International Scientific Publications
Not a member yet
2817 research outputs found
Sort by
COVID-19 IMPACT ON HIGHER EDUCATION: PERCEPTIONS AMONG UNIVERSITY TEACHERS IN BULGARIA
Get PDFHigher education has been severely affected by the COVID-19 pandemic. Although the transition to online learning was initially seen as a success, subsequently this form of education and the ongoing ambiguities regarding the conduct of classes have been generating many critical opinions from both teachers and students. This study is based on a survey among 194 university professors from twenty higher education institutions from all statistical regions in Bulgaria about their perceptions of the impact of COVID-19 on the higher education system in the country, including in terms of their teaching and research activities. The respondents’ answers reveal generally an unwillingness of the teaching staff with the online form of education, especially when it comes to quality. Based on the survey results, we claim that whereas the pandemic situation has created new opportunities for the development of the higher education system, this sector should not be narrowed to simply another form of business
INTERNALIZATION OF THE UNIVERSITY IN THE LIGHT OF THE RELATIONSHIP BETWEEN ACADEMIC TEACHERS AND STUDENTS: A CASE STUDY OF THE JAGIELLONIAN UNIVERSITY
Get PDFThe aim of this study is to identify the changes brought about by the transformation of the University’s structure at the level of academic teacher-student relations. The starting point for the research reported here is the assumption that the coherence and stability of a University structure conducive to internationalization depends on the recognition of the value system that forms the content of the University. The smallest unit of research is the arrangement of two elements: the lecturer (academic teacher) and the student. This arrangement is multiplied. The aim of the study is to identify the dominant type of relationship of these two elements. The research hypothesis is that relationships constitute a certain type of content, which influences the structure. Consequently, content is an important factor in the success or failure of the internationalization process. The research material consists of data collected through semi-structured interviews. Content analysis was used to examine the data. Relational analysis was chosen to analyse the relationships between student* and teacher*. Final conclusions were drawn from a compilation of data obtained from students and contrasted with the data obtained from the teachers. Firstly, relationships are hierarchical, shaped by University tradition, age and knowledge difference. Secondly, there is a discrepancy in the semantics of the word authority: for the students it means a high, overawing degree of the teacher’s knowledge; for the teacher - being a personal role model. At the lexical level, to the greatest extent mutual relationships are shaped by the words student-teacher; mentor-mentee. Thirdly, the values that shape the reciprocal relationship are kindness and fairness. Internationalization is assessed negatively from the perspective of disrupting the hierarchical order, giving the University’s structure stability and the members of the academic community unquestionable knowledge of their rights and responsibilities
WHEN GIVING IS NOT RECEIVING: THE SIGNIFICANCE OF HOW FEEDBACK IS GIVEN ON STUDENTS’ WRITTEN ASSIGNMENTS
Get PDFResearch across all spectrums of multi-disciplinary learning, in higher education, has concluded that teacher written feedback after the completion of a written assignment, in a product approach writing course, is rarely read and implemented by students. The fundamental reason for this is that students perceive it to be of little relevance to future assignments (Crisp 2007; Tom et al. 2013). Therefore, for students to learn and grow as academic writers, intervention is required during the writing process (Hattie and Clarke 2019; Hattie and Timperley 2007). This intervention can be, for example, in the form of teacher-student feedback and peer feedback, in verbal and written communication. As a contribution to this process, this paper explores the possible use of key strategies from the work of Berne (1961, 1964, 1974, 2018, 2010) and his theory of Transactional Analysis (TA), (DGTA e.V.) in the context of teachers communicating both formative and summative feedback on student academic writing. Key tools from TA will be presented and shown to support in the delivery of feedback. Furthermore, the significance of understanding individual beliefs, whether it be your own or that of your students, will be addressed. A step-by-step guide is then presented with representative examples to exemplify how these strategies were implemented in two academic writing courses in higher education. Benefits of this strategy included reduced marking and grading time and gratifying learning outcomes, including an average grade score of 84% in the final term written assignment
NANOSCALE CU0.5ZN0.5FE2O4 FERRITES HOSTED IN MESOPOROUS TIO2-MO2 (M=CE, ZR, SN) MIXED OXIDES FOR SUSTAINABLE ENVIRONMENTAL PROTECTION
