Recycler barrier RF buckets

The Recycler Ring at Fermilab uses a barrier rf system for all of its rf manipulations. In this paper, I will give an overview of historical perspective on barrier rf systems, the longitudinal beam dynamics issues, aspects of rf linearization to produce long flat bunches and methods used for emittance measurements of the beam in the RR barrier rf buckets. Current rf manipulation schemes used for antiproton beam stacking and longitudinal momentum mining of the RR beam for the Tevatron collider operation are explained along with their importance in spectacular success of the Tevatron luminosity performance.Comment: 30 pp. Submitted as a chapter in a book on the Tevatron edited by Valeri Lebedev and Vladimir Shiltse

Simple methods for assessing groundwater resources in low permeability areas of Africa

In many areas throughout Africa, a staggering proportion of wells and boreholes fail. Failure can occur for a number of reasons – inadequate maintenance and community involvement, poor engineering or a lack of water. Often it can be difficult to work out the exact reason after the event. However, in many geological environments the impacts of poorly sited and designed boreholes and wells are a major concern to funding agencies, implementing institutions and local communities. In such areas, good supplies of groundwater cannot be found everywhere, and boreholes and wells must be sited and designed carefully to make use of the available groundwater. To appropriately site and design water sources, the groundwater resources of an area need first to be investigated to understand how water occurs in the ground. In this manual we present some techniques that allow a quick assessment of groundwater resources without requiring much expertise or expense. Some of the techniques are old and established while others are new. However, all techniques have been tested by BGS (and others) in assessing groundwater resources in Africa. This manual does not claim to be a detailed textbook for hydrogeologists – there are enough already (see reading list at the end of the chapter). Rather it is meant as a practicalaid for those involved in the practice of rural water supply, particularly in Africa. Little training or equipment is required for the tests and they can all be carried out in a short space of time. The manual is divided into six sections. The first gives an overview of the groundwater resources of sub-Saharan Africa (SSA) and discusses the scope and detail of investigations required in different geological environments. The remaining chapters describe simple techniques for assessing groundwater resources, from basic reconnaissance to assessing the yield of a borehole. In the appendix are summary sheets of the most common techniques which can be photocopied and used in the field

Preschool children's use of perceptual-motor knowledge and hierarchical representational skills for tool making

Although other animals can make simple tools, the expanded and complex material culture of humans is unprecedented in the animal kingdom. Tool making is a slow and late-developing ability in humans, and preschool children find making tools to solve problems very challenging. This difficulty in tool making might be related to the lack of familiarity with the tools and may be overcome by children's long term perceptual-motor knowledge. Thus, in this study, the effect of tool familiarity on tool making was investigated with a task in which 5-to-6-yearold children (n = 75) were asked to remove a small bucket from a vertical tube. The results show that children are better at tool making if the tool and its relation to the task are familiar to them (e.g., soda straw). Moreover, we also replicated the finding that hierarchical complexity and tool making were significantly related. Results are discussed in light of the ideomotor approach

Acquisition, retention and transfer of heavy equipment operator skills through simulator training

