Effects of cold plasma on the color parameters of Hyssop (Hyssopus officinalis L.) using color imaging instrumentation and spectrophotometer

This research was conducted to evaluate the effects of cold atmospheric plasma treatment on the color of Hyssop (Hyssopus officinalis L.) and also to compare the usage of the spectrophotometer vs the color imaging instrumentation for the evaluation of the treatment on the color parameters. The experiments were investigated at different treatment times of 1, 5, and 10 minutes and the voltage values of 17, 20, and 23 kV. Possible changes of color were evaluated by using CIE L*a*b* values obtained with HunterLab colorimeter and CIE L*a*b* values obtained with a digital still camera (DSC) using digital image processing (MATLAB software). The values of L*, a*, and b* of the samples were obtained using both the methods. The results revealed that the L*, a*, and b* values of the treated Hyssop samples changed with increasing the treatment time and the voltage applied. Evaluating the interaction effects revealed that there was a significant difference in the (−a^*/b^* ) ratio. In addition, the results showed that the effects of all variables on the color parameters were significantly different in the case of the DSC using digital image processing. However, these effects were not significantly different using HunterLab colorimeter except for time variable and interaction effects of a* and (−a^*/b^* ) ratio. The lightest green color and the maximum chlorophyll content loss were observed for 23 kV applied over 10 minutes. Based on the results, the digital image processing can be used as a practical tool to study the variations at the color of dried Hyssop leaves after cold plasma treatment.     

The effects of surface-modified graphene nanoplatelets on the sliding wear properties of basalt fibers-reinforced epoxy composites

Possessing unique designs and properties absent in conventional materials, nanocomposites have made a remarkable imprint in science and technology. This is particularly true regarding the polymer matrix composites when they are further reinforced with nanoparticles. In this study, the effects of different weight percentages (0, 0.1, 0.2, 0.3, 0.4, and 0.5) of surface-modified graphene nanoplatelets (GNPs) on the microhardness and wear properties of basalt fibers/epoxy composites were investigated. The GNPs were surface modified by silane, and the composites were made by the hand lay-up method. The wear tests were conducted under two different loads of 20 and 40 N. The best wear properties were achieved at 0.3 wt % GNPs as a result of the GNPs' self-lubrication property and the formation of a stable transfer/lubricating film at the pin and disk interface. Moreover, the friction coefficient was lower at the higher normal load of 40 N. The microscopic studies by FESEM and SEM showed that the presence of GNPs up to 0.3 wt % led to the stability of the transfer/lubricating film by enhancing the adhesion of the basalt fibers to the epoxy resin. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47986.     

Equilibrium and kinetic studies of azo dye (Basic Red 18) adsorption onto montmorillonite: Numerical simulation and laboratory experiments

Adsorption of BR 18 dye onto nano-clay adsorbent was investigated. Nano-clay was characterized by using FTIR, SEM, TEM, XRD and BET analysis. The percent removal increased by increasing nano-clay dose, while pH and stirring speed had no significant effect on the adsorption rate. It was observed that the uptake of dye onto nano-clay initially increased rapidly, and then decreased slowly until the equilibrium was reached. The adsorption capacity rose with an increase in temperature. Moreover, the adsorption kinetics was very fast and followed a pseudo second-order. The intra-particle diffusion was observed to be the rate-controlling step. In addition, equilibrium data fitted well with the Langmuir adsorption model. This paper also presents a numerical simulation incorporating the second-order kinetic expression using COMSOL Multiphysics software. The numerical modelling results and the experimental data were in excellent agreement.     

Suicidality as a function of impulsivity, callous–unemotional traits, and depressive symptoms in youth.

Suicidality represents one of the most important areas of risk for adolescents, with both internalizing (e.g., depression, anxiety) and externalizing–antisocial (e.g., substance use, conduct) disorders conferring risk for suicidal ideation and attempts (e.g., Bridge, Goldstein, & Brent, 2006). However, no study has attended to gender differences in relationships between suicidality and different facets of psychopathic tendencies in youth. Further, very little research has focused on disentangling the multiple manifestations of suicide risk in the same study, including behaviors (suicide attempts with intent to die, self-injurious behavior) and general suicide risk marked by suicidal ideation and plans. To better understand these relationships, we recruited 184 adolescents from the community and in treatment. As predicted, psychopathic traits and depressive symptoms in youth showed differential associations with components of suicidality. Specifically, impulsive traits uniquely contributed to suicide attempts and self-injurious behaviors, above the influence of depression. Indeed, once psychopathic tendencies were entered in the model, depressive symptoms only explained general suicide risk marked by ideation or plans but not behaviors. Further, callous–unemotional traits conferred protection from suicide attempts selectively in girls. These findings have important implications for developing integrative models that incorporate differential relationships between (a) depressed mood and (b) personality risk factors (i.e., impulsivity and callous–unemotional traits) for suicidality in youth. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Aliphatic polyurethane–montmorillonite nanocomposite coatings: Preparation,characterization, and anticorrosive properties

