The origin of high magnetic properties in (R,Zr)(Fe,Co)11.0–11.5Ti1.0–0.5Ny (y=1.0–1.4 for R=Nd, y=0 for R=Sm) compounds

International Nuclear Information System (INIS)

Kobayashi, K.; Suzuki, S.; Kuno, T.; Urushibata, K.; Sakuma, N.; Yano, M.; Shoji, T.; Kato, A.; Manabe, A.

2017-01-01

Ten alloys and nitrogenated compounds of (R,Zr)(Fe,Co) 11.0–11.5 Ti 1.0–0.5 N y (y=1.0–1.4 for R=Nd, y=0 for R=Sm) with a ThMn 12 -type structure were prepared. The average Fe–Fe interatomic distances, d(Fe–Fe), for Fe sites were calculated based on the reported atomic parameters. The hyperfine splittings (inner field (IF), in teslas) were measured by Mössbauer spectroscopy, and the IF increased with increasing d(Fe–Fe) for Fe sites, indicating a magneto-volume effect. The order of IF magnitude in Fe sites was Fe(8i)>Fe(8j)>Fe(8f) in all alloys. Co substitution for Fe sites, (Fe 0.75 Co 0.25 ), increased the IF by 25% for the R=Nd alloy and 15% for the R=Sm alloy. Decreasing Ti content from −Ti 1.0 to −Ti 0.5 , which increased the Fe and Co content, preserved the ThMn 12 structure with Zr substitution for R(2a) sites, and caused a slight increase in the IF of 2% for the R=Nd alloy and 7% for the R=Sm alloy. Nitrogenation, where N was introduced into the 2b sites, also increased IF in R=Nd alloys, by 23% for the Co- and Zr-free alloys, NdFe 11 Ti 1.0 N 1.5 , and by 7% for the Co-containing, (Nd 0.7 Zr 0.3 ) (Fe 0.75 Co 0.25 ) 11.5 Ti 0.5 N 1.3 alloy. The IF values of the R=Nd alloys were slightly larger than those of the R=Sm alloys. In conclusion, the magneto-volume effect was clearly observed at the Fe sites, and Co substitution into Fe sites and nitrogenation (R=Nd alloys) compensated for the increased IF. Increasing the Fe and Co fractions also increased IF slightly. - Highlights: • Average distances of Fe–Fe (d(Fe–Fe)) were calculated using lattice constants. • Hyperfine fields (IF) in Fe sites were measured using Mössbauer spectroscopy. • Relationship between d(Fe–Fe) and IF at each Fe site was obtained. • Co substitution and N introduction effects on IF was also measured. • Magneto-volume effect is main reason of IF augmentation in Fe sites.

Microstructure and magnetocaloric effect in cast LaFe11.5Si1.5Bx (x=0.5, 1.0)

International Nuclear Information System (INIS)

Zhang, H.; Long, Y.; Cao, Q.; Mudryk, Ya.; Zou, M.; Gschneidner, K.A.; Pecharsky, V.K.

2010-01-01

Phase formation, structure, and the magnetocaloric effect (MCE) in as-cast LaFe 11.5 Si 1.5 B x (x=0.5, 1.0) compounds have been studied. The Curie temperatures, T C , are ∼211 and 230 K for x=0.5 and 1.0, respectively, which are higher than that of annealed LaFe 11.5 Si 1.5 (T C =183 K), while the maximum magnetic entropy changes at the respective T C under a magnetic field change of 0-5 T are 7.8 and 5.8 J/(kg K). Wavelength dispersive spectrometry (WDS) analysis shows that only a small fraction of boron atoms is dissolved in the NaZn 13 -type structure phase, and that the compositions of the as-cast LaFe 11.5 Si 1.5 B x (x=0.5, 1.0) alloys are much different from the intended nominal compositions. These as-cast alloys exhibit second-order magnetic phase transitions and low MCEs. However, based on the relative cooling power, the as-cast LaFe 11.5 Si 1.5 B x alloys are promising candidates for magnetic refrigerants over a wide temperature range.

Ethylbenzene dehydrogenation over Mg3Fe0.5−xCoxAl0.5 catalysts derived from hydrotalcites: Comparison with Mg3Fe0.5−yNiyAl0.5 catalysts

KAUST Repository

Atanda, Luqman A.

2011-04-01

A series of Mg3Fe0.5-xCoxAl0.5 (x = 0-0.5) catalysts were prepared from hydrotalcite precursors and their activities in the dehydrogenation of ethylbenzene were compared with those of a series of Mg3Fe0.5-yNiyAl0.5 (y = 0-0.5) catalysts also derived from hydrotalcite. The hydrotalcites prepared by co-precipitation were calcined at 550 °C to the mixed oxides with a high surface area of 150-240m2gcat-1; they were composed of Mg(Fe,Me,Al)O periclase and Mg(Me)(Fe,Al)2O4 spinel (Me = Co or Ni). Bimetallic Fe3+-Co2+ system showed a synergy, i.e., an increase in the activity, whereas Fe3+-Ni2+ bimetallic system showed no synergy. The high styrene yield was obtained on Mg 3Fe0.1Co0.4Al0.5; however, a large substitution of Fe3+ with Co2+ caused a decrease in styrene selectivity along with coking on the catalysts, due to an isolation of CoOx on the catalyst surface. The highest yield as well as the highest selectivity for styrene production was obtained at x = 0.25 at time on stream of 30 min. The coprecipitation at pH = 10.0 and the composition of Mg3Fe0.25Co0.25Al0.5 were the best for preparing the active catalyst. This is partly due to the formation of a good hydrotalcite structure. On this catalyst, the active Fe3+ species was reduced at a low temperature by the Fe3+-Co2+ bimetal formation, leading to a high activity. Simultaneously, the amount of reducible Fe3+ was the smallest, resulting in a high stability of the active Fe3+ species. It is likely that the dehydrogenation was catalyzed by the reduction-oxidation between Fe3+ and Fe2+ and that Co2+ assisted the reduction-oxidation by forming Fe 3+-Co2+ (1/1) bimetallic active species. © 2011 Elsevier B.V. All rights reserved.

Mn{sub 0.5}Zn{sub 0.5}Fe{sub 2}O{sub 4} nanoparticles with high intrinsic loss power for hyperthermia therapy

Energy Technology Data Exchange (ETDEWEB)

Phong, P.T., E-mail: phamthanhphong@tdt.edu.vn [Department for Management of Science and Technology Development, Ton Duc Thang University, Ho Chi Minh City (Viet Nam); Faculty of Applied Sciences, Ton Duc Thang University, Ho Chi Minh City (Viet Nam); Nam, P.H., E-mail: namph.ims@gmail.com [Institute of Materials Science, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet Road, Cau Giay District, Ha Noi City (Viet Nam); Manh, D.H. [Institute of Materials Science, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet Road, Cau Giay District, Ha Noi City (Viet Nam); Lee, In-Ja, E-mail: lij@dongguk.ac.kr [Department of Advanced Materials Chemistry, Dongguk University-Gyeongju, Dongdae-ro 123, Gyeongju-Si, Gyeongbuk 38066 (Korea, Republic of)

2017-07-01

Highlights: • Mn{sub 0.5}Zn{sub 0.5}FeO{sub 4} nanoparticles were synthesized using a hydrothermal method. • The coercivity at different temperatures was studied using the mixed coercivity model. • A superspin glass from strong interactions. • High intrinsic loss power was found to be comparable to that of ferrite and some commercial ferrofluids. - Abstract: Nanosized mixed ferrite Mn{sub 0.5}Zn{sub 0.5}Fe{sub 2}O{sub 4} with crystalline size ∼15 nm has been prepared by hydrothermal route. XRD patterns confirm that the crystallites have single phase cubic spinel structure. The dynamic scaling analysis on the frequency dependence of spin glass-like transition temperature well explains the model of a transition at finite temperature. The analysis gives critical exponent and parameters as: zν = 10.48, T{sub 0} = 190 K, f{sub 0} = 5.38 × 10{sup 10} and this confirms the occurrence of spin glass-like transition in Mn{sub 0.5}Zn{sub 0.5}Fe{sub 2}O{sub 4} particles. The saturation magnetization and the coercivity change with temperature. The effective magnetic anisotropy constant of sample was calculated using the law of approach to saturation. The coercivity at different temperatures was deduced using the mixed coercivity model. The calculated coercivity results are in a good agreement with the experimental ones. The magnetic heating ability of Mn{sub 0.5}Zn{sub 0.5}Fe{sub 2}O{sub 4} magnetic fluid was studied with an induction heating system. The calculated intrinsic loss power (ILP) was 3.75 g nHm{sup 2}/kg. This study indicates that the resulting Mn{sub 0.5}Zn{sub 0.5}Fe{sub 2}O{sub 4} nanoparticles are promising materials in magnetic hyperthermia.

Structural and Moessbauer Effect Studies of 0.5Bi0.95Dy0.05FeO3-0.5Pb(Fe2/3W1/3)O3 Multiferroic

International Nuclear Information System (INIS)

Stoch, A.; Zachariasz, P.; Stoch, P.; Kulawik, J.; Maurin, J.

2011-01-01

A polycrystalline ceramic of 0.5Bi 0.95 Dy 0.05 FeO 3 -0.5Pb(Fe 2/3 W 1/3 )O 3 was synthesized from a solid-state reaction method. At room temperature material exhibits both magnetic and electric dipolar properties simultaneously. Detailed X-ray diffraction analysis and Moessbauer effect studies have been done to determine the crystallographic structure and magnetic properties of 0.5Bi 0.95 Dy 0.05 FeO 3 -0.5Pb(Fe 2/3 W 1/3 )O 3 . T N temperature was estimated at around 600 K. (authors)

Moessbauer study of (Fe1-x Cu x )4N (0.05≤x≤0.15) films

International Nuclear Information System (INIS)

El Khiraoui, S.; Sajieddine, M.; Vergnat, M.; Bauer, Ph.; Mabrouki, M.

2007-01-01

In this work, we have prepared nitrogenated Fe 1- x Cu x alloys by reactive evaporation under a flow of nitrogen ions. After annealing, X-ray diffraction shows that we have synthesized the γ'-(Fe 1- x Cu x ) 4 N (0.05≤x≤0.15) compounds. The films were investigated by Moessbauer spectroscopy. The crystallographic structure and the respective positions of the Fe and Cu atoms in the compounds have been determined

Different effect of quenching temperature on Fe1+σTe0.5Se0.5 and β-FeSe

Directory of Open Access Journals (Sweden)

Zhongnan Guo

2015-02-01

Full Text Available In this work, we have demonstrated a different effect on Fe1+σTe0.5Se0.5 and β-FeSe by changing the quenching temperature. Tc is clearly reduced in Fe1+σTe0.5Se0.5 after increasing the quenching temperature from 300 °C to 500 °C, while that of β-FeSe is almost unchanged. Structure refinement indicates that after quenched at 500 °C, FeTe4 tetrahedron exhibits an expansion with the stretched Fe-Te bond, together with the increased amount of interstitial iron. These particular changes on structure are believed to be responsible for the suppression of superconductivity in Fe1+σTe0.5Se0.5.

KARAKTERISTIK MIKROSTRUKTUR DAN FASA PADUAN Zr- 0,3%Nb-0,5%Fe-0,5%Cr PASCA PERLAKUAN PANAS DAN PENGEROLAN DINGIN

Directory of Open Access Journals (Sweden)

Sungkono Sungkono

2015-07-01

Full Text Available KARAKTERISTIK MIKROSTRUKTUR DAN FASA PADUAN Zr-0,3%Nb-0,5%Fe-0,5%Cr PASCA PERLAKUAN PANAS DAN PENGEROLAN DINGIN. Logam paduan Zr-Nb-Fe-Cr dikembangkan sebagai material kelongsong elemen bakar dengan fraksi bakar tinggi untuk reaktor daya maju. Dalam penelitian ini telah dibuat paduan Zr-0,3%Nb-0,5%Fe-0,5%Cr yang mendapat perlakuan panas pada temperatur 650 dan 750°C dengan waktu penahanan 1–2 jam. Tujuan penelitian adalah mendapatkan karakter paduan Zr-0,3%Nb-0,5%Fe-0,5%Cr pasca perlakuan panas dan pengerolan dingin yaitu mikrostruktur, struktur kristal dan fasa-fasa yang ada dalam paduan. Hasil penelitian menunjukkan bahwa paduan Zr-0,3%Nb-0,5%Fe-0,5%Cr pasca perlakuan panas (650ºC, 1-2 jam mempunyai struktur butir ekuiaksial dengan ukuran butir bertambah besar seiring dengan bertambahnya waktu penahanan. Sementara itu, pasca perlakuan panas (750ºC, 1-2 jam terjadi perubahan mikrostruktur paduan dari butir ekuiaksial dan kolumnar menjadi butir ekuiaksial lebih besar. Paduan Zr-0,3%Nb-0,5%Fe-0,5%Cr pasca perlakuan panas (650°C, 1 jam dan (750°C, 1 jam tidak dapat dirol dingin dengan reduksi tebal 5 – 10%, sedangkan pasca perlakuan panas (650ºC, 2 jam dan (750°C, 1.5-2 jam mampu menerima deformasi dingin dengan reduksi ketebalan 5-10% tanpa mengalami keretakan. Senyawa Zr2Fe, ZrCr2 dan FeCr teridentifikai dari hasil uji kristalografi paduan Zr-0,3%Nb-0,5%Fe-0,5%Cr.   MICROSTRUCTURE AND PHASE CHARACTERISTICSOF Zr-0.3%Nb-0.5%Fe-0.5%Cr ALLOY POST HEAT TREATMENT AND COLD ROLLING. Zr-Nb-Fe-Cr alloys was developed as fuel elements cladding with high burn up for advanced power reactors. In this research has been made of Zr-0.3% Nb-0.5% Fe-0.5% Cr alloy were heat treated with varying temperatures at650 and 750°C for 1 until 2 hours. The objectives of this research was to obtain the character of Zr-0.3% Nb-0.5% Fe-0.5% Cr alloy post heat treatment and cold rolling, microstructure nomenclature, crystal structure and phases that presents in the

