776 research outputs found
The Role of Physical, Human and Social Capital in Regional Financial Development Differences: An Analysis of Turkish Provinces
The Role of Physical, Human and Social Capital in Regional Financial Development Differences: An Analysis of Turkish Provinces Ercan Dulgeroglu , Sibel Bali Eryigit , Kadir Y. Eryigit and Filiz Gaygusuz Abstract With the undeniable importance of the financial markets in the economy, the factors stimulating financial development have started to be researched, particularly in recent times in a more intensive way. Starting from this point, the driving force of this study is both to contribute to international literature in this field and to fill a gap in the literature related to Turkey. The main purpose of this study is to explain the causes of regional financial development differences on the basis of capital accumulation. In order to answer the question âWhat is the effect and degree of importance of physical, human and social capital on the differences in regional financial development?â, in this study some indexes for financial development and each type of capital accumulation will be calculated using kernel principle components analysis and depending on the annual data of 81 provinces covering the period 2005 â 2009. As an index, the capital measurements can be seen in a comprehensive form allowing for more accurate measurement and evaluation of both the capital accumulation and financial development. By using the calculated indexes, then, financial development differences are evaluated with spatial panel data methods developed by Elhorst (2003). In this context, to our knowledge, this study is the first to take into account the effects of each type of capital on financial development in a model simultaneously. Keywords: Financial development, physical capital, human capital, social capital, spatial panel data analysis,
A Real-Time Machine Learning Module for Motion Artifact Detection in fNIRS
Functional Near-Infrared Spectroscopy (fNIRS) is a neuroimaging method which can be implemented with a wearable form factor. However, the data of fNIRS can be affected by motion artifact, which is conventionally processed offline using MATLAB-based software package via a bulky PC. This study trains a Support Vector Machine (SVM) algorithm and proposes a hardware design approach based on an FPGA to achieve the first real-time fNIRS motion artifact detection. The SVM hardware architecture proposed here utilizes a partially sequential-partially parallel implementation of the classification algorithm where Support Vector channels are consolidated into a single oversampled channel. A high classification accuracy of 97.42%, low FPGA resource utilization of 38,354 look-up tables and 6024 flip-flops with 10.92 us latency is achieved, outperforming conventional CPU SVM methods. These results show that an FPGA-based fNIRS motion artifact detector can be exploited whilst meeting real-time and resource constraints that are crucial in high-performance reconfigurable hardware systems
Path integral simulation of exchange interactions in CMOS spin qubits
The boom of semiconductor quantum computing platforms created a demand for
computer-aided design and fabrication of quantum devices. Path integral Monte
Carlo (PIMC) can have an important role in this effort because it intrinsically
integrates strong quantum correlations that often appear in these
multi-electron systems. In this paper we present a PIMC algorithm that
estimates exchange interactions of three-dimensional electrically defined
quantum dots. We apply this model to silicon metal-oxide-semiconductor (MOS)
devices and we benchmark our method against well-tested full configuration
interaction (FCI) simulations. As an application, we study the impact of a
single charge trap on two exchanging dots, opening the possibility of using
this code to test the tolerance to disorder of CMOS devices. This algorithm
provides an accurate description of this system, setting up an initial step to
integrate PIMC algorithms into development of semiconductor quantum computers.Comment: 10 pages , 5 figure
Exploring the Limits of Dative Boratrane Bonding: Iron as a Strong Lewis Base in Low-Valent Non-Heme Iron-Nitrosyl Complexes
We previously reported the synthesis and preliminary characterization of a unique series of low-spin (ls) {FeNO}âžâ»Âčâ° complexes supported by an ambiphilic trisphosphineborane ligand, [Fe(TPB)(NO)]^(+/0/â). Herein, we use advanced spectroscopic techniques and density functional theory (DFT) calculations to extract detailed information as to how the bonding changes across the redox series. We find that, in spite of the highly reduced nature of these complexes, they feature an NO+ ligand throughout with strong FeâNO Ï-backbonding and essentially closed-shell electronic structures of their FeNO units. This is enabled by an FeâB interaction that is present throughout the series. In particular, the most reduced [Fe(TPB)(NO)]â complex, an example of a ls-{FeNO}Âčâ° species, features a true reverse dative Fe â B bond where the Fe center acts as a strong Lewis-base. Hence, this complex is in fact electronically similar to the ls-{FeNO}âž system, with two additional electrons âstoredâ on site in an FeâB single bond. The outlier in this series is the ls-{FeNO}âč complex, due to spin polarization (quantified by pulse EPR spectroscopy), which weakens the FeâNO bond. These data are further contextualized by comparison with a related Nâ complex, [Fe(TPB)(Nâ)]â», which is a key intermediate in Fe(TPB)-catalyzed Nâ fixation. Our present study finds that the Fe â B interaction is key for storing the electrons needed to achieve a highly reduced state in these systems, and highlights the pitfalls associated with using geometric parameters to try to evaluate reverse dative interactions, a finding with broader implications to the study of transition metal complexes with boratrane and related ligands
Nuclear Inelastic X-Ray Scattering of FeO to 48 GPa
The partial density of vibrational states has been measured for Fe in
compressed FeO (w\"ustite) using nuclear resonant inelastic x-ray scattering.
