42 research outputs found
Adenosquamous Carcinoma Presenting with Necrotising Mediastinal Lymphadenopathy in a Non-smoker Young Adult: A Rare Case Report
No full textCompeting Interests: The authors have declared that no competing interests exist. Consent: We confirm that the patient has given the informed consent for the case report to be published. Copyright: 2015 Takhar R et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited
The Women’s Movement and Neo-Liberalism in Iran: Between Accommodation and Resistance
No full textPurpose
This chapter analyses the strategies employed by women and youth political activists in Iran in the context of changes engendered by the neo-liberal policies pursued by successive governments since the end of the Iran-Iraq war.
Design/methodology/approach
The analysis in this chapter is based on semi-structured interviews conducted by the author with women and youth activists in Iran in 2015. This qualitative data is contextualised within a theoretical discussion of the nature of the Iranian state, the impact of neo-liberal policies, and debates surrounding gender and neo-liberalism.
Findings
Contrary to the view of politics in Iran as a battle between hard-line religious fundamentalists and moderates, this chapter argues that it is not the religious nature of the state but its neo-liberal policies that have made it more difficult for women and youth activists to mobilise against the exclusionary policies of the state. In response activists in Iran have developed and articulated strategies of resistance to and accommodation with the Islamic Republic’s neo-liberal project.
Originality/value
The chapter breaks with prevailing socio-cultural analyses of women’s rights in Iran and provides a critique of prevalent ideas of women’s rights as innately connected to liberal and specifically neo-liberal forms of politics and governance
The Effect of Chemical Regulations on the Aerospace and Defence Industries
No full textThe motivation for this research stems from the author working within the Aerospace and Defence (AD) sector for nearly 19 years. It was during the development phase of IPC-1754 data exchange standard, the author, came to the firm belief, that whilst AD supply chain actors would begin to share data in a harmonised format via the IPC-1754 data exchange standard, there was a clear lack of understanding amongst several AD supply chain actors on how to collate, analyse, assess, and report internal data in a consistent manner.
The main aim of this research is: To develop a conceptual framework enabling identification of articles (products) potentially at risk from chemical regulations supporting decision making processes for AD organisations
Microstructural and fluid transport properties of potatoes during frying
No full textMicrostructural and transport properties are the key determinants to understand the product quality, oil uptake and moisture loss during frying of foods. Besides, permeability is also an important physical property for studying the transport mechanisms of porous foods when pressure driven flow is involved. Food processes like frying, drying, solvent extraction, microwave heating, baking, membrane separation and reverse osmosis have significant pressure development. Experiments were conducted to investigate the microsructural changes during frying of potato disc and determine the oil and water permeability of potato disc at different temperatures.
The complex microstructural changes and mass transfer mechanisms in potato discs during frying were analyzed. The potato discs (thickness of 1.65mm) were fried at 190C for 0, 20, 40, 60 and 80 s and X-ray micro-computed tomography (CT) was used for three-dimensional (3D) imaging of microstructure of porous potato discs for different frying durations. Total porosity, pore size distribution, oil content and air content of potato discs were calculated from resulting 3D data sets. Oil and air content measured by analysis of micro-CT images followed trends similar to Soxtec and Pycnometer methods, respectively. Image analysis showed a significant change in pore size distribution as a function of frying time. Frying time was also observed to have an effect on tortuosity, which is an important microstructural transport property. Tortuosity was measured by path length ratio method from 3D data sets obtained from image analysis. A linear inverse relationship was observed between porosity and tortuosity where tortuosity decreased with the increase of porosity. During frying, oil content increased with the decrease of tortuosity. This phenomenon indicated that the lower tortuosity created a less complicated and sinuous path, thus resulting in less resistance to oil penetration. Micro-CT technique can serve as an effective tool for elucidating microstructure of fried foods, and can provide complementary information to conventional lab techniques.
