Winter Solstice Research Articles

Drift analysis in tilt-roll heliostats

Drift is a relevant issue in concentrated solar tower facilities since this time-dependent pointing error severely affects their performance. This work deals with the optical analysis of drift for tilt-roll heliostats in terms of the geometrical parameters associated to the heliostat mechanical structure and the local time. For each drift source or error, flux maps have been obtained by means of Monte Carlo ray-tracing calculations as a function of the source magnitude and daily time in winter and summer solstices. Then the corresponding pointing errors and the drift curves are determined from the displacement of the center of gravity of the flux maps. As a result, drift related to each source is identified and characterized. Additionally, drift sources are compared in terms of the standard deviation and the mean of their daily pointing errors. The analysis evidences that main drift sources are the misalignments of the pedestal like the one of an inclination with respect to the zenith.

Baroclinic waves in the northern hemisphere of Mars as observed by the MRO Mars Climate Sounder and the MGS Thermal Emission Spectrometer

The climatology of baroclinic waves in the northern hemisphere of Mars is investigated through analysis of observations by the infrared sounders on Mars Reconnaissance Orbiter (MRO) and Mars Global Surveyor (MGS). We focus on the lowest scale height above the surface, where the waves have a large impact on the Martian dust cycle. Profiles retrieved by the MRO Mars Climate Sounder (MCS) rarely reach the lower atmosphere at the season and location of interest. To fill this gap, we turn to observations in the MCS B1 channel (32 μm) when the instrument is viewing the surface. The signature of baroclinic waves appears in these data because of dust-related emission from the lower atmosphere and wave-induced variations of surface temperature. We supplement the MCS data with measurements of temperature at the 610-Pa pressure level from the MGS Thermal Emission Spectrometer (TES). Both data sets provide systematic coverage in latitude and longitude at two local times. Characteristics of baroclinic waves are derived through analysis of observations with a combined duration of about 8 Mars years. Basic results include least-squares solutions for wave amplitude and period at zonal wavenumber 1–3; the resolution is 4∘ in latitude and 14 solar days in time of observation. There is a strong similarity between the baroclinic waves observed by MCS and TES, which confirms the sensitivity of the MCS B1 channel to wave activity at pressures near 610 Pa. In all 8 Mars years, the baroclinic waves exhibit periodic transitions among modes with different zonal wavenumbers and a distinctive solstitial pause. Although the weather in each Mars year is unique in some respects, a composite of results from all years reveals a well-defined wave climatology. At each zonal wavenumber, large amplitudes are restricted to a pair of seasonal windows positioned symmetrically about the winter solstice. The wave-2 mode is strongest in early autumn and near the vernal equinox, whereas wave 3 is the dominant mode in mid-autumn and mid-winter, immediately before and after the solstitial pause. The interaction between baroclinic waves and dust storms is investigated through comparisons with spacecraft measurements of dust opacity. A strong wave-3 mode is often present during the initial growth phase of large, seasonal dust storms, which reflects the importance of wave-generated frontal dust storms in triggering these events. The wave-3 amplitude then decreases rapidly as the dust storm evolves; this occurs routinely in all Mars years considered here in connection with both mid-autumn “A” storms and mid-winter “C” storms. In some years A-storm suppression of the wave-3 mode marks the beginning of the solstitial pause. These results provide a basis for testing and development of Mars General Circulation Models as well as context for interpreting contemporaneous observations, such as spacecraft images of frontal and flushing dust storms.

Off-design thermodynamic performances of a combined solar tower and parabolic trough aided coal-fired power plant

