Heat and Mass Transfer in Parboiled Rice during Heating with 915 MHz Microwave Energy and Impacts on Milled Rice Properties

Microwave (MW) heating offers an energy-efficient, fast method to dry high moisture content (MC) parboiled rice to safe storage MC. However, there is limited research that describes the fundamentals of heat and mass transport in rice kernels exposed to MW energy at 915 MHz, the most promising heating frequency for industrialized processing. This information is vital to explain the implications of MW technology on dried rice quality. The overall objective of this study was to develop a microwave heating technology that can sufficiently dry high MC parboiled rough rice kernels in one pass using a 915-MHz industrial microwave system. An industrial type MW system operating at 915 MHz frequency was used to dry high MC long-grain parboiled rough rice samples that were harvested at initial MC of 23% to 24% wet basis (w.b). Long grain rough rice samples were soaked in a lab-scale hot water bath set to soaking temperatures of 71 oC, 73 oC and 76 oC for 3 hours. After soaking, the wet rough rice was steamed in a lab-scale autoclave set to a temperature of 113 oC and a corresponding pressure value of 67 kPa for 5, 10 and 15 minutes (mins). The MW drying was accomplished at MW specific powers that ranged from 0.37 to 8.77 kW. [kg-DM]-1 (power per unit dry matter mass of the grain). During drying, fiber optic sensors were placed within the rice bed to collect real-time parboiled rough rice surface temperature. Results indicate that rough rice should be soaked at temperatures slightly below that of the onset gelatinization temperature of that rice cultivar and steamed for 10 min for optimal physiochemical and milling properties prior to drying by MW. Parboiled rough rice at initial MC of 35.88% reduced to a FMC of 13.48% after being treated with MW power level of 2 kW and drying duration of 31.5 min (MW specific energy of 3780 kJ.[kg-grain]-1) and at a low specific power of 2.92 kW.[kg-DM]-1. Increased MW specific power has a positive effect on parboiled rough rice MC reduction but negatively effects the rice milling characteristics. The head rice yield (HRY) obtained from the treatment was dependent on the specific energy input and reduced at higher specific energies. The drying rate was highest during the beginning of drying then slowed down during the end and can be divided into 2 periods, a first falling rate period (1.5 min to 7.5 min), and the second falling rate period (7.5 min to 31.5 min). Of the Page, Newton, Logarithmic, and Henderson & Pabis semi-empirical drying models, the logarithmic model best represented the MW drying behavior of parboiled rough rice kernels as determined by the R2, Adjusted R2, Reduced χ 2 and RMSE values. The effective moisture diffusivity was determined to be 5.04 × 10-11 m2.s-1. The activation energy was determined to be 3.02 kW.kg-1. The energy consumption was determined to be 1.05 kWh.[kg-grain]−1 with a drying efficiency of 18.89%. The drying cost for a ton of parboiled rough rice was $88.31 at a commercial energy rate of 8.41 cents per kWh in the state of Arkansas (2020). The models and parameters found in this study can be applied to industrial designs and act as an operational guide for the MW drying of parboiled rice

Modelling the medium- to long-term potential macroeconomic impact of Brexit on Ireland

There is almost a complete consensus in the international literature that Brexit will have a negative effect on the UK economy both in the short and long run. The UK is one of Ireland’s closest economic partners and little is known about the potential macroeconomic impact that Brexit could have on the Irish economy. In this paper, we use the new COre Structural MOdel of the Irish economy (COSMO) to attempt to quantify the medium- to long-run impact of Brexit on the Irish economy under a series of alternative scenarios. These scenarios are intended to cover a range of potential agreements between the UK and the EU. We find that the level of Irish output is permanently below what it otherwise would have been in the absence of Brexit

Linkage design effect on the reliability of surface-micromachined microengines driving a load

