The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Yasuyoshi Hayata - One of the best experts on this subject based on the ideXlab platform.
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development of tio2 powder Coated food packaging Film and its ability to inactivate escherichia coli in vitro and in actual tests
International Journal of Food Microbiology, 2008Co-Authors: Chamorn Chawengkijwanich, Yasuyoshi HayataAbstract:Titanium dioxide (TiO2) has attracted a great deal of attention as a photocatalytic disinfecting material in the food and environmental industry. TiO2 has been used to inactivate a wide variety of microorganisms in many applications. In the present study, we aimed to develop a TiO2 powder-Coated packaging Film and clarify its ability to inactivate Escherichia coli both in vitro and in actual tests, using two different particle sizes and two types of illumination at different intensities. No inhibition effect of the testing method itself on the growth of E. coli was observed. The cells of E. coli were found to have decreased 3 log CFU/ml after 180 min of illumination by two 20 W black-light bulbs (wavelength of 300-400 nm) on TiO2-Coated oriented-polypropylene (OPP) Film, while E. coli decreased 1 log CFU/m with black-light illumination of unCoated OPP Film. The results showed that both ultraviolet A (UVA; wavelength of 315-400 nm) alone and TiO2-Coated OPP Film combined with UVA reduced the number of E. coli cell in vitro, but that the reduction of E. coli cell numbers was greater by TiO2-Coated OPP Film combined with UVA. The antimicrobial effect of TiO2-Coated Film is dependent on the UVA light intensity (0, <0.05 and 1 mW/cm2) and the kind of artificial light (black-light and daylight fluorescent bulbs), but it is independent of the particle size of TiO2 coating on the surface of OPP Film. The surviving cell numbers of E. coli on TiO2-Coated Film decreased 3 log and 0.35 log CFU/ml after 180 min of illumination by two 20 W black bulbs and two 20 W daylight fluorescent bulbs, respectively. Despite the lesser efficacy of the photocatalytic method with fluorescent lights, the survival of E. coli cells using this method was 50% of that using fluorescent lights alone. In the actual test, the number of E. coli cells from cut lettuce stored in a TiO2-Coated Film bag irradiated with UVA light decreased from 6.4 on Day 0 to 4.9 log CFU/g on Day 1, while that of an unCoated Film bag irradiated with UVA light decreased from 6.4 to 6.1 log CFU/g after 1 day of storage. The result shows that the TiO2-Coated Film could reduce the microbial contamination on the surface of solid food products and thus reduce the risks of microbial growth on fresh-cut produce.
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development of tio2 powder Coated food packaging Film and its ability to inactivate escherichia coli in vitro and in actual tests
International Journal of Food Microbiology, 2008Co-Authors: Chamorn Chawengkijwanich, Yasuyoshi HayataAbstract:Abstract Titanium dioxide (TiO2) has attracted a great deal of attention as a photocatalytic disinfecting material in the food and environmental industry. TiO2 has been used to inactivate a wide variety of microorganisms in many applications. In the present study, we aimed to develop a TiO2 powder-Coated packaging Film and clarify its ability to inactivate Escherichia coli both in vitro and in actual tests, using two different particle sizes and two types of illumination at different intensities. No inhibition effect of the testing method itself on the growth of E. coli was observed. The cells of E. coli were found to have decreased 3 log CFU/ml after 180 min of illumination by two 20 W black-light bulbs (wavelength of 300–400 nm) on TiO2-Coated oriented-polypropylene (OPP) Film, while E. coli decreased 1 log CFU/m with black-light illumination of unCoated OPP Film. The results showed that both ultraviolet A (UVA; wavelength of 315–400 nm) alone and TiO2-Coated OPP Film combined with UVA reduced the number of E. coli cell in vitro, but that the reduction of E. coli cell numbers was greater by TiO2-Coated OPP Film combined with UVA. The antimicrobial effect of TiO2-Coated Film is dependent on the UVA light intensity (0,
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development of tio2 powder Coated food packaging Film and its ability to inactivate escherichia coli in vitro and in actual tests
