Low-temperature Irradiation Research Articles

High-dynamic-range infrared radiometer based on chaos detection method

A High-dynamic-range infrared (IR) radiometer is essential for calibrating a wide-temperature-range IR radiation source. However, a low-temperature radiation source has very weak IR radiation which is easily submerged in noise. In this paper, a chaos detection method based on Diffing-Holmes oscillator (DHO) was adopted to enhance the ability of the IR radiometer for measuring weak IR radiation. The power measurement range of the radiometer was 2.9 × 10−9–5.9 × 10−2 W. The minimum SNR that was detected by the radiometer was as low as –22.46 dB. The noise during the measurement including the mismatch noise, the stray noise, and the detector noise were analyzed. The radiometer is calibrated by measuring a radiation source with adjustable temperature and aperture. The results show that the responsivity of the radiometer is 8.61257 × 104 V/W. The combined standard uncertainty of the radiometer is less than 1.66%. The IR radiometer introduced in this paper is capable of calibrating the IR radiation source of ultralow temperature, and has been applied in the ground test of a space-borne IR detection system.

English

The bell pepper (Capsicum annuum L.) is classified as a Solanaceae of economic importance with high nutritional value. However, its production is limited by abiotic factors such as low temperature and UV-B radiation, which can cause extensive damage to crops. Plants may respond to environmental stressors by inducing several morphological, physiological, biochemical and molecular changes. RNA-seq technique is widely applied to study the global gene expression in numerous processes related to plant biology, including responses induced by abiotic stress, providing relevant information about the genes and the pathways that participate in stress-induced responses. In this study, we analyzed the differential gene expression in response to combined stress of UV-B radiation and cold after exposure at 1, 3 and 25 h in stems from C. annuum plants, to gain deeper insights about the temporal dynamic of genes and pathways modulated by these factors. We found that 281, 280 and 326 genes were differentially expressed at 1, 3 and 25 h, respectively. Functional annotation revealed that most of genes were associated with hydrolase activity, stress response, stimulus response, carbohydrate metabolic process, and biosynthetic process. Based on KEGG pathway analysis, we found that circadian rhythm-plant, flavonoids biosynthesis and MAPK signaling pathway were statistically significant in almost all the sampling times. In conclusion, we found that several genes related to defense against pathogens and cell wall expansion were down-regulated, meanwhile the up-regulated genes were related to chloroplast protection, hormone and flavonoids biosynthesis, and compound transport. © 2021 Friends Science Publishers

Structural Evolution of a Zr–2.5% Nb Alloy during Long-Term Low-Temperature Neutron Irradiation

Structural Evolution of a Zr–2.5% Nb Alloy during Long-Term Low-Temperature Neutron Irradiation

Experimental and numerical simulations of compound heat transfer in an internally circulating fluidized bed

In this paper, the compound heat transfer of convection and radiation in an internal circulating fluidized bed for low temperature oxidation of pulverized coal was numerically simulated. The numerical prediction about the compound heat transfer characteristics and its relationship of convection and radiation was compared with the experimental measurements of low temperature radiation. The discrete ordinate model (DOM) was employed to investigate the radiation heat transfer in the low temperature oxidation internally fluidized bed, and user-defined function (UDF) was compiled by considering the effect of the particle flow emissivity on radiation heat transfer. The convection heat transfer coefficient increases with the increase of gas inlet volume flow rate and initial bed material height, however, thermal radiation coefficient was opposite. An increase of the thermal flux results in an increase of the surface temperature of the fluid and the heater surface, and the thermal transfer coefficient between bed material and heater surface is also increased. The results have the application reference to complex thermal transfer design of circulating fluidized bed systems wherein thermal radiation transfer must be considered as a significant mode.

