microelectromechanical apparatus. Forces in the microNewton regime and below can be measured with such dynamometers which are based on a high-compliance deflection element (e.g. a ring or annulus) suspended above a substrate for deflection by an applied force, and one or more distance scales for optically measuring the deflection.

  5. [The mind on the stage of justice: the formation of criminal psychology in the 19th century and its interdisciplinary research].

    PubMed

    Vec, Milos

    2007-09-01

    Criminal psychology emerges at the end of the 18th century as a new academic discipline in lectures and publications. It has recently been investigated by a considerable number of contributions from researchers of different academic backgrounds. In many respects criminal psychology can be seen as a predecessor of criminology. Its subject is the analysis of the origins of crime and its causes and determinants in the human mind. Criminal psychology embraced at that time philosophical, medical, legal and biological aspects. The latter increase in importance in the second half of the 19th century. The conditions of individual responsibility were generally codified in penal law, but had to be individually investigated in crucial cases through expertise in court. There a conflict emerged between medical experts and judges about their ability and competence to decide. At the end of the 19th century criminal psychology is used to fulfil the needs and interests of a criminal law which understands itself as increasingly utilitarian. Force and new instruments of treatment of offenders were legitimized by scientists who were very optimistic about their own epistemological abilities.

  6. Chapter 52: the emergence of the age variable in 19th-century neurology: considerations of recovery patterns in acquired childhood aphasia.

    PubMed

    Hellal, Paula; Lorch, Marjorie P

    2010-01-01

    In the 19th century, descriptions of patients with disorders of higher cerebral functions were typically presented in a mixed series of children, adolescents, adults, and the elderly. There was no indication in the analysis or interpretation that age was thought to play a role in the signs or symptoms displayed, or in the prognosis. The role of age in the manifestation of language disorders only became explicit in the late 19th century in the elaboration of ideas regarding perinatal illnesses, developmental difficulties, and the emerging clinical category of "cerebral palsy" as evinced in the work of Bastian, Osler, Sachs and Peterson, and Freud. Their patient series studies afforded the opportunity to identify relations between age at symptom onset and patterns of language acquisition and impairment. These analyses contributed directly to the elaboration of hypotheses regarding localization of function, hemispheric specialization, and patterns of recovery. The factor of "age at symptom onset" would steadily assume even greater theoretical importance, as explanations of patterns of symptom co-occurrence, etiology, and prognosis were elaborated through the increasing appreciation of a developmental/maturational perspective.

  7. Mapping the Elephants of the 19th Century East African Ivory Trade with a Multi-Isotope Approach

    PubMed Central

    Lee-Thorp, Julia; Collins, Matthew J.; Lane, Paul J.

    2016-01-01

    East African elephants have been hunted for their ivory for millennia but the nineteenth century witnessed strongly escalating demand from Europe and North America. It has been suggested that one consequence was that by the 1880s elephant herds along the coast had become scarce, and to meet demand, trade caravans trekked farther into interior regions of East Africa, extending the extraction frontier. The steady decimation of elephant populations coupled with the extension of trade networks have also been claimed to have triggered significant ecological and socio-economic changes that left lasting legacies across the region. To explore the feasibility of using an isotopic approach to uncover a ‘moving frontier’ of elephant extraction, we constructed a baseline isotope data set (δ13C, δ15N, δ18O and 87Sr/86Sr) for historic East African elephants known to have come from three distinct regions (coastal, Rift Valley, and inland Lakes). Using the isotope results with other climate data and geographical mapping tools, it was possible to characterise elephants from different habitats across the region. This baseline data set was then used to provenance elephant ivory of unknown geographical provenance that was exported from East Africa during the late nineteenth and early twentieth centuries to determine its likely origin. This produced a better understanding of historic elephant geography in the region, and the data have the potential to be used to provenance older archaeological ivories, and to inform contemporary elephant conservation strategies. PMID:27760152

  8. Mapping the Elephants of the 19th Century East African Ivory Trade with a Multi-Isotope Approach.

    PubMed

    Coutu, Ashley N; Lee-Thorp, Julia; Collins, Matthew J; Lane, Paul J

    2016-01-01

    East African elephants have been hunted for their ivory for millennia but the nineteenth century witnessed strongly escalating demand from Europe and North America. It has been suggested that one consequence was that by the 1880s elephant herds along the coast had become scarce, and to meet demand, trade caravans trekked farther into interior regions of East Africa, extending the extraction frontier. The steady decimation of elephant populations coupled with the extension of trade networks have also been claimed to have triggered significant ecological and socio-economic changes that left lasting legacies across the region. To explore the feasibility of using an isotopic approach to uncover a 'moving frontier' of elephant extraction, we constructed a baseline isotope data set (δ13C, δ15N, δ18O and 87Sr/86Sr) for historic East African elephants known to have come from three distinct regions (coastal, Rift Valley, and inland Lakes). Using the isotope results with other climate data and geographical mapping tools, it was possible to characterise elephants from different habitats across the region. This baseline data set was then used to provenance elephant ivory of unknown geographical provenance that was exported from East Africa during the late nineteenth and early twentieth centuries to determine its likely origin. This produced a better understanding of historic elephant geography in the region, and the data have the potential to be used to provenance older archaeological ivories, and to inform contemporary elephant conservation strategies.

  9. Science Policy at the Wrong Scale and Without Adequate Political Institutions: Parallels between the U.S. 19th Century and the 21st Century Global Contexts

    NASA Astrophysics Data System (ADS)

    McCurdy, K. M.

    2012-12-01

    The Constitution of the United States is a document for economic development written by people wary of government failure at the extremes, whether too heavy handed a central government or too loose a confederation. The strong central government favored by Hamilton, Industrialists and later by forward thinking men of the 19th century created a discontinuity wherein government institutions designed to facilitate agriculture were incapable of regulating corporations operating on a national scale, which made mineral and other natural resource exploitation needed to support industrialization enormously profitable. At the same time, Agriculturalists and other conservative citizens sought to control the economy by protecting their rural interests and power. The political institutional power remained with states as agriculturalists and industrialists struggled for economic superiority in the 19th century. As Agriculture moved west, Science warned of the dangers of extending Homesteading regulations into arid regions to no avail. The west was settled in townships without concern for watersheds, carrying capacity, or climatic variability. Gold seekers ignored the consequences of massive hydraulic mining techniques. The tension resident in the Constitution between strong local control of government (states' rights) and a strong central government (nationalism) provided no institutional context to resolve mining problems or other 19th century policy problems linked to rapid population expansion and industrialization. Environmental protection in the late 20th century has been the last wave of nationalized policy solutions following the institution-building blueprint provided by electoral successes in the Progressive, New Deal, and Great Society eras. Suddenly in the 21st century, scientific warnings of dangers again go unheeded, this time as evidence of global warming mounts. Again, tension in policy making exists in all political arenas (executive, legislative and judicial at

  10. Wireless actuation of bulk acoustic modes in micromechanical resonators

    NASA Astrophysics Data System (ADS)

    Mateen, Farrukh; Brown, Benjamin; Erramilli, Shyamsunder; Mohanty, Pritiraj

    2016-08-01

    We report wireless actuation of a Lamb wave micromechanical resonator from a distance of over 1 m with an efficiency of over 15%. Wireless actuation of conventional micromechanical resonators can have broad impact in a number of applications from wireless communication and implantable biomedical devices to distributed sensor networks.

  11. Human teeth as historical biomonitors of environmental and dietary lead: some lessons from isotopic studies of 19th and 20th century archival material.

    PubMed

    Farmer, J G; MacKenzie, A B; Moody, G H

    2006-10-01

    The lead isotopic composition of various sections (crown, crown base, root) of teeth was determined in specimens collected from 19th century skulls preserved in museum collections and, upon extraction or exfoliation, from humans of known ages residing in Scotland in the 1990s. For most 20th century samples, calculation of accurate crown-complete or root-complete dates of tooth formation ranging from the 1920s to the 1990s enabled comparison of (206)Pb/(207)Pb ratios for teeth sections (crown base root) with corresponding decadally averaged data for archival herbarium Sphagnum moss samples. This showed that the teeth sections had been significantly influenced by incorporation of non-contemporaneous (more recent) lead subsequent to the time of tooth formation, most probably via continuous uptake by dentine. This finding confirmed that separation of enamel from dentine is necessary for the potential of teeth sections as historical biomonitors of environmental (and dietary) lead exposure at the time of tooth formation to be realised. Nevertheless, the mean 19th century value of 1.172+/-0.007 for the (206)Pb/(207)Pb ratio in teeth was very similar to the corresponding mean value of 1.173+/-0.004 for 19th century archival moss, although relative contributions from environmental sources - whether direct, by inhalation/ingestion of dust contaminated by local lead smelting ((206)Pb/(207)Pb~1.17) and coal combustion ((206)Pb/(207)Pb~1.18) emissions, or indirect, through ingestion of similarly contaminated food - and drinking/cooking water contaminated by lead pipes of local origin, cannot readily be determined. In the 20th century, however, the much lower values of the (206)Pb/(207)Pb ratio (range 1.100-1.166, mean 1.126+/-0.013, median 1.124) for the teeth collected from various age groups in the 1990s reflect the significant influence of imported Australian lead of lower (206)Pb/(207)Pb ratio (~1.04) and released to the environment most notably through car

  12. Micromechanical Origin of Particle Size Segregation

    NASA Astrophysics Data System (ADS)

    Jing, L.; Kwok, C. Y.; Leung, Y. F.

    2017-03-01

    We computationally study the micromechanics of shear-induced size segregation and propose distinct migration mechanisms for individual large and small particles. While small particles percolate through voids without enduring contacts, large particles climb under shear through their crowded neighborhoods with anisotropic contact network. Particle rotation associated with shear is necessary for the upward migration of large particles. Segregation of large particles can be suppressed with inadequate friction, or with no rotation; increasing interparticle friction promotes the migration of large particles, but has little effect on the percolation of small particles.

  13. Approximate Micromechanics Treatise of Composite Impact

    NASA Technical Reports Server (NTRS)

    Chamis, Christos C.; Handler, Louis M.

    2005-01-01

    A formalism is described for micromechanic impact of composites. The formalism consists of numerous equations which describe all aspects of impact from impactor and composite conditions to impact contact, damage progression, and penetration or containment. The formalism is based on through-the-thickness displacement increments simulation which makes it convenient to track local damage in terms of microfailure modes and their respective characteristics. A flow chart is provided to cast the formalism (numerous equations) into a computer code for embedment in composite mechanic codes and/or finite element composite structural analysis.

  14. Micromechanics of composite laminate compression failures

    NASA Technical Reports Server (NTRS)

    Guynn, E. Gail; Bradley, Walter L.

    1988-01-01

    The purpose of this annual progress report is to summarize the work effort and results accomplished from July 1987 through July 1988 on NASA Research Grant NAG1-659 entitled Micromechanics of Composite Laminate Compressive Failure. The report contains: (1) the objective of the proposed research, (2) the summary of accomplishments, (3) a more extensive review of compression literature, (4) the planned material (and corresponding properties) received to date, (5) the results for three possible specimen geometries, experimental procedures planned, and current status of the experiments, and (6) the work planned for the next contract year.

  15. Force based displacement measurement in micromechanical devices

    SciTech Connect

    O {close_quote}Shea, S. J.; Ng, C. K.; Tan, Y. Y.; Xu, Y.; Tay, E. H.; Chua, B. L.; Tien, N. C.; Tang, X. S.; Chen, W. T.

    2001-06-18

    We demonstrate how force detection methods based on atomic force microscopy can be used to measure displacement in micromechanical devices. We show the operation of a simple microfabricated accelerometer, the proof mass of which incorporates a tip which can be moved towards an opposing surface. Both noncontact operation using long range electrostatic forces and tapping mode operation are demonstrated. The displacement sensitivity of the present device using feedback to control the tip-surface separation is approximately 1 nm. {copyright} 2001 American Institute of Physics.

  16. Simplified composite micromechanics for predicting microstresses

    NASA Technical Reports Server (NTRS)

    Chamis, C. C.

    1986-01-01

    A unified set of composite micromechanics equations is summarized and described. This unified set is for predicting the ply microstresses when the ply stresses are known. The set consists of equations of simple form for predicting three-dimensional stresses (six each) in the matrix, fiber, and interface. Several numerical examples are included to illustrate use and computational effectiveness of the equations in this unified set. Numerical results from these examples are discussed with respect to their significance on microcrack formation and, therefore, damage initiation in fiber composites.

  17. In naming the dead: Autosomal and Y-chromosomal STR typing on human skeletal remains from an 18th/19th century aristocratic crypt in Gallspach, Upper Austria.

    PubMed

    Schwarz, Reinhard; Renhart, Silvia; Gruber, Heinz; Kli Mesch, Wolfgang; Neuhuber, Franz; Cemper-Kiesslich, Jan

    2015-01-01

    Ancient DNA analyses have shown to be a powerful tool in the joint transdisciplinary assessment of archaeological records involving human remains. In this study we set out to identify single inhumations by synoptically evaluating the historical, archaeological, anthropological and molecular records on human remains from the crypt of the aristocratic family of Hoheneck (or: Hohenegg) dating to the 18(th) and 19(th) century AD. A total of 11 individuals were under investigation, yielding complete autosomal and Y-chromosomal STR profiles for 5 persons clearly showing a family group. DNA results, anthropological data and archaeological records taken together resulted in (almost) unambiguous correlation to historical records on the persons entombed in the crypt.

  18. Rise of the mutants: report from the 19th conference of the European Haematology Association, Milan, 12-15 June 2014.

    PubMed

    Mazzarella, Luca

    2014-01-01

    At the 19th conference of the European Haematology Association in Milan, we saw the true and dramatic changes brought about by the integration of extensive genomic information in clinical practice, and the dilemmas that accompany such a rapid increase in knowledge. Each disease is sliced more and more into smaller pieces, each with its own better-determined outcome and treatment. We also observed the rise of mutant-specific epigenetic agents, which benefit from knowing the underlying genetic abnormality to specifically assign an epigenetic drug where it is needed. In contrast to the 'one mutation, one drug' approach, others are pursuing the search for drugs targeting pathways fundamental for the survival of all or most cancer cells, sometimes looking at more 'exotic' pathways like neddylation or nuclear export.

  19. Finnish wallpaper pigments in the 18th-19th century: Presence of KFe3(CrO4)2(OH)6 and odd pigment mixtures

    NASA Astrophysics Data System (ADS)

    Castro, Kepa; Knuutinen, Ulla; Vallejuelo, Silvia Fdez-Ortiz de; Irazola, Mireia; Madariaga, Juan Manuel

    2013-04-01

    Several Finish wallpapers from the 18th and 19th century were analysed by using Raman spectroscopy assisted with EDXRF instrumentation, in an attempt of determine the pigments used in their manufacture process as well as of trying to date some of the samples through pigment composition. All pigments present in samples were determined and surprisingly the unusual and strange iron (III) chromate yellow pigment was found. Besides, unusual mixtures were found to obtain fashionable colours, especially in blue and green areas, where more than one blue pigments were mixed with green and yellow pigments. Blue verditer, ultramarine blue, Prussian blue, chrome yellow, calcite, lead white, red and yellow iron oxide, gypsum and carbon black were identified. The presence of the risky and poisonous emerald green must be highlighted. The results were compared with those found in other wallpapers from Spain and France.

  20. Finnish wallpaper pigments in the 18th-19th century: presence of KFe3(CrO4)2(OH)6 and odd pigment mixtures.

    PubMed

    Castro, Kepa; Knuutinen, Ulla; de Vallejuelo, Silvia Fdez-Ortiz; Irazola, Mireia; Madariaga, Juan Manuel

    2013-04-01

    Several Finish wallpapers from the 18th and 19th century were analysed by using Raman spectroscopy assisted with EDXRF instrumentation, in an attempt of determine the pigments used in their manufacture process as well as of trying to date some of the samples through pigment composition. All pigments present in samples were determined and surprisingly the unusual and strange iron (III) chromate yellow pigment was found. Besides, unusual mixtures were found to obtain fashionable colours, especially in blue and green areas, where more than one blue pigments were mixed with green and yellow pigments. Blue verditer, ultramarine blue, Prussian blue, chrome yellow, calcite, lead white, red and yellow iron oxide, gypsum and carbon black were identified. The presence of the risky and poisonous emerald green must be highlighted. The results were compared with those found in other wallpapers from Spain and France.

  1. J. M. Despréaux' lichens from the Canary Islands and West Africa: an account of a 19th century collection found in an English archive.

    PubMed

    Aguirre-Hudson, Begoña; Whitworth, Isabella; Spooner, Brian M

    2011-01-01

    This is an historical and descriptive account of 28 herbarium specimens, 27 lichens and an alga, found in the archives of Charles Chalcraft, a descendant of the Bedford family, who were dye manufacturers in Leeds, England, in the 19th century. The lichens comprise 13 different morphotypes collected in the Canary Islands and West Africa by the French botanist J. M. Despréaux between 1833 and 1839. The collections include samples of "Roccella fuciformis", "R. phycopsis" and "R. tinctoria" (including the fertile morphotype "R. canariensis"), "Ramalina crispatula" and "R. cupularis", two distinct morphotypes of "Sticta", "S. canariensis" and "S. dufouri", "Physconia enteroxantha", "Pseudevernia furfuracea var. ceratea" and "Pseudocyphellaria argyracea". The herbarium also includes authentic material of "Parmotrema tinctorum" and a probable syntype of "Seirophora scorigena". Most of these species are known as a source of the purple dye orchil, which was used to dye silk and wool.

  2. Widow and widower remarriage: an analysis in a rural 19th century Costa Rican population and a cross-cultural discussion.

    PubMed

    Madrigal, L; Ware, B; Melendez, M

    2003-12-01

    Although the topic of remarriage features saliently in the cultural anthropological literature, it is virtually absent in the biological anthropology journals. This is perplexing, given that remarriage affects the differential reproductive success of males and females in a community, and could well impact a community's population structure. In this paper, we research remarriage practices in a rural 19th century community in Costa Rica. Although we find support for the proposition that males are more likely to remarry than females, we find that widows who remarry are not all young and able to reproduce. Our findings support the cross-culturally-generated suggestion that a female's ability not to remarry is tied to her to ability to own property. Remarriage is a topic of interest to biological anthropologists from a cross-cultural and biocultural perspective.

  3. The Use of Complementary GPR Surveys with Different Grid Spacing to Locate Unmarked Graves in a 19th Century Cemetery in Selinsgrove PA

    NASA Astrophysics Data System (ADS)

    Lachhab, A.; Zawacki, A.

    2014-12-01

    Ground-penetrating radar (GPR) is a geophysical survey tool with many archaeological applications, including the search for graves. A 400 megahertz GPR was employed to locate unmarked graves and buried headstones in a neglected Pennsylvania cemetery dating from the 19th century. The site was initially scanned using a grid pattern with 50cm transect spacings. A smaller site within the cemetery was then selected and scanned at a higher 'resolution,' using smaller transect spacings, to determine whether this improved the accuracy of the findings. Supplementary perpendicular transects were also added. A number of potential sources of error were identified and their consequences were outlined. Short transects with small spacings were found to significantly improve the quality of the obtained data, as was the addition of perpendicular transects. The results are applicable to the search for graves and, more broadly, the use of GPR to identify and locate other subsurface features.

  4. Dealing with Variability: Inter and Intra-annual Climate Variability and its Impacts on Water Availability in the 19th Century Northeastern United States

    NASA Astrophysics Data System (ADS)

    Aloysius, N. R.; Witherell, B. B.; Allen, T. L.; Arrigo, J. S.; Vorosmarty, C. J.

    2009-12-01

    Freshwater plays a critical role in preserving the biological and hydrological functions of the terrestrial ecosystems that sustain civilization. Hydrologic processes shape the distribution, structure, and dynamics of biological systems, while the feedbacks from biological systems impact the hydrologic cycle. Climate is the main driver that adds dynamics to the hydrologic cycle. In order to identify the changes and variability in the Northeast region’s climate and to understand their impacts on the hydrological cycle, we are conducting an assessment of the region’s climate. Annual and monthly time series of precipitation and temperature data collected for one hundred locations in the region, spanning from Maine to Virginia, during the period 1800 to 1920 are analyzed to assess the spatial and temporal variations in climate. It has been reported that the region’s climate during the 19th century is largely modulated by climatic oceanicity and the sunspot rhythm, and, that human influence did not have significant impact on the regional climate. Our preliminary findings do not show significant variations in the mean annual climate, but show variations in intra-annual climate, particularly monthly precipitation. Based on the review of historical documents, the intra-annual variation in precipitation was a concern of water resource planners during the 19th century. The present research attempts to bring out linkages between spatial and temporal variations in the regional climate and water availability. Additional information on land cover, measured and modeled runoff for a selected location will be used as case study to highlight climate variability and its impact on water availability.

  5. [Records of the invisible: Visa reperta in 18th- and 19th-century forensic medicine and their role as promoters of pathological-anatomical knowledge].

    PubMed

    Müller, Irmgard; Fangerau, Heiner

    2010-01-01

    Case reports in medicine serve as a tool to collect and to transfer knowledge. A special kind of case report in forensic medicine during the 18th and 19th centuries was the so-called Visum repertum. This format of note-taking and of rendering an expert opinion without presuppositions has rarely investigated in the history of medicine. Analyzing Visa reperta the authors argue that due to their special structure and mode of representation Visa reperta not only shaped the practice of forensic medicine but also the standardized examination and documentation in pathological anatomy. Based on previous studies on medical case reports, medical expert witnesses in court and traditions in pathological anatomy the authors examine two examples from the 18th and 19th centuries in order to show how semiological, classifying methods of presenting forensic examinations were replaced by the material aspect of the observation of examination results itself. The examples are a forensic case report by Michael Alberti (1682-1757) from 1728 and a Visum repertum by Joseph Bernt (1770-1842) from 1827. The authors argue that Visa reperta transcended their original forensic purpose and served as a guideline for pathology leading to an understanding of the origin of diseases in organs. They served as a promoter of scientific medicine, and their persuasiveness was backed by factors such as (a) the extreme conditions of forensic practice, (b) the claim to act as a tool for the sound and precise recording of facts and c) the awareness that they documented objects that were destroyed during the process of documentation.

  6. [The physician between the ideal and reality: medical profession and popular attitude towards health and medicine in the 19th century].

    PubMed

    Zeleznik, Urska

    2010-01-01

    This paper studies the attitude of the society towards the medical profession, which was torn between high social expectations and ideals and medical practice confronted with real-life obstacles. In the 19th century, the physician's position was still precarious and called for a renegotiation in the community. Physician's work was faced with people's distrust and resistance, superstitions and prejudices, folk medicine and religion. Even such ideal qualities as dignity, conscientiousness, and courage, would quickly be called into question by events such as epidemics. Particularly in 19th century rural areas, the physician's position was far from acknowledged and official medicine had yet to win people's trust. This paper explores the polyvalent attitude of people towards medicine and health. It investigates the discourse used to describe health and medicine in daily press, professional and popular literature, as well as in official medical documents of the time. It shows a long struggle of public health care to gain people's approval. During cholera epidemics, which apart from presenting serious threat to human life were an opportunity for medicine to win people's trust and obedience, the attitude towards health gradually began to change. To some extent this was a result of medical advances, new scientific discoveries, and increasing success in abating the epidemics. At the same time, as the society became more secular, medicine slowly gained people's trust and gradually replaced the healing methods of folk medicine. Health was less and less understood as a result of God's will and mercy, and the attitude towards disease began to evolve from passive resignation to an active battle for health.

  7. Historical stocking data and 19th century DNA reveal human-induced changes to native diversity and distribution of cutthroat trout.

    PubMed

    Metcalf, J L; Love Stowell, S; Kennedy, C M; Rogers, K B; McDonald, D; Epp, J; Keepers, K; Cooper, A; Austin, J J; Martin, A P

    2012-11-01

    Many species are threatened with extinction and efforts are underway worldwide to restore imperilled species to their native ranges. Restoration requires knowledge of species' historical diversity and distribution. For some species, many populations were extirpated or individuals moved beyond their native range before native diversity and distribution were documented, resulting in a lack of accurate information for establishing restoration goals. Moreover, traditional taxonomic assessments often failed to accurately capture phylogenetic diversity. We illustrate a general approach for estimating regional native diversity and distribution for cutthroat trout in the Southern Rocky Mountains. We assembled a large archive of historical records documenting human-mediated change in the distribution of cutthroat trout (Oncorhynchus clarkii) and combined these data with phylogenetic analysis of 19th century samples from museums collected prior to trout stocking activities and contemporary DNA samples. Our study of the trout in the Southern Rocky Mountains uncovered six divergent lineages, two of which went extinct, probably in the early 20th century. A third lineage, previously declared extinct, was discovered surviving in a single stream outside of its native range. Comparison of the historical and modern distributions with stocking records revealed that the current distribution of trout largely reflects intensive stocking early in the late 19th and early 20th century from two phylogenetically and geographically distinct sources. Our documentation of recent extinctions, undescribed lineages, errors in taxonomy and dramatic range changes induced by human movement of fish underscores the importance of the historical record when developing and implementing conservation plans for threatened and endangered species.

  8. The genetic legacy of the 19th-century decline of the British polecat: evidence for extensive introgression from feral ferrets.

    PubMed

    Costa, M; Fernandes, C; Birks, J D S; Kitchener, A C; Santos-Reis, M; Bruford, M W

    2013-10-01

    In the 19th century, the British polecat suffered a demographic contraction, as a consequence of direct persecution, reaching its lowest population in the years that preceded the First World War. The polecat is now recovering and expanding throughout Britain, but introgressive hybridization with feral ferrets has been reported, which could be masking the true range of the polecat and introducing domestic genes into the species. We used a fragment of the mitochondrial DNA control region and 11 microsatellite loci to characterize the frequency and extent of hybridization and introgression between the two species and assess whether the 19th-century decline corresponded to a genetic bottleneck in the polecat. The proportion of admixture detected in the wild was high (31%) and hybrids were more frequently found outside Wales, suggesting that hybridization is more likely to occur along the eastern edge of the polecat's range expansion. The patterns observed in the mitochondrial and nuclear DNA data show that introgression was mediated by crosses between male polecats and female ferrets, whose offspring backcrossed with polecats. No first-generation (F1 ) hybrids were identified, and the broad range of observed admixture proportions agrees with a scenario of past extensive hybridization between the two species. Using several different methods to investigate demographic history, we did not find consistent evidence for a genetic bottleneck in the British polecat, a result that could be interpreted as a consequence of hybridization with ferrets. Our results highlight the importance of the Welsh polecat population for the conservation and restoration of the genetic identity of the British polecat.

  9. Simplified Micromechanics of Plain Weave Composites

    NASA Technical Reports Server (NTRS)

    Mital, Subodh K.; Murthy, Pappu L. N.; Chamis, Christos C.

    1996-01-01

    A micromechanics based methodology to simulate the complete hygro-thermomechanical behavior of plain weave composites is developed. This methodology is based on micromechanics and the classical laminate theory. The methodology predicts a complete set of thermal, hygral and mechanical properties of plain woven composites, generates necessary data for use in a finite element structural analysis, and predicts stresses all the way from the laminate to the constituent level. This methodology is used in conjunction with a composite mechanics code to analyze and predict the properties/response of a generic graphite/epoxy woven textile composite and a plain weave ceramic composite. The fiber architecture, including the fiber waviness and fiber end distributions through the thickness, is properly accounted for. Predicted results compare reasonably well with those from detailed three-dimensional finite element analyses as well as available experimental data. However, the main advantage of the proposed methodology is its high computational efficiency as compared with three-dimensional finite element analyses.

  10. Method for forming suspended micromechanical structures

    DOEpatents

    Fleming, James G.

    2000-01-01

    A micromachining method is disclosed for forming a suspended micromechanical structure from {111} crystalline silicon. The micromachining method is based on the use of anisotropic dry etching to define lateral features of the structure which are etched down into a {111}-silicon substrate to a first etch depth, thereby forming sidewalls of the structure. The sidewalls are then coated with a protection layer, and the substrate is dry etched to a second etch depth to define a spacing of the structure from the substrate. A selective anisotropic wet etchant (e.g. KOH, EDP, TMAH, NaOH or CsOH) is used to laterally undercut the structure between the first and second etch depths, thereby forming a substantially planar lower surface of the structure along a {111} crystal plane that is parallel to an upper surface of the structure. The lateral extent of undercutting by the wet etchant is controlled and effectively terminated by either timing the etching, by the location of angled {111}-silicon planes or by the locations of preformed etch-stops. This present method allows the formation of suspended micromechanical structures having large vertical dimensions and large masses while allowing for detailed lateral features which can be provided by dry etch definition. Additionally, the method of the present invention is compatible with the formation of electronic circuitry on the substrate.

  11. Micromechanics of intraply hybrid composites: Elastic and thermal properties

    NASA Technical Reports Server (NTRS)

    Chamis, C. C.; Sinclair, J. H.

    1979-01-01

    Composite micromechanics are used to derive equations for predicting the elastic and thermal properties of unidirectional intraply hybrid composites. The results predicted using these equations are compared with those predicted using approximate equations based on the rule of mixtures, linear laminate theory, finite element analysis and limited experimental data. The comparisons for three different intraply hybrids indicate that all four methods predict approximately the same elastic properties and are in good agreement with measured data. The micromechanics equations and linear laminate theory predict about the same values for thermal expansion coefficients. The micromechanics equations predict through-the-thickness properties which are in good agreement with the finite element results.

  12. [Effects of physics on development of optometry in the United States from the late 19th to the mid 20th century].

    PubMed

    Kim, Dal-Young

    2014-08-01

    In this paper, it was studied how physics affected development of optometry in the United States, from aspects of formation and academization of optometry. It was also revealed that history of optometry was analogous to history of engineering. Optics in the 19th century was divided into electromagnetic study of light and visual optics. Development of the visual optics promoted professionalization of ophthalmology that had already started in the 18th century. The visual optics also stimulated formation of optometry and optometrists body in the late 19th century of the United States. The American optometrists body were originated from opticians who had studied visual optics. Publication of several English academic textbooks on visual optics induced appearance of educated opticians (and jewelers). They acquired a right to do the eye examination in the early 20th century after C. F. Prentice's trial in 1897, evolving into optometrists. The opticians could be considered as craftsmen, and they were divided into (dispensing) opticians and optometrists. Such history of American optometrists body is analogous to that of engineers body in the viewpoints of craftsmen origin and separation from craftsmen. Engineers were also originated from educated craftsmen, but were separated from craftsmen when engineering was built up. Education system and academization of optometry was strongly influenced by physics, too. When college education of optometry started at American universities, it was not belonged to medical school but to physics department. Physics and optics were of great importance in curriculum, and early faculty members were mostly physicists. Optometry was academized in the 1920s by the college education, standardization of curriculum, and formation of the American Academy of Optometry. This is also analogous to history of engineering, which was academized by natural sciences, especially by mathematics and physics. The reason why optometry was academized not by

  13. Apparatus for raising or tilting a micromechanical structure

    DOEpatents

    Allen, James J.

    2008-09-09

    An active hinge apparatus is disclosed which can be used to raise a micromechanical structure (e.g. a plate or micromirror) on a substrate. The active hinge apparatus utilizes one or more of teeth protruding outward from an axle which also supports the micromechanical structure on one end thereof. A rack is used to engage the teeth and rotate the axle to raise the micromechanical structure and tilt the structure at an angle to the substrate. Motion of the rack is provided by an actuator which can be a mechanically-powered actuator, or alternately an electrostatic comb actuator or a thermal actuator. A latch can be optionally provided in the active hinge apparatus to lock the micromechanical structure in an "erected" position.

  14. Future technologies. I - Microelectronics, micrometrology, and micromechanics

    NASA Astrophysics Data System (ADS)

    Becker, H.

    1986-04-01

    Recent developments in microelectronics design and manufacturing are reviewed, with an emphasis on the activity of West German research institutes and industry. The history of semiconductor development since 1948 is summarized; current efforts to produce submicron VHSICs with throughput 10 to the 13th Hz/sq cm at clock frequency 50 MHz are described; and consideration is given to emitter-coupled-logic gate arrays and GaAs devices. The use of optical measurement techniques or digital analysis of SEM images in fabricating or customizing microelectronic structure is examined, and Si-based sensors for a number of micromechanical applications (pressure sensors, CCD cameras, gas chromatographs, and temperature sensors) are discussed along with the anisotropic etching processes used to fabricate them.

  15. Coupling a Bose condensate to micromechanical oscillators

    NASA Astrophysics Data System (ADS)

    Kemp, Chandler; Fox, Eli; Flanz, Scott; Vengalattore, Mukund

    2011-05-01

    We describe the construction of a compact apparatus to investigate the interaction of a spinor Bose-Einstein condensate and a micromechanical oscillator. The apparatus uses a double magneto-optical trap, Raman sideband cooling, and evaporative cooling to rapidly produce a 87Rb BEC in close proximity to a high Q membrane. The micromotion of the membrane results in small Zeeman shifts at the location of the BEC due to a magnetic domain attached to the oscillator. Detection of this micromotion by the condensate results in a backaction on the membrane. We investigate prospects of using this backaction to generate nonclassical states of the mechanical oscillator. This work was funded by the DARPA ORCHID program.

