Short Wavelength Solar Radiation Research Articles

Explaining deep learning models for ozone pollution prediction via embedded feature selection

Ambient air pollution is a pervasive global issue that poses significant health risks. Among pollutants, ozone (O3) is responsible for an estimated 1 to 1.2 million premature deaths yearly. Furthermore, O3 adversely affects climate warming, crop productivity, and more. Its formation occurs when nitrogen oxides and volatile organic compounds react with short-wavelength solar radiation. Consequently, urban areas with high traffic volume and elevated temperatures are particularly prone to elevated O3 levels, which pose a significant health risk to their inhabitants. In response to this problem, many countries have developed web and mobile applications that provide real-time air pollution information using sensor data. However, while these applications offer valuable insight into current pollution levels, predicting future pollutant behavior is crucial for effective planning and mitigation strategies. Therefore, our main objectives are to develop accurate and efficient prediction models and identify the key factors that influence O3 levels. We adopt a time series forecasting approach to address these objectives, which allows us to analyze and predict future O3 behavior. Additionally, we tackle the feature selection problem to identify the most relevant features and periods that contribute to prediction accuracy by introducing a novel method called the Time Selection Layer in Deep Learning models, which significantly improves model performance, reduces complexity, and enhances interpretability. Our study focuses on data collected from five representative areas in Seville, Cordova, and Jaen provinces in Spain, using multiple sensors to capture comprehensive pollution data. We compare the performance of three models: Lasso, Decision Tree, and Deep Learning with and without incorporating the Time Selection Layer. Our results demonstrate that including the Time Selection Layer significantly enhances the effectiveness and interpretability of Deep Learning models, achieving an average effectiveness improvement of 9% across all monitored areas.

Cultivation of Organics in Controlled Environment Greenhouse

A greenhouse is essentially an enclosed structure, which traps the short wavelength solar radiation and stores the long wavelength thermal radiation to create a favourable microclimate for higher productivity. The sun’s radiation incident on the greenhouse has two parts: direct radiation and an associated diffuse sky radiation. The diffuse part is not focused by the lenses and goes right through Frensel lenses onto the surface of the absorbers. This energy is absorbed and transformed into heat, which is then transported via the liquid medium in copper pipes to the water (heat) storage tanks or, if used, open fish tanks. In this way, an optimal temperature for both plant cultivation and fish production can be maintained. Stable plant growth conditions are light, temperature and air humidity. Light for the photosynthesis of plants comes from the diffuse radiation, which is without substantial fluctuations and variation throughout most of the day. The air temperature inside the greenhouse is one of the factors that have an influence on the precocity of production. The selective collector acts in a more perceptible way on extreme air temperatures inside the greenhouse. Hence, the system makes it possible to avoid the excessive deviation of the temperature inside the greenhouse and provides a favourable microclimate for the precocity of the culture. Sediment and some associated water from the sediment traps are used as organic fertiliser for the plant cultivation. The present trend in greenhouse cultivation is to extend the crop production season in order to maximise use of the equipment and increase annual productivity and profitability. However, in many Mediterranean greenhouses, such practices are limited because the improper cooling methods (mainly natural or forced ventilation) used do not provide the desired micro-climatic condition during the summer of a composite climate. Also, some of these greenhouses have been built where the meteorological conditions require some heating during the winter, particularly at night. The worst scenario is during the winter months when relatively large difference in temperature between day and night occurs. However, overheating of the greenhouse during the day is common, even in winter, requiring ventilation of the structure. Hence, several techniques have been proposed for the storage of the solar energy received by the greenhouse during the day and its use to heat the structure at night. Reviews of such techniques are presented in this article. Air or water can be used for heat transport. The circulating water is heated during the day via two processes. The water absorbs part of the infrared radiation of the solar spectrum. Since the water is transparent in the visible region, they do not compete with the plants that need it. Alternatively, the water exchanges heat with the greenhouse air through the walls. At night, if the greenhouse temperature goes down below a specified value, the water begins to circulate acting as heat transfer surfaces heating the air in the greenhouse.

