The effects of Nordic Walking on health in adults: A systematic review

Objective: Nordic walking is a physical activity gaining more and more interest among adults. The aim of the study was to conduct a systematic review to determine the effects of Nordic walking on the physical and mental health of adults Method: We identified Nordic walking related randomized controlled trials (RCTs) in the electronic databases PubMed, EBSCO and CNKI, however 19 from 47 studies were selected for evaluation and systematic review based on relevant data. Results: Most of the study subjects were in the middle-aged and elderly clinical population, and three studies included non-clinical populations. The intervention was conducted most often three times a week for 8 weeks or more. The main effects of Nordic Walking were physical and psychological beniphytes, in particular the improvement of circulatory and respiratory and quality of life. All studies reported at least one beneficial effect of Nordic walking compared to the control group. Conclusion: Nordic walking has some beneficial effects on the physical and mental health of adults with or without clinical symptoms

High-performance all-polymer solar cells based on fluorinated naphthalene diimide acceptor polymers with fine-tuned crystallinity and enhanced dielectric constants

© 2018 Elsevier Ltd. This manuscript version is made available under the CC-BY-NC-ND 4.0 license: http://creativecommons.org/licenses/by-nc-nd/4.0/ This author accepted manuscript is made available following 24 month embargo from date of publication (Jan 2018) in accordance with the publisher’s archiving policyGrowing interests have been devoted to the synthesis of polymer acceptors as alternatives to fullerene derivatives to realize high-performance and stable all-polymer solar cells (all-PSCs). So far, one of the key factors that limit the performance of all-PSCs is low photocurrent density (normally < 14 mA/cm2). One potential solution is to improve the dielectric constants (εr) of polymer:polymer blends, which tend to reduce the binding energy of excitons, thus boosting the exciton dissociation efficiencies. Nevertheless, the correlation between εr and photovoltaic performance has been rarely investigated for all-PSCs. In this work, five fluorinated naphthalene diimide (NDI)-based acceptor polymers, with different content of fluorine were synthesized. The incorporation of fluorine increased the εr of the acceptor polymers and blend films, which improved the charge generation and overall photocurrent of the all-PSCs. As a result, the PTB7-Th:PNDI-FT10 all-PSC attained a high power conversion efficiency (PCE) of 7.3% with a photocurrent density of 14.7 mA/cm2, which surpassed the values reported for the all-PSC based on the non-fluorinated acceptor PNDI-T10. Interestingly, similarly high photovoltaic performance was maintained regardless of a large variation of donor:acceptor ratios, which revealed the good morphological tolerance and the potential for robust production capability of all-PSCs

An Investigation of the Quantitative Correlation between Urban Spatial Morphology Indicators and Block Wind Environment

The research purpose of this work is guiding the spatial morphological design of blocks via relevant indicators to realize suitable wind environments. In doing so, it is necessary to find the most suitable indicator types and value ranges for each urban spatial morphology. At present, most of the relevant research has been based on the numerical simulation of ideal block shapes and rarely proposes results based on actual block types, which often tend to be complex environments. Therefore, this paper firstly presents a theoretical speculation on the main factors influencing indicator effectiveness via analyzing physical significance and formulating principles for each indicator. These speculations are verified via wind environment measurement and statistical analysis, indicating that porosity (P0) can be used as an important indicator to guide the design of block wind environments in the case of deep street canyons, while frontal area density (λF) can be used as a supplement in shallow street canyons with no height differences. Finally, computational fluid dynamics (CFD) is used to quantify the impact of block height difference and street canyon depth on λF and P0, thereby finding suitable types of urban form and value ranges for λF and P0. This paper provides a feasible wind environment index system for urban designers

Evaluation of the Coupled and Coordinated Relationship between Agricultural Modernization and Regional Economic Development under the Rural Revitalization Strategy

Agriculture is one of the three major industries in China, and its level of development occupies an important position in the development of the national economy. At present, China vigorously promotes the strategy of rural revitalization, which provides new opportunities for agricultural modernization. Since modern agriculture and regional economy are coupled in a mutually influencing and constraining relationship, this paper constructs a coupled and coordinated evaluation index system of agricultural modernization and regional economic development. Using the entropy value method and coupled coordination degree model, the comprehensive development level and coordinated development degree of agricultural modernization and regional economic development of 31 provinces, autonomous regions, and cities in China from 2011 to 2020 were evaluated, revealing the time evolution and spatial distribution characteristics of the two systems. The results show that: (1) In the past decade, China’s agricultural modernization and regional economy have made some progress in terms of their respective development levels and the degree of coupling and coordination between them. (2) In terms of spatial evolution, there are obvious regional differences between the two systems, and the coupling coordination degree shows a “ladder” distribution pattern from the east to the central, northeastern, and western parts of the country. (3) Regions with a high level of regional economic development also have a relatively high degree of coupling and coordination between agricultural modernization and regional economic development. Our results provide insights into the economic effects of agricultural modernization in China and provide useful insights into the future direction of agricultural development programs in countries around the world

