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Notes: Bi12(GaxBi1−x)O19.5 (BGaO) films with thickness in the range 100–1000 nm have been deposited on (100) Y-stabilized zirconia (YSZ) and (100) Bi12GeO20 (BGO) substrates using a KrF excimer pulsed laser and polycrystalline targets with composition x=0.63–0.72. The laser power density threshold for ablation of the targets has been determined to be J0=4.8 J/cm2. A deposition rate of 0.03 A(ring)/pulse was found for the substrate-target distance (6 cm) and laser fluence (J=7 J/cm2) used. Transparent and crystalline films were obtained heating the substrate in the 450–550 °C range under 1.5×10−1 mbar of oxygen pressure. Films deposited on hot substrates have a Ga stoichiometry x=0.5 but a Bi content slightly lower than that corresponding to sillenite. Films deposited on YSZ show preferential orientation. From the x-ray diffraction results and the comparison of the ionic distributions, it has been concluded that the most likely orientation between both lattices is 〈310〉{130}BGaO(parallel)〈011〉{100}YSZ. A {100}BGaO(parallel){100}BGO epitaxy has been inferred from Rutherford backscattering analysis. On both substrates the films behave as step waveguides with refractive index close to the value determined in bulk BGaO. © 1996 American Institute of Physics.

Notes: A detailed study of bipolar transport under forward-bias conditions is evaluated by Ensemble Monte Carlo simulation in two structures (p+n and pn+ junctions). The static characteristics of both structures are presented. In particular, this study focuses on a microscopic analysis of current fluctuations. A decomposition of the autocorrelation function of the total current fluctuations in electron, hole and crossed contributions is performed. In this way, the importance of each type of carrier in the spectral density of current fluctuations in both structures for a wide frequency range is determined. In the low frequency range, the presence of shot, thermal and excess noise was found. The Ensemble Monte Carlo method also permits ready evaluation of the noise equivalent temperature in both structures. © 1996 American Institute of Physics.

Notes: KTiOPO4 (KTP) samples heated in vacuum at temperatures in the 400–650 °C range show a broad optical absorption similar to that observed by H2 reduction. The position of the maximum depends on the reduction degree. The transparency of the sample is recovered by heating in air at high temperature (600 °C). Vacuum annealing leads to the reduction of Ti4+ to Ti3+ and also to the reduction of Fe, W, and Rh impurities present in the samples, as inferred from electron paramagnetic resonance measurements. X-ray irradiation at 15 K induces an optical absorption peaking at 585 nm. This absorption has been ascribed to the superposition of the 2T2→2E transition of Ti3+ in the two different Ti sites of the lattice. It is suggested that the absorption observed in vacuum-reduced samples consists of the overlapping of the latter contribution and a charge transfer band of Fe-Ti pairs. A loss of K and P ions has been observed after the annealing of KTP in vacuum at 800 °C forming a surface layer that scatters light. Moreover, the K and P loss decreases the optical absorption induced at lower temperature (T〈650 °C). © 1994 American Institute of Physics.

Notes: AbstractFor many firms, entering into some form of collaborative arrangement with other organizations has become a necessary step towards improving their competitive positions. This is particularly true of research intensive companies which frequently participate in such strategic alliances (SAs). This paper reports on the experiences of some 70 North American firms with SAs in the biotechnology industry. The sample includes small dedicated biotechnology companies (DBCs) and large organizations, such as pharmaceutical firms.

Notes: A Monte Carlo analysis of bipolar transport and voltage fluctuations in a p+-Si/n-Si0.7Ge0.3 heterojunction and in a p+n Si homojunction under different operation regimes is presented. Comparison of the spectral density of voltage fluctuations at low frequency, SV(x,0), between both structures reveals the strong effect of the SiGe layer on the noise behavior in the heterojunction. Alloy scattering hinders the electron mobility enhancement expected from the removal of valley degeneracy in the SiGe layer. Despite this mobility reduction, the greater accumulation of carriers in the low-doped region supported by the valence band discontinuity reduce SV(x,0) in the heterojunction for a given average voltage. This study also reveals the impact of hot carriers on noise performance in the quasisaturation regime of both diodes. © 2000 American Institute of Physics.

