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Conventional Al-air battery has many disadvantages for miniwatt applications, such as the complex water management, bulky electrolyte storage and potential leakage hazard. Moreover, the self-corrosion of Al anode continues even when the electrolyte flow is stopped, leading to great Al waste. To tackle these issues, an innovative cotton-based aluminum-air battery is developed in this study. Instead of flowing alkaline solution, cotton substrate pre-deposited with solid alkaline is used, together with a small water reservoir to continuously wet the cotton and dissolve the alkaline in-situ. In this manner, the battery can be mechanically recharged by replacing the cotton substrate and refilling the water reservoir, while the thick aluminum anode can be reused for tens of times until complete consumption. The cotton substrate shows excellent ability for the storage and transportation of alkaline electrolyte, leading to a high peak power density of 73 mW cm−2 and a high specific energy of 930 mW h g−1. Moreover, the battery discharge capacity is found to be linear to the loading of pre-deposited alkaline, so that it can be precisely controlled according to the mission profile to avoid Al waste. Finally, a two-cell battery pack with common water reservoir is developed, which can provide a voltage of 2.7 V and a power output of 223.8 mW. With further scaling-up and stacking, this cotton-based Al-air battery system with low cost and high energy density is very promising for recharging miniwatt electronics in the outdoor environment.

In contemporary power plants, poor air temperature is one of the primary causes of rising unit temperatures and deteriorating boiler performance. The primary issue with an air preheater is air leakage on the gas flue side, which results in poor thermal performance. The high ash content of Indian coal exacerbates the issues with air tube heating. Air preheaters re developed to fulfill operational needs while taking into account the most important factors. Heat transmission, leakage, and pressure reduction are all factors to consider. The performance of the air-conditioning heater is being evaluated in this study using the Fluent 14.0 analytical tool from Computational Fluid Dynamics (CFD).

Battery power has been a popular choice of delivering DC power to many portable RF systems including wireless sensor nodes/internet of Everything (IoE). An autonomously powered RF system of the orders of 100’s of µwatts is becoming increasingly popular in recent times because of integrated solutions in energy harvesting. The minimum sensitivity of an RF energy harvester and the targeted deliverable output voltage for a specific load resistance are dictated by threshold voltage of transistors used and reverse leakage of such transistors. A detailed look into the architectures of rectifiers can help tackle design problems in the RF-DC conversion process. So in this work we focused on the design of integrated RF energy harvesting by studying four important architectures of RF-DC converters. To achieve a fair comparison between these architectures, a matching network operating at 0.8 MHz is designed and applied for simulation. All of these converters are tested in LT-SPICE XVII using the same designed matching network and the rectifiers are implemented in 180 nm CMOS technology.

We show that the most common flavors of noisy leakage can be simulated in the information-theoretic setting using a single query of bounded leakage, up to a small statistical simulation error and a slight loss in the leakage parameter. The latter holds true in particular for one of the most used noisy-leakage models, where the noisiness is measured using the conditional average min-entropy (Naor and Segev, CRYPTO'09 and SICOMP'12). Our reductions between noisy and bounded leakage are achieved in two steps. First, we put forward a new leakage model (dubbed the dense leakage model) and prove that dense leakage can be simulated in the information-theoretic setting using a single query of bounded leakage, up to small statistical distance. Second, we show that the most common noisy-leakage models fall within the class of dense leakage, with good parameters. Third, we prove lower bounds on the amount of bounded leakage required for simulation with sub-constant error, showing that our reductions are nearly optimal. In particular, our results imply that useful general simulation of noisy leakage based on statistical distance and mutual information is impossible. We also provide a complete picture of the relationships between different noisy-leakage models. Our result finds applications to leakage-resilient cryptography, where we are often able to lift security in the presence of bounded leakage to security in the presence of noisy leakage, both in the information-theoretic and in the computational setting. Remarkably, this lifting procedure makes only black-box use of the underlying schemes. Additionally, we show how to use lower bounds in communication complexity to prove that bounded-collusion protocols (Kumar, Meka, and Sahai, FOCS'19) for certain functions do not only require long transcripts, but also necessarily need to reveal enough information about the inputs.

Impedance-source inverters with coupled inductors can provide much higher voltage gains, but occasionally at the expense of discontinuous input currents and large voltage spikes at their dc-links. The former is caused by absence of inductances at their inputs, while the latter is due to unintentional interruptions of leakage currents through their coupled inductors. These problems have now been solved here by a new family of dual-winding impedance-source inverters (DW-ISIs). Each DW-ISI can recycle leakage energy from its two windings to a few clamping capacitors, which in turn help to prevent voltage spikes. This, together with the presence of an inductance for smoothing its input current, renders the family of DW-ISIs to be highly effective, while not compromising voltage and current stresses when compared to other precedent inverters. In addition, to simplify the circuit analysis, a reactive component elimination method has been proposed in this paper. Simulation and experimental results have confirmed the validity of the proposed topologies.

Experimental investigation has been performed to study the leakage and wear characteristics of carbon seal working at high circumferential speed. To expand the scope of application, two newly designed carbon seals were compared: #1 Carbon Seal (CS1) with the inner diameter of 136 mm and including 4 segments, #2 Carbon Seal (CS2) with the inner diameter of 212 mm and including 6 segments. Air leakage tests were firstly conducted in the Medium-speed Seal Test Rig. The pressure ratio changed from 1.04 to 2.02 with the rotating speed varying from 0 to 18300 r/min. Of paramount concern was the durability test, including 300 h running time accumulated by three different working conditions, which was separately implemented on each carbon seal. The morphology variation of the friction surface, wear and leakage were recorded. Results indicated that the leakage monotonously increases with the pressure ratio and decreases with the rotating speed. Comparing with CS1, more typical features exist on the friction surface of CS2, which are generated by more severe wear. Continually, leakage characteristics deteriorate. Furthermore, fitted formula has been educed for the life prediction of carbon seal, which could provide some supports for aero-engine design.

