Jumps phenomenon elimination of a Duffing oscillator using pole placement control method

Reza Mahmoudi,Hosein Ghaffarzadeh,T.Y. Yang 국제구조공학회 2021 Smart Structures and Systems, An International Jou Vol.28 No.5

This paper presents a numerical and analytical study in the time-frequency domain to control the bifurcation and instability in a forced Duffing oscillator by a linear state feedback control. The proposed method evolves minimizing computational expenses of analytical approaches by an approximate method to suppress the responses of the dynamical system based on pole placement theory. The instability frequency range of Duffing oscillator is identified by approximate analytical methods. Bifurcation and jump points of Duffing oscillator are identified in the frequency domain by perturbation and harmonic balance methods for average and strong nonlinearity of the system, respectively. The Caughey method is used to linearize Duffing oscillator to solve system in the state space form. A linear state feedback controller with pole placement is applied to system in the time domain. The observed controlling force is added to approximate solution equation in frequency domain which vanished bifurcation length. The results reveal that the proposed method can be beneficial in reducing dynamic responses and eliminating jump points of system with high accuracy.

Lack of Associations between Vitamin D Metabolism-Related Gene Variants and Risk of Colorectal Cancer

Mahmoudi, Touraj,Karimi, Khatoon,Arkani, Maral,Farahani, Hamid,Nobakht, Hossein,Dabiri, Reza,Asadi, Asadollah,Vahedi, Mohsen,Zali, Mohammad Reza Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.2

Purpose: With regard to the protective effect of vitamin D against colorectal cancer (CRC), we evaluated genetic variants that might influence vitamin D metabolism: vitamin D receptor (VDR), vitamin D binding protein (GC), vitamin D 25-hydroxylase (CYP2R1), and vitamin D 25-hydroxy 1-alpha hydroxylase (CYP27B1). Materials and Methods: A total of 657 subjects, including 303 cases with CRC and 354 controls were enrolled in this case-control study. All 657 were genotyped for the four gene variants using PCR-RFLP methods. Results: In this study, no significant difference was observed for VDR (rs2238136), GC (rs4588), CYP2R1 (rs12794714), and CYP27B1 (rs3782130) gene variants in either genotype or allele frequencies between the cases with CRC and the controls and this lack of difference remained even after adjustment for age, BMI, sex, smoking status, NSAID use, and family history of CRC. Furthermore, no evidence for effect modification of the variants and CRC by BMI, sex, or tumor site was observed. Conclusions: Our findings do not support a role for VDR, GC, and CYP27B1 genes in CRC risk in our Iranian population. Another interesting finding, which to our knowledge has not been reported previously, was the lack of association with the CYP2R1 gene polymorphism. Nonetheless, our findings require confirmation and possible roles of vitamin D metabolism-related genes in carcinogenesis need to be further investigated.

Parathyroid Hormone Gene rs6256 and Calcium Sensing Receptor Gene rs1801725 Variants are not Associated with Susceptibility to Colorectal Cancer in Iran

Mahmoudi, Touraj,Karimi, Khatoon,Arkani, Maral,Farahani, Hamid,Nobakht, Hossein,Dabiri, Reza,Asadi, Asadollah,Zali, Mohammad Reza Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.15

Background: Substantial evidence from epidemiological studies has suggested that increased levels of calcium may play a protective role against colorectal cancer (CRC). Given the vital role of calcium sensing receptor (CaSR) and parathyroid hormone (PTH) in the maintenance of calcium homeostasis, we explored whether the rs1801725 (A986S) variant located in exon 7 of the CaSR gene and the rs6256 variant located in exon 3 of PTH gene might be associated with CRC risk. Materials and Methods: In this study 860 subjects including 350 cases with CRC and 510 controls were enrolled and genotyped using PCR-RFLP methods. Results: We observed no significant difference in genotype or allele frequencies between the cases with CRC and controls for both CaSR and PTH genes either before or after adjustment for confounding factors including age, BMI, sex, smoking status, and family history of CRC. Furthermore, no evidence for effect modification of any association of rs1801725 and rs6256 variants and CRC by BMI, sex, or tumor site was observed. In addition, there was no significant difference in genotype and allele frequencies between the normal weight (BMI < $25kg/m^2$) cases and overweight/obese (BMI ${\geq}25kg/m^2$) cases for the two SNPs. Conclusions: These data indicated that the CaSR gene A986S variant is not a genetic contributor to CRC risk in the Iranian population. Furthermore, our results suggest for the first time that PTH gene variant does not affect CRC risk. Nonetheless, further studies with larger sample size are needed to validate these findings.

