Academic literature on the topic 'Air Base Sembach (Germany)'

Utilization of optical fiber involves two problems: the use of a protective shell (mainly various types of plastics) and the actual optical fibersquartz filaments with an admixture of germanium dioxide coated with a protective layer of polyethylene. The aim of the work was to study the physical and chemical properties of samples of optical fiber wastes. The behavior of the components of this material has been studied by thermography: a quartz germanium-containing glass and a polyethylene sheath during heat treatment. It has been established that in the temperature range from 20 to 700 °С in the atmosphere of the air quartz fiber does not undergo changes, and the polyethylene shell of the optical fiber passes through the stages of sorption of water vapor and air oxygen at 125 and 200 °С during melting, and above 300 °С – destruction with a mass loss of up to 55 % and the release into the gas of products of oxidative degradation.

IntroductionIn Germany, emergency medical care is provided by ambulances. Emergency physicians also are used in the German rescue system to ensure primary care. Additionally, rescue helicopters are insertable. The rescue helicopter in Dresden covers the city of Dresden and its surrounding areas, with 517,000 inhabitants and distances up to 70 km. The goal of this study was to evaluate emergency cases in helicopter rescue missions according to primary diagnoses and severity of the mission on the basis of NACA Score.MethodsData from all emergencies using the German Air Rescue (DRF-Luftrettung) Helicopter Base Dresden were recorded on a standardized protocol and transferred to a central computer database (MEDAT®). Data from all emergency cases between January 2006 and July 2010 were analyzed.ResultsThere was a total of 6,310 emergencies during the study period, with a significant increase over time. The helicopter was on-scene within 10.9 minutes. In total, 54% of the patients were male. The rate of female patients > 80 years of age was 64.5%. A total of 63.4% of patients suffered life-threatening injuries or dysfunctions and a NACA score ≥ 4. A total of 7.6% of patients were classified in NACA 6 or 7. The most common cause for rescue missions was an acute coronary syndrome (20.4%). Other frequent diagnoses included brain injury (13.3%), unconsciousness (12.5%), stroke (12.9%), general cerebral convulsion (7.9%), polytrauma (6.4%), and cardiac arrest (5.0%). The rate of prehospital endotracheal intubation was 15.1%. In 1.1% of patients, a thoracic drainage was established.ConclusionsIn recent years the number of helicopter rescue missions increased, along with injury severity. The total number of patients with NACA 6 and 7 was extremely high, and demonstrates the need for an efficient emergency medical rescue system that includes helicopters.

Abstract In the mammal collection of the Museum für Naturkunde Berlin (MfN), Germany a serious but inconspicuous deterioration of mammal skins and hides has been detected. The tear strength has been decreasing until the skins are falling apart, risking permanent loss of valuable specimens. At the MfN, about 80% of the 30,000 skins are affected. Although this phenomenon has been known by taxidermists for some time, there are very few publications on the subject. In this study, we surveyed the literature and conducted interviews with collections and leather industry professionals to understand the extent and potential causes of skin deterioration. In addition, analyses of skins in the collections of the MfN and the ZFMK (Bonn, Germany) showed that more than 80% of the tested skins had a very low tear strength. The tear strength appears correlated with the pH value and age of the skin. Our findings suggest that surplus acid from residual fat, preservation methods, or external sources such as air pollution might be a primary source of the degradation. Future steps should include further research on the chemical processes involved in deterioration, treatment options for threatened skins, and development of best practices, protocols for documentation, and development of a publicly available online knowledge base for museum skin preparation, preservation, and storage methods.