  16. Micromechanical model for fibrous ceramic bodies

    NASA Technical Reports Server (NTRS)

    Green, D. J.; Lange, F. F.

    1982-01-01

    A micromechanical model is presented to relate the mechanical properties of low-density fibrous ceramic bodies to their microstructures and the properties of the fibers. It is found that properties such as the elastic moduli, fracture toughness, and strength depend on the fiber spacing. In particular, it is shown that the critical stress intensity (Kc) depends on the density of the body with respect to the fiber density, the degree of preferred orientation, the fiber strength, and the fiber radius, suggesting ways of increasing K(c). Furthermore, it is predicted that K(c) will be related to the sonic velocity in the material, reflecting variations in the degree of preferred orientation. The model is found to be consistent with the experimental observations on a silica-based fibrous ceramic, which is being used in the thermal protection system of the Space Shuttle.

  17. Micromechanical models for textile structural composites

    NASA Technical Reports Server (NTRS)

    Marrey, Ramesh V.; Sankar, Bhavani V.

    1995-01-01

    The objective is to develop micromechanical models for predicting the stiffness and strength properties of textile composite materials. Two models are presented to predict the homogeneous elastic constants and coefficients of thermal expansion of a textile composite. The first model is based on rigorous finite element analysis of the textile composite unit-cell. Periodic boundary conditions are enforced between opposite faces of the unit-cell to simulate deformations accurately. The second model implements the selective averaging method (SAM), which is based on a judicious combination of stiffness and compliance averaging. For thin textile composites, both models can predict the plate stiffness coefficients and plate thermal coefficients. The finite element procedure is extended to compute the thermal residual microstresses, and to estimate the initial failure envelope for textile composites.

  18. Micromechanics Modeling of Fracture in Nanocrystalline Metals

    NASA Technical Reports Server (NTRS)

    Glaessgen, E. H.; Piascik, R. S.; Raju, I. S.; Harris, C. E.

    2002-01-01

    Nanocrystalline metals have very high theoretical strength, but suffer from a lack of ductility and toughness. Therefore, it is critical to understand the mechanisms of deformation and fracture of these materials before their full potential can be achieved. Because classical fracture mechanics is based on the comparison of computed fracture parameters, such as stress intlmsity factors, to their empirically determined critical values, it does not adequately describe the fundamental physics of fracture required to predict the behavior of nanocrystalline metals. Thus, micromechanics-based techniques must be considered to quanti@ the physical processes of deformation and fracture within nanocrystalline metals. This paper discusses hndamental physicsbased modeling strategies that may be useful for the prediction Iof deformation, crack formation and crack growth within nanocrystalline metals.

  19. Micromechanical damage and fracture in elastomeric polymers

    NASA Astrophysics Data System (ADS)

    Heyden, Stefanie

    This thesis aims at a simple one-parameter macroscopic model of distributed damage and fracture of polymers that is amenable to a straightforward and efficient numerical implementation. The failure model is motivated by post-mortem fractographic observations of void nucleation, growth and coalescence in polyurea stretched to failure, and accounts for the specific fracture energy per unit area attendant to rupture of the material. Furthermore, it is shown that the macroscopic model can be rigorously derived, in the sense of optimal scaling, from a micromechanical model of chain elasticity and failure regularized by means of fractional strain-gradient elasticity. Optimal scaling laws that supply a link between the single parameter of the macroscopic model, namely the critical energy-release rate of the material, and micromechanical parameters pertaining to the elasticity and strength of the polymer chains, and to the strain-gradient elasticity regularization, are derived. Based on optimal scaling laws, it is shown how the critical energy-release rate of specific materials can be determined from test data. In addition, the scope and fidelity of the model is demonstrated by means of an example of application, namely Taylor-impact experiments of polyurea rods. Hereby, optimal transportation meshfree approximation schemes using maximum-entropy interpolation functions are employed. Finally, a different crazing model using full derivatives of the deformation gradient and a core cut-off is presented, along with a numerical non-local regularization model. The numerical model takes into account higher-order deformation gradients in a finite element framework. It is shown how the introduction of non-locality into the model stabilizes the effect of strain localization to small volumes in materials undergoing softening. From an investigation of craze formation in the limit of large deformations, convergence studies verifying scaling properties of both local- and non-local energy

  20. 19th International Seapower Symposium

    DTIC Science & Technology

    2010-07-01

    Derecho del Mar, or UNCLOS, the United Nations Convention on the Law of the Sea], the sea convention that deals with drug trafficking and the protection of...framework for info sharing. Quite clearly, I think the maritime challenges today take all countries, working col- laboratively , to deal with [them...the region. Especially in this era of fiscal constraints, col- laborating with regional partners can enhance the overall capacity in the region by

  1. [Insanity, life crises and longing for a "real life". On the discussion of deviant behavior and mental disorders in psychiatry of the 19th and 20th century].

    PubMed

    Kanis-Seyfried, Uta

    On insanity, life crises and the longing for a "right life". A contribution to the discussion on the deviant behavior and mental disorders in the psychiatry of the 19th and 20th centuries using the example of patient stories. History of psychiatry, understood as social and cultural history, provides the framework for this micro-historical article. Using the example of three patients treated in Wuerttemberg or Baden psychiatric asylums between 1875 and 1912, the article focuses on the critical analysis of types of asylums, their practices of admissions, therapies and power relations between patients and staff. Ways of thinking and acting, subjective experiences and emotions are exemplified by patient records, personal testimonials and contemporary publications again by patients and staff. The article examines options of patients to influence the institutional daily asylum routine against the background of its complexity and dynamics. Borders, manipulations, malingering and querulous paranoia are at stake here. Furthermore, the article reflects various forms of social interaction with the power regulating therapeutic and disciplinary aspects against the backdrop of the "canons of rules" of the asylum as well as the contemporary political and legal framework.

  2. By their words ye shall know them: Evidence of genetic selection against general intelligence and concurrent environmental enrichment in vocabulary usage since the mid 19th century.

    PubMed

    Menie, Michael A Woodley Of; Fernandes, Heitor B F; José Figueredo, Aurelio; Meisenberg, Gerhard

    2015-01-01

    It has been theorized that declines in general intelligence (g) due to genetic selection stemming from the inverse association between completed fertility and IQ and the Flynn effect co-occur, with the effects of the latter being concentrated on less heritable non-g sources of intelligence variance. Evidence for this comes from the observation that 19th century populations were more intellectually productive, and also exhibited faster simple reaction times than modern ones, suggesting greater information-processing ability and therefore higher g. This co-occurrence model is tested via examination of historical changes in the utilization frequencies of words from the highly g-loaded WORDSUM test across 5.9 million texts spanning the period 1850-2005. Consistent with predictions, words with higher difficulties (δ parameters from Item Response Theory) and stronger negative correlations between pass rates and completed fertility declined in use over time whereas less difficult and less strongly selected words, increased in use over time, consistent with a Flynn effect stemming in part from the vocabulary enriching effects of increases in population literacy. These findings persisted when explicitly controlled for word age, changing literacy rates and temporal autocorrelation. These trends constitute compelling evidence for the co-occurrence model.

  3. Non-invasive and non-destructive micro-XRF and micro-Raman analysis of a decorative wallpaper from the beginning of the 19th century.

    PubMed

    Castro, Kepa; Pérez-Alonso, Maite; Rodríguez-Laso, María Dolores; Etxebarria, Nestor; Madariaga, Juan Manuel

    2007-02-01

    Non-destructive and non-invasive micro-Raman fibre optic and micro-XRF analyses were performed to study a wallpaper from the beginning of the 19th century. The complementarity of these two non-destructive techniques is shown in this work. The analysed artwork is considered one of the most beautiful wallpapers ever manufactured according to the catalogues and books; it is known as Chasse de Compiègne, manufactured by Jacquemart, Paris, in 1812. During the analysis, an unexpected pigment was detected by both analytical techniques: lead-tin yellow type II. This pigment was used until ca. 1750, when other yellow pigments replaced it, thus it is very difficult to find it in paintings afterwards. Together with this pigment, red lead, Prussian blue, brochantite, yellow iron oxide, calcium carbonate, vermilion, carbon black of animal origin (bone black), lead white, and raw and burnt sienna were also determined by combining the analytical information provided by both techniques. A possible degradation of brochantite to antlerite is also discussed.

  4. [Incurable disease in Spain during the 19th century. The Hospital para Hombres Incurables Nuestra Señora del Carmen].

    PubMed

    Zaragoza, Juan Manuel

    2012-01-01

    This paper examines the State's assumption of medical care for patients with "permanent needs" in 19th century Spain. These patients were the incurably ill, the chronically ill and the elderly. This process is contextualized within the liberal reforms of the Spanish healthcare system in the reign of Isabel 11 (1833-1868). The goal of these reforms was the creation and consolidation of a national health system that would gradually replace the religious health charities. Healthcare reform became necessary due to the increase in migration that started in the 1830's and intensified in the 1850's. Traditional care networks formed by the family, local community and religious charities were no longer available to those who had left their village or town. In addition, many religious charities were bankrupted by the seizure of their properties in a programme of confiscation. Similar healthcare reform processes were taking place in the United Kingdom, France and Germany, among other European countries, and involved significant changes in the lives of patients, who became strictly controlled and medicalised. My aim was to identify changes in the patients' experience of illness through a case study of the living conditions of inmates at the Nuestra Señora del Carmen Hospital for Incurable Men, based in Madrid from 1852 to 1949. This was one of the institutions devoted to caring for patients with "permanent needs" and was under the direct control of the General State Administration.

  5. Quantitative analysis of human remains from 18(th)-19(th) centuries using X-ray fluorescence techniques: The mysterious high content of mercury in hair.

    PubMed

    Pessanha, Sofia; Carvalho, Marta; Carvalho, Maria Luisa; Dias, António

    2016-01-01

    In this work, we report the unusual concentration of mercury in the hair of an individual buried in the 18th to mid-19th centuries and the comparison with the elemental composition of other remains from the same individual. Two energy dispersive X-ray fluorescence (EDXRF) setups, one with tri-axial geometry and the second one with micro-beam capabilities and a vacuum system, for light elements detection, have been used. Quantitative evaluation of the obtained spectra were made by fundamental parameters and winAXIL program by compare mode method. The levels of Hg in the hair of buried samples presented a concentration over 5% (w/w), a significantly lower presence of this element in the cranium, and no Hg in the remaining organs. Furthermore, there was no evidence of Hg in the burial soil, which has been also analyzed. From this result, we could conclude that the possibility of post-mortem contamination from the burial surroundings is very unlikely. The obtained results are indicative of the apparent use of a mercury-based compound for medical purposes, most likely lice infestation.

  6. Understanding Edward Muybridge: historical review of behavioral alterations after a 19th-century head injury and their multifactorial influence on human life and culture.

    PubMed

    Manjila, Sunil; Singh, Gagandeep; Alkhachroum, Ayham M; Ramos-Estebanez, Ciro

    2015-07-01

    Edward Muybridge was an Anglo-American photographer, well known for his pioneering contributions in photography and his invention of the "zoopraxiscope," a forerunner of motion pictures. However, this 19th-century genius, with two original patents in photographic technology, made outstanding contributions in art and neurology alike, the latter being seldom acknowledged. A head injury that he sustained changed his behavior and artistic expression. The shift of his interests from animal motion photography to human locomotion and gait remains a pivotal milestone in our understanding of patterns in biomechanics and clinical neurology, while his own behavioral patterns, owing to an injury to the orbitofrontal cortex, remain a mystery even for cognitive neurologists. The behavioral changes he exhibited and the legal conundrum that followed, including a murder of which he was acquitted, all depict the complexities of his personality and impact of frontal lobe injuries. This article highlights the life journey of Muybridge, drawing parallels with Phineas Gage, whose penetrating head injury has been studied widely. The wide sojourn of Muybridge also illustrates the strong connections that he maintained with Stanford and Pennsylvania universities, which were later considered pinnacles of higher education on the two coasts of the United States.

  7. The Future of Instructional Technology. Summary Report of the Lake Okoboji Educational Media Leadership Conference (19th Iowa Lakeside Laboratory, Lake Okoboji, Milford, Iowa, August 12-17, 1973).

    ERIC Educational Resources Information Center

    Cochran, Lida M., Ed.; Cochran, Lee W., Ed.

    A summary is provided of the proceedings of the 19th Lake Okoboji Educational Media Leadership Conference. The first section of the report presents a transcript of the conference's keynote address, which deals with projections, probes and problems of instructional technology in the future. Brief reviews of each of the general sessions are next…

  8. "Do Not Turn a Deaf Ear or a Blind Eye on Me, as I Am Your Son": New Conceptions of Childhood and Parenthood in 18th- and 19th-Century Jewish Letter-Writing Manuals

    ERIC Educational Resources Information Center

    Kogman, Tal

    2016-01-01

    This article focuses on the cultural functions of Hebrew letter-writing manuals published in German-speaking countries in the 18th and 19th centuries, aimed at young people. I argue that these books, which were used frequently as textbooks for studying Hebrew writing, conveyed modern ideological values and at the same time corresponded to the…

  9. Pacific Visions: Finding, Selecting, and Using Resources for Your Libraries, Archives, and Museums. Selected Papers from PIALA 2009, Pacific Islands Association of Libraries, Archives, and Museums Annual Conference (19th, Pohnpei, Federated States of Micronesia, November 16-21, 2009)

    ERIC Educational Resources Information Center

    Drake, Paul B., Ed.

    2011-01-01

    This publication follows the tradition of publishing selected papers from Pacific Islands Association of Libraries, Archives and Museums (PIALA) annual conferences. This 19th annual conference was held in Pohnpei, Federated States of Micronesia, November 16-21, 2009. The volume begins with a listing of the members of the PIALA 2009 Planning…

  10. A Micromechanical INS/GPS System for Small Satellites

    NASA Technical Reports Server (NTRS)

    Barbour, N.; Brand, T.; Haley, R.; Socha, M.; Stoll, J.; Ward, P.; Weinberg, M.

    1995-01-01

    The cost and complexity of large satellite space missions continue to escalate. To reduce costs, more attention is being directed toward small lightweight satellites where future demand is expected to grow dramatically. Specifically, micromechanical inertial systems and microstrip global positioning system (GPS) antennas incorporating flip-chip bonding, application specific integrated circuits (ASIC) and MCM technologies will be required. Traditional microsatellite pointing systems do not employ active control. Many systems allow the satellite to point coarsely using gravity gradient, then attempt to maintain the image on the focal plane with fast-steering mirrors. Draper's approach is to actively control the line of sight pointing by utilizing on-board attitude determination with micromechanical inertial sensors and reaction wheel control actuators. Draper has developed commercial and tactical-grade micromechanical inertial sensors, The small size, low weight, and low cost of these gyroscopes and accelerometers enable systems previously impractical because of size and cost. Evolving micromechanical inertial sensors can be applied to closed-loop, active control of small satellites for micro-radian precision-pointing missions. An inertial reference feedback control loop can be used to determine attitude and line of sight jitter to provide error information to the controller for correction. At low frequencies, the error signal is provided by GPS. At higher frequencies, feedback is provided by the micromechanical gyros. This blending of sensors provides wide-band sensing from dc to operational frequencies. First order simulation has shown that the performance of existing micromechanical gyros, with integrated GPS, is feasible for a pointing mission of 10 micro-radians of jitter stability and approximately 1 milli-radian absolute error, for a satellite with 1 meter antenna separation. Improved performance micromechanical sensors currently under development will be

  11. Micromechanics of Spray-On Foam Insulation

    NASA Technical Reports Server (NTRS)

    Bednarcyk, Brett A.; Aboudi, Jacob; Arnold, Steven M.; Sullivan, Roy M.

    2007-01-01

    Understanding the thermo-mechanical response of the Space Shuttle External Tank spray-on foam insulation (SOFI) material is critical, to NASA's Return to Flight effort. This closed-cell rigid polymeric foam is used to insulate the metallic Space Shuttle External Tank, which is at cryogenic temperatures immediately prior to and during lift off. The shedding of the SOFI during ascent led to the loss of the Columbia, and eliminating/minimizing foam lass from the tank has become a priority for NASA as it seeks to resume scheduled space shuttle missions. Determining the nature of the SOFI material behavior in response to both thermal and mechanical loading plays an important role as any structural modeling of the shedding phenomenon k predicated on knowledge of the constitutive behavior of the foam. In this paper, the SOFI material has been analyzed using the High-Fidelity Generalized Method of Cells (HFGMC) micromechanics model, which has recently been extended to admit a triply-periodic 3-D repeating unit cell (RUC). Additional theoretical extensions that mere made in order to enable modeling of the closed-cell-foam material include the ability to represent internal boundaries within the RUC (to simulated internal pores) and the ability to impose an internal pressure within the simulated pores. This latter extension is crucial as two sources contribute to significant internal pressure changes within the SOFI pores. First, gas trapped in the pores during the spray process will expand or contract due to temperature changes. Second, the pore pressure will increase due to outgassing of water and other species present in the foam skeleton polymer material. With HFGMC's new pore pressure modeling capabilities, a nonlinear pressure change within the simulated pore can be imposed that accounts for both of these sources, in addition to stmdar&-thermal and mechanical loading; The triply-periodic HFGMC micromechanics model described above was implemented within NASA GRC's MAC

  12. Correction: Two intense decades of 19th century whaling precipitated rapid decline of right whales around New Zealand and east Australia.

    PubMed

    Carroll, Emma L; Jackson, Jennifer A; Paton, David; Smith, Tim D

    2014-01-01

    Right whales (Eubalaena spp.) were the focus of worldwide whaling activities from the 16th to the 20th century. During the first part of the 19th century, the southern right whale (E. australis) was heavily exploited on whaling grounds around New Zealand (NZ) and east Australia (EA). Here we build upon previous estimates of the total catch of NZ and EA right whales by improving and combining estimates from four different fisheries. Two fisheries have previously been considered: shore-based whaling in bays and ship-based whaling offshore. These were both improved by comparison with primary sources and the American offshore whaling catch record was improved by using a sample of logbooks to produce a more accurate catch record in terms of location and species composition. Two fisheries had not been previously integrated into the NZ and EA catch series: ship-based whaling in bays and whaling in the 20th century. To investigate the previously unaddressed problem of offshore whalers operating in bays, we identified a subset of vessels likely to be operating in bays and read available extant logbooks. This allowed us to estimate the total likely catch from bay-whaling by offshore whalers from the number of vessels seasons and whales killed per season: it ranged from 2,989 to 4,652 whales. The revised total estimate of 53,000 to 58,000 southern right whales killed is a considerable increase on the previous estimate of 26,000, partly because it applies fishery-specific estimates of struck and loss rates. Over 80% of kills were taken between 1830 and 1849, indicating a brief and intensive fishery that resulted in the commercial extinction of southern right whales in NZ and EA in just two decades. This conforms to the global trend of increasingly intense and destructive southern right whale fisheries over time.

  13. Source parameters of the major historical earthquakes in the Tien-Shan region from the late 19th to the early 20th century.

    NASA Astrophysics Data System (ADS)

    Kulikova, Galina; Krüger, Frank

    2016-04-01

    The Tien-Shan is one of the largest mountain belts in the world. Its deformation is dominated by intermontane basins bounded by active thrust and reverse faulting. The Tien-Shan mountain belt is characterized by a very high rate of seismicity along its margins as well as within the Tien-Shan interior. The study area of the here presented work, the western part of the Tien-Shan region, is currently seismically active with small and moderate sized earthquakes. However, at the end of 19th beginning of 20th century, this region was struck by a remarkable series of large magnitude (M>7) earthquakes, two of them reached magnitude 8. These large earthquakes occurred before the global digital seismic network was installed and therefore were recorded only by analog seismic instruments. The processing of the analog is complicated especially due to the digitization of the records - a very time-consuming and delicate part. Therefore a special set of techniques is developed and modern methods are adapted for the digitized instrumental data analysis. Here presented study evaluates the impact of large magnitude M>7.0 earthquakes, in the Tien-Shan region, on the overall regional tectonics. It also investigates the accuracy of previously estimated source parameters for those earthquakes, which were mainly based on macroseismic observations, and re-estimate them based on the instrumental data. Ten strongest and most interesting historical earthquakes in Tien-Shan region are analyzed with in presented work. With the developed techniques, the source parameters of these major earthquakes are determined and their impact on the regional tectonics was investigated. The large magnitudes of the earthquakes are confirmed by instrumental data. The focal mechanisms of these earthquakes were determined providing evidence for responsible faults or fault systems.

  14. Analysis of reporting quality for oral presentations of observational studies at 19th National Surgical Congress: Proposal for a national evaluation system

    PubMed Central

    Hasbahçeci, Mustafa; Başak, Fatih; Acar, Aylin; Şişik, Abdullah

    2016-01-01

    Objective To compare the quality of oral presentations presented at the 19th National Surgical Congress with a national evaluation system with respect to the applicability of systems, and consistency between systems and reviewers. Material and Methods Fifty randomly selected observational studies, which were blinded for author and institute information, were evaluated by using the Strengthening the Reporting of Observational Studies (STROBE), Timmer Score, and National Evaluation System by two reviewers. Abstract scores, evaluation periods, and compatibility between reviewers were compared for each evaluation system. Abstract scores by three different evaluation systems were regarded as the main outcome. Wilcoxon matched-pairs signed rank and Friedman tests for comparison of scores and times, kappa analysis for compatibility between reviewers, and Spearman correlation for analysis of reviewers based on pairs of evaluation systems were used. Results There was no significant difference between abstract scores for each system (p>0.05). A significant difference for evaluation period of reviewers was detected for each system (p<0.05). Compatibility between reviewers was the highest for the Timmer Score (medium, κ=0.523), and the compatibility for STROBE and National Evaluation System was regarded as acceptable (κ=0.394 and κ=0.354, respectively). Assessment of reviewers for pairs of evaluation systems revealed that scores increased in the same direction with each other significantly (p<0.05). Conclusion The National Evaluation System is an appropriate method for evaluation of conference abstracts due to the consistent results between the referees similarly with the current international evaluation systems and ease of applicability with regard to evaluation period. PMID:28149124

  15. [A mere assistant, in every respect subordinate to the physician. Vicissitudes of emancipating 'heilgymnasten' in the Netherlands in the late 19th century].

    PubMed

    Terlouw, T J

    1994-01-01

    During the eighties of the 19th century several physical education teachers who were engaged in physical therapy activities, so called 'heilgynasten', believed that only a solid organization of serious, educated and well-trained heilgymnasten could bring about a positive change in the situation at hand in the field of physical therapy. On September 1st 1889 the 'Genootschap ter beoefening van de Heilgymnastiek in Nederland' ('Society for practising heilgymnastiek in the Netherlands') was founded. The main aim of its members was to establish a state-exam, a public trainingschool as well as to ensure proper legislation for this 'new' profession. In this paper the focus of attention is on the founding of the 'Genootschap' and the reactions it provoked from organizations and practitioners in the fields of physical education and medicine during the first years of its existance. One could say that at first the 'Genootschap' was tolerated. Several well-known Dutch physicians joined the 'Genootschap' as 'extraordinary-member'. Very soon however, some physicians came to see the activities of this organization as a threat to the process of differentiation and specialization in the field of orthopaedic surgery that had just began. They emphasized that the 'heilgymnasten' who worked relatively independent from physicians in the field of physical therapy had no legal status; in fact they argued that these practitioners were actually breaking the law. A solution to these problems was sought through law-suits against 'heilgymnasten' to ensure that they would only practise physical therapy under supervision of physicians. In a next article the plight of one of the Dutch 'heilgymnasten', Hendrik Soeter, who can be considered as a 'victim' of this strategy, will be discussed in more detail. The Dutch 'heilgymnasten' did finally gain a legal status for their profession, but they had to wait for that untill more than fifty years after the foundation of the 'Genootschap'.

  16. Micromechanical Modeling of Concrete at Early Age

    NASA Astrophysics Data System (ADS)

    Tuleubekov, Kairat

    The focus of this research is a micromechanical characterization of Portland cement concrete at early age (less than 28 days). Concrete's viscoelastic properties change significantly at early age due to solidification of its matrix component. Bazant's solidification theory models concrete as a material solidifying in time. This approach is generalized to a three-dimensional characterization of a composite material with a solidifying matrix and elastic inclusions. An integral constitutive relationship was obtained using a generalized correspondence principle and homogenization techniques for elastic composite materials. In light of this approach, effective creep properties of composite spherical assemblage with an aging matrix are obtained. In addition, the elastic Hashin-Monteiro model is generalized to account for the effect of the interfacial transition zone properties on concrete creep. An effective computational platform was developed to evaluate operator expressions in order to obtain relaxation and creep functions numerically. Through numerical examples, it is shown that triaxial generalization of Bazant's solidification model enables robust and computationally efficient prediction of creep deformations in Portland cement concrete.

  17. Single coil bistable, bidirectional micromechanical actuator

    DOEpatents

    Tabat, Ned; Guckel, Henry

    1998-09-15

    Micromechanical actuators capable of bidirectional and bistable operation can be formed on substrates using lithographic processing techniques. Bistable operation of the microactuator is obtained using a single coil and a magnetic core with a gap. A plunger having two magnetic heads is supported for back and forth linear movement with respect to the gap in the magnetic core, and is spring biased to a neutral position in which the two heads are on each side of the gap in the core. The single electrical coil is coupled to the core and is provided with electrical current to attract one of the heads toward the core by reluctance action to drive the plunger to a limit of travel in one direction. The current is then cut off and the plunger returns by spring action toward the gap, whereafter the current is reapplied to the coil to attract the other head of the plunger by reluctance action to drive the plunger to its other limit of travel. This process can be repeated at a time when switching of the actuator is required.

  18. Multiwell micromechanical cantilever array reader for biotechnology

    NASA Astrophysics Data System (ADS)

    Zhang, R.; Best, A.; Berger, R.; Cherian, S.; Lorenzoni, S.; Macis, E.; Raiteri, R.; Cain, R.

    2007-08-01

    We use a multiwell micromechanical cantilever sensor (MCS) device to measure surface stress changes induced by specific adsorption of molecules. A multiplexed assay format facilitates the monitoring of the bending of 16 MCSs in parallel. The 16 MCSs are grouped within four separate wells. Each well can be addressed independently by different analyte liquids. This enables functionalization of MCS separately by flowing different solutions through each well. In addition, each well contains a fixed reference mirror which allows measuring the absolute bending of MCS. In addition, the mirror can be used to follow refractive index changes upon mixing of different solutions. The effect of the flow rate on the MCS bending change was found to be dependent on the absolute bending value of MCS. Experiments and finite element simulations of solution exchange in wells were performed. Both revealed that one solution can be exchanged by another one after 200μl volume has flown through. Using this device, the adsorption of thiolated DNA molecules and 6-mercapto-1-hexanol on gold surfaces was performed to test the nanomechanical response of MCS.

  19. Bio-Inspired Micromechanical Directional Acoustic Sensor

    NASA Astrophysics Data System (ADS)

    Swan, William; Alves, Fabio; Karunasiri, Gamani

    Conventional directional sound sensors employ an array of spatially separated microphones and the direction is determined using arrival times and amplitudes. In nature, insects such as the Ormia ochracea fly can determine the direction of sound using a hearing organ much smaller than the wavelength of sound it detects. The fly's eardrums are mechanically coupled, only separated by about 1 mm, and have remarkable directional sensitivity. A micromechanical sensor based on the fly's hearing system was designed and fabricated on a silicon on insulator (SOI) substrate using MEMS technology. The sensor consists of two 1 mm2 wings connected using a bridge and to the substrate using two torsional legs. The dimensions of the sensor and material stiffness determine the frequency response of the sensor. The vibration of the wings in response to incident sound at the bending resonance was measured using a laser vibrometer and found to be about 1 μm/Pa. The electronic response of the sensor to sound was measured using integrated comb finger capacitors and found to be about 25 V/Pa. The fabricated sensors showed good directional sensitivity. In this talk, the design, fabrication and characteristics of the directional sound sensor will be described. Supported by ONR and TDSI.

  20. Micromechanical structures and microelectronics for acceleration sensing

    NASA Astrophysics Data System (ADS)

    Davies, Brady R.; Montague, Stephen; Smith, James H.; Lemkin, Mark

    1997-09-01

    MEMS is an enabling technology that may provide low-cost devices capable of sensing motion in a reliable and accurate manner. This paper describes work in MEMS accelerometer development at Sandia National Laboratories. This work leverages a process for integrating both the micromechanical structures and microelectronics circuitry of a MEMS accelerometer on the same chip. The design and test results of an integrated MEMS high-g accelerometer will be detailed. Additionally a design for a high-g fuse component (low-G or approximately equals 25 G accelerometer) will be discussed in the paper (where 1 G approximately equals 9.81 m/s). In particular, a design team at Sandia was assembled to develop a new micromachined silicon accelerometer which would be capable of surviving and measuring high-g shocks. Such a sensor is designed to be cheaper and more reliable than currently available sensors. A promising design for a suspended plate mass sensor was developed and the details of that design along with test data will be documented in the paper. Future development in this area at Sandia will focus on implementing accelerometers capable of measuring 200 kilo-g accelerations. Accelerometer development at Sandia will also focus on multi-axis acceleration measurement with integrated microelectronics.

  1. Advanced micromechanisms in a multilevel polysilicon technology

    NASA Astrophysics Data System (ADS)

    Rodgers, M. Steven; Sniegowski, Jeffry J.; Miller, Samuel L.; Craig Barron, Carole; McWhorter, Paul J.

    1997-09-01

    Quad-level polysilicon surface micromachining technology, comprising three mechanical levels plus an electrical interconnect layer, is giving rise to a new generation of micro-electromechanical devices and assemblies. Enhanced components can now be produced through greater flexibility in fabrication and design. New levels of design complexity that include multi-level gears, single-attempt locks, and optical elements have recently been realized. Extensive utilization of the fourth layer of polysilicon differentiates these latter generation devices from their predecessors. This level of poly enables the fabrication of pin joints, linkage arms, hinges on moveable plates, and multi-level gear assemblies. The mechanical design aspects of these latest micromachines will be discussed with particular emphasis on a number of design modifications that improve the power, reliability, and smoothness of operation of the microengine. The microengine is the primary actuation mechanism that is being used to drive mirrors out of plane and rotate 1600-micrometers diameter gears. Also discussed is our most advanced micromechanical system to date, a complex proof-of-concept batch-fabricated assembly that, upon transmitting the proper electrical code to a mechanical lock, permits the operation of a micro-optical shutter.

  2. Frequency division using a micromechanical resonance cascade

    NASA Astrophysics Data System (ADS)

    Qalandar, K. R.; Strachan, B. S.; Gibson, B.; Sharma, M.; Ma, A.; Shaw, S. W.; Turner, K. L.

    2014-12-01

    A coupled micromechanical resonator array demonstrates a mechanical realization of multi-stage frequency division. The mechanical structure consists of a set of N sequentially perpendicular microbeams that are connected by relatively weak elastic elements such that the system vibration modes are localized to individual microbeams and have natural frequencies with ratios close to 1:2:⋯:2N. Conservative (passive) nonlinear inter-modal coupling provides the required energy transfer between modes and is achieved by finite deformation kinematics. When the highest frequency beam is excited, this arrangement promotes a cascade of subharmonic resonances that achieve frequency division of 2j at microbeam j for j = 1, …, N. Results are shown for a capacitively driven three-stage divider in which an input signal of 824 kHz is passively divided through three modal stages, producing signals at 412 kHz, 206 kHz, and 103 kHz. The system modes are characterized and used to delineate the range of AC input voltages and frequencies over which the cascade occurs. This narrow band frequency divider has simple design rules that are scalable to higher frequencies and can be extended to a larger number of modal stages.

  3. Contact micromechanics in granular media with clay

    SciTech Connect

    Ita, Stacey Leigh

    1994-08-01

    Many granular materials, including sedimentary rocks and soils, contain clay particles in the pores, grain contacts, or matrix. The amount and location of the clays and fluids can influence the mechanical and hydraulic properties of the granular material. This research investigated the mechanical effects of clay at grain-to-grain contacts in the presence of different fluids. Laboratory seismic wave propagation tests were conducted at ultrasonic frequencies using spherical glass beads coated with Montmorillonite clay (SWy-1) onto which different fluids were adsorbed. For all bead samples, seismic velocity increased and attenuation decreased as the contact stiffnesses increased with increasing stress demonstrating that grain contacts control seismic transmission in poorly consolidated and unconsolidated granular material. Coating the beads with clay added stiffness and introduced viscosity to the mechanical contact properties that increased the velocity and attenuation of the propagating seismic wave. Clay-fluid interactions were studied by allowing the clay coating to absorb water, ethyl alcohol, and hexadecane. Increasing water amounts initially increased seismic attenuation due to clay swelling at the contacts. Attenuation decreased for higher water amounts where the clay exceeded the plastic limit and was forced from the contact areas into the surrounding open pore space during sample consolidation. This work investigates how clay located at grain contacts affects the micromechanical, particularly seismic, behavior of granular materials. The need for this work is shown by a review of the effects of clays on seismic wave propagation, laboratory measurements of attenuation in granular media, and proposed mechanisms for attenuation in granular media.

  4. Micromechanics of brittle creep in rocks

    NASA Astrophysics Data System (ADS)

    Brantut, N.; Baud, P.; Heap, M. J.; Meredith, P. G.

