2nd Order Research Articles

Electron series resonance excited in the 27.12 MHz magnetron sputtering discharge

Abstract The electron series resonance (ESR) excited in the 27.12 MHz magnetron sputtering discharge was investigated. By analyzing the discharge impedances, the imaginary part of impedance was found to undergo a transition from capacitive to inductive on varying RF power, and the conditions for ESR excited was satisfied at the 27.12 MHz magnetron sputtering. By analyzing the discharge current and its higher order harmonics, the near-sinusoidal current waveform and the weak 2nd order harmonic were obtained, showing a weak nonlinear effect of RF current. However, for the magnetron sputtering discharge, the non-uniform magnetic field has a significant effect on the sheath width and the transverse current, making the sheath thinner and the transverse current smaller. As a result, the small capacitive reactance was obtained and the inductive reactance was easily cancelled. Therefore, the electron series resonance excited in the 27.12 MHz magnetron sputtering was caused together by the strong effect of non-uniform magnetic field and the weak 2nd (H2) order current harmonic. By estimating the ESR frequency res,B, the 2nd order current harmonic (54.24 Hz) was found to be responsible for the ESR excitation.

Increase of Reliability of Anomalies Detection on Images at Formation of Their Feature Vectors in Wavelet Bases

The method of detection of life rafts and lifeboats in the water area of seas and oceans after shipwrecks based on the recognition of anomalies in the processed images, which increases the probability of recognition of monitoring objects, is proposed. The approach to solving such a problem is substantiated. The formulation of the problem of object recognition from the perspective of binary classification in the detection of anomalies is presented. The analytical expression for the decision-making algorithm is obtained. The possibility of formalization of image matrices in the form of histograms of color (brightness) intensity distributions is considered. The contrast of the feature space on their basis is estimated. It is suggested that the contrast of feature spaces be increased due to the secondary processing of histograms of distributions in the basis of multiple-scale wavelet decomposition. The possibility of realization of wavelet transformations on the basis of Haar functions and Gauss wavelets of the 1st and 2nd orders is considered. The mechanism of formation of secondary feature vectors from three-dimensional wavelet transforms by averaging their coefficients along the time shift axis is substantiated. It is shown that at the same dimensionality of histograms of brightness distribution with newly formed feature vectors, the latter provide higher contrast of feature spaces. It is recommended to use a Gaussian wavelet of the 2nd order for the formalization of images in jpeg format, which provides, other things being equal, a greater magnitude of differences for images containing anomalies. An approach to probabilistic evaluation of the algorithm for automatic image recognition is developed. The analytical expression is obtained and its constituent elements are justified. Graphical dependences of the probability of correct detection (recognition) of anomalies, depending on the size in relation to the total area of the frame and the dispersion of the underlying background are given. The results of the experiment on image recognition with a lifeboat in the ocean water area are presented. The directions of further research are defined.

Second Harmonic Generation of High Power Cosh-Gaussian Beam in Thermal Quantum Plasma: Effect of Relativistic and Ponderomotive Nonlinearity

Second harmonic generation (SHG) of high power Cosh-Gaussian(ChG) beam in thermal quantum plasma (TQP) is explored in current investigation. Relativistic and ponderomotive nonlinearities are taken together in present investigation. Combination of relativistic-ponderomotive nonlinearities causes modification in electron mass, thereby producing density gradients inside plasma. This further produces self-focusing of main beam. The well-known WKB and paraxial approaches are used for solving main beam’s wave equation and to obtain 2nd order ordinary differential equation (ODE). There is generation of electron plasma wave (EPW) due to these density gradients. Excited EPW interacts with main beam to generate 2nd harmonics in plasma. Effects of combined relativistic-ponderomotive nonlinearities and established laser - plasma parameters on beam’s waist and SHG yield are studied in present study.

