Solar radiation on domed roofs

Solar radiation received and absorbed by four domed roofs was estimated and compared with that of a flat roof. The domed roofs all had the same base areas, and equal to that of the flat roof. One of the roofs considered was the dome of the St. Peter's Church in Rome. Compared with the other roofs considered, this dome had a higher aspect ratio. It was found that all domed roofs received more solar radiation than the flat roof. Considering glazed tiles to cover a selected dome in Iran and the dome of the St. Peter's Church, it was found that the solar radiation absorbed by these roofs is reduced appreciably. In the case of the dome of St. Peter's Church, the amount of radiation absorbed was roughly equal to that absorbed by the comparable flat roof in the warm months. In the case of the glazed reference dome located in Yazd, Iran (a city with very high solar radiation), the radiation absorbed was less than that of flat roof at all times. In addition to aesthetics, this may be a reason for employing glazed tiles to cover the domes of all mosques, shrines, and other large buildings in Iran.     

Solar photo-Fenton degradation of nalidixic acid in waters and wastewaters of different composition. Analytical assessment by LC-TOF-MS

This work assessed the solar photo-Fenton degradation of nalidixic acid (NXA), a quinolone antibacterial agent, in several different aqueous solutions. It has been proven that the composition of the water clearly affects the efficiency of the photo-Fenton process. The presence of chlorine ions induces the concurrence of different mechanisms involving Cl and Cl₂⁻ radicals, which slow down the process. Up to 35 transformation products (TPs) were identified and their structures characterized by accurate LC-TOF-MS mass measurements during treatment of the different model waters. Photocatalytic degradation was thus observed to proceed mainly through the attack of the hydroxyl radicals on the double bond C₍₂₎C₍₃₎ which induce further ring opening. All the TPs identified persisted after total degradation of NXA. NXA in real pharmaceutical effluent was treated by photo-Fenton as a first stage before biological treatment. As NXA has been demonstrated to be recalcitrant to biological treatment, photo-Fenton treatment of the effluent was continued until its total degradation. Although NXA was efficiently degraded, LC-MS analyses demonstrated that some of the TPs identified after the photo-Fenton treatment were also recalcitrant to biological treatment, persisting after the combined treatment. These results show that analytical assessment of photocatalytic water treatments is essential to assure they are functioning as intended.     

Solar radiation and cooling load calculation for radiant systems: Definition and evaluation of the Direct Solar Load

The study of the influence of solar radiation on the built environment is a basic issue in building physics and currently it is extremely important because glazed envelopes are widely used in contemporary architecture.In the present study, the removal of solar heat gains by radiant cooling systems is investigated. Particular attention is given to the portion of solar radiation converted to cooling load, without taking part in thermal absorption phenomena due to the thermal mass of the room. This specific component of the cooling load is defined as the Direct Solar Load.A simplified procedure to correctly calculate the magnitude of the Direct Solar Load in cooling load calculations is proposed and it is implemented with the Heat Balance method and the Radiant Time Series method.The F ratio of the solar heat gains directly converted to cooling load, in the case of a low thermal mass radiant ceiling, is calculated for different kinds of office rooms with a large glazed external surface. An example of cooling load calculation developed with the proposed procedure is given.     

Prediction model of the radiation from ground surface to the occupant in outdoor space

The outdoor ground radiation including the emitted radiation and reflected radiation plays an important role in the outdoor thermal environment. In this paper, based on the hypothesis of that the occupant body can be equivalent to a human cylinder and the outdoor ground surface is diffusive for radiation, a mathematical model is advanced to describe the radiation from the ground surface to the occupant. Through theoretical analysis of the mathematical model, general formulas for calculating the radiation arriving at the occupant from an annular ground surface and infinite ground surface are obtained. It shows that, the radiation from ground surface to the occupant depends on the surface temperature, reflectivity and emissivity, the arrange within the radius of 8.0m encircling the occupant can be defined as the dominant radiating area which radiates 90% radiation to the occupant. The radiative potentials of different pavement surface such grass, asphalt concrete surface, granite slab surface, terracotta bricks, colored concrete interlocking blocks are also compared with the datum measured by Tan Slew-Ann and Fwa Tien-Fang in Singapore, it shows that, in the summer sunny day, grass surface radiates more radiation in the morning but less in the afternoon than other pavement materials. Finally, discussions of reducing the radiation of outdoor ground surface are presented and main conclusions are drawn for improving the outdoor thermal environment.     

