Periods Of Sunshine Research Articles

How have breeders adapted rice flowering to the growing region?

Flowering time is a crucial rice trait that influences its adaptation to various environments, cropping schedules, and agronomic characteristics. Rice breeders have exploited spontaneous mutations in heading date genes to regulate the flowering time. In the present study, we investigated how breeders in Fukui Prefecture regulated days to heading while developing promising rice varieties. Genome-wide association studies (GWAS) identified Hd1, Hd16, and Hd18 as the major genes controlling days to heading in the population. However, we suspected that this highly bred population might exhibit genomic stratification, which could lead to spurious or false correlations in the GWAS. Thus, we also conducted correlation and partial correlation analyses, which uncovered another key heading date gene, Hd17, that GWAS failed to detect because of its linkage disequilibrium with the major effect gene Hd16. Examination of haplotype frequencies across different breeding periods revealed that the early-heading Hd16 (Hd16(E)) and late-heading Hd17 (Hd17(L)) were increasingly co-selected in the Hd1 functional population. Varieties carrying this Hd16(E)/Hd17(L) combination exhibited days to heading in the range of 70-80, which corresponds to the peak temperature and sunshine period and is also optimal for grain quality and yield components in the Fukui environment. The present study highlights that it is imperative to remain vigilant for Type I (false positives) and Type II (false negatives) errors when performing GWAS on highly bred populations and to implement appropriate countermeasures by accounting for gene-by-gene interactions established through the breeding process. We also discuss the effectiveness of Hd16(E), which is not used outside Japan for subtle days to heading control but is widely used in Japan at certain latitudes.

Analysis and Optimization of a Biomass Heated Two-Stage Desiccant Cooling System Used for Greenhouse Cultivation in Hot and Humid Climates

Abstract This paper presents a multi-objective optimization of a biomass heating-based two-stage desiccant-supported greenhouse cooling system used for Orchids cultivation in hot and humid weather conditions. The simulation model has been developed considering thermodynamics, economic, and environmental aspects. The thermal coefficient of performance (COPth) of the system and greenhouse temperature have been predicted for the five most impactful months (March, May, August, September, and December) corresponding to the respective seasons of spring, summer, monsoon, autumn, and winter of a calendar year. The system maintains the peak average greenhouse temperature at a maximum of 26 °C during the prominent sunshine period (12 h) in May while ensuring a minimum of 18 °C during nighttime. In terms of system components, the residue boiler stands out as the significant contributor to exergy destruction (45%), followed by regeneration heater 1 (22%), desiccant wheel 1 (7%), and the heat recovery water heater (6%) during the critical operational month of August. Multi-objective optimization has also been conducted using the optimization toolbox provided in matlab-R2017a to determine the optimal performance and operating conditions of the two-stage desiccant cooling system. The optimal conditions display the corresponding total cost rate, considering capital and maintenance costs, operating costs, CO2 penalty costs, and exergetic efficiency.

An experimental evaluation of drying banana slices using a novel indirect solar dryer under variable conditions

Novel thermal characteristics of drying banana slices in an indirect dryer are presented for four different experimental drying conditions in the forced convection mode. The novel characteristics include measuring the airflow velocity in the drying chamber, measuring the thermal profiles in different trays comprehensively and measuring the relative humidity under different conditions. Two tests are carried for 16 h in two consecutive days (8 h per day for each test). The first test is on acloudy day followed by a sunny day, while the second test is carried out on two consecutive sunny days. Tests 3 and 4 are 24 h tests with high (0.23 m/s) and low (0.11 m/s) average drying chamber airflow velocities under good solar radiation conditions. The maximum temperatures obtained in the collector and the drying chamber are around 80 and 48 °C, respectively, for the 16 h tests. Significantly lower collector and drying chamber temperatures are obtained due to cloudy conditions. Maximum collector temperatures are around 84 and 95 °C for the high and low average airflow chamber velocities for the 24 h tests. The corresponding maximum temperatures in the drying chamber are around 50 °C for the 24 tests. The final moisture ratios are 0.26 (cloudy and sunny days) and 0.20 (two sunny days), respectively, for the 16 h tests. These final moisture ratios are lower than those obtained for the 24 h tests which are 0.32 and 0.28, respectively. Increasing the drying chamber airflow velocity results in faster moisture removal during sunshine hours for the 24 h tests. For tests 1, 2, 3 and 4, the maximum average collector efficiencies during the sunshine period are around 60, 80, 40 and 10 %, respectively. The average drying efficiencies for the total solar drying period for tests 1,2,3 and 4 on day 1 are 6.9, 6.9, 5.5 and 5.7 % respectively. These values are comparable, suggesting that the average collector powers, airflow velocities and efficiencies have a very small effect on the average solar drying efficiency for the whole drying period. The quality of the bananas slices mainly in terms of the colour and shape is also compared with previous studies and commercially available products. A reasonably acceptable quality product is obtained.

