摘要 :
The present paper reports on modelling and numerical simulation of thin-walled structures close to failure taking into consideration the effects of both geometrical and physical nonlinearity. The approach accounts for finite displ...
展开
The present paper reports on modelling and numerical simulation of thin-walled structures close to failure taking into consideration the effects of both geometrical and physical nonlinearity. The approach accounts for finite displacements and rotations, and the material model adopted includes elastic-plastic behaviour, isotropic and kinematic hardening, and ductile damage. Particular attention is paid to the problems of localised damage, damage progression and final collapse of the structure.
收起
摘要 :
Secondary hospital wastewatcr treatment was investigated as an alternative to detoxification and disinfection after anaerobic digestion in a hospital located in southern Brazil. Tertiary and secondary effluents were assessed by ge...
展开
Secondary hospital wastewatcr treatment was investigated as an alternative to detoxification and disinfection after anaerobic digestion in a hospital located in southern Brazil. Tertiary and secondary effluents were assessed by general parameters. The use of advanced oxidation processes (UV/O_3 and UV/TiO_2/O_3) showed potential capacity for disinfection and detoxification of wastewater effluents. The UV/TiO_2/O_3 method yielded the best results, decreasing toxicity of EC_(50) = 65 to nontoxic levels, also reducing MPN/100ml of 1.1 × 10~6 to values less than 2 and increasing wastewater biodegradability. The low energetic consumption of the proposed UV/TiO_2/O_3 method can be considered operationally advantageous.
收起
摘要 :
A mild and efficient procedure has been developed to obtain covalently attached self-assembled mono-layers (SAMs) on Si(111) with photochromic azobenzene head-groups. Starting from neat or diluted carboxylic acid functionalized mo...
展开
A mild and efficient procedure has been developed to obtain covalently attached self-assembled mono-layers (SAMs) on Si(111) with photochromic azobenzene head-groups. Starting from neat or diluted carboxylic acid functionalized monolayers on-chip coupling reactions were applied to attach hydroxyl-functionalized azobenzene units to the SAMs by ester bond formation. The modified surfaces were characterized by high-resolution X-ray photoelectron spectroscopy (XPS), transmission Fourier transform infrared spectroscopy (FT-IR), and contact angle measurements. Reversible cis reversible trans isomerizations of photo-switchable SAMs were monitored by wettability measurements.
收起
摘要 :
1. Repeatability and reproducibility coefficients of variation for myrcene ranged from 0.6 to 3.4% and from 4.2 to 7.1%, respectively, and were judged acceptable. 2. Repeatability and reproducibility coefficients of variation for ...
展开
1. Repeatability and reproducibility coefficients of variation for myrcene ranged from 0.6 to 3.4% and from 4.2 to 7.1%, respectively, and were judged acceptable. 2. Repeatability and reproducibility coefficients of variation for 2-methyl-butyl isobutyrate ranged from 1.8 to 11.2% and from 8.8 to 15.0%, respectively, and were judged acceptable. 3. Repeatability and reproducibility coefficients of variation for linalool ranged from 0.7 to 8.7% and from 2.2 to 11.7%, respectively, and were judged acceptable. 4. Repeatability and reproducibility coefficients of variation for caryophyllene ranged from 0.8 to 2.4% and from 5.3 to 10.2%, respectively, and were judged acceptable. 5. Repeatability coefficients of variation for methyl 4-decenoate ranged from 1.5 to 3.2% and were judged acceptable. 6. Reproducibility coefficients of variation for methyl 4-decenoate ranged from 11.3 to 23.4% and were judged unacceptable. 7. Repeatability and reproducibility coefficients of variation for farnesene ranged from 1.9 to 2.8% and from 4.2 to 10.1%, respectively, and were judged acceptable. 8. Repeatability and reproducibility coefficients of variation for humulene ranged from 0.6 to 3.3% and from 5.1 to 14.8%, respectively, and were judged acceptable. 9. Repeatability coefficients of variation for δ-cadinene ranged from 0.7 to 8.8% and were judged acceptable. 10. Reproducibility coefficients of variation for δ-cadinene ranged from 9.8 to 28.3% and were judged unacceptable. 11. Repeatability coefficients of variation for γ-cadinene ranged from 0.7 to 2.8% and were judged acceptable. 12. Reproducibility coefficients of variation for γ-cadinene ranged from 6.1 to 50.8% and were judged unacceptable. 13. Repeatability coefficients of variation for geraniol ranged from 2.5 to 10.2% and were judged acceptable. 14. Reproducibility coefficients of variation for geraniol ranged from 14.0 to 64.2% and were judged unacceptable. 15. Repeatability and reproducibility coefficients of variation for the humulene-to-caryophyllene ratio ranged from 0.2 to 1.1% and from 2.2 to 10.4%, respectively, and were judged acceptable. 16. Repeatability and reproducibility coefficients of variation for the δ-cadinene-to-γ-cadinene ratio ranged from 0.8 to 3.9% and from 1.4 to 12.2%, respectively, and were judged acceptable.
收起
摘要 :
Splay leg is a hereditary syndrome observed in highly varying frequency in newborn piglets. Although the phenotype indicates a muscular weakness, the etiology is still poorly understood. Only recently, the gene expression of muscl...