У роботі визначена актуальність моделювання методів та засобів технічного захисту акустичної інформації від витоку за допомогою розвинутих апаратно-програмних систем для розробки таких засобів захисту, їх вдосконалення та верифікації. Для цього запропонована кіберфізична система моделювання технічних засобів захисту акустичної інформації від витоку оптико-електронним каналом. В роботі проаналізовані та визначені характеристики і параметри елементів фізичної частини цієї системи, а також структура кібернетичної частини системи, функції та зміст моделей елементів фізичної частини. Метою роботи є розробка структури та визначення основних функцій елементів кіберфізичної системи для моделювання технічних засобів захисту акустичної інформації від витоку оптико-електронним каналом. Методологія вирішення поставленого завдання полягає у використанні методів системного аналізу та теорії керування для синтезу кіберфізичної системи моделювання технічних засобів захисту акустичної інформації від витоку оптико-електронним каналом, що забезпечує організацію вимірювально-обчислювальних процесів, зберігання та обмін вимірювальною і службовою інформацією, організацію та здійснення впливів на фізичні процеси. Наукова новизна. Вперше запропоновано будувати вимірювально-обчислювальні комплекси для дослідження методів та засобів захисту акустичної інформації від витоку оптико-електронним каналом у вигляді кіберфізичних систем, які поєднують фізичні процеси та кібернетичні компоненти в єдину систему, що дозволяє підвищити ефективність створення та вдосконалення засобів захисту та їх верифікацію. Висновки. Створення кіберфізичної системи моделювання методів та засобів технічного захисту акустичної інформації від витоку оптико-електронним каналом автоматизує вимірювально-обчислювальні процеси та підвищує спроможність розробки нових та вдосконалення існуючих засобів захисту, обґрунтування параметрів та характеристик їх елементів, а також верифікації засобів захисту.

Multiplexing circuits in pixelated PET detectors are being studied with the goal of minimizing the degradation of detector performance. The purpose of this study was to develop a diode-based symmetric charge division (SCD) circuit with reducing the crosstalk caused by the leakage currents of adjacent channels connected in rows and columns. Four different SCD circuits (diode-based SCD with grounding path, diode-based SCD, resistor-based SCD with grounding path and resistor-based SCD) were constructed and their performance was evaluated and compared after being combined with a PET detector consisting of LYSO crystals optically coupled with SiPM. The diode-based SCD circuit with grounding path achieved a crosstalk ratio, energy resolution, coincidence timing resolution (CTR) and mean peak to valley ratio of 0.02, 14.3%, 0.5 ns and 27.9: 1, respectively; the diode-based SCD circuit achieved 0.03, 15.9%, 0.7 ns and 19.4: 1, respectively; the resistor-based SCD circuit with grounding path achieved 0.04, 14.5%, 0.9 ns and 19.4: 1, respectively; the resistorbased SCD circuit achieved 0.05, 17.8%, 1.8 ns and 17.7: 1, respectively. These results indicate that the proposed SCD has the potential to improve not only the crosstalk but also the energy linearity, energy resolution, and coincidence timing resolution characteristics in PET detectors.

This paper reveals the flux leakage design and modeling principle of a flux leakage controllable permanent magnet (FLC-PM) machine by considering driving cycles. The key is to obtain the relationship between flux leakage characteristics and multiple operating conditions. Based on the flux leakage controllable concept, an FLC-PM machine with an artfully designed flux leakage region is proposed. The design principle of the machine is investigated by analyzing the magnetic circuit of the machine in multiple operating conditions. The flux leakage factor is introduced to characterize the variable magnetic field in multiple operating conditions. On this basis, the mathematical model of the FLC-PM machine is deduced, and the driving characteristics of the machine are studied in detail. In order to evaluate the presented principle of the FLC-PM machine, a prototype is manufactured for experiments. Through the theoretical analysis and experimental testing, it is verified that the proposed principle is feasible and effective.

This paper presents two topologies which provide high leakage inductance in shunt-inserted integrated magnetic transformers. These differ from conventional designs by replacing the low-permeability magnetic shunt of a planar transformer with high-permeability magnetic shunt segments, separated by many small air gaps. This approach results in a shunt with the same bulk permeability as the conventional design, while using lower cost and readily available magnetic materials such as ferrite. A modelling and design approach which can estimate the leakage and magnetising inductances precisely is provided for each topology. Theoretical analysis is presented and verified using finite-element analysis and experimental implementation. AC resistance analysis for both transformer topologies is also presented. In addition, an LLC resonant converter is built to verify the performance of the proposed fully-integrated magnetic transformers in practice. It is shown that the proposed topologies can integrate all three magnetic components of an isolated LLC resonant converter in a single planar transformer, which reduces the converters volume and cost.

