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مرکز اطلاعات علمی SID1
اسکوپوس
دانشگاه غیر انتفاعی مهر اروند
ریسرچگیت
strs
Author(s): 

AKBARI J. | SAEIDI M. | NORASTI Y.

Issue Info: 
  • Year: 

    2002
  • Volume: 

    -
  • Issue: 

    1
  • Pages: 

    13-20
Measures: 
  • Citations: 

    0
  • Views: 

    1226
  • Downloads: 

    132
Abstract: 

The physical chemists define an emulsion as a thennodynamicaly unstable mixtures of to essentially immiscible Liquids. Emulsions are sometimes difficult to prepare and require special processing techniques. The mixing of immiscible Liquids for various purposes has been met by the emulsification process for centuries. Synthetic and natural polymers have been used as auxiliary emulsifiers to improve the physical stability of medicinal emulsions. In this research the effects of hydrophilic Polymers like HPMC K4M, HPMC KIOOM, HPC, Traggacanth and Carbopol934P on stability of Liquid Paraffin emulsion, in 4, 25, and 40°C were evaluated. The fonnulationswere prepared based on two methods. The results, Showed that Carbopol have the best effect on emulsion stability in comparison with other polymers. These results proved that formulation method have effectiveness on stability too; for example in comparing of F31 with F38, which containing 150 mg of Carbopol 934P, changing in fonnulation method showed a significant difference in stabilizing activity of polymer (P<0.001).

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Issue Info: 
  • Year: 

    2019
  • Volume: 

    7
  • Issue: 

    2
  • Pages: 

    149-158
Measures: 
  • Citations: 

    0
  • Views: 

    46748
  • Downloads: 

    16883
Abstract: 

Liquid Paraffin can be used as a coolant fluid in electronic and cutting devices due to its suitable capabilities such as electrical insulating, high heat capacity, chemical, and thermal stability, and high boiling point. In this study, the dynamic viscosity of Paraffin containing the alumina nanoparticles has been examined experimentally. The nano􀏔 luids with different composition of alumina (0, 1, 2, and 3%) with the diameter of 20 nm were prepared by two‐ step method and tested by professional Brookfield rheometer in the temperature range of 20 oC to 60 oC and the shear rates of 12 s‐ 1 up to 200 s‐ 1. Experimental results indicated that the nano‐ lubricant behaves as Newtonian 􀏔 luid in the volume fraction of 0 and 1% only at the temperatures of 50 and 60 oC. While it behaves as non‐ Newtonian 􀏔 luid in the volume fraction of 2 and 3% for all measured temperatures. The results showed that the power law model represents the best curve fitting of the experimental data. Therefore, the coefficient values of power‐ law model including, consistency index and flow index were reported. Finally, an equation of relative viscosity based on the volume fraction and temperature of the combination was proposed by applying the curve fit technique on the experimental data.

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Issue Info: 
  • Year: 

    2020
  • Volume: 

    6
  • Issue: 

    3
  • Pages: 

    213-222
Measures: 
  • Citations: 

    0
  • Views: 

    38054
  • Downloads: 

    20760
Abstract: 

Background: The study aimed to evaluate the effect of arachis oil and Liquid Paraffin on metoclopramide release from transdermal films. Objectives: Batches of metoclopramide films were prepared with hydroxypropyl methyl cellulose (HPMC), arachis oil or Liquid Paraffin and Tween 80 as plasticizer. The films were evaluated for their physiochemical properties, in vitro and ex vivo drug release and drug release kinetics. Drug-excipient interactions were investigated using Differential Scanning Calorimetry (DSC) and Fourier Transform Infrared (FTIR) spectroscopy. Methods: The transdermal films had a weight range of 0. 22-0. 24 g, folding endurance of 300-306, percentage moisture content and uptake of 2%-10% and 19%-110%, respectively and drug content of 98%-104%. There was similar condition in vitro release profile for the films but their ex vivo profiles exhibited variable drug release with the P3 (30% arachis oil) giving the highest drug (almost 100%) release. Results: The release kinetics of metoclopramide followed the first order and Korsemeyer-Peppas models more closely as seen in their correlation coefficients (R2) of 0. 9832 and 0. 9560, respectively. Drug-excipient compatibility studies showed no interactions between excipients and metoclopramide. Conclusion: The formulated transdermal films showed controlled drug release over a period of 12 h. Arachis oil and Liquid Paraffin showed similar permeation enhancing ability. These enhanced permeation properties of the films could be helpful in the development of alternative route for metoclopramide administration in the management of emesis with improved patient acceptance.

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گارگاه ها آموزشی
Author(s): 

FARAHMAND F.

