High Pressure, High Temperature Shaft Seal For A Multiphase Subsea Pump

LectureThe paper describes a totally re-engineered mechanical seal for multiphase subsea pumps with a focus on extended metal and seal face material selection as well as more stable seal behavior, achieved with a new face concept, which provides enhanced reliability and robustness. It reports the design process, starting from the project description with definition of targets followed by a theoretical evaluation of the seal performance and a description of the final design features. Increasing demand for high pressure and high temperature (HP/HT) pumps in Subsea multiphase applications requires the development of mechanical seals designed for pressure levels up to 15 kpsi and product temperatures up to 350°F with the capability to handle reverse pressure conditions. With the high pressure requirements the application of spring-energized polymer gaskets as static and dynamic secondary seals using a specific design for enhanced reverse pressurization capability were selected. To achieve enhanced robustness of the seal faces in transient dry running condition which may occur during upset conditions (such as reverse pressure) the design was optimized to include microcrystalline diamond coated seal faces. A detailed analysis of face deformation and seal performance under load with a combined structure and fluid analysis software together with an extensive test campaign and specific cooling jacket features lead to a robust mechanical seal design with optimized pressure distribution and mechanical contact zones

Qualification And Optimization Of Solid Polymer Tilting Pad Bearings For Subsea Pump Applications

LectureTilting pad bearings are used extensively in high power and/or high speed pump applications. Traditional white metallined also known as babbitted tilting pad bearings are used for oil lubricated bearings. Babbitted tilting pad bearings are not ideal for applications with low viscous lubricants, like waterbased fluids. For these applications, polymer bearings offer many advantages over traditional bearing materials including: Low friction coefficient, Higher flexibility, Wide range of operational temperature, High corrosion and chemical resistance, High shock and impact resistance, Tolerance against particle contamination, Electrical insulation. To achieve the desired improvement in performance, the material specifics of the polymer have to be carefully considered in the design process. One option available is a polymer lined tilting pad bearing which combines the excellent tribological properties of polymers and the high structural stiffness of the steel back. But a polymer lined metal pad does not provide the same equalizing effect offered by the higher compressibility of a solid polymer pad. For example the problems of an edge carrier can be reduced for a tilting pad journal bearing and the self-equalizing mechanism can be avoided for a tilting pad thrust bearing while considering the higher flexibility of solid PEEK pads. An additional advantage of a solid polymer pad is the elimination of the bonding between the polymer and the steel, so that a possible source of a bearing failure can be avoided upfront already. During a qualification test of a commercially available solid polymer tilting pad thrust bearing, the high Hertzian contact stress at the pivot let to indentations in the polymer. After a few operating hours these indentations are clearly visible and will finally lead to a complete loss of the advantages of a tilting pad bearing over a fixed geometry bearing. This lecture describes the steps involved in the optimization of the solid polymer tilting pad bearing design, with the objective to increase the reliability of the bearing assembly. The limitations of the available solid polymer tilting pad thrust bearing have been overcome by the integration of a metal reinforced pivot as mentioned by Gassmann et al. (2013). The results of the TEHD analysis presented form the base of the optimized journal and thrust bearing design. The new journal and thrust bearing design has been validated through testing of a prototype. The data collected during tests with the optimized thrust and journal bearings are in excellent agreement with the simulations. With the optimized bearing design, the limitations of the original pad design have been mitigated. The successfully qualified journal and thrust bearing are one of the building blocks required for product lubricated pumps and will be used in subsea pump applications

The nuclear immune receptor RPS4 is required for RRS1SLH1-dependent constitutive defense activation in Arabidopsis thaliana

