The Experts below are selected from a list of 24624 Experts worldwide ranked by ideXlab platform
Innes C Cuthill - One of the best experts on this subject based on the ideXlab platform.
-
visual pigments cone Oil Droplets ocular media and predicted spectral sensitivity in the domestic turkey meleagris gallopavo
Vision Research, 1999Co-Authors: Nathan S Hart, J C Partridge, Innes C CuthillAbstract:A microspectrophotometric survey conducted on the retinal photoreceptors of the domestic turkey (Meleagris gallopavo) revealed the presence of five different types of vitamin A1-based visual pigment (rhodopsin) in seven different types of photoreceptor. A single class of rod contained a medium wavelength-sensitive visual pigment (wavelength of maximum absorbance, λmax, 504 nm). Four different types of single cone contained visual pigment maximally sensitive to wavelengths in either the long (LWS, λmax 564 nm), medium (MWS, λmax 505 nm), short (SWS, λmax 460 nm) or violet (VS, λmax 420 nm) spectral ranges. The LWS, MWS and SWS single cones contained pigmented Oil Droplets with cut-off wavelengths (λcut) at 514, 490 and 437 nm, respectively. The VS single cone contained a transparent Oil Droplet which displayed no significant absorbance above 330 nm. A single class of double cone was also identified, both the principal and accessory members of which contained the LWS cone visual pigment. The principal member contained an Oil Droplet with a λcut at 436 nm. No Oil Droplet was observed in the accessory member. The use of a glycerol-based cell mountant, which reduced wavelength dependent measurement artefacts in the microspectrophotometric measurements, is described. Predictions of cone effective spectral sensitivity, incorporating measurements of the spectral transmission of the ocular media, suggest that turkeys have considerable sensitivity to wavelengths in the ultraviolet-A (UV-A, 315–400 nm) spectral range. This has implications for both the visual ecology of wild birds and the welfare of intensively farmed individuals.
-
visual pigments Oil Droplets and cone photoreceptor distribution in the european starling sturnus vulgaris
The Journal of Experimental Biology, 1998Co-Authors: Nathan S Hart, J C Partridge, Innes C CuthillAbstract:Microspectrophotometric measurements of retinal photoreceptors from the European starling (Sturnus vulgaris) revealed four classes of single cone, containing visual pigments with wavelengths of maximum absorbance ( max) at 563, 504, 449 and close to 362 nm. The two longer-wave-sensitive single cones contained brightly coloured Oil Droplets which cut off light below 572 and 514 nm, respectively. The 449 nm max pigment was associated with a 'colourless' Oil Droplet with peak measured absorptance below 400 nm. The ultraviolet-sensitive visual pigment was paired with a transparent Oil Droplet which showed no significant absorption above 350 nm. A single class of double cone was identified, both members of which contained the longwave-sensitive ( max 563 nm) visual pigment. The principal member of the double cone contained an Oil Droplet with a topographically variable cut-off wavelength below 471 nm; the Oil Droplet found in the accessory member was only measured in the ventral retina and displayed three distinct peaks of absorption at approximately 430, 450 and 480 nm. Rod photoreceptors had a max at 503 nm. A new polynomial for fitting visual pigment templates to ultraviolet-sensitive visual pigment data is given. Topographic density measurements of the different cone classes were made using Nitroblue-tetrazolium chloride to label selectively bleached photoreceptors. The two classes of shortwave-sensitive single cone were more abundant in the dorsal retina, and longwave-sensitive single cones were notably less abundant in the dorso-temporal region of the retina, which subserves binocular vision.
