Simulation of the Ecosystem Productivity Responses to Aerosol Diffuse Radiation Fertilization Effects over the Pan-Arctic during 2001–19

The pan-Arctic is confronted with air pollution transported from lower latitudes.Observations have shown that aerosols help increase plant photosynthesis through the diffuse radiation fertilization effects(DRFEs).While such DRFEs have been explored at low to middle latitudes,the aerosol impacts on pan-Arctic ecosystems and the contributions by anthropogenic and natural emission sources remain less quantified.Here,we perform regional simulations at 0.2o×0.2ousing a well-validated vegetation model(Yale Interactive terrestrial Biosphere,YIBs)in combination with multi-source of observations to quantify the impacts of aerosol DRFEs on the net primary productivity(NPP)in the pan-Arctic during 2001-19.Results show that aerosol DRFEs increase pan-Arctic NPP by 2.19 Pg C(12.8%)yr^(-1)under clear-sky conditions,in which natural and anthropogenic sources contribute to 8.9% and 3.9%,respectively.Under all-sky conditions,such DRFEs are largely dampened by cloud to only 0.26 Pg C(1.24%)yr^(-1),with contributions of 0.65% by natural and 0.59% by anthropogenic species.Natural aerosols cause a positive NPP trend of 0.022% yr^(-1)following the increased fire activities in the pan-Arctic.In contrast,anthropogenic aerosols induce a negative trend of-0.01% yr^(-1)due to reduced emissions from the middle latitudes.Such trends in aerosol DRFEs show a turning point in the year of 2007 with more positive NPP trends by natural aerosols but negative NPP trends by anthropogenic aerosols thereafter.Though affected by modeling uncertainties,this study suggests a likely increasing impact of aerosols on terrestrial ecosystems in the pan-Arctic under global warming.

The Performance of Downward Shortwave Radiation Products from Satellite and Reanalysis over the Transect of Zhongshan Station to Dome A, East Antarctica

The downward shortwave radiation(DSR) is an important part of the Earth's energy balance, driving Earth's system's energy, water, and carbon cycles. Due to the harsh Antarctic environment, the accuracy of DSR derived from satellite and reanalysis has not been systematically evaluated over the transect of Zhongshan station to Dome A, East Antarctica.Therefore, this study aims to evaluate DSR reanalysis products(ERA5-Land, ERA5, MERRA-2) and satellite products(CERES and ICDR) in this area. The results indicate that DSR exhibits obvious monthly and seasonal variations, with higher values in summer than in winter. The ERA5-Land(ICDR) DSR product demonstrated the highest(lowest) accuracy,as evidenced by a correlation coefficient of 0.988(0.918), a root-mean-square error of 23.919(69.383) W m^(–2), a mean bias of –1.667(–28.223) W m^(–2) and a mean absolute error of 13.37(58.99) W m^(–2). The RMSE values for the ERA5-Land reanalysis product at seven stations, namely Zhongshan, Panda 100, Panda 300, Panda 400, Taishan, Panda 1100, and Kunlun, were 30.938, 29.447, 34.507, 29.110, 20.339, 17.267, and 14.700 W m^(-2), respectively;with corresponding bias values of 9.887, –12.159, –19.181, –15.519, –8.118, 6.297, and 3.482 W m^(–2). Regarding seasonality, ERA5-Land, ERA5,and MERRA-2 reanalysis products demonstrate higher accuracies during spring and summer, while ICDR products are least accurate in autumn. Cloud cover, water vapor, total ozone, and severe weather are the main factors affecting DSR. The error of DSR products is greatest in coastal areas(particularly at the Zhongshan station) and decreases towards the inland areas of Antarctica.

High-Order Spatial FDTD Solver of Maxwell’s Equations for Terahertz Radiation Production

We applied a spatial high-order finite-difference-time-domain (HO-FDTD) scheme to solve 2D Maxwell’s equations in order to develop a fluid model employed to study the production of terahertz radiation by the filamentation of two femtosecond lasers in air plasma. We examined the performance of the applied scheme, in this context, we implemented the developed model to study selected phenomena in terahertz radiation production, such as the excitation energy and conversion efficiency of the produced THz radiation, in addition to the influence of the pulse chirping on properties of the produced radiation. The obtained numerical results have clarified that the applied HO-FDTD scheme is precisely accurate to solve Maxwell’s equations and sufficiently valid to study the production of terahertz radiation by the filamentation of two femtosecond lasers in air plasma.

