Absorption Factor Research Articles

Monitoring, Diffusion and Source Speculation Model of Urban Soil Pollution

The rapid industrialization of cities has brought many challenges to the environment and resources. Industrial wastes, automobile exhaust, coal combustion soot and other pollutants accumulate in urban soil, and the characteristics of urban soil are changed, causing many pollutants to accumulate in the urban soil environment. Heavy metals are toxic and harmful pollutants existing in soil that cannot be biodegraded or thermally degraded; thus, heavy metals pose a threat to environmental quality and humans. To solve the environmental pollution of soil heavy metals, we utilize kriging interpolation to determine the geological distribution of the environmental pollution of metal elements and analyze the main causes of soil heavy metal pollution. Next, the propagation characteristics and diffusion process of heavy metal pollutants are thoroughly analyzed; in addition, an improved one-dimensional convective dispersion model and an improved air subsidence model are established, and real urban soil data are taken as an example for the fitting test. The results show that the improved models that consider more factors, such as adsorption or decomposition factors during the process of convective dispersion, absorption and expulsion factors of the crop root and topographic factors and height changes during the process of air subsidence, are effective. This paper is helpful for distinguishing the primary pollution sources and migration routes of soil metal element pollution and provides a certain reference value for protecting the environment and reducing heavy metal pollution.

Thermal behavior investigation of installation orientation and color effect on distribution transformers using E-TRM method and its effect on loading

The importance of the distribution network is not overlooked by anyone. The transformer is one of the key equipment in this network. Therefore, great care and attention are needed in its design, maintenance and operation. Most of the oil-immersed distribution transformers are operated under solar radiation conditions. However, increasing the oil temperature due to solar radiation is not considered in their design. This increases the oil temperature above the design temperature value and thus reduces the life of the transformer. In this paper, due to the lack of specified equations for solar energy absorption by the fins and tank of the transformer, a novel method and equation are proposed for the calculation of the transformer solar radiation absorption amount. As well as, the effect of orientation on the corrugated tank distribution transformers oil temperature is investigated using the Electro-Thermal Resistance Model (E-TRM). For this purpose, two identical transformers with different orientations are tested experimentally and the results are compared and verified with the numerical results. The transformer tank color is one of the effective factors of solar radiation absorption. Depending on the absorption and emission rates, the effect of the different colors of the transformer tank on the oil temperature in different loading is investigated in this paper. The results show that the use of bright colors in comparison with dark colors can lower the oil temperature by about 3 °C on the rated loading of the transformer. In order to consider the effect of solar radiation on the transformer, the modified ambient temperature is introduced for the design of the transformer. Finally, the effect of transformer operation under solar radiation and with different colors is investigated and transformer loading de-rating is proposed by a novel equation.

ПРОЦЕССЫ ПЕРЕНОСА В ДИСПЕРСНЫХ СИСТЕМАХ И НАНОСИСТЕМАХ, СОДЕРЖАЩИХ ЧАСТИЦЫ СФЕРИЧЕСКОЙ И ЦИЛИНДРИЧЕСКОЙ ФОРМЫ

There is considered a transfer of electromagnetic emission in the systems of spherical dispersion particles with different optical characteristics. A numerical method for definition of thermal source density for two spherical particles is offered. The method is applicable both for particles with constant optical characteristics, and for particles the dielectric permittivity of which follows Kerr’s Law or depends upon even degrees of the module of an electric vector. A model of electromagnetic emission transfer in cylindrical particles having inclusions of other chemical composition is developed. The substance of the inclusion differs considerably from the material of the particle by a factor of emission absorption for the wave length under consideration in long-wavelength approximation. For the calculation of a temperature field of the spherical particle system in two-dimensional approximation there was used a finite element method. The configurations of the particle location of the system were chosen in a random way; as typical dimensions of the system there were considered longitudinal and transverse diameters of clusters, the distance between the centers of two largest particles and similar natural geometrical properties. A possibility for heat transfer control in such systems is considered. It follows from our model calculations obtained that both electromagnetic and thermal interaction of dispersion articles may be visible at larger distances between their centers; that close to the border of a dispersion particle there is a thermal surface layer of the particle, where temperature distribution bears considerably a heterogeneous character. It is defined that in a poly-dispersion system the impact of group effects can change temperature by one and a half times and more.

