Transmission In Region Research Articles

Charting a course to efficient difference frequency generation in molecular-engineered liquid-core fiber.

Although χ(2) nonlinear optical processes, such as difference frequency generation (DFG), are often used in conjunction with fiber lasers for wavelength conversion and photon-pair generation, the monolithic fiber architecture is broken by the use of bulk crystals to access χ(2). We propose a novel solution by employing quasi-phase matching (QPM) in molecular-engineered hydrogen-free, polar-liquid core fiber (LCF). Hydrogen-free molecules offer attractive transmission in certain NIR-MIR regions and polar molecules tend to align with an externally applied electrostatic field creating a macroscopic χ e f f(2). To further increase χ e f f(2) we investigate charge transfer (CT) molecules in solution. Using numerical modeling we investigate two bromotrichloromethane based mixtures and show that the LCF has reasonably high NIR-MIR transmission and large QPM DFG electrode period. The inclusion of CT molecules has the potential to yield χ e f f(2) at least as large as has been measured in silica fiber core. Numerical modeling for the degenerate DFG case indicates that signal amplification and generation through QPM DFG can achieve nearly 90% efficiency.

Electro‐osmotic driven flow of Eyring Powell nanofluid in an asymmetric channel

This article aims to investigate the electro‐osmotic flow of the Eyring‐Powell nanofluid under the peristaltic mechanism with the influence of the porous medium in the micro‐channel. The modified system is applied externally to an electrical field in the horizontal direction and a magnetic field in the transverse direction. Governing equations of nanofluid flow are formulated, and the assumptions of low Reynolds number and large wavelength approximations are tackled. The resulting coupled non‐linear partial differential equations like velocity and temperature equations are solved numerically by the NDSolve command using the computational mathematical software Mathematica. The influence of various important parameters on the velocity of the fluid, the temperature profiles, and the trapping phenomenon are discussed in detail by graphs. Under the influence of Joule heating, the study details the thermal transport process in the fluid. It demonstrates how an increase may significantly improve the momentum transmission in the core region of the microchannel in the volume fraction of the nanoparticles in the fluid.

Estimation of Spatial Features in 3-D-Sensor Network Using Multiple LiDARs for Indoor Monitoring

In recent years, smart city has been attracting attention as a sustainable urban development. Smart monitoring is one of the key components of a smart city, and Light-Detection-and-Ranging (LiDAR) sensor is used as one of the sensors for smart monitoring. A 3D sensor network using multiple LiDAR sensors can be constructed to eliminate blind spots. Prior work presented a system that prioritizes transmission in important regions to prevent data loss in the case of bandwidth limitation. However, prior work has only presented transmission methods and has not shown how to estimate important regions in the point cloud space. This paper proposes a system to estimate important regions using spatial features created based on multiple spatial metrics. The important regions vary from task to task, and in particular, for the task of detecting moving objects, the important regions are the spaces where the moving objects may be located. The accuracy of estimation can be improved by creating spatial features based on more spatial metrics. This paper addresses two kinds of spatial metrics, temporal metric and statistical metric. In this work, we collect point-cloud data using multiple LiDAR sensors and produce datasets with labels for evaluation. Using datasets, we validate the proposed system in terms of the accuracy of spatial feature estimation.

Phase shifting transformer to reduce power congestions and to redistribute power in interconnected systems

<span lang="EN-US">The increased penetration of wind and solar power, as well as the liberalized electricity market, makes the power system network interconnected and complex. As the power demand is increasing daily, the complexity of operating large power systems is also increasing. Congestion in the transmission network may become more common than previously, making power flow management a problem that becomes increasingly important. Unexpected power flows (also known as loop flows) are becoming a bigger issue in today's linked power networks. These flows have a detrimental impact on the safe functioning of integrated power networks, which hinders their ability to conduct cross-border trade. Phase shifting transformers (PSTs) allow real power flow to be controlled by changing the phase shift across the device. This study deals with two interconnected parallel power system networks and the power flow controlled through a PST in between. The simulation results emphasize the importance of the PST in facilitating the transfer of energy throughout the regional transmission interconnection.</span>