The Influence of Environmental Stimuli upon the Human Body in Summer

Green building practices benefit many users because it imposes less of a burden both on people and the environment and plays a central role in achieving a sustainable lifestyle. Covering rooftops with tall evergreen trees increases evaporation and reduces energy consumption by heating and air conditioning systems. Japan has a cereal-crop culinary culture and rice cultivation is a primary activity. According to the Biophilia Hypothesis exposure to a lush greenery environment conducive to survival facilitates more effective relaxation and recovery from fatigue than simple elimination of stress. The impact of rice paddies is not only about reduction of energy consumption, but also about mitigating the urban environment and its physiological and psychological effects on the human body. Focusing on the spread of the rice canopy and exposure of water surfaces, clarified the reaction of the human body to thermal sensory perception and outdoor thermal environments, and the correlation between them. Rice fields where the rice canopy was smaller, and where ample standing water surfaces received short wavelength solar radiation, have a high heat capacity, which works to increase the longwave length thermal radiation in the time period when the accumulated amount of short wavelength solar radiation increases. Meanwhile, where the spread of the rice canopy was greater, and the surface of the standing irrigation water covered with rice plants, a mitigation effect on the outdoor thermal environment evaluation index of ETFe (enhanced conduction-corrected modified effective temperature) through reduction of long wavelength thermal radiation came into play, and it became clear that thermal sensory perception improved through visual stimuli that engendered images of humidity. The purpose of this study was to clarify the environmental mitigation effect of rice fields in an urban environment. In addition to the physical environmental mitigation effect, it was also shown that rice fields engendered a psychological environmental mitigation effect through visual stimuli in the form of natural ground surfaces such as green spaces.

Effects of Outdoor Thermal Environment upon the Human Responses

In a summer outdoor space, the influence of short-wave length solar radiation on the human body is strongly apparent, heat is retained in the body, and the risk of heat disorders such as heat stroke increases. To avoid this, it is essential to seek shade to avoid the influence of short-wave length solar radiation. In addition, natural ground surfaces such as green spaces and water surfaces are useful in reducing the air temperature. It is indispensable to consider climate mitigation effect of outdoor space. The purpose of this study is to clarify the influence of the thermal environment of an outdoor space on the human body in rural and suburban regions where paddy fields remain. Subject experiments were conducted to examine the relationship between the thermal environment evaluation index enhanced conduction-corrected modified effective temperature (ETFe) in an outdoor space and the physiological and psychological responses of the human body. Experiment sites were selected with consideration for the natural ground surface such as bare ground where the surface is gravel or soil; paved ground such as concrete, asphalt or blocks; green areas covered in plants; and water surfaces, as well as the sky factor due to buildings or trees etc. and the proportion of the solid angle of components of greenery and water etc. comprising the solid angle of the total celestial sphere. A ground surface feature with a high heat capacity may promote sensation of hot and deteriorate the thermal sensation. A landscape of thick vegetation with a high green factor may have a strong feeling of confinement, which can make it somewhat hot and somewhat uncomfortable thermal environment due to the sense of stagnation. Compared with the urban environment, it is conceivable that the difference in the perceptual environment, whereby it is subconsciously assumed to be a comfortable thermal environment, had an effect in the rural and suburban regional environment, resulting in an ETFe lower than the upper limit of comfort in a summer urban environment.

Skin Temperature and Body Surface Section in Non-Uniform and Asymmetric Outdoor Thermal Environment

In indoor environments and shady outdoor environments, there is little influence of short-wavelength solar radiation, so a strikingly non-uniform and asymmetric environment is not formed. In outdoor sunny environment, however, shaded areas occur even for the same site of the body, and a remarkable difference in skin temperature is considered to occur under the influence of the short-wavelength solar radiation. The purpose of this study is to clarify the influence of the non-uniform and asymmetric thermal radiation of short-wavelength solar radiation in outdoor environment on the division of the body surface section and the calculation of the mean skin temperature. The skin temperature of the front of the coronal surface, which was facing the sun and where the body received direct short-wavelength solar radiation, and the skin temperature of the rear of the coronal surface, which was in the shadow and did not receive direct short-wavelength solar radiation were respectively measured. The feet, upper arm, forearm, hand and lower leg, which are susceptible to short-wavelength solar radiation in a standing posture, had a noticeable difference in skin temperature between sites in the sun and in shade. The mean skin temperature of sites facing the sun was significantly higher than the mean skin temperature of those in the shade.