Evaluation of the effectiveness and safety of the thermo-treatment process to dispose of recombinant DNA waste from biological research laboratories

The discharge of recombinant DNA waste from biological laboratories into the eco-system may be one of the pathways resulting in horizontal gene transfer or "gene pollution". Heating at 100 degrees C for 5-10 min is a common method for treating recombinant DNA waste in biological research laboratories in China. In this study, we evaluated the effectiveness and the safety of the thermo-treatment method in the disposal of recombinant DNA waste. Quantitative PCR, plasmid transformation and electrophoresis technology were used to evaluate the decay/denaturation efficiency during the thermo-treatment process of recombinant plasmid, pET-28b. Results showed that prolonging thermo-treatment time could improve decay efficiency of the plasmid, and its decay half-life was 2.7-4.0 min during the thermo-treatment at 100 degrees C. However, after 30 min of thermo-treatment some transforming activity remained. Higher ionic strength could protect recombinant plasmid from decay during the treatment process. These results indicate that thermo-treatment at 100 degrees C cannot decay and inactivate pET-28b completely. In addition, preliminary results showed that thermo-treated recombinant plasmids were not degraded completely in a short period when they were discharged into an aquatic environment. This implies that when thermo-treated recombinant DNAs are discharged into the eco-system, they may have enough time to re-nature and transform, thus resulting in gene diffusion.     

混凝土表面太阳辐射吸收率试验研究

混凝土对太阳辐射的吸收率直接影响混凝土结构内温度场分布以及温度效应。由于混凝土材料的物理力学性能离散性大,施工条件多样,使用环境千差万别,目前尚无对太阳辐射吸收率研究的系统而成熟的成果。结合太阳能利用原理和热工规范等,对不同颜色、不同粗糙度混凝土表面,进行太阳辐射吸收率的探索性试验,初步提出在考虑温度作用的混凝土结构设计中,其表面太阳辐射吸收率的建议取值。     

Multi-step-ahead forecasting of daily solar radiation components in the Saharan climate

ABSTRACT

Accurate estimation of renewable energy sources plays an important role in their integration into the grid. An unexpected atmospheric change can produce a range of problems related to various solar plant components affecting the electricity generation system. Global solar radiation (GSR) assessment has been increased in the past decade due to its important use in photovoltaic application. In this paper, we propose the use of machine learning-based models for daily global and direct solar radiation forecasting in a semi-arid climate, using a combination set of meteorological parameters on a horizontal surface in the Ghardaïa region. The models are presented and implemented on 3-year measured meteorological data at Applied Research Unit for Renewable Energies (URAER) at Ghardaïa city between 2014 and 2016. The results show that both MLP and RBF models perform well for three-step-ahead forecasting with a slight improvement in MLP models in terms of statistical metrics.     

Mixtures of zinc and phosphate affect leaf litter decomposition by aquatic fungi in streams

To better understand the impacts of multiple stressors in freshwaters, we investigated the effects of mixtures of zinc and inorganic phosphorus on microbial decomposition of leaf litter. Alder leaves were colonized in a stream and placed in microcosms with stream water supplemented or not with 3 concentrations of zinc (Zn up to 9.8 mg/l) or phosphate (P-PO₄³⁻ up to 0.5 mg/l), alone and in all possible combinations. We measured leaf mass loss, and fungal biomass, reproduction and diversity. In control microcosms, 23 species of aquatic hyphomycetes were identified on leaves, and the exposure to the highest zinc concentration reduced diversity to 14 species. Articulosporatetracladia was the dominant species followed by Flagellospora sp. and Alatosporaacuminata. The exposure to phosphate increased the contribution of A.acuminata, but this species was negatively affected by zinc. Under high zinc stress, Varicosporiumelodeae increased its contribution to the total conidial production.The exposure to high zinc concentration, alone or in mixtures with phosphate, led to shifts in fungal community structure, as indicated by cluster analysis based on sporulation data and denaturing gradient gel electrophoresis (DGGE) fingerprints of fungal DNA. These changes were accompanied by a reduction in leaf decomposition, particularly in mixtures with high Zn concentration, in which leaf mass loss was 30% lower than in the control. This suggests that the co-occurrence of zinc and phosphate may have negative effects on stream ecosystem functioning. However, we did not detect decreased leaf-associated fungal biomass and sporulation, probably because a delay in fungal colonization occurred due to the presence of stressors.     

