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Sample records for magnesium alloy-zr

  1. Magnesium

    MedlinePlus

    ... supplements are available? Magnesium is available in multivitamin-mineral supplements and other dietary supplements . Forms of magnesium ... higher intakes of magnesium have a higher bone mineral density , which is important in reducing the risk ...

  2. Magnesium

    NASA Astrophysics Data System (ADS)

    Bechtel, H.; Bulian, W.; Bungardt, K.; Gürs, K.; Gürs, U.; Helling, W.; Kyri, H.; Laue, H. J.; Mahler, W.; Matting, A.; Meyer, F. R.; Mialki, W.; Ritter, F.; Ruge, J.; Saur, G.; Simon, W.; Strnat, K.; Weber, R.; Weigand, H. H.; Weik, H.; Ziesler, H.; Borchers, Heinz; Schmidt, Ernst

    Magnesium wird überwiegend durch Schmelzflußelektrolyse hergestellt. Das dabei anfallende Reinmagnesium hat einen Mg-Gehalt von etwa 99,9%. Hauptbeimengung ist das Eisen; Silizium und Aluminium sind nur in Spuren vorhanden. Der Anwendungsumfang des Reinmagnesiums ist gering; dagegen werden Magnesiumlegierungen zunehmend, insbesondere für den Druckguß verwendet. Neben den bis etwa zum Jahre 1950 allein gebräuchlichen Mg-Mn-, Mg-Al- und Mg-Al-Zn-Legierungen werden heute mehr und mehr die besonders warmfesten Legierungen mit Zusätzen von Zirkon, Thorium und Seltenen Erden hergestellt (siehe dazu auch Abschnitt Seltene Erden). Als Umhüllungsmaterial für Uranstäbe dient die Legierung Magnox A 12, die nach [H 3] neben 1 % Al noch geringe Mengen an Ca und Ba enthält. In den in Deutschland üblichen Kurzzeichen (DIN 1729) werden die chemischen Symbole und der ungefähre Gehalt der wichtigsten Legierungselemente angegeben. Gußlegierungen werden zusätzlich durch ein G (Sandguß oder Kokillenguß) oder ein D (Druckguß) gekennzeichnet (siehe Tab. 5).

  3. Magnesium Gluconate

    MedlinePlus

    Magnesium gluconate is used to treat low blood magnesium. Low blood magnesium is caused by gastrointestinal disorders, prolonged vomiting or ... disease, or certain other conditions. Certain drugs lower magnesium levels as well.This medication is sometimes prescribed ...

  4. Magnesium basics

    PubMed Central

    Ketteler, Markus

    2012-01-01

    As a cofactor in numerous enzymatic reactions, magnesium fulfils various intracellular physiological functions. Thus, imbalance in magnesium status—primarily hypomagnesaemia as it is seen more often than hypermagnesaemia—might result in unwanted neuromuscular, cardiac or nervous disorders. Measuring total serum magnesium is a feasible and affordable way to monitor changes in magnesium status, although it does not necessarily reflect total body magnesium content. The following review focuses on the natural occurrence of magnesium and its physiological function. The absorption and excretion of magnesium as well as hypo- and hypermagnesaemia will be addressed. PMID:26069819

  5. Magnesium Oxide

    MedlinePlus

    ... repeatedly. Magnesium oxide also is used as a dietary supplement when the amount of magnesium in the diet ... any products such as vitamins, minerals, or other dietary supplements. You should bring this list with you each ...

  6. Magnesium Hydroxide

    MedlinePlus

    Magnesium hydroxide is used on a short-term basis to treat constipation.This medication is sometimes prescribed ... Magnesium hydroxide come as a tablet and liquid to take by mouth. It usually is taken as ...

  7. Electronic structures, magnetic properties and half-metallicity in Heusler alloys Zr2CoZ (Z=Al, Ga, In, Sn)

    NASA Astrophysics Data System (ADS)

    Yan, Peng-Li; Zhang, Jian-Min; Xu, Ke-Wei

    2015-10-01

    The electronic structures, magnetic properties, and half-metallicity of full-Heusler alloys Zr2 CoZ (Z=Al, Ga, In, Sn) with the Hg2 CuTi -type structure have been studied by using the first-principles projector augmented wave (PAW) potential within the generalized gradient approximation (GGA). The Zr2 CoZ (Z=Al, Ga, In, Sn) are found to be half-metallic ferrimagnets within a certain range of the lattice constant. The total magnetic moments (μt) of the Zr2 CoZ alloys are calculated to be 2 for Z=Al, Ga, In and 3 for Z=Sn, linearly scaled with the total number of valence electrons (Zt) by μt =Zt - 18 . The origin of the band gap for these half-metallic alloys is well understood. These new Zr-based Heusler alloys are the ideal candidates for spintronic devices.

  8. Devitrification of Mechanically Alloyed Zr-Ti-Nb-Cu-Ni-Al Glassy Powders Studied by Time-Resolved X-ray Diffraction

    SciTech Connect

    Scudino, S.; Sordelet, D.J.; Eckert, J.

    2009-04-13

    The crystallization of mechanically alloyed Zr{sub 67}Ti{sub 6.14}Nb{sub 1.92}Cu{sub 10.67}Ni{sub 8.52}Al{sub 5.75} glassy powder is investigated by time-resolved X-ray diffraction. The powder displays a multi-step crystallization behavior characterized by the formation of a metastable nanoscale quasicrystalline phase during the first stage of the crystallization process. At higher temperatures, coinciding with the second crystallization event, the amorphous-to-quasicrystalline transformation is followed by the precipitation of the tetragonal Zr{sub 2}Cu phase (space group I4/mmm) and the tetragonal Zr{sub 2}Ni phase (space group I4/mcm). The transformations are gradual and the quasicrystals and the subsequent phases coexist over a temperature interval of about 25K.

  9. Magnesium compounds

    USGS Publications Warehouse

    Kramer, D.A.

    2010-01-01

    Seawater and natural brines accounted for about 40 percent of U.S. magnesium compounds production in 2009. Dead-burned magnesia was produced by Martin Marietta Magnesia Specialties from well brines in Michigan. Caustic-calcined magnesia was recovered from seawater by Premier Chemicals in Florida, from well brines in Michigan by Martin Marietta and from magnesite in Nevada by Premier Chemicals. Intrepid Potash-Wendover, and Great Salt Lake Minerals Corp. recovered magnesium chloride brines from the Great Salt Lake in Utah. Magnesium hydroxide was produced from seawater by SPI Pharma in Delaware and Premier Chemicals in Florida, and by Martin Marietta from its operation mentioned above.

  10. Magnesium compounds

    USGS Publications Warehouse

    Kramer, D.A.

    2011-01-01

    Seawater and natural brines accounted for about 54 percent of U.S. magnesium compounds production in 2010. Dead-burned magnesia was produced by Martin Marietta Magnesia Specialties from well brines in Michigan. Caustic-calcined magnesia was recovered from seawater by Premier Magnesia in Florida, from well brines in Michigan by Martin Marietta and from magnesite in Nevada by Premier Magnesia. Intrepid Potash-Wendover and Great Salt Lake Minerals Corp. recovered magnesium chloride brines from the Great Salt Lake in Utah. Magnesium hydroxide was produced from seawater by SPI Pharma in Delaware and Premier Magnesia in Florida, and by Martin Marietta from its operation mentioned above.

  11. Magnesium Test

    MedlinePlus

    ... Mg; Mag Formal name: Magnesium Related tests: Calcium , Potassium , Phosphorus , PTH , Vitamin D At a Glance Test ... can, over time, cause persistently low calcium and potassium levels, it may be checked to help diagnose ...

  12. Production of magnesium metal

    DOEpatents

    Blencoe, James G [Harriman, TN; Anovitz, Lawrence M [Knoxville, TN; Palmer, Donald A [Oliver Springs, TN; Beard, James S [Martinsville, VA

    2010-02-23

    A process of producing magnesium metal includes providing magnesium carbonate, and reacting the magnesium carbonate to produce a magnesium-containing compound and carbon dioxide. The magnesium-containing compound is reacted to produce magnesium metal. The carbon dioxide is used as a reactant in a second process. In another embodiment of the process, a magnesium silicate is reacted with a caustic material to produce magnesium hydroxide. The magnesium hydroxide is reacted with a source of carbon dioxide to produce magnesium carbonate. The magnesium carbonate is reacted to produce a magnesium-containing compound and carbon dioxide. The magnesium-containing compound is reacted to produce magnesium metal. The invention further relates to a process for production of magnesium metal or a magnesium compound where an external source of carbon dioxide is not used in any of the reactions of the process. The invention also relates to the magnesium metal produced by the processes described herein.

  13. Production of magnesium metal

    DOEpatents

    Blencoe, James G.; Anovitz, Lawrence M.; Palmer, Donald A.; Beard, James S.

    2012-04-10

    A process of producing magnesium metal includes providing magnesium carbonate, and reacting the magnesium carbonate to produce a magnesium-containing compound and carbon dioxide. The magnesium-containing compound is reacted to produce magnesium metal. The carbon dioxide is used as a reactant in a second process. In another embodiment of the process, a magnesium silicate is reacted with a caustic material to produce magnesium hydroxide. The magnesium hydroxide is reacted with a source of carbon dioxide to produce magnesium carbonate. The magnesium carbonate is reacted to produce a magnesium-containing compound and carbon dioxide. The magnesium-containing compound is reacted to produce magnesium metal. The invention also relates to the magnesium metal produced by the processes described herein.

  14. Magnesium compounds

    USGS Publications Warehouse

    Kramer, D.A.

    2012-01-01

    Seawater and natural brines accounted for about 57 percent of magnesium compounds produced in the United States in 2011. Dead-burned magnesia was produced by Martin Marietta Magnesia Specialties LLC from well brines in Michigan. Caustic-calcined magnesia was recovered from seawater by Premier Magnesia LLC in Florida, from well brines in Michigan by Martin Marietta and from magnesite in Nevada by Premier Magnesia. Intrepid Potash Wendover LLC and Great Salt Lake Minerals Corp. recovered magnesium chloride brines from the Great Salt Lake in Utah. Magnesium hydroxide was produced from seawater by SPI Pharma Inc. in Delaware and Premier Magnesia in Florida, and by Martin Marietta from its brine operation in Michigan.

  15. Magnesium compounds

    USGS Publications Warehouse

    Kramer, D.A.

    2002-01-01

    Seawater and natural brines accounted for about 60% of US magnesium compounds production in 2001. Dead-burned and caustic-calcined magnesias were recovered from seawater in Florida by Premier Chemicals. They were also recovered from Michigan well brines by Dow Chemical, Martin Marietta Magnesia Specialties and Rohm & Haas. And Premier Chemicals recovered dead-burned and caustic-calcined magnesias from magnesite in Nevada. Reilly Industries and Great Salt Lake Minerals recovered magnesium chloride brines from the Great Salt Lake in Utah.

  16. Magnesium compounds

    USGS Publications Warehouse

    Kramer, D.A.

    2004-01-01

    Dead-burned and caustic-calcined magnesias were recovered from seawater by Premier Chemicals in Florida; from well brines in Michigan by Dow Chemical, Martin Marietta Magnesia Specialties, and Rohm & Haas; and from magnesite in Nevada by Premier Chemicals. Reilly Industries and Great Salt Lake Minerals recovered magnesium chloride brines from the Great Salt Lake in Utah.

  17. Magnesium compounds

    USGS Publications Warehouse

    Kramer, D.A.

    2007-01-01

    Seawater and natural brines accounted for about 52 percent of U.S. magnesium compounds production in 2006. Dead-burned magnesia was produced by Martin Marietta Magnesia Specialties from well brines in Michigan. Caustic-calcined magnesia was recovered from sea-water by Premier Chemicals in Florida; from well brines in Michigan by Martin Marietta and Rohm and Haas; and from magnesite in Nevada by Premier Chemicals. Intrepid Potash-Wendover and Great Salt Lake Minerals recovered magnesium chloride brines from the Great Salt Lake in Utah. Magnesium hydroxide was produced from brucite by Applied Chemical Magnesias in Texas, from seawater by SPI Pharma in Delaware and Premier Chemicals in Florida, and by Martin Marietta and Rohm and Haas from their operations mentioned above. About 59 percent of the magnesium compounds consumed in the United States was used for refractories that are used mainly to line steelmaking furnaces. The remaining 41 percent was consumed in agricultural, chemical, construction, environmental and industrial applications.

  18. Magnesium compounds

    USGS Publications Warehouse

    Kramer, D.A.

    2001-01-01

    Seawater and natural brines accounted for about 63% of US magnesium compounds production during 2000. Premier Services in Florida, Dow Chemical in Michigan, Martin Marietta Magnesia Specialties, and Rohm & Haas recovered dead-burned and caustic-calcined magnesias from seawater. And Premier Services' recoveries, in Nevada, were from magnasite.

  19. Magnesium compounds

    USGS Publications Warehouse

    Kramer, D.A.

    2003-01-01

    Seawater and natural brines accounted for about 60 percent of U.S. magnesium compounds production during 2002. Dead-burned and caustic-calcined magnesias were recovered from seawater by Premier Chemicals in Florida. They were also recovered from well brines in Michigan by Dow Chemical, Martin Marietta Magnesia Specialties and Rohm & Haas. And they were recovered from magnesite in Nevada by Premier Chemicals.

  20. Magnesium compounds

    USGS Publications Warehouse

    Kramer, D.A.

    2006-01-01

    In 2005, seawater and natural brines accounted for 51% of US magnesium compounds production. World magnesia production was estimated to be 14.5 Mt. Most of the production came from China, North Korea, Russia and Turkey. Although no specific production figures are available, Japan and the United States are estimated to account for almost one-half of the world's capacity from seawater and brines.

  1. Magnesium in diet

    MedlinePlus

    Diet - magnesium ... Magnesium is needed for more than 300 biochemical reactions in the body. It helps to maintain normal ... There is ongoing research into the role of magnesium in preventing and managing disorders such as high ...

  2. Low magnesium level

    MedlinePlus

    Low magnesium level is a condition in which the amount of magnesium in the blood is lower than normal. The medical ... that convert or use energy ( metabolism ). When the level of magnesium in the body drops below normal, ...

  3. Characterization of the interface between the bulk glass forming alloy Zr{sub 41}Ti{sub 14}Cu{sub 12}Ni{sub 10}Be{sub 23} with pure metals and ceramics

    SciTech Connect

    Schroers, Jan; Samwer, Konrad; Szuecs, Frigyes; Johnson, William L.

    2000-07-01

    The reaction of the bulk glass forming alloy Zr{sub 41}Ti{sub 14}Cu{sub 12}Ni{sub 10}Be{sub 23} (Vit 1) with W, Ta, Mo, AlN, Al{sub 2}O{sub 3}, Si, graphite, and amorphous carbon was investigated. Vit 1 samples were melted and subsequently solidified after different processing times on discs of the different materials. Sessile drop examinations of the macroscopic wetting of Vit 1 on the discs as a function of temperature were carried out in situ with a digital optical camera. The reactions at the interfaces between the Vit 1 sample and the different disc materials were investigated with an electron microprobe. The structure and thermal stability of the processed Vit 1 samples were examined by x-ray diffraction and differential scanning calorimetry. The results are discussed in terms of possible applications for composite materials. (c) 2000 Materials Research Society.

  4. Magnesium and sudden death.

    PubMed

    Leary, W P; Reyes, A J

    1983-10-22

    Magnesium deficiency may result from reduced dietary intake of the ion or increased losses in sweat, urine or faeces. Stress potentiates magnesium deficiency, and an increased incidence of sudden death associated with ischaemic heart disease is found in some areas in which soil and drinking water lack magnesium. Furthermore, it has been demonstrated experimentally that reduction of the plasma magnesium level is associated with arterial spasm. Careful studies are required to assess the clinical importance of magnesium and the benefits of magnesium supplementation in man. PMID:6353622

  5. Choline Magnesium Trisalicylate

    MedlinePlus

    Choline magnesium trisalicylate is used to relieve the pain, tenderness, inflammation (swelling), and stiffness caused by arthritis and painful ... used to relieve pain and lower fever. Choline magnesium trisalicylate is in a class of nonsteroidal anti- ...

  6. Magnesium and Space Flight

    PubMed Central

    Smith, Scott M.; Zwart, Sara R.

    2015-01-01

    Magnesium is an essential nutrient for muscle, cardiovascular, and bone health on Earth, and during space flight. We sought to evaluate magnesium status in 43 astronauts (34 male, 9 female; 47 ± 5 years old, mean ± SD) before, during, and after 4–6-month space missions. We also studied individuals participating in a ground analog of space flight (head-down-tilt bed rest; n = 27 (17 male, 10 female), 35 ± 7 years old). We evaluated serum concentration and 24-h urinary excretion of magnesium, along with estimates of tissue magnesium status from sublingual cells. Serum magnesium increased late in flight, while urinary magnesium excretion was higher over the course of 180-day space missions. Urinary magnesium increased during flight but decreased significantly at landing. Neither serum nor urinary magnesium changed during bed rest. For flight and bed rest, significant correlations existed between the area under the curve of serum and urinary magnesium and the change in total body bone mineral content. Tissue magnesium concentration was unchanged after flight and bed rest. Increased excretion of magnesium is likely partially from bone and partially from diet, but importantly, it does not come at the expense of muscle tissue stores. While further study is needed to better understand the implications of these findings for longer space exploration missions, magnesium homeostasis and tissue status seem well maintained during 4–6-month space missions. PMID:26670248

  7. Magnesium and Space Flight

    NASA Technical Reports Server (NTRS)

    Smith, Scott M.; Zwart, Sara R.

    2016-01-01

    Magnesium is an essential nutrient for muscle, cardiovascular, and bone health on Earth, and during space flight. We sought to evaluate magnesium status in astronauts before, during, and after space missions, in 43 astronauts (34 male, 9 female) on 4-6 month space flight missions. We also studied individuals participating in a ground analog of space flight, (head-down tilt bed rest, n=27, 35 +/- 7 y). We evaluated serum concentration and 24-hour urinary excretion of magnesium along with estimates of tissue magnesium status from sublingual cells. Serum magnesium increased late in flight, while urinary magnesium excretion was higher over the course of 180-d space missions. Urinary magnesium increased during flight but decreased significantly at landing. Neither serum nor urinary magnesium changed during bed rest. For flight and bed rest, significant correlations existed between the area under the curve of serum and urinary magnesium and the change in total body bone mineral content. Tissue magnesium concentration was unchanged after flight and bed rest. Increased excretion of magnesium is likely partially from bone and partially from diet, but importantly, it does not come at the expense of muscle tissue stores. While further study is needed to better understand the implications of these findings for longer space exploration missions, magnesium homeostasis and tissue status seem well maintained during 4- to 6-month space missions.

  8. Magnesium and Space Flight.

    PubMed

    Smith, Scott M; Zwart, Sara R

    2015-12-01

    Magnesium is an essential nutrient for muscle, cardiovascular, and bone health on Earth, and during space flight. We sought to evaluate magnesium status in 43 astronauts (34 male, 9 female; 47 ± 5 years old, mean ± SD) before, during, and after 4-6-month space missions. We also studied individuals participating in a ground analog of space flight (head-down-tilt bed rest; n = 27 (17 male, 10 female), 35 ± 7 years old). We evaluated serum concentration and 24-h urinary excretion of magnesium, along with estimates of tissue magnesium status from sublingual cells. Serum magnesium increased late in flight, while urinary magnesium excretion was higher over the course of 180-day space missions. Urinary magnesium increased during flight but decreased significantly at landing. Neither serum nor urinary magnesium changed during bed rest. For flight and bed rest, significant correlations existed between the area under the curve of serum and urinary magnesium and the change in total body bone mineral content. Tissue magnesium concentration was unchanged after flight and bed rest. Increased excretion of magnesium is likely partially from bone and partially from diet, but importantly, it does not come at the expense of muscle tissue stores. While further study is needed to better understand the implications of these findings for longer space exploration missions, magnesium homeostasis and tissue status seem well maintained during 4-6-month space missions. PMID:26670248

  9. Magnesium industry overview

    SciTech Connect

    Clow, B.B.

    1996-10-01

    Magnesium products provide an excellent strength-to-weight ratio, good fatigue strength, high impact strength, good corrosion resistance, high-speed machinability, and good thermal and electrical conductivities. As a result, applications are expanding in almost every industry. Dozens of automotive components are now made of magnesium, including steering wheels, valve covers, and seat frames. Magnesium alloys are also used in computer housings, in-line roller skates, golf clubs, tennis racquets, and baseball bats. Good strength and stiffness at both room and elevated temperatures make magnesium alloys especially valuable for aerospace applications. This article presents an overview of magnesium technology, world production, increasing demand, and recycling.

  10. Magnesium and the Athlete.

    PubMed

    Volpe, Stella Lucia

    2015-01-01

    Magnesium is the fourth most abundant mineral and the second most abundant intracellular divalent cation in the body. It is a required mineral that is involved in more than 300 metabolic reactions in the body. Magnesium helps maintain normal nerve and muscle function, heart rhythm (cardiac excitability), vasomotor tone, blood pressure, immune system, bone integrity, and blood glucose levels and promotes calcium absorption. Because of magnesium's role in energy production and storage, normal muscle function, and maintenance of blood glucose levels, it has been studied as an ergogenic aid for athletes. This article will cover the general roles of magnesium, magnesium requirements, and assessment of magnesium status as well as the dietary intake of magnesium and its effects on exercise performance. The research articles cited were limited from those published in 2003 through 2014. PMID:26166051

  11. Magnesium in depression.

    PubMed

    Serefko, Anna; Szopa, Aleksandra; Wlaź, Piotr; Nowak, Gabriel; Radziwoń-Zaleska, Maria; Skalski, Michał; Poleszak, Ewa

    2013-01-01

    Magnesium is one of the most essential mineral in the human body, connected with brain biochemistry and the fluidity of neuronal membrane. A variety of neuromuscular and psychiatric symptoms, including different types of depression, was observed in magnesium deficiency. Plasma/serum magnesium levels do not seem to be the appropriate indicators of depressive disorders, since ambiguous outcomes, depending on the study, were obtained. The emergence of a new approach to magnesium compounds in medical practice has been seen. Apart from being administered as components of dietary supplements, they are also perceived as the effective agents in treatment of migraine, alcoholism, asthma, heart diseases, arrhythmias, renal calcium stones, premenstrual tension syndrome etc. Magnesium preparations have an essential place in homeopathy as a remedy for a range of mental health problems. Mechanisms of antidepressant action of magnesium are not fully understood yet. Most probably, magnesium influences several systems associated with development of depression. The first information on the beneficial effect of magnesium sulfate given hypodermically to patients with agitated depression was published almost 100 years ago. Numerous pre-clinical and clinical studies confirmed the initial observations as well as demonstrated the beneficial safety profile of magnesium supplementation. Thus, magnesium preparations seem to be a valuable addition to the pharmacological armamentarium for management of depression. PMID:23950577

  12. Magnesium in disease

    PubMed Central

    Wanner, Christoph

    2012-01-01

    Although the following text will focus on magnesium in disease, its role in healthy subjects during physical exercise when used as a supplement to enhance performance is also noteworthy. Low serum magnesium levels are associated with metabolic syndrome, Type 2 diabetes mellitus (T2DM) and hypertension; consequently, some individuals benefit from magnesium supplementation: increasing magnesium consumption appears to prevent high blood pressure, and higher serum magnesium levels are associated with a lower risk of developing a metabolic syndrome. There are, however, conflicting study results regarding magnesium administration with myocardial infarction with and without reperfusion therapy. There was a long controversy as to whether or not magnesium should be given as a first-line medication. As the most recent trials have not shown any difference in outcome, intravenous magnesium cannot be recommended in patients with myocardial infarction today. However, magnesium has its indication in patients with torsade de pointes and has been given successfully to patients with digoxin-induced arrhythmia or life-threatening ventricular arrhythmias. Magnesium sulphate as an intravenous infusion also has an important established therapeutic role in pregnant women with pre-eclampsia as it decreases the risk of eclamptic seizures by half compared with placebo. PMID:26069818

  13. Half-metallic and magnetic properties of full-Heusler alloys Zr2CrZ (Z=Ga, In) with Hg2CuTi-type structure: A first-principles study

    NASA Astrophysics Data System (ADS)

    Deng, Zun-Yi; Zhang, Jian-Min

    2016-01-01

    The half-metallic and magnetic properties of Heusler alloys Zr2 CrZ (Z=Ga, In) with Hg2 CuTi -type structure have been investigated by using the first-principles projector augmented wave (PAW) potential within the generalized gradient approximation (GGA). The equilibrium lattice constants are 6.635 and 6.875 Å for Zr2 CrGa and Zr2 CrIn, respectively. Under compression and expansion deformations within lattice constant ranges of 6.515-7.100 and 6.371-7.126 Å for Zr2 CrGa and Zr2 CrIn, respectively, the Zr2 CrZ (Z=Ga, In) maintain a half-metallic nature with a fixed total magnetic moment of -1 μB / f.u ., following the Slater-Pauling rule μt = Zt - 18, but the absolute values of the local magnetic moments on Zr and Cr atoms increase with increasing lattice constant.

  14. Magnesium in pregnancy.

    PubMed

    Dalton, Lynne M; Ní Fhloinn, Deirdre M; Gaydadzhieva, Gergana T; Mazurkiewicz, Ola M; Leeson, Heather; Wright, Ciara P

    2016-09-01

    Magnesium deficiency is prevalent in women of childbearing age in both developing and developed countries. The need for magnesium increases during pregnancy, and the majority of pregnant women likely do not meet this increased need. Magnesium deficiency or insufficiency during pregnancy may pose a health risk for both the mother and the newborn, with implications that may extend into adulthood of the offspring. The measurement of serum magnesium is the most widely used method for determining magnesium levels, but it has significant limitations that have both hindered the assessment of deficiency and affected the reliability of studies in pregnant women. Thus far, limited studies have suggested links between magnesium inadequacy and certain conditions in pregnancy associated with high mortality and morbidity, such as gestational diabetes, preterm labor, preeclampsia, and small for gestational age or intrauterine growth restriction. This review provides recommendations for further study and improved testing using measurement of red cell magnesium. Pregnant women should be counseled to increase their intake of magnesium-rich foods such as nuts, seeds, beans, and leafy greens and/or to supplement with magnesium at a safe level. PMID:27445320

  15. The anticarcinogenic effect of magnesium.

    PubMed

    Blondell, J M

    1980-08-01

    Evidence is reviewed supporting a hypothesis of an anticarcinogenic effect of magnesium. Animal studies reported increased cancer in rodents maintained on magnesium deficient diets and a preventive effect for rodents fed excess levels of magnesium. Epidemiologic evidence is presented that magnesium levels in water, food, and air are inversely related to cancer mortality. Magnesium may also have a role in the reduced cancer mortality experienced by people living at high altitudes. Two biologically plausible mechanisms are considered by which magnesium could prevent carcinogenesis. Intracellular magnesium may enhance the fidelity of DNA replication or magnesium on the cell membrane may prevent changes which trigger the carcinogenic process. PMID:7442590

  16. Magnesium deficiency: what's our status?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Low magnesium intake has been implicated in a broad range of cardiometabolic conditions, including diabetes, hypertension, and cardiovascular disease. Dietary magnesium and total body magnesium status have a widely-used but imperfect biomarker in serum magnesium. Despite serum magnesium’s limitation...

  17. Method for production of magnesium

    DOEpatents

    Diaz, Alexander F.; Howard, Jack B.; Modestino, Anthony J.; Peters, William A.

    1998-01-01

    A continuous process for the production of elemental magnesium is described. Magnesium is made from magnesium oxide and a light hydrocarbon gas. In the process, a feed stream of the magnesium oxide and gas is continuously fed into a reaction zone. There the magnesium oxide and gas are reacted at a temperature of about 1400.degree. C. or greater in the reaction zone to provide a continuous product stream of reaction products, which include elemental magnesium. The product stream is continuously quenched after leaving the reaction zone, and the elemental magnesium is separated from other reaction products.

  18. Method for production of magnesium

    DOEpatents

    Diaz, A.F.; Howard, J.B.; Modestino, A.J.; Peters, W.A.

    1998-07-21

    A continuous process for the production of elemental magnesium is described. Magnesium is made from magnesium oxide and a light hydrocarbon gas. In the process, a feed stream of the magnesium oxide and gas is continuously fed into a reaction zone. There the magnesium oxide and gas are reacted at a temperature of about 1400 C or greater in the reaction zone to provide a continuous product stream of reaction products, which include elemental magnesium. The product stream is continuously quenched after leaving the reaction zone, and the elemental magnesium is separated from other reaction products. 12 figs.

  19. The structural, electronic, magnetic and mechanical properties of quaternary Heusler alloys ZrTiCrZ (Z  =  Al, Ga, In, Si, Ge, Sn): a first-principles study

    NASA Astrophysics Data System (ADS)

    Yan, Peng-Li; Zhang, Jian-Min; Zhou, Bo; Xu, Ke-Wei

    2016-06-01

    The structural, electronic, magnetic and mechanical properties of the quaternary Heusler alloys ZrTiCrZ (Z  =  Al, Ga, In, Si, Ge, Sn) have been investigated firstly by using the first-principles calculations. The preferred configurations of the ZrTiCrZ alloys are all Y-type (I). At their equilibrium lattice constants, the ZrTiCrZ alloys are half-metallic (HM) ferrimagnets for Z  =  Al, Ga and In, while spin-gapless semiconductor (SGS) antiferromagnets (AFM) for Z  =  Si, Ge and Sn. The total magnetic moments {μt} of the ZrTiCrZ alloys are  ‑1 {μ\\text{B}}/\\text{f}\\text{.u}\\text{.} for Z  =  Al, Ga and In, while 0 {μ\\text{B}}/\\text{f}\\text{.u}\\text{.} for Z  =  Si, Ge and Sn, both linearly scaled with the total number of valence electrons {{Z}\\text{t}} by Slater–Pauling rule {μ\\text{t}}={{Z}\\text{t}}-18 . The elastic constants {{C}11} , {{C}12} and {{C}44} of the single crystal and the related elastic moduli G , B , E , \\upsilon and A of the polycrystalline aggregates are also calculated and used to study the mechanical stability of these alloys. Although the Curie temperatures {{T}\\text{C}} of the ZrTiCrZ alloys are overestimated by using the mean field approximation (MFA), they can be better estimated by including the exchange interactions. Finally, the HM stabilities as well as the total and atomic magnetic moments of the ZrTiCrZ alloys (Z  =  Al, Ga, In) under either hydrostatic strain or tetragonal strain are also discussed.

  20. Magnesium battery disposal characteristics

    NASA Astrophysics Data System (ADS)

    Soffer, Louis; Atwater, Terrill

    1994-12-01

    This study assesses the disposal characteristics of U.S. Army procured military magnesium batteries under current Resource Conservation and Recovery Act (RCRA) hazardous waste identification regulations administered by the U.S. Environmental Protection Agency. Magnesium batteries were tested at 100, 50, 10 and 0 percent remaining state of charge. Present findings indicate that magnesium batteries with less than 50 percent remaining charge do not exceed the federal regulatory limit of 5.0 mg/L for chromium. All other RCRA contaminates were below regulatory limits at all levels of remaining charge. Assay methods, findings, disposal requirements and design implications are discussed.

  1. Magnesium blood test

    MedlinePlus

    Magnesium - blood ... A blood sample is needed. ... When the needle is inserted to draw blood, some people feel slight pain. Others feel a prick or stinging. Afterward, there may be some throbbing or a slight bruise. This soon ...

  2. Magnesium for automotive applications

    SciTech Connect

    VanFleteren, R.

    1996-05-01

    Die cast magnesium parts are rapidly replacing steel and aluminum structural components in automotive applications, as design engineers seek to reduce assembly costs, raise fuel efficiency, and improve safety. Dozens of automotive components are now die cast from magnesium alloys, including seat stanchions, valve covers, steering wheels, and a variety of steering column components. Because of their excellent castability, complex magnesium die castings can sometimes consolidate several components and eliminate assembly steps. Highly ductile magnesium alloys such as AM60B (6% aluminum) and AM50A (5% aluminum) are important in helping to meet automotive industry crash-energy requirements for car seating and steering components. AZ91D (9% aluminum, 1% zinc) alloys are making removable rear seats in new minivans much easier to handle.

  3. Low magnesium level

    MedlinePlus

    ... in the body that convert or use energy ( metabolism ). When the level of magnesium in the body ... Walls RM, et al., eds. Rosen's Emergency Medicine: Concepts and Clinical Practice . 8th ed. Philadelphia, PA: Elsevier ...

  4. Rechargeable Magnesium Power Cells

    NASA Technical Reports Server (NTRS)

    Koch, Victor R.; Nanjundiah, Chenniah; Orsini, Michael

    1995-01-01

    Rechargeable power cells based on magnesium anodes developed as safer alternatives to high-energy-density cells like those based on lithium and sodium anodes. At cost of some reduction in energy density, magnesium-based cells safer because less susceptible to catastrophic meltdown followed by flames and venting of toxic fumes. Other advantages include ease of handling, machining, and disposal, and relatively low cost.

  5. Interstellar magnesium abundances

    NASA Technical Reports Server (NTRS)

    Murray, M. J.; Dufton, P. L.; Hibbert, A.; York, D. G.

    1984-01-01

    An improved evaluation of the Mg II 1240 A doublet oscillator strength is used in conjunction with recently published Copernicus observations to derive accurate Mg II column densities toward 74 stars. These imply an average of 40 percent of interstellar magnesium is in the gaseous phase. Magnesium depletion is examined as a function of various interstellar extinction and density parameters, and the results are briefly discussed in terms of current depletion theories.

  6. Magnesium for Future Autos

    SciTech Connect

    Nyberg, Eric A.; Luo, Alan A.; Sadayappan, Kumar; Shi, Wenfang

    2008-10-01

    In the quest for better fuel economy and improved environmental performance, magnesium may well become a metal of choice for constructing lighter, more efficient vehicles. Magnesium is the lightest structural metal, yet it has a high strength-to-weight ratio makes it comparable to steel in many applications. The world’s automakers already use magnesium for individual components. But new alloys and processing methods are needed before the metal can become economically and technologically feasible as a major automotive structural material. This article will explore the formation, challenges and initial results of an international collaboration—the Magnesium Front End Research and Development (MFERD) project—that is leveraging the expertise and resources of Canada, China and the United States to advance the creation of magnesium-intensive vehicles. The MFERD project aims to develop the enabling technologies and knowledge base that will lead to a vehicles that are 50-60 percent lighter, equally affordable, more recyclable and of equal or better quality when compared to today’s vehicles. Databases of information also will be captured in models to enable further alloy and manufacturing process optimization. Finally, a life-cycle analysis of the magnesium used will be conducted.

  7. Electrodeposition of magnesium and magnesium/aluminum alloys

    DOEpatents

    Mayer, A.

    1988-01-21

    Electrolytes and plating solutions for use in processes for electroplating and electroforming pure magnesium and alloys of aluminum and magnesium and also electrodeposition processes. An electrolyte of this invention is comprised of an alkali metal fluoride or a quaternary ammonium halide, dimethyl magnesium and/or diethyl magnesium, and triethyl aluminum and/or triisobutyl aluminum. An electrolyte may be dissolved in an aromatic hydrocarbon solvent to form a plating solution. The proportions of the component compounds in the electrolyte are varied to produce essentially pure magnesium or magnesium/aluminum alloys having varying selected compositions.

  8. Electrodeposition of magnesium and magnesium/aluminum alloys

    DOEpatents

    Mayer, Anton

    1988-01-01

    Electrolytes and plating solutions for use in processes for electroplating and electroforming pure magnesium and alloys of aluminum and magnesium and also electrodeposition processes. An electrolyte of this invention is comprised of an alkali metal fluoride or a quaternary ammonium halide, dimethyl magnesium and/or diethyl magnesium, and triethyl aluminum and/or triisobutyl aluminum. An electrolyte may be dissolved in an aromatic hydrocarbon solvent to form a plating solution. The proportions of the component compounds in the electrolyte are varied to produce essentially pure magnesium or magnesium/aluminum alloys having varying selected compositions.

  9. Electrodeposition of magnesium and magnesium/aluminum alloys

    SciTech Connect

    Mayer, A.

    1988-10-18

    Electrolytes and plating solutions for use in processes for electroplating and electroforming pure magnesium and alloys of aluminum and magnesium and also electrodeposition processes. An electrolyte of this invention is comprised of an alkali metal fluoride or a quaternary ammonium halide, dimethyl magnesium and/or diethyl magnesium, and triethyl aluminum and/or triisobutyl aluminum. An electrolyte may be dissolved in an aromatic hydrocarbon solvent to form a plating solution. The proportions of the component compounds in the electrolyte are varied to produce essentially pure magnesium or magnesium/alumnum alloys having varying selected compositions.

  10. 21 CFR 184.1434 - Magnesium phosphate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Magnesium phosphate. 184.1434 Section 184.1434 Food... Specific Substances Affirmed as GRAS § 184.1434 Magnesium phosphate. (a) Magnesium phosphate includes both magnesium phosphate, dibasic, and magnesium phosphate, tribasic. Magnesium phosphate, dibasic...

  11. An x-ray photoemission spectroscopy investigation of thermal activation induced changes in surface composition and chemical bonds of two gettering alloys: Zr sub 2 Fe versus Zr sub 57 V sub 36 Fe sub 7

    SciTech Connect

    Sancrotti, M.; Trezzi, G. ); Manini, P. )

    1991-03-01

    We report comparative XPS ({ital h}{nu}=1253.6 eV) core level (Zr 3{ital d}; C 1{ital s}; O 1{ital s}; Fe 2{ital p}; V 2{ital p}) results from two relevant gettering alloys: Zr{sub 2}Fe and Zr{sub 57}V{sub 36}Fe{sub 7}. The samples were studied as-received (after in-air fracturing of bulk ingots) and after different annealing treatments (up to 700 {degree}C) performed in ultrahigh vacuum. With increasing temperature both alloys show a progressive dissolution of Zr oxides, an increase in the metallic character of the surface, the gradual loss of C based adsorbates, and a progressive increase in the surface Zr content and at the expense of the C concentration. At temperatures in the range 300--550 {degree}C a fraction of the C atoms form metallic carbides. OH-based groups are depleted from the surface at low temperatures (200 {degree}C), resulting in a sizable decrease of the near surface O content, while a nearly constant O concentration is found at intermediate and high temperatures. Only minor changes are observed for the near surface concentrations of Fe in Zr{sub 2}Fe and Fe and V in Zr{sub 57}V{sub 36}Fe{sub 7} as a function of temperature. The two alloys show strong differences in the activation kinetics of these changes, with surface metallization being initiated at lower temperatures and proceeding faster in Zr{sub 57}V{sub 36}Fe{sub 7}. Metallic carbides are found to almost completely dissolve in Zr{sub 57}V{sub 36}Fe{sub 7} at 600--700 {degree}C, while they are retained even at high temperatures in Zr{sub 2}Fe. The kinetic differences determined via XPS are consistent with the differences in gettering behavior of Zr{sub 2}Fe and Zr{sub 57}V{sub 36}Fe{sub 7}.

  12. Absorption of magnesium from orally administered magnesium sulfate in man.

    PubMed

    Morris, M E; LeRoy, S; Sutton, S C

    1987-01-01

    The use of magnesium sulfate (Epsom salt) as a cathartic in patients with impaired renal function can lead to severe toxicity due to hypermagnesemia. Although toxicity is uncommon in healthy subjects, little is known concerning the extent of absorption of magnesium after a cathartic dose of magnesium sulfate. The bioavailability of magnesium following a large oral dose of magnesium sulfate in normal volunteers was examined in the present investigation. Baseline 24-hour urinary excretion rates of magnesium and creatinine were determined over 3 consecutive days in 6 healthy men. The oral administration of 13.9 g (56.5 mmoles) magnesium sulfate U.S.P., in 4 equal hourly increments, resulted in the urinary excretion (corrected for baseline excretion rate) of 4.0 +/- 2.9% (mean +/- SD) of the dose of magnesium during the first 24 hours and 6.9 +/- 7.0% of the dose during a 72-hour interval. Magnesium sulfate administration had no effect on the 24-hour urinary excretion rate of creatinine. The baseline excretion rate of magnesium was significantly correlated with that of creatinine (r = 0.875) and inorganic sulfate (r = 0.921). All of the subjects experienced mild or moderate diarrhea. Therefore, magnesium is absorbed to a limited and variable extent in healthy adults following a cathartic dose of magnesium sulfate. PMID:3430654

  13. Calcium carbonate with magnesium overdose

    MedlinePlus

    The combination of calcium carbonate and magnesium is commonly found in antacids. These medicines provide heartburn relief. Calcium carbonate with magnesium overdose occurs when someone takes more than the ...

  14. Aluminum Hydroxide and Magnesium Hydroxide

    MedlinePlus

    Aluminum Hydroxide, Magnesium Hydroxide are antacids used together to relieve heartburn, acid indigestion, and upset stomach. They ... They combine with stomach acid and neutralize it. Aluminum Hydroxide, Magnesium Hydroxide are available without a prescription. ...

  15. Corrosion in Magnesium and a Magnesium Alloy

    NASA Astrophysics Data System (ADS)

    Akavipat, Sanay

    Magnesium and a magnesium alloy (AZ91C) have been ion implanted over a range of ions energies (50 to 150 keV) and doses (1 x 10('16) to 2 x 10('17) ions/cm('2)) to modify the corrosion properties of the metals. The corrosion tests were done by anodic polarization in chloride -free and chloride-containing aqueous solutions of a borated -boric acid with a pH of 9.3. Anodic polarization measurements showed that some implantations could greatly reduce the corrosion current densities at all impressed voltages and also increased slightly the pitting potential, which indicated the onset of the chloride attack. These improvements in corrosion resistance were caused by boron implantations into both types of samples. However, iron implantations were found to improve only the magnesium alloy. To study the corrosion in more detail, Scanning Auger Microprobe Spectrometer (SAM), Scanning Electron Microscope (SEM) with an X-ray Energy Spectrometry (XES) attachment, and Transmission Electron Microscope (TEM) measurements were used to analyze samples before, after, and at various corrosion stages. In both the unimplanted pure magnesium and AZ91C samples, anodic polarization results revealed that there were three active corrosion stages (Stages A, C, and E) and two passivating stages (Stages B and D). Examination of Stages A and B in both types of samples showed that only a mild, generalized corrosion had occurred. In Stage C of the TD samples, a pitting breakdown in the initial oxide film was observed. In Stage C of the AZ91C samples, galvanic and intergranular attack around the Mg(,17)Al(,12) intermetallic islands and along the matrix grain boundaries was observed. Stage D of both samples showed the formation of a thick, passivating oxygen containing, probably Mg(OH)(,2) film. In Stage E, this film was broken down by pits, which formed due to the presence of the chloride ions in both types of samples. Stages A through D of the unimplanted samples were not seen in the boron or iron

  16. Magnesium Research and Technology Development

    SciTech Connect

    Nyberg, Eric A.; Joost, William; Smith, Mark T.

    2009-12-30

    The Magnesium Research and Technical Development (MR&TD) project supports efforts to increase using magnesium in automotive applications, including improving technology, lowering costs and increasing the knowledge needed to enable alloy and manufacturing process optimization. MR&TD supports the U.S. Department of Energy (DOE)/United States Automotive Materials Partnership (USAMP) Magnesium Front End Research and Development (MFERD) project in collaboration with China and Canada. The MR&TD projects also maintains the magnesium bibliographic database at magnesium.pnl.gov.

  17. Mechanisms and regulation of renal magnesium transport.

    PubMed

    Houillier, Pascal

    2014-01-01

    Magnesium's most important role is in the release of chemical energy. Although most magnesium is stored outside of the extracellular fluid compartment, the regulated value is blood magnesium concentration. Cellular magnesium and bone magnesium do not play a major role in the defense of blood magnesium concentration; the major role is played by the kidney, where the renal tubule matches the urinary magnesium excretion and the net entry of magnesium into the extracellular fluid. In the kidney, magnesium is reabsorbed in the proximal tubule, the thick ascending limb of the loop of Henle, and the distal convoluted tubule. Magnesium absorption is mainly paracellular in the proximal tubule and in the thick ascending limb of the loop of Henle, whereas it is transcellular in the distal convoluted tubule. Several hormones and extracellular magnesium itself alter the distal tubular handling of magnesium, but the hormone(s) regulating extracellular magnesium concentration remains unknown. PMID:24512082

  18. Nondestructive spot test method for magnesium and magnesium alloys

    NASA Technical Reports Server (NTRS)

    Wilson, M. L. (Inventor)

    1973-01-01

    A method for spot test identification of magnesium and various magnesium alloys commonly used in aerospace applications is described. The spot test identification involves color codes obtained when several drops of 3 M hydrochloric acid are placed on the surface to be tested. After approximately thirty seconds, two drops of this reacted acid is transferred to each of two depressions in a spot plate for additions of other chemicals with subsequent color changes indicating magnesium or its alloy.

  19. Highly Soluble Alkoxide Magnesium Salts for Rechargeable Magnesium Batteries

    SciTech Connect

    Liao, Chen; Guo, Bingkun; Jiang, Deen; Custelcean, Radu; Mahurin, Shannon Mark; Sun, Xiao-Guang; Dai, Sheng

    2014-01-01

    A unique class of air-stable and non-pyrophoric magnesium electrolytes has been developed based on alkoxide magnesium compounds. The crystals obtained from this class of electrolytes exhibit a unique structure of tri-magnesium cluster, [Mg3Cl3(OR)2(THF)6]+ [(THF)MgCl3] . High reversible capacities and good rate capabilities were obtained in Mg-Mo6S8 batteries using these new electrolytes at both 20 and 50 oC.

  20. Magnesium fluoride recovery method

    DOEpatents

    Gay, Richard L.; McKenzie, Donald E.

    1989-01-01

    A method of obtaining magnesium fluoride substantially free from radioactive uranium from a slag containing the same and having a radioactivity level of at least about 7000 pCi/gm. The slag is ground to a particle size of about 200 microns or less. The ground slag is contacted with an acid under certain prescribed conditions to produce a liquid product and a particulate solid product. The particulate solid product is separated from the liquid and treated at least two more times with acid to produce a solid residue consisting essentially of magnesium fluoride substantially free of uranium and having a residual radioactivity level of less than about 1000 pCi/gm. In accordance with a particularly preferred embodiment of the invention a catalyst and an oxidizing agent are used during the acid treatment and preferably the acid is sulfuric acid having a strength of about 1.0 Normal.

  1. CELLULAR MAGNESIUM HOMEOSTASIS

    PubMed Central

    Romani, Andrea M.P.

    2011-01-01

    Magnesium, the second most abundant cellular cation after potassium, is essential to regulate numerous cellular functions and enzymes, including ion channels, metabolic cycles, and signaling pathways, as attested by more than 1000 entries in the literature. Despite significant recent progress, however, our understanding of how cells regulate Mg2+ homeostasis and transport still remains incomplete. For example, the occurrence of major fluxes of Mg2+ in either direction across the plasma membrane of mammalian cells following metabolic or hormonal stimuli has been extensively documented. Yet, the mechanisms ultimately responsible for magnesium extrusion across the cell membrane have not been cloned. Even less is known about the regulation in cellular organelles. The present review is aimed at providing the reader with a comprehensive and up-to-date understanding of the mechanisms enacted by eukaryotic cells to regulate cellular Mg2+ homeostasis and how these mechanisms are altered under specific pathological conditions. PMID:21640700

  2. Constraining magnesium cycling in marine sediments using magnesium isotopes

    NASA Astrophysics Data System (ADS)

    Higgins, J. A.; Schrag, D. P.

    2010-09-01

    Magnesium concentrations in deep-sea sediment pore-fluids typically decrease down core due to net precipitation of dolomite or clay minerals in the sediments or underlying crust. To better characterize and differentiate these processes, we have measured magnesium isotopes in pore-fluids and sediment samples from Ocean Drilling Program sites (1082, 1086, 1012, 984, 1219, and 925) that span a range of oceanographic settings. At all sites, magnesium concentrations decrease with depth. At sites where diagenetic reactions are dominated by the respiration of organic carbon, pore-fluid δ 26Mg values increase with depth by as much as 2‰. Because carbonates preferentially incorporate 24Mg (low δ 26Mg), the increase in pore-fluid δ 26Mg values at these sites is consistent with the removal of magnesium in Mg-carbonate (dolomite). In contrast, at sites where the respiration of organic carbon is not important and/or weatherable minerals are abundant, pore-fluid δ 26Mg values decrease with depth by up to 2‰. The decline in pore-fluid δ 26Mg at these sites is consistent with a magnesium sink that is isotopically enriched relative to the pore-fluid. The identity of this enriched magnesium sink is likely clay minerals. Using a simple 1D diffusion-advection-reaction model of pore-fluid magnesium, we estimate rates of net magnesium uptake/removal and associated net magnesium isotope fractionation factors for sources and sinks at all sites. Independent estimates of magnesium isotope fractionation during dolomite precipitation from measured δ 26Mg values of dolomite samples from sites 1082 and 1012 are very similar to modeled net fractionation factors at these sites, suggesting that local exchange of magnesium between sediment and pore-fluid at these sites can be neglected. Our results indicate that the magnesium incorporated in dolomite is 2.0-2.7‰ depleted in δ 26Mg relative to the precipitating fluid. Assuming local exchange of magnesium is minor at the rest of the

  3. Mineral of the month: magnesium

    USGS Publications Warehouse

    Kramer, Deborah A.

    2005-01-01

    Magnesium, often confused with last month’s mineral of the month manganese, is valued primarily because of its light weight and high strength-to-weight ratio. Magnesium is the eighth most abundant element and constitutes about 2 percent of the Earth’s crust. It is the third most plentiful element dissolved in seawater, with a concentration averaging 0.13 percent. Magnesium is found in over 60 minerals, and also is recovered from seawater, wells, and lake brines and bitterns.

  4. Low brain magnesium in migraine

    SciTech Connect

    Ramadan, N.M.; Halvorson, H.; Vande-Linde, A.; Levine, S.R.; Helpern, J.A.; Welch, K.M.

    1989-10-01

    Brain magnesium was measured in migraine patients and control subjects using in vivo 31-Phosphorus Nuclear Magnetic Resonance Spectroscopy. pMg and pH were calculated from the chemical shifts between Pi, PCr and ATP signals. Magnesium levels were low during a migraine attack without changes in pH. We hypothesize that low brain magnesium is an important factor in the mechanism of the migraine attack.

  5. Magnesium metabolism: a brief review.

    PubMed Central

    Paymaster, N. J.

    1976-01-01

    The important role played by the magnesium ion in the body is not generally recognized. The action of numerous enzyme systems critical to cellular metabolism is regulated by it and it contributes importantly to macromolecular structure. Magnesium defiency occurs more often than is generally suspected; magnesium excess, though uncommon, is of special interest to the anaesthetist because it produces a curare-like effect on neuromuscular transmission. It is hoped that this brief review of magnesium metabolism will draw attention to its importance and relevance in everyday practice. PMID:942168

  6. Magnesium Hall Thruster

    NASA Technical Reports Server (NTRS)

    Szabo, James J.

    2015-01-01

    This Phase II project is developing a magnesium (Mg) Hall effect thruster system that would open the door for in situ resource utilization (ISRU)-based solar system exploration. Magnesium is light and easy to ionize. For a Mars- Earth transfer, the propellant mass savings with respect to a xenon Hall effect thruster (HET) system are enormous. Magnesium also can be combusted in a rocket with carbon dioxide (CO2) or water (H2O), enabling a multimode propulsion system with propellant sharing and ISRU. In the near term, CO2 and H2O would be collected in situ on Mars or the moon. In the far term, Mg itself would be collected from Martian and lunar regolith. In Phase I, an integrated, medium-power (1- to 3-kW) Mg HET system was developed and tested. Controlled, steady operation at constant voltage and power was demonstrated. Preliminary measurements indicate a specific impulse (Isp) greater than 4,000 s was achieved at a discharge potential of 400 V. The feasibility of delivering fluidized Mg powder to a medium- or high-power thruster also was demonstrated. Phase II of the project evaluated the performance of an integrated, highpower Mg Hall thruster system in a relevant space environment. Researchers improved the medium power thruster system and characterized it in detail. Researchers also designed and built a high-power (8- to 20-kW) Mg HET. A fluidized powder feed system supporting the high-power thruster was built and delivered to Busek Company, Inc.

