Structural and magnetic characterization of the intermartensitic phase transition in NiMnSn Heusler alloy ribbons

"Phase transitions and structural and magnetic properties of rapidly solidified Ni50Mn38Sn12 alloy ribbons have been studied. Ribbon samples crystallize as a single-phase, ten-layered modulated (10M) monoclinic martensite with a columnar-grain microstructure and a magnetic transition temperature of 308 K. By decreasing the temperature, martensite undergoes an intermartensitic phase transition around 195 K. Above room temperature, the high temperature martensite transforms into austenite. Below 100 K, magnetization hysteresis loops shift along the negative H-axis direction, confirming the occurrence of an exchange bias effect. On heating, the thermal dependence of the coercive field H-C shows a continuous increase, reaching a maximum value of 1017 Oe around 50 K. Above this temperature, H-C declines to zero around 195 K. But above this temperature, it increases again up to 20 Oe falling to zero close to 308 K. The coercivity values measured in both temperature intervals suggest a significant difference in the magnetocrystalline anisotropy of the two martensite phases.

Establecimiento de ensayos para modelación de fríjol en el TeSAC del Cauca, Colombia

Las intervenciones y monitoreo de sistemas de producción de fríjol del TeSAC en el departamento del Cauca, Colombia, en comunidades intervenidas con Servicios Participativos de Clima para la Agricultura (PICSA) dan luces sobre las decisiones de manejo derivadas del análisis de la variabilidad climática histórica y pronosticada en el territorio. En este contexto, se llevó a cabo un ensayo de fríjol con las variedades Calima, SAB686 y la variedad bioforticada BIO101 entre noviembre de 2019 y febrero de 2020 en la finca Altobonito, en el departamento de Cauca. Se evaluó información sobre crecimiento y desarrollo del cultivo necesaria para la ejecución del modelo de cultivo CROPGRO-Dry Bean frente a las condiciones ambientales y de manejo agronómico dadas. Los resultados obtenidos muestran que el crecimiento y desarrollo de las variedades de frijol en el ensayo tuvieron una respuesta satisfactoria. Los resultados del modelo CROPGRO-Dry para la variedad Calima presentó un mejor ajuste para las variables de peso seco de la planta CWAD (kg/ha); peso seco de hojas, LWAD kg/ha); peso seco de vainas, PWAD (kg/ha) y para el rendimiento GWAD (kg/ha). Las variables: índice de área foliar LAID y peso de los tallos SWAD no presentaron un buen ajuste. Para la variedad SAB686 las variables que presentaron un buen ajuste fueron peso seco de la planta, CWAD (kg/ha), peso seco de vainas, PWAD (kg/ha), peso seco de hojas, LWAD kg/ha) y SWAD, peso seco de tallos, SWAD (kg/ha) presentaron un buen ajuste

Caloric effects induced by magnetic and mechanical fields in a Ni50Mn25-xGa25Cox magnetic shape memory alloy

"We have studied the elastocaloric effect in a Co-doped Ni-Mn-Ga magnetic Heusler shape memory alloy in the vicinity of its martensitic transition. Measurements of the length change as a function of temperature have been carried out across the transition under applied compression stresses and magnetic fields. The isothermal stress-induced entropy changes have been computed from the experimental data. Results evidence a significant elastocaloric effect associated with the large entropy change of the structural phase transition. The alloy also exhibits a magnetocaloric effect at low applied magnetic fields. It is shown that application of a magnetic field below 1 T increases the estimated elastocaloric relative cooling power by about 20%. A comparison of elasto-and magnetocaloric properties indicates that a similar relative cooling power is reached under application of 10 MPa or 0.8 T.

A circular economy framework for seafood waste valorisation to meet challenges and opportunities for intensive production and sustainability

