Incoming Radiation Research Articles

Examining the Impact of Intermediate Cooling on Mechanical Properties of 22MnB5 in a Tailored Tempering Process

Tailoring the properties of hot-stamped components offers the potential to enhance crash performance while simultaneously improving downstream joining processes. In recent years, an innovative technology suited for achieving tailored properties involving the utilization of a specialized furnace chamber, known as the TemperBox®, has been introduced. Within this chamber, a cooled aluminum mask shields specific areas of the blank from incoming heat radiation and concurrently absorbs the blank’s own radiation. The duration of the heat radiation exchange can influence the diffusion-dependent phase transformation and, consequently, the resulting mechanical properties. Hence, the intermediate cooling duration assumes a pivotal role as a parameter, as is investigated in this study. To examine the effects, specimens of the steel 22MnB5 AS150 are subjected to intermediate cooling of varying durations, followed by forming and partial quenching. The temperature profile of the blank during intermediate cooling prior to forming and quenching is analyzed. Subsequently, the tailored hot-stamped components are assessed for hardness, strength, ductility, and thickness strain. The study reveals that with increasing duration of partial intermediate cooling and targeted radiation exchange, a homogeneous ferritic–pearlitic structure is formed from an austenitic structure. This uniform structure of ferrite and pearlite is reflected in lower hardness and strength values, along with improved ductility. Additionally, this paper introduces a simulation methodology designed to calculate the dynamics of thermal radiation and the kinetics of phase transformation.

Biophysical warming patterns of an open-top chamber and its short-term influence on a Phragmites wetland ecosystem in China

Passive-warming, open-top chambers (OTCs) are widely applied for studying the effects of future climate warming on coastal wetlands. In this study, a set of six OTCs were established at a Phragmites wetland located in the Yellow River Delta of Dongying City, China. With data collected through online transmission and in-situ sensors, the attributes and patterns of realized OTCs warming are demonstrated. The authors also quantified the preliminary influence of experimental chamber warming on plant traits. OTCs produced an elevated average air temperature of 0.8°C (relative to controls) during the growing season (June to October) of 2018, and soil temperatures actually decreased by 0.54°C at a depth of 5 cm and 0.46°C at a depth of 30 cm in the OTCs. Variations in diel patterns of warming depend greatly on the heat sources of incoming radiation in the daytime versus soil heat flux at night. Warming effects were often larger during instantaneous analyses and influenced OTCs air temperatures from −2.5°C to 8.3°C dependent on various meteorological conditions at any given time, ranging from cooling influences from vertical heat exchange and vegetation to radiation-associated warming. Night-time temperature depressions in the OTCs were due to the low turbulence inside OTCs and changes in surface soil-atmosphere heat transfer. Plant shoot density, basal diameter, and biomass of Phragmites decreased by 23.2%, 6.3%, and 34.0%, respectively, under experimental warming versus controls, and plant height increased by 4.3%, reflecting less carbon allocation to stem structures as plants in the OTCs experienced simultaneous wind buffering. While these passive-warming OTCs created the desired warming effects both to the atmosphere and soils, pest damages on the plant leaves and lodging within the OTCs were extensive and serious, creating the need to consider control options for these chambers and the replicated OTCs studies underway in other Chinese Phragmites marshes (Panjin and Yancheng).©2023 China Geology Editorial Office.

A comparative study of the land–atmosphere energy and water exchanges over the Tibetan Plateau and the Yangtze River Region