Evaluation on Solar Radiation Resource and Photosynthetic and Thermal Potential Productivity in Shandong Province

To evaluate scientifically the change of photosynthetic and thermal potential productivity caused by climate variation,based on comparison with mean of previous 30 years(1971-2000),the change of total solar radiation,sunshine hours,photosynthetic active radiation,photosynthetic and thermal potential productivity since 2001 were analyzed through data of radiation,sunshine and temperature in Shandong Province from 1971 to 2007,and the change trend was also tested by Mann-Kendall non-parametric statistical met...

Gaseous products generated by radiation degradation of N,N-diethylhydroxylamine aqueous solution

In this paper,gaseous products generated by radiation degradation of N,N-diethylhydroxylamine (DEHA) in aqueous solution are studied.The results show that by 10～1000 kGy irradiation of the solution in DEHA concentration of 0.1～0.5 mol·L^(-1),the gaseous products were mainly hydrogen,methane,ethane and ethene.The volume fraction of hydrogen did not change much with different concentrations of DEHA.The volume fraction of methane and ethane decreased,but that of ethene increased,with increasing DEHA concentration.The volume fraction of hydrogen,methane and ethane increased with the dose.The relationship of the volume fraction of ethene with the dose had something to do with the DEHA concentration.

Identification of radiolytic products of [C_4mim][PF_6] under γ-irradiation

The trace water-soluble radiolytic products of neat 1-butyl-3-methylimidazolium hexafluorophosphate([C4mim][PF6]) were identified by analysing water-washed samples of γ-irradiated ionic liquids. HF and difluorophosphinic acid were confirmed as the main radiolytic products of [C4mim][PF6], and their radiation chemical yields were quantified by19 F NMR(G(F-) = 0.14 μmol/J, G(HOP(O)F2) = 0.053 μmol/J). Compared to [C4mim][NTf2], [C4mim][PF6] shows better radiation stability.

Gaseous products of aqueous N,N-dimethyl hydroxylamine degraded by radiation

In this work,the 0.1-0.5 mol·L-1 N,N-dimethylhydroxylamine(DMHA) were irradiated to 5-25 kGy,and gaseous products of mainly hydrogen,methane,ethane and n-butane were measured by gas chromatography.The results show that the volume fraction of hydrogen and methane increases with the concentration of DMHA and dose,and the latter does not change markedly at high doses.

Comparison of experimental and theoretical radiation shielding parameters of several environmentally friendly materials

In this study, the gamma radiation shielding features of several environmentally friendly materials were investigated. For this purpose, several attenuation parameters, such as the mass attenuation coefficient (l=q), radiation protection efficiency (RPE), and effective atomic number (Zeff) were determined experimentally and compared with numerical data obtained using WinXCom software. In the measurements, the emitted gamma photons were counted by a gamma spectrometer equipped with an HPGe detector using 22Na, 54Mn, 57Co, 60Co, 133Ba, and 137Cs radioactive point sources in the energy region of 81–1333 keV. The obtained results indicate that the l=q and RPE values of the samples decrease with an increase in photon energy. The experimental values are in good agreement with those obtained using WinXCom software. The RPE and Zeff results show that among the studied materials, the NaY0.77Yb0.20Er0.03F4 sample has the best gamma radiation shielding effectiveness.

STUDY ON IMMOBILIZED YEAST CELLS WITH HRDROPHILIC POLYMER CARRIER BY RADIATION - INDUCED COPOLYMERIZATION

In this paper, various kinds of monomers 2-hydroxyethyl methacrylate (HEMA), 2-hydroxyethyl acrylate (HEA), hydroxypropyl methacrylate (HPMA) and methoxy polyethylene glycol methylacrylate (M-23G) were eopolymerized by radiation technique at low temperature (-78℃) and several kinds of copolymer carriers were obtained. Yeast cells were immobilized through adhesion and multiplication of yeast cells themselves on these carriers. The etharol productivity of immobilized yeast cells with these carriers was related to the monomer composition and water content of copolymer carriers and the optimum monomer composition was 20%:10% in poly (HEA-M23G). In this case, the ethanol productivity of immobilized yeast cells was 26 mg /( ml·h), which was 4 times as high as that of free cells. In this study, the effect of adding of crosslinking reagent (4G) in copolymer on activity of yeast cells immobilized with the carriers were also studied. It was found that the effect of adding crosslinking reagent (4G) in lower monomer composition of poly(HEA-M23G) on the ethanol productivity of immobilized cells was better than that in higher one in this work.

