• Earthquakes and Structures
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• 제12권1호
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• pp.35-45
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• 2017

The current paper investigates the effect of the seismic pounding of neighboring buildings on the response of structures isolated by Triple Friction Pendulum Bearing (TFPB). To this end, a symmetric three-dimensional single story building is modeled for analysis with two specified levels of top deck and base deck, to capture the seismic response of the base isolators and building's roof. Linear elastic springs with different level of gaps are employed to calculate the impact between the buildings. Nonlinear Dynamic Time History Analyses (NDTHA) are conducted for seismic evaluation. Also, five different sizes with four different sets of friction coefficients are assumed for base isolators to cover a whole range of base isolation systems with various geometry configurations and fundamental period. The results are investigated in terms of base shear, buildings' drift and top deck acceleration of the superstructure. The results also indicate the profound effect of the stiffness of the adjacent buildings on the value of the impact they impose to the superstructure. Also, in situations of potential pounding, the increment of the fundamental period of the TFPB base isolator could intensify the impact force up to nearly five-fold.

• Asian Pacific Journal of Cancer Prevention
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• 제16권6호
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• pp.2403-2407
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• 2015

Background: Very few analytical studies are available on any association between stressful life events (SLE) and colorectal cancer (CRC), at least in Iran. The aim of this case control study was to determine the association between stressful life events (SLE) and colorectal cancer. Materials and Methods: This study was conducted in four hospital colonoscopy units in Tabriz city of Iran including 414 participants aged 40-75 years: 207 cases with CRC confirmed by pathology and colonoscopy findings and 207 controls free of neoplastic conditions were selected (from the same hospitals at the same period for the cases and after matching for age and sex). Stressful life events were assessed using a 43-item Holmes and Rahe Life Events Questionnaire. Multivariate logistic regression was used to estimate adjusted odds ratios for SLE and risk of CRC. Results: The stressful life event mean score in the case group was 141.3, in contrast to 63.8 in the control group (p<0.011). After adjusting for confounders, death of dear ones increased the risk of CRC (OR: 2.49; 95%CI: 1.41-5.13). Other types of stressful life events (family and husband disputes, serious occupational problems, unemployment of > 6 months, and Serious financial problems) were also associated with CRC, but without statistical significance. Conclusions: According to our findings, it seems that SLE may increase the risk of CRC.

• Asian Pacific Journal of Cancer Prevention
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• 제15권16호
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• pp.6531-6534
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• 2014

Background: In Iran, breast cancer is the most prevalent cancer in women and a major public health problem. Methods: A cross sectional study was carried out to determine knowledge on breast cancer and breast self-examination (BSE) practices of 384 females living in the city of Hamadan, Iran. A purposive sampling method was adopted and data were collected via face-to-face interviews based on a validated questionnaire developed for this study. Results: Among respondents 268 (69.8%) were married and 144 (37.5%) of the respondents reported having a family history of breast cancer. One hundred respondents (26.0%) claimed they practiced BSE. Level of breast cancer knowledge was significantly associated with BSE practice (p=0.000). There was no association with demographic details (p<0.05). Conclusion: The findings showed that Iranian women's knowledge regarding breast cancer and the practice of BSE is inadequate. Targeted education should be implemented to improve early detection of breast cancer.

• Asian Pacific Journal of Cancer Prevention
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• 제15권6호
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• pp.2771-2776
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• 2014

Background: Breast cancer screening and higher quality mammography have resulted in an increase in the diagnosis of ductal carcinoma in situ worldwide. We compared the incidence and other factors in our cases of ductal carcinoma in situ between two recent decades. Materials and Methods: Medical records of cases of ductal carcinoma in situ who had been admitted to the surgery wards of the Cancer Institute of Tehran, Iran were evaluated from March 1993 to March 2003 as phase 1, and from April 2003 to April 2013 as phase 2. Results: Ratio of ductal carcinoma in situ to overall breast cancer was 1.27 and 3.93 in phases 1 and 2, respectively. Rates of excisional or incisional biopsies versus core needle biopsies and clinically versus mammographically detected cases as well as median size of tumors dropped between the 2 phases while a substantial rise in the number of patients attending for screening was seen in this time period. Surgical treatments followed a trend from modified radical mastectomy and axillary lymphatic dissection toward breast conserving surgery and sentinel node dissection or no axillary intervention. Conclusions: Our study shows a considerable trend toward earlier detection of breast cancer and evolution of treatment strategies toward standard less invasive surgery of DCIS in Iran.

• Asian Journal of Business Environment
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• 제4권1호
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• pp.25-35
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• 2014

Purpose - Appropriate project management knowledge as well as its effective application in the construction industry increase construction quality and, therefore, reduce fatalities and destruction. Research design, data, and methodology - This study was conducted through a comparative analysis of earthquake fatalities in Iran, Turkey, Pakistan, Indonesia, China, Haiti, Japan, and the United States of America. The data was analyzed using a frequency study. The analysis contrasts the fatalities of some of the strongest earthquakes around the world between 1960 and 2010. Results - Poor quality construction practices and a lack of effective application of project management knowledge play a major role in the vast destruction, high death toll, and dismal tragedies that are associated with earthquakes, especially in Iran. Conclusions - Despite the history of tragic earthquakes and their continuing recurrence, this study attempts to make governments, companies, and disaster management personnel aware of the dangers of poor quality construction and the deficient application of project management knowledge and, further, accentuates effective ways to prevent the probability of serious damage in future. This study contains valuable information on the effects of project management application towards reducing earthquake fatalities and destruction.