The permeability values of water and oil through porous potato discs were determined by developing an engineering model using Darcy's law relation, mass balance equation and poroelasticity relations at temperatures within 25C - 80C. A finite element package (COMSOL Multiphysics ver. 5.0, Burlington, MA) was used to solve these equations to obtain the velocity profiles at different pressure levels. The water permeability values determined from the velocity profiles were in the range of (2 to 4) x for the temperature range from to and the oil permeability were in the range of (2 to 12)x for temperature range from to under the applied pressure of 138 to 348 kPa. The predicted velocity-pressure gradient curves for obtaining permeability values showed good agreement with the experimental velocity-pressure gradient data points. An Arrhenius model was developed to represent the relationship between permeability, fluid content (water or oil) and temperature. In case of pressure driven water flow, swelling occurred in the potato disc below 50C and compression occurred above this temperature, while in case of oil, compression occurred at all temperatures. The velocity-pressure gradient behavior of oil and water through potato disc exhibited deviation from Darcy's law due to threshold pressure gradient.Submission published under a 24 month embargo labeled 'U of I Access', the embargo will last until 2017-12-01The student, Tanjila Alam, accepted the attached license on 2015-12-06 at 23:30.The student, Tanjila Alam, submitted this Thesis for approval on 2015-12-06 at 23:43.This Thesis was approved for publication on 2015-12-09 at 09:24.DSpace SAF Submission Ingestion Package generated from Vireo submission #8946 on 2016-03-02 at 14:07:49Made available in DSpace on 2016-03-02T20:24:14Z (GMT). No. of bitstreams: 2
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Multiscale continuum thermodynamics based modeling of transport mechanisms and starch expansion during extrusion
No full textExpansion is a very critical process that affects the final structural, mechanical and textural characteristics of the extruded products. An understanding of the expansion phenomenon is necessary in order to control and/or improve the functionality of starch products. The hybrid mixture theory based model developed by Takhar (2014) was used to obtain a computer model, which can be used to design, optimize and/or control the process conditions, and improve the specific characteristics of expanded biopolymers. Water, vapor and heat transport mechanisms and thermo–mechanical changes occurring inside the expanding extrudate were described using the two–scale unsaturated transport equations coupled with the poroviscoelasticity equations. The poroviscoelastic extrudate matrix interacted with the fluids (liquid water, vapor and air mixture) contained in its pores. Transport equations were transformed from the moving Eulerian coordinates to the stationary Lagrangian coordinates. Good agreements between the simulated and the experimental values of surface temperature, moisture content and expansion ratio of the extrudates at different extrusion conditions were obtained. Simulations showed the transition from rubbery to glassy state at different spatial locations across the cross–section of the extrudate. The model was also used to predict the temperature, moisture content, and pressure distribution within the extrudate. The extrudate moisture content deceased after exiting from the die due to water evaporation, which resulted in an increase in the glass transition temperature. Therefore, a glassy crust was developed from the surface to interior. An increase in pore pressure of the extrudate caused rapid starch expansion until it reached a maximum. The extrudate stopped expanding when the pore pressure gradient became zero, and collapsed when the pore pressure reduced further to make a negative pressure gradient.
The viscoelastic properties also provide an indication about the textural characteristics of starch as a function of extrusion conditions. The viscoelastic properties of extruded cornstarch were measured as a function of process conditions. The extruded cornstarch samples were conditioned in the moisture range of 12.9–31.2% (dry basis). Dynamic and creep behavior of the extrudate were evaluated using a dynamic mechanical analyzer. The storage (G′) and loss moduli (G′′) were determined in the temperature range of 30-100°C and oscillation frequency range of 0.1-51 Hz. The G′ and G″ values showed an increasing trend with a decrease in temperature and moisture content and an increase in frequency. This implied an increase in solid-like behavior when the temperature and moisture content were reduced or the frequency was increased. Rheological parameters based on creep behavior were assessed at 30, 60 and 85°C. Creep data, fitted using Burger’s model, were highly dependent on both moisture content and temperature. The viscoelastic properties obtained in this experimental research were used in the transport model for studying the expansion of starch during extrusion.
