Abstract: In this paper,the exponential passivity criteria for BAM neural networks with time-varying delays is studied.By constructing new Lyapunov-Krasovskii functional and dividing the delay interval into multiple segments,a novel sufficient condition is established to guarantee the exponential stability of the considered system.Finally,a numerical example is provided to illustrate the usefulness of the proposed main results
Abstract: Alongside with antioxidant, pro-oxidant activity is also observed in phytochemical compounds. In the study, Ficus odorata, an endemic medicinal plant in the Philippines, was screened for the potential medical application of its pro-oxidant activity.
Phytochemical screening revealed the presence of terpenes, glycosides and phenolic acids. The crude extract was found to contain low gallic acid and quercetin equivalence. The TLC chromatogram of the crude extract showed that none of the 11 spots obtained has antioxidant activity nor correspond to gallic acid and quercetin standards. Experiments showed that the crude extract has stimulatory activity towards DPPH radicals, hydrogen peroxide, hydroxyl radicals, superoxide anions and nitric oxide. Moreover, the extract exhibited a low ferric reducing power.
The prooxidant activity was evident in the crude ethanolic leaf extract of F. odorata, which may provide a better understanding of the plant’s pharmacological importance in the prevention of diseases.
Abstract: An empirical correlation for predicting the heat transfer coefficient for a cylinder under free convection, inclined at any arbitrary angle with the horizontal has been developed in terms of Nusselt number, Prandtl number and Grashof number. Available experimental data was used to determine the parameters for the proposed correlation. The proposed correlation predicts the available data well within ±10%, for Prandtl number in the range 0.68-0.72 and Grashof number in the range 1.4×104–1.2×1010.
Abstract: Bangladesh is a patriarchal and male dominated country. Traditional, cultural, social, and religious values and practices have reinforced the lower status of women accorded to them in society and have limited their opportunities for education, technical and vocational training, and involvement with earning activities outside their households. After independence numbers of women are doing job outside their households. This study attempts to find out the reasons of engaging in earning activities outside households and difficulties faced by upper and lower class working women in Bangladesh. To explore the objectives and research questions of the study descriptive techniques had been used. Survey was conducted among the women who were working in Rajshahi city of Bangladesh and face-to-face interviews were conducted to collect data. Findings of the study illustrates that most of the upper class working women engaged into job because they wanted to utilized their education and to bring solvency in the family, and they spend their income for meeting the needs of all the members of the family. On the other hand, most of the lower class working women involved into earning activities outside their households because they want to bring solvency in their families and spend their income on household expenditure. Both classes became tensed for their children because they had to stay at their working place for long time. Therefore, day care center should be established besides their working place for their children.
Abstract: River flow prediction is an essential tool to ensure proper management of water resources and the optimal distribution of water to consumers. This study presents an analysis and prediction by using nonlinear prediction method with monthly river flow data for Tanjung Tualang from 1976 to 2006. Nonlinear prediction method involves the reconstruction of phase space and local linear approximation approach. The reconstruction of phase space involves the reconstruction of one-dimension (the observed 287 months of data) in a multidimensional phase space to reveal the dynamics of the system. The revenue of phase space reconstruction is used to predict the next 72 months. A comparison of prediction performance based on correlation coefficient (CC) and root mean square error (RMSE) was employed to compare prediction performance for the nonlinear prediction method, ARIMA and SVM. Prediction performance comparisons show that the prediction results using the nonlinear prediction method are better than ARIMA and SVM. Therefore, the results of this study could be used to develop an efficient water management system to optimize the allocation of water resources.
Abstract: Ozone is well known as a powerful, fast reacting oxidant. Ozone based processes produce no by-product residual as non-reacted ozone decomposes to molecular oxygen. Therefore an application of ozone is widely accepted as one of the main approaches for a Sustainable and Clean Technologies development.
There are number of technologies which require ozone to be delivered to specific points of a production network or reactors construction. Due to space constraints, high reactivity and short life time of ozone the use of ozone generators even of a bench top scale is practically limited. This requires development of mini/micro scale ozone generator which can be directly incorporated into production units.
Our report presents a feasibility study of a new micro scale rector for ozone generation (MROG). Data on MROG calibration and indigo decomposition at different operation conditions are presented.
At selected operation conditions with residence time of 0.25 s the process of ozone generation is not limited by reaction rate and the amount of ozone produced is a function of power applied. It was shown that the MROG is capable to produce ozone at voltage level starting from 3.5kV with ozone concentration of 5.28*10-6 (mol/L) at 5kV. This is in line with data presented on numerical investigation for a MROG. It was shown that in compare to a conventional ozone generator, MROG has lower power consumption at low voltages and atmospheric pressure.
The MROG construction makes it applicable for both submerged and dry systems. With a robust compact design MROG can be used as an integrated module for production lines of high complexity.
Abstract: This paper proposes a new obstacle and collision
avoidance control laws for a three-dimensional swarm of boids.
