6 research outputs found
Resistencia al desprendimiento de brackets cementados con la técnica directa e indirecta
Get PDFIntroducción: una de las mas grandes aportaciones en la Ortodoncia fue por Buonocore que introdujo la técnica de grabado ácido y Newman que implemento el cementado directo de brackets. Debido a que la técnica de cementado directo a veces no permitía la colocación correcta de los brackets y la contaminación por humedad era muy común fue que Silverman y Cohen introdujeron el método de cementado indirecto, el cual ofrece mayor precisión en la colocación, mayor eficiencia durante el operatorio y la comodidad del paciente. Objetivo: Determinar la resistencia al desprendimiento de brackets cementados mediante técnica directa e indirecta. Materiales y Métodos: se analizaron 60 premolares humanos extraídos, con brackets American Orthodontics, cementados con resina de fotocurado Transbond PLUS® (3M Unitek). Los gruposestuvieron conformados por 40 dientes humanos para el grupo control (técnica directa) y 20 para el grupo experimental (técnica indirecta). Los cuales después de haber sido preparados se colocaron en una máquina MTS Landmark Servohydraulic Test System® que realizo la tracción, para evaluar cual de las 2 técnicas presentaba mayor resistencia al desprendimiento. Se utilizo el programa SPSS (Statistical Package of the Social Sciences®, versión 15) para las pruebas estadísticas, se realizó el método estadístico no paramétrico de KOLMOGOROV-SMIRNOV para probar la normalidad. Al ser normal se utilizo el análisis de varianza con un factor ANOVA para comparar las medias entre los dos grupos. Resultados: los resultados obtenidos fueron que el grupo control presento una fuerza al desprendimiento de 78.80N, con una desviación estándar de 29.73, y el grupo experimental una fuerza al desprendimiento de 65.87N, con una desviación estándar de 31.403, se realizo el análisis de varianza de un factor para la comparación de las medias, y se encontró que no existe diferencia significativa (F=2.431, p> 0.05) entre los grupos. Discusión: por lo tanto nuestro estudio coincide con algunos autores como Polat, Linn, Milne y Hocevar y Howard F. Vincent, quienes tampoco encontraron diferencias significativas entre la resistencia al desprendimiento de brackets cementados con ambas técnicas. Conclusiones: Los brackets cementados con ambas técnicas ofrecen la misma resistencia a la tracción
The Keyboard Concertos of James Hook and Johann Christian Bach
No full text44 p.Discusses the social context of 18th Century music in England; the biographies of Hook and J. C. Bach; and the musical interpretation of the "galant" style concertos performed by the author
The Keyboard Concerto in London Society, 1760-1790. (Volumes I and II) (Engl and ).
No full textThis dissertation discusses the uses of the keyboard concerto made by professional and amateur musicians in London between 1760 and 1790. The period studied begins after H and el's death in 1759 and ends with Haydn's arrival in London in 1791. The author identifies the thirteen English, four German, and three Italian concerto composers who lived in London in those years and the concertos they published there for harpsichord, organ, or pianoforte. The English composers are discussed in extensive biographies, which include new information from primary sources. The lives of these composers, intersecting at some points and widely divergent at others, serve as a focal point for an assessment of musical life in London during that time. Keyboard concertos were played, often by virtuoso performers, on some of Europe's best keyboard instruments at oratorio productions (a practice begun by H and el), and also at public and private concerts, at the pleasure gardens, at court, and even in domestic settings. The frequency with which concertos were performed in the homes of eighteenth-century Londoners, either as solo pieces or with only a few accompanying instruments, demonstrates that the genre often was considered to be chamber music. Many of these concertos seem to have been written specifically for that purpose, since they often had accompaniments of strings in three parts, and since the keyboard parts were published in a format that made solo performance possible. Keyboard parts and other evidence indicate that the soloist played basso continuo during the tutti sections. In drawing up this profile of the concerto's function in late eighteenth-century London, the author has relied as much as possible on the primary sources, which include: (1) contemporary London newspapers; (2) contemporary periodicals; (3) diaries and memoirs of eighteenth-century musicians, especially those of R. J. S. Stevens, John March, and Samuel Wesley; (4) published period accounts, including, for example, Friedrich Wendeborn, View of Engl and (1792), Charlotte Papendiek, Court and Private Life (published posthumously, 1887), and others; and (5) collections of pleasure gardens memorabilia, housed at the British Museum and at the Minet Library, London. These sources, indispensable to an underst and ing of English musical life, provide the main focus of this study.PhDMusicUniversity of Michiganhttp://deepblue.lib.umich.edu/bitstream/2027.42/161488/1/8712246.pd
