Incident Radiation Research Articles

Nonlinear optical response and bistability of intersubband polariton in a planar microcavity: Role of dynamic Coulomb coupling

We theoretically investigate the steady-state bistable intersubband polariton response of quantum-well (QW) structures embedded into planar semiconductor microcavity to intense plane wave incident radiation. A rigorous semiclassical approach employs the transfer matrix formalism and the sheet model, which includes the dynamic depolarization effect. Results of comprehensive numerical simulations on reflectance characteristics of the structures with strong coupling between the ground cavity mode of the electromagnetic field and intersubband excitations in QWs are presented. The mechanism of the polariton-based optical bistability (OB) is revealed. Both the mirror-based optical bistability (MOB) and the intrinsic optical bistability (IOB) are investigated, with the focus on the MOB. Polariton-based bistabilities driven by cyclically changing intensity of the incident radiation, frequency of the incident radiation, and the angle of incidence are considered. It is found that the presence of the dynamic depolarization effect brings novel features to the OB reflectance characteristics of the structures. Effect of accumulation of the MOB cooperativity parameter is revealed. The concept of effective QW is proposed to describe a tremendously enhanced MOB response of multiple identical QWs particularly located in the cavity. A remarkable possibility of MOB in systems of multiple particularly located QWs with big values of dephasing rate is demonstrated. It is shown that the transition from bistability to multiple bistability and to multistability for two QWs can be controlled by slight manipulation of the angle of incidence. A possibility is found for an outstanding width of the hysteresis of the angular-domain OB, being about one degree.

Additional far-red increases fruit yield of greenhouse sweet pepper mainly through enhancing plant source strength

Supplementary lighting is necessary for year-round greenhouse production of fruit vegetables in high-latitude regions. Far-red (FR) radiation can influence plant photomorphogenesis as well as photosynthesis. We aimed to identify the effects of supplementary FR on fruit set and yield of sweet pepper, and its underlying mechanisms via a yield component analysis. A 24-week greenhouse experiment was conducted with cultivars 'Gialte' and 'Margrethe', where FR was added to 190 μmol·m−2·s−1 of white supplementary light in four treatments: 0, 50 or 100 μmol·m−2·s−1 FR throughout the whole generative growth phase (since 8 weeks after transplanting), or 100 μmol·m−2·s−1 FR for only four weeks (12 to 16 weeks after transplanting). Fruit yield increased linearly with the cumulative amount of FR provided in supplementary light. The increased fruit dry weight with additional FR was mainly associated with an increased plant dry weight, accompanied by a marginal increase in the fraction of dry matter partitioned to fruits. The increase in plant dry weight resulted from an increased light use efficiency (plant dry weight per unit of supplementary photosynthetic active radiation (PAR) incident on top of the canopy) and an increased incident PAR (due to taller plants closer to the lamps). However, additional FR reduced radiation use efficiency (plant dry weight per unit of supplementary PAR plus FR incident on top of the canopy), indicating that additional FR was used less efficiently than PAR for biomass production. Additional FR enhanced fruit set percentage and fruit set fluctuations over time, where both long-term and short-term FR application elevated the subsequent fruit set peak after the start of FR application. Without additional FR, 17% fruits in 'Gialte' and 25% in 'Margrethe' showed medium or severe cracking. Additional FR substantially reduced this percentage to 8% in both cultivars. We conclude that additional FR improves sweet pepper fruit set and yield in greenhouses, mainly by enhancing plant source strength.

Numerical simulation of an efficient circular solar air heater integrated with a CPC

A numerical analysis of a solar air heater is conducted to evaluate the thermal performance of the proposed solar collector under various situations for providing high-temperature airflows. The research investigates the design of a circular solar air heater including revolving airflow combined with a compound parabolic concentrator to enhance incident radiation. The two principal components of the circular heater and the applied concentrator possess compatible geometries and are well integrated. The numerical CFD study is conducted by solving the Navier-Stokes and energy equations for the primary forced convection airflow in the circular solar air heater and the free convection airflow within the cavity of the compound parabolic concentrator. Multiple test cases with varying solar irradiation and air mass flow rates are analyzed, incorporating surface-to-surface radiation. The CFD study of the circular solar air heater is compared with the experimental results. In the analyzed test cases with an air mass flow rate of 0.01 kg/s and a solar heat flux of 1000 W/m2, the thermal efficiency is calculated to be 70 %, despite the elevated outlet air temperature reaching 120 °C. This indicates a 100 % increase in efficiency compared to conventional smooth duct solar air heaters. The research concludes that the circular solar air heater with revolving airflow, combined with a compound parabolic concentrator, results in a highly efficient heat exchanger for generating high-temperature airflow suitable for many applications.

