A study of nozzle and ejector flow problems by the method of integral relations

The application of the method of integral relations to nozzle and ejector flow problems was examined. For nozzle flow problems, the general formulation is that the approaching flow may be rotational. Particular attention was given to the phenomenon of choking under nonuniform flow conditions. Numerical integration of the governing ordinary differential equations was also investigated. This scheme of analysis was also applied to study the interacting flow field within an ejector system

Prediction of light aircraft interior noise

A computerized interior noise prediction method for light aircraft is described. An existing analytical program, development for commercial jets, forms the basis of some modal analysis work which is described. The accuracy of this modal analysis technique for predicting low-frequency coupled acoustic-structural natural frequencies is discussed along with trends indicating the effects of varying parameters such as fuselage length and diameter, structural stiffness, and interior acoustic absorption

Measuring the growth rate of structure with Type IA Supernovae from LSST

We investigate measuring the peculiar motions of galaxies up to $z=0.5$ using Type Ia supernovae (SNe Ia) from LSST, and predict the subsequent constraints on the growth rate of structure. We consider two cases. Our first is based on measurements of the volumetric SNe Ia rate and assumes we can obtain spectroscopic redshifts and light curves for varying fractions of objects that are detected pre-peak luminosity by LSST (some of which may be obtained by LSST itself and others which would require additional follow-up). We find that these measurements could produce growth rate constraints at $z<0.5$ that significantly outperform those using Redshift Space Distortions (RSD) with DESI or 4MOST, even though there are $\sim4\times$ fewer objects. For our second case, we use semi-analytic simulations and a prescription for the SNe Ia rate as a function of stellar mass and star formation rate to predict the number of LSST SNe IA whose host redshifts may already have been obtained with the Taipan+WALLABY surveys, or with a future multi-object spectroscopic survey. We find $\sim 18,000$ and $\sim 160,000$ SN Ia with host redshifts for these cases respectively. Whilst this is only a fraction of the total LSST-detected SNe Ia, they could be used to significantly augment and improve the growth rate constraints compared to only RSD. Ultimately, we find that combining LSST SNe Ia with large numbers of galaxy redshifts will provide the most powerful probe of large scale gravity in the $z<0.5$ regime over the coming decades.Comment: 12 pages, 1 table, 5 figures. Accepted for publication in ApJ. The Fisher matrix forecast code used in this paper can be found at: https://github.com/CullanHowlett/PV_fisher. Updated to fix error in Eq. 1 (thanks to Eric Linder for pointing this out

A nod in the wrong direction : Does nonverbal feedback affect eyewitness confidence in interviews?

Eyewitnesses can be influenced by an interviewer's behaviour and report information with inflated confidence as a result. Previous research has shown that positive feedback administered verbally can affect the confidence attributed to testimony, but the effect of non-verbal influence in interviews has been given little attention. This study investigated whether positive or negative non-verbal feedback could affect the confidence witnesses attribute to their responses. Participants witnessed staged CCTV footage of a crime scene and answered 20 questions in a structured interview, during which they were given either positive feedback (a head nod), negative feedback (a head shake) or no feedback. Those presented with positive non-verbal feedback reported inflated confidence compared with those presented with negative non-verbal feedback regardless of accuracy, and this effect was most apparent when participants reported awareness of the feedback. These results provide further insight into the effects of interviewer behaviour in investigative interviewsPeer reviewedFinal Accepted Versio

Putative multiple alleles at the vegetative (heterokaryon) incompatibility loci het-c and het-8 in Neurospora crassa

It has never been determined in Neurospora whether multiple alleles exist at individual het loci such that interaction between any two unlike alleles will result in an incompatibility reaction. The evidence summarized here from recombination genetics and from sampling natural populations suggests multiple allelism at two of the best studied het loci. However, an alternate explanation is not excluded that invokes linked multiple loci rather than multiple alleles

Anodising AA5083 aluminium alloy using ionic liquids

Aluminium, as the current collector in lithium batteries, has shown reduced corrosion susceptibility in room temperature molten salts (1, 2). Moreover, previous studies have established that corrosion mitigation is achieved on magnesium alloys using ionic liquids pretreatments (3, 4). This paper investigated the anodisation of AA5083 aluminium alloy in Trihexyl(tetradecyl)phosphonium bis(trifluoromethylsulfony) ([P6,6,6,14][NTf2]) ionic liquid by applying a constant current followed by holding at the maximum potential for a period of time. Potentiodynamic polarisation results show that the treated surfaces were more corrosion resistant in 0.1 M sodium chloride solution compared with the control specimen. The anodising treatment was effective both in shifting the free corrosion potential to more noble values and in suppressing the corrosion current. Optical microscope and optical profilometry images indicated that an anodising film was deposited onto the alloy surface, which is thought to have inhibited corrosion in chloride environment. Further characterisation of the anodising film will be carried out in future work

Fall speed measurement and high-resolution multi-angle photography of hydrometeors in free fall

We describe here a new instrument for imaging hydrometeors in free fall. The Multi-Angle Snowflake Camera (MASC) captures high-resolution photographs of hydrometeors from three angles while simultaneously measuring their fall speed. Based on the stereoscopic photographs captured over the two months of continuous measurements obtained at a high altitude location within the Wasatch Front in Utah, we derive statistics for fall speed, hydrometeor size, shape, orientation and aspect ratio. From a selection of the photographed hydrometeors, an illustration is provided for how the instrument might be used for making improved microwave scattering calculations. Complex, aggregated snowflake shapes appear to be more strongly forward scattering, at the expense of reduced back-scatter, than heavily rimed graupel particles of similar size

A New Technique for Multidimensional Signal Compression

The problem of efficiently compressing a large number, L, of N dimensional signal vectors is considered. The approach suggested here achieves efficiencies over current pre-processing and Karhunen-Loeve techniques when both L and N are large

A preferred vision for administering secondary schools: A reflective essay

Why do you want to be a principal, Dad? asked my 10 year old the other day. I know, he continued, it\u27s because you like kids and want to help people. I guess I really never answered him, and he left for some other interest, but that started me thinking as to the real reason I was entering the arena of administration. After being a junior high English and Special Education teacher for seventeen years, why would I want to change? True, there were days when the student behaviors overshadowed the satisfaction I received by trying to teach them communication skills and the enjoyment of good literature, but there were also days, at least as many, when I was thankful that I worked with the kids rather than the adults. So why put myself in a position where I was working more directly with the adults and more indirectly with the students