Integrated Fault Tolerant Control for Saturated Systems with Additive Faults: A Comparative Study of Saturation Models

Mojtaba Hashemi,Ali Kamali Egoli,Mahyar Naraghi 제어·로봇·시스템학회 2019 International Journal of Control, Automation, and Vol.17 No.4

In this paper, the integrated design problem of Fault Estimation (FE) and Fault Tolerant Control (FTC)for saturated systems is considered. The system suffers from input saturation and L2-bounded disturbances. To designan adaptive observer-based FE, the actuator output measurements are not used, when the actuator is saturated,there exist new interactions between FE and FTC. In such a case the separation principle for FE and FTC designdoes not hold anymore. In this paper, a method is introduced for integrated design of FE and FTC, which guaranteesboundedness stability of such a system. To extract sufficient conditions for stability and minimum L2-gainperformance for disturbance rejection, the Modified Sector Condition (MSC) is employed for saturation modeling. Also, Quadratic Polytopic Differential Inclusion (QPDI) approach is developed for the comparative study. All conditionsare cast as Linear Matrix Inequality(LMIs) that can be evaluated in a single step. In a numerical example,the feasibility of the introduced method for stability guarantee is demonstrated and performance characteristics ofFE and FTC in disturbance rejection are compared for both modeling approaches.

Recent advances in liquid-phase microextraction techniques for the analysis of environmental pollutants

Hashemi, Beshare,Zohrabi, Parvin,Kim, Ki-Hyun,Shamsipur, Mojtaba,Deep, Akash,Hong, Jongki Elsevier 2017 Trends in analytical chemistry Vol.97 No.-

<P>The liquid-phase microextraction (LPME) method is a sample pretreatment technique that uses small volumes of organic solvents to extract a wide variety of analytes from different matrices prior to instrumental analysis. The development of these techniques focuses on providing simple, inexpensive, and environmentally friendly extraction procedures for sample preparation or pretreatment. In this review, the most recent developments in LPME techniques for the analysis of various environmental pollutants are summarized after being categorized into several groups such as dispersive liquid liquid microextraction (DLLME), ferrofluid-based microextraction, supramolecular-based liquid phase micro extraction, and vortex-assisted liquid liquid microextraction. Moreover, the extraction principles, the solvent production mechanism, and the historical development of the LPME techniques are also discussed. Finally, recent reports on the applications of these methodologies are reviewed. (C) 2017 Elsevier B.V. All rights reserved.</P>

Shape-controlled synthesis of zinc nanostructures mediating macromolecules for biomedical applications

Seyyed Mojtaba Mousavi,Gity Behbudi,Ahmad Gholami,Seyyed Alireza Hashemi,Zohre Mousavi Nejad,Sonia Bahrani,Wei-Hung Chiang,Lai Chin Wei,Navid Omidifar 한국생체재료학회 2022 생체재료학회지 Vol.26 No.1

Zinc nanostructures (ZnONSs) have attracted much attention due to their morphological, physicochemical, and electrical properties, which were entailed for various biomedical applications such as cancer and diabetes treatment, anti-inflammatory activity, drug delivery. ZnONS play an important role in inducing cellular apoptosis, triggering excess reactive oxygen species (ROS) production, and releasing zinc ions due to their inherent nature and specific shape. Therefore, several new synthetic organometallic method has been developed to prepare ZnO crystalline nanostructures with controlled size and shape. Zinc oxide nanostructures’ crystal size and shape can be controlled by simply changing the physical synthesis condition such as microwave irradiation time, reaction temperature, and TEA concentration at reflux. Physicochemical properties which are determined by the shape and size of ZnO nanostructures, directly affect their biological applications. These nanostructures can decompose the cell membrane and accumulate in the cytoplasm, which leads to apoptosis or cell death. In this study, we reviewed the various synthesis methods which affect the nano shapes of zinc particles, and physicochemical properties of zinc nanostructures that determined the shape of zinc nanomaterials. Also, we mentioned some macromolecules that controlled their physicochemical properties in a green and biological approaches. In addition, we present the recent progress of ZnONSs in the biomedical fields, which will help centralize biomedical fields and assist their future research development.

Designing a hand rest tremor dynamic vibration absorber using H₂optimization method

Mostafa Rahnavard,Mojtaba Hashemi,Farzam Farahmand,Ahmad F. Dizaji 대한기계학회 2014 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.28 No.5

An optimal single DOF dynamic absorber is presented. A tremor has a random nature and then the system is subjected to a random excitation instead of a sinusoidal one; so the H₂optimization criterion is probably more desirable than the popular H∞ optimization method and was implemented in this research. The objective of H₂optimization criterion is to reduce the total vibration energy of the system for overall frequencies. An objective function, considering the elbow joint angle, θ₂ , tremor suppression as the main goal, was selected. The optimization was done by minimization of this objective function. The optimal system, including the absorber, performance was analyzed in both time and frequency domains. Implementing the optimal absorber, the frequency response amplitude of θ₂ was reduced by more than 98% and 80% at the first and second natural frequencies of the primary system, respectively. A reduction of more than 94% and 78%, was observed for the shoulder joint angle, θ₁ . The objective function also decreased by more than 46%. Then, two types of random inputs were considered. For the first type, θ₁ and θ₂revealed 60% and 39% reduction in their rms values, whereas for the second type, 33% and 50% decrease was observed.