A comprehensive understanding of energy and water cycle characteristics in different regions is crucial for studying local land–atmosphere interactions and predicting regional weather and climate change. To explore similarities and differences in land–atmosphere energy and water exchanges between two regions—the Tibetan Plateau (TP), characterized by higher elevation and a drier climate, and the Yangtze River Region (YRR), with lower elevation and a wetter climate—this study analyzed and compared the radiation components and the turbulent heat fluxes at eight sites covering various land-cover types, including alpine desert and alpine grassland on the TP, as well as urban and grassland on the YRR. The following results were obtained: (1) Over the TP, the annual mean incoming and outgoing shortwave radiation are 251.3 and 59.6 W m−2, which are 1.70 and 2.87 times the values in the YRR, respectively. The incoming and outgoing longwave radiation are 231.5 and 338.0 W m−2, which are 0.64 and 0.83 times those in the YRR, respectively. However, the difference in net radiation is relatively small. (2) In grassland over both the TP and YRR, the latent heat fluxes have higher values of 35.0 and 38.8 W m−2, respectively, leading to a higher heating efficiency. Alpine desert has the highest sensible heat flux (SH) value of 42.1 W m−2, due to sparse vegetation and lower soil moisture, followed closely by urban land cover with an average SH value of 38.2 W m−2. These results highlight the different characteristics of land–atmosphere interaction across different land covers in different climatic contexts, laying the groundwork for future investigations of additional land–atmosphere coupling processes.摘要正确认识不同区域能量和水分循环特征是研究局地地气相互作用及准确预测区域天气, 气候变化的关键. 为了研究属于干旱/半干旱气候的青藏高原 (TP) 和湿润/半湿润气候的长江流域 (YRR) 之间地表能量和水分交换的异同, 本文对比分析了两个区域8个不同地表类型 (包括高山荒漠, 高山草地, (平原) 城市和 (平原) 草地等) 观测站点的地表辐射和能量通量数据. 结果显示: (1) TP由于高原大气层稀薄且空气洁净, 年平均入射短波辐射为251.3 W m−2, 是YRR的1.7倍. 加之高原地表反照率高导致反射辐射 (59.6 W m−2) 是YRR的2.87倍. 入射及出射的长波辐射为231.5和338.0 W m−2, 分别为YRR的0.64和0.83. 而两个区域的净辐射差异不大; (2) 草地站更多的潜热释放使得地表总加热效率高于城市和高山荒漠, TP和YRR的草地站的年平均潜热分别为35.0 和 38.8 W m−2, 而植被稀疏且土壤干燥的高山荒漠地区感热最大, 年平均感热为42.1 W m−2; 其次是城市下垫面, 其年平均感热为37.7 W m−2. 研究结果揭示了不同气候背景下典型下垫面地气相互作用特征, 为地气相互作用过程深入分析奠定了基础.

Changes in cloudiness contribute to changing seasonality in the Baltic Sea region

In the Baltic Sea region, a significant increase in solar radiation has been detected during the past half-century. Changes in shortwave irradiance are associated with atmospheric transparency and cloudiness parameters like cloud fraction and albedo. One of the most important reasons for day-to-day changes in cloudiness is the synoptic-scale atmospheric circulation; thus, we look for reasons for solar radiation trends due to changes in atmospheric circulation. We analysed regional time series and trends from satellite-based cloud climate data record CLARA-A2 for the Baltic Sea region in 1982–2018. As the rise in solar radiation depends on the seasonally averaged values of total fractional cloud cover (CFC), surface incoming shortwave radiation (SIS) and occurrences of circulation types were analysed. We show that the shift in seasonality connected to the earlier accumulated sums of SIS is at least partly explained by the changes in synoptic-scale atmospheric circulation.

Classical relativistic electron-field dynamics: Hamiltonian approach to radiation reaction

Motivated by the renewed interest due to the presently available extreme light sources, the dynamics of a single classical relativistic (spinless) extended electron interacting with a classical electromagnetic field (an incoming radiation and the field radiated by the electron) is revisited. The field is treated in Lorentz gauge, with the Lorentz condition. By assumption, there is a crucial finite cut-off k max on the magnitude of any wavevector contributing to the field (preventing a point electron) and, for a simple formulation, the initial conditions for particle and fields are given in the infinitely remote past. In an infinite three-dimensional vacuum and in an inertial system, Hamilton’s dynamical equations for the particle and the complex field amplitudes acting as canonical variables (a's) yield an exact Lorentz force equation for the former, that includes the incoming radiation and an exact radiation reaction force F RR due to the field radiated by the electron. Uniform motion is obtained as a test of consistency. Based upon numerical computations, some approximations on F RR are given. A covariant formulation is also presented.

