bluuebunny/crossref_metadata_2025_split huggingface dataset:
Evaluation of decellularized esophagus as a scaffold for cultured esophageal epithelial cells
Authors: Ozeki Masayasu , Narita Yuji , Kagami Hideaki , Ohmiya Naoki , Itoh Akihiro , Hirooka Yoshiki , Niwa Yasumasa , Ueda Minoru , Goto Hidemi 
Published: July 2006

AbstractRecently, decellularized tissue has been reported to have the potential to regenerate a variety of tissues. However, the optimal protocol for a decellularized esophagus has not been studied. Here, we investigated the effect of different decellularization protocols on the histology andbiocompatibility of decellularized esophagi in view of future applications to tissue engineering. The esophageal mucosal epithelium (EP) from 4‐week‐old Wistar rats was enzymatically dissociated and cultured with growth‐arrested feeder cells. Two methods for decellularization usingdeoxycholic acid (DEOX) or Triton X‐100 (TRITON) were compared on esophagi from adult Wistar rats. Those treated with DEOX showed superior mechanical properties, maintenance of extracellular matrix, and lower DNA content than those treated with TRITON. To evaluate the biocompatibility of the scaffold, cultured (passage 3) esophageal epithelial cells were seeded inside the decellularized esophagus and cultured for 7 days. The cells seeded onto the decellularized esophagus were examined histologically and immunocytochemically. Esophageal epithelial cells were stratified into three to four cellular layers in vitro inside thedecellularized esophagus, to show polarity. The results from immunocytochemistry indicated that the seeded epithelial cells expressed characteristic marker proteins for native esophageal EP. Decellularized esophagus showed suitable compatibility as a scaffold material for esophageal tissue engineering. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res, 2006
Late Devensian and Holocene relative sea‐level changes on the Isle of Skye, Scotland, UK
Authors: Selby Katherine A. , Smith David E. 
Published: July 2006

AbstractDetailed litho‐ and biostratigraphical analyses from three coastal sites in contrasting coastal settings on the Isle of Skye, Scotland, UK, reveal evidence for several changes in relative sea level during the Late Devensian and Holocene. At the start of the record, relative sea level in the area was high at ca. 12 500 14C (ca. 14 800 cal.) yr BP but then fell, reaching a low point during the Younger Dryas, at ca. 11 000–10 000 14C (ca. 13 000–11 600 cal.) yr BP, when a rock platform, correlated with the Main Rock Platform, was formed. In the early–middle Holocene, relative sea level was rising by ca. 8000 14C (ca. 8800 cal.) yr BP and in northeast Skye a lagoonal surface, correlated with the Main Postglacial Shoreline, was formed at ca. 6600 14C (ca. 7500 cal.) yr BP. By the late Holocene, relative sea level was again falling, but a rise, registered at at least two sites, began probably before ca. 4000 14C (ca. 4500 cal.) yr BP, and a second lagoonal surface in northeast Skye, correlated with the Blairdrummond Shoreline, was formed, although by ca. 3000 14C (ca. 3200 cal.) yr BP relative sea level in the area had resumed its downward trend. The pattern of relative sea‐level changes disclosed is compared with evidence elsewhere in Scotland. Copyright © 2006 John Wiley & Sons, Ltd.
Development and characteristics of a fire‐resistant grease
Authors: Jones J. A. , Macphail A. C. B. 
Published: July 2006

AbstractTo reduce the incidence of fires in coal‐mines, the British National Coal Board (NCB) has requested a fire‐resistant grease which would be used in conveyor idler bearings and which would give the performance of good mineral oil‐based greases. A candidate grease was produced by the authors' company, based on phosphate ester, which is under field test by the NCB and running satisfactorily after one year. The results are encouraging so that consideration is being given to use of this type of grease in other applications.
Ester base stocks
Authors: Szydywar J. 
Published: July 2006