PM2.5 reduces the daytime/nighttime urban heat island intensity over mainland China

PM2.5 pollution severely threatens people's living environment and health, significantly affect urban heat island (UHI). In this study, in-situ observed data were combined with satellite data via refined pollution intensity classification methods, and the relationships between PM2.5 and canopy/surface UHI (CUHI/SUHI) were analyzed. PM2.5 reduced the UHI in nearly all the environments, with more pronounced effects during clear-sky daytime and winter (-0.33 °C for the SUHI) and less pronounced effects at all-sky nights and in summer. For the former, PM2.5 primarily diminishes the UHI intensity (UHII) by weakening incident radiation; this radiative forcing effect is exacerbated by the combination of PM2.5 and high humidity, which is further amplified by winter pollution peaks. At night, the UHII primarily influenced by the initial temperature conditions during the day. Less intake of surface energy on high-pollution days, which in turn affects longwave radiation from the surface/canopy at night. Additionally, PM2.5 has been found to significantly influence UHI through its interaction with potential influential factors and its filtering effect (different PM2.5 levels correspond to varying conditions of these factors). This study with new insights into the impact of PM2.5 on UHI could aid in the design of strategies to improve urban heat and pollution environments.

Amended Calculation of Solar Heat Gain Coefficient Based on the Escape of Incident Solar Radiation

The solar heat gain is an important component of building cooling load, and its magnitude affects building energy consumption directly. In buildings with glass curtain walls, the window to wall rate is close to 1, so the amount of solar heat gain is huge, which directly determines the energy consumption level of a building’s air conditioning system. In fact, incident solar radiation can escape to the exterior through the transparent envelope, which cannot be ignored in buildings with glass curtain walls. This will cause changes in solar heat gain, so the solar heat gain coefficient (SHGC) needs to be corrected. In this paper, the heat transfer process of solar radiation in window shading systems is analyzed, and an amended calculation model for the SHGC is established. Multiple forms of windows and shading systems are selected and their SHGC-amended factor for rooms with different orientations under different standard calculation conditions in various countries is calculated. As the number of glass layers increases, the transmittance of the window gradually decreases, the reflectance and absorbance gradually increase, and the SHGC value decreases. The SHGC-amended factor decreases with an increasing escape rate, and the two can be approximated as a linear correlation. The weakening effect of shading on the solar heat gain of the buildings is overestimated. The SHGC-amended factor proposed in this paper can calculate building solar heat gain more accurately.

Two-dimensional P1 approximation (P1-2D) for the Description of the Radiant Field on Cylindrical Solar Photocatalytic Reactors

The local volumetric rate of photon absorption (LVRPA) was formulated by solving the radiative transfer equation (RTE) in polar coordinates with the P1 approximation approach (P1-2D) for the description of the radiant field in cylindrical solar photocatalytic reactors. A general expression of the LVRPA was formulated that can be employed on cylindrical photocatalytic reactors with an incident radiation constant along the reactor length. CPC and tubular photocatalytic reactors were used as reactor models and Lambert's cosine law (irradiance) was considered when using the boundary conditions. Simulations were carried out using the commercial TiO2-P25, its optical properties taken from the literature. The LVRPA was found to decrease exponentially from the reactor wall to its center. literature rate of photon absorption per unit of reactor length (VRPA/H) increased exponentially with the catalyst loading until a value where no significant increase was observed and was found to increase with reactor radius, information that agrees with the literature. The optimum catalyst loading with the CPC reactor was about 0.364 g/L with a reactor radius equal to 1.65 cm similar to that found in the literature when using the six-flux model in two dimensions (SFM-2D). The apparent optical thickness τ_App1 newly formulated with the P1 approximation was introduced for optimization purposes and was found more reliable than the optical thickness τ. This parameter not only removes the dependence of the optimum catalyst loading on the reactor's radius but also its dependence on catalyst albedo. τ_App1 was found about 9.73 and 14.6 for CPC and tubular reactors respectively and provides the optimum catalyst loading and the reactor radius that optimize the radiation absorption inside both reactors.

