Simulation, design and fabrication of large area implanted silicon two-dimensional position sensitive radiation detectors

The fabrication process of a two-dimensional position sensitive radiation detector (2-D PSD) with a 4 cm2 active area is presented. Critical steps in the fabrication are emphasised. Edge effects represent critical problems in producing large area ion implanted silicon radiation detectors with low leakage currents and a high breakdown voltage (BV). Two methods have been used to increase the breakdown voltage of the junction: the use of i) floating field limiting rings (FFLR) and ii) field plates (FP). Several situations have been simulated analytically and numerically. A comparison of the theoretical results with the measurements realised using the detectors is presented. It is shown that a substantial improvement in the BV of the detector can be achieved by these methods

Fiber association and network formation in PLA/lignocellulosic fiber composites.

PLA composites were prepared in an internal mixer with a lignocellulosic fiber having relatively large aspect ratio. Fiber content changed between 0 and 60 vol% and the homogenized material was compression molded to 1 mm thick plates. The composites showed anomalous behavior above certain fiber content. Their modulus and especially their strength decreased drastically and modeling also proved the loss of reinforcement at large fiber contents. Micromechanical testing showed that the mechanism of deformation and failure changes at a critical fiber content. Microscopic analysis indi-cated the formation of a network purely from geometrical reasons. The inherent strength of the network is very small because of the weak forces acting among the fibers. This weak inherent strength makes the structure of the composites very sensitive to pro-cessing conditions, and decreases strength, reproducibility as well as reliability

Selectivity of the oriental fruit moth sex pheromone trap in peach and apricot orchards

One of the most important pests of the stone fruit orchards is the oriental fruit moth (Grapholitha 1110/esta B.). Chemical control targeted against the young larvae is the most effective way of protection. so the ti ming of treatments has to be based on the observation of emergence. Emergence may be monitored with sex pheromone traps. It is already known from former publications, that the traps for oriental fruit moth are also effective in the case of the plum moth (Grapholitha f1111ebra11a Tr.), which external morphology is very similar to the oriental fruit moth. As the emergence of the oriental fruit moth in peach and apricot orchards has not been observed in detaib in Hungary, we started a s1Udy in this field. Our aim was to measure the selectivity of the sex pheromone traps. On the basis of examining more than 5000 males caught and the investigation of male genital ia. it could be established that the pheromone traps. Csalomon and Deltastop, for oriental fruit moth, caught the plum moth in the same ratio. The ratio of the oriental fruit moth and the plum moth trapped in the peach orchards was I: I . while in the apricot orchards the number of the caught plum moth males was seven times as many as that of the oriental fruit moths. Consequently, it can be established that data based on oriental fruit moth trap catches can not be used without additional investigations of genitalia for the prediction of larval hatch. The selectivity of the plum moth trap. used as a control. was acceptable in both orchards

Performance of traps baited with pear ester-based lures vs. pheromone baited ones for monitoring codling moth Cydia pomonella L. in Hungary

Traps baited with pear ester + acetic acid were capable of monitoring the codling moth although caught fewer specimens than pheromone baited traps. The general flight patterns recorded in pear ester + acetic acid baited traps resembled closely those recorded with pheromone traps. The only aspect in which pear ester + acetic acid baited traps lagged behind was early detection of first moth specimens occurring in the season. The great advantage of traps with pear ester + acetic acid over pheromone traps was that the former caught females in a high percentage. Further studies are needed to determine whether the sex ratio recorded in captures resembles reliably the natural sex ratio of the given population, or it is distorted. It appears that traps baited with pear ester + acetic acid present a useful alternative for monitoring codling moth especially in mating disruption treated orchards where pheromone traps do not work, or in any other situations where for any reason the capture of female codling moths is sought for. The lower efficiency of the pear ester + acetic acid bait can easily be overcome by applying more traps for monitoring at a given site

Pear ester based lures for the codling moth Cydia pomonella L. — A summary of research efforts in Hungary

For acceptable capture efficiency it was necessary to add acetic acid to pear ester for successful trapping of codling moth populations in Hungary. The activity of pear ester on its own was very weak and unsatisfactory. Pear ester+acetic acid baited traps caught on an average 25% (mean of 6 tests) of the catch in pheromone traps. Traps with pear ester+acetic acid were clearly advantageous as compared to pheromone traps in that they caught not only males but also females (both virgins and mated) in a high percentage. Traps baited with pear ester+acetic acid clearly outperformed high-load pheromone lures in orchards with mating disruption and should be the right choice for the grower for sampling populations of codling moth in a mating disruption situation. In orchards with no mating disruption the relative inefficiency of pear ester+acetic acid baited traps as compared to pheromone traps can easily be overcome by applying more traps than usual. Thus the overall codling moth numbers caught will become higher and would make any conclusions drawn more reliable. Traps baited with pear ester+acetic acid always caught more when set at the highest branches (3.0–3.5 m) than when set lower (1.5–1.8 m) on trees