Tolerance Limit-based Estimation of the Proportion of Non-conforming Parts in a Multiple Stream Process

The conventional way to characterize the proportion of non-conforming parts in a process is to calculate process capability indices and transform them into a ratio. These widely used indices are able to give digestible information about the ratio of non-conforming parts if some assumptions are fulfilled. A correct estimation method should be based on the output distribution of the process, and the uncertainty of the parameter estimates should be considered, as well. In this article, a special case of the output distribution is examined: a mixture of normal distributions is considered. In practice, this output distribution appears if a multiple stream process is investigated. The novelty of this study is to apply the tolerance interval-based estimation method for the proportion of non-conforming parts in a case study of a multiple stream process and to qualify the limitations of the proposed estimation method. A simulation study is performed to investigate the bias, mean square error, and root mean square error of the estimates from the two estimation methods (process performance index-based and tolerance interval-based) for different sample sizes for each stream (N ). It was found that, if it may be assumed that the speed of the streams is equal in the case of the sample sizes investigated (N = 25, 50, 100 per head), the proposed (tolerance interval-based) method overestimates the proportion of non-conforming parts while the conventional (process performance index-based) method underestimates it. The tolerance-limit based estimation method has asymptotically better properties than the process performance index-based estimation method

Isolation and structure of fullerene photodimer, C-120

Photopolymerization of C60 was performed on a gram scale via a new monomer transport method. After subsequent extractions of the raw polymer in organic solvents, lOOmg dimer and lOmg mixture of soluble oligomers were yielded. The structures of the soluble fractions and the insoluble polymer were studied by optical spectroscopy and x-ray diffraction methods. According to IR and UV-VIS spectroscopic data, the obtained photodimer is identical to the (2+2) cycloadduct C12o prepared previously. In contrast to previous crystallization studies, a fast precipitation of the dimer from toluene gives rise to the formation of a solvent-free microcrystalline solid. The crystal structure of the pure dimer is fee (a= 14.05 A) consisting of closely packed balls with the cycloadduct bonds oriented randomly along the 12 nearest neighbor directions. A linear relationship is found to exist between the fee lattice parameter (a) and the average number of bonded neighbours (nB) in various photopolymerized structures. For insoluble polymers nB«2 is estimated, supporting previous photopolymer models of small ring or branched clusters

Statistical Evaluation of 4-ethylphenol and 4-ethylguaiacol Concentrations to Support Sensory Evaluation of "Brett Character" of Wines: A Proposed Threshold

nalytical data of 260 sensory evaluated wine samples have been statistically examined. All samples had been classified by at least one taster of the five member jury as having "Brett character". Wines have been finally judged as "Good", having "Other defects" or "Brett character". 4-etylphenol (4-EP) and 4-ethylguaiacol (4-EG) concentrations showed different distributions for the "Brett character" group while the other two groups could not be distinguished from each-other. Threshold concentrations for 4-EP, 4-EG and their sum (4-EP + 4-EG) were calculated to classify wine samples as "non-Brett" and "Brett character". 4-EP concentrations were found to be the most reliable markers, with a 245 µg/l lower and 968 µg/l upper threshold. Below or above this range a sample can reliably be classified as "non-Brett" and "Brett character" respectively, while within this range only sensory evaluation can distinguish the two characteristics. Other tested classical analytical parameters did not show significant differences between these groups except for SO2 which was found to be lower in the "Brett character" group, stressing the importance of sulpihiting as a tool in the fight against Brettanomyces

Acute Ecotoxicological Effects of Bauxite Residue Addition on Mortality and Motion-frequency of Dendrobaena veneta and Enchytraeus albidus (Annelida) in Three Types of Soils

The bauxite residue is produced in high amount all over the world. This industrial waste is a possible soil-ameliorant material. Although the material has been producing in high amount, it is not frequent to reuse it. We investigated its ecotoxicological effects on two annelid species: Dendrobaena veneta and Enchytraeus albidus. Two forms of bauxite residue (BR: S – untreated; G – dried, filter pressed and gypsum neutralized) and three natural soils (NH: Nagyhörcsök, NY: Nyírlugos, OB: Őrbottyán) were examined. To determine the safe concentration in short term, the acute mortality and sublethal behavior tests (peristaltic motion-frequency) were performed. The bauxite residue addition (< 5/10 %) raised the pH and water holding capacity level of soils. Both types of the bauxite residue increased the motion-frequency of the worms. The untreated type had an acute mortality effect (> 25 %). Both species refused the higher concentration soils (≥ 10 %) of both types of bauxite residue. Slight bauxite residue addition may improve the life circumstances of annelids in acidic sandy soils because of the pH level and water holding capacity potential rise

Acute Ecotoxicological Effects of Bauxite Residue Addition on Mortality and Motion-frequency of Dendrobaena veneta and Enchytraeus albidus (Annelida) in Three Types of Soils

The bauxite residue is produced in high amounts all over the world. This industrial waste is a possible soil-amendment material. Although the material has been produced in high amounts, it is not frequently reused. We investigated its ecotoxicological effects on two annelid species: Dendrobaena veneta and Enchytraeus albidus. Two forms of bauxite residue (BR: S – untreated; G – dried, filter pressed, and gypsum neutralized) and three natural soils (NH: Nagyhörcsök, NY: Nyírlugos, OB: Őrbottyán) were examined. To determine the safe concentration of bauxite residue in soil on the short, acute mortality and sublethal behavioral tests (peristaltic motion-frequency) were performed. The bauxite residue addition (<5/10%) raised the pH and water holding capacity level of soils. Both types of the bauxite residue increased the motion-frequency of the worms. The untreated type had an acute mortality effect (>25%). Both species refused the soils containing both bauxite residue types at higher concentrations (>10%). Slight bauxite residue addition may improve the life circumstances of annelids in acidic sandy soils because of the potential rise of the pH level and water holding capacity

Kísérlet a lemorzsolódás mértékének és okainak megragadására a Debreceni Egyetem Gazdaságtudományi Kar példáján

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