Synthesis, Characterization, and Properties of Mononuclear and Dinuclear Ruthenium(II) Complexes Containing Phenanthroline and Chlorophenanthroline

The study of photophysical and photochemical properties of ruthenium complexes is of great interest for fundamental practical reasons. Ruthenium complexes have been investigated for use in artificial photosynthesis. This paper deals with the synthesis and spectroscopic investigation of custom-designed ruthenium complexes containing phenanthroline and chloro-phenanthroline ligands. These complexes maybe useful for biological electron-transfer studies. The heteroleptic ruthenium monomer complex Ru(phen)2(Cl-phen) (where phen = 1,10-phenanthroline and Cl-phen=5-chloro-1,10-phenanthroline) was prepared in a two-step procedure previously developed in our laboratory. This monomer complex was used to prepare the ruthenium homometallic dimer complex, (phen)2Ru(phen-phen)Ru(phen)2, by utilizing the Ni-catalyzed coupling reaction. Both complexes were purified by extensive column chromatography. The identity and the integrity of the monomer complex were confirmed by elemental analysis. The calculated and the experimental values for the elemental analysis were in good agreement for the monomer complex. UV/Vis absorption spectroscopy, emission spectroscopy, and cyclic voltammetry were used to investigate the properties of both the complexes

A Privacy Preserving Framework for RFID Based Healthcare Systems

RFID (Radio Frequency IDentification) is anticipated to be a core technology that will be used in many practical applications of our life in near future. It has received considerable attention within the healthcare for almost a decade now. The technology’s promise to efficiently track hospital supplies, medical equipment, medications and patients is an attractive proposition to the healthcare industry. However, the prospect of wide spread use of RFID tags in the healthcare area has also triggered discussions regarding privacy, particularly because RFID data in transit may easily be intercepted and can be send to track its user (owner). In a nutshell, this technology has not really seen its true potential in healthcare industry since privacy concerns raised by the tag bearers are not properly addressed by existing identification techniques. There are two major types of privacy preservation techniques that are required in an RFID based healthcare system—(1) a privacy preserving authentication protocol is required while sensing RFID tags for different identification and monitoring purposes, and (2) a privacy preserving access control mechanism is required to restrict unauthorized access of private information while providing healthcare services using the tag ID. In this paper, we propose a framework (PriSens-HSAC) that makes an effort to address the above mentioned two privacy issues. To the best of our knowledge, it is the first framework to provide increased privacy in RFID based healthcare systems, using RFID authentication along with access control technique

Studies of Zeolite Entrapped Ruthenium Polypyridine Complexes

There is an intense interest in designing molecular systems which will absorb visible sunlight, initiate an electron transfer process, and ultimately convert the solar energy to useful chemical energy of fuels such as hydrogen produced from water. The zeolite-entrapped polypyridine complexes of divalent ruthenium hold promise as efficient photocatalysts for net charge separation and such efficiencies are further enhanced by organized incorporation of donor and acceptor components. This paper deals with the synthesis and spectroscopic investigation of zeolite-entrapped ruthenium polypyridine complexes which may be useful in the development of solar energy conversion schemes. The sensitizer molecules, such as Ru(bpy)3 2+ (bpy = 2,2-bipyridine), are entrapped within the supercages of structurally well-defined zeolite Y by the so called ship in a bottle synthesis, which eliminates the undesirable diffusion of the complex and inhibits the wasteful back-electron transfer reaction. This complex has a dimension of ~12A, which is too large to introduce through a 7.4 A window opening. Once the complex is formed in the supercage, it cannot escape through the windows and is effectively entrapped within the supercage. The zeolite-entrapped ruthenium complexes are characterized by diffuse reflectance, electronic absorption, electronic emission, and resonance Raman (RR) spectroscopy, as well as excited state lifetime measurements. A brief summary of the synthetic and characterization procedure of the zeolite-entrapped ruthenium polypyridine complexes is presented here. Emphasis is given on the author\u27s work, although a discussion of some of the important contributions made by other workers is also included. This study clearly demonstrates that entrapment of ruthenium complex within the supercage of Y-zeolite can alter inherent photophysical properties of the complex in an advantageous manner

Optimal Sizing and Power Management Strategies of Islanded Microgrids for Remote Electrification Systems

