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This paper is born of the joy and pain of institutional life. It responds to recent work by Craig Thompson and is a response to an invitation to participate from the Editor of the JMM (Mark Tadajewski). It seeks to take seriously the role of consumer research and consumption within society. It seeks to tell 'better stories' about the past, present and what it sees as a reimagined future for consumer research. To do so, it revisits some of the canonical works of consumer research, such exemplary work it suggests are worthy of revisiting and critiquing if we are to chart a rejuvenated form of consumer research that takes seriously our contemporary predicament and is more critical and incisive in its intent. With renewed purpose it takes on board the insights around Bauman's notion of 'liquid times', offers a range of opportunities, possibilities and dangers around the conflicted consumer self and puts forward an ABC of critical consumer research, where notions of affect, breakdown, contradiction are taken seriously for their theoretical and practical insights. [ABSTRACT FROM AUTHOR]

Abstract\nIMPLICATIONS FOR REHABILITATIONNo tools or technologies exist to inform data-driven inspection schedules for wheelchairs. To develop such a schedule, this study identifies risk factors linked with manual wheelchair damage, part failures, and consequences and evaluates preferences for a new wheelchair servicing technology. A mixed methods study was performed with manual wheelchair users at The Ohio State University Martha Morehouse Clinic. Demographic data, wheelchair information, failure counts, and consequences suffered by the user were collected using surveys. Wheelchair usage was collected for a month using a sensor. A servicing smartphone app that connects with the sensor was demonstrated as a new servicing technology, and participant preferences were recorded. Thirty participants completed the survey testing procedures. Twenty-three collected usage data and eighteen collected it for over a week. At least 215 wheelchair part failures with an average of 13.4 ± 14.8 self-reported part failures and 4.7 ± 4.8 high-risk failures occurred in 12 months before the first study visit. Two weeks of collected data from 18 participants showed that normalised road shocks, age, and weight were associated with the condition of wheels and frames, as well as self-reported caster failures. Participants responded with a favourable preference for the new wheelchair servicing technology, with more than half of them interested in buying and using it. Risk factors like road shocks and user’s age and weight are associated with part damage towards failures and self-reported failures that risk injury. These factors can be modelled to develop and test the efficacy of wheelchair inspection schedules.Risk factors of sensor-recorded wheelchair usage and user demographic characteristics can be monitored to track wheelchair degradation and perform timely servicing.Collaboration among wheelchair users, caregivers, clinicians, technicians, and service providers is required to perform simple to complex tasks in wheelchair servicing.Healthcare plans and policies need to recognise the benefits of proactive wheelchair servicing and promote data as a tool for wheelchair servicing, preventing wheelchair part failures and consequences to the user.Risk factors of sensor-recorded wheelchair usage and user demographic characteristics can be monitored to track wheelchair degradation and perform timely servicing.Collaboration among wheelchair users, caregivers, clinicians, technicians, and service providers is required to perform simple to complex tasks in wheelchair servicing.Healthcare plans and policies need to recognise the benefits of proactive wheelchair servicing and promote data as a tool for wheelchair servicing, preventing wheelchair part failures and consequences to the user. [ABSTRACT FROM AUTHOR]

Copyright of Baghdad Science Journal is the property of Republic of Iraq Ministry of Higher Education & Scientific Research (MOHESR) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

To improve the dielectric strength in vacuum, spark conditioning through repetitive breakdowns by AC or impulse voltage is an effective method. AC conditioning at commercial power frequencies has been widely used due to its cost‐effectiveness, but the breakdown voltage after AC conditioning is generally lower compared to impulse conditioning. We have confirmed that multiple breakdowns occur successively in a half cycle of AC voltage application. It is considered that the multiple breakdowns are harmful for conditioning and triggered due to the previous breakdown in the same half cycle. In this paper, we discuss dielectric strength improvement by high frequency AC conditioning and how the multiple breakdowns are induced. We experimentally confirmed that the AC conditioning effect is improved by increasing the frequency of AC voltage for different applied AC conditioning voltages in a sphere‐plane electrode system. We focused on the breakdown position from the light emission images during AC conditioning to investigate whether the multiple breakdowns were induced or affected by the previous breakdown. We found that the multiple breakdowns occurred close to the previous breakdown position. The multiple breakdowns would be induced by the collision of metal particles due to the previous breakdown with the counter electrode. These breakdowns do not contribute to removing protrusion and would lead to damage to the electrode surface. The increasing frequency of AC conditioning would suppress the multiple breakdowns and improve the dielectric strength in vacuum. © 2024 The Author(s). IEEJ Transactions on Electrical and Electronic Engineering published by Institute of Electrical Engineers of Japan and Wiley Periodicals LLC. [ABSTRACT FROM AUTHOR]

The study is on the cost dynamics which is concerned with finite queues in particular to susceptibility to server outages, thresholddriven recovery and Catastrophic events, but main focus is on balking behaviour of the customers. A thorough investigation of the financial implications of interruptions and efficacy to recovery strategies is done and to alleviate the impact of breakdowns, disasters and customer refusals the queue system designs through empirical research is conducted. Various recovery policies have been compared with the existing thresholds, and the study further endeavors to categorize the cost-effective approach to mitigate the economic concerns of server failures and catastrophic incidents. The study brings discernments on the expected development in the management of the queuing system along with the assistance in complete decision-making in cost efficiency and enhancement of the complete system performance. [ABSTRACT FROM AUTHOR]