BIOPROSPECTION OF UV-SCREENING COMPOUNDS FROM LICHENS INHABITING THE INDIAN STATE OF SIKKIM

Lichens show mutualistic relationship between algae/cyanobacteria and fungi and are found in diverse environmental conditions ranging from sea levels to high alpine elevations. They can tolerate and survive in harsh environmental conditions such as habitats having low temperature, desiccation, high temperature and ultraviolet radiation (UVR). Lichens have developed several photoprotective mechanisms such as light scattering, radiation screening, activation of antioxidants and macromolecules, thermal dissipation, membrane repair and synthesis of UV protective compounds such as despides, diphenyl ether, xanthones, anthraquinones, mycosporines, mycosporine-like amino acids (MAAs) and scytonemin to cope up with damaging UVR. MAAs are water-soluble molecules that absorb short wavelength solar UVR and disperse the energy as heat. Scytonemin is a small hydrophobic alkaloid pigment present in the extracellular sheath of several cyanobacteria as a protective mechanism against UVR. In the present study, bioprospection of lichen was done for screening of UV-absorbing compounds MAAs and scytonemin from different regions of Sikkim, India. Tentative identification and partial purification of these compounds was done with the help of high-performance liquid chromatography. Scytonemin showed absorption maxima at 252, 278, 385 nm and peaks at 347 and 410 nm showed the presence of scytonemin-3a-imine and gloeocapsin respectively. MAAs showed absorption maxima at 325.1 and 308 nm corresponding to mycosporine-NMA:Ser and mycosporine-taurine respectively. Scytonemin and MAAs display multiple roles, functioning as a potent UV-sunscreen and antioxidant molecules, and can be exploited in cosmetic and other industries for the development of novel drugs and pharmaceuticals, hence their bioprospection from different sources becomes crucial

Neutron irradiation induced defects and clustering in NF616 and T91

NF616 is a third-generation ferritic martensitic steel, developed to have better creep resistance than the prior generation T91. Unlike relatively numerous studies of T91, there is a lack of understanding of the irradiation effect on the microstructural evolution and mechanical response of NF616. This work evaluated the microstructures and radiation hardening of NF616 irradiated up to 8.2 displacement per atom (dpa) at 292 °C – 431 °C, compared with T91 from two heats. Dislocation loops were observed in all investigated samples. NF616 exhibited comparable loop size but slightly lower loop density than those in the general T91 heat at 430 °C. Cavities were only observed in NF616 at 431 °C but absent at lower irradiation temperatures (292 °C and 359 °C). Ni-rich clusters were also observed in NF616 at 431 °C, while only weak Ni-clustering were observed at lower irradiation temperatures. Compared to the general T91 heat, NF616 demonstrated better swelling resistance (e.g., one third of swelling in the general T91 heat at 430 °C), a slightly higher number density of Ni-rich clusters, and slightly lower radiation hardening. The low-carbon T91 showed the greatest hardening with the largest swelling and loop sizes, despite its lowest irradiation temperature and intermediate dose. The calculated hardening from loops, cavities and Ni-rich clusters using the classic dispersed barrier-hardening model had reasonable agreement with the experiment-derived results, with the primary hardening contribution attributed to dislocation loops.

Switchable wettability control of titanium via facile nanosecond laser-based surface texturing

Control of surface wettability is very important and useful for many industrial applications, and can be realized by controlling surface chemistry and microstructure simultaneously. Here, we present a facile laser-based surface texturing method to achieve switchable wettability control on titanium surface. The experimental results indicate that the laser-treated surfaces became superhydrophilic immediately upon laser texturing. Using alternate low-temperature heat treatment and UV irradiation, the wettability of the laser-treated surface could be efficiently switched between superhydrophilicity and superhydrophobicity for many times. Surface morphology and chemistry analyses confirm that the reversible wettability transition should be attributed to the combined effect of the dual-scale surface structure and controllable surface chemistry. Using the laser-based wettability control method, a water collection device was fabricated and demonstrated by a superhydrophobic-superhydrophilic hybrid surface pattern. The developed method could enable a practical throughput for large-area processing, and endow various industrial applications.

TVACPSO-assisted analysis of the effects of temperature and irradiance on the PV module performances

The time-varying acceleration coefficients particle swarm optimization method is employed to extract the physical parameters of the single diode PV model. Under the condition of low radiation and high temperature, there is a slight deviation between the calculated and the published data, but this model still has good accuracy in most ranges. The time-varying mechanism is introduced to mitigate the premature convergence problem and establish an appropriate tradeoff between the explorative and exploitative capabilities. The method provides the lowest cost function in the extraction of parameters. Although the experimental conditions of the curves cannot fully represent the working environment of the photovoltaic module, the validity of the model can be verified by comparing the calculated curves with the released curves. Analytical solutions of short-circuit current, open-circuit voltage, maximum power point current and voltage are also derived by the Lambert W function. The variation of maximum power, fill factor, energy efficiency, exergy efficiency and power conversion efficiency of the multi-crystalline and thin-film modules in the range of 10–70 °C were studied. The electrical performance of PV modules is more sensitive to temperature than irradiance. The output performance of thin-film modules is better than crystalline modules at high temperature conditions.