The solar tower and parabolic trough aided coal-fired power generation has been demonstrated as a promising technology and has potential advantages in utilisation of solar energy in a cost-effective manner. Due to introduction of solar energy, from the solar tower or parabolic troughs, increases to a certain extent, the steam temperature would be difficult to maintain and leads to safety concerns. Therefore, the limitation of integrated solar energy, considering the overlapped influence of different solar energy input, needs to be well identified and managed. This work considered a 600 MWe integrated system as an example. Solar energy from parabolic troughs is used in the preheater while energy from the solar tower is used to reheat steam. The novelty of this study is the interaction of different solar energy input in fossil plants and its benefits is revealed for the first time. The maximum absorbed solar energy, considering the mutual effects of introduced solar energy flows, are explored. Then the system performance under three different loads (100%, 75%, 50%) and hourly operational performance in four typical days are analysed. The paper shows that the feed-water extraction results in the enhancement of maximum solar energy absorbed by reheat steam extraction, is improved by 24.2 MWth (28.5%), 11.5 MWth (20.0%), and 5.6 MWth (14.3%) as feed-water extraction percentages increase at the three load conditions. As a result, the minimum standard coal consumption rates are improved by 13.2 g/kWh (5.2%), 10.7 (4.1%) g/kWh and 9.0 g/kWh (3.1%) respectively. In four typical days, the highest coal consumption reduction is reached in the summer solstice, which is 266.6-tonne, 202.8-tonne and 131.4-tonne under three different loads, while the highest coal consumption is obtained in the winter solstice.

A Comparative Study on Daylight Performance Assessment of Light Shelves Based on Inclination

Energy consumption of lighting can be reduced by using different daylight control strategies. The rise in environmental distresses requires the necessity of natural light control systems. Light shelf is considered as excellent lighting control scheme that provides great lighting production and inexpensive prospect via entering the daylight inside the space. The aims of this study shows that the daylight efficiency and visual productivity are affected by the design parameters of light shelf such as its angle, location and height. In this research, Autodesk Ecotect 2011 is used for the daylight simulation of summer solstice and winter solstice days under overcast sky conditions on a nominated theoretical study space of an institutional building. Daylight simulation is carried out to evaluate the illuminance requirement within the selected space and analysis is also executed on the model with selected categories of light shelves including different positions, heights and angles. The acquired data is then exported on Radiance software intended for complete day-light investigation. The results of this research shows that external light shelf at a height of 7' and an angle of 20˚ is the most appropriate choice in prevailing the glare and it also enhanced the illuminance level to11.5% in 21st June and 10.6% in 21st December as compared to without light shelves. Furthermore, the shaded range is decreased by the rise in the angle of Light shelf which has a tendency to increase the inside average lighting. Hence, significant consideration should be given to the height and position of light shelves, since it has a superior effect on light shelf performance.

EVALUATING THE SUN’S POSITION AND TRACKING THE SUN PATH FOR DUTSIN-MA, KATSINA STATE, NIGERIA

Solar energy is the most promising renewable energy source because of its free availability and an environmentally friendly source. The crucial applications of solar energy depend upon determining the precise position of the sun. In this research, we had made an attempt to determine the precise location of the sun for any topographical position of the earth using solar azimuth/altitude reckoner to track the path of the sun and related sun data. For the purpose of this work, we measured the position of Dutsin-Ma in Katsina State, Northwestern part of Nigeria. Solar online calculator (Keisan online calculator) was used to obtain primary data of sun’s (solar) angle parameters in order to calculate a series of variations in the azimuth and altitude angles using some inputs such as latitude, longitude, date, year, time and time zone. The results revealed that the maximum azimuth angles obtained from the sun are 294.38° for the winter solstice and 248.32° for the summer solstice with elevation angles of 79.01° and 53.46° respectively. Furthermore, the highest values of the hour angles were found to be 97.05° and 97.86° for the summer solstice and the winter solstice respectively. The findings of this work will help individual, government, and non-governmental organizations towards the utilization of solar energy and harnessing it especially during the installations of solar panels and other solar devices.

Fire, Prayer, and Purification

Abstract Kyoto is home to a number of unique year-end festivals. This article focuses on traditions that occur during Shimotsuki and Shiwasu (the eleventh and twelfth months of the old Japanese lunisolar calendar), including the fire festivals of O-hitaki, Niinamesai, and Daikondaki; events that celebrate visiting deities, such as Daishikō; and purification rites of Shintō, Buddhist, and folk tradition, such as Kakure nenbutsu, Butsumyōe, and Sekizoro. Analysis and comparison of these rituals reveals a common motivation for their origin. As the power of the sun wanes with the winter solstice, the people of Kyoto in the past felt a need to reflect on the previous year, cleanse themselves of accumulated sin and misfortune, and pray that the coming year would bring peace, fortune, and a fertile harvest.

Effects of a temperature rise on melatonin and thyroid hormones during smoltification of Atlantic salmon, Salmo salar.