Analytical investigation of GeO2-doped optical fibers to build Brillouin lasers at 1300 nm

The 1.5 µm spectral region concentrates the most substantial attention on building fiber laser sources for communications applications. However, data transmission in this spectral region is quite congested, requiring exploring new neighboring regions. In particular, 1.3 µm, usually defined as the zero-dispersion band, currently constitutes an active field of research, and the development of fiber laser sources in this wavelength band is of substantial interest to expand the capabilities of existing photonic operations. Previous experimental investigations have already shown that the peak stimulated Brillouin scattering efficiency is strongly affected by the concentration of GeO2 doping in single-mode fibers. In this context, this work presents an analytical investigation of the performance of a Brillouin fiber laser at 1.3 µm using optical fibers doped with different GeO2 concentrations as a Brillouin gain medium. The results obtained suggest that optical fibers doped with high GeO2 concentrations can be a simple and effective solution to build Brillouin lasers with better efficiency in the 1.3 µm band employing shorter fiber lengths with low pump power values.

Normalized mutual information of fNIRS signals as a measure for accessing typical and atypical brain activity.

Normalized mutual information (NMI) can be used to detect statistical correlations between time series. We showed possibility of using NMI to quantify synchronicity of information transmission in different brain regions, thus to characterize functional connections, and ultimately analyze differences in physiological states of brain. Resting-state brain signals were recorded from bilateral temporal lobes by functional near-infrared spectroscopy (fNIRS) in 19 young healthy (YH) adults, 25 children with autism spectrum disorder (ASD), and 22 children with typical development (TD). Using NMI of the fNIRS signals, common information volume was assessed for each of three groups. Results showed that mutual information of children with ASD was significantly smaller than that of TD children, while mutual information of YH adults was slightly larger than that of TD children. This study may suggest that NMI could be a measure for assessing brain activity with different development states.

Intraday markets, wind integration and uplift payments in a regional U.S. power system

U.S. electricity markets adopt a two-settlement structure with day-ahead and real-time markets. Wind power integration poses a challenge for this market structure because day-ahead wind production forecasts are uncertain and significant rescheduling costs may occur in real time, increasing the need for out-of-market uplift payments. We investigate whether a multi-settlement structure with four intraday stages taking place 18 to 3 h before electricity generation reduces uplift payments and system costs, relative to a two-settlement structure. We develop unit commitment and dispatch models that account for intertemporal constraints and solve them on a 36-node test system using historical wind forecasts provided by a Regional Transmission Organization, as well as synthetic wind forecasts reproducing the observed correlation in the historical data. Combining historical and simulated forecasts allows us to account for wind uncertainty and draw more robust conclusions about the relative merits of each market structure. Finally, we compare the performance of market designs under varying levels of wind penetration. Under any level of wind penetration, the proposed multi-settlement market design is more likely to yield higher uplift than the two-settlement market design. Wind forecast accuracy and structural differences between the U.S. and European electricity markets are key drivers of our results.

Evaluation of an Engineered Zika Virus-Like Particle Vaccine Candidate in a Mosquito-Mouse Transmission Model.

