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Article
Publication date: 27 September 2011

Robert Bogue

This paper aims to provide an overview of the strategies and techniques being used and developed for the fabrication of nanoscale devices.

Abstract

Purpose

This paper aims to provide an overview of the strategies and techniques being used and developed for the fabrication of nanoscale devices.

Design/methodology/approach

This paper discusses various nanofabrication technologies and strategies and highlights their merits and limitations. It concludes with a consideration of longer‐term possibilities.

Findings

It is shown that top‐down nanofabrication frequently uses lithographic and other techniques derived from the microtechnology industry but recent research appears to have identified a limit to its capabilities. Bottom‐up nanofabrication is less well‐developed but techniques such as molecular mechanosynthesis may offer unique capabilities in the longer‐term.

Originality/value

The paper provides a timely review of the rapidly developing field of nanofabrication technology.

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Abstract

Details

Foresight, vol. 5 no. 3
Type: Research Article
ISSN: 1463-6689

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Article
Publication date: 10 August 2018

Maogen Ge, Jing Hu, Mingzhou Liu and Yuan Zhang

As the last link of product remanufacturing, reassembly process is of great importance in increasing the utilization of remanufactured parts as well as decreasing the…

Abstract

Purpose

As the last link of product remanufacturing, reassembly process is of great importance in increasing the utilization of remanufactured parts as well as decreasing the production cost for remanufacturing enterprises. It is a common problem that a large amount of remanufactured part/reused part which past the dimension standard have been scrapped, which have increased the production cost of remanufacturing enterprises to a large extent. With the aim to improve the utilization of remanufacturing parts with qualified quality attributes but exceed dimension, the purpose of this paper is to put forward a reassembly classification selection method based on the Markov Chain.

Design/methodology/approach

To begin with, a classification standard of reassembly parts is proposed. With the thinking of traditional ABC analysis, a classification management method of reassembly parts for remanufactured engine is proposed. Then, a homogeneous Markov Chain of reassembly process is built after grading the matching dimension of reassembly parts with different variety. And the reassembly parts selection model is constructed based on the Markov Chain. Besides, the reassembly classification selection model and its flow chart are proposed by combining the researches above. Finally, the assembly process of remanufactured crankshaft is adopted as a representative example for illustrating the feasibility and the effectiveness of the method proposed.

Findings

The reassembly classification selection method based on the Markov Chain is an effective method in improving the utilization of remanufacturing parts/reused parts. The average utilization of remanufactured crankcase has increased from 35.7 to 80.1 per cent and the average utilization of reused crankcase has increased from 4.2 to 14 per cent as shown in the representative example.

Originality/value

The reassembly classification selection method based on the Markov Chain is of great importance in enhancing the economic benefit for remanufacturing enterprises by improving the utilization of remanufactured parts/reused parts.

Details

Assembly Automation, vol. 38 no. 4
Type: Research Article
ISSN: 0144-5154

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Article
Publication date: 1 March 1987

J.R. Barker

The stimulus of the successful semiconductor device miniaturisation programmes coupled to recent progress in synthetic chemistry and molecular engineering has led to the…

Abstract

The stimulus of the successful semiconductor device miniaturisation programmes coupled to recent progress in synthetic chemistry and molecular engineering has led to the emergence of a new inter‐disciplinary activity—molecular electronics—which holds long‐term promise for a new range of electronic materials and devices. From very speculative origins the field has begun to generate important applications based on photoresists, Langmuir‐Blodgett films, electroactive polymers and photochromic materials. A selection of topics ranging from molecular switches, memories, sensors, and the biological interface to prospects for a molecular computer are discussed with special emphasis on features such as stability, self‐organisation and self‐assembly which are unique to molecular systems.

Details

Microelectronics International, vol. 4 no. 3
Type: Research Article
ISSN: 1356-5362

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Article
Publication date: 5 December 2018

Lin Liu, Hongyu Su, Xue Li, Yanan Wang, Qiang Zhang and Jianhua Qian

This paper aims to evaluate the inhibitive effect and adsorption behavior of the 2-amino-5-thiol-1,3,4-thiadiazole vanillin (A) on copper in 3 per cent NaCl solution.

Abstract

Purpose

This paper aims to evaluate the inhibitive effect and adsorption behavior of the 2-amino-5-thiol-1,3,4-thiadiazole vanillin (A) on copper in 3 per cent NaCl solution.

Design/methodology/approach

A thiazole Schiff bases were synthesized, named, 2-amino-5-thiol-1,3,4-thiadiazole vanillin (A), which was fabricated respectively on copper surface by the molecular self-assembled. Evaluation was carried out by electrochemical measurement and surface analysis techniques. Measurement of static friction coefficient scanning electron microscopy and Contact angle analysis were applied, and it is finally confirmed the existence of the adsorbed film. The inhibitive mechanism of A was evaluated by means of quantitative calculation and molecular dynamics simulation.

