thermal oxidative and hydrolytic stability of polyurethanes

... Understanding and probing protein stability at high temperatures and extreme conditions is relevant for a variety of biochemical and biotechnological applications Intriguingly, the stability of a ... GdnHCl-induced midpoints were 1.7 and 1.6 M GdnHCl after h of incubation and 1.1 and 1.0 M GdnHCl after 24 h of incubation for 80 and 10 lM FdTt, respectively Thermally induced FdTt unfolding ... (pH 2.5), 91 °C (pH 4), 114 °C (pH 7), and 90 °C (pH 10.5) (Fig 5) Thus, optimum stability of FdTt to heat also occurs around neutral pH, and the thermal stability is, like the resistance to chemical...

Ngày tải lên: 16/03/2014, 23:20

... (2005) Effects of submersion and aerial exposure on clutches and hatchlings of Pomacea canaliculata (Gastropoda: Ampullariidae) Am Malacol Bull 20, 55–63 Structure and pH stability of snail egg ... to be unpalatable [29], and in fact have a small number of predators The pH stability of ovorubin is within the pH range of vertebrate digestive tract fluids [30,31], and the present results indicate ... 4523 Structure and pH stability of snail egg ovorubin M S Dreon et al B A Y X X X Z Y C D log I (Q) 10 0.1 0.1 0.2 Q (Å–1) Fig Three-dimensional model of ovorubin from the eggs of P canaliculata,...

Ngày tải lên: 07/03/2014, 06:20

... the stability and kinetic constants of VsEndA and VcEndA, and found the effects to be striking, especially for VsEndA Thermal stability At 175 mm NaCl, the native enzymes display a difference of ... the effects of reciprocal mutations of two non-conserved DNA binding site residues (VsEndA, Q69N and K71N; VcEndA, N69Q and N71K) on the kinetics, thermostability and salt dependence of these enzymes ... charge and steric effects may alter substrate binding and salt sensitivity In this study, the effect of NaCl concentration on the kinetic constants and thermodynamic stability of VsEndA and VcEndA...

Ngày tải lên: 16/03/2014, 06:20

... analysis of metabolites Reactions were initiated by the addition of 100 ll of a solution of enzyme (200 lgÆmL)1) to 0.9 mL of a solution of 50 lg of substrate in 10% (v/v) dimethyl sulfoxide and incubated ... 0.1 mL of EC or CY to 1.0 mL of VM containing 10 lg of GOU For HP and M, reactions were initiated by addition of 0.1 g of HP or M to 1.0 mL of VM containing 10 lg of GOU After incubation for 12 ... reduced and polymerized form of GOU (DHP-GOU) was synthesized as follows Acetone (50 mL) containing 0.2% GOU aO and 0.2% conyferyl alcohol, and 20 mL of 3% H2O2 were dropped into 430 mL of 100...

Ngày tải lên: 17/03/2014, 03:20

... Structure and stability of bovine stomach lysozyme Y Nonaka et al Table Comparison of structural parameters among lysozymes BSL2 No of residues No of charged residues Negative Positive No of salt ... Kawano K & Nitta K (2001) Construction of an expression system of insect lysozyme lacking thermal stability: the effect of selection of signal sequence on level of expression in the Pichia pastoris ... thermostability [12] To evaluate the structural stability of BSL2, denaturant-induced unfolding and thermal unfolding were monitored Figure shows the guanidinium hydrochloride-unfolding curves of...

Ngày tải lên: 23/03/2014, 04:21

... were obtained at an interval of 0.1 nm with a scanning speed of 100 nmÆmin)1, s response time and nm bandwidth Cuvettes of 0.1 and cm path length were used in the far and near UV regions, respectively ... Stereochemistry and conformational stability of DbjA Effect of temperature The effect of temperature on DbjA activity and enantioselectivity was determined by performing activity and enantioselectivity ... calculation of the pH of maximal protein stability Eur J Biochem 271, 173–185 19 Shallom D, Golan G, Shoham G & Shoham Y (2004) Effect of dimer dissociation on activity and thermostability of the...

