CHEMICAL REMEDIATION TECHNOLOGIES

Environmental pollution remains one of the most serious world problems. Great efforts are made to limit the release of harmful compounds into the environment, and a variety of methods for remediation of soil, surface water and groundwater have been developed over the years. Chemical remediation technologies are of great interest since they can remove and degrade pollutants in contaminated sites. This paper focuses on several chemical remediation technologies, such as precipitation, flocculation, adsorption and ion-exchange, chemical oxidation, soil washing and flushing and electrokinetic remediation. Remediation technologies are almost always combined with one another, although they can be used separately. Choosing an appropriate techonolgy will depend on the type of the pollutants and site conditions, and it should be done in such manner so that the most cost-effective and efficient technology is chosen. Even though some of the technologies are used full-scale, research should be focused on enhancing the existing, and developing new remediation technologies

New complexity measures reveal that topographic loops of human alpha phase potentials are more complex in drowsy than in wake

A number of measures, stemming from nonlinear dynamics, exist to estimate complexity of biomedical objects. In most cases they are appropriate, but sometimes unconventional measures, more suited for specific objects, are needed to perform the task. In our present work, we propose three new complexity measures to quantify complexity of topographic closed loops of alpha carrier frequency phase potentials (CFPP) of healthy humans in wake and drowsy states. EEG of ten adult individuals was recorded in both states, using a 14-channel montage. For each subject and each state, a topographic loop (circular directed graph) was constructed according to CFPP values. Circular complexity measure was obtained by summing angles which directed graph edges (arrows) form with the topographic center. Longitudinal complexity was defined as the sum of all arrow lengths, while intersecting complexity was introduced by counting the number of intersections of graph edges. Wilcoxon’s signed-ranks test was used on the sets of these three measures, as well as on fractal dimension values of some loop properties, to test differences between loops obtained in wake vs. drowsy. While fractal dimension values were not significantly different, longitudinal and intersecting complexities, as well as anticlockwise circularity, were significantly increased in drowsy

Generalized Poincaré plots analysis of heart period dynamics in different physiological conditions: Trained vs. untrained men

Background Recently we proposed a new method called generalized Poincare´ plot (gPp) analysis which gave a new insight into the pattern of neurocaridac control. In this study we examined potential of gPp method to reveal changes in cardiac neural control in young athletes during three conditions: supine rest, running and relaxation, with respect to untrained subjects. Methods This method is based on the quantification of Pearson's correlation coefficients r(j, k), between symmetrical (j = k) and asymmetrical summed j previous and k following RR intervals up to the 100th order (j,k.100). Results Differences between groups were obtained at all levels of this analysis. The main result is the significant difference of NAI, normalized index of asymmetry, between groups in running, which was originated in different positions of local maxima of r(j, k). Compared with untrained subjects, these findings indicate modified neural control and altered intrinsic heart rate behavior in athletes which are related to some kind of memory mechanism between RR intervals. Conclusion Obtained results provide great potential of gPp method analysis in the recognition of changes in neurocardiac control in healthy subjects. Further studies are needed for identification of altered cardiac regulatory mechanisms whose background may be useful in the evaluation of genesis of athletes neurocardiovascular pathology. © 2019 Platiša et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited

Extracting complexity waveforms from one-dimensional signals

Background: Nonlinear methods provide a direct way of estimating complexity of one-dimensional sampled signals through calculation of Higuchi's fractal dimension (1<FD<2). In most cases the signal is treated as being characterized by one value of FD and consequently analyzed as one epoch or, if divided into more epochs, often only mean and standard deviation of epoch FD are calculated. If its complexity variation (or running fractal dimension), FD(t), is to be extracted, a moving window (epoch) approach is needed. However, due to low-pass filtering properties of moving windows, short epochs are preferred. Since Higuchi's method is based on consecutive reduction of signal sampling frequency, it is not suitable for estimating FD of very short epochs (N < 100 samples).Results: In this work we propose a new and simple way to estimate FD for N < 100 by introducing 'normalized length density' of a signal epoch,.where yn(i) represents the ith signal sample after amplitude normalization. The actual calculation of signal FD is based on construction of a monotonic calibration curve, FD = f(NLD), on a set of Weierstrass functions, for which FD values are given theoretically. The two existing methods, Higuchi's and consecutive differences, applied simultaneously on signals with constant FD (white noise and Brownian motion), showed that standard deviation of calculated window FD (FDw) increased sharply as the epoch became shorter. However, in case of the new NLD method a considerably lower scattering was obtained, especially for N < 30, at the expense of some lower accuracy in calculating average FDw. Consequently, more accurate reconstruction of FD waveforms was obtained when synthetic signals were analyzed, containig short alternating epochs of two or three different FD values. Additionally, scatter plots of FDwof an occipital human EEG signal for 10 sample epochs demontrated that Higuchi's estimations for some epochs exceeded the theoretical FD limits, while NLD-derived values did not.Conclusion: The presented approach was more accurate than the existing two methods in FD(t) extraction for very short epochs and could be used in physiological signals when FD is expected to change abruptly, such as short phasic phenomena or transient artefacts, as well as in other fields of science. © 2009 Kalauzi et al; licensee BioMed Central Ltd

