SYNTHESIS AND CHARACTERIZATION OF BIOACTIVE GLASS/FORSTERITE NANOCOMPOSITES FOR BONE AND DENTAL IMPLANTS

In this research, bioactive glass (BG) of the type CaO–P2O5–SiO2 and nanocrystalline forsterite (NF) bioceramic were successfully synthesized via sol–gel processing method. Heat-treatment process was done to obtain phase-pure nanopowders. After characterization of each sample, the nanocomposite samples were prepared by cold pressing method and sintered at 1000°C. The samples were fully characterized by X-ray powder diffraction (XRD), scanning electron microscope (SEM), energy dispersive spectroscopy (EDX), Fourier transform infrared spectroscopy (FTIR) analyses. The average nanocrystallite size was determined using the Debye-Scherrer’s formula 19.6 nm. The bioactivity was examined in vitro with respect to the ability of hydroxyapatite (HAp) layer to form on the surfaces as a result of contact with simulated body fluid (SBF). According to the obtained results, the prepared nanocomposite enhances the fracture toughness of the BG matrix without deteriorating its intrinsic properties as bioactivity

Analysing the asymmetric effects of inflation on real investment: the case of Iran

Using a threshold regression model and annual data (1960-2008), this paper examines thedeterminants of investment in Iran. We found that real GDP, the trade openness indexand inflation can influence investment. However, the effect of inflation on investmentfollows an asymmetry adjustment process. The threshold value for the rate of inflationhas endogenously been estimated to be at 11.9 per cent. If the annual rate of inflationexceeds this threshold, it will have a negative impact on investment. But, if inflationremains below this rate, not only the negative effect fades away but also rising prices canboost investment

How can Iran’s black market exchange rate be managed?

The Iranian currency (rial) depreciated on average 12.2 per cent per annum against the U.S dollar during the period 1960-1998 but, despite continued two-digit rates of inflation, the rial has witnessed only a meagre 1.7 per cent fall in its value in the post 1998 era. This paper examines this perplexing issue by identifying the major long-run determinants of the black market exchange rate. This paper uses the multivariate cointegration test, a threshold regression model and annual time series data (1960-2008) to determine exactly at what exchange rate the effect of relative prices on the exchange rate has been subject to an asymmetry adjustment process. We found that the relative CPIs in Iran and the U.S., total stock of foreign debt and the price of crude oil are the major long-run determinants of the black market exchange rate. However, the impact of relative prices (as measured by the magnitude of its elasticity) has significantly diminished from almost unity in the pre 1998 period to less than one-fourth since 1998. Based on our results, if oil prices continue to plunge, liquidity and inflation are out of control and at the same time Iran accumulates more external debt, the exchange rate will eventually exhibit an unprecedented and explosive depreciation in the coming years. No previous study has examined this issue using a threshold regression model without splitting the entire sample into two sections according to an endogenously determined threshold for the exchange rate

Analysing the asymmetric effects of inflation on real investment: the case of Iran

Using a threshold regression model and annual data (1960-2008), this paper examines the determinants of investment in Iran. We found that real GDP, the trade openness index and inflation can influence investment. However, the effect of inflation on investment follows an asymmetry adjustment process. The threshold value for the rate of inflation has endogenously been estimated to be at 11.9 per cent. If the annual rate of inflation exceeds this threshold, it will have a negative impact on investment. But, if inflation remains below this rate, not only the negative effect fades away but also rising prices can boost investment

A conceptual model based on an entrepreneurial approach to improve the efficiency of HRM

The present study was conducted with the goal of "providing a conceptual model based on an entrepreneurial approach to improve the efficiency of human resources management system". This research has been carried out in the framework of qualitative approach and using the research methodology of the foundation. Data gathering tools Semi-structured interviews were conducted using purposeful sampling with experts familiar with entrepreneurship topics and human resources management systems in the university (Tarbiat Modarres and Tehran universities) as well as experts in the field of transformation industry. The statistical population of the research is Iran Transfo Group and the sample size was 168 in the confirmatory factor analysis. In the first section, qualitative data were analyzed in the process of implementing the fundamental data theory in three stages of open coding, axial coding and selective coding. Based on this, a qualitative research model was designed. The results of this study indicate that the extraction of 324 code or initial concept from interviews and the analysis of 40 concepts from theoretical literature of research have been presented. The final model of research is presented in the form of a common model of fundamental data theory. In the second part of the research with quantitative approach, using confirmatory factor analysis, SPSS software was used to validate the research model. At this stage, the type of research is descriptive of the target dimension and it is considered to be a practical application. In order to collect data, a survey method and a researcher-made questionnaire have been used. The face and content validity of the questionnaire was evaluated by experts' opinion and the structural validity of the questionnaire was confirmed by confirmatory factor analysis and reliability of the questionnaire using the Kronbach's alpha coefficient (87%). To determine the normal distribution of data, the Kolmogorov-Smirnov test was used after the logarithmic transformation. The results of this test for all variables were greater than (0.05) and therefore had a normal distribution. Therefore, paired t-test was used to examine the status of the variables of HRM Entrepreneurship was used in the group of Iran Transfo companies. The results of this study showed that in the group of Iran Transfo companies there is a difference between the status quo and the favorable situation for all averages other than variables (emphasis on long-term performance, emphasis on efficacy, transparency and clarity of evaluation criteria, continuous and continuous training with wide applications , The transfer of specialized knowledge and creative thinking techniques, and the non-disclosure of confidentiality of employees (greater than 3). Therefore, it can be said that all components, general function, and all indicators other than those listed in Iran Transfo Co. are in good condition

