112 research outputs found

    Study of nonlinear dynamics of a particle on a rotating parabola by using efficient mathematical techniques

    Get PDF
    In this paper, nonlinear dynamics of a particle on a rotating parabola arising in the mechanical engineering is proposed. Two efficient mathematical techniques called variational iteration method and variational approach are used to solve the governing differential equation of motion. To assess the accuracy of solutions, we compare the results with the Runge-Kutta 4th order. An excellent agreement of solutions with the numerical results and published results has been demonstrated. The results reveal that the present methods are very effective and convenient in predicting the solution of such problems and find a wide application in new engineering problems

    Periodic solution to a nonlinear oscillator arising in micro electro mechanical system

    Get PDF
    In this paper, a periodic solution of nonlinear oscillator arising in the micro-beam based microelectromechanical system (MEMS) has been analytically achieved. The Amplitude Frequency Formulation (AFF) and Max Min Approach (MMA) have been used. In the second method (which is called MMA), an approximate solution of the nonlinear equation can be easily deduced by finding Maximal and minimal solution thresholds of this nonlinear problem. What we understood is that both methods, works properly and scales down the deal of the work. Compare conclusions with the results from fourth order Runge-Kutta method and energy balance method (EBM) shows that obtained results are of high accuracy and convenient

    Comparison of the Antifungal Activity of Titanium Dioxide Based Nano-Silver Packaging and Conventional Polyethylene Packaging in Consumed Bread

    Get PDF
    Using titanium dioxide nano-silver packaging, which is antibacterial and resistance to the diffusion of gases such as oxygen, is increasing in food industry. Therefore, we compared the effect of titanium dioxide-based nano-silver packaging and conventional polyethylene packaging on the fungal flora of consuming bread in order to increase the shelf-life storage of consuming bread. One hundred forty four samples of 6 different types of loaf of bread were randomly obtained from 12 bakeries in District 2 of Tehran. The samples were packaged with 3%, 5% and 10% nano-coatings, and also conventional polyethylene coatings as the control group. The bacterial examination and monitoring of samples, according to the national standards of Iran, was carried out 3 times, on the days 1, 3, 7, 14 and 28 of the study period. This study showed that the film type and storage period were the main factors, which significantly influenced the fungal flora of bread. The lowest rate of various fungi growth (%14) was observed in the 10% nano-film, while the highest rate of various fungi growth (47%) was observed in the conventional polyethylene coating (P<0.001). With the increase of the storage period, the number of various fungi increased; however, this correlation was not similar in most of the breads and fungi types, and there were significant difference between them in this regard (P=0.001). According to the results of the present study, due to increasing population growth and in order to improve food security, the use of packages with nano-silver particles, which are based on titanium dioxide, prevails over the polyethylene packages. Therefore, using such packages is highly recommended in the bakery industry

    Comparison the functional properties of protein hydrolysates from poultry by-products and rainbow trout (Onchorhynchus mykiss) viscera

    Get PDF
    Poultry by-products and rainbow trout (Onchorhynchus mykiss) viscera are abundant and underutilized resources that can be used as a unique protein source to make protein hydrolysates. In this study protein hydrolysate were made from these two different sources with Alcalase 2.4L. The functional properties of Fish viscera protein hydrolysate (FPH) compared to poultry by-products protein hydrolysate (PPH) were studied: Solubility, water holding capacity (WHC), oil absorption capacity (OAC), colour, emulsifying and foaming properties. Furthermore, the products were characterized by analyzing their amino acid composition. WHC, emulsifying activity, emulsifying stability and foaming properties and color of the FPH was significantly (P 0.05) different. Methionine and histidine in both protein hydrolysates were the limiting amino acids and FPH had more hydrophobic residue. The differences in the amino acid composition between PPH and FPH may also be responsible for their different behaviours at various pH