Radiation effects and radioprotection by Thai medicinal plants in mouse macrophage cell line

Objective:To investigate the effects of radiation on growth-arrested(GA) and micronucleus-production(MP) rates,and the radioprotective properties of Thai medicinal plants in mouse macrophage cell line RAW264.7 in vitro.Methods:Mouse macrophage cell line(RAW264.7) was cultured in vitro.Various radiation exposures, growth-arrested rate assay,micronucleus production assay,and radioprotection by Thai medicinal plants were performed.Results:The results showed that GA and MP rates forγ-rays and UV were dose-dependent. The 50%-affected dose ofγand UV radiation for the GA rate was 10 Gy and 159 microwatt/cm for 0.5 seconds, respectively.After X-ray exposure,there was no apparent effect on RAW264.7 cells,even with a fortyfold human diagnostic dose.Two exposures toγradiation at 20 Gy resulted in a significantly higher MP rate than 20 Gy single exposure or control(P【0.05).The Thai medicinal plants(Kamin-chun capsules,Curcuma longa Linn;Hed lingeu,Ganoderma lucidum;Ya Pakking capsule,Murdannia loriformis) could not prevent cell damage,but epigallocatechin gallate and L-cysteine could provide protection from 2 Gyγ-ray exposure. Conclusion:γradiation caused chromosomal damage during cell division and UV caused cell death, while X-ray radiation was safe.The radioprotective effects of Thai medicinal plants,Kamin-chun,Hed lingeu, and Ya Pakking,could not prevent cell damage in this study.

Reduction of radiation exposure in catheter ablation of atrial fibrillation: Lesson learned

Over the last decades, the concern for the radiation injury hazard to the patients and the professional staff has increased in the medical community. Since there is no magnitude of radiation exposure that is known to be completely safe, the use of ionizing radiation during medical diagnostic or interventional procedures should be as low as reasonably achievable(ALARA principle). Nevertheless, in cardiovascular medicine, radiation exposure for coronary percutaneous interventions or catheter ablation of cardiac arrhythmias may be high: for ablation of a complex arrhythmia, such as atrial fibrillation, the mean dose can be > 15 m Sv and in some cases > 50 m Sv. In interventional electrophysiology, although fluoroscopy has been widely used since the beginning to navigate catheters in the heart and the vessels and to monitor their position, the procedure is not based on fluoroscopic imaging. Therefore, nonfluoroscopic three-dimensional systems can be used to navigate electrophysiology catheters in the heart with no or minimal use of fluoroscopy. Although zerofluoroscopy procedures are feasible in limited series, there may be difficulties in using no fluoroscopy on a routine basis. Currently, a significant reduction in radiation exposure towards near zero-fluoroscopy procedures seems a simpler task to achieve, especially in ablation of complex arrhythmias, such as atrial fibrillation. The data reported in the literature suggest the following three considerations. First, the use of the non-fluoroscopic systems is associated with a consistent reduction in radiation exposure in multiple centers: the more sophisticated and reliable this technology is, the higher the reduction in radiation exposure. Second, the use of these systems does not automatically lead to reduction of radiation exposure, but an optimized workflow should be developed and adopted for a safe non-fluoroscopic navigation of catheters. Third, at any level of expertise, there is a specific learning curve for the operators in the non-fluoroscopic manipulation of catheters; however, the learning curve is shorter for more experienced operators compared to less experienced operators.

Solar radiation and atmospheric dynamics

This paper studies the problems of mathematical description of physical processes in open non-equilibrium atmosphere. It is proposed that the mathematical description should be based on the idea that properties of an open system are determined by the properties of its elements and external constraints. It is also explained why atmosphere should be represented by an open non-equilibrium system of gas and radiation. Difference between physical processes in the above mentioned system and equilibrium atmosphere is given. The modification of equations of non-equilibrium thermodynamics for a system of gas and radiation is proposed. Possible ways for further development of tools of non-equilibrium thermodynamics are considered.

Radiation Resistance of Tar Fractions of Bituminous Oil

The results of studies of radiation chemical transformations of Balakhani bituminous oil of Azerbaijan are adduced. The IR （infrared） spectra of initial and irradiated samples of tar fractions of bituminous oil are compared. The kinetics of radiation chemical yields of gas products at the irradiation of bituminous oil and its tar fraction have been investigated. Irradiation is conducted in the gamma-ray source of isotope 60Co at the dose rate of P = 0.27 Gy/s and absorbed doses D = 5-163 kGy. It is found that in comparison with oil faction, tar fraction of bituminous oil has a high resistance to radiation.

