Phase Analysis Research Articles

DFT Study of Nanotubes as the Drug Delivery Vehicles for an Anticancer Drug

Abstract: Chemicals and poisons in the body interfere with the cell cycle and inhibit the growth of cancer cells. In this way, the function of chemicals in the body is controlled by taking anti-cancer drugs. Due to the degradability and compatibility of carbon nanotubes and boron nitride with the environment, they can act as suitable drug carriers for the transfer of anticancer drugs and deliver the drugs to the target cells. In the current work, the encapsulation of Formestane (FMS) anticancer drug into the carbon (CNT) and boron nitride (BNNT) (8,8) nanotubes was investigated for the first time using the density functional theory: B3LYP/3-21G* and the natural bond orbital analysis in the gas phase. Using natural bond orbital analysis, the charge transfer between FMS drug and CNT and BNNT nanotubes (8,8)/ FMS (BNNT/FMS) complexes were explored. Based on the results obtained from the calculation of encapsulation energy, it was found that the adsorption process was favorable. The interaction effects of FMS drug and CNT and BNNT (8,8) nanotubes on the natural bond orbital charge, the chemical shift parameters, and electronic properties were also evaluated. This study revealed that CNT and BNNT (8,8) nanotubes can be a suitable carrier for FMS drug delivery. The ultraviolet-visible spectra of the FMS drug, the CNT and BNNT (8,8), and the BNNT/FMS complexes were computed using time-dependent density functional theory (DFT: B3LYP) calculations.

The Estimation of the Stress State of the Iron Alloy Strip Material by the Barkhausen Noise Method

This paper presents the effect of the complex strain state resulting from the asymmetric rolling of TRB products on the changes and distribution of the stress state in the material. The evaluation of the stress state in the material was based on measurements of the magnetoelastic parameter (MP) using the Barkhausen magnetic noise method. The key characteristics of the material under study that enabled the use of changes in the MP parameter to assess the stress state were ferromagnetism and a lack of texture. The first of these enabled the detection of the magnetic signals produced when a magnetic field is applied to the material, causing magnetic domains to align and sudden changes in magnetization. On the other hand, the absence of texture in the material precluded the occurrence of magnetocrystalline anisotropy, which could disturb the results of measurements of the magnetoelastic parameter in the material. In order to determine these features in the material under study, its chemical composition was determined, and a phase analysis was carried out using the X-ray diffraction method. The results of these tests showed the possibility of determining the stress state of the material by means of changes in the values of the MP parameter. On this basis, it was shown that in the TRB strips studied, there is a complex state of stress, the values of which and the nature of the changes depending on the direction of the measurements carried out, as well as on the amount of rolling reduction in the studied area of the strip.

Integrative analysis of genetics, epigenetics and RNA expression data reveal three susceptibility loci for smoking behavior in Chinese Han population.

Despite numerous studies demonstrate that genetics and epigenetics factors play important roles on smoking behavior, our understanding of their functional relevance and coordinated regulation remains largely unknown. Here we present a multiomics study on smoking behavior for Chinese smoker population with the goal of not only identifying smoking-associated functional variants but also deciphering the pathogenesis and mechanism underlying smoking behavior in this under-studied ethnic population. After whole-genome sequencing analysis of 1329 Chinese Han male samples in discovery phase and OpenArray analysis of 3744 samples in replication phase, we discovered that three novel variants located near FOXP1 (rs7635815), and between DGCR6 and PRODH (rs796774020), and in ARVCF (rs148582811) were significantly associated with smoking behavior. Subsequently cis-mQTL and cis-eQTL analysis indicated that these variants correlated significantly with the differential methylation regions (DMRs) or differential expressed genes (DEGs) located in the regions where these variants present. Finally, our in silico multiomics analysis revealed several hub genes, like DRD2, PTPRD, FOXP1, COMT, CTNNAP2, to be synergistic regulated each other in the etiology of smoking.

Transboundary migration of Loxostege sticticalis (Lepidoptera: Crambidae) among China, Russia and Mongolia.

