scholarly journals Multilayers Polyethylene Film for Crop Protection in Harsh Climatic Conditions

2017 ◽  
Vol 2017 ◽  
pp. 1-7 ◽  
Author(s):  
A. Dehbi ◽  
B. Youssef ◽  
C. Chappey ◽  
A.-H. I. Mourad ◽  
P. Picuno ◽  
...  
Keyword(s):  
Surface Morphology ◽  
Tensile Test ◽  
Optical Microscopy ◽  
Significant Influence ◽  
Crop Protection ◽  
Thermal Characteristics ◽  
Climatic Conditions ◽  
Layer Film ◽  
Air Bubble ◽  
New Generation

In this work the performance and durability of a new generation of greenhouse covers, in which the cover is composed of five layers, are investigated. A sand wind ageing was performed under different exposure conditions. Surface morphology and chemical, physical, and thermal characteristics were investigated by using optical microscopy, FTIR, and tensile test techniques. In addition, the mechanical integrity of the five-layer film was assessed. The analysis indicated that the sand wind treatments have a significant influence only on the performance of the film. An attempt has been done to compare the properties of the five-layer film with the monolayer and trilayer films with or without air bubble under similar conditions. The results revealed that the five-layer film proved to be a promising greenhouse covering film.

scholarly journals Physical and gas permeation properties of five-layer polyethylene film used as greenhouse roof

2018 ◽  
Vol 49 (2) ◽  
pp. 124-129
Author(s):  
Abdelkader Dehbi ◽  
Boulos Youssef ◽  
Abdel-Hamid I. Mourad ◽  
Corinne Chappey ◽  
Pietro Picuno ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Contact Angle ◽  
Fourier Transform ◽  
Surface Morphology ◽  
Vinyl Acetate ◽  
Significant Influence ◽  
Experimental Analysis ◽  
Gas Permeation ◽  
Air Bubble ◽  
Permeation Properties

The effect of sand wind ageing simulation performed under different conditions for a five-layer film consisting of polyethylene, poly-vinyl-acetate and various additives has been investigated. The mechanical properties of the five-layer films after several treatments were evaluated, together with their surface morphology - analysed by using Fourier transform infrared and contact angle - and gas permeation properties. The experimental analysis indicated that these treatments had a significant influence on the surface of the film only. An attempt has been done to compare the properties of the five-layer films with the monolayer and tri-layer films with or without air bubble under similar conditions.

scholarly journals Electromechanical Assessment and Induced Temperature Measurement of Carbon Fiber Tows under Tensile Condition

Materials ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 4234
Author(s):  
Samir Mekid ◽  
Hammam Daraghma ◽  
Salem Bashmal
Keyword(s):  
Carbon Fiber ◽  
3D Printing ◽  
Tensile Test ◽  
Thermal Characteristics ◽  
Acrylonitrile Butadiene Styrene ◽  
Break Point ◽  
Host Material ◽  
Special Focus ◽  
Host Materials ◽  
Butadiene Styrene

The paper presents an investigation and analysis of the electromechanical and thermal characteristics of the carbon fiber alone as single tow and embedded in host materials such as polymer e.g., acrylonitrile butadiene styrene (ABS) using 3D printing. While carbon fibers can partially reinforce the structure, they can act as sensors to monitor the structural health of the host material. The piezo-resistive behavior was examined without any pretreatment of the carbon fiber under tensile test in both cases. Special focus on the filaments clamping types and their effects was observed. An auxetic behavior was exhibited; otherwise, the free part shows elastic and yielding ranges with break point at high resistance. An induced temperature of the carbon fiber was measured during the tensile test to show low variation. The carbon fiber can provide strength contribution to the host material depending on the percentage of filling the material in 3D printing. The relative variation of the electrical resistance increases by 400% while embedded in the host material, but decreases as the tows filament density increases from 1 to 12 K.

scholarly journals Thermal extras of vegetation walls in Belgrade climatic conditions

2018 ◽  
Vol 22 (Suppl. 3) ◽  
pp. 945-955 ◽  
Author(s):  
Budimir Sudimac ◽  
Aleksandar Andjelkovic ◽  
Sanja Dubljevic
Keyword(s):  
Energy Balance ◽  
Thermal Characteristics ◽  
Climatic Conditions ◽  
Office Buildings ◽  
Sustainable Technologies ◽  
Summer Time ◽  
Outer Environment

The goal of this research is to analyse the possibility of using vegetation walls in order to improve the thermal characteristics of office buildings in Belgrade?s climatic conditions. The study analyses the possibility of integrating vegetation modules into the fa?ades of office buildings. The paper shows the potential of vegetation technologies in the realisation of fa?ade coverings of architectural buildings with a goal to reduce heat gained during summer time. The use of vegetation walls in architecture has opened up new planning possibilities and created planning conditions for reducing the energy necessary for cooling office buildings. Considering that interaction between the outer environment and inner solving the dependency between comfort, outer look and building?s energy balance. This paper is presenting the possibility of using sustainable technologies for solving the problem of overheating in Belgrade?s climatic conditions. The research considers the possibilities of using vertically greening systems in planning fa?ade coverings, with an analysis of their thermal characteristics for climatic conditions in Belgrade.

