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In this work, the possibility of using niobium oxide recovered from tailings from the Penouta Sn–Nb–Ta deposit (located at the North of Spain) as starting material for growing microstructures is demonstrated. The properties of the starting material have been studied to understand its crystal structure, quality and purity. Recovered niobium oxide powders are mainly of TT-Nb 2 O 5. These powders have been used to grow Nb 22 O 54 microrods by an evaporation method in an argon atmosphere. Different characterization techniques (X-Ray diffraction, scanning electron microscopy, micro-Raman spectroscopy, luminescence) have been used to determine the properties of Nb 22 O 54 microrods, mainly focusing on the crystal quality and refractive index. The present study opens the way to the transformation of waste (mine tailings) into a material of high technological value as niobium oxide, and its reintroduction into the value chain for a wide range of applications, from coatings to batteries and supercapacitors. [ABSTRACT FROM AUTHOR]

In this paper, a climatological study focused on the analysis of atmospheric aerosols properties over Burjassot and Aras de los Olmos AERONET sites, located at Eastern Spain, is performed. Computed mean values for Aerosol Optical Depth (AOD 440), Ångström exponent (α 440 − 870) and columnar water vapor (w) in Burjassot (Aras de los Olmos) are 0.19 ± 0.08 (0.10 ± 0.02), 1.21 ± 0.16 (1.18 ± 0.25) and 1.87 ± 0.68 cm (0.94 ± 0.10 cm), respectively. From the monthly statistics of w and AOD , it is concluded that summer months are characterised by higher humidity and turbidity, being the latter favoured by particle stagnation, recirculation, secondary aerosol formation, hygroscopic processes and North African dust intrusions. Regarding the volume size distribution, well developed fine and coarse modes are found in summer. On the other hand, the spectral dependence of the asymmetry parameter (g) describes a decrease in λ up to 870 nm , and then a slight increase due to the influence of dust particles. The computed mean values for the asymmetry parameter (g 440) are 0.700 ± 0.013 (0.709 ± 0.016) for Burjassot (Aras de los Olmos). With respect to the Single Scattering Albedo (SSA) and the complex refractive index, an additional analysis using Level 1.5 data is performed, as relatively few data points pass the filters imposed by the Level 2.0 conditions. In the case of SSA, which is found to be larger in spring and summer months, the obtained mean annual values at 440 nm are 0.94 ± 0.03 (0.95 ± 0.03) for Burjassot (Aras de los Olmos). Finally, regarding the complex refractive index, the mean values of the real part (m 440) are 1.50 ± 0.03 (1.49 ± 0.03), and for the imaginary part (∣ k 440 ∣) are 0.007 ± 0.004 (0.004 ± 0.003) in Burjassot (Aras de los Olmos). The present study is complemented with three analyses based on the distinction between the different aerosol types. To begin with, these are classified according to their nature, being the most abundant continental clean aerosols. Next, Gobbi diagrams are plotted for both sites, depicting a clustered region of coarse aerosols, as well as particle growth traces. Finally, the different air masses affecting the measurement sites are studied, reaching to the conclusion that these originated in the European and the African continents are the most turbid ones. To conclude this study, a seasonal Mann-Kendall test is applied to AOD, α , w and SSA measurements in order to study possible trends. Hence, a statistically significant (> 80 %) decreasing trend in AOD is observed for most months; whereas α , w and SSA do not show statistically significant long-term trends, only for a few months of the year. • 20 (6) years AERONET data studied for Burjassot (Aras de los Olmos) in Eastern Spain. • Continental clean aerosols are dominant over Burjassot and Aras de los Olmos. • AOD, α and ω higher at Burjassot than Aras de los Olmos due to its urban character. • European and African air masses are responsible for high turbidity measurements. • AOD decreases with 80% confidence level; but α and SSA trends are not statistically significant. [ABSTRACT FROM AUTHOR]

