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Showing 164 results for Film


Volume 0, Issue 0 (8-2024)
Abstract

Aluminum nano-films are one of the functional elements that have various applications in different fields such as strengthening cement base materials, improving the performance and efficiency of concrete, and enhancing the mechanical and volumetric properties of clay. In this study, the mechanical responses of aluminum nano-film are investigated under uniaxial tensile and compressive tests using the molecular dynamics (MD) method. The initial configuration of the nano-film is constructed based on a 3D aluminum core—alumina shell model that provides a suitable description of surface oxidation in the nano-film. This model is useful to determine the influence of surface oxidation on the mechanical behavior of nan-film. Because of the accuracy and competency, the inter-atomic interactions are evaluated using the EAM+CTI potential, which is a hybrid potential consisting of two components, i.e., EAM and CTI potential, such that it can also take into account the electrostatic interactions between the atoms. After establishing the initial configuration, the energy minimization process is performed on the nano-film, and then its temperature and pressure are adapted to the environmental conditions through the relaxation process. The MD analysis is accomplished by the open-source LAMMPS software, and the visualization of outputs is performed by the open-source OVITO software. The periodic boundary condition is imposed on the lateral sides of the nano-film to eliminate the free surface effect of the atomistic analysis. The tensile and compressive tests are applied to the nano-film in accordance with the experimental tests, and the stress—strain curves are determined. The concept of Virial stress is employed to calculate the stress of the atomic model, which is equivalent to the conventional Cauchy stress in classical mechanics. In order to diminish the dynamic effects, deformation is incrementally applied to the nano-film, such that at each increment, a small strain is gently imposed, then the nano-film is relaxed under the deformed conditions, and finally the stress and strains are evaluated. The numerical simulations are verified by comparing them with experimental data, which demonstrates the acceptable accuracy of the obtained numerical results. The influence of various parameters such as the thickness and the percentages of oxide layers are investigated on the mechanical response and stress-strain curve of aluminum nano-film under the uniaxial tests. It is demonstrated that the thickness of the oxide layer significantly impacts the mechanical behavior, such that the hardness and energy absorption capacity of the nano-film is increased considerably by increasing the percentage of the oxide layer thickness. However, increasing the total thickness of the nano-film leads to a decrease in the Young’s modulus and elastic limit of the specimen. It is because of the decrease in the percentage of oxide layer thickness by increasing the total thickness of the nano-film. Point defects are one of the important imperfections in the crystal structures of atomic configuration that have a significant effect on the mechanical behavior of materials. In order to investigate the influence of point defects, different percentages of voids are generated by randomly omitting some atoms in the nano-film domain. The generated specimens are analyzed under the uniaxial tests, and their mechanical characteristics are evaluated. The numerical simulations demonstrate that the hardness of the nano-film is significantly reduced by increasing the point defects.
 

Volume 1, Issue 3 (9-2023)
Abstract

In this study, we investigated the effectiveness of both single and hybrid systems, incorporating UV photolysis and a Moving Bed Biofilm Reactor (MBBR), for treating synthetic wastewater contaminated with petroleum hydrocarbons. Petroleum hydrocarbons pose significant environmental threats due to their high toxicity, stability, accumulation potential, and resistance to biodegradation. In the hybrid system, the wastewater underwent chemical treatment first and then was introduced into the biological reactor. For the photolysis system, we explored the impacts of different concentrations and various radiation powers of UV-C lamps. Optimal conditions were determined to be a Chemical Oxygen Demand (COD) of 350 mg/L and a radiation power of 80 W. In the MBBR system, various concentrations were introduced into the reactor, achieving a maximum removal efficiency of 85% for an initial COD of 1000 mg/L over 72 hours with a 50% filling capacity. In the hybrid system, we achieved a remarkable hydrocarbon removal efficiency of 99% after 123 hours. Although the operational time of the hybrid system was relatively long, it demonstrated itself as a suitable treatment process compared to other conventional methods for removing these challenging, hard-to-biodegrade compounds.