The Influence of the Solar Radiation Absorptivity up on the Outdoor Thermal Environment Evaluation Index and the Thermal Sensory Perceptions

When the thermal environment is under heated conditions, short-wavelength solar radiation shows a strong influence on the human body and the heat is accumulated in the human body. In order to demonstrate the effect of the short-wavelength solar radiation absorptivity of clothing on physiological temperature in an outdoor space, the relationship between the thermal environment evaluation index, ETFe, and the thermal sensory perceptions of the human body was investigated. A significant temperature difference of 2.7°C was shown for an ETFe that was thermally neutral (neither hot nor cold). The effect of short-wavelength solar radiation absorptivity was strongly apparent in ETFe when direct solar radiation was strong and in warmer outdoor spaces. In an outdoor space where the effect of the sky factor and albedo was strong, the setting of the short-wavelength solar radiation absorptivity was demonstrated to greatly impact the estimation of perceived and physiological temperature. When interviewing subjects on clothing in an outdoor space, it is essential to obtain the hue of clothing.

Highly efficient luminescent solar concentrators employing commercially available luminescent phosphors

Luminescent solar concentrators (LSC) have great potential for providing solar energy at a competitive cost. They are simple devices employing a luminescent material embedded in a transparent sheet with solar cells attached on the edges. The luminescent material absorbs short wavelength solar radiation and emits red-shifted light. The emission is then guided towards the sheet edges, where the concentrated light is absorbed by the solar cell to produce electricity. The commercialization of luminescent solar concentrators has been stunted by an ongoing search for an adequate luminescent species that, among other things, is UV stable and inexpensive. While luminescent phosphors exhibit these characteristics, as well as other desirable qualities, their use in LSCs has received limited attention because they are highly scattering. Here, we demonstrate that luminescent solar concentrators can effectively employ scattering luminescent phosphors in the form of films. Monte Carlo simulations are used to investigate the optimum film location (top or bottom of the LSC) and concentration of phosphor within the film. The results show that when a film with a high phosphor concentration is placed at the bottom of the LSC, escape cone losses are lower than when the film is placed at the top, which increases light concentration within LSC. Four LSCs fabricated with commercially available materials, including the luminescent phosphor, are tested at varying incident angles using a full spectrum solar simulator. Moderate flux gains are achieved with efficiencies ranging from ~1.6 to 8.6%, depending on the angle of incidence and aspect ratio (AR). These results demonstrate the potential of luminescent phosphors for LSC applications.

Comparison of in-situ and satellite data of surface incoming short-wavelength radiation for the Atlantic Ocean during 2004–2014

Information about short-wavelength (from 0.2 to 4 μm) heat radiation fluxes incoming to the ocean surface is available from very few observations collected by shipboard equipment and buoys and obtained from satellite data archives. Presently, the most complete archive on short-wavelength radiation fluxes is provided by geostationary Earth-orbiting satellites, such as 1G and 2G МETEOSAT (European Union), GOES (United States) and HIMAWARI (Japan), which are equipped with scanners operating in the visible and infrared (IR) ranges, which can image the Earth’s disk every 0.5 h. Additionally, the European EPS/MetOP satellites and US NOAA satellites circulating in mid-altitude circumpolar Sun-synchronous orbits and carrying AVHRR radiometers [1] can be used to obtain daily and monthly average values of incoming short-wavelength solar radiation fluxes. In the future, radiation heat flux data measured by satellites will undoubtedly play a leading role; however, today, the available data record spans only the last few decades, still lacking accuracy and consequently requiring thorough validation.

