The elastic constants of antimony-25.5 at. % arsenic alloy single crystals

The six independent elastic constants of single crystals of the homogeneous, minimum melting point alloy of composition antimony 74.5 at. % and arsenic 25.5 at. % have been measured. The elastic behaviour of the alloy is compared with that of the rhombohedral A7 structure elements arsenic and antimony and is found to show characteristics consistent with those expected for layer-type crystals. Elastic wave velocity surface cross-sections, particle displacement and energy flux vectors and Young's modulus are presented and discussed. The Debye temperature is 219 K.     

Thyroid carcinoma after high-dose external radiotherapy for Hodgkin's disease: report of three cases

Three patients (two female and one male), who had received mantle irradiation for Hodgkin's disease eight, ten, and twelve years previously, developed papillary thyroid carcinoma. The radiation doses to the necks overlying the site of thyroid cancers were 3000, 4000, and 4100 rads, respectively. It has been stated that there is no risk of developing thyroid cancer with such high doses of external irradiation but apparently this complication will be encountered in a small number of patients.     

Doses to fetal and maternal organs from intravenous 59FeCl3 or 57CoCl2

Doses from intravenous intakes of 59Fe or 57Co chloride during pregnancy were estimated. Near term fetal organ doses were derived via the MIRDOSE3 newborn phantom, with mean dose/cumulated activity (S) values rescaled for compatibility with near term fetus whole body S. A detailed in vivo biodistribution database provided indications of residence times in important maternal and fetal organs. 59Fe doses to the fetus whole body from early to late pregnancy were 7-11 mGy MBq(-1) (8.5-14.3 mSv MBq(-1)), similar to that to the mother. Doses to near term fetal spleen (59 mGy MBq(-1)), liver (36), and red marrow (9) were similar or higher than to the mother. 57Co doses to fetus whole body from early to late pregnancy were 0.7-3.3 mGy MBq(-1) (2.5-8.2 mSv MBq(-1)), similar or higher than to the mother. Doses to near term fetal small intestine (34 mGy MBq(-1)). liver (4.7) and red marrow (2.7) were similar or higher than to the mother.     

Experimental observation of rainbow scattering by a coated cylinder: twin primary rainbows and thin-film interference

We experimentally examine the primary rainbow created by the illumination of a coated cylinder. We present a simple technique for varying the coating thickness over a wide range of values, and we see evidence for two different scattering regimes. In one, where the coating thickness is large, twin rainbows are produced. In the second, where the coating is thin enough to act as a thin film, a single rainbow is produced whose intensity varies periodically as the coating thickness varies. We find good agreement with previous theoretical predictions.     

Solving shortest paths efficiently on nearly acyclic directed graphs

Shortest path problems can be solved very efficiently when a directed graph is nearly acyclic. Earlier results defined a graph decomposition, now called the 1-dominator set, which consists of a unique collection of acyclic structures with each single acyclic structure dominated by a single associated trigger vertex. In this framework, a specialised shortest path algorithm only spends delete-min operations on trigger vertices, thereby making the computation of shortest paths through non-trigger vertices easier. A previously presented algorithm computed the 1-dominator set in O(mn) worst-case time, which allowed it to be integrated as part of an O(mn+nrlogr) time all-pairs algorithm. Here m and n respectively denote the number of edges and vertices in the graph, while r denotes the number of trigger vertices. A new algorithm presented in this paper computes the 1-dominator set in just O(m) time. This can be integrated as part of the O(m+rlogr) time spent solving single-source, improving on the value of r obtained by the earlier tree-decomposition single-source algorithm. In addition, a new bidirectional form of 1-dominator set is presented, which further improves the value of r by defining acyclic structures in both directions over edges in the graph. The bidirectional 1-dominator set can similarly be computed in O(m) time and included as part of the O(m+rlogr) time spent computing single-source. This paper also presents a new all-pairs algorithm under the more general framework where r is defined as the size of any predetermined feedback vertex set of the graph, improving the previous all-pairs time complexity from O(mn+nr²) to O(mn+r³).     

The Hysteresis Characteristics of Some Industrial PRTs

Hysteresis in industrial platinum resistance thermometers (IPRT) is caused by tension and compression induced in the wire due to differential thermal expansion of the platinum wire and the substrate. This article reports the measurement of hysteresis in a wide range of IPRTs including thin-film, glass-encapsulated, ceramic-encapsulated, and low-hysteresis partially-supported sensors, over the temperature range from ?20 °C to 180 °C. The study confirms previous findings that the amount of hysteresis is very dependent on the design of the sensing element and the temperature range. In addition, some sensors exhibit a large change in resistance on first use, whereas others showed a slow increase in resistance with use. The observed hysteresis ranged between 0.2 % of the temperature range for one glass-encapsulated sensor and 0.002 % for the best of the partially-supported ceramic sensors.