The swarm exhibit collective emergent behaviors whilst avoiding the
obstacles in the workspace. While flocking, animals group up in order
to do various tasks and even a greater chance of evading predators. A
generalized algorithms for attraction to the centroid, inter-individual
swarm avoidance and obstacle avoidance is designed in this paper.
We present a set of new continuous time-invariant velocity control
laws is presented which is formulated via the Lyapunov-based control
scheme. The control laws proposed in this paper also ensures practical
stability of the system. The effectiveness of the proposed control laws
is demonstrated via computer simulations
Abstract: This paper aims to examine whether a bubble is present in the housing market of China. Thus, we use the housing price-to-income ratios and housing price-to-rent ratios of 35 cities from 1998 to 2010. The methods of the panel KSS unit root test with a Fourier function and the SPSM process are likewise used. The panel KSS unit root test with a Fourier function considers the problem of non-linearity and structural changes, and the SPSM process can avoid the stationary time series from dominating the result-generated bias. Through a rigorous empirical study, we determine that the housing price-to-income ratios are stationary in 34 of the 35 cities in China. Only Xining is non-stationary. The housing price-to-rent ratios are stationary in 32 of the 35 cities in China. Chengdu, Fuzhou, and Zhengzhou are non-stationary. Overall, the housing bubbles are not a serious problem in China at the time.
Abstract: In this paper, we propose a solution to the motion
planning and control problem for a swarm of three-dimensional
boids. The swarm exhibit collective emergent behaviors within the
vicinity of the workspace. The capability of biological systems
to autonomously maneuver, track and pursue evasive targets in a
cluttered environment is vastly superior to any engineered system. It
is considered an emergent behavior arising from simple rules that are
followed by individuals and may not involve any central coordination.
A generalized, yet scalable algorithm for attraction to the centroid
and inter-individual swarm avoidance is proposed. We present a set
of new continuous time-invariant velocity control laws, formulated via
the Lyapunov-based control scheme for target attraction and collision
avoidance. The controllers provide a collision-free trajectory. The
control laws proposed in this paper also ensures practical stability
of the system. The effectiveness of the control laws is demonstrated
via computer simulations.
Abstract: According to fuzzy arithmetic, dual fuzzy polynomials cannot be replaced by fuzzy polynomials. Hence, the concept of ranking method is used to find real roots of dual fuzzy polynomial equations. Therefore, in this study we want to propose an interval type-2 dual fuzzy polynomial equation (IT2 DFPE). Then, the concept of ranking method also is used to find real roots of IT2 DFPE (if exists). We transform IT2 DFPE to system of crisp IT2 DFPE. This transformation performed with ranking method of fuzzy numbers based on three parameters namely value, ambiguity and fuzziness. At the end, we illustrate our approach by two numerical examples.
Abstract: Al/Cu clad sheet has been fabricated by using differential speed rolling (DSR) process, which caused severe shear deformation between Al and Cu plate to easily bond to each other. Rolling was carried out at 100 and 150oC with speed ratios from 1.4 to 2.2, in which the total thickness reduction was in the range between 14 and 46%. Interfacial microstructure and mechanical properties of Al/Cu clad were investigated by scanning electron microscope equipped with energy dispersive X-ray detector, and tension tests. The DSR process was very effective to provide a good interface for atoms diffusion during subsequent annealing. The strength of bonding was higher with the increasing speed ratio. Post heat treatment enhanced the mechanical properties of clad sheet by forming intermetallic compounds in the interface area.
Abstract: This study applies a simple and powerful nonlinear unit root test to test the validity of long-run purchasing power parity (PPP)
in a sample of 10 East-Asian countries (i.e., China, Hong Kong, Indonesia, Japan, Korea, Malaysia, Philippines, Singapore, Taiwan and Thailand) over the period of March 1985 to September 2008. The empirical results indicate that PPP holds true for half of these 10 East-Asian countries under study, and the adjustment toward PPP is found to be nonlinear and in an asymmetric way.
Abstract: The development of alternative energy is interesting in the present especially, hydrogen production because it is an important energy resource in the future. This paper studied the hydrogen production from catalytic dehydrogenation of ethanol through via low temperature (
Abstract: Wind farms usually produce power irregularly, due to unpredictable change of wind speed. Accordingly, we should determine the penetration limit of wind power to consider stability of power system and build a facility to control the wind power. The operational limit of wind power is determined as the minimum between the technical limit and the dynamic limit of wind power. The technical limit is calculated by the number of generators and the dynamic limit is calculated by the constraint of frequency variation when a wind farm is disconnected suddenly. According to the determined operational limit of wind power, pitch angles of wind generators are controlled. PSS/E simulation results show that the pitch angles were correctly controlled when wind speeds are changed in addition to loads.