Solar disinfection (SODIS): simulation of solar radiation for global assessment and application for point-of-use water treatment in Haiti

Haiti and other developing countries do not have sufficient meteorological data to evaluate if they meet the solar disinfection (SODIS) threshold of 3-5 h of solar radiation above 500 W/m2, which is required for adequate microbial inactivation in drinking water. We have developed a mathematical model based on satellite-derived daily total energies to simulate monthly mean, minimum, and maximum 5-h averaged peak solar radiation intensities. This model can be used to assess if SODIS technology would be applicable anywhere in the world. Field measurements were made in Haiti during January 2001 to evaluate the model and test SODIS efficacy as a point-of-use treatment option. Using the total energy from a measured solar radiation intensity profile, the model recreated the intensity profile with 99% agreement. NASA satellite data were then used to simulate the mean, minimum, and maximum 5-h averaged peak intensities for Haiti in January, which were within 98.5%, 62.5%, and 86.0% agreement with the measured values, respectively. Most of the discrepancy was attributed to the heterogeneous nature of Haiti's terrain and the spatial resolution of the NASA data. Additional model simulations suggest that SODIS should be effective year-round in Haiti. Actual SODIS efficacy in January was tested by the inactivation of total coliform, E. coli, and H2S-producing bacteria. Exposure period proved critical. One-day exposure achieved complete bacterial inactivation 52% of the time, while a 2-day exposure period achieved complete microbial inactivation 100% of the time. A practical way of providing people with cold water every morning that has undergone a 2-day exposure would be to rotate three groups of bottles every morning, so two groups are out in the sun and one is being used for consumption.     

Occurrence and fate of organophosphorus flame retardants and plasticizers in urban and remote surface waters in Germany

Within this study, concentration levels and distribution of the organophosphates tris(2-chloroethyl) phosphate (TCEP), tris(2-chloro-1-methylethyl) phosphate (TCPP), tris(2-butoxyethyl) phosphate (TBEP), tri-iso-butyl phosphate (TiBP), and tri-n-butyl phosphate (TnBP) were investigated at nine lentic surface waters under different anthropogenic impact between June 2007 and October 2009. Furthermore, the possibility of in-lake photochemical degradation of the analytes was studied in laboratory experiments using spiked ultrapure water and lake water samples incubated in Teflon bottles (which transmit sunlight). TBEP, TiBP, and TnBP were photochemically degraded in spiked lake water samples upon exposure to sunlight. Organophosphate concentrations in the more remote lakes were often below or close to the limits of quantification (LOQ). TCPP was the substance with the highest median concentration in rural volcanic lakes (7-18 ng L⁻¹) indicating an atmospheric transport of the compound. At urban lakes their median concentrations were in the range of 23-61 ng L⁻¹ (TCEP), 85-126 ng L⁻¹ (TCPP), <LOQ-53 ng L⁻¹ (TBEP), 8-10 ng L⁻¹ (TiBP), and 17-32 ng L⁻¹ (TnBP). High variability but no significant seasonal trends were observed for all five organophosphates in urban lake water samples.     

Study on the thermal behavior of aluminum reticulated shell structures considering solar radiation

The aluminum dome has been more and more widely adopted in industrial and civil buildings, and the span is up to 140 m. Because the thermal expansion coefficient of aluminum with a value of 2.3×10⁻⁵ is almost two times than that of steel, the temperature change will induce significant thermal deformation and thermal stress, especially for the large span aluminum domes under solar radiation. In this paper, the solar radiation absorption coefficient was firstly measured using spectrophotometer, and then a numerical simulation method was presented and verified by test dada. To take a aluminum dome project with a span of 125 m for an example, the non-uniform temperature distribution and change under solar radiation were analyzed using the presented method, and following conclusions were obtained: (1) The thermal load is the key load for the aluminum domes, and the solar radiation has a significant effect on the thermal behavior of the aluminum domes. Therefore, the non-uniform thermal load considering solar radiation has to be considered in the future design. (2) There is a remarkable variation of member stress, and it is necessary to study the fatigue behavior of the aluminum domes under solar radiation.     

