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This paper aims to study the mechanism of glass deep-hole micro-drilling by the Laser-Induced Plasma-Assisted Ablation (LIPAA) process. The Micro-drilling of glass was studied under various laser i...

Let G be a finite group and V(G) be the set of all non-central conjugacy classes of G. Consider the conjugacy class graph Γ(G) of G which is defined as follows: its vertex set is the set V(G) and t...

The seedless barberry, ‘Bidaneh,’ is one of the most important cultivated small fruits in Iran. This cultivar is propagated only by suckers, and so, the establishment of large-scale orchards is not...

Pistachio is one of the most important and high economic nut crops in the world. In the present research, the phenological and pomological traits of twenty superior male genotypes (MG) and twenty s...

The authors aim to present a model that examines the constructs affecting the quality of accounting education at the undergraduate level in the context of Iran. To reach a conclusion, they use grou...

Background: Patients with type-2 diabetes have poor adherence to the therapeutic regime. It can result in various complications in body systems associated with undesirable metabolic control. Purpose: The present study aimed to explore the inhibitors of medication adherence in patients with type-2 diabetes. Patients and methods: This was a qualitative study using a conventional content analysis method. Participants were 12 patients with type-2 diabetes referred to the diabetes unit in Saghez, Kurdistan Province in 2015. The purposive sampling method was used with a maximum variation in sampling, and data collection was continued until data saturation was achieved. Semi-structured interviews were used for data collection. Interviews were recorded and immediately transcribed verbatim. Results: Data analysis led to the development of four main categories including disbelief in medical explanatory/prescriptive knowledge, lived experiences of the disease, challenges of everyday life, and interactive/economic challenges. The main inhibitors were the patient's understanding of his/her own physical status and strategies used for maintaining the internal balance. Healthcare providers need to take patients' perceptions into account when they are prescribing medicinal diets. Another inhibitor was the incidents of everyday life, including economic and social challenges, and interactions to receive education and skills for living with the disease. Conclusion: Beliefs of the medical team and patients should be brought closer to each other, and patients' trust in the medical team should be increased. Nurses should consider the unique experience of every patient when giving healthcare recommendations, and try to limit the existing challenges as much as possible.

Seedless barberry (Berberis vulgaris L. var. asperma) is cultivated in arid and semi-arid areas of Iran. It is widely used as a food additive. Thirty-nine morphological characteristics were evaluat...

Elder abuse is the result of different socio-economic, cultural, psychological and individual factors. The aim of this study was to investigate the individual contexts which are relevant to elder a...

We conducted this research based on a qualitative approach to describe the opinions of older widows and widowers on remarriage obstacles. Based on purposive sampling and inclusion criteria, we chose 48 participants on maximum diversity of sex, age, education, employment, and socioeconomic status. Two thirds of the participants were female, 40% had spent more than 10 years widowed, and 65% were living with their children. We collected data individually through semistructured, face-to-face interviews. Based on conventional content analyses, 2 independent researchers implemented data analysis manually. Barriers to remarriage were finally categorized into 4 main themes: personal, normative, interactive, and financial factors. Results of this study showed that older people are more concerned about public opinions and social norms surrounding remarriage. As long as these thoughts and norms are not changed, the concept of remarriage among widows and widowers remains a vital taboo and concern.

Clean heat and power generation for industrial applications is a major challenge in the recent decade. Gasification is a clean thermochemical process to produce syngas through partial oxidation. In this paper, we develop an unsteady state kinetic model of gasification to produce syngas from petroleum residue and also evaluate the tar and char yield in the oxy-fuel conditions. Results showed that the oxy-fuel gasification can be used to produce high caloric value syngas with low emissions and costs. It is also found that the system pressure reduces the hydrogen yield, although it is not considerable. Modeling results validated against the experimental data and found to be in a good agreement.

