Distribution In Components Research Articles

Ecogeochemistry of Mercury in Aquatic Organisms and their Habitat on the Territory of Moscow

The issue of technogenic mercury pollution of aquatic ecosystems in urban areas of Moscow was considered based on the sampling data of aquatic plants, amphibians and bottom sediments of the water bodies under study. Quantitative assessments of the mercury distribution in wild life and inorganic nature components of 33 water bodies of Moscow in both protected areas and beyond. Information was provided on the average percentage of mercury in some components of freshwater ecosystems. An excess of the average ecotoxicant concentration values in the in duckweed family (24 ng/g dry wt), amphibians (177 ng/g dry wt) and bottom sediments (57 ng/g dry wt) in the territory of Moscow was revealed versus bulk earth and background values. A significant correlation of mercury concentration for the natural components under study (R>0.4) was identified.

Rossby Waves in Total Ozone over the Arctic in 2000–2021

The purpose of this work is to study Rossby wave parameters in total ozone over the Arctic in 2000–2021. We consider the averages in the January–March period, when stratospheric trace gases (including ozone) in sudden stratospheric warming events are strongly disturbed by planetary waves. To characterize the wave parameters, we analyzed ozone data at the latitudes of 50°N (the sub-vortex area), 60°N (the polar vortex edge) and 70°N (inner region of the polar vortex). Total ozone column (TOC) measurements over a 22-year time interval were used from the Total Ozone Mapping Spectrometer/Earth Probe and Ozone Mapping Instrument/Aura satellite observations. The TOC zonal distribution and variations in the Fourier spectral components with zonal wave numbers m = 1–5 are presented. The daily and interannual variations in TOC, amplitudes and phases of the spectral wave components, as well as linear trends in the amplitudes of the dominant quasi-stationary wave 1 (QSW1), are discussed. The positive TOC peaks inside the vortex in 2010 and 2018 alternate with negative ones in 2011 and 2020. The extremely low TOC at 70°N in 2020 corresponds to severe depletion of stratospheric ozone over the Arctic in strong vortex conditions due to anomalously low planetary wave activity and a high positive phase of the Arctic Oscillation. Interannual TOC variations in the sub-vortex region at 50°N are accompanied by a negative trend of −4.8 Dobson Units per decade in the QSW1 amplitude, statistically significant at 90% confidence level, while the trend is statistically insignificant in the vortex edge region and inside the vortex due to the increased variability in TOC and QSW1. The processes associated with quasi-circumpolar migration and quasi-stationary oscillation of the wave-1 phase depending on the polar vortex strength in 2020 and 2021 are discussed.

The aluminum distribution and translocation in two citrus species differing in aluminum tolerance

BackgroundMany citrus orchards of south China suffer from soil acidification, which induces aluminum (Al) toxicity. The Al-immobilization in vivo is crucial for Al detoxification. However, the distribution and translocation of excess Al in citrus species are not well understood.ResultsThe seedlings of ‘Xuegan’ [Citrus sinensis (L.) Osbeck] and ‘Shatianyou’ [Citrus grandis (L.) Osbeck], that differ in Al tolerance, were hydroponically treated with a nutrient solution (Control) or supplemented by 1.0 mM Al3+ (Al toxicity) for 21 days after three months of pre-culture. The Al distribution at the tissue level of citrus species followed the order: lateral roots > primary roots > leaves > stems. The concentration of Al extracted from the cell wall (CW) of lateral roots was found to be about 8 to 10 times higher than in the lateral roots under Al toxicity, suggesting that the CW was the primary Al-binding site at the subcellular level. Furthermore, the Al distribution in CW components of the lateral roots showed that pectin had the highest affinity for binding Al. The relative expression level of genes directly relevant to Al transport indicated a dominant role of Cs6g03670.1 and Cg1g021320.1 in the Al distribution of two citrus species. Compared to C. grandis, C. sinensis had a significantly higher Al concentration on the CW of lateral roots, whereas remarkably lower Al levels in the leaves and stems. Furthermore, Al translocation revealed by the absorption kinetics of the CW demonstrated that C. sinensis had a higher Al retention and stronger Al affinity on the root CW than C. grandis. According to the FTIR (Fourier transform infrared spectroscopy) analysis, the Al distribution and translocation might be affected by a modification in the structure and components of the citrus lateral root CW.ConclusionsA higher Al-retention, mainly attributable to pectin of the root CW, and a lower Al translocation efficiency from roots to shoots contributed to a higher Al tolerance of C. sinensis than C. grandis. The aluminum distribution and translocation of two citrus species differing in aluminum tolerance were associated with the transcriptional regulation of genes related to Al transport and the structural modification of root CW.

