Bright Sunny Days Research Articles

Experimental investigation of a novel-designed inclined solar still with bio-wick under dynamic water flow

ABSTRACT This study experimentally investigates the inclined solar still (ISS) with the incorporation of fins and natural bio-jute cloth under dynamic flow. Experiments are conducted on bright sunny summer days in Coimbatore, Tamil Nadu, India. The newly developed ISS features greatly support passive solar desalination. An increase in mass flow rate (Mf) increases heat transfer meticulously pointing out 0.65, 0.8, and 1 kg/min case absorber, and the water temperature difference is within 3°C. An Mf of 0.285 kg/min is secure for the maximum water temperature reach and clean water yield of 70°C and 4.1 kg/m2, respectively, along with jute cloth, it was 1.6 kg/m2 more against without jute cloth. The presence of a jute cloth cumulative water yield of 2.5 kg/m2 at 0.635 kg/min is very close to the absence of a wick cumulative yield of 2.3 kg/m2 during 0.285 kg/min. From these results, the authors conclude higher Mf is feasible to increase the still performance and clean water yield. The implementation of a fully renewable passive solar still is strongly recommended to attain renewable and sustainable desalination.

Light Spectral Regimes under a Closed and Dense Canopy: Evidence from Mesua ferrea Trees for Human Comfort in Urban Landscape Planning


 
 
 Trees play an important role in urban landscape planning due to their multi-faceted functions including the provision of human comfort through shade and cooling and air pollution abatement. Mesua ferrea is the national tree of Sri Lanka with multi-colored leaves and pyramidal dense canopy architecture, which can be promoted to grow in roadside gardens and parks to gain more attraction and attention. It is important to know how different trees provide human comfort under the canopy. In the present study, we measured the transmittance spectra in the 318-885 nm range using a high-resolution spectroradiometer under the canopy of selected Mesua ferrea trees on bright sunny days. The change in shade casting on the ground during the day was modeled. In addition, the temperature, CO2, and relative humidity were also measured. The light transmittance through the canopy is reduced when moving from the outer edge of the canopy (1,142 μW.cm-2.nm1) to the trunk-base (0.82 μW.cm-2.nm-1) on the horizontal plane. It was obvious that the irradiance received closer to the base of the tree is not sufficient to support the understory plant growth. The irradiance levels of blue (B: 400-500 nm), red (R: 650-680 nm), and far-red (FR: 700-885 nm) components of the transmittance spectra under the canopy were also found significantly low compared to sunlight, with significantly altered R:B, R:FR and B:FR ratios. Importantly, a 14 fold cut down in the UV radiation (318-400 nm) under the canopy beyond half of the canopy diameter towards the trunk was also observed. Under the canopy, there was a temperature reduction of about 1° C on bright sunny days perhaps due to the reduced irradiance and the altered spectrum, and the reduced CO2 concentration (by 5%). We identified that the Mesua trees are suitable for human comfort, and thus can be recommended for roadside planting and for public parks in urban landscape planning.
 Keywords: Shade caste, Radiation spectrum, Mesua ferrea, Landscape planning, Urban planning
 
 

Induction of stomatal opening following a night-chilling event alleviates physiological damage in mango trees

Chilling events have become more frequent with climate change and are a significant abiotic factor causing physiological damage to plants and, consequently, reducing crop yield. Like other tropical and subtropical plants, mango (Mangifera indica L.) is particularly sensitive to chilling events, especially if they are followed by bright sunny days. It was previously shown that in mango leaves stomatal opening is restricted in the morning following a night-chilling event. This impairment results in restraint of carbon assimilation and subsequently, photoinhibition and reactive oxygen species production, which leads to chlorosis and in severe cases, cell death. Our detailed physiological analysis showed that foliar application of the guard cell H+-ATPase activator, fusicoccin, in the morning after a cold night, mitigates the physiological damage from ‘cold night–bright day’ abiotic stress. This application restored stomatal opening, thereby enabling gas exchange, releasing the photosynthetic machinery from harmful excess photon energy, and improving the plant’s overall physiological state. The mechanisms by which plants react to this abiotic stress are examined in this work. The foliar application of compounds that cause stomatal opening as a potential method of minimizing physiological damage due to night chilling is discussed.