Design Robust Artificial Intelligence Model-base Variable Structure Controller with Application to Dynamic Uncertainties OCTAM VI Continuum Robot

Omid Mahmoudi,Farzin Piltan,Omid Reza Sadrnia,Mahdi Jafari,Mehdi Eram 보안공학연구지원센터 2015 International Journal of Hybrid Information Techno Vol.8 No.1

Design a robust artificial intelligent nonlinear controller for second order nonlinear uncertain dynamical systems is one of the most important challenging works. This paper focuses on the design of a robust chattering free mathematical model-base artificial intelligence (fuzzy inference system) variable structure controller (MFVSC) for highly nonlinear dynamic continuum robot manipulator, in presence of uncertainties. In order to provide high performance nonlinear methodology, variable structure controller is selected. Pure variable structure controller can be used to control of partly known nonlinear dynamic parameters of continuum robot manipulator. In order to reduce/eliminate the chattering, this research is used the artificial intelligence (fuzzy logic) theory. The results demonstrate that the model base fuzzy variable structure controller with switching function is a model-based controllers which works well in certain and partly uncertain system. Lyapunov stability is proved in mathematical model-based fuzzy variable structure controller with switching (sign) function. This controller has acceptable performance in presence of uncertainty (e.g., overshoot=1%, rise time=0.9 second, steady state error = 1.6e-8 and RMS error=4.8e-8).

Evaluation of the Effect of Pentoxifylline on Cisplatin-Induced Testicular Toxicity in Rats

Ali Reza Fallahzadeh,Zohreh Rezaei,Hamid Reza Rahimi,Mehrazd Jafari Barmak,Hossein Sadeghi,Sadrollah Mehrabi,Seyed Mohammadreza Rabani,Iraj Ragerdi Kashani,Vahid Barati,Reza Mahmoudi 한국독성학회 2017 Toxicological Research Vol.33 No.3

Chemotherapy is associated with male infertility. Cisplatin (cis-diamminedichloro-platinum (II) (CDDP) as a chemotherapy medication used to treat a number of cancers has been reported to most likely induce testicular toxicity. Administration of antioxidants, such as pentoxifylline (PTX) may reduce some Adverse Drug Reactions (ADRs) of CDDP. Therefore, this study investigated the potentially protective effects of PTX on CDDP-induced testicular toxicity in adult male rats. For this purpose, 42 male rats were randomly divided into 7 groups. The rats were orally pretreated with PTX at the 3 doses of 75, 150, and 300 mg/kg once a day for 14 successive days. On the 14<SUP>th</SUP> day of the study, they were intraperitoneally (IP) administered with a single dose of CDDP (7 mg/kg). Finally, the sperm/testis parameters, serum levels of reproductive hormones, including testosterone, Luteinizing Hormone (LH), and Follicle Stimulating Hormone (FSH) as the pivotal endocrine factors controlling testicular functions, and histopathological changes of testis tissue were examined. Pretreatment with the two doses of 75 and 150 mg/kg PTX indicated significant increases in the sperm count and motility induced by CDDP administration. The right and significantly left testis weights were decreased following the treatment with 300 mg/kg of PTX plus CDDP. However, 75 mg/kg of PTX plus CDDP showed the best near-to-normal histopathological features. The results demonstrated that PTX alone enhanced some parameters, such as the sperm count, while reducing other parameters, including sperm fast motility and germ layer thickness. Furthermore, despite testosterone or LH levels, the mean serum FSH level was significantly augmented by the doses of 75 and 150 mg/kg. It was concluded that PTX administration cannot reduce CDDP-induced testicular toxicity even at high doses (e.g., 300 mg/kg), while it seemed to partially intensify CDDP toxicity effects at a dose of 75 mg/kg. Thus, further research is required in this regard.