    2012-08-01

    In the upper crust, the chemical influence of pore water promotes time dependent brittle deformation through sub-critical crack growth. Sub-critical crack growth allows rocks to deform and fail at stresses well below their short-term failure strength, and even at constant applied stress (“brittle creep”). Here we provide a micromechanical model describing time dependent brittle creep of water-saturated rocks under triaxial stress conditions. Macroscopic brittle creep is modeled on the basis of microcrack extension under compressive stresses due to sub-critical crack growth. The incremental strains due to the growth of cracks in compression are derived from the sliding wing crack model of Ashby and Sammis (1990), and the crack length evolution is computed from Charles' law. The macroscopic strains and strain rates computed from the model are non linear, and compare well with experimental results obtained on granite, low porosity sandstone and basalt rock samples. Primary creep (decelerating strain) corresponds to decelerating crack growth, due to an initial decrease in stress intensity factor with increasing crack length in compression. Tertiary creep (accelerating strain as failure is approached) corresponds to an increase in crack growth rate due to crack interactions. Secondary creep with apparently constant strain rate arises as an inflexion between those two end-member phases. The minimum strain rate at the inflexion point can be estimated analytically as a function of model parameters, effective confining pressure and temperature, which provides an approximate creep law for the process. The creep law is used to infer the long term strain rate as a function of depth in the upper crust due to the action of the applied stresses: in this way, sub-critical cracking reduces the failure stress in a manner equivalent to a decrease in cohesion. We also investigate the competition with pressure solution in porous rocks, and show that the transition from sub

  5. Composite micromechanical modeling using the boundary element method

    NASA Technical Reports Server (NTRS)

    Goldberg, Robert K.; Hopkins, Dale A.

    1993-01-01

    The use of the boundary element method for analyzing composite micromechanical behavior is demonstrated. Stress-strain, heat conduction, and thermal expansion analyses are conducted using the boundary element computer code BEST-CMS, and the results obtained are compared to experimental observations, analytical calculations, and finite element analyses. For each of the analysis types, the boundary element results agree reasonably well with the results from the other methodologies, with explainable discrepancies. Overall, the boundary element method shows promise in providing an alternative method to analyze composite micromechanical behavior.

  6. The Visual Difficulties of Selected Artists and Limitations of Ophthalmological Care During The 19th and Early 20th Centuries (An AOS Thesis)

    PubMed Central

    Ravin, James G.

    2008-01-01

    Purpose To investigate the effects of eye diseases on several important artists who have been given little attention from a medical-historical viewpoint. The examples chosen demonstrate problems artists have had to face from different types of eye disease, including cataract, glaucoma, and retinal diseases. The ophthalmological care provided is described in terms of scientific knowledge at the time. Methods Investigation of primary and secondary source material. Discussion with art historians and ophthalmic historians. Examination of work by the artists. Results Artists can be markedly affected by ocular diseases that change their ability to see the world. The individuals described here worked during the 19th century and first half of the 20th century. Homer Martin suffered from cataracts, and his works reveal changes in details and color as he aged. Henri Harpignies, who had an extremely long career, undoubtedly had cataracts and may also have had macular degeneration. Angle-closure glaucoma blinded Jules Chéret. Auguste Ravier suffered from neovascular glaucoma in one eye and was able to work with his remaining eye, which developed a cataract. Louis Valtat suffered from what was in all likelihood open-angle glaucoma, but specific changes due to this disease are not apparent in his work. Roger Bissière developed glaucoma and did well following filtration surgery. George Du Maurier lost one eye from what was probably a retinal detachment and later suffered from a central retinal problem in the other eye. Conclusions Diseases of the eye may profoundly influence artists by altering their perception of the world. The specific effects may vary, depending on the disease, its severity, and the psychology of the artist. Cataracts typically affect an artist’s ability to depict color and detail. The effect of glaucoma generally depends on whether central vision is preserved. Disease that affects the center of the retina has a substantial effect on an artist’s ability

  7. North Atlantic influence on 19th-20th century rainfall in the Dead Sea watershed, teleconnections with the Sahel, and implication for Holocene climate fluctuations

    NASA Astrophysics Data System (ADS)

    Kushnir, Yochanan; Stein, Mordechai

    2010-12-01

    The importance of understanding processes that govern the hydroclimate of the Mediterranean Basin is highlighted by the projected significant drying of the region in response to the increase in greenhouse gas concentrations. Here we study the long-term hydroclimatic variability of the central Levant region, situated in the eastern boundary of the Basin, as reveled by instrumental observations and the Holocene record of Dead Sea level variations. Observations of 19th and 20th century precipitation in the Dead Sea watershed region display a multidecadal, anti-phase relationship to North Atlantic (NAtl) sea surface temperature (SST) variability, such that when the NAtl is relatively cold, Jerusalem experiences higher than normal precipitation and vice versa. This association is underlined by a negative correlation to precipitation in the sub-Saharan Sahel and a positive correlation to precipitation in western North America, areas that are also affected by multidecadal NAtl SST variability. These observations are consistent with a broad range of Holocene hydroclimatic fluctuations from the epochal, to the millennial and centennial time scales, as displayed by the Dead Sea lake level, by lake levels in the Sahel, and by direct and indirect proxy indicators of NAtl SSTs. On the epochal time scale, the gradual cooling of NAtl SSTs throughout the Holocene in response to precession-driven reduction of summer insolation is associated with previously well-studied wet-to-dry transition in the Sahel and with a general increase in Dead Sea lake levels from low stands after the Younger Dryas to higher stands in the mid- to late-Holocene. On the millennial and centennial time scales there is also evidence for an anti-phase relationship between Holocene variations in the Dead Sea and Sahelian lake levels and with proxy indicators of NAtl SSTs. However the records are punctuated by abrupt lake-level drops, which appear to be in-phase and which occur during previously documented

  8. A model for the 19th century eruption of Eta Carinae: CSM interaction like a scaled-down Type IIn Supernova

    NASA Astrophysics Data System (ADS)

    Smith, Nathan

    2013-03-01

    This paper proposes a simple model for the 19th century eruption of Eta Carinae that consists of two components: (1) a strong wind (dot{M}=0.33 M_{{odot }} yr-1; v∞ = 200 km s-1), blowing for 30 yr, followed by (2) a 1050 erg explosion (10 M⊙; 750-1000 km s-1) occurring in 1844. The ensuing collision between the fast ejecta and the dense circumstellar material (CSM) causes an increase in brightness observed at the end of 1844, followed by a sustained high-luminosity phase lasting for 10-15 yr that provides a close match to the observed historical light curve. The emergent luminosity is powered by converting kinetic energy to radiation through CSM interaction, analogous to the process occurring in more luminous Type IIn supernovae, except with ˜10 times lower explosion energy and at slower speeds (causing a longer duration and lower emergent luminosity). We demonstrate that such an explosive event not only provides a natural explanation for the light-curve evolution, but also accounts for a number of puzzling attributes of the highly scrutinized Homunculus, including: (1) rough equipartition of total radiated and kinetic energy in the event, (2) the double-shell structure of the Homunculus, with a thin massive outer shell (corresponding to the coasting cold dense shell) and a thicker inner layer (between the cold dense shell and the reverse shock), (3) the apparent single age and Hubble-like flow of the Homunculus resulting from the thin swept-up shell, (4) the complex mottled appearance of the polar lobes in Hubble Space Telescope images, arising naturally from Raleigh-Taylor or Vishniac instabilities at the contact discontinuity of the shock, (5) efficient and rapid dust formation, which has been observed in the post-shock zones of Type IIn supernovae, and (6) the fast (3000-5000 km s-1) material outside the Homunculus, arising from the acceleration of the forward shock upon exiting the dense CSM. In principle, the bipolar shape could be explained borrowing

  9. The Influence of The Geological and Geomorphological Settings On The Shallow Landslides Triggered During The 19th June, 1996 Heavy Rainfalls In Southern Apuan Alps (italy)

    NASA Astrophysics Data System (ADS)

    D'Amato Avanzi, G.; Giannecchini, R.; Puccinelli, A.

    On June the 19th, 1996 many disastrous shallow landslides (nearly 700) occurred in the southern Apuan Alps (Tuscany, Italy) as a consequence of an exceptionally heavy rainstorm (474 mm/12 hours). Here, the results of the studies on the landslides oc- curred in the most severely damaged basins (Cardoso, Mulina and Turrite di Galli- cano torrents) are summarized. The most significant parameters of the landslides were analysed, to identify the factors which most influenced their activation. Moreover, the total amount of mobilized material was estimated. The most common type of landslide movement was complex, from very to extremely rapid, debris slide-debris flow, with a high length to breadth ratio. Most of them were probably first time landslides; ca. 90% of them involved the colluvium cover of slopes. The studies in the landslide sites also highlighted many geomorphically and geologically recurrent factors, summarized be- low. 85% of landslides occurred on rather steep slopes (30-45), in first-order basins and hollows. In these situations, the concave geometry of the colluvium/bedrock inter- face favoured the convergence of groundwater flow and the build-up of pore pressure, leading to failure. In landslide sites, a concave shape of the surface and a rectilinear profile of the slope were a frequent feature. The bedrock of landslide sites was gener- ally made up of impervious or scarcely pervious rocks. In many cases, the presence of a main discontinuity in the bedrock (bedding or schistosity) dipping downslope was significant. The total surface involved in landslides of June 19, 1996 was estimated at ca. 1 Km2, 2.2% of the basins surface. More than 80% of this surface was covered by chestnut trees: thus, ca. 7,000 chestnut trees were uprooted by the landslides and fell into the riverbeds. This significantly contributed to the extensive destruction and blockage of bridge spans. The total volume of mobilized material was estimated at ca. 1,350,000 m3: most of this

  10. Electronic Transfer of Information and Its Impact on Aerospace and Defence Research and Development. Proceedings of the Technical Information Panel Specialists’ Meeting Held in Brussels, Belgium on 17th-19th October 1989 Abstracts.

    DTIC Science & Technology

    1990-01-01

    INTRODUCTION 1 SUMMARIES OF PAPERS AND DISCUSSIONS COMMENTS ON TECHNOLOGIES 13 RECOMMENDATIONS 15 p fl ton for DTIK TAs Ummnonn e a hJatirtca~io S...was heid from 17th- 19th October 1989 in Brussels, Belgium; and comments on the state of the art of the technologies presented, discusses their possible...introduction into scientific and technical organisations, and provides recommendations on the use of technologies with emphasis on the aerospace and

  11. Design and Implementation of a Micromechanical Silicon Resonant Accelerometer

    PubMed Central

    Huang, Libin; Yang, Hui; Gao, Yang; Zhao, Liye; Liang, Jinxing

    2013-01-01

    The micromechanical silicon resonant accelerometer has attracted considerable attention in the research and development of high-precision MEMS accelerometers because of its output of quasi-digital signals, high sensitivity, high resolution, wide dynamic range, anti-interference capacity and good stability. Because of the mismatching thermal expansion coefficients of silicon and glass, the micromechanical silicon resonant accelerometer based on the Silicon on Glass (SOG) technique is deeply affected by the temperature during the fabrication, packaging and use processes. The thermal stress caused by temperature changes directly affects the frequency output of the accelerometer. Based on the working principle of the micromechanical resonant accelerometer, a special accelerometer structure that reduces the temperature influence on the accelerometer is designed. The accelerometer can greatly reduce the thermal stress caused by high temperatures in the process of fabrication and packaging. Currently, the closed-loop drive circuit is devised based on a phase-locked loop. The unloaded resonant frequencies of the prototype of the micromechanical silicon resonant accelerometer are approximately 31.4 kHz and 31.5 kHz. The scale factor is 66.24003 Hz/g. The scale factor stability is 14.886 ppm, the scale factor repeatability is 23 ppm, the bias stability is 23 μg, the bias repeatability is 170 μg, and the bias temperature coefficient is 0.0734 Hz/°C. PMID:24256978

  12. Single crystal micromechanical resonator and fabrication methods thereof

    DOEpatents

    Olsson, Roy H.; Friedmann, Thomas A.; Homeijer, Sara Jensen; Wiwi, Michael; Hattar, Khalid Mikhiel; Clark, Blythe; Bauer, Todd; Van Deusen, Stuart B.

    2016-12-20

    The present invention relates to a single crystal micromechanical resonator. In particular, the resonator includes a lithium niobate or lithium tantalate suspended plate. Also provided are improved microfabrication methods of making resonators, which does not rely on complicated wafer bonding, layer fracturing, and mechanical polishing steps. Rather, the methods allow the resonator and its components to be formed from a single crystal.

  13. Micromechanics Analysis Code (MAC). User Guide: Version 2.0

    NASA Technical Reports Server (NTRS)

    Wilt, T. E.; Arnold, S. M.

    1996-01-01

    The ability to accurately predict the thermomechanical deformation response of advanced composite materials continues to play an important role in the development of these strategic materials. Analytical models that predict the effective behavior of composites are used not only by engineers performing structural analysis of large-scale composite components but also by material scientists in developing new material systems. For an analytical model to fulfill these two distinct functions it must be based on a micromechanics approach which utilizes physically based deformation and life constitutive models and allows one to generate the average (macro) response of a composite material given the properties of the individual constituents and their geometric arrangement. Here the user guide for the recently developed, computationally efficient and comprehensive micromechanics analysis code's (MAC) who's predictive capability rests entirely upon the fully analytical generalized method of cells (GMC), micromechanics model is described. MAC is a versatile form of research software that 'drives' the double or triply periodic micromechanics constitutive models based upon GMC. MAC enhances the basic capabilities of GMC by providing a modular framework wherein (1) various thermal, mechanical (stress or strain control) and thermomechanical load histories can be imposed, (2) different integration algorithms may be selected, (3) a variety of constituent constitutive models may be utilized and/or implemented, and (4) a variety of fiber and laminate architectures may be easily accessed through their corresponding representative volume elements.

  14. Experimental Micromechanics Study of Lamellar TiA1

    DTIC Science & Technology

    2007-02-15

    of the 2005 SEM Annual Conference & Exposition, Portland, OR USA, June 7-9, 2005 "Brazilian Tests in Lamellar TiAr ", F.P. Chiang, Y. Ding, A.Ho, A.H...Experimental Mechanics, July 1-6, Alexandroupolis, Greece, 2007 "Experimental Micromechanics Study of Lamellar TiAr ", Fu-pen Chiang, Gunes Uzer, Andrew H

  15. Micromechanics Analysis Code (MAC) User Guide: Version 1.0

    NASA Technical Reports Server (NTRS)

    Wilt, T. E.; Arnold, S. M.

    1994-01-01

    The ability to accurately predict the thermomechanical deformation response of advanced composite materials continues to play an important role in the development of these strategic materials. Analytical models that predict the effective behavior of composites are used not only by engineers performing structural analysis of large-scale composite components but also by material scientists in developing new material systems. For an analytical model to fulfill these two distinct functions it must be based on a micromechanics approach which utilizes physically based deformation and life constitutive models and allows one to generate the average (macro) response of a composite material given the properties of the individual constituents and their geometric arrangement. Here the user guide for the recently developed, computationally efficient and comprehensive micromechanics analysis code, MAC, who's predictive capability rests entirely upon the fully analytical generalized method of cells, GMC, micromechanics model is described. MAC is a versatile form of research software that 'drives' the double or triple ply periodic micromechanics constitutive models based upon GMC. MAC enhances the basic capabilities of GMC by providing a modular framework wherein (1) various thermal, mechanical (stress or strain control), and thermomechanical load histories can be imposed; (2) different integration algorithms may be selected; (3) a variety of constituent constitutive models may be utilized and/or implemented; and (4) a variety of fiber architectures may be easily accessed through their corresponding representative volume elements.

  16. Micromechanical Aspects of Hydraulic Fracturing Processes

    NASA Astrophysics Data System (ADS)

    Galindo-torres, S. A.; Behraftar, S.; Scheuermann, A.; Li, L.; Williams, D.

    2014-12-01

    A micromechanical model is developed to simulate the hydraulic fracturing process. The model comprises two key components. Firstly, the solid matrix, assumed as a rock mass with pre-fabricated cracks, is represented by an array of bonded particles simulated by the Discrete Element Model (DEM)[1]. The interaction is ruled by the spheropolyhedra method, which was introduced by the authors previously and has been shown to realistically represent many of the features found in fracturing and communition processes. The second component is the fluid, which is modelled by the Lattice Boltzmann Method (LBM). It was recently coupled with the spheropolyhedra by the authors and validated. An advantage of this coupled LBM-DEM model is the control of many of the parameters of the fracturing fluid, such as its viscosity and the injection rate. To the best of the authors' knowledge this is the first application of such a coupled scheme for studying hydraulic fracturing[2]. In this first implementation, results are presented for a two-dimensional situation. Fig. 1 shows one snapshot of the LBM-DEM coupled simulation for the hydraulic fracturing where the elements with broken bonds can be identified and the fracture geometry quantified. The simulation involves a variation of the underground stress, particularly the difference between the two principal components of the stress tensor, to explore the effect on the fracture path. A second study focuses on the fluid viscosity to examine the effect of the time scales of different injection plans on the fracture geometry. The developed tool and the presented results have important implications for future studies of the hydraulic fracturing process and technology. references 1. Galindo-Torres, S.A., et al., Breaking processes in three-dimensional bonded granular materials with general shapes. Computer Physics Communications, 2012. 183(2): p. 266-277. 2. Galindo-Torres, S.A., A coupled Discrete Element Lattice Boltzmann Method for the

  17. [Comparison of medical practices of 'massage' and 'gymnastics' - at the end of the 19th and the beginning of the 20th century (England, France, Germany, Switzerland)].

    PubMed

    Quin, Grégory

    2014-01-01

    Massage and medical gymnastics are very ancient form of medical practices and knowledge, nevertheless they seem to focus a growing attention between 1860 and World War I in Europe. These practices know a quick institutionalization, and the physiotherapy or "kinesitherapy" emerge as a discipline with some more structured training course for students and future practitioners. In fact, the determinants of this development are numerous, specialization, professionalization, cultural transfer, and more broadly with geopolitical influences and nationalist feelings, influence of the Swedish gymnastics.

  18. Geodiversity and biodiversity interactions in the sand landscapes of the Netherlands on 19th and early 20th century landscape paintings

    NASA Astrophysics Data System (ADS)

    Jungerius, Pieter; van den Ancker, Hanneke

    2014-05-01

    Sand landscapes occupy about half of the territory of the Netherlands. Apart from an insignificant amount of Tertiary deposits, these sands are of Pleistocene and Holocene age. They include Saalian push moraines, Weichselian cover sands and Holocene drift sands. To these geological landscapes, cultural variants should be added such as the essen, i.e. a landscape with plaggen soils, and reclaimed lands (e.g. former moors). Not included are the coastal sands, which we dealt with in an earlier EGU contribution (van den Ancker & Jungerius 2012). Nature and man created a wide variety of sceneries that inspired painters in the 19th and early 20th century (Jungerius et al. 2012). Painter communities on the sandy soils flourished in Oosterbeek/Wolfheze, Laren/Blaricum, Nijkerk, Nunspeet/Elspeet, Hattem and Heeze. Many of the landscape paintings are found in the database of Simonis en Buunk that can be freely consulted on line (http//www.simonis&buunk.com). For this presentation we selected specimens that show geodiversity-biodiversity relationships, some of which have changed since. Painters of push moraines were attracted by the rolling terrain, the dry valleys and occasionally the colourful podzol soil profiles. Popular themes in the cover sands were the undulating relief and heathlands with herds of sheep, sandy footpaths and country roads with erosion phenomena. The dynamics of erosion captivated the painters of Holocene drift sand scenery, as did the bare fields of cultivated lands. Their paintings show the rural areas that since the beginning of the 20th century lost their traditional charm in large-scale re-allotment schemes and artificial nature-building project, that changed geodiversity-biodiversity relationships. Changes in the sandy terrains that can be inferred from the paintings are on a landscape scale, the scale of the landform and vegetation type, and are illustrated by changes in colour, pattern, structure and texture. Examples are: · active drift sands

  19. Micromechanical properties of veneer luting resins after curing through ceramics.

    PubMed

    Oztürk, Elif; Hickel, Reinhard; Bolay, Sükran; Ilie, Nicoleta

    2012-02-01

    The aim of this study was to assess the performance of light-cured luting resin after curing under the ceramic restoration in comparison to dual-cured luting resin, by evaluating the micromechanical properties. Two hundred seventy thin luting composite films of ca. 170 μm in thickness were prepared by using two light-cured luting resins (Variolink Veneer, Ivoclar Vivadent; RelyX Veneer, 3M ESPE) and a dual-cured luting resin (Variolink II, Ivoclar Vivadent). The composites were cured by using a LED-unit (Bluephase®, Ivoclar Vivadent) with three different curing times (10, 20, and 30 s) under two ceramics (IPS e.max Press, Ivoclar Vivadent; IPS Empress® CAD, Ivoclar Vivadent) of different thicknesses (0, 0.75, and 2 mm). Forty-five groups were included, each containing six thin films. The samples were stored after curing for 24 h at 37°C by maintaining moisture conditions with distilled water. Micromechanical properties of the composites were measured with an automatic microhardness indenter (Fisherscope H100C, Germany). For each sample, ten indentations were made, thus totalizing 60 measurements per group. Micromechanical properties of the luting resins were statistically analyzed (SPSS 17.0). Significant differences were observed between the micromechanical properties of the luting resins (p < 0.05). Variolink II showed the highest values in modulus of elasticity (E = 11 ± 0.5)* and Vickers hardness (HV = 48.2 ± 3.2)* and the lowest values in creep (Cr = 4.3 ± 0.1)* and elastic-plastic deformation (We/Wtot = 38.6 ± 0.7)* followed by RelyX Veneer (E = 6.9 ± 0.3, HV = 33 ± 2.5, Cr = 4.6 ± 0.2, We/Wtot = 41.8 ± 1.0)* and Variolink Veneer (E = 4.4 ± 0.4, HV = 20.1 ± 2.6, Cr = 5 ± 0.2, We/Wtot = 43.7 ± 1.3)*. Dual-cured luting resin expressed higher values in the micro-mechanical properties compared to the light-cured luting resins. The effect of luting resin type on the micromechanical properties of the luting resins was higher than the effect of

  20. Climate-driven introduction of the Black Death and successive plague reintroductions into Europe.

    PubMed

    Schmid, Boris V; Büntgen, Ulf; Easterday, W Ryan; Ginzler, Christian; Walløe, Lars; Bramanti, Barbara; Stenseth, Nils Chr

    2015-03-10

    The Black Death, originating in Asia, arrived in the Mediterranean harbors of Europe in 1347 CE, via the land and sea trade routes of the ancient Silk Road system. This epidemic marked the start of the second plague pandemic, which lasted in Europe until the early 19th century. This pandemic is generally understood as the consequence of a singular introduction of Yersinia pestis, after which the disease established itself in European rodents over four centuries. To locate these putative plague reservoirs, we studied the climate fluctuations that preceded regional plague epidemics, based on a dataset of 7,711 georeferenced historical plague outbreaks and 15 annually resolved tree-ring records from Europe and Asia. We provide evidence for repeated climate-driven reintroductions of the bacterium into European harbors from reservoirs in Asia, with a delay of 15 ± 1 y. Our analysis finds no support for the existence of permanent plague reservoirs in medieval Europe.

  1. Climate-driven introduction of the Black Death and successive plague reintroductions into Europe

    PubMed Central

    Büntgen, Ulf; Easterday, W. Ryan; Ginzler, Christian; Walløe, Lars; Bramanti, Barbara; Stenseth, Nils Chr.

    2015-01-01

    The Black Death, originating in Asia, arrived in the Mediterranean harbors of Europe in 1347 CE, via the land and sea trade routes of the ancient Silk Road system. This epidemic marked the start of the second plague pandemic, which lasted in Europe until the early 19th century. This pandemic is generally understood as the consequence of a singular introduction of Yersinia pestis, after which the disease established itself in European rodents over four centuries. To locate these putative plague reservoirs, we studied the climate fluctuations that preceded regional plague epidemics, based on a dataset of 7,711 georeferenced historical plague outbreaks and 15 annually resolved tree-ring records from Europe and Asia. We provide evidence for repeated climate-driven reintroductions of the bacterium into European harbors from reservoirs in Asia, with a delay of 15 ± 1 y. Our analysis finds no support for the existence of permanent plague reservoirs in medieval Europe. PMID:25713390

  2. Assessment of soil-gas, soil, and water contamination at the former 19th Street landfill, Fort Gordon, Georgia, 2009-2010

    USGS Publications Warehouse

    Falls, W. Fred; Caldwell, Andral W.; Guimaraes, Wladmir B.; Ratliff, W. Hagan; Wellborn, John B.; Landmeyer, James E.

    2011-01-01

    Soil gas, soil, and water were assessed for organic and inorganic constituents at the former 19th Street landfill at Fort Gordon, Georgia, from February to September 2010. Passive soil-gas samplers were analyzed to evaluate organic constituents in the hyporheic zone and flood plain of a creek and soil gas within the estimated boundaries of the former landfill. Soil and water samples were analyzed to evaluate inorganic constituents in soil samples, and organic and inorganic constituents in the surface water of a creek adjacent to the landfill, respectively. This assessment was conducted to provide environmental constituent data to Fort Gordon pursuant to requirements of the Resource Conservation and Recovery Act Part B Hazardous Waste Permit process. The passive soil-gas samplers deployed in the water-saturated hyporheic zone and flood plain of the creek adjacent to the former landfill indicated the presence of total petroleum hydrocarbon (TPH) and octane above method detection levels in groundwater beneath the creek bed and flood plain at all 12 soil-gas sampler locations. The TPH concentrations ranged from 51.4 to 81.4 micrograms per liter. Octane concentrations ranged from 1.78 to 2.63 micrograms per liter. These detections do not clearly identify specific source areas in the former landfill; moreover, detections of TPH and octane in a soil-gas sampler installed at a seep on the western bank of the creek indicated the potential for these constituents to be derived from source areas outside the estimated boundaries of the former landfill. A passive soil-gas sampler survey was conducted in the former landfill from June 30 to July 5, 2010, and involved 56 soil-gas samplers that were analyzed for petroleum and halogenated compounds not classified as chemical agents or explosives. The TPH soil-gas mass exceeded 2.0 micrograms in 21 samplers. Most noticeable are the two sites with TPH detections which are located in and near the hyporheic zone and are likely to affect

  3. Electromagnetic and nuclear radiation detector using micromechanical sensors

    DOEpatents

    Thundat, Thomas G.; Warmack, Robert J.; Wachter, Eric A.

    2000-01-01

    Electromagnetic and nuclear radiation is detected by micromechanical sensors that can be coated with various interactive materials. As the micromechanical sensors absorb radiation, the sensors bend and/or undergo a shift in resonance characteristics. The bending and resonance changes are detected with high sensitivity by any of several detection methods including optical, capacitive, and piezoresistive methods. Wide bands of the electromagnetic spectrum can be imaged with picoJoule sensitivity, and specific absorptive coatings can be used for selective sensitivity in specific wavelength bands. Microcantilevers coated with optical cross-linking polymers are useful as integrating optical radiation dosimeters. Nuclear radiation dosimetry is possible by fabricating cantilevers from materials that are sensitive to various nuclear particles or radiation. Upon exposure to radiation, the cantilever bends due to stress and its resonance frequency shifts due to changes in elastic properties, based on cantilever shape and properties of the coating.

  4. Using dissipative particle dynamics to model micromechanics of responsive hydrogels

    NASA Astrophysics Data System (ADS)

    Alexeev, Alexander; Nikolov, Svetoslav; Fernandez de Las Nieves, Alberto

    2015-03-01

    The ability of responsive hydrogels to undergo complex and reversible shape transformations in response to external stimuli such as temperature, magnetic/electric fields, pH levels, and light intensity has made them the material of choice for tissue scaffolding, drug delivery, bio-adhesive, bio-sensing, and micro-sorting applications. The complex micromechanics and kinetics of these responsive networks however, currently hinders developments in the aforementioned areas. In order to better understand the mechanical properties of these systems and how they change during the volume transition we have developed a dissipative particle dynamics (DPD) model for responsive polymer networks. We use this model to examine the impact of the Flory-Huggins parameter on the bulk and shear moduli. In this fashion we evaluate how environmental factors can affect the micromechanical properties of these networks. Support from NSF CAREER Award (DMR-1255288) is gratefully acknowledged.

  5. Design of a fully compliant bistable micromechanism for switching devices

    NASA Astrophysics Data System (ADS)

    Chang, Hsin-An; Tsay, Jinni; Sung, Cheng-Kuo

    2001-11-01

    This paper proposes a design of a bistable micromechanism for the application of switching devices. The topology of a fully compliant four-bar mechanism is adopted herein. The central mass of the mechanism is employed as a carriage to carry switching components, such as mirror, electrical contact, etc. The equations that predict the existence of bistable states, the extreme positions of the motion range and the maximum stress states of members were derived. MUMPs provided by Cronos Integrated Microsystems fabricated the proposed micromechanisms for the purpose of verifying the theoretical predictions. Finally, an experimental rig was established. The bistable mechanisms were switched either by the probe or actuators to push the central mass. The experimental results demonstrated that the motions observed approximately met the predicted values.

  6. Frequency stability improvement for piezoresistive micromechanical oscillators via synchronization

    NASA Astrophysics Data System (ADS)

    Pu, Dong; Huan, Ronghua; Wei, Xueyong

    2017-03-01

    Synchronization phenomenon first discovered in Huygens' clock shows that the rhythms of oscillating objects can be adjusted via an interaction. Here we show that the frequency stability of a piezoresistive micromechanical oscillator can be enhanced via synchronization. The micromechanical clamped-clamped beam oscillator is built up using the electrostatic driving and piezoresistive sensing technique and the synchronization phenomenon is observed after coupling it to an external oscillator. An enhancement of frequency stability is obtained in the synchronization state. The influences of the synchronizing perturbation intensity and frequency detuning applied on the oscillator are studied experimentally. A theoretical analysis of phase noise leads to an analytical formula for predicting Allan deviation of the frequency output of the piezoresistive oscillator, which successfully explains the experimental observations and the mechanism of frequency stability enhancement via synchronization.

  7. Computational methods for coupling microstructural and micromechanical materials response simulations

    SciTech Connect

    HOLM,ELIZABETH A.; BATTAILE,CORBETT C.; BUCHHEIT,THOMAS E.; FANG,HUEI ELIOT; RINTOUL,MARK DANIEL; VEDULA,VENKATA R.; GLASS,S. JILL; KNOROVSKY,GERALD A.; NEILSEN,MICHAEL K.; WELLMAN,GERALD W.; SULSKY,DEBORAH; SHEN,YU-LIN; SCHREYER,H. BUCK

    2000-04-01

    Computational materials simulations have traditionally focused on individual phenomena: grain growth, crack propagation, plastic flow, etc. However, real materials behavior results from a complex interplay between phenomena. In this project, the authors explored methods for coupling mesoscale simulations of microstructural evolution and micromechanical response. In one case, massively parallel (MP) simulations for grain evolution and microcracking in alumina stronglink materials were dynamically coupled. In the other, codes for domain coarsening and plastic deformation in CuSi braze alloys were iteratively linked. this program provided the first comparison of two promising ways to integrate mesoscale computer codes. Coupled microstructural/micromechanical codes were applied to experimentally observed microstructures for the first time. In addition to the coupled codes, this project developed a suite of new computational capabilities (PARGRAIN, GLAD, OOF, MPM, polycrystal plasticity, front tracking). The problem of plasticity length scale in continuum calculations was recognized and a solution strategy was developed. The simulations were experimentally validated on stockpile materials.

  8. Thermally induced micromechanical stresses in ceramic/ceramic composites

    SciTech Connect

    Li, Zhuang; Bradt, R.C.

    1992-11-01

    The internal micromechanical stresses which develop in ceramic-ceramic composites as a consequence of temperature changes and thermoelastic property differences between the reinforcing and matrix phases are addressed by the Eshelby method. Results for two whisker reinforced ceramic matrix composites and for quartz particles in porcelain are discussed. It is concluded that the stresses which develop in the second phase reinforcing inclusions are quite substantial (GPa-levels) and may be highly anisotropic in character. These stresses are additive to the macroscopic thermal stresses from temperature gradients which are encountered during heating and cooling, and also to externally apphed mechanical stresses (loads). These micromechanical stresses are expected to be highly significant for thermal cycling fatigue and other failure processes.

  9. An international campaign of the 19th century to determine the solar parallax. The US Naval expedition to the southern hemisphere 1849-1852

    NASA Astrophysics Data System (ADS)

    Schrimpf, Andreas

    2014-04-01

    In 1847 Christian Ludwig Gerling, Marburg (Germany), suggested the solar parallax to be determined by measuring the position of Venus close to its inferior conjunction, especially at the stationary points, from observatories on nearly the same meridian but widely differing in latitude. James M. Gilliss, astronomer at the newly founded U.S. Naval Observatory, enthusiastically adopted this idea and procured a grant for the young astronomical community of the United States for an expedition to Chile. There they were to observe several conjunctions of Venus and oppositions of Mars, while the accompanying measurements were to be taken at the US Naval Observatory in Washington D.C. and the Harvard College Observatory at Cambridge, USA. This expedition was supported by A.V. Humboldt, C.F. Gauß, J.F. Encke, S.C. Walker, A.D. Bache, B. Peirce and others. From 1849 to 1852 not only were astronomical, but also meteorological and magnetic observations and measurements recorded, mainly in Santa Lucia close to Santiago, Chile. By comparing these measurements with those taken simultaneously at other observatories around the world the solar parallax could be calculated, although incomplete data from the corresponding northern observatories threatened the project's success. In retrospect this expedition can be recognized as the foundation of the Chilean astronomy. The first director of the new National Astronomical Observatory of Chile was Dr. C.W. Moesta, a Hessian student of Christian Ludwig Gerling's. The exchange of data between German, American and other astronomers during this expedition was well mediated by J.G. Flügel, consul of the United States of America and representative of the Smithsonian Institution in Europe, who altogether played a major role in nurturing the relationship between the growing scientific community in the U.S. and the well established one in Europe at that time.

