Problem: Printed circuit board:

Other platings used are OSP (organic surface protectant), immersion silver (IAg), immersion tin, electroless nickel with immersion gold coating (ENIG), electroless nickel electroless palladium immersion gold (ENEPIG) and direct gold plating (over nickel). Edge connectors, placed along one edge of some boards, are often nickel plated then gold plated. Another coating consideration is rapid diffusion of coating metal into Tin solder. Tin forms intermetallics such as Cu5Sn6 and Ag3Cu that dissolve into the Tin liquidus or solidus(@50C), stripping surface coating or leaving voids.

Electroless silver electroless palladium immersion gold (ENEPIG) is an example of what?
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A: unanswerable

Problem: An antenna transmits and receives radio waves with a particular polarization which can be reoriented by tilting the axis of the antenna in many (but not all) cases. The physical size of an antenna is often a practical issue, particularly at lower frequencies (longer wavelengths). Highly directional antennas need to be significantly larger than the wavelength. Resonant antennas usually use a linear conductor (or element), or pair of such elements, each of which is about a quarter of the wavelength in length (an odd multiple of quarter wavelengths will also be resonant). Antennas that are required to be small compared to the wavelength sacrifice efficiency and cannot be very directional. Fortunately at higher frequencies (UHF, microwaves) trading off performance to obtain a smaller physical size is usually not required.
What size antenna would not be good when the antenna needs to be directional?
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Answer: small

Q: What is a question about this article? If the question is unanswerable, say "unanswerable".
Valencia (/vlnsi/; Spanish: [balenja]), or Valencia (Valencian: [valensia]), is the capital of the autonomous community of Valencia and the third largest city in Spain after Madrid and Barcelona, with around 800,000 inhabitants in the administrative centre. Its urban area extends beyond the administrative city limits with a population of around 1.5 million people. Valencia is Spain's third largest metropolitan area, with a population ranging from 1.7 to 2.5 million. The city has global city status. The Port of Valencia is the 5th busiest container port in Europe and the busiest container port on the Mediterranean Sea.
What is the population of Valencia's urban area?
A: 1.5 million

Context and question: During the truce of 12061208, John focused on building up his financial and military resources in preparation for another attempt to recapture Normandy. John used some of this money to pay for new alliances on Philip's eastern frontiers, where the growth in Capetian power was beginning to concern France's neighbours. By 1212 John had successfully concluded alliances with his nephew Otto IV, a contender for the crown of Holy Roman Emperor in Germany, as well as with the counts Renaud of Boulogne and Ferdinand of Flanders. The invasion plans for 1212 were postponed because of fresh English baronial unrest about service in Poitou. Philip seized the initiative in 1213, sending his elder son, Louis, to invade Flanders with the intention of next launching an invasion of England. John was forced to postpone his own invasion plans to counter this threat. He launched his new fleet to attack the French at the harbour of Damme. The attack was a success, destroying Philip's vessels and any chances of an invasion of England that year. John hoped to exploit this advantage by invading himself late in 1213, but baronial discontent again delayed his invasion plans until early 1214, in what would prove to be his final Continental campaign.
What did John do during the truce of 1206-1208?
Answer: focused on building up his financial and military resources

Question: The Boston Globe wrote that "if there's one school that can lay claim to educating the nation's top national leaders over the past three decades, it's Yale." Yale alumni were represented on the Democratic or Republican ticket in every U.S. Presidential election between 1972 and 2004. Yale-educated Presidents since the end of the Vietnam War include Gerald Ford, George H.W. Bush, Bill Clinton, and George W. Bush, and major-party nominees during this period include John Kerry (2004), Joseph Lieberman (Vice President, 2000), and Sargent Shriver (Vice President, 1972). Other Yale alumni who made serious bids for the Presidency during this period include Hillary Clinton (2008), Howard Dean (2004), Gary Hart (1984 and 1988), Paul Tsongas (1992), Pat Robertson (1988) and Jerry Brown (1976, 1980, 1992).
Is there an answer to this question: What did the Boston Globe have to say about Yale?

Answer: "if there's one school that can lay claim to educating the nation's top national leaders over the past three decades, it's Yale."

Question: Many important biochemical reactions, such as energy generation, use concentration gradients across membranes. The general lack of internal membranes in bacteria means reactions such as electron transport occur across the cell membrane between the cytoplasm and the periplasmic space. However, in many photosynthetic bacteria the plasma membrane is highly folded and fills most of the cell with layers of light-gathering membrane. These light-gathering complexes may even form lipid-enclosed structures called chlorosomes in green sulfur bacteria. Other proteins import nutrients across the cell membrane, or expel undesired molecules from the cytoplasm.
Is there an answer to this question: How does electron transit occur in bacteria?

Answer:
between the cytoplasm and the periplasmic space