Orientation studies of poly(ethylene terephthalate)

This paper discusses the results of a detailed study of the relationships between molecular orientation, physical properties, and molecular weight of polyethylene terephthalate (PET), and their dependence on orientation variables. The molecular weight range of the samples used in this study included weight average molecular weights, M_w, between 29,000 and 65,000 which correspond to inherent viscosities, I.V., from 0.5 to 0.9. The orientation temperatures investigated were between 80 and 120°C. The extent of molecular ordering imparted by the orientation process was studied by birefringence, density, light scattering, and depolarized light intensity techniques. The results show that the degree of molecular orientation and the physical properties are strongly dependent on strain rate, extension ratio, molecular weight, and orientation temperature. The mechanical and transport properties, of PET are directly related to the degree of orientation as measured by birefringence. It is found that at a comparable level of orientation, the mechanical properties are also dependent on molecular weight, whereas the transport properties are independent of molecular weight. The degree of orientation varies according to the molecular weight of PET and stretch temperature. It is shown that for the same stretch ratio and stretch speed, the birefringence decreases with increasing stretch temperature. The light scattering results indicate that biaxial orientation of PET can lead to strain-induced crystallization. The amount and form of the crystalline structures are dependent on strain rate and orientation temperature.     

Electrochemical hydrogen evolution on polypyrrole from alkaline solutions

Thin films of conductive polypyrrole (PPy) were formed electrochemically from aqueous sulfuric acid. The films showed good electrocatalytic properties towards hydrogen evolution (h.e.r) from alkaline solutions on planar and packed-bed iron electrodes. Current–potential relations were measured at various temperatures and KOH concentrations on Fe, Ni and Fe/PPy planar electrodes. The current was found to be constant during 40 h of operation. SEM micrographs showed no difference in the morphology before and after this period. The activation energy for h.e.r. was found to be 50.2, 58.5 and 33.4 kJ mol^–1 for Fe, Ni and Fe/PPy planar electrodes, respectively. The results showed that Fe/PPy can be used to produce hydrogen at both ambient and relatively high temperatures 70 C. The polypyrrole coating on iron screens was found to reduce the potential required to sustain a specific rate of hydrogen generation and, hence, the energy consumed during the process.     

Automated nuclei segmentation of malignant using level sets

Segmentation of objects from a noisy and complex image is still a challenging task that needs to be addressed. This article proposed a new method to detect and segment nuclei to determine whether they are malignant or not (determination of the region of interest, noise removal, enhance the image, candidate detection is employed on the centroid transform to evaluate the centroid of each object, the level set [LS] is applied to segment the nuclei). The proposed method consists of three main stages: preprocessing, seed detection, and segmentation. Preprocessing stage involves the preparation of the image conditions to ensure that they meet the segmentation requirements. Seed detection detects the seed point to be used in the segmentation stage, which refers to the process of segmenting the nuclei using the LS method. In this research work, 58 H&E breast cancer images from the UCSB Bio‐Segmentation Benchmark dataset are evaluated. The proposed method reveals the high performance and accuracy in comparison to the techniques reported in literature. The experimental results are also harmonized with the ground truth images.     

An OTA gain enhancement technique for low power biomedical applications

The performance requirement of an operational trans-conductance amplifier (OTA) for the high gain and low power neural recording frontend has been addressed in this paper. A novel split differential pair technique is proposed to improve the gain of the OTA without any additional bias current requirements. The design demonstrates a significant performance enhancement when compared to existing techniques, such as gain-boosting and recycling. A qualitative and quantitative treatment is presented to explore the impact of the split ratio on the performance parameters of gain, bandwidth, and linearity. A prototype implemented in TSMC 65 nm CMOS technology achieved 68 dB open loop-gain (13 dB higher than the conventional circuit) and a 17 kHz 3-dB bandwidth. A linearity of ? 62 dB has been achieved with 7 mV pk–pk signal at the input. The circuit operates from a 1 V supply and draws 0.6 uA static current. The prototype occupies 3300 um² silicon area.     

