The relationship between a (Q,r) inventory policy and an age replacement maintenance policy.

Cost models are developed to show the relationship between inventory and maintenance policies when one component of one item of equipment is replaced in accordance with the maintenance policy and the components are stocked in accordance with the inventory policy. A (Q,r) inventory policy and failure replacement and age replacement maintenance policies are used. The necessary conditions for determining optimum values of the reorder quantity, the reorder point, and time to replacement are derived.http://archive.org/details/relationshipbetw00hearLieutenant Colonel, United States Marine CorpsApproved for public release; distribution is unlimited

Estimating long-term growth-rate changes of southern bluefin tuna (Thunnus maccoyii) from two periods of tag-return data

Southern bluefin tuna (SBT) (Thunnus maccoyii) growth rates are estimated from tag-return data associated with two time periods, the 1960s and 1980s. The traditional von Bertalanffy growth model (VBG) and a two-phase VBG model were fitted to the data by maximum likelihood. The traditional VBG model did not provide an adequate representation of growth in SBT, and the two-phase VBG yielded a significantly better fit. The results indicated that significant change occurs in the pattern of growth in relation to a VBG curve during the juvenile stages of the SBT life cycle, which may be related to the transition from a tightly schooling fish that spends substantial time in near and surface shore waters to one that is found primarily in more offshore and deeper waters. The results suggest that more complex growth models should be considered for other tunas and for other species that show a marked change in habitat use with age. The likelihood surface for the two-phase VBG model was found to be bimodal and some implications of this are investigated. Significant and substantial differences were found in the growth for fish spawned in the 1960s and in the 1980s, such that after age four there is a difference of about one year in the expected age of a fish of similar length which persists over the size range for which meaningful recapture data are available. This difference may be a density-dependent response as a consequence of the marked reduction in the SBT population. Given the key role that estimates of growth have in most stock assessments, the results indicate that there is a need both for the regular monitoring of growth rates and for provisions for changes in growth over time (possibly related to changes in abundance) in the stock assessment models used for SBT and other species

Concept design of a fast sail assisted feeder container ship

An environmentally sustainable fast sail-assisted feeder-container ship concept, with a maximum speed of 25 knots, has been developed for the 2020 South East Asian and Caribbean container markets. The use of low-carbon and zero-sulphur fuel (liquefied natural gas) and improvements in operational efficiency (cargo handling and scheduling) mean predicted Green house gas emissions should fall by 42% and 40% in the two selected operational regions. The adoption of a Multi-wing sail system reduces power requirement by up to 6% at the lower ship speed of 15 knots. The predicted daily cost savings are respectively 27% and 33% in South East Asian and the Caribbean regions.Two hull forms with a cargo capacity of 1270TEU utilising different propulsion combinations were initially developed to meet operational requirements. Analysis & tank testing of different hydrodynamic phenomena has enabled identification of efficiency gains for each design. The final propulsion chosen is a contra-rotating podded drive arrangement. Wind tunnel testing improved Multi-wing sail performance by investigating wing spacing, wing stagger and sail-container interactions. The associated lift coefficient was increased by 32%. Whilst savings in sail-assisted power requirement are lower than initially predicted an unexpected identified benefit was motion damping.The fast feeder-container ship is a proposed as a viable future method of container transhipment

High resolution regional seismic attenuation tomography in eastern Tibetan Plateau and adjacent regions

The Q of regional seismic phases Lg and Pg within the crust is assumed as a proxy for crustal Qβ and Qα, which is used as a constraint of crustal rheology. We measure regional‐phase Q of the eastern Tibetan Plateau and adjacent areas. This method eliminates contributions from source and site responses and is an improvement on the Two‐Station Method (TSM). We have generated tomographic images of crustal attenuation anomalies with resolution as high as 1°. In general we observe low Q in the northernmost portions of the Tibetan Plateau and high Q in the more tectonically stable regions such as the interior of the Qaidam basin. The calculated site responses appear to correlate with topography or sediment thickness. Furthermore the relationship between earthquake magnitudes and calculated source terms suggest that the RTM method effectively removes the source response and may be used as an alternative to source magnitude

Lateral velocity variations in southern California. I. Results for the upper crust from Pg waves

