309 research outputs found
The QUAX proposal: a search of galactic axion with magnetic materials
Aim of the QUAX (QUaerere AXion) proposal is to exploit the interaction of
cosmological axions with the spin of electrons in a magnetized sample. Their
effect is equivalent to the application of an oscillating rf field with
frequency and amplitude which are fixed by axion mass and coupling constant,
respectively. The rf receiver module of the QUAX detector consists of
magnetized samples with the Larmor resonance frequency tuned to the axion mass
by a polarizing static magnetic field. The interaction of electrons with the
axion-equivalent rf field produces oscillations in the total magnetization of
the samples. To amplify such a tiny field, a pump field at the same frequency
is applied in a direction orthogonal to the polarizing field. The induced
oscillatory magnetization along the polarizing field is measured by a SQUID
amplifier operated at its quantum noise level.Comment: 5 pages, Contribution for the proceedings of the TAUP2015,
International Conference on Topics in Astroparticle and Underground Physics,
7-11 September 2015, Torino, Ital
Estudo paramétrico de estacas carregadas transversalmente por modelação computacional
Dupla diplomação com a Universidade Tecnológica Federal do Paraná - UTFPRA geotecnia é uma das áreas da engenharia que mais dependem de métodos de análise empÃricos; isso se deve ao fato de o solo ser um material heterogêneo, além de que os métodos de sondagens atuais são baseados em amostras pouco representativas do volume total de solo. Por isso, há muito mais variáveis envolvidas e menos confiabilidade na estimativa da capacidade de carga da estrutura. Assim sendo, é necessário verificar a validade e as particularidades dos métodos de análise a fim de que, cada vez mais, representem as caracterÃsticas do solo e gerem resultados com mais precisão. Nesse sentido, esta dissertação teve como objetivo a análise computacional bidimensional dos efeitos do carregamento axial e transversal (simultâneos) de estacas isoladas, moldadas e de concreto armado. Além disso, levaram-se em consideração os diferentes tipos de solos, as dimensões da estaca, bem como a estratigrafia, as condições de drenagem e os parâmetros mecânicos do solo. Para tal, foram verificados e comparados os resultados obtidos para a capacidade de carga axial pelo método da NAVFAC DM 7.2, para o assentamento pelos métodos de Poulos & Davis (1980) e Masopust (1994), assim como para a distribuição dos esforços e deslocamentos horizontais pelo método p-y, baseada na estimativa do módulo de reação horizontal obtida a partir das abordagens teóricas de Bowles (1997), Vesic (1977), CSN 73 1004, Pochman & Simek (1989) e Matlock & Reese (1956). Com a finalização dos estudos, concluiu-se que, em relação à capacidade de carga axial pelo método da NAVFAC 7.2 DM, em solo composto por areia média, quanto menor o diâmetro e maior o comprimento da estaca, maior é a capacidade de carga por volume escavado. Em argila mole e argila dura em condição não drenada, quanto menores o diâmetro e o comprimento, mais eficiente é a estaca. Em argila mole e argila dura em condição drenada, é sempre mais válido aumentar o comprimento que o diâmetro da estaca. Quanto ao assentamento de estacas pelo método de Poulos & Davis (1980), notou-se que em todos os casos a carga de mobilização do atrito lateral e seu respectivo assentamento são ligeiramente maiores para estacas de ponta se comparada à flutuante. No que se refere ao assentamento pelo método de Masopust (1994), constatou-se que a inclinação da curva carga-assentamento é principalmente dependente do diâmetro, enquanto que o comprimento influencia, sobretudo, na amplitude horizontal da curva. Acerca da distribuição dos esforços e deslocamentos horizontais pelo método p-y, percebeu-se que os resultados são mais dependentes do diâmetro que do comprimento da estaca e o formato das curvas de distribuição de esforços e deformações tende a ser semelhante para estacas de mesmo diâmetro, sendo a variação de comprimento percebida por ligeira translação do gráfico. A influência das condições de drenagem, dos parâmetros mecânicos do solo e das diferentes abordagens teóricas varia consoante o caso de estudo.Geotechnics is one of the engineering areas that most depend on methods based on empirical analysis due to the fact that soils are homogeneous materials and the