Search for: water-solutions
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    Measurement of heat characteristics of a new incubator with a chemical energy source

    , Article International Journal of Engineering, Transactions A: Basics ; Volume 17, Issue 4 , 2004 , Pages 319-328 ; 17281431 (ISSN) Kakaee, A. H ; Farhanieh, B ; Khodadadeh, Y ; Sharif University of Technology
    National Research Center of Medical Sciences  2004
    A heat transfer model was developed for a new non-electric infant's transport incubator. The source of heat comprises a super saturated solution of Sodium Acetate and a metal disk (activator) in a plastic container. Estimating the number of the chemical bags required for different ambient temperature was the goal. First the quantity of heat generated by the chemical was appointed through experiments and use of a parameter estimation method. The number of the chemical bags were also estimated through a numerical-experimental method  

    Modeling and stability analysis of truncated high density lipoprotein (HDL) system using MARTINI coarse grain technique

    , Article ASME International Mechanical Engineering Congress and Exposition, Proceedings (IMECE) ; Volume 3 A , November , 2013 ; 9780791856215 (ISBN) Damirchi, B ; Rouhollahi, A ; Sohrabi, S ; Mehr, S. M. N ; Sharif University of Technology
    American Society of Mechanical Engineers (ASME)  2013
    Lipoproteins are biochemical compounds containing both proteins and lipids. These particles carry chemicals like cholesterol and triglycerides that are not soluble in aqueous solutions. This paper presents modeling of lipoprotein system using coarse grain molecular dynamics technique and stability analysis of this system in a water solution like blood. A high density lipoprotein (HDL) that consists of two annular monomers is modeled. Also there are lipid bilayers located in center of the rings, so the whole HDL and lipid bilayers are called lipoprotein system. First, all atom model is provided and then coarse-grain model is obtained using MARTINI technique. Modeling of the system in all atom... 

    Comparison of invasive and non-invasive cylindrical capacitive sensors for electrical measurements of different water solutions and mixtures

    , Article Sensors and Actuators, A: Physical ; Volume 167, Issue 2 , June , 2011 , Pages 359-366 ; 09244247 (ISSN) Behzadi, G ; Golnabi, H ; Sharif University of Technology
    In this study design and operation of invasive and non-invasive cylindrical capacitive sensor (CCS) designs for the electrical measurements of water, water solutions, and water mixtures are reported. Operation of the capacitance measurement module for such probes is based on the charge/discharge method. The measured capacitances and resistances for distilled water, mineral water, tap water and salt water samples are reported by using two sensor types and results are compared. The measured capacitance by invasive CCS for distilled water is about 2.28 μF and by non-invasive CCS is 31.40 pF, which shows a big difference for different probes. Such a difference is due to the electrical... 

    Model-based analysis for kinetic complexation study of Pizda and Cu(II)

    , Article Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy ; Volume 70, Issue 3 , August , 2008 , Pages 674-681 ; 13861425 (ISSN) Vosough, M ; Maeder, M ; Jalali Heravi, M ; Norman, S. E ; Sharif University of Technology
    In the present work, the multivariate kinetic complexation of a new synthesized ligand, 1-(2″-hydroxyl cyclohexyl)-3′-[aminopropyl]-4-[3′-aminopropyl]piperazine (Pizda) and Cu2+ in 50% ethanol-water solution is investigated using the UV-vis stopped-flow technique and state-of-the-art multi-wavelength numerical analysis. Model-based least squares fitting analysis or hard modeling is a specific part of chemometrics which is based on mathematical relationships for describing the measurements. Some recent developments include the incorporation of the effects of non-ideal experimental conditions into the fitting algorithm so it can substantially simplify experimental procedures. In this study no... 

    Investigating the effects of rock and fluid properties in Iranian carbonate matrix acidizing during pre-flush stage

    , Article Journal of Petroleum Science and Engineering ; Volume 166 , 2018 , Pages 121-130 ; 09204105 (ISSN) Karimi, M ; Shirazi, M. M ; Ayatollahi, S ; Sharif University of Technology
    Elsevier B.V  2018
    Acidizing of carbonate oil-wet rocks saturated with oil and saline formation water is subjected failure in some cases due to acid-induced damage such as sludge and emulsion formations. This condition may also lead to mineral precipitation, oil film barrier between acid and rock and diversion chemical malfunctions. Therefore, pre-flush process has been proposed as one of the most efficient stage for oil-wells matrix acidizing to reduce these challenges significantly. Besides, the pre-flush stage would result in more clean rock as the reservoir fluids are pushed back from the near wellbore regions, restoring rock wettability to more water wet state, preventing direct acid-oil contact and... 

    Poly(citric acid)-block-poly(ethylene glycol) copolymers-new biocompatible hybrid materials for nanomedicine

    , Article Nanomedicine: Nanotechnology, Biology, and Medicine ; Volume 6, Issue 4 , Aug , 2010 , Pages 556-562 ; 15499634 (ISSN) Tavakoli Naeini, A ; Adeli, M ; Vossoughi, M ; Sharif University of Technology
    Linear-dendritic ABA triblock copolymers containing poly(ethylene glycol) (PEG) as B block and hyperbranched poly(citric acid) (PCA) as A blocks were synthesized through polycondensation. The molecular self-assembly of synthesized PCA-PEG-PCA copolymers in water led to formation of nanoparticles and fibers in different sizes and shapes depending on the time and size of PCA blocks. Ten days after dissolving PCA-PEG-PCA copolymers in water, the size of fibers had reached several millimeters. Mixing a water solution of fluorescein as a small guest molecule and PCA-PEG-PCA copolymers led to the encapsulation of fluorescein by products of molecular self-assembly. To investigate their potential... 

    Semi-empirical modelling of hydraulic conductivity of clayey soils exposed to deionized and saline environments

    , Article Journal of Contaminant Hydrology ; Volume 249 , 2022 ; 01697722 (ISSN) Hedayati Azar, A ; Sadeghi, H ; Sharif University of Technology
    Elsevier B.V  2022
    Clay liners are widely used as porous membrane barriers to control solute transport and to prevent the leakage of leachate both in horizontal and vertical flow scenarios, such as the isolated base and ramps of sanitary landfills. Despite the primary importance of saturated hydraulic conductivity in a reliable simulation of fluid flow through clay barriers, there is no model to predict hydraulic conductivity of clayey soils permeated with saline aqueous solutions because most of the current models were developed for pure water. Therefore, the main motivation behind this study is to derive semi-empirical models for simulating the hydraulic conductivity of clayey soils in the presence of...