Charge Transport Calculation along Two-Dimensional Metal/Semiconductor/Metal Systems

Two-dimensional transistors are promising candidates for the next generation of nanoscale devices. Like the other alternatives, they also encounter problems such as instability under standard condition (STP), low channel mobility, small band gaps, and difficulty to integrate metal contacts. The latter poses a great challenge since metal/semiconductor interface significantly affects the transistor‘s performance. Some of these obstacles can be solved by using two-dimensional transition metal di-chalcogenides (TMDC) materials. In this study, we performed charge transport calculation based on density functional theory (DFT) followed by wave dynamics to evaluate the performance of six two-dimensional TMDC metal/semiconductor/metal systems. Each semiconductor monolayer was laterally connected, at both ends to metal contacts consisting of VS₂ or FeS₂ monolayers. We found that charge transport was more efficient in systems containing a CrS₂ semiconductor monolayer compared to systems with MoS₂ or WS₂ as the semiconductor monolayer. The electronic characterization of the monolayer TMDC materials by DFT estimates well the trend in charge transport efficiency calculated using wave packet dynamics.     

Low-cost direct writing lithography system for the sub-micron range

Abstract

We have developed a fixed beam direct writing laser lithography system with a minimum feature size of 400nm at 457nm wavelength and a writing speed of 4·2mm/s with total system costs of less than 100 000 US$.     

The view from the top

The challenge of integrating large amounts of renewable energy resources into the electric sector requires updated transmission analysis techniques. Economic planning, primarily in the form of value-based planning over interconnectionwide areas, is needed before performing the traditional single-hour, capacity-based reliability analyses.     

The teacher's pet phenomenon: Rate of occurrence, correlates, and psychological costs.

The teacher's pet phenomenon was investigated in 80 5th-grade Israeli classrooms. Pets were identified through students' sociometric nominations in 80% of the classrooms: exclusive pets in 26% and unexclusive pets in 54% of the classrooms. Pets tended to be girls rather than boys, of Ashkenazi rather than Sephardi origin, very good (but not necessarily the best) students academically, and perceived as charming, socially skilled, and compliant. Teachers who had pets were found to hold somewhat more authoritarian attitudes than teachers who did not have pets, and the rate of occurrence of the pet phenomenon was higher in religious than in secular schools. Students' affective reactions to their teachers were more positive in classrooms without pets, and most negative in exclusive-pet classrooms. Potential favoritism in assigning teacher grades to exclusive pets was also investigated: No overall favoritism was found, but a trace of favoritism by more authoritarian teachers was discovered. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Teachers' brief nonverbal behaviors in defined instructional situations can predict students' evaluations.

Can a few seconds of high school teachers' nonverbal (NV) behavior predict students' ratings of these teachers (SRT)? Yes, but NV-SRT relations varied among various instructional situations. NV behaviors while administering the class and using the board were unrelated to SRT. Positive judgments of NV behavior while disciplining the class and interacting with students were positively related to SRT. NV behaviors in frontal teaching were negatively related to SRT. The most negative NV-SRT relations were found for teachers' differential NV behavior toward high- versus low-achieving students. Teacher differentiality and SRT have rarely been investigated in high school. The structure of SRT seems to differ between high school and college, and students' anger about teachers' differentiality strongly predicted their evaluations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Endoscopic injection of botulinum toxin for biliary sphincter of Oddi dysfunction

A 66-year old man was admitted to our hospital because of vomiting, diarrhea and progressive dyspnea. Acute respiratory distress syndrome (ARDS) due to bilateral pneumonia was diagnosed and he was also in septic shock. The patient had a history of partial hepatectomy for hepatoma, and suffered from liver cirrhosis. Emergency bronchoalveolar lavage (BAL) revealed abundant gram-positive cocci and polymorphonuclear leukocytes in the collected sample. Blood culture revealed corynebacterium. Treatment consisted of mechanical ventilation and administration of fluids, effective antibiotics, and high-dose methylprednisolone (MPS). MPS was administered from the onset of ARDS with a starting dose of 1,000 mg, which was gradually reduced to 60 mg over 8 days. Pulmonary infiltrates shown on the chest X-ray film were alleviated, and arterial blood gas data rapidly improved. The patient was successfully extubated on the 10th hospital day, and discharged on the 30th hospital day. Serial BAL and plasma levels of inflammatory cytokines decreased rapidly in parallel with the improvement of the patient's clinical condition. This is a case report of severe bacterial pneumonia that was successfully treated with effective antibiotics and high-dose MPS for several days from the onset of ARDS.     