An Improved Transformer Model for Sap Flow Prediction that Efficiently Utilizes Environmental Information

AbstractAs an important reference for assessing plant water consumption and estimating plant transpiration, it is of great significance to achieve accurate prediction of plant sap flow. A number of deep learning models were established and compared using approximately 3 years of continuous eucalyptus flow time series data collected from the SAPFLUXNET open dataset and 6 environmental factors, including shortwave solar incident radiation, air temperature, air relative humidity, net radiation, vapor pressure deficit, and photosynthetic photon flux density. The experimental results show that the improved Transformer model, with the introduction of a two-step self-attention mechanism and simplified design, maintains significant predictive performance advantages compared to the original Transformer model, long short-term memory, gated recurrent unit, and temporal convolutional neural network models. In the shorter 1-h forecast, the mean squared error and coefficient of determination (R2) of the improved Transformer model are 0.0191 and 0.965, respectively. Compared to the suboptimal typical Transformer model, the MSE is reduced by 22.9%, and R2 is increased by 1.0%. Additionally, the improved model maintains stable predictive performance advantages in long-term plant flow prediction. In the longest 8-h advance prediction, the MSE is reduced by 14.9% compared to the suboptimal Transformer model, and R2 increases by 3.0% compared to the Transformer model. The comprehensive experimental results show that the improved Transformer model makes more effective use of environmental information to achieve more accurate and long-term plant flow prediction. This study emphasizes the basic principle and validity of the two-step self-attention network structure and provides a valuable basis for developing more effective methods for predicting plant sap flow.

Influence of a City Block on ES-CFD Coupled Analysis

Coupled analysis using the complementary methods of energy simulation (ES) and computational fluid dynamics (CFD) can improve the calculation accuracy of thermal environment simulations. However, existing studies on ES-CFD coupled analyses that consider the effects of solar radiation and surrounding conditions have been insufficient. In practice, net solar radiation fluctuates, owing to the influence of urban blocks, and the solar radiation incident on the interior determines the heating range of the interior, which results in fluctuations in the convective heat transfer coefficient. This study conducted an ES-CFD coupled analysis to examine differences in the convective heat transfer coefficients due to the different insolation conditions and the surroundings of target buildings. The risk of condensation was evaluated using the dew point temperature in the analysis model, and a neutral insulation performance was employed in the set cases with the presence or absence of urban streets as a variable. Buildings within urban city blocks were observed to have a lower dew point temperature and a higher risk of condensation, which is a reasonable assessment. The results of this study will contribute significantly to the development of comprehensive simulation technologies.

Boric acid-free electrodeposition process and solar–thermal energy conversion of and Ni-carbon black nanocomposite coatings

AbstractThis work focuses on the development of a multi-layered system, of bright nickel electrodeposited on a steel substrate, and a second layer composed of black nickel either with or without carbon black nanoparticles (CB NPs), aiming for an efficient conversion of incident solar radiation into heat, for the fabrication of solar collectors. The structural characterization, revealed that the bright nickel film was composed of metallic nickel, while the black coatings contained amorphous nickel compounds. SEM analysis unveiled the presence of pinholes on the surface of the bright nickel film, suggesting that the black nickel coating was ineffective in sealing them. The appearance of cracks with the increase in the deposition time was observed. With the nanocomposite of black nickel and CB NPs, these cracks can be avoided and the pinholes sealed. The CB NPs were found to reduce reflectance, enhancing the conversion of solar energy into heat. Graphical abstract

Formation of optical resonances at the initial stage of radiation destruction of disperse medium made of a transparent dielectric by means of a powerful laser