current survey methods are based on samples that still do not represent satisfactorily the total volume of soil. Therefore, there are many more variables involved and less reliability in estimating the load capacity of the structures. So that, it is necessary to keep verifying the validity and the particularities of these methods of analysis to better represent the soil’s characteristics and to generate results with more precision. In this sense, the objective of this study is to develop a two-dimensional computational analysis of the axial and transverse (simultaneous) loading effects on isolated, bored and reinforced concrete piles. In addition, different types of soil, piles dimensions, soil stratigraphy, drainage conditions and soil mechanical parameters were considered as variables of this study. Thereby, the axial load capacity of piles was verified by the method of NAVFAC DM 7.2, the settlement by the methods of Poulos & Davis (1980) and Masopust (1994), and the distribution of horizontal forces and displacements by the p-y method, based on the horizontal reaction modulus obtained from the theoretical approaches by Bowles (1997), Vesic (1977), CSN 73 1004, Pochman & Simek (1989) and Matlock & Reese (1956). From the axial load capacity analysis, it was concluded that in soils composed of medium sand, the smaller the diameter and the greater the length, the higher is the pile load capacity per volume. In soils composed of soft clay and hard clay in undrained condition, the smaller the diameter and length, the more efficient the pile is. In soils composed of soft clay and hard clay in drained condition, it is always better to increase the length rather than the pile diameter. Regarding to the pile settlement by Poulos & Davis (1980), it was noticed that in all study cases the mobilization load of the lateral friction and its respective settlement are slightly larger for tip piles if compared to floating ones. In relation to the settlement by Masopust (1994), it was found that the slope of the load-settlement curves is mainly dependent on the diameter, whereas the length most influences its horizontal amplitude. Regarding to the distribution of lateral stresses and displacements by the p-y method, it was noticed that the results are more dependent on the diameter rather than the pile length. Moreover, the shape of the stress distribution curves tends to be similar for piles with the same diameter, whereas the length variation is perceived by a slight translation of the graph. The influence of the drainage conditions, the soil’s mechanical parameters and the several theoretical approaches varies according to the case study
Parametric study of lateral loaded piles by computational modeling
Since soils are heterogeneous materials and the survey methods are based on insufficiently representative soil samples, there are several variables involved and less reliability in estimating the load capacity of the structures. So that, it is necessary to keep verifying the validity of stress and displacement method analysis in order to achieve results with more precision. In this sense, the objective of this study was to develop a two-dimensional computational analysis of the axial and transverse (simultaneous) loading effects on isolated, bored and reinforced concrete piles. In addition, different types of soil, piles dimensions, soil stratigraphy, drainage conditions and soil mechanical parameters were considered as variables of this study. Thereby, the axial load capacity of piles was verified by the method of NAVFAC DM 7.2, the settlement by the methods of Poulos & Davis (1980) and Masopust (1994), and the distribution of horizontal forces and displacements by the p-y method, based on the horizontal reaction modulus obtained from the theoretical approaches by Bowles (1997), Vesic (1977), CSN 73 1004, Pochman & Simek (1989) and Matlock & Reese (1956). Regarding to the distribution of lateral stresses and displacements by the p-y method, no interference on results was observed due to change of friction angle, cohesion, coefficient of lateral earth pressure and soil drainage conditions. In addition, it was concluded that the horizontal forces and displacements are more dependent on the diameter than the length of piles.info:eu-repo/semantics/publishedVersio
The Proper Ki-67 Cut-Off in Hormone Responsive Breast Cancer. A Monoinstitutional Analysis with Long-Term Follow-Up
