Understanding the Shape-Memory Alloys Used in Orthodontics

Nickel-titanium (NiTi) shape-memory alloys (SMAs) have been used in the manufacture of orthodontic wires due to their shape memory properties, super-elasticity, high ductility, and resistance to corrosion. SMAs have greater strength and lower modulus of elasticity when compared with stainless steel alloys. The pseudoelastic behavior of NiTi wires means that on unloading they return to their original shape by delivering light continuous forces over a wider range of deformation which is claimed to allow dental displacements. The aim of this paper is to discuss the physical, metallurgical, and mechanical properties of NiTi used in Orthodontics in order to analyze the shape memory properties, super-elasticity, and thermomechanical characteristics of SMA

Force Relaxation Characteristics of Medium Force Orthodontic Latex Elastics: A Pilot Study

To evaluate force extension relaxation of different brands and diameters of latex elastics subjected to static tensile testing under an apparatus designed to simulate oral environments, sample sizes of 5 elastics from American Orthodontics (AO), Tp, and Morelli Orthodontics (Mo) of equivalent medium force, (3/16, 1/4, and 5/16 inch size) were tested. The forces were read after 1-, 3-, 6-, 12- and 24-hour periods in Emic testing machine with 30 mm/min cross-head speed and load cell of 20 N. Two-way ANOVA and Bonferroni tests were used to identify statistical significance. There were statistically differences among different manufacturers at all observation intervals (P < 0.0001). The relationships among loads at 24-hour time period were as follows: Morelli>AO>Tp for 3/16, 1/4, and 5/16 elastics. The force decay pattern showed a notable drop-off of forces until 3 hours, a slight increase in some groups from 3–6 hours and a more homogeneous force pattern over 6–24 hours

Anomalous Strain Rate Effect in Ultrafine Grained Titanium

An anomalous effect was found in the strain rate dependence of severe plastic deformed commercially pure titanium with ultrafinegrained structure. A maximum tensile strength was obtained for ϵ˙=10−3s−1. This did not allow a single strain rate sensitivity parameter to be defined in the interval from ϵ˙=10−5to10−1s−1. Distinct deformation mechanisms for lower and higher strain rates might be the reason for this anomaly

Memórias da Infância e da Educação: abordagens eliasianas sobre as mulheres

Relações sociais entre indivíduos estão pautadas pela experiência de educação e formação que cada um traz consigo ao longo da vida, pelo modo como se constituem individual e coletivamente. A partir de Elias e da metodologia da história oral, o objetivo foi buscar nas memórias de infância de sete mulheres, professoras de crianças, nascidas entre 1950 e 1970, a formação e a educação que se constituiu na infância em espaços privados e domésticos. Apreendeu-se que a escolha profissional tem vínculos com a educação feminina, normatizada por regras de controle e civilidade

The Validity of Bicep Located Heart Rate Monitors During Running

Running is a popular sport with 621 million people participating worldwide. Heart rate (HR) is a way to determine intensity but many people do not want to wear a HR strap around their chest because it is uncomfortable and can cause chaffing. An alternative location for determining HR could be the biceps but the validity of such devices need to be determined. PURPOSE: To determine the validity of the Polar OH 1 and Polar Verity biceps devices during self-paced running. METHODS: Wearing Polar OH1, Polar Verity, and Polar H10 (criterion) 5 female and 5 male participants were asked to perform running for 5 minutes up and down a 100 ft hallway. The average HR and maximal HR over the run was recorded in beats per minute (bpm). Validity was determined using mean absolute percent error (MAPE) and Lin\u27s concordance (CCC), with a threshold of less than 10% and greater than 0.70 respectively. The threshold for both was required to be met to be considered valid. RESULTS: Average HR returned from the devices was: Polar H10 = 154.6 (16.3) [mean (standard deviation)], Polar OH1 = 152.0 (16.2), and Polar Verity = 151.1 (16.5) bpm. The average HR MAPE for the Polar OH1 and the Polar Verity was 12.2% and 12.6%, respectively, and the CCC for each device was 0.94 and 0.90. Maximal HR returned from the devices was: Polar H10 = 174.2 (18.1), Polar OH1 = 171.8 (18.8), and Polar Verity = 167.2 (35.1) bpm. The maximal HR MAPE for the Polar OH1 and the Polar Verity was 1.3% and 4.2%, respectively. The CCC for each device was 0.93 and 0.43, respectively. CONCLUSION: We evaluated whether HR monitors located on the biceps could return accurate measures. Neither device met both thresholds when average HR was considered. Because the Polar OH 1 satisfied both thresholds for maximal HR, we conclude it to be the more accurate device for use during running. These results should be used with caution until further improvements in biceps located devices can be made to return valid measures for both average and maximal heart rate

