scholarly journals A heat-melt adhesive-assisted transferable electrode films

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yuki Maruyama ◽  
Kuniaki Nagamine ◽  
Shigeyuki Iwasa ◽  
Atsushi Miyabo ◽  
Shizuo Tokito

AbstractThis report is the first on heat-assisted transferable battery components, enabling manufacturing batteries on non-planer surfaces such as a curved surface and an edge. The transferrable battery components were composed of two layers: a cathode or an anode and a conductive heal-melt adhesive layer on a silicone-based flexible supporting paper. These mechanically-durable, flexible components enabled conformable adhesion even on curved surfaces and substrate edges. As a model battery, the manganese dioxide-zinc system was constructed on a curved surface using transfer techniques and showed a practical capacity of 1.8 mAh cm−2 per unit electrode area. These transferable electrodes allow arbitrary design of batteries according to the power consumption of IoT devices to be fabricated on unreported geometries where has been considered as a dead space.

Symmetry ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 552 ◽  
Author(s):  
Rocksan Choi ◽  
SeungGwan Lee ◽  
Sungwon Lee

In our modern world, many Internet of Things (IoT) technologies are being researched and developed. IoT devices are currently being used in many fields. IoT devices use Wi-Fi and Bluetooth, however, communication distance is short and battery consumption is high. In areas such as smart cities and smart farms, IoT technology is needed to support a wide coverage with low power consumption. Low Power Wide Area (LPWA), which is a transmission used in IoT supporting a wide area with low power consumption, has evolved. LPWA includes Long Range (LoRa), Narrowband (NB-IoT), and Sigfox. LoRa offers many benefits as it communicates the longest distances, is cheap and consumes less battery. LoRa is used in many countries and covers a range of hundreds of square kilometers (km2) with a single gateway. However, if there are many obstacles to smart cities and smart farms, it causes communication problems. This paper proposes two (2) solutions to this problem: the relay method which is a multi-hop method and the Automatic Repeat Request (ARQ) system that detects packet loss in real-time and requests retransmission for LoRa. In this study, the actual performance of LoRa in the problematic environment was measured and the proposed method was applied. It was confirmed that the transmission rate of LoRa dropped when there were many obstacles such as trees. To use LoRa in a smart farm with a lot of space, multi-hop was observed to be better. An ARQ system is needed to compensate for the unexpected drop in the forward rate due to the increase in IoT devices. This research focused on reliability, however, additional network methods and automatic repeat request (ARQ) systems considering battery time should be researched in symmetry. This study covers the interdisciplinary field of computer science and wireless low power communication engineering. We have analyzed the LoRa/LoRaWAN technology in an experimental approach, which has been somewhat less studied than cellular network or WiFi technology. In addition, we presented and improved the performance evaluation results in consideration of various local and climatic environments.


2008 ◽  
Vol 392-394 ◽  
pp. 151-155
Author(s):  
Tong Wang ◽  
K. Jiang ◽  
Shu Qiang Xie ◽  
Shuang Shuang Hao

In this paper, the characteristics and general laws of cutting complex curved surface by wire electrical discharge machining (WEDM) system are studied. Based on analysis of motion parameters the universal mathematical model of polar coordinates is derived. Moreover, the simulation of WEDM system is introduced, which is carried out by using language Visual C++ and the three dimensional graph software OpenGL.This simulation method is helpful in improving machining quality and productivity of complex curved surfaces, and is fundation for establishing CAD/CAPP/CAM technology in WEDM.


2020 ◽  
pp. 193229682095934
Author(s):  
Piotr Foltynski ◽  
Piotr Ladyzynski

Background: The purpose of this study was to determine the accuracy of wound area measurement at a curved surface using a digital planimetry (DP) with the newly proposed adaptive calibration. Methods: Forty wound shapes were printed and placed at the side surfaces of cylinders with diameters of 9.4 and 6.2 cm. Area measurements were carried out using a commercial device SilhouetteMobile (Aranz, New Zealand) and the planimetric app Planimator. Planimetric area measurements were carried out using 2 one-dimensional calibration markers placed above and below the wound shape. The method of adaptive calibration for DP was described. Reference area values of wound shapes were obtained by pixel counting on digital scans made with an optical scanner. Relative errors (REs) and relative differences (RDs) for area measurements were analyzed. Results: The median of REs for the DP with adaptive calibration (DPwAC) was equal to 0.60% and was significantly smaller than the median for the SilhouetteMobile device (SMD) (2.65%), and significantly smaller than the median for the DP (2.23%). The SD of RDs for the DPwAC of 0.87% was considerably lower than for the SMD (6.45%), and for the DP without adaptive calibration (2.51%). The mean of RDs for the DPwAC (0.082%) was not significantly different from zero, which means that the systematic error was not present for the DPwAC. Conclusions: The use of the adaptive calibration in DP to measure the areas at curved surface resulted in a significant increase of accuracy and precision, and removal of systematic error. The DPwAC revealed 4.4 times lower error and 7.4 times higher precision of area measurement at curved surfaces than the SMD.