Introduction: Breast cancer is a heterogeneous disease. Our study focuses on a monoinstitutional series of patients affected by Hormone Responsive carcinomas (luminal A and luminal B) and aims to define an optimal Ki-67 cut-off, to correctly stratify these patients into risk classes, using the ImmunoHistoChemical (IHC) surrogates of the Molecular Subtypes, according to the St. Gallen guidelines. Methods: We analyzed 1685 patients. These patients underwent both radical and conservative surgeries with Sentinel Lymph Node Biopsy eventually followed by Axillary Dissection (AD). Furthermore, all the patients underwent adjuvant therapies according to the guidelines. A retrospective univariate analysis was performed and survival curves (Disease-Related Survival, DRS, and Disease-Free Survival, DFS) were carried out according to the following ki-67 risk classes: Low Risk (Ki-67 ≤ 14%); Intermediate Risk (Ki-67 15% ÷ 20%); High Risk (Ki-67 > 20%). Results: 14 yy DRS was 98% in LA and 85% in LB with a ki-67 cut-off of 14% (p=0.037) vs 95% (LA) and 83% (LB) with a ki-67 cut-off of 20% (p=0.003). 14yy DFS was 85% in LA and 72% in LB with a ki-67 cut-off of 14% (p=0.017) vs 83% (LA) and 66% (LB) with a ki-67 cut-off of 20% (p<0.000). Discussion: Our results confirmed that the 20% Ki-67 cut-off is more reliable in differentiating patients at low or high risk of recurrence and death, and stratifying patients eligible for adjuvant chemotherapy. Thus, despite its poor reproducibility, the identification of the most accurate ki-67 index assumes a pivotal relevance in guiding a tailored strategy among patients with this specific profile of breast cancer, as well as the molecular surrogates, in order to avoid harmful overtreatments
Contralateral prophylactic mastectomies. Correlations between primary tumor and histological findings of controlateral breast
Backgound: In Italy in 2015 48,000 new cases of breast carcinomas were diagnosed. Women who are diagnosed with breast cancer have a significant risk of developing contralateral breast cancer during the rest of their lives and this risk is closely associated to the family history, to the onset of breast cancer at a young age and is expressed at about 0.5 to 1% of metachronous tumors per
year. The purpose of this work was to evaluate which and how many neoplastic lesions were seen in the contralateral breast that underwent prophylactic mastectomy and to understand what factors predict the appearance of such lesions.
Methods: 168 bilateral mastectomies were analyzed in patients with an average age of 47 years, carried out from July 2008 to April 2016, at the Breast Unit of the Sant’Andrea Hospital. We considered women of any age suffering from unilateral breast cancer without either clinical or radiological evidence of a malignant lesion in the contralateral breast and negative for mutations of the BRCA1-BRCA2 genes test. Of the 168 bilateral mastectomies 35 patients were excluded from the study because they underwent neoadjuvant chemotherapy, another 35 patients because they were suffering from a bilateral neoplasia and 7 cases because they had mutated BRCA1 or BRCA2 genes. Therefore the remaining 91 patients were included in the study.
Results: Both the histological features of the primary tumor and any lesions found in the contralateral prophylactic breast were analyzed. Histological examination of the main breast showed 59 cases of Invasive Ductal Carcinoma (IDC), 17 cases of Invasive Lobular Carcinoma (ILC), 9 cases of In Situ Ductal Carcinoma (ISDC), 3 microinvasive ductal, 1 invasive tubular carcinoma, 1 in situ lobular and 1 widespread in situ. In the contralateral breast, the definitive histological examination revealed that 47 patients had an occult lesion in the prophylactic contralateral breast; in particular 2 cases of LIN 1, 7 cases of LIN2, 6 cases of lobular carcinoma in situ, 26 between DIN1A/DIN1A-B/DIN1B, 4 cases of carcinoma in situ and 2 cases of Invasive Ductal Carcinoma. The correlation obtained from the observation of the main tumor has shown that in a total of 59 invasive ductal carcinoma 32 have a controlateral occult lesions
and in a total of 17 cases of invasive lobular carcinoma 9 have an occult lesion in the prophylactic breast. Of these lesions, the multicentric relationship is that 50% of invasive ductal and invasive lobular carcinoma of the main breast have a contralateral lesion.