Random walk and multiple structural breaks in Thai stock market

The Zivot and Andrews (1992) one-break and Lumsdaine and Papell (1997)two-break unit root tests are used to investigate the random walk hypothesis in Thaistock prices for the period December 1987 to December 2005. The results providestrong evidence that the Thai stock prices are characterized by a random walk,supporting this view that it is highly unlikely to make windfall profits in the Thai stockmarket using past price movements. Moreover, the dates of the endogenouslydetermined structural break interestingly coincided with the Asian crisis and worldrecessions

A study on the effects of human resource management on making change within organization: A case study of banking industry

This paper presents a study to find the effects of human resource management on empowering employees in banking industry. The proposed study designs a questionnaire and distributes it among 243 randomly selected employees of the first Iranian private banks called Saman. There are four hypotheses in this survey. The first hypothesis investigates whether employment type influences customer satisfaction or not. The second hypothesis of the survey studies whether training as well as empowering employees could increase organizational commitment or not. The third hypothesis of the survey investigates whether there is a positive relationship between creating motivation as well as job security and profitability. Finally, the last hypothesis of this survey tries to find out whether there is a positive and meaningful relationship between leadership style and supplier satisfaction. The implementation of some statistical tests confirms all four hypotheses of the survey

How can Iran’s black market exchange rate be managed?

The Iranian currency (rial) depreciated on average 12.2 per cent per annum against the U.S dollar during the period 1960-1998 but, despite continued two-digit rates of inflation, the rial has witnessed only a meagre 1.7 per cent fall in its value in the post 1998 era. This paper examines this perplexing issue by identifying the major long-run determinants of the black market exchange rate. This paper uses the multivariate cointegration test, a threshold regression model and annual time series data (1960-2008) to determine exactly at what exchange rate the effect of relative prices on the exchange rate has been subject to an asymmetry adjustment process. We found that the relative CPIs in Iran and the U.S., total stock of foreign debt and the price of crude oil are the major long-run determinants of the black market exchange rate. However, the impact of relative prices (as measured by the magnitude of its elasticity) has significantly diminished from almost unity in the pre 1998 period to less than one-fourth since 1998. Based on our results, if oil prices continue to plunge, liquidity and inflation are out of control and at the same time Iran accumulates more external debt, the exchange rate will eventually exhibit an unprecedented and explosive depreciation in the coming years. No previous study has examined this issue using a threshold regression model without splitting the entire sample into two sections according to an endogenously determined threshold for the exchange rate.Iran, Black market exchange rate, Threshold regression

MODELLING THE ASYMMETRIC EFFECTS OF INFLATION ON REAL INVESTMENT IN IRAN, 1959-2008

Using a threshold regression model and annual data (1960-2008), this paper examines the determinants of investment in Iran. We found that real GDP, the trade openness index and inflation can influence investment. However, the effect of inflation on investment follows an asymmetry adjustment process. The threshold value for the rate of inflation has endogenously been estimated to be at 11.9 per cent. If the annual rate of inflation exceeds this threshold, it will have a negative impact on investment. But, if inflation remains below this rate, not only the negative effect fades away but also rising prices can boost investment. Although investment exhibited a positive trend since 1990 it is not yet enough to guarantee high increases in income per capita and low rates of unemployment, given the high increase of population and labor force during the last years. We recommend economic polices geared at fostering not only public investment but also private sector investment in order to achieve the goals of higher income per capita and higher employment rates.Investment, Threshold Regression, Iranian economy.

Identifying Causal Factors Affecting the University Virtual Learning Pattern in Iran

E-learning development inIran can play a key role in growth and improvement of the countryinnear future. Main aim of this study was identifying the factors that haveinfluenced E-learning model in Iranian Universities. Present study wasconducted in-depth interviews with experts in the subject area. Snowballsampling method and 22 qualitative interviews were conducted in order to testthe findings of research. The results were analyzed in three ways: open, axialand selective. The findings indicated 80 effective marks in virtual academiceducational model categorized in 11 concept which includes: Organizationalissues, integrated management, competitive advantage, targeted educationalquality, knowledge management, technology, measurement, ease of access,innovation and creativity, Foresight and meritocracy. Finally, executivestrategies have been offered, which could be a key guide for virtual educationand its successful implementatio