Mohsen Karimi, Mohammad Pichan, Mehdi Sadri and Seyed Morteza Seyedjafari
This paper aims to investigate an improved control method and digital signal processor-based (DSP-based) digital implementation of three-phase standalone inverter. The proposed…
Abstract
Purpose
This paper aims to investigate an improved control method and digital signal processor-based (DSP-based) digital implementation of three-phase standalone inverter. The proposed method is performance developed of the proportional-resonant controller (PRC) with harmonic injection technique, aiming to improve load voltages quality under different loads, especially nonlinear loads. The advanced proposed multi-loop controller is consisted of current harmonic loops for suppressing odd harmonic, which are analyzed in discrete-time domain. Besides, the voltage loop is also used to compensate the output capacitor voltage.
Design/methodology/approach
The proposed method can effectively enlarge output voltage stability with low total harmonics distortion and improve the dynamic transient response. The other advantage of the proposed PRC is the injection of the selective harmonic without any additional calculation compensator.
Findings
The method is given the opportunity to be controlled exactly all harmful outputs with high-quality voltage referenced of the standalone inverter. The proposed method is implemented using a DSP processor (TMS320F28335) and is verified on the 10 kVA three-phase standalone inverter prototype.
Originality/value
The proposed method is performance developed of the PRC with harmonic injection technique, aiming to improve load voltages quality under different loads, especially nonlinear loads.
Details
Keywords
Iraqi universities in the aftermath of invasion in 2003 experienced extremely high levels of “post”-war violence and insecurity. The most widely known dimension of this violence…
Abstract
Iraqi universities in the aftermath of invasion in 2003 experienced extremely high levels of “post”-war violence and insecurity. The most widely known dimension of this violence is the shocking assassination campaign that killed hundreds of Iraqi academics. This paper provides an analysis of violence and insecurity in post-2003 that takes a broader optic and considers multiple forms of vulnerability to attack including insurgencies, sectarian conflict, and criminal violence. It also considers the various responses to the security dilemma taken by Coalition forces – principally counter-terrorism and stabilization efforts – and by Iraqi policy-makers and higher education communities, including security measures, politicization, ethno-sectarianization, and displacement.
Details
Keywords
Mehdi Ghazisaeedi, Leyland F. Pitt and S. Kamal Chaharsooghi
The potential impact of the internet on marketing is a common topic of discussion in marketing literature. However, there is still much debate on exactly what impact it will have…
Abstract
Purpose
The potential impact of the internet on marketing is a common topic of discussion in marketing literature. However, there is still much debate on exactly what impact it will have on developing countries. To perceive this impact world‐wide, it is essential to spread some light to the less investigated parts of the globe as well. This study aims to reach a better conceptual model for the internet's impact on marketing in Iran, by examining Iranian marketing managers' perceptions of the internet's impact on their key marketing activities and comparing the results with other parts of the world.
Design/methodology/approach
The paper employs a cross‐sectional research design involving self‐administered delivery and collection surveys to Iranian marketing decision makers.
Findings
The findings suggest that the impact of these new media will be to cause firms to redefine markets, marketing activity and value creation, although these changes are not dramatic.
Research limitations/implications
The findings reported here are snapshots in time. The internet's rapid evolution and growth demand that regular tracking with longitudinal designs be implemented.
Practical implications
Firms need to make changes in the marketing activities and market definitions and to try to reach the new ways that are created through the internet.
Originality/value
A modified model for the world wide web marketing that seems to be more realistic for developing countries is presented.
Details
Keywords
T. Hayat, Arsalan Aziz, Taseer Muhammad and A. Alsaedi
The purpose of this study is to examine the Darcy–Forchheimer flow of viscous nanoliquid because of a rotating disk. Thermophoretic diffusion and random motion aspects are…
Abstract
Purpose
The purpose of this study is to examine the Darcy–Forchheimer flow of viscous nanoliquid because of a rotating disk. Thermophoretic diffusion and random motion aspects are retained. Heat and mass transfer features are analyzed through convective conditions.
Design/methodology/approach
The governing systems are solved numerically by the shooting technique.
Findings
Higher porosity parameter and Forchheimer number Fr depict similar trend for both velocity profiles f' and g. Both temperature and concentration profiles show increasing behavior for higher Forchheimer number Fr. An increase in Prandtl number Pr corresponds to lower temperature profile, while opposite trend is noticed for thermal Biot number. Larger concentration Biot number exhibits increasing behavior for both concentration and its associated layer thickness.
Originality/value
To the best of the author’s knowledge, no such consideration has been given in the literature yet.