Effect of soybean crop structure on large crabgrass (Digitaria sanguinalis) growth and seed dormancy

AbstractCrop–weed interactions are affected by environmental alterations resulting from a crop’s presence, such as modifications in temperature, light quality and quantity, and moisture conditions that could modify weed performance. The objectives of this work were to study (1) how soybean [Glycine max (L.) Merr.] crop structure modifies the environment under the canopy and large crabgrass [Digitaria sanguinalis (L.) Scop.] plant structure, biomass, and seed production and dormancy; and (2) the relative importance of these environmental changes on the weed’s characteristics. A field experiment in a completely randomized block design with five replicates was performed to evaluate narrow and wide interrow spacing and soybean maturity groups 3 and 4. Measured variables were intercepted solar radiation (RAD); red–far red (R-FR) ratio; humidity; minimum, maximum, and alternating temperatures; and weed biomass, tillers per plant, height, and seed dormancy. Crop canopy reduced solar radiation, R-FR ratio, and daily average maximum and alternating temperatures. Soybean presence reduced the weed biomass, tillers and seeds per plant, and seed dormancy. High solar radiation intercepted by the crop during the reproductive phase was the main environmental variable related to reductions in weed biomass, tillers per plant, and fecundity. The combination of low temperature and solar radiation received by developing seeds was more related to seed dormancy than the rest of the variables. Crop management decisions focused on the fact that keeping the crop canopy alive for a longer time at the end of the season would not only reduce the weed growth but also seed dormancy.

Optimal COVID-19 infection spread under low temperature, dry air, and low UV radiation

The COVID-19 pandemic, caused by the novel coronavirus SARS-CoV-2, is spreading rapidly throughout the world, causing many deaths and severe economic damage. It is believed that hot and humid conditions do not favor the novel coronavirus, yet this is still under debate due to many uncertainties associated with the COVID-19 data. Here we propose surrogate data tests to examine the preference of this virus to spread under different climate conditions. We find, by mainly studying the relative number of COVID-19 deaths, that the disease is significantly (above the 95% confidence level) more common when the temperature is ∼10 °C, the relative humidity is ∼60%, the specific humidity is ∼5 g kg−1, and the ultraviolet radiation is less than ∼50 kJ m−2 (per hour). We also find, but less significantly, that the relative number of COVID-19 deaths is high when the wind is weak and low when the wind is strong. The results are supported based on global and regional data, spanning the time period from January to December 2020. The COVID-19 data includes the daily reported new cases and the daily deaths; for both, the population size is either taken into account or ignored.

Early-time symmetry quantifying with thin-shell capsule radiography for pulse shaped implosion

To achieve ignition with high gain in inertial confinement fusion, precise symmetry control is one of the key issues to guarantee the PdV work converting into the inner energy efficiently and maximize the pressure of the hot spot. The shaped pulse is used to maintain a low adiabat of the shell. A longer pulse and more compressible shell require more rigorous symmetry control, especially the driven symmetry during the picket pulse and main pulse. A surrogate capsule with high Z materials is usually used for the early-time symmetry tuning. The passive diagnosis of the re-emission spheres gives the time-resolved measurement of the first 2 ns, and the precision is mainly affected by the weak signals due to the low radiation temperature of the hohlraum. To compare with the re-emission technique with high Z surrogate capsule, we demonstrated the early-time symmetry tuning for picket pulse by using thin-shell capsule radiography technique. Combined with 1D hydrodynamics simulation and backlit imaging simulation, the driven asymmetry was quantified. A view factor assessment was also carried out by IRAD3D and coincided with the experimental consequences.