Enhancement of the performance of solar chimneys using associated petroleum gas

ABSTRACT In this article, an idea has been presented that utilizes the heat produced from the petroleum gas burning accompanying the process of oil extraction to enhance the solar chimney performance. The simulation software tool ANSYS Fluent 2020R1 was used to know the possibility of exploiting this waste energy of gas and combining it with a solar chimney. Seven gas channel configurations were tested on the solar chimney to determine which can produce the most electricity. The simulation results showed that this idea could be exploited to produce higher electric energy, and the efficiency of the solar chimney was increased so that the electric energy production process continues for 24 hours instead of production during the sunshine period only. Different designs were considered for the channels inside the solar collector. Case1 and Case2 were meant for validation purposes only. Good agreement was achieved with the previous research with a maximum error of 2%. The results showed that the circular design of the two-ring burner was the best choice which gave the optimum electric power from the system of about 121.1 kW. It was noted that the circular design of the two-ring burner achieved the highest thermal efficiency, which amounted to 0.523%.

Towards Cleaner Cities: An Analysis of the Impact of Bus Fleet Decomposition on PM and NOX Emissions Reduction in Sustainable Public Transport

The problem of poor air quality in urban areas has a negative impact on the health of residents. This is especially important during periods of smog. In Poland, as in other countries, the problem of poor air quality, especially during the winter season, is associated with a high concentration of particulate pollutants in ambient air (PM10, PM2.5). Sources of particulate emissions, in addition to solid-fuel boilers, include means of transportation, especially those equipped with diesel engines. In turn, during periods of strong sunshine (spring and summer), the problem of photochemical smog, whose precursors are nitrogen oxides NOX, arises in urban areas. Their main sources of emissions are internal combustion engines. Therefore, to improve air quality in urban areas, changes are being made in the transport sector, among which is upgrading the fleet of urban transport vehicles to low- or zero-emission vehicles, which are more environmentally friendly. In addition, measures that reduce the harmfulness of the transportation sector to air quality include the introduction of clean transportation zones, as well as park-and-ride (P&R) systems. The purpose of this article is to present the results in terms of PM10, PM2.5, and NOx emission reductions, implemented over a period of two years (2021–2022) in the area of the Rzeszow agglomeration, related to the modernization of the suburban bus fleet and the implementation of a P&R system for passenger cars. The results of the study were compared with the value of estimated emissions from coal-fired boilers used for residential heating and hot water, which also contribute to smog. Thanks to the implementation of the project, i.e., the replacement of 52 old buses with new buses of the Euro VI emission class and the construction of new P&R spaces, the total average annual reduction in emissions amounted to approximately 703.6 kg of PM10, approximately 692.7 kg of PM2.5, and a reduction of approximately 10.4 tons of NOX.

Effect of Artificial Structures of Selected River on Waterblooms throughout Long-term Monitoring

The study investigated the effect of artificial structures on waterbloom in a river, focused on Dalsung Weir located in the middle of the Nakdong River in South Korea. Results from five years of long-term monitoring showed that species of green algae were the most abundant, although cyanobacteria were the dominant species during waterblooms. The waterblooms were mainly affected by the following factors: 1) the reversal phenomenon of air temperature and water temperature, 2) long periods of sunshine, and 3) rainfall events. The results of the principal component analysis for waterblooms in the study area suggested that multiple factors, such as water quality and meteorological conditions, should be taken into account. The results of the analysis for pollution sources around the study area indicated that the pollution of the river was aggravated when flows from large-scale constructions in the adjacent watershed were not properly managed. Overall, waterblooms at the study area occurred due to various causes, not just one simple reason, such as lowering the flow velocity of the river because of artificial structures. In addition, the value of water resources secured by weirs should be considered. The study provides a scientific basis for elucidating the mechanism of waterblooms in rivers.

Variability in 'Capri' Everbearing Strawberry Quality during a Harvest Season.

