304 research outputs found

    Numerical Study of Fluid Flow in Dew Point Setting Unit Separators in Sarkhoun and Qeshm Gas Treating Company

    Get PDF
    ABSTRACT In this paper, in order to research the effects of separator plates geometry on fluid flow behavior is used from three types of plate with different tips -Round, sharp and flat (main geometry)-for simulation was used 2dimension and 3dimension with numerical finite volume model. Then plate has been modeled 2 dimensional and for purpose of droplet tracking in continuous phase (CH 4 ) has been used discrete phase model (DPM) with turbulence Reynolds stresses model (RSM). Also Gambit software is used for mesh generation and boundary conditions and fluent software is used for solution of governing equations. After simulation, effect of growing of droplet, plate tip geometry, density of liquid droplet in continuous phase, distance between plates and pressure drop was studied. The result of research compared with experimental result in outlet of separator at Sarkhoun and Qeshm gas treating company that has 90% compatibility. The simulation result has shown that plate with flat tip has more compatibility with relation to other plates in that has acceptable pressure drop and separation efficiency. Also effective parameters in improvement of separation process are growing and increase density of liquid droplet that plates with flat tip duo to their special geometry have more compatibility for separation with present condition. The result of research is shown that in applicable condition (Rate of flow and properties of fluid), performance of flat tip plate is better than two other types

    Data-driven system reliability and failure behavior modelling using FMECA

    Get PDF
    System reliability modelling needs a large amount of data to estimate the parameters. In addition, reliability estimation is associated with uncertainty. This paper aims to propose a new method to evaluate the failure behavior and reliability of a large system using failure modes, effects and criticality analysis (FMECA). Therefore, qualitative data based on the judgment of experts is used when data is not sufficient. The subjective data of failure modes and causes has been aggregated through the system to develop an overall failure index (OFI). This index not only represents the system reliability behavior but also prioritizes corrective actions based on improvements in system failure. In addition, two optimization models are presented to select optimal actions subject to budget constraint. The associated costs of each corrective action are considered in risk evaluation. Finally, a case study of a manufacturing line is introduced to verify the applicability of the proposed method in industrial environments. The proposed method is compared with conventional FMECA approach. It is shown that the proposed method has a better performance in risk assessment. A sensitivity analysis is provided on the budget amount and the results are discussed.Hadi A. Khorshidi, Indra Gunawan, and M. Yousef Ibrahi

    Evaluating the effect of a mixture of alcohol and acetic acid for otomycosis therapy

    Get PDF
    Introduction and objective: Otomycosis is a fungal infection of external auditory meatus. The acute form of the disease causes secretion and pruritus. The usual prescribed medicines for otomycosis are topical clotrimazole 1, amphotericin B and otosporin. The aim of the present study was to evaluate the efficacy of treatment with isopropyl alcohol and acetic acid for otomycosis. Materials and methods: In the present study 910 patients examined and those suspected to have otomycosis referred to medical mycology laboratory of Golabchi, Kashan. A questionnaire was also filled for each patient. Both direct and culture examinations were used to confirm otomycosis in the patients. Then the patients were treated with the mixture of isopropyl alcohol+acetic acid. Results: Out of 910 examined patients, 60 patients were suspected to have otomycosis and referred to medical mycology lab. Mycological examinations confirmed otomycosis in 52 patients (86.7). Most of the patients (78.8) were cured perfectly after therapy with the mixture of alcohol and acetic acid. After three weeks, in addition to elimination of clinical signs further smear showed no sign of disease. However in four patients there was a relapse of the disease. Conclusion: Due to therapeutic effect of the mixture of isopropyl alcohol and acetic acid for otomycosis, its low side effects and low rate of relapse, it is recommended to use this mixture for the treatment of otomycosis

    A Comprehensive Bibliometric Analysis on Social Network Anonymization: Current Approaches and Future Directions