By means of numerical simulation, we study optical resonances that arise when radiation from an ytterbium fiber laser (λ = 1065 ± 3.25 nm), a blue diode laser (λ = 450±8 nm) or a CO2 laser (10.6 μm) is scattered on a single particle of a transparent dielectric (an oxide, a fluoride, ZnSe), as well as in an ensemble of randomly packed particles of various sizes. If the particle diameter is comparable to the radiation wavelength (but is no less than 3λ/4) then, at a certain ratio between the particle diameter, the refractive index of its material and the radiation wavelength, the particle becomes a microresonator. The maximum intensity of scattered radiation inside or outside such particle depends on the combination of the above-said parameters and can exceed the intensity of the incident radiation dozens of times. In case of a powder, the interference pattern is formed by all particles at once and, occurrence of an optical resonance is more likely. Even with a slight change in the radiation wavelength of an ytterbium laser or a blue diode laser (within the lasing line width), some particles in the powder become microresonators, while others cease to be microcavities. Therefore, concentration of scattered radiation of the ytterbium laser in individual particles plays a key role at the initial stage of optical destruction of the powder. As the experiment shows, this allows to overcome the threshold of optical destruction of porous targets made of various transparent substances (CaF2, SiO2, BaF2, YbF3, Fe:MgAl2O4, Al2O3, 1mol.%Nd:Y2O3, YSZ, TiO2, ZnSe) by means of a radiation pulse from an ytterbium laser having low intensity (0.46 MW/cm2). With the refractive index of the material increasing from 1.429 (CaF2) to 2.479 (TiO2), the average delay in the formation of a laser plume decreases from 46 ms to 25 μs, i.e. by three orders of magnitude. This correlates with the fact that in the calculations, the maximum intensity of this laser's radiation scattered in the powder increases with n increasing. In compliance with this are the results of obtaining nanopowders from transparent oxides and ZnSe by means of pulse-periodic radiation of an ytterbium laser. Output of the nanopowder Yb0.05:Y1.95O3:(ZrO2)0.05 with n = 1.901 (for Y2O3) is 15 g/h, and the maximum output (100 g/h) is realized in case of ZnSe (n = 2.482). At the same time, it is not possible to obtain nanopowder from CaF2 (n = 1.429), because the moving target does not evaporate.

Production of calcium and magnesium titanates using concentrated solar energy

Solar energy is an adequate technology for different processes in metallurgy, materials processing, recycling, or ceramic-refractory materials, because of the high temperatures attained which are reached when the solar radiation is concentrated. This growing interest has also emerged from the obtaining of such temperatures without releasing pollutants such as carbon dioxide, SOx, NOx, or dioxins. Other benefits associated with concentrated solar energy are that this energy source is virtually free and the possibility of operating in places isolated from the electrical grid. Therefore, this research proposes the integration of concentrated solar energy in the production of calcium and magnesium titanates, which are materials with increasing demand in the field of electric components. Experimental work was carried out in the Odeillo solar furnace located in Font-Romeu-Odeillo-Via (France) using a 1.5-meter parabolic concentrator and mixtures of CaO and TiO2 and MgO and TiO2 in 1:1 molar ratio. Mixtures were subjected to values of incident radiation exceeding 900 W/m2 without using any special atmosphere and in very short times, which did not surpass 10 min. X-ray diffraction technique was employed to confirm the formation of the CaTiO3 and MgTiO3 perovskites. Therefore, concentrated solar energy might be a novel, fast, and environmentally sustainable manner of producing calcium and magnesium titanates.

Sustainable Manufacturing of 3D-Printed Cyclic Olefin Copolymer Coversheets with Gahnite for Enhanced Silicon Photovoltaic Efficiency

Solar energy plays a vital role in the renewable and pollution-free energy generation. A significant amount of solar energy can be generated through the utilization of solar photovoltaics and collectors. The application of antireflective coatings is an essential factor that effectively absorbs the incident solar radiation and enhances the power conversion efficiency (PCE) of the photovoltaic cells. This study presents the sustainable manufacturing of cyclic olefin copolymer (COC) coversheet on the polycrystalline silicon photovoltaic cells through 3D printing technique to reduce the reflection losses. In addition, gahnite (ZnAl2O4) was added with COC at varying weight percentages to enhance the antireflection characteristics. The PV cells covered by COC with gahnite (COCG) coversheets are analyzed for structural, thermal, mechanical, electrical and optical behaviour. As seen, the COC with 3 wt% of gahnite (CS3) exhibits optimal power conversion efficiency (PCE) in both open (18.06%) and controlled (18.87%) environment. The optical analysis clearly shows that the sample CS3 achieves lowest reflectance of 4.23% and highest transmittance of 95.47%, which significantly increases the absorbance. The results from current investigation demonstrated that COCG could be an ideal antireflection coversheet that effectively improves the PCE of polycrystalline PV cells.

