Статистические методы и анализ проблем управления качеством

В работе И.В. Плотниковой и Л.А. Редько проведен анализ проблем управления качеством на приборостроительном предприятии с использованием статистических методов. Определены основные значимые факторы появления несоответствий

Comparison of Helicobacter pylori in oral cavity and gastric mucosa according to virulence genotype (cagA and vacA m1)

Indexación: Web of Science; ScieloObjetivo: Comparar el genotipo de virulencia (genes cagA y vacA m1) de Helicobacter pylori, obtenido simultáneamente de mucosa gástrica y cavidad oral. Material y Métodos: Para esto se incluyeron muestras de biopsias gástricas de 18 pacientes. Las muestras orales de estos pacientes fueron obtenidas de placa bacteriana y saliva del piso de boca y base de la lengua. Las muestras fueron estudiadas con RPC convencional y RPC en tiempo real (RPC-TR). Los genes de virulencia cagA y vacA m1 fueron estudiados con RPC-TR. Resultados: De acuerdo a la presencia o ausencia de los genes de virulencia cagA y vacA m1 detectados en las muestras gástricas y orales, se pudieron diferenciar siete combinaciones diferentes. Conclusión: Estos resultados sugieren que existe una variedad de genotipos de virulencia en Helicobacter pylori en el estómago y la cavidad oral, predominando en los pacientes incluidos en este estudio las cepas con genotipos asociados a menor virulencia (cagA-, vacA m1-).Objective: To compare the virulence genotype (cagA and vacA ml genes) of Helicobacter pylori obtained simultaneously from gastric mucosa and oral cavity. Material and Methods: Gastric samples of 18 patients were obtained by endoscopic biopsies. Oral samples of these patients were obtained from dental plaque and saliva swabs from the floor of the mouth and the base of the tongue. All samples were studied by conventional PCR and real-time PCR (RT-PCR). Virulence genes cagA and vacA ml were studied by RT- PCR. Results: According to presence and/or absence of cagA and vacAm1 genes, seven different combinations were observed. Conclusion: These results suggest that there is a variety of genetic profiles of Helicobacter pylori in the stomach and oral cavity, with a predominance of less virulent genotypes in the patients included in this study (cagA-, vacA m1-).http://ref.scielo.org/vhtj7

The effects of orthotics on lower extremity variability during running

Introduction: Abnormal foot mechanics may affect kinematics of the lower extremity, predisposing individuals to injury. Foot orthotics are often used to alter lower extremity mechanics. Little research is available examining effects of orthotics on lower extremity kinematic variability during running. Methods: 30 recreational runners (15 males, 15 females) identified as excessive pronators participated in this study. Subjects were tested with and without orthotics while running on a treadmill at 3.35 m/s. Ankle and knee joint kinematics were calculated using cardan angles. Kinematic variability of the ankle and knee joints was evaluated using traditional methods (standard deviation and coefficient of variation) and a non-traditional method (spanning sets). Results: There was a significant difference in transverse plane knee kinematics as an interaction effect of gender and condition (F = 4.544, P =.043). There were no significant differences upon other kinematic parameters of the ankle or knee data as an interaction effect between gender and condition. There was a significant difference in transverse plane knee kinematic variability measured via spanning set as an interaction effect of gender and condition (F = 5.306, P = .029). There were no other significant differences in kinematic variability measures of the ankle or knee data as an interaction effect between gender and condition. Conclusion: It is not clear if one could clearly suggest or refute the use of an OTC orthotic for direct control of ankle and knee mechanics. For some the less expensive OTC device may provide an inexpensive alternative to a higher priced custom device. For others there may be a definite need for a more custom fit appliance. There is no reason to suspect the changes in kinematics and variability reported in this study are the effect of a pathologic (abnormal) control strategy. It is not completely clear as to whether or not the SS method used is more sensitive to movement variability