Over the past few years, electrification of remote communities with an efficient utilization of on-site energy resources has entered a new phase of evolution. However, the planning tools and studies for the remote microgrids are considered inadequate. Moreover, the existing techniques have not taken into account the impact of reactive power on component sizes. Thus, this thesis concentrates on optimal sizing design of an islanded microgrid (IMG), which is composed of renewable energy resources (RERs), battery energy storage system (BESS), and diesel generation system (DGS), for the purpose of electrifying off-grid communities. Owing to the utilization of both BESS and DGS, four power management strategies (PMSs) are modeled upon analyzing the impacts of reactive power to chronologically simulate the IMG. In this work, two single-objective optimization (SOO) and two multiobjective optimization (MOO) approaches are developed for determining the optimal component sizes in an IMG. Chronological simulation and an enumeration-based search technique are adopted in the first SOO approach. Then, an accelerated SOO approach is proposed by adopting an improved piecewise aggregate approximation (IPAA)-based time series and a genetic algorithm (GA). Next, an adaptive weighted sum (AWS) method, in conjunction with an enumeration search technique, is adopted in a bi-objective optimization approach. Finally, an elitist non-dominated sorting GA-II (NSGA-II) technique is proposed for MOO of the IMG by introducing three objective functions. The enumeration-based SOO approach ensures a global optimum, determines the optimal sizes and PMSs simultaneously, and offers a realistic solution. The accelerated SOO approach significantly reduces the central processing unit (CPU) time without largely deviating the life cycle cost (LCC). The bi-objective optimal sizing approach generates a large number of evenly spread trade-off solutions both in regular and uneven regions upon adopting the LCC and renewable energy penetration (REP) as the objective functions. Using the MOO approach, one can produce a diversified set of Pareto optimal solutions, for both the component sizes and PMSs, at a reduced computational effort. The effectiveness of the proposed approaches is demonstrated by simulation studies in the MATLAB/Simulink software environment

Muslim Immigrants in the Early 20th Century America: Some Have Forsaken, While Others Preserved Their Identity

This article explores the challenges that immigrant Muslims faced in pre-1965 America in their efforts to find acceptance within the American host society. To understand this phenomenon I have used the ethnographic methods of research and collecting data focusing on a Palestinian Muslim family (Abukhdeir) who came to America in 1910 and settled in Provo, Utah as Kader family and adopted Mormonism. As such, this article demonstrates that the identity crisis of early generation Muslim immigrants resulted in the following consequences: (1) Who assimilated to the prevailing American melting pot culture of mainstream society, including converting to American religions; (2) Who did not assimilate, rather escaped the pressure of assimilation by returning to their home countries and resettled there without coming back to live in America; and (3) Who both assimilated and preserved their Islamic identities, as they were the children of returnees, which coincided with the wake of multiculturalism in America in the late 1960s. These grown-up children of the returnees then shared the new process of assimilation into multicultural America, replacing melting pot culture, and affiliated with the fastest-growing Muslim communities

Synthesis, Characterization, and Properties of Homometallic Dinuclear Ruthenium Complex Containing Chloro-Phenanthroline and Bipyridine

This paper deals with the synthesis and spectroscopic investigation of homometallic dinuclear ruthenium(II) complex containing chlorophenanthroline and bipyridine ligands. This bimetallic ruthenium polypyridine complex may be useful for biological electron transfer studies. Heteroleptic ruthenium monomer complex Ru(bpy)2(Cl-phen) (where bpy = 2,2’-bipyridine and Cl-phen = 5-chloro- 1,10-phenanthroline) was prepared in a two step procedure previously developed in our laboratory. This monomer complex was used to prepare the ruthenium dimer complex, (bpy)2Ru(phen-phen)Ru(bpy)2, by utilizing the Ni-catalyzed coupling reaction. Both the complexes were purified by column chromatography. The identity and the integrity of the complexes were confirmed by elemental analysis as well as mass spectroscopy. The calculated and the experimental values for the elemental analysis were in good agreement. The calculated and experimental molar masses of the dimer complex were also identical. UV/Vis absorption, emission spectroscopic method, and cyclic voltammetric method were used to investigate the properties of the dimer complex

Impact of 20-day strike in Polokwane Hospital (18 August - 6 September 2010)

Background. Doctors’ strikes have a negative effect on hospital performance indicators. Hospital mortality during such strikes is the most important indicator.Objective. To determine the effects of the 2010 strike on Polokwane Hospital.Methods. Information was collected from the Hospital Information System, Polokwane Hospital Casualty Department, wards and theatres.Results. During the 20-day strike, a total of 262 patients were  admitted to Polokwane Hospital, with 40 patients to the surgical department; 96 operations were performed in the hospital and 40 in the surgical department; and 50 deaths were reported in the hospital (8 deaths in the surgical department). During 20 days of a non-striking period in May 2010, there were 975 admissions to the hospital, with 125 to the surgical department. In the entire hospita l, 340 operations were performed, and 79 in the surgical department. For this period, 61 deaths were reported in the hospital and 12 in the surgical department.Conclusions. The total number of patients admitted to the hospital and the surgical department during the strike was significantly lower than during a non-striking situation. Total mortality during the strike in Polokwane Hospital decreased, compared with the normal situation, but it increased when judged against emergency cases. However, when mortality was qualified by the number of admissions, it showed a significant increase. Strikes seriously and significantly affect service delivery