Impact of High-Power Cosh-Gaussian Beam on Second Harmonic Generation in Collisionless Magnetoplasma

The impact of high power Cosh-Gaussian (ChG) beam on Second harmonic generation (SHG) in Collisionless magnetoplasma is explored in present work. Whenever the input beam propagates along external magnetic magnetic field direction, then there are two propagation modes viz. extraordinary mode and ordinary mode. The modification in magnetic field strength causes redistribution of carriers. The density gradients get established in plasma in a normal direction to input wave due to ponderomotive force. Further, there is production of electron plasma wave (EPW) at input wave frequency due to density gradients. EPW nonlinearly interacts with pump wave causing generation of 2nd harmonics. The 2nd order differential equation (ODE) for beam width of and efficiency of 2nd harmonics are derived through well-known paraxial theory approach. RK4 method is employed for carrying out numerical calculation of nonlinear ODE along with efficiency of 2nd harmonics. Impact of change in selective laserplasma parameters and externally applied magnetic field on beam waist of input wave and efficiency of SHG are also explored.

Impact of modal gain and waveguide design on two-state lasing in quantum well-dot lasers.

We study the current-controlled lasing switching from the ground state (GS) to the excited state (ES) transition in broad-area (stripe width 100 µm) InGaAs/GaAs quantum well-dot (QWD) and quantum well (QW) lasers. In the lasers with one QWD layer and a 0.45 µm-thick GaAs waveguide, pure GS lasing takes place up to an injection current as high as 8 A (40 kA/cm2). In contrast, in QW lasers with a similar design, ES lasing emerges already at 3 A (15 kA/cm2). The ES lasing in the QWD lasers is observed only in the devices with a waveguide thickness of 0.78 µm that supports a 2nd order transverse mode at the wavelength of the ES transition. Increasing the modal gain in the lasers with 0.78 µm-thick waveguide by using two QWD layers in the active region suppresses the ES lasing.

Novel method in mice to evaluate left atrial (LA) systolic contribution to left ventricular volume (LV) using pressure-volume (PV) loops

Abstract Background LA myopathy is a critically important non-LV contributor to the progression of HFpEF (heart failure with preserved ejection fraction) in patients and is associated with a severe phenotype, leading to impaired cardiac output reserve and reduced exercise capacity. In normal humans LA systole contributes ~20% of total LV filling, but with HFpEF, this contribution decreases to <16% with a greater reliance on this contribution to LV filling. Purpose We sought to investigate LA function as a critical component of cardiac function analysis by utilizing the LV pressure signal to identify and quantify the contribution of volume during LA systole to the total LV volume in mice with HFpEF. Methods Hypertension (HTN)-associated HFpEF C57BL/6J mice were subjected to chronic aldosterone infusion and 1% NaCl for 4 weeks (SAUNA model). Obesity after a high fat diet (HFD: 60% fat diet) for 16 weeks followed by the SAUNA protocol, induced HTN and obesity associated HFpEF. Blood pressure was monitored weekly. Mice were anesthetized with isoflurane, intubated, chest opened to expose the heart and allow placement of a PV catheter (Transonic) which was introduced into the LV via apical stab with a 27G needle. Calibration of the PV catheter was performed according to the manufacturer’s instructions. Atrial systole was identified using 2nd order derivative of the LV pressure signal. Contribution of LA systole was calculated using volume at the beginning of LA systole identified by the 2nd order derivative of the LV pressure signal and subtracting from the LV end diastolic volume. The % of LA systole contribution was calculated as a % of the total LV stroke volume. Data was analyzed with LabChart pro software (AD Instruments). Results SAUNA mice had normal LVEF, moderate HTN and lung congestion. PV relationships demonstrated Tau was impaired in HFpEF vs. control mice (14±1 vs. 10±0.5 ms) with a shift of the PV loop to the left (Fig. A.) In control mice, the atrial systole contributed 39± 4% to LV volume and was impaired in HFpEF mice 20± 3% a 1.95-fold reduction (P<0.01). Importantly atrial systole contribution was increased in obese mice 53±5 %. However, the combination of obesity and HTN, both common comorbidities in HFpEF, resulted in a reduced LA systole contribution by 1.43-fold to 37± 9%, (P<0.005; Fig B). Conclusion A novel method of % atrial systole from LV PV loop using 2nd order derivative to quantify the volume contribution of atrial systole to total LV stroke volume was identified in mice. LA dysfunction was present in murine HTN-associated HFpEF with/without obesity.

