Qual a disponibilidade de um equipamento que apresenta um tempo médio entre falhas de 80 horas e um tempo de reparo de 10 horas?

Considerando as ferramentas de metal duro, afirma-se que:

I. O metal duro é composto principalmente de tugstênio e molibdênio.

II. A utilização de ferramentas de metal duro do grupo K é indicada para a usinagem de alumínio e cobre.

III. O metal duro é obtido através do processo de fundição a vácuo.

IV. Em ferramentas de metal duro utiliza-se o TiC como base para o revestimento com óxido de alumínio.

Está(ão) correta(s) a(s) afirmativa(s)

Considere os seguintes compostos:

I. hidróxi-benzeno

II. etanol

III. propanona

IV. ácido etanóico

A ordem crescente correta de acidez é

Sobre Retificadores Controlados de Silício, analise as afirmações abaixo.

I. Se o valor da corrente que circula entre os terminais anodo e catodo de um SCR em condução é reduzida de forma a ser menor que o valor da corrente de manutenção I_H, o SCR passa do estado de condução para a região de bloqueio, sob condições fixas.

II. O LASCR é um SCR ativado por luz, no qual o controle da condução pode ser feito através do terminal de gatilho ou pela incidência de luz sobre o dispositivo.

III. Aplicando-se um potencial de tensão positivo no terminal do anodo em relação ao catodo e um pulso de tensão positivo com amplitude suficiente para o disparo ao terminal de gatilho, o SCR entra em condução direta.

A arquitetura OSI (Open Systems Interconnection), ou Camadas OSI foi definida para estabelecer uma forma comum de conectar computadores. Assinale a alternativa que NÃO representa uma das camadas do Modelo OSI

The giant neighbours are more rivals than partners

Feb 4th 2010

China and India: Prospects for Peace. By Jonathan Holslag. Columbia University Press

For a book about two countries whose most recent war was five decades ago, “Prospects for Peace” seems a quirky subtitle. Jonathan Holslag, a Brussels-based think-tanker, argues that, since China’s swift and bloody humiliation of India in 1962, the neighbours have “tottered at least five times on the verge of war”. But the last time troops massed on the border was in 1986. Bilateral trade has boomed, and hundreds of thousands of Indians and Chinese now visit the other country each year, including a succession of senior politicians toasting a beautiful friendship.

As Mr. Holslag explains, however, the relationship is still marked as much by unremitting strategic mistrust as by burgeoning co-operation. His contribution to a recent flurry of India-China books attempts to reconcile these contradictory trends. His conclusions are rather unsettling.

Most of the other books on the area concentrate inevitably on the implications of the two countries’ economic rise. The simultaneous emergence into the global economy of two countries containing nearly two-fifths of the world’s people is after all an unprecedented phenomenon. Moreover, China’s dominance of global manufacturing seems matched by India’s arrival as an important provider of information-technology and other services. Mr. Holslag quotes Zhu Rongji, a former Chinese prime minister: “You are number one in software. We are number one in hardware…Together we are the world’s number one.” That is India’s misfortune. Hundreds of thousands of Indians work in IT* services whereas manufacturing for export provides China with tens of millions of jobs. Mr. Holslag predicts that India will challenge China’s role as the world’s manufacturer, but that seems far-fetched.

This complementarity has been accompanied by a number of alliances of convenience, most notably in resisting pressure from the rich world to agree to fixed targets for limiting carbon emissions. There was even an agreement in 2006 to work together to avoid bidding up the prices of energy resources in third countries.

The limited effect of that pact, however, is one reason to believe Mr.

Holslag’s prognosis of a “fiercer economic rivalry and more aggressive regional diplomacy”. Another is what Lalit Mansingh, a former Indian diplomat, calls “the ghost at the banquet”: China’s increasing diplomatic and military influence in Asia—and India’s fear of it.

As Mr. Holslag notes, the defeat in 1962 has left a deep suspicion of China in India’s political, academic and diplomatic circles, which is reflected in public opinion. India claims an area of Chinese-held territory in Kashmir the size of Switzerland, while China claims an area three times larger in what is now Indian Arunachal Pradesh. The border dispute remains unresolved. What had lazily been assumed to be the obvious solution—the status quo, in which each country keeps large swathes of territory claimed by the other—seems, if anything, further away than ever. The political difficulties of selling such a deal in India have long been obvious. But China’s renewed harping on its claim in recent years suggests that it in fact does want more than it already has.

* IT – Information Technology.

The author of this review informs us that

Os polissacarídeos, além de representarem formas de armazenamento de energia, também atuam nas células como componentes estruturais.

O principal componente estrutural da parede celular de fungos, bem como do exoesqueleto de insetos e crustáceos, é a:

Através do utilitário iptables é possível definir regras de firewall. Uma regra muito utilizada é o redirecionamento de portas para ativar o “proxy transparente”. O comando correto que realiza o redirecionamento de portas para o squid é