Iron is considered a plant micronutrient. Iron is absorbed by plants as the ferrous ion (Fe+2), which is necessary for the formation of chlorophyll and functions in some of the enzymes of the plant’s respiratory system (Schneider et al., 1968). Much of the iron in well-drained soils is in the ferric (Fe+3) form, which is unavailable to plants. Iron deficiencies may result if the soil minerals do not gradually release ferrous (Fe+2) iron to replace that which is being oxidized to ferric iron over time (Thompson and Troeh, 1973). Iron deficiencies can also result from an excess of manganese and possibly copper (Sommer,1945). Manganese and copper are oxidizing agents that convert ferrous irons to the more insoluble ferric form. Iron deficiencies caused by manganese toxicity occur in acidic soils that otherwise would supply adequate iron for plant growth (Thompson and Troeh, 1973).
Iron is recognized as an essential element as early as 1845. Iron is essential for plant growth, and is generally considered to be a micronutrient. Iron is necessary for the formation of chlorophyll and functions in some of the enzymes of the respiratory system. Iron is an abundant element in rocks and soils, but it is also one of the most commonly deficient micronutrients. This problem is associated with the extremely insoluble nature of certain compounds of ferric (Fe+3) iron. These compounds accumulate in highly weathered soils and are major constituents of the red soils of tropical regions. Fossil remnants of some ancient soils contain enough iron to serve as iron ore. These compound, however, are too insoluble to meet plant needs, even as a micronutrient (Thompson and Troeh, 1973).
ITEM 144: assorted music cassette tapes with handmade covers Found on: 6/15/15 Materials: hard plastic, polyester film, cobalt, iron oxide, paper Damage/wear: none Provenance: tapes made in Japan, recorded in the US Factory/production details: These tapes were made by Sony, Maxell, TDK, and Denon. For details on Sony, see Item 113, Sony portable Trinitron color TV. For details on Maxell, see Item 098, home VHS recording of Point Break (1991). For details on TDK, see Item 107, box of TDK MF-2DD multicolor double-sided floppy disks with a letter inside. Denon is a company that started out as Denki Onkyo Kabushikigaisha, part of the Japan Recorders Corporation, in 1910. It participated in a series of mergers over the course of the 20th century, ultimately becoming a brand name owned by Nippon Columbia. (The insert in the Denon tapes has a Nippon Columbia Co., Ltd. address.) It began producing audio cassette tapes in 1964. In 2001 Denon was spun off as a separate company; it continues to make consumer audio equipment. Date or date range: 1990s Still in production: no Rare: yes Still attainable from: nowhere Value: arguably priceless. Blank cassettes were $3-4 ($7-8 adjusted for inflation) for a pack of three in the 1990s. Use: This is – possibly only part of – someone’s music collection. It’s mostly comprised of punk and alt-rock albums recorded in the 1980s and 90s but with some exceptions (one classical cassette, some jazz, Velvet Underground etc.). The musicians represented range from well known (Nirvana, Sonic Youth) to local / less well known (Sister Double Happiness), with one original recording (Stephen Bartholomew Clarke). The owner of these tapes made the covers from Xerox-ed images, cutouts from magazines, and in one case a luggage tag. The owner also hand-wrote the titles on the tapes as well as the track listings on the provided inserts (Figure 10). The following is a list of the tape image, tape type, and music for each tape. FIGURES 1-2 1. dialogue bubble saying “Cause in New York City” / Sony HF90: Nick Cave and the Bad Seeds, Kicking Against the Pricks (1986) and From Her to Eternity (1984) 2. halftone image of a man’s head / Denon HD6/100: Prince, The Black Album (1994) and unknown albums/songs by Rapeman and Blind Idiot God 3. black and white watercolor of a person’s head / TDK AR90: UT, In Gut’s House (1988) 4. tribal figures / Maxell XLII90: Firehose, If’n (1987) and Michelle Shocked, The Texas Campfire Tapes (1986) 5. red abstract composition / Sony UCX-S90: various jazz artists, Bethlehem’s Best (1958) 6. “How to Keep Your Friends” / Maxell LN46: unknown Nick Cave album 7. woman’s nude back / Maxell XLII90: The Jesus and Mary Chain, Psychocandy (1985) and Hüsker Dü, Candy Apple Grey (1986) 8. blurry animal image (donkey?) / Sony UX Turbo100: Sister Double Happiness, Heart and Mind (1991), Peter Holsapple and Chris Stamey, Mavericks (1980), and Sebadoh, Smash Your Head on the Punk Rock (1992) 9. surfers / TDK SA90: Breeders, Pod (1990) and Bongwater, Too Much Sleep (1990) 10. two young men standing / TDK SA90: Anne Be Davis, Scouts Deposit (1990) and X, More Fun in the New World (1983) 11. silly man holding a beer / Sony HF-290: Minutemen, Ballot Result (1986) 12. abstract oblong white shape with black background / TDK SA-X90: The Whitefronts, Roast Belief (1986) and Minutemen, Project Mersh (1985) FIGURES 3-4 13. drawing of a city / unknown tape type: Stephen Bartholonew Clarke, Seven Songs (1992), possibly an original recording 14. man signing “L” and “M” / Denon HD8/100: Tone Loc, Loc’ed After Dark (1989) and Ice T, Power (1988) 15. man with sombrero / Maxell XLII-S90: Tindersticks, Tindersticks (1993) and a few songs from Railroad Jerk, We Understand (1993); case is broken 16. Nicholas Africano painting of a man / TDK SA-C90: case indicates U2, October (1981) and Cramps, Off the Bone (1983) but cassette indicates Toy Dolls, Dig That Groove Baby (1993) 17. child ballerinas / Maxell XLII90: unknown albums by Poster Children and Yo La Tengo 18. yellow desert / Denon HD8/100: New Orleans Opera (band), Fire Party (1996) and Exene Cervenka, Running Sacred (1990) 19. photo of Linton Kwesi Johnson / TDK AD-C90: Linton Kwesi Johnson, Dread Beat an’ Blood (1978) and Bass Culture (1980) 20. painting of a man with a watch / unknown tape type: unknown music by Stravinsky and Beethoven, Piano Sonata Opus 3 (”and stuff”); the Stravinsky side of this tape has been painted gold 21. green wiggly lines / TDK SA90: unknown album by Fugazi 22. late check-in luggage tag / TDK SA90: De La Soul, 3 Feet High and Rising (1989) 23. D.O.A. movie poster / TDK SA90: John Zorn, Spillane (1987) and unknown album/songs by Universal Congress Of (jazz) 24. colored in xerox of men standing / unknown tape type: XTC, Homo Safari (1979) FIGURES 5-6 25. people underwater / TDK SA-C90: Velvet Underground, The Velvet Underground and Nico (1967) and Pink Floyd, Piper at the Gates of Dawn (1967) 26. Muybridge studies / TDK SA90: Pixies, Surfer Rosa (1988) and Velvet Underground, VU (1969) 27. messy colorful painting of a face / TDK SA90: Thinking Fellers, Loveyville (1991) and unknown album by Number One Cup 28. image of Run-D.M.C. / TDK SA-C90: Run-D.M.C., Raising Hell (1986) 29. man with windblown hair / Maxell UDS-II90: The Pogues, Rum Sodomy & the Lash (1985) and If I Should Fall from Grace with God (1988) 30. person with mullet / Maxell Epitaxial XLII90: Camper Van Beethoven, Telephone Free Landslide Factory (1985) 31. gun advertisements / TDK SA90: Big Black, Songs About Fucking (1987) and Earth Atomizer Let’s Go (1985) and Scratch Acid, Just Keep Eating (1986) 32. industrial outdoor scene / Maxell XLII90: Sonic Youth, Daydream Nation (1988) and music from the film Wings of Desire (1988) 33. Mike Tyson KO’d magazine cover / Maxell Epitaxial XLII90: Hüsker Dü, Flip Your Wig (1985) and Sonic Youth, Bad Moon Rising (1985) 34. skull graffiti / Maxell Epitaxial UDXLII90: Hüsker Dü, Everything Falls Apart (1983) and various songs by The Replacements 35. white with blue and purple border / TDK AD-C90: The Art of Noise, (Who’s Afraid