Predictions of wet natural gases condensation rates via multi-component and multi-phase simulation of supersonic separators

Seyed Heydar Rajaee Shooshtari,Akbar Shahsavand 한국화학공학회 2014 Korean Journal of Chemical Engineering Vol.31 No.10

Proper correction of water and heavy hydrocarbon dew points of sweet natural gases is essential from vari-ous technical and economical standpoints. Supersonic separators (3S) are proved to be capable of achieving these taskswith maximum reliability and minimal expenses. The majority of the previous articles have focused on the flow behaviorof pure fluids across a 3S unit. Multicomponent fluid flow inside 3S accompanied with condensation phenomenonwill drastically increase the complexity of the simulation process. We tackle this issue by considering a proper com-bination of fundamental governing equations and phase equilibrium calculations to predict various operating conditionsand composition profiles across two multi-component and multi-phase 3S units. Various Iranian sweet gases are usedas real case studies to demonstrate the importance of 3S unit practical applications. Simulation results clearly illustratethe effectiveness of 3S units for faithful dehydration of various natural gases, while successfully controlling its dewpoint, suitable for any practical applications. Conventional HYSYS simulation software is used to validate the simulationresults.

New composite traits for joint improvement of milk and fertility trait in Holstein dairy cow

Ghiasi, Heydar,Piwczynski, Dariusz,Sitkowska, Beata,Gonzalez-Recio, Oscar Asian Australasian Association of Animal Productio 2021 Animal Bioscience Vol.34 No.8

Objective: The objective of this study was to define a new composite trait for Holstein dairy cows and evaluate the possibility of joint improvement in milk and fertility traits. Methods: A data set consisting 35,882 fertility related records (days open [DO], calving interval [CI], and number of services per conception [NSC], and total milk yield in each lactation [TMY]) was collected from 1998 to 2016 in Polish Holstein-Friesian breed herds. In this study TMY, DO, CI, and lactation length of each cow was used to obtain composite milk and fertility traits (CMF). Results: Moderate heritability (0.15) was estimated for composite trait that was higher than heritability of female fertility related traits: DO 0.047, CI 0.042, and NSC 0.014, and slightly lower than heritability of TMY 0.19. Favourable genetic correlations (-0.87) were estimated between CMF with TMY. Spearman rank correlation coefficients between breeding value of CMF with DO, CI, and TMY were high (>0.94) but with NSC were moderate (0.64). Selection on CMF caused favourable correlated genetic gains for DO, CI, and TMY. Different selection indices with different emphasis on fertility and milk production were constructed. The amount of correlated genetic gains obtained for DO and total milk production according to selection in CMF were higher than of genetic gains obtained for DO and TMY in selection indices with different emphasis on milk and fertility. Conclusion: The animal selection only based on a composite trait - CMF proposed in current study would simultaneously lead to favourable genetic gains for both milk and fertility related traits. In this situation CMF introduced in current study can be used to overcome to limitations of selection index and CMF could be useful for countries that have problems in recording traits, especially functional traits.

Polymeric membranes for the oxygen enrichment of air in sulfur recovery units: Prevention of catalyst deactivation through BTX reduction

Shooshtari Seyed Heydar Rajaee,Bastani Kiarash,Eslampanah Hamidreza 한국화학공학회 2023 Korean Journal of Chemical Engineering Vol.40 No.12

The modified Claus process is one of the most commonly used methods for hydrogen sulfide conversion into sulfur. However, one of the problems of this unit is the presence of benzene, toluene, and xylene (BTX) compounds at the inlet of the catalytic reactors that can deactivate the catalyst and decrease the efficiency of the sulfur recovery unit. One of the methods of BTX destruction in a furnace is to increase its temperature by increasing the oxygen concentration in the inlet air. In the present work, the application of polymeric membranes for the destruction of BTX was investigated by modeling and simulating a sulfur recovery unit and a membrane unit. The numerical results obtained from the simulations were validated successfully with industrial and experimental data for both sulfur recovery and membrane units. The simulation results for an industrial case study indicate that using five PI carbon membrane units with a total area of 26.82 m2 can increase the concentration of oxygen in the inlet air to a level of 60%. In this condition, the reduction in BTX compounds can also be increased up to 59%. Furthermore, for two-stage membrane configuration, by employing five two-stage membrane units with a total area of 58.3m2, the oxygen concentration increases to 82%, and the reduction in BTX compounds will be 75%.

