Chemically and mechanically exfoliated MoS2 for electronic & opto-electronic devices

Author(s):  
Anupama B. Kaul
Keyword(s):  
Author(s):  
J.A. Panitz

The first few atomic layers of a solid can form a barrier between its interior and an often hostile environment. Although adsorption at the vacuum-solid interface has been studied in great detail, little is known about adsorption at the liquid-solid interface. Adsorption at a liquid-solid interface is of intrinsic interest, and is of technological importance because it provides a way to coat a surface with monolayer or multilayer structures. A pinhole free monolayer (with a reasonable dielectric constant) could lead to the development of nanoscale capacitors with unique characteristics and lithographic resists that surpass the resolution of their conventional counterparts. Chemically selective adsorption is of particular interest because it can be used to passivate a surface from external modification or change the wear and the lubrication properties of a surface to reflect new and useful properties. Immunochemical adsorption could be used to fabricate novel molecular electronic devices or to construct small, “smart”, unobtrusive sensors with the potential to detect a wide variety of preselected species at the molecular level. These might include a particular carcinogen in the environment, a specific type of explosive, a chemical agent, a virus, or even a tumor in the human body.


Author(s):  
Byung-Teak Lee

Grown-in dislocations in GaAs have been a major obstacle in utilizing this material for the potential electronic devices. Although it has been proposed in many reports that supersaturation of point defects can generate dislocation loops in growing crystals and can be a main formation mechanism of grown-in dislocations, there are very few reports on either the observation or the structural analysis of the stoichiometry-generated loops. In this work, dislocation loops in an arsenic-rich GaAs crystal have been studied by transmission electron microscopy.The single crystal with high arsenic concentration was grown using the Horizontal Bridgman method. The arsenic source temperature during the crystal growth was about 630°C whereas 617±1°C is normally believed to be optimum one to grow a stoichiometric compound. Samples with various orientations were prepared either by chemical thinning or ion milling and examined in both a JEOL JEM 200CX and a Siemens Elmiskop 102.


Author(s):  
S. G. Grigoriev ◽  
M. V. Kurnosenko ◽  
A. M. Kostyuk

The article discusses possible forms of educational STEM projects in the field of electronics and device control using Arduino controllers. As you know, the implementation of such STEM projects can be carried out not only using various electronic constructors, but also using virtual modeling environments. The knowledge obtained during modeling in virtual environments makes it possible to increase the efficiency of face-to-face practical training with a real constructor, and to improve the quality of students’ knowledge. The use of virtual modeling environments in combination with the use of real constructors provides links between distance and full-time learning. A real constructors can be used simultaneously by both the teacher and the student, jointly practicing the features of solving practical problems. The article provides examples of using a virtual environment for preliminary prototyping of circuits available in the documentation for electronic constructors, to familiarize students with the basics of designing and assembling electronic circuits using the surface mounting method and on a breadboard, as well as programming controllers on the Arduino platform that control electronic devices. This approach allows students to accelerate the assimilation of various interdisciplinary knowledge in the field of natural sciences using STEM design.


2018 ◽  
Vol 3 (2) ◽  
pp. 74
Author(s):  
Helina Apriyani ◽  
Sismadi Sismadi ◽  
Sefrika Sefrika

AbstrakInternet of things (IoT) adalah sebuah konsep yang menghubungkan komputer dan perangkat elektronik melalui internet dan dapat dikendalikan dari jarak jauh. Konsep terpenting dalam Internet of things (Iot) adalah modul sistem informasi, koneksi internet dan penyimpanan datanya dalam cloud computing. Konsep ini memiliki manfaat besar dalam perkembangan usaha dan kelangsungan bisnis perusahaan dimana hampir semua bidang menggunakan IoT untuk dapat bersaing di pasaran. Indonesia merupakan sebuah negara yang dianugerahi kekayaan alam yang melimpah ruah. Salah satu komoditi unggulan adalah produk pertanian. Penelitian ini bertujuan untuk membantu para petani dalam memasarkan produknya melalui e-commerce dengan menggunakan konsep Internet of things IoT. Metode penelitian dengan menggunakan metode incremental.  Incremental digunakan untuk mendesai produk, kemudian  diimplementasikan, dan diuji secara bertahap (setiap modul akan ditambahkan bertahap) hingga produk selesai. Hasil penelitian ini digunakan untuk membantu petani di Kabupaten Bogor untuk mendistribusikan penjualannya secara luas, meningkatkan revenue dan memutus rantai panjang proses penjualan. Kata kunci— sistem penjualan, incremental, Internet of Things (IoT), produk pertanian, Kabupaten Bogor Abstract Internet of things (IoT) is a concept that connects computers and electronic devices via the internet and can be controlled remotely. The main concept in Internet of things (IoT) is information systems, internet connections and data storage in cloud computing. This concept has great benefits in the efforts and efforts used to use IoT to be able to compete in the market. Indonesia is a country that is blessed with abundant natural resources. One of the leading commodities is agricultural products. This study aims to help farmers market their products through e-commerce using the IoT Internet of things concept. Research method using incremental method. Incremental to design the product, then implemented, and gradually delay (each module will be added gradually) until the product is finished. The results of this study are to help farmers in Bogor Regency to distribute sales widely, increase revenue and break the sales process. Keywords—sales system, incremental, Internet of Things (IoT), agricultural products, Kabupaten Bogor


2019 ◽  
Vol 1 (2) ◽  
pp. 25-33
Author(s):  
Mei Ling Phang ◽  
Swee Huay Heng

Information sharing has become prevalent due to the expansion of social networking in this 21st century. However, electronic devices are vulnerable to various kinds of attacks. Information might be disclosed, modified and accessed by an unauthorised third party which consequently leads to the breach of confidentiality, integrity and availability of the information. Therefore, it is of utmost importance to employ the technology of cryptography and steganography to protect information assets. Cryptography and steganography have weaknesses when they are working alone. Therefore, crypto-steganography, the combination of cryptography and steganography are introduced to overcome the weaknesses in order to provide a double layer of security and protection. This paper provides a general overview of steganography and cryptography as well as a comparison analysis of different crypto-steganographic schemes. A secure crypto-steganographic system for healthcare is then developed with the implementation and integration of the secure crypto-steganographic scheme proposed by Juneja and Sandhu. This healthcare system enables users to store and deliver message in a more secure way while achieving the main goals of both cryptography and steganography.


2008 ◽  
Vol 128 (12) ◽  
pp. 1373-1380
Author(s):  
Satoshi Sugahara ◽  
Kouhei Yamada ◽  
Haruhiko Nishio ◽  
Masaharu Edo ◽  
Toshiro Sato ◽  
...  

2011 ◽  
Vol 3 (1) ◽  
pp. 74
Author(s):  
Kathy L Lee ◽  

Cardiac pacemakers have been the standard therapy for patients with bradyarrhythmias for several decades. The pacing lead is an integral part of the system, serving as a conduit for the delivery of energy pulses to stimulate the myocardium. However, it is also the Achilles’ heel of pacemakers, being the direct cause of most device complications both acutely during implant and chronically years afterwards. Leadless pacing with ultrasound-mediated energy has been demonstrated in animals and humans to be safe and feasible in acute studies. Implantable defibrillators revolutionised the treatment and prevention of sudden cardiac death. Subcutaneous implantable defibrillators have been under development for more than 10 years. A permanent implantable system has been shown to be feasible in treating induced and spontaneous ventricular tachyarrhythmias. These developments and recent advances in pacing and defibrillation will arouse further interest in the research and development of leadless cardiac implantable electronic devices.


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