This paper presents findings from an online questionnaire that collected experiences from the Facebook outage on October 4th, 2021, an event that affected approximately three billion users around the globe. The purpose of the study is to contribute to recent discussions digital disconnection and digital wellbeing by using an extraordinary event of involuntary disconnection as point of departure. Our research questions were: Where were people when the services shut down, what did they think and what did they do? What correlations can be found between usage/attitudes to social media and the experiences of the outage? How can the outage of October 4th be understood as a snapshot of our cultural condition? The questionnaire was distributed to 463 Swedish university students and 191 responses were received. Our analysis shows how the involuntary disconnection caused by the outage was an event that highlights the ambivalence of digital life. It also points to some correlations between general social media use and attitudes, and the experiences and activities during the outage. The paper ends with a discussion on the implications that these findings may have for further research into digital disconnection. [ABSTRACT FROM AUTHOR]

The GaN photoconductive semiconductor switches (PCSSs) with low leakage current and large on-state current are suitable for several applications, including fast switching and high-power electromagnetic pulse equipment. This paper demonstrates a high-power GaN lateral PCSS device. An output peak current of 142.2 A is reached with an input voltage of 10.28 kV when the GaN lateral PCSS is intrinsically triggered. In addition, the method of retaining the AlGaN/GaN heterostructure between electrodes on PCSSs is proposed, which results in increasing the output peak current of the PCSS. The damage mechanism of the PCSS caused by a high electric field and high excitation laser energy is analyzed. The obtained results show that the high heat generated by the large current leads to the decomposition of GaN, and thus, the Ga forms a metal conductive path, resulting in the failure of the device. [ABSTRACT FROM AUTHOR]

Recurring bottlenecks significantly contribute to urban freeway congestion, making their analysis essential. This study examines six bottlenecks on Beijing’s Ring Road using multi-day data, identifying them via Dynamic Time Warping and Fuzzy C-Means Clustering (DTW+FCM). Key parameters—free-flow speed, critical speed, critical density, and jam density—are calibrated using fundamental diagram models. The Weibull distribution analyzes flow and speed patterns during congestion phases. The DTW+FCM method effectively identified bottlenecks and congestion levels. Severe congestion lasting over 10 hours on the West Second and Third Ring Roads averaged speeds of 15 km/h. The S3 model best fits data for the West Ring Roads, while the Van Aerde model suits the North Ring Roads. Different methods yield varying traffic capacity estimates, highlighting the need for nuanced approaches in urban expressway planning to maintain traffic quality and comfort. These findings offer valuable guidance for research and practical traffic management solutions. [ABSTRACT FROM AUTHOR]

The integration of self-assembled monolayers (SAM) into cobalt (Co)/porous low-dielectric-constant (low-k) dielectric interconnects is studied in terms of electrical characteristics and reliability in this work. Experimental results indicated that SAM derived from 3-aminopropyltrimethoxysilane (APTMS) improved breakdown field, time-dependent dielectric breakdown, and adhesion for Co/porous low-k integrated interconnects. However, the improvement magnitude was not large as compared to SAM in the Cu/porous low-k integration. Therefore, the integration of SAM into Co/porous low-k interconnects has a positive effect; however, in order to further promote the efficiency of SAM for Co/porous low-k interconnects, the option of precursors for the growth of SAM is required. [ABSTRACT FROM AUTHOR]

The study is on the cost dynamics which is concerned with finite queues in particular to susceptibility to server outages, threshold-driven recovery and Catastrophic events, but main focus is on balking behaviour of the customers. A thorough investigation of the financial implications of interruptions and efficacy to recovery strategies is done and to alleviate the impact of breakdowns, disasters and customer refusals the queue system designs through empirical research is conducted. Various recovery policies have been compared with the existing thresholds, and the study further endeavors to categorize the cost-effective approach to mitigate the economic concerns of server failures and catastrophic incidents. The study brings discernments on the expected development in the management of the queuing system along with the assistance in complete decision-making in cost efficiency and enhancement of the complete system performance.

As unmanned ground vehicles (UGV) continue to be adapted to new applications, an emerging area lacks proper guidance for global route optimization methodology. This area is surveillance. In autonomous surveillance applications, a UGV is equipped with a sensor that receives data within a specific range from the vehicle while it traverses the environment. In this paper, the ant colony optimization (ACO) algorithm was adapted to the UGV surveillance problem to solve for optimal paths within sub-areas. To do so, the problem was modeled as the covering salesman problem (CSP). This is one of the first applications using ACO to solve the CSP. Then, a genetic algorithm (GA) was used to schedule a fleet of UGVs to scan several sub-areas such that the total distance is minimized. Initially, these paths are infeasible because of the sharp turning angles. Thus, they are improved using two methods of path refinement (namely, the corner-cutting and Reeds–Shepp methods) such that the kinematic constraints of the vehicles are met. Several test case scenarios were developed for Goheung, South Korea, to validate the proposed methodology. The promising results presented in this article highlight the effectiveness of the proposed methodology for UGV surveillance applications. [ABSTRACT FROM AUTHOR]

