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The present study investigates the effect of welding heat input on the corrosion resistance of duplex stainless steel (DSS) overlays, with particular focus on applications in pressure vessels and clad plates. ER2209 filler metal was deposited onto SA-516 Gr. 70 carbon steel using GMAW, both manually and mechanized, with varying heat inputs. Microstructural characterization included ferrite-content measurement, macrographic analysis, and pitting-corrosion testing according to ASTM G48 Method A. The results indicate that increasing the heat input from 548 J mm−1 to 2319 J mm−1 significantly reduced the ferrite content from 49% to 25%, leading to a corresponding increase in weight loss from 0.55% to 2.5%. Mechanized welding exhibited better arc stability and more consistent phase distribution compared to the manual process. Although we did not detect brittle phases or intermetallic precipitates due to strict interpass temperature control, the microstructural imbalance induced by high-heat-input directly compromised the corrosion resistance. These findings advance understanding of the optimized welding parameters required to ensure the integrity of DSS coatings in aggressive environments.

Super-duplex stainless steel (SDSS) shows high mechanical and corrosion resistance because of the balanced structure of austenite and ferrite. However, maintaining this phase ratio after welding is a challenge. The use of austenite stabilizing components is recommended to balance the microstructure. The addition of alloying elements presents a challenge because of the characteristics of Nd:YAG pulsed laser welding. An approach, which has proven to be effective, is to use metal electroplating to prepare the surfaces of the mechanical SDSS components that will be welded, therefore promoting the phase balance in the fusion zone. While the effects of metals such as nickel as an austenite stabilizer are well recognized, cobalt’s effects require more research. The present work investigated the influence of the use of cobalt addition in the joining process by preliminary electroplating on UNS S32750 SDSS Nd: YAG pulsed laser welding, specifically regarding microstructure and microhardness. Three conditions were investigated, changing the thickness of the deposited cobalt layer. The addition of cobalt modified the morphology and increased the volume fraction of austenite. An austenite volume fraction of around 48% was obtained using a 35 μm thick cobalt coating. The microhardness was affected by austenite/ferrite proportions. The microhardness dropped from about 375 HV to 345 HV as the cobalt layer’s thickness rose, being similar to that of the base metal. The effect of cobalt as an austenite stabilizer was observed, and the cobalt electroplating technique was effective to correct the phase balance on UNS S32750 laser welding.

The pathogenic role of inflammation and oxidative stress in chronic kidney disease (CKD) is well known. Anti-inflammatories and antioxidant drugs has demonstrated significant renoprotection in experimental nephropathies. Moreover, the inclusion of natural antioxidants derived from food and herbal extracts (such as polyphenols, curcumin and lycopene) as an adjuvant therapy for slowing CKD progression has been largely tested. Brazilian propolis is a honeybee product, whose anti-inflammatory, antimicrobial and antioxidant effects have been widely shown in models of sepsis, cancer, skin irritation and liver fibrosis. Furthermore, previous studies demonstrated that this compound promotes vasodilation and reduces hypertension. However, potential renoprotective effects of propolis in CKD have never been investigated. The aim of this study was to evaluate the effects of a subtype of Brazilian propolis, the Red Propolis (RP), in the 5/6 renal ablation model (Nx). Adult male Wistar rats underwent Nx and were divided into untreated (Nx) and RP-treated (Nx+RP) groups, after 30 days of surgery; when rats already exhibited marked hypertension and proteinuria. Animals were observed for 90 days from the surgery day, when Nx+RP group showed significant reduction of hypertension, proteinuria, serum creatinine retention, glomerulosclerosis, renal macrophage infiltration and oxidative stress, compared to age-matched untreated Nx rats, which worsened progressively over time. In conclusion, RP treatment attenuated hypertension and structural renal damage in Nx model. Reduction of renal inflammation and oxidative stress could be a plausible mechanism to explain this renoprotection.

