Comprehensive Studies of Adsorption Equilibrium and Kinetics for Selected Aromatic Organic Compounds on Activated Carbon.

This work presents a comprehensive analysis of the adsorption of selected aromatic organic compounds on activated carbons. Both the equilibrium and kinetics of adsorption were studied using UV-Vis spectrophotometry. The influence of a number of factors: pH, contact time, presence of an accompanying substance, adsorbate concentration, as well as the mass and size of adsorbent grains, on the adsorption process from aqueous solutions was investigated. Phenol, 2-nitrophenol, 3-nitrophenol, 4-nitrophenol and methylene blue (as an accompanying substance) were selected as adsorbates. GAC 1240W and RIAA activated carbons were used as adsorbents. The equilibrium data were analyzed using the generalized Langmuir isotherm equation (R2 = 0.912-0.996). Adsorption rate data were fitted using a multi-exponential kinetic equation (1 - R2 = (1.0 × 10-6)-(8.2 × 10-4)). As an additional parameter, the half-time was also used to present the influence of selected factors on the adsorption kinetics. An increase in the amount of adsorption was demonstrated with increasing contact time as well as with decreasing solution pH and adsorbent grain size. For selected systems, an increase in the adsorption rate was observed with increasing adsorbate concentration, adsorbent mass and at lower pH values. In some cases, the presence of an accompanying substance also resulted in an increase in adsorption kinetics. In the tested experimental systems, optimal conditions for adsorption were established (T = 298 K, pH = 2, contact time: 7 days, grain diameter: >0.5 mm and the ratio of the mass of the adsorbent to the volume of the adsorbate solution: 1 g/L). Additionally, the acid-base properties (potentiometric titration), morphology (SEM) and structure (TEM) of the used adsorbents were also examined.

A novel chitosan-alginate@Fe/Mn mixed oxide nanocomposite for highly efficient removal of Cr (VI) from wastewater: Experiment and adsorption mechanism.

In this study, the synthesis and experimental theoretical evaluation of a new chitosan/alginate/hydrozyapatite nanocomposite doped with Mn2 and Fe2O3 for Cr removal was reported. The physicochemical properties of the obtained materials were analyzed using the following methods: SEM-EDX, XRD, FTIR, XPS, pH drift measurements, and thermal analysis. The adsorption properties were estimated based on equilibrium and adsorption kinetics measurements. The Langmuir, Freundlich and Temkin isotherms were applied to analyze the equilibrium data. The thermodynamic analysis of adsorption isotherms was performed. A number of equations and kinetic models were used to describe the adsorption rate data, including pseudo-first (PFOE) and pseudo-second (PSOE) order kinetic equations. The obtained test results show that the synthesized biomaterial, compared to pure chitosan, is characterized by greater resistance to high temperatures. Moreover, this biomaterial had excellent adsorption properties. For the adsorption of Cr (VI), the equilibrium state was reached after 120 min, and the sorption capacity was 455.9 mg/g. In addition, DFT calculations and NCI analyses were performed to get more light on the adsorption mechanism of Cr (VI) on the prepared biocomposite.

Studies on the Process of Basic Dyes Adsorption on Uniform Spherical Carbons.

The influence of carbon pore structure on the sorption process of selected cationic dyes has been investigated. The structure and surface of carbonaceous materials have been characterized basing on various techniques: scanning electron microscopy, low temperature nitrogen adsorption-desorption measurements, X-ray photoelectron spectroscopy and thermal analysis combined with identification of gaseous products. The kinetic and equilibrium adsorption measurements of Basic Violet 3, Basic Red 1 and Basic Blue 9 from aqueous media were performed. The studied carbons seem to be promising adsorbents towards dyes, taking into account the easy-to-use uniform spherical form of the granules and a complex type of porosity with micro-, meso- and macropores appropriate for large molecule adsorption.

Adsorption of Non-Steroidal Anti-Inflammatory Drugs on Alginate-Carbon Composites-Equilibrium and Kinetics.