For validating the predictive model, expansion experiments were conducted. Three response parameters (apparent density, porosity and expansion ratio) were examined for investigating the expansion characteristics of cornstarch as a function of extrusion conditions. Cornstarch with moisture contents of 18.3, 26.1 and 34.8% (dry basis) were extrusion cooked in a twin-screw extruder at barrel temperatures of 120 and 140°C and screw speeds of 200, 300 and 400 rpm. Results indicated that feed moisture content, barrel temperature and screw speed had significant effects on the density, porosity and expansion ratio of extruded cornstarch products (p<0.05). Increases in feed moisture content resulted in increases in bulk density and decreases in porosity and expansion ratio (p<0.05). Increases in barrel temperature and screw speed resulted in decreases in bulk density and increase in porosity and expansion ratio (p<0.05). In addition, the moisture content and surface temperature of the extruded products were influenced by extrusion conditions. Lowering the feed moisture content and increasing the barrel temperature and screw speed caused a lower moisture content and higher surface temperature of the cornstarch extrudates (p<0.05).Submission published under a 24 month embargo labeled 'Closed Access', the embargo will last until 2017-05-01The student, Srivikorn Dit-U-Dompo, accepted the attached license on 2015-02-22 at 23:54.The student, Srivikorn Dit-U-Dompo, submitted this Dissertation for approval on 2015-02-23 at 00:12.This Dissertation was approved for publication on 2015-02-27 at 08:09.DSpace SAF Submission Ingestion Package generated from Vireo submission #7724 on 2015-07-22 at 14:24:01Made available in DSpace on 2015-07-22T22:45:01Z (GMT). No. of bitstreams: 2
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Enzymatic hydrolysis and fermentation of soy flour to produce ethanol and soy protein concentrate with increased polyphenols
No full textSubmission published under a 24 month embargo labeled 'U of I Access', the embargo will last until 2023-12-01The student, Ruchir Agrawal, accepted the attached license on 2021-10-14 at 18:47.The student, Ruchir Agrawal, submitted this Thesis for approval on 2021-10-14 at 22:16.This Thesis was approved for publication on 2021-10-19 at 15:30.DSpace SAF Submission Ingestion Package generated from Vireo submission #17162 on 2022-04-06 at 17:16:47Made available in DSpace on 2022-04-29T21:42:56Z (GMT). No. of bitstreams: 2
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Reason: Author requested U of Illinois access only (OA after 2yrs) in Vireo ETD systemAuthor requested U of Illinois access only (OA after 2yrs) in Vireo ETD systemU of I OnlyDefatted soybean flour (DSF) is a protein-rich ingredient; however, it contains 30-35% carbohydrates, which is made up in parts by sucrose, flatulence-causing oligosaccharides, and water-insoluble cell-wall polysaccharides. A process was developed to produce soy protein concentrates (SPC) by substantially hydrolyzing these carbohydrates with the help of enzymes into water-soluble saccharides and monomeric sugars, which were simultaneously utilized by Saccharomyces cerevisiae for fermentation into ethanol. The enzyme mixture consisted of a cellulase blend, pectinase blend, and α-galactosidase. The effect of process time on SPC protein concentration, overall protein recovery, carbohydrate hydrolysis, yeast growth, ethanol concentration, and total polyphenol concentration of SPC and hydrolysate were evaluated. Control and enzymes-only (EO) systems were maintained in conjunction with the enzymes + yeast (EY) system to individually assess the impact of isoelectric precipitation of soy proteins and enzymatic hydrolysis of carbohydrates without yeasts in the production of SPC. After 12.25 hours of EY process, 100 g of dry DSF produced 68.45 g dry SPC containing 72.23 ± 0.25% protein and 384 mL hydrolysate containing 9.76 ± 0.05 mg/mL ethanol. Protein recovery from DSF in the form of SPC was 84.4 ± 0.4%. Viable yeast count steadily declined from 1.6 ± 0.1×106 CFU/mL slurry at the start of the process to 7.9 ± 1.3×105 CFU/mL slurry after 12.25 hours. Flatulence causing raffinose-series-oligosaccharides