A condition-based opportunistic maintenance policy integrated with energy efficiency for two-component parallel systems

Purpose: In order to improve the energy utilization and achieve sustainable development, this paper integrates energy efficiency into condition-based maintenance(CBM) decision-making for two-component parallel systems. The objective is to obtain the optimal maintenance policy by minimizing total cost. Design/methodology/approach: Based on energy efficiency, the paper considers the economic dependence between the two components to take opportunistic maintenance. Specifically, the objective function consists of traditional maintenance cost and energy cost incurred by energy consumption of components. In order to assess the performance of the proposed new maintenance policy, the paper uses Monte-Carlo method to evaluate the total cost and find the optimal maintenance policy. Findings: Simulation results indicate that the new maintenance policy is superior to the classical condition-based opportunistic maintenance policy in terms of total economic costs. Originality/value: For two-component parallel systems, previous researches usually simply establish a condition-based opportunistic maintenance model based on real deterioration data, but ignore energy consumption, energy efficiency (EE) and their contributions of sustainable development. This paper creatively takes energy efficiency into condition-based maintenance(CBM) decision-making process, and proposes a new condition-based opportunistic maintenance policy by using energy efficiency indicator(EEI).Peer Reviewe

Inorganic molecular sieves: Preparation, modification and industrial application in catalytic processes

[EN] The increasing environmental concern and promotion of “green processes” are forcing the substitution of traditional acid and base homogeneous catalysts by solid ones. Among these heterogeneous catalysts, zeolites and zeotypes can be considered as real “green” catalysts, due to their benign nature from an environmental point of view. The importance of these inorganic molecular sieves within the field of heterogeneous catalysis relies not only on their microporous structure and the related shape selectivity, but also on the flexibility of their chemical composition. Modification of the zeolite framework composition results in materials with acidic, basic or redox properties, whereas multifunctional catalysts can be obtained by introducing metals by ion exchange or impregnation procedures, that can catalyze hydrogenation–dehydrogenation reactions, and the number of commercial applications of zeolite based catalysts is continuously expanding. In this review we discuss determinant issues for the development of zeolite based catalysts, going from zeolite catalyst preparation up to their industrial application. Concerning the synthesis of microporous materials we present some of the new trends moving into larger pore structures or into organic free synthesis media procedures, thanks to the incorporation of novel organic templates or alternative framework elements, and to the use of high-throughput synthesis methods. Post-synthesis zeolite modification and final catalyst conformation for industrial use are briefly discussed. In a last section we give a thorough overview on the application of zeolites in industrial processes. Some of them are well established mature technologies, such as fluid catalytic cracking, hydrocracking or aromatics alkylation. Although the number of zeolite structures commercially used as heterogeneous catalysts in these fields is limited, the development of new catalysts is a continuous challenge due to the need for processing heavier feeds or for increasing the quality of the products. The application of zeolite based catalysts in the production of chemicals and fine chemicals is an emerging field, and will greatly depend on the discovery of new or known structures by alternative, lower cost, synthesis routes, and the fine tuning of their textural properties. Finally, biomass conversion and selective catalytic reduction for conversion of NOx are two active research fields, highlighting the interest in these potential industrial applications.The authors acknowledge financial support from Ministerio de Ciencia e Innovacion (project Consolider-Ingenio 2010 MULTICAT).Martínez Sánchez, MC.; Corma Canós, A. (2011). Inorganic molecular sieves: Preparation, modification and industrial application in catalytic processes. Coordination Chemistry Reviews. 255(13-14):1558-1580. doi:10.1016/j.ccr.2011.03.014S1558158025513-1

To stream or not to stream? Exploring factors influencing impulsive consumption through gastronomy livestreaming

Purpose: In China, the practice of livestreaming while shopping has evolved from a form of entertainment into a new business strategy. In recent years, the gastronomy industry has also adopted livestreaming as a means of online promotion. Based on the stimulus–organism–response theoretical model, this study aims to investigate the effects of gastronomy livestreaming on viewers’ impulsive consumption by considering gamification, perceived professionalism and telepresence as causative factors. Design/methodology/approach: This study conducted a survey of gastronomy livestreaming viewers that received 1,093 responses. The effects of gamification, perceived professionalism and telepresence were then analyzed using partial least squares-path modeling and necessary condition analysis. Findings: This study finds that gamification, perceived professionalism and telepresence are sufficient conditions for explaining impulsive consumption. Innovativeness mediates the relationships between these factors and impulsive consumption. Furthermore, gamification and innovativeness represent necessary conditions for impulsive consumption. Practical implications: The findings of this study contribute to an enhanced understanding of livestreaming in the gastronomy industry. Based on these findings, managers in the gastronomy industry can use more interactive gamification activities and enhance telepresence to increase viewers’ impulsive consumption during livestreaming sessions. Originality/value: This study identifies the modalities through which gastronomy livestreaming can stimulate impulsive consumption. This is an early study to investigate the effect of experiences of gamification, perceived professionalism and telepresence on viewers’ impulsive consumption in the context of gastronomy livestreaming. In addition, this early study investigates the effect of gastronomy livestreaming innovativeness on impulsive consumption

Finger-powered electrophoretic transport of discrete droplets for portable digital microfluidics.