Adaptive Control of Pure-feedback Systems with Nonlinear Parameterization via Time-scale Separation

Mehrnoosh Asadi,Heydar Toossian Shandiz 제어·로봇·시스템학회 2017 International Journal of Control, Automation, and Vol.15 No.1

In this paper an adaptive control approach for completely non-affine pure-feedback systems with nonlinearparameterization is proposed. By using the parameter separation technique and coupling it effectively withcombination of backstepping and time scale separation, a fast dynamical equation is derived from the original subsystem,where the solution is sought to approximate the corresponding ideal virtual/actual control input. In thisapproach, since designing state predictor to derive adaptation law of unknown parameters is omitted, our design ismore accurate and less complex. The closed loop stability and the state regulation of nonlinear parameterizationpure-feedback systems are all proved by new theorem in singular perturbation theory. Finally the simulation resultsare provided to demonstrate the effectiveness of the proposed approach.

Coordination Among Asian and European Countries University and it's Effect on the Tourist

Soudabeh Ghasemi,Heydar Lotfi,Sara Payamshad 세계문화관광학회 2011 Conference Proceedings Vol.12 No.-

The subject of this research is the cooperation of the a university of Islamic countries and its affect on tourism .Bearing am mind the definition of tourism it can be said that vocational holidays only restricted to enjoinment and sigh seeing but tourist is a person who travel from the point of departure to the destination with a deter mind seal or with the view of learning and appritiating or investing. Travel for learning cultures and tradition are called vocation which is for learning the social culture and tradition of group observing .there fore all scientific conferences fall in to the category of tourism. In the broad sence of meaning operas festival teatures and concerts can be also consider as edujcational tourism.

Progressive collapse analysis of buildings with concentric and eccentric braced frames

Reza Jalali Larijani,Heydar Dashti Nasserabadi,Iman Aghayan 국제구조공학회 2017 Structural Engineering and Mechanics, An Int'l Jou Vol.61 No.6

In this study, the susceptibility of different symmetric steel buildings with dual frame system to Progressive Collapse (PC) was assessed. Some ten-story dual frame systems with different type of braced frames (concentrically and eccentrically braced frames) were considered. In addition, numbers and locations of braced bays were investigated (two and three braced bays in exterior frames) to quantitatively find out its effect on PC resistance. An Alternate Path Method (APM) with a linear static analysis was carried out based on General Services Administration (GSA 2003) guidelines. Maximum Demand Capacity Ratio (DCR) for the elements (beams and columns) with highest DCRs (DCRmoment and DCRshear) is given in tables. The results showed that the three braced bays with concentric braced frames especially X-braced and inverted V-braced frame systems had a lower susceptibility and greater resistance to PC. Also, the results represented that the beams were more critical than columns against PC after the removal of column.

Comparison of the Pullout Strength of Different Pedicle Screw Designs and Augmentation Techniques in an Osteoporotic Bone Model

Gorkem Kiyak,Tevfik Balikci,Ahmed Majid Heydar,Murat Bezer 대한척추외과학회 2018 Asian Spine Journal Vol.12 No.1

Study Design: Mechanical study. Purpose: To compare the pullout strength of different screw designs and augmentation techniques in an osteoporotic bone model. Overview of Literature: Adequate bone screw pullout strength is a common problem among osteoporotic patients. Various screw designs and augmentation techniques have been developed to improve the biomechanical characteristics of the bone–screw interface. Methods: Polyurethane blocks were used to mimic human osteoporotic cancellous bone, and six different screw designs were tested. Five standard and expandable screws without augmentation, eight expandable screws with polymethylmethacrylate (PMMA) or calcium phosphate augmentation, and distal cannulated screws with PMMA and calcium phosphate augmentation were tested. Mechanical tests were performed on 10 unused new screws of each group. Screws with or without augmentation were inserted in a block that was held in a fixture frame, and a longitudinal extraction force was applied to the screw head at a loading rate of 5 mm/ min. Maximum load was recorded in a load displacement curve. Results: The peak pullout force of all tested screws with or without augmentation was significantly greater than that of the standard pedicle screw. The greatest pullout force was observed with 40-mm expandable pedicle screws with four fins and PMMA augmentation. Augmented distal cannulated screws did not have a greater peak pullout force than nonaugmented expandable screws. PMMA augmentation provided a greater peak pullout force than calcium phosphate augmentation. Conclusions: Expandable pedicle screws had greater peak pullout forces than standard pedicle screws and had the advantage of augmentation with either PMMA or calcium phosphate cement. Although calcium phosphate cement is biodegradable, osteoconductive, and nonexothermic, PMMA provided a significantly greater peak pullout force. PMMA-augmented expandable 40-mm four-fin pedicle screws had the greatest peak pullout force.