Discretization of Fractional Fully Nonlinear Equations by Powers of Discrete Laplacians

AbstractWe study discretizations of fractional fully nonlinear equations by powers of discrete Laplacians. Our problems are parabolic and of order $$\sigma \in (0,2)$$ σ ∈ ( 0 , 2 ) since they involve fractional Laplace operators $$(-\Delta )^{\sigma /2}$$ ( - Δ ) σ / 2 . They arise e.g. in control and game theory as dynamic programming equations – HJB and Isaacs equation – and solutions are non-smooth in general and should be interpreted as viscosity solutions. Our approximations are realized as finite-difference quadrature approximations and are 2nd order accurate for all values of $$\sigma $$ σ . The accuracy of previous approximations of fractional fully nonlinear equations depend on $$\sigma $$ σ and are worse when $$\sigma $$ σ is close to 2. We show that the schemes are monotone, consistent, $$L^\infty $$ L ∞ -stable, and convergent using a priori estimates, viscosity solutions theory, and the method of half-relaxed limits. We also prove a second order error bound for smooth solutions and present many numerical examples.

State of oral health in the Portuguese population and associated psychological and social aspects

Abstract Background Oral diseases are a global public health challenge and remain among the most prevalent non-communicable diseases. This study aims to characterize the self-assessment of oral health state, degree of edentulism, oral rehabilitation and the quality of life, namely chewing capacity, and the associated psychological and social aspects in the Portuguese Population. Methods Data were collected by telefone survey, on the 2nd half of 2018 and 1st half of 2019, using the Portuguese population representative, ECOS panel. Descriptive statistics, as well as prevalence estimates, were obtained with weighting for age, sex, region and sample design, for 95% confidence intervals. The modified F-statistic, a variant of the 2nd order Rao-Scott chi-square adjustment, was used to test the bivariate analyses. Results For 53% of the population, the health status of the mouth was perceived as Good or Very Good, for 37% Fair and, in 11% of cases as Bad or Very Bad. It is estimated that around 76% of the population has good oral hygiene habits, approximately 26% have all of their teeth and 8% the total absence of teeth. It is estimated that only around half (49%) underwent rehabilitation using, in the vast majority of cases (78,5%), removable prostheses. It is estimated that 32% of its users have difficulty chewing hard foods and, of these, around 20% have great difficulty or are unable to chew at all. Psychological discomfort due to oral health was higher in the Portuguese population when compared to the European population (17% vs 7 %), psychological limitations due to the appearance of teeth or dentures were equally higher (7% vs 4%), as were social limitations (8,8% vs 4%). Conclusions The oral health panorama in Portugal remains bleak, so strengthening the application and deepening of the national oral health promotion program should constitute a priority aspect in the development of public policies in the country Key messages • Integrating oral health into general health promotion strategies and assessing oral health needs to include psychological and social aspects in the Portuguese Population. • Strengthening the strategies that have been developed in the context of health promotion, prevention and early treatment of oral diseases in Portugal.

The The Impact of Entrepreneurial Orientation and Social Capital on Culinary Business Performance in Surabaya with the Knowledge Creation Process as a Mediating Variable

Purpose: This study examines factors influencing culinary business performance in Surabaya, focusing on the relationship between entrepreneurial orientation, social capital, and business performance, with knowledge creation as a mediating variable. Method: Data were collected from 345 micro, small, and medium-scale culinary entrepreneurs in Surabaya. The analysis used Structural Equation Modeling (SEM) with 2nd order Confirmatory Factor Analysis (CFA) via AMOS 22 software Result: Entrepreneurial orientation and social capital significantly affect knowledge creation and business performance. The SECI-based knowledge creation process positively impacts business performance and partially mediates the relationship between entrepreneurial orientation and business performance.