Genomic and transcriptomic analysis of sacred fig (Ficus religiosa)

BackgroundPeepal/Bodhi tree (Ficus religiosa L.) is an important, long-lived keystone ecological species. Communities on the Indian subcontinent have extensively employed the plant in Ayurveda, traditional medicine, and spiritual practices. The Peepal tree is often thought to produce oxygen both during the day and at night by Indian folks. The goal of our research was to produce molecular resources using whole-genome and transcriptome sequencing techniques.ResultsThe complete genome of the Peepal tree was sequenced using two next-generation sequencers Illumina HiSeq1000 and MGISEQ-2000. We assembled the draft genome of 406 Mb, using a hybrid assembly workflow. The genome annotation resulted in 35,093 protein-coding genes; 53% of its genome consists of repetitive sequences. To understand the physiological pathways in leaf tissues, we analyzed photosynthetically distinct conditions: bright sunny days and nights. The RNA-seq analysis supported the expression of 26,479 unigenes. The leaf transcriptomic analysis of the diurnal and nocturnal periods revealed the expression of the significant number of genes involved in the carbon-fixation pathway.ConclusionsThis study presents a draft hybrid genome assembly for F. religiosa and its functional annotated genes. The genomic and transcriptomic data-derived pathways have been analyzed for future studies on the Peepal tree.

Experimental evaluation of hydrothermal performance of solar air heater with discrete roughened plate

• The novel discrete double arc roughness has been used in a SAH and performed numerical and outdoor experimental studies. • Optimum results were found at a p/e of 8.33 and α of 60° for Nu, h and f & THP. • Optimum results were found at a p/e of 11.67 and α of 60° for η th . • Nu and f enhanced by 2.87 and 2.47 times respectively in comparison with smooth plate. • Maximum value of THP was found to be 2.82 at a Re of 13,935 and p/e of 8.33. • Correlations has been developed for Nusselt number and friction factor and deviation were found with experimental values within ± 18%. The solar air heater has a low convective heat transfer coefficient because the absorber plate and moving air form a laminar sub-layer. Adding artificial roughness to the absorber surface is one of the most efficient heat transfer and thermal efficiency augmentation techniques utilised in SAH duct construction. The absorber plate is given new double arc discrete shaped roughness geometry. The Nu, f, and η th characteristics of a rectangular duct were evaluated employing a new double arc discrete roughness element on one side of the SAH wall and insulation on the other three sides.The outdoor investigation has been carried out with roughness parameters are relative roughness pitch (p/e) of 6.67, 8.33,10,11.67, relative roughness height (e/D h ) of 0.027, angle of arc or attack angle (α) of 60°, Reynolds number (Re) in the range of 3000–14000, and as aspect ratio (W/ H) of 8 were selected. Solar radiation intensity ranged from 860 W/m 2 to 895 W/m 2 on a bright sunny day was used. Between 11:00 A.M. and 2:00P.M., from morning to afternoon, the outside test was also done. Optimum results were found at a p/e of 8.33 and α of 60° for Nu, h and f & THP. Optimum results were found at a p/e of 11.67 and α of 60° for η th . The maximum enhancement of Nu & f by 2.87 & 2.47 of the roughened plate respectively was found when compared to the smooth absorber plate under similar flow conditions. Maximum value of Nu and f were found 121.66 and 0.0342 respectively. Maximum value of h and η th were noticed 75.23 W/m 2 k and 87.95% respectively. The maximum enhancement of thermo-hydraulic performance (THP) was noticed under-investigated parameters of 2.82 at p/e of 8.33, and Re of 13935. Heat transfer and friction factor correlations have been developed deviation were found with experimental values within ± 18%.The mathematical model, which is utilised for SAH duct design and performance prediction under various operating conditions, has been validated using experimental data.

Performance Optimization of Solar Photovoltaic System using Parabolic Trough and Fresnel Mirror Solar Concentrator

An attempt has been taken to design parabolic trough and Fresnel mirror solar concentrator with the purpose of optimizing the output power of a photovoltaic system for both bright sunny day and cloudy day by using a 72-cell 5W photovoltaic solar panel. The PV system's efficiency has been analyzed in terms of output voltage, current, and power of the solar panel. Accordingly, to our expectation, we observed that on a bright sunny day, the output power improvement of the solar panel is 26.81% for the parabolic trough and 17.89% for the Fresnel mirror concentrator. On a cloudy day, both concentrators improve output power by 22.3% and 14.1%, respectively. In terms of power optimization of a photovoltaic system, the following has been discerned: a solar photovoltaic concentrator system with a parabolic trough is much more effective than one with a Fresnel mirror.