-
visual pigments Oil Droplets and cone photoreceptor distribution in the european starling sturnus vulgaris
The Journal of Experimental Biology, 1998Co-Authors: Nathan S Hart, J C Partridge, Innes C CuthillAbstract:Microspectrophotometric measurements of retinal photoreceptors from the European starling (Sturnus vulgaris) revealed four classes of single cone, containing visual pigments with wavelengths of maximum absorbance ( max) at 563, 504, 449 and close to 362 nm. The two longer-wave-sensitive single cones contained brightly coloured Oil Droplets which cut off light below 572 and 514 nm, respectively. The 449 nm max pigment was associated with a 9colourless9 Oil Droplet with peak measured absorptance below 400 nm. The ultraviolet-sensitive visual pigment was paired with a transparent Oil Droplet which showed no significant absorption above 350 nm. A single class of double cone was identified, both members of which contained the longwave-sensitive ( max 563 nm) visual pigment. The principal member of the double cone contained an Oil Droplet with a topographically variable cut-off wavelength below 471 nm; the Oil Droplet found in the accessory member was only measured in the ventral retina and displayed three distinct peaks of absorption at approximately 430, 450 and 480 nm. Rod photoreceptors had a max at 503 nm. A new polynomial for fitting visual pigment templates to ultraviolet-sensitive visual pigment data is given. Topographic density measurements of the different cone classes were made using Nitroblue-tetrazolium chloride to label selectively bleached photoreceptors. The two classes of shortwave-sensitive single cone were more abundant in the dorsal retina, and longwave-sensitive single cones were notably less abundant in the dorso-temporal region of the retina, which subserves binocular vision.
Jacob H. Masliyah - One of the best experts on this subject based on the ideXlab platform.
-
creaming behavior of solids stabilized Oil in water emulsions
Industrial & Engineering Chemistry Research, 1997Co-Authors: Nianxi Yan, Jacob H. MasliyahAbstract:Creaming behavior of Oil-in-water emulsions stabilized by kaolinite clays was studied. The clays were treated with asphaltenes resulting in clays having different contact angles. It was found that the emulsion creaming velocity decreased and that the volume of the creamed emulsions increased with increasing clay concentration at the Oil Droplet surface. At a given initial clay concentration in the aqueous phase, a plot of the emulsion creaming velocity versus the square of the Oil Droplet diameter did not follow any rational hindered settling equation. At a constant clay concentration at the Oil Droplet surface, however, a plot of the emulsion creaming velocity versus the square of the effective Oil Droplet diameter gave a straight line passing through the origin. A model for creaming of solids-stabilized Oil-in-water emulsions was developed, and it is able to predict the creaming velocity of the emulsions quite well.
-
Characterization and demulsification of solids-stabilized Oil-in-water emulsions Part 1. Partitioning of clay particles and preparation of emulsions
Colloids and Surfaces A: Physicochemical and Engineering Aspects, 1995Co-Authors: Nianxi Yan, Jacob H. MasliyahAbstract:Kaolinite clay particles treated with asphaltenes were used to study the partitioning of the clay particles between an Oil-in-water emulsion and an aqueous phase. It was found that the interaction energy of the adsorbed particles and the equilibrium ratio of the clay concentration at the Oil Droplet surface to that in the bulk water were strong functions of the clay contact angle θ, for θ > 65°. For a given initial clay concentration in the bulk water and emulsification conditions, the variation of the Oil Droplet diameter with θ exhibited a minimum at θ ≈ 65°. Under similar emulsification conditions, a higher initial clay concentration in the bulk water resulted in the formation of smaller Oil Droplets and a larger volume of creamed emulsion. © 1995.
Nathan S Hart - One of the best experts on this subject based on the ideXlab platform.
