2,156 research outputs found

    Numerical modelling of a high temperature power module technology with SiC devices for high density power electronics

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    This paper presents the development of a new packaging technology using silicon carbide (SiC) power devices. These devices will be used in the next power electronic converters. They will provide higher densities, switching frequencies and operating temperature than current Si technologies. Thus the new designed packaging has to take into account such new constraints. The presented work tries to demonstrate the importance of packaging designs for the performance and reliability of integrated SiC power modules. In order to increase the integrated density in power modules, packaging technologies consisting of two stacked substrates with power devices and copper bumps soldered between them were proposed into two configurations. Silver sintering technique is used as die-attach material solution. In order to assess the assembling process and robustness of these packaging designs, the thermo-mechanical behaviour is studied using FEM modelling. Finally, some recommendations are made in order to choose the suitable design for reliable power module

    Applications of Genomics in Regulatory Food Safety Testing in Canada

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    Recent developments in the field of pathogen genomics herald a new paradigm for analytical food microbiology in which pathogenic bacteria will be characterized on the basis of their genetic profile rather than traditional approaches relying on phenotypic properties. The ability to identify gene markers associated with virulence, antimicrobial resistance, and other properties relevant to the identification, risk profiling, and typing of foodborne bacterial isolates will play a critical role in informing regulatory decisions and tracing sources of food contamination. Here we present several scenarios illustrating current and prospective roles for pathogen genomics in food inspection

    Identificación de peligros y evaluación de los riesgos en la producción de envases de polipropileno para el sector pesquero de congelado

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    Universidad Nacional Agraria La Molina. Facultad de Pesquería. Departamento Académico de Acuicultura e Industrias PesquerasEl trabajo de suficiencia profesional tuvo por objetivo principal identificar los peligros, evaluar los riesgos y determinar los puntos críticos de control en la producción de envases de polipropileno para el sector pesquero de congelado según la norma BRCGS PACKAGING en la línea de termoformado de la empresa productora de envases plásticos para alimentos ZHENPAK S.A.C, durante el periodo de marzo 2021-febrero 2022 para ello la autora desempeño el cargo de consultora de sistemas integrado de gestión realizando el diagnóstico de la empresa basada en la normativa BRCGS PACKAGING, se obtuvo como propuesta de mejora: la elaboración de un plan HARA, donde se incluyen elementos relevantes a la descripción del producto, diagrama del proceso de la elaboración de productos termoformados, la aplicación de los principios del plan HARA, la matriz de análisis de peligros y evaluación de riesgos, el cual dio como resultado puntos de control durante los procesos de recepción de materia prima, extrusión , termoformado e impresión.The main objective of the professional sufficiency work was to identify the hazards, assess the risks and determine the critical control points in the production of polypropylene containers for the frozen fishing sector according to the BRCGS PACKAGING standard in the thermoforming line of the producing company. of plastic containers for food ZHENPAK S.A.C, during the period of March 2021-February 2022, for this the author held the position of consultant of integrated management systems, carrying out the diagnosis of the company based on the BRCGS PACKAGING regulations, it was obtained as an improvement proposal, the preparation of a HARA plan, which includes elements relevant to the description of the product, diagram of the process for the preparation of thermoformed products, the application of the principles of the HARA plan, the matrix of hazard analysis and risk assessment, the which resulted in control points during the processes of receiving raw material, extrusion, thermoforming and printing

    Etude du comportement mécanique des joints de brasure Au-Ge pour le report des composants SiC pour l’électronique de puissance haute température

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    Ce papier contribue à l'étude de nouvelles technologies d’assemblage des puces en SiC utilisées dans les modules de puissance hautes températures (250°C). En effet, parmi tous les matériaux entrant dans l’assemblage de ces modules de puissance, le matériau de report des puces sur les substrats fait partie des matériaux les plus susceptibles aux contraintes thermomécaniques. Ainsi, pour répondre aux problématiques d'assemblage de ces puces en SiC, de nouvelles solutions de brasure doivent être développées. L’alliage de brasure Au-Ge peut être utilisé comme alliage de brasure sans plomb pour la haute température grâce à ses bonnes propriétés thermiques et mécaniques. Dans cet article, l’étude du comportement mécanique des joints formés avec la brasure Au-Ge et les puces en SiC, a été réalisée dans le but d’évaluer la robustesse et la fiabilité de ces jonctions en haute température

    Towards a reliability analysis method of wide band gap power electronic components and modules

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    This study is addressing on the reliability of COTS (Commercial Off-The-Shelf) power electronic components and modules which could be used in high reliability systems such as aerospace systems. This paper details the first followed steps to achieve a reliability assessment of some COTS power devices. These first steps are: - Construction analyses for the determination of the packaging assembly technologies of COTS power devices; - Discussion on the material used in COTS power devices; - Synthesis of the potential failure risk analysis under harsh environments; - Determination of several accelerated ageing tests to check the potential failure modes and mechanisms in power electronic for aerospace systems

    Stakeholder workshop report: Women’s empowerment in agrifood systems governance (WEAGov) technical workshop: Nigeria pilot study

