Synergistic effect of high-intensity ultrasound and β-cyclodextrin treatments on browning control in apple juice

This work evaluated the synergistic effects of combined high-intensity ultrasound (HIU) with β-cyclodextrin (β-CD) treatments on inhibiting browning of apple juice and explored the mechanism through simulation system. The combined treatment of 300 W HIU with 0.006 g mL⁻¹ β-CD had a synergistic impact on maintaining juice colour, resulting in a 39.06% reduction in browning degree, only a 36.64% decrease in total phenolic content, and a 17.82% reduction in PPO activity. The inhibition of enzymatic browning in simulated system revealed that HIU suppressed the enzyme (Polyphenol oxidase, PPO) and β-CD inhibited enzyme (PPO) and embedded substrate (polyphenol). The results of spectroscopic analysis showed that the particle-size distribution of PPO narrowed, the content of α-helix in the secondary structure increased, the fluorescence intensity increased, and the maximum wavelength was red-shifted after HIU and β-CD treatment. Changes in structure could further result in PPO activity loss. Hence, the combined treatment could synthetically alleviate the browning of apple juice.     

Polymer and nanobelt derived nanomaterials: opening doors to revolutionary stadia

ABSTRACT

The state-of-the-art article presents concepts of nanobelt nanofiller, inimitable properties of derived polymeric nanocomposite, applications, and outlook on challenges to gain next generation high-performance materials. Nanobelt is a one-dimensional nanostructured nanomaterial. Owing to minuscule size and high surface area, nanobelt possesses unique structural, optical, electronic, mechanical, and thermal characteristics. Nanobelt exists in various forms such as carbon nanobelt, polymer nanobelt, and inorganic. These nanobelts have been used to develop polymer/nanobelt nanocomposites. Homogeneous dispersion of nanobelt in polymer matrices is desirable to enhance the characteristics of polymer/nanobelt nanocomposite. Consequently, innovations in design, fabrication, and properties of various polymer/nanobelt nanocomposite are summarized. Applications of polymer/nanobelt nanocomposite are reviewed for Li-ion battery, supercapacitor, sensor, membrane, and biomedical arenas.     

Eco-friendly electronics,based on nanocomposites of biopolyester reinforced with carbon nanotubes: a review

ABSTRACT

Fabrication of electronic materials from nanocomposite of biopolyesters reinforced with carbon nanotubes can be regarded as the effective alternative for conventional nanocomposites consisting of non-biodegradable polymers. Commercial availability of biopolyester-based nanocomposites is limited because of their high cost compared to other polymers, but the factor of their compostable nature is worthless for environmental protection. Such nanocomposites have potential applications in biodegradable sensors, EMI materials, etc. In this review, the current progress of biopolyester/CNTs nanocomposites in the field of biodegradable electronics is reviewed and also the impact of CNTs dispersion on electrical, thermal and mechanical properties of eco composites is stipulated.     

An efficient and noise resistive selective image encryption scheme for gray images based on chaotic maps and DNA complementary rules

A novel image encryption algorithm in streaming mode is proposed which exhaustively employs an entire set of DNA complementary rules alongwith one dimensional chaotic maps. The proposed algorithm is highly efficient due to encrypting the subset of digital image which contains 92.125 % of information. DNA addition operation is carried out on this MSB part. The core idea of the proposed scheme is to scramble the whole image by means of piecewise linear chaotic map (PWLCM) followed by decomposition of image into most significant bits (MSB) and least significant bits (LSB). The logistic sequence is XORed with the decoded MSB and LSB parts separately and finally these two parts are combined to get the ciphered image. The parameters for PWLCM, logistic map and selection of different DNA rules for encoding and decoding of both parts of an image are derived from 128-bit MD5 hash of the plain image. Simulated experimental results in terms of quantitative and qualitative ways prove the encryption quality. Efficiency and robustness against different noises make the proposed cipher a good candidate for real time applications.     

Correction on link relative based approach to CUSUM chart

Link relative-based approach was used in an article (see reference 1) to enhance the performance of the cumulative sum (CUSUM) control chart. This technique involves the use of firstly, the link relative variable to convert the process observations in a relative to the mean form and secondly, optimal constants to define a new variable which is used as the plotting statistic of the link relative CUSUM chart. In this article, it is proven through simulation study that the optimal constants with fixed values, as reported in the aforementioned article, give different results. Instead, if the regression technique is used, then the same results will be obtained.     