-
visual pigments cone Oil Droplets ocular media and predicted spectral sensitivity in the domestic turkey meleagris gallopavo
Vision Research, 1999Co-Authors: Nathan S Hart, J C Partridge, Innes C CuthillAbstract:A microspectrophotometric survey conducted on the retinal photoreceptors of the domestic turkey (Meleagris gallopavo) revealed the presence of five different types of vitamin A1-based visual pigment (rhodopsin) in seven different types of photoreceptor. A single class of rod contained a medium wavelength-sensitive visual pigment (wavelength of maximum absorbance, λmax, 504 nm). Four different types of single cone contained visual pigment maximally sensitive to wavelengths in either the long (LWS, λmax 564 nm), medium (MWS, λmax 505 nm), short (SWS, λmax 460 nm) or violet (VS, λmax 420 nm) spectral ranges. The LWS, MWS and SWS single cones contained pigmented Oil Droplets with cut-off wavelengths (λcut) at 514, 490 and 437 nm, respectively. The VS single cone contained a transparent Oil Droplet which displayed no significant absorbance above 330 nm. A single class of double cone was also identified, both the principal and accessory members of which contained the LWS cone visual pigment. The principal member contained an Oil Droplet with a λcut at 436 nm. No Oil Droplet was observed in the accessory member. The use of a glycerol-based cell mountant, which reduced wavelength dependent measurement artefacts in the microspectrophotometric measurements, is described. Predictions of cone effective spectral sensitivity, incorporating measurements of the spectral transmission of the ocular media, suggest that turkeys have considerable sensitivity to wavelengths in the ultraviolet-A (UV-A, 315–400 nm) spectral range. This has implications for both the visual ecology of wild birds and the welfare of intensively farmed individuals.
-
visual pigments Oil Droplets and cone photoreceptor distribution in the european starling sturnus vulgaris
The Journal of Experimental Biology, 1998Co-Authors: Nathan S Hart, J C Partridge, Innes C CuthillAbstract:Microspectrophotometric measurements of retinal photoreceptors from the European starling (Sturnus vulgaris) revealed four classes of single cone, containing visual pigments with wavelengths of maximum absorbance ( max) at 563, 504, 449 and close to 362 nm. The two longer-wave-sensitive single cones contained brightly coloured Oil Droplets which cut off light below 572 and 514 nm, respectively. The 449 nm max pigment was associated with a 'colourless' Oil Droplet with peak measured absorptance below 400 nm. The ultraviolet-sensitive visual pigment was paired with a transparent Oil Droplet which showed no significant absorption above 350 nm. A single class of double cone was identified, both members of which contained the longwave-sensitive ( max 563 nm) visual pigment. The principal member of the double cone contained an Oil Droplet with a topographically variable cut-off wavelength below 471 nm; the Oil Droplet found in the accessory member was only measured in the ventral retina and displayed three distinct peaks of absorption at approximately 430, 450 and 480 nm. Rod photoreceptors had a max at 503 nm. A new polynomial for fitting visual pigment templates to ultraviolet-sensitive visual pigment data is given. Topographic density measurements of the different cone classes were made using Nitroblue-tetrazolium chloride to label selectively bleached photoreceptors. The two classes of shortwave-sensitive single cone were more abundant in the dorsal retina, and longwave-sensitive single cones were notably less abundant in the dorso-temporal region of the retina, which subserves binocular vision.
-
visual pigments Oil Droplets and cone photoreceptor distribution in the european starling sturnus vulgaris
The Journal of Experimental Biology, 1998Co-Authors: Nathan S Hart, J C Partridge, Innes C CuthillAbstract:Microspectrophotometric measurements of retinal photoreceptors from the European starling (Sturnus vulgaris) revealed four classes of single cone, containing visual pigments with wavelengths of maximum absorbance ( max) at 563, 504, 449 and close to 362 nm. The two longer-wave-sensitive single cones contained brightly coloured Oil Droplets which cut off light below 572 and 514 nm, respectively. The 449 nm max pigment was associated with a 9colourless9 Oil Droplet with peak measured absorptance below 400 nm. The ultraviolet-sensitive visual pigment was paired with a transparent Oil Droplet which showed no significant absorption above 350 nm. A single class of double cone was identified, both members of which contained the longwave-sensitive ( max 563 nm) visual pigment. The principal member of the double cone contained an Oil Droplet with a topographically variable cut-off wavelength below 471 nm; the Oil Droplet found in the accessory member was only measured in the ventral retina and displayed three distinct peaks of absorption at approximately 430, 450 and 480 nm. Rod photoreceptors had a max at 503 nm. A new polynomial for fitting visual pigment templates to ultraviolet-sensitive visual pigment data is given. Topographic density measurements of the different cone classes were made using Nitroblue-tetrazolium chloride to label selectively bleached photoreceptors. The two classes of shortwave-sensitive single cone were more abundant in the dorsal retina, and longwave-sensitive single cones were notably less abundant in the dorso-temporal region of the retina, which subserves binocular vision.
