Current Supply Research Articles

Potentialities and Impacts of Biomass Energy in the Brazilian Northeast Region

In Northeast Brazil, the use of biomass for energy generation is settled on traditional productive arrangements, such as a sugarcane production system in the humid Atlantic coastal area and firewood extraction from native tropical dry forests in the west. In parallel, substantial amounts of other biomass sources, such as residues from agricultural or urban processes, are still little used or wholly wasted, fudging the opportunity to generate new value chains based on these biomass sources. We hypothesize that using these non-traditional biomass sources to produce biofuels would significantly increase the regional bioenergy supply. In this context, this article discusses the potential for the production and use of biofuels and bioenergy in Northeast Brazil and its effects on regional development, which may be useful for both private actors and policymakers in the energy sector. The use of biomass sources for energy in the region is significant, reaching approximately 8.8 million tons of oil equivalent (toe) per year, emphasizing the already consolidated production of sugarcane and its derivatives. The use of all biomass resources in the Northeast region could supply around 4% of the Brazilian national electrical energy demand, with an environmental footprint of 0.055 tCO2eq per toe, which would contribute to reducing emissions from the Brazilian energy matrix generation. Regarding the spatial distribution of biomass sources, sugarcane prevails on the coast, firewood and livestock manure in the dryland area towards the west, and municipal solid waste is distributed throughout the region within urban areas. Different from what we expected, the potential energy recovery from municipal waste and animal manure would increase by only 17% the current bioenergy supply. In the future, since the majority of the region presents a semi-arid climate with limited rainfall, to increase the use of biomass as an energy source, there is a need to increase the supply of biomass sources with high efficiency in water use and good yields in drylands. For this, the cultivation and use of cacti and agave, for example, could contribute to making biorefineries viable in the region. Above all, public policies for harnessing bioenergy in NE Brazil must seek opportunities associated with the carbon/decarbonization economy, with studies being needed to assess the technical, economic, social, and environmental viability of future productive arrangements.

The Push to Integrate Mid-Level Providers into Dentistry

The Push to Integrate Mid-Level Providers into Dentistry

Hydrogen fuel cell commercial vehicles in China: Evaluation of carbon emission reduction and its economic value

Fuel cell commercial vehicles (FCCVs) coupled with hydrogen energy will play a critical role in moving towards a low-carbon transport sector. However, the economic value of FCCVs carbon-emissions reduction have been largely overlooked. By adapting the GREET model to Chinese scenarios, this article focuses on the FCCVs carbon-emissions reduction and their economic value, referring to carbon price. The carbon-emissions reduction effect in the FCCVs life cycle ranges from 14.53% to 70.19%, and its economic value ranges from 0.02 to 1.19 yuan/kg-H2 (0.003–0.18 USD/kg-H2), achieving by providing carbon-based subsidies. Importantly, the development of fuel-cell logistics vehicles and fuel-cell heavy-duty trucks should be prioritized. In the future of 2030 and 2060, the value could almost compensate half of the current hydrogen supply cost at some 80 yuan/kg-H2 (12.48 USD/kg-H2). The study thus also provides a scientific reference for policies to extend hydrogen energy into the Chinese carbon trading system.

Forecasting future electric power consumption in Busan New Port using a deep learning model

As smart and environmentally friendly technologies and equipment are introduced in the sea port industry, electric power consumption is expected to rapidly increase. However, there is a paucity of research on the creation of electric power management plans, specifically in relation to electric power consumption forecasting, in ports. In order to address this gap, this study forecasts future electric power consumption in Busan New Port (South Korea's largest container port) and, comparing this with the current standard electric power supply capacity, investigated the feasibility of maintaining a stable electric power supply in the future. We applied a Long Short-Term Memory (LSTM) model trained using electric power consumption and throughput data of the last 10 years to forecast the future electric power consumption of Busan New Port. According to the results, electric power consumption is expected to increase at an annual average of 4.9 % until 2040, exceeding the predicted annual 4.7 % increase in throughput during the same period. Given these results, the current standard electric power supply capacity is forecast to reach only 35 % of demand in 2040, indicating that additional electrical power supply facilities will be needed for stable port operation in the future.