AbstractNatural esters contained in animal fats such as sperm oil, lard oil or in vegetable oils like rapeseed and castor oil have been the main lubricants from antiquity until the early 19th century. By 1890, petroleum oils had almost completely displaced natural oils. However, fatty products were still used as ‘oiliness agents’ to reduce friction and wear in bearings and gears lubricated by petroleum products. About 1937, Dr Herman Zorn of IG Farben Industrie in Germany began an intensive search for lubricants having the lubricating properties of natural oils, such as castor oil, while eliminating the tendency of these natural products to gel at low temperatures and to form gums and lacquers when used in engine operation. This paper describes the properties, types and applications of esters, as a main group of synthetic lubricants developed during the last four decades.
COBRA analysis of laboratory degraded synthetic turbine engine lubricants
Authors: Centers Phillip W. , Smith Hoover A. 
Published: July 2006

AbstractThe Complete Oil Breakdown Rate Analyser (COBRA) is an instrument that detects ill‐defined electrochemical changes in synthetic ester‐based lubricants as those fluids are oxidatively degraded. In several Air Force field applications, the COBRA has proven useful in determining lubricant condition or in identifying abnormally operating engines in which excessive lubricant degradation occurred. In laboratory analyses of field samples from programmes involving several engine types, correlation of COBRA with total acid number or viscosity was poor, but consumption of one or more oxidants appeared to be consistently associated with high COBRA values. To determine if such correlation exists, this study was conducted to evaluate laboratory degraded synthetic lubricants. Results of the laboratory study indicate that COBRA increases rapidly after depletion of typical antioxidants, increases with higher total acid numbers and trends with viscosity data. The poor correlation observed between COBRA and total acid number and viscosity for field samples is attributed to differences in for example engine breather designs, and oxidative environments, which can significantly alter the properties of the residual engine lubricant analysed by COBRA. Due to the presumed test apparatus and engine design dependence of COBRA data, COBRA correlation must be established for each application.
The relationships between structure and rheological properties of hydrocarbons and oxygenated compounds used as base stocks
Authors: Denis J. 
Published: July 2006

AbstractThe growing interest shown by industry in synthetic lubricants for severely stressed engines and machines has led the author's organisation to investigate the best hydrocarbon and oxygenated structures which serve to achieve a good compromise between viscosity index and pour point. Several analyses of structure and property relationships have been published. The American Petroleum Institute's project 421 has given the characteristics of many light hydrocarbons from C10 to C35 belonging to different chemical families. During the Second World War, American and German research centres investigated a large number of esters and selected the best diacid and polyol ester structures.The compromise between the viscosity index and pour point has been studied for hydrocarbons and oxygenated products as to their prospects for use as base stocks. With hydrocarbons having a long main chain which is substituted either by a very branched chain, or by a chain ending with a saturated ring, it is possible to reach a viscosity index of around 160 for a pour point of −20°C. The introduction of ester functions in a hydrocarbon chain improves the compromise between viscosity index and pour point. Diacid esters constituted of linear diacids and branched monoalcohols are very favourable, but the best compromise is achieved by polyalkoxy
‐ether‐esters and polyalkoxy diesters. Unhappily these are miscible to hydrocarbons only if the hydrocarbon chains are sufficiently long. Of course for formulation of lubricants, other properties also linked to chemical structure should be taken into account, such as thermal and oxidative stability, antiwear behaviour, hydrolytic stability, and compatibility with additives.The data presented here and other data derived from research projects conducted in the author's laboratory, some jointly with Produits Chimiques Ugine Kuhtmann, have been analysed to determine the possibilities for main synthetic lubricant base stocks.
Thermal oxidative ageing of neopentylpolyol ester oils: Evaluation of thermal‐oxidative stability by quantitative determination of volatile ageing products
Authors: Zeman A. , Koch K. , Bartl P. 
Published: July 2006

AbstractDuring thermal‐oxidative ageing of pentaerythritol ester‐based oils a variety of volatile degradation products, eg acids, aldehydes, ketones, esters and O‐heterocyclic compounds are produced. It is shown that quantitative determination of individual acids and carbonyls using GC‐MS and/or HPLC can be used to assess the ageing behaviour of fully formulated aviation turbine oils. Of special importance is the Tenax‐GC method which allows a simultaneous determination of all volatile degradation products by GC‐MS. This is the third of a series of papers on thermal‐oxidative ageing of neopentylpolyol ester oils.1,3
The action of organo‐phosphate additives in polysiloxane fluids
Authors: Conte Alfeo A. 
Published: July 2006