Refinement in the structural and magnetic properties of Co{sub 0.5}Ni{sub 0.5}Fe{sub 2}O{sub 4} and its application as laser micro-propellant using ablation confinement

Energy Technology Data Exchange (ETDEWEB)

Raza Ahmad, Muhammad, E-mail: mrazaahmad@gmail.com [Centre for Advanced Studies in Physics (CASP), GC University, Lahore, Punjab (Pakistan); Jamil, Yasir, E-mail: yasirjamil@yahoo.com [Department of Physics, University of Agriculture, Faisalabad, Punjab (Pakistan); Tabasuum, Ayesha [Department of Physics, University of Agriculture, Faisalabad, Punjab (Pakistan); Hussain, Tousif [Centre for Advanced Studies in Physics (CASP), GC University, Lahore, Punjab (Pakistan)

2015-06-15

The transition metal-substituted cobalt ferrite nanoparticles Co{sub 0.5}X{sub 0.5}Fe{sub 2}O{sub 4} (with X=Cu, Zn, Mn and Ni) exhibit a wide range of properties that result in their application in low loss magnetic core materials, vertical recording heads, antenna rods, memory elements, ferrofluids, biomedical applications, sensors and laser propulsion. Keeping in view its importance we investigated for the first time the structural and magnetic properties of the Co{sub 0.5}Ni{sub 0.5}Fe{sub 2}O{sub 4} samples that were subsequently subjected to thermal treatments for different time durations. The average crystallite sizes of the synthesized samples were found in the range of 24–46 nm. The values of the saturation magnetization and coercivity varied from 25.7 to 31.2 emu/g and 523.59 to 927.62 O{sub e}, respectively. The XRD patterns showed that increase in thermal treatment time resulted in the refinement of the structure whereas the SEM micrographs depicted a uniform particle size distribution of the synthesized material. We also explored the application of the synthesized material as a micro-thruster. It was found that the confinement of the laser induced plasma of Co{sub 0.5}×{sub 0.5}Fe{sub 2}O{sub 4} led to an increase in the value of coupling coefficient from the range of 5.747×10{sup −5}–7.0644×10{sup −5} N-s/J for unconfined to that of 1.41×10{sup −4}–2.68×10{sup −4}N-s/J for confined plasma corresponding to the Nd:YAG laser fluencies of 4×10{sup 9} J/m{sup 2}–6×10{sup 9} J/m{sup 2}. - Highlights: • Thermal treatment modifies the properties of Co{sub 0.5}Ni{sub 0.5}Fe{sub 2}O{sub 4}. • Change in magnetic properties with increase in calcination time. • Confinement increases the laser propulsion parameters of Co{sub 0.5}Ni{sub 0.5}Fe{sub 2}O{sub 4}.

Structural and Moessbauer Effect Studies of 0.7Bi0.95Dy0.05FeO3-0.3Pb(Fe0.5Nb0.5)O3 Multiferroic

International Nuclear Information System (INIS)

Stoch, A.; Kulawik, J.; Stoch, P.; Maurin, J.; Zachariasz, P.

2011-01-01

0.7Bi 0.95 Dy 0.05 FeO 3 -0.3Pb(Fe 0.5 Nb 0.5 )O 3 is a multiferroic material which exhibits ferroelectric and antiferromagnetic ordering. In this paper the way of the synthesis of 0.7Bi 0.95 Dy 0.05 FeO 3 -0.3Pb(Fe 0.5 Nb 0.5 )O 3 is presented. The detailed X-ray and Moessbauer effect studies were done and crystal and hyperfine interaction parameters were obtained. (authors)

77 FR 12437 - Importation of Wooden Handicrafts From China

Science.gov (United States)

2012-03-01

... phytopathogenic fungi. Phytopathogenic fungi were determined to be likely to follow the pathway on wooden... minimally affected by this rule. Wooden handicrafts comprised a very small fraction of wood products... Collection Coordinator, at (301) 851-2908. List of Subjects in 7 CFR Part 319 Coffee, Cotton, Fruits, Imports...

Structure, nonstoichiometry, sintering and oxygen permeability of perovskite SrCo{sub 1−2x}(Fe,Nb){sub x}O{sub 3−δ} (x = 0.05, 0.10) oxides

Energy Technology Data Exchange (ETDEWEB)

Zhang, Jin Na [College of Chemistry and Materials Science, Liaoning University of Petroleum and Chemical Technology, Fushun 113001 (China); State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023 (China); Lu, Hui, E-mail: huilu@dicp.ac.cn [Greenhouse Gas Research Center, Climate Change Technology Research Division, Korea Institute of Energy Research, Daejeon 305-343 (Korea, Republic of); State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023 (China); Gui, Jian Zhou [College of Chemistry and Materials Science, Liaoning University of Petroleum and Chemical Technology, Fushun 113001 (China); Kim, Jong Pyo; Son, Sou Hwan [Greenhouse Gas Research Center, Climate Change Technology Research Division, Korea Institute of Energy Research, Daejeon 305-343 (Korea, Republic of); Park, Jung Hoon, E-mail: pjhoon@kier.re.kr [Greenhouse Gas Research Center, Climate Change Technology Research Division, Korea Institute of Energy Research, Daejeon 305-343 (Korea, Republic of)

2013-04-20

Highlights: ► The novel Fe/Nb co-substituted SrCo{sub 1−2x}(Fe,Nb){sub x}O{sub 3−δ} (x = 0.05, 0.10) oxides were characterized by the XRD, DSC, TG and SEM–EDS. ► The high structural stability of the co-substituted SrCo{sub 1−2x}(Fe,Nb){sub x}O{sub 3−δ} (x = 0.05, 0.10) oxides. ► The excellent oxygen permeation performance of the co-substituted SrCo{sub 1−2x}(Fe,Nb){sub x}O{sub 3−δ} (x = 0.10) membrane. -- Abstract: The novel Fe/Nb co-substituted SrCo{sub 1−2x}(Fe,Nb){sub x}O{sub 3−δ} (x = 0.05, 0.10) oxides have been synthesized and characterized by X-ray diffraction (XRD), differential scanning calorimetry (DSC), thermogravimetry (TG), and scanning electron microscopy (SEM). The XRD and DSC results demonstrate that the structural stability of the Fe/Nb co-substituted samples x = 0.05, 0.10 is improved greatly compared to the sample x = 0.00. The Fe/Nb co-doping in the SrCoO{sub 3−δ} oxide results in the improved structural stability of the SrCo{sub 1−2x}(Fe,Nb){sub x}O{sub 3−δ} (x = 0.05, 0.10) oxides. The nonstoichiometric and sintering properties were investigated by TG and SEM, and the oxygen permeation fluxes were measured at 800–950 °C for the sample x = 0.10. The improved oxygen permeability of the ceramic SrCo{sub 1−2x}(Fe,Nb){sub x}O{sub 3−δ} (x = 0.10) membrane compared to the (Ba{sub 0.5}Sr{sub 0.5})(Co{sub 0.8}Fe{sub 0.2})O{sub 3−δ} and SrCo{sub 0.8}Fe{sub 0.2}O{sub 3–δ} membranes, was observed under an air/He oxygen partial pressure gradient at 800–950 °C.

Measurement of N and C diffusion in Sm2Fe17 by magnetic relaxation

International Nuclear Information System (INIS)

Mommer, N.; Hirscher, M.; Gerlach, M.; Van Lier, J.; Kronmueller, H.; Kubis, M.; Mueller, K.-H.

1998-01-01

Magnetic after-effect (MAE) measurements of nitrided and carburized Sm 2 Fe 17 compounds were performed in the temperature range of 140 K to 480 K. Both nitrided and carburized compounds show relaxation maxima at 285 and 300 K, respectively, which are absent in pure Sm 2 Fe 17 compounds. Therefore, these relaxation maxima are attributed to jumps of interstitially dissolved nitrogen or carbon atoms. Numerical evaluation yielded an activation enthalpy Q N (0.84±0.05) eV and a pre-exponential factor τ 0 N =3.10 -15±1 s for the short-range diffusion of N atoms. The corresponding values for the carbon diffusion are Q C =(0.91±0.05) eV and τ 0 C =1.10 -15±1 s. The carbon and nitrogen content of the samples was determined from the increase in mass during nitrogenation or carburization to Sm 2 Fe 17 N 1.2 and Sm 2 Fe 17 C 2.6 . (orig.)

Ethylbenzene dehydrogenation over Mg3Fe0.5−xCoxAl0.5 catalysts derived from hydrotalcites: Comparison with Mg3Fe0.5−yNiyAl0.5 catalysts

KAUST Repository

Atanda, Luqman A.; Balasamy, Rabindran J.; Khurshid, Alam; Al-Ali, Ali A S; Sagata, Kunimasa; Asamoto, Makiko; Yahiro, Hidenori; Nomura, Kiyoshi; Sano, Tsuneji; Takehira, Katsuomi; Al-Khattaf, Sulaiman S.

2011-01-01

A series of Mg3Fe0.5-xCoxAl0.5 (x = 0-0.5) catalysts were prepared from hydrotalcite precursors and their activities in the dehydrogenation of ethylbenzene were compared with those of a series of Mg3Fe0.5-yNiyAl0.5 (y = 0-0.5) catalysts also derived

Synthesis, magnetization and photocatalytic activity of LaFeO{sub 3} and LaFe{sub 0.5}Mn{sub 0.5-x}O{sub 3-{delta}}

Energy Technology Data Exchange (ETDEWEB)

Wei, Zhi-Xian, E-mail: zx_wei@126.com [Beijing Institute of Protective Materials and Technology, Beijing 100081 (China); School of Materials Science and Engineering, Beijing Institute of Technology, Beijing 100081 (China); Department of Chemistry, Science Institute, North University of China, Taiyuan, Shanxi 030051 (China); Wang, Yan [Department of Chemistry, Chengde Teachers College for Nationalities, Chengde, Hebei 067000 (China); Liu, Ji-Ping, E-mail: liujp@bit.edu.cn [Beijing Institute of Protective Materials and Technology, Beijing 100081 (China); School of Materials Science and Engineering, Beijing Institute of Technology, Beijing 100081 (China); Xiao, Cai-Mei; Zeng, Wei-Wei [Department of Chemistry, Science Institute, North University of China, Taiyuan, Shanxi 030051 (China)

2012-10-15

Perovskite LaFe{sub 0.5}Mn{sub 0.5}O{sub 3-{delta}} and LaFeO{sub 3} were synthesized by stearic acid solution combustion method. The obtained powders were characterized by X-ray powder diffraction (XRD), Scanning electron microscopy (SEM), Fourier transform infrared (FT-IR), Vibrating sample magnetometer (VSM), XPS techniques and UV-vis absorption spectra techniques. The magnetic properties of the LaFeO{sub 3} and LaFe{sub 0.5}Mn{sub 0.5}O{sub 3-{delta}} were measured, and they were also evaluated for their photocatalytic activity towards the degradation of methyl orange (MO) under the sunlight irradiation. The experimental results show that the catalytic activities of the LaFe{sub 0.5}Mn{sub 0.5}O{sub 3-{delta}} were much higher than those of LaFeO{sub 3} due to its higher oxygen vacancies, variable valency Mn ions and the strong absorption in visible light. The optimum conditions for photocatalytic degradation MO using LaFe{sub 0.5}Mn{sub 0.5}O{sub 3-{delta}} were achieved. The ferromagnetism of the LaFe{sub 0.5}Mn{sub 0.5}O{sub 3-{delta}} could be caused by the Mn{sup 3+}/Fe{sup 3+} and Mn{sup 3+}/Mn{sup 4+}double exchange interaction, Mn{sup 3+}/Mn{sup 3+} superexchange interactions as well as the defective state in LaFe{sub 0.5}Mn{sub 0.5}O{sub 3-{delta}}. The LaFe{sub 0.5}Mn{sub 0.5}O{sub 3-{delta}} is applicable to the magnetic separation process for its lower coercivity (Hc) and remanent magnetization (Mr), and it can be reusable and maintain relatively high activity. -- Highlights: Black-Right-Pointing-Pointer The LaFe{sub 0.5}Mn{sub 0.5}O{sub 3-{delta}} is a bifunctional photocatalyst. Black-Right-Pointing-Pointer The origin of the ferromagnetism of the LaFe{sub 0.5}Mn{sub 0.5}O{sub 3-{delta}} is discussed. Black-Right-Pointing-Pointer LaFe{sub 0.5}Mn{sub 0.5}O{sub 3-{delta}} shows much higher photocatalytic activity than that of LaFeO{sub 3.} Black-Right-Pointing-Pointer LaFe{sub 0.5}Mn{sub 0.5}O{sub 3-{delta}} can be recycled by an external magnetic

hostel bedrooms after sunset

Directory of Open Access Journals (Sweden)

Sulaiman Shaharin Anwar

2017-01-01

Full Text Available After sunset, the indoor of buildings would be relatively warmer as compared to that of the outdoor due to thermal was associated with the heat stored in the building structures and furniture. In tropical countries, doors and windows are usually shut after sunset in order to avoid mosquitoes. Thus, the condition of the indoor air is worsened as the hot air is trapped inside the bedroom and takes long time to be fully dissipated to the surrounding. This causes discomfort to the occupants as bedrooms where they are expecting to have a good rest to rejuvenate from hard day works. The objective of this study was to analyze the nature of air temperature profile in bedrooms of a hostel at night and the effect of ventilation systems in reducing the indoor air temperature. The study was conducted by measuring temperature of air in the bedrooms throughout a night. It was found that the exhaust fan gave the best results by reducing the air temperature by 1.5°C to 2.5°C.