Free transverse vibration of elliptical plates of variable thickness with half of the boundary clamped and the rest free

First four frequencies have been computed for an elliptical plate half of whose boundary (y0) is clamped and the other half is free. The thickness of the plate is taken varying linearly with space coordinates. The Rayleigh–Ritz method has been used to obtain successive approximations utill convergence is achieved up to at least four significant figures. Results are tabulated for various values of the taper parameters. Three-dimensional mode shapes and the associated contour lines have been plotted in some selected cases. A table showing the rate of convergence with increasing order of approximation is given. Comparison has been made with known results in special cases. For the sake of completeness, results for the cases when the entire boundary is clamped or completely free are also reported.     

Weakly supervised semantic segmentation by iteratively refining optimal segmentation with deep cues guidance

Neural Computing and Applications - Weakly supervised semantic segmentation under image-level label supervision has undergone impressive improvements over the past years. These approaches can...     

Cyber Security and Privacy Issues in Industrial Internet of Things

The emergence of industry 4.0 stems from research that has received a great deal of attention in the last few decades. Consequently, there has been a huge paradigm shift in the manufacturing and production sectors. However, this poses a challenge for cybersecurity and highlights the need to address the possible threats targeting (various pillars of) industry 4.0. However, before providing a concrete solution certain aspect need to be researched, for instance, cybersecurity threats and privacy issues in the industry. To fill this gap, this paper discusses potential solutions to cybersecurity targeting this industry and highlights the consequences of possible attacks and countermeasures (in detail). In particular, the focus of the paper is on investigating the possible cyber-attacks targeting 4 layers of IIoT that is one of the key pillars of Industry 4.0. Based on a detailed review of existing literature, in this study, we have identified possible cyber threats, their consequences, and countermeasures. Further, we have provided a comprehensive framework based on an analysis of cybersecurity and privacy challenges. The suggested framework provides for a deeper understanding of the current state of cybersecurity and sets out directions for future research and applications.     

A Reliable NLP Scheme for English Text Watermarking Based on Contents Interrelationship

In this paper, a combined approach CAZWNLP (a combined approach of zero-watermarking and natural language processing) has been developed for the tampering detection of English text exchanged through the Internet. The third gram of alphanumeric of the Markov model has been used with text-watermarking technologies to improve the performance and accuracy of tampering detection issues which are limited by the existing works reviewed in the literature of this study. The third-grade level of the Markov model has been used in this method as natural language processing technology to analyze an English text and extract the textual characteristics of the given contexts. Moreover, the extracted features have been utilized as watermark information and then validated with the attacked English text to detect any suspected tampering occurred on it. The embedding mechanism of CAZWNLP method will be achieved logically without effects or modifying the original text document to embed a watermark key. CAZWNLP has been implemented using VS code IDE with PHP. The experimental and simulation results using standard datasets of varying lengths show that the proposed approach can obtain high robustness and better detection accuracy of tampering common random insertion, reorder, and deletion attacks, e.g., Comparison results with baseline approaches also show the advantages of the proposed approach.     

A study of optical absorption in 9,10-anthraquinone crystals

Single crystals of 9,10-anthraquinone having dimensions 5 mm × 5 mm × 1.5 mm were grown from the melt using the Bridgeman technique. The starting material was purified by sublimation and zone-refining techniques in specially, designed crystal-growth tubes. The crystals were transparent and yellow in colour, and could be cleaved easily along ab-, bc-planes and poorly along the ac-planes of the crystal. Thin layer chromatography of the final crystals was performed, and no impurity was detected in these crystals by this technique. The cleaved crystals were found to have a surface photocurrent of 10^–11 A, which increased non-linearly with the increasing voltage at room temperature. This is attributed to the formation of triplets in the bulk of the crystal which migrate and dissociate at the surface of the crystal. The optical absorption spectrum in benzene and ether solutions were found to exhibit similar behaviour in the visible range, i.e. 320–450 nm. From the optical absorbance data, the optical band gap was found to be 3.4 eV.