Automatic cutting of foil on flat glass matting line

katedra: KSR; přílohy: 17 výkresů; rozsah: 53 s.This Thesis is focused on the creation of variants of automatization cutting leftovers of foil in the produciton of oneside acid-etched glass Matelux at AGC Barevka. In theoretical part is explained production technology and described the problem arisen in production. The practical part is focused on creating usable variants, which is one detailed construction developed based on the decision analysis. The result of this work is concept of automated cutting leftovers of foil.Tato práce je zaměřena na vytvoření variant automatizace ořezávání přebytků fólie při výrobě jednostranně matovaného skla Matelux v závodě AGC Flat Glass Czech a.s., člen AGC Group ? Závod Barevka v Dubí u Teplic V teoretické části je vysvětlena technologie výroby a popsán problém vzniklý při výrobě. Praktická část je zaměřena na vytvoření použitelných variant, z nichž je jedna na základě rozhodovací analýzy podrobně konstrukčně zpracována. Výsledkem práce je návrh automatizovaného ořezávání přebytků fólie

Effect of Bioaccumulation of Heavy Metals in Oreochromis niloticus Tissues of an Urban Lake in Southern Brazil

In this study, the effect of the bioaccumulation of metals on Oreochromis niloticus tissues was evaluated. Significant Co, Mn and Ni concentrations were found in the lake water near the fertilizer industries. In the sediment was identified the presence of Cd (4.612 ± 0.930 mg kg-1), Ni (46.847 ± 3.801 mg kg-1) and Zn (865.534± 89.437) mg kg-1) in concentrations above the probable effect level (PEL). For Cu (141.963 ± 5.148 mg kg-1) and Pb (53.362 ± 6.621 mg kg-1) concentrations between the threshold effect (TEL) or probable effect (PEL) levels. Regarding Oreochromis niloticus tissues, the concentration of metals in the liver was higher than found in muscle. The biomarkers indicated that the hepatic cells of Oreochromis niloticus are under oxidative stress, explained by the higher levels of reduced glutathione (GSH), lipid peroxidation (LPO) and protein carbonylation (PCO) when compared to control fish tissues. The set of biomarkers presented in this study contribute to define the effects of the bioaccumulation of metals in Oreochromis niloticus tissues. DOI: http://dx.doi.org/10.17807/orbital.v11i7.136

Determination of Nicotine in Cigarette Tobacco Smuggled to Brazil by Modified QuEChERS Methodology

The study of cigarette authenticity in Brazil is important due to increasing consumption of contraband cigarettes. Nicotine concentration is an important parameter reflecting the quality of tobacco used in the production of these cigarettes. Simple methods for this determination, which produce reduced waste, are environmentally and industrially important. The nicotine concentration of smuggled cigarette tobacco was determined by the QuEChERS method, requiring some modifications, such as decreasing the volume of the extractor solvent, changes in pH, and removal of the sample hydration step. Quantification was performed by gas chromatography using a flame ionization detector. The Doehlert matrix design was used to optimize the method. The extraction recoveries ranged from 97.5% to 99.6%, with relative standard deviation (RSD) ≤ 2.5% and limits of detection and quantification of 0.6 mg L-1 and 2.5 mg L-1, respectively. The method was sensitive and accurate for the detection and quantification of nicotine. The nicotine concentration in contraband cigarettes was found to be lower than that observed in legal cigarettes. The method was successfully applied to real samples of smuggled and legal cigarettes, providing a robust method for routine analysis and proving the need for more studies on quality control of smuggled cigarettes in Brazil

Concepções de estudantes acerca de Ciência e Tecnologia reforçam a necessidade da ACT

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Proposta de uso de atividade investigativa para o aprendizado de reações endotérmicas e exotérmicas

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Effect of Bioaccumulation of Heavy Metals in Oreochromis niloticus Tissues of an Urban Lake in Southern Brazil

In this study, the effect of the bioaccumulation of metals on Oreochromis niloticus tissues was evaluated. Significant Co, Mn and Ni concentrations were found in the lake water near the fertilizer industries. In the sediment was identified the presence of Cd (4.612 ± 0.930 mg kg-1), Ni (46.847 ± 3.801 mg kg-1) and Zn (865.534± 89.437) mg kg-1) in concentrations above the probable effect level (PEL). For Cu (141.963 ± 5.148 mg kg-1) and Pb (53.362 ± 6.621 mg kg-1) concentrations between the threshold effect (TEL) or probable effect (PEL) levels. Regarding Oreochromis niloticus tissues, the concentration of metals in the liver was higher than found in muscle. The biomarkers indicated that the hepatic cells of Oreochromis niloticus are under oxidative stress, explained by the higher levels of reduced glutathione (GSH), lipid peroxidation (LPO) and protein carbonylation (PCO) when compared to control fish tissues. The set of biomarkers presented in this study contribute to define the effects of the bioaccumulation of metals in Oreochromis niloticus tissues. DOI: http://dx.doi.org/10.17807/orbital.v11i7.136