Journal: 

ACTA MEDICA IRANICA

Issue Info: 
  • Year: 

    2007
  • Volume: 

    45
  • Issue: 

    3
  • Pages: 

    183-188
Measures: 
  • Citations: 

    0
  • Views: 

    98038
  • Downloads: 

    44618
Abstract: 

Liquid Paraffin has been suggested as a good laxative comparing to lactulose as a treatment option in pediatric constipation. This study was performed to compare Liquid Paraffin with lactulose in pediatric constipation. A total of 247 patients (127 males and 120 females) aged 2-12 years (mean 4.1±2.7 years) with chronic functional constipation were included in an 8 week, randomized, controlled trial.After faecal disimpaction, patients received oral Liquid Paraffin (1-2 cc/kg/day) or lactulose (1-2 cc/kg/day). Primary outcome measures were: defecation and encopresis frequency per week and successful treatment after 8 weeks. Success was defined as a defecation frequency 4 3 per week and encopresis 6 1 every two weeks. Secondary outcome measures were side effects during 8 weeks of treatment. A significant increase in defecation frequency, Liquid Paraffin group, 3 pre, versus, 12 post treatment per week and lactulose group: 3 pre, versus 8 post, per week was found. A significant decrease in encopresis frequency, Liquid Paraffin: 10 pre, versus 1 post per week; lactulose: 9 pre, versus 3 post per week, was found in both groups. However success was significantly higher in the Liquid Paraffin group (85%) compared with the lactulose group (29%). Liquid Paraffin patients reported less abdominal pain, straining and pain at defecation than children using lactulose. Liquid Paraffin is more effective than lactulose in the treatment of chronic functional constipation of childhood. It provided a higher success rate with fewer side effects. Liquid Paraffin should be the laxative of first choice in childhood functional constipation.

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Issue Info: 
  • Year: 

    2011
  • Volume: 

    19
  • Issue: 

    2
  • Pages: 

    154-158
Measures: 
  • Citations: 

    0
  • Views: 

    100123
  • Downloads: 

    27086
Abstract: 

Background and the purpose of the study: Functional constipation is prevalent in children. Recently polyethylene glycol has been introduced as an effective and safe drug to treat chronic constipation. There are only a few clinical trials on comparison of PEG and Liquid Paraffin in childhood constipation. The purpose of this study was to evaluate clinical efficacy and safety of PEG 3350 solution and Liquid Paraffin in the treatment of children with functional constipation in Sari Toba clinic during the period of 2008-2009.Methods: Children with a history of functional constipation were subjects of this study. One hundred and sixty children of 2-12 years old with functional constipation were randomized in two PEG and Paraffin treatment groups. Patients received either 1.0-1.5 g/kg/day PEG 3350 or 1.0-1.5 ml/kg/day Liquid Paraffin for 4 months. Clinical efficacy was evaluated by stool and encopresis frequency/week and overall treatment success rate was compared in two groups.Results and major conclusion: Compared with the baseline, defecation frequency/ week increased significantly and encopresis frequency meaningfully decreased in two groups during the period of the study. Patients using PEG 3350 had more success rate (mean: 95.3%±3.7) compared with the patients in Paraffin group (mean: 87.2%±7.1) (p=0.087). Administration of PEG 3350 were associated with less adverse events than Liquid Paraffin. In conclusion in treatment of pediatric functional constipation, regarding clinical efficacy and safety, PEG 3350 were at least as effective as Liquid Paraffin and but less adverse drug events.

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Issue Info: 
  • Year: 

    2022
  • Volume: 

    31
  • Issue: 

    9
  • Pages: 

    1047-1056
Measures: 
  • Citations: 

    0
  • Views: 

    0
  • Downloads: 

    4360
Abstract: 

The microporous structure of ultra-high-molecular-weight polyethylene (UHMWPE) separator is originated from the solid–, Liquid (S–, L) phase separation in the UHMWPE/Liquid Paraffin (LP) blend. To understand the pore-forming mechanism, in this study, we have explored the dynamics of S–, L phase separation in the UHMWPE/LP blends with different compositions by DSC analysis. The phase separation temperature region of 104–, 120 °, C is divided into six temperature points for obtaining isothermal crystallization curves. Then, the data are analyzed using Avrami equation and Arrhenius equation, as a result, the activation energy at high temperature region is reached 732. 3–, 569. 4 kJ mol−, 1, higher than 118. 1–, 149. 9 kJ mol−, 1 at low temperature range. It means that initial phase separation could be more difficult for less effective nucleation at high temperature. In addition, the value of "n" also drops down with increasing the UHMWPE content in the blends, which is consistent with two-dimensional silk-like and one-dimensional needle-like morphology in the case of 30% UHMWPE content. Low content of UHMWPE segments has a weaker nucleating ability, which is favorable for the crystal growth in the UHMWPE/LP blends and generating loose porous structure. It is also inspiring for the production of separator to regulate the pore structure in the phase separation.