Pulse respiration quotient as a measure sensitive to changes in dynamic behavior of cardiorespiratory coupling such as body posture and breathing regime

In this research we explored the (homeo)dynamic character of cardiorespiratory coupling (CRC) under the influence of different body posture and breathing regimes. Our tool for it was the pulse respiration quotient (PRQ), representing the number of heartbeat intervals per breathing cycle. We obtained non-integer PRQ values using our advanced Matlab® algorithm and applied it on the signals of 20 healthy subjects in four conditions: supine position with spontaneous breathing (Supin), standing with spontaneous breathing (Stand), supine position with slow (0.1 Hz) breathing (Supin01) and standing with slow (0.1 Hz) breathing (Stand01).Main results: Linear features of CRC (in PRQ signals) were dynamically very sensitive to posture and breathing rhythm perturbations. There are obvious increases in PRQ mean level and variability under the separated and joined influence of orthostasis and slow (0.1 Hz) breathing. This increase was most pronounced in Stand01 as the state of joint influences. Importantly, PRQ dynamic modification showed greater sensitivity to body posture and breathing regime changes than mean value and standard deviation of heart rhythm and breathing rhythm. In addition, as a consequence of prolonged supine position, we noticed the tendency to integer quantization of PRQ (especially after 14 min), in which the most common quantization number was 4:1 (demonstrated in other research reports as well). In orthostasis and slow breathing, quantization can also be observed, but shifted to other values. We postulate that these results manifest resonance effects induced by coupling patterns from sympathetic and parasympathetic adjustments (with the second as dominant factor).Significance: Our research confirms that cardiorespiratory coupling adaptability could be profoundly explored by precisely calculated PRQ parameter since cardiorespiratory regulation in healthy subjects is characterized by a high level of autonomic adaptability (responsiveness) to posture and breathing regime, although comparisons with pathological states has yet to be performed. We found Stand01 to be the most provoking state for the dynamic modification of PRQ (cardiorespiratory inducement). As such, Stand01 has the potential of using for PRQ tuning by conditioning the cardiorespiratory autonomic neural networks, e.g., in the cases where PRQ is disturbed by environmental (i.e., microgravity) or pathologic conditions

iTrust News Certificate: A Blockchain-Based Solution for News Verification and Reputation Management

The proliferation of fake news and misinformation in the digital era poses a significant challenge to news organizations and content creators. In this paper, we intro-duce the iTrust News Certificate, the architecture of an online blockchain-based solution designed to combat fake news, enhance news verification, and maintain reputation within the media ecosystem. Unlike previous attempts, iTrust News Certificate focuses on us-er-friendly features while ensuring transparency and reliability. By leveraging blockchain technology, iTrust News Certificate establishes a decentralized and immutable ledger for storing news-related metadata. This ledger ensures the integrity and traceability of news articles, making it extremely difficult for malicious actors to tamper with or propagate false information

