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Solubility of polypropylene in hydrocarbon solvents
Urbánková, Radka ; Kučera, Jaroslav (referee) ; Kratochvíla, Jan (advisor)
Polypropylene, on a mass-scale produced polyolefin, shows an excellent combination of end-use properties, eco-friendliness, easy recyclability, and a good processability by different technologies. Key structural parameters of polypropylene are its stereoregularity, molecular weight, and its distribution. A theoretical part of this work compiles a bibliographic search and an experimental part deals with extraction and solubility of polypropylene powder prepared on a highly active Ziegler-Natta polymerization catalyst. Extractions at a boiling point temperature of solvents (pentane - hexane - cyclohexane - hex-1-ene - benzene - heptane - octane - ethylbenzene) resulted in a progressive increase of extracted portions with temperature of extraction. Solvents used within this work were characterised by their physical properties, and steric and electronic parameters such as molecular weight, density, boiling point temperature, dipole moment, refractive index, and Hildebrand´s solubility parameter. Extraction PP at a constant temperature 36°C (boiling point of pentane) at a saturated vapour pressure in a series of hydrocarbon solvents (pentane – hexane – heptane – octane) resulted in practically the same results. Boiling octane extractable fraction at a temperature 36°C was nearly 100 % higher than fractions extracted by the other solvents. The origin of this phenomenon has not been revealed. Polypropylene solubility was determined by a complete dissolving the sample at 140°C in a series of aliphatic and aromatic solvents (pentane - hexane - cyclohexane - hex-1-ene - benzene - heptane - octane - toluene - ethylbenzene - o-xylene - m-xylene - p-xylene - decalin - chlorbenzene - 1,2-dichlorbenzene), followed by cooling the solution down to a laboratory temperature, and separating a soluble fraction, and an insoluble one. The stereoregularity of soluble fractions was characterised by a 13C NMR method, the crystallinity by a DSC method, and a molecular weight distribution by a GPC method. As a result, polypropylene solubility decreases with increasing the Hildebrand solubility parameter of the solvent that corresponds with theoretical expectations. Moreover, PP solubility correlates strongly with a refractive index, and a density of solvent.
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Face Features Extraction Methods
Adamček, Ľubomír ; Orság, Filip (referee) ; Goldmann, Tomáš (advisor)
The face has been one of the most attractive available human biometries for a long time due to it's easy and convenient way to obtain it. Possibilities of it's utilization are broad - from security, through monitoring up to enternainment industry. This work presents the domain of face biometry and analyses 3 extraction methods of facial features - PCA, LBP and HOG. A part of this work is also an efficient implementation of these algorithms including GUI designed to experiment with this implementation and to evaluate its performance on a set of images capturing people in various conditions.
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Sulfonamide residues in sediment and sludge from wastewater treatment plants
Chaloupková, Petra ; Lacina, Petr (referee) ; Vávrová, Milada (advisor)
The aim of the bachelor’s thesis was a method optimalization for extraction of sulfonamides from sediment and sewage sludge samples from wastewater treatment plants. This optimized method was used for analyzing sulfonamides in real soil and sewage sludge samples. Antibiotics are commonly used as a prevention and medicament for human and animals. Drugs and their residues enter to wastewater treatment plants within excrements and then they can be a part of sewage sludge or they can occur in treated water. It can also enter environment as a part of soils or sediments. Three extraction methods were chosen for optimizing; a pressurized solvent extraction, a microwave-assisted extraction and an ultrasonic extraction. Extracts were cleaned by solid phase extraction and analysed by liquid chromatography with diode array detector.
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Zavedení a optimalizace metodiky pro stanovení lipofilních a hydrofilních vitamínů v biologických vzorcích
Kalábová, Vendula
The main scope of this diploma thesis are the methods used for building vitamins, especially priorizing chromatographic methods. You can also find the characteristics of vitamins dissolvable in fat and water, their physiological meaning, daily use, presence in foodstuffs and methods, which are suitable for their analysis. The experimental part describes the sample preparation, their vitamin extraction methods, the requierements for chromatographic assessions, methods of qualitative and quantitative evaluation of chromatographs with the focus on the calibration curve method. The work also puts an emphasis on establishing the limit of detection and the limit of quatification, and determining the lipophilic vitamins in matrices rich of these vitamins using the method of HPLC.
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Face Features Extraction Methods
Adamček, Ľubomír ; Orság, Filip (referee) ; Goldmann, Tomáš (advisor)
The face has been one of the most attractive available human biometries for a long time due to it's easy and convenient way to obtain it. Possibilities of it's utilization are broad - from security, through monitoring up to enternainment industry. This work presents the domain of face biometry and analyses 3 extraction methods of facial features - PCA, LBP and HOG. A part of this work is also an efficient implementation of these algorithms including GUI designed to experiment with this implementation and to evaluate its performance on a set of images capturing people in various conditions.
