Water-Soluble Polymers with Ceramic/Metal Nanoparticles for Use as Anode Materials in Lithium-Ion and Sodium-Ion Batteries

Aqueous solutions of poly(vinylpyrrolidone) (PVP) with 20, 25, and 28 wt.% concentrations were successfully spun into fibers by centrifugal spinning. The pristine PVP fibers were annealed and carbonized to produce flexible carbon fibers for use as binder-free anodes in lithium-ion and sodium-ion batteries. These flexible carbon fibers were prepared by developing a novel three-step heat treatment to reduce the residual stresses in the pristine PVP precursor fibers and to prevent fiber degradation during carbonization. The average diameters of the pristine, annealed, and carbonized fibers were obtained using scanning electron microscopy (SEM), which showed that the average diameter of the carbon fibers increased with increasing polymer concentration. Thermal characterization of the pristine and annealed fibers was carried out by thermogravimetric analysis (TGA). The TGA results showed that the annealed fibers yielded a residual mass percentage of 36.0 % while the pristine PVP fibers suffered a higher mass loss and only retained 26.5% of the original mass above 450 °C in an inert gas. The electrochemical performance of the carbon-fiber anodes was evaluated by conducting galvanostatic charge/discharge cycles, rate performance, cycle voltammetry experiments, and impedance tests. The 20, 25, and 28 wt.% derived binder-free anodes were tested in Li-ion and Na-ion half-cells. TiO2/C and Sn/C composite fibers were prepared by the centrifugal spinning of TiO2/PVP and Sn/PVP solutions and subsequent heat treatment. The successful preparation of centrifugally spun composite fibers from aqueous solutions was only achieved with TiO2. Based on existing results in the literature, a higher vapor pressure leads to faster solvent evaporation and promotes fiber formation. Thus, a mixture of 1:1 water:ethanol (wt./wt.) was used to prepare the Sn/PVP precursor fibers as well as TiO2/PVP precursor fibers. Nonetheless, the centrifugally spun Sn/C and TiO2/C composite fibers prepared with the PVP/water/ethanol precursor solutions had a larger average diameter than those prepared from PVP aqueous solutions, which affected their electrochemical performance. In order to understand the constraints impeding the formation of Sn/C composite fibers from aqueous solutions, the viscosity and surface tension of aqueous Sn/PVP and TiO2/PVP precursor solutions were investigated using a programable rheometer (BROOKFIELD, RVDV-III U) and Goniometer, Kyowa-DropMaster, respectively. The results showed that the addition of particles to the PVP aqueous solutions did not play a significant role in the viscosity nor the surface tension of the PVP aqueous solutions. Thus, other causes such as particle dispersion were investigated. It was observed that an inferior particle dispersion was obtained in water when compared to that in ethanol. Finally, alternative methods to produce composite fibers from polymer aqueous solutions are discussed for future research endeavors

Green supply management and performance: a resource-based view

This study develops and empirically tests, from the resource-based perspective, a conceptual framework linking green supply management and performance. The proposed model is tested using data from a sample of 126 automotive manufactures in China. The results suggest that both green purchasing personnel and green supplier selection have a significant positive effect on green supplier collaboration, and that building green collaboration with suppliers is significantly and positively related to both environmental and operational performance. Accordingly, knowledge and skill development of the purchasing function can be recognised as an important resource in building green supply capabilities and performance

Formalización de la minería artesanal en la rinconada y su impacto en la economía Regional

La actividad minera a pequeña escala denominada legalmente pequeña minería y minería artesanal, es una actividad plenamente reconocible en el país desde la década de 1980 y ratificada por la Ley 27 651. Su proceso a la informalidad se debe sobre todo a una combinación de supervivencia y oportunidad, muy ligada a la creciente pobreza y la falta de oportunidades de empleo. Este tipo de minería explota exclusivamente oro, y se encuentra en plena expansión debido a susaltas cotizaciones. A pesar de la amplia variedad de características de esta actividad que conforman la minería artesanal, se puede llegar al consenso de que trata de actividades mineras de pequeña escala, que utilizan tecnologías rudimentarias e intensivas en mano de obra, y con poca exigencia en cuanto a salud, seguridad y cuidado ambiental, y en algunos casos implementados con el uso de maquinaria. Tradicionalmente, este tipo de actividad se ha concentrado en cuatro zonas: Madre de Dios, sur medio (Ica, Arequipa y Ayacucho), Pataz (La Libertad) y Puno (Carabaya – San Antonio de Putina - Sandia). Recientemente con mayor concentración en las zonas mencionadas, este tipo de minería se convierte en la actividad económica predominante y sostén de la economía Regional y local. La importancia económica de la minería artesanal, representa el 12% de la producción nacional de oro, es decir, casi 25.000 kilogramos anuales. Prosiguiendo estable durante la última década. Aunque no se tiene un dato oficial del número de mineros con concesión minera o sin ella que se dedican a esta actividad, los estimados van hasta las 250.000; esta gran alza tendría que ver con la inclusión de personal contratado a tiempo parcial, mano de obra infantil hasta pallaqueras. Un efecto negativo que acompaña a las actividades de minería artesanal es su deficiente manejo administrativo y ambiental de parte de las Direcciones Regionales de Minería en cada Región

