The Design of Pumpjets for Hydrodynamic Propulsion

A procedure for use in the design of a wake adapted pumpjet mounted on the aft end of a body of revolution is presented. To this end, a pumpjet is designed for the Akron airship. The propulsor mass flow is selected to minimize kinetic energy losses through the duct and in the discharge jet. The shaft speed and disk size are selected to satisfy specified limits of cavitation performance and to provide acceptable blade loading. The streamtubes which pass through a propulsor mounted on a tapered afterbody follow essentially conical surfaces. A method is provided for defining these surfaces as a function of shroud geometry, rotor head distribution, and the energy distribution of the ingested mass flow. The three-dimensional effects to which the conical flow subjects the cylindrical blade design sections are described and a technique is presented which permits incorporation of these effects in the blade design procedure

Fluid mechanics, acoustics, and design of turbomachinery, part 1

A conference was conducted to analyze the effects of air flow on turbomachinery design. The subjects discussed are: (1) equations for compressible flow through turbomachines, (2) influence of axial velocity ratio on cascade performance, (3) three dimensional flow in transonic axial compressor blade rows, (4) prediction of turbulent shear layers in turbomachines, and (5) boundary layers in centrifugal compressors

That Society Rag

Illustration of couple dancinghttps://scholarsjunction.msstate.edu/cht-sheet-music/4318/thumbnail.jp

A Role for Msh6 But Not Msh3 in Somatic Hypermutation and Class Switch Recombination

Somatic hypermutation is initiated by activation-induced cytidine deaminase (AID), and occurs in several kilobases of DNA around rearranged immunoglobulin variable (V) genes and switch (S) sites before constant genes. AID deaminates cytosine to uracil, which can produce mutations of C:G nucleotide pairs, and the mismatch repair protein Msh2 participates in generating substitutions of downstream A:T pairs. Msh2 is always found as a heterodimer with either Msh3 or Msh6, so it is important to know which one is involved. Therefore, we sequenced V and S regions from Msh3- and Msh6-deficient mice and compared mutations to those from wild-type mice. Msh6-deficient mice had fewer substitutions of A and T bases in both regions and reduced heavy chain class switching, whereas Msh3-deficient mice had normal antibody responses. This establishes a role for the Msh2-Msh6 heterodimer in hypermutation and switch recombination. When the positions of mutation were mapped, several focused peaks were found in Msh6−/− clones, whereas mutations were dispersed in Msh3−/− and wild-type clones. The peaks occurred at either G or C in WGCW motifs (W = A or T), indicating that C was mutated on both DNA strands. This suggests that AID has limited entry points into V and S regions in vivo, and subsequent mutation requires Msh2-Msh6 and DNA polymerase

HD 71636, A Newly Discovered Eclipsing Binary

Our differential BV photometric observations, acquired with an automated telescope at Fairborn Observatory, show that HD 71636 is an eclipsing binary. From follow-up red-wavelength spectroscopic observations we classify the primary and secondary as an F2 dwarf and an F5 dwarf, respectively. The system has a period of 5.01329 days and a circular orbit. We used the Wilson-Devinney program to simultaneously solve our BV light curves and radial velocities and determined a number of fundamental properties of the system. Comparison with evolutionary tracks indicates that both stars are well ensconced on the main sequence. The age of the system is about 1.2 billion years

A Critical Examination of Contemporary Legal Issues Important to College Presidents

This discussion provides a highlight of the legal dimensions that college presidents must consider in providing oversight for college operations. Many of these issues are driven by the behaviors of campus constituents, but several key legal issues are also the result of federal legislation and involvement in higher education