International Journal of Food Microbiology, 2008Co-Authors: Chamorn Chawengkijwanich, Yasuyoshi HayataAbstract:Abstract Titanium dioxide (TiO2) has attracted a great deal of attention as a photocatalytic disinfecting material in the food and environmental industry. TiO2 has been used to inactivate a wide variety of microorganisms in many applications. In the present study, we aimed to develop a TiO2 powder-Coated packaging Film and clarify its ability to inactivate Escherichia coli both in vitro and in actual tests, using two different particle sizes and two types of illumination at different intensities. No inhibition effect of the testing method itself on the growth of E. coli was observed. The cells of E. coli were found to have decreased 3 log CFU/ml after 180 min of illumination by two 20 W black-light bulbs (wavelength of 300–400 nm) on TiO2-Coated oriented-polypropylene (OPP) Film, while E. coli decreased 1 log CFU/m with black-light illumination of unCoated OPP Film. The results showed that both ultraviolet A (UVA; wavelength of 315–400 nm) alone and TiO2-Coated OPP Film combined with UVA reduced the number of E. coli cell in vitro, but that the reduction of E. coli cell numbers was greater by TiO2-Coated OPP Film combined with UVA. The antimicrobial effect of TiO2-Coated Film is dependent on the UVA light intensity (0,
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antifungal activity of tio2 photocatalysis against penicillium expansum in vitro and in fruit tests
International Journal of Food Microbiology, 2006Co-Authors: Chamorn Maneerat, Yasuyoshi HayataAbstract:Abstract The antifungal activity of TiO2 photocatalytic reaction in the form of TiO2 powder and TiO2 Coated on a plastic Film against Penicillium expansum was investigated in vitro and in fruit tests. The mixture of P. expansum conidial suspension and TiO2 powder was added to potato dextrose agar (PDA) plates for vitro test. The TiO2 photocatalytic reaction reduced conidial germination of the fungal pathogen. It was found that the ability of the TiO2 photocatalytic reaction to suppress P. expansum growth correlated to the amount of TiO2 added. Lower numbers of viable colonies of P. expansum were observed with increasing amount of TiO2. Regardless of the kind of selected fruit inoculated with P. expansum, both TiO2 powder and TiO2-Coated Film exhibited antifungal activity to control fruit rot. Development of Penicillium rot in apple was significantly (P = 0.05) retarded by the TiO2 photocatalytic reaction. Similarly the TiO2 photocatalytic reaction was the only treatment where no tomato fruit rot was noticeable after 1 week of storage. TiO2-Coated Film also decreased brown lesions and Penicillium rot infection in lemons. The mean severity fruit rot scores (browning and softening flesh) were 3.2 and 1.9 for unCoated and TiO2-Coated Film, respectively. Our findings suggest that “TiO2 photocatalytic reaction” shows antifungal activity against P. expansum which may have potential for postharvest disease control.
Marcio S Carvalho - One of the best experts on this subject based on the ideXlab platform.
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slot coating flows of non colloidal particle suspensions
Aiche Journal, 2017Co-Authors: Diego Martin Campana, Luis Valdez D Silva, Marcio S CarvalhoAbstract:Slot coating is used in the manufacturing of functional Films, which rely on specific particle microstructure to achieve the desired performance. Final structure on the Coated Film is strongly dependent on the suspension flow during the deposition of the coating liquid and on the subsequent drying process. Fundamental understanding on how particles are distributed in the Coated layer enables optimization of the process and quality of the produced Films. The complex coating flow leads to shear-induced particle migration and non-uniform particle distribution. We study slot coating flow of non-colloidal suspensions by solving the mass and momentum conservation equations coupled with a particle transport equation using the Galerkin/Finite element method. The results show that particle distribution in the coating bead and in the Coated layer is non-uniform and is strongly dependent on the imposed flow rate (wet thickness). © 2016 American Institute of Chemical Engineers AIChE J, 63: 1122–1131, 2017
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Particle migration and alignment in slot coating flows of elongated particle suspensions
Aiche Journal, 2017Co-Authors: I.r. Siqueira, R.b. Rebouças, Marcio S CarvalhoAbstract:We analyze slot coating flows of elongated particle suspensions and investigate particle concentration and average orientation at the Coated Film. Shear-induced particle migration is described by the Diffusive Flux Model, and particle orientation is given by the principal direction of the particle conformation tensor. The conformation evolution and the constitutive equation for the resulting complex liquid are adapted from classical models that describe the behavior of suspensions of cylinders and fibers and polymeric solutions of almost rigid rod-like molecules. The proposed fully coupled model is applied to slot coating flows, and is solved using the DEVSS-TG/SUPG Finite Element Method. The results show that the wet Coated Film is highly non-uniform. Particle concentration and orientation vary along the Film thickness and are a strong function of the operating parameters of the process, such as the Film thickness-to-coating gap ratio and the capillary number of the flow. This article is protected by copyright. All rights reserved.
Chamorn Chawengkijwanich - One of the best experts on this subject based on the ideXlab platform.
