QCGAT mixer compound exhaust system design and static big model test report

A mixer exhaust system was designed to meet the proposed performance and exhaust jet noise goals for the AiResearch QCGAT engine. Some 0.35 scale models of the various nozzles were fabricated and aerodynamically and acoustically tested. Preliminary optimization, engine cycle matching, model test data and analysis are presented. A final mixer exhaust system is selected for optimum performance for the overall flight regime

Individual plant care in cropping systems

Individual plant care cropping systems, embodied in precision farming, may lead to new opportunities in agricultural crop management. The objective of the project was to provide high accuracy seed position mapping of a field of sugar beet. An RTK GPS was retrofitted on to a precision seeder to map the seeds as they were planted. The average error between the seed map and the actual plant map was about 32 mm to 59 mm. The results showed that the overall accuracy of the estimated plant positions is acceptable for the guidance of vehicles and implements. For subsequent individual plant care, the deviations were not, in all cases, small enough to ensure accurate individual plant targeting

Seed Mapping of Sugar Beet

Individual plant care may well become embodied in precision farming in the future and will lead to new opportunities in agricultural crop management. The objective of this project was to develop and evaluate a data logging system attached to a precision seeder to enable high accuracy seed position mapping of a field of sugar beet. A Real Time Kinematic Global Positioning System (RTK GPS), optical seed detectors and a data logging system were retrofitted on to a precision seeder to map the seeds as they were planted. The average error between the seed map and the actual plant map was about 16–43 mm depending on vehicle speed and seed spacing. The results showed that the overall accuracy of the estimated plant positions was acceptable for the guidance of vehicles and implements as well as potential individual plant treatments

The Juvenile on Probation and Reading Retardation

The fact that delinquent boys tend to read at levels below their mental age is fairly well established in the literature (3). The suggestion is strong that delinquency and reading retardation may share a mutual etiology and causal relationship. Even stronger is the suggestion that the possibility of the rehabilitation of the delinquent youth on probation may be greatly enhanced if he is treated for reading retardation (5)

Perturbed Three Vortex Dynamics

It is well known that the dynamics of three point vortices moving in an ideal fluid in the plane can be expressed in Hamiltonian form, where the resulting equations of motion are completely integrable in the sense of Liouville and Arnold. The focus of this investigation is on the persistence of regular behavior (especially periodic motion) associated to completely integrable systems for certain (admissible) kinds of Hamiltonian perturbations of the three vortex system in a plane. After a brief survey of the dynamics of the integrable planar three vortex system, it is shown that the admissible class of perturbed systems is broad enough to include three vortices in a half-plane, three coaxial slender vortex rings in three-space, and `restricted' four vortex dynamics in a plane. Included are two basic categories of results for admissible perturbations: (i) general theorems for the persistence of invariant tori and periodic orbits using Kolmogorov-Arnold-Moser and Poincare-Birkhoff type arguments; and (ii) more specific and quantitative conclusions of a classical perturbation theory nature guaranteeing the existence of periodic orbits of the perturbed system close to cycles of the unperturbed system, which occur in abundance near centers. In addition, several numerical simulations are provided to illustrate the validity of the theorems as well as indicating their limitations as manifested by transitions to chaotic dynamics.Comment: 26 pages, 9 figures, submitted to the Journal of Mathematical Physic

Changes in total lower limb support moment in middle-aged patients undergoing arthroscopic partial meniscectomy – a longitudinal observational cohort