Projections of central Arctic summer sea surface temperatures in CMIP6

One of the most dramatic climate responses to future global warming is the near-disappearance of the perennial sea ice cover in the central Arctic Ocean, a phenomenon known as the ice-free summer Arctic. The immediate consequence of an ice-free Arctic would be the surface warming of the central Arctic Ocean, where sea surface temperatures (SSTs) used to be at freezing levels. Through an analysis of climate models participating in the climate model intercomparison project phase-6, this study demonstrates a wide range of responses in the central Arctic SSTs in August–September as a result of the projected ice-free summer Arctic. These responses vary from 0.7 to 8 °C in the shared socioeconomic pathway 2 (SSP2-4.5), referred to as the ‘middle of the road’ scenario, in which socioeconomic and technological trends do not significantly deviate from historical patterns. The extent of the central Arctic sea surface warming in August–September is found to have a loose correlation with the September sea ice extent (SIE), but a stronger connection to the SIE during spring to early summer (May–July), when incoming shortwave radiation is most intense. In certain climate models, the perennial sea ice cover disappears completely in September, causing central Arctic SSTs to rise by 5 °C–8 °C by the end of the 21st century. This leads to a bimodal distribution of annual SSTs. Further analysis reveals a close relationship between mid-summer SSTs in the central Arctic Ocean and preceding winter sea ice thickness (SIT). This underscores the significance of winter SIT in predicting future Arctic surface warming and marine heatwaves.

Is tree planting an effective strategy for climate change mitigation?

The world's forests store large amounts of carbon (C), and growing forests can reduce atmospheric CO2 by storing C in their biomass. This has provided the impetus for world-wide tree planting initiatives to offset fossil-fuel emissions. However, forests interact with their environment in complex and multifaceted ways that must be considered for a balanced assessment of the value of planting trees.First, one needs to consider the potential reversibility of C sequestration in trees through either harvesting or tree death from natural factors. If carbon storage is only temporary, future temperatures will actually be higher than without tree plantings, but cumulative warming will be reduced, contributing both positively and negatively to future climate-change impacts. Alternatively, forests could be used for bioenergy or wood products to replace fossil-fuel use which would obviate the need to consider the possible reversibility of any benefits.Forests also affect the Earth's energy balance through either absorbing or reflecting incoming solar radiation. As forests generally absorb more incoming radiation than bare ground or grasslands, this constitutes an important warming effect that substantially reduces the benefit of C storage, especially in snow-covered regions. Forests also affect other local ecosystem services, such as conserving biodiversity, modifying water and nutrient cycles, and preventing erosion that could be either beneficial or harmful depending on specific circumstances.Considering all these factors, tree plantings may be beneficial or detrimental for mitigating climate-change impacts, but the range of possibilities makes generalisations difficult. Their net benefit depends on many factors that differ between specific circumstances. One can, therefore, neither uncritically endorse tree planting everywhere, nor condemn it as counter-productive. Our aim is to provide key information to enable appropriate assessments to be made under specific circumstances. We conclude our discussion by providing a step-by-step guide for assessing the merit of tree plantings under specific circumstances.

Optical absorption driven by efficient refraction and light concentration for photovoltaic applications

Broadband absorption of the solar spectrum is a prerequisite to any photovoltaic technology. Subwavelength arrays are known to provide various mechanisms for broadband and omnidirectional absorption of the solar spectrum. In the current work we examine optical absorption in NP arrays decorated with SiO2 quasi-nanolenses (qNL arrays), which numerically exhibit 10–15 % increase in broadband absorption. Specifically, near-field scanning optical microscopy (NSOM) is employed to probe the underlying optical absorption mechanisms. Two NSOM methods are employed for the investigation: 1) far-field imaging using near-field excitation which allows the determination as to the origin of the reflected far-field photons, and 2) far-field excitation and near-field scanning to measure the lateral optical propagations in the arrays. We show that the enhanced optical absorption in qNL arrays is due to combination of three mechanisms: 1) each qNL serves as an effective anti-reflection coating, 2) the presence of qNLs increases the optical interactions between the adjacent dielectrics to conclude elevated levels of light trapping, and 3) the presence of qNL induces strong light concentration of the incoming radiation into the dielectric structures.