Numerical Simulation for the Efficiency of the Produced Terahertz Radiation by Two Femtosecond Laser Pulses: Above-Threshold-Ionization

The tunneling ionization (TI) is the most dominated ionization process in the production of terahertz radiation by two femtosecond lasers, although its validity above the ionization threshold of some gases is uncertain. In the present research, we employ a 1D fluid code to simulate the efficiency of the produced terahertz radiation by two femtosecond laser beams in air plasma. Two ionization models in the context of the TI process which are the Ammosov-Delone-Krainov (ADK) for noble gases and its developed molecular ADK (MO-ADK) model for molecular gases are intrinsically used to conduct this study. The main target of the present research is to examine the validity of these models Above-Threshold-Ionization (ATI) of these gases. For this purpose, we simulated the ionization rate and the power spectrum of the produced radiation, in addition we numerically evaluated the efficiency of the produced radiation as function of the input beams intensity at particular energy fraction factor, relative phase and initial pulse duration of these beams. These calculations conducted for a selected noble gas at varying energy levels and a chosen molecular air plasma gas at different quantum numbers. Numerical results near and above the ionization threshold of the selected gases have clarified that the ADK and MO-ADK model are successful valid to study the efficiency of the produced THz radiation at low energy levels and small quantum numbers of the selected gases, meanwhile, with any further increase in the energy level and the quantum number values of these gases, both of the ADK and MO-ADK are failed to correctly analyze the efficiency process and estimate its fundamental parameters.

Radiation effects on physically cross-linked agarose hydrogels

As a potential matrix of three-dimensional gel dosimeter, agarose hydrogels will be used for measuring radiation doses, hence the importance of studying their radiation resistance and radiolysis mechanism. Physical property and chemical structure of physically cross-linked agarose hydrogel samples irradiated to 0–200 k Gy by60 Co γ-rays were analyzed by universal testing machine, gel permeation chromatography, fourier transform infrared spectrometer, ultraviolet visible spectroscopy, nuclear magnetic resonance, and gas chromatography. The results showed that agarose hydrogels had good radiation stability below 25 k Gy, and the maximum compression strength of sample was ca. 0.1 MPa at 25 k Gy. The irradiated samples degraded obviously and liquefied gradually with increasing doses. Compared with unirradiated sample, carbonyl groups, which generated from the molecular chains of agarose hydrogels, were observed at 25 k Gy and increased gradually with dose. The main gas products evolved from irradiated agarose hydrogels were H2, CO2, CO and CH4. Based on the analysis of radiolytic products, the radiolysis mechanism of agarose hydrogels under γ-radiation was proposed.

In Vitro Evaluation of Gamma Irradiation on a Gel Formulation of Cratylia Mollis: Rheological Proporties and Microbiological Control

Lectin Cramoll-1,4, obtained from Cratylia mollis seeds (beans camaratu) was structurally characterized, biologically and pharmacologically, but its use as a biopharmaceutical is not well documented. The objective of this study is to propose a biopharmaceutical formulation lectin Cramoll-1,4, test their hemagglutinating properties in vitro as well as the use of gamma radiation as a continuous process of decontamination formulation. It was made of the extraction and purification Cramoll-1,4, was developed a gel formulation using Carbopol? as a vehicle, at concentrations of 50, 100, 200, 300 and 600 μg was irradiated with 60Co gamma rays in a dose of 7.549 kGy·h–1. The proposed formulation at a concentration of 300 μg produced an increase in the hemagglutinating units Cramoll-1,4 due to the synergistic effect caused by gamma radiation. Considering the diverse use of lectins, specific molecular and structural factors, as well as changes resulting from its formulation, concentration, irradiation and route of administration is of utmost importance to continue the studies in vitro, for subsequent application in vivo to characterize the physiological and molecular processes involved in the response and cellular effects.

Experimental Study on Improving Performance and Productivity of Pyramid Solar StillUsing Rotation Technique

