If you are soon to empty, clean and inspect effluent pits, sumps, storage tankers or tanker-out lagoon effluent-be careful. The partial microbial breakdown of wastes during anaerobic (without oxygen) storage produces toxic gases such as ammonia, carbon dioxide and hydrogen sulphide.

These gases mostly remain dissolved while the effluent is undisturbed but are rapidly released during any pumping, agitation or mixing. The hazards are increased in pit-ends, tanks and tankers because carbon dioxide and hydrogen sulphide, being heavier than air, can concentrate to very high levels with possibly fatal results.

Hydrogen sulphide (H2S) is potentially the most lethal of the manure gases. It is colorless, has a characteristic 'rotten-egg' smell (when dilute) and is slightly heavier than air. At high concentration it is a rapid and powerful systemic poison and is instantly lethal. Above 1,000 ppm our sense of smell is paralysed so its warning odour is not detected.

A CAT scan (computer assisted tomography or computed axial  tomography or computed tomography, CT) is a three-dimensional (3D)  image reconstructed from a series of two-dimensional X-ray images.  Compared with a conventional X-ray image, a CAT scan provides better  resolution, which helps identify the position, size and shape of  tumors, among other medical applications.

Cormack won the Nobel Prize in medicine in 1979 for discovering the mathematical formulas that allow scientists to  reconstruct an object's cross section from a series of two-dimensional  X-ray images. (Co-winner Godfrey Hounsfield constructed the first CAT  scan system used in medical care.)

Other imaging methods, such as magnetic resonance imaging ,  frequently are used in medicine today, but computed tomography is still  popular among scientists. Structural biologists use cryo-electron  tomography to reconstruct 3D images of proteins from multiple 2D images  taken using an electron microscope. This technique is similar to a CAT  scan, except the specimen is frozen and repeatedly tilted to acquire  images from different angles (in a medical CAT scan, the patient lies  still, at room temperature, while the X-ray source rotates around the  patient).

Researchers also use a variation of the CAT scan to examine fossils.  High-resolution X-ray CT can resolve much finer details than medical  CAT scans, probably because radiation exposure is not an issue with  animal remains.

My favorite use of CT scanning? Rather than disassembling a vintage  guitar to see how it was built, scientists used CT scans to determine  how the instrument's bracing was assembled . The Gretsch model 6120 was manufactured with unique bracing from 1959-1961. Once the CT scan  revealed the instrument's exact measurements, guitar makers were able  to recreate the unique bracing.

Another Egyptian shadow clock or sundial, possibly the first portable timepiece, came into use around 1500 BCE. This device divided a sunlit day into 10 parts plus two "twilight hours" in the morning and evening. When the long stem with 5 variably spaced marks was oriented east and west in the morning, an elevated crossbar on the east end cast a moving shadow over the marks. At noon, the device was turned in the opposite direction to measure the afternoon "hours."

The merkhet, the oldest known astronomical tool, was an Egyptian development of around 600 BCE. A pair of merkhets was used to establish a north-south line (or meridian) by aligning them with the Pole Star. They could then be used to mark off nighttime hours by determining when certain other stars crossed the meridian.

In the quest for better year-round accuracy, sundials evolved from flat horizontal or vertical plates to more elaborate forms. One version was the hemispherical dial, a bowl-shaped depression cut into a block of stone, carrying a central vertical gnomon (pointer) and scribed with sets of hour lines for different seasons. The hemicycle, said to have been invented about 300 BCE, removed the useless half of the hemisphere to give an appearance of a half-bowl cut into the edge of a squared block. By 30 BCE, Vitruvius could describe 13 different sundial styles in use in Greece, Asia Minor, and Italy.

As a bubble or parcel of air rises it moves into an area of lower pressure (pressure decreases with height). As this occurs the parcel expands. This requires energy, or work, which takes heat away from the parcel. So as air rises it cools. This is called an adiabatic process.

Since cold air can hold less water vapor than warm air, some of the vapor will condense onto tiny clay and salt particles called condensation nuclei. The reverse is also true. As a parcel of air sinks it encounters increasing pressure so it is squeezed inward.

This adds heat to the parcel so it warms as it sinks. Warm air can hold more water vapor than cold air, so clouds tend to evaporate as air sinks.

Kangaroos are herbivorous, eating a range of plants and, in some cases, fungi. Most are nocturnal but some are active in the early morning and late afternoon. Different kangaroo species live in a variety of habitats. Potoroids, for example, make nests while tree-kangaroos live above ground in trees. Larger species of kangaroo tend to shelter under trees or in caves and rock clefts.

Kangaroos of all sizes have one thing in common: powerful back legs with long feet. Most kangaroos live on the ground and are distinguished from other animals by the way they hop on their strong back legs. A kangaroo’s tail is used to balance while hopping and as a fifth limb when moving slowly.

All female kangaroos have front-opening pouches that contain four teats. This is where the ‘joey’, or young kangaroo, is raised until it can survive outside the pouch.

Most kangaroos have no set breeding cycle and are able to breed all year round. Because they are such prolific breeders, a kangaroo population can increase fourfold in five years if it has continuous access to plentiful food and water.

The event took take place about one mile from shore just north of the pier at Deerfield Beach, Fla. It was 20 days short of one year ago that, while conducting an in depth search of the vessel CBP officers discovered a void space behind one of the unoccupied crew quarters wood paneling.

Upon removing the paneling a metal box was found welded to the bulk head. Inside the metal box were 154 kilo-sized bricks, which field tested positive for cocaine. The cocaine had an estimated street value of $12 million.

A collaboration of federal, state, and local agencies working alongside private stakeholders were able to successfully navigate the complex set of legal rules and regulations required to complete this project. It was a daunting task that covered everything from deciding on a location and properly preparing the vessel to insuring that all environmental and historical concerns were addressed.

The vessel was renamed “The Miracle of Life” and now sits in about 140 feet of water awaiting the many recreational divers who will visit her in the years to come.

“This event was the result of an outstanding interception and seizure by CBP. It also demonstrates what we are capable of accomplishing when we work together with our partners towards a common goal,” said Director of Field Operations Harold Woodward.

The earliest evidence for specifics of martial arts as practiced in the past comes from depictions of fights, both in figurative art and in early literature, besides analysis of archaeological evidence, especially of weaponry.

Wrestling is a human universal, and is also observed in other great apes, especially in juveniles. The spear has been in use since the Lower Paleolithic and retained its central importance well into the 2nd millennium AD. The bow appears in the Upper Paleolithic and is likewise only gradually replaced by the crossbow, and eventually firearms, in the Common Era. True bladed weapons appear in the Neolithic with the stone axe, and diversify in shape in the course of the Bronze Age.

One very early example is the depiction of wrestling techniques in a tomb of the Middle Kingdom of Egypt at Beni Hasan (ca. 2000 BC). An even earlier depiction of Bronze Age military equipment is depicted on the "war panel" of the Standard of Ur (ca. 2600 BC), which does however not show actual combat.

Literary descriptions of combat begin in the 2nd millennium BC, with cursory mention of weaponry and combat in texts like the Gilgamesh epic or the Rigveda. Detailed description of Late Bronze Age to Early Iron Age hand-to-hand combat with spear, sword and shield are found in the Iliad (ca. 8th century BC). Pictorial representations of fist fighting in Minoan civilization date to the 2nd millennium BC.