Abstract: The 21st century has been characterized by rapid urbanization with its associated environmental sanitation challenges especially in developing countries. However, studies have focused largely on institutional capacity and the resources needed to manage environmental sanitation challenges, with few insights on the attitudes of city residents. This paper analyzes the environmental sanitation situation in a rapidly urbanizing Tamale metropolis, examines how city residents’ attitudes have contributed to poor environmental sanitation and further reviews approaches that have been employed to manage environmental sanitation. Using secondary and empirical data sources, the paper reveals that only 7.5 tons of 150 tons of total daily solid wastes generated is effectively managed. The findings suggest that the poor sanitation in the city is influenced by two factors; poor attitudes of city residents and weak institutions. While poor attitudes towards environmental sanitation has resulted in indiscriminate disposal of waste, weak institutions have resulted in lack of capacity and pragmatic interventions to manage the environmental sanitation challenges in the city. The paper recommends public education on environmental sanitation, public private partnership, increased stakeholder engagement and preparation and implementation of environmental sanitation plan as mechanisms to ensure effective environmental sanitation management in the Tamale metropolis.
Abstract: E-mail has become a key mechanism of electronic communication. This is true for professional organizations that like to communicate with their subjects online and are slowly shifting to paper-less office. The current paper focuses specifically on academic institutions offering Engineering course in Gujarat state and attempts for textual analysis of the usernames of the institutional e-mail addresses. We found that the institutions tend to design the username segment of their e-mail addresses by choosing words or combination of words from specific categories. The paper also highlights the use of special characters, digits and random words in designing the usernames. On the sidelines, the paper lists the style of employing department names and designations for the design process. To the best of our knowledge, this is the first formal attempt to analyze the selection of words employed for designing username segment of e-mail addresses of engineering institutions.
Abstract: A failure of the non-structural component can cause significant damages in critical facilities such as nuclear power plants and hospitals. Historically, it was reported that the damage from the leakage of sprinkler systems, resulted in the shutdown of hospitals for several weeks by the 1971 San Fernando and 1994 North Ridge earthquakes. In most cases, water leakages were observed at the cross joints, sprinkler heads, and T-joint connections in piping systems during and after the seismic events. Hence, the primary objective of this study was to understand the seismic performance of T-joint connections and to develop an analytical Finite Element (FE) model for the T-joint systems of 2-inch fire protection piping system in hospitals subjected to seismic ground motions. In order to evaluate the FE models of the piping systems using OpenSees, two types of materials were used: 1) Steel02 materials and 2) Pinching4 materials. Results of the current study revealed that the nonlinear moment-rotation FE models for the threaded T-joint reconciled well with the experimental results in both FE material models. However, the system-level fragility determined from multiple nonlinear time history analyses at the threaded T-joint was slightly different. The system-level fragility at the T-joint, determined by Pinching4 material was more conservative than that of using Steel02 material in the piping system.
Abstract: Pyrazinamide (PZA) is among the first-line pro-drugs in the tuberculosis (TB) combination chemotherapy used to treat Mycobacterium tuberculosis. Numerous reports have suggested that hepatotoxicity due to pyrazinamide in patients is due to inappropriate dosing. It is, therefore necessary to develop sensitive and reliable techniques for determining the PZA metabolic profile of diagnosed patients promptly and at point-of-care. This study reports the determination of PZA based on nanobiosensor systems developed from disuccinimidyl octanedioate modified Cytochrome P450-2E1 (CYP2E1) electrodeposited on gold substrates derivatised with (poly(8-anilino-1-napthalene sulphonic acid) PANSA/PVP-AgNPs nanocomposites. The rapid and sensitive amperometric PZA detection gave a dynamic linear range of 2µM to 16µM revealing a
limit of detection of 0.044µM and a sensitivity of 1.38µA/µM. The Michaelis-Menten parameters; KM, KM app and IMAX were calculated to be 6.0µM, 1.41µM and 1.51x10-6 A, respectively, indicating a nanobiosensor suitable for use in serum.
Abstract: In this study, thermo elastic stress analysis is performed on a cylinder made of laminated isotropic materials under thermomechanical loads. Laminated cylinders have many applications such as aerospace, automotive and nuclear plant in the
industry. These cylinders generally performed under thermomechanical loads. Stress and displacement distribution of the laminated cylinders are determined using by analytical method both thermal and mechanical loads. Based on the results, materials combination plays an important role on the stresses distribution along the radius. Variation of the stresses and displacements along the radius are presented as graphs. Calculations program are prepared using MATLAB® by authors.
Abstract: In this project three type of tools, straight cylindrical, taper cylindrical and triangular tool all made of High speed steel (Wc-Co) used for the friction stir welding (FSW) aluminum alloy H20–H20 and the mechanical properties of the welded joint tested by tensile test and vicker hardness test. Besides, mentioned mechanical properties compared with each other to make conclusion. The result helped design of welding parameter optimization for different types of friction stir process like rotational speed, depth of welding, travel speed, type of material, type of joint, work piece dimension, joint dimension, tool material and tool geometry. Previous investigations in different types of materials work pieces; joint type, machining parameter and preheating temperature take placed. In this investigation 3 mentioned tool types that are popular in FSW tested and the results completed other aspects of the process. Hope this paper can open a new horizon in experimental investigation of mechanical properties for friction stir welded joint with other different type of tools like oval shape probe, paddle shape probe, three flat sided probe, and three sided re-entrant probe and other materials and alloys like titanium or steel in near future.