A Characterization of Dedekind Domains and ZPI-rings

Rostami, Esmaeil Department of Mathematics 2017 Kyungpook mathematical journal Vol.57 No.3

It is well known that an integral domain D is a Dedekind domain if and only if D is a Noetherian almost Dedekind domain. In this paper, we show that an integral domain D is a Dedekind domain if and only if D is an almost Dedekind domain such that Max(D) is a Noetherian topological space as a subspace of Spec(D) with respect to the Zariski topology. We also give a new characterization of ZPI-rings.

High Quality DC-DC Boosting Converter Based on Cuk Converter and Advantages of Using It in Multilevel Structures

Rostami, Sajad,Abbasi, Vahid,Kerekes, Tamas The Korean Institute of Power Electronics 2019 JOURNAL OF POWER ELECTRONICS Vol.19 No.4

In this paper, a DC-DC converter is proposed based on the Cuk converter. The proposed converter has high efficiency and it can be used in multilevel DC-DC converters. A reduction of the inductors size in comparison to Cuk converter and a reduction in the inductors resistance negative effects on efficiency are the important points of the proposed converter. Its voltage ripple is reduced when compared to other converters. Its output voltage has a high quality and does not contain spikes. A theoretical analysis demonstrates the positive points of the proposed converter. The design and analysis of the converter are done in continues conduction mode (CCM). Experiments confirm the obtained theoretical equations. The proposed converter voltage gain is similar to that of a conventional Boost converter. As a result, they are compared. The comparison illustrates the advantages of the proposed converter and its higher quality. Furthermore, a prototype of the proposed converter and its combination with a 2x multiplier are built in the lab. Experimental results validate the analysis. In addition, they are in good agreements with each other.

The Commutativity Degree in the Class of Nonabelian Groups of Same Order

Rostami, Hojjat Department of Mathematics 2019 Kyungpook mathematical journal Vol.59 No.2

The commutativity degree of a finite group is the probability that two randomly chosen group elements commute. In this paper we give a sharp upper bound of commutativity degree of nonabelial groups in terms of their order.

Assessment of Tuta absoluta yield loss in Iranian tomato crops

Rostami E.,Madadi H.,Abbasipour H.,Fu J.,Cuthbertson A.G.S. 한국응용곤충학회 2021 Journal of Asia-Pacific Entomology Vol.24 No.4

The South American tomato pinworm, Tuta absoluta Meyrick (Lepidoptera: Gelechiidae), a devastating pest of tomato plants, originates from South America but it has been considered an invasive pest for Iran since 2010. To assess crop loss caused by this pest, a study was conducted in a 600 m 2 field under a randomised complete block design. The impact of different initial densities of T. absoluta, including control (without infestation), one, two, four, and eight T. absoluta eggs on each host plant in the first and second year was investigated with an additional treatment (16 pinworm eggs per host plant) used in the second year. Yield attributes including length and width of fruits, numbers of infested and intact fruits along with their weights were sampled and assessed on a weekly basis. In addition, the correlation between the number of galleries and these characteristics was also investigated. Crop loss data demonstrated that the effect of different infestation levels on fruit size and the weight of intact fruits was not significant over both years. However, the effect of treatment on the percentage and weight of infested fruits was shown to be significantly different in 2014 and 2015. Furthermore, there was a negative significant correlation between the number of galleries and weight of infested fruits in both years. Collectively, these results will be useful for enhancing pest management programs of T. absoluta in Iran

Effects of Plasma-Wall Interactions on Hydrogen Isotopes and Helium Plasma Particles in the JET-ILW Tokamak

Rostami S. Hesami,Motevalli S. M.,Fadaei F.,Mohammadi S. 한국물리학회 2020 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.77 No.12

Zero-dimensional global particle balance modeling was applied to the JET-ILW tokamak to investigate the particle balance in the main plasma and wall inventory, including the wall recycling effect, co-deposition, and sputtered particles. In this model, we used the fueling rate, based on the experimental work and vacuum pumping of the JET-ILW. Our modeling results were then compared with experimental data from the JET-ILW tokamak. A qualitative agreement was observed between the model results and the experimental data. In addition, this model could be a promising for studing the particle behavior in ITER-like reactors.

Magnetic Nanoparticle Immobilized N-Propylsulfamic Acid as a Recyclable and Efficient Nanocatalyst for the Synthesis of 2H-indazolo[2,1-b]phthalazine-triones in Solvent-Free Conditions: Comparison with Sulfamic Acid

Rostami, Amin,Tahmasbi, Bahman,Yari, Ako Korean Chemical Society 2013 Bulletin of the Korean Chemical Society Vol.34 No.5

N-Propylsulfamic acid supported onto magnetic $Fe_3O_4$ nanoparticles (MNPs-PSA) was used as an efficient and magnetically recoverable catalyst for synthesis of 2H-Indazolo[2,1-b]phthalazine-1,6,11(13H)-trione derivatives from the three-component, one-pot condensation reaction of phthalhydrazide, aromatic aldehydes and cyclic 1,3-diones, in good to excellent yields at $100^{\circ}C$ under solvent-free conditions. The catalyst was easily separated with the assistance of an external magnetic field from the reaction mixture and reused for several consecutive runs without significant loss of its catalytic efficiency. In order to compare, the synthesis of 2H-Indazolo[ 2,1-b]phthalazine-1,6,11(13H)-trione derivatives in the presence of catalytic amount of sulfamic acid (SA) under same reaction condition was also reported.