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strs
Author(s): 

TABATABAEE MITRASADAT

Issue Info: 
  • Year: 

    2016
  • Volume: 

    6
  • Issue: 

    24
  • Pages: 

    73-79
Measures: 
  • Citations: 

    0
  • Views: 

    602
  • Downloads: 

    339
Abstract: 

Aim and Background: Complex structures of asphaltene and Paraffin wax are two troublesome components in processing of heavy oils. Nowadays physicochemical processes are used as a resolution for this problem which are both financial and human resource consuming. Exploiting biological methods could open new horizon to solve these problems..Materials and Method: In this study after sampling from different Lavan’s production wells, initial treatment with Paraffin was done. Then screening, enrichment and isolation were done consequently. Biosurfactant production was also investigated. The next step was studying the growth curve of the bacteria that were able to use Paraffin as the sole source of carbon and energy and their physiochemical endurance was monitored. After bacterial treatment, Paraffin was extracted by n-hexane and was analyzed chemically by gas chromatograph FID. Finally the selected bacterium was identified molecularly.Results: GC chromatograms suggested a considerable decrease in amount of Paraffinic components through the treatment by an indigenous thermophlic, biosurfactant producing bacterium, known as Bacillus thermoleovoran s molecularly. This bacterium could grow in temperature rate from 40°C to 65°C, pH from 4 to 10 and salinity from 0.5 to 15%.Conclusion: A few studies on Paraffin degradation in high temperature have been done in Iran. Bacillus thermoleovorans is an Iranian crude oil indigenous thermophilic bacterium with high physicochemical endurance which could be a proper choice environmental of petroleum industry application.

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Issue Info: 
  • Year: 

    2019
  • Volume: 

    6
  • Issue: 

    2
  • Pages: 

    85-93
Measures: 
  • Citations: 

    0
  • Views: 

    70577
  • Downloads: 

    14659
Abstract: 

Liquid Paraffin as a coolant fluid can be applied in electronic devices as a result to its suitable capabilities such as electrical insulating, high heat capacity, chemical and thermal stability, and high boiling point. However, the poor thermal conductivity of Paraffin has been confined its thermal cooling application. Addition of high conductor nanoparticles to Paraffin can fix this drawback properly. In this article, the influence of the nanoparticles on the thermal conductivity of base material was assessed. Temperature (20-50° C) and volume fractions (0-3%) effect on the thermal conductivity of Paraffin/alumina nanofluids have been considered. Nanofluid samples were prepared applying the two-step method. The thermal conductivity was measured by a KD2 pro instrument. The results indicated the thermal conductivity augments smoothly with an increase in volume fraction of nanoparticles as well as temperature. Moreover, it observed that for nanofluids with more volume-fraction the temperature affection is more remarkable. Thermal conductivity enhancement (TCE) and effective thermal conductivity (ETC) of the nanofluid was calculated and new correlations were reported to predict the values of them based on the volume fraction of nanoparticles and temperature of nanofluid accurately.

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Issue Info: 
  • Year: 

    2021
  • Volume: 

    19
  • Issue: 

    113
  • Pages: 

    6-17
Measures: 
  • Citations: 

    0
  • Views: 

    217
  • Downloads: 

    165
Abstract: 

Olefin-Paraffin separation with equivalent carbon number is an important cost-effective step in olefin production in petrochemical industries. Liquid membrane technology using ionic solutions can perform olefin-Paraffin separation in a selective manner. In this paper, the separation of light olefin-Paraffin mixtures using supported Liquid membrane is modeled in an unsteady-state manner. In this model, mass transfer is considered in the direction of membrane thickness and the effect of feed pressure, silver concentration, solvent type and time on flux rate was investigated. For model evaluation, experimental data of ethylene-ethane separation with aqueous solution of silver nitrate and propylene-propane separation with aqueous solution of silver nitrate, AgNO3-NMP and AgBF4-BMImBF4 were used. There is a good agreement between experimental and modeling data (with 12. 2% difference). Moreover, it was concluded that by using viscose or ionic Liquids, which are substituted for water (solvent) in order to solve evaporation problems, cause a decrease in flux and product selectivity.

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Issue Info: 
  • Year: 

    2007
  • Volume: 

    9
  • Issue: 

    2 (22)
  • Pages: 

    12-16
Measures: 
  • Citations: 

    0
  • Views: 

    48909
  • Downloads: 

    610
Abstract: 

Background & Objective: The papanicolaou (pap) smear has been used to screen women for cervical cancer since 1940. Unsatisfactory results induce anxiety in patients and doctors. Recently, a number of new technologies have been developed to improve the detection of cervical cancer. Increase the early detection of meaningful pap smear abnormalities, reduce the number of unsatisfactory smears and false negative results and provide fewer ambiguous results one of these method is the new test, include Liquid-based to improve the quality and quantity of the cervical pap smear. The aim of this study is to evaluate rate of unsatisfactory smear of cervical cytology in two methods, conventional pap smear (CP) and Liquid-Based (L.B).Materials & Methods: A comparison cross – sectional study was performed from 2004-2005 on 1500 patients referred to the Ghaem hospital and private clinic. From all patients cervical cytology was taken randomly via two methods CP and L.B. Subsequently frequency unsatisfactory cervical cytology in tow methods evaluated. Statistical analysis using the SPSS soft ware was done and t-test and c2 used for comparative evaluation.Results: Considering the incidence of unsatisfactory cervical cytology in CP method %0.3 was and in LB method %1 was. Sensitivity of the C.P method was 68.8% and that of the L.B method was 83.1%.Conclusion: In this study incidence unsatisfactory rate in L.B method was higher than C.P method.

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