The primary route of Zika virus (ZIKV) transmission is through the bite of an infected Aedes mosquito, when it probes the skin of a vertebrate host during a blood meal. Viral particles are injected into the bite site together with mosquito saliva and a complex mixture of other components. Some of them are known to play a key role in the augmentation of the arbovirus infection in the host, with increased viremia and/or morbidity. This vector-derived contribution to the infection is not usually considered when vaccine candidates are tested in preclinical animal models. In this study, we performed a preclinical validation of a promising ZIKV vaccine candidate in a mosquito-mouse transmission model using both Asian and African ZIKV lineages. Mice were immunized with engineered ZIKV virus-like particles and subsequently infected through the bite of ZIKV-infected Aedes aegypti mosquitoes. Despite a mild increase in viremia in mosquito-infected mice compared to those infected through traditional needle injection, the vaccine protected the animals from developing the disease and strongly reduced viremia. In addition, during peak viremia, naive mosquitoes were allowed to feed on infected vaccinated and nonvaccinated mice. Our analysis of viral titers in mosquitos showed that the vaccine was able to inhibit virus transmission from the host to the vector. IMPORTANCE Zika is a mosquito-borne viral disease, causing acute debilitating symptoms and complications in infected individuals and irreversible neuronal abnormalities in newborn children. The primary vectors of ZIKV are Aedes aegypti mosquitoes. Despite representing a significant public health burden with a widespread transmission in many regions of the world, Zika remains a neglected disease with no effective antiviral therapies or approved vaccines. It is known that components of the mosquito bite lead to an enhancement of viral infection and spread, but this aspect is often overlooked when vaccine candidates undergo preclinical validation. In this study, we included mosquitoes as viral vectors, demonstrating the ability of a promising vaccine candidate to protect animals against ZIKV infections after the bite of an infected mosquito and to also prevent its further transmission. These findings represent an additional crucial step for the development of an effective prevention tool for clinical use.

A multi-faceted role of dual-state dopamine signaling in working memory, attentional control, and intelligence.

Genetic evidence strongly suggests that individual differences in intelligence will not be reducible to a single dominant cause. However, some of those variations/changes may be traced to tractable, cohesive mechanisms. One such mechanism may be the balance of dopamine D1 (D1R) and D2 (D2R) receptors, which regulate intrinsic currents and synaptic transmission in frontal cortical regions. Here, we review evidence from human, animal, and computational studies that suggest that this balance (in density, activity state, and/or availability) is critical to the implementation of executive functions such as attention and working memory, both of which are principal contributors to variations in intelligence. D1 receptors dominate neural responding during stable periods of short-term memory maintenance (requiring attentional focus), while D2 receptors play a more specific role during periods of instability such as changing environmental or memory states (requiring attentional disengagement). Here we bridge these observations with known properties of human intelligence. Starting from theories of intelligence that place executive functions (e.g., working memory and attentional control) at its center, we propose that dual-state dopamine signaling might be a causal contributor to at least some of the variation in intelligence across individuals and its change by experiences/training. Although it is unlikely that such a mechanism can account for more than a modest portion of the total variance in intelligence, our proposal is consistent with an array of available evidence and has a high degree of explanatory value. We suggest future directions and specific empirical tests that can further elucidate these relationships.

The Cause and Correlation Network of Air Pollution from a Spatial Perspective: Evidence from the Beijing–Tianjin–Hebei Region

Based on the Spatial Durbin Model (SDM), this study evaluates the spatial spillover effect of PM2.5 concentration in Beijing–Tianjin–Hebei (BTH) and its surrounding areas from 2000 to 2016, analyzes its main influencing factors and verifies the Environmental Kuznets Curve (EKC). In addition, Social Network Analysis (SNA) is used to measure the regional air pollution transmission network. The results are as follows: (1) A significant inverted U-shaped EKC with spatial spillover effect between the sampled 48 cities was verified. (2) Industrial structure had both local and spillover effects on air pollution with a U-shaped curve; technological progress exerted a negative spillover effect on air pollution, while traffic evidenced positive local and spillover effects; meteorological conditions showed different impacts on air pollution. (3) Heze, Tianjin, Xingtai, Shijiazhuang and Liaocheng are the top five cities in the centrality of the air pollution correlation network, indicating air pollution in these cities have significant impacts on other cities within the network; while Sanmenxia, Weihai, Yuncheng, Langfang and Zhumadian are the bottom five cities, which indicates that the air pollution of these cities has the least correlation with other cities. The policy suggestions for 48 cities involve: building up a regional joint prevention and control mechanism, enhancing the supervision of cities located in the centrality of the air pollution correlation network, accelerating high-tech and service-oriented industrialization, encouraging technological innovation in energy conservation and environmental protection and implementing vehicle regulation.