Design and Stability Analysis of a Digital Automatic Power Control Based on a PI Controller for Laser Drivers

Laser diodes are widely used in research and industrial applications in areas such as measurements, communications and health. In most of these applications, stability in the emitted light power is required. This can be realized by modifying the internal parameters, such as the current supply, by using an analog automatic power control (APC). This research presents the design and analysis of a feedback laser driver (digital APC system) based on a proportionall–integral (PI) controller. The controller’s theoretical design acting on the supply current in a laser was obtained by algebraically solving the general equations of a PI controller over a laser described as a steady-state system. The required steady-state model can be determined from the lightl–current curve obtained either from the laser data sheet or experimentally. A posterior numerical analysis shows that the proportional gain of the PI controller is only limited numerically by the reciprocal of the slope efficiency of the laser when the characteristic time of the system is greater than the sampling period. Finally, the APC model was tested in an experimental setting using a laser diode ADL-65052TL at several temperatures. The results show that the proposed relations for the proportional gain and the integral time are valid, achieving the desired power stability with a drift of less than 0.1%.

Experimental study on recycled coarse aggregate of concrete

After water, concrete is the second most consumed substance on the earth, and its extensive use serves as the foundation for the urbanisation of the planet. Additionally, concrete facilitates the growth of metropolitan zones. Approximately 25 billion tonnes of concrete are produced annually on a global scale, according to estimates. The manufacture of concrete requires a growing quantity of aggregate, while the current supply is decreasing. Therefore, it is vital that new aggregate sources be identified. Recycling concrete is growing in importance as it conserves natural resources and reduces the need for disposal by utilising readily available concrete as a source of aggregate for the manufacture of fresh concrete. Due to the fact that recycling concrete conserves natural resources and avoids the need for disposal, this is the case. It is often believed that the use of demolished concrete as a substitute for natural aggregate might lead to numerous issues. This is because all emerging nations are concentrating on the creation of ecologically friendly technology. However, according to a previous study, the use of recycled concrete results in a decrease in the concrete's strength as well as other characteristics. The incorporation of aggregate as one of the basic components in the production of concrete is crucial to the operation. 35 to 40 percent of the entire concrete mixture consists of coarse aggregate. The qualities of the aggregates utilised in the production of concrete also have an effect on the final strength of the concrete. As part of this programme, demolished concrete from a field is collected, reused through a few easy steps to improve its qualities, and then used to produce new concrete. It was discovered that reborn concrete with 100 percent, 75 percent, and 50 percent replacement of aggregate (RCA) at 7 days, 14 days, and 28 days exhibited higher compressive strength than conventional concrete. This was discovered by comparing resurrected concrete to conventional concrete.

The potential importance of exploiting export markets for CO2 transport and storage services in realising the economic value of Scottish CCS

Previous research investigating the UK economy impacts of introducing a new Scottish CO2 Transport and Storage (T&S) industry linked to carbon capture and storage (CCS) has focussed on supply chain and funding requirements in introducing such a new sector to service proximate Scottish industrial emissions via onshore pipelines. However, Scottish plans extend to shipping CO2 from outside Scotland for storage in North Sea reservoirs by also servicing sequestration requirements from elsewhere in the UK and/or overseas. This will involve investment in greater industry capacity but could ease associated domestic funding requirements. Here, we introduce improved economy-wide structural (input-output) data reflecting how a Scottish T&S sector may emerge from current Oil and Gas industry supply chain capacity to a computable general equilibrium (CGE) model, extending to simulate emergence of an export base. Our central finding is that exploiting overseas T&S export opportunities is crucial where the policy aim is to generate greater economic activity without increasing demands on the public purse. However, any extent of real wage bargaining and consequent producer cost pressure as labour demand increases will act to dampen expansionary power, displacing export production and employment, while driving consumer price impacts that limit real income and public budget gains.

A GIS-Based Demand Assessment Methodology To Estimate Electricity Requirements for Health Care Facilities: A Case Study for Uganda

This technical note introduces a methodology to estimate electricity requirement ranges for health care facilities, especially unserved and under-served facilities. It combines a bottom-up approach to assessing the electricity requirements at the facility level with a geographic information system (GIS) based analysis. The methodology is applied to a case study for existing facilities in Uganda in close collaboration with the Ugandan Ministry of Health and the Energy Sector GIS Working Group. Outputs of the analysis are also integrated into Energy Access Explorer, where they can be overlaid with information on current and potential supply, and made available for a dynamic, multicriteria prioritization analysis and the development of customized reports. This methodology will provide a data-driven, integrated approach to planning for the expansion of energy services in health care.