Evaluation of a Polycaprolactone/Gelatin/Lucilia sericata Larva Extract Nanofibrous Mat for Burn-Wound Healing

Seyedeh‑Sara Hashemi,Zhila Hayatdavoodi,Mehdi Kian,Nahid Hassanzadeh Nemati,Davood Mehrabani,Ali‑Akbar Mohammadi,Alireza Rafati,Mojtaba Ghaedi,Behzad Ghafari,Adnan Alizadeh Naini 한국섬유공학회 2023 Fibers and polymers Vol.24 No.11

Electrospun nanofibrous mats have shown great potential for dressing skin wounds. In this study, a nanofibrous mat composed of polycaprolactone (PCL), Gelatin (GLT), and Lucilia sericata larva extract (LSLE) was fabricated by the electrospinning method. The morphology of the fabricated nanofibrous mat and its morphological properties (fibers distribution frequency, fiber diameter, pore area, number of pores, and intersection density) were evaluated by scanning electron microscopy (SEM) and ImageJ software. The PCL/GLT/LSLE nanofibrous mat had well-branched and porous structure with a mean diameter of 500.2 ± 20.46. The presence of functional groups of PCL and GLT polymers in the structure of the PCL/GLT/LSLE mat was confirmed by Fourier-transform infrared spectroscopy (FTIR). Contact angle measurement and swelling behavior assessment showed that the PCL/GLT/LSLE mat had better surface wettability (75.67 ± 2.71) and hydrophilicity (241.8 ± 27.01) properties in comparison with the PCL and PCL/GLT mats. Findings from the MTT assay indicated the biocompatibility of the PCL/GLT/LSLE mat for human dermal fibroblasts (HDFs). In addition, the anchorage and proliferation of HDFs on the PCL/GLT/LSLE mat was confirmed by SEM. Macroscopic and histopathological evaluations were performed at the end of the 3, 7, and 14 days after the conduction of experimental burn wound injury in rats. The results indicated that grafting the skin wounds with the PCL/GLT/LSLE nanofibrous mat accelerated the wound closure and improved histopathological score compared to the other animal groups dressed with the PCL and PCL/GLT mats. In conclusion, the PCL/GLT/LSLE nanofibrous mat has promising potential for dressing skin wounds.

Ability of polymicrobial probiotic and mono-strain probiotic to reduce functional abdominal pain in children: a randomized clinical trial

Jafari Seyed Sajad,Hashemi Seyed Mojtaba,Sadeghi Bahman,Almasi-Hashiani Amir 대한소아청소년과학회 2022 Clinical and Experimental Pediatrics (CEP) Vol.65 No.12

Background: Chronic abdominal pain is a common problem in childhood.Purpose: Due to the prevalence of functional abdominal pain (FAP) and the importance of probiotics, this study aimed to compare the ability of 2 probiotics to reduce and improve FAP in children.Methods: This open-label randomized clinical trial included 116 children aged 5–15 years with FAPP who met the ROME-4 criteria and were referred to the gastrointestinal clinic of Amir-Kabir Hospital in Arak in 2020–2021. The children were randomly allocated to receive polymicrobial probiotic (PMP group) or mono-strain probiotic (MSP group) once daily for 4 weeks. The standard Wong-Baker Faces scale was used to assess symptom severity.Results: Of the 116 subjects, 62 (53.5%) were boys; the mean participant age was 7.39 years (standard deviation, 3.4 years). A significant intergroup difference (<i>P</i>=0.003) was observed in pain severity; 10.34% of children in the PMP group had no pain, while all patients in the MSP group reported low-degree pain. There was no intergroup difference in mean pain score (<i>P</i>=0.466), but it decreased over time in both groups (<i>P</i>= 0.001).Conclusion: Although significantly more children were painless in the PMP versus MSP group, no significant intergroup difference in pain score was noted and symptom severity decreased in both groups. A future study with a placebo group is recommended to validate our findings. .