Throwaway Shadows Using Parallel Encoders Generative Adversarial Network

Face photographs taken on a bright sunny day or in floodlight contain unnecessary shadows of objects on the face. Most previous works deal with removing shadow from scene images and struggle with doing so for facial images. Faces have a complex semantic structure, due to which shadow removal is challenging. The aim of this research is to remove the shadow of an object in facial images. We propose a novel generative adversarial network (GAN) based image-to-image translation approach for shadow removal in face images. The first stage of our model automatically produces a binary segmentation mask for the shadow region. Then, the second stage, which is a GAN-based network, removes the object shadow and synthesizes the effected region. The generator network of our GAN has two parallel encoders—one is standard convolution path and the other is a partial convolution. We find that this combination in the generator results not only in learning an incorporated semantic structure but also in disentangling visual discrepancies problems under the shadow area. In addition to GAN loss, we exploit low level L1, structural level SSIM and perceptual loss from a pre-trained loss network for better texture and perceptual quality, respectively. Since there is no paired dataset for the shadow removal problem, we created a synthetic shadow dataset for training our network in a supervised manner. The proposed approach effectively removes shadows from real and synthetic test samples, while retaining complex facial semantics. Experimental evaluations consistently show the advantages of the proposed method over several representative state-of-the-art approaches.

The comparison of Canopeo and samplepoint for measurement of green canopy cover for forage crops in India

Canopy covers can be measured using destructive (visual) and non-destructive methods (spectral indices, photogrammetry, visual assessment, and quantum sensor). The precision of crop cover estimation, however, is dependent on the selection of appropriate methods. Studies were conducted at the Indian Grassland and Fodder Research Institute, Jhansi to compare the forage crops canopy cover estimated using photogrammetry software (Canopeo and SamplePoint) and visual assessments. Assessments were performed in three summer crops (corn, cowpea, and sorghum), two winter crops (Egyptian clover, and oats), and bare ground condition. For each plot, three nadir images (directly above the canopy) were captured using digital cameras from a height of 1.5 m above the soil surface between 10 AM to 2 PM on bright sunny days. The results indicated that the relationships between visual assessment and Canopeo (regression coefficient, (R2=0.96), visual assessment and SamplePoint (0.96), and Canopeo and SamplePoint (0.98) were linear when data were pooled across all the crops. SamplePoint and Canopeo is further, appropriate for cowpea (Pearson coefficient (R=0.99 and 0.94), oats (0.92 and 0.97), and sorghum (0.46 and 0.51), respectively. SamplePoint and Canopeo are not suitable for berseem (-0.15) and corn (-0.61), respectively, due to dead residues after the first harvest in berseem and taller corn might have influenced the image quality. Therefore, the stage of the crop, the height of the crop, and dead residues around the plants can greatly influence the estimation of crop cover. In conclusion, the results indicated that this photogrammetry software can be used for non-destructive crop canopy measurement with the above-mentioned precautions in the forage crops tested. •Forage canopy cover is estimated generally by visual scoring, and the outcome varies widely from person to person.•Photogrammetry methods (Canopeo and SamplePoint) were positiviely correlated with visual scoring for cowpea, oats, and sorghum.•However, Canopeo and SamplePoint may not suitable for taller crops like corn and ratoon crops like berseem.

Determination of differences in temperature regimes on healthy and bark-beetle colonised spruce trees using a handheld thermal camera

In this study, we compared the daily temperature regimes of healthy uninfected trees in the interior of a forest stand and at the fresh forest edge with infested trees at the forest edge in an area affected by a bark beetle outbreak. We estimated the potential of a handheld thermal camera for early identification of bark-beetle infested trees. We show that infested trees have significantly higher trunk temperatures than uninfested trees, which is more visible on the shine side of the trunk, and we report the differences in temperature between the shine and shadow sides. The differences are more noticeable on a warm, bright, and sunny day than on cold and cloudy day. The different intensity of solar radiation does not affect the distinction between infested and uninfested trees. The handheld thermal camera shows potential for identifying bark-beetle infested trees by scanning tree trunks on bright sunny days.

