Sunset Hours Research Articles

Crop photoperiodism model 2.0 for the flowering time of sorghum and rice that includes daily changes in sunrise and sunset times and temperature acclimation.

Daylength determines flowering dates. However, questions remain regarding flowering dates in the natural environment, such as the synchronous flowering of plants sown simultaneously at highly contrasting latitudes. The daily change in sunrise and sunset times is the cue for the flowering of trees and for the synchronization of moulting in birds at the equator. Sunrise and sunset also synchronize the cell circadian clock, which is involved in the regulation of flowering. The goal of this study was to update the photoperiodism model with knowledge acquired since its conception. A large dataset was gathered, including four 2-year series of monthly sowings of 28 sorghum varieties in Mali and two 1-year series of monthly sowings of eight rice varieties in the Philippines to compare with previously published monthly sowings in Japan and Malaysia, and data from sorghum breeders in France, Nicaragua and Colombia. An additive linear model of the duration in days to panicle initiation (PI) and flowering time using daylength and daily changes in sunrise and sunset times was implemented. Simultaneous with the phyllochron, the duration to PI of field crops acclimated to the mean temperature at seedling emergence within the usual range of mean cropping temperatures. A unique additive linear model combining daylength and daily changes in sunrise and sunset hours was accurately fitted for any type of response in the duration to PI to the sowing date without any temperature input. Once calibrated on a complete and an incomplete monthly sowing series at two tropical latitudes, the model accurately predicted the duration to PI of the concerned varieties from the equatorial to the temperate zone. Including the daily changes in sunrise and sunset times in the updated photoperiodism model largely improved its accuracy at the latitude of each experiment. More research is needed to ascertain its multi-latitudinal accuracy, especially at latitudes close to the equator.

Roosting preference and relation of abiotic factors on population of Pteropus giganteus (Chiroptera: pteropodidae) in Ludhiana

A study was conducted for estimation of fruit bat, Pteropus giganteus population and its fluctuation with respect to seasonal changes at selected roosting site of village Katani Kalan, Ludhiana, during year 2018–19. Eucalyptus globules (87.3%) and mulberry (24.0%) were most preferred for roosting. Increasing trend of population from August-January and decreased trend from February-July were observed. Number of roosted bats was higher (944) during winter and lower (690) during summer months. Negative correlation of atmospheric temperature (r=-0.88) and positive correlation of relative humidity (r=+0.32) with bat population were observed. Atmospheric temperature (r=+0.89), sunshine hours (r=+0.38) and sunset hours (r=+0.99) showed positive correlation, whereas relative humidity showed negative correlation (r=-0.38) with time of emergence of fruit bats after sunset for foraging activity. Difference between sunset hours and time of emergence varied significantly during the whole year (21–35 minutes). Our study provides baseline information, which may be useful for policy makers for P. giganteus conservation program.

Landscape-wide flight activity by wintering bats predictably follows pulses of warmth in the Midwestern United States

Abstract During winter hibernation, bats may become active for a variety of reasons. Such winter activity occurs at or near hibernacula, but the degree to which this activity represents long-distance travel across a wider landscape largely is unstudied. We documented patterns in landscape-wide winter activity across a west-central Indiana study site, providing some new insights into winter flight activity. We deployed acoustic recording devices in areas without any known hibernacula, each night from December through March over three consecutive winters. Twilight temperatures (1 h post-sunset) ranged from −23°C to 21°C across three winters. We recorded 4,392 call files and attributed 89% to a phonic group based on characteristic frequencies. Flight activity was recorded at all stations and during all winter months. Nightly activity mainly was a function of the temperature on that night. We recorded low-phonic bats (most likely big brown bats, Eptesicus fuscus) down to −4°C, but most activity occurred when twilight temperatures were > 0°C. Mid-phonic bat activity (most likely eastern red bats, Lasiurus borealis) occurred when temperatures were > 0°C, with most activity occurring when temperatures were > 5°C. Wind speeds > 6 m/s tended to suppress activity. The duration of inactive periods during cold spells had no effect on activity during subsequent warm nights, indicating no increasing drive for activity following long periods of inactivity. Most activity occurred within a few hours of sunset, regardless of temperature. Little pre-sunset activity was recorded in low-phonic bats, but mid-phonic bats sometimes were active in the hour before sunset. Our results suggest widespread and potentially long-distance travel by bats across our study area during warm periods, but the impetus behind this activity remains unclear.