• 폴리머
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• 제38권4호
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• pp.449-456
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• 2014

Ternary blends of poly(L-lactic acid) (PLLA), poly(${\varepsilon}$-caprolactone) (PCL) and polyethylene oxide (PEO) were produced with different concentrations of components via melt blending. By leaching the PEO from the samples by water, porous materials were obtained with potential application for bio scaffolds. Sample porosity was evaluated by calculating the ratio of porous scaffold density (${\rho}^*$) to the non-porous material density (${\rho}_s$). Highest porosity (51.42%) was related to the samples containing 50 wt%. of PEO. Scanning electron microscopy (SEM) studies showed the best porosity resulted by decreasing PLLA/PCL ratio at constant concentration of PEO. Crystallization behavior of the ternary blend samples was studied using differential scanning calorimetry (DSC). Results revealed that the crystallinity of PLLA was improved by addition of PEO and PCL to the samples. The porosity plays a key role in governing the compression properties. Mechanical properties are presented by Gibson-Ashby model.

• Asian Pacific Journal of Cancer Prevention
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• 제14권1호
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• pp.39-42
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• 2013

Background: Breast cancer is the most frequently occurring cancer among Iranian women; however limited studies have been conducted to address survival rates. Objective: The objective was to examine survival rates in Tabriz (Northwest of Iran) and comparing with those of data reported from other cities and countries. Methods: Survival rates were calculated for one, three, five, seven and ten years for 271 breast cancer patients referred to one university clinic during 1997-2008. Results: Survival analysis demonstrated a lower survival rate compared to western countries. Conclusions: Survival rates for our patients are similar/better than other cities in Iran, but lower than certain European countries and the US. Further studies with a higher number of patients are now required.

• Asian Pacific Journal of Cancer Prevention
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• 제14권1호
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• pp.27-30
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• 2013

Background: Salivary gland tumors (SGT) are one of the most complex human neoplasms, demonstrating variations in their clinicopathological profile related to racial and geographic differences. Few studies with large samples have been reported in Iran. We here investigated a large group of patients in southern Iran. Materials and Methods: In this retrospective study, all cases of primary epithelial salivary gland tumors, which had been recorded in a 5 years period from 2005-2009, were enrolled. Clinical data such as histopathologic type and site of the lesion as well as patients' age and gender were analyzed. Results: Data of 366 cases of SGTs were recorded. Pleomorphic adenoma (80.2%) and adenoid cystic carcinoma (46.6%) were the most common benign and malignant neoplasms. Male to female ratio (M/F) and the mean age of patients were 1:1.05 and 37.7 for benign tumors while they were 1.2:1 and 50.6 for malignant tumors, respectively. Parotid and minor salivary glands were involved more frequently. Conclusions: Although the salivary gland tumours encountered were similar in most of their characteristics to those reported in other countries, some differences such as relative frequency and age and gender prevalence were discovered. These findings should help surgeons and pathologists for more accurate diagnosis, management and treatment.

• Structural Engineering and Mechanics
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• 제60권1호
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• pp.31-50
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• 2016

During the recent years, resistance mechanisms of reinforced concrete (RC) buildings against progressive collapse are investigated extensively. Although a general agreement is observed about their qualitative behavior in technical literature, there is not such a comprehensive point of view regarding the quantitative methods for predicting collapse resistance of RC members. Therefore, in the present study a simplified theoretical method is developed in order to predict general behavior of RC frames under the column removal scenario. In the introduced method, the robustness of the frame is extracted based on the capacity of the beams. The proposed method expresses ultimate arching and catenary capacities of the beams and also obtains the corresponding vertical displacements. Based on the calculated capacities, the introduced method also provides a quantitative assessment of structural robustness and determines whether or not the collapse occurs. The capability of the method is evaluated using experimental results in the literature. The evaluation study indicates that the proposed theoretical procedure can establish a reliable foundation for progressive collapse assessment of RC frame structures.

• Steel and Composite Structures
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• 제28권6호
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• pp.759-766
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• 2018

Friction Stir Welding (FSW) is a solid-state process, where the objects are joined together without reaching their melting point. It has been shown that this method is a suitable way to join dissimilar aluminium alloys. The current article employed hole drilling technique to measure the residual stress distribution experimentally in different zones of dissimilar aluminium alloys AA6061-T6 and AA7075-T6 Butt welded using FSW. Results are compared with those of similar AA6061-T6 plates joined using a conventional fusion welding method called tungsten inert gas (TIG). Also, the evolution of the residual stresses in the thickness direction was investigated, and it was found that the maximum residual stresses are below the yield strength of the material in the shoulder region. It was also revealed that the longitudinal residual stresses in the joint were much larger than the transverse residual stresses. Meanwhile, Vickers micro hardness measurements were performed in the cross-section of the samples. The largest hardness values were observed in the stir zone (SZ) adjacent to the advancing side whereas low hardness values were measured at the HAZ of both alloys and the SZ adjacent to the retreating side.