Mixing of Multiple Jets with a Confined Subsonic Crossflow in a Cylindrical Duct

This paper summarizes NASA-supported experimental and computational results on the mixing of a row of jets with a confined subsonic crossflow in a cylindrical duct. The studies from which these results were derived investigated flow and geometric variations typical of the complex 3-D flowfield in the combustion chambers in gas turbine engines. The principal observations were that the momentum-flux ratio and the number of orifices were significant variables. Jet penetration was critical, and jet penetration decreased as either the number of orifices increased or the momentum-flux ratio decreased. It also appeared that jet penetration remained similar with variations in orifice size, shape, spacing, and momentum-flux ratio when the number of orifices was proportional to the square-root of the momentum-flux ratio. In the cylindrical geometry, planar variances are very sensitive to events in the near wall region, so planar averages must be considered in context with the distributions. The mass-flow ratios and orifices investigated were often very large (mass-flow ratio greater than 1 and ratio of orifice area-to-mainstream cross-sectional area up to 0.5), and the axial planes of interest were sometimes near the orifice trailing edge. Three-dimensional flow was a key part of efficient mixing and was observed for all configurations. The results shown also seem to indicate that non-reacting dimensionless scalar profiles can emulate the reacting flow equivalence ratio distribution reasonably well. The results cited suggest that further study may not necessarily lead to a universal 'rule of thumb' for mixer design for lowest emissions, because optimization will likely require an assessment for a specific application

The distribution, impact and potential management of the introdued vine Passiflora mollissima (Passifloraceae) in Hawai'i

Reports were scanned in black and white at a resolution of 600 dots per inch and were converted to text using Adobe Paper Capture Plug-in.Passiflora mollissima, a weedy vine introduced to Hawai'i, infests significant portions of two of the major islands, Hawai'i and Kaua'i. It grows between 600 and 2200 m elevation in areas where the rainfall does not exceed 5100 mm. The vine is distributed continuously over a total of 190 km² and in more widely scattered populations over an additional 330 km². Man has been the principle agent of introduction for this species. However, intermediate-distance dispersal may be affected by introduced gallincaeous birds and cattle. Locally feral pigs are the major dispersal agent. Passiflora mollissima inhabits many of the major upland vegetation types in Hawaii but is most successful in mesic Acacia koa - Metrosideros polymorpha forests. Although over much of its current range its foliage cover is less than 25%, in some areas it is so dense that it smothers large tracts of native forest. Potential impacts of the infestation on depleted and endangered endemic organisms are also discussed. It is concluded that P. mollissima has become too widespread for successful mechanical or chemical control except in are as of recent local introduction. Prospects for biological control of this species are discussed in the context of current research efforts and practical problems related to a commercially grown congener.U.S. Fish and Wildlife Service; Cooperative National Parks Reseach Studies Unit, Department of Botany, University of Hawai’i; Institute of Pacific Islands Forestry, U.S. Forest Service; Hawaii Volcanoes National Park, Resources Management Division; Hawaii Office of the Nature Conservanc

Possible Seasonality of Clostridium difficile in Retail Meat, Canada

We previously reported Clostridium difficile in 20% of retail meat in Canada, which raised concerns about potential foodborne transmissibility. Here, we studied the genetic diversity of C. difficile in retail meats, using a broad Canadian sampling infrastructure and 3 culture methods. We found 6.1% prevalence and indications of possible seasonality (highest prevalence in winter)

Precision electron flow measurements in a disk transmission line.

An analytic model for electron flow in a system driving a fixed inductive load is described and evaluated with particle in cell simulations. The simple model allows determining the impedance profile for a magnetically insulated transmission line given the minimum gap desired, and the lumped inductance inside the transition to the minimum gap. The model allows specifying the relative electron flow along the power flow direction, including cases where the fractional electron flow decreases in the power flow direction. The electrons are able to return to the cathode because they gain energy from the temporally rising magnetic field. The simulations were done with small cell size to reduce numerical heating. An experiment to compare electron flow to the simulations was done. The measured electron flow is {approx}33% of the value from the simulations. The discrepancy is assumed to be due to a reversed electric field at the cathode because of the inductive load and falling electron drift velocity in the power flow direction. The simulations constrain the cathode electric field to zero, which gives the highest possible electron flow

Building Irish families through surrogacy: medical and judicial issues for the advanced reproductive technologies

Surrogacy involves one woman (surrogate mother) carrying a child for another person/s (commissioning person/couple), based on a mutual agreement requiring the child to be handed over to the commissioning person/couple following birth. Reasons for seeking surrogacy include situations where a woman has non-functional or absent reproductive organs, or as a remedy for recurrent pregnancy loss. Additionally, surrogacy may find application in any medical context where pregnancy is contraindicated, or where a couple consisting of two males seek to become parents through oocyte donation. Gestational surrogacy is one of the main issues at the forefront of bioethics and the advanced reproductive technologies, representing an important challenge to medical law. This analysis reviews the history of surrogacy and clinical and legal issues pertaining to this branch of reproductive medicine. Interestingly, the Medical Council of Ireland does not acknowledge surrogacy in its current practice guidelines, nor is there specific legislation addressing surrogacy in Ireland at present. We therefore have developed a contract-based model for surrogacy in which, courts in Ireland may consider when confronted with a surrogacy dispute, and formulated a system to resolve any potential dispute arising from a surrogacy arrangement. While the 2005 report by the Commission on Assisted Human Reproduction (CAHR) is an expert opinion guiding the Oireachtas' development of specific legislation governing assisted human reproduction and surrogacy, our report represents independent scholarship on the contractual elements of surrogacy with particular focus on how Irish courts might decide on surrogacy matters in a modern day Ireland. This joint medico-legal collaborative also reviews the contract for services arrangement between the commissioning person/s and the surrogate, and the extent to which the contract may be enforced