El instrumento de gestión ambiental correctivo en el proceso de formalización minera de los Distritos de Ananea, Ituata y San Gaban de la Región Puno

La informalidad en pequeña y minería artesanal es un problema en el Perú y Latinoamérica. Se da también en África, Asia. Y el mundo, esta actividad involucra directa e indirectamente 100 a 150 millones de personas que producen: Oro 20%, gemas 70% y diamantes 20%, se explica por situación de pobreza y ocurrencia de yacimientos que permiten una extracción simple. Perú proponen avances en reglamentación y legislaciones específicas: D.S. 014-92EM, Ley 27651, Decreto Legislativo 1105. El presente estudio “EL INSTRUMENTO DE GESTION AMBIENTAL CORRECTIVO EN EL PROCESO DE FORMALIZACION MINERA DE LOS DISTRITOS DE ANANEA, ITUATA Y SAN GABAN DE LA REGION PUNO”, propone como Objetivo general de la investigación, el determinar que, si viabiliza el proceso de formalización minera en los distritos de Ananea, Ituata y San Gabán de la Región Puno, Identificando además el costo económico de s/. 50 000.00 promedio en la formulación del IGAC por consultores debidamente acreditados a la DREM-Puno. Es notorio el incumplimiento de plazos en la revisión y aprobación de parte de evaluadores de la autoridad, así como modificaciones legales en componentes relacionados a los Recursos Humanos, restos arqueológicos, contratos de explotación, permisos de uso de terrenos superficiales y planes de minado, que demoran la obtención de las Licencias y por ende las Resoluciones de Inicio y Reinicio de Operaciones Mineras, así mismo en la metodología de investigación y las técnicas e instrumentación de recolección de datos se ha procesado un estudio de 84 mineros de los tres distritos. En conclusión en la Región Puno se empadronaron 10 600, 6 000 declaraciones de compromiso, 2 445 en etapa de saneamiento, 243 IGAC realizados, 29 aprobado. 20 mineros (empresas) han logrado formalizarse: 8 en proceso extraordinario y 12 en ordinario, que nos ubican como la región con mayor IGAC presentados y aprobados a nivel Nacional, los mismos que vienen operando, e implementando la presentación de RUC ante la SUNAT y así pagar sus impuestos de Ley, y produciendo en armonía con el medio ambiente

Openness to Technological Innovation, Supply Chain Resilience, and Operational Performance: Exploring the Role of Information Processing Capabilities

Increasing volatility in the global economy since the 2009 financial crisis, including the USA–China trade war and recent COVID-19 outbreak, has compelled businesses to build resilience to respond quickly to unexpected disruptions. Consistent with organizational information processing theory (OIPT), we posit that openness to technological innovation helps to build information processing capabilities (i.e., interfunctional coordination and interpartner informational justice), which are required to build supply chain resilience (SCR) and improve performance. Structural equation modeling is used to analyze survey data gathered from 241 Chinese manufacturers. The results reveal interfunctional coordination and interpartner informational justice fully mediate the relationship between openness to technological innovation and SCR, and information processing capabilities and SCR are significantly and positively associated with operational performance. This article extends OIPT by elucidating the role of openness to technological innovation and enhances the SCR literature by providing empirical evidence of the important roles for information processing capabilities. The findings provide a unique information processing perspective to help managers broaden their solutions against disruptive events, and thus avoid or minimize potential negative impacts on firms

Innovativeness and lean practices for triple bottom line:Testing of fit-as-mediation versus fit-as-moderation models

Purpose The purpose of this paper is to examine whether the fit between innovativeness and lean practices (LPs) can affect triple bottom line (TBL) performance. Two types of fit are tested: fit-as-mediation in which innovativeness creates TBL performance through the mediation of LPs and fit-as-moderation whereby the effects of innovativeness on TBL performance are moderated by LPs. Design/methodology/approach Structural equation modelling and moderated regression are used to test the fit-as-mediation and fit-as-moderation models using survey data collected from 241 manufacturers in China. Findings The results show that innovativeness is positively associated with LPs that emphasize operational excellence. Innovativeness indirectly affects all three TBL dimensions through the mediation of LPs, and LPs do not moderate the effects of innovativeness. The applicability of fit-as-mediation model suggests directing attention towards integrating innovation and LPs within same organizational units to achieve improved TBL performance. Practical implications The findings suggest manufacturers should involve employees within the same organizational unit embrace an integrated culture of innovativeness and LPs and avoid separate attention to innovativeness and LPs. Originality/value This is the first study of which the authors are aware developing and empirically testing both fit-as-mediation and fit-as-moderation models within the same study to understand how innovativeness and LPs work together to influence TBL performance. This study extends the boundaries of current understanding by examining how, when and why the innovativeness – LPs–TBL relationship arises between constructs central to our theories