were completely hydrolyzed into their monomeric sugars during this process. Total soluble carbohydrates in the EY treatment were consistently lower than control and EO treatment, suggesting that the yeasts were able to ferment sugars as they were becoming available. Total polyphenol concentration (TPC) of SPC increased more than twofold from 1.21 ± 0.04 mg gallic acid equivalent (GAE)/g dry SPC in control to 3.06 ± 0.03 mg GAE/g dry SPC in EY treatment. Similarly, hydrolysate TPC increased twofold from 179 ± 1 μg/mL in control to 371 ± 6 μg/mL in EY treatment. Thus, this novel process led to a protein and polyphenol-rich and reduced-carbohydrate SPC along with polyphenol and ethanol-containing hydrolysate
Multiscale modeling of moisture transport coupled with quality changes in selected foods
No full textThe availability and movement of water inside the food materials play essential roles for food stability by affecting their physical and chemical properties, and microbiological activity. Understanding the moisture transport is a necessary step to control food properties. Food processing unit operations, like drying and sorption, influence the behavior of foods. These processes alter many aspects of foods such as acceptability, nutritional value, quality, and shelf-life. Understanding the water transport in foods and the changes occurring in functional properties has a great importance in describing and modeling their sorption and drying behavior. Due to complexity and dynamic nature of the drying and sorption processes, purely experimental methods are not capable of obtaining information on transport mechanisms. In other words, experimental methods can only be used to express one process condition. Therefore, there is a need for a general modeling approach to express the sorption and drying processes, which would allow predicting not only the water transport but also the quality attributes of the product during the process as a function of process conditions. Primary mechanisms occurring during water transport such as moisture sorption, swelling/shrinkage, and glass transition were incorporated using hybrid mixture theory (HMT)-based multiscale modeling approach (Chapter 2).
It is important to understand the viscoelastic properties of cereals since they affect product texture as a result of moisture transport. The stress relaxation behavior of oat flakes is presented in Chapter 3. The linear viscoelastic region of oat flakes was found to be below 2% strain levels. The relaxation behavior was highly dependent on moisture content. The viscoelastic behavior of oat flakes was represented with two-element generalized Maxwell model. A decreasing trend was observed in stress relaxation coefficients, G_0, G_1 and G_2, as moisture level increased due to changes in oat structure such as alterations in secondary structure of proteins, gelatinization mechanism of starch molecules, and water holding capacity of fibers.
The effect of drying conditions on physical and viscoelastic properties of strawberries and carrots, as representative products for fruits and vegetables, was investigated (Chapters 4 and 6, respectively). For both samples, drying followed falling rate period, denoting that the water transport was limited by internal resistances, especially due to shrinkage effect during drying process. An increase in either drying temperature or drying duration resulted in lower color values, moisture content, and volumes. However, the effect of duration compared to temperature was found to be more important for carrots. The decreasing trend in color parameters can be associated to degradation of carotenoids and anthocyanins, which are responsible from the major color reflection of carrots and strawberries, respectively. The creep and stress relaxation behavior of both samples are expressed using Burger’s (R2 ≥ 0.971) and three-element Maxwell models (R2 ≥ 0.998). The frequency sweep measurements showed that both carrots and strawberries presented solid-like behavior. The findings from these experimental studies were used to solve a multiscale model to estimate the moisture and stress distribution throughout the sample during drying, and to estimate the quality attributes.