Volume 2, Issue 2 (4-2016)
Abstract

Background: Pseudomonas aeruginosa is considered an opportunistic pathogen; several reports indicate that the organism can also cause infections in healthy hosts. Four effector proteins have been described in P. aeruginosa: exoU, exoS, exoT, and exoY. These genes that are translated into protein products related to type III secretion systems. Materials and Methods: A total of 134 samples were isolated, and P. aeruginosa was identified using biochemical tests. Bacterial genomic DNA was extracted, and the presence of the exoSand exoUgenes were detected by PCR. Biofilms were formed by culturing P. aeruginosaon glass slides in rich medium. Results: The exoU(73%), exoS (62%) genes were detected from infections caused by P. aeruginosa in urinary tract infection patients. Among the 119 strains isolated from patients with urinary tract infections. Conclusion: An improved understanding of virulence genes and biofilm formation in P.aeruginosa may facilitate the future development of novel vaccines and drug treatments.

Volume 2, Issue 2 (9-2018)
Abstract

In this study, the effects of drying temperature and mechanical pressure on the surface structure and dynamical properties of polyaniline (PAni) were studied. PAni was synthesized through the aniline polymerization process in the presence of ammonium persulfate in acidic medium and normal methyl-2-pyrrolidine solution. The obtained solution was dipped on a substrate of quartz glass. Atomic force microscopy (AFM) analysis based on nano-indentation tests were used to determine the values of hardness, Young’s modulus and Poisson’s ratio of the films. The results of the analysis of the scanning electron microscope demonstrated that the surface morphology of the film is changed from a fiber-to-interconnected cross-linked networkby increasing the drying temperature. The transmission electron microscope analysis showed that the diameter of the fibers on the surfaces dried at 318 K and 418 K was 18 and 30 nm, respectively. AFM results showed that the mean surface roughness of PAni film at 318 K without mechanical pressure was 63 nm, while for the film pressed at 5 MPa was less than 35 nm. Thermo-mechanical analysis showed that the glass transition temperature of the PAni film prepared without mechanical pressure and the film pressed at 5 MPa were 386 K and 378 K, respectively. Investigating the temperature dependence and applied pressure on the film surface in determining the viscoelastic properties of the PAni nanostructured film can provide readers with appropriate information about the storage and loss modulus of the film and the activation energy of the polymer layer during the thermal decomposition process.



Volume 2, Issue 3 (2-2019)
Abstract

Molecular imprinting is a novel technique for preparing specific absorbents with selective sites for binding to the target molecule. Molecularly imprinted polymers, because of their high selectivity and stability, low cost and easy methods of preparation, have been widely employed in separation procedures. In this study, we evaluated the synthesized electrospun imprinted membrane (MIM) as a specific sorbent for herbicide mecoprop (MCPP). The films were prepared using methacrylic acid (MAA) as functional monomer and polyethylene terephthalate (PET) as a main part of polymeric solution and in the presence of dichloromethane (DCM) and Trifluoroacetic acid (TFA) as the solvents. The template was extracted through washing, results in the free specific memory sites within the films. Then, the synthesized electrospun imprinted membrane (MIM) was evaluated as a specific sorbent for herbicide mecoprop (MCPP). The results showed that the solution with 20% w/v of PET was the optimal solution for electrospinning process and at all different MCPP/MAA molar ratios (1:2, 1:4. 1:6 and 1:8), MIM had higher removal ability for template molecule (p<0.05) compared to NIM. The template/monomer ratio of 1:4 had the best binding amount. We also investigated the capability of MIM to be used as sorbent for pesticide 2,4-D, that is, the analogue of the main template molecule and diazinon, that is, the pesticide with different structure to the template. In addition, we used synthesized MIM and NIM films to extract MCPP analyte from environmental aqueous samples (bottled water and groundwater) and the results indicated successful performance of MIM compared to NIN.