Sonographic detection of focal changes in the liver hilus in patients receiving corticosteroid therapy

OBJECTIVE: While diffuse deposition of fat may occur with corticosteroid (CS) administration both in the liver and in other organs, comparatively little is known about focal changes in the liver under corticosteroid medication. Therefore, we evaluated pattern and extent of focal hepatic steatosis by ultrasound (US) in patients receiving corticosteroids. SUBJECTS AND METHODS: 93 patients with known inflammatory bowel disease (IBD) received corticosteroids during a period of at least six weeks prior to the ultrasound examination and 28 IBD-patients had no corticosteroids within the last three years. 13 additional patients received corticosteroids for other reasons than IBD for > 1 year. 80 healthy volunteers served as controls. Focal changes of the liver as assessed by high resolution ultrasound (Acuson 128, 3.5 and 5 MHz) were defined as areas of brighter echogenicity compared to the general aspect of the liver. The size of the hyperechoic areas was documented (photoprint). RESULTS: 40/93 IBD-patients with corticosteroids (43%) had definite areas of brighter echos in the hilus region of the liver. In IBD-patients without corticosteroids only one patient showed a focal brighter echogenicity, whereas in the non-IBD group with corticosteroids 8/13 had focal lesions (62%). In the control group only four healthy subjects showed brighter areas (5%). CONCLUSION: Bright focal areas in the liver hilus occur in > 40% of IBD-patients during corticosteroid medication. This phenomenon occurs in IBD-patients as frequently and as intense as in other patients with longstanding corticosteroid therapy. There is a hilar area of the liver with typical size and location which reacts to corticosteroid administration with hyperechoic reflexes at ultrasound investigation. This is important to know when it comes to the differential diagnosis of focal changes.     

Pygmalion, Galatea, and the Golem: Investigations of biased and unbiased teachers.

Examined differential expectancy effects as a function of teachers' susceptibility to biasing information and the distinction between positive ("Galatea") and negative ("Golem") outcomes of teacher expectancies. 26 biased and unbiased student teachers were identified on the basis of their susceptibility to biasing information in scoring drawings allegedly made by high- or low-status students. High-bias teachers treated the students they perceived to be of low potential negatively while at the same time treating randomly selected students in a manipulated high-expectancy group as favorably as they treated the students they themselves nominated as being of high potential. Unbiased teachers treated all 3 groups of students (N?=?202) equitably. The strongest and most consistent Golem effects were observed for behavioral manifestations of dogmatism. These patterns of differential negative expectancy effects were evident not only in teachers' behavior but also in students' actual performance of specially designed tasks. (27 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

“Dry latex.” A new method for the preparation of rubber-filler powders

A new method of preparing rubber powders, especially masterbatch powders, is described. It consists of the dispersion of polymer latices in highly hydrophobic fine particle-size powders such as special silicas and carbon black, followed by drying. During the whole procedure the powders never lose their pourable state. Several powder properties, e.g., particle size distribution, pourability, bulk density, and angle of repose, are dealt with for NR and SBR powders. These powders require a high shear processing stage to disperse the black and rubber chemicals into the rubber matrix. For direct extruder feeding, a highly efficient extruder mixing screw is necessary. It is shown that the powders can be sufficiently protected against aging by use of special antioxidants. The procedure is characterized by an outstanding simplicity in respect to engineering and equipment. The future outcome of the method will depend on the balance between that simplicity and the energy demand which can be tolerated.