Environmental impact assessment of the Ruth Creek Hydroelectric Project

The ensuing document presents the potential environmental impacts from a proposal submitted by the Free Flow Power Corporation of Massachusetts to the Federal Energy and Regulatory Commission for the development of a small-scale hydroelectric project on Ruth Creek, WA. Upon evaluating the existing conditions and likely effects of the proposed actions, we present an alternative solution of comparable cost and power generation, an enhancement of the earth-fill dam already in place on Cle Elum Reservoir, near of Roslyn, WA. Located in Whatcom County within Mount Baker-Snoqualmie National Forest, the Ruth Creek tributary meanders from alpine settings at its glacial headwaters to the North Fork Nooksack River, a distance less than 10 miles from Ruth Glacier. The 93 acre proposal stipulates the placement of a 100ft long, run-of-the-river, ogee mid-stream weir to partially divert flow to an impounded pond where an intake structure would reside, equipped with a trash rack, fish screen and closure gate. The impounded pond is expected to be relatively small, having a surface area of 0.10 acres and volume of 0.4 acre-feet. Upon entering the intake, water will travel down a ~8000ft long, 42 diameter steel penstock with both above and below ground sections. The water then reaches the powerhouse complex where it spins turbines before returning to the creek via a 20ft long, 6x6ft concrete culvert followed by a 20ft long, 12ft wide lined rip rap tailrace that will blend with the creek bank. The resultant power generation capacity is expected to be 2.5MW, with an estimated average annual energy production of 10GWh. The power generated will travel across the proposed 55kVA transmission lines, which are expected to be ~2.2 miles long and will connect to the local utility grid. Approximately 500ft of new access roads will need to be constructed to connect both the powerhouse complex and intake/weir structures to NF Develop Road 32. Environmental concerns based on both the location and lack of development in the surrounding area are discussed further in the body of this document. Based on the expressed purpose of the aforementioned proposal to generate electricity, we also present an alternative to acquiring the power output desired from the Ruth Creek proposal, The Cle Elum Hydroelectric Project. Also applied for by Free Flow Power, this proposal is located in a starkly different geographic landscape in Kittitas County, just north of Interstate 90, WA. The Cle Elum Reservoir is held in place by a 165ft tall earth-fill dam, owned and operated by the US Bureau of Reclamation since 1933 to mitigate flood events, provide irrigation to local farms and pastures, offer recreational activities, and serve fish and wildlife purposes. The alternative proposal suggests enhancing the existing dam to also produce hydroelectric power. This venture would be accomplished by constructing a spillway, ~1,000ft long penstock, 7,000sqft powerhouse and a 15MVa substation. The project encompasses less than 6 acres of land and is expected to generate 18.0MW of power. Concerning environmental impacts from this proposal are discussed further in the body of this document and surmised in the conclusion. The intent and purpose of this impact assessment is to evaluate the severity and scope of potentially adverse effects on the environment due to the proposed construction. These elements were thoroughly examined in an objective manner to ensure fair assessment of both the proposed action and suggested alternative under the Washington State Environmental Policy Act (SEPA) and the National Environmental Policy Act (NEPA). The sections presented hereafter describe in detail the elements of the environment that pertain to small-scale hydroelectric projects, the light & glare and housing elements were omitted due to their irrelevance to these proposals. After interpreting our results and quantifying likely impacts, we conclude that the alternative presented would likely produce fewer and less severe adverse effects on the surrounding environment than the proposed action, the proposed alternative is, therefore, our recommendation

Absence of DNA Polymerase η Reveals Targeting of C Mutations on the Nontranscribed Strand in Immunoglobulin Switch Regions

Activation-induced cytosine deaminase preferentially deaminates C in DNA on the nontranscribed strand in vitro, which theoretically should produce a large increase in mutations of C during hypermutation of immunoglobulin genes. However, a bias for C mutations has not been observed among the mutations in variable genes. Therefore, we examined mutations in the μ and γ switch regions, which can form stable secondary structures, to look for C mutations. To further simplify the pattern, mutations were studied in the absence of DNA polymerase (pol) η, which may produce substitutions of nucleotides downstream of C. DNA from lymphocytes of patients with xeroderma pigmentosum variant (XP-V) disease, whose polymerase η is defective, had the same frequency of switching to all four γ isotypes and hypermutation in μ-γ switch sites (0.5% mutations per basepair) as control subjects. There were fewer mutations of A and T bases in the XP-V clones, similar to variable gene mutations from these patients, which confirms that polymerase η produces substitutions opposite A and T. Most importantly, the absence of polymerase η revealed an increase in C mutations on the nontranscribed strand. This data shows for the first time that C is preferentially mutated in vivo and pol η generates hypermutation in the μ and γ switch regions