    Nanobiosensor designing with molecular framework polymer method compared with agent-linked nanosilica biosensor for Staphylococcus aureus exotoxin detection

    Get PDF
    Considering the ever increasing population and industrialization leading to developmental trend of humankind's life, we are hardly able to detect the toxins produced in food products using traditional techniques. In this technique, the production of molecular framework and polymer is done using meta acrylic acid monomers, which are formed via covalence connection between meta acrylic acid monomers (MAA) of white polymer. Here also hydrogenised connection between exotoxin amino acid and meta acrylic acid is made that would function as the selective absorption for that. Then in the second stage, based on the bacterial antibody connection to nanoparticle, a sensor was used. In this part of the research, as the basis for absorption for the recognition of bacterial toxin, medium sized silica nanoparticles of 10 nanometer in the form of solid powder were utilized with Notrino brand. Then the suspension produced from agent-linked nanosilica which was connected to bacterial antibody was positioned near the samples of distilled water, that were contaminated with Staphylococcus aureus bacterial toxin with the density of 10^-3, so that in case any toxin exists in the sample, a connection between toxin antigen and antibody would be formed. Finally, the light absorption related to the connection of antigen to the particle attached antibody was measured using spectrophotometers. The results indicate that the molecular framework polymer sensor is capable of detecting up to the density of 10^-3, but not lower than that, whereas using the second sensor, up to 10^-4 of density is detectable. Additionally, the sensitivity of the sensors were examined after 60 days and the first sensor by the day of 28 and the second sensor by the 56 day had confirmatory results and started to decrease after those time periods

    Effect of nanosilver particles on hatchability of rainbow trout (Oncorhynchus mykiss) egg and survival of the produced larvae

    Get PDF
    Effect of nanosilver particles was studied on the hatchability of rainbow trout (Oncorhynchus mykiss) egg and survival of the produced larvae at about 12ºC. In the first experiment the water-based nanosilver particles was used at concentrations of 0.5, 1, 2 and 4 mgL^-1 for 30 minutes per day starting 24 hour post egg incubation until the hatching time. The mean percentage of hatchability reached in 27.6±0.2, 38.2±0.1, 41.6±0.4 and 48.6±1.5 in troughs treated with 0.5, 1, 2 and 4 mgL^-1 nanocid, respectively compared with 64.7±0.2 % for trough treated with malachite green at 2 mgL^-1 as positive control (P0.05). These data suggest a possible application of nanosilver particles in aquaculture sector particularly using incubator troughs of trout containing nanosilver materials

    The Staphylococcus aureus Exotoxin Recognition Using a Sensor Designed by Nanosilica and SEA genotyping by Multiplex PCR

    Get PDF
    Considering the ever increasing population and industrialization of the developmental trend of human life, we are no longer able to detect the toxins produced in food products using the traditional techniques. This is due to the fact that the isolation time for food products is not cost-effective, and even in most of the cases, the precision of practical techniques like bacterial cultivation and other techniques suffers from operator errors, or the errors of the mixtures used. Hence, with the advent of nanotechnology, the design of selective and smart sensors has turned into one of the greatest industrial revelations of the quality control of food products that, in few minutes time and with a very high precision, can identify the volume and toxicity of the bacteria. In this research, based on the bacterial antibody's connection to nanoparticles, a sensor was used. In this part of the research, as the basis for absorption for the recognition of bacterial toxin, medium sized silica nanoparticles of 10 nm in the form of solid powder were utilized with Notrino brand. Then the suspension produced from the agent-linked nanosilica, which was connected to the bacterial antibody, was positioned near the samples of distilled water, which were contaminated with Staphylococcus aureus bacterial toxin with the density of  10-3 molar, so that in case any toxin exists in the sample, a connection between the toxin antigen and the antibody would be formed. Finally, the light absorption related to the connection of antigen to the particle-attached antibody was measured using spectrophotometry. The 23S rRNA gene that is conserved in all Staphylococcus spp. was used as the control. The accuracy of the test was monitored by using the serial dilution (l0-6) of overnight cell culture of Staphylococcus spp. bacteria (OD600: 0.02 = 107 cell). It showed that the sensitivity of PCR is 10 bacteria per ml of cells within few hours. The results indicated that the sensor detects up to 10-4molar density. Additionally, the sensitivity of the sensor was examined after 60 days; by the 56 day, it had confirmatory results, which started to decrease after this time. Comparison of practical nanobiosensory method with the conventional methods including culture and bio-technology methods (such as polymerase chain reaction) confirmed its accuracy, sensitiveness and uniqueness.  It also reduces the time from hours to 30 minutes