ANALYTICAL STUDY OF HYDRAULIC PRESSURE CAUSED BY LIQUID IN GATE VALVES

There is an urgent need worldwide for efficient fluid control equipment. Some of the existing equipment has certain limitations for efficient fluid control under high pressure conditions. Thus, design modifications are required to solve this problem. This article presented a analytical method for designing and performing stress analysis for a high pressure valve used on a typical oil and gas wellhead with operating pressures up to 100 MPa. The most important components of a valve are the body and the valve (disc). The conversion design uses analytical method calculations to determine the stress and strain distribution in the critical components of a high pressure valve. Results from both analytical computational design and finite element analysis indicate reasonable agreement by measuring percent performance variance. Thus, the results of this research work confirm the reliability of the designed valves in accordance with engineering design estimates and, in turn, can be optimally improved in the manufacture of high pressure valves. Keywords: gate valve, analytical method, validation, design and high pressure.

Nutrient accumulation and distribution in different bamboo species under semi-arid climatic condition of Entisol

A long-term field experiment initiated in the year 2018-19 at National Agricultural Research Project, was selected for conduct of present investigation during the year 2020-21 in order to determine the effect of different bamboo species on nutrient accumulation and distribution in different biomass components as a result of bamboo plantation grown on Entisol under semiarid climatic condition. In the average effect of bamboo biomass components, the nitrogen concentration was found highest in bamboo leaves (1.51% N), phosphorus and potassium concentration was significantly highest in bamboo branches (0.095% P and 0.64% K respectively), while, carbon concentration was numerically highest in bamboo stem (43.53% C). The bamboo species treatment, Bambusa nutans recorded significantly highest nitrogen uptake (457.83 kg ha-1), whereas Bambusa tulda recorded the highest phosphorus and potassium uptake (49.70 and 409.77 kg ha-1, respectively). The maximum carbon uptake of 27.83 t C ha-1 was recorded in Bambusa nutans. All of the tested bamboo species had shown greater amounts of nutrient accumulation in above ground biomass, i.e. Stem > Branches > Leaves > Leaf-litter > Rhizome > Roots, due to maximum partitioning of total biomass towards above ground components. The results indicate that the relative proportions of nutrients accumulated in different biomass components in tested bamboo species vary greatly due to variations in elemental concentrations and biomass output after 2nd year of bamboo plantation under semi-arid climatic conditions of Entisol.

The effect of bush material property on the metal-polymer contact stress in knee megaprosthesis – An in silico study

The long bone loss management using segmental resection for the fixation between femur and tibia is called modular megaprostheses. Despite the huge development of design and materials of biomedical implants, the design issue of megaprostheses are still highly challenging. The wear and formation of wear debris of the polymer bush in the megaprosthesis is one of the significant problems faced. The objective of the study is to compare between PEEK, UHMWPE and their composites as the bush material and to find their suitability in order to reduce the polymer-metal contact stress. A three- dimensional model of the bone assembly is extracted from the Computerized Tomography (CT) scan for both femur and tibia using image processing software, Mimics. A 3D model of custom-made knee prosthesis is also developed. Both the 3D models were assembled and analyzed by giving boundary conditions with reference to the clinical conditions. The finite element analysis employed on the assembled prosthesis clearly shows the stress distribution and deformation in different parts and components of the megaprosthesis as well as adjacent femur and tibia. It is seen that the stress generated in the polymer-metal interfaces, which is one of the chief reasons behind the bush wear, could be varied by using varied bush materials.