Get PDFThis study is aimed at the preparation of homogeneous, nanostructured and high surface area titania doped with CeO2, ZrO2 and SnO2 mesoporous oxides. These materials are used as a host matrix of Cu0.5Zn0.5Fe2O4 ferrite nanoparticles. The obtained composites are characterized by a complex of physicochemical techniques, such as nitrogen physisorption, XRD, SEM, HRTEM, Temperature – programmed reduction with hydrogen, XPS, UV-Vis and Moessbauer spectroscopies. Their catalytic behavior is tested in methanol decomposition as a source of hydrogen and total oxidation of ethyl acetate as a representative volatile organic compound. A synergistic activity between the acidic sites on the mixed oxide surface and the redox transitions in the hosted on them ferrite nanoparticles is well established. This effect is in a complex dependence on the surface and texture characteristics of the mesoporous TiO2-MO2 host matrix. The catalytic properties in both catalytic processes are optimized using mesoporous TiO2-CeO2 mixed oxide as a support of the Cu0.5Zn0.5Fe2O4 ferrite nanoparticles
EFFECT OF HEAT TREATMENT ON MECHANICAL PROPERTIES OF 3D PRINTED SPECIMENS
Get PDFCurrently, there is a need in some areas of metal construction materials for their lighter and cheaper alternative, which will have the same or better properties in terms of value and price. One of the most suitable and used alternatives are composite materials. When choosing a suitable composite material, it is necessary to take into account not only the necessary mechanical properties, but also the thermal load of the machine part. There were no permanent changes in the properties of metal materials, but we can notice changes in properties of composite materials that can positively or negatively affect the strength or life of the part. Due to this fact, presented is focused on the application of the effect of thermal loading of components made of composite materials using 3D printing on their mechanical properties. Laboratory tests were performed on test specimens prescribed for individual tests of mechanical properties. After performing the process of annealing the samples, we performed mechanical tests. Based on the obtained results, it is possible to determine the effect of annealing to the mechanical properties of the selected material and also we can determine the maximum operating temperature at which the properties of the material do not deteriorate
PREPARATION OF FLEXIBLE DIELECTRIC NANOCOMPOSITES USING NANOCELLULOSE AND RECYCLED ALUM SLUDGE FOR WEARABLE TECHNOLOGY APPLICATIONS
Get PDFWith the rapid development of wearable technology, flexible dielectric materials with environmental- friendly, low-cost and high-energy efficiency characteristics are in increasing demand. In this work, a flexible dielectric nanocomposite was developed by incorporating two components: cellulose nanofibrils (CNF) and recycled alum sludge, as the reinforcement phase and for enhancing the dielectric properties, in a bio-elastomer matrix. CNF and alum sludge were processed from waste materials which would otherwise be disposed to landfills. CNF were derived from water hyacinth, an invasive aquatic weed. Dried water hyacinth was treated using a simple and less energy-intensive process to obtain CNF. The alum sludge raw material was collected from a water treatment plant of Scottish Water and heat treated and refined before being used in preparing the composites. A biodegradable elastomer polydimethylsiloxane was used as the matrix and the nanocomposites were processed by casting the materials in petri dishes. The processed composites were characterised using scanning electron microscopy (SEM), thermogravimetric (TGA/DTG) and X-ray diffraction (XRD) analysis. The SEM micrographs illustrated CNF of approximately 20nm in diameter and alum sludge particles of approximately 200um in size. The TGA/DTG analysis results showed that a total mass of 46% has been removed when the sludge sample was heated up to 900°C. The XRD result showed that both quartz SiO2 and cubic γ-Al2O3 structures can be found in the sample that was heat treated up to 800°C. Other experiments also showed that the composites exhibit comparable mechanical and dielectric performances with other works in the literature. The work depicts that it is a sustainable practice of reusing such wastes in preparing flexible, lightweight and miniature dielectric materials that can be used for wearable technology applications
REPELLENCY OF UNRIPE FRUIT EXTRACTS FROM MELIA AZEDARACH L. ONTO RETICULITERMES FLAVIPES KOLLAR (ISOPTERA: RHINOTERMITIDAE)
Get PDFThe world widespread North American native subterranean termite, Reticulitermes flavipes Kollar (Isoptera: Rhinotermitidae) is one the major biotic agents which damage wood and a severe pest in several countries, where it causes important economic losses and has strong economic and social impacts. In urban environments this termite is a pest that damage houses and wooden structures, generating considerable losses. In central Chile there have been foci of infestation with a big expansion in the last years. This study evaluated in laboratory the repellence effect of extracts from Melia azedarach L. (Meliaceae) unripe fruits onto R. flavipes workers. The extracts were elaborated from two solvents, distilled water, and ethanol. The repellence effect was determined by a direct selection test, in which termites in contact with extract treated or untreated filter paper disks were evaluated, and the results were subjected to comparison paired tests. The extracts from the unripe fruits of M. azedarach were effective as a repellent against R. flavipes workers, with the greatest repellence at the greatest concentrations (3.0, 5.6, 7.4, and 5.4, 7.5, 10.1% w/v for the ethanol and water extracts, respectively), with stronger effects of the ethanol than the water extract. The results demonstrate the repellence effectiveness of these extracts from M. azedarach onto R. flavipes, thus unripe fruits of this tree species could be considered in biopesticide preparation for integrated management of this pest, which also requires field evaluation and economic study