During the manufacturing process of three-dimensions integrated circuits (3-D ICs), many defects may occur in through-silicon vias (TSVs). These defects affect integrity of the signal passing through TSVs, therefore detecting these defects in early production stage is crucial. This paper proposed a built-in-self-test (BIST) method with simple test structure and easily-implemented fault detection process. Due to the fact that the defects in TSVs influence the charge/discharge speed of TSVs’ equivalent capacitance, a weak current source is designed as the central part of the proposed test structure, which can measure the TSVs’ charge/discharge speed and quantify it using digital values. The effectiveness and robustness of the proposed method is validated by HSPICE simulation. The minimum measurable fault, test time and test circuit area are also assessed in this paper. The simulation results show that the method this paper proposed can detect weaker faults, compared with the traditional test methods.

Enhancing damping characteristic is one of the effective methods to solve the instability problem of the rotor system. The three-dimensional numerical analysis model of scallop damper seal was established, and the effects of inlet pressures, preswirl ratios, rotational speeds, interlaced angles and seal cavity depths on the rotordynamic characteristics of scallop damper seal were studied based on dynamic mesh method and multi-frequencies elliptic whirling model. Results show that the direct stiffness of the scallop damper seal increases with decreasing inlet pressure and increasing rotational speed and cavity depth. When the seal cavity is interlaced by a certain angle, which shows positive direct stiffness. The effective damping of the scallop damper seal increases with the increasing inlet pressure, the decreasing preswirl ratio and the rotational speed and cavity depth. There exists an optimal interlaced angle to maximize the effective damping and the system stability. The leakage of the scallop damper seal is significantly reduced with decreasing inlet pressure. The preswirl will reduce the leakage flowrate, and the rotational speed has a slight effect on the leakage performance. The leakage of the scallop damper seal decreases with increasing seal cavity depth.

A novel single-switch coupled-inductor switched-capacitor (CISC) high step-up converter is proposed which has a boost-type input structure allowing an improved input current ripple compared to other leading CISC converters. This is important for sustainable energy applications such as photovoltaic (PV) cells and fuel cells where high current ripple can degrade performance or lifetime. Though large input filters can be added between the energy source and the boost converter to smooth a pulsed converter input current, the proposed converter naturally has a more moderate current ripple, reducing the need for additional filtering. With regards to the coupled inductor, the leakage inductor energy is recycled without using an extra clamped circuit, and core utilization is high. The detailed theoretical operation is presented and an experimental prototype (200 W, 36 V to 48 V input, 400 V output) achieves a maximum efficiency of 97.1%.

The leakage inductance of medium-frequency transformers (MFTs) significantly affects the operation and efficiency of isolated converters, that are one of the most important components in solid state transformers, and should be accurately controlled or be minimized. This paper proposes a general analytical model of leakage inductance based on the superposition theorem and Rogowski coefficients, taking non-ideal geometric factors, such as the different heights of the primary and secondary winding in practical implementations, into account, with only less than 4% error compared to most 3D finite element simulations and 7% to all experiments. Based on the proposed model, an optimization scheme to minimize the leakage inductance for typical winding structures through adjustment of the winding arrangement is proposed and mathematically proved, which can reduce the leakage inductance by up to over 40% compared with the traditional concentrated arrangement, also validated in experiments. In addition, the optimization method does not need to redesign other magnetic parameters, basically free to use at no cost.

A dual-transformer-based enhanced dual active bridge (DAB) DC-DC converter for wide voltage range applications is introduced in this work. A power leg and transformer of the conventional DAB converter are split in two parts, leading to an expansion of the control freedom. Its wide voltage operating range does not rely on the small leakage inductor design and high transformer turns ratio. The root mean square value of the leakage inductor current is optimized with the ensuring of full domain zero voltage switching. The conduction losses and switching losses can be significantly reduced in Buck Mode compared to conventional DAB converter. A simple segment control strategy with four control degrees of freedom is employed to avoid inrush from mode switching. The analysis and control processes are simplified, and the control loop is a simple closed voltage loop without the need for look-up table checking. The discussed converter and control strategy are verified by a 1.0 kW prototype.

Purpose: Anastomotic leakage, a known major postoperative complication, potentially leads to readmission, reoperation, and increased mortality rates in patients, such as rectal cancer patients following a low anterior resection (LAR). Currently, vacuum-assisted closure, as featured by B-Braun (B-Braun Medical B.V.), is already being used for the treatment of gastrointestinal leakages and fistulas. The main aim of this study was to introduce a novel method for creating a vacuum-assisted drain for the treatment of anastomotic leakage after LAR.Methods: All 10 patients, who underwent LAR surgery from 2018 to 2019, were diagnosed with anastomotic leakage and had received neoadjuvant chemotherapy prior to surgery. Therefore, patients were treated with a handmade vacuum-assisted drain and were revisited every 5 to 7 days for further evaluations and drain replacement until leakage resolution. Physical features of cavity, time of diagnose, and duration of treatment were analyzed correspondingly. The handmade vacuum-assisted sponge drain was prepared for each patient in each session of follow-up.Results: Eight out of 10 patients experienced complete closure of the defect. The mean delay time from the day of operation to the diagnosis of anastomotic leakage was 61.0±80.4 days while the mean time for leakage closure was 117.6±68.3 days. Eventually, 7 cases underwent ileostomy reversal with no complications during a 3-month follow-up.Conclusion: In this study, we evaluated the healing process of anastomotic leakage after the usage of a handmade vacuum-assisted sponge drain in a case series method. In our trial, we provided an innovative cost-benefit method easily applicable in the operating room.

