Mathematical model for calculating the shaded and sunlit areas in a circular courtyard geometry

This paper presents a mathematical model that was developed specifically to calculate the produced shaded and sunlit areas in a circular courtyard geometry. It examines the interaction taking place between the sun at any time throughout the year and a circular courtyard form with any dimensions and proportions in any place on the earth. This model was included in a new computer program, which allowed detailed investigation to be undertaken into the effect of circular courtyard proportions on the generated wall and floor exposed and shaded areas. The results showed that changing the form's proportions significantly influences the shading or exposure potential of the internal courtyard envelope.     

The relationships between posttraumatic stress symptom clusters and marital intimacy among war veterans.

This study examined (a) the relationships between posttraumatic stress disorder (PTSD) symptom clusters and marital intimacy among Israeli war veterans and (b) the role of self-disclosure and verbal violence in mediating the effects of PTSD avoidance and hyperarousal symptoms on marital intimacy. The sample consisted of 219 participants divided into 2 groups: ex-prisoners of war (ex-POWs; N = 125) and a comparison group of veterans who fought in the same war but were not held in captivity (N = 94). Ex-POWs displayed higher levels of PTSD symptoms and verbal violence and lower levels of self-disclosure than did controls. Although ex-POWs and controls did not differ in level of marital intimacy, they did, however, present a different pattern of relationships between PTSD clusters and intimacy. In ex-POWs, self-disclosure mediated the relations between PTSD avoidance and marital intimacy. Verbal aggression was also found via indirect effect of hyperarousal on marital intimacy. The results point to the importance of self-disclosure and verbal violence as interpersonal mechanisms for the relations between posttraumatic symptoms on marital intimacy of ex-POWs. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Combinatorial Design of Copper‐Based Mixed Nanoclusters: New Catalysts for Suzuki Cross‐Coupling

Quantum dots (2–5 nm) of copper and copper/palladium mixtures are found to be good catalysts for Suzuki cross‐coupling. The catalysts are applicable to a wide range of iodo‐ and bromoaryl substrates, and give moderate yields using chloroaryl substrates. Cluster activity and stability is found to depend strongly on the preparation method and the reaction conditions. The mechanism of cluster deactivation and the sensitivity of the cluster‐catalysed reaction to substituent effects are studied and discussed.     

Tuning the Selectivity of Heterogeneous Catalysts: A Trimetallic Approach to Reductive Coupling of Chloroarenes in Water

Reductive homocoupling of chlorobenzenes to the respective biphenyls affords high yields (93–95%), in the presence of catalytic PEG‐400 and 0.4 mol % of a recycleable, heterogeneous trimetallic catalyst (4% Pd, 1% Pt, and 5% Bi on carbon). The competing reduction process is minimized. The catalytic cycle is completed using hydrogen gas, or formate + water or zinc + water mixtures, which generate dihydrogen in situ. Primary kinetic data and some process parameters are studied. The roles of the Pd, Pt, and Bi, different reducing agents, and the phase‐transfer agent are discussed. The reaction mechanism is proposed to depend on the relative concentration of hydride species in the immediate vicinity of the palladium metal.     

Efficient Sex Pheromone Trapping: Catching The Sweetpotato Weevil, Cylas formicarius

The sweetpotato weevil, Cylas formicarius (Fabricius) (Coleoptera: Brentidae), is the most serious pest of sweetpotato around the world, damaging sweetpotatoes in the field and in storage, as well as being a quarantine pest. Because the larval period is spent within vines or tubers, and the adults are nocturnal, chemical control frequently is not effective. In addition, there are few natural enemies, and pheromone-based trapping does not appear to reduce the damage level. In the present study, we evaluated a number of parameters that affect pheromone-based trap catch, including trap design, trap size, trap color, and height at which the traps are placed. Pherocon unitraps caught higher numbers than ground, funnel water, or delta traps. Medium-sized traps (13?×?17.5 cm) were more effective than larger or smaller traps. In a color-choice test, C. formicarius preferred red over gray, brown, blue, white, yellow, black, or red traps; light red was more attractive than other shades of red. Maximum catches were obtained when the traps were set 50 cm above the crop canopy. Light-red unitraps with pheromone lures caught more adults than identical traps without lures, suggesting that C. formicarius is influenced by both visual and olfactory cues. Pheromone-baited light-red unitraps, 13?×?17.5 cm, installed 50 cm above the crop canopy, were the most effective at catching C. formicarius adults, and they appear to have the greatest potential for use in trap-and-kill strategies and eradication programs.     

Click Chemistry: Copper Clusters Catalyse the Cycloaddition of Azides with Terminal Alkynes

Air‐stable copper nanoclusters are good catalysts in the Cu(I)‐catalysed “click” cycloaddition of azides with terminal alkynes to give 1,4‐disubstituted 1,2,3‐triazoles. No additional base or reducing agent is required. The reaction kinetics using various copper catalyst types and the function of copper particles in this system are studied and discussed.     

Phase-Jitter based SER of MPSK Scheme over Generalised Mixture Gamma Fading

ABSTRACT

Extensive literature exists for simple and exact expressions of symbol error rate (SER) over fading channels under different modulation schemes whose boundaries meet at right angles. In cases where boundaries do not meet at right angles, integrals of special function in the expressions make the exact calculation most complex. In such cases only approximate solutions are possible. Also, it is noteworthy to mention that when detection is performed with proper use of the phase (phase-jitter-based approach), noise performance of the receiver improves significantly. This paper applies phase-jitter PDF-based approach to present exact and closed-form SER expression of MPSK scheme over Mixture Gamma (MG) distribution for an arbitrary array of signal points. The proposed expression is generic as MG distribution can be approximated in almost all fading/shadowed fading channel models. As a proof to the authenticity, SERs of MPSK scheme over Rayleigh and Nakagami-m fading channels are deduced from the proposed SER over generalised MG distribution. Further, a significant improvement in SER has been achieved with phase-jitter-based approach as compared to conventional (non-phase-jitter-based) approach. Finally, to confirm the correctness of the proposed expression, results are validated through comparison with the existing results and Monte Carlo simulation.     

The computability of relaxed data structures: queues and stacks as examples

Most concurrent data structures being designed today are versions of known sequential data structures. However, in various cases it makes sense to relax the semantics of traditional concurrent data structures in order to get simpler and possibly more efficient and scalable implementations. For example, when solving the classical producer-consumer problem by implementing a concurrent queue, it might be enough to allow the dequeue operation (by a consumer) to return and remove one of the two oldest values in the queue, and not necessarily the oldest one. We define infinitely many possible relaxations of several traditional data structures and objects: queues, stacks, multisets and registers, and examine their relative computational power.