Prediction of VO\u3csub\u3e2\u3c/sub\u3e Peak Using Sub-Maximum Bench Step Test in Children

The purpose of this study was to develop a valid prediction of maximal oxygen uptake from data collected during a submaximum bench stepping test among children ages 8-12 years. Twentyseven active subjects (16 male and 11 female), weight 36.1 kg, height 144.4 cm and VO2 47.4 ± 7.9 ml/kg/min participated. Subjects completed a maximal oxygen consumption test with analysis of expired air and a submaximal bench stepping test. A formula to predict VO2max was developed from height, resting heart rate and heart rate response during the submaximum bench stepping test. This formula accounted for 71% of the variability in maximal oxygen consumption and is the first step in verifying the validity of the submaximum bench stepping test to predict VO2max. VO2max = -2.354 + (Height in cm * 0.065) + (Resting Heart Rate * 0.008) + (Step Test Average Heart Rate as a Percentage of Resting Heart Rate * -0.870

Space, the new frontier

Space program - high thrust boosters with greater payload capabilities, superior guidance and control, and astronaut trainin

Solution of large scale nuclear structure problems by wave function factorization

Low-lying shell model states may be approximated accurately by a sum over products of proton and neutron states. The optimal factors are determined by a variational principle and result from the solution of rather low-dimensional eigenvalue problems. Application of this method to sd-shell nuclei, pf-shell nuclei, and to no-core shell model problems shows that very accurate approximations to the exact solutions may be obtained. Their energies, quantum numbers and overlaps with exact eigenstates converge exponentially fast as the number of retained factors is increased.Comment: 12 pages, 12 figures (from 15 eps files) include

Electrostatic interactions mediated by polarizable counterions: weak and strong coupling limits

We investigate the statistical mechanics of an inhomogeneous Coulomb fluid composed of charged particles with static polarizability. We derive the weak- and the strong-coupling approximations and evaluate the partition function in a planar dielectric slab geometry with charged boundaries. We investigate the density profiles and the disjoining pressure for both approximations. Comparison to the case of non-polarizable counterions shows that polarizability brings important differences in the counterion density distribution as well as the counterion mediated electrostatic interactions between charged dielectric interfaces.Comment: 25 pages, 7 figure

Benchmark calculations for elastic fermion-dimer scattering

We present continuum and lattice calculations for elastic scattering between a fermion and a bound dimer in the shallow binding limit. For the continuum calculation we use the Skorniakov-Ter-Martirosian (STM) integral equation to determine the scattering length and effective range parameter to high precision. For the lattice calculation we use the finite-volume method of L\"uscher. We take into account topological finite-volume corrections to the dimer binding energy which depend on the momentum of the dimer. After subtracting these effects, we find from the lattice calculation kappa a_fd = 1.174(9) and kappa r_fd = -0.029(13). These results agree well with the continuum values kappa a_fd = 1.17907(1) and kappa r_fd = -0.0383(3) obtained from the STM equation. We discuss applications to cold atomic Fermi gases, deuteron-neutron scattering in the spin-quartet channel, and lattice calculations of scattering for nuclei and hadronic molecules at finite volume.Comment: 16 pages, 5 figure

Composite battery separator

A composite battery separator comprises a support element (10) having an open pore structure such as a ribbed lattice and at least one liquid permeable sheet (20,22) to distribute the compressive force evenly onto the surfaces of the layers (24, 26) of negative active material and positive active material. In a non-flooded battery cell the compressible, porous material (18), such as a glass mat which absorbs the electrolyte, is compressed into a major portion of the pores or openings (16) in the support element. The unfilled pores in the material (18) form a gas diffusion path as the channels (41) formed between adjacent ribs in the lattice element (30,36). Facing two lattice elements (30, 31) with acute angled cross-ribs (34, 38) facing each other prevents the elements from interlocking and distorting a porous, separator (42) disposed between the lattice elements

Quasi-bipolar battery construction and method of fabricating

A lightweight, battery construction for lead acid batteries in which biplates are formed from a continuous strip of thermoplastic material, one face of the strip being provided with a plurality of electrically isolated lead strip arrays, each having a transverse axis about which the strip is folded or pleated to provide pleated biplate walls. The pleated continuous strip is sealed along edge longitudinal portions to provide chambers for receiving a plurality of non-conductive thermoplastic separator-plates and to contain electrolyte liquid. Separator-plates support resilient yieldable porous glass mats and scrim fabric in which active material is carried. The assembly of pleated biplates and separator-plates is maintained in pressure relation by exterior resilient means. A method of making such a continuous pleated biplate construction and of assembling one or more battery modules which may be connected in series or in parallel. A biplate construction having continuously wound lead stripes attached to a substrate

FET commutated current-FED inverter

A shunt switch comprised of a field-effect transistor (Q.sub.1) is employed to commutate a current-fed inverter (10) using thyristors (SCR1, SCR2) or bijunction transistors (Q.sub.2, Q.sub.3) in a full bridge (1, 2, 3, 4) or half bridge (5, 6) and transformer (T.sub.1) configuration. In the case of thyristors, a tapped inverter (12) is employed to couple the inverter to a dc source to back bias the thyristors during commutation. Alternatively, a commutation power supply (20) may be employed for that purpse. Diodes (D.sub.1, D.sub.2) in series with some voltage dropping element (resistor R.sub.12 or resistors R.sub.1, R.sub.2 or Zener diodes D.sub.4, D.sub.5) are connected in parallel with the thyristors in the half bridge and transformer configuration to assure sharing the back bias voltage. A clamp circuit comprised of a winding (18) negatively coupled to the inductor and a diode (D.sub.3) return stored energy from the inductor to the power supply for efficient operation with buck or boost mode

Bipolar battery construction

A lightweight, bipolar battery construction for lead acid batteries in which a plurality of thin, rigid, biplates each comprise a graphite fiber thermoplastic composition in conductive relation to lead stripes plated on opposite flat surfaces of the plates, and wherein a plurality of nonconductive thermoplastic separator plates support resilient yieldable porous glass mats in which active material is carried, the biplates and separator plates with active material being contained and maintained in stacked assembly by axial compression of the stacked assembly. A method of assembling such a bipolar battery construction