Adoção de biotecnologias para revegetação mais eficiente por feijão-de-porco e crotalária em rejeito de minério de ferro

Often unable to regenerate naturally, areas degraded by ore tailings must follow measures aimed at their environmental recovery. The revegetation and the use of bio-stimulants can contribute to the improvement of soil fertility leading to increased production of plant biomass and the cycling of nutrients between soil-plant.The objective was to evaluate the dry matter production, accumulation and nutrient export rates by pig beanplants (Canavalia ensiformis) and Crotalaria juncea cv. IAC-KR-1 as a function of the application of humic substances and diazotrophic bacteria. The experiment was conducted in a greenhouseusing iron ore tailings as substrate. An experimental design of random blocks (4x3x2) was used with four repetitions, four doses of humic substances, applied at 3 different times, with or without inoculation of diazotrophic bacteria. The supply of humic substances and mainly the inoculation in both species increased the dry matter production, reaching 70% of the average increase in pig beans. Inoculation in pig bean plants increased the absorption and transfer factor of Fe and P, and reduced the transfer factor of K, Ca and Mg, and in crotalaria plants increased the absorption of Mg, P and Mn, and reduced the absorption of Fe. The high content of Fe in mining tailings culminated in high absorption and mobilization of this element in the roots of the plants as an alternative to minimize toxic effects caused by its excess.

Induced mathematical filtration as an innovative strategy for discrimination and estimation of glycemic control drugs in fixed dose combination

An innovative strategy was developed for the estimation of a fixed dose combination containing Alogliptin (ALO) and pioglitazone (PIO) using induced concept for resolving the overlapped spectra, lacking isoabsorptive point. This strategy is based on coupling factors as numerical values or ratios as spectrum form with the recorded signals leading to induced mathematical filtration of the drug of interest and complete elimination of the interfering one in the combination without prior physical separation. The calculated factors were factor of equality in induced dual wavelength (IDW) or absorptivity factor in induced concentration subtraction method (ICS) while absorptivity ratio spectrum for induced amplitude modulation method (IAM). The calibration curves displayed linearity within 1.0–16.0 μg/mL for ALO and 2.0–22.0 μg/mL for PIO with good correlation coefficients. The induced methods specificity was also assured through the assaying different synthetic mixtures prepared to contain the two drugs in ratios approaching the ratio actually found in the marketed dosage form. The methods were applicable and suitable for estimating ALO and PIO in both bulk form and their fixed dose combination. Induced methods have been extensively validated in accordance with ICH guidelines and results demonstrated the accuracy and reproducibility in comparison to the reported method.

Calcium-based TLD materials for radiation applications

This study focused on radiation interaction parameters of four compounds of calcium which are the most common types of thermoluminescence dosimetry (TLD). Firstly, the mass attenuation coefficients (MAC, μ/ρ) and effective atomic numbers (Zeff) of calcium based-TLD materials such as CaSO4, CaF2, Ca5F(PO4)3 and CaCO3 were measured in the energy region 121.87–1408.01 keV. The values of MACs and Zeffs of CaSO4, CaF2, Ca5F(PO4)3 and CaCO3 were then theoretically calculated at same photon energies. Good agreements were observed between the experimental and theoretical results for MAC and Zeff values (diff. ≤ 8.17%). In addition, the mass energy absorption coefficients, Kerma relative to soft tissues, equivalent atomic number (Zeq), and buildup factors (energy absorption and exposure buildup factors; EABF, EBF) were theoretically calculated in the energy region 0.08–2 MeV. The results displayed significant changes in equivalent atomic number, such that these values increased with the increasing energy and after 1 MeV it generally decreased. CaCO3 was finally found the best tissue equivalent material because of fact that the values of Kerma and Zeff ratios were nearest to unity (1) among calcium-based TLD materials at the studied energies.

