Elemental Components Research Articles

Electron probe microanalysis of the elemental composition of phytoliths from woody bamboo species.

Electron probe microanalysis (EPMA) is promising for accurately determining elemental components in micro-areas of individual phytolith particles, interpreting compositional features and formation mechanisms of phytoliths in plants, identifying archeological and sedimental phytolith. However, the EPMA method of analyzing mounted slide phytoliths has not well been defined. In this study, we attempted different EPMA methods to determine the elemental compositions of phytoliths in mounted slides. Direct analysis of carbon (DAC) with other elements in phytolith could obtain abnormally high total values and carbon values. The method of carbon excluded in measuring elements (non-carbon analysis (NCA)) was feasible to obtain elemental compositions in phytolith. The NCA method was conducive to obtain the factual elemental compositions of an individual phytolith (morphotype) when the carbon content of phytolith was relatively low. The EPMA results of phytoliths from 20 bamboo species (three genera) showed that phytolith was dominantly composed of SiO2 but also included low contents of diverse other elements. The EPMA of phytoliths can provide the elemental composition of micro-areas of an individual phytolith particle. The elemental compositions of phytolith varied with their morphotypes, the genera and ecotype of bamboos. The EPMA of elemental compositions in phytoliths is a potential tool to study the formation mechanism of phytoliths, plant taxonomical identification, archaeological and paleoenvironmental reconstruction.

Exposure models for particulate matter elemental concentrations in Southern California.

Due to a scarcity of routine monitoring of speciated particulate matter (PM), there has been limited capability to develop exposure models that robustly estimate component-specific concentrations. This paper presents the largest such study conducted in a single urban area. Using samples that were collected at 220 locations over two seasons, quasi-ultrafine (PM0.2), accumulation mode fine (PM0.2-2.5), and coarse (PM2.5-10) particulate matter concentrations were used to develop spatiotemporal regression, machine learning models that enabled predictions of 24 elemental components in eight Southern California communities. We used supervised variable selection of over 150 variables, largely from publicly available sources, including meteorological, roadway and traffic characteristics, land use, and dispersion model estimates of traffic emissions. PM components that have high oxidative potential (and potentially large health effects) or are otherwise important markers for major PM sources were the primary focus. We present results for copper, iron, and zinc (as non-tailpipe vehicle emissions); elemental carbon (diesel emissions); vanadium (ship emissions); calcium (soil dust); and sodium (sea salt). Spatiotemporal linear regression models with 17 to 36 predictor variables including meteorology; distance to different classifications of roads; intersections and off ramps within a given buffer distance; truck and vehicle traffic volumes; and near-roadway dispersion model estimates produced superior predictions over the machine learning approaches (cross validation R-squares ranged from 0.76 to 0.92). Our models are easily interpretable and appear to have more effectively captured spatial gradients in the metallic portion of PM than other comparably large studies, particularly near roadways for the non-tailpipe emissions. Furthermore, we demonstrated the importance of including spatiotemporally resolved meteorology in our models as it helped to provide key insights into spatial patterns and allowed us to make temporal predictions.

A Study on the Characteristics of Ion, Carbon, and Elemental Components in PM2.5 at Industrial Complexes in Ansan and Siheung

A Study on the Characteristics of Ion, Carbon, and Elemental Components in PM_2.5 at Industrial Complexes in Ansan and Siheung

A sustainable strategy for preparation of flame-retardant cotton fabric by phosphorylation of recycled cotton

The recycling and reutilization of cotton waste are in line with the sustainable development of society. Therefore, in this work, an environmentally friendly cellulose phosphate ammonium salt was synthesized by phosphorylation of cotton waste. Then the cotton fabrics were modified with cellulose phosphate ammonium salt by using the dip–dry–cure technique to obtain flame-retardant cotton fabric. The surface morphology, characteristic functional groups, and elemental components were characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy. The results indicated that the cellulose phosphate ammonium salt was immobilized onto the cotton fabric through a P–O–C chemical bond. Vertical combustion tests before and after washing showed that the treated cotton fabric had durable flame-retardant properties. Thermogravimetry demonstrated that the treated cotton fabric retained a large amount of residual char and the pyrolysis temperature was significantly earlier than that of the control sample. Compared with the blank sample, the peak of heat release rate and total heat release of the modified fabric was reduced by 90.8% and 84.1%, respectively. Thermogravimetric infrared of flame-retardant cotton fabric proved that cellulose phosphate ammonium salt acted both in the gas and condensed phase during the decomposition of the treated fabric.