Findings

The electrochemical measurement indicated that the self-assembled molecular film can effectively inhibit the corrosion of copper sheet, when the concentration was 15 mmol⋅L−1 and the assembly time was 6 h, the corrosion inhibition effect was the best, reaching as high as 97.5 per cent. Scanning electron microscopy results showed that the Schiff base compound forms a protective film on the surface of the copper, which effectively blocks the transfer of corrosion particles to the metal substrate, thereby inhibiting the occurrence of corrosion. Adsorption behavior of A followed the Langmuir’s adsorption isotherm and attributed to mixed-type adsorption. The results of Quantitative calculation and molecular dynamics simulation showed that A was adsorbed on Cu (111) surface in parallel.

Research limitations/implications

In this study, the corrosion inhibition properties of Schiff base film were investigated by combining theory with experiment. Theoretical calculation is helpful to guide the synthesis of efficient and environmentally friendly corrosion inhibitors.

Practical implications

The damage caused by metal corrosion is great. The self-assembled Schiff base membrane synthesized in this paper is simple and compact, and the corrosion inhibition efficiency of copper in 3 per cent NaCl solution is 97.5 per cent.

Social implications

Inhibition of metal corrosion can better save energy and reduce economic losses.

Originality/value

The synthesized Schiff base was prepared on the copper surface by the molecular self-assembled. The Schiff base membrane has a good corrosion inhibition effect on copper in 3 per cent NaCl solution, and the corrosion inhibition efficiency is up to 97.5 per cent.

Details

Anti-Corrosion Methods and Materials, vol. 66 no. 2
Type: Research Article
ISSN: 0003-5599

Keywords

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Article
Publication date: 1 May 2019

Wenjing Li, Qi Wang, Yongshan Ma, Tianyi Jiang, Yanyan Zhu, Yuanyuan Shao, Cuizhen Sun and Junsen Wu

Self-organization has been regarded as a tool for the synthesis of well-defined organic nanostructures. Heterocyclic annulated perylene diimides are the subjects of…

Abstract

Purpose

Self-organization has been regarded as a tool for the synthesis of well-defined organic nanostructures. Heterocyclic annulated perylene diimides are the subjects of considerable current research studies. The purpose of this study is to reveal the photophysical property, electronic structure and solid-state packing of O-heterocyclic annulated perylene diimide.

Design/methodology/approach

Asymmetrically five-membered O-heterocyclic annulated perylene diimide (OAPDI) was synthesized. Structure and purity of OAPDI were confirmed by 1H NMR, 13C NMR, IR and mass spectral techniques. Photophysical properties of OAPDI were studied using UV–vis absorption and fluorescence in both solution (CHCl3) and solid state. Scanning electron microscopic and atomic force microscopy were used to characterize the surface morphology of OAPDI. Conducting properties of the OAPDI were evaluated by current–voltage measurements. The compounds geometries were also optimized at 6-31G* using density functional theory.

Findings

The UV–vis absorption and fluorescence spectra of OAPDI in solution are blue-shifted in comparison with that of unsubstituted perylene bisimide. Solid-state UV–vis measurements of OAPDI indicate that it is capable of forming highly ordered structure. The non-covalent interactions, electrostatic attraction and p-p stacking moieties of OAPDI synergistically guide assembly and domain growth while maintaining the interpenetrating network of nanofibers in the solid film. The OAPDI gave higher current at −2.0 V (0.68 µA) and 4.0 V (1.0 µA).

Originality/value

This study will be helpful for exploring feasible routes to acquire soluble perylene diimides and well-defined organic nanostructures. Furthermore, such molecular tailoring approach would be helpful for designing and synthesizing novel organic semiconductive materials with excellent charge-transporting and light-emitting capabilities.

Details

Pigment & Resin Technology, vol. 48 no. 3
Type: Research Article
ISSN: 0369-9420

Keywords

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Article
Publication date: 10 May 2021

María V. Puc-Oxté and Máximo A. Pech-Canul

This paper aims to prepare highly hydrophobic films on aluminum AA3003 using myristic acid (MA) and evaluate its corrosion protection efficiency in a low-chloride solution.

Abstract

Purpose

This paper aims to prepare highly hydrophobic films on aluminum AA3003 using myristic acid (MA) and evaluate its corrosion protection efficiency in a low-chloride solution.

