Scanning Tunneling Microscopy in the superconductor LaSb2

We present very low temperature (0.15 K) scanning tunneling microscopy and spectroscopy experiments in the layered superconductor LaSb$_2$. We obtain topographic microscopy images with surfaces showing hexagonal and square atomic size patterns, and observe in the tunneling conductance a superconducting gap. We find well defined quasiparticle peaks located at a bias voltage comparable to the weak coupling s-wave BCS expected gap value (0.17 meV). The amount of states at the Fermi level is however large and the curves are significantly broadened. We find T$_c$ of 1.2 K by following the tunneling conductance with temperature.Comment: 5 pages, 4 figure

Low temperature magnetic transitions of single crystal HoBi

We present resistivity, specific heat and magnetization measurements in high quality single crystals of HoBi, with a residual resistivity ratio of 126. We find, from the temperature and field dependence of the magnetization, an antiferromagnetic transition at 5.7 K, which evolves, under magnetic fields, into a series of up to five metamagnetic phases.Comment: 5 pages, 5 figure

Magnetic and superconducting phase diagrams in ErNi2B2C

We present measurements of the superconducting upper critical field Hc2(T) and the magnetic phase diagram of the superconductor ErNi2B2C made with a scanning tunneling microscope (STM). The magnetic field was applied in the basal plane of the tetragonal crystal structure. We have found large gapless regions in the superconducting phase diagram of ErNi2B2C, extending between different magnetic transitions. A close correlation between magnetic transitions and Hc2(T) is found, showing that superconductivity is strongly linked to magnetism.Comment: 5 pages, 4 figure

Ship to line na Bosch Car Multimedia Portugal S.A.

Este artigo apresenta um estudo de caso desenvolvido na empresa Bosch Car Multimedia Portugal, que se dedica essencialmente à produção de sistemas multimédia (autorrádios e sistemas de navegação) para a indústria automóvel. Contém duas áreas produtivas, uma de produção de placas de circuitos impressos por inserção automática de componentes eletrónicos (SMD – Surface Mounted Device), e a outra, de inserção manual referente à montagem do aparelho final. O seu principal objetivo foi o de analisar o processo de abastecimento dos componentes que abastecem a área produtiva de inserção automática com vista a eliminar algumas movimentações desnecessárias dos componentes e a diminuir custos de inventário e de armazenamento. A metodologia adotada é baseada no conceito de Ship to Line (STL) no âmbito do Bosch Production System (BPS). Os resultados obtidos permitiram evidenciar as vantagens da utilização desta metodologia com ganhos muito significativos para a logística de abastecimento destes componentes

Designing with biological generative systems : choice by emotion

Consumers as co-producers or co-designers are frequently presented as the solution for mass-customization, but the success of these systems as enhancing emotional bonds between user and object seems to be questionable. Making choices may not be enough to generate a bigger connection between people and their things. Artifacts produced using biological systems with generative potential, where nature’s randomness and physiological processes have an important role in the definition of form, may have the capacity to foster the emotional connections that are missing, arising from nurturing and from an understanding of their morphogenesis, from the proximity and time required for their growth and development

Taxonomia de Beania (Bryozoa, Flustrina) de Arraial do Cabo, Estado do Rio de Janeiro, Brasil