  7. Magnesium in Prevention and Therapy

    PubMed Central

    Gröber, Uwe; Schmidt, Joachim; Kisters, Klaus

    2015-01-01

    Magnesium is the fourth most abundant mineral in the body. It has been recognized as a cofactor for more than 300 enzymatic reactions, where it is crucial for adenosine triphosphate (ATP) metabolism. Magnesium is required for DNA and RNA synthesis, reproduction, and protein synthesis. Moreover, magnesium is essential for the regulation of muscular contraction, blood pressure, insulin metabolism, cardiac excitability, vasomotor tone, nerve transmission and neuromuscular conduction. Imbalances in magnesium status—primarily hypomagnesemia as it is seen more common than hypermagnesemia—might result in unwanted neuromuscular, cardiac or nervous disorders. Based on magnesium’s many functions within the human body, it plays an important role in prevention and treatment of many diseases. Low levels of magnesium have been associated with a number of chronic diseases, such as Alzheimer’s disease, insulin resistance and type-2 diabetes mellitus, hypertension, cardiovascular disease (e.g., stroke), migraine headaches, and attention deficit hyperactivity disorder (ADHD). PMID:26404370

  8. Magnesium substitution in brushite cements.

    PubMed

    Alkhraisat, Mohammad Hamdan; Cabrejos-Azama, Jatsue; Rodríguez, Carmen Rueda; Jerez, Luis Blanco; Cabarcos, Enrique López

    2013-01-01

    The use of magnesium-doped ceramics has been described to modify brushite cements and improve their biological behavior. However, few studies have analyzed the efficiency of this approach to induce magnesium substitution in brushite crystals. Mg-doped ceramics composed of Mg-substituted β-TCP, stanfieldite and/or farringtonite were reacted with primary monocalcium phosphate (MCP) in the presence of water. The cement setting reaction has resulted in the formation of brushite and newberyite within the cement matrix. Interestingly, the combination of SAED and EDX analyses of single crystal has indicated the occurrence of magnesium substitution within brushite crystals. Moreover, the effect of magnesium ions on the structure, and mechanical and setting properties of the new cements was characterized as well as the release of Ca(2+) and Mg(2+) ions. Further research would enhance the efficiency of the system to incorporate larger amounts of magnesium ions within brushite crystals. PMID:25428098

  9. Synthesis of magnesium diboride by magnesium vapor infiltration process (MVIP)

    DOEpatents

    Serquis, Adriana C.; Zhu, Yuntian T.; Mueller, Frederick M.; Peterson, Dean E.; Liao, Xiao Zhou

    2003-01-01

    A process of preparing superconducting magnesium diboride powder by heating an admixture of solid magnesium and amorphous boron powder or pellet under an inert atmosphere in a Mg:B ratio of greater than about 0.6:1 at temperatures and for time sufficient to form said superconducting magnesium diboride. The process can further include exposure to residual oxygen at high synthesis temperatures followed by slow cooling. In the cooling process oxygen atoms dissolved into MgB.sub.2 segregated to form nanometer-sized coherent Mg(B,O) precipitates in the MgB.sub.2 matrix, which can act as flux pinning centers.

  10. Ultrasound-assisted synthesis of magnesium hydroxide nanoparticles from magnesium.

    PubMed

    Baidukova, Olga; Skorb, Ekaterina V

    2016-07-01

    Acoustic cavitation in water provides special kinetic and thermodynamic conditions for chemical synthesis and nanostructuring of solids. Using cavitation phenomenon, we obtained magnesium hydroxide from pure magnesium. This approach allows magnesium hydroxide to be synthesized without the requirement of any additives and non-aqueous solvents. Variation of sonochemical parameters enabled a total transformation of the metal to nanosized brucite with distinct morphology. Special attention is given to the obtaining of platelet-shaped, nanometric and de-agglomerated powders. The products of the synthesis were characterized by transmission electron microscopy (TEM), electron diffraction (ED), scanning electron microscopy (SEM) and X-ray diffraction (XRD). PMID:26964968

  11. 21 CFR 184.1443 - Magnesium sulfate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Magnesium sulfate. 184.1443 Section 184.1443 Food... Specific Substances Affirmed as GRAS § 184.1443 Magnesium sulfate. (a) Magnesium sulfate (MgSO4·7H2O, CAS... magnesium oxide, hydroxide, or carbonate with sulfuric acid and evaporating the solution to...

  12. 21 CFR 184.1426 - Magnesium chloride.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Magnesium chloride. 184.1426 Section 184.1426 Food... Specific Substances Affirmed as GRAS § 184.1426 Magnesium chloride. (a) Magnesium chloride (MgC12·6H2O, CAS... mineral bischofite. It is prepared by dissolving magnesium oxide, hydroxide, or carbonate in...

  13. 21 CFR 184.1431 - Magnesium oxide.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Magnesium oxide. 184.1431 Section 184.1431 Food and... Substances Affirmed as GRAS § 184.1431 Magnesium oxide. (a) Magnesium oxide (MgO, CAS Reg. No. 1309-48-4... powder (light) or a relatively dense white powder (heavy) by heating magnesium hydroxide or...

  14. 21 CFR 184.1428 - Magnesium hydroxide.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Magnesium hydroxide. 184.1428 Section 184.1428 Food... Specific Substances Affirmed as GRAS § 184.1428 Magnesium hydroxide. (a) Magnesium hydroxide (Mg(OH)2, CAS... a white precipitate by the addition of sodium hydroxide to a water soluble magnesium salt or...

  15. Mineral resource of the month: magnesium

    USGS Publications Warehouse

    Kramer, Deborah A.

    2012-01-01

    Magnesium is the eighthmost abundant element in Earth’s crust, and the second-most abundant metal ion in seawater. Although magnesium is found in more than 60 minerals, only brucite, dolomite, magnesite and carnallite are commercially important for their magnesium content. Magnesium and its compounds also are recovered from seawater, brines found in lakes and wells, and bitterns (salts).

  16. 21 CFR 184.1428 - Magnesium hydroxide.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... salt or by hydration of reactive grades of magnesium oxide. (b) The ingredient meets the specifications... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Magnesium hydroxide. 184.1428 Section 184.1428... Listing of Specific Substances Affirmed as GRAS § 184.1428 Magnesium hydroxide. (a) Magnesium...

  17. 21 CFR 184.1431 - Magnesium oxide.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Magnesium oxide. 184.1431 Section 184.1431 Food... Specific Substances Affirmed as GRAS § 184.1431 Magnesium oxide. (a) Magnesium oxide (MgO, CAS Reg. No... light magnesium oxide. Heating the salts under more rigorous conditions (1200 °C for 12 hours)...

  18. 21 CFR 184.1443 - Magnesium sulfate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... magnesium oxide, hydroxide, or carbonate with sulfuric acid and evaporating the solution to crystallization... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Magnesium sulfate. 184.1443 Section 184.1443 Food... Specific Substances Affirmed as GRAS § 184.1443 Magnesium sulfate. (a) Magnesium sulfate (MgSO4·7H2O,...

  19. Role of Cellular Magnesium in Human Diseases

    PubMed Central

    Long, Samantha; Romani, Andrea MP

    2015-01-01

    Magnesium is required for many of the major organs to function and plays a crucial role in human and mammalian physiology. Magnesium is essential for the structure of bones and teeth, acts as a cofactor for more than 300 enzymes in the body, including binding to ATP for kinase reactions, and affects permeability of excitable membranes and neuromuscular transmission. Despite these essential roles, much is still unknown about magnesium physiology and homeostasis. Currently, nutritionists believe that the general population intakes insufficient magnesium daily through the diet. The effects of magnesium deficiency are, for the most part undetected, and simple, widespread assessments of magnesium intake remain unavailable for humans. Many of the patients admitted to hospitals or medical care facilities are unaware of their low magnesium levels. Moreover, because magnesium is predominantly an intracellular cation (>99%), serum magnesium levels remain a poor predictor of tissue magnesium content and availability. This review will discuss the effects of magnesium deficiency in various pathologies affecting the human population. The underlying causes for magnesium depletion in major physiological systems will be examined along with the involved signaling pathways and the main roles of magnesium homeostasis. Where possible (e.g. alcoholism), the implications of administering supplemental magnesium will be discussed. Ultimately, this review will advocate for the necessity of identifying easy and reproducible methods to assess serum and cellular magnesium levels and to identify magnesium deficiency in order to alleviate related pathological conditions. PMID:25839058

  20. Magnesium and hearing.

    PubMed

    Cevette, Michael J; Vormann, Jürgen; Franz, Kay

    2003-01-01

    The last several decades have revealed clinical and experimental data regarding the importance of magnesium (Mg) in hearing. Increased susceptibility to noise damage, ototoxicity, and auditory hyperexcitability are linked to states of Mg deficiency. Evidence for these processes has come slowly and direct effects have remained elusive because plasma Mg levels do not always correlate with its deficiency. Despite the major progress in the understanding of cochlear mechanical and auditory nerve function, the neurochemical and pharmacologic role of Mg is not clear. The putative mechanism suggests that Mg deficiency may contribute to a metabolic cellular cascade of events. Mg deficiency leads to an increased permeability of the calcium channel in the hair cells with a consequent over influx of calcium, an increased release of glutamate via exocytosis, and over stimulation of NMDA receptors on the auditory nerve. This paper provides a current overview of relevant Mg metabolism and deficiency and its influence on hearing. PMID:12940704

  1. Magnesium: Engineering the Surface

    NASA Astrophysics Data System (ADS)

    Chen, X. B.; Yang, H. Y.; Abbott, T. B.; Easton, M. A.; Birbilis, N.

    2012-06-01

    Magnesium (Mg) and its alloys provide numerous benefits as lightweight materials; however, industrial deployment of Mg in most instances requires anticorrosion coatings. Engineering the Mg surface is an area that has been undergoing intense research recently. Surface engineering commences with the "pretreatment" step, which can be used to modify the surface composition and morphology, resulting in surface enrichment or depletion of alloying elements. Following this, electrochemical plating (including electro- and electroless plating) and conversion coatings have emerged as common means of coating Mg. In this study, we present the key aspects relating to the science and technology associated with pretreatment, electrochemical plating, and conversion coatings. This is followed by experimental examples of engineered surfaces of industrial relevance.

  2. Magnesium status and digoxin toxicity.

    PubMed Central

    Young, I S; Goh, E M; McKillop, U H; Stanford, C F; Nicholls, D P; Trimble, E R

    1991-01-01

    1. Eighty-one hospital patients receiving digoxin were separated into groups with and without digoxin toxicity using clinical criteria. Serum digoxin, sodium, potassium, calcium, creatinine, magnesium and monocyte magnesium concentrations were compared. 2. Subjects with digoxin toxicity had impaired colour vision (P less than 0.0001, Farnsworth-Munsell 100 hue test) and increased digoxin levels (1.89 (1.56-2.21) vs 1.34 (1.20-1.47) nmol l-1, P less than 0.01) (mean (95% confidence limits], though there was considerable overlap between two groups. 3. Subjects with digoxin toxicity had lower levels of serum magnesium (0.80 (0.76-0.84) vs 0.88 (0.85-0.91) mmol l-1, P less than 0.01) and monocyte magnesium (6.40 (5.65-7.16) vs 8.76 (7.81-9.71) mg g-1 DNA, P less than 0.01), but there were no significant differences in other biochemical parameters. A greater proportion of toxic subjects were receiving concomitant diuretic therapy (20/21 vs 37/60, P less than 0.05). 4. Magnesium deficiency was the most frequently identified significant electrolyte disturbance in relation to digoxin toxicity. In the presence of magnesium deficiency digoxin toxicity developed at relatively low serum digoxin concentrations. PMID:1768564

  3. Magnesium and fetal growth

    SciTech Connect

    Weaver, K.

    1988-01-01

    Fetal growth retardation and premature labor are major problems in perinatal medicine today and account for a great deal of the observed fetal morbidity. While the neonatal death rate has steadily declined over the past decade, there has been a lack of concommitant decrease in these two leading problems. Magnesium (Mg/sup ++/) plays a major role in both of these areas of concern. The fact that it is used as a treatment for premature labor has led investigators to look at low Mg/sup ++/ as a possible cause of this poorly understood phenomenon. The second major cause of small for gestational age infants is intrauterine growth retardation, a condition which may be of either fetal or maternal origin. In either case, Mg/sup ++/ may be implicated since it exerts a strong influence on the underlying pathophysiology of placental failure and maternal hypertension. Both of these conditions are mediated by vascular and platelet hyperactivity as well as by and increase in the ration of thromboxane to prostacyclin. Studies in both the human and animal species are beginning to show how Mg/sup ++/ interacts in these conditions to produce such a damaging fetal outcome. The recent use of Doppler velocimetry of the developing fetus has shown reduced fetal vascular and maternal uterine vascular compliance as early as 14 weeks of gestation in those who would be so affected.

  4. Magnesium silicide intermetallic alloys

    NASA Astrophysics Data System (ADS)

    Li, Gh.; Gill, H. S.; Varin, R. A.

    1993-11-01

    Methods of induction melting an ultra-low-density magnesium silicide (Mg2Si) intermetallic and its alloys and the resulting microstructure and microhardness were studied. The highest quality ingots of Mg2Si alloys were obtained by triple melting in a graphite crucible coated with boron nitride to eliminate reactivity, under overpressure of high-purity argon (1.3 X 105 Pa), at a temperature close to but not exceeding 1105 °C ± 5 °C to avoid excessive evaporation of Mg. After establishing the proper induction-melting conditions, the Mg-Si binary alloys and several Mg2Si alloys macroalloyed with 1 at. pct of Al, Ni, Co, Cu, Ag, Zn, Mn, Cr, and Fe were induction melted and, after solidification, investigated by optical microscopy and quantitative X-ray energy dispersive spectroscopy (EDS). Both the Mg-rich and Si-rich eutectic in the binary alloys exhibited a small but systematic increase in the Si content as the overall composition of the binary alloy moved closer toward the Mg2Si line compound. The Vickers microhardness (VHN) of the as-solidified Mg-rich and Si-rich eutectics in the Mg-Si binary alloys decreased with increasing Mg (decreasing Si) content in the eutectic. This behavior persisted even after annealing for 75 hours at 0.89 pct of the respective eutectic temperature. The Mg-rich eutectic in the Mg2Si + Al, Ni, Co, Cu, Ag, and Zn alloys contained sections exhibiting a different optical contrast and chemical composition than the rest of the eutectic. Some particles dispersed in the Mg2Si matrix were found in the Mg2Si + Cr, Mn, and Fe alloys. The EDS results are presented and discussed and compared with the VHN data.

  5. Magnesium/Calcium Competition at Excitable Membranes.

    ERIC Educational Resources Information Center

    Belzer, Bill; Fry, Panni

    1998-01-01

    Considers some consequences of altering intracellular calcium supply by magnesium concentration changes. Focuses on using this procedure as an exercise with allied health students as they witness therapeutic uses of magnesium and other calcium entry inhibitors. (DDR)

  6. Lightweight magnesium-lithium alloys show promise

    NASA Technical Reports Server (NTRS)

    Adams, W. T.; Cataldo, C. E.

    1964-01-01

    Evaluation tests show that magnesium-lithium alloys are lighter and more ductile than other magnesium alloys. They are being used for packaging, housings, containers, where light weight is more important than strength.

  7. Solid-state rechargeable magnesium battery

    DOEpatents

    Shao, Yuyan; Liu, Jun; Liu, Tianbiao; Li, Guosheng

    2016-09-06

    Embodiments of a solid-state electrolyte comprising magnesium borohydride, polyethylene oxide, and optionally a Group IIA or transition metal oxide are disclosed. The solid-state electrolyte may be a thin film comprising a dispersion of magnesium borohydride and magnesium oxide nanoparticles in polyethylene oxide. Rechargeable magnesium batteries including the disclosed solid-state electrolyte may have a coulombic efficiency .gtoreq.95% and exhibit cycling stability for at least 50 cycles.

  8. 21 CFR 184.1425 - Magnesium carbonate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Magnesium carbonate. 184.1425 Section 184.1425 Food... Specific Substances Affirmed as GRAS § 184.1425 Magnesium carbonate. (a) Magnesium carbonate (molecular formula approximately (MgCO3)4·Mg(OH)2·5H2O, CAS Reg. No. 39409-82-0) is also known as magnesium...

  9. 21 CFR 184.1440 - Magnesium stearate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Magnesium stearate. 184.1440 Section 184.1440 Food... Specific Substances Affirmed as GRAS § 184.1440 Magnesium stearate. (a) Magnesium stearate (Mg(C17H34COO)2, CAS Reg. No. 557-04-0) is the magnesium salt of stearic acid. It is produced as a white precipitate...

  10. 21 CFR 184.1440 - Magnesium stearate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Magnesium stearate. 184.1440 Section 184.1440 Food... GRAS § 184.1440 Magnesium stearate. (a) Magnesium stearate (Mg(C17H34COO)2, CAS Reg. No. 557-04-0) is the magnesium salt of stearic acid. It is produced as a white precipitate by the addition of...

  11. 21 CFR 184.1440 - Magnesium stearate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Magnesium stearate. 184.1440 Section 184.1440 Food... Specific Substances Affirmed as GRAS § 184.1440 Magnesium stearate. (a) Magnesium stearate (Mg(C17H34COO)2, CAS Reg. No. 557-04-0) is the magnesium salt of stearic acid. It is produced as a white precipitate...

  12. 21 CFR 184.1425 - Magnesium carbonate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Magnesium carbonate. 184.1425 Section 184.1425... GRAS § 184.1425 Magnesium carbonate. (a) Magnesium carbonate (molecular formula approximately (MgCO3)4·Mg(OH)2·5H2O, CAS Reg. No. 39409-82-0) is also known as magnesium carbonate hydroxide. It is a...

  13. 21 CFR 184.1440 - Magnesium stearate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Magnesium stearate. 184.1440 Section 184.1440 Food... Specific Substances Affirmed as GRAS § 184.1440 Magnesium stearate. (a) Magnesium stearate (Mg(C17H34COO)2, CAS Reg. No. 557-04-0) is the magnesium salt of stearic acid. It is produced as a white precipitate...

  14. 21 CFR 184.1440 - Magnesium stearate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Magnesium stearate. 184.1440 Section 184.1440 Food... Specific Substances Affirmed as GRAS § 184.1440 Magnesium stearate. (a) Magnesium stearate (Mg(C17H34COO)2, CAS Reg. No. 557-04-0) is the magnesium salt of stearic acid. It is produced as a white precipitate...

  15. Dislocation Creep in Magnesium Calcite

    NASA Astrophysics Data System (ADS)

    Xu, L.; Xiao, X.; Evans, B. J.

    2003-12-01

    To investigate the effect of dissolved Mg on plastic deformation of calcite, we performed triaxial deformation experiments on synthetic calcite with varying amount of Mg content. Mixtures of powders of calcite and dolomite were isostatically hot pressed (HIP) at 850° C and 300 MPa confining pressure for different intervals (2 to 20hrs) resulting in homogeneous aggregates of high-magnesium calcite; Mg content varied from 0.07 to 0.17 mol%. Creep tests were performed at differential stresses from 20 to 160 MPa at 700 to 800° C. Grain sizes before and after deformation were determined from the images obtained from scanning electron microscope (SEM) and optical microscope. Grain sizes are in the range of 5 to 20 microns depending on the HIP time, and decrease with increasing magnesium content. Both BSE images and chemical analysis suggest that all dolomite are dissolved and the Mg distribution is homogeneous through the sample, after 2 hrs HIP. At stresses below 40 MPa, the samples deformed in diffusion region (Coble creep), as described previously by Herwegh. The strength decreases with increasing magnesium content, owing to the difference of grain size. At stresses above 80 MPa, the stress exponent is greater than 3, indicating an increased contribution of dislocation creep. The transition between diffusion to dislocation creep occurs at higher stresses for the samples with higher magnesium content and smaller grain size. Preliminary data suggests a slight increase in strength with increasing magnesium content, but more tests are needed to verify this effect. In a few samples, some strain weakening may have been evident. The activation energy in the transition region (at 80 MPa) is ˜200 KJ/mol with no dependence on magnesium content, agreeing with previous measurements of diffusion creep in natural and synthetic marbles.

  16. 21 CFR 582.1428 - Magnesium hydroxide.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Magnesium hydroxide. 582.1428 Section 582.1428 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1428 Magnesium hydroxide. (a) Product. Magnesium hydroxide. (b) Conditions of use....

  17. 21 CFR 582.5431 - Magnesium oxide.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Magnesium oxide. 582.5431 Section 582.5431 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Supplements 1 § 582.5431 Magnesium oxide. (a) Product. Magnesium oxide. (b) Conditions of use. This...

  18. 21 CFR 582.5443 - Magnesium sulfate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Magnesium sulfate. 582.5443 Section 582.5443 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Supplements 1 § 582.5443 Magnesium sulfate. (a) Product. Magnesium sulfate. (b) Conditions of use....

  19. 21 CFR 201.71 - Magnesium labeling.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 4 2010-04-01 2010-04-01 false Magnesium labeling. 201.71 Section 201.71 Food and... LABELING Labeling Requirements for Over-the-Counter Drugs § 201.71 Magnesium labeling. (a) The labeling of over-the-counter (OTC) drug products intended for oral ingestion shall contain the magnesium...

  20. 21 CFR 582.1431 - Magnesium oxide.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Magnesium oxide. 582.1431 Section 582.1431 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1431 Magnesium oxide. (a) Product. Magnesium oxide. (b) Conditions of use. This substance...

  1. 21 CFR 582.1428 - Magnesium hydroxide.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Magnesium hydroxide. 582.1428 Section 582.1428 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1428 Magnesium hydroxide. (a) Product. Magnesium hydroxide. (b) Conditions of use....

  2. 21 CFR 182.2437 - Magnesium silicate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Magnesium silicate. 182.2437 Section 182.2437 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR... Magnesium silicate. (a) Product. Magnesium silicate. (b) Tolerance. 2 percent. (c) Limitations,...

  3. 21 CFR 582.1425 - Magnesium carbonate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Magnesium carbonate. 582.1425 Section 582.1425 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1425 Magnesium carbonate. (a) Product. Magnesium carbonate. (b) Conditions of use....

  4. 76 FR 69284 - Pure Magnesium From China

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-08

    ... COMMISSION Pure Magnesium From China Determination On the basis of the record \\1\\ developed in the subject... order on pure magnesium from China would be likely to lead to continuation or recurrence of material... USITC Publication 4274 (October 2011), entitled Pure Magnesium from China: Investigation No....

  5. 21 CFR 582.5434 - Magnesium phosphate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Magnesium phosphate. 582.5434 Section 582.5434 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Supplements 1 § 582.5434 Magnesium phosphate. (a) Product. Magnesium phosphate (di- and tribasic)....

  6. Synthesis of superconducting magnesium diboride objects

    DOEpatents

    Finnemore, Douglas K.; Canfield, Paul C.; Bud'ko, Sergey L.; Ostenson, Jerome E.; Petrovic, Cedomir; Cunningham, Charles E.; Lapertot, Gerard

    2003-08-15

    A process to produce magnesium diboride objects from boron objects with a similar form is presented. Boron objects are reacted with magnesium vapor at a predetermined time and temperature to form magnesium diboride objects having a morphology similar to the boron object's original morphology.

  7. 21 CFR 582.2437 - Magnesium silicate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Magnesium silicate. 582.2437 Section 582.2437 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Magnesium silicate. (a) Product. Magnesium silicate. (b) Tolerance. 2 percent. (c) Limitations,...

  8. Synthesis Of Superconducting Magnesium Diboride Objects.

    DOEpatents

    Finnemore, Douglas K.; Canfield, Paul C.; Bud'ko, Sergey L.; Ostenson, Jerome E.; Petrovic, Cedomir; Cunningham, Charles E.; Lapertot, Gerard

    2003-07-08

    A process to produce magnesium diboride objects from boron objects with a similar form is presented. Boron objects are reacted with magnesium vapor at a predetermined time and temperature to form magnesium diboride objects having a morphology similar to the boron object's original morphology.

  9. 21 CFR 582.5431 - Magnesium oxide.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Magnesium oxide. 582.5431 Section 582.5431 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Supplements 1 § 582.5431 Magnesium oxide. (a) Product. Magnesium oxide. (b) Conditions of use. This...

  10. 21 CFR 582.1431 - Magnesium oxide.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Magnesium oxide. 582.1431 Section 582.1431 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1431 Magnesium oxide. (a) Product. Magnesium oxide. (b) Conditions of use. This substance...

  11. 21 CFR 184.1431 - Magnesium oxide.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Magnesium oxide. 184.1431 Section 184.1431 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) DIRECT FOOD SUBSTANCES AFFIRMED AS GENERALLY RECOGNIZED AS SAFE Listing of Specific Substances Affirmed as GRAS § 184.1431 Magnesium oxide. (a) Magnesium...

  12. 21 CFR 582.1431 - Magnesium oxide.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Magnesium oxide. 582.1431 Section 582.1431 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1431 Magnesium oxide. (a) Product. Magnesium oxide. (b) Conditions of use. This substance...

  13. 21 CFR 582.1431 - Magnesium oxide.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Magnesium oxide. 582.1431 Section 582.1431 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1431 Magnesium oxide. (a) Product. Magnesium oxide. (b) Conditions of use. This substance...

  14. 21 CFR 582.5431 - Magnesium oxide.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Magnesium oxide. 582.5431 Section 582.5431 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Supplements 1 § 582.5431 Magnesium oxide. (a) Product. Magnesium oxide. (b) Conditions of use. This...

  15. 21 CFR 582.5431 - Magnesium oxide.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Magnesium oxide. 582.5431 Section 582.5431 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Supplements 1 § 582.5431 Magnesium oxide. (a) Product. Magnesium oxide. (b) Conditions of use. This...

  16. 21 CFR 582.5434 - Magnesium phosphate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Magnesium phosphate. 582.5434 Section 582.5434 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Supplements 1 § 582.5434 Magnesium phosphate. (a) Product. Magnesium phosphate (di- and tribasic)....

  17. Magnesium, Inflammation, and Obesity in Chronic Disease

    Technology Transfer Automated Retrieval System (TEKTRAN)

    About 60% of U.S. adults do not consume the Estimated Average Intake for magnesium, but widespread pathological conditions attributed to magnesium deficiency have not been reported. However, low magnesium status has been associated with numerous pathological conditions characterized as having a chr...

  18. 21 CFR 582.2437 - Magnesium silicate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Magnesium silicate. 582.2437 Section 582.2437 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Magnesium silicate. (a) Product. Magnesium silicate. (b) Tolerance. 2 percent. (c) Limitations,...

  19. 21 CFR 582.1428 - Magnesium hydroxide.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Magnesium hydroxide. 582.1428 Section 582.1428 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1428 Magnesium hydroxide. (a) Product. Magnesium hydroxide. (b) Conditions of use....

  20. 21 CFR 582.1425 - Magnesium carbonate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Magnesium carbonate. 582.1425 Section 582.1425 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1425 Magnesium carbonate. (a) Product. Magnesium carbonate. (b) Conditions of use....

  1. 21 CFR 582.2437 - Magnesium silicate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Magnesium silicate. 582.2437 Section 582.2437 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Magnesium silicate. (a) Product. Magnesium silicate. (b) Tolerance. 2 percent. (c) Limitations,...

  2. 21 CFR 582.1425 - Magnesium carbonate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Magnesium carbonate. 582.1425 Section 582.1425 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1425 Magnesium carbonate. (a) Product. Magnesium carbonate. (b) Conditions of use....

  3. 21 CFR 582.5443 - Magnesium sulfate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Magnesium sulfate. 582.5443 Section 582.5443 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Supplements 1 § 582.5443 Magnesium sulfate. (a) Product. Magnesium sulfate. (b) Conditions of use....

  4. 21 CFR 582.1428 - Magnesium hydroxide.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Magnesium hydroxide. 582.1428 Section 582.1428 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1428 Magnesium hydroxide. (a) Product. Magnesium hydroxide. (b) Conditions of use....

  5. 21 CFR 182.2437 - Magnesium silicate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Magnesium silicate. 182.2437 Section 182.2437 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR... Magnesium silicate. (a) Product. Magnesium silicate. (b) Tolerance. 2 percent. (c) Limitations,...

  6. 21 CFR 182.2437 - Magnesium silicate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Magnesium silicate. 182.2437 Section 182.2437 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR... Magnesium silicate. (a) Product. Magnesium silicate. (b) Tolerance. 2 percent. (c) Limitations,...

  7. 21 CFR 582.2437 - Magnesium silicate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Magnesium silicate. 582.2437 Section 582.2437 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Magnesium silicate. (a) Product. Magnesium silicate. (b) Tolerance. 2 percent. (c) Limitations,...

  8. 21 CFR 582.1425 - Magnesium carbonate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Magnesium carbonate. 582.1425 Section 582.1425 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1425 Magnesium carbonate. (a) Product. Magnesium carbonate. (b) Conditions of use....

  9. 21 CFR 582.1428 - Magnesium hydroxide.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Magnesium hydroxide. 582.1428 Section 582.1428 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1428 Magnesium hydroxide. (a) Product. Magnesium hydroxide. (b) Conditions of use....

  10. 21 CFR 582.5443 - Magnesium sulfate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Magnesium sulfate. 582.5443 Section 582.5443 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Supplements 1 § 582.5443 Magnesium sulfate. (a) Product. Magnesium sulfate. (b) Conditions of use....

  11. 21 CFR 182.2437 - Magnesium silicate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Magnesium silicate. 182.2437 Section 182.2437 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR... Magnesium silicate. (a) Product. Magnesium silicate. (b) Tolerance. 2 percent. (c) Limitations,...

  12. 21 CFR 582.5443 - Magnesium sulfate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Magnesium sulfate. 582.5443 Section 582.5443 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Supplements 1 § 582.5443 Magnesium sulfate. (a) Product. Magnesium sulfate. (b) Conditions of use....

  13. 21 CFR 582.1425 - Magnesium carbonate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Magnesium carbonate. 582.1425 Section 582.1425 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1425 Magnesium carbonate. (a) Product. Magnesium carbonate. (b) Conditions of use....

  14. 21 CFR 582.2437 - Magnesium silicate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Magnesium silicate. 582.2437 Section 582.2437 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Magnesium silicate. (a) Product. Magnesium silicate. (b) Tolerance. 2 percent. (c) Limitations,...

  15. 21 CFR 582.5443 - Magnesium sulfate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Magnesium sulfate. 582.5443 Section 582.5443 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Supplements 1 § 582.5443 Magnesium sulfate. (a) Product. Magnesium sulfate. (b) Conditions of use....

  16. 21 CFR 582.5434 - Magnesium phosphate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Magnesium phosphate. 582.5434 Section 582.5434 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Supplements 1 § 582.5434 Magnesium phosphate. (a) Product. Magnesium phosphate (di- and tribasic)....

  17. 21 CFR 582.5434 - Magnesium phosphate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Magnesium phosphate. 582.5434 Section 582.5434 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Supplements 1 § 582.5434 Magnesium phosphate. (a) Product. Magnesium phosphate (di- and tribasic)....

  18. 21 CFR 582.5434 - Magnesium phosphate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Magnesium phosphate. 582.5434 Section 582.5434 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Supplements 1 § 582.5434 Magnesium phosphate. (a) Product. Magnesium phosphate (di- and tribasic)....

  19. Magnesium Diboride Current Leads

    NASA Technical Reports Server (NTRS)

    Panek, John

    2010-01-01

    A recently discovered superconductor, magnesium diboride (MgB2), can be used to fabricate conducting leads used in cryogenic applications. Dis covered to be superconducting in 2001, MgB2 has the advantage of remaining superconducting at higher temperatures than the previously used material, NbTi. The purpose of these leads is to provide 2 A of electricity to motors located in a 1.3 K environment. The providing environment is a relatively warm 17 K. Requirements for these leads are to survive temperature fluctuations in the 5 K and 11 K heat sinks, and not conduct excessive heat into the 1.3 K environment. Test data showed that each lead in the assembly could conduct 5 A at 4 K, which, when scaled to 17 K, still provided more than the required 2 A. The lead assembly consists of 12 steelclad MgB2 wires, a tensioned Kevlar support, a thermal heat sink interface at 4 K, and base plates. The wires are soldered to heavy copper leads at the 17 K end, and to thin copper-clad NbTi leads at the 1.3 K end. The leads were designed, fabricated, and tested at the Forschungszentrum Karlsruhe - Institut foer Technische Physik before inclusion in Goddard's XRS (X-Ray Spectrometer) instrument onboard the Astro-E2 spacecraft. A key factor is that MgB2 remains superconducting up to 30 K, which means that it does not introduce joule heating as a resistive wire would. Because the required temperature ranges are 1.3-17 K, this provides a large margin of safety. Previous designs lost superconductivity at around 8 K. The disadvantage to MgB2 is that it is a brittle ceramic, and making thin wires from it is challenging. The solution was to encase the leads in thin steel tubes for strength. Previous designs were so brittle as to risk instrument survival. MgB2 leads can be used in any cryogenic application where small currents need to be conducted at below 30 K. Because previous designs would superconduct only at up to 8 K, this new design would be ideal for the 8-30 K range.

  20. [The significance of magnesium in orthopedics. V. Magnesium in osteoporosis].

    PubMed

    Ditmar, R; Steidl, L

    1989-04-01

    The authors submit an investigation of 60 patients with senile, post-menopausal and drug-induced osteoporosis. Using the method of absorption spectrophotometry, they found a reduced level of Mg in red blood cells in 63.6% of senile, 66.7% postmenopausal and only in 22.2% drug-induced osteoporoses. Also the mean level of red cell magnesium was significantly lower in the group of senile (1.94 mmol) and postmenopausal (1.85 mmol) osteoporosis as compared with drug-induced osteoporosis (2.25 mmol). The authors revealed moreover that the level of red cell magnesium in the former two groups declines in proportion to the severity of osteoporosis and correlates thus with the clinical and X-ray finding. For treatment of osteoporisis the authors used magnesium lactate alone (in 37 patients) and combined with sodium fluoride (in 23 patients). In the majority of patients they had very favourable results. Based on laboratory and therapeutic results, consistent with data in the experimental literature, the authors assume that magnesium as a catalyst of bone metabolism and as one of the most important factors controlling the formation of bone matrix and its mineralization plays a significant role in the aetiopathogenesis of senile and postmenopausal osteoporosis. The authors assume that Mg deficiency which is increasing in recent years in soil as well as in foodstuffs and water may be the main cause of the increasing number of patients with osteoporosis in civilized countries. Magnesium should have its firm place not only in therapy but also in prevention of the majority of osteoporosis. PMID:2750424

  1. Major Minerals - Calcium, Magnesium, Phosphorus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Calcium, magnesium and phosphorus are essential elements critically important for the function of the musculoskeletal system, including the formation and transduction of energy and the maintenance of healthy bone. The major calcium concern for physically active healthy middle-aged adults is to consu...

  2. A SEARCH FOR MAGNESIUM IN EUROPA'S ATMOSPHERE

    SciTech Connect

    Hoerst, S. M.; Brown, M. E.

    2013-02-20

    Europa's tenuous atmosphere results from sputtering of the surface. The trace element composition of its atmosphere is therefore related to the composition of Europa's surface. Magnesium salts are often invoked to explain Galileo Near Infrared Mapping Spectrometer spectra of Europa's surface, thus magnesium may be present in Europa's atmosphere. We have searched for magnesium emission in the Hubble Space Telescope Faint Object Spectrograph archival spectra of Europa's atmosphere. Magnesium was not detected and we calculate an upper limit on the magnesium column abundance. This upper limit indicates that either Europa's surface is depleted in magnesium relative to sodium and potassium, or magnesium is not sputtered as efficiently resulting in a relative depletion in its atmosphere.

  3. Anticorrosive magnesium hydroxide coating on AZ31 magnesium alloy by hydrothermal method

    NASA Astrophysics Data System (ADS)

    Zhu, Yanying; Wu, Guangming; Zhao, Qing; Zhang, Yun-Hong; Xing, Guangjian; Li, Donglin

    2009-09-01

    Magnesium alloys are potential biodegradable biomaterials in orthopedic surgery. However, the rapid degradation rate has limited their application in biomedical field. A great deal of studies have been done to improve the resistance of magnesium alloys. In this article, An anticorrosive magnesium hydroxide coating with a thickness of approximately 100μm was formed on an AZ31 magnesium alloy by hydrothermal method. The morphology of the coatings were observed by an optical microscope and SEM. And the samples were soaked in hank's solution (37°C) to investigate the corrosion resistance. Magnesium alloy AZ31 with magnesium hydroxide coatings present superior corrosion resistance than untreated samples.

  4. Method for magnesium sulfate recovery

    DOEpatents

    Gay, Richard L.; Grantham, LeRoy F.

    1987-01-01

    A method of obtaining magnesium sulfate substantially free from radioactive uranium from a slag containing the same and having a radioactivity level of at least about 7000 pCi/gm. The slag is ground to a particle size of about 200 microns or less. The ground slag is then contacted with a concentrated sulfuric acid under certain prescribed conditions to produce a liquid product and a solid product. The particulate solid product and a minor amount of the liquid is then treated to produce a solid residue consisting essentially of magnesium sulfate substantially free of uranium and having a residual radioactivity level of less than 1000 pCi/gm. In accordance with the preferred embodiment of the invention, a catalyst and an oxidizing agent are used during the initial acid treatment and a final solid residue has a radioactivity level of less than about 50 pCi/gm.

  5. Method for magnesium sulfate recovery

    DOEpatents

    Gay, R.L.; Grantham, L.F.

    1987-08-25

    A method is described for obtaining magnesium sulfate substantially free from radioactive uranium from a slag containing the same and having a radioactivity level of at least about 7,000 pCi/gm. The slag is ground to a particle size of about 200 microns or less. The ground slag is then contacted with a concentrated sulfuric acid under certain prescribed conditions to produce a liquid product and a solid product. The particulate solid product and a minor amount of the liquid is then treated to produce a solid residue consisting essentially of magnesium sulfate substantially free of uranium and having a residual radioactivity level of less than 1,000 pCi/gm. In accordance with the preferred embodiment of the invention, a catalyst and an oxidizing agent are used during the initial acid treatment and a final solid residue has a radioactivity level of less than about 50 pCi/gm.

  6. Substrate and method for the formation of continuous magnesium diboride and doped magnesium diboride wire

    DOEpatents

    Suplinskas, Raymond J.; Finnemore, Douglas; Bud'ko, Serquei; Canfield, Paul

    2007-11-13

    A chemically doped boron coating is applied by chemical vapor deposition to a silicon carbide fiber and the coated fiber then is exposed to magnesium vapor to convert the doped boron to doped magnesium diboride and a resultant superconductor.

  7. Method for removing magnesium from aluminum-magnesium alloys with engineered scavenger compound

    SciTech Connect

    Riley, W.D.; Jong, B.W.

    1994-12-31

    The invention relates to a method for removal and production of high purity magnesium from aluminum-magnesium alloys using an engineered scanvenger compound. In particular, the invention relates to a method for removal and production of high purity magnesium from aluminum-magnesium alloys using the engineered scanvenger compound (ESC) lithium titanate (Li2O3TiO2). The removal of magnesium from the aluminum-magnesium alloys is performed at about 600-750 C in a molten salt bath of KCl or KCl-MgCl2 using lithium titanate (Li2O3TiO2) as the engineered scavenger compound (ESC). Electrode deposition of magnesium from the loaded ESC onto a stainless steel electrode is accomplished in a second step, and provides a clean magnesium electrode deposit for recycling. The second step also prepares the ESC for reuse.

  8. Lightweight Heat Pipes Made from Magnesium

    NASA Technical Reports Server (NTRS)

    Rosenfeld, John N.; Zarembo, Sergei N.; Eastman, G. Yale

    2010-01-01

    Magnesium has shown promise as a lighter-weight alternative to the aluminum alloys now used to make the main structural components of axially grooved heat pipes that contain ammonia as the working fluid. Magnesium heat-pipe structures can be fabricated by conventional processes that include extrusion, machining, welding, and bending. The thermal performances of magnesium heat pipes are the same as those of equal-sized aluminum heat pipes. However, by virtue of the lower mass density of magnesium, the magnesium heat pipes weigh 35 percent less. Conceived for use aboard spacecraft, magnesium heat pipes could also be attractive as heat-transfer devices in terrestrial applications in which minimization of weight is sought: examples include radio-communication equipment and laptop computers.

  9. IMPROVED MAGNESIUM OXIDE SLIP CASTING METHOD

    DOEpatents

    Stoddard, S.D.; Nuckolls, D.E.

    1963-12-31

    A process for making an aqueous magnesium oxide slip casting slurry comprising the steps of mixing finely ground fused magnesium oxide with water, milling the slurry for at least 30 hours at a temperature of 2-10 deg C (the low temperature during milling inhibiting the formation of hydrated magnesium oxide), discharging the slurry from the mill, adding hydrochloric acid as a deflocculent, and adding a scum inhibitor is presented. (AEC)

  10. 21 CFR 184.1425 - Magnesium carbonate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Magnesium carbonate. 184.1425 Section 184.1425... Listing of Specific Substances Affirmed as GRAS § 184.1425 Magnesium carbonate. (a) Magnesium carbonate (molecular formula approximately (MgCO3)4·Mg(OH)2·5H2O, CAS Reg. No. 39409-82-0) is also known as...

  11. 21 CFR 184.1425 - Magnesium carbonate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Magnesium carbonate. 184.1425 Section 184.1425... Listing of Specific Substances Affirmed as GRAS § 184.1425 Magnesium carbonate. (a) Magnesium carbonate (molecular formula approximately (MgCO3)4·Mg(OH)2·5H2O, CAS Reg. No. 39409-82-0) is also known as...

  12. 21 CFR 862.1495 - Magnesium test system.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... magnesium levels in serum and plasma. Magnesium measurements are used in the diagnosis and treatment of hypomagnesemia (abnormally low plasma levels of magnesium) and hypermagnesemia (abnormally high plasma levels...

  13. 21 CFR 862.1495 - Magnesium test system.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... magnesium levels in serum and plasma. Magnesium measurements are used in the diagnosis and treatment of hypomagnesemia (abnormally low plasma levels of magnesium) and hypermagnesemia (abnormally high plasma levels...

  14. 21 CFR 862.1495 - Magnesium test system.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... magnesium levels in serum and plasma. Magnesium measurements are used in the diagnosis and treatment of hypomagnesemia (abnormally low plasma levels of magnesium) and hypermagnesemia (abnormally high plasma levels...

  15. 21 CFR 862.1495 - Magnesium test system.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... magnesium levels in serum and plasma. Magnesium measurements are used in the diagnosis and treatment of hypomagnesemia (abnormally low plasma levels of magnesium) and hypermagnesemia (abnormally high plasma levels...

  16. 21 CFR 862.1495 - Magnesium test system.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... magnesium levels in serum and plasma. Magnesium measurements are used in the diagnosis and treatment of hypomagnesemia (abnormally low plasma levels of magnesium) and hypermagnesemia (abnormally high plasma levels...

  17. The TMS Magnesium Committee: Committed to the Advancement of Global Magnesium Technology

    SciTech Connect

    Sillekens, Wim H.; Nyberg, Eric A.

    2011-04-21

    The TMS Magnesium Committee was established in the year 2000 as a spin-off of the Reactive Metals Committee, triggered by the strong global growth of magnesium being used in a variety of structural lightweight applications since the mid-1990’s. Since then the committee has seen a distinct development in terms of size, participation and focus. The article at hand outlines this development by recapitulating the output of its two main activities: the annual Magnesium Technology Symposia and the JOM Special Issues dedicated to magnesium research and development. Further records on the Magnesium Committee are available from the committee homepage (accessible through http://members.tms.org).

  18. Photoelastic properties of magnesium fluoride

    SciTech Connect

    Chung, S.; Carleton, H.R.

    1980-05-01

    Magnesium fluoride (MgF/sub 2/) has the rutile crystal structure with a tetragonal space lattice (P4/mnm). The crystal is uniaxial positive with n/sub omega/ = 1.378 and n/sub epsilon/ = 1.390 for sodium D light. A single crystal of MgF/sub 2/ grown by the Materials Research Corporation was used in this study. The crystal was approximately 1 cm/sup 3/ with polished faces in the (001), (110), and (anti 110) crystal planes as verified by the back-reflection Laue method. Sample preparations and measurements are described.

  19. Exoelectron emission from magnesium surfaces

    NASA Astrophysics Data System (ADS)

    Klar, F.; Bansmann, J.; Glaefeke, H.; Fitting, H.-J.; Meiwes-Broer, K.-H.

    1999-12-01

    Clean magnesium surfaces were created by evaporating Mg onto silicon wafers. When exposing the Mg surface to a low oxygen partial pressure, an exoelectron emission (EEE) is observed after a time delay of the order of several hours after evaporation. On a much shorter time scale, similar effects in exoemission from Mg and alkali metals have been observed previously. The results are discussed within a 'potential emission' model of exoelectrons during oxygen capture at the pure Mg surface, but extending the model by including an escape mechanism. A macroscopic quantitative description of the model is given, which is in good agreement with our measurements.

  20. 21 CFR 184.1443 - Magnesium sulfate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Magnesium sulfate. 184.1443 Section 184.1443 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) DIRECT FOOD SUBSTANCES AFFIRMED AS GENERALLY RECOGNIZED AS SAFE Listing of Specific Substances Affirmed as GRAS § 184.1443 Magnesium sulfate. (a)...

  1. 21 CFR 184.1426 - Magnesium chloride.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Magnesium chloride. 184.1426 Section 184.1426 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) DIRECT FOOD SUBSTANCES AFFIRMED AS GENERALLY RECOGNIZED AS SAFE Listing of Specific Substances Affirmed as GRAS § 184.1426 Magnesium chloride. (a)...

  2. 21 CFR 184.1428 - Magnesium hydroxide.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Magnesium hydroxide. 184.1428 Section 184.1428 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) DIRECT FOOD SUBSTANCES AFFIRMED AS GENERALLY RECOGNIZED AS SAFE Listing of Specific Substances Affirmed as GRAS § 184.1428 Magnesium hydroxide....

  3. 21 CFR 582.1431 - Magnesium oxide.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Magnesium oxide. 582.1431 Section 582.1431 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE General Purpose Food Additives § 582.1431 Magnesium oxide. (a)...

  4. 21 CFR 582.5431 - Magnesium oxide.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Magnesium oxide. 582.5431 Section 582.5431 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients and/or Dietary Supplements 1 § 582.5431 Magnesium oxide. (a)...

  5. Nanostructured magnesium increases bone cell density

    NASA Astrophysics Data System (ADS)

    Weng, Lucy; Webster, Thomas J.

    2012-12-01

    Magnesium has attracted some attention in orthopedics due to its biodegradability and mechanical properties. Since magnesium is an essential natural mineral for bone growth, it can be expected that as a biomaterial, it would support bone formation. However, upon degradation in the body, magnesium releases OH- which results in an alkaline pH that can be detrimental to cell density (for example, osteoblasts or bone forming cells). For this reason, modification of magnesium may be necessary to compensate for such detrimental effects to cells. This study created biologically inspired nanoscale surface features on magnesium by soaking magnesium in various concentrations of NaOH (from 1 to 10 N) and for various periods of time (from 10 to 30 min). The results provided the first evidence of increased roughness, surface energy, and consequently greater osteoblast adhesion, after 4 h as well as density up to 7 days on magnesium treated with any concentration of NaOH for any length of time compared to untreated controls. For these reasons, this study suggests that soaking magnesium in NaOH could be an inexpensive, simple and effective manner to promote osteoblast functions for numerous orthopedic applications and, thus, should be further studied.

  6. Surface Analytical Methods Applied to Magnesium Corrosion.

    PubMed

    Dauphin-Ducharme, Philippe; Mauzeroll, Janine

    2015-08-01

    Understanding magnesium alloy corrosion is of primary concern, and scanning probe techniques are becoming key analytical characterization methods for that purpose. This Feature presents recent trends in this field as the progressive substitution of steel and aluminum car components by magnesium alloys to reduce the overall weight of vehicles is an irreversible trend. PMID:25826577

  7. 21 CFR 182.2437 - Magnesium silicate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Magnesium silicate. 182.2437 Section 182.2437 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) SUBSTANCES GENERALLY RECOGNIZED AS SAFE Anticaking Agents § 182.2437 Magnesium silicate. (a) Product....

  8. Imparting passivity to vapor deposited magnesium alloys

    NASA Astrophysics Data System (ADS)

    Wolfe, Ryan C.

    Magnesium has the lowest density of all structural metals. Utilization of low density materials is advantageous from a design standpoint, because lower weight translates into improved performance of engineered products (i.e., notebook computers are more portable, vehicles achieve better gas mileage, and aircraft can carry more payload). Despite their low density and high strength to weight ratio, however, the widespread implementation of magnesium alloys is currently hindered by their relatively poor corrosion resistance. The objective of this research dissertation is to develop a scientific basis for the creation of a corrosion resistant magnesium alloy. The corrosion resistance of magnesium alloys is affected by several interrelated factors. Among these are alloying, microstructure, impurities, galvanic corrosion effects, and service conditions, among others. Alloying and modification of the microstructure are primary approaches to controlling corrosion. Furthermore, nonequilibrium alloying of magnesium via physical vapor deposition allows for the formation of single-phase magnesium alloys with supersaturated concentrations of passivity-enhancing elements. The microstructure and surface morphology is also modifiable during physical vapor deposition through the variation of evaporation power, pressure, temperature, ion bombardment, and the source-to-substrate distance. Aluminum, titanium, yttrium, and zirconium were initially chosen as candidates likely to impart passivity on vapor deposited magnesium alloys. Prior to this research, alloys of this type have never before been produced, much less studied. All of these metals were observed to afford some degree of corrosion resistance to magnesium. Due to the especially promising results from nonequilibrium alloying of magnesium with yttrium and titanium, the ternary magnesium-yttrium-titanium system was investigated in depth. While all of the alloys are lustrous, surface morphology is observed under the scanning

  9. Imparting passivity to vapor deposited magnesium alloys

    NASA Astrophysics Data System (ADS)

    Wolfe, Ryan C.

    Magnesium has the lowest density of all structural metals. Utilization of low density materials is advantageous from a design standpoint, because lower weight translates into improved performance of engineered products (i.e., notebook computers are more portable, vehicles achieve better gas mileage, and aircraft can carry more payload). Despite their low density and high strength to weight ratio, however, the widespread implementation of magnesium alloys is currently hindered by their relatively poor corrosion resistance. The objective of this research dissertation is to develop a scientific basis for the creation of a corrosion resistant magnesium alloy. The corrosion resistance of magnesium alloys is affected by several interrelated factors. Among these are alloying, microstructure, impurities, galvanic corrosion effects, and service conditions, among others. Alloying and modification of the microstructure are primary approaches to controlling corrosion. Furthermore, nonequilibrium alloying of magnesium via physical vapor deposition allows for the formation of single-phase magnesium alloys with supersaturated concentrations of passivity-enhancing elements. The microstructure and surface morphology is also modifiable during physical vapor deposition through the variation of evaporation power, pressure, temperature, ion bombardment, and the source-to-substrate distance. Aluminum, titanium, yttrium, and zirconium were initially chosen as candidates likely to impart passivity on vapor deposited magnesium alloys. Prior to this research, alloys of this type have never before been produced, much less studied. All of these metals were observed to afford some degree of corrosion resistance to magnesium. Due to the especially promising results from nonequilibrium alloying of magnesium with yttrium and titanium, the ternary magnesium-yttrium-titanium system was investigated in depth. While all of the alloys are lustrous, surface morphology is observed under the scanning

  10. Tape casting of magnesium oxide.

    SciTech Connect

    Ayala, Alicia; Corral, Erica L.; Loehman, Ronald E.; Bencoe, Denise Nora; Reiterer, Markus; Shah, Raja A.

    2008-02-01

    A tape casting procedure for fabricating ceramic magnesium oxide tapes has been developed as a method to produce flat sheets of sintered MgO that are thin and porous. Thickness of single layer tapes is in the range of 200-400 {micro}m with corresponding surface roughness values in the range of 10-20 {micro}m as measured by laser profilometry. Development of the tape casting technique required optimization of pretreatment for the starting magnesium oxide (MgO) powder as well as a detailed study of the casting slurry preparation and subsequent heat treatments for sintering and final tape flattening. Milling time of the ceramic powder, plasticizer, and binder mixture was identified as a primary factor affecting surface morphology of the tapes. In general, longer milling times resulted in green tapes with a noticeably smoother surface. This work demonstrates that meticulous control of the entire tape casting operation is necessary to obtain high-quality MgO tapes.

  11. Magnesium bicarbonate as an in situ uranium lixiviant

    SciTech Connect

    Sibert, J.W.

    1984-09-25

    In the subsurface solution mining of mineral values, especially uranium, in situ, magnesium bicarbonate leaching solution is used instead of sodium, potassium and ammonium carbonate and bicarbonates. The magnesium bicarbonate solution is formed by combining carbon dioxide with magnesium oxide and water. The magnesium bicarbonate lixivant has four major advantages over prior art sodium, potassium and ammonium bicarbonates.

  12. Monitoring Biodegradation of Magnesium Implants with Sensors

    NASA Astrophysics Data System (ADS)

    Zhao, Daoli; Wang, Tingting; Guo, Xuefei; Kuhlmann, Julia; Doepke, Amos; Dong, Zhongyun; Shanov, Vesselin N.; Heineman, William R.

    2016-04-01

    Magnesium and its alloys exhibit properties such as high strength, light weight, and in vivo corrosion that make them promising candidates for the development of biodegradable metallic implant materials for bone repair, stents and other medical applications. Sensors have been used to monitor the corrosion of magnesium and its alloys by measuring the concentrations of the following corrosion products: magnesium ions, hydroxyl ions and hydrogen gas. The corrosion characterization system with home-made capillary pH and Mg2+ microsensors has been developed for real-time detection of magnesium corrosion in vitro. A hydrogen gas sensor was used to monitor the corrosion of magnesium by measuring the concentration of the hydrogen gas reaction product in vivo. The high permeability of hydrogen through skin allows transdermal monitoring of the biodegradation of a magnesium alloy implanted beneath the skin by detecting hydrogen gas at the skin surface. The sensor was used to map hydrogen concentration in the vicinity of an implanted magnesium alloy.