We investigated the prevalence of hepatitis B virus (HBV) and hepatitis C virus (HCV) serological markers of infection in young adults from the metropolitan region of Florianópolis who were conscripts of the Air Base of Florianópolis in the state of Santa Catarina, Brazil. A population-based cross-sectional seroprevalence study was conducted with 371 young males during a one year period starting in June 2009. Demographic characteristics, socio-economic characteristics and possible risk factors to HBV and HCV were assessed. Blood samples were analyzed for HBsAg, anti-HBc, anti-HCV and anti-HBs through automated microparticle enzymatic immunoassays (Abbott®, AxSYM System, Wiesbaden, Germany). None of the participants showed positivity to HBsAg or anti-HCV. The prevalence of anti-HBc was 1.6% (95% CI 0.6 - 3.5), and the prevalence of anti-HBs was 40.7% (95% CI 35.7 - 45.9). Unsafe sex was associated with positive anti-HBc in a bivariate analysis. There was a very low prevalence of past HBV infection and no cases of past HCV infection in a young adult population in the metropolitan region of Florianópolis. The very low prevalence of markers of infection and risk factors indicates a very optimistic future with respect to HBV and HCV infection in this population.

Abstract. Twenty nine cases of layered liquid-water cloud systems were observed with dual-field-of-view (dual-FOV) Raman lidar over the polluted central European site of Leipzig, Germany, between September 2010 and September 2012. For the first time, a detailed lidar-based study of aerosol-cloud-dynamics relationship was conducted. A collocated Doppler lidar provided information on vertical velocity and thus on updraft and downdraft occurrence. The novel dual-FOV lidar permits the retrieval of the particle extinction coefficient (used as aerosol proxy just below cloud base) and cloud properties such as droplet effective radius and cloud droplet number concentration in the lower part of optically thin cloud layers. Here, we present the key results of our statistical analysis of the 2010–2012 observations. Besides a clear aerosol effect on cloud droplet number concentration in the lower part of the convectively weak cloud layers during updraft periods, meteorological effects (turbulent mixing, entrainment of dry air) were found to diminish the observable aerosol effect higher up in the clouds. The corresponding aerosol-cloud interaction (ACI) parameter based on changes in cloud droplet number concentration with aerosol loading was found to be close to 0.8 at 30–70 m above cloud base during updraft periods which points to values around 1 at cloud base (0–30 m above cloud base). Our findings are extensively compared with literature values and agree well with airborne observations. As a conclusion, ACI studies over continental sites should include vertical wind observations to avoid a~bias (too low values) in the obtained ACI results.

Abstract. For the first time, a liquid-water cloud study of the aerosol–cloud-dynamics relationship, solely based on lidar, was conducted. Twenty-nine cases of pure liquid-water altocumulus layers were observed with a novel dual-field-of-view Raman lidar over the polluted central European site of Leipzig, Germany, between September 2010 and September 2012. By means of the novel Raman lidar technique, cloud properties such as the droplet effective radius and cloud droplet number concentration (CDNC) in the lower part of altocumulus layers are obtained. The conventional aerosol Raman lidar technique provides the aerosol extinction coefficient (used as aerosol proxy) below cloud base. A collocated Doppler lidar measures the vertical velocity at cloud base and thus updraft and downdraft occurrence. Here, we present the key results of our statistical analysis of the 2010–2012 observations. Besides a clear aerosol effect on cloud droplet number concentration in the lower part of the altocumulus layers during updraft periods, turbulent mixing and entrainment of dry air is assumed to be the main reason for the found weak correlation between aerosol proxy and CDNC higher up in the cloud. The corresponding aerosol–cloud interaction parameter based on changes in cloud droplet number concentration with aerosol loading was found to be close to 0.8 at 30–70 m above cloud base during updraft periods and below 0.4 when ignoring vertical-wind information in the analysis. Our findings are extensively compared with literature values and agree well with airborne observations.

Abstract Cabbage plants in pots were inverted and dipped in 1.5 liters of a solution of Neem Azal-T (Trifolio-M GmbH, Germany). Neem Azal-T contains 5% azadirachtin, generally considered the active ingredient in neem extracts. Neem Azal-T was diluted in water at concentrations of 0, 0.25, 0.5, 1, 2, 4, 8 and 16 ppm azadirachtin. Each plant was held in the solution for 60 sees. After dipping, the plants were set in a screened insectary to dry for 3 hours, cabbage moth larvae in the early 2nd instar were placed in net bags, 20 larvae per bag, and the bags were placed over each plant and secured at the base of the stem. The plants were arranged on the concrete insectary floor in a RCB design with 5 replications. The average air temperature during the experiment was 15.5°C. The average day length was 18 h. The experiment lasted 16 days, at which time larval mortality was assessed.