Radial Transport of Io Plasma From the Inner Magnetosphere to the Tail

AbstractThe solar wind‐Jovian magnetosphere‐ionosphere interaction is studied from the global magnetohydrodynamic simulation. The calculation considers the high‐speed solar wind, Io plasma emission, high‐speed rotation, ionospheric ions, and precession of magnetic field, and consequently reproduces the confinement of Jovian magnetic field, distributions of O+ and H+, supply of H+ by the polar wind, the interchange instability, and the current system that maintains co‐rotation. The radial transport process of plasma generated from Io is traceable from this solution, such that the transport mechanism gradually changes from the Io torus to the distant tail. In the transport of Io plasma, the precession plus interchange instability is effective near 10–15 Rj, interchange instability is predominant around 15–20 Rj, and the centrifugal force is predominant beyond 25 Rj. The current system supplies torque from the planet to co‐rotating plasma beyond 25 Rj to compensate the rotation delay. The associated upward field‐aligned current (FAC) is connected to the main emission (ME) in the ionosphere. The polar emission (PE) position coincides with that of downward feedback current of upward FAC causing the ME. High‐speed polar wind develops in the ME and in the polar cap, while slow polar wind develops in lower latitudes. In the middle of transport, Io plasma is mixed around 15 Rj with H+ supplied from the ionosphere by the low‐speed polar wind. Afterward, mixed plasma diffuses outward. The equatorial diffuse emission occurs in the projected position of the plasma mixing process.

Immunogenicity and safety of fractional doses of 17D-213 yellow fever vaccine in children (YEFE): a randomised, double-blind, non-inferiority substudy of a phase 4 trial

Current supply shortages constrain yellow fever vaccination activities, particularly outbreak response. Although fractional doses of all WHO-prequalified yellow fever vaccines have been shown to be safe and immunogenic in a randomised controlled trial in adults, they have not been evaluated in a randomised controlled trial in young children (9-59 months old). We aimed to assess the immunogenicity and safety of fractional doses compared with standard doses of the WHO-prequalified 17D-213 vaccine in young children. This substudy of the YEFE phase 4 study was conducted at the Epicentre Mbarara Research Centre (Mbarara, Uganda). Eligible children were aged 9-59 months without contraindications for vaccination, without history of previous yellow fever vaccination or infection and not requiring yellow fever vaccination for travelling. Participants were randomly assigned, using block randomisation, 1:1 to standard or fractional (one-fifth) dose of yellow fever vaccine. Investigators, participants, and laboratory personnel were blinded to group allocation. Participants were followed for immunogenicity and safety at 10 days, 28 days, and 1 year after vaccination. The primary outcome was non-inferiority in seroconversion (-10 percentage point margin) 28 days after vaccination measured by 50% plaque reduction neutralisation test (PRNT50) in the per-protocol population. Safety and seroconversion at 10 days and 12-16 months after vaccination (given COVID-19 resctrictions) were secondary outcomes. This study is registered with ClinicalTrials.gov, NCT02991495. Between Feb 20, 2019, and Sept 9, 2019, 433 children were assessed, and 420 were randomly assigned to fractional dose (n=210) and to standard dose (n=210) 17D-213 vaccination. 28 days after vaccination, 202 (97%, 95% CI 95-99) of 207 participants in the fractional dose group and 191 (100%, 98-100) of 191 in the standard dose group seroconverted. The absolute difference in seroconversion between the study groups in the per-protocol population was -2 percentage points (95% CI -5 to 1). 154 (73%) of 210 participants in the fractional dose group and 168 (80%) of 210 in the standard dose group reported at least one adverse event 28 days after vaccination. At 10 days follow-up, seroconversion was lower in the fractional dose group than in the standard dose group. The most common adverse events were upper respiratory tract infections (n=221 [53%]), diarrhoea (n=68 [16%]), rhinorrhoea (n=49 [12%]), and conjunctivitis (n=28 [7%]). No difference was observed in incidence of adverse events and serious adverse events between study groups. Fractional doses of the 17D-213 vaccine were non-inferior to standard doses in inducing seroconversion 28 days after vaccination in children aged 9-59 months when assessed with PRNT50, but we found fewer children seroconverted at 10 days. The results support consideration of the use of fractional dose of yellow fever vaccines in WHO recommendations for outbreak response in the event of a yellow fever vaccine shortage to include children. Médecins Sans Frontières Foundation.