Use of Available Daylight to Improve Short-Term Load Forecasting Accuracy

This paper introduces a new methodology to include daylight information in short-term load forecasting (STLF) models. The relation between daylight and power consumption is obvious due to the use of electricity in lighting in general. Nevertheless, very few STLF systems include this variable as an input. In addition, an analysis of one of the current STLF models at the Spanish Transmission System Operator (TSO), shows two humps in its error profile, occurring at sunrise and sunset times. The new methodology includes properly treated daylight information in STLF models in order to reduce the forecasting error during sunrise and sunset, especially when daylight savings time (DST) one-hour time shifts occur. This paper describes the raw information and the linearization method needed. The forecasting model used as the benchmark is currently used at the TSO’s headquarters and it uses both autoregressive (AR) and neural network (NN) components. The method has been designed with data from the Spanish electric system from 2011 to 2017 and tested over 2018 data. The results include a justification to use the proposed linearization over other techniques as well as a thorough analysis of the forecast results yielding an error reduction in sunset hours from 1.56% to 1.38% for the AR model and from 1.37% to 1.30% for the combined forecast. In addition, during the weeks in which DST shifts are implemented, sunset error drops from 2.53% to 2.09%.

Performance analysis of Neural Networks with IRI-2016 and IRI-2012 models over Indian low-latitude GPS stations

The Global Positioning System (GPS) applications are highly vulnerable to the ionospheric space weather effects. Modelling and forecasting the ionospheric effects such as time delays for GPS signals are important for real time alerts of space weather effects on GPS services. In the present work, the performance of Neural Networks (NN) model is compared with International Reference Ionosphere (IRI) models. The ionospheric Total Electron Content (TEC) observations have been collected during 2015 year, descending phase of 24th solar cycle, over three Indian low latitude GPS stations namely, Bengaluru (Geographic coordinates: 13.02°N and 77.57°E), near to geomagnetic equator, Guntur (Geographic coordinates: 16.37°N and 80.37°E), which is at Equatorial Ionization Anomaly (EIA) and Lucknow (Geographic coordinates: 26.83°N and 80.92°E), which is beyond EIA region. The performance of NN model in predicting the ionospheric TEC values is compared with IRI (IRI-2012 and IRI-2016) models during test period, October–December 2015 over three Indian low latitude regions. It is observed that IRI models (IRI-2012 and IRI-2016) have shown more the temporal differences with GPS-VTEC during sunrise hours compared to sunset hours over three low latitude regions. The performance of IRI-2016 model has apparently better than IRI-2012 model. However, it is observed that IRI-2016 model has large discrepancies over Bengaluru and Guntur station due to high VTEC fluctuations at equatorial and low latitudes. The NN models are well predicted the measured diurnal mean VTEC variations with the less errors, ±5 TECU but the differences of IRI models are ±15 TECU over all the three stations. Later, GPS-data for 10 years, 2009–2018, is collected over Bengaluru station during 24th solar cycle. The performance of NN model is validated during 2016, 2017 and 2018 years over Bengaluru GPS station. The error measurements and experimental results reported that the measured GPS-VTEC values are well predicted by NN model compared to IRI-2016 model over equatorial and low latitude GPS stations.

Quantification of Circadian Movement of Small-Leaved Lime (Tilia cordata Mill.) Saplings With Short Interval Terrestrial Laser Scanning.

The goal of the study was to quantify and identify patterns in circadian movements of small-leaved lime (Tillia cordata) saplings with the help of terrestrial laser scanning (TLS). The movements were monitored every 60 min 24 h a day and every 30 min in the hour of sunrise and sunset. In order to exclude wind effects the monitored saplings were indoors. The resulting point clouds were used in creating a time series of branch and foliage movements with high precision. The circadian vertical movement of saplings was evaluated through target points, which has a potential of capturing the point-wise movement more accurately. Our results clearly show that small saplings move their branches and leaves during 24 h in complex ways and that is difficult to identify general patterns. Since we worked with small saplings and our movement threshold was 5 mm, we detected random fluctuation–oscillation as the most common movement in monitored saplings. The results highlight the potential of TLS measurements in support of chronobiology and the possibilities to analyze circadian movements of saplings in controlled environment.