Purpose: To investigate and evaluate the chromatic dispersion of various hydrogel and silicon hydrogel contact lens materials., Methods: Eighteen different soft contact lens materials with high and low water content in lens power of -1.00 DS were measured by one operator at temperature of 20 °C ± 0.5° soaked in ISO standard phosphate-buffered saline (PBS) and in their respective packaging solutions (PS). An analogue Abbe refractometer (Model Zuzi 320, AUXILAB, S.L., Navarra, Spain) was used for refractive index (RI) measurements at 5 different wavelengths. All contact lenses were presented in a random and masked order to the operator. The Bland-Altman method with 95 % limits of agreement (LoA) and coefficient of repeatability (CoR) was used to characterise the repeatability of refractive index measurements. The Abbe numbers for each material were calculated by entering the measured and interpolated refractive indices into the Abbe number equation. One-way ANOVA analysis was used to test if there were significant differences between the 5 different wavelengths (470 nm-680 nm) within each material. An unpaired t-test was used to determine if there were differences in refractive index or dispersion between packaging solution and PBS results., Results: Nelfilcon A (Dailies Aqua Comfort Plus) soaked in PS showed the best repeatability of all 18 examined soft contact lenses across all wavelengths with an average refractive index of 1.3848 for all 6 contact lenses with a standard deviation of 0.00064. The 95 % limits of agreement were between 1.3835 and 1.3860. The mean coefficient of repeatability for nelfilcon A was 0.00125. For contact lenses soaked in ISO Standard PBS comfilcon A (Biofinity) had the best repeatability. The average refractive index of all 6 contact lenses was 1.4041 with a standard deviation of 0.00031 and a coefficient of repeatability of 0.00060. The 95 % limits of agreement were between 1.4035 and 1.4047. The analysis with One-way ANOVA with multiple comparisons involving Holm-Sidak post-hoc, showed that there are significant differences (p < 0.001, F ratio  = 376.2 between wavelengths and F ratio  = 1559 between different refractive indices) in the refractive index of most common lens materials across the visible wavelength range. Based on unpaired t-test, there is no significant difference (p > 0.05) in the Abbe numbers of the tested lens materials whether they have been placed in the packaging solution or in standard PBS (p > 0.05, 95 % CI = -4.8070 to 5.8680, t = 0.2054). The Abbe numbers for the calculated contact lenses soaked in PS ranged between 43.7 and 89.9. For contact lenses stored in PBS the range was between 46.3 and 81.6., Conclusion: There is a good repeatability between repeated RI measurements taken from the same lens and from the same material. The significant differences between the refractive indices across the 5 different wavelengths showed the presence of chromatic dispersion in the 18 evaluated soft contact lens materials. Furthermore, it could be shown that there is no significant difference in dispersion whether the contact lenses are soaked in standard PBS or in their respective packaging solutions. With no other published data available as a reference, absolute accuracy of the calculated Abbe numbers remains to be confirmed, however, this study did confirm that significant chromatic dispersion exists in soft contact lens materials., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.)

In this study, an indoor/outdoor monitoring program was carried out in a gymnasium at the University of Leon, Spain. The main goal was a characterization of aerosol size distributions in a university gymnasium under different conditions and sports activities (with and without magnesia alba) and the study of the mass fraction deposited in each of the parts of the respiratory tract. The aerosol particles were measured in 31 discrete channels (size ranges) using a laser spectrometer probe. Aerosol size distributions were studied under different conditions: i) before sports activities, ii) activities without using magnesia alba, iii) activities using magnesia alba, iv) cleaning procedures, and v) outdoors. The aerosol refractive index and density indoors were estimated from the aerosol composition: 1.577–0.003i and 2.055 g cm − 3 , respectively. Using the estimated density, the mass concentration was calculated, and the evolution of PM 1 , PM 2.5 and PM 10 for different activities was assessed. The quality of the air in the gymnasium was strongly influenced by the use of magnesia alba (MgCO 3 ) and the number of gymnasts who were training. Due to the climbing chalk and the constant process of resuspension, average PM 10 concentrations of over 440 μg m − 3 were reached. The maximum daily concentrations ranged from 500 to 900 μg m − 3 . Particle size determines the place in the respiratory tract where the deposition occurs. For this reason, the inhalable, thoracic, tracheobronchial and respirable fractions were assessed for healthy adults and high risk people, according to international standards. The estimations show that, for healthy adults, up to 300 μg m − 3 can be retained by the trachea and bronchi, and 130 μg m − 3 may reach the alveolar region. The different physical activities and the attendance rates in the sports facility have a significant influence on the concentration and size distributions observed. [ABSTRACT FROM AUTHOR]