Eastern filbert blight (EFB), caused by Anisogramma anomala, is the primary limiting factor for hazelnut (Corylus sp.) production in the United States. In this study, 82 cultivars and selections shown to be resistant or tolerant to EFB in Oregon were field planted in New Jersey in 2017 and 2019 and evaluated for their EFB response under high disease pressure. The trees carry known single resistance (R) genes with most mapped to their respective linkage groups (LG), including LG2, LG6, and LG7, or they express quantitative resistance (QR, horizontal resistance). Disease incidence and severity was documented, stem cankers counted and measured, and the proportion of diseased wood calculated. The EFB disease response of some cultivars/selections varied considerably between New Jersey and Oregon while others were consistent. Trends were observed in relation to resistance source origin and LGs, which provide insight into durability and usefulness of resistance. In striking contrast to Oregon, nearly all selections with R-genes mapped to LG6, including those carrying the ‘Gasaway’ resistance allele, exhibited severe EFB infections (232 of 266 [87%]). This finding is of consequence since the U.S. hazelnut industry currently relies solely on LG6 resistance for EFB resistance. Further, for the first time, EFB was observed on several selections carrying LG7 resistance, specifically offspring of ‘Ratoli’ from Spain. Interestingly, selections carrying LG7 resistance from origins other than ‘Ratoli’ remained free of EFB, with one exception, all selections carrying LG2 (n=9) resistance also remained free from EFB. Interestingly, the EFB responses of selections expressing QR (n=26) more closely resembled the disease phenotypes they exhibited in Oregon. Overall, the divergence in EFB response between Oregon and New Jersey, where pathogen populations differ, supports the presence of pathogenic variation in A. anomala and highlights potential limitations of using single R-genes to manage the disease. Results also suggest trees expressing QR may be more stable across pathogenic populations. [ABSTRACT FROM AUTHOR]

The breakdown and discharge ignition in discharge tubes with a diameter of about 1 cm and a length of 80 cm in inert gases (neon, argon, krypton, and xenon) at a pressure of about 1 Torr are studied experimentally. The tube is illuminated by radiation from continuous or pulsed light sources in the visible spectrum range. A ramp voltage with a small slope steepness (of about 50 V/s) is applied to the anode of the tube. Previously, the authors established that under these conditions external illumination can increase the breakdown voltage in several times. This effect was explained by the appearance of a charge on the tube wall as a result of photodesorption of electrons from its inner surface. In this work, it is found that charging the wall begins only when the anode potential approaches the breakdown potential measured without illumination. In addition, it is found that during the increase in the voltage on the anode and charging the wall, the anode potential differs from the breakdown potential by a constant and small value (less than 200 V). [ABSTRACT FROM AUTHOR]

Copyright of Electronic Components & Materials is the property of Electronic Components & Materials and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Polypropylene (PP) has recently been actively investigated as a potential power cable insulation substitute for crosslinked polyethylene (XLPE). This is mainly due to PP's higher thermal withstand capability over XLPE. Notably, PP has much higher stiffness than XLPE and therefore needs to be modified with tougher materials to reduce its overall stiffness while maintaining its desirable dielectric properties. To date, many investigations have been conducted on the mechanical and dielectric effects of PP blended with various copolymers. Nevertheless, systematic investigations on the dielectric effects of PP blended with ethylene‐based copolymers having different ethylene contents are less explored. The current work therefore reports on the impact of different ethylene contents of ethylene‐based copolymers on the breakdown performances of PP. The findings reveal that PP blended with a copolymer having a low ethylene content (68.7 wt%) results in at least 11% higher breakdown performance than PP containing a copolymer having a high ethylene content (77.0 wt%). Specifically, PP containing 10 wt% of copolymers having 68.7 wt% of ethylene content results in comparable breakdown performance to XLPE (325 kV mm−1). These results suggest that ethylene‐based copolymers with an appropriately low ethylene content can be blended with PP to achieve desirable breakdown properties. Highlights: PP is blended with copolymers of varying amounts and ethylene contents.PP blended with low amounts of copolymers has good breakdown strength.PP blended with low ethylene level copolymers has favorable breakdown strength.PP blended with copolymers of low ethylene contents is desirable.The breakdown mechanisms are related with the structure and permittivity. [ABSTRACT FROM AUTHOR]

Bion’s concept of catastrophic change and Winnicott’s descriptions of madness and breakdown indicate experiences of fear: generally, fear that, despite being resisted all one’s life, is nevertheless the prerequisite for change and psychic growth. Here, the author tries to understand this phenomenon in a case study in which the maintenance of timelessness as a defence against reality and the creation of inseparability were central to the analysis. An external catastrophe then reactivated an internal catastrophe, leaded to more difference, to surprise, and to the renunciation of timelessness. The text examines the relationship between internal and external catastrophic change and breakdown as well as the role of surprise. [ABSTRACT FROM AUTHOR]