Dealloying-induced phase transformation in Fe–Rh alloys

Nanoporous metals produced by dealloying have aroused enormous interest due to exotic mechanical and physico-chemical properties that are usually inaccessible in their bulk form. Interestingly, when binary solid-solution alloys, such as Ag–Au alloys, are dealloyed, the resulting nanoporous metals usually inherit the crystal structure of their parent alloys. In this Letter, we examined the evolution of the crystal structure during the dealloying of Fe–Rh alloys that show single-phase solubility over a large range of compositions. In situ x-ray diffraction shows that the crystallographic structure of the Fe85Rh15 alloy transforms from the original bcc to fcc structure during the dealloying. Transmission electron microscopy confirms the fcc structure of the nanoporous sample, which exhibits a typical bi-continuous porous structure with ligament sizes of only 2–3 nm and a high Fe concentration. The bcc–fcc transformation is driven by the chemical disordering of Fe and Rh atoms, induced by the highly dynamic dissolution and diffusion process at the alloy/electrolyte interface. Our study highlights the massive diffusion and the consequent disordered arrangement of elemental components during the evolution of the nanoporous structure.

Changes in Ackee Starch as Affected by Annealing and Heat Moisture Treatment

The effect of Annealing and Heat Moisture Treatment (HTM) were investigated, on the physicochemical properties of Ackee Seeds Starch (ASS). The ASS was evaluated for moisture, ash contents, pH, loose and packed bulk densities. While the functional characteristics, Scanning Electron Microscopy, Energy Dispersive Spectroscopy (SEM/EDS), color and pasting characteristics were also determined. Results obtained showed, that there were significant (p<0.05) differences in the proximate contents. The moisture contents were decreased by HTM samples, but were increased by annealing. The ash content was not significantly affected, while the pH was reduced by modifications. The treatments were found to decrease the Oil Holding Capacity, while it increased Water Holding Capacity. The packed densities of the ASS were not affected by modification, but the loosed densities were reduced significantly (p<0.05). Temperature and modification reduced the swelling capacity of the ASS. The SEM observation showed that starch granules were oval, elongated and smooth surfaced in the HMT samples, but smaller, clustered and rough surfaced in the native and annealed samples. The EDS analyses showed varied changes in the elemental components of the ASS affected by modification. The lightness ( L*) value of the native ASS was highest while modifications lower the values. The peak viscosity was significantly (p<0.05) reduced by the modification of the starch. These results indicated, that treatment of the Ackee starch had significant (p<0.05) and desirable effects on the physicochemical properties and thus will reduce wastage of the seed and offer good industrial application of the starch.

Fragmentation and mineral transformation behavior during combustion of char produced at elevated pressure

Due to the higher efficiency and more compact structure, pressurized oxy-coal combustion system is promising in carbon capture and storage. However, coal conversion behaviors, e.g., pyrolysis products, char fragmentation and burnout, would be changed at higher pressure, which may dramatically influence the subsequent particulate matter formation. This research discusses the fragmentation and subsequent aerosol formation capacity of char produced at elevated pressure. The prepared char samples at increased pressure are combusted in an atmospheric drop tube furnace. Results show that, for Yulin coal, raw coal forms larger amount of fine mode particulate matter than char due to the volatile-char interaction. The fragmentation of char produced at higher pressure is notably enhanced due to the formed thin and breakable wall. For char produced at 7 atm, the yields of particles diameter lower than 10 μm are increased by 56% compared with 1 atm char. While among char samples, the portion of particulate matter distributed in three modes is similar. Meanwhile, more volatile elements are found in fine mode particulate matter derived from higher pressure char. For Neimeng coal, the char swelling, fragmentation and particulate matter emission is quite different with Yulin coal. The coal swelling is not noticeable in all cases, and the difference of char fragmentation behavior among char samples is mainly due to the volatile content in char. In addition, clear discrepancy of elemental components in particulate matter produced by Neimeng chars is not detected. This work will contribute to reveal the relationship between char evolution and subsequent particulate matter emission during pressurized oxy-coal combustion.

