Assessment of the effect of formaldehyde resin monomers on the environment

V současné době jsou každoročně produkovány tisíce nových látek jejichž vliv na životní prostředí není znám. Mnohé z těchto látek jsou záměrně nebo lidskou nedbalostí vypouštěny do přírody, kde mohou být transportovány a degradovány různými mechanismy. Tyto látky mohou mít vliv na různé druhy organismů a také na člověka. Z tohoto důvodu narůstají celosvětově problémy se znečišťováním všech složek životního prostředí. Tato diplomová práce posuzuje vliv monomerů formaldehydových pryskyřic, které jsou běžně komerčně vyráběny, na životní prostředí. Pro účely ekotoxikologického hodnocení vzorků melamin-formaldehydové a močovino-formaldehydové pryskyřice byly zvoleny tři testy: akutní imobilizační test na perloočkách Daphnia magna, akutní test s luminiscenčními bakteriemi Vibrio fischeri a akutní test inhibice spotřeby kyslíku aktivovaným kalem. Pro komplexnější posouzení vlivu těchto látek na životní prostředí byla také testována biodegradabilita. Obě testované látky vykazovaly efekt na testovací organismy, avšak z výsledků testů ekotoxicity a biodegradability můžeme usuzovat, že by tyto látky neměly představovat významné riziko pro životní prostředí.Thousand of new substances with unknown environmental effect are produced and used daily. Many of them are deliberately or by negligence released and deposited into the environment where they could undergo different transport and degradation mechanisms. They are able to affect different types of organisms, as well as humans. For this reason, the awareness of the problems, associated with pollution of all environmental compartments is growing. The environmental impact of monomer formaldehyde resins, which are produced for commercial use, on the environment were studied in this research. For the purposes of ecotoxicological evaluation samples of melamine-formaldehyde and urea-formaldehyde resin were chosen and three toxicity tests were run: acute test with measurement of inhibition of the mobility of Daphnia magna, the acute test with luminescent bacteria Vibrio fischeri and acute test with measurement of inhibition of oxygen consumption by activated sludge. For more comprehensive assessment of the impact of these substances on the environment, biodegradability was also determined. Both tested substances showed minor hazardous impact to testing organisms and it can be concluded, that these substances should not present a significant risk to the environment.

Evaluation of the business plan of the selected economic subject

103 s., 8 s. příl. :obr., tab., grafy +CD ROMCílem diplomové práce s názvem ''Vyhodnocení projektového záměru vybraného ekonomického subjektu'' je připravit a vyhodnotit veřejný projekt ve vazbě na inovace v oblasti provozu kina. Vybraným ekonomickým subjektem je organizační složka města Chlumec nad Cidlinou, a to Městské kulturní středisko Klicperův dům. Kulturní zařízení slouží jako kino, divadlo a výstavní prostory. Vzhledem k zásadním změnám v distribuci filmů, bylo nutné vyřešit, jak dále naložit s městským kinem. Diplomová práce uvádí rešerše odborné literatury týkající se projektového řízení se zaměřením na veřejný sektor a řízení rozpočtu města. Dále práce analyzuje stávající situaci v kinematografickém průmyslu a zabývá se analýzou technického stavu ekonomického subjektu. Na základě toho předkládá možnosti řešení situace změny technologie pro kino a pomocí metod ekonomického hodnocení vybírá nejvhodnější variantu projektu. V závěru autorka diplomové práce navrhuje konkrétní projekt pro vybrané řešení a stanovuje jeho realizační plán

Novel Protocol for Acute In Situ Ecotoxicity Test Using Native Crustaceans Applied to Groundwater Ecosystems

Current standardized laboratory test protocols use model species that have limitations to accurately assess native species responses to stressors. We developed and tested a novel acute in situ protocol for testing field-collected organisms. We used Asellus aquaticus and NaCl as a reference toxicant to test for the effects of location (laboratory vs. in situ), medium (synthetic vs. field water), substrate (presence vs. absence), and protocol replicability. We further tested the protocol using groundwater-adapted isopods: Proasellus assaforensis for the effect of location, P. cavaticus of medium and P. lusitanicus of substrate. Our results showed that A. aquaticus’ lethality obtained with the novel acute in situ protocol did not significantly differ from those from laboratory testing. However, laboratory tested P. assaforensis showed a higher sensitivity, suggesting that its acclimation to laboratory conditions might have pernicious effects. A. aquaticus and P. cavaticus showed a higher mortality using synthetic medium in situ and under laboratory conditions, which overestimated the stressor’s effect. Besides, substrate use had no significant effect. The novel acute in situ protocol allows the use of native species under realistic scenarios. It is particularly well adapted for assessing the risk of groundwater ecosystems but it can be applied to a wide range of ecosystems.info:eu-repo/semantics/publishedVersio

