Modeling of Spray Combustion under Cryogenic and High Pressure Conditions

The paper concerns both the numerical and experimental investigation of turbulent liquid oxygen/hydrogen spray combustion for elevated subcritical pressure and cryogenic inlet temperature conditions. In particular, the combustion in the single injector combustion chamber is studied where experimental data are obtained for gas phase temperature and both droplet size and velocities. The model uses an Eulerian--Lagrangian formulation for the gas and the liquid phase, respectively. Detailed models for droplet heating and vaporization in a convective flow field are employed, and detailed gas phase reactions are accounted for through use of a flamelet model for turbulent spray combustion. The results show a very good agreement between experimental and computational spray characteristics. The computed gas phase temperature lies somewhat above the experimental values which is associated with CARS single shot measurements and incomplete data for the initial conditions of the combustion process

Transported Joint Probability Density Function Modeling of Turbulent Dilute Spray Flows

A transported joint probability density function (PDF) model for turbulent spray flows is presented, where a one-point one-time statistical description of the gas-phase mixture fraction and the gas velocity is used. This approach requires the closure of the molecular mixing, which is achieved through use of the extended interaction-by-exchange-with-the-mean (IEM) model and a simplified Langevin model for the closure of the gas velocity both of which are extended through additional terms accounting for spray evaporation. These equations require the solution of the turbulent time scales and the mean pressure field through a Eulerian description. The numerical approach includes a Lagrangian Monte Carlo method for the solution of modeled joint PDF equation with a Eulerian finite-volume algorithm to determine the turbulent time scale and the mean pressure field. For the dispersed liquid phase, Lagrangian equations are used to describe the droplet heating, evaporation, and motion in the framework of a discrete droplet model. The convective droplet evaporation model is employed, and the infinite conductivity model with consideration of non-equilibrium effects based on the Langmuir-Knudsen law is used. The droplet turbulent dispersion is modeled with two different Lagrangian stochastic models. The resulting spray evolution equations are solved by a Lagrangian discrete droplet method using the point source approximation for a dilute spray. The numerical results are compared with experimental data of Gounder et al. [1], where the experimental set B of the acetone spray flows SP2 and SP6 are simulated. Comparison of numerical and experimental results includes droplet size, liquid volume flux as well as the mean and fluctuating velocities. Generally, good agreement is achieved, although the radial droplet dispersion is somewhat under-predicted by the computations. The droplet fluctuating velocities show sensitivity to the different dispersion models

Vascular phenotype in angiogenic and non-angiogenic lung non-small cell carcinomas

We have previously described a group of non-small cell lung carcinomas without morphological evidence of neo-angiogenesis. In these tumours neoplastic cells fill up the alveoli and the only vessels present appear to belong to the trapped alveolar septa. In the present study we have characterised the phenotype of the vessels present in these non-angiogenic tumours, in normal lung and in angiogenic non-small cell lung carcinomas. The vessels, identified by the expression of CD31, were scored as mature when expressing the epitope LH39 in the basal membrane and as newly formed when expressing αVβ3 on the endothelial cells and/or lacking LH39 expression. In the nine putative non-angiogenic cases examined, the vascular phenotype of all the vessels was the same as that of alveolar vessels in normal lung: LH39 positive and αVβ3 variable or negative. Instead in 104 angiogenic tumours examined, only a minority of vessels (mean 13.1%; range 0–60%) expressed LH39, while αVβ3 (in 45 cases) was strongly expressed on many vessels (mean 55.5%; range 5–90%). We conclude that in putative non-angiogenic tumours the vascular phenotype is that of normal vessels and there is no neo-angiogenesis. This type of cancer may be resistant to some anti-angiogenic therapy and different strategies need to be developed

From Sound to Significance: Exploring the Mechanisms Underlying Emotional Reactions to Music

A common approach to studying emotional reactions to music is to attempt to obtain direct links between musical surface features such as tempo and a listener’s responses. however, such an analysis ultimately fails to explain why emotions are aroused in the listener. in this article we explore an alternative approach, which aims to account for musical emotions in terms of a set of psychological mechanisms that are activated by different types of information in a musical event. this approach was tested in 4 experiments that manipulated 4 mechanisms (brain stem reflex, contagion, episodic memory, musical expectancy) by selecting existing musical pieces that featured information relevant for each mechanism. the excerpts were played to 60 listeners, who were asked to rate their felt emotions on 15 scales. skin conductance levels and facial expressions were measured, and listeners reported subjective impressions of relevance to specific mechanisms. results indicated that the target mechanism conditions evoked emotions largely as predicted by a multimechanism framework and that mostly similar effects occurred across the experiments that included different pieces of music. we conclude that a satisfactory account of musical emotions requires consideration of how musical features and responses are mediated by a range of underlying mechanisms

