scholarly journals Research on the Microclimate of Protected Agriculture Structures Using Numerical Simulation Tools: A Technical and Bibliometric Analysis as a Contribution to the Sustainability of Under-Cover Cropping in Tropical and Subtropical Countries

2021 ◽  
Vol 13 (18) ◽  
pp. 10433
Author(s):  
Gloria Alexandra Ortiz Rocha ◽  
Maria Angelica Pichimata ◽  
Edwin Villagran
Keyword(s):  
Numerical Simulation ◽  
Natural Ventilation ◽  
Cfd Simulation ◽  
Technical Information ◽  
Scientific Production ◽  
Future Research ◽  
Climate Control ◽  
Climate Conditions ◽  
Different Types ◽  
Search For Information

The use of protected agriculture structures in tropical and subtropical countries is the main alternative for intensification of agricultural production selected by producers. In general, in these regions, passive and plastic-covered structures predominate, with natural ventilation as the only method of climate control. This phenomenon has been widely studied in different types of structures using computational fluid dynamics (CFD) simulation. Therefore, this review aimed to collect and analyze the publications generated in this field of knowledge between 2010 and 2020. The search for information included the main academic databases available on the web and the analysis was carried out using bibliometric techniques, from which it was possible to identify details inherent to the scientific production, such as countries of origin, main authors, journals, and citations. Likewise, a detailed breakdown of the relevant technical information of the three phases of numerical simulation, such as preprocessing, processing, and postprocessing, was carried out. A compilation of 118 papers published in 65 journals, written by 256 authors, originating from 24 countries was achieved, where it was evident that Mexico and Colombia were the countries with the highest scientific production in the last decade. These papers analyzed, together, a total of 17 different types of structures where polyethylene-covered greenhouses predominated, with steady state simulations, for daytime climate conditions and without the presence of crops. Within the current and future research trends, the predominance of studies analyzing passive climate control methods, new models of insect-proof mesh-house structures, and, finally, studies focused on the structural analysis of greenhouses was found.

scholarly journals Systematic reviews and meta-analysis in nutrition research

2019 ◽  
Vol 122 (11) ◽  
pp. 1279-1294 ◽  
Author(s):  
George A. Kelley ◽  
Kristi S. Kelley
Keyword(s):  
Systematic Reviews ◽  
Meta Analysis ◽  
Technical Information ◽  
Major Elements ◽  
Future Research ◽  
High Quality ◽  
Nutrition Research ◽  
Production And Consumption ◽  
Different Types ◽  
Meta Analyses

AbstractThere exists an ever-increasing number of systematic reviews, with or without meta-analysis, in the field of nutrition. Concomitant with this increase is the increased use of such to guide future research as well as both practice and policy-based decisions. Given this increased production and consumption, a need exists to educate both producers and consumers of systematic reviews, with or without meta-analysis, on how to conduct and evaluate high-quality reviews of this nature in nutrition. The purpose of this paper is to try and address this gap. In the present manuscript, the different types of systematic reviews, with or without meta-analyses, are described as well as the description of the major elements, including methodology and interpretation, with a focus on nutrition. It is hoped that this non-technical information will be helpful to producers, reviewers and consumers of systematic reviews, with or without meta-analysis, in the field of nutrition.

A Numerical Simulation of VOCs Distribution in Indoor Environment of a Dormitory

2014 ◽  
Vol 548-549 ◽  
pp. 650-654
Author(s):  
Sun Bin ◽  
Zhi Hui Yang
Keyword(s):  
Numerical Simulation ◽  
Indoor Environment ◽  
Natural Ventilation ◽  
Cfd Simulation ◽  
Exhaust System ◽  
Simulation Method ◽  
Pollutant Concentration ◽  
Detailed Result ◽  
Resource Location ◽  
Indoor Pollutant

This document utilizes CFD simulation method to confirm the distribution of a new dormitory under the condition of natural ventilation and get the visible result and analyses the result of simulation and monitor. Because of the sealing of the room is nice, the result of the simulation value well agree with the true monitor value. By use of CFD simulation method the detailed result of indoor velocity field and pollutant concentration can be get easily. This document provides a method and theory to do further research on indoor pollutant concentration of different conditions, such as different exhaust system, different exhaust volume and different pollutant resource location.

Overview of Subsynchronous Oscillation in Grid-connected Wind Farm

2020 ◽  
Vol 13 (7) ◽  
pp. 969-979
Author(s):  
Xu Pei-Zhen ◽  
Lu Yong-Geng ◽  
Cao Xi-Min
Keyword(s):  
Power Systems ◽  
Wind Turbine ◽  
Large Scale ◽  
Wind Farm ◽  
Wind Farms ◽  
Induction Generator ◽  
Future Research ◽  
Stable Operation ◽  
Subsynchronous Oscillation ◽  
Different Types