  13. Magnesium based degradable biomaterials: A review

    NASA Astrophysics Data System (ADS)

    Gu, Xue-Nan; Li, Shuang-Shuang; Li, Xiao-Ming; Fan, Yu-Bo

    2014-09-01

    Magnesium has been suggested as a revolutionary biodegradable metal for biomedical applications. The corrosion of magnesium, however, is too rapid to match the rates of tissue healing and, additionally, exhibits the localized corrosion mechanism. Thus it is necessary to control the corrosion behaviors of magnesium for their practical use. This paper comprehensively reviews the research progress on the development of representative magnesium based alloys, including Mg-Ca, Mg-Sr, Mg-Zn and Mg-REE alloy systems as well as the bulk metallic glass. The influence of alloying element on their microstructures, mechanical properties and corrosion behaviors is summarized. The mechanical and corrosion properties of wrought magnesium alloys are also discussed in comparison with those of cast alloys. Furthermore, this review also covers research carried out in the field of the degradable coatings on magnesium alloys for biomedical applications. Calcium phosphate and biodegradable polymer coatings are discussed based on different preparation techniques used. We also compare the effect of different coatings on the corrosion behaviors of magnesium alloys substrate.

  14. Magnesium doping of boron nitride nanotubes

    DOEpatents

    Legg, Robert; Jordan, Kevin

    2015-06-16

    A method to fabricate boron nitride nanotubes incorporating magnesium diboride in their structure. In a first embodiment, magnesium wire is introduced into a reaction feed bundle during a BNNT fabrication process. In a second embodiment, magnesium in powder form is mixed into a nitrogen gas flow during the BNNT fabrication process. MgB.sub.2 yarn may be used for superconducting applications and, in that capacity, has considerably less susceptibility to stress and has considerably better thermal conductivity than these conventional materials when compared to both conventional low and high temperature superconducting materials.

  15. Magnesium-lithium casting alloys

    NASA Technical Reports Server (NTRS)

    Latenko, V. P.; Silchenko, T. V.; Tikhonov, V. A.; Maltsev, V. P.; Korablin, V. P.

    1974-01-01

    The strength properties of magnesium-lithium alloys at room, low, and high temperatures are investigated. It is found that the alloys may have practical application at ambient temperatures up to 100 C, that negative temperatures have a favorable influence on the alloy strength, and that cyclic temperature variations have practically no effect on the strength characteristics. The influence of chemical coatings on corrosion resistance of the MgLi alloys is examined. Several facilities based on pressure casting machines, low-pressure casting machines, and magnetodynamic pumps were designed for producing MgLi alloy castings. Results were obtained for MgLi alloys reinforced with fibers having a volumetric content of 15%.

  16. Boron Clusters as Highly Stable Magnesium-Battery Electrolytes**

    PubMed Central

    Carter, Tyler J; Mohtadi, Rana; Arthur, Timothy S; Mizuno, Fuminori; Zhang, Ruigang; Shirai, Soichi; Kampf, Jeff W

    2014-01-01

    Boron clusters are proposed as a new concept for the design of magnesium-battery electrolytes that are magnesium-battery-compatible, highly stable, and noncorrosive. A novel carborane-based electrolyte incorporating an unprecedented magnesium-centered complex anion is reported and shown to perform well as a magnesium-battery electrolyte. This finding opens a new approach towards the design of electrolytes whose likelihood of meeting the challenging design targets for magnesium-battery electrolytes is very high. PMID:24519845

  17. Boron clusters as highly stable magnesium-battery electrolytes.

    PubMed

    Carter, Tyler J; Mohtadi, Rana; Arthur, Timothy S; Mizuno, Fuminori; Zhang, Ruigang; Shirai, Soichi; Kampf, Jeff W

    2014-03-17

    Boron clusters are proposed as a new concept for the design of magnesium-battery electrolytes that are magnesium-battery-compatible, highly stable, and noncorrosive. A novel carborane-based electrolyte incorporating an unprecedented magnesium-centered complex anion is reported and shown to perform well as a magnesium-battery electrolyte. This finding opens a new approach towards the design of electrolytes whose likelihood of meeting the challenging design targets for magnesium-battery electrolytes is very high. PMID:24519845

  18. Magnesium Recycling of Partially Oxidized, Mixed Magnesium-Aluminum Scrap through Combined Refining and Solid Oxide Membrane Electrolysis Processes

    SciTech Connect

    Xiaofei Guan; Peter A. Zink; Uday B. Pal; Adam C. Powell

    2012-01-01

    Pure magnesium (Mg) is recycled from 19g of partially oxidized 50.5wt.% Mg-Aluminum (Al) alloy. During the refining process, potentiodynamic scans (PDS) were performed to determine the electrorefining potential for magnesium. The PDS show that the electrorefining potential increases over time as the magnesium content inside the Mg-Al scrap decreases. Up to 100% percent of magnesium is refined from the Mg-Al scrap by a novel refining process of dissolving magnesium and its oxide into a flux followed by vapor phase removal of dissolved magnesium and subsequently condensing the magnesium vapor. The solid oxide membrane (SOM) electrolysis process is employed in the refining system to enable additional recycling of magnesium from magnesium oxide (MgO) in the partially oxidized Mg-Al scrap. The combination of the refining and SOM processes yields 7.4g of pure magnesium.

  19. Magnesium Recycling of Partially Oxidized, Mixed Magnesium-Aluminum Scrap Through Combined Refining and Solid Oxide Membrane (SOM) Electrolysis Processes

    SciTech Connect

    Guan, Xiaofei; Zink, Peter; Pal, Uday

    2012-03-11

    Pure magnesium (Mg) is recycled from 19g of partially oxidized 50.5wt.%Mg-Aluminum (Al) alloy. During the refining process, potentiodynamic scans (PDS) were performed to determine the electrorefining potential for magnesium. The PDS show that the electrorefining potential increases over time as the Mg content inside the Mg-Al scrap decreases. Up to 100% percent of magnesium is refined from the Mg-Al scrap by a novel refining process of dissolving magnesium and its oxide into a flux followed by vapor phase removal of dissolved magnesium and subsequently condensing the magnesium vapors in a separate condenser. The solid oxide membrane (SOM) electrolysis process is employed in the refining system to enable additional recycling of magnesium from magnesium oxide (MgO) in the partially oxidized Mg-Al scrap. The combination of the refining and SOM processes yields 7.4g of pure magnesium; could not collect and weigh all of the magnesium recovered.

  20. Severe hyperkalaemia peripartum with magnesium sulphate

    PubMed Central

    Morton, Adam

    2012-01-01

    A case of severe hyperkalaemia peripartum in the setting of magnesium sulphate infusion is presented. Health professionals involved in the care of high-risk pregnancies should be aware of this rare association.

  1. The USAMP magnesium powertrain cast components project

    NASA Astrophysics Data System (ADS)

    Powell, Bob R.

    2002-02-01

    Despite the demonstrated ability of magnesium alloys to significantly reduce weight at acceptable costs in many areas of an automobile, powertrain components have not benefited from this metal, primarily because the high-temperature alloys that are required for engines and transmissions are too expensive. However, the U.S. Department of Energy and the U.S. Automotive Materials Partnership have launched a project to evaluate several new, potentially low-cost magnesium alloys, design several pre-competitive power-train components for the best alloy properties, cast and dynamometer or vehicle test the components in assembled powertrains, develop a powertrain magnesium alloy design database and common alloy specification, and identify andpromote the funding of fundamental research into improved magnesium alloys and casting processes.

  2. 21 CFR 184.1434 - Magnesium phosphate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... specifications of the Food Chemicals Codex, 3d Ed. (1981), p. 179, which is incorporated by reference. Magnesium phosphate, tribasic, meets the specifications of the Food Chemicals Codex, 3d Ed. (1981), p. 180, which...

  3. 21 CFR 184.1434 - Magnesium phosphate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... specifications of the Food Chemicals Codex, 3d Ed. (1981), p. 179, which is incorporated by reference. Magnesium phosphate, tribasic, meets the specifications of the Food Chemicals Codex, 3d Ed. (1981), p. 180, which...

  4. 21 CFR 184.1434 - Magnesium phosphate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... phosphoric acid. (b) Magnesium phosphate, dibasic, meets the specifications of the Food Chemicals Codex, 3d... specifications of the Food Chemicals Codex, 3d Ed. (1981), p. 180, which is incorporated by reference. Copies...

  5. 21 CFR 184.1434 - Magnesium phosphate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... specifications of the Food Chemicals Codex, 3d Ed. (1981), p. 179, which is incorporated by reference. Magnesium phosphate, tribasic, meets the specifications of the Food Chemicals Codex, 3d Ed. (1981), p. 180, which...

  6. Nuclear reactor shield including magnesium oxide

    DOEpatents

    Rouse, Carl A.; Simnad, Massoud T.

    1981-01-01

    An improvement in nuclear reactor shielding of a type used in reactor applications involving significant amounts of fast neutron flux, the reactor shielding including means providing structural support, neutron moderator material, neutron absorber material and other components as described below, wherein at least a portion of the neutron moderator material is magnesium in the form of magnesium oxide either alone or in combination with other moderator materials such as graphite and iron.

  7. Hydrogen in magnesium palladium thin layer structures

    NASA Astrophysics Data System (ADS)

    Kruijtzer, G. L.

    2008-02-01

    In this thesis, the study of hydrogen storage, absorption and desorption in magnesium layers is described. The magnesium layers have a thickness of 50-500 nm and are covered by a palladium layer which acts as a hydrogen dissociation/association catalyst. The study was preformed under ultra high vacuum conditions to avoid oxygen contamination. The main analysis techniques were RBS, ERD and TDS.

  8. Immunological Response to Biodegradable Magnesium Implants

    NASA Astrophysics Data System (ADS)

    Pichler, Karin; Fischerauer, Stefan; Ferlic, Peter; Martinelli, Elisabeth; Brezinsek, Hans-Peter; Uggowitzer, Peter J.; Löffler, Jörg F.; Weinberg, Annelie-Martina

    2014-04-01

    The use of biodegradable magnesium implants in pediatric trauma surgery would render surgical interventions for implant removal after tissue healing unnecessary, thereby preventing stress to the children and reducing therapy costs. In this study, we report on the immunological response to biodegradable magnesium implants—as an important aspect in evaluating biocompatibility—tested in a growing rat model. The focus of this study was to investigate the response of the innate immune system to either fast or slow degrading magnesium pins, which were implanted into the femoral bones of 5-week-old rats. The main alloying element of the fast-degrading alloy (ZX50) was Zn, while it was Y in the slow-degrading implant (WZ21). Our results demonstrate that degrading magnesium implants beneficially influence the immune system, especially in the first postoperative weeks but also during tissue healing and early bone remodeling. However, rodents with WZ21 pins showed a slightly decreased phagocytic ability during bone remodeling when the degradation rate reached its maximum. This may be due to the high release rate of the rare earth-element yttrium, which is potentially toxic. From our results we conclude that magnesium implants have a beneficial effect on the innate immune system but that there are some concerns regarding the use of yttrium-alloyed magnesium implants, especially in pediatric patients.

  9. Magnesium phosphate glass cements with ceramic-type properties

    SciTech Connect

    Sugama, T.; Kukacka, L.E.

    1984-03-13

    Rapid setting magnesium phosphate (Mg glass) cementitious materials consisting of magnesium phosphate cement paste, polyborax and water-saturated aggregate exhibiting rapid setting and high early strength characteristics. The magnesium glass cement is prepared from a cation-leachable powder and a bivalent metallic ion-accepting liquid such as an aqueous solution of diammonium phosphate and ammonium polyphosphate. The cation-leachable powder includes a mixture of two different magnesium oxide powders processed and sized differently which when mixed with the bivalent metallic ion-accepting liquid provides the magnesium glass cement consisting primarily of magnesium ortho phosphate tetrahydrate, with magnesium hydroxide and magnesium ammonium phosphate hexahydrate also present. The polyborax serves as a set-retarder. The resulting magnesium mono-and polyphosphate cements are particularly suitable for use as a cementing matrix in rapid repair systems for deteriorated concrete structures as well as construction materials and surface coatings for fireproof structures.

  10. Magnesium phosphate glass cements with ceramic-type properties

    DOEpatents

    Sugama, Toshifumi; Kukacka, Lawrence E.

    1984-03-13

    Rapid setting magnesium phosphate (Mg glass) cementitious materials consisting of magnesium phosphate cement paste, polyborax and water-saturated aggregate exhibiting rapid setting and high early strength characteristics. The magnesium glass cement is prepared from a cation-leachable powder and a bivalent metallic ion-accepting liquid such as an aqueous solution of diammonium phosphate and ammonium polyphosphate. The cation-leachable powder includes a mixture of two different magnesium oxide powders processed and sized differently which when mixed with the bivalent metallic ion-accepting liquid provides the magnesium glass cement consisting primarily of magnesium ortho phosphate tetrahydrate, with magnesium hydroxide and magnesium ammonium phosphate hexahydrate also present. The polyborax serves as a set-retarder. The resulting magnesium mono- and polyphosphate cements are particularly suitable for use as a cementing matrix in rapid repair systems for deteriorated concrete structures as well as construction materials and surface coatings for fireproof structures.

  11. Magnesium-phosphate-glass cements with ceramic-type properties

    DOEpatents

    Sugama, T.; Kukacka, L.E.

    1982-09-23

    Rapid setting magnesium phosphate (Mg glass) cementitious materials consisting of magnesium phosphate cement paste, polyborax and water-saturated aggregate, exhibits rapid setting and high early strength characteristics. The magnesium glass cement is prepared from a cation-leachable powder and a bivalent metallic ion-accepting liquid such as an aqueous solution of diammonium phosphate and ammonium polyphosphate. The cation-leachable powder includes a mixture of two different magnesium oxide powders processed and sized differently which when mixed with the bivalent metallic ion-accepting liquid provides the magnesium glass cement consisting primarily of magnesium ortho phosphate tetrahydrate, with magnesium hydroxide and magnesium ammonium phosphate hexahydrate also present. The polyborax serves as a set-retarder. The resulting magnesium mono- and polyphosphate cements are particularly suitable for use as a cementing matrix in rapid repair systems for deteriorated concrete structures as well as construction materials and surface coatings for fireproof structures.

  12. Research of magnesium phosphosilicate cement

    NASA Astrophysics Data System (ADS)

    Ding, Zhu

    Magnesium phosphosilicate cement (MPSC) is a novel phosphate bonded cement, which consists mainly of magnesia, phosphate and silicate minerals. The traditional magnesium phosphate cements (MPCs) usually composed by ammonium phosphate, and gaseous ammonia will emit during mixing and in service. There is no noxious ammonia released from MPSC, furthermore, it can recycle a large volume of the non-hazardous waste. The goal of this research is to investigate the composition, reaction products, reaction mechanism, microstructure, properties, durability and applications of the MPSC. MPSC sets rapidly and has high early strength. It reacts better with solid industrial waste when compared to Portland cement. Many solid industrial wastes, such as fly ash, steel slag, coal gangue, red coal gangue, red mud, barium-bearing slag, copper slag, silica fume, and ground granulated blast furnace slag, have been used as the main component (40% by weight) in MPSC. The research has found that these aluminosilicate (or ironsilicate, or calciumsilicate) minerals with an amorphous or glass structure can enhance the performance of MPSC. The disorganized internal structure of amorphous materials may make it possess higher reactivity compared to the crystalline phases. Chemical reaction between phosphate and these minerals may form an amorphous gel, which is favorable to the cementing. Borax, boric acid and sodium tripolyphosphate have been used as retardants in the MPSC system. It is found that boric acid has a higher retarding effect on the setting of cement, than borax does. However, sodium polyphosphate accelerates the reaction of MPSC. The hydration of MPSC is exothermic reaction. The heat evolution may prompt hydrates formation, and shorten the setting process. Modern materials characterization techniques, XRD, DSC, TG-DTA FTIR, XPS, MAS-NMR, SEM, TEM, MIP, etc. were used to analyze the phase composition, micro morphology, and microstructure of hardened MPSC. The main hydration product

  13. Magnesium isotopic composition of achondrites

    NASA Astrophysics Data System (ADS)

    Sedaghatpour, Fatemeh; Teng, Fang-Zhen

    2016-02-01

    Magnesium isotopic compositions of 22 well-characterized differentiated meteorites including 7 types of achondrites and pallasite meteorites were measured to estimate the average Mg isotopic composition of their parent bodies and evaluate Mg isotopic heterogeneity of the solar system. The δ26Mg values are -0.236‰ and -0.190‰ for acapulcoite-lodranite and angrite meteorites, respectively and vary from -0.267‰ to -0.222‰ in the winonaite-IAB-iron silicate group, -0.369‰ to -0.292‰ in aubrites, -0.269‰ to -0.158‰ in HEDs, -0.299‰ to -0.209‰ in ureilites, -0.307‰ to -0.237‰ in mesosiderites, and -0.303‰ to -0.238‰ in pallasites. Magnesium isotopic compositions of most achondrites and pallasite meteorites analyzed here are similar and reveal no significant isotopic fractionation. However, Mg isotopic compositions of D‧Orbigny (angrite) and some HEDs are slightly heavier than chondrites and the other achondrites studied here. The slightly heavier Mg isotopic compositions of angrites and some HEDs most likely resulted from either impact-induced evaporation or higher abundance of clinopyroxene with the Mg isotopic composition slightly heavier than olivine and orthopyroxene. The average Mg isotopic composition of achondrites (δ26Mg = -0.246 ± 0.082‰, 2SD, n = 22) estimated here is indistinguishable from those of the Earth (δ26Mg = -0.25 ± 0.07‰; 2SD, n = 139), chondrites (δ26Mg = -0.28 ± 0.06‰; 2SD, n = 38), and the Moon (δ26Mg = -0.26 ± 0.16‰; 2SD, n = 47) reported from the same laboratory. The chondritic Mg isotopic composition of achondrites, the Moon, and the Earth further reflects homogeneity of Mg isotopes in the solar system and the lack of Mg isotope fractionation during the planetary accretion process and impact events.

  14. Isotopically pure magnesium isotope-24 is prepared from magnesium-24 oxide

    NASA Technical Reports Server (NTRS)

    Chellew, N. R.; Schilb, J. D.; Steunenberg, R. K.

    1968-01-01

    Apparatus is used to prepare isotopically pure magnesium isotope-24, suitable for use in neutron scattering and polarization experiments. The apparatus permits thermal reduction of magnesium-24 oxide with aluminum and calcium oxide, and subsequent vaporization of the product metal in vacuum. It uses a resistance-heated furnace tube and cap assembly.

  15. Production of Magnesium by Vacuum Aluminothermic Reduction with Magnesium Aluminate Spinel as a By-Product

    NASA Astrophysics Data System (ADS)

    Wang, Yaowu; You, Jing; Peng, Jianping; Di, Yuezhong

    2016-03-01

    The Pidgeon process currently accounts for 85% of the world's magnesium production. Although the Pidgeon process has been greatly improved over the past 10 years, such production still consumes much energy and material and creates much pollution. The present study investigates the process of producing magnesium by employing vacuum aluminothermic reduction and by using magnesite as material and obtaining magnesium aluminate spinel as a by-product. The results show that compared with the Pidgeon process, producing magnesium by vacuum aluminothermic reduction can save materials by as much as 50%, increase productivity up to 100%, and save energy by more than 50%. It can also reduce CO2 emission by up to 60% and realize zero discharge of waste residue. Vacuum aluminothermic reduction is a highly efficient, low-energy-consumption, and environmentally friendly method of producing magnesium.

  16. Production of Magnesium by Vacuum Aluminothermic Reduction with Magnesium Aluminate Spinel as a By-Product

    NASA Astrophysics Data System (ADS)

    Wang, Yaowu; You, Jing; Peng, Jianping; Di, Yuezhong

    2016-06-01

    The Pidgeon process currently accounts for 85% of the world's magnesium production. Although the Pidgeon process has been greatly improved over the past 10 years, such production still consumes much energy and material and creates much pollution. The present study investigates the process of producing magnesium by employing vacuum aluminothermic reduction and by using magnesite as material and obtaining magnesium aluminate spinel as a by-product. The results show that compared with the Pidgeon process, producing magnesium by vacuum aluminothermic reduction can save materials by as much as 50%, increase productivity up to 100%, and save energy by more than 50%. It can also reduce CO2 emission by up to 60% and realize zero discharge of waste residue. Vacuum aluminothermic reduction is a highly efficient, low-energy-consumption, and environmentally friendly method of producing magnesium.

  17. 40 CFR 461.60 - Applicability; description of the magnesium subcategory.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... magnesium subcategory. 461.60 Section 461.60 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Magnesium Subcategory § 461.60 Applicability; description of the magnesium subcategory. This subpart applies... treatment works from the manufacturing of magnesium anode batteries....

  18. 40 CFR 461.60 - Applicability; description of the magnesium subcategory.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... magnesium subcategory. 461.60 Section 461.60 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Magnesium Subcategory § 461.60 Applicability; description of the magnesium subcategory. This subpart applies... treatment works from the manufacturing of magnesium anode batteries....

  19. 40 CFR 461.60 - Applicability; description of the magnesium subcategory.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... magnesium subcategory. 461.60 Section 461.60 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Magnesium Subcategory § 461.60 Applicability; description of the magnesium subcategory. This subpart applies... treatment works from the manufacturing of magnesium anode batteries....

  20. Grosnaja ABCs: Magnesium isotope compositions

    NASA Technical Reports Server (NTRS)

    Goswami, J. N.; Srinivasan, G.; Ulyanov, A. A.

    1993-01-01

    Three CAI's from the Grosnaja CV3 chondrite were analyzed for their magnesium isotopic compositions by the ion microprobe. The selected CAI's represent three distinct types: GR4(compact Type A), GR7(Type B) and GR2(Type C). Petrographic studies indicate that all three Grosnaja inclusions were subjected to secondary alterations. The Type A CAI GR4 is primarily composed of melilite with spinel and pyroxene occurring as minor phases. The rim of the inclusion does not exhibit distinct layered structure and secondary alteration products (garnet, Fe-rich olivine and Na-rich plagioclase) are present in some localized areas near the rim region. The average major element compositions of different mineral phases in GR4 are given. Preliminary REE data suggest a depletion of HREE relative to LREE by about a factor of 3 without any clear indication of interelement fractionation. The CAI GR7 has textural and minerological characteristics similar to Type B inclusions. The REE data show a pattern that is similar to Group 6 with enrichment in Eu and Yb. In addition, a depletion of HREE compared to LREE is also evident in this object. Melilite composition shows a broad range of akermanite content (Ak(sub 15-55)). Detailed petrographic study is in progress. GR2 is a anorthite-rich Type C inclusion with large plagioclase laths intergrown with Ti-rich pyroxene. The average plagioclase composition is close to pure anorthite (An99).

  1. Leaf Senescence by Magnesium Deficiency

    PubMed Central

    Tanoi, Keitaro; Kobayashi, Natsuko I.

    2015-01-01

    Magnesium ions (Mg2+) are the second most abundant cations in living plant cells, and they are involved in various functions, including photosynthesis, enzyme catalysis, and nucleic acid synthesis. Low availability of Mg2+ in an agricultural field leads to a decrease in yield, which follows the appearance of Mg-deficient symptoms such as chlorosis, necrotic spots on the leaves, and droop. During the last decade, a variety of physiological and molecular responses to Mg2+ deficiency that potentially link to leaf senescence have been recognized, allowing us to reconsider the mechanisms of Mg2+ deficiency. This review focuses on the current knowledge about the physiological responses to Mg2+ deficiency including a decline in transpiration, accumulation of sugars and starch in source leaves, change in redox states, increased oxidative stress, metabolite alterations, and a decline in photosynthetic activity. In addition, we refer to the molecular responses that are thought to be related to leaf senescence. With these current data, we give an overview of leaf senescence induced by Mg deficiency. PMID:27135350

  2. Magnesium and anabolic hormones in older men

    PubMed Central

    Maggio, M.; Ceda, G. P.; Lauretani, F.; Cattabiani, C.; Avantaggiato, E.; Morganti, S.; Ablondi, F.; Bandinelli, S.; Dominguez, L. J.; Barbagallo, M.; Paolisso, G.; Semba, R. D.; Ferrucci, L.

    2015-01-01

    Summary Optimal nutritional and hormonal statuses are determinants of successful ageing. The age associated decline in anabolic hormones such as testosterone and insulin-like growth factor 1 (IGF-1) is a strong predictor of metabolic syndrome, diabetes and mortality in older men. Studies have shown that magnesium intake affects the secretion of total IGF-1 and increase testosterone bioactivity. This observation suggests that magnesium can be a modulator of the anabolic/catabolic equilibrium disrupted in the elderly people. However, the relationship between magnesium and anabolic hormones in men has not been investigated. We evaluated 399 ≥65-year-old men of CHIANTI in a study population representative of two municipalities of Tuscany (Italy) with complete data on testosterone, total IGF-1, sex hormone binding globulin (SHBG), dehydroepiandrosterone sulphate (DHEAS) and serum magnesium levels. Linear regression models were used to test the relationship between magnesium and testosterone and IGF-1. Mean age of the population was 74.18 ± 6.43 (years ± SD, age range 65.2–92.4). After adjusting for age, magnesium was positively associated with total testosterone (β ± SE, 34.9 ± 10.3; p = 0.001) and with total IGF-1 (β ± SE, 15.9 ± 4.8; p = 0.001). After further adjustment for body mass index (BMI), log (IL-6), log (DHEAS), log (SHBG), log (insulin), total IGF-1, grip strength, Parkinson’s disease and chronic heart failure, the relationship between magnesium and total testosterone remained strong and highly significant (β ± SE, 48.72 ± 12.61; p = 0.001). In the multivariate analysis adjusted for age, BMI, log (IL-6), liver function, energy intake, log (insulin), log (DHEAS), selenium, magnesium levels were also still significantly associated with IGF-1 (β ± SE, 16.43 ± 4.90; p = 0.001) and remained significant after adjusting for total testosterone (β ± SE, 14.4 ± 4.9; p = 0.01). In a cohort of older men, magnesium levels are strongly and

  3. Magnesium deficiency is associated with periodontal disease.

    PubMed

    Meisel, P; Schwahn, C; Luedemann, J; John, U; Kroemer, H K; Kocher, T

    2005-10-01

    In the multifactorial pathogenesis of periodontitis, there are still unknown factors influencing the outcome of the disease. An association between magnesium and periodontitis has been suggested by preliminary studies. However, relevant clinical data are lacking. We investigated the association between magnesium status and periodontal health in a population-based analysis. We conducted a cross-sectional epidemiological investigation involving 4290 subjects aged 20-80 yrs. We recorded periodontal risk factors and determined concentrations of serum magnesium and calcium, relating them to periodontal parameters. In a matched-pair study, 60 subjects using oral magnesium-containing drugs and 120 without were compared. In subjects aged 40 yrs and older, increased serum Mg/Ca was significantly associated with reduced probing depth (p<0.001), less attachment loss (p=0.006), and a higher number of remaining teeth (p=0.005). Subjects taking Mg drugs showed less attachment loss (p<0.01) and more remaining teeth than did their matched counterparts. These results suggest that nutritional magnesium supplementation may improve periodontal health. PMID:16183794

  4. Combustion Synthesis of Magnesium Aluminate

    NASA Astrophysics Data System (ADS)

    Kale, M. A.; Joshi, C. P.; Moharil, S. V.

    2011-10-01

    In the system MgO-Al2O3, three compounds MgAl2O4, MgAl6O10 (also expressed as- Mg0.4Al2.4O4) and MgAl26O40 are well known. Importance of the first two is well established. Magnesium aluminate (MgAl2O4) spinel is a technologically important material due to its interesting thermal properties. The MgAl2O4 ceramics also find application as humidity sensors. Apart from the luminescence studies, the interest in MgAl2O4 is due to various applications such as humidity-sensing and PEM fuel cells, TL/OSL dosimetry of the ionizing radiations, white light source. Interest in the MgAl6O10 has aroused due to possible use as a substrate for GaN growth. Attempt was made to synthesize these compounds by the combustion synthesis using metal nitrates as oxidizer and urea as a fuel. Compounds MgAl2O4 and MgAl6O10 were formed in a single step, while MgAl26O40 was not formed by this procedure. Activation of MgAl6O10 by rare earth ions like Ce3+, Eu3+ and Tb3+ and ns2 ion Pb2+ could be achieved. Excitation bands for MgAl6O10 are at slightly shorter wavelengths compared to those reported for MgAl2O4.

  5. Combustion Synthesis of Magnesium Aluminate

    SciTech Connect

    Kale, M. A.; Joshi, C. P.; Moharil, S. V.

    2011-10-20

    In the system MgO-Al{sub 2}O{sub 3}, three compounds MgAl{sub 2}O{sub 4}, MgAl{sub 6}O{sub 10}(also expressed as-Mg{sub 0.4}Al{sub 2.4}O{sub 4}) and MgAl{sub 26}O{sub 40} are well known. Importance of the first two is well established. Magnesium aluminate (MgAl{sub 2}O{sub 4}) spinel is a technologically important material due to its interesting thermal properties. The MgAl{sub 2}O{sub 4} ceramics also find application as humidity sensors. Apart from the luminescence studies, the interest in MgAl{sub 2}O{sub 4} is due to various applications such as humidity-sensing and PEM fuel cells, TL/OSL dosimetry of the ionizing radiations, white light source. Interest in the MgAl{sub 6}O{sub 10} has aroused due to possible use as a substrate for GaN growth. Attempt was made to synthesize these compounds by the combustion synthesis using metal nitrates as oxidizer and urea as a fuel. Compounds MgAl{sub 2}O{sub 4} and MgAl{sub 6}O{sub 10} were formed in a single step, while MgAl{sub 26}O{sub 40} was not formed by this procedure. Activation of MgAl{sub 6}O{sub 10} by rare earth ions like Ce{sup 3+}, Eu{sup 3+} and Tb{sup 3+} and ns{sup 2} ion Pb{sup 2+} could be achieved. Excitation bands for MgAl{sub 6}O{sub 10} are at slightly shorter wavelengths compared to those reported for MgAl{sub 2}O{sub 4}.

  6. Magnesium-lithium alloys developed for low temperature use

    NASA Technical Reports Server (NTRS)

    Dunkerley, F. J.; Leavenworth, H. W., Jr.

    1967-01-01

    Three new magnesium-lithium alloys have been developed for application at cryogenic temperatures. These lightweight alloys have approximately doubled the tensile and yield strengths at room temperature of previously described magnesium-lithium alloys.

  7. Ice-melting characteristics of calcium magnesium acetate

    NASA Astrophysics Data System (ADS)

    Schenk, R. U.

    1986-01-01

    The objectives of the study are to determine the pertinent properties of Calcium/Magnesium Acetate and to determine the pH and ratio of calcium to magnesium that provide optimum road deicing characteristics.

  8. Alkalization is responsible for antibacterial effects of corroding magnesium.

    PubMed

    Rahim, Muhammad Imran; Eifler, Rainer; Rais, Bushra; Mueller, Peter P

    2015-11-01

    Magnesium alloys are presently investigated as potential medical implant materials for temporary applications. Magnesium has been reported to have antibacterial activities and could therefore be used to prevent antibiotic treatment-resistant bacterial implant infections. For characterizing the effects of magnesium on infectious bacteria, bioluminescent S. aureus or P. aeruginosa were employed. The proliferation of both types of bacteria was suppressed in the presence of metallic magnesium and also in aqueous magnesium corrosion extracts. Of the two soluble corrosion products, magnesium ions were well tolerated while antibacterial activities correlated with increased pH levels of the supernatants. The alkaline pH alone was sufficient for the antibacterial effects which were completely abolished when the pH of the corrosion supernatants was neutralized. These results demonstrate that pH increases are necessary and sufficient for the antibacterial activity of metallic magnesium. In an animal model magnesium implants showed an enhanced but variable resistance to bacterial colonization. PMID:25974048

  9. Simulating the dynamic response of magnesium alloys

    NASA Astrophysics Data System (ADS)

    Lloyd, Jeffrey; Becker, Richard

    Unlike several conventional metals, the mechanical response of magnesium is severely anisotropic for quasistatic and dynamic loading conditions. In this work we present a crystal-based strength model that is the same order of magnitude in computational cost as rate-dependent isotropic strength models, yet is able to capture essential features exhibited by textured magnesium polycrystals. The model demarcates plastic deformation into contributions from basal slip, extension twinning, and non-basal slip mechanisms. Comparisons are made between model predictions and experiments for two magnesium alloys with differing processing histories. The model is then used to explore and quantify the dependence of metallurgical and processing variations for several dynamic experiments that probe propensity for localization and failure under complex loading conditions.

  10. Solubility of magnesium carbonate in natural waters

    USGS Publications Warehouse

    Wells, R.C.

    1915-01-01

    (1) Under atmospheric conditions it appears possible to attain practically the same state in a solution saturated with MgCO33H2O, whether one starts with a solution containing an excess of magnesium bicarbonate or with the pure trihydrate and water, but the adjustment occurs very slowly. The solution finally contains 0.36 g. magnesium and 1.01 g. carbon dioxide per liter at 20??. (2) The solubility found for magnesite, however, is much smaller, viz., 0.02 g. magnesium and 0.07 g. carbon dioxide per liter. (3) Certain natural waters, freely exposed to the atmosphere, appear to be supersaturated with respect to magnesite but none approaches very closely to the point of saturation of the trihydrate MgCO3.3H2O.

  11. Magnesium sulfate administration in subarachnoid hemorrhage.

    PubMed

    Suarez, Jose I

    2011-09-01

    Magnesium offers theoretic vascular and neuroprotective benefits for patients with subarachnoid hemorrhage. An electronic literature search was conducted to identify original research studies describing intravenous magnesium treatment in patients with SAH published in English between January 1990 and October 2010. Seventeen articles were identified and reviewed, including one phase III randomized-controlled clinical trial and six phase II randomized-controlled trials. Study quality was low for most of the included studies, with the phase III trial considered to be of moderate quality. Due to inconsistently reported benefits and the occurrence of side effects, phase II data suggested that intravenous magnesium for SAH provided either no overall net benefit or uncertain trade-offs. Benefit was likewise not supported in the single phase III clinical trial. PMID:21748496

  12. Organochlorine formation in magnesium electrowinning cells.

    PubMed

    Deutscher, R L; Cathro, K J

    2001-04-01

    The formation of organochlorines during the electrolytic production of magnesium was investigated using a laboratory-scale electrolytic cell having a graphite anode, a liquid aluminium alloy cathode, and a molten chloride electrolyte. The cell was operated at current densities ranging from 3000 to 10,000 A m(-2) and at temperatures ranging from 660 degrees C to 750 degrees C. Organochlorines were adsorbed from the cell off-gases onto silica gel, extracted with hexane, and determined by gas chromatography. All compounds identified were fully chlorinated aliphatic and aromatic compounds, the major components being hexachlorobutadiene, hexachlorobenzene, hexachloroethylene, and octachlorostyrene. The total amount of organochlorines per tonne of magnesium produced decreased with electrolysis time and with current density and increased with operating temperature; it was also dependent on the type of graphite employed. The output of organochlorines varied from 5 to 20 g t(-1) of magnesium. PMID:11297394

  13. Borosilicate glass alteration driven by magnesium carbonates

    NASA Astrophysics Data System (ADS)

    Debure, M.; Frugier, P.; De Windt, L.; Gin, S.

    2012-01-01

    The alteration of simplified synthetic glass, representative of the French reference nuclear glass R7T7, in presence of hydromagnesite has been experimentally investigated and modeled. Magnesium in solution is known to potentially enhance glass alteration; nuclear glass clayed host rocks contain magnesium and can dissolve to maintain the concentration of magnesium in solution. For modeling purposes, it was suitable to study a simple system. Hydromagnesite was therefore chosen as a simple model mineral in order to check the influence of an Mg-rich mineral on glass alteration. Since the models use thermodynamic and kinetic parameters measured in pure water and pH-buffered solutions, changing the solution composition or adding minerals is a key step towards the validation of the modeling assumptions before using the model for predictive purposes. Experiments revealed that glass alteration is enhanced in presence of hydromagnesite. Modeling was performed using the GRAAL model implemented within the CHESS/HYTEC reactive transport code. Modeling proved useful both for explaining the mechanisms involved and quantifying the impact on glass alteration: Mg coming from hydromagnesite dissolution reacts with Si provided by the glass in order to form magnesium silicates. This reaction decreases the pH down to neutral conditions where magnesium silicates are more soluble than at the natural alkali pH imposed by glass or hydromagnesite dissolution. The driving force of the magnesium silicate precipitation is eventually the interdiffusion of alkali within the altered amorphous glass layer as this mechanism consumes protons. The model's ability to describe the concentrations of elements in solution and formed solids whatever the glass/hydromagnesite ratio strongly supports the basic modeling hypothesis.

  14. Electrodeposition of aluminium, aluminium/magnesium alloys, and magnesium from organometallic electrolytes

    SciTech Connect

    Mayer, A.

    1988-01-01

    The electrodeposition of aluminum, magnesium, and the combination of these metals from nonaqueous media is discussed. Plating baths for depositing Al/Mg alloys or for plating essentially pure Mg were developed. These solutions contain alkali meal fluoride or quaternary ammonium halide/aluminium alkyl complexes and dialkyl magnesium dissolved in aromatic hydrocarbons. Alloy deposits over the whole composition range can be plated from these solutions by varying the relative quantities of the aluminium and magnesium alkyls and by changing the bath-operating parameters. 18 refs., 4 figs.

  15. Preparation of petaloid microspheres of basic magnesium carbonate.

    PubMed

    Ohkubo, Takahiro; Suzuki, Sei; Mitsuhashi, Kohei; Ogura, Taku; Iwanaga, Shinichi; Sakai, Hideki; Koishi, Masumi; Abe, Masahiko

    2007-05-22

    The synthesis of basic magnesium carbonate was examined under ultrasonic irradiation and was performed by the soda ash method using magnesium sulfate and sodium carbonate as starting materials. The particulate product was evaluated using SEM observations. Ultrasonic irradiation in the preparation of basic magnesium carbonate was found to give fine petaloid microspheres of about 3 mum in primary particle size. PMID:17458985

  16. 40 CFR 721.9513 - Modified magnesium silicate polymer (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Modified magnesium silicate polymer... Specific Chemical Substances § 721.9513 Modified magnesium silicate polymer (generic). (a) Chemical... as modified magnesium silicate polymer (PMN P-98-604) is subject to reporting under this section...

  17. Magnesium Intake and Prevalence of Metabolic Syndrome in Older Adults

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Higher dietary intake of magnesium (Mg) may protect against development of type 2 diabetes. The aim of this study was to examine the association between dietary magnesium intake and metabolic syndrome risk factors in elderly men and women. We examined cross-sectional associations between magnesium i...

  18. 40 CFR 721.10504 - Surface modified magnesium hydroxide (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Surface modified magnesium hydroxide... Specific Chemical Substances § 721.10504 Surface modified magnesium hydroxide (generic). (a) Chemical... as surface modified magnesium hydroxide (PMN P-06-682) is subject to reporting under this section...

  19. 40 CFR 721.9513 - Modified magnesium silicate polymer (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Modified magnesium silicate polymer... Specific Chemical Substances § 721.9513 Modified magnesium silicate polymer (generic). (a) Chemical... as modified magnesium silicate polymer (PMN P-98-604) is subject to reporting under this section...

  20. 40 CFR 721.9513 - Modified magnesium silicate polymer (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Modified magnesium silicate polymer... Specific Chemical Substances § 721.9513 Modified magnesium silicate polymer (generic). (a) Chemical... as modified magnesium silicate polymer (PMN P-98-604) is subject to reporting under this section...

  1. 40 CFR 721.10504 - Surface modified magnesium hydroxide (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Surface modified magnesium hydroxide... Specific Chemical Substances § 721.10504 Surface modified magnesium hydroxide (generic). (a) Chemical... as surface modified magnesium hydroxide (PMN P-06-682) is subject to reporting under this section...

  2. 40 CFR 721.9513 - Modified magnesium silicate polymer (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Modified magnesium silicate polymer... Specific Chemical Substances § 721.9513 Modified magnesium silicate polymer (generic). (a) Chemical... as modified magnesium silicate polymer (PMN P-98-604) is subject to reporting under this section...

  3. Magnesium retention in 12 to 48 month-old children

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In adults, adaptation to changes in magnesium intake is largely due to changes in fractional magnesium absorption and urinary magnesium excretion. We sought to examine whether these homeostatic mechanisms also occur in young children. Children, 12–48 m old, were studied (n=30). They were adapted to ...

  4. 40 CFR 721.9513 - Modified magnesium silicate polymer (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Modified magnesium silicate polymer... Specific Chemical Substances § 721.9513 Modified magnesium silicate polymer (generic). (a) Chemical... as modified magnesium silicate polymer (PMN P-98-604) is subject to reporting under this section...

  5. Chemically Prepared Lead Magnesium Niobate Dielectrics

    SciTech Connect

    Tuttle, B.A.; Voigt, J.A.; Sipola, D.L.; Olson, W.R.; Goy, D.M.

    1998-01-01

    A chemical solution powder synthesis technique has been developed that produces fine uniform powders of lead magnesium niobate (PMN) with 60 to 80 nm crystallite size. The synthesis technique was based on the dissolution of lead acetate and alkoxide precursors in acetic acid followed by precipitation with oxalic acid/propanol solutions. Lead magnesium niobate ceramics fabricated from these chemically derived powders had smaller, more uniform grain size and higher dielectric constants than ceramics fabricated from mixed oxide powders that were processed under similar thermal conditions.

  6. Upper critical field of cellular magnesium diboride

    NASA Astrophysics Data System (ADS)

    Grinenko, V. A.

    2007-08-01

    A cellular superconducting material consisting of thin (1 20 μm) MgB2-x layers and magnesium granules of about 100 μm has been produced. The critical temperature T c of this superconductor decreases with the thickness of the MgB2-x layers. In unalloyed magnesium diboride, the curvature of the temperature dependence of the upper critical field H c2(T) changes gradually from downward to pronounced upward as the temperature T c decreases from 38 to 36 K.

  7. SOLID STATE JOINING OF MAGNESIUM TO STEEL

    SciTech Connect

    Jana, Saumyadeep; Hovanski, Yuri; Pilli, Siva Prasad; Field, David P.; Yu, Hao; Pan, Tsung-Yu; Santella, M. L.

    2012-06-04

    Friction stir welding and ultrasonic welding techniques were applied to join automotive magnesium alloys to steel sheet. The effect of tooling and process parameters on the post-weld microstructure, texture and mechanical properties was investigated. Static and dynamic loading were utilized to investigate the joint strength of both cast and wrought magnesium alloys including their susceptibility and degradation under corrosive media. The conditions required to produce joint strengths in excess of 75% of the base metal strength were determined, and the effects of surface coatings, tooling and weld parameters on weld properties are presented.

  8. Mobility of cations in magnesium aluminate spinel

    NASA Astrophysics Data System (ADS)

    Martinelli, J. R.; Sonder, E.; Weeks, R. A.; Zuhr, R. A.

    1986-04-01

    Transport of cations in magnesium aluminate spinel due to an applied electric field at approximately 1000 °C has been measured by observing changes in elemental concentrations near the cathode and anode surfaces using ion backscattering techniques. The results indicate that magnesium ions are the mobile species at 1000 °C and that these ions combine with ambient oxygen at the cathode surface to form a MgO layer. Quantitative interpretation of the data leads to the conclusion that the ionic transference number of spinel becomes approximately 0.5 after treatment in an electric field.

  9. The art of magnesium transport.

    PubMed

    de Baaij, Jeroen H F

    2015-01-01

    Patients with hypomagnesemia suffer from a wide range of symptoms including muscle cramps, cardiac arrhythmias and epilepsy. Disturbances in body Mg(2+) homeostasis can often be attributed to increased Mg(2+) excretion by the kidney. Within the kidney, the distal convoluted tubule (DCT) segment determines the final Mg(2+) excretion, since no reabsorption takes place beyond this segment of the nephron. On 21(st) of January 2015, Jeroen de Baaij defended his thesis "The Distal Convoluted Tubule: the Art of Magnesium Transport", in which he aimed to identify new genes involved in Mg(2+) reabsorption in the DCT. This review summarizes the main findings of his graduate research. TRPM6 mediates apical Mg(2+) entry into the DCT cell and is highly regulated by EGF, insulin and pH. ATP and flavagline compounds have been characterized as new regulators of TRPM6 activity, providing novel pathways to target Mg(2+) disturbances. Using isolated primary DCT cells from mice, PCBD1 was identified as a new transcriptional regulator of Mg(2+) transport in the DCT. Indeed, patients with PCBD1 mutations were shown to suffer hypomagnesemia and MODY5-like diabetes. Subsequently, the work presented in the thesis focused on the elucidation of the basolateral Mg(2+) extrusion of the DCT cell. In vivo studies using SLC41A3-knockout mice suggest that SLC41A3 may act as Mg(2+) extrusion mechanism. CNNM2 has long been hypothesized to transport Mg(2+) at the basolateral membrane of the DCT. However, by determining the protein topology and homology modeling of the CBS domains, it was argued that CNNM2 is rather an Mg(2+)-sensing mechanism. Follow-up studies using (25)Mg(2+) isotopes showed that CNNM2 increases Mg(2+) uptake when overexpressed in HEK293 cells. Additionally, by knocking down cnnm2 in zebrafish, CNNM2 was demonstrated to be essential for brain development and Mg(2+) homeostasis. Mutations in CNNM2 were shown to cause hypomagnesemia, seizures and intellectual disability. Altogether

  10. Magnesium status and association with diabetes in the Taiwanese elderly.

    PubMed

    Wang, Jui-Line; Shaw, Ning-Sing; Yeh, Hsiang-Yu; Kao, Mei-Ding

    2005-01-01

    The average dietary intake of magnesium is below recommended dietary allowances in many affluent Western countries. Prolonged low magnesium intake tends to result in hypomagnesaemia which might increase the risk of chronic diseases in elderly people. A national population-based cross-sectional nutrition survey, the Elderly Nutrition and Health Survey in Taiwan (1999-2000), was used to investigate the magnesium status and association with diabetes in the Taiwanese elderly. Dietary magnesium intake was based on 24-hour dietary recalls. Blood biochemical parameters including plasma magnesium and blood glucose were also measured. Average magnesium intake was 250 mg in men and 216 mg in women, which is equivalent to 68-70% of relevant Taiwanese Dietary Reference Intakes. The mean plasma magnesium concentration was 0.903 mmol/L in men and 0.906 mmol/L in women. The prevalence of a plasma magnesium level of <0.7 mmol/L was 0.7-0.9% in the elderly, and that of <0.8 mmol/L was 8.0-9.1%. Elderly vegans had a significantly lower magnesium intake than ovo-lacto vegetarians and non-vegetarians. Diabetic men and women had significantly higher blood glucose levels than non-diabetics. The risk of diabetes was elevated 3.25 times at plasma magnesium levels<0.863 mmol/L. There was an inverse association between plasma magnesium concentration and the prevalence of diabetes. However, no association was found between diabetes and low dietary magnesium. Taiwanese elderly persons had suboptimal levels of dietary magnesium intake, which although may be sufficient to avoid overt magnesium deficiency, may not be sufficient to reduce the risk of diabetes in the elderly. Further prospective study is required to help explain the differential results between dietary and plasma magnesium levels. PMID:16169838

  11. Magnesium substitution in the structure of orthopedic nanoparticles: A comparison between amorphous magnesium phosphates, calcium magnesium phosphates, and hydroxyapatites.

    PubMed

    Nabiyouni, Maryam; Ren, Yufu; Bhaduri, Sarit B

    2015-01-01

    As biocompatible materials, magnesium phosphates have received a lot of attention for orthopedic applications. During the last decade multiple studies have shown advantages for magnesium phosphate such as lack of cytotoxicity, biocompatibility, strong mechanical properties, and high biodegradability. The present study investigates the role of Mg(+2) and Ca(+2) ions in the structure of magnesium phosphate and calcium phosphate nanoparticles. To directly compare the effect of Mg(+2) and Ca(+2) ions on structure of nanoparticles and their biological behavior, three groups of nanoparticles including amorphous magnesium phosphates (AMPs) which release Mg(+2), calcium magnesium phosphates (CMPs) which release Mg(+2) and Ca(+2), and hydroxyapatites (HAs) which release Ca(+2) were studied. SEM, TEM, XRD, and FTIR were used to evaluate the morphology, crystallinity, and chemical properties of the particles. AMP particles were homogeneous nanospheres, whereas CMPs were combinations of heterogeneous nanorods and nanospheres, and HAs which contained heterogeneous nanosphere particles. Cell compatibility was monitored in all groups to determine the cytotoxicity effect of particles on studied MC3T3-E1 preosteoblasts. AMPs showed significantly higher attachment rate than the HAs after 1 day and both AMPs and CMPs showed significantly higher proliferation rate when compared to HAs after 7days. Gene expression level of osteoblastic markers ALP, COL I, OCN, OPN, RUNX2 were monitored and they were normalized to GAPDH housekeeping gene. Beta actin expression level was monitored as the second housekeeping gene to confirm the accuracy of results. In general, AMPs and CMPs showed higher expression level of osteoblastic genes after 7 days which can further confirm the stimulating role of Mg(+2) and Ca(+2) ions in increasing the proliferation rate, differentiation, and mineralization of MC3T3-E1 preosteoblasts. PMID:25953534

  12. Direct Hydrogenation Magnesium Boride to Magnesium Borohydride: Demonstration of >11 Weight Percent Reversible Hydrogen Storage

    SciTech Connect

    Severa, Godwin; Ronnebro, Ewa; Jensen, Craig M.

    2010-11-16

    We here for the first time demonstrate direct hydrogenation of magnesium boride, MgB2, to magnesium borohydride, Mg(BH4)2 at 900 bar H2-pressures and 400°C. Upon 14.8wt% hydrogen release, the end-decomposition product of Mg(BH4)2 is MgB2, thus, this is a unique reversible path here obtaining >11wt% H2 which implies promise for a fully reversible hydrogen storage material.

  13. 21 CFR 184.1425 - Magnesium carbonate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Magnesium carbonate. 184.1425 Section 184.1425 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) DIRECT FOOD SUBSTANCES AFFIRMED AS GENERALLY RECOGNIZED AS SAFE Listing of Specific Substances Affirmed as GRAS §...

  14. 21 CFR 184.1443 - Magnesium sulfate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Magnesium sulfate. 184.1443 Section 184.1443 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) DIRECT FOOD SUBSTANCES AFFIRMED AS GENERALLY RECOGNIZED AS SAFE Listing of Specific Substances Affirmed as GRAS...

  15. 21 CFR 184.1426 - Magnesium chloride.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Magnesium chloride. 184.1426 Section 184.1426 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) DIRECT FOOD SUBSTANCES AFFIRMED AS GENERALLY RECOGNIZED AS SAFE Listing of Specific Substances Affirmed as GRAS...

  16. 21 CFR 184.1428 - Magnesium hydroxide.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Magnesium hydroxide. 184.1428 Section 184.1428 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) DIRECT FOOD SUBSTANCES AFFIRMED AS GENERALLY RECOGNIZED AS SAFE Listing of Specific Substances Affirmed as GRAS §...

  17. 21 CFR 184.1431 - Magnesium oxide.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Magnesium oxide. 184.1431 Section 184.1431 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) DIRECT FOOD SUBSTANCES AFFIRMED AS GENERALLY RECOGNIZED AS SAFE Listing of Specific Substances Affirmed as GRAS...

  18. 21 CFR 184.1426 - Magnesium chloride.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Magnesium chloride. 184.1426 Section 184.1426 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) DIRECT FOOD SUBSTANCES AFFIRMED AS GENERALLY RECOGNIZED AS SAFE Listing of Specific Substances Affirmed as GRAS...

  19. 21 CFR 201.71 - Magnesium labeling.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) DRUGS: GENERAL... introduced or initially delivered for introduction into interstate commerce after the following dates is... over-the-counter (OTC) drug products intended for oral ingestion shall contain the magnesium...

  20. 21 CFR 201.71 - Magnesium labeling.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) DRUGS: GENERAL... introduced or initially delivered for introduction into interstate commerce after the following dates is... over-the-counter (OTC) drug products intended for oral ingestion shall contain the magnesium...

  1. 21 CFR 201.71 - Magnesium labeling.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) DRUGS: GENERAL... introduced or initially delivered for introduction into interstate commerce after the following dates is... over-the-counter (OTC) drug products intended for oral ingestion shall contain the magnesium...

  2. 21 CFR 184.1428 - Magnesium hydroxide.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Magnesium hydroxide. 184.1428 Section 184.1428 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) DIRECT FOOD SUBSTANCES AFFIRMED AS GENERALLY RECOGNIZED AS SAFE Listing of Specific Substances Affirmed as GRAS §...

  3. 21 CFR 184.1426 - Magnesium chloride.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Magnesium chloride. 184.1426 Section 184.1426 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) DIRECT FOOD SUBSTANCES AFFIRMED AS GENERALLY RECOGNIZED AS SAFE Listing of Specific Substances Affirmed as GRAS...

  4. 21 CFR 184.1431 - Magnesium oxide.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Magnesium oxide. 184.1431 Section 184.1431 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) DIRECT FOOD SUBSTANCES AFFIRMED AS GENERALLY RECOGNIZED AS SAFE Listing of Specific Substances Affirmed as GRAS...