Volker Gaukel - One of the best experts on this subject based on the ideXlab platform.
-
Breakup and Coalescence of Oil Droplets in Protein-Stabilized Emulsions During the Atomization and the Drying Step of a Spray Drying Process
Food and Bioprocess Technology, 2021Co-Authors: Martha L. Taboada, Heike P. Karbstein, Doll Chutani, Volker GaukelAbstract:The goal of this study was to investigate the changes in Oil Droplet size in whey protein–stabilized emulsions during the atomization and the subsequent drying step of a spray drying process. For this purpose, experiments were performed in an atomization rig and a pilot spray dryer with two commercial pressure swirl atomizers. By comparing the Oil Droplet size before atomization, after atomization, and after spray drying, the changes in Oil Droplet size during each process step were quantified. The effect of Oil Droplet breakup during atomization was isolated by atomizing emulsions with 1 wt.% Oil content and a protein to Oil concentration ratio of 0.1. At 100 bar, the Sauter mean diameter of Oil Droplet size was reduced from 3.13 to 0.61 μm. Directly after breakup, coalescence of the Oil Droplets was observed for emulsions with a high Oil content of 30 wt.%, leading to a Droplet size after atomization of 1.15 μm. Increasing the protein to Oil concentration ratio to 0.2 reduced coalescence during atomization and Oil Droplets with a mean diameter of 0.92 μm were obtained. Further coalescence was observed during the drying step: for an Oil content of 30 wt.% and a protein to Oil concentration ratio of 0.1 the mean Droplet size increased to 1.77 μm. Powders produced at high Oil contents showed a strong tendency to clump. Comparable effects were observed for a spray drying process with a different nozzle at 250 bar. The results confirm that Droplet breakup and coalescence during atomization and coalescence during drying have to be taken into consideration when targeting specific Oil Droplet sizes in the product. This is relevant for product design in spray drying applications, in which the Oil Droplet size in the powder or after its redispersion determines product quality and stability.
-
Oil Droplet breakup during pressure swirl atomization of food emulsions influence of atomization pressure and initial Oil Droplet size
Journal of Food Process Engineering, 2021Co-Authors: Martha L. Taboada, Heike P. Karbstein, Annchristin Schafer, Volker GaukelAbstract:Atomization of emulsions with pressure swirl atomizers is a common task in food process engineering. Especially in spray drying processes for food materials like dairy products, it is the technology of choice. During atomization, emulsions are subjected to high stresses, which can lead to deformation and breakup of the dispersed Droplets. In this study, the influence of atomization pressure (5–20 MPa) and initial Oil Droplet size (0.26, 3.1, and 20.8 μm) on the Oil Droplet breakup during atomization of food based Oil‐in‐water emulsions with pressure swirl atomizers was investigated. It was shown that a significant Oil Droplet breakup takes place upon atomization. The size of Oil Droplets with an initial value of 3.1 and 20 μm was reduced up to 0.36 μm. No breakup of Oil Droplets with an initial value of 0.26 μm was observed. The breakup was highly dependent on the atomization pressure. The results were analyzed based on existing knowledge on Droplet breakup in laminar flow. A concept to estimate capillary numbers during atomization was developed based on common models from different applications. The results of this study can be used to control the resulting Oil Droplet size after atomization with pressure swirl atomizers. Practical application: Spray drying of emulsions is a widely used process in the food industry to produce products with encapsulated Oily components. Product examples include infant formula, milk powder, and the encapsulation of aroma and coloring compounds. Breakup of the Oil Droplets during the atomization step of spray drying can change a previously adjusted and desired Oil Droplet size. As the Oil Droplet size in the final product can be responsible for several properties like sensorial aspects and stability, a control of Oil Droplet breakup is essential. Pressure swirl atomizers are widely used in industrial applications as atomization devices. In this study, Oil Droplet breakup during atomization with these atomizers was investigated. The findings in this study allow a better control of the Oil Droplet size during atomization in practical applications.
