LABORATORY SCALE CONCEPT VALIDATION AND EVALUATION OF COMPROMISING PLANT NODAL INTEGRITY AS A MEANS TO INCREASE BALE DENSITY

Transportation costs represent a significant role in the economics of packaged hay and biomass crops. The material’s low bulk density limits transportation efficiency. Density is currently limited by the ability of the baling twine to withstand the expansion forces generated by the baled material shortly after it is ejected from the bale chamber. It was hypothesized that compromising the structure of the plant, particularly the plant nodes could reduce the amount of energy stored in the material as it is compressed and thereby reduce the material’s elastic response to compression. Literature pertinent to the biomass material’s behavior in compression was reviewed. Bulk samples of switchgrass and miscanthus were subject to uniaxial compression, and the required pressure needed to obtain a target density of 256 kg/m3 was compared on a wet and dry density basis. Both switchgrass and miscanthus showed a statistically significant decrease in the required compression pressure, and the interaction between the moisture level and required pressure was also significant. Existing models for the pressure density relationship of compressed bulk material were evaluated for suitability. Individual nodes and internode sections were subject to radial compression and the apparent modulus of elasticity and maximum contact stress were determined

DEVELOPMENT OF A DECISION SUPPORT SYSTEM FOR CAPACITY PLANNING FROM GRAIN HARVEST TO STORAGE

This dissertation investigated issues surrounding grain harvest and transportation logistics. A discrete event simulation model of grain transportation from the field to an on-farm storage facility was developed to evaluate how truck and driver resource constraints impact material flow efficiency, resource utilization, and system throughput. Harvest rate and in-field transportation were represented as a stochastic entity generation process, and service times associated with various material handling steps were represented by a combination of deterministic times and statistical distributions. The model was applied to data collected for three distinct harvest scenarios (18 total days). The observed number of deliveries was within ± 2 standard deviations of the simulation mean for 15 of the 18 input conditions examined, and on a daily basis, the median error between the simulated and observed deliveries was -4.1%. The model was expanded to simulate the whole harvest season and include temporary wet storage capacity and grain drying. Moisture content changes due to field dry down was modeled using weather data and grain equilibrium moisture content relationships and resulted in an RMSE of 0.73 pts. Dryer capacity and performance were accounted for by adjusting the specified dryer performance to the observed level of moisture removal and drying temperature. Dryer capacity was generally underpredicted, and large variations were found in the observed data. The expanded model matched the observed cumulative mass of grain delivered well and estimated the harvest would take one partial day longer than was observed. Usefulness of the model to evaluate both costs and system performance was demonstrated by conducting a sensitivity analysis and examining system changes for a hypothetical operation. A dry year and a slow drying crop had the largest impact on the system’s operating and drying costs (12.7% decrease and 10.8% increase, respectively). The impact of reducing the drying temperature to maintain quality in drying white corn had no impact on the combined drying and operating cost, but harvest took six days longer. The reduced drying capacity at lower temperatures resulted in more field drying which counteracted the reduced drying efficiency and increased field time. The sensitivity analysis demonstrated varied benefits of increased drying and transportation capacity based on how often these systems created a bottleneck in the operation. For some combinations of longer transportation times and higher harvest rates, increasing hauling and drying capacity could shorten the harvest window by a week or more at an increase in costs of less than $12 ha-1. An additional field study was conducted to examine corn harvest losses in Kentucky. Total losses for cooperator combines were found to be between 0.8%-2.4% of total yield (86 to 222 kg ha-1). On average, the combine head accounted for 66% of the measured losses, and the total losses were highly variable, with coefficients of variation ranging from 21.7% to 77.2%. Yield and harvest losses were monitored in a single field as the grain dried from 33.9% to 14.6%. There was no significant difference in the potential yield at any moisture level, and the observed yield and losses displayed little variation for moisture levels from 33.9% to 19.8%, with total losses less than 1% (82 to 130 kg dry matter ha-1). Large amounts of lodging occurred while the grain dried from 19.8% to 14.6%, which resulted in an 18.9% reduction in yield, and harvest losses in excess of 9%. Allowing the grain to field dry generally improved test weight and reduced mechanical damage, however, there was a trend of increased mold and other damage in prolonged field drying