Wet Scavenging in Removing Chemical Compositions and Aerosols: A Case Study Over the Lake Urmia

AbstractLake Urmia, NW Iran, and S Caucasus region, has lost approximately three‐fourth of its water volume resulting in increased exposure of lacustrine deposits. Therefore, the role of Lake Urmia desiccated saline lands on local aerosols and rainwater compositions is still vague. This study investigates the temporal and seasonal patterns of rainwater chemistry from January 2018 to June 2018 (six months) in 13 stations throughout the Lake Urmia basin. The samples collected were analyzed using triple quadrupole inductively coupled plasma mass spectrometry (ICP‐QQQ) and ion chromatography (IC) to measure elemental and ionic concentrations. Then, the Hybrid Single‐Particle Lagrangian Integrated Trajectory model (HYSPLIT) was applied to identify the pathway and contribution of emissions. The results depict that the concentration of elemental and ionic components over different parts of the Lake Urmia basin are significantly different. West and north directions have the highest concentrations of marine ions associated with fewer toxic elements. In contrast, the east and south directions show a high concentration of heavy metal elements and ions. The high level of heavy and toxic elements at the east and south directions indicates that local anthropogenic sources are more influential. The seasonal and monthly variabilities of chemical compositions depict that the highest concentration of Na+, Mg2+, Ca2+, K+, Cl−, Br−, NO3−, Al, Cr, Mn, Fe, and Co were in the spring season and SO42−, NH4+ and NO2− were highest in winter. Seasonal variation for MSA, organic acids (i.e., Pyruvate, Adipate, and Oxalate), Ni, Cu, Zn, V, and Ti were not apparent. Cluster‐mean HYSPLIT backward trajectories results show the most dominant air mass sectors are from W (a: Iraq, Syria, and Arabian deserts; b: Mediterranean Sea; and c: KSA) and NE (the Caspian Sea and its vicinity), contributed to almost 65% and 22%, respectively. These air masses bring a significant quantity of crustal and marine aerosols, respectively. It is inferred that the Lake Urmia dried‐up lakebeds have less impact on the contribution of emissions across the region.

Source Analysis of Ambient PM2.5 in Wuhan City Based on Random Forest Model

Based on the online monitoring data of fine particle(PM2.5) mass concentration, carbonaceous components, ionic constituents, and elemental components in an urban site of Wuhan from December 2019 to November 2020, the chemical characteristics of PM2.5 were analyzed. In addition, seasonal source apportionment of PM2.5 was conducted using the principal component analysis(PCA) method and random forest(RF) algorithm model. The results indicated that ρ(PM2.5) was the highest in winter[(61.33±35.32) μg·m-3] and the lowest in summer[(17.87±10.06) μg·m-3]. Furthermore, organic carbon(OC), with a concentration of(7.27±3.51) μg·m-3, accounted for the major proportion compared with that of elemental carbon(EC) in the carbonaceous component of PM2.5. NO3-, SO42-, and NH4+ had the highest proportion in ionic components, with concentrations of (11.55±3.86),(7.55±1.53), and (7.34±1.99) μg·m-3, respectively. K, Fe, and Ca were the main elements in elemental components, with concentrations of (752.80±183.98),(542.34±142.55), and (459.70±141.99) ng·m-3, respectively. Relying on main factor extraction by PCA and quantitative analysis by RF, five emission sources were ultimately confirmed. The seasonal concentration distribution of these emission sources was as follows:coal burning and secondary sources(46%, 39%, 41%, and 52% for spring, summer, autumn, and winter, respectively) made the highest contribution to PM2.5, followed by vehicle emission sources(22%, 28%, 27%, and 21%), industrial emission sources (14%, 18%, 17%, and 13%), dust sources (10%, 8%, 6%, and 6%), and biomass burning sources (8%, 7%, 9%, and 8%). The valuation of the RF model was evaluated using multiple indicators, including RMSE, MSE, and R2. The evaluation results showed that the model for winter had the best performance (R2=0.974, RMSE=3.795 μg·m-3, MAE=2.801 μg·m-3), the models for spring (R2=0.936, RMSE=3.512 μg·m-3, MAE=2.503 μg·m-3) and autumn (R2=0.937, RMSE=4.114 μg·m-3, MAE=3.034 μg·m-3) performed with moderate-fitting goodness, and the summer model showed a relatively weak-fitting performance (R2=0.866, RMSE=5.665 μg·m-3, MAE=3.889 μg·m-3). The RF model had a satisfactory performance in PM2.5 source apportionment and had excellent prospects in analyzing massive historical data of air pollutants.