Multilayer architected polymer nanostructure for microwave absorber-based EMI shielding

Reflection-based electromagnetic interference shielding materials, though effectively stop the radiation, redirect the interference to nearby electronic devices, creating secondary pollution. In this sense, it is better to use absorption-dominant lightweight and flexible materials with high shielding effectiveness. This paper reports the fabrication of a multilayered polymer nanocomposite for enhancing electromagnetic interference shielding applications through absorption. By using a doctor-blade technique, three individual layers of poly(vinylidene fluoride) based polymer nanocomposite, each with different fillers, were prepared and stacked together to form a 3 mm thick multilayered (four-layer) composite. The fillers were 5% Ag-decorated graphene nanoplatelets, acid-functionalized MWCNT, and barium hexaferrite. Between 8 and 18 GHz, this multilayered composite absorbs a maximum of 90% of incident microwave radiation, resulting in a shielding in the range of 20–45 dB. This structure is very useful for developing flat and lightweight absorbers. For comparison, a homogeneously prepared nanocomposite comprising all these three fillers is found to give a shielding of around 53 dB with a reflection ranging between 78% and 89%.

Rapid deep learning prediction model using satellite imagery for radiation accident Announcement system in Serbia

Radioactivity environmental monitoring with the help of the Radiation Accident Announcement System (RAAS) established in the Republic of Serbia is of vital importance for rapid response in the event of intervention dose values being reached such as Operational Intervention levels (OILs). There are cases of impossibility of using a ground-based model in order to predict the transport and spread of radiation during a nuclear accident such as the one in the Fukushima Daiichi nuclear power plant 2011. Modern technology has made it possible to use machine learning models with remote sensing data in addition (or an alternative) to atmospheric models with ground data collection methods. Deep learning (DL) model was developed and trained on a satellite-based cloud fraction dataset to forecast diurnal cloud drift. By forecasting the movement of clouds that are potential carriers of radioactive materials, decision-makers can provide an adequate response with an Action Plan in the case of nuclear and radiation accidents and incidents. Designed Application Programming Interface (API) has been developed and integrated between the DL model and the RAAS. In this way, the monitoring, data sharing and exchange processes were automated in order to trigger the DL model when an OILs value of 1 μSv/h is reached. The hyperparameter optimization process of the DL model was done with grid search and Particle Swarm Optimization (PSO) to achieve maximum performance on the data in a reasonable amount of time. The evolution metrics to monitor and measure the performance of the DL model were cosine similarity (CS) and structural similarity (SS) with the best score of 0.78282 and 0.27063 for grid search, respectively, while 0.27065 and 0.78282 for PSO, respectively. It can be concluded that remote sensing imagery with DL model is an alternative approach against a ground-based forecasting system, and is able to predict in near real-time independently of ground network system and data.

A public grid of radiative transfer simulations for Lyα and metal lines in idealised galactic outflows

The vast majority of star-forming galaxies are surrounded by large reservoirs of gas ejected from the interstellar medium. Ultraviolet absorption and emission lines represent powerful diagnostics to constrain the cool phase of these outflows, through resonant transitions of hydrogen and metal ions. The interpretation of these observations is often remarkably difficult as it requires detailed modelling of the propagation of the continuum and emission lines in the gas. To this aim, we present a large public grid of ≈20 000 simulated spectra that includes H I Lyα and five metal transitions associated with Mg II, C II, Si II, and Fe II which is accessible online. The spectra have been computed with the RASCAS Monte Carlo radiative transfer code for 5760 idealised spherically symmetric configurations surrounding a central point source emission, and characterised by their column density, Doppler parameter, dust opacity, wind velocity, as well as various density and velocity gradients. Designed to predict and interpret Lyα and metal line profiles, our grid exhibits a wide diversity of resonant absorption and emission features, as well as fluorescent lines. We illustrate how it can help better constrain the wind properties by performing a joint modelling of observed Lyα, C II, and Si II spectra. Using CLOUDY simulations and virial scaling relations, we also show that Lyα is expected to be a faithful tracer of the gas at T ≈ 104 − 105 K, even if the medium is highly ionised. While C II is found to probe the same range of temperatures as Lyα, other metal lines merely trace cooler phases (T ≈ 104 K). As their gas opacity strongly depends on gas temperature, incident radiation field, metallicity and dust depletion, we caution that optically thin metal lines do not necessarily originate from low H I column densities and may not accurately probe Lyman continuum leakage.

Impact of Battery Levels of a Cordless LED Curing Unit on Resin Cement under Varied Lithium Disilicate Thicknesses and Translucencies.