My problem or our problem? Exploring the use of information sharing as a component of a holistic approach to e-security in response to the growth of ‘malicious targeted attacks’

There is now a growing recognition amongst e-security specialists that the e-security environment faced by organisations is changing rapidly. This environment now sees a situation where maliciously targeted attacks are conducted by ‘guns for hire’ (hackers) and/or criminal organisations (Illett 2005; Keiser 2005). As a consequence, conventional organisational approaches to e-security are becoming increasingly problematic and inadequate. There is a need to raise awareness of these issues amongst organisations and to contribute to the generation of effective integrated solutions that address this emerging e-security environment without sacrificing user privacy and/or breaching user trust. This paper considers the potential role of e-security information sharing between organisations as a key element in the development of the integrated responses advocated. By examining information sharing in other areas of business it is evident that there are mechanisms that can facilitate these behaviours and generate benefits for organisations. Despite this growing evidence however, there remains reluctance amongst most organisations to engage in e-security related information sharing (Gross 2005). In examining these issues this paper considers mechanisms for generating stronger evidence on the role and effectiveness of e-security information sharing and ways of overcoming organisational reluctance to implement them

Cyber Vulnerabilities and the Tourism Industry: Developing a Conceptual Framework

In the post 9/11 era tourism remains a growing global industry worth an estimated $2bn/day. In response to the physical threat of terrorism, governments and industry have been very active in implementing changes. However, it is noticeable as the industry becomes increasingly reliant on the Internet and other information technologies how little discussion there has been of the potential threats from cyber vulnerabilities. As research in the e-security and e-forensics domains highlights there has been a marked increase in the sophistication and targeting of cyber attacks that has the potential to threaten individual firms, destination brands or the industry as a whole. In an effort to explore these potential vulnerabilities, examine their impacts and consider meaningful responses, this research-in-progress paper outlines a developing conceptual framework for investigating these issues in a coherent manner. This framework forms the basis for ongoing research into cyber vulnerabilities in the Tasmanian tourist industr

On shocks driven by high-mass planets in radiatively inefficient disks. I. Two-dimensional global disk simulations

Recent observations of gaps and non-axisymmetric features in the dust distributions of transition disks have been interpreted as evidence of embedded massive protoplanets. However, comparing the predictions of planet-disk interaction models to the observed features has shown far from perfect agreement. This may be due to the strong approximations used for the predictions. For example, spiral arm fitting typically uses results that are based on low-mass planets in an isothermal gas. In this work, we describe two-dimensional, global, hydrodynamical simulations of disks with embedded protoplanets, with and without the assumption of local isothermality, for a range of planet-to-star mass ratios 1-10 M_jup for a 1 M_sun star. We use the Pencil Code in polar coordinates for our models. We find that the inner and outer spiral wakes of massive protoplanets (M>5 M_jup) produce significant shock heating that can trigger buoyant instabilities. These drive sustained turbulence throughout the disk when they occur. The strength of this effect depends strongly on the mass of the planet and the thermal relaxation timescale; for a 10 M_jup planet embedded in a thin, purely adiabatic disk, the spirals, gaps, and vortices typically associated with planet-disk interactions are disrupted. We find that the effect is only weakly dependent on the initial radial temperature profile. The spirals that form in disks heated by the effects we have described may fit the spiral structures observed in transition disks better than the spirals predicted by linear isothermal theory.Comment: 10 pages, 8 figures. ApJ, accepte

Prospectus, September 7, 2000

https://spark.parkland.edu/prospectus_2000/1021/thumbnail.jp

An Integrative Review on the Research on the Impact of Teacher Inquiry on Student Achievement

This review investigated the impact of teacher inquiry on student achievement and identified characteristics of effective inquiry.  We first explore the theoretical underpinning inquiry research and then discuss studies that demonstrated an association between an inquiry and student achievement shifts. Effective teacher inquiries had a focus on student achievement, sufficient time, teacher engagement and collaboration, external expertise, and leaders’ support. When the aspects above were present, the potential for the intervention to demonstrate positive shifts in student achievement increased. Barriers to effective inquiry are also suggested. The review concludes with implications and recommendations for future research studies

Prospectus, September 20, 2000

https://spark.parkland.edu/prospectus_2000/1023/thumbnail.jp