Coal combustion has attracted a lot of interest by generating combined heat and power (CHP) due to low costs and high efficiency. However, one of the most important challenges in coal combustion is the environmental issues related to the process. In this article, the influence of some critical parameters, i.e., oxygen ratio, system pressure, residence time, and coal particle size, on output temperature and greenhouse gas emissions was evaluated using a kinetic model and an experimental study. Results showed that an increase in oxygen ratio leads to a significant increase in output temperature. It is also found that the particle size plays a negligible role in the process; smaller particles favor the production of gas products and higher combustion efficiencies. Modeling data validated against experimental measurements and were found to be in a good agreement.

This paper presents a goal programming model to predict the kinetic parameters of micro fluidized bed (Micro-FB) gasification of woody biomass in Qom, Iran. Qom has an abundance of waste woody biomass, and gasification can convert this residue into clean syngas. To do this, a kinetic model of biomass gasification was developed and validated against the experimental data available in the literature. The experiments were carried out in a Micro-FB in the presence of silica sand as the fluidization medium. To fully decompose the aromatic tars, the reaction temperatures were considered between 700°C and 1000°C with 100°C intervals. Results showed that the obtained activation energies strongly depend on the particle size for all the tested conditions.

There is an increasing interest in the conversion of municipal solid waste (MSW) due to its low cost and high potential for production of syngas and chemicals. Gasification is a promising thermochemical process to transform carbon-based fuels into a valuable fuel/syngas. In this article, an experimental study of air-gasification of municipal solid waste (MSW) using Ni-Cu/γ-Al2O3 nano catalysts was developed. The particle sizes were ranged from 0.3 mm to 0.35 mm and loaded into the Micro-FB system at the beginning of each experiment. The influence of type of catalysts, gasification temperature and catalyst loading on tar concentration, hydrogen yield, and char conversion was evaluated. Results showed that with increasing the gasification temperature, the hydrogen yield gradually increases from 25 to 34 g/kg fuel at 600°C and 24 to 32 g/kg fuel at 800°C when using Ni/γ-Al2O3 and Cu/γ-Al2O3 catalysts, respectively. It also found that the use of metal catalyst during the gasification process is an inf...

Gasification is a thermochemical process which converts organic fuels into a high caloric value syngas and other chemicals in the presence of a gasification agent. Tar generation represents the strongest barrier for the use of fixed-bed reactors for liquid fuel gasification, whereas sufficing is only possible with catalytic activities and expensive physical processing. In this work, a kinetic model of waste oil gasification was proposed which can be used a flexible model to provide a quantitative prediction of product yield of other fuels. Results were validated against the experimental measurements and showed a good agreement. In accordance with the modeling results, it was found that the greenhouse gas emission (GGE) of waste oil is higher than that of biomass materials, but the caloric value of the syngas generated is higher. The residence time was also recognized as an important design parameter to improve the syngas volume fraction.

Bimorph Piezoelectric Cantilevered (BPC) actuators have been of increasing interest in micro-manipulation processes during recent years. Due to properties such as transverse vibration, the performance and manoeuvrability have considerably improved, compared with conventional longitudinal piezoelectric actuators. Therefore, dynamic modelling of such actuators has been the centre of attraction. For this purpose, a target point on the actuator, e.g. the cantilever end tip, is usually considered as the actuator output. One degree of freedom lumped and continuous type dynamic models have been considered in prior research works. These types of modelling lead to two significant issues. First, the effect of higher vibrational modes in the actuator output is disregarded. Second, a minimum phase dynamic system is achievable for all target points regardless of position. In this paper, these two issues will be analytically and experimentally investigated. To this end, a linear continuous dynamic model for a general B...

In recent years, there has been great interest in the application of special nanoparticles on thermal oil recovery processes. In this article, based on nanotechnology, a new method for improving the performance of in-situ combustion process is presented. This work aims at studying the effect of engineered nanoparticles on the activation energy of crude oil oxidation reactions in relation to in-situ combustion processes. Similar to previous studies, three oxidation regions were observed in crude oil combustion in porous media and it was found that each particular nanoparticle has a different effect on each oxidation region. Results show a significant reduction in the activation energies of oxidation reactions, which is an indication of strong catalytic effect of nanoparticles. The catalytic efficiency of nanoparticles was found to be a function of nanoparticle type and concentration. From the results of this study, it can be pointed out that nanoparticles have the potential to be applied as an effective ad...