Heat transfer modelling on windows and glazing under the exposure of solar radiation

Due to the effect of solar radiation on windows and glazing system the evaluation of heat flow is of primary importance in modeling the thermal performance within building interiors to account thermal comfort and overall energy consumption of a building. In this context the optical properties of window glazing are measured to determine the percentage absorption of incident solar radiation. An experimental study was performed in a room to measure the glazing surface temperature due to the global radiation on it. The corresponding window plane global radiation and horizontal global radiation were measured outside for simulation. Mathematical models have been developed to simulate the window plane solar radiation and corresponding glazing surface temperature aiming at validating the measured values. The thermal model is concerned with laminar heat transfer for natural and forced convection process according to the ambient conditions. The estimated errors between experimental and simulated values of window plane radiation and glazing temperature are shown to be within ±5%. Using the developed thermal model the heat flow inside the room through windows is determined. Thus overall heat transfer coefficient of glazing (U-factor) and the Solar Heat Gain (SHG) of building interior have been predicted from the simulation.     

高原寒冷地区太阳辐射对室内热环境影响

以拉萨地区某多层办公建筑为研究对象,对供暖期测试日(全天晴朗、晴转阴)逐时太阳辐射强度模拟计算,对测试日室外温度、风速进行实测。分析太阳辐射对测试房间(分别选取南向房间2间,北向房间2间,其中1间南向测试房间不供暖)室内温湿度的影响。结合实测结果,对拉萨地区供暖系统、建筑的优化设计提出建议。     

Reconnaissance of selected PPCP compounds in Costa Rican surface waters

Eighty-six water samples were collected in early 2009 from Costa Rican surface water and coastal locations for the analysis of 34 pharmaceutical and personal care product compounds (PPCPs). Sampling sites included areas receiving treated and untreated wastewaters, and urban and rural runoff. PPCPs were analyzed using a combination of solid phase extraction and liquid chromatography tandem mass spectrometry. The five most frequently detected compounds were doxycycline (77%), sulfadimethoxine (43%), salicylic acid (41%), triclosan (34%) and caffeine (29%). Caffeine had the maximum concentration of 1.1 mg L⁻¹, possibly due to coffee bean production facilities upstream. Other compounds found in high concentrations include: doxycycline (74 μg L⁻¹), ibuprofen (37 μg L⁻¹), gemfibrozil (17 μg L⁻¹), acetominophen (13 μg L⁻¹) and ketoprofen (10 μg L⁻¹). The wastewater effluent collected from an oxidation pond had similar detection and concentrations of compounds compared to other studies reported in the literature. Waters receiving runoff from a nearby hospital showed higher concentrations than other areas for many PPCPs. Both caffeine and carbamazepine were found in low frequency compared to other studies, likely due to enhanced degradation and low usage, respectively. Overall concentrations of PPCPs in surface waters of Costa Rica are inline with currently reported occurrence data from around the world, with the exception of doxycycline.     

被动式建筑热环境调节策略分析——2013年中国国际太阳能十项全能竞赛评述

热环境调节策略是创造舒适建筑环境的关键所在,也是建筑节能设计的重点.以2013年中国国际太阳能十项全能竞赛（SDC2013）中的零能耗太阳能住宅建筑为例,对各参赛建筑中较为新颖的被动式热环境调节策略进行分析,剖析其技术特点,探讨太阳能住宅中热环境调节的新技术及其应用方法,希冀对当代绿色建筑设计起到借鉴作用.     