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Volume 3, Issue 2 (9-2014)
Abstract

Edible films and coatings are a thin layer of material that used on the surface and between different layers of nutrients. Biopolymers such as polysaccharides, proteins, lipids and their mixtures are used for the preparation of the edible films and coatings. Due to consumers demand for access to high quality materials and their concern because of the problems caused by the use of artificial preservatives, as well as environmental concerns arising from the accumulation of synthetic polymers, the idea of using biodegradable biopolymers as a replacement for the plastic packaging was strong. Efficiency and functional properties of edible films and coatings is dependent on intrinsic properties of ingredients of films, namely, biopolymers, plasticizer and other additives. The useful properties of edible films and coatings are capability of eating and biodegradation of them. Some properties of edible film sand coatings, such as preventing moisture transport and volatiles out of food, selective throughput oxygen and carbon dioxide, delaying surface dehydration, tissue changes, barrier against fat sand oils transports, increase nutritional value, preventing dripping, microbial growth and rancidity, Maintaining the quality of Aquatic and their products against physical damage caused by their transportation, increase the shelf life of them. For industrial use, more scientific studies are needed to determine the mechanisms of the film formation from biopolymers for optimizing their properties. Biodegradable compounds used in this study for aquatic coating and their effects on maintaining the quality of fish and their action mechanism has been investigated.

Volume 3, Issue 4 (12-2017)
Abstract

Background: Emergence of drug-resistant bacteria has highlighted the need to identify new and more efficient antibacterial agents. The aims of this study were to evaluate the antibacterial activity of dill (Anethum graveolens) seeds essential oil and to investigate the effect of cumin (Cuminum cyminum) seeds alcoholic extract on biofilm formation ability of Klebsiella pneumoniae.
Materials and methods: This experimental study was carried out at the Faculty of Medicine of Kurdistan University of Medical Sciences in 2014. Activity of dill seeds essential oil was evaluated based on the inhibition zone diameter and minimum inhibitory concentration (MIC) against some important pathogenic bacteria including: Vibrio cholerae, Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus. Furthermore, the effect of sub-inhibitory concentrations of cumin seeds alcoholic extract was evaluated on biofilm formation ability of K. pneumoniae. The biofilms were formed on semi-glass lamellas and observed by a scanning electron microscope.
Results: Dill essential oil showed a good to moderate activity against the tested strains. The highest antibacterial activity was observed against S. aureus (inhibition zone of 15 mm and MIC of 0.62 mg.mL-1) and V. cholerae (inhibition zone of 14 mm and MIC of 0.7 mg..mL-1). The cumin alcoholic extract had no effect on biofilm formation ability of K. pneumoniae.
Conclusion: The results of this study showed the presence of antimicrobial compounds in dill extract. The cumin alcoholic extract was not able to inhibit biofilm formation ability of K. pneumoniae. Because of the medicinal plants properties, it is valuable to search for promising herbs and novel chemical compounds.

Volume 3, Issue 4 (12-2018)
Abstract

Aims: Low Back Pain (LBP) is one of the most prevalent and costly health problems world wide.this protocol study aims to develop and evaluate an interactive video film intervention in order to reduce LBP.
Instruments & Methods: In this randomized controlled trial study 80 referees to health centers affiliated to Shahid Beheshti University of Medical Sciences (SHBUMS) will be selected according to inclusion/exclusion criteria and divided into two groups of intervention
and control. The video film will be just shown for intervention group. Data will be collected through a self-designed questionnaire regarding Physical Activity (PA) behavior, Visual Analogue Scale (VAS) for measuring pain severity, Rowland Maurice’s Questionnaire (RMQ) for assessing disability and Hospital Anxiety and Depression Inventory (HADS) for anxiety and depression measurement. Date will be measured at two times of pre and post intervention in both groups and analyzed through descriptive and statistical tests.

Conclusions: The study may provide a fairly less expensive, assessable, and powerful alternative intervention for individuals suffering from LBP and related disability.