The beet webworm, Loxostege sticticalis, a worldwide pest of many crops, performs a seasonal migration, causing periodic outbreaks in Asia, Europe and North America. Although long-distance migration is well documented in China, patterns of transboundary migration among China, Russia and Mongolia are largely unknown. We performed a phase analysis of L. sticticalis periodic outbreaks among three countries based on 30 years of historical population data, analyzed the wind systems during migration over boundary regions, and traced the migratory routes in a case study of outbreaks in 2008 by trajectory simulation. Highly synchronized outbreak years of L. sticticalis were observed between China and Mongolia, China and eastern Siberia, China and western Siberia, Mongolia and eastern Siberia, eastern Siberia and western Siberia from 1978 to 2008, indicating possible transboundary migration between these regions. Winds at 300-600 m altitude, where adult migration usually occurs, also showed a high probability of northwestern winds in Haila'er (China), Chita (Russia) and Choybalsan (Mongolia), favoring successful adult migration from these areas to northern and northeastern China. Back trajectory analysis further showed that the first-generation adults that caused the severe outbreak of second-generation larvae in 2008 originated from eastern Siberia, eastern Mongolia, and the boundary regions of China-Russia and China-Mongolia. Our findings demonstrated that the source of L. sticticalis outbreaks in northern China was closely related to the outbreaks in Siberia and Mongolia via long-distance transboundary windborne migration. This information will help guide international monitoring and management strategies against this notorious pest. © 2024 Society of Chemical Industry.

Effect of SS-316L and nickel-based interface powders on joint characteristics of microwave welded SS-316L plates

Microwave energy has been exploited as a rapid and volumetric heating source in various manufacturing applications, such as microwave joining. This study used stainless steel (SS-316L) plates to be microwave-joined at 2.45 GHz. The microwave hybrid heating (MHH) technique was used to prepare joints inside a microwave applicator using nickel-based (EWAC 1004EN) and SS-316L interfacing powders at 900 W. Microstructural and mechanical characterizations of the developed joints were performed to understand the effect of the interface powder on weld quality. Microstructural observations revealed adequate metallurgical bonding between interfacing powders and bulk metal with columnar and dendritic grains (EWAC-based joint) and equiaxed grains (SS-316L-based joint). The phase analysis revealed the presence of intermetallic phases such as iron-nickel, chromium carbide, and chromium iron carbide in EWAC-based joint and iron-nickel, nickel-chromium, and chromium carbide in SS-316L-based joint, which contribute to enhanced joint microhardness compared to base alloys. A larger grain size, more low-angle boundaries, and higher misorientation angles were found in the EWAC-based joint. Furthermore, the average ultimate tensile strength of SS-316L-based joints was 26% higher, with a 6.9% enhanced elongation, than that of EWAC-based joints. The EWAC-based joint exhibited better corrosion resistance than that of SS-316L-based joint.

Global insights into seed dispersal mutualism with cooperative efforts and environmental variability

Seed dispersal mutualisms assume a crucial role in sustaining overall ecosystem functionality. This study extends the foundational framework of seed dispersal mutualism by incorporating animal cooperation and environmental variability. Through the integration of stability theory and phase analysis, we investigate the global dynamics of seed dispersal mutualism in deterministic environments. Theoretical findings reveal that the deterministic system exclusively exhibits equilibrium dynamics, ruling out periodic solutions and chaotic phenomena. Notably, in cases of multiple coexisting equilibria, adjacent equilibria display distinct stability properties. Furthermore, employing stochastic analysis and Lyapunov exponents, we ascertain the uniqueness of global positive solutions in the stochastic model, along with stochastic ultimate boundedness, and precise thresholds for the stochastic persistence and extinction. These results illuminate the theoretical mechanisms governing transitions in seed dispersal mutualism across various stable population levels and underscore the insights into how essential biological factors, including animal cooperation efforts and environmental variability, impact the long-term dynamics of seed dispersal mutualism.

Synergistic Improvement of Antibacterial and Osteogenic Differentiation of Thermomechanically Processed Mg-Zr-Sr-Ce Alloy: Insights into the Role of Precipitate Evolution Supported by AIMD Simulation Study.