Research on a Novel Hybrid Power Supply Scheme with Energy Storage Technology for Tokamak

Megawatt-impulse power generated by Tokamak fusion devices seriously threats to the stable operation of the whole system. The current power supply scheme needs to leave large redundancy to suffer such a huge power impact, resulting in a high cost of the power supply system. Moreover, no reasonable configuration for impulse power and stable power causes unnecessary waste of power supply capacity. The rapid development of energy storage technology provides a potential approach to solve the operation stability problem caused by large amounts of power impact. Thus, a novel hybrid power supply scheme is creatively put forward with centralized energy storage, which can effectively decrease the voltage level of the grid and achieve smooth connection into the public grid when validly compensating for the impulse power. The cost evaluation model and principles are proposed to analyze and assess the economic advantages of the hybrid power supply scheme with centralized energy storage. Finally, a power scenario based on the international thermosnuclear experimental reactor (ITER) is applied as a case study of the cost evaluation model for various schemes, and the results verify that the novel hybrid power supply scheme has benefits on economics and the capacity of the grid over other schemes.

Analysis of Supermarket Supply Chain Management

Supply chain management is one of the main challenges in the development of the retail industry. As an important form of retail trade, supermarkets have attracted the attention of the whole retail industry. At present, large, medium, and small supermarkets are facing complete market competition, and each supermarket enterprise has more or less problems in its own supply chain relationship. The problem of how to solve the problems of various types of supermarket enterprises, improve their management programs, and win the market has become particularly important. Based on the existing literature and statistical data, this paper analyzes the problems existing in the supermarket retail industry in China, focusing on the deficiencies of the current supply chain and how to manage and optimize the supply chain. The result shows that the supply chain in domestic supermarkets still has a long way to improve. There are mainly five types of problems, which are supplier problems; delivery problems; location problems; display problems; and pricing problems. These kinds of problems might cause the loss of customer loyalty. The solution consists of three parts: diversifying the product supplier to ensure that the popular product never runs out; replacing the products shelf so that the customer can grab the popular product at first sight; and replacing the products shelf so that the customer can grab the popular product at first sight. Finally, be precise with the products pricing strategy; stress the price of the popular products and increase the profit for the unpopular ones.

Combined GPR and Self-Potential Techniques for Monitoring Steel Rebar Corrosion in Reinforced Concrete Structures: A Laboratory Study

Steel rebar corrosion is one of the main causes of the deterioration of engineering reinforced structures. Steel rebar in concrete is normally in a non-corroding, passive condition, but these conditions are not always achieved in practice, due to which corrosion of rebars takes place. This degradation has physical consequences, such as decreased ultimate strength and serviceability of engineering concrete structures. This work describes a laboratory test where GPR and SP geophysical techniques were used to detect and monitor the corrosion phenomena. The laboratory tests have been performed with several reinforced concrete samples. The concrete samples were partially submerged in water with a 5% sodium chloride (NaCl) solution. Therefore, an accelerated corrosion phenomenon has been produced by a direct current (DC) power supply along the rebar. The geophysical measurements were performed with a 2.0 GHz centre frequency GPR antenna along several parallel lines on the samples, always being the radar line perpendicular to the rebar axis. The GPR A-scan amplitude signals were elaborated with the Hilbert Transform approach, observing the envelope variations due to the progress of the steel rebar corrosion in each concrete sample. Moreover, Self-Potential acquisitions were carried out on the surface of the concrete sample at the beginning and end of the experiments. Each technique provided specific information, but a data integration method used in the operating system will further improve the overall quality of diagnosis. The collected data were used for an integrated detection approach useful to observe the corrosion evolution along the reinforcement bar. These first laboratory results highlight how the GPR should give a quantitative contribution to the deterioration of reinforced concrete structure.

