1,107 research outputs found
The effects of post-deposition annealing conditions on structure and created defects in Zn0.90Co0.10O thin films deposited on Si(100) substrate
We analyze the effect of post-deposition annealing conditions on both the structure and the created defects in Zn0.90Co0.10O thin films deposited on the Si (100) substrates by RF magnetron sputtering technique using home-made targets. We
concentrated on understanding the homogeneity of substituted Co+2 ions and the
annealing effects on the amount of defects in the ZnO lattice. Orientations of thin films are found to be in the [0002] direction with a surface roughness changing from 67±2 nm to 25.8±0.6 nm by annealing. The Co+2 ion substitutions, changing from 7.5±0.3 % to 8.8±0.3 %, cause to form Zn–O–Co bonds instead of Zn–O–Zn and split the Co2p energy level to Co2p1/2 and Co2p3/2 with 15.67±0.06 eV energy difference. In addition, the defects in the lattice were revealed from the correlations between Zn–O–Co bonds and intensity of Raman peak at around 691 cm-1. Furthermore, the asymmetry changes of O1s peak positions in X-ray Photoelectron Spectra (XPS) were also found to be in accordance with the Raman results
Keratocystic Odontogenic Tumors: Predictive Factors of Recurrence by Ki-67 and AgNOR Labelling
Purpose: The purpose of the present study was to investigate the possible role of Ki-67 and argyrophilic nucleolar organizing regions (AgNOR) between the recurrent and nonrecurrent keratocystic odontogenic tumors (KCOTs). Another aim was to compare the correlation between these two markers
Nitroglycerin-induced migraine type headache: bilaterally visible temporal arteries
A 37-year-old man presented to the emergency department suffering from headache, nausea and vomiting, which had started 1Â h previously. He had been diagnosed with coronary artery disease and had been taking isosorbid-5-mononitrate, aspirin and metoprolol for 3 days. His vital signs and physical and detailed neurological examinations were normal except for a new onset of bilaterally visible, palpable and pulsatile temporal arteries. We discuss how nitrates can increase the cerebral and also temporal blood flow, which can rarely be seen with the naked eye, as was observed in this patient
Preferential Trade Agreements and Manufactured Goods Exports: Does It Matter Whom You PTA With?
This paper explores two questions. First, can Preferential Trade Agreements (PTAs) affect industrial development in developing countries? Second, does it matter for developing countries whom they sign the PTAs with? We find that the answer to both questions is yes. Using bilateral manufactured goods exports data from 28 developing countries during 1978-2005, we find that South-South PTAs have a significantly positive effect on manufactured goods exports. In contrast, no such effect is detected in the case of South-North PTAs. We confirmed the robustness of these findings to estimation methodology, sample selection, time period, zero trade flows, and multilateral trade resistance
Asymmetric Effects of Financial Development on South-South and South-North Trade: Panel Data Evidence from Emerging Markets
Using bilateral trade data in total and technology-and-skill-intensive manufactured goods for 28 developing countries that account for 82% of all developing country manufactures exports between 1978 and 2005, this paper explores the effects of financial development on the pattern of specialization in South-South and South-North trade. The empirical results using dynamic panel regressions and comprehensive sensitivity tests suggest that financial development in the South has an economically and statistically significant positive effect on the share of total and technology-and-skill-intensive manufactures exports in GDP, and total exports in South-South trade. In contrast, no such significant or robust effect of financial development is found in South-North trade. Overall, the positive effect of financial development is found to be asymmetric favoring South-South significantly more than South-North trade. In addition, financial development is found to be increasing technology-and-skill-intensive manufactured goods exports significantly more than total manufactured or merchandise goods exports
Preferential Trade Agreements and Manufactured Goods Exports: Does It Matter Whom You PTA With?
