Saturation Region Research Articles

Understanding of carriers’ kinetic energy in steep-slope P+N+P+N+ feedback field effect transistor

A feedback field-effect transistor takes advantage of the charges accumulated in its potential well and the restriction of carrier flow by its internal potential barrier to achieve superior electrical properties such as a subthreshold swing, threshold voltage, transconductance, and on/off current ratio. However, the device must deal with the modulation of non-uniformity under forward/reverse bias and with completely losing carrier flow control during reverse bias below a certain channel length. In this work, we address these significant issues by focusing on the width of the source/drain and demonstrate the operation of positive feedback in n-type metal oxide semiconductor field-effect transistor (nMOSFET) using only one additional step, resulting in a superior subthreshold swing (∼3 mV/decade at 300 K), a low threshold voltage (∼0.26 V), hysteresis window (0.018 V), and clear saturation region.

Electrophysical properties of multiferroic PMN-PT-Ferrite composites sintered by spark plasma sintering

This study elaborates on the technology of multiferroic ceramic composites sintered by the spark plasma sintering (SPS) method and presents their structural, microstructural, dielectric, ferroelectric and magnetic characteristics. The matrix was the ferroelectric phase, i.e., (1 − x)PMN(x)-PT (PP) material (with x from 0.25 to 0.40), while the magnetic phase was nickel-zinc ferrite (F) in the PP-F composite materials. The X-ray diffraction analysis (XRD) tests revealed that the crystal structure is transformed from the rhombohedral (for x = 0.25) to the tetragonal phase (for x = 0.40) in the PMN-PT component of the composite, and both phases coexist when x = 0.31, 0.34, and 0.37. The energy dispersive spectrometry (EDS) tests confirmed the stoichiometry of the elements in the composite samples, whereas the elemental mapping (for iron and lead) recorded regions of higher saturation for areas with a higher content of the magnetic or ferroelectric phases. The dielectric study of the PP-F composite samples showed high permittivity and small values of the dielectric loss tangent, in the range of 1735–13070 and 0.03–0.32, respectively (at room temperature), while the ferroelectric study showed properly saturated hysteresis loops with high remnant polarization (from 7.62 to 11.47 μC/cm2). The magnetic properties are typical for ferroelectro-ferromagnetic composite materials with slim magnetic hysteresis loops, whereas the change in the ferroelectric phase type does not affect the magnetic properties of the PP-F multiferroic composite. Furthermore, the study showed that the SPS method improves the sinterability of the material while maintaining the high performance parameters of the composite samples and simultaneously considerably lowers the temperature and shortens the processing of the PP-F multiferroic composites.

Detailed electrical characterization of 200 mm CMOS compatible GaN/Si HEMTs down to deep cryogenic temperatures

A detailed electrical characterization and transistor parameter extraction on 200 mm CMOS compatible GaN/Si HEMTs was performed down to deep cryogenic temperatures. The main transistor parameters (threshold voltage Vth, low-field mobility μ0, subthreshold swing SS, source-drain series resistance Rsd) were extracted in linear region using the Y-function and the Lambert-W function methods for gate lengths down to 0.1 µm. The Y-function method was also employed in saturation region for the extraction of the saturation velocity. The results indicate that these GaN/Si HEMT devices demonstrate a very good functionality down to very low temperature with improvement of mobility and subthreshold slope. It was also shown by TLM analysis that the source-drain series resistance Rsd is more limited by the contact resistance than by the 2DEG access region resistance as temperature is lowered.

Modified Winding Function Analysis of Synchronous Reluctance Motor for Design Iteration Purposes

This article proposes a hybrid analytical modeling procedure for the performance parameter estimation of synchronous reluctance machine, including its operation in the region of magnetic saturation. The proposed model better estimated the torque profile through improved translation and stepped transition of rotor flux barriers. The non-linear operation is simulated by considering the global saturation and estimating the machine’s operating point on the magnetization curve of the core material. The procedure formulation focuses on improving the accuracy and rapidness of the iterative design process. The obtained results are validated against an already established design analysis technique, finite-element analysis, and the frequency spectrum analysis of practical machine results. With the improved accuracy and the least requirement of simulation runtime and computational resources, the modeling procedure can be utilized as an initial design iteration tool.