Selection of Saccharomyces cerevisiae strains for efficient very high gravity bio-ethanol fermentation processes

An optimized very high gravity (VHG) glucose medium supplemented with low cost nutrient sources was used to evaluate bio-ethanol production by 11 Saccharomyces cerevisiae strains. The industrial strains PE-2 and CA1185 exhibited the best overall fermentation performance, producing an ethanol titre of 19.2% (v/v) corresponding to a batch productivity of 2.5 g l-1 h-1, while the best laboratory strain (CEN.PK 113-7D) produced 17.5% (v/v) ethanol with a productivity of 1.7 g l-1 h-1. The results presented here emphasize the biodiversity found within S. cerevisiae species and that naturally adapted strains, such as PE-2 and CA1185, are likely to play a key role in facilitating the transition from laboratory technological breakthroughs to industrialscale bio-ethanol fermentations.Fundação para a Ciência e a Tecnologia (FCT) - PTDC/BIO/66151/2006, SFRH/ BD/64776/2009, SFRH/BPD/44328/ 200

Impacts of biofilms on the conversion of cellulose

Lignocellulose is a widely available renewable carbon source and a promising feedstock for the production of various chemicals in biorefineries. However, its recalcitrant nature is a major hurdle that must be overcome to enable economic conversion processes. Deconstruction of lignocellulose is part of the global carbon cycle, and efficient microbial degradation systems have evolved that might serve as models to improve commercial conversion processes. Biofilms—matrix encased, spatially organized clusters of microbial cells and the predominating lifestyle in nature—have been recognized for their essential role in the degradation of cellulose in nature, e.g., in soils or in the digestive tracts of ruminant animals. Cellulolytic biofilms allow for a high concentration of enzymes at the boundary layer between the solid substrate and the liquid phase and the more complete capture of hydrolysis products directly at the hydrolysis site, which is energetically favorable. Furthermore, enhanced expression of genes for carbohydrate active enzymes as a response to the attachment on solid substrate has been demonstrated for cellulolytic aerobic fungi and anerobic bacteria. In natural multispecies biofilms, the vicinity of different microbial species allows the creation of efficient food webs and synergistic interactions thereby, e.g., avoiding the accumulation of inhibiting metabolites. In this review, these topics are discussed and attempts to realize the benefits of biofilms in targeted applications such as the consolidated bioprocessing of lignocellulose are highlighted

Towards Net Zero Greenhouse Gas Emissions in the Energy and Chemical Sectors in Switzerland and Beyond - A Review

In today's societies, climate-damaging and finite fossil resources such as oil and natural gas serve a dual purpose as energy source and as carbon source for chemicals and plastics. To respond to the finite availability and to meet international climate goals, a change to a renewable energy and raw material basis is inevitable and represents a highly complex task. In this review, we assess possible technology paths for Switzerland to reach these goals. First, we provide an overview of Switzerland's current energy demand and discuss possible renewable technologies as well as proposed scenarios to defossilize the current energy system. In here, electric vehicles and heat pumps are key technologies, whereas mainly photovoltaics replace nuclear power to deliver clean electricity. The production of chemicals also consumes fossil resources and for Switzerland, the oil demand for imported domestically used chemicals and plastics corresponds to around 20% of the current energetic oil demand. Thus, we additionally summarize technologies and visions for a sustainable chemical sector based on the renewable carbon sources biomass, CO2 and recycled plastic. As biomass is the most versatile renewable energy and carbon source, although with a limited availability, aspects and proposed strategies for an optimal use are discussed

Biochemical Conversion Processes of Lignocellulosic Biomass to Fuels and Chemicals – A Review