AbstractThe four ball wear test apparatus was used to study the antiwear properties of four organo‐phosphate additives in dimethyl‐, phenyl methyl‐, and two chlorophenyl methyl siloxane fluids as a function of load, additive concentration and viscosity. In most cases an antagonistic ‘prowear’ effect is observed refuting the commonly held belief that the lack of antiwear activity is the result of the additive not getting to the surface or being displaced from the surface by polysiloxane fluids.
Performance testing of a multiservice synthetic grease for industrial and automotive use
Authors: Baudouin P. , Cholcha G. , Raich H. 
Published: July 2006

AbstractThis paper describes Grease A, a high drop point PAO type grease with multiservice capability, developed to fill the performance/cost gap which has existed in industrial and automotive applications between mineral‐based multiservice greases and synthetic greases, either specialised, or with multiservice capability orientated towards military applications, and usually expensive. It also briefly gives details on Grease B and Grease C, two other greases based on the same chemistry as Grease A, developed for very specialised and severe applications which cannot be covered by a multiservice grease, even synthetic, such as Grease A.
The influence of molecular structure on the frictional behaviour of lubricating fluids 2: Low coefficients of traction
Authors: Hentschel K.‐H. 
Published: July 2006

AbstractIn order to establish correlations between the chemical structure or constitution of fluid lubricants and their friction characteristics under elastohydrodynamic conditions, a number of model test fluids were tested in a twin‐disk machine. As test fluids, special saturated monobi‐, and tricyclic compounds, alkanes and polyethers were selected. The traction coefficients were shown to be strongly dependent on the chemical structure of the lubricants and on operational parameters. High coefficient values mostly arise from lubricant molecules that are shaped irregularly, with indentations and teeth as seen with Stuart‐Briegleb models, and allowing only heavily hampered rotational intramolecular motions along single bond axes. Low traction coefficients derive from lubricant molecules with a thread‐like shape and a minimum of structural subunits or functional groups involved in significant intermolecular interactions. In order to account for the results obtained, several paradigms and hypotheses are established and discussed in detail.
Analysis of the ester constituents of synthetic and semi‐synthetic oils
Authors: Forestière A. , Hipeaux J. C. , Denis J. 
Published: July 2006

AbstractThe analysis of lubricating oils commonly practised in petroleum laboratories is important in following the evolution of products available on the market. Several analysis methods have been proposed, particularly by Van Rysselberge, 1 Amos2 and Coates.3 All these extremely useful methods make use of conventional separation and identification techniques such as molecular distillation, dialysis, bydrolysis, chromatographic techniques, spectragraphic techniques and chemical methods for determining functional groups. Their main aim is to identify the different types of additives present in lubricants.For several years now, however, base stocks have also been composed of synthetic products. Therefore, it seems important to add a simple method of ester identification to these analytical methods. Esters are normally analysed by saponification (to determine water‐insoluble acids and polyols) and by hydrolysis (for water‐soluble alcohols). Yet a complete reduction transforming constituent acids into alcohols simultaneously reveals all the elements making up an ester. Its reconstitution is then relatively easy. This reduction technique can be applied not only to esters but also to polymethacrylates used as viscosity index improvers and to antioxidant zinc dithiophosphates.
Aircraft engine oils and their behaviour at high temperatures
Authors: Maier K. 
Published: July 2006

AbstractThe characteristics of aero‐engine oils are changed considerably under high‐temperature conditions (≧ 200–250°C). The consequences of this are the formation of ageing products and deposits, deficiencies in tribological behaviour, and spontaneous ignition in extreme cases. The problems arising from these are illustrated using several selected examples, and their effects on engine functioning are described.
Future helicopter transmission oils
Authors: Spikes H. A. 
Published: July 2006

