Graphene modifications with oxygen or hydrogen are well known in contrast to carbon attachment to the graphene lattice. The chemical modification of graphene sheets with aromatic diazonium ions ...(carbon attachment) is analyzed by confocal Raman spectroscopy. The temporal and spatial evolution of surface‐adsorbed species allows accurate tracking of the chemical reaction and identification of intermediates. The controlled transformation of sp2 to sp3 carbon proceeds in two separate steps. The presented derivatization is faster for single‐layer graphene and allows controlled transformation of adsorbed diazonium reagents into covalently bound surface derivatives with enhanced reactivity at the edge of single‐layer graphene. On bilayer graphene the derivatization proceeds to an adsorbed intermediate, which reacts slower to a covalently attached species on the carbon surface.
The chemical modification of graphene with diazonium chemistry is analyzed by confocal Raman spectroscopy. The reaction shows a clear selectivity between single‐ (1L) and bilayer (2L) graphene after ten minutes of reaction. The edge of the single‐layer‐graphene areas has an increased reactivity to the diazonium reagent and the local carbon hybridization changes from sp2 to sp3, altering the electronic properties of graphene.
•A new type of 3D Hall sensor for magnetic field measurements was designed and a prototype was fabricated.•The sensor consists of six specially designed and assembled 1D Hall sensors to form a ...miniature sub-mm active volume.•Ability for precise magnetic field measurements at the same point at the same time.•Planar Hall voltage reduction by more than 35 times.
The measurement of all three components of a magnetic field, simultaneously to high precision with Hall sensors, remains a challenge. Given the high precision of state-of-the-art conventional uniaxial Hall sensors, this is disappointing. Currently, three-axis Hall sensors suffer from either, or a combination, of the following: large spatial distribution between active areas; high signal noise; cross-sensitivity between measurement axes due to angular errors or the planar Hall effect; the inability to measure at a single point in space and time. A new type of three-axis Hall sensor is proposed, consisting of three sets of uniaxial Hall sensors in a small active volume. The feasibility of the proposed sensor has been proven in a prototype with an active volume as small as 200μm×200μm×200μm. Due to its unique configuration, the new sensor addresses current three-axis Hall sensor limitations: it provides a high spatial resolution of 30μm×30μm×1μm for each field component; full field vector measurements practically at a single point in space and time; and a reduction of the planar Hall effect by a factor of 35. Angular errors between the individual Hall sensors in the prototype lie between 0.1° and 0.5°, above the tolerable error for non-corrected measurements. However, once understood they can be taken into account. With proper calibration, this type of three-axis Hall sensor has great potential for high-accuracy three-axis magnetic field measurements and is particularly suitable for field mapping of magnets.
Purpose
The purpose of this paper is to focus on the analysis of the characteristics and gaps of a literature fragment from the international scientific publications on performance evaluation in lean ...production, aiming to generate new knowledge and suggestions for future scientific research.
Design/methodology/approach
The authors have adopted “ProKnow-C” methodology, a qualitative research approach that is used for literature selection, identification, analysis and reflection on the established characteristics.
Findings
From a bibliographic portfolio of 67 research works, 91 per cent of the works have individual metrics and 84 per cent have sets of metrics. Evaluating the focus of the performance measurement system, 34 per cent of works measure performance, 43 per cent compare performance and only 18 per cent assist in strategic planning. Evaluating the phases of the PMS life cycle, 87 per cent attend to the design, and 66 per cent attend to the activities of data collection, allow diagnosis, evaluate performance and communicate results. However, only 3 per cent of the studies analysed the use of PMS after its implementation and no research evidenced the review of metrics and objectives based on strategic planning.
Research limitations/implications
The search formula to capture the bibliographic portfolio (BP) was limited to the following terms: performance measurement, performance evaluation, performance assess*, performance appraisal, management, indicator*, critical factors, best practices, lean production, lean manufacturing and lean system. The BP was determined based on the limitations set by the research authors: articles published in English and Portuguese languages, from 2000 to 2018, in the Engineering Village, Scopus, EBSCO, Web of Science, ProQuest and Science Direct databases, which were freely available on the internet. Lastly, conceptual knowledge was used to select the articles, so there is a chance that unintentional losses could happen.
Practical implications
As practical implications for practitioners, the authors have identified that a PMS from an organisation that aims to become “lean” needs to be defined and revised considering its strategy, adjusting its set of metrics and targets to the internal and external challenges. As practical implications for researchers, opportunities have been identified to develop longitudinal studies in PMS utilisation and review to understand how the measurement system must evolve over time through changes in the internal and external environments of organisations.
Originality/value
This research adds value because its results allow researchers and practitioners to visualise the boundaries of the knowledge from the BP, about performance management in lean production, and what their gaps are in relation to the reference model of performance evaluation. This research is original because it was not observed in the literature review, a research that used the ProKnow-C methodology for analysis of the alignment and gaps between lean production and performance evaluation.
An MCDA-C application to evaluate supply chain performance Della Bruna Jr, Emílio; Ensslin, Leonardo; Rolim Ensslin, Sandra
International journal of physical distribution & logistics management,
07/2014, Volume:
44, Issue:
7
Journal Article
Peer reviewed
Purpose
– The purpose of this paper is to develop a performance evaluation model for the operations of the supply chain of an organization of the refrigeration equipment sector. The tool must aid the ...decision maker in the performance improvement and creation of competitive advantages.
Design/methodology/approach
– The study adopts a mixture of qualitative and quantitative approaches and applies them through a case study. The data collection was conducted through unstructured interviews and supplemented by documentary research. The applied intervention instrument is the Multicriteria Decision Aid – Constructivist (MCDA-C).