  10. [The patent of Dr. Thibert: models of organs and his secret modeling at the beginning of the 19th century. Analysis of the stomach model (a8n°8) at the Conservatory of Montpellier].

    PubMed

    Noirot, Fabien

    2015-01-01

    In the early 19th century, Dr. Thibert discovered a process to overcome the difficulties of casting soft and moist organs. However, the analysis of a stomach made by Thibert reveals a modeling, changing the strict mechanical objectivity of the cast. This modeling inside the cast named "reparation" structures the illusionism of this cast. The scientific and artistic aspect of this study is to establish the typology of a secret modeling. This last one is the inheritance of the tricks of the mediocritas: between material and matter, so valuable for the goldsmiths of the 16th century.

  11. Introduction to the special issue on the joint meeting of the 19th IEEE International Symposium on the Applications of Ferroelectrics and the 10th European Conference on the Applications of Polar Dielectrics.

    PubMed

    Tsurumi, Takaaki

    2011-09-01

    The joint meeting of the 19th IEEE International Symposium on the Applications of Ferroelectrics and the 10th European Conference on the Applications of Polar Dielectrics took place in Edinburgh from August 9-12, 2010. The conference was attended by 390 delegates from more than 40 different countries. There were 4 plenary speakers, 56 invited speakers, and a further 222 contributed oral presentations in 7 parallel session. In addition there were 215 poster presentations. Key topics addressed at the conference included piezoelectric materials, leadfree piezoelectrics, and multiferroics.

  12. [Problems arising from the professionalization of nursing in the German Empire in the late 19th and early 20th century compared to the USA. A contribution to the current discussion].

    PubMed

    Hähner-Rombach, Sylvelyn

    2012-01-01

    The process of professionalization in Germany was hindered by several factors: the tradition of denominational nursing, the increasing segregation in the field of nursing, the resistance against nurses' professionalization, the late and sporadic institutionalization of nursing schools, and the classification of nursing as "ärztlicher Heilhilfsberuf". On the basis of these five influencing factors this paper will discuss the development in Germany in comparison to the USA at the end of the 19th and early 20th centuries. The aim is to explain the differences in the process of professionalization in the German Reich and the USA which are rooted in that period.

  13. Micromechanics of Composite Materials Governed by Vector Constitutive Laws

    NASA Technical Reports Server (NTRS)

    Bednarcyk, Brett A.; Aboudi, Jacob; Arnold, Steven M.

    2017-01-01

    The high-fidelity generalized method of cells micromechanics theory has been extended for the prediction of the effective property tensor and the corresponding local field distributions for composites whose constituents are governed by vector constitutive laws. As shown, the shear analogy, which can predict effective transverse properties, is not valid in the general three-dimensional case. Consequently, a general derivation is presented that is applicable to both continuously and discontinuously reinforced composites with arbitrary vector constitutive laws and periodic microstructures. Results are given for thermal and electric problems, effective properties and local field distributions, ordered and random microstructures, as well as complex geometries including woven composites. Comparisons of the theory's predictions are made to test data, numerical analysis, and classical expressions from the literature. Further, classical methods cannot provide the local field distributions in the composite, and it is demonstrated that, as the percolation threshold is approached, their predictions are increasingly unreliable. XXXX It has been observed that the bonding between the fibers and matrix in composite materials can be imperfect. In the context of thermal conductivity, such imperfect interfaces have been investigated in micromechanical models by Dunn and Taya (1993), Duan and Karihaloo (2007), Nan et al. (1997) and Hashin (2001). The present HFGMC micromechanical method, derived for perfectly bonded composite materials governed by vector constitutive laws, can be easily generalized to include the effects of weak bonding between the constituents. Such generalizations, in the context of the mechanical micromechanics problem, involve introduction of a traction-separation law at the fiber/matrix interface and have been presented by Aboudi (1987), Bednarcyk and Arnold (2002), Bednarcyk et al. (2004) and Aboudi et al. (2013) and will be addressed in the future.

  14. Micromechanics and Piezo Enhancements of HyperSizer

    NASA Technical Reports Server (NTRS)

    Arnold, Steven M.; Bednarcyk, Brett A.; Yarrington, Phillip; Collier, Craig S.

    2006-01-01

    The commercial HyperSizer aerospace-composite-material-structure-sizing software has been enhanced by incorporating capabilities for representing coupled thermal, piezoelectric, and piezomagnetic effects on the levels of plies, laminates, and stiffened panels. This enhancement is based on a formulation similar to that of the pre-existing HyperSizer capability for representing thermal effects. As a result of this enhancement, the electric and/or magnetic response of a material or structure to a mechanical or thermal load, or its mechanical response to an applied electric or magnetic field can be predicted. In another major enhancement, a capability for representing micromechanical effects has been added by establishment of a linkage between HyperSizer and Glenn Research Center s Micromechanics Analysis Code With Generalized Method of Cells (MAC/GMC) computer program, which was described in several prior NASA Tech Briefs articles. The linkage enables Hyper- Sizer to localize to the fiber and matrix level rather than only to the ply level, making it possible to predict local failures and to predict properties of plies from those of the component fiber and matrix materials. Advanced graphical user interfaces and database structures have been developed to support the new HyperSizer micromechanics capabilities.

  15. Micromechanisms of thermomechanical fatigue: A comparison with isothermal fatigue

    NASA Technical Reports Server (NTRS)

    Bill, R. C.

    1986-01-01

    Thermomechanical Fatigue (TMF) experiments were conducted on Mar-M 200, B-1900, and PWA-1480 (single crystals) over temperature ranges representative of gas turbine airfoil environments. The results were examined from both a phenomenological basis and a micromechanical basis. Depending on constituents present in the superalloy system, certain micromechanisms dominated the crack initiation process and significantly influenced the TMF lives as well as sensitivity of the material to the type TMF cycle imposed. For instance, high temperature cracking around grain boundary carbides in Mar-M 200 resulted in short in-phase TMF lives compared to either out-of-phase or isothermal lives. In single crystal PWA-1480, the type of coating applied was seen to be the controlling factor in determining sensitivity to the type of TMF cycle imposed. Micromechanisms of deformation were observed over the temperature range of interest to the TMF cycles, and provided some insight as to the differences between TMF damage mechanisms and isothermal damage mechanisms. Finally, the applicability of various life prediction models to TMF results was reviewed. Current life prediction models based on isothermal data must be modified before being generally applied to TMF.

  16. Comprehensive Micromechanics-Analysis Code - Version 4.0

    NASA Technical Reports Server (NTRS)

    Arnold, S. M.; Bednarcyk, B. A.

    2005-01-01

    Version 4.0 of the Micromechanics Analysis Code With Generalized Method of Cells (MAC/GMC) has been developed as an improved means of computational simulation of advanced composite materials. The previous version of MAC/GMC was described in "Comprehensive Micromechanics-Analysis Code" (LEW-16870), NASA Tech Briefs, Vol. 24, No. 6 (June 2000), page 38. To recapitulate: MAC/GMC is a computer program that predicts the elastic and inelastic thermomechanical responses of continuous and discontinuous composite materials with arbitrary internal microstructures and reinforcement shapes. The predictive capability of MAC/GMC rests on a model known as the generalized method of cells (GMC) - a continuum-based model of micromechanics that provides closed-form expressions for the macroscopic response of a composite material in terms of the properties, sizes, shapes, and responses of the individual constituents or phases that make up the material. Enhancements in version 4.0 include a capability for modeling thermomechanically and electromagnetically coupled ("smart") materials; a more-accurate (high-fidelity) version of the GMC; a capability to simulate discontinuous plies within a laminate; additional constitutive models of materials; expanded yield-surface-analysis capabilities; and expanded failure-analysis and life-prediction capabilities on both the microscopic and macroscopic scales.

  17. Micromechanical characterization tools for highly-filled polymers

    SciTech Connect

    Groves, S; DeTeresa, S; Cunningham, B; Ciarlo, D; Allen, D; Clayton, K; Yoon, C

    2000-02-16

    We are attempting to characterize and model the micromechanical response of highly-filled polymers. In this class of materials, the continuous plastic binder used to bond the highly-filled material dominates the observed viscoelastic response. As a result, realistic lifetime analysis of these materials will require a thorough understanding of the contribution of the plastic binder. Laboratory applications of these materials include plastic bonded explosives, propellants, a variety of specialized filled organic materials for stockpile systems, and highly filled epoxy dielectric materials for the National Ignition Facility. We have explored numerous techniques to characterize the local microstructure of plastic bonded explosives. However, insufficient funding was obtained to bring these technologies to maturity, nevertheless our present tool set is significantly better than 2 years ago. We have also made some progress in developing an appropriate micromechanical constitutive modeling framework, based on a finite element method incorporating a cohesive zone model to represent the binder contribution within a Voronoi tesselation mesh structure for the PBX grains. A second modeling approach was used to incorporate analytical micromechanics (generalized self-consistent schemes). However, preliminary theoretical analysis strongly suggested that this approach would be invalid for such extremely high-filled systems like PBX.

  18. Europe Revised.

    ERIC Educational Resources Information Center

    Sewall, Gilbert T.

    1993-01-01

    A recent succession of landmark events have rendered world history textbooks out of date. Educators need to answer students' questions about the changes of the past few years and provide some context as to the causes of change. Lists a number of selected resources for information on eastern Europe and the former Soviet Union. (MLF)

  19. Maternal genealogical patterns of chicken breeds sampled in Europe.

    PubMed

    Lyimo, C M; Weigend, A; Msoffe, P L; Hocking, P M; Simianer, H; Weigend, S

    2015-08-01

    The aim of this study was to investigate the maternal genealogical pattern of chicken breeds sampled in Europe. Sequence polymorphisms of 1256 chickens of the hypervariable region (D-loop) of mitochondrial DNA (mtDNA) were used. Median-joining networks were constructed to establish evolutionary relationships among mtDNA haplotypes of chickens, which included a wide range of breeds with different origin and history. Chicken breeds which have had their roots in Europe for more than 3000 years were categorized by their founding regions, encompassing Mediterranean type, East European type and Northwest European type. Breeds which were introduced to Europe from Asia since the mid-19th century were classified as Asian type, and breeds based on crossbreeding between Asian breeds and European breeds were classified as Intermediate type. The last group, Game birds, included fighting birds from Asia. The classification of mtDNA haplotypes was based on Liu et al.'s (2006) nomenclature. Haplogroup E was the predominant clade among the European chicken breeds. The results showed, on average, the highest number of haplotypes, highest haplotype diversity, and highest nucleotide diversity for Asian type breeds, followed by Intermediate type chickens. East European and Northwest European breeds had lower haplotype and nucleotide diversity compared to Mediterranean, Intermediate, Game and Asian type breeds. Results of our study support earlier findings that chicken breeds sampled in Europe have their roots in the Indian subcontinent and East Asia. This is consistent with historical and archaeological evidence of chicken migration routes to Europe.

  20. The restart of meteorological observations in the 19th century in Lisbon: the contribution of Marino Miguel FRANZINI (1779-1861)

    NASA Astrophysics Data System (ADS)

    Alcoforado, Maria-Joao; Nunes, Fatima

    2013-04-01

    After the early meteorological observations of the 1770s to the 1790s in continental Portugal (including a 5 year daily series by J. Velho), there were hardly any until 1815. In December 1815, a meteorological station was set up in Lisbon by Marino Miguel Franzini (1779-1861), an engineer who was also actively involved in Politics (liberal party). Following the tradition of the 18th century enlightenment movement, he took a keen interest in Nature and Sciences, particularly in the "influence" of weather and climate on health and agriculture. Franzini started his observations by request of a physician who sought to understand the reasons why the maximum mortality occurred on the summer months, unlike in northern countries of Europe where maximum mortality occurred in winter (as it happens nowadays in Portugal). The deterministic background of the two scientists is clear. Franzini was a member of the Lisbon Academy of Sciences (founded in 1799) and had contact with foreign Academies and foreign scientists. His instruments were carefully constructed and described, including graduation scales, and stations' location was indicated. Data from two years observations (several meteorological variables) was published in the Academy of Sciences Memoirs. From 1818 until 1826 and from 1835 until 1856 data was divulged in journals and newspapers, such as the "Journal of Medical Sciences", together with data on necrology in some of Lisbon parishes (illustrating the interest of physicians on weather); meteorological data and information about agriculture was also published in the "Lisbon Gazette". Unfortunately, there are hardly any daily data, as Franzini grouped his records according to weather types, as will be explained. Franzini's series will be presented in our talk. The gap between 1826 and 1835 was due to the political activities in which Franzini was involved: the civil war (liberals against absolutist) disruptedscientific research in Portugal. Official meteorological

  1. Micromechanical Prediction of the Effective Coefficients of Thermo-Piezoelectric Multiphase Composites

    NASA Technical Reports Server (NTRS)

    Aboudi, Jacob

    1998-01-01

    The micromechanical generalized method of cells model is employed for the prediction of the effective elastic, piezoelectric, dielectric, pyroelectric and thermal-expansion constants of multiphase composites with embedded piezoelectric materials. The predicted effective constants are compared with other micromechanical methods available in the literature and good agreements are obtained.

  2. Micromechanics and advanced designs for curved photodetector arrays in hemispherical electronic-eye cameras.

    PubMed

    Shin, Gunchul; Jung, Inhwa; Malyarchuk, Viktor; Song, Jizhou; Wang, Shuodao; Ko, Heung Cho; Huang, Yonggang; Ha, Jeong Sook; Rogers, John A

    2010-04-09

    The fabrication of a hemispherical electronic-eye camera with optimized designs based upon micromechanical analysis is reported. The photodetector arrays combine layouts with multidevice tiles and extended, non-coplanar interconnects to improve the fill factor and deformability, respectively. Quantitative comparison to micromechanics analysis reveals the key features of these designs. Color images collected with working cameras demonstrate the utility of these approaches.

  3. The Impacts of Advancing Glaciers and Jökulhlaups on the 19th Century Farming Community in the Suðursveit District South of Vatnajökull Glacier, Iceland.

    NASA Astrophysics Data System (ADS)

    Sigurmundsson, F. S.; Gísladóttir, G.; Erlendsson, E.

    2014-12-01

    Few areas in Iceland were as vulnerable to climate changes during the 19th century as the region south of Vatnajökull glacier. The region was repeatedly affected by glacier advance and jökulhlaups (glacier outburst floods) during the Little Ice Age AD 1300-1900 (LIA). The land area between the glacier and the coast was occupied by farming community. The aim of this research is to quantify and map the size of lost vegetated area in the 19th century during the glacial advance in the climax of the LIA and the impact these events had on the community, land-use, ownership, value of estates and livelihood. This research employs historical written sources to investigate changes in the cultural and natural landscape. Historical data and field observations will be collected and stored in a GIS database designed for the research, allowing data to be analyzed and presented on maps. The first recorded impact on the settlement is from 1794 when the Breiðármerkurjökull outlet glacier advanced and devastated pastures and crofts belonging in west of the district. Seventy five years later, in 1868, the largest estate was completely destroyed by a jökulhlaup. In 1829 a farm site in the middle of the district was moved due to repeated jökulhlaup. The outlet glacier Brókarjökull initiated annual jökulhlaups during 1820 -1870, devastating pastures and hayfields and woodlands of a total of 3 prominent estates in the area (by 1200 ha), causing devaluation of 33-66% on these estates. In the eastern part extensive jökulhlaups changed the glacial river channel causing the river to flow over vast area devastating 80 % of the eastern most estate causing its abandonment in 1892. The climate change and accompanied hazards during the 19th century changed the landscape of the Suðursveit district significantly. By the turn of the 20thcentury the vegetated land in the district had been reduced by 35% and areas of sediments increased by 25% and glaciated area increased by 10%. These

  4. Micromechanics of deformation in particle-toughened polyamides

    NASA Astrophysics Data System (ADS)

    Tzika, P. A.; Boyce, M. C.; Parks, D. M.

    2000-09-01

    It is now well appreciated that a number of semicrystalline polymers can be effectively toughened by the addition of a well-dispersed secondary phase, when the average interparticle matrix ligament thickness, Λ, of the blend is reduced below a critical length parameter, Λc. This critical parameter is a specific material characteristic of the base polymer and can be achieved by various combinations of filler particle volume fraction and particle size. Recently, the significant improvements in toughness achieved when Λ≤ Λc were attributed to a morphological transition taking place when interface-induced crystallization of characteristic thickness Λc/2 successfully percolates through the primary phase. These transcrystallized layers are highly anisotropic in their mechanical response and, as a result, change the preferred modes of plastic deformation in the material, enabling the large plastic strains, which provide the high toughness. This study aims to elucidate the micromechanics and micromechanisms responsible for the high toughness exhibited by these morphologically altered heterogeneous systems via a series of micromechanical models. The case of polyamide-6 modified with cavitating spherical elastomeric particles treated as voids is modeled. It is found that the mechanical response and local modes of plastic deformation of these systems depend strongly on the morphology of the primary phase, the volume fraction of filler particles and the level of applied stress triaxiality. In particular, when Λ< Λc and highly textured material percolates through the matrix, the material is found to deform by multiple shear banding along crystallographic planes of low shear resistance in the matrix ligaments diagonally bridging particles. This mode of plastic deformation is found to be robust to increases in triaxiality and, indeed, the textured material acts to resist void growth while promoting shear along the preferentially oriented crystallographic planes.

  5. Localised micro-mechanical stiffening in the ageing aorta

    PubMed Central

    Graham, Helen K.; Akhtar, Riaz; Kridiotis, Constantinos; Derby, Brian; Kundu, Tribikram; Trafford, Andrew W.; Sherratt, Michael J.

    2011-01-01

    Age-related loss of tissue elasticity is a common cause of human morbidity and arteriosclerosis (vascular stiffening) is associated with the development of both fatal strokes and heart failure. However, in the absence of appropriate micro-mechanical testing methodologies, multiple structural remodelling events have been proposed as the cause of arteriosclerosis. Therefore, using a model of ageing in female sheep aorta (young: <18 months, old: >8 years) we: (i) quantified age-related macro-mechanical stiffness, (ii) localised in situ micro-metre scale changes in acoustic wave speed (a measure of tissue stiffness) and (iii) characterised collagen and elastic fibre remodelling. With age, there was an increase in both macro-mechanical stiffness and mean microscopic wave speed (and hence stiffness; young wave speed: 1701 ± 1 m s−1, old wave speed: 1710 ± 1 m s−1, p < 0.001) which was localized to collagen fibril-rich regions located between large elastic lamellae. These micro-mechanical changes were associated with increases in both collagen and elastic fibre content (collagen tissue area, young: 31 ± 2%, old: 40 ± 4%, p < 0.05; elastic fibre tissue area, young: 55 ± 3%, old: 69 ± 4%, p < 0.001). Localised collagen fibrosis may therefore play a key role in mediating age-related arteriosclerosis. Furthermore, high frequency scanning acoustic microscopy is capable of co-localising micro-mechanical and micro-structural changes in ageing tissues. PMID:21777602

  6. Prediction of Composite Laminate Fracture: Micromechanics and Progressive Fracture

    NASA Technical Reports Server (NTRS)

    Gotsis, P. K.; Chamis, C. C.; Minnetyan, L.

    1996-01-01

    This report describes an investigation to predict first-ply failure and final fracture in selected composite laminates subjected to inplane loads. The laminates were composed of glass fiber and graphite fibers in epoxy matrices. Failure envelopes based on first-ply failure and laminate fracture were generated for combined loading of these laminates. Predictions were evaluated by micromechanics-based theory and progressive fracture. The results show that, for most cases, combined tensile loading significantly enhanced the laminate fracture stress in comparison to the uniaxial loading.

  7. Micromechanical properties of hydrogels measured with MEMS resonant sensors.

    PubMed

    Corbin, Elise A; Millet, Larry J; Pikul, James H; Johnson, Curtis L; Georgiadis, John G; King, William P; Bashir, Rashid

    2013-04-01

    Hydrogels have gained wide usage in a range of biomedical applications because of their biocompatibility and the ability to finely tune their properties, including viscoelasticity. The use of hydrogels on the microscale is increasingly important for the development of drug delivery techniques and cellular microenvironments, though the ability to accurately characterize their micromechanical properties is limited. Here we demonstrate the use of microelectromechanical systems (MEMS) resonant sensors to estimate the properties of poly(ethylene glycol) diacrylate (PEGDA) microstructures over a range of concentrations. These microstructures are integrated on the sensors by deposition using electrohydrodynamic jet printing. Estimated properties agree well with independent measurements made using indentation with atomic force microscopy.

  8. Method of Manufacturing a Micromechanical Oscillating Mass Balance

    NASA Technical Reports Server (NTRS)

    Altemir, David A. (Inventor)

    1999-01-01

    A micromechanical oscillating mass balance and method adapted for measuring minute quantities of material deposited at a selected location, such as during a vapor deposition process. The invention comprises a vibratory composite beam which includes a dielectric layer sandwiched between two conductive layers.The beam is positioned in a magnetic field. An alternating current passes through one conductive layers, the beam oscillates, inducing an output current in the second conductive layer, which is analyzed to determine the resonant frequency of the beam. As material is deposited on the beam, the mass of the beam increases and the resonant frequency of the beam shifts, and the mass added is determined.

  9. Micromechanical study of concrete materials with interfacial transition zone

    NASA Astrophysics Data System (ADS)

    Gambheera, Ramesh

    This thesis describes analytical and finite element micromechanical studies for investigating the mechanical behavior of concrete materials. A concrete material is treated as a three phase composite consisting of aggregate, bulk paste and an interfacial transition zone around the aggregate. Experimental work on the microstructure of concrete has demonstrated the existence of interfacial transition zone and that this is the weakest link in the composite system of concrete material. Hence, the main focus of this thesis is to understand the role of the interfacial transition zone on the overall mechanical behavior of concrete materials. A four phase composite model consisting of aggregate, ITZ, bulk paste and an equivalent homogeneous medium is proposed to represent the concrete material. Analytical solutions are derived for the overall elastic moduli of the four phase composite model. The effects of volume fraction and the elastic moduli of the transition zone on the overall elastic moduli are investigated. The results obtained using the analytical model are in good agreement with those obtained from experiments. Analytical stress solutions are also derived for the four phase composite model subjected to uniaxial compression in two and three dimensions. The stress concentration and the tensile stress development in the interfacial transition zone are investigated. The effect of imperfect shear interfacial bond on the overall elastic moduli and on the stresses in the transition zone is also investigated. Basic concepts of damage mechanics are applied to model the damage in the transition zone. The effect of local damage in the transition zone on the overall damage in a concrete material is illustrated. For the specific case of uniaxial compression, the pre-peak stress-strain curves are generated. Computational analysis of micromechanical models of concrete materials requires efficient finite elements. This thesis proposes the use of hybrid finite elements for the

  10. Interfacial micromechanics in fibrous composites: design, evaluation, and models.

    PubMed

    Lei, Zhenkun; Li, Xuan; Qin, Fuyong; Qiu, Wei

    2014-01-01

    Recent advances of interfacial micromechanics in fiber reinforced composites using micro-Raman spectroscopy are given. The faced mechanical problems for interface design in fibrous composites are elaborated from three optimization ways: material, interface, and computation. Some reasons are depicted that the interfacial evaluation methods are difficult to guarantee the integrity, repeatability, and consistency. Micro-Raman study on the fiber interface failure behavior and the main interface mechanical problems in fibrous composites are summarized, including interfacial stress transfer, strength criterion of interface debonding and failure, fiber bridging, frictional slip, slip transition, and friction reloading. The theoretical models of above interface mechanical problems are given.

  11. Simple micromechanical model of protein crystals for their mechanical characterizations

    NASA Astrophysics Data System (ADS)

    Yoon, G.; Eom, K.; Na, S.

    2010-06-01

    Proteins have been known to perform the excellent mechanical functions and exhibit the remarkable mechanical properties such as high fracture toughness in spider silk protein [1]. This indicates that the mechanical characterization of protein molecules and/or crystals is very essential to understand such remarkable mechanical function of protein molecules. In this study, for gaining insight into mechanical behavior of protein crystals, we developed the micromechanical model by using the empirical potential field prescribed to alpha carbon atoms of a protein crystal in a unit cell. We consider the simple protein crystals for their mechanical behavior under tensile loading to be compared with full atomic models

  12. A Micromechanical Contribution to Cochlear Tuning and Tonotopic Organization

    NASA Astrophysics Data System (ADS)

    Holton, Thomas; Hudspeth, A. J.

    1983-11-01

    The response properties of hair cells and nerve fibers in the alligator lizard cochlea are frequency selective and tonotopically organized with longitudinal position in the organ. The lengths of the hair-cell hair bundles also vary monotonically with longitudinal position. In this study, quantitative measurements were made of the motion of individual hair bundles in an excised preparation of the cochlea stimulated at auditory frequencies. The angular displacement of hair bundles is frequency selective and tonotopically organized, demonstrating the existence of a micromechanical tuning mechanism.

  13. Detection of electromagnetic radiation using micromechanical multiple quantum wells structures

    DOEpatents

    Datskos, Panagiotis G [Knoxville, TN; Rajic, Slobodan [Knoxville, TN; Datskou, Irene [Knoxville, TN

    2007-07-17

    An apparatus and method for detecting electromagnetic radiation employs a deflectable micromechanical apparatus incorporating multiple quantum wells structures. When photons strike the quantum-well structure, physical stresses are created within the sensor, similar to a "bimetallic effect." The stresses cause the sensor to bend. The extent of deflection of the sensor can be measured through any of a variety of conventional means to provide a measurement of the photons striking the sensor. A large number of such sensors can be arranged in a two-dimensional array to provide imaging capability.

  14. PREFACE: Special issue: Proceedings of the Joint 19th AIRAPT and 41st EHPRG International Conference on High Pressure Science and Technology (Bordeaux, 7--11 July 2003)

    NASA Astrophysics Data System (ADS)

    Demazeau, Gérard

    2004-04-01

    This volume is the outcome of a three-day meeting held 7-10 August, 2004 in St Adèle, Québec honouring Michael F Thorpe, Foundation Professor of Physics, Chemistry and Biophysics at Arizona State University. Michael Thorpe has made many important contributions to condensed matter physics, broadly defined. From the famous Weaire and Thorpe Hamiltonian in 1971 [1] to rigidity percolation theory [2] and flexibility in proteins [3], he has always provided highly original solutions to difficult problems. He has also demonstrated an uncommon gift for selecting and solving problems of remarkably broad significance (for example, rigidity theory is now a powerful tool in glasses, microelectronics and proteins). Throughout his career, Mike has also made a point of establishing contact with scientists from all disciplines and origins, organizing tens of conferences and maintaining a very active visitor's program both at Michigan State University, where he spent 25 years, and, now, at Arizona State University, where he moved a year ago. It is therefore not surprising that the participants, all with scientific or personal links with Mike, usually both, came from Europe, Asia and North America to celebrate the 60th birthday of an eminent physicist and friend. Reflecting the impact of Mike's work across the traditional scientific boundaries, the meeting included contributions ranging from studies of concrete by Ed Garboczi (NIST), a hybrid VCA/CPA treatment of the Hubbard model presented by Sir Roger Elliott (Oxford) to the assembly process of viral capsids by Brandon Hespenheide (ASU). Especially memorable talks were given by Rafael Barrio (with his photogenic striped imperial fish), Alex Kolobov (presenting impressive scientific results using equally impressive computer graphics), and Dick Zallen, for a remarkably good `roast' of the honoree and work with his daughter (a molecular biologist) on biophysics. The meeting had an unusual warmth befitting the birthday celebration

  15. The identification of the pigments used to paint statues of Feixiange Cliff in China in late 19th century by micro-Raman spectroscopy and scanning electron microscopy/energy dispersive X-ray analysis

    NASA Astrophysics Data System (ADS)

    Jin, Pu-jun; Huang, Wei; Jianhua-Wang; Zhao, Gang; Wang, Xiao-ling

    2010-11-01

    The application of micro-Raman spectroscopy (μ-RS) and scanning electron microscopy (SEM)/energy dispersive X-ray spectrometer (EDS) to the research of pigments collected from Statues of Feixiange Cliff No. 67 and No. 69 niche of Tang Dynasty in China is reported. Five kinds of pigments were found in the experimental data, including black (carbon), white (gypsum + quartz), blue (lapis lazuli) and green (Paris green + Barium sulphate). After synthesized in 1814, Paris green was reported for a large import as a light and bright green pigment to paint architectures in China from the late 19th century. The analyzed blue pigment demonstrated the similar Raman spectra to the Lâjvardina blue glazed ceramics, which indicated lapis lazuli was an artificial product. This confirmed the painting of Feixiange Cliff in the early Republic of China as the historical record, and also reveals that some pigments were imported from abroad.

  16. [Is medicine an art or a science?--considerations in the light of Polish school of medicine philosophy and views of other European doctors from the beginning of 19th century till outbreak of the Second World War"].

    PubMed

    Gryglewski, Ryszard W

    2006-01-01

    This paper is devoted to the problem of real nature of medicine, as it was seen in Polish school of the philosophy of the medicine. Is medicine more (or only) science, or is it an art was the crucial point of discussion, which was held in European philosophy of the medicine for the first time in late 19th century. The important voice in it was given by Polish scientists such as Zygmunt Kramsztyk, Henryk Nusbaum, Władysław Biegański, Edmund Biernacki, Władyslaw Szumowski and Ludwik Zembrzuski. How they understood place and meaning of medicine in the realm of human activities, in which points they found the same grounds and in which they differed, should be seen as the main topic for this article.

  17. Micromechanical modeling of the cement-bone interface: the effect of friction, morphology and material properties on the micromechanical response

    PubMed Central

    Janssen, Dennis; Mann, Kenneth A.; Verdonschot, Nico

    2008-01-01

    In order to gain insight into the micro-mechanical behavior of the cement-bone interface, the effect of parametric variations of frictional, morphological and material properties on the mechanical response of the cement-bone interface were analyzed using a finite element approach. Finite element models of a cement-bone interface specimen were created from micro-computed tomography data of a physical specimen that was sectioned from an in vitro cemented total hip arthroplasty. In five models the friction coefficient was varied (μ= 0.0; 0.3; 0.7; 1.0 and 3.0), while in one model an ideally bonded interface was assumed. In two models cement interface gaps and an optimal cement penetration were simulated. Finally, the effect of bone cement stiffness variations was simulated (2.0 and 2.5 GPa, relative to the default 3.0 GPa). All models were loaded for a cycle of fully reversible tension-compression. From the simulated stress-displacement curves the interface deformation, stiffness and hysteresis were calculated. The results indicate that in the current model the mechanical properties of the cement-bone interface were caused by frictional phenomena at the shape-closed interlock rather than by adhesive properties of the cement. Our findings furthermore show that in our model maximizing cement penetration improved the micromechanical response of the cement-bone interface stiffness, while interface gaps had a detrimental effect. Relative to the frictional and morphological variations, variations in the cement stiffness had only a modest effect on the micromechanical behavior of the cement-bone interface. The current study provides information that may help to better understand the load transfer mechanisms taking place at the cement-bone interface. PMID:18848699

  18. Micromechanics of TEMPO-oxidized fibrillated cellulose composites.

    PubMed

    Bulota, Mindaugas; Tanpichai, Supachok; Hughes, Mark; Eichhorn, Stephen J

    2012-01-01

    Composites of poly(lactic) acid (PLA) reinforced with TEMPO-oxidized fibrillated cellulose (TOFC) were prepared to 15, 20, 25, and 30% fiber weight fractions. To aid dispersion and to improve stress transfer, we acetylated the TOFC prior to the fabrication of TOFC-PLA composite films. Raman spectroscopy was employed to study the deformation micromechanics in these systems. Microtensile specimens were prepared from the films and deformed in tension with Raman spectra being collected simultaneously during deformation. A shift in a Raman peak initially located at ~1095 cm(-1), assigned to C-O-C stretching of the cellulose backbone, was observed upon deformation, indicating stress transfer from the matrix to the TOFC reinforcement. The highest band shift rate, with respect to strain, was observed in composites having a 30% weight fraction of TOFC. These composites also displayed a significantly higher strain to failure compared to pure acetylated TOFC film, and to the composites having lower weight fractions of TOFC. The stress-transfer processes that occur in microfibrillated cellulose composites are discussed with reference to the micromechanical data presented. It is shown that these TOFC-based composite materials are progressively dominated by the mechanics of the networks, and a shear-lag type stress transfer between fibers.

  19. Virtual mass effect in dynamic micromechanical mass sensing in liquids

    NASA Astrophysics Data System (ADS)

    Peiker, P.; Oesterschulze, E.