Evaluation of the Effect of Pentoxifylline on Cisplatin-Induced Testicular Toxicity in Rats

Fallahzadeh, Ali Reza,Rezaei, Zohreh,Rahimi, Hamid Reza,Barmak, Mehrazd Jafari,Sadeghi, Hossein,Mehrabi, Sadrollah,Rabani, Seyed Mohammadreza,Kashani, Iraj Ragerdi,Barati, Vahid,Mahmoudi, Reza Korean Society of ToxicologyKorea Environmental Mu 2017 Toxicological Research Vol.33 No.3

Chemotherapy is associated with male infertility. Cisplatin (cis-diamminedichloro-platinum (II) (CDDP) as a chemotherapy medication used to treat a number of cancers has been reported to most likely induce testicular toxicity. Administration of antioxidants, such as pentoxifylline (PTX) may reduce some Adverse Drug Reactions (ADRs) of CDDP. Therefore, this study investigated the potentially protective effects of PTX on CDDP-induced testicular toxicity in adult male rats. For this purpose, 42 male rats were randomly divided into 7 groups. The rats were orally pretreated with PTX at the 3 doses of 75, 150, and 300 mg/kg once a day for 14 successive days. On the $14^{th}$ day of the study, they were intraperitoneally (IP) administered with a single dose of CDDP (7 mg/kg). Finally, the sperm/testis parameters, serum levels of reproductive hormones, including testosterone, Luteinizing Hormone (LH), and Follicle Stimulating Hormone (FSH) as the pivotal endocrine factors controlling testicular functions, and histopathological changes of testis tissue were examined. Pretreatment with the two doses of 75 and 150 mg/kg PTX indicated significant increases in the sperm count and motility induced by CDDP administration. The right and significantly left testis weights were decreased following the treatment with 300 mg/kg of PTX plus CDDP. However, 75 mg/kg of PTX plus CDDP showed the best near-to-normal histopathological features. The results demonstrated that PTX alone enhanced some parameters, such as the sperm count, while reducing other parameters, including sperm fast motility and germ layer thickness. Furthermore, despite testosterone or LH levels, the mean serum FSH level was significantly augmented by the doses of 75 and 150 mg/kg. It was concluded that PTX administration cannot reduce CDDP-induced testicular toxicity even at high doses (e.g., 300 mg/kg), while it seemed to partially intensify CDDP toxicity effects at a dose of 75 mg/kg. Thus, further research is required in this regard.

Activation of peroxymonosulfate using carbon black nano-spheres /calcium alginate hydrogel matrix for degradation of acetaminophen: Fe3O4 co-immobilization and microbial community response

Reza Darvishi Cheshmeh Soltani,Mansoureh Mahmoudi,Grzegorz Boczkaj,Alireza Khataee 한국공업화학회 2020 Journal of Industrial and Engineering Chemistry Vol.91 No.-

Herein, we focused on the degradation of acetaminophen (ACT) drug in liquid phase byperoxymonosulfate (PMS) activated by carbon black nano-spheres (CBNS). The nanostructured activatorwas immobilized into calcium alginate hydrogel matrix (CAHM) to avoid the washout of thefinenanostructures. The Langmuir modeling showed an insignificant contribution to the adsorption processin the removal of ACT. The basic pH conditions favored the decomposition of ACT. Among nutrients, thepresence of nitrogenous compounds including nitrite, nitrate and ammonium caused a little decrease inthe reactor performance, while the addition of phosphate ion improved the efficiency from 76.8% to81.9%. The results demonstrated the involvement of both SO4and OH radicals in the degradation ofACT and domination of SO4radicals in the degradation process. Co-immobilization of the CBNS withelectro-synthesized magnetite nanoparticles resulted in not only the enhanced reusability potential butalso improved the efficiency of the treatment process to 95.6%. Mineralization efficiency of the processwas not remarkable; however, the process produced an effluent with lower toxicity toward the microbialcommunity of the activated sludge.

