Synthesis and comparison of crosslinked peptide nanoparticles based on diphenylalanine derivatives

Self‐assembly is a mechanism that creates novel nanomaterials with amplified properties but with stability challenges. In this report, highly stable and biocompatible anionic zwitterionic diphenylalanine nanoparticles (ZFFNPs), which are novel for the literature, are demonstrated. ZFF was crosslinked with glutaraldehyde (GA) and self‐assembled into nanoparticles in a self‐assembly mechanism like that for diphenylalaninamide nanoparticles (FFANPs). Also, ZFFNPs were compared with FFANPs in aspects of morphology, surface charge, stability, and cytotoxicity. ZFFNPs demonstrate a spherical morphology and homogenicity like FFANPs, but while ZFFNPs have negative surface groups (carboxyl), FFANPs contain polar surface groups (amide). While ZFFNPs exhibit a high stability in extremely acidic environments (pH 3–5), AFFNPs show stability in a wide pH range (pH 4–10). Both NPs are nontoxic and biocompatible. These novel anionic ZFFNPs have great promise for potential utilization in biomedical applications. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 45930.     

Kinetic modeling of benzoic acid esterification using functionalized silica gel

In our study, we synthesized two types of solid acid catalysts. Silica gel with a particle size of 0.063–0.2?mm was silanized first at reflux (S1) and second at room temperature (S3) using (3-mecaptopropyl)trimethoxysilane in toluene, and further oxidized with H₂O₂, and methanesulfonic acid. Characterization of the synthesized catalysts was performed using adsorption/desorption of nitrogen (BET), Fourier transform infrared spectroscopy, scanning electron microscopy, and thermogravimetric analysis. Both catalysts were used in esterification reactions of benzoic acid with methanol. All reactions were performed in a batch reactor at temperatures, ??=?55, 60, and 64.5°C, stirrer speed, f_s?=?400?min^?1, and catalyst loading, m?=?5, 10, and 15?g. The concentration of produced methylbenzoate was determined by HPLC. The study was supplemented with a kinetic study of the reaction. First-order kinetics was confirmed for this esterification reaction. Using catalyst S1, higher conversion was reached, while catalyst S3 is much more suitable for reuse.     

Pulsed ultrasound-assisted extraction of natural antioxidants from mandarin (Citrus deliciosa Tenore) leaves: Experimental and modeling study

Pulsed ultrasound-assisted extraction (PUAE) of flavonoids and polyphenols from mandarin (Citrus deliciosa Tenore) leaves was examined. The response surface methodology (RSM) via face-centered central composite design (FCCD) was used to investigate the effects of extraction time (15–75?min), output amplitude (30–70%), and pH (4–10) to optimize the extraction process. The total phenolic material (TPM) and the total flavonoid material (TFM) and also the consumed energy of horn were measured as responses. Additionally, calorimetric calculations were done to evaluate the ultrasound energy dissipated into the solution. The calculated quadratic models were highly significant (p?R²) of 0.9722, 0.9805, and 0.9983. The results of the present study suggest that 65?min, 68.72?min, 15.00 extraction time, 61%, 59%, and 30% of ultrasound amplitude and 4, 6.7, and 4 pH of solution should be considered as optimal extraction conditions to get the optimum TPM (37.845?mg-GAE/g-DL), TFM (10.709?mg-CE/g-DL), and energy consumption (6130.275 Joule) for PUAE of mandarin leaves, respectively.     

Voltage difference transresistance amplifier and its application: floating FDNR simulator circuit

In this article, a new active building component with electronically tunable transresistive block, voltage difference transresistance amplifier, and its floating frequency dependent negative resistor simulator circuit application is presented. The simulator circuit is shown to operate using single active building block with two grounded passive components, to be electronically tunable over its value which is controlled by an independent current source, not to require any conditions of component matching and to have good sensitivity performance with respect to tracking errors. To examine functionality of the design, a CRD band-pass filter example is given.

Numerous simulation program with integrated circuit emphasis (SPICE) simulations are performed and depicted through the article to verify validity of the study. Taiwan semiconductor manufacturing company (TSMC) 0.18 µm complementary metal oxide semiconductor technology parameters are used through simulations.     

Optimal Power Allocation in an Amplify-and-Forward Untrusted Relay Network with Imperfect Channel State Information

The characteristics of the wireless medium create difficulty to shield the data transmission from unauthorized recipients. In this paper, power optimization in an amplify-and-forward untrusted relay network is presented, using cooperative jamming transmission to prevent the untrusted relay from intercepting the confidential signals. Considering imperfect channel estimation error at the destination, an optimal power allocation (OPA) is designed to maximize the achievable secrecy rate for the network. Simplified OPA is derived for high signal-to-noise ratio regime with imperfect CSI and the ergodic secrecy rate is also analyzed to evaluate the achievable average secrecy rate for different scenarios as a common performance metric. The numerical results show that when the error of CSI is considered, the proposed OPA generates limited and acceptable degradation on the secrecy rate.     

钻杆检测设备的国产化改造

针对胜利油田渤海钻井管具公司引进美国OEM公司的钻杆室内检测线在使用过程中出现的问题,在认真分析引进设备硬软件的基础上,对该设备进行了国产化改造。不仅保持了原设备的性能指标,而且增加了管体壁厚检测功能,提高了检测信号量化能力,实现了钻杆的科学有效的分级管理。     

Learning Intelligent Behavior in a Non-stationary and Partially Observable Environment

Individual learning in an environment where more than one agent exist is a chal-lengingtask. In this paper, a single learning agent situated in an environment where multipleagents exist is modeled based on reinforcement learning. The environment is non-stationaryand partially accessible from an agents' point of view. Therefore, learning activities of anagent is influenced by actions of other cooperative or competitive agents in the environment.A prey-hunter capture game that has the above characteristics is defined and experimentedto simulate the learning process of individual agents. Experimental results show that thereare no strict rules for reinforcement learning. We suggest two new methods to improve theperformance of agents. These methods decrease the number of states while keeping as muchstate as necessary.     

米糠蛋白及米糠纤维质残渣在烘焙食品中应用的探讨

本文探讨了从脱脂米糠中所制取的米糠蛋白及纤维质残渣,作为蛋白强化剂及纤维素强化剂应用于烘焙食品中,效果比较理想。     

Multi-time scale zero-sum differential games with perfect state measurements

We obtain necessary and sufficient conditions for the existence of approximate saddle-point solutions in linear-quadratic zero-sum differential games when the state dynamics are defined on multiple (three) time scales. These different time scales are characterized in terms of two small positive parameters ₁, and ₂, and the terminology approximate saddle-point solution is used to refer to saddle-point policies that do not depend on ₁ and ₂, while providing cost levels withinO(₁) of the full-order game. It is shown in the paper that, under perfect state measurements, the original game can be decomposed into three subgames-slow, fast and fastest, the composite saddle-point solution of which make up the approximate saddle-point solution of the original game. Specifically, for the minimizing player, it is necessary to use a composite policy that uses the solutions of all three subgames, whereas for the maximizing player, it is sufficient to use a slow policy. In the finite-horizon case this slow policy could be a feedback policy, whereas in the infinite-horizon case it has to be chosen as an open-loop policy that is generated from the solution and dynamics of the slow subgame. These results have direct applications in theH -optimal control of three-time scale singularly perturbed linear systems under perfect state measurements.Research supported in part by the National Science Foundation under Grant ECS 91-13153, and in part by the U.S. Department of Energy under Grant DE-FG-02-88-ER-13939. This paper is dedicated to the memory of John Breakwell.