MODEL OF HYDROCARBONS TRANSPORT THROUGH THE POROUS GROUND MEDIA

Dispersion model of hydrocarbons transport in porous media has been presented. Mathematical description of this process allows to estimate whether the menace of ground waters can occur as a result of hydrocarbons transport through the soil. The convection term in the mass transport equation is taken into account due to the higher velocity of propagation in vertical direction. Additionally, introduction to the balance equation the biosorption link allows to take into account microorganisms influence on impurities concentration, especially on heavy oils derived compounds. To verify the theoretical model series of the experiment in the soil filter has been carried out.Представленная модель дисперсии транспортировки углеводородов в пористых средах. Математическое описание этого процесса позволяет оценить, есть ли угроза грунтовым водам в результате транспортировки углеводородов через почву. Срок конвекции в уравнении  переноса массы учитывается за счет более высокой скорости распространения в вертикальном направлении. Кроме того, введение в уравнения баланса ссылки биосорбции позволяет принять во во внимание влияниеколичества микроорганизмы от концентрации примесей,особенно тяжелых масел, полученных соединений. Чтобы проверить теоретическую модель в фильтре почвы была проведена серия экспериментов.Наведено модель дисперсії транспортування вуглеводнів у пористих середовищах. Математичний опис цього процесу дозволяє оцінити, чи є загроза ґрунтовим водам під час транспортування вуглеводнів через ґрунт. Термін конвекції в рівнянні перенесення маси враховується за рахунок вищої швидкості поширення у вертикальному напрямку. Крім того, введення в рівняння балансу посилання біосорбції дає змогу оцінити вплив кількості мікроорганізмів від концентрації домішок, особливо важких масел, отриманих сполук. Проведено серію експериментів з метою перевірки теоретичної моделі в фільтрі ґрунту

The impact of crosslinking monomers concentration on the properties of unsaturated polyester resins

The article illustrates the preparation of unsaturated polyester as well as the mechanical and thermal properties of his copolymers with crosslinking monomers (styrene and diethylene glycol dimethacrylate). The starting polyester was obtained from maleic anhydride, propylene glycol and isobutanol. The prepared series of unsaturated polyester resins were subjected to different studies concerning evaluation of their viscosity, mechanical and thermal properties and also dynamic mechanical behaviour (DMA)

Modification of polymeric materials bearing pendant epoxide groups

The polymer containing desired functional group can be obtained by a direct-polymerization or post-polymerization modification. These functionalization methods offer different way of insertion of functionality into the polymeric materials. In the literature, scientist can meet with the descriptions of many techniques of functionalization process. This review article focuses on the pathway for post-polymerization modification of polymeric materials bearing pendant epoxide groups

Students of the Medical College against the background of three other faculties of the Jan Kochanowski University in Kielce

The need to limit people-to-people contacts during the COVID-19 pandemic introduced the need for distance learning at universities. After two years of pandemic restrictions, we decided to check the opinion of medical students and three other faculties on the conducted classes and compare groups with each other. We conducted a survey research based on standardized questionnaire which included 306 students from four faculties of the Jan Kochanowski University in Kielce – Faculty of Law and Social Sciences (1), Medical College (2), Faculty of Exact and Life Sciences (3), Faculty of Pedagogy and Psychology (4). Students did not differ in the assessment of most types of classes conducted in a virtual form. The exceptions were virtual meetings in a group of students, which were better assessed at the faculty no. 1 compared to 2 and 4. Students of Medical College faculty differed in terms of assessing level of distance learning and their own involvement. Their ratings on these two issues were the lowest among the four groups. The students of individual faculties did not differ in terms of assessing the effectiveness of the elements of education in the traditional and remote modes of operation.   The subjective assessment of distance learning by students from various faculties shows subtle differences. The transition to distance education resulted in a decline in the involvement of medical students in their education and a subjective decrease in quality of teaching comparing to other faculties. This opinion may be taken into account when adapting curricula and selecting the type of classes to be conducted in the course of distance or hybrid learning

Comparison of the assessment of teaching components during distance and traditional learning – perspective of academic teachers and students. Questionnaire survey

The Covid-19 pandemic forced students and academic teachers to start distance learning. Although both sides participated in the same process, its assessment from both sides may differ. In our study, using a structured survey, academic teachers and students assessed on a 5-point Likert's scale (where 1 = greater in traditional education, 5 =definitely greater in remote education) the effectiveness of 6 key elements of learning such as: student's involvement (1), student's activity (2), contact with the lecturer (3), consistent manner of work (4), timeliness of tasks performed (5), quality of tasks performed (6) and adequacy of grades awarded (7) . Most of the elements in both groups were assessed as more effective in traditional learning. The average score in the group of teachers in each of the elements was shifted towards greater effectiveness of traditional teaching. The greatest difference in grades between the two groups occurred in the scope of a student's involvement and activity. Students and teachers did not differ in the assessment of contact with the lecturer, although both groups indicated that it was greater in the case of traditional learning. Lecturers and students differed in assessing the effectiveness of key features of learning during distance and traditional education. It is necessary to continuously adapt curricula in order to improve the overall assessment of the examined elements and to ensure that there are no differences between the two groups