Vibration response of smart concrete plate based on numerical methods

Reza Taherifar,Farhad Chinaei,Shahram Ghaedi Faramoushjan,Mohammad Hossein Nasr Esfahani,Shabnam Nasr Esfahani,Maryam Mahmoudi 국제구조공학회 2019 Smart Structures and Systems, An International Jou Vol.23 No.4

This research deals with the vibration analysis of embedded smart concrete plate reinforced by zinc oxide (ZnO). The effective material properties of structure are considered based on mixture rule. The elastic medium is simulated by orthotropic visco-Pasternak medium. The motion equations are derived applying Sinusoidal shear deformation theory (SSDT). The differential quadrature (DQ) method is applied for calculating frequency of structure. The effects of different parameters such as volume percent of ZnO, boundary conditions and geometrical parameters on the frequency of system are shown. The results are compared with other published works in the literature. Results indicate that the ZnO have an important role in frequency of structure.

Buckling analysis of concrete plates reinforced by piezoelectric nanoparticles

Reza Taherifar,Maryam Mahmoudi,Mohammad Hossein Nasr Esfahani,Neda Ashrafi Khuzani,Shabnam Nasr Esfahani,Farhad Chinaei 사단법인 한국계산역학회 2019 Computers and Concrete, An International Journal Vol.23 No.4

In this paper, buckling analyses of composite concrete plate reinforced by piezoelectric nanoparticles is studied. The Halphin-Tsai model is used for obtaining the effective material properties of nano composite concrete plate. The nano composite concrete plate is modeled by Third order shear deformation theory (TSDT). The elastic medium is simulated by Winkler model. Employing nonlinear strains-displacements, stress-strain, the energy equations of concrete plate are obtained and using Hamilton's principal, the governing equations are derived. The governing equations are solved based on Navier method. The effect of piezoelectric nanoparticles volume percent, geometrical parameters of concrete plate and elastic foundation on the buckling load are investigated. Results showed that with increasing Piezoelectric nanoparticles volume percent, the buckling load increases.

Patient-Specific Dosimetry in Radioligand Therapy (RLT) for Metastatic Prostate Cancer Using 177Lu-DKFZ-PSMA-617

Elahe Mahmoudi,Elahe Pirayesh,Mohammad Reza Deevband,Mahasti Amoui,Mehrdad Ghorbani Rad,Mahdi Ghorbani 대한핵의학회 2021 핵의학 분자영상 Vol.55 No.5

Purpose 177Lu-DKFZ-PSMA-617 is a promising treatment for patients with metastatic prostate cancer. Specific dosimetry for each patient is an important factor in planning the patient’s treatment process. This study aimed to perform an image-based absorbed dose calculation for the treatment of metastatic prostate cancer with 177Lu-DKFZ-PSMA-617. Methods The individualized patient dosimetry calculations were based on whole-body planar scintigraphy images acquired in 10 patients with a mean age of 71.4±6.07 years (range 63–85 years) at approximately 0–2 h, 4–6 h, 18–24 h, and 36–48 h after administration of the mean 6253±826.4 MBq (range 5500–7400 MBq) of 177Lu-DKFZ-PSMA-617. Time-activity curves were generated for various organs. For count conversion to activities, calibration factors were calculated. Finally, the absorbed dose for an individual cycle was calculated using IDIAC-DOSE 2.1 software. Results On average, the calculated absorbed dose for the kidneys and salivary glands were 0.46±0.09 mGy/MBq and 0.62±0.07 mGy/MBq, respectively. Conclusions Based on the results, the177Lu-PSMA-617 therapy is a safe method for the treatment of castration-resistant prostate cancer patients. Large inter-individual variations in organ dose were found, demonstrating the need for patientspecific dosimetry and treatment planning.