UiO-66 metal organic framework as stable platform for non-linear optical applications

We report on the experimental study the non-linear optical properties of UiO-66 metal-organic framework with high thermal and chemical stability. We demonstrate the coherent conversion of high-intensity incoming radiation into the third harmonics ranging from 450 to 600 nm. Moreover, eclipse z - scan of single UiO-66 microcrystals made it possible to determine the saturable absorption coefficient (βeff = −1.415·10-2 cm/GW at 515 nm and −3.865·10-1 cm/GW at 1030 nm), thereby, bringing UiO-66 to the list of nonlinear and stable MOFs for real-life photonic applications.

A STABILITY ESTIMATE IN THE SOURCE PROBLEM FOR THE RADIATIVE TRANSFER EQUATION

It is given a stability estimate of a solution of a source problem for the stationary radiative transfer equation. It is suppose that the source is an isotropic distribution. Earlier stability estimates for this problem were known in a partial case of the emission tomography problem only, when the scattering operator vanishes, and for the complete transfer equation under additional and difficult in checking conditions for the absorption coefficient and the scattering kernel. In the present work, we suggest a new and enough simple approach for obtaining a stability estimate for the problem under the consideration. The transfer equation is considered in a circle of the two-dimension space. In the forward problem, it is assumed that incoming radiation is absent. In the inverse problem for recovering the unknown source some data for solutions of the forward problem related to outgoing radiation are given. The obtained result can be used for an estimation of the summary density of distributed sources of the radiation.

Water condensation zones around main sequence stars

Understanding the set of conditions that allow rocky planets to have liquid water on their surface, in the form of lakes, seas, or oceans, is a major scientific step in determining the fraction of planets potentially suitable for the emergence and development of life as we know it on Earth. This effort is also necessary to define and refine what is known as the habitable zone (HZ) in order to guide the search for exoplanets likely to harbor remotely detectable life forms. To date, most numerical climate studies on this topic have focused on the conditions necessary to maintain oceans, but not to form them in the first place. Here we use the three-dimensional Generic Planetary Climate Model, historically known as the LMD generic global climate model, to simulate water-dominated planetary atmospheres around different types of main sequence stars. The simulations are designed to reproduce the conditions of early ocean formation on rocky planets due to the condensation of the primordial water reservoir at the end of the magma ocean phase. We show that the incoming stellar radiation (ISR) required to form oceans by condensation is always drastically lower than that required to vaporize oceans. We introduce a water condensation limit, which lies at significantly lower ISR than the inner edge of the HZ calculated with three-dimensional numerical climate simulations. This difference is due to a behavior change of water clouds, from low-altitude dayside convective clouds to high-altitude nightside stratospheric clouds. Finally, we calculated the transit spectra, emission spectra, and thermal phase curves of TRAPPIST-1b, c, and d with H2O-rich atmospheres, and compared them to CO2 atmospheres and bare rock simulations. We show using these observables that JWST has the capability to probe steam atmospheres on low-mass planets, and could possibly test the existence of nightside water clouds.

Evaluation of a wind tunnel designed to investigate the response of evaporation to changes in the incoming long-wave radiation at a water surface

Abstract. To investigate the sensitivity of evaporation to changing long-wave radiation we developed a new experimental facility that locates a shallow water bath at the base of an insulated wind tunnel with evaporation measured using an accurate digital balance. The new facility has the unique ability to impose variations in the incoming long-wave radiation at the water surface whilst holding the air temperature, humidity and wind speed in the wind tunnel at fixed values. The underlying scientific aim is to isolate the effect of a change in the incoming long-wave radiation on both evaporation and surface temperature. In this paper, we describe the configuration and operation of the system and outline the experimental design and approach. We then evaluate the radiative and thermodynamic properties of the new system and show that the shallow water bath naturally adopts a steady-state temperature that closely approximates the thermodynamic wet-bulb temperature. We demonstrate that the long-wave radiation and evaporation are measured with sufficient precision to support the scientific aims.