A genetic algorithm approach to determine the sample size for attribute control charts

Determining the sample size for control charts (CCs) is generally an important problem in the literature. In this paper, Kaya and Engin’s [?. Kaya, O. Engin, A new approach to define sample size at attributes control chart in multistage processes: an application in engine piston manufacturing process, Journal of Materials Processing Technology 183 (2007) 38-48] model based on minimum cost and maximum acceptance probability to determine the sample size for attribute control charts (ACCs), and solved by genetic algorithms (GAs) with linear binary representation structure, is handled to solve it by a linear real-valued representation. A new chromosome structure is also suggested to increase the efficiency of GAs. The performance of GAs depends on mutation and crossover operators, and their ratios. To determine the most appropriate operators, five different mutation and crossover operators are used and they are compared with each other. An application in a motor engine factory is illustrated. u-Control charts are constructed with respect to the sample size determined by GA in the model. The piston production stages in this factory are monitorized using the obtained control charts.     

Exploring pre-service teachers' beliefs about using Web 2.0 technologies in K-12 classroom

This qualitative study explored pre-service teachers' behavioral, normative, and control beliefs regarding their intentions to use Web 2.0 technologies in their future classrooms. The Theory of Planned Behavior (TPB) was used as the theoretical framework (Ajzen, 1991) to understand these beliefs and pre-service teachers' intentions for why they want to use Web 2.0 technologies. According to Ajzen's TPB, the behavioral beliefs are based on attitude toward outcomes or consequences of using Web 2.0, the normative beliefs depend on social support and social pressure to use Web 2.0, and the control beliefs lay the foundation of perceived behavioral control over using Web 2.0 in a classroom. Data were collected from open-ended survey questions (n = 190), semi-structured interviews (n = 12) and end of semester reflections (n = 12). Findings suggest that pre-service teachers' intentions to use Web 2.0 technologies are related to their beliefs about the value of these technologies for improving student learning and engagement, its ease of use (behavioral beliefs), its ability to meet the needs/expectations of digital age students (normative beliefs), the participants' high self-efficacy in use, and its potential for affording students anytime/anywhere access to learning and interaction (control beliefs). From these results, we recommend that teacher educators should target these beliefs within teacher development programs to prepare pre-service teachers for successful use of Web 2.0 technologies in their future K-12 classrooms.     

Adaptive Q control for tapping-mode nanoscanning using a piezoactuated bimorph probe

A new approach, called adaptive Q control, for tapping-mode atomic force microscopy (AFM) is introduced and implemented on a homemade AFM setup utilizing a laser Doppler vibrometer and a piezoactuated bimorph probe. In standard Q control, the effective Q factor of the scanning probe is adjusted prior to the scanning depending on the application. However, there is a trade-off in setting the effective Q factor of an AFM probe. The Q factor is either increased to reduce the tapping forces or decreased to increase the maximum achievable scan speed. Realizing these two benefits simultaneously using standard Q control is not possible. In adaptive Q control, the Q factor of the probe is set to an initial value as in standard Q control, but then modified on the fly during scanning when necessary to achieve this goal. In this article, we present the basic theory behind adaptive Q control, the electronics enabling the online modification of the probe's effective Q factor, and the results of the experiments comparing three different methods: scanning (a) without Q control, (b) with standard Q control, and (c) with adaptive Q control. The results show that the performance of adaptive Q control is superior to the other two methods.     

Comparative Review on Structure,Properties, Fabrication Techniques,and Relevance of Polymer Nanocomposites Reinforced with Carbon Nanotube and Graphite Fillers

Owing to their remarkable electrical, mechanical, thermal, catalytic, and optical properties as well as their unique structure, carbon nanotubes and graphite have been exploited to produce high performance and multifunctional composites. The resultant composites are differentiated on the basis of their properties to meet various applications. In the framework of this review article, we have mainly focused on the preparation, structure, and properties of two families of composite materials with an emphasis on the differences between them. Moreover, the current challenges, future prospectives, and applications of carbon nanotubes- and graphite-based materials in sensors and in photovoltaic and energy storage devices (Li-ion battery) have been discussed.