With the continuous development of deep oil and gas, minerals, geothermal resources, and other resources, there are increasingly more stringent requirements for equipment. In particular, the ultra-high-pressure dynamic seals of deep mining device need to be developed. Therefore, considering the use of dynamic seals in unique deep mining environments, an ultra-high-pressure rotating combined dynamic seal was designed and developed and its sealing performance was experimentally measured and analyzed. The results show that the experimental device can operate stably under a pressure of up to 150 MPa and a rotating speed of 76 r/min, and can also operate normally under a rotating speed of up to 140 r/min and a sealing pressure of 120 MPa. During the operation of the ultra-high-pressure rotating combined dynamic seal, the sealing ring does not show obvious damage, which vouches for its sealing performance. No leakage of flow and pressure was detected in the all seal structures within the sealing pressure range of 0∼150 MPa. Therefore, the dynamic sealing performance of the device is intact under ultra-high-pressure conditions and can be applied in deep mining environments at a certain depth. The research and development of this device can aid future deep energy exploration and exploitation.

Various structural defects deteriorate tunnel operation status and threaten public safety. Current tunnel inspection methods face problems of low efficiency, high equipment expense, and difficult data management. Combining the deep learning model and the 3D reconstruction method based on structure from motion (SfM), this paper proposes a novel SfM-Deep learning method for tunnel inspection. The high-quality 3D tunnel model is constructed by using images taken every 1 m along the longitudinal direction. The instance segmentation of leakage in longitudinal images is realized using the mask region-based convolutional neural network deep learning model. The SfM-Deep learning method projects the texture of the images after defect recognition to the 3D model and realizes the visualization of leakage defects. By projecting the model to the design cylindrical surface and expanding it, the tunnel leakage area is quantified. Through its practical application in a Shanghai metro shield tunnel, the reliability of the proposed method was verified. The novel SfM-Deep learning method can help engineers efficiently carry out intelligent tunnel detection.

The electro-hydrostatic actuator (EHA) used in more electric aircraft (MEA) has been extensively studied due to its advantages of high reliability and high integration. However, this high integration results in a small heat dissipation area, leading to high-temperature problems. Generally, to reduce the temperature, a wet cooling method of using the pump leakage oil to cool the motor is adopted, which can also increase the difficulty of accurately predicting the system temperature in the early design stage. To solve this problem, a dynamic coupling thermal model of a wet EHA is proposed in this paper. In particular, the leakage oil of the pump is used as a coupling item between the electrical system and the hydraulic system. Then, an improved T-equivalent block model is proposed to address the uneven distribution of axial oil temperature inside the motor, and the control node method is applied to hydraulic system thermal modeling. Meanwhile, a dynamic coupling thermal model is developed that enables a dynamic evaluation of the wet EHA temperature. Then, experimental prototypes of wet motor and wet EHA are developed, while the temperature response of the wet motor at different rotation speeds and different loads and the temperature response of the wet EHA at no-load condition were verified experimentally at room temperature, respectively. The maximum temperature difference between the experimental and theoretical results of the wet motor as well as the experimental and theoretical results of the wet EHA is less than 8 °C. These test results indicate that the dynamic coupling thermal model is valid and demonstrate that the thermal coupling modeling method proposed in this paper can provide a basis for the detailed thermal design of EHA.

Rock bolts are commonly used to stabilise slopes and underground excavations but their installation can sometimes be difficult in challenging grounds due to excessive leakage or washout of the grout. To manage these problems, tubular geotextile socks have been adopted in the industry but there has been a lack of research on their properties. To advance the understanding of sock behaviour, the water permittivity and filtration properties of two types of grout sock have been investigated in their unstretched state. From the permittivity tests, it is shown that water flow through these socks will be laminar and that using more than one layer in a setup can effectively reduce the flow velocity. Moreover, it has been shown that the effect of the tester should be considered in the analysis or else the permittivity of the geotextile could be underestimated. From the filtration tests, it is shown that both types of grout sock tested are effective in minimising grout loss and that the permittivity of the filter cake will be many orders of magnitude lower than that of the socks. The results also show that the water–cement ratio of the grout will be reduced as a result of the dewatering process.

As an extreme manifestation of environmental degradation, karst rock desertification is caused by soil loss and rock exposure. In some areas with serious rocky desertification, there is no soil to be eroded or leaked. The soil loss in these areas superimposes soil erosion and unique subsurface loss by soil leakage through fissures, pipelines, sinkholes, etc., which directly reduce soil resources and accelerate rocky desertification. However, the factors driving soil erosion and subsurface loss by soil leakage are still unclear. Rainfall experiments were conducted on simulated slopes with surface-exposed bedrock and subsurface fissures based on field investigations in a karst rocky desertification area of Guizhou Province, China. Four factors, including rainfall intensity, slope gradient, bedrock exposure rate and subsurface fissure degree, were considered in the experiment. We found that the amount of soil surface erosion and subsurface leakage loss is driven not only by the runoff volume but also by other influential factors. Rainfall intensity is the driving factor determining the amount of surface erosion and subsurface leakage loss of soil and water and the relationship between them. The slope gradient plays a leading role only in subsurface fissure flow leakage loss. The bedrock exposure rate drives the surface soil erosion rate, shows a critical value (30%), and dominates the fissure flow leakage loss rate. Subsurface fissure density plays an important role in the surface loss of soil and water; however, an increase in the subsurface fissure density does not obviously accelerate the subsurface leakage loss of soil and water. Although this result, obtained from laboratory simulations, may differ at the field scale or larger, it could provide a foundation for systematic studies on soil erosion/leakage and insights into the relations between rocky desertification and soil erosion/leakage and their driving factors in karst rocky desertification.

