Behavior of Electrodeposited Cd and Pb Schottky Junctions on CH3-Terminated n-Si(111) Surfaces

n-Si/Cd and n-Si/Pb Schottky junctions have been prepared by electrodeposition of Cd or Pb from acidic aqueous solutions onto H-terminated and CH3-terminated n-type Si(111) surfaces. For both nondegenerately (n-) and degenerately (n+-) doped H–Si(111) electrodes, Cd and Pb were readily electroplated and oxidatively stripped, consistent with a small barrier height (Phib) at the Si/solution and the Si/metal junctions. Electrodeposition of Cd or Pb onto degenerately doped CH3-terminated n+-Si(111) electrodes occurred at the same potentials as Cd or Pd electrodeposition onto H-terminated n+-Si(111). However, electrodeposition on nondegenerately doped CH3-terminated n-Si(111) surfaces was significantly shifted to more negative applied potentials (by −130 and −347 mV, respectively), and the anodic stripping of the electrodeposited metals was severely attenuated, indicating large values of Phib for contacts on nondegenerately doped n-type CH3–Si(111) surfaces. With either Cd or Pb, current–voltage measurements on the dry, electrodeposited Schottky junctions indicated that much larger values of Phib were obtained on CH3-terminated n-Si(111) surfaces than on H-terminated n-Si(111) surfaces. Chronoamperometric data indicated that CH3–Si(111) surfaces possessed an order-of-magnitude lower density of nucleation sites for metal electrodeposition than did H–Si(111) surfaces, attesting to the high degree of structural passivation afforded by the CH3–Si surface modification

Supercurrent on a vortex core in 2H-NbSe2_2: current driven scanning tunneling spectroscopy

We report current driven scanning tunneling spectroscopy (CDSTS) measurements at very low temperatures on vortices in 2H-NbSe2. We find that a current produces an increase of the density of states at the Fermi level in between vortices, and a reduction of the zero bias peak at the vortex center. This occurs well below the de-pairing current. We conclude that a supercurrent affects the low energy part of the superconducting gap structure of 2H-NbSe2.Comment: 5 pages, 5 figure

Traveling wave solutions for wave equations with two exponential nonlinearities

We use a simple method that leads to the integrals involved in obtaining the traveling wave solutions of wave equations with one and two exponential nonlinearities. When the constant term in the integrand is zero, implicit solutions in terms of hypergeometric functions are obtained while when that term is nonzero all the basic traveling wave solutions of Liouville, Tzitzeica and their variants, as well as sine/sinh-Gordon equations with important applications in the phenomenology of nonlinear physics and dynamical systems are found through a detailed study of the corresponding elliptic equationsComment: 9 pages, 7 figures, 42 references, version matching the published articl

The Effects of Developed Country Equity Markets on Developing Country Trading Partner Growth

This dissertation consists of three chapters, focusing on the effects that developed countries have on their developing country trading partners with the consideration of macroeconomic variables. In Chapter I, I explore the differences in the drivers and the corresponding magnitude effects on domestic real stock returns during fixed and floating exchange rate regimes. In Chapter II, the equity developed market effects on domestic real stock returns is determined during the pre- and post-great recession periods under floating exchange rate regimes. Chapter III summarizes the findings and provides concluding remarks regarding the benefits and disadvantages in adopting a floating exchange rate regime and the effects of monetary policy on developing countries during pre- and post-great recession periods during floating exchange rate regimes. In Chapter I, through the use of a basic VAR, impulse response functions, and variance decompositions on developing country real stock returns, I find that external developed country equity markets strongly influence the domestic returns as the primary indicator during both fixed and floating exchange rate regimes, while trade is irrelevant. More importantly, the developing country annual stock returns during floating regimes prove to be greater than that for the fixed regimes. Even though domestic equity market volatility is greater during the floating exchange rate period, it is not considerable enough to merit a developing countries’ reluctance to adopt a floating exchange rate regime. These results favor the attraction for developing countries to adopt a floating exchange rate regime, a move toward a market-oriented economy, contrary to some researchers. Monetary policy as outlined by the Mundell-Fleming Theory is ineffective for developing countries during their floating exchange rate regime periods. Extended research regarding the degree of influence of the theoretical assumptions is suggested. In Chapter II, I examine the differences in the primary indicators and magnitudes of influence in explaining changes in domestic developing country real stock returns during the pre- and post-great recession periods, herein referred to as pre- and post-crisis periods. The study is conducted during floating exchange rate regimes, allowing countries an equal benefit in adjusting monetary policy as an economic stabilization tool. The primary driver during both the pre- and post-crisis periods is the external and exogenous developed country equity market with a strong influence of 24.72 and 26.33 percent, for the pre- and post-crisis periods, respectively. These findings support the premise that financial channels and not trading channels are more important in crisis recovery. The developed countries show to have rebounded from the recession, with annual returns of 9.94 percent and 10.80 percent for the pre-crisis and post-crisis periods, respectively. During the pre-crisis period, the developing countries experienced annual returns of 68.52 percent, but have yet to fully rebound with a post-crisis mean annual return of 8.16 percent. As expected, the developed countries have rebounded quicker than the developing countries, suggesting an asymmetric affect based on country development with the developing countries absorbing a much greater initial adverse effect on returns. Post-crisis, the developed and developing country equity markets are experiencing a positive 1.61 and 1.54 slope trend on returns, respectively, representing a common or near common recovery rate. During the post-recession period, the annual stock returns, for the developed and developing countries are 10.80 percent and 11.84 percent, respectively. Thereby confirming the common, or near common recovery rate. In Chapter III, I summarize the dissertation findings and provide concluding remarks on research expansion. Emerging countries continue to grow and increase in their contribution to the world economy. With the tendency of developing countries moving toward increased exchange rate flexibility, they are automatically drawn into the integrated world economy in terms of trade of good and services, and financial transactions. I provide evidence that the benefits associated with a floating exchange rate regime for a developing country is greater than maintaining a fixed exchange rate regime. These findings benefit both researchers and investors in their decision-making process. I provide evidence that the benefits associated with an adoption of a floating exchange rate regime provide an incremental increase in economic control through monetary policy. These findings benefit both researchers and investors in their decision-making process as developing countries continue to move toward an equity market-based economy and positively effecting the global economy

