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The crystalline ZnO nanorods, grown on Si-substrate (100) at a low temperature using a hydrothermal process were used for modification of platinum electrode using PVC and THF for in order to test their chemosensor activity. The modified electrode can be used for selective nanomolar determination of guanine in aqueous media without any interference from other biomolecules. The prepared chemosensor has a lower detection limit of 40 nM for guanine, and a modification of the electrodes with ZnO nanorods increases the reproducibility by reducing the fouling effect caused by the oxidation of biomolecules on the electrode surface as the prepared electrode can be used for more than 30 consecutive scans and can be used for 5 days without any change in current intensity or sensitivity.

Although students in Introductory Information Systems courses are taught new technology concepts, the complexity and constantly changing nature of these technologies makes it challenging to deliver the concepts effectively. Aiming to improve students’ learning experiences, this research utilized the five phases of design science methodology to develop an experiment to solve a real-world problem, and then implemented it in an undergraduate classroom. As part of their classwork, students participated as subjects testing new information technologies to solve a real-world problem. They were asked to complete a questionnaire and answer questions in a focus group to assess the effectiveness of the technologies tested and determine whether the experience had added to the learning they gained from the course. The results revealed that the students were able to use the new technologies effectively and provide useful feedback to the company sponsoring the study, contributing to the release of a new commercial product line. Students also reported that participating in this research project improved their satisfaction with the introductory MIS course. These results encourage educators to conduct hands-on experience involving real-world research projects since they provide valuable additional learning opportunities in introductory MIS courses.

This article focuses on the synthesis of new series of pyrazole-substituted 9-anilinoacridine derivatives 5a–m and 6a–l. The compounds were confirmed by physical and analytical data. The synthesized compounds when screened for in vitro antioxidant activity showed promising activity for many compounds. The selected compounds were screened for cytotoxic activity showed promising inhibition of HEp-2 cell line for the compounds 6c, 6e, and 6f.

We have investigated the electrical and structural properties of Pt/Ti metallization scheme on n-type InP as a function of annealing temperature using current–voltage (I–V), capacitance–voltage (C–V), Auger electron spectroscopy (AES), and X-ray diffraction (XRD) measurements. Measurements showed that barrier height of as-deposited Pt/Ti Schottky contact is 0.62 eV (I–V) and 0.76 eV (C–V). Experimental results indicate that high-quality Schottky contact with barrier height and ideality factor of 0.66 eV (I–V), 0.80 eV (C–V), and 1.14 can be achieved after annealing at 400 °C for 1 min in N2 atmosphere. Further, it is observed that the barrier height slightly decreases to 0.55 eV (I–V) and 0.71 eV (C–V) after annealing at 500 °C. Norde method is also employed to calculate the barrier height of Pt/Ti Schottky contacts. The obtained values are in good agreement with those obtained by I–V measurements. These results indicate that the optimum annealing temperature for the Pt/Ti Schottky contact is 400 °C. According to AES and XRD analysis, the formation of indium phases at the Pt/Ti/n-InP interface could be the reason for the increase of Schottky barrier height (SBH) after annealing at 400 °C. Results also showed the formation of phosphide phases at the interface. This may be the reason for the decrease in the barrier height after annealing at 500 °C. The AFM results showed that the overall surface morphology of Pt/Ti Schottky contact is reasonably smooth.

This study explores the application of Innovation Diffusion Theory (IDT) to the adoption of disaster‐related preventative measures from a community perspective. A literature review showed that relative advantage, value and need compatibility, and network connectivity are important factors in the adoption decision. In order to prioritize among these factors, the researchers gathered information from response and recovery personnel. A content analysis of the transcripts revealed effective network interconnectivity as the most important factor. This research contributes by applying IDT and content analysis methods to disaster‐related preventative measures for a community. Based on the research results, we recommend that communities collect geospatial infrastructure data and populate it in information systems so that the community might recover from disasters quickly.

