Characterization of zinc oxide nanoparticles synthesized by polymer assisted deposition method

Zinc oxide nanoparticles (ZNPs) are synthesized onto glass substrates by employing simple and low cost solution based modified polymer assisted deposition (PAD) method. Trionx100 is used as a capping agent and zinc acetate as the zinc source. TritonX100 concentration is varied from 0.02 to 0.45 M for the synthesis of pure ZnO NPs. TG-DTA analysis was employed to determine the decomposition temperature of TritonX100 and zinc acetate, which lead to the formation of ZnO. The films were further characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM) and high-resolution transmission electron microscope (HR-TEM), Fourier transforms infrared spectroscopy (FT-IR) and room temperature photoluminescence (PL). The results indicate that the synthesized nanoparticles (NPs) exhibits the room temperature PL with two emission peaks, one corresponding to ZnO band edge emission and the other one to point defect states created due to oxygen deficiency. The first peak undergoes blue-shift due to change in NPs size while there is no shift in the second peak. Nevertheless, with increase in TritonX100 concentration the peak intensity of defect peak decreases, indicating that the highly pure NPs have been successfully synthesized by PAD method.     

Effect of Nitrogen Content on the Tensile and Stress Corrosion Cracking Behavior of AISI Type 316LN Stainless Steels

This paper deals with the effect of nitrogen on the tensile and stress corrosion cracking (SCC) behavior of type 316LN stainless steel. Yield stress (YS) and ultimate tensile stress (UTS) increased while the ductility [% total elongation (% TE)] decreased with increasing nitrogen content. Evaluation by conventional assessment parameters, such as ratios of UTS, % TE and SCC susceptibility index, derived by SCC testing using the slow strain rate testing (SSRT) technique indicated an improvement in SCC resistance on increasing the nitrogen content. However, crack growth rates, calculated from ratios of fracture stress from the SSRT tests in liquid paraffin and boiling 45 % magnesium chloride in SSRT tests, and the constant load tests at loads corresponding to 20 % YS in boiling 45 % magnesium chloride conclusively established that the SCC resistance of type 316LN stainless steel decreased with increasing nitrogen content.     

A DCT-Based Local Dominant Feature Extraction Algorithm for Palm-Print Recognition

In this paper, a frequency domain feature extraction algorithm for palm-print recognition is proposed, which efficiently exploits the local spatial variations in a palm-print image. The entire image is segmented into several small spatial modules and the effect of modularization in terms of the entropy content of the palm-print images has been investigated. A palm-print recognition scheme is developed based on extracting dominant spectral features from each of these local modules using a two-dimensional discrete cosine transform (2D-DCT). The proposed dominant spectral feature selection algorithm offers the advantage of having very low feature dimension, and it is capable of capturing precisely the variations in detail within the palm-print image. It is shown that because of modularization of the palm-print image, the discriminating capabilities of the proposed features are enhanced, which results in a very high within-class compactness and between-class separability of the extracted features. A principal component analysis is performed to further reduce the feature dimension. From our extensive experimentations on different palm-print databases, it is found that the performance of the proposed method in terms of recognition accuracy and computational complexity is superior to that of some of the recent methods.     

Progress in Carbon Fiber and Its Polypropylene- and Polyethylene-Based Composites

Due to their lightweight and excellent toughness, carbon fiber (CF) and its reinforced thermoplastic composites are suitable for high-performance applications such as aerospace, aviation, automotive and sport equipments. In this study, comprehensive detail is provided on the production of carbon fiber, its various forms and geometry and their corresponding effects on the mechanical properties of CF and its reinforced polypropylene (PP) and polyethylene (PE) composites. Here we discuss extensively various methods reported in literature on improving the interfacial fiber-matrix adhesion and dispersion in order to achieve better mechanical properties for such composites.     

