The Two-Spectra Inverse Problem for Semi-Infinite Jacobi Matrices in The Limit-Circle Case

We present a technique for reconstructing a semi-infinite Jacobi operator in the limit circle case from the spectra of two different self-adjoint extensions. Moreover, we give necessary and sufficient conditions for two real sequences to be the spectra of two different self-adjoint extensions of a Jacobi operator in the limit circle case.Comment: 26 pages. Changes in the presentation of some result

The effect of home storage conditions and packaging materials on the quality of frozen green beans

Home storage is the final step of the frozen foods distribution chain, and little is known on how it affects the products quality. The present research describes frozen green beans (Phaseolus vulgaris, L.) quality retention profile during the recommended ‘star marking’ system dates, at the storage temperatures of þ5,26, 212 and 218 8C (along 1, 4, 14 and 60 days, respectively). The quality profile was assessed by a simulation system. Simulations were set by a response surface methodology to access the effect of different packaging materials (thermal conductivities and thickness), surface heat transfer coefficient, and refrigerator dynamics (effect of refrigeration cycles at the different storage temperatures) on the average retentions of Ascorbic Acid, total vitamin C, colour and flavour. Green beans quality losses along frozen storage are significantly influenced by temperature, refrigerator dynamics and kinetic properties. Quality is also highly dependent on packaging materials thermal insulation (e.g. at temperatures above the melting point). Temperature cycles inside frozen chambers have a long term effect, and at the higher storage temperatures (e.g. T . 26 8C) are detrimental to frozen green beans quality after shorter periods

Social-ecological trends: managing the vulnerability of coastal fishing communities

The loss of biodiversity, including the collapse of fish stocks, affects the vulnerability of social-ecological systems (SESs) and threatens local livelihoods. Incorporating community-centered indicators and SES drivers and exposures of change into coastal management can help anticipate and mitigate human and/or coastal vulnerability. We have proposed a new index to measure the social-ecological vulnerability of coastal fishing communities (Index of Coastal Vulnerability [ICV]) based on species, ecosystem, and social indicators. The ICV varies from 0 (no vulnerability) to 1 (very high vulnerability) and is composed of 3 components: species vulnerability, i.e., fish biological traits; ecosystem vulnerability, i.e., environmental indicators of ecosystem health; and adaptive capacity, i.e., human ability to cope with changes. We tested the ICV of Brazil’s 17 coastal states. The average ICV for the Brazilian coast was 0.77, and variation was low among states. More than half of the coastal states revealed very high vulnerability (> 0.8). The ecosystem vulnerability values were worse than the adaptive capacity and species vulnerability values, and the North and Northeast regions were revealed to be vulnerable hot spots. Additionally, we investigated how the ICV related to specific anthropogenic risks, i.e., fish landing richness, fishery instability, market, coastal extension, and coastal population, and found that states with fewer species landings and higher coastal populations presented higher ICVs. At a time when human impacts are overtaking natural processes, understanding how these impacts lead to coastal vulnerability can help improve conservation policies. For this case study, we suggest both fisheries management measures and restoration of sensitive habitats to protect species and decrease vulnerability. The integrated evaluation developed here could be used as a baseline for coastal monitoring and conservation planning and be applied to coastal regions in which governments evaluate both social and biological aspects.Postprint2,51

A social-ecological approach to estimate fisher resilience: a case study from Brazil

Social-ecological systems (SESs), such as fishing communities, are human and biophysical subsystems that are intrinsically connected to one another and strongly depend on natural resources. That is why these human groups are usually the first to feel the effects of policies concerning fisheries and ocean governance and the most affected by them. These policies can potentially build or erode social-ecological resilience (SER), especially if they are coupled with environmental changes. SER assessments offer a valuable tool to identify human-nature linkages, and the implications and feedbacks in SESs when facing human-induced or natural changes. We created a SER index by combining interviews with fishers with environmental datasets on a fine scale that has never been presented for the Brazilian coast. This scale was then tested in marine protected areas that allow sustainable use. Our approach estimated SER from information on fisheries ecosystem services and adaptive capacity at the local scale, considering the individual and community levels. We synthesized blocks of critical indicators of an individual or community’s ability to build and maintain resilience in SESs, such as flexibility, ability to learn, ability to organize, assets, social capital, and ecological characteristics. We identified that fishers’ ability to learn and to organize, as well as the biological sensitivity of an ecosystem are determinant to enhancing SER in the studied coastal communities. A Bayesian model also showed that the fishers’ SER was related to socioeconomic factors, thereby indicating that older fishers, fishers who consistently catch more fish, and fishers with a higher reliance on fishing for their income presented lower index values. By knowing the variables that influence the ability of fishers to cope with changes to their SESs, we can devise smarter management approaches that may include compensatory mechanisms for more fragile fishers. Our findings can also inform decision making about where fisheries management strategies are likely to be more participative and effective in order to minimize the social impacts of policy decisions and increase SER in coastal communities.Postprint2,51

Fracture envelope estimation of a structural adhesive by dedicated fracture tests

Cohesive zone modelling (CZM) is widespread for the strength analysis of bonded joints. The fracture toughness (GC) is required to use CZM. A scarcely studied mixed-mode test is the Asymmetric Tapered Double-Cantilever Beam (ATDCB), which merges a Tapered Double-Cantilever Beam (TDCB) adherend with a Double-Cantilever Beam (DCB) adherend. This work addresses the ATDCB test to estimate the fracture envelope of a structural adhesive. TDCB and End-Notched Flexure (ENF) tests were also performed to acquire the tensile (GIC) and shear fracture toughness (GIIC), respectively. Numerically, mixed-mode CZM laws were constructed based on the obtained data, and the results were compared with experiments, to validate the CZM laws and the mixed mode propagation criterion. As a result, the best damage propagation criterion for mixed mode was estimated and validated.info:eu-repo/semantics/publishedVersio