New Features of the Enhancements in Electron Density at Low Latitudes

AbstractIn this study, we present some new features of the enhancements of electron density in the ionospheric F region at low latitudes. The peak parameters of the ionosphere were recorded by Sanya (109.6°E, 18.3°N) ionosonde and electron density profiles analyzed were measured by the Qujing (103.8°E, 25.6°N) incoherent scatter radar. The peak electron density of the F2 layer (NmF2) is found to be enhanced in the afternoon and sunset hours. Common features in the cases demonstrate that the NmF2 increases at low latitudes are characterized by a descent of the peak height (hmF2). Meanwhile, the electron density at Qujing shows an increase at the bottom of the ionosphere and a depression at topside altitudes. It is consistent with those of the ionosonde measurements at Sanya, for both the daytime and nighttime enhancements. Cross correlation analyses reveal a lag of NmF2 to hmF2 in the cases. After taking time shifts some events of the enhancements in NmF2 are still associated with a downwelling hmF2, confirming the processes which drive a lower hmF2 and a convergence of plasma flux may possibly bring about a rise in NmF2.

Intermittent Fasting Could Be Safely Achieved in People With Type 1 Diabetes Undergoing Structured Education and Advanced Glucose Monitoring.

Background: Fasting during Ramadan is a form of intermittent fasting in which a person abstains from oral intake between the hours of sunrise and sunset. The fasting month of Ramadan is observed by Muslims worldwide. People with type 1 diabetes (T1DM) who choose to fast during Ramadan are at a particularly high risk of acute diabetes complications including hypoglycemia and significant hyperglycemia. We hypothesized that people with uncomplicated T1DM would be able to fast safely during Ramadan following structured education and with daily advanced glucose monitoring.Methods: People with stable and uncomplicated T1DM treated with multiple daily injections (MDIs) or continuous subcutaneous insulin infusion (CSII) who chose to fast during Ramadan were recruited for the study. Participants attended Dose Adjustment for Normal Eating (DAFNE) structured education training, and basal insulin was reduced in a controlled fashion. Participants were assigned a sensor-augmented insulin pump or FreeStyle Libre for advanced glucose monitoring. The primary endpoint was the rate of hypoglycemia during Ramadan compared to before Ramadan. Secondary endpoints were percentage time spent <4 mmol/L, >10 mmol/L (range, 4–10 mmol/L), episodes of diabetic ketoacidosis (DKA), and acute kidney injury or hospitalization for any cause.Results: Rates of hypoglycemia were significantly reduced during Ramadan compared with rates before Ramadan (0.53 ± 0. 49 vs. 0.81 ± 0.69 episodes/day, p = 0.0015). No episodes of severe hypoglycemia, DKA, acute kidney injury, or hospitalization occurred during Ramadan period. Percentage time spent >10 mmol/L (46.7 ± 17.7% vs. 42.5 ± 16.4%, p = 0.03) was significantly increased, and percentage time [range, 4–10 mmol/L (48.8 ± 15.9% vs. 50.9 ± 15.9%, p = 0.13)] and percentage time spent <4 mmol/L (4.7 ± 5.4.7% vs. 5.7 ± 6.3%, p = 0.09) were reduced, but these differences were not significant.Conclusions: People with uncomplicated T1DM could safely participate in intermittent fasting similar to Ramadan fasting if equipped with structured education and advanced glucose monitoring systems.

