One of the basic truths regarding energy conversion is that no thermodynamic cycle can be devised that is more efficient than a Carnot cycle operating between the same temperature limits. The efficiency of the Stirling cycle (patented by Rev. Robert Stirling in 1816) can approach that of the Carnot cycle and yet has not had the commercial success…

How do siphons work? Some see atmospheric pressure, explicitly or implicitly, as a crucial factor in siphon action. Others explain that a siphon works due to a difference of water weights in unequal arms. According to the latter view, siphon action is analogous to the action of a pulley or to the behaviour of a chain that is moving over a tube. In…

Let us now praise famous physicists, and the apparatus named after them, with apologies to the writer of Ecclesiastes. I once compiled a list of about 300 pieces of apparatus known to us as X's Apparatus. Some of the values of X are familiar, like Wheatstone and Kelvin and Faraday, but have you heard of Pickering or Rhumkorff or Barlow? In an…

The enzymatic resolution of "rac"-1-phenylethanol using ethyl myristate as acylating agent and solvent and "Candida antarctica" lipase B (CAL-B) as biocatalyst was demonstrated with catalyst and medium reuse. Both enantiomers of 1-phenylethanol were isolated by sequential enzymatic reactions and product distillations. From the first enzymatic…

In sports such as baseball, softball, golf, and tennis, a common objective is to hit the ball as fast or as far as possible. Another common objective is to hit the ball so that it spins as fast as possible, since the trajectory of the ball through the air is strongly affected by ball spin. In an attempt to enhance both the coefficient of…

A demonstration was created to display the unique behavior of a familiar element, phosphorus, and to make chemistry more accessible to the introductory student. The common allotropes of phosphorus and their reactivity are discussed. In this demonstration, the white allotrope of phosphorus is synthesized from the red phosphorus obtained from a…

In this article we propose a simple and low-cost experimental set-up through which science educators can demonstrate the Seebeck effect using a thermocouple and an instrumentation amplifier. The experiment can be set up and conducted during a 1-hour laboratory session. (Contains 3 tables and 3 figures.)

The hydromonochord is a horizontal vibrating string that just makes contact with the surface of a water bath. The motion of the string sets up a pattern of swirls on the surface of the water, thus complementing the usual pattern of nodes and antinodes. The device is based on the traditional monochord. A water basin (Fig. 1) has two slits in the…

In the "The Science Study Series" book "The Physics of Television", it is stated that persistence of vision lasts for about a tenth of a second. This will be a notional figure just as 25 cm is taken to be the least distance of distinct vision. Estimates range from 1/8 to 1/16 s.

Great scientists in the past have experimented with coils and magnets. Here we have a variation where coupling occurs between two coils and the oscillatory motion of two magnets to give somewhat surprising results. (Contains 6 figures and 1 footnote.)

In this work, an inexpensive 10-gallon glass aquarium was used to study wave motion in water. The waves travel at speeds comparable to a person walking ([approximately]1 m/s). The scale of the motion allows for distances to be measured with a meterstick and for times to be measured with a stopwatch. For a wide range of water depths, standing waves…

Phosphorus (P) is the limiting nutrient controlling productivity in most inland freshwater systems. Several materials have been proposed for use to remove excess P from wastewater treatment, including volcanic lapilli and ash (tephra). There is limited data in using tephra as a P filter. There were two objectives of this study: (1) to determine…

In 1964 John Bell proved a theorem allowing the experimental test of whether what Einstein derided as "spooky actions at a distance" actually exist. We will see that they "do". Bell's theorem can be displayed with a simple, nonmathematical thought experiment suitable for a physics course at "any" level. And a simple, semi-classical derivation of…

Compost bins are beginning to make their way into home gardens and classrooms, allowing students to actively participate in greening their environment. However, do they really understand the process of composting? According to the "National Science Education Standards" (National Research Council [NRC] 1996, 20), "Learning science is something…

This study describes an approach for blind students thought health physics about how they could set a hypothesis and test it. The participant of the study used some health materials designed for high school blind student and tested her hypothesis with the data she gathered with those materials. It was asked that she should hypothesize which could…