This study aimed to evaluate the impact of battery levels on the emission of a multi-peak cordless LED light-curing unit (LCU) and the effect on the degree of conversion (DC) and Knoop hardness (KH) of a light-cure resin luting agent activated through varying lithium disilicate (LiS2) ceramic thicknesses and translucencies. High and low translucency LiS2 discs (IPS e.max Press HT and LT, respectively; shade A1) with thickness of 0.5, 1.0, 1.5, and 2.0 mm were fabricated. Resin luting agent specimens (Variolink Esthetic LC) were prepared and cured using a Bluephase G2 LCU at different battery levels (100%, 50%, and 10%) through the LiS2 ceramics. The transmitted irradiance was evaluated using USB4000 MARC, while FTIR and a microhardness tester assessed DC and KH, respectively. After ensuring homoscedasticity, the data wee analyzed using analysis of variance and Tukey HSD test (α=0.05). The study found strong positive correlations between battery levels and irradiance, particularly with no ceramic interposition and through HT ceramics (R2=0.9471), although this correlation diminished with thicker HT (R2=0.7907) and LT ceramics (R2<0.2980). Both battery levels and ceramic thickness significantly influenced transmitted irradiance (p<0.0001), resulting in lower values with decreased battery levels and increased ceramic thicknesses (p<0.0001). LT ceramics showed lower transmittance than HT. DC was significantly affected by both battery levels and ceramic thicknesses, with generally lower DC values except for LT ceramics at a 10% battery level (p<0.0001). No significant differences in DC were observed between HT and LT translucencies (p=0.548). KH was higher in HT than LT ceramics at 100% and 50% battery levels, with thicker ceramics showing lower KH values at 10% battery level (p<0.0001). Conclusion: Reduced battery levels in cordless LED curing units significantly affect the irradiance, degree of conversion, and hardness of light-curable resin luting agents. Maintaining battery levels above 50% is recommended for optimal performance. Thicker and more opaque ceramics significantly impacted incident irradiance. However, preserving radiant energy could potentially mitigate these limitations.

A Calculation Study on the Escape of Incident Solar Radiation in Buildings with Glazing Facades

More and more modern buildings are using glass curtain walls as their building envelope. The large area of window leads to a significant increase in solar heat gain, resulting in an increase in the cooling load and energy consumption of the building envelope. In the calculation of building cooling load, the thermal performance parameter of windows, the solar heat gain coefficient, is used to calculate the solar radiation heat gain of the windows. The window-to-wall ratio of buildings with glazing facades is large, and the phenomenon of escape of incident solar radiation cannot be ignored. In order to calculate the solar radiation escape rate, a dynamic model of solar radiation escape rate incorporating the solar path tracking model is developed in this research, which can achieve big data simulation analysis based on actual meteorological conditions. The model is programmed and simulated using MATLAB R2024a software. Five representative cities from different climate regions in China are selected and the variation rule of solar radiation escape rate are analyzed on three different time scales: day, month, and year. The influence of building orientation was also calculated and analyzed. The numerical calculation results indicate that the escape solar radiation rate varies with the incident angle of solar radiation at different times. It was found that the smaller the solar azimuth angle and solar altitude angle, the smaller the escape rate of solar radiation. The latitude of a city has a significant impact on the solar radiation escape rate. The weighted average of the solar radiation escape rates for each city were calculated for both summer and winter. Regardless of the season, the city’s location, and the orientation of the room, the value of solar radiation escape rate varies from 8.64% to 10.33%, which indicates that the solar radiation escape phenomenon cannot be ignored in glass curtain wall buildings. The results can be used as a reference value of solar radiation escape rate for the correction of actual solar heat gain of buildings in different climate regions.