Smoltification prepares juvenile Atlantic salmon (Salmo salar) for downstream migration. Dramatic changes characterize this crucial event in the salmon's life cycle, including increased gill Na+/K+-ATPase activity (NKA) and plasma hormone levels. The triggering of smoltification relies on photoperiod and is modulated by temperature. Both provide reliable information, to which fish have adapted for thousands of years, that allows deciphering daily and calendar time. Here we studied the impact of different photoperiod (natural, sustained winter solstice) and temperature (natural, ~ + 4° C) combinations, on gill NKA, plasma free triiodothyronine (T3) and thyroxine (T4), and melatonin (MEL; the time-keeping hormone), throughout smoltification. We also studied the impact of temperature history on pineal gland MEL production in vitro. The spring increase in gill NKA was less pronounced in smolts kept under sustained winter photoperiod and/or elevated temperature. Plasma thyroid hormone levels displayed day-night variations, which were affected by elevated temperature, either independently from photoperiod (decrease in T3 levels) or under natural photoperiod exclusively (increase in T4 nocturnal levels). Nocturnal MEL secretion was potentiated by the elevated temperature, which also altered theMEL profile under sustained winter photoperiod. Temperature also affected pineal MEL production in vitro, a response that depended on previous environmental acclimation of the organ. The results support the view that the salmon pineal is a photoperiod and temperature sensor, highlight the complexity of the interaction of these environmental factors on the endocrine system of S. salar, and indicate that climate change might compromise salmon's time "deciphering" during smoltification, downstream migration and seawater residence.

Ionospheric Planetary Wave Activity and Its Role in Equatorial Spread F Day‐to‐Day Variability

AbstractA comprehensive analysis on the ionospheric planetary wave activity is undertaken using 8 years of ionosonde data at Trivandrum (8.5°N, 77°E), a dip equatorial station. The study reveals that the dominant planetary wave is of 16‐day type and its strength is maximum in winter solstice/autumnal equinox and minimum in summer solstice in high solar activity conditions. In low solar activity years planetary wave activity strength is more or less comparable in vernal equinox, autumnal equinox, and winter solstice, while it is observed to be least in summer solstice. Further, the planetary wave activity shows direct correlation with solar activity for the different seasons. Thermosphere Ionosphere Mesosphere Energetics and Dynamics (TIMED) satellite observations of off‐equatorial E‐region zonal winds confirm the fact that they are strong westward in high solar activity years compared to low solar activity years. The strong westward winds aid the upward propagation of westward propagating planetary waves in high solar activity years. Planetary waves reaching the off‐equatorial E‐region modulate the equatorial F‐region via the coupling along the magnetic field lines. The role of planetary waves in modulating the pre‐reversal enhancement, equatorial spread F duration, and its spread range on a day‐to‐day basis is brought out quantitatively for both high and low solar activity conditions. The study emphasizes the importance of ionospheric planetary wave studies for the prediction of equatorial spread F characteristics.

Light angle dependence of photothermal properties in oxide and porphyrin thin films for energy-efficient window applications

The photothermal experiments on the incident light angle dependence are carried out using simulated solar light on thin films of both iron oxides (Fe3O4 and Fe3O4@Cu2-xS) and porphyrin compounds (chlorophyll and chlorophyllin). Fe3O4 and Fe3O4@Cu2-xS are synthesized using various solution methods that produce mono-dispersed nanoparticles on the order of 10 nm. Chlorophyll is extracted from fresh spinach and chlorophyllin sodium copper is a commercial product. These photothermal (PT) materials are dispersed in polymethyl methacrylate (PMMA) solutions and deposited on glass substrates via spin coating that result in clear and transparent thin films. The iron-oxide based thin films show distinctive absorption spectra; Fe3O4 exhibits a strong peak near UV and gradually decreases into the visible and NIR regions; the absorption of Fe3O4@Cu2-xS is similar in the UV region but shows a broad absorption in the NIR region. Both chlorophyll and chlorophyllin are characterized with absorption peaks near UV and NIR showing a “U”-shaped spectrum, ideally required for efficient solar harvest and high transparency in energy-efficient single-pane window applications. Upon coating of the transparent PT films on the window inner surfaces, solar irradiation induces the photothermal effect, consequently raising the film temperature. In this fashion, the thermal loss through the window can be significantly lowered by reducing the temperature difference between the window inner surface and the room interior, based on a new concept of so-called optical thermal insulation (OTI) without any intervention medium, such as air/argon, as required in the glazing technologies. Single-panes are therefore possible to replace double- or triple panes. As OTI is inevitably affected by seasonal and daily sunlight changes, an incident light angle dependence of the photothermal effect is crucial in both thin film and window designs. It is found that the heating curves reach their maxima at small angles of incidence while the photothermal effect is considerably reduced at large angles. This angle dependence is well explained by light reflection by the thin film surface, however, deviated from what is predicted by the Fresnel's law, attributable to non-ideal surfaces of the substrates. The angle dependence data provide an important reference for OTI that window exposure to the sun is greater at winter solstice while that is considerably reduced in the summer. This conclusion indicates much enhanced solar harvesting and heat conversion via optically insulated windows in the winter season, resulting in much lower U-factors.

