Study of mechanical and dynamic mechanical behavior of halloysite nanotube-reinforced multiscale syntactic foam

The present study deals with the development of novel cenosphere-epoxy multiscale syntactic foam (MSF) reinforced with halloysite nanotubes (HNTs). Cenospheres with different volume fractions (0, 20, 30, 40, 50 vol%) and HNTs (1 vol%) used in the fabrication of syntactic foams. The addition of HNTs increases the tensile modulus (42%) and flexural modulus (66%) compared with plain syntactic foam (PSF). Furthermore, FTIR studies reveal the strong hydrogen bonding interaction between HNTs and epoxy. Field emission scanning electron microscopy (FESEM) confirms the unique crack deflection phenomenon by HNT, which indicates the structure–property correlation. In addition, the storage and loss modulus of MSFs is 36 and 113%, respectively (at 30°C) higher than the neat epoxy. Improvement in the tensile and flexural properties along with excellent thermal stability at elevated temperature makes MSF a promising material for structural, weight-sensitive, and high-temperature applications.     

Improving Public Urban Services through Increased Accountability

This paper is concerned with the potential of accountability to improve the performance of public urban services. A number of assumptions are made in the literature relating to accountability; these concern the necessity of multiple strategies of accountability, information symmetries, sanctions, trust, homogeneous service users, community-level answerability, incentives, self-regarding behavior, and for users’ voice to be heard in service delivery. It is the purpose of this paper to reconsider these theoretical propositions for the functioning of accountability in light of practical experience from the United Kingdom, South Africa, Bangladesh, and South Korea. Each of these case studies was selected to illustrate a different form of accountability. The forms of accountability investigated in this research are professional, political, user, and managerial accountabilities. An assessment is made of whether accountability is demonstrated in these case studies in the way predicted by the literature. The empirical data demonstrate that factors like multiple strategies and information/resource symmetries are critical to accountability but that there is only partial evidence to support the need for sanctions, trust, incentives, self-interest, and user voice for effective service delivery. The research indicates the need for greater emphasis on the operation and maintenance of urban services and direct accountability to service users. However the assumption that service users are homogeneous is disputed. This paper concludes with a review of the practical implications of strengthening accountability as a means to improve the performance of urban services.     

A hybrid intelligent system to improve predictive accuracy for cache prefetching

Cache being the fastest medium in memory hierarchy has a vital role to play for fully exploiting available resources, concealing latencies in IO operations, languishing the impact of these latencies and hence in improving system response time. Despite plenty of efforts made, caches alone cannot comprehend larger storage requirements without prefetching. Cache prefetching is speculatively fetching data to restrain all delays. However, effective prefetching requires a strong prediction mechanism to load relevant data with higher degree of accuracy. In order to ameliorate the predictive performance of cache prefetching, we applied the hybrid of two AI approaches named case based reasoning (CBR) and artificial neural networks (ANN). CBR maintains the past experience and ANN are used in adaptation phase of CBR instead of employing static rule base. The novelty of technique in this domain is valued due to hybrid of two approaches as well as usage of suffix tree in populating the CBR’s case base. Suffix trees provide rich data patterns for populating case base and greatly enhanced the overall performance. A number of evaluations from different aspects with varying parameters are presented (along with some findings) where the efficacy of our technique is affirmed with improved predictive accuracy and reduced level of associated costs.     

Lactobacillus acidophilus: Characterization of the Species and Application in Food Production

L. acidophilus is a homofermentative, microaerophilic, short chain gram positive microorganism with rod morphology having its bacteriocins belonging to class II a. Several bacteriocins of L. acidophilus have been isolated and characterized. These are structurally similar, but their molecular weight varies as well as their spectrum of antimicrobial activity. They exhibit important technical properties, i.e., thermostability and retaining of activity at a wide pH range along with strong inhibitory actions against food spoilage and pathogenic bacteria make them an important class of biopreservatives. L. acidophilus can be added as an adjunct in many food fermentation processes contributing to unique taste, flavor, and texture. It also preserves the products by producing lactic acid and bacteriocins. A lot of new information regarding the bacteriocins of L. acidophilus has emerged during the last few years. In this review, an attempt has been made to summarize and discuss all the available information regarding the sources of bacteriocins production, their characteristics, and their antimicrobial action along with their application.     