Nanostructured titanium dioxide thin films were prepared using reactive pulsed laser ablation technique. Effects of annealing on the structural, morphological, electrical and optical properties are discussed. The structural, electrical and optical properties of TiO2 films are found to be sensitive to annealing temperature and are described with GIXRD, SEM, AFM, UV-Visible spectroscopy and electrical studies. X-ray diffraction studies showed that the as-deposited films were amorphous and at first changed to anatase and then to rutile phase with increase of annealing temperature. Optical constants of these films were derived from the transmission spectra and the refractive index dispersion of the films, subjected to annealing at different temperatures, is discussed in terms of the single oscillator-Wemple and Didomenico model. (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

Colleges of Business (COBs) have experienced high growth rates in the past decade and many colleges are imposing minimum grade point average (GPA) requirements for students to enter or remain in the college. A primary reason for this requirement may be the belief that students with high GPAs are more inclined to demonstrate higher-order cognitive skills (HOCS) than students with low GPAs. It is not clear whether the link is valid. This study hypothesizes that students with high GPAs who are taught in the same way as students with lower GPAs will have higher perceptions of improved HOCS. We conducted an experiment in which students, with varying GPAs, at three large universities primarily used multimedia instructional materials. We obtained the students' perceptions of their improved HOCS from their responses to a survey. A regression analysis of the data reveals that the relationship between GPAs and students' perceived improvement in HOCS is significant (p < .001). We conclude the study by recommending that (a) it is critical to use research methodologies to evaluate perceived and actual learning improvements, (b) COB policies to implement GPA restrictions on admission are worthwhile, and (c) case studies need to be used much more frequently in undergraduate COB classes.

Detailed studies on the peroxidisulfate (PDS) initiated graft copolymerization of N-methyl aniline (NMA) with poly(ethylene terepthalate) (PET) were carried out in p-tolene sulfonic acid medium under nitrogen atmosphere. Experiments were designed to follow the rate of formation Rh of the poly(N-methyl aniline (PNMA), simultaneously with the rate of grafting of PNMA onto PET. Effects of concentration of NMA, PDS, PET, time, and temperature on Rh and graft parameters were followed. Kinetic equations were deduced to correlate the changes in the rate with experimental conditions. Graft copolymers were isolated and grafting of PNMA onto PET was confirmed through FTIR, thermogravimetric analysis, and conductivity measurements. Tensile measurements showed that grafting of PNMA did not alter the tensile properties of PET. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 95: 596–605, 2005

Studies have shown that it is difficult for people to deal with multicriteria decision-making situations. Information technology tools such as decision-support systems and expert systems have been developed in order to help them in such situations. Another tool that has been identified as helping managers understand complex engineering decision-making situations is multimedia instructional materials. This research investigates the perceptions of business versus engineering students on improvement of their higher-level cognitive skills when they participated in a multimedia-based case study that used an expert system to model a complex engineering and technical problem. Two groups of students, business and engineering, participated in an experiment, where they analyzed the case study and made their recommendations. Two questionnaires measured their perceptions on the improvements achieved on different constructs. A structural equations model was developed in order to test the research hypotheses with business students being the experimental group and the engineering students as a control group. The major findings are no significant relationship between student major and higher-order cognitive skills improvement, business students perceived more higher-order skills improvement compared to engineering students, both groups perceived an improvement in learning-driven factor, and business students valued learning-driven factors more compared to engineering students. These results show that multimedia instructional materials were perceived to be very useful in making multicriteria engineering and technical decisions.

A system reliability is often evaluated by individual tests of components that constitute the system. These component test plans have advantages over complete system based tests in terms of time and cost. In this paper, we consider the series system with n components, where the lifetime of the i-th component follows exponential distribution with parameter λi. Assuming test costs for the components are different, we develop an efficient algorithm to design a two-stage component test plan that satisfies the usual probability requirements on the system reliability and in addition minimizes the maximum expected cost. For the case of prior information in the form of upper bounds on λi's, we use the genetic algorithm to solve the associated optimization problems which are otherwise difficult to solve using mathematical programming techniques. The two-stage component test plans are cost effective compared to single-stage plans developed by Rajgopal and Mazumdar. We demonstrate through several numerical examples that our approach has the potential to reduce the overall testing costs significantly. © 2002 John Wiley & Sons, Inc. Naval Research Logistics, 49: 95–116, 2002; DOI 10.1002/nav.1051

Acceptance sampling plans are used to assess the quality of an ongoing production process, in addition to the lot acceptance. In this paper, we consider sampling inspection plans for monitoring the Markov-dependent production process. We construct sequential plans that satisfy the usual probability requirements at acceptable quality level and rejectable quality level and, in addition, possess the minimum average sample number under semicurtailed inspection. As these plans result in large sample sizes, especially when the serial correlation is high, we suggest new plans called “systematic sampling plans.” The minimum average sample number systematic plans that satisfy the probability requirements are constructed. Our algorithm uses some simple recurrence relations to compute the required acceptance probabilities. The optimal systematic plans require much smaller sample sizes and acceptance numbers, compared to the sequential plans. However, they need larger production runs to make a decision. Tables for choosing appropriate sequential and systematic plans are provided. The problem of selecting the best systematic sampling plan is also addressed. The operating characteristic curves of some of the sequential and the systematic plans are compared, and are observed to be almost identical. © 2001 John Wiley & Sons, Inc. Naval Research Logistics 48: 451–467, 2001