    2016-06-01

    Weighing individual micro- or nanoscale particles in solution using dynamic micromechanical sensors is quite challenging: viscous losses dramatically degrade the sensor's performance by both broadening the resonance peak and increasing the effective total mass of the resonator by the dragged liquid. While the virtual mass of the resonator was discussed frequently, little attention has been paid to the virtual mass of particles attached to the resonator's surface and its impact on the accuracy of mass sensing. By means of the in situ detection of a polystyrene microbead in water using a bridge-based microresonator, we demonstrate that the virtual mass of the bead significantly affects the observed frequency shift. In fact, 55 % of the frequency shift was caused by the virtual mass of the adsorbed bead, predicted by Stoke's theory. Based on the observed shift in the resonator's quality factor during particle adsorption, we confirm this significant effect of the virtual mass. Thus, a quantitative analysis of the mass of a single adsorbed particle is strongly diminished if dynamic micromechanical sensors are operated in a liquid environment.

  20. Micromechanics and constitutive modeling of connective soft tissues.

    PubMed

    Fallah, A; Ahmadian, M T; Firozbakhsh, K; Aghdam, M M

    2016-07-01

    In this paper, a micromechanical model for connective soft tissues based on the available histological evidences is developed. The proposed model constituents i.e. collagen fibers and ground matrix are considered as hyperelastic materials. The matrix material is assumed to be isotropic Neo-Hookean while the collagen fibers are considered to be transversely isotropic hyperelastic. In order to take into account the effects of tissue structure in lower scales on the macroscopic behavior of tissue, a strain energy density function (SEDF) is developed for collagen fibers based on tissue hierarchical structure. Macroscopic response and properties of tissue are obtained using the numerical homogenization method with the help of ABAQUS software. The periodic boundary conditions and the proposed constitutive models are implemented into ABAQUS using the DISP and the UMAT subroutines, respectively. The existence of the solution and stable material behavior of proposed constitutive model for collagen fibers are investigated based on the poly-convexity condition. Results of the presented micromechanics model for connective tissues are compared and validated with available experimental data. Effects of geometrical and material parameters variation at microscale on macroscopic mechanical behavior of tissues are investigated. The results show that decrease in collagen content of the connective tissues like the tendon due to diseases leads 20% more stretch than healthy tissue under the same load which can results in connective tissue malfunction and hypermobility in joints.

  1. Micromechanical Modeling of Impact Damage Mechanisms in Unidirectional Composite Laminates

    NASA Astrophysics Data System (ADS)

    Meng, Qinghua; Wang, Zhenqing

    2016-12-01

    Composite laminates are susceptible to the transverse impact loads resulting in significant damage such as matrix cracking, fiber breakage and delamination. In this paper, a micromechanical model is developed to predict the impact damage of composite laminates based on microstructure and various failure models of laminates. The fiber and matrix are represented by the isotropic and elastic-plastic solid, and their impact failure behaviors are modeled based on shear damage model. The delaminaton failure is modeling by the interface element controlled by cohesive damage model. Impact damage mechanisms of laminate are analyzed by using the micromechanical model proposed. In addition, the effects of impact energy and laminated type on impact damage behavior of laminates are investigated. Due to the damage of the surrounding matrix near the impact point caused by the fiber deformation, the surface damage area of laminate is larger than the area of ​​impact projectile. The shape of the damage area is roughly rectangle or elliptical with the major axis extending parallel to the fiber direction in the surface layer of laminate. The alternating laminated type with two fiber directions is more propitious to improve the impact resistance of laminates.

  2. Elongated Tetrakaidecahedron Micromechanics Model for Space Shuttle External Tank Foams

    NASA Technical Reports Server (NTRS)

    Sullivan, Roy M.; Ghosn, Louis J.; Lerch, Bradley A.; Baker, Eric H.

    2009-01-01

    The results of microstructural characterization studies and physical and mechanical testing of BX-265 and NCFI24-124 foams are reported. A micromechanics model developed previously by the authors is reviewed, and the resulting equations for the elastic constants, the relative density, and the strength of the foam in the principal material directions are presented. The micromechanics model is also used to derive equations to predict the effect of vacuum on the tensile strength and the strains induced by exposure to vacuum. Using a combination of microstructural dimensions and physical and mechanical measurements as input, the equations for the elastic constants and the relative density are applied and the remaining microstructural dimensions are predicted. The predicted microstructural dimensions are in close agreement with the average measured values for both BX-265 and NCFI24-124. With the microstructural dimensions, the model predicts the ratio of the strengths in the principal material directions for both foams. The model is also used to predict the Poisson s ratios, the vacuum-induced strains, and the effect of vacuum on the tensile strengths. However, the comparison of these predicted values with the measured values is not as favorable.

  3. Implementation of Higher Order Laminate Theory Into Strain Rate Dependent Micromechanics Analysis of Polymer Matrix Composites

    NASA Technical Reports Server (NTRS)

    Kim, Heung Soo; Zhu, Linfa; Chattopadhyay, Aditi; Goldberg, Robert K.

    2004-01-01

    A procedure has been developed to investigate the nonlinear response of composite plates under large strain and high strain rate loading. A recently developed strain dependent micromechanics model is extended to account for the shear effects during impact. Four different assumptions of shear deformation effects are investigated to improve the development strain rate dependent micromechanics model. A method to determine through the thickness strain and transverse Poisson's ratio is developed. The revised micromechanics model is implemented into higher order laminate theory. Parametric studies are conducted to investigate transverse shear effects during impact.

  4. A micromechanics constitutive model for pure dilatant martensitic transformation of ZrO2-containing ceramics

    NASA Astrophysics Data System (ADS)

    Qingping, Sun; Shouwen, Yu; Kehchih, Hwang

    1990-05-01

    A new micromechanics constitutive model for pure dilatant transformation plasticity of structure ceramics is proposed in this paper. Based on the thermodynamics, micromechanics and microscale t→m transformation mechanism analysis of the TZP and PSZ ZrO2-containing ceramics, an analytic expressions of the Helmholtz and complementary free energy of the constitutive element for the case of pure dilatant transformation is derived for the first time in a self-consistent manner. By the analysis of energy dissipation in the forward and reverse transformations, the micromechanics constitutive law is derived in the framework of Hill-Rice's internal variable constitutive theory.

  5. EDITORIAL: 16th European Workshop on Micromechanics (MME 2005)

    NASA Astrophysics Data System (ADS)

    Enoksson, Professor Peter

    2006-06-01

    This special issue of Journal of Micromechanics and Microengineering is devoted to the 16th European Workshop on Micromechanics (MME 2005), which was held in Göteborg, Sweden, at the Chalmers Conference Centre on the premises of Chalmers University of Technology, 4-6 September 2005. Göteborg is the second largest city in Sweden and is situated on the beautiful south-west coast. With its relaxed and friendly atmosphere Göteborg proudly lives up to its reputation of having the charm of a small town with all the opportunities of a big city. The MME workshop is a well recognized and established European event for creating microsensors and microactuators in the field of micromachining, microengineering and technology. The very first workshop was held at Twente University, The Netherlands, in 1989. Scientists and people from industry who are interested in the field gather annually for this event. The goals are stimulation and improvement of know-how in the field, as well as establishing cooperation and friendship between delegates. Thus MME is arranged so that people can meet in a friendly and informal atmosphere. That is why the accent is on mutual discussions around poster presentations rather than on formal oral presentations. The contributions, which came from 21 countries, were presented in four sessions and five keynote presentations. I am proud to present 24 high-quality papers from MME 2005 selected for their novelty and relevance to Journal of Micromechanics and Microengineering. Each paper passed a rigorous peer review process. May I take this opportunity to thank those authors who contributed their research to this special issue, which I hope gives an excellent overview of topics discussed at the workshop. I would also like to express my gratitude to Professor Robert Puers for advising on the selection of papers and to Dr Anke Sanz-Velasco for helping to coordinate the special issue with the Institute of Physics Publishing office at the start. I hope you

  6. Position control system for use with micromechanical actuators

    DOEpatents

    Guckel, Henry; Stiers, Eric W.

    2000-01-01

    A positioning system adapted for use with micromechanical actuators provides feedback control of the position of the movable element of the actuator utilizing a low Q sensing coil. The effective inductance of the sensing coil changes with position of the movable element to change the frequency of oscillation of a variable oscillator. The output of the variable oscillator is compared in a phase detector to a reference oscillator signal. The phase detector provides a pulsed output having a pulse duty cycle related to the phase or frequency difference between the oscillator signals. The output of the phase detector is provided to a drive coil which applies a magnetic force to the movable element which balances the force of a spring. The movable element can be displaced to a new position by changing the frequency of the reference oscillator.

  7. Micromechanical strength effects in shock compression of solids

    SciTech Connect

    Johnson, J.N.

    1993-06-01

    Time-resolved shock-wave measurements and post-shock recovery have long been used for inferring the underlaying micromechanics controlling high-rate deformation of solids; this requires considerable subjective interpretation. In spite of this, progress has been made in experimentation and theoretical interpretation of the shock-compression/release cycle and some of the results are reviewed here for weak shocks. This cycle involves the elements of the elastic precursor, plastic loading wave, pulse duration, release wave, and post-mortem examination. Those topics are examined, with emphasis on the second and fourth elements. Cu and Ta results show how shock data can be used to determine the transition from deformation mechanism of thermal activation to that of dislocation drag. Release-wave studies indicate that the leading observable release disturbance in fcc metals may not be propagating with the ideal longitudinal elastic-wave speed. 5 figs, 18 refs.

  8. Micromechanical strength effects in shock compression of solids

    SciTech Connect

    Johnson, J.N.

    1993-01-01

    Time-resolved shock-wave measurements and post-shock recovery have long been used for inferring the underlaying micromechanics controlling high-rate deformation of solids; this requires considerable subjective interpretation. In spite of this, progress has been made in experimentation and theoretical interpretation of the shock-compression/release cycle and some of the results are reviewed here for weak shocks. This cycle involves the elements of the elastic precursor, plastic loading wave, pulse duration, release wave, and post-mortem examination. Those topics are examined, with emphasis on the second and fourth elements. Cu and Ta results show how shock data can be used to determine the transition from deformation mechanism of thermal activation to that of dislocation drag. Release-wave studies indicate that the leading observable release disturbance in fcc metals may not be propagating with the ideal longitudinal elastic-wave speed. 5 figs, 18 refs.

  9. Micromechanics-Based Computational Simulation of Ceramic Matrix Composites

    NASA Technical Reports Server (NTRS)

    Murthy, Pappu L. N.; Mutal, Subodh K.; Duff, Dennis L. (Technical Monitor)

    2003-01-01

    Advanced high-temperature Ceramic Matrix Composites (CMC) hold an enormous potential for use in aerospace propulsion system components and certain land-based applications. However, being relatively new materials, a reliable design properties database of sufficient fidelity does not yet exist. To characterize these materials solely by testing is cost and time prohibitive. Computational simulation then becomes very useful to limit the experimental effort and reduce the design cycle time, Authors have been involved for over a decade in developing micromechanics- based computational simulation techniques (computer codes) to simulate all aspects of CMC behavior including quantification of scatter that these materials exhibit. A brief summary/capability of these computer codes with typical examples along with their use in design/analysis of certain structural components is the subject matter of this presentation.

  10. Micromechanical modeling of rate-dependent behavior of Connective tissues.

    PubMed

    Fallah, A; Ahmadian, M T; Firozbakhsh, K; Aghdam, M M

    2017-03-07

    In this paper, a constitutive and micromechanical model for prediction of rate-dependent behavior of connective tissues (CTs) is presented. Connective tissues are considered as nonlinear viscoelastic material. The rate-dependent behavior of CTs is incorporated into model using the well-known quasi-linear viscoelasticity (QLV) theory. A planar wavy representative volume element (RVE) is considered based on the tissue microstructure histological evidences. The presented model parameters are identified based on the available experiments in the literature. The presented constitutive model introduced to ABAQUS by means of UMAT subroutine. Results show that, monotonic uniaxial test predictions of the presented model at different strain rates for rat tail tendon (RTT) and human patellar tendon (HPT) are in good agreement with experimental data. Results of incremental stress-relaxation test are also presented to investigate both instantaneous and viscoelastic behavior of connective tissues.

  11. Micromechanical Simulations of Plastic-Bonded Explosives Containing HMX

    NASA Astrophysics Data System (ADS)

    Kober, Edward M.; Menikoff, Ralph S.

    1997-07-01

    The heterogeneous nature of plastic-bonded explosives, explosive crystals embedded in a rubbery binder, has long been recognized as an important factor in their initiation. In response to weak impacts, low pressure compaction waves are formed and lead to the localization of energy in the form of ``hot spots''. In order to understand the mechanism generating the hot spots and their resulting distribution, we have performed micromechanical simulations using the FLIP code of Brackbill, et al., which is based on the ``particle in a cell'' algorithm. These simulations have a distribution of HMX crystal sizes representative of a PBX. The crystals are modeled as either a pure elastic or elastic/plastic material with a linear Us/Up equation of state. The binder is represented as a viscoelastic material. The fluctuations in the local stress and temperature arising from low velocity plate impacts ( 100 m/s) are described.

  12. Pin joints, gears, springs, cranks, and other novel micromechanical structures

    SciTech Connect

    Fan, Long-Sheng; Tai, Yu-Chong; Muller, R.S.

    1987-08-01

    We report here the first fabrication of micrometer-scaled pin joints, gears, springs, cranks, and sliders made with silicon planar technology. These micromechanical structures are batch-fabricated in an IC-compatible process using polysilicon deposited by chemical vapor deposition from silane and the sacrificial-layer technique first described by Howe and Muller. An important feature of this new technology makes use of the high surface mobility of polysilicon during CVD growth to refill undercut regions in order to form restraining flanges. The movable mechanical elements are built on layers that are later removed to free them so that translation and rotation can take place. Although this initial demonstration of the technique for making these structures has employed polysilicon as the structural material and phosphosilicate glass (PSG) for the sacrificial layer, other materials compatible with the IC process can be substituted as appropriate.

  13. Nanoindentation analysis of the micromechanical anisotropy in mouse cortical bone

    PubMed Central

    Balmelli, Anna; Carnelli, Davide; Courty, Diana; Müller, Ralph

    2017-01-01

    Studies investigating micromechanical properties in mouse cortical bone often solely focus on the mechanical behaviour along the long axis of the bone. Therefore, data on the anisotropy of mouse cortical bone is scarce. The aim of this study is the first-time evaluation of the anisotropy ratio between the longitudinal and transverse directions of reduced modulus and hardness in mouse femurs by using the nanoindentation technique. For this purpose, nine 22-week-old mice (C57BL/6) were sacrificed and all femurs extracted. A total of 648 indentations were performed with a Berkovich tip in the proximal (P), central (C) and distal (D) regions of the femoral shaft in the longitudinal and transverse directions. Higher values for reduced modulus are obtained for indentations in the longitudinal direction, with anisotropy ratios of 1.72 ± 0.40 (P), 1.75 ± 0.69 (C) and 1.34 ± 0.30 (D). Hardness is also higher in the longitudinal direction, with anisotropic ratios of 1.35 ± 0.27 (P), 1.35 ± 0.47 (C) and 1.17 ± 0.19 (D). We observed a significant anisotropy in the micromechanical properties of the mouse femur, but the correlation for reduced modulus and hardness between the two directions is low (r2 < 0.3) and not significant. Therefore, we highly recommend performing independent indentation testing in both the longitudinal and transverse directions when knowledge of the tissue mechanical behaviour along multiple directions is required. PMID:28386450

  14. Characterization and modeling of electrostatically actuated polysilicon micromechanical devices

    NASA Astrophysics Data System (ADS)

    Chan, Edward Keat Leem

    Sensors, actuators, transducers, microsystems and MEMS (MicroElertroMechanical Systems) are some of the terms describing technologies that interface information processing systems with the physical world. Electrostatically actuated micromechanical devices are important building blocks in many of these technologies. Arrays of these devices are used in video projection displays, fluid pumping systems, optical communications systems, tunable lasers and microwave circuits. Well-calibrated simulation tools are essential for propelling ideas from the drawing board into production. This work characterizes a fabrication process---the widely-used polysilicon MUMPs process---to facilitate the design of electrostatically actuated micromechanical devices. The operating principles of a representative device---a capacitive microwave switch---are characterized using a wide range of electrical and optical measurements of test structures along with detailed electromechanical simulations. Consistency in the extraction of material properties from measurements of both pull-in voltage and buckling amplitude is demonstrated. Gold is identified as an area-dependent source of nonuniformity in polysilicon thicknesses and stress. Effects of stress gradients, substrate curvature, and film coverage are examined quantitatively. Using well-characterized beams as in-situ surface probes, capacitance-voltage and surface profile measurements reveal that compressible surface residue modifies the effective electrical gap when the movable electrode contacts an underlying silicon nitride layer. A compressible contact surface model used in simulations improves the fit to measurements. In addition, the electric field across the nitride causes charge to build up in the nitride, increasing the measured capacitance over time. The rate of charging corresponds to charge injection through direct tunneling. A novel actuator that can travel stably beyond one-third of the initial gap (a trademark limitation of

  15. PUBLISHER'S ANNOUNCEMENT: A revised scope for Journal of Micromechanics and Microengineering A revised scope for Journal of Micromechanics and Microengineering

    NASA Astrophysics Data System (ADS)

    Forbes, Ian

    2010-05-01

    Journal of Micromechanics and Microengineering is well known for publishing excellent work in highly competitive timescales. The journal's coverage has consistently evolved to reflect the current state of the field, and from May 2010 it will revisit its scope once again. The aims of the journal remain unchanged, however: to be the first choice of authors and readers in MEMS and micro-scale research. The new scope continues to focus on highlighting the link between fabrication technologies and their capacity to create novel devices. This link will be considered paramount in the journal, and both prospective authors and readers should let it serve as an inspiration to them. The burgeoning fields of NEMS and nano-scale engineering are more explicitly supported in the new scope. Research which ten years ago would have been considered science fiction has, through the tireless efforts of the community, become reality. The Editorial Board feel it is important to reflect the growing significance of this work in the scope. The new scope, drafted by Editor-in-Chief Professor Mark Allen, and approved by the Editorial Board, is as follows: Journal of Micromechanics and Microengineering covers all aspects of microelectromechanical structures, devices, and systems, as well as micromechanics and micromechatronics. The journal focuses on original work in fabrication and integration technologies, on the micro- and nano-scale. The journal aims to highlight the link between new fabrication technologies and their capacity to create novel devices. Original work in microengineering and nanoengineering is also reported. Such work is defined as applications of these fabrication and integration technologies to structures in which key attributes of the devices or systems depend on specific micro- or nano-scale features. Such applications span the physical, chemical, electrical and biological realms. New fabrication and integration techniques for both silicon and non-silicon materials are

  16. Southern Europe

    NASA Technical Reports Server (NTRS)

    2002-01-01

    On November 3, 2001, MODIS collected this image of Western Europe. Starting at the lower-left corner of the image and moving clockwise are the countries of Spain, France, Germany, Austria, Italy, and Switzerland. The Alps, the crescent-shaped mountain range running from the center to the right side of the image, span a length of 750 miles and cover and area of 80,000 square miles. In this image, a gray cloud of aerosols, predominantly from Italy's northwestern region of Lombardy, are corralled by the massive heights of the Alps. One large source of aerosols is the city of Milan. Home to numerous international and local industrial plants, Milan is faced with many of the same air quality problems as other large metropolitan areas. Also visible in the image is a phytoplankton bloom in the Bay of Biscay (left), at the confluence of the Garonne and Dordogne rivers. The rivers form the Gironde Estuary, which is saturated with sediment that provides necessary nutrients for the phytoplankton. Image courtesy Jacques Descloitres, MODIS Land Rapid Response Team at NASA GSFC

  17. Apparatus and method for detecting electromagnetic radiation using electron photoemission in a micromechanical sensor

    DOEpatents

    Datskos, Panagiotis G.; Rajic, Slobodan; Datskou, Irene C.; Egert, Charles M.

    2002-01-01

    A micromechanical sensor and method for detecting electromagnetic radiation involve producing photoelectrons from a metal surface in contact with a semiconductor. The photoelectrons are extracted into the semiconductor, which causes photo-induced bending. The resulting bending is measured, and a signal corresponding to the measured bending is generated and processed. A plurality of individual micromechanical sensors can be arranged in a two-dimensional matrix for imaging applications.

  18. Annual AFOSR Chemistry Program Review (19th)

    DTIC Science & Technology

    1974-01-01

    organomercury compounds. Through decomposition of C6HsHgCX 2 Cl (where X is chlorine, fluorine or bromine) he has obtained CX 2 intermediates which add...34Ground States of -bonded Molecules. XVII. Fluorine Compounds," M. J. S. Dewar and D. H. Lo, J. Amer. Chem. Soc., 94, 15, 5296 (1972). "Ground...B. T. Nakata, and J. D. Park, J. Fluorine Chem., 1, 235 (1971). "Free-Radical Reactions of Silanes with 1,2-Dihalopolyfluorocycloalkenes," J. D. Park

  19. 19th Annual Residence Hall Construction Report

    ERIC Educational Resources Information Center

    Agron, Joe

    2008-01-01

    The construction of residence hall facilities at colleges and universities continues to be strong, as institutions scramble to meet the housing needs and varied demands of a growing student population. This article presents data collected from 39 new residence hall projects completed in 2007. According to American School & University's 19th…

  20. Micromechanical analysis of constitutive properties of active piezoelectric structural fiber (PSF) composites

    NASA Astrophysics Data System (ADS)

    Ng, Kenny; Dai, Qingli

    2011-04-01

    Recent studies showed that the active piezoelectric structural fiber (PSF) composites may achieve significant and simultaneous improvements in sensing/actuating, stiffness, fracture toughness and vibration damping. These characteristics can be very important in the application of civil, mechanical and aerospace structures. The PSF is fabricated by coating the piezoceramic onto the silicon carbide core fiber with electrophoretic deposition (EPD) process to overcome the fragile nature of the monolithic piezoelectric materials. The PSF composite laminates are made of longitudinally poled PSFs that are unidirectionally deployed in the polymer binding matrix. The PSF laminate transducer has electrical inputs/outputs that are delivered through a separate etched interdigital electrode layer. This study analyzed the electromechanical properties with the generalized dilute scheme for active PSF composite laminate by considering multiinclusions. The well-known Mori-Tanaka approach was used to evaluate the concentration tensor in the multi-inclusion micromechanics model. To accurately predict the transverse properties, the extended role of mixtures were applied by considering the inclusions' geometry and shape. The micromechanical finite element modeling was also conducted with representative volume element (RVE) to compare with the micromechanics analysis on the electromechanical properties. The micromechanics analysis and finite element micromechanical modeling were conducted with varied fiber geometry dimensions and volume fractions. These comparison studies indicate the combined micromechanics models with the generalized dilute scheme can effectively predict the electro-elastic properties of multi-inclusion PSF composites.

  1. Characterization of the embedded micromechanical device approach to the monolithic integration of MEMS with CMOS

    SciTech Connect

    Smith, J.H.; Montague, S.; Sniegowski, J.J.; Murray, J.R.

    1996-10-01

    Recently, a great deal of interest has developed in manufacturing processes that allow the monolithic integration of MicroElectroMechanical Systems (MEMS) with driving, controlling, and signal processing electronics. This integration promises to improve the performance of micromechanical devices as well as lower the cost of manufacturing, packaging, and instrumenting these devices by combining the micromechanical devices with a electronic devices in the same manufacturing and packaging process. In order to maintain modularity and overcome some of the manufacturing challenges of the CMOS-first approach to integration, we have developed a MEMS-first process. This process places the micromechanical devices in a shallow trench, planarizes the wafer, and seals the micromechanical devices in the trench. Then, a high-temperature anneal is performed after the devices are embedded in the trench prior to microelectronics processing. This anneal stress-relieves the micromechanical polysilicon and ensures that the subsequent thermal processing associated with fabrication of the microelectronic processing does not adversely affect the mechanical properties of the polysilicon structures. These wafers with the completed, planarized micromechanical devices are then used as starting material for conventional CMOS processes. The circuit yield for the process has exceeded 98%. A description of the integration technology, the refinements to the technology, and wafer-scale parametric measurements of device characteristics is presented. Additionally, the performance of integrated sensing devices built using this technology is presented.

  2. Attenuated Total Reflection Fourier Transform Infrared (ATR FT-IR) Spectroscopy as a Forensic Method to Determine the Composition of Inks Used to Print the United States One-cent Blue Benjamin Franklin Postage Stamps of the 19th Century.

    PubMed

    Brittain, Harry G

    2016-01-01

    Through the combined use of infrared (IR) absorption spectroscopy and attenuated total reflectance (ATR) sampling, the composition of inks used to print the many different types of one-cent Benjamin Franklin stamps of the 19th century has been established. This information permits a historical evaluation of the formulations used at various times, and also facilitates the differentiation of the various stamps from each other. In two instances, the ink composition permits the unambiguous identification of stamps whose appearance is identical, and which (until now) have only been differentiated through estimates of the degree of hardness or softness of the stamp paper, or through the presence or absence of a watermark in the paper. In these instances, the use of ATR Fourier transform infrared spectroscopy (FT-IR) spectroscopy effectively renders irrelevant two 100-year-old practices of stamp identification. Furthermore, since the use of ATR sampling makes it possible to obtain the spectrum of a stamp still attached to its cover, it is no longer necessary to identify these blue Franklin stamps using their cancellation dates.

  3. Micromechanics of Seismic Wave Propagation in Granular Rocks

    NASA Astrophysics Data System (ADS)

    Nihei, Kurt Toshimi

    1992-09-01

    This thesis investigates the details of seismic wave propagation in granular rocks by examining the micromechanical processes which take place at the grain level. Grain contacts are identified as the primary sites of attenuation in dry and fluid-saturated rocks. In many sedimentary rocks such as sandstones and limestones, the process of diagenesis leaves the grains only partially cemented together. When viewed at the micron scale, grain contacts are non-welded interfaces similar in nature to large scale joints and faults. Using a lumped properties approximation, the macroscopic properties of partially cemented grain contacts are modeled using a displacement-discontinuity boundary condition. This model is used to estimate the magnitude and the frequency dependence of the grain contact scattering attenuation for an idealized grain packing geometry. Ultrasonic P- and S-wave group velocity and attenuation measurements on sintered glass beads, alundum, and Berea sandstones were performed to determine the effects of stress, frequency, and pore fluid properties in granular materials with sintered and partially sintered grain contacts. P - and S-wave attenuation displayed the same overall trends for tests with n-decane, water, silicone oil, and glycerol. The magnitudes of the attenuation coefficients were, in general, higher for S-waves. The experimental measurements reveal that viscosity-dependent attenuation dominates in material with sintered grain contacts. Viscosity-dependent attenuation is also observed in Berea sandstone but only at hydrostatic stresses in excess of 15 MPa where the grain contacts are highly stiffened. Fluid surface chemistry-related attenuation was observed in Berea sandstone loaded uniaxially. These measurements suggest that attenuation in fluid-saturated rocks with partially cemented grain contacts is dependent on both the fluid properties and the state of stress at the grain contacts. A numerical method for simulating seismic wave propagation in

  4. An integrated micromechanical large particle in flow sorter (MILPIS)

    NASA Astrophysics Data System (ADS)

    Fuad, Nurul M.; Skommer, Joanna; Friedrich, Timo; Kaslin, Jan; Wlodkowic, Donald

    2015-06-01

    At present, the major hurdle to widespread deployment of zebrafish embryo and larvae in large-scale drug development projects is lack of enabling high-throughput analytical platforms. In order to spearhead drug discovery with the use of zebrafish as a model, platforms need to integrate automated pre-test sorting of organisms (to ensure quality control and standardization) and their in-test positioning (suitable for high-content imaging) with modules for flexible drug delivery. The major obstacle hampering sorting of millimetre sized particles such as zebrafish embryos on chip-based devices is their substantial diameter (above one millimetre), mass (above one milligram), which both lead to rapid gravitational-induced sedimentation and high inertial forces. Manual procedures associated with sorting hundreds of embryos are very monotonous and as such prone to significant analytical errors due to operator's fatigue. In this work, we present an innovative design of a micromechanical large particle in-flow sorter (MILPIS) capable of analysing, sorting and dispensing living zebrafish embryos for drug discovery applications. The system consisted of a microfluidic network, revolving micromechanical receptacle actuated by robotic servomotor and opto-electronic sensing module. The prototypes were fabricated in poly(methyl methacrylate) (PMMA) transparent thermoplastic using infrared laser micromachining. Elements of MILPIS were also fabricated in an optically transparent VisiJet resin using 3D stereolithography (SLA) processes (ProJet 7000HD, 3D Systems). The device operation was based on a rapidly revolving miniaturized mechanical receptacle. The latter function was to hold and position individual fish embryos for (i) interrogation, (ii) sorting decision-making and (iii) physical sorting..The system was designed to separate between fertilized (LIVE) and non-fertilized (DEAD) eggs, based on optical transparency using infrared (IR) emitters and receivers embedded in the system

  5. Clear cutting (10-13th century) and deep stable economy (18-19th century) as responsible interventions for sand drifting and plaggic deposition in cultural landscapes on aeolian sands (SE-Netherlands).

    NASA Astrophysics Data System (ADS)

    van Mourik, Jan; Vera, Hein; Wallinga, Jakob

    2013-04-01

    landscapes, characterized by deflation plains (gleyic arenosols) and complexes of inland dunes (haplic arenosols). Clear cutting was responsible for the mediaeval first large scale expansion of drift sand landscapes. In such driftsand landscapes, the majority of the podzolic soils in coversand has been truncated by aeolian erosion. Only on scattered sheltered sites in the landscape, palaeopodzols were buried under mono or polycyclic driftsand deposits. They are now the valuable soil archives for palaeoecological research. During the 18th century, the population growth and regional economic activity stimulated the agricultural productivity. Farmers introduced the innovative 'deep stable' technique to increase the production of fertilizers. Farmers started sod digging, including the top of the Ah horizon of the humus forms. This consequently promoted heath degradation and sand drifting, resulting in the extension of driftsand landscapes. Deep stable economy and sod digging was responsible for the 18th century second large scale expansion of drift sand landscapes. During the 19th century, farmers tried to find alternative fertilizers and authorities initiated reforestation projects. The invention of chemical fertilizers at the end of the 19th century marked the end of the period of heath management and plaggic agriculture. The heath was no longer used for the harvesting of plaggic matter and new land management practices were introduced. Heath was reclaimed to new arable land or reforested with Scotch pine. Geomorphological features as inland dunes and plaggic covers survived in the landscape and are now included in the geological inheritance.

  6. [Changes of medico-pharmaceutical profession and private practice from the late 19th century to the early 20th century: ebb and flow of western pharmacies and clinics attached to pharmacy].

    PubMed

    Lee, Heung-Ki

    2010-12-31

    This article examined i) how traditional medico-pharmaceutical custom from the late 19th century influenced such changes, ii) how medical laws of Daehan Empire and early colonial period influenced the differentiation of medico-pharmaceutical profession, and iii) what the responses of medico-pharmaceutical professionals were like, and arrived at following conclusions. First, in late Chosun, there was a nationwide spread of pharmacies (medicine room, medicine store) as general medical institutions in charge of prescription and medication as well as diagnosis. Therefore, Koreans' perception of Western medicine was not very different from that of traditional pharmacy. Second, Western pharmacies were established by various entities including oriental doctors, Western doctors and drug manufacturers.Their business ranged from medical consultation, prescription, medication and drug manufacture. This was in a way the extension of traditional medico-pharmaceutical custom, which did not draw a sharp line between medical and pharmaceutical practices. Also, regulations on medical and pharmaceutical business of Daehan Empire did not distinguish oriental and Western medicine. Third, clinics attached to pharmacy began to emerge after 1908, as some Western pharmacies that had grown their business based on selling medicine began to hire doctors trained in Western medicine. This trend resulted from Government General's control over medico-pharmaceutical business that began in 1908, following a large-scale dismissal of army surgeons trained in medical schools in 1907. Fourth, as specialization increased within medico-pharmaceutical business following the colonial medical law in early 1910s, such comprehensive business practices as Western pharmacy disappeared and existing businesses were differentiated into dealers of medical ingredients, drug manufacturer, patent medicine businessmen and herbalists. And private practice gradually became the general trend by establishment of medical

  7. Failure Criterion for Brick Masonry: A Micro-Mechanics Approach

    NASA Astrophysics Data System (ADS)

    Kawa, Marek

    2015-02-01

    The paper deals with the formulation of failure criterion for an in-plane loaded masonry. Using micro-mechanics approach the strength estimation for masonry microstructure with constituents obeying the Drucker-Prager criterion is determined numerically. The procedure invokes lower bound analysis: for assumed stress fields constructed within masonry periodic cell critical load is obtained as a solution of constrained optimization problem. The analysis is carried out for many different loading conditions at different orientations of bed joints. The performance of the approach is verified against solutions obtained for corresponding layered and block microstructures, which provides the upper and lower strength bounds for masonry microstructure, respectively. Subsequently, a phenomenological anisotropic strength criterion for masonry microstructure is proposed. The criterion has a form of conjunction of Jaeger critical plane condition and Tsai-Wu criterion. The model proposed is identified based on the fitting of numerical results obtained from the microstructural analysis. Identified criterion is then verified against results obtained for different loading orientations. It appears that strength of masonry microstructure can be satisfactorily described by the criterion proposed.