A Particle Method for the Multispecies Landau Equation.

The multispecies Landau collision operator describes the two-particle, small scattering angle or grazing collisions in a plasma made up of different species of particles such as electrons and ions. Recently, a structure preserving deterministic particle method (Carrillo et al. in J. Comput. Phys. 7:100066, 2020) has been developed for the single species spatially homogeneous Landau equation. This method relies on a regularization of the Landau collision operator so that an approximate solution, which is a linear combination of Dirac delta distributions, is well-defined. Based on a weak form of the regularized Landau equation, the time dependent locations of the Dirac delta functions satisfy a system of ordinary differential equations. In this work, we extend this particle method to the multispecies case, and examine its conservation of mass, momentum, and energy, and decay of entropy properties. We show that the equilibrium distribution of the regularized multispecies Landau equation is a Maxwellian distribution, and state a critical condition on the regularization parameters that guarantees a species independent equilibrium temperature. A convergence study comparing an exact multispecies Bobylev-Krook-Wu (BKW) solution to the particle solution shows approximately 2nd order accuracy. Important physical properties such as conservation, decay of entropy, and equilibrium distribution of the particle method are demonstrated with several numerical examples.

Biosynthesis of calcium oxide nanoparticles by employing Mulberry (Morus nigra) leaf extract as an efficient source for Rhodamine B remediation

Green processes for synthesizing nanocomposites are a hot area of research today as traditional processes are expensive, inefficient, harmful for synthesizing organic and inorganic molecules, and unsuitable for large-scale operations. The present study investigates the capacity of green synthesized Calcium oxide nanoparticles (CaO NPs) for efficiently removing Rhodamine B. Chemical reduction was replaced with Mulberry (Morus nigera) leaf extract as an environmentally friendly reaction mechanism. CaO NPs are characterized by various analytical techniques including EDX, BET, SEM, FTIR, TGA, Zeta Potential, Point of Zero Charge (PZC), and XRD. Maximum adsorption of Rhodamine B by CaO NPs is revealed at an initial concentration of Rhodamine B of 80 ppm, a temperature of 343 K, and contact time of 60 min, 0.4 g of adsorbent at a pH value of 7. Maximum removal of Rhodamine B by CaO NPs was found to be 98.2% which is promising with this small amount of adsorbent (0.4 g). Diverse Kinetic and adsorption isotherms are employed in this study to determine the requirement and significance of the adsorption process. Various adsorption isotherms such as Freundlich, Temkin, Dubinin–Radushkevich (D–R), and Langmuir models have been employed. Among the kinetic adsorption isotherms Elovich, Intraparticle kinetic model, pseudo 1st order, and pseudo 2nd order models were applied. The current study investigates the thorough understanding of the Rhodamine B adsorption process including the mechanism of adsorption using condition optimization, characterization, and model applications. The proposed adsorbent can be employed for the green removal of Rhodamine B from wastewater of industry with maximum efficiency and favorable regeneration properties.

Fishy Forensics: FT-NIR and Machine Learning based authentication of Mediterranean Anchovies (Engraulis encrasicolus)

Seafood authentication and traceability is a challenging issue owing to its complex supply chain and fishing in international waters. NIR spectroscopy has been successfully used to authenticate food of animal and plant origin. In this study, FT-NIR was used to discriminate between Mediterranean anchovies (Engraulis encrasicolus) fished from Adriatic, Balearic, and Tyrrhenian Sea. The spectra were prepared using the standard normal variate (SNV) and the Savitzky-Golay 1st derivative, 2nd order (SG), as well as both together. The model was built, after outlier removal, with linear-support vector machine (L-SVM), polynomial-SVM (P-SVM), k-nearest neighbor (k-NN) and Random Forest (RF). Spectral preprocessing improved model classification accuracy for all algorithms. The data could not be put into groups by linear algorithms like L-SVM and k-NN because the NIR spectra were not linear and had many columns. Non-linear algorithms, P-SVM and RF when coupled with SG+SNV, successfully produced models with maximum robustness. P-SVM and RF models had 100% accuracy in training set and 95.7% and 95.5% accuracy in testing set, respectively and 95.2 and 95.1 accuracy in cross-validation set.