Global NeuroAIDS Roundtable

In May 2012, the Division of AIDS Research at the National Institute of Mental Health (NIMH) organized the “Global NeuroAIDS Roundtable” in conjunction with the 11th International Symposium on Neurovirology and the 2012 Conference on HIV in the Nervous System. The meeting was held in New York, NY, USA and brought together NIMH-funded investigators who are currently working on projects related to the neurological complications of AIDS (NeuroAIDS) in Africa, Asia, Eastern Europe, and Latin America in order to provide an opportunity to share their recent findings and discuss the challenges encountered within each country. The major goals of the roundtable were to evaluate HIV-associated neurocognitive impairment and determine if it may be directly attributable to distinct HIV subtypes or clades and to discuss the future priorities for global NeuroAIDS research. At the “Global NeuroAIDS Roundtable”, presentations of preliminary research indicated that HIV-associated neurocognitive impairment is prevalent in all countries examined regardless of which HIV clade is present in the region. The only clear-cut difference between HIV-1 clades was in relation to subtypes A and D in Uganda. However, a key point that emerged from the discussions was that there is an urgent need to standardize neurocognitive assessment methodologies across the globe before definitive conclusions can be drawn regarding the relationship between HIV clade diversity and neuropathogenesis. Future research directions were also discussed at the roundtable with particular emphasis on the potential of viral and host factor molecular interactions to impact the pathophysiology of HIV-associated neurocognitive disorders (HAND) from a global perspective

Tradable Pollution Permits and the Regulatory Game

This paper analyzes polluters\u27 incentives to move from a traditional command and control (CAC) environmental regulatory regime to a tradable permits (TPP) regime. Existing work in environmental economics does not model how firms contest and bargain over actual regulatory implementation in CAC regimes, and therefore fail to compare TPP regimes with any CAC regime that is actually observed. This paper models CAC environmental regulation as a bargaining game over pollution entitlements. Using a reduced form model of the regulatory contest, it shows that CAC regulatory bargaining likely generates a regulatory status quo under which firms with the highest compliance costs bargain for the smallest pollution reductions, or even no reduction at all. As for a tradable permits regime, it is shown that all firms are better off under such a regime than they would be under an idealized CAC regime that set and enforced a uniform pollution standard, but permit sellers (low compliance cost firms) may actually be better off under a TPP regime with relaxed aggregate pollution levels. Most importantly, because high cost firms (or facilities) are the most weakly regulated in the equilibrium under negotiated or bargained CAC regimes, they may be net losers in a proposed move to a TPP regime. When equilibrium costs under a TPP regime are compared with equilibrium costs under a status quo CAC regime, several otherwise paradoxical aspects of firm attitudes toward TPP type reforms can be explained. In particular, the otherwise paradoxical pattern of allowances awarded under Phase II of the 1990 Clean Air Act\u27s acid rain program, a pattern tending to favor (in Phase II) cleaner, newer generating units, is explained by the fact that under the status quo regime, a kind of bargained CAC, it was the newer cleaner units that were regulated, and which therefore had higher marginal control costs than did the largely unregulated older, plants. As a normative matter, the analysis here implies that the proper baseline for evaluating TPP regimes such as those contained in the Bush Administration\u27s recent Clear Skies initiative is not idealized, but nonexistent CAC regulatory outcomes, but rather the outcomes that have resulted from the bargaining game set up by CAC laws and regulations

Protective effect of mesoporous silica particles on encapsulated folates

Mesoporous silica particles (MSPs) are considered suitable supports to design gated materials for the encapsulation of bioactive molecules. Folates are essential micronutrients which are sensitive to external agents that provoke nutritional deficiencies. Folates encapsulation in MSPs to prevent degradation and to allow their controlled delivery is a promising strategy. Nevertheless, no information exists about the protective effect of MSPs encapsulation to prevent their degradation. In this work, 5-formyltetrahydrofolate (FO) and folic acid (FA) were entrapped in MSPs functionalized with polyamines, which acted as pH-dependent molecular gates. The stability of free and entrapped vitamins after acidic pH, high temperature and light exposure was studied. The results showed the degradation of FO after high temperature and acidic pH, whereas entrapped FO displayed enhanced stability. Free FA was degraded by light, but MSPs stabilized the vitamin. The obtained results point toward the potential use of MSPs as candidates to enhance stability and to improve the bioavailability of functional biomolecules.Authors gratefully acknowledge the financial support from the Ministerio de Economia y Competitividad (Projects AGL2012-39597-C02-01, AGL2012-39597-C02-02 and MAT2012-38429-C04-01), FEDER founding and the Generalitat Valenciana (Project PROMETEOII/2014/047). M.R.R. and E.P.E. are grateful to the Ministerio de Ciencia e Innovacion for their Grants (AP2010-4369 and AP2008-0620).Ruiz Rico, M.; Daubenschüz, H.; Pérez Esteve, E.; Marcos Martínez, MD.; Amorós, P.; Martínez Mañez, R.; Barat Baviera, JM. (2016). Protective effect of mesoporous silica particles on encapsulated folates. European Journal of Pharmaceutics and Biopharmaceutics. 105:9-17. https://doi.org/10.1016/j.ejpb.2016.05.016S91710