The PIT MkV pulsed inductive thruster

The pulsed inductive thruster (PIT) is an electrodeless, magnetic rocket engine that can operate with any gaseous propellant. A puff of gas injected against the face of a flat (spiral) coil is ionized and ejected by the magnetic field of a fast-rising current pulse from a capacitor bank discharge. Single shot operation on an impulse balance has provided efficiency and I(sub sp) data that characterize operation at any power level (pulse rate). The 1-m diameter MkV thruster concept offers low estimated engine mass at low powers, together with power capability up to more than 1 MW for the 1-m diameter design. A 20 kW design estimate indicates specific mass comparable to Ion Engine specific mass for 10,000 hour operation, while a 100,000 hour design would have a specific mass 1/3 that of the Ion Engine. Performance data are reported for ammonia and hydrazine. With ammonia, at 32 KV coil voltage, efficiency is a little more than 50 percent from 4000 to more than 8000 seconds I(sub sp). Comparison with data at 24 and 28 kV indicates that a wider I(sub sp) range could be achieved at higher coil voltages, if required for deep space missions

Nearly Deterministic Bell Measurement for Multiphoton Qubits and Its Application to Quantum Information Processing

We propose a Bell measurement scheme by employing a logical qubit in Greenberger-Horne-Zeilinger (GHZ) entanglement with an arbitrary number of photons. Remarkably, the success probability of the Bell measurement as well as teleportation of the GHZ entanglement can be made arbitrarily high using only linear optics elements and photon on-off measurements as the number of photons increases. Our scheme outperforms previous proposals using single photon qubits when comparing the success probabilities in terms of the average photon usages. It has another important advantage for experimental feasibility that it does not require photon number resolving measurements. Our proposal provides an alternative candidate for all-optical quantum information processing.Comment: 7 pages (including supplementary material), 2 figures, to be published in Phys. Rev. Let

Plateau characteristics of Geiger Counters with respect to different gas mixtures and pressures

The section of a Geiger Counter is characterized by the so-called plateau curve. In this curve the counting rate of a given counter is plotted as a function of voltage, when the gas which it contains and the radiation to which it is exposed are both kept the same. These curves are characterized by a rapid rise beyond the starting potential (potential at which the counter begins to respond) until a more or less flat region is reached. This flat region is called the plateau of the curve. The slope and width of the plateau curve are dependent upon the kind of gas used to fill the counter, the pressure of the gas, and the mechanical construction of the counter. The plateau slope of a perfect counter would be zero, and the counting rate would be independent of voltage fluctuations, but zero slope is not possible because of the occurrence of spurious counts which originate inside the counter. The term selfquenching counter has been applied in recent years to the types of Geiger Counters in which the discharge terminates because of a process inside the counter. These counters do not go into continuous discharge except at high voltages. In order that a counter may operate as the selfquenching type it must be filled with a certain minimum amount of a polyatomic gas as a constituent. The purpose of this study is to examine the effect of filling a counter with various polyatomic gases and helium. A search was made for a gas mixture to fill the counter which would give a high count per minute and still have desirable plateau characteristics --Introduction, page 1-2

The chemical analysis of Velella Lata float

Everything should be ultimately explainable in terms of the components of which it is composed. In the animal kingdom well over ninety-five percent of all recognized species are invertebrates, a distinction based on connective tissues, though most of our efforts have been directed towards vertebrates for reasons of convenience and closeness to man. Investigation of the various chemicals which make up plants and animals have been diverse, allowing us to get a general picture of what molecules to expect at each state of the evolutionary progression, but for now animal is the information complete, and for invertebrates the information is particularly sketchy. It would be convenient to have certain animals and plants completely known chemically, so that biological molecules subsequently discovered could be compared to these standards. Velella lata may be a candidate for such a standard, having a number of unique advantages. It occurs in the evolutionary chain at that point where a true multicellular animal begins, and it is the simplest animal from which genetically determined internal structural materials is conveniently isolated and purified. In plants the connective tissue is considered to be almost entirely carbohydrate polymer and in vertebrates the connective tissue is considered to be almost entirely protein (amino acid polymer), while many invertebrates have almost even mixture of protein carbohydrate in an unknown relationship. Velella presents an opportunity to examine closely the nature of the protein and its relationship to the carbohydrate. The carbohydrate of various invertebrates connective tissue matrices has been extensively studies and the structure and linkages reasonably well defined. Some questions remain regarding the length of the smallest oligosaccaride and the manner in which these are built up into higher levels of organization. Inorganic material (primarily in the form of calcium), lipid in small amounts, and moisture are also present in the invertebrate matrix. While calcium is generally considered to be in the form of the carbonate, the possibility that it is not all in this form awaits investigation, and the recent report that silicon is essential in the formation of chick connective tissues is interesting.5 Lipids are not a major component in connective tissues studied to date, and this is true of Velella also. This does not preclude, however, the possibility that lipids may play some role in the formation of membrane-like sheets which are observed in the laminations of various mollusk-arthropod matrices. Velella offers an opportunity to examine invertebrate connective tissue in an intense way to gain an understanding of the morphology and developmental dynamics which hopefully would be extensible to the vertebrate matrix