Adoption can provide a lifetime of benefits for children. Some adoptions however, experience severe challenges resulting in disruption, with children leaving home prematurely. This qualitative study in Northern Ireland used interviews with parents from thirteen families whose adoptions had disrupted, to explore their perspective on the experience. Key findings focused on issues relating to firstly, the adopted child; secondly, adoption services; and finally, the parents and other family members. The impact of early adverse experiences on the children (developmental trauma) played out through behaviours, often violent, that their parents found extremely challenging. These increased as the children aged and had serious effects on family life. The adoptive parents thought they could have been better prepared through the adoption process to face challenging behaviours and more appropriately supported to prevent disruption. When their adopted child was admitted to state care, the parents typically felt initial relief but also guilt and loss. After the child had left home, they generally wished for more involvement with him or her despite the difficulties experienced. This study confirmed previous findings about the extent of trauma experienced by some adoptive children, and the challenges that this may present to the adoptive parents. It highlighted how the manifestation of the trauma experienced by the child may lead to adoptive parents themselves experiencing primary or secondary trauma or compassion fatigue (defined in the Discussion section below) or a combination of all three. The preparation of adoptive parents should include greater awareness of possible challenges, and how to cope with these. The development of trauma-informed approaches to practice and service delivery is required to support families with adopted children more effectively. Co-production models for service development may assist in addressing the types of issues identified in post-adoption support services. [ABSTRACT FROM AUTHOR]

We consider a single server queueing model with three service types, each with three phases, where customers arrive according to a Poisson process and the service time of each customer follows a Hyper-Erlang distribution. This study aims to analyze the impact of interruptions, such as breakdowns, repairs, and single working vacations, on the performance of the queueing system. The standby server activates whenever the main server experiences a breakdown. Using the matrix geometric method, we examine the steady-state probability vector of the model. Our results demonstrate the impact of these interruptions on system performance measures and provide a cost analysis. Finally, we present numerical examples to illustrate the practical applications of our findings in an image compression system. [ABSTRACT FROM AUTHOR]

We investigated a flat-type p*-p LED composed of a p*-electrode with a local breakdown conductive channel (LBCC) formed in the p-type electrode region by applying reverse bias. By locally connecting the p*-electrode to the n-type layer via an LBCC, a flat-type LED structure is applied that can replace the n-type electrode without a mesa-etching process. Flat-type p*-p LEDs, devoid of the mesa process, demonstrate outstanding characteristics, boasting comparable light output power to conventional mesa-type n-p LEDs at the same injection current. However, they incur higher operating voltages, attributed to the smaller size of the p* region used as the n-type electrode compared to conventional n-p LEDs. Therefore, despite having comparable external quantum efficiency stemming from similar light output, flat-type p*-p LEDs exhibit diminished wall-plug efficiency (WPE) and voltage efficiency (VE) owing to elevated operating voltages. To address this, our study aimed to mitigate the series resistance of flat-type p*-p LEDs by augmenting the number of LBCCs to enhance the contact area, thereby reducing overall resistance. This structure holds promise for elevating WPE and VE by aligning the operating voltage more closely with that of mesa-type n-p LEDs. Consequently, rectifying the issue of high operating voltages in planar p*-p LEDs enables the creation of efficient LEDs devoid of crystal defects resulting from mesa-etching processes. [ABSTRACT FROM AUTHOR]

A single server retrial fuzzy queuing model is presented in this study. An unreliable FM/FM/1 fuzzy retrial queue with a virtually unlimited retrial orbit and a standard queue is investigated. After an unspecified amount of time has elapsed and the server is workable and inactive, orbit patrons don't rejoin the regular queue, but instead, enter the server momentarily. Customers who arrive and discover the server is engaged or has struggled are placed in the regular queue, whereas customers who are disrupted are always placed in orbit. The model's prosecution proportions are also calculated in a hazy environment. The main goal of this investigation is to compare the efficacy of a single server retrial queuing system based on fuzzy queuing theory and intuitionistic fuzzy queuing theory. The arrival, service, failure, orbit, and repair rates are documented using triangular and triangular intuitionistic fuzzy numbers. The evaluation metrics for the fuzzy queuing theory model are proffered as a range of possible values, whereas the intuitionistic fuzzy queuing theory model encompasses a wide range of values. An approach is conducted to discover quality measures using a design protocol in which the fuzzy values are left alone and not repurposed to crisp values, allowing us to draw research findings in an ambiguous future. Two numerical problems are solved to emphasize the method's protracted survivability. [ABSTRACT FROM AUTHOR]

This review article presents an overview of bulk arrival and bulk service with breakdown QM's. The concept of bulk arrivals and bulk service has a new significance in the world of reality. To prevent the problem of traffic congestion, researchers must concentrate their efforts on developing models and processes to address the issue. Numerical methods of QM's are critical in many industries, notably in production lines, to alleviate traffic congestion. This study seeks to give analysts, researchers, and industry professionals enough information to model congestion problems and extract various performance indicators to improve the QS's. [ABSTRACT FROM AUTHOR]

A thorough understanding of arc discharge mechanism as well as determination of arc discharge voltage at the nanometer scale remains challenging due to the complexities associated with electrode preparation and precisely maintaining nanoscale separations in experiments. This work addresses this challenge through a novel approach by accurately measuring electric breakdown/discharge voltages between Pt-coated Si electrodes with separations ranging from ∼5 nm to 370 nm using a combination of fixed and flexible nano-electrodes while inherently creating an ideal environment to mitigate the effect of mechanical vibrations on the measurement results. For separations of 10, 100, and 300 nm, the corresponding discharge voltages are ∼15, 75, and 160 V, respectively, with the apparent electric field for the 10 nm separation exceeding 1.5 GV m−1. The results acquired from the investigated electrode configuration closely resembling the laterally actuated nanoelectromechanical system (NEMS) cantilever relays reveals strong agreement with NEMS relay breakdown characteristics, emphasizing the importance of arc discharge considerations while designing micro/nano electromechanical devices. Furthermore, deliberately applied arc discharge is shown to provide electrode nano-welding for realization of configurable NEMS circuits. [ABSTRACT FROM AUTHOR]