Long‐Lasting Latitudinal Four‐Peak Structure in the Nighttime Ionosphere Observed by the Swarm Constellation

AbstractIn this study, we provide for the first time observation of the latitudinal four‐peak structure of F region electron density in the nightside ionosphere. The special configuration of Swarm satellites, Swarm B having the chance to resample the regions of Swarm A/C with successively increasing time differences, provides an unprecedented opportunity to check the evolution of these nightside electron density peaks. Overall, the latitudinal four‐peak structures have very low occurrence rates, only 4% of the Swarm orbits. The two mid‐latitude peaks prefer to appear close to ±40° magnetic latitude, while the two low‐latitude peaks appear within ±20° magnetic latitude. Such latitudinal four‐peak structures can persist throughout the night until sunrise hours. No clear seasonal dependence is found for the two mid‐latitude peaks, while the two low‐latitude peaks are almost symmetric about the magnetic equator during equinoxes but are located at slightly higher latitudes in the summer hemisphere around solstices. The two low‐latitude peaks at late‐night hours are believed not to be remnants of the dusk‐side equatorial ionization anomaly (EIA) crests, as (a) example shows that Swarm A/C observe the development of shoulders at the flanks of the two EIA crests after sunset hours, and the shoulders become peaks 3 h later when Swarm B resamples the same region; (b) statistic results reveal that the two low‐latitude peaks during post‐midnight hours do not propagate towards the magnetic equator, as expected for EIA crests, but move slowly poleward. We suggest that the enhanced meridional wind at postmidnight hours is one possible driver for causing such latitudinal four‐peak structure of F region electron density. In addition, the simultaneous magnetic measurements from Swarm satellites are also analyzed, but they show no obvious diamagnetic effect that could help to maintain pressure balance within these electron density peaks.

Spatio-temporal analysis of ionospheric disturbances for ground based augmentation systems over a midlatitude region

Forcings from above and below the ionosphere can cause disturbances that need to be detected and corrected for navigation systems. Ground Based Augmentation Systems (GBAS) are used to give corrections to aircraft navigation systems while landing. These systems use regional ionosphere monitoring algorithms to detect the anomalies in the ionosphere. The aim of this study is to understand occurrence of ionosphere anomalies and their trends over Turkey. A comprehensive analysis of spatio-temporal variability of ionosphere is carried out for a midlatitude GPS network using Slant Total Electron Content (STEC). Differential Rate Of TEC (DROT), which is a measure of the amount of deviation of temporal derivative of TEC from its trend, is used to detect and classify the level of such disturbances. The GPS satellite tracks are grouped into north, east, west and over directions. The 24 h is divided into six time intervals. The percentage occurrence of each DROT category and the deviation from STEC trend in magnitude are calculated and grouped into satellite track directions and time intervals for 2010 (low solar activity), 2011 and 2012 (medium solar activity). The highest level of disturbances is observed in north and west directions, and during sunrise and sunset hours. The dominant periods of percentage occurrences are diurnal (22–25 h), semidiurnal (12–13 h) and terdiurnal (8–9 h) followed by quasi two-day and quasi 16-day periods. Disturbances corresponding to 50% < DROT < 70% are mostly visible during low solar activity years with magnitudes from 1 to 2 TECU. Geomagnetic storms can cause aperiodic larger scale disturbances that are mostly correlated with DROT > 70%. In 2012, the magnitude of such disturbances can reach 5 TECU. The anisotropic and dynamic nature of midlatitude ionosphere is reflected in the spatio-temporal and spectral distributions of DROT, and their percentage occurrences. This study serves a basis for future studies about development of a regional ionosphere monitoring for Turkey.

Sunny with a Chance of Curtailment: Operating the US Grid with Very High Levels of Solar Photovoltaics.

SummaryWith rapid declines in solar photovoltaic (PV) and energy storage costs, futures with PV penetrations approaching or exceeding 50% of total annual US generation are becoming conceivable. The operational merits of such a national-scale system have not been evaluated sufficiently. Here, we analyze in detail the operational impacts of a future US power system with very high annual levels of PV (>50%) with storage. We show that load and operating reserve requirements can be met for all hours while considering key generator operational constraints. Storage plays an active role in maintaining the balance of supply and demand during sunset hours. Under the highest PV penetration scenario, hours with >90% PV penetration are relatively common, which require rapid transitions between predominately conventional synchronous generation and mostly inverter-based generation. We observe hours with almost 400 GW (over 40%) of economic curtailment and frequent (up to 36%) hours with very low energy prices.

