Field and hot carrier enhanced leakage in InGaAsP/InP heterojunctions

A model calculation for the field and hot carrier enhanced electron leakage in InGaAsP/InP LED's and lasers is presented. The significant influence of the doping level in the P-InP confining layer on leakage current is confirmed.     

Cross-cultural demonstration of orthogonality of assertiveness and aggressiveness: Comparison between Israel and the United States.

Compared the responses of 101 Israeli and 97 US college students on the Interpersonal Behavior Survey (IBS), a 272-item self-report inventory. The IBS was translated into Hebrew and tested for translation equivalence. Factor analyses suggested that Ss from both cultures shared similar conceptualizations of assertiveness and aggressiveness, viewing these behaviors as distinct response classes. ANOVA found that Israelis generally responded more aggressively than Americans but did not differ on the global measure of assertiveness. More specifically, Israelis were prone to express anger aggressively, whereas Americans tended to have greater self-confidence. Results demonstrate that cross-cultural differences exist in the amount of assertiveness and aggressiveness but that Israeli and US students both conceptualize these as independent classes of interpersonal behavior. (30 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

High-speed Schottky photodiode on semi-insulating GaAs

A high-speed GaAs photodiode has been fabricated on a GaAs semi-insulating substrate. The photodiode has an active area of 8 ?m × 15 ?m and a bandwidth in excess of 9 GHz. This Schottky photodiodes is suitable for monolithic integration with other optoelectronic components.     

Living with a depressed person.

This study explored the burdens experienced by 42 adults who lived with a depressed patient and related these burdens to their degree of psychological distress. The comparison group consisted of 23 adults who were living with someone who had been an in- or outpatient but who was not currently in a depressive episode. Respondents who were living with a patient in a depressive episode were quite distressed themselves, and over 40% met a standardized criterion for referral for therapeutic intervention. For these respondents, living with a patient currently in a depressive episode produced numerous burdens in response to the patients' symptoms, particularly patients' lack of interest in social life, fatigue, feelings of hopelessness, and worrying. Multiple regression analyses showed that these burdens accounted almost entirely for respondents' greater psychological distress. It is suggested that clinical depression is often indicative of a more generally distressed interpersonal context. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Rate equations analysis of phase-locked semiconductor laser arrays under steady state conditions

Rate equations analysis of phase-locked semiconductor laser arrays has been carried out. It was found that for given (Laser) current densities, the photon density distribution in the array elements is that particular one which maximizes the total photon density. The results of this analysis were then combined with the waveguiding properties of the laser array waveguide, yielding a basic model of phase-locked diode laser arrays. This model explains the effects of the variation of the current combination through the array elements on its mode structure that were observed recently.     

Very low threshold InGaAsP mesa laser

Very low threshold currents InGaAsP/InP terrace mesa (T-ME) lasers with an unpassivated surface have been fabricated on semi-insulating (SI) InP substrates. Fabrication of the lasers involves a single-step liquid phase epitaxial (LPE) growth and a simple etching process. Lasers operating in the fundamental transverse mode with threshold currents as low as 6.3 mA (for a cavity length of 250 μm) have been obtained. Comparison between the unpassivated lasers and those passivated using the mass transport technique is described.     

Noise equivalent circuit of a semiconductor laser diode

The noise equivalent circuit of a semiconductor laser diode is derived from the rate equations including Langevin noise sources. This equivalent circuit allows a straightforward calculation of the noise and modulation characteristics of a laser diode combined with electronic components. The intrinsic junction voltage noise spectrum and the light intensity fluctuation of a current driven laser diode are calculated as a function of bias current and frequency.     

Effects of an upland impoundment on structural and functional properties of a small stream in a basaltic plateau (golan heights,Israel)

The aim of the study was to evaluate the impact of an upland storage reservoir, typical of the series of reservoirs in the Golan Heights basaltic plateau, on structural and functional properties of the downstream ecosystem, in the vicinity of the reservoir, shortly after damming. The effect of impoundment on water quality conditions may be divided into winter-spring, and summer periods. In the former, the impoundment seems to lengthen the period of flow of runoff quality water. This is evident by the elevated winter and spring turbidities and the higher concentrations of suspended solids below the reservoir. In summer, water quality below the reservoir is controlled by the consequences of stratification in the reservoir. The hypolimnial release results in depression of the maximal temperature and narrowing of the daily and seasonal temperature variations. It supplies water enriched in nutrients and low in oxygen, suspended solids and turbidity. The macroinvertebrate community responds to impoundment in density changes and shifting of dominance. We hypothesize that the thermal effect of hypolimnial release from warm monomictic reservoirs on the invertebrate community of warm streams will differ from an equivalent thermal change caused by cold dimictic reservoirs in cold, temperate zone, streams. The effect of impoundment on functional properties of the ecosystem are most pronounced. The rate of production of benthic algae biomass below the reservoir increased by more than two orders of magnitude, but the effect diminished downstream. The rate of processing of plant material below the reservoir was lower than above the reservoir. Further investigation is needed to clarify this effect. Changes in reservoir operation are recommended to diminish the effects of impoundment.     

Metadocuments supporting digital library information discovery

The World Wide Web is a decentralized, unmanaged, dynamically changing repository of digital documents. Waldens Paths provides tools that enable authors to collect, organize, annotate, and present Web-based information to reader communities via a linear metadocument called a path. Waldens Paths includes path authoring and reading interfaces supporting the contextualization of included materials to match authors goals as well as enabling browsing off the path to match readers personal interests. It also provides tools to manage these paths of transient Web materials based on the identification and evaluation of changes to the component pages. Experience with Waldens Paths in educational settings and changes to Web technology as well as the Web-savvyness of users have led to a variety of changes to earlier designs. Current directions of work include the development of methods for evaluating readers understanding via quizzes associated with paths and richer path structures.     

All Pairs Shortest Distances for Graphs with Small Integer Length Edges

There is a way to transform the All Pairs Shortest Distances (APSD) problem where the edge lengths are integers with small (?M) absolute value into a problem with edge lengths in {−1, 0, 1}. This transformation allows us to use the algorithms we developed earlier ([1]) and yields quite efficient algorithms. In this paper we give new improved algorithms for these problems. Forn=|V| the number of vertices,Mthe bound on edge length, andωthe exponent of matrix multiplication, we get the following results: 1. A directed nonnegative APSD(n, M) algorithm which runs inO(T(n, M)) time, where[formula]2. A undirected APSD(n, M) algorithm which runs inO(M^(ω+1)/2n^ωlog(Mn)) time.