In this work, alginate-carbon composites with different active carbon content were synthesized and studied by various techniques. The obtained materials can be used as adsorbents in the processes of removing organic pollutants from water. In this study, the effect of the immobilization of activated carbon in calcium alginate was investigated. Textural properties were determined by measuring low-temperature nitrogen adsorption/desorption isotherms. The largest specific surface area was recorded for ALG_C8 and amounted to 995 m2/g. The morphology of alginate materials was determined on the basis of scanning electron microscopy. The adsorption properties were estimated based on the measurements of equilibrium and adsorption kinetics. The highest sorption capacities were 0.381 and 0.873 mmol/g for ibuprofen and diclofenac, respectively. The generalized Langmuir isotherm was used to analyze the equilibrium data. A number of equations and kinetic models were used to describe the adsorption rate data, including first (FOE) and second (SOE) order kinetic equations, 1,2-mixed-order kinetic equation (MOE), fractal-like MOE equation (f-MOE), multi-exponential equation (m-exp), in addition to diffusion models: intraparticle diffusion model (IDM) and pore diffusion model (PDM). Thermal stability was determined on the basis of data from thermal analysis in an atmosphere of synthetic air.

Physicochemical and Adsorption Characteristics of Divinylbenzene-co-Triethoxyvinylsilane Microspheres as Materials for the Removal of Organic Compounds.

In this work, organic-inorganic materials with spherical shape consisting of divinylbenzene (DVB) and triethoxyvinylsilane (TEVS) were synthesized and investigated by different complementary techniques. The obtained microspheres may be applied as sorbent systems for the purification of organic compounds from water. The hybrid microspheres combine the properties of the constituents depending on the morphologies and interfacial bonding. In this work, the influence of the molar ratio composition of crosslinked monomer (DVB) and silane coupling agent (TEVS) (DVB:TEVS molar ratios: 1:2, 1:1 and 2:1) on the morphology and quality of organic-inorganic materials have been examined. The materials were analysed using small angle X-ray scattering (SAXS) analysis, low-temperature nitrogen sorption, scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) to provide information on their structural and surface properties. Moreover, thermal analysis was performed to characterize the thermal stability of the studied materials and the adsorbent-adsorbate interactions, while adsorption kinetic studies proved the utility of the synthesized adsorbents for water and wastewater treatment.

Federated Learning for 5G Radio Spectrum Sensing.

Spectrum sensing (SS) is an important tool in finding new opportunities for spectrum sharing. The users, called Secondary Users (SU), who do not have a license to transmit without hindrance, need to employ SS in order to detect and use the spectrum without interfering with the licensed users' (primary users' (PUs')) transmission. Deep learning (DL) has proven to be a good choice as an intelligent SS algorithm that considers radio environmental factors in the decision-making process. It is impossible though for SU to collect the required data and train complex DL models. In this paper, we propose to employ a Federated Learning (FL) algorithm in order to distribute data collection and model training processes over many devices. The proposed method categorizes FL devices into groups by their mean Signal-to-Noise ratio (SNR) and creates a common DL model for each group in the iterative process. The results show that detection accuracy obtained via the FL algorithm is similar to detection accuracy obtained by employing several DL models, namely convolutional neural networks (CNNs), specialized in spectrum detection for a PU signal with a given mean SNR value. At the same time, the main goal of simplification of the SS process in the network is achieved.

Mesocellular Silica Foams (MCFs) with Tunable Pore Size as a Support for Lysozyme Immobilization: Adsorption Equilibrium and Kinetics, Biocomposite Properties.

The effect of the porous structure of mesocellular silica foams (MCFs) on the lysozyme (LYS) adsorption capacity, as well as the rate, was studied to design the effective sorbent for potential applications as the carriers of biomolecules. The structural (N2 adsorption/desorption isotherms), textural (SEM, TEM), acid-base (potentiometric titration), adsorption properties, and thermal characteristics of the obtained lysozyme/silica composites were studied. The protein adsorption equilibrium and kinetics showed significant dependence on silica pore size. For instance, LYS adsorption uptake on MCF-6.4 support (pore diameter 6.4 nm) was about 0.29 g/g. The equilibrium loading amount of LYS on MCF-14.5 material (pore size 14.5 nm) increased to 0.55 g/g. However, when the pore diameter was larger than 14.5 nm, the LYS adsorption value systematically decreased with increasing pore size (e.g., for MCF-30.1 was only 0.27 g/g). The electrostatic attractive interactions between the positively charged lysozyme (at pH = 7.4) and the negatively charged silica played a significant role in the immobilization process. The differences in protein adsorption and surface morphology for the biocomposites of various pore sizes were found. The thermal behavior of the studied bio/systems was conducted by TG/DSC/FTIR/MS coupled method. It was found that the thermal degradation of lysozyme/silica composites was a double-stage process in the temperature range 165-420-830 °C.