고층건물 건설에 따른 주변지역 일조환경 영향평가

In this study, the effect of construction of high-rise buildings on sunshine environment in N-newtown was predicted and analyzed by using a sunshine duration model. Three-dimensional topography and buildings in the target area were numerically constructed, based on the geographic information system(GIS) data. The azimuth and altitude angles of the sun for the target area on spring equinox, summer solstice, autumn equinox and winter solstice in 2019 were calculated as the root mean square errors(RMSE) below 0.4°, compared with the data provided by Korea astronomy and space science institute(KASI). The shadow length formed by the construction of new buildings was predicted as 205 m ~ 270 m(about three times of the building height) for the lower altitude angles of the sun. The gross shadow area for the target area on winter solstice was estimated as the increase rate of 17.5 % by the construction of new buildings. For the apartment complex located adjacent to the north-northwest side of the construction site of new buildings, the gross shadow area on winter solstice was estimated as the increase rate of 87.6 %(intensive damage) by the construction of new buildings. The results indicated that the assessment of sunshine environment should be necessary for new construction of high-rise buildings.

High-Luminance Mid-Air Image Display for Outdoor Viewing by Focusing Sunlight

The mid-air image is a very powerful method for presenting computer graphics in a real environment, but it cannot be used in bright locations owing to the decrease in brightness during the imaging process. Therefore, to form a mid-air image with a high-brightness light source, a square pyramidal mirror structure was investigated, and the sunlight concentration was simulated. We simulated the tilt angle and combination angle of the condenser as parameters to calculate the luminance of the surface of a transparent liquid crystal display. The light collector was installed at 55∘ from the horizontal plane and mirror. A high level of illumination was obtained when these were laminated together at an angle of 70∘. To select a suitable diffuser, we prototyped and measured the brightness of the mid-air image with an LED lamp to simulate sunlight in three settings: summer solstice, autumnal equinox, and winter solstice. The maximum luminance of the mid-air image displayed by collecting actual sunlight was estimated to be 998.6 cd/m2. This is considerably higher than the maximum smartphone brightness to allow for outdoor viewing, and it can ensure fully compatible visibility.

Deep neural network approach for annual luminance simulations

Annual luminance maps provide meaningful evaluations for occupants’ visual comfort and perception. This paper presents a novel data-driven approach for predicting annual luminance maps from a limited number of point-in-time high-dynamic-range imagery by utilizing a deep neural network. A sensitivity analysis is performed to develop guidelines for determining the minimum and optimum data collection periods for generating accurate maps. The proposed model can faithfully predict high-quality annual panoramic luminance maps from one of the three options within 30 min training time: (i) point-in-time luminance imagery spanning 5% of the year, when evenly distributed during daylight hours, (ii) one-month hourly imagery generated during daylight hours around the equinoxes; or (iii) 9 days of hourly data collected around the spring equinox, summer and winter solstices (2.5% of the year) all suffice to predict the luminance maps for the rest of the year. The DNN predicted high-quality panoramas are validated against Radiance renderings.