  8. Shepherding intrinsic localized modes in micro-mechanical arrays

    NASA Astrophysics Data System (ADS)

    Sievers, Albert

    The energy profiles of intrinsic localized modes (ILMs) in periodic physical lattices with nonlinear forces resemble those of localized vibrational modes at defects in a harmonic lattice but, like solitons, they can propagate; however, in contrast with solitons they loose energy as they move through the lattice - the more localized the excitation the faster the energy loss. One of our experimental studies with micro-mechanical arrays involves steady state locking of ILMs, and their interactions with impurities. By measuring the linear response spectra of a driven array containing an ILM both the dynamics of bifurcation transitions and the hopping of vibrational energy have been connected to the transition properties of soft modes. Recently the search for a completely mobile ILM has focused attention on minimizing the resonance interaction that occurs between the localized excitation and small amplitude plane wave modes. Via simulations we demonstrate that when more than one type of nonlinear force is present their Fourier components can often be designed to cancel against each other in the k-space region of the plane wave dispersion curve, removing the resonance. The end result is super-transmission for an ILM in a discrete physical lattice. Such an engineered, intrinsic, low loss channel may prove to be a useful property for other physical systems treated within a tight binding approximation. In collaboration with M. Sato.

  9. High-Fidelity Micromechanics Model Enhanced for Multiphase Particulate Materials

    NASA Technical Reports Server (NTRS)

    Pindera, Marek-Jerzy; Arnold, Steven M.

    2003-01-01

    This 3-year effort involves the development of a comprehensive micromechanics model and a related computer code, capable of accurately estimating both the average response and the local stress and strain fields in the individual phases, assuming both elastic and inelastic behavior. During the first year (fiscal year 2001) of the investigation, a version of the model called the High-Fidelity Generalized Method of Cells (HFGMC) was successfully completed for the thermo-inelastic response of continuously reinforced multiphased materials with arbitrary periodic microstructures (refs. 1 and 2). The model s excellent predictive capability for both the macroscopic response and the microlevel stress and strain fields was demonstrated through comparison with exact analytical and finite element solutions. This year, HFGMC was further extended in two technologically significant ways. The first enhancement entailed the incorporation of fiber/matrix debonding capability into the two-dimensional version of HFGMC for modeling the response of unidirectionally reinforced composites such as titanium matrix composites, which exhibit poor fiber/matrix bond. Comparison with experimental data validated the model s predictive capability. The second enhancement entailed further generalization of HFGMC to three dimensions to enable modeling the response of particulate-reinforced (discontinuous) composites in the elastic material behavior domain. Next year, the three-dimensional version will be generalized to encompass inelastic effects due to plasticity, viscoplasticity, and damage, as well as coupled electromagnetothermomechanical (including piezoelectric) effects.

  10. Micromechanical model of crack growth in fiber reinforced brittle materials

    NASA Technical Reports Server (NTRS)

    Rubinstein, Asher A.; Xu, Kang

    1990-01-01

    A model based on the micromechanical mechanism of crack growth resistance in fiber reinforced ceramics is presented. The formulation of the model is based on a small scale geometry of a macrocrack with a bridging zone, the process zone, which governs the resistance mechanism. The effect of high toughness of the fibers in retardation of the crack advance, and the significance of the fiber pullout mechanism on the crack growth resistance, are reflected in this model. The model allows one to address issues such as influence of fiber spacing, fiber flexibility, and fiber matrix friction. Two approaches were used. One represents the fracture initiation and concentrated on the development of the first microcracks between fibers. An exact closed form solution was obtained for this case. The second case deals with the development of an array of microcracks between fibers forming the bridging zone. An implicit exact solution is formed for this case. In both cases, a discrete fiber distribution is incorporated into the solution.

  11. Micromechanics of intergranular creep failure under cyclic loading

    SciTech Connect

    Giessen, E. van der; Tvergaard, V.

    1996-07-01

    This paper is concerned with a micromechanical investigation of intergranular creep failure caused by grain boundary cavitation under strain-controlled cyclic loading conditions. Numerical unit cell analyses are carried out for a planar polycrystal model in which the grain material and the grain boundaries are modeled individually. The model incorporates power-law creep of the grains, viscous grain boundary sliding between grains as well as the nucleation and growth of grain boundary cavities until they coalesce and form microcracks. Study of a limiting case with a facet-size microcrack reveals a relatively simple phenomenology under either balanced loading, slow-fast loading or balanced loading with a hold period at constant tensile stress. Next, a (non-dimensionalized) parametric study is carried out which focuses on the effect of the diffusive cavity growth rate relative to the overall creep rate, and the effects of cavity nucleation and grain boundary sliding. The model takes account of the build up of residual stresses during cycling, and it turns out that this, in general, gives rise to a rather complex phenomenology, but some cases are identified which approach the simple microcrack behavior. The analyses provide some new understanding that helps to explain the sometimes peculiar behavior under balanced cyclic creep.

  12. Micromechanical-biochemical studies of mitotic chromosome elasticity and structure

    NASA Astrophysics Data System (ADS)

    Poirier, Michael Guy

    The structure of mitotic chromosomes was studied by combining micromechanical force measurements with microfluidic biochemical exposures. Our method is to use glass micropipettes attached to either end of a single chromosome to do mechanical experiments in the extracellular buffer. A third pipette can be used to locally 'spray' reactants so as to carry out dynamical mechanical-chemical experiments. The following elastic properties of mitotic chromosomes are found: Young's modulus, Y = 300 Pa; Poisson ratio, sigma = 0.1; Bending rigidity, B = 1 x 10 -22 J·m; Internal viscosity, eta' = 100 kg/m·sec; Volume fraction, ϕ = 0.7; Extensions of less than 3 times the relaxed length are linear and reversible; Extensions beyond 30 fold exhibit a force plateau at 15 nN and convert the chromosome to a disperse ghost-like state with little change in chromatin structure; Mitotic chromosomes are relatively isotropic; dsDNA cuts of at least every 3 kb cause the a mitotic chromosomes to fall apart; dsDNA cuts less frequently than every 50 kb do not affect mitotic chromosome structure. These results lead to the conclusion that mitotic chromosomes are a network crosslinked every 50 kb between which chromatin is fold by chromatin folding proteins, which are likely to be condensins.

  13. Micromechanical Characterization of Polysilicon Films through On-Chip Tests

    PubMed Central

    Mirzazadeh, Ramin; Eftekhar Azam, Saeed; Mariani, Stefano

    2016-01-01

    When the dimensions of polycrystalline structures become comparable to the average grain size, some reliability issues can be reported for the moving parts of inertial microelectromechanical systems (MEMS). Not only the overall behavior of the device turns out to be affected by a large scattering, but also the sensitivity to imperfections gets enhanced. In this work, through on-chip tests, we experimentally investigate the behavior of thin polysilicon samples using standard electrostatic actuation/sensing. The discrepancy between the target and actual responses of each sample has then been exploited to identify: (i) the overall stiffness of the film and, according to standard continuum elasticity, a morphology-based value of its Young’s modulus; (ii) the relevant over-etch induced by the fabrication process. To properly account for the aforementioned stochastic features at the micro-scale, the identification procedure has been based on particle filtering. A simple analytical reduced-order model of the moving structure has been also developed to account for the nonlinearities in the electrical field, up to pull-in. Results are reported for a set of ten film samples of constant slenderness, and the effects of different actuation mechanisms on the identified micromechanical features are thoroughly discussed. PMID:27483268

  14. Micromechanical study of protein-DNA interactions and chromosomes

    NASA Astrophysics Data System (ADS)

    Marko, John

    I will discuss micromechanics experiments that our group has used to analyze protein-DNA interactions and chromosome organization. In single-DNA experiments we have found that a feature of protein-DNA complexes is that their dissociation rates can depend strikingly on bulk solution concentrations of other proteins and DNA segments; I will describe experiments which demonstrate this effect, which can involve tens-fold changes in off-rates with submicromolar changes in solution concentrations. Second, I will discuss experiments aimed at analyzing large-scale human chromosome structure; we isolate metaphase chromosomes, which in their native form behave as remarkably elastic networks of chromatin. Exposure to DNA-cutting restriction enzymes completely eliminates this elasticity, indicating that there is not a mechanically contiguous protein ''scaffold'' from which the chromosome gains its stability. I will show results of siRNA experiments indicating that depletion of condensin proteins leads to destabilization of chromosome mechanics, indicating condensin's role as the major chromatin ''cross-linker'' in metaphase chromosomes. Finally I will discuss similar experiments on human G1 nuclei, where we use genetic and chemical modifications to separate the contributions of the nuclear lamina and chromatin to the mechanical stiffness of the nucleus as a whole. Supported by the NSF (DMR-1206868, MCB-1022117) and the NIH (GM105847, CA193419).

  15. Micromechanical model for isolated polymer-colloid clusters under tension

    NASA Astrophysics Data System (ADS)

    Dargazany, Roozbeh; Lin, Jiaqi; Khalili, Leila; Itskov, Mikhail; Chen, Hsieh; Alexander-Katz, Alfredo

    2016-10-01

    Binary polymer-colloid (PC) composites form the majority of biological load-bearing materials. Due to the abundance of the polymer and particles, and their simple aggregation process, PC clusters are used broadly by nature to create biomaterials with a variety of functions. However, our understanding of the mechanical features of the clusters and their load transfer mechanism is limited. Our main focus in this paper is the elastic behavior of close-packed PC clusters formed in the presence of polymer linkers. Therefore, a micromechanical model is proposed to predict the constitutive behavior of isolated polymer-colloid clusters under tension. The mechanical response of a cluster is considered to be governed by a backbone chain, which is the stress path that transfers most of the applied load. The developed model can reproduce the mean behavior of the clusters and is not dependent on their local geometry. The model utilizes four geometrical parameters for defining six shape descriptor functions which can affect the geometrical change of the clusters in the course of deformation. The predictions of the model are benchmarked against an extensive set of simulations by coarse-grained-Brownian dynamics, where clusters with different shapes and sizes were considered. The model exhibits good agreement with these simulations, which, besides its relative simplicity, makes the model an excellent add-on module for implementation into multiscale models of nanocomposites.

  16. Active microrheology of a model of the nuclear micromechanical environment

    NASA Astrophysics Data System (ADS)

    Byrd, Henry; Kilfoil, Maria

    2014-03-01

    In order to successfully complete the final stages of chromosome segregation, eukaryotic cells require the motor enzyme topoisomerase II, which can resolve topological constraints between entangled strands of duplex DNA. We created an in vitro model of a close approximation of the nuclear micromechanical environment in terms of DNA mass and entanglement density, and investigated the influence of this motor enzyme on the DNA mechanics. Topoisomerase II is a non-processive ATPase which we found significantly increases the motions of embedded microspheres in the DNA network. Because of this activity, we study the mechanical properties of our model system by active microrheology by optical trapping. We test the limits of fluctuation dissipation theorem (FDT) under this type of activity by comparing the active microrheology to passive measurements, where thermal motion alone drives the beads. We can relate any departure from FDT to the timescale of topoisomerase II activity in the DNA network. These experiments provide insight into the physical necessity of this motor enzyme in the cell.

  17. Hybrid circuit cavity quantum electrodynamics with a micromechanical resonator.

    PubMed

    Pirkkalainen, J-M; Cho, S U; Li, Jian; Paraoanu, G S; Hakonen, P J; Sillanpää, M A

    2013-02-14

    Hybrid quantum systems with inherently distinct degrees of freedom have a key role in many physical phenomena. Well-known examples include cavity quantum electrodynamics, trapped ions, and electrons and phonons in the solid state. In those systems, strong coupling makes the constituents lose their individual character and form dressed states, which represent a collective form of dynamics. As well as having fundamental importance, hybrid systems also have practical applications, notably in the emerging field of quantum information control. A promising approach is to combine long-lived atomic states with the accessible electrical degrees of freedom in superconducting cavities and quantum bits (qubits). Here we integrate circuit cavity quantum electrodynamics with phonons. Apart from coupling to a microwave cavity, our superconducting transmon qubit, consisting of tunnel junctions and a capacitor, interacts with a phonon mode in a micromechanical resonator, and thus acts like an atom coupled to two different cavities. We measure the phonon Stark shift, as well as the splitting of the qubit spectral line into motional sidebands, which feature transitions between the dressed electromechanical states. In the time domain, we observe coherent conversion of qubit excitation to phonons as sideband Rabi oscillations. This is a model system with potential for a quantum interface, which may allow for storage of quantum information in long-lived phonon states, coupling to optical photons or for investigations of strongly coupled quantum systems near the classical limit.

  18. Characterizing Random Telegraph Frequency Noise in a Micromechanical Oscillator

    NASA Astrophysics Data System (ADS)

    Sun, Fengpei; Zou, Jie; Maizelis, Zakhar; Chan, Ho Bun

    2014-03-01

    We perform a comprehensive study of the effect of random telegraph frequency noise(RTFN) on a micromechanical torsional oscillator. A sinusoidal driving voltage is applied to one electrode of the oscillator to excite its torsional vibration. Telegraph noise is applied to the other electrode so that the eigenfrequency of the oscillator randomly jumps back and forth between two states. This arrangement resembles a mechanical oscillator dispersively coupled to a classical or quantum two-level system. As the jumping rate of the eigenfrequency is increased, the two peaks in the spectrum of the time-averaged vibration amplitude merge into a single peak, displaying spectral broadening followed by motional narrowing. Furthermore, we analyze the ratios of the moments of the complex vibration amplitude to the powers of the averaged complex amplitude as a function of the driving frequency. If RTFN is absent, the ratios are equal to one; otherwise they deviate from one near resonance and approach to one far off resonance. The shape of the spectra depends strongly on the characteristics of RTFN and this dependence remains valid even in the presence of strong thermal or detector noise. Our results are in good agreement with theoretical predictions.

  19. Effects of coiling on the micromechanics of the mammalian cochlea

    PubMed Central

    Cai, Hongxue; Manoussaki, Daphne; Chadwick, Richard

    2005-01-01

    The cochlea transduces sound-induced vibrations in the inner ear into electrical signals in the auditory nerve via complex fluid–structure interactions. The mammalian cochlea is a spiral-shaped organ, which is often uncoiled for cochlear modelling. In those few studies where coiling has been considered, the cochlear partition was often reduced to the basilar membrane only. Here, we extend our recently developed hybrid analytical/numerical micromechanics model to include curvature effects, which were previously ignored. We also use a realistic cross-section geometry, including the tectorial membrane and cellular structures of the organ of Corti, to model the apical and basal regions of a guinea-pig cochlea. We formulate the governing equations of the fluid and solid domains in a curvilinear coordinate system. The WKB perturbation method is used to treat the propagation of travelling waves along the coiled cochlear duct, and the O(1) system of the governing equations is solved in the transverse plane using finite-element analysis. We find that the curvature of the cochlear geometry has an important functional significance; at the apex, it greatly increases the shear gain of the cochlear partition, which is a measure of the bending efficiency of the outer hair cell stereocilia. PMID:16849192

  20. Micromechanical cohesion force measurements to determine cyclopentane hydrate interfacial properties.

    PubMed

    Aman, Zachary M; Joshi, Sanjeev E; Sloan, E Dendy; Sum, Amadeu K; Koh, Carolyn A

    2012-06-15

    Hydrate aggregation and deposition are critical factors in determining where and when hydrates may plug a deepwater flowline. We present the first direct measurement of structure II (cyclopentane) hydrate cohesive forces in the water, liquid hydrocarbon and gas bulk phases. For fully annealed hydrate particles, gas phase cohesive forces were approximately twice that obtained in a liquid hydrocarbon phase, and approximately six times that obtained in the water phase. Direct measurements show that hydrate cohesion force in a water-continuous bulk may be only the product of solid-solid cohesion. When excess water was present on the hydrate surface, gas phase cohesive forces increased by a factor of three, suggesting the importance of the liquid or quasi-liquid layer (QLL) in determining cohesive force. Hydrate-steel adhesion force measurements show that, when the steel surface is coated with hydrophobic wax, forces decrease up to 96%. As the micromechanical force technique is uniquely capable of measuring hydrate-surface forces with variable contact time, the present work contains significant implications for hydrate applications in flow assurance.

  1. Micromechanical anisotropy and heterogeneity of the meniscus extracellular matrix.

    PubMed

    Li, Qing; Qu, Feini; Han, Biao; Wang, Chao; Li, Hao; Mauck, Robert L; Han, Lin

    2017-02-27

    To understand how the complex biomechanical functions of the meniscus are endowed by the nanostructure of its extracellular matrix (ECM), we studied the anisotropy and heterogeneity in the micromechanical properties of the meniscus ECM. We used atomic force microscopy (AFM) to quantify the time-dependent mechanical properties of juvenile bovine meniscus at deformation length scales corresponding to the diameters of collagen fibrils. At this scale, anisotropy in the elastic modulus of the circumferential fibers, the major ECM structural unit, can be attributed to differences in fibril deformation modes: uncrimping when normal to the fiber axis, and laterally constrained compression when parallel to the fiber axis. Heterogeneity among different structural units is mainly associated with their variations in microscale fiber orientation, while heterogeneity across anatomical zones is due to alterations in collagen fibril diameter and alignment at the nanoscale. Unlike the elastic modulus, the time-dependent properties are more homogeneous and isotropic throughout the ECM. These results enable a detailed understanding of the meniscus structure-mechanics at the nanoscale, and can serve as a benchmark for understanding meniscus biomechanical functions, documenting disease progression and designing tissue repair strategies.

  2. Advanced micromechanisms in a multi-level polysilicon technology

    SciTech Connect

    Rodgers, M.S.; Sniegowski, J.J.; Miller, S.L.; Barron, C.C.; McWhorter, P.J.

    1997-08-01

    Quad-level polysilicon surface micromachining technology, comprising three mechanical levels plus an electrical interconnect layer, is giving rise to a new generation of micro-electromechanical devices and assemblies. Enhanced components can not be produced through greater flexibility in fabrication and design. New levels of design complexity that include multi-level gears, single-attempt locks, and optical elements have recently been realized. Extensive utilization of the fourth layer of polysilicon differentiates these latter generation devices from their predecessors. This level of poly enables the fabrication of pin joints, linkage arms, hinges on moveable plates, and multi-level gear assemblies. The mechanical design aspects of these latest micromachines will be discussed with particular emphasis on a number of design aspects of these latest micromachines will be discussed with particular emphasis on a number of design modifications that improve the power, reliability, and smoothness of operation of the microengine. The microengine is the primary actuation mechanism that is being used to drive mirrors out of plane and rotate 1600-{mu}m diameter gears. Also discussed is the authors most advanced micromechanical system to date, a complex proof-of-concept batch-fabricated assembly that, upon transmitting the proper electrical code to a mechanical lock, permits the operation of a micro-optical shutter.

  3. Micromechanics of Brittle Creep Under Triaxial Loading Conditions

    NASA Astrophysics Data System (ADS)

    Meredith, P. G.; Brantut, N.; Baud, P.; Heap, M. J.

    2011-12-01

    In the upper crust, the chemical influence of pore water promotes time-dependent brittle deformation through sub-critical crack growth. Sub-critical crack growth allows rocks to deform and fail (i) at stresses far below their short-term failure strength, and (ii) even at constant applied stress ("brittle creep"). Here we provide a micromechanical model and experimental results describing time-dependent brittle creep of water-saturated granite under triaxial stress conditions. Macroscopic brittle creep is modeled on the basis of microcrack extension under compressive stresses due to sub-critical crack growth. The incremental strains due to the growth of microcracks in compression are derived from the sliding wing-crack model of Ashby and Sammis (1990). Crack length evolution is computed from Charles' law. The macroscopic strain and strain rates are then computed from the change in energy potential due to microcrack growth. They are non-linear, and compare well with complementary experimental results obtained on granite samples. Primary creep (decelerating strain) corresponds to decreasing crack growth rate , due to an initial decrease in stress intensity factor with increasing crack length in compression. Tertiary creep (accelerating strain as failure is approached) corresponds to an increase in crack growth rate due to crack interactions. Secondary creep with apparently constant strain rate arises as merely an inflexion between the two end-member phases.

  4. Computational micromechanical analysis of the representative volume element of bituminous composite materials

    NASA Astrophysics Data System (ADS)

    Ozer, Hasan; Ghauch, Ziad G.; Dhasmana, Heena; Al-Qadi, Imad L.

    2016-08-01

    Micromechanical computational modeling is used in this study to determine the smallest domain, or Representative Volume Element (RVE), that can be used to characterize the effective properties of composite materials such as Asphalt Concrete (AC). Computational Finite Element (FE) micromechanical modeling was coupled with digital image analysis of surface scans of AC specimens. Three mixtures with varying Nominal Maximum Aggregate Size (NMAS) of 4.75 mm, 12.5 mm, and 25 mm, were prepared for digital image analysis and computational micromechanical modeling. The effects of window size and phase modulus mismatch on the apparent viscoelastic response of the composite were numerically examined. A good agreement was observed in the RVE size predictions based on micromechanical computational modeling and image analysis. Micromechanical results indicated that a degradation in the matrix stiffness increases the corresponding RVE size. Statistical homogeneity was observed for window sizes equal to two to three times the NMAS. A model was presented for relating the degree of statistical homogeneity associated with each window size for materials with varying inclusion dimensions.

  5. How to write a history of Europe: Europe, Europes, Eurasia

    NASA Astrophysics Data System (ADS)

    Burke, Peter

    2006-05-01

    This article looks at the history of European culture from three angles, those of European uniqueness, European variety and European consciousness. The first section discusses the question of whether the fundamental unit of study, for cultural as well as economic historians, is not Eurasia. The second section is concerned with cultural divisions within Europe, with Europes in the plural. It asks whether it is more illuminating to distinguish two Europes (like Leopold von Ranke), or three (like Jeno Szucs), or even five (like Hugo Hassinger), and examine both centripetal and centrifugal forces in early modern history. The final section deals with the history of the idea of Europe, or more exactly with the rise of consciousness of being European, as it is revealed in early modern histories, geographies, journals and newspapers.

  6. Europe's Second Demographic Transition.

    ERIC Educational Resources Information Center

    van de Kaa, Dirk J.

    1987-01-01

    By 1985, fertility rates in Europe were below the replacement level of 2.1 births per woman in all but Albania, Ireland, Malta, Poland, and Turkey, following a steady decline from a 1965 postwar peak well above 2.5 in Northern, Western, and Southern Europe and an erratic trend from a lower level in Eastern Europe. Natural decrease (fewer births…

  7. Implementation of Fiber Substructuring Into Strain Rate Dependent Micromechanics Analysis of Polymer Matrix Composites

    NASA Technical Reports Server (NTRS)

    Goldberg, Robert K.

    2001-01-01

    A research program is in progress to develop strain rate dependent deformation and failure models for the analysis of polymer matrix composites subject to impact loads. Previously, strain rate dependent inelastic constitutive equations developed to model the polymer matrix were incorporated into a mechanics of materials based micromechanics method. In the current work, the micromechanics method is revised such that the composite unit cell is divided into a number of slices. Micromechanics equations are then developed for each slice, with laminate theory applied to determine the elastic properties, effective stresses and effective inelastic strains for the unit cell. Verification studies are conducted using two representative polymer matrix composites with a nonlinear, strain rate dependent deformation response. The computed results compare well to experimentally obtained values.

  8. Micromechanical Machining Processes and their Application to Aerospace Structures, Devices and Systems

    NASA Technical Reports Server (NTRS)

    Friedrich, Craig R.; Warrington, Robert O.

    1995-01-01

    Micromechanical machining processes are those micro fabrication techniques which directly remove work piece material by either a physical cutting tool or an energy process. These processes are direct and therefore they can help reduce the cost and time for prototype development of micro mechanical components and systems. This is especially true for aerospace applications where size and weight are critical, and reliability and the operating environment are an integral part of the design and development process. The micromechanical machining processes are rapidly being recognized as a complementary set of tools to traditional lithographic processes (such as LIGA) for the fabrication of micromechanical components. Worldwide efforts in the U.S., Germany, and Japan are leading to results which sometimes rival lithography at a fraction of the time and cost. Efforts to develop processes and systems specific to aerospace applications are well underway.

  9. A unique set of micromechanics equations for high temperature metal matrix composites

    NASA Technical Reports Server (NTRS)

    Hopkins, D. A.; Chamis, C. C.

    1985-01-01

    A unique set of micromechanic equations is presented for high temperature metal matrix composites. The set includes expressions to predict mechanical properties, thermal properties and constituent microstresses for the unidirectional fiber reinforced ply. The equations are derived based on a mechanics of materials formulation assuming a square array unit cell model of a single fiber, surrounding matrix and an interphase to account for the chemical reaction which commonly occurs between fiber and matrix. A three-dimensional finite element analysis was used to perform a preliminary validation of the equations. Excellent agreement between properties predicted using the micromechanics equations and properties simulated by the finite element analyses are demonstrated. Implementation of the micromechanics equations as part of an integrated computational capability for nonlinear structural analysis of high temperature multilayered fiber composites is illustrated.

  10. High Strain Rate Deformation Modeling of a Polymer Matrix Composite. Part 2; Composite Micromechanical Model

    NASA Technical Reports Server (NTRS)

    Goldberg, Robert K.; Stouffer, Donald C.

    1998-01-01

    Recently applications have exposed polymer matrix composite materials to very high strain rate loading conditions, requiring an ability to understand and predict the material behavior under these extreme conditions. In this second paper of a two part report, a three-dimensional composite micromechanical model is described which allows for the analysis of the rate dependent, nonlinear deformation response of a polymer matrix composite. Strain rate dependent inelastic constitutive equations utilized to model the deformation response of a polymer are implemented within the micromechanics method. The deformation response of two representative laminated carbon fiber reinforced composite materials with varying fiber orientation has been predicted using the described technique. The predicted results compare favorably to both experimental values and the response predicted by the Generalized Method of Cells, a well-established micromechanics analysis method.

  11. Implementation of Laminate Theory Into Strain Rate Dependent Micromechanics Analysis of Polymer Matrix Composites

    NASA Technical Reports Server (NTRS)

    Goldberg, Robert K.

    2000-01-01

    A research program is in progress to develop strain rate dependent deformation and failure models for the analysis of polymer matrix composites subject to impact loads. Previously, strain rate dependent inelastic constitutive equations developed to model the polymer matrix were implemented into a mechanics of materials based micromechanics method. In the current work, the computation of the effective inelastic strain in the micromechanics model was modified to fully incorporate the Poisson effect. The micromechanics equations were also combined with classical laminate theory to enable the analysis of symmetric multilayered laminates subject to in-plane loading. A quasi-incremental trapezoidal integration method was implemented to integrate the constitutive equations within the laminate theory. Verification studies were conducted using an AS4/PEEK composite using a variety of laminate configurations and strain rates. The predicted results compared well with experimentally obtained values.

  12. Micro-mechanical study of stress path and initial conditions in granular materials using DEM

    NASA Astrophysics Data System (ADS)

    Dorostkar, Omid; Mirghasemi, Ali Asghar

    2016-03-01

    The macroscale response of granular materials under different loading conditions stems from the alteration of micromechanical properties during loading. Previous studies have used either physical experiments or discrete element method simulations to explore the effect of initial conditions and stress path on granular materials. However, microscale studies are not sufficient, especially for various loading paths. We study micromechanics of granular materials using the stress-force-fabric (SFF) relationship for a better understanding of the behavior of granular materials. Triaxial compression and extension tests are conducted on samples containing 1000 spherical particles, with periodic boundaries, and the effect of initial porosity is studied. In the next step, using the SFF relationship, we study the effect of anisotropic consolidation ratio. In addition to providing an appropriate explanation for shear strength out of evolution of anisotropy coefficients, our results show that anisotropic consolidation does not affect the micromechanical properties of granular materials in a way to change mobilized friction angle of sample at failure point.

  13. A unique set of micromechanics equations for high-temperature metal matrix composites

    NASA Technical Reports Server (NTRS)

    Hopkins, Dale A.; Chamis, Christos C.

    1988-01-01

    A unique set of micromechanic equations is presented for high-temperature metal matrix composites. The set includes expressions to predict mechanical properties, thermal properties and constituent microstresses for the unidirectional fiber reinforced ply. The equations are derived based on a mechanics of materials formulation assuming a square array unit cell model of a single fiber, surrounding matrix and an interphase to account for the chemical reaction which commonly occurs between fiber and matrix. A three-dimensional finite element analysis was used to perform a preliminary validation of the equations. Excellent agreement between properties predicted using the micromechanics equations and properties simulated by the finite element analyses are demonstrated. Implementation of the micromechanics equations as part of an integrated computational capability for nonlinear structural analysis of high temperature multilayered fiber composites is illustrated.

  14. An anisotropic micromechanics model for predicting the rafting direction in Ni-based single crystal superalloys

    NASA Astrophysics Data System (ADS)

    Li, Shuang-Yu; Wu, Wen-Ping; Chen, Ming-Xiang

    2016-02-01

    An anisotropic micromechanics model based on the equivalent inclusion method is developed to investigate the rafting direction of Ni-based single crystal superalloys. The micromechanical model considers actual cubic structure and orthogonal anisotropy properties. The von Mises stress, elastic strain energy density, and hydrostatic pressure in different inclusions of micromechanical model are calculated when applying a tensile or compressive loading along the [001] direction. The calculated results can successfully predict the rafting direction for alloys exhibiting a positive or a negative mismatch, which are in agreement with pervious experimental and theoretical studies. Moreover, the elastic constant differences and mismatch degree of the matrix and precipitate phases and their influences on the rafting direction are carefully discussed.

  15. Micromechanical simulation of damage progression in carbon phenolic composites

    NASA Technical Reports Server (NTRS)

    Slattery, Kerry T.

    1993-01-01

    understanding of these macro damage mechanisms is that the loading environment and the material response to that environment are extremely complex. These types of damage are usually only observed in actual motor firings. Therefore, it is difficult and expensive to evaluate the reliability of new materials. Standard material tests which measure mechanical and thermal properties of test specimens can only provide a partial picture of how the material will respond in the service environment. The development of the ANALOG test procedure which can combine high heating rates and mechanical loads on a specimen will improve the understanding of the interactive effects of the various loads on the system. But a mechanistic model of material response which can account for the heterogeneity of the material, the progression of various micromechanical damage mechanisms, and the interaction of mechanical and thermal stresses on the material is required to accurately correlate material tests with response to service environments. A model based on fundamental damage mechanisms which is calibrated and verified under a variety of loading conditions will provide a general tool for predicting the response of rocket nozzles. The development of a micromechanical simulation technique was initiated and demonstrated to be effective for studying across-ply tensile failure of carbon/phenolic composites.

  16. Micromechanical combined stress analysis: MICSTRAN, a user manual

    NASA Technical Reports Server (NTRS)

    Naik, R. A.

    1992-01-01

    Composite materials are currently being used in aerospace and other applications. The ability to tailor the composite properties by the appropriate selection of its constituents, the fiber and matrix, is a major advantage of composite materials. The Micromechanical Combined Stress Analysis (MICSTRAN) code provides the materials engineer with a user-friendly personal computer (PC) based tool to calculate overall composite properties given the constituent fiber and matrix properties. To assess the ability of the composite to carry structural loads, the materials engineer also needs to calculate the internal stresses in the composite material. MICSTRAN is a simple tool to calculate such internal stresses with a composite ply under combined thermomechanical loading. It assumes that the fibers have a circular cross-section and are arranged either in a repeating square or diamond array pattern within a ply. It uses a classical elasticity solution technique that has been demonstrated to calculate accurate stress results. Input to the program consists of transversely isotropic fiber properties and isotropic matrix properties such as moduli, Poisson's ratios, coefficients of thermal expansion, and volume fraction. Output consists of overall thermoelastic constants and stresses. Stresses can be computed under the combined action of thermal, transverse, longitudinal, transverse shear, and longitudinal shear loadings. Stress output can be requested along the fiber-matrix interface, the model boundaries, circular arcs, or at user-specified points located anywhere in the model. The MICSTRAN program is Windows compatible and takes advantage of the Microsoft Windows graphical user interface which facilitates multitasking and extends memory access far beyond the limits imposed by the DOS operating system.

  17. Micromechanical properties and structural characterization of modern inarticulated brachiopod shells

    NASA Astrophysics Data System (ADS)

    Merkel, C.; Griesshaber, E.; Kelm, K.; Neuser, R.; Jordan, G.; Logan, A.; Mader, W.; Schmahl, W. W.

