Search

Advanced oxidation processes utilizing both UV/H2O2 and photo-Fenton UV/H2O2/Fe+3 systems were investigated using pilot-scale experiments for the degradation and mineralization of 4-chlorophenol (4-CP). The experiments were conducted by using a photoreactor, which consists of three UV lamps fixed in staggered form. Three baffles were fixed vertically at the reactor side walls. These baffles reduce the presence of low radiation zones near the reactor walls. The study shows that the photo-Fenton process was the most effective treatment process under acidic conditions pH = 3, and produced a higher rate of degradation of 4-CP at a very short irradiation time. The reaction was found to follow the first order through both systems. A colored solution of benzoquinone can be observed through the first 5 min of irradiation time for the UV/H2O2 system when a low concentration (0.01 mol/L) of H2O2 was used. The colored solution of benzoquinone can also be observed through the first 5 min for the UV/H2O2/Fe+3 ...

Wireless mesh networks (WMNs) can be considered as a key technology for next-generation wireless networking. However, field trials and experiments prove that the performance of WMNs still below expectations. Therefore, several challenging research issues need to be determined. The routing protocol is one of the important factors to be improved to be robust, scalable, secured and efficient. This paper aims to design and implement a routing protocol that improves the scalability of the WMNs. The Directional Hierarchical AODV (DH-AODV) routing protocol is proposed taking advantage of the existing fields of the control packets in the AODV in order to reduce the load on the network's bandwidth and to quickly detect route breakage. The proposed protocol is designed, implemented and evaluated using Qualnet Simulator. The Ad-hoc on Demand Distance Vector (AODV) is selected as a benchmark. The simulation results indicate that this enhanced routing protocol can 47% reduce the end-to-end delay of data packets, improve the throughput by 11.2%, and decrease the packet loss rate 20% less than the standard AODV.

A design of an ultra-wideband (UWB) bandpass filter (BPF) is presented depending on the composite right/left handed-transmission line (CRLH-TL) basis. The interdigital (ID) coupled lines and complementary split ring resonators (CSRRs) are the tools used to realize an UWB microwave filter with an appreciable size reduction and better performance. The bandwidth resulted from this filter is 5.6 GHz operating at 3.2 GHz center frequency. The interdigital elements are connected to the input and output ports through square closed rings in the upper side of the microstrip line, whereas the CSRRs are etched in the ground of the microstrip line. All components contribute together to get metamaterial (MTM) media containing negative permittivity and negative permeability. The simulated results show that the filter has a flat insertion loss of less than 1 dB with an acceptable return loss performance in the frequency range (0.4–6) GHz. The achieved quality factor is equal to 0.57 and the fractional bandwidth is over 100 %.

This work proposes an end-coupled half wavelength resonator dual bandpass filter (BPF). The filter is designed to have a 10.9% fractional bandwidth (FBW) at center frequency of 5.5GHz. Dual-band BPF with more drastic size reduction can be obtained by using metallic vias act as shunt-connected inductors to get negative permittivity (-e). The process of etching rectangular split ring resonators (SRRs) instead of open-end microstrip transmission lines (TLs) for planar BPF to provide negative permeability (-μ) is presented. The primary goals of these ideas are to get reduction in size, dual- and tri- bands frequency responses. These metamaterial transmission lines are suitable for microwave filter applications where miniaturization, dual- and tri-narrow passbands are achieved. Numerical results for the end-coupled microwave BPFs design are obtained and filters are simulated using software package HFSS. All presented designs are implemented on the Roger RO3210 substrate material that has; dielectric constant e r=10.8, and substrate height h=1.27 mm.

This paper presents a compact stopband filters and bandpass filters using microstrip transmission lines coupled with two parallel sides of square split ring resonators (SRRs) and metallic vias holes. SRRs etched on the upper plane of microstrip line to provide negative value of effective permeability (μ < 0) to the medium in a narrow band above their resonance frequency. Narrow bandpass filter with more drastic size reduction can be obtained by using metallic via holes to get negative effective permittivity (e < 0) with negative effective permeability (μ < 0) which is generated by using SRRs. Backward wave propagation is achieved as a LHM when SRRs and via holes are applied together. These metamaterial components (SRRs and metallic via holes) are useful for compact narrow stopband and narrow bandpass filters applications at 3GHz resonance frequency. The process of adding many numbers of SRRs and taking many widths of strip conductor (W) with gap variations between resonators and strip line are studied and simulated. The length (l) of the structures can be as small as 0.3 times the signal wavelength at resonance frequency.

In this work, the tuning forks (TFs) shape and complementary split ring resonators (CSRRs) are the tools used to present new UWB microwave filters. Two tuning forks are printed on the upper side of the microstrip line covering the host transmission lines. The filter bandwidth containing tuning forks is ultra-wide and equal to 11.8GHz operating at 6.1GHz center frequency. A novel method to upgrade the matching between the host transmission lines and the CSRRs is proposed as well. The bandwidths of the developed filters containing tuning forks with the presence of different CSRRs at different designs are 10, 6.8, 5.5 and 4.7GHz at 5.4, 3.6, 3 and 2.55GHz center frequency, respectively. The negative permittivity metamaterial is made of CSRRs which are etched in the lower side of the microstrip line. These metamaterial filters combine negative characteristics of permeability and permittivity which are created by using TF and CSRRs components respectively to create an UWB response with better performance and size reduction. The simulation results showed that the filters have composite right/left handed (CRLH) behavior with insertion losses less than 1dB and suitable average rejections.

Present industrial environment is quite different than past. Globalization and market driven forces has made the working environment quite competitive. It is quite obvious that these factors when combined with environmental factors, lead to poor operators/workers performance. Therefore, ergonomists has new challenges in terms of predicting workers efficiency as well as workers health protection and well being.