Structural characterization and RAW264.7 murine macrophage stimulating activity of a fucogalactoglucan from Colpomenia peregrina

Rostami, Zeynab,Tabarsa, Mehdi,You, SangGuan,Rezaei, Masoud Springer-Verlag 2018 Journal of food science and technology Vol.55 No.11

Applying SVM framework for modeling of CO₂ solubility in oil during CO₂ flooding

Rostami, Alireza,Arabloo, Milad,Lee, Moonyong,Bahadori, Alireza Elsevier 2018 Fuel Vol.214 No.-

<P><B>Abstract</B></P> <P>CO<SUB>2</SUB> solubility is one of the most important parameters that affects CO<SUB>2</SUB> flooding, because gas dissolution into crude oil results in oil swelling, viscosity reduction, IFT reduction, oil mobilization, and oil recovery improvement. Therefore, a better understanding of CO<SUB>2</SUB> solubility mechanisms and its influence on physical properties of crude oil are essential to any effective CO<SUB>2</SUB> flooding process. In this study, Least-Square Support Vector Machine (LSSVM) as a newly established soft computing algorithm is applied for developing a new correlative model for CO<SUB>2</SUB> solubility in both dead and live oil systems. CO<SUB>2</SUB> solubility in dead oil is basically affected by the oil saturation pressure (P<SUB>s</SUB>), oil specific gravity (<I>γ</I>), oil molecular weight (MW), and reservoir temperature (T). Moreover, the impact of bubble point pressure is considered in constructing the LSSVM model for the live oil. A number of statistical quality measures are utilized to assess and demonstrate the superior capability of the newly developed LSSVM model in comparison with the previous empirically derived correlations. The average absolute relative deviation (AARD) and coefficient of determination (R<SUP>2</SUP>) of 2.2783% and 0.9933 for the dead oil system, and 1.7432% and 0.9958 for the live oil system, respectively, verify the acceptable accuracy and efficient performance of the proposed LSSVM model over a wide range of dataset used in this study within the range of the used databank. However, the impact of CO<SUB>2</SUB> liquefaction pressure is ignored, the LSSVM model gives the best result. In conclusion, it is worth mentioning that the proposed LSSVM model can serve as an accurate correlative tool for fast and effective estimation of CO<SUB>2</SUB> solubility in both dead and live crude oils.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A new soft computing model is established for CO<SUB>2</SUB> solubility prediction in both dead and live oil systems. </LI> <LI> Several statistical parameters are utilized to demonstrate the superiority of the suggested SVM model. </LI> <LI> The performance of the developed model is compared with other literature correlations. </LI> <LI> The proposed model can serve as accurate tool for effective estimation of CO<SUB>2</SUB>-crude oil solubility. </LI> <LI> The impact of all input variables on the target values based on different techniques is determined. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Advance Rate Simulation for Hard Rock TBMs

Jamal Rostami,Ebrahim Farrokh,Chris Laughton,S. Safa Eslambolchi 대한토목학회 2014 KSCE JOURNAL OF CIVIL ENGINEERING Vol.18 No.3

The existing methods for estimating the advance rate of hard rock Tunnel Boring Machine (TBM) often involves estimation of themachine utilization in a direct or an indirect manner. These methods are based on empirical systems and are limited in their capacityfor incorporating new machine capabilities or including many of the geological features along the tunnel. As such, these models arenot used as often due to their shortcomings. The objective of this study is to offer some improvements by using a new approach forsimulating all activities. The basic idea in simulation techniques is to predict the duration of different activities based on theirrecorded time distributions from past case histories or from the early stages of a project. A simulation model contains a series ofoperations, which should be repeated for a certain number of cycles. In each cycle, the model selects an anticipated duration timefrom time distribution curves for each activity and by using a logical relationship between activities, being parallel or in series and thepossibility of activity overlaps, it assigns a duration for the whole cycle. This is then continued to finish the task at hand with requirednumber of cycles. In this case, the cycles are the TBM going through each stroke or penetration cycle. This study includes discussionof each activity or failure of each subsystem and assigned and related duration accounts for parallel activities, and offers a distributionof cycle time, and finally estimation of tunnel completion time. A comprehensive study was conducted to evaluate the requirementsfor California switch final location and also the work arrangements for locomotives and trains for different scenarios. Differentarrangements were programmed with Arena© simulation software using field data of a double shield TBM, which recently completeda water conveyance tunnel. The simulation results show a very good agreement with the actual values of TBM advance rate valuesand also show the possible variation of the time required for completion of different sections of this tunnel. The outcome of this studywas to establish a framework for arranging and modeling the main time components of TBM operation. This will provide a usefultool for developing reliable estimates of machine advance rate for specific site, ground condition, and machine type.

Nonlinear forced vibration of sandwich plate with considering FG core and CNTs reinforced nano-composite face sheets

Rasoul Rostami,Mohsen Irani Rahaghi,Mehdi Mohammadimehr 국제구조공학회 2020 Smart Structures and Systems, An International Jou Vol.26 No.2

Nonlinear vibration of sandwich plate with functionally graded material (FGM) core and carbon nano tubes reinforced (CNTs) nano-composite layers by considering temperature-dependent material properties are studied in this paper. Base on Classical plate theory (CPT), the governing partial differential equations of motion for sandwich plate are derived using Hamilton principle. The Galerkin procedure and multiple scales perturbation method are used to find relation between nonlinear frequency and amplitude of vibration response. The dynamic responses of the sandwich plate are also investigated in both time and frequency domains. Then, the effects of nonlinearity, excitation, power law index of FG core, volume fraction of carbon nanotube, the function of material variations of FG core, temperature changes, scale transformation parameter and damping factor on the frequency responses are investigated.