Electric motors are widely applied as electrical equipment that rotates at high speeds in high-temperature and high-voltage environments, with epoxy resin being the main material used to reinforce the structure of the motor. Taking epoxy resin as the research object in this work, comprehensive analysis was carried out to investigate its various physical properties. The frequency conversion dielectric performance of epoxy resin was tested and its perforation morphology was analyzed. The test results were used as corresponding parameters to establish a combined model of electrical and thermal breakdown for the reinforced structure. The dynamic performance, static mechanical performance, and stress relaxation performance of the epoxy resin at different temperatures were also tested, and a viscoelastic constitutive model of epoxy-reinforced structures was established and verified through stress relaxation tests. The research results of the breakdown and viscoelastic models can serve as a reference for the application of epoxy resin-reinforced structures. [ABSTRACT FROM AUTHOR]

We embarked on a comprehensive exploration of a single server queueing design, with a specific focus on handling soft failures. Soft failures refer to instances where customers do not need to be removed but rather need to wait for the server to be reactivated. These occurrences can happen at any time during the server's operation. When a soft failure occurs, the process automatically initiates a repair action, which we will refer to as the self-healing time. This self-healing time is relatively short, as the server possesses a remarkable restoration capability. Once the repair is complete, the server resumes its service provision and resumes normal operations. Moreover, during periods of prolonged idleness, the server can enter a dormant state, akin to a vacation mode. This dormant state is triggered when the server awaits the accumulation of N or more users. Once the threshold is reached, the server transitions into a busy state and resumes its normal operations. This study represents the pioneering integration of soft failures with the N policy, marking the first of its kind in this field. Additionally, we provide explicit expressions for the transient probabilities of the model, employing generating function methodology and Laplace transform techniques. Furthermore, we include performance measures and a numerical component to underscore the significance of the model's parameters.

Selim III, who ascended the Ottoman throne in 1789, began to take measures to restore power to the empire, which was then in a very difficult phase, and laid the foundations for the New Order, a reform process that encompassed the military, financial, administrative and economic spheres. Selim III, who ascended the throne after the Treaty of Kuchuk-Kainarji, one of the harshest treaties in the history of the Ottoman Empire, placed great importance on restoring the honour and prestige of the empire and the army, which had been immensely damaged by major defeats. The fact that Selim III wanted to promote the moral support of the soldiers and provide comprehensive care by embarking the army was seen as a result of this policy. As Selim III changed his decision on embarking the army for various reasons, he asked the ulama to help the army to progress in various areas and wanted them to fight with the other soldiers on the fronts. However, the fact that the ulama contradicted the Sultan and opposed the idea of fighting with the army at the front caused Selim III to change his attitude towards these soldiers, and this circumstance gave him the idea of carrying out some reforms in the ulama and even some comprehensive reforms in the Ilmiye in a hurry. This study aims at presenting the situation of the ilmiye, the institution in which the sultan targeted to make reforms, and making an analysis based on the crimes in which the institution was involved and the punishments of nefy (exile) which were inflicted on them [ABSTRACT FROM AUTHOR]

Experimental data are presented on the minimum values of energies and flux densities of electrons whose impact on the cover glasses of solar panels and reflecting elements of the thermoradiators of artificial Earth satellites produces electrostatic discharges. It is established that adding protons to the particle flux acting on the studied samples can suppress the development of discharges. A mathematical model is proposed for a qualitative interpretation of the obtained results. [ABSTRACT FROM AUTHOR]

Understanding the underlying factors responsible for higher-than-anticipated local field enhancements required to trigger vacuum breakdown on pristine metal surfaces is crucial for the development of devices capable of withstanding intense operational fields. In this study, we investigate the behavior of nominally flat copper electrode surfaces exposed to electric fields of hundreds of MV/m. Our novel approach considers curvature-driven diffusion processes to elucidate the formation of sharp breakdown precursors. To do so, we develop a mesoscale finite element model that accounts for driving forces arising from both electrostatic and surface-tension-induced contributions to the free energy. Our findings reveal a dual influence: surface tension tends to mitigate local curvature, while the electric field drives mass transport toward regions of high local field density. This phenomenon can trigger the growth of sharper protrusions, ultimately leading to a rapid enhancement of local fields and, consequently, to a runaway growth instability. We delineate supercritical and subcritical regimes across a range of initial surface roughness. Our numerical results are in qualitative agreement with experimentally reported data, indicating the potential practical relevance of field-driven diffusion in the formation of breakdown precursors. [ABSTRACT FROM AUTHOR]

During operation, the radio-frequency quadrupole (RFQ) of the LINAC4 at CERN is exposed to high electric fields, which can lead to vacuum breakdown. It is also subject to beam loss, which can cause surface modification, including blistering, which can result in reduced electric field holding and an increased breakdown rate. First, experiments to study the high-voltage conditioning process and electrical breakdown statistics have been conducted using pulsed highvoltage DC systems in order to identify materials with high electric field handling capability and robustness to low-energy irradiation. In this paper, we discuss the results obtained for the different materials tested. To complement these, an investigation of their metallurgical properties using advanced microscopic techniques was done to observe and characterize the different materials and to compare results before and after irradiation and breakdown testing. [ABSTRACT FROM AUTHOR]