Conclusion: In conclusion we would like to remind, as demonstrated by our follow-up data and as the literature reiterates, that this surgery does not improve patient survival. Certainly patients with unilateral breast cancer have many surgical therapies to be able to deal with not only having a bilateral mastectomy. The end point of this work is try to understand the risk factors of having a contralateral breast lesion to reduce the probability of a metachronous cance
Importance of perforating vessels in nipple-sparing mastectomy. an anatomical description
BACKGROUND: Nipple-sparing mastectomy (NSM), understood as an oncologically valid procedure, is relatively new, and is an evolution of traditional mastectomy, particularly in relation to breast-conserving surgery. The anterior perforating branches are responsible for the cutaneous vascularization of the breast skin, and their preservation is a fundamental step to avoid possible postoperative necrosis. Therefore, evaluating the potential complications of cancer-related reconstructive surgical procedures such as NSM, both the distance of the tumoral lesion from the skin and the surgical incision site should be carefully considered. The preferred site of incision corresponds to the inframammary fold or possibly the periareolar area.
METHODS: We retrospectively reviewed 113 patients who underwent NSM from January 2005 to October 2012 to evaluate skin complications. The anatomical study was performed by magnetic resonance imaging of the breast.
RESULTS: Only one of the 113 women who had undergone a NSM procedure had total necrosis (0.9%) and six patients had partial necrosis (5.8%) of the nipple-areola complex
Nitrogen budget and statistical entropy analysis of the Tiber River catchment, a highly anthropized environment
Modern farming causes a decline in the recycling of the soil's inorganic matter due to losses by leaching, runoff, or infiltration into the groundwater. The Soil System Budget approach was applied to evaluate the net N budget at the catchment and sub-catchment levels of the Tiber River (central Italy) in order to establish the causes for different N budgets among the sub-catchments. Statistical Entropy Analysis (SEA) was used to evaluate the N efficiency of the Tiber River and its sub-catchments, providing information on the dispersion of different N forms in the environment. The total N inputs exceeded the total outputs, showing a low N retention (15.8%) at the catchment level, although some sub-catchments showed higher N retention values. The Utilized Agricultural Area was important in the determination of the N balance, as it was linked to zoo- and agricultural activities, although the Random Forest analysis showed that the importance ranking changed with the land use. The low N retention of the Tiber catchment was due to the soil characteristics (Cambisols and Leptosols), loads from atmospheric deposition, biological fixation, and the livestock industry. The SEA simulations showed a reduction of the N released into the atmosphere and groundwater compartments from 34% to 6% through a reduction of the N loads by 50%
Corrosion resistance evaluation of precipitation hardening stainless steels with nb
Os aços inoxidáveis endurecÃveis por precipitação foram desenvolvidos a partir de 1945, em decorrência das necessidades da indústria aeroespacial em termos da disponibilidade de aços com resistência mecânica e à corrosão, em temperaturas mais elevadas, superiores à s dos aços inoxidáveis tradicionais, aliadas à facilidade de soldagem. Esses aços apresentam microestruturas martensÃticas do tipo substitucional, endurecidas posteriormente por precipitados. Nesse trabalho, foram produzidos dois aços com composições alternativas usando o Nb como formador de precipitados, bem como um aço PH13-8Mo para efeito de comparação, em termos de resistências mecânica e à corrosão. O Aço 1 apresentou resistência à corrosão semelhante à do aço PH13-8Mo e o Aço 2 apresentou resistência mecânica próxima à do aço PH13-8Mo.Precipitate-hardened stainless steel was developed in 1945 as a consequence of the aerospace industry’s need for a high-strength steel that would be resistant to corrosion at high temperatures, and easily welded exceeding the properties of conventional stainless steel. This steel possesses substitutional martensitic microstructures that can afterwards be hardened by precipitation. For this research, two types of steel with alternative compositions were produced by using Nb as a precipitate producer, and PH13-8Mo steel for comparison purposes in terms of mechanical and corrosive resistance. Steel 1 showed corrosive resistance similar to PH13-8Mo and Steel 2 presented mechanical resistance close to that of PH13-8Mo.Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES)CNP
Elaboración de plan de gestión del alcance, tiempo, adquisiciones y ambiental de la construcción del pabellón de ingenierÃa civil de la Universidad de Chota
El presente trabajo busca desarrollar un sistema de gerencia para el proyecto:
Instalación del Servicio Académico de la Carrera Profesional de Contabilidad de
la Universidad Nacional Autónoma de Chota, en comparación con los sistemas de
gerencia utilizados en nuestro medio, a fin de que se adopte un modelo de gestión
de proyectos de acuerdo a los requerimientos del cliente y las caracterÃsticas
especÃficas del proyecto.