Findings
– Identification, organization, ordinal and cardinal measurement and integration of the aspects of the context judged as relevant by the decision maker. In addition, it can be highlighted the current situation diagnosis and elaboration of improvement actions related to lean philosophy and advanced planning systems.
Practical implications
– The developed model is being used to aid the decision maker in their decisions concerning the improvement of the supply chain operations.
Originality/value
– The main contributions made by the paper resides in the proposal of solutions for fulfiling gaps identified within the supply chain performance evaluation area and in the application of the MCDA-C to a practical case.
Keywords
Performance, Supply chain, Multicriteria, Decision, MCDA-C
Paper type
Case study
Resumen
Objetivo
Objetivo
– El objetivo de este artículo es desarrollar un Modelo de Desempeño para las operaciones de cadena de suministro de una organización en el sector de equipos de refrigeración. La herramienta debe ayudar a quién toma las decisiones en mejorar el desempeño y crear ventajas competitivas.
Diseño/metodología/enfoque
– El estudio usa una combinación de enfoques cualitativos y cuantitativos aplicándolos a un caso estudio. La recolección de datos se hizo a través de entrevistas no estructuradas y se complementó con investigación documental. El instrumento de intervención usado es el Multicriterio De Apoyo a la Decisión-Constructivista (MCDA-C).
Hallazgos
– Identificación, organización, mediciones ordinales y cardinales e integración de los aspectos de los contextos considerados como relevantes por el tomador de decisiones. Se puede destacar además la situación actual de diagnóstico y la elaboración de acciones de mejoramiento relacionados con la filosofía Lean y los Sistemas avanzados de planificación.
Implicaciones prácticas
– El modelo desarrollado esta siendo usado para ayudar al toma decisiones en las decisiones concernientes con el mejoramiento de las operaciones de la cadena de suministro.
Originalidad/valor
– La mayor contribución hecha por este artículo reside en proponer soluciones para cubrir brechas identificadas dentro el área de Evaluación de Rendimiento en la Cadena de Suministro y en la aplicación del MCDA-C a un caso práctico.
Palabras Claves
Desempeño, Cadena de Suministro, Decisión, Multicriterio, MCDA-C
Tipo de papel
estudio de caso
Resumo
Objetivo
Objetivo
– O objetivo de este artigo é desenvolver um Modelo de Avaliação Desempenho para as operações da cadeia de suprimentos de uma organização do setor de equipamentos de refrigeração. O modelo proposto deve ajudar o tomador de decisões a melhorar o desempenho e criar vantagens competitivas.
Desenho/metodologia/enfoque
– O estudo faz uso de uma abordagem qualitativa e quantitativa aplicada em um Estudo de Caso. A coleta dos dados foi feita por meio de entrevistas abertas, sendo complementada por pesquisa documental. O instrumento de intervenção usado é o Multicriteria Decision Aid – Constructivist (MCDA-C).
Achados
– Identificação, organização, medições ordinais e cardinais, e integração dos aspectos do contexto são considerados como relevantes para o tomador de decisões. Além disso, destacam-se o diagnóstico da situação atual e a elaboração de ações de aperfeiçoamento, nas quais se avaliam os efeitos da implementação da Filosofia Enxuta e de um Sistema de Planejamento Avançado na organização.
Implicações práticas
– O modelo desenvolvido auxilia o tomador de decisões nas decisões concernentes ao melhoramento das operações da cadeia de suprimentos.
Originalidade/valor
– As principais contribuições do artigo residem na proposição de melhorias em lacunas ainda presentes na avaliação do desempenho da cadeia de suprimentos e também na aplicação da MCDA-C em um caso prático.
Palavras-Chave
Desempenho, Cadeia de Suprimentos, MCDA-C, Decisão, Multicritério
Tipo de papel
estudo de caso
Rare plant species are suggested to be less resistant to herbivores than common species. Their lower apparency and the fact that they often live in isolated populations, resulting in fewer herbivore ...encounters, might have led to the evolution of reduced defences. Moreover, their frequent lower levels of genetic diversity compared with common species could negatively affect their resistance against enemies. However, the hypothesis that plant resistance depends on plant regional and local rarity, independently of habitat and competitive and growth strategy, lacks evidence. To test this hypothesis, we assessed the performance and preference of one belowground and three aboveground generalist invertebrate herbivores from different taxonomic groups as indicators of plant resistance. Herbivores were fed a total of 62 regionally and locally rare and common plant species from Switzerland. We accounted for differences in a plant's growth and competitive strategy and habitat resource availability. We found that regionally and locally rare and common plant species did not generally differ in their resistance to most generalist herbivores. However, one herbivore species even performed better and preferred locally and regionally common plant species over rarer ones, indicating that common species are not more resistant, but tend to be less resistant. We also found that all herbivore species consistently performed better on competitive and large plant species, although different herbivore species generally preferred and performed better on different plant species. The latter indicates that the use of generalist herbivores as indicators of plant‐resistance levels can be misleading. Synthesis: Our results show that rare plant species are not inherently less resistant than common ones to herbivores. Instead, our results suggest that the ability of plants to allocate resources away from defence towards enhancing their competitive ability might have allowed plants to tolerate herbivory, and to become locally and regionally common.
In our multi‐herbivore and multi‐plant species experiment, we address the link between plant resistance to herbivores and their local and regional rarity by putting it into context with their life‐history traits, habitats and evolutionary history. We found that rare plant species are not less resistant to herbivores than common ones. Instead, the ability of plants to allocate resources away from defence towards a stronger competitive ability might have allowed plants to tolerate herbivory and to become common.
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