Super duplex stainless steels (SDSS) are materials known for their exceptional mechanical strength and high resistance to corrosion due to their dual- phase microstructure consisting of ferrite and austenite in roughly equal proportions. However, the Gas Tungsten Arc Welding (GTAW) process used to join SDSS often causes microstructural imbalances, mainly ferritic structures, or the formation of harmful intermetallic phases, which can weaken the material’ s desirable properties. This study examines the effect of substrate preheating on the microstructure, mechanical properties, and corrosion resistance of UNS S32750 SDSS welds produced by GTAW. Preheating the substrate was considered as a strategy to improve phase balance in the fusion zone by extending the time within the ferrite- to- austenite transformation temperature range, thus slowing the cooling rates. Four conditions were tested: welding at room temperature (RT) and preheating to 100 °C (T100), 200 °C (T200), and 300 °C (T300). Welding parameters remained constant. The fusion zone microstructure was analyzed using metallographic techniques, while mechanical properties were evaluated through microhardness tests. Corrosion resistance was assessed with potential dynamic polarization in a 3.5% NaCl solution. The results showed significant improvements in microstructural balance with higher preheating temperatures. The austenite volume fraction in the fusion zone increased from about 16% at RT to 42% at T 300. Mechanical testing indicated a decrease in microhardness from 341 HV at RT to 314 HV at T 300, reflecting the increased austenite content and its associated toughness. Corrosion tests demonstrated enhanced resistance under preheated conditions, with T 300 exhibiting the highest corrosion potential and the lowest corrosion current, nearing the performance of the base metal. These findings suggest that preheating is a practical, cost- effective method for optimizing the GTAW process for SDSS, eliminating the need for expensive filler materials and stabilizing the microstructure elements.

Among the many challenges robots encounter in the mining industry, exploring confined environments receives significant attention. This work tackles problems associated with robot communication in hazardous and confined environments, where its cluttered and extensive nature frequently precludes traditional cable-based and wireless solutions. Our methods resort to off-the-shelf long-range radio frequencies to profile the signal propagation behaviour over the geometrical map to assist navigation algorithms that seek to preserve the connection. We consider mathematical models to predict signal power behaviour and serve as input to path planning. We also propose a semi-autonomous leader-follower scheme, with signal repeater units forming a mobile wireless network to enable inspection in hard-to-reach locations. Finally, we present a multi-robot connection-aware system, combining path planning based on radio signal power with multiple robot navigation. Results show the applicability of the proposed solutions, generating single and multi-robot paths for optimal signal reception based on power estimation, thus enabling operations in remote and isolated areas with no line-of-sight between the command base and the robotic inspection device. Experiments conducted in long corridors and in a representative mining environment using the EspeleoRobô and Pioneer platforms demonstrate significant improvements over the traditional communication methods for robotic operation regarding communication quality and inspection range limits.

Background Leprosy is a chronic infectious disease caused by Mycobacterium leprae , predominantly affecting the peripheral nerves, resulting in sensory and motor deficits in the feet. Foot ulcers and imbalances are frequent manifestations in leprosy, often correlating with diminished sensitivity. While clinical scales and monofilament esthesiometers are conventionally utilized to evaluate foot sensitivity and balance in these patients, their discriminatory power is limited and their effectiveness is greatly dependent on the examiner’s proficiency. In contrast, baropodometry and posturography offer a more comprehensive evaluation, aiming to preempt potential damage events. This study aimed was to assess the correlation between baropodometry and force plate measurements in leprosy patients and control participants, to improve the prevention and treatment of foot ulcers and complications associated with leprosy. Methodology This cross-sectional study was conducted during 2022 and enrolled 39 participants (22 patients with multibacillary leprosy and 17 non-leprosy controls). Demographic data were collected, and a monofilament esthesiometer was used to assess sensory deficits. In addition, physical examinations and balance and plantar pressure tests were conducted. The Student’s t-test was used to compare mean and maximum plantar pressures between groups. For most COP variables, a Mann-Whitney Wilcoxon test was used, except for AP amplitude which was analyzed with the Student’s t-test due to its normal distribution. The relationship between foot pressure and balance control was assessed using Spearman’s correlation, focusing on areas with significant pressure differences between groups. Principal findings Leprosy patients showed increased pressure in forefoot areas (T1, M1, T2-T5, and M2) and decreased pressure in hindfoot regions (MH and LH) compared to controls. These patients also displayed higher AP and ML amplitudes, suggesting poorer COP control. Correlation analyses between the two groups revealed that foot plantar pressures significantly impact balance control. Specifically, increased T1 region pressures correlated with greater sway in balance tasks, while decreased MH region pressures were linked to reduced COP control. Conclusions/significance The findings suggest a joint disturbance of plantar pressure distribution and static balance control in leprosy patients. These alterations may increase the risk of tissue injuries, including calluses and deformities, as well as falls.

Obtaining a balanced microstructure in the fusion zone on a super duplex stainless steel (SDSS) weld is a challenge. The present work reports the use of the Watts bath to correct the phase balance on laser-welded SDSS. Three different Watts bath times were used, and the microstructure of the weld bead was evaluated. The Watts bath was efficient to correct the undesirable unbalanced microstructure resulting from SDSS laser welding as the austenite percentage increased.