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Sulfonamide residues in sediment and sludge from wastewater treatment plants
Chaloupková, Petra ; Lacina, Petr (referee) ; Vávrová, Milada (advisor)
The aim of the bachelor’s thesis was a method optimalization for extraction of sulfonamides from sediment and sewage sludge samples from wastewater treatment plants. This optimized method was used for analyzing sulfonamides in real soil and sewage sludge samples. Antibiotics are commonly used as a prevention and medicament for human and animals. Drugs and their residues enter to wastewater treatment plants within excrements and then they can be a part of sewage sludge or they can occur in treated water. It can also enter environment as a part of soils or sediments. Three extraction methods were chosen for optimizing; a pressurized solvent extraction, a microwave-assisted extraction and an ultrasonic extraction. Extracts were cleaned by solid phase extraction and analysed by liquid chromatography with diode array detector.
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Solubility of polypropylene in hydrocarbon solvents
Urbánková, Radka ; Kučera, Jaroslav (referee) ; Kratochvíla, Jan (advisor)
Polypropylene, on a mass-scale produced polyolefin, shows an excellent combination of end-use properties, eco-friendliness, easy recyclability, and a good processability by different technologies. Key structural parameters of polypropylene are its stereoregularity, molecular weight, and its distribution. A theoretical part of this work compiles a bibliographic search and an experimental part deals with extraction and solubility of polypropylene powder prepared on a highly active Ziegler-Natta polymerization catalyst. Extractions at a boiling point temperature of solvents (pentane - hexane - cyclohexane - hex-1-ene - benzene - heptane - octane - ethylbenzene) resulted in a progressive increase of extracted portions with temperature of extraction. Solvents used within this work were characterised by their physical properties, and steric and electronic parameters such as molecular weight, density, boiling point temperature, dipole moment, refractive index, and Hildebrand´s solubility parameter. Extraction PP at a constant temperature 36°C (boiling point of pentane) at a saturated vapour pressure in a series of hydrocarbon solvents (pentane – hexane – heptane – octane) resulted in practically the same results. Boiling octane extractable fraction at a temperature 36°C was nearly 100 % higher than fractions extracted by the other solvents. The origin of this phenomenon has not been revealed. Polypropylene solubility was determined by a complete dissolving the sample at 140°C in a series of aliphatic and aromatic solvents (pentane - hexane - cyclohexane - hex-1-ene - benzene - heptane - octane - toluene - ethylbenzene - o-xylene - m-xylene - p-xylene - decalin - chlorbenzene - 1,2-dichlorbenzene), followed by cooling the solution down to a laboratory temperature, and separating a soluble fraction, and an insoluble one. The stereoregularity of soluble fractions was characterised by a 13C NMR method, the crystallinity by a DSC method, and a molecular weight distribution by a GPC method. As a result, polypropylene solubility decreases with increasing the Hildebrand solubility parameter of the solvent that corresponds with theoretical expectations. Moreover, PP solubility correlates strongly with a refractive index, and a density of solvent.
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Comparison of Extraction Methods for Isolation of 20-Hydroxyecdysone from Leuzea carthamoides
Machalová, Zdeňka ; Sajfrtová, Marie ; Sovová, Helena ; Bártlová, Milena
This work is focused on the extraction of 20-HE from roots and seeds of Leuzea carthamoides using SFE, PLE and Soxhlet extraction. The SFE and PLE conditions (pressure, temperature, type and concentration of solvent, extraction time) were optimized to improve extraction yields and concentrations of 20-HE in extracts. These methods were compared with a conventional Soxhlet-type extraction. The SFE experiments were carried out at temperatures from 40°C to 60°C, pressures from 30 to 65 MPa and with addition of 5-20% of co-solvent (ethanol, methanol and acetone). PLE with ethanol, methanol and acetone was made at temperatures from 70°C to 100°C, pressures from 7 to 20 MPa and extraction time from 5-15 min. Soxhlet extraction with ethanol was used to evaluate the total content of 20-HE in roots and seeds. The concentration of 20-HE in extracts was determined by HPLC.
Fulltext: content.csg -  PDF
Plný tet: SKMBT_C22014082908303 - PDF
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Screening Study of Influence of Selected Alkaloids from Eschscholtzia Californica Cham. (Papaveraceae) on Human Erythrocytal Acetylcholinesterase
Opletal, L. ; Cahlíková, L. ; Dohnal, V. ; Kurfürst, Milan ; Schraml, Jan ; Jun, D. ; Musilová, L. ; Doležal, J. ; Jahodář, L.
Primary extract was prepared by extraction of whole plant with 95% EtOH and then secondary extracts were made. From ethereal extract (pH 9-10) benzofenantridin alkaloids were separated, remaining tertiary bases were divided according to solubility of their chlorides in chloroform; thus, phenolic and non-phenolic alkaloids were obtained from each fraction.
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