Strictly positive solutions for one-dimensional nonlinear problems involving the p-Laplacian

Let $\Omega$ be a bounded open interval, and let $p>1$ and $q\in\left(0,p-1\right)$. Let $m\in L^{p^{\prime}}\left(\Omega\right)$ and $0\leq c\in L^{\infty}\left(\Omega\right)$. We study existence of strictly positive solutions for elliptic problems of the form $-\left(\left\| u^{\prime}\right\|^{p-2}u^{\prime}\right) ^{\prime}+c\left(x\right) u^{p-1}=m\left(x\right) u^{q}$ in $\Omega$, $u=0$ on $\partial\Omega$. We mention that our results are new even in the case $c\equiv0$.Comment: To appear in Bulletin of the Australian Mathematical Societ

Applicazioni dei geopolimeri come materiali compositi coibentanti e refrattari

Geopolymers are inorganic polymeric materials based on aluminosilicates. Geopolymers belong to the class of the chemically bonded ceramics (CBCs): geopolymeric resin acts as a glue for different fillers that funzionalize the material. They are synthesised at low temperature (T<350?C), they do not include water in the structure in contrast with hydraulic cements and they can withstand up to 1200?C. For this reason geopolymers could be used for high temperature and fire proof applications in the automotive and aerospace industries, non-ferrous foundries and metallurgy, civil engineering, plastics industries, waste management.I geopolimeri sono materiali polimerici inorganici a base allumino-silicatica. Appartengono alla classe delle ceramiche consolidate per via chimica (chemically bonded ceramics, CBCs) e sono dei materiali compositi: la resina geopolimerica ? il collante per le cariche che funzionalizzano il materiale. Diversamente dai cementi idraulici, i geopolimeri non contengono acqua di idratazione e sebbene siano lavorati a basse temperature (T<350?C), con tecniche usate comunemente per la presa delle resine organiche, possono resistere fino a 1200?C, anche per lunghe esposizioni. Materiali a base geopolimerica sono pertanto utilizzati in applicazioni ad alta temperatura, come stampi per fonderia, pannelli e pareti isolanti-coibentanti, materiali a prova di fuoco per automobili e aerei, refrattari, adesivi, leganti e rivestimenti per alte temperature

Soluciones positivas para problemas elípticos sublineales y singulares

Tesis (Doctor en Matemática)--Universidad Nacional de Córdoba, Facultad de Matemática, Astronomía, Física y Computación, 2018.En esta tesis se estudiaron tres problemas relacionados a ecuaciones de reacción difusión elípticas sublineales y singulares cuando el término de reacción cambia de signo. En primer lugar se trató la existencia y no existencia de soluciones estrictamente positivas para problemas sublineales asociados a un operador elíptico lineal de segundo orden en el caso unidimensional. Además, se consideró la existencia y unicidad de soluciones no negativas en el caso multidimensional. En segundo lugar, también en una dimensión, se estudiaron problemas sublineales asociados a operadores que involucran al p-Laplaciano. Finalmente, se estudió la existencia y no existencia de soluciones positivas asociadas al p-Laplaciano cuando el término de reacción es singular. En este último caso se obtuvieron resultados cuantitativos en dimensión uno y cualitativos en dimensiones mayores.Fil: Medri, Ivan Vladimir. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía, Física y Computación; Argentina