PreMSat: Preventing Magnetic Saturation Attack on Hall Sensors

Spoofing a passive Hall sensor with fake magnetic fields can inject false data into the downstream of connected systems. Several works have tried to provide a defense against the intentional spoofing to different sensors over the last six years. However, they either only work on active sensors or against externally injected unwanted weak signals (e.g., EMIs, acoustics, ultrasound, etc.), which can only spoof sensor output in its linear region. However, they do not work against a strong magnetic spoofing attack that can drive the passive Hall sensor output in its saturation region. We name this as the saturation attack. In the saturation region, the output gets flattened, and no information can be retrieved, resulting in a denial-of-service attack on the sensor.Our work begins to fill this gap by providing a defense named PreMSat against the saturation attack on passive Hall sensors. The core idea behind PreMSat is that it cangenerate an internal magnetic field having the same strength but in opposite polarity to external magnetic fields injected by an attacker. Therefore, the generated internal magnetic field by PreMSat can nullify the injected external field while preventing: (i) intentional spoofing in the sensor’s linear region, and (ii) saturation attack in the saturation region. PreMSat integrates a low-resistance magnetic path to collect the injected external magnetic fields and utilizes a finely tuned PID controller to nullify the external fields in real-time. PreMSat can prevent the magnetic saturation attack having a strength up to ∼4200 A-t within a frequency range of 0 Hz–30 kHz with low cost (∼$14), whereas the existing works cannot prevent saturation attacks with any strength. Moreover, it works against saturation attacks originating from any type, such as constant, sinusoidal, and pulsating magnetic fields. We did over 300 experiments on ten different industry-used Hall sensors from four different manufacturers to prove the efficacy of PreMSat and found that the correlation coefficient between the signals before the attack and after the attack is greater than 0.94 in every test case. Moreover, we create a prototype of PreMSat and evaluate its performance in a practical system — a grid-tied solar inverter. We find that PreMSat can satisfactorily prevent the saturation attack on passive Hall sensors in real-time.

Effect of gradually expanding flow passages on flow boiling of micro pin fin heat sinks

In this paper, effect of gradually expanding flow passages on saturated flow boiling characteristics of micro pin fin heat sinks is experimentally investigated. In this regard, a comparative analysis is performed based on three different heat sinks having straight parallel channels, uniformly distributed micro pin fins, and decreasing number of micro pin fins in flow direction. For these three geometries, visualization supported experiments are conducted, approximately, at the mass flux of 212 kg m–2 s–1, inlet temperature of 75 ± 1 ᵒC and effective heat fluxes of 132 – 272 kW m–2. Working fluid was deionized water. It is concluded that gradually expanding flow passages towards the outlet significantly improves the two-phase heat transfer coefficient up to nearly 501% and 365% compared to straight parallel channels and uniformly distributed micro pin fins, respectively. The structure having decreasing number of micro pin fins obviously suppresses flow boiling instabilities, and also presents lower pressure drop (lower up to 1.45 times) than uniformly distributed micro pin fins. Gradually enlarging flow passages provide escape-ways in the highly saturated region; thus, accelerate the flow and shorten the waiting period of vapor on heat transfer surface. Important conclusions are obtained regarding flow mechanism via flow images.

A novel class-E class-D doherty power amplifier based on past matching network with linearity region extension and flat output power

In this paper, a Doherty power amplifier (DPA) is proposed consisting of class-E as the main branch and class-D as the auxiliary power amplifier (PA). Past matching network is applied in the proposed DPA to control the output impedance and reduce its deviation from matching point, which provides improved bandwidth characteristic. The use of λ/4 lines for inductor modeling, employing power divider and input/output matching networks based on micro-strip stubs result in size reduction of proposed DPA, better isolation of the ports and lower return loss. The proposed Doherty structure is based on class-E in main branch and class-D in auxiliary branch, which provides high efficiency, and high output power in 2.7–3.5 GHz frequency band. The proposed DPA has drain efficiency of 65.4% and the gain of 18.6 dB in P-1dB point (27 dBm input power) where in this point, the output power is 45.87 dBm. In the saturation region, the output power of 48.6 dBm and drain efficiency of 93.7% can be obtained in the proposed DPA as shown in simulation results.