Of?) The Art of Noise! (1984) and Run-D.M.C., King of Rock (1985) 36. leaf / Maxell XLII-S100: Blind Idiot God, Undertow (1989) and Big Boys, No Matter How Long the Line is at the Cafeteria, There’s Always a Seat (1985) and Fun, Fun, Fun (1982) FIGURE 7 37. painting with scales / Maxell XLII90: Pavement, Wowee Zowee (1995) 38. utility pole / Denon HD7/100: John Doe, Meet John Doe (1990) and Exene, Old Wives Tales (1989) 39. young girl running / TDK SA90: Nirvana, Nevermind (1991) and Unrest, Imperial f.f.r.r. (1992) 40. ski masks / TDK SA90: Dinosaur Jr., You’re Living All Over Me (1987) and Pixies, Bossanova (1990) FIGURE 8 (DETAIL) 41. men in suits singing or yelling / TDK AD90: Sonic Youth, Evol (1986)and The Church, The Blurred Crusade (1982)
The concept known as redox has a fundamental part to play in chemistry, including its specialised ramifications of geochemistry and mineralogy. It essentially signals the propensity of an element or compound to give or take electrons, related to whether it has a surplus of them or a lack of them in the outer shell surrounding the atomic nucleus. While this affects the properties of minerals on many levels one of the most obvious ones is colour, since some elements exist in nature in either form, depending on their geological history. Iron is an excellent example, thriving in both 2++ (ie it lacks two negatively charged electrons in its outer shell and has a net charge therefore of +2, meaning that to form a chemical bond it needs to accept 2 electrons from the other unit) and 3+++ versions. The most common electron donor in these cases is oxygen (single -)
In the 1950s, ocean-going research vessels recorded puzzling data based on the magnetism of the ocean floor. It was determined that the rock of the ocean floor had alternating bands of embedded iron oxides that pointed north and south. Thus, in 1963, the theory of the reversal of the earth’s magnetic field was proposed and it has been a fundamental of earth science since.
Scientists believe that the earth’s magnetism is created by slow movements in the liquid outer core, caused by the rotation of the earth. The generation of the earth’s magnetic field is a continuous, but variable, process that causes change in not only the intensity of the magnetic field, but also causes the Magnetic North Pole to move as well as the reversal of the earth’s entire magnetic field.
Lava, which hardens into rock, contains grains of iron oxides that point toward the magnetic pole as the rock solidifies. Thus, these grains are permanent records of the location of the earth’s magnetic field. As new crust is created on the ocean floor (such as at the Mid-Atlantic ridge), the new crust solidifies, with its iron oxide acting like miniature compass needles. Scientists have matched the magnetic bands on either side of the Mid-Atlantic ridge out to the edges of the ocean. To determine the distance between the Americas and Europe and Africa at any point since Pangea, one need only to “roll back” the oceanic crust to the appropriate matching magnetic bands on either side of the ridge. Magnetic reversals helped to prove the theory of plate tectonics and continental drift.
The earth’s magnetic field has reversed approximately 170 times over the last 100 million years. The intensity of the magnetic field has been decreasing over time since it has been measured and some scientists expect that at the current rate of decline, there may be another magnetic reversal in approximately 2000 years. That should be enough time to replace all of our compasses.
Unexpected Beauty by FEI Company Via Flickr: It’s a contamination of iron oxide involving the tungsten filament of an automotive light bulb.
Courtesy of Mr. FRANCISCO RANGEL , MCT/INT
Instrument used: Quanta SEM
Horizontal Field Width: 75.3 μm
Vacuum: 9.27e-7 mbar
Voltage: 20 kV
Working Distance: 10.8
Detector: Mix: SE plus BSE.