Design/methodology/approach

The aluminum surface was initially treated with boiling water to develop a porous nanostructure, and then surface modification was carried out in ethanolic solutions with different concentrations of MA. The surface morphology, wetting behavior and film composition were first characterized, and then, the corrosion behavior was evaluated with electrochemical techniques.

Findings

The best hydrophobicity and corrosion resistance were obtained with 50 mM of MA. For such concentration, a water contact angle of 140° and protective efficiency of 96% were achieved. A multilayer structure was revealed by scanning electron microscope and X-ray photoelectron spectroscopy.

Originality/value

The results of this work shed light on the anticorrosion performance of fatty acid self-assembled multilayers on the surface of Al–Mn alloys.

Details

Anti-Corrosion Methods and Materials, vol. 68 no. 3
Type: Research Article
ISSN: 0003-5599

Keywords

Content available
Article
Publication date: 27 September 2011

Abstract

Details

Assembly Automation, vol. 31 no. 4
Type: Research Article
ISSN: 0144-5154

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Article
Publication date: 4 January 2019

Wenhao Wang, Rujing Shi, Wei Zhang, Haibin Sun, Xiaolu Ge and Chengfeng Li

The purpose of this paper is to improve the generation efficiency of singlet oxygen of methylene blue molecules through finely controlling their aggregation states in drug…

Abstract

Purpose

The purpose of this paper is to improve the generation efficiency of singlet oxygen of methylene blue molecules through finely controlling their aggregation states in drug carriers.

Design/methodology/approach

As a photosensitiser in photodynamic therapy, methylene blue (MB) was loaded on citrate-modified hydroxyapatite (HAp) through an electrostatic interaction and followed by encapsulation of coordination complexes of tannic acid (TA) and Fe(III) ions. Ultraviolet-visible absorption spectrum of the supernatant after incubation of samples was recorded at certain time interval to investigate the release behaviour of MB. Photodynamic activity of MB was determined by the oxidation reaction of uric acid by singlet oxygen generated by MB under illumination.

Findings

Almost all MB molecules were immediately released from HAp-MB, whilst an initial burst release of MB from HAp-MB@TA was followed by a sustainable and pH-sensitised release. In comparison with HAp-MB, photocatalystic reduction of HAp-MB@TA by titanium dioxide hardly occurred under illumination, indicating the stability against reduction to leukomethylene blue in vitro. Generation efficiency of singlet oxygen by MB released from HAp-MB@TA was significantly higher than that from HAp-MB because of the control of TA and Fe(III) ions complexes on molecular structures of released MB.

Originality/value

A facile method was herein demonstrated to optimise the generation efficiency of singlet oxygen by controlling aggregation states of PS molecules and improve PDT efficiency to damage tumour tissues.

Details

Pigment & Resin Technology, vol. 48 no. 2
Type: Research Article
ISSN: 0369-9420

Keywords

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Article
Publication date: 14 June 2011

Andrew Adamatzky

Delaunay triangulations provide a good alternative to existing approaches of modelling unstructured unconventional computers. Experimental research in novel and emerging…

Abstract

Purpose

Delaunay triangulations provide a good alternative to existing approaches of modelling unstructured unconventional computers. Experimental research in novel and emerging computing paradigms and materials shows a great progress in designing laboratory prototypes of spatially extended computing devices. In these devices, computation is implemented by excitation waves and localisations in reaction‐diffusion chemical media, geometrically constrained and compartmentalized excitable substrates, organic molecular assemblies, and gas‐discharge systems. These unconventional computing substrates can be formally represented by Delaunay triangulations with excitable nodes. Thus, it is important to uncover most common types of excitation dynamics on the Delaunay diagrams. The purpose of this paper is to define excitable automata on Delaunay triangulation and demonstrate how to control a space‐time dynamics of excitation on the triangulation using absolute and relative excitability thresholds.

Design/methodology/approach

The paper modifies classical Greenberg‐Hasting model to topology of Delaunay triangulations and considers not only a threshold of excitation but also a ratio of excited neighbours as an essential factor of nodes' activation. Delaunay triangulations for various densities of nodes packaging are considered.

Findings

The paper defines excitable automata on Delaunay triangulation and demonstrates how to control a space‐time dynamics of excitation on the triangulation using absolute and relative excitability thresholds. The paper uncovers several interesting phenomena ranging from reaction of excitation waves by edge of triangulation to branching domains of activity guided by travelling localized excitations.

Originality/value

The findings reported in the paper will contribute towards designs of novel computing substrates in non‐crystalline structure. Also, automaton interpretation of activity dynamics on Delaunay triangulation can make a viable model of automaton‐network approaches to design of nano‐computing devices.

Details

Kybernetes, vol. 40 no. 5/6
Type: Research Article
ISSN: 0368-492X

Keywords

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