Substantial changes have been observed in the overall shape of the density of
states close to the magnetic transiton around 20 GPa from the paramagnetic (low
pressure) to the antiferromagnetic (high pressure) state. Our data indicate a
substantial softening of the aggregate sound velocities far below the
transition, starting between 5 and 10 GPa. This is consistent with recent
radial x-ray diffraction measurements of the elastic constants in FeO. The
results indicate that strong magnetoelastic coupling in FeO is the driving
force behind the changes in the phonon spectrum of FeO.Comment: 4 pages, 4 figure
Impact of lattice dynamics on the phase stability of metamagnetic FeRh: Bulk and thin films
We present phonon dispersions, element-resolved vibrational density of states
(VDOS) and corresponding thermodynamic properties obtained by a combination of
density functional theory (DFT) and nuclear resonant inelastic X-ray scattering
(NRIXS) across the metamagnetic transition of B2 FeRh in the bulk material and
thin epitaxial films. We see distinct differences in the VDOS of the
antiferromagnetic (AF) and ferromagnetic (FM) phase which provide a microscopic
proof of strong spin-phonon coupling in FeRh. The FM VDOS exhibits a particular
sensitivity to the slight tetragonal distortions present in epitaxial films,
which is not encountered in the AF phase. This results in a notable change in
lattice entropy, which is important for the comparison between thin film and
bulk results. Our calculations confirm the recently reported lattice
instability in the AF phase. The imaginary frequencies at the -point depend
critically on the Fe magnetic moment and atomic volume. Analyzing these non
vibrational modes leads to the discovery of a stable monoclinic ground state
structure which is robustly predicted from DFT but not verified in our thin
film experiments. Specific heat, entropy and free energy calculated within the
quasiharmonic approximation suggest that the new phase is possibly suppressed
because of its relatively smaller lattice entropy. In the bulk phase, lattice
degrees of freedom contribute with the same sign and in similar magnitude to
the isostructural AF-FM phase transition as the electronic and magnetic
subsystems and therefore needs to be included in thermodynamic modeling.Comment: 15 pages, 12 figure
Exploring the Limits of Dative Boratrane Bonding: Iron as a Strong Lewis Base in Low-Valent Non-Heme Iron-Nitrosyl Complexes
We previously reported the synthesis and preliminary characterization of a unique series of low-spin (ls) {FeNO}âžâ»Âčâ° complexes supported by an ambiphilic trisphosphineborane ligand, [Fe(TPB)(NO)]^(+/0/â). Herein, we use advanced spectroscopic techniques and density functional theory (DFT) calculations to extract detailed information as to how the bonding changes across the redox series. We find that, in spite of the highly reduced nature of these complexes, they feature an NO+ ligand throughout with strong FeâNO Ï-backbonding and essentially closed-shell electronic structures of their FeNO units. This is enabled by an FeâB interaction that is present throughout the series. In particular, the most reduced [Fe(TPB)(NO)]â complex, an example of a ls-{FeNO}Âčâ° species, features a true reverse dative Fe â B bond where the Fe center acts as a strong Lewis-base. Hence, this complex is in fact electronically similar to the ls-{FeNO}âž system, with two additional electrons âstoredâ on site in an FeâB single bond. The outlier in this series is the ls-{FeNO}âč complex, due to spin polarization (quantified by pulse EPR spectroscopy), which weakens the FeâNO bond. These data are further contextualized by comparison with a related Nâ complex, [Fe(TPB)(Nâ)]â», which is a key intermediate in Fe(TPB)-catalyzed Nâ fixation. Our present study finds that the Fe â B interaction is key for storing the electrons needed to achieve a highly reduced state in these systems, and highlights the pitfalls associated with using geometric parameters to try to evaluate reverse dative interactions, a finding with broader implications to the study of transition metal complexes with boratrane and related ligands
Hidden carbon in Earthâs inner core revealed by shear softening in dense FeâCâ
Earthâs inner core is known to consist of crystalline iron alloyed with a small amount of nickel and lighter elements, but the shear wave (S wave) travels through the inner core at about half the speed expected for most iron-rich alloys under relevant pressures. The anomalously low S-wave velocity (v_S) has been attributed to the presence of liquid, hence questioning the solidity of the inner core. Here we report new experimental data up to core pressures on iron carbide Fe_7C_3, a candidate component of the inner core, showing that its sound velocities dropped significantly near the end of a pressure-induced spin-pairing transition, which took place gradually between 10 GPa and 53 GPa. Following the transition, the sound velocities increased with density at an exceptionally low rate. Extrapolating the data to the inner core pressure and accounting for the temperature effect, we found that low-spin Fe_7C_3 can reproduce the observed v_S of the inner core, thus eliminating the need to invoke partial melting or a postulated large temperature effect. The model of a carbon-rich inner core may be consistent with existing constraints on the Earth's carbon budget and would imply that as much as two thirds of the planet's carbon is hidden in its center sphere
Measuring velocity of sound with nuclear resonant inelastic x-ray scattering
Nuclear resonant inelastic x-ray scattering is used to measure the projected
partial phonon density of states of materials. A relationship is derived
between the low-energy part of this frequency distribution function and the
sound velocity of materials. Our derivation is valid for harmonic solids with
Debye-like low-frequency dynamics. This method of sound velocity determination
is applied to elemental, composite, and impurity samples which are
representative of a wide variety of both crystalline and noncrystalline
materials. Advantages and limitations of this method are elucidated
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