Effect of WO3 on the attenuation parameters of TeO2–La2O3-WO3 glasses for radiation shielding application

The attenuation capability of tellurite glasses with composition of (100-x)TeO2–5La2O3-xWO3 where x = 10, 15, 20, and 25% was analyzed. Radiation attenuation parameters such as mass, linear attenuation coefficients (MAC, LAC) and effective atomic number were determined at various energies. The S4 glass sample, which contains the highest WO3 content and smallest TeO2 concentration, has the greatest MAC at all energies. The glasses with the highest densities also have the highest LAC values, with greater WO3 content leading to greater density in the glass system. The half value layer (HVL) values of the samples are positively proportional with the energy of the incoming radiation, greatest at the highest tested energy. The ratio between the tenth value layer (TVL) values for S1 and S4 are greater than one at all energies, which means that S1's TVL, the glass with the smallest WO3 content, is higher than S4's TVL. The mean free path values were shown to have an inverse trend with the WO3 content in the samples. The S4 sample, the glass with the highest WO3 content and lowest TeO2 content, has the greatest Zeff at all energies.

Ocean-atmosphere heat exchange seasonal cycle on the West Florida Shelf derived from long term moored data

Twenty-three years of surface meteorological and oceanographic data sampled from moored buoys are used to study the seasonal and interannual variations of ocean–atmosphere heat exchange and its influence on West Florida Continental Shelf (WFS) water temperature and stratification. The data are from the University of South Florida's Coastal Ocean Monitoring and Prediction System (COMPS), part of the Southeast Coastal Ocean Observing Regional Association (SECOORA). Observed are incoming short and longwave radiation, air and sea surface temperatures (AT and SST), barometric pressure, relative humidity, wind velocity, water column velocity profiles, and water column temperature at discrete depths. These data are used to estimate net shortwave and longwave radiation and sensible and latent heat fluxes via the COARE 3.6 algorithm. When combined, these radiative and turbulent heat flux influences are compared with the heating and cooling of the WFS water column and SST. On seasonal average, heating starts in February and lasts through August, with a maximum rate of change in May, while cooling starts in September and lasts through January, with the maximum rate of change in October. Also on seasonal average, SST varies from 18.4 °C in February to 30.4 °C in August at mooring C10 (at the 25 m isobath) and from 20.1 °C in February to 30.2 °C in August at mooring C12 (at the 50 m isobath), the differences in the seasonal range being due to increased ocean circulation influence in deeper water. Both the spring and fall transition onsets, February and August, respectively, occur when the sign of the net heat flux changes. The water column begins to stratify in March, peaking in June–July and lagging the surface heating by one or two months, then decreasing through September at C10 and October at C12. Stratification is also modified by persistent upwelling when the Gulf of Mexico Loop Current (LC) interacts with the WFS slope at its southwest corner near the Dry Tortugas. Interannual temperature anomalies from the seasonal cycle are also related to how the LC interacts with the WFS slope.

Fabrication of Co3O4/Co3S4/CNTs for photocatalytic treatment of wastewater under xenon lamp.