The reliability of microengines is a function of the design of the mechanical linkage used to connect the electrostatic actuator to the drive. The authors have completed a series of reliability stress tests on surface micromachined microengines driving an inertial load. In these experiments, the authors used microengines that had pin mechanisms with guides connecting the drive arms to the electrostatic actuators. Comparing this data to previous results using flexure linkages revealed that the pin linkage design was less reliable. The devices were stressed to failure at eight frequencies, both above and below the measured resonance frequency of the microengine. Significant amounts of wear debris were observed both around the hub and pin joint of the drive gear. Additionally, wear tracks were observed in the area where the moving shuttle rubbed against the guides of the pin linkage. At each frequency, they analyzed the statistical data yielding a lifetime (t{sub 50}) for median cycles to failure and {sigma}, the shape parameter of the distribution. A model was developed to describe the failure data based on fundamental wear mechanisms and forces exhibited in mechanical resonant systems. The comparison to the model will be discussed

Corals Pocillopora eydouxi and Porites lobata (Anthozoa: Scleractinia).

v. ill. 23 cm.QuarterlyReciprocal transplant experiments of the corals Pocillopora eydouxi Milne Edwards & Haime and Porites lobata Dana were carried out for an 18- month period from September 2004 to March 2006 between two back reef pools on Ofu Island, American Samoa, to test environmental versus genetic effects on skeletal growth rates. Skeletal growth of P. eydouxi showed environmental but not genetic effects, resulting in doubling of growth in Pool 300 compared with Pool 400. There were no environmental or genetic effects on skeletal growth of P. lobata. Pool 300 had more frequent and longer durations of elevated seawater temperatures than Pool 400, characteristics likely to decrease rather than increase skeletal growth. Pool 300 also had higher nutrient levels and flow velocities than Pool 400, characteristics that may increase skeletal growth. However, higher nutrient levels would be expected to increase skeletal growth in both species, but there was no difference between the pools in P. lobata growth. P. eydouxi is much more common in high-energy environments than P. lobata; thus the higher flow velocities in Pool 300 than in Pool 400 may have positively affected skeletal growth of P. eydouxi while not having a detectable effect on P. lobata. The greater skeletal growth of P. eydouxi in Pool 300 occurred despite the presence of clade D zooxanthellae in several source colonies in Pool 300, a genotype known to result in greater heat resistance but slower skeletal growth. Increased skeletal growth rates in higher water motion may provide P. eydouxi a competitive advantage in shallow, high-energy environments where competition for space is intense

Colour analysis and verification of CCTV images under different lighting conditions

Colour information is not faithfully maintained by a CCTV imaging chain. Since colour can play an important role in identifying objects it is beneficial to be able to account accurately for changes to colour introduced by components in the chain. With this information it will be possible for law enforcement agencies and others to work back along the imaging chain to extract accurate colour information from CCTV recordings. A typical CCTV system has an imaging chain that may consist of scene, camera, compression, recording media and display. The response of each of these stages to colour scene information was characterised by measuring its response to a known input. The main variables that affect colour within a scene are illumination and the colour, orientation and texture of objects. The effects of illumination on the appearance of colour of a variety of test targets were tested using laboratory-based lighting, street lighting, car headlights and artificial daylight. A range of typical cameras used in CCTV applications, common compression schemes and representative displays were also characterised

Uptake of gases in bundles of carbon nanotubes

Model calculations are presented which predict whether or not an arbitrary gas experiences significant absorption within carbon nanotubes and/or bundles of nanotubes. The potentials used in these calculations assume a conventional form, based on a sum of two-body interactions with individual carbon atoms; the latter employ energy and distance parameters which are derived from empirical combining rules. The results confirm intuitive expectation that small atoms and molecules are absorbed within both the interstitial channels and the tubes, while large atoms and molecules are absorbed almost exclusively within the tubes.Comment: 9 pages, 12 figures, submitted to PRB Newer version (8MAR2K). There was an error in the old one (23JAN2K). Please download thi

Electromagnetic-field quantization and spontaneous decay in left-handed media

We present a quantization scheme for the electromagnetic field interacting with atomic systems in the presence of dispersing and absorbing magnetodielectric media, including left-handed material having negative real part of the refractive index. The theory is applied to the spontaneous decay of a two-level atom at the center of a spherical free-space cavity surrounded by magnetodielectric matter of overlapping band-gap zones. Results for both big and small cavities are presented, and the problem of local-field corrections within the real-cavity model is addressed.Comment: 15 pages, 5 figures, RevTe

Identity and integration of Russian speakers in the Baltic states: a framework for analysis