Objective and method: Skin breakdown over receiver/stimulator (RS) after cochlear implantation poses a serious challenge. We report our experience using a one-stage reconstruction and implant salvage approach. Results: Between the years 2005 and 2017 five children, all females, with congenital- bilateral sensorineural hearing loss were identified. In all cases, a temporoparietal fascia flap (TPFF) and a large scalp flap were used to provide a two-layer coverage to the exposed RS. In the first three cases, a split-thickness skin graft was used to cover the donor site defect. In the latter two cases, a larger rotation flap was used, and a skin graft was not required. One case required revision due to the dehiscence of the wound and exposure of the RS. In another case, an accidental electrode array explantation occurred and the patient underwent a revision cochlear implantation. All patients had achieved complete healing and no change in hearing thresholds with the implants. Conclusions: We demonstrate our one-stage salvage technique with TPFF that saves the implant and prevents a two-stage procedure. The success rate can be improved with special care at reconstruction and with better protection of the implant during the procedure. [ABSTRACT FROM AUTHOR]

A quantitative model of the breakdown of MOS-structures with relatively thick (10–100 nm) gate dielectric by the mechanism of anode hydrogen release from interphase boundary Si-SiO2 is proposed. The breakdown delay time is determined by dispersion transport and accumulation of hydrogen ions in the gate dielectric. It is shown that at a high concentration of hydrogen in MOS structures and electric field strength of less than ~10 MV/cm, the model satisfactorily describes breakdown delay times significantly shorter than those expected from the 1/E model. At higher field strengths, the breakdown is described by the anode hole injection model. [ABSTRACT FROM AUTHOR]

In this study, we investigate a heterogeneous queueing model with intermittent server availability, server catastrophes, and a hybrid vacation policy. Our focus is on a specific scenario: server 1 is always available, while server 2 may experience breakdowns or vacations, making it intermittently accessible. Using the matrix-geometric approach (MGA), we derive matrix-based expressions for the stationary probability distribution of the number of customers in the system and various system performance measures. Additionally, we evaluate the cost function per unit of time to determine optimal values for the system's decision variables. Furthermore, we employ an adaptive neural fuzzy inference system (ANFIS) based on soft computing technology to compare and analyze the numerical results obtained. Through this comprehensive analysis, our study contributes to the understanding and optimization of this complex queueing system, attracting the attention of researchers in the field and offering practical insights for real-world applications. [ABSTRACT FROM AUTHOR]

In today's healthcare landscape, MRI (magnetic resonance imaging) plays a pivotal role in early diagnosis and treatment decisions. However, the quest for higher frequencies to achieve micron‐level resolutions poses technological challenges. This paper focuses on coils and capacitors, with special attention to air gap considerations for movable electrodes. The paper delves into the development of adjustable capacitors using high‐fired NP0 ceramic, tailored for 128‐MHz MRI systems. These capacitors boast impressive specs: a 3‐kV breakdown voltage (VBreakdown), a 3‐pF minimum capacitance (Cmin), a 30‐pF maximum capacitance (CMax), and a 1.5‐pF stepwise capacitance variation (Cvariation step). Notably, they enhance breakdown voltage while preserving frequency stability with MgTiCa ceramic between the fixed and mobile electrode, critical for adaptive blocks. Leveraging geometrical parameters analyzed through the ANSYS simulator, the authors meticulously designed an optimized 25–40 pF capacitor with a 15‐mm height and 1600 mm2 surface area. Post‐fabrication and sintering, extensive testing using a vector network analyzer across 10 MHz to 100 MHz validated performance against simulated expectations. [ABSTRACT FROM AUTHOR]

Eastern filbert blight (EFB), caused by Anisogramma anomala, is the primary limiting factor for hazelnut (Corylus sp.) production in the United States. In this study, 82 cultivars and selections shown to be resistant or tolerant to EFB in Oregon were field planted in New Jersey in 2017 and 2019 and evaluated for their EFB response under high disease pressure. The trees carry known single resistance (R) genes with most mapped to their respective linkage groups (LG), including LG2, LG6, and LG7, or they express quantitative resistance (QR, horizontal resistance). Disease incidence and severity was documented, stem cankers counted and measured, and the proportion of diseased wood calculated. The EFB disease response of some cultivars/selections varied considerably between New Jersey and Oregon while others were consistent. Trends were observed in relation to resistance source origin and LGs, which provide insight into durability and usefulness of resistance. In striking contrast to Oregon, nearly all selections with R-genes mapped to LG6, including those carrying the ‘Gasaway’ resistance allele, exhibited severe EFB infections (232 of 266 [87%]). This finding is of consequence since the U.S. hazelnut industry currently relies solely on LG6 resistance for EFB resistance. Further, for the first time, EFB was observed on several selections carrying LG7 resistance, specifically offspring of ‘Ratoli’ from Spain. Interestingly, selections carrying LG7 resistance from origins other than ‘Ratoli’ remained free of EFB, with one exception, all selections carrying LG2 (n=9) resistance also remained free from EFB. Interestingly, the EFB responses of selections expressing QR (n=26) more closely resembled the disease phenotypes they exhibited in Oregon. Overall, the divergence in EFB response between Oregon and New Jersey, where pathogen populations differ, supports the presence of pathogenic variation in A. anomala and highlights potential limitations of using single R-genes to manage the disease. Results also suggest trees expressing QR may be more stable across pathogenic populations.

