Prediction of unconfined compressive strength of pulverized fuel ash–cement–sand mixture

Motamedi, S.,Song, K. I.,Hashim, R. Springer Verlag (Germany) 2015 Materials and Structures Vol.48 No.4

<P>Recently, ground improvement has become much more feasible. Chemical stabilization is a quick and affordable approach to enhancing soil characteristics. An important avenue of research is discovering alternative materials for use in soil enhancement. Pulverized fuel ash (PFA), which is a waste byproduct of coal power plants, has been shown to reduce the environmental risks and costs involved in construction. In this study, a series of unconfined compressive tests were performed for various mixtures of cement, PFA, and sand; the tests considered both the curing period and the optimum moisture content (OMC). In addition, multiple variable linear regression was used to analyze laboratory data in order to obtain an empirical relationship that can be used to predict the unconfined compressive strength (UCS) of a PFA-cement-sand mixture. The accuracy of the model was verified using statistical indices. The first objective of this study was to assess the effects of PFA content on the UCS of the mixture. The second was to investigate the impact of the OMC on the UCS. The focal point of this study was its derivation of a relationship that can be used to estimate the UCS on the basis of existing variables. The results indicated that PFA can strengthen sand in terms of the UCS and that excessive PFA in a mixture may adversely affect the UCS of a medium. Therefore, a mixture must have an optimum proportion of compounds. The OMC plays a vital role in enhancing UCS. The UCS of different mixtures can be predicted with an acceptable level of accuracy by using the relationship derived in this study.</P>

Tamoxifen Resistance and CYP2D6 Copy Numbers in Breast Cancer Patients

Motamedi, Sahar,Majidzadeh, Keivan,Mazaheri, Mahta,Anbiaie, Robab,Mortazavizadeh, Seyed Mohammad Reza,Esmaeili, Rezvan Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.12

Background: Breast cancer accounts about one million from total annual ten million new diagnosed cases of neoplasia worldwide and is the main cause of death due to cancer in women. Tamoxifen is the most popular selective estrogen receptor modulator used in anti estrogen treatments. Tamoxifen must be converted into its metabolite endoxifen for biologic effects; this conversion process is catalysed by highly polymorphic cytochrome P450 2D6 (CYP2D6). This study surveyed copy number variation of the CYP2D6 gene and its possible correlation with Tamoxifen resistance in breast cancer patients. Methods: This case control study was performed on samples taken from 79 patients with breast cancer who used tamoxifen in Yazd and Tehran Cities, Iran. Real time reactions were conducted for 10 healthy samples using the comparative $C_t$ (Cycles threshold) method, each pair of genes being compared and samples with ratios around 1 were taken as control samples. Proliferation reactions were done by Real-Time PCR ABI Prism 7500. All registered data were transformed into SPSS 15 program and analyzed. Results: Efficiency of PCR for both CYP2D6 and ALB genes was 100%. From all 23 drug resistant patients 21.7% had one copy, 47.8% two copies and 30.4% had three copies. Also from all 56 drug sensitive patients, 26.8% had one copy, 51.8% two copies and 21.4% had three copies. The percentage of patients with one and two copies was similar between two groups but patients with three copies were more likely to belong to the drug resistant group more. Odd ratios for one and two copies were 0.759 and 0.853 respectively, indicating possible protective effects while that for three copies was 1.604. Conclusions: Based on our study there is no significant link between CYP2D6 gene copy numbers and tamoxifen resistance in women with breast cancer. But more studies considering other influencing factors appear warranted.

Family Variables and Metabolic Control in Insulin-treated Adults with Diabetes

Babak Motamedi 한국간호과학회 2007 한국간호과학회 학술대회 Vol.2007 No.11

Optimization of FSW of Nano-silica-reinforced ABS T-Joint using a Box-Behnken Design (BBD)

Mahyar Motamedi Kouchaksarai,Yasser Rostamiyan Techno-Press 2023 Advances in nano research Vol.14 No.2

This experimental study investigated friction stir welding (FSW) of the acrylonitrile-butadiene-styrene (ABS) T-joint in the presence of various nano-silica levels. This study aim to handle the drawbacks of the friction stir welding (FSW) of an ABS T-joint with various quantity of nanoparticles and assess the performance of nanoparticles in the welded joint. Moreover, the relationship between the nanoparticle quantity and FSW was analyzed using response surface methodology (RSM) Box-Behnken design. The input parameters were the tool rotation speed (400, 600, 800 rpm), the transverse speed (20, 30, 40 mm/min), and the nano-silica level (0.8, 1.6, 2.4 g). The tensile strength of the prepared specimens was determined by the universal testing machine. Silica nanoparticles were used to improve the mechanical properties (the tensile strength) of ABS and investigate the effect of various FSW parameters on the ABS T-joint. The results of Box-Behnken RSM revealed that sound joints with desired characteristics and efficiency are fabricated at tool rotation speed 755 rpm, transverse speed 20 mm/min, and nano-silica level 2.4 g. The scanning electron microscope (SEM) images revealed the crucial role of silica nanoparticles in reinforcing the ABS T-joint. The SEM images also indicated a decrease in the nanoparticle size by the tool rotation, leading to the filling and improvement of seams formed during FSW of the ABS T-joint.