AbstractAlthough current upper-air observing systems provide an impressive array of observations, many are deficient in observing the temporal evolution of the boundary layer thermodynamic profile. Ground-based remote sensing instruments such as the multichannel microwave radiometer (MWR) and Atmospheric Emitted Radiance Interferometer (AERI) are able to provide profiles of temperature and water vapor through the boundary layer at 5-min resolution or better. Previous work compared these instruments through optimal-estimation retrievals on simulated clear-sky spectra to evaluate the retrieval accuracy and information content of each instrument. In this study, this method is duplicated using real observations from collocated MWR and AERI instruments from a field campaign in southwestern Germany. When compared with radiosondes, this study confirms the previous results that AERI retrievals are more accurate than MWR retrievals in clear-sky and below-cloud-base profiling. These results demonstrate that the AERI has nearly 2 times as much information as the MWR.

ABSTRACTThe moth Malacosoma castrensis (Lasiocampidae) is commonly found along the Northern Germany coasts, the habitats of which are mainly represented by salt marshes subjected to sea level variations. Surprisingly, terrestrial caterpillars can withstand many hours of being flooded by seawater. The ability to withstand periods of submersion in a terrestrial insect raises the problem of respiration related to avoiding water percolation into the tracheal system. In the present study, we investigated under laboratory conditions the role of water-repellent cuticle structures in oxygen supply in caterpillars of M. castrensis submerged in water. For this purpose, air-layer stability tests using force measurements, and micromorphology of cuticle structures using SEM and fluorescence microscopy, were performed. A plastron appeared when a caterpillar is underwater. The stability, gas composition and internal pressure of the plastron were estimated. The plastron is stabilized by long and scarce hairs, which are much thicker than the corresponding hairs of aquatic insects. Thick and stiff hairs with sclerotized basal and middle regions protrude into the water through the plastron–water interface, while substantial regions of thin and flexible hairs are aligned along the plastron–water interface and their side walls can support pressure in the plastron even below atmospheric pressure. Additional anchoring points between hair's stalk and microtrichia near the hair base provide enhanced stiffness to the hair layer and prevent the hair layer from collapse and water entering between hairs. The advancing contact angle on hairs is more than 90 deg, which is close to the effective contact angle for the whole caterpillar.

IntroductionIn Germany, emergency physicians in the prehospital rescue system ensure primary care. The rescue helicopter in Dresden covers the city of Dresden (population 517,000), surrounding areas with distances up to 70 km. Typical reasons for alerting the rescue helicopter are heart diseases or injuries during accidents. There also is a high number of patients with attempted or completed suicides. The goal of the study was to analyze cases associated with suicide.MethodsData of all emergency transports from the German Air Rescue (DRF-Luftrettung) Helicopter Base Dresden between January 2008 and December 2009 were recorded on a standardized protocol and transferred to a central computer database. Subsequently, all cases were analyzed with special regard to suicides.ResultsThere were a total of 3,051 cases during the study period. Fifty-nine cases (1.9%) were related to suicide. The helicopter was on the scene within 10.9 minutes. The mean NACA Score was 4.9. The mean age was 51.6. A total of 52.5% of patients were male. In 15.2% of the cases, the patient called for emergency help; in 37.3%, bystanders contacted authorities. The reason for attempted suicide was unknown in 57.6% of the cases. In 16.9%, it was related to partnership, in 20.3% to health problems, in 5.1% to financial problems. The main method of attempt was the use of medical pills (47.4%). Other frequent methods were strangulation (18.6%), stab wounds and gunshots (8.5%), intoxication (3.4%), or unknown (16.9%). Six patients received cardiopulmonary resuscitation, four reached a Return of Spontaneous Circulation, and 10 patients died.DiscussionHelicopters often transport suicide victims. This study demonstrates the need for better prevention as well as an improvement of education for emergency physicians working in the prehospital setting.

