On the use of the Lagrange Multiplier Technique for the unilateral local buckling of point-restrained plates, with application to side-plated concrete beams in structural retrofit

Hedayati, P.,Azhari, M.,Shahidi, A.R.,Bradford, M.A. Techno-Press 2007 Structural Engineering and Mechanics, An Int'l Jou Vol.26 No.6

Reinforced concrete beams can be strengthened in a structural retrofit process by attaching steel plates to their sides by bolting. Whilst bolting produces a confident degree of shear connection under conditions of either static or seismic overload, the plates are susceptible to local buckling. The aim of this paper is to investigate the local buckling of unilaterally-restrained plates with point supports in a generic fashion, but with particular emphasis on the provision of the restraints by bolts, and on the geometric configuration of these bolts on the buckling loads. A numerical procedure, which is based on the Rayleigh-Ritz method in conjunction with the technique of Lagrange multipliers, is developed to study the unilateral local buckling of rectangular plates bolted to the concrete with various arrangements of the pattern of bolting. A sufficient number of separable polynomials are used to define the flexural buckling displacements, while the restraint condition is modelled as a tensionless foundation using a penalty function approach to this form of mathematical contact problem. The additional constraint provided by the bolts is also modelled using Lagrange multipliers, providing an efficacious method of numerical analysis. Local buckling coefficients are determined for a range of bolting configurations, and these are compared with those developed elsewhere with simplifying assumptions. The interaction of the actions in bolted plates during buckling is also considered.

Can the Serum Level of Myostatin be Considered as an Informative Factor for Cachexia Prevention in Patients with Medullary Thyroid Cancer?

Hedayati, Mehdi,Nozhat, Zahra,Hannani, Masoomeh Asian Pacific Journal of Cancer Prevention 2016 Asian Pacific journal of cancer prevention Vol.17 No.no.sup3

Thyroid cancer, the most common endocrine neoplasia, consists of four main types of carcinomas: papillary, follicular, and anaplastic, all with thyroid follicular origin, and medullary thyroid cancer (MTC) related to para-follicular cells. Cronic diseases such as diverse cancers may be associated with cachexia, especially at advanced stage. Cancer-induced cachexia is associated with diminished quality of life, functional performance, reduced response to antitumor therapy, and increased morbidity and mortality. Myostatin (Mst) is one of the outstanding molecules in the skeletal muscle loss process in cancer and it may be released by both skeletal muscle and cachexia-inducing tumors. Recently changes in serum levels of Mst have been identified as an important factor of cancer-induced cachexia. The goal of this study was to assessserum Mst levels in MTC patients. In this descriptive and case-control study, 90 participants were selected, comprising 45 MTC patients (20 males, $29{\pm}13.9years$, 25 females, $29{\pm}14.5years$) and 45 control individuals (25 males, $23.1{\pm}11.6years$, 20 females, $31.5{\pm}14.4years$). Serum Mst was determined using an ELISA kit and body mass index (BMI) was calculated by weight and height measurements. The Kolmogorov Simonov test showed a normal distribution for log transformed Mst serum levels in both case and control groups. Geometric means were 5.9 and 8.2 ng/ml respectively, and a significant difference was found according to the independent t-test results (P<0.01). There was also a significant difference mean of Mst between females in control and MTC groups, but not for the males. Pearson correlation test showed no correlation between age and BMI with Mst serum levels. The findings of this study support the hypothesis that Mst serum levels may have a potential ability for early diagnosis of cachexia in MTC patients, especially in females.

Investigation and optimization of olefin purification in methanol-to-olefin process based on machine learning approach coupled with genetic algorithm

Amin Hedayati Moghaddam 한국화학공학회 2023 Korean Journal of Chemical Engineering Vol.40 No.5

In this study, the goal was to develop a robust model for prediction of the performance of a purification section of methanol to olefin (MTO) process based on machine learning approach. The optimum operating conditions were determined by performing a genetic algorithm as an optimization technique. Finding the optimum conditions caused a considerable decrease both in fixed capital investment (FCI) and working capital investment (WCI). To do this, the separation section of MTO process was investigated and modelled through artificial intelligence (AI). This separation section of MTO process is comprised of three columns: C2-stripper, deethanizer, and C3-stripprer. For each column, three operative parameters (number of stages, reflux ratio, and pressure) were selected and investigated. The performance of columns was assessed through monitoring the purity of products in top stream and energy consumption. The experimental layout was designed using response surface methodology (RSM). And the obtained data were used to develop artificial neural network (ANN) models for each column. Several structures of ANNs were investigated to select the optimum model parameters. The observations show good agreement between the real and predicted data.

