Energy efficient engine sector combustor rig test program

Under the NASA-sponsored Energy Efficient Engine program, Pratt & Whitney Aircraft has successfully completed a comprehensive combustor rig test using a 90-degree sector of an advanced two-stage combustor with a segmented liner. Initial testing utilized a combustor with a conventional louvered liner and demonstrated that the Energy Efficient Engine two-stage combustor configuration is a viable system for controlling exhaust emissions, with the capability to meet all aerothermal performance goals. Goals for both carbon monoxide and unburned hydrocarbons were surpassed and the goal for oxides of nitrogen was closely approached. In another series of tests, an advanced segmented liner configuration with a unique counter-parallel FINWALL cooling system was evaluated at engine sea level takeoff pressure and temperature levels. These tests verified the structural integrity of this liner design. Overall, the results from the program have provided a high level of confidence to proceed with the scheduled Combustor Component Rig Test Program

Laser-Induced, Polarization Dependent Shape Transformation of Au/Ag Nanoparticles in Glass

Bimetallic, initially spherical Ag/Au nanoparticles in glass prepared by ion implantation have been irradiated with intense femtosecond laser pulses at intensities still below the damage threshold of the material surface. This high-intensity laser processing produces dichroism in the irradiated region, which can be assigned to the observed anisotropic nanoparticle shapes with preferential orientation of the longer particle axis along the direction of laser polarization. In addition, the particle sizes have considerably been increased upon processing

Tętniczy przepływ krwi w płucach i OUN płodu w ciąży o przebiegu prawidłowym i w ciąży wysokiego ryzyka

Studies on fetal lung/brain circulation by means of power Doppler technique have suggested a marked reduction in lung perfusion in high-risk pregnancies as a sign of circulation redistribution. The ratio between lung/brain perfusion might therefore give a new method to predict fetal circulation centralization. Objective: The aim of the present study was to obtain fetal lung and cerebral artery ratio in normal and high-risk pregnancies. Study design: Doppler samples from proximal right pulmonary artery blood velocities and middle cerebral artery (MCA) were recorded cross-sectionally in 228 normal singleton pregnancies at gestational age 22 to 40 weeks. MCA / right pulmonary artery pulsatility index (PI) ratio was calculated. Doppler samples from proximal right pulmonary artery and MCA were also recorded in 89 high-risk singleton pregnancies and the results related to perinatal outcome. Results: In the normal controls, right pulmonary artery PI remained stable until 30 weeks of gestation with slight increase thereafter until term. The MCA to right pulmonary artery PI ratio increased between 22 and 28 weeks of gestation with the rapid fall towards term. In the high-risk pregnancies group, right pulmonary artery PI showed no significant correlation to perinatal outcome, but signs of brain-sparing in the MCA were correlated to all adverse outcome parameters. Conclusion: Velocimetry of the middle cerebral artery is better than velocimetry of right pulmonary artery in predicting adverse outcome of pregnancy. The brain/lung PI ratio does not improve the prediction of adverse outcome of pregnancy.Wstęp: Ocena przepływu krwi przy pomocy metod dopplerowskich w krążeniu płucnym I mózgowym sugerowała istotny spadek perfuzji płuc w ciążach wysokiego ryzyka jako wykładnik zmienionej redystrybucji krwi w ustroju płodu. Stworzyło to koncepcję z której wynika, że stosunek perfuzji krwi w płucach i mózgu może być nową metodą oceniającą centralizację krążenia. Cel pracy: Celem badań było określenie współczynnika określającego stosunek przepływów krwi w płucach i mózgu w ciąży o przebiegu prawidłowym i w ciąży wysokiego ryzyka. Materiał i metody: Przepływ krwi oceniano metodą dopplerowska w proksymalnej części prawej tętnicy płucnej oraz w tętnicy środkowej mózgu w dwóch grupach pacjentek: u 228 ciężarnych z ciążą pojedynczą o przebiegu prawidłowym między 22 a 40 tygodniem ciąży oraz u 89 ciężarnych z ciążą wysokiego ryzyka. W oparciu o uzyskane wyniki obliczano stosunek wartości PI w naczyniach płucnych i mózgowych. Uzyskane wyniki odnoszono do stanu noworodka po porodzie. Wyniki: W grupie kontrolnej wartości PI tętnicy płucnej są stabilne aż do 30. tygodnia ciąży z następowym nieznacznym wzrostem aż do terminu porodu. Wartości stosunku PI w tętnicy środkowej mózgu do PI prawej tętnicy płucnej wzrastają między 22. a 28. tygodniem ciąży z następowym spadkiem do terminu porodu. W grupie ciąż wysokiego ryzyka, nie stwierdzono istotnej zależności między wartościami PI prawej tętnicy płucnej a stanem noworodka po porodzie. W tej grupie ciąż wykładniki centralizacji krążenia wykazywały zależność w odniesieniu do parametrów charakteryzujących zły stan noworodka po porodzie. Wnioski: Ocena przepływu krwi w tętnicy środkowej mózgu, w porównaniu z oceną przepływu w tętnicy płucnej, ma większą wartość predykcyjną w prognozowaniu stanu płodu. Analiza współczynnika – PI mózgu/PI płuc – nie poprawia tej oceny

