scholarly journals The Semitransparent Photovoltaic Films for Mediterranean Greenhouse: A New Sustainable Technology

2012 ◽  
Vol 2012 ◽  
pp. 1-14 ◽  
Author(s):  
Alvaro Marucci ◽  
Danilo Monarca ◽  
Massimo Cecchini ◽  
Andrea Colantoni ◽  
Alberto Manzo ◽  
...  

Mediterranean countries offer very favorable climatic conditions for growing plants in a protected environment: as a matter of fact, the high solar radiation allows the use of greenhouses with simple structures, covered with plastic film and without fixed installations for winter heating. They are called “Mediterranean greenhouses” and are totally different from those in Central and Northern Europe. In the photovoltaic greenhouses, the cover on the pitch facing south is usually replaced by very opaque panels. However, this solution compromises the possibility to grow plants in covered and protected environments since solar radiation availability is limited and strongly nonuniform. In order to overcome this problem, semitransparent photovoltaic materials can be used to let the solar energy, necessary for plant growth, pass into the green house. The aim of this research is to analyze the radiometric properties of innovative semitransparent flexible photovoltaic materials in order to evaluate their performances in comparison with materials commonly used in the coverage of the greenhouses. Particular attention is paid to the transmittance of these materials in the visible range and in the long wave infrared for the achievement of greenhouse effect.

2018 ◽  
Vol 63 (1) ◽  
pp. 57-66
Author(s):  
Balázs Bokor ◽  
Hacer Akhan ◽  
Dogan Eryener ◽  
László Kajtár

Transpired solar collector (TSC) systems are simple solutions for the preheating of ventilation air with solar energy. Their performance is a function of several environmental factors, so the climatic conditions of the location play an important role. In this paper, the effect of different climatic zones on the thermal performance of the TSC is investigated. To exclude other sources of influence, the same reference industrial building is examined in four Turkish locations (Antalya, Istanbul, Ankara and Sivas) representing different climatic conditions. RETScreen simulation is carried out for all four regions to obtain the drop of conventional heating requirement in case absorber azimuth of 0°, 45° and 90°. To illustrate the performance, temperature rise, heating energy savings and annual solar fraction are presented. Generally, it can be stated that a location with cold climate and high solar radiation at the same time benefits most from the use of a TSC system. A mathematical correlation has been found showing the solar fraction's dependence on solar radiation and heating degree days. Finally, simulation results have been compared to a set of measurement data from an industrial building's TSC system near Istanbul.


2019 ◽  
Vol 12 (2) ◽  
pp. 183-190 ◽  
Author(s):  
B. Udovicki ◽  
I. Djekic ◽  
S. Stankovic ◽  
A. Obradovic ◽  
A. Rajkovic

The influence of climatic conditions on the levels of fumonisins in maize grown in Serbia was studied over eight years (2008 to 2015), investigating the possible relationship between the levels of fumonisins contamination in maize in relation to registered weather/climatic conditions. Presence of these mycotoxins in maize after harvest was evaluated based on climatic conditions within two periods: 10 days before and 10 days after 50% silking. Categories of fumonisins levels were transformed into classes. Chi-square test for association was used in analysing relationships between results of fumonisins levels and calendar years. Mann-Whitney U-test was used to compare differences between meteorological data of two subsets in years with high and low fumonisins level. There was a statistically significant association between the fumonisins levels and calendar years χ2=247.954; (P<0.05). This study identified low precipitation and low humidity combined with high solar radiation as a critical parameter combination for elevated levels of fumonisins. The statistically significant difference in relation to some of the examined parameters suggests that maize in Serbian agro-climatic conditions is more susceptible to fungal colonisation, and subsequent fumonisin production in the period of 10 days before 50% silking.


Author(s):  
Kelly Chance ◽  
Randall V. Martin

Global climate is controlled by an energy balance between incoming solar radiation and outgoing terrestrial radiation. An energy balance is first developed using a simple one-layer model of the atmosphere and then made more realistic by distributing the atmospheric optical depth smoothly in a Gray Atmosphere Model. Wavelength-specific and altitude-dependent absorption and emission for the ultraviolet through long-wave infrared are described. Knowledge is combined into an overall Earth energy budget. The sensitivity of the climate to radiative forcing is examined.