Bird strike analysis on a typical helicopter windshield with different lay-ups

Reza Hedayati,Saeed Ziaei-Rad,Arameh Eyvazian,Abdel Magid Hamouda 대한기계학회 2014 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.28 No.4

In the current paper, bird strike to a typical helicopter windshield is investigated using smoothed particles hydrodynamic (SPH) finiteelement method. Five types of lay-ups in a windshield (single layer stretch acrylic, single layer glass, two-wall cast acrylic, acrylic withPolyvinyl butyral (PVB) interlayer and glass with PVB interlayer) is considered and in each case the thickness which prevents the birdfrom perforating the windshield is calculated. Since helicopters can have lateral movement in addition to their longitudinal movement,the effect of incident angle on the integrity of windshield is also investigated. Simulations showed that among the five cases presented,glass with PVB interlayer can be the best choice for being used in windshield against bird strike. Another conclusion is that for the sameinitial velocity, the angled impact can cause more damage in the windshield than the direct impact.

Medullary Thyroid Carcinoma - Circulating Status of Vaspin and Retinol Binding Protein-4 in Iranian Patients

Jabbari, Sepideh,Hedayati, Mehdi,Yaghmaei, Parichehreh,Parivar, Kazem Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.15

Background: Vaspin and Retinol binding protein-4 (RBP4) are new adipokines mainly produced by adipose tissue. Considering that medullary thyroid carcinoma (MTC) is a malignant neuroendocrine tumor, and to date the relationship between serum levels of vaspin and RBP4 with MTC has not been studied, in this matched case-control study we evaluated their possible significance to this tumor type. Materials and Methods: A total of 45 patients with MTC (21 males and 24 females) and 45 healthy persons as a control group (24 males and 21 females) were selected. The two groups were matched for age, sex and body mass index. Serum Vaspin and RBP4 levels were measured by enzyme-linked immunosorbent assay (ELISA) methods in both groups. Also, weight and height were measured and body mass index was calculated too. Results: In total, patients with MTC had significantly higher serum vaspin levels compared to the controls (0.52ng/ml vs. 0.45ng/ml, P=0.0241). However, no significant difference was found in serum RBP4 concentrations between the patients with MTC and the controls ($15.2{\pm}2.55{\mu}g/ml$ versus $15.1{\pm}3.34{\mu}g/ml$, p>0.05). Conclusions: The results of this study demonstrated that serum RBP4 levels in MTC patients are not significantly different from those found in healthy individuals and did not correlate with MTC. On the other hand, higher levels of serum vaspin are associated with an increased risk of MTC. Thus Vaspin may be a novel and promising biomarker for diagnosis or confirmation of MTC in conjunction other specific tumor markers.

Effectiveness of Phytogenic Feed Additive as Alternative to Bacitracin Methylene Disalicylate on Hematological Parameters, Intestinal Histomorphology and Microbial Population and Production Performance of Japanese Quails

Manafi, M.,Hedayati, M.,Khalaji, S. Asian Australasian Association of Animal Productio 2016 Animal Bioscience Vol.29 No.9

This study was conducted to evaluate the effects of phytogenic additive and antibiotic growth promoter in laying Japanese quails. One hundred and sixty five quails were divided into three groups of 5 replicates and 11 quails (8 females and 3 males) in each replicate. Treatment 1 was fed control diet, treatment 2 was fed control diet supplemented with 0.05% bacitracin methylene disalicylate as antibiotic growth promoter and treatment 3 was fed control diet supplemented with 0.1% phytogenic feed additive (PFA) for two periods of 3 weeks each from 37 to 42 weeks of age. Results showed that egg production, eggshell strength, eggshell weight, villus height and villus height to crypt depth ratio were significantly (p${\leq}$0.05) increased and feed consumption, feed conversion ratio, albumen, Haugh unit, cholesterol, low-density lipoprotein, alanine transaminase, gamma glutamyltransferase, alkaline phosphatase, high-density lipoprotein, triglyceride, number of goblet cell, crypt depth and intestinal bacterial population of Coliforms, Salmonella and E. coli were significantly (p${\leq}$0.05) decreased in PFA fed group. It is concluded that addition of PFA containing phytomolecules and organic acids as main ingredients could significantly improve the production parameters and the general health of laying quails as an alternative to antibiotic growth promoters.