Ion-association dispersive liquid–liquid microextraction of trace amount of gold in water samples and ore using Aliquat 336 prior to inductivity coupled plasma atomic emission spectrometry determination

Naeemeh Zari,Jalal Hassan,Kourosh Tabar-Heydar,Seyyed Hamid Ahmadi 한국공업화학회 2020 Journal of Industrial and Engineering Chemistry Vol.86 No.-

An extraction method employing dispersive liquid–liquid microextraction (DLLME) and ICP-OES hasbeen developed for rapid separation, pre-concentration and determination of ultra-trace amount of Au(III). The extraction of the analyte was performed in the presence of a quaternary ammonium cation, NMethyl-N, N, N-trioctylammonium chloride, (Aliquat 336) as an extractant based on ion-associationextraction system.1-octanol and acetonitrile were used as extraction and disperser solvents, respectively. The variables affecting the extraction conditions were optimized. Calibration curve in the range of 0.3–100 ng mL 1, the detection limit of 0.09 ng mL 1, enrichment factor of 150 and extraction recovery of 74%were obtained. The precision (R.S.D. %) of the method was 6% for 5 replicates and recoveries of 10 ng mL 1Au(III). The combined DLLME method with ICP-OES can readily determine Au(III) at trace (mg L 1) levelusing only 10 mL of sample solution (tap, lake, and mining water) and ore sample without interference bythe matrices. This methodology is simple, fast, and low cost which can be used in routine analyticallaboratories.

Modeling of gas permeation through mixed matrix membranes using a comprehensive computational method

Majid Pakizeh,Salman Ofoghi,Seyed Heydar Rajaee Shooshtari 한국화학공학회 2016 Korean Journal of Chemical Engineering Vol.33 No.11

Three different morphologies can occur at the interface of inorganic and polymeric phases in mixed matrix membranes (MMMs). These morphologies are characterized by their different parameters such as partial pore blockage factor (α), polymer chain rigidification factor (β), and thickness of rigidified layer or void region. In this study, the morphology of three MMMs has been evaluated using a comprehensive computational method. The average absolute relative error (%AARE) is used as a criterion for optimizing three various MMM morphological parameters. According to the obtained optimum parameters, it was confirmed that two MMMs of C60/Matrimid and PVAc-Zeolite 4A have pore blockage and polymer chain rigidified defects. The results show that the morphology of ZIF-8/6FDA-DAM can be considered as an ideal morphology. After obtaining the morphological parameters, the permeability of the studied MMMs was predicted based on the modified Maxwell model and good agreement was observed between the calculated value and the experimental data.

Mid-length Pedicle Screws in Posterior Instrumentation of Scoliosis

Tevfik Balikci,Görkem Kıyak,Ahmed Majid Heydar,Motasim Khalid Bawaneh,Murat Bezer 대한척추외과학회 2019 Asian Spine Journal Vol.13 No.5

Study Design: Prospective analysis of collected data. Purpose: We determine the need for the use of mid-length pedicle screws (screws with 2.5-mm long increments) during posterior spinal instrumentation. Overview of Literature: Many biomechanical studies have been performed showing that increasing the pedicle screw insertion depth provides an improved resistance to pullout, cyclic loading, and derotational forces, but no intermediate length screws were used. Methods: We prospectively evaluated 120 patients who received posterior segmental instrumentation for structural scoliosis. Preoperatively, 91.44-cm long cassette anteroposterior (AP), lateral, and AP bending radiographs and multiplanar computed tomography were performed in all patients routinely. We measured chord length to determine the maximum probable screw length of all vertebrae. All pedicle screws were attempted to be placed as long as possible. The main intention was at least to engage the subcortical bone of the anterior vertebral cortex. Especially in the apical region, the screws were attempted to be inserted bicortically. The length, level, region, and side of each screw were recorded. Screws with 5-mm increments were called standard length screws (SLS), and middle-sized screws with 2.5-mm increments were called mid-length screws (MLS). Results: Of 2,846 pedicle screws inserted, 1,575 (55.4%) were SLS and 1,271 (44.6%) were MLS, demonstrating a need for MLS in scoliosis surgery (p<0.05). The need for MLS increased significantly in the thoracic region, apical vertebrae, and convex side (p<0.05). Conclusions: If anterior cortex engagement or longer placement of pedicle screws is intended during scoliosis surgery, for safer placement, screws with 2.5-mm increments should be available in posterior instrumentation systems.