Sustainable Food Production in Greenhouses and its Relations to the Environment

A greenhouse is essentially an enclosed structure, which traps the short wavelength solar radiation and stores the long wavelength thermal radiation to create a favourable microclimate for higher productivity. The sun’s radiation incident on the greenhouse has two parts: direct radiation and an associated diffuse sky radiation. The diffuse part is not focused by the lenses and goes right through Frensel lenses onto the surface of the absorbers. This energy is absorbed and transformed into heat, which is then transported via the liquid medium in copper pipes to the water (heat) storage tanks or, if used, open fish tanks. In this way, an optimal temperature for both plant cultivation and fish production can be maintained. Stable plant growth conditions are light, temperature and air humidity. Light for the photosynthesis of plants comes from the diffuse radiation, which is without substantial fluctuations and variation throughout most of the day. The air temperature inside the greenhouse is one of the factors that have an influence on the precocity of production. The selective collector acts in a more perceptible way on extreme air temperatures inside the greenhouse. Hence, the system makes it possible to avoid the excessive deviation of the temperature inside the greenhouse and provides a favourable microclimate for the precocity of the culture. Sediment and some associated water from the sediment traps are used as organic fertiliser for the plant cultivation. The present trend in greenhouse cultivation is to extend the crop production season in order to maximise use of the equipment and increase annual productivity and profitability. However, in many Mediterranean greenhouses, such practices are limited because the improper cooling methods (mainly natural or forced ventilation) used do not provide the desired micro-climatic condition during the summer of a composite climate. Also, some of these greenhouses have been built where the meteorological conditions require some heating during the winter, particularly at night. The worst scenario is during the winter months when relatively large difference in temperature between day and night occurs. However, overheating of the greenhouse during the day is common, even in winter, requiring ventilation of the structure. Hence, several techniques have been proposed for the storage of the solar energy received by the greenhouse during the day and its use to heat the structure at night. Reviews of such techniques are presented in this paper. Air or water can be used for heat transport. The circulating water is heated during the day via two processes. The water absorbs part of the infrared radiation of the solar spectrum. Since the water is transparent in the visible region, they do not compete with the plants that need it. Alternatively, the water exchanges heat with the greenhouse air through the walls. At night, if the greenhouse temperature goes down below a specified value, the water begins to circulate acting as heat transfer surfaces heating the air in the greenhouse. This communication describes various designs of low energy greenhouses. It also, outlines the effect of dense urban building nature on energy consumption, and its contribution to climate change. The objectives are to produce vegetables in greenhouse environment. Measures, which would help to save energy in greenhouses, are also presented. It also enabled the minimisation of temperature variation and, hence avoided the hazard of any sudden climatic change inside the greenhouse.

Sustainable Food Production in Greenhouses and Its Relations to the Environment

A greenhouse is essentially an enclosed structure, which traps the short wavelength solar radiation and stores the long wavelength thermal radiation to create a favourable microclimate for higher productivity. The sun's radiation incident on the greenhouse has two parts: direct radiation and an associated diffuse sky radiation. The diffuse part is not focused by the lenses and goes right through Frensel lenses onto the surface of the absorbers. This energy is absorbed and transformed into heat, which is then transported via the liquid medium in copper pipes to the water (heat) storage tanks or, if used, open fish tanks. In this way, an optimal temperature for both plant cultivation and fish production can be maintained. Stable plant growth conditions are light, temperature and air humidity. Light for the photosynthesis of plants comes from the diffuse radiation, which is without substantial fluctuations and variation throughout most of the day. The air temperature inside the greenhouse is one of the factors that have an influence on the precocity of production. The selective collector acts in a more perceptible way on extreme air temperatures inside the greenhouse. Hence, the system makes it possible to avoid the excessive deviation of the temperature inside the greenhouse and provides a favourable microclimate for the precocity of the culture. Sediment and some associated water from the sediment traps are used as organic fertiliser for the plant cultivation. The present trend in greenhouse cultivation is to extend the crop production season in order to maximise use of the equipment and increase annual productivity and profitability. However, in many Mediterranean greenhouses, such practices are limited because the improper cooling methods (mainly natural or forced ventilation) used do not provide the desired micro-climatic condition during the summer of a composite climate. Also, some of these greenhouses have been built where the meteorological conditions require some heating during the winter, particularly at night. The worst scenario is during the winter months when relatively large difference in temperature between day and night occurs. However, overheating of the greenhouse during the day is common, even in winter, requiring ventilation of the structure. Hence, several techniques have been proposed for the storage of the solar energy received by the greenhouse during the day and its use to heat the structure at night. Reviews of such techniques are presented in this paper. Air or water can be used for heat transport. The circulating water is heated during the day via two processes. The water absorbs part of the infrared radiation of the solar spectrum. Since the water is transparent in the visible region, they do not compete with the plants that need it. Alternatively, the water exchanges heat with the greenhouse air through the walls. At night, if the greenhouse temperature goes down below a specified value, the water begins to circulate acting as heat transfer surfaces heating the air in the greenhouse. This communication describes various designs of low energy greenhouses. It also, outlines the effect of dense urban building nature on energy consumption, and its contribution to climate change. The objectives are to produce vegetables in greenhouse environment. Measures, which would help to save energy in greenhouses, are also presented. It also enabled the minimisation of temperature variation and, hence avoided the hazard of any sudden climatic change inside the greenhouse.