Plant nucleotide-binding leucine-rich repeat (NB-LRR) disease resistance (R) proteins recognize specific ‘‘avirulent’’ pathogen effectors and activate immune responses. NB-LRR proteins structurally and functionally resemble mammalian Nod-like receptors (NLRs). How NB-LRR and NLR proteins activate defense is poorly understood. The divergently transcribed Arabidopsis R genes, RPS4 (resistance to Pseudomonas syringae 4) and RRS1 (resistance to Ralstonia solanacearum 1), function together to confer recognition of Pseudomonas AvrRps4 and Ralstonia PopP2. RRS1 is the only known recessive NBLRR R gene and encodes a WRKY DNA binding domain, prompting suggestions that it acts downstream of RPS4 for transcriptional activation of defense genes. We define here the early RRS1-dependent transcriptional changes upon delivery of PopP2 via Pseudomonas type III secretion. The Arabidopsis slh1 (sensitive to low humidity 1) mutant encodes an RRS1 allele (RRS1SLH1) with a single amino acid (leucine) insertion in the WRKY DNA-binding domain. Its poor growth due to constitutive defense activation is rescued at higher temperature. Transcription profiling data indicate that RRS1SLH1-mediated defense activation overlaps substantially with AvrRps4- and PopP2-regulated responses. To better understand the genetic basis of RPS4/RRS1-dependent immunity, we performed a genetic screen to identify suppressor of slh1 immunity (sushi) mutants. We show that many sushi mutants carry mutations in RPS4, suggesting that RPS4 acts downstream or in a complex with RRS1. Interestingly, several mutations were identified in a domain C-terminal to the RPS4 LRR domain. Using an Agrobacterium-mediated transient assay system, we demonstrate that the P-loop motif of RPS4 but not of RRS1SLH1 is required for RRS1SLH1 function. We also recapitulate the dominant suppression of RRS1SLH1 defense activation by wild type RRS1 and show this suppression requires an intact RRS1 P-loop. These analyses of RRS1SLH1 shed new light on mechanisms by which NB-LRR protein pairs activate defense signaling, or are held inactive in the absence of a pathogen effector

Estimating dietary intake from grocery shopping data – a comparative validation of relevant indicators in Switzerland

In light of the globally increasing prevalence of diet-related chronic diseases, new scalable and non-invasive dietary monitoring techniques are urgently needed. Automatically collected digital receipts from loyalty cards hereby promise to serve as an objective and automatically traceable digital marker for individual food choice behavior and do not require users to manually log individual meal items. With the introduction of the General Data Privacy Regulation in the European Union, millions of consumers gained the right to access their shopping data in a machine-readable form, representing a historic chance to leverage shopping data for scalable monitoring of food choices. Multiple quantitative indicators for evaluating the nutritional quality of food shopping have been suggested, but so far, no comparison has validated the potential of these alternative indicators within a comparative setting. This manuscript thus represents the first study to compare the calibration capacity and to validate the discrimination potential of previously suggested food shopping quality indicators for the nutritional quality of shopped groceries, including the Food Standards Agency Nutrient Profiling System Dietary Index (FSA-NPS DI), Grocery Purchase Quality Index-2016 (GPQI), Healthy Eating Index-2015 (HEI-2015), Healthy Trolley Index (HETI) and Healthy Purchase Index (HPI), checking if any of them performs differently from the others. The hypothesis is that some food shopping quality indicators outperform the others in calibrating and discriminating individual actual dietary intake. To assess the indicators’ potentials, 89 eligible participants completed a validated food frequency questionnaire (FFQ) and donated their digital receipts from the loyalty card programs of the two leading Swiss grocery retailers, which represent 70% of the national grocery market. Compared to absolute food and nutrient intake, correlations between density based relative food and nutrient intake and food shopping data are stronger. The FSA-NPS DI has the best calibration and discrimination performance in classifying participants’ consumption of nutrients and food groups, and seems to be a superior indicator to estimate nutritional quality of a user’s diet based on digital receipts from grocery shopping in Switzerland

Crystallization and preliminary X-ray diffraction analyses of the TIR domains of three TIR-NB-LRR proteins that are involved in disease resistance in Arabidopsis thaliana

The Toll/interleukin-1 receptor (TIR) domain is a protein-protein interaction domain that is found in both animal and plant immune receptors. The N-terminal TIR domain from the nucleotide-binding (NB)-leucine-rich repeat (LRR) class of plant disease-resistance (R) proteins has been shown to play an important role in defence signalling. Recently, the crystal structure of the TIR domain from flax R protein L6 was determined and this structure, combined with functional studies, demonstrated that TIR-domain homodimerization is a requirement for function of the R protein L6. To advance the molecular understanding of the function of TIR domains in R-protein signalling, the protein expression, purification, crystallization and X-ray diffraction analyses of the TIR domains of the Arabidopsis thaliana R proteins RPS4 (resistance to Pseudomonas syringae 4) and RRS1 (resistance to Ralstonia solanacearum 1) and the resistance-like protein SNC1 (suppressor of npr1-1, constitutive 1) are reported here. RPS4 and RRS1 function cooperatively as a dual resistance-protein system that prevents infection by three distinct pathogens. SNC1 is implicated in resistance pathways in Arabidopsis and is believed to be involved in transcriptional regulation through its interaction with the transcriptional corepressor TPR1 (Topless-related 1). The TIR domains of all three proteins have successfully been expressed and purified as soluble proteins in Escherichia coli. Plate-like crystals of the RPS4 TIR domain were obtained using PEG 3350 as a precipitant; they diffracted X-rays to 2.05 angstrom resolution, had the symmetry of space group P1 and analysis of the Matthews coefficient suggested that there were four molecules per asymmetric unit. Tetragonal crystals of the RRS1 TIR domain were obtained using ammonium sulfate as a precipitant; they diffracted X-rays to 1.75 angstrom resolution, had the symmetry of space group P4(1)2(1)2 or P4(3)2(1)2 and were most likely to contain one molecule per asymmetric unit. Crystals of the SNC1 TIR domain were obtained using PEG 3350 as a precipitant; they diffracted X-rays to 2.20 angstrom resolution and had the symmetry of space group P4(1)2(1)2 or P4(3)2(1)2, with two molecules predicted per asymmetric unit. These results provide a good foundation to advance the molecular and structural understanding of the function of the TIR domain in plant innate immunity