This paper presents a mathematical model of dressing of vitrified CBN grinding wheels by a diamond cup dresser. It predicts the dressing forces during rotary diamond cup dressing of vitrified CBN grinding wheels. This model is based on the fracture of abrasive grits, the fracture of the bond and the contact forces between dresser and grinding wheel. It considers the kinematical influences and in particular speed ratio and overlap factor during the dressing process. A Weibull distribution is used to predict the probability of bond fracture and also the collision number between the diamond grits of a rotating dresser and the CBN grits. This model is validated by experimental results. The theoretical modeling values agree reasonably well with the experimental results. On the basis of this model the effect of different cup dressing parameters on dressing forces is theoretically discussed with the aim of establishing appropriate dressing process configurations. Furthermore the presented model provides a basis ...

This article is in two parts describing the analysis and simulation of the disc dressing process and its effect on grinding performance. This part is concerned with the generation of the wheel surface by a diamond disc dresser. A new stochastic model of the prediction of wheel topography by diamond disc dresser is developed. It predicts the number of active grains per unit area and average slope of grains of the alumina grinding wheel. This model is based on the fracture of grits and it considers the kinematical influences of the disc dressing process on wheel surface. It is possible to analyze the effects of changing dressing parameters on the wheel topography. The topography that is generated from this model provides a basis for further prediction of the grinding performance.

This article is the second of two parts which analyze and simulate the disc dressing process and its effect on grinding performance. In the first part a new stochastic model of the prediction of wheel topography by diamond disc dresser was developed. It predicted the number of active cutting points per unit area and average slope of the asperities on an alumina grinding wheel. In the second part the effects of a disc dressing parameter which affect the wheel topography, specific energy, and workpiece surface roughness are evaluated. An upper bound analysis of a pyramidal indenter which moves on the workpiece is used for evaluation of the specific energy and modification of the grain tip. Modified grain tip was then used to predict the surface roughness of the ground workpiece. Dressing conditions with various speed ratios, cross feed rates and depths of dressing were investigated. In each case, the grinding forces and the surface roughness were experimentally measured, and then the effect of changing dres...

A new mathematical model of the dressing of grinding wheels by diamond disc dresser is developed. It predicts the dressing forces between the diamond grits of a rotating disc dresser and the grits of an alumina grinding wheel. This model is based on the fracture of grits, the fracture of the bond and the contact forces between the dresser and grits. It considers the kinematical influences and in particular speed ratio of the dressing process. Also a Weibull distribution was used to predict the probability of bond fracture. Dressing forces are measured experimentally and are compared with those calculated from the new model. Theoretical results closely match with the experimental findings. The dressing forces generated from this model provide a basis for further prediction of wheel topography and the grinding process.

The aim of this qualitative study is to explore the way people using modern health care perceive its consequences in Ouraman-e-Takht region of Iranian Kurdistan. Ouraman-e-Takht is a rural, highly mountainous and dry region located in the southwest Kurdistan province of Iran. Recently, modern health practices have been introduced to the region. The purpose of this study was to investigate, from the Ouramains’ point of view, the impact that modern health services and practices have had on the Ouraman traditional way of life. Interview data from respondents were analyzed by using grounded theory. Promoting survival was the core category that explained the impact that modern health practices have had on the Ouraman region. The people of Ouraman interpreted modern health practices as increasing their quality of life and promoting their survival. Results are organized around this core category in a paradigm model consisting of conditions, interactions, and consequences. This model can be used to understand the impact of change from the introduction of modern health on a traditional society. Key words: Iranian Kurdistan, Ouramanat region, modern health, promoting survival, grounded theory (Published: 14 May 2010) Citation: Int J Qualitative Stud Health Well-being 2010, 5 : 5069 - DOI: 10.3402/qhw.v5i2.5069