A detailed study of the transient behavior of dual-skin chest-freezer with R290

• Detailed transient behavior of dual-skin chest-freezer operating with R290 is described. • Two mathematical models for freezer transient simulation are developed. • Experimental results of transient system operation are provided in Excel file. • Thermal load influence is simulated with a maximum relative error of 2.7%. • The optimum refrigerant charge of 200g of R290 is calculated. This work reports on a numerical and experimental study of the transient behavior of a dual-skin chest-freezer refrigeration system, operating with R290. A simpler dynamic mathematical model, called thermal, and a more sophisticated one, called capacitive, which models the mass distribution in the systems components, were evaluated. The experiments provided measured data for the characterization of the transient operation of the appliance, supply of models’ input data, and validation of the models. Comparisons between simulation and experimental results showed a very good agreement for both transient and time-averaged systems behavior and performance. The maximum relative error for temperatures at pull-down and on/off operations was 5.5 % . The capacitive model simulated the transient experimental behavior of the refrigeration system well when goods were inserted in the freezer’s cabinet, showing a 2.7 % maximum relative error for the systems performance parameters. Moreover, it yielded a parametric analysis of the refrigerant charge, determining a 200g mass of R290 for the optimum performance. The thermal model is an excellent feature for a first design, simulating 100 min of a real operation in few seconds. The capacitive model provides more complex results, and is a very good tool for a detailed systems design. The experimental data can be used by other researchers for validating their simulations and experimental studies. The paper provides new findings for a system operating with R290, a fluid that has been widely used in small scale refrigeration systems for household applications.

Validation of the simplified heat conduction model of EN ISO 52016-1

The issue of improving the building energy efficiency led to the development of calculation methods for the building energy performance assessment. To overcome the low accessibility to detailed input data, the recently introduced EN ISO 52016-1 hourly method is based on assumptions and simplifications chosen to allow a sufficient accuracy in the outcomes with a low amount of input data. Among these assumptions, a simplified mass distribution in the envelope components is considered. In the present work, the hypothesis of the simplified heat conduction model introduced by the EN ISO 52016-1 technical standard and an improved solution provided by its Italian National Annex were evaluated. In particular, the accuracy in the prediction of the internal surface temperature was assessed in comparison with a detailed finite difference conduction algorithm. The validation was performed for 5 opaque component test cases, covering a wide range of areal heat capacity values, by considering both internal and external thermal constraints (e.g. variation of the air temperature). For the structures and boundary conditions considered, results reveal that the standard algorithm allows to predict the internal surface temperatures with a valuable level of accuracy compared to the finite difference algorithm.

Evaluation of neutron flux distribution in structural components and activation products in aluminum alloy at 13-2 channel of the DNRR

The estimation of radiological properties of activated structural components of a nuclear reactor due to irradiation of neutron produced by fission is a very important task for radiation safety and reasonable cost of dismantling and radioactive waste management in the decommissioning plan of the reactor. In this work, the calculation approach was carried out by using three-dimensional neutron transport model with the Monte Carlo code MCNP5 to evaluate neutron fluxes and reaction rates. The Bateman equation was solved with neutron absorption reactions (fission and capture) and disintegration by ORIGEN2 code to obtain the activity of materials in reactor structures. This paper presents the evaluation results of the neutron flux distribution and the radioactivity of long-lived key activation products such as 60Co, 55Fe, 59Ni, 63Ni, etc. isotopes in the structural components of the Dalat Nuclear Research Reactor (DNRR). The validation of calculation methodology of the two codes was implemented by comparing calculation results with measured neutron fluxes at irradiation positions in the reactor core as well as specific activities at the bottom part of the aluminum guiding tube at 13-2 channel, which has been removed from the reactor core about six years. The calculation results were in good agreement under 7% difference with the experimental neutron flux value of (6.05±0.52) × 1012 n/cm2.s, and under 33% difference with the experimental specific activities of 60Co isotope being 1.86×104, 9.99×104, and 1.28×105 Bq/g at the positions of -32.5, -17.5 and -2.1 cm (the centerline of the reactor core is at 0 cm), respectively, in the aluminum guiding tube of irradiation channel 13-2. The neutron flux distributions in other structural components such as the graphite reflector, thermal column, thermalizing column, concrete shielding, etc. of the reactor were also evaluated. The obtained calculation results and experimental data are very valuable for the development of a suitable decommissioning plan and a reasonable dismantling strategy for the DNRR.

