The Experts below are selected from a list of 73944 Experts worldwide ranked by ideXlab platform
Changying Li - One of the best experts on this subject based on the ideXlab platform.
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Monte Carlo simulation of light propagation in healthy and diseased Onion bulbs with multiple layers
Computers and Electronics in Agriculture, 2015Co-Authors: Svyatoslav Chugunov, Changying LiAbstract:Light propagation in 18-layer Onion bulbs was simulated by Monte Carlo method.18 cases of infected Onions demonstrated potential for nondestructive detection.Confident detection was determined with infection as deep as in the 3rd scale.Optimal window for disease detection was 670-870nm especially at 800nm.Spatially-resolved reflectance was effective to detect Neck Rot-infected Onions. It remains unanswered how the light interacts with healthy and pathogen-infected Onion tissues in a multi-layer structure. The overall goal of this study was to simulate light propagation (including scattering and absorption) in healthy and pathogen-infected Onion bulbs in the visible and near infrared (NIR) range using Monte Carlo simulations. Healthy Onions and bulbs infected with two major Onion post-harvest diseases, Botritis Allii (Neck Rot) and Burkholderia Cepacia (Sour Skin), were considered as the subjects of the simulation. Multi-layered models (18 layers in total) of healthy and infected Onion bulbs were developed representing Onion structure in the form of parallel slabs. Variance of optical properties was introduced into the models using median and quartile values computed from the experimental data. Monte Carlo-simulations were performed for the developed models to generate optical responses of 33 cases of healthy and infected Onions representing different stages of disease propagation in the spectral range 550-1650nm. Optical responses of all the cases were assessed with statistical tests. Study of spatially-resolved scattering reflectance was conducted to identify patterns typical for infected Onions. Optical responses were measured experimentally to validate the simulation results for healthy Onions. A total of 18 configurations (out of 33) of infected Onions showed significant difference from healthy bulbs and demonstrated great potential for nondestructive detection. Confident detection was determined for Onions with infection as deep as in the 3rd scale. The proposed optimal window for disease detection was 670-870nm. The greatest discrepancy between optical response of infected and healthy Onions was found at 800nm. Spatially-resolved reflectance of the Neck Rot-infected Onions showed consistent lower intensity than that of healthy Onions over the entire studied radial range, whereas the Sour Skin-infected Onions exhibited differences in a limited radial range. Light penetration simulation revealed that photons can reach 5-6mm deep in the bulb in the case of one dry skin in the wavelength of around 800nm and 1100nm. Validation results suggested that although the overall pattern of the simulated results and experimental measurements was similar, the systematic error was likely caused by the curvature of the Onion bulb and the measurement instrument. This study was the first attempt to use Monte Carlo simulations in the field of post-harvest research to model complex tissues of vegetables using more than 2 layers. The results of the simulation could be useful in developing non-destructive optical sensing methods for Onions.
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A multimodal machine vision system for quality inspection of Onions
Journal of Food Engineering, 2015Co-Authors: Weilin Wang, Changying LiAbstract:Abstract A multimodal machine vision system was developed to evaluate quality factors of Onions holistically and nondestructively. The system integrated hyperspectral, 3D, and X-ray imaging sensors. A LabVIEW program was developed to acquire color images, spectral images, depth images, X-ray images of Onions, and measure the weight of Onions. With the multimodal data collected, algorithms were developed to calculate the maximum diameter, volume, density, and detect latent defects of Onions. Three groups of sweet Onions (regular, inoculated with Burkholderia cepacia, and inoculated with Pseudomonas viridiflava) were tested. Results showed that the system accurately measured the weight (RMSE = 3.6 g), diameter (RMSE = 1.7 mm), volume (RMSE = 16.5 cm3), and density (RMSE = 0.03 g/cm3) of Onions, and correctly classified 88.9% healthy and defective Onions. This work demonstrated a promising approach to evaluate both external and internal quality parameters of Onions, which is applicable to Onion packinghouses. The proposed system and methods are also potentially applicable to quality inspection of other agricultural products.