Effects of hydration parameters on chemical properties of biocrudes based on machine learning and experiments

To investigate the effects of temperature and biomass concentration of Hydrothermal liquefaction (HTL) on chemical properties of biocrudes, machine learning (ML) was used to predict the weight of hydration parameters on the properties of biocrudes. The elemental compositions, molecular weights, functional groups, thermal degradation, molecular structure of biocrudes were studied. The optimum yield of biocrudes was 65% and the highest heat value reached up to 34.28 kJ/g, showing comparable fuel properties. It was found that the hydration temperature significantly affects the elemental components, functional groups and molecular weight and structures of biocrudes. In addition, biomass concentration also affect the functional groups and structures of biocrudes. ML results indicated that Support Vector Machine Linear Kernel method is suitable for heat value prediction.

Particulate Matter Ionic and Elemental Composition during the Winter Season: A Comparative Study among Rural, Urban and Remote Sites in Southern Italy

We present an overview of the concentrations and distributions of water-soluble ion species and elemental components in ambient particulate matter for five measurement sites in southern Italy with the aim of investigating the influence of the different site characteristics on PM levels. The sites encompass different characteristics, ranging from urban to coastal and high-altitude remote areas. PM10 and PM2.5 fractions were collected simultaneously using dual channel samplers during the winter period from November 2015 to January 2016 and analyzed for water-soluble ion species, using ion chromatography, and elemental composition, using inductively coupled plasma mass spectrometry (ICP-MS). In all sites, PM2.5 represented the higher contribution to particulate mass, usually more than two times that of the coarse fraction (PM2.5−10). At the coastal site in Capo Granitola (Western Sicily), sea salts constituted about 30% of total PM10 mass. On average, ion species accounted for 30% to 60% of total PM10 mass and 15% to 50% of PM2.5 mass. We found that secondary ion species, i.e., SO42−, NO3− and NH4+ dominated the identifiable components within both PM2.5 and PM10 fractions. The chlorine–sodium ratio was usually lower than that expected from the natural level in sea salt, evidencing aged air masses. At the monitoring site in Naples, a highly urbanized area affected by high levels of anthropogenic source emissions, an increased contribution of ammonium was found, which was imputed to the increased ammonia emissions from industrial combustion sources and road traffic. The concentrations of the investigated elements showed noteworthy differences from one site to another. The PM10 fraction was highly enriched by sources of anthropogenic origin in the samples from the most urbanized areas. In general, the enrichment factors of the elements were similar between the PM10 and PM2.5 fractions, confirming common sources for all elements.