-
Investigation of Oil Droplet Breakup during Atomization of Emulsions: Comparison of Pressure Swirl and Twin-Fluid Atomizers
'MDPI AG', 2021Co-Authors: Martha L. Taboada, Heike P. Karbstein, Esteban Zapata, Volker GaukelAbstract:The goal of this study was to investigate Oil Droplet breakup in food emulsions during atomization with pressure swirl (PS), internal mixing (IM), and external mixing (EM) twin-fluid atomizers. By this, new knowledge is provided that facilitates the design of atomization processes, taking into account atomization performance as well as product characteristics (Oil Droplet size). Atomization experiments were performed in pilot plant scale at liquid volume flow rates of 21.8, 28.0, and 33.3 L/h. Corresponding liquid pressures in the range of 50–200 bar and air-to-liquid ratios in the range of 0.03–0.5 were applied. Two approaches were followed: Oil Droplet breakup was initially compared for conditions by which the same spray Droplet sizes were achieved at constant liquid throughput. For all volume flow rates, the strongest Oil Droplet breakup was obtained with the PS nozzle, followed by the IM and the EM twin-fluid atomizer. In a second approach, the concept of energy density EV was used to characterize the sizes of resulting spray Droplets and of the dispersed Oil Droplets in the spray. For all nozzles, Sauter mean diameters of spray and Oil Droplets showed a power-law dependency on EV. PS nozzles achieved the smallest spray Droplet sizes and the strongest Oil Droplet breakup for a constant EV. In twin-fluid atomizers, the nozzle type (IM or EM) has a significant influence on the resulting Oil Droplet size, even when the resulting spray Droplet size is independent of this nozzle type. Overall, it was shown that the proposed concept of EV allows formulating process functions that simplify the design of atomization processes regarding both spray and Oil Droplet sizes
Taro Toyota - One of the best experts on this subject based on the ideXlab platform.
-
deformable self propelled micro object comprising underwater Oil Droplets
Scientific Reports, 2016Co-Authors: Taisuke Banno, Hiroyuki Kitahata, Arisa Asami, Naoko Ueno, Yuki Koyano, Kouichi Asakura, Taro ToyotaAbstract:The self-propelled motion with deformation of micrometer-sized soft matter in water has potential application not only for underwater carriers or probes in very narrow spaces but also for understanding cell locomotion in terms of non-equilibrium physics. As far as we know, there have been no reports about micrometer-sized self-propelled soft matter mimicking amoeboid motion underwater. Here, we report an artificial molecular system of underwater Oil Droplets exhibiting self-propelled motion with deformation as an initial experimental model. We describe the heterogeneity in a deformable self-propelled Oil Droplet system in aqueous and Oil phases and at their interface based on the behavior and interaction of surfactant and Oil molecules. The current results have great importance for scientific frontiers such as developing deformable micro-swimmers and exploring the emergence of self-locomotion of Oil Droplet-type protocells.
-
self propelled Oil Droplets consuming fuel surfactant
Journal of the American Chemical Society, 2009Co-Authors: Taro Toyota, Martin M Hanczyc, Naoto Maru, Takashi Ikegami, Tadashi SugawaraAbstract:A micrometer-sized Oil Droplet of 4-octylaniline containing 5 mol % of an amphiphilic catalyst exhibited a self-propelled motion, producing tiny Oil Droplets, in an aqueous dispersion of an amphiphilic precursor of 4-octylaniline. The tiny Droplets on the surface of the self-propelled Droplet were conveyed to the posterior surface and released to the aqueous solution. Thus the persistent movement becomes possible in this chemical system, because the processing of chemical energy to mechanical movement proceeds by consuming exogenous fuel, not consuming the Oil Droplet itself. The mechanism of the unidirectional motion is hypothesized in terms of an asymmetric interfacial tension around the surface of the Oil Droplet.
