Tin(II)-quercetin complex: Synthesis, spectral characterisation and antioxidant activity

The complex formation between quercetin (Q) and stannous chloride (SnCl₂·2H₂O) was studied using UV-visible, IR and ¹H NMR spectroscopic techniques. Spectroscopic data suggest that Q can chelate stannous cations through both 3-hydroxy-4-carbonyl and the 3′,4′-dihydroxyl (catechol) chelation sites. The antioxidant activity of the complex was evaluated using 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2′-azinobis 3-ethylbenzothiazoline-6-sulphonic acid (ABTS) diammonium salt and ferric reducing antioxidant power (FRAP) methods. It was shown that radical scavenging activity and ferric reducing potential of free Q was decreased after chelation of stannous cation.     

Reverse Link Performance of DS-CDMA Cellular Systems through Closed-Loop Power Control, Base Station Assignment, and Antenna Arrays in 2D Urban Environment

The interference reduction capability of antenna arrays, base station assignment, and the power control algorithms have been considered separately as means to increase the capacity in wireless communication networks. In this paper, we propose smart step closed-loop power control (SSPC) algorithm and base station assignment method based on minimizing the transmitter power (BSA-MTP) technique for direct sequence-code division multiple access (DS-CDMA) receiver in a 2D urban environment. This receiver consists of conjugate gradient adaptive beamforming and matched filter in two stages using antenna arrays. In addition, we study an analytical approach for the evaluation of the impact of power control error (PCE) on the DS-CDMA cellular systems. The simulation results indicate that the SSPC algorithm and the BSA-MTP technique can significantly improve the network bit error rate in comparison with conventional methods. Our proposed methods can also significantly save total transmit power and extend battery life in mobile units. In addition, we show that the convergence speed of the SSPC algorithm is faster than that of conventional algorithms. Finally, we discuss two parameters of PCE and channel propagation conditions (path-loss parameter and variance of shadowing) and their effects on the capacity of the system via some computer simulations.     

Fuzzy expert system for troubleshooting of the deodorizer unit in a palm oil refining plant

In this paper, a troubleshooting technique is developed to provide a sequence of necessary actions during deodorizer unit failure in a palm oil refinery. This paper introduces a fuzzy expert system that incorporates the knowledge of experienced plant workers in dealing with the complex problems of the palm oil deodorizer. The presented methodology uses both qualitative and quantitative data. Qualitative data are collected from several interview sessions with the technical staff in a palm oil refinery. Quantitative data are gathered from various sources, such as control and monitoring systems. The qualitative data are analyzed to discover the possible pattern of faults in the deodorizer failure. This tool can diagnose possible faults and provide a sequence of necessary actions when deodorizer failure occurs. The obtained results show the developed deodorizer troubleshooting tool is useful to guide plant workers/operators in diagnosing the possible faults and abnormalities during the troubleshooting process, as well as to provide field training for inexperienced staff.     

Biopolymer Nanovehicles for Oral Delivery of Natural Anticancer Agents

Cancer is the second leading cause of death throughout the world. Nature-inspired anticancer agents (NAAs) that are a gift of nature to humanity have been extensively utilized in the alleviation/prevention of the disease due to their numerous pharmacological activities. While the oral route is an ideal and common way of drug administration, the application of NAAs through the oral pathway has been extremely limited owing to their inherent features, e.g., poor solubility, gastrointestinal (GI) instability, and low bioavailability. With the development of nano-driven encapsulation strategies, polymeric vehicles, especially those with natural origins, have demonstrated a potent platform, which can professionally shield versatile NAAs against GI barricades and safely deliver them to the site of action. In this review, the predicament of orally delivering NAAs and the encapsulation strategy solutions based on biopolymer matrices are summarized. Proof-of-concept in vitro/in vivo results are also discussed for oral delivery of these agents by various biopolymer vehicles, which can be found so far from the literature. Last but not the least, the challenges and new opportunities in the field are highlighted.     

Design of Zn1−xCuxO Nanocomposite Ag-Doped as an Efficient Antimicrobial Agent

Journal of Inorganic and Organometallic Polymers and Materials - This study aims at the preparation of antimicrobial nanoparticles hybrid based on silver (Ag) doped Zn1?xCuxO. Zn1?xCuxO...