Spatial Interactions in Hedonic Pricing Models:The Urban Housing Market of Aveiro, Portugal

Spatial heterogeneity, spatial dependence and spatial scale constitute key features of spatial analysis of housing markets. However, the common practice of modelling spatial dependence as being generated by spatial interactions through a known spatial weights matrix is often not satisfactory. While existing estimators of spatial weights matrices are based on repeat sales or panel data, this paper takes this approach to a cross-section setting. Specifically, based on an a priori definition of housing submarkets and the assumption of a multifactor model, we develop maximum likelihood methodology to estimate hedonic models that facilitate understanding of both spatial heterogeneity and spatial interactions. The methodology, based on statistical orthogonal factor analysis, is applied to the urban housing market of Aveiro, Portugal at two different spatial scales

Effect of the temperature on the structure and stability of Fe - 18 Cr - (0 to 60) Ni alloys

The material studied consists of a series of alloys with a basic composition (weight %): 18Cr - 0.01 C - 0.2 Si - 0.4 Mn, and levels of nickel varying from zero to 60%. Alloys in the annealed condition and after deformation at room temperature, 350 and 700°C to simulate the high temperatures achieved during machining were observed by optical microscopy. Equilibrium diagrams were generated by computational thermodynamics (Thermocalc) to predict the behavior of these alloys in a wide range of temperatures. The theoretical thermodynamic equilibrium conditions of the system were compared to the observed microstructures, indicating that the CFC phase in alloys with nickel content between 10% and 30% is, in fact, in a metastable condition at room temperature. Martensitic transformation induced by cold work in the alloy with 10% Ni was observed, validating the computer calculations.O material estudado consiste de uma série de ligas com composição base (% em peso) de 18Cr - 0,01C - 0,2Si - 0,4Mn e teores de níquel variando de zero a 60%. Analisou-se a microestrutura por microscopia ótica das ligas no estado recozido e após deformação à temperatura ambiente, 350 e 700ºC, de modo a simular as altas temperaturas alcançadas na usinagem dessas ligas. Foram também gerados diagramas de equilíbrio das ligas por termodinâmica computacional (Thermocalc) para se prever o comportamento dessas ligas em uma larga faixa de temperaturas. As condições teóricas de equilíbrio termodinâmico do sistema foram comparadas às microestruturas observadas, indicando que a fase CFC nas ligas com teor de níquel entre 10% e 30% em peso está, na realidade, em uma condição metaestável à temperatura ambiente. Foi observada transformação martensítica induzida por trabalho a frio na liga com 10%Ni, validando os cálculos computacionais.455

Efeitos da adição de níquel em ligas ferro-cromo. Parte I: propriedades mecânicas

The aim of this work was to study the influence of Ni additions on the mechanical properties of Fe-Cr alloys. For this purpose, alloys were prepared with an 18%Cr-0.01%C-0.2%Si-0.4%Mn base composition and variable Ni content (0, 10, 20, 40 and 60 weight %). The alloys were characterized by X-Ray diffraction and thermal analyses. Their hardness was determined before and after cold deformation. Tension tests were carried out at room temperature and 350ºC to verify the effect of temperature on the mechanical behavior of the alloys. The mechanical characterization aim was to use these figures to correlate mechanical properties and machinability (results originating from a parallel study).O objetivo desse trabalho é estudar a influência de adições de níquel sobre as propriedades mecânicas de ligas Fe-Cr. Para atender a esse propósito, foram preparadas diversas ligas com a composição básica 18%Cr - 0,01%C - 0,2%Si - 0,4%Mn, variando-se o teor de níquel (0, 10, 20, 40 e 60 % em peso). A caracterização das ligas foi feita por difração de raios X e análise térmica. Foi determinada a dureza das ligas no estado como recebido e após a imposição de deformação a frio. Foram realizados ensaios de tração à temperatura ambiente e a 350ºC, para verificar o efeito da temperatura sobre o comportamento mecânico das mesmas. O objetivo da caracterização mecânica das ligas é o de associar as propriedades mecânicas com as propriedades de usinabilidade, obtidas em estudo que está sendo desenvolvido em paralelo.149154Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Effect of temperature and nickel content on the mechanical properties and their correlation with the machinability of Fe-18Cr-Ni alloys