Ground calibration and validation of laser-induced breakdown spectroscopy for the Mars surface composition detector

<p indent=0mm>In the Tianwen-1 mission, China’s first Mars exploration, the lander/rover had safely landed in the south Utopian plain and conducted a series of scientific explorations. The Mars surface composition detector (MarSCoDe) equipped on the Zhurong rover uses remote laser-induced breakdown spectroscopy (LIBS) and short-wave infrared spectroscopy to perform the <italic>in situ</italic> detection of the elemental composition of surface soils, rocks, and minerals on Mars. In this paper, first, the basic components of this instrument suite are introduced. Second, the LIBS principle is described. Third, the spectral and radiation calibration of the LIBS spectrometer and its surveying distance and pointing angle calibration are described. Finally, the performance associated with the navigation and terrain cameras (NaTeCam) is presented. The results from the joint detection and analysis of the MarSCoDe and the NaTeCam show that the MarSCoDe can accurately fire the target and determine the elemental components.

Long-term exposure to ambient air pollution and bladder cancer incidence in a pooled European cohort: the ELAPSE project.

The evidence linking ambient air pollution to bladder cancer is limited and mixed. We assessed the associations of bladder cancer incidence with residential exposure to fine particles (PM2.5), nitrogen dioxide (NO2), black carbon (BC), warm season ozone (O3) and eight PM2.5 elemental components (copper, iron, potassium, nickel, sulfur, silicon, vanadium, and zinc) in a pooled cohort (N = 302,493). Exposures were primarily assessed based on 2010 measurements and back-extrapolated to the baseline years. We applied Cox proportional hazard models adjusting for individual- and area-level potential confounders. During an average of 18.2 years follow-up, 967 bladder cancer cases occurred. We observed a positive though statistically non-significant association between PM2.5 and bladder cancer incidence. Hazard Ratios (HR) were 1.09 (95% confidence interval (CI): 0.93-1.27) per 5 µg/m3 for 2010 exposure and 1.06 (95% CI: 0.99-1.14) for baseline exposure. Effect estimates for NO2, BC and O3 were close to unity. A positive association was observed with PM2.5 zinc (HR 1.08; 95% CI: 1.00-1.16 per 10 ng/m3). We found suggestive evidence of an association between long-term PM2.5 mass exposure and bladder cancer, strengthening the evidence from the few previous studies. The association with zinc in PM2.5 suggests the importance of industrial emissions.

THEORETICAL AND ORGANIZATIONAL ASPECTS OF THE MECHANISM OF LENDING TO AGRICULTURAL ENTERPRISES

Introduction. Bank lending to farmers remain one of the most important issues that need in-depth research and improvement, as the problem of lack of working capital and relatively low efficiency of production and economic activities of agricultural enterprises is only exacerbated. An effective system of bank lending is able to solve this problem. Methods. In the process of research a number of methods were used: abstract and logical - to determine the essence of the concept, structure and elemental composition of the credit mechanism of agriculture; methods of comparative analysis and synthesis - for study modern aspects of the organization of bank lending to agricultural enterprises; monographic - for identifying and systematizing specific features of the organization of the credit process in the agricultural sector of the economy; structural-functional approach – to form a conceptual vision of the credit mechanism of the agro-industrial complex and its institutional support; graphic - to illustrate and systematize the results of the study; method of analysis of hierarchies - to substantiate the criterion hierarchical system of choice by the borrower of a banking institution. Results. Theoretical views on the essence, structure and elemental composition of the credit mechanism of agro-industrial complex are systematized. The author's vision of the essence of the credit mechanism of agro-industrial complex is formulated, the structuring of its priority elemental components is offered. The algorithm of relations and interactions between the lender and the borrower as subjects of crediting is systematized. The specifics of the bank's credit policy in relation to agricultural enterprises are identified and the range of credit products for financing their working capital and investment is analysed. The directions of increase of efficiency of cooperation of banks with agrarians in the field of crediting are offered. Discussion. The obtained results of the research can be used by the bodies of branch management of the agrarian sector of the economy, as well as by banking institutions in the development of measures and directions for optimization and improvement of lending to agricultural enterprises. Prospects for further research are systematization and refinement of methodological aspects of assessing the impact of bank lending on agricultural security of the state, as well as testing methods of economic and mathematical modelling to assess the impact of bank lending to agricultural enterprises on the gross product of the agricultural sector and GDP. Keywords: credit mechanism; credit process; credit relations; bank credit; risk; creditor; the borrower; credit product; state support.