Ngày tải lên: 28/03/2014, 22:21

... proof of apoptosis, cleaved caspase-3 was determined in cell extracts by western blot (G) Representative blot of n = experiments showing 17 and 19 kDa caspase-3 cleavage bands and the levels of ... production of reactive oxygen species (ROS) and mitochondrial dysfunction [9,10] Increased ROS production is one of the earliest events in glucose intolerance and it may be a mechanism of pancreatic ... metabolism and ATP production, and increased ROS production and UCP2 levels These alterations occurred at a physiologically relevant ethanol level of 80 mm (368 mgÆdL)1) found in the blood of clinically...

Ngày tải lên: 29/03/2014, 08:20

... residues K8 and D72 are located near the crossing region of the helices, and the Nx atom of K8 is found ˚ at a distance of 6.2 A from the nearest side-chain oxygen of D72 Taking the functionally and ... electrostatic interactions of the side-chain of D72 that contribute to the stability of cyt c6 are at least partially local, and that the adverse effects of the mutations D72K and D72N cannot be entirely ... fits, for the thermal unfolding of wild-type cyt c6, and for the mutants D72K and D72A ⁄ K8D at pH 5.0 are shown in Fig 3A as typical examples The effect of pH on thermal unfolding of wild-type...

Ngày tải lên: 30/03/2014, 20:20

... boundedness and Lagrange stability and the classical notion of boundedness and Lagrange stability for fractional order differential systems The classical notions of boundedness and Lagrange stability ... Theory, Methods and Applications of Initial Time Difference Bound-edness Criteria and Lagrange Stability in Terms of Two Measures for Nonlinear Systems Hacettepe Journal of Mathematics and Statistics ... and boundedness criteria and Lagrange stability for initial time difference, we need to introduce the following definitions of ITD boundedness and Lagrange stability and Lyapunov-like functions...

Ngày tải lên: 20/06/2014, 22:20

... the results of Theorems 3.1 and 3.2 still hold Next, we study the Lyapunov stability of the periodic solutions of 3.32 Theorem 3.5 Assume that H4 holds Then every T -periodic solution of 3.32 is ... Holder’s ¨ yn t q dt ≤ T 1/p Mn 1/q : Mn 3.30 This proves the claim, and the rest of the proof of the theorem is identical to that of Theorem 3.1 Remark 3.3 If 1.3 takes the form l ϕp x t − cx t − ... Natural Science Foundation of China 10971202 , and the Research Grant Council of Hong Kong SAR, China project no HKU7016/07P References S Lu and W Ge, “On the existence of periodic solutions for...

Ngày tải lên: 21/06/2014, 16:20

... 2 Journal of Inequalities and Applications (1.1) with λ = by making use of the Faedo-Galerkin approximation, and then considered asymptotic stability of the solution by using Nakao ... applications of differential inclusions On the other hand, it is interesting to mention the existence and nonexistence of global solutions for nonlinear wave equations with nonlinear damping and source ... of Inequalities and Applications By Mintiy’s monotonicity argument (see, e.g., [17]), in L2 0,T;W −1,p (Ω) ζ = Ay (3.37) Therefore the proof of Theorem 2.2 is completed Asymptotic behavior of...

Ngày tải lên: 22/06/2014, 18:20

... 2 Journal of Inequalities and Applications (1.1) with λ = by making use of the Faedo-Galerkin approximation, and then considered asymptotic stability of the solution by using Nakao ... applications of differential inclusions On the other hand, it is interesting to mention the existence and nonexistence of global solutions for nonlinear wave equations with nonlinear damping and source ... of Inequalities and Applications By Mintiy’s monotonicity argument (see, e.g., [17]), in L2 0,T;W −1,p (Ω) ζ = Ay (3.37) Therefore the proof of Theorem 2.2 is completed Asymptotic behavior of...

Ngày tải lên: 22/06/2014, 22:20

... studied the stability of the equilibria, existence of Hopf bifurcation, limit cycles, homoclinic loops, and even catastrophe On the other hand, in view of the periodic variation of the environment ... Rosenzweig and R MacArthur, Graphical representation and stability conditions of predator-prey interactions, Amer Natur 97 (1963), 209–223 S Ruan, Absolute stability, conditional stability and bifurcation ... asymptotic stability theorem [1], also in view of the positive definition of V and (3.9), we obtain that the trivial solution of (3.6) is globally asymptotically stable By the medium of (3.5),...