In this work, a novel technique is used to estimate the aerosol complex index of refraction of in situ collected samples. Samples of atmospheric particulate matter were collected in El Arenosillo, southern Spain, on polycarbonate filters during summer 2004 as part of an aerosol characterization campaign. These samples were analyzed for the volumetric absorption coefficient in the 320–800 nm spectral region and an estimation of the effective imaginary refractive index was made. The values of the imaginary part of the complex refractive index ranged between 0.0009–0.0215 at 800 nm and 0.0015–0.0114 at 320 nm. Little dependence on the wavelength was observed. Several intense and long lasting desert outbreaks were registered during the campaign and the complex refractive index almost doubles its value during these dust events. Finally, we present a comparison of data obtained in situ with columnar data obtained from the AERONET network. A correlation factor of 0.64 was obtained between both data, which gives an idea of how accurately the in situ ground data represent the total column. [Copyright &y& Elsevier]

Purpose: To validate clinically in a normal healthy population an algorithm to correct the error in the keratometric estimation of corneal power based on the use of a variable keratometric index of refraction (n k). Setting: Medimar International Hospital (Oftalmar) and University of Alicante, Alicante, Spain. Design: Case series. Methods: Corneal power was measured with a Scheimpflug photography–based system (Pentacam software version 1.14r01) in healthy eyes with no previous ocular surgery. In all cases, keratometric corneal power was also estimated using an adjusted value of n k that is dependent on the anterior corneal radius (r 1c) as follows: n kadj = −0.0064286 r 1c +1.37688. Agreement between the Gaussian (P c Gauss) and adjusted keratometric (P kadj) corneal power values was evaluated. Results: The study evaluated 92 eyes (92 patients; age range 15 to 64 years). The mean difference between P c Gauss and P kadj was −0.02 diopter (D) ± 0.22 (SD) (P=.43). A very strong, statistically significant correlation was found between both corneal powers (r = .994, P<.01). The range of agreement between P c Gauss and P kadj was 0.44 D, with limits of agreement of −0.46 and +0.42 D. In addition, a very strong, statistically significant correlation of the difference between P c Gauss and P kadj and the posterior corneal radius was found (r = 0.96, P<.01). Conclusion: The imprecision in the calculation of corneal power using keratometric estimation can be minimized in clinical practice by using a variable keratometric index that depends on the radius of the anterior corneal surface. Financial Disclosure: No author has a financial or proprietary interest in any material or method mentioned. [ABSTRACT FROM AUTHOR]

A detailed analysis of the columnar optical aerosol properties has been carried out for data collected during the “El Arenosillo 2004 summer campaign”. These data are derived from a Cimel sun-photometer, as part of the PHOTONS-AERONET network at the El Arenosillo site in south-western Spain, over the period 1 June to 31 October 2004. Version 1 AERONET inversion products are used in the analysis. The aim of this campaign was to obtain a more complete set of data on aerosol particle microphysical, optical/radiative, absorbing and chemical properties for use in closure studies. In this paper we focus on the characterization of the aerosol optical depth (AOD)–alpha coefficients, and the particle size distribution together with their associated microphysical parameters, such as volume concentration, effective radius, etc., in order to define the features and ranges of these physical parameters associated with both fine and coarse particle modes. The requirement of high AOD values for using the inversion technique puts significant constraints on the estimation of the single scattering albedo (SSA) and refractive index, and thus requires great care in the analysis. As a result, only the characterizations of these parameters for desert dust events are considered reliable. Moreover, summer 2004 had the most frequent desert dust intrusions, including the most intense event (22–28 July and 31 July–2 August) ever recorded at the El Arenosillo site since the start of the measurements in February 2000. We summarize the results for the intensive summer campaign in terms of the range of values of the physical and optical parameters of the different aerosol types present in this area of Spain. [Copyright &y& Elsevier]