Performance improvement of InP nanowire array solar cells by decorated nanowires and using back reflector

Abstract Geometrical design of the vertical arrays of III-V semiconductor nanowires (NWs) is a good candidate for optoelectronic devices due to their ability to excite nanophotonic resonances in the absorption spectrum. Since the appropriate tailoring of radius, length, and pitch is an effective factor in the light absorption of NWs, we first determine the radius and pitch of NWs in which the light absorption of the array is almost the same for different lattices. Then the length at which the best absorption occurs in the NWs is calculated. The plasmonic effect on the performance of the solar cell array is then investigated by calculating the array properties such as adsorption and short-circuit current density using the finite-difference time-domain (FDTD) numerical model. The plasmonic nanostructure is a composite light-trapping structure in which NWs are decorated with gold nanoparticles and an array of gold hemispheres is placed at the rear of the surface as a back reflector. Various geometric shapes such as spheres, cubes, hemispheres, and disks were used to decorate NW with gold nanoparticles, among them spherical gold nanoparticles were more absorbed than other geometric shapes at higher wavelengths, especially at a wavelength close to the bandgap, where most photons are not trapped. It is observed that this light-trapping structure excites plasmonic modes and improves absorption of NWs. Based on FDTD simulation results, the short-circuit current density and maximum photovoltaic efficiency are respectively improved by 8.56% and 13.33% in the proposed structure compared to the bare structure.

Adoption of energy efficiency measures in the buildings of micro-, small- and medium-sized Portuguese enterprises

This paper seeks to analyse the adoption of Energy Efficiency Measures in non-residential buildings. Based on the concepts of agency theory and absorptive capacity, the propensity of Micro-, Small- and Medium-sized Enterprises in Portugal to adopt energy efficiency in lighting, insulation, and the replacement and operation of heating, was evaluated. To achieve this, an online survey was carried out, and the resultant data was treated using Probit models. The main findings suggest that absorptive capacity factors are a key reason for adopting more efficient and profitable technologies. Policymakers should provide assistance and information to the managers of these enterprises regarding the benefits of energy efficiency measures. Additionally, this paper shows that subsidiary enterprises are more likely to adopt energy efficiency measures. Although subsidiaries suffer pressures due to agency theory factors, they may also benefit from knowledge transfers from their parent enterprises. Most of the decisions and barriers considered by enterprises are not based on audits or the advice of energy management professionals, since more than 65% of the respondents have never performed an energy audit, and over 82% do not have an energy manager.

Dielectric Properties of Water in Saline Soil and its Solonchak Vegetation at a Frequency of 1.41 GHz

Dielectric properties of saline soil (SS) and Salicornia perennans Willd (SPW) were measured at a frequency of 1.41 GHz using a bridge-type laboratory setup and different volume fractions of water in the samples. Experimental dependences of the refractive index and absorption factor on a volume fraction of water were approximated by piecewise-broken lines with break two points corresponding to maximum volume fractions of bound water in the samples. In the SS and SPW, we identified three categories of water with different dielectric properties. Using the empirical dependences refractive index, absorption factor on a volume fraction of water and the refraction model, dielectric parameters of bound and free water from the samples were calculated. Based on the experimental data and model representations, the possibility of using the unified approach to the description of dielectric properties of SS and SPW was discussed. To describe the dependences of the refractive index and absorption factor of SS and SPW volume fraction of water, the refraction model is used.

Preparation of Hot-Melt Extruded Dosage Form for Enhancing Drugs Absorption Based on Computational Simulation.

The aim of this study was to control the dissolution rate and permeability of cilostazol. To enhance the dissolution rate of the active pharmaceutical ingredient (API), hot-melt extrusion (HME) technology was applied to prepare a solid dispersion (SD). To control permeability in the gastrointestinal tract regardless of food intake, the HME process was optimized based on physiologically based pharmacokinetic (PBPK) simulation. The extrudates were produced using a laboratory-scale twin-screw hot-melt extruder with co-rotatory screws and a constant feeding rate. Next, for PBPK simulation, parameter-sensitive analysis (PSA) was conducted to determine the optimization approach direction. As demonstrated by the dissolution test, the solubility of extrudate was enhanced comparing cilostazol alone. Based on the PSA analysis, the surfactant induction was a crucial factor in cilostazol absorption; thus, an extrudate with an even distribution of lipids was produced using hot-melt extrusion technology, for inducing the bile salts in the gastrointestinal tract. In vivo experiments with rats demonstrated that the optimized hot-melt extruded formulation was absorbed more rapidly with lower deviation and regardless of the meal consumed when compared to marketed cilostazol formulations.

