Resistance Spot Welding of Dissimilar Steels: Temperature Curves

Resistance spot welding was used to joint AISI 316L austenitic stainless steel and AISI 1020 low carbon steel. During the welding process, temperature measurements were taken to obtain the temperature curves. Because of the different chemical compositions of the carbon steel and stainless steels, their thermal conductivity values are also different. Electrical resistivity is also an important parameter when carbon steel is spot welded to stainless steel. Differences in the thermal conductivity and in the electrical resistivity of metals lead to an asymmetrical weld nugget in the dissimilar joints. Dissimilar resistance spot welding can be more complex than similar welding due to different thermal cycle experienced with each metal

Experimental Determination of the Convective Coefficient of Heat Transfer Using the Global Capacitance Method

The heat transfer coefficient (h) is an extremely important variable in the evaluation of convective heat transfer, however, its determination is a great challenge due to the various factors that influence it: fluid viscosity, fluid density, specific heat of the fluid, thermal conductivity of the fluid, coefficient of volumetric expansion, fluid velocity. The objective of this work is the experimental determination of the convective heat transfer coefficient by means of the global capacitance method. Three test bodies, two cylindrical bodies and one spherical body were used. These specimens were individually heated in a stove, and heating was monitored by means of a thermocouple and a data logger. The results showed a good concordance between the values of h obtained experimentally and the literature

Photography-based taxonomy is inadequate, unnecessary, and potentially harmful for biological sciences

The question whether taxonomic descriptions naming new animal species without type specimen(s) deposited in collections should be accepted for publication by scientific journals and allowed by the Code has already been discussed in Zootaxa (Dubois & Nemésio 2007; Donegan 2008, 2009; Nemésio 2009a–b; Dubois 2009; Gentile & Snell 2009; Minelli 2009; Cianferoni & Bartolozzi 2016; Amorim et al. 2016). This question was again raised in a letter supported by 35 signatories published in the journal Nature (Pape et al. 2016) on 15 September 2016. On 25 September 2016, the following rebuttal (strictly limited to 300 words as per the editorial rules of Nature) was submitted to Nature, which on 18 October 2016 refused to publish it. As we think this problem is a very important one for zoological taxonomy, this text is published here exactly as submitted to Nature, followed by the list of the 493 taxonomists and collection-based researchers who signed it in the short time span from 20 September to 6 October 2016

Utilização de eritropoetina por pacientes incidentes em hemodiálise no Sistema Único de Saúde, Brasil, 2002-2003 Erythropoietin use by incident hemodialysis patients in the Brazilian Unified National Health System, 2002-2003

Este estudo visa a descrever o perfil demográfico e epidemiológico de pacientes incidentes em hemodiálise, que utilizaram eritropoetina em 2002 e 2003, no Brasil, e identificar fatores associados ao uso desse medicamento. Foram analisados dados demográficos, clínicos e relacionados à unidade de diálise de 32.136 pacientes, identificados por pareamento determinístico-probabilístico de dados do subsistema de autorização de procedimentos de alto custo e do Sistema de Informações sobre Mortalidade. Um modelo de regressão de Poisson foi usado para identificar fatores associados ao uso de eritropoetina. Sexo masculino; idade inferior a 65 anos; nefropatia diabética; fístula arteriovenosa ao iniciar hemodiálise e residir em outras Unidades Federativas diferentes do Mato Grosso foram fatores associados ao uso de eritropoetina. A política de atenção ao doente renal, a alocação de recursos para estados e municípios e o manejo da anemia, segundo o perfil farmacoterapêutico dos pacientes, devem ser revistos, a fim de reduzir as iniquidades observadas na utilização da eritropoetina.<br>This study aimed to describe the demographic and epidemiological profile of Brazilian patients entering hemodialysis from 2002 to 2003 and identify predictors of erythropoietin use. The study analyzed demographic and clinical characteristics and dialysis facility-related variables from 32,136 patients identified by deterministic-probabilistic matching in the database of authorizations for high-cost procedures and the Mortality Information System. Poisson regression was used to identify predictors of erythropoietin use. Male gender, age < 65 years, diabetic renal failure, arteriovenous fistula at the beginning of hemodialysis, and living in States of Brazil other than Mato Grosso were predictors of erythropoietin use. The policy of care for chronic kidney disease, resource allocation for States and municipalities, and anemia management according to the patient's drug therapy profile need to be revised in order to reduce observed inequities in erythropoietin use

The Omicron Lineages BA.1 and BA.2 (<i>Betacoronavirus</i> SARS-CoV-2) Have Repeatedly Entered Brazil through a Single Dispersal Hub

Brazil currently ranks second in absolute deaths by COVID-19, even though most of its population has completed the vaccination protocol. With the introduction of Omicron in late 2021, the number of COVID-19 cases soared once again in the country. We investigated in this work how lineages BA.1 and BA.2 entered and spread in the country by sequencing 2173 new SARS-CoV-2 genomes collected between October 2021 and April 2022 and analyzing them in addition to more than 18,000 publicly available sequences with phylodynamic methods. We registered that Omicron was present in Brazil as early as 16 November 2021 and by January 2022 was already more than 99% of samples. More importantly, we detected that Omicron has been mostly imported through the state of São Paulo, which in turn dispersed the lineages to other states and regions of Brazil. This knowledge can be used to implement more efficient non-pharmaceutical interventions against the introduction of new SARS-CoV variants focused on surveillance of airports and ground transportation