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Optical Properties of Healthy and Sour Skin-infected Onion Tissues in Vis-NIR Region
2012 Dallas Texas July 29 - August 1 2012, 2012Co-Authors: Weilin Wang, R. D. Gitaitis, Changying Li, Ernest W. TollnerAbstract:As one of the most important ingredients of our diet, Onion is the second largest fresh vegetable in the U.S. To meet the increasing quality demand of consumers, modern optical techniques like hyperspectral imaging have been investigated to evaluate Onion quality nondestructively. To better apply these techniques, the optical properties of the dry skin and the flesh of healthy and sour skin infected Onions were measured in the wavelength range of 450-1000 nm. The total diffuse reflectance, total transmittance, and collimated transmittance spectra of Onion tissues were collected by using an integrating sphere system with a VIS-NIR spectrometer. The absorption coefficient (µa), reduced scattering coefficient (µ’s), and anisotropy (g) of the Onion tissues were calculated using the inverse adding-doubling method based on the measured spectra. The results showed that both Onion dry skin and flesh were scattering dominated biological tissues. The estimated µa and µ’s values of Onion dry skins and flesh were comparable to the optical properties of other fruits and vegetables reported in the literature. In the Vis-NIR range, the µa and µ’s of the flesh of sour skin-infected Onions were significantly different from those of the healthy Onions, which proved the possibility to inspect quality of Onion flesh by optical techniques. The results also suggested that Onion dry skins should be handled properly in optical measurements since they can significantly affect the light propagation. The results of this study can be used to develop appropriate optical techniques to improve quality control of Onions.
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Onion sour skin detection using a gas sensor array and support vector machine
Sensing and Instrumentation for Food Quality and Safety, 2009Co-Authors: Changying Li, Ron Gitaitis, Bill Tollner, Paul Sumner, Dan MacleanAbstract:Onion is a major vegetable crop in the world. However, various plant diseases, including sour skin caused by Burkholderia cepacia , pose a great threat to the Onion industry by reducing shelf-life and are responsible for significant postharvest losses in both conventional and controlled atmosphere (CA) storage. This study investigated a new sensing approach to detect sour skin using a gas sensor array and the support vector machine (SVM). Sour skin infected Onions were put in a concentration chamber for headspace accumulation and measured three to six days after inoculation. Principal component analysis (PCA) score plots showed two distinct clusters formed by healthy and sour skin infected Onions. The MANOVA statistical test further proved the hypothesis that the responses of the gas sensor array to healthy Onion bulbs and sour skin infected Onion bulbs are significantly different ( P
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Onion sour skin detection using a gas sensor array and support vector machine
Sensing and Instrumentation for Food Quality and Safety, 2009Co-Authors: Changying Li, Ron Gitaitis, Bill Tollner, Paul Sumner, Dan MacleanAbstract:Onion is a major vegetable crop in the world. However, various plant diseases, including sour skin caused by Burkholderia cepacia, pose a great threat to the Onion industry by reducing shelf-life and are responsible for significant postharvest losses in both conventional and controlled atmosphere (CA) storage. This study investigated a new sensing approach to detect sour skin using a gas sensor array and the support vector machine (SVM). Sour skin infected Onions were put in a concentration chamber for headspace accumulation and measured three to six days after inoculation. Principal component analysis (PCA) score plots showed two distinct clusters formed by healthy and sour skin infected Onions. The MANOVA statistical test further proved the hypothesis that the responses of the gas sensor array to healthy Onion bulbs and sour skin infected Onion bulbs are significantly different (P < 0.0001). The support vector machine was employed for the classification model development. The study was undertaken in two phases: model training and cross-validation within the training datasets and model validation using new datasets. The performances of three feature selection schemes were compared using the trained SVM model. The classification results showed that although the six-sensor scheme (with 81% sensor reduction) had a slightly lower correct classification rate in the training phase, it significantly outperformed its counterparts in the validation phase (85% vs. 69% and 67%). This result proved that effective feature selection strategy could improve the discrimination power of the gas sensor array. This study demonstrated the feasibility of using a gas sensor array coupled with the SVM for the detection of sour skin in sweet Onion bulbs. Early detection of sour skin will help reduce postharvest losses and secondary spread of bacteria in storage.
Weilin Wang - One of the best experts on this subject based on the ideXlab platform.
