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Poly(methylene blue) modified carbon based electrodes for the determination of sulfhydryl-containing compounds
Zlámalová, Magda ; Janda, Pavel ; Nesměrák, K.
This research presents the study of electrochemical polymerization of phenothiazine derivative, methylene blue (MB). Electrochemical pro perties and analytical application of resulting electrocatalytically active poly(methylene blue) (pMB) have been investigated. Three various carbon-based substrates: basal plane of highly oriented pyro lytic graphite (HOPG), pencil graphite electrode (PGE) and carbon fibre micro electrode (CFE) have been used. Aforementioned electrodes modified with the polymer (HOPG/pMB, PGE/pMB and CFE/pMB) have been prepared by potential cycling in aqueous electrolyte solution containing dissolved monomeric methylene blue. Electrocatalytic activity of three developed electrode systems towards hydrogen sulphide has been compared. Developed electrodes have been further investigated as potential sensors for sulfhydryl-containing compounds.
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Strucutre and disturbance regime of the natural spruce mountain forests in the Fagaras Mts. in Romania
Sýkora, Ondřej ; Svoboda, Miroslav (advisor) ; Janda, Pavel (referee)
There is a large natural disturbance in spruce stands at the present moment in many European countries. Therefore understanding of the long-term natural processes and the impact of disturbances on the structure have a key role in the management of spruce forests. For this purpose, we have studied the structure and the historical regime mountains, which is one of the best preserved forest ecosystems in the Europe. Between 2011 and 2013 years we have founded nearly 50 research spots in the four valleys where we collected data on the structure of the forest. For purposes of reconstruction of disturbances history samples from almost 3 500 individuals of Norway spruce (Picea Abies) were taken. Data were analyzed with dendrochronological methods and descriptive statistics. Partial synchronization of disturbances with the valleys and the subsequent rise in the regeneration was detected, which shows the influence of disturbances evoked by wind and then, probably, by the increasing population of bark beetles. We noticed the importance of the disturbances (weak - strong), which directly influences the structure and creates the mosaic diversity of vegetation. The history of the oldest areas goes back for 400 years, and for the youngest - for 100 years. The volume of the deadwood in the valleys was approximately 135 m3. Overall, on the investigated spots 1380 individuals of regeneration with dominating recovery of Norway spruce (Picea Abies) were recorded, with the proportion of 76 %.
Our results show that the disturbances are partially synchronized with the landscape level and also on the level of each valley, and have a major impact on the structure and dynamic of the forest. Natural disturbances are the main factor affecting the natural regeneration of spruce forests.
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History and presence of oak stands in Europe
Kloučková, Dominika ; Bače, Radek (advisor) ; Janda, Pavel (referee)
The aim of this work is to evaluate historical human impact on the expansion of European oak stands in the past through scientific publications and to find existing limitations that affect the oak recovery ability. The European historical forest is characterized by coppicing, of which origins date back to the Neolithic period. The coppice featured vegetative renewal, in the coppice with standards there were left standards of the generative origin, often oaks. Both forms have a very long tradition in European countries. People used the sprouting capacity and the quick regeneration of oak especially for construction purposes and their need for firewood. Acorns secured the source of food for pig farming. Based on for example the ring width or pollen analysis, current methods of research permit to assess the impact of active management on the oak stands and outline the structure of primeval forests. It turned out that coppicing has a positive effect on the increment of oak standards and that the open landscape with a rich diversity of species, which features a picture of a primeval forest, was always maintained especially by a man starting forest fires. Since the mid-20th century, it was gradually transferred to the high shape of the wood, which favors generative way to recovery, and thus monocultures of often coniferous trees are created. Oak is currently health endangered tree species and its recovery is negatively affected by grazing deer (browsing), the influence of abrupt climate change, weed, pathogenic fungi of the genus Phytophthora, oak powdery mildew (Microsphaera alphitoides), tracheomycotic diseases or larvae of winter moth (Operophtera Brumata) and green oak moth (Tortrix viridana). Finally, it is inappropriately selected management that is not based on the rich history of this species and doesn´t preserve its characteristic natural properties.
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Mixed forests and its practical use for forest management
Adamec, Jiří ; Janda, Pavel (advisor) ; Mrhalová, Hana (referee)
This Bachelor thesis focuses primarily onmixed forests and their practical use for forest management. It deals with forests both in Central Europe and the Czech Republic. Issues related to forests and the effect of different influences on them, are the subject of a variety of scientific papers. Obtained knowledgeabout mixed forests could help us better understand the increasingly emerging climate change. The main factors are temperature, rapidly changing in the recent years, and the changes in average total annual precipitation and varying amounts of gases in the air. The actual composition of the mixed forests and the individual characteristics of trees have to be also taken into account. An increased incidence of pests and diseases of trees and proliferating pests that may be affected both by climate change ortree species in the stands. This paper presents the possible conversion of spruce monocultures into mixed stands It contains a lot of knowledge from various scientific papers whose main points are summarized in a form of literature review and could lead to improved conditions of our forests.