Inspiration Mining: Intersecting Improbable Connections in a New Landscape of Cultural Reflection and Influence

This article aims to present a critical reflection on the collaborative curatorship of the exhibition “Intersecting Improbable Connections”. It is a transdisciplinary exhibition covering architecture, design, arts, among other fields, and calls for non-linear productive thinking strategies. It explores the intersection of unlikely relationships to inspire memorable visits to museums, and it feeds the Inspædia platform, creating a new landscape of reflection and cultural influence. It advocates a new concept of exhibition curation that minimizes costs (because it does not involve transportation or insurance for the pieces) and is intended to help stimulate creative processes. Based on a selection of content from the participating museums’ permanent exhibitions, duly marked with QR Codes, visitors can access that content that is already available on the Inspædia platform and explore potentially endless connections, without losing contact with the physical object (and vice versa).FCT – Fundação para a Ciência e a Tecnologia, in the scope of the projects SFRH/BPD/98427/2013, UID/EAT/04008/ 2019, and UID/AUR/04026/201

SBE-type metal-substituted aluminophosphates: detemplation and coordination chemistry

The detemplation process in Me-SBE (Me = Co^2+, Mg^2+, and Mn^2+) aluminophosphates was studied to elucidate materials stability and framework characteristics. In addition, the hydrothermal synthesis conditions were optimized to obtain materials with minimal phase impurities. This was accomplished by means of decreasing reaction temperature and increasing aging periods. Scanning electron microscopy analysis of the Mg- and Mn-SBE as-synthesized samples revealed square plates with truncated corner morphologies grown in aggregated fashion and contrasting with the previously reported hexagonal platelike morphology of Co-SBE. Cautious detemplation in vacuum, using an evacuation rate of 10 mmHg/s and a temperature of 648 K, resulted in surface areas of about 700, 500, and 130 m^2/g for Mg-, Co-, and Mn-SBE, respectively. Thermal gravimetric analysis and in situ high-temperature powder X-ray diffraction analyses indicate the frameworks for all of the SBE variants experienced collapse upon treatment with helium at temperatures above 700 K and subsequently formed an aluminophosphate trydimite dense phase. Detemplation in air at all times resulted in framework destruction during detemplation. In situ differential scanning calorimetry−powder X-ray diffraction data showed that the SBE frameworks experience breathing modes related to specific endothermic and exothermic scenarios during air treatment. Decomposition and elimination of the organic template during vacuum treatment was verified by Fourier transform infrared spectroscopy. X-ray photoelectron spectroscopy revealed that most of the Co atoms in vacuum-treated samples are in tetrahedral coordination, while the Mn atoms exhibit various coordination states. Ultraviolet-visible, electron paramagnetic resonance, and magic-angle spinning nuclear magnetic resonance (MAS NMR) spectroscopy corroborated the latter result in addition to providing evidence for the formation of Mn extra framework species. ^(27)Al MAS NMR spectra for vacuum-detemplated Mg-SBE samples prior to and after dehydration confirmed the reversible formation of aluminum octahedral sites. This, however, did not affect the porous nature of detemplated Mg-SBE samples as these are capable of adsorbing 19 water molecules per super cage at 298 K