In the present study, we have discussed the influence of forging temperature (623 K (FT623), 723 K (FT723) and 823 K (FT823)) on microstructure and texture evolution and its implication on mechanical behavior, in vitro-in vivo biocorrosion, antibacterial response, and cytocompatibility of microalloyed Mg-Zr-Sr-Ce alloy. Phase analysis, SEM, and TEM characterization confirm the presence of Mg12Ce precipitate, and its stability was further validated by performing ab initio molecular dynamic simulation study. FT723 exhibits strengthened basal texture, higher fraction of second phases, and particle-stimulated nucleation-assisted DRX grains compared to other two specimens, resulting in superior strength with comparable ductility. FT723 also exhibits superior corrosion resistance mainly due to the strengthened basal texture and lower dislocation density. All the specimens exhibit excellent antibacterial behavior with Gram-negative E. coli, Gram-positive Staphylococcus aureus, and Pseudomonas aeruginosa bacteria. 100% reduction of bacterial growth is observed within 24 h of culture of the specimens. Cytocompatibility was determined by challenging specimen extracts with the MC3T3-E1 cell lines. FT723 specimen exhibits the highest cell proliferation and alkaline phosphatase activity (ALP) because of its superior corrosion resistance. The ability of the specimens to be used in orthopedic implant application was evaluated by in vivo study in rabbit femur. Neither tissue-related infection nor the detrimental effect surrounding the implant was confirmed from histological analysis. Significant higher bone regeneration surrounding the FT723 specimen was observed in SEM analysis and fluorochrome labeling. After 60 days, the FT723 specimen exhibits the highest bone formation, suggesting it is a suitable candidate for orthopedic implant application.

Mechanism and growth kinetics of Al3Ti phase in fifteen-layered Ti Gr.1/A1050 clads produced with the explosive welding technique

This study was dedicated to the detailed characterization of the microstructural changes and the phase analysis of the interfaces formed in explosive welding of multilayered Ti Gr.1/A1050 clads. The significant effect of the detonation source localization on the microstructure of the welded materials interfaces after collision, and consequently on the diffusion processes induced by the elevated temperature was showed. Annealing process at 550 °C for series of time intervals of the Ti/Al clad allowed to determine the growth mechanism of the Al3Ti phase formed along particular interfaces. Moreover, the microstructure observations and calculations evidenced different growth mechanisms related to the localization of the Ti/Al interface in respect to the detonation source.

Phase development of lime-based plasters blended with waste calcined shale

AbstractRestoration of historical buildings requires an application of suitable and convenient materials which are compatible with historical legacy. On the other hand, the used materials have to show adequate durability and fulfil current tendencies of environmental-friendliness policy. Most historical buildings have their facades made of lime-based, or more precisely, blended-lime-based plasters. Metakaolin belongs to one of the most common representatives of pozzolanic admixtures used in this field. It is an artificial product, which arises by the calcination of kaolinitic clay or claystone at temperatures of about 550–900 °C. Like every other production process, a remarkable amount of waste rises also in the case of metakaolin. This study is aimed at the utilization of this waste, specifically the waste calcined shale (WCS). It is composed of not properly burned particles with varying compositions. Contrary to metakaolin, it contains a lower amount of amorphous phase and a higher amount of kaolinite and mullite. WCS was used in the production of lime-based plasters with a dosage of up to 50%. During the hardening, the carbonation process takes place in combination with the pozzolanic reactions. It gives rise to a higher amount of amorphous structures, about 15% in the case of pure lime contrary to up to 45% (in the highest dosage of WCS) and other crystal phases such as calcium-aluminate-carbonate hydrates. Obtained phase analyses are supported by the determination of SEM analysis and mechanical properties, which are also measured depending on time.