Television in the bedroom and increased body weight: potential explanations for their relationship among European schoolchildren.

Science.gov (United States)

Cameron, A J; van Stralen, M M; Brug, J; Salmon, J; Bere, E; Chinapaw, M J M; De Bourdeaudhuij, I; Jan, N; Manios, Y; Moreno, L A; Velde, S J

2013-04-01

A television in the bedroom is associated with measures of adiposity. We aimed to test if this association is mediated by any of (i) time spent watching television, (ii) sleep duration, (iii) physical activity level or (iv) consumption of soft drinks. Data were from 7234 boys and girls aged 10-12 years in European countries involved in the EuropeaN Energy balance Research to prevent excessive weight Gain among Youth project (Belgium, Greece, Hungary, the Netherlands, Norway, Slovenia and Spain). Waist circumference, height and weight were measured. The presence of a bedroom television, television viewing time, sleep duration, physical activity time and soft drink consumption were assessed by standardized questionnaires. Almost 40% of schoolchildren had a bedroom television, with the highest percentage among Hungarian children (65%) and lowest for Belgian, Slovenian and Spanish children (all ≈28%). A television in the bedroom was positively associated with time spent watching television, soft drink consumption and overweight and obesity (all P television in the bedroom and measures of body size was partly mediated by total television viewing time (proportion mediated for waist circumference 8.9%; for body mass index 8.3%) but not sleep duration, physical activity time or soft drink consumption. The strong association between a television in the bedroom and adiposity was at least partially mediated by television viewing time. The large proportion of European schoolchildren with a television in their bedroom is of concern. Parents should be aware of the potential consequences when placing a television in a child's bedroom and children should limit viewing time. © 2012 The Authors. Pediatric Obesity © 2012 International Association for the Study of Obesity.

Dielectric and piezoelectric properties of BiFeO3 modified Bi0.5Na0.5TiO3-Bi0.5K0.5TiO3 lead-free piezoelectric ceramics

International Nuclear Information System (INIS)

Zhou Changrong; Liu Xinyu; Li Weizhou

2008-01-01

The (0.82 - x)Bi 0.5 Na 0.5 TiO 3 -0.18Bi 0.5 K 0.5 TiO 3 -xBiFeO 3 (x = 0-0.07) lead-free piezoelectric ceramics were fabricated by a conventional solid-state reaction method and the effect of BiFeO 3 addition on microstructure and electrical properties of the ceramics was investigated. The specimens with x ≤ 0.05 maintained a rhombohedral-tetragonal phase coexistence and changed into a rhombohedral phase when x > 0.05 in crystal structure. The addition of BiFeO 3 caused a promoted grain growth. All the specimens reveal a low-frequency dielectric dispersion in the frequency range of 40-1 MHz. The piezoelectric constant d 33 and the electromechanical coupling factor k p show an obvious improvement by the addition of small amount of BiFeO 3 , which shows optimum values of d 33 = 170 pC/N and k p = 0.366 at x = 0.03. Contrary to the enhancement of piezoelectric properties, Q m decreases with increasing BiFeO 3 content. The mechanisms of intrinsic and extrinsic contributions to the dielectric and piezoelectric responses have been proposed. Intrinsic contributions are from the relative ion/cation shift that preserves the ferroelectric crystal structure. The remaining extrinsic contributions are from the domain-wall motion and point defects

Crystal structure and optical absorption spectra of Ga0.5Fe0.5InS3 and Ga0.5Fe0.25In1.25S3 crystals

International Nuclear Information System (INIS)

Gusejnov, G.G.; Musaeva, N.N.; Kyazumov, M.G.; Asadova, I.B.; Aliev, O.M.

2003-01-01

Single crystals of Ga 0.5 Fe 0.5 InS 3 are grown by the method of chemical gas-transport reactions and those of Ga 0.5 Fe 0.25 In 1.25 S 3 - by Bridgman method. X-ray diffraction studies reveal that they crystallize in trigonal and rhombohedral systems with lattice parameters of a = 3.796 x 2 A, c = 12.210 A, P3m1; a = 3.786 x 2 A, c = 36.606 A, R3m, respectively. An optical absorption edge in a wide range of photon energy and an energy gap width are determined: E g = 1.885 eV for Ga 0.5 Fe 0.5 InS 3 and E g 1.843 eV for Ga 0.5 Fe 0.25 In 1.25 S 3 [ru

Terahertz conductivity measurement of FeSe0.5Te0.5 and Co-doped BaFe2As2 thin films

International Nuclear Information System (INIS)

Nakamura, D.; Akiike, T.; Takahashi, H.; Nabeshima, F.; Imai, Y.; Maeda, A.; Katase, T.; Hiramatsu, H.; Hosono, H.; Komiya, S.; Tsukada, I.

2011-01-01

We investigated the THz conductivity of FeSe 0.5 Te 0.5 and Ba (Fe 2-x Co x )As 2 thin films. We estimated the superconducting gap energy values. We found anomolous conductivity spectrum in the antiferromagnetic phase. The terahertz (THz) conductivity of FeSe 0.5 Te 0.5 ('11'-type) and Co-doped BaFe 2 As 2 ('122'-type) thin films are investigated. For '11'-type, the frequency dependence of the complex conductivity can be understood as that of BCS-type superconductor near the superconducting gap energy, and we estimated the superconducting gap energy to be 0.6 meV. For '122'-type, we estimated the superconducting gap energy to be 2.8 meV, which is considered to be the superconducting gap opened at the electron-type Fermi surface near the M point.

Enhancement in electrical and magnetic properties with Ti-doping in Bi0.5La0.5Fe0.5Mn0.5O3

Science.gov (United States)

Singh, Rahul; Gupta, Prince Kumar; Kumar, Shiv; Joshi, Amish G.; Ghosh, A. K.; Patil, S.; Chatterjee, Sandip

2017-04-01

In this investigation, we have synthesized Bi0.5La0.5Fe0.5Mn0.5-xTixO3 (where x = 0 and 0.05) samples. The Rietveld refinement of X-ray diffraction (XRD) patterns shows that the systems crystallize in the orthorhombic phase with the Pnma space group. The observed Raman modes support the XRD results. The appearance of prominent A1-3 and weak E-2 modes in Bi0.5La0.5Fe0.5Mn0.45Ti0.05O3 indicates the presence of chemically more active Bi-O covalent bonds. Ferromagnetism of Bi0.5La0.5Fe0.5Mn0.5O3 is enhanced by Ti doping at the Mn-site, indicating that these particular samples might be interesting for device applications.

Characteristics associated with older adolescents who have a television in their bedrooms.

Science.gov (United States)

Barr-Anderson, Daheia J; van den Berg, Patricia; Neumark-Sztainer, Dianne; Story, Mary

2008-04-01

The goals were to examine the prevalence of adolescents having a television in their bedroom and to describe associated personal, social, and behavioral characteristics. Participants included 781 adolescents (mean age: 17.2 years) who completed a mailed Project Eating Among Teens II questionnaire. The relationships between adolescents having a television in their bedroom and sociodemographic, behavioral, and personal characteristics were examined. Nearly two thirds (62%) of participants had a bedroom television. Gender, race/ethnicity, socioeconomic status, and age were associated with the presence of a bedroom television. Compared with girls without a bedroom television, girls with a bedroom television reported less time spent in vigorous activity (1.8 vs 2.5 hours/week), more time spent watching television (20.7 vs 15.2 hours/week), lower vegetable intake (1.7 vs 2.0 servings per day), greater sweetened beverage consumption (1.2 vs 1.0 servings per day), and fewer family meals (2.9 vs 3.7 meals per week). Compared with boys without a bedroom television, boys with a bedroom television reported more time spent watching television (22.2 vs 18.2 hours/week), lower fruit intake (1.7 vs 2.2 servings per day), fewer family meals (2.9 vs 3.6 meals per week), and lower grade point average (2.6 vs 2.9). Twice as many youths with a television in their bedroom were heavy television users (watched >5 hours/day), compared with youths without a television in their bedroom (16% vs 8%). Adolescents with a bedroom television reported more television viewing time, less physical activity, poorer dietary habits, fewer family meals, and poorer school performance. Refraining from placing a television in teenagers' rooms may be a first step in helping to decrease screen time and subsequent poor behaviors associated with increased television watching.

APPRAISAL OF USED WOODEN RAILWAY SLEEPER

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SITI HAWA HAMZAH

2008-12-01

Full Text Available Replacement of wooden sleepers to prestressed concrete sleepers has marked as advancement in the railway sleepers industry in Malaysia. Despite superiority of these man-made composite sleepers, wooden sleepers still lead in terms of track performance qualities in particular on its natural elasticity. An initiative to investigate the degree of degradation of used wooden sleepers and the possibility of reusing them on low capacity railway track in Malaysia as a means of reducing the overall track rehabilitation cost was undertaken. Used wooden sleepers were tested according to Australian Standard, Railway Track Material, Prestressed Concrete Sleepers (AS 1085:14:2003 on Rail Seat Vertical Load Test and Centre Positive Bending Moment Test. Six wooden sleeper samples were tested under the static load until failure. Benchmarking was carried on high strength prestressed concrete sleeper, tested according to AS 1085:14:2003: Rail Seat - Positive Moment Test. The results obtained showed the maximum load that the used wooden sleepers can carry surpassed the design load of KTMB specifications and it is about 58% of high strength prestressed concrete sleeper.The maximum deflection produced by all used wooden sleepers is 20 mm showing that the sleepers maintained their elastic behaviour. Modulus of Elasticity ranging from 21 to 27 kN/mm2 of which within the standard value, indicating weathering process does not so much affect their stiffness. Most sleepers showed crack patterns propagated in the longitudinal direction. Toughness value is almost one half of the high strength prestressed concrete sleeper. This study indicates that there is a potential of reusing the wooden sleepers for light loading of the railway track. Hence, an extensive study is recommended to be carried out under fatigue loading condition.

Enhanced Microwave Absorption and Surface Wave Attenuation Properties of Co0.5Ni0.5Fe2O4 Fibers/Reduced Graphene Oxide Composites

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Yinrui Li

2018-03-01

Full Text Available Co0.5Ni0.5Fe2O4 fibers with a diameter of about 270 nm and a length of about 10 μm were synthesized by a microemulsion-mediated solvothermal method with subsequent heat treatment. The Co0.5Ni0.5Fe2O4 fibers/reduced graphene oxide (RGO composite was prepared by a facile in-situ chemical reduction method. The crystalline structures and morphologies were investigated based on X-ray diffraction patterns and scanning electron microscopy. Magnetization measurements were carried out using a vibrating sample magnetometer at room temperature. Co0.5Ni0.5Fe2O4 fibers/RGO composites achieve both a wider and stronger absorption and an adjustable surface wave attenuation compared with Co0.5Ni0.5Fe2O4 fibers, indicating the potential for application as advanced microwave absorbers.

Hot rolling effect on the characters of Zr-0.6Nb-0.5Fe-0.5Cr alloy

International Nuclear Information System (INIS)

Sungkono; Siti Aidah

2015-01-01

Characters of Zr-0.6Nb-0.5Fe-0.5Cr alloy after hot rolling have been studied. The objective of this research was to obtain of hot rolling effect on the characteristics of microstructures, hardness and phases formed in Zr-0.6Nb-0.5Fe-0.5Cr alloy. The hot rolling process of alloy carried out at temperature of 800 °C with retention time of 1.5 and 2 hours and a thickness reduction between 5 to 25 %. The results of this experiment showed that the Zr-0.6Nb-0.5Fe-0.5Cr alloy has Widmanstaetten structure with microstructure evolving into deformed columnar grains and deformed elongated grains with increasing thickness reduction. Besides, the longer the retention time at temperature of 800 °C is the larger are the grain structures and formation of α-Zr and Zr_3Fe phase. The hardness of Zr-0.6Nb-0.5Fe-0.5Cr alloy has same trends i.e the larger thickness reduction gives higher hardness. The Zr-0.6Nb-0.5Fe-0.5Cr alloy can under go hot rolling deformation at a thickness reduction of 25 % and the formation of α-Zr and Zr_3Fe can increased of hardness and strength of Zr-0.6 Nb-0.5 Fe-0.5 Cr alloy. (author)

BiFeO3-doped (Na0.5K0.5NbO3 lead-free piezoelectric ceramics

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Xueyi Sun et al

2008-01-01

Full Text Available Lead-free piezoelectric ceramics (1−x(Na0.5K0.5NbO3-xBiFeO3 (x=0~0.07 were synthesized by the solid-state reaction. Differential scanning calorimetry (DSC measurements revealed that an increase in the amount of BiFeO3 dopant resulted in a decrease in the orthorhombic-tetragonal and tetragonal-cubic phase transition temperature of the material. One percent BiFeO3 additive suppressed grain growth, which not only benefits the sintering of ceramics but also enhances the piezoelectric and ferroelectric properties, where d33=145pC/N, kp=0.31, Qm=80, Pr=11.3 μC cm−2 and Ec=16.5 kV cm−1. As xBF>0.01, both piezoelectric and ferroelectric properties decreased rapidly with an increasing amount of dopant.