Bed inventory balance and stability of dual circulating fluidized bed systems

Experiments and modelling are conducted for general understanding on the imbalance phenomenon and for discussion on the strategies to improve the bed inventory balance and stability of a dual circulating fluidized bed (DCFB) system. The experiments are carried out in a 15.5 m high pilot-scale DCFB cold test system. A fluid-dynamic DCFB model is developed based on a 1.5-dimensional semi-empirical model of an industrial CFB boiler, validated by experimental data. The effects of control methods and operation conditions on the bed inventory balance and on the stability of the pilot- and large-scale DCFB systems are discussed. A “stable-unbalanced” state, where the system reaches a steady state, consisting of unbalanced bed inventories, is observed in both experiments and model simulation. To maintain a balanced state and similar bed inventory in the DCFB systems with similar cross-sectional areas, it is recommended to keep similar total pressure drops or gas velocities in both reactors

Effects of composite mixture of protein sources in replacing fish meal on nutritional value and flavor quality of Pacific white shrimp (Litopenaeus vannamei)

An 8-week feeding trial was conducted to investigate the effects of fish meal partially or totally replaced with poultry by-product meal (PBM), antarctic krill meal (AKM), corn gluten meal (CGM), cottonseed meal (CM) and rice protein concentrate meal (RPM) on amino acids, fatty acids, nucleotides and volatile compounds of Pacific white shrimp (Litopenaeus vannamei). Results showed that shrimps fed with partial replacement of fish meal (50 %) with AKM and PBM (1:1) significantly increased the content of inosine monophosphate (IMP), the proportion of eicosapentaenoic acid (EPA), n-9 monounsaturated fatty acids (MUFAs), and significantly decreased the content of hypoxanthine (Hx), benzaldehyde, and the proportion of saturated fatty acids (SFAs). Dietary fish meal totally replaced by the whole-plant protein diet resulted in a lower value of essential amino acids to total amino acids (EAA / TAA), n-3 / n-6 PUFAs, and a lower proportion of docosahexaenoic acid (DHA), n-3 polyunsaturated fatty acid (PUFAs). Principal component analysis and hierarchical cluster analysis revealed that shrimps fed diet with fish meal partially replaced by AKM and PBM (1:1) had the most similar volatile compounds profile to the fish meal-based diet. These results indicated that the composite mixture of PBM and AKM (1:1) is an excellent substitution for fish meal in shrimp diets

An enhanced thermal model with virtual resistance technique for pouch batteries at low temperature and high current rates

In this paper, an enhanced thermal model is proposed for pouch batteries, which can be used for a battery management system (BMS) at low temperatures and high current rates. This thermal model integrates a virtual resistance model (VRM) and post resistance model at low temperatures. Firstly, based on the Arrhenius equation, the resistance model at low temperatures (from 0 °C to -10 °C) and high discharge rates (from 3.125C to 12.5C) is extrapolated from the resistance model under room temperature conditions. In this context, the resistance model at low temperatures is regarded as the VRM. In comparison to the experimental results, the maximum error of this VRM is 0.851 mΩ. Additionally, the equivalent post resistance model of the pouch battery, including that of the positive electrode and negative electrode, is also given for low temperatures. Finally, the complete thermal model for pouch batteries is validated at low temperatures and high discharge rates. The temperature evolution at different points on the battery, along with the heat generation properties of the battery, are simulated under cyclic pulse current and constant current working conditions. For cyclic pulse current, the maximum mean error in terms of temperature evolution is 0.72 °C, and for constant current working conditions, the maximum mean error is 0.79 °C

Design of an industrial chemical looping gasification system

A design methodology for an industrial Chemical Looping Gasification (CLG) unit is proposed, including the reactor system, oxygen carrier, solid fuel, key parameters, mass and energy balance, reactor dimension, and emissions. To determine a reactor system for CLG, the first design step is to choose between four types of systems and their applicability. The selection of a circulating material and a particle size of the oxygen carrier and the solid fuel is discussed. Determination of the key operating parameters comprises oxygen-to-fuel ratio, steam-to-fuel ratio, charging/discharging of the oxygen carrier and the conversion difference between an air reactor and a fuel reactor, their temperatures, velocities in each reactor, and cyclone efficiency. As design basis, the mass and energy balance of the system is computed based on the distribution of syngas composition and oxygen transportation over the system. It is not critical to obtain an adequate circulation for a CLG unit. But to satisfy the heat balance, oxygen transport and reasonable efficiency of syngas production at the same time makes CLG technology challenging. More work is needed for the introduced design items in the case of commercial-scale units