Volume 4, Issue 2 (7-2018)
Abstract

Aims: Streptococcus mutans (S. mutans) is part of human oral cavity microbiome and is known to be responsible of dental caries. The aim of this study was to evaluate the inhibitory effects of Punica granatum, Ricinus communis, and Allium sativum extracts on biofilm formation caused by S. mutans.
Materials and Methods: In this experimental study, the biofilm formation was carried out by broth dilution method with glucose -supplemented Tryptic Soy Agar (TSB) in 96-well microtiter plates. Seven serial dilutions from the aqueous extracts of the Punica granatum, Ricinus communis, and Allium sativum were prepared. Then, a suspension of S. mutans was added to the wells. The anti-biofilm effects of the extracts and turbidity were measured by an ELISA reader apparatus at OD492nm. Experiments were completed in triplicate.
Findings: Ricinus communis was more active on S. mutans than other extracts. In comparison with others, the mean OD obtained in the presence of a concentration of 50mg of the plant extract (OD=0.083) was close to the negative control (OD=0.068). This plant was effective in higher concentrations (50, 25, 12.5 and 6.25mg/ml). Allium sativum extract has a moderate effect on S. mutans. The lowest activity belonged to Punica granatum extract.
Conclusion: The extract of Ricinus communis has strong anti-biofilm activity against Streptococcus mutans, when compared to other extracts, Allium sativum extract show moderate activity on the biofilm formation. Aqueous extract of Punica granatum peel isn’t very effective on S. mutans.
Akbar Vejdan, , Afshin Adeli, Mehdi Abdollahi,
Volume 4, Issue 3 (12-2015)
Abstract

In this study an agar/gelatin bilayer film was produced from agar and gelatin monolayers using the casting method in two phases. Then, the characteristics of this bilayer film, including water vapor permeability (WVP), water solubility, water absorption, mechanical and optical properties were compared with those of monolayer films. The results showed that  WVP of the bilayer film (3.25×10-10 g/msPa)  was significantly lower than the agar (3.90 × 10-10 g/msPa), and gelatin (4/32×10-10 g/msPa). Absorption of UV light by bilayer film was significantly higher than the single-layer agar and gelatin films. Although the tensile strength of the bilayer film (10.8 MPa) was higher than the single-layer gelatin (2.86 MPa), it was lower than the single layer of agar film (30.49 MPa) (P<0.05). In conclusion, some properties of agar and gelatin films can be improved by making bilayers film of both biopolymers. 
Mohsen Kazemi, Bahareh Shabanpour, Parastoo Pourashouri,
Volume 4, Issue 3 (12-2015)
Abstract

In order to improve the properties of myofibrillar protein-based film from silver carp (Hypophthalmichthys molitrix), nanofibrillated cellulose (NFC) at 3 levels (1, 3 and 5%) was used. Optimum treatment was determined by evaluating the mechanical, physical and optical properties as well as scanning electron microscopy analysis (SEM). Cellulose nanoparticles had no effect on tensile strength but reduced the elasticity of film (p≤0.05). Water vapor barrier property (WVP) and other physical properties of the films were improved by addition of nanofibrillated cellulose at 1%, but decreased at higher concentrations (p≤0.05. Based on SEM, low concentrations of nanoparticles showed more homogeneous dispersion and films had a smoother and better cross-sectional area compared to the higher levels of nanoparticles. Generally, low levels of nanoparticles could be effective to improve the mechanical and physical properties of myofibrillar protein - nanofibrillated cellulose films.  

Volume 4, Issue 4 (9-2018)
Abstract

Aims:  Uropathogenic Escherichia coli (UPEC) is one of the most important causative agents of urinary tract infection (UTI). UPEC isolates persist in the body through biofilm formation. The successful adhesion is the most important step of biofilm formation. Type 1 and P are bacterial surface appendices, which play a pivotal role in of UPEC. The aim of this study was to assess the effect of on the initial adhesion gene expression in UPEC isolates.
Materials & Methods: The presence of and genes among 60 UPEC isolates was investigated by PCR; 5 potent producer UPEC strains from patients with UTI were exposed to the sub-minimum inhibitory concentration of Expression of the and genes was evaluated by real-time PCR.
Findings: Of the 60 UPEC isolates, biofilm formation was seen in 27 (45%) of isolates, 5 of which produced strong The result of PCR assay showed that was seen in 57 (95%) of the 60 UPEC isolates and was seen in 58 (96.6%) of isolates, respectively. and expression 7 and 8 fold in all 5 isolates, respectively.
Conclusion: Sub-MIC concentrations of remarkably decreased the expression the and genes in strong forming UPEC strains, but cannot prevent biofilm formation.