The Relationship between Family Function and Disease Control in Diabetics

Babak Motamedi 한국간호과학회 2009 한국간호과학회 학술대회 Vol.2009 No.10

Situation and Contributing Factors of Workplace Violence among Nurses in the Health Sector of Isfahan, Iran

Babak Motamedi 한국간호과학회 2009 한국간호과학회 학술대회 Vol.2009 No.10

Corrosion inhibition properties of a green hybrid pigment based on Pr-Urtica Dioica plant extract

M. Motamedi,B. Ramezanzadeh,M. Mahdavian 한국공업화학회 2018 Journal of Industrial and Engineering Chemistry Vol.66 No.-

The main aim of this research is studying the corrosion inhibition properties of the combination of praseodymium nitrate (PrN) and Urtica Dioica (UrDi) on mild steel in sodium chloride solution. Fourier transform infrared (FT-IR), ultraviolet-visible (UV-Vis), thermogravimetric analysis/differential thermogravimetry (TGA/DTG) and X-ray photoelectron spectroscopy (XPS) results confirmed complex formation between Pr cations and UrDi (Pr-UrDi). Electrochemical results revealed that the Pr-UrDi hybrid complex had significant influence on the mild steel corrosion protection (by inhibition efficiency of ca. 94%) in NaCl solution.

Emblems of the Sleep Societies Around the World

김근태,Motamedi Gholam K,조용원 대한수면학회 2022 sleep medicine research Vol.13 No.1

An emblem is a representative image and is different for each society. The images that symbolize sleep have similarities and differences between countries and cultures. This is an issue that everyone is familiar with but has never paid attention to. We obtained the information about the emblems from the website of each societies or personal communication with the executives around the world. The emblems of sleep societies represent the opposite concepts of night and day, designed to express its nationality, and several pictorial symbols related to sleep in their culture. Each society has its own identity and is devoted to sleep medicine. Intuitive concept of sleep is perceived differently in different cultures, and the sleep societies’ emblems contain their own identity as well as the concept of sleep. We believe this report may help promote the common interests of sleep medicine worldwide.

Seismic Response of Asymmetric Steel Isolated Structures Considering Vertical Component of Earthquakes

Faramarz Khoshnudian,Danoush Motamedi 대한토목학회 2013 KSCE JOURNAL OF CIVIL ENGINEERING Vol.17 No.6

The concept of isolated structure is to separate the structure from harmful effects of earthquakes by introducing bearing. Regarding earthquakes such as the Bam and Kobe records with relatively high vertical component amplitude, it is necessary to investigate the behavior of the base-isolated structures considering vertical component of the ground motions. For this purpose, a four-story building with different eccentricities supported on elastomeric isolators with different vibration periods and damping ratios as well as three different records is used to study the effects of vertical component of earthquakes on the seismic behavior of asymmetric steel isolated structures. A rubber isolator element is used to idealize the nonlinear behavior of the isolators and a linear elastic behavior is assumed for the superstructure. The results demonstrate the significant effect of the vertical component of earthquake on the responses of structure such as axial forces, local uplift of the columns, and overturning moment of the structure and shear force of beams. For the studied cases including vertical component of earthquakes increases the compressive axial force (more than 100%) in corner columns. In addition the vertical component of earthquake causes significantly augmentation of tensile axial force and therefore, it results local uplift phenomena in isolators. Ignoring the vertical component of earthquake with high vertical amplitude will result unacceptable estimation in beam shear force and for some cases this error reaches 100%. This error is more important while the eccentricity of structure is significant (30%). Overturning safety factor is reduced when the vertical component of earthquake was included and this effect is more significant under earthquakes with higher ratio of vertical to horizontal component of earthquake.

Selection of coagulant using jar test and analytic hierarchy process: A case study of Mazandaran textile wastewater

Asadollahfardi, Gholamreza,Zangooei, Hossein,Motamedi, Vahid,Davoodi, Mostafa Techno-Press 2018 Advances in environmental research Vol.7 No.1

Textile factories are one of the industries which its wastewater treatment is a challenging issue, especially in developing countries and a conventional treatment cannot treat all its pollutants properly. Using chemical coagulants is a technique for physical and chemical primary treatment of the wastewater. We applied jar test for selection of suitable coagulant among the five coagulants including alum, calcium hydroxide, ferrous sulfate, ferrous chloride and barium chloride for the effluent of wastewater in Mazandran textile factory located in Mazandran Province, Iran. In addition, jar test, we also used analytic hierarchy process (AHP) method considering criteria which included coagulation cost, sensitivity to pH change, the amount of sludge generation and side effects for coagulation. The results of the jar test indicated that calcium hydroxide was proper among the coagulants which it removed 92.9% total suspended solid (TSS), 70% dye and 30% chemical oxygen demand. The AHP analysis presented that calcium hydroxide is more suitable than other coagulants considering five criteria.