The Role of Aluminum in the Detonation and Post‐Detonation Expansion of Selected Cast HMX‐Based Explosives

In order to improve understanding of how aluminum contributes in non‐ideal explosive mixtures, cast‐cured formulations have been analyzed in a series of cylinder tests and plate‐pushing experiments. This study describes the contribution of 15 % aluminum (median size of 3.2 μm) vs. lithium fluoride (an inert substitute for aluminum; <5 μm) in cast‐cured HMX formulations in different temporal regimes. Small cylinder tests were performed to analyze the detonation and wall velocities (1–20 μs) for these formulations. Near‐field blast effects of 58 mm diameter spherical charges were measured at 152 mm and 254 mm using steel plate acceleration. Pressure measurements at 1.52 m gave information about free‐field pressure at several milliseconds. While the observed detonation velocities for all formulations were within uncertainty, significantly higher cylinder wall velocities, plate velocities, and pressures were observed for the aluminum formulations at ≥2 μs. Additionally, hydrocode calculations were performed to determine how non‐ideal behavior affected the plate test results. Collectively, this work gives a clearer picture of how aluminum contributes to detonation on timescales from 1 μs to about 2 ms, and how the post‐detonation energy release contributes to wall velocities and blast effects. The experiments indicate that significant aluminum reactions occur after the CJ plane, and continue to contribute to expansion at late times.     

Development of a tomographic PTV

A new tomographic PTV (Tomo-PTV) was proposed, and then its performance was compared with that of tomographic PIV (Tomo-PIV). To construct the new tomographic PTV for calculation of vector fields, an affine transformation was introduced. The vectors obtained by match probability method were used as the initial data for the final vectors. Four camera-based tomographic PTV and PIV systems were constructed. By introducing a new factor called degree of reality, the real particles were easily separated from the ghost particle groups. Two flow fields, a ring vortex and an impinging jet, were measured by the constructed tomographic PTV and the conventional tomographic PIV. Eight image frames (two consecutive image frames for each camera) were used for the construction of threedimensional voxel images. The construction method used for the voxel images was MLOS-MART.     

Development of censored data-based robust design for pharmaceutical quality by design

Robust design techniques, which are based on the concept of building quality into products or processes, are increasingly popular in many manufacturing industries. In this paper, we propose a new robust design model in the context of pharmaceutical production research and development. Traditional robust design principles have often been applied to situations in which the quality characteristics of interest are typically time insensitive. In pharmaceutical manufacturing processes, time-oriented quality characteristics, such as the degradation of a drug, are often of interest. As a result, current robust design models for quality improvement which have been studied in the literature may not be effective in finding robust design solutions. To address such practical needs, this paper develops a robust design model using censored data, which is perhaps the first attempt in the robust design field. We then study estimation methods, such as the expectation–maximization algorithm and the maximum likelihood method, in the robust design context. Finally, comparative studies are discussed for model verification via a numerical example.     

Shape design of a tire contour based on approximation model

The basic purpose of a tire is to enhance vehicle performances such as driving performance, rolling resistance, durability, ride comfort, noise, wear resistance, etc. by acting as a flexible cushion. To meet the demand for increased vehicle performances, the design method of a tire has advanced. This study proposes a structural design method for tire contour by considering both the tread contour and the sidewall contour, simultaneously. Existing studies of tire contour optimization have focused on the tread contour and the sidewall, separately. Durability, maneuverability and ride comfort are performances that are commonly investigated in tire contour design. Durability, maneuverability and ride comfort can be measured by the values of the strain energy density, tension and vertical stiffness, respectively. The optimization technique using a metamodel is introduced to maximize durability while satisfying the imposed constraints of tension and ride comfort. To achieve this, the responses defined in the optimization formulation are expressed mathematically in explicit form with respect to the design variables by using the kriging surrogate model, resulting in a simple optimization problem. Then, the simulated annealing algorithm is utilized to find the global optimum.     

Experimental Verification to Estimate Ground Thermal Conductivity Using Spiral Coil Type Ground Heat Exchangers

This paper presents an experimental study on the evaluation of thermal response of a spiral coil type GHE （ground heat exchanger）. This GHE was installed on partially saturated landfill ground that was composed of silt and clay in the runway area of Incheon International airport. TRT （thermal response test） was conducted for more than 65 hours under continuous operation conditions. Ground thermal conductivity was derived based on line source theory, which has usually been found to be appropriate for line type GHEs such as U, W and 2U types. A reasonable method to derive ground thermal conductivity using the infinite line source theory for a spiral coil type GHE was introduced. Ground thermal conductivity from the TRT using spiral coil type GHE was compared with those from the analytical equivalent model of ground thermal conductivity.     

Rental Discrimination in the Multi-ethnic Metropolis: Evidence from Sydney

Investigating differential treatment in rental housing markets is important to ensure that renters are not discriminated against based on their personal characteristics. However, little Australian research has focused systematically on this question. This paper reports the results of a study that used paired tests to estimate the extent of differential treatment of Anglo, Indian, and Muslim Middle Eastern renters in the Sydney metropolitan housing market. We find statistically significant differences in treatment on several measures, including the likelihood an agent will offer an individual appointment, will provide additional information about other housing, will provide additional information about completing the application form, and will contact a prospective renter after an inspection.