Seyede Marzieh Kazemi, ,
Volume 5, Issue 2 (9-2016)
Abstract

The antimicrobial and physico-mechanical properties of fish gelatin-alginate film incorporated with oregano (Origanum vulgare L.) essential oil (OEO) were assessed. The blended films were prepared with 75% fish gelatin and 25% sodium alginate and OEO (0, 0.5, 1.0, 1.5%) was added to the film solutions. Results showed that adding 0.5% OEO into films improved tensile strength about 2.54 MPa compared to the control films. The incorporation of 1.5% essential oil decreased tensile strength and the elongation percentage by 3.16 MPa and 15.59%, respectively; water vapor permeability, viscosity and opacity also significantly declined (P < 0.05). Scanning electron microscopy (SEM) of the surface of the film confirmed these results. Although 1.5% OEO-films showed higher antimicrobial activity, fish gelatin-alginate films incorporated with lower level of OEO can be can be more appropriate for food preservationl.

Volume 5, Issue 17 (7-2008)
Abstract

  The use of edible films to release antimicrobial constituents in food packaging is a form of active packaging. There are many studies about antimicrobial properties of spice extracts; however their application to edible films is limited. In this study chitosan-based edible films containing thyme and clove essential oils were prepared at 0.5, 1 and 1.5 percent v/v. Antibacterial properties of edible films were tested against five strains of Gram-positive and Gram-negative bacteria. Physical and mechanical properties of films including humidity content, water vapor permeability, tensile strength and elongation at break were measured. Films containing thyme essential oil showed larger inhibitory zones (p<0.05) compared to those of containing clove essential oil. Films were more effective against Gram-positive bacteria than Gram-negative ones. Incorporation of essential oils increased water vapor permeability of chitosan-based films. Incorporation of essential oils decreased tensile strength of films. Films containing thyme essential oil showed larger reduction in tensile strength property compared to those of containing clove essential oil.

Volume 6, Issue 4 (12-2018)
Abstract

The article investigates the adaptive method of Hayao Miyazaki in using Japanese narratives through his animation filmmaking based on James Dudley Andrew’s theory. Qualitative research method has been applied owing to the nature of the content and the type of analysis. In line with the research aim, the main question is how Miyazaki has adopted Japanese narrative literature in making his animated films (the case). Miyazaki’s admired animated movies were adopted from Japanese narratives. Accordingly, among which Spirited Away was analyzed as the case of the study. The results consist of fundamental points revealing his method of adaptation. Miyazaki has considered the full capacity of Japanese narrative literature and other adaptative approaches in developing drama, characterization, visual and audio elements of his films perfectly. Bringing up the ideas in this way, Miyazaki has created the main elements of narrative aligned with his cinematic expression. Not only did he adapt the texts of Japanese literature, but also benefited from the illustrations of the literary works. Miyazaki's style uncovers the various potentials of narrative sources for idea generation in storytelling, characterization as well as it reveals how to create successfully hit animated feature films. His method can be an effective strategy in making superior and adaptation Iranian filmmakers may consider in animation film production.



