The Interaction of Turbine Inter-Platform Leakage Flow with the Mainstream Flow

ABSTRACT Individual nozzle guide vanes (NGVs) in modern aero engines are often cast as a single piece with integral hub and casing endwalls. When in operation there is a leakage flow through the chord-wise inter-platform gaps. An investigation into the effect of this leakage flow on turbine performance is presented. Efficiency measurements and NGV exit area traverse data from a low speed research turbine are reported. Tests show that this leakage flow can have a significant impact on turbine performance, but that below a threshold leakage fraction this penalty does not rise with increasing leakage flow rate. The effect of various seal clearances are also investigated. Results from steady-state simulations using a three-dimensional multiblock RANS solver are presented with particular emphasis paid to the physics of the mainstream/leakage interaction and the loss generation

Integrated analysis of the molecular action of Vorinostat identifies epi-sensitised targets for combination therapy

Several histone deacetylase inhibitors including Vorinostat have received FDA approval for the treatment of haematological malignancies. However, data from these trials indicate that Vorinostat has limited efficacy as a monotherapy, prompting the need for rational design of combination therapies. A number of epi-sensitised pathways, including sonic hedgehog (SHH), were identified in AML cells by integration of global patterns of histone H3 lysine 9 (H3K9) acetylation with transcriptomic analysis following Vorinostat-treatment. Direct targeting of the SHH pathway with SANT-1, following Vorinostat induced epi-sensitisation, resulted in synergistic cell death of AML cells. In addition, xenograft studies demonstrated that combination therapy induced a marked reduction in leukemic burden compared to control or single agents. Together, the data supports epi-sensitisation as a potential component of the strategy for the rational development of combination therapies in AML

The comparative analyses of selected aspects of conservation and management of Vietnam’s national parks

The national parks in Vietnam are protected areas in the national system of special-use forests created to protect natural resources and biodiversity. In order to improve the effectiveness of management of national parks, the study assesses some current aspects of conservation and management of natural resources with respect to management plans, financial sources, staff, cooperative activities, causes of limited management capacity and threats to natural resources. Out of the total of 30 national parks, six are under the responsibility of the Vietnam Administration of Forestry (VNFOREST) and 24 national parks are managed by provincial authorities. It was found that most of the national parks have updated their management plans. Financial sources of funding for national parks mainly originated from the central and provincial budgets, with an average of 51% and 76% respectively. Fifty percent of national parks spent 40–60% of their total funding on conservation activities. About 85% of national parks’ staff had academic degrees, typically in the fields of forestry, agriculture and fisheries. Biodiversity conservation was considered a priority cooperative action in national parks with scientific institutes. Major causes of a limited management capacity of national parks included human population growth and pressure associated with resources use, lack of funding, limited human and institutional capacity and land use conflict/land grab. Illegal hunting, trapping, poaching and fishing, the illegal wildlife trade, illegal logging and firewood collecting appeared to be the most serious threats to the conservation and management of natural resources. In addition to these results, significant differences were found between the VNFOREST and provincial parks in terms of financial sources, staff and the threat of illegal logging and firewood collecting. The authors’ findings offer useful information for national park planners and managers, as well as policy makers and researchers in seeking solutions for the sustainable management of natural resources in national parks

Sixty years from discovery to solution: crystal structure of bovine liver catalase form III

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/86968/1/S0907444911024486.pd

GT2006-90838 THE EFFECT OF STATOR-ROTOR HUB SEALING FLOW ON THE MAINSTREAM AERODYNAMICS OF A TURBINE

ABSTRACT An investigation into the effect of stator-rotor hub gap sealing flow on turbine performance is presented. Efficiency measurements and rotor exit area traverse data from a low speed research turbine are reported. Tests carried out over a range of sealing flow conditions show that the turbine efficiency decreases with increasing sealant flow rate but that this penalty is reduced by swirling the sealant flow. Results from time-accurate and steady-state simulations using a three-dimensional multiblock RANS solver are presented with particular emphasis paid to the mechanisms of loss production. The contributions toward entropy generation of the mixing of the sealant fluid with the mainstream flow and of the perturbed rotor secondary flows are assessed. The importance of unsteady stator wake/sealant flow interactions is also highlighted. NOMENCLATURE Variables GT2006-90838 INTRODUCTION Sealant flow is supplied to the cavity between the stator disk and the rotor disk in many of the turbines found in modern gas turbines. This flow pressurizes the wheel space and reduces the level of hot gas ingestion. A considerable amount of research has been conducted with the aim of understanding the flow in the rim seal and to develop correlations giving the sealant flow requirement to completely suppress hot gas ingestion [1-9]. Hot gas ingestion can be caused by disk pumping (the rotation of the disk induces an outflow from the wheel space and continuity results in a subsequent ingress of hot gas from the mainstream into the disk cavity) or by an external asymmetric pressure field (the potential field of the vanes and the rotor results in a localized pressure maximum which drives flow into the disk cavity). It has been found that at engine representative conditions, it is the external pressure field that dominates [1]. Recent experimental and numerical work has shown that unsteady effects play a significant role in hot gas ingestion The sealant flow supplied to avoid hot gas ingestion inevitably enters and mixes with the flow in the mainstream annulus. This flow can lead to a significant loss of efficiency This paper presents an experimental and numerical study into the effects of hub rim sealing flow on the performance of a full scale low speed model of a modern aero-engine turbine

The Blueberry Fruit Mycobiome Varies by Tissue Type and Fungicide Treatment

The microbial ecology of agricultural products may provide crucial insights into the management of postharvest fruit rots. To investigate postharvest microbial communities of highbush blueberry (Vaccinium corymbosum), five fungicide spray programs were evaluated for their influence on the mycobiome of fruit skin and within the fruit pulp. The mycobiome was characterized by sequencing amplicons of the internal transcribed spacer 1 (ITS1) region with primers ITS1f and ITS4 with the Illumina MiSeq 300bp v3 system. Two of the five programs utilized commercial biological fungicides, two utilized azoxystrobin, and one utilized a series of treatments to simulate a realistic disease management program. Fungicide applications reduced diversity of the fruit skin mycobiome (R2 = 0.409, P = 0.0001) and had a moderate impact on the pulp mycobiome (R2 = 0.233, P = 0.0001). The mycobiome of the fruit pulp was also more variable than the skin mycobiome. In comparison with the untreated controls, each fungicide treatment program had a strongly significant effect on the β diversity of the blueberry fruit skin mycobiome (R2 = 0.53 to 0.73, P = 0.0001). In the pulp, three of the five treatments had moderate but significant effects on β diversity in comparison with the control (R2 = 0.10 to 0.18, P = 0.0005 to 0.017). Most samples indicated that fungi belonging to genera Epicoccum, Papiliotrema, and Sporobolomyces were widely prevalent and abundant across treatments and tissues. Fruit pathogen Botrytis cinerea was particularly abundant in the pulp of three of the fungicide treatments. Results from this study provide a baseline for future exploration of postharvest rot pathology and provide a community context on how fungicides may alter fungal communities in agricultural systems