Tag: osmosis

Molecular Theory Application to Biology

 We have introduced a molecular model for osmosis and have shown that free molecules exist in liquids and solids.   The number of free molecules is directly related to vapor pressure and the temperature of the substance.   From the osmosis experiment we find that water moves from the pure waterside (higher vapor pressure) through the membrane ….  Read More

Osmosis flow for Vesicles and Cells

I recently learned of the 2013 Nobel Prize for physiology or medicine shared by James Rothman, Randy Schekman and Thomas Sudhof, for their work on improving the understanding of structure and function of cell vesicles.    A vesicle is a small fluid-filled membrane sac that occurs both within and outside of cells.    Problems within these vesicles ….  Read More

Successful Seed Storage

Seed Storage Factors. Many elements affect the viability of stored seeds.   Two principal factors that we can control are seed initial moisture content and temperature of storage.   We further assume that temperature and seed moisture remain constant during storage.  Storage time is defined as the years of storage when 90% of the initial batch of ….  Read More

My Tree Drips

My tree drips. We proposed a model for maple tree sap collection.     Sap rises as vapor in a tree.   When the temperature drops below freezing, the excess vapor freezes.    Then, as the temperature warms, the frozen sap thaws to a liquid which is then collected.   This liquid sap is in a non-equilibrium condition. that is ….  Read More

Pressure

Vapor Pressure II As we noted previously, the osmosis process of molecular movement through a membrane is directly related to vapor pressure difference.  This agrees with other models for fluid flow.    Flow is directly related to pressure difference and flow proceeds from a high-pressure area to a low-pressure area.   But, what is pressure?      We introduce ….  Read More

Maple Syrup

We are approaching maple syrup season.   Sap is collected from Late February to April.   Forty gallons of sap boil down to approximately 1 gallon of maple syrup.  I tapped my sixty-foot-high maple tree several years ago and again this year, then inserted a pressure gage.  I recorded pressure, ambient temperature and tree trunk temperature at ….  Read More

Vapor Pressure

Others have suggested that vapor pressure is the driving force for osmosis, they were slapped in the face also.    Osmotic pressure is approximately 140 times greater than vapor pressure. We asked the question what is vapor pressure?  Frankel (1943) suggested that liquids and solids can be represented as crystal lattice structures with molecules at the ….  Read More

Reverse Osmosis

REVERSE OSMOSIS The Osmosis experiment has intrigued many people for years.   Water flowed uphill through a membrane into wine.   Water flow stops when a high pressure (osmotic pressure) is applied to the wine.   Further increases in pressure on the wine will cause pure water to flow from the wine to the water.   This is known ….  Read More

Osmotic Pressure

OSMOTIC PRESSURE JA Nollet’s simple experiment (1748) to investigate the filter efficiency of a bladder membrane produced an enigma which is still misunderstood by many persons today.    Wine in a column was separated from pure water by a pig’s bladder membrane (figure 1).    The static pressure produced by a column of wine was expected to ….  Read More