Strawberries are appreciated by consumers for their characteristic taste and health benefits, which enhance their demand throughout the year. Everbearing strawberries can produce fruits for a longer period and could thus meet this demand, but the fruit quality depends on environmental factors and the cultivar. This study focused on the effect of environmental conditions on the physical attributes and the composition of everbearing Capri cultivar fruit harvested from the end of June to the end of October. A positive correlation was observed between temperature and organic acid content (r = 0.87), and a positive correlation was observed between sunshine duration, anthocyanin (r = 0.87) and phenolic compound contents (r = 0.89). Additionally, the composition of sugars was affected by the environmental conditions. While strawberries harvested towards the end of October, when lower temperatures predominated, were larger in size and had a higher sugar/acid ratio, fruit harvested in the middle of August, when there were longer periods of sunshine, had higher anthocyanin and phenolic compound contents. In conclusion, strawberries with higher sugar/acid ratios are obtained when temperatures are lower, while strawberries exposed to longer periods of sunshine are richer in health-promoting compounds.

Design and performance analysis of solar air heater with phase change materials

A novel solar air heater (SAH) with provision of integrating phase change material (PCM) was designed and developed in the Department of Energy, Tezpur University located in (26.7003°N and 92.8308°E). A code was developed in MATLAB platform to estimate design parameters of the PCMSAH viz., (i) air mass flow rate (0.018 kg/s), (ii) length of the absorber plate (1.57 m) and thickness of PCM cavity (1 cm) based on energy analysis. Required quantities of selected PCMs viz., acetamide (14.56 kg), stearic acid (12.12 kg) and paraffin wax (11.30 kg) were also assessed based on the PCM melting depth. Close agreement between the simulated and experimental outlet temperature was obtained and the mean relative error between experimental and theoretical outlet temperature for three different PCMs are 4.50 % (paraffin wax), 2.32 % (stearic acid) and 2.63 % (acetamide). Performances of the SAH with various PCMs (including acetamide, stearic acid, and paraffin wax) were compared to those of an identical SAH without PCM during both charging and discharging periods of operation. According to the outlet temperature profile of SAH with PCM compared to SAH without PCM, use of PCM becomes advantageous in terms of higher and smoother outlet temperature during the low sunshine period. The absorbed, useful, loss and stored heat for all the three PCMs were estimated, and paraffin wax was found to be highest as 36.56 kW, 14.13 kW, 0.83 kW and 21.59 kW. In terms of efficiency the paraffin wax (52.83 %) based SAH ranked first followed by stearic acid (52.31 %) and acetamide (47.25 %). During performance comparison between SAH with PCM and without PCM, efficiency of SAH with acetamide is found to be 15.09 % higher to the SAH without acetamide, similarly for SAH with paraffin wax is 8.18 % and acetamide is 6.67 % higher to the SAH without PCM respectively. The uncertainty analysis was carried out for thermal efficiency of the SAH is determined to be ±2.02 %. The novel PCM integrated SAH will be useful in space heating and solar drying of the local perishable agricultural products. It is also possible to carry out detail technique for selection of PCM for solar drying application along with the exergy, economy, and environmental analysis of the PCMSAH.

Factor regression as a tool to predict Be-7 concentration in the air

In this study, the relationship between 7Be concentrations and meteorological conditions (including air pollution) was analyzed by means of the factor regression method as a prediction analysis approach. The study concerned central Poland (the city of Lodz) during the solar 24 cycle (in 2010–2020). It was found out that the variation in 7Be concentration in the air was highly correlated with meteorological conditions and aerosol concentrations. This study demonstrated a long-term empirical relationship between temperature, humidity, and sunshine period (insolation) and TSP concentration. Factor regression was applied to predict the 7Beisotope concentration changes in the troposphere based on data from the last whole 11-year solar cycle.

Evaluation of Solar Radiation and Atmospheric Air during Hay Harvesting in Kazakhstan

The study presents a probabilistic and statistical assessment of the actinometric characteristics of solar radiation and temperature and humidity parameters of atmospheric air during the hay harvesting period in Kazakhstan. The following characteristics are considered actinometric: The duration of the sunshine period, the total solar radiation flow, and the average intensity of the total solar radiation per unit area of the horizontal surface with clear skies and average cloud cover. From the parameters of atmospheric air, its temperature, humidity, and moisture absorption capacity are calculated. The authors present their average values, standard deviations, confidence intervals for the average value, coefficients of variation, and probability densities of the distribution of these parameters.