Liquid leakage can cause industrial accidents. Current liquid leakage detection methods judge the leakage state by analyzing signals from special intrusion sensors, which is not ideal for early leakage due to sensor limited sensitivity. Visual information from surveillance systems deployed in industrial environments can reflect early leakage that cannot be monitored by such pressure sensors. In this paper, we propose a visual early leakage detection system based on a visual background extractor (Vibe) and EfficientNetB0. First, we extract the translucent and small potential leakage candidates based on Vibe, which include leakage targets and environmental interference. Then, to further recognize leakage targets in potential leakage candidates, we explore CNN models and a few recently proposed methods, and compare them with two different evaluation criteria. Our model based on EfficientNetB0 performs best and achieves 99.526% accuracy. Additionally, our CNN model for leakage recognition with a smaller size is feasible for industrial application. Experiments are conducted on the leakage dataset from surveillance video from the Tianjin Binhai Heating Station, and the detection results are consistent with real leakage situations. Our leakage detection system has high sensitivity and accuracy, which meets the requirements of early leakage detection.

Profiling side-channel attacks in which an adversary creates a “profile” of a sensitive device and uses such profile to model a target device with similar implementation has received the lion’s share of attention in the recent years. In particular, template attacks are known to be the most powerful profiling side-channel attacks from an information theoretic point of view. When launching such attack, the adversary first builds a model based on the leakage of the profiling (training) device in his disposal which is then exploited in the second phase of the attack (i.e., matching) to extract the key from the target device. Discrepancies between the device used for modeling and the target device affect the attack success. The effect of process variation and temperature misalignment between the profiling and target devices in the template attack’s success has been studied extensively in literature, while the impact of device aging on the template attack’s success is yet to be investigated thoroughly. This paper moves one step forward and studies the impact of device aging, mainly Bias temperature Instability (BTI) and Hot Carrier Injection (HCI), in the devices that have been protected against power analysis attacks via dual rail logics. In particular, we focus on the Wave Dynamic Differential Logic (WDDL) circuits, and via extensive transistor-level simulations we will show how device aging misalignments between the profiling and target devices can hinder template attacks for both unprotected and WDDL protected counterparts. We mounted several attacks on the PRESENT cipher, with and without WDDL protection, at different temperatures and aging times. Our results shows that the attack is more difficult if there is an aging-duration mismatch between the training and target devices, and the attack-efficiency decrease is especially significant for mismatches of few weeks.

Running applications on a rooting device makes the application vulnerable to data leakage. Therefore, many applications that require a high level of security are not allowed to run on rooted device. Common technique of detecting rooted device is by using Android API to discover rooting trace. However, the detection can be bypassed using Java function hooking script by the people who want to run the app on rooted device. This research will give illustration that the bypassing process becomes more easy with automation tool and hybrid analysis. In order to create the script, we use combination of static and dynamic analysis with three phases with specific function. Phase 1 aims to detect the estimated Java method that detect rooting, phase 2 will analyze that method on an unrooted device, then phase 3 will create the bypassing script based on the previous result. We also use automation tool to speed up the static analysis. We create two types of script: one that can be used on general application, and the other one that only can be used on specific app. Those types implement different scope: one with the certain Java method, and the other one with specific parameter or return value. In the end, we find that bypassing rooting detection is not complicated if the app use Java function to detect the rooted device. To complicate bypassing process, we encourage the developers to implement more advanced detection rooting technique.

Order-preserving encryption (OPE) is a cryptographic primitive that preserves the order of plaintexts. In the past few years, many OPE schemes have been studied to solve the problem of executing range queries in encrypted databases. However, OPE allows certain information to be leaked (for example, the order of ciphertext), so it is vulnerable to many attacks. Subsequently, order-revealing encryption (ORE), as a generalization of order-preserving encryption, breaks through the limitation of the numeric order of OPE plaintext. It implements ciphertext comparison for any specific form of plaintext through a publicly computable comparison function. In this work, we aim to design the new ORE scheme which reduces the leakage and preserves the practicality in terms of ciphertext length and encryption time. We first propose the hybrid model named HybridORE. Then, we propose an improved scheme named EncodeORE which achieves acceptable security and appropriate ciphertext length. They both explore the encode strategy of encoding plaintext into different parts and apply suitable ORE algorithms to each part according to its security characteristics to reduce leakage. Compared with the typical schemes in large domain, they have less leakage. The experiment shows that the proposed EncodeORE is very practical.

A novel zero voltage switching (ZVS) interleaved high step-up converter with for renewable energy systems is proposed in this paper. By applying a switched capacitor mixed with coupled inductor and built-in transformer, the proposed converter achieves high voltage gain and minimized voltage stress across power switches. Both of the voltage gain and the voltage stress, can be adjusted by the turns ratio of the coupled inductor and built-in transformer which gives an extra degree of freedom for the converter design. Hence operating at high duty cycles is avoided and low voltage rated semiconductors can be adopted which reduce conduction losses and improve the circuit performance. Furthermore, active clamp scheme is utilized to guarantee ZVS turn ON for the power MOSFETs and the leakage inductances of the magnetic means help to provide zero current switching (ZCS) of the diodes. In such a case, switching losses are minimized and the reverse current recovery is alleviated. Accordingly, the proposed converter with reduced counterparts is a suitable candidate for high step-up and high power applications. Finally, a 600W prototype with 24V-480V voltage conversion is built to demonstrate the performance of the proposed converter.