Comparison of selective transmitters for solar thermal applications.

Solar thermal collectors are radiative heat exchangers. Their efficacy is dictated predominantly by their absorption of short wavelength solar radiation and, importantly, by their emission of long wavelength thermal radiation. In conventional collector designs, the receiver is coated with a selectively absorbing surface (Black Chrome, TiNOx, etc.), which serves both of these aims. As the leading commercial absorber, TiNOx consists of several thin, vapor deposited layers (of metals and ceramics) on a metal substrate. In this technology, the solar absorption to thermal emission ratio can exceed 20. If a solar system requires an analogous transparent component-one which transmits the full AM1.5 solar spectrum, but reflects long wavelength thermal emission-the technology is much less developed. Bespoke "heat mirrors" are available from optics suppliers at high cost, but the closest mass-produced commercial technology is low-e glass. Low-e glasses are designed for visible light transmission and, as such, they reflect up to 50% of available solar energy. To address this technical gap, this study investigated selected combinations of thin films that could be deposited to serve as transparent, selective solar covers. A comparative numerical analysis of feasible materials and configurations was investigated using a nondimensional metric termed the efficiency factor for selectivity (EFS). This metric is dependent on the operation temperature and solar concentration ratio of the system, so our analysis covered the practical range for these parameters. It was found that thin films of indium tin oxide (ITO) and ZnS-Ag-ZnS provided the highest EFS. Of these, ITO represents the more commercially viable solution for large-scale development. Based on these optimized designs, proof-of-concept ITO depositions were fabricated and compared to commercial depositions. Overall, this study presents a systematic guide for creating a new class of selective, transparent optics for solar thermal collectors.

Greenhouses for Food Production and the Environment

A greenhouse is essentially an enclosed structure, which traps the short wavelength solar radiation and stores the long wavelength thermal radiation to create a favorable microclimate for higher productivity. The sun’s radiation incident on the greenhouse has two parts: direct radiation and an associated diffuse sky radiation. The diffuse part is not focused by the lenses and goes right through Frensel lenses onto the surface of the absorbers. This energy is absorbed and transformed into heat, which is then transported via the liquid medium in copper pipes to the water (heat) storage tanks or, if used, open fish tanks. In this way, an optimal temperature for both plant cultivation and fish production can be maintained. Stable plant growth conditions are light, temperature and air humidity. Light for the photosynthesis of plants comes from the diffuse radiation, which is without substantial fluctuations and variation throughout most of the day. The air temperature inside the greenhouse is one of the factors that have an influence on the precocity of production. The selective collector acts in a more perceptible way on extreme air temperatures inside the greenhouse. Hence, the system makes it possible to avoid the excessive deviation of the temperature inside the greenhouse and provides a favorable microclimate for the precocity of the culture. Sediment and some associated water from the sediment traps are used as organic fertilizer for the plant cultivation. The present trend in greenhouse cultivation is to extend the crop production season in order to maximize use of the equipment and increase annual productivity and profitability. However, in many Mediterranean greenhouses, such practices are limited because the improper cooling methods (mainly natural or forced ventilation) used do not provide the desired micro-climatic condition during the summer of a composite climate. Also, some of these greenhouses have been built where the meteorological conditions require some heating during the winter, particularly at night. The worst scenario is during the winter months when relatively large difference in temperature between day and night occurs. However, overheating of the greenhouse during the day is common, even in winter, requiring ventilation of the structure. Hence, several techniques have been proposed for the storage of the solar energy received by the greenhouse during the day and its use to heat the structure at night. Reviews of such techniques are presented in this chapter. Air or water can be used for heat transport. The circulating water is heated during the day via two processes. The water absorbs part of the infrared radiation of the solar spectrum. Since the water is transparent in the visible region, they do not compete with the plants that need it. Alternatively, the water exchanges heat with the greenhouse air through the walls. At night, if the greenhouse temperature goes down below a specified value, the water begins to circulate acting as heat transfer surfaces heating the air in the greenhouse. This chapter describes various designs of low energy greenhouses. It also, outlines the effect of dense urban building nature on energy consumption, and its contribution to climate change. Measures, which would help to save energy in greenhouses, are also presented. It also enabled the minimization of temperature variation and, hence avoided the hazard of any sudden climatic change inside the greenhouse.