2021 ◽  
Vol 99 (Supplement_3) ◽  
pp. 425-426
Author(s):  
Rafael Rodriguez-Martinez ◽  
Jesús Salvador Rivas-Madero ◽  
Pedro Antonio Robles-Trillo ◽  
César A Meza-Herrera ◽  
Rafael Rodriguez-Venegas

Abstract The Lagunera region, located in north central Mexico (24° 01′-26° 48 ‘LN and 101° 52′-101° 52′ 104° 40′ LO), produce the 21% of the national Mexican cow’s milk despite its climatic conditions (temperatures that fluctuate between 12.7 °C in January and 28.5 °C in June, with extremes of -5 °C and 41.5 °C, in addition to high solar radiation). The Temperature Humidity Index (THI) is the most useful indicator to define if there are heat stress conditions. To identify whether the days in which THI ≥68 (considering the threshold for signs of heat stress to appear in high-producing lactating cows) are increasingly reached at least one hour a day, the information of this indicator was recorded every 10 min daily, from 5 cow farms for 6 years (2015–2020), using the DiGiTH™ application (DiGiTH Technologies, Mexico), and regressions were run to identify if there is a relationship between the years of study and the THI levels. At any level of THI (≥68), there is a tendency to increase the number of days (10.05 d per year; R2 0.37); Disaggregating the data by THI level, this trend is also observed for levels 68 to 71 and 72 to 76 THI, registering an increase of 11.33 d (R2 0.45) and 9.03 d per year (R2 0.45) respectively. At the 77 - 79 THI level there is no trend, while at the ≥80 THI level, a decrease of 5.66 d per year was registered (R2 0.79). The results suggest that in this region, the days of heat stress are increasing, except for the level ≥80 THI, which indicates that palliative measures for heat stress should be intensified, and it is necessary to identify the reason for the decrease in heat stress days at the most dangerous level for livestock.


Author(s):  
V. V. Kniaz ◽  
A. N. Bordodymov

<p><strong>Abstract.</strong> Person re-identification (ReID) in color and thermal images require matching of the object color and its temperature. While thermal cameras increase the performance of ReID systems during the night-time, identification of corresponding features in the visible and the long-wave infrared range is challenging. The biggest challenge arises from the multimodal relationship between an object’s color and its temperature. Modern ReID methods provide state-of-the-art results in person matching in the visible range. Hence, it is possible to perform multimodal matching by translation of a thermal probe image to the color domain. After that, the synthetic color probe image is matched with images from the real color gallery set. This paper is focused on the development of the ThermalReID multispectral person ReID framework. The framework performs matching in two steps. Firstly, it colorizes the input thermal probe image using a Generative Adversarial Network (GAN). Secondly, it matches images in the color domain using color histograms and MSCR features. We evaluate the ThermalReID framework using RegDB and ThermalWorld datasets. The results of the evaluation are twofold. Firstly, the developed GAN performs realistic colorization of thermal images. Secondly, the ThermalReID framework provides matching of persons in color and thermal images that compete with and surpass the state-of-the-art. The developed ThermalReID framework can be used in video surveillance systems for effective person ReID during the nighttime.</p>


Author(s):  
Andrew T. Hudak ◽  
Benjamin C. Bright ◽  
Robert L. Kremens ◽  
Matthew B. Dickinson ◽  
Matthew G. Alden

Sensors ◽  
2021 ◽  
Vol 21 (11) ◽  
pp. 3690
Author(s):  
Denis Dufour ◽  
Loïc Le Noc ◽  
Bruno Tremblay ◽  
Mathieu N. Tremblay ◽  
Francis Généreux ◽  
...  

This study describes the development of a prototype bi-spectral microbolometer sensor system designed explicitly for radiometric measurement and characterization of wildfire mid- and long-wave infrared radiances. The system is tested experimentally over moderate-scale experimental burns coincident with FLIR reference imagery. Statistical comparison of the fire radiative power (FRP; W) retrievals suggest that this novel system is highly reliable for use in collecting radiometric measurements of biomass burning. As such, this study provides clear experimental evidence that mid-wave infrared microbolometers are capable of collecting FRP measurements. Furthermore, given the low resource nature of this detector type, it presents a suitable option for monitoring wildfire behaviour from low resource platforms such as unmanned aerial vehicles (UAVs) or nanosats.


2020 ◽  
pp. 1-1
Author(s):  
Zhijian Shen ◽  
Zhuo Deng ◽  
Xuyi Zhao ◽  
Jian Huang ◽  
Lu Yao ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document