Notes: Nd-doped LiNbO3 films have been prepared on (012) sapphire substrates by pulsed laser deposition. LiNbO3 phase is formed using Li rich targets, a 1.5×10−2 mbar oxygen pressure atmosphere, and heating the substrate to 520 °C. The crystallinity of 1-μm-thick films has been enhanced by postdeposition thermal treatments at 600 °C. The [Nd]/[Nb] concentration ratio in the film is equal to its value in the target; however, a limit for the Nd incorporation to the LiNbO3 phase has been found due to the preferential nucleation of Li deficient phases for [Nd]/[Nb]〉0.1. The Nd photoluminescence of the films have been studied at 77 K exciting the 4F3/2 multiplet. The photoluminescence of congruent LiNbO3 single crystals is well reproduced in films prepared from targets with a [Li]/[Nb]=1.6 composition. Films prepared from targets with a [Li]/[Nb]=3 composition, additionally show an emission, with a main maximum at 1064 nm, the splitting of the 4F3/2 multiplet being 80 cm−1. The possible origin of the latter photoluminescence is discussed. © 1997 American Institute of Physics.

Notes: An ensemble Monte Carlo (EMC) simulator has been used to study bipolar transport in silicon p+n and pn+ homojunctions under forward-bias conditions, both in low- and high-injection regimes. The study focuses on a microscopic analysis of voltage fluctuations in such devices. The method of voltage-noise operation mode provides spatial analysis of the spectral density of voltage fluctuations under constant-current conditions. In the low-frequency range, the presence of shot, thermal, and excess noise due to hot carriers was found when the bias conditions were modified. Also, the EMC method permits ready evaluation of the noise equivalent temperature in both structures from the observed voltage fluctuations. © 1997 American Institute of Physics.

Notes: Summary.  Factor V deficiency is a rare hereditary bleeding disorder. Currently, FV concentrates are not available, and the treatment of spontaneous bleeding or bleeding associated with invasive procedures is transfusion of fresh frozen plasma (FFP). However, FFP transfusion can lead to the development of inhibitor to FV, and is associated with several potential transfusion reactions including allergic reactions. We report a patient with congenital severe FV deficiency with repeated haemarthroses of a shoulder joint, and progressively severe allergic reactions to FFP transfusions. In addition, the patient also developed acute pulmonary oedema. Activated recombinant coagulation factor VII (rFVIIa) was used as an alternative haemostatic agent to FFP. We describe the use of rFVIIa in this patient during haemarthroses, synovectomy, and physiotherapy.