Population-based case–control study of the effect of sun glare on pedestrian fatalities in Taiwan

ObjectivesSun glare is a serious driving hazard and increases crash risks. Relatively few studies have examined the effects of sun glare on pedestrian fatalities, given that a crash has occurred....

Daily Light Integral Requirement of a Creeping Bentgrass Putting Green as Affected by Shade, Trinexapac‐ethyl, and a Plant Colorant

ABSTRACTTurfgrass quality is often limited by the availability of photosynthetically active radiation (PAR) delivered to the turf surface. The cumulative PAR at a given site during 1 d is termed the daily light integral (DLI) and is an effective measurement for quantifying light requirements for various turfgrass systems. The minimum DLI necessary to maintain acceptable quality on creeping bentgrass (Agrostis stolonifera L.) putting greens has yet to be determined. Shade timing, trinexapac‐ethyl growth regulator, and ultraviolet‐absorbing plant colorant applications may affect the DLI requirement of creeping bentgrass putting greens. The objective of this research was to determine the DLI requirement of a creeping bentgrass putting green by evaluating the effects of shade intensity and timing, as well as the influence of trinexapac‐ethyl and a plant colorant on turfgrass quality and coverage. Intensity treatments of 0, 70, 80, and 90% shade were applied during either morning (sunrise to solar noon) or afternoon (solar noon to sunset) hours from May through October 2016 and 2017 on a ‘Tyee’ creeping bentgrass, sand‐based putting green. Evaluations of visual turf quality and turf coverage were performed every 2 wk. After 2 yr, the DLI requirement to maintain acceptable putting green quality was estimated to be 30 mol m−2 d−1. Although effective in improving turf quality at times during summer months, trinexapac‐ethyl and the plant colorant did not significantly reduce the DLI requirement.

Vertical distribution and diel migration of mesopelagic fishes on the northern slope of the South China sea

Mesopelagic fishes are major components contributing to deep-sea scattering layers in the open ocean. They have the potential to support a substantial higher trophic level harvest, but knowledge about this possible resource is still rudimentary. Some of the mesopelagic fishes undertake diel vertical migration (DVM) over large depths by feeding in shallow water during darkness and migrating to depth to avoid visual predators during daylight. The vertical distribution and diel migration pattern of the mesopelagic fishes on the northern slope of the South China Sea were investigated during two multidisciplinary surveys carried out in October 2014 and June 2015. Based on acoustic and biological sampling, a distinct deep scattering layer (DSL) consisting mainly of mesopelagic fishes was identified in deep water (>300 m). Extensive diel vertical migration for hundreds of meters to form dense aggregations in the epipelagic zone (0–150 m) at night was observed in both seasons, but the migration was highly species dependent. While most of the Myctophiformes and the Perciformes undertook DVM, most of the Salmoniformes and Beryciformes remained in deep water both day and night. Based on paired day-night differences of acoustic density in the DSL, the migrating proportion of mesopelagic backscatter varied markedly in different locations, ranging from 28% to 63%, with a mean of 48% in two seasons. The extensive vertical migration occurred in separate groups at different periods during sunset and sunrise hours. Additional analysis showed that the center of gravity of the mesopelagic backscatters (200–1000 m) and their night distribution in the subsurface layer (10–150 m) were positively correlated with the mean temperature in respective zones. Moreover, some of the mesopelagic communities on the slope were found to undertake pronounced diel horizontal migration in a pattern of towards the shore in the evening and away from the shore after midnight. The horizontal migrant species were mainly Myctophidae, in particular Diaphus chrysorhynchus and Diaphus garmani. Simultaneous analysis on typical tidal currents indicated that the horizontal migration, over a large distance with high speed and biomass, could not be explained by passive transport due to tidal currents alone, and the active swimming of the mesopelagic fishes may also play an important role.