This chapter examines to what extent Europe’s governments and defence contractors cooperate to provide European Armed Forces with military capabilities. Defence industrial cooperation has evolved as almost the default policy option for European powers to develop large military platforms. Yet, there is no uniform trend, but large variation across countries (for example, France versus Germany), across sectors (land versus air versus sea), and with regards to the sources of cooperation (for example, government induced versus investment driven). The chapter shows that, while the major powers dominate defence industrial cooperation both at the government and at the corporate level, the lesser powers and smaller defence firms follow the trend and participate in the supply chains of large weaponry. Finally, the chapter addresses the question whether cooperation or competition represents the most promising strategy towards a capable European Defence Technological and Industrial Base.

Back in the halcyon days of 1951, when the United States was entering its golden years of wealth and power and proclaiming that this was the American Century, there seemed no limit to what we could do with nature. Were some climates too hot? We could air-condition them. Were some too cold? We could thaw them out or raise tomatoes under glass. Were some too dry? We could, through hydraulic engineering, make them over into a veritable Eden of delights. In that year a Time magazine reporter traveled to the arid West to write about “the endless frontier” being won there by the engineers of the Bureau of Reclamation. They promised to develop enough water to redeem fifty million acres from aridity, enough acres to feed the equivalent of a whole new nation the size of France or Germany. And the engineers were not in the least reluctant to say what pleasure they got out of the work: “We enjoy pushing rivers around,” they told the reporter. Whether the pushing had any real direction, any clear sense of ends, was secondary; they (and by extension, we Americans) were a people who enjoyed dominating nature and we would look for rationales later. In a spirit of what the magazine called “engineering ecstasy,” almost every river in the western part of the country came under control and was made to raise alfalfa, fruit, and cotton. Our agricultural base shifted abruptly westward into the desert, and eastern and midwestern farmers suffered substantial damage to their fortunes. By the last agricultural census, the West counted over 45 million irrigated acres, producing one-fourth of the nation’s annual farm market sales. Though it irrigated only a small percentage of that acreage, the Bureau of Reclamation was unexcelled among water pushers for ambition and scale. It was the Bureau that had erected some of the biggest dams ever: Hoover, Grand Coulee, Shasta, Glen Canyon, Teton, Navajo, Flaming Gorge, etc., the clearest, brightest expressions we had of our national drive to conquer the land. But the big dams were more than that.

Recent media articles about nuclear power renaissance are encouraging, but this controversial topic is far from being embraced by major industrial powers. The fact is, that within the next two to three decades or so most of the first generation US nuclear power plants, currently producing about 20 percent of the nation’s electrical power, will be near the end of their design lives. In addition to providing needed power, a major argument put forward for the introduction of next generation smaller and safer nuclear plants relates to the growing concern about greenhouse gas emission and global warming. However, overcoming public and institutional resistance to nuclear power remains a formidable endeavor, and in reality the introduction of new plants in sufficient numbers to significantly impact the market will not be realized for several decades. Clearly vision is needed to define the requirements for new nuclear plants that will meet the needs of consumers by say the middle of the 21st century. Market forces will mandate changes in the energy supply sector, and to be in concert with environmental concerns new nuclear plants must have operational flexibility. In addition to economical electrical power, energy needs in the future could include hydrogen production in slgnificant quantity (for fuel cells in the transportation and power sectors) and fresh water by desalination for urban, industrial and agricultural users. The High Temperature Reactor (HTR) has the capability to meet these projected needs. With an established technology base, and successful plant operation in Germany, the helium cooled pebble bed reactor (PBR) must be regarded as a leading second generation nuclear plant. Operational versatility by virtue of its high temperature capability is assured, and high availability can be realized with its on-line refueling approach. While the multipurpose HTR may be several decades away from playing a significant rote in the commercial market place, this paper emphasizes the need for technical planning today to establish a nuclear heat source adaptable to both a high efficiency helium timed cycle gas turbine and large scale hydrogen production facilities, thus extending the role of nuclear power beyond just the supply of electrical power.

