Fluid Film Bearing Fundamentals And Failure Analysis.

Tutorialpg. 161-186Fluid film bearing technology is presented in this tutorial as it applies to turbomachinery equipment. The focus here is on the practical aspects of fluid film journal bearings, as opposed to theoretical analysis. Failure modes and the mechanisms leading to these failures will be discussed, along with techniques used to identify and cure them. The influence of different bearing configurations on the dynamics of rotor bearing systems will also be discussed

High Speed Journal And Thrust Bearing Design

PaperPg. 56-61.There are many approaches to the design of thrust and journal hearings for high speed turbomachinery, ranging from the simplest flat thrust bearings and plain journal hearings to the very sophisticated multiwedge designs for both thrust and journal bearings. It is the intent of this paper to stress some fundamentals by which bearing designs can be selected which match the performance requirements of various types of turbomachines. The scope of this paper will be limited to design of fluid film bearings and will therefore not include any discussion on the use of rolling element bearings nor solid film lubricated bearings. Fluid film bearings should be designed to meet the operating requirements of the machine if at all possible. In some cases, an economic decision dictates varying or compromising the design of the particular machine to accept a less expensive and less sophisticated bearing design. An argument on the original reasoning versus the long term effect of such decisions is beyond the scope of this discussion

High Efficiency Fluid Film Thrust Bearings For Turbomachinery

LecturePg. 33-38.Fluid film thrust bearings in use on high speed high capacity turbomachinery absorb a great amount of energy in performing their task of positioning rotors. A review of thrust bearing fundamentals along with the latest design concepts briefly outline how thrust bearing performance can be substantially improved. The major improvements come from selection of materials and methods of lubrication

Factores determinantes del precio de la naranja chilena de exportacion

38 p.El objetivo general de este trabajo es: estimar una función de precios hedónicos para las características más sobresalientes o relevantes de la naranja chilena de exportación. Los objetivos específicos son, estimar el impacto porcentual en el precio de exportación, de: a) variedades Lane Nate (Lan), Navel (Nav) y Washington (Wa) b) años de exportación año 2008 (año 08) y año 2009 (año 09) c) meses de comercialización octubre (oct) d) calibre de las naranjas (cal) y e) lugar de destino de las naranjas Algeciras (Al), Barcelona (Ba), Houston (Hou), Montreal (Mon), Rótterdam (Rott), Tokio (To) f) número de cajas (nCaj) g) categorías Fancy (F) y extra Fancy (eF). Para el logro de estos objetivos se revisaron los boletines de exportación de las temporadas 2007, 2008, y 2009 de la empresa exportadora Santa Cruz S.A. Se obtuvieron 347 datos, los que fueron tabulados en una planilla Excel, empleando una forma funcional semilogarítmica se estimó la siguiente función de precios hedónicos, donde ln P es el logaritmo natural del precio (US $/kg). naranja chilena exportada. Con la excepción de los coeficientes variedad Lane nate, navel, categoría Fancy y año 2008. Todos los coeficientes de regresión son estadísticamente distintos de cero con un 90 por ciento de confianza o más. Las principales conclusiones del estudio fueron, a) Existe una función hedónica entre precio y las variables calibre, categoría, destino, número de cajas, mes y año de comercialización, la que permitió estimar el precio marginal de las naranjas exportadas. b) Las variables más influyentes en el precio de la naranja es la variable año de comercialización siendo el año 2009 el más importante agregando al precio de referencia US$2,215 /caja de naranja. c) Los Ln P = 2,24219 + 0,0002*nCaj - 0,00557*cal + 0,08178*Al + 0,08219*Ba + 0,20703*Hou - 0,08715*Mon + 0,06998*Rott + 0,12119*To + 0,065*Lan + 0,00368*Nav - 0,06454*oct + 0,01045*F + 0,10534*eF + 0,06526*año 08 + 0,25011*año 09. puertos de destino también influyen en el precio de la naranja. Puede agregar o restar valor. Puertos como Houston tiene un efecto positivo frente al precio de referencia, en cambio el puerto de Montreal, castiga el precio de la naranja. d) La categoría de la naranja tiene un impacto porcentual notablemente alto. Al ser de categoría Extra Fancy, se suma valor al precio de referencia a las naranjas de categoría superior. e) El número de cajas corresponde a una variable de impacto porcentual levemente positivo, añadiendo US$0,002 por caja extra en cada embarque./ ABSTRACT: The general objective of this research is to estimate a hedonic function for prices of chilean oranges in the foreign markets. The specific goals are, to estimate the percentage impact in the price of export, of: a) orange varieties: Lane Nate (Lan), Navel (Nav) and Washington (Wa) b) exportation years year 2008 (year 08) and year 2009 (year 09) c)month of marketing october (oct) d) orange sizes (cal) and e) place of destination Algeciras (Al), Barcelona (Ba), Houston (Hou), Montreal (Mon), Rotterdam (Rott), Tokyo (To) f) number of boxes (nCaj) g) categories: Fancy (F) and extra Fancy (eF). In order to reach these goals the export forms for the seasons 2007, 2008, 2009 of the exporting enterprise Santa Cruz S.A. Were gathered, yielding, a total of 347 pieces of information. Using a semilogarithmic functional form the following hedonic function was estimated: From this research, the following conclusions were obtained, a)There is a hedonic function between price and variables of size, destination markets, number of boxes, marketing month which allowed the estimation of the marginal price. b) The most influential variable is the year of marketing showing 2009 as the most important year adding US$2,215 to the referential price per box of oranges. c) Orange category has a big impact on referential price. Extra Fancy category adds value to better quality oranges. d) There are also ports of destination with influence on the price in a positive way as Houston or in a negative impact as Montreal. e) Another positive variable that shows a minimal impact is the number of boxes adding US$0,002 per extra box on each delivery Ln P = 2,24219 + 0,0002*nCaj - 0,00557*cal + 0,08178*Al + 0,08219*Ba + 0,20703*Hou - 0,08715*Mon + 0,06998*Rott + 0,12119*To + 0,065*Lan + 0,00368*Nav - 0,06454*oct + 0,01045*F + 0,10534*eF + 0,06526*año 08 + 0,25011*año 09