Risk of eating disorders in university students: an international study in Hungary, Poland and Ukraine.

OBJECTIVE: In this international study, the prevalence of Eating disorders (EDs) was determined among university students and identified associated demographic and behavioral factors predicting disorders using data from three European countries. METHODS: The survey was conducted in Hungary, Poland, and Ukraine in 2018. Registered full-time students completed an online anonymous questionnaire. Students provided data about socioeconomic characteristics, body mass index (BMI), EDs, physical fitness and sport practice, psychological distress (stress, anxiety, depression), life orientation, alcohol, tobacco, and cannabis use. Data were analyzed using SPSS 24.0 software. RESULTS: From the 1965 returned questionnaires 1950 were analyzed, because of the missing data (67.3% female, mean age of the total participant's 21.40 ± 3.83 years old). EDs were observed in 26.3% of students. In logistic regression, EDs were predicted by female sex, higher BMI, single marital status, elevated psychological distress and limited access to health care. CONCLUSION: EDs are relatively common in university students especially in females. Students with higher distress and BMI, limited access to health care and living without partner are at risk for EDs. This result highlights the need for a public health approach. Universities are the last chance where students can be screened in an organized setting and offer interventions early when treatment is likely to be most effective.

Machine Learning for LTE Energy Detection Performance Improvement.

The growing number of radio communication devices and limited spectrum resources are drivers for the development of new techniques of dynamic spectrum access and spectrum sharing. In order to make use of the spectrum opportunistically, the concept of cognitive radio was proposed, where intelligent decisions on transmission opportunities are based on spectrum sensing. In this paper, two Machine Learning (ML) algorithms, namely k-Nearest Neighbours and Random Forest, have been proposed to increase spectrum sensing performance. These algorithms have been applied to Energy Detection (ED) and Energy Vector-based data (EV) to detect the presence of a Fourth Generation (4G) Long-Term Evolution (LTE) signal for the purpose of utilizing the available resource blocks by a 5G new radio system. The algorithms capitalize on time, frequency and spatial dependencies in daily communication traffic. Research results show that the ML methods used can significantly improve the spectrum sensing performance if the input training data set is carefully chosen. The input data sets with ED decisions and energy values have been examined, and advantages and disadvantages of their real-life application have been analyzed.

Physical activity and associated socio-demographic factors in adolescents from the eastern region of Poland

Background: The introduction and maintenance of healthy habits in the field of physical activity at the early stage of life is particularly important for public health. With increasing of public awareness in physical activity, researchers are increasingly questioning its determinants in different age groups. In this paper we focus on variables such as age, sex and place of residence. Objectives: To determine what selected socio-demographic factors influence the level of physical activity of school youth from the eastern region of Poland in different domains of daily life. Material and Methods: A random sample of 916 Polish school youth from Secondary Schools from Eastern Region of Poland aged 16-18 was interviewed in spring 2016 by diagnostic survey method with the use of the official Polish long version of the International Physical Activity Questionnaire (IPAQ). Results: Analysing the relationship between gender and the level of physical activity statistically significant differences were found in all domains in favour of boys. The level of total physical activity in girls was 5345.5 MET-min./week, whereas in boys ­ 6556.6 MET-min./week. In the area of total physical activity, the highest values were observed in pupils from small towns and villages, with lower values in the youth living in large and medium-sized cities. When the relationship of age with the level of physical activity in particular domains was examined, only the activity in the work/ school domain (p = 0.0129) spoke in favour of the youngest pupils (2578.7 MET-min./week) when compared to the oldest ones (2226.4 MET-min./week). Conclusions: The level of physical activity in young people from the Eastern region of Poland is decreasing with age, both in girls and boys. It is therefore important, especially for the group emerging adulthood, to offer a wide variety of updated, involving, age and gender-oriented school physical activity classes that could be easily practised outside the school environment to improve the level of physical activity in leisure domain

[Mucoepidermoid cancer of parotid gland in 14-years-old girl--case report]. / Rak sluzowo-naskórkowy slinianki przyusznej u 14-letniej dziewczynki - opis przypadku.