Zhen Hao Ang,1,2 Shing Wai Wong1,2 1Department of General Surgery, Prince of Wales Hospital, Sydney, New South Wales, Australia; 2Randwick Campus, School of Clinical Medicine, The University of New South Wales, Sydney, New South Wales, AustraliaCorrespondence: Shing Wai Wong, Department of General Surgery, Prince of Wales Hospital, Edmund Blackett Building, Barker Street, Randwick, Sydney, New South Wales, 2031, Australia, Tel +61 2 93822894, Email sw.wong@unsw.edu.auAbstract: Despite vast improvements in training of colorectal surgeons and the care of patients undergoing colorectal resections, contemporary series still show an anastomotic leak rate of 1– 19%, which continues to contribute to the morbidity and mortality to these patients. New technologies and more recent studies investigating factors affecting the integrity of colorectal anastomosis have been published. Understanding the factors that increase the risk of anastomotic leak allows surgeons to take steps to prevent and ameliorate these risks. We aim to present an evidence-based narrative review relating anastomotic failure and an algorithm for early detection.Keywords: dehiscence, join, breakdown, risk

This research develops a simulation model, aiming to study the breakdown process of the tri-post insulator when exposed to electric field and mechanical loadings. The insulator is subjected to external forces of varying magnitudes and directions, along with an applied 1100 kV AC voltage. Results show that the breakdown process is driven by the electrostatic energy density (Wele) under an AC voltage. As the length of the breakdown channel increases, Wele, also rises, thereby accelerating the extension of the breakdown channel. After applying a straight tension along the insulator post, the tensile stress and the corresponding strain energy density become concentrated near the tips of the lateral branches, thus promoting their expansion and even causing a transverse fracture under the condition of 100 kN. In the case of a small straight compression below 25 kN, the breakdown process can be restrained. But when it comes to 75 kN, the breakdown process is promoted again, and a shear fracture can be caused above 100 kN. Under diagonal tensile or compressive stress, the breakdown channel deviates towards the applied force due to asymmetric strain energy density distribution. The objective of this research is to improve the comprehension and forecasting of breakdown in dielectric materials.

In this paper, a transfer learning technique was first utilized to obtain deep neural network models for different gate lengths in the avalanche breakdown regime. Once the characteristics of a gate-length metal-oxide-semiconductor field-effect transistor are measured and the data are used to obtain a deep neural network, behavioral models for different gate lengths are established by fewer hidden layers and less measured data at the desired biases and frequencies. Therefore, the training data through this method is significantly reduced and the accuracy of the testing dataset is comparable to that of the conventional artificial neural network technique. The predicted, measured, and simulated results based on the transit time theory at different bias voltages and frequencies are in good agreement. Multibias S-parameter behavioral models in the breakdown regime can be efficiently built using this technique. This approach can even be applied to other advanced technology nodes and can shorten the model building time for CMOS circuit design operating in the saturation and avalanche breakdown regions.

We consider a single server queueing model in which the customers arrive according to a Markovian Arrival Process (MAP). We modeled this queueing system with many kinds of service where the customers can choose any kind from the server. Each kind of service follows Phase-type (PH) distribution. We analyzed the model with breakdown, repair, single working vacation and standby server. A standby server works only when the main server is breakdown while serving the customer during a busy or vacation period. Using the matrix-geometric approach, we examined the model. A few real-world examples have been given, and several graphical and numerical examples have also been provided.

Operating conditions of film capacitors are complex, and the problem of film insulation failure caused by repetitively pulsed voltage is becoming ever serious. Degradation of the film under repetitively pulsed voltage cannot be accurately evaluated by the average breakdown electric field. In this paper, the effects of pulsed electric field and pulse repetition frequency on the breakdown in biaxially oriented polypropylene (BOPP) films are investigated. Three phases of BOPP degradation are proposed based on the voltage amplitude, i.e., maintenance (M), decline (D), and near-zero (N). Evolution of the BOPP film from degradation to breakdown at different frequencies is presented. Meanwhile, transition of discharge mode and elemental composition of the film are analyzed. Experimental results show continuous heat generation under repetitive microsecond pulses is the dominant factor for degradation of BOPP film. The number of applied pulses and the repetitive stressing time decrease exponentially with increase of frequency. This research can be contributed to the safe and reliable operation of capacitors.