Tensile tests were carried out at room temperature in Fe-18% Cr alloys, with nickel content varying between zero and 60%, and the properties obtained were correlated with the results of machinability previously obtained by the group. The alloys were also tested at 350 and 700°C in order to obtain these properties in the range of temperature compatible with the machining process. The ferritic alloy presented lower elongation and UTS (ultimate tensile strength) than austenitic alloys at room temperature and 350°C, which explains why, in the machining process, the ferritic alloy shows much greater tool life if compared to austenitic alloys (100 against 20 to 50 minutes, respectively). In the test at 350°C, the temperature reached during machining, the increase in nickel content increased the UTS of austenitic alloys, hampering the machining, and also elevated the ductility (elongation) that produces a higher volume of material adhered on the tool. This higher adhesion capacity, allied to a higher mechanical strength, explains the increase of tool wear as a function of increasing nickel content in the alloy with a consequent reduction in the life of the tool.Foram realizados ensaios de tração na temperatura ambiente em ligas Fe-18%Cr, com teor de níquel variando entre zero e 60% e correlacionaram-se as propriedades obtidas com os resultados de usinabilidade obtidos anteriormente pelo grupo. As ligas foram ensaiadas, também, a 350 e 700ºC, de modo a determinar suas propriedades, na faixa de temperatura alcançada, no local da usinagem. A liga ferrítica apresentou alongamento e limite de resistência menores que as ligas austeníticas, tanto à temperatura ambiente, como a 350°C, o que explica porque, na usinagem dessas ligas, a vida da ferramenta foi muito maior que nas ligas austeníticas (100 contra 20 a 50 minutos, respectivamente). No ensaio a 350ºC, temperatura atingida pela peça na região de usinagem, o aumento do teor de níquel elevou, tanto o limite de resistência das ligas austeníticas, o que dificulta a usinagem, como, também, elevou a ductilidade (alongamento), facilitando a adesão da liga sobre a ferramenta de corte e exigindo maior esforço na usinagem, com conseqüente redução da vida da ferramenta.18519

Canagliflozin and renal outcomes in type 2 diabetes and nephropathy

BACKGROUND Type 2 diabetes mellitus is the leading cause of kidney failure worldwide, but few effective long-term treatments are available. In cardiovascular trials of inhibitors of sodium–glucose cotransporter 2 (SGLT2), exploratory results have suggested that such drugs may improve renal outcomes in patients with type 2 diabetes. METHODS In this double-blind, randomized trial, we assigned patients with type 2 diabetes and albuminuric chronic kidney disease to receive canagliflozin, an oral SGLT2 inhibitor, at a dose of 100 mg daily or placebo. All the patients had an estimated glomerular filtration rate (GFR) of 30 to <90 ml per minute per 1.73 m2 of body-surface area and albuminuria (ratio of albumin [mg] to creatinine [g], >300 to 5000) and were treated with renin–angiotensin system blockade. The primary outcome was a composite of end-stage kidney disease (dialysis, transplantation, or a sustained estimated GFR of <15 ml per minute per 1.73 m2), a doubling of the serum creatinine level, or death from renal or cardiovascular causes. Prespecified secondary outcomes were tested hierarchically. RESULTS The trial was stopped early after a planned interim analysis on the recommendation of the data and safety monitoring committee. At that time, 4401 patients had undergone randomization, with a median follow-up of 2.62 years. The relative risk of the primary outcome was 30% lower in the canagliflozin group than in the placebo group, with event rates of 43.2 and 61.2 per 1000 patient-years, respectively (hazard ratio, 0.70; 95% confidence interval [CI], 0.59 to 0.82; P=0.00001). The relative risk of the renal-specific composite of end-stage kidney disease, a doubling of the creatinine level, or death from renal causes was lower by 34% (hazard ratio, 0.66; 95% CI, 0.53 to 0.81; P<0.001), and the relative risk of end-stage kidney disease was lower by 32% (hazard ratio, 0.68; 95% CI, 0.54 to 0.86; P=0.002). The canagliflozin group also had a lower risk of cardiovascular death, myocardial infarction, or stroke (hazard ratio, 0.80; 95% CI, 0.67 to 0.95; P=0.01) and hospitalization for heart failure (hazard ratio, 0.61; 95% CI, 0.47 to 0.80; P<0.001). There were no significant differences in rates of amputation or fracture. CONCLUSIONS In patients with type 2 diabetes and kidney disease, the risk of kidney failure and cardiovascular events was lower in the canagliflozin group than in the placebo group at a median follow-up of 2.62 years