Valence Band Dispersion Embedded in Resonant Auger Electrons

Resonant photoelectron spectroscopy highlights certain elemental components of the valence band by adjusting the photon energy to a core-level excitation threshold, allowing the study of the elemen...

Long-term exposure to fine particle elemental components and mortality in Europe: Results from six European administrative cohorts within the ELAPSE project

Evidence for the association between long-term exposure to ambient particulate matter components and mortality from natural causes is sparse and inconsistent. We evaluated this association in six large administrative cohorts in the framework of the Effects of Low-Level Air Pollution: A Study in Europe (ELAPSE) project.We analyzed data from country-wide administrative cohorts in Norway, Denmark, the Netherlands, Belgium, Switzerland and in Rome (Italy). Annual 2010 mean concentrations of copper (Cu), iron (Fe), potassium (K), nickel (Ni), sulfur (S), silicon (Si), vanadium (V) and zinc (Zn) in fine particulate matter (PM2.5) were estimated using 100 × 100 m Europe-wide hybrid land use regression models assigned to the participants' residential addresses. We applied cohort-specific Cox proportional hazard models controlling for area- and individual-level covariates to evaluate associations with natural mortality. Two pollutant models adjusting for PM2.5 total mass or nitrogen dioxide (NO2) were also applied. We pooled cohort-specific estimates using a random effects meta-analysis.We included almost 27 million participants contributing more than 240 million person-years. All components except Zn were significantly associated with natural mortality [pooled Hazard Ratios (HRs) (95% CI): 1.037 (1.014, 1.060) per 5 ng/m3 Cu; 1.069 (1.031, 1.108) per 100 ng/m3 Fe; 1.039 (1.018, 1.062) per 50 ng/m3 K; 1.024 (1.006, 1.043) per 1 ng/m3 Ni; 1.036 (1.016, 1.057) per 200 ng/m3 S; 1.152 (1.048, 1.266) per 100 ng/m3 Si; 1.020 (1.006, 1.034) per 2 ng/m3 V]. Only K and Si were robust to PM2.5 or NO2 adjustment [pooled HRs (95% CI) per 50 ng/m3 in K: 1.025 (1.008, 1.044), 1.020 (0.999, 1.042) and per 100 ng/m3 in Si: 1.121 (1.039, 1.209), 1.068 (1.022, 1.117) adjusted for PM2.5 and NO2 correspondingly].Our findings indicate an association of natural mortality with most components, which was reduced after adjustment for PM2.5 and especially NO2.

β-Cyclodextrin-Modified Mesoporous Silica Nanoparticles with Photo-Responsive Gatekeepers for Controlled Release of Hexaconazole

In the present research, photo-responsive controlled-release hexaconazole (Hex) nanoparticles (Nps) were successfully prepared with azobenzene (Azo)-modified bimodal mesoporous silica (BMMs), in which β-cyclodextrin (β-CD) was capped onto the BMMs-Azo surface via host–guest interactions (Hex@BMMs/Azo/β-CD). Scanning electron microscopy (SEM) confirmed that the nanoparticles had a spherical structure, and their average diameter determined by dynamic light scattering (DLS) was found to be 387.2 ± 3.8 nm. X-ray powder-diffraction analysis and N2-adsorption measurements indicated that Hex was loaded into the pores of the mesoporous structure, but the structure of the mesoporous composite was not destroyed. The loading capacity of Hex@BMMs/Azo/β-CD nanoparticles for Hex was approximately 27.3%. Elemental components of the nanoparticles were characterized by X-ray photoelectron spectroscopy (XPS) and electron dispersive spectroscopy (EDS). Ultraviolet–visible-light (UV–Vis) absorption spectroscopy tests showed that the azophenyl group in BMMs-Azo undergoes effective and reversible cis-trans isomerization under UV–Vis irradiation. Hex@BMMs/Azo/β-CD Nps exhibited excellent light-sensitive controlled-release performance. The release of Hex was much higher under UV irradiation than that in the dark, which could be demonstrated by the bioactivity test. The nanoparticles also displayed excellent pH-responsive properties, and the sustained-release curves were described by the Ritger–Peppas release kinetic model. BMMs nanocarriers had good biological safety and provided a basis for the development of sustainable agriculture in the future.