An enquiry into the moral and religious factors of Carl Sandburg\u27s poetry

https://place.asburyseminary.edu/ecommonsatsdissertations/2356/thumbnail.jp

Identification of the products and mechanism of the disproportionation of DI(p-sulfonic acid)phenylthiocarbazide

It is the purpose of this paper to separate and identify the products resulting from treatment of this compound with strong base. This will be done using both column and paper chromatography, and through interpretation of infrared spectra. In addition, a discussion of the structure of the complexes of heavy metals with di(p-sulfonic acid) phenylthiocarbazide in basic solution will be presented

The Development Of A Consensus Model To Select, Establish And Implement Minimal Competencies In California Unified School Districts

The purpose of this study was to provide a model for California unified school districts to establish minimal competencies and to provide added direction, guidance and support to those districts that had already adopted them. The model was based on a consensus of selected unified · school districts throughout California. It sought to establish a step-by-step process which any school district could follow. To accomplish this purpose, the following objectives were addressed: 1. To specify minimum competencies in identified curriculum areas 2. To ascertain who will recommend to the Board of Education the minimum acceptable levels of student performances and how the levels will be established 3. To create a manageable measurement scheme consistent with the adopted competencies 4. To determine the disposition of students who do not attain acceptable competency levels. PROCEDURE: This study was descriptive and employed the interview as the primary data-gathering technique. The procedures employed in conducting this study were the following: (1) a review of the relevant literature to identify procedures in establishing minimal competencies; (2) the construction of an interview instrument to gather specific information on how minimum competencies in curriculum areas could be identified and to ascertain the most beneficial methods of implementing minimal competencies; (3) the selection of twelve unified school districts in California for interviews; (4) the administration of the interview; (5) the tabulation and treatment of the data; and (6) the development of a model which could assist districts in the implementation and identification of minimal competencies. FINDINGS: In the selection general agreement among the working committee consisted the Director of Curriculum. of committee personnel the interviewees was that the main of teacher representatives and When choosing committee members, the principals from each school chose the members to serve. In choosing the chairman of the committee, the general agreement was that the chairman was selected by the superintendent of the district. In dividing committee members into subcommittees, the consensus was that the main committee divided into subcommittees at the beginning of each meeting and met later as the main committee. At least one year is needed to do an effective job in selecting minimal competencies. When asked if community members were given an opportunity to express their opinions, the consensus was that parents were given a chance to express their opinions after the competencies had been selected by the main committee. Parents were mostly concerned over whether standards were set high enough. When asked which competencies students had to pass in order to graduate, the consensus was that students must exhibit competencies in reading, writing and computation. In establishing criteria for passing the reading competencies, the consensus was that students must demonstrate knowledge in four different categories. When asked how districts actually selected competencies, interviewees replied that the main committee met ·first, selected competencies and then gave the list to the parent committee for comments and revisions. The main committee had a second opportunity to change the competencies after they had been reviewed by the parent committee and then submitted the final list to the board for approval. In establishing criteria for passing the math competencies, students had to demonstrate knowledge in ten different main categories. In discussing the criteria for passing the writing competencies, the student had to demonstrate knowledge of spelling, capitalization, punctuation and grammar as well as show he could write a logical composition. He had to stick to the main point, use examples and show logical thinking. Measurement Instruments: When asked what measurement instruments would be used to measure students in reading, districts indicated they would be using teacher selected materials such as newspapers, magazine articles and paragraphs written by teachers. In math, test items would be constructed by teachers. In writing, test items would also be constructed by teachers as well as kinds of compositions to be written by the students. Rationale for Selection: In choosing the rationale for selecting measurement instruments in reading, writing and computation, the consensus was that students ought to be able to read certain forms, compute certain figures and write with certain skills in order to get along in life after graduation. Implementation of Competencies: All interviewees replied that inservice workshops concerning implementing the competencies were held during the year. The main point all districts stressed was that teachers and staff had known about minimal competencies from the time committees first started working on them. Staff members were informed, through representatives, on the progress of the committee and were allowed to make suggestions and revisions throughout the year. Student Remediation Procedures: All districts replied that arrangements would be made for a conference to take place between the teacher, parent, student and counselor when a student had shown he could not pass the competencies. At the conference it would be decided how many periods a day the student would be attending a competency lab and which remediation materials he would be needing in order to pass specific competencies. Competency Labs had been established at every high school. These labs were for the purpose of helping all students who had failed parts of the competency test. Most students would be attending the competency lab at least one full period a day. Differential standards would be used when testing students who had been identified as Learning Disabled. All districts replied that there would be no differential standards for students of limited English speaking ability and that all students would take the competency test in English. Special help would be given to handicapped students in order for them to take the regular competency test along with the other students. RECOMMENDATIONS: Further models should be developed after minimal competency testing is actually implemented in the schools. Specific attention should be given to the following questions: (1) Since the tests have been given, have minimal competency standards been raised or lowered? (2) Since the tests have been given, what revisions have been made in each of the three main competencies? (3) Since the tests have been given, what have school districts done to check their revised tests for reliability and validity? (4) How many students in the various school districts actually failed the tests? (5) How effective have the competency labs been for remedial students? (6) What percentage of limited English speaking students have failed the test? (7) If there has been a large percentage of limited English speaking students failing the test, what does the district intend to do about it? (8) Has the legality of minimal-competency testing been challenged in the courts by various parents of students failing the tests? If so what have been the results? (9) Have minimal competency tests made any difference in the attitude of taxpayers in the community? and (10) Have minimal competency tests made any difference in the attitude of teachers (in the way teachers teach)

