Search results for "TJ"
showing 10 items of 841 documents
Modelling of the fracture toughness anisotropy in fiber reinforced concrete
2015
Steel fiber reinforced concrete is potentially very promising material with unique properties, which currently is widely used in some applications, such as floors and concrete pavements. However, lack of robust and reliable models of fiber reinforced concrete fracture limits its application as structural material. In this work a numerical model is proposed for predicting the crack growth in fiber reinforced concrete. The mixing of the steel fibers with the concrete usually creates nonuniform fibers distribution with more fibers oriented in horizontal direction, than in vertical. Simple numerical models of fiber reinforced concrete require a priori knowledge of the crack growth direction in …
Stochastic Approach for Optimal Positioning of Pumps As Turbines (PATs)
2021
A generic water system consists of a series of works that allow the collection, conveyance, storage and finally the distribution of water in quantities and qualities such as to satisfy the needs of end users. In places characterized by high altitude differences between the intake works and inhabited centres, the potential energy of the water is very high. This energy is attributable to high pressures, which could compromise the functionality of the pipelines
Solving a continuous periodic review inventory-location allocation problem in vendor-buyer supply chain under uncertainty
2019
In this work, a mixed-integer binary non-linear two-echelon inventory problem is formulated for a vendor-buyer supply chain network in which lead times are constant and the demands of buyers follow a normal distribution. In this formulation, the problem is a combination of an (r, Q) and periodic review policies based on which an order of size Q is placed by a buyer in each fixed period once his/her on hand inventory reaches the reorder point r in that period. The constraints are the vendors’ warehouse spaces, production restrictions, and total budget. The aim is to find the optimal order quantities of the buyers placed for each vendor in each period alongside the optimal placement of the ve…
Rilievo in tempo reale di difetti superficiali su corpi in movimento a velocità elevata con ultrasuoni senza contatto
2012
Il rilievo di difetti superficiali durante le ispezioni periodiche è importante poiché in genere le sollecitazioni sono maggiori in superficie e possono accelerare la crescita delle discontinuità. I difetti superficiali possono essere rilevati utilizzando alcuni metodi tradizionali di controllo non distruttivo, quali correnti indotte, liquidi penetranti, polveri magnetiche ed ultrasuoni. Alcuni tra questi metodi possono essere usati solo in condizioni statiche; gli altri presentano delle limitazioni per l’ispezione dinamica. I progressi recenti nel campo dei sensori ultrasonori senza contatto ci hanno permesso di sviluppare un sistema semplice per l’ispezione in tempo reale di corpi in movi…
Simulazione della propagazione di difetti a fatica mediante il modello di zona coesiva
2009
Le giunzioni incollate guadagnano sempre più mercato, nel campo delle costruzioni in genere, dove è necessario un alleggerimento delle strutture. Nel caso di geometrie di giunto semplici il dimensionamento avviene attraverso relazioni analitiche che restituiscono il valore massimo delle tensioni, il quale deve essere inferiore al limite di utilizzo dell’adesivo stesso. Quando le geometrie sono complesse l’approccio analitico diventa impraticabile, di conseguenza si provvede a verificare la correttezza della soluzione mediante analisi agli elementi finiti (EF). L’introduzione del modello di zona coesiva nell'analisi EF permette di simulare il danneggiamento ed il cedimento del giunto in cond…
Percepción del cambio climático en alumnado de 4º del Grado en Educación Primaria (Universidad de Valencia, España) a partir de la información de los…
2021
El cambio climático, sus causas y efectos suponen uno de los principales desafíos del siglo XXI. La enseñanza sobre este fenómeno constituye un reto para la formación de los/as futuros/as maestros/as de Primaria debido a la responsabilidad docente sobre la comprensión y posible adaptación a este fenómeno global. Los objetivos de este trabajo son: 1) Explorar y conocer los principales medios desde donde los/as futuros/as maestros/as de Primaria reciben información sobre el cambio climático; y 2) Reconocer las causas y consecuencias que se aluden en estos medios (según la percepción de los/as estudiantes) para identificar la concepción que se tiene sobre este fenómeno. A modo de estudio de ca…
Pensamiento dominante, educación y medios de comunicación
2018
Comunicar es algo más que transmitir información. El desarrollo de la tecnología e internet han evolucionado el acto de comunicar en el mundo y se han creado nuevos espacios de comunicación. Los medios de comunicación suelen estar al servicio de un determinado poder, que puede ser público o privado. Sin embargo en este artículo se pone el acento en los intereses que tienen determinados poderes del ámbito privado y el uso que hacen de los medios de comunicación para defender y promover dichos intereses. No obstante, ese poder también puede dar lugar a formas de resistencias que sirvan para subvertir el orden establecido. Los medios de comunicación sirven como altavoces del pensamiento único …
The Mediterranean Coast of Andalusia (Spain): Medium-Term Evolution and Impacts of Coastal Structures
2019
This paper shows coastal evolution along the Andalusia Region (Spain) and the impacts on it of coastal structures. The study area was divided into 47 units to calculate the erosion/accretion/stability (or evolution) rates by using the DSAS extension of ArcGIS software. Evolution rates were divided into different classes from &ldquo
Atšķirīgu atvēsināšanas metožu ietekme uz nodarbināto muskuļu asins apgādi un pēcslodzes atjaunošanos
2018
Atjaunošanās, kā amatieru, tā arī profesionālā līmeņa sportā, ir būtisks faktors, kuram ir neatsverama nozīme optimāla treniņu režīma sastādīšanā, progresa nodrošināšanā un konkurētspējīgu rezultātu sasniegšanā. Lai paātrinātu atjaunošanās procesus, plaši tiek pielietotas atvēsināšanas metodes uzreiz pēc slodzes, taču trūkst informācijas par to, vai lokāli mērķētai atvēsināšanai uz nodarbinātajiem muskuļiem ir pozitīvs efekts. Kā arī trūkst pētījumu par to, vai šajā ziņā efektīva ir arī tāda metode kā mentolu saturošu preparātu lokāla pielietošana. Darba mērķis. Noskaidrot, vai ledus-ūdens, vai mentola maisījuma aplicēšana lokāli uz nodarbinātajiem muskuļiem pēc slodzes spēj paātrināt atjau…
Pieejas “Windows kā pakalpojums” izmantošana atjauninājumu instalēšanas automatizācijai organizācijas Windows operētājsistēmās
2020
Katru mēnesi tiek veikti operētājsistēmu uzlabojumi un izlaisti atjauninājumi. Tāpēc ir ļoti svarīgi nodrošināt, lai tehniskās ierīces būtu atjaunotas un tās saņemtu jaunākos drošības un funkcionalitātes labojumus, kas mazinātu operētājsistēmas darbības traucējumu rašanās risku. Darba mērķis ir veikt atjauninājumu instalēšanas automatizāciju organizācijas Windows operētājsistēmās izmantojot pieeju “Windows kā pakalpojums”. Darbā tika veikts vispārīgs pieejas “Windows kā pakalpojums” metožu apraksts un pielietotas pieejas metodes atjauninājumu automatizācijai, tādas kā Windows Server Update Services (WSUS) un Microsoft Endpoint Configuration Manager (MECM). Darba rezultātā ir veikta Windows …