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Mechanical properties and structure of blends of recycled polyethylene with linear low density polyethylene
Kocandová, Jana ; Poláček, Petr (referee) ; Bálková, Radka (advisor)
Recycled material produced during three months from packing polyethylene foils coming from three suppliers was analysed together with one recycled material under complaint from the point of melt flow index (MFI), composition and mechanical properties. The addition of linear low density polyethylene (LLDPE) into the recycled material was studied as well. It was measured melt flow index (MFI), Differential scanning calorimetry (DSC) together with Thermogravimetry methods were used to determine composition. Selected materials were pressed to obtain films with the thickness of 1 mm to determine tensile properties. Recycled materials contained 40–65% LLDPE, small amount of polypropylene as well as chalk. The content of LDPE and LLDPE varied within one supplier and thus mechanical properties did. The results showed the difference in quality of PE films separation among all suppliers. The problems with workability of material under complaint were caused by the material composition – the amount of LLDPE predominated. The addition of LLDPE into the recycled material in the range of 5–20 % increased MFI by 13-78%. Mechanical properties of blends rich in LLDPE were similar to those of clear LLDPE. The presence of LDPE influenced more markedly only the strength to break. The blends of LDPE and LLDPE were evaluated as immiscible but with high affinity of the components with increasing contend of LLDPE. No material was chemically degraded. The methods commonly performed in manufacture, especially MFI, are not able to differentiate LDPE form LLDPE – recommended is DSC.
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Mechanical properties and structure of blends of recycled polyethylene with linear low density polyethylene
Kocandová, Jana ; Poláček, Petr (referee) ; Bálková, Radka (advisor)
Recycled material produced during three months from packing polyethylene foils coming from three suppliers was analysed together with one recycled material under complaint from the point of melt flow index (MFI), composition and mechanical properties. The addition of linear low density polyethylene (LLDPE) into the recycled material was studied as well. It was measured melt flow index (MFI), Differential scanning calorimetry (DSC) together with Thermogravimetry methods were used to determine composition. Selected materials were pressed to obtain films with the thickness of 1 mm to determine tensile properties. Recycled materials contained 40–65% LLDPE, small amount of polypropylene as well as chalk. The content of LDPE and LLDPE varied within one supplier and thus mechanical properties did. The results showed the difference in quality of PE films separation among all suppliers. The problems with workability of material under complaint were caused by the material composition – the amount of LLDPE predominated. The addition of LLDPE into the recycled material in the range of 5–20 % increased MFI by 13-78%. Mechanical properties of blends rich in LLDPE were similar to those of clear LLDPE. The presence of LDPE influenced more markedly only the strength to break. The blends of LDPE and LLDPE were evaluated as immiscible but with high affinity of the components with increasing contend of LLDPE. No material was chemically degraded. The methods commonly performed in manufacture, especially MFI, are not able to differentiate LDPE form LLDPE – recommended is DSC.
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The Personality Disabled Social Worker
KOCANDOVÁ, Jana
In the first part of the thesis I address the theoretical basis of the issue of social work, lifelong learning, the burnout syndrome and the ethical code of a social worker. Of health social worker help the others who face a problematic situation. They help people in order to enable them to exist and function in interaction with their social environment at a socially appreciated level. In the practical part of the thesis, the objective of the research that I set myself was to ascertain whether the health social workers have the competences to exercise their profession and what techniques they use to prevent the burnout syndrome. I decided for a written anonymous questionnaire to collect the data. The research was conducted in health and social facilities in 8 regions of the Czech Republic. 160 questionnaires were distributed altogether. The total research set consisted of 106 respondents. I examined two hypotheses. The first one was: A majority of health social workers does not have sufficient education to exercise the profession. The second one was: Of health social workers realize the risks of the burnout syndrome.
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Canisterapie practicing in České Budějovice.
KOCANDOVÁ, Jana
Canistherapy is one of the forms of zootherapy. It is a part of a compact rehabilitation, which serves to the support of psychosocial health of human beings of any age, where is used the presence of a dog. The goal of the bachelor thesis is to collect information about a process of canistherapy.
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