The coagulation of oil in water is potentially cost-effective for removing oil from water. A coagulant consisting of sawdust (79.6% by volume), bentonite (15.8% by volume), and calcium hydroxide (4.7% by volume) gives coagulation efficiency of ≥94% and coagulation time of ≤ 45 s. The resulting coagulated material (a semisolid) floats on water. Its oil (liquid) content, which decreases with a de...

The choice of studying economics instead of another subject should be motivated by the fact that economics training equips students with skills and knowledge that other disciplines do not provide. Which are these skills and knowledge, however, is not always very clear. This article clarifies such issue by first exploring the philosophical foundations and the defining features of the discipline,...

In this paper, we analyze and compare general development and individual behavior on two non-profit internet-based hospitality exchange services – bewelcome.org and warmshowers.org. We measure the effort needed to achieve a reallife interaction, whereby the advantages of mutual altruism arise. The effort needed is the communication quantified in units of time. Since the amount of effort is not ...

How important are oil price fluctuations and oil price volatility on equity market performance? What are the policy implications if volatility turns out to be significant? We assess this issue in an economics/finance nexus for Korea using a VEC model including interest rates, economic activity, real stock returns, real oil prices and oil price volatility. Results indicate the dominance of oil p...

I 1935, Albert Einstein and collaborators wrote two papers at the Institute for Advanced Study. One was on quantum mechanics [1] and the other was on black holes [2]. The paper on quantum mechanics is very famous and influential. It pointed out a feature of quantum mechanics that deeply troubled Einstein. The paper on black holes pointed out an interesting aspect of a black hole solution with n...