Duplex stainless steels (DSSs), a particular category of stainless steels, are employed in all kinds of industrial applications where excellent corrosion resistance and high strength are necessary. These good properties are provided by their biphasic microstructure, consisting of ferrite and austenite in almost equal volume fractions of phases. In the present work, Nd: YAG pulsed laser dissimilar welding of UNS S32750 super duplex stainless steel (SDSS) with 316L austenitic stainless steel (ASS), with different heat inputs, was investigated. The results showed that the fusion zone microstructure observed consisted of a ferrite matrix with grain boundary austenite (GBA), Widmanstätten austenite (WA) and intragranular austenite (IA), with the same proportion of ferrite and austenite phases. Changes in the heat input (between 45, 90 and 120 J/mm) did not significantly affect the ferrite/austenite phase balance and the microhardness in the fusion zone.

ABSTRACT Objectives: to evaluate software technical quality for collecting data from patients under palliative care. Methods: this is methodological technology evaluation research, according to the technical standard International Organization for Standardization/International Electrotechnical Commission 25040-2011, developed from August 2021 to August 2023. Eight nurses and eight information technology professionals participated as judges, who evaluated six quality characteristics and 23 subcharacteristics. Items that reached a percentage of agreement greater than 70% were considered suitable. Results: the characteristics evaluated by nurses/information technology professionals received the following percentages of agreement, respectively: functional suitability (94%-84%); reliability (100-70%); usability (89.9-66.8%); performance efficiency (95.8%-86.1%); compatibility (95.8-79.6%); and safety (96%-83.4%). Conclusions: the software was considered suitable in quality evaluation to offer support to nurses in collecting patient data under palliative care, with the potential to operationalize the first Nursing Process stage. RESUMEN Objetivos: evaluar la calidad técnica del software para la recolección de datos de pacientes en cuidados paliativos. Métodos: se trata de una investigación metodológica de evaluación de tecnología, según la norma técnica International Organization for Standardization/International Electrotechnical Comission 25040-2011, desarrollada de agosto de 2021 a agosto de 2023. Participaron como jueces ocho enfermeros y ocho profesionales de tecnologías de la información, quienes evaluaron seis características de calidad y 23 subcaracterísticas. Se consideraron adecuados los ítems que alcanzaron un porcentaje de acuerdo superior al 70%. Resultados: las características evaluadas por enfermeros/profesionales de tecnologías de la información recibieron los siguientes porcentajes de acuerdo, respectivamente: adecuación funcional (94%-84%); confiabilidad (100-70%); usabilidad (89,9-66,8%); eficiencia del desempeño (95,8%-86,1%); compatibilidad (95,8-79,6%); y seguridad (96%-83,4%). Conclusiones: el software fue considerado adecuado en la evaluación de calidad para ofrecer apoyo a los enfermeros en la recolección de datos de los pacientes en cuidados paliativos, con potencial para operacionalizar la primera etapa del Proceso de Enfermería. RESUMO Objetivos: avaliar a qualidade técnica de software para coleta de dados de pacientes sob cuidados paliativos. Métodos: trata-se de pesquisa metodológica de avaliação de tecnologia, conforme norma técnica International Organization for Standardization/International Electrotechnical Comission 25040-2011, desenvolvida de agosto de 2021 a agosto de 2023. Participaram oito enfermeiros e oito profissionais de tecnologia da informação como juízes, os quais avaliaram seis características e 23 subcaracterísticas de qualidade. Consideraram-se adequados os itens que atingiram porcentual de concordância superior a 70%. Resultados: as características avaliadas pelos enfermeiros/profissionais de tecnologia da informação receberam os seguintes porcentuais de concordância, respectivamente: adequação funcional (94%-84%); confiabilidade (100-70%); usabilidade (89,9-66,8%); eficiência de desempenho (95,8%-86,1%); compatibilidade (95,8-79,6%); e segurança (96%-83,4%). Conclusões: o software foi considerado adequado na avaliação de qualidade para oferecer suporte ao enfermeiro na coleta de dados do paciente em cuidados paliativos, com potencial para operacionalizar a primeira etapa do Processo de Enfermagem.

Welding duplex stainless steels with Nd:YAG pulsed laser welding results in an unbalanced microstructure. The present article reports the effects of nickel addition on the microstructure of UNS S32750 duplex stainless steel welded with an Nd:YAG pulsed laser. Two conditions were used: autogenous welding and welding with the addition of nickel. The addition of nickel resulted in equal proportions of austenite and ferrite in the weld bead, affecting the microstructure.