Notes: A study has been made of the effect of properties and composition of soils on the adsorption of ethofumesate. Adsorption isotherms of ethofumesate by agricultural and natural soils and by montmorillonite and humic acid were obtained. The correlations between the Freundlich K constants, and Kd distribution coefficients and the soil parameters were determined. Significant correlations (P〈0.05) were found between K and clay content and between Kd and smectite content for the agricultural soils but the correlation with organic matter content was of borderline or no significance.Considering the agricultural and natural soils together or the soils with an organic matter content 〉2%, a highly significant correlation was found between K and the organic matter content. According to the r2 determination coefficient, the organic matter content accounts for 88.4% of the variability in adsorption in the first case, and 92.2% in the second case. The log10 Kdom values of soils with an organic matter content 〉2% were similar and confirm the importance of the organic matter as a determinant parameter in the adsorption of ethofumesate by these soils. The adsorption of the herbicide by montmorillonite and humic acid confirmed the results obtained with the soils and point to the importance of the exchangeable cation nature of the samples and of the temperature in the adsorption process. Adsorption de l'éthofumesate dans des sols agri-coles et naturels L'effet des propriétés et de la composition du sol sur l'adsorption de l'ethofumesate a étéétudié. Les isothermes d'adsorption de 1'éthofumesate par des sols agricoles et naturels ainsi que par la montmorillonite et des acides humiques ont été déterminés. Les corrélations entre les caractéris-tiques du sol, les constantes de Freundlich K d'une part et les coefficients de distribution Kd d'autre part ont été déterminées. Des corrélations significatives (P〈0.05) ont été mises en évidence entre K et la teneur en argile ainsi qu'entre Kd et la teneur en smectite pour les sols agricoles mais la correlation avec la teneur en matisre organique etait tout juste ou non significative.Lorsqu'on considérait les sols agricoles et naturels ensemble ou les sols dont la teneur en matière organique est supérieure à 2%, une corrélation hautement significative existait entre K et la teneur en matière organique. Le coefficient de détermination r2 montre que la teneur en matière organique explique 88.4% de la vari-abilité de l'adsorption dans le premier cas et 92.2% dans le second cas. Le log10 Kdométait similaire pour les sols de teneur en matière organique 〉2%, ce qui confirme l'importance du paramètre matière organique dans l'adsorption de 1'ethofumesate par ces sols. L'adsorption de I'herbicide par la montmorillonite et les acides humiques a confirmé les résultats obtenus avec les sols et a montre 1'importance de la température du process et de la nature des cations d'échange des échantillons. Adsorption von Ethofumesat in Acker- and natürlichen Böden Bei der Untersuchung der Wirkung der Eigen-schaften und der Zusammensetzung von Böden auf die Adsorption von Ethofumesat wurden Adsorplions-Isothermen mit Acker- und natürlichen Böden sowie mit Montmorillonit und Huminsäure ermittelt. Die Korrelationen zwischen den Freundlich-Konstanten K sowie den Verteilungskoeffizienten Kd und den Bodenparametern wurden bestimmt. Signifikante Korrelationen (P〈0.05) wurden für K und den Tongehall und für Kd und den Smectit-Gehalt in Ackerböden gefunden, doch die Korrelation mit dem Gehalt an organischer Substanz war marginal oder nicht signifikant. Für Acker-und natürliche Böden insgesamt oder Böden mit einem Gehalt an organischer Substanz von 〉2% wurde eine hochsignifikante Korrelation zwischen K und dem Corg.-Gehalt gefunden. Das Bestimmtheitsmaß (r2) für die organische Substanz lag swischen 88.4% im ersten und 92.2% im zweiten Fall. Die log10Koc-Werte Böden mit einem Corg.-Gehalt von 〉2 % waren ähnlich und bestätigen die Bedeutung der organischen Substanz als bestimmenden Parameter für die Adsorption von Ethofumesat in diesen Böden. Die Adsorption des Herbizids an Montmorillonit und Huminsäure unterstreichen die an den Böden gewonnenen Ergebnisse und die Bedeutung der Kationen-Austauschfähigkeit der Proben.

Notes: Abstract: The effects of power-frequency magnetic fields on nighttime plasma melatonin were studied in a group of 30 adult male human subjects. Exposure consisted of 20 μT (200 mG) at 50 Hz (circularly polarized) at certain times in relation to the predicted time of onset of rise in melatonin concentration for a particular individual (the time of onset was predicted from a previous screening night). Response to this exposure was compared to sham-exposure (in random order). When exposure preceded onset of rise, a significant delay in onset time relative to sham-exposure of approximately half an hour was observed, with indications (marginally significant) of a reduction in maximum melatonin level. Analysis of distribution of time-delays is consistent with two populations: those individuals who respond (around 20%) and those that do not. Magnetic fields generated by square-wave currents produce more marked reductions in the maximum level when compared to sinusoidal waveforms, but there was no significant difference in onset time.