THE MEAASUREMENT OF AMBIENT BY CAVITY RING-DOWN SPECTROSCOPY
No full textAuthor Institution: Department of Chemistry and Air Pollution Research Center, University of California; Department of Chemistry, Calvin CollegeNitrogen dioxide is a principle component of photochemical smog that is present in polluted atmospheres at the parts per billion (ppb) level. In this work, cavity ring-down spectroscopy (CRDS) is utilized for the detection of ambient . Sub ppb limit of detection is routinely achieved. Experimental approaches to remove the particulates and to improve the detection limit and accuracy are investigated. Ambient measurements of by CRDS are evaluated, and are compared side by side with the measurements by chemiluminescence analysis
The Disputes Between Sibawayh and Abu'l-Hasan al-Ahfesh in the Frame of Ibn Hisham's work named Mughni al-Labib 'an Kutubi'l-E'arib
Get PDFİbn Hişâm, uzun bir tahsil hayatı neticesinde elde ettiği bilgi birikimini, kaleme aldığı el-İ?râb ?an ?avâ?idi’l-i?râb adlı risâlesine aktararak İslâmî ilimler alanına önemli bir kaynak kazandırmıştır. Nahiv alanında telif edilen bu eser, içerdiği meseleler ve konuların işleyiş tarzı bakımından ön plana çıkarak birçok âlim tarafından takdirle karşılanmıştır. Müellif, bu risâlesinin tasnif ve metodunu esas alarak Mugni’l-lebîb adında bir eser kaleme almıştır. İbn Hişâm, bu eserinde literatür ile ilgili bazı meseleler hakkında detaylı bilgi aktarmak adına dilciler arasında vaki olan ihtilaflara değinmektedir. Çalışmamızın temel konusunu, Sîbeveyh ve öğrencisi Ebu’l-Hasan el-Ahfeş arasında meydana gelen ihtilaflar teşkil etmektedir. Sîbeveyh ve Ahfeş arasında cereyan eden ihtilaflar ????’nın fiil ya da harf olması, ?’ın isim veya harf olması, ?????’nin zarf veya isim olarak gelmesi, ??? ve ???? sözcüklerinin sonuna zamirin bitişmesi, ?’nın cümlede zâide gelmesi, ??’nın isminin müfred şeklinde gelmesi durumunda amilinin tesbiti ve bazı kelimelerin i?râbı gibi konular çerçevesinde şekillenmektedir. İbn Hişâm, yukarıda geçen meselelerde bazen herhangi bir değerlendirmede bulunmazken kimi zaman da Sîbeveyh ve Ahfeş’e ait görüşleri tercih etmektedir. Ebû ?Alî Kutrub ve Ebû Ömer el-Cermî gibi dilbilimciler ise Sîbeveyh ve Ahfeş arasındaki ihtilafların neredeyse tamamında Ahfeş’e tabi olmuşlardır. Ancak nadiren de olsa Sîbeveyh’in görüşü kimi konularda Ahfeş’in görüşüne tercih edilmektedir.Ibn Hisham has brought an important source to the field of Islamic sciences by transferring the knowledge he gained as a result of a long education life to his epistle called al-İ?râb ?an kavâ?idi'l-i?râb. The work, which was copyrighted in the field of syntax, was appreciated by many scholars by coming to the forefront in terms of the issues it contains and the way it handles the subjects. Thus, the author wrote a work called Mughni al-Labib based on the classification and method of this treatise. In this work, Ibn Hisham touches on the conflicts between linguists in order to provide detailed information about some issues related to the literature. The main subject of our study is the conflicts between the related linguists Sibawayh and Abu'l-Hasan al-Ahfesh. Conflicts between Sibawayh and Ahfesh are shaped within the framework of issues such as: ???? is verb and letter, ? is noun and letter, ????? comes as adverb or noun, the words ??? and ???? are used as pronouns, ? comes in the form of zaide in a sentence, ?? whichs is in the form of müfred and the i?râb of some words. While Ibn Hisham sometimes does not make any evaluations on the above-mentioned issues, he sometimes chooses between Sibawayh and Ahfesh. Linguists such as Abu Ali Qutrub and Abu Amr al-Cirmi were subject to Ahfesh in almost all of the conflicts between Sibawayh and Ahfesh. However, although rarely, Sibawayh's view is preferred to Ahfeş's view on some issues
Resistencia al desprendimiento de brackets cementados con la técnica directa e indirecta.
Get PDFObjetivo: realizar una revisión bibliográfica para conocer la resistencia al desprendimiento de brackets cementados mediante técnica directa e indirecta.Materiales y Métodos: se obtuvo realizando una búsqueda electrónica,en base a palabras claves o títulos relacionados. Los artículos fueron seleccionados y ordenados por grado de importancia. Se incluyeron artículos que hablaran de la resistencia al desprendimiento de bracketscementados con la técnica directa e indirecta. Ambas técnicas de cementado tienen sus ventajas y desventajas y es relativamente imposible determinar que una sea mejor que la otra.Resultados: los autores que se revisaron nos indican que no existen diferencias significativas en cuanto a la resistencia al desprendimiento debrackets cementados con una u otra técnica.Conclusión: es recomendable seguir una ardua búsqueda de literaturapara poder determinar con mayor claridad que técnica nos brinda mayor efectividad