Extensive operational performance data from the Siemens Power Generation V64.3 unit in Obernburg, Germany (operated by Kraftwerk Obernburg GmbH) is evaluated. The unit was commissioned in 1996 and has been running continuously in base load operation with fuel gas to supply heat and power to a nearby chemical plant. In rare cases, fuel oil is used as a backup fuel. During the first major outage after approx. 25000 equivalent operating hours (EOH), the Siemens PG Advanced Compressor Cleaning System (ACCS) was implemented at Obernburg. ACCS features separate nozzle systems for online and offline compressor cleaning accounting for different operating conditions. For online cleaning, the droplet size is optimised for the droplets to remain in the main air flow in order to minimize erosion effects while providing a homogeneous field over the whole air intake. With reduced rotational speed during offline compressor cleaning, erosion is less critical. Offline nozzles, therefore, provide higher mass flow and larger droplets in order to maximize cleaning performance for all compressor stages. ACCS, in its maximum automated version, features operation from the control room, online-washing at low ambient temperatures (officially released down to −15°C without GT Anti-Icing) and minimum use of manpower. The ACCS system in Obernburg was operated according to the recommended online washing procedure. By June 2002, the V64.3-unit in Obernburg reached 50000 EOH and the second major inspection was carried out. For this paper, operational data from the second inspection intervals (24350–49658 EOH) and from three performance tests with calibrated equipment are compared in order to evaluate the effectiveness of the Advanced Compressor Cleaning System. Statistical evaluation of single-wash performance recovery and the evolution of long-term performance are presented. The effects of degradation and fouling are differentiated. It is shown that ACCS has a significant benefit for long-term engine performance.

During the past 30 years many fatigue tests and fatigue analysis improvements have been developed in France in order to improve Codified Fatigue Rules of RCC-M and ASME Codes [1, 2]. This paper will present the major technical improvements to obtain reasonable evaluation of potential fatigue damage through EDF road map. Recently new results [3] confirm possible un-conservative fatigue material data: - High cycle fatigue in air for stainless steel, - Environmental effects on fatigue S-N curve for all materials - Fatigue Crack Growth law under PWR environment for stainless steel. In front of these new results, EDF has developed a “Fatigue Road Map” to improve the different steps of Codified fatigue rules. A periodic up-dating of proposed rules in the different French Codes: RCC-M, RCC-MRx and RSE-M with research of harmonization with other Code rules developed in USA, Japan and Germany in particular, will be done on a yearly basis. During the past 15 years, many results have been obtained through fatigue tests of stainless steel materials: - mean and design fatigue curve in air, - environmental effects on fatigue curves, - plasticity effects, - bi-axial load effects, - mean stress effects, - stress indices, - transferability from small to large specimen, - weld versus base metal. In parallel, many new developments have been made in non-nuclear pressure equipment industry: like the reference stress of ASME Section VIII or the structural stress of EN 13445. These methods are mainly well adapted to fatigue pressure cycling. In front of that situation, the French nuclear code organization needs to propose reliable rules for new design and for operating plants. Different proposals are under discussion and the status of the EDF proposals are presented in the paper. The consequences could be important for the utilities because a large part of the in-service inspection program is connected to some fatigue usage factor level between 0.5 and 1.