A Novel Mesh‐Based Equivalent Magnetic Network for Deep Saturation Region of Permanent Magnet Machine

AbstractPartial deep saturation of magnetic circuit is common in short‐term working permanent magnet (PM) machines in aviation, aerospace, new energy power generation and other fields. In order to accurately calculate the electromagnetic characteristics of the short‐term working machine, a novel mesh‐based equivalent magnetic network for the deep saturation region is proposed. Firstly, the deep saturation mechanism of the magnetic circuit of short‐term working motor is analyzed, and the deep saturation region is determined; Secondly, a Pointy topped hexagonal segmentation approach (PT‐HSA) grid generation method is proposed to effectively simulate complex magnetic flux paths. The PT‐HSA grid division and node compilation rules were analyzed in detail. In addition, a nonlinear magnetic network model based on reluctance grid model and equivalent magnetic circuit model is established. Compared with the quadrilateral segmentation approach (QSA) model, the calculation results of PT‐HSA model are closer to the finite element simulation results in the loading and instantaneous compensation conditions. Finally, an experimental platform is built, and the accuracy of the PT‐HSA magnetic network model is verified by the experimental results. © 2022 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC.

Dual-Sideband Constant-Envelope Frequency-Hopping Binary Offset Carrier Multiplexing Modulation for Satellite Navigation

Frequency-hopping binary offset carrier modulation improves the anti-interference performance and mitigates the autocorrelation function (ACF) ambiguity problem of binary offset carrier modulation. To save payload resources and make high-power amplifiers on satellites operate at the nonlinear saturation region, there is further demand for finding an efficient constant-envelope frequency-hopping binary offset carrier multiplexing technique to combine several signal components. Thus, we propose a dual-sideband constant-envelope multiplexing modulation, named asymmetric constant-envelope frequency-hopping binary offset carrier multiplexing (ACE-FHBOC), which is also a multicarrier constant-envelope multiplexing modulation. ACE-FHBOC provides higher design flexibility in the number of subcarrier frequencies than ACE-BOC while maintaining the same flexibility of signal design as ACE-BOC in the number of signal components and power ratio among components. We first establish the theory and give implementation methods of ACE-FHBOC. Then, we develop a software-defined receiver to simulate and analyze the performance for several specific ACE-FHBOC and ACE-BOC signals. The results show that the recommended ACE-FHBOC signals have lower ACF ambiguity, better anti-narrowband interference, and multipath performance than ACE-BOC under the same conditions. With these advantages, ACE-FHBOC is a promising solution for the signal design of new generation global navigation satellite systems.

Insights into improved ferroelectric and electrocaloric performance of Ba0.85Ca0.15Ti0.9Zr0.1O3 thick films grown by the electrophoretic deposition

Lead-free Ba0.85Ca0.15Ti0.9Zr0.1O3 (BCZT) bulk ceramics have recently gained attention as one of the attractive candidates for electrocaloric cooling due to their large heat absorption capacity induced by electro-structural phase transition near room temperature. However, adiabatic temperature change (ΔT) at room temperature in ceramics has been limited by their relatively low dielectric breakdown strength. Thick films, in this respect, possess the advantages of ceramics (volume) and thin films (thickness). In this work, a systematic ferroelectric and electrocaloric investigation of BCZT thick films, fabricated by electrophoretic deposition combined with laser annealing, has been carried out. Laser annealing at an optimized energy density of 398 W/cm2 has resulted in densely packed grain morphology with no compositional heterogeneities. Analysis of the scaling behavior of dynamic hysteresis revealed that ferroelectric domain reversal in BCZT/Pt has good stability and low energy consumption in the saturation region. The present thick films exhibited larger breakdown strength of 294 kV/cm and recoverable energy storage density of ∼7.3 J/cm3, at least five-fold enhancement compared to the bulk which is stable up to a 4 mm bending radius. The indirect electrocaloric measurements displayed parameters such as a ΔT and entropy change (ΔS) of 2.94 K and 3.1 J kg−1 K−1 respectively, for 205 kV/cm which are more than two orders increased compared to the bulk. Higher values of ΔT (1.9 K) at 25 °C, refrigerant capacity of 249 J/kg, and responsivity of 0.143 K mm/kV for BCZT/Pt film compared to relevant lead-free ferroelectric thick films elucidate the potential use of these films for solid-state refrigeration applications. The work also presents electrophoretic deposition with laser annealing as an alternative technique to widely studied tape-casting of thick films for electrocaloric studies.