Leakage is the main concern in steel bolted liquid tanks and past experience has indicated serviceability problems due to leakage, mainly from the joint locations, even in situations where the tank has only been subjected to an internal hydrostatic pressure. In this study, the performance of this type of construction was investigated using a detailed finite element (FE) analysis technique. Moreover, the validity of the American Water Works Association design practice in terms of the safe design of this type of structure at a wide range of service loads is evaluated through a parametric study. The FE analysis was performed in two stages using shell and solid elements in a three-dimensional ANSYS environment including the effect of geometric nonlinearity. The proposed FE model could estimating the behaviors such as capacity curve, yield/failure pattern, and the occurrence of ovalling and curling in bolted connections. In addition, the FE results were compared with experimental ones and found to be generally in good agreement. This study shows that a bolt arrangement chosen by design can efficiently improve the joint performance. Further, the use of a limited deformation criterion in the leak-resistant design of bolted lap joints in steel liquid containers is recommended.

In this paper, a buck based active-clamp circuit for current-fed isolated DC-DC converters is proposed. The proposed active-clamp circuit can not only suppress the voltage spikes caused by the current difference between the current-fed inductor and leakage inductor of the transformer, but also transfer the energy of the above process to the input voltage source. Different from the traditional active-clamp circuit, the proposed active-clamp circuit needs only one switch regardless of the number of input phases in the main circuit. Moreover, the control of the proposed active-clamp circuit is decoupled with the main circuit, which makes the design and implementation of the system controller easier. A 400W experimental prototype has been built to verify the effectiveness of the proposed circuit.

This communication presents a compact end-fire leaky wave antenna (LWA) is presented on the coplanar stripline (CPS) with narrow width property under a new operation mechanism. By periodically loading stubs between two strip lines in parallel, the leaky region of its fundamental mode can be generated in the CPS with forward beam scanning property, and the end-fire radiation is realized at the frequency where its normalized phase constant is equal to one. Since the leaky region of the fundamental mode owns a relatively low cutoff frequency, the proposed antenna generally has the property of small overall size in this region. The end-fire operating frequency is firstly discussed based on the circuit model, and the corresponding radiation property is then analyzed from the antenna array point of view. The leakage constant as well as characteristic impedance of the proposed antenna are further investigated with the full-wave extraction method. Moreover, a modified structure is proposed as the last element of the antenna to leak out the rest of the energy at its end. Finally, a CPS leaky-wave prototype antenna is designed and fabricated, where the measured results show good agreement with the simulated ones and thus validate the predicted performances.

In this communication, we propose glide-symmetric double-layer spoof surface plasmon polaritons (SSPPs) structures for controlling the field confinement of SSPPs to achieve antenna beam manipulation with a large frequency-scanning angle. By changing the shape of the glide-symmetric double-layer SSPPs, we can control the electric field confinement of the SSPPs to emerge symmetric or asymmetric distribution. Hence, the proposed SSPPs structure can produce electromagnetic leakage on both sides or single side, furtherly achieving dual-beam or single-beam radiation. Two SSPPs antennas with dual beams and single beam are designed, fabricated, and measured. Both the dual-beam antenna and single-beam antenna operate from 9 GHz to 24 GHz. Within the working band, the dual-beam antenna accomplishes 134.3° (-90° to +44.3°) beam-scanning angle with the realized gain of 8.03-12.17 dBi, while the single-beam antenna achieves 119° (-77.9° to 41.1°) beam-scanning angle with 10.31-14.24 dBi realized gain. The simulated and experimental results verified the beam manipulation and large frequency-scanning angle in antenna design.

Silicon-based optical media present several desirable properties for a wide range of applications. Herein, we propose a novel hybrid integration scheme that combines a silicon photonics platform and a 5.5%--silica planar-lightwave circuit (PLC) platform. By exploiting the performance advantages of each platform, we fabricated a polarization-insensitive low-crosstalk 8 8 silicon photonics switch butt-jointed with a compact 5.5%--silica PLC-based 100-GHz 8-channel arrayed waveguide grating (AWG). The device was driven by a smartphone-sized (9 cm 13.5 cm) control board. The fabricated device exhibits a fiber-to-fiber insertion loss of 12.6 dB, an average polarization-dependent loss of less than 0.57 dB, and less than -40 dB leakage to non-target output ports. We also demonstrate two uses of the proposed device. The first is the DEMUX and Switch operation, in which the spectrally divided light by the AWG is routed to an arbitrary output port by a subsequent switch. The second is the Switch and MUX operation, in which arbitrary wavelengths from arbitrary input ports are merged by the AWG. No spectral degradation was observed in either operation. These results demonstrate the potential of the 5.5%--PLC/silicon photonics hybrid platform for compact, low-power, and fast-switching applications.

Several techniques are proposed in the literature to improve the cross-regulation performance of a multiple output flyback converter (MOFC). However, some drawbacks exist: 1) inability to completely eliminate cross-regulation, 2) reduction of power density due to a high number of additional components, 3) increased losses. To overcome these challenges, this paper presents a scheme to independently control the outputs of an MOFC, thereby achieving excellent cross-regulation performance over a wide range of loads, without any additional switching or magnetic component. The unique gate dependent reverse conduction characteristics of gallium nitride (GaN) high electron mobility transistor (HEMT) is utilized to control the flow of current to each of the output capacitors. The operational principle and the steady-state analysis is provided in detail. Moreover, design considerations such as the switching frequency, GaN gate bias, leakage inductances, output capacitance etc. are discussed, focusing on their impacts on the key design goals, particularly the efficiency, power density, and output voltage ripple. Furthermore, SPICE simulations are used to demonstrate the improvement in cross-regulation over existing schemes. Finally, a 40 W dual output laboratory prototype is built to verify the analysis. The measured maximum cross-regulation is 0.2% which validates the effectiveness of the scheme.