Bandgap engineering of novel Cu-vanadate/g-C3N4 hierarchical nanoflowers for enhanced photodegradation and excellent biosensing capability

Copper vanadate and graphitic carbon nitride (g-C3N4) are pivotal materials in the realm of advanced materials science, owing to their distinctive optical and electronic conductive properties. In the context of environmental photocatalysis and biosensing applications, their synergistic combination holds significant promise. Copper vanadate, renowned for its optical and electronic properties, complements the unique architecture and optical conduction characteristics of g-C3N4. Together, these materials exhibit immense potential for driving advancements in environmental sustainability and diagnostic techniques. In this study, we report the synthesis of copper vanadate (Cu0.261V2O5) and its composite with graphitic carbon nitride. XRD confirms the synthesis of the novel phase, FESEM and TEM analysis reveals hierarchical nanoflowers and UV-Visible spectroscopy divulges the visible light activation of the synthesized material and aids in the calculation of the optical bandgap. Interfacial charge transfer was studied with the help of EIS and Mott-Schottky analysis was employed to reveal the semiconductor type (n or p type) and determine the band edges. The as-prepared material was tested for the photocatalytic removal of methylene blue (MB), followed by the study of reaction kinetics, cyclic stability and active radicals participating in the photocatalysis process. The synthesized heterojunction showed 100 % removal of MB within a tenure of 90 minutes. The results of the experiment revealed that Cu0.261V2O5 decorated with g-C3N4 displays 1.5 and 1.4 times better photocatalytic degradation capability than pure Cu0.261V2O5 and g-C3N4, respectively. Furthermore, the synthesized material was evaluated for electrochemical biosensing of ascorbic acid in PBS (pH 7) analyte using a 3-electrode system. Compared to the pure material, the heterojunctions drew 1.9 times more current and provided near unity correlation (R2). It is evident that Cu0.261V2O5 decorated with g-C3N4 can be implemented for commercial eco-remediation and electrochemical ascorbic acid sensing.

Inclisiran in individuals with diabetes or obesity: Post hoc pooled analyses of the ORION-9, ORION-10 and ORION-11 Phase 3 randomized trials.

To conduct a pooled analysis of Phase 3 trials investigating the efficacy and safety of inclisiran across glycaemic and body mass index (BMI) strata. Participants were randomized 1:1 to receive 300 mg inclisiran sodium or placebo twice yearly, after initial and 3-month doses up to 18 months, with background oral lipid-lowering therapy. Analyses were stratified by glycaemic status (normoglycaemia, prediabetes, and diabetes) or BMI (<25, ≥25 to <30, ≥30 to <35, and ≥35 kg/m2). Co-primary endpoints were percentage and time-adjusted percentage change in low-density lipoprotein (LDL) cholesterol from baseline. Safety was also assessed. Baseline characteristics were balanced between treatment arms and across strata. Percent LDL cholesterol change (placebo-corrected) with inclisiran from baseline to Day 510 ranged from -47.6% to -51.9% and from -48.8% to -54.4% across glycaemic/BMI strata, respectively. Similarly, time-adjusted percentage changes after Day 90 and up to Day 540 ranged from -46.8% to -52.0% and from -48.6% to -53.3% across glycaemic/BMI strata, respectively. Inclisiran led to significant reductions in proprotein convertase subtilisin/kexin type 9 and other atherogenic lipids and lipoproteins versus placebo across the glycaemic/BMI strata. The proportions of individuals achieving LDL cholesterol thresholds of <1.8 mmol/L and <1.4 mmol/L with inclisiran increased with increasing glycaemic and BMI strata. Across the glycaemic/BMI strata, a higher proportion of individuals had mild/moderate treatment-emergent adverse events (TEAEs) at the injection site with inclisiran (2.8%-7.7%) versus placebo (0.2%-2.1%). Inclisiran provided substantial and sustained LDL cholesterol lowering across glycaemic/BMI strata, with a modest excess of transient mild-to-moderate TEAEs at the injection site.