The hybrid mixture theory-based multiscale models are able to describe the physico-chemical changes and general transport mechanisms occurring within a porous food matrix. This theory can also be used to predict the quality changes in food products during processing by coupling transport equations with kinetic equations. A multiscale model using hybrid mixture theory was solved for drying of carrots and strawberries (Chapters 5 and 7). The models for carrots and strawberries were validated comparing the experimental results obtained in Chapters 4 and 6. Good agreements were obtained for moisture content, color parameters, and shrinkage. The model results clearly showed the importance of glass transition in water transport. For both samples, the drying in the vicinity of glass transition regime resulted in sharper moisture profiles, indicating non-Fickian transport. Especially the boundaries due to lower moisture content in these regions underwent glass transition during the drying process, which affected the textural properties. Similar to experimental results, it was found that higher drying temperature led to greater shrinkage and deformation throughout the samples, and a greater loss in color values and nutrient content, beta-carotene for carrots and ascorbic acid for strawberries. The developed model for drying of fruits and vegetables would allow finding optimum drying conditions for specific products.Submission published under a 24 month embargo labeled 'U of I Access', the embargo will last until 2021-05-01The student, Oguz Kaan Ozturk, accepted the attached license on 2019-01-24 at 20:17.The student, Oguz Kaan Ozturk, submitted this Dissertation for approval on 2019-01-24 at 20:26.This Dissertation was approved for publication on 2019-03-11 at 10:47.DSpace SAF Submission Ingestion Package generated from Vireo submission #13368 on 2019-08-22 at 15:03:58Made available in DSpace on 2019-08-23T20:28:04Z (GMT). No. of bitstreams: 5
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Relating structural properties to saltiness perception of model lipoproteic gels
No full textSodium reduction in processed foods is an urgent mission to tackle sodium overconsumption. Eighty-nine percent of US adults consume more than the recommended amount of sodium, leading to the high prevalence of hypertension. Lipoproteic foods including cheese and processed meats are potential targets for sodium reduction, as they form the major source of sodium in modern diets. Structural engineering to enhance sodium release and saltiness perception is promising for sodium reduction in lipoproteic foods, which release as low as only 5% of sodium during mastication.
The goal of this research is to relate structural properties, including porosity and particle size of fat, to the saltiness perception of a mode lipoproteic gel system. The outcome of this research can imply strategies for structural engineering to enhance the saltiness perception of lipoproteic foods.
Solid lipoproteic colloid (SLC), a solid matrix made of lipid and protein in the oil-in-water emulsion structure, was used as the model food in this study. The SLCs were made with varying contents of protein, fat, and NaCl. Two levels of homogenization pressure were applied to the emulsion before the heat-induced gelation to form the SLCs. The images of the SLC microstructure was captured using environmental scanning electron microscopy (ESEM), and the porosity was quantified using an image analysis of the ESEM observations. The gyration radius of fat (Rg,f) in the SLCs was quantified using ultra-small-angle X-ray scattering with a synchrotron-source. Serum release, which is the amount of liquid compressed out from the SLCs, and textural properties were measured using a texture analyzer. A conductivity meter was used to measure the in vitro sodium release during the compression of the SLCs in water by a texture analyzer. Sensory evaluations were carried out on the SLCs with 1.5% NaCl. A quantitative descriptive analysis (QDA) method was used to characterize the saltines and textural properties of the SLCs. A time-intensity (TI) method was used to evaluate the temporal saltiness perception properties of the SLCs.
The saltiness of the SLCs correlated positively with the porosity, but did not correlate with the Rg,f. The increased saltiness with increasing porosity was due to the greater serum release which enabled rapid sodium release. The lack of the effect of Rg,f on the SLC saltiness was due to the counteracting impacts of the Rg,f on the sodium release. Lowering the Rg,f led to more extensive breakdown but less serum release of the SLCs. The increased sodium release with increased sample breakdown was counteracted by the decreased sodium release due to decreased serum release.
