THE PANAMA CANAL REVIEW December 5, 1952 Study Resumed on Plans for Converting Electrical System to 60-Cycle Current
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Planetary Surfaces
Chapter 4 PLANETARY SURFACES 4.1 The Absence of Bedrock A striking and obvious observation is that at full Moon, the lunar surface is bright from limb to limb, with only limited darkening toward the edges. Since this effect is not consistent with the intensity of light reflected from a smooth sphere, pre-Apollo observers concluded that the upper surface was porous on a centimeter scale and had the properties of dust. The thickness of the dust layer was a critical question for landing on the surface. The general view was that a layer a few meters thick of rubble and dust from the meteorite bombardment covered the surface. Alternative views called for kilometer thicknesses of fine dust, filling the maria. The unmanned missions, notably Surveyor, resolved questions about the nature and bearing strength of the surface. However, a somewhat surprising feature of the lunar surface was the completeness of the mantle or blanket of debris. Bedrock exposures are extremely rare, the occurrence in the wall of Hadley Rille (Fig. 6.6) being the only one which was observed closely during the Apollo missions. Fragments of rock excavated during meteorite impact are, of course, common, and provided both samples and evidence of co,mpetent rock layers at shallow levels in the mare basins. Freshly exposed surface material (e.g., bright rays from craters such as Tycho) darken with time due mainly to the production of glass during micro- meteorite impacts. Since some magnetic anomalies correlate with unusually bright regions, the solar wind bombardment (which is strongly deflected by the magnetic anomalies) may also be responsible for darkening the surface [I]. -
Rocio Del Mar, Sea of Cortez, Mexico + Other Articles Undercurrent, March
The Private, Exclusive Guide for Serious Divers March 2010 Vol. 25, No. 3 Rocio del Mar, Sea of Cortez, Mexico good liveaboard and fish life, with well-trained crew -- and sea lions IN THIS ISSUE: Dear Fellow Diver: Rocio del Mar, Mexico........ 1 I’m in the middle of the Sea of Cortez, surrounded by Two Dive Gear Recalls ..... 3 scores of darting sea lions. Their underwater barks seem as loud as if I heard them on land. So I came with a surprise, a Bonaire, Orlando, Mexico ... .4 double-horn Dive Alert that I blew underwater. And guess what? I stopped them in their tracks. Every sea lion stopped barking, Do Drugs Increase Your spun around and looked at me. If sea lions can look amazed, Risk of Bends? ............ 5 these did. I motioned to one curious guy by waving my hand toward me. “Come on over.” He moved a little closer every time Four Factors That Reduce I beckoned so I kept it up. When he got right up next to me, I Your DCS Risk ........... 6 spun my finger and he twirled away as if we had rehearsed it. Order Your Copy of Cockroach I turned around and my fellow divers were clapping. in My Regulator ............ 7 A trip to the Sea of Cortez has its marvels, and the first of them is that a trip on this spanking new liveaboard, New Dangers of Rebreather the 110-foot Rocio del Mar, begins by deplaning in Phoenix, Diving .................... 8 Arizona. Following is a four-hour van ride to Puerto Penasco, Where’s Your Customer Service, but no matter where you go, there’s always a van ride some- Scubapro? ............... -
Project JYP-1104 SALT INTRUSION in GATUN LAKE a Major Qualifying
Project JYP-1104 SALT INTRUSION IN GATUN LAKE A Major Qualifying Project submitted to the Faculty of WORCESTER POLYTECHNIC INSTITUTE in partial fulfillment of the requirements for the Degree of Bachelor of Science By Assel Akhmetova Cristina Crespo Edwin Muñiz March 11, 2012 Jeanine D. Plummer, Major Advisor Associate Professor, Civil and Environmental Engineering 1. Gatun Lake 2. Salt Intrusion 3. Panama Canal Abstract The expansion of the Panama Canal is adding another lock lane to the canal, allowing passage of larger ships. Increases in the number of transits and the size of the locks may displace more salt from the oceans into the freshwater lake, Gatun Lake, which is a drinking water source for Panama City. This project evaluated future salinity levels in Gatun Lake. Water quality and hydrometeorological data were input into a predictive hydrodynamic software package to project salinity levels in the lake after the new lock system is completed. Modeling results showed that salinity levels are expected to remain in the freshwater range. In the event that the lake becomes brackish, the team designed a water treatment plant using electrodialysis reversal for salt removal and UV light disinfection. ii Executive Summary The Panama Canal runs from the Pacific Ocean in the southeast to the Atlantic Ocean in the northwest over a watershed area containing the freshwater lake, Gatun Lake. The canal facilitates the transit of 36 ships daily using three sets of locks, which displace large volumes of water into and out of Gatun Lake. The displacement of water has the potential to cause salt intrusion into the freshwater Gatun Lake. -