General theories for the electrical transport properties of carbon nanotubes

We have shown that the general theories of metals and semiconductors can be employed to understand the diameter and voltage dependency of current through metallic and semiconducting carbon nanotubes, respectively. The current through a semiconducting multiwalled carbon nanotube (MWCNT) is associated with the energy gap that is different for different shells. The contribution of the outermost shell is larger as compared to the inner shells. The general theories can also explain the diameter dependency of maximum current through nanotubes. We have also compared the current carrying ability of a MWCNT and an array of the same diameter of single wall carbon nanotubes (SWCNTs) and found that MWCNTs are better suited and deserve further investigation for possible applications as interconnects.     

Multiple promoters direct stimulus and temporal specific expression of brain-derived neurotrophic factor in the somatosensory cortex

Patients operated on for infective endocarditis (n = 69) at two regional hospitals between 1988 and 1994 are reviewed. 70% had a known valvular heart disease and 16% had prosthetic valve endocarditis. In 28% the offending microorganism was Staphylococcus aureus; in 26% Streptococcus viridans. Therapy was intended to be a six-week antibiotic course before operating, but 55% of the patients had to be operated on earlier. The postoperative course was uncomplicated in 59%, mortality was 16% and one-year survival 81%. Increased risk of death was associated with operating before the six-week course of antibiotics was completed (p = 0.005), with preoperative renal failure (p = 0.006) or lung failure (p = 0.008), with the growth of microorganisms from tissue samples extirpated during the operation (p = 0.01), with additional surgical procedures concomitant to valvular replacement (p = 0.02), S. aureus endocarditis (p = 0.03), and with the presence of paravalvular abscesses or intracardial fistulas (p = 0.03). The study shows that infective endocarditis is a serious disease. Wherever clinically feasible, all patients should be given antibiotics for six weeks before evaluating surgery. However, close surveillance of infection and haemodynamics is necessary to allow for the possibility of acute surgery before the development of organ failure. Special attention must be paid to cases of S. aureus endocarditis.     

A study on osmotic resistance of RBC and ESR in stored blood

The present work was undertaken to study the changes in osmotic resistance of stored blood, used for blood transfusion. Blood samples of 50 cases from Orissa Red Cross Blood Bank, Cuttack, were studied. The blood was collected in acid citrate dextrose solution and stored at 4 degrees C. Storage was done under usual condition followed in blood banks. Osmotic fragility was determined at 3 days interval up to 15 days. In each case ESR was determined and in 20 cases plasma fibrinogen level was determined. In this study there was gradual increase in fragility which was maximum on 9th day and then slowly declined, which was statistically significant. ESR decreased markedly after 6th day, which was also statistically significant.     

In vitro hydrolysis of plant protein concentrate with papain

A method was tested for measuring in vitro papain proteolysis of extracted plant protein to products soluble in trichloroacetic acid. The effects of incubation time, temperature and enzyme concentration were examined. Maximum proteolysis (82.9%) was obtained at 70°C for 24 h and a ratio of papain/protein substrate of approximately 1:10.     

Nonparallelability Constraints in Assembly Lines with Overlapping Work Stations

This paper presents algorithms for designing assembly lines with overlapping work stations where technological limitations may restrict simultaneous performance of certain work elements on the same copy of a product. Computational procedures for the handling of these physical constraints are developed, utilizing techniques from disjunctive graph theory and illustrated with sample problems.     

A heuristic approach to the generation of tests for faults on the intermediate lines

The paper deals with the study of test generation mechanisms for faults on the intermediate lines using Boolean matrices. The proposed technique is a novel approach to the problem and also aims at deriving the results heuristically, thus saving computational effort. The technique has been illustrated by suitable examples.     

Effect of pressure on melting temperature and other associated thermodynamic functions of polyethylene

The melting temperature of polyethylene was determined at pressures up to 30 kbar. Using these results and the calculated values of the volume change on melting in the Clausius–Clapeyron equation, the enthalpy and entropy of fusion as a function of pressure were also determined.     

DRYINC RATES DURING HIGH TEMPERATURE DRYING OF YELLOW POPLAR

Experimental drying rates during high temperature drying of Yellow Poplar is analyzed to determine types of drying mechanism. Drying rate during the constant rate period and effective diffusivity during the falling rate periods were obtained at dryer temperatures ranging from 100°C to 150°C.

The drying curve shows three drying regimes: a constant-rate period, and two falling rate periods. The constant rate period, where the drying rate is a linear function of time, is controlled by the rate of heat transfer to the wood surface. Both falling rate periods show a drying rate which is a linear function of the square root of time. Floisture migration during the first falling rate is by simultaneous capillary action and liquid diffusion. while moisture'migration takes place by vapor diffusion during the second falling rate period. This occurs when the moisture content of the wood falls below the fiber saturation point. The effective diffusion coefficient during both periods is found to be constant.