Tutorial: Toward Robust Deep Learning against Poisoning Attacks

Deep Learning (DL) has been increasingly deployed in various real-world applications due to its unprecedented performance and automated capability of learning hidden representations. While DL can achieve high task performance, the training process of a DL model is both time- and resource-consuming. Therefore, current supply chains of the DL models assume the customers obtain pre-trained Deep Neural Networks (DNNs) from the third-party providers that have sufficient computing power. In the centralized setting, the model designer trains the DL model using the local dataset. However, the collected training data may contain erroneous or poisoned data points. The model designer might craft malicious training samples and inject a backdoor in the DL model distributed to the users. As a result, the user’s model will malfunction. In the federated learning setting, the cloud server aggregates local models trained on individual local datasets and updates the global model. In this scenario, the local client could poison the local training set and/or arbitrarily manipulate the local update. If the cloud server incorporates the malicious local gradients in model aggregation, the resulting global model will have degraded performance or backdoor behaviors. In this article, we present a comprehensive overview of contemporary data poisoning and model poisoning attacks against DL models in both centralized and federated learning scenarios. In addition, we review existing detection and defense techniques against various poisoning attacks.

A typology of supply chain resilience: recognising the multi-capability nature of proactive and reactive contexts

Even though resilience has received ample attention in recent literature, there is still a dearth of research when it comes to theorisation of supply chain resilience capabilities. Against this background, we aim to develop a framework for supply chain resilience capabilities based on proactive and reactive contexts. Apart from using ANOVA, we also perform a nuanced analysis using the response surface methodology. The analysis is done based on a survey dataset collected from 291 manufacturing firms. The results indicate that different combinations of proactive and reactive resilience capabilities can have a differential impact on the performance indicators. Although both proactive and reactive capabilities are essential for ultimate resilience strategies, supply chains might initially benefit more from reactive capabilities than proactive ones. The comprehensive framework proposed in our research addresses a vital gap in current supply chain resilience theorisation and could pave the way for further well-informed research on the evolving research domain. Moreover, this framework could serve as a powerful tool for supply chain managers to design and plan the development/improvement of resilience capabilities in collaboration with supply chain partners. They will be able to easily evaluate the current condition as well as targets for resilience capabilities.

Evaluation of Hydrogen Blend Stability in Low-Pressure Gas Distribution

Natural gas distribution companies are developing ambitious plans to decarbonize the services that they provide in an affordable manner and are accelerating plans for the strategic integration of renewable natural gas and the blending of green hydrogen produced by electrolysis, powered with renewable electricity being developed from large new commitments by states such as New York and Massachusetts. The demonstration and deployment of hydrogen blending have been proposed broadly at 20% of hydrogen by volume. The safe distribution of hydrogen blends in existing networks requires hydrogen blends to exhibit similar behavior as current supplies, which are also mixtures of several hydrocarbons and inert gases. There has been limited research on the properties of blended hydrogen in low-pressure natural gas distribution systems. Current natural gas mixtures are known to be sufficiently stable in terms of a lack of chemical reaction between constituents and to remain homogeneous through compression and distribution. Homogeneous mixtures are required, both to ensure safe operation of customer-owned equipment and for safety operations, such as leak detection. To evaluate the stability of mixtures of hydrogen and natural gas, National Grid experimentally tested a simulated distribution natural gas pipeline with blends containing hydrogen at up to 50% by volume. The pipeline was outfitted with ports to extract samples from the top and bottom of the pipe at intervals of 20 feet. Samples were analyzed for composition, and the effectiveness of odorant was also evaluated. The new results conclusively demonstrate that hydrogen gas mixtures do not significantly separate or react under typical distribution pipeline conditions and gas velocity profiles. In addition, the odorant retained its integrity in the blended gas during the experiments and demonstrated that it remains an effective method of leak detection.

Analisis Kebutuhan Layanan dan Fasilitas Eksisting Transportasi Ramah Lingkungan Dengan Kebutuhan Perjalanan (Studi Kasus: Pegawai di Lingkungan Pemerintah Kota Tanjungpinang)

State employees of Tanjungpinang consists of 4,303 people whose origins and destinations are spread throughout the city. This is the reason for the high travel demand where private vehicles are still superior to the other modes of choice. This adds to problems in environmental aspects, especially the contributors to air pollution and noise on the road. This study uses a quantitative method with descriptive analysis and spatial analysis. Descriptive analysis is used to identify existing employee travel characteristics. The graphic display presented in the results of the descriptive analysis aims to make it easier to explain the results of the analysis of the formation of zones, the number of trips in each zone, as well as the focus services and existing facilities. Spatial analysis is used to point to the edge of the location of existing facilities, and the ease of origin and destination of employee travel. The results of the study indicate that the current supply of services and facilities has not been able to accommodate the travel demand of state employees. The supply of transport services and facilities is still lacking because they only serve and available in several sub-districts which are the points of origin and destinations travel for employees. This caused low interest of employees by using green transport whose origin and destination areas are not covered and crossed by services. Therefore, it is necessary to request institutional-based travel demand management to encourage employees to travel using green transport in the form of policies, coordination, and cooperation within the internal scope of the Tanjungpinang city government.