Dise?o de un plan de negocios para una empresa de servicios de estancia y club de d?a para adultos mayores en los NSE B y C en Lima Metropolitana

En el presente trabajo, se busca determinar la viabilidad comercial, operativa y econ?mica, as? como las estrategias para la implementaci?n del servicio de Estancia y Club de D?a para adultos mayores en los NSE B y C. El Servicio del Club operar? en un local de 1,600mts, su infraestructura estar? dise?ada seg?n las condiciones f?sicas de los adultos mayores; en donde se realizar?n diversas actividades f?sicas, l?dicas y mentales, en un ambiente divertido a fin de mantener al m?ximo sus facultades durante el proceso de envejecimiento. Pensando en aquellos adultos mayores que requieren de asistencia en sus actividades diarias, pero deseoso de socializar, se ha pensado en el servicio de ?Estancia? que adem?s de los anteriormente descritos se brindar? el servicio de cuidado no medico asistido por enfermeras

Toxoplasma gondii seropositivity associated to peri-urban living places in pregnant women in a rural area of Buenos Aires province, Argentina

Infection with Toxoplasma gondii is very common in humans throughout the world, the intake of raw or undercooked meat with tissue cysts and fruits, vegetables and water contaminated with parasite oocysts being the main routes of infection. Here, we analyzed the seroprevalence of anti-T. gondii antibodies in pregnant females (age 13–44 years; n = 920) between April 2014 and December 2017 from Chascomús (Argentina), a city immersed in a rural area. Altogether 320 tested positive for immunoglobulin G antibodies, yielding an overall seroprevalence of 34.8% (CI 95%: 31.7–37.9). No association was observed between seropositivity and age. In addition, by using the QGIS 3.2.1 software we analyzed the geographical distribution of 769 (83.6%) pregnant females in two main areas of the city: Urban (n = 157) and Peri-urban (n = 612) with a seroprevalence of 26.8% (CI 95%: 19.8–33.7) and 36.4% (CI 95%: 32.6–40.3) respectively, and this difference was statistically significant (p = 0.023). Furthermore, we assessed through a questionnaire survey, between April 2016 to December 2017, possible risk factors such as activity (urban and rural), home water supply, animal husbandry, presence of cats as pets, gardening and consumption of meat and its derivatives (pork, sheep meat and sausages) and their frequencies (consumption per week), not finding significant association with seropositivity. Significant differences was found when the seroprevalence was analyzed between the urban and peri-urban neighborhoods of the city of Chascomús. The higher seroprevalence in peri-urban neighborhoods could be due to an unfavorable socioeconomic situation and/or to undeveloped peri-urban environments, which is a risk factor that should be taken into account when planning the health care of pregnant females.Fil: Rivera, Elias Maximiliano. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús). Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús); ArgentinaFil: Lavayén, Silvina N.. Dirección Nacional del Instituto de Investigación. Administración Nacional de Laboratorio e Instituto de Salud "Dr.C.G.Malbran". Instituto Nacional de Epidemiologia; ArgentinaFil: Sánchez, Paola. Hospital Municipal de Chascomus San Vicente de Paul; ArgentinaFil: Martins, Carlos M. A.. Hospital Municipal de Chascomus San Vicente de Paul; ArgentinaFil: Gómez, Etelvina. Hospital Municipal de Chascomus San Vicente de Paul; ArgentinaFil: Rodríguez, Jorge P.. Hospital Municipal de Chascomus San Vicente de Paul; ArgentinaFil: Arias, Marcela E.. Secretaría de Salud. Municipalidad de Chascomús; ArgentinaFil: Silva, Andrea Paula. Dirección Nacional del Instituto de Investigación. Administración Nacional de Laboratorio e Instituto de Salud "Dr.C.G.Malbran". Instituto Nacional de Epidemiologia; ArgentinaFil: Ángel, Sergio Oscar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús). Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús); Argentin

Fauna de abelhas nativa em plantações de tomate : uma comparação de métodos de amostragem ativa e de armadilha