Corporate governance is a subject of academic and professional debate. It has and it will continue to be a topic under scrutiny for subsequent deliberations since there are many different research dimensions and contexts associated with it. However, it has been observed that the linkage between corporate governance and strategy of a corporation remains as an untapped area with considerable avenues of research. This paper tends to explore this linkage, using Enron scandal as backdrop. In the aftermath of the debacle of US energy giant Enron in 2001, the significance of corporate governance has come under heavy scrutiny of different researchers. Whereas different explanations have been attributed to its downfall, it has been widely accepted that this was a case of failed corporate governance. This paper tends to explore Enron downfall from the perspective of failed corporate governance. By defining and exploring corporate governance and its underlying issues, the authors have used Agency theory as a theoretical framework in unison with internationally renowned auditing company - Ernst & Young Model - to understand the role of different actors and forces responsible for Enron collapse. By using qualitative research method, the authors have used secondary literature as well as combination of questionnaires and telephonic interviews to obtain viewpoint of renowned international academic / professional researchers. They have been identified through convenience sampling methodology. A few internationally renowned auditing companies have also been used as part of this survey to explore diversity of perspectives in this context. Efforts have been made; to explore the main causes rather then to write just another case on Enron. After drawing lessons from Enron, the paper concludes with the understanding that there is direct link between corporate governance and strategy of corporations. However there is diversity of perspectives in this context and hence it requires further exploration and debate.

A 21 years old male presented with enlarged cervical lymph nodes. Diagnosis of anaplastic large cell lymphoma was made on lymph node biopsy and confirmed by immunohistochemistry using a panel of monoclonal antibodies including ALK-1. Bone marrow aspiration revealed the presence of large lymphoma cells and trephine biopsy showed interstitial involvement. In addition, there was presence of binucleate cells, lymphocytes, plasma cells and eosinophils. All these features resulted in a strong resemblance of the morphology with Hodgkin's lymphoma.

This paper aims to tell out a “what next” question of the future scenarios that the European Union (EU), as a security community, is most likely to face in its development as a world power up to the year 2020. The EU is a rapidly evolving concept consolidating with comprehensive internal and external dimension and implication. Key concepts such as power, security, global governance and international order have been used as the underlying themes that will determine the course of the future. In this context Neo-realism, Constructivism and Security Community’s model have been used as the theoretical framework to examine how EU’s role in the international system can be analyzed in the conceptual framework of security. This is followed by a discussion on the concurrent ESDP instruments initiated by the new Constitution as a key momentum of security community buildup internally. To broaden understanding and to get a variety of perspectives, research reports and policy papers of some transatlantic think tanks were analyzed. While multi- perspectives of some prominent think tanks were reviewed, analyzed and discussed, the opinions of policy makers at the United Nations Head Quarters, New York, were also explored to reflect on how EU’s role in international affairs is being perceived in the corridors of power, both concurrently and futuristically. These views were consequently augmented by attending General Assembly and Security Council sessions during September 2004 to January 2005 to observe what sorts of power and influence EU exerts in the contemporary international system and what potential it has for the future. Based on these findings, the paper identified three scenarios that EU is most likely to face in its efforts to be an international power. The paper concluded with the understanding that EU has vision and potential to be a power in the international system futuristically, which can be further enhanced if EU enhances its military capabilities and improves its power perception in the eyes of various stakeholders. However since the international system is volatile, its future role cannot be predicted with accuracy, only alternative options can be identified. EU’s roles are dependent upon the degree of success of the integration process internally and the structural interaction with other major actors in the international system. Whereas EU may enhance its role up to the year 2020, it may not enter into a power conflict with other major powers. However it will play its role comparable with the magnitude of its size, power and influence to manage the international system, futuristically in an improvised way.

This open-label study investigated the strategy of switching patients who had gained excessive weight on olanzapine to quetiapine, with assessments of safety and continued efficacy as well as weight change. Patients who were psychiatrically stable on olanzapine but had gained >20% in weight and had body mass index >25 mg/kg2 were switched to quetiapine over a 4-week period and followed for 6 weeks, the total study duration being 10 weeks. Assessments included weight change, antipsychotic efficacy using the Positive and Negative Symptom Syndrome Scale (PANSS), extrapyramidal adverse events using the Simpson–Angus Scale (SAS), and laboratory studies for metabolic measures. Of 16 enrolled patients, 12 completed the study. Mean weight loss was 2.25 kg (Cohen's d=0.12; P=0.03). There were no significant changes in PANSS total scores, SAS scores, or metabolic parameters. Switching patients to quetiapine, appears to be a viable strategy for managing olanzapine-induced weight gain as indicated by this 10-week open-label study. Prospective controlled trials of longer duration and larger number of subjects are needed.

A smart grid refers to a modernization of the electricity system that brings intelligence, reliability, efficiency and optimality to the power grid. To provide an automated and widely distributed energy delivery, the smart grid will be branded by a two-way flow of electricity and information system between energy suppliers and their customers. Thus, the smart grid is a power grid that integrates data communication networks which provide the collected and analysed data at all levels in real time. Therefore, the performance of communication systems is so vital for the success of smart grid. Merit to the ZigBee/IEEE802.15.4std low cost, low power, low data rate, short range, simplicity and free licensed spectrum that makes wireless sensor networks (WSNs) the most suitable wireless technology for smart grid applications. Unfortunately, almost all ZigBee channels overlap with wireless local area network (WLAN) channels, resulting in severe performance degradation due to interference. In order to improve the performance of communication systems, this paper proposes an optimal throughput and self-adaptability of ZigBee/IEEE802.15.4std for smart grid.