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development of tio2 powder Coated food packaging Film and its ability to inactivate escherichia coli in vitro and in actual tests
International Journal of Food Microbiology, 2008Co-Authors: Chamorn Chawengkijwanich, Yasuyoshi HayataAbstract:Titanium dioxide (TiO2) has attracted a great deal of attention as a photocatalytic disinfecting material in the food and environmental industry. TiO2 has been used to inactivate a wide variety of microorganisms in many applications. In the present study, we aimed to develop a TiO2 powder-Coated packaging Film and clarify its ability to inactivate Escherichia coli both in vitro and in actual tests, using two different particle sizes and two types of illumination at different intensities. No inhibition effect of the testing method itself on the growth of E. coli was observed. The cells of E. coli were found to have decreased 3 log CFU/ml after 180 min of illumination by two 20 W black-light bulbs (wavelength of 300-400 nm) on TiO2-Coated oriented-polypropylene (OPP) Film, while E. coli decreased 1 log CFU/m with black-light illumination of unCoated OPP Film. The results showed that both ultraviolet A (UVA; wavelength of 315-400 nm) alone and TiO2-Coated OPP Film combined with UVA reduced the number of E. coli cell in vitro, but that the reduction of E. coli cell numbers was greater by TiO2-Coated OPP Film combined with UVA. The antimicrobial effect of TiO2-Coated Film is dependent on the UVA light intensity (0, <0.05 and 1 mW/cm2) and the kind of artificial light (black-light and daylight fluorescent bulbs), but it is independent of the particle size of TiO2 coating on the surface of OPP Film. The surviving cell numbers of E. coli on TiO2-Coated Film decreased 3 log and 0.35 log CFU/ml after 180 min of illumination by two 20 W black bulbs and two 20 W daylight fluorescent bulbs, respectively. Despite the lesser efficacy of the photocatalytic method with fluorescent lights, the survival of E. coli cells using this method was 50% of that using fluorescent lights alone. In the actual test, the number of E. coli cells from cut lettuce stored in a TiO2-Coated Film bag irradiated with UVA light decreased from 6.4 on Day 0 to 4.9 log CFU/g on Day 1, while that of an unCoated Film bag irradiated with UVA light decreased from 6.4 to 6.1 log CFU/g after 1 day of storage. The result shows that the TiO2-Coated Film could reduce the microbial contamination on the surface of solid food products and thus reduce the risks of microbial growth on fresh-cut produce.
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development of tio2 powder Coated food packaging Film and its ability to inactivate escherichia coli in vitro and in actual tests
International Journal of Food Microbiology, 2008Co-Authors: Chamorn Chawengkijwanich, Yasuyoshi HayataAbstract:Abstract Titanium dioxide (TiO2) has attracted a great deal of attention as a photocatalytic disinfecting material in the food and environmental industry. TiO2 has been used to inactivate a wide variety of microorganisms in many applications. In the present study, we aimed to develop a TiO2 powder-Coated packaging Film and clarify its ability to inactivate Escherichia coli both in vitro and in actual tests, using two different particle sizes and two types of illumination at different intensities. No inhibition effect of the testing method itself on the growth of E. coli was observed. The cells of E. coli were found to have decreased 3 log CFU/ml after 180 min of illumination by two 20 W black-light bulbs (wavelength of 300–400 nm) on TiO2-Coated oriented-polypropylene (OPP) Film, while E. coli decreased 1 log CFU/m with black-light illumination of unCoated OPP Film. The results showed that both ultraviolet A (UVA; wavelength of 315–400 nm) alone and TiO2-Coated OPP Film combined with UVA reduced the number of E. coli cell in vitro, but that the reduction of E. coli cell numbers was greater by TiO2-Coated OPP Film combined with UVA. The antimicrobial effect of TiO2-Coated Film is dependent on the UVA light intensity (0,
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development of tio2 powder Coated food packaging Film and its ability to inactivate escherichia coli in vitro and in actual tests
International Journal of Food Microbiology, 2008Co-Authors: Chamorn Chawengkijwanich, Yasuyoshi HayataAbstract:Abstract Titanium dioxide (TiO2) has attracted a great deal of attention as a photocatalytic disinfecting material in the food and environmental industry. TiO2 has been used to inactivate a wide variety of microorganisms in many applications. In the present study, we aimed to develop a TiO2 powder-Coated packaging Film and clarify its ability to inactivate Escherichia coli both in vitro and in actual tests, using two different particle sizes and two types of illumination at different intensities. No inhibition effect of the testing method itself on the growth of E. coli was observed. The cells of E. coli were found to have decreased 3 log CFU/ml after 180 min of illumination by two 20 W black-light bulbs (wavelength of 300–400 nm) on TiO2-Coated oriented-polypropylene (OPP) Film, while E. coli decreased 1 log CFU/m with black-light illumination of unCoated OPP Film. The results showed that both ultraviolet A (UVA; wavelength of 315–400 nm) alone and TiO2-Coated OPP Film combined with UVA reduced the number of E. coli cell in vitro, but that the reduction of E. coli cell numbers was greater by TiO2-Coated OPP Film combined with UVA. The antimicrobial effect of TiO2-Coated Film is dependent on the UVA light intensity (0,
Tatsuhiko Yamanaka - One of the best experts on this subject based on the ideXlab platform.