Determination of the steady-state kinetics in a spin-1 Ising model using path probability method

As a continuation of our previously published work, we propose a theoretical framework for the determination of steady-state kinetics in a spin-1 Ising model by the path probability method. The framework is based on the principles of non-equilibrium statistical physics and is quite different from the phenomenological approach. We construct a set of linear kinetic equations for the order parameters using the non-linear dynamic (or rate) equations in the presence of external magnetic field. From the steady-state solutions of the linear equations, an expression for the complex (or dynamic) magnetic susceptibility [Formula: see text] is derived. The temperature dependence of the magnetic dispersion relation [Formula: see text] and magnetic absorption factor [Formula: see text] has been studied in the ferromagnetic (FM) and paramagnetic (PM) phases as well as near the critical regime.

Ballistic Impact analysis of 2D woven Kevlar/Basalt reinforced composite

In defence industry, ballistic impact is common scenario occurs often. The materials used for making vests, automobile covering parts, aerospace parts affected due to impact of projectile. These materials should posses’ good impact strength and energy absorption for its damage resistance and providing safety for the industry. Usually Aramid fiber Kevlar used for its well-known impact strength [8]. Fiber alone creates expensive and usage the same under every condition subjected to less velocity impact can be diminished by Weaving Kevlar with Basalt. Thus, it is important to calculate its impact strength and energy absorption factor of reinforced composites. In this thesis, Kevlar is weaved with Basalt for its good resistance to impact and the ballistic impact test is carried out with structural steel projectile for studying its behaviour, impact strength and energy absorption. From the results, it is sufficient to conclude that usage of 2D woven Kevlar Basalt composite behaviour on the basis of woven pattern with impact of projectile.

TiB2 Thin Film Coated Glass and High Speed Steel (HSS) in Applications of Radiation Shielding Technology

TiB2 (titanium diboride) is a transition metal boride with remarkable properties and, its thin-film coatings can be deposited on various substrates to develop the wear resistance properties of substrates. Radiation interaction properties of TiB2 coated glass and HSS are very significant as well for shielding applications and it has not been investigated so far. In this work, linear attenuation coefficient (µ), half-value layer (HVL), tenth-value layer (TVL) and mean free path (MFP) of TiB2 coated glass and HSS (AISI-M2) were measured using a 133Ba radioactive point source at energies 80.8, 276.4, 302.8, 356 and 383.8 keV. A comparison has been made with some radiation shielding concretes with respect to MFP. Energy absorption and exposure buildup factors (EABF and EBF) of composites were also calculated in the experimental energy region 50 – 500 keV. TiB2 coated glass and HSS were found to be better radiation shielding materials than the standard shielding concretes concluding that they can be further developed for radiation shielding applications.

Optical and structural properties of n− and p−InSe/In2O3 heterostructures

In this work crystal structure and surface morphology, photoluminescence and fundamental optical absorption of n− InSe and p−InSe:Cd (0.05 at. %) single crystals and related heterojunctions with native oxide (In2O3) formed by surface oxidation are investigated. Oxidation-induced defects and Cd impurities shield exciton bonds, contribute to the increase of fundamental absorption, and determine photoluminescence features of InSe layer from the n (p)−InSe/In2O3 interface.Doping-induced impurity states and structural defects in the interfacial InSe layer are determining factors for the photon absorption at energies below the band gap.Impurity photoluminescence of interfacial InSe layer originates from donor−acceptor pair recombinations, for inter-pair distance much greater than thickness of elementary Se–In–In–Se packings.The violet−red emission band is determined by nonequilibrium charge carrier recombination in the interfacial In2O3 layer. Its intensity and shape are determined by structural defects at the p−InSe surface.