Engineering students are expected to be not only technically proficient, but, also to exhibit a sound awareness of real-world issues such as marketing, finance, communications, and interpersonal relations. We found that this is best learned by participating in a case study method of instruction. This paper describes the results of a research undertaken by the authors to develop a teaching methodology to bring real-world issues into engineering classrooms. It describes the steps taken in developing an engineering-management case study, administering this case study in a classroom, and results of evaluating the effectiveness of this method of instruction. In particular, it focuses on the students' and professional engineers' perceptions on the utility of the case study method of instruction in engineering classes. The results of the research lead to recommendations to funding agencies and educators on the need to develop interdisciplinary technical case studies so that the innovations happening in the engineering world can be communicated to the students in the classrooms.

A series of 9-anilinoacridines substituted with oxazine derivatives were synthesized to evaluate their antioxidant and anticancer activity against Daltons Lymphoma Ascites (DLA) cell growth by in vitro method. It was revealed that these conjugates exhibited significant antioxidant and anticancer activity (inhibition of DLA cell proliferation). Among these agents, compounds 5a, 5h, 5i, 5j were the most cytotoxic with CTC(50) value of 140-250 μg/mL. The docking studies of the synthesized compounds were performed towards the key Topoisomerase II (1QZR) by using Schrodinger Maestro 9.2 version. The oxazine substituted 9-anilinoacridine derivatives 5a, 5h, 5i, 5j have significant anticancer activity as topoisomerase II inhibitors.

A series of novel pyrazole-substituted 9-anilinoacridines are designed, synthesized and evaluated for their in vitro antioxidant and cytotoxic activity.

Pure gas and hydrocarbon vapor transport properties of blends of two glassy, polyacetylene-based polymers, poly(1-trimethylsilyl-1-propyne) [PTMSP] and poly(1-phenyl-1-propyne) [PPP], have been determined. Solid-state CP/MAS NMR proton rotating frame relaxation times were determined in the pure polymers and the blends. NMR studies show that PTMSP and PPP form strongly phase-separated blends. The permeabilities of the pure polymers and each blend were determined with hydrogen, nitrogen, oxygen, carbon dioxide, and n-butane. PTMSP exhibits unusual gas and vapor transport properties which result from its extremely high free volume. PTMSP is more permeable to large organic vapors, such as n-butane, than to small, permanent gases, such as hydrogen. PPP exhibits gas permeation characteristics of conventional low free volume glassy polymers; PPP is more permeable to hydrogen than to n-butane. In PTMSP/PPP blends, both n-butane permeability and n-butane/hydrogen selectivity increase as the PTMSP content of the blends increases. © 1996 John Wiley & Sons, Inc.

An aromatic copolyester composed of 25 mol % phenyl hydroquinone, 10 mol % isophthalic acid, 40 mol % chloroterephthalic acid, and 25 mol % t-butyl hydroquinone (PICT) has been synthesized. This amorphous, glassy polymer is soluble in common organic solvents such as methylene chloride. Thin, solution-cast films may be prepared which are in a metastable, vitrified, optically isotropic state. On first heating of an isotropic film at 20°C/min in a calorimeter, one glass transition is observed at low temperature (approximately 49°C) and is ascribed to the glass/rubber transition of the metastable, isotropic polymer. This thermal event is followed by a small exotherm due to the development of order during the scan, which results in a second Tg at approximately 125°C. This Tg is associated with the glass/rubber transition of the ordered polymer. Nematic order can be developed by thermal annealing. The lower Tg increases toward the upper Tg as annealing time is increased. For an initially isotropic film annealed at 90°C, the increase of the lower Tg with annealing time and the increase in birefringence observed by optical microscopy are governed by similar kinetics. Isotropization occurs in the temperature range of 250–300°C. The nematic polymer is slightly more dense than its isotropic analog. No detectable differences between isotropic and nematic samples were observed in rotating frame proton spin lattice relaxation times. © 1996 John Wiley & Sons, Inc.

Some compounds show significant antibacterial, e.g. (Va), (Ve), (Vg), (Vi), good antifungal, e.g. (Vg), (Vh), good anticancer, e.g. (Vf), (Vh) or significant antitubercular activities (Vb).