Comparative study of luminescence in alkali‐metal‐based yttrium fluoride nanophosphor for biophotonic applications

AbstractAlkali‐metal‐based yttrium fluoride host (AY1‒xF4:xEu3+; A: Li/Na/K) nanophosphors were developed using co‐precipitation method. Phase analysis and emission spectral behavior were established for the said nanophosphors. The highest emission observed for NaYF4 doped with Eu3+ was then optimized to achieve maximum photoluminescence (PL) emission for varied dopant amount. The downconversion and upconversion PL studies revealed pure red emission under n‐ultraviolet and infrared excitations. The CIE coordinates are observed to be lie in the red hue of the CIE diagram. The PL decay curves reported to study lifetime of the emitting state and to identify quantum efficiency using Auzel's model for the said nanophosphor. Thermal stability was also evaluated from temperature‐sensitive luminescent spectra. The studies conducted on AYF4:.05Eu3+ (A: Li/Na/K) nanophosphors contemplates that NaYF4 nanophosphors doped with Eu3+ ions are best suited for biophotonic applications as the later one show relatively high emission.

Non‐destructive quantitative analysis of melt inclusions in extraterrestrial samples: Case study of chassignite via nanoscale X‐ray computed tomography

AbstractEstimation of the composition of planetary rocks and minerals is crucial for understanding their formation processes. In this study, we present the application of X‐ray nano‐computed tomography (nano‐XCT) for non‐destructive three‐dimensional (3‐D) phase analysis and estimation of phase abundances in rare Martian meteorite samples, specifically chassignite Northwest Africa (NWA) 2737. We determined the most suitable laser power for minimizing artifacts and maximizing phase contrast. By utilizing nano‐XCT, we successfully identified and segmented primary phases in the bulk meteorite sample. Additionally, we were able to locate and segment crystallized silicate melt inclusions within the meteorite. The phase abundances in bulk NWA 2737 and within melt inclusions calculated using nano‐XCT were in good agreement with previous studies that used thin section calculations, demonstrating the reliability of nano‐XCT as a non‐destructive alternative for estimating bulk phase abundances in rare samples. This study develops a benchmarking protocol and demonstrates the efficacy of nano‐XCT as a non‐destructive technique for generating an overview of phase distribution and assemblages of melt inclusions within rare samples. Future research can benefit from combining non‐destructive 3‐D phase assemblage estimations with non‐destructive 3‐D chemical analysis techniques to achieve a fully non‐destructive parental magma composition estimation of rare cumulate samples.

Manufacturing of High Purity Cr2AlC MAX Phase Material and Its Characterization

AbstractPresent study discusses about a technique for producing high-purity Cr2AlC MAX phase materials and gaining insight into their thermal behavior for high-temperature applications. The research conducted involved synthesizing a pure layered ternary carbide Cr2AlC MAX phase material by mixing powders of Chromium, Aluminum, and Carbon and then subjecting them to two-step pressureless sintering process in argon atmosphere. First step involves the annealing of ball-milled mixture at 750 °C for 2 h followed by the second step in which the annealed mixture is subjected to heat-treatment at 1350 °C for 2 h. Analysis using XRD and Raman techniques revealed that the synthesized product consists of Cr2AlC phase, without any impurities. SEM studies confirmed that the Cr2AlC had a layered topography, while EPMA analysis indicated that the atomic percentage of Cr, Al, and C was consistent with the XRD phase analysis. XPS investigations confirmed the presence of Cr-C bonds representing Mn+1Xn of the MAX phase material. TG-DSC results showed an approximately 2% increase in weight. The Cr2AlC phase exhibited an endothermic pattern below 725 °C, an exothermic pattern above it, and did not decompose up to 1400 °C in vacuum environment. High-temperature XRD analysis at various temperatures also confirmed no formation of Al2O3 or CrO impurity compounds.

A growth phase analysis on the influence of light intensity on microalgal stress and potential biofuel production

It is urgent to find alternatives to fossil fuels to mitigate the effects of climate change. High light intensity during microalgal growth can promote lipid and carbohydrate accumulation (feedstocks to biofuels). However, more research needs to be done concerning the effect of this factor on microalgal productivity and biochemical composition from a growth phase point of view. This study evaluated the impact of high light intensities (291, 527 and 1107 μmol m−2 s−1) on Chlorella vulgaris growth in synthetic wastewater, nutrient assimilation and biochemical composition in late-exponential and stationary growth phases. Under the highest light intensity, a higher growth rate (0.54 ± 0.02 d−1) and maximum productivity (166 ± 13 mg/L d−1) were achieved. Also, nutrient removal efficiencies at the late-exponential phase reached 97.0 ± 0.2 % and 98.2 ± 0.1 % for nitrogen and phosphorus, respectively. Under all light intensities tested at the stationary phase, microalgae also achieved high nutrient removal efficiencies (>95 %). Extreme light intensity (1107 μmol m−2 s−1) boosted the accumulation of carbohydrates (30 ± 3 % w/w) and lipids (13.0 ± 0.4 % w/w). Under lower light intensities, the content of these compounds did not change significantly between growth phases. The chlorophyll content decreased with the increasing light intensity and increasing exposure time. Exposing C. vulgaris to high light intensity seems promising to simultaneously treat wastewater and boost lipid and carbohydrate accumulation, which can be used for biofuel production.