We report a finger-powered digital microfluidic device based on the electrophoretic transport of discrete droplets (EPD). An array of piezoelectric elements is connected in parallel to metal electrodes immersed in dielectric fluids. When deflected in a controlled sequence via human finger power, the piezoelectric elements charge and actuate droplets across each electrode pair through electrophoretic force. Successful droplet transportation requires the piezoelectric elements to provide both sufficient charge and voltage pulse duration. We quantify these requirements using numerical models to predict the electrical charges induced on the droplets and the corresponding electrophoretic forces. The models are experimentally validated by comparing the predicted and measured droplet translational velocities. We successfully demonstrated transport and merging of aqueous droplets over a range of droplet radii (0.6-0.9 mm). We further showed direct manipulation of body fluids, including droplets of saliva and urine, using our finger-powered EPD device. To facilitate practical implementation of multistep assays based on the approach, a hand/finger-rotated drum system with a programmable pattern of protrusions is designed to induce deflections of multiple piezoelectric elements and demonstrate programmable fluidic functions. An electrode-to-piezoelectric element connection scheme to minimize the number of piezoelectric elements necessary for a sequence of microfluidic functions is also explored. The present work establishes an engineering foundation to enable design and implementation of finger-powered portable EPD microfluidic devices

BECN1s, a short splice variant of BECN1, functions in mitophagy

<div><p>Mitochondria selective autophagy, known as mitophagy, plays a pivotal role in several biological processes, such as elimination of the damaged mitochondria, removal of the mitochondria from immature red blood cells and sperm. The defects in mitophagy are associated with a wide spectrum of human diseases, including neurodegenerative disease, aging, cardiac disease and autoimmune disease. However, the mechanism underlying mitophagy remains largely unclear. Here, we report the characterization of a novel splice variant of BECN1/Beclin 1, BECN1s, which is produced by an alternative splicing mechanism. BECN1s is primarily associated with the outer-membrane of mitochondria. Unlike unspliced BECN1, which is essential for nonselective macroautophagy induction, BECN1s is indispensible for mitochondria-selective autophagy. Furthermore, BECN1s plays an important role in starvation- and membrane depolarization-induced mitophagy. Taken together, our findings broaden the view of BECN1 as an important regulator in autophagy, and implicate BECN1s as a specific mitophagy mediator.</p></div

Effects of canopy gaps on N2O fluxes in a tropical montane rainforest in Hainan of China

Background and aims: Tropical montane rainforests play an important role in increasing atmospheric N2O concentration. Although accurate estimations of N2O fluxes in tropical montane rainforests are critical for predicting global climate change, there are still considerable uncertainties about the spatial and temporal variability of the emissions. This study aims to investigate the effects of canopy gap caused by typhoons on N2O emissions, a key factor for understanding the spatial heterogeneity and supporting environmental regulations. Methods: N2O fluxes were measured monthly using static chambers both inside and outside two large canopy gaps in the tropical montane rainforest of the Jianfengling National Natural Reserve on Hainan Island, south of China, from August 2012 to July 2013. Results: Mean annual N2O emissions were 2.19 +/- 0.43 kg N2O-N ha(-1) yr(-1) inside canopy gaps, and 1.19 +/- 0.29 kg N2O-N ha(-1) yr(-1) outside canopy gaps, revealing substantial differences in N2O emissions resulting from forest structure. Moreover, N2O emission rates within canopy gaps during the wet season (2.89 kg N2O-N ha(-1) yr(-1)) were significantly higher than those during the dry season (1.34 kg N2O-N ha(-1) yr(-1)), suggesting strong regulation of soil moisture and precipitation in controlling soil N dynamics. However, there were significant nonlinear relationships between N2O fluxes and water filled pore space, and soil temperature within canopy gaps, but no significant relationships were found under the closed canopy. Conclusions: Contribution of canopy gaps should be considered to avoid underestimation of N2O emission rates from disturbed forests. Interestingly, emissions from gaps are more strongly coupled with climate drivers (moisture and temperature), with important implications for climate change projections. Therefore, the further research is needed to study the biogeochemical processes and mechanisms behind such phenomenon. (C) 2017 Elsevier B.V. All rights reserved

Trimeric HIV Env provides epitope occlusion mediated by hypervariable loops

Hypervariable loops of HIV-1 Env protein gp120 are speculated to play roles in the conformational transition of Env to the receptor binding-induced metastable state. Structural analysis of full-length Env-based immunogens, containing the entire V2 loop, displayed tighter association between gp120 subunits, resulting in a smaller trimeric diameter than constructs lacking V2. A prominent basal quaternary location of V2 and V39 that challenges previous reports would facilitate gp41-independent gp120-gp120 interactions and suggests a quaternary mechanism of epitope occlusion facilitated by hypervariable loops. Deletion of V2 resulted in dramatic exposure of basal, membrane-proximal gp41 epitopes, consistent with its predicted basal location. The structural features of HIV-1 Env characterized here provide grounds for a paradigm shift in loop exposure and epitope occlusion, while providing substantive rationale for epitope display required for elicitation of broadly neutralizing antibodies, as well as substantiating previous pertinent literature disregarded in recent reports.peerReviewe