Kinetic model of thermal decomposition of nitric acid solutions of hydrazine nitrate

The kinetic parameters of thermal decomposition of an aqueous solution containing 0.029 mass fractions of hydrazine nitrate and 0.44 mass fractions of nitric acid have been determined: onset temperature and specific thermal effect of exothermic reactions, activation energy, pre-exponential factor, reaction rate and order. Based on the data obtained, a mathematical model of thermal decomposition of nitric acid solutions of hydrazine nitrate has been proposed. It has been found that thermolysis of the solution has a multi-stage nature and can be described by a system of 5 equations of 1st and 2nd order. A comparison of two approaches to creating a mathematical model has been carried out: based on adiabatic calorimetry and differential scanning calorimetry data.

Extraction of Anacardium occidentale: a kinetic, thermodynamic, phytochemical identification, and antibacterial study

Cashew tree biomass, Anacardium occidentale, represents an underutilized part of the plant and could have great potential for application in several areas, such as bioengineering, food science, and chemical. The stirred bed process was optimized to produce extracts from Anacardium occidentale stem bark (SBAo) and leaves (LAo) for bactericide purposes. Variables as alcohol content, stirring speed (SS), particle size (PS), solid-to-solvent ratio (S/S), temperature, and extraction time were evaluated. Subsequently, kinetic, thermodynamic and diffusivity fittings of the data were performed using different nonlinear models (Peleg, 2nd order, Elovich, power law, and Fick’s 2nd law) applied to the yield curves. Extracts were characterized by Fourier-transform infrared (FTIR) spectroscopy, total phenolic content (TPC), total flavonoid content (TFC), trolox equivalent antioxidant capacity (TEAC), and ultra-high resolution mass spectrometry (UHRMS) techniques for qualitative and quantitative determination of the phytochemicals. The optimized operating conditions obtained were ethanol in solvent at 70%, PS < 45 μm, 1200 rpm SS, 1/10 S/S ratio, and extraction time of 1 h at 50 ºC. The 2nd order kinetic model was the one that presented the best fits: SBAo (R2 > 0.9893 and RMSE < 3.4293) and LAo (R2 > 0.9985 and RMSE < 3.1117). Both A. occidentale extracts showed high levels of polyphenols and flavonoids, such as anacardic acid. Finally, the optimized extracts showed antibacterial susceptibility, with larger halos against S. aureus, 0.88± 0.07 mm (SBAo) and 0.45 ± 0.03 mm (LAo), in relation to E. coli, 0.80 ± 0.10 mm (SBAo) and 0.69 ± 0.08 mm (LAo).

Synergistic degradation of toxic azo dyes using Mn-CuO@Biochar: An efficient adsorptive and photocatalytic approach for wastewater treatment

Congo red (CR) and Eriochrome Black T (EBT) is a toxic azo dye with a complex structure which represents a serious Ecotoxicological hazards for aquatic bodies. This research investigates the synergistic effects of Corn plants biochar and manganese (Mn)-composited copper oxide (CuO) in the adsorptive and photocatalytic degradation of toxic anionic dyes i.e. CR and EBT. The acquired materials were characterized by FTIR, XRD, SEM-EDX, XPS, TEM, BET, ZP, and pHZc test. The experiment demonstrated that Mn-CuO@BC composite exhibited a remarkable adsorption of ∼ 98 % and ∼ 95 % and photocatalytic degradation of 92 % and 88 % for CR and EBT respectively. It was further found that coupling of the H2O2 with Mn-CuO@BC enhances the photocatalytic efficiency of catalyst for CR and EBT i.e. upto ∼ 98 % and 96 % respectively possibly owing to the efficient ●OH radical. Adsorption kinetics followed a pseudo 2nd order model, indicating predominant chemisorption, and adsorption isotherms fit well with the Langmuir model. Further, toxicity degradation products of EBT were examined through ECOSAR indicated a reduced ecological impact. In general, this work highlight the dual functional advantages of the Mn-CuO@BC composite, providing an efficient and versatile approach for wastewater treatment involving complex dye pollutants.

