May 2013 – The Book of Threes

In recent years, it seems as though more and more young students are being retained, or held back a grade, in their school. For parents who must decide whether to retain a slow learning child or send them into the next grade level, the contributing factors can be wide, varied, and difficult to sort through.

Holding a child back a grade is a choice that’s most often based on one or more of three factors: Standardized test scores, poor social skills, or serious struggles with learning “the basics.”

When these issues begin to make parents, educators, and school officials begin to consider retention, difficult decisions must be made. The choice to hold a child back a grade should not be taken lightly, as it’s a decision that will undoubtedly go on to impact the child’s education either way. When contemplating retention for your child, it’s important to remember to treat the decision carefully, and to know that some “indicators” might not be telling you to hold your child back at all, but rather to try new methods of instruction.

Go to http://www.educationnews.org/parenting/holding-them-back/ and take the test and see where your child stands.

Article by Allison Morris

In thermodynamics, the triple point of a substance is the temperature and pressure at which three phases (for example, gas, liquid, and solid) of that substance coexist in thermodynamic equilibrium. For example, the triple point of mercury occurs at a temperature of -38.8344 °C and a pressure of 0.2 mPa.

In addition to the triple point between solid, liquid, and gas, there can be triple points involving more than one solid phase, for substances with multiple polymorphs. Helium-4 is a special case that presents a triple point involving two different fluid phases (see lambda point). In general, for a system with p possible phases, there are

triple points.

The triple point of water is used to define the kelvin, the SI base unit of thermodynamic temperature.[2] The number given for the temperature of the triple point of water is an exact definition rather than a measured quantity. The triple points of several substances are used to define points in the ITS-90 international temperature scale, ranging from the triple point of hydrogen (13.8033 K) to the triple point of water (273.16 K).

Triple point cells

Triple point cells are used in the calibration of thermometers. For exacting work, triple point cells are typically filled with a highly pure chemical substance such as hydrogen, argon, mercury, or water (depending on the desired temperature). The purity of these substances can be such that only one part in a million is a contaminant, called “six nines” because it is 99.9999% pure. When it is a water-based cell, a special isotopic composition called VSMOW is used because it is very pure and produces temperatures that are more comparable from lab to lab. Triple point cells are so effective at achieving highly precise, reproducible temperatures, an international calibration standard for thermometers called ITS–90 relies upon triple point cells of hydrogen, neon, oxygen, argon, mercury, and water for delineating six of its defined temperature points.