Background: Over the past few years, the subsynchronous oscillation (SSO) caused by the grid-connected wind farm had a bad influence on the stable operation of the system and has now become a bottleneck factor restricting the efficient utilization of wind power. How to mitigate and suppress the phenomenon of SSO of wind farms has become the focus of power system research. Methods: This paper first analyzes the SSO of different types of wind turbines, including squirrelcage induction generator based wind turbine (SCIG-WT), permanent magnet synchronous generator- based wind turbine (PMSG-WT), and doubly-fed induction generator based wind turbine (DFIG-WT). Then, the mechanisms of different types of SSO are proposed with the aim to better understand SSO in large-scale wind integrated power systems, and the main analytical methods suitable for studying the SSO of wind farms are summarized. Results: On the basis of results, using additional damping control suppression methods to solve SSO caused by the flexible power transmission devices and the wind turbine converter is recommended. Conclusion: The current development direction of the SSO of large-scale wind farm grid-connected systems is summarized and the current challenges and recommendations for future research and development are discussed.

Antecedents and Consequences of Gossip in Work Groups

2019 ◽  
pp. 416-434
Author(s):  
Bianca Beersma ◽  
Gerben A. van Kleef ◽  
Maria T. M. Dijkstra
Keyword(s):  
Social Order ◽  
Information Exchange ◽  
Work Groups ◽  
Psychological Theory ◽  
Future Research ◽  
Group Norms ◽  
Group Effectiveness ◽  
Interpersonal Aggression ◽  
Different Types ◽  
Antecedents And Consequences

This chapter provides an overview of the antecedents and consequences of gossip in work groups. First, the chapter reviews the different motives for gossip in work groups (i.e., bonding, entertainment, emotional venting, information exchange, maintenance of group norms/social order, and interpersonal aggression) and links each motive to psychological theory. Second, the chapter reviews the different types of influence that gossip can have on various indicators of group effectiveness. Reflecting on the motives underlying gossip in work groups, as well as on its outcomes, it argues that future research should start integrating the diverse insights provided by earlier research on both gossip motives and outcomes, and it provides a number of suggestions for doing so.

scholarly journals Advantages and potential challenges of data management in e-maintenance

2019 ◽  
Vol 25 (3) ◽  
pp. 378-396 ◽  
Author(s):  
Arian Razmi-Farooji ◽  
Hanna Kropsu-Vehkaperä ◽  
Janne Härkönen ◽  
Harri Haapasalo
Keyword(s):  
Data Management ◽  
Design Methodology ◽  
Management Practices ◽  
Future Research ◽  
Conceptual Approach ◽  
Content Type ◽  
Different Types ◽  
Maintenance Systems ◽  
Industry Leader ◽  
Practical Implications

Purpose The purpose of this paper is twofold: first, to understand data management challenges in e-maintenance systems from a holistically viewpoint through summarizing the earlier scattered research in the field, and second, to present a conceptual approach for addressing these challenges in practice. Design/methodology/approach The study is realized as a combination of a literature review and by the means of analyzing the practices on an industry leader in manufacturing and maintenance services. Findings This research provides a general understanding over data management challenges in e-maintenance and summarizes their associated proposed solutions. In addition, this paper lists and exemplifies different types and sources of data which can be collected in e-maintenance, across different organizational levels. Analyzing the data management practices of an e-maintenance industry leader provides a conceptual approach to address identified challenges in practice. Research limitations/implications Since this paper is based on studying the practices of a single company, it might be limited to generalize the results. Future research topics can focus on each of mentioned data management challenges and also validate the applicability of presented model in other companies and industries. Practical implications Understanding the e-maintenance-related challenges helps maintenance managers and other involved stakeholders in e-maintenance systems to better solve the challenges. Originality/value The so-far literature on e-maintenance has been studied with narrow focus to data and data management in e-maintenance appears as one of the less studied topics in the literature. This research paper contributes to e-maintenance by highlighting the deficiencies of the discussion surrounding the perspectives of data management in e-maintenance by studying all common data management challenges and listing different types of data which need to be acquired in e-maintenance systems.

scholarly journals Advances in Forest Robotics: A State-of-the-Art Survey

Robotics ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 53
Author(s):  
Luiz F. P. Oliveira ◽  
António P. Moreira ◽  
Manuel F. Silva
Keyword(s):  
Future Research ◽  
Navigation Systems ◽  
Public And Private ◽  
Environmental Preservation ◽  
The Public ◽  
Forest Exploitation ◽  
Different Types ◽  
Scientific Papers ◽  
Great Relevance ◽  
Robotic Applications

The development of robotic systems to operate in forest environments is of great relevance for the public and private sectors. In this sense, this article reviews several scientific papers, research projects and commercial products related to robotic applications for environmental preservation, monitoring, wildfire firefighting, inventory operations, planting, pruning and harvesting. After conducting critical analysis, the main characteristics observed were: (a) the locomotion system is directly affected by the type of environmental monitoring to be performed; (b) different reasons for pruning result in different locomotion and cutting systems; (c) each type of forest, in each season and each type of soil can directly interfere with the navigation technique used; and (d) the integration of the concept of swarm of robots with robots of different types of locomotion systems (land, air or sea) can compensate for the time of executing tasks in unstructured environments. Two major areas are proposed for future research works: Internet of Things (IoT)-based smart forest and navigation systems. It is expected that, with the various characteristics exposed in this paper, the current robotic forest systems will be improved, so that forest exploitation becomes more efficient and sustainable.

