Food safety in the 21st century Fung, Fred; Wang, Huei-Shyong; Menon, Suresh
Biomedical Journal,
04/2018, Volume:
41, Issue:
2
Journal Article
Peer reviewed
Open access
Food is essential to life, hence food safety is a basic human right. Billons of people in the world are at risk of unsafe food. Many millions become sick while hundreds of thousand die yearly. The ...food chain starts from farm to fork/plate while challenges include microbial, chemical, personal and environmental hygiene. Historically, documented human tragedies and economic disasters due to consuming contaminated food occurred as a result of intentional or unintentional personal conduct and governmental failure to safeguard food quality and safety. While earlier incidents were mainly chemical contaminants, more recent outbreaks have been due to microbial agents. The Disability Adjusted Life Years (DALYs) attributed to these agents are most devastating to children younger than 5 years of age, the elderly and the sick. To ensure food safety and to prevent unnecessary foodborne illnesses, rapid and accurate detection of pathogenic agents is essential. Culture-based tests are being substituted by faster and sensitive culture independent diagnostics including antigen-based assays and polymerase chain reaction (PCR) panels. Innovative technology such as Nuclear Magnetic Resonance (NMR) coupled with nanoparticles can detect multiple target microbial pathogens' DNA or proteins using nucleic acids, antibodies and other biomarkers assays analysis. The food producers, distributors, handlers and vendors bear primary responsibility while consumers must remain vigilant and literate. Government agencies must enforce food safety laws to safeguard public and individual health. Medical providers must remain passionate to prevent foodborne illnesses and may consider treating diseases with safe diet therapy under proper medical supervision. The intimate collaboration between all the stakeholders will ultimately ensure food safety in the 21st century.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Large-eddy simulation (LES) of a liquid-fueled lean-direct injection (LDI) combustor is carried out by resolving the entire inlet flow path through the swirl vanes and the combustor. A localized ...dynamic subgrid closure is combined with a subgrid mixing and combustion model so that no adjustable parameters are required. The inflow spray is specified by a Kelvin–Helmholtz (or aerodynamic) breakup model and compared with LES without breakup, where the incoming spray is approximated using measured data just downstream of the injector. Overall, both time-averaged gas and droplet velocity predictions compare well with the measured data. The major impact of breakup is on fuel evaporation in the vicinity of the injector. Further downstream, a broad spectrum of drop sizes are recovered by the breakup simulation and produces spray quality, as in the no-breakup case. It is shown that the vortex breakdown bubble (VBB) is smaller with more intense reverse flow when there is heat release. The swirling shear layer plays a major role in spray dispersion and the VBB provides an efficient flame-holding mechanism to stabilize the flame. Unsteady features such as the efficient dispersion of the spray by the precessing vortex core (PVC) are well captured. Flame structure analysis using the Takeno flame index shows the presence of a diffusion flame in the central portion, whereas premixed burning mode is observed farther away. Instantaneous thermochemical states of fuel–air mixing and oxidation indicate significant departure from the gaseous diffusion limits, consistent with earlier observations. Additionally, particle–particle and particle–gas correlations are analyzed and discussed.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Ignition and relighting in supersonic flows is an important challenge for the design of hypersonic propulsion systems. Supersonic compressible flows of interest exhibit much larger local variations ...in velocity, shear, and thermodynamic state than their incompressible counterparts. Thus, it is of interest to study the relationship between ignition kernel evolution, the initial spark location, and the kernel’s subsequent flow state history. We leverage the flexibility of a laser plasma ignition system to systematically explore a large set of spark locations on the symmetry plane of an ethylene jet in supersonic crossflow setup. CH* measurements are used to visualize chemically active regions and results are correlated with flow field properties derived from Mie-scattering data of the non-reacting flow field. Our study describes the laser plasma properties in detail and scrutinizes the effect of turbulent mixing and flow dilatation on ignition kernels. Finally, the results yield general guidelines for favorable ignition locations in the engineering design of chemically reactive compressible flows.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
A large eddy simulation (LES) sub-grid model is developed based on the artificial neural network (ANN) approach to calculate the species instantaneous reaction rates for multi-step, multi-species ...chemical kinetics mechanisms. The proposed methodology depends on training the ANNs off-line on a thermo-chemical database representative of the actual composition and turbulence (but not the actual geometrical problem) of interest, and later using them to replace the stiff ODE solver (direct integration (DI)) to calculate the reaction rates in the sub-grid. The thermo-chemical database is tabulated with respect to the thermodynamic state vector without any reduction in the number of state variables. The thermo-chemistry is evolved by stand-alone linear eddy mixing (LEM) model simulations under both premixed and non-premixed conditions, where the
unsteady interaction of turbulence with chemical kinetics is included as a part of the training database. The proposed methodology is tested in LES and in stand-alone LEM studies of three distinct test cases with different reduced mechanisms and conditions. LES of premixed flame–turbulence–vortex interaction provides direct comparison of the proposed ANN method against DI and ANNs trained on thermo-chemical database created using another type of tabulation method. It is shown that the ANN trained on the LEM database can capture the correct flame physics with accuracy comparable to DI, which cannot be achieved by ANN trained on a laminar premix flame database.