Lignocellulosic biomass – such as wood, agricultural residues or dedicated energy crops – is a promising renewable feedstock for production of fuels and chemicals that is available at large scale at low cost without direct competition for food usage. Its biochemical conversion in a sugar platform biorefinery includes three main unit operations that are illustrated in this review: the physico-chemical pretreatment of the biomass, the enzymatic hydrolysis of the carbohydrates to a fermentable sugar stream by cellulases and finally the fermentation of the sugars by suitable microorganisms to the target molecules. Special emphasis in this review is put on the technology, commercial status and future prospects of the production of second-generation fuel ethanol, as this process has received most research and development efforts so far. Despite significant advances, high enzyme costs are still a hurdle for large scale competitive lignocellulosic ethanol production. This could be overcome by a strategy termed 'consolidated bioprocessing' (CBP), where enzyme production, enzymatic hydrolysis and fermentation is integrated in one step – either by utilizing one genetically engineered superior microorganism or by creating an artificial co-culture. Insight is provided on both CBP strategies for the production of ethanol as well as of advanced fuels and commodity chemicals

Entwicklung einer Methode zur Temperaturbestimmung von Fluiden mithilfe von Berührungsthermometern bei niedrigen Eintauchtiefen

Die exakte Bestimmung der Temperatur gewinnt u. a. in der Wärmeverbrauchsmessung eine immer höhere Bedeutung. Messabweichungen haben hier eine direkte Auswirkung auf die Kostenabrechnung. Die vorliegende Arbeit untersucht in diesem Zusammenhang die Messabweichung durch Wärmeableitung und das Ansprechverhalten von Widerstandsthermometern bei geringen Eintauchtiefen in ein zu messendes Medium. Zudem wurde eine Prüfeinrichtung zur Untersuchung von Widerstandsthermometern unter Einbaubedingungen entwickelt und validiert. Diese erlaubt die Untersuchung des statischen und dynamischen Verhaltens von Thermometern, sowie den direkten Vergleich unterschiedlicher Einbaustellen. Eine weitere dargestellte Neuentwicklung ist ein für niedrige Eintauchtiefen optimiertes Widerstandsthermometer. Dieses realisiert eine gute Ankopplung des Temperatursensors an das zu messende Medium, sowie eine Entkopplung von der anders temperierten Umgebung.The exact determination of temperature becomes more and more important - particularly in the field of heat consumption measurement. Here, the temperature difference at the forward and return line in combination with the flow rate is used to determine the heat extracted. Measurement uncertainty have a direct effect on the cost accounting. Due to design of commonly used heat meters, there is only little space at the installation point of the thermometer at the return line. At this point the thermometer is often immersed tangentially, which causes a non-negligible measurement deviation. This thesis analyses in detail the measurement deviation caused by heat conduction and the response behavior of resistance thermometers at low immersion depth into a medium. The significance of a thermal connection of the sensor to the medium and the decoupling from the differently tempered environment becomes clear. The used medium is also important; for example: water-glycol mixtures are often used in heat-/cooling transfer applications. Their use has a high influence on the thermal measurement deviation and the response behavior of a resistance thermometer, especially at low flow rates. In addition, the possibility of using the Loop Current Step Response Test in the heat consumption measurement was validated. This test allows to measure the response times of resistance thermometers under installation conditions. Target of this thesis is the utilization of the obtained knowledge. A testing device for the examination of resistance thermometers under installation conditions was developed and validated. This device is designed as a flow channel and enables the examination of the static and dynamic behavior of thermometers, as well as the direct comparison of different installation points. The measuring sections can be easily exchanged via flange system. The implementation and evaluation of the different measuring programs runs automatically - due to a software which was especially developed for this application. A resistance thermometer - optimized for low immersion depths and combining heat conducting and insulating plastics - is another new development. Thus a good coupling of the temperature sensor to the medium as well as a decoupling from the different tempered environment was implemented.Die exakte Bestimmung der Temperatur gewinnt u. a. in der Wärmeverbrauchsmessung eine immer höhere Bedeutung. Hier wird mithilfe der Temperaturdifferenz an einem Vor- und Rücklauf in Kombination mit der Durchflussmenge die entnommene Wärme bestimmt. Messabweichungen haben hier eine direkte Auswirkung auf die Kostenabrechnung. Konstruktionsbedingt ist bei den gängigen Wärmemengenzählern an der Thermometer-Einbaustelle des Rücklaufs nur wenig Platz. Hier wird häufig tangential in das Medium eingetaucht, was eine nicht vernachlässigbare Messabweichung verursacht. In der Arbeit wird die Messabweichung durch Wärmeableitung und das Ansprechverhalten von Widerstandsthermometern bei geringen Eintauchtiefen in ein zu messendes Medium näher untersucht. Dabei wird die Bedeutung einer thermischen Ankopplung des Sensors an das Medium, sowie die Entkopplung von der anders temperierten Umgebung deutlich. Einen Einfluss hat auch das verwendete Medium. In der Wärme-/Kälteübertragung werden häufig Wasser-Glykol-Gemische verwendet. Deren Verwendung hat gerade bei niedrigen Strömungsgeschwindigkeiten einen hohen Einfluss auf die thermische Messabweichung und das Ansprechverhalten eines Widerstandsthermometers. Zudem wurde auch die Möglichkeit zur Nutzung des Loop Current Step Response Tests in der Wärmeverbrauchsmessung validiert. Dies erlaubt das Messen von Ansprechzeiten unter Einbaubedingungen. Ziel der Arbeit ist die Nutzbarmachung erzielter Erkenntnisse. So wurde eine Prüfeinrichtung zur Untersuchung von Widerstandsthermometern unter Einbaubedingungen entwickelt und validiert. Diese, als Strömungskanal konzipierte Prüfeinrichtung, erlaubt die Untersuchung des statischen und dynamischen Verhaltens von Thermometern, sowie den direkten Vergleich unterschiedlicher Einbaustellen. Die Messstrecken sind über ein Kleinflansch-Verbindungssystem austauschbar. Die Durchführung und Auswertung der unterschiedlichen Messprogramme läuft automatisch über eine eigens entwickelte Software ab. Eine weitere Neuentwicklung ist ein für niedrige Eintauchtiefen optimiertes Widerstandsthermometer. Hier wurden wärmeleitfähige und thermisch isolierende Kunststoffe kombiniert. So wurde eine gute Ankopplung des Temperatursensors an das zu messende Medium, sowie eine Entkopplung von der anders temperierten Umgebung realisiert