RETRACTED:Increasing electricity generation—Installing photovoltaic cells coupled to a battery pack, to provide the electricity

By 2050, renewables should increase the share of electricity generation to 70 %. According to the net-zero long-term plan, solar energy is at the forefront of renewable sources. The concreted solar plant is one of the best renewable-based electricity generation utilities that can combine with solar cells and battery systems. In this study, basic modelling for counter flow shell-tube type heat exchanger is developed in which melted salt and steam/water are the two-working fluid of the heat exchanger. A two-phase heat transfer analysis has been considered for the boiling phenomena in the saturated steam region. The study is performed for 5 kg·s−1 flow rate of steam/water and for different flow rate of melted salt varying from 75 kg·s−1 to 300 kg·s−1. Thermodynamic characteristics of the heat exchanger, such as, vapor quality and convective coefficient variation of the steam/water along the length of the heat exchanger has been presented. In addition, temperature profile of the melted salt and the steam/water along the length of the heat exchanger is determined in this study. Numerical analysis affirmed that the battery cooling was successful at Reynolds number of 200–500 as the maximum temperature was lower 320 K.

Using Multi-Source Geospatial Information to Reduce the Saturation Problem of DMSP/OLS Nighttime Light Data

The DMSP/OLS Nighttime light (NTL) data directly reflect the spatial distribution and light intensity of artificial lighting from the Earth’s surface at night, and has become an emerging instrument for urbanization research, including in the monitoring of urban expansion, assessment of socio-economic vitality, and estimation of energy consumption and population. However, due to the imperfect sensor design of DMSP/OLS, the dynamic range of the digital number (DN) of NTL is limited (0, 63), leading to a significant saturation problem when describing the actual light intensity, especially in dense urban areas with high light intensity. This saturation problem masks spatial differences in light intensity and weakens the reliability of DMSP/OLS NTL data. Therefore, this study proposes a novel desaturation indicator that combines NDBI and POI, the Building and POI Density-Adjusted Nighttime Light Index (BPANTLI), to regulate the DMSP/OLS NTL saturation problem based on the spatial characteristics of urban structures and human activity intensity. The proposed method is applied to three urban agglomerations with the most severe light saturation issues in China. The geographical detector model is firstly utilized to quantify the effectiveness of NDBI and POI in reflecting the difference in light intensity distribution from the NTL potential saturation region (NTL DN value (53, 63)) and NTL unsaturation region (NTL DN value (0, 52)), so as to clarify the feasibility of developing the BPANTLI. The applicability of BPANTLI is validated through three aspects—comparison of the desaturation capacity and the performance of delineating light intensity; verification of the consistency of BPANTLI with radiometric calibration nighttime light product (RCNTL) and NPP/VIIRS data; and assessing the accuracy of the BPANTLI in estimating socio-economic parameters (GDP, electricity consumption, population density). The results indicate that the BPANTLI possesses superior capability in regulating the NTL saturation problem, achieving good performance in distinguishing inner-urban structures. The regulated results reveal a remarkably improved correspondence with the RCNTL and NPP/VIIRS data, providing a more realistic picture of the light intensity distribution. It is worth noting that, given the advantages of NDBI and POI vector data in spatial resolution, the BPANTLI established in this study can overcome the limitation of the spatial resolution of DMSP/OLS nighttime lighting data and achieve dynamic transformation of the spatial resolution. The higher spatial resolution desaturation results allow for a better characterization of the light intensity distribution. Moreover, the BPANTLI-regulated light intensity significantly improves the accuracy of estimating electricity consumption, GDP, and population density, which provides a valuable reference for urban socio-economic activity assessment. Thus, the BPANTLI proposed in this study can be considered as a reasonable desaturation method with a high application value.

Temperature-Dependent Threshold Voltage Extraction of FinFETs Using Noise Measurements

In this article, a temperature-dependent threshold voltage extraction method based on noise measurement is proposed. This method induces a mathematical solution for acquiring channel temperatures ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$T$ </tex-math></inline-formula> ) of transistors in the saturation region to extract threshold voltages. In order to gain accurate channel temperature, a small-signal equivalent circuit model was established to determine transconductance ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$g_{m}$ </tex-math></inline-formula> ). Then, the extracted transconductance and measured noise power spectral density (NPSD) were used to obtain channel temperatures. On this basis, the temperature-dependent threshold voltage ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$V_{\mathrm {th}}$ </tex-math></inline-formula> ) was derived. To validate the reliability of this method, a four-Fin six-finger N-FinFET and a four-Fin eight-finger N-FinFET were fabricated using the 14-nm bulk FinFET technology. In this study, the scattering parameters were obtained from 0.2 to 40.2 GHz. Also, the NPSDs were measured from 1 to 500 Hz, while gate voltage and drain voltage were set as 0.3, 0.49, and 0.75 V. Besides, the transistor <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$I_{\mathrm {ds}}$ </tex-math></inline-formula> – <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$V_{\mathrm {ds}}$ </tex-math></inline-formula> characteristics was also investigated when drain–source bias voltage changed from 0.05 to 0.9 V. Compared with the measurement results, the calculation results of drain–source current model using temperature-dependent threshold voltage achieved higher accuracy. Also, the root mean square errors (RMSEs) were less than 0.60% for four-Fin six-finger N-FinFET and less than 0.51% for four-Fin eight-finger N-FinFET. Therefore, the proposed extraction method can be applied to accurately predict transistor temperature-dependent threshold voltage.