Green synthesis of ZnO/Fe3O4 nanoparticles with nigella sativa extract: Efficient degradation of methylene blue and antimicrobial properties

Zinc oxide (ZnO), iron oxide (Fe3O4) NPs, and ZnO/Fe3O4 nanocomposites (NCs) were synthesized using Nigella sativa (NS) seed extracts. These nanomaterials (NMs) were characterized by multiple analytical techniques like UV-visible spectrophotometers, FTIR spectroscopy, SEM, and XRD spectroscopy. The UV-visible spectrum showed 364 nm, 330 nm, and 331nm for ZnO NPs, Fe3O4 NPs, and ZnO/Fe3O4 NCs, respectively. Moreover, it was confirmed when the samples were run through FTIR techniques, and it was observed that the availability of bioactive functional groups was involved in the decline of bulk compounds to NPs. XRD showed their average nanoparticle size based on applying the formula of full width at half maximum (FWHM) for ZnO NPs, Fe3O4 NPs, and ZnO/Fe3O4 NCs at 29.52 nm, 22.08 nm, and 12.82 nm, respectively. In this study, the reduction of Methylene Blue (MB) dye was done by NPs and NCs, and their catalytic activities were investigated by a UV-visible spectrophotometer. MB dye showed the maximum absorption peak at 664 nm, and the reaction of MB was reduced using synthesized products with an accompanying color change reaction from blue to colorless within 60 min at 84%, 86%, and 99.5% degradation for ZnO NPs, Fe3O4 NPs, and ZnO/Fe3O4 NCs with rate constants of 0.00035, 0.00065, and 0.0015 Lmol-1S-1. The 2nd order rate constant was observed in this study. The agar disc diffusion method was used to investigate the potential antibacterial activity of synthesized NPs and NCs. This study is best suited for Gram-positive bacteria. NS seed extract-based synthesis of NCs could be an excellent catalyst and biological application for environmental pollution.

Hydrothermally synthesized Sr-doped In2S3 microspheres for efficient degradation of noxious RhB pollutants in visible light exposure

A series of SrxIn2-xS3 (x = 0, 2, 4, 6 and 8 mol%) microspheres have been prepared at 160°C using hydrothermal approach and examined the impact of Sr doping on its structural, morphological, optical and photocatalytic properties. Structural properties have been investigated using X-ray diffraction (XRD) with Rietveld refinement. Morphology and elemental composition have been analysed using Field emission scanning electron microscopy (FESEM) and Energy dispersive X-ray Spectroscopy (EDX), respectively. Optical band gap energy (Eg) has been determined using Diffuse reflectance Spectroscopy (DRS) and found to range between 2.15 eV to 2.07 eV. Photoluminescence (PL) emission spectra confirm a decrease in charge carrier recombination rate with Sr doping. The negative surface potential has been assessed by the Zeta analyzer, which indicates its suitability for the degradation of cationic dyes such as Rhodamine-B (RhB). Among the SrxIn2-xS3 microspheres, Sr0.04In1.96S3 demonstrated highest photocatalytic efficiency ∼98 % degradation of RhB pollutant (10 ppm) in 240 min. using 10 mg of catalyst per 100 ml. The adsorption kinetics in the presently studied samples obeys the pseudo 2nd order kinetic model. This study highlights the significant impact of Sr doping on the photocatalytic efficiency of SrxIn2-xS3 microspheres, offering promising applications in removal of RhB dye.

