We report the electroactive shape memory composites obtained by shape memory polyurethane block copolymer (PU) and multi-walled carbon nanotubes (MWNTs), and polypyrrole (PPy). An addition of combined MWNTs and PPy contributed to an enhancement in conductivity of PU-MWNTs composites. PU containing 2.5% MWNTs showed better mechanical and thermal properties than other composites, but conductivity was not sufficient for showing the shape memory effect by applying electrical voltages. However, when the composite was lightly coated by PPy (2.5%), its conductivity was the highest than other composites. Such the conductivity of this composite was enough to show electroactive shape recovery by heating above transition temperature of 40-48°C due to melting of polycaprolactone soft segment domain. The good shape recovery of 90-96% could be obtained in the shape recovery test when an electric field of 25 V was applied. 相似文献
To model P2P networks that are commonly faced with high rates of churn and random departure decisions by end-users, this paper investigates the resilience of random graphs to lifetime-based node failure and derives the expected delay before a user is forcefully isolated from the graph and the probability that this occurs within his/her lifetime. Using these metrics, we show that systems with heavy-tailed lifetime distributions are more resilient than those with light-tailed (e.g., exponential) distributions and that for a given average degree, k-regular graphs exhibit the highest level of fault tolerance. As a practical illustration of our results, each user in a system with n = 100 billion peers, 30-minute average lifetime, and 1-minute node-replacement delay can stay connected to the graph with probability 1 - 1/n using only 9 neighbors. This is in contrast to 37 neighbors required under previous modeling efforts. We finish the paper by observing that many P2P networks are almost surely (i.e., with probability 1 - o(1)) connected if they have no isolated nodes and derive a simple model for the probability that a P2P system partitions under churn. 相似文献
To realize embedded resistors on multilayer benzocyclobutene (BCB) either on-chip or on-board, a low-cost large format electroless
process for deposition of NiP and NiWP thin-film resistors using both low-temperature (25°C) and high-temperature (90°C) baths
has been developed. The electroless process exhibits uniform resistor thickness in the submicron range and offers low profile
and excellent adhesion to the BCB dielectric layer. The resistor films also act as a seed layer for direct electroplating
of copper traces. The NiP alloys can also be tailored to a variable temperature coefficient of resistance (TCR) with different
alloy compositions. The electroless process can be adopted in the PCB manufacturing industries with no additional investment.
This article is the first report on electroless plated thin film resistors on low loss BCB dielectric. 相似文献
The photocatalytic degradation of indigo carmine dye was studied using hydrothermally prepared TiO2 impregnated activated carbon (TiO2: AC). A comparison between the degradation of the indigo carmine dye using commercial TiO2 and TiO2: AC revealed the efficiency of the title compound. The degradation reaction was optimized with respect to the dye concentration
and catalyst amount. The reduction in the chemical oxygen demand (COD) revealed the mineralization of dye along with colour
removal. The active compound like TiO2 was impregnated onto the activated carbon surface under mild hydrothermal conditions (<250°C, P ∼ 40 bars). The impregnated
activated carbon samples were characterized using powder X-ray diffraction (XRD) and scanning electron microscope (SEM). 相似文献
Thermoluminescence (TL) characteristics of NaYF4 crystals doped with Sm3+ have been studied after γ-ray irradiation. Dependence of luminescence efficiency on Sm3+ concentration and radiation dose has been measured and possible applications of NaYF4: Sm3+ as a novel phosphor for TL dosimetry have been investigated. The efficiency of 0·3 mole% Sm3+ doped NaYF4 crystal has been found to be maximum and comparable with commercial thermoluminescence dosimetric (TLD) materials. 相似文献
Urine proteomics has become a subject of interest, since it has led to a number of breakthroughs in disease diagnostics. Urine contains information not only from the kidney and the urinary tract but also from other organs, thus urinary proteome analysis allows for identification of biomarkers for both urogenital and systemic diseases. The following review gives a brief overview of the analytical techniques that have been in practice for urinary proteomics. MALDI-MS technique and its current application status in this area of clinical research have been discussed. The review comments on the challenges facing the conventional MALDI-MS technique and the upgradation of this technique with the introduction of nanotechnology. This review projects nano-based techniques such as nano-MALDI-MS, surface-assisted laser desorption/ionization, and nanostructure-initiator MS as the platforms that have the potential in trafficking MALDI-MS from the lab to the bedside. 相似文献