Laser welding of Haynes 188 alloy sheet: thermal stress analysis

Laser welding of Haynes 188 alloy sheets is carried out. Temperature and stress fields developed in the welding section are predicted numerically incorporating the finite element algorithm. The microstructural changes in the welding region are examined using the optical and electron scanning microscopes. The microhardness variation across the weld zone is measured and associated with the residual stress formed in this region. It is found that the microhardness follows the residual stress distribution in the weld core. The maximum residual stress is less than the elastic limit of the substrate material.     

High Coercivity and Magnetization in WSe2 by Codoping Co and Nb

Introducing ferromagnetism in transition metal dichalcogenides has attracted lots of attention due to the possible applications in spintronics devices. Generally, single magnetic element doping is used to introduce magnetism. However, mostly, weak ferromagnetism is observed. In this work, codoping of two kinds of transition metals (Nb and Co) into WSe₂ is used to study its magnetic properties. In detail, single crystal WSe₂ is codoped with 4 at% Co and various concentrations of Nb by employing the physical ion implantation method. Raman, X‐ray diffraction and X‐ray photoelectron spectroscopy results reveal the effective substitutional doping of implanted elements (Co and Nb). Magnetic measurements illustrate that both un‐doped and 4 at% Co doped WSe₂ show weak ferromagnetism whereas magnetization is strongly enhanced when Co and Nb are codoped into WSe₂. The magnetization is comparable with a ferromagnet, which may be attributed to Co, Nb doping and defects. In addition, a large coercivity of ≈1.2 kOe is observed in the 1 at% Nb–4 at% Co codoped WSe₂ sample, which may be ascribed to the combined effect of doping‐induced stress, defect‐dictated pinning and anisotropy of Nb? Se bond owing to the charge transfer between Nb and Se ions.     

Fuzzy based Impulse Noise Reduction Method

In this paper, we propose an image filtering technique based on fuzzy logic control to remove impulse noise for low as well as highly corrupted images. The proposed method is based on noise detection, noise removal and edge preservation modules. The main advantage of the proposed technique over the other filtering techniques is its superior noise removal as well as detail preserving capability. Based on the criteria of peak-signal-to-noise-ratio (PSNR), mean square error (MSE), structural similarity index measure (SSIM) and subjective evaluation measure we have found experimentally that the proposed method provides much better performance than the state-of-the-art filters. To analyze the detail preservation capability of the proposed filter sensitivity analysis is performed by changing the detail preservation module to see its effects on the details (texture and edge information) of resultant image. This sensitivity analysis proves experimentally that significant image details have been preserved by the proposed method.     

Intelligent noise detection and filtering using neuro-fuzzy system

In this paper, we propose a neuro-fuzzy based blind image restoration to remove impulse noise from low as well as highly corrupted images. Main components of the proposed technique include noise detection, histogram estimation and noise filtering process. Proposed technique constructs the fuzzy sets using fuzzy number construction algorithm. These fuzzy sets are used in noise filtering process to remove impulse noise from the noisy pixels using neuro-fuzzy inference system and fuzzy decider. Experimental results are based on global and local error measures, which prove that the proposed technique gives superior results than the present well known impulse noise filtering methods.     

Complex service design: A virtual enterprise architecture for logistics service

This paper presents an interdisciplinary systems approach to service modeling, design and deployment. The study is based on a longitudinal case study of the development process of a complex logistic service system based on an advanced logistics model. The case examines the development of a Virtual Enterprise Architecture (VEA) for an automatic high-speed transport and sorting system applied in airports for baggage handling. The study traces the evolution of the system from the early conceptual phases to a successful commercial service deployed at Changi, Singapore Airport. The study is conducted using a retrospective analysis of the case using a design science research approach. The paper evaluates and discusses the issues of creating and designing a new complex logistics service, distinct from the physical product, based on an advanced discrete event-based simulation model. The paper concludes by presenting a generalized and validated conceptual framework for a VEA based on an advanced simulation model. The paper thus contributes to the field of service systems and service management by identifying a novel approach to effective design of a new service.