  5. 21 CFR 184.1443 - Magnesium sulfate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Magnesium sulfate. 184.1443 Section 184.1443 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) DIRECT FOOD SUBSTANCES AFFIRMED AS GENERALLY RECOGNIZED AS SAFE Listing of Specific Substances Affirmed as GRAS...

  6. Calcium, magnesium, and potassium in food

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The biochemical and physiological functions and consequences of deficient intakes, which show the nutritional importance of calcium, magnesium and potassium for humans, are reviewed. The dietary recommendations and food sources for these essential mineral elements for humans are presented. Factors t...

  7. Preparation of thorium magnesium-zinc reduction

    NASA Technical Reports Server (NTRS)

    Hariharan, A. V.; Knighton, J. B.; Steunenberg, R. K.

    1969-01-01

    Magnesium-zinc reduction of thorium dioxide is used for the preparation of thorium metal. Potential economic advantages of this technique include use of relatively inexpensive reagents for the metal and flux phases, and production of metal of acceptable quality in good yield.

  8. Effect of magnesium ion on human osteoblast activity

    PubMed Central

    He, L.Y.; Zhang, X.M.; Liu, B.; Tian, Y.; Ma, W.H.

    2016-01-01

    Magnesium, a promising biodegradable metal, has been reported in several studies to increase bone formation. Although there is some information regarding the concentrations of magnesium ions that affect bone remodeling at a cellular level, little is known about the effect of magnesium ions on cell gap junctions. Therefore, this study aimed to systematically investigate the effects of different concentrations of magnesium on bone cells, and further evaluate its effect on gap junctions of osteoblasts. Cultures of normal human osteoblasts were treated with magnesium ions at concentrations of 1, 2 and 3 mM, for 24, 48 and 72 h. The effects of magnesium ions on viability and function of normal human osteoblasts and on gap junction intercellular communication (GJIC) in osteoblasts were investigated. Magnesium ions induced significant (P<0.05) increases in cell viability, alkaline phosphate activity and osteocalcin levels of human osteoblasts. These stimulatory actions were positively associated with the concentration of magnesium and the time of exposure. Furthermore, the GJIC of osteoblasts was significantly promoted by magnesium ions. In conclusion, this study demonstrated that magnesium ions induced the activity of osteoblasts by enhancing GJIC between cells, and influenced bone formation. These findings may contribute to a better understanding of the influence of magnesium on bone remodeling and to the advance of its application in clinical practice. PMID:27383121

  9. Effect of magnesium deficiency on erythrocyte aging in rats.

    PubMed Central

    Elin, R. J.; Utter, A.; Tan, H. K.; Corash, L.

    1980-01-01

    Rats placed on a magnesium-deficient diet show decreased erythrocyte magnesium concentration, shortened erythrocyte survival, and erythrocyte membrane ultrastructure defects and become progressively anemic. Whether these pathologic processes are due to abnormal erythropoiesis or occur in the peripheral circulation is unknown. In the present study, magnesium and hemoglobin concentrations, reticulocyte count, erythrocyte pyrophosphatase, and pyruvate kinase activities were determined at weekly intervals for 6 weeks in whole blood and age-dependent erythrocyte fractions isolated from inbred Fisher rats fed a diet deficient in magnesium or the same diet with added magnesium. Freeze-fracture electron microscopic examinations were performed on age-dependent erythrocyte fractions to evaluate the membrane defect. The youngest red cells from magnesium-deficient rats were similar to those of control animals with respect to erythrocyte magnesium concentrations, pyrophosphatase activities, and membrane morphology. The older erythrocyte fractions from magnesium-deficient rats showed significant decreases in magnesium concentrations, pyrophosphatase activity, and the presence of membrane abnormalities. Thus, new erythrocytes produced in magnesium-deficient rats appear to be normal but rapidly develop biochemical and morphologic abnormalities with aging in a magnesium-deficient plasma environment. Images Figure 1 PMID:6106388

  10. Assessment of magnesium status for diagnosis and therapy.

    PubMed

    Elin, Ronald J

    2010-12-01

    Magnesium is an essential element needed for health. Even though only 1% of the total body magnesium is present in blood, the serum magnesium concentration (SMC) is the predominant test used by medicine to assess magnesium status in patients. The traditional method to establish a reference interval for the SMC is flawed by the large number of "normal" individuals who have a subtle chronic negative magnesium balance due to a significant decrease in magnesium intake over the past century. Evidence-based medicine should be used to establish the appropriate lower limit of the reference interval for health and I recommend 0.85 mmol/L based on current literature. The decrease in magnesium in the diet has led to chronic latent magnesium deficiency in a large number of people since their SMC is still within the reference interval due to primarily the bone magnesium supplementing the SMC. These individuals need adjustment of their diet or magnesium supplementation to achieve a normal magnesium status for health. PMID:20736141

  11. Nanostructured magnesium has fewer detrimental effects on osteoblast function

    PubMed Central

    Weng, Lucy; Webster, Thomas J

    2013-01-01

    Efforts have been made recently to implement nanoscale surface features on magnesium, a biodegradable metal, to increase bone formation. Compared with normal magnesium, nanostructured magnesium has unique characteristics, including increased grain boundary properties, surface to volume ratio, surface roughness, and surface energy, which may influence the initial adsorption of proteins known to promote the function of osteoblasts (bone-forming cells). Previous studies have shown that one way to increase nanosurface roughness on magnesium is to soak the metal in NaOH. However, it has not been determined if degradation of magnesium is altered by creating nanoscale features on its surface to influence osteoblast density. The aim of the present in vitro study was to determine the influence of degradation of nanostructured magnesium, created by soaking in NaOH, on osteoblast density. Our results showed a less detrimental effect of magnesium degradation on osteoblast density when magnesium was treated with NaOH to create nanoscale surface features. The detrimental degradation products of magnesium are of significant concern when considering use of magnesium as an orthopedic implant material, and this study identified a surface treatment, ie, soaking in NaOH to create nanoscale features for magnesium that can improve its use in numerous orthopedic applications. PMID:23674891

  12. Fabrication and characterization of AZ91/CNT magnesium matrix composites

    NASA Astrophysics Data System (ADS)

    Park, Yong-Ha; Park, Yong-Ho; Park, Ik-Min; Oak, Jeong-jung; Kimura, Hisamichi; Cho, Kyung-Mox

    2008-12-01

    Carbon Nano Tube (CNT) reinforced AZ91 metal matrix composites (MMC) were fabricated by the squeeze infiltrated method. Properties of magnesium alloys have been improved by impurity reduction, surface treatment and alloy design, and thus the usage for the magnesium alloys has been extended recently. However there still remain barriers for the adaption of magnesium alloys for engineering materials. In this study, we report light-weight, high strength heat resistant magnesium matrix composites. Microstructural study and tensile test were performed for the squeeze infiltrated magnesium matrix composites. The wear properties were characterized and the possibility for the application to automotive power train and engine parts was investigated. It was found that the squeeze infiltration technique is a proper method to fabricate magnesium matrix composites reducing casting defects such as pores and matrix/reinforcement interface separation etc. Improved tensile and mechanical properties were obtained with CNT reinforcing magnesium alloys

  13. Assessment of the magnesium primary production technology. Final report

    SciTech Connect

    Flemings, M.C.; Kenney, G.B.; Sadoway, D.R.; Clark, J.P.; Szekely, J.

    1981-02-01

    At current production levels, direct energy savings achievable in primary magnesium production are 1.2 milliquads of energy per annum. Were magnesium to penetrate the automotive market to an average level of 50 pounds per vehicle, the resultant energy savings at the production stage would be somewhat larger, but the resulting savings in gasoline would conserve an estimated 325 milliquads of energy per year. The principal barrier to more widespread use of magnesium in the immediate future is its price. A price reduction of magnesium of 10% would lead to widespread conversion of aluminum die and permanent mold castings to magnesium. This report addresses the technology of electrolytic and thermic magnesium production and the economics of expanded magnesium production and use.

  14. Final report on the safety assessment of aluminum silicate, calcium silicate, magnesium aluminum silicate, magnesium silicate, magnesium trisilicate, sodium magnesium silicate, zirconium silicate, attapulgite, bentonite, Fuller's earth, hectorite, kaolin, lithium magnesium silicate, lithium magnesium sodium silicate, montmorillonite, pyrophyllite, and zeolite.

    PubMed

    Elmore, Amy R

    2003-01-01

    This report reviews the safety of Aluminum, Calcium, Lithium Magnesium, Lithium Magnesium Sodium, Magnesium Aluminum, Magnesium, Sodium Magnesium, and Zirconium Silicates, Magnesium Trisilicate, Attapulgite, Bentonite, Fuller's Earth, Hectorite, Kaolin, Montmorillonite, Pyrophyllite, and Zeolite as used in cosmetic formulations. The common aspect of all these claylike ingredients is that they contain silicon, oxygen, and one or more metals. Many silicates occur naturally and are mined; yet others are produced synthetically. Typical cosmetic uses of silicates include abrasive, opacifying agent, viscosity-increasing agent, anticaking agent, emulsion stabilizer, binder, and suspending agent. Clay silicates (silicates containing water in their structure) primarily function as adsorbents, opacifiers, and viscosity-increasing agents. Pyrophyllite is also used as a colorant. The International Agency for Research on Cancer has ruled Attapulgite fibers >5 microm as possibly carcinogenic to humans, but fibers <5 microm were not classified as to their carcinogenicity to humans. Likewise, Clinoptilolite, Phillipsite, Mordenite, Nonfibrous Japanese Zeolite, and synthetic Zeolites were not classified as to their carcinogenicity to humans. These ingredients are not significantly toxic in oral acute or short-term oral or parenteral toxicity studies in animals. Inhalation toxicity, however, is readily demonstrated in animals. Particle size, fibrogenicity, concentration, and mineral composition had the greatest effect on toxicity. Larger particle size and longer and wider fibers cause more adverse effects. Magnesium Aluminum Silicate was a weak primary skin irritant in rabbits and had no cumulative skin irritation in guinea pigs. No gross effects were reported in any of these studies. Sodium Magnesium Silicate had no primary skin irritation in rabbits and had no cumulative skin irritation in guinea pigs. Hectorite was nonirritating to the skin of rabbits in a Draize primary skin

  15. Ascorbic acid, calcium, phosphorus and magnesium intake variations: effects on calcium, phosphorus and magnesium utilization by human adults

    SciTech Connect

    Kies, C.; Brennan, M.A.; Parks, S.K.; Stauffer, D.J.; Wang, H.Y.; Young, S.F.; Fox, H.M.

    1986-03-01

    The objective of the study was to determine the effects of feeding two levels of ascorbic acid, calcium, phosphorus, magnesium and ascorbic acid on the apparent utilization of calcium, phosphorus and magnesium by healthy, human adult subjects. During 4 randomly-arranged experimental periods of 7 days each, a laboratory-controlled diet alone or with supplements of ascorbic acid, dicalcium phosphate or magnesium oxide was fed to the 18 subjects. Results indicated that ascorbic acid supplementation tended to reduce urinary phosphorus loss and to slightly increase fecal phosphorus loss so that overall phosphorus balances became more positive. Conversely, under these conditions, urinary calcium losses were little affected but fecal calcium losses were increased resulting in an overall decrease in calcium balance with ascorbic acid supplementation. Ascorbic acid supplementation resulted in decreased urine and fecal losses of magnesium and more positive magnesium balances. Magnesium supplementation resulted in more positive calcium and phosphorus balances as did calcium phosphate supplementation on magnesium balance.

  16. Transport of Magnesium by a Bacterial Nramp-Related Gene

    PubMed Central

    Rodionov, Dmitry A.; Freedman, Benjamin G.; Senger, Ryan S.; Winkler, Wade C.

    2014-01-01

    Magnesium is an essential divalent metal that serves many cellular functions. While most divalent cations are maintained at relatively low intracellular concentrations, magnesium is maintained at a higher level (∼0.5–2.0 mM). Three families of transport proteins were previously identified for magnesium import: CorA, MgtE, and MgtA/MgtB P-type ATPases. In the current study, we find that expression of a bacterial protein unrelated to these transporters can fully restore growth to a bacterial mutant that lacks known magnesium transporters, suggesting it is a new importer for magnesium. We demonstrate that this transport activity is likely to be specific rather than resulting from substrate promiscuity because the proteins are incapable of manganese import. This magnesium transport protein is distantly related to the Nramp family of proteins, which have been shown to transport divalent cations but have never been shown to recognize magnesium. We also find gene expression of the new magnesium transporter to be controlled by a magnesium-sensing riboswitch. Importantly, we find additional examples of riboswitch-regulated homologues, suggesting that they are a frequent occurrence in bacteria. Therefore, our aggregate data discover a new and perhaps broadly important path for magnesium import and highlight how identification of riboswitch RNAs can help shed light on new, and sometimes unexpected, functions of their downstream genes. PMID:24968120

  17. Transport of magnesium by a bacterial Nramp-related gene.

    PubMed

    Shin, Jung-Ho; Wakeman, Catherine A; Goodson, Jonathan R; Rodionov, Dmitry A; Freedman, Benjamin G; Senger, Ryan S; Winkler, Wade C

    2014-06-01

    Magnesium is an essential divalent metal that serves many cellular functions. While most divalent cations are maintained at relatively low intracellular concentrations, magnesium is maintained at a higher level (∼0.5-2.0 mM). Three families of transport proteins were previously identified for magnesium import: CorA, MgtE, and MgtA/MgtB P-type ATPases. In the current study, we find that expression of a bacterial protein unrelated to these transporters can fully restore growth to a bacterial mutant that lacks known magnesium transporters, suggesting it is a new importer for magnesium. We demonstrate that this transport activity is likely to be specific rather than resulting from substrate promiscuity because the proteins are incapable of manganese import. This magnesium transport protein is distantly related to the Nramp family of proteins, which have been shown to transport divalent cations but have never been shown to recognize magnesium. We also find gene expression of the new magnesium transporter to be controlled by a magnesium-sensing riboswitch. Importantly, we find additional examples of riboswitch-regulated homologues, suggesting that they are a frequent occurrence in bacteria. Therefore, our aggregate data discover a new and perhaps broadly important path for magnesium import and highlight how identification of riboswitch RNAs can help shed light on new, and sometimes unexpected, functions of their downstream genes. PMID:24968120

  18. Laser-induced magnesium production from magnesium oxide using reducing agents

    SciTech Connect

    Mohamed, M. S.; Yabe, T.; Baasandash, C.; Sato, Y.; Mori, Y.; Shi-Hua, Liao; Sato, H.; Uchida, S.

    2008-12-01

    Experiments for laser induced production of magnesium (Mg) from magnesium oxide (MgO) using reducing agents (R) were conducted. In these experiments, continuous wave CO{sub 2} focused laser is focused on a mixture of magnesium oxide and reducing agent. High power density of focused laser leads to high temperature and the reduction reaction resulting in Mg production. The resultant vapor is collected on a copper plate and analyzed in terms of magnesium deposition efficiency. Deposition efficiencies with various reducing agents such as Zr, C, and Si have been measured to be 60, 9.2, and 12.1 mg/kJ respectively. An excess addition of reducing agent over their corresponding reaction stoichiometric amounts is found to be optimum condition for the most of performed laser induced reactions. In addition, utilizing solar-pumped laser in Mg production with reducing agent will reduce CO{sub 2} emission and produce magnesium with high-energy efficiency and large throughput.

  19. Thermal conductivities of nanostructured magnesium oxide coatings deposited on magnesium alloys by plasma electrolytic oxidation.

    PubMed

    Shen, Xinwei; Nie, Xueyuan; Hu, Henry

    2014-10-01

    The resistances of magnesium alloys to wear, friction and corrosion can be effectively improved by depositing coatings on their surfaces. However, the coatings can also reduce the heat transfer from the coated components to the surroundings (e.g., coated cylinder bores for internal combustion of engine blocks). In this paper, nanostructured magnesium oxides were produced by plasma electrolytic oxidation (PEO) process on the magnesium alloy AJ62 under different current densities. The guarded comparative heat flow method was adopted to measure the thermal conductivities of such coatings which possess gradient nanoscale grain sizes. The aim of the paper is to explore how the current density in the PEO process affects the thermal conductivity of the nanostructured magnesium coatings. The experimental results show that, as the current density rises from 4 to 20 A/mm2, the thermal conductivity has a slight increase from 0.94 to 1.21 W/m x K, which is significantly smaller than that of the corresponding bulk magnesium oxide materials (29.4 W/m x K). This mostly attributed to the variation of the nanoscale grain sizes of the PEO coatings. PMID:25942897

  20. The Corrosion of Magnesium and of the Magnesium Aluminum Alloys Containing Manganese

    NASA Technical Reports Server (NTRS)

    Boyer, J A

    1927-01-01

    The extensive use of magnesium and its alloys in aircraft has been seriously handicapped by the uncertainties surrounding their resistance to corrosion. This problem has been given intense study by the American Magnesium Corporation and at the request of the Subcommittee on Materials for Aircraft of the National Advisory Committee for Aeronautics this report was prepared on the corrosion of magnesium. The tentative conclusions drawn from the experimental facts of this investigation are as follows: the overvoltage of pure magnesium is quite high. On immersion in salt water the metal corrodes with the liberation of hydrogen until the film of corrosion product lowers the potential to a critical value. When the potential reaches this value it no longer exceeds the theoretical hydrogen potential plus the overvoltage of the metal. Rapid corrosion consequently ceases. When aluminum is added, especially when in large amounts, the overvoltage is decreased and hydrogen plates out at a much lower potential than with pure magnesium. The addition of small amount of manganese raises the overvoltage back to practically that of pure metal, and the film is again negative.

  1. Chemically prepared lead magnesium niobate dielectrics

    SciTech Connect

    Tuttle, B.A.; Voigt, J.A.; Sipola, D.L.; Olson, W.R.; Goy, D.M.

    1998-11-01

    A chemical solution powder synthesis technique has been developed that produces first, uniform powders of lead magnesium niobate (PMN) with 60 to 80 nm crystallite size. The synthesis technique was based on the dissolution of lead acetate and alkoxide precursors in acetic acid followed by precipitation with oxalic acid/propanol solutions. Lead magnesium niobate ceramics fabricated from these chemically derived powders had smaller, more uniform grain size and higher dielectric constants than ceramics fabricated from mixed oxide powders that were processed under similar thermal conditions. Chem-prep PMN dielectrics with peak dielectric constants greater than 22,000 and polarizations in excess of 29 {micro}C/cm{sup 2} were obtained for 1,100 C firing treatments. Substantial decreases in dielectric constant and polarization were measured for chemically prepared PMN ceramics fired at lower temperatures, consistent with previous work on mixed oxide materials.

  2. Lead magnesium niobate actuator for micropositioning

    DOEpatents

    Swift, C.D.; Bergum, J.W.

    1994-10-25

    An improved lead magnesium niobate actuator is disclosed comprising a cylindrical lead magnesium niobate crystal stack mounted in a cylindrical casing wherein a bias means, such as one or more belleville washers, is located between one end of the crystal stack and a partially closed end of the casing; and adjustment means are provided which bear against the opposite end of the crystal stack, whereby an adjustable compressive force is constantly applied against the crystal stack, whether the crystal stack is actuated in an extended position, or is in an unactuated contracted position. In a preferred embodiment, cooling ports are provided for the circulation of coolant in the actuator to cool the crystal stack, and provision is made for removal and replacement of the crystal stack without disconnecting the actuator from the external device being actuated. 3 figs.

  3. Lead magnesium niobate actuator for micropositioning

    DOEpatents

    Swift, Charles D.; Bergum, John W.

    1994-01-01

    An improved lead magnesium niobate actuator is disclosed comprising a cylindrical lead magnesium niobate crystal stack mounted in a cylindrical casing wherein a bias means, such as one or more belleville washers, is located between one end of the crystal stack and a partially closed end of the casing; and adjustment means are provided which bear against the opposite end of the crystal stack, whereby an adjustable compressive force is constantly applied against the crystal stack, whether the crystal stack is actuated in an extended position, or is in an unactuated contracted position. In a preferred embodiment, cooling ports are provided for the circulation of coolant in the actuator to cool the crystal stack, and provision is made for removal and replacement of the crystal stack without disconnecting the actuator from the external device being actuated.

  4. Search for Magnesium Diboride like Binary Superconductors

    NASA Astrophysics Data System (ADS)

    Isikaku-Ironkwe, O. Paul

    2008-03-01

    Efforts to create compounds iso-electronic and iso-structural with magnesium diboride and also superconducting have so far met with limited success. Doping the Mg-site or the B-site have also not yielded higher transition temperatures. They have either been non-superconducting or have lower transition temperatures, Tc. Searching for magnesium diboride-like compounds using the electronegativity of MgB2 (1.7333) has yielded a rich family of potential superconductors. The search has been facilitated using the recently designed ElectroNegativity Spectrum Maps [ENSMaps] of binary systems AxBy. Here we display the potential families. Using the relationship between Tc and atomic mass, we estimate the transition temperatures of the most likely MgB2-like binary superconductors. We also suggest materials that can be doped to give an electronegativity of 1.7333.

  5. Magnesium diboride films on iron substrates

    NASA Astrophysics Data System (ADS)

    Auinger, Michael; Gritzner, Gerhard

    2008-01-01

    The fabrication of superconducting magnesium diboride films on iron substrates with and without buffer layers (Y2O3 stabilized ZrO2 and Al2O3) is reported. Both the boron and the buffer layers were applied via screen-printing. Conversion into the superconducting MgB2 was carried out via vapour transport under Ar/H2 at temperatures around 850 °C in a sealed aluminium oxide crucible together with magnesium as a source material. X-ray diffraction was used to identify the phases formed during the preparation procedure. Smooth films with high critical temperatures of up to 38 K and a narrow transition range of only 1 K were obtained on Y2O3 stabilized ZrO2 or Al2O3 buffered iron substrates.

  6. Enhancements in Magnesium Die Casting Impact Properties

    SciTech Connect

    David Schwam; John F. Wallace; Yulong Zhu; Srinath Viswanathan; Shafik Iskander

    2000-06-30

    The need to produce lighter components in transportation equipment is the main driver in the increasing demand for magnesium castings. In many automotive applications, components can be made of magnesium or aluminum. While being lighter, often times the magnesium parts have lower impact and fatigue properties than the aluminum. The main objective of this study was to identify potential improvements in the impact resistance of magnesium alloys. The most common magnesium alloys in automotive applications are AZ91D, AM50 and AM60. Accordingly, these alloys were selected as the main candidates for the study. Experimental quantities of these alloys were melted in an electrical furnace under a protective atmosphere comprising sulfur hexafluoride, carbon dioxide and dry air. The alloys were cast both in a permanent mold and in a UBE 315 Ton squeeze caster. Extensive evaluation of tensile, impact and fatigue properties was conducted at CWRU on permanent mold and squeeze cast test bars of AZ91, AM60 and AM50. Ultimate tensile strength values between 20ksi and 30ksi were obtained. The respective elongations varied between 25 and 115. the Charpy V-notch impact strength varied between 1.6 ft-lb and 5 ft-lb depending on the alloy and processing conditions. Preliminary bending fatigue evaluation indicates a fatigue limit of 11-12 ksi for AM50 and AM60. This is about 0.4 of the UTS, typical for these alloys. The microstructures of the cast specimens were investigated with optical and scanning electron microscopy. Concomitantly, a study of the fracture toughness in AM60 was conducted at ORNL as part of the study. The results are in line with values published in the literature and are representative of current state of the art in casting magnesium alloys. The experimental results confirm the strong relationship between aluminum content of the alloys and the mechanical properties, in particular the impact strength and the elongation. As the aluminum content increases from about 5

  7. Lithium-aluminum-magnesium electrode composition

    DOEpatents

    Melendres, Carlos A.; Siegel, Stanley

    1978-01-01

    A negative electrode composition is presented for use in a secondary, high-temperature electrochemical cell. The cell also includes a molten salt electrolyte of alkali metal halides or alkaline earth metal halides and a positive electrode including a chalcogen or a metal chalcogenide as the active electrode material. The negative electrode composition includes up to 50 atom percent lithium as the active electrode constituent and a magnesium-aluminum alloy as a structural matrix. Various binary and ternary intermetallic phases of lithium, magnesium, and aluminum are formed but the electrode composition in both its charged and discharged state remains substantially free of the alpha lithium-aluminum phase and exhibits good structural integrity.

  8. Silica urolithiasis without magnesium trisilicate intake.

    PubMed

    Ichiyanagi, O; Sasagawa, I; Adachi, Y; Suzuki, H; Kubota, Y; Nakada, T

    1998-10-01

    Two cases of silica stones, without previous oral intake of magnesium trisilicate, are reported. A 64-year-old Japanese woman had bilateral renal stones. Infrared spectrophotoscopy revealed that one of the fragments consisted of silicate and the others consisted of calcium oxalate. A 75-year-old woman had right renal stones. The composition of 1 stone was a mixture of silicate and unspecified matrices. Silicate urolithiasis may not necessarily be related to oral intake of silicate-containing antacids. PMID:9792982

  9. Sea water magnesium fuel cell power supply

    NASA Astrophysics Data System (ADS)

    Hahn, Robert; Mainert, Jan; Glaw, Fabian; Lang, K.-D.

    2015-08-01

    An environmentally friendly magnesium fuel cell system using seawater electrolyte and atmospheric oxygen was tested under practical considerations for use as maritime power supply. The hydrogen rate and therefore the power density of the system were increased by a factor of two by using hydrogen evolution cathodes with a gas separation membrane instead of submerged cathodes without gas separation. Commercial magnesium AZ31 rolled sheet anodes can be dissolved in seawater for hydrogen production, down to a thickness below 100 μm thickness, resulting in hydrogen generation efficiency of the anode of over 80%. A practical specific energy/energy density of the alloy of more than 1200 Wh/kg/3000 Wh/l was achieved when coupled to a fuel cell with atmospheric air breathing cathode. The performance of several AZ31 alloy anodes was tested as well as the influence of temperature, electrolyte concentration and anode - cathode separation. The excess hydrogen produced by the magnesium hydrogen evolving cell, due to the negative difference effect, is proportional to the cell current in case of the AZ31 alloys, which simplifies system control considerably. Stable long-term operation of the system was demonstrated at low pressures which can be maintained in an open-seawater-submerged hydrogen generator.

  10. Magnesium Catalysis for the Hydroboration of Carbodiimides.

    PubMed

    Weetman, Catherine; Hill, Michael S; Mahon, Mary F

    2016-05-17

    A β-diketiminato magnesium alkyl complex, [CH{C(Me)NDipp}2 }MgnBu] (Dipp=2,6-iPr2 C6 H3 ), was shown to be an effective pre-catalyst for the first reported catalytic hydroboration of alkyl- and aryl-substituted carbodiimides with pinacol borane (HBpin). The catalytic reactions proceed under mild conditions to afford the corresponding N-borylated formamidine compounds in good yields. The reactions were observed to proceed through the intermediacy of magnesium amidinate and formamidinatoborate intermediates and an example of one of these latter species has been structurally characterised by an X-ray diffraction analysis. Crucially, no formation of the N-boryl formamidine products was observed in the absence of additional equivalents of the carbodiimide and HBpin substrates. This observation, supported by the evolution of a sigmoidal kinetic profile for the hydroboration of dicyclohexylcarbodiimide, has been rationalised as the consequence of an allosteric effect of the pinacol borane and carbodiimide on the magnesium formamidinatoborate intermediates. PMID:27072429

  11. [Magnesium level in human organism during 105-day isolation].

    PubMed

    Piruzian, L A; Protasova, O V; Maksimova, I A; Morukov, B V; Protasov, S V; Ushakov, I B

    2012-01-01

    Total and ionized magnesium in blood serum and in daily urine were determined before (baseline values) and on days 30, 60 and 105 of the experiment with 105-d isolation and confinement (Mars-105)/ Magnesium in hair was investigated before (baseline values) and on day-105 of the experiment. The investigations were performed using atomic emission spectrometry with inductively coupled argon plasma. Changes in magnesium were most significant over the initial 30 days in the experiment. Reduction of serum magnesium was accounted for by the fall in the ionized fraction. In organism magnesium is controlled by the ion-regulatory function of the kidney and varies with individuals. Levels of ionized magnesium in blood serum and excreted with daily urine can serve as indicators of stress resistivity . PMID:23074947

  12. Adsorption of β-carotene on modified magnesium silicate

    NASA Astrophysics Data System (ADS)

    Sun, Shanshan; Guo, Ning; Fu, Yongfeng

    2016-02-01

    Modified flocculation magnesium silicate is prepared by a hydrothermal process at 120°C for 18 h after adding Al2(SO4)3 into the magnesium silicate gel. Compared with standard magnesium silicate with 328.116 m2 g-1 surface area, this modified magnesium silicate has a bigger BET surface area of 536.803 m2 g-1 and a lower interlayer water content. Modified magnesium silicate exhibits high β-carotene adsorption with a maximum adsorption capacity of 364.96 mg g-1. It is shown that when suspended in organic solvent, this material can be used effectively for carotenoid separation. Furthermore, our results suggest that modified magnesium silicate may be a promising candidate as an absorbent in the decoloring of oil.

  13. Magnesium global development: Outcomes from the TMS 2007 annual meeting

    NASA Astrophysics Data System (ADS)

    Beals, Randy S.; Tissington, Cam; Zhang, Xinmin; Kainer, Karl; Petrillo, Joe; Verbrugge, Mark; Pekguleryuz, Mihriban

    2007-08-01

    The magnesium industry is experiencing dramatic growth, due in part to the demands of the automotive industry to improve fuel economy and emissions. As a result, the TMS annual magnesium symposium is one of the fastest-growing subject areas at TMS. In addition, TMS is recognized as the global light metals community’s preeminent forum for the presentation of magnesium science and technological issues. As a focal point of the 2007 TMS Annual Meeting in Orlando, Florida, the TMS Magnesium Committee held its first plenary session with expert representatives from around the world. In order to address the surge in magnesium technology in recent years, the TMS Magnesium Globalization plenary session included a variety of subjects that ranged from economic to technical.

  14. Effects of magnesium deficiency--more than skin deep.

    PubMed

    Chandrasekaran, Navin Chandrakanth; Weir, Christopher; Alfraji, Sumaya; Grice, Jeff; Roberts, Michael S; Barnard, Ross T

    2014-10-01

    Dead Sea and magnesium salt therapy are two of the oldest forms of treatment for skin disease and several other disorders, supported by a body of largely anecdotal evidence. In this paper we review possible pathways for penetration of magnesium ions through the epidermis to reach the circulation, in turn replenishing cellular magnesium levels. We also discuss mechanisms for intercellular movement of magnesium ions and possible mechanisms for the interaction between magnesium ions and inflammatory mediators. Upon addition of magnesium ions in vitro, the expression of inflammatory mediators such as tumour necrosis factor α (TNFα) and nuclear factor κβ (NFκβ) is down regulated. Dysregulation of these and other inflammatory mediators has been linked to several inflammatory disorders, including asthma, arthritis, atherosclerosis and neuroinflammation. PMID:24928863

  15. Reversible Dehydrogenation of Magnesium Borohydride to Magnesium Triborane in the Solid State Under Moderate Conditions

    SciTech Connect

    Chong, Marina; Karkamkar, Abhijeet J.; Autrey, Thomas; Orimo, Shin-ichi; Jalisatgi, Satish; Jensen, Craig M.

    2011-02-17

    Thermal decomposition of magnesium borohydride, Mg(BH4)2, in the solid state was studied by a combination of PCT, TGA/MS and NMR spectroscopy. Dehydrogenation of Mg(BH4)2 at 200 °C, results in the highly selective formation of magnesium triborane, Mg(B3H8)2. This process is reversible at 250 °C under 120 atm H2. Dehydrogenation at higher temperature, > 300 °C, produces a complex mixture of polyborane species. Solution phase 11B NMR spectra of the hydrolyzed decomposition products reveals the formation of the B3H8 anion, boric acid from hydrolysis of the unstable polyboranes (BnHx) (n = 3-11, x >8), and the closoborane B12H12 dianion as a minor product. A BH condensation mechanism involving metal hydride formation is proposed to explain the limited reversible hydrogen storage in magnesium borohydride.

  16. Initial observations on using magnesium metal in peripheral nerve repair.

    PubMed

    Vennemeyer, J J; Hopkins, T; Hershcovitch, M; Little, K D; Hagen, M C; Minteer, D; Hom, D B; Marra, K; Pixley, S K

    2015-03-01

    Biodegradable magnesium metal filaments placed inside biodegradable nerve conduits might provide the physical guidance support needed to improve the rate and extent of regeneration of peripheral nerves across injury gaps. In this study, we examined basic issues of magnesium metal resorption and biocompatibility by repairing sub-critical size gap injuries (6 mm) in one sciatic nerve of 24 adult male Lewis rats. Separated nerve stumps were connected with poly(caprolactone) nerve conduits, with and without magnesium filaments (0.25 mm diameter, 10 mm length), with two different conduit filler substances (saline and keratin hydrogel). At 6 weeks after implantation, magnesium degradation was examined by micro-computed tomography and histological analyses. Magnesium degradation was significantly greater when the conduits were filled with an acidic keratin hydrogel than with saline (p < 0.05). But magnesium filaments in some animals remained intact for 6 weeks. Using histological and immunocytochemical analyses, good biocompatibility of the magnesium implants was observed at 6 weeks, as shown by good development of regenerating nerve mini-fascicles and only mild inflammation in tissues even after complete degradation of the magnesium. Nerve regeneration was not interrupted by complete magnesium degradation. An initial functional evaluation, determination of size recovery of the gastrocnemius muscle, showed a slight improvement due to magnesium with the saline but not the keratin filler, compared with respective control conduits without magnesium. These results suggest that magnesium filament implants have the potential to improve repair of injured peripheral nerve defects in this rodent model. PMID:25281648

  17. Impurity control and corrosion resistance of magnesium-aluminum alloy

    SciTech Connect

    Liu, M.; Song, GuangLing

    2013-01-01

    The corrosion resistance of magnesium alloys is very sensitive to the contents of impurity elements such as iron. In this study, a series of diecast AXJ530 magnesium alloy samples were prepared with additions of Mn and Fe. Through a comprehensive phase diagram calculation and corrosion evaluation, the mechanisms for the tolerance limit of Fe in magnesium alloy are discussed. This adds a new dimension to control the alloying impurity in terms of alloying composition design and casting conditions.

  18. Design Considerations of a Condensing System for Vaporized Magnesium

    NASA Technical Reports Server (NTRS)

    Witzke, Walter R; Prok, George M; Keller, Thomas A

    1955-01-01

    The effect of the design characteristics of various condensing chambers on magnesium build-up at the chamber inlet was investigated. The condensing chambers are used in the vapor-condensation process for making magnesium slurries. A complete description of the various chamber designs and the procedure used in testing the chambers is given. The results are evaluated on the basis of clogging and total magnesium distilled per run. Orifice design was also considered.

  19. Joint solubility of samarium and dysprosium in solid magnesium

    NASA Astrophysics Data System (ADS)

    Rokhlin, L. L.; Dobatkina, T. V.; Lukyanova, E. A.; Korolkova, I. G.; Tarytina, I. E.

    2016-03-01

    The phase compositions of solid Mg-Sm-Dy alloys corresponding to the magnesium-corner region of the phase diagram are studied by optical and scanning electron microscopy, electrical resistivity measurements, and electron microprobe analysis. The obtained results allowed us to determine the joint solubility of samarium and dysprosium in solid magnesium at 500, 400, and 300°C; it decreases with decreasing temperature. The magnesium solid solution is found to be in equilibrium only with the Mg41Sm5 and Mg24Dy5 compounds, which are in equilibrium with the magnesium solid solution in the binary Mg-Sm and Mg-Dy systems.

  20. Improved biological performance of magnesium by micro-arc oxidation

    PubMed Central

    Ma, W.H.; Liu, Y.J.; Wang, W.; Zhang, Y.Z.

    2014-01-01

    Magnesium and its alloys have recently been used in the development of lightweight, biodegradable implant materials. However, the corrosion properties of magnesium limit its clinical application. The purpose of this study was to comprehensively evaluate the degradation behavior and biomechanical properties of magnesium materials treated with micro-arc oxidation (MAO), which is a new promising surface treatment for developing corrosion resistance in magnesium, and to provide a theoretical basis for its further optimization and clinical application. The degradation behavior of MAO-treated magnesium was studied systematically by immersion and electrochemical tests, and its biomechanical performance when exposed to simulated body fluids was evaluated by tensile tests. In addition, the cell toxicity of MAO-treated magnesium samples during the corrosion process was evaluated, and its biocompatibility was investigated under in vivo conditions. The results of this study showed that the oxide coating layers could elevate the corrosion potential of magnesium and reduce its degradation rate. In addition, the MAO-coated sample showed no cytotoxicity and more new bone was formed around it during in vivo degradation. MAO treatment could effectively enhance the corrosion resistance of the magnesium specimen and help to keep its original mechanical properties. The MAO-coated magnesium material had good cytocompatibility and biocompatibility. This technique has an advantage for developing novel implant materials and may potentially be used for future clinical applications. PMID:25517917

  1. Magnesium deficiency accelerates cellular senescence in cultured human fibroblasts.

    PubMed

    Killilea, David W; Ames, Bruce N

    2008-04-15

    Magnesium inadequacy affects more than half of the U.S. population and is associated with increased risk for many age-related diseases, yet the underlying mechanisms are unknown. Altered cellular physiology has been demonstrated after acute exposure to severe magnesium deficiency, but few reports have addressed the consequences of long-term exposure to moderate magnesium deficiency in human cells. Therefore, IMR-90 human fibroblasts were continuously cultured in magnesium-deficient conditions to determine the long-term effects on the cells. These fibroblasts did not demonstrate differences in cellular viability or plating efficiency but did exhibit a decreased replicative lifespan in populations cultured in magnesium-deficient compared with standard media conditions, both at ambient (20% O(2)) and physiological (5% O(2)) oxygen tension. The growth rates for immortalized IMR-90 fibroblasts were not affected under the same conditions. IMR-90 fibroblast populations cultured in magnesium-deficient conditions had increased senescence-associated beta-galactosidase activity and increased p16(INK4a) and p21(WAF1) protein expression compared with cultures from standard media conditions. Telomere attrition was also accelerated in cell populations from magnesium-deficient cultures. Thus, the long-term consequence of inadequate magnesium availability in human fibroblast cultures was accelerated cellular senescence, which may be a mechanism through which chronic magnesium inadequacy could promote or exacerbate age-related disease. PMID:18391207

  2. Rapid recovery from major depression using magnesium treatment.

    PubMed

    Eby, George A; Eby, Karen L

    2006-01-01

    Major depression is a mood disorder characterized by a sense of inadequacy, despondency, decreased activity, pessimism, anhedonia and sadness where these symptoms severely disrupt and adversely affect the person's life, sometimes to such an extent that suicide is attempted or results. Antidepressant drugs are not always effective and some have been accused of causing an increased number of suicides particularly in young people. Magnesium deficiency is well known to produce neuropathologies. Only 16% of the magnesium found in whole wheat remains in refined flour, and magnesium has been removed from most drinking water supplies, setting a stage for human magnesium deficiency. Magnesium ions regulate calcium ion flow in neuronal calcium channels, helping to regulate neuronal nitric oxide production. In magnesium deficiency, neuronal requirements for magnesium may not be met, causing neuronal damage which could manifest as depression. Magnesium treatment is hypothesized to be effective in treating major depression resulting from intraneuronal magnesium deficits. These magnesium ion neuronal deficits may be induced by stress hormones, excessive dietary calcium as well as dietary deficiencies of magnesium. Case histories are presented showing rapid recovery (less than 7 days) from major depression using 125-300 mg of magnesium (as glycinate and taurinate) with each meal and at bedtime. Magnesium was found usually effective for treatment of depression in general use. Related and accompanying mental illnesses in these case histories including traumatic brain injury, headache, suicidal ideation, anxiety, irritability, insomnia, postpartum depression, cocaine, alcohol and tobacco abuse, hypersensitivity to calcium, short-term memory loss and IQ loss were also benefited. Dietary deficiencies of magnesium, coupled with excess calcium and stress may cause many cases of other related symptoms including agitation, anxiety, irritability, confusion, asthenia, sleeplessness

  3. Magnesium, aluminum and lead in various brain areas

    SciTech Connect

    Zumkley, H.; Bertram, H.P.; Brandt, M.; Roedig, M.; Spieker, C.

    1986-01-01

    Whereas the lead concentrations were increased in brain tissue of patients with chronic alcoholism, the aluminum concentrations remained within the normal range. The magnesium concentrations were found decreased in patients with chronic alcoholism compared to normal controls. The sources for the elevated lead levels seem to be the increased intake of alcohol. The decreased magnesium levels are probably caused by an increased loss of magnesium with the urine, malnutrition, malabsorption, hormonal factors and drugs. Various neurological disorders which often accompanied chronic alcoholism may be caused or aggravated by lead encephalopathy and hypomagnesemia. Therapeutical implications may be the early substitution of magnesium deficiency in chronic alcoholism. 10 references, 5 figures.

  4. Improved biological performance of magnesium by micro-arc oxidation.

    PubMed

    Ma, W H; Liu, Y J; Wang, W; Zhang, Y Z

    2015-03-01

    Magnesium and its alloys have recently been used in the development of lightweight, biodegradable implant materials. However, the corrosion properties of magnesium limit its clinical application. The purpose of this study was to comprehensively evaluate the degradation behavior and biomechanical properties of magnesium materials treated with micro-arc oxidation (MAO), which is a new promising surface treatment for developing corrosion resistance in magnesium, and to provide a theoretical basis for its further optimization and clinical application. The degradation behavior of MAO-treated magnesium was studied systematically by immersion and electrochemical tests, and its biomechanical performance when exposed to simulated body fluids was evaluated by tensile tests. In addition, the cell toxicity of MAO-treated magnesium samples during the corrosion process was evaluated, and its biocompatibility was investigated under in vivo conditions. The results of this study showed that the oxide coating layers could elevate the corrosion potential of magnesium and reduce its degradation rate. In addition, the MAO-coated sample showed no cytotoxicity and more new bone was formed around it during in vivo degradation. MAO treatment could effectively enhance the corrosion resistance of the magnesium specimen and help to keep its original mechanical properties. The MAO-coated magnesium material had good cytocompatibility and biocompatibility. This technique has an advantage for developing novel implant materials and may potentially be used for future clinical applications. PMID:25517917

  5. 40 CFR 461.60 - Applicability; description of the magnesium subcategory.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... magnesium subcategory. 461.60 Section 461.60 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS BATTERY MANUFACTURING POINT SOURCE CATEGORY Magnesium Subcategory § 461.60 Applicability; description of the magnesium subcategory. This subpart applies...

  6. 40 CFR 461.60 - Applicability; description of the magnesium subcategory.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... magnesium subcategory. 461.60 Section 461.60 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS BATTERY MANUFACTURING POINT SOURCE CATEGORY Magnesium Subcategory § 461.60 Applicability; description of the magnesium subcategory. This subpart applies...

  7. Quantum-mechanical calculations and spectroscopic characteristics of magnesium glutamate glycine and magnesium glutamate arginine

    NASA Astrophysics Data System (ADS)

    Marcoin, W.; Pasterny, K.; Pasterna, G.; Wrzalik, R.

    2006-07-01

    Theoretical calculations of magnesium glutamate-glycine ([Mg(glu-gly)]) and magnesium glutamate-arginine ([Mg(glu-arg)]) structures and their spectroscopic characteristics have been performed in the gas phase with the GAUSSIAN 98 software package using density functional theory (DFT) at the B3PW91 level. The 6-31+G* basis set was selected due to their reasonable quality and size. NMR and IR measurements were carried out and obtained experimental 1H and 13C chemical shifts and IR spectra are compared with calculated spectral parameters.

  8. Rechargeable Magnesium Batteries: Low-Cost Rechargeable Magnesium Batteries with High Energy Density

    SciTech Connect

    2010-10-01

    BEEST Project: Pellion Technologies is developing rechargeable magnesium batteries that would enable an EV to travel 3 times farther than it could using Li-ion batteries. Prototype magnesium batteries demonstrate excellent electrochemical behavior; delivering thousands of charge cycles with very little fade. Nevertheless, these prototypes have always stored too little energy to be commercially viable. Pellion Technologies is working to overcome this challenge by rapidly screening potential storage materials using proprietary, high-throughput computer models. To date, 12,000 materials have been identified and analyzed. The resulting best materials have been electrochemically tested, yielding several very promising candidates.

  9. Stationary storage and purification of hydrogen using nickel-coated magnesium powder. Final technical report

    SciTech Connect

    1999-12-30

    The following conclusions were reached: (1) The concept of a coating on a magnesium particle serving as a well-supported hydrogen-permselective membrane is sound. (2) Magnesium nitride can be made to coat magnesium particles through chemical vapor deposition within a fluidized bed. (3) Magnesium nitride exhibits the properties necessary for such a coating. (4) Magnesium nitride is not chemically inert to hydrogen in the absence of ammonia at temperatures typically used to hydride/dehydride magnesium.

  10. Magnesium and metabolic syndrome: The role of magnesium in health and disease

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Metabolic syndrome is a constellation of conditions associated with elevated risk of diabetes and cardiovascular disease. Magnesium, the fourth most abundant cation in the human body and required in over 300 enzymatic reactions, has been shown in experimental, observational, and clinical studies to ...

  11. Magnesium isotope fractionation during hydrous magnesium carbonate precipitation with and without cyanobacteria

    NASA Astrophysics Data System (ADS)

    Mavromatis, Vasileios; Pearce, Christopher R.; Shirokova, Liudmila S.; Bundeleva, Irina A.; Pokrovsky, Oleg S.; Benezeth, Pascale; Oelkers, Eric H.

    2012-01-01

    The hydrous magnesium carbonates, nesquehonite (MgCO 3·3H 2O) and dypingite (Mg 5(CO 3) 4(OH) 2·5(H 2O)), were precipitated at 25 °C in batch reactors from aqueous solutions containing 0.05 M NaHCO 3 and 0.025 M MgCl 2 and in the presence and absence of live photosynthesizing Gloeocapsa sp. cyanobacteria. Experiments were performed under a variety of conditions; the reactive fluid/bacteria/mineral suspensions were continuously stirred, and/or air bubbled in most experiments, and exposed to various durations of light exposure. Bulk precipitation rates are not affected by the presence of bacteria although the solution pH and the degree of fluid supersaturation with respect to magnesium carbonates increase due to photosynthesis. Lighter Mg isotopes are preferentially incorporated into the precipitated solids in all experiments. Mg isotope fractionation between the mineral and fluid in the abiotic experiments is identical, within uncertainty, to that measured in cyanobacteria-bearing experiments; measured δ 26Mg ranges from -1.54‰ to -1.16‰ in all experiments. Mg isotope fractionation is also found to be independent of reactive solution pH and Mg, CO 32-, and biomass concentrations. Taken together, these observations suggest that Gloeocapsa sp. cyanobacterium does not appreciably affect magnesium isotope fractionation between aqueous fluid and hydrous magnesium carbonates.

  12. Oral administration of lithium increases tissue magnesium contents but not plasma magnesium level in rats.

    PubMed

    Kiełczykowska, Małgorzata; Musik, Irena; Hordyjewska, Anna; Boguszewska, Anna; Lewandowska, Anna; Pasternak, Kazimierz

    2007-01-01

    The aim of this work was to determine the influence of different doses of lithium on magnesium concentration in plasma and tissues of rats. For a period of eight weeks rats had been provided with aqueous solutions of Li(2)CO(3) whose concentrations were established as follows: 0.7; 1.4; 2.6; 3.6; 7.1; 10.7 mmol Li(+)/l. Magnesium concentration was determined in plasma and tissue supernatants. Lithium caused no changes in magnesium concentration in plasma, whereas Mg concentration in tissues was found to be enhanced, although the degree of the increment depended on the studied tissue. In the liver, brain and heart muscle, the increase was statistically insignificant vs. control. In the kidney, the higher Li doses were required to result in the significant Mg enhancement, whereas in femoral muscle all the used doses caused well-marked Mg increase vs. control. Positive correlations between average daily Li intake and tissue Mg concentration in the kidney (r = 0.650) and femoral muscle (r = 0.696) were found. In conclusion, the present study indicates that the different Li doses disturbed tissue homeostasis of magnesium. The increase in Mg tissue concentration, observed in groups receiving higher Li doses can influence nervous-muscular excitability. PMID:17652829

  13. High concentration magnesium borohydride/tetraglyme electrolyte for rechargeable magnesium batteries

    NASA Astrophysics Data System (ADS)

    Tuerxun, Feilure; Abulizi, Yasen; NuLi, Yanna; Su, Shuojian; Yang, Jun; Wang, JiuLin

    2015-02-01

    High concentration magnesium borohydride/tetraglyme electrolyte for rechargeable magnesium batteries is simply prepared by dissolving inorganic magnesium salt Mg(BH4) in tetraglyme (TG) ether solvent with good safety. 90 °C heating treatment is performed in the preparation process and LiBH4 as a chelating agent is added to improve the electrochemical performance. Mg deposition-dissolution performance and the electrochemical window of the electrolyte on non-inert stainless steel (SS), nickel (Ni), copper (Cu) electrodes and inert platinum (Pt) electrode are systematically studied by cyclic voltammetry and constant current discharge-charge measurements. 0.5 mol L-1 heated Mg(BH4)2/LiBH4/TG ([LiBH4] = 1.5 mol L-1) solution shows good electrochemical performance with 2.4 V (vs. Mg RE) anodic stability on stainless steel, close to 100% Mg deposition/dissolution efficiency and high cycling reversibility. Furthermore, the reversible electrochemical process of Mg intercalation into Mo6S8 cathode with excellent cycling performance in the electrolyte indicates the feasible application in rechargeable magnesium batteries.

  14. Magnesium Battery Electrolytes in Ionic Liquids

    NASA Astrophysics Data System (ADS)

    Watkins, Tylan Strike

    A lack of adequate energy storage technologies is arguably the greatest hindrance to a modern sustainable energy infrastructure. Chemical energy storage, in the form of batteries, is an obvious solution to the problem. Unfortunately, today's state of the art battery technologies fail to meet the desired metrics for full scale electric grid and/or electric vehicle role out. Considerable effort from scientists and engineers has gone into the pursuit of battery chemistries theoretically capable of far outperforming leading technologies like Li-ion cells. For instance, an anode of the relatively abundant and cheap metal, magnesium, would boost the specific energy by over 4.6 times that of the current Li-ion anode (LiC6). The work presented here explores the compatibility of magnesium electrolytes in TFSI---based ionic liquids with a Mg anode (TFSI = bis(trifluoromethylsulfonyl)imide). Correlations are made between the Mg2+ speciation conditions in bulk solutions (as determined via Raman spectroscopy) and the corresponding electrochemical behavior of the electrolytes. It was found that by creating specific chelating conditions, with an appropriate Mg salt, the desired electrochemical behavior could be obtained, i.e. reversible electrodeposition and dissolution. Removal of TFSI -- contact ion pairs from the Mg2+ solvation shell was found to be essential for reversible electrodeposition. Ionic liquids with polyethylene glycol chains pendent from a parent pyrrolidinium cation were synthesized and used to create the necessary complexes with Mg 2+, from Mg(BH4)2, so that reversible electrodeposition from a purely ionic liquid medium was achieved. The following document discusses findings from several electrochemical experiments on magnesium electrolytes in ionic liquids. Explanations for the failure of many of these systems to produce reversible Mg electrodeposition are provided. The key characteristics of ionic liquid systems that are capable of achieving reversible Mg

  15. Disorders Involving Calcium, Phosphorus, and Magnesium

    PubMed Central

    Moe, Sharon M.

    2008-01-01

    Abnormalities of calcium, phosphorus and magnesium homeostasis are common, and collectively are called disorders of mineral metabolism. Normal homeostatic regulation maintains serum levels, intracellular levels, and optimal mineral content in bone. This regulation occurs at three major target organs, the intestine, kidney and bone, principally via the complex integration of two hormones, parathyroid hormone and vitamin D. An understanding of normal physiology is necessary to accurately diagnose and treat disorders of mineral metabolism and will be briefly reviewed before discussing the differential diagnosis and treatment of specific disorders. PMID:18486714

  16. Nanostructured Magnesium Hydride for Reversible Hydrogen Storage

    NASA Astrophysics Data System (ADS)

    de Rango, P.; Chaise, A.; Fruchart, D.; Miraglia, S.; Marty, Ph.

    2013-05-01

    The aim of this work was to develop suitable materials to store hydrogen in a solid state. A systematic investigation of the co-milling process of magnesium hydride with a transition metal was undertaken in order to produce nanostructured and highly reactive powders. The initiating role of the transition metal was evidenced by in situ neutron diffraction experiments. High performances in terms of thermal and mechanical behavior were achieved introducing expanded graphite and compacting the mixture to form composite materials. Absorption and desorption kinetics have been measured versus temperature and H2 pressure.

  17. 40 CFR 721.10021 - Magnesium potassium titanium oxide.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... § 721.63 respirator requirements may request to do so under 40 CFR 721.30. Persons whose § 721.30... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Magnesium potassium titanium oxide... Specific Chemical Substances § 721.10021 Magnesium potassium titanium oxide. (a) Chemical substance...

  18. 75 FR 9252 - Magnesium From China and Russia

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-01

    ... magnesium (also known as magnesium metal) from China and Russia (70 FR 19928-19931). The Commission is... 207), as most recently amended at 74 FR 2847 (January 16, 2009). \\1\\ No response to this request for... employment statute for Federal employees, and Commission rule 201.15(b) (19 CFR 201.15(b)), 73 FR 24609...