    Ectoparasite infection of Carassius carassius in water resources of west Azerbaijan, Iran

    Get PDF
    Various parasite species were found in Carassius carassius including Diplostomum spathaceum, Dactylogyrus sp.,Gyrodactylus sp. Ichthyophthirius multifiliis and Trichodinia sp . They were found in four rivers in West Azerbaijan Province (North-Western Iran) . A total of 207 live Carassius carassius from four rivers including Aras (72) Zariyneh (42) Nazlo (58) and Barandoz (35) were studied. Parasitological surveys were carried out on gills and external organs. The results showed that Diplostomum spathaceum (70.83%) Dactylogyrus sp. (38.88%) Gyrodactylus sp. ) 22.22%) Ichthyophthirius multifiliis (48.61%) Trichodinia sp. (8.33%) Chilodonella sp. (12.50%) and Argulus sp. (76.19%) were found in fish from Aras Rive so that the result showed, Spathaceum (63.79%) Dactylogyrus sp. (36.20%) Gyrodactylus sp. (25.86%) Ichthyophthirius multifiliis (44.82%) Trichodinia sp. (18.96%) Chilodonella sp. (12.06%) and Argulus sp. (6.89%). Argulus prevalence was greater in Barandoz River while Chilodonella in Zariyneh rud River . In Barandoz River, Diplostomum spathaceum (65.71%) Dactylogyrus sp. (37.14%) Gyrodactylus sp. (22.85%) Ichthyophthirius multifiliis (31.42%) Trichodinia sp. (25.71%) Chilodonella sp. (8.57%) and Argulus sp. (5.71%) were reported, respectively. Finally, in Zariyneh rud river, the followings have been reported: Diplostomum spathaceum (76.19%) Dactylogyrus sp. (21.42%) Gyrodactylus sp. (14.28%) Ichthyophthirius multifiliis (52.38%) Trichodinia sp. (23.80%) Chilodonella sp. (14.28%) and Argulus sp. (7.14%). It should be noted that prevalence , intensity and host parasite relationship will be discussed in details in this article

    Effect of Four Chicken Carcass Transportation Methods at Selected Room Temperatures on the Bacterial Load of Staphylococcus aureus, Salmonella Species, and Escherichia coli

    Get PDF
    Pathogenic bacteria are responsible for a significant number of food poisonings in humans through infected poultries. The main objective of this study was to assess the effect of transportation of chicken carcasses at 18-24, 4-5, and 10-14 oC on the bacterial loads of Staphylococcus aureus, Salmonella species, and Escherichia coli. This study was conducted on 180 fresh chicken carcasses (1197.0±19.88 g) randomly collected from a commercial poultry processing plant in southern Tehran, Iran, in a hot season in 2015. The sampling was performed at two stages, namely post-chilled washing and after 4 h of transportation. In the latter stage, the samples were selected from three vehicles with three types of temperatures. These vehicles included a pickup (18-24 oC), a refrigerated car (4-5 oC), and a refrigerated vehicle with switched off refrigerator (10-14 oC). According to the results, the whole body carcass samples transported at the pickup temperature had the highest mean total count (18.63×106±2.82×106 cfu.ml-1) and was greater (
    • …
    corecore