Bioactive and Physicochemical Properties of Persimmon as Affected by Drying Methods

In this study, the effects of three different drying methods (freeze drying, oven drying, and vacuum oven drying) on bioactive (total phenolics, total flavonoids, condensed tannin and total hydrolyzable tannin contents, antiradical activity, and antidiabetic activity) and some physicochemical (dry matter, ash, water activity (a _w ), color, protein, hydroxymethylfurfural, glucose and fructose content) properties of persimmon fruit were investigated. Simplex lattice mixture design methodology was applied to determine the best solvent mixture for the extraction of phenolics from the samples. It was found that the mixture of acetone:water at the ratio of 50:50 % (v/v) was the best solvent mixture for the extraction. The persimmon powder sample obtained from freeze drying showed significantly (p <0.05) higher bioactivity values than oven- and vacuum-oven-dried samples. Antiradical activity changed significantly depending on the drying method employed and it was superior in freeze-dried samples than that of the other drying methods.     

A data-driven digital-twin prognostics method for proton exchange membrane fuel cell remaining useful life prediction

Prognostics and health management of proton exchange membrane fuel cell (PEMFC) systems have driven increasing research attention in recent years as the durability of PEMFC stack remains as a technical barrier for its large-scale commercialization. To monitor the health state during PEMFC operation, digital twin (DT), as a smart manufacturing technique, is applied in this paper to establish an ensemble remaining useful life prediction system. A data-driven DT is constructed to integrate the physical knowledge of the system and a deep transfer learning model based on stacked denoising autoencoder is used to update the DT with online measurement. A case study with experimental PEMFC degradation data is presented where the proposed data-driven DT prognostics method has applied and reached a high prediction accuracy. Furthermore, the predicted results are proved to be less affected even with limited measurement data.     

Ternary nanocomposite of SiO 2 /Fe 3 O 4 /Multi-Walled Carbon Nanotubes for Efficient Adsorption of Malachite Green: Response Surface Modeling,Equilibrium Isotherms and Kinetics

In the work, synthesis and application of the ternary nanocomposite of SiO2/Fe3O4/multi-walled carbon nanotubes (SFCNT) for adsorptive removal of malachite     

Thermal optimization of solar dish collector for indirect vapor generation

This work presented the performance analysis of a solar parabolic concentrator prototype. The purpose of this paper is to achieve most quantity of vapor production with different water flows. The principal component of the solar concentrator is a new absorber concept that absorbs reflected solar rays and transports it to a heat exchanger in order to generate vapor. Climatic conditions, inlet/outlet oil temperatures of the tubular solar heat exchanger, water tank temperature, and inlet/outlet water temperatures of the mixed heat exchanger were recorded experimentally during three days in November 2018. The absorbed energy, losses energy, concentrated energy, and vapor heat energy of the system were determined. Results of this work, the solar system provides thermal energy efficiency varied from 60% to 70% and a concentration factor around 350 for three water mass flow rates. In this experiment, the optimum value of vapor mass is 6 kg/h with 0.016 kg/s of water flow. Consequently, to achieve the most quantity of vapor, the water flow should be decreased.     

A cluster-based trust-aware routing protocol for mobile ad hoc networks

Routing protocols are the binding force in mobile ad hoc network (MANETs) since they facilitate communication beyond the wireless transmission range of the nodes. However, the infrastructure-less, pervasive, and distributed nature of MANETs renders them vulnerable to security threats. In this paper, we propose a novel cluster-based trust-aware routing protocol (CBTRP) for MANETs to protect forwarded packets from intermediary malicious nodes. The proposed protocol organizes the network into one-hop disjoint clusters then elects the most qualified and trustworthy nodes to play the role of cluster-heads that are responsible for handling all the routing activities. The proposed CBTRP continuously ensures the trustworthiness of cluster-heads by replacing them as soon as they become malicious and can dynamically update the packet path to avoid malicious routes. We have implemented and simulated the proposed protocol then evaluated its performance compared to the clustered based routing protocol (CBRP) as well as the 2ACK approach. Comparisons and analysis have shown the effectiveness of our proposed scheme.     

Effect of temperature on rheological characteristics of molasses: Modeling of apparent viscosity using Adaptive Neuro - Fuzzy Inference System (ANFIS)

In this study, the effect of temperature on the rheological characteristics of apricot and date molasses was studied separately. Rheological characteristics of both molasses were evaluated in the shear rate range of 0.1-100 s⁻¹ at different temperatures (10-40 °C). Power law model was used for the calculation of flow behavior index and consistency coefficients of molasses. Consistency coefficients of apricot and date molasses were in the range of 5.408-39.905 Pa sⁿ and 0.910-2.852 Pa sⁿ, respectively. Molasses samples showed a non-Newtonian flow behavior. The effect of temperature on apparent viscosity was described by Arrhenius equation and calculated activation energy at the shear rate of 54.2 s⁻¹ was 41.42 and 38.19 kJ/mol for apricot and date molasses, respectively. An efficient predictive model for apparent viscosity values of molasses was constructed using Adaptive Neuro - Fuzzy Inference System (ANFIS) and this model showed satisfactory prediction with high coefficient of determination (0.979-0.999) and low root mean squared error (0.12-0.46).     

Evaluating location management schemes for third generation mobile networks

Several strategies have been proposed recently to improve the performance of the IS-41 location management scheme. A forwarding pointers' strategy and a built-in memory strategy are proposed to reduce the signaling cost for location update and improve the IS-41 location update procedure. In this paper, we present a performance analysis of each strategy in an arbitrary time interval. In this analysis, users are classified by their call to mobility ratio which is defined as the call arrival rate divided by the mobility rate. We evaluate each of these strategies using this call to mobility ratio in order to come up with a set of recommendations that determine when each strategy is beneficial and for which class of users. We provide also a simplified analysis of the database loads generated by each strategy.     

Free markets and the marriage market: structural adjustment,gender relations,and working conditions among Dominican women workers

The relationship between economic conditions and marriage patterns in the Dominican Republic is analyzed using data collected in 1994 on women working in a free-trade zone. The author concludes that changes associated with structural adjustment appear to have contributed to a deterioration of the job market and a greater prevalence of female-headed households. It is shown that "structural adjustment increases the need for women to work, because of cuts in government programs, declining real wages, growing inflation, and a deterioration in male employment, which weakens the man's role as principal breadwinner and increases the importance and visibility of women's contribution to the household economy. This change in the gender composition of the labor force has encouraged some women to resist marriage and/or remarriage because the ?marriage market' of eligible men willing and able to support a family has been reduced, contributing to greater marital instability."