High-resolution solid-state 13C-NMR has been used to study the phase separation and molecular motion in two series of polyurethane foams. These two series differ by one possessing the additive of lithium chloride, LiCl. NMR relaxation times can map the motion throughout the polymer molecule and detect changes in that motion arising from either microseparation or phase mixing between the different segments. There are only slight changes in the soft segment T1p(13C) values as well as an increase in the hard segment T1p(1H) values with increase in the hard segment content for the foams studied. The T1p(1H) and T1p(13C) values do indicate that the phase separation of the hard and soft segments is similar for all foams. A decrease in the T1p(1H) and T1p(13C) values with increasing LiCl content indicates that the motion of the soft segments is restricted more by the hard segments. This is explained by more phase mixing in the foams containing the LiCl additive. © 1994 John Wiley & Sons, Inc.

In a previous article,1 we reported on the interaction of cellulose with NH3/NH4SCN by using solid state CP / MAS 13C-NMR, wide-angle X-ray and other techniques. It appears that during an imposed temperature cycling sequence, specific cellulosic inter- and intramolecular hydrogen bonds are broken as polymorphic conversion and, ultimately, dissolution occurs. Cellulose is converted from the polymorph I to II to III and, finally, to amorphous. We speculate that these changes proceed via transformation of the polymorph conformations of CH2OH from trans-gauche, “tg,” to gauche-trans, “gt,” to gauche-gauche, “gg.” Remarkably, the temperature cycling effectively and rapidly effects these changes, seemingly, by invoking at two different temperatures (22°C and −78°C), a subtle but powerful temperature-related interplay of enthalpic and entropic forces. At the higher of the cycling temperature limits, entropy and van der Waals forces dominate, causing NH3 to partition in favor of the liquid phase. At the lower of the temperature cycling limits, enthalpy dominates and the situation is reversed favoring NH3 partition toward the cellulose, resulting in breakage of inter- and intracellulosic H-bonds by the interpenetrating ammonia to form new H-bonds between cellulose and ammonia, leading ultimately to conformational changes and, ultimately, even dissolution. © 1994 John Wiley & Sons, Inc.

In this article, a systematic method to derive dynamic equations of motion for flexible robot manipulators is developed by using the Lagrangian assumed modes method. The proposed method can be applied to dynamic simulation and control system design for flexible robot manipulators. In the proposed method, the link deflection is described by a truncated modal expansion. The operations of only 3x3 matrices and/or 3 × 1 vectors exist in the method. All the dynamics computations are performed in the link coordinate systems, where the kinematics informations are computed with the forward recursion from the base to the hand tip and the dynamics informations are computed with the return recursion. As generally compared with other existing methods, the method proposed in this article is, computationally, more simple, systematic, and efficient. A computational simulation for a single-link flexible robot manipulator is presented to verify the proposed method. © 1992 John Wiley & Sons, Inc.

The effect of a manipulator inertial parameter errors on the manipulator system performance are studied. First, the relationships between the tracking error of the manipulator joint variables and the manipulator inertial parameter errors are derived. Then, using these relationships, the maximum steady state position, velocity, and acceleration errors of the joint variables are determined. The derived relationships allow us to acquire a desired steady state performance for joint variations either by increasing the control gains in the feedback control loops and/or by reducing the manipulator inertial parameter errors. These two problems are, also, addressed in this paper. The computational results of the maximum steady state position, velocity, and acceleration errors of the joints for a PUMA 560 arm are included.

It has been shown that incorporation of masked isocyanates in the MY720/DDS epoxy significantly reduces the equilibrium moisture absorption by blocking of residual functional groups ( oxirane group) by the isocyanates released in the deblocking reaction of the masked isocyanates. We have now used high resolution 13C-CP/MAS NMR to follow the reactions in the solid state and to identify intermediates and by-products. The deblocking reaction of the masked isocyanates also releases the corresponding alcohol, part of which may evaporate during the curing reaction. The resolution in the solid-state spectra is good enough to identify all the reactants and the intermediates involved in the curing reaction. Difference spectra are used to emphasize changes between systems that differ in treatment or composition.

Films of a base polymer, primarily a terpolymer of n-butyl acrylate, vinyl acetate, and vinyl chloride, that is used in latex paint, have been exposed to various combinations of UV/air, UV/SO2, and UV/SO2/H2O. Reported here are results of elemental analyses, XPS and 13C magic angle spinning NMR of the exposed samples. When samples are exposed to UV/SO2 or UV/SO2/H2O, there is clear evidence of the incorporation of sulfur into the polymer, and there is significant loss of the acetate group in the copolymer. There is also evidence of the formation of unsaturated carbon–carbon bonds which is due to loss of the acetate groups and some dehydrohalogenation. During the time scale of exposures, changes in the composition and structure of samples exposed to UV/air were not detected by the techniques considered here although some chain scission and crosslinking undoubtedly occur. The results suggest a synergistic interaction between SO2 and UV leading to rapid degradation of the polymer, and that the presence of atmospheric SO2 pollutants can have an adverse effect on the lifetime of latex coating materials.