Background Patients with a meniscal tear are frequently treated with arthroscopic partial meniscectomy (APM) which may alter the net extension moment across the entire lower limb – known as the total support moment (TSM). Purpose To investigate changes in TSM during walking in patients undergoing APM. Methods Three-dimensional motion analysis of walking was performed in individuals with meniscal tear prior to APM and 12 months after. Peak TSM, positive ankle (ASM), knee (KSM), and hip (HSM) moments at the time of peak TSM were calculated together with corresponding angular impulses. Results Patients (n = 20) were middle aged (45.9 ± 6.3 years) and the majority male (70%). At baseline a lower KSM (mean [95%CI]; 0.59 Nm/BM · HT% [− 1.93; 3.11], P = 0.048) and a trend towards lower peak TSM (0.46 Nm/BM · HT% [− 1.82; 2.78], P = 0.099) were observed for the APM leg compared with the contralateral. Pre- versus post-APM change scores indicated a relative decrease in loading of the contralateral leg for peak TSM (− 0.49 Nm/BM · HT% [− 0.96; − 0.01], P = 0.047) and a trend towards a relative increase in loading of the APM leg for peak KSM (− 0.41 Nm/BM · HT% [− 0.92; 0.09], P = 0.105). No differences were observed in angular impulse variables. Conclusions Prior to APM a strategy to unload the injured knee was manifested by reduced KSM and a tendency to a reduced peak TSM. A more equal distribution of joint moments between injured and contralateral legs was observed 12 months following APM

Chunchucmil’s Urban Population

The previous chapter established that nearly all of what we mapped at Chunchucmil was occupied at the end of the Early Classic period. This allows us to combine mapping and excavation to discuss the structure of the city at this critical time. As we explain below, settlement in and around Chunchucmil was not homogeneous. We lump this settlement into five zones each with different characteristics: (1) site center, (2) residential core, (3) residential periphery, (4) settlement fingers, and (5) hinterland. This chapter presents the characteristics (size, settlement density, kinds of occupation) of these zones and then supplies a population estimate

The TAMORA algorithm: satellite rainfall estimates over West Africa using multi-spectral SEVIRI data

A multi-spectral rainfall estimation algorithm has been developed for the Sahel region of West Africa with the purpose of producing accumulated rainfall estimates for drought monitoring and food security. Radar data were used to calibrate multi-channel SEVIRI data from MSG, and a probability of rainfall at several different rain-rates was established for each combination of SEVIRI radiances. Radar calibrations from both Europe (the SatPrecip algorithm) and Niger (TAMORA algorithm) were used. 10 day estimates were accumulated from SatPrecip and TAMORA and compared with kriged gauge data and TAMSAT satellite rainfall estimates over West Africa. SatPrecip was found to produce large overestimates for the region, probably because of its non-local calibration. TAMORA was negatively biased for areas of West Africa with relatively high rainfall, but its skill was comparable to TAMSAT for the low-rainfall region climatologically similar to its calibration area around Niamey. These results confirm the high importance of local calibration for satellite-derived rainfall estimates. As TAMORA shows no improvement in skill over TAMSAT for dekadal estimates, the extra cloud-microphysical information provided by multi-spectral data may not be useful in determining rainfall accumulations at a ten day timescale. Work is ongoing to determine whether it shows improved accuracy at shorter timescales

Factors affecting knee abduction during weight-bearing activities in individuals with anterior cruciate ligament reconstruction

Objective To investigate if muscle strength and muscle activation patterns are associated with increased knee abduction during two functional tasks, commonly used in rehabilitation for individuals with anterior cruciate ligament reconstruction (ACLR). Design Cross-sectional study. Setting Laboratory. Participants 24 women and 29 men approximately 7 months after ACLR. Main outcome measures Isometric peak torque of the trunk and lower extremity muscles were determined during maximal voluntary contractions. Trunk and lower extremity average muscle activation amplitude and peak knee abduction were evaluated during the single-leg squat (SLS) and the single-leg hop for distance (SLHD) for the injured side. Separate backward regressions were performed for men and women. Results In women, lower knee flexion and extension strength were associated with greater peak knee abduction during the SLS (B = 4.63–18.26, p ≤ 0.036); lower knee flexion strength and iliocostalis activation on the non-injured side were associated with greater peak knee abduction during the SLHD (B = 0.60–20.48, p ≤ 0.043). No associations between muscle function and peak knee abduction were found in men. Conclusions Muscle function may contribute differently to knee abduction in men and women after ACLR. This should be considered when designing rehabilitation programs to reduce knee abduction in these patients