过程的监视和测量

本文介绍了如何理解与实施ISO9001-2000标准中"过程的监视和测量".     

Fate of Staphylococcus aureus on vacuum-packaged ready-to-eat meat products stored at 21 degrees C

The U.S. Department of Agriculture has established standards for the composition and shelf stability of various ready-to-eat meat products. These standards may include product pH, moisture:protein ratio, and water activity (aw) values. It is unclear how closely these standards are based on the potential for pathogen growth or toxin production. Because the vacuum packaging used on most ready-to-eat meat products inhibits mold, Staphylococcus aureus is the pathogen most likely to grow on products with reduced aw and increased percentage of water-phase salt. In this study, 34 samples of various ready-to-eat meat products were inoculated with a three-strain mixture of S. aureus, vacuum packaged, and stored at 21 degrees C for 4 weeks. S. aureus numbers decreased by 1.1 to 5.6 log CFU on fermented products (pH < or = 5.1) with a wide range of salt concentrations and moisture content. Similarly, S. aureus numbers decreased by 3.2 to 4.5 log CFU on dried nonacidified jerky (aw < or = 0.82; moisture:protein ratio of < or =0.8). Products that were not fermented or dried clearly supported S. aureus growth and cannot be considered shelf stable. The product pH and moisture:protein ratio were the two compositional factors most highly correlated (R2 = 0.84) with S. aureus survival and growth for the types of products tested, but pH and aw or pH and percentage of water-phase salt also may provide useful predictive guidance (R2 = 0.81 and 0.77, respectively).     

Fluorescence imaging of the desorption of dye from fused silica versus silica gel

The desorption rate constants for a cationic dye from strong adsorption sites are compared for the same chromatographic interface but for two different substrates, fused silica and chromatographic silica gel. The dye is 1,1'-didodecyl-3,3,3'3'-tetramethylindocarbocyanine perchlorate (DiI). The interface consists of acetonitrile and a hydrocarbon monolayer (C8) covalently bound to the silica substrate. To measure slow desorption from fused silica, fluorescence imaging combined with correlation spectroscopy is used. To measure slow desorption from silica gel, fluorescence movies of silica gel particles are used. In both cases, the results show that there are two types of slow desorption processes on time scales exceeding 1 s. The desorption time from one type of site is within an experimental error of 7 s for both silica substrates. The adsorption kinetics for this type of site are slow, and the equilibrium population of DiI on these sites is comparable to that for DiI weakly adsorbed to the hydrocarbon monolayer. For the second type of site, for fused silica, the population of DiI is even higher than that of weakly adsorbed DiI, and the desorption time constant is approximately 2 min, although this is likely shortened by photobleaching. For silica gel, the relative population of DiI on this ultrastrong site is more than an order of magnitude lower, and the desorption time constant is 4.0 +/- 0.1 min. Both silica substrates thus show two types of sites whose time constants agree within experimental error, suggesting that the strong adsorption sites on fused silica are chemically the same as those on chromatographic silica gel.     

Real and artificial dream episodes: Comparison of report structure.

41 undergraduates reported 180 home dreams and produced, in the laboratory, 278 artificial dream reports. Artificial reports were based on each S's synthesis of randomly organized successions of photographic slides. To determine if the 2 report types were formally distinct, the reports were compared along 18 structural dimensions: self-involvement, continuity, temporal attributes, implausibility, 3 types of bizarreness, and 11 measures of syntactical complexity. Real dream reports differed from artificial reports on 2 of these measures. Real reports were characterized by greater self-involvement on the part of the dreamer, and when a real dream was judged to be implausible, its bizarreness was more likely to be due to a metamorphosis of one object or person into another. Despite these objective differences, 15 naive judges (graduate students and laboratory personnel) were unable to distinguish real from fake reports at a rate greater than chance. (9 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Do reverse stock splits indicate future poor stock performance?

There has been much written on the individual topics of bankruptcy prediction, corporate performance, and forward/reverse stock splits. However, there is little research into the relationship between reverse stock splits and subsequent corporate performance and the potential for bankruptcy. Previous research suggested there is a negative drift in stock prices following reverse splits. The purpose of this study is to provide and empirically support rationales for reverse splits by classifying reverse splitting firms into two groups. The presumed rationales for engaging in reverse splits would differ between the two groups, so do the subsequent stock performance. Our results show that both neural networks and Z-scores can successfully distinguish the two groups of firms while neural networks outperforms Z-scores in finding the firms with best performing stocks.     

