427 research outputs found

    In situ Image Processing and Data Binning Strategy for Particle Engineering Applications

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    Crystallization control can be improved through real-time monitoring technologies. Here, a workflow is demonstrated on rapid batch cooling crystallization of L-glutamic acid. First, in situ images were generated using video microscopy sensors and analyzed, by employing a single, rapid macro code to extract particle data descriptors. A binning procedure (over time) was performed, where every data point represented the counts of particles within a specific size or shape range per 100 images. This binning method was found more informative in tracking of the populations compared to whole image averages or individual particle datapoints. This study provides a step-by-step guide towards improving mechanistic modeling, control via feedback, automation, and continuous manufacturing for Industry 4.0

    Impact Of Undocumented Immigration On US Wages

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    The movement of undocumented people across the southern border of the United States creates an environment which destroys the free market of United States labor by increasing the supply of labor and decreasing the price of labor.  The undocumented females follow up with birth on United States soil, and create an economic dilemma for local municipalities that must provide public education for those babies.  The babies become the basis within the United States for claims of citizenship activities and legalization of the original undocumented persons.  In this scenario, the Law of Supply operates to decrease the earnings of unskilled labor.  The Law of Supply also operates to decrease the possible unionization of unskilled workers, while decreasing governmental funds needed for municipal services.  The cost to municipal governments to provide education for the anchor baby generation appears to be an unending cost increase due to the unending supply of Third World undocumented individuals crossing the United States southern borders

    Advances in control of food mixing operations

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    Mixing is a ubiquitous unit operation within the food industry and employed not only to combine multiple ingredients, but also to control reactions and modify the structure of foods. Failure of the mixing process may result in poor quality, organoleptic or functional attributes of foods along with product safety concerns. The industry is increasingly adopting automation and advanced control strategies such as Process Analytical Technology. Sensors can provide both insights into the complex mechanisms of mixing along with effective control. Here we discuss some recent advances in the control of food mixing operations

    Impact of plasma jet geometry on residence times of radical species

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    Numerous electrode geometries and power supplies, both commercial and in-house, have been employed for the generation of low-temperature atmospheric plasma jets. In this work, the development and operation of a 12 jet nonthermal atmospheric plasma system is presented. The study is based on optical spectroscopy as a diagnostic method due to its nonintrusive nature. A key focus of this study was the material selection (conductive and nonconductive), with several polymers screened for the jet design leading to polyacetal as the choice material. Their results are compared with other atmospheric plasma jet systems. The results show a significant increase in residence time and the spatial homogeneity for ambient air's main species, including: OH, O I, O2, O3, N2, and N2+. Their densities are studied with respect to treatment time, distance, duty cycle, and discharge frequency, as well as the jets' carrier gas chemistries (argon and helium). For their plasma jet system, the bulk of the chemical reactions occur in the surrounding atmosphere and not in the jet nozzle, which is different from most other plasma jet systems. The electron energy distribution function, for the given chemistries, is also reporte

    Facilitating smart HACCP strategies with Process Analytical Technology

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    The critical feature to any food management system, be it safety or quality focused, is timely and accurate product and process data. The HACCP framework is one of a systematic preventive approach that addresses hazards as a means of prevention rather than finished product inspection. The PAT initiative is a framework which also aims to change product assurance from end-product testing to preventive control through timely measurements of critical product and process parameters. The continued emergence of sensitive yet affordable sensors capable of direct measurement of biological, chemical and physical risks associated with foods during production, processing or over their shelf-life undoubtedly will support a higher temporal and spatial profiling of foods

    Impact of atmospheric pressure nonequilibrium plasma discharge on polymer surface metrology

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    Due to the attraction of plasma technologies as a clean and efficient means of surface modification, significant research has gone into the physical and chemical aspects of polymer functionalization. In this study, it was shown that the use of an atmospheric plasma jet can efficiently modify the surface of polyethylene terephthalate samples and change their hydrophobic properties to more hydrophilic characteristics. The dependence on the changes with respect to time, distance, and atomic oxygen (O I) intensity were considered as factors. It was found that with closer proximity to the plasma source (without causing thermal degradation) and with increasing levels of O I, that the changes of water contact angle and surface free energy can be maximized. It was also observed that the electron energy distribution function, for a given chemistry, significantly differed with changes in distance from the jet nozzle. This shows that for this type of plasma jet system, the bulk of the chemical reactions occur in the nozzle of the jet and not in the surrounding atmosphere. Therefore, this leads to more efficient energy transfer, higher gas temperatures, and better surface activation of samples when compared to systems that produce external chemical reactions due to more diffusion in the surrounding atmosphere and loss of reactive species to other atoms and molecules that are present

    In-Package Atmospheric Pressure Cold Plasma Treatment of Cherry Tomatoes

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    Cold plasma is increasingly under research for decontamination of foods, especially fresh fruits and vegetables. The effect of cold plasma on food quality, however, remains under researched. This study investigates the effects of cold plasma generated within a sealed package from a dielectric barrier discharge on the physical quality parameters and respiration rates of cherry tomatoes. Respiration rates and weight loss were monitored continuously, while other parameters are reported at the end of storage period. Differences among weight loss, pH and firmness for control and treated cherry tomatoes were insignificant towards the end of storage life. Changes in respiration rates and colour of tomatoes were recorded as a function of treatment, which were not drastic. The results implicate that cold plasma could be employed as a means for decontamination of cherry tomatoes while retaining product quality

    Spectroscopic study of excited molecular nitrogen generation due to interactions of metastable noble gas atoms

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    This work provides an insight into the generation of excited nitrogen species by allowing noble gases to interact both with one another and ambient air. He and Ar were utilized to generate the optimum selectivity process to create reactive nitrogen species. An optimum setting for the generation of excited molecular nitrogen species, based on their excited energy levels, was obtained when using a mixture of Ar-He at a ratio of 10:1. At that point, when a voltage of 27 kV is applied to the system, it reached the maximum efficiency for selectivity processes to occur which allowed for a greater non-radiative transfer of energy through the mixture of noble gas atoms and into the molecular nitrogen present in ambient air
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