AN INFLUENCE OF DUROC BREED IN PATERNAL POSITION ON CARCASS VALUE AND BUSINESS CLASSIFICATION BY SEUROP SYSTEM IN HYBRID PIGS
Get PDFThe aim of this study was to establish the impact of genotype on the carcass value of tested slaughter pigs of the hybrid combination (Czech Large White x Czech Landrace) x Duroc. The slaughtered test animals had an average slaughter weight of 119.68 ± 12.37 kg, the average lean meat portion of the carcasses established by classification was 56.20 ± 3.15 %, the average backfat thickness was 17.13 ± 4.10 mm. An average 3.63% of intramuscular fat in the longest back muscle was found in all the monitored slaughter pigs. The highest percentage of carcass pigs 54.3 % (398 animals) were classified in business class E with 57.51 ± 1.32% of lean meat portion, 115.15kg of an average slaughter weight. The lowest number of pigs (3 animals) were classified into business class O with 43.83% of lean meat portion. From results it is evident that with decrease of lean meat portion the slaughter weight of carcass pigs was growing. Carcass pigs classified into business class E reached the highest average price (32.86 CZK) per 1 kg of carcass body. A low negative correlation of r = -0.25, statistically conclusive on the level of importance of P < 0.05, was registered between slaughter weight and lean meat content. A very high negative correlation of r = -0.95, statistically conclusive on the level of importance of P < 0.001, was established between the thickness of backfat thickness and the lean meat portion
RESEARCH REGARDING PROBLEM WEEDS IN POTATO CROP IN SOUTHERN ROMANIA
Get PDFPotato (Solanum tuberosum L.) is considered to be one of the most competed crop by weeds. They may cause great losses, reducing the yield by 20-35%, consume large amounts of water and nutrients, decrease the effectiveness of treatments against diseases and pests and mechanized harvesting becomes difficult or impossible. The observations and assessments carried out aimed at deciding the problem weeds in the potato crop against which prevention and control measures must be effectively applied. The research targeted the monitoring and mapping of weeds in potato crops in Dâmbovița, Prahova and Călărași counties, in Romania. 30 determinations per hectare were conducted during 2020-2021, using the metric frame and the observations focused on density (number of plants/m2), participation (% in which each species is involved in the whole weed infestation), frequency (% in which each species was found in the observation points), class (pteridophytes, monocotyledonous, dicotyledonous) and the life span of each species (ephemeral, annual, biennial, weeds that can overwinter, perennials). The results obtained marked that the problem weeds in potato crops are usually perennial species difficult to control. Thus, among the dicotyledonous weeds, the species of Cirsium arvense, Sonchus arvensis and Convolvulus arvensis were identified as problem weeds, and among the monocotyledonous weeds, Sorghum halepense and Agropyron repens. Also in Lungulețu, due to the monoculture, the species Equisetum arvense, Ambrosia artemisiifolia and Symphitum officinalis created special problems for control, in Călărași county at Dâlga Cannabis ruderalis and in Prahova, Polygonum convolvulus and the Xanthium species. Even annual species, when they find favorable conditions for growth and development, are causing troubles: Chenopodium album, Polygonum aviculare, Echinochloa crus-galli. It has also been noted the increasing presence of invasive species: Ambrosia, Erigeron, Veronica, Xanthium
EFFECT OF ADJUVANTS ON THE RAINFASTNESS AND PERFORMANCE OF RIMSULFURON
Get PDFThe influence of a non-ionic surfactant and Renol on the performance and rainfastness of rimsulfuron was evaluated on two noxious broad-leaved weeds: redroot pigweed (Amarantus retroflexus) and lambsquarter (Chenopodium album). In first experiment, seven doses of rimsulfuron alone or in mixture with two adjuvants were applied to each weed species and subsequently subjected to 5mm of rain at 1, 2 and 4h after treatment (HAT) by using a rain simulator. In second experiment, the plants were sprayed with similar dosages and rain treatments of first semifield experiment, but with application of three non-iconic surfactant levels (0.04, 0.2 and 1L/ha). The results showed that the adjuvants did not improve the efficacy of rimsulfuron on Amaranthus retroflexus whereas it was completely efficient for Chenopodium album but the adjuvants enhanced both, the performance and the rainfastness, of rimsulfuron. Non-ionic surfactant was more efficient to improve herbicidal activity and rainfastness on both weed species. Increasing non-ionic surfactant concentration increased rimsulfuron activity around 10-fold for Amaranthus retroflexus compared to around 3-fold for Chenopodium album. Also reduced the rainfastness of rimsulfuron on Amaranthus retroflexus while improved the rainfastness of rimsulfuron on Chenopodium album