How it s made is a documentary television series that premiered on january 6 2001 on the discovery channel in canada and science in the united states. Other elements include fats salts and wax.
How Is Silk Obtained From Silkworm
Making silk fabric demands great deal of handling and processing.
Silk how its made. Spun silk is comprised of broken filaments that have been processed into a yarn. It actually comes from the cocoon of the silk worm. About press copyright contact us creators advertise developers terms privacy policy safety how youtube works test new features press copyright contact us creators.
The fiber called fibroin makes up between 75 and 90 and sericin the gum secreted by the caterpillar to glue the fiber into a cocoon comprises about 10 25 of silk. This is one of the reasons why it is also one of the most expensive fibers. While the rayon is made from renewable resources usually bamboo or beech trees its processing does require the use of chemicals as well as high use of water and energy.
To get the billions of cocoons necessary to have a viable silk industry by some estimates about 10 billion each year the worms are cultivated. Despite its immense tensile strength silk is generally prized for other reasons. Most silk is also processed with chemicals to improve its look feel and wearability.
Generally one cocoon produces between 1 000 and 2 000 feet of silk filament made essentially of two elements. Have you ever wondered how is silk made. Crinkly fabrics are made with crepe while sheer cloth is made with single thread.
Silk is the strongest natural textile in the world. Silk is one of the most beautiful textile fibers and is even considered the queen of textiles. This textile was just recently surpassed in strength by a lab engineered biomaterial but it remains the strongest fabric made through natural processes.
As one of the cornerstones of the u s. It has many uses ranging from recreation to scientific analysis to emergency response.
Maps Gates Of The Arctic National Park Preserve U S National Park Service
Depending on latitude the area portrayed by the 7 5 minute series ranges from 49 to 64 square miles.
Us government topographic maps. The project was launched in late 2009 and the term us topo refers specifically to quadrangle topographic maps published in 2009 and later. Current generation topographic maps are created from digital gis databases and are branded us topo historic maps originally published as paper documents in the period. Building on the success of more than 130 years of usgs topographic mapping the us topo series is a new generation of maps of the american landscape.
Usgs topographic maps come in a variety of scales. Us topo topographic maps are produced by the national geospatial program of the u s. These are general use maps at medium scales that present elevation contour lines hydrography geographic place names and a variety of cultural features.
It takes about 57 000 7 5 minute maps to cover the 48 contiguous states. The most popular and the most detailed are the 7 5 minute or 1 24 000 scale 1 inch 2 000 feet quadrangle series. Geological survey s usgs national geospatial program the national map is a collaborative effort among the usgs and other federal state and local partners to improve and deliver topographic information for the nation.
A magnifying glass can be used to focus light such as to concentrate the sun s radiation to create a hot spot at the focus for fire starting. These usually cost between 2 and 10.
What Magnifying Glass Do I Need For Biology Field Work
Free shipping on your first order shipped by amazon.
Magnifying lenses for glasses. The most affordable magnifying glasses have a single lens with one magnification power and aren t lighted. 4 2 out of 5 stars 788. Magnifying power is measured in diopters each diopter increases the size of the object in view by 25.
21 99 21 99 21 99 count get it as soon as tue sep 15. Yoctosun rechargeable head magnifier glasses eyeglasses magnifier with 2 led lights and detachable lenses 1 5x 2 5x 3 5x 5x best magnifying glasses for reading and hobby. The level of magnification depends on the strength of the lens.
These magnifying eyeglasses are not available in stores. A plastic fresnel lens sold as a tv screen magnifier a sheet magnifier consists of many very narrow concentric ring shaped lenses such that the combination acts as a single lens but is much thinner. They typically have two or three led lights too.
These glasses protect your eyes from harmful infrared light while welding. Mid range magnifying glasses usually have built in lighting and two lenses each with different magnification powers. These glasses protect your eyes from harmful infrared light while welding.
Magnifying lenses enhance details up to 163 larger to make them easier to see. These professional eyewear are twice the magnifying power of typical readers. They sit comfortably on the bridge of your nose.
Magnifiers with a natural glass lens are highly scratch resistant and easy to clean glass lenses are a good choice around acids and grinding maybe taking place optically most glass lenses are inferior to high grade acrylic lenses and can break if dropped. These are not readers. The lens is usually mounted in a frame with a handle.
A magnifying glass uses a strong lens to make an object or reading material underneath the glass appear larger than it actually is. A magnifying glass is a convex lens that is used to produce a magnified image of an object. Magnifying eyeglasses designed for the professional.
Glasses have a padded nosepiece for comfort. Magnifying lenses enhance details up to 163 larger to make them easier to see. They make everything larger and clearer.
Jude heart valve include a static magnetic field of 1 5 tesla or 3 0 tesla a maximum spatial gradient less than or equal to 3 000 gauss per centimeter and a maximum whole body averaged specific absorption rate of 2 0 watts per kilogram for 15 minutes of scanning in normal operating mode according to st. One of the tissue valve replacement types that i constantly receive questions about is the biocore aortic valve from st.
St Jude Medical Heart Valve Demonstration 31m Unit National Museum Of American History
The use of an inappropriately small bioprosthesis may result in suboptimal hemodynamics.
St jude heart valves. A white dacron sewing ring surrounds the valve. Jude medical aortic mechanical heart valve standard cuff 17mm. It s interesting to note that the epic stented valve is built upon the architecture of the biocore aortic valve.
As you may have seen st. Jude medical valve and repair products. Jude medical sjm artificial heart valve a bi leaflet valve made of pyrolytic carbon.
Citation needed companies that manufacture heart valves include edwards lifesciences medtronic abbott st. Jude medical valves and annuloplasty rings during mri this information is intended to address safety and effects of magnetic resonance imaging mri on st. Accelerated deterioration due to calcific degeneration of the epic and epic supra valve may occur in.
The first surgical implant with a sjm heart valve was carried out in october 1977. All sjm heart valves and annuloplasty rings are mri safe 3 tesla or less. This includes the models listed.
Jude medical aortic mechanical heart valve standard cuff 19mm. This is one of the early versions of the st. Of 2 982 aortic avr and 1 498 mitral valve replacements mvr concomitant coronary artery bypass grafting was performed on 42 and 33 respectively.
Mechanical valves come in three main types caged ball tilting disc and bileaflet with various modifications on these designs. Children adolescents or young adults. Jude medical was founded in 1976 to further develop bi leaflet artificial heart valves which were originally created in 1972 at the university of minnesota.
Jude medical livanova cryolife and lifenet health. Jude just received fda approval for its epic stented valve. Jude medical s bi leaflet valve was developed in large part by dr.
As of 2015 mri conditions that are considered safe for patients with a st. From october 1977 to october 2002 4 480 patients age range 17 to 94 years. Jude medical mechanical heart valves models include xxagn 751 xxagfn 756 xxahpj 505 or xxmhpj 505 xxaehpj 505 xxafhpj 505 xxaj 501 or xxmj 501 xxaecj 502 or xxmecj 502 xxatj 503 or xxmtj 503 xxmetj 504.
Jude medical heart valve. Jude medical employee don hanson. Use only the st.
Average 64 13 years underwent single valve replacement with the st. There are four pivot points and the edges of the donut are not as rounded as later models. Demetre nicoloff of the university of minnesota and st.
Jude medical bioprosthetic heart valve sizer set model b1000 with the epic and epic supra valves.