Experiments are conducted to quantify leakage through a circular geomembrane (GMB) hole using two subgrades (underliners) not meeting modern filter criteria. Test results show that a 1.9- and 5.0-fold increase in hole diameter causes a 1.8- and 6.2-fold increase in leakage, respectively, whereas a 2-fold increase in GMB thickness results in an approximate 10% decrease in leakage. For a constant hydrostatic effective stress, a 2- and 3-fold increase in water head above the GMB leads to a 1.8- and 2.5-fold increase in leakage, respectively. Higher leakage arising from the intrusion of subgrade materials through the hole is quantified. A numerical model, considering the localized concentration of head loss around the hole and the consequent heterogeneity in hydraulic conductivity due to the seepage force, is presented. The percent of head loss within the hole and from the hole to any position above the GMB is independent of loading conditions and only influenced by the GMB thickness and hole diameter. Finally, empirical equations for predicting leakage through a circular GMB hole in tailings storage applications are proposed. Compared with published equations that do not consider consolidation induced heterogeneity in hydraulic conductivity, the proposed equation (which does consider these factors) gives a more accurate prediction for the cases examined.

This paper discusses electrical design optimization of a 3.3 kW, 380 V to 250-380 V, 500 kHz, dual-active-bridge dc-dc converter for on-board chargers, operated with constant-power (CP) charging. In order to operate the converter at 500 kHz without concerns on switching performance and efficiency while also improving power-density, a low-parasitics, PCB-based, wire-bondless full-bridge module featuring bare-die SiC MOSFETs and compact, electro-thermally multi-functional coolers is employed. High switching frequency operation also felicitates realization of the DAB inductor using the transformer’s leakage inductance, thereby enhancing power-density by eliminating the need for a discrete inductor. Design strategy for such magnetic integration in a planar transformer is discussed followed by a systematic design optimization of the transformer, including selection of leakage inductance value, core geometry and number of turns for achieving zero-voltage-switching (ZVS) and maximum average efficiency over the entire charging profile. Experimental validation was performed using a proof-of-concept prototype, which is operated up to 3.3 kW and has a final projected power density of 5.44 kW/L. Results demonstrate operation with ZVS over the entire charging profile with satisfactory high-frequency waveforms and a peak efficiency of 98%.

Flexible quasi-solid zinc-ion batteries (ZIBs) have large potential in power applications due to the low price, wearable nature, safety, and high capacity. However, the use of transition metal sulfide cathodes in ZIBs has not been studied extensively and the underlying mechanism and theoretical basis of this type of batteries are not well understood. Herein, a highly active cobalt-doped Ni3S2 porous nanocone framework (C12NS) is designed and demonstrated as a zinc-ion battery electrode. First-principles calculation and experiments reveal that the cobalt dopant improves the battery properties greatly. The assembled flexible zinc-ion battery exhibits a high specific capacity of 453.3 mAh g−1 at a current density of 0.4 A g−1 in as well as excellent cycling stability as manifested by a capacity retention ratio of 89.5% at a current density of 4 A g−1 after 5000 cycles. The peak energy density of 553.9 Wh kg−1 is also superior to those of most recently reported NiCo-based zinc-ion batteries. More importantly, the flexible battery can be operated under severe mechanical bending and even continues to work after physical puncturing without showing leakage. These exciting results not only reveal a novel design of cathode materials for zinc-based batteries, but also suggest their immense commercial potential in portable and wearable electronics.

A real-time and molecule-level monitoring of the interfacial dynamic interactions between molecules and a cell membrane is of vital importance. Herein, taking TAT, one of the most representative cell penetrating peptides, as an example, a photo-voltage transient technique and a dynamic giant bistratal vesicle (GBV) leakage method were combined with the traditional giant unilamellar vesicle (GUV) leakage assays, to provide a molecule-level understanding of the dynamic membrane interaction process performed in a low ionic strength and neutral pH condition. The photo-voltage test based on supported phospholipid bilayers showed a quick disturbance (1 min) followed by a continuous reconstruction of the membrane by peptides, leading to a slight destruction (at TAT concentrations lower than 1 μg mL

An ultra-small-area, low-power analog front-end (AFE) for high-density neural recording is presented in this paper. It features an 11-bit incremental delta-sigma analog-to-digital converter (σ ADC) enhanced with an offset-rejecting event-driven input biasing network. This network avoids saturation of the ADC input caused by leakage of the input-coupling capacitor implemented in an advanced technology node. Combining AC-coupling with direct data conversion, the proposed AFE can tolerate a rail-to-rail electrode offset and achieves a good trade-off between power, noise, bandwidth, input impedance, and area. Fabricated in a 22-nm fully-depleted silicon on insulator (FDSOI) process, the design occupies an active area of

Leakage through a 10 mm diameter circular hole in a geomembrane beneath fine-grained tailings is examined for a range of pore pressures and effective stresses. Leakage was measured in an experiment with coupled physical and hydraulic conditions to simulate the effective stresses and flow conditions near the hole. The leakage rate was as little as 0.16 L/day with 200 kPa pore pressure (10–30 kPa effective stresses) and increased only to 0.46 L/day with 800 kPa pore pressure (200 kPa effective stress). Seepage analysis of the experiment and local measurements of permeability from small samples extracted after the experiment indicate that the tailings hydraulic conductivity controlling flow was 3–6 × 10−9 m/s. Only a subtle decrease in hydraulic conductivity (less than 2 times) near the hole was found. No evidence of seepage-induced migration of fines within the tailings was found. Calculations with the parameters deduced from the experiment show that leakage from a tailings storage facilities containing fine-grained tailings can be limited to 1–2 L/ha/day with a geomembrane liner, even when containing up to five 10 mm diameter holes per hectare, as opposed to an unlined facility with 3 to 4 orders of magnitude more leakage.