Retrofit Installation Of A Boiler Feed Pump Hydraulic Coupling.

LecturePg. 101-110The application of main turbine-generator shaft drive for boiler feed pumps is generally accepted as a method to increase unit efficiency. The use of shaft drive eliminates the power requirement of an auxiliary motor or turbine drives. The addition of variable speed to this shaft drive provides economic advantages at lower unit loads. During the installation of any equipment, it is necessary to pay particular attention to all facets of the design. It is especially important when dealing with an operating facility for which many design details are not readily available. A case history of a utility's experience in installing variable speed hydraulic couplings for main boiler feed pump drive service is presented

Concentrations of organic contaminants in industrial and municipal bioresources recycled in agriculture in the UK

Many types of bioresource materials are recycled in agriculture for soil improvement and as bedding materials for livestock and have potential for transfer into plant and animal foods. Representative types of industrial and municipal bioresources were selected to assess the extent of organic chemical contamination, including: (i) land applied materials: treated sewage sludge biosolids), meat and bone meal ash (MBMA), poultry litter ash (PLA), paper sludge ash (PSA) and compost-like-output (CLO), and (ii) bedding materials: recycled waste wood (RWW), dried paper sludge (DPS), paper sludge ash (PSA) and shredded cardboard. The materials generally contained lower concentrations of polychlorinated dibenzo-pdioxins/dibenzofurans (PCDD/Fs) and dioxin-like polychlorinated biphenyls (PCBs) relative to earlier reports, indicating the decline in environmental emissions of these established contaminants. However, concentrations of polycyclic aromatic hydrocarbons (PAHs) remain elevated in biosolids samples from urban catchments. Polybrominated dibenzo-p-dioxins/dibenzofurans (PBDD/Fs) were present in larger amounts in biosolids and CLO compared to their chlorinated counterparts and hence are of potentially greater significance in contemporary materials. The presence of non-ortho-polychlorinated biphenyls (PCBs) in DPS was probably due to non-legacy sources of PCBs in paper production. Emerging flame retardant compounds, including: decabromodiphenylethane (DBDPE)and organophosphate flame retardants (OPFRs), were detected in several of the materials. The profile of perfluoroalkyl substances (PFAS) depended on the type of waste category; perfluoroundecanoic acid (PFUnDA) was the most significant PFAS for DPS, whereas perfluorooctane sulfonate (PFOS) was dominant in biosolids and CLO. The concentrations of polychlorinated alkanes (PCAs) and di-2-ethylhexyl phthalate (DEHP) were generally much larger than the other contaminants measured, indicating that there are major anthropogenic sources of these potentially hazardous chemicals entering the environment. The study results suggest that continued vigilance is required to control emissions and sources of these contaminants to support the beneficial use of secondary bioresource materials

Optimisation de la production de cartilage in vitro pour des études pharmacologiques de molécules anti-arthrosiques