INTRODUCTION: Malignant tumors of salivary glands are rare, especially in children. MATERIAL AND METHOD: We present a case report of 14-years-old girl affected by mucoepidermoid cancer of parotid gland. RESULTS: Patient was admitted to our Department in May 2007 due to small, hard, moveable tumor localized in right mandibular angle. The VII nerve function was normal. Fine needle aspiration revealed inflammatory cells without atypical cytologic features. Intraoperative tumor was hard, with irregular surface, surrounded by capsule, connected with the main trunk of facial nerve and cartilaginous part of external auditory meatus. Tumor was excised together with superficial part of parotid gland and surrounding lymph nodes. After operation no signs of facial nerve damage were observed. Postoperative histopathological examination revealed mucoepidermoid cancer, in 2 out of 6 specimens neoplasmatic cells were seen in border of excised tissue. In June 2007 the second operation was performed. Remain part of parotid gland was removed with right facial nerve and conservative lymph node resection. Facial nerve and its branches were reconstructed with sural and great auricular nerve as donor grafts. The symptoms of nerve damage were observed in early postoperative days adequate to 5th degree of House-Brackman scale (HB5). 4 years after operation function of facial nerve is estimated on HB3. The girl is under regular oncological and laryngological control free of neoplasm recurrence. CONCLUSIONS: Diagnostics and treatment of malignant parotid tumors in children are difficult and clinical picture must be always taken into consideration as the most important factor.

[Surgical methods of treating patients with laryngeal and hypopharyngeal cancer in Szczecin's EMT University Department during the years 1970-2002]. / Chirurgiczne metody leczenia raka krtani i gradla dolnego stosowane w Klinice Szczecinskiej w latach 1970-2002.

In the thesis are presented surgical methods of treating larynx and hypopharynx cancer used in the Szczecin Clinic throughout more than 30 years, i.e. between 1970 and 2002. During this period in the Szczecin center 2591 patients ill of larynx cancer underwent surgical treatments. In the analysed period was recorder an increase in: a) the number of patients suffering from larynx and hypopharynx cancer, b) patients' average age, c) percentage of larynx cancer sick rate in females in relation to males and d) the number of patients with advanced stage of disease. Predominant with the patients were supraglottic cancers, however in the recent years there was an increase in the number of glottic cancer patients. In the years 1970-1980 prevailed partial laryngectomies and total laryngectomies were performed sporadically. In the next decade, what became noticeable was a drop in operations with creation of autoplastic vocal shunt and a growth in the number of partial operations with the preservation of respiratory way. In the last decade there was also an increase in the number of operations of total laryngectomies and a decrease in the number of partial operations, whereas the number of performed subtotal operations with the reconstruction of phonatory functions remained at the same level. Oncological and functional results assessed both subjectively and objectively after all kinds of laryngectomies were satisfactory. In the thesis attention was also paid to surgical methods elaborated in the Clinic, which substantially contributed to the progress in surgical treatment of larynx cancer as well as to improvements in revalidation of the phonatory function and its quality with patients after total, subtotal and partial removal of larynx structures.

[Morphology and function of the pharyngoesophageal segment]. / Morfologia i funkcja segmentu gardlowo-przelykowego.

Basing on the review of the foreign and domestic literature the point of view concerning the anatomical structure, innervation and histomorphology of the pharyngoesophageal segment (pes) is being presented. Special attention was paid to the impact of the somatic and autonomic (particularly its sympathetic part) nervous system on the function of the pharynx, as well as the pressure at rest with the pharyngoesophageal sphincter. Histomorphologic investigations suggest that the pes function and tension of the particular pharyngeal constrictors (upper, middle and inferior) is determined by: a) structure, b) distribution of the IX and X nerve fibre ends in pharyngeal sphincters, c) structure of the pharyngeal sphincter, which is also supplied with the nervous fibre ends of the upper cervical sympathetic trunk. The sympathetic trunk is located on both sides of vertebral column from the skull base till the tip of the sacral bone. In case of degenerative process in the neck segment of the vertebral column, irritation of the sympathetic part of the autonomic system is taking place. Experimental investigations revealed that the stimulation of the sympathetic nervous fibres of the autonomic system results in weakening of the upper and middle pharyngeal sphincter's tension and increase of tension in its lower part (cricopharyngeal muscle). This can be an etiopathogenic factor under physiological condition in disturbances of the pharyngeal phase of deglutition act. After total laryngectomy, however, high pressure in the lower part of the pes (in the area of pharyngoesophageal sphincter) renders it difficult or even impossible to introduce the air into the esophagus to master the phonation and esophageal speech. The significance of the knowledge of the pes innervation in clinical practice is important for prognosis in mastering of supplementary, esophageal and shunt phonation.