Abstract The fatigue assessment of safety relevant components is of importance for ageing management with regard to safety and reliability of nuclear power plants. For reactor internals, austenitic stainless steels are often used due to their excellent mechanical and technological properties as well as their corrosion resistance. During operation the material is subject to loadings in the Low Cycle Fatigue (LCF) regime due to start up and shut down procedures as well as high frequency loadings in the Very High Cycle Fatigue (VHCF) regime induced e.g. by stresses due to fast cyclic thermal fluctuations triggered by fluid dynamic processes. While the LCF behavior of austenitic steels is already well investigated the fatigue behavior in the VHCF regime has not been characterized in detail so far. Accordingly, the fatigue curves in the applicable international design codes have been extended by extrapolation to the range of highest load cycles (Fig. 1). The aim of the cooperative project of the Institute of Materials Science and Engineering (WKK), Materials Testing Institute (MPA) Stuttgart and Framatome GmbH, Germany is to create a comprehensive database up to the highest load cycles N = 2·109 for austenitic stainless steels. For this fatigue tests on metastable austenitic steel AISI 347 / 1.4550 / X6CrNiNb1810 as well as austenitic welds (Fox SAS 2-A) were performed at an ultrasonic testing system at a test frequency of 20 000 Hz to realize acceptable testing times. In addition, an induction generator was implemented in the test system to investigate the influence of operation relevant temperature of 300 °C on the fatigue behavior. The ultrasonic testing system works under displacement control. Therefore, for reliable statements on fatigue life according NUREG/CR-6909 and using of S-N-curve (total-strain amplitude vs. cycle to failure) a fictitious-elastic and elastically-plastic numerical material model was used for calculation of total-strain amplitudes based on experimental data. The results shown, that at ambient temperature (AT) and 300 °C no specimen failure occurred in the VHCF regime for the base material as well as for the welds. Consequently, for these materials a real endurance limit exists. Additionally, in a continuative test a specimen with a pre-autoclaving period in high temperature water (HTW) of 2500 hours was tested in air at a total strain amplitude of 0.1 % in the VHCF-regime up to number of cycle N = 109 using an ultrasonic fatigue testing system. The chemical composition of the HTW for the pre-autoclaving period is comparable to near operation conditions. Afterwards by using of scanning electron microscope no defects or cracks were detected in the oxide layer.

Over the last two and a half years, Covanta Energy, working with their technology partner, Martin GmbH of Germany, has developed and commercialized a new technology for reducing NOx emissions from Energy from Waste (EfW) facilities. NOx levels below 60 ppm (7% O2) have been reliably achieved, which is a reduction of 70% below the current EPA standard and typical levels of today’s EfW facilities in the United States. This technology represents a significant step forward in NOx control for the EfW industry. The technology, known as VLN™, employs a unique combustion system design, which in addition to the conventional primary and secondary air streams, also features a new internal stream of “VLN™-gas,” which is drawn from the combustor and re-injected into the furnace. The gas flow distribution between the primary and secondary air, as well as the VLN™-gas, is controlled to yield the optimal flue gas composition and furnace temperature profile to minimize NOx formation and optimize combustion. The VLN™ process is combined with conventional, aqueous ammonia SNCR technology to achieve the superior NOx performance. The SNCR control system is also integrated with the VLN™ combustion controls to maximize NOx reduction and minimize ammonia slip. A simplified version of the process, known as LN™, was also developed and demonstrated for retrofit applications. In the LN™ process, air is used instead of the internal VLN™ gas. The total air flow requirement is higher than in the VLN™ process, but unchanged compared to conventional systems, minimizing the impact on the existing boiler performance and making it ideal for retrofit applications. Covanta first demonstrated the new VLN™ and LN™ processes at their Bristol, Connecticut facility. One of Bristol’s 325 TPD units was retrofitted in April of 2006 to enable commercial scale testing of both the VLN™ and LN™ processes. Since installing and starting up the new system, Bristol has operated in both VLN™ and LN™ modes for extended periods, totaling more than one year of operation at NOx levels at or below 60 ppm (7% O2). The system is still in place today and being evaluated for permanent operation. Based on the success of the Bristol program, Covanta installed LN™ NOx control systems in a number of other existing units in 2007 and 2008 (total MSW capacity of over 5000 TPD), and is planning more installations in 2009. All of these retrofits utilize the Covanta LN™ system to minimize any impacts on existing boiler performance by maintaining existing excess air levels. Going forward, Covanta is making the LN™ technology available to its existing client base and is working with interested facilities to complete the necessary engineering and design modifications for retrofit of this innovative technology. For new grassroots facilities, Covanta is offering the VLN™ system with SNCR as its standard design for NOx control. An additional feature, particular to VLN™, is the reduced total combustion air requirement, which results in improved boiler efficiency. This translates into increased energy recovery per ton of waste processed. In addition to introducing the VLN™ and LN™ processes, this paper will provide an overview of the Bristol development and demonstration project. NOx and NH3 slip data from Bristol will be presented, illustrating the extended operating experience that has been established on the system. Other operating advantages of the new technology will also be discussed, along with lessons learned during the start-up and initial operating periods. The VLN™ technology has been demonsrated to decrease NOx emissions to levels well below any yet seen to date with SNCR alone and is comparable to SCR-catalytic systems. The result is a significant improvement in NOx control for much less upfront capital cost and lower overall operating and maintenance costs. VLN™ also also goes hand in hand with higher energy efficiency, whereas SCR systems lower energy efficiency due to an increased pressure drop and the need for flue gas reheat. The commercialization of the VLN™ and LN™ processes represents a significant step forward in the reduction of NOx emissions from EfW facilities.