Biodegradability study of active chitosan biopolymer films enriched with Quercus polyphenol extract in different soil types

One of the recent trends within the circular economy is the development of materials derived from food processing waste and their utility as an alternative to plastic packaging. In this context, the study aims to evaluate biological causes of deterioration or degradation of chitosan-based films with and without incorporated natural Quercus polyphenol extract in three different types of soils (industrial compost, commercial garden soil, and soil from a vineyard). Degradation and active properties deterioration was followed by measurement of the loss of mass of tested active films for 14 days, and it was accompanied by other analytical techniques such as measurement of polyphenolic content, FT-IR analysis, and SEM examination of the packaging morphology. The results showed that chitosan-based film properties deteriorate in less than 3 days followed by biodegradation in all tested soils after 14 days. Films with incorporated Quercus polyphenol extract undergo deterioration of active properties in compost and garden soil in 6 days, while the fractionation and degradation process has not been complete in the vineyard soil during the 14 days. Furthermore, it has also been revealed that the addition of water to the soil decreased the rate of active chitosan film biodegradation in the terrestrial environment

Laser-based techniques: Novel tools for the identification and characterization of aged microplastics with developed biofilm

Microplastics found in the environment are often covered with a biofilm, which makes their analysis difficult. Therefore, the biofilm is usually removed before analysis, which may affect the microplastic particles or lead to their loss during the procedure. In this work, we used laser-based analytical techniques and evaluated their performance in detecting, characterizing, and classifying pristine and aged microplastics with a developed biofilm. Five types of microplastics from different polymers were selected (polyamide, polyethylene, polyethylene terephthalate, polypropylene, and polyvinyl chloride) and aged under controlled conditions in freshwater and wastewater. The development of biofilm and the changes in the properties of the microplastic were evaluated. The pristine and aged microplastics were characterized by standard methods (e.g., optical and scanning electron microscopy, and Raman spectroscopy), and then laser-induced breakdown spectroscopy (LIBS) and laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) were used. The results show that LIBS could identify different types of plastics regardless of the ageing and major biotic elements of the biofilm layer. LA-ICP-MS showed a high sensitivity to metals, which can be used as markers for various plastics. In addition, LA-ICP-MS can be employed in studies to monitor the adsorption and desorption (leaching) of metals during the ageing of microplastics. The use of these laser-based analytical techniques was found to be beneficial in the study of environmentally relevant microplastics

Understanding How Microplastics Affect Marine Biota on the Cellular Level Is Important for Assessing Ecosystem Function: A Review

Plastic has become indispensable for human life. When plastic debris is discarded into waterways, these items can interact with organisms. Of particular concern are microscopic plastic particles (microplastics) which are subject to ingestion by several taxa. This review summarizes the results of cutting-edge research about the interactions between a range of aquatic species and microplastics, including effects on biota physiology and secondary ingestion. Uptake pathways via digestive or ventilatory systems are discussed, including (1) the physical penetration of microplastic particles into cellular structures, (2) leaching of chemical additives or adsorbed persistent organic pollutants (POPs), and (3) consequences of bacterial or viral microbiota contamination associated with microplastic ingestion. Following uptake, a number of individual-level effects have been observed, including reduction of feeding activities, reduced growth and reproduction through cellular modifications, and oxidative stress. Microplastic-associated effects on marine biota have become increasingly investigated with growing concerns regarding human health through trophic transfer. We argue that research on the cellular interactions with microplastics provide an understanding of their impact to the organisms’ fitness and, therefore, its ability to sustain their functional role in the ecosystem. The review summarizes information from 236 scientific publications. Of those, only 4.6% extrapolate their research of microplastic intake on individual species to the impact on ecosystem functioning. We emphasize the need for risk evaluation from organismal effects to an ecosystem level to effectively evaluate the effect of microplastic pollution on marine environments. Further studies are encouraged to investigate sublethal effects in the context of environmentally relevant microplastic pollution conditions