Geopolimeri: "ceramiche" per uno sviluppo sostenibile

Geopolymers are inorganic polymeric materials developed in 70\u27s by Joseph Davidovits. Geopolymers mimic natural minerals and they are the products of a geo-synthesis, i.e. a reaction that chemically integrates minerals. Geopolymers belong to the class of the chemically bonded ceramics (CBCs): they are synthesised at low temperature from a variety of materials including recycled resources and mineral wastes, reducing the energy demands and environmental impact during their production. For this reason geopolymers could be considered environmentally friendly. Geopolymers enable product designers to envisage the use of ceramic type materials with the same facility as some plastics and organic removing heavy equipment and high temperatures from the ceramic industrial plants. Geopolymer technology allows the production of a wide range of versatile materials already finding applications in many fields of industry. These applications are to be found in the automotive and aerospace industries, non-ferrous foundries and metallurgy, civil engineering, plastics industries, waste management, restoring, art and decoration, biomaterials, etc.. Geopolymers are the natural product of green chemistry, that works for a sustainable development.I geopolimeri sono materiali polimerici inorganici sviluppati negli anni \u2770 da Joseph Davidovits. I geopolimeri mimano le rocce naturali e sono il prodotto di una geosintesi, cio? una reazione che ricostituisce chimicamente le rocce. I geopolimeri appartengono alla cosiddetta classe delle ceramiche consolidate per via chimica (chemically bonded ceramics, CBCs): sono sintetizzati a bassa temperatura da una variet? di materiali includendo scarti della produzione industriale quali ceneri volanti o scorie d\u27altoforno, riducendo cos? la richiesta energetica e l\u27impatto ambientale durante la loro produzione. Per questa ragione i geopolimeri possono essere considerati ecocompatibili, "environmentally friendly". I geopolimeri consentono l\u27utilizzo di materiali con propriet? ceramiche con le stesse modalit? di alcune materie plastiche, rimuovendo gli equipaggiamenti pesanti e le alte temperature dagli impianti ceramici industriali. La tecnologia dei geopolimeri permette la produzione di una vasta gamma di materiali versatili che trovano gi? un impiego in diversi settori industriali, quali: ingegneria civile, trattamento dei rifiuti industriali, industria dell\u27automobile ed aerospaziale, fonderie di metalli non ferrosi e metallurgia, industrie plastiche, restauro, arte e decorazione, biomateriali, ecc.. I geopolimeri sono il prodotto naturale della cosiddetta "chimica verde", che lavora per uno sviluppo sostenibile

Housing Variables and Immigration: An Exploratory and Predictive Data Analysis in New York City

The relationship between housing and immigration has become relevant in the U.S., especially in a highly populated metropolis such as New York City (NYC). Determining whether immigration status affects home ownership percentage, household rent, or housing cost percentage could help understand the quality of life of NYC residents. Graphical exploration, spatial dependence tests, and spatial autoregressive models of housing and immigration variables provide some insights about their relationships. Our exploration takes place at some geographic subareas of NYC. Our results first indicate that the housing and immigration data reports spatial dependence; values of a geographic subarea are related to values of other nearby subareas. In addition, we notice that an immigrant householder is less likely to own a home and more likely to pay a higher rent asa proportion of their income. This result is more apparent in the Bronx and Manhattan. However, being an immigrant can’t be associated with higher rent amounts since household rent depends more on other factors, such as the household income

Jenang perkasa : cerita rakyat dari Kepulauan Riau

Cerita rakyat Kepulauan Riau yang berjudul Jenang Perkasa yang telah penulis tulis ini secara garis besar menceritakan kehidupan suku sampan atau suku laut yang mendiami sepanjang pesisir Pulau Bintan. Selain itu, kisah ini juga menceritakan persaingan perebutan kekuasaan yang dipadukan dengan perebutan perempuan cantik dengan munculnya tokoh Putri Bintan. Intinya cerita ini mengandung pesan moral, yaitu kebenaran pasti mengalahkan kebatilan. Cerita Jenang Perkasa ini telah penulis daur ulang sesuai dengan imajinasi penulis dengan tidak mengubah tema dasarnya. Beberapa tokoh dan kejadian sengaja penulis tampilkan dengan harapan cerita ini lebih menarik untuk baca, dapat menampilkan karakter masyarakat Melayu Kepulauan Riau khususnya dengan harapan dapat memperkaya pesan-pesan moral. Penulis menyadari banyak kekurangan dan kelemahan dalam penceritaan ini walau penulis sudah berusaha semaksimal mungkin. Untuk itu, penulis mengharapkan kritik dan saran yang membangun. Akhir kata, penulis berharap semoga cerita Jenang Perkasa ini bermanfaat dan dapat memperkaya khazanah budaya bangsa

Strictly positive solutions for one dimensional nonlinear elliptic problems

We study the existence and nonexistence of strictly positive solutions for the elliptic problems -- in a bounded open interval, with zero boundary conditions, where -- is a strongly uniformly elliptic differential operator, --, and -- is a function that changes sign. We also characterize the set of values-- for which the problem admits a solution, and in addition an existence result for other nonlinearities is presented.http://ejde.math.txstate.edu/Volumes/2014/126/kaufmann.pdfpublishedVersionFil: Kaufmann, Uriel. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física; Argentina.Fil: Medri, Iván Vladimir. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física; Argentina.Matemática Pur