Improving the Understanding of CrIS Full Spectral Resolution Nonlocal Thermodynamic Equilibrium Radiances Using Spectral Correlation

AbstractIn recent years, significant progress has been made in fast radiative transfer model (RTM) simulation of daytime nonlocal thermodynamic equilibrium (NLTE) emission. However, NLTE remains as one important reason that prevents the hyperspectral shortwave infrared (SWIR) radiance observations from being assimilated into numerical weather prediction (NWP) models. To better understand the limitations of existing RTM‐based NLTE simulation, this study introduces a new statistical method, called Spectral Correlations to Estimate Non‐Local Thermal Equilibrium (SCENTE), to estimate the NLTE radiances in the Cross‐track Infrared Sounder (CrIS) SWIR radiance observations. SCENTE is applied to four typical season days, including spring equinox, summer solstice, fall equinox, and winter solstice. By analyzing calculation/background minus observation (BMO) of CrIS SWIR brightness temperature (BT), results show that SCENTE characterizes the NLTE well with standard deviation of differences (STD) comparable to observation noise for both daytime and nighttime, while the community RTM (CRTM) has substantially larger STD at night, mainly due to the lack of daytime NLTE just beyond the day/night terminator and the lack of aurora‐related NLTE. Detailed investigation of the biases of BMO shows that CRTM underestimates daytime SWIR NLTE effects by 0.76 K, while SCENTE overestimates SWIR NLTE effects by 0.70 K. The overestimation is because SCENTE uses CRTM‐simulated SWIR local thermodynamic equilibrium (LTE) radiances in the training, which is underestimated by 0.70 K in BT. SCENTE, complementary to RTM‐based simulations, can be used for quality control of SWIR radiances for assimilation and retrieval of atmospheric soundings.

Relationship Between Stink Bug Populations in Winter Shelters and Atmospheric Variables in Soybean Growing Areas in Southern Brazil.

Stink bugs (Pentatomidae) are among the main entomological problems in the international farming. Their ability in using alternative plants (refuges) during the off-season is one of the reasons that led them to the status of key pests in several crops. Like other insect species, stink bugs are subject to atmospheric variations. Therefore, the objective of this experiment was to evaluate the abundance, the co-occurrence, and its variations according to the weather in the off-season. The work was conducted between 2014 and 2018, in the municipality of Cruz Alta, state of Rio Grande do Sul (RS), Brazil. Every year, refuges formed by Poaceae and located around the cropped area were evaluated in the second fortnight of June, corresponding to the beginning of the winter solstice. Atmospheric variables corresponding to the evaluation period were used to explain the variation in the populations. In short, our results demonstrated interannual variations in the population abundance of stink bugs in the evaluated refuges. We also found variations in the co-occurrence between species. Finally, we demonstrate the trend in the increase in these refuges in years with cold and dry off-seasons.

Improvement of energy efficiency in ethanol production supported with solar thermal energy – A case study

The decrease of natural reserves of non-renewable energy sources increases the energy prices. That initiates the fossil fuel replacement with renewable energy sources. The sun is an unlimited source of heat, but that is not enough used for industrial processes. The main reason is the complexity of heat integration between solar heating systems, process streams, and heat storage. Streams in batch processes and the solar heat delivery are time dependent. The intensity and the duration of insolation affect the capacity of the heat that can be used or stored.This study attempts to offer and approve solutions for thermal integration between solar thermal system and process streams. For that purpose is used Pinch technology for batch processes and solution algorithm is proposed. The analysis is based on a plant for ethanol production in the city of Bitola. The heat recovery is solved with design of Heat Exchanger Network. The rest of heat demand is supplied from the solar heating systems.The purpose of this paper is the possibility for maximal replacement of the required thermal energy from fossil fuel by solar heat. Three approaches are offered. They include the heat integration of a solar heating system with and without heat storage. Two options for thermal storage are suggested. The heat storage used the pressurized water and thermal oil as separated cases. The proposed solutions are adapted to the process schedule. The size of the equipment for the solutions does not depend only on the manufacturing process and its schedule, but also depends on possibilities for collecting thermal radiation from the sun. The geolocation of the plant and the used meteorological parameters for the day of the year have a substantial impact on the final decision. The proposed 18 solutions are designed for the three characteristic days – equinox, winter and summer solstices; for systems with evacuated tubes and parabolic concentrators. The economic analysis selected the most attractive solution – heat integration with evacuated tubes and heat storage with pressurized water at the winter solstice. This solution replaced approximately 35–40% of calculated heat demand delivered by the use of fuel oil.