Low-Temperature Radiation Detectors Based on Ruthenium-Oxide Resistors

Bolometers based on industrial planar resistors were manufactured and studied. In the frequency range of 200–400 GHz, they showed a sensitivity of 6 × 10–12 Ω/W (which corresponds to a power of absorbed radiation of ~10 pW at a measuring current of about 1 nA) in the dynamic range of ~30 dB at an operating temperature of 0.3 K. By comparing the detector response to incident radiation with the response to a change in its resistance with increasing the direct current power, it is possible to determine the absolute power of absorbed radiation with an accuracy of 10–20%. The time constant of the used ruthenium-oxide detectors, depending on the substrate thickness, is ~0.1–2 s.

Evolution of δ ferrite in a CF3 cast stainless steel upon neutron irradiation to 3, 5, 10, 20, and 40 dpa

The microstructural evolution of delta ferrite in a CF3 cast stainless steel irradiated to 3, 5, 10, 20, and 40 dpa with two dose rates was studied with atom probe tomography (APT) and transmission electron microscopy. Spinodal decomposition and G-phase precipitates induced by neutron irradiation and thermal aging were quantified systematically. The neutron irradiation significantly enhances the spinodal decomposition in delta ferrite as both the spinodal wavelength (i.e. a characteristic repeat distance) and amplitude (i.e. magnitude of elemental concentration fluctuation) increase after irradiation. The wavelength only varies slightly when the dose increases from 5 to 40 dpa, while the amplitude increases dramatically from 10 to 20 dpa and starts to saturate before 20 dpa. The dose rate and irradiation temperature also have a notable effect on the spinodal wavelength and amplitude. The study shows that higher dose rate promotes a larger wavelength at given irradiation doses. Regarding the G-phase precipitates, a slightly lower irradiation temperature would result in a smaller mean size of G-phase precipitates, while a lower irradiation dose rate would lead to a larger G-phase precipitates at a given temperature and dose. Overall, the spinodal decomposition and G-phase precipitates in the delta ferrite continue to evolve with the increasing dose beyond 10 dpa. This study confirms that the formation of G-phase precipitates at the interdomain region between alpha and alpha-prime is facilitated by the Si and Mo atoms rejected from Fe rich alpha phase and the Ni and Mn atoms rejected from Cr rich alpha-prime phase. Neutron irradiation plays a dominant role in the ferrite instability, and the effect of prior thermal aging at 400°C for 10,000 hours is negligible as the dose is 3 dpa and above.

Hydrothermal corrosion of laser printed SiC fibers under extreme environment

SiC/SiC fiber composites are proposed cladding materials to improve the accident tolerance of commercial light water nuclear reactor fuel. To evaluate their viability, understanding the kinetics of corrosion under irradiation and high-temperature, high-pressure aqueous environment is critical. In the present work, the microstructure and mechanical properties of novel SiC fibers manufactured by Laser Chemical Vapor Deposition (LCVD) are introduced. The LCVD technology has control over microstructure and stoichiometry while allowing for high purity manufacturing, all key qualities needed in search of an optimum SiC fiber for nuclear energy applications. The isolated hydrothermal corrosion of commercially available carbon-rich Hi-Nicalon Type-S fibers is compared to the LCVD stoichiometric and LCVD silicon-rich fibers. Autoclave testing was carried out at 310°C and 14 MPa in the absence of irradiation. In a separate study, the effect of gamma irradiation on the fibers in the room-temperature environment was analyzed. It was observed from the experiments that the dissolution of the fibers was highly dependent on the stoichiometric ratio, fiber surface morphology and thermal pre-treatment of fibers. Contrary to previous findings, fiber dissolution was also visible under low-temperature gamma irradiation in aqueous environment with LCVD fibers showing lower dissolution.

Native Species Facing Climate Changes: Response of Calafate Berries to Low Temperature and UV Radiation.