Magnetic Properties of NdFe10Mo2-N Bonded Magnet

Science.gov (United States)

Zhang, Hong-Wei; Hu, Bo-Ping; Han, Zhong-Fan; Jin, Han-Min; Fu, Quan

1997-06-01

The dependence of remanence and coercivity on the magnetizing field is studied for isotropic and anisotropic epoxy resin bonded magnets. It was found that the coercivity of the NdFe10Mo2-N bonded magnet is mainly controlled by nucleation of reversed magnetic domains. Variation of iHc with Zn content and heat treatment conditions is studied. The value of 0 iHc obtained in the best Zn-bonded condition is about 0.15 T higher than before bonding. The variation of the amount of α-Fe with processing conditions is demonstrated for anisotropic Zn-bonded magnets.

78 FR 77419 - Certain Activated Carbon From the People's Republic of China; 2012-2013; Partial Rescission of...

Science.gov (United States)

2013-12-23

... for an administrative review on Shanxi Industry Technology Trading Co., Ltd., (``Shanxi ITT''), Shanxi... from Albemarle Corporation, dated April 30, 2013. \\5\\ See Wooden Bedroom Furniture From the People's...

Low temperature magnetic studies on PbFe{sub 0.5}Nb{sub 0.5}O{sub 3} multiferroic

Energy Technology Data Exchange (ETDEWEB)

Matteppanavar, Shidaling [Department of Physics, Bangalore University, Jnanabharati Campus, Bangalore 560056 (India); Angadi, Basavaraj, E-mail: brangadi@gmail.com [Department of Physics, Bangalore University, Jnanabharati Campus, Bangalore 560056 (India); Rayaprol, Sudhindra [UGC–DAE CSR, Mumbai Centre, B.A.R.C, R-5 Shed, Mumbai 400085 (India)

2014-09-01

PbFe{sub 0.5}Nb{sub 0.5}O{sub 3} (PFN), a well-known A(B′{sub 1/2}B″{sub 1/2})O{sub 3} type multiferroic, was successfully synthesized in single phase by a single step solid state reaction method. The single phase PFN was characterized through XRD, microstructure through SEM, and magnetic studies were carried out through a temperature dependent vibrating sample magnetometer (VSM) and neutron diffraction (ND) measurements. PFN exhibits a cusp at around 150 K in the temperature dependent magnetic susceptibility corresponding to the Néel temperature (T{sub N1}) and another peak around 10 K (T{sub N2}) corresponding to spin-glass like transition. In the temperature dependent ND studies, a magnetic Bragg peak appears at Q=1.35 Å{sup −1} (where Q=4πsinθ/λ, is called the scattering vector) below T{sub N} (150 K) implying antiferromagnetic (AFM) ordering in the system. On the basis of Rietveld analysis of the ND data at T=2 K, the magnetic structure of PFN could be explained by a G-type antiferromagnetic structure.

Crystal and magnetic study of the disordered perovskites Ca(Mn0.5Sb0.5)O3 and Ca(Fe0.5Sb0.5)O3

International Nuclear Information System (INIS)

Retuerto, M.; Martinez-Lope, M.J.; Garcia-Hernandez, M.; Munoz, A.; Fernandez-Diaz, M.T.; Alonso, J.A.

2010-01-01

We have investigated the double perovskites Ca 2 MSbO 6 (M = Mn, Fe) that have been prepared by solid-state reaction (M = Fe) and wet chemistry procedures (M = Mn). The crystal and magnetic structures have been studied from X-ray (XRD) and neutron powder diffraction (NPD) data. Rietveld refinements show that the crystal structures are orthorhombic (space group Pbnm) with complete disorder of M and Sb cations, so the formula should be rewritten as Ca(M 0.5 Sb 0.5 )O 3 . Due to this disorder no evidences of Jahn-Teller distortion can be observed in the MnO 6 octahedra of Ca(Mn 0.5 Sb 0.5 )O 3 , in contrast with the ordered double perovskite Sr 2 MnSbO 6 . Ca(Fe 0.5 Sb 0.5 )O 3 behaves as an antiferromagnet with an ordered magnetic moment for Fe 3+ of 1.53(4)μ B and a propagation vector k = 0, as investigated by low-temperature NPD. The antiferromagnetic ordering is a result of the high degree of Fe/Sb anti-site disorder of the sample, which originates the spontaneous formation of Fe-rich islands, characterized by the presence of strong Fe-O-Fe antiferromagnetic couplings with enough long-range coherence to produce a magnetic contribution perceptible by NPD. By contrast, the magnetic structure of Ca(Mn 0.5 Sb 0.5 )O 3 cannot be observed by low-temperature NPD because the magnitude of the ordered magnetic moments is below the detection threshold for neutrons.

Bedroom media: One risk factor for development.

Science.gov (United States)

Gentile, Douglas A; Berch, Olivia N; Choo, Hyekyung; Khoo, Angeline; Walsh, David A

2017-12-01

Mass media have numerous effects on children, ranging from influencing school performance to increased or reduced aggression. What we do not know, however, is how media availability in the bedroom moderates these effects. Although several researchers have suggested that bedroom media may influence outcomes by displacing other activities (the displacement hypothesis) or by changing the content of media consumed (the content hypothesis), these have rarely been tested directly. This study tested both hypotheses using several outcomes that are associated with bedroom media and some of the underlying mediating mechanisms. The hypotheses were tested using 3 longitudinal samples of varying methods, age, duration, and country. The results indicate that children who have bedroom media are likely to watch larger amounts of screen time which displaced important activities, such as reading and sleeping, which mediated later negative outcomes such as poor school performance. Bedroom media also influence risk for obesity and video game addiction. Children with bedroom media are also likely to be exposed to more media violence. The violent content increased normative beliefs about aggression, which increased physical aggression, providing support for the content hypothesis. This study demonstrates that media can have effects not just from what they show, but also because of what children are not exposed to. Bedroom media are therefore a robust risk factor for several aspects of child development. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Anomalous superconducting spin-valve effect in NbN/FeN/Cu/FeN/FeMn multilayers

Energy Technology Data Exchange (ETDEWEB)

Hwang, Tae Jong; Kim, Dong Ho [Yeungnam University, Gyeongsan (Korea, Republic of)

2017-09-15

We have studied magnetic and transport properties of NbN/FeN/Cu/FeN/FeMn spin-valve structure. In-plane magnetic moment exhibited typical hysteresis loops of spin valves in the normal state of NbN film at 20 K. On the other hand, the magnetic hysteresis loop in the superconducting state exhibited more complex behavior in which exchange bias provided by antiferrmagnetic FeMn layer to adjacent FeN layer was disturbed by superconductivity. Because of this, the ideal superconducting spin-valve effect was not detected. Instead the stray field originated from unsaturated magnetic states dominated the transport properties of NbN/FeN/Cu/FeN/FeMn multilayer.

Crystal structure and Mössbauer effect in multiferroic 0.5BiFeO3-0.5Pb(Fe0.5Ta0.5O3 solid solution

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Stoch Agata

2017-06-01

Full Text Available Multiferroic 0.5BiFeO3-0.5Pb(Fe0.5Ta0.5O3 solid solution is a material that exhibits ferroelectric and antiferromagnetic orderings in ambient temperature. The solid solution was obtained as a result of a conventional reaction in a solid state. The obtained material is a dense, fine-grained sinter whose surface was observed by scanning electron microscopy (SEM and stoichiometry was confirmed by energy dispersive X-ray spectroscopic (EDS analysis. According to the X-ray powder diffraction (XRD measurements, the main phase is R3c space group with admixture of Pm-3m regular phase. Small contribution of pyrochlore-like phase was also observed. Mössbauer spectroscopy suggested random distribution of Fe3+/Ta5+ cations in the B sites of ABO3 compound. Reduction of the magnetic hyperfine field with an increase in the substitution of Ta5+ in Fe3+ neighbourhood was also observed.

Measurement of N and C diffusion in Sm{sub 2}Fe{sub 17} by magnetic relaxation

Energy Technology Data Exchange (ETDEWEB)

Mommer, N.; Hirscher, M.; Gerlach, M.; Van Lier, J.; Kronmueller, H. [Max-Planck-Institut fuer Metallforschung, Stuttgart (Germany); Kubis, M.; Mueller, K.-H. [Institut fuer Festkoerper und Werkstofforschung, Institut fuer Metallische Werkstoffe, D-01171 Dresden (Germany)

1998-10-02

Magnetic after-effect (MAE) measurements of nitrided and carburized Sm{sub 2}Fe{sub 17} compounds were performed in the temperature range of 140 K to 480 K. Both nitrided and carburized compounds show relaxation maxima at 285 and 300 K, respectively, which are absent in pure Sm{sub 2}Fe{sub 17} compounds. Therefore, these relaxation maxima are attributed to jumps of interstitially dissolved nitrogen or carbon atoms. Numerical evaluation yielded an activation enthalpy Q{sup N} (0.84{+-}0.05) eV and a pre-exponential factor {tau}{sub 0}{sup N}=3.10{sup -15{+-}1} s for the short-range diffusion of N atoms. The corresponding values for the carbon diffusion are Q{sup C}=(0.91{+-}0.05) eV and {tau}{sub 0}{sup C}=1.10{sup -15{+-}1} s. The carbon and nitrogen content of the samples was determined from the increase in mass during nitrogenation or carburization to Sm{sub 2}Fe{sub 17}N{sub 1.2} and Sm{sub 2}Fe{sub 17}C{sub 2.6}. (orig.) 18 refs.

Cross sections for the reactions 54Fe(n,α)51Cr, 54Fe(n,p)54Mn, and 56Fe(n,p)56Mn

International Nuclear Information System (INIS)

Paulsen, A.; Widera, R.; Arnotte, F.; Liskien, H.

1979-01-01

Ratios of cross sections for the reactions 54 Fe(n,α) 51 Cr, 54 Fe(n,p) 54 Mn, and 56 Fe(n,p) 56 Mn were measured by the activation technique. In the 6- to 10-MeV energy range, quasi-monoenergetic neutrons produced by the D(d,n) source reaction were used, while additional data were obtained between 12 and 17 MeV by use of the T(d,n) source reaction. The cross-section ratios have accuracies between 1.5 and 4.5%. 1 figure, 3 tables

Crystal structure and optical absorption spectra of Ga{sub 0.5}Fe{sub 0.5}InS{sub 3} and Ga{sub 0.5}Fe{sub 0.25}In{sub 1.25}S{sub 3} crystals; Struktura i opticheskoe pogloshchenie kristallov Ga{sub 0.5}Fe{sub 0.5}InS{sub 3} i Ga{sub 0.5}Fe{sub 0.25}In{sub 1.25}S{sub 3}

Energy Technology Data Exchange (ETDEWEB)

Gusejnov, G G; Musaeva, N N; Kyazumov, M G [NAN Azerbajdzhana, Inst. Fiziki, Baku (Azerbaijan); Asadova, I B; Aliev, O M [NAN Azerbajdzhana, Inst. Neorganicheskoj i Fizicheskoj Khimii, Baku (Azerbaijan)

2003-09-01

Single crystals of Ga{sub 0.5}Fe{sub 0.5}InS{sub 3} are grown by the method of chemical gas-transport reactions and those of Ga{sub 0.5}Fe{sub 0.25}In{sub 1.25}S{sub 3} - by Bridgman method. X-ray diffraction studies reveal that they crystallize in trigonal and rhombohedral systems with lattice parameters of a = 3.796 x 2 A, c = 12.210 A, P3m1; a = 3.786 x 2 A, c = 36.606 A, R3m, respectively. An optical absorption edge in a wide range of photon energy and an energy gap width are determined: E{sub g} = 1.885 eV for Ga{sub 0.5}Fe{sub 0.5}InS{sub 3} and E{sub g} 1.843 eV for Ga{sub 0.5}Fe{sub 0.25}In{sub 1.25}S{sub 3}.

Large ferroelectric polarization of TiN/Hf0.5Zr0.5O2/TiN capacitors due to stress-induced crystallization at low thermal budget

Science.gov (United States)

Kim, Si Joon; Narayan, Dushyant; Lee, Jae-Gil; Mohan, Jaidah; Lee, Joy S.; Lee, Jaebeom; Kim, Harrison S.; Byun, Young-Chul; Lucero, Antonio T.; Young, Chadwin D.; Summerfelt, Scott R.; San, Tamer; Colombo, Luigi; Kim, Jiyoung

2017-12-01

We report on atomic layer deposited Hf0.5Zr0.5O2 (HZO)-based capacitors which exhibit excellent ferroelectric (FE) characteristics featuring a large switching polarization (45 μC/cm2) and a low FE saturation voltage (˜1.5 V) as extracted from pulse write/read measurements. The large FE polarization in HZO is achieved by the formation of a non-centrosymmetric orthorhombic phase, which is enabled by the TiN top electrode (TE) having a thickness of at least 90 nm. The TiN films are deposited at room temperature and annealed at 400 °C in an inert environment for at least 1 min in a rapid thermal annealing system. The room-temperature deposited TiN TE acts as a tensile stressor on the HZO film during the annealing process. The stress-inducing TiN TE is shown to inhibit the formation of the monoclinic phase during HZO crystallization, forming an orthorhombic phase that generates a large FE polarization, even at low process temperatures.

