When performed with chondroitinase ABC or agents other than chymopapain Percutaneous lumbar discectomymanual or automated, is considered medically necessary for treatment of herniated lumbar discs when all of the following are met: Member is otherwise a candidate for open laminectomy; and Member has failed 6 months of conservative treatment; and Diagnostic studies show that the nuclear bulge of the disc is contained within the annulus i. Percutaneous lumbar diskectomy is considered experimental and investigational for all other indications because its effectiveness for indications other than the one listed above has not been established. Clinical studies have not established any clinically significant benefit of use of a laser over use of a scalpel for percutaneous lumbar diskectomy.
Stealth technology, small cargo hold, and a propulsion bus with high acceleration You get the idea. Pirate ships and privateers might forgo defenses if they only expect to be engaging unarmed cargo ships.
But they will regret this if they have the misfortune to encounter armed enemy convoy escort ships or are surprised by a Q-ship. One section is the propulsion bus — drive engine, reactor if any, solar wings or radiator fins, propellant tankage, and a keel structure to hold it all together.
The other is the payload section that it pushes along from world to world. There are both conceptual and economic reasons to treat them separately.
Conceptually, because a propulsion bus might push many different payloads for different missions, such as light payloads on fast orbits versus heavy payloads on slow orbits. A little noticed but important feature of deep space craft is that you cannot overload them.
They do not sink, or crash at the end of the runway, or even bottom out their suspension. They merely perform more sluggishly, with reduced acceleration and for a given propellant supply less delta v. Conceptual logic is also economic logic. The outfits that build drive buses would like to sell them to lots of different customers for a broad range of assignments.
This is not necessarily an argument for true modular construction, with drive buses hitching up to payloads on an ad hoc basis like big-rig trucks and trailers. Building things to couple and uncouple adds complexity, mass, and cost — plug connectors, docking collars, and so forth.
Moreover, drive buses intended for manned ships need to be human-rated, not just with higher safety factors but provision for supplying housekeeping power to the hab, etc.
But these things, along with differing sizes or number of propellant tanks, and so forth, can all be minor variations in a drive bus design family. The payload we are most interested in is, naturally, us. The main habitat section of a deep space ship closely resembles a space station.
It is likely that habs intended for prolonged missions will be spun, for health, efficiency, and all round convenience. The design of a spin hab is dominated by the spin structure and — unless you spin the entire ship — the coupling between the spin and nonspin sections. Habs are the one major part of a deep space ship that correspond fairly well to our concept of a hull.
For those with bank cards at the ready, buying a deep space ship might be not unlike buying a computer. If your mission needs are fairly standard, you check off options on a menu.
Those with more specialized requirements can select major components — perhaps a drive bus from one manufacturer, a main crew hab from another, along with custom payload sections, service bays, and so forth, assembled to your specifications.
In fact, both technology and probable historical development suggest that fabrication and overall assembly will be two distinct phases, carried on in different places, quite unlike either shipyard or aircraft assembly practice.
In the early days, large deep space craft will be built the way the ISS was, assembled on orbit out of modules built on Earth and launched as payloads. In time fabrication may move to the Moon, or wherever else, but final assembly at least of larger craft will continue to be done at orbital facilities.
I call them cageworks, on the assumption that a cage or cradle structure provides handy anchoring points for equipment.
For game or sim purposes, my advice would be to treat drive buses and hab sections as the primary building blocks for ships, whether these components are permanently attached to each other or simply coupled together.
Both approaches might be in use. A couple of provisos. All of the above applies mainly to deep space craft, especially with high specific impulse drives. Ships for landing on airless planets have some similar features.
Ships that use rapid aerobraking, however, are aerospace craft and broadly resemble airplanes, even if they never land or even go below orbital speed.
And I have said nothing of warcraft. Kinetics are essentially just another payload. Lasers, and other energy weapons such as coilguns, probably draw power from the drive reactor, calling for some modifications in the drive bus.
Armor protection would, but discussions here have left me doubtful of its value against either lasers or kinetics. Laser stars and other major warcraft may not be dramatically different in appearance from civil craft of similar size. Though the service module did contain the life support equipment.
He noted that a nuclear powered spacecraft would probably resemble a dumb bellthat is, two spheres connected by a stick. The hab module is the forward sphere, the nuclear drive is the rear sphere, the stick is long to provide some inverse square protection from radiation, and the propellant tanks would be on the stick, probably clustered near the nuclear drive.
One can also imagine modules designed by diverse corporations being incompatible with others on purpose.
One can also imagine a tramp freighter composed of incompatible modules, being held together with bailing wire and spit. The compatibility between modules will mostly depend on how the market develops.C(, %) C-band ==> Cバンド c contact ==> c接点 C-MACCS,Centre for Mathematical Modelling and Computer Simulation ==> 数理モデル・コンピュータシミュレーションセンター.
Zero-point energy (ZPE) is the difference between the lowest possible energy, that a quantum mechanical system may have, and the classical minimum energy of the system. Unlike in classical mechanics, quantum systems constantly fluctuate in their lowest energy state due to the Heisenberg uncertainty principle.
As well as atoms and molecules, the . An Evacuated Heat Pipe Collector ( m long, m width and m thick) has been used to evaporate the water which is inside the urbanagricultureinitiative.com Evacuated Heat Pipe Collector is made of many parallel tubes having ½ inchdiameter and m urbanagricultureinitiative.com this Solar still following factors have highly considered for the investigation: • To made simple.
A total of 16 analytical methods, spanning from classical solvent extraction over different thermo-analytic and mechanical approaches to acoustic and optical spectroscopy, have been evaluated as to their ability to determine the crosslinking state of ethylene vinyl acetate (EVA), the prevailing encapsulant for photovoltaics applications.
Heat pipes are recognised as one of the most efficient passive heat transfer technologies available. A heat pipe is a structure with very high thermal conductivity that enables the transportation of heat whilst maintaining almost uniform temperature along its heated and cooled sections. Experimental Investigation on Thermal Conductivity Mechanical Engineering Department, Nirma University Abstract: aluminum flakes with the evacuated powders. By using Heat transport or entropy production is a common problem with all low temperature work. Sometimes heat A quick coupling (size 25mm) is used for the connection. Bioplastic is a biodegradable material that originate from inexhaustible sources and can be utilized to decrease the issue of plastic waste that .
Chapter 77 - Chemical Processing CHEMICAL INDUSTRY. L. De Boer* *Adapted from 3rd edition, Encyclopaedia of Occupational Health and Safety.
The business of the chemical industry is to change the chemical structure of natural materials in order to derive products of value to other industries or in daily life. UPDATED 12 September Preface. When I was a boy, oddities fascinated me, particularly if they appeared to make no sense.
Historical oddities or anomalous news stories especially attracted my interest, lingering in my mind for years to come.