A position sensitive ionisation chamber for measurement of fission fragments and medium mass heavy ions

A position sensitive ionisation chamber telescope is described with ΔE_gas---E_gas sections which can measure simultaneously the specific energy loss ΔE, energy E and the position of heavy ion reaction products in the median plane. The position information is derived by having a split ΔE structure and by adopting the pulse division method for the signals collected by the two ΔE sections. For on-line angle calibration, the E-part of the anode structure is also split into five segments. The detector was tested with fission fragments from a ²⁵²Cf spontaneous fission source and with heavy ions from the pelletron tandem accelerator. Simultaneous measurement of ΔE and E gives good separation for heavy and light fission fragment groups. The position resolution is found to be 1.1 mm for fission fragments. The detector has been used in heavy ion reaction studies for measuring fission fragments, providing good separation from projectile-like particles.     

Design of exclusive or sum-of-products (ESP) logic arrays with universal tests for detecting stuck-at and bridging faults

The detection problem of bridging faults in AND-EXOR arrays is considered in this paper in a new framework. These AND-EXOR arrays are different from the arrays based on the so-called Reed-Muller canonic (RMC) expansion of functions. The multiple stuck-at fault detection test set in such arrays as already derived by Pradhan[1] has been utilized to detect bridging faults. One most important advantage of this test set is that it is independent of the function realized and it has a simple algebraic structure and hence can be generated easily. As this conventional test set is insufficient to detect all bridging faults, we propose a technique of augmenting the network with some additional observation points which take care of otherwise undetectable bridging faults.     

Viscosity variation of N-cetyl pyridinium chloride—high concentration range

N-cetyl pyridinium chloride in aqueous solution is found to obey the equation of fluidity, lnη_rel = (kN)/[N₀(N₀ ? N)] up to a high concentration, almost saturation. Despite micellar association the plot of ln η_relvsN/(N₀ ? N) was found to be linear for N₀ = 5.0, the hypothetical concentration at which glass transition would occur. The linearity of the plot is maintained in the presence of an added electrolyte, sodium chloride producing lower values for N₀ as the concentration of sodium chloride is increased.     

The scanning optical microscope (extracts on near-field microscopy)—from a 1975 report

The following consists of extracts concerning near-field microscopy from a Progress Report prepared in April 1975 as Oxford University Engineering Laboratory Report No. 1883/77, describing work initiated by the late Professor R. Kompfner. Preliminary experimental work on near-field microscopy is outlined, and a theory for contrast formation is presented.     

Soft Error Rate Reduction Using Circuit Optimization and Transient Filter Insertion

This paper describes a tunable transient filter (TTF) design for soft error rate reduction in combinational logic circuits. TTFs can be inserted into combinational circuits to suppress propagated single-event transients (SETs) before they can be captured in latches or flip-flops. TTFs are tuned by adjusting the maximum width of the propagated SET that can be suppressed. A TTF requires 6–14 transistors, making it an attractive cost-effective option to reduce the soft error rate in combinational circuits. A global optimization approach based on geometric programming that integrates TTF insertion with dual-V _DD and gate sizing is described. Simulation results for the 65 nm process technology indicate that a 17–48× reduction in the soft error rate can be achieved with this approach.     

An empirical approach towards characterization of encrypted and unencrypted VoIP traffic

Multimedia Tools and Applications - VoIP traffic classification plays a major role towards network policy enforcements. Characterization of VoIP media traffic is based on codec behaviour. With the...     

Metabolism and pharmacokinetics of 1-(2''-trimethylacetoxyethyl)-2-ethyl-3-hydroxypyridin-4-one (CP117) in the rat

A modified endoscopic technique for anterior cruciate ligament (ACL) reconstruction using an autologous patellar tendon graft is described using the early results for 120 patients. A special technique using an oscillating hollow saw allows for the rapid and standardized harvest of cylindrical bone plugs, ensuring safe and adequate femoral press-fit fixation. The complications encountered included one fracture of a bone back on plugging in as well as two cases with revision procedures for interference screw fixation due to insufficient femoral anchorage. Within the framework of a prospective study, all 120 patients underwent a control arthroscopy after the first postoperative year showing viable and mechanically stable grafts in 64 (53.3%) of the patients. In 44 patients (36.7%), viable though somewhat lax grafts were found, whereas the remaining 12 patients (10%) only showed insufficient tissue residues. All of these cases were the result of a ventral misplacement of the femoral insertion site representing the primary complication of transtibial technique. The results of the control arthroscopies showed a highly significant correlation with the clinical results for the IKDC score obtained in a follow-up after an average 29 (18 to 36) months. The results for stability according to the IKDC rating scale showed a normal or near-normal knee function in 76.7%. With regard to the subjective results in the IKDC rating scale, 83.3% of the patients (n = 100) assessed their knee function as normal or almost normal. The location and positioning of the femoral and tibial tunnel were evaluated in an exact radiographic evaluation showing an "ideal position" of the graft in only 94 cases (78.3%). Statistically, a significant correlation of stability with the femoral fixation site could be shown.