Calafate (Berberis microphylla G. Forst) is a wild bush plant widely distributed in the south of Argentina and Chile. Their blue colored fruits present particular flavor and health benefits attributed to high polyphenol contents biosynthesized by the plant under stress. Studies about correlation of abiotic conditions with anthocyanin profiles and physicochemical features of calafate beneath wild origin environment are not described yet. Hence, this research aimed to evaluate the physicochemical changes, antioxidant activity and anthocyanin content of calafate fruit in relationship to UV solar radiation (W.m−2) and air temperature (°C) environment condition during three consecutive years (2017, 2018, 2019). Variations in fruit anthocyanins were determined by comparison between high performance liquid chromatography (HPLC-DAD-ESI)/MSn and CIEL*a*b* colors parameters. Correlations were analyzed by principal component analysis (PCA). Radiation was negatively correlated with fruit size and weight. Physicochemical aspects such as pH, soluble solids, color, total anthocyanins, flavanols and other phenolic compounds were positively correlated with temperature changes. The quantities of monomeric anthocyanins were dependent on both low temperature and global radiation (reaching 20.01 mg g−1 FW in calafate fruit). These results constitute a valuable resource to understand the structural and physiological plasticity of calafate in facing climate changes for future domestication research as well as for agri-food industrial application.

Helium Causing Disappearance of ½ a<111> Dislocation Loops in Binary Fe-Cr Ferritic Alloys

Single and dual-beam self-ion irradiations were performed at 500 °C on ultra-high purity Fe14%Cr alloy to ~0.33 displacements-per-atom (dpa), and 0 or 3030 atomic-parts-per-million (appm) helium/dpa, respectively. Using transmission electron microscopy, we reveal that helium can drastically modify the dislocation loop Burgers vector in Fe-Cr alloys. Helium co-implantation caused complete disappearance of a/2 type dislocation loops, and the microstructure consisted of only a loops. Conversely, a/2 type loops were predominant without He co-implantation. The total loop density remained largely unaffected. The results strikingly contrast literature asserting that helium stabilizes a/2 type loops in bcc Fe alloys, based on low temperature irradiations. Collectively analyzing the results with literature suggests that the small positive interaction between helium and self-interstitial atoms (SIA) in Fe, predicted by atomistic simulations, maybe insufficient to holistically explain the dislocation loop microstructure development in presence of helium. Helium-SIA positive binding inadvertently implies elevated a/2 loop fraction and higher loop densities that the present results contradict. Helium induced high cavity density causing a preferential loss of highly glissile clusters, leaving the matrix saturated with type clusters is proposed as a potential mechanism. Further, the in-situ irradiations combined with Burgers vector analysis strengthened the evidence of Cr-induced dislocation loop mobility reduction that appears to stabilize the a/2 type loops and causes higher loop densities in Fe-Cr alloys.

Experimental study on the influence of temperature and radiation on photovoltaic power generation in summer

The power generation of photovoltaic systems is random and uncertain, which is the result of a variety of factors. However, there are few studies considering the interaction of two or more factors at the same time. Therefore, the influence of air temperature and radiation on photovoltaic power generation is considered in this paper, and based on the physical system, the experimental data is processed and analyzed through SPSS and DPS data analysis software and the multiple nonlinear regression analysis model. The processing results show that whether it is the quadratic and cubic nonlinear regression equations or the quadratic and cubic trend surface fitting degrees all reach a significant level, it can be used to reveal the law of the influence of two factors on the power generation under the test environment. The analysis results found that the combined effect of temperature and radiation on photovoltaic power generation is more complicated, but the overall impact of solar radiation is significant and greater than the air temperature; low temperature and high radiation, high temperature and high radiation and low radiation conditions have side effects on photovoltaic power generation; when the two are enhanced at the same time, it will help increase the photovoltaic power generation; when the two “one increase and one decrease”, the photovoltaic power generation first increases and then decreases, and there is an optimal air temperature, solar radiation, and maximum photovoltaic power generation.

The impacts of ambient temperature and ultraviolet radiation on the incidence of herpes zoster: An ecological study in Taiwan.

