A comparative study of temperatures of direct sunlight and air temperatures in a standard screen measured at Doha International Airport - a pilot study

An observational campaign was conducted at Doha International Airport, Arabian Gulf to find out difference between air temperature in a standard screen and direct sunlight. Hourly observations recorded during July-August 1998 and June-August 1999 formed the basis of the study. Difference between screen temperature (ST) and outside temperature (OT) in respect of all hourly data in the above period from 0600 to 1800 hrs of local time have been computed and analysed. In order to examine the difference before sunrise and after sunset, observations were also made during 1900-0500 hrs of local time from 1st to 18th of July 1998. Results of the study revealed that the magnitude of the differences between OT and ST is not as high as expected. The highest difference observed was 5.1° C on 16th July 1999 at 0900 hr. As anticipated, the temperature of direct sunlight between 0600 hr and 1700 hr were always higher than the screen temperature. However, after 0500 pm of local time, the screen temperatures are found to be higher than outside temperature though the sunset time in these months are after 0600 pm. The mean difference between ST and DT in June, July and August respectively found to be 1.43° C, 1.53° C and 1.67° C. The highest difference observed in these months was 3.8° C, 5.1° C and 4.1° C respectively. The study has also indicated that the difference between OT and ST is generally higher during 0900-1000 hrs of local time and lower during two hours before sunrise and sunset.

Effects of some management factors (Housing condition and watering regimen) on blood parameters of desert goats

This study aimed to assess the effects of housing condition and watering regimen on some blood parameters during the period May 2018- February 2019. Desert goat Package Cell Volume% (PCV %) were highest during January, February and lowest during May, and August. Goats had the highest (P<0.001) blood Hemoglobin (Hb%) during May and July with very slight fluctuations throughout the seven months of the experimental period. Goats under shade had comparatively higher PCV% and slightly lower Hb% in comparison with those under direct sunlight. Plasma Calcium was low during February and January and rose during December with higher levels during May, June and July. Goat plasma phosphorus concentrations followed an opposite picture being highest (P<0.01) during October, December, and February and lowest (P<0.01) during other months. Plasma Calcium (Ca) and Phosphorus (P) concentrations were slightly (P>0.05) higher for goats under shade compared with those under direct sunlight. The main effects of months on blood metabolites were highly significant (P<0.01). The highest goat blood protein was during, June-July and lowest (P<0.01) during other months. Goat blood albumen levels were highest (P<0.001) for August- September- October and lowest for January- February whereas blood glucose levels were highest (P<0.01) during January- February and with very slight fluctuations throughout the seven months of the experimental period. Blood protein, blood albumin and blood glucose levels were relatively higher (P>0.05) for goats under shade compared with those under direct sunlight. Goats watered everyday had slightly lower blood protein and albumin and slightly higher blood glucose in comparison with goats watered every other day.

Graphitic Carbon Nitride as a Sustainable Photocatalyst Material for Pollutants Removal. State-of-the Art, Preliminary Tests and Application Perspectives

Photocatalysis is an attractive strategy for emerging pollutants remediation. Research towards the development of new, efficient and effective catalytic materials with high activity under wide irradiation spectra is a highly active sector in material science. Various semiconductor materials have been employed as photocatalysts, including TiO2, SrTiO3, CdS, BiVO4, Ta3N5, TaON, Ag3PO4, and g-C3N4. The latter is a metal-free, low cost polymer, providing high adsorption and catalytic properties, shown to be promising for photocatalysis applications under visible light. Furthermore, g-C3N4 composites are among the most promising advanced photocatalytical materials that can be produced by green synthesis processes. In this paper, the state-of-the-art of g-C3N4 applications is reviewed, and application perspectives are discussed. Photocatalysis tests with g-C3N4 under Xenon irradiation were performed to gather first-hand information to improve photoreactor design. Xenon light spectrum appears to be a suitable radiation source to replace direct sunlight in engineered pollutants removal processes catalyzed by g-C3N4, in lieu of other currently used heterogeneous photocatalysis processes (e.g., TiO2-UV). LED sources are also very promising due to higher energy efficiency and customizable, catalyzer-specific irradiation spectra.

An evaluation for the medium-term storage and viability of root cortex tissues stained with blue ink in the assessment of arbuscular mycorrhizal fungi

Sheaffer blue ink is an effective method to stain arbuscular mycorrhizal (AM) fungi in a variety of plant species. It has, however, received criticism for its potential rapid degradation and short-term viability. The long and medium term storage and viability of stained samples has not, to date, been described for this particular staining method. This short communication reports on the viability of 730 samples stained with Sheaffer blue ink stored for the duration of 4 years in microscope slide boxes out of direct sunlight. There was no significant difference in micrograph image quality and presence of stain between years as indicated by the number of AM fungal structures quantified. In conclusion Sheaffer blue ink stain does not deteriorate in the medium term.