The current study is about the synthesis of nanoparticles (NPs) of cobalt oxide (CO) and cobalt sulfide (CS) followed by their nanocomposites as CO/CS and CO/CS/CNT by ultrasonication approach. The addition of carbon-based materials in the oxides and sulfides enhances their performance by developing physico-chemical interactions. Prepared NPs were utilized for the photodegradation of organic contaminants. The characteristics, as well as the efficiency of the prepared samples, have been systematically examined by X-ray diffraction (XRD) technique, Fourier transform infrared spectroscopy (FTIR), and UV-vis spectroscopy. Photocatalytic activities of bare samples and synthesized nanocomposites were tested for the degradation of methyl orange (MO) using a xenon lamp. The percentage degradation of dye was 24.14%, 57.94%, 71.66%, and 85.04% in the presence of CO, CS, CO/CS, and CO/CS/CNT, respectively. Crystal violet (CV), Rhodamine B (rho-B), and industrial wastewater were also degraded by the ternary composite. The comparative studies showed the best performance of CO/CS/CNT, which enhanced the generation of electron-hole pairs by absorption of photons of incoming radiations, increased charge separation, and maximum surface area for adsorption.

The Effect of Shading Devices on OTTV (Overall Thermal Transfer Value) Value of Office Buildings: Case Study of PT Industri Kapal Indonesia (IKI) Building

One of the passive design strategies that effectively reduce the heat load on the building envelope, especially in areas with a large surface area of glass shading Device. The research aims to measure the design influence of shading devices against the value of Overall Thermal Transfer Value (OTTV) buildings. Research using quantitative methods, research done by trying Shading devices with Vertical Models, Horizontal multiple fins, and Egg crates, which have the length and slope provided by the Indonesian National Standard SNI. It tests each design shading measured on an impairment basis OTTV the best and best under 45 Watt/m². The results of the study show that shading devices affect the impairment of OTTV. The longer the shading device and the higher the slope, the more effective it is in blocking incoming radiation through the glass surface. Impairment OTTV existing buildings without a shading device have an initial value of 69.572 W/m2, decreased by 55% to 31.57 W/m2. Shading an egg crate with length120 cm with a slope of 40° is the best shading based on a comparative analysis between vertical louver shading and horizontal multiple fin shading. This is due to shading egg crates being able to respond to the sun in incoming low and high altitude angles to minimize or block radiation that enters through the glass surface.

Comparative analysis to study the Darcy–Forchheimer Tangent hyperbolic flow towards cylindrical surface using artificial neural network: An application to Parabolic Trough Solar Collector

Solar thermal collectors convert sunlight into useful thermal energy by absorbing its incoming radiation. Concentrated solar power technologies use the parabolic trough solar collector to collect solar energy with temperatures ranging from 325–700 K. The tangent hyperbolic fluid model is one of the most important non-Newtonian fluid models. Laboratory studies demonstrate that this model accurately predicts the shear thinning phenomenon. In addition, tangent hyperbolic fluid has a better heat transfer performance due to its rheological bearing at various shear rates. The current study investigates the heat transmission performance of Darcy–Forchheimer tangent hyperbolic radiative inclined cylindrical film movement in parabolic trough solar collector with an irregular heat sink/source utilizing the Levenberg–Marquardt technique and backpropagated neural networks. Through the implementation of required transformations, this system is turned into an equivalent nonlinear ordinary differential system. The findings are investigated for Newtonian and tangent hyperbolic fluid cases to understand the rheological characteristics. The outcomes are considered using graphical and mathematical evaluations. Fluids featuring tangent hyperbolic rheological conductivity are obligatory for active rate of heat diffusion. As a consequence, these fluids may be employed in Parabolic Trough Solar Collector for increased heat transmission rate and operational usage of solar energy. Furthermore, We create a dataset using the Runge–Kutta fourth-order shooting technique to create the proposed multilayer perceptron artificial neural network. The data points representing the MoD values are observed to be closely clustered around the zero deviation line. Additionally, it is important to highlight that these data points have relatively small numerical values. Moreover, when calculating the average MoD values for each output, it becomes evident that they are consistently very low.