  19. 75 FR 35086 - Magnesium From China and Russia

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-21

    ... group responses to its notice of institution (75 FR 9252, March 1, 2010) were adequate.\\1\\ A record of... COMMISSION Magnesium From China and Russia AGENCY: United States International Trade Commission. ACTION... orders on magnesium from China and Russia. SUMMARY: The Commission hereby gives notice that it...

  20. Fogging technique used to coat magnesium with plastic

    NASA Technical Reports Server (NTRS)

    Mroz, T. S.

    1967-01-01

    Cleaning process and a fogging technique facilitate the application of a plastic coating to magnesium plates. The cleaning process removes general organic and inorganic surface impurities, oils and greases, and oxides and carbonates from the magnesium surfaces. The fogging technique produces a thin-filmlike coating in a clean room atmosphere.

  1. Casting Porosity-Free Grain Refined Magnesium Alloys

    SciTech Connect

    Schwam, David

    2013-08-12

    The objective of this project was to identify the root causes for micro-porosity in magnesium alloy castings and recommend remedies that can be implemented in production. The findings confirm the key role played by utilizing optimal gating and risering practices in minimizing porosity in magnesium castings. 

  2. The twin-roll strip casting of magnesium

    NASA Astrophysics Data System (ADS)

    Liang, D.; Cowley, C. B.

    2004-05-01

    Commonwealth Scientific & Industrial Research Organization has been working since 2000 to develop twin-roll strip casting of magnesium alloy. The primary objective was to significantly reduce the manufacturing cost of the magnesium sheet through the twin-roll casting process. This article describes the goals and challenges of this project as well as pilot plant test results.

  3. 40 CFR 721.10021 - Magnesium potassium titanium oxide.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... § 721.63 respirator requirements may request to do so under 40 CFR 721.30. Persons whose § 721.30... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Magnesium potassium titanium oxide... Specific Chemical Substances § 721.10021 Magnesium potassium titanium oxide. (a) Chemical substance...

  4. 40 CFR 721.10021 - Magnesium potassium titanium oxide.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... § 721.63 respirator requirements may request to do so under 40 CFR 721.30. Persons whose § 721.30... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Magnesium potassium titanium oxide... Specific Chemical Substances § 721.10021 Magnesium potassium titanium oxide. (a) Chemical substance...

  5. 40 CFR 721.10021 - Magnesium potassium titanium oxide.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... § 721.63 respirator requirements may request to do so under 40 CFR 721.30. Persons whose § 721.30... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Magnesium potassium titanium oxide... Specific Chemical Substances § 721.10021 Magnesium potassium titanium oxide. (a) Chemical substance...

  6. 40 CFR 721.10021 - Magnesium potassium titanium oxide.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... § 721.63 respirator requirements may request to do so under 40 CFR 721.30. Persons whose § 721.30... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Magnesium potassium titanium oxide... Specific Chemical Substances § 721.10021 Magnesium potassium titanium oxide. (a) Chemical substance...

  7. Association of Cord Blood Magnesium Concentration and Neonatal Resuscitation

    PubMed Central

    Johnson, Lynn H.; Mapp, Delicia C.; Rouse, Dwight J.; Spong, Catherine Y.; Mercer, Brian M.; Leveno, Kenneth J.; Varner, Michael W.; Iams, Jay D.; Sorokin, Yoram; Ramin, Susan M.; Miodovnik, Menachem; O'Sullivan, Mary J.; Peaceman, Alan M.; Caritis, Steve N.

    2014-01-01

    Objective Assess the relationship between umbilical cord blood magnesium concentration and level of delivery room resuscitation received by neonates. Study design Secondary analysis of a controlled fetal neuroprotection trial that enrolled women at imminent risk for delivery between 24 and 31 weeks’ gestation and randomly allocated them to receive intravenous magnesium sulfate or placebo. The cohort included 1507 infants for whom total cord blood magnesium concentration and delivery room resuscitation information were available. Multivariable logistic regression was used to estimate the association between cord blood magnesium concentration and highest level of delivery room resuscitation, using the following hierarchy: none, oxygen only, bag-mask ventilation with oxygen, intubation or chest compressions. Results There was no relationship between cord blood magnesium and delivery room resuscitation (odds ratio [OR] 0.92 for each 1.0 mEq/L increase in magnesium; 95% confidence interval [CI]: 0.83-1.03). Maternal general anesthesia was associated with increased neonatal resuscitation (OR 2.51; 95% CI: 1.72-3.68). Each 1-week increase in gestational age at birth was associated with decreased neonatal resuscitation (OR 0.63; 95% CI: 0.60 – 0.66). Conclusion Cord blood magnesium concentration does not correlate with the level of delivery room resuscitation of infants exposed to magnesium sulfate for fetal neuroprotection. PMID:22056282

  8. Biodegradable resistive switching memory based on magnesium difluoride.

    PubMed

    Zhang, Zhiping; Tsang, Melissa; Chen, I-Wei

    2016-08-11

    This study presents a new type of resistive switching memory device that can be used in biodegradable electronic applications. The biodegradable device features magnesium difluoride as the active layer and iron and magnesium as the corresponding electrodes. This is the first report on magnesium difluoride as a resistive switching layer. With on-off ratios larger than one hundred, the device on silicon switches at voltages less than one volt and requires only sub-mA programming current. AC endurance of 10(3) cycles is demonstrated with ±1 V voltage pulses. The switching mechanism is attributed to the formation and rupture of conductive filaments comprising fluoride vacancies in magnesium difluoride. Devices fabricated on a flexible polyethylene terephthalate substrate are tested for functionality, and degradation is subsequently demonstrated in de-ionized water. An additional layer of magnesium difluoride is used to hinder the degradation and extend the lifetime of the device. PMID:27476796

  9. Neurotic, neuromuscular and autonomic nervous form of magnesium imbalance.

    PubMed

    Durlach, J; Bac, P; Durlach, V; Bara, M; Guiet-Bara, A

    1997-06-01

    The nervous form of magnesium imbalance represents the best documented experimental and clinical aspects of magnesium disorders. The nervous form of primary magnesium deficit (MD) in the adult appears as the best descriptive model for analysis of the symptomatology, aetiology, physiopathology, diagnosis and therapy of the most frequent form of MD. Nervous hyperexcitability due to chronic MD in the adult results in a non-specific clinical pattern with associated central and peripheral neuromuscular symptoms, analogous to the symptomatology previously described in medical literature as latent tetany, hyperventilation syndrome, spasmophilia, chronic fatigue syndrome, neurocirculatory asthenia and idiopathic Barlow's disease. On encountering this non-specific pattern, the signs of neuromuscular hyperexcitability are of much greater importance. Trousseau's sign is less sensitive than Chvostek's sign, but their sensitivities are increased by hyperventilation (Von Bondsdorff's test). Examination of the precordial area will be conducted in order to search clinical stigmata of mitral valve prolapse (MVP) which is a frequent dyskinesia due to chronic MD (about a quarter to one-third of cases). The electromyogram (EMG) shows one (or several) trains of autorhythmic activities beating for more than 2 min of one of the three tetanic activities (uniplets, multiplets or 'complex tonicoclonic tracings') during one of the three facilitation procedures: tourniquet-induced ischaemia lasting 10 min. post-ischaemia lasting 10 min after the removal of the tourniquet and hyperventilation over 5 min. A repetitive EMG constitutes the principal mark of nervous hyperexcitability (NHE) due to MD. The echocardiogram (ECC) is the best tool for detecting MVP, the 2-dimensional ECC with pulsed Doppler being more accurate than time-motion ECC. The routine ionic investigations comprise five static tests: plasma and erythrocyte magnesium, plasma calcium and daily magnesiuria and calciuria. An

  10. 1-Nitronapthalene as a cathode material for magnesium reserve batteries

    NASA Astrophysics Data System (ADS)

    Thirunakaran, R.; Vasudevan, S.; Sivashanmugam, A.; Kumar, Gopu; Muniyandi, N.

    1-Nitronaphthalene has been investigated for use as a battery depolarizer in conjunction with a high-energt magnesium anode. Acetylene black is added to improve the conductivity of the non-conducting organic compound and its concentration in the mix is optimized for better performance of the cathode. To assess its suitability and its characteristics as a cathode active material, magnesium/1-nitronaphthalene cells are fabricated and discharged in different electrolytes (magnesium chloride, magnesium bromide and magnesium perchlorate) at various current densities. The capacity delivered by the cell system shows better reduction efficiency of the 1-nitronaphthalene depolarizer. Cyclic voltammetric studies are carried out on a glassy-carbon electrode to understand the reduction behaviour of 1-nitronaphthalene.

  11. Thermal Stability of Magnesium Silicide/Nickel Contacts

    NASA Astrophysics Data System (ADS)

    de Boor, J.; Droste, D.; Schneider, C.; Janek, J.; Mueller, E.

    2016-06-01

    Magnesium silicide-based materials are a very promising class of thermoelectric materials with excellent potential for thermoelectric waste heat recovery. For the successful application of magnesium silicide-based thermoelectric generators, the development of long-term stable contacts with low contact resistance is as important as material optimization. We have therefore studied the suitability of Ni as a contact material for magnesium silicide. Co-sintering of magnesium silicide and Ni leads to the formation of a stable reaction layer with low electrical resistance. In this paper we show that the contacts retain their low electrical contact resistance after annealing at temperatures up to 823 K for up to 168 h. By employing scanning electron microscope analysis and time-of-flight (ToF)-secondary ion mass spectrometry, we can further show that elemental diffusion is occurring to a very limited extent. This indicates long-term stability under practical operation conditions for magnesium silicide/nickel contacts.

  12. Serum magnesium concentration in drug-addicted patients.

    PubMed

    Karakiewicz, Beata; Kozielec, Tadeusz; Brodowski, Jacek; Chlubek, Dariusz; Noceń, Iwona; Starczewski, Andrzej; Brodowska, Agnieszka; Laszczyńska, Maria

    2007-03-01

    Drug addiction is a complex problem which leads to many somatic, psychic and social diseases. It is accompanied by the disturbed metabolism of various macro and micronutrients. The aim of this study was to assess serum magnesium concentration in drug-addicted patients and analyze whether Human Immunodeficiency Virus (HIV) infection and methadone treatment affect the level of serum magnesium in these patients. The examination was conducted in a group of 83 people - patients of Szczecin-Zdroje Psychiatric Hospital (Poland). They were 21 to 49 years old, and the mean age was 32 +/- 7 years. The control group consisted of 81 healthy individuals. Flame atomic-absorption spectrometry method was used to determine the magnesium concentration. The total serum magnesium concentration was calculated for the whole patient group, subgroups of women and men, a subgroup of people infected with HIV, and a subgroup receiving methadone substitution treatment. How magnesium behaves depending on age and addiction period, was checked. The mean concentration of magnesium in blood serum of the patients examined was 0.57 mmol/L, which was significantly lower than in the control group. In the subgroup of men it was 0.57 mmol/L, and in the subgroup of women - 0.55 mmol/L; the differences were not statistically significant. In the patient group nobody had the appropriate magnesium concentration in blood serum. No significant correlation was found between the magnesium concentration, age of the patients and addiction period. In the subgroup of seropositive people the mean concentration of magnesium was 0.55 mmol/L, and in the subgroup of non-infected patients - 0.58 mmol/L; the difference was not statistically significant. The mean concentration of magnesium in the subgroup treated with methadone was 0.59 mmol/L, and in the subgroup not involved in this type of therapy - 0.55 mmol/L; it was not a statistically significant difference. PMID:17536489

  13. Studies on Mechanisms of Hypocalcemia of Magnesium Depletion

    PubMed Central

    Reddy, Chilumula R.; Coburn, Jack W.; Hartenbower, David L.; Friedler, Robert M.; Brickman, Arnold S.; Massry, Shaul G.; Jowsey, Jenifer

    1973-01-01

    Studies were carried out to evaluate the mechanism of hypocalcemia in magnesium depletion. Day old chicks fed a magnesium deficient diet developed marked hypocalcemia, with a direct relation between serum calcium (y) and magnesium (x): y = 2.68 x + 4.24, r = 0.84 (both in mg/100 ml). Injections of parathyroid extract that increased serum calcium 2-3 mg/100 ml in normals had no effect in Mg-depleted birds. Very large dietary supplements of calcium or vitamin D3 increased mean serum calcium only from 5.3 to 7.7 and 7.8 mg/100 ml, respectively, while a normal magnesium diet for 3 days increased calcium from 5.3 to 9.9 mg/100 ml despite absence of dietary calcium. Intestinal calcium transport, studied in vitro, and the calcium concentration of the carcass was significantly increased in magnesium-depleted chicks, making it unlikely that reduced intestinal absorption of calcium caused the hypocalcemia. In magnesium-deficient chicks, the bone content of magnesium was decreased by 74%, the calcium content was unchanged, and the cortical thickness of bone was markedly increased. After 3 days of magnesium-repletion, cortical thickness was reduced with increased endosteal resorption. There was an increase in unmineralized osteoid tissue in the magnesium-depleted chicks. Parathyroid gland size and histology did not differ in magnesium-depleted and control birds. The results suggest that hypocalcemia develops due to altered equilibrium of calcium between extracellular fluid and bone, favoring increased net movement into the latter. Failure of parathyroid gland function could also exist, and unresponsiveness to parathyroid hormone (PTH) may also contribute to the hypocalcemia. However, failure of PTH action is probably due to the presence of excess osteoid tissue rather than a primary event leading to hypocalcemia. Images PMID:4750437

  14. Synthesis of nanoscale magnesium diboride powder

    NASA Astrophysics Data System (ADS)

    Finnemore, D. K.; Marzik, J. V.

    2015-12-01

    A procedure has been developed for the preparation of small grained magnesium diboride (MgB2) powder by reacting nanometer size boron powder in a magnesium vapor. Plasma synthesized boron powder that had particle sizes ranging from 20 to 300nm was mixed with millimeter size chunks of Mg by rolling stoichiometric amounts of the powders in a sealed cylindrical container under nitrogen gas. This mixture then was placed in a niobium reaction vessel, evacuated, and sealed by e-beam welding. The vessel was typically heated to approximately 830°C for several hours. The resulting MgB2 particles have a grain size in the 200 nm to 800 nm range. Agglomerates of loosely bound particles could be broken up by light grinding in a mortar and pestle. At 830°C, many particles are composed of several grains grown together so that the average particle size is about twice the average grain size. Experiments were conducted primarily with undoped boron powder, but carbon-doped boron powder showed very similar results.

  15. Prototype systems for rechargeable magnesium batteries.

    PubMed

    Aurbach, D; Lu, Z; Schechter, A; Gofer, Y; Gizbar, H; Turgeman, R; Cohen, Y; Moshkovich, M; Levi, E

    2000-10-12

    The thermodynamic properties of magnesium make it a natural choice for use as an anode material in rechargeable batteries, because it may provide a considerably higher energy density than the commonly used lead-acid and nickel-cadmium systems. Moreover, in contrast to lead and cadmium, magnesium is inexpensive, environmentally friendly and safe to handle. But the development of Mg batteries has been hindered by two problems. First, owing to the chemical activity of Mg, only solutions that neither donate nor accept protons are suitable as electrolytes; but most of these solutions allow the growth of passivating surface films, which inhibit any electrochemical reaction. Second, the choice of cathode materials has been limited by the difficulty of intercalating Mg ions in many hosts. Following previous studies of the electrochemistry of Mg electrodes in various non-aqueous solutions, and of a variety of intercalation electrodes, we have now developed rechargeable Mg battery systems that show promise for applications. The systems comprise electrolyte solutions based on Mg organohaloaluminate salts, and Mg(x)Mo3S4 cathodes, into which Mg ions can be intercalated reversibly, and with relatively fast kinetics. We expect that further improvements in the energy density will make these batteries a viable alternative to existing systems. PMID:11048714

  16. Synthesis of nanoscale magnesium diboride powder

    DOE PAGESBeta

    Finnemore, D. K.; Marzik, J. V.

    2015-12-18

    A procedure has been developed for the preparation of small grained magnesium diboride (MgB2) powder by reacting nanometer size boron powder in a magnesium vapor. Plasma synthesized boron powder that had particle sizes ranging from 20 to 300nm was mixed with millimeter size chunks of Mg by rolling stoichiometric amounts of the powders in a sealed cylindrical container under nitrogen gas. This mixture then was placed in a niobium reaction vessel, evacuated, and sealed by e-beam welding. The vessel was typically heated to approximately 830°C for several hours. The resulting MgB2 particles have a grain size in the 200 nmmore » to 800 nm range. Agglomerates of loosely bound particles could be broken up by light grinding in a mortar and pestle. At 830°C, many particles are composed of several grains grown together so that the average particle size is about twice the average grain size. Furthermore, experiments were conducted primarily with undoped boron powder, but carbon-doped boron powder showed very similar results.« less

  17. Deuterium storage in nanocrystalline magnesium thin films

    NASA Astrophysics Data System (ADS)

    Checchetto, R.; Bazzanella, N.; Miotello, A.; Brusa, R. S.; Zecca, A.; Mengucci, A.

    2004-02-01

    Nanocrystalline magnesium deuteride thin films with the β-MgD2 structure were prepared by vacuum evaporation of hexagonal magnesium (h-Mg) samples and thermal annealing in 0.15 MPa D2 atmosphere at 373 K. Thermal desorption spectroscopy analysis indicated that the rate-limiting step in the deuterium desorption was given by the thermal decomposition of the deuteride phase. The activation energy Δg of the β-MgD2→h-Mg+D2 reaction scaled from 1.13±0.03 eV in 650-nm-thick films to 1.01±0.02 eV in 75-nm-thick films most likely as consequence of different stress and defect level. Positron annihilation spectroscopy analysis of the thin-film samples submitted to deuterium absorption and desorption cycles reveal the presence of a high concentration of void-like defects in the h-Mg layers after the very first decomposition of the β-MgD2 phase, the presence of these open volume defects reduces the D2 absorption capacity of the h-Mg thin film.

  18. Synthesis of nanoscale magnesium diboride powder

    SciTech Connect

    Finnemore, D. K.; Marzik, J. V.

    2015-12-18

    A procedure has been developed for the preparation of small grained magnesium diboride (MgB2) powder by reacting nanometer size boron powder in a magnesium vapor. Plasma synthesized boron powder that had particle sizes ranging from 20 to 300nm was mixed with millimeter size chunks of Mg by rolling stoichiometric amounts of the powders in a sealed cylindrical container under nitrogen gas. This mixture then was placed in a niobium reaction vessel, evacuated, and sealed by e-beam welding. The vessel was typically heated to approximately 830°C for several hours. The resulting MgB2 particles have a grain size in the 200 nm to 800 nm range. Agglomerates of loosely bound particles could be broken up by light grinding in a mortar and pestle. At 830°C, many particles are composed of several grains grown together so that the average particle size is about twice the average grain size. Furthermore, experiments were conducted primarily with undoped boron powder, but carbon-doped boron powder showed very similar results.

  19. Fabrication of multilayer pancakelike basic magnesium carbonate.

    PubMed

    Sun, Jinhe; Jia, Yongzhong; Yan Jing; Yao, Ying; Ma, Jun

    2014-10-01

    The properties of nanomaterials was strongly affected by their microstructures. Here Mg5(CO3)4(OH)2 x 4H2O multilayer pancakelike structures were fabricated successfully by reaction of MgCl2 and Na2CO3 in aqueous solution at 363 K. The growth process of nanostructures was observed by XRD and SEM. Several transition states of multilayer pancakelike basic magnesium carbonates were observed, which help to understand better the formation process of this hierarchical nanostructures. The formation mechanism of Mg5(CO3)4(OH)2 x 4H2O multilayer pancakelike structures was discussed and helical growth was proposed. The amorphous nanoparticles were formed firstly. Then nanopartilces aggregated and oriented assembly under the direction of chemical bonds with the help of water molecules. The multilayer pancakelike basic magnesium carbonates was formed by helical growth of wafers along (100) and (001) direction. The diameter and volume decreased with the increasing concentration of reactants. PMID:25942931

  20. Blackening of magnesium alloy using femtosecond laser.

    PubMed

    Shi, Haixia; Cui, Zeqin; Wang, Wenxian; Xu, Bingshe; Gong, Dianqing; Zhang, Wei

    2015-09-01

    Magnesium alloy, a potential structural and biodegradable material, has been increasingly attracting attention. In this paper, two structures with enhanced light absorption on an AZ31B magnesium surface are fabricated by femtosecond laser texturing. Laser power and the number of laser pulses are mainly investigated for darkening effect. After irradiation, surface characteristics are analyzed by a scanning electron microscope equipped with an energy dispersive spectrometer and laser scanning confocal microscope. The darkening effect is investigated by a spectrophotometer with an integrating sphere. Microgroove and stripe structures are obtained, which are covered with homogeneous nanoprotrusions and nanoparticles. The main surface chemical composition after laser ablation is MgO. The optimal light absorption in the visible range (wavelength of 400-800 nm) reaches about 98%, which is significantly improved compared with the untreated surface. The enhanced light absorption is mainly attributed to surface structure. Femtosecond laser surface texturing technology offers potential in the application of stealth technology, airborne devices, and biomedicine. PMID:26368903

  1. Thermochemistry of dense hydrous magnesium silicates

    NASA Technical Reports Server (NTRS)

    Bose, Kunal; Burnley, Pamela; Navrotsky, Alexandra

    1994-01-01

    Recent experimental investigations under mantle conditions have identified a suite of dense hydrous magnesium silicate (DHMS) phases that could be conduits to transport water to at least the 660 km discontinuity via mature, relatively cold, subducting slabs. Water released from successive dehydration of these phases during subduction could be responsible for deep focus earthquakes, mantle metasomatism and a host of other physico-chemical processes central to our understanding of the earth's deep interior. In order to construct a thermodynamic data base that can delineate and predict the stability ranges for DHMS phases, reliable thermochemical and thermophysical data are required. One of the major obstacles in calorimetric studies of phases synthesized under high pressure conditions has been limitation due to the small (less than 5 mg) sample mass. Our refinement of calorimeter techniques now allow precise determination of enthalpies of solution of less than 5 mg samples of hydrous magnesium silicates. For example, high temperature solution calorimetry of natural talc (Mg(0.99) Fe(0.01)Si4O10(OH)2), periclase (MgO) and quartz (SiO2) yield enthalpies of drop solution at 1044 K to be 592.2 (2.2), 52.01 (0.12) and 45.76 (0.4) kJ/mol respectively. The corresponding enthalpy of formation from oxides at 298 K for talc is minus 5908.2 kJ/mol agreeing within 0.1 percent to literature values.

  2. A Magnesium-Activated Carbon Hybrid Capacitor

    SciTech Connect

    Yoo, HD; Shterenberg, I; Gofer, Y; Doe, RE; Fischer, CC; Ceder, G; Aurbach, D

    2013-12-11

    Prototype cells of hybrid capacitor were developed, comprising activated carbon (AC) cloth and magnesium (Mg) foil as the positive and negative electrodes, respectively. The electrolyte solution included ether solvent (TBF) and a magnesium organo-halo-aluminate complex 0.25 M Mg2Cl3+-Ph2AlCl2-. In this solution Mg can be deposited/dissolved reversibly for thousands of cycles with high reversibility (100% cycling efficiency). The main barrier for integrating porous AC electrodes with this electrolyte solution was the saturation of the pores with the large ions in the AC prior to reaching the potential limit. This is due to the existence of bulky Mg and Al based ionic complexes consisting Cl, alkyl or aryl (R), and THF ligands. This problem was resolved by adding 0.5 M of lithium chloride (LiCl), thus introducing smaller ionic species to the solution. This Mg hybrid capacitor system demonstrated a stable cycle performance for many thousands of cycles with a specific capacitance of 90 Fg(-1) for the AC positive electrodes along a potential range of 2.4 V. (C) 2014 The Electrochemical Society. All rights reserved.

  3. Effect of magnesium on the burning characteristics of boron particles

    NASA Astrophysics Data System (ADS)

    Liu, Jian-zhong; Xi, Jian-fei; Yang, Wei-juan; Hu, You-rui; Zhang, Yan-wei; Wang, Yang; Zhou, Jun-hu

    2014-03-01

    Boron is an attractive fuel for propellants and explosives because of its high energy density. However, boron particles are difficult to combust because of inhibiting oxide layers that cover the particles. The use of magnesium as additives has been shown to promote boron oxidation. In this study, laser ignition facility and thermobalance were used to investigate the effect of magnesium on the burning characteristics of boron particles. The influences of magnesium addition on sample combustion flame, boron ignition delay time, boron combustion efficiency and initial temperature of boron oxidation. Results show that all Mg/B samples exhibit the same type of flame structure, i.e., a bright plume surrounded by green radiation which is interpreted as BO2 emission. The combustion flame intensity of a sample increases with the increasing magnesium content of boron particles. An increase in magnesium content results in a decrease and a subsequent increase in boron ignition delay time. (Mg/B)0.2 has a minimum ignition delay time of ~48 ms. Boron combustion efficiency increases with increasing magnesium addition. (Mg/B)0.5 shows a maximum boron combustion efficiency of ~64.2%. Magnesium addition decreases the initial temperature of boron oxidation.

  4. The history of biodegradable magnesium implants: a review.

    PubMed

    Witte, Frank

    2010-05-01

    Today, more than 200years after the first production of metallic magnesium by Sir Humphry Davy in 1808, biodegradable magnesium-based metal implants are currently breaking the paradigm in biomaterial science to develop only highly corrosion resistant metals. This groundbreaking approach to temporary metallic implants is one of the latest developments in biomaterials science that is being rediscovered. It is a challenging topic, and several secrets still remain that might revolutionize various biomedical implants currently in clinical use. Magnesium alloys were investigated as implant materials long ago. A very early clinical report was given in 1878 by the physician Edward C. Huse. He used magnesium wires as ligature for bleeding vessels. Magnesium alloys for clinical use were explored during the last two centuries mainly by surgeons with various clinical backgrounds, such as cardiovascular, musculoskeletal and general surgery. Nearly all patients benefited from the treatment with magnesium implants. Although most patients experienced subcutaneous gas cavities caused by rapid implant corrosion, most patients had no pain and almost no infections were observed during the postoperative follow-up. This review critically summarizes the in vitro and in vivo knowledge and experience that has been reported on the use of magnesium and its alloys to advance the field of biodegradable metals. PMID:20172057

  5. Reprint of: The history of biodegradable magnesium implants: A review.

    PubMed

    Witte, Frank

    2015-09-01

    Today, more than 200 years after the first production of metallic magnesium by Sir Humphry Davy in 1808, biodegradable magnesium-based metal implants are currently breaking the paradigm in biomaterial science to develop only highly corrosion resistant metals. This groundbreaking approach to temporary metallic implants is one of the latest developments in biomaterials science that is being rediscovered. It is a challenging topic, and several secrets still remain that might revolutionize various biomedical implants currently in clinical use. Magnesium alloys were investigated as implant materials long ago. A very early clinical report was given in 1878 by the physician Edward C. Huse. He used magnesium wires as ligature for bleeding vessels. Magnesium alloys for clinical use were explored during the last two centuries mainly by surgeons with various clinical backgrounds, such as cardiovascular, musculoskeletal and general surgery. Nearly all patients benefited from the treatment with magnesium implants. Although most patients experienced subcutaneous gas cavities caused by rapid implant corrosion, most patients had no pain and almost no infections were observed during the postoperative follow-up. This review critically summarizes the in vitro and in vivo knowledge and experience that has been reported on the use of magnesium and its alloys to advance the field of biodegradable metals. PMID:26235343

  6. Magnesium treatment for neuroprotection in ischemic diseases of the brain

    PubMed Central

    2013-01-01

    This article reviews experimental and clinical data on the use of magnesium as a neuroprotective agent in various conditions of cerebral ischemia. Whereas magnesium has shown neuroprotective properties in animal models of global and focal cerebral ischemia, this effect could not be reproduced in a large human stroke trial. These conflicting results may be explained by the timing of treatment. While treatment can be started before or early after ischemia in experimental studies, there is an inevitable delay of treatment in human stroke. Magnesium administration to women at risk for preterm birth has been investigated in several randomized controlled trials and was found to reduce the risk of neurological deficits for the premature infant. Postnatal administration of magnesium to babies after perinatal asphyxia has been studied in a number of controlled clinical trials. The results are promising but the trials have, so far, been underpowered. In aneurysmal subarachnoid hemorrhage (SAH), cerebral ischemia arises with the onset of delayed cerebral vasospasm several days after aneurysm rupture. Similar to perinatal asphyxia in impending preterm delivery, treatment can be started prior to ischemia. The results of clinical trials are conflicting. Several clinical trials did not show an additive effect of magnesium with nimodipine, another calcium antagonist which is routinely administered to SAH patients in many centers. Other trials found a protective effect after magnesium therapy. Thus, it may still be a promising substance in the treatment of secondary cerebral ischemia after aneurysmal SAH. Future prospects of magnesium therapy are discussed. PMID:23618347

  7. Cardioprotective effects of magnesium valproate in type 2 diabetes mellitus.

    PubMed

    Patel, Bhoomika M; Raghunathan, Suchi; Porwal, Urvashi

    2014-04-01

    We have evaluated the effect of magnesium valproate (210 mg/kg/day, p.o.) in type 2 diabetes induced cardiovascular complications induced by streptozotocin (STZ, 90 mg/kg, i.p.) in neonatal wistar rats. Various biochemical, cardiovascular and hemodynamic parameters were measured at the end of 8 weeks of treatment. STZ produced significant hyperglycaemia, hypoinsulinemia and dyslipidemia, which was prevented by magnesium valproate treatment. STZ produced increase in Creatinine Kinase, C-reactive protein and lactate dehydrogenase levels and treatment with magnesium valproate produced reduction in these levels. STZ produced increase in cardiac and LV hypertrophy index, LV/RV ratio, LV collagen deposition and LV cardiomyocyte diameter which were decreased by magnesium valproate treatment. Magnesium valproate also prevented STZ induced hemodynamic alterations and oxidative stress. These results were further supported by histopathological studies in which magnesium valproate showed marked reduction in fibrosis and cardiac fiber disarray. In conclusion, our data suggests that magnesium valproate is beneficial as an anti-diabetic agent in type-2 diabetes mellitus and also prevents its cardiac complications. PMID:24530414

  8. Synthesis, Crystal Structure, and Electrochemical Properties of a Simple Magnesium Electrolyte for Magnesium/Sulfur Batteries.

    PubMed

    Li, Wanfei; Cheng, Shuang; Wang, Jian; Qiu, Yongcai; Zheng, Zhaozhao; Lin, Hongzhen; Nanda, Sanjay; Ma, Qian; Xu, Yan; Ye, Fangmin; Liu, Meinan; Zhou, Lisha; Zhang, Yuegang

    2016-05-23

    Most simple magnesium salts tend to passivate the Mg metal surface too quickly to function as electrolytes for Mg batteries. In the present work, an electroactive salt [Mg(THF)6 ][AlCl4 ]2 was synthesized and structurally characterized. The Mg electrolyte based on this simple mononuclear salt showed a high Mg cycling efficiency, good anodic stability (2.5 V vs. Mg), and high ionic conductivity (8.5 mS cm(-1) ). Magnesium/sulfur cells employing the as-prepared electrolyte exhibited good cycling performance over 20 cycles in the range of 0.3-2.6 V, thus indicating an electrochemically reversible conversion of S to MgS without severe passivation of the Mg metal electrode surface. PMID:27094220

  9. Magnesium Based Materials and their Antimicrobial Activity

    NASA Astrophysics Data System (ADS)

    Robinson, Duane Allan

    The overall goals of this body of work were to characterize the antimicrobial properties of magnesium (Mg) metal and nano-magnesium oxide (nMgO) in vitro, to evaluate the in vitro cytotoxicity of Mg metal, and to incorporate MgO nanoparticles into a polymeric implant coating and evaluate its in vitro antimicrobial properties. In the course of this work it was found that Mg metal, Mg-mesh, and nMgO have in vitro antimicrobial properties that are similar to a bactericidal antibiotic. For Mg metal, the mechanism of this activity appears to be related to an increase in pH (i.e. a more alkaline environment) and not an increase in Mg2+. Given that Mg-mesh is a Mg metal powder, the assumption is that it has the same mechanism of activity as Mg metal. The mechanism of activity for nMgO remains to be elucidated and may be related to a combination of interaction of the nanoparticles with the bacteria and the alkaline pH. It was further demonstrated that supernatants from suspensions of Mg-mesh and nMgO had the same antimicrobial effect as was noted when the particles were used. The supernatant from Mg-mesh and nMgO was also noted to prevent biofilm formation for two Staphylococcus strains. Finally, poly-epsilon-caprolactone (PCL) composites of Mg-mesh (PCL+Mg-mesh) and nMgO (PCL+nMgO) were produced. Coatings applied to screws inhibited growth of Escherichia coli and Pseudomonas aeruginosa and in thin disc format inhibited the growth of Staphylococcus aureus in addition to the E. coli and P. aeruginosa. Pure Mg metal was noted to have some cytotoxic effect on murine fibroblast and osteoblast cell lines, although this effect needs to be characterized further. To address the need for an in vivo model for evaluating implant associated infections, a new closed fracture osteomyelitis model in the femur of the rat was developed. Magnesium, a readily available and inexpensive metal was shown to have antimicrobial properties that appear to be related to its corrosion products and

  10. Oral magnesium supplementation in type II diabetic patients

    PubMed Central

    Solati, Mehrdad; Ouspid, Elham; Hosseini, Saeedeh; Soltani, Nepton; Keshavarz, Mansoor; Dehghani, Mohsen

    2014-01-01

    Background: Magnesium is the second most abundant intracellular cation. It plays an important role in insulin homeostasis and glucose metabolism through multiple enzymatic reactions. With increasing data on magnesium deficiency in diabetic patients and epidemiological studies demonstrating magnesium deficiency as a risk factor for diabetes, it is logical to search for its possible beneficial effects on diabetes control and prevention. We aimed to determine whether oral magnesium supplementation improves metabolic control, lipid profile and blood pressure in patients with type II diabetes. Methods: Fifty four patients with type II diabetes were included in a randomized double blind placebocontrolled clinical trial.Patients received either placebo or 300 mg elemental magnesium (as magnesium sulfate -MgSo4-) daily, for 3 months. Metabolic control, lipid profile, blood pressure, magnesium status, hepatic enzymes, hemoglobin concentration, and anthropometric indices were determined in the beginning and at the end of the study. Results: Daily administration of 300 mg elemental magnesium for 3 months, significantly improved fasting blood glucose (183.9±15.43 to 125.8±6.52 vs. 196.5±28.12 to 136.5±7.94, p< 0.0001), 2-hour post prandial glucose (239.1±74.75 to 189.1±60mg/dl vs. 246.4±97.37 to 247.8±86.74mg/dl, p< 0.01), lipid profile, blood pressure and hepatic enzymes. Conclusion: Oral magnesium supplementation with proper dosage has beneficial effects on blood glucose, lipid profile, and blood pressure in patients with type II diabetes. PMID:25405132

  11. Characteristics of tetrahydrofuran-based electrolytes with magnesium alkoxide additives for rechargeable magnesium batteries

    NASA Astrophysics Data System (ADS)

    Kim, In-Tae; Yamabuki, Kazuhiro; Sumimoto, Michinori; Tsutsumi, Hiromori; Morita, Masayuki; Yoshimoto, Nobuko

    2016-08-01

    The electrochemical behavior of magnesium (Mg) metal was investigated in tetrahydrofuran (THF)-based solutions containing magnesium bromide (MgBr2) and/or magnesium ethoxide (Mg(OEt)2). THF solutions containing a single solute, MgBr2 or Mg(OEt)2, show no visible faradaic current based on Mg deposition and/or dissolution. However, the electrolyte system containing both solutes, MgBr2 + Mg(OEt)2/THF, gives a reversible current response of Mg deposition and dissolution. The ionic structure of the electrolyte system containing the binary solute was examined by infrared (IR) spectroscopy and density functional theory (DFT) calculations. It was confirmed that MgBr2 and Mg(OEt)2 are coordinated (solvated) with THF molecules to form an EtOsbnd Mgsbnd Br·4THF complex. The DFT calculations also suggest the possible formation of μ-complexes for the MgBr2/Mg(OEt)2 binary system in THF. The voltammetric responses at the Pt electrode indicate low overpotential and high coulombic efficiency for Mg deposition and dissolution in THF-based solutions containing suitable molar ratios of MgBr2 and Mg(OEt)2. The constant-current charge-discharge cycling of Mg in MgBr2 + Mg(OEt)2/THF electrolyte also shows low overpotential and good cyclability over 300 cycles.

  12. Process for converting magnesium fluoride to calcium fluoride

    DOEpatents

    Kreuzmann, A.B.; Palmer, D.A.

    1984-12-21

    This invention is a process for the conversion of magnesium fluoride to calcium fluoride whereby magnesium fluoride is decomposed by heating in the presence of calcium carbonate, calcium oxide or calcium hydroxide. Magnesium fluoride is a by-product of the reduction of uranium tetrafluoride to form uranium metal and has no known commercial use, thus its production creates a significant storage problem. The advantage of this invention is that the quality of calcium fluoride produced is sufficient to be used in the industrial manufacture of anhydrous hydrogen fluoride, steel mill flux or ceramic applications.

  13. A magnesium-sodium hybrid battery with high operating voltage.

    PubMed

    Dong, Hui; Li, Yifei; Liang, Yanliang; Li, Guosheng; Sun, Cheng-Jun; Ren, Yang; Lu, Yuhao; Yao, Yan

    2016-07-01

    We report a high performance magnesium-sodium hybrid battery utilizing a magnesium-sodium dual-salt electrolyte, a magnesium anode, and a Berlin green cathode. The cell delivers an average discharge voltage of 2.2 V and a reversible capacity of 143 mA h g(-1). We also demonstrate the cell with an energy density of 135 W h kg(-1) and a high power density of up to 1.67 kW kg(-1). PMID:27284593

  14. Magnesium as a biodegradable and bioabsorbable material for medical implants

    NASA Astrophysics Data System (ADS)

    Brar, Harpreet S.; Platt, Manu O.; Sarntinoranont, Malisa; Martin, Peter I.; Manuel, Michele V.

    2009-09-01

    For many years, stainless steel, cobalt-chromium, and titanium alloys have been the primary biomaterials used for load-bearing applications. However, as the need for structural materials in temporary implant applications has grown, materials that provide short-term structural support and can be reabsorbed into the body after healing are being sought. Since traditional metallic biomaterials are typically biocompatible but not biodegradable, the potential for magnesium-based alloys in biomedical applications has gained more interest. This paper summarizes the history and current status of magnesium as a bioabsorbable implant material. Also discussed is the development of a magnesium-zinc-calcium alloy that demonstrates promising degradation behavior.

  15. Biodegradable Magnesium Alloys: A Review of Material Development and Applications

    PubMed Central

    Persaud-Sharma, Dharam; McGoron, Anthony

    2012-01-01

    Magnesium based alloys possess a natural ability to biodegrade due to corrosion when placed within aqueous substances, which is promising for cardiovascular and orthopedic medical device applications. These materials can serve as a temporary scaffold when placed in vivo, which is desirable for treatments when temporary supportive structures are required to assist in the wound healing process. The nature of these materials to degrade is attributed to the high oxidative corrosion rates of magnesium. In this review, a summary is presented for magnesium material development, biocorrosion characteristics, as well as a biological translation for these results. PMID:22408600

  16. A lightweight shape-memory magnesium alloy.

    PubMed

    Ogawa, Yukiko; Ando, Daisuke; Sutou, Yuji; Koike, Junichi

    2016-07-22

    Shape-memory alloys (SMAs), which display shape recovery upon heating, as well as superelasticity, offer many technological advantages in various applications. Those distinctive behaviors have been observed in many polycrystalline alloy systems such as nickel titantium (TiNi)-, copper-, iron-, nickel-, cobalt-, and Ti-based alloys but not in lightweight alloys such as magnesium (Mg) and aluminum alloys. Here we present a Mg SMA showing superelasticity of 4.4% at -150°C and shape recovery upon heating. The shape-memory properties are caused by reversible martensitic transformation. This Mg alloy includes lightweight scandium, and its density is about 2 grams per cubic centimeter, which is one-third less than that of practical TiNi SMAs. This finding raises the potential for development and application of lightweight SMAs across a number of industries. PMID:27463668

  17. Nanocomposite polymer electrolyte for rechargeable magnesium batteries

    SciTech Connect

    Shao, Yuyan; Rajput, Nav Nidhi; Hu, Jian Z.; Hu, Mary Y.; Liu, Tianbiao L.; Wei, Zhehao; Gu, Meng; Deng, Xuchu; Xu, Suochang; Han, Kee Sung; Wang, Jiulin; Nie, Zimin; Li, Guosheng; Zavadil, K.; Xiao, Jie; Wang, Chong M.; Henderson, Wesley A.; Zhang, Jiguang; Wang, Yong; Mueller, Karl T.; Persson, Kristin A.; Liu, Jun

    2014-12-28

    Nanocomposite polymer electrolytes present new opportunities for rechargeable magnesium batteries. However, few polymer electrolytes have demonstrated reversible Mg deposition/dissolution and those that have still contain volatile liquids such as tetrahydrofuran (THF). In this work, we report a nanocomposite polymer electrolyte based on poly(ethylene oxide) (PEO), Mg(BH4)2 and MgO nanoparticles for rechargeable Mg batteries. Cells with this electrolyte have a high coulombic efficiency of 98% for Mg plating/stripping and a high cycling stability. Through combined experiment-modeling investigations, a correlation between improved solvation of the salt and solvent chain length, chelation and oxygen denticity is established. Following the same trend, the nanocomposite polymer electrolyte is inferred to enhance the dissociation of the salt Mg(BH4)2 and thus improve the electrochemical performance. The insights and design metrics thus obtained may be used in nanocomposite electrolytes for other multivalent systems.

  18. Three-dimensional structures of magnesium nanopores

    NASA Astrophysics Data System (ADS)

    Wu, Shujing; Zheng, He; Jia, Shuangfeng; Sheng, Huaping; Cao, Fan; Li, Lei; Hu, Shuaishuai; Zhao, Penghui; Zhao, Dongshan; Wang, Jianbo

    2016-03-01

    The optimization of nanopore-based devices is closely related to the nanopore three-dimensional (3D) structures. In this paper, faceted nanopores were fabricated in magnesium (Mg) by aligning the electron beam (e-beam) along the [0001] direction. Detailed structural characterization by transmission electron microscopy reveals the existence of two 3D structures: hexagonal prism-shaped and hourglass-shaped 3D morphologies. Moreover, the 3D structures of nanopores are also found to depend on the widest nanopore diameter-to-thickness ratio (D/t). A plausible formation mechanism for different 3D structures is discussed. Our results incorporate a critical piece of information regarding the nanopore 3D structures in Mg and may serve as an important design guidance for the size- and shape-controllable fabrication of solid-state nanopores applying the e-beam sculpting technique.

  19. Bearing Tests of Magnesium-alloy Sheet

    NASA Technical Reports Server (NTRS)

    Sharp, W H; Moore, R L

    1943-01-01

    Bearing tests of AM-3S, AM-52S, and AM-C57S magnesium-alloy sheet in various thicknesses and tempers were made. Bearing yield and ultimate strengths were determined and compared for various edge distances and for various ratios of loading-pin diameter to sheet thickness. Tensile strengths were determined and ratios of average bearing yield and ultimate strength to tensile strength are given. The results of the tests indicated that ultimate bearing strengths increased with edge distances up to 1.5 to 2 times the diameter of the loading pin; that ultimate bearing strengths are a function of the ratio of pin diameter to sheet thickness; and that these properties are effected only slightly by increases in edge distance greater than 1.5 diameters.

  20. Laser glazing of lanthanum magnesium hexaaluminate

    NASA Astrophysics Data System (ADS)

    Zhang, Yanfei; Wang, Yaomin; Jarligo, Maria Ophelia; Zhong, Xinghua; Li, Qin; Cao, Xueqiang

    2008-08-01

    Lanthanum magnesium hexaalumminate (LMA) is an important candidate for thermal barrier coatings due to its thermal stability and low thermal conductivity. On the other hand, laser glazing method can potentially make thermal barrier coatings impermeable, resistant to corrosion on the surface and porous at bulk. LMA powder was synthesized at 1600 °C by solid-state reaction, pressed into tablet and laser glazed with a 5-kW continuous wave CO2 laser. Dendritic structures were observed on the surface of the laser-glazed specimen. The thicker the tablet, the easier the sample cracks. Cracking during laser glazing is attributed to the low thermal expansion coefficient and large thickness of the sample.

  1. A lightweight shape-memory magnesium alloy

    NASA Astrophysics Data System (ADS)

    Ogawa, Yukiko; Ando, Daisuke; Sutou, Yuji; Koike, Junichi

    2016-07-01

    Shape-memory alloys (SMAs), which display shape recovery upon heating, as well as superelasticity, offer many technological advantages in various applications. Those distinctive behaviors have been observed in many polycrystalline alloy systems such as nickel titantium (TiNi)–, copper-, iron-, nickel-, cobalt-, and Ti-based alloys but not in lightweight alloys such as magnesium (Mg) and aluminum alloys. Here we present a Mg SMA showing superelasticity of 4.4% at –150°C and shape recovery upon heating. The shape-memory properties are caused by reversible martensitic transformation. This Mg alloy includes lightweight scandium, and its density is about 2 grams per cubic centimeter, which is one-third less than that of practical TiNi SMAs. This finding raises the potential for development and application of lightweight SMAs across a number of industries.

  2. The magnesium chelation step in chlorophyll biosynthesis

    SciTech Connect

    Weinstein, J.

    1990-11-01

    In photosynthetic organisms, the biogenesis of energy transducing membranes requires the coordinate synthesis of prosthetic groups, proteins, and various lipids. Two of the major prosthetic groups, chlorophyll and heme, share a common biosynthetic pathway that diverges at the point of metal insertion into protoporphyrin IX (Proto). Insertion of iron leads to the formation of hemes, while insertion of magnesium is the first step unique to chlorophyll formation. This project is directed toward identifying the enzyme(s) responsible for magnesium chelation and elucidating the mechanism which regulates the flux of precursors through the branch point enzymes in isolated chloroplasts. Using intact chloroplasts from greening cucumber cotyledons, we have confirmed the ATP requirement for Mg-Proto formation. Use of non-hydrolyzable ATP analogs, uncouplers and ionophores has led to the conclusions that ATP hydrolysis is necessary, but that this hydrolysis is not linked to the requirement for membrane intactness by transmembrane ion gradients or electrical potentials. The enzyme(s) are flexible with respect to the porphyrin substrate specificity, accepting porphyrins with -vinyl, -ethyl, or -H substituents at the 2 and 4 positions. The activity increases approximately four-fold during greening. Possible physiological feedback inhibitors such as heme, protochlorophyllide, and chlorophyllide had no specific effect on the activity. The activity has now been assayed in barely, corn and peas, with the system from peas almost ten-fold more active than the cucumber system. Work is continuing in pea chloroplasts with the development of a continuous assay and investigation of the feasibility of characterizing an active, organelle-free preparation. 6 figs.

  3. Cell Adhesion on Surface-Functionalized Magnesium.

    PubMed

    Wagener, Victoria; Schilling, Achim; Mainka, Astrid; Hennig, Diana; Gerum, Richard; Kelch, Marie-Luise; Keim, Simon; Fabry, Ben; Virtanen, Sannakaisa

    2016-05-18

    The biocompatibility of commercially pure magnesium-based (cp Mg) biodegradable implants is compromised of strong hydrogen evolution and surface alkalization due to high initial corrosion rates of cp Mg in the physiological environment. To mitigate this problem, the addition of corrosion-retarding alloying elements or coating of implant surfaces has been suggested. In the following work, we explored the effect of organic coatings on long-term cell growth. cp Mg was coated with aminopropyltriehtoxysilane + vitamin C (AV), carbonyldiimidazole (CDI), or stearic acid (SA). All three coatings have been previously suggested to reduce initial corrosion and to enhance protein adsorption and hence cell adhesion on magnesium surfaces. Endothelial cells (DH1+/+) and osteosarcoma cells (MG63) were cultured on coated samples for up to 20 days. To quantify Mg corrosion, electrochemical impedance spectroscopy (EIS) was measured after 1, 3, and 5 days of cell culture. We also investigated the speed of initial cell spreading after seeding using fluorescently labeled fibroblasts (NIH/3T3). Hydrogen evolution after contact with cell culture medium was markedly decreased on AV- and SA-coated Mg compared to uncoated Mg. These coatings also showed improved cell adhesion and spreading after 24 h of culture comparable to tissue-treated plastic surfaces. On AV-coated cp Mg, a confluent layer of endothelial cells formed after 5 days and remained intact for up to 20 days. Together, these data demonstrate that surface coating with AV is a viable strategy for improving long-term biocompatibility of cp Mg-based implants. EIS measurements confirmed that the presence of a confluent cell layer increased the corrosion resistance. PMID:27089250

  4. Ionized magnesium in the planetary nebula NGC 7027

    NASA Technical Reports Server (NTRS)

    Evans, N. J., II; Natta, A.; Russell, R. W.; Wyant, J.; Beckwith, S.

    1984-01-01

    Observations of NGC 7027 are presented for six ionic lines: Mg(+3) (4.48 microns), Mg(+4) (5.61 microns), H(0) (4.05 and 7.46 microns), Ne(+5) (7.64 microns), and Ar(+5) (4.53 microns). The magnesium lines are consistent with the measurements of Russell, Soifer, and Willner (1977), and the hydrogen lines are consistent with the line strengths predicted from the radio flux. Upper limits were obtained for the neon and argon lines. The abundance of magnesium in the central part of the nebula is highly uncertain because the fine-structure collision strengths are poorly known. The strong gradient of magnesium abundance from the inner to the outer portions of the nebula derived by Pequignot and Stasinska (1980) could be an artifact of this uncertainty. A brief analysis of the effective stellar temperature derived from the magnesium line ratios is given.

  5. Magnesium-zinc reduction is effective in preparation of metals

    NASA Technical Reports Server (NTRS)

    Knighton, J. B.; Steuneberg, R. K.

    1967-01-01

    Uranium, thorium, and plutonium are effectively prepared by magnesium-zinc reduction, using uranium oxides, thorium dioxide, and plutonium dioxide as starting materials. This technique is also useful in performing reduction of metals such as zirconium and titanium.

  6. Sodium Picosulfate, Magnesium Oxide, and Anhydrous Citric Acid

    MedlinePlus

    Sodium picosulfate, magnesium oxide, and anhydrous citric acid combination powder is used to empty the colon (large intestine, bowel) before a colonoscopy (examination of the inside of the colon to check ...

  7. Design considerations for developing biodegradable and bioabsorbable magnesium implants

    NASA Astrophysics Data System (ADS)

    Brar, Harpreet S.; Keselowsky, Benjamin G.; Sarntinoranont, Malisa; Manuel, Michele V.

    2011-04-01

    The integration of biodegradable and bioabsorbable magnesium implants into the human body is a complex undertaking that faces major challenges. Candidate biomaterials must meet both engineering and physiological requirements to ensure the desired properties. Historically, efforts have been focused on the behavior of commercial magnesium alloys in biological environments and their resultant effect on cell-mediated processes. Developing causal relationships between alloy chemistry and microstructure, and effects as a cellular behavior can be a difficult and time-intensive process. A systems design approach has the power to provide significant contributions in the development of the next generation of magnesium alloy implants with controlled degradability, biocompatibility, and optimized mechanical properties, at reduced time and cost. This approach couples experimental research with theory and mechanistic modeling for the accelerated development of materials. The aim of this article is to enumerate this strategy, design considerations, and hurdles for developing new cast magnesium alloys for use as biodegradable implant materials.

  8. Magnesium for Treatment of Reversible Cerebral Vasoconstriction Syndrome

    PubMed Central

    Mijalski, Christina; Dakay, Katarina; Miller-Patterson, Cameron; Saad, Ali; Silver, Brian

    2015-01-01

    We describe 2 cases of reversible cerebral vasoconstriction syndrome (RCVS) with refractory headache aborted by intravenous magnesium. Case 1 is a 53-year-old woman with subarachnoid hemorrhage due to RCVS presented with refractory headache and persistent vasospasm, despite aggressive treatment with calcium channel blockers (CCBs) and systemic corticosteroids. Subsequently, she experienced dramatic relief of symptoms with intravenous magnesium therapy. She continued oral maintenance therapy and remained symptom free. Case 2 is a 71-year-old female with bilateral temporo-occipital infarcts due to RCVS, presented with refractory headache and persistent vasospasm on transcranial Doppler (TCD), despite aggressive treatment with CCBs. She experienced dramatic relief of symptoms with intravenous magnesium and resolution of vasospasm on TCD. Magnesium may be beneficial for the treatment of refractory headaches in patients with RCVS. Future studies are needed to determine whether it should be considered as a first-line agent. PMID:27366294

  9. Magnesium hydroxide nanoparticles synthesized in water-in-oil microemulsions.

    PubMed

    Wu, Jianming; Yan, Hong; Zhang, Xuehu; Wei, Liqiao; Liu, Xuguang; Xu, Bingshe

    2008-08-01

    Well-dispersed magnesium hydroxide nanoplatelets were synthesized by a simple water-in-oil (w/o) microemulsion process, blowing gaseous ammonia (NH(3)) into microemulsion zones solubilized by magnesium chloride solution (MgCl(2)). Typical quaternary microemulsions of Triton X-100/cyclohexane/n-hexanol/water were used as space-confining microreactors for the nucleation, growth, and crystallization of magnesium hydroxide nanoparticles. The obtained magnesium hydroxide was characterized by field-emission scanning electron microscopy (FESEM), high-resolution transmission election microscopy (HRTEM), X-ray powder diffraction (XRD), laser light scattering, Fourier transform infrared spectroscopy (FT-IR), and thermogravimetric analysis-differential scanning calorimetry (TGA-DSC). The mole ratio of water to surfactant (omega(0)) played an important role in the sizes of micelles and nanoparticles, increasing with the increase of omega(0). The compatibility and dispersibility of nanoparticles obtained from reverse micelles were improved in the organic phase. PMID:18511061

  10. Sodium Picosulfate, Magnesium Oxide, and Anhydrous Citric Acid

    MedlinePlus

    ... picosulfate, magnesium oxide, and anhydrous citric acid combination powder is used to empty the colon (large intestine, ... oxide and anhydrous citric acid combine when the powder is mixed with water to form a medication ...

