Slow-Release Nitrogen Fertilizers with Biodegradable Poly(3-hydroxybutyrate) Coating: Their Effect on the Growth of Maize and the Dynamics of N Release in Soil

Fertilizers play an essential role in agriculture due to the rising food demand. However, high input fertilizer concentration and the non-controlled leaching of nutrients cause an unwanted increase in reactive, unassimilated nitrogen and induce environmental pollution. This paper investigates the preparation and properties of slow-release fertilizer with fully biodegradable poly(3-hydroxybutyrate) coating that releases nitrogen gradually and is not a pollutant for soil. Nitrogen fertilizer (calcium ammonium nitrate) was pelletized with selected filler materials (poly(3-hydroxybutyrate), struvite, dried biomass). Pellets were coated with a solution of poly(3-hydroxybutyrate) in dioxolane that formed a high-quality and thin polymer coating. Coated pellets were tested in aqueous and soil environments. Some coated pellets showed excellent resistance even after 76 days in water, where only 20% of the ammonium nitrate was released. Pot experiments in Mitscherlich vegetation vessels monitored the effect of the application of coated fertilizers on the development and growth of maize and the dynamics of N release in the soil. We found that the use of our coated fertilizers in maize nutrition is a suitable way to supply nutrients to plants concerning their needs and that the poly(3-hydroxybutyrate) that was used for the coating does not adversely affect the growth of maize plants

Coping with stress and time management analysis in attorney office.

Diplomová práce je zaměřena na analýzu působení stresu na výkon pracovních činností, v advokacii. Hlavní cíl práce je zmapovat zdroje stresu, které snižují pracovní výkon advokátů a následné navrhnout možností zefektivnění plnění pracovních úkolů. Práce také poukazuje na to, jak se pracovníci snaží získat harmonii mezi pracovním a soukromým životem a také jaké k tomu využívají techniky. Za účelem realizace kvalitativního výzkum byl vytvořen polostrukturovaných rozhovor, aplikovaný na deseti respondentech. Rozhovory byly doslovně přepsány v programu Transcribe a následně kódované systémem MAXQDA. Získaná data byla vyhodnocena v rámci čtyř témat: stres a jeho vnímané dopady, syndrom vyhoření, work-life balance, možnosti zmírnění dopadů stresu. Diskuse výsledků v závěrečné části práce naznačuje propojení informací z rozhovorů s teoretickými poznatky. Z výzkumu plyne, že k největším zdrojem stresu výzkumná vzorek radí: časový tlak, množství práce, soudní jednání. K nejúčinnějším strategiím zvládání stresu uvažují: sport, setkávání s rodinou a hobby, asertivitu, určování priorit a sebeuvědomění.The diploma thesis focuses on the analysis of the effect of stress on the accomplishment of working tasks in advocacy. The main goal of the work is to map the sources of stress that reduce the work performance of lawyers and offers the possibilities of effective task fullfilment. Moreover, the work points out how employees try to reach harmony balance between work and private life, and what techniques and methods they choose to be effective. In order to carry out a qualitative research, a semi-structured interview was created and applied to ten respondents. The interviews were literally transcribed in the Transcribe program and subsequently coded by the MAXQDA 2020 system. The obtained data were evaluated according to four topics: stress and its perception, burnout syndrome, work-life balance, the possibility of stress elimination. The discussion of the results in the final part of the work suggests the connection between the information gained from interviews and the theoretical knowledge. The analysis shows that the research sample ranks among the biggest sources of stress as following: time pressure, amount of work, court proceedings. as for the most effective stress management strategies they mention: sports, family gatherings and hobbies, assertiveness, prioritization and self-awareness.Diplomová práca je zameraná na analýzu pôsobenia stresu na výkon pracovných činností, v advokácii. Hlavný cieľ práce je zmapovať zdroje stresu, ktoré znižujú pracovný výkon advokátov a následné navrhnúť možností zefektívnenia plnenia pracovných úloh. Práca taktiež poukazuje na to, ako sa pracovníci snažia získať harmóniu medzi pracovným a súkromným životom a tiež aké k tomu využívajú techniky. Za účelom realizácie kvalitatívneho výskum bol vytvorený pološtruktúrovaný rozhovor, aplikovaný na desiatich respondentoch. Rozhovory boli doslovne prepísané v programe Transcribe a následne kódované systémom MAXQDA. Získané dáta boli vyhodnotené v rámci štyroch tém: stres a jeho vnímané dopady, syndróm vyhorenia, work-life balance, možnosti zmiernenia dopadov stresu. Diskusia výsledkov v záverečnej časti práce naznačuje prepojenie informácii z rozhovorov s teoretickými poznatkami. Z výskum plynie, že k najväčším zdrojom stresu výskumná vzorka radí: časový tlak, množstvo práce, súdne rokovania. K najúčinnejším stratégiám zvládania stresu uvažujú: šport, stretávanie sa s rodinou a hobby, asertivitu, určovanie priorít a sebauvedomenie