APPLICATION OF MEMBRANE TECHNOLOGY IN THE TREATMENT AND ANALYSIS OF TRIAZINE PESTICIDES IN WATER

The quality of consumable water is decreasing due to increasing water pollution caused by the production and use of human-made chemicals. A significant part of these chemicals are pesticides from the class of triazines since they are widely used in agriculture as herbicides. Water treatment techniques mainly rely on separation science, where the membrane technology has been identified as the most useful. Membrane processes used in water treatment are microfiltration, ultrafiltration, nanofiltration and reverse osmosis. In general, the pollutant retention/rejection by membranes depends on the physicochemical properties of the membrane i.e. membrane material, porosity, pore size and on the properties of the pollutant molecule i.e. size, length, width, molecular weight, hydrophobicity or dipole moment. The pollutant retention also depends on the feed-water composition (organic matter and salt presence, solute concentration, water pH). Thus, effective water treatment depends on the selection of an appropriate type of membrane for a particular type of pollutants. Membrane technology is also significant because it is used in polluted water analysis, more precise as a part of a liquid-phase or solid-phase microextraction. Among several developed membrane-based microextraction methods, in triazine polluted water analysis common are membrane-protected solid-phase microextraction and hollow-fiber liquid-phase microextraction. In this field, researchers tend to achieve membrane-pollutant compatibility through the synthesis of polymeric materials with molecular recognition properties i.e. through a technology called molecular imprinting. HIGHLIGHTSAmong several water treatment techniques, the membrane technology has been identified as the most robust and flexible one.The most common water pollutants are triazine pesticides since they are widely used in agriculture as herbicides.The triazines retention by membranes depends on the membrane and triazine molecule properties, but also on the feed-water composition.Thanks to the molecular imprinting technology, membrane technology has found its application in polluted water analysis as a part of sample preparation

Deformation mechanisms in ti3al-nb alloy at elevated temperatures

Ti3Al-11Nb-1V (x/%) was made in a vacuum arc furnace. Hot-rolling was conducted at 1050 degrees C in a two-phase field of the alloy. Strain-rate jump tests were performed at T = 800-1100 degrees C and strain rates of 10(-6) to 10(-3) s(-1). Creep stress exponent (n) and activation energy for deformation (Q) were used to identify deformation mechanisms. Two sequential mechanisms are revealed: (i) viscous glide, typical of solid solution alloys and, (ii) power law breakdown at lower temperatures. Activation energy for deformation was found to be strongly stress-dependant

Slow 0.1 Hz Breathing and Body Posture Induced Perturbations of RRI and Respiratory Signal Complexity and Cardiorespiratory Coupling

Objective: We explored the physiological background of the non-linear operating mode of cardiorespiratory oscillators as the fundamental question of cardiorespiratory homeodynamics and as a prerequisite for the understanding of neurocardiovascular diseases. We investigated 20 healthy human subjects for changes using electrocardiac RR interval (RRI) and respiratory signal (Resp) Detrended Fluctuation Analysis (DFA, α1RRI, α2RRI, α1Resp, α2Resp), Multiple Scaling Entropy (MSERRI1−4, MSERRI5−10, MSEResp1−4, MSEResp5−10), spectral coherence (CohRRI−Resp), cross DFA (ρ1 and ρ2) and cross MSE (XMSE1−4 and XMSE5−10) indices in four physiological conditions: supine with spontaneous breathing, standing with spontaneous breathing, supine with 0.1 Hz breathing and standing with 0.1 Hz breathing. Main results: Standing is primarily characterized by the change of RRI parameters, insensitivity to change with respiratory parameters, decrease of CohRRI−Resp and insensitivity to change of in ρ1, ρ2, XMSE1−4, and XMSE5−10. Slow breathing in supine position was characterized by the change of the linear and non-linear parameters of both signals, reflecting the dominant vagal RRI modulation and the impact of slow 0.1 Hz breathing on Resp parameters. CohRRI−Resp did not change with respect to supine position, while ρ1 increased. Slow breathing in standing reflected the qualitatively specific state of autonomic regulation with striking impact on both cardiac and respiratory parameters, with specific patterns of cardiorespiratory coupling. Significance: Our results show that cardiac and respiratory short term and long term complexity parameters have different, state dependent patterns. Sympathovagal non-linear interactions are dependent on the pattern of their activation, having different scaling properties when individually activated with respect to the state of their joint activation. All investigated states induced a change of α1 vs. α2 relationship, which can be accurately expressed by the proposed measure—inter-fractal angle θ. Short scale (α1 vs. MSE1−4) and long scale (α2 vs. MSE5−10) complexity measures had reciprocal interrelation in standing with 0.1 Hz breathing, with specific cardiorespiratory coupling pattern (ρ1 vs. XMSE1−4). These results support the hypothesis of hierarchical organization of cardiorespiratory complexity mechanisms and their recruitment in ascendant manner with respect to the increase of behavioral challenge complexity. Specific and comprehensive cardiorespiratory regulation in standing with 0.1 Hz breathing suggests this state as the potentially most beneficial maneuver for cardiorespiratory conditioning. © Copyright © 2020 Matić, Platiša, Kalauzi and Bojić