Dans ce travail, nous avons déterminé le meilleur protocole pour la préparation d'un tissu en ingénierie du cartilage afin d'étudier les effets potentiels anti-arthritiques et/ou anti-arthrosiques de molécules comme les insaponifiables d'avocat/soja (ASU). Pour cette étude nous avons utilisé des chondrocytes articulaires de veaux et une lignée de chondrocytes murins (MC615), respectivement ensemencés dans des éponges de collagène ou en culture en monocouche. Les cultures ont reçu ASU (1, 3 ou 10 g/ml) tous les jours et/ou IL-1 (0,1 ; 0,25 ; 0,5 ; 1 ; 5 ou 20 ng/ml) pour 1 ou 3 jours. Pour les chondrocytes de veaux, nous avons sélectionné une culture de 15 jours en éponge de collagène ensemencée par 107 de cellules. Ce modèle montrait une prolifération cellulaire minimale, un dépôt de GAGs maximal et une haute expression de COL2A1, d'agrécanne et de COMP. En présence d'IL-1 , nous avons observé une diminution de COL2A1, de l'agrécanne et de COL1A1 et une augmentation d'IL-1Ra, de TIMP-1, de MMP-1 (450 fois), MMP-3 (54 fois), MMP-13 (60 fois), ADAMTS-4 (54 fois) et ADAMTS-5 (10 fois). Au niveau protéique, une augmentation dose dépendante de la MMP-1 et de la MMP-13 a été détectée avec moins de 15% sous leurs formes actives. Le traitement par ASU n'a pas modifié l'expression des MMPs mais a permis d'inhiber l'activité de la protéine MMP-13 (zymographie 2D+DTT) par les chondrocytes de veaux activés via IL-1 . Pour les cultures de MC615, nous avons observé un niveau d'expression de MMP-13 similaire et une légère augmentation de son activité avec IL-1 par rapport au contrôle. Le traitement par ASU, en présence d'IL-1 , n'a pas modifié l'expression et l'activité de la MMP-13LYON1-BU.Sciences (692662101) / SudocSudocFranceF

New Methods for the Synthesis of alpha-Amino Acid Derivatives From N-tert-Butanesulfinyl Imines AND The Synthesis and Application of Novel Amino Acid Based N-tert-Butanesulfinyl Amide Organocatalysts

AbstractNew Methods for the Synthesis of alpha-Amino Acid Derivatives From N-tert-Butanesulfinyl IminesANDThe Synthesis and Application of Novel Amino Acid Based N-tert-Butanesulfinyl Amide OrganocatalystsbyMelissa Ann HerbageDoctor of Philosophy in ChemistryUniversity of California, BerkeleyProfessor Jonathan A. Ellman, ChairChapter 1. Methods for the synthesis of alpha-amino acid derivatives prepared from N-tert-butanesulfinyl imines are reviewed.Chapter 2. The rhodium-catalyzed addition of arylboronic acids to N-tert-butanesulfinyl imino esters is described. This chemistry is compatible with a variety of electronically and sterically diverse arylboronic acids providing the N-tert-butanesulfinyl protected alpha-arylglycine products in good yields and high diastereoselectivities. In addition, the utility of this method is demonstrated by subjecting the enantiomerically enriched N-tert-butanesulfinyl protected products to selective synthetic manipulations with little to no racemization. The synthesis of an N-tert-butanesulfinyl isatin imine and its use in the rhodium-catalyzed addition of arylboronic acids reaction is also described. Chapter 3. The copper-catalyzed addition of bis(pinacolato)diboron to N-tert-butanesulfinyl imines is described. This chemistry is amenable to a variety of alkyl and aryl N-tert-butanesulfinyl imines and provides rapid access to use of a number of chiral alpha-amino boronate esters, a biologically relevant scaffold that is difficult to access by other means. The utility of this methodology was demonstrated by the efficient synthesis of bortezomib (Velcade®), the first FDA approved proteasome inhibitor drug. The further functionalization of the alpha-amino boronate products is also described. This includes the homologation of the alpha-amino boronate ester products as well as the conversion of the boronate ester to the potassium trifluoroborate salt. The application of this methodology for the enantioselective synthesis of alpha-amino boronate esters is also addressed. Chapter 4. The synthesis of new N-tert-butanesulfinyl amide organocatalysts and their application to the intermolecular aldol reaction is described. A number of catalysts were prepared in one step from commercially available amino acid precursors and were tested for their activity in the intermolecular aldol reaction. However, preliminary results indicate that the primary amine catalysts are not competitive with other amino acid derived catalysts reported in the literature. Further optimization is necessary to fully evaluate the potential for this new class of catalysts