Following a review of current scholarship on identity and integration patterns of Russian speakers in the Baltic states, this article proposes an analytical framework to help understand current trends. Rogers Brubaker's widely employed triadic nexus is expanded to demonstrate why a form of Russian-speaking identity has been emerging, but has failed to become fully consolidated, and why significant integration has occurred structurally but not identificationally. By enumerating the subfields of political, economic, and cultural ‘stances’ and ‘representations’ the model helps to understand the complicated integration processes of minority groups that possess complex relationships with ‘external homelands’, ‘nationalizing states’ and ‘international organizations’. Ultimately, it is argued that socio-economic factors largely reduce the capacity for a consolidated identity; political factors have a moderate tendency to reduce this capacity, whereas cultural factors generally increase the potential for a consolidated group identity

Local genomic adaptation of coral reef-associated microbiomes to gradients of natural variability and anthropogenic stressors

Holobionts are species-specific associations between macro- and microorganisms. On coral reefs, the benthic coverage of coral and algal holobionts varies due to natural and anthropogenic forcings. Different benthic macroorganisms are predicted to have specific microbiomes. In contrast, local environmental factors are predicted to select for specific metabolic pathways in microbes. To reconcile these two predictions, we hypothesized that adaptation of microbiomes to local conditions is facilitated by the horizontal transfer of genes responsible for specific metabolic capabilities. To test this hypothesis, microbial metagenomes were sequenced from 22 coral reefs at 11 Line Islands in the central Pacific that together span a wide range of biogeochemical and anthropogenic influences. Consistent with our hypothesis, the percent cover of major benthic functional groups significantly correlated with particular microbial taxa. Reefs with higher coral cover had a coral microbiome with higher abundances of Alphaproteobacteria (such as Rhodobacterales and Sphingomonadales), whereas microbiomes of algae-dominated reefs had higher abundances of Gammaproteobacteria (such as Alteromonadales, Pseudomonadales, and Vibrionales), Betaproteobacteria, and Bacteriodetes. In contrast to taxa, geography was the strongest predictor of microbial community metabolism. Microbial communities on reefs with higher nutrient availability (e.g., equatorial upwelling zones) were enriched in genes involved in nutrient-related metabolisms (e.g., nitrate and nitrite ammonification, Ton/Tol transport, etc.). On reefs further from the equator, microbes had more genes encoding chlorophyll biosynthesis and photosystems I/II. These results support the hypothesis that core microbiomes are determined by holobiont macroorganisms, and that those core taxa adapt to local conditions by selecting for advantageous metabolic genes

Origin and Evolution of Saturn's Ring System

The origin and long-term evolution of Saturn's rings is still an unsolved problem in modern planetary science. In this chapter we review the current state of our knowledge on this long-standing question for the main rings (A, Cassini Division, B, C), the F Ring, and the diffuse rings (E and G). During the Voyager era, models of evolutionary processes affecting the rings on long time scales (erosion, viscous spreading, accretion, ballistic transport, etc.) had suggested that Saturn's rings are not older than 100 My. In addition, Saturn's large system of diffuse rings has been thought to be the result of material loss from one or more of Saturn's satellites. In the Cassini era, high spatial and spectral resolution data have allowed progress to be made on some of these questions. Discoveries such as the ''propellers'' in the A ring, the shape of ring-embedded moonlets, the clumps in the F Ring, and Enceladus' plume provide new constraints on evolutionary processes in Saturn's rings. At the same time, advances in numerical simulations over the last 20 years have opened the way to realistic models of the rings's fine scale structure, and progress in our understanding of the formation of the Solar System provides a better-defined historical context in which to understand ring formation. All these elements have important implications for the origin and long-term evolution of Saturn's rings. They strengthen the idea that Saturn's rings are very dynamical and rapidly evolving, while new arguments suggest that the rings could be older than previously believed, provided that they are regularly renewed. Key evolutionary processes, timescales and possible scenarios for the rings's origin are reviewed in the light of tComment: Chapter 17 of the book ''Saturn After Cassini-Huygens'' Saturn from Cassini-Huygens, Dougherty, M.K.; Esposito, L.W.; Krimigis, S.M. (Ed.) (2009) 537-57