展开
Splay leg is a hereditary syndrome observed in highly varying frequency in newborn piglets. Although the phenotype indicates a muscular weakness, the etiology is still poorly understood. Only recently, the gene expression of muscle atrophy F-box (MAFbx: FBXO32) was proposed as being of diagnostic value for splay leg in piglet. In this study, total RNA from three healthy and three affected male piglets was isolated. Samples were collected from M. gracilis, Mm. adductores. and M. sartorius. Further samples were taken for histological and biochemical analyses. Expression of MAFbx was analysed by real-time RT-PCR and with the GeneChip~R Porcine Genome Array (Affymetrix). No significant differences (p > 0.05) were observed in relative MAFbx expression, either between the three muscles or between splay leg and healthy piglets for each muscle. The expression of further atrophy-related genes was unchanged, indicating that splay leg is not characterized by general muscular atrophy in the affected hind limbs. This is supported by histological and biochemical data that does not demonstrate signs of atrophy in splay leg muscles. We conclude that the diagnostic value of MAFbx expression for congenital splay leg in piglets is doubtful and that the disease is characterized by heterogeneous alterations in skeletal muscle.
收起
摘要 :
High performance single-phase Si microchannel coolers have been designed and characterized in single chip modules in a laboratory environment using either water at 22℃ or a fluorinated fluid at temperatures between 20 and -40℃ a...
展开
High performance single-phase Si microchannel coolers have been designed and characterized in single chip modules in a laboratory environment using either water at 22℃ or a fluorinated fluid at temperatures between 20 and -40℃ as the coolant. Compared to our previous work, key performance improvements were achieved through reduced channel pitch (from 75 to 60 microns), thinned channel bases (from 425 to 200 microns of Si), improved thermal interface materials, and a thinned thermal test chip (from 725 to 400 microns of Si). With multiple heat exchanger zones and 60 micron pitch microchan-nels with a water flow rate of 1.25 lpm, an average unit thermal resistance of 15.9 C mm~2/W between the chip surface and the inlet cooling water was demonstrated for a Si microchannel cooler attached to a chip with Ag epoxy. Replacing the Ag epoxy layer with an In solder layer reduced the unit thermal resistance to 12.0 C mm~2/W. Using a fluorinated fluid with an inlet temperature of-30℃ and 60 micron pitch micro-channels with an Ag epoxy thermal interface layer, the average unit thermal resistance was 25.6 C mm~2/W. This fell to 22.6 C mm~2/W with an In thermal interface layer. Cooling >500 W/cm~2 was demonstrated with water. Using a fluorinated fluid with an inlet temperature of-30℃, a chip with a power density of 270 W/cm~2 was cooled to an average chip surface temperature of 35℃. Results using both water and a fluorinated fluid are presented for a range of Si microchannel designs with a channel pitch from 60 to 100 microns.
收起
摘要 :
To improve the acoustic behaviour of vehicles is an increasing challenge for every car manufacturer. The sound pressure at the drivers ear due to an arbitrary excitation of the structure can be calculated by a harmonic analysis fi...
展开
To improve the acoustic behaviour of vehicles is an increasing challenge for every car manufacturer. The sound pressure at the drivers ear due to an arbitrary excitation of the structure can be calculated by a harmonic analysis first of the structure and then of the fluid. Using the concept of influence coefficients one has to carry out the harmonic analysis of the fluid only once to determine the sound pressure at the drivers ear. If the influence coefficients are available one has to solve an easy algebraic relation instead of a full harmonic analysis.
收起
摘要 :
A detailed vibrationally and rotationally resolved study for the fragmentation dynamics of the hydrogen
molecular ion (H2
+) under intense short laser pulses is presented.Our theoretical nonadiabatic quantum molecular
dynamics app...
展开
A detailed vibrationally and rotationally resolved study for the fragmentation dynamics of the hydrogen
molecular ion (H2
+) under intense short laser pulses is presented.Our theoretical nonadiabatic quantum molecular
dynamics approach allows us to dynamically include all degrees of freedom for ionization also. We find that
in general rotation enhances ionization compared to that in rotationally frozen molecules, with a weaker effect
on highly vibrationally excited states. We identify the alignment time of one-quarter of the rotational period
as the parameter which decides the dynamical relevance of rotation. Our analysis explains the dominance of
dissociation over ionization observed experimentally and also clarifies why dimensionally reduced calculations
predict a dominance of ionization.
收起
摘要 :
Femtosecond laser pulses tailored with closed-loop, optimal control feedback were used to excite oscillations in C_(60) with large amplitude by coherent heating of nuclear motion. A characteristic pulse sequence results in signifi...
展开
Femtosecond laser pulses tailored with closed-loop, optimal control feedback were used to excite oscillations in C_(60) with large amplitude by coherent heating of nuclear motion. A characteristic pulse sequence results in significant enhancement of C_2 evaporation, a typical energy loss channel of vibra-tionally hot C_(60). The separation between subsequent pulses in combination with complementary two-color pump-probe data and time-dependent density functional theory calculations give direct information on the multielectron excitation via the t_(1g) resonance followed by efficient coupling to the radial symmetric a_g(l) breathing mode.
收起
摘要 :
The performed investigation on the novel knee concept shows the following potential benefits for a ceramic knee bearing in comparison to conventional total knee prostheses with fixed tibia plateau : i. approx. 500 times lower volu...
展开
The performed investigation on the novel knee concept shows the following potential benefits for a ceramic knee bearing in comparison to conventional total knee prostheses with fixed tibia plateau : i. approx. 500 times lower volumetric wear ii. low risk of tribologically induced failure iii. no PE particle induced osteolysis Knee implants have become an area of great interest in he past years.
收起