AbstractFor many years helicopter transmissions have shown low reliability relative to planned overhaul lives and to other comparable lubricated systems. Reasons for this include the extremely wide range of conditions encountered by the lubricant in helicopter transmissions and also the requirement that, in many cases, the oil be common to both transmission and gas turbine engines.Recently acquired understanding of lubrication mechanisms shows that potential exists both for improved performance and for the ability to cater for higher temperatures by the development of new helicopter transmission oils based on synthetic lubricants.This paper discusses the particular lubricating problems associated with helicopter transmission lubrication and describes test methods and formulation approaches to improving such lubricants.
PAH emissions of synthetic organic esters used as lubricants in a two‐stroke engine
Authors: Cosmacini E. , Cottica D. , Pozzoli L. , Leoni R. 
Published: July 2006

AbstractIn this paper are presented some results of research into gaseous emissions from a two‐stroke engine. These engines require a particular fuel consisting of a mixture of petrol and lubricating oil. In the research, a comparison was made between fuel mixtures containing mineral and synthetic base‐stock lubricants, in order to check the chemical differences between exhaust emissions from the same motor run under the same conditions. This comparison was made because synthetic lubricants based on organic carboxylic esters, when compared to mineral ones, have some peculiar properties: a smaller combustion residue, better lubricating ability and better thermal stability. There are therefore good reasons to suppose that the lubricant fraction of fuel mixtures, after combustion, may cause gaseous emissions whose composition may vary according to the lubricant used.
Military aircraft propulsion lubricants–current and future trends
Authors: Beane G. A. , Gschwender Lois J. , Snyder Carl E. , Shimski John T. 
Published: July 2006

AbstractAn assessment of the performance of MIL‐L‐7808J and MIL‐L‐23699C Military Specification lubricating oils in turbine engines and helicopter gear boxes is presented along with predicted performance of current and upgraded military specification oils in advanced and ‘growth’ engine designs. Data is presented on advanced ester base engine lubricants, corrosion inhibited engine oils, and separate helicopter gear box oils evolving from current developmental research efforts. Future high temperature candidate fluids representing the ultimate stability for turbine engine oils are also discussed. Their use, in most cases, entails engine design considerations to accommodate their unique properties. The advantages and disadvantages of the various classes of synthetic lubricants for turbine engine applications are discussed, and deficiencies are identified where additional research programmes are needed.
Biodegradability test for synthetic esters
Authors: Versino C. , Novaria M. 
Published: July 2006

AbstractVarious synthetic esters were tested for their biodegradability, using a test sequence that began with the creation of biomass using sucrose and municipal wastewater; biodegradation was measured using biochemical oxygen demand and chemical oxygen demand values. The test esters and resulting extractable matter were analysed by spectrophotomety. The esters were found to be biodegradable, to different degrees, subject to the presence of large amounts of water and the correct saline nutritive substratum.
Synthetic lubricants in India — an overview
Authors: Rao A. Madhusudhana , Srivastava S. P. , Mehta K. C. 
Published: July 2006

AbstractDifferent synthetic products currently available and which find wide application as lubricants, are described, and their merits and demerits compared with the mineral based lubricants are outlined. Some of the major synthetic lubricants used in Indian industries are identified. The Indian chemical industry's potential to meet some of the requirements of synthetic lubricants is discussed and the need to create additional facilities in India for the manufacture of certain critical products, is described.
Improving the performance of synthetic base fluids with additives
Authors: van der Waal G. 
Published: July 2006

AbstractBecause of their improved performance characteristics over mineral oil based lubricants, partly and fully synthetic fluids are being used more open, the main types of synthetic base fluids being esters and polyalphaolefins (PAOs). The response of additives, such as anti‐oxidants, anti‐wear additives and viscosity index improvers, to mineral oil, eslers or PAOs will obviously differ. This paper reports an attempt to find the most effective types of such additives for esters and PAOs, in order to optimize lubricant performance. PAOs have deficiencies in terms of a number of peformance characteristics, particularly with respect to additive solubility, and they are thus blended with esters to improve these properties.
Thermal oxidation behaviour of synthetic oils: Basic studies in the polymerization of polyol ester oils
Authors: Koch B. , Jantzen E. 
Published: July 2006