Information on elemental and ionic components obtained from aircraft engine smoke number filter sample

To extract information on elemental and ionic species components and particulate matter (PM) characteristics from smoke number (SN) filter paper, we were performed elemental analysis by micro-PIXE and ion component analysis by ion chromatography. As a result of elemental and ionic species component analysis of the SN filter, information on the chemical composition of jet engine exhaust PM was obtained. Regarding the SN filter, jet engine exhaust PM was collected for each difference in engine thrust of various aircraft engines at aircraft turbine engine test cells around the world. By periodically analyzing the chemical composition of the SN filter, it is possible to identify the characteristics of the emission PM of each aircraft engine and the transformation of the chemical composition of the emission PM with the passage of time. This was thought to lead to the evaluation of jet engines.

Generating Concentrically Embedded Spatially Divided OAM Carrying Vortex Beams Using Transmitarrays

To effectively exploit the orbital angular momentum (OAM) characteristics, it is essential to have devices which are capable of generating beams with multiple OAM modes simultaneously. Most of the proposed techniques commonly require time division multiplexing at the transmitter side or beam splitters at the reception side for separating OAM modes and directing beams of different OAM modes to different directions. To overcome this problem, here, the concept of aperture sharing for generating concentrically embedded OAM-carrying beams is presented. Such a methodology provides embedded beams of various OAM modes which are launched toward a single direction through a shared aperture of transmitarray (TA), while having a spatial division between them. In this manner, the transmitted beams are initially separated by the hardware at the transmitter level. A novel circularly polarized (CP) substrate-coupled unit cell is designed and used as the elemental components on the aperture of the TA. Three prototype TAs are realized for investigating different cases of the OAM modes embedding and verifying the effectiveness of the proposed method. The obtained simulated and experimental results are consistent which validate the novel technique.

Ultrafine particles, particle components and lung function at age 16years: The PIAMA birth cohort study.

Particulate matter (PM) air pollution exposure has been linked to lung function in adolescents, but little is known about the relevance of specific PM components and ultrafine particles (UFP). To investigate the associations of long-term exposure to PM elemental composition and UFP with lung function at age 16years. For 706 participants of a prospective Dutch birth cohort, we assessed associations of forced expiratory volume in 1s (FEV1) and forced vital capacity (FVC) at age 16 with average exposure to eight elemental components (copper, iron, potassium, nickel, sulfur, silicon, vanadium and zinc) in PM2.5 and PM10, as well as UFP during the preceding years (age 13-16years) estimated by land-use regression models. After assessing associations for each pollutant individually using linear regression models with adjustment for potential confounders, independence of associations with different pollutants was assessed in two-pollutant models with PM mass and NO2, for which associations with lung function have been reported previously. We observed that for most PM elemental components higher exposure was associated with lower FEV1, especially PM10 sulfur [e.g. adjusted difference -2.23% (95% confidence interval (CI) -3.70 to -0.74%) per interquartile range (IQR) increase in PM10 sulfur]. The association with PM10 sulfur remained after adjusting for PM10 mass. Negative associations of exposure to UFP with both FEV1 and FVC were observed [-1.06% (95% CI: -2.08 to -0.03%) and -0.65% (95% CI: -1.53 to 0.23%), respectively per IQR increase in UFP], but did not persist in two-pollutant models with NO2 or PM2.5. Long-term exposure to sulfur in PM10 may result in lower FEV1 at age 16. There is no evidence for an independent effect of UFP exposure.