  11. Topologically ordered magnesium-biopolymer hybrid composite structures.

    PubMed

    Oosterbeek, Reece N; Seal, Christopher K; Staiger, Mark P; Hyland, Margaret M

    2015-01-01

    Magnesium and its alloys are intriguing as possible biodegradable biomaterials due to their unique combination of biodegradability and high specific mechanical properties. However, uncontrolled biodegradation of magnesium during implantation remains a major challenge in spite of the use of alloying and protective coatings. In this study, a hybrid composite structure of magnesium metal and a biopolymer was fabricated as an alternative approach to control the corrosion rate of magnesium. A multistep process that combines metal foam production and injection molding was developed to create a hybrid composite structure that is topologically ordered in all three dimensions. Preliminary investigations of the mechanical properties and corrosion behavior exhibited by the hybrid Mg-polymer composite structures suggest a new potential approach to the development of Mg-based biomedical devices. PMID:24659540

  12. POURING IRON FROM ELECTRIC FURNACE INTO BULL LADLE AFTER MAGNESIUM ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    POURING IRON FROM ELECTRIC FURNACE INTO BULL LADLE AFTER MAGNESIUM HAD BEEN ADDED TO GENERATE DUCTILE IRON WHEN IT COOLS IN THE MOLD. - Southern Ductile Casting Company, Casting, 2217 Carolina Avenue, Bessemer, Jefferson County, AL

  13. Physicochemical action of potassium-magnesium citrate in nephrolithiasis

    NASA Technical Reports Server (NTRS)

    Pak, C. Y.; Koenig, K.; Khan, R.; Haynes, S.; Padalino, P.

    1992-01-01

    Effect of potassium-magnesium citrate on urinary biochemistry and crystallization of stone-forming salts was compared with that of potassium citrate at same dose of potassium in five normal subjects and five patients with calcium nephrolithiasis. Compared to the placebo phase, urinary pH rose significantly from 6.06 +/- 0.27 to 6.48 +/- 0.36 (mean +/- SD, p less than 0.0167) during treatment with potassium citrate (50 mEq/day for 7 days) and to 6.68 +/- 0.31 during therapy with potassium-magnesium citrate (containing 49 mEq K, 24.5 mEq Mg, and 73.5 mEq citrate per day). Urinary pH was significantly higher during potassium-magnesium citrate than during potassium citrate therapy. Thus, the amount of undissociated uric acid declined from 118 +/- 61 mg/day during the placebo phase to 68 +/- 54 mg/day during potassium citrate treatment and, more prominently, to 41 +/- 46 mg/day during potassium-magnesium citrate therapy. Urinary magnesium rose significantly from 102 +/- 25 to 146 +/- 37 mg/day during potassium-magnesium citrate therapy but not during potassium citrate therapy. Urinary citrate rose more prominently during potassium-magnesium citrate therapy (to 1027 +/- 478 mg/day from 638 +/- 252 mg/day) than during potassium citrate treatment (to 932 +/- 297 mg/day). Consequently, urinary saturation (activity product) of calcium oxalate declined significantly (from 1.49 x 10(-8) to 1.03 x 10(-8) M2) during potassium-magnesium citrate therapy and marginally (to 1.14 x 10(-8) M2) during potassium citrate therapy.(ABSTRACT TRUNCATED AT 250 WORDS).

  14. Formation of chemically bonded ceramics with magnesium dihydrogen phosphate binder

    DOEpatents

    Wagh, Arun S.; Jeong, Seung-Young

    2004-08-17

    A new method for combining magnesium oxide, MgO, and magnesium dihydrogen phosphate to form an inexpensive compactible ceramic to stabilize very low solubility metal oxides, ashes, swarfs, and other iron or metal-based additives, to create products and waste forms which can be poured or dye cast, and to reinforce and strengthen the ceramics formed by the addition of fibers to the initial ceramic mixture.

  15. Eosinophilic hepatitis after ingestion of choline magnesium trisalicylate.

    PubMed

    Nadkarni, M M; Peller, C A; Retig, J

    1992-01-01

    Choline magnesium trisalicylate is a non-acetylated salicylate used widely as a nonsteroidal anti-inflammatory drug. Although mild transient hepatotoxicity associated with aspirin and other salicylates has been well documented, most commonly with high-dose treatment for rheumatologic disorders 112), we report a case of severe hypersensitivity hepatitis with striking tissue and peripheral eosinophilia after ingestion of choline magnesium trisalicylate. PMID:1728115

  16. Magnesium sulfate protects fetal skin from intrauterine ischemia reperfusion injury.

    PubMed

    Kaptanoglu, Asli F; Arca, Turkan; Kilinc, Kamer

    2012-09-01

    Intrauterine ischemia-reperfusion (I/R) injury in fetus occurs with multifactorial pathogenesis and results with multiorgan injury including skin. Magnesium has widespread use in obstetric practice. Inn addition to magnesium's tocolytic and neuroprotective properties, it also has free radical reducing effects. The aim of the present study was to demonstrate whether magnesium sulfate could have protective effect on fetal rat skin in intrauterine ischemia-reperfusion (I/R) injury. Fetal skin ischemia was induced by clamping the utero-ovarian arteries bilaterally for 30 min, and reperfusion was achieved by removing the clamps for 60 min in 19-day pregnant rats. Magnesium Sulfate (MgSO(4)) was given to pregnant rats 20 min before I/R injury at the dose of 600 mg/kg in magnesium treatment group. No ischemia reperfusion was applied to control and sham-operated groups. Lipid peroxidation from the skin tissues was determined as thiobarbituric acid reactive substances (TBARS). Myeloperoxidase (MPO) activity was determined for neutrophil activation. The results showed that the levels of TBARS and MPO increased significantly in the fetal rat skin after I/R injury compared to control group. Levels of TBARS and MPO were significantly lower than those of I/R group in Magnesium-treated group. In conclusion, intrauterine ischemia-reperfusion may produce considerable fetal skin injury. Increased TBARS and MPO activity can be inhibited by magnesium treatment. This suggests that magnesium treatment may have protective effect on fetal rat skin in intrauterine I/R injury. PMID:22310734

  17. Column strength of magnesium alloy AM-57S

    NASA Technical Reports Server (NTRS)

    Holt, M

    1942-01-01

    Tests were made to determine the column strength of extruded magnesium alloy AM-57S. Column specimens were tested with round ends and with flat ends. It was found that the compressive properties should be used in computations for column strengths rather than the tensile properties because the compressive yield strength was approximately one-half the tensile yield strength. A formula for the column strength of magnesium alloy AM-57S is given.

  18. Lithium and magnesium isotopes fractionation by zone melting

    NASA Astrophysics Data System (ADS)

    Akimov, D. V.; Egorov, N. B.; Dyachenko, A. N.; Pustovalova, M. P.; Podoinikov, I. R.

    2016-06-01

    The process of changing isotopic composition of the lithium and magnesium salts was studied by using the process of zone melting. It was founded in the paper that the process of separation of the lithium isotopes is more effective than for magnesium isotopes when the conditions of process were the same. The coefficients of isotopes separation were calculated and have the next value: α = 1.006 for 26Mg isotope and α = 1.0022 for 6Li isotope.

  19. In vivo decomposition study of coated magnesium alloys

    NASA Astrophysics Data System (ADS)

    White, Desiree; Piersma, Tyler; Lecronier, David; Cheng, Xingguo; Rabago-Smith, Montserrat

    2010-04-01

    In the last decade, magnesium has resurged as an important biomaterial. Its mechanical properties are very similar to natural bone, and it degrades in vivo to non toxic substances. Unfortunately, corrosion of pure magnesium in vivo is rapid, thus coated alloys that decrease its corrosion could be used as implants in orthopedics. This presentation will describe the degradation results in cell cultures and in rats.

  20. In vitro decomposition study of coated magnesium alloys

    NASA Astrophysics Data System (ADS)

    Piersma, Tyler; White, Desiree; Cheng, Xinggou; Rabago-Smith, Montserrat; Lecronier, David

    2010-04-01

    In the last decade, magnesium has resurged as an important biomaterial. It's mechanical properties are very similar to natural bone, and it degrades in vivo to non toxic substances. Unfortunately, corrosion of pure magnesium in vivo is rapid, thus coated alloys that decrease it's corrosion could be used as implants in orthopedics. This presentation will describe the degradation results in a simulated body fluid (SBF).

  1. Al-TiH2 Composite Foams Magnesium Alloy

    NASA Astrophysics Data System (ADS)

    Prasada Rao, A. K.; Oh, Y. S.; Ain, W. Q.; A, Azhari; Basri, S. N.; Kim, N. J.

    2016-02-01

    The work presented here in describes the synthesis of aluminum based titanium-hydride particulate composite by casting method and its foaming behavior of magnesium alloy. Results obtained indicate that the Al-10TiH2 composite can be synthesized successfully by casting method. Further, results also reveal that closed-cell magnesium alloy foam can be synthesized by using Al-10TiH2 composite as a foaming agent.

  2. Multi-functional magnesium alloys containing interstitial oxygen atoms

    NASA Astrophysics Data System (ADS)

    Kang, H.; Choi, H. J.; Kang, S. W.; Shin, S. E.; Choi, G. S.; Bae, D. H.

    2016-03-01

    A new class of magnesium alloys has been developed by dissolving large amounts of oxygen atoms into a magnesium lattice (Mg-O alloys). The oxygen atoms are supplied by decomposing titanium dioxide nanoparticles in a magnesium melt at 720 °C the titanium is then completely separated out from the magnesium melt after solidification. The dissolved oxygen atoms are located at the octahedral sites of magnesium, which expand the magnesium lattice. These alloys possess ionic and metallic bonding characteristics, providing outstanding mechanical and functional properties. A Mg-O-Al casting alloy made in this fashion shows superior mechanical performance, chemical resistance to corrosion, and thermal conductivity. Furthermore, a similar Mg-O-Zn wrought alloy shows high elongation to failure (>50%) at room temperature, because the alloy plastically deforms with only multiple slips in the sub-micrometer grains (<300 nm) surrounding the larger grains (~15 μm). The metal/non-metal interstitial alloys are expected to open a new paradigm in commercial alloy design.

  3. Production and Refining of Magnesium Metal from Turkey Originating Dolomite

    NASA Astrophysics Data System (ADS)

    Demiray, Yeliz; Yücel, Onuralp

    2012-06-01

    In this study crown magnesium produced from Turkish calcined dolomite by the Pigeon Process was refined and corrosion tests were applied. By using factsage thermodynamic program metalothermic reduction behavior of magnesium oxide and silicate formation structure during this reaction were investigated. After thermodynamic studies were completed, calcination of dolomite and it's metalothermic reduction at temperatures of 1473 K, 1523 K and within a vacuum (varied from 20 to 200 Pa) and refining of crown magnesium was studied. Different flux compositions consisting of MgCl2, KCl, CaCl2, MgO, CaF2, NaCl, and SiO2 with and without B2O3 additions were selected for the refining process. These tests were carried out at 963 K for 15, 30 and 45 minutes setting time. Considerable amount of iron was transferred into the sludge phase and its amount decreased from 0.08% to 0.027%. This refined magnesium was suitable for the production of various magnesium alloys. As a result of decreasing iron content, minimum corrosion rate of refined magnesium was obtained 2.35 g/m2/day. The results are compared with previous studies.

  4. Synthesis of magnesium aluminate spinel by periclase and alumina chlorination

    SciTech Connect

    Orosco, Pablo; Barbosa, Lucía; Ruiz, María del Carmen

    2014-11-15

    Highlights: • Use of chlorination for the synthesis of magnesium aluminate spinel. • The reagents used were alumina, periclase and chlorine. • Isothermal and non-isothermal assays were performed in air and Cl{sub 2}–N{sub 2} flows. • The chlorination produced magnesium aluminate spinel at 700 °C. • Selectivity of the chlorination reaction to obtain spinel is very high. - Abstract: A pyrometallurgical route for the synthesis of magnesium aluminate spinel by thermal treatment of a mechanical mixture containing 29 wt% MgO (periclase) and 71 wt% Al{sub 2}O{sub 3} (alumina) in chlorine atmosphere was developed and the results were compared with those obtained by calcining the same mixture of oxides in air atmosphere. Isothermal and non-isothermal assays were performed in an experimental piece of equipment adapted to work in corrosive atmospheres. Both reagents and products were analyzed by differential thermal analysis (DTA), X-ray diffraction (XRD) and X-ray fluorescence (XRF). Thermal treatment in Cl{sub 2} atmosphere of the MgO–Al{sub 2}O{sub 3} mixture produces magnesium aluminate spinel at 700 °C, while in air, magnesium spinel is generated at 930 °C. The synthesis reaction of magnesium aluminate spinel was complete at 800 °C.

  5. The relationship between maternal serum magnesium level and preterm birth.

    PubMed

    Khani, S; Shokrzadeh, M; Karamoddini, P K; Shahmohammadi, S

    2010-04-01

    The aim of this study was to evaluate the relationship between maternal serum magnesium levels and preterm birth. This Nested case-control study carried out on 20 with preterm birth and 20 women at term birth at Imam Khomeini Hospital in Sari/Iran in 2008. The women with singleton gestation and intact fetal membrane suspected to preterm labor (case group), 10 cc blood samples were drawn into syringes and sent to laboratory of the hospital immediately. Sampling for control group was same as the case group. These samples recognized as control group just as birth occurring after week 37. Finally, serum magnesium level measured. Data analyzed using chi2, t-test and OR (Odd's Ratio). There was a relationship between the number of prenatal visits (p = 0.008) and stressful events associated with preterm birth (p < 0.02). Serum magnesium level was associated with preterm birth OR = 4.75, CI 95% = (0.48-46.91), Sensitivity, specificity, positive and negative predictive value of serum magnesium for preterm birth was 95, 50, 66.5 and 83.33%, respectively. Although, there was a correlation between serum magnesium levels and preterm birth, due to methodology of the study, a cohort study with the same cut off point and supplementation of magnesium in RTC studies is recommended. PMID:20836289

  6. Multi-functional magnesium alloys containing interstitial oxygen atoms.

    PubMed

    Kang, H; Choi, H J; Kang, S W; Shin, S E; Choi, G S; Bae, D H

    2016-01-01

    A new class of magnesium alloys has been developed by dissolving large amounts of oxygen atoms into a magnesium lattice (Mg-O alloys). The oxygen atoms are supplied by decomposing titanium dioxide nanoparticles in a magnesium melt at 720 °C; the titanium is then completely separated out from the magnesium melt after solidification. The dissolved oxygen atoms are located at the octahedral sites of magnesium, which expand the magnesium lattice. These alloys possess ionic and metallic bonding characteristics, providing outstanding mechanical and functional properties. A Mg-O-Al casting alloy made in this fashion shows superior mechanical performance, chemical resistance to corrosion, and thermal conductivity. Furthermore, a similar Mg-O-Zn wrought alloy shows high elongation to failure (>50%) at room temperature, because the alloy plastically deforms with only multiple slips in the sub-micrometer grains (<300 nm) surrounding the larger grains (~15 μm). The metal/non-metal interstitial alloys are expected to open a new paradigm in commercial alloy design. PMID:26976372

  7. Sol - Gel synthesis and characterization of magnesium peroxide nanoparticles

    NASA Astrophysics Data System (ADS)

    Jaison, J.; Ashok raja, C.; Balakumar, S.; Chan, Y. S.

    2015-04-01

    Magnesium peroxide is an excellent source of oxygen in agriculture applications, for instance it is used in waste management as a material for soil bioremediation to remove contaminants from polluted underground water, biological wastes treatment to break down hydrocarbon, etc. In the present study, sol-gel synthesis of magnesium peroxide (MgO2) nanoparticles is reported. Magnesium peroxide is odourless; fine peroxide which releases oxygen when reacts with water. During the sol-gel synthesis, the magnesium malonate intermediate is formed which was then calcinated to obtain MgO2 nanoparticles. The synthesized nanoparticles were characterized using Thermo gravimetric -Differential Thermal Analysis (TG- DTA), X-Ray Diffraction studies (XRD) and High Resolution Transmission Electron Microscope (HRTEM). Our study provides a clear insight that the formation of magnesium malonate during the synthesis was due to the reaction between magnesium acetate, oxalic acid and ethanol. In our study, we can conclude that the calcination temperature has a strong influence on particle size, morphology, monodispersity and the chemistry of the particles.

  8. Multi-functional magnesium alloys containing interstitial oxygen atoms

    PubMed Central

    Kang, H.; Choi, H. J.; Kang, S. W.; Shin, S. E.; Choi, G. S.; Bae, D. H.

    2016-01-01

    A new class of magnesium alloys has been developed by dissolving large amounts of oxygen atoms into a magnesium lattice (Mg-O alloys). The oxygen atoms are supplied by decomposing titanium dioxide nanoparticles in a magnesium melt at 720 °C; the titanium is then completely separated out from the magnesium melt after solidification. The dissolved oxygen atoms are located at the octahedral sites of magnesium, which expand the magnesium lattice. These alloys possess ionic and metallic bonding characteristics, providing outstanding mechanical and functional properties. A Mg-O-Al casting alloy made in this fashion shows superior mechanical performance, chemical resistance to corrosion, and thermal conductivity. Furthermore, a similar Mg-O-Zn wrought alloy shows high elongation to failure (>50%) at room temperature, because the alloy plastically deforms with only multiple slips in the sub-micrometer grains (<300 nm) surrounding the larger grains (~15 μm). The metal/non-metal interstitial alloys are expected to open a new paradigm in commercial alloy design. PMID:26976372

  9. Understanding the effects of disorder in magnesium diboride films and development of novel magnesium diboride based Josephson junctions

    NASA Astrophysics Data System (ADS)

    Gandikota, Raghuram

    Magnesium diboride, with a critical temperature of 39 Kelvin, is an unusual superconductor with two conduction bands (pi and sigma) in which carriers couple with lattice vibrations resulting in two superconducting gaps. The properties of magnesium diboride films and related multi-layers were respectively explored on two fronts: (i) to understand the role that disorder in magnesium diboride plays in making it a practicable material for magnet applications; and, (ii) to design and fabricate magnesium diboride-based Josephson junctions for fast-switching circuits. The role that the two bands play in establishing upper critical field and resistivity is quantitatively shown by modifying disorder in magnesium diboride through controlled introduction of point defects in films with different levels of as-grown disorder, followed by annealing. Point defects were introduced iteratively by irradiation using a helium ion beam, and their effects on critical temperature, resistivity, and upper critical field of magnesium diboride films were studied. Results suggest that resistivity and upper critical field are determined by scattering in pi and sigma bands, respectively, and they can be uncorrelated when the scattering rates in the two bands are altered independently. A common correlation was found between the upper critical field (at zero Kelvin) and critical temperature of magnesium diboride samples made in several forms and disordered by different means. As an alternate means of introducing disorder, oxygen was incorporated in magnesium diboride films and the effects on the normal and superconducting properties were analyzed. Magnesium diboride films required for Josephson junctions were grown in a vacuum chamber using evaporative sources. The potential of native and thermal oxides formed on magnesium diboride, for use as tunnel barriers, was explored. The barrier height and thickness of these oxides were obtained by studying conductance-voltage characteristics of junctions

  10. Recycling of Magnesium Alloy Employing Refining and Solid Oxide Membrane (SOM) Electrolysis

    NASA Astrophysics Data System (ADS)

    Guan, Xiaofei; Zink, Peter A.; Pal, Uday B.; Powell, Adam C.

    2013-04-01

    Pure magnesium was recycled from partially oxidized 50.5 wt pct Mg-Al scrap alloy and AZ91 Mg alloy (9 wt pct Al, 1 wt pct Zn). Refining experiments were performed using a eutectic mixture of MgF2-CaF2 molten salt (flux). During the experiments, potentiodynamic scans were performed to determine the electrorefining potentials for magnesium dissolution and magnesium bubble nucleation in the flux. The measured electrorefining potential for magnesium bubble nucleation increased over time as the magnesium content inside the magnesium alloy decreased. Potentiostatic holds and electrochemical impedance spectroscopy were employed to measure the electronic and ionic resistances of the flux. The electronic resistivity of the flux varied inversely with the magnesium solubility. Up to 100 pct of the magnesium was refined from the Mg-Al scrap alloy by dissolving magnesium and its oxide into the flux followed by argon-assisted evaporation of dissolved magnesium and subsequently condensing the magnesium vapor. Solid oxide membrane electrolysis was also employed in the system to enable additional magnesium recovery from magnesium oxide in the partially oxidized Mg-Al scrap. In an experiment employing AZ91 Mg alloy, only the refining step was carried out. The calculated refining yield of magnesium from the AZ91 alloy was near 100 pct.

  11. [Photometric method of the detection of magnesium oxide in the working zone air after using magnesium caustic dust].

    PubMed

    Putilina, O N; Makarevskaia, V V

    1991-01-01

    The contributors proposed a new highly sensitive selective technique of magnesium oxide detection, based on the Congo red and salicylic acid reaction. The minimal detection level is 0.25 mg of magnesium oxide in the analyzed sample volume. The range of measured concentrations varies from 0.01 to 0.4 mcg/ml. The express technique is simple and selective with Ca (II), Fe (III), AI (III). PMID:2060814

  12. Structure and dynamics of the hydrated magnesium ion and of the solvated magnesium carbonates: insights from first principles simulations.

    PubMed

    Di Tommaso, Devis; de Leeuw, Nora H

    2010-01-28

    We report first principles molecular dynamics simulations based on the density functional theory and the Car-Parrinello method to study the structures and dynamics of the hydrated Mg(2+) ion and of the solvated MgHCO(3)(+) and MgCO(3) complexes in aqueous solution. According to these simulations, the first hydration shell of the hydrated magnesium ion consists of six water molecules, whereas in the solvated magnesium bicarbonate and magnesium carbonate complexes the Mg(2+) is mostly five-coordinated, which indicates that when coordinated to magnesium the HCO(3)(-) and CO(3)(2-) anions reduce its the coordination sphere. Our simulations show that the structures of the most stable monomers of magnesium bi-carbonate and magnesium carbonate in solution are Mg[eta(1)-HCO(3)](H(2)O)(4)(+) and Mg[eta(1)-CO(3)](H(2)O)(4), i.e. the preferred hydration number is four, while the (bi-)carbonate is coordinated to the magnesium in a monodentate mode. The analysis of the exchange processes of the water molecules in the first and second hydration shell of Mg(2+) shows that the HCO(3)(-) or CO(3)(2-) ligands affect the dynamics of the magnesium coordination spheres by making its hydration shell more "labile". Furthermore, molecular dynamics simulations of the non-associated Mg(2+)/Cl(-) pair in water suggest that, despite negligible differences in the coordination spheres of Mg(2+), the chloride anion has a significant influence on the water exchange rates in the second hydration shell of Mg(2+). PMID:20066374

  13. Removal of organic magnesium in coccolithophore calcite

    NASA Astrophysics Data System (ADS)

    Blanco-Ameijeiras, S.; Lebrato, M.; Stoll, H. M.; Iglesias-Rodriguez, M. D.; Méndez-Vicente, A.; Sett, S.; Müller, M. N.; Oschlies, A.; Schulz, K. G.

    2012-07-01

    Coccolithophore calcite refers to the plates of calcium carbonate (CaCO3) produced by the calcifying phytoplankton, coccolithophores. The empirical study of the elemental composition has a great potential in the development of paleoproxies. However, the difficulties to separate coccolithophore carbonates from organic phases hamper the investigation of coccoliths magnesium to calcium ratios (Mg/Ca) in biogeochemical studies. Magnesium (Mg) is found in organic molecules in the cells at concentrations up to 400 times higher than in inorganically precipitated calcite in present-day seawater. The aim of this study was to optimize a reliable procedure for organic Mg removal from coccolithophore samples to ensure reproducibility in measurements of inorganic Mg in calcite. Two baseline methods comprising organic matter oxidations with (1) bleach and (2) hydrogen peroxide (H2O2) were tested on synthetic pellets, prepared by mixing reagent grade CaCO3 with organic matter from the non-calcifying marine algae Chlorella autotrophica and measured with an ICP-AES (inductively coupled plasma-atomic emission spectrometer). Our results show that treatments with a reductive solution [using hydroxylamine-hydrochloride (NH2OH·HCl + NH4OH)] followed by three consecutive oxidations (using H2O2) yielded the best cleaning efficiencies, removing >99% of organic Mg in 24 h. P/Ca and Fe/Ca were used as indicators for organic contamination in the treated material. The optimized protocol was tested in dried coccolithophore pellets from batch cultures of Emiliania huxleyi, Calcidiscus leptoporus and Gephyrocapsa oceanica. Mg/Ca of treated coccolithophores were 0.151 ± 0.018, 0.220 ± 0.040, and 0.064 ± 0.023 mmol/mol, respectively. Comparison with Mg/Ca literature coccolith values, suggests a tight dependence on modern seawater Mg/Ca, which changes as a consequence of different seawater origins (<10%). The reliable determination of Mg/Ca and Sr/Ca, and the low levels of organic contamination

  14. Axoplasmic free magnesium levels and magnesium extrusion from squid giant axons.

    PubMed

    De Weer, P

    1976-08-01

    The free magnesium concentration in the axoplasm of the giant axon of the squid, Loligo pealei, was estimated by exploting the known sensitivity of the sodium pump to intracellular Mg2+ levels. The Mg-citrate buffer which, when injected into the axon, resulted in no change in sodium efflux was in equilibrium with a Mg2+ level of about 3--4 mM. Optimal [Mg2+] for the sodium pump is somewhat higher. Total magnesium content of axoplasm was 6.7 mmol/kg, and that of hemolymph was 44 mM. The rate coefficient for 28Mg efflux was about 2 X 10(-3) min-u for a 500-mum axon at 22-25degreesC, with a very high temperature coefficient (Q10=4-5). This efflux is inhibited 95% by injection of apyrase and 75% by removal of external sodium, and seems unaffected by membrane potential or potassium ions. Increased intracellular ADP levels do not affect Mg efflux nor its requirement for Na+/o, but extracellularl magnesium ions do. Activation of 28Mg efflux by Na+/o follows hyperbolic kinetics, with Mg2+/o reducing the affinity of the system for Na+/o. Lanthanum and D600 reversibly inhibit Mg efflux. In the absence of both Na+ and Mg2+, but not in their presence, removal of Ca2+ from the seawater vastly increased 28Mg efflux; this efflux was also strongly inhibited by lanthanum. A small (10(-14) mol cm-2) extra Mg efflux accompanies the conduction of an action potential. PMID:956769

  15. Severe selective magnesium malabsorption: tests of tolerance of oral magnesium supplements.

    PubMed

    Mettey, R; Guillard, O; Merle, P; Maillet-Picker, F

    1990-12-01

    Since his birth, we have been monitoring a 12-year-old boy suffering from selective severe magnesium malabsorption. Our essential problem is to prepare a form of galena with acceptable taste, tolerated by the digestive tract and well absorbed; also, the carrier compound must not cause short- or long-term side effects. An additional factor is the steadily increasing need for magnesium from 1 mmol/kg.d at 1 year to 14 mmol/kg.d at present age (345 mg/kg.d). The galena forms currently on sale were, with the exception of lactate and pyrollidone carboxylate, immediately rejected since they contain insufficient Mg2+. Following short trials resulting in diarrhoea, the other two preparations were also rejected. We then constituted - and also abandoned - our own galena compounds: aspartate (bitterness), aspartate + glycerophosphate (GLP) (bitterness), glutamate + GLP ('Chinese restaurant syndrome' and fear of the long term toxic effect of the glutamate), gluconate (excessive volume: 11/1 proportion with Mg2+). A recent test featuring GLP of Mg 40 g + cocoa butter 40 g + cocoa 10 g, brought about vomiting and diarrhoea, and was not adequately absorbed. The best tolerated formula is: Mg GLP 21.33 g; saccharose 6 g; aspartam 1 g; gelatin 0.5 g; citric acid, conserving agent, fruity aroma; water: qs 100 g. Such composition yields a caramel cream absorbed in five small portions, at a daily quantity of 375 g (80 g GLP Mg, 10 g Mg2+). Vitamin B6, which promotes intestinal absorption of magnesium, must be given separately in tablet form at a dose of 1 g/d, since it causes nausea if it is included in the Mg preparation.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2132677

  16. Layered materials with improved magnesium intercalation for rechargeable magnesium ion cells

    DOEpatents

    Doe, Robert Ellis; Downie, Craig Michael; Fischer, Christopher; Lane, George Hamilton; Morgan, Dane; Nevin, Josh; Ceder, Gerbrand; Persson, Kristin Aslaug; Eaglesham, David

    2016-07-26

    Electrochemical devices which incorporate cathode materials that include layered crystalline compounds for which a structural modification has been achieved which increases the diffusion rate of multi-valent ions into and out of the cathode materials. Examples in which the layer spacing of the layered electrode materials is modified to have a specific spacing range such that the spacing is optimal for diffusion of magnesium ions are presented. An electrochemical cell comprised of a positive intercalation electrode, a negative metal electrode, and a separator impregnated with a nonaqueous electrolyte solution containing multi-valent ions and arranged between the positive electrode and the negative electrode active material is described.

  17. Layered materials with improved magnesium intercalation for rechargeable magnesium ion cells

    DOEpatents

    Doe, Robert E.; Downie, Craig M.; Fischer, Christopher; Lane, George H.; Morgan, Dane; Nevin, Josh; Ceder, Gerbrand; Persson, Kristin A.; Eaglesham, David

    2016-01-19

    Electrochemical devices which incorporate cathode materials that include layered crystalline compounds for which a structural modification has been achieved which increases the diffusion rate of multi-valent ions into and out of the cathode materials. Examples in which the layer spacing of the layered electrode materials is modified to have a specific spacing range such that the spacing is optimal for diffusion of magnesium ions are presented. An electrochemical cell comprised of a positive intercalation electrode, a negative metal electrode, and a separator impregnated with a nonaqueous electrolyte solution containing multi-valent ions and arranged between the positive electrode and the negative electrode active material is described.

  18. Layered materials with improved magnesium intercalation for rechargeable magnesium ion cells

    SciTech Connect

    Doe, Robert Ellis; Downie, Craig Michael; Fischer, Christopher; Lane, George Hamilton; Morgan, Dane; Nevin, Josh; Ceder, Gerbrand; Persson, Kristin Aslaug; Eaglesham, David

    2015-10-27

    Electrochemical devices which incorporate cathode materials that include layered crystalline compounds for which a structural modification has been achieved which increases the diffusion rate of multi-valent ions into and out of the cathode materials. Examples in which the layer spacing of the layered electrode materials is modified to have a specific spacing range such that the spacing is optimal for diffusion of magnesium ions are presented. An electrochemical cell comprised of a positive intercalation electrode, a negative metal electrode, and a separator impregnated with a nonaqeuous electrolyte solution containing multi-valent ions and arranged between the positive electrode and the negative electrode active material is described.

  19. Magnesium Toxicity-Induced Ileus in a Postpartum Patient Treated for Preeclampsia With Magnesium Sulphate

    PubMed Central

    Al-Shoha, Mohammad; Klair, Jagpal S.; Girotra, Mohit

    2015-01-01

    Hypermagnesemia is a rare and under-recognized cause of paralytic ileus. We report a case of a 21-year-old primigravida who was managed aggressively for preeclampsia and presented with postpartum paralytic ileus. Detailed history was employed to consider hypermagnesemia-induced ileus as the working diagnosis, and the patient improved with correction of the electrolyte imbalance. Hypermagnesemia-induced lethargy, decreased reflexes, muscle weakness, flaccid paralysis, respiratory muscle paralysis, and cardiac arrest are well-described; however, intestinal smooth muscle dysfunction leading to paralytic ileus has never been reported in the setting of magnesium use for peripartum preeclampsia management. PMID:26203447

  20. Corrosion prevention of magnesium surfaces via surface conversion treatments using ionic liquids

    DOEpatents

    Qu, Jun; Luo, Huimin

    2016-09-06

    A method for conversion coating a magnesium-containing surface, the method comprising contacting the magnesium-containing surface with an ionic liquid compound under conditions that result in decomposition of the ionic liquid compound to produce a conversion coated magnesium-containing surface having a substantially improved corrosion resistance relative to the magnesium-containing surface before said conversion coating. Also described are the resulting conversion-coated magnesium-containing surface, as well as mechanical components and devices containing the conversion-coated magnesium-containing surface.

  1. The Phase Stabilities of Magnesium Hydroxychlorides

    NASA Astrophysics Data System (ADS)

    de Bakker, Jan; LaMarre, Joshua; Peacey, John; Davis, Boyd

    2012-08-01

    This work presents experimental determinations of oxide phase stabilities in the MgCl2-MgO-H2O system. Magnesium hydroxychlorides are compounds with the overall stoichiometry xMgO· yMgCl2· zH2O, which form from the reaction of MgO with MgCl2 brines. They have historically been of importance as the components of Sorel cements; they also have a central role in proposed flowsheets for chloride leaching of laterite nickel ores (among others) and treatment of waste liquors from carnallite processing. A phase diagram of the MgCl2-MgO-H2O system is presented, incorporating both this investigation's results and the values from the literature. Thermochemical values of the 2-form and 3-form hydroxychlorides are estimated from the phase diagram. In addition, a scanning electron microscopy (SEM) micrograph of the hydroxychloride precipitate is presented. The highlights of this article are as follows: Precipitates of stoichiometry xMgO· yMgCl2· zH2O were obtained by adding MgO to MgCl2 solutions.

  2. Fatigue Properties of Cast Magnesium Wheels

    NASA Astrophysics Data System (ADS)

    Li, Zhenming; Luo, Alan A.; Wang, Qigui; Peng, Liming; Zhang, Peng

    2016-05-01

    This paper investigates the fatigue properties and deformation behavior of a newly developed Mg-2.96Nd-0.21Zn-0.39Zr magnesium alloy wheel in both as-cast and T6 conditions. Compared with the as-cast alloy, the T6-treated alloy shows a significant increase in fatigue strength and cyclic stress amplitude. This is believed to be attributed to the change of defect type from porosity to oxides and the increased matrix strength in the T6 (peak-aged) condition. For the as-cast alloy wheel, fatigue failure mainly originated from the cast defects including porosity, oxide film, and inclusion at or near the sample surface. In the T6-treated alloy, however, oxides and inclusions or slip bands initiate the fatigue cracks. Solution treatment appears to reduce or eliminate the shrinkage porosity because of grain growth and dissolution of as-cast eutectic phases in the grain boundaries. The cyclic stress amplitude of the as-cast alloy increases with increasing the number of cycles, while the T6-treated alloy shows cyclic softening after the stress reaches a maximum value. The Coffin-Manson law and Basquin equation can be used to evaluate the life of low cycle fatigue. The developed long crack model and multi-scale fatigue (MSF) models can be used to predict high-cycle fatigue life of the Mg-2.96Nd-0.21Zn-0.39Zr alloys with or without casting defects.

  3. Meteoric Magnesium Ions in the Martian Atmosphere

    NASA Technical Reports Server (NTRS)

    Pesnell, William Dean; Grebowsky, Joseph

    1999-01-01

    From a thorough modeling of the altitude profile of meteoritic ionization in the Martian atmosphere we deduce that a persistent layer of magnesium ions should exist around an altitude of 70 km. Based on current estimates of the meteoroid mass flux density, a peak ion density of about 10(exp 4) ions/cm is predicted. Allowing for the uncertainties in all of the model parameters, this value is probably within an order of magnitude of the correct density. Of these parameters, the peak density is most sensitive to the meteoroid mass flux density which directly determines the ablated line density into a source function for Mg. Unlike the terrestrial case, where the metallic ion production is dominated by charge-exchange of the deposited neutral Mg with the ambient ions, Mg+ in the Martian atmosphere is produced predominantly by photoionization. The low ultraviolet absorption of the Martian atmosphere makes Mars an excellent laboratory in which to study meteoric ablation. Resonance lines not seen in the spectra of terrestrial meteors may be visible to a surface observatory in the Martian highlands.

  4. Weakening of ice by magnesium perchlorate hydrate

    USGS Publications Warehouse

    Lenferinka, Hendrick J.; Durhama, William B.; Sternb, Laura A.; Patharec, Asmin V.

    2013-01-01

    We show that perchlorate hydrates, which have been detected at high circumpolar martian latitudes, have a dramatic effect upon the rheological behavior of polycrystalline water ice under conditions applicable to the North Polar Layered Deposits (NPLD). We conducted subsolidus creep tests on mixtures of ice and magnesium perchlorate hydrate, Mg(ClO4)2·6H2O (MP6), of 0.02, 0.05, 0.10, and 0.47 volume fraction MP6. We found these mixtures to be increasingly weak with increasing MP6 content. For mixtures with ⩽0.10 volume fraction MP6, we resolved a stress exponent of n ≈ 2 at low stresses transitioning to n ≈ 4 above 10 MPa. Scanning electron microscopy of deformed specimens revealed MP6 to be distributed as an interconnected film between ice grains. These results suggest that grain boundary sliding (GBS) may be enhanced with respect to pure ice. As the enhancement of GBS is expected in polycrystalline aggregates containing a few percent melt or otherwise weak material distributed along grain boundaries, the observed n ≈ 2 is consistent with the mutual accommodation of basal slip and GBS. If ice containing trace concentrations of MP6 is also much weaker than pure ice at low stresses, flow in the NPLD could be significantly enhanced, particularly at the warmer basal temperatures associated with higher martian obliquities.

  5. Potential automotive uses of wrought magnesium alloys

    SciTech Connect

    Gaines, L.; Cuenca, R.; Wu, S.; Stodolsky, F. |

    1996-06-01

    Vehicle weight reduction is one of the major means available to improve automotive fuel efficiency. High-strength steels, aluminum (Al), and polymers are already being used to reduce weight significantly, but substantial additional reductions could be achieved by greater use of low-density magnesium (Mg) and its alloys. Mg alloys are currently used in relatively small quantities for auto parts, generally limited to die castings (e.g., housings). Argonne National Laboratory`s Center for Transportation Research has performed a study for the Lightweight Materials Program within DOE`s Office of Transportation Materials to evaluate the suitability of wrought Mg and its alloys to replace steel/aluminum for automotive structural and sheet applications. Mg sheet could be used in body nonstructural and semi-structural applications, while extrusions could be used in such structural applications as spaceframes. This study identifies high cost as the major barrier to greatly increased Mg use in autos. Two technical R and D areas, novel reduction technology and better hot-forming technology, could enable major cost reductions.

  6. Status of Research on Magnesium Oxide Backfill

    SciTech Connect

    PAPENGUTH,HANS W.; KRUMHANSL,JAMES L.; BYNUM,R. VANN; WANG,YIFENG; KELLY,JOHN W.; ANDERSON,HOWARD; NOWAK,E. JAMES

    2000-07-31

    For the WIPP, chemical and physical characteristics of MgO suggest it to be the most beneficial backfill choice, particularly because it has the ability to buffer the aqueous chemical conditions to control actinide volubility. In the current experimental program, the authors are developing a technical basis for taking credit for the complete set of attributes of MgO in geochemical, hydrogeological, and geomechanical technical areas, resulting in an improved conceptual model for the WIPP such as the following. Water uptake by MgO will delay the development of mobile actinides and gas generation by microbes and corrosion. Reduced gas generation will reduce or even eliminate spallings releases. As MgO hydrates, it swells, reducing porosity and permeability, which will inhibit gas flow in the repository, in turn reducing spallings releases. Hydration will also result in a self-sealing mechanism by which water uptake and swelling of MgO adjacent to a groundwater seep cuts off further seepage. Reaction with some groundwaters will produce cementitious materials, which will help to cement waste particles or produce a cohesive solid mass. Larger particles are less likely to be entrained in a spallings release. If sufficient water eventually accumulates in a repository to support microbial gas generation, magnesium carbonate cements will form; also producing good cohesion and strength.

  7. Weakening of ice by magnesium perchlorate hydrate

    NASA Astrophysics Data System (ADS)

    Lenferink, Hendrik J.; Durham, William B.; Stern, Laura A.; Pathare, Asmin V.

    2013-08-01

    We show that perchlorate hydrates, which have been detected at high circumpolar martian latitudes, have a dramatic effect upon the rheological behavior of polycrystalline water ice under conditions applicable to the North Polar Layered Deposits (NPLD). We conducted subsolidus creep tests on mixtures of ice and magnesium perchlorate hydrate, Mg(ClO4)2·6H2O (MP6), of 0.02, 0.05, 0.10, and 0.47 volume fraction MP6. We found these mixtures to be increasingly weak with increasing MP6 content. For mixtures with ⩽0.10 volume fraction MP6, we resolved a stress exponent of n ≈ 2 at low stresses transitioning to n ≈ 4 above 10 MPa. Scanning electron microscopy of deformed specimens revealed MP6 to be distributed as an interconnected film between ice grains. These results suggest that grain boundary sliding (GBS) may be enhanced with respect to pure ice. As the enhancement of GBS is expected in polycrystalline aggregates containing a few percent melt or otherwise weak material distributed along grain boundaries, the observed n ≈ 2 is consistent with the mutual accommodation of basal slip and GBS. If ice containing trace concentrations of MP6 is also much weaker than pure ice at low stresses, flow in the NPLD could be significantly enhanced, particularly at the warmer basal temperatures associated with higher martian obliquities.

  8. Photoelectric effects in magnesium aluminum spinel

    NASA Astrophysics Data System (ADS)

    Woosley, J. D.; Wood, C.; Sonder, E.; Weeks, R. A.

    1980-07-01

    The electronic and transport properties of magnesium aluminum spinel have been investigated photoelectrically. Photoemission of holes and electrons into spinel from metal contacts (Pt, Au, Ta, Mo, and Cu) has been used to determine barrier heights. From this information, as well as vacuum-uv photoconductivity data, we have obtained the following energy-band parameters: The Fermi level lies ~3 eV below the bottom of the conduction band, which in turn is located ~ 2 eV below the vacuum level, and the band gap is ~ 9 eV. Photoemission was not observed from graphite electrodes which form Ohmic contacts. Electron, neutron, or gamma irradiation produced three photoconductivity bands of half-width ~0.5 eV, with peaks at 4.5, 5.0, and 5.5 eV. The three bands, equally spaced in energy, may be associated with the same center. The optical absorption band of the F center is in the same region of the spectrum; however, its shape did not correspond to the observed photoconductivity spectrum. A lower limit of 10-6 cm2/V has been calculated for the μτ product of the photogenerated charge carriers.

  9. Fatigue Properties of Cast Magnesium Wheels

    NASA Astrophysics Data System (ADS)

    Li, Zhenming; Luo, Alan A.; Wang, Qigui; Peng, Liming; Zhang, Peng

    2016-08-01

    This paper investigates the fatigue properties and deformation behavior of a newly developed Mg-2.96Nd-0.21Zn-0.39Zr magnesium alloy wheel in both as-cast and T6 conditions. Compared with the as-cast alloy, the T6-treated alloy shows a significant increase in fatigue strength and cyclic stress amplitude. This is believed to be attributed to the change of defect type from porosity to oxides and the increased matrix strength in the T6 (peak-aged) condition. For the as-cast alloy wheel, fatigue failure mainly originated from the cast defects including porosity, oxide film, and inclusion at or near the sample surface. In the T6-treated alloy, however, oxides and inclusions or slip bands initiate the fatigue cracks. Solution treatment appears to reduce or eliminate the shrinkage porosity because of grain growth and dissolution of as-cast eutectic phases in the grain boundaries. The cyclic stress amplitude of the as-cast alloy increases with increasing the number of cycles, while the T6-treated alloy shows cyclic softening after the stress reaches a maximum value. The Coffin-Manson law and Basquin equation can be used to evaluate the life of low cycle fatigue. The developed long crack model and multi-scale fatigue (MSF) models can be used to predict high-cycle fatigue life of the Mg-2.96Nd-0.21Zn-0.39Zr alloys with or without casting defects.

  10. The magnesium chelation step in chlorophyll biosynthesis

    SciTech Connect

    Weinstein, J.D.

    1991-01-01

    The biogenesis of energy transducing membranes requires the coordinate synthesis of prosthetic groups, proteins and lipids. Two of the major prosthetic groups, chlorophyll and heme, share a common biosynthetic pathway that diverges at the point of metal insertion into protoporphyrin IX. Insertion of iron leads to heme, while insertion of magnesium leads to chlorophyll. The Mg-chelatase from intact cucumber chloroplasts has been characterized with regard to substrate specificity, regulation, ATP requirement, and a requirement for intact chloroplasts. Mg-chelatase was isolated from maize, barley and peas and characterized in order to circumvent the intact chloroplast requirement of cucumber Mg-chelatase. Pea Mg-chelatase activity is higher than cucumber Mg-chelatase activity, and lacks the requirement for intact chloroplasts. Studies on isolated pea Mg-chelatase have shown more cofactors are required for the reaction than are seen with ferrochelatase, indicating a greater opportunity for regulatory control of this pathway. Two of the cofactors are proteins, and there appears to be a requirement for a protease-sensitive component which is outside the outer envelope. We are developing a continuous spectrophotometric assay for Mg-chelatase activity, and an assay for free heme which has shown heme efflux from intact chloroplasts. 18 refs. (MHB)

  11. Nanoconfined water in magnesium-rich phyllosilicates.

    SciTech Connect

    Nenoff, Tina Maria; Durkin, Justin S.; Daemen, Luke L.; Ockwig, Nathan W.; Cygan, Randall Timothy; Greathouse, Jeffery A.

    2009-10-01

    Inelastic neutron scattering, density functional theory, ab initio molecular dynamics, and classical molecular dynamics were used to examine the behavior of nanoconfined water in palygorskite and sepiolite. These complementary methods provide a strong basis to illustrate and correlate the significant differences observed in the spectroscopic signatures of water in two unique clay minerals. Distortions of silicate tetrahedra in the smaller-pore palygorskite exhibit a limited number of hydrogen bonds having relatively short bond lengths. In contrast, without the distorted silicate tetrahedra, an increased number of hydrogen bonds are observed in the larger-pore sepiolite with corresponding longer bond distances. Because there is more hydrogen bonding at the pore interface in sepiolite than in palygorskite, we expect librational modes to have higher overall frequencies (i.e., more restricted rotational motions); experimental neutron scattering data clearly illustrates this shift in spectroscopic signatures. Distortions of the silicate tetrahedra in these minerals effectively disrupts hydrogen bonding patterns at the silicate-water interface, and this has a greater impact on the dynamical behavior of nanoconfined water than the actual size of the pore or the presence of coordinatively-unsaturated magnesium edge sites.

  12. K-SHELL PHOTOABSORPTION OF MAGNESIUM IONS

    SciTech Connect

    Hasoğlu, M. F.; Abdel-Naby, Sh. A.; Gatuzz, E.; Mendoza, C.; García, J.; Kallman, T. R.; Gorczyca, T. W.

    2014-09-01

    X-ray photoabsorption cross sections have been computed for all magnesium ions with three or more electrons using the R-matrix method. A comparison with other available data for Mg II-Mg X shows good qualitative agreement in the resultant resonance shapes. However, for the lower ionization stages, and for singly ionized Mg II in particular, the previous R-matrix results overestimate the K-edge position due to the neglect of important orbital relaxation effects, and a global shift downward in photon energy of those cross sections is therefore warranted. We have found that the cross sections for Mg I and Mg II are further complicated by the M-shell (n = 3) occupancy. As a result, the treatment of spectator Auger decay of 1s → np resonances using a method based on multichannel quantum defect theory and an optical potential becomes problematic, making it necessary to implement an alternative, approximate treatment of Auger decay for neutral Mg I. The new cross sections are used to fit the Mg K edge in XMM-Newton spectra of the low-mass X-ray binary GS 1826-238, where most of the interstellar Mg is found to be in ionized form.

  13. Overview: recognizing the problem of magnesium deficiency

    SciTech Connect

    Seelig, M.S.

    1988-01-01

    The magnesium content of the usual American diet is less than the recommended dietary allowance. Excesses of some macro- and micro-nutrients interact with Mg, increasing its requirements. Marginal deficiency of Mg is not associated with hypomagnesemia, is not characterized by typical manifestations, as is thus difficult to diagnose. Serum or plasma Mg levels are held within narrow limits unless tissue levels are very low, or renal function is poor. Vulnerability to Mg deficiency increases during growth and development, pregnancy, when under physical or psychological stress, and during illness or its treatment that interferes with absorption or causes loss of Mg. Evidence of biochemical changes of early Mg deficiency is rarely sought, although the roles of Mg in many enzyme systems are recognized. The effects of Mg deficiency on metabolism, even in disorders caused by vitamin dependencies in which Mg is a co-factor, are largely unexplored. Deficiency of Mg is diagnosed confidently when the laboratory reports hypomagnesemia in patients with convulsions or arrhythmias. Without these signs, Mg levels are not often ordered, even in the presence of neuromuscular irritability such as respond to Mg repletion. Because Mg supplementation or Mg-sparing drugs protect against premature or ectopic heart beats and sudden death, to which diuretic-treated hypertensive patients are at risk, it is increasingly being advised that their Mg status be determined.

  14. Local and systemic tolerability of magnesium sulphate for tocolysis.

    PubMed

    Zygmunt, M; Heilmann, L; Berg, C; Wallwiener, D; Grischke, E; Münstedt, K; Spindler, A; Lang, U

    2003-04-25

    An open-label, randomised, parallel-group, study was conducted in three study centres in women with premature labor and indication for a single agent intravenous tocolysis therapy with magnesium sulphate. The aim of this study was to examine the local and general tolerability and side-effects of magnesium sulphate for tocolysis. Furthermore, we tested the tolerability of a ready-for-use magnesium solution. No measurements of efficacy were performed during this study. Initially, patients received a loading dose of 4.0 g magnesium sulphate administered over 30 min. Thereafter, a continuous intravenous infusion of 1-2 g magnesium sulphate per hour up to 21 days was given. Venous score (Maddox), vital signs, adverse events as well as general tolerability (assessed by investigator and patients) and blood parameters were assessed. We showed good local and systemic tolerability of high dose magnesium sulphate for tocolysis. Only seven patients (15%) were withdrawn from the study prematurely due to minor adverse events. Potential serious complications of MgSO(4) such as respiratory arrest or clinically relevant respiratory depression were not observed. The most frequently reported local adverse events were injection site pain, itching, erythema, swelling, induration and palpable venous cord. The most common systemic adverse events considered to be possibly related to the study drugs involved the nervous system (dizziness) followed by the digestive system (nausea, constipation). Systolic and diastolic blood pressure changed only slightly during the treatment. Respiratory rate and body temperature remained stable also. Toxic magnesium levels (>2.5 mmol/l) were not observed. The assessment of the clinical investigators with regard to tolerability was very good or good in 72.5% of the patients. The introduction of the ready-to-use solution has the advantage of eliminating the need to mix the solution prior to administration. This means a lower risk of overdose and

  15. Biodegradable magnesium nanoparticle-enhanced laser hyperthermia therapy

    PubMed Central

    Wang, Qian; Xie, Liping; He, Zhizhu; Di, Derui; Liu, Jing

    2012-01-01

    Background Recently, nanoparticles have been demonstrated to have tremendous merit in terms of improving the treatment specificity and thermal ablation effect on tumors. However, the potential toxicity and long-term side effects caused by the introduced nanoparticles and by expelling them out of the body following surgery remain a significant challenge. Here, we propose for the first time to directly adopt magnesium nanoparticles as the heating enhancer in laser thermal ablation to avoid these problems by making full use of the perfect biodegradable properties of this specific material. Methods To better understand the new nano “green” hyperthermia modality, we evaluated the effects of magnesium nanoparticles on the temperature transients inside the human body subject to laser interstitial heating. Further, we experimentally investigated the heating enhancement effects of magnesium nanoparticles on a group of biological samples: oil, egg white, egg yolk, in vitro pig tissues, and the in vivo hind leg of rabbit when subjected to laser irradiation. Results Both the theoretical simulations and experimental measurements demonstrated that the target tissues injected with magnesium nanoparticles reached much higher temperatures than tissues without magnesium nanoparticles. This revealed the enhancing behavior of the new nanohyperthermia method. Conclusion Given the unique features of magnesium nanoparticles – their complete biological safety and ability to enhance heating – which most other advanced metal nanoparticles do not possess, the use of magnesium nanoparticles in hyperthermia therapy offers an important “green” nanomedicine modality for treating tumors. This method has the potential to be used in clinics in the near future. PMID:22956872

  16. [Magnesium, calcium and potassium: "no one was born alone"].