System Design and Realization of a Solar-Powered Electric Vehicle Charging Station

The alarming situation of global warming leads to the full adoption of the renewable energy-based transportation system. However, their sustainable deployment at a mass level has been a challenging task. This article presents the design aspects and practical implementation of the modern solar-assisted level-2 electric vehicle charging station which is controlled by a Type-1 vehicle connector. The designed model is developed in MATLAB/Simulink environment, the circuit operation is examined and its methodological model is derived to study the parametric design features. Furthermore, the complete hardware setup has developed to test the performance of the power factor correction under the steady-state condition with respect to variation in load for the input of 3 kW, 230 Vrms at 1-phase, 50 Hz rated, and to produce a 48 V buck converter dc output. The 6.4 kW solar photovoltaic (PV) charging station, installed at the Centre of Advanced Research in Electrified Transportation building parking area in Aligarh Muslim University campus, selected as a case site. Moreover, the controller circuit is simulated in PROTEUS software and a prototype model has been tested in the lab. The study is performed on a 10 kWh lithium-ion battery pack on a bright sunny day at standard test condition of the solar panel.

Effect of aspect ratio on thermal performance of cavity receiver for solar parabolic dish concentrator: An experimental study

Proper design of the receiver is vital to maximize the performance of solar parabolic dish concentrator. In this paper, an experimental study on the thermal performance of the conical cavity receiver with different aspect ratios for solar parabolic dish concentrator is presented. The receivers of aspect ratio 0.8, 1.0 and 1.2 are constructed for a given cone angle and tested in bright sunny days with average beam radiation above 600 W/m2. The energy efficiency, exergy efficiency and overall heat loss factor of the receivers were evaluated and compared. As expected, the receiver surface temperature got reduced with increase in aspect ratio. However the thermal performance is observed to decrease. The receiver with aspect ratio of 0.8 shown highest performance among all the receivers tested. It is revealed that reduction in receiver surface temperature alone is not adequate to improve the thermal performance, the surface area is also an influencing factor. Hence the aspect ratio of the receiver has a significant impact on the thermal performance and should be carefully chosen while designing the receiver. The results presented in this work are useful for further optimization of the receiver design.

Current perspectives on pollen cryopreservation in horticultural species

Cryopreserved pollen collections provide long-term security for wildflora, ornamentals, fruit and vegetable crops, medicinal herbs and endangered species. Technology has been developed for long-term cryopreservation of pollen in the form of nuclear genetic diversity (NGD) of mango, amla, pomegranate, jackfruit, guava, passion fruit, jamun, different species and cultivars of citrus, papaya (different species), grape, tomato, eggplant (Solanum gene pool), onion, capsicum, rose, gladiolus, gerbera, carnation and RET species of medicinal plants. Pollen collecting is usually done on a bright sunny day between 10-11 am. Pollen collections are subjected to viability indexing by germination in vitro by the hanging drop or cellophane techniques. Pollen samples are packed either in gelatin capsules or butter paper packets, sealed air tight in polyethylene aluminium laminated pouches and lowered into a canister of a cryoflask. The fertility of stored pollen is tested under field conditions through controlled pollination. The pollen cryobank is managed by periodic replenishment of the cryogen. With the recent advances in allied bio-scientific areas in which cryopreserved pollen could be used in general crosses, shuttle breeding maintenance of B line in male sterile based hybrid seed production. Security of male parent is also ensured in the cryobank. Pollen cryopreservation protocols developed for different horticultural species will be discussed in details.

Raining sideways II – a new hope

Raining sideways II – a new hope

Determination of the Daily and Weekly Solar Radiation of September 2015 at Presco Campus Ebonyi State University, Abakiliki-Nigeria

This study focused on the measurement of global solar radiation at the Presco Campus of Ebonyi State University, Abakaliki-Nigeria (06°N, 08°E, 43.9 m) in the month of September, 2015. The variability in global solar radiation was measured using a daystar meter on 30 min, hourly, daily, weekly and monthly scales. GPS global positioning instrument No. 13467763 was also used in determining the elevation and position of the area where the experiment was carried out. The results showed that the peak of the hourly average global insolation was 2.25 W/m2. In a clear partially bright sunny day, the daily average of global solar radiation was 627.44 W/m2 while the daily average of irradiation on a cloudy day was 384.19 W/m2. On a weekly scale, the average irradiation was 2.95 W/m2 whereas on a monthly scale, the average was 11.79 KW/m2 for the month of September, 2015.

Floating and popping fun

Bubbles are a very simple, yet extremely effective way to engage children in playing, learning and exploring the world around them. They are a fantastic outdoor tool and are not just limited to bright sunny days.