A detailed investigation of gamma-ray energy absorption and dose buildup factor for soft tissue and tissue equivalents using Monte Carlo simulation

In the present work, the gamma-ray energy absorption buildup factor for water and dose buildup factor for soft tissue (ICRU 4-component), A-150 tissue-equivalent plastic (A150TEP), and tissue equivalent-gas, methane-based (TEGMB) were studied for 356, 662, 1173, and 1332 keV gamma-ray energy up to depths of 10 mean free path (mfp) extensively using Monte Carlo simulation. The aim in this paper is to investigate the gamma buildup factor for soft-tissue equivalent materials and more specifically to study the relative difference between them at practical gamma energies through the Monte Carlo simulation method. The simulations have been performed by MCNPX code, which could be very useful for calculation of shielding estimates. The results revealed that by using the MCNPX code one can easily calculate the energy absorption and dose buildup factors for different materials and also different energies. The simulation results for water were verified by comparing data with those of experimental works wherever possible. In addition, the simulation results for soft tissue were verified by the G-P fitting method, as well. Moreover, the simulation results of the total mass attenuation coefficients of water, A150TEP, soft tissue, and TEGMB were compared with standard database of NIST-XCOM and a good agreement has been obtained. The materials selected have been studied for the first time in this work with respect to the gamma buildup factors at specific energies mentioned above by the Monte Carlo simulation method.

Improving high-pressure water scrubbing through process integration and solvent selection for biogas upgrading

Biogas plays a vital role in many renewable and sustainable energy strategies, where CO2 removal is required to produce biomethane (i.e., biogas upgrading). New ideas and technologies have been proposed to improve the process efficiency of biogas upgrading with liquid absorbents, and ionic liquids have been identified as promising candidates. Meanwhile, there is an urgent need to effectively utilize low-quality waste heat in industry. In this study, two strategies (i.e., waste heat integration and desorption unit modification) were proposed and compared with the original high-pressure water scrubbing; in addition, the effects of the temperatures of the heat source and solvents on the energy usage and cost were further investigated. The results showed that the total cost of the process integrated with waste heat recovery decreased by 6.2% compared with the original high-pressure water scrubbing, and the higher temperature of the waste heat source corresponded to a lower cost. The comparison of different solvents further confirmed that ionic liquid-based solvents were promising, with a potential cost reduction of 24.7%; the properties of the solvent, such as the CO2 absorption capacity, selectivity, and viscosity had significant influences on the total cost, and a new and single index “comparative absorption factor” was proposed to reflect the overall impact of these properties on the cost.

Influence of Soil Properties on Maize and Wheat Nitrogen Status Assessment from Sentinel-2 Data

Soil properties variability is a factor that greatly influences cereals crops production and interacts with a proper assessment of crop nutritional status, which is fundamental to support site-specific management able to guarantee a sustainable crop production. Several management strategies of precision agriculture are now available to adjust the nitrogen (N) input to the actual crop needs. Many of the methods have been developed for proximal sensors, but increasing attention is being given to satellite-based N management systems, many of which rely on the assessment of the N status of crops. In this study, the reliability of the crop nutritional status assessment through the estimation of the nitrogen nutrition index (NNI) from Sentinel-2 (S2) satellite images was examined, focusing of the impact of soil properties variability for crop nitrogen deficiency monitoring. Vegetation indices (VIs) and biophysical variables (BVs), such as the green area index (GAI_S2), leaf chlorophyll content (Cab_S2), and canopy chlorophyll content (CCC_S2), derived from S2 imagery, were used to investigate plant N status and NNI retrieval, in the perspective of its use for guiding site-specific N fertilization. Field experiments were conducted on maize and on durum wheat, manipulating 4 groups of plots, according to soil characteristics identified by a soil map and quantified by soil samples analysis, with different N treatments. Field data collection highlighted different responses of the crops to N rate and soil type in terms of NNI, biomass (W), and nitrogen concentration (Na%). For both crops, plots in one soil class (FOR1) evidenced considerably lower values of BVs and stress conditions with respect to others soil classes even for high N rates. Soil samples analyses showed for FOR1 soil class statistically significant differences for pH, compared to the other soil classes, indicating that this property could be a limiting factor for nutrient absorption, hence crop growth, regardless of the amount of N distributed to the crop. The correlation analysis between measured crop related BVs and satellite-based products (VIs and S2_BVs) shows that it is possible to: (i) directly derive NNI from CCC_S2 (R2 = 0.76) and either normalized difference red edge index (NDRE) for maize (R2 = 0.79) or transformed chlorophyll absorption ratio index (TCARI) for durum wheat (R2 = 0.61); (ii) indirectly estimate NNI as the ratio of plant nitrogen uptake (PNUa) and critical plant nitrogen uptake (PNUc) derived using CCC_S2 (R2 = 0.77) and GAI_S2 (R2 = 0.68), respectively. Results of this study confirm that NNI is a good indicator to monitor plants N status, but also highlights the importance of linking this information to soil properties to support N site-specific fertilization in the precision agriculture framework. These findings contribute to rational agro-practices devoted to avoid N fertilization excesses and consequent environmental losses, bringing out the real limiting factors for optimal crop growth.