Semi-analytical solution for undrained cylindrical cavity expansion in variably saturated soils

The effect of different initial degrees of saturation on the behaviour of variably saturated soils around an expanding cavity has not been adequately studied thus far. Therefore, this study aimed to fill this gap. Moreover, it sought to theoretically explain the cylindrical cavity expansion response in unsaturated three-phase media, particularly focusing on its effect on the cavity wall during the transition from an unsaturated to a saturated state. To this end, a semi-analytical solution based on a hydro-mechanically coupled Sheng–Fredlund–Gens model was proposed for the undrained cavity expansion problem in variably saturated soils in which unsaturated and fully saturated regions coexisted around the cavity. The cylindrical cavity expansion and expansion pressure response in initially unsaturated soils (considering different initial degrees of saturation) and initially fully saturated soils were explored. The proposed solution further extends the cavity expansion theory to unsaturated soils. Furthermore, this work could serve as a theoretical framework for modelling of the cavity expansion problem in the variably saturated soils considering the effect of hydraulic state transition.

Elimination of Image Saturation Effects on Multifractal Statistics Using the 2D WTMM Method.

Imaging artifacts such as image saturation can restrict the computational analysis of medical images. Multifractal analyses are typically restricted to self-affine, everywhere singular, surfaces. Image saturation regions in these rough surfaces rob them of these core properties, and their exclusion decreases the statistical power of clinical analyses. By adapting the powerful 2D Wavelet Transform Modulus Maxima (WTMM) multifractal method, we developed a strategy where the image can be partitioned according to its localized response to saturated regions. By eliminating the contribution from those saturated regions to the partition function calculations, we show that the estimation of the multifractal statistics can be correctly calculated even with image saturation levels up to 20% (where 20% is the number of saturated pixels over the total number of pixels in the image).

Revenue Stacking for BESS: Fast Frequency Regulation and Balancing Market Participation in Italy

Battery energy storage systems (BESS) are considered a relevant flexible resource for supporting the balancing of a RES-penetrated power grid. Since their cost structure is characterized by very high capital costs, it is of utmost importance to ensure efficient and effective operations from a techno-economic perspective. The possibility of services (and revenues) stacking is one of the most discussed optimization solutions. The present work provides a novel approach for BESS modeling, including the stacking of two diverse ancillary services, a dedicated balancing market bidding model, and a state-of-charge management strategy. Fast frequency regulation is proposed as a power-based service, requiring large ramping capability, but asking BESS activation just for a limited amount of time. For the remainder, BESS power can be traded on balancing market (BM): energy-based services, such as tertiary regulation, could be effectively coupled with power-based, fast regulations, increasing the economic attractiveness of investments in BESS. The case of fast reserve (FR), a new high-speed frequency response service proposed by the Italian TSO in Italy, is assessed in this study. FR provision foresees a capacity-based remuneration (k€/MW/year) and requires to ensure 1000 hours per year of availability. After assessing its cost-effectiveness as a stand-alone service, a sequential multiservice strategy is proposed, where BESS provides FR for 1000 hours, while for the rest of the time it is dedicated to the provision of replacement reserve (RR). Performances of BESS are evaluated considering the reliability of the provision, its operational efficiency, and investment’s economics. Performed tests demonstrate how, within the current Italian regulatory framework, the investment’s rate of return improves thanks to the multiservice approach. In particular, while maintaining a proper reliability, the minimum acceptable remuneration from FR yearly auctions decreases by 13%; at the same time, self-dispatching of energy through BM calls reduces the need to purchase energy on day-ahead market and keeps BESS state-of-charge far from saturation regions, thus also increasing its lifetime.