Ngày tải lên: 23/06/2014, 00:20

... a C-function of im P (t) of (3.11) Thus, C-classes R of (2.1) and RUimP of the invariant subspace im P of the solution space of (3.11) coincide Suppose that xδ (t) is a solution of the perturbed ... holds for all t ≥ t0 ≥ and any solution x( · ) of (2.1) (2.2) The Central Exponent and Asymptotic Stability The set RA,B of all C-functions of (2.1) is called C-class of (2.1) For any function ... concept of central exponent of linear DAEs similar to that of ODEs (see [2]) The paper is organized as follows In Sec we introduce the notion of the central exponent and some properties of central...

Ngày tải lên: 06/08/2014, 05:20

... particularly of production possibilities and stability of mixed beech/larch stands Material Characteristics of experimental stand Stand No 131 F17/7b originated through natural regeneration of six ... trees and one European larch Methods of field studies and evaluation of results Methods of the evaluation of growth, development, mortality and production potential of particular experimental stands ... At an age of 51 years, the stand with the proportion of beech and larch 80 and 20%, respectively, had the total growing stock of 430 m3/ha With the proportion of beech and larch 60 and 40%, respectively,...

Ngày tải lên: 07/08/2014, 03:22

... Wood extracts and colour stability Figure Absorption spectra of methanol solutions of 1.0 10−4 M DPPH and of oak extract at 0.3, 1.0, and 3.0 g L−1 527 Figure Correlation between ε280 and total ... extent of reaction of DPPH with extracts We also want to lighten the role of extractives in reactions spoiling colour of wood submitted to solar-type irradiation, and examine links between colour stability ... colour stability of a wood and antioxidant capacity of its extracts MATERIALS AND METHODS 2.1 Chemicals, industrial extracts, and wood samples Reagents were the purest grade of Fluka, Merck,...

Ngày tải lên: 07/08/2014, 16:20

... Thermal Stresses and Temperature Control of Mass Concrete Thermal Stresses and Temperature Control of Mass Concrete Zhu Bofang China Institute of Water Resources and Hydropower Research and ... Society, and a member of the standing committee of the China Civil Engineering Society and the standing committee of the China Hydropower Engineering Society He is the founder of the theory of thermal ... of thermal stress and temperature control of mass concrete, including two basic theorems of creep of nonhomogeneous concrete structures, the law of variation, and the methods of computation of...

Ngày tải lên: 21/04/2015, 13:38

... Deionized DOF Degree of freedom E0 Energy of primary electron EBL Electron-beam lithography EC Conduction band edge of Si EC,0 Conduction band edge of Si under zero bias EF Fermi level EG Band gap of ... catalysts and the generation of hydrogen (H2) bubbles From these two modes of instability, we define a vii regime of etch chemistry and catalyst spacing for which catalyst stability and vertical ... study on the mechanism and catalyst stability of metal-assisted chemical etching (MACE) of Si in HF and H2O2 using isolated Au catalyst The role of electronic holes on etching of Si underneath Au...

Ngày tải lên: 08/09/2015, 18:39

... with side lengths of 51, 76 and 102mm (Hill and Quintiere 2000) and 89mm cube of cooked and uncooked wood blocks, chips and sawdusts (Cuzzillo 1997) In addition to Semenov model and Frank-Kamenetskii ... ignition of wood are evaluated by providing for corresponding changes in thermophysical properties of wood within the framework of thermal models The value of thermal constants, heat of wetting and ... objectives, the focus of this thesis is on thermal combustion and oxygen chemisorption of preheated wood at low temperature, long-term heating The scope of work and the structure of discussion in...

Ngày tải lên: 14/09/2015, 14:14

... pyrolysis of individual components such as cellulose and lignin, the application of semi-global model to wood as a biomass is still rare The lack of full understanding of pyrolysis scheme and its ... models the formation of cracks and fissures at the char surface, since high-temperature drying occurs just incipient of or in tandem with flaming combustion The formation of cracks and fissures greatly ... description of the thermal degradation of wood considers the solid as a single homogenous species One of the widely used primary wood degradation mechanisms of such description is based on Shafizadeh and...

Ngày tải lên: 14/09/2015, 14:14