Resonant-tunneling oscillators and multipliers for submillimeter receivers

Resonant tunneling through double-barrier heterostructures has attracted increasing interest recently, largely because of the fast charge transport it provides. In addition, the negative differential resistance regions that exist in the current-voltage (I-V) curve (peak-to-valley ratios of 3.5:1 at room temperature, and nearly 10:1 at 77 K, were measured) suggest that high-speed devices based on the character of the I-V curve should be possible. For example, the negative differential resistance region is capable of providing the gain necessary for high-frequency oscillations. In the laboratory attempts were made to increase the frequency and power of these oscillators and to demonstrate several different high-frequency devices

Hydrodesulfurization of dibenzothiophene using CoMoS2

The hydrodesulphurization (HDS) of crude oils is an important industrial process to remove sulfur from fuels. In this study, DBT was used as a model compound to study the removal of sulfur from a decahydronaphthalene solution. The catalyst was synthesized through low pressure pathways in the absence of H2S. All the synthesized catalyst were investigated using a combination of SEM, RAMAN spectroscopy, and XRD. The materials were studied for their ability to remove DBT from solution and the reaction products were analyzed. It was observed that the major reaction pathway was the direct desulphurization pathway and zero order reaction kinetics was observed for the HDS process. Furthermore, a rate constant of 2.3 x 10-6 moles (DBT)/s g (of catalyst) with a final removal above 90% was observed

Psychodynamic approaches to teaching medical students about the doctor-patient relationship: Randomised controlled trial

Aims and method: To evaluate the effectiveness of two psychodynamic psychotherapy teaching methods, a student psychotherapy scheme (SPS) and participation in a Balint group, in teaching first-year clinical medical students about doctor-patient communication and the doctor-patient relationship. The 28 students, who were randomly allocated to three groups (SPS group, Balint group starting at baseline and Balint group starting at 3 months and acting as partial controls), were rated on a questionnaire testing their knowledge of emotional and psychodynamic aspects of the doctor-patient relationship administered at baseline, at 3 months and at 1 year. Results: At 3 months, students in the SPS and Balint groups scored higher than the partial control group, the difference approaching significance at the 5% level. At 1 year, participation in either teaching method led to significantly higher scores compared with baseline. Clinical implications: Psychodynamic psychotherapy teaching methods are effective in increasing students’ knowledge of the doctor-patient relationship and potentially also improving their communication skills