A priori evaluation of the ANN generality within and outside its training domain is carried out using stand-alone LEM simulations as well. Results in general are satisfactory, and it is shown that the ANN provides considerable amount of memory saving and speed-up with reasonable and reliable accuracy. The speed-up is strongly affected by the stiffness of the reduced mechanism used for the computations, whereas the memory saving is considerable regardless.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Condylar hyperplasia is a rare pathology characterised by excessive bone growth that presents virtually unilaterally, resulting in facial asymmetry. The aetiology of this disorder is not well ...understood. This pathology has been reported to be a rare entity with very few cases being reported in the literature, mostly seen between 11 and 30 years of age, with males and females being equally affected and having no predominance to the left or right side. It has also been reported to be a self-limiting condition, that is, the active growth can cease at any point in time. We report two cases of unilateral condylar hyperplasia in 24- and 19-year-old male and female patients, where the first was treated by condylectomy and BSSO, and the latter was treated by high condylectomy and recontouring of the mandible.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
6.
Use of Buccal Fat Pad for Treatment of Oral Submucous Fibrosis Sharma, Rohit, MDS; Thapliyal, G.K., MDS, FIBOMS; Sinha, Ramen, MDS, FIBOMS ...
Journal of oral and maxillofacial surgery,
2012, 2012-Jan, 2012-1-00, 20120101, Volume:
70, Issue:
1
Journal Article
Peer reviewed
Purpose The aim of this study was to clinically evaluate the application of pedicled buccal fat pad (BFP) in the surgical management of stage III and IV oral submucous fibrosis (OSMF). Materials and ...Methods Twenty-eight cases of clinically and histologically diagnosed cases of OSMF were divided into 2 groups: group I (n = 15) and group II (n = 13), corresponding to clinical stage III and stage IV, respectively. All the patients underwent incision of fibrotic bands and coverage of the buccal defect with a pedicled BFP flap. Both groups were analyzed separately for mouth opening (interincisal distance in millimeters) preoperatively and 1 year postoperatively, time taken for epithelialization of BFP, time taken for establishment of normal contour, and changes in symptoms (painful ulcerations, burning sensation, and intolerance to spices) 1 year after grafting. Results The mean preoperative mouth opening was 19.6 mm (SD, 2.43) in group I and 12.92 mm (SD, 1.21) in group II. The mean postoperative mouth opening after 1 year was 35 mm in group I (SD, 1.96) and 31.76 mm in group II (SD, 1.97). The time taken for epithelialization of BFP was 4 weeks in group I and 5 weeks in group II. The mean time taken for establishment of normal contour after grafting was 12.25 weeks (SD, 1.42) in group I and 15.07 weeks (SD, 1.26) in group II. In 2 cases in group II, there was remission of painful ulcerations, burning sensation, and intolerance to spices. Conclusion BFP is reliable for the treatment of OSMF.
•A hybrid EE-EL method for dense-to-dilute flows is developed from first principles.•The method asymptotes to well-established EE and EL in limiting conditions.•Smooth and dynamic transition to use ...EE/EL in respective regions of effectiveness.•Validated across a range of volume-fractions and Stokes numbers.
Problems involving a transition between dense and dilute dispersed phase regimes often require hybridization of Eulerian-Eulerian (EE) and Eulerian-Lagrangian (EL) methods for accurate and efficient computational modeling. A hybrid EE-EL formulation is developed in this work from first principles, which asymptotes to well-established EE and EL methods in limiting conditions. A smooth and dynamic transition criterion and a corresponding algorithm for conversion between the two representations of the dispersed phase are developed. To use EE and EL in their respective regions of effectiveness, the transition criterion is designed as a function of local volume fraction and local kinetic energy of random uncorrelated motion of particles. Several one-dimensional numerical tests are conducted to analyze limits of the hybrid EE-EL method in dense (up to 65% volume loading) and dilute conditions, at first, without any conversion between EE and EL, and then the ability of the conversion algorithm to smoothly transition from EE to EL and vice versa is evaluated using prespecified and dynamically computed transition criteria for one- and two-dimensional tests. Particle evolution in two-dimensional frozen turbulence is simulated to evaluate the method's ability to dynamically transition from EE to EL and vice versa in regions of particle trajectory crossing. Finally, the hybrid method is used for simulating dispersion of an initially dense particle cloud in a three-dimensional spherical sector blast.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
A 43-year-old Portuguese woman from the Azores developed intermittent twisting of her head to the left side associated with some rotation and discomfort (video 1 on the Neurology(R) Web site at ...Neurology.org). Movements were relieved by maneuvers such as supporting the back of her neck with her hands. Medical history was positive for a cesarean section, uterine prolapse surgery, and thyroidectomy that was complicated by right vocal cord paralysis. There was no history of any medication use known to cause dystonia.
Understanding combustion and flame stabilization of alternate fuels is necessary to establish their use in mainstream aviation. An Eulerian-Lagrangian (EL) large eddy simulation (LES) study is ...conducted using a fully compressible solver for a Referee Rig combustor, developed within the National Jet Fuel Combustion Program, (NJFCP). The Referee Rig contains multiple swirlers, dilution jets, and effusion holes, mimicking the complex flow-field in a real gas turbine combustor. Conditions as in the experiments for near blowout (NBO) operation are simulated for two fuels identified by NJFCP: a baseline fuel (A2) and an alternate fuel (C1). Time-averaged LES results are shown to provide a reasonable match against the experimental droplet statistics and OH* chemiluminescence data for both the fuels. Several post-processing tools, such as, conditional averaging, flame index, chemically explosive mode analysis (CEMA) are used to understand flame stabilization mechanism and burning behavior under NBO condition. Flame anchor point is shown to be premixed, but most heat release results from fuel pockets burning in the shear layer in a non-premixed manner. Pressure signatures at various locations and other time-varying properties show fuel-sensitive effects, even though the time-averaged behavior is similar between A2 and C1. When compared to A2, C1 shows a higher premixed burning and it is shown to be dependent on the slower burning behavior of C1 at NBO.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
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