Compatibilization of PP/elastomer/microsilica composites with functionalized polyolefins: Effect on microstructure and mechanical properties

The morphology and mechanical properties of polypropylene/elastomer/silica composites were investigated with the aim of improving stiffness and impact resistance. Two different types of silica were tested: Precipitated silica and polymer grade microsilica (silica fume). The composites were compatibilized with commercial polypropylene and polyethylene containing maleic anhydride functionality as a means of controlling their microstructure and ultimately their mechanical properties. Comparisons were made with surface coated silica and hydroxyl-functionalized copolymers prepared with metallocene catalysts. The effect of adding the polymeric compatibilizers was assessed by morphology studies, thermal analysis and mechanical testing. Significant improvements in impact strength were obtained by tailoring the microstructure of polypropylene/elastomer/microsilica composites. With introduction of PP-g-MAH as compatibilizer, stiffness was enhanced simultaneously with impact strength. DSC curves of crystallization provided evidence to support the formation of different microstructures.     

智能型织物

近年来设计和开发的智能型服装 ,从可穿着计算机型朝着可穿着智能型发展。今天对这一领域的兴趣已经超出了仅仅在服装或其他的结构中放计算机电子元件。在纤维和材料科技领域的开发已获得了新的机遇和挑战。现在的焦点将转移到智能化怎样成为服装功能的一部分上。现代服装不仅要保持传统的服装性能 ,还要创造全新的审美和功能性能 ,以上三个普通的智能领域将用于服装结构 ,其中材料和电子元件将继续开发以满足现代服装的需要。1 998年以来 ,Lapland大学的纺织和时服装设计系和Tampere技术大学一起为服装工业从事开发和设计智能化产品方面进…     

A Stand-Alone CAMAC Crate Controller

An inexpensive stand-alone CAMAC crate controller has been developed. The controller can be programmed to execute up to 256 instructions and CAMAC commands.     

Fourier transform infrared measurement of solid-, liquid-, and gas-phase samples with a single photoacoustic cell

A photoacoustic detector based on the optical cantilever microphone has been built. The detector is capable of measuring solid-, liquid-, and gas-phase samples. Photoacoustic Fourier transform infrared (FT-IR) measurement with three samples in different phases was demonstrated. Example samples were polyethene, sunflower oil, and methane. The sensitivity of the cell was compared to a commercial photoacoustic FT-IR detector. With the standard carbon black sample the cantilever detector gave approximately five times higher signal-to-noise ratio than the reference detector. The sensitivity with methane was also compared to the DTGS detector of the FT-IR instrument corresponding to an absorption path of 6.3 cm. Simulation of the photoacoustic signal showed that a compromise has to be made in the cell design between sensitivity for solid- and gas-phase samples but it is possible to highly enhance the sensitivity for all types of samples by reducing cantilever dimensions.     

Scale-up of manufacturing of printed enzyme electrodes for enzymatic power source applications

Production of printable enzymatic power sources was scaled up from laboratory to roll-to-roll (R2R) pilot production. The anode and cathode enzymes were glucose oxidase (GOx) and laccase, respectively. The best laboratory-scale cells had a maximum power and energy density of 1.4 ± 0.1 µW cm^?2 and 5.5 ± 0.2 µWh cm^?2, respectively. These values are 5 and 28 times higher compared to our previously published values. The R2R-produced cells had a maximum power and energy density of 0.40 ± 0.03 µW cm^?2 and 0.6 ± 0.1 µWh cm^?2, respectively. This is 11 % of the best laboratory manufactured cells. It is suspected that the decrease in electrochemical performance originates from the lower mediator amount and higher drying temperature than that of the laboratory produced cells. However, the trials conducted in this work showed that printed enzymatic active layers can be fabricated and dried with a rotary screen-printing machine in R2R process. Hence, fully printed GOx//laccase power sources could be produced from R2R on a large scale for printed electronics applications.     

Antibodies to varicella zoster virus in the cerebrospinal fluid of neonates with seizures

Four neonates with convulsions had IgG antibodies in their cerebrospinal fluid (CSF) to varicella zoster virus (VZV). These antibodies were found in the sera of two of these patients after the age of 6 months. Antibodies to 16 different microbes were studied from the serum and CSF of 201 neonates with neurological problems. The presence of DNA specific to HSV-1, HSV-2, and VZV in the CSF was also investigated using the polymerase chain reaction (PCR). Antibodies to VZV were detected in the CSF of four neonates. Antibody indices suggested production of VZV specific antibodies in the central nervous system. These findings suggest that intrathecal production of antibodies to VZV can appear in neonates with neurological problems, which suggests that intrauterine VZV infection can be acquired without cutaneous symptoms in the mother.     

Cigarette smoke affects lipolytic activity in isolated rat lungs

Isolated perfused rat lungs liberated fatty acids at a rate of 15 μmol/hr during perfusion of triglyceride-rich medium through the pulmonary vascular bed. About 80% of this activity seemed to result from lipoprotein lipase and 20% to hormone-sensitive lipase. Ventilation of the lungs with cigarette smoke instead of air during the perfusion reduced fatty acid liberation by 23%. Pre-exposure of rats to cigarette smoke for either 1 or 10 days did not cause significant changes in lung lipolytic activity compared to sham-exposed controls.     

The total peroxyl radical-trapping ability of plasma and cerebrospinal fluid in normal and preeclamptic parturients

Plasma and cerebrospinal fluid total peroxyl radical-trapping antioxidative parameter (TRAP) and the main antioxidant components of TRAP (vitamin E, ascorbic acid, uric acid, protein sulfhydryl groups, and the unidentified antioxidant proportion) were analyzed in 11 preeclamptic parturients, 9 healthy parturients with an uncomplicated pregnancy, and 10 healthy nonpregnant women. In addition, the possible effects of ongoing labor were studied in 10 healthy parturients. The samples of plasma and cerebrospinal fluid (CSF) were collected at cesarean section (pregnant women) or minor surgical procedure (nonpregnant women). Normal pregnancy or ongoing labor induced no significant changes in total TRAP, as compared with nonpregnant women, but significant changes in the percentage contributions of individual antioxidants were noted in plasma and CSF. In preeclampsia, a significant increase in TRAP was noted in both plasma and CSF. This increase was mainly due to an increased proportion of uric acid and unidentified antioxidants in plasma samples, and an increased proportion of unidentified antioxidants in CSF. The concentration of CSF ascorbic acid was decreased in preeclampsia, and a negative correlation between CSF ascorbic acid and blood pressure was observed.