    Full text link
    In recent decades, social network anonymization has become a crucial research field due to its pivotal role in preserving users' privacy. However, the high diversity of approaches introduced in relevant studies poses a challenge to gaining a profound understanding of the field. In response to this, the current study presents an exhaustive and well-structured bibliometric analysis of the social network anonymization field. To begin our research, related studies from the period of 2007-2022 were collected from the Scopus Database then pre-processed. Following this, the VOSviewer was used to visualize the network of authors' keywords. Subsequently, extensive statistical and network analyses were performed to identify the most prominent keywords and trending topics. Additionally, the application of co-word analysis through SciMAT and the Alluvial diagram allowed us to explore the themes of social network anonymization and scrutinize their evolution over time. These analyses culminated in an innovative taxonomy of the existing approaches and anticipation of potential trends in this domain. To the best of our knowledge, this is the first bibliometric analysis in the social network anonymization field, which offers a deeper understanding of the current state and an insightful roadmap for future research in this domain.Comment: 73 pages, 28 figure

    Lie symmetry and μ-symmetry methods for nonlinear generalized Camassa–Holm equation

    Get PDF
    Abstract In this paper, a Lie symmetry method is used for the nonlinear generalized Camassa–Holm equation and as a result reduction of the order and computing the conservation laws are presented. Furthermore, μ-symmetry and μ-conservation laws of the generalized Camassa–Holm equation are obtained

    Maximum Sauter Mean Diameter and Terminal Velocity of Drops in a Liquid-liquid Spray Extraction Column

    Get PDF
    The effect of holdup on Sauter mean drop diameter, d32 and the effect of d32 on terminal velocity have been investigated in a spray extraction column. There are two different zones for the dependence of d32 on holdup. d32 increased with an increase in holdup at low holdup levels and decreased with increasing holdup at high holdup levels. Variations in the terminal velocity of drops were similar to the dependence of d32 on holdup. Furthermore, empirical correlations have been derived to predict d32max and terminal velocity and were in a good agreement with the experimental data. The derived correlations were compared with other researchers work and the results were in a satisfactory conformity

    Geographical distribution of commercial bony fishes in Iranian waters of the Caspian Sea

    Get PDF
    The beach seines catch and effort data from 1996 to 2011 categorized in four periods and used in this research. Geographical coordinates of beach seines determined by portable GPS and distribution maps of important and commercial species prepared by catch per unit effort (CPUE). The concentration of beach seines in the western coast of Golestan province, Kiashahr area and eastern part of Anzali was more than another part. The daily effort in Kiashahr and Anzali area was very high, thus the fishing stress in these areas was more than another part of Iranian coastal waters of the Caspian Sea. The number of species in catch composition increased from east to west and the beach seines of Guilan province had total of commercial species, but the number of commercial species rarely was five species in Golestan province and especially in eastern coast. Relative frequency and distribution of Kuttum in the east Babolsar area and then between Sepidroud and Anzali lagoon were more than another part. The ISI index of Kuttum was high in all of the area except east coast of Golestan province. The main distribution of Mullets determined in the western coast of Golestan province and the Amirabad fishing area and in these areas, the ISI index of Mullets was high. The main distribution area of common carp determined in east coast of Golestan and the ISI index of common carp was very low in other parts. Density and distribution of Kolmeh were high in eastern and western coasts of Iranian waters of the Caspian Sea and the density of this species was very low in Mazandaran province. The density of Zander was very high in surrounding of Sepidroud River and Anzali lagoon. The ISI index of commercial species in Guilan province was more than other provinces except Kuttum, mullets and common carp

    Optimal Water Allocation from Subsurface Dams: A Risk-Based Optimization Approach