Globally,potable water scarcity is pervasive problem.The solar distillation device is a straightforward apparatus that has been purposefully engineered to convert non-potable water into potable water.The experimental study is distinctive due to the implementation of a rotational mechanism within the pyramidal solar still(PSS),which serves to enhance the evaporation and condensation processes.The objective of this research study is to examine the impact of integrating rotational motion into pyramidal solar stills on various processes:water distillation,evaporation,condensation,heat transfer,and energy waste reduction,shadow effects,and low water temperature in saline environments.Ultimately,the study aims to enhance the production of distilled water.An economic evaluation was undertaken in order to ascertain the extent of cost reduction.Experiments measuring freshwater productivity and thermal performance were conducted over a three-month period at the University of Science and Technology in Tehran.The entire pyramid structure was rotated using a direct current motor driven by a photovoltaic cell.The research methodology entailed the operation of a PSS with varying rotational speeds(0.125,0.25,1,and 1.5 rpm)and without rotation,from 9 am to 4 pm.The findings suggested that the productivity of the distillation apparatus in terms of distilled water increased as the rotation speed rose,with the most pronounced increase occurring at 1 rpm in comparison to the other conditions.The presence of turbulence in the water enhanced the heat transfer occurring between the absorber plate and thewater.At 2:00 p.m.on an experimental day,this effect was observed when the absorber plate temperature reached 79.1°C at 1.5 rpm.In contrast,its temperature decreased to 78°C when not in a state of rotation,as the intensity of solar radiation was higher in the non-rotation state.At 1 rpm,the solar pyramid distiller achieved a 30.2%increase in output compared to its non-rotating state.At 1 rpm,the distiller achieved a 20.6%increase in output compared to 0.25 revolutions per minute.In addition to the control condition,the thermal efficiency of the solar still varied as follows:at 1,1.5,0.25,and 0.125 rpm,it was 46.2%;at 44.2%,37.8%;at 35.3%;and at 36.6%,respectively.Furthermore,distilled water generated by a pyramid solar still with rotation(PSSR)is priced at$0.03 per liter,whereas it costs$0.0317 per liter when produced by a pyramid solar still without rotation(PSS without R).

Estimation of Net Primary Productivity of Terrestrial Vegetation in China by Remote Sensing

Among the many approaches for studying the net primary productivity (NPP), a new method by using remote sensing was introduced in this paper. With spectral information source (the visible band, near infrared band and thermal infrared band) of NOAA-AVHRR, we can get the relative index and parameters, which can be used for estimating NPP of terrestrial vegetation. By means of remote sensing, the estimation of biomass and NPP is mainly based on the models of light energy utilization. In other words, the biomass and NPP can be calculated from the relation among NPP, absorbed photosynthetical active radiation (APAR) and the rate (epsilon) of transformation of APAR to organic matter, thus: NPP = ( FPAR x PAR) x [epsilon * x sigma (T) x sigma (E) x sigma (S) x (1 - Y-m) x (1 - Y-g)]. Based upon remote sensing ( RS) and geographic information system (GIS), the NPP of terrestrial vegetation in China in every ten days was calculated, and the annual NPP was integrated. The result showed that the total NPP of terrestrial vegetation in China was 6.13 x 10(9) t C . a(-1) in 1990 and the maximum NPP was 1 812.9 g C/m(2). According to this result, the spatio-temporal distribution of NPP was analyzed. Comparing to the statistical models, the RS model, using area object other than point one, can better reflect the distribution of NPP, and match the geographic distribution of vegetation in China.

Recognizing production options for pearl millet in Pakistan under changing climate scenarios

Climate change is making the lands a harsher environment all over the world including Pakistan. It is expected to oppose us with three main challenges： increase in temperature up to 2-5℃ （heat stress）, increasing water stress and severe malnourishment due to climate change. It has been foreseen that there will be a 10% increase of dryland areas with climate change in the world, with more variability and incidences of short periods of extreme events （drought and heat stress）. Pearl millet is a hardy, climate smart grain crop, idyllic for environments prone to drought and heat stresses. The crop continues to produce highly nutritious grain sustainably, thereby encouraging the fight against poverty and food insecurity due to its resilience. The crop is more responsive to good production options （planting time, planting density, inter/intra row spacing, nitrogen application and irrigation）. It has high crop growth rate, large leaf area index and high radiation use efficiency that confers its high potential yield. In most of the cases, pearl millet is remained our agricultural answer to the climate calamity that we are facing, because it is selected as water saving, drought tolerant and climate change complaint crop. In view of circumstances, pearl millet cultivation must be retrieved by recognizing production options in context to changing climate scenarios of Pakistan using crop modeling techniques.

Model of Plant Productivity and a Computer System for Optimization of Agro-Technology Using the Method of Exergic Analysis

A model of a potentially effective type energy-resource-saving of optimization of agro-technologies, based on the principle subordination of synergetics, was established. There was developed computer system energy-resource-saving optimization of agricultural technologies. The main feature of crop production is provided by the plants which themselves are self-organizing organisms. This allows us to adopt the principle of subordination of synergetics as the basis of the model. The value of free energy at the input into plants, estimated by the process of photosynthesis, is equal to the value of “radiation exergy for plant growth”. Assessment of the use of radiation energy is carried out based on the energy-converting characteristics of plants, which were obtained in climate chambers under controlled conditions. We used the model based on the principle of subordination of synergetics to develop common quantitative mutually agreed definitions of the main agroecological variables: Agroclimatic and Meliorative potentials of lands, their fertility, and potential (maximum) productivity of plants under different environment conditions.