Spin structure functions

We review the study of the internal spin structure of the proton and neutron. High-energy scattering of polarized leptons by polarized protons, neutrons, and deuterons provides a measurement of the nucleon spin structure functions. These structure functions give information on the polarized quark contributions to the spin of the proton and the neutron and allow tests of the quark-parton model and quantum chromodynamics. We discuss the formalism of deep inelastic scattering of polarized leptons on polarized nucleons, the past decade of experimental progress, and future programs to measure the polarized gluon contribution to the proton spin

A Pyralid Moth (Lepidoptera) as Pollinator of Blunt-Leaf Orchid

(excerpt) As early as 1912, mosquitoes were observed bearing the pollen masses (pollinia) of the blunt-leaf orchid, Habenaria obtusata (Pursh) Richardson, in Reese\u27s Bog, a cedar swamp at the north end of Burt Lake, Cheboygan County, Michigan, near the campus of the University of Michigan Biological Station (Dexter 1913)

Pressurized bellows flat contact heat exchanger interface

Disclosed is an interdigitated plate-type heat exchanger interface. The interface includes a modular interconnect to thermally connect a pair or pairs of plate-type heat exchangers to a second single or multiple plate-type heat exchanger. The modular interconnect comprises a series of parallel, plate-type heat exchangers arranged in pairs to form a slot therebetween. The plate-type heat exchangers of the second heat exchanger insert into the slots of the modular interconnect. Bellows are provided between the pairs of fins of the modular interconnect so that when the bellows are pressurized, they drive the plate-type heat exchangers of the modular interconnect toward one another, thus closing upon the second heat exchanger plates. Each end of the bellows has a part thereof a thin, membrane diaphragm which readily conforms to the contours of the heat exchanger plates of the modular interconnect when the bellows is pressurized. This ensures an even distribution of pressure on the heat exchangers of the modular interconnect thus creating substantially planar contact between the two heat exchangers. The effect of the interface of the present invention is to provide a dry connection between two heat exchangers whereby the rate of heat transfer can be varied by varying the pressure within the bellows

Optical-fiber source of polarization-entangled photon pairs in the 1550nm telecom band

We present a fiber based source of polarization-entangled photon pairs that is well suited for quantum communication applications in the 1550nm band of standard fiber-optic telecommunications. Polarization entanglement is created by pumping a nonlinear-fiber Sagnac interferometer with two time-delayed orthogonally-polarized pump pulses and subsequently removing the time distinguishability by passing the parametrically scattered signal-idler photon pairs through a piece of birefringent fiber. Coincidence detection of the signal-idler photons yields biphoton interference with visibility greater than 90%, while no interference is observed in direct detection of either the signal or the idler photons. All four Bell states can be prepared with our setup and we demonstrate violations of CHSH form of Bell's inequalities by up to 10 standard deviations of measurement uncertainty.Comment: 12 pages, 4 figures, to be submitted to Phys. Rev. Lett. See also paper QTuB4 in QELS'03 Technical Digest (OSA, Washington, D.C., 2003). This is a more complete versio

Vortex-glass transition in superconducting Nb/Cu superlattices

Nb/Cu superconducting superlattices have been fabricated by dc magnetron sputtering. This system shows a vortex glass transition with critical exponents similar to high temperatures superconductors exponents. The transition dymensionality is governed by the superconducting coupling regime. The vortex glass transition shows a pure two dimensional behavior in decoupled superlattices and a quasi-two dimensional behavior in the superlattice coupling regime.Comment: 9 pages, 3 figure

Shuttle active thermal control system development testing. Volume 2: Modular radiator system tests

Tests were designed to investigate the validity of the "modular" approach to space radiator system design for space shuttle and future applications by gathering performance data on various systems comprised of different numbers of identical panels, subject to nominal and extreme heat loads and environments. Both one-sided and two-sided radiation was tested, and engineering data was gathered on simulated low a/e coatings and system response to changes in outlet temperature control point. The results of the testing showed system stability throughout nominal orbital transients, unrealistically skewed environments, freeze-thaw transients, and rapid changes in outlet temperature control point. Various alternative panel plumbing arrangements were tested with no significant changes in performance being observed. With the MRS panels arranged to represent the shuttle baseline system, a maximum heat rejection of 76,600 Btu/hr was obtained in segmented tests under the expected worst case design environments. Testing of an alternate smaller two-sided radiation configuration yielded a maximum heat rejection of 52,931 Btu/hr under the maximum design environments

Re-evaluating Alien Exclusion in Light of AIDS

The Immigration and Naturalization Service has adopted an AIDS testing program to screen individuals requesting permanent status in the United States. The comment discusses this complex disease and the accompanying legal ramifications on immigration law, given the traditional bases for exclusion of aliens

A Survey of the Status of Conservation Education in Junior High Schools of Eight Selected Counties in Northwest Iowa

In recent years the subject of conservation has acquired considerable importance throughout this country. The very nature of the problem has become so broad as to include nearly every facet of our daily lives. It has come to include human lives, consumer education, and production along with the more traditional areas of our natural resources such as forests, minerals, soil, and water. As with other contemporary topics, this subject has many implications for American education. It has becorr1e increasingly evident that if we are to maintain our present high standards of living, some effort in education has to be put forth to aid in this phase of the problem. Although there have been many articles published on this subject, very little of the subject has been investigated on an objective basis. The problem is fundamentally one for society as a whole in that conservation has projected itself into this nation\u27s economy and production. Thus the destruction of our natural resources in one area has had effects not only on the immediate area but throughout the country as a whole. Conservationists in our government have accomplished much in the past in dealing with this problem; however, as has been the case with similar problems, the final solution was dependent on an understanding of conservation and a resultant cooperation in conservation work by all members of society. The problem of an under standing of the wide ramifications of the conservation program has become a problem for education. Conservation education has not kept pace with practices in the field of conservation. Hence, the purpose of this study was to determine the current status of conservation education in the schools of a particular geographic area in northwest Iowa. It was thought that if the current status was known, it might then be possible to plan a program of improvement of the conservation-education program and through it effect improvement in the whole conservation program throughout the country

An Online Wideband Acoustic Immittance (WAI) Database andCorresponding Website: Resource Review

Wideband acoustic immittance (WAI) measures, which include absorbance, power reflectance, impedance, and other related quantities, offer an objective, noninvasive diagnostic tool for some middle-ear pathologies. An online database for normative adult WAI measures has been designed and implemented in MySQL, with the goal of enabling researchers to share and analyze data across studies. Access database through ScholarWorks here: https://scholarworks.smith.edu/dds_data/6 Or directly here: http://www.science.smith.edu/wai-database