Sigma-phase in Fe-Cr and Fe-V alloy systems and its physical properties

A review is presented on physical properties of the sigma-phase in Fe-Cr and Fe-V alloy systems as revealed both with experimental -- mostly with the Mossbauer spectroscopy -- and theoretical methods. In particular, the following questions relevant to the issue have been addressed: identification of sigma and determination of its structural properties, kinetics of alpha-to-sigma and sigma-to-alpha phase transformations, Debye temperature and Fe-partial phonon density of states, Curie temperature and magnetization, hyperfine fields, isomer shifts and electric field gradients.Comment: 26 pages, 23 figures and 83 reference

The antecedents and consequences of affordable value innovations for emerging markets

Emerging markets offer tremendous growth opportunities for firms. While established multinational firms typically focus on premium segments in emerging markets, they often fail to leverage additional growth opportunities in so-called good enough or low-income segments in emerging markets. Customers in these low-income markets have substantially different requirements and are very price sensitive. Theoretical and case-based research suggests that innovating for these low-income segments in emerging markets differs significantly from innovating for premium or traditional Western markets. We argue that tapping successfully into low-income segments in emerging markets requires the development of new products that meet the low price expectations while at the same time offering also value to customers in these segments. We refer to these new products as affordable value innovations. We analyze the antecedents of affordable value innovation for emerging markets. We draw on institutional theory to derive three potentially relevant antecedents of affordable value innovation for emerging markets. These are bricolage, local embeddedness, and standardization. We test our hypotheses using multiple informant data from 47 multinational corporations involving 103 innovation projects that target low-income customers in emerging markets. Our empirical analysis shows that all three antecedents have significant effects on the level of affordable value innovation: while bricolage and local embeddedness are positively related to the level of affordable value innovation, standardization has a negative impact. We also examine the relationship between the level of affordable value innovation and performance. We find evidence for our basic assumption that a firm's capability to develop and launch affordable value innovations is key to success in emerging markets. It indicates that a firm's investments in affordable value innovations for emerging markets pay off financially. Finally, a cross-regional comparison of our data shows that the key findings on antecedents of affordable value innovation and its impact on performance do not vary across various emerging markets. Overall, our findings offer important implications for research on and the practice of innovation for low-income segments in emerging markets

Idarucizumab for Dabigatran Reversal - Full Cohort Analysis.