The effect of aquathermolysis catalyst on the processing of Yarega oil

This study focuses on the synthesis of oil-soluble precursor catalysts using iron and nickel and evaluates their performance through laboratory simulations of aquathermolysis processes under varying temperature and duration conditions. The investigation highlights that the initial oil sample exhibits high resin content (27 %) and asphaltenes (∼4 %). Gas phase analysis reveals a significant increase in the levels of n-C1-C5 hydrocarbons and C4–C10 isomers (up to 3.5–4 times compared to control experiments), indicating substantial alterations in the oil's composition. After thermal steam treatment (TST), the viscosity of all samples decreases in comparison to the initial oil. For instance, when using an iron talate catalyst, the viscosity drops to 575 mPa s, which is approximately 10.5 times lower than the initial oil viscosity of 6027 mPa s. Additionally, experiments involving iron-based catalysts consistently exhibit reduced viscosity compared to control experiments, achieving a 2.2-fold decrease after a 72-h duration (from 1928 mPa s to 743 mPa s).Economic evaluations were conducted, demonstrating an additional oil production increase of 2855 tons. The net discounted income over a span of 4 years, resulting from the application of this catalytic aquathermolysis technology, totaled 40,652,750 russian rubles.

Analysis of phase, microstructure, and mechanical characteristics of selective laser melted AlSi10Mg alloy after post-heat treatment

Analysis of phase, microstructure, and mechanical characteristics of selective laser melted AlSi10Mg alloy after post-heat treatment

Evaluation of the Efficiency of Using an Oxidizer in the Leaching Process of Gold-Containing Concentrate

This article presents the results of cyanide leaching of gold-containing concentrate using the trichlorocyanuric acid (TCCA) oxidizer. Gold-containing concentrate was obtained from a gold tailings sample from a gold recovery factory (GRF) in one of the deposits of Kazakhstan that have not previously been studied for concentrability. According to X-ray phase analysis and energy dispersive spectrometry (DSM) data, the main compounds in the tailings sample under study are pyrite FeS2, quartz SiO2, calcite CaCO3, albite NaAlSi3O8, muscovite KAl2Si3AlO10(OH)8, dolomite CaMg(CO3)2, and oxidized iron compounds. Microscopic studies of the concentrate have established the presence of ultrafine gold with sizes from Au 0.9 to 10.2 μm in pyrite. Obtaining the gold-containing concentrate with a gold content of 15.95 g/t is possible according to the enrichment scheme, which includes centrifugal separation, classification according to the fineness class −0.05 mm, additional grinding of hydrocyclone sands to a fineness of 90.0–95.0% of the class finer than 0.050 mm, and control centrifugal separation. Since pyrite in technogenic raw materials is the main gold-containing mineral, this paper presents studies on the oxidizability of pyrite with the TCCA oxidizer. The results of studies on the oxidation of pyrite using the TCCA oxidizer show the products of its hydrolysis oxidize pyrite with the formation of various iron compounds on its surface. Pretreatment of gold-containing concentrate with oxidizer TCCA for 3 h before the cyanidation process (20 h) allows for an increase in the recovery of gold in the solution by 5.8%.

The Influence of the Soil Profile on the Formation of the Elemental Image of Grapes and Wine of the Cabernet Sauvignon Variety.