    PubMed

    Rapisarda, Francesco; Portale, Grazia; Ferrario, Silvia; Sessa, Concetto; Aliotta, Roberta; Zanoli, Luca; Fatuzzo, Pasquale

    2016-01-01

    In contrast to other ions, magnesium is treated as an orphan by the body: there are no hormones that have a substantial role in regulating urinary magnesium excretion, and bone, the principal reservoir of magnesium, does not readily exchange with circulating magnesium.The Mg ++ is often overlooked by physicians in the differential diagnosis because it is considered insignificant, but its role is crucial for cells function, first of all neurons and cardiomyocytes. A condition of hypocalcemia associated with hypokalemia, especially in the presence of chronic renal failure, should raise suspicion of a lack of Mg ++.We report the case of an old man of 77 year with kidney transplant for 13 years, treated with cyclosporine, and sodium mycophenolate and steroid who, for about a month, accused impaired balance and walking instability, who fell accidentally down with wrist fracture.Blood tests showed hypocalcemia and hypokalemia, and so we required dosage of serum and urinary magnesium. A significant reduction in the ion plasma concentration was seen, associated to a fraction of excretion inappropriately high in relation to the degree of hypomagnesemia.The cause of this important renal loss is likely attributable to cyclosporine, a drug that has as a side effect the inhibition of the reabsorption of Mg ++ in the distal convoluted tubule. then, oral supplementation was started (244 mg of Mg ++ ion / day), with subsequent normalization, after a few days, not only of magnesiemia, but also in serum calcium and potassium levels, and improvement of neurological symptoms.Hypomagnesaemia is common in patients with renal transplantation in therapy with calcineurin inhibitors ICN, due to the effects of such drugs on the TRPM6 transporter present in the kidney distal convoluted tubule. To prevent complications caused by chronic and severe depletion of magnesium in this particular population, we recommend periodic monitoring of magnesium plasma levels. PMID:26913745

  17. Atomic layer deposition of magnesium fluoride via bis(ethylcyclopentadienyl)magnesium and anhydrous hydrogen fluoride

    SciTech Connect

    Hennessy, John Jewell, April D.; Greer, Frank; Lee, Michael C.; Nikzad, Shouleh

    2015-01-15

    A new process has been developed to deposit magnesium fluoride (MgF{sub 2}) thin films via atomic layer deposition (ALD) for use as optical coatings in the ultraviolet. MgF{sub 2} was deposited in a showerhead style ALD reactor using bis(ethylcyclopentadienyl)magnesium and anhydrous hydrogen fluoride (HF) as precursors at substrate temperatures from 100 to 250 °C. The use of HF was observed to result in improved morphology and reduced impurity content compared to other reported MgF{sub 2} ALD approaches that use metal fluoride precursors as the fluorine-containing chemistry. Characterization of these films has been performed using spectroscopic ellipsometry, atomic force microscopy, and x-ray photoelectron spectroscopy for material deposited on silicon substrates. Films at all substrate temperatures were transparent at wavelengths down to 190 nm and the low deposition temperature combined with low surface roughness makes these coatings good candidates for a variety of optical applications in the far ultraviolet.

  18. High Strength and Thermally Stable Nanostructured Magnesium Alloys and Nanocomposites

    NASA Astrophysics Data System (ADS)

    Chang, Yuan-Wei

    Magnesium and its alloys are currently in the spotlight of global research because of the need to limit energy consumption and reduce the environmental impact. In particular, their low densities compared to other structural metals make them a very attractive alternative in the automobile and aerospace industries. However, their low strength compared to other structural materials (e.g. Al and steels) has limited their widespread application. This dissertation presents the results of developing and investigation of a high strength nanostructured magnesium-aluminum alloy and composite. The nanostructured magnesium alloy is prepared by cryomilling and consolidated by spark-plasma-sintering. Focused ion beam is used to prepare micropillars with different diameters ranging from 1.5 to 8 mum and micro-compression test is conducted by nanoindenter in order to evaluate the mechanical properties. The yield strength obtained in the present study is around three times higher than conventional magnesium alloys (120 MPa vs. 370 MPa). The yield strength of the nanostructured magnesium alloy is further improved through hot extrusion, resulting in a yield strength of 550 MPa and an ultimate strength of 580 MPa. The nanostructured magnesium alloy exhibits a strong size-dependence, and a significant improvement in strength is observed when the pillar diameter is reduced to below 3.5 mum. The deformation mechanisms of the compressed pillars were characterized using transmission electron microscopy. The size-induced strengthening is attributed to a less number of dislocation sources along with a higher activity of non-basal deformation mechanisms. We have also developed a high strength and thermally stable nanostructured magnesium composite by adding diamantane. A yield strength of 500 MPa is achieved, moreover, excellent thermal stability is demonstrated in the magnesium alloy containing diamantanes. The strength and grain size are thermally stable after annealing at 400°C for 100

  19. Effects of calcium and magnesium on strontium distribution coefficients

    USGS Publications Warehouse

    Bunde, R.L.; Rosentreter, J.J.; Liszewski, M.J.; Hemming, C.H.; Welhan, J.

    1997-01-01

    The effects of calcium and magnesium on the distribution of strontium between a surficial sediment and simulated wastewater solutions were measured as part of an investigation to determine strontium transport properties of surficial sediment at the Idaho National Engineering Laboratory (INEL), Idaho. The investigation was conducted by the U.S. Geological Survey and Idaho State University, in cooperation with the U.S. Department of Energy. Batch experimental techniques were used to determine strontium linear sorption isotherms and distribution coefficients (K(d)'s) using simulated wastewater solutions prepared at pH 8.0??0.1 with variable concentrations of calcium and magnesium. Strontium linear sorption isotherm K(d)'s ranged from 12??1 to 85??3 ml/g, increasing as the concentration of calcium and magnesium decreased. The concentration of sorbed strontium and the percentage of strontium retained by the sediment were correlated to aqueous concentrations of strontium, calcium, and magnesium. The effect of these cation concentrations on strontium sorption was quantified using multivariate least-squares regression techniques. Analysis of data from these experiments indicates that increased concentrations of calcium and magnesium in wastewater discharged to waste disposal ponds at the INEL increases the availability of strontium for transport beneath the ponds by decreasing strontium sorption to the surficial sediment.

  20. Antenatal magnesium sulfate: Neuro-protection for preterm infants.

    PubMed

    Oddie, S; Tuffnell, D J; McGuire, W

    2015-11-01

    The neuro-protective effect of antenatal magnesium sulfate on very preterm infants has been demonstrated in good-quality randomised controlled trials and meta-analyses. Magnesium administered prior to preterm delivery crosses over to the foetal circulation and acts via several pathways to reduce perinatal neuronal damage. Meta-analysis of the trial data indicates that antenatal magnesium sulfate reduces the risk of cerebral palsy by one-third, and results in one fewer case in every 50 women treated. Treatment is associated with discomfort and flushing in some women, but maternal side-effects are mostly transient and manageable. Magnesium sulfate has also been found to be without any serious adverse consequences in newborn infants. Consensus recommendations and guidelines have been developed and implemented internationally, and endorsed by the UK Royal College of Obstetricians and Gynaecologists. However, magnesium sulfate for neuro-protection of very preterm infants has not yet become established widely in UK practice. Paediatricians, neonatologists and advocacy groups for preterm infants and their families could contribute to raising awareness and engage in dissemination activities and implementation initiatives to develop local protocols for adoption of this safe, effective and cost-effective intervention to reduce the burden of cerebral palsy in children born very preterm. PMID:25896966

  1. [Effect of magnesium ions on heat denaturation of DNA].

    PubMed

    Blagoĭ, Iu P; Sorokin, V A; Valeev, V A; Khomenko, S A; Gladchenko, G O

    1977-01-01

    The dependence of animal DNA denaturation on magnesium ion concentration has been studied in the range (10(-6)--10(-1) M with sodium ion content of 10(-3) and 10(-2) M. Special attention has been given to the effect of multivalent metallic impurities bound to DNA. An increase of DNA thermal stability has been shown to occur in the magnesium concentration rage of 10(-6)--10(-4) M. At concentrations exceeding 10(-3) M the T M begins to decrease. The dependence of the DNA melting range on magnesium ion concentration has a maximum at approximately 10(-5) M Mg2+. At low magnesium and sodium ion concentrations a strong asymmetry of the melting curves has been observed. This effect can be described in terms of the melting theory for DNA complexed with small molecules and is explained by magnesium ion redistribution from the denatured portions of DNA to native ones. The method for calculation of melting curves in the DNA-ligand system has been proposed. Studies of thermal denaturation parameters have been shown to be an effective method for the estimation of binding constants of ligands to native and denatured DNA. PMID:618320

  2. Deleterious effects of magnesium intoxication upon the domestic broiler chick

    SciTech Connect

    Lee, S.R.

    1984-01-01

    Dietary levels of 0.6 to 0.8% magnesium in a corn-soy basal were rachitogenic. These rickets appeared most like phosphorus deficiency. Bone Ca/P ratios were numerically quite low implying a lack of transformation from amorphous calcium phosphate to hydroxyapatite. Bone alkaline phosphatase activity was elevated. Additional dietary phosphorus ameliorated, but could not overcome the rachitogenic effects of magnesium. Tibial dyschondroplasia (TD), induced by elevated dietary P, was decreased by high levels of dietary Mg, but with no decrease in plasma phosphorus. Anticoccidial ionophores fed in conjunction with a moderate dietary challenge of Mg (0.48%) produced no clear changes in plasma calcium or Mg, but did interact to reduce body weight. The diarrhea caused by magnesium intoxication is not due to hyperosmotic loads of Mg per se. Rather, Cl was observed to be the major ionic constituent of the gut osmotic load implying different gut ionic fluxes in control versus magnesium intoxicated chicks. These data imply that the cathartic action of Mg is due to hypersecretion of the gut. Effects mediated or modified by the CNS changed in magnesium intoxicated chicks. Such chicks appeared cold and stayed near the heat. When startled, they exhibited extreme avoidance behavior and seizures similar to epilepsy and/or Cl deficiency. Brain tissue Mg content did not concomitantly increase. Whether these effects are due to central signals is unclear.

  3. USAMP Magnesium Powertrain Cast Components: Fundamental research summary

    NASA Astrophysics Data System (ADS)

    Beals, Randy S.; Liu, Zi-Kui; Wayne Jones, J.; Mallick, P. K.; Emadi, Daryoush; Schwam, David; Powell, Bob R.

    2007-08-01

    The Magnesium Powertrain Cast Components (MPCC) Project is an effort, jointly sponsored by the U.S. Department of Energy and the U.S. Automotive Materials Partnership (USAMP), to demonstrate the readiness of magnesium for use in powertrain applications by testing a set the magnesium-intensive engines which were designed, cast, and assembled. A second MPCC goal is to promote new and strengthen existing magnesium scientific research in North America. The project investigated several of the newly developed high-temperature (creep-resistant) magnesium alloys, which will potentially experience service conditions in the temperature range of 150-200°C and about 50-110 MPa in stresses (typical powertrain). However, the mechanical and physical behaviors of these new alloys are not fully understood. This article outlines MPCC-supported fundamental scientific research into the workings of these new alloys. The areas of research are: phase equilibrium and computational thermodynamics, creep deformation mechanisms, corrosion, hot tearing, and alloy recycling.

  4. Susceptibility of metallic magnesium implants to bacterial biofilm infections.

    PubMed

    Rahim, Muhammad Imran; Rohde, Manfred; Rais, Bushra; Seitz, Jan-Marten; Mueller, Peter P

    2016-06-01

    Magnesium alloys have promising mechanical and biological properties as biodegradable medical implant materials for temporary applications during bone healing or as vascular stents. Whereas conventional implants are prone to colonization by treatment resistant microbial biofilms in which bacteria are embedded in a protective matrix, magnesium alloys have been reported to act antibacterial in vitro. To permit a basic assessment of antibacterial properties of implant materials in vivo an economic but robust animal model was established. Subcutaneous magnesium implants were inoculated with bacteria in a mouse model. Contrary to the expectations, bacterial activity was enhanced and prolonged in the presence of magnesium implants. Systemic antibiotic treatments were remarkably ineffective, which is a typical property of bacterial biofilms. Biofilm formation was further supported by electron microscopic analyses that revealed highly dense bacterial populations and evidence for the presence of extracellular matrix material. Bacterial agglomerates could be detected not only on the implant surface but also at a limited distance in the peri-implant tissue. Therefore, precautions may be necessary to minimize risks of metallic magnesium-containing implants in prospective clinical applications. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 1489-1499, 2016. PMID:26860452

  5. Preparation and characterization of magnesium borate for special glass

    NASA Astrophysics Data System (ADS)

    Dou, Lishuang; Zhong, Jianchu; Wang, Hongzhi

    2010-05-01

    Magnesium borate with a variety of B2O3/MgO molar ratios, which can be applied for special glass, has been prepared through the reaction of light-burned magnesia with boric acid by a hydrothermal method. The effects of the B2O3/MgO molar ratio of raw materials, reaction time, temperature and liquid to solid ratio (ml g-1) on the synthetic product are investigated. The XRD and TG-DTG analyses indicate that the prepared magnesium borate is a mixture of magnesium hexaborate hydrate and ascharite. The results show that high B2O3/MgO molar ratios of raw materials and low reaction liquid-solid ratios favour the product with a high B2O3/MgO molar ratio and vice versa. There exists free MgO in the product when the reaction temperature is below 140 °C or the reaction time is not enough, because of the incomplete reaction of magnesium oxide with boric acid. The process of fractional crystallization for the magnesium borate mixture is also discussed.

  6. Formability Analysis of Magnesium Alloy Sheet Bulging Using FE Simulation

    NASA Astrophysics Data System (ADS)

    Mac Donald, B. J.; Hunt, D.; Yoshihara, S.; Manabe, K.

    2007-05-01

    There is currently much focus on the application of magnesium alloys to automotive structural components. This has arisen due to the positive environmental aspects associated with use of magnesium alloys such as weight reduction and recycling potential. In recent years many researchers have focused on the application of various forming processes to magnesium alloys. Magnesium alloys would seem highly suitable for sheet forming due to high N and r values, however, in application their formability has been inferior to, for example, aluminium alloys. It has thus been concluded that, when dealing with magnesium alloys, it is difficult to predict formability based on material properties. In order to improve formability and forming accuracy when using Mg alloys it is necessary to build a database and inference system which could decide the optimal forming parameters for complex automotive components. Currently not enough data is available to build such a database due to the limited number of studies available in literature. In this study an experimental analysis of hemispherical bulge forming at elevated temperature was undertaken in order to evaluate formability and hence build a database for forming process design. A finite element model based on the experiment has been built and validated against the experimental results. A ductile failure criterion has been integrated with the FE model and is used to predict the onset of failure. This paper discusses the development and validation of the finite element model with the ductile failure criterion and presents results from the experimental tests and FE simulations.

  7. Size Effect on Magnesium Alloy Castings

    NASA Astrophysics Data System (ADS)

    Li, Zhenming; Wang, Qigui; Luo, Alan A.; Zhang, Peng; Peng, Liming

    2016-03-01

    The effect of grain size on tensile and fatigue properties has been investigated in cast Mg alloys of Mg-2.98Nd-0.19Zn (1530 μm) and Mg-2.99Nd-0.2Zn-0.51Zr (41 μm). The difference between RB and push-pull fatigue testing was also evaluated in both alloys. The NZ30K05-T6 alloy shows much better tensile strengths (increased by 246 pct in YS and 159 pct in UTS) and fatigue strength (improved by ~80 pct) in comparison with NZ30-T6 alloy. RB fatigue testing results in higher fatigue strength compared with push-pull fatigue testing, mainly due to the stress/strain gradient in the RB specimen cross section. The material with coarse grains could be hardened more in the cyclic loading condition than in the monotonic loading condition, corresponding to the lower σ f and the higher σ f/σ b or σ f/σ 0.2 ratio compared to the materials with fine grains. The fatigue crack initiation sites and failure mechanism are mainly determined by the applied stress/strain amplitude. In LCF, fatigue failure mainly originates from the PSBs within the surface or subsurface grains of the samples. In HCF, cyclic deformation and damage irreversibly caused by environment-assisted cyclic slip is the crucial factor to influence the fatigue crack. The Coffin-Manson law and Basquin equation, and the developed MSF models and fatigue strength models can be used to predict fatigue lives and fatigue strengths of cast magnesium alloys.

  8. Hydrothermal synthesis of hexagonal magnesium hydroxide nanoflakes

    SciTech Connect

    Wang, Qiang; Li, Chunhong; Guo, Ming; Sun, Lingna; Hu, Changwen

    2014-03-01

    Graphical abstract: Hexagonal Mg(OH){sub 2} nanoflakes were synthesized via hydrothermal method in the presence of PEG-20,000. Results show that PEG-20,000 plays an important role in the formation of this kind of nanostructure. The SAED patterns taken from the different positions on a single hexagonal Mg(OH){sub 2} nanoflake yielded different crystalline structures. The structure of the nanoflakes are polycrystalline and the probable formation mechanism of Mg(OH){sub 2} nanoflakes is discussed. - Highlights: • Hexagonal Mg(OH){sub 2} nanoflakes were synthesized via hydrothermal method. • PEG-20,000 plays an important role in the formation of hexagonal nanostructure. • Mg(OH){sub 2} nanoflakes show different crystalline structures at different positions. • The probable formation mechanism of hexagonal Mg(OH){sub 2} nanoflakes was reported. - Abstract: Hexagonal magnesium hydroxide (Mg(OH){sub 2}) nanoflakes were successfully synthesized via hydrothermal method in the presence of the surfactant polyethylene glycol 20,000 (PEG-20,000). Results show that PEG-20,000 plays an important role in the formation of this kind of nanostructure. The composition, morphologies and structure of the Mg(OH){sub 2} nanoflakes were characterized by X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), high-resolution transmission electron microscopy (HRTEM), and selected area electron diffraction (SAED). The SAED patterns taken from the different positions on a single hexagonal Mg(OH){sub 2} nanoflake show different crystalline structures. The structure of the nanoflakes are polycrystalline and the probable formation mechanism of Mg(OH){sub 2} nanoflakes is discussed. Brunauer–Emmett–Teller (BET) analysis were performed to investigate the porous structure and surface area of the as-obtained nanoflakes.

  9. Size Effect on Magnesium Alloy Castings

    NASA Astrophysics Data System (ADS)

    Li, Zhenming; Wang, Qigui; Luo, Alan A.; Zhang, Peng; Peng, Liming

    2016-06-01

    The effect of grain size on tensile and fatigue properties has been investigated in cast Mg alloys of Mg-2.98Nd-0.19Zn (1530 μm) and Mg-2.99Nd-0.2Zn-0.51Zr (41 μm). The difference between RB and push-pull fatigue testing was also evaluated in both alloys. The NZ30K05-T6 alloy shows much better tensile strengths (increased by 246 pct in YS and 159 pct in UTS) and fatigue strength (improved by ~80 pct) in comparison with NZ30-T6 alloy. RB fatigue testing results in higher fatigue strength compared with push-pull fatigue testing, mainly due to the stress/strain gradient in the RB specimen cross section. The material with coarse grains could be hardened more in the cyclic loading condition than in the monotonic loading condition, corresponding to the lower σ f and the higher σ f/ σ b or σ f/ σ 0.2 ratio compared to the materials with fine grains. The fatigue crack initiation sites and failure mechanism are mainly determined by the applied stress/strain amplitude. In LCF, fatigue failure mainly originates from the PSBs within the surface or subsurface grains of the samples. In HCF, cyclic deformation and damage irreversibly caused by environment-assisted cyclic slip is the crucial factor to influence the fatigue crack. The Coffin-Manson law and Basquin equation, and the developed MSF models and fatigue strength models can be used to predict fatigue lives and fatigue strengths of cast magnesium alloys.

  10. Dietary Fatty Acid Composition Alters Magnesium Metabolism, Distribution, and Marginal Deficiency Response in Rats

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Based on dietary intake recommendations, magnesium deficiency commonly occurs throughout the world. However, widespread pathological conditions induced by dietary magnesium deficiency have not been identified. This discrepancy may be caused by other dietary factors ameliorating or exacerbating the r...

  11. Effect of magnesium on nerve conduction velocity during regular dialysis treatment

    PubMed Central

    Fleming, Laura W.; Lenman, J. A. R.; Stewart, W. K.

    1972-01-01

    Serial nerve conduction velocities in the peroneal and ulnar nerves have been measured in 10 patients on regular dialysis treatment over a three year period. Each patient alternated between phases on dialysis with magnesium-containing dialysate (1·5-1·7 m-equiv/l.) and phases on `magnesium-free' dialysate (0·2 m-equiv/l.). Plasma magnesium concentrations were high both pre- and post-dialysis during magnesium-containing dialysis, and normal to low on magnesium-free dialysis. All patients had defects in nerve conduction, mainly asymptomatic. Increases in nerve conduction velocity coincided with magnesium-free dialysis, and decreases occurred when the patients reverted to magnesium-containing dialysate. The significance of the correlation by the sign test was P<0·0005. It is concluded that extracellular magnesium levels can influence the rate of nerve conduction in vivo. PMID:4338446

  12. Magnesium intake is inversely associated with coronary artery calcification: the Framingham Heart Study

    Technology Transfer Automated Retrieval System (TEKTRAN)

    OBJECTIVES: The aim of this study was to examine whether magnesium intake is associated with coronary artery calcification (CAC) and abdominal aortic calcification (AAC). BACKGROUND: Animal and cell studies suggest that magnesium may prevent calcification within atherosclerotic plaques underlying c...

  13. Periodic Shorting of SOM Cell to Remove Soluble Magnesium in Molten Flux and Improve Faradaic Efficiency

    NASA Astrophysics Data System (ADS)

    Guan, Xiaofei; Su, Shizhao; Pal, Uday B.; Powell, Adam C.

    2014-12-01

    Solid oxide membrane (SOM) electrolysis has been used for magnesium production directly from magnesium oxide. Magnesium dissolution in molten flux electrolyte is of particular concern in SOM electrolysis, because it imparts electronic conductivity to the flux and thereby decreases the faradaic current efficiency. In this work, a new approach for removing soluble magnesium in the flux is explored. Periodic shorting is performed between the anode and the cathode of SOM electrolysis cell. During shorting, soluble magnesium in the flux is oxidized to magnesium oxide. This significantly reduces the electronic current in the flux and therefore keeps the faradaic current efficiency high during SOM electrolysis. Electronic transference numbers in the flux are measured to assess the soluble magnesium concentration. Potentiodynamic scan results also confirm the feasibility of shorting the electrodes to remove soluble magnesium.

  14. Permeation of topically applied Magnesium ions through human skin is facilitated by hair follicles.

    PubMed

    Chandrasekaran, Navin Chandrakanth; Sanchez, Washington Y; Mohammed, Yousuf H; Grice, Jeffrey E; Roberts, Michael S; Barnard, Ross T

    2016-06-01

    Magnesium is an important micronutrient essential for various biological processes and its deficiency has been linked to several inflammatory disorders in humans. Topical magnesium delivery is one of the oldest forms of therapy for skin diseases, for example Dead Sea therapy and Epsom salt baths. Some anecdotal evidence and a few published reports have attributed amelioration of inflammatory skin conditions to the topical application of magnesium. On the other hand, transport of magnesium ions across the protective barrier of skin, the stratum corneum, is contentious. Our primary aim in this study was to estimate the extent of magnesium ion permeation through human skin and the role of hair follicles in facilitating the permeation. Upon topical application of magnesium solution, we found that magnesium penetrates through human stratum corneum and it depends on concentration and time of exposure. We also found that hair follicles make a significant contribution to magnesium penetration. PMID:27624531

  15. Hybrid system for rechargeable magnesium battery with high energy density.

    PubMed

    Chang, Zheng; Yang, Yaqiong; Wang, Xiaowei; Li, Minxia; Fu, Zhengwen; Wu, Yuping; Holze, Rudolf

    2015-01-01

    One of the main challenges of electrical energy storage (EES) is the development of environmentally friendly battery systems with high safety and high energy density. Rechargeable Mg batteries have been long considered as one highly promising system due to the use of low cost and dendrite-free magnesium metal. The bottleneck for traditional Mg batteries is to achieve high energy density since their output voltage is below 2.0 V. Here, we report a magnesium battery using Mg in Grignard reagent-based electrolyte as the negative electrode, a lithium intercalation compound in aqueous solution as the positive electrode, and a solid electrolyte as a separator. Its average discharge voltage is 2.1 V with stable discharge platform and good cycling life. The calculated energy density based on the two electrodes is high. These findings open another door to rechargeable magnesium batteries. PMID:26173624

  16. Magnesium recycling in the United States in 1998

    USGS Publications Warehouse

    Kramer, Deborah A.

    2001-01-01

    As concern for the environment has grown in recent years, the importance of recycling has become more evident. The more materials that are recycled, the fewer natural resources will be consumed and the fewer waste products will end up in landfills, in the water, and in the air. As one of a series of reports on metals recycling, this report discusses the 1998 flow of magnesium from extraction through its uses with particular emphasis on recycling. In 1998, the recycling rate for magnesium was estimated to be 33 percent?almost 60 percent of the magnesium that was recycled came from new scrap, primarily waste from diecasting operations. The principal source of old scrap was recycled aluminum beverage cans.

  17. The Superheat Phenomenon in the Combustion of Magnesium Particles

    NASA Technical Reports Server (NTRS)

    Shafirovich, E. IA.; Goldshleger, U. I.

    1992-01-01

    Magnesium is known to be a likely fuel for engines that could work in the CO2 atmospheres of Mars and Venus. The present paper reports temperature measurements of magnesium samples during combustion in CO2. The burning sample temperature increases with the decrease in the initial size. The temperature of the 1-mm samples is 300-400 K higher than the boiling point of magnesium. The stability of the superheated drop is explained by the presence of a porous shell on the surface. An attempt has been made to describe vaporization on the superheated drop by the Knudsen-Langmuir equation. During combustion at high-pressure fragment ejection of the flame is observed in high-speed motion pictures. This phenomenon is shown to be connected with the drop superheat. The repeated fracture of the outer shell formed in the flame ensures the complete burnout of metal particles at high pressure.

  18. Magnesium recycling in the United States in 1998

    USGS Publications Warehouse

    Kramer, Deborah A.

    2002-01-01

    As concern for the environment has grown in recent years, the importance of recycling has become more evident. The more materials that are recycled, the fewer natural resources will be consumed and the fewer waste products will end up in landfills, the water, and the air. As one of a series of reports on metals recycling, this report discusses the 1998 flow of magnesium in the United States from extraction through its uses with particular emphasis on recycling. In 1998, the recycling efficiency for magnesium was estimated to be 33 percent--almost 60 percent of the magnesium that was recycled came from new scrap, primarily waste from die-casting operations. The principal source of old scrap was recycled aluminum beverage cans.

  19. High Velocity Forming of Magnesium and Titanium Sheets

    SciTech Connect

    Revuelta, A.; Larkiola, J.; Korhonen, A. S.; Kanervo, K.

    2007-04-07

    Cold forming of magnesium and titanium is difficult due to their hexagonal crystal structure and limited number of available slip systems. However, high velocity deformation can be quite effective in increasing the forming limits. In this study, electromagnetic forming (EMF) of thin AZ31B-O magnesium and CP grade 1 titanium sheets were compared with normal deep drawing. Same dies were used in both forming processes. Finite element (FE) simulations were carried out to improve the EMF process parameters. Constitutive data was determined using Split Hopkinson Pressure Bar tests (SHPB). To study formability, sample sheets were electromagnetically launched to the female die, using a flat spiral electromagnetic coil and aluminum driver sheets. Deep drawing tests were made by a laboratory press-machine.Results show that high velocity forming processes increase the formability of Magnesium and Titanium sheets although process parameters have to be carefully tuned to obtain good results.

  20. Nanostructured material for advanced energy storage : magnesium battery cathode development.

    SciTech Connect

    Sigmund, Wolfgang M.; Woan, Karran V.; Bell, Nelson Simmons

    2010-11-01

    Magnesium batteries are alternatives to the use of lithium ion and nickel metal hydride secondary batteries due to magnesium's abundance, safety of operation, and lower toxicity of disposal. The divalency of the magnesium ion and its chemistry poses some difficulties for its general and industrial use. This work developed a continuous and fibrous nanoscale network of the cathode material through the use of electrospinning with the goal of enhancing performance and reactivity of the battery. The system was characterized and preliminary tests were performed on the constructed battery cells. We were successful in building and testing a series of electrochemical systems that demonstrated good cyclability maintaining 60-70% of discharge capacity after more than 50 charge-discharge cycles.

  1. WARM WATER SCALE MODEL EXPERIMENTS FOR MAGNESIUM DIE CASTING

    SciTech Connect

    Sabau, Adrian S

    2006-01-01

    High-pressure die casting (HPDC) involves the filling of a cavity with the molten metal through a thin gate. High gate velocities yield jet break-up and atomization phenomena. In order to improve the quality of magnesium parts, the mold filling pattern, including atomization phenomena, needs to be understood. The goal of this study was to obtain experimental data on jet break-up characteristics for conditions similar to that of magnesium HPDC, and measure the droplet velocity and size distribution. A scale analysis is first presented in order to identify appropriate analogue for liquid magnesium alloys. Based on the scale analysis warm water was chosen as a suitable analogue and different nozzles were manufactured. A 2-D component phase Doppler particle analyzer (PDPA) and 2-D component particle image velocimetry (PIV) were then used to obtain fine particle diameter and velocity distributions in 2-D plane.

  2. Production, structure, texture, and mechanical properties of severely deformed magnesium

    NASA Astrophysics Data System (ADS)

    Volkov, A. Yu.; Antonova, O. V.; Kamenetskii, B. I.; Klyukin, I. V.; Komkova, D. A.; Antonov, B. D.

    2016-05-01

    Methods of the severe plastic deformation (SPD) of pure magnesium at room temperature, namely, transverse extrusion and hydroextrusion in a self-destroyed shell, have been developed. The maximum true strain of the samples after the hydroextrusion was e ~ 3.2; in the course of transverse extrusion and subsequent cold rolling, a true strain of e ~ 6.0 was achieved. The structure and mechanical properties of the magnesium samples have been studied in different structural states. It has been shown that the SPD led to a decrease in the grain size d to ~2 μm; the relative elongation at fracture δ increased to ~20%. No active twinning has been revealed. The reasons for the high plasticity of magnesium after SPD according to the deformation modes suggested are discussed from the viewpoint of the hierarchy of the observed structural states.

  3. On the Modeling of Plastic Deformation of Magnesium Alloys

    SciTech Connect

    Ertuerk, S.; Steglich, D.; Bohlen, J.; Letzig, D.; Brocks, W.

    2007-05-17

    Magnesium alloys are promising materials due to their low density and therefore high specific strength. However, the industrial application is not well established so far, especially for wrought products such as sheets or profiles. Due to its hexagonal crystallographic structure, deformation mechanisms observed in magnesium alloys are rather different from those in face centered cubic metals such as aluminum alloys. This leads not only to a mechanical anisotropy, but also to a tension-compression asymmetry, i.e. unequal compressive and tensile yield strength. The resulting complexity in the yielding behavior of such materials cannot be captured by conventional models of J2 plasticity. Cazacu and Barlat, therefore, proposed a phenomenological yield potential which accounts for the respective phenomena by introducing the third invariant of the stress tensor. Simulations based on this model are performed with ABAQUS/Explicit and a user defined routine VUMAT for validating the respective implementation. The application aims at simulating the extrusion process of magnesium alloys.

  4. Friction Tests in Magnesium Tube Hydroforming at Elevated Temperatures

    SciTech Connect

    Hwang, Yeong-Maw; Wang, Kuo-Hsing; Kuo, Tsung-Yu

    2011-05-04

    In metal forming, lubricants have a variety of functions. The top priority is usually reduction of friction in order to increase the formability of the materials and reduce tool wear. Because magnesium alloys have very poor formability at room temperature, it is essential to manufacture a part from Magnesium alloys at elevated temperatures. The aim of this paper is to present a friction test method to evaluate the performance of different kinds of lubricants and determine their coefficients of friction at elevated temperatures in tube hydroforming of magnesium alloys. A self-designed experimental apparatus is used to carry out the experiments of friction tests. The coefficient of friction between the tube and die at guiding zone is determined. The effects of the internal pressure, the axial feeding velocity and temperatures on the friction forces and coefficients of friction for different lubricants are discussed.

  5. Temperature Dependent Constitutive Modeling for Magnesium Alloy Sheet

    SciTech Connect

    Lee, Jong K.; Lee, June K.; Kim, Hyung S.; Kim, Heon Y.

    2010-06-15

    Magnesium alloys have been increasingly used in automotive and electronic industries because of their excellent strength to weight ratio and EMI shielding properties. However, magnesium alloys have low formability at room temperature due to their unique mechanical behavior (twinning and untwining), prompting for forming at an elevated temperature. In this study, a temperature dependent constitutive model for magnesium alloy (AZ31B) sheet is developed. A hardening law based on non linear kinematic hardening model is used to consider Bauschinger effect properly. Material parameters are determined from a series of uni-axial cyclic experiments (T-C-T or C-T-C) with the temperature ranging 150-250 deg. C. The influence of temperature on the constitutive equation is introduced by the material parameters assumed to be functions of temperature. Fitting process of the assumed model to measured data is presented and the results are compared.

  6. Renal Control of Calcium, Phosphate, and Magnesium Homeostasis

    PubMed Central

    Chonchol, Michel; Levi, Moshe

    2015-01-01

    Calcium, phosphate, and magnesium are multivalent cations that are important for many biologic and cellular functions. The kidneys play a central role in the homeostasis of these ions. Gastrointestinal absorption is balanced by renal excretion. When body stores of these ions decline significantly, gastrointestinal absorption, bone resorption, and renal tubular reabsorption increase to normalize their levels. Renal regulation of these ions occurs through glomerular filtration and tubular reabsorption and/or secretion and is therefore an important determinant of plasma ion concentration. Under physiologic conditions, the whole body balance of calcium, phosphate, and magnesium is maintained by fine adjustments of urinary excretion to equal the net intake. This review discusses how calcium, phosphate, and magnesium are handled by the kidneys. PMID:25287933

  7. High Velocity Forming of Magnesium and Titanium Sheets

    NASA Astrophysics Data System (ADS)

    Revuelta, A.; Larkiola, J.; Korhonen, A. S.; Kanervo, K.

    2007-04-01

    Cold forming of magnesium and titanium is difficult due to their hexagonal crystal structure and limited number of available slip systems. However, high velocity deformation can be quite effective in increasing the forming limits. In this study, electromagnetic forming (EMF) of thin AZ31B-O magnesium and CP grade 1 titanium sheets were compared with normal deep drawing. Same dies were used in both forming processes. Finite element (FE) simulations were carried out to improve the EMF process parameters. Constitutive data was determined using Split Hopkinson Pressure Bar tests (SHPB). To study formability, sample sheets were electromagnetically launched to the female die, using a flat spiral electromagnetic coil and aluminum driver sheets. Deep drawing tests were made by a laboratory press-machine. Results show that high velocity forming processes increase the formability of Magnesium and Titanium sheets although process parameters have to be carefully tuned to obtain good results.

  8. Nano-Ordered Wear Property of Magnesium Obtaining Nanoindentation

    NASA Astrophysics Data System (ADS)

    Somekawa, Hidetoshi; Tomita, Kazuhiro; Toda, Miwako; Hirayama, Tomoko; Matsuoka, Takashi

    2015-09-01

    The nano-scale wear properties of single-crystalline and polycrystalline magnesium were investigated using the nanoindentation technique. The results for single crystals revealed that the crystal orientation affected the wear rate in the case that no deformation twinning was formed, e.g., under conditions of low applied loads. However, when deformation twinning formed during scratch testing, the wear properties became worse, i.e., the wear rate increased. One reason was that twin boundaries did not play a role as dislocation sources and sinks; the dislocations at twin boundaries brought about the expansion and growth for deformation twinning. As for the impact of grain boundaries on the wear properties, the wear rate for fine-grained magnesium was similar to that for single crystals. This result indicated that the existence of grain boundaries did not effectively improve the wear properties of magnesium, as in large-scale wear testing, such as the pin-on-disk configuration.

  9. Temperature Dependent Constitutive Modeling for Magnesium Alloy Sheet

    NASA Astrophysics Data System (ADS)

    Lee, Jong K.; Lee, June K.; Kim, Hyung S.; Kim, Heon Y.

    2010-06-01

    Magnesium alloys have been increasingly used in automotive and electronic industries because of their excellent strength to weight ratio and EMI shielding properties. However, magnesium alloys have low formability at room temperature due to their unique mechanical behavior (twinning and untwining), prompting for forming at an elevated temperature. In this study, a temperature dependent constitutive model for magnesium alloy (AZ31B) sheet is developed. A hardening law based on non linear kinematic hardening model is used to consider Bauschinger effect properly. Material parameters are determined from a series of uni-axial cyclic experiments (T-C-T or C-T-C) with the temperature ranging 150-250° C. The influence of temperature on the constitutive equation is introduced by the material parameters assumed to be functions of temperature. Fitting process of the assumed model to measured data is presented and the results are compared.

  10. [Magnesium: the missing link between kidneys and vessels?].

    PubMed

    Tran, Thien-An; Jaques, David; Ponte, Belen

    2016-02-24

    Chronic kidney disease is highly prevalent worldwide and is associated with important cardiovascular morbidity and mortality. The search for new prognostic factors and therapeutic targets is therefore essential. There has been recently an increased interest about magnesium, poorly studied yet in that context. In this article, we review the most recent studies looking at the associations between magnesium, cardiovascular and chronic kidney disease. According to the available data, hypomagnesemia seems to alter negatively cardiovascular and renal prognosis. Maintaining normal magnesium levels could then be protective. However, studied populations are heterogeneous, most of the data is only observational and residual confounding factors still need to be considered. All those issues limit currently any definitive therapeutic recommendations. PMID:27039606

  11. Hybrid system for rechargeable magnesium battery with high energy density

    PubMed Central

    Chang, Zheng; Yang, Yaqiong; Wang, Xiaowei; Li, Minxia; Fu, Zhengwen; Wu, Yuping; Holze, Rudolf

    2015-01-01

    One of the main challenges of electrical energy storage (EES) is the development of environmentally friendly battery systems with high safety and high energy density. Rechargeable Mg batteries have been long considered as one highly promising system due to the use of low cost and dendrite-free magnesium metal. The bottleneck for traditional Mg batteries is to achieve high energy density since their output voltage is below 2.0 V. Here, we report a magnesium battery using Mg in Grignard reagent-based electrolyte as the negative electrode, a lithium intercalation compound in aqueous solution as the positive electrode, and a solid electrolyte as a separator. Its average discharge voltage is 2.1 V with stable discharge platform and good cycling life. The calculated energy density based on the two electrodes is high. These findings open another door to rechargeable magnesium batteries. PMID:26173624

  12. Nonaqueous magnesium electrochemistry and its application in secondary batteries.

    PubMed

    Aurbach, Doron; Weissman, Idit; Gofer, Yosef; Levi, Elena

    2003-01-01

    A revolution in modern electronics has led to the miniaturization and evolution of many portable devices, such as cellular telephones and laptop computers, since the 1980s. This has led to an increasing demand for new and compatible energy storage technologies. Furthermore, a growing awareness of pollution issues has provided a strong impetus for the science and technology community to develop alternatives with ever-higher energy densities, with the ultimate goal of being able to propel electric vehicles. Magnesium's thermodynamic properties make this metal a natural candidate for utilization as an anode in high-energy-density, rechargeable battery systems. We report herein on the results of extensive studies on magnesium anodes and magnesium insertion electrodes in nonaqueous electrolyte solutions. Novel, rechargeable nonaqueous magnesium battery systems were developed based on the research. This work had two major challenges: one was to develop electrolyte solutions with especially high anodic stability in which magnesium anodes can function at a high level of cycling efficiency; the other was to develop a cathode that can reversibly intercalate Mg ions in these electrolyte systems. The new magnesium batteries consist of Mg metal anodes, an electrolyte with a general structure of Mg(AlX(3-n)R(n)R')(2) (R',R = alkyl groups, X = halide) in ethereal solutions (e.g., tetrahydrofuran, polyethers of the "glyme" family), and Chevrel phases of MgMo(3)S(4) stoichiometry as highly reversible cathodes. With their practical energy density expected to be >60 Wh/Kg, the battery systems can be cycled thousands of times with almost no capacity fading. The batteries are an environmentally friendly alternative to lead-acid and nickel-cadmium batteries and are composed of abundant, inexpensive, and nonpoisonous materials. The batteries are expected to provide superior results in large devices that require high-energy density, high cycle life, a high degree of safety, and low

  13. Magnesium sulphate for fetal neuroprotection: a cost-effectiveness analysis

    PubMed Central

    2013-01-01

    Background The aim of this study was to assess the cost-effectiveness of administering magnesium sulphate to patients in whom preterm birth at < 32+0 weeks gestation is either imminent or threatened for the purpose of fetal neuroprotection. Methods Multiple decision tree models and probabilistic sensitivity analyses were used to compare the administration of magnesium sulphate with the alternative of no treatment. Two separate cost perspectives were utilized in this series of analyses: a health system and a societal perspective. In addition, two separate measures of effectiveness were utilized: cases of cerebral palsy (CP) averted and quality-adjusted life years (QALYs). Results From a health system and a societal perspective, respectively, a savings of $2,242 and $112,602 is obtained for each QALY gained and a savings of $30,942 and $1,554,198 is obtained for each case of CP averted when magnesium sulphate is administered to patients in whom preterm birth is imminent. From a health system perspective and a societal perspective, respectively, a cost of $2,083 is incurred and a savings of $108,277 is obtained for each QALY gained and a cost of $28,755 is incurred and a savings of $1,494,500 is obtained for each case of CP averted when magnesium sulphate is administered to patients in whom preterm birth is threatened. Conclusions Administration of magnesium sulphate to patients in whom preterm birth is imminent is a dominant (i.e. cost-effective) strategy, no matter what cost perspective or measure of effectiveness is used. Administration of magnesium sulphate to patients in whom preterm birth is threatened is a dominant strategy from a societal perspective and is very likely to be cost-effective from a health system perspective. PMID:24350635

  14. The effect of dissolved magnesium on diffusion creep in calcite

    NASA Astrophysics Data System (ADS)

    Herwegh, Marco; Xiao, Xiaohui; Evans, Brian

    2003-07-01

    We experimentally tested a series of synthetic calcite marbles with varying amounts of dissolved magnesium in a standard triaxial deformation machine at 300 MPa confining pressure, temperatures between 700 and 850°C, stresses between 2 and 100 MPa, and strain rates between 10 -7 and 10 -3 s -1. The samples were fabricated by hot isostatic pressing of a mixture of calcite and dolomite at 850°C and 300 MPa. The fabrication protocol resulted in a homogeneous, fine-grained high-magnesian calcite aggregate with minimal porosity and with magnesium contents between 0.07 and 0.17 mol% MgCO 3. At stresses below 40 MPa the samples deformed with linear viscosity that depended inversely on grain size to the 3.26±0.51 power, suggesting that the mechanisms of deformation were some combination of grain boundary diffusion and grain boundary sliding. Because small grain sizes tended to occur in the high-magnesium calcite, the strength also appeared to vary inversely with magnesium content. However, the strength at constant grain size does not depend on the amount of dissolved magnesium, and thus, the impurity effect seems to be indirect. At stresses higher than 40 MPa, the aggregates become non-linearly viscous, a regime we interpret to be dislocation creep. The transition between the two regimes depends on grain size, as expected. The activation energy for diffusion creep is 200±30 kJ/mol and is quite similar to previous measurements in natural and synthetic marbles deformed at similar conditions with no added magnesium.

  15. Influence of Magnesium Alloy Degradation on Undifferentiated Human Cells

    PubMed Central

    Martinez-Sanchez, Adela Helvia; Luthringer, Berengere Julie Christine; Feyerabend, Frank; Jimbo, Ryo; Willumeit-Römer, Regine; Wennerberg, Ann

    2015-01-01

    Background Magnesium alloys are of particular interest in medical science since they provide compatible mechanical properties with those of the cortical bone and, depending on the alloying elements, they have the capability to tailor the degradation rate in physiological conditions, providing alternative bioresorbable materials for bone applications. The present study investigates the in vitro short-term response of human undifferentiated cells on three magnesium alloys and high-purity magnesium (Mg). Materials and Methods The degradation parameters of magnesium-silver (Mg2Ag), magnesium-gadolinium (Mg10Gd) and magnesium-rare-earth (Mg4Y3RE) alloys were analysed after 1, 2, and 3 days of incubation in cell culture medium under cell culture condition. Changes in cell viability and cell adhesion were evaluated by culturing human umbilical cord perivascular cells on corroded Mg materials to examine how the degradation influences the cellular development. Results and Conclusions The pH and osmolality of the medium increased with increasing degradation rate and it was found to be most pronounced for Mg4Y3RE alloy. The biological observations showed that HUCPV exhibited a more homogeneous cell growth on Mg alloys compared to high-purity Mg, where they showed a clustered morphology. Moreover, cells exhibited a slightly higher density on Mg2Ag and Mg10Gd in comparison to Mg4Y3RE, due to the lower alkalinisation and osmolality of the incubation medium. However, cells grown on Mg10Gd and Mg4Y3RE generated more developed and healthy cellular structures that allowed them to better adhere to the surface. This can be attributable to a more stable and homogeneous degradation of the outer surface with respect to the incubation time. PMID:26600388

  16. 21 CFR 522.380 - Chloral hydrate, pentobarbital, and magnesium sulfate sterile aqueous solution.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Chloral hydrate, pentobarbital, and magnesium... INJECTABLE DOSAGE FORM NEW ANIMAL DRUGS § 522.380 Chloral hydrate, pentobarbital, and magnesium sulfate sterile aqueous solution. (a) (b)(1) Specifications. Chloral hydrate, pentobarbital, and magnesium...

  17. EFFECTS OF MAGNESIUM PEMOLINE UPON HUMAN LEARNING, MEMORY, AND PERFORMANCE TESTS.

    ERIC Educational Resources Information Center

    SMITH, RONALD G.

    THIS STUDY WAS CONDUCTED DURING 1966 TO DETERMINE THE EFFECTS OF MAGNESIUM PEMOLINE (A COMBINATION OF 2-IMINO-5-PHENYL-4-OXAZOLIDINONE AND MAGNESIUM HYDROXIDE) ON A VARIETY OF HUMAN LEARNING, MEMORY, AND PERFORMANCE TASKS. MAGNESIUM PEMOLINE (25 OR 37.5 MG) OR A PLACEBO WAS ADMINISTERED ORALLY ON A DOUBLE-BLIND BASIS TO INTELLIGENCE-MATCHED GROUPS…

  18. 76 FR 26247 - Magnesium Metal From the Russian Federation: Preliminary Results of Antidumping Duty...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-06

    ..., silicon, rare earth metals/mischmetal, cryolite, silica/fly ash, magnesium oxide, periclase, ferroalloys...: Magnesium Metal From the Russian Federation, 70 FR 19930 (April 15, 2005). On April 1, 2010, the Department... Administrative Review, 75 FR 78968 (December 17, 2010), and Magnesium Metal From the Russian...

  19. 21 CFR 201.312 - Magnesium sulfate heptahydrate; label declaration on drug products.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... Drug Products § 201.312 Magnesium sulfate heptahydrate; label declaration on drug products. Magnesium sulfate heptahydrate should be listed on the label of a drug product as epsom salt, which is its common or... 21 Food and Drugs 4 2011-04-01 2011-04-01 false Magnesium sulfate heptahydrate; label...

  20. 21 CFR 201.312 - Magnesium sulfate heptahydrate; label declaration on drug products.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... Drug Products § 201.312 Magnesium sulfate heptahydrate; label declaration on drug products. Magnesium sulfate heptahydrate should be listed on the label of a drug product as epsom salt, which is its common or... 21 Food and Drugs 4 2014-04-01 2014-04-01 false Magnesium sulfate heptahydrate; label...

  1. 21 CFR 201.312 - Magnesium sulfate heptahydrate; label declaration on drug products.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... Drug Products § 201.312 Magnesium sulfate heptahydrate; label declaration on drug products. Magnesium sulfate heptahydrate should be listed on the label of a drug product as epsom salt, which is its common or... 21 Food and Drugs 4 2013-04-01 2013-04-01 false Magnesium sulfate heptahydrate; label...

  2. 21 CFR 522.380 - Chloral hydrate, pentobarbital, and magnesium sulfate sterile aqueous solution.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Chloral hydrate, pentobarbital, and magnesium... INJECTABLE DOSAGE FORM NEW ANIMAL DRUGS § 522.380 Chloral hydrate, pentobarbital, and magnesium sulfate sterile aqueous solution. (a) (b)(1) Specifications. Chloral hydrate, pentobarbital, and magnesium...

  3. 21 CFR 522.380 - Chloral hydrate, pentobarbital, and magnesium sulfate sterile aqueous solution.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Chloral hydrate, pentobarbital, and magnesium... INJECTABLE DOSAGE FORM NEW ANIMAL DRUGS § 522.380 Chloral hydrate, pentobarbital, and magnesium sulfate sterile aqueous solution. (a) (b)(1) Specifications. Chloral hydrate, pentobarbital, and magnesium...

  4. 21 CFR 522.380 - Chloral hydrate, pentobarbital, and magnesium sulfate sterile aqueous solution.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Chloral hydrate, pentobarbital, and magnesium... INJECTABLE DOSAGE FORM NEW ANIMAL DRUGS § 522.380 Chloral hydrate, pentobarbital, and magnesium sulfate sterile aqueous solution. (a) (b)(1) Specifications. Chloral hydrate, pentobarbital, and magnesium...

  5. 40 CFR 721.10573 - Magnesium hydroxide surface treated with substituted alkoxysilanes (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Magnesium hydroxide surface treated... SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.10573 Magnesium hydroxide surface... to reporting. (1) The chemical substance identified generically as magnesium hydroxide...

  6. 40 CFR 471.20 - Applicability; description of the magnesium forming subcategory.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... magnesium forming subcategory. 471.20 Section 471.20 Protection of Environment ENVIRONMENTAL PROTECTION... POWDERS POINT SOURCE CATEGORY Magnesium Forming Subcategory § 471.20 Applicability; description of the magnesium forming subcategory. This subpart applies to discharges of pollutants to waters of the...

  7. 40 CFR 721.10573 - Magnesium hydroxide surface treated with substituted alkoxysilanes (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Magnesium hydroxide surface treated... SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.10573 Magnesium hydroxide surface... to reporting. (1) The chemical substance identified generically as magnesium hydroxide...

  8. 40 CFR 471.20 - Applicability; description of the magnesium forming subcategory.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... magnesium forming subcategory. 471.20 Section 471.20 Protection of Environment ENVIRONMENTAL PROTECTION... POWDERS POINT SOURCE CATEGORY Magnesium Forming Subcategory § 471.20 Applicability; description of the magnesium forming subcategory. This subpart applies to discharges of pollutants to waters of the...

  9. 40 CFR 471.20 - Applicability; description of the magnesium forming subcategory.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... magnesium forming subcategory. 471.20 Section 471.20 Protection of Environment ENVIRONMENTAL PROTECTION... POWDERS POINT SOURCE CATEGORY Magnesium Forming Subcategory § 471.20 Applicability; description of the magnesium forming subcategory. This subpart applies to discharges of pollutants to waters of the...

  10. Cobalt-Magnesium and Iron-Magnesium Complexes with Weakened Dinitrogen Bridges

    PubMed Central

    Dugan, Thomas R.; MacLeod, K. Cory; Brennessel, William W.

    2013-01-01

    The cooperative binding of N2 by late transition metals and main-group metals is a promising strategy for N-N bond weakening and activation. We report the use of activated Rieke magnesium for reduction of iron and cobalt complexes supported by bulky β-diketiminate ligands. Binding of N2 is accompanied by assembly of a linear M-NN-Mg-NN-M (M = Co, Fe) core with N-N bonds that are weakened, as judged by infrared spectroscopy. Both the cobalt and iron complexes require THF solvent, because of Mg-THF binding. The cobalt complex can be isolated as a pure solid, but the iron complex is stable only in solution. These results demonstrate the correlation between the binding mode and N-N weakening in heterobimetallic N2 complexes. PMID:24367236

  11. Automatic photometric titrations of calcium and magnesium in carbonate rocks

    USGS Publications Warehouse

    Shapiro, L.; Brannock, W.W.

    1955-01-01

    Rapid nonsubjective methods have been developed for the determination of calcium and magnesium in carbonate rocks. From a single solution of the sample, calcium is titrated directly, and magnesium is titrated after a rapid removal of R2O3 and precipitation of calcium as the tungstate. A concentrated and a dilute solution of disodium ethylenediamine tetraacetate are used as titrants. The concentrated solution is added almost to the end point, then the weak solution is added in an automatic titrator to determine the end point precisely.

  12. Review of magnesium hydride-based materials: development and optimisation

    NASA Astrophysics Data System (ADS)

    Crivello, J.-C.; Dam, B.; Denys, R. V.; Dornheim, M.; Grant, D. M.; Huot, J.; Jensen, T. R.; de Jongh, P.; Latroche, M.; Milanese, C.; Milčius, D.; Walker, G. S.; Webb, C. J.; Zlotea, C.; Yartys, V. A.

