Phosphorus poisoning during wet oxidation of methane over Pd@CeO2/graphite model catalysts

10siThe influence of phosphorus and water on methane catalytic combustion was studied over Pd@CeO2 model catalysts supported on graphite, designed to be suitable for X-ray Photoelectron Spectroscopy/Synchrotron Radiation Photoelectron Spectroscopy (XPS/SRPES) analysis. In the absence of P, the catalyst was active for the methane oxidation reaction, although introduction of 15% H2O to the reaction mixture did cause reversible deactivation. In the presence of P, both thermal and chemical aging treatments resulted in partial loss of activity due to morphological transformation of the catalyst, as revealed by Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM) analysis. At 600 °C the combined presence of PO43− and water vapor caused a rapid, irreversible deactivation of the catalyst. XPS/SRPES analysis, combined with operando X-ray Absorption Near Edge Structure (XANES) and AFM measurements, indicated that water induces severe aggregation of CeO2 nanoparticles, exposure of CePO4 on the outer layer of the aggregates and incorporation of the catalytic-active Pd nanoparticles into the bulk. This demonstrates a temperature-activated process for P-poisoning of oxidation catalysts in which water vapor plays a crucial role.partially_openembargoed_20171009Monai, Matteo; Montini, Tiziano; Melchionna, Michele; Duchoň, Tomáš; Kúš, Peter; Tsud, Nataliya; Prince, Kevin C.; Matolin, Vladimir; Gorte, Raymond J.; Fornasiero, PaoloMonai, Matteo; Montini, Tiziano; Melchionna, Michele; Duchoň, Tomáš; Kúš, Peter; Tsud, Nataliya; Prince, Kevin C.; Matolin, Vladimir; Gorte, Raymond J.; Fornasiero, Paol

Challenging the Science Curriculum Paradigm: TeachingPrimary Children Atomic-Molecular Theory

Solutions to global issues demand the involvement of scientists, yet concern exists about retention rates in science as students pass through school into University. Young children are curious about science, yet are considered incapable of grappling with abstract and microscopic concepts such as atoms, sub-atomic particles, molecules and DNA. School curricula for primary (elementary) aged children reflect this by their limitation to examining only what phenomena are without providing any explanatory frameworks for how or why they occur. This research challenges the assumption that atomic-molecular theory is too difficult for young children, examining new ways of introducing atomic theory to 9 year olds and seeks to verify their efficacy in producing genuine learning in the participants. Early results in three cases in different schools indicate these novel methods fostered further interest in science, allowed diverse children to engage and learn aspects of atomic theory, and satisfied the children’s desire for intellectual challenge. Learning exceeded expectations as demonstrated in the post-interview findings. Learning was also remarkably robust, as demonstrated in two schools eight weeks after the intervention, and in one school, one year after their first exposure to ideas about atoms, elements and molecules

Quadrupole collectivity in Ca 42 from low-energy Coulomb excitation with AGATA

A Coulomb-excitation experiment to study electromagnetic properties of Ca42 was performed using a 170-MeV calcium beam from the TANDEM XPU facility at INFN Laboratori Nazionali di Legnaro. γ rays from excited states in Ca42 were measured with the AGATA spectrometer. The magnitudes and relative signs of ten E2 matrix elements coupling six low-lying states in Ca42, including the diagonal E2 matrix elements of 21+ and 22+ states, were determined using the least-squares code gosia. The obtained set of reduced E2 matrix elements was analyzed using the quadrupole sum rule method and yielded overall quadrupole deformation for 01,2+ and 21,2+ states, as well as triaxiality for 01,2+ states, establishing the coexistence of a weakly deformed ground-state band and highly deformed slightly triaxial sideband in Ca42. The experimental results were compared with the state-of-the-art large-scale shell-model and beyond-mean-field calculations, which reproduce well the general picture of shape coexistence in Ca42

Superdeformed and Triaxial States in Ca 42

Shape parameters of a weakly deformed ground-state band and highly deformed slightly triaxial sideband in ^{42}Ca were determined from E2 matrix elements measured in the first low-energy Coulomb excitation experiment performed with AGATA. The picture of two coexisting structures is well reproduced by new state-of-the-art large-scale shell model and beyond-mean-field calculations. Experimental evidence for superdeformation of the band built on 0_{2}^{+} has been obtained and the role of triaxiality in the A∼40 mass region is discussed. Furthermore, the potential of Coulomb excitation as a tool to study superdeformation has been demonstrated for the first time