Volume 6, Issue 20 (4-2009)
Abstract

  Due to the environmental hazards of using plastic films, studies on the development of plant based films such as soy protein films, are receiving more attention.  In this research, edible films were prepared from soy protein isolate and the effect of glycerol as a plasticizer at three concentration levels of 0.4, 0.6 and 0.8 g/g of soy protein isolate on the properties of these films was investigated. Some Mechanical properties, i.e. tensile strength and extension, and physical properties, i.e. water vapor transmission rate, opacity, water adsorption and solubility were examined. Films prepared without glycerol were very brittle and could not be examined. Results showed that increasing the concentration of glycerol led to a significant (p<0.05) increase in extension rate and decrease in tensile strength of soy protein isolate films. Solubility percentage, water adsorption and water vapor transmission rate of the films were found to increase when the glycerol level increased.  Although glycerol addition reduced the opacity of the films, its concentration did not have a significant correlation with this parameter (p<0.05).

Volume 6, Issue 21 (7-2009)
Abstract

The objectives of this study were to investigate the potential of faba bean protein isolate (FPI) in preparation of an edible film and to determine the effects of film forming solution pH and plasticizer concentration on film properties. So film samples were prepared in three different pH levels (7, 9 and 12) and plasticizer concentrations (40, 50 & 60% w/w protein isolate). Results showed that increasing of pH improved mechanical properties (tensile strength and elongation) and solubility of films but caused water vapor permeability (WVP) and lightness of films to decrease. Plasticizer concentration did not affect WVP over the studied range. Elongation and solubility of films increased and tensile strength decreased by increasing of plasticizer content of film forming solutions. The lowest WVP and the highest tensile strength was observed at pH 12 and 40% (w/w of FPI ) glycerol concentration.

Volume 6, Issue 21 (7-2009)
Abstract

Fruit juices are among heat sensitive foods. Vitamins, proteins and other organic materials present in most fruit juices may be easily decomposed during heat processing. Therefore, evaporators with minimum residence time and maximum efficiency for concentrating fruit juices should be applied. So,tubular type falling and climbing film evaporators are suitable devices. In the present investigation, certain important factors in concentration of in digenous orange juice from north region of Iran in a pilot-plant double effect falling-climbing film evaporator have been studied. Variation of liquid film tickness, heat transfer coefficient, hydrodynamic and thermal properties show that evaporation of the fruit juices take places in turbulent regime and required concentration and ratio of the product concentration to acidity can be achieved by six stages evaporation.

Volume 7, Issue 1 (1-2021)
Abstract

Background: Staphylococcus epidermidis isolates are among the most important causes of nosocomial infections and could be classified as health threatening agents. This study aimed to determine the biofilm formation ability and clonal dissemination of S. epidermidis strains isolated from patients and healthy people in Isfahan during 2016 and 2017.
Materials & Methods: A total of 139 and 123 suspected colonies of S. epidermidis were collected from different clinical specimens and the arm of healthy people, respectively. The ability to form biofilm was determined using a combination of Congo-red agar (CRA) and microtiter plate (MTP) assays. The presence of genes involved in biofilm formation was also tested by the polymerase chain reaction (PCR) test. The susceptibility of all strains to 12 antibiotics was evaluated using the disk diffusion method according to the Clinical & Laboratory Standards Institute (CLSI) guidelines. Moreover, all biofilm-producing strains were typed using PhenePlate system as well as cassette chromosome mec (SCCmec) and accessory gene regulator (agr) locus typing method.
Findings: A total of 43 biofilm-producing S. epidermidis strains were identified among 107 and 123 confirmed strains isolated from hospitalized patients and healthy people, respectively; all of which were positive for aap gene, and the presence of ica operon was limited to 86 and 27% of the strains isolated from patients and healthy people, respectively. All the strains showed susceptibility to vancomycin, quinupristin-dalfopristin, and linezolid. Moreover, SCCmec Types III, IV, and V were detected among all methicillin-resistant S. epidermidis (MRSE) strains, and agr Type I was the most frequent one. Among all biofilm-positive strains, 3 common types (CTs) and 7 single types (STs) were determined;  CT1 and CT2 were the most common types among the strains isolated from hospitalized patients and healthy people.
Conclusion: These findings indicated the presence and persistence of diverse clone types of biofilm-producing S. epidermidis strains with common types of PhP, agr, and SCCmec in the hospital and the community of Isfahan.

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