domingo, 5 de junio de 2016

Densidad electrónica en Ingeniería Quimifica.


Los estados de transición de transposición de hidruro obtenidos mediante ab initio y DFT, se ha encontrado que lo que determina la posición y el enlazamiento del átomo de hidrogeno es el momento dipolar eléctrico, ya que debido al efecto deslocalizante del carbocatión ocurre un desplazamiento de electrones modificando el momento dipolar para cada estado de transición. Un buen ejemplo es la transposición de hidruro del ion carbenio (2)-heptilo a ion carbenio (3)-heptilo representado en la siguiente figura.


La densidad electrónica de las estructuras presentes en el paso elemental de la transposición de hidruro del ion carbenio (2)-heptilo al ion carbenio (3)-heptilo concuerda con la dirección del momento dipolar eléctrico del ion carbenio, ya que el momento dipolar esta en dirección de lado más deficiente de electrones (zona roja), por consecuencia el hidruro que se transpone (en asterisco) se enlazara del lado del carbono 3C más electronegativo (zona azul) como se muestra en la siguiente figura.
       
Esto demuestra que la geometría depende tanto de los momentos dipolares de enlace (Densidad electrónica), como de la polaridad del ion carbenio. Esto puede ayudar a calcular los estados de transición de parafinas de cadena larga de una manera más rápida con el objetivo de establecer modelos cinéticos para el desarrollo de procesos de refinación o para optimizar el diseño del reactor y los parámetros de operación, así como también para tener mejores predicciones de operación.

lunes, 23 de mayo de 2016

Reestructuración de los contenidos de la página web. Disculpe las molestias



                         En Construcción

                  En Construcción   Estamos TrabajandoEn Construcción

lunes, 16 de mayo de 2016

Facebook at 10 – 2014 archive Tech Weekly podcast

his episode originally aired on February 5 2014. We are currently working on a new digital culture and technology podcast that will launch in June. If you have a story about how tech has influenced or impacted your life, email us at podcasts@theguardian.com.
On this episode of Tech Weekly, Aleks Krotoski looks back over Facebook’s first 10 years. Aleks is joined by John Naughton, professor of public understanding of technology at the Open University and author of From Gutenberg to Zuckerberg: What You Really Need to Know About the Internet. John discusses his fear that Facebook is in danger of swallowing the web.


Also Aleks is joined by members of the Guardian tech team, Charles Arthur, Jemima Kiss, Samuel Gibbs and Alex Hern to explore the digital ecology that gave rise to Mark Zuckerberg’s platform, the hard numbers behind it’s success, the first 10 users on the network and why some of us choose to escape Facebook’s clutches.

How can I provide guests with Wi-Fi without giving them my password?

I intend to register on AirBnB and I’d like to know how to share my fibre optic internet connection safely, without giving out the main Wi-Fi password. I believe some routers have guest access features, but not the one I use: a BT Home Hub 3. I am also thinking about OpenDNS as an additional option to screen out pornography etc. I am open to buying another router if necessary. Noel
This is a topic that should interest people renting out their homes and small businesses that want to offer clients free Wi-Fi access – I wish my dentist did, for example.
You’re right in thinking that the simplest solution is a router that offers guest access as a built-in feature. This applies to many AsusTP-LinkNetgear andLinksys modems, among others (these links are meant to provide examples, not recommendations, but they all rank pretty well on Amazon.co.uk).
When BT launched Infinity, it provided separate VDSL2 modems to make the connection to the OpenReach cabinet on the street. If you have a BT Home Hub 3, I assume you have one of these. (The BT Home Hub 5 has both VDSL2 and ADSL2 routers built in.) If so, in theory, you should be able to plug a different router into the VDSL2 modem – but perhaps readers could comment if they have tried this and failed. If not, go for a VDSL2/ADSL2 combo.

Setting it up

To set up the guest network, log on to the new router and select Guest Network (or something similar) from the admin page. You can then enable the setting for either the 2.4GHz or the 5GHz network or both, and type in whichever network name – ie SSID – you want. In some cases, you won’t have a choice: the router may simply add -guest to your current SSID.
You must also choose an authentication system, such as WPA2-Personal and an access key. In general, it’s not secure to run a guest network that isn’t encrypted, and especially not one with a default password, such as Linksys’s BeMyGuest.