    2007-06-01

    We investigated micromechanical properties and ultrastructure of the shells of the modern brachiopod species Lingula anatina, Discinisca laevis, and Discradisca stella with scanning electron microscopy (SEM, EDX), transmission electron microscopy (TEM) and Vickers microhardness indentation analyses. The shells are composed of two distinct layers, an outer primary layer and an inner secondary layer. Except for the primary layer in Lingula anatina, which is composed entirely of organic matter, all other shell layers are laminated organic/inorganic composites. The organic matter is built of chitin fibers, which provide the matrix for the incorporation of calcium phosphate. Amorphous calcium phosphate in the outer, primary layer and crystalline apatite is deposited into the inner, secondary layer of the shell. Apatite crystallite sizes in the umbonal region of the shell are about 50 × 50 nm, while within the valves crystallite sizes are significantly smaller, averanging 10 × 25 nm. There is great variation in hardness values between shell layers and between the investigated brachiopod species. The microhardness of the investigated shells is significantly lower than that of inorganic hydroxyapatite. This is caused by the predominantly organic material component that in these shells is either developed as purely organic layers or as an organic fibrous matrix reinforced by crystallites. Our results show that this particular fiber composite material is very efficient for the protection and the support of the soft animal tissue. It lowers the probability of crack formation and effectively impedes crack propagation perpendicular to the shell by crack-deviation mechanisms. The high degree of mechanical stability and toughness is achieved by two design features. First, there is the fiber composite material which overcomes some detrimental and enhances some advantageous properties of the single constituents, that is the softness and flexibility of chitin and the hardness and

  18. Micromechanical design of hierarchical composites using global load sharing theory

    NASA Astrophysics Data System (ADS)

    Rajan, V. P.; Curtin, W. A.

    2016-05-01

    Hierarchical composites, embodied by natural materials ranging from bone to bamboo, may offer combinations of material properties inaccessible to conventional composites. Using global load sharing (GLS) theory, a well-established micromechanics model for composites, we develop accurate numerical and analytical predictions for the strength and toughness of hierarchical composites with arbitrary fiber geometries, fiber strengths, interface properties, and number of hierarchical levels, N. The model demonstrates that two key material properties at each hierarchical level-a characteristic strength and a characteristic fiber length-control the scalings of composite properties. One crucial finding is that short- and long-fiber composites behave radically differently. Long-fiber composites are significantly stronger than short-fiber composites, by a factor of 2N or more; they are also significantly tougher because their fiber breaks are bridged by smaller-scale fibers that dissipate additional energy. Indeed, an "infinite" fiber length appears to be optimal in hierarchical composites. However, at the highest level of the composite, long fibers localize on planes of pre-existing damage, and thus short fibers must be employed instead to achieve notch sensitivity and damage tolerance. We conclude by providing simple guidelines for microstructural design of hierarchical composites, including the selection of N, the fiber lengths, the ratio of length scales at successive hierarchical levels, the fiber volume fractions, and the desired properties of the smallest-scale reinforcement. Our model enables superior hierarchical composites to be designed in a rational way, without resorting either to numerical simulation or trial-and-error-based experimentation.

  19. Continuum modeling using granular micromechanics approach: Method development and applications

    NASA Astrophysics Data System (ADS)

    Poorsolhjouy, Payam

    This work presents a constitutive modeling approach for the behavior of granular materials. In the granular micromechanics approach presented here, the material point is assumed to be composed of grains interacting with their neighbors through different inter-granular mechanisms that represent material's macroscopic behavior. The present work focuses on (i) developing the method for modeling more complicated material systems as well as more complicated loading scenarios and (ii) applications of the method for modeling various granular materials and granular assemblies. A damage-plasticity model for modeling cementitious and rock-like materials is developed, calibrated, and verified in a thermo-mechanically consistent manner. Grain-pair interactions in normal tension, normal compression, and tangential directions have been defined in a manner that is consistent with the material's macroscopic behavior. The resulting model is able to predict, among other interesting issues, the effects of loading induced anisotropy. Material's response to loading will depend on the loading history of grain-pair interactions in different directions. Thus the model predicts load-path dependent failure. Due to the inadequacies of first gradient continuum theories in predicting phenomena such as shear band width, wave dispersion, and frequency band-gap, the presented method is enhanced by incorporation of non-classical terms in the kinematic analysis. A complete micromorphic theory is presented by incorporating additional terms such as fluctuations, second gradient terms, and spin fields. Relative deformation of grain-pairs is calculated based on the enhanced kinematic analysis. The resulting theory incorporates the deformation and forces in grain-pair interactions due to different kinematic measures into the macroscopic behavior. As a result, non-classical phenomena such as wave dispersion and frequency band-gaps can be predicted. Using the grain-scale analysis, a practical approach for

  20. Experimental Characterization and Micromechanical Modelling of Anisotropic Slates

    NASA Astrophysics Data System (ADS)

    Chen, Yi-Feng; Wei, Kai; Liu, Wu; Hu, Shao-Hua; Hu, Ran; Zhou, Chuang-Bing

    2016-09-01

    Laboratory tests were performed in this study to examine the anisotropic physical and mechanical properties of the well-foliated Jiujiang slate. The P-wave velocity and the apparent Young's modulus were found to increase remarkably with the foliation angle θ, and the compressive strength at any confining pressure varies in a typical U-shaped trend, with the maximum strength consistently attained at θ = 90° and the minimum strength at θ = 45°. The slate samples failed in three typical patterns relevant to the foliation angle, i.e. shear failure across foliation planes for θ ≤ 15°, sliding along foliation planes for 30° ≤ θ ≤ 60° and axial splitting along foliation planes for θ = 90°. The stress-strain curves at any given foliation angle and confining pressure display an initial nonlinear phase, a linear elastic phase, a crack initiation and growth phase, as well as a rapid stress drop phase and a residual stress phase. Based on the experimental evidences, a micromechanical damage-friction model was proposed for the foliated slate by simply modelling the foliation planes as a family of elastic interfaces and by characterizing the interaction between the foliation planes and the rock matrix with a nonlinear damage evolution law associated with the inclination angle. The proposed model was applied to predict the deformational and strength behaviours of the foliated slate under triaxial compressive conditions using the material parameters calibrated with the uniaxial and/or triaxial test data, with good agreement between the model predictions and the laboratory measurements.

  1. Highly sensitive devices for primary signal processing of the micromechanical capacitive transducers

    NASA Astrophysics Data System (ADS)

    Konoplev, B.; Ryndin, E.; Lysenko, I.; Denisenko, M.; Isaeva, A.

    2016-12-01

    A method of signal processing devices design for micromechanical accelerometers with capacitive transducers is proposed. This method provides the complex solution of the sensibility increasing and noise immunity problems by finding of the difference frequency of signals, which are formed by two identical generators with micromechanical capacitive transducers in frequency control circuits. In this study the analog and digital versions of the highly sensitive signal processing devices circuits with frequency output were developed. The breadboards of these devices are fabricated and studied and the project of their integral realization is designed.

  2. Using micromechanical resonators to measure rheological properties and alcohol content of model solutions and commercial beverages.

    PubMed

    Paxman, Rosemary; Stinson, Jake; Dejardin, Anna; McKendry, Rachel A; Hoogenboom, Bart W

    2012-01-01

    Micromechanic resonators provide a small-volume and potentially high-throughput method to determine rheological properties of fluids. Here we explore the accuracy in measuring mass density and viscosity of ethanol-water and glycerol-water model solutions, using a simple and easily implemented model to deduce the hydrodynamic effects on resonating cantilevers of various length-to-width aspect ratios. We next show that these measurements can be extended to determine the alcohol percentage of both model solutions and commercial beverages such as beer, wine and liquor. This demonstrates how micromechanical resonators can be used for quality control of every-day drinks.

  3. An integrated micromechanical and macromechanical approach to fracture behavior of fiber-reinforced composites

    NASA Technical Reports Server (NTRS)

    Mahishi, Jayant M.

    1986-01-01

    A novel integrated micromechanical and macromechanical fracture criterion (IMMFC) was developed for the purpose of characterizing fractures in fiber-reinforced composites. The Griffith energy balance equation was modified to include the energy absorption due to matrix yielding, matrix cracks, fiber breaks, and fiber-matrix interface debonds characteristic for these materials. Parameters which are a measure of the size and density of the microflaws are introduced into the development of the IMMFC, and the concept of the R-curve is used to bridge the micromechanics and macromechanics approaches.

  4. A three-variable chaotic system for the epidemic of bubonic plague in Bombay by the end of the 19th century and its coupling to the epizootics of the two main species of rats

    NASA Astrophysics Data System (ADS)

    Mangiarotti, Sylvain

    2016-04-01

    A plague epidemic broke out in Bombay by the end of the 19th century. A committee was first appointed by the Bombay City [1] in order to stop the epidemic before the rain season started. Unfortunately, the disease could not be stopped and the epidemic became endemic. After several years, another Advisory Committee [2] was appointed that tried to investigate the causes of plague in all possible directions. An impressing quantity of information was gathered during the period 1907-1911 and published. In particular, it was noticed that the epidemic was systematically preceded by epizootics of rats. For this reason, the populations of the main species of rodents were systematically monitored. This data set is revisited here by using a multivariate version of the global modeling technique [3]. The aim of this technique is to obtain a set of Ordinary Differential Equations directly from time series. Three observational time series are considered: the number of person died of bubonic plague per half month (1), and the number of captured infected black rats Mus rattus (2) and brown rats Mus decumanus (3). Several models are obtained, all based on the same algebraic basic structure. These models are, either directly chaotic, or close to chaos (chaos could easily be obtained by tuning one model parameter). The algebraic structure of the simplest model obtained is analyzed in more details. Surprisingly, it is found that the interpretation of the coupling between the three variables can be done term by term. This interpretation is in quite good coherence with the conclusions of the Advisory Committee published one hundred years ago. This structure also shows that the human action to slow down the disease during this period was obviously effective, although insufficient to stop the epidemic drastically. This result suggests that the global modeling technique can be a powerful tool to detect causal couplings in epidemiology, and, more generally, among observational variables from

  5. An extended micromechanics method for probing interphase properties in polymer nanocomposites [An extended micromechanics method for overlapping geometries with application to polymer nanocomposites

    SciTech Connect

    Liu, Zeliang; Moore, John A.; Liu, Wing Kam

    2016-05-03

    Inclusions comprised on filler particles and interphase regions commonly form complex morphologies in polymer nanocomposites. Addressing these morphologies as systems of overlapping simple shapes allows for the study of dilute particles, clustered particles, and interacting interphases all in one general modeling framework. To account for the material properties in these overlapping geometries, weighted-mean and additive overlapping conditions are introduced and the corresponding inclusion-wise integral equations are formulated. An extended micromechanics method based on these overlapping conditions for linear elastic and viscoelastic heterogeneous material is then developed. An important feature of the proposed approach is that the effect of both the geometric overlapping (clustered particles) and physical overlapping (interacting interphases) on the effective properties can be distinguished. Lastly, we apply the extended micromechanics method to a viscoelastic polymer nanocomposite with interphase regions, and estimate the properties and thickness of the interphase region based on experimental data for carbon-black filled styrene butadiene rubbers.

  6. Study of multiple cracks in airplane fuselage by micromechanics and complex variables

    NASA Technical Reports Server (NTRS)

    Denda, Mitsunori; Dong, Y. F.

    1994-01-01

    Innovative numerical techniques for two dimensional elastic and elastic-plastic multiple crack problems are presented using micromechanics concepts and complex variables. The simplicity and the accuracy of the proposed method will enable us to carry out the multiple-site fatigue crack propagation analyses for airplane fuselage by incorporating such features as the curvilinear crack path, plastic deformation, coalescence of cracks, etc.

  7. Towards the development of micromechanics equations for ceramic matrix composites via fiber substructuring

    NASA Technical Reports Server (NTRS)

    Murthy, P. L. N.; Chamis, C. C.

    1992-01-01

    A generic unit cell model which includes a unique fiber substructuring concept is proposed for the development of micromechanics equations for continuous fiber reinforcement ceramic composites. The unit cell consists of three constituents: fiber, matrix, and an interphase. In the present approach, the unit cell is further subdivided into several slices and the equations of micromechanics are derived for each slice. These are subsequently integrated to obtain ply level properties. A stand alone computer code containing the micromechanics model as a module is currently being developed specifically for the analysis of ceramic matrix composites. Towards this development, equivalent ply property results for a SiC/Ti-15-3 composite with 0.5 fiber volume ratio are presented and compared with those obtained from customary micromechanics models to illustrate the concept. Also, comparisons with limited experimental data for the ceramic matrix composite, SiC/RBSN (Reaction Bonded Silicon Nitride) with a 0.3 fiber volume ratio are given to validate the concepts.

  8. Micromechanical Prediction of the Effective Behavior of Fully Coupled Electro-Magneto-Thermo-Elastic Multiphase Composites

    NASA Technical Reports Server (NTRS)

    Aboudi, Jacob

    2000-01-01

    The micromechanical generalized method of cells model is employed for the prediction of the effective moduli of electro-magneto-thermo-elastic composites. These include the effective elastic, piezoelectric, piezomagnetic, dielectric, magnetic permeability, electromagnetic coupling moduli, as well as the effective thermal expansion coefficients and the associated pyroelectric and pyromagnetic constants. Results are given for fibrous and periodically bilaminated composites.

  9. A micromechanical approach to elastic and viscoelastic properties of fiber reinforced concrete

    SciTech Connect

    Pasa Dutra, V.F.; Maghous, S. Campos Filho, A.; Pacheco, A.R.

    2010-03-15

    Some aspects of the constitutive behavior of fiber reinforced concrete (FRC) are investigated within a micromechanical framework. Special emphasis is put on the prediction of creep of such materials. The linear elastic behavior is first examined by implementation of a Mori-Tanaka homogenization scheme. The micromechanical predictions for the overall stiffness prove to be very close to finite element solutions obtained from the numerical analysis of a representative elementary volume of FRC modeled as a randomly heterogeneous medium. The validation of the micromechanical concepts based on comparison with a set of experiments, shows remarkable predictive capabilities of the micromechanical representation. The second part of the paper is devoted to non-ageing viscoelasticity of FRC. Adopting a Zener model for the behavior of the concrete matrix and making use of the correspondence principle, the homogenized relaxation moduli are derived analytically. The validity of the model is established by mean of comparison with available experiment measurements of creep strain of steel fiber reinforced concrete under compressive load. Finally, the model predictions are compared to those derived from analytical models formulated within a one-dimensional setting.

  10. A micromechanical device that monitors arterial pressure during general anesthesia and in intensive care units

    NASA Astrophysics Data System (ADS)

    Andreeva, A. V.; Luchinin, V. V.; Kuzmina, K. A.; Klyavinek, A. S.; Karelov, A. E.

    2015-12-01

    A vibroacoustic fiber optic system that consists of micromechanical components designated for use in medicine and biology is reviewed. A theoretical analysis of a fiber optic microphone is done and its optimal construction parameters are determined. The possibility of using the developed system with magnetic resonance tomography to noninvasively measure man's arterial pressure is specified.

  11. Micromechanical modelling of partially molten and sand reinforced polycrystalline ice

    NASA Astrophysics Data System (ADS)

    Castelnau, O.; Duval, P.

    2009-12-01

    The viscoplastic behaviour of polycrystalline ice is strongly affected by the very strong anisotropy of ice crystals. Indeed, in the dislocations creep regime relevant for ice sheet flow, dislocation glide on the basal plane of ice single crystals leads to strain-rates ~6 order of magnitude larger than strain-rates that might be obtain if only non-basal glide is activated. At the polycrystal scale, this behaviour is responsible for a strong mechanical interaction between grains in the secondary (stationary) creep regime, and strain-rate is essentially partitioned between soft grains well-oriented for basal glide and hard grains exhibiting an unfavourable orientation for basal slip. As a consequence, the macroscopic flow stress at the polycrystal scale essentially depends on the resistance of the hardest slip systems or on the associated accommodation processes such as climb of basal dislocation on non-basal planes. Creep experiments performed on polycrystalline ices containing a small amount (less than 10% volume fraction) of liquid water show a dramatic increase of strain-rate, by more than one order of magnitude, compared to solid ice when deformed under similar thermo-mechanical conditions. Similarly, a strong hardening is observed when polycrystalline ice is reinforced by sand (which can be considered as a rigid phase here). This behaviour can be explained by micromechanical models, which aims at estimating the mechanical interactions between grains. For example, the presence of water releases stress concentrations at grain boundaries and therefore favours the inactivation of non-basal systems. To estimate such effect and to reach quantitative comparison with experimental data, we make use of the recent Second-Order homogenization mean-field approach of Ponte-Castaneda, based on self-consistent scheme. The advantage of this approach, which has been shown to provide excellent results when applied to many different non-linear composite materials, comes from the

  12. An engineering model of woven composites based on micromechanics

    NASA Technical Reports Server (NTRS)

    Carter, W. C.; Cox, B. N.; Dadkhah, M. S.; Morris, W. L.

    1993-01-01

    Composites with three-dimensional woven architectures exhibit large strains to failure when compared to composites made up of the same materials but not with three-dimensional interlocking tows. The fracture mechanics of such three-dimensional architectures is a subject requiring substantial investigation and experimental testing. Classical fracture mechanics concepts (for instance, an isolated defect in a homogeneous body) will not be applicable to the woven fracture test specimen. The use of an isolated singularity to characterize an entire specimen is inadequate when the density of defects is considerable and the material is heterogeneous. Modelling of such a complex system requires a great deal of insight and consideration as well as prudent choices of model sizes to make numerical schemes feasible. The purpose of this manuscript is to review our recently acquired knowledge of damage accumulation in woven composites and to describe a practicable model of the macroscopic behavior in these and other complex composite architectures based on such knowledge. In this manuscript, discussion will be limited to uniaxial compressive loading; considerations of general loading (monotonic and cyclic) will appear in a subsequent manuscript. Our modelling efforts may be briefly described as follows: the composite is subdivided into microstructural elements (microelements) in which the micromechanical modelling is either understood rigorously or can be represented adequately by statistical parameters. There can be microstructural elements for many different types of composite components, such as the various types of warp and weft and matrix for three-dimensional woven composites. The physical dimensions of microelements are made as large as possible while the response within the element can still be represented by a single micromechatlical calculation. The various elements are linked together(sometimes by associating distinct corners and edges, sometimes by superposition) in a

  13. Micromechanical characterization of the interphase zone in adhesive joints

    NASA Astrophysics Data System (ADS)

    Safavi-Ardebili, Vahid

    The interphase in an epoxy-aluminum adhesive system has been characterized using acoustic microscopy, scanning electron microscopy, ion etching, energy-dispersive x-ray analysis, and nano-indentation, with particular attention to micromechanical characterization. A systematic search method was proposed for locating an acoustic coupling fluid which had a sufficiently low velocity of sound and attenuation factor for the acoustic microscopy of polymers. A new acoustic microscope system was developed, which operated at a frequency of 250 MHz, and utilized an ultrasonic probe designed specifically for the characteristics of the new couplant. This acoustic microscope system is the first one being able to induce Rayleigh waves on the surface of plastics. A new angular spectrum formulation was introduced for a type-II acoustic microscope probe. No prior assumption, regarding the field on the aperture plane of the transducer, is needed in this new formulation. The angular spectrum model was extended to the case of a type-I probe in the presence of deviations of the lens shape from the ideal sphere as long as it remains axisymmetric. A multiple curve fitting procedure was used to infer the interphase property profiles by simultaneously fitting a large number of calculated V (z) curves to the experimental ones. The interphase was between 2 and 6 mum thick, and corresponded to a region of greater resistance to ion etching and a marked absence of the silica particles used in the epoxy adhesive. The acoustic microscope V(z) scans showed that the interphase had, on average, 20% larger values of tensile and shear moduli than the bulk, and smaller values of the shear attenuation factor and density than the bulk adhesive. Nano-indentation tests, traversing various sections of the interphase from the aluminum to the bulk adhesive, showed that the interphase region had, on average, a reduced elastic modulus (E/(1 - nu2)) that was 13% greater than that of the bulk adhesive. The

  14. Intrinsic Energy Dissipation Limits in Nano and Micromechanical Resonators

    NASA Astrophysics Data System (ADS)

    Iyer, Srikanth Subramanian

    Resonant microelectromechanical Systems (MEMS) have enabled miniaturization of high-performance inertial sensors, radio-frequency filters, timing references and mass-based chemical sensors. Despite the increasing prevalence of MEMS resonators for these applications, the energy dissipation in these structures is not well-understood. Accurate prediction of the energy loss and the resulting quality factor (Q) has significant design implications because it is directly related to device performance metrics including sensitivity for resonant sensors, bandwidth for radio-frequency filters and phase-noise for timing references. In order to assess the future potential for MEMS resonators it is critically important to evaluate the energy dissipation limits, which will dictate the ultimate performance resonant MEMS devices can achieve. This work focuses on the derivation and evaluation of the intrinsic mechanical energy dissipation limit for single-crystal nano and micromechanical resonators due to anharmonic phonon-phonon scattering in the Akhiezer regime. The energy loss is derived using perturbation theory and the linearized Boltzmann transport equation for phonons, and includes the direction and polarization dependent mode-Gruneisen parameters in order to capture the strain-induced anharmonicity among phonon branches. Evaluation of the quality factor limit reveals that Akhiezer damping, previously thought to depend only on material properties, has a strong dependence on crystal orientation and resonant mode shape. The robust model provides a dissipation limit for all resonant modes including shear-mode vibrations, which have significantly reduced energy loss because dissipative phonon-phonon scattering is restricted to volume-preserving phonon branches, indicating that Lame or wine-glass mode resonators will have the highest upper limit on mechanical efficiency. Finally, the analytical dissipation model is integrated with commercial finite element software in order to

  15. Viscous anisotropy of textured olivine aggregates: 2. Micromechanical model

    NASA Astrophysics Data System (ADS)

    Hansen, Lars N.; Conrad, Clinton P.; Boneh, Yuval; Skemer, Philip; Warren, Jessica M.; Kohlstedt, David L.

    2016-10-01

    The significant viscous anisotropy that results from crystallographic alignment (texture) of olivine grains in deformed upper mantle rocks strongly influences a large variety of geodynamic processes. Our ability to explore the effects of anisotropic viscosity in simulations of these processes requires a mechanical model that can predict the magnitude of anisotropy and its evolution. Unfortunately, existing models of olivine textural evolution and viscous anisotropy are calibrated for relatively small deformations and simple strain paths, making them less general than desired for many large-scale geodynamic scenarios. Here we develop a new set of micromechanical models to describe the mechanical behavior and textural evolution of olivine through a large range of strains and complex strain histories. For the mechanical behavior, we explore two extreme scenarios, one in which each grain experiences the same stress tensor (Sachs model) and one in which each grain undergoes a strain rate as close as possible to the macroscopic strain rate (pseudo-Taylor model). For the textural evolution, we develop a new model in which the director method is used to control the rate of grain rotation and the available slip systems in olivine are used to control the axis of rotation. Only recently has enough laboratory data on the deformation of olivine become available to calibrate these models. We use these new data to conduct inversions for the best parameters to characterize both the mechanical and textural evolution models. These inversions demonstrate that the calibrated pseudo-Taylor model best reproduces the mechanical observations. Additionally, the pseudo-Taylor textural evolution model can reasonably reproduce the observed texture strength, shape, and orientation after large and complex deformations. A quantitative comparison between our calibrated models and previously published models reveals that our new models excel in predicting the magnitude of viscous anisotropy and

  16. Expanding the Territory of Historical Reconstruction: The Study of Frequency and Severity of Hail Storms, Based on 19th and 20th-Century Records from Swiss Insurance Archives

    NASA Astrophysics Data System (ADS)

    Mauelshagen, F.

    2009-09-01

    than observations from the existing network of meteorological offices. Some researchers have even suggested that the entire period before radar observation, beginning in the 1980s, should be classified as pre-instrumental. However, it is undoubted that documents kept in the archives of insurance companies provide valuable proxy information on hail storm occurrence for, at least, the pre-1950-period (well back into the 19th century). This paper discusses key problems in dealing with these proxy data (reliability, interpretation and density of records), as well as methodologies that may lead to extend existing time series on hail storm occurrence in Switzerland. As a consequence, this paper suggests that, for some meteorological phenomena, the field of reconstruction from documentary archival sources must be extended well up into the 20th century, which cannot simply and statically be categorized as "instrumental period”.

  17. Western Europe's America Problem

    ERIC Educational Resources Information Center

    Markovits, Andrei S.

    2007-01-01

    In this article, the author discusses Europe's anti-Americanism stance. He observes that Europe's aversion to America has become greater, louder, and more determined, and that it has unified Western Europeans more than any other political emotion (with the exception of a common hostility toward Israel). The author contends that the many disastrous…

  18. Applied Linguistics in Europe

    ERIC Educational Resources Information Center

    de Bot, Kees

    2004-01-01

    In this contribution developments in Applied Linguistics in Europe are linked to major social changes that have taken place over the last decades. These include: The decline of the USSR and the end of the cold war; The development of the EEC and the EU and fading of borders; The economic growth of Western Europe; Labor migration from the south to…

  19. Immigrant Languages in Europe.

    ERIC Educational Resources Information Center

    Extra, Guus, Ed.; Verhoeven, Ludo, Ed.

    Papers from a 1990 Dutch colloquium on immigrant language varieties in Europe are presented in four categories: (1) use of immigrant language varieties in Europe; (2) first language acquisition in a second language context; (3) code-switching; and (4) language maintenance and loss. Papers include: "Sweden Finnish" (Jarmo Lainio);…

  20. Astronomy Teaching in Argentina in the 19th Century. (Spanish Title: La Enseñanza de la Astronomía en la Argentina del Siglo XIX.) O Ensino de Astronomia na Argentina no Século XIX

    NASA Astrophysics Data System (ADS)

    Norberto Cornejo, Jorge; Santilli, Haydée

    2010-12-01

    Sarmiento believed that Copernican astronomy was one of the critical scientific disciplines to the formation of a "modern" citizen. In this work, we shall study astronomical science from two points of view: from the scientific knowledge and the educational presentation of such knowledge. Our study will address in Argentina in 19th century, starting from the initiative of Bernardino Rivadavia in 1821, who founded an astronomic observatory at Buenos Aires, until the first activities of the observatories at Córdoba and La Plata. On both lines, scientific and educative, we shall analyze the influence of positivist ideas. We shall highlight epistemological differences between both observatories, Córdoba's based on French positivism and La Plata's based on German positivism. We shall also show the different attitude of both observatories towards education. We shall see the way in which positivist ideas had great relevance in the training of elementary school teachers. We shall also establish the relevant influence of the socio-historical context over the astronomical development, and show that astronomy was a fundamental social factor at Argentina history. Domingo F. Sarmiento consideraba que la astronomía copernicana era una de las disciplinas científicas fundamentales para la conformación de un ciudadano "moderno". En este trabajo estudiaremos la ciencia astronómica desde dos vertientes: la referida específicamente al conocimiento científico y aquella vinculada con la presentación educativa de dicho conocimiento. Nuestro estudio se desarrollará en Argentina durante el siglo XIX, desde la iniciativa de Bernardino Rivadavia en 1821, de establecer en Buenos Aires un observatorio astronómico, hasta las primeras actividades de los observatorios de Córdoba y de La Plata. En ambas vertientes, científica y educativa, analizaremos la influencia de las ideas positivistas. Resaltaremos las diferencias epistemológicas entre los dos observatorios, orientado el primero

  1. A micromechanical damage and fracture model for polymers based on fractional strain-gradient elasticity

    NASA Astrophysics Data System (ADS)

    Heyden, S.; Li, B.; Weinberg, K.; Conti, S.; Ortiz, M.

    2015-01-01

    We formulate a simple one-parameter macroscopic model of distributed damage and fracture of polymers that is amenable to a straightforward and efficient numerical implementation. We show that the macroscopic model can be rigorously derived, in the sense of optimal scaling, from a micromechanical model of chain elasticity and failure regularized by means of fractional strain-gradient elasticity. In particular, we derive optimal scaling laws that supply a link between the single parameter of the macroscopic model, namely, the critical energy-release rate of the material, and micromechanical parameters pertaining to the elasticity and strength of the polymer chains and to the strain-gradient elasticity regularization. We show how the critical energy-release rate of specific materials can be determined from test data. Finally, we demonstrate the scope and fidelity of the model by means of an example of application, namely, Taylor-impact experiments of polyurea 1000 rods.

  2. Method for identifying biochemical and chemical reactions and micromechanical processes using nanomechanical and electronic signal identification

    DOEpatents

    Holzrichter, J.F.; Siekhaus, W.J.

    1997-04-15

    A scanning probe microscope, such as an atomic force microscope (AFM) or a scanning tunneling microscope (STM), is operated in a stationary mode on a site where an activity of interest occurs to measure and identify characteristic time-varying micromotions caused by biological, chemical, mechanical, electrical, optical, or physical processes. The tip and cantilever assembly of an AFM is used as a micromechanical detector of characteristic micromotions transmitted either directly by a site of interest or indirectly through the surrounding medium. Alternatively, the exponential dependence of the tunneling current on the size of the gap in the STM is used to detect micromechanical movement. The stationary mode of operation can be used to observe dynamic biological processes in real time and in a natural environment, such as polymerase processing of DNA for determining the sequence of a DNA molecule. 6 figs.

  3. Critique of Macro Flow/Damage Surface Representations for Metal Matrix Composites Using Micromechanics

    NASA Technical Reports Server (NTRS)

    Lissenden, Cliff J.; Arnold, Steven M.

    1996-01-01

    Guidance for the formulation of robust, multiaxial, constitutive models for advanced materials is provided by addressing theoretical and experimental issues using micromechanics. The multiaxial response of metal matrix composites, depicted in terms of macro flow/damage surfaces, is predicted at room and elevated temperatures using an analytical micromechanical model that includes viscoplastic matrix response as well as fiber-matrix debonding. Macro flow/damage surfaces (i.e., debonding envelopes, matrix threshold surfaces, macro 'yield' surfaces, surfaces of constant inelastic strain rate, and surfaces of constant dissipation rate) are determined for silicon carbide/titanium in three stress spaces. Residual stresses are shown to offset the centers of the flow/damage surfaces from the origin and their shape is significantly altered by debonding. The results indicate which type of flow/damage surfaces should be characterized and what loadings applied to provide the most meaningful experimental data for guiding theoretical model development and verification.

  4. Micromechanics-Based Progressive Failure Analysis of Composite Laminates Using Different Constituent Failure Theories

    NASA Technical Reports Server (NTRS)

    Moncada, Albert M.; Chattopadhyay, Aditi; Bednarcyk, Brett A.; Arnold, Steven M.

    2008-01-01

    Predicting failure in a composite can be done with ply level mechanisms and/or micro level mechanisms. This paper uses the Generalized Method of Cells and High-Fidelity Generalized Method of Cells micromechanics theories, coupled with classical lamination theory, as implemented within NASA's Micromechanics Analysis Code with Generalized Method of Cells. The code is able to implement different failure theories on the level of both the fiber and the matrix constituents within a laminate. A comparison is made among maximum stress, maximum strain, Tsai-Hill, and Tsai-Wu failure theories. To verify the failure theories the Worldwide Failure Exercise (WWFE) experiments have been used. The WWFE is a comprehensive study that covers a wide range of polymer matrix composite laminates. The numerical results indicate good correlation with the experimental results for most of the composite layups, but also point to the need for more accurate resin damage progression models.

  5. Analysis of metal-matrix composite structures. I - Micromechanics constitutive theory. II - Laminate analyses

    NASA Technical Reports Server (NTRS)

    Arenburg, R. T.; Reddy, J. N.

    1991-01-01

    The micromechanical constitutive theory is used to examine the nonlinear behavior of continuous-fiber-reinforced metal-matrix composite structures. Effective lamina constitutive relations based on the Abouli micromechanics theory are presented. The inelastic matrix behavior is modeled by the unified viscoplasticity theory of Bodner and Partom. The laminate constitutive relations are incorporated into a first-order deformation plate theory. The resulting boundary value problem is solved by utilizing the finite element method. Attention is also given to computational aspects of the numerical solution, including the temporal integration of the inelastic strains and the spatial integration of bending moments. Numerical results the nonlinear response of metal matrix composites subjected to extensional and bending loads are presented.

  6. Experimental investigation of micromechanical behavior of advanced materials by moiré interferometry

    NASA Astrophysics Data System (ADS)

    Qing, Xinlin; Qin, Yuwen; Dai, Fulong

    1996-09-01

    Several typical instances show that moiré interferometry is an effective experimental method for micromechanics study of advanced materials. By using moiré interferometry, stress-induced martensitic transformation plastic zone in ceria-stabilized tetragonal zirconia polycrystalline ceramics (Ce-TZP) is studied. The experimental results show that the stress-induced transformation at room temperature is not uniform within the transformation zone and the phenomenon of microscopic plastic flow localization for transformation is revealed. Meanwhile, the experimental investigation of the pseudoelasticity behavior of Cu-Zn-Al polycrystalline shape memory alloy and bending behavior of carbon-fiber aluminium laminates (CALL) are reported. The experiments reveal some important features of the deformation processes of the materials. Finally, the measuring ability of moiré interferometry for micromechanics study is discussed.

  7. Micromechanical and Electrical Properties of Monolithic Aluminum Nitride at High Temperatures

    NASA Technical Reports Server (NTRS)

    Goldsby, Jon C.

    2000-01-01

    Micromechanical spectroscopy of aluminum nitride reveals it to possess extremely low background internal friction at less than 1x10(exp-4) logarithmic decrement (log dec) from 20 to 1200 T. Two mechanical loss peaks were observed, the first at 350 C approximating a single Debye peak with a peak height of 60x10(exp-4) log dec. The second peak was seen at 950 'C with a peak height of 20x 10' log dec and extended from 200 to over 1200 C. These micromechanical observations manifested themselves in the electrical behavior of these materials. Electrical conduction processes were predominately intrinsic. Both mechanical and electrical relaxations appear to be thermally activated processes, with activation energies of 0.78 and 1.32 eV respectively.