Spin canting and magnetic transition in NixZn1-xFe2O4 (x=0.0, 0.5 and 1.0) nanoparticles

Science.gov (United States)

Rani, Stuti; Raghav, Dharmendra Singh; Yadav, Prashant; Varma, G. D.

2018-04-01

Nanoparticles of NixZn1-xFe2O4(x=0.0, 0.5 and 1.0) have been synthesized via co-precipitation method and studied thestructural and magnetic properties. Rietveld refinement of X ray diffraction data of as synthesized samples revealthat the samples have mixed spinel structure with space group Fd-3m. The lattice parameter of the samples decreases as doping concentration of Ni ions increases. Magnetic measurements show paramagnetic to ferrimagnetic transition at room temperature on Ni doping in ZnFe2O4 nanoparticles. The magnetic measurements also show spin canting in samples possibly due to their nanocrystalline nature. The spin canting angles have been calculated with the help of Yafet-Kittel (Y-K) model. Furthermore, the Law of approach (LA) fitting of M-H curves indicates that the samples are highly anisotropicin nature. The Arrot plots of as synthesized samples also indicate the paramagnetic to ferrimagnetic transition. The correlation between the structural and observed magnetic properties of NixZn1-xFe2O4(x=0.0, 0.5 and 1.0) nanocrystals will be described and discussed in this paper.

Perpendicular magnetic anisotropy in Co2FeAl0.5Si0.5/MgO bottom electrodes for magnetic tunnel junctions

International Nuclear Information System (INIS)

Li, X.Q.; Wu, Y.; Gao, S.; Xu, X.G.; Miao, J.; Jiang, Y.

2013-01-01

Perpendicular magnetic anisotropy (PMA) was achieved in annealed Co 2 FeAl 0.5 Si 0.5 (CFAS)/MgO-based multilayers with good thermal stability up to 400 °C and a large anisotropy energy density K u over 2.0 × 10 5 J/m 3 . The thickness of the full-Heusler CFAS film to maintain PMA is up to 4.8 nm in which the co-existence of disordered A2, ordered B2 and fully ordered L2 1 structures is observed. X-ray photoelectron spectroscopy analysis demonstrates that the origin of the PMA is the hybridization between Co 3d and O 2p orbitals at the CFAS/MgO interface. - Highlights: • We achieved perpendicular magnetic anisotropy (PMA) in Co 2 FeAl 0.5 Si 0.5 (4.8 nm) film; • L2 1 , B2 and A2 phases coexist in perpendicular magnetic anisotropic Co 2 FeAl 0.5 Si 0.5 ; • Magnetic properties have strong dependence on the annealing temperature; • The PMA is induced by the hybridization between Co-3d and O-2p orbitals

Permanent magnets prepared from Sm{sub 10.5}Fe{sub 88.5}Zr{sub 1.0}N{sub y} without homogenization

Energy Technology Data Exchange (ETDEWEB)

Gebel, B.; Kubis, M.; Mueller, K.-H. [Institut fuer Festkoerper- und Werkstofforschung Dresden e.V. (Germany). Inst. fuer Metallische Werkstoffe

1997-10-01

In as-cast Sm{sub 2}Fe{sub 17} the high amount of {alpha}-Fe caused by a peritectic reaction can be considerably reduced by a small addition of about 1 at% Zr. X-ray diffraction showed that as-cast Sm{sub 10.5}Fe{sub 88.5}Zr{sub 1.0} mainly consists of a phase with the Th{sub 2}Zn{sub 17}-type structure and SmFe{sub 3}. Non-homogenized Sm{sub 10.5}Fe{sub 88.5}Zr{sub 1.0} was milled and (i) annealed in vacuum or (ii) treated with a hydrogenation-disproportionation-desorp tion-recombination (HDDR) process. The annealed and subsequently nitrogenated powder is magnetically anisotropic and has a coercivity {mu}{sub 0J}H{sub C} up to 2.0 T and an energy product (BH){sub max} up to 136 kJ/m{sup 3}. HDDR-treated and nitrogenated powder is isotropic and exhibits values of {mu}{sub 0J}H{sub C} = 3.1 T and (BH){sub max} 103 kJ/m{sup 3}. Consequently, Sm{sub 10.5}Fe{sub 88.5}Zr{sub 1.0}N{sub y} (y {approx} 16) permanent magnets with very good properties can be prepared without the time-consuming homogenization procedure. (orig.). 11 refs.

Study of the reaction of astrophysical interest 60Fe(n,γ)61Fe via (d,pγ) transfer reaction

International Nuclear Information System (INIS)

Giron, S.

2011-12-01

60 Fe is of special interest in nuclear astrophysics. Indeed the recent observations of 60 Fe characteristic gamma-ray lines by the RHESSI and INTEGRAL spacecrafts allowed to measure the total flux of 60 Fe over the Galaxy. Moreover the observation in presolar grains of an excess of the daughter-nuclei of 60 Fe, 60 Ni, gives constraints on the conditions of formation of the early solar system. However, the cross-sections of some reactions involved in 60 Fe nucleosynthesis and included to stellar models are still uncertain. The destruction reaction of 60 Fe, 60 Fe(n, γ) 61 Fe, is one of them. The total cross-section can be separate into two contributions: the direct one, involving states below the neutron separation threshold of 61 Fe, and the resonant one.We improved 61 Fe spectroscopy in order to evaluate the direct capture part of the 60 Fe(n, γ) 61 Fe reaction cross-section. 60 Fe(n, γ) 61 Fe was thus studied via d( 60 Fe, pγ) 61 Fe transfer reaction with the CATS/MUST2/EXOGAM setup at LISE-GANIL. DWBA analysis of experimental proton differential cross-sections allowed to extract orbital angular momentum and spectroscopic factors of different populated states identified below the neutron threshold. A comparison of experimental results for 61 Fe with experimental results for similar nuclei and with shell-model calculations was also performed. (author) [fr

Observation of magnetization and exchange bias reversals in NdFe{sub 0.5}Cr{sub 0.5}O{sub 3}

Energy Technology Data Exchange (ETDEWEB)

Sharannia, M.P.; De, Santanu [Department of Physics, Indian Institute of Technology Madras, Chennai 600036 (India); Singh, Ripandeep; Das, A. [Solid State Physics Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Nirmala, R. [Department of Physics, Indian Institute of Technology Madras, Chennai 600036 (India); Santhosh, P.N., E-mail: santhosh@iitm.ac.in [Department of Physics, Indian Institute of Technology Madras, Chennai 600036 (India)

2017-05-15

Polycrystalline NdFe{sub 0.5}Cr{sub 0.5}O{sub 3} has orthorhombic structure with Pnma space group and is magnetically ordered at room temperature as confirmed by neutron diffraction. The magnetic structure involves C{sub x}G{sub y}F{sub z} type ordering of Fe{sup 3+}/Cr{sup 3+} ions. NdFe{sub 0.5}Cr{sub 0.5}O{sub 3} shows magnetization reversal and sign reversal of exchange bias at ~16 K. Nd{sup 3+} moments that get induced by the internal field of |Fe+Cr| sublattice couple antiferromagnetically with the ferromagnetic component of |Fe+Cr| sublattice. Nd{sup 3+} moments overcome the |Fe+Cr| moments at ~16 K below which the material shows negative magnetization and positive exchange bias. - Highlights: • Neutron diffraction confirms magnetic ordering at 300 K in NdFe{sub 0.5}Cr{sub 0.5}O{sub 3}. • Magnetic structure involves C{sub x}G{sub y}F{sub z} type ordering of Fe{sup 3+}/Cr{sup 3+} ions. • Nd{sup 3+} moments couple antiferromagnetically with |Fe+Cr| ferromagnetic moments. • Shows magnetization reversal and exchange bias reversal.

EFECTO DEL ESPESOR EN LAS PROPIEDADES SUPERCONDUCTORAS Y ESTRUCTURALES DE PELÍCULAS DELGADAS DE FeSe0,5Te0,5

Directory of Open Access Journals (Sweden)

Oscar Rodríguez

2012-07-01

Full Text Available En este trabajo se investiga la influencia del espesor de la capa de FeSe0,5Te0,5 en las propiedades cristalinas y superconductoras de las películas depositadas sobre una capa buffer de hierro (Fe en sustratos de MgAl2O4, por el método de deposición por láser pulsado (PLD. El espesor de las capas superconductoras producidas son ~55nm y ~134nm. La película con menor espesor presenta mejores propiedades de textura (crecimiento orientado y una menor rugosidad superficial (RMS; verificadas por difracción de rayos X y AFM respectivamente. Esta misma película presenta una transición marcada al estado superconductor y una mayor temperatura crítica a diferencia de la película de mayor espesor. Se discute el efecto del espesor en las tensiones de la red superconductora.

Spin-glass behavior in single crystals of hetero-metallic magnetic warwickites MgFeBO{sub 4,} Mg{sub 0.5}Co{sub 0.5}FeBO{sub 4,} and CoFeBO{sub 4}

Energy Technology Data Exchange (ETDEWEB)

Arauzo, A., E-mail: aarauzo@unizar.es [Servicio de Medidas Físicas, Universidad de Zaragoza, Pedro Cerbuna 12, 50009 Zaragoza (Spain); Kazak, N.V. [L.V. Kirensky Institute of Physics, SB of RAS, 660036 Krasnoyarsk (Russian Federation); Ivanova, N.B. [Siberian Federal University, 660074 Krasnoyarsk (Russian Federation); Platunov, M.S. [L.V. Kirensky Institute of Physics, SB of RAS, 660036 Krasnoyarsk (Russian Federation); Knyazev, Yu.V. [Siberian Federal University, 660074 Krasnoyarsk (Russian Federation); Bayukov, O.A.; Bezmaternykh, L.N. [L.V. Kirensky Institute of Physics, SB of RAS, 660036 Krasnoyarsk (Russian Federation); Lyubutin, I.S.; Frolov, K.V. [Shubnikov Institute of Crystallography, RAS, 119333 Moscow (Russian Federation); Ovchinnikov, S.G. [L.V. Kirensky Institute of Physics, SB of RAS, 660036 Krasnoyarsk (Russian Federation); Siberian Federal University, 660074 Krasnoyarsk (Russian Federation); Siberian State Aerospace University, 660014 Krasnoyarsk (Russian Federation); Bartolomé, J. [Instituto de Ciencia de Materiales de Aragón, CSIC-Universidad de Zaragoza and Departamento de Física de la Materia Condensada, 50009 Zaragoza (Spain)

2015-10-15

Magnetic properties of heterometallic warwickites MgFeBO{sub 4,} Mg{sub 0.5}Co{sub 0.5}FeBO{sub 4,} and CoFeBO{sub 4} are presented, highlighting the effect of Co substitution on the magnetic properties of these compounds. The analysis of magnetization and heat capacity data has shown that these compounds exhibit a spin-glass transition below T{sub SG}=10, 20 and 22 K, respectively. Using zero field ac susceptibility as entanglement witness we find that the low dimensional magnetic behavior above T{sub SG} show quantum entanglement behavior χ(Τ)∝T{sup −α(Τ)} up to T{sub E}≈130 K. The α parameters have been deduced as a function of temperature and Co content, indicating the existence of random singlet phase in this temperature region. Above T{sub E} the paramagnetism is interpreted in terms of non-entangled spins giving rise to Curie–Weiss paramagnetism. The different intra- and inter-ribbon exchange interaction pathways have been calculated within a simple indirect coupling model. It is determined that the triangular motifs in the warwickite structure, together with the competing interactions, induce frustration. The spin-glass character is explained in terms of the substitutional disorder of the Mg, Fe and Co atoms at the two available crystallographic sites, and the frustration induced by the competing interactions. The Co substitution induces uniaxial anisotropy, increases the absolute magnetization and increases the spin-glass freezing temperature. The entanglement behavior is supported in the intermediate phase irrespective of the introduction of anisotropy by the Co substitution. - Highlights: • Spin-glass transition of MgFeBO{sub 4,} Mg{sub 0.5}Co{sub 0.5}FeBO{sub 4,} and CoFeBO{sub 4}. • Anisotropy and transition temperature T{sub SG} increases with Co substitution. • Dynamical scaling theory near T{sub SG} is fulfilled. • Quantum entanglement is observed in between T{sub SG} and T{sub E}=130 K. • Low dimensional random singlet phase

Synthesis and Characterization of Wooden Magnetic Activated Carbon Fibers with Hierarchical Pore Structures

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Dongna Li

2018-04-01

Full Text Available Wooden magnetic activated carbon fibers (WMACFs with hierarchical pore structures were obtained by adding magnetic iron oxide (Fe3O4 nanoparticles into the liquefied wood. The structures and properties of WMACFs were analyzed by scanning electronmicroscopy (SEM, X-ray diffraction (XRD, Fourier transform infrared spectroscopy (FTIR, N2 adsorption, and vibrating sample magnetometer (VSM. The results showed that WMACFs had high Brunauer-Emmett-Teller (BET surface area (1578 m2/g and total pore volume (0.929 cm3/g, of which 45% was the contribution of small mesopores of 2–3 nm. It is believed that Fe3O4 nanoparticles play an important role in the formation of hierarchical pores. With the Fe3O4 content increasing, the yield rate of WMACFs decreased, and the Fe3O4 crystal plane diffraction peaks and characteristic adsorption peaks were obviously observed. At the same time, it was also found that WMACFs had favorable magnetic properties when the Fe3O4 content was above 1.5%. As a result, WMACFs could be a promising candidate for high efficiency, low cost, and convenient separation for the magnetic field.