Development of RPA-Cas12a-fluorescence assay for rapid and reliable detection of human bocavirus 1.

Human bocavirus (HBoV) 1 is considered an important pathogen that mainly affects infants aged 6-24 months, but preventing viral transmission in resource-limited regions through rapid and affordable on-site diagnosis of individuals with early infection of HBoV1 remains somewhat challenging. Herein, we present a novel faster, lower cost, reliable method for the detection of HBoV1, which integrates a recombinase polymerase amplification (RPA) assay with the CRISPR/Cas12a system, designated the RPA-Cas12a-fluorescence assay. The RPA-Cas12a-fluorescence system can specifically detect target gene levels as low as 0.5 copies of HBoV1 plasmid DNA per microliter within 40 min at 37°C without the need for sophisticated instruments. The method also demonstrates excellent specificity without cross-reactivity to non-target pathogens. Furthermore, the method was appraised using 28 clinical samples, and displayed high accuracy with positive and negative predictive agreement of 90.9% and 100%, respectively. Therefore, our proposed rapid and sensitive HBoV1 detection method, the RPA-Cas12a-fluorescence assay, shows promising potential for early on-site diagnosis of HBoV1 infection in the fields of public health and health care. The established RPA-Cas12a-fluorescence assay is rapid and reliable method for human bocavirus 1 detection. The RPA-Cas12a-fluorescence assay can be completed within 40 min with robust specificity and sensitivity of 0.5 copies/μl.

Research on power gathering problem and power transmission strategy in Guangxi coastal area

the construction of power supply is affected by resource conditions, plant construction conditions, load distribution and power grid structure, which shows a trend of more and more centralized distribution.If the power supply is too concentrated, the short circuit current will be increased, the risk of system security and stability will be increased, and the regional power transmission channel will be insufficient.The key to solve these problems is to find a suitable power transmission strategy.On the basis of fully summarizing the typical structure of domestic power grid, this paper puts forward the construction strategy of group transmission and layered transmission, and applies it to the construction of clean energy transmission grid in Guangxi coastal areas.

SSRIs differentially modulate the effects of pro-inflammatory stimulation on hippocampal plasticity and memory via sigma 1 receptors and neurosteroids

Certain selective serotonin reuptake inhibitors (SSRIs) have anti-inflammatory effects in preclinical models, and recent clinical studies suggest that fluvoxamine can prevent deterioration in patients with COVID-19, possibly through activating sigma 1 receptors (S1Rs). Here we examined potential mechanisms contributing to these effects of fluvoxamine and other SSRIs using a well-characterized model of pro-inflammatory stress in rat hippocampal slices. When hippocampal slices are exposed acutely to lipopolysaccharide (LPS), a strong pro-inflammatory stimulus, basal synaptic transmission in the CA1 region remains intact, but induction of long-term potentiation (LTP), a form of synaptic plasticity thought to contribute to learning and memory, is completely disrupted. Administration of low micromolar concentrations of fluvoxamine and fluoxetine prior to and during LPS administration overcame this LTP inhibition. Effects of fluvoxamine required both activation of S1Rs and local synthesis of 5-alpha reduced neurosteroids. In contrast, the effects of fluoxetine did not involve S1Rs but required neurosteroid production. The ability of fluvoxamine to modulate LTP and neurosteroid production was mimicked by a selective S1R agonist. Additionally, fluvoxamine and fluoxetine prevented learning impairments induced by LPS in vivo. Sertraline differed from the other SSRIs in blocking LTP in control slices likely via S1R inverse agonism. These results provide strong support for the hypothesis that S1Rs and neurosteroids play key roles in the anti-inflammatory effects of certain SSRIs and that these SSRIs could be beneficial in disorders involving inflammatory stress including psychiatric and neurodegenerative illnesses.