Five species of Beania Johnston, 1840 (Bryozoa: Flustrina) were previously reported from Brazil, but only one, identified incorrectly in the literature as B. intermedia (Hincks, 1881), was reported from Rio de Janeiro State. In this study, we describe three species of Beania from Arraial do Cabo, Rio de Janeiro State: Beania klugei Cook, 1968 (=B. intermedia sensu Marcus, 1937), Beania mirabilis Johnston, 1840, and Beania maxilladentata sp.nov. Beania mirabilis is a new record for Rio de Janeiro State. It is characterized by a long basal cauda, approximately as long as the rest of the autozooid, two pairs of oral spines, and usually five pairs of short marginal spines overarching the frontal membrane. Beania klugei is characterized by the absence of both oral and marginal spines, and by its large autozooids and small avicularia. Beania maxilladentata sp.nov. has autozooids with up to three pairs of marginal spines directed outwards; the distal end of the autozooid never overlaps the proximal end of the next zooid in series; and the avicularia are as long as wide, with mandibles with accessory tips. Our study raises the number of species of Beania known in Rio de Janeiro State from one to three, and along the Brazilian coast from five to six.Cinco espécies de Beania Johnston, 1840 (Bryozoa: Flustrina) são conhecidas do Brasil, mas somente uma, identificada incorretamente na literatura como B. intermedia (Hincks 1881), é conhecida do Estado do Rio de Janeiro. Neste estudo, descrevemos três espécies de Beania de Arraial do Cabo, Estado do Rio de Janeiro: Beania klugei Cook, 1968 (=B. intermedia sensu Marcus, 1937), Beania mirabilis Johnston, 1840 e Beania maxilladentata sp.nov. Beania mirabilis Johnston, 1840 é um novo registro para a costa do Rio de Janeiro; é caracterizada por apresentar uma longa cauda basal, aproximadamente tão longa quanto o resto do autozoóide, um par de espinhos orais e usualmente cinco pares de curtos espinhos marginais arqueados sobre a membrana frontal. Beania klugei é caracterizada pela ausência de espinhos orais e marginais, por seus autozoóides grandes e pequenas aviculárias. Beania maxilladentata sp.nov. é caracterizada por autozoóides com até três pares de espinhos marginais dirigidos para o exterior; a extremidade distal do autozoóide nunca recobre o autozoóide subseqüente; a aviculária é tão longa quanto larga e a mandíbula tem pontas acessórias. O número de espécies de Beania conhecidas aumentou de uma para três no Estado do Rio de Janeiro e de cinco para seis na costa brasileira

Memory demands in disaggregated HPC: How accurate do we need to be?

Disaggregated memory has recently been proposed as a way to allow flexible and fine-grained allocation of memory capacity, mitigating the mismatch between fixed per-node resource provisioning and the needs of the submitted jobs. By allowing the sharing of memory capacity among cluster nodes, overall HPC system throughput can be improved, due to the reduction of stranded and underutilized resources. A key parameter that is generally expected to be provided by the user at submission time is the job's memory capacity demand. It is unrealistic to expect this number to be precise. This paper makes an important step towards understanding the effect of overestimating the job memory requirements. We analyse the implications on overall system throughput and job response time. We leverage a disaggregated simulation infrastructure implemented on the popular Slurm resource manager. Our results show that even when the cost of a 60% increase in memory demands only increases a single job's user response time by 8%, the aggregate result of everybody doing so can be a 25% reduction in throughput and a 5 times increase in response time. These results show that GB-hours should be explicitly allocated in addition to core-hours.This work is part of a project that has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 754337 (EuroEXA); it has been supported by the Spanish Ministry of Science and Innovation (project TIN2015-65316-P and Ramon y Cajal fellowship RYC2018-025628-I), Generalitat de Catalunya (contracts 2014-SGR-1051 and 2014-SGR-1272), and the Severo Ochoa Programme (SEV-2015-0493).Peer ReviewedPostprint (author's final draft

Improving HPC system throughput and response time using memory disaggregation

© 2021 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes,creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.HPC clusters are cost-effective, well understood, and scalable, but the rigid boundaries between compute nodes may lead to poor utilization of compute and memory resources. HPC jobs may vary, by orders of magnitude, in memory consumption per core. Thus, even when the system is provisioned to accommodate normal and large capacity nodes, a mismatch between the system and the memory demands of the scheduled jobs can lead to inefficient usage of both memory and compute resources. Disaggregated memory has recently been proposed as a way to mitigate this problem by flexibly allocating memory capacity across cluster nodes. This paper presents a simulation approach for at-scale evaluation of job schedulers with disaggregated memories and it introduces a new disaggregated-aware job allocation policy for the Slurm resource manager. Our results show that using disaggregated memories, depending on the imbalance between the system and the submitted jobs, a similar throughput and job response time can be achieved on a system with up to 33% less total memory provisioning.This work is part of a project that has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 754337 (EuroEXA); it has been supported by the Spanish Ministry of Science and Innovation (project TIN2015-65316-P and Ramon y Cajal fellowship RYC2018-025628-I), Generalitat de Catalunya (contracts 2014-SGR-1051 and 2014-SGR-1272), and the Severo Ochoa Programme (SEV-2015-0493).Peer ReviewedPostprint (author's final draft