Remote learning during the COVID-19 pandemic in the opinion of academic teachers. Survey research

During the COVID-19 pandemic, the academic community had to drop out of the full-time on-site education and switch to distance learning. After two years of this state of affairs and the current return to the traditional form, we would like to explore the opinions of academic teachers on this form of teaching.  The study was a questionnaire-based survey, including 86 teaching staff members of the Jan Kochanowski University of Kielce, working at four faculties. The teachers assessed the level of distance learning as average, no different from the traditional approach.  However, they pointed out that the involvement, activity of students, regularity of work, quality of the assignments completed, and the adequacy of the grades received is greater in the traditional approach. In the case of remote learning, in the group's assessment, the timeliness of performing the assignments had not deteriorated. The most frequently indicated advantage of remote learning was time saving, while the most common disadvantage was reduced contact with students. In the teachers' opinion, the traditional mode of learning still has an advantage over distance learning. Studies assessing effectiveness in achieving educational goals are needed in order to objectify the results. &nbsp

Embedding low loss polymer optical fibre Bragg gratings:two different approaches

In this paper, we present two different ways to embed polymer fibre Bragg gratings (FBGs) into polymer matrices. In the first experiment, we embedded the FBG into a 3D printed polymer structure, whereas in the second experiment, the coating was polymerized around the fibre. In both cases, the response of the grating was unchanged, without any loss or distortion of the FBG signal compared with the bare fibre response. The design of the polymer coating was optimised for the measurement of a single measurand. We highlighted two possible applications: surface bend deformation monitoring and improved-sensitivity temperature sensing

Bragg gratings inscription using PMMA polymer optical fibers drawn from preforms with specific thermal pre-treatment

In this work, fiber Bragg gratings (FBGs) are inscribed in various undoped poly(methyl methacrylate) (PMMA) polymer optical fibres (POFs) using different types of UV lasers and inscription time and their temperature and strain sensitivities are investigated. The polymer optical fiber Bragg gratings (POFBGs) were inscribed using two UV lasers: a continuous UV HeCd @325 nm laser and a pulsed UV KrF @248 nm laser. The PMMA POFs drawn from a preform without specific thermal pre-treatment need more inscription time than the fibers drawn from a preform that has been pre-annealed at 80ºC for 2 weeks. Using both UV lasers, for the latter fiber less than half the inscription time is needed compared with a commercial undoped PMMA POF and other homemade POFs, where the preforms have not had a well-defined thermal pre-treatment. The effect on a POF from a preform that has been annealed prior to drawing is different as previously shown in the literature, where these POFs are much less sensitive to thermal treatment. Also, a proper polymerization process plays a key role as will be discussed. These results indicate the impact of preform thermal pre-treatment as well as polymerization process before the PMMA POFs drawing, which can be an essential characteristic in view of developing POF sensors technology

Fast bragg grating inscription in PMMA polymer optical fibres:impact of thermal pre-treatment of preforms

In this work, fibre Bragg gratings (FBGs) were inscribed in two different undoped poly- (methyl methacrylate) (PMMA) polymer optical fibres (POFs) using different types of UV lasers and their inscription times, temperature and strain sensitivities are investigated. The POF Bragg gratings (POFBGs) were inscribed using two UV lasers: a continuous UV HeCd @325 nm laser and a pulsed UV KrF @248 nm laser. Two PMMA POFs are used in which the primary and secondary preforms (during the two-step drawing process) have a different thermal treatment. The PMMA POFs drawn in which the primary or secondary preform is not specifically pre-treated need longer inscription time than the fibres drawn where both preforms have been pre-annealed at 80 °C for 2 weeks. Using both UV lasers, for the latter fibre much less inscription time is needed compared to another homemade POF. The properties of a POF fabricated with both preforms thermally well annealed are different from those in which just one preform step process is thermally treated, with the first POFs being much less sensitive to thermal treatment. The influence of annealing on the strain and temperature sensitivities of the fibres prior to FBG inscription is also discussed, where it is observed that the fibre produced from a two-step drawing process with well-defined pre-annealing of both preforms did not produce any significant difference in sensitivity. The results indicate the impact of preform thermal pre-treatment before the PMMA POFs drawing, which can be an essential characteristic in the view of developing POF sensors technology