Gate valve is mainly used to turn on or turn off the pipeline in pneumatic conveying. When the gate valve is fully open, the particles are easy to collide with the cavity rear wall and enter into the cavity, resulting in particles’ accumulation in the cavity. The particles in cavity will accumulate between the cavity bottom and the flashboard bottom wall and prevent the gate from turning off normally. Meanwhile, the particles’ collision with cavity rear wall will cause serious erosion. Both the particles’ accumulation and erosion will cause the poor sealing of the gate valve, further resulting in the leakage of the pipeline system. To reduce the particles’ accumulation in cavity and erosion on cavity when the gate valve is fully open, we simplify the gate valve into a cavity structure and study it. We find that adding a slope upstream the cavity can effectively reduce the particles’ accumulation in the cavity and the erosion on the cavity rear wall. In this work, Eulerian–Lagrangian method in commercial code (FLUENT) was used to study the gas–solid two-phase flow and erosion characteristics of a cavity with a slope. The particle distribution shows that the particles with Stokes number St = 1.3 and St = 13 cannot enter the cavity due to the slope, but the particles with St = 0.13 enter the cavity following the gas. For St = 13, the particles collide with the wall many times in the ideal cavity. Erosion results show that the slope can transfer the erosion on cavity rear wall to the slope and reduce the maximum erosion rate of the wall near the cavity to some degrees.

A novel methodology to create metallic waveguides with multilayer integrated vertical electromagnetic bandgap (EBG) structure is proposed in this paper, and the structure realizes low-cost millimeter-wave (mmWave) slot array antennas. A multilayer stack of easy-to-process thin metallic etching plates is introduced to design mmWave waveguide using compression-fit instead of diffusion bonding and welding assembly process. The electromagnetic (EM) wave leakage from the gaps between the metallic plates is suppressed using the vertical-EBG structure and anti-phasing feeding. The dispersion diagrams of the vertical-EBG unit cell are investigated to illustrate the suppression of leakage. Another leakage wave intercepting methodology is adopted by anti-phase feeding to prevent leakage wave from adjacent slot sub-arrays. Finally, two examples of 2×8 and 8×8 slot array antennas are presented to verify our design concept. The measured impedance bandwidths of the two antennas are 77.1-84.6 GHz (9.3%) and 78.6-84.9 GHz (7.7%), respectively. In addition, the 3-dB broadside gain bandwidths are 73.1 to 85.3 GHz (15.1%) and 76.8 to 84.4 GHz (9.4%), respectively. The results show aperture efficiencies up to 56.4%.

Dielectric polymer composites with conducting fillers would have great potential for diverse applications if their severe leakage loss could be addressed. In this regard, ternary composites using both ceramic and conducting materials as fillers might be an enabler for high dielectric constant and low dielectric loss. Herein, ternary composites with both Ti3C2Tx MXene conducting nanosheets and CaCu3Ti4O12 (CCTO) dielectric particles embedded in silicone rubber were studied. It was found that a ternary composite with 1.2 wt% (0.40 vol%) Ti3C2Tx MXene and 12 wt% (2.58 vol%) CCTO could provide an overall superior performance that include a high dielectric constant of 8.8, low dielectric loss of less than 0.0015, good thermal stability up to 450 °C, and excellent mechanical properties with tensile strength of 569 kPa, elastic module of 523 kPa and elongation at break of 333%. The outstanding performance is attributed to the improved uniform dispersion and good interfacial compatibility of mixed fillers in the polymer matrix, suggesting ternary composites might be a better option over their binary counterparts in preparing high performance dielectric composites.

Despite of the hazardous risk of Pb2+ leakage, lead dioxide has been attributed as a quasi-ideal anode material with high oxygen evolution potential, excellent conductivity, good stability and low cost in electrochemical oxidation wastewater treatment technique. In this study, a novel Ti/PbO2 anode was fabricated by embedding raw materials that are readily and cheaply available, i.e., hairs. The structure-activity relationship of the new electrode was firstly revealed by material and electrochemical characterizations. Then different levels of pollutants (azo dye, phenol and maleic acid) were used to investigate the electrochemical oxidation performance of the new electrode. Finally, the accelerated electrode lifetime and Pb2+ leakage tests were carried out. Results showed that the embedded hairs changed the preferential crystallographic orientation of PbO2 and decreased the grain size. Hairs introduced additional roughness and active sites, and decreased the electrode impedance, especially under 5 mg/cm2 of embedding amount. The removal efficiencies of different target pollutants were enhanced more or less by embedding appropriate amount of hairs, depending on the current density, but loading excessive hairs had a negative effect. The accumulation of intermediate products during phenol degradation was also changed by the hairs. The new electrode could undergo ∼550 h of harsh electrolysis. It is also relieved that the Pb2+ leakage was found to be suppressed during this long-term electrolysis process.

Background: One of the most important complications of sleeve gastrectomy (SG), a frequently used method in the surgical treatment of obesity, is gastric sleeve leak. The prevention of gastric slee...