Twilight of Democracy: The Seductive Lure of Authoritarianism

Twilight of Democracy: The Seductive Lure of Authoritarianism

Evaluation of efficiency of double slope solar still and drinking water yield using silver nanoparticle mixed with phase change material

ABSTRACT This study shows the contribution of silver nanoparticles mixed with macro-encapsulated phase change material (PCM) in a double slope solar still. Experiments are carried out in three different depths and settings, first using simple double slope solar still, then by addition of PCM, and finally using PCM mixed with silver nanoparticles. Results obtained are compared during the sunshine period and also after sunset. The study shows that the silver nanoparticles in PCM results in reducing the yield and efficiency of the double slope solar still by 7.64% and 5.26% during the charging period. However, it continues to deliver potable water even after sunset due to the stored latent heat in the PCM. The higher thermal capacity of the PCM and the higher thermal conductivity of the silver nanoparticles resulted in a 16% increase in drinking water yield and a 62.53% rise in the thermal efficiency of the double slope solar still. The final cost per liter of the potable water generated using the double slope solar still was reduced to 3.80 INR and the payback time is 2 years which can be reduced further using PCM and nano-enhanced PCM inside the solar still.

Prediction of diffuse solar radiation using machine learning models based on sunshine period and sky‐clearness index for the humid‐subtropical climate of India

AbstractMachine learning (ML) models were developed to estimate monthly average diffuse solar radiation (DSR) with sky‐clearness index and relative sunshine period as inputs for the humid subtropical climate of India. Three categories of ML models were defined, each having six models. The solar radiation data was split into two parts, the “Training dataset” used to develop the models and the “Validation dataset” used to test the models. Model accuracy was investigated as a function of various commonly used statistical pointers. A comparison was made between the ML models and well‐known empirical models from prior research. Global performance indicator was used to rank ML models within each category. The projected values from the ML models and solar radiation data were in reasonable agreement. Thus, DSR can be accurately predicted using ML models in the area under consideration.

Differences in the expression of soluble proteins in freshwater and brackish‐water ecotypes of the snail Theodoxus fluviatilis

The neritid snail Theodoxus fluviatilis has formed regional subgroups in northern Europe, where it appears in both freshwater (FW) and brackish water (BW) in coastal areas of the Baltic Sea. These ecotypes show clear differences in osmotolerance and in the modes of accumulating organic osmolytes under hyperosmotic stress. We reasoned that the expression patterns of soluble proteins in the two ecotypes may differ as well. BW snails have to deal with a higher salinity (up to 20‰) than FW snails (0.5‰) and also cope with frequent fluctuations in environmental salinity that occur after heavy rains or evaporation caused by extended periods of intense sunshine. Therefore, the protein expression patterns of specimens collected at five different FW and BW sites were analyzed using 2D SDS-PAGE, mass spectrometry, and sequence comparisons based on a transcriptome database for Theodoxus fluviatilis. We identified 89 differentially expressed proteins. The differences in the expression between FW and BW snails may be due to phenotypic plasticity, but may also be determined by local genetic adaptations. Among the differentially expressed proteins, 19 proteins seem to be of special interest as they may be involved in mediating the higher tolerance of BW animals towards environmental change compared with FW animals.

A Review on Possible Combination of Solar Dryer Materials for Crops in the Philippines

Direct sun drying, also known as open sun drying, is the most cost-effective and environmentally beneficial technique of agricultural product preservation, but it degrades crop quality. Solar dryers play an essential part in producing high-quality and hygienic products; however, it is cost and maintenance expensive. Also, it has an inadequate drying performance when off sunshine period, night-time, and especially during different seasons. As a result, this study looks at a variety of low-cost options, high-efficiency materials that have been used in previous studies to give further research, an idea on what would be the ideal combination of cost-effective materials that can be used by small-scale farmers in far-flung areas with off-grid. In addition, this study explores several optimization methodologies, procedures, and processes for efficiently storing energy even when solar radiation is low to further optimize and prolong the solar dryers’ performance.

Deterministic and probabilistic analysis of different empirical models to estimate monthly mean diffuse solar radiation for composite climatic region of India

AbstractThis research compares the performance of the models to estimate monthly mean diffuse solar radiation (DSR) on a horizontal surface for composite climatic region of India. The goal is to identify the most accurate model using deterministic and probabilistic analysis through two levels of uncertainty in daily sunshine period to examine the accuracy of the model that will be used to estimate DSR in the region under consideration. The meteorological data were collected from Indian Meteorological Department for the city of New Delhi (28°34′N, 77°12′E) which comes under composite climatic region prescribed by the Energy Conservation Building Code for India. From the literature, 150 typical models were chosen and categorized into three categories correlating diffuse fraction to sky‐clearness index and relative sunshine period. The models are statistically evaluated using well‐known statistical indicators in a unique way. In addition, the global performance indicator (GPI) is calculated using scaled values of indicators. The GPI of the chosen models ranged from −2.2912 to 0.2584, with the greatest value indicating the best model. Following that, the models are then ranked in decreasing order of GPI. Finally, the performances of the models are also checked for different locations having similar climatic conditions. Thus, results of this work are useful for impoverished countries as well as remote areas having similar environment conditions.