Combined Sulfur and Peroxide Vulcanization of Filled and Unfilled EPDM-Based Rubber Compounds

The sulfur curing system, peroxide curing system and their combinations were applied for the cross-linking of unfilled and carbon black-filled rubber formulations based on ethylene-propylenediene-monomer rubber. The results demonstrated that the type of curing system influenced the course and shape of curing isotherms. This resulted in the change of curing kinetics of rubber compounds. The cross-link density of materials cured with combined vulcanization systems was lower than that for vulcanizates cured with the peroxide or sulfur system. Good correlation between the cross-link density as well as the structure of the formed cross-links and physical–mechanical characteristics of the cured materials was established. Both filled and unfilled vulcanizates cured with combined vulcanization systems exhibited a higher tensile strength and elongation at break when compared to their equivalents vulcanized in the presence of the peroxide or sulfur curing system. It can be stated that by proper combination of vulcanization systems, it is possible to modify the tensile behavior of vulcanizates in a targeted manner. On the other side, dynamical–mechanical properties were found not be significantly influenced by the curing system composition

The possibility of using the regranulate of a biodegradable polymer blend based on polylactic acid and polyhydroxybutyrate in FDM 3D printing technology

The study's main objective is the possible application of regranulate based on PLA and PHB bioplastics in the FDM 3D printing technique. The idea of using regranulate in the tested PLA/PHB biodegradable polymer blend can help to reduce the amount of plastic waste produced after defective or unwanted 3D printing from these types of materials suitable for 3D printing or after the industrial production of filaments with inadequate geometric parameters, which may help to economize raw material resources and, ultimately, lower the cost of studied polymer materials producing. The regranulate was added to the non-recycled biodegradable polymer blend with the same chemical composition in two different processes for making the filament for 3D printing. Based on testing the processing and utility properties of the processed regranulate materials, it was found that the regranulate partially degrades during multiple processing and thereby reduces the average molar mass and viscosity of the tested material during its processing. However, it was proven that despite the reduction of molecular characteristics after regranulate additions, it was possible to prepare the filaments by both investigated technologies of the regranulate addition and subsequently, it was possible to print such filaments using FDM 3D printing technology, even when the polymer blend contained a high content of regranulate. It was also proven that PLA/PHB materials containing regranulate exhibit comparable thermophysical and strength characteristics to the virgin PLA/PHB polymer blend

PLA/PHB-Based Materials Fully Biodegradable under Both Industrial and Home-Composting Conditions

In order to make bioplastics accessible for a wider spectrum of applications, ready-to-use plastic material formulations should be available with tailored properties. Ideally, these kinds of materials should also be "home-compostable" to simplify their organic recycling. Therefore, materials based on PLA (polylactid acid) and PHB (polyhydroxybutyrate) blends are presented which contain suitable additives, and some of them contain also thermoplastic starch as a filler, which decreases the price of the final compound. They are intended for various applications, as documented by products made out of them. The produced materials are fully biodegradable under industrial composting conditions. Surprisingly, some of the materials, even those which contain more PLA than PHB, are also fully biodegradable under home-composting conditions within a period of about six months. Experiments made under laboratory conditions were supported with data obtained from a kitchen waste pilot composter and from municipal composting plant experiments. Material properties, environmental conditions, and microbiology data were recorded during some of these experiments to document the biodegradation process and changes on the surface and inside the materials on a molecular level

PLA/PHB-based materials fully biodegradable under both industrial and home-composting conditions

In order to make bioplastics accessible for a wider spectrum of applications, ready-to-use plastic material formulations should be available with tailored properties. Ideally, these kinds of materials should also be "home-compostable" to simplify their organic recycling. Therefore, materials based on PLA (polylactid acid) and PHB (polyhydroxybutyrate) blends are presented which contain suitable additives, and some of them contain also thermoplastic starch as a filler, which decreases the price of the final compound. They are intended for various applications, as documented by products made out of them. The produced materials are fully biodegradable under industrial composting conditions. Surprisingly, some of the materials, even those which contain more PLA than PHB, are also fully biodegradable under home-composting conditions within a period of about six months. Experiments made under laboratory conditions were supported with data obtained from a kitchen waste pilot composter and from municipal composting plant experiments. Material properties, environmental conditions, and microbiology data were recorded during some of these experiments to document the biodegradation process and changes on the surface and inside the materials on a molecular level.IGA/FT/2022/006; Agentúra na Podporu Výskumu a Vývoja, APVV: 313011V336, APVV-20-0193, APVV-20-0256; European Regional Development Fund, ERDF: FCH-S-21-7553Internal Grant Agency [IGA/FT/2022/006]; Slovak Research and Development Agency [APVV-20-0256, APVV-20-0193]; European Regional Development Fund [313011V336]; Specific University Research Grant [FCH-S-21-7553