Structure-property correlation in PrFe0.5Mn0.5O2.95

International Nuclear Information System (INIS)

Ganeshraj, C.; Santhosh, P.N.; Sharma, Neetika; Das, A.; Mahendiran, R.

2014-01-01

PrFe 0.5 Mn 0.5 O 2.95 (PFMO) prepared by the conventional ceramic route is analyzed using a variety of techniques to understand the structural, magnetic and electrical properties. From the Neutron diffraction data it is concluded that PFMO crystallizes in an orthorhombic structure (Pnma). The magnetic structure can be represented as Γ 2 : C x G y F z , in Bertaut's notation, which has a net ferromagnetic moment along z-direction, and the spin component along x-direction (C x ) is found to be negligibly small. The canted G-type antiferromagnet PrFe 0.5 Mn 0.5 O 2.95 shows an enhanced Jahn-Teller (JT) distortion below 150 K (T*). The resistivity of the grains can be described by variable range hopping (VRH) between the localized states and there is a dominant grain boundary contribution to dc resistivity, below T*. Above T*, the total dc resistivity follows small polaron hopping (SPH) conduction. By means of complex impedance analysis, it is found that the observed giant dielectric response can be ascribed to Maxwell-Wagner polarization at the grain/grain boundary interfaces. Despite the low concentration of JT active Mn 3+ ions, our result indicates an important role of JT effect on physical properties of PrFe 0.5 Mn 0.5 O 2.95 . (author)

Effect of chitosan coating on the structural and magnetic properties of MnFe2O4 and Mn0.5Co0.5Fe2O4 nanoparticles

Science.gov (United States)

Mdlalose, W. B.; Mokhosi, S. R.; Dlamini, S.; Moyo, T.; Singh, M.

2018-05-01

We report the influence of polymer coatings on structural and magnetic properties of MnFe2O4 and Mn0.5Co0.5Fe2O4 nanoferrites synthesized by glycol thermal technique and then coated with chitosan viz. CHI-MnFe2O4 and CHI-Mn0.5Co0.5Fe2O4. The compounds were characterized by X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), high-resolution scanning electron microscopy (HRSEM), Mössbauer spectroscopy and magnetization measurements. The powder XRD patterns of naked nanoferrites confirmed single-phase spinel cubic structure with an average crystallite size of 13 nm, while the coated samples exhibited an average particle size of 15 nm. We observed a reduction in lattice parameters with coating. HRTEM results correlated well with XRD results. 57Fe Mössbauer spectra showed ordered magnetic spin states in both nanoferrites. This study shows that coatings have significant effects on the structural and magnetic properties of Mn-nanoferrites. Magnetization studies performed at room temperature in fields up to 14 kOe revealed the superparamagnetic nature of both naked and coated nanoparticles with spontaneous magnetizations at room temperature of 49.2 emu/g for MnFe2O4, 23.6 emu/g for coated CHI-MnFe2O4 nanoparticles, 63.2 emu/g for Mn0.5Co0.5Fe2O4 and 33.2 emu/g for coated CHI-Mn0.5Co0.5Fe2O4 nanoparticles. We observed reduction in coercive fields due to coating. Overall, chitosan-coated manganese and manganese-cobalt nanoferrites present as suitable candidates for biomedical applications owing to physicochemical, and magnetic properties exhibited.

On the novel double perovskites A2Fe(Mn0.5W0.5)O6 (A= Ca, Sr, Ba). Structural evolution and magnetism from neutron diffraction data

Science.gov (United States)

García-Ramos, Crisanto A.; Larrégola, Sebastián; Retuerto, María; Fernández-Díaz, María Teresa; Krezhov, Kiril; Alonso, José Antonio

2018-06-01

New A2Fe(Mn0.5W0.5)O6 (A = Ca, Sr, Ba) double perovskite oxides have been prepared by ceramic techniques. X-ray diffraction (XRD) complemented with neutron powder diffraction (NPD) indicate a structural evolution from monoclinic (space group P21/n) for A = Ca to cubic (Fm-3m) for A = Sr and finally to hexagonal (P63/mmc) for A = Ba as the perovskite tolerance factor increases with the A2+ ionic size. The three oxides present different tilting schemes of the FeO6 and (Mn,W)O6 octahedra. NPD data also show evidence in all cases of a considerable anti-site disordering, involving the partial occupancy of Fe positions by Mn atoms, and vice-versa. Magnetic susceptibility data show magnetic transitions below 50 K characterized by a strong irreversibility between ZFC and FC susceptibility curves. The A = Ca perovskite shows a G-type magnetic structure, with weak ordered magnetic moments due to the mentioned antisite disordering. Interesting magnetostrictive effects are observed for the Sr perovskite below 10 K.

Magnetic phase transition in MnFeP0.5As0.4Si0.1

International Nuclear Information System (INIS)

Wang, J L; Campbell, S J; Tegus, O; Brueck, E; Dou, S X

2010-01-01

We have carried out a detailed investigation of the magnetic phase transition in MnFeP 0.5 As 0.4 Si 0.1 . Temperature hysteresis has been observed in the variable temperature magnetization curves (B appl = 0.01 T) with T C W ∼ 302 K on warming and T C C ∼ 292 K on cooling. The first order nature of this transition in MnFeP 0.5 As 0.4 Si 0.1 is confirmed by the negative slope obtained from isotherms of M 2 versus B/M around the critical temperature. Linear thermal expansion measurements reveal a large volume change, ΔV/V∼8.7x10 -3 at the magnetic phase transition and that this magnetovolume effect is suppressed to ΔV/V ∼ 5.5x10 -3 in an applied field of B appl = 1.0 T. Analyses of 57 Fe Moessbauer spectra (4.5 - 300 K) using a random distribution model and taking nearest-neighbour environments into account, indicate that the paramagnetic and ferromagnetic phases coexist over a temperature range of ∼ 45 K around the Curie temperature. The Debye temperature for MnFeP 0.5 As 0.4 Si 0.1 has been evaluated as θ D = 350 ± 20 K from the temperature dependence of the average isomer shift.

Magnetic properties and EXAFS study of nanocrystalline Fe2Mn0.5Cu0.5Al synthesized using mechanical alloying technique

International Nuclear Information System (INIS)

Nanto, Dwi; Yang, Dong-Seok; Yu, Seong-Cho

2014-01-01

Nanocrystalline Fe 2 Mn 0.5 Cu 0.5 Al has been synthesized by the mechanical alloying technique and studied as a function of milling time. Alloy nature of Fe 2 Mn 0.5 Cu 0.5 Al was observed in a sample milled for 96 h. The magnetic saturation is 4.0 μ B /f.u., which coincidently follows Slater–Pauling rule at 5 K. Nanocrystalline Fe 2 Mn 0.5 Cu 0.5 Al has enhanced saturate magnetization compared to any other fabrication of Fe 2 MnAl reported. Cu element plays an important role in site competes with other elements and may result in the enhancement of saturate magnetization. In accordance to the magnetic results and EXAFS pattern, it was revealed that the dynamics of magnetic properties were confirmed as structural changes of nanocrystalline Fe 2 Mn 0.5 Cu 0.5 Al

Synthesis, structure and electrochemical properties of LiNaCo{sub 0.5}Fe{sub 0.5}PO{sub 4}F fluoride-phosphate

Energy Technology Data Exchange (ETDEWEB)

Fedotov, Stanislav S. [Department of Chemistry, Lomonosov Moscow State University, 119991 Moscow (Russian Federation); Skoltech Center for Electrochemical Energy Storage, Skolkovo Institute of Science and Technology, 143026 Moscow (Russian Federation); Kuzovchikov, Sergey M.; Khasanova, Nellie R.; Drozhzhin, Oleg A.; Filimonov, Dmitriy S. [Department of Chemistry, Lomonosov Moscow State University, 119991 Moscow (Russian Federation); Karakulina, Olesia M.; Hadermann, Joke [EMAT, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp (Belgium); Abakumov, Artem M. [Department of Chemistry, Lomonosov Moscow State University, 119991 Moscow (Russian Federation); Skoltech Center for Electrochemical Energy Storage, Skolkovo Institute of Science and Technology, 143026 Moscow (Russian Federation); EMAT, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp (Belgium); Antipov, Evgeny V. [Department of Chemistry, Lomonosov Moscow State University, 119991 Moscow (Russian Federation)

2016-10-15

LiNaCo{sub 0.5}Fe{sub 0.5}PO{sub 4}F fluoride-phosphate was synthesized via conventional solid-state and novel freeze-drying routes. The crystal structure was refined based on neutron powder diffraction (NPD) data and validated by electron diffraction (ED) and high-resolution transmission electron microscopy (HRTEM). The alkali ions are ordered in LiNaCo{sub 0.5}Fe{sub 0.5}PO{sub 4}F and the transition metals jointly occupy the same crystallographic sites. The oxidation state and oxygen coordination environment of the Fe atoms were verified by {sup 57}Fe Mössbauer spectroscopy. Electrochemical tests of the LiNaCo{sub 0.5}Fe{sub 0.5}PO{sub 4}F cathode material demonstrated a reversible activity of the Fe{sup 3+}/Fe{sup 2+} redox couple at the electrode potential near 3.4 V and minor activity of the Co{sup 3+}/Co{sup 2+} redox couple over 5 V vs Li/Li{sup +}. The material exhibited the discharge capacity of more than 82% (theo.) regarding Fe{sup 3+}/Fe{sup 2+} in the 2.4÷4.6 V vs Li/Li{sup +} potential range. - Graphical abstract: The ball-polyhedral representation of the LiNaCo{sub 0.5}Fe{sub 0.5}PO{sub 4}F crystal structure. The MO{sub 4}F{sub 2} units are depicted as blue octahedra, PO{sub 4} units as orange tetrahedra, sodium atoms are designated as yellow (Na1), lithium – red and brown (Li2, Li3 resp.), fluorine – green, oxygen – violet spheres. - Highlights: • Freeze-drying method was successfully applied to the synthesis of LiNaCo{sub 0.5}Fe{sub 0.5}PO{sub 4}F. • The crystal structure of LiNaCo{sub 0.5}Fe{sub 0.5}PO{sub 4}F was refined based on NPD and validated by ED and HRTEM. • LiNaCo{sub 0.5}Fe{sub 0.5}PO{sub 4}F demonstrated a reversible Li de/intercalation in the 2.5÷4.6 V vs Li/Li{sup +} range.

UV Light-Driven Photodegradation of Methylene Blue by Using Mn0.5Zn0.5Fe2O4/SiO2 Nanocomposites

Science.gov (United States)

Indrayana, I. P. T.; Julian, T.; Suharyadi, E.

2018-04-01

The photodegradation activity of nanocomposites for 20 ppm methylene blue solution has been investigated in this work. Nanocomposites Mn0.5Zn0.5Fe2O4/SiO2 have been synthesized using coprecipitation method. The X-ray diffraction (XRD) pattern confirmed the formation of three phases in sample Mn0.5Zn0.5Fe2O4/SiO2 i.e., Mn0.5Zn0.5Fe2O4, Zn(OH)2, and SiO2. The appearance of SiO2 phase showed that the encapsulation process has been carried out. The calculated particles size of Mn0.5Zn0.5Fe2O4/SiO2 is greater than Mn0.5Zn0.5Fe2O4. Bonding analysis via vibrational spectra for Mn0.5Zn0.5Fe2O4/SiO2 confirmed the formation of bonds Me-O-Si stretching (2854.65 cm-1) and Si-O-Si asymmetric stretching (1026.13 cm-1). The optical gap energy of Mn0.5Zn0.5Fe2O4/SiO2 was smaller (2.70 eV) than Mn0.5Zn0.5Fe2O4 (3.04 eV) due to smaller lattice dislocation and microstrain that affect their electronic structure. The Mn0.5Zn0.5Fe2O4/SiO2 showed high photodegradation ability due to smaller optical gap energy and the appearance of SiO2 ligand that can easily attract dye molecules. The Mn0.5Zn0.5Fe2O4/SiO2 also showed high degradation activity even without UV light radiation. The result showed that photodegradation reaction doesn’t follow pseudo-first order kinetics.