A New Method for Ionospheric Tomography and Its Assessment by Ionosonde Electron Density, GPS TEC, and Single-Frequency PPP

A new tomographic method was developed with the main goal of mapping the ionosphere in the region of Brazil. The ionospheric background was estimated based on ionosonde and radio-occultation measurements to overcome the lack of data provided by climatological models in low-latitude regions. A new method of performing iterations of the conventional multiplicative algebraic reconstruction technique (MART) was also used in order to avoid nonilluminated cells and improve the spatial resolution. The quality assessment using independent ionosonde data during two weeks in 2013 showed a better performance of the proposed method in comparison to the international reference ionosphere, providing improvements of 31% for the F-layer peak height ${h}_{m}$ and 24% for the ionospheric peak of electron density ${N}_{m}$ . The tomographic technique was also evaluated in the estimation of the total electron content (TEC) and in the single-frequency precise point positioning (PPP). Improvements of 59% in TEC and 31% in the single-frequency PPP were obtained in comparison to the results derived from global ionospheric maps. In addition, a better daily description of the ionosphere was obtained using the proposed method, where it was possible to detect the peak height increasing associated with the prereversal enhancement of the vertical plasma drift that occurs near sunset hours. The results reveal that the modified form of the MART tomographic technique can be considered a useful tool for technical and scientific communities involved in space weather, spatial geodesy, and telecommunications.

Pattern of Ionization Gradient, Solar Quiet Magnetic Element, and F2‐Layer Bottomside Thickness Parameter at African Equatorial Location

AbstractThe study of ionization gradient (dN/dh) profile in the description of ionospheric dynamics is not common. This is the first attempt at finding the dependence of ionization gradient, solar quiet component (Sq (BH)), and bottomside thickness parameter (B0) in the African equatorial sector. Digisonde and Magnetic Data Acquisition System data collocated at an equatorial location were employed. Result was presented for sunrise (00 LT), midday (12 LT), sunset (18 LT), and midnight (00 LT) hours. The ionization gradient peak height remains unchanged at midday across all months. A percentage correlation of 93% existed in the inverse and direct linear relationship of dN/dh‐B0 at sunrise, and of Sq (BH)‐B0 at midday, respectively. Significant relationship between dN/dh and Sq (BH) was at sunset; for other hours, the relationship is poor. The multiple linear relationship of dN/dh‐Sq (BH)‐B0 parameters revealed that the dependence of dN/dh on Sq (BH) and B0 is highest at midday, and a model equation was presented. The dependence of dN/dh on the solar activity index (F10.7) holds at all the selected hours, and distinct only at midday and midnight for the Sq (BH)‐F10.7 and B0‐F10.7 patterns. Both the peak ionization gradient and the height it occurs maximizes/minimizes at 18 LT/06 LT. The importance of the F region dynamo at heights above 150 km was reported.

Features of horizontal magnetic field intensity over northern island of Malaysia

This study utilized magnetic field records of the horizontal component obtained from magnetic data acquisition system at northern island of Malaysia to delineate the diurnal variations of SqH and their monthly mean MSqH for a period of 4 years. The results show that for the entire period of study, the daytime SqH amplitudes increase from $$\sim 20$$ to $$\sim 160$$ nT and their MSqH amplitudes increased from $$\sim 40$$ to about 135 nT in 2008 to 2013, respectively. These variabilities of SqH and MSqH reached peak amplitudes between 10:00 and 12:00 LT hrs. The standard deviation fairly responds to the daily variability of SqH with a phase shift in January 2008 and 2013 which may likely have connection to the sudden stratospheric warming event that occurred in these months. We observed the extension of eastward field that continued beyond the sunset (18:00 LT) hours is more prevalent with higher magnitudes during the deep minimum solar activity and the probable causes are discussed. The observed counter equatorial electrojet associated with late reversal of night-time westward electric field (WEF) shows inverse relationship with increasing solar activity and those that are not associated to late reversal of night-time WEF seems to indicate linear relationship exception of deep minimum solar activity year (2008). We also observed a gradual shift of ECEJ to the morning sector with increasing solar activity. Throughout the years, days with stronger morning counter equatorial electrojet magnitudes generally weaken the expected strong eastward current and shifted its peak to earlier local time. The annual and seasonal variations of SqH show semiannual variation with equinoctial maxima and solstitial minima. About 40% of the SqH shows positive night-time to pre-sunrise variations which suggest the existence of weak electric currents not necessarily of ionospheric origin with appreciable influence at this longitude sector. The extension of eastward field beyond the sunset hours suggests likely modification of the evening side ionosphere over this region.