This study revealed the structural influences focused with porosity and particle size of fat on the saltiness perception of lipoproteic model foods. The results implied the potential to enhance the saltiness of lipoproteic products with optimized porosity and particle size of fat. Future studies can aim at modulating the structure toward higher saltiness while maintaining the sensory acceptance of the lipoproteic products. Also, future evaluation of the in-mouth sodium release can provide more fundamental information in the saltiness perception of SLC foods.Submission published under a 24 month embargo labeled 'U of I Access', the embargo will last until 2018-05-01The student, Wan-Yuan Kuo, accepted the attached license on 2016-04-18 at 11:41.The student, Wan-Yuan Kuo, submitted this Dissertation for approval on 2016-04-19 at 18:12.This Dissertation was approved for publication on 2016-04-21 at 08:22.DSpace SAF Submission Ingestion Package generated from Vireo submission #9269 on 2016-07-07 at 13:49:39Made available in DSpace on 2016-07-07T20:27:31Z (GMT). No. of bitstreams: 3
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Opportunities and challenges for justice linkages : case studies from Kunduz & Takhar / author Seth Peavey.
No full textMultiscale modeling of transport mechanisms and quality changes in frozen foods during freeze-thaw cycles
No full textThe freezing process is commonly used to store and preserve foods. However, the frozen foods’ texture and taste are harmed by the temperature fluctuations during shipping and storage. The insights into the mechanisms of heat transfer, moisture migration, ice crystallization and solute diffusion are necessary to be achieved to understand the complex freezing process. The objective of this study is to develop a fundamental mathematical model complemented by the experimental measurements for describing heat, fluid, species and mechanical changes in foods subjected to freeze-thaw cycles.
From the experimental aspect, the 3D microstructure of frozen potatoes was investigated by using an innovative high-resolution internal imaging method: X-ray micro-computed tomography (CT), to study the effect of temperature fluctuations on ice crystal growth/decay during freezing. The inner structure and porous morphology showed significant growth of ice crystals with the increase in temperature fluctuations and duration of freezing. Besides, the 3D ice crystal morphology, size distribution and pore volume fraction obtained by image analysis provide useful information for a frozen biomaterial, which is difficult to be gathered from traditional experiments.
A hybrid mixture theory-based multiscale model was applied to predict phase change, fluid, species and heat transfer, crystal growth, and thermomechanical effects inside the frozen products during freezing. A solution scheme for the two-scale unsaturated transport and thermomechanical equations was developed, which can explain the fluids, species and heat transfer and describe the physical mechanisms during the freezing process. Good agreements between the predicted values and experimental data were achieved with regard to temperature profiles and freezing point depression (FPD). This work is the first study to calculate FPD in a porous food using HMT based fluid and species transport model. The simulation results show that HMT-based solute transport equation coupled with fluid and heat transfer equations and physical chemistry-based relations can provide a better prediction of the freezing point depression than the empirical equation published in the literature. Furthermore, this solution scheme is capable of identifying the freezing efficiency of air and liquid-based freezing media. The predicted results for a frozen potato in the air blast freezer indicated less ice formation and more mass loss compared to the sample in the ethylene glycol-based freezer.
The practical application of this study is the analysis of the effect of temperature fluctuations on certain quality attributes of frozen foods. Larger magnitude and longer duration of fluctuations for the ambient freezing temperature increase the gas volume fraction and result in its uneven distribution from center to surface, which indicates that the pores are enlarged and cell walls are prone to be damaged in the frozen biomaterial. In addition, the frozen potato geometry presented varying deformation for the fluctuating conditions. The sudden temperature fluctuation situations representing opening and closing of freezer door were also investigated using this solution scheme. The predicted results manifested that multiple door opening-closing conditions would show worse damage to the frozen product quality in comparison to the one with fewer fluctuations.Submission published under a 24 month embargo labeled 'U of I Access', the embargo will last until 2021-12-01The student, Ying Zhao, accepted the attached license on 2019-12-05 at 02:20.The student, Ying Zhao, submitted this Dissertation for approval on 2019-12-05 at 02:26.This Dissertation was approved for publication on 2019-12-06 at 12:26.DSpace SAF Submission Ingestion Package generated from Vireo submission #14711 on 2020-02-28 at 17:23:30Made available in DSpace on 2020-03-02T22:15:08Z (GMT). No. of bitstreams: 2
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