Heavy metals contamination and ecological risks in agricultural soils of Usak, western Türkiye: a geostatistical and multivariate analysis.

This research aimed to determine and evaluate the concentrations of As, Cu, Hg, Ni, and Pb, and the physicochemical properties of 48 agricultural soil samples, to identify potential ecological risks and their sources associated with heavy metals contamination in Usak, western Türkiye. Various methods were used to assess ecological risks, including geoaccumulation index (Igeo), enrichment factor (EF), degree of contamination (Cdeg), potential ecological risk (RI), and pollution load index (PLI). The heavy metals concentrations ranged from 4 to 61 mg/kg for As, 8-48 mg/kg for Cu, 0.01-0.06 mg/kg for Hg, 30-813 mg/kg for Ni, and 4-30 mg/kg for Pb. The mean As and Ni concentrations were much greater than Earth's crustal average, the world's mean values, and mean values from many other emerging countries. Igeo and EF values for As, Ni, and Pb indicate various degrees of contamination. Cdeg values show that 96% of the study area is affected to some degree by contamination. For RI values, 38% indicate ecological risks ranging from moderate to considerable degrees. PLI values show that 75% of the agricultural soils are moderately polluted. Spatial distribution maps of Cdeg, RI, and PLI show that the northeastern and southwestern parts of the study area have been polluted to different levels by As, Ni, and Pb. Industrial activities and excessive use of fertilizers, pesticides, fungicides, and herbicides were identified as major sources of heavy metals contamination in the agricultural soils of Usak.

Contamination by As, Hg, and Sb in a region with geogenic As anomaly and subsequent human health risk characterization.

Arsenic (As) is among the most harmful toxic elements to human health with severe carcinogenic and non-carcinogenic effects. The present study aims to (1) characterize a site with geogenic As anomaly (Emet basin) in Kutahya, Turkey via soil (urban, agriculture, forest; n = 53 total), water (n = 11), and agricultural product (n = 19) samples; and, (2) characterize human health risks for different receptors under specific exposure scenarios. Soil As levels were very high (range, 22.4-765 mg kg-1). Previous literature suggested some evidence of Sb and Hg combined with As in mineral forms in the region; the present study found elevated Sb (up to 76.0 mg kg-1) in two regions with very high As levels, but Hg concentrations were low in the region. Soils from urban/agricultural zones (representing anthropogenic impact) did not have statistically different As levels compared with forest soils (representing low/no human impact). As water concentrations were also very high (range, 14.0-729 µg L-1), however, uptake by agricultural products was low, mostly limited to wheat (up to 0.7 mg kg-1). Exposure assessment/risk characterization showed that non-carcinogenic risk following exposure to soils was very high for children (hazard index up to 37 under reasonable maximum exposure) as well as carcinogenic risk (probability up to 1.19E-3). The risk was even higher considering intake of water, and in this case, both for children and adults (HI, 4.0-66.6; cancer risk, 1.29E-4-1.84E-2). The potential adverse outcomes of the As anomaly in the region may be grave, thus further geochemical investigation of As speciation and mobile fractions as well as gastrointestinal As bioaccessibility supplementing probabilistic human health risk characterization are recommended.

Heavy metal contamination in soils around the Tunçbilek Thermal Power Plant (Kütahya, Turkey).

Tunçbilek, one of the major thermal power plants (TTPP) in Turkey running on coal, has capacity to generate 365 MW (per year) electricity. Fifty top soil samples were collected from a depth about 0-20 cm in the close vicinity of the TTPP from random points and at different distances. The samples were analyzed using ICP-MS for heavy metals. Heavy metal contents in soils around TTPP varied from 4.4 to 317.5 mg/kg for As, 0.03 to 0.26 mg/kg for Cd, 20.3 to 1028 mg/kg for Cr, 4.8 to 76.8 mg/kg for Cu, 0.09 to 9.3 mg/kg for Hg, 16.6 to 2385 mg/kg for Ni, 4.8 to 58.6 mg/kg for Pb, and 14.5 to 249.5 mg/kg for Zn. Geoaccumulation index (I geo) and enrichment factor (EF) have been calculated in order to evaluate heavy metal pollution in the soils. According to the I geo calculations, the surface soils around TTPP are contaminated by As, Hg, and Ni from uncontaminated to extremely contaminated. I geo values for Cr show practically uncontaminated to be heavily contaminated. The contamination of soil samples changes from practically uncontaminated to moderately contaminated degree for Pb and Zn. The soil samples were uncontaminated for Cd and Cu metals. The enrichment factors of As, Cr, Hg, and Ni in most of the sampling locations indicate significant to extremely high enrichment. The EF for Pb is also high and indicates moderate to very high enrichment of chromium in the soils. The average EF values for Cd, Cu, and Zn are showing moderate enrichment.

90-fs stretched-pulse ytterbium-doped double-clad fiber laser.

We report ultrashort, high-energy pulse generation from a side-pumped Yb-doped double-clad fiber laser. The laser is operating in the stretched-pulse regime. It directly generates 4.8-ps, 5-nJ pulses that are extracavity compressed to 90 fs.

Application of the two-dimensional fractional-order Fourier transformation to particle field digital holography.

We demonstrate that the fractional-order Fourier transformation is a suitable method to analyze the diffraction patterns of particle field holograms. This method permits reconstruction of in-line digital holograms beyond the Fraunhofer condition (d2/lambdaz approximately/= 10). We show that the diameter of spherical particles is measured with good accuracy. Simulation and experimental results are presented.

Characterization of diffraction patterns directly from in-line holograms with the fractional Fourier transform.

We show that the fractional Fourier transform is a suitable mechanism with which to analyze the diffraction patterns produced by a one-dimensional object because its intensity distribution is partially described by a linear chirp function. The three-dimensional location and the diameter of a fiber can be determined, provided that the optimal fractional order is selected. The effect of compaction of the intensity distribution in the fractional Fourier domain is discussed. A few experimental results are presented.

Evidence of Brillouin scattering in an ytterbium-doped double-clad fiber laser.

We have designed and performed an experiment that permitted direct observation of Brillouin backscattering in an Yb-doped double-clad fiber laser. Fifteen Brillouin-shifted frequencies were observed for the first time to our knowledge. We clearly demonstrate that stimulated Brillouin scattering is directly responsible for both fast transient dynamics of the laser and reduction of the laser's pulse width.