The Planetary and Space Simulation Facilities at DLR Cologne

Astrobiology strives to increase our knowledge on the origin, evolution and distribution of life, on Earth and beyond. In the past centuries, life has been found on Earth in environments with extreme conditions that were expected to be uninhabitable. Scientific investigations of the underlying metabolic mechanisms and strategies that lead to the high adaptability of these extremophile organisms increase our understanding of evolution and distribution of life on Earth. Life as we know it depends on the availability of liquid water. Exposure of organisms to defined and complex extreme environmental conditions, in particular those that limit the water availability, allows the investigation of the survival mechanisms as well as an estimation of the possibility of the distribution to and survivability on other celestial bodies of selected organisms. Space missions in low Earth orbit (LEO) provide access for experiments to complex environmental conditions not available on Earth, but studies on the molecular and cellular mechanisms of adaption to these hostile conditions and on the limits of life cannot be performed exclusively in space experiments. Experimental space is limited and allows only the investigation of selected endpoints. An additional intensive ground based program is required, with easy to access facilities capable to simulate space and planetary environments, in particular with focus on temperature, pressure, atmospheric composition and short wavelength solar ultraviolet radiation (UV). DLR Cologne operates a number of Planetary and Space Simulation facilities (PSI) where microorganisms from extreme terrestrial environments or known for their high adaptability are exposed for mechanistic studies. Space or planetary parameters are simulated individually or in combination in temperature controlled vacuum facilities equipped with a variety of defined and calibrated irradiation sources. The PSI support basic research and were recurrently used for pre-flight test programs for several astrobiological space missions. Parallel experiments on ground provided essential complementary data supporting the scientific interpretation of the data received from the space missions.

Wide spectrum solar energy harvesting through an integrated photovoltaic and thermoelectric system

This paper proposes a power system concept that integrates photovoltaic (PV) and thermoelectric (TE) technologies to harvest solar energy from a wide spectral range. By introduction of the ‘spectrum beam splitting’ technique, short wavelength solar radiation is converted directly into electricity in the PV cells, while the long wavelength segment of the spectrum is used to produce moderate to high temperature thermal energy, which then generates electricity in the TE device. To overcome the intermittent nature of solar radiation, the system is also coupled to a thermal energy storage unit. A systematic analysis of the integrated system is carried out, encompassing the system configuration, material properties, thermal management, and energy storage aspects. We have also attempted to optimize the integrated system. The results indicate that the system configuration and optimization are the most important factors for high overall efficiency.

New luminescent glasses and prospects of using them in solar energy

This paper presents a comparative analysis of the luminescence and absorption of glasses with molecular clusters of silver and selenium and nanocrystals of copper chloride and cadmium sulfide from the viewpoint of spectral down-conversion of short-wavelength solar radiation into the spectral interval of the maximum efficiency of the photoelectric converter of a solar cell. It is shown that UV and violet radiation can be efficiently converted into the 450–700-nm spectral region by appropriately choosing the luminescence centers in glass, and this promises to reduce the number of stages in a solar cell.

Does Enhanced Solar UV‐B Radiation Affect Marine Primary Producers in Their Natural Habitats?

This article is a highlight of the paper by Li et al. in this issue of Photochemistry and Photobiology as well as a short summary of the research on the effects of solar UV-B radiation on primary production in the oceans. Laboratory experiments under controlled conditions using artificial light sources indicate species-specific damage of many phytoplankton groups. Mesocosm studies in enclosures of limited volume allow analyzing UV effects in multigeneration monitoring of natural assemblages. Field studies to determine the effects of short-wavelength solar radiation require sensitive instrumentation and measurements over extended areas of the open ocean to yield significant results. Results from a cruise described in the paper by Li et al. indicate clear effects of UV-B and UV-A on the photosynthetic carbon fixation of phytoplankton communities with spatial differences between coastal and open-ocean waters. Increasing temperatures and acidification in the ocean due to global climate change may exacerbate the detrimental effects of solar UV-B radiation.