Cyclic Response of Steel Fiber Reinforced Normal Strength Concrete Exterior Beam-Column Joint Under Reversed Cyclic Load

Failure investigation studies on a large number of buildings exposed to earthquake loads revealed that Beam-Column Joint (BCJ) is the most critical structural regions in any moment resisting RC structure. The structural response of RC moment resting frame system under the earthquake loads mainly depends on the behavior and performance of the BCJ. It should be designed and detailed properly to ensure safety and serviceability of the structure under various earthquake loads. In the present Experimental work, Normal Strength Concrete (NSC) Fiber Reinforced Beam-Column Joint specimens are cast and are subjected to Cyclic loading. Proportions of steel fibers used are 0%, 0.5% and 1%. Load response curves have been plotted to demonstrate change in the Energy absorption, Stiffness Degradation and Ductility factors.

Analisis Faktor Rendahnya Motivasi Belajar Mahasiswa

This study aims to determine the factors that cause low motivation to learn IAIN Curup students, especially in the fourth semester Islamic Education Study Program. The method used in this paper is a qualitative method, data collected from observations, documentation and interviews with 30 respondents . The results of the study found 3 important parts that affect student interest in learning, namely the preparation and planning of learning by students and lecturers; secondly the evaluation of lecture implementation and thirdly the lecture obstacles experienced by students. There are several factors that cause students to have low motivation to learn, namely: 1) economic factors, which cause a lack of concentration in learning, because they require them to work while in college, 2) alumni absorption factors in low employment, making students doubt the future after becoming undergraduate, 3) the educational background factors of the majority of students from public schools, causing difficulties in attending Islamic-based courses. Conclusions, It needs careful planning in preparing the curriculum, Implementation of the curriculum is really done, Need to increase student motivation, evaluation and assessment of students is really carried out according to existing provisions, Obstacles experienced in each implementation of the task is not something to be avoided but he was demanded to find a solution so that the next process is not hampered.
 Keywords: PAI Learning, STAIN Students, Learning Motivation

Differing photosynthetic responses to excess irradiance in the two coexisting seagrasses, Halophila ovalis and Halophila decipiens: Chloroplast avoidance movement, chlorophyll fluorescence, and leaf optical properties

Seagrasses cope with excess irradiance using a suit of photoprotective mechanisms, however, Halophila species are the only seagrasses known to exhibit chloroplast avoidance movement. Here we examined this phenomenon together with concurrent change in photosynthetic and leaf optical properties in H. ovalis and H. decipiens. Although co-existing, these two seagrasses displayed different light use characteristics derived from rapid light curves; H. ovalis and H. decipiens showed features of sun- and shade-adapted plants, respectively. Experimentally the seagrass leaves were exposed to low, medium, and high irradiance (80, 200 and 800 μmol photons m−2 s−1, respectively) for 60 min, followed by 60 min in darkness. Chloroplast movement occurred in H. ovalis exposed to medium or high irradiance and in H. decipiens exposed to low or medium irradiance. Chloroplast gathering was observed after 20 min of exposure and chloroplast dispersal was observed after 20 min in darkness, dependent on treatment and species. Increasing irradiance lowered the effective quantum yield and increased the non-photochemical quenching (NPQ). Despite stronger up-regulation in NPQ, photoinhibition was detected in H. decipiens. The absorption factor and the Soil-Plant Analysis Development value were modulated by chloroplast movement rather than a change in chlorophyll content, except for H. decipiens exposed to high irradiance where photodamage of chlorophylls may have occurred. Chloroplast movement in both seagrasses was inhibited by 3-(3,4-dichlorophenyl)-1,1-dimethylurea, indicating regulation by photosynthesis. Our results suggest that H. ovalis has a higher tolerance to excess irradiance than H. decipiens and that this is assisted partly by chloroplast avoidance movement.