The features for assessing the authenticity of wines by region of origin are studied, based on the relationship between the mineral composition of the wine, the grapes, and the soil profile (0 to 160 cm) from the place of growth of Cabernet Sauvignon grapes. Soil, grape, and wine samples were taken from the territories of six vineyards in the Anapa district of Krasnodar Territory, Russia. Using the methods of ICP-OES, thermal, and X-ray phase analysis, the soils were differentiated into three groups, differing in mineralogical and mineral compositions. The soil samples of the first group contained up to 31% quartz, the second group up to 25% quartz and 19% mixed calcite, and the third group up to 32% calcite and 15% quartz. The formation of the elemental image of the grapes was studied, taking into account the total content and mobile forms of metals in the soil. The territorial proximity of the vineyards did not affect the extraction of elements from the soil into the grape berry, and the migration of metals for each territory was selective. According to the values of the biological absorption coefficient, the degree of transition of metals from the soil to a berry was estimated. For K, Ti, Zn, Rb, Cu, and Fe in all berries, the coefficient was higher than 1.00, which means that the berry extracts contained not only mobile-form, but also difficult-to-dissolve metal compounds. The migration of macro-components from the soil to the berry was low, and amounted to 6-7% for Ca, 0.8-3.0% for Na, and 25-70% for Mg of the concentration of their mobile forms. For all territories, the maximum correlation between metal concentrations in grapes and soil was observed for samples from a depth of 0-40 cm. The discriminant model based on concentrations of Rb, Al, K, Sr, Co, Na, Pb, Ca, and Ni showed the formation of clusters in the territories of vineyard cultivation. The developed model allow the problems of identifying wines by region to be solved with high accuracy, using their elemental image.

Comprehensive Analysis on GPS Carrier Phase under Various Cutoff Elevation Angles and Its Impact on Station Coordinates’ Repeatability

When processing the carrier phase, the global navigation satellite system (GNSS) grants the highest precision for geodetic measurements. The analysis centers (ACs) from the International GNSS Service (IGS) provide different data such as precise clock data, precise orbits, reference frame, ionosphere and troposphere data, as well as other geodetic products. Each individual AC has its own strategy for delivering the abovementioned products, with one of the key elements being the cutoff elevation angle. Typically, this angle is arbitrarily chosen using generic values without studying the impact of this choice on the obtained results, in particular when very precise positions are considered. This article addresses this issue. To this end, the article has two key sections, and the first is to evaluate the impact of using the two different cutoff elevation angles that are most widely used: (a) 3 degrees cutoff and (b) 10 degrees cutoff elevation angle. This analysis is completed in two major parts: (i) the analysis of the root mean square (RMS) for the carrier phase and (ii) the analysis of the station position in terms of repeatability. The second key section of the paper is a comprehensive carrier phase analysis conducted by adopting a new approach using a mean of the 25-point average RMS (A-RMS) and the single-point RMS and using an ionosphere-free linear combination. By using the ratio between the 25-point average RMS and the single-point RMS we can define the type of scatter that dominates the phase solution. The analyzed data span a one-year period. The tested GNSS stations belong to the EUREF Permanent Network (EPN) and the International GNSS Service (IGS). These comprise 55 GNSS stations, of which only 23 GNSS stations had more than 95% data availability for the entire year. The RMS and A-RMS are analyzed in conjunction with the precipitable water vapor (PWV), which shows clear signs of temporal correlation. Of the 23 GNSS stations, three stations show an increase of around 50% of the phase RMS when using a 3° cutoff elevation angle, and only four stations have a difference of 5% between the phase RMS when using both cutoff elevation angles. When using the A-RMS, there is an average improvement of 37% of the phase scatter for the 10° cutoff elevation angle, whereas for the 3° cutoff elevation angle, the improvement is around 33%. Based on studying this ratio, four stations indicate that the scatter is dominated by the stronger-than-usual dominance of long-period variations, whereas the others show short-term noise. In terms of station position repeatability, the weighted root mean square (WRMS) is used as an indicator, and the results between the differences of using a 3° and 10° cutoff elevation angle strategy show a difference of −0.16 mm for the North component, −0.21 mm for the East component and a value of −0.75 mm for the Up component, indicating the importance of using optimal cutoff angles.