The aim of the study was to examine the relationship between ambient temperature, ultraviolet radiation, and the development of herpes zoster in Taiwan. An ecological study was conducted to analyse the database of the Taiwan National Health Insurance Programme. Participants aged ≥20years with newly diagnosed herpes zoster between 2003 and 2012 were selected for analysis. The monthly incidence rate of herpes zoster was measured between 2003 and 2012. Monthly average ambient temperature in Celsius (°C) between 2003 and 2012 was measured according to the official database of the Central Weather Bureau in Taiwan. Monthly accumulated ultraviolet radiation (MJm-2 ) between 2003 and 2012 was measured according to the official database of the Environmental Protection Administration in Taiwan. The overall incidence rates of herpes zoster ranged from 2.54 to 5.67 per 10000 persons per month from 2003 to 2012.The monthly average ambient temperature was higher and the monthly accumulated ultraviolet radiation was stronger from May to October. The incidence rates of herpes zoster seemed to be high during the period of high ambient temperature and strong ultraviolet radiation (from May to October).Whenever ambient temperature increased 1°C per month, the incidence rate of herpes zoster increased by 0.072 per 10,000 persons per month. Whenever ultraviolet radiation increased 1MJm-2 per month, the incidence rate of herpes zoster increased by 0.313 per 10000 persons per month. There is a significant association between ambient temperature, ultraviolet radiation, and the development of herpes zoster in Taiwan. The incidence rate of herpes zoster is high during the period of high ambient temperature and strong ultraviolet radiation. Low ambient temperature and weak ultraviolet radiation might be beneficial for the prevention of herpes zoster.

The Effect of Photoperiod Genes and Flowering Time on Yield and Yield Stability in Durum Wheat.

This study analysed the effect of flowering time as influenced by photoperiod sensitivity genes on yield and yield stability in durum wheat. Twenty-three spring genotypes harbouring different allele combinations at Ppd-A1 and Ppd-B1 were grown in 15 field experiments at three sites at latitudes from 41° to 19° N (Spain, Mexico-North and Mexico-South). Low temperature and solar radiation before flowering and long day length during grain-filling characteristic for the Spanish site resulted in high grain number/m2 (GN) and yield (GY), while a moderate GN combined with high solar radiation during grain-filling at Mexico-North led to heavier grains. Allele combination GS100-Ppd-A1a/Ppd-B1a reduced the flowering time up to nine days when compared with Ppd-A1b/Ppd-B1a. Differences in flowering time caused by Ppd-A1/Ppd-B1 allele combinations did not affect yield. Combinations GS105-Ppd-A1a/Ppd-B1b and Ppd-A1b/Ppd-B1b resulted in the highest GN, linked to spikelets/spike, which was higher in GS105-Ppd-A1a/Ppd-B1b due to more grains/spikelet. Flowering time caused by Eps had a minor effect on GN, spikes/m2 and grains/spike, but late flowering resulted in reduced grain weight and GY. Allele combinations harbouring alleles conferring a similar photoperiod sensitivity response at Ppd-A1 and Ppd-B1 resulted in greater yield stability than combinations that carry alleles conferring a different response. Allele combination GS100-Ppd-A1a/Ppd-B1a was the most suitable in terms of yield and yield stability of durum wheat cultivated under irrigation within the studied latitudes.

Investigation of a root zone heating system for greenhouse seedling and its effects on micro-environment

Under the extremely cold climatic condition, crops have to survive severe heat stress conditions, even if they are being kept in greenhouses. In the winter and spring of North China, the air and soil temperature is low inside the greenhouse, and when using a traditional heating system, the energy consumption is high. This paper reports on a study of different design solutions for a root zone heating system based on a kind of low temperature radiation material. Root zone heating systems offer increasing crop quality and productivity. A novel type of heat preservation and root zone heating system was applied in greenhouse seedling. And through multiple experiments, the effect of the root zone heating system on the ambient environment and seedbed surface was studied, and the heat preservation effect and heating uniformity were discussed. Results show that single-layer film covering on the root zone heating system can make the average temperature at night increase 1°C. And the average seedbed surface and substrate temperature can increase 11.3°C and 5.2°C, respectively. In conclusion, the root zone heating system can effectively improve the environmental temperature of seedling and the uniformity of heating is high, which provides a strong guarantee for high-quality seedling cultivation. Keywords: greenhouse, root zone heating system, micro-environment, seedling, substrate temperature, air temperature DOI: 10.25165/j.ijabe.20201306.5905 Citation: He F, Hou Y, Li K, Wei X M, Liu Y Q. Investigation of a root zone heating system for greenhouse seedling and its effects on the micro-environment. Int J Agric & Biol Eng, 2020; 13(6): 47–52.