scholarly journals Synthesis of New Chiral Inducer and Preparation of Semi-Conducting Polymer Films Showing Fingerprint Structure

2014 ◽  
Vol 27 ◽  
pp. 6-12 ◽  
Author(s):  
Hiroki Hayashi ◽  
Kohsuke Kawabata ◽  
Hiromasa Goto
Keyword(s):  
Thin Film ◽  
Liquid Crystal ◽  
Surface Morphology ◽  
Optical Microscopy ◽  
Conducting Polymer ◽  
Electrolyte Solution ◽  
Cholesteric Liquid Crystal ◽  
Chiral Liquid Crystal ◽  
Conducting Polymer Films ◽  
Electrochemical Polymerisation

We synthesised a rod like shaped new chiral inducer to construct chiral liquid crystal electrolyte solution. Next, electrochemical polymerisation was carried out in the chiral liquid crystal electrolyte solution. The surface morphology of the polymers were observed with polarising optical microscopy. Synthesis of the new chiral inducer and preparation of semi-conducting thin film in the cholesteric liquid crystal electrolyte solution were performed.

scholarly journals On the probability of habitable planets

2013 ◽  
Vol 12 (3) ◽  
pp. 177-185 ◽  
Author(s):  
François Forget
Keyword(s):  
Liquid Water ◽  
Climate Models ◽  
Climatic Conditions ◽  
Point Of View ◽  
Habitable Zone ◽  
One Dimensional ◽  
The Past ◽  
Surface Liquid ◽  
New Generation ◽  
Global Mean

AbstractIn the past 15 years, astronomers have revealed that a significant fraction of the stars should harbour planets and that it is likely that terrestrial planets are abundant in our galaxy. Among these planets, how many are habitable, i.e. suitable for life and its evolution? These questions have been discussed for years and we are slowly making progress. Liquid water remains the key criterion for habitability. It can exist in the interior of a variety of planetary bodies, but it is usually assumed that liquid water at the surface interacting with rocks and light is necessary for emergence of a life able to modify its environment and evolve. The first key issue is thus to understand the climatic conditions allowing surface liquid water assuming a suitable atmosphere. These have been studied with global mean one-dimensional (1D) models which have defined the ‘classical habitable zone’, the range of orbital distances within which worlds can maintain liquid water on their surfaces (Kasting et al. 1993). A new generation of 3D climate models based on universal equations and tested on bodies in the solar system are now available to explore with accuracy climate regimes that could locally allow liquid water. The second key issue is now to better understand the processes which control the composition and the evolution of the atmospheres of exoplanets, and in particular the geophysical feedbacks that seem to be necessary to maintain a continuously habitable climate. From that point of view, it is not impossible that the Earth's case may be special and uncommon.

scholarly journals Toward a Reduced Reliance on Conventional Pesticides in European Agriculture

Plant Disease ◽  
2016 ◽  
Vol 100 (1) ◽  
pp. 10-24 ◽  
Author(s):  
Jay Ram Lamichhane ◽  
Silke Dachbrodt-Saaydeh ◽  
Per Kudsk ◽  
Antoine Messéan
Keyword(s):  
Crop Production ◽  
Crop Yields ◽  
Production Systems ◽  
Integrated Management ◽  
Crop Protection ◽  
Sustainable Use ◽  
Climatic Conditions ◽  
Pesticide Use ◽  
Eu Member States ◽  
European Agriculture

Whether modern agriculture without conventional pesticides will be possible or not is a matter of debate. The debate is meaningful within the context of rising health and environmental awareness on one hand, and the global challenge of feeding a steadily growing human population on the other. Conventional pesticide use has come under pressure in many countries, and some European Union (EU) Member States have adopted policies for risk reduction following Directive 2009/128/EC, the sustainable use of pesticides. Highly diverse crop production systems across Europe, having varied geographic and climatic conditions, increase the complexity of European crop protection. The economic competitiveness of European agriculture is challenged by the current legislation, which banned the use of many previously authorized pesticides that are still available and applied in other parts of the world. This challenge could place EU agricultural production at a disadvantage, so EU farmers are seeking help from the research community to foster and support integrated pest management (IPM). Ensuring stable crop yields and quality while reducing the reliance on pesticides is a challenge facing the farming community is today. Considering this, we focus on several diverse situations in European agriculture in general and in European crop protection in particular. We emphasize that the marked biophysical and socio-economic differences across Europe have led to a situation where a meaningful reduction in pesticide use can hardly be achieved. Nevertheless, improvements and/or adoption of the knowledge and technologies of IPM can still achieve large gains in pesticide reduction. In this overview, the current pest problems and their integrated management are discussed in the context of specific geographic regions of Europe, with a particular emphasis on reduced pesticide use. We conclude that there are opportunities for reduction in many parts of Europe without significant losses in crop yields.