  8. Micromechanical and Electrical Properties of Monolithic Aluminum Nitride at High Temperatures

    NASA Technical Reports Server (NTRS)

    Goldsby, Jon C.

    2001-01-01

    Micromechanical spectroscopy of aluminum nitride reveals it to possess extremely low background internal friction at less than 1 x 10 (exp -4) logarithmic decrement (log dec.) from 20 to 1200 C. Two mechanical loss peaks were observed, the first at 350 C approximating a single Debye peak with a peak height of 60 x 10 (exp -4) log dec. The second peak was seen at 950 C with a peak height of 20 x 10 (exp -4) log dec. and extended from 200 to over 1200 C. These micromechanical observations manifested themselves in the electrical behavior of these materials. Electrical conduction processes were predominately intrinsic. Both mechanical and electrical relaxations appear to be thermally activated processes, with activation energies of 0.78 and 1.32 eV respectively.

  9. Micromechanical Modeling of R-Curve Behaviors in Human Cortical Bone

    PubMed Central

    Chan, Kwai S.; Nicolella, Daniel P.

    2012-01-01

    The risk of bone fracture increases with age because of a variety of factors that include, among others, decreasing bone quantity and quality due to increasing porosity and crack density with age. Experimental evidence has indicated that changes in bone microstructure and trace mineralization with age can result in different crack-tip strain field and fracture response, leading to different fracture mechanisms and R-curve behaviors. In this paper, a micromechanical modeling approach is developed to predict the R-curve response of bone tissue by delineating fracture mechanisms that lead to microdamage and ligament bridging by incorporating the influence of increasing porosity and crack density with age. The effects of age on fracture of human femur cortical bone due to porosity (bone quantity) and bone quality (crack density) with age are then examined via the micromechanical model. PMID:23158217

  10. Method for identifying biochemical and chemical reactions and micromechanical processes using nanomechanical and electronic signal identification

    DOEpatents

    Holzrichter, John F.; Siekhaus, Wigbert J.

    1997-01-01

    A scanning probe microscope, such as an atomic force microscope (AFM) or a scanning tunneling microscope (STM), is operated in a stationary mode on a site where an activity of interest occurs to measure and identify characteristic time-varying micromotions caused by biological, chemical, mechanical, electrical, optical, or physical processes. The tip and cantilever assembly of an AFM is used as a micromechanical detector of characteristic micromotions transmitted either directly by a site of interest or indirectly through the surrounding medium. Alternatively, the exponential dependence of the tunneling current on the size of the gap in the STM is used to detect micromechanical movement. The stationary mode of operation can be used to observe dynamic biological processes in real time and in a natural environment, such as polymerase processing of DNA for determining the sequence of a DNA molecule.

  11. Micromechanical modeling of R-curve behaviors in human cortical bone.

    PubMed

    Chan, Kwai S; Nicolella, Daniel P

    2012-12-01

    The risk of bone fracture increases with age because of a variety of factors that include, among others, decreasing bone quantity and quality due to increasing porosity and crack density with age. Experimental evidence has indicated that changes in bone microstructure and trace mineralization with age can result in different crack-tip strain field and fracture response, leading to different fracture mechanisms and R-curve behaviors. In this paper, a micromechanical modeling approach is developed to predict the R-curve response of bone tissue by delineating fracture mechanisms that lead to microdamage and ligament bridging by incorporating the influence of increasing porosity and crack density with age. The effects of age on fracture of human femur cortical bone due to porosity (bone quantity) and bone quality (crack density) with age are then examined via the micromechanical model.

  12. Reducing support loss in micromechanical ring resonators using phononic band-gap structures

    NASA Astrophysics Data System (ADS)

    Hsu, Feng-Chia; Hsu, Jin-Chen; Huang, Tsun-Che; Wang, Chin-Hung; Chang, Pin

    2011-09-01

    In micromechanical resonators, energy loss via supports into the substrates may lead to a low quality factor. To eliminate the support loss, in this paper a phononic band-gap structure is employed. We demonstrate a design of phononic-crystal (PC) strips used to support extensional wine-glass mode ring resonators to increase the quality factor. The PC strips are introduced to stop elastic-wave propagation by the band-gap and deaf-band effects. Analyses of resonant characteristics of the ring resonators and the dispersion relations, eigenmodes, and transmission properties of the PC strips are presented. With the proposed resonator architecture, the finite-element simulations show that the leaky power is effectively reduced and the stored energy inside the resonators is enhanced simultaneously as the operating frequencies of the resonators are within the band gap or deaf bands. Realization of a high quality factor micromechanical ring resonator with minimized support loss is expected.

  13. EPA Collaboration with Europe

    EPA Pesticide Factsheets

    By working together to achieve common goals, the U.S. and Europe can enhance our respective environmental protection efforts while creating a cleaner environment on both continents and around the world.

  14. Micromechanical modeling of laminated composites with interfaces and woven composites using the boundary element method

    NASA Technical Reports Server (NTRS)

    Goldberg, Robert K.; Hopkins, Dale A.

    1993-01-01

    The boundary element method is utilized to analyze the effects of fiber/matrix interfaces on the micromechanical behavior of laminated composites as well as the elastic behavior of woven composites. Effective composite properties are computed for laminated SiC/RBSN and SiC/Ti-15-3 composites, as well as a woven SiC/SiC composite. The properties calculated using the computerized tool BEST-CMS match the experimental results well.

  15. Fatigue Micromechanism Characterization in Carbon Fibre Reinforced Polymers Using Synchrotron Radiation Computed Tomography

    DTIC Science & Technology

    2014-12-18

    Statement A: Approved for public release distribution is unlimited. REPORT DOCUMENTATION PAGE Form Approved OMB No. 0704-0188 Public reporting burden...with a collection of information if it does not display a currently valid OMB control number. PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS. 1...NUMBER (Include area code) +44 (0)1895 616420 Standard Form 298 (Rev. 8/98) Prescribed by ANSI Std. Z39-18 Fatigue micromechanism

  16. Micromechanics Analysis Code With Generalized Method of Cells (MAC/GMC): User Guide. Version 3

    NASA Technical Reports Server (NTRS)

    Arnold, S. M.; Bednarcyk, B. A.; Wilt, T. E.; Trowbridge, D.

    1999-01-01

    The ability to accurately predict the thermomechanical deformation response of advanced composite materials continues to play an important role in the development of these strategic materials. Analytical models that predict the effective behavior of composites are used not only by engineers performing structural analysis of large-scale composite components but also by material scientists in developing new material systems. For an analytical model to fulfill these two distinct functions it must be based on a micromechanics approach which utilizes physically based deformation and life constitutive models and allows one to generate the average (macro) response of a composite material given the properties of the individual constituents and their geometric arrangement. Here the user guide for the recently developed, computationally efficient and comprehensive micromechanics analysis code, MAC, who's predictive capability rests entirely upon the fully analytical generalized method of cells, GMC, micromechanics model is described. MAC/ GMC is a versatile form of research software that "drives" the double or triply periodic micromechanics constitutive models based upon GMC. MAC/GMC enhances the basic capabilities of GMC by providing a modular framework wherein 1) various thermal, mechanical (stress or strain control) and thermomechanical load histories can be imposed, 2) different integration algorithms may be selected, 3) a variety of material constitutive models (both deformation and life) may be utilized and/or implemented, and 4) a variety of fiber architectures (both unidirectional, laminate and woven) may be easily accessed through their corresponding representative volume elements contained within the supplied library of RVEs or input directly by the user, and 5) graphical post processing of the macro and/or micro field quantities is made available.

  17. Micromechanics of metal matrix composites using the Generalized Method of Cells model (GMC) user's guide

    NASA Technical Reports Server (NTRS)

    Aboudi, Jacob; Pindera, Marek-Jerzy

    1992-01-01

    A user's guide for the program gmc.f is presented. The program is based on the generalized method of cells model (GMC) which is capable via a micromechanical analysis, of predicting the overall, inelastic behavior of unidirectional, multi-phase composites from the knowledge of the properties of the viscoplastic constituents. In particular, the program is sufficiently general to predict the response of unidirectional composites having variable fiber shapes and arrays.

  18. Intrinsic Micromechanism of Multi-step Structural Transformation in MnNi Shape Memory Alloys

    NASA Astrophysics Data System (ADS)

    Cui, Shushan; Wan, Jianfeng; Rong, Yonghua; Zhang, Jihua

    2017-03-01

    Simulation of the multi-step transformation of cubic matrix → multi-variant tetragonal domain → orthorhombic domain was realized by phase-field method. The intrinsic micromechanism of the second-step transformation in MnNi alloys was studied. It was found that the orthorhombic variant originated from the tetragonal variant with similar orientation, and bar-shaped orthorhombic phase firstly occurred around the interface of twinning bands. The second-step transformation resulted in localized variation of internal stress.

  19. Activation barrier scaling and crossover for noise-induced switching in micromechanical parametric oscillators.

    PubMed

    Chan, H B; Stambaugh, C

    2007-08-10

    We explore fluctuation-induced switching in parametrically driven micromechanical torsional oscillators. The oscillators possess one, two, or three stable attractors depending on the modulation frequency. Noise induces transitions between the coexisting attractors. Near the bifurcation points, the activation barriers are found to have a power law dependence on frequency detuning with critical exponents that are in agreement with predicted universal scaling relationships. At large detuning, we observe a crossover to a different power law dependence with an exponent that is device specific.

  20. Laminate Analyses, Micromechanical Creep Response, and Fatigue Behavior of Polymer Matrix Composite Materials.

    DTIC Science & Technology

    1982-12-01

    FATIGUE BEHAVIOR of POLYMER MATRIX COMPOSITE MATERIALS , 4 " .’* .. . . ". ... .. ... . . ~December 1982 41 .. FINAL REPORT .Army Research Office I I...DEPARTMENT REPORT UWME-DR-201-108-1 LAMINATE ANALYSES, MICROMECHANICAL CREEP RESPONSE, AND FATIGUE BEHAVIOR OF POLYMER MATRIX COMPOSITE MATERIALS...Behavior of Polymer Matrix Composite 16 Sept. 1979 - 30 Nov. 1982 Materials 6 PERFORMING ORG. REPORT NUMBER UWME-DR-201-108-1 7. AUTHOR(.) S. CONTRACT

  1. Pattern recognition characterizations of micromechanical and morphological materials states via analytical quantitative ultrasonics

    NASA Technical Reports Server (NTRS)

    Williams, J. H., Jr.; Lee, S. S.

    1986-01-01

    One potential approach to the quantitative acquisition of discriminatory information that can isolate a single structural state is pattern recognition. The pattern recognition characterizations of micromechanical and morphological materials states via analytical quantiative ultrasonics are outlined. The concepts, terminology, and techniques of statistical pattern recognition are reviewed. Feature extraction and classification and states of the structure can be determined via a program of ultrasonic data generation.

  2. Supercritical carbon dioxide solvent extraction from surface-micromachined micromechanical structures

    SciTech Connect

    Dyck, C.W.; Smith, J.H.; Miller, S.L.; Russick, E.M.; Adkins, C.L.J.

    1996-10-01

    Results are presented supporting the use of supercritical carbon dioxide (SCCO{sub 2}) drying to enhance the yield of surface-micromachined micromechanical devices following the final release etch. The equipment and extraction process of the SCCO{sub 2} system are described, and results of successfully released cantilevered beams and microengines are presented. A new system capable of drying 6 inch wafers is also described.

  3. In-Situ Micromechanical Testing in Extreme Environments

    NASA Astrophysics Data System (ADS)

    Lupinacci, Amanda Sofia

    In order to design engineering applications that can withstand extreme environments, we must first understand the underlying deformation mechanisms that can hinder material performance. It is not enough to characterize the mechanical properties alone, we must also characterize the microstructural changes as well so that we can understand the origin of material degradation. This dissertation focuses on two different extreme environments. The first environment is the cryogenic environment, where we focus on the deformation behavior of solder below the ductile to brittle transition temperature (DBTT). The second environment is the irradiated environment, where we focus on the effects that ion beam irradiation has on both the mechanical properties and microstructure of 304 stainless steel. Both classes of materials and testing environments utilize novel in situ micromechanical testing techniques inside a scanning electron microscope which enhances our ability to link the observed deformation behavior with its associated mechanical response. Characterizing plasticity mechanisms below the DBTT is traditionally difficult to accomplish in a systematic fashion. Here, we use a new experimental setup to perform in situ cryogenic mechanical testing of pure Sn micropillars at room temperature and at -142 °C. Subsequent electron microscopy characterization of the micropillars shows a clear difference in the deformation mechanisms at room temperature and at cryogenic temperatures. At room temperature, the Sn micropillars deformed through dislocation plasticity while at -142 °C they exhibited both higher strength and deformation twinning. Two different orientations were tested, a symmetric (100) orientation and a non-symmetric (45¯1) orientation. The deformation mechanisms were found to be the same for both orientations. This approach was also extended to a more complex solder alloy that is commonly used in industry, Sn96. In the case of the solder alloy more complex geometries

  4. JPRS Report, East Europe.

    DTIC Science & Technology

    1990-07-17

    Ministry of equipped to deal with this. To provide services for the Finances, assures us. A similar rule will apply to pen- hundreds of thousands of...JPRS-EER-90-105 17 JULY 1990 FOREIGN BROADCAST INFORMATION SERVICE -’PRS Report-- East Europe REPRODUCED BY U.S. DEPARTMENT OF COMMERCE NATIONAL...TECHNICAL INFORMATION SERVICE SPRINGFIELD, VA. 22161 , VmR...U..ON 3TA.... A East Europe JPRS-EER-90-105 CONTENTS 17 July 1990 POLITICAL INTRABLOC PNUC

  5. Overall challenges in incorporating micro-mechanical models into materials design process

    NASA Astrophysics Data System (ADS)

    Bennoura, M.; Aboutajeddine, A.

    2016-10-01

    Using materials in engineering design has historically been handled using the paradigm of selecting appropriate materials from the finite set of available material databases. Recent trends, however, have moved toward the tailoring of materials that meet the overall system performance requirements, based on a process called material design. An important building block of this process is micromechanical models that relate microstructure to proprieties. Unfortunately, these models remain short and include a lot of uncertainties from assumptions and idealizations, which, unavoidably, impacts material design strategy. In this work, candidate methods to deal with micromechanical models uncertainties and their drawbacks in material design are investigated. Robust design methods for quantifying uncertainty and managing or mitigating its impact on design performances are reviewed first. These methods include principles for classifying uncertainty, mathematical techniques for evaluating its level degree, and design methods for performing and generating design alternatives, that are relatively insensitive to sources of uncertainty and flexible for admitting design changes or variations. The last section of this paper addresses the limits of the existing approaches from material modelling perspective and identifies the research opportunities to overcome the impediment of incorporating micromechanical models in material design process.

  6. Stress-Transfer Micromechanics For Fiber Length with a Photocure Vinyl Ester Composite

    PubMed Central

    Petersen, Richard C.; Lemons, Jack E.; McCracken, Michael S.

    2014-01-01

    The objective was to test how increasing fiber length above the critical length would influence mechanical properties and fracture crack propagation. Micromechanics considering fiber/matrix stress-transfer was used to evaluate the results in addition to a shear debonding volume percent correction term necessary for the final analysis. Fiber lengths of 0.5, 1.0, 2.0, 3.0, and 6.0 mm with 9 μm diameters were added into a photocure vinyl ester particulate-filled composite at a uniform 28.2 vol%. Mechanical flexural testing was performed using four-point fully articulated fixtures for samples measuring 2 × 2 × 50 mm3 across a 40 mm span. Fiber length correlated with improved mechanical properties for flexural strength, modulus, yield strength, strain, work of fracture, and strain energy release, p < 0.001. In addition, sample fracture depth significantly decreased with increasing fiber lengths, p < 0.00001. All mechanical properties correlated significantly as predictors for fracture failure, p < 0.000001, and as estimators for each other, p < 0.0001. The stress-transfer micromechanics for fiber length were improved upon for strength by including a simple correction factor to account for loss of fiber volume percent related to cracks deflecting around debonded fiber ends. In turn, the elastic property of modulus was shown to exhibit a tendency to follow stress-transfer micromechanics. PMID:25382894

  7. Micromechanics-Based Structural Analysis (FEAMAC) and Multiscale Visualization within Abaqus/CAE Environment

    NASA Technical Reports Server (NTRS)

    Arnold, Steven M.; Bednarcyk, Brett A.; Hussain, Aquila; Katiyar, Vivek

    2010-01-01

    A unified framework is presented that enables coupled multiscale analysis of composite structures and associated graphical pre- and postprocessing within the Abaqus/CAE environment. The recently developed, free, Finite Element Analysis--Micromechanics Analysis Code (FEAMAC) software couples NASA's Micromechanics Analysis Code with Generalized Method of Cells (MAC/GMC) with Abaqus/Standard and Abaqus/Explicit to perform micromechanics based FEA such that the nonlinear composite material response at each integration point is modeled at each increment by MAC/GMC. The Graphical User Interfaces (FEAMAC-Pre and FEAMAC-Post), developed through collaboration between SIMULIA Erie and the NASA Glenn Research Center, enable users to employ a new FEAMAC module within Abaqus/CAE that provides access to the composite microscale. FEA IAC-Pre is used to define and store constituent material properties, set-up and store composite repeating unit cells, and assign composite materials as sections with all data being stored within the CAE database. Likewise FEAMAC-Post enables multiscale field quantity visualization (contour plots, X-Y plots), with point and click access to the microscale i.e., fiber and matrix fields).

  8. A micromechanical constitutive model for the dynamic response of brittle materials "Dynamic response of marble"

    NASA Astrophysics Data System (ADS)

    Haberman, Keith

    2001-07-01

    A micromechanically based constitutive model for the dynamic inelastic behavior of brittle materials, specifically "Dionysus-Pentelicon marble" with distributed microcracking is presented. Dionysus-Pentelicon marble was used in the construction of the Parthenon, in Athens, Greece. The constitutive model is a key component in the ability to simulate this historic explosion and the preceding bombardment form cannon fire that occurred at the Parthenon in 1678. Experiments were performed by Rosakis (1999) that characterized the static and dynamic response of this unique material. A micromechanical constitutive model that was previously successfully used to model the dynamic response of granular brittle materials is presented. The constitutive model was fitted to the experimental data for marble and reproduced the experimentally observed basic uniaxial dynamic behavior quite well. This micromechanical constitutive model was then implemented into the three dimensional nonlinear lagrangain finite element code Dyna3d(1998). Implementing this methodology into the three dimensional nonlinear dynamic finite element code allowed the model to be exercised on several preliminary impact experiments. During future simulations, the model is to be used in conjunction with other numerical techniques to simulate projectile impact and blast loading on the Dionysus-Pentelicon marble and on the structure of the Parthenon.

  9. A micromechanics-based strength prediction methodology for notched metal matrix composites

    NASA Technical Reports Server (NTRS)

    Bigelow, C. A.

    1992-01-01

    An analytical micromechanics based strength prediction methodology was developed to predict failure of notched metal matrix composites. The stress-strain behavior and notched strength of two metal matrix composites, boron/aluminum (B/Al) and silicon-carbide/titanium (SCS-6/Ti-15-3), were predicted. The prediction methodology combines analytical techniques ranging from a three dimensional finite element analysis of a notched specimen to a micromechanical model of a single fiber. In the B/Al laminates, a fiber failure criteria based on the axial and shear stress in the fiber accurately predicted laminate failure for a variety of layups and notch-length to specimen-width ratios with both circular holes and sharp notches when matrix plasticity was included in the analysis. For the SCS-6/Ti-15-3 laminates, a fiber failure based on the axial stress in the fiber correlated well with experimental results for static and post fatigue residual strengths when fiber matrix debonding and matrix cracking were included in the analysis. The micromechanics based strength prediction methodology offers a direct approach to strength prediction by modeling behavior and damage on a constituent level, thus, explicitly including matrix nonlinearity, fiber matrix debonding, and matrix cracking.

  10. A micromechanical study of drying and carbonation effects in cement-based materials

    NASA Astrophysics Data System (ADS)

    Shen, W. Q.; Shao, J. F.; Kondo, D.

    2015-01-01

    This paper is devoted to a micromechanical study of mechanical properties of cement-based materials by taking into account effects of water saturation degree and carbonation process. To this end, the cement-based materials are considered as a composite material constituted with a cement matrix and aggregates (inclusions). Further, the cement matrix is seen as a porous medium with a solid phase (CSH) and pores. Using a two-step homogenization procedure, a closed-form micromechanical model is first formulated to describe the basic mechanical behavior of materials. This model is then extended to partially saturated materials in order to account for the effects of water saturation degree on the mechanical properties. Finally, considering the solid phase change and porosity variation related to the carbonation process, the micromechanical model is coupled with the chemical reaction and is able to describe the consequences of carbonation on the macroscopic mechanical properties of material. Some comparisons between numerical results and experimental data are presented.

  11. Micromechanics for Fiber Volume Percent With a Photocure Vinyl Ester Composite

    PubMed Central

    Petersen, Richard C.; Lemons, Jack E.; McCracken, Michael S.

    2014-01-01

    Micromechanics for fiber volume percent (Vf) from 0.0Vf to 54.0 Vf were conducted using (3 mm long × 9 µm diameter) high-purity quartz fibers in a visible-light vinyl ester particulate-filled photocure resin. MTS fully articulated four-point bend fixtures were used with a 40 mm test span and 50 × 2 × 2 mm3 sample dimensions. Specimens were tested following the combined modified ASTM standards for advanced ceramics ASTM-C-1161–94 and polymers ASTM-D-6272–00 for modulus, flexural strength, and yield strength. Experimental data provided reliable statistical support for the dominant fiber contribution expressed through the rule-of-mixtures theory as a valid representation of micromechanical physics. The rule-of-mixtures micromechanics described by Vf could explain 92, 85, and 78% of the variability related to modulus, flexural strength, and yield strength respectively. Statistically significant improvements with fiber addition began at 10.3Vf for modulus, 5.4Vf for flexural strength, and 10.3Vf for yield strength, p < 0.05. In addition, correlation matrix analysis was performed for all mechanical test data. An increase in Vf correlated significantly with increases in modulus, flexural strength, and yield strength as measured by the four-point bending test, p < 10−10. All mechanical properties in turn correlated highly significantly with one another, p < 10−9. PMID:25382895

  12. Mechanical Characterization and Micromechanical Modeling of Woven Carbon/Copper Composites

    NASA Technical Reports Server (NTRS)

    Bednarcyk, Brett A.; Pindera, Marek-Jerzy; Ellis, David L.; Miner, Robert V.

    1997-01-01

    The present investigation examines the in-plane mechanical behavior of a particular woven metal matrix composite (MMC); 8-harness (8H) satin carbon/copper (C/Cu). This is accomplished via mechanical testing as well as micromechanical modeling. While the literature is replete with experimental and modeling efforts for woven and braided polymer matrix composites, little work has been done on woven and braided MMC's. Thus, the development and understanding of woven MMC's is at an early stage. 8H satin C/Cu owes its existence to the high thermal conductivity of copper and low density and thermal expansion of carbon fibers. It is a candidate material for high heat flux applications, such as space power radiator panels. The experimental portion of this investigation consists of monotonic and cyclic tension, compression, and Iosipescu shear tests, as well as combined tension-compression tests. Tests were performed on composite specimens with three copper matrix alloy types: pure Cu, Cu-0.5 weight percent Ti (Cu-Ti), and Cu-0.7 weight percent Cr (Cu-Cr). The small alloying additions are present to promote fiber/matrix interfacial bonding. The analytical modeling effort utilizes an approach in which a local micromechanical model is embedded in a global micromechanical model. This approach differs from previously developed analytical models for woven composites in that a true repeating unit cell is analyzed. However, unlike finite element modeling of woven composites, the geometry is sufficiently idealized to allow efficient geometric discretization and efficient execution.

  13. Evaluation of effective thermal diffusivity and conductivity of fibrous materials through computational micromechanics

    NASA Astrophysics Data System (ADS)

    Ahmadi, Isa

    2017-01-01

    The aim of present study is to investigate the effective thermal properties of composite material via micromechanical modeling of the composite material as a heterogeneous material. These properties mainly include the thermal diffusivity and the thermal conductivity of composites. For this purpose, a definition is presented for effective thermal diffusivity for heterogeneous materials based on heat diffusion rate into the material in a transient heat transfer. A micromechanical model based on the Representative Volume Element (RVE) is presented for modeling the heat conduction in the fibrous composite materials. An appropriate heat transfer problem for the RVE is defined so that by the analogy of the numerical results the effective properties of the RVE can be estimated. A numerical method is employed to analyze the steady-state and transient heat flux and temperature in the RVE. To validate the model, the predictions of present model are compared with results of analytical method, FEM and some available experimental data in the open literature. The effective thermal conductivity and thermal diffusivity are then obtained for fibrous composites via the present micromechanical model. The SiC/Ti, SiC/Ti6%Al4%V and Glass/Epoxy composites with various fiber volume fractions are considered in this study.

  14. An extended micromechanics method for probing interphase properties in polymer nanocomposites [An extended micromechanics method for overlapping geometries with application to polymer nanocomposites

    DOE PAGES

    Liu, Zeliang; Moore, John A.; Liu, Wing Kam

    2016-05-03

    Inclusions comprised on filler particles and interphase regions commonly form complex morphologies in polymer nanocomposites. Addressing these morphologies as systems of overlapping simple shapes allows for the study of dilute particles, clustered particles, and interacting interphases all in one general modeling framework. To account for the material properties in these overlapping geometries, weighted-mean and additive overlapping conditions are introduced and the corresponding inclusion-wise integral equations are formulated. An extended micromechanics method based on these overlapping conditions for linear elastic and viscoelastic heterogeneous material is then developed. An important feature of the proposed approach is that the effect of both themore » geometric overlapping (clustered particles) and physical overlapping (interacting interphases) on the effective properties can be distinguished. Lastly, we apply the extended micromechanics method to a viscoelastic polymer nanocomposite with interphase regions, and estimate the properties and thickness of the interphase region based on experimental data for carbon-black filled styrene butadiene rubbers.« less

  15. Sediment micromechanics in sheet flows induced by asymmetric waves: A CFD-DEM study

    NASA Astrophysics Data System (ADS)

    Sun, Rui; Xiao, Heng

    2016-11-01

    Understanding the sediment transport in oscillatory flows is essential to the investigation of the overall sediment budget for coastal regions. This overall budget is crucial for the prediction of the morphological change of the coastline in engineering applications. Since the sediment transport in oscillatory flows is dense particle-laden flow, appropriate modeling the particle interaction is critical. Although traditional two-fluid approaches have been applied to the study of sediment transport in oscillatory flows, the approaches do not capture the interaction of the particles. The study of the motion of individual sediment particles and their micromechanics (e.g., packing and contact force) in oscillatory flows is still lacking. In this work, a parallel CFD-DEM solver SediFoam that can model the inter-particle collision is applied to study the granular micromechanics of sediment particles in oscillatory flows. The results obtained from the CFD-DEM solver are validated by using the experimental data of coarse and medium sands. The comparison with experimental results suggests that the flow velocity, the sediment flux and the net sediment transport rate predicted by SediFoam are satisfactory. Moreover, the micromechanic quantities of the sediment bed are presented in detail, including the Voronoi concentration, the coordination number, and the particle interaction force. It is demonstrated that the variation of these micromechanic quantities at different phases in the oscillatory cycle is significant, which is due to different responses of the sediment bed. To investigate the structural properties of the sediment bed, the correlation of the Voronoi volume fraction and coordination number is compared to the results from the fluidized bed simulations. The consistency in the comparison indicates the structural micromechanics of sediment transport and fluidized bed are similar despite the differences in flow patterns. From the prediction of the CFD-DEM model, we

  16. Analytic and computational micromechanics of clustering and interphase effects in carbon nanotube composites.

    SciTech Connect

    Seidel, Gary D.; Hammerand, Daniel Carl; Lagoudas, Dimitris C.

    2006-01-01

    Effective elastic properties for carbon nanotube reinforced composites are obtained through a variety of micromechanics techniques. Using the in-plane elastic properties of graphene, the effective properties of carbon nanotubes are calculated utilizing a composite cylinders micromechanics technique as a first step in a two-step process. These effective properties are then used in the self-consistent and Mori-Tanaka methods to obtain effective elastic properties of composites consisting of aligned single or multi-walled carbon nanotubes embedded in a polymer matrix. Effective composite properties from these averaging methods are compared to a direct composite cylinders approach extended from the work of Hashin and Rosen (1964) and Christensen and Lo (1979). Comparisons with finite element simulations are also performed. The effects of an interphase layer between the nanotubes and the polymer matrix as result of functionalization is also investigated using a multi-layer composite cylinders approach. Finally, the modeling of the clustering of nanotubes into bundles due to interatomic forces is accomplished herein using a tessellation method in conjunction with a multi-phase Mori-Tanaka technique. In addition to aligned nanotube composites, modeling of the effective elastic properties of randomly dispersed nanotubes into a matrix is performed using the Mori-Tanaka method, and comparisons with experimental data are made. Computational micromechanical analysis of high-stiffness hollow fiber nanocomposites is performed using the finite element method. The high-stiffness hollow fibers are modeled either directly as isotropic hollow tubes or equivalent transversely isotropic effective solid cylinders with properties computed using a micromechanics based composite cylinders method. Using a representative volume element for clustered high-stiffness hollow fibers embedded in a compliant matrix with the appropriate periodic boundary conditions, the effective elastic properties

  17. Application of reference point indentation for micro-mechanical surface characterization of calcium silicate based dental materials.

    PubMed

    Antonijević, Djordje; Milovanović, Petar; Riedel, Christoph; Hahn, Michael; Amling, Michael; Busse, Björn; Djurić, Marija

    2016-04-01

    The objective of this study was to elucidate micromechanical properties of Biodentine and two experimental calcium silicate cements (CSCs) using Reference Point Indentation (RPI). Biomechanical characteristics of the cement type and the effects of a radiopacifier, liquid components, acid etching treatment and bioactivation in simulated body fluid (SBF) were investigated by measuring the microhardness, average unloading slope (Avg US) and indentation distance increase (IDI). Biodentine had a greater microhardness than the experimental CSCs, while the Avg US and IDI values were not significantly different among investigated materials. There was a statistically significant difference in microhardness and IDI values between pure CSCs and radiopacified cements (p < 0.05). Micromechanical properties were not affected by different liquid components used. Acid-etching treatment reduced Biodentine's microhardness while cements' immersion in SBF resulted in greater microhardness and higher IDI values compared to the control group. Clearly, the physiological environment and the cements' composition affect their surface micromechanical properties. The addition of calcium chloride and CSCs' immersion in SBF are beneficial for CSCs' micromechanical performance, while the addition of radiopacifiers and acid etching treatment weaken the CSCs' surface. Application of RPI aids with the characterization of micromechanical properties of synthetic materials' surfaces.

  18. JPRS Report, East Europe.

    DTIC Science & Technology

    2007-11-02

    rent news and information and is published Monday through Friday in 8 volumes: China, East Europe, Soviet Union, East Asia, Near East & South Asia...JPRS-EER-87-141 23 SEPTFMRFR 1QS7 u etc* U ü J. Ma M i%\\ ■■■■■« FOREIGN BROADCAST INFORMATION SERVICE JPRS Report— East Eur ft e N9BQ6W M...EER-87-141 23 SEPTEMBER 1987 EAST EUROPE CONTENTS POLITICAL INTRABLOC Romanian Efforts To Weaken Minority Magyar Position Viewed (Martti Valkonen

  19. Doctoring in Eastern Europe

    PubMed Central

    Wilde, Henry

    1983-01-01

    Health care in Eastern Europe has not achieved world standards nor the goals of planners of socialist societies. With luck, perseverance, bribes or good connections, it is possible to obtain good medical and surgical care in Eastern Europe for a major illness. Primary and even secondary care usually are substandard, however, and often completely unacceptable to most Western foreigners. The reasons for this are complex but mainly rooted in different attitudes of health workers towards their patients, poor physical plants, poor salary structures, inadequate advancement opportunities for health care workers, poor social status and professional recognition for nurses and almost complete isolation of the average primary care doctor from hospital medicine. PMID:6659504

  20. Effect of low doses beta irradiation on micromechanical properties of surface layer of injection molded polypropylene composite

    NASA Astrophysics Data System (ADS)

    Manas, David; Manas, Miroslav; Gajzlerova, Lenka; Ovsik, Martin; Kratky, Petr; Senkerik, Vojtěch; Skrobak, Adam; Danek, Michal; Manas, Martin

    2015-09-01

    The influence of beta radiation on the changes in the structure and selected properties (mechanical and thermal) was proved. Using low doses of beta radiation for 25% glass fiber filled polypropylene and its influence on the changes of micromechanical properties of surface layer has not been studied in detail so far. The specimens of 25% glass fiber filled PP were made by injection molding technology and irradiated by low doses of beta radiation (0, 15 and 33 kGy). The changes in the microstructure and micromechanical properties of surface layer were evaluated using FTIR, SEM, WAXS and instrumented microhardness test. The results of the measurements showed considerable increase in micromechanical properties (indentation hardness, indentation elastic modulus) when low doses of beta radiation are used.