Activated carbon@MgO@Fe3O4 as an efficient adsorbent for As (III) removal

Esmaeili Hossein,Mousavi Seyyed Mojtaba,Hashemi Seyyed Alireza,Chiang Wei-Hung,Ahmadpour Abnavi Somayeh 한국탄소학회 2021 Carbon Letters Vol.31 No.5

In this study, Fe3O4/MgO/Activated carbon composite was used to remove arsenic ion (As (III)) from aqueous media. To this end, Frangula Alnus was used to prepare activated carbon (AC) by calcination in the furnace at 700 °C for 4 h and was then used to synthesize the MgO/Fe3O4/AC composite. To study the surface properties of the composite, various analyses such as SEM, EDX/Mapping, FTIR, DLS, BET and VSM were applied. According to the BET analysis, the specifc surface area and average pore size of the Fe3O4/MgO/AC composite were obtained as 190.92 m2 /g and 7.57 nm, respectively, which showed that the aforementioned nanocomposite had a mesoporos structure with an excellent specifc surface area. Also, VSM analysis indicated that the composite had a superparamagnetic property and could be easily separated from the solution by a magnet. Moreover, the results of the As (III) sorption indicated that the highest uptake efciency was obtained 96.65% at pH=7, adsorbent dosage=0.13 g/L, t=35 min, T=45 °C and Co=6 mg/L. In addition, the pseudo-second-order model could better describe the kinetic behavior of the sorption process. Furthermore, Langmuir model was the best model to describe the equilibroium behavior of the As(III) ion sorption. Besides, according to the the thermodynamic study, enthalpy change and entropy change were obtained 58.11 kJ/mol and 224.49 J/mol.K, respectively, indicating that the sorption process was spontaneous and endothermic. According to the results, the Fe3O4/MgO/AC composite was a good adsorbent with the extraordinary properties, which can be used on an industrial scale.

Original Article : Evaluation of Antibody Response to Polysaccharide Vaccine and Switched Memory B Cells in Pediatric Patients with Inflammatory Bowel Disease

( Gholamhossein Fallahi ),( Asghar Aghamohammadi ),( Ahmad Khodadad ),( Mojtaba Hashemi ),( Payam Mohammadinejad ),( Hossein Asgarian Omran ),( Mehri Najafi ),( Fatemeh Farhmand ),( Farzaneh Motamed ) The Editorial Office of Gut and Liver 2014 Gut and Liver Vol.8 No.1

Background/Aims: Inflammatory bowel disease (IBD) is a chronic disease of the gastrointestinal tract, whose etiologies are still unknown. This study was performed to evaluate the humoral immune response in terms of B cell functions in selected IBD patients. Methods: Eighteen pediatric patients with IBD, including 12 cases of ulcerative colitis (UC) and six with Crohn disease (CD), were enrolled in this study. The pneumococcal vaccine was injected in all patients, and the IgG antibody level to the polysaccharide antigen was measured before and 4 weeks after injection. The B cell switch-recombination process was evaluated. Results: Five patients with IBD (three CD and two UC) had defects in B cell switching, which was significantly higher than in controls (p=0.05). Ten patients had a specific antibody deficiency and exhibited a higher frequency of bacterial infection than the healthy group. The mean increased level of IgG after vaccination was lower in IBD patients (82.9±32.5 μg/mL vs 219.8±59.0 μg/mL, p=0.001). Among the patients who had an insufficient response, no significant difference in the number of switched memory B-cell was observed. Conclusions: A defect in B lymphocyte switching was observed in pediatric IBD patients, and especially in those patients with CD. Owing to an increased risk of bacterial infections in those patients with antibody production defects, pneumococcal vaccination could be recommended. However, not all patients can benefit from the vaccination, and several may require other prophylactic methods. (Gut Liver 2014,8:24-28)

Ethanol Extracts of Achillea millefolium and Hypericum perforatum Low Anti-Toxoplasma Activity

Nozari, Shagayegh,Azadmehr, Abbas,Nassiri-Asl, Marjan,Jahani-hashemi, Hasan,Adine, Mohtaram,Javadi, Farzaneh,Shahnazi, Mojtaba,Saraei, Mehrzad KOREAN PHARMACOPUNCTURE INSTITUTE 2016 Journal of pharmacopuncture Vol.19 No.1

Objectives: This study was performed to determine the lethal and the inhibitory effects of ethanol extracts of Achillea millefolium (A. millefolium) and Hypericum perforatum (H. perforatum) on Toxoplasma gondii (T. gondii) RH strain tachyzoites in vitro. Methods: The tachyzoites were treated with concentrations of 10, 50, and 100 mg/mL of A. millefolium and H. perforatum extracts within 10, 30, and 45 minutes in the wells. The mortality rates of tachyzoites treated with extracts were determined by using alkaline methylene blue staining. Also, the tachyzoites in cell cultures were treated with concentrations of 50, 100, and 200 mg/mL of these extracts. The cell viability, inhibition concentration ($IC_{50}$), and selectivity were determined from MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assays. Results: In the cell-free in vitro study, all of tachyzoites were killed at concentrations of 100 mg/mL of both extracts while at concentration 10 mg/mL, the mortality was 4.53% - 5.31%. In the cell culture study, the values of the effective concentration ($EC_{50}$) were 215 and $153{\mu}g/mL$ and the selectivities were 0.73 and 0.69 for the A. millefolium and the H. perforatum extracts, respectively. Conclusion: We conclude that neither extracts has any significant effect on the tachyzoites of T. gondii in cell cultures.