scholarly journals Impact of Air Infiltration on IAQ and Ventilation Efficiency in Higher Educational Classrooms in Spain

2021 ◽  
Vol 13 (12) ◽  
pp. 6875
Author(s):  
Irene Poza-Casado ◽  
Raquel Gil-Valverde ◽  
Alberto Meiss ◽  
Miguel Ángel Padilla-Marcos
Keyword(s):  
Natural Ventilation ◽  
Well Being ◽  
Cold Season ◽  
Climate Conditions ◽  
Air Infiltration ◽  
Ventilation Efficiency ◽  
Educational Buildings ◽  
Set Up ◽  
Total Volatile Organic Compounds ◽  
The Impact

Indoor air quality (IAQ) in educational buildings is a key element of the students’ well-being and academic performance. Window-opening behavior and air infiltration, generally used as the sole ventilation sources in existing educational buildings, often lead to unhealthy levels of indoor pollutants and energy waste. This paper evaluates the conditions of natural ventilation in classrooms in order to study how climate conditions affect energy waste. For that purpose, the impact of the air infiltration both on the IAQ and on the efficiency of the ventilation was evaluated in two university classrooms with natural ventilation in the Continental area of Spain. The research methodology was based on site sensors to analyze IAQ parameters such as CO2, Total Volatile Organic Compounds (TVOC), Particulate Matter (PM), and other climate parameters for a week during the cold season. Airtightness was then assessed within the classrooms and the close built environment by means of pressurization tests, and infiltration rates were estimated. The obtained results were used to set up a Computational Fluid Dynamics (CFD) model to evaluate the age of the local air and the ventilation efficiency value. The results revealed that ventilation cannot rely only on air infiltration, and, therefore, specific controlled ventilation strategies should be implemented to improve IAQ and to avoid excessive energy loss.

scholarly journals Solar Chimney Applications in Buildings

Encyclopedia ◽  
2021 ◽  
Vol 1 (2) ◽  
pp. 409-422
Author(s):  
Haihua Zhang ◽  
Yao Tao ◽  
Long Shi
Keyword(s):  
Natural Ventilation ◽  
Energy System ◽  
Assisted Ventilation ◽  
Building Envelope ◽  
Building Structures ◽  
Solar Chimney ◽  
Climate Conditions ◽  
And Performance ◽  
Modern Building ◽  
Ventilation Systems

A solar chimney is a renewable energy system used to enhance the natural ventilation in a building based on solar and wind energy. It is one of the most representative solar-assisted passive ventilation systems attached to the building envelope. It performs exceptionally in enhancing natural ventilation and improving thermal comfort under certain climate conditions. The ventilation enhancement of solar chimneys has been widely studied numerically and experimentally. The assessment of solar chimney systems based on buoyancy ventilation relies heavily on the natural environment, experimental environment, and performance prediction methods, bringing great difficulties to quantitative analysis and parameterization research. With the increase in volume and complexity of modern building structures, current studies of solar chimneys have not yet obtained a unified design strategy and corresponding guidance. Meanwhile, combining a solar chimney with other passive ventilation systems has attracted much attention. The solar chimney-based integrated passive-assisted ventilation systems prolong the service life of an independent system and strengthen the ventilation ability for indoor cooling and heating. However, the progress is still slow regarding expanded applications and related research of solar chimneys in large volume and multi-layer buildings, and contradictory conclusions appear due to the inherent complexity of the system.

Improving Sustainability of Housing in Ghana through Energy Efficient Climate Control Strategies

2012 ◽  
Vol 608-609 ◽  
pp. 1698-1704
Author(s):  
Abdul Manan Dauda ◽  
Hui Gao
Keyword(s):  
Natural Ventilation ◽  
Energy Savings ◽  
Control Strategies ◽  
Internal Heat ◽  
Climate Control ◽  
Housing Design ◽  
Artificial Lighting ◽  
Testing Procedures ◽  
Mass Housing ◽  
Design Changes

This paper aims at explaining testing procedures used to evaluate the potential of natural ventilation and daylighting applications to passive design of housing in Ghana. The objectives of research were to reduce energy costs and increase the sustainability of housing. From the results of these experiments actual and potential designs are illustrated and discussed. Mass housing results in multi-storey buildings which require substantial artificial lighting and ventilation. Also, with the increasing usage of glass for windows and doors in Ghana, even the shaded depths of buildings require additional daylight usually resulting in more energy consumption. By supplementing the internal lighting levels with daylight, reducing the internal heat load by shading windows to direct radiation and the utilization of natural ventilation over air conditioning where possible, significant energy savings are could be achieved. The research proposes mass housing design changes such as: delivering daylight above the suspended ceiling into the depths of the building by horizontal light pipes and natural ventilation, utilizing stack effect and wind siphonage, etc.

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