Spatial Layout Analysis and Evaluation of Electric Vehicle Charging Infrastructure in Chongqing

This study considers the spatial analysis and evaluation layout of electric vehicle charging infrastructures, taking the central urban area of Chongqing as an example. Mathematical model analysis, ArcGIS spatial analysis, field investigation, questionnaire measurement, and hierarchical analysis methods are utilized to discuss the current distribution characteristics and supply–demand matching of the electric vehicle charging infrastructure in this region. The resulting data can provide references for the optimal layout of charging infrastructure. The main conclusions of this study are as follows: (1) The configuration and demand of charging infrastructure in the central urban area of Chongqing have obvious spatial differentiation and show strong centrality. (2) It is a common phenomenon that the charging infrastructure in the central urban area of Chongqing is in short supply, and it is pressing that a new charging infrastructure be built. (3) In the process of construction and operation of charging infrastructure, various factors, such as economy and traffic, should be comprehensively considered; at the same time, incidents of inefficient operation, such as being crowded out by nonelectric vehicles and unmaintained facility failure, should be minimized.

Agility assessment framework for modular and offsite construction

Purpose The purpose of this paper is to determine if companies in the modular and offsite construction (MOC) industry are agile or not and its level of application for agility principles, which allows for quick responses to the increasingly dynamic nature of industry environments. Design/methodology/approach This paper proposes an agility assessment framework for MOC that uses 48 assessment attributes organized into four categories: metrics, drivers, enablers and capabilities. A questionnaire approach was used to disseminate the framework globally in 19 countries and synthesize its relevance to the MOC industry. The questionnaire had 55 complete responses, majority of respondents work in managerial positions for MOC manufacturing facilities and onsite general contractors. Findings It was found that the lowest metric score for adapting to change was for cost since controlling cost would be difficult for any changes required after the design freeze stage. The top agility driver was found to be the need to respond to the wide variety of customer expectations, while the lowest driver was the existence of competing priorities. The top agility enabler was vendor partnership, which can be related to current postpandemic supply chain disruptions. Regarding technological capabilities, Europe and the USA acquired better scores compared to Asia, Latin America and Africa. Originality/value This study contributes to the MOC body of knowledge by creating an agility assessment tool for MOC firms to analyze their agile approach and environment, identifying the preliminary importance of agility assessment attributes and determining significant agile differences between the main MOC industry groups.

Time-variant magnetic field, voltage, and loss of no-insulation (NI) HTS magnet induced by dynamic resistance generation from external AC fields

High-temperature superconducting (HTS) coils serving as DC magnets can be operated under non-negligible AC fields, like in synchronous machines of maglev trains and wind turbines. In these conditions, dynamic resistance is generated in HTS tapes, causing redistribution/bypassing of the transport current inside the no-insulation (NI) coil and its unique operational features. This issue was studied by experiments on an NI coil with DC current supply put into external AC fields. Due to the current redistribution induced by dynamic resistance, the central magnetic field and voltage of the NI magnet initially undergo various transient processes, and eventually exhibit a stable central magnetic field reduction and a DC voltage. These time evolutions have implications for the time-varying torque and loss of an HTS machine. These time evolutions are strongly affected by the contact resistivity distribution, and whether it is the first time that the NI magnet has been exposed to the AC field, showing several qualitatively different waveforms (e.g. some are even non-monotonic with time). The magnitudes of the stable central field reductions, and their observed linear correlation with the DC voltages are found to be decided by the local contact resistivity of the innermost and outermost several turns. It is also noted that the non-insulated turn-to-turn contact help lessening the loss induced by the dynamic resistance. A numerical model is established to analyze/explain these experimental results by observing the microscopic current distribution. Two risks of quench are noticed: (i) the azimuthal current of the middle part turns increases as the AC field is applied; (ii) a concentration of radial current is observed near the terminals of the NI coil.