2019 ◽  
Vol 20 (05) ◽  
pp. 2050033
Author(s):  
Dong Han ◽  
Min Xia

A generalized dynamically evolving random network and a game model taking place on the evolving network are presented. We show that there exists a high-dimensional critical curved surface of the parameters related the probabilities of adding or removing vertices or edges such that the evolving network may exhibit three kinds of degree distributions as the time goes to infinity when the parameters belong to the super-critical, critical and sub-critical curved surfaces, respectively. Some sufficient conditions are given for the existence of a regular Nash equilibrium which depends on the three kinds of degree distributions in the game model on the limiting random network.


2018 ◽  
Vol 7 (4.6) ◽  
pp. 388
Author(s):  
G. A. Vani ◽  
M. Metilda Florence

The emergence of Internet of things (IoT) is due to its   ability to dutifully transfer the data through a network. Now the concern is that security is not considered as main priority while developing the product. IoT is prone to vulnerabilities where Botnet and DDoS kind of attacks are common and a major issue that has to be considered these days. Since IoT is in no way resistive to attacks, this paper is all about proposing a solution for the Distributed Denial of Services attack that happens on IoT platform. Light weight authentication is necessary for any IoT devices because to reduce the power consumption and increase the processing speed of the device [16]. The experimental setup is built on OS named Contiki with cooja simulator that suits to all the devices that are in the IoT environment.   


2018 ◽  
Vol 7 (2.6) ◽  
pp. 231
Author(s):  
Teyi Yann Cedric Lawson ◽  
Senthilnathan T

Elliptic Curves when compared to other encryptions scheme such as RSA etc., provides an equivalent security, smaller key sizes, less power consumption, faster calculations, less bandwidth used and is more suitable for Internet of Things devices. In addition of encrypting the data, the devices in the network should also be able to authenticate themselves, which can be achieved with the implementation of “Non-Interactive Zero Knowledge protocol” (NIZKP). This protocol involves two parties: The prover and the Verifier. Prover party should prove to the Verifier that they have the knowledge of something, without revealing what is it. In this paper, a study of Schnorr protocol or ∑- protocol over Elliptic Curves is done and the protocol is implemented in Python using the Python Cryptography Toolkit PyCrypto which is a collection of cryptographic modules implementing various algorithms and protocols. Finally, the results were compared with Elliptic Curve Diffie-Hellmann(ECDH) and present a performance evaluation of the protocols on the Raspberry Pi 3B model, a credit-card sized computer used for the development of IoT devices hence the perfect platforms to test the protocol.  


2015 ◽  
Vol 15 (10) ◽  
pp. 5777-5789 ◽  
Author(s):  
Borja Martinez ◽  
Marius Monton ◽  
Ignasi Vilajosana ◽  
Joan Daniel Prades

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Tarek Frikha ◽  
Faten Chaabane ◽  
Nadhir Aouinti ◽  
Omar Cheikhrouhou ◽  
Nader Ben Amor ◽  
...  

The adoption of Internet of Things (IoT) technology across many applications, such as autonomous systems, communication, and healthcare, is driving the market’s growth at a positive rate. The emergence of advanced data analytics techniques such as blockchain for connected IoT devices has the potential to reduce the cost and increase in cloud platform adoption. Blockchain is a key technology for real-time IoT applications providing trust in distributed robotic systems running on embedded hardware without the need for certification authorities. There are many challenges in blockchain IoT applications such as the power consumption and the execution time. These specific constraints have to be carefully considered besides other constraints such as number of nodes and data security. In this paper, a novel approach is discussed based on hybrid HW/SW architecture and designed for Proof of Work (PoW) consensus which is the most used consensus mechanism in blockchain. The proposed architecture is validated using the Ethereum blockchain with the Keccak 256 and the field-programmable gate array (FPGA) ZedBoard development kit. This implementation shows improvement in execution time of 338% and minimizing power consumption of 255% compared to the use of Nvidia Maxwell GPUs.


Author(s):  
Bahador Farshchian ◽  
JaeJong Lee ◽  
Sunggook Park

We report on a simple and effective process that allows direct imprinting of micro- and nanostructures on non-flat surfaces. A thin polydimethylsiloxane (PDMS) stamp having micro/nanogratings was placed between a metallic bar with a trapezoidal cross section or a metallic pellet and a flat polymethyl methacrylate (PMMA) substrate, followed by hot embossing at 200°C. During the hot embossing process, the metallic bar/pellet is pushed into the PMMA sheet forming a millimeter scale channel or a curved surface. Due to the presence of the PDMS stamp between the metallic object and the substrate, micro/nanostructures are produced into the channel or over the curved surface. With this method, we have successfully demonstrated micro- and nanostructures down to 300 nm wide gratings on non-flat substrates, as confirmed by scanning electron microscopy and atomic force microscopy. The process so developed will fill the gap in current micro- and nanofabrication technologies in that most of the technologies allow for patterning only on planar substrates.


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