An understanding of human factors and ergonomics facilitates the design of artefacts, tasks and environments that fulfil their users’ physical and cognitive requirements. Research in these fields furthers the goal of efficiently accommodating the desired percentage of user populations through enhanced awareness and modelling of human variability. Design for sustainability (DfS) allows for these concepts to be leveraged in the broader context of designing to minimise negative impacts on the environment. This paper focuses on anthropometry and proposes three ways in which its consideration is relevant to DfS: reducing raw material consumption, increasing usage lifetimes and ethical human resource considerations. This is demonstrated through the application of anthropometry synthesis, virtual fitting, and sizing and adjustability allocation methods in the design of an industrial workstation seat for use in five distinct global populations. This work highlights the importance of and opportunities for using ergonomic design principles in DfS efforts. Practitioner Summary: This research demonstrates the relevance of some anthropometry-based ergonomics concepts to the field of design for sustainability. A global design case study leverages human variability considerations in furthering three sustainable design goals: reducing raw material consumption, increasing usage lifetimes and incorporating ethical human resource considerations in design. 相似文献
The evaluated spectroscopic data are presented for 11 known nuclides of mass 211 (Hg, Tl, Pb, Bi, Po, At, Rn, Fr, Ra, Ac, Th). The 211Pa nuclide is included here but its identification remains uncertain. For 211Hg, 211Tl, 211Ac and 211Th nuclei, only the ground–state information is available. Their decay characteristics are mostly unknown. 211Fr is suggested to decay partially through ε decay mode, but its decay scheme remains poorly known. While high–spin excitations, including several isomers, are well studied in 211Pb, 211Bi, 211Po, 211At, 211Rn and 211Fr, the particle–transfer data are available for only 211Po and 211Bi.This evaluation was carried out as part of joint IAEA–ICTP workshop for Nuclear Structure and Decay Data, organized and hosted by the IAEA, Vienna and ICTP, Trieste, August 6–17, 2012. This work supersedes previous A=211 evaluation (2004Br45) published by E. Browne which covered literature before January 2003. 相似文献
From an industrial perspective there are a number of important properties of lactococci that are either carried on, or are controlled and regulated by, the cell surface e.g. phage adsorption, exopolysaccharide production, cell aggregation/sedimentation, cell autolysis and the translocation of foreign DNA. Lactococcus lactis subsp. cremoris strain E8 and its spontaneous phage-resistant variant strain 398 were used as a model system to study the molecular architecture of the lactococcal cell surface and to identify the cell wall components that are involved in phage adsorption. Genetically, the two strains were found to be very closely related as determined by the comparison of chromosomal DNA and plasmid profiles.
Two major cell wall components of both strains were the accessory polysaccharides and peptidoglycan, the latter containing, Asp, Glu, Lys and Ala in molar ratio of 1:1:1:2, respectively. There were, however, significant quantitative differences in the levels of monosaccharide in accessory polysaccharide of the two strains; the parent strain contained 15-fold more galactose and 3-fold more glucosamine.
In order to identify the components of the cell wall involved in phage adsorption, the cell walls from the parent strain (strain E8) were subjected to various chemical and enzymatical treatments before testing their ability to adsorb different phages. The result indicated that the essential component of the phage receptor in the cell wall of Lc. lactis subsp. cremoris strain E8 was carbohydrate in nature and was covalently linked to the peptidoglycans. Lectin binding experiments revealed that galactose and glucosamine were required for the adsorption of phages. An electron microscopic study of the interaction between the phages and their host showed that phages adsorb to a limited number of receptor sites which were distributed over the entire cell envelope. 相似文献
The irrigation in regions of brackish groundwater in many parts of the world results in the rise of the water-table very close to the groundsurface. The salinity of the productive soils is therefore increased. A proper layout of the ditch-drainage system and the prediction of the spatio-temporal variation of the water table under such conditions are of crucial importance in order to control the undesirable growth of the water-table. In this paper, an approximate solution of the nonlinear Boussinesq equation has been derived to describe the water-table variations in a ditch-drainage system with a random initial condition and transient recharge. The applications of the solution is discussed with the help of a synthetic example.Notations
a
lower value of the random variable representing the initial water-table height at the groundwater divide
-
a+b
upper value of the random variable representing the initial water-table height at the groundwater divide
-
h
variable water-table height measured from the base of the aquifer
-
K
hydraulic conductivity
-
L
half width between ditches
-
m0
initial water-table height at the groundwater divide
-
N(t)
rate of transient recharge at time t
-
N0
initial rate of transient recharge
-
PN0/K
-
S
Specific yield
-
t
time of observation
-
t0
logarithmic decrement of the recharge function
-
TKt/SL
-
x
distance measured from the ditch boundary
-
Xx/L
-
Yh/L
- Y
mean of Y
- Y
Variance of Y相似文献