Para el caso del proyecto en estudio, se consideró necesario desarrollar la gestión
de las siguientes áreas de conocimiento: Gestión del Alcance, Gestión del Tiempo,
Gestión de las Adquisiciones y gestión del Medio Ambiente.
Finalmente cabe señalar que este estudio busca ser una propuesta guÃa de
aplicación para gerencia de proyectos, basada en los lineamientos del PMI, más
que una regla práctica, y además busca contribuir en el proceso de renovación de
la gerencia de proyectos, en el cual, a partir de las necesidades del cliente, se
establezca un modelo de gestión adecuado, para garantizar el éxito del proyecto en
términos de la satisfacción de todas las partes involucradas.This paper seeks to develop a management system for the project: Installation of
Academic Career Service Accounting, National Autonomous University of Chota,
compared to management systems used in our environment, so that it adopts a
project management model based on customer requirements and specific
characteristics of the project.
For the case study project, it was considered necessary to develop the
management of the following knowledge areas: Scope Management, Time
Management, Procurement Management and Environment Management.
Finally it should be noted that this study is intended as a guide to application
management projects proposed, based on the guidelines of PMI, but a rule of
thumb, and also seeks to contribute to the renewal process of project management,
in which from customer needs, proper management model is established to ensure
the success of the project in terms of the satisfaction of all parties involved.Tesi
Characterization of plasma nitrocarburized layers produced on AISI 316L austenitic stainless steel
A dureza e, conseqüentemente, a resistência ao desgaste dos aços inoxidáveis austenÃticos podem ser acentuadamente aumentadas, sem perdas na resistência à corrosão, com a produção de camadas superficiais pelo tratamento de nitrocementação por plasma. Nesse trabalho, foram nitrocementadas por plasma, na temperatura de 450°C, amostras do aço AISI 316L. As camadas obtidas foram caracterizadas por meio de ensaios micrográficos, de microdureza e de microdesgaste. A camada produzida constituiu-se de duas regiões, sendo a mais externa constituÃda de nitrocarbonetos de cromo e, abaixo dela, verificou-se a presença de austenita expandida, rica em nitrogênio, com dureza próxima a 850HV. A espessura média total da camada foi de, aproximadamente, 40µm. Sua resistência ao desgaste foi muito superior à do substrato.Hardness and consequently wear resistance of austenitic stainless steel can be highly increased, without losing corrosion resistance, by plasma nitrocarburizing surface treatment. In this re-search, an AISI 316L stainless steel was plasma nitrocarburized at 450°C, and the obtained layers were characterized by optical microscopy, microhardness and micro-wear tests. It was verified that the layer is composed of chromium nitrides precipitates and beneath them, a nitrogen rich expanded austenite, with hardness around 850HV. The total average thickness of the layer was about 40µm and presented good uniformity. The wear resistance of the layer was much higher than that of the substrate.Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES)CNP
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