Vocalisations of Killer Whales (Orcinus orca) in the Bremer Canyon, Western Australia

To date, there has been no dedicated study in Australian waters on the acoustics of killer whales. Hence no information has been published on the sounds produced by killer whales from this region. Here we present the first acoustical analysis of recordings collected off the Western Australian coast. Underwater sounds produced by Australian killer whales were recorded during the months of February and March 2014 and 2015 in the Bremer Canyon in Western Australia. Vocalisations recorded included echolocation clicks, burst-pulse sounds and whistles. A total of 28 hours and 29 minutes were recorded and analysed, with 2376 killer whale calls (whistles and burst-pulse sounds) detected. Recordings of poor quality or signal-to-noise ratio were excluded from analysis, resulting in 142 whistles and burst-pulse vocalisations suitable for analysis and categorisation. These were grouped based on their spectrographic features into nine Bremer Canyon (BC) "call types". The frequency of the fundamental contours of all call types ranged from 600 Hz to 29 kHz. Calls ranged from 0.05 to 11.3 seconds in duration. Biosonar clicks were also recorded, but not studied further. Surface behaviours noted during acoustic recordings were categorised as either travelling or social behaviour. A detailed description of the acoustic characteristics is necessary for species acoustic identification and for the development of passive acoustic tools for population monitoring, including assessments of population status, habitat usage, migration patterns, behaviour and acoustic ecology. This study provides the first quantitative assessment and report on the acoustic features of killer whales vocalisations in Australian waters, and presents an opportunity to further investigate this little-known population

A Natural Combination Extract of Viscum album L. Containing Both Triterpene Acids and Lectins Is Highly Effective against AML In Vivo

Aqueous Viscum album L. extracts are widely used in complementary cancer medicine. Hydrophobic triterpene acids also possess anti-cancer properties, but due to their low solubility they do not occur in significant amounts in aqueous extracts. Using cyclodextrins we solubilised mistletoe triterpenes (mainly oleanolic acid) and investigated the effect of a mistletoe whole plant extract on human acute myeloid leukaemia cells in vitro, ex vivo and in vivo. Single Viscum album L. extracts containing only solubilised triterpene acids (TT) or lectins (viscum) inhibited cell proliferation and induced apoptosis in a dose-dependent manner in vitro and ex vivo. The combination of viscum and TT extracts (viscumTT) enhanced the induction of apoptosis synergistically. The experiments demonstrated that all three extracts are able to induce apoptosis via caspase-8 and -9 dependent pathways with down-regulation of members of the inhibitor of apoptosis and Bcl-2 families of proteins. Finally, the acute myeloid leukaemia mouse model experiment confirmed the therapeutic effectiveness of viscumTT-treatment resulting in significant tumour weight reduction, comparable to the effect in cytarabine-treated mice. These results suggest that the combination viscumTT may have a potential therapeutic value for the treatment AML

SME Internationalization beyond Exporting: A Knowledge-based Perspective across Managers and Advisers

Micromultinationals are small and medium-sized enterprises that engage in foreign market entry modes beyond exporting. The purpose of this study is to unveil the knowledge types required by micromultinationals. To this end, we conducted an interpretive interview study involving managers and advisers. We extend the SME internationalization literature by distilling the knowledge types that this unique body of small multinationals requires. Furthermore, we generate a framework that enhances the knowledge-based perspective by showing that micromultinational expansion is led by tacitly dominated knowledge of internal actors related to products, industries, and markets and facilitated by functional knowledge provided by external actors