REPORTED CASES OF SCABIES IN KLATOVY REGION FROM 1961 TO 2010

Title of this bachelor thesis is "Reported cases of scabies in Klatovy district from 1961 to 2010". Its theoretical part deals with a description of scabies as an itchy skin parasitic disease, which is still an actual issue worldwide. In the Czech Republic it is the fourth most common infectious disease. This piece of work is focused on anatomy and physiology of skin, morphology of skin changes, etiology and epidemiology of scabies, its clinical image, diagnosis, cure, possible complications and prevention. The practical part composes of quantitative research, for which the method of secondary document analysis was chosen. The data was selected and processed from diaries of infectious diseases and from documents of epidemiological investigation of District Hygiene Station of Pilsen Region - Regional Establishment in Klatovy and from National Health Institute in Prague. The main source of demographic data was public database of Czech statistical office. This part makes a comprehensive overview of the occurrence of reported cases of scabies in Klatovy district in period from 1961 to 2010. The file described on the basis of the annual incidence (per 100 000 inhabitants). Compare the structure of the file (1961 ? 1985 a 1986 ? 2010). I describe a set of terms of age, sex, seasonality and the profession. Comparable data were compared to data for the Czech Republic. Possible causations of different trend in annual incidence of reported cases of scabies in Klatovy district and in the Czech Republic are discussed. The main aim of this work was to get an overview of reported cases of scabies in Klatovy district from 1961 to 2010, and subsequently to compare data of those reported cases with all data available in the Czech Republic, and to make a description of occurrence of reported cases of scabies in Klatovy district in the same period of time, according to age, sex, seasonality and profession. This bachelor thesis can be used as a source of information on scabies morbidity in Klatovy district and the Czech Republic by both professional and laic public

Aquatic Biofilms—Sink or Source of Microplastics? A Critical Reflection on Current Knowledge

The scientific understanding regarding sources, occurrence, and effects of microplastics in the aquatic environment has advanced rapidly, leaving some meaningful knowledge gaps virtually untouched. One of them is the interactions of microplastics and biofilms, microbial communities ubiquitous in aquatic ecosystems and fundamental for a range of ecosystem‐level processes. It is evident that biofilms can quickly develop on the microplastic surface and consequently change particle properties and, as such, its fate and ecotoxicity. Moreover, microplastics interact with ubiquitous biofilms that are developed on any surfaces in aquatic ecosystems. Although the knowledge about these interactions is at best limited, it is expected that microplastics attach to the water–biofilm interface or penetrate the biofilm matrix. Microplastics can accumulate and ab‐ or adsorb to those biofilms where they are subjected to transformation processes such as fragmentation. Thus, biofilms may function as a sink. Changes in environmental conditions may, however, stress biofilms initiating their dieback and microplastic release, which could turn biofilms into a source of microplastics. We argue that the accumulation and release dynamics are a largely overlooked but potentially important piece to the puzzle that is a comprehensive understanding of microplastic fate in the environment and thus under the influence of multiple interacting factors. Environ Toxicol Chem 2022;41:838–843. © 2021 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.Slovenian Research Agenc

Draft of spatial arrangement of the production floor

Bakalářská práce se zabývá návrhem nového prostorového uspořádání. V teoretické části jsou představeny teoretické poznatky získané studiem odborné literatury zaměřené na skladování, manipulaci s materiálem a prostorové uspořádání pracoviště. Úvodní část práce je věnována historii a představení firmy. Následuje analýza současného stavu firmy z hlediska její výrobní činnosti, skladového hospodářství a současného dispozičního uspořádání strojů. Nejdůležitější částí jsou samotné návrhy na zefektivnění výroby z hlediska prostorového uspořádání.ObhájenoThis bachelor deals with a proposal of a new spatial arrangement. Theoretical part of the thesis presents a literature review of technical literature focused on the storage, material manipulation and spatial arrangement of workplace. Practical part covers history of the company and its present management. Followed by analysis of current structure of company from the production point of view, and also current position of the machines. The most important part is the proposals for more effective production in terms of spatial organization