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A multimodal machine vision system for quality inspection of Onions
Journal of Food Engineering, 2015Co-Authors: Weilin Wang, Changying LiAbstract:Abstract A multimodal machine vision system was developed to evaluate quality factors of Onions holistically and nondestructively. The system integrated hyperspectral, 3D, and X-ray imaging sensors. A LabVIEW program was developed to acquire color images, spectral images, depth images, X-ray images of Onions, and measure the weight of Onions. With the multimodal data collected, algorithms were developed to calculate the maximum diameter, volume, density, and detect latent defects of Onions. Three groups of sweet Onions (regular, inoculated with Burkholderia cepacia, and inoculated with Pseudomonas viridiflava) were tested. Results showed that the system accurately measured the weight (RMSE = 3.6 g), diameter (RMSE = 1.7 mm), volume (RMSE = 16.5 cm3), and density (RMSE = 0.03 g/cm3) of Onions, and correctly classified 88.9% healthy and defective Onions. This work demonstrated a promising approach to evaluate both external and internal quality parameters of Onions, which is applicable to Onion packinghouses. The proposed system and methods are also potentially applicable to quality inspection of other agricultural products.
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A multiple sensor system for quality inspection of Onions and investigation of Onion optical properties
2013Co-Authors: Weilin WangAbstract:Understanding the optical properties of Onion tissues is essential to applying optical methods for Onion quality inspection. This study estimated the optical properties of dry skin, wet skin, and flesh of red, Vidalia sweet, white, and yellow Onions at the wavelength of 633 nm. The total diffuse reflectance, total transmittance, and collimated transmittance of single-layer Onion tissues were measured by spectroscopic systems. Based on the measured data, the absorption coefficient ua and reduced scattering coefficient us' of Onion tissues were calculated using the inverse adding-doubling method. The results indicated that the dry and wet skins had significantly higher ua and us' than the flesh at 633 nm. For both skins and flesh, the ua varied between cultivars, while the differences of the us' between cultivars were less profound. All types of Onion tissues were high-albedo materials at 633 nm. Using the calculated optical properties, Monte Carlo simulations were performed to model the light propagation in 25 different scenarios of multi-layer Onion tissues for four cultivars, respectively. The results showed that the incident light at 633 nm would lose 99% of its energy within 6 layers in any of the simulated scenarios, and the light penetrated more layers in the sweet Onions than in the other three cultivars. This work provided fundamental understanding of the optical properties of Onion tissues and the light propagation in Onion bulbs at 633 nm. The investigation of the Onion optical properties will be extended to a broader spectrum in the future.
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Optical Properties of Healthy and Sour Skin-infected Onion Tissues in Vis-NIR Region
2012 Dallas Texas July 29 - August 1 2012, 2012Co-Authors: Weilin Wang, R. D. Gitaitis, Changying Li, Ernest W. TollnerAbstract:As one of the most important ingredients of our diet, Onion is the second largest fresh vegetable in the U.S. To meet the increasing quality demand of consumers, modern optical techniques like hyperspectral imaging have been investigated to evaluate Onion quality nondestructively. To better apply these techniques, the optical properties of the dry skin and the flesh of healthy and sour skin infected Onions were measured in the wavelength range of 450-1000 nm. The total diffuse reflectance, total transmittance, and collimated transmittance spectra of Onion tissues were collected by using an integrating sphere system with a VIS-NIR spectrometer. The absorption coefficient (µa), reduced scattering coefficient (µ’s), and anisotropy (g) of the Onion tissues were calculated using the inverse adding-doubling method based on the measured spectra. The results showed that both Onion dry skin and flesh were scattering dominated biological tissues. The estimated µa and µ’s values of Onion dry skins and flesh were comparable to the optical properties of other fruits and vegetables reported in the literature. In the Vis-NIR range, the µa and µ’s of the flesh of sour skin-infected Onions were significantly different from those of the healthy Onions, which proved the possibility to inspect quality of Onion flesh by optical techniques. The results also suggested that Onion dry skins should be handled properly in optical measurements since they can significantly affect the light propagation. The results of this study can be used to develop appropriate optical techniques to improve quality control of Onions.
Tsutomu Takahashi - One of the best experts on this subject based on the ideXlab platform.