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Dynamics and stand structure of the primary mountain mixed forests in Temperate Zone (Europe)
Votava, Martin ; Janda, Pavel (advisor) ; Lábusová, Jana (referee)
The bachelor thesis mainly deals with dynamics and structure of mountain mixed forests in
the temperate zone of Europe. It provides complex view at disturbance regimes and its effect on forest ecosystems. European mixed forests dominated by Fagus sylvatica, Abies alba and Picea abies are characterized by variable wind disturbances. Wide range of severity classes and spatial patterns of disturbances influence these ecosystems, consequently, it has important influence on species composition and developmental trajectories. Partly, the bachelor thesis deals with the perspectives of forest management in context of biodiversity and climate change. The bachelor thesis was compiled as literature review from many national and international results of scientific studies. Main aim of the work was to summarize general principles about these ecosystems.
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Disturbance history of the primary mountain mixed forests in Temperate Zone (Europe)
Komín, Stanislav ; Janda, Pavel (advisor) ; Bače, Radek (referee)
This paper is about structure and disturbance regime of mountain mixed forests in location Šrámkova dolina, which is in Tatras national park. Except this, thesis also informs about problems which are in mountain mixed forests. Forest dynamic were monitored od 14 permanent plots, which were in the line polygon, every plot takes 1000 m2. Study is based on the structural data of the type, thicknes and age structure and this data were put into dendroecological analys, which shows releases during the growth. Based on results, we can say that most trees strarts their growth in forests gap, and most of trees did not detect release. Šrámkova dolina were formed by gew several wind disturbances, biggest impact had few disturbances between year 1834 and 1845, this event strongly affected regenerations between decades 1845 and 1885. In the Europe temperate zone are mountain forests mostly affected by wind adn bark beatle, but in mixed forests are damage caused by bark beatle smaller. Small canopy destruction caused by small disturbance salso play very important role in forests dynmic here.
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Disturbance history of the primary mountain spruce forests in Temperate Zone (Europe)
Hanousek, Jan ; Janda, Pavel (advisor) ; Čada, Vojtěch (referee)
This thesis is about the development and structure of mountain Norway spruce forest in location Koprová dolina, which is part of Tatras national park. Forest dynamic were monitored on 13 permanent research plots, every plot takes 1000 m2. Study was based on the analyses of the thicknes and age structure and the dendrochronologal analysis, which detects releases during growth. Based on results we confirmed that locations have character of natural forests, these locations are formed by strong and big-scale disturbances, but also by disturbances of medium and small strenght and scale. Results are similar with other papers and historical texts, which describes disturbances events in Koprová dolina.
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Species requirements on the structure of European mountain Norway spruce forest
Suderová, Natálie ; Čada, Vojtěch (advisor) ; Janda, Pavel (referee)
The aim of this bachelor thesis is to summarize conteporary studies about the biological and ecological characteristics and demands of the plant, animal and fungi species inhabiting montane Norway spruce forests, especially those of the red-list species.
An extensive systematic review was conducted as a part of this study, with a systematic research of Web of Science database, finding science studies containing key words referencing to high montane spruce forest and biotope demands of organisms. Out of a total 475 studies found in a Web of Science database, 57 studies were chosen with objectiv criteria, and 44 were cited in the bachelor thesis.
Bachelor thesis chapters were dedicated to functional groups of organisms, as often found in studied literature, i.e. vascular plants, fungi, lichenes and epiphytes, arthropods and nematodes, birds, mammals and amphibians.
Several structural key elements were found to be significant for the abundance, biodiversity and species composition of organisms inhabiting high montane spruce forest. These key elements are forest structure, deadwood, admixture tree species and environment pollution.
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Poly(Methylene Blue) Modified Carbon-based Electrodes for Electrochemical Detection of Hydrogen Sulfide
Zlámalová, Magda ; Janda, Pavel ; Nesměrák, K.
A comparative electrochemical study has been carried out of the electropolymerization of phenothiazine derivative, methylene blue (MB). Electrochemical properties of resulting electrocatalytically active methylene blue polymer (pMB) have been studied on three various carbon-based substrates: basal plane of highly oriented pyrolytic graphite (HOPG), pencil-graphite electrode (PGE) and carbon fibre micro electrode (CFE). Electrodes modified with the polymer (HOPG/pMB, PGE/pMB and CFE/pMB) have been prepared by potential cycling in aqueous electrolyte solution containing dissolved monomeric methylene blue. Electrocatalytic activity of three developed electrode systems towards hydrogen sulphide has been compared. Developed electrodes have been further investigated as potential sensors for sulfhydryl-containing compounds.
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Electrochemical Characterization of Poly(methylene Blue) Modified Graphite Electrodes
Zlámalová, Magda ; Janda, Pavel ; Nesměrák, K.
This work deals with electrochemical study of methylene blue (MB) polymerization as well as characterization of deposited conductive film on basal plane highly oriented pyrolytic graphite (HOPG) and pencil-graphite electrode (PGE). Poly(methylene blue) modified electrodes (HOPG/pMB and PGE/pMB) have been prepared by potential cycling in aqueous electrolyte solution containing methylene blue monomer. It has been found that electrochemical properties and electrocatalytic activity of deposited film are greatly influenced by the type of electrode substrate. Developed electrodes have been further investigated as potential sensors for sulfhydryl-containing compounds.
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