Metallurgical fundamentals of foundry production of high silicon content spheroidal graphite cast iron casting

katedra: KSP; přílohy: 1 CD ROM; rozsah: 45 sThe thesis summarizes previous knowledge about production of castings made of spherodial graphite cast iron. Furthermore this thesis is engaged in studying of influence of technological parameters and chemical composition on mechanical properties of specimen castings.Bakalářská práce shrnuje předchozí poznatky o výrobě odlitků z litiny s kuličkovým grafitem. Dále se zabývá studiem vlivu technologických parametrů a chemického složení na mechanické vlastnosti zkušebních odlitků

Metallurgical influence of production of tin-walled from high silicon content spheroidal graphite cast iron for car industry

katedra: KSP; rozsah: 62sThe thesis summarizes previous knowledge about production of castings made of spherodial graphite cast iron. Furthermore this thesis is engaged in studying of influence of technological parameters and chemical composition on mechanical properties of specimen castings.Diplomová práce shrnuje předchozí poznatky o výrobě odlitků z litiny s kuličkovým grafitem. Dále se zabývá studiem vlivu technologických parametrů a chemického složení na mechanické vlastnosti zkušebních odlitků

Storage of extra virgin olive oil and its impact on fatty acid levels

Peroxide value, acid value, and fatty acid content were monitored during two-year storage in the following products: Luccese Olio extra vergine d'oliva (LOEVDO), Blanqueta extra-virgin olive oil (BEVOO) and Agrocreta extra-virgin olive oil (AEVOO). In LOEVDO and BEVOO, peroxide value increased by 50%; AEVOO showed 80% growth. Maximum acid value was found solely in LOEVDO (<0.8%). All the analyzed samples contained almost identical proportions of fatty acids. Minute amount of lauric acid (C 12:0) was indentified in BVEOO samples only. The two-year storage resulted in growth of oleic and stearic acid levels and in decrease of linoleic and palmitic acids concentration. The percentage of SAFA, MUFA and PUFA complied with recommended levels.operational Program Research and Development for Innovations (Vyzkum a vyvoj pro inovace); European Fund for Regional Development (ERDF); state budget of the Czech Republic within the Centre of Polymer Systems Project [CZ.1.05/2.1.00/03.0111]; 2112 Institutional Support for the Development of Research Organizations (Institucionalni podpora na rozvoj vyzkumne organizace) - Brno University of Technology; MSMT C

Tin compounds in food-their distribution and determination

The aim of this work was optimization of the methods of trace-and ultratrace analysis, such as ICP-OES, ETA-AAS for charting the resources of individual forms of tin in foodstuffs. Increase of the sensitivity of the method of ICP-OES was achieved using the techniques of generation of hydrides, which was also optimized. Based on the information available on the occurrence of the different forms of tin, it appears that many of these organometallic compounds are contained in marine animals; attention has mainly focused on organisms such as marine fish, crustaceans, molluscs and algae. Tin compounds of predominantly inorganic origin can be found in foods and beverages which are packed in cans with a protective tin coating, too. The above mentioned methods have been applied to the analysis of selected beverages with low content of tin such as Coca Cola, Sprite, Fanta, Gambrinus 10°, PowerKing, and milk in the cans. Furthermore samples of animal origin as Sardines in oil, and Hunter's salami were examined, too. Prior to the determination of tin, samples need to be appropriately modified or analysed. Decomposition of the samples was done in the microwave system. Low pressure ion exchange chromatography with on-line detection of ICP-OES was used for separation of inorganic tin compounds. Separation of organically bound tin compounds was performed by HPLC on a column of ACE C-18, 3 µm, 15 cm x 1.0 mm with off-line detection by ETA-AAS. All of the above forms of tin compounds can be separated with this column. Due to the improvement in the detection of organically bounded tin, HPLC with identical ACE C-18 column coupled online for example with ICP-MS or spectrofluorimetry could be recommended. © 2019 Muhammad Arba et al

Changes in phenolic content in ground red pepper (capsicum annuum l.) during storage

Dynamics of changes in phenolic content in ground red pepper spice (Capsicum annuum L.) was monitored during the period of 10/2016-01/2018. Phenolic compounds were determined: gallic acid, catechine, vanillic acid, caffeic acid, coumaric acid, ferulic acid, rutin, resveratrol, cinnamic acid. In order to carry out a relevant statistical evaluation, individual measurements were interpolated to obtain a weekly time series. The fastest weekly reduction in content occurs for cinnamic acid (0.9%), coumaric acid (0.6%), resveratrol (0.54%), catechine (0.53%), quercetin (0.47%), vanillic acid (0.47%), ferulic acid (0.39%), gallic acid (0.34%), and rutin (0.29%). For the total content of phenolic substances, weekly decrease of 0.4% was statistically significant (at significance level of 0.001). The losses of phenolic substances during storage are possible to be minimized partially by keeping in cold, dry, and dark storage areas, in airtight containers for wholesale and retail packages.European Fund for Regional Development ERDFEuropean Union (EU); state budget of the Czech Republic within the Centre of Polymer Systems Project [1.05/2.1.00/03.0111]; 2112-Institutional Support for the Development of Research Organization

Effects of the lactation period, breed and feed on amino acids profile of mare's milk

The effects of the lactation period, breed, and feed on amino acids profile of mare's milk were investigated. The feed contained two major essential amino acids (EAAs) leucine (7.31-10.3 g. kg-1) and arginine (6.37-9.59 g. kg-1); it also included minor EAAs methionine (2.11-3.05 g. kg-1) and histidine (2.48-3.60 g. kg-1). Glu+Gln, Asp+Asn, and proline, major nonessential amino acids (NEAAs), constituted approximately 60% of total NEAAs (TNEAAs). The ratio of total EAAs to NEAAs ranged from 1:1.2 to 1:1.4. Amino acids (AA) content throughout all milk samples varied due to mare's different conditions and lactation days. Except for the 1P milk sample, total AA content in the 2-8Ps specimens caused by differences in breed oscillated from the 2nd to 28th day of lactation within the following limits: 21.9-54.6 g. kg-1, 33.6-70.7 g. kg-1, 38.1-71.2 g. kg-1, 29.46-74.2 g. kg-1, 52.2-87.1 g. kg-1, 37.9-70.3 g. kg-1 and 26.4-64.5 g. kg-1, respectively. In relation to TEAAs in milk, the highest EAAs levels were reached in arginine, leucine and lysine ranging between 2.41-4.35 g. kg-1, 3.36-5.59 g. kg-1 and 2.72-4.80 g. kg-1, respectively, while the lowest AAs amounts were indicated in histidine and methionine, 0.91-1.58 g. kg-1 and 1.23-2.04 g. kg-1 respectively. Total NEAAs content was slightly higher than that of EAAs; the TNEAAs to TEAAs ratio was 1:0.9 proximately. Glu+Gln, Asp+Asn and proline were determined as major NEAAs of milk ranging between, 6.77-11.0 g. kg-1, 3.21-5.60 g. kg-1 and 1.25-2.18 g. kg-1, respectively; levels of NEAAs such as cysteine and glycine oscillated between 0.89-1.52 g. kg-1 and 0.64-1.15 g. kg-1, respectively. The average TAAs contents caused by breed differences were 62.8 g. kg-1, 42.8 g. kg-1, 44.7 g. kg-1 and 44.8 g. kg-1, respectively, on the 2nd, 5th, 10th, and 28th lactation days. © 2020 Potravinarstvo Slovak Journal of Food Sciences