An experimental investigation on solar powered solid desiccant air conditioning (SPSDAC) based on regenerative evaporative cooling system with PCM unit

ABSTRACT A solar powered solid desiccant air conditioning (SPSDAC) with PCM unit was explored for cooling purposes for the duration of sunlight and sunset hours. Two unique modes of the indirect evaporative cooler (IEC) was adopted during the operation of the SPSDAC. During mode-1, the water circulated through the copper coil and annular space of the hollow circular pipe was vacant. Whereas in mode-2, the water circulates through copper coil and annular space. It was concluded that COP of the system is more than the exergy efficiency and exergy efficiency varied from 1.83% to 1.99%. The desiccant wheel thermal effectiveness (28.81% and 46.06%) is lower than the indirect and direct evaporative cooler effectiveness. The setup under mode-2 is advantageous as compared to mode-1. The pay back time of the setup is 23.2 months. The mean overall thermal storage capacity of the system in mode-1 is 1796.1 W whereas in mode-2 is 1817.7 W.

An introduction to equatorial electrodynamics and a review of an additional layer at low latitudes

This paper presents a review of the progress in the understanding of an additional layer in the low latitude ionosphere, the F3 layer. A brief introduction to the daytime equatorial electrodynamics required for understanding the formation of F3 layer and formation of the usual ionospheric regions and layers are also included for continuity. Numerous papers on various aspects of F3 layer and topside ledge (F3 layer in the topside ionosphere) were published by different research groups using observations and modelling. The first time observations and important new aspects are highlighted and areas for further studies are suggested in this review. The important new aspects include an automated procedure for identifying F3 layer, global map of F3 layer and its longitudinal wave structure, solar activity variation of F3 layer and its long term trend, F3 layer in TEC, F3 layer at sunrise and sunset hours, simultaneous observations of F3 layer and upward ExB drift velocity, simultaneous observations of F3 layer in conjugate summer and winter locations, rapid ascend of F3 layer during geomagnetic storms as an indicator of eastward prompt penetration electric field and mechanism of F4 layer. Main points are summarized at the end.

Design, evaluation and heat transfer analysis of novel forced draft paddy straw bale combustor using heat sink pipe networks for greenhouse heating

In this study, first of its kind novel design of forced draft paddy straw bale combustor (FDPSBC) coupled with innovative pilot fuel injection system (PFIS) and furnace embedded internal water heat-exchanger for large scale water heating is presented. PFIS is optimized to spray 1.5 ml of diesel after every 3 min interval to achieve complete combustion of the compressed bale by maintaining the flame sustainability. Stainless steel heat-exchanger has 62 L water holding capacity circulating at the rate of 36 L per min using the heat of flue gas and has the capacity to heat 1000 L of water from 30 °C to 65 °C within three hours. Heat of combustion (>90% combustion efficiency) was utilized to generate flue gas at 350 °C and hot water above 65 °C applied to 100 m2 area greenhouse heating located at Punjab Agricultural University, Ludhiana (30.56°N), Punjab, India by designing two heat sink pipe networks; flue gas heat sink pipe network (FGHSPN) fabricated with galvanized iron (GI) and hot water heat sink pipe network (HWHSPN) fabricated with mild steel (MS) respectively laid inside the greenhouse for transfer of heat by radiation and free convection modes. Developed mathematical models showed that FGHSPN was able to transfer 9.6 kW (74%) and where as HWHSPN could transfer 3.38 kW (26%) of heat respectively out of the total heat (12.98 kW) transferred by both the networks to maintain the greenhouse air temperature 10 °C higher than the ambient air temperature after sunset hours as validated by experimental trials conducted in the month of November 2017. Installation cost of FDPSBC technology is Rs 5,00,000 ($8000) and with 24 h continuous operation, it can save about 80 kWh per day and can recover the 50% of installation and operating costs within five years time besides managing about 27% of the total paddy straw available in the state of Punjab (India) through useful heating applications including greenhouse heating.