H parameter identification for inflight detection of aircraft icing: the time-varying case

This paper considers inflight parameter identification of aircraft flight dynamics in the context of an ice management system. In particular, an H^∞ parameter identification algorithm is evaluated in terms of detecting an aircraft icing event using a noisy state measurement. Previous studies had addressed identification over several seconds during a maneuver, utilizing the excitation due to the maneuver and assuming a time-invariant parameter. This paper addresses identification over longer periods, where excitation is provided only by turbulence, and parameter variation must be considered. Simulation results demonstrate that for moderate turbulence, the time-varying H^∞ algorithm provides a timely and unambiguous icing indication.     

Winery wastewater management and treatment in the Niagara Region of Ontario,Canada: A review and analysis of current regional practices and treatment performance

The winemaking process produces a large volume of wastewater with highly variable characteristics. Methods in place to manage winery wastewater (WWW) vary, with some wineries treating their WWW on-site, while others direct the WWW to municipal wastewater treatment plants (WWTPs). Despite the significant presence and growth of the wine industry in the Niagara Region of Ontario, Canada, few data are available regarding the characteristics and treatment of WWW in this geographic region. This work presents a comprehensive review of full-scale treatment methods currently in place to manage and treat WWW at 53 wineries in the Niagara Region. The most common type of on-site treatment is the constructed wetland process, providing overall removal rates of >98% for chemical oxygen demand (COD) and >98% for total suspended solids (TSS) for the combined treatment of WWW and site-generated sanitary sewage. Subsurface effluent discharge is the most widely used disposal strategy, while larger systems treating WWW alone also reuse the effluent for vineyard irrigation. The construction and operation of on-site treatment systems at wineries does not address all WWW treatment needs, requiring a portion of the WWW to be co-treated at WWTPs. While full-scale operating data indicate that anaerobic co-digestion with municipal sludges is effective (89% COD removal), the co-digestion capacity is limited. Co-treatment in the municipal WWTPs' liquid treatment train leads to negative operational and performance impacts. No efficient WWW co-treatment options, viable in the long-term, are currently available at municipal WWTPs. Improved co-treatment strategies are required to address WWW treatment needs in the Niagara Region.     

Revealing a Transformation-Induced Plasticity (TRIP) Phenomenon in a Medium-Entropy Alloy

A transformation-induced plasticity phenomenon in Fe₆₅(CoCrMnNi)₃₅ medium-entropy alloy was investigated. According to the X-ray diffraction patterns, the as-cast specimen contains a single-phase face-centered cubic (fcc), while low-temperature annealing at 500 °C and 600 °C leads to the introduction of a body-centered cubic (bcc) phase as a secondary phase. Further increment of the annealing temperature to above 700 °C eliminates the bcc phase, and the microstructure was found to contain a single-phase fcc. At 20% true strain, an fcc-to-bcc phase transformation is observed; whereas, at 28% true strain, an fcc-to-hcp phase transformation takes place as an additional deformation mechanism. This strain-induced phase transformation phenomenon leads to improved tensile properties of this alloy.     

Molecular Background,Clinical Features and Management of Pediatric Mastocytosis: Status 2021

Pediatric mastocytosis is a heterogeneous disease characterized by accumulation of mast cells in the skin and less frequently in other organs. Somatic or germline mutations in the KIT proto-oncogene are detected in most patients. Cutaneous mastocytosis is the most common form of the disease in children. In the majority of cases, skin lesions regress spontaneously around puberty. However, in few patients, mastocytosis is not a self-limiting disease, but persists into adulthood and can show signs of systemic involvement, especially when skin lesions are small-sized and monomorphic. Children with mastocytosis often suffer from mast cell mediator-related symptoms. Severe hypersensitivity reactions can also occur, mostly in patients with extensive skin lesions and blistering. In a substantial number of these cases, the triggering factor of anaphylaxis remains unidentified. Management of pediatric mastocytosis is mainly based on strict avoidance of triggers, treatment with H1 and H2 histamine receptor blockers, and equipment of patients and their families with epinephrine auto-injectors for use in severe anaphylactic reactions. Advanced systemic mastocytosis occurs occasionally. All children with mastocytosis require follow-up examinations. A bone marrow investigation is performed when advanced systemic mastocytosis is suspected and has an impact on therapy or when cutaneous disease persists into adulthood.