Initiatives and collaborations among heavy construction equipment manufacturing companies and training technology firms to develop and employ simulators for varied training purposes are becoming commonplace. However, human factors research on simulator training for operators of construction equipment is still sparse. For simulator training to be effective, it is necessary to understand how skills are learned using the simulator, how those skills are transferred to other tasks, devices, and real scenarios, and how well skills are retained after simulator training. ^ This research is on skill development, specifically as it applies to operator training for two specific types of heavy construction equipment: excavator and wheel loader. It aims at decomposing the complexity of equipment operation and distinguishing the skills to be acquired for each machine. It consists of five studies, three conducted with students at Purdue and two with expert operators at John Deere. ^ Study 1 investigated whether operation of a simulated hydraulic excavator is influenced by an intervening task performed between initial practice on the excavator and a subsequent retention test using a controls familiarization task (which involves just knowing the control functions). Two intervening tasks were inserted: practicing on a simulated loader, and reading an unrelated text intended to distract the participants. Performance on the simulator was compared against that of a group of participants who practiced on the simulated excavator throughout. The results showed no performance cost attributable to inserting practice on the simulated loader while learning the controls on the simulated excavator. The learning trends, however, prompted the question of whether the same results would bear true for learning a more complex perceptual-motor task. ^ Study 2 was intended to verify whether the alternating equipment sequence yields the same outcome for a more complex truck loading task that involves multiple operations. Besides the two experimental groups (control and loader groups) in Study 1, an additional group which was given practice on the two machines (but with a different practice schedule from the original loader group) was added to address the question of whether the duration of practice on an alternative machine affects performance on the previously learned machine. The number of sessions was also increased, from three to five, to examine the possible influence when participants continue to switch between the machines. Those participants who engaged in intervening practice on the simulated loader showed a smaller performance improvement on learning the truck loading task on the simulated excavator than did the control group who practiced on the simulated excavator for all five sessions. This outcome confirms that the controls familiarization tasks on both machines studied in the preliminary study may have been too simple for the full effects of switching between the machines to be evident. This finding of continued skill improvement upon return to the previously practiced machine inspires consideration of concurrent simulator-based training rather than the practice of learning to operate only one machine at a time. ^ Study 3 analyzed skill transfer using hierarchical task analysis (HTA) to investigate the degree of overlap in specific task components by studying the similarity and dissimilarity of the truck loading task performed in Study 2 on excavator and wheel loader simulators. After the modification and verification by operators of the initial HTAs, the finalized HTAs revealed that the lack of positive transfer found in performing the truck loading task alternately with the excavator and loader was likely due to the differences between loader and excavator in terms of the controls, physical constraints, and the explicit goals and subgoals of the task. In addition, comparing the number of levels of subgoals of HTAs did not evidence any level-of-difficulty differences between tasks. ^ Studies 4 and 5 investigated whether there is a cost when switching between different types of training modules within the same machine. Study 4 was conducted with experienced operators, who provided information on how the four selected tasks on the loader should be performed and classified the perceived difficulty level of each. Verbal protocol analysis was used to decompose the tasks of the four training modules on the loader simulator: 1) Simple Bucket Loading (B1), Filling a Trench (B2), Truck Loading (B3), and Fork Lifting (F). A nine phase, systematic method for deriving the HTAs from the think-aloud protocols was also developed in this study, which successfully generated the four HTAs. The findings show that 1) the HTA of the Fork Lifting module is significantly different than those of the three bucket loading tasks, and 2) although all three bucket loading tasks shared a similar mechanism, the operators ranked B1 as the easiest, followed by B2 and then B3 due to the corresponding accessibility of the dump targets, and fork lifting was ranked as the most difficult task. The results were used to justify the hypotheses for Study 5. ^ Study 5 sought to verify whether an alternating practice sequence within the same machine, i.e. training with an alternative tool (a wide fork) and returning to the original learned tool (a bucket) on a loader simulator, yields better skill transfer and retention (after a one-week interval). Four groups of undergraduate students were tested. Two groups were given two tasks involving bucket loading to practice in the first two sessions, whereas the other two groups were given a bucket loading task in the first session and the fork lifting task in the second session. The transfer and retention tasks both involved a bucket loading task that had not been performed in Sessions 1 and 2. The results showed that the groups who were assigned to practice on two tasks involving the manipulation of buckets performed better in the skill transfer test when the new task was introduced that also involved manipulation of the bucket. The results support thespecificity of training principle (for which the practice conditions match the test conditions and thus facilitate retention or transfer) but not the progressive difficulty training principle (for which difficulty impedes performance in the learning stage but facilitates retention). It is suggested that, when training perceptual-motor tasks, tasks practiced during the learning phase should match the transfer task. Manipulation of task difficulty may play a role only if the tasks share task-relevant cognitive processes and mental models. ^ The overall findings of this research provide: 1) better understanding of skill development for the operation of construction equipment, and 2) evidence as to how the trainees can better utilize their time when training on a single machine and concurrently on multiple machines. The findings add to the general body of knowledge on perceptual-motor skill acquisition and to that on training in a specific domain via a specific technology. The findings are expected to generalize to heavy equipment training in related domains, such as forestry and mining, and domains requiring instrument handling skills and robotic arms, such as surgery and orbital space vessel external operations

Water Fun at Exploration Station

This report documents the design and fabrication processes involved for the creation of an interactive science exhibit for the Grover Beach Exploration Station. This is a student-led senior project advised by Sarah Harding, professor of mechanical engineering, as a part of California Polytechnic State University in San Luis Obispo’s mechanical engineering program. The final product is a fully functioning, durable system that is capable of pumping and recycling water throughout use when users are in its vicinity. The exhibit is to be considered in 4 main subsystems: basin, plumbing, frame, and sleep mode system. A fiberglass basin that holds all the water in the exhibit sits recessed inside a welded steel frame. Water is pumped through the bottom of the basin from within an enclosed storage area inside the frame, and is recycled back into the water reservoir by placement of two weir valves. A submersible pump powers the exhibit, and is controlled by passive infrared sensors that activate when human presence is sensed within 15ft. While the manufacturing process did reach completion, testing and verification did not. However, proposed testing plans are still included in the appendices of the report for informational purposes. Divided into distinct sections, this report will enlighten the reader on each part of the design process. First, background research and preliminary design explains the methodology of developing the vision of the final design. Next, different design analysis techniques are given for each respective subsystem of the proposed exhibit. An in-depth description for manufacturing and testing of the completed exhibit is given for each subsystem. Finally, recommendations are given for future improvements to the exhibit, and what kinds of different decisions would be made in the design process if given a second iteration

"A most exquisite fellow" — William White and an Atlantic world perspective on the seventeenth-century chymical furnace

The seventeenth-century technologist and colonist William White (ca. 1600–73) has been cited as an alchemical tutor to Gabriel Plattes and George Starkey, and hailed as an early modern “wizard of industrial efficiency.” This study — the first that focuses on White individually — pays particular attention to White’s extraordinary reputation for furnace design and manufacture. By examining the sources of knowledge and social connections that enabled White to acquire and disseminate his knowledge of metallurgy, the authors develop a genealogy of fornacic design that extends from the continent to the Atlantic world and back again, connecting White to better known figures such as Cornelis Drebbel and Robert Boyle. By foregrounding, through White, the technology of early modern alchemy, the authors also hope to emphasise the importance of practical craft in the development of the chemical arts