Samples from two strong homogeneous dust plumes from the Saharan desert reaching Izaña (Tenerife, Spain) in July and August 2005 were taken with a miniature impactor system and filter samplers. Size, aspect ratio and chemical composition of more than 22,000 individual particles were studied by scanning electron microscopy. The mineralogical phase composition of about 200 particles was investigated by transmission electron microscopy. In addition, the aerosol size distribution was measured with an optical particle spectrometer. In all samples, the aerosol was dominated by mineral dust with an average composition (by volume) of 64% silicates, 6% quartz, 5% calcium-rich particles, 14% sulfates, 1% hematite, 1% soot and 9% other carbonaceous material. Sulfate was found predominantly as coating on other particles with an average thickness of approximately 60nm. The aerosol calcium content is correlated with the calcite concentrations of soils in the source region, highest values were observed for northern and central Algeria and Morocco. The average aspect ratio of the particles was 1.64. The distributions of the aspect ratios are parameterized by log-normal functions for modeling purpose. Single-scattering albedo (0.95) and asymmetry factor (0.74–0.81) was measured by polar aerosol photometry on filter samples using a light source resembling the solar spectrum. The apparent soot content of the sample (1vol%) was determined by the same technique. From the mineralogical data, an average complex refractive index of 1.59–9×10−3i for visible light was derived. The imaginary part of the complex refractive index decreases with increasing particle size from −2.5×10−2i to <−10−3i, reflecting the decreasing hematite and soot contents. The imaginary part derived from optical measurements was −7×10−3i. [Copyright &y& Elsevier]

Lentils (Lens culinaris spp.) are an important food consumed worldwide given their high protein, fiber, mineral, and phytochemical contents, and can be used as a potential source of good nutrition for many people. With the purpose of valuing the Pardina variety, the quality brand from a protected geographical indication "Lenteja de Tierra de Campos", a full assessment of the nutritional, chemical, and antioxidant properties of 34 samples from this variety was carried out. Besides its actual rich nutritional profile, three phenolic compounds by high performance liquid chromatography equipped with photodiode array detection-mass (HPLC-DAD-ESI/MS) were identified (kaempferol derivatives) with slight differences between them in all extracts. Sucrose by high-performance liquid chromatography with a refraction index detector (HPLC-RI) and citric acid by ultra-fast liquid chromatography coupled with a photodiode array detector (UFLC-PDA) were the major identified sugar and organic acid components, respectively, as well as α-tocopherol and γ-tocopherol isoforms (HPLC-fluorescence). Additionally, all the extracts presented excellent antioxidant activity by the oxidative hemolysis inhibition assay (OxHLIA/TBARS). Briefly, Pardina lentils from this quality brand are a good source of nutritional and chemical components and should therefore be included in a balanced diet. [ABSTRACT FROM AUTHOR]

• Tools for accurate detection of illegal discharges of cheese whey in watercourses. • Algorithms to quantify cheese whey concentration in rivers and reservoirs. • Inexpensive and rapid technique to easily monitor in waterways. • Method to prevent chemical and biological hazards for aquatic ecosystems. A computerized approach to quickly, easily, and efficiently detect discharged sewage of the cheese sector into rivers or reservoirs has been presented in this work. It is based on developing and/or training linear regression, linear multiple regression, and multilayer perceptron-based models using the data obtained from measuring different contaminated waters with a portable digital refractometer. This equipment measures the refractive index, Brix degrees, and salinity of aqueous samples. To carry it out, 451 samples were made by mixing five different waters with cheese whey from the Spanish "Fábrica de quesos de Villalón de Campos S.L.". The water samples used were distilled water and four non-drinkable waters taken from four different Spanish locations (the Valmayor Reservoir, the Mari Pascuala Lagoon, the Manzanares River and the Guadarrama River). The lowest mean absolute percentage error (0.79%) was achieved using three independent variables and a multilayer perceptron-based model. The validation of this approach has been done in two ways: k-fold cross-validation and internal validation. The outcome of this research is a new method for a fast detection of waste spillages into rivers and reservoirs. [ABSTRACT FROM AUTHOR]