Performance-based seismic design methodology for tall buildings with outrigger and ladder systems

The plethora of efforts needed for conducting the Performance-Based Seismic Design (PBSD) to investigate the tall buildings' performance requires sustainability in developing this approach and facilitating its implementation to obtain an effective final design. To tackle this issue, novel performance-based design procedures are proposed in this study. The novel PBSD procedures commence with integrating the optimization and simplification techniques into the preliminary design stage to rapidly obtain an optimal initial amount of materials required to establish outrigger and ladder systems models. Then, conducting a nonlinear time history analysis with the aid of ETABS and Peforme-3D software to scrutinize the extent to which the initial design approaches the final design and the superiority of each system under frequent or rare earthquake events. The global and component responses are examined for each system under three performance levels: immediate occupancy IO, life safety LS, and collapse prevention CP. The optimization and simplification techniques in the preliminary design stage have reduced the overwhelming efforts required to generate and prepare an optimized preliminary design for both systems. Furthermore, the results of the nonlinear time history analysis found that the ladder system reduced the structure's global response by 27.2% for the lateral displacement and 30.4% for the base shear than the outrigger system. However, the evaluation of the components acceptance criteria confirmed that the ladder system increased the plastic damage distribution in the external structural system's components and reduced it in the internal one. Generally, the preliminary design approached the final design by varied ratios, 60–80% in the ladder system and 60–95% in the outrigger system for different components. Therefore, it is recommended to apply this approach to the outrigger system and improve the ladder system's efficiency. Finally, this study is limited to an optimized preliminary design that approaches the final design and reduces the iteration number of the PBSD procedures. Thus further researches are required to improve and extend the applicably of these procedures.

Investigating Carbonate Distribution in Particle Size Components of Some Soils of Khuzestan Province

Investigating Carbonate Distribution in Particle Size Components of Some Soils of Khuzestan Province

Analytical Evaluation of Strengthening, Local Internal Stresses and Microderformations in Welded Joint Metal during Wet Underwater Welding

Analysis of structural factor influence on local internal stresses and zones of deformation localization in upper and lower bainite structures in welded joints of low-alloy steel at wet underwater welding was performed. It is established that when welding joints under the water and applying an external electromagnetic field in the metal of the heat-affected zone (HAZ), a finer-grained substructure is formed with a general decrease in the dislocations density and with their uniform distribution. Estimates of the local internal stresses level considering the dislocation density distribution in the structural zones of their localization show that their maximum level is formed in the metal of the HAZ overheating region at welding without the external electromagnetic field along the upper bainite laths boundaries. The upper bainite structure is characterized by forming localized deformation zones, where the most significant dislocation density gradients are observed. This can lower the crack resistance of welded joints. Low values of local internal stresses are characteristic of welded joints obtained in the modes applying an external electromagnetic field. This is facilitated by the overall decrease in the dislocation density and their uniform distribution in the lower bainite structural components, which provides high crack resistance of welded joints.