Cost Estimate Modeling of Transportation Management Plans for Highway Projects, Research Report 11-24

Highway rehabilitation and reconstruction projects frequently cause road congestion and increase safety concerns while limiting access for road users. State Transportation Agencies (STAs) are challenged to find safer and more efficient ways to renew deteriorating roadways in urban areas. To better address the work zone issues, the Federal Highway Administration published updates to the Work Zone Safety and Mobility Rule. All state and local governments receiving federal aid funding were required to comply with the provisions of the rule no later than October 12, 2007. One of the rule’s major elements is to develop and implement Transportation Management Plans (TMPs). Using well-developed TMP strategies, work zone safety and mobility can be enhanced while road user costs can be minimized. The cost of a TMP for a road project is generally considered a high-cost item and, therefore, must be quantified. However, no tools or systematic modeling methods are available to assist agency engineers with TMP cost estimating. This research included reviewing TMP reports for recent Caltrans projects regarding state-of-the-art TMP practices and input from the district TMP traffic engineers. The researchers collected Caltrans highway project data regarding TMP cost estimating. Then, using Construction Analysis for Pavement Rehabilitation Strategies (CA4PRS) software, the researchers performed case studies. Based on the CA4PRS outcomes of the case studies, a TMP strategy selection and cost estimate (STELCE) model for Caltrans highway projects was proposed. To validate the proposed model, the research demonstrated an application for selecting TMP strategies and estimating TMP costs. Regarding the model’s limitation, the proposed TMP STELCE model was developed based on Caltrans TMP practices and strategies. Therefore, other STAs might require adjustments and modifications, reflecting their TMP processes, before adopting this model. Finally, the authors recommended that a more detailed step-by-step TMP strategy selection and cost estimate process be included in the TMP guidelines to improve the accuracy of TMP cost estimates

Implementation of a coal level sensing and control system comparing range sensor modalities

A coal-fired power plant typically has silos, bunkers or stockpiles in which the fuel is placed for storage purposes. Real-time feedback sensors are utilized to sense the coal height so data can be sent to downstream systems for further processing. These systems are required to accurately sense the height of coal within the bunker or stockpile. The range information is then fed in a real-time fashion to a control system. Inaccurate measurements can result in severe environment and safety consequences. The coal-fired power plant application is especially daunting due to the particularly harsh operating conditions and reliability requirements. There are many types of ranging sensors available in the marketplace. The performance of ultrasonic, radar, and laser rangefinder sensors was investigated to determine the height of coal stockpiles in various sites in a coal-fired power plant. A system to control the spacing of a telescoping coal-delivery chute above its coal pile was designed (using laser rangefinder), implemented, and tested. A detailed analysis of each sensor modality is provided, along with some conclusions regarding their performance. These systems are currently operational at a plant located in northeast Texas. The ultrasonic and radar sensors were part of legacy systems and the new laser sensor was integrated as a part of this study. The feedback signals from each sensor were compared to measured data. The implementation of the laser rangefinders proved to be slightly more accurate than the other legacy systems. However, the laser rangefinder systems have some drawbacks that have been listed