Mapping the thermal conductivity of SiC/SiC composites

This thesis investigates the uses of time-domain thermoreflectance (TDTR) to map the thermal conductivity of SiC/SiC composites that are being considered for use as replacement materials in current light-water reactors (LWR), and also as materials for use in next generation nuclear reactors. The thermonuclear properties of the SiC/SiC composites can be tuned to particular situations by varying how the composite is formed. To this end, computational methods are used to predict the properties of these composites. However, currently these methods only take into account the thermal properties of the constituent components of the composite prior to being integrated, potentially missing information on how the thermal properties of the components change post-composite-integration. Additionally, they do not take into account the interfacial thermal conductance between the fiber, interphase, and matrix, and the interphase is typically calculated based on the through-plane thermal conductivity of the matrix, if it is calculated at all. This thesis uses TDTR to map Hi-Nicalon Type S fiber, CVI matrix SiC/SiC composites, enabling the measurement additional thermal information than can be obtained by measuring the matrix or fibers of a composite individually. The thermal conductivity of the interphase is also measured. Crystalline 6H and 4H SiC wafers have their thermal conductivity measured using TDTR, and their phases are confirmed through Raman spectroscopy. The effects of irradiation on SiC is investigated by using TDTR mapping to measure the thermal conductivity of a 6H SiC wafer that has been implanted with He ions. Additional uses of TDTR mapping are explored by measuring the thermal conductivity of hybrid superlattice structures, and beam offset measurements are used to measure the in-plane thermal conductivity of a MEMS infrared detector device