Fabrication and magnetic properties of Ni0.5Zn0.5Fe2O4 nanofibres by electrospinning

International Nuclear Information System (INIS)

Jun, Xiang; Xiang-Qian, Shen; Fu-Zhan, Song; Ming-Quan, Liu

2009-01-01

NiZn ferrite/polyvinylpyrrolidone composite fibres were prepared by sol–gel assisted electrospinning. Ni 0.5 Zn 0.5 Fe 2 O 4 nanofibres with a pure cubic spinel structure were obtained subsequently by calcination of the composite fibres at high temperatures. This paper investigates the thermal decomposition process, structures and morphologies of the electrospun composite fibres and the calcined Ni 0.5 Zn 0.5 Fe 2 O 4 nanofibres at different temperatures by thermo-gravimetric and differential thermal analysis, x-ray diffraction, Fourier transform infrared spectroscopy and field emission scanning electron microscopy. The magnetic behaviour of the resultant nanofibres was studied by a vibrating sample magnetometer. It is found that the grain sizes of the nanofibres increase significantly and the nanofibre morphology gradually transforms from a porous structure to a necklace-like nanostructure with the increase of calcination temperature. The Ni 0.5 Zn 0.5 Fe 2 O 4 nanofibres obtained at 1000 °C for 2 h are characterized by a necklace-like morphology and diameters of 100–200 nm. The saturation magnetization of the random Ni 0.5 Zn 0.5 Fe 2 O 4 nanofibres increases from 46.5 to 90.2 emu/g when the calcination temperature increases from 450 to 1000 °C. The coercivity reaches a maximum value of 11.0 kA/m at a calcination temperature of 600 °C. Due to the shape anisotropy, the aligned Ni 0.5 Zn 0.5 Fe 2 O 4 nanofibres exhibit an obvious magnetic anisotropy and the ease magnetizing direction is parallel to the nanofibre axis. (condensed matter: structure, thermal and mechanical properties)

The Magnetoelectric Effect of a Ni0.3Zn0.62Cu0.08Fe2O4 - PbFe0.5Nb0.5O3 Multilayer Composite

Directory of Open Access Journals (Sweden)

Guzdek P.

2014-10-01

Full Text Available The magnetoelectric effect in multiferroic materials has been widely studied for its fundamental interest and practical applications. The magnetoelectric effect observed for single phase materials like Cr2O3, BiFeO3, and Pb(Fe0.5Nb0.5O3 is usually small. A much larger effect can be obtained in composites consisting of magnetostrictive and piezoelectric phases. This paper investigates the magnetoelectric effect of a multilayer (laminated structure consisting of 6 nickel ferrite and 7 PFN relaxor layers. It describes the synthesis and tape casting process for Ni0.3Zn0.62Cu0.08Fe2O4 ferrite and relaxor PbFe0.5Nb0.5O3 (PFN. Magnetic hysteresis, ZFC - FC curves and dependencies of magnetization versus temperature for PFN relaxor and magnetoelectric composite were measured with a vibrating sample magnetometer (VSM in an applied magnetic field up to 85 kOe at a temperature range of 10 – 400 K. Magnetoelectric effect at room temperature was investigated as a function of a static magnetic field (0.3 - 6.5 kOe and the frequency of sinusoidal magnetic field (0.01 - 6.5 kHz. At lower magnetic field, the magnetoelectric coefficient increases slightly before reaching a maximum and then decreases. The magnetoelectric coefficient aME increases continuously as the frequency is raised, although this increase is less pronounced in the 1-6.5 kHz range. Maximum values of the magnetoelectric coefficient attained for the layered composites exceed about 50 mV/(Oe cm.

Local magnetic properties of multiferroic Nd0.5Gd0.5Fe3(BO3)4 in the excited states of Nd3+ ion

International Nuclear Information System (INIS)

Malakhovskii, A.V.; Gnatchenko, S.L.; Kachur, I.S.; Piryatinskaya, V.G.; Sukhachev, A.L.; Temerov, V.L.

2015-01-01

Polarized absorption spectra of single-crystal Nd 0.5 Gd 0.5 Fe 3 (BO 3 ) 4 were studied in the region of the transition 4 I 9/2 →( 4 G 5/2 + 2 G 7/2 ) in Nd 3+ ion as a function of temperature (2–34 K) and magnetic field (0–65 kOe). The spectra of natural circular dichroism were measured in the range of 5–40 K. It was found out that the local magnetic properties in the vicinity of the excited ion substantially depended on its state. In particular, a weak ferromagnetic moment appears in some excited states. It was found out that the selection rules for electron transitions in the magnetically ordered state substantially deviated from those in the paramagnetic state of the crystal. They are different for different transitions and they are very sensitive to the orientation of the sublattice magnetic moment relative to the light polarization. In the spectrum of the natural circular dichroism, the transition is revealed which is not observed in the absorption spectrum. - Highlights: • Temperature and field dependences of f-f transitions in Nd 0.5 Gd 0.5 Fe 3 (BO 3 ) 4 . • Natural circular dichroism in Nd 0.5 Gd 0.5 Fe 3 (BO 3 ) 4 below T N . • Weak ferromagnetic moment was identified in some excited 4f states. • Selection rules for f-f transitions substantially change below T N . • Intensities of f-f transitions strongly depend on magnetic moment orientation

Preparation and characterization of sputtered Fe1-xN x films

International Nuclear Information System (INIS)

Easton, E. Bradley; Buhrmester, Th.; Dahn, J.R.

2005-01-01

Iron nitride films have been prepared by reactive DC magnetron sputtering. The composition of Fe 1-x N x was varied over a range of 0 ≤ x ≤ 0.5 by controlling the nitrogen flow rate during sputtering. These films were characterized using powder X-ray diffraction (XRD), thermogravimetric and electron microprobe analysis. We found that the nitrogen content in the films increased with nitrogen gas partial pressure. XRD experiments revealed an evolution through the α-Fe, γ'-Fe 4 N, ε-Fe 2+z N, ζ-Fe 2 N, γ'''-FeN and γ'-FeN phases, when the nitrogen gas mole percentage was increased from 0% up to 70%. Above 70%, only the γ'-FeN phase was formed despite a measurable increase in the nitrogen content of the film with nitrogen gas partial pressure. Rietveld analysis of powder X-ray diffraction patterns revealed that this behavior is due to an increase in the nitrogen site occupation factor within the lattice

Characters of alloy Zr-0.4%Mo-0.5%Fe-0.5%Cr post heat treatment and cold rolling

International Nuclear Information System (INIS)

Sungkono; Siti Aidah

2014-01-01

Research and development of Zr-Mo-Fe-Cr alloys aimed to obtain PWR fuel element structure material with high burn up. In this study of the Zr-0.4%Mo-0.5%Fe-0.5%Cr alloys was prepared from zirconium sponge, molybdenum, iron and chromium powder. The alloy were heat treated at varying temperatures of 650 and 750 °C and retention time of 1, 1.5 and 2 hours. The objectives of this research was to obtain effect of thickness reduction on the character of Zr-0.4%Mo-0.5%Fe-0.5%Cr alloy. The results of this experiment showed that the microstructures of Zr-0.4%Mo-0.5%Fe-0.5%Cr alloy after heat treatment and cold rolling exhibits that the higher of the thickness reduction has applied on the alloy caused the microstructure to evolve from deformed equiaxial grains into flat bar grains and then into deformed flat bar grains. However, the higher of the temperature and the retention time then the larger grain structures so that the cold rolling causes the shape of the grains structure into a flat bar with a relatively larger size which affects the lower hardness. The Zr-0.4%Mo-0.5%Fe-0.5%Cr alloy after heat treatment (650-750°C; 1.5-2 hours) can undergo cold deformation without cracking at a thickness reduction between 5 to 15%. (author)

Crystal and magnetic study of the disordered perovskites Ca(Mn{sub 0.5}Sb{sub 0.5})O{sub 3} and Ca(Fe{sub 0.5}Sb{sub 0.5})O{sub 3}

Energy Technology Data Exchange (ETDEWEB)

Retuerto, M., E-mail: mretuerto@icmm.csic.es [Instituto de Ciencia de Materiales de Madrid, CSIC, Energia, Medio Ambiente y Tecnologias Sostenibles, Sor Juana Ines de la Cruz 3, Cantoblanco, E-28049 Madrid (Spain); Martinez-Lope, M.J.; Garcia-Hernandez, M. [Instituto de Ciencia de Materiales de Madrid, CSIC, Energia, Medio Ambiente y Tecnologias Sostenibles, Sor Juana Ines de la Cruz 3, Cantoblanco, E-28049 Madrid (Spain); Munoz, A. [Departamento de Fisica Aplicada, EPS, Universidad Carlos III, Avda. Universidad 30, E-28911 Leganes-Madrid (Spain); Fernandez-Diaz, M.T. [Institut Max Von Laue Paul Langevin, F-38042 Grenoble (France); Alonso, J.A. [Instituto de Ciencia de Materiales de Madrid, CSIC, Energia, Medio Ambiente y Tecnologias Sostenibles, Sor Juana Ines de la Cruz 3, Cantoblanco, E-28049 Madrid (Spain)

2010-10-15

We have investigated the double perovskites Ca{sub 2}MSbO{sub 6} (M = Mn, Fe) that have been prepared by solid-state reaction (M = Fe) and wet chemistry procedures (M = Mn). The crystal and magnetic structures have been studied from X-ray (XRD) and neutron powder diffraction (NPD) data. Rietveld refinements show that the crystal structures are orthorhombic (space group Pbnm) with complete disorder of M and Sb cations, so the formula should be rewritten as Ca(M{sub 0.5}Sb{sub 0.5})O{sub 3}. Due to this disorder no evidences of Jahn-Teller distortion can be observed in the MnO{sub 6} octahedra of Ca(Mn{sub 0.5}Sb{sub 0.5})O{sub 3}, in contrast with the ordered double perovskite Sr{sub 2}MnSbO{sub 6}. Ca(Fe{sub 0.5}Sb{sub 0.5})O{sub 3} behaves as an antiferromagnet with an ordered magnetic moment for Fe{sup 3+} of 1.53(4){mu}{sub B} and a propagation vector k = 0, as investigated by low-temperature NPD. The antiferromagnetic ordering is a result of the high degree of Fe/Sb anti-site disorder of the sample, which originates the spontaneous formation of Fe-rich islands, characterized by the presence of strong Fe-O-Fe antiferromagnetic couplings with enough long-range coherence to produce a magnetic contribution perceptible by NPD. By contrast, the magnetic structure of Ca(Mn{sub 0.5}Sb{sub 0.5})O{sub 3} cannot be observed by low-temperature NPD because the magnitude of the ordered magnetic moments is below the detection threshold for neutrons.

Slurry Erosion Behavior of AlxCoCrFeNiTi0.5 High-Entropy Alloy Coatings Fabricated by Laser Cladding

Directory of Open Access Journals (Sweden)

Jianhua Zhao

2018-02-01

Full Text Available High-entropy alloys (HEAs have gained extensive attention due to their excellent properties and the related scientific value in the last decade. In this work, AlxCoCrFeNiTi0.5 HEA coatings (x: molar ratio, x = 1.0, 1.5, 2.0, and 2.5 were fabricated on Q345 steel substrate by laser-cladding process to develop a practical protection technology for fluid machines. The effect of Al content on their phase evolution, microstructure, and slurry erosion performance of the HEA coatings was studied. The AlxCoCrFeNiTi0.5 HEA coatings are composed of simple face-centered cubic (FCC, body-centered cubic (BCC and their mixture phase. Slurry erosion tests were conducted on the HEA coatings with a constant velocity of 10.08 m/s and 16–40 meshs and particles at impingement angles of 15, 30, 45, 60 and 90 degrees. The effect of three parameters, namely impingement angle, sand concentration and erosion time, on the slurry erosion behavior of AlxCoCrFeNiTi0.5 HEA coatings was investigated. Experimental results show AlCoCrFeNiTi0.5 HEA coating follows a ductile erosion mode and a mixed mode (neither ductile nor brittle for Al1.5CoCrFeNiTi0.5 HEA coating, while Al2.0CoCrFeNiTi0.5 and Al2.5CoCrFeNiTi0.5 HEA coatings mainly exhibit brittle erosion mode. AlCoCrFeNiTi0.5 HEA coating has good erosion resistance at all investigated impingement angles due to its high hardness, good plasticity, and low stacking fault energy (SFE.

Synthesis of homogeneous Ca0.5Sr0.5FeO2.5+δ compound using a mirror furnace method

International Nuclear Information System (INIS)

Mahboub, M.S.; Zeroual, S.; Boudjada, A.

2012-01-01

Graphical abstract: X-ray diffraction pattern indexing of Ca 0.5 Sr 0.5 FeO 2.5+δ powder sample obtained by mirror furnace method after thermal treatment. Highlights: ► A homogenous compound Ca 0.5 Sr 0.5 FeO 2.5+δ has been synthesized for the first time by a mirror furnace method. ► Ca 0.5 Sr 0.5 FeO 2.5+δ powder sample is perfectly homogenous, confirmed by X-ray diffraction, Raman spectroscopy and EDS technique. ► The thermal treatment of Ca 0.5 Sr 0.5 FeO 2.5+δ powder sample can increase their average grain sizes. -- Abstract: A new synthesis method using melting zone technique via the double mirror furnace around 1600 °C is used to obtain homogenous brownmillerite compounds Ca 1−x Sr x FeO 2.5+δ in the range 0.3 ≤ x ≤ 0.7. These compounds play important role in understanding the mystery of the oxygen diffusion in the perovskite-related oxides. We have successfully solved the miscibility gap problem by synthesizing a good quality of homogenous powder samples of Ca 0.5 Sr 0.5 FeO 2.5+δ compound. Our result was confirmed by X-rays diffraction, Raman spectroscopy and energy dispersive spectroscopy analysis. Thermal treatment was also applied until 800 °C under vacuum to confirm again the homogeneity of powder samples, improve its quality and show that no decomposition or return to form Ca- and Sr-enriched microdomains takes place as a result of phase separation.