Intrathecal treatment of neoplastic meningitis due to breast cancer with a slow-release formulation of cytarabine

DepoCyte is a slow-release formulation of cytarabine designed for intrathecal administration. The goal of this multi-centre cohort study was to determine the safety and efficacy of DepoCyte for the intrathecal treatment of neoplastic meningitis due to breast cancer. DepoCyte 50 mg was injected once every 2 weeks for one month of induction therapy; responding patients were treated with an additional 3 months of consolidation therapy. All patients had metastatic breast cancer and a positive CSF cytology or neurologic findings characteristic of neoplastic meningitis. The median number of DepoCyte doses was 3, and 85% of patients completed the planned 1 month induction. Median follow up is currently 19 months. The primary endpoint was response, defined as conversion of the CSF cytology from positive to negative at all sites known to be positive, and the absence of neurologic progression at the time the cytologic conversion was documented. The response rate among the 43 evaluable patients was 28% (CI 95%: 14–41%); the intent-to-treat response rate was 21% (CI 95%: 12–34%). Median time to neurologic progression was 49 days (range 1–515(+)); median survival was 88 days (range 1–515(+)), and 1 year survival is projected to be 19%. The major adverse events were headache and arachnoiditis. When drug-related, these were largely of low grade, transient and reversible. Headache occurred on 11% of cycles; 90% were grade 1 or 2. Arachnoiditis occurred on 19% of cycles; 88% were grade 1 or 2. DepoCyte demonstrated activity in neoplastic meningitis due to breast cancer that is comparable to results reported with conventional intrathecal agents. However, this activity was achieved with one fourth as many intrathecal injections as typically required in conventional therapy. The every 2 week dose schedule is a major advantage for both patients and physicians. © 2001 Cancer Research Campaign http://www.bjcancer.co

Angiogenesis inhibitors in clinical development; where are we now and where are we going?

Angiogenesis is crucial for tumour growth and the formation of metastases. Various classes of angiogenesis inhibitors that are each able to inhibit one of the various steps of this complex process can be distinguished. Results from clinical studies with these agents are summarised. In general, it has been shown that most angiogenesis inhibitors can be safely administered, but that tumour regressions are rare. Combining angiogenesis inhibitors with cytotoxic chemotherapy can enhance anticancer activity. Recently, some promising data with regard to clinical efficacy have been presented. While performing clinical studies with angiogenesis inhibitors, defining biological activity is crucial, but thus far no validated techniques are available. It is conceivable that in the near future various classes of angiogenesis inhibitors will be combined in an attempt to further improve antiangiogenic and anticancer activity

Do Students See the “Selection” in Organic Evolution? A Critical Review of the Causal Structure of Student Explanations

This paper critically reviews and characterizes the student's causal-explanatory understanding; this is done as a step toward explicating the problematic of evolution education as it concerns the cognitive difficulties in understanding Darwin's theory of natural selection. The review concludes that the student's understanding is fundamentally different from Darwin's, for the student understands evolutionary change as necessary individual transformation caused by the transformative action of various physical and behavioral factors. This is in complete contrast to Darwin's (and even the Darwinian's, for that matter) understanding of evolutionary change as a change caused by accumulative selection. Hence, to understand natural selection, the student has to learn to “see” how the accumulative selection causes evolutionary change

Exploring the similarities and differences between medical assessments of competence and criminal responsibility

The medical assessments of criminal responsibility and competence to consent to treatment are performed, developed and debated in distinct domains. In this paper I try to connect these domains by exploring the similarities and differences between both assessments. In my view, in both assessments a decision-making process is evaluated in relation to the possible influence of a mental disorder on this process. I will argue that, in spite of the relevance of the differences, both practices could benefit from the recognition of this similarity. For cooperative research could be developed directed at elucidating exactly how various mental disturbances can affect decision-making processes