This paper explores two questions. First, can Preferential Trade Agreements (PTAs) affect industrial development in developing countries? Second, does it matter for developing countries whom they sign the PTAs with? We find that the answer to both questions is yes. Using bilateral manufactured goods exports data from 28 developing countries during 1978-2005, we find that South-South PTAs have a significantly positive effect on manufactured goods exports. In contrast, no such effect is detected in the case of South-North PTAs. We confirmed the robustness of these findings to estimation methodology, sample selection, time period, zero trade flows, and multilateral trade resistance
A combined anatomical variation of inferior epigastric vessels
During the routine anatomical dissection of a male cadaver, a variation was observed both in the inferior epigastric artery (IEA) and inferior epiastric vein (IEV). Although the origin of the IEA from the right femoral artery (FA) is common variation in this case, the right IEA originated from the RFA, 13 mm inferior to inguinal ligament. The artery didn’t course anterior to the femoral vein (FV) as described in the variations of this vessel; instead, coursed on the lateral side of the variant IEV. Additionally, in this cadaver, the single right IEV drained to RFV 8 mm inferior to inguinal ligament. Both the variant artery and vein passed posterior to spermatic cord and their course in the rectus sheath were normal in every aspect. Due to its clinical importance, this combined anatomical variation must be remembered by the surgeons
Magnetotransport study on AllnN/(GaN)/AIN/GaN heterostructures
Cataloged from PDF version of article.We report the effect of a thin GaN (2?nm) interlayer on the magnetotransport properties of AlInN/AlN/GaN-based heterostructures. Two samples were prepared (Sample A: AlInN/AlN/GaN and sample B: AlInN/GaN/AlN/GaN). Van der Pauw and Hall measurements were performed in the 1.9300?K temperature range. While the Hall mobilities were similar at room temperature (RT), sample B had nearly twice as large Hall mobility as sample A at the lowest temperature; 679 and 889?cm2/Vs at RT and 1460 and 3082?cm2/Vs at 1.9?K for samples A and B. At 1.910?K, the longitudinal magnetoresistance was measured up to 9?T, in turn revealing Shubnikovde Haas (SdH) oscillations. The carrier concentration, effective mass and quantum mobility of the two-dimensional electron gas (2DEG) were determined from SdH oscillations. At 1.9?K, the 2DEG concentration of sample B was nearly seven times larger than of sample A (1.67 x 10(13)/cm2 vs. 0.24 x 10(13)/cm2). On the contrary, the quantum mobility was changed adversely nearly three times (sample B 2500?cm2/Vs and sample A 970?cm2/Vs). The increase of the 2DEG concentration was attributed to the existence of the GaN interlayer, which has strengthened the spontaneous polarization difference between the AlInN and GaN layers of the heterostructure. Hence, the stronger electric field at the 2DEG region bent the conduction band profile downwards and consequently the quantum mobility decreased due to the increased interface roughness scattering
Fatigue analysis-based numerical design of stamping tools made of cast iron
This work concerns stress and fatigue analysis of stamping tools made of cast iron with an essentially pearlitic matrix and containing foundry defects. Our approach consists at first, in coupling the stamping numerical processing simulations and structure analysis in order to improve the tool stiffness geometry for minimizing the stress state and optimizing their fatigue lifetime. The method consists in simulating the stamping process by considering the tool as a perfect rigid body. The estimated contact pressure is then used as boundary condition for FEM structure loading analysis of the tool. The result of this analysis is compared with the critical stress limit depending on the automotive model. The acceptance of this test allows calculating the fatigue lifetime of the critical zone by using the S–N curve of corresponding load ratio. If the prescribed tool life requirements are not satisfied, then the critical region of the tool is redesigned and the whole simulation procedures are reactivated. This method is applied for a cast iron EN-GJS-600-3. The stress-failure (S–N) curves for this material is determined at room temperature under push pull loading with different load ratios R0σmin/σmax0−2, R0−1 and R00.1. The effects of the foundry defects are determined by SEM observations of crack initiation sites. Their presence in tested specimens is associated with a reduction of fatigue lifetime by a factor of 2. However, the effect of the load ratio is more important
Trade flows, exchange rate uncertainty and financial depth: evidence from 28 emerging countries
This paper investigates the effects of real exchange rate uncertainty on manufactures exports from 28 emerging economies, representing 82\% of all developing country manufactures exports, and explores the sources of heterogeneity in the uncertainty effects by controlling for the direction of trade (South-North or South-South), and the level of financial development of the exporting country. The empirical results show that for more than half of the countries the uncertainty effect is unidirectional, either South-South or South-North, and the median impact is negative. In addition, while we find that financial development augments trade, exchange rate shocks can negate this effect. Last but not the least, trade among developing economies improves export growth under exchange rate shocks
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