Polyurethane (PU)–clay nanocomposite coatings were prepared by a sonication method. The stability and morphology of these coatings was characterized by turbidometry, X‐ray diffraction, and transmission electron microscopy. The anticorrosive properties of these coatings were investigated by salt‐spray and electrochemical impedance spectroscopy methods. According to the results, dispersed nanoclay layers in the matrix of the nanocomposite coating compositions led to superior anticorrosive characteristics compared to those of pure PU coatings. The best results were obtained with coatings containing about 5 wt % clay. The resistance of the coating containing 5% clay was about 9.002 GΩ after 225 days of immersion in a 3.5 wt % NaCl solution, whereas it was only 97 kΩ for the pure PU coating. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

利用混合信号FPGA推动临床医疗应用设备的发展

描述了混合信号FPGA在临场医疗设备中的应用,并以血液透析仪为例加以说明。     

Experimental comparison of classical PID and model-free control: Position control of a shape memory alloy active spring

Shape memory alloys (SMA) are being more frequently integrated into engineering applications. These materials with their shape memory effect enable the simplification of mechanisms and the reduction in size of actuators. SMA parts can easily be activated by Joule effect but their modeling and consequently their control remains difficult. It is principally due to their non-linear hysteretic thermomechanical behavior. Most of successful control strategies applied to SMA actuators are not often suitable for industrial applications: they are particularly heavy and use the Preisach model or neural networks to model the hysteretic behavior of these materials; this kind of model is difficult to identify and to use in real time. This paper deals with an application of the new framework of model-free control (MFC) of an SMA-spring based actuator. This control strategy relies on new results for fast derivative estimation of noisy signals. Their main advantages are: its simplicity and its robustness. Experimental results and comparisons with PI control are presented that demonstrate the efficiency of this new control strategy.     

Fabrication,characterization and evaluation of the effect of PLGA and PLGA–PEG biomaterials on the proliferation and neurogenesis potential of human neural SH-SY5Y cells

In recent years with regard to the development of nanotechnology and neural stem cell discovery, the combinatorial therapeutic strategies of neural progenitor cells and appropriate biomaterials have raised the hope for brain regeneration following neurological disorders. This study aimed to explore the proliferation and neurogenic effect of PLGA and PLGA–PEG nanofibers on human SH-SY5Y cells in in vitro condition. Nanofibers of PLGA and PLGA–PEG biomaterials were synthesized and fabricated using electrospinning method. Physicochemical features were examined using HNMR, FT-IR, and water contact angle assays. Ultrastructural morphology, the orientation of nanofibers, cell distribution and attachment were visualized by SEM imaging. Cell survival and proliferation rate were measured. Differentiation capacity was monitored by immunofluorescence staining of Map-2. HNMR, FT-IR assays confirmed the integration of PEG to PLGA backbone. Water contact angel assay showed increasing surface hydrophilicity in PLGA–PEG biomaterial compared to the PLGA substrate. SEM analysis revealed the reduction of PLGA–PEG nanofibers' diameter compared to the PLGA group. Cell attachment was observed in both groups while PLGA–PEG had a superior effect in the promotion of survival rate compared to other groups (p < .05). Compared to the PLGA group, PLGA–PEG increased the number of Ki67⁺ cells (p < .01). PLGA–PEG biomaterial induced neural maturation by increasing protein Map-2 compared to the PLGA scaffold in a three-dimensional culture system. According to our data, structural modification of PLGA with PEG could enhance orientated differentiation and the dynamic growth of neural cells.     

The influence of non-carcinogenic petroleum-based process oils on tire compounds’ performance

High aromatic oils which have been widely used as process oils in tire the industry contain high concentrations of polycyclic aromatic hydrocarbons (PAHs). These aromatic compounds (PAHs) have proved to be carcinogenic as well as posing a threat to the environment. Since the beginning of 2010, the use of high aromatic process oils has been banned under the EU regulation 1907/2007 commonly called REACH (registration, evaluation, authorization and restriction of chemicals). The so-called regulation has given rise to challenges to the oil and tire industries in replacing high aromatic process oils with safer alternatives. In the present work, four types of low aromatic petroleum-based process oils, namely mild and high-viscosity naphthenic oils (LNAP and HNAP), treated distillate aromatic extract (TDAE) and mildly extracted solvate (MES), were investigated and their effect on plasticization and durability properties of two different low and high oil-extended tire formulations were evaluated. The compatibility of oils with rubber was investigated as well. The results showed that a number of properties such as abrasion resistance and tire rolling resistance were improved by using non-carcinogenic oils, while tire grip properties were declined. Considering oil–rubber compatibility, TDAE and MES were found to be more compatible with rubbers.