Stokların envanter değerlemesi ve denetimi

STOKLARIN ENVANTER DEĞERLEMESİ VE DENETİMİ Sürekli gelişen dünyada ekonomisi güçlü olan işletmeler dünyadaki gelişmelere ayak uydurup söz sahibi olurken, ekonomisi zayıf işletmeler zamanla eriyip gitmektedirler. İşletmelerin varlık yapısının durumu, onların ekonomileri hakkında en önemli bilgiyi vermektedir. İşletmelerin en önemli varlık kalemlerinden biri de stoklardır. Stokların optimum düzeylerinin belirlenmesi, nitelikleri, nerede tutuldukları vb. özellikleri, işletmeler için maliyet kalemleri olup neticede kar ya da zararlarını etkilemektedir. Bu nedenle işletmelerin stoklarını doğru şekilde yönetmeleri gerekmektedir. Günümüzde “Malzeme İhtiyaç Planlaması”, “Tam Zamanında Üretim” gibi stok kontrol yöntemlerinin gelişmesi, işletmelerin varlık yapısında stokların miktar ve tutar olarak azalmasına yol açmıştır. Stokların kontrol altında tutulması, stok denetimlerinin sık ve düzgün yapılması, işletmeler açısından yararlı olmaktadır. Stokların envanter ve değerleme işlemlerinin zamanında ve doğru yapılması, bu işlemlerin doğruluğuna ilişkin denetimlerin artarak devam etmesi gerekmektedir. ABSTRACT STOCKS INVENTORY VALUATION AND AUDITING In permanently developing world, the companies of which’s economy are strong, can keep up with the developments in the world and can have a voice in the economy, on the contrary, companies whish have a week economy, fade away within time. The condition of assest structure of companies, provides a lot of information about their economy. One of the most important items of company’s assest is the stocks. the cost items for companies like determination of the optimum level of stocks, their quality, their storing, can effect the company’s profit and loss. For this reason, the stocks have to be managed correctly. In today, the improvement of stock control methods like “Materials Requirement Planning” and “Just In Time”, caused a decrease in quantity and in numbers of stocks. Keeping the stocks under control, auditing frequently and properly is for the companies interes. Stock valuation and stock accounting operations have to be made at the appropriate times and have to be audited increasingly in time

The effect of nifedipine tocolysis on Doppler indices of the uterine and umbilical Arteries

Purpose: The aim of this study was to evaluate the effect of oral nifedipine on Doppler indices of the uterine artery (UtA) and umbilical artery (UA) before and 24 hours, 48 hours, and 1 week after tocolytic treatment. Methods: This was a prospective, self-controlled, cohort study of 65 pregnant women undergoing nifedipine tocolysis. Doppler assessment of the UtA and UA was performed before treatment and 24 hours, 48 hours, and 1 week after the initial 4 doses of 10 mg of oral nifedipine, administered at 20-minute intervals. The maintenance dosage was 20 mg of oral nifedipine administered every 6 hours for 48 hours, for a total dose of 80 mg/day. Results: There was a decrease in the 24-hour values of the UA pulsatility index, resistance index (RI), systolic-diastolic (S:D) ratio, right UtA pulsatility index, RI, S:D ratio, and left UtA RI and S:D ratio with nifedipine therapy in comparison with the values recorded prior to nifedipine therapy. However, these differences were not statistically significant. There were no statistically significant differences between the data recorded prior to nifedipine administration and those obtained at 48 hours and 1 week after treatment. Conclusions: Oral nifedipine is a safe tocolytic agent with no long-term effect on fetomaternal circulation in pregnant women at risk of preterm delivery. © 2014 Wiley Periodicals, Inc

Modeling of Buckling Restrained Braces (BRBs) using Full-Scale Experimental Data

Hysteretic performance of buckling restrained braces (BRBs) having various core materials, namely, steel and aluminum alloy and with various end connections are numerically investigated. As a computational tool, nonlinear finite element analyses (FEAs) are performed to better model the hysteretic behavior. For the simulation, various aspects such as 1) stress - strain relationship including the strain hardening effect 2) von Mises yield criterion 3) contact surface parameters between the core metal and surrounding high strength grout and 4) friction are defined. Experimental results from near-full scale cyclic tests on two steel core BRBs having steel casing as a restraining environment (named as BRB-SC4 and BRB-SC5) and an aluminum alloy core & aluminum alloy casing tube (named as BRB-AC3) are used in the analyses. All cyclically tested specimens have been designed according to AISC Seismic Provisions. Numerical results obtained from 3D models developed in ANSYS-Workbench give satisfactory response parameters when compared with the experimental ones (e.g., hysteretic curves, dissipated energies). Further, a convergence analysis regarding element numbers in the developed model is conducted for each BRB specimen. Finally, key issues that influence the hysteretic modeling of BRBs are identified.Scientific and Technological Research Council of Turkey (TUBITAK)Turkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [110M776]; Istanbul Technical University Research Projects Unit (ITU-BAP) [33459]The authors acknowledge the supports by the Scientific and Technological Research Council of Turkey (TUBITAK, Project No: 110M776) and the Istanbul Technical University Research Projects Unit (ITU-BAP, Project No: 33459)