Development of the dry tape battery concept Quarterly report no. 4, 9 Mar. - 9 Jun. 1966

Aqueous and nonqueous electrolytic actions, and energy density measurements for dry tape batter

Development of the dry tape battery concept Quarterly report no. 3, 9 Dec. 1965 - 8 Mar. 1966

Material electrical and chemical properties tested for use in dry tape batterie

Measurement of the Tip-Induced Potential in Scanning Gate Experiments

We present a detailed experimental study on the electrostatic interaction between a quantum dot and the metallic tip of a scanning force microscope. Our method allowed us to quantitatively map the tip-induced potential and to determine the spatial dependence of the tip's lever arm with high resolution. We find that two parts of the tip-induced potential can be distinguished, one that depends on the voltage applied to the tip and one that is independent of this voltage. The first part is due to the metallic tip while we interpret the second part as the effect of a charged dielectric particle on the tip. In the measurements of the lever arm we find fine structure that depends on which quantum state we study. The results are discussed in view of scanning gate experiments where the tip is used as a movable gate to study nanostructures.Comment: 7 pages, 5 figures, minor changes to fit published versio

Thin-Film Trilayer Manganate Junctions

Spin-dependent conductance across a manganate-barrier-manganate junction has recently been demonstrated. The junction is a La$_{0.67}$Sr$_{0.33}$MnO$_3$% -SrTiO$_3$-La$_{0.67}$ Sr$_{0.33}$MnO$_3$ trilayer device supporting current-perpendicular transport. Large magnetoresistance of up to a factor of five change was observed in these junctions at 4.2K in a relatively low field of the order of 100 Oe. Temperature and bias dependent studies revealed a complex junction interface structure whose materials physics has yet to be understood.Comment: 20 pages, 14 figures. To appear in Phil. Trans. R. Soc. Lond. A vol.356 (1998

Pilot Study investigating the Impact of Serial ingestion or Co-ingestion of Creatine and Sodium bicarbonate on Performance Following Completion of a Hypertrophy Type Resistance Exercise Workout.

Purpose: To examine the ergogenic potential of creatine (Cr), sodium bicarbonate (SB),and Cr+SBafter completion of a resistance exercise bout (REB).Methods: Following recruitment,27trained males (26.8±5.7 years old) completed a one repetition maximum strength (1RM) test in the parallel squat (120.9±28.2kg). Participants then followed a standardised meal plan for 4 days whilst ingesting one of 4 supplements, and on day 5 they undertook the REB. This was a double blind randomised placebo-controlled study where participants ingested one of the following: Placebo (PLA, n=7), Cr (20g/d-1& PLA, n=8), SB (0.5 g/kg-1/d-1&PLA, n=6), andCr+SB (5 g/d-1 of Cr & 0.5 g/kg-1/d-1 SB, n=6) divided in 4 doses. The REB consisted of 4x10 repetitions (70% of 1RM, 1½ min recovery). The primary performance outcome was a 5th set (70% of 1RM) performed to volitional exhaustion.Blood glucose and lactate, heart rate, ratings of perceived exertion, sickness and stomachache scales, and time to complete each set were also recorded.Results:Participants in Cr, SB, and Cr+SB completed the required number of repetitions at 70% of 1RM however in PLA they completed the same repetitions at lower intensity (68+3.4%). Participants in PLA, Cr, SB, and Cr+SB completed 8(±1.6), 11(±5.5), 9(±3.7), and 11(±3.3) repetitions respectively during the 5th set. Despite the fact that no significant differences were observed in performance, small (SB: 0.4) and moderate effect (Cr: 0.7; Cr+SB: 1.0) sizes were observed in relation to PLA. Body mass increasedsignificantly after Cr (78.1±8.9 kg pre vs 79.1±8.9 kg post, p<0.05). No other significant differences existed in recorded variables.Conclusions: Performance gains were of higher magnitude in the Cr+SB and Cr groups. Co-ingestion of a small amount of Cr (5 g/d-1) with a standard dose ofSB (0.5 g/kg-1/d-1)appears to be equally beneficial asingestion of a standard dose of Cr (20 g/d-1). The Cr+SB was not associated with significant gains in body mass which may be beneficial in sports where size gains may negate performance. Further research is required, with larger sample size, and specific athletic populations in order to confirm the findings of the current study

An evaluation of tight-pitch PWR cores

Originally presented as the author's thesis, Ph.D. in the M.I.T. Dept. of Nuclear Engineering, 1979.The impact of tight pitch cores on the consumption of natural uranium ore has been evaluated for two systems of coupled PWR's namely one particular type of thorium system-U-235/U02: Pu/Th02: U-233/ThO2--and the conventional recycle-mode uranium system- U-235/U02: Pu/UO . The basic parameter varied was the fuel-to-moderator volume ratio (F/M) o the (uniform) lattice for the last core in each sequence. Although methods and data verification in the range of present interest, 0.5 (current lattices)< F/M < 4.0 are limited by the scarcity of experiments with F/M > l.0,the EPRI-LEOPARD and LASER programs used for the thorium and uranium calculations, respectively, were successfully benchmarked against several of the more pertinent experiments. It was found that by increasing F/M to "3 the uranium ore usage for the uranium system can be decreased by as much as 60% compared to the same system with conventional recycle (at F/M 0.5). Equivalent savings for the thorium system of the type examined here are much smaller (10%) because of the poor performance of the intermediate Pu/ThO2 core--which is not substantially improved by increasing F/M. Although fuel cycle costs (calculated at the indifference value of bred fissile species) are rather insensitive to the characteristics of the tight pitch cores, system energy production costs do not favor the low discharge burnups which might other- wise allow even greater ore savings (80%). Temperature and void coefficients of reactivity for the tight pitch cores were calculated to be negative. Means for implementing tight lattice use were investigated, such as the use of stainless steel clad in place of zircaloy; and alternatives achieving the same objective were briefly examined, such as the use of D20/H20 mixtures as coolant. Major items identified requiring further work are system redesign to accommodate higher core pressure drop, and transient and accident thermal-hydraulics.DOE Contract no. EN-77-S O2-4570

Quantum Hall conductance of two-terminal graphene devices

Measurement and theory of the two-terminal conductance of monolayer and bilayer graphene in the quantum Hall regime are compared. We examine features of conductance as a function of gate voltage that allow monolayer, bilayer, and gapped samples to be distinguished, including N-shaped distortions of quantum Hall plateaus and conductance peaks and dips at the charge neutrality point. Generally good agreement is found between measurement and theory. Possible origins of discrepancies are discussed