O tomate é amplamente cultivado em todo o mundo e requer polinização por abelhas nativas ou manejadas para realizar o pleno potencial de produção dos frutos. Para investigar a riqueza e abundância de espécies de abelhas nativas em plantações de tomate do Centro-Oeste do Brasil, dois métodos de amostragem (armadilhas pan-trap e amostragem ativa) foram utilizados em nove propriedades de junho a setembro de 2011. Um total de 465 indivíduos de 44 espécies foi coletado. A composição das espécies de abelhas amostradas diferiu dependendo do método utilizado. Vinte e duas espécies foram capturadas exclusivamente em armadilhas, 13 outras por meio de amostragem ativa e nove por ambos os métodos. A maioria das espécies de abelhas capturadas neste estudo pode ser considerada polinizadores eficazes do tomate, porque elas podem executar a polinização por vibração. Vibrando seus músculos torácicos, essas abelhas podem liberar o pólen das anteras para seus próprios corpos e para os estigmas da mesma flor, uma vez que eles estão dentro do cone de anteras da variedade do tomate estudado. Ambos os métodos amostraram espécies exclusivas de abelhas vibradoras. No entanto, as armadilhas capturaram abelhas vibradoras e não vibradoras indiscriminadamente e o método ativo amostrou principalmente a abelha vibradora. As coletas utilizando armadilhas e amostragens ativas foram complementares. O uso de apenas um método de amostragem não fornece um entendimento completo da riqueza de espécies de polinizadores de tomate no campo.The tomato is widely cultivated throughout the world and requires pollination by wild or managed bees to realize its full-potential fruit production. Two different sampling methods (pan trapping and active sampling) were employed in nine different properties from June to September of 2011 to investigate the richness and abundance of native bee species present in tomato crops of Center-West Brazil. A total of 465 individuals of 44 species were collected, with the composition of sampled bee species differing between the methods used. Twenty-two species were exclusively captured in pan traps, 13 others through active sampling and nine by both methods. Most of the sampled bee species can be considered effective pollinators of the tomato because they can perform buzz-pollination. By vibration, these bees can liberate pollen from anthers into the air or onto their own bodies and the stigmas of the same flower because the stigmas of the studied tomato variety are within the anther cone. Both methods exclusively sampled some species of buzz-pollinating bees, however, pan-trapping captured buzzing and non-buzzing visitors indiscriminately while active sampling captured more buzzing bees. Pan-trapping and active sampling appear to complement each other, and so the use of only one or the other would not provide a full understanding of the species richness of tomato pollinators in the field

ESTABILIDADE AERÓBIA DE CANA-DE-AÇÚCAR IN NATURA HIDROLISADA COM CAL VIRGEM

Objetivou-se com esta pesquisa avaliar o efeito da inclusão de cal virgem sobre a estabilidade aeróbia da cana-de-açúcar in natura. O trabalho foi conduzido na Faculdade de Zootecnia da UNIFENAS, sob delineamento experimental inteiramente casualizado, em esquema fatorial 4 x 5, avaliando-se quatro doses de cal (0,0; 0,5; 1,0 e 2,0 % em relação à matéria natural) e cinco tempos de exposição aeróbia (0, 12, 24, 48 e 72 horas após o momento da hidrólise), com quatro repetições. A inclusão do aditivo na cana-de-açúcar in natura provocou aumento no teor de matéria seca e nos valores de pH. Porém, os valores de pH diminuíram com o decorrer do tempo, em função da ação de microrganismos. Em relação à temperatura, esta aumentou quando se adicionou 1,0% de cal à cana-de-açúcar; no entanto, o menor valor referente ao acúmulo da temperatura durante as aferições foi obtido com a utilização de 2,0% de cal, e da mesma forma, a menor taxa de aquecimento foi obtida para este mesmo tratamento. De certa forma, a utilização de 2,0% de cal virgem aumentou a estabilidade aeróbia da cana-de-açúcar, porém, todos os tratamentos apresentaram instabilidade aeróbia poucas horas após o momento da mistura entre cal e cana-de-açúcar. PALAVRAS-CHAVE: alcalinização; óxido de cálcio; pH; temperatura

Calculations of binding energies and masses of heavy quarkonia using renormalon cancellation

We use various methods of Borel integration to calculate the binding ground energies and masses of b-bbar and t-tbar quarkonia. The methods take into account the leading infrared renormalon structure of the hard+soft part of the binding energies E(s), and of the corresponding quark pole masses m_q, where the contributions of these singularities in M(s) = 2 m_q + E(s) cancel. Beforehand, we carry out the separation of the binding energy into its hard+soft and ultrasoft parts. The resummation formalisms are applied to expansions of m_q and E(s) in terms of quantities which do not involve renormalon ambiguity, such as MSbar quark mass, and alpha_s. The renormalization scales are different in calculations of m_q, E(s) and E(us). The MSbar mass of b quark is extracted, and the binding energies of t-tbar and the peak (resonance) energies for (t+tbar) production are obtained.Comment: 23 pages, 8 double figures, revtex4; the version to appear in Phys.Rev.D; extended discussion between Eqs.(25) and (26); the paragraph between Eqs.(32) and (33) is new and explains the numerical dependence of the residue parameter on the factorization scale; several new references were added; acknowledgments were modified; the numerical results are unchange