Pressure Prediction by Programme Logic Control Approach on Superplastic Forming in 7075 Al Alloy

A widespread problem in a superplastic forming process is to obtain a uniform thickness distribution in multiple geometry components. Hence, nowadays, the variable pressure control approach has been implementing in order to obtain uniform thickness variation in complex profiles. This paper observed the outcome of various stages in the superplastic forming process for multistage hemispherical die cavity in a newly developed pressure prediction method. Superplastic behaviour such as forming pressure, forming temperature, forming time and thickness distribution are analysed and optimised all parameters in multi-stage profile by using a new pressure prediction approach. Experimentally and numerically evaluated the superplastic parameters and the values are obtained from finite element methods agrees well with the experimental results.

Ginsenoside distribution in different architectural components of Panax notoginseng inflorescence and infructescence

The roots of Panax notoginseng (Burk) F. H. Chen are used as a highly valuable Chinese herbal medicine in the prevention and treatment of cardiovascular and hematological diseases. Several aerial parts of plant are usually abandoned as the wastes. Panax notoginseng inflorescence (IFO) is commonly used as a folk medicine and dietary ingredient, its fruiting stage is referred as infructescence (IFU). Owing to high chemical complexity and structural similarity of ginsenosides, the co-eluting phenomenon, especially for the isomers, is inevitable in the chromatogram, resulting in the inaccurate quantitation. A novel LCMS method using hybrid positive full scan and multiple reaction monitoring (MRM) modes was developed to characterize ginsenoside distribution in different architectural components of IFO and IFU. MRM was performed for the quantification of G-Ra2 and NG-Fp2, a pair of co-eluting isomers with identical negative MS and MS/MS characteristics, and full scan was conducted to quantify other investigated saponins. Our data indicate that flower buds have the highest abundance of the summed saponins, fruit pedicel and fruit pericarp, commonly considered as the useless by-products of seed processing, contain the abundant saponins. Additionally, the contents of the detected ginsenosides in these architectural components significantly increased along with their growth years. Our findings will facilitate comprehensive utilization and exploitation of P. notoginseng inflorescence and infructescence.

Geochemical Fractions of Heavy Metals in Bottom Sediments of the Pobeda Hydrothermal Cluster in the Mid-Atlantic Ridge (17°07′–17°08′ N)

In this study, to better understand the influence of hydrothermal processes on ore metal accumulation in bottom sediments, we examined distribution of Fe, Mn, Cu, Zn, As, and Pb in core of metalliferous sediments from the Pobeda hydrothermal cluster, and in core of non-mineralized (background) carbonate sediments (located 69 km northwards). Mechanisms of Fe, Mn, Cu, and Zn accumulation in sediments (12 samples) were evaluated based on sequential extraction of geochemical fractions, including a conditional mobile (F-1, exchangeable complex; F-2, authigenic Fe-Mn oxyhydroxides and associated metals; F-3, metals bound to organic matter/sulfides), and residual (F-4), fixed in crystalline lattices ones. The element contents were determined by the XRF and AAS methods, total carbon (TC) and total organic carbon (TOC) were determined using a Shimadzu TOC-L-CPN. Mineral composition and maps of element distribution in sediment components were obtained using the XRD and SEM-micro-X-ray spectrometry methods, respectively. In metalliferous sediments, according to our data, the major Fe mineral phase was goethite FeOOH (37–44% on a carbonate-free basis, cfb). In the metalliferous core, average contents (cfb), of Fe and Mn were 32.1% and 0.29%, whereas those of Cu, Zn, Pb, and As, were 0.74%, 0.27%, 0.03%, and 0.02%, respectively. Metalliferous sediments are enriched in Fe, Cu, Zn, Pb, and As, relatively to background ones. The exception was Mn, for which no increased accumulation in metalliferous core was recorded. Essential mass of Fe (up to 70% of total content) was represented by the residual fraction composed of crystallized goethite, aluminosilicates, the minerals derived from bedrock destruction processes mineral debris. Among geochemically mobile fractions, to 80% Fe of the (F-1 + F-2 + F-3) sum was determined in the form of F-2, authigenic oxyhydroxides. The same fraction was a predominant host for Mn in both metalliferous and background sediments (to 85%). With these Fe and Mn fractions, a major portion of Cu, Zn, and Pb was associated, while a less their amount was found in sulfide/organic fraction. In the metalliferous sediment core, maximal concentrations of metals and their geochemically mobile fractions were recorded in the deeper core sediment layers, an observation that might be attributed to influence of hydrothermal diffused fluids. Our data suggested that ore metals are mostly accumulated in sediment cores in their contact zone with the underlying serpentinized peridotites.