There is a growing concern among societies and consumers over food security and the sustainability of food production systems. For seafood, it has been highly advocated as a healthy food source and its sustainability credentials. However, the increasing global demand for seafood and the need to supply the quantities are creating sustainability issues, e.g., the importation of plant and marine proteins for aquafeed production. Consequently, there is a necessary need to analyse the supply chain and life cycle of these systems to determine their sustainability merits and how to enhance them. The circular economy (CE) aims to reduce processing by-product underutilisation, increase the rate of reuse, and reduce pressure on natural resources and systems. For seafood, there are large quantities of biomass that are being lost through bycatch/discards, waste from aquaculture (e.g., sludge and wastewater), and by-products generated through processing (e.g., trimmings and offal). These can all be valorised for the generation of feeds, value-added products, or further food production. This review will focus on seafood by-products generated during the processing into consumer products, and the current methods that could be used to manage or treat these waste streams. The review presents a stepwise framework that outlines valorisation opportunities for seafood by-products. This framework can enable producers, operators, regulators, and investors to integrate with the principles of the CE with the consideration of achieving economic viability. The challenges of seafood loss due to climate change and emerging recycling strategies will also need to be considered and integrated into the valorisation pathways. Communication, education, and engagement with stakeholders are key to transitioning to a circular economy. Where increase awareness and acceptance will create drivers and demand for seafood by-product valorisation. Overall, the impact of such a circular production system will potentially lead to higher production efficiency, reduce demand for natural resources, and greater seafood production. All of which addresses many of the United Nation's Sustainable Development Goals by contributing towards future food security and sustainability.This work was supported by the EAPA_576/2018 NEPTUNUS project. The authors would like to acknowledge the financial support of Interreg Atlantic Area. A.H.L Wan was co-funded under the HYDROfish project (2019–2022) which was funded under the Disruptive Technologies Innovation Fund (DTIF), established under Project Ireland 2040, run by the Department of Enterprise Trade and Employment with administrative support from Enterprise Ireland. His opinions expressed are his own. The authors would also like to thank Matt Bell for his editorial assistance

Association between physical fitness parameters and health related quality of life in Chilean community-dwelling older adults

Background: There is no conclusive evidence about the association between physical fitness (PF) and health related quality of life (HRQOL) in older adults. Aim: To seek for an association between PF and HRQOL in non-disabled community-dwelling Chilean older adults. Material and Methods: One hundred and sixteen subjects participated in the study. PF was assessed using the Senior Fitness Test (SFT) and hand grip strength (HGS). HRQOL was assessed using eight dimensions provided by the SF-12v2 questionnaire. Binary multivariate logistic regression models were carried out considering the potential influence of confounder variables. Results: Non-adjusted models, indicated that subjects with better performance in arm curl test (ACT) were more likely to score higher on vitality dimension (OR > 1) and those with higher HGS were more likely to score higher on physical functioning, bodily pain, vitality and mental health (OR > 1). The adjusted models consistently showed that ACT and HGS predicted a favorable perception of vitality and mental health dimensions respectively (OR > 1). Conclusions: HGS and ACT have a predictive value for certain dimensions of HRQOL.Trabajo financiado por el Fondo Nacional de Investigación en Salud (FONIS), código de proyecto SA12I2229

Treatment with tocilizumab or corticosteroids for COVID-19 patients with hyperinflammatory state: a multicentre cohort study (SAM-COVID-19)

Objectives: The objective of this study was to estimate the association between tocilizumab or corticosteroids and the risk of intubation or death in patients with coronavirus disease 19 (COVID-19) with a hyperinflammatory state according to clinical and laboratory parameters. Methods: A cohort study was performed in 60 Spanish hospitals including 778 patients with COVID-19 and clinical and laboratory data indicative of a hyperinflammatory state. Treatment was mainly with tocilizumab, an intermediate-high dose of corticosteroids (IHDC), a pulse dose of corticosteroids (PDC), combination therapy, or no treatment. Primary outcome was intubation or death; follow-up was 21 days. Propensity score-adjusted estimations using Cox regression (logistic regression if needed) were calculated. Propensity scores were used as confounders, matching variables and for the inverse probability of treatment weights (IPTWs). Results: In all, 88, 117, 78 and 151 patients treated with tocilizumab, IHDC, PDC, and combination therapy, respectively, were compared with 344 untreated patients. The primary endpoint occurred in 10 (11.4%), 27 (23.1%), 12 (15.4%), 40 (25.6%) and 69 (21.1%), respectively. The IPTW-based hazard ratios (odds ratio for combination therapy) for the primary endpoint were 0.32 (95%CI 0.22-0.47; p < 0.001) for tocilizumab, 0.82 (0.71-1.30; p 0.82) for IHDC, 0.61 (0.43-0.86; p 0.006) for PDC, and 1.17 (0.86-1.58; p 0.30) for combination therapy. Other applications of the propensity score provided similar results, but were not significant for PDC. Tocilizumab was also associated with lower hazard of death alone in IPTW analysis (0.07; 0.02-0.17; p < 0.001). Conclusions: Tocilizumab might be useful in COVID-19 patients with a hyperinflammatory state and should be prioritized for randomized trials in this situatio