Gyrotactic micro-organism dusty fluid flow over an extended surface

The conventional magnetohydrodynamics (MHD) equations are modeled for the dusty fluid flow past a stretching sheet embedded in a porous medium. These equations are coupled with motile microorganisms, temperature and concentration equations for both fluid and dust particles dynamical equations. The two-phase dusty fluid flow is subjected to magnetic effect, porosity factor, 2nd order chemical reaction, Brownian diffusion, thermophoretic effect and Arrhenius activation energy. An appropriate transformation is used to reset the system of partial differential equations (PDEs) into non-linear system of ODEs (ordinary differential equations). The flow equations are numerically solved by using the parametric continuation method (PCM). For validity of the applied methodology, the results are compared using numerical and graphical results of Matlab built-in package “BVP4c”. Both results show accuracy up to four decimal places. Furthermore, from graphical results, it can be noticed that the fluid particles interaction parameter causes an attractive force among fluid particles which prevents the dust particles phase flow. This technique can be used for biological separations, filters, fluid dust separators and crude oil purification.

Effectiveness of magnetite nanoparticles for the removal of DNA of multidrug-resistant Escherichia coli from municipal wastewater.

Water is an important component of life and plays a vital role in human and animal lives, and because of these essential roles of water to life, access to quality water and in adequate quantity becomes imperative. Subsequently, water/wastewater systems have become established as reservoirs of antimicrobial resistance determinants in the environment. In this study, we carried out the synthesis and characterization of magnetite nanoparticles for use in the removal of genomic DNA of antibiotic resistant Escherichia coli isolate in aqueous system. The synthesis of this nanoparticle was achieved by using precipitation method and characterization of the material was conducted by using Fourier transform infrared spectroscopy (FTIR), scanning electron spectroscopy (SEM), electron diffraction spectroscopy (EDS), and vibrating sample magnetometry (VSM). The SEM analysis revealed that this material is spherical in shape, while the FTIR spectra revealed Fe-O vibrational band at ~ 450cm-1 confirming the success of the synthesis of this material. The magnetite nanomaterial showed efficiency for the removal of the bacterial DNA from water with a maximum removal capacity of 45.5ngg-1. The effect of pH (qe max = 55ngg-1 @ pH = 10), time (qt max @ 180min), DNA concentration (DNA concentration of 185ng/mL, qe max = 45.5ngg-1), and adsorbent weight (% adsorption max = 61.65% @ 0.025g) suggest that adsorption conditions influence the removal of DNA by this material. In addition, kinetic study shows that the removal of bacterial DNA obeyed pseudo 2nd order indicating that adsorption process was achieved by bimolecular interaction between magnetite and antibiotics resistant bacterial DNA. We conclude that magnetite nanoparticle appears to be a potential candidate for the removal of nucleic acids and antimicrobial resistance determinants in water/wastewater treatment.

Investigation of new analysis methods for simultaneous and rapid identification of five different microplastics using ATR-FTIR spectroscopy and chemometrics

Microplastic (MP) pollution in water has become one of the most important global problems of our time. The development of appropriate and rapid analysis techniques is of great importance at the beginning of the studies aimed at solving this problem. In the presented study, in order to perform the qualitative and quantitative analysis of MP forms of polyamide (PA), polyethylene (PE), polypropylene (PP), polystyrene (PS), and polyethylene terephthalate (PET), which are known to be most abundant in water, in a fast and easy way, new Attenuated Total Reflectance-Fourier Transform Infrared (ATR-FTIR) spectroscopy methods were tried to be developed by utilizing chemometric methods. While principal component analysis (PCA) was applied for qualitative analyses, partial least squares (PLS) models were created for quantitative analyses. Raw, 1st, and 2nd order derivatives of all spectra and their spectra with different levels of smoothing points were taken and 24 different chemometric models were created for each MP. In interpreting the statistical performances of the developed PCA and PLS models, different parameters were used. According to the obtained results, the qualitative discrimination of all polymer types was successfully achieved. It was determined that the PLS models developed for the quantitative determination of mixtures consisting of different concentrations of MP types could not be at the desired level. However, it was determined that the PLS models developed for PA, PE, PP, and PET, where the normal spectrum was used, could give quantitatively accurate results, albeit partially.