AbstractThe oxidation behaviour of synthetic oils has been extensively studied during recent decades, and there is general agreement on both the mechanism and products of the oxidative degradation of oils. However, the other phenomenon of oil ageing, polymerization has been little studied. These polymers are responsible for the increase of viscosity, production of sludge and the formation of deposits. In the investigation reported here, oligomers have been isolated and studied at an early ageing stage. The dependence of viscosity on the degree of polymerization is demonstrated. A polymerization mechanism and a monomer for polyolester oils are proposed and discussed.
The hydrolytic stability of aircraft coolant/dielectric fluids
Authors: Conte Alfeo A. , Ruzansky Martin , Chen Richard 
Published: July 2006

AbstractThe change in flashpoint, volume resistivity and dielectric strength of 2‐ethylbutyl silicate ester (2‐EBSE) based and 1‐decene dimer polyalphaolefin (PAO) based fluids were measured as a function of initial water content and temperature. The PAO fluid was found to be stable while the 2‐EBSE fluid degraded to alcohol which significantly reduced its flashpoint. This was found to occur even with trace quantities of water present. Volume resistivity and dielectric strength were shown to be inadequate monitoring techniques for determining the extent of hydrolytic degradation.
Soft layer lubrication of artificial hip joints
Authors: Unsworth A. , Pearcy M. J. , White E. F. T. , White G. 
Published: July 2006

AbstractAn experimental study of the lubrication mechanisms existing in prototype artificial hip joints which have compliant surface linings, has shown that for a lining with a hardness of about 4N/mm2, fluid film lubrication can be achieved even with the low viscosity synovial fluid present in diseased joints after surgery. In tests, a synthetic lubricant was used in place of the synovial fluid. The best results seem to be produced with a 2 mm thick layer.
Evaluation of ferrofluids as lubricants
Authors: Deysarkar Asoke K. , Clampitt Bert H. 
Published: July 2006

AbstractA ferrofluid is a colloidal suspension of up to 10% magnetic particles in a carrier fluid, which may be mineral or synthetic. The resultantfluids have many applications, for example where a magnetic field is present. A study was conducted of the effects of the nature of the carrier fluid and particle diameter on the viscosity build‐up characteristics of the ferrofluid in the presence of a magnetic field, and the results are presented. Tests were also carried out on a 4‐ball machine.
Influence of counterface roughness on the friction and wear of polytetrafluorethylene‐ and polyacetal‐based composites
Authors: Tanaka K. , Yamada Y. 
Published: July 2006

AbstractThe friction of various composites is generally little dependent upon the roughness. When the composites contain glass or carbon fibres, their wear rates are also little dependent upon the roughness. However, the wear rates of PTFE incorporating MoS2, graphite or bronze and polyacetal incorporating PTFE increase rapidly as the roughness increases beyond a certain critical value characteristic of each of these composites. The roughness‐dependency of the wear rate is markedly affected by the transfer during sliding.
Waste treatability of aqueous based synthetic metal‐working fluids
Authors: Napier S. , Cattell H. G. , Coffin P. S. 
Published: July 2006

AbstractSynthetic coolants for the metalworking industry represent a wide array of chemical designs. The chemical types generally found in commercially available synthetic coolants are reviewed in terms of their treatability and their effect on the environment. Waste treatment schemes are discussed for two simple examples of anionic and nonionic aqueous based synthetic coolants respectively. The results obtained show that synthetic coolants may be successfully waste treated by conventional means. Total Organic Carbon (TOC) and Chemical Oxygen Demand (COD) are considered to be key parameters for measuring the waste‐treatability of aqueous synthetic coolants.
Development of high dilution, low pollution out‐board oils
Authors: Kenbeek D. , van der Waal G. 
Published: July 2006

AbstractTwo‐stroke outboard engines have long been considered noisy and polluting devices. However, attitudes towards these engines are changing thanks to the introduction of new engine designs and high dilution, low pollution outboard oils. In this paper the development of such oils is described. It is shown that using esters, with their excellent lubricity and inherent biodegradability, it is possible to formulate outboard oils with high performance in all respects.When these oils are combined with automated oil supply systems, to avoid misblending and oil spillage, an optimal and environmentally friendly system is obtained. It is, however, desirable that appropriate legislation is established to speed up the introduction of these systems.