Vertical extrinsic photoconductive semiconductor switches (PCSSs) are presented with initial characteristics comparison between V-doped 4H-SiC and Fe-doped GaN PCSS under axial triggering such as dark resistance, photoconductivity, power output, and breakdown behavior. Experiments are carried out under the 532-nm-wavelength laser with mJ-level energy and a pulse width of 30 ns. Photoconductive experiments show that the photoelectric conversion efficiency of GaN PCSS is 2.27 times higher than 4H-SiC PCSS with the same electric field strength under different laser energies from 1 mJ to 5 mJ. 4H-SiC PCSS with a dark-state resistance of $10^{12} \Omega \cdot $ cm can withstand a bias voltage of 8 kV (16 kV/mm) and laser energy of 8 mJ and the maximum output power is up to 428.7 kW, while that of GaN can only stand a bias voltage of 1 kV (2.9 kV/mm) because of low dark resistance and defect. Obvious cracks of 4H-SiC PCSS can be observed from the breakdown image after breakdown occurs, while the dark-state resistance of GaN PCSS drops from $10^{6} \Omega \cdot $ cm to $10^{4} \Omega \cdot $ cm under high DC voltage.

Fluoronitrile (C4F7N) has many advantages, such as high dielectric strength, low global warming potential (GWP), and short atmospheric lifetime compared to sulfur hexafluoride (SF6). C4F7N is mixed with carbon dioxide (CO2) to prevent liquefaction at the operating pressure of high-voltage power equipment. Therefore, it is essential to investigate the dielectric characteristics of the C4F7N/CO2 mixture gas for the development of environmentally friendly power equipment. The dielectric characteristics of C4F7N/CO2 at lower pressures have been previously reported. However, research into the breakdown characteristics of C4F7N/CO2 under high pressure environments is insufficient. Furthermore, the effect of oxygen (O2) content contributing to suppression of carbon soot formation by arc on breakdown characteristics of C4F7N/CO2 has rarely been investigated. Therefore, in this paper, the breakdown characteristics of C4F7N/CO2 according to the mixing ratio and O2 content were investigated while considering a high–pressure environment. The electrode arrangements were determined based on the field utilization factor in order to consider two types of electric field distribution. Alternating current (AC) and negative lightning impulse (-LI) breakdown tests were performed. From these experiments, under an extremely non-uniform electric field, it was confirmed that the dielectric strength of C4F7N 5%/CO2 95% at high pressure was about 75% of the strength of SF6. In a weakly non-uniform electric field, increasing the C4F7N content contributed to the improvement of dielectric strength by 31-77% relative to pure CO2 at the high pressure. Furthermore, it was investigated that the presence of O2 had no significant influence on improving the insulation performance.

Abstract Background Half of the sufferers of reversible cerebral vasoconstriction syndrome (RCVS) exhibit imaging-proven blood-brain barrier disruption. The pathogenesis of blood-brain barrier disruption in RCVS remains unclear and mechanism-specific intervention is lacking. We speculated that cerebrovascular dysregulation might be associated with blood-brain barrier disruption in RCVS. Hence, we aimed to evaluate whether the dynamic cerebral autoregulation is altered in patients with RCVS and could be associated with blood-brain barrier disruption. Methods A cross-sectional study was conducted from 2019 to 2021 at headache clinics of a national tertiary medical center. Dynamic cerebral autoregulation was evaluated in all participants. The capacity of the dynamic cerebral autoregulation to damp the systemic hemodynamic changes, i.e., phase shift and gain between the cerebral blood flow and blood pressure waveforms in the very-low- and low-frequency bands were calculated by transfer function analysis. The mean flow correlation index was also calculated. Patients with RCVS received 3-dimensional isotropic contrast-enhanced T2 fluid-attenuated inversion recovery imaging to visualize blood-brain barrier disruption. Results Forty-five patients with RCVS (41.9 ± 9.8 years old, 29 females) and 45 matched healthy controls (41.4 ± 12.5 years old, 29 females) completed the study. Nineteen of the patients had blood-brain barrier disruption. Compared to healthy controls, patients with RCVS had poorer dynamic cerebral autoregulation, indicated by higher gain in very-low-frequency band (left: 1.6 ± 0.7, p = 0.001; right: 1.5 ± 0.7, p = 0.003; healthy controls: 1.1 ± 0.4) and higher mean flow correlation index (left: 0.39 ± 0.20, p = 0.040; right: 0.40 ± 0.18, p = 0.017; healthy controls: 0.31 ± 0.17). Moreover, patients with RCVS with blood-brain barrier disruption had worse dynamic cerebral autoregulation, as compared to those without blood-brain barrier disruption, by having less phase shift in very-low- and low-frequency bands, and higher mean flow correlation index. Conclusions Dysfunctional dynamic cerebral autoregulation was observed in patients with RCVS, particularly in those with blood-brain barrier disruption. These findings suggest that impaired cerebral autoregulation plays a pivotal role in RCVS pathophysiology and may be relevant to complications associated with blood-brain barrier disruption by impaired capacity of maintaining stable cerebral blood flow under fluctuating blood pressure. Graphical Abstract

The GaN photoconductive semiconductor switches (PCSSs) with low leakage current and large on-state current are suitable for several applications, including fast switching and high-power electromagnetic pulse equipment. This paper demonstrates a high-power GaN lateral PCSS device. An output peak current of 142.2 A is reached with an input voltage of 10.28 kV when the GaN lateral PCSS is intrinsically triggered. In addition, the method of retaining the AlGaN/GaN heterostructure between electrodes on PCSSs is proposed, which results in increasing the output peak current of the PCSS. The damage mechanism of the PCSS caused by a high electric field and high excitation laser energy is analyzed. The obtained results show that the high heat generated by the large current leads to the decomposition of GaN, and thus, the Ga forms a metal conductive path, resulting in the failure of the device.