The plate boundary and major crustal blocks in southern California are imaged by a tomographic backprojection of the Pg first arrivals recorded by the Southern California Array. The method, formulated specifically for local earthquake arrival times, is a fast, iterative alternative to direct least-squares techniques. With it, we solve the combined problem of determining refractor velocity perturbations and source and station delays. Resolution and variance are found empirically by using synthetic examples. A map showing lateral velocity variations at a depth of approximately 10 km is presented. The results show a strong correlation with surface tectonic features. Clear velocity contrasts exist across the San Andreas, the San Jacinto, and the Garlock faults. The Mojave region has the slowest velocities while the Peninsula Ranges have the highest. The San Jacinto block has velocities intermediate between Mojave and Peninsula Range velocities, and also has early station delays. This may indicate that the San Jacinto block has overridden Mojave material on a shallow detachment surface. No velocity variations are found associated with the Transverse Ranges, which we interpret to mean that the surface batholithic rocks in this area do not extend to Pg depths

Australian covert bullying prevalence study

The safety of members of the school community is essential to enhance the academic, social development and well being of young people. In line with the United Nations\u27 Convention on the Rights of the Child, the National Safe Schools Framework (NSSF) is regarded as.a highly innovative, collaborative effort on behalf of the Commonwealth, State and Territory Governments to foster the development and implementation of a series of whole-of-school initiatives to produce an integrated national policy for the prevention and early intervention of bullying and other aggressive and violent behaviours. Yet despite the impact of the NSSF in terms of reducing direct, face-to-face \u27overt\u27 bullying, such as hitting, punching, kicking and teasing, evidence suggests that a less direct form of \u27covert\u27 bullying is becoming more prevalent and insidious, fuelled in part by the growth of new forms of Information and Communications Technology (ICT). From this perspective, the Australian Covert Bullying Prevalence Study (ACBPS), commissioned by the Department of Education, Employment and Workplace Relations (DEEWR), represents a significant first step to understand and tackle this phenomenon

Chemical-Equilibrium Analysis with Adjoint Derivatives for Propulsion Cycle Analysis

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/143118/1/1.B36215.pd

Preparing Priests to Lead Parish Schools: Concerns and Recommendations

Canon law recognizes the pastor as the chief educational officer (CEO) of the parish school. However, recent studies demonstrate that seminaries do not prepare seminarians for work in or leadership of Catholic schools, and recent scholarship also demonstrates that an increasing number of seminarians lack the desire to lead a parish school. Our research study examined the post-seminary preparation of priests for leadership of parish schools. We also explored alternative governance models for Catholic schools. We conducted structured interviews with 10 national leaders to explore these two areas of interest. Our findings demonstrate that preparation of newly ordained and veteran priests for parish school leadership is woefully inadequate. Interviewees suggested that the pastor/principal relationship and school finance are two important topics that should be addressed in best practice preparation programs for school leaders. All 10 interviewees had difficulty imagining alternative governance models for schools in which the pastor would not serve as the CEO, but at the same time, some of the participants could see potential benefits of alternative governance models. Based on the findings of our study, we recommend that: (1) seminary programs include an initial introduction to the importance of Catholic schools for evangelization; (2) a new national model for preparing young and veteran priests for school leadership be developed and implemented; (3) existing best practices for alternative governance models be collated and promulgated; and (4) church leaders and stakeholders determine the best governance models for their schools and then prepare the appropriate people for leadership roles accordingly

Thermodynamics of Gas Turbine Cycles with Analytic Derivatives in OpenMDAO

A new equilibrium thermodynamics analysis tool was built based on the CEA method using the OpenMDAO framework. The new tool provides forward and adjoint analytic derivatives for use with gradient based optimization algorithms. The new tool was validated against the original CEA code to ensure an accurate analysis and the analytic derivatives were validated against finite-difference approximations. Performance comparisons between analytic and finite difference methods showed a significant speed advantage for the analytic methods. To further test the new analysis tool, a sample optimization was performed to find the optimal air-fuel equivalence ratio, , maximizing combustion temperature for a range of different pressures. Collectively, the results demonstrate the viability of the new tool to serve as the thermodynamic backbone for future work on a full propulsion modeling tool