FROZEN HYDROCARBONS IN COMETS

Recent investigations of the luminescence of frozen hydrocarbon particles of icy cometary halos have been carried out. The process of luminescence of organic icy particles in a short-wavelength solar radiation field is considered. A comparative analysis of observed and laboratory data leads to 72 luminescent emission lines in the spectrum of the comet 153P/Ikeya-Zhang. The concept of cometary relict matter is presented, and the creation of a database of unidentified cometary emission lines is proposed.

Organic component of cometary ice

Investigations of the luminescence of frozen hydrocarbon particles of icy cometary halo have been made. The process of luminescence of icy particles in shortwavelength solar radiation field is considered. The comparative analysis of observed and laboratory data leads of 72 luminescent emission lines in the spectrum of 153P/Ikeya-Zhang comet. Several aspects of the problem are discussed.

Constructions, applications and the environment of greenhouses

A greenhouse is essentially an enclosed structure, which traps the short wavelength solar radiation and stores the long wavelength thermal radiation to create a favourable microclimate for higher productivity. The sun’s radiation incident on the greenhouse has two parts: direct radiation and an associated diffuse sky radiation. The diffuse part is not focused by the lenses and goes right through Frensel lenses onto the surface of the absorbers. This energy is absorbed and transformed into heat, which is then transported via the liquid medium in copper pipes to the water (heat) storage tanks or, if used, open fish tanks. In this way, an optimal temperature for both plant cultivation and fish production can be maintained. Stable plant growth conditions are light, temperature and air humidity. Light for the photosynthesis of plants comes from the diffuse radiation, which is without substantial fluctuations and variation throughout most of the day. The air temperature inside the greenhouse is one of the factors that have an influence on the precocity of production. The selective collector acts in a more perceptible way on extreme air temperatures inside the greenhouse. Hence, the system makes it possible to avoid the excessive deviation of the temperature inside the greenhouse and provides a favourable microclimate for the precocity of the culture. Sediment and some associated water from the sediment traps are used as organic fertiliser for the plant cultivation. The present trend in greenhouse cultivation is to extend the crop production season in order to maximise use of the equipment and increase annual productivity and profitability. However, in many Mediterranean greenhouses, such practices are limited because the improper cooling methods (mainly natural or forced ventilation) used do not provide the desired micro-climatic condition during the summer of a composite climate. Also, some of these greenhouses have been built where the meteorological conditions require some heating during the winter, particularly at night. The worst scenario is during the winter months when relatively large difference in temperature between day and night occurs. However, overheating of the greenhouse during the day is common, even in winter, requiring ventilation of the structure. Hence, several techniques have been proposed for the storage of the solar energy received by the greenhouse during the day and its use to heat the structure at night. Reviews of such techniques are presented in this article. Air or water can be used for heat transport. The circulating water is heated during the day via two processes. The water absorbs part of the infrared radiation of the solar spectrum. Since the water is transparent in the visible region, they do not compete with the plants that need it. Alternatively, the water exchanges heat with the greenhouse air through the walls. At night, if the greenhouse temperature goes down below a specified value, the water begins to circulate acting as heat transfer surfaces heating the air in the greenhouse. This article describes various designs of low energy greenhouses. It also, outlines the effect of dense urban building nature on energy consumption, and its contribution to climate change. Measures, which would help to save energy in greenhouses, are also presented. It also enabled the minimisation of temperature variation and, hence avoided the hazard of any sudden climatic change inside the greenhouse.

The contribution of this country's scientists to research on the ionosphere and solar-terrestrial relationships

This paper analyzes the achievements of our country's scientists in heliogeophysical studies in the period after the first International Geophysical Year (1957-58), the experience of which was taken into account in organizing and carrying out an array of projects in solar-terrestrial physics. The use of the first geophysical rockets and later of scientific satellites in the study of the ionosphere showed that fundamental improvements were needed in the theory of the formation of the ionosphere. It was necessary to construct de novo empirical and theoretical models of the spectra and fluxes of short-wavelength solar radiation from the x-ray to the UV range. To do this, a model of the sun's upper atmosphere was created in which the main role belongs to the transitional region between the chromosphere and the corona. © 2005 Optical Society of America