Effect of the pineal gland on 5-hydroxytryptamine and γ-aminobutyric acid secretion in the hippocampus of male rats during the summer and winter

Abstract Objective The present study aimed to investigate the effect of seasonal variation on neurotransmitter release in the hippocampus of normal rats and rats with pineal excision. Methods Two time points, the summer and winter solstice, which are the longest and shortest days of the year, respectively, were selected. Male Sprague–Dawley rats that underwent a sham operation without pineal excision were included as a control group. The concentrations of 5-hydroxytryptamine (5-HT) and γ-aminobutyric acid (GABA) were determined by radioimmunoassays and enzyme-linked immunosorbent assays, respectively. Results In the winter, the 5-HT and GABA levels in normal rats exhibited a significant difference compared with those in the operation group (P Conclusion The seasonal rhythm of neurotransmitter secretion by the hippocampus (5-HT and GABA) consisted of elevation during the summer and reduction during the winter. During the winter, the pineal gland exhibited a reverse regulatory effect on the secretion of 5-HT and GABA in the hippocampus, and it exhibited seasonal selectivity with regard to the regulation of 5-HT.

Study on Seasonal Variations of Plasma Bubble Occurrence over Hong Kong Area Using GNSS Observations

In this study, the characteristics and causes of the seasonal variations in plasma bubble occurrence over the Hong Kong area were investigated using the local Global Navigation Satellite System (GNSS) network. Generally, the occurrences of plasma bubbles were larger in the two equinoxes than in the two solstices. Furthermore, two seasonal asymmetries in plasma bubble occurrence were observed: plasma bubble activity was more frequent in the spring equinox than in the autumn equinox (equinoctial asymmetry), and more frequent in the summer solstice than in the winter solstice (solstitial asymmetry). The equinoctial asymmetry could be explained using the Rayleigh–Taylor (R–T) instability mechanism, due to larger R–T growth rates in the spring equinox than in the autumn equinox. However, the R–T growth rate was smaller in the summer solstice than in the winter solstice, suggesting the R–T instability mechanism was inapplicable to the solstitial asymmetry. Our results showed there were more zonally propagating atmospheric gravity waves (GWs) induced by thunderstorm events over the Hong Kong area in the summer solstice than the winter solstice. So, the solstitial asymmetry could be attributed to the seeding mechanism of thunderstorm-driven atmospheric GWs.

Action de la photopériode sur la reproduction des équidés

Juments et étalons présentent une phase de reproduction pendant les jours croissants ou longs, au printemps et en été. La majorité des juments n’ont pas d’ovulation en hiver. Ce rythme annuel de reproduction est synchronisé par les variations annuelles de la longueur du jour. Un éclairement artificiel de 14,5 h, débuté en hiver, avance la première ovulation annuelle des juments.
 Certaines des étapes de la transmission de l’information lumineuse ont été vérifiées chez les équidés. Le message lumineux est transformé en influx nerveux par des cellules spécialisées de la rétine. Cet influx, via le noyau supra-chiasmatique puis le ganglion cervical supérieur, agit sur la glande pinéale. Les pinéalocytes répondent à une stimulation noradrénergique en libérant la mélatonine. Cette hormone, sécrétée pendant la phase obscure, agit sur des récepteurs membranaires spécifiques. L’administration de mélatonine exogène sous forme d’implants sous-cutanés ou, dans certaines conditions, sous forme orale, supprime l’effet photostimulant d’un jour long. L’utilisation d’implants est actuellement à l’étude pour mettre au point un traitement de désaisonnement.
 La sécrétion des neurones à GnRH est ensuite régulée par des neuromédiateurs. La naloxone, antagoniste des opiacées endogènes, induit une décharge de GnRH suivie d’une libération de LH et de FSH chez la jument en inactivité. Les hormones thyroïdiennes ont probablement une action à ce niveau.
 L’alternance d’un mois de jours courts et d’un mois de jours longs qui permet, chez les petits ruminants mâles, d’abolir les variations saisonnières est, dans l’état actuel des travaux, inefficace chez l’étalon ou la jument.
 Pour avancer la date de la première ovulation annuelle, les éleveurs ne disposent actuellement que d’un traitement comportant 14,5 h d’éclairement par jour, commencé vers le solstice d’hiver et appliqué pendant 35 jours.