Stability of intermediate states in the surface lithiation process of silicene

We have studied using density functional theory the Li-silicene system, mainly in the saturated region (0.11>X(Li)<1.0) which is critical to understand the solid electrolyte interface layer (SEI) formation. The electronic and vibrational properties of the intermediate states of lithiated silicene were calculated. Two models were used for the Li atoms on the silicene surface: Li on top of Si (perpendicular) and Li on top of the hexagon center (centered). The centered configurations have lower Eb values up to X(Li) = 0.33. However, the vibrational properties showed instabilities for lithium in the hexagon center. An intermediate state at X(Li) = 0.38 was found to be dynamically stable. A metallic to semiconductor transition is observed at X(Li) = 0.33, and X(Li) = 0.46. Few ordered vacancies or vacancies in the dilute region exhibit vibrational stability and gap opening. Elastic stiffness tensor for different concentrations of Li in the silicene-Li system were calculated, a critical concentration of X(Li)=0.333 was determined for the change of the mechanical properties behavior. silicel has a slightly higher 2D Young‘s moduli than silicene. However, vacancies in silicel produce a substantial decrement in mechanical properties.

Enhancement of the polydimethylsiloxane (PDMS) luminescence to develop a proton scintillator

The polydimethylsiloxane (PDMS) luminescence, induced by MeV proton beams, has been investigated in the pure and doped polymer. Gold nanoparticles (AuNPs) and graphene oxide microparticles (GOμPs) have been employed at low concentration (0.1 wt%) to modify the PDMS properties. Measurements have demonstrated that AuNPs enhance the PDMS luminescence, while GOμPs quench the polymer luminescence. The first ones, embedded into PDMS, produce a visible luminescence whose intensity is proportional to the absorbed proton dose. A linearity between the luminescence intensity and the proton absorbed dose is observed up to about 2.5 kGy, while at higher doses a luminescence saturation region shows up. The polymer can be employed to monitor in vacuum the proton beam spot size and shape and as a plastic scintillator dosimeter with peculiar elastic properties and high biocompatibility, as it will be presented and discussed.

Optical and magneto-optical properties of bismuth-substituted neodymium iron gallium garnet films on glass substrates at the 1310-nm and 1550-nm wavelengths

We describe measured results of optical and magneto-optical (MO) properties of bismuth-substituted neodymium iron gallium garnet (Bi1Nd2Fe4Ga1O12, Bi1:NIGG) films prepared by spin coating on glass substrates and crystallized by metal–organic decomposition (MOD) method in the near-infrared (NIR) wavelengths of 1310 nm and 1550 nm. The optical constants of the Bi1:NIGG films were determined with a spectrophotometer measurement. The measured refractive index and absorption coefficient were about 1.835 and 55.8 cm−1, respectively, at the 1310 nm wavelength and about 1.837 and 29.8 cm−1 at the 1550 nm wavelength. The MO properties of the films were determined by measuring the Faraday rotation in the saturated magnetization region. The measured maximum Faraday rotation of the Bi1:NIGG film of about 1055-nm thickness was 0.032 °/μm and 0.016 °/μm at 1310-nm and 1550-nm wavelengths, respectively. The corresponding Figure-of-Merits (FoMs) were 5.64 deg/dB and 5.22 deg/dB at each wavelength. Our measured result indicates that the Bi1:NIGG films prepared by the MOD method are useful for integrated optical isolator and MO sensor applications because of relatively good optical transparency and MO characteristics.

A Dynamic Analysis of Retail Infrastructure and Tourism Demand: Evidence from a Casino Destination

ABSTRACT This study used a panel cointegration approach to investigate the effect of retail infrastructure/facilities on tourism demand in the casino gaming destination, Macao, from 23 provinces (and municipalities) of mainland China. Numbers of retail outlets in general and retail establishments in integrated resorts (IRs) are used as proxies for retail infrastructure/facilities. Dynamic Ordinary Least Square (DOLS) estimations reveal that a positive long-run relationship exists between tourism demand and retail from both dimensions. Heterogeneous results on the individual province estimates suggest visitors from the emerging central and western regions of China respond more strongly to retail facilities than the more saturated southern and eastern regions. The bidirectional causality between retail infrastructure and tourism demand also validates a positive cycle in the long-term growth of the destination. The results suggest that casino gaming destinations should seek to diversify entertainment and capitalize on the competitive advantage of their non-gaming facilities to sustain long-term development.