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Order-disorder transition of nOnionic Onions under shear flow
Langmuir, 2010Co-Authors: Yukiko Suganuma, Tadashi Kato, Masayuki Imai, Ulf Olsson, Tsutomu TakahashiAbstract:We have investigated the shear-induced ordering of multilamellar vesicles (Onions) in a nOnionic surfactant (C(12)E(4)) system using a small-angle light scattering (shear-SALS) and a small-angle X-ray scattering (shear-SAXS) technique. In a narrow shear rate-temperature space, the Onions form a two-dimensional (2D) hexagonally close-packed structure that shows characteristic hexagonal scattering patterns in both SALS and SAXS. In the dynamic phase diagram, the ordered Onion phase is surrounded by disordered Onion phase, indicating reentrant behavior against the temperature. The disorder-order transition is accompanied by a jump in Onion size by a factor of 5-6. In the disordered Onion phase, by applying a shear flow, the planar lamellar membranes transform to an intermediate structure, multilamellae cylinders or a coherent stripe buckling, and then the intermediate structure develops to the isotropic Onions. On the other hand, in the ordered Onion phase, the intermediate structure breaks to Onions stretched in the shear velocity direction, and then the stretched Onions aligned gradually to form the 2D hexagonal close packing.
Kirsimarja Oksmancaldentey - One of the best experts on this subject based on the ideXlab platform.
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comparison of antioxidant activities of Onion and garlic extracts by inhibition of lipid peroxidation and radical scavenging activity
Food Chemistry, 2003Co-Authors: Anna Maria Nuutila, Riitta Puupponenpimia, Marjukka Aarni, Kirsimarja OksmancaldenteyAbstract:The antioxidant activities of the methanol extracts of selected varieties and parts of garlic and Onion were determined by two methods: inhibition of lipid peroxidation induced by tert-butyl hydroperoxide in isolated rat hepatocytes and scavenging activity against diphenylpicrylhydrazyl radical. The total phenolics and the main flavonoids of the hydrolysed Onion and garlic samples were also analysed. The antioxidant activities obtained by the two methods were compared. Both methods gave similar antioxidant activities for pure compounds and Allium extracts. However, the radical scavenging method had many benefits compared to the lipid peroxidation method, being easier, cheaper, more specific and reproducible. The radical scavenging activities also correlated positively with the total phenolics of the extracts. Onions had clearly higher radical scavenging activities than garlic, red Onion being more active than yellow Onion. The skin extracts of Onion possessed the highest activities.
David A. C. Pink - One of the best experts on this subject based on the ideXlab platform.
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Assembly and characterisation of a unique Onion diversity set identifies resistance to Fusarium basal rot and improved seedling vigour
Theoretical and Applied Genetics, 2019Co-Authors: Andrew Taylor, Michael J. Havey, Graham R. Teakle, Peter G. Walley, William E. Finch-savage, Alison C. Jackson, Julie E. Jones, Paul Hand, Brian Thomas, David A. C. PinkAbstract:Key message A unique, global Onion diversity set was assembled, genotyped and phenotyped for beneficial traits. Accessions with strong basal rot resistance and increased seedling vigour were identified along with associated markers. Abstract Conserving biodiversity is critical for safeguarding future crop production. Onion ( Allium cepa L.) is a globally important crop with a very large (16 Gb per 1C) genome which has not been sequenced. While Onions are self-fertile, they suffer from severe inbreeding depression and as such are highly heterozygous as a result of out-crossing. Bulb formation is driven by daylength, and accessions are adapted to the local photoperiod. Onion seed is often directly sown in the field, and hence seedling establishment is a critical trait for production. Furthermore, Onion yield losses regularly occur worldwide due to Fusarium basal rot caused by Fusarium oxysporum f. sp. cepae . A globally relevant Onion diversity set, consisting of 10 half-sib families for each of 95 accessions, was assembled and genotyping carried out using 892 SNP markers. A moderate level of heterozygosity (30–35%) was observed, reflecting the outbreeding nature of the crop. Using inferred phylogenies, population structure and principal component analyses, most accessions grouped according to local daylength. A high level of intra-accession diversity was observed, but this was less than inter-accession diversity. Accessions with strong basal rot resistance and increased seedling vigour were identified along with associated markers, confirming the utility of the diversity set for discovering beneficial traits. The Onion diversity set and associated trait data therefore provide a valuable resource for future germplasm selection and Onion breeding.