In recent years, legislative authorities in the US, Europe and Japan have steadily reduced engine exhaust emissions, i.e., carbon monoxide (CO), hydrocarbons (HC), sulphur, particulate matter (PM) and nitrogen oxides (NOx) to improve air quality. To meet these requirements engine manufacturers have had to make significant design changes and as a consequence new engine lubricant specifications from Industry bodies (ACEA, EMA, JAMA) and individual OEMs have had to be introduced to ensure adequate lubrication of these new engines. This has led to significant changes to heavy-duty diesel engine oil (HDDEO) oil formulation composition. Engine design modifications to increase fuel combustion efficiency such as increased peak cylinder pressure and increased fuel injection pressures have placed higher stress on piston rings and liners, bearings and valve train components [1], and improved oil consumption has meant longer oil residence time in the piston ring belt area. The practice of retarded fuel injection timing and exhaust gas recirculation (EGR) as measures to reduce NOx levels by reducing peak combustion temperature has had a considerable impact on lubricant performance. Retarded injection leads to higher soot levels which can cause valve train wear and piston ring liner wear and soot-induced thickening, whilst EGR leads to increased corrosive acids and wear in the combustion chamber. Currently in Europe, Euro 3 heavy-duty engines predominantly use retarded fuel injection as the primary NOx emission control strategy although there are cases where EGR is used. In the US, cooled EGR is used by most engine manufacturers to meet US 2002 emissions. HDDEO’s contain a combination of performance additives such as overbased metal detergents, dispersants, antiwear agents and antioxidants designed to provide wear protection, engine cleanliness, and control of soot contaminants and oxidation. Other additive components include selected viscosity index (VI) improvers and pour point depressants to provide necessary viscosity characteristics and shear stability, and also anti-foam agents for oil aeration control. To meet the increased demands from low emission engines, the chemical composition of the performance additives has been modified and levels increased. Current HDDEOs optimized to meet US and European specifications contain typically between 1.3 and 1.9%wt sulphated ash, 0.1–0.14%wt phosphorus and 0.3–1.1.wt sulphur. To meet the next generation emission standards, engines will require the use of exhaust after-treatment devices. In Europe, Euro 4 emission reductions for NOx and PM, scheduled for introduction in 2005, will require the use of either selective catalytic reduction, or the use of EGR in combination with a diesel particulate filter (DPF). To meet the US 2007 requirements, higher levels of EGR than currently used, in combination with DPFs, is envisaged by most engine builders. Exhaust after-treatment devices are already used extensively in some applications such as DPFs on city buses in Europe and the US. Further NOx restrictions are scheduled for Euro 5 in 2008 and USA in 2010. NOx absorber systems, although used in gasoline engines, are still under development for heavy-duty diesel engines and may be available for 2010. Some lubricant base oil and additive components from oil consumed in the combustion chamber are believed to adversely affect the performance of after-treatment devices. Ash material from metal detergents and zinc dithiophosphates (ZDTP) can build up in the channels within particulate filters causing blockage and potentially loss of engine power, leading to a need for frequent cleaning maintenance. The role of sulphur and phosphorus in additive components is less clear. Sulphur from fuel can either oxidize to sulphur dioxide and react through to sulphuric acid, which manifests itself as particulate, or can have a poisoning effect on the catalyst itself. However, the role of sulphur containing additives is yet to be established. Phosphorus from ZDTP antiwear components