Integrated optical and thermal model to investigate the performance of a solar parabolic dish collector coupled with a cavity receiver

The cavity receiver is the most promising type of receiver, which drops the heat loss and converts the incoming concentrated radiation to useful energy. In this work, the coupled optical-thermal investigation is performed for a novel cavity receiver of a 40 m2 parabolic dish collector to estimate the thermal performance. The variation of thermal performance with inclination γ, wind direction ψ, wind speed V, and inlet temperature THTF,i has been discussed. SolTrace and ANSYS® Fluent are used for optical and thermal modeling, respectively. Surface errors, heat flux at each coordinate of the receiver, and the parabolic dish effect have been considered in the study. The text user interface (TUI) over graphical has been adopted in ANSYS® to reduce the computational expenditure for variation of parameters. In thermal modeling, a user-defined function (UDF) is applied for mapping data from SolTrace simulation with 107 rays. Therminol 66, as heat transfer fluid, is used in the receiver coils. The optical performance of 84.15% is achieved at an aiming height of 4.5 m. The thermal performance of 73.11% is obtained as maximum in no-wind conditions for 90° tilt. The worst thermal performance is obtained in side-on wind. Further, the performance has been compared with other models and found to be performing well.

Evaluation of summer mean radiant temperature simulation in ENVI-met in a hot Mediterranean climate

ENVI-met is currently one of the most popular simulation tools of urban microclimates, used by researchers and designers alike. Yet, in recent years some concerns have been raised regarding the software's capability to accurately simulate the effects of solar irradiance on increased heat stress, especially in hot weather conditions. These concerns have eventually led to the implementation of a new radiation scheme in version 5 of the software. This study set out to evaluate whether this new scheme increased the software's accuracy in evaluating incoming shortwave and longwave radiation fluxes, expressed as Mean Radiant Temperature (MRT), by comparing monitored and simulated summertime values at 60 locations.Our results show that while ENVI-met's new version improved MRT simulation accuracy, the software systematically underestimated the magnitude of MRT in both shaded and unshaded summer conditions. Our MRT evaluation resulted in an RMSE of 6.08 °C in the shade and 13.32 °C at locations fully exposed to solar radiation, which may result in inaccurate and less severe appreciation of outdoor heat stress, especially when outdoor shade is missing. Based on our analysis, we suggest that the origin of error may stem from inaccurate representation of longwave radiation fluxes emitted by ground surfaces.

Physical, structural, mechanical, and various radiation shielding properties of TeO2-GeO2-ZnO-Al2O3-Li2O-M (M= WO3, MoO3, PbO, and CuO) glasses

In this work, four glasses of germanate tellurite zinc aluminum with 5 mol. of different heavy metal oxide were syntheses. Using melt-quenching-annealing technique 50TeO2-20GeO2-10ZnO–5Al2O3–10Li2O-5M (mol%) were M = PbO, MoO3, WO3, and CuO. For the fabricated glasses mechanical properties such us: poisson ratio and microhardness were calculated theoretically. The structural behaviour of these glasses was studied using X-ray diffraction (XRD), Raman spectroscopy were employed to invistagte the vibrational modes such us symmetric stretching vibration mode of the [TeO4] and symmetric stretching vibration of the [GeO4] tetrahedra. Attenuated total reflectance-Fourier transform infrared (ATR-FTIR) were used to invistgate and confirm the Raman spectroscopy results. The radiation attenuation factors for the prepared glasses were reported in the energy range of 0.015–15 MeV. The results demonstrated that the glass with PbO has the highest mass attenuation coefficient (MAC), The MAC for the glass with PbO is varied between 253.012 cm2/g (at 0.015 MeV) and 0.185 cm2/g (at 15 MeV), while it is varied between 221.85 and 0.171 cm2/g. We reported the effective atomic number (Zeff) for the prepared glasses and we discussed the role of PbO, MoO3, WO3 and CuO on the Zeff values for these glasses. The half value layer (HVL) was reported and we found that the glass with PbO has the smallest HVL. The HVL results revealed that the glass with PbO can attenuate attenuate more photons than the glasses with MoO3, WO3 and CuO. The thickness of the glass must be less than 1 cm to shield 50% of the photons with energy less than 0.3 MeV. For energy of 0.5 MeV, we need a layer of about 1.5 cm to shield 50% of the incoming radiation.