scholarly journals Resource-Saving Methods for Growing Rice in the Krasnodar Territory

2021 ◽  
Vol 37 ◽  
pp. 00151
Author(s):  
Igor Prikhodko ◽  
Stanislav Vladimirov ◽  
Daniil Alexandrov
Keyword(s):  
Drip Irrigation ◽  
Optimal Solution ◽  
Sprinkler Irrigation ◽  
Climatic Conditions ◽  
Rice Production ◽  
Rice Cultivation ◽  
Resource Saving ◽  
Traditional Methods ◽  
The World ◽  
New Generation

The world practice of rice cultivation has shown that rice cultivation by traditional methods for Russia is labor-intensive, resource-intensive, ineffective with low profitability, and often unprofitable production. As a result, traditional methods of flooding rice paddies in Russia are faced with a shortage and high cost of irrigation water and a reduction in rice irrigation systems, i.e., areas suitable for rice cultivation. For solving the problem of unprofitable rice production, an analysis of the world practice of rice production has been implemented. The analysis showed that the most optimal solution for the natural and climatic conditions of the Krasnodar Territory is the cultivation of rice using sprinkler irrigation and drip irrigation. Further analysis showed that drip irrigation is the most promising way of growing rice, which has many undeniable advantages. The main advantages of drip irrigation are the low irrigation rate, labor intensity, and energy intensity of rice production. Therefore, the article proposes a pioneering Russian ridge cultivation method for rice cultivation on the lands of the irrigated rice fund with drip irrigation under plastic and/or biodegradable perforated film. This method will make it possible to radically revise the principles of rice cultivation, form a new generation of rice crop rotations with the inclusion of melons and vegetables in them, and carry out rice production on previously rainfed lands. The implementation of the method has proven the effectiveness and feasibility of our research.

scholarly journals Energy Efficiency of Novel Interior Surface Layer with Improved Thermal Characteristics and Its Effect on Hygrothermal Performance of Contemporary Building Envelopes

Energies ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 2012 ◽  
Author(s):  
Jan Fořt ◽  
Jiří Šál ◽  
Jan Kočí ◽  
Robert Černý
Keyword(s):  
Energy Consumption ◽  
Energy Savings ◽  
Computational Simulation ◽  
Thermal Characteristics ◽  
Energy Performance ◽  
Climatic Conditions ◽  
Heat Fluxes ◽  
Passive Cooling ◽  
Fuel Price ◽  
Climate Conditions

Facing the consequences of climate change and fuel price rises, the achievement of the requirements for low-energy consumption of buildings has become a challenging issue. On top of that, increased demands on indoor hygrothermal conditions usually require the utilization of additional heating, ventilation, and air-conditioning (HVAC) systems to maintain a comfortable environment. On this account, several advanced and modern materials are widely investigated as a promising way for reduction of the buildings’ energy consumption including utilization of passive heating/cooling energy. However, the efficiency and suitability of passive strategies depending on several aspects including the influence of location, exterior climatic conditions, load-bearing materials used, and insulation materials applied. The main objective of this study consists of the investigation of the energy performance benefits gained by the utilization of advanced materials in plasters by computational modeling. Results obtained from a computational simulation reveal the capability of the studied passive cooling/heating methods on the moderation of indoor air quality together with the reduction of the diurnal temperature fluctuation. Achieved results disclose differences in terms of energy savings for even small variation in outdoor climate conditions. Additionally, the effectivity of passive cooling/heating alters considerably during the summer and winter periods. Based on the analysis of simulated heat fluxes, the potential energy savings related to improved thermal properties of the applied plaster layer reached up to 12.08% and thus represent an interesting passive solution towards energy sustainability to meet the criteria on modern buildings.

A novel modeling and simulation approach for the prediction of human thermophysiological comfort

2020 ◽  
pp. 004051752095522
Author(s):  
Muhammad Awais ◽  
Sybille Krzywinski ◽  
Ellen Wendt
Keyword(s):  
Human Body ◽  
Mechanical Characteristics ◽  
Empirical Process ◽  
Thermal Characteristics ◽  
Climatic Conditions ◽  
Simulation Approach ◽  
Climatic Chamber ◽  
Textile Materials ◽  
Wear Comfort ◽  
Physical And Mechanical Characteristics

Thermophysiological comfort is one of the most important aspects of wear comfort. Currently, there are no software solutions available for the combined consideration of material physical and mechanical characteristics, fit, and thermophysiological behavior. Thus, a laborious empirical process is typically required to determine an appropriate design matching new textile materials to pattern cuts as well as changing climatic conditions. A detailed wear trial in a climatic chamber supports this process. The objective of this research is to analyze the thermal comfort of clothing with different thermal characteristics through the simulation of heat regulation in the human body, microclimate, clothing, and environment.

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