Experimental results from buckling tests on thin shell structures made of filament-wound glass fiber reinforced plastic are compared to values calculated with three different procedures. These procedures are: (1) a linear stability analysis for anisotropic, heterogeneous, thin, cylindrical shells, (2) a proposed design code, and (3) a national standard. Imperfection surveys in the circumferential direction were conducted and were found to be much larger than imperfections typical for metallic thin shells. All three procedures yield design pressures lower than observed buckling pressures. The analytical method and the standard are less conservative than the proposed design code and may possibly permit the fabrication of safe and more economical structures.

Application a la flexion d'une coque spherique stratifiee renforcee de fibres, sous une charge uniformement repartie

Several cellulose derivatives were synthesized and characterized by IR and 1H-NMR spectroscopy. The positions of substitution in these derivatives were confirmed using solid state 13C-NMR spectroscopy techniques.

The self-consistent multiple scattering Xα (MSXα) method is used to arrive at the electronic structure of a helium-trapped vacancy in aluminum using a cluster model. The calculated orbital energies, electron density, and charge distributions are compared with the available theoretical results. It is shown that helium trapping causes the reshuffling and upward movement of the cluster levels (with vacancy).

A new procedure is suggested for numerical treatment of elastic contact problems for non-classical domains. The numerical procedure is based on formulae derived for an accurate computer evaluation of singular integrals. These formulae define the value of the singular integral in the neighbourhood of the singularities, while the regular part of the integral can be evaluated by any standard subroutine. The method allows practically exact solution of elastic contact problems for punches of various plan forms like, for example, rectangle, rhombus, triangle, oval, etc. The nature of the stress singularity at the boundary of the domain of contact is clarified. Numerical results presented for a rectangle indicate that the assumption of a square root singularity is wrong, and that the power of the singularity is not constant along a rectangle edge.

The following electrostatic potential problem is considered: arbitrary potential distribution is given on a spherical cap, the electric charge distribution is to be determined. The closed form solution is obtained by a special integral representation of the kernel of governing integral equation. Two examples are considered: uniform potential distribution over a spherical cap, and the case of earthed conducting spherical cap in a uniform electrical field. The expressions for the electric charge distribution and the total charge are given. The general results of this paper may be also applied to the related problems of a fluid flow and thermoconductivity. Die folgende Aufgabe zum elektrostatischen Potential wird betrachtet: Gegeben ist eine beliebige Potentialverteilung auf einer Kugelkalotte, dann bestimme man die Verteilung der elektrischen Ladung. Man erhalt eine Losung in geschlossener Form durch eine spezielle Integraldarstellung des Kerns der kontrollierenden Integralgleichung. Es werden zwei Beispiele betrachtet: homogene Potentialverteilung uber einer Kugelkalotte und der Fall einer geerdeten leitenden Kugelkalotte in einem homogenen elektrischen Feld. Die Ausdrucke fur die Verteilung der elektrischen Ladung und die Gesamtladung werden angegeben. Die allgemeinen Ergebnisse dieser Arbeit konnen auch auf die verwandten Probleme einer Flussigkeitsstromung und der Warmeleitfahigkeit angewendet werden.

1H NMR spin-lattice relaxation times (T1) of the NCH3 proton resonances of phosphocreatine (PCr) and creatine (Cr) in water solutions were obtained using the 1,3,3,1 pulse sequence. These T1 values were equivalent to those obtained in D2O and water using either the conventional inversion-recovery experiment or the 1,3,3,1 pulse sequence. Thus, the 1,3,3,1 sequence of proton NMR can provide an independent means along with phosphorous NMR for assess PCr and for the study of the creatine kinase reaction (PCr + ADP ⇌ ATP + Cr) in aqueous solutions and perhaps in biological preparations. © 1986 Academic Press, Inc.

The effect of water and isooctane absorption on the flexural fatigue strength of a sheet molding compound (SMC-R30) is investigated. Absorption of water reduces the fatigue life of specimens of SMC-R30 as compared to the fatigue life of specimens tested in air. Absorption of isooctane reduces the fatigue life much more than absorption of water.