can lead to a phosphate layer being deposited on catalyst surfaces, which may impair efficiency. Concerns from OEMs regarding the possible effects of ash, sulphur and phosphorus has led to chemical limits being introduced in some new and upcoming engine oil specifications. The ACEA E6 sequence restricts sulphated ash to 1.0%wt max, phosphorus to 0.08%wt max and sulphur to 0.3%wt max, while the PC-10 category scheduled for 2007 will have maximum limits of 1.0%wt sulphated ash, 0.12%wt phosphorus and 0.4%wt sulphur. The resulting constraints on the use of conventional overbased metal detergent cleanliness additives and zinc dithiophosphate antiwear additives will necessitate alternative engine oil formulation technologies to be developed in order to maintain current performance levels. Indeed, performance requirements of engine oils are expected to become more demanding for the next generation engines where emissions are further restricted. If absorbers become a major route for NOx reduction, limits on sulphur and phosphorus are likely to be more restrictive. Oil formulations meeting ACEA E6 and PC-10 chemical limits have been assessed in several key critical lubricant specification tests, looking at valve train and piston ring/cylinder liner wear, corrosive wear in bearings, piston cleanliness and soot-induced viscosity control. It is demonstrated that it is possible to achieve MB 228.5 extended oil drain performance and API CI-4 wear, corrosion and piston cleanliness requirements for current US engines equipped with EGR [2], at a sulphated ash level of 1.0%wt, and phosphorus and sulphur levels, (0.05 and 0.17%wt, respectively), considerably lower than these chemical limits. This is achievable by the use of selected low sulphur detergents, optimized primary and secondary antioxidant systems and non-phosphorus containing, ashless supplementary antiwear additives blended in synthetic basestocks. Field trials in several city bus fleets have been conducted to assess engine oil performance and durability using one of these low sulphated ash, phosphorus and sulphur (SAPS) oil formulations and to examine lubricant effects on particulate filter performance. Engine oil durability testing was conducted in bus fleets in Germany and Switzerland. These trials, involving over 100 vehicles, cover a range of engine types, e.g., Daimler Chrysler and MAN Euro 1, 2 and 3 and different fuel types (low sulphur diesel, biodiesel, and compressed natural gas) in some MAN engines. The fleets are fitted with continuously regenerating particulate filters either from new or retrofitted. Oils were tested at standard and extended drain intervals (up to 60 000km). Used oil analysis for iron, copper, lead and aluminium with the low SAPS oil in these vehicles have shown low wear rates in all engine types and comparable with a higher 1.8% ash ACEA E4, E5 quality oil. Soot levels can vary considerably, but oil viscosity is maintained within viscosity grade, even at 8% soot loading. TBN depletion and TAN accumulation rates are low showing significant residual basicity reserve and control of acidic combustion and oxidation products. Buses in Stuttgart and Berlin have been used to investigate lubricant ash effects of engine oil on particulate filter durability. Exhaust back-pressure is routinely measured and DPF filters removed and cleaned when back pressure exceeds 100 mbar. Comparison of rate of back pressure build up as a function of vehicle distance shows reduced back pressure gradients for the low SAPS oil relative to the 1.8%wt ash oil in both engine types looked at. An average reduction in back pressure gradient of 40% was found in buses equipped with OM 906LA engines in Berlin and 25% with OM 457hLA engines at both locations. Examination of the ash content in DPFs has shown a 40% reduction in the quantity of ash with the low SAPS oil. This investigation shows that it is possible to meet current long oil drain requirements whilst meeting chemical limits for future lubricants and provide benefits in DPF durability.