Cpvlib: A comprehensive open-source tool for modeling CPV systems

The design and simulation of concentrator photovoltaic (CPV) systems necessitate precise modeling tools, for which some commercial and open-source options exist. However, when new technologies or applications need to be modeled, they can present some limitations: lack of documentation transparency and inability to extend existing models, or little flexibility to do it. For instance, the novel hybrid CPV/flat-plate module, conceived by Insolight and developed within the HIPERION project, required the ability to model integrated tracking and dual use of incident irradiance, which was not possible with existing tools. Addressing these issues, cpvlib is introduced as a comprehensive, open-source tool offering modular and adaptable functionalities for CPV-based systems, built as an extension of the popular pvlib python library.cpvlib's design enables the simulation of various CPV-based configurations, incorporating advanced architectures such as integrated tracking and hybrid CPV-flat plate modules. The library uses PVSyst's utilization factors to model deviations from the single-diode model, accounting for spectral and thermal effects. Its class structure leverages object-oriented programming principles, ensuring ease of use and extension.The validation of cpvlib is carried out through the modeling and long-term monitoring of Insolight's hybrid Si/III-V translucent planar micro-tracking modules, achieving a root mean square error of 3.5 % in case of Si cells and 2.7 % for III-V CPV cells. The tool accounts for complex behaviors like air mass impact on CPV performance, angle of incidence limits, and light spillage. The annual energy yield for a hybrid module is computed using typical meteorological year data, showcasing cpvlib's practical application.

Gas exchange in yellow passion fruit hybrids in the Semiarid region

Agronomic characterization and exploitation of the genetic variability in plants of the Passiflora can reveal important genetic resources because the Passiflora species grown under semiarid conditions make important contributions to breeding. The aim of this work was to evaluate the vegetative and physiological characteristics of fifteen yellow passion fruit hybrids in semiarid conditions. The experiment was conducted at IF Baiano – campus Guanambi, Bahia, Brazil. The 15 treatments were 10 genotypes: H09-10; GP09-02; H09-02; H09-14; H09-07; H09-09; FOP09; GP09-03; H09-30; FOP08 from the Active Germplasm Bank of the Genetic Breeding Program of Embrapa Cassava and Fruits, and five commercial hybrids: FB200; FB300; BRS SC; BRGA; BRS Rubi. The treatments were arranged in a randomized block design, with three replications and five observational units per plot. Vegetative characteristics (main branch length, number of functional leaves, number of nodes, and number of flower buds) were measured at full vegetative development, 90 days after transplanting (DAT). Hybrid H09-10 is the earliest in flowering, physiologically more efficient in the morning, closes stomata in the afternoon, regulates transpiration, and has lower leaf temperature, higher photosynthesis rate, and more efficient water use. Gas exchanges and photosynthesis rates, at 300 DAT, vary between hybrids and reading times: photosynthesis is higher in the morning while transpiration is greater in the afternoon. The reduction in carboxylation efficiency is related to non-stomatal factors. Gas exchange variables of the genotypes tend to be directly correlated with the photosynthetically active radiation incident on the leaf

Investigating the consistency of the shape and flux of X-ray reflection spectra in the hard state with an accretion disk reaching close to the black hole

Context. The observed spectra from black hole (BH) X-ray binaries (XRBs) typically consist of two primary components. A multitemperature blackbody originating from the accretion disk in the soft X-ray, and a power law-like component in the hard X-ray, due to the Comptonization of soft photons by the hot corona. The illumination of the disk by the corona gives rise to another key component known as reflection. A fraction of the incident hard X-ray radiation is naturally absorbed and re-emitted as a blackbody at lower energies and referred to as the “reprocessed blackbody”. Aims. For densities relevant to XRBs and typical ionization values, the reprocessed blackbody may become significant in the soft X-ray region (approximately 0.1–1.0 keV) and should be noticeable in the observed spectra as a consequence of reflection. The absence of any blackbody component in the low/hard state of a BH XRB may not be consistent with the reflection of highly irradiating flux, observed as a power law from an appropriately dense disk of XRB. Methods. We focus on the low/hard state of the BH XRB MAXI J1820+070. In contrast to previous works, we simultaneously fit the shape and flux of the reflection spectra. This allowed us to estimate the correct density and ionization of the slab as well as the corresponding reprocessed blackbody. Results. Our fitting of the representative observation of the BH XRB low/hard state suggests that the disk may, in principle, extend very close to the BH, even though the reprocessed thermal emission (due to disk illumination) remains cold (and thus low) enough to be consistent with the data in contrast to the results of a previous study. The inner reflection component is highly ionized and its fit is primarily driven by its contribution to the continuum, rather than by the shape of the relativistic iron line. Conclusions. The reprocessed blackbody cannot help determine whether the disk extends close to the BH or not in the hard state. For this specific observation, the flux in inner reflection component turns out to be quite low with respect to the outer reflection or power law. The outflowing slab corona covering the inner region of the disk could be the plausible geometry of the source, with the underlying disk approaching near to the BH.