Signal-based analysis of the dynamic behaviour of the system in inertia friction welding and its impact on part contact evolution

Inertia friction welding (IFW) is a process used to create joints with high geometrical accuracy and near net shape form. To cope with the complex phenomena occurring during welding, the majority of available studies have analysed the interaction of the workpieces to be joined under simplified conditions, in which the influence of machine assembly tolerances, spindle dynamics and system compliance have been neglected. Among the dimensional properties, the headstock-tailstock concentricity is particularly important to assess the conformity of the weld, for this reason, a novel approach was developed to investigate the physical causes behind the evolution of the radial misalignment between the two workpieces, conventionally referred to as radial runout. First an inverse approach to evaluate the equivalent pressure distribution at the weld interface and the equivalent process loads was implemented starting from the experimental data of radial runout, headstock angular speed and strain extracted with a custom monitoring system during a set of steel welds. The results showed a large variability of the pressure distribution in circumferential direction and non-axisymmetric load components in particular during the conditioning and burnoff phases. Then, the equivalent process loads were used as an input for a Timoshenko beam dynamic representation of the spindle. A good agreement between the model and the experimental data was observed with an average relative error in the radial runout of 0.085. From these results, it was possible to conclude that the lack of axisymmetry in the load components has to be attributed mainly to the misalignment between two workpieces, while the irregular runout to compliance of the system to the non-ideal process loads.

Spatial distribution and long-term changes in water balance components in Croatia

Drought causes great damage to the economy and agriculture in Croatia. Therefore, it is important to gain a better insight into the spatial distribution of water balance components (precipitation (P), potential evapotranspiration (PET), actual evapotranspiration (ET), soil moisture content (S), runoff (RO), recharge (R), and soil moisture loss (L)) and their long-term changes in Croatia. Since measurements of the mentioned components in Croatia are very rare, the Palmer model has been applied to estimate them. The meteorological data from 82 stations have been used in the period 1981–2010. To determine the climate variations long-term trends in water balance components have been analyzed in the period 1901–2017. The PET and ET linear trends in the last decades show a faster growth than in the long-term trends, and the increase in PET (50–80 mm/decade) is significant in most of Croatia, except in the eastern part (27 mm/decade). The results of the mean annual PET and ET spatial distribution revealed that the maximum PET is estimated in the mid-Adriatic area of about 1500 mm, but the lack of precipitation caused the ET (about 700 mm) to be insignificantly different from the values in other parts of Croatia. The analyzed meteorological data from the period 1981–2010 indicated a higher air temperature and lower precipitation amount than in the reference climatic period of 1961–1990. This reduces the ET in areas with insufficient precipitation, i.e., on the Adriatic coast and in the eastern part of Croatia, where an increasing soil moisture deficit during the vegetation period can have a potentially negative effect on agricultural production.

The Low-Temperature Adsorption Characteristics of Activated Carbon With 3He and 4He as Sorption Cooler Cryogens

