297 research outputs found

    Localized peaking regimes for quasilinear parabolic equations

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    This paper deals with the asymptotic behavior as tβ†’T<∞t\rightarrow T<\infty of all weak (energy) solutions of a class of equations with the following model representative: \begin{equation*} (|u|^{p-1}u)_t-\Delta_p(u)+b(t,x)|u|^{\lambda-1}u=0 \quad (t,x)\in(0,T)\times\Omega,\,\Omega\in{R}^n,\,n>1, \end{equation*} with prescribed global energy function \begin{equation*} E(t):=\int_{\Omega}|u(t,x)|^{p+1}dx+ \int_0^t\int_{\Omega}|\nabla_xu(\tau,x)|^{p+1}dxd\tau \rightarrow\infty\ \text{ as }t\rightarrow T. \end{equation*} Here Ξ”p(u)=βˆ‘i=1n(βˆ£βˆ‡xu∣pβˆ’1uxi)xi\Delta_p(u)=\sum_{i=1}^n\left(|\nabla_xu|^{p-1}u_{x_i}\right)_{x_i}, p>0p>0, Ξ»>p\lambda>p, Ξ©\Omega is a bounded smooth domain, b(t,x)β‰₯0b(t,x)\geq0. Particularly, in the case \begin{equation*} E(t)\leq F_\mu(t)=\exp\left(\omega(T-t)^{-\frac1{p+\mu}}\right)\quad\forall\,t0,\,\omega>0, \end{equation*} it is proved that solution uu remains uniformly bounded as tβ†’Tt\rightarrow T in an arbitrary subdomain Ξ©0βŠ‚Ξ©:Ξ©β€Ύ0βŠ‚Ξ©\Omega_0\subset\Omega:\overline{\Omega}_0\subset\Omega and the sharp upper estimate of u(t,x)u(t,x) when tβ†’Tt\rightarrow T has been obtained depending on ΞΌ>0\mu>0 and s=dist(x,βˆ‚Ξ©)s=dist(x,\partial\Omega). In the case b(t,x)>0b(t,x)>0 βˆ€β€‰(t,x)∈(0,T)Γ—Ξ©\forall\,(t,x)\in(0,T)\times\Omega sharp sufficient conditions on degeneration of b(t,x)b(t,x) near t=Tt=T that guarantee mentioned above boundedness for arbitrary (even large) solution have been found and the sharp upper estimate of a final profile of solution when tβ†’Tt\rightarrow T has been obtained.Comment: 27 page

    On blow-up conditions for nonlinear higher order evolution inequalities

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    We obtain exact conditions for global weak solutions of the problem \left\{ \begin{aligned} & u_t - \sum_{|\alpha| = m} \partial^\alpha a_\alpha (x, t, u) \ge f (|u|) \quad \mbox{in } {\mathbb R}_+^{n+1} = {\mathbb R}^n \times (0, \infty), & u (x, 0) = u_0 (x) \ge 0, \end{aligned} \right. to be identically zero, where mm and nn are positive integers, aαa_\alpha and ff are some functions, and u0∈L1,loc(Rn)u_0 \in L_{1, loc} ({\mathbb R}^n)

    QUALITY OF LIFE IN TYPE-I DIABETES MELLITUS PATIENTS WITH DIABETIC VEGETOPATHY

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    "Quality of life" represents one of the most important parameters of individual coping the problems of social adaptation in case of persisting manifestations of the basic disease. A total of 46 type I diabetes mellitus patients with diabetic vegetopathy were examined. Diagnosis was anamnestically and instrumentally verified. Patients' quality of life was investigated using MMP1 in a Kincannon's variant, Zungs depression scale, and Spitcer's quality-of-life scale. The following code was established: schizoidia - psychasthenia - hypochondria - paranoia. According to the depression scale, there was a slight depression in 51,7 per cent of the patients, a moderate - in 36,5 per cent but a severe - in 13,7 per cent. According to the quality-of-life scale, the parameter of self-confidence was characterized as poor in 17,3 per cent of the cases, moderately good - in 31 per cent but good - in 51,7 per cent. Social adaptation was poor in 6,8 per cent of the patients, moderately good - in 31 per cent but good - in 62,2 per cent. The correlation between the expression of vegetopathy, the severity of diabetes mellitus, the self-confidence, social adaptation and "social inertia" was discussed
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