Cart-ruts in Lanzarote (Canary Islands, Spain) volcanoes tops point to Equinoxes, Summer and Winter Solstices

Cart-ruts have been observed in Mediterranean Basin, Eurasia and Africa. They are rock carved stripes and channels which unexpectedly converge and/or bend, not being useful for transportation use because constant parallelism is not kept. Cart-ruts came first to scholars attention in Malta and Gozo Islands where they are abundant and dated at Bronze or Temple Age of this Archipelago. A big conjoint European investment for Cart-ruts study only got a detailed inventory in several Eurasian and African countries. Age and use of Cart-ruts remains non-discovered: it is admitted that different ages and uses may not be the same for different or even same areas. Azores Archipelago Cart-ruts were left out of this study and we have recently described them at Lanzarote (Canary Islands, Spain) volcanoes tops and slopes and suggested that they could have been useful for space and time measurements. In the present study, Lanzarote is studied and Mt. Mina and Mt. Guardilama mountains Cart-ruts azimuths points to Summer and Winter Solstices sunrises respectively as measured from Quesera/”Cheeseboard” of Zonzamas, which is a prehistoric Guanche lunisolar calendar. Mt. Tenezara Cart-ruts azimuth is pointing towards Equinoxes sunrises, as observed from Zonzamas prehistoric calendar. Thus, a use for measure time and space could be a function for some Lanzarote Cart-ruts. We explain these findings in a prehistoric Guanche aborigine culture context probably common to Atlantic megalithic Bronze Age and to all Canary Islands having prehistoric inter-navigation, because all have similar rock Iberian-Guanche inscriptions and other common cultural traits. Sahara Desert abandoning by people also influenced Mediterranean and Atlantic culture. Probability that 3 out of 7 studied volcano Cart-ruts point to Solstices and Equinoxes by chance is close to zero as calculated by factorial probability methods.
 Keywords: Latin, Scripts, Canary Islands, Iberian, Guanche, Lanzarote, Fuerteventura, Quesera-Cheeseboard, Pyramids, Berber, Africa, Punic, Roman, Western Sahara, Tunisia, Canaria, Calendar, Etruscan, Basque, Cart-ruts, Usko-Mediterranean, Solstice, Equinox, Zonzamas, HLA, Genetics, Sahara. Atchano, Malta

A calculation method for simulation and evaluation of oil vapor diffusion and breathing loss in a dome roof tank subjected to the solar radiation

The dome roof tank (DRT) is always a main equipment for oil products storage. However, the mechanism of the heat and mass transfer for the oil vapor-air in the tank gas space remains unclear when the DRT is subjected to the solar radiation. Therefore, by considering storage conditions (e.g., the solar radiation intensity and liquid height) and taking n-hexane as a representative of light oils, and based on the Fluent software and user-defined functions (UDFs) programming, a two-dimensional calculation method and the relevant theoretical model were numerically developed to simulate and reveal the transfer mechanism under the complex storage process. Meanwhile, the feasibility of the model was verified by a self-built experimental platform for the DRT evaporation loss investigation. Under the solar radiation to a 1000 m3 DRT, the simulation results show: (1) The gas space temperature distribution can be accurately calculated, and the average temperature decreases with increasing liquid level; (2) There is a distinct counterclockwise eddy and an evident velocity boundary layer close to the wall and roof of the gas space, and the maximal gas velocity is within 0.08–0.49 m s−1, which is closely related with the storage liquid height and time; (3) The vapor concentration in the gas space increases from top to bottom with an obvious high-concentration layer near the liquid surface, and the average concentration increases with increasing liquid level and storage time; (4) The static breathing losses increase positively with the liquid level. The mean daily loss rates for n-hexane are approximately 7.37 g t−1, 20.9 g t−1, and 6.36 g t−1 for the spring equinox, summer solstice, and winter solstice, respectively. Further, the year-mean daily loss rates are about 11.5 g t−1, and 20.1 g t−1 for n-hexane and gasoline, respectively, and the correspondingly the total loss rates for a year are about 4.2 kg t−1 and 7.35 kg t−1. The research results can provide important theoretical support and design reference for reducing the breathing loss and improving the enterprise management level.