BACKGROUND: Idarucizumab, a monoclonal antibody fragment, was developed to reverse the anticoagulant effect of dabigatran. METHODS: We performed a multicenter, prospective, open-label study to determine whether 5 g of intravenous idarucizumab would be able to reverse the anticoagulant effect of dabigatran in patients who had uncontrolled bleeding (group A) or were about to undergo an urgent procedure (group B). The primary end point was the maximum percentage reversal of the anticoagulant effect of dabigatran within 4 hours after the administration of idarucizumab, on the basis of the diluted thrombin time or ecarin clotting time. Secondary end points included the restoration of hemostasis and safety measures. RESULTS: A total of 503 patients were enrolled: 301 in group A, and 202 in group B. The median maximum percentage reversal of dabigatran was 100% (95% confidence interval, 100 to 100), on the basis of either the diluted thrombin time or the ecarin clotting time. In group A, 137 patients (45.5%) presented with gastrointestinal bleeding and 98 (32.6%) presented with intracranial hemorrhage; among the patients who could be assessed, the median time to the cessation of bleeding was 2.5 hours. In group B, the median time to the initiation of the intended procedure was 1.6 hours; periprocedural hemostasis was assessed as normal in 93.4% of the patients, mildly abnormal in 5.1%, and moderately abnormal in 1.5%. At 90 days, thrombotic events had occurred in 6.3% of the patients in group A and in 7.4% in group B, and the mortality rate was 18.8% and 18.9%, respectively. There were no serious adverse safety signals. CONCLUSIONS: In emergency situations, idarucizumab rapidly, durably, and safely reversed the anticoagulant effect of dabigatran. (Funded by Boehringer Ingelheim; RE-VERSE AD ClinicalTrials.gov number, NCT02104947 .)

Irradiation-induced Ag nanocluster nucleation in silicate glasses: analogy with photography

The synthesis of Ag nanoclusters in sodalime silicate glasses and silica was studied by optical absorption (OA) and electron spin resonance (ESR) experiments under both low (gamma-ray) and high (MeV ion) deposited energy density irradiation conditions. Both types of irradiation create electrons and holes whose density and thermal evolution - notably via their interaction with defects - are shown to determine the clustering and growth rates of Ag nanocrystals. We thus establish the influence of redox interactions of defects and silver (poly)ions. The mechanisms are similar to the latent image formation in photography: irradiation-induced photoelectrons are trapped within the glass matrix, notably on dissolved noble metal ions and defects, which are thus neutralized (reverse oxidation reactions are also shown to exist). Annealing promotes metal atom diffusion, which in turn leads to cluster nuclei formation. The cluster density depends not only on the irradiation fluence, but also - and primarily - on the density of deposited energy and the redox properties of the glass. Ion irradiation (i.e., large deposited energy density) is far more effective in cluster formation, despite its lower neutralization efficiency (from Ag+ to Ag0) as compared to gamma photon irradiation.Comment: 48 pages, 18 figures, revised version publ. in Phys. Rev. B, pdf fil

Chorioangioma – opis przypadku

Chorioangioma (chorionic angioma) is the most common non-malignant placental tumor. Taking into account its morphological structure, it can have significant influence on fetal condition and pregnancy, depending on its size. In the presented case a substantial placental tumor was diagnosed and complications typical for chorioangioma, such as fetal hemodynamic disorders, polyhydramnios, gestational diabetes and premature labor, were observed. The applied treatment led to normalization of the fetal and maternal condition and to prolongation of the pregnancy.Chorioangioma (naczyniak kosmówki) jest najczęściej występującym niezłośliwym guzem łożyska. Z uwagi na swoją budowę morfologiczną w zależności od rozmiaru może mieć istotny wpływ na stan płodu oraz przebieg ciąży. W przedstawionym przypadku zdiagnozowano duży guz łożyska i zaobserwowano powikłania typowe dla chorioangioma takie jak zaburzenia hemodynamiczne krążenia płodowego, wielowodzie, cukrzycę ciążową i poród przedwczesny. Zastosowane leczenie pozwoliło na normalizacje stanu płodu i matki oraz wydłużenie czasu trwania ciąży

Determination of crystal orientation by Ω-scan method in nickel-based single-crystal turbine blades

The article presents an assessment of the crystal perfection of single-crystal turbine blades based on the crystal orientation and lattice parameter distribution on their surface. Crystal orientation analysis was conducted by the X-ray diffraction method Ω-scan and the X-ray diffractometer provided by the EFG Company. The Ω-scan method was successfully used for evaluation of the crystal orientation and lattice parameters in semiconductors. A description of the Ω-scan method and an example of measurement of crystal orientation compared to the Laue and EBSD methods are presented.This work was supported by the National Science Centre Poland (NCN) under Grant No. Preludium-UMO-2016/21/N/ST8/00240