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uniform laser ablation via photovoltaic effect of phthalocyanine perylene derivative
Applied Surface Science, 2002Co-Authors: Keiji Nagai, Hidetsugu Yoshida, T Norimatsu, Noriaki Miyanaga, Yasukazu Izawa, Tatsuhiko YamanakaAbstract:Abstract A uniform laser ablation was observed in a polystyrene Film Coated with a photovoltaic perylene/phthalocyanine bilayer when an incident took place at an intensity range of 10 9 –10 10 W/cm 2 ( λ =1064 nm, 1.1 ns FWHM). Without the bilayer coating, the laser pulse formed spiky structures in the polystyrene Film as self-focusing traces of the laser pulse, while for the Coated Film, the uniform surface ablation trace without the spiky interior structures was observed. In the case of incident of 532 nm where the coating material exhibits no reflection, such difference depending the coating was not observed. These phenomena were coupled with the reflection and conduction properties via its photovoltaic effect, and agreed with the required ablation to achieve high-density compression of the fuel capsule for inertial fusion energy (IFE).
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photo reflection and laser ablation properties of phthalocyanine perylene derivative bilayer
Synthetic Metals, 2001Co-Authors: Keiji Nagai, Hidetsugu Yoshida, T Norimatsu, Noriaki Miyanaga, Yasukazu Izawa, Kenichiro Morishita, Tatsuhiko YamanakaAbstract:The photo-reflectance and laser-ablation properties ofa part of an organic solar cell, a perylene derivative and the phthalocyanine (denoted as PV/H 2 Pc) were investigated. The reflectance ofa PV/H 2 Pc bilayerwas higher than the single layer samples of H 2 Pc and PV. Considering the photovoltaic effect in the corresponding solar cell and chemically doped perylene, the present reflection was characterized to be the photo-generated carrier in the PV layer. The present property can be classified into organic reflectance-tunable material, and is useful as a coating material to realize uniform laser ablation. A remarkable difference was observed in laser ablation ofpolystyrene Film, in comparison with that of the PV/H 2 Pc bilayer, when 1060 nm laser incident took place on the coating material. Without the coating the laser pulse formed a spiky structure as a trace ofself-focusing, while for the Coated Film the ablation trace was from the upstream on the axis without a spiky structure. These phenomena are advantageous for the targets of direct-driven inertial fusion energy.
Dermot Ohare - One of the best experts on this subject based on the ideXlab platform.
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high gas barrier coating using non toxic nanosheet dispersions for flexible food packaging Film
Nature Communications, 2019Co-Authors: Kanittika Ruengkajorn, Danageorgiana Crivoi, Chunping Chen, Jeancharles Buffet, Dermot OhareAbstract:One of the major challenges in the circular economy relating to food packaging is the elimination of metallised Film which is currently the industry standard approach to achieve the necessary gas barrier performance. Here, we report the synthesis of high aspect ratio 2D non-toxic layered double hydroxide (LDH) nanosheet dispersions using a non-toxic exfoliation method in aqueous amino acid solution. High O2 and water vapour barrier coating Films can be prepared using food safe liquid dispersions through a bar coating process. The oxygen transmission rate (OTR) of 12 μm PET Coated Film can be reduced from 133.5 cc·m−2·day−1 to below the instrument detection limit (<0.005 cc·m−2·day−1). The water vapour transmission rate (WVTR) of the PET Film can be reduced from 8.99 g·m−2·day−1 to 0.04 g·m−2·day−1 after coating. Most importantly, these Coated Films are also transparent and mechanically robust, making them suitable for flexible food packing while also offering new recycling opportunities. Food packaging industry is in search of non-toxic, stable, and recyclable coatings acting as gas-barriers. Here the authors synthesise transparent Films meeting these requirements, based on high aspect ratio layered double hydroxide nanosheets obtained by exfoliation in aqueous amino acid solution.