Study the effect oxidation time on physical properties of cdo thin films prepared by thermal evaporated

thin films were prepared by thermal evaporated method of cadmium metal on a glass substrate, then conventional oxides in air at 500ᵒC and different oxidation times (30, 60 and 90) mint. The characterization of samples were carried out by atomic force microscopy and UV-VIS spectroscopy. Detailed optical and morphological properties of the prepared films are presented at different oxidation times. A UV-VIS transmition spectrum of produced films shows high transmission in visible, IR region and low transmission in UV region. Average grain size in the range of nanometer and decreases with increasing oxidation time.

Photoluminescent Er-doped As20Se80 thin films and channel waveguides produced by thermal reflow

The chalcogenide glasses are an excellent material alternative for the poorly developed optics of the mid-infrared region on integrated photonics. Their great transmission in the IR region, the outstanding non-linear optical properties, and the recently explored possibility of processing by thermal reflow have sparked considerable interest in the fabrication of micro and nano-structures with symmetric and smooth surfaces suitable for optical components. The thermal reflow nevertheless is not useful for certain glass compositions since it induces phase separation and crystallization that compromise the optical quality. Rare earth-doped chalcogenides, of great interest for the development of laser and amplifiers, are especially prone to such dehomogenization since they have shown to be difficult to synthesize and process without obtaining fluorescence quenching caused by agglomeration and phase separation. In this work, we demonstrate for the first time that under certain conditions it is possible to induce thermal reflow in Er-doped chalcogenide thin films without inducing agglomeration and extinguishing the erbium emission. The films, produced by the co-evaporation of metallic erbium and As20Se80 glass matrix, demonstrated great molecular flexibility that allows to observe thermal reflow in films with erbium concentrations up to 0.6 at%. We use this thermal reflow in doped ridge channel waveguides (produced by photolithography) to reduce the optical losses and to enhance the fluorescence properties of the material by the rearrangement of the emitting ions. Our study opens the door for the fabrication and processing of rare earth-doped chalcogenide planar devices and their future integration into photonic circuits.

Review of trans-Mediterranean power grid interconnection: A regional roadmap towards energy sector decarbonization

Climate change is becoming an important issue in all fields of infrastructure development. Electricity plays a core role in the decarbonized energy system’s path to a regional zero-emission pattern. A well-built trans-Mediterranean backbone grid can hedge the profound evolution of regional power generation, transmission, and consumption. To date, only Turkey and the Maghreb countries (i.e., Morocco, Algeria, and Tunisia) are connected with the Continental European Synchronous Area. Other south- and east-shore countries have insufficient interconnection infrastructures and synchronization difficulties that have proven to be major hurdles to the implementation of large-scale solar and wind projects and achievement of climate goals. This study analyzes the current trans-boundary grid interconnections and power and carbon emission portfolios in the Mediterranean region. To align with the recently launched new climate target ‘Fit for 55’ program and the accelerated large-scale renewables target, a holistic review of projected trans-Mediterranean grids and their market, technical, and financial obstacles of implementation was conducted. For south- and east-shore countries, major legal and regulatory barriers encompassing non-liberalized market structure, regulation gaps of taxation and transmission tariffs, and the private sector’s access rights need to be removed. Enhancement of domestic grids, substations, and harmonized grid codes and frequency, voltage, and communication technology standards among all trans- Mediterranean countries are physical prerequisites for implementing the Trans-Mediterranean Electricity Market. In addition, the mobilization of capital instruments along with private and international investments is indispensable for the realization of supranational transmission projects. As the final section of the decarbonization roadmap, the development of electric appliances, equipment, and vehicles with higher efficiency is inevitable in the decarbonized building, transportation, and industry sectors.