Installation and Commissioning of a 100 kW Rooftop Solar PV Power Plant

Objectives: The grid connected rooftop solar photovoltaic system is gaining momentum. The feasibility study of its installation, testing, commissioning and grid connectivity issues is a must. The analysis of economic benefits in comparison with electricity charges as per utility and the payback period is prime requirement. The objective is to integrate solar power with grid and share a greater portion of solar power for the local use and contribute the solar power installed capacity of the nation Methods/Statistical Analysis: The paper gives a comprehensive study of site information, plant architecture, layout, single line diagram and test results prior to commissioning. An operation and maintenance sheet has been maintained to track the various parameters such as voltage, current and power both on DC and AC mains for individual inverters. The average V DC , I DC and P DC has been found to be 620 volts, 32 Amps, 20 kW respectively from 11 am to 4 pm on bright sunny days. Similarly, V DC , I DC and P DC were noted to be 440 volts, 27 Amps, 20 kW respectively.Findings: During light loading in the institute, the power flow from solar to grid was evidenced through net meters installed by the utility. This relieved the institute management to pay heavy electricity charges. The electricity charge by the utility for HT consumer was Rs.10 per kWh whereas the solar charges were paid at the rate of Rs. 6.4. This resulted in a significant cost saving. Application/Improvements: The power taken from grid during 11 am to 4 pm has been reduced from an average 45 kWh to 12 kWh per hour. The scheme is well suited for large commercial complex, residential buildings and offices. It can be implemented with battery back up in remote villages which has poor access to electricity.

Scope and Options of Solar Energy Use in Agriculture in Eastern region of India

Groundwater abstraction to meet irrigation demand and application of water and energy efficient irrigation technologies is becoming a difficult affair due to significant energy poverty and pervasive electricity deficits in Eastern region of India. This undermines the production and productivity of small holders. This paper discusses the energy scarcity and possible remedy by the use of solar energy as this region receives abundance solar radiation due to its geographical location and 250 -300 bright sunny days per year which can be year round source of energy for agricultural use.

Meteorite Fall at Komargaon, Assam, India

A single piece of meteorite weighing approximately 12 kg and dimension 10× 9× 8 fell at Komargaon town (lat. 26°39'N; long. 93°46'E), Golaghat district, Assam, India on 13 November 2015 (12:00 h, IST). We report here eye-witness accounts and a preliminary description of the sample which includes macro- and microstructures and a tentative petrologic-chemical classification. According to local villagers, it was a bright sunny day with a clear sky.

Thermal modeling of evacuated tube solar air collectors

This paper presents a one dimensional thermal model of a solar evacuated tube open at both ends under transient conditions. Variations of fluid mass flow rate, ambient temperature, solar radiation, and wind speed are accounted for. The semi-analytical model relies on the energy conservation equation for small control volumes along the longitudinal axis of the tube. The first order differential equations obtained for each control volume are solved by use of a fully explicit scheme using a fourth order Runge–Kutta algorithm. An experimental setup has been designed, built and calibrated in order to assess the predictions provided by the model. The comparison between simulated and experimentally measured outlet air temperatures showed a good agreement: a root mean square error on the outlet air temperature of about 0.50K and a mean bias difference of 0.15K were observed for experiments conducted on a bright sunny day. The validated model applied for steady state heat transfer is then used to conduct an analysis on different parameters. Finally, the influence of the environmental parameters (solar radiation, ambient temperature and wind speed) and the operating condition (airflow) is investigated on different performance indicators like the outlet air temperature, the efficiency, the mean convective heat transfer coefficient and the pressure drop. It appeared that the influence of wind and ambient temperatures is of minor importance although the influence of solar radiation on the outlet air temperature is significant. Moreover, the airflow is the most important parameter acting on the defined performance indicators. Higher is the airflow, better is the efficiency and lower is the outlet air temperature. On the other hand, a low airflow can conduct to as much as 100K of temperature gain, but the efficiency is then reduced to value as low as 45%.

Development and construction of a conical solar concentrator

This research work reports the development, construction and study of the performance of the conical shaped concentrator made from fabricated iron sheet of thickness 2mm. The inner side of the cone shape was line with strips of plane mirror cemented to the surface by the help of araldite mixed with sawdust. The concentrator has an aperture of 8050.20cm2 while the two solar absorber used for the study has surface area 790.60cm2 and 720.50cm2 with the concentration ratio being 9.50 and 10.60 respectively. The conical solar concentrator was tested under various operation condition, such as; different concentration ratio, static condition of the absorber fluid temperature against local time of the day showed that higher temperatures of the fluid were obtained on bright sunny days when the collector received beam radiation (highest temperature recorded =166oC) and a rapid decline of the fluids temperatures when a cloudy interception of the sun occurred.