Smart Design of Portable Indoor Shading Device for Visual Comfort—A Case Study of a College Library

With the development of architectural technology, the use of floor-to-ceiling windows has emerged widely. The ensuing problem is that more and more students and office workers are suffering from direct sunlight while working in specific areas. Based on the pain points of the working process, this study designed a portable product for improving visual comfort through field research and environment simulation. It provided a new personalized design for blocking direct sunlight from the working area using a portable and liftable sunshade curtain, allowing the users to control the height and angle of the sunshade curtain through a mobile phone application. It can also adjust itself according to environmental parameters collected by sensors, so as to block sunlight in certain areas. A simulation based on the design features and the light environment of a library is run, proving the model effective in improving these aspects. The study aimed to provide solutions for indoor visual comfort and suggestions for future indoor household designs.

Highly suppressed solar absorption in a daytime radiative cooler designed by genetic algorithm

Here, we report a selective multilayer emitter for eco-friendly daytime passive radiative cooling. The types of materials and thickness of up to 10 layers of the multilayer structure are optimized by a genetic algorithm. The passive radiative cooler is designed to mainly target low solar absorption, which allows sub-ambient cooling under direct sunlight. We used a custom objective function in the solar region to achieve high-performance daytime radiative cooling to minimize solar absorption. The designed structure minimizes solar absorption with an average absorptivity of 5.0% in the solar region (0.3–2.5 μm) while strongly emitting thermal radiation with an average emissivity of 86.0% in the atmospheric transparency window (8–13 μm). The designed and fabricated structure achieves daytime net cooling flux of 84.8 W m−2 and 70.6 W m−2, respectively, under the direct AM 1.5 solar irradiation (SI) (total heat flux of 892 W m−2 in the 0.3–2.5 μm wavelength region). Finally, we experimentally demonstrate a passive radiative cooling of the fabricated selective emitter through a 72-hour day-night cycle, showing an average and maximum temperature reduction of 3.1 °C and 6.0 °C, respectively. Our approach provides additional degrees of freedom by designing both materials and thickness and thereby is expected to allow high-performance daytime radiative cooling.

Assessment of Deterioration Risk of Maijishan Grotto under the Radiation Difference Based on Heat and Moisture Transfer Model

The ambient environment of architectural heritage is an important factor affecting its conservation. Two adjacent rows of Buddha statues in Grottoes No. 3 (semi-open) of Maijishan Grotto in Gansu, China, show apparent differences in the degree of deterioration. This study made a monitoring scheme of grottoes microenvironments such as air temperature, relative humidity, radiation, and surface temperature to explore the cause of the difference. A two-dimensional heat and moisture (HAM) transfer model was established and verified to simulate the temperature and humidity on the surface and inside of the Buddha statues. Then, temperature and water content fluctuation and the risks of thermal stress destruction on the surface and near the surface of the Buddha statues were evaluated. The results show that the radiation difference causes thermal stress and water content differences both in heights and in depths. This impact brought by the direct sunlight may contribute to the different deterioration on the two rows of Buddha statues. The eaves shaded the upper row of the Buddha statues much longer than the lower ones. Less severe fluctuation and differences in temperature and water content occur at the middle and upper points. This study evaluates the degradation of Grottoes No. 3 and has guiding significance for its preservation methods.

Direct Sunlight driven photocatalytic degradation of hazardous organic dyes using TiO2-NiO nanocomposite p-n junction

TiO2 is stable and nontoxic, an effective, low cost, semiconductor photo catalyst to degrade most of the organic pollutants. Nevertheless, the practical application of TiO2 are limited due to two important reasons, while one of the reasons is rapid recombination of electron and hole pair and other one is larger band gap 3.2ev, which permits to absorb 3-4% of solar energy. To enhance photocatalytic activity, several TiO2-metal oxide composites have been used. Due to their electron hole separation ability p-n junction, type semiconductor has become more focused in the last few years. TiO2-NiO nanocomposite is one such catalyst; the presence of NiO facilitates the separation of the hole and the electron pair and encourages the interfacial charge transfer; which facilitates TiO2-NiO a good photocatalyst under direct sunlight. The objective of the study is to synthesise nanocomposite of different mole ratios of NiO and TiO2, to investigate the physicochemical properties such as XRD for phase and purity test, SEM –EDX for morphology and percentage elemental composition, UVDRS for band gap analysis. Photocatalytic activity of TiO2-NiO p-n junction nano structures experiments were carried out under direct sunlight in different systems; using aqueous solution of the dye with effect of pH, concentration of dye, catalyst loading and time on degradation of the organic dye were studied. With increasing the concentration of NiO in to TiO2-NiO composite increases the photocatalytic activity due to narrowing of the band gap attributed to interfacial charge transfer or higher hole mobility.