Effect of material hybridization on the strength of scarf adhesive joints

Adhesively-bonded joints have become more efficient due to the improvement of adhesives’ characteristics. On the other hand, with the use of composites in structures it is possible to reduce weight. Due to this, new techniques are being explored, including adhesively-bonding different materials. Nowadays, in many high performance structures, it is necessary to combine composite materials with other light-weighted metals such as aluminium or titanium. This work reports on an experimental and numerical study for hybrid scarf joints between composite and aluminium adherends, and considering different values of the scarf angle (α). The numerical analysis by Finite Elements (FE), using the software Abaqus®, enabled the obtainment of peel (σy) and shear stresses (τxy), which are then used to discuss the strength between different joint configurations. Cohesive zone modelling (CZM) was used to predict the joint strength and the results were compared to the experiments for validation. The joints’ behaviour was highly dependent on α, and CZM were validated for the design process of hybrid scarf joints.info:eu-repo/semantics/publishedVersio

Evaluation of T-joints in aluminium structures under different geometries

30th International Conference on Flexible Automation and Intelligent Manufacturing (FAIM2021) -15-18 June 2021, Athens, GreeceThe adhesive bonding technique is nowadays very popular in industrial applications, and is gradually replacing other more traditional bonding methods (fastened, welded and riveted joints) due to some advantages. However, its application supposes accurate methods for strength prediction. As a result, the techniques to predict the strength of adhesive joints has highly evolved. The eXtended Finite Element Method (XFEM) is a recent innovation implemented over the (Finite Element Method) FEM that enables crack growth to be modelled. However, its application to adhesive joints is still scarce. This work consists of an experimental and XFEM analysis of aluminium alloy T-joints, adhesively-bonded with three adhesive types. A parametric study is undertaken regarding the curved adherends’ thickness (tP2), with values between 1 and 4 mm. The adhesives Araldite® AV138 (strong but brittle), Araldite® 2015 (less strong but moderately ductile) and the Sikaforce® 7752 (with the smallest strength but highly ductile) were tested. A comparative analysis between the different joints conditions was undertaken by plotting peel (σу) and shear (τxy) stresses. The XFEM predictive capabilities were tested with different damage initiation criteria. It was found that, provided that the modelling conditions are properly set, accurate numerical results can be found.info:eu-repo/semantics/publishedVersio

O cuidado na Atenção Primária à Saúde: a vivência de enfermeiras

Indexación: Scopus; Scielo.Objetivo: comprender el signifi cado de realizar cuidados de enfermería en la Atención Primaria de Salud desde la perspectiva de las enfermeras chilenas. Método: investigación cualitativa con enfoque desde la fenomenología social de Alfred Schütz. La recolección de datos fue realizada entre enero y abril del 2013, a través de entrevista con 13 enfermeras de Atención Primaria en Chile. Resultados: las enfermeras perciben el cuidado como una experiencia gratifi cante considerando un encuentro de subjetividades. Sin embargo, se sienten sobrecargadas por múltiples funciones a realizar y por presiones jerárquicas en el logro de las metas. Aspiran implementar cuidados innovadores manifi estados por el deseo de superar el cuidado tradicional y la efi ciencia de la gestión de los diversos niveles de atención de la salud. Conclusión: es importante discutir estos resultados en el contexto de la asistencia y especialmente en la formación, con el fi n de preparar mejor a las enfermeras que brindarán cuidados en este nivel de atención.OBJECTIVE: to understand the meaning of nursing care in primary health care from the perspective of Chilean nurses. METHOD: this was a qualitative study based on the social phenomenology of Alfred Schutz. Data was collected between January and April 2013, through interviews with 13 primary health care nurses in Chile. RESULTS: the nurses perceived primary care as a gratifying experience, considering it an encounter of subjectivities. However, they felt burdened with multiple functions and by the hierarchical pressure to achieve targets. They strived to implement innovative care, expressed by the desire to go beyond traditional care practices, and improve the efficiency of management at the various levels of health care. CONCLUSION: it is important to discuss the results of the present study in the context of health care and especially nursing education, with the goal of better preparing nurses who will deliver care at the primary health care level.Objetivo: compreender o signifi cado atribuído aos cuidados de enfermagem na Atenção Básica de Saúde por enfermeiras chilenas. Método: pesquisa qualitativa baseada na fenomenologia social de Alfred Schutz. Os dados foram coletados entre janeiro e abril de 2013, por meio de entrevistas com 13 enfermeiras de unidades de Atenção Básica em uma cidade do Chile. Resultados: as enfermeiras percebem o cuidado prestado como uma experiência gratifi cante, considerando-o um encontro de subjetividades. No entanto, elas se sentem sobrecarregadas pelas múltiplas funções que realizam e pelas pressões hierárquicas para cumprir metas. Elas se esforçam para implementar cuidados inovadores que possam superar o cuidado tradicional e aumentar a efi ciência da gestão nos vários níveis de atenção à saúde. Conclusão: é importante discutir estes resultados no contexto da assistência e especialmente na formação, com o objetivo de melhorar a preparação de enfermeiros trabalhando nesse nível de atenção.http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0034-71672018000700531&lng=en&tlng=e