Doom was video gaming's punk momen


his was how it happened for me, and I guess for a lot of people at the time. In 1993 I was working part-time at a game development studio while studying English and Drama at Warwick university. The studio, Big Red Software, was five guys in a small office above a printers in Leamington Spa. We ate, drank and breathed video games. If we weren’t making them, we were playing them. One day, we got Doom working across the office computer network. It meant that we could play together, co-operatively. That was 10am in the morning. We played for 16 hours straight. When I got outside, I saw every garage door as a potential demon entry point.
Today, More than 20 years later, Id Software is releasing a new version of Doom. It is throughly updated, with high-end visuals and contemporary design sensibilities – early word is that it’s a successful modernisation. But it can never do what Doom did back then. There had been other first-person games before it – Id itself made the Wolfenstein titles. But for this game, the brilliant coder John Carmack built a new engine, capable of rendering more complex environments in 3D. Well, sort of 3D. The maps themselves were 2D, and there was no vertical camera movement. Everything happened on a fixed plane.
It didn’t matter – in fact, it’s part of the game’s brilliance. Doom is utterly stripped back and purposeful. No pixel is wasted. Although the creative director, Tom Hall, wrote an exhaustive backstory for the game – about space marines arriving at a base on the Martian moon of Phobos to find it over-run with demons – the other leading members of the team, John Carmack and John Romero, hacked it all out. The story is only ever hinted at, and all human detail is ripped from the locations. These are spaces of death and horror; they are in service only to the core experience of the game: blasting the shit out of everything else.
In January 1976, the Ramones gathered in the Plaza sound studio in New York and over the course of a week, on a budget of $6,400, they recorded an album that distilled the essence of the burgeoning punk rock movement – the anger, the energy, the aesthetics – into one perfect slab of vinyl. In this way, it changed the course of popular music. It felt dangerous and provocative.
The Ramones in August 1976
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 The Ramones in August 1976. Photograph: Michael Ochs Archives

A game for kids who felt disenfranchised and frustrated

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Similarly, Id Software tuned into1990’s teenage cultural ephemera, and scared parents and politicians in the process. Drawing influences from death metal, the Evil Dead movies, HR Gieger and Aliens, the team created an insular and furious experience. The walls are slime-splattered screaming faces, there are dismembered bodies, the demons stomp and spit and explode into guts. It was like being in a super dark music video or Dario Argento splatter flick. The tinny soundtrack, a mechanised take on metal, tapped into the rise of industrial music – and like that music, Doom was a gift to those of us who felt disenfranchised and frustrated.
The design was brilliant. These weren’t linear corridors like Call of Duty – the Doom maps were large maze-like constructions where players were forced to explore and backtrack to find colour-coded keys and progress onwards. You scurry about, collecting ammo and health, then prepare for the inevitable burst of demons whenever you enter a new room. The monsters come at you like rioters. As with the first Ramones album much of this was produced quickly, in a burst of creativity. Romero and fellow designer Sandy Peterson were pushing out new levels on a daily basis – and these levels were astonishing: great cathedrals of destruction, in which small steps and corridor twists were expertly employed to create a sense of separate areas.
Doom taught us how to shoot straight in a computer space
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 Doom taught us how to shoot straight in a computer space. Photograph: pr handout
Doom set the tone of first-person shooter weaponry. The shotgun, the chaingun, the BFG – the feel was perfect. The sound design meaty and powerful. All the information the player needed to understand what the weapons were for and when to use them was contained within their visual and audio design. Doom taught us how to shoot straight in a computer space. It also provided flexibility to the player, it allowed experimentation. Exploits like rocket jumping (yes, this was possible in Doom, by firing at a wall and running backwards) and strafe running allowed participants to game the system and shave seconds off speed runs – they made players feel creative. It was understood that, like the Ramones album, Doom was part of a new culture that embraced both creator and viewer as equal participants. When Id Software released the engine source code, fans started building and distributing their own mods, or levels, becoming part of the development process, part of the scene. Modded Doom levels were the punk zines of gaming.