On the kinetic arrest of martensitic transformation in Ni-Mn-In melt-spun ribbons

"Kinetic arrest (KA) of martensitic transformation (MT) has been observed in as-solidified Ni52.2Mn34.3In13.5 melt-spun ribbons; a characterization by dc magnetization measurements was carried out. These alloy ribbons transform martensitically from a single austenitic (AST) parent phase with B2-type crystal structure. For an applied magnetic field U0H of 1 T and up to 9 T, a moderate but progressive KA of the MT is observed. The metastability of the non-equilibrium field-cooled glassy state was characterized by introducing thermal and magnetic field fluctuations. It was found that the total magnetization difference (??) between the zero field-cooling (ZFC) and field-cooling (FC) pathways of the temperature dependence of magnetization ??(T) shows irreversible and reversible components; the former decreases as the temperature decreases. After a short thermal annealing of 10 min at 1073 K AST shows a highly ordered L21-type crystal structure and the kinetic arrest of martensitic transformation is no longer observed suggesting a connection between the crystal structure order of austenite and the appearance of the kinetic arrest phenomenon.

Martensitic transformation of Cu-based shape-memory alloys: Elastic anisotropy and entropy change

We have studied the martensitic transformation in a family of Cu-Al-Be crystals: We have measured the entropy change of the transition using a high-sensitivity calorimeter, and the elastic anisotropy of the high-temperature phase as a function of temperature by an ultrasonic method. Both entropy change and elastic anisotropy at the transition temperature are shown to be independent of the alloy composition. On the other hand, the vibrational entropy change and the elastic anisotropy have been theoreticallay related by an expression containing the fraction of low-energy modes. This relation has been specified for two different situations: (i) The region of soft modes is limited to wave vectors very close to the [ξξ0] direction in the reciprocal space and (ii) the region of soft modes is allowed to spread up to wave vectors with directions differing substantially from [ξξ0]. Our experimental results and other results for other families of Cu-based alloys are consistent with the two relations, suggesting a small (or at least composition independent) electronic contribution to the total entropy change

Materiales emisores de luz blanca y método de preparación de los mismos

"The instant invention is related with new perimidine derivatives synthesized via direct condensation between naphthalene-1,8-diamine and itaconic or citraconic anhydrides at low temperature. The targeting itaco-perinone (IP) molecule formed via double low temperature cyclization has fluorescence properties emitting white light intensively. Besides, 9-methylene-8H-pyrrolo[1,2-a]perimidin-10(9H)-one is copolymerizable with several kind of organic monomer compounds via free radical mechanism maintaining the ability to emit white light even within the polymer film.""La presente invención se relaciona con nuevos derivados de perimidina sintetizados por medio de condensación directa entre naftalen-1, 8-diamina y anhídridos itacónicos o citracónicos a baja temperatura. La molécula blanco itacoperinona (IP) formada por doble vía de ciclación doble a baja temperatura tiene propiedades de fluorescencia emitiendo luz blanca de forma intensa. Además, el 9-metilen-8H-pirrolo[1,2-a]perimidin-10(9H)-on a es copolimerizable con diversos tipos de mónomeros orgánicos por medio del mecanismo de radicales libres manteniendo su habilidad de emitir luz blanca aún de una película polimérica"

Characterization of the kinetic arrest of martensitic transformation in Ni45Co5Mn36.8In13.2 melt-spun ribbons

"The kinetic arrest (KA) of martensitic transformation (MT) observed in Ni45Co5Mn36.8In13.2 melt-spun ribbons has been studied. These alloy ribbons show an ordered columnar-like grain microstructure with the longer grain axis growing perpendicular to ribbon plane and transform martensitically from a single austenitic (AST) parent phase with the L21-type crystal structure to a monoclinic incommensurate 6 M modulated martensite (MST). Results show that the volume fraction of austenite frozen into the martensitic matrix is proportional to the applied magnetic field. A fully arrest of the structural transition is found for a magnetic field of 7 T. The metastable character of the non-equilibrium field-cooled glassy state was characterized by introducing thermal and magnetic field fluctuations or measuring the relaxation of magnetization. The relaxation of magnetization from a field-cooled kinetically arrested state at 5 and 7 T follows the Kohlrausch–Williams–Watts (KWW) stretched exponential function with a ? exponent around 0.95 indicating the weak metastable nature of the system under the strong magnetic fields. The relationship between the occurrence of exchange bias and the frozen fraction of AST into the MST matrix was studied.