Statistical assessment of starch removal from starchy wastewater using membrane technology

Javad Sargolzaei,Amin Hedayati Moghaddam,Jalal Shayegan 한국화학공학회 2011 Korean Journal of Chemical Engineering Vol.28 No.9

The present work deals with application of 2^(5-2) fractional factorial design (FFD) to evaluate the operating parameters on starch separation from synthetic starchy wastewater using a hydrophilic polyethersulfone membrane with 0.65 μm pore size in a plate and frame handmade membrane module. The analysis of variance (ANOVA) combined with F-test was also used to recognize non-significant terms. The performance of the filtration process was evaluated by calculating the COD removal percentage (rejection factor) and permeate flux. In this experiment, five input parameters were surveyed, including trans membrane pressure (TMP), flow and temperature of feed, pH and concentration of wastewater. In this experiment, real wastewater was not used but synthetic starchy wastewater was prepared using starch. Two models were obtained from experimental data, capable of predicting COD removal percentage and permeate flux in different conditions. The predicted values obtained from the regression models were close to the actual ones. For the reduction of fouling, cleaning in place (CIP) method was used.

Antibody-Mediated Resistance to Rhizomania Disease in Sugar Beet Hairy Roots

Jafarzade, M.,Ramezani, M.,Hedayati, F.,Mokhtarzade, Z.,Zare, B.,Sabet, M.S.,Norouzi, P.,Malboobi, M.A. The Korean Society of Plant Pathology 2019 Plant Pathology Journal Vol.35 No.6

Agrobacterium rhizogenes-mediated transformation of sugar beet hairy roots expressing single-chain variable fragment (scFv) was exploited to evaluate the efficacy of four antibody-based constructs for interfering with the Beet necrotic yellow vein virus infection. The scFv specific to a major coat protein of virus, p21, was targeted to various cellular compartments including the cytosol (pIC and pICC constructs), apoplast (pIA), and mitochondrion (pIM). After mechanical virus inoculation, most of the hairy root clones expressing scFv in the cytosol displayed low virus titers while the majority of transgenic hairy root clones accumulated antibody in outer membrane of mitochondria or apoplast were infected. This hairy root system provided an efficient and rapid approach to initially investigating root disease resistance like rhizomania prior to transform whole recalcitrant plants such as sugar beet.

Optimum location of second outrigger in RC core walls subjected to NF earthquakes

Hamid Beiraghi,Mansooreh Hedayati 국제구조공학회 2021 Steel and Composite Structures, An International J Vol.38 No.6

Seismic responses of RC core wall with two outriggers are investigated in this study. In the models analyzed here, one of the outriggers is fixed at the top of the building and the second is placed at different levels along the height of the system. Each of the systems resulting from the placement of the outrigger at different locations is designed according to the prescriptive codes. The location of the outrigger changes along the height. Linear design of all the structures is accomplished by using prescriptive codes. Buckling restrained braces (BRBs) are used in the outriggers and forward directivity near fault and far fault earthquake record sets are used at maximum considered earthquake (MCE) level. Results from nonlinear time history analysis demonstrate that BRB outriggers can change the seismic responses like force distribution and deformation demand of the RC core-walls over the height and lead to the new plastic hinge arrangement over the core-wall height. Plasticity extension in the RC core wall occurs at the base as well as adjacent to the outrigger levels. Considering the maximum inter-story drift ratio (IDR) demand as an engineering parameter, the best location for the second outrigger is at 0.75H, in which the maximum IDR at the region upper the second outrigger level is approximately equal to the corresponding value in the lower region.

Extensive Venous Tumor Thrombi in a Case of Malignant Melanoma: Role of 18F FDG PET/CT

Nahid Yaghoobi,Raheleh Hedayati,Hadi Malek,Mehdi Maghsudi 대한핵의학회 2022 핵의학 분자영상 Vol.56 No.5

The 18F-FDG PET/CT imaging is a non-invasive modality for diagnosis and staging of metastatic melanoma. Venous thromboembolism (VTE) is a common complication of cancers, which needs anticoagulant therapy. Tumor thrombosis (TT), on the other hand, is an infrequent complication of solid malignancies that may need aggressive management. Accurate diagnosis of TT and its differentiation from VTE may change patient management and avoid unnecessary anticoagulation treatment. The objective of this case is to introduce a patient with malignant melanoma presenting with extensive venous tumor thrombi with intense FDG uptake.