Diffusion of Solar Energy Use in the Built Environment Supported by New Design

Places of large potentials of sustainable energy production and places of large energy consumption are often very different and separated by large distances across the globe. This paper first discusses potentials of solar technology in terms of global availability using PV （photovoltaic） technology and actual energy production. Solar energy is widely under-used and one way to reduce this is to improve production in low-energy places with high demand： large cities. According to this option, about 40% of the electricity consumption in the built environment could be produced by solar PV systems and energy storage systems. This paper discusses conditions in the built environment and functional and design qualities enabling an increased diffusion of the technologies In a comparative analysis of PV technologies, the criteria taken into account encompass efficiency of the type of solar cell and commercial availability. Special attention is paid to the design features of different PV systems, like flexibility, colour and transparency that might help in their utilization as integrated in building material and ornaments in modem architecture. The same procedure is followed for electricity storage devices. The preliminary conclusion is that at present the freedom of design is largest for a combination of crystalline silicon PV cells and Li-ion batteries.     

The 24-h unsteady analysis of air flow and temperature in a real city by high-speed radiation calculation method

Heat island phenomenon is an important issue in environmental studies. Many studies involving observations and simulations have been performed. Computational Fluid Dynamics (CFD) analysis including the effects of solar radiation and longwave radiation heating/cooling are limited in the extreme conditions at midday, when solar radiation intensity are at maximum; and the 24-h unsteady analyses are not done due to the difficulties of the boundary conditions. Authors developed Computer Graphics (CG) method for calculating solar radiation and longwave radiation with high speed, and developed the 24-h unsteady analytical method from the data calculated by Weather Research and Forecasting (WRF). The integrated CFD was applied to the real city. The results showed that the integrated CFD was the useful tool to analyze the heat island phenomena.     

防核辐射混凝土高温稳定性能试验研究

利用综合热分析仪、热膨胀仪、X射线衍射仪及扫描电镜,通过测试防核辐射混凝土中水泥石的热分解过程、高温矿物组成变化、热膨胀性能、高温后抗压强度变化,砂浆的热膨胀性能和混凝土高温后微观形貌变化及抗压强度变化,研究了防核辐射混凝土的高温热稳定性能。结果表明,经700℃高温后,水泥石中C-S-H凝胶网状结构出现破碎,数量减少,其主要矿物组分为CaO、Ca(OH)2、C3S和β-C2S,集料与水泥石界面结构松散,并出现裂纹;40～600℃过程中,水泥石和砂浆呈先膨胀后收缩的变化趋势,且水泥石的热膨胀系数远大于砂浆。     

On the influence of boundary conditions and thermal radiation on predictive accuracy in numerical simulations of indoor ventilation

Room ventilation is a well studied field, whereby ventilation is either mechanically driven or reliant on buoyancy forces driven by thermal gradients. In office spaces, where occupant comfort is important, the latter (termed displacement ventilation) is sometimes used. In many existing studies, computational methods used to simulate ventilation cases use a number of general engineering assumptions. These can include neglecting heat transfer through the walls, assuming that internal radiative transfer is negligible, or by modelling radiative sources as additional heat loads. In this study, these assumptions are systematically examined by selectively modelling certain phenomena in the simulations. In this way, the accuracy and suitability of such assumptions can be examined with reference to previous experimental work. The variation of radiative absorptivity upon the vertical temperature profile has also been investigated in order to determine the contribution of thermal re-distribution by surface radiation alone, and in addition to radiative participation from the air.     

Evaluating the influence of process parameters on soluble microbial products formation using response surface methodology coupled with grey relational analysis

Soluble microbial products (SMPs) present a major part of residual chemical oxygen demand (COD) in the effluents from biological wastewater treatment systems, and the SMP formation is greatly influenced by a variety of process parameters. In this study, response surface methodology (RSM) coupled with grey relational analysis (GRA) method was used to evaluate the effects of substrate concentration, temperature, NH₄⁺-N concentration and aeration rate on the SMP production in batch activated sludge reactors. Carbohydrates were found to be the major component of SMP, and the influential priorities of these factors were: temperature > substrate concentration > aeration rate > NH₄⁺-N concentration. On the basis of the RSM results, the interactive effects of these factors on the SMP formation were evaluated, and the optimal operating conditions for a minimum SMP production in such a batch activated sludge system also were identified. These results provide useful information about how to control the SMP formation of activated sludge and ensure the bioreactor high-quality effluent.