    2016-02-01

    Magnesium hydride has been studied extensively for applications as a hydrogen storage material owing to the favourable cost and high gravimetric and volumetric hydrogen densities. However, its high enthalpy of decomposition necessitates high working temperatures for hydrogen desorption while the slow rates for some processes such as hydrogen diffusion through the bulk create challenges for large-scale implementation. The present paper reviews fundamentals of the Mg-H system and looks at the recent advances in the optimisation of magnesium hydride as a hydrogen storage material through the use of catalytic additives, incorporation of defects and an understanding of the rate-limiting processes during absorption and desorption.

  13. Durability of high performance concrete in magnesium brine

    SciTech Connect

    Tumidajski, P.J.; Chan, G.W.

    1996-04-01

    The durability of six concretes exposed to magnesium brine was monitored for 24 months. These concretes incorporated ground granulated blast furnace slag, silica fume, and fly ash. The Young`s moduli, chloride penetrations, and median pore diameters were measured. There was a cyclic nature to these properties due to the complicated interaction of hydration with magnesium, chloride and sulfate attack. Mineral admixtures, in combination with a long initial cure, provided the most durable concrete. Concrete with 65% slag had the best overall durability to the brines tested.

  14. Exchange of sodium by magnesium in aluminum hydroxycarbonate gel.

    PubMed

    Scholtz, E C; Feldkamp, J R; White, J L; Hem, S L

    1984-07-01

    Approximately 90% of the sodium present in a washed aluminum hydroxycarbonate gel was removed by exchange with magnesium. This behavior supports recent structural studies which have suggested that cations such as sodium serve as counterions in aluminum hydroxycarbonate gel. However, sodium could not be removed from dihydroxyaluminum sodium carbonate by exchange with magnesium because sodium is part of the crystal structure. It is hypothesized that aluminum hydroxycarbonate gels which resist removal of sodium are actually mixtures containing dihydroxyaluminum sodium carbonate in addition to aluminum hydroxycarbonate. PMID:6470941

  15. The human "magnesome": detecting magnesium binding sites on human proteins

    PubMed Central

    2012-01-01

    Background Magnesium research is increasing in molecular medicine due to the relevance of this ion in several important biological processes and associated molecular pathogeneses. It is still difficult to predict from the protein covalent structure whether a human chain is or not involved in magnesium binding. This is mainly due to little information on the structural characteristics of magnesium binding sites in proteins and protein complexes. Magnesium binding features, differently from those of other divalent cations such as calcium and zinc, are elusive. Here we address a question that is relevant in protein annotation: how many human proteins can bind Mg2+? Our analysis is performed taking advantage of the recently implemented Bologna Annotation Resource (BAR-PLUS), a non hierarchical clustering method that relies on the pair wise sequence comparison of about 14 millions proteins from over 300.000 species and their grouping into clusters where annotation can safely be inherited after statistical validation. Results After cluster assignment of the latest version of the human proteome, the total number of human proteins for which we can assign putative Mg binding sites is 3,751. Among these proteins, 2,688 inherit annotation directly from human templates and 1,063 inherit annotation from templates of other organisms. Protein structures are highly conserved inside a given cluster. Transfer of structural properties is possible after alignment of a given sequence with the protein structures that characterise a given cluster as obtained with a Hidden Markov Model (HMM) based procedure. Interestingly a set of 370 human sequences inherit Mg2+ binding sites from templates sharing less than 30% sequence identity with the template. Conclusion We describe and deliver the "human magnesome", a set of proteins of the human proteome that inherit putative binding of magnesium ions. With our BAR-hMG, 251 clusters including 1,341 magnesium binding protein structures

  16. Dolomite magnesium oxychloride cement properties control method during its production

    NASA Astrophysics Data System (ADS)

    Chernykh, T. N.; Nosov, A. V.; Kramar, L. Ya

    2015-01-01

    The work considers the possibility of reducing the decomposition temperature of MgCO3 in dolomite rock, provides the results of studies of the effect of various additives and enhancers on the decomposition of magnesium and calcium components of dolomite. Chlorides additives are the most promising for dolomite rocks roast intensification. They allow shifting the MgCO3 decomposition to lower temperatures, without exerting a significant influence on the decomposition of CaCO3. Introduction of additives-enhancers is found to be an effective method of controlling the properties of dolomite MOC during roasting, producing high-strength dolomite magnesium oxychloride cements with change in volume during solidification.

  17. Magnesium Intake Is Inversely Associated With Coronary Artery Calcification

    PubMed Central

    Hruby, Adela; O'Donnell, Christopher J.; Jacques, Paul F.; Meigs, James B.; Hoffmann, Udo; McKeown, Nicola M.

    2014-01-01

    OBJECTIVES The aim of this study was to examine whether magnesium intake is associated with coronary artery calcification (CAC) and abdominal aortic calcification (AAC). BACKGROUND Animal and cell studies suggest that magnesium may prevent calcification within atherosclerotic plaques underlying cardiovascular disease. Little is known about the association of magnesium intake and atherosclerotic calcification in humans. METHODS We examined cross-sectional associations of self-reported total (dietary and supplemental) magnesium intake estimated by food frequency questionnaire with CAC and AAC in participants of the Framingham Heart Study who were free of cardiovascular disease and underwent Multi-Detector Computed Tomography (MDCT) of the heart and abdomen (n = 2,695; age: 53 ± 11 years), using multivariate-adjusted Tobit regression. CAC and AAC were quantified using modified Agatston scores (AS). Models were adjusted for age, sex, body mass index, smoking status, systolic blood pressure, fasting insulin, total-to-high-density lipoprotein cholesterol ratio, use of hormone replacement therapy (women only), menopausal status (women only), treatment for hyperlipidemia, hypertension, cardiovascular disease prevention, or diabetes, as well as self-reported intake of calcium, vitamins D and K, saturated fat, fiber, alcohol, and energy. Secondary analyses included logistic regressions of CAC and AAC outcomes as cut-points (AS >0 and AS ≥90th percentile for age and sex), as well as sex-stratified analyses. RESULTS In fully adjusted models, a 50-mg/day increment in self-reported total magnesium intake was associated with 22% lower CAC (p < 0.001) and 12% lower AAC (p = 0.07). Consistent with these observations, the odds of having any CAC were 58% lower (p trend: <0.001) and any AAC were 34% lower (p trend: 0.01), in those with the highest compared to those with the lowest magnesium intake. Stronger inverse associations were observed in women than in men. CONCLUSIONS In

  18. Microplasticity phenomena in graphite/magnesium metal matrix composites

    SciTech Connect

    Epstein, J.S.; Rawal, S.; Misra, M.

    1987-01-01

    This paper discusses localized matrix plasticity in a Pitch 55 graphite/magnesium (Gr/Mg) metal matrix composite (MMC) due to damping/hysteresis effects in bending. It was found that for this material system, chosen mainly for its damping ability, plasticity or permanent deformation occurs in the matrix material of the composite from relatively small structural deformations. Hysteresis loops were determined on a local level in the diffusion bond region between adjacent graphite fiber bundles as well as on the free edge of the magnesium face sheet of the composite. Moire interferometry was combined with research on the microstructure of this particular material system to yield these subtle results.

  19. Ignition Temperature of Magnesium Powder and Pyrotechnic Composition

    NASA Astrophysics Data System (ADS)

    Zhu, Chen-Guang; Wang, Hai-Zhen; Min, Li

    2014-07-01

    Using potassium nitrate, strontium nitrate, and potassium perchlorate as the oxidizing agents, the ignition and combustion behaviors of magnesium powders with different specific surface area were studied. The ignition temperature (Te) was extrapolated using a differential thermal analyzer, and the pyrotechnic spontaneous reaction temperature (Ts) was inferred from the temperature curve by inflection point analysis. The results showed that Ts has much better reproducibility than the extrapolated Te in characterizing the ignition of the pyrotechnic formulations. Increasing the specific surface area of the magnesium powder resulted in decreased Ts of the pyrotechnics.

  20. Association between Dietary Magnesium Intake and Hyperuricemia

    PubMed Central

    Wei, Jie; Yang, Tuo; Li, Hui; Deng, Zhen-han; Yang, Ye; Zhang, Yi; Ding, Xiang; Xie, Dong-xing; Yang, Tu-bao; Lei, Guang-hua

    2015-01-01

    Objective To examine the cross-sectional associations between dietary magnesium (Mg) intake and hyperuricemia (HU). Methods 5168 subjects were included in this study. Dietary intake was assessed using a validated semi-quantitative food frequency questionnaire. Hyperuricemia (HU) was defined as uric acid ≥ 416 μmol/L for male population and ≥ 360 μmol/L for female. A multivariable logistic analysis model was applied to test the associations after adjusting a number of potential confounding factors. Results The relative odds of the overall prevalence of HU were decreased by 0.57 times in the fourth quintile of Mg intake (OR 0.57, 95% CI 0.35–0.94) and 0.55 times in the fifth quintile (OR 0.55, 95% CI 0.30–1.01) comparing with the lowest quintile, and P for trend was 0.091. The results of multivariable linear regression also suggested a significant inverse association between serum uric acid and Mg intake (β = -0.028, P = 0.022). For male, the relative odds of HU were decreased by 0.62 times in the third quintile of Mg intake (OR 0.62, 95% CI 0.40–0.97), 0.40 times in the fourth quintile (OR 0.40, 95% CI 0.23–0.72) and 0.35 times in the fifth quintile (OR 0.35, 95% CI 0.17–0.71) comparing with the lowest quintile, and P for trend was 0.006. Multivariable adjusted inverse association was also existed between serum uric acid and Mg intake in male population (β = -0.061, P = 0.002). However, no significant association was observed between dietary Mg intake and HU for female. Conclusions The findings of this cross-sectional study indicated that dietary Mg intake is inversely associated with HU, independent of some major confounding factors. In addition, this association remains valid for the male subgroup, but not for the female subgroup. Level of Evidence LevelIII, cross-sectional study. PMID:26536119

  1. Thiamine and magnesium deficiencies: keys to disease.

    PubMed

    Lonsdale, D

    2015-02-01

    Thiamine deficiency (TD) is accepted as the cause of beriberi because of its action in the metabolism of simple carbohydrates, mainly as the rate limiting cofactor for the dehydrogenases of pyruvate and alpha-ketoglutarate, both being critical to the action of the citric acid cycle. Transketolase, dependent on thiamine and magnesium, occurs twice in the oxidative pentose pathway, important in production of reducing equivalents. Thiamine is also a cofactor in the dehydrogenase complex in the degradation of the branched chain amino acids, leucine, isoleucine and valine. In spite of these well accepted facts, the overall clinical effects of TD are still poorly understood. Because of the discovery of 2-hydroxyacyl-CoA lyase (HACL1) as the first peroxisomal enzyme in mammals found to be dependent on thiamine pyrophosphate (TPP) and the ability of thiamine to bind with prion protein, these factors should improve our clinical approach to TD. HACL1 has two important roles in alpha oxidation, the degradation of phytanic acid and shortening of 2-hydroxy long-chain fatty acids so that they can be degraded further by beta oxidation. The downstream effects of a lack of efficiency in this enzyme would be expected to be critical in normal brain metabolism. Although TD has been shown experimentally to produce reversible damage to mitochondria and there are many other causes of mitochondrial dysfunction, finding TD as the potential biochemical lesion would help in differential diagnosis. Stresses imposed by infection, head injury or inoculation can initiate intermittent cerebellar ataxia in thiamine deficiency/dependency. Medication or vaccine reactions appear to be more easily initiated in the more intelligent individuals when asymptomatic marginal malnutrition exists. Erythrocyte transketolase testing has shown that thiamine deficiency is widespread. It is hypothesized that the massive consumption of empty calories, particularly those derived from carbohydrate and fat, results in

  2. Genome-Wide Association Studies of Serum Magnesium, Potassium, and Sodium Concentrations Identify Six Loci Influencing Serum Magnesium Levels

    PubMed Central

    van Rooij, Frank J. A.; Ehret, Georg B.; Boerwinkle, Eric; Felix, Janine F.; Leak, Tennille S.; Harris, Tamara B.; Yang, Qiong; Dehghan, Abbas; Aspelund, Thor; Katz, Ronit; Homuth, Georg; Kocher, Thomas; Rettig, Rainer; Ried, Janina S.; Gieger, Christian; Prucha, Hanna; Pfeufer, Arne; Meitinger, Thomas; Coresh, Josef; Hofman, Albert; Sarnak, Mark J.; Chen, Yii-Der Ida; Uitterlinden, André G.; Chakravarti, Aravinda; Psaty, Bruce M.; van Duijn, Cornelia M.; Kao, W. H. Linda; Witteman, Jacqueline C. M.; Gudnason, Vilmundur; Siscovick, David S.; Fox, Caroline S.; Köttgen, Anna

    2010-01-01

    Magnesium, potassium, and sodium, cations commonly measured in serum, are involved in many physiological processes including energy metabolism, nerve and muscle function, signal transduction, and fluid and blood pressure regulation. To evaluate the contribution of common genetic variation to normal physiologic variation in serum concentrations of these cations, we conducted genome-wide association studies of serum magnesium, potassium, and sodium concentrations using ∼2.5 million genotyped and imputed common single nucleotide polymorphisms (SNPs) in 15,366 participants of European descent from the international CHARGE Consortium. Study-specific results were combined using fixed-effects inverse-variance weighted meta-analysis. SNPs demonstrating genome-wide significant (p<5×10−8) or suggestive associations (p<4×10−7) were evaluated for replication in an additional 8,463 subjects of European descent. The association of common variants at six genomic regions (in or near MUC1, ATP2B1, DCDC5, TRPM6, SHROOM3, and MDS1) with serum magnesium levels was genome-wide significant when meta-analyzed with the replication dataset. All initially significant SNPs from the CHARGE Consortium showed nominal association with clinically defined hypomagnesemia, two showed association with kidney function, two with bone mineral density, and one of these also associated with fasting glucose levels. Common variants in CNNM2, a magnesium transporter studied only in model systems to date, as well as in CNNM3 and CNNM4, were also associated with magnesium concentrations in this study. We observed no associations with serum sodium or potassium levels exceeding p<4×10−7. Follow-up studies of newly implicated genomic loci may provide additional insights into the regulation and homeostasis of human serum magnesium levels. PMID:20700443

  3. The Effects of High Level Magnesium Dialysis/Substitution Fluid on Magnesium Homeostasis under Regional Citrate Anticoagulation in Critically Ill

    PubMed Central

    Los, Ferdinand; Brodska, Helena

    2016-01-01

    Background The requirements for magnesium (Mg) supplementation increase under regional citrate anticoagulation (RCA) because citrate acts by chelation of bivalent cations within the blood circuit. The level of magnesium in commercially available fluids for continuous renal replacement therapy (CRRT) may not be sufficient to prevent hypomagnesemia. Methods Patients (n = 45) on CRRT (2,000 ml/h, blood flow (Qb) 100 ml/min) with RCA modality (4% trisodium citrate) using calcium free fluid with 0.75 mmol/l of Mg with additional magnesium substitution were observed after switch to the calcium-free fluid with magnesium concentration of 1.50 mmol/l (n = 42) and no extra magnesium replenishment. All patients had renal indications for CRRT, were treated with the same devices, filters and the same postfilter ionized calcium endpoint (<0.4 mmol/l) of prefilter citrate dosage. Under the high level Mg fluid the Qb, dosages of citrate and CRRT were consequently escalated in 9h steps to test various settings. Results Median balance of Mg was -0.91 (-1.18 to -0.53) mmol/h with Mg 0.75 mmol/l and 0.2 (0.06–0.35) mmol/h when fluid with Mg 1.50 mmol/l was used. It was close to zero (0.02 (-0.12–0.18) mmol/h) with higher blood flow and dosage of citrate, increased again to 0.15 (-0.11–0.25) mmol/h with 3,000 ml/h of high magnesium containing fluid (p<0.001). The arterial levels of Mg were mildly increased after the change for high level magnesium containing fluid (p<0.01). Conclusions Compared to ordinary dialysis fluid the mildly hypermagnesemic fluid provided even balances and adequate levels within ordinary configurations of CRRT with RCA and without a need for extra magnesium replenishment. Trial Registration ClinicalTrials.gov Identifier: NCT01361581 PMID:27391902

  4. Effect of the conditions of activation of magnesium chloride on the substructure and composition of applied titanium-magnesium catalysts of polymerization of ethylene

    SciTech Connect

    Zakharov, V.A.; Perkovets, D.V.; Bukatov, G.D.; Sergeev, S.A.; Moroz, E.M.; Makhtarulin, S.I.

    1989-02-01

    The effect of the conditions of activation of magnesium chloride on the substructure and composition of applied titanium-magnesium catalysts of polymerization of ethylene was studied; the catalysts were prepared by different methods: (1) by adsorption of TiCl/sub 4/ on highly disperse magnesium chloride prepared from unsolvated butylmagnesium chloride; (2) by adsorption of TiCl/sub 4/ on magnesium chloride activated by grinding; (3) by combined grinding of magnesium chloride with titanium tetrachloride. It was shown that TiCl/sub 4/ reacts with defects in the structure of the magnesium chloride, whose concentration is correlated with the size of the regions of coherent scattering determined from x-ray data.

  5. Magnesium and Osteoporosis: Current State of Knowledge and Future Research Directions

    PubMed Central

    Castiglioni, Sara; Cazzaniga, Alessandra; Albisetti, Walter; Maier, Jeanette A. M.

    2013-01-01

    A tight control of magnesium homeostasis seems to be crucial for bone health. On the basis of experimental and epidemiological studies, both low and high magnesium have harmful effects on the bones. Magnesium deficiency contributes to osteoporosis directly by acting on crystal formation and on bone cells and indirectly by impacting on the secretion and the activity of parathyroid hormone and by promoting low grade inflammation. Less is known about the mechanisms responsible for the mineralization defects observed when magnesium is elevated. Overall, controlling and maintaining magnesium homeostasis represents a helpful intervention to maintain bone integrity. PMID:23912329

  6. 76 FR 62040 - Pure Magnesium From the People's Republic of China: Final Results of Expedited Third Sunset...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-06

    ... element magnesium and produced by decomposing raw materials into magnesium metal. Pure primary magnesium..., pursuant to section 751(c) of the Act. See Initiation of Five-Year ``Sunset'' Review, 76 FR 31588 (June 1... Value: Antidumping Duty Investigation of Pure Magnesium From the Russian Federation, 60 FR 25691 (May...

  7. TRIHALOMETHANE PRECURSOR REMOVAL BY THE MAGNESIUM CARBONATE PROCESS

    EPA Science Inventory

    A project was conducted to determine and improve the ability of the magnesium carbonate process to remove trihalomethane (THM) precursors in treated drinking water. The project was conducted at a drinking water treatment plant in Melbourne, FL, which had been developed and instal...

  8. Acute tocolysis for fetal distress: terbutaline versus magnesium sulphate.

    PubMed

    Magann, E F; Cleveland, R S; Dockery, J R; Chauhan, S P; Martin, J N; Morrison, J C

    1993-11-01

    Forty-six women in active labour who developed fetal distress requiring abdominal delivery were randomized to receive 0.25 mg of terbutaline (subcutaneously) or magnesium sulphate as a 4-g bolus (intravenously) to decrease uterine activity. The terbutaline-treated group in contrast to the magnesium sulphate-treated group had reduced uterine activity as measured by Montevideo units (p < 0.002). This decrease in uterine activity was noted more rapidly in all 23 patients who received terbutaline, 1.8 +/- 0.74 minutes compared to 7.5 +/- 2.1 minutes in the 16 of 23 patients (magnesium sulphate-treated women) in whom a decrease in uterine activity occurred (p < 0.001). Umbilical cord arterial blood pH at delivery was less than 7.20 in only 2 of the 23 patients treated with terbutaline versus 7 of the 23 in the magnesium sulphate-treated group. We conclude that terbutaline is an effective and more rapid-acting tocolytic agent to arrest uterine activity prior to delivery for fetal distress. PMID:8179541

  9. 76 FR 11813 - Magnesium From China and Russia

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-03

    ... (75 FR 9252) and determined on June 4, 2010 that it would conduct full reviews (75 FR 35086, June 21... 10, 2010 (75 FR 48360). The hearing was held in Washington, DC, on December 7, 2010, and all persons... COMMISSION Magnesium From China and Russia Determinations On the basis of the record \\1\\ developed in...

  10. REGENERATION OF FISSION-PRODUCT-CONTAINING MAGNESIUM-THORIUM ALLOYS

    DOEpatents

    Chiotti, P.

    1964-02-01

    A process of regenerating a magnesium-thorium alloy contaminated with fission products, protactinium, and uranium is presented. A molten mixture of KCl--LiCl-MgCl/sub 2/ is added to the molten alloy whereby the alkali, alkaline parth, and rare earth fission products (including yttrium) and some of the thorium and uranium are chlorinated and

  11. 77 FR 59979 - Pure Magnesium (Granular) From China

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-01

    ... this five-year review. Background The Commission instituted this review on February 1, 2012 (77 FR 5049) and determined on May 7, 2012 that it would conduct an expedited review (77 FR 32668, June 1, 2012... COMMISSION Pure Magnesium (Granular) From China Determination On the basis of the record \\1\\ developed in...

  12. Crystallization of Esomeprazole Magnesium Water/Butanol Solvate.

    PubMed

    Skieneh, Jenna; Khalili Najafabadi, Bahareh; Horne, Stephen; Rohani, Sohrab

    2016-01-01

    The molecular structure of esomeprazole magnesium derivative in the solid-state is reported for the first time, along with a simplified crystallization pathway. The structure was determined using the single crystal X-ray diffraction technique to reveal the bonding relationships between esomeprazole heteroatoms and magnesium. The esomeprazole crystallization process was carried out in 1-butanol and water was utilized as anti-solvent. The product proved to be esomeprazole magnesium tetrahydrate with two 1-butanol molecules that crystallized in P6₃ space group, in a hexagonal unit cell. Complete characterization of a sample after drying was conducted by the use of powder X-ray diffraction (PXRD), ¹H-nuclear magnetic resonance (NMR), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), infrared spectroscopy (IR), and dynamic vapor sorption (DVS). Investigation by ¹H-NMR and TGA has shown that the solvent content in the dried sample consists of two water molecules and 0.3 butanol molecules per esomeprazole magnesium molecule. This is different from the single crystal X-ray diffraction results and can be attributed to the loss of some water and 1-butanol molecules stabilized by intermolecular interactions. The title compound, after drying, is a true solvate in terms of water; conversely, 1-butanol fills the voids of the crystal lattice in non-stoichiometric amounts. PMID:27120591

  13. Improved transmittance measurement with a magnesium oxide coated integrating sphere

    NASA Technical Reports Server (NTRS)

    Bowman, R. L.; Spisz, E. W.

    1972-01-01

    Simple and convenient technique has been found for extending transmittance measurement capability of conventional magnesium oxide coated integrating sphere system at low (near ultraviolet) wavelengths. Technique can be used to determine effect of contaminants on window materials and can also be used for measurements on thermal control coatings and telescope mirrors.

  14. A Life Cycle Assessment of a Magnesium Automotive Front End

    SciTech Connect

    Das, Sujit; Dubreuil, Alain; Bushi, Lindita; Tharumarajah, Ambalavanar

    2009-01-01

    The Magnesium Front End Research and Development (MFERD) project under the sponsorship of Canada, China and USA aims to develop key technologies and a knowledge base for increased use of magnesium in automobile. The goal of this life cycle assessment (LCA) study is to compare the energy and potential environmental impacts of advanced magnesium based front end parts of a North America built 2007 GM-Cadillac CTS with the standard carbon steel based design. This LCA uses the 'cradle-to-grave' approach by including primary material production, semi-fabrication production, autoparts manufacturing and assembly, transportation, use phase and end-of-life processing of autoparts. This LCA study was done in compliance with international standards ISO 14040:2006 and ISO 14044:2006. Furthermore, the LCA results for aluminum based front end autopart are presented. While weight savings result in reductions in energy use and carbon dioxide emissions during the use of the car, the impacts of fabrication and recycling of lightweight materials are substantial in regard to steel. Pathways for improving sustainability of magnesium use in automobiles through material management and technology improvements including recycling are also discussed.

  15. Preformulation Studies for Generic Omeprazole Magnesium Enteric Coated Tablets

    PubMed Central

    Migoha, C. O.; Kaale, E.; Kagashe, G.

    2015-01-01

    Preformulation is an important step in the rational formulation of an active pharmaceutical ingredient (API). Micromeritics properties: bulk density (BD) and tapped density (TD), compressibility index (Carr's index), Hauser's ratio (H), and sieve analysis were performed in order to determine the best excipients to be used in the formulation development of omeprazole magnesium enteric coated tablets. Results show that omeprazole magnesium has fair flow and compressibility properties (BD 0.4 g/mL, TD 0.485 g/mL, Carr's index 17.5%, Hauser's ratio 1.2, and sieve analysis time 5 minutes). There were no significant drug excipient interactions except change in colour in all three conditions in the mixture of omeprazole and aerosil 200. Moisture content loss on drying in all three conditions was not constant and the changes were attributed to surrounding environment during the test time. Changes in the absorption spectra were noted in the mixture of omeprazole and water aerosil only in the visible region of 350–2500 nm. Omeprazole magnesium alone and with all excipients showed no significant changes in omeprazole concentration for a 30-day period. Omeprazole magnesium formulation complies with USP standards with regards to the fineness, flowability, and compressibility of which other excipients can be used in the formulation. PMID:25699270

  16. Mechanical properties of several magnesium and aluminum composites. Final report

    SciTech Connect

    Tsangarakis, N.; Taleghani, B.

    1992-12-01

    Several composites of magnesium and aluminum alloys were tested in order to assess and evaluate their mechanical properties. The magnesium alloys were AZ91 C, ZE41 A, and commercially pure magnesium, reinforced with 40% by volume continuous graphite fiber. The tensile properties of these composites were not superior to those of unreinforced magnesium and estimates of their fracture toughness were low. The matrices of the aluminum composites were 2124-T6, 6061-T4, 2124-T4, and 2219-T4. The reinforcements were either particulate or whiskers of silicon carbide or boron carbide and their volume content was 15% to 30%. The aluminum composites which were reinforced with silicon carbide particulate exhibited improved yield and ultimate tensile stresses, as well as tensile elastic modulus over the unreinforced aluminum alloys. The 2124-T4/B4C/25p composite exhibited the highest ultimate tensile strength which was 511 MPa. The composite which was reinforced with whiskers of silicon carbide exhibited an endurance limit which was 20% higher than that of the matrix alloy. The compressive properties and fracture toughness of some of these aluminum composites were not improved over those of the unreinforced matrix alloy.... Composites, Mechanical properties.

  17. The magnesium chelation step in chlorophyll biosynthesis. Progress report 1993

    SciTech Connect

    Weinstein, J.D.

    1993-12-31

    Progress is reported on the identification and fractionation of Magnesium chealatase, an enzyme involved in addition of Mg to chlorophyll during the later`s biosynthesis. Progress is documented as a series of synopsis of published and unpublished papers by the author.

  18. Coating protects magnesium-lithium alloys against corrosion

    NASA Technical Reports Server (NTRS)

    1967-01-01

    Coating protects newly developed magnesium-lithium alloys against corrosion. The procedure includes heating the ingots in a salt bath and rolling them to the desired sheet thickness. The black coating, which is tough though thin and ductile, is derived mainly from chromium.

  19. Acoustic emission during unloading of elastically stressed magnesium alloy

    NASA Technical Reports Server (NTRS)

    Lee, S. S.; Williams, J. H., Jr.

    1977-01-01

    A magnesium alloy was quasi-statically cycled elastically between zero load and tension. Both loading and unloading stress delays were found, and the unloading stress delay was further studied. An analytical expression was written for the unloading stress delay which is an elastic constitutive parameter. The potential use of these results for the acoustic emission monitoring of elastic stress states is discussed.

  20. Adherent protective coatings plated on magnesium-lithium alloy

    NASA Technical Reports Server (NTRS)

    1965-01-01

    Zinc is plated on a magnesium-lithium alloy by using a modification of the standard zinc-plate immersion bath. Further protection is given the alloy by applying a light plating of copper on the zinc plating. Other metals are plated on the copper by using conventional plating baths.

  1. Disorders of calcium, phosphorus, and magnesium metabolism in the neonate

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Approximately 98% of the calcium, 80% of the phosphorus, and 65% of the magnesium in the body are in the skeleton. These elements, often referred to as the "bone minerals" are also constituents of the intracellular and extracellular spaces. The metabolism of these bone minerals and mineralization of...

  2. Magnesium Isotopic Composition of CAIs and Chondrules from CBb Chondrites

    NASA Astrophysics Data System (ADS)

    Gounelle, M.; Young, E. D.; Shahar, A.; Kearsley, A.

    2006-03-01

    We measured magnesium isotope ratios in 17 chondrules and 3 CAIs from the CBb chondrites HH 237 and QUE 94411 by LA-MC-ICPMS. We find no detectable 26Al excesses in the three CAIs and approximately normal (chondritic) d25Mg in CAIs and chondrules.

  3. Effects of benzotriazole on the magnesium phosphate coating

    NASA Astrophysics Data System (ADS)

    Zuo, Juan; Guo, Fen; Zhu, Junqiu; Chen, Ajiao; Hu, Yanling; Lin, Changjian; Jiang, Chunhai

    2015-12-01

    Magnesium phosphate coatings are extensively used on carbon steel to improve their corrosion resistance. The effect of benzotriazole on the magnesium phosphate coating was investigated. The phosphate coatings were deposited on carbon steel at different bath temperature, room temperature (RM), 60 °C and 80 °C. The change of crystalline phase, morphology, the sludge weight, bath efficiency factor, and corrosion behavior of the coatings after the addition of benzotriazole (BTAH) were investigated by means of Scanning Electron Microscopy (SEM), X-ray diffraction (XRD), and potentiodynamic polarization methods. The adsorption of BTAH during the formation of magnesium phosphate coating was also investigated by means of XPS. The effect of BTAH on the formation of magnesium phosphate coating was discussed. The adsorbed BTAH layer could favor the nucleation of phosphate coating by supplying more nuclei centers which leads to the formation of more compact phosphate coating. Meanwhile, the adsorbed atoms can block the active sites and generate a barrier to reduce the transport of corrosive species to the metal surface and hence improve the corrosion behavior of carbon steels.

  4. Cellular Magnesium Matrix Foam Composites for Mechanical Damping Applications

    NASA Astrophysics Data System (ADS)

    Shunmugasamy, Vasanth Chakravarthy; Mansoor, Bilal; Gupta, Nikhil

    2016-01-01

    The damping characteristics of metal alloys and metal matrix composites are relevant to the automotive, aerospace, and marine structures. Use of lightweight materials can help in increasing payload capacity and in decreasing fuel consumption. Lightweight composite materials possessing high damping capabilities that can be designed as structural members can greatly benefit in addressing these needs. In this context, the damping properties of lightweight metals such as aluminum and magnesium and their respective composites have been studied in the existing literature. This review focuses on analyzing the damping properties of aluminum and magnesium alloys and their cellular composites. The damping properties of various lightweight alloys and composites are compared on the basis of their density to understand the potential for weight saving in structural applications. Magnesium alloys are observed to possess better damping properties in comparison to aluminum. However, aluminum matrix syntactic foams reinforced with silicon carbide hollow particles possess a damping capacity and density comparable to magnesium alloy. By using the data presented in the study, composites with specific compositions and properties can be selected for a given application. In addition, the comparison of the results helps in identifying the areas where attention needs to be focused to address the future needs.

  5. RECOVERY OF LIME AND MAGNESIUM IN POTABLE WATER TREATMENT

    EPA Science Inventory

    A hard, turbid surface water was successfully treated using the magnesium carbonate process in a 2 mgd pilot plant at the treatment works of Water District No. 1 of Johnson County, Kansas, for one year during 1975 and 1976. During this study, froth flotation was used to separate ...

  6. Health Significance of Calcium and Magnesium: Examples from Human Studies

    Technology Transfer Automated Retrieval System (TEKTRAN)

    It is clear that many people do not consume recommended intakes of calcium (Ca) and magnesium (Mg), yet biochemical and/or functional changes indicative of deficiencies in these nutrients have been rare. This prompted two series of studies: one addressing an apparent Ca-deficiency rickets in child...

  7. Prehospital Use of Magnesium Sulfate as Neuroprotection in Acute Stroke

    PubMed Central

    Saver, Jeffrey L.; Starkman, Sidney; Eckstein, Marc; Stratton, Samuel J.; Pratt, Franklin D.; Hamilton, Scott; Conwit, Robin; Liebeskind, David S.; Sung, Gene; Kramer, Ian; Moreau, Gary; Goldweber, Robert; Sanossian, Nerses

    2016-01-01

    BACKGROUND Magnesium sulfate is neuroprotective in preclinical models of stroke and has shown signals of potential efficacy with an acceptable safety profile when delivered early after stroke onset in humans. Delayed initiation of neuroprotective agents has hindered earlier phase 3 trials of neuroprotective agents. METHODS We randomly assigned patients with suspected stroke to receive either intravenous magnesium sulfate or placebo, beginning within 2 hours after symptom onset. A loading dose was initiated by paramedics before the patient arrived at the hospital, and a 24-hour maintenance infusion was started on the patient’s arrival at the hospital. The primary outcome was the degree of disability at 90 days, as measured by scores on the modified Rankin scale (range, 0 to 6, with higher scores indicating greater disability). RESULTS Among the 1700 enrolled patients (857 in the magnesium group and 843 in the placebo group), the mean (±SD) age was 69±13 years, 42.6% were women, and the mean pretreatment score on the Los Angeles Motor Scale of stroke severity (range, 0 to 10, with higher scores indicating greater motor deficits) was 3.7±1.3. The final diagnosis of the qualifying event was cerebral ischemia in 73.3% of patients, intracranial hemorrhage in 22.8%, and a stroke-mimicking condition in 3.9%. The median interval between the time the patient was last known to be free of stroke symptoms and the start of the study-drug infusion was 45 minutes (interquartile range, 35 to 62), and 74.3% of patients received the study-drug infusion within the first hour after symptom onset. There was no significant shift in the distribution of 90-day disability outcomes on the global modified Rankin scale between patients in the magnesium group and those in the placebo group (P = 0.28 by the Cochran–Mantel–Haenszel test); mean scores at 90 days did not differ between the magnesium group and the placebo group (2.7 in each group, P = 1.00). No significant between

  8. Influence of corrosive solutions on microhardness and chemistry of magnesium oxide /001/ surfaces

    NASA Technical Reports Server (NTRS)

    Ishigaki, H.; Miyoshi, K.; Buckley, D. H.

    1982-01-01

    X-ray photoelectron spectroscopy analyses and hardness experiments were conducted on cleaved magnesium oxide /001/ surfaces. The magnesium oxide bulk crystals were cleaved to specimen size along the /001/ surface, and indentations were made on the cleaved surface in corrosive solutions containing HCl, NaOH, or HNO3 and in water without exposing the specimen to any other environment. The results indicated that chloride (such as MgCl2) and sodium films are formed on the magnesium oxide surface as a result of interactions between an HCl-containing solution and a cleaved magnesium oxide surface. The chloride films soften the magnesium oxide surface. In this case microhardness is strongly influenced by the pH value of the solution. The lower the pH, the lower the microhardness. Sodium films, which are formed on the magnesium oxide surface exposed to an NaOH containing solution, do not soften the magnesium oxide surface.

  9. Deformation behavior and microstructure evolution of wrought magnesium alloys

    NASA Astrophysics Data System (ADS)

    Wang, Shouren; Song, Linghui; Kang, Sukbong; Cho, Jaehyung; Wang, Yingzi

    2013-05-01

    There are many researches on the deformation behavior of wrought magnesium alloys, such as AZ31, AZ80, AZ91, and ZK60 magnesium alloys at different temperatures and strain rates, but few of them focuses on the deformation behavior of AZ41M and ZK60M alloys, especially under the twin-roll casting (TRC) state. Meanwhile, the existing researches only focus on the grain refinement law of the magnesium alloys under deformation conditions, the deformation mechanism has not been revealed yet. The hot compression behavior of AZ41M and ZK60M magnesium alloys under the temperature and strain rate ranges of 250-400 °C and 0.001-1 s-1 are studied by thermal simulation methods using Gleeble 1500 machine and virtual simulation using finite element analysis software. Simulation results show that sine hyperbolic law is the most suitable flow stress model for wider deformation conditions. The most reasonable selected deformation conditions of ZK60M alloy is 350 °C/0.1 s-1 for TRC and 350 °C/1 s-1 for conventional casting (CC), while AZ41M alloy is 300 °C/0.01 s-1 for TRC and 350 °C/0.1 s-1 for CC. Deformation behavior and dynamic recrystallization (DRX) mechanism of them are analyzed at the same deformation conditions. The microstructures of AZ41M and ZK60M alloys are observed at different deformed conditions by optical microscopy (OM) and electron back scatter diffraction (EBSD) and it reveals the flow behavior and deformation mechanism of them. Working harden and work soften contribute to the activation of basal, non-basal slip systems which promote DRX. The proposed research reveals the deformation behavior and mechanism of the AZ41M and ZK 60M magnesium alloys and concludes their optimized deformation parameters and processes and provides a theory basis for their manufacturing and application.

  10. Corrosion resistance of titanium ion implanted AZ91 magnesium alloy

    SciTech Connect

    Liu Chenglong; Xin Yunchang; Tian Xiubo; Zhao, J.; Chu, Paul K.

    2007-03-15

    Degradable metal alloys constitute a new class of materials for load-bearing biomedical implants. Owing to their good mechanical properties and biocompatibility, magnesium alloys are promising in degradable prosthetic implants. The objective of this study is to improve the corrosion behavior of surgical AZ91 magnesium alloy by titanium ion implantation. The surface characteristics of the ion implanted layer in the magnesium alloys are examined. The authors' results disclose that an intermixed layer is produced and the surface oxidized films are mainly composed of titanium oxide with a lesser amount of magnesium oxide. X-ray photoelectron spectroscopy reveals that the oxide has three layers. The outer layer which is 10 nm thick is mainly composed of MgO and TiO{sub 2} with some Mg(OH){sub 2}. The middle layer that is 50 nm thick comprises predominantly TiO{sub 2} and MgO with minor contributions from MgAl{sub 2}O{sub 4} and TiO. The third layer from the surface is rich in metallic Mg, Ti, Al, and Ti{sub 3}Al. The effects of Ti ion implantation on the corrosion resistance and electrochemical behavior of the magnesium alloys are investigated in simulated body fluids at 37{+-}1 deg. C using electrochemical impedance spectroscopy and open circuit potential techniques. Compared to the unimplanted AZ91 alloy, titanium ion implantation significantly shifts the open circuit potential (OCP) to a more positive potential and improves the corrosion resistance at OCP. This phenomenon can be ascribed to the more compact surface oxide film, enhanced reoxidation on the implanted surface, as well as the increased {beta}-Mg{sub 12}Al{sub 17} phase.

  11. Effect of magnesium infusion on thoracic epidural analgesia

    PubMed Central

    Gupta, Sampa Dutta; Mitra, Koel; Mukherjee, Maitreyee; Roy, Suddhadeb; Sarkar, Aniruddha; Kundu, Sudeshna; Goswami, Anupam; Sarkar, Uday Narayan; Sanki, Prakash; Mitra, Ritabrata

    2011-01-01

    Introduction: Patients of lung volume reduction surgery (LVRS) having an ASA status III or more are likely to be further downgraded by surgery to critical levels of pulmonary function. Aim: To compare the efficacy of thoracic epidural block with (0.125%) bupivacaine, fentanyl combination and (0.125%) bupivacaine, fentanyl combination with adjunctive intravenous magnesium infusion for the relief of postoperative pain in patients undergoing LVRS. Methods: Patients were operated under general anesthesia. Thirty minutes before the anticipated completion of skin closure in both groups, (Group A and Group B) 7 ml of (0.125%) bupivacaine calculated as 1.5 ml/thoracic segment space for achieving analgesia in dermatomes of T4, T5, T6, T7, and T8 segments, along with fentanyl 50 μg (0.5 ml), was administered through the catheter, activating the epidural block, and the time was noted. Thereafter, in patients of Group A, magnesium sulfate injection 30 mg/kg i.v. bolus was followed by infusion of magnesium sulfate at 10 mg/kg/hr and continued up to 24 hours. Group B was treated as control. Results and Analysis: A significant increase in the mean and maximum duration of analgesia in Group A in comparison with Group B (P<0.05) was observed. Total epidural dose of fentanyl and bupivacaine required in Group A was significantly lower in comparison with Group B in 24 hours. Discussion: Requirement of total doses of local anesthetics along with opioids could be minimized by magnesium infusion; therefore, the further downgradation of patients of LVRS may be prevented. Conclusion: Intravenous magnesium can prolong opioid-induced analgesia while minimizing nausea, pruritus, and somnolence. PMID:21655018

  12. Critical Issues in the Study of Magnesium Transport Systems and Magnesium Deficiency Symptoms in Plants

    PubMed Central

    Kobayashi, Natsuko I.; Tanoi, Keitaro

    2015-01-01

    Magnesium (Mg) is the second most abundant cation in living cells. Over 300 enzymes are known to be Mg-dependent, and changes in the Mg concentration significantly affects the membrane potential. As Mg becomes deficient, starch accumulation and chlorosis, bridged by the generation of reactive oxygen species, are commonly found in Mg-deficient young mature leaves. These defects further cause the inhibition of photosynthesis and finally decrease the biomass. Recently, transcriptome analysis has indicated the transcriptinal downregulation of chlorophyll apparatus at the earlier stages of Mg deficiency, and also the potential involvement of complicated networks relating to hormonal signaling and circadian oscillation. However, the processes of the common symptoms as well as the networks between Mg deficiency and signaling are not yet fully understood. Here, for the purpose of defining the missing pieces, several problems are considered and explained by providing an introduction to recent reports on physiological and transcriptional responses to Mg deficiency. In addition, it has long been unclear whether the Mg deficiency response involves the modulation of Mg2+ transport system. In this review, the current status of research on Mg2+ transport and the relating transporters are also summarized. Especially, the rapid progress in physiological characterization of the plant MRS2 gene family as well as the fundamental investigation about the molecular mechanism of the action of bacterial CorA proteins are described. PMID:26404266

  13. Magnesium in primary care and preventive medicine: clinical correlation of magnesium loading studies.

    PubMed

    Baker, S M

    Diagnostic categories that are useful for describing patients with acute or organ failure disease are generally less useful labels for primary care and preventive medicine patients whose conditions are better described by signs and symptoms. Symptoms may be clues to ill health but are not often criteria for a major diagnostic labeling. In my practice I have used a computer-based medical record system that permits portrayal and comparison of symptom data to correlate varying degrees of retention of an intramuscular magnesium-loading study (IMMLS) with symptom patterns in 172 patients. The group of patients who show a paradoxical excretion of more Mg than they were given in the IMMLS are a distinctive group with lower blood pressures and significantly fewer digestive and skin symptoms, fewer symptoms of inflammation but more emotional symptoms than those with normal Mg excretion. The group who retained > 49% of the load had higher blood pressures and significantly fewer symptoms of inflammation of the skin and of the reproductive tract. PMID:1844557

  14. Electrolytic conditioning of a magnesium aluminum chloride complex for reversible magnesium deposition

    DOE PAGESBeta

    Barile, Christopher J.; Barile, Elizabeth C.; Zavadil, Kevin R.; Nuzzo, Ralph G.; Gewirth, Andrew A.

    2014-12-04

    We describe in this report the electrochemistry of Mg deposition and dissolution from the magnesium aluminum chloride complex (MACC). The results define the requirements for reversible Mg deposition and definitively establish that voltammetric cycling of the electrolyte significantly alters its composition and performance. Elemental analysis, scanning electron microscopy, and energy-dispersive X-ray spectroscopy (SEM-EDS) results demonstrate that irreversible Mg and Al deposits form during early cycles. Electrospray ionization-mass spectrometry (ESI-MS) data show that inhibitory oligomers develop in THF-based solutions. These oligomers form via the well-established mechanism of a cationic ring-opening polymerization of THF during the initial synthesis of the MACC andmore » under resting conditions. In contrast, MACC solutions in 1,2-dimethoxyethane (DME), an acyclic solvent, do not evolve as dramatically at open circuit potential. Furthermore, we propose a mechanism describing how the conditioning process of the MACC in THF improves its performance by both tuning the Mg:Al stoichiometry and eliminating oligomers.« less

  15. Endothelial responses of magnesium and other alloying elements in magnesium-based stent materials

    PubMed Central

    Zhao, Nan; Zhu, Donghui

    2016-01-01

    Biodegradable tailored magnesium (Mg) alloys are some of the most promising scaffolds for cardiovascular stents. During the course of degradation after implantation, all the alloying elements in the scaffold will be released to the surrounding vascular tissues. However, fundamental questions regarding the toxicity of alloying elements towards vascular cells, the maximum amount of each element that could be used in alloy design, or how each of the alloying elements affects vascular cellular activity and gene expression, are still not fully answered. This work systematically addressed these questions by revealing how application of different alloying elements commonly used in Mg stent materials influences several indices of human endothelial cell health, i.e., viability, proliferations, cytoskeletal reorganizations, migration, and the gene expression profile. The overall cell viability and proliferation showed a decreasing trend with increasing concentrations of the ions, and the half maximal effective concentrations (EC50) for each element were determined. When applied at a low concentration of around 10 mM, Mg had no adverse effects but improved cell proliferation and migration instead. Mg ions also altered endothelial gene expression significantly in a dose dependent manner. Most of the changed genes are related to angiogenesis and the cell adhesion signaling pathways. Findings from this work provide useful information on maximum safe doses of these ions for endothelial cells, endothelial responses towards these metal ions, and some guidance for future Mg stent design. PMID:25363018

  16. Electrolytic conditioning of a magnesium aluminum chloride complex for reversible magnesium deposition

    SciTech Connect

    Barile, Christopher J.; Barile, Elizabeth C.; Zavadil, Kevin R.; Nuzzo, Ralph G.; Gewirth, Andrew A.

    2014-12-04

    We describe in this report the electrochemistry of Mg deposition and dissolution from the magnesium aluminum chloride complex (MACC). The results define the requirements for reversible Mg deposition and definitively establish that voltammetric cycling of the electrolyte significantly alters its composition and performance. Elemental analysis, scanning electron microscopy, and energy-dispersive X-ray spectroscopy (SEM-EDS) results demonstrate that irreversible Mg and Al deposits form during early cycles. Electrospray ionization-mass spectrometry (ESI-MS) data show that inhibitory oligomers develop in THF-based solutions. These oligomers form via the well-established mechanism of a cationic ring-opening polymerization of THF during the initial synthesis of the MACC and under resting conditions. In contrast, MACC solutions in 1,2-dimethoxyethane (DME), an acyclic solvent, do not evolve as dramatically at open circuit potential. Furthermore, we propose a mechanism describing how the conditioning process of the MACC in THF improves its performance by both tuning the Mg:Al stoichiometry and eliminating oligomers.

  17. Critical Issues in the Study of Magnesium Transport Systems and Magnesium Deficiency Symptoms in Plants.

    PubMed

    Kobayashi, Natsuko I; Tanoi, Keitaro

    2015-01-01

    Magnesium (Mg) is the second most abundant cation in living cells. Over 300 enzymes are known to be Mg-dependent, and changes in the Mg concentration significantly affects the membrane potential. As Mg becomes deficient, starch accumulation and chlorosis, bridged by the generation of reactive oxygen species, are commonly found in Mg-deficient young mature leaves. These defects further cause the inhibition of photosynthesis and finally decrease the biomass. Recently, transcriptome analysis has indicated the transcriptinal downregulation of chlorophyll apparatus at the earlier stages of Mg deficiency, and also the potential involvement of complicated networks relating to hormonal signaling and circadian oscillation. However, the processes of the common symptoms as well as the networks between Mg deficiency and signaling are not yet fully understood. Here, for the purpose of defining the missing pieces, several problems are considered and explained by providing an introduction to recent reports on physiological and transcriptional responses to Mg deficiency. In addition, it has long been unclear whether the Mg deficiency response involves the modulation of Mg2+ transport system. In this review, the current status of research on Mg2+ transport and the relating transporters are also summarized. Especially, the rapid progress in physiological characterization of the plant MRS2 gene family as well as the fundamental investigation about the molecular mechanism of the action of bacterial CorA proteins are described. PMID:26404266

  18. Novel process for recycling magnesium alloy employing refining and solid oxide membrane electrolysis

    NASA Astrophysics Data System (ADS)

    Guan, Xiaofei

    Magnesium is the least dense engineering metal, with an excellent stiffness-to-weight ratio. Magnesium recycling is important for both economic and environmental reasons. This project demonstrates feasibility of a new environmentally friendly process for recycling partially oxidized magnesium scrap to produce very pure magnesium at low cost. It combines refining and solid oxide membrane (SOM) based oxide electrolysis in the same reactor. Magnesium and its oxide are dissolved in a molten flux. This is followed by argon-assisted evaporation of dissolved magnesium, which is subsequently condensed in a separate condenser. The molten flux acts as a selective medium for magnesium dissolution, but not aluminum or iron, and therefore the magnesium collected has high purity. Potentiodynamic scans are performed to monitor the magnesium content change in the scrap as well as in solution in the flux. The SOM electrolysis is employed in the refining system to enable electrolysis of the magnesium oxide dissolved in the flux from the partially oxidized scrap. During the SOM electrolysis, oxygen anions are transported out of the flux through a yttria stabilized zirconia membrane to a liquid silver anode where they are oxidized. Simultaneously, magnesium cations are transported through the flux to a steel cathode where they are reduced. The combination of refining and SOM electrolysis yields close to 100% removal of magnesium metal from partially oxidized magnesium scrap. The magnesium recovered has a purity of 99.6w%. To produce pure oxygen it is critical to develop an inert anode current collector for use with the non-consumable liquid silver anode. In this work, an innovative inert anode current collector is successfully developed and used in SOM electrolysis experiments. The current collector employs a sintered strontium-doped lanthanum manganite (La0.8Sr0.2MnO 3-delta or LSM) bar, an Inconel alloy 601 rod, and a liquid silver contact in between. SOM electrolysis experiments

  19. Magnesium diboride superconducting devices and circuits

    NASA Astrophysics Data System (ADS)

    Galan, Elias

    While magnesium diboride (MgB2) was first synthesized in the 1950s, MgB2's superconductive properties were not discovered until 2001. It has the highest superconducting transition temperature of all the metallic superconductors at ~39 K at atmospheric pressure. MgB2 is also unique in that it has a two superconductive gaps, a pi gap at 2 meV and a sigma gap at 7.1 meV. There are a theoretical models discussing the inter- and intra- gap scattering of the superconductivity of MgB2 and the Josephson transport of MgB2 Josephson Junctions. The focus of this work is to further the study of all-MgB2 Josephson junctions and quantum interference device technology. This work discusses the transport in all-MgB2 Josephson junctions and designing, fabricating, and measuring multi-junction devices. The junctions studied include all-MgB2 sandwich-type Josephson junctions (one with TiB2 normal conducting barrier and another with an MgO insulating barrier). The junction MgB2 films were deposited by hyprid physical-vapor deposition and the junction barrier were deposited by sputtering. The junctions were patterned and etched with UV photolithography and argon ion milling. With the TiB2 barrier we studied Josephson transport by the proximity effect. With these junctions, we also observed complete suppression of the critical current by an applied magnetic field showing for the first time a leakage free barrier in an all-MgB2 Josephson junction with a single ultrathin barrier. We also studied junctions utilizing MgO barrier deposited by reactive sputtering which gave a larger characteristic voltage of 1-3 mV compared to TiB2 barriers. By connecting several SQUIDs with varying loop areas we developed of two types of superconducting quantum interference filters (SQIFs). The first SQIF designed with 21 SQUIDs connected in parallel and the SQUID loops are sensitive to magnetic fields applied parallel to the substrate. The SQUID loop areas were designed to vary in such a way that the voltage

  20. Semi-solid Twin-roll Casting Process of Magnesium Alloy Sheets

    NASA Astrophysics Data System (ADS)

    Watari, H.; Davey, K.; Rasgado, M. T. Alonso; Haga, T.; Koga, N.

    2004-06-01

    An experimental approach has been performed to ascertain the effectiveness of semi-solid strip casting using a horizontal twin roll caster. The demand for light-weight products with high strength has grown recently due to the rapid development of automobile and aircraft technology. One key to such development has been utilization of magnesium alloys, which can potentially reduce the total product weight. However, the problems of utilizing magnesium alloys are still mainly related to high manufacturing cost. One of the solutions to this problem is to develop magnesium casting-rolling technology in order to produce magnesium sheet products at competitive cost for commercial applications. In this experiment, magnesium alloy AZ31B was used to ascertain the effectiveness of semi-solid roll strip casting for producing magnesium alloy sheets. The temperature of the molten magnesium, and the roll speeds of the upper and lower rolls, (which could be changed independently), were varied to find an appropriate manufacturing condition. Rolling and heat treatment conditions were changed to examine which condition would be appropriate for producing wrought magnesium alloys with good formability. Microscopic observation of the crystals of the manufactured wrought magnesium alloys was performed. It has been found that a limiting drawing ratio of 2.7 was possible in a warm deep drawing test of the cast magnesium alloy sheets after being hot rolled.