Tele-COVID: A Telemedicine SOA-Based Architectural Design for COVID-19 Patients

In Wuhan, China, a novel Corona Virus (COVID-19) was detected in December 2019; it has changed the entire world and to date, the number of diagnosed cases is 38,756,289¹ and 1,095,216¹ people have died. This happened because a large number of people got affected and there is a lack of hospitals for COVID-19 patients. One of the precautionary measures for COVID-19 patients is isolation. To support this, there is an urgent need for a platform that makes treatment possible from a distance. Telemedicine systems have been drastically increasing in number and size over recent years. This increasing number intensifies the extensive need for telemedicine for the national healthcare system. In this paper, we present Tele-COVID which is a telemedicine application to treat COVID-19 patients from a distance. Tele-COVID is uniquely designed and implemented in Service-Oriented Architecture (SOA) to avoid the problem of interoperability, vendor lock-in, and data interchange. With the help of Tele-COVID, the treatment of patients at a distance is possible without the need for them to visit hospitals; in case of emergency, necessary services can also be provided.     

Techno‐Economic Analysis of a Coal Staged Conversion Polygeneration System for Power and Chemicals Production

Steady‐state process simulation and techno‐economic analysis of a pyrolysis‐based coal staged conversion polygeneration (CSCP) plant, integrated with wastewater biochemical treatment after phenol‐ammonia recovery, are studied using Aspen Plus software. Appropriate models for the proposed system are set up in detail. Furthermore, by optimization of a methanation unit, a conventional supercritical circulating fluidized bed (SCCFB) power plant with the same capacity is chosen for comparison. Simulation results reveal that system energy and exergy efficiency of the CSCP system can reach much higher values than those of a conventional SCCFB power plant. In conclusion, a CSCP plant will have practical and economic advantages in the near future.     

Book Review

Arsenic in the Environment Part I: Cycling and Characterization. 430 pages, hard cover. Part 11: Human Health and Ecosystem Effects. 292 pages, hard cover Volume 26 in the Wiley Series in Advancements in Environmental Science and Technology Published by: John Wiley and Sons, Inc., New York, 1994 Editor: Jerome O. Nriagu     

Synthesis and characterization of nanosized polylactic acid/TiO<Subscript>2</Subscript> particle brushes by azeotropic dehydration polycondensation of lactic acid

A method for the synthesis of particle brushes by grafting polylactic acid onto TiO₂ nanoparticle is reported. The efficiency of grafting was enhanced by combining azeotropic separation of water with polycondensation in a single pot. PLA/TiO₂ brushes synthesized with different ratio of lactic acid and TiO₂ were characterized by various techniques such as FT-IR, XRD, TEM, XPS, ¹H and ¹³C NMR. TEM analysis indicates that the sizes of TiO₂ nanoparticles are between 2 and 8 nm. DLS was used to determine overall size of particle brush and average size varied between 59.68–65.83 nm. Zeta potential measurement indicated high stability of water dispersed particles brushes with measured values of ?30.1 to ?37.1 mV for brushes prepared with PLA/TiO₂ ratio of 50:1 and 20:1 respectively. The DSC and TGA analysis showed that PLA/TiO₂ nanocomposites have good thermal stability.

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Fine-Grained Video Traffic Classification Based on QoE Values

The paper proposes a set of features suitable for fine-grained traffic classification of network video, with data collected from real network. These features are parameters related to quality of experience (QoE), which reflects the user’s perception. The QoE value is calculated based on the ITU-T P.1201/Amd2 standard. Under this standard, each video flow can calculate corresponding QoE value and its probability of distribution. One innovative aspect of the paper is that the characteristics of QoE value and its probability distribution are extracted as the discriminating features which are suitable for video traffic classification. The extracted features of QoE distribution are typically mean, variance, maximum and minimum statistical characteristics, and the probability distribution of features can be obtained. Different from previous work, in our method, we obtain for the first time the discrete distribution of probability with five values, and use them directly as independent features to participate in feature selection and classification. The experimental results demonstrate that the proposed new features can significantly improve classification accuracy compared with an existing method.

     

A comprehensive survey of human action recognition with spatio-temporal interest point (STIP) detector

Over the past two decades, human action recognition from video has been an important area of research in computer vision. Its applications include surveillance systems, human–computer interactions and various real-world applications where one of the actor is a human being. A number of review works have been done by several researchers in the context of human action recognition. However, it is found that there is a gap in literature when it comes to methodologies of STIP-based detector for human action recognition. This paper presents a comprehensive review on STIP-based methods for human action recognition. STIP-based detectors are robust in detecting interest points from video in spatio-temporal domain. This paper also summarizes related public datasets useful for comparing performances of various techniques.