    Full text link
    Subsurface dams, strongly advocated in the 1992 United Nations Agenda-21, have been widely studied to increase groundwater storage capacity. However, an optimal allocation of augmented water with the construction of the subsurface dams to compensate for the water shortage during dry periods has not so far been investigated. This study, therefore, presents a risk-based simulation–optimization framework to determine optimal water allocation with subsurface dams, which minimizes the risk of water shortage in different climatic conditions. The developed framework was evaluated in Al-Aswad falaj, an ancient water supply system in which a gently sloping underground channel was dug to convey water from an aquifer via the gravity force to the surface for irrigation of downstream agricultural zones. The groundwater dynamics were modeled using MODFLOW UnStructured-Grid. The data of boreholes were used to generate a three-dimensional stratigraphic model, which was used to define materials and elevations of five-layer grid cells. The validated groundwater model was employed to assess the effects of the subsurface dam on the discharge of the falaj. A Conditional Value-at-Risk optimization model was also developed to minimize the risk of water shortage for the augmented discharge on downstream agricultural zones. Results show that discharge of the falaj is significantly augmented with a long-term average increase of 46.51%. Moreover, it was found that the developed framework decreases the water shortage percentage in 5% of the worst cases from 87%, 75%, and 32% to 53%, 32%, and 0% under the current and augmented discharge in dry, normal, and wet periods, respectively

    Hemoglobin Q-Iran detected in family members from Northern Iran: a case report

    Get PDF
    <p>Abstract</p> <p>Introduction</p> <p>Hemoglobin Q-Iran (α75Asp→His) is an important member of the hemoglobin Q family, molecularly characterized by the replacement of aspartic acid by histidine. The first report of hemoglobin Q-Iran and the nomenclature of this hemoglobinopathy dates back to 1970. Iran is known as a country with a high prevalence of α- and β-thalassemia and different types of hemoglobinopathy. Many of these variants are yet to be identified as the practice of molecular laboratory techniques is limited in this part of the world. Applying such molecular methods, we report the first hemoglobin Q-Iran cases in Northern Iran.</p> <p>Case presentation</p> <p>An unusual band was detected in an isoelectric focusing test and cellulose acetate electrophoresis of a sample from a 22-year-old Iranian man from Mazandaran Province. Capillary zone electrophoresis analysis identified this band as hemoglobin Q. A similar band was also detected in his mother's electrophoresis (38 years, Iranian ethnicity). The cases underwent molecular investigation and the presence of a hemoglobin Q-Iran mutation was confirmed by the amplification refractory mutation system polymerase chain reaction method. Direct conventional sequencing revealed a single guanine to cytosine missense mutation (c.226G > C; <it>G</it>AC ><it>C</it>AC) at codon 75 in the α-globin gene in both cases.</p> <p>Conclusion</p> <p>The wide spectrum and high frequency of nondeletional α-globin mutations in Mazandaran Province is remarkable and seem to differ considerably from what has been found in Mediterranean populations. This short communication reports the first cases of patients with hemoglobin Q found in that region.</p

    Tensile strength assay comparing the resistance between two different autologous platelet concentrates (leucocyte-platelet rich fibrin versus advanced-platelet rich fibrin): a pilot study

    Get PDF
    Background: Since the leucocyte-platelet rich fibrin (L-PRF) was published in 2001, many studies have been developed, analyzing its properties, and also verifying new possibilities to improve it. Thereby, it emerges the advanced-platelet rich fibrin (A-PRF) with a protocol that optimizes the properties obtained by the L-PRF. Nonetheless, there is a gap in the literature to landmark the evolutive process concerning the mechanical properties in specific the resistance to tensile strength which consequently may influence the time for membrane degradation. Thus, this study had the goal to compare the resistance to the traction of membranes produced with the original L-PRF and A-PRF protocols, being the first to this direct comparison. Findings: The harvest of blood from a healthy single person, with no history of anticoagulant usage. We performed the protocols described in the literature, within a total of 13 membranes produced for each protocol (n = 26). Afterward, the membranes were prepared and submitted to a traction test assessing the maximal and the average traction achieved for each membrane. The data were analyzed statistically using the unpaired t test. Regarding average traction, A-PRF obtained a value of 0.0288 N mm−2 and L-PRF 0.0192 N mm−2 (p < 0.05 using unpaired t test). For maximal traction, A-PRF obtained 0.0752 N mm−2 and L-PRF 0.0425 N mm−2 (p < 0.05 using unpaired t test). Conclusion: With this study, it was possible to conclude that indeed A-PRF has a significative higher maximal traction score and higher average traction compared to L-PRF, indicating that it had a higher resistance when two opposing forces are applied.info:eu-repo/semantics/publishedVersio
    corecore