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    Inclusive governance and policies can promote adaptation to climate change as well as resilience of women in the agrifood system. The Women's impowerment in Agrifood Governance (WEAGov) is a diagnostic tool developed by IFPRI to help evaluate the extent to which women are empowered across the policy cycle related to agrifood systems. WEAGov provides a way to identify gaps and opportunities to raise women’s voice and agency at different stages of the policy cycle, and provides a basis for monitoring progress in women’s empowerment in agrifood systems governance over time. The workshop described here took place on May 11, 2023 in Abuja, Nigeria and included policymakers, researchers, and private sector representatives. The workshop familiarized stakeholders with the WEAGov assessment framework and collected valuable inputs and feedback on a recent WEAGov pilot study conducted in Nigeria. While participants largely validated the WEAGov indicators, they recommended key areas for improved measurement which will be incorporated into the assessment framework

    Genome Dynamics of Campylobacter jejuni in Response to Bacteriophage Predation

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    Campylobacter jejuni is a leading cause of food-borne illness. Although a natural reservoir of the pathogen is domestic poultry, the degree of genomic diversity exhibited by the species limits the application of epidemiological methods to trace specific infection sources. Bacteriophage predation is a common burden placed upon C. jejuni populations in the avian gut, and we show that amongst C. jejuni that survive bacteriophage predation in broiler chickens are bacteriophage-resistant types that display clear evidence of genomic rearrangements. These rearrangements were identified as intra-genomic inversions between Mu-like prophage DNA sequences to invert genomic segments up to 590 kb in size, the equivalent of one-third of the genome. The resulting strains exhibit three clear phenotypes: resistance to infection by virulent bacteriophage, inefficient colonisation of the broiler chicken intestine, and the production of infectious bacteriophage CampMu. These genotypes were recovered from chickens in the presence of virulent bacteriophage but not in vitro. Reintroduction of these strains into chickens in the absence of bacteriophage results in further genomic rearrangements at the same locations, leading to reversion to bacteriophage sensitivity and colonisation proficiency. These findings indicate a previously unsuspected method by which C. jejuni can generate genomic diversity associated with selective phenotypes. Genomic instability of C. jejuni in the avian gut has been adopted as a mechanism to temporarily survive bacteriophage predation and subsequent competition for resources, and would suggest that C. jejuni exists in vivo as families of related meta-genomes generated to survive local environmental pressures

    Selection of Multidrug-Resistant Bacteria in Medicated Animal Feeds

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    Exposure to antimicrobial resistant (AMR) bacteria is a major public health issue which may, in part, have roots in food production practices that are conducive to the selection of AMR bacteria ultimately impacting the human microbiome through food consumption. Of particular concern is the prophylactic use of antibiotics in animal husbandry, such as the medication of feeds with sulfonamides and other antibiotics not considered clinically relevant, but which may nonetheless co-select for multi-drug resistant (MDR) bacteria harboring resistance to medically important antibiotics. Using a MDR Klebsiella pneumoniae strain exhibiting resistance to sulfonamides and beta-lactams (including carbapenem) as a model, we examined the ability of non-medicated and commercially medicated (sulfonamide) animal feeds to select for the model strain when inoculated at low levels by measuring its recovery along with key AMR markers, sul1(sulfonamide) and blaKPC-3 (meropenem), under different incubation conditions. When non-medicated feeds were supplemented with defined amounts of sulfadiazine the model strain was significantly enriched after incubation in Mueller Hinton Broth at 37°C overnight, or in same at room temperature for a week, with consistent detection of both the sul1 and blaKPC-3 markers as determined by polymerase chain reaction (PCR) techniques to screen colony isolates recovered on plating media. Significant recoveries of the inoculated strain and the sul1 and blaKPC-3 markers were observed with one of three commercially medicated (sulfamethazine) feeds tested under various incubation conditions. These results demonstrate that under certain conditions the prophylactic use of so-called non-priority antibiotics in feeds can potentially lead to co-selection of environmental AMR bacteria with resistance to medically important antibiotics, which may have far-reaching implications for human health

    Evolución jurisprudencial de la caducidad como claúsula expcepcional del contrato estatal

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    La Administración tiene, en virtud de la ley, poderes exorbitantes que tienen su justificación en el interés público, ya que su objetivo consiste en la protección, prevalencia o predominio general y son excepcionales pues no son de uso habitual y de obligatorio cumplimiento por encontrarse taxativamente en normas de orden público; de interpretación restrictiva y delimitadas material y temporalmente. En el presente artículo se realiza un estudio de la jurisprudencia sobre las diferentes posiciones de la Jurisprudencia frente al límite temporal en que se ejerce la declaratoria de la cláusula de caducidad por parte de la Administración, es decir, desde cuándo y hasta cuándo puede hacer uso de ella. La Sala Plena de la Sección Tercera profirió una sentencia de unificación jurisprudencial, que sostiene que sólo durante el plazo del contrato se puede declarar la caducidad, de manera que tan pronto vence, aunque siga en ejecución, no es posible hacerlo, a pesar de la posición anterior, mediante la cual era posible en el periodo de liquidación del contrato.The Administration has, by law, exorbitant powers which have their justification in the public interest, since their objective is protection, are exceptional because they are not commonly used and compulsory because they are limited to rules of public policy, restrictive interpretation, material and temporary delimitation. In this article, a study is made of the jurisprudence on the different positions of the Court of First Instance with regard to the time limit for declaring the revocation clause by the Administration, That is, from when and until when you can make use of it. The Full Chamber of Section Three issued a judgment of unification of case law, which holds that only during the term of the contract can the revocation be declared, so that as soon as it expires, even if it remains in execution, it is not possible to do so, despite the previous position, whereby it was possible in the contract liquidation period
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