Middle East energy consumption and potential renewable sources: An overview

Despite having enormous fossil fuel resources, the Middle East is susceptible to drops in oil and gas prices, which hurts the country budget. Even while the Middle Eastern countries that import energy enjoy cheaper energy costs, several of these nations have experienced war, social disorder, and political upheaval, which has made the position of the energy of the region very difficult. Water shortages are another significant issue in the Middle East. This region might be classified as a desert. The management of water resources is becoming more and more important in the area as water shortages become a serious problem. To address the current energy crisis and strengthen energy security, the Middle Eastern governments have established commendable renewable energy projects over the years. However, there is still a sizable gap between the potential of renewable energy and production that can be exploited due to rising demand and population growth. This research reported a description of the energy consumption of the Middle East and the viability of the potential renewable energy. The predicted technical result shows that the Middle East region is rich in potential solar and wind, which is the most probable option to satisfy future energy demands via a regional transmission system owing to the severe intermittent nature of renewable energy resources. In the end, it has been shown that, especially in the Middle East, which depends heavily on fossil fuels for its gross domestic product, several policy options need to be studied and put into place for renewable energy goals to be met.

Aggregator-induced demand response and bidding strategy for electricity market environment based on Ethereum smart contracts

ABSTRACT With the liberalization of the Electricity Market (EM), a secure demand response program (DRP) for real-time decisions is needed to enhance the effectiveness, stability, and security of the EM. Customers play a crucial role in DRP as they can offer flexibility when the market demands it. Nevertheless, the aggregator does not fully understand the customer’s available DR capacity to accurately bid on market transactions. To do so, the article presents a smart contract based on an optimal bidding strategy for an aggregator that considers customer receptiveness. First, we endeavor to determine the customer’s receptiveness concerning various incentives where the home energy management system (HEMS) introduces the employed load adjustment for electrical appliances. Second, the aggregator adopts a rational approach to employing the optimal day-ahead bidding strategy and scheduling for energy storage systems (ESS) to exploit economic benefits. The execution of Ethereum smart contracts in market transactions ensures transparency, security, and superior reliability. A test case with realistic data is presented to demonstrate the usefulness of the proposed bidding strategy. The results confirm that the aggregator determines the optimal bidding value for the next day. An aggregator could generate a profit of $23 from the bidding strategy. The regional transmission system operator delivers 485 kWh of flexibility, of which consumers account for 60% and ESS for 40%, generating a profit of $40 per day. Prosumers selling electricity to the aggregator would make an average profit of $6 per day. Thus, the execution of DRP and a bidding strategy results in economic benefits for the aggregator and other entities in the EM.

Research on power trade potential and power balance between Lancang-Mekong countries and southern China under long-term operation simulation

In order to further promote the interconnection development and construction of the power grids between the Lancang-Mekong countries and Southern China region and facilitate multilateral energy interaction, an assessment mechanism of the power balance and power trade potential between the two areas under long-term operation simulation is proposed. The mechanism first analyzes the energy supply structure, energy use forms, cross-border transmission capacity, and multi-area power trade potential of the power grids of the Lancang-Mekong countries and Southern China. Secondly, a power and electricity optimization model considering the long-period operation characteristics of generating units and regional interconnection transmission constraints is constructed, which can optimize the solution of a typical time-series operation scenario of 8760 h a year and improve the accuracy of regional power trade potential analysis. The results show that the Lancang-Mekong countries and the southern region of China have a significant potential for power trading, and the construction of a unified power trading market is vital for promoting the optimal allocation of power resources, achieving power balance, increasing the proportion of energy consumption, and reducing the cost of electricity consumption.

Базовые принципы укрупненной оценки капитальных вложений в реализацию предложений по развитию региональных газотранспортных систем ПАО “Газпром” на стадии предынвестиционных исследований

Базовые принципы укрупненной оценки капитальных вложений в реализацию предложений по развитию региональных газотранспортных систем ПАО “Газпром” на стадии предынвестиционных исследований