A fully analytical model of a box solar cooker with sensible thermal storage

A box-type solar cooker supplemented with a sensible heat storage medium (for nocturnal cooking) has been analytically investigated. Unlike other available analytical studies where the relevant time interval is divided into a large number of smaller intervals and time marching is conducted numerically, here, a series of sinusoidal functions for time-dependent system driving parameters is considered via which fully closed form solutions are derived for cooking fluid and storage medium temperatures as functions of time. Here, the influences of storage medium mass and two newly defined parameters: cooking vessel area fractions for day and night cooking are investigated. Results reveal that the system’s performance increases with reduced storage medium mass and increased night cooking vessel area fraction. It is inferred that increased area of vessel at day, on one hand reduces day cooking time, while on other hand, raises the night cooking time, and therefore, its value must be selected by considering these two effects. Further, the calculations also predict that the maximum storage medium temperature is not attained at the end of sunshine period, but some time before it. Thus, charging of this medium must be stopped at the time beyond which its temperature begins to decrease. This work therefore lays down guidelines for the design of box type solar cookers with sensible thermal storage and can prove useful in predicting the appropriate time at which charging of storage medium must be ceased and also in selecting the cooking vessel dimensions for both day and night cooking.

Особливості розвитку популяцій люцерни за різних умов вирощування

Особливості розвитку популяцій люцерни за різних умов вирощування

An experimental assisted mathematical modeling to study the desorption capacity of the clay based solid desiccant

Since the moisture present in the vegetables and fruits are initially more, they are endangered to spoil quickly. The ability of the desiccant materials to absorb moisture can be used for drying. By incorporating desiccants in the drying process, drying can also be carried out during no sunshine periods. The absorbed moisture can be desorbed by passing hot air stream through the desiccants. A cylindrical desiccant mould with varying diameters of concentric holes, comprising of vermiculite (20%), bentonite (60%), cement (10%) and calcium chloride (10%) has been prepared. The sizes of the concentric holes were made in three different diameters as 6, 12 and 18 mm. Different mass flow rates and temperatures were followed to conduct the experiment as per Box- Benhen design. The ANOVA analysis was performed to arrive the percentage of contribution of influence over the desorption. Various indicators including the percentage of error between measured and predicted responses were employed to uphold the accuracy of the proposed mathematical model. The extensive statistical study reveals that the 6 mm of hole diameter, 0.003 Kg m−2s of mass flow rate and 60 °C temperature are the optimal parameters for the solid desiccant to regenerate effectively.

Epidemiology and prediction models for themanagement of rapeseed–mustard diseases: current status and future needs

The productivity of rapeseed-mustard in India is quite low as compared to the world scenario. It is mainly due to important diseases, Alternaria blight, white rust, downy mildew, powdery mildew, and white or Sclerotinia rot. Knowledge of epidemiologyand forecasting provide the basic information to developefficient and workable plant disease control models. The various weather variableslike temperature (T), relative humidity (RH), rainfall, wind velocity, and direction, leaf wetness duration, and solar radiation influence differentparameters of infection process, and disease development. Interaction between these weather variables and disease development pave the way for the development of the prediction models. Prediction models developed for the management of important diseases of rapeseed-mustard revealed that Alternaria blight is favoured by Tmax of 20–25 °C, Tmin of 15 °C, RHmor > 90% and RHeve > 50% where as white rust influencedby > 15 °C and RH > 65% with intermittent rains. Similarly, for downy mildew, Temprange of 15–20 °C with high RH was considered optimal for its progress. Leaf wetness duration of 4–6 h at 20 °C and 6–8 h at 15 °C is essential to initiate the downy mildew infection. Stag-head due to mixed infection of downy mildew and white rust is favoured by a Temp 20 °C with high RH and reduced period of sunshine (2–6 h/day) with rainfall up to 161 mm. Powdery mildew development is favoured by Temprange of 16–28 °C, mean RH 80%), Tmax up to 25 °C and Tmin of 5–12 °C. Often prediction models developed at one location may not fit atother locations. It indicates that data needs to be generated for a longer period and the model be tested atMultilocation. The disease-forecasting models must be developed by taking into account the crop variety, the prevalence of a particular pathotype and the microclimatic factors.