Abstract As a commonly used sub-Kelvin refrigeration technology, helium sorption coolers play an important role in space and ground applications. The adsorption characteristics of the porous material inside the sorption cooler at low temperature have a crucial influence on its performance. At present, the analysis and calculation of sorption coolers are mainly based on helium 4 (4He) as the working gas, and there is a lack of systematic research on the low-temperature adsorption characteristics of helium-3 (3He) and its coupling effect characteristics of temperature, pressure, and mass distribution in different components. In this paper, a molecular model of activated carbon that is similar to the actual structure was constructed, and the adsorption isobars and isosteric heat of 3He and 4He at 0.8–5 K were comparatively studied based on the grand canonical Monte Carlo (GCMC) method. Besides, the influence of adsorption characteristics of 3He and 4He on the condensation efficiency, the mass distribution after condensation equilibrium, and the self-cooling loss of the sorption cooler were analyzed. The results show that for the 3He sorption cooler, the main factor affecting the condensation efficiency is the adsorbed helium in the sorption pump, while for the 4He sorption cooler, it is the adsorbed helium and the gas in the dead volume. For both 3He and 4He sorption coolers, the condensation efficiency increases as the sorption pump temperature increases or the heat sink temperature decreases, while the self-cooling loss decreases as the heat sink temperature decreases or the operating temperature increases.

Features of Heavy Metals Distribution in Environmental Components of Urban Park Landscapes of Kyiv City

We investigated the impact of the urban environment on the park ecosystems in Kyiv. As representatives of vegetation the species Taraxacum officinale Wigg. and Tilia cordata Mill., were chosen. The content of heavy metals (Cu, Pb, Zn, Ni, Mn, Cr, and Cd) in soil and leaf samples within the ecosystems of the parks Feofaniya, Kyiv Polytechnic Institute, Mariyinsky, Pushkin, and Nyvky was measured. The highest level of soil contamination with heavy metals was found in the areas of parks located near highways and public transport stops. The most polluted park was the Kyiv Polytechnic Park, and the least polluted Feofaniya Park. High levels of metals found in soil samples did not always coincide with their highest levels in the biomass of the studied plants leaves. We found that, according to the phytotoxicological classification of metals by the biological absorption coefficient (BAC) by plants within the studied park ecosystems, Cu, Pb, Zn, Ni, Mn, and Cr belong mainly to the elements of low absorption (hazard class IV) except for Mariyinsky Park, where Zn according to the BAC value belongs to the elements of moderate absorption (hazard class III). The order of amount of metal bioaccumulation in plants obtained by us show a fairly wide range for different park ecosystems, which confirms the principle of ecological congruence (compliance), according to which the living components of an ecosystem have developed appropriate adaptations coordinated by the abiotic environment. In order to identify additional ways of migration of heavy metals to the ecosystem of Feofaniya Park, hydrochemical data from the surface of the first aquifer, circulated within the study area, were involved. It has been suggested that the increased concentrations of Cu, Pb, Zn, Ni, and Mn in the soils of Feofaniya Park are connected with the Pirogivsky landfill, and the groundwater discharged into the park ponds serves as the main way of migration of pollutants to the natural environment, in particular to the soil-plant system. Our results confirm the need to involve biogeochemical data for ecological assessment of the urban environment and early diagnosis of negative influence, when the plants have not yet manifested morphological and anatomical abnormalities.

Evaluation methods for residual stress measurement in large components

Residual stresses play a pivotal role in determining the durability and service life of the component. Processes such as heating, machining, mechanical treatment and even the manufacturing process itself, develop the residual stresses in a component. These initial residual stresses rejig themselves depending on different loading conditions such as rotation, mechanical or thermal loadings. Furthermore, having categorical knowledge about the residual stress field across the whole component is imperative in comprehending how residual stresses impact failure. So, it is vital to determine the stress distribution throughout the component to mitigate the catastrophic failure. This is easy to obtain in case of smaller components due to their small cross-sections, but the same becomes daunting when it comes to large components because of greater depths at which these stresses reside and also of their large cross-sections. Though there are several techniques to measure the residual stresses in large components but work only up to certain depths which restricts there use to specific part dimensions which in turn necessitate to decide the best method for determining the complete stress distribution in large components. Thus, this review aims to elucidate and classify various residual stress measurement methods on the basis of their operating range, principle and technical feasibility with manufacturing process used to manufacture the large engineering components.