Depairing current density of Ba0.5K0.5Fe1.95Co0.05As2 microbridges with nanoscale thickness

International Nuclear Information System (INIS)

Li, Jun; Yuan, Jie; Ge, Jun-Yi; Ji, Min; Feng, Hai-Luke; Yuan, Ya-Hua; Hatano, Takeshi; Vanacken, Johan; Yamaura, Kazunari; Wang, Hua-Bing

2014-01-01

Highlights: • The critical current density of Ba 0.5 K 0.5 Fe 1.95 Co 0.05 As 2 microbridges is 7.9 MA/cm 2 at 21 K. • The critical current is in consistence with the Ginzburg–Landau depairing limit. • The depairing current density is less than that of impurity-free crystal. - Abstract: We investigated the depairing current density of Ba 0.5 K 0.5 Fe 1.95 Co 0.05 As 2 microbridges with width of 2 μm and thickness of 150 nm. The current vs. voltage characteristics of the microbridges show a Josephson-like behavior with the obvious hysteresis. The critical current density was observed as J c = 7.9 MA/cm 2 at temperature 21 K, which is consistent with the Ginzburg–Landau depairing limit. However, the depairing current density is less than that of impurity-free crystal, although the Co ions provide additional pinning centers within the superconducting Fe 2 As 2 layers. The Co impurity also enhances the anisotropic factor of the critical current density by 1.3 (1 T) or 1.7 (3 T)

Impact sound insulation improvement of wooden floors on concrete slabs

DEFF Research Database (Denmark)

Rasmussen, Birgit; Hoffmeyer, Dan; Hansen, Rói

2014-01-01

renovating housing. In Denmark, there are about 1 million dwellings in multi-storey housing. About half of the dwellings are built with timber floors, and the other half with wooden floors on concrete slabs, either in-situ cast or prefabricated hollow-core elements. In a project including mapping of sound......Improvement of impact sound insulation is one of the major challenges, when renovating housing. In Denmark, building regulations for impact sound in new-build were strengthened 5 dB in 2008, implying a main requirement L’n,w ≤ 53 dB between dwellings. The same value should also be a goal, when...... insulation in the Danish housing stock and investigation of improvement possibilities, a pilot laboratory study of wooden floors on concrete was carried out. The laboratory study included impact sound improvement measurements of full-scale samples (10 m2) fulfilling the conditions in EN ISO 10140...

Influence of substrate type on transport properties of superconducting FeSe0.5Te0.5 thin films

International Nuclear Information System (INIS)

Yuan, Feifei; Shi, Zhixiang; Iida, Kazumasa; Langer, Marco; Hänisch, Jens; Hühne, Ruben; Schultz, Ludwig; Ichinose, Ataru; Tsukada, Ichiro; Sala, Alberto; Putti, Marina

2015-01-01

FeSe 0.5 Te 0.5 thin films were grown by pulsed laser deposition on CaF 2 , LaAlO 3 and MgO substrates and structurally and electro-magnetically characterized in order to study the influence of the substrate on their transport properties. The in-plane lattice mismatch between FeSe 0.5 Te 0.5 bulk and the substrate shows no influence on the lattice parameters of the films, whereas the type of substrate affects the crystalline quality of the films and, therefore, the superconducting properties. The film on MgO showed an extra peak in the angular dependence of critical current density J c (θ) at θ = 180° (H||c), which arises from c-axis defects as confirmed by transmission electron microscopy. In contrast, no J c (θ) peaks for H||c were observed in films on CaF 2 and LaAlO 3 . J c (θ) can be scaled successfully for both films without c-axis correlated defects by the anisotropic Ginzburg–Landau approach with appropriate anisotropy ratio γ J . The scaling parameter γ J is decreasing with decreasing temperature, which is different from what we observed in FeSe 0.5 Te 0.5 films on Fe-buffered MgO substrates. (paper)

Unraveling the magnetic properties of BiFe0.5Cr0.5O3 thin films

Directory of Open Access Journals (Sweden)

G. Vinai

2015-11-01

Full Text Available We investigate the structural, chemical, and magnetic properties on BiFe0.5Cr0.5O3 (BFCO thin films grown on (001 (110 and (111 oriented SrTiO3 (STO substrates by x-ray magnetic circular dichroism and x-ray diffraction. We show how highly pure BFCO films, differently from the theoretically expected ferrimagnetic behavior, present a very weak dichroic signal at Cr and Fe edges, with both moments aligned with the external field. Chemically sensitive hysteresis loops show no hysteretic behavior and no saturation up to 6.8 T. The linear responses are induced by the tilting of the Cr and Fe moments along the applied magnetic field.

Current perception of wooden building in Slovenia

OpenAIRE

Kitek Kuzman , Manja; Hrovatin, Jasna

2007-01-01

In residential buildings, prefabricated wooden houses constitute minor part ofall buildings in Slovenia. The reasons pertaining to the relatively low occurrence of prefabricated wooden buildings today are assessed in the presentstudy. The Slovenian public opinion survey on wooden building 2006 examined, among other issues, public attitude towards wooden buildings and itsadvantages. Data collection was performed by CATI method. Results of publicresearch clearly indicate the users' lack of know...

Microstructure, AC impedance and DC electrical conductivity characteristics of NiFe2-xGdxO4 (x = 0, 0.05 and 0.075

Directory of Open Access Journals (Sweden)

K. Kamala Bharathi

2012-03-01

Full Text Available The structure and electrical characteristics of Gd doped Ni ferrite materials, namely NiFe1.95Gd0.05O4 and NiFe1.925Gd0.075O4, are reported to demonstrate their improved electrical properties compared to that of pure NiFe2O4. NiFe1.95Gd0.05O4 and NiFe1.925Gd0.075O4 compounds crystallize in the cubic inverse spinel phase with a very small amount of GdFeO3 additional phase while pure NiFe2O4 crystallize in inverse spinel phase without any impurity phase. The back scattered electron imaging analysis indicate the primary and secondary formation in NiFe1.95Gd0.05O4 and NiFe1.925Gd0.075O4 compounds. Atomic force microscopy measurements indicate that the bulk grains are ∼2-5 micron size while the grain boundaries are thin compared to bulk grains. Impedance spectroscopic analysis at different temperature indicates the different relaxation mechanisms and their variation with temperature, bulk grain and grain-boundary contributions to the electrical conductivity (Rg and capacitance (Cg of these materials. The conductivity in pure NiFeO4 is found to be predominantly due to intrinsic bulk contribution (Rg=213 kΩ and Cg=4.5 x 10-8 F. In the case of NiFe1.95Gd0.05O4 and NiFe1.925Gd0.075O4 compounds, grain and grain-boundary contributions to the conductivity are clearly observed. The DC conductivity values (at 300 K of NiFe2O4, NiFe1.95Gd0.05O4 and NiFe1.925Gd0.075O4 compounds are found to be 1.06 x 10-7 Ω-1 cm-1, 5.73 x 10-8 Ω-1 cm-1 and 1.28 x 10-8 Ω-1 cm-1 respectively.

Fe-N and (Fe, Ni)-N Fine Powders for Magnetic Recording

International Nuclear Information System (INIS)

Chen Ziyu; Li Fashen

1998-01-01

Combining Moessbauer spectroscopy with magnetic property measurement, we have studied Fe-N and (Fe, Ni)-N powders for magnetic recording. The typical particles of the core (α-Fe)/shell (γ'-Fe 4 N) structure have been successfully prepared. All the products are stabilized in a multi-organic solution. It has been found that the coercivity can be changed from 300 to 800 Oe by adjusting the shape of the particles. The special saturation magnetization of the particles can be adjusted from 120 to 180emu/g and their chemical stability is improved by substituting nickel for iron in γ'-Fe 4 N. Following experiments for corrosion resistance, it is expected that (Fe, Ni)-N and the core/shell particles will be applied as recording media in the near future

Fe-N and (Fe, Ni)-N Fine Powders for Magnetic Recording

Energy Technology Data Exchange (ETDEWEB)

Chen Ziyu; Li Fashen [Lanzhou University, Department of Physics (China)

1998-12-15

Combining Moessbauer spectroscopy with magnetic property measurement, we have studied Fe-N and (Fe, Ni)-N powders for magnetic recording. The typical particles of the core ({alpha}-Fe)/shell ({gamma}'-Fe{sub 4}N) structure have been successfully prepared. All the products are stabilized in a multi-organic solution. It has been found that the coercivity can be changed from 300 to 800 Oe by adjusting the shape of the particles. The special saturation magnetization of the particles can be adjusted from 120 to 180emu/g and their chemical stability is improved by substituting nickel for iron in {gamma}'-Fe{sub 4}N. Following experiments for corrosion resistance, it is expected that (Fe, Ni)-N and the core/shell particles will be applied as recording media in the near future.

Fe/N/C hollow nanospheres by Fe(iii)-dopamine complexation-assisted one-pot doping as nonprecious-metal electrocatalysts for oxygen reduction

Science.gov (United States)

Zhou, Dan; Yang, Liping; Yu, Linghui; Kong, Junhua; Yao, Xiayin; Liu, Wanshuang; Xu, Zhichuan; Lu, Xuehong

2015-01-01

. Moreover, it displays better electrochemical durability and tolerance to methanol crossover effect in an alkaline medium than the Pt/C. The excellent catalytic performance of Fe/N/C HNSs-750 towards ORR can be ascribed to their high specific surface area, mesoporous morphology, homogeneous distribution of abundant active sites, high pyridinic nitrogen content, graphitic nitrogen and graphitic carbon, as well as the synergistic effect of nitrogen and iron species for catalyzing ORR. Electronic supplementary information (ESI) available: Fig. S1 FESEM and TEM images of Fe3+-PDA@SiO2 prepared with different amounts of FeCl3 and Fig. S2 CV and polarization curves of Fe/N/C HNSs-750 in 0.5 M H2SO4 solution. See DOI: 10.1039/c4nr06366j

Quemaduras por frío: Revisión de 10 Años

OpenAIRE

EULUFÍ M, ALEX; PIÑEROS B, JOSÉ LUIS; CALDERÓN O, WILFREDO; CUADRA C, ÁLVARO; DANILLA E, STEFAN; LÉNIZ M, PATRICIO; ROCO M, HÉCTOR; ROA G, RICARDO; EULUFÍ M, CHRISTIAN

2006-01-01

La injuria por frío ha sido objeto de estudio desde la década de 1960, Este trabajo entrega los resultados de una revisión retrospectiva de un grupo de 10 pacientes ingresados al Hospital del Trabajador de Santiago (HTS) en un periodo de 10 años producto de accidentes laborales de distintas etiologías. Cabe señalar que solo encontramos reportes aislados de casos en la literatura revisada. Se revisaron retrospectivamente las fichas clínicas de 10 pacientes en el periodo 1993-2003. Las edades f...

Production of 26Al by spallation of Fe, Si, Al nuclei

International Nuclear Information System (INIS)

Paillard, P.

1977-01-01

Cross sections for 7 Be, 10 Be and 26 Al formation in Al, Si and Fe targets bombarded with 0.6 and 24GeV protons have been measured by using highly selective chemical separation and low level background counters. Results for 26 Al at 0.6GeV are in mb: 17.9 + or - 2.7 in Al, 12.5 + or - 2.5 in Si and 0.45 + or - 0.14 in Fe; at 24GeV 2.6 + or - 0.5mb in Fe. Results for 10 Be are not valid on account of experimental difficulties. It is deduced from these values of aluminium in cosmic ray propagation that 26 Al is not yet cosmic ray chronometer [fr

Growth and characterization of Fe nanostructures on GaN

International Nuclear Information System (INIS)

Honda, Yuya; Hayakawa, Satoko; Hasegawa, Shigehiko; Asahi, Hajime

2009-01-01

We have investigated the growth of Fe nanostructures on GaN(0 0 0 1) substrates at room temperature using reflection high-energy electron diffraction (RHEED), scanning tunneling microscopy (STM), and superconducting quantum interference device magnetometer. Initially, a ring RHEED pattern appears, indicating the growth of polycrystalline α-Fe. At around 0.5 nm deposition, the surface displays a transmission pattern from α-Fe films with the epitaxial relationship of Fe(1 1 0)//GaN(0 0 0 1) and Fe[1 -1 1]//GaN[1 1 -2 0] (Kurdjumov-Sachs (KS) orientational relationship). Further deposition to 1 nm results in the appearance of a new spot pattern together with the pattern from domains with the KS orientation relationship. The newly observed pattern shows that Fe layers are formed with the epitaxial relationship of Fe(1 1 0)//GaN(0 0 0 1) and Fe[0 0 1]//GaN[1 1 -2 0] (Nishiyama-Wasserman (NW) orientational relationship). From STM images for Fe layers with the KS and NW orientational relationships, it can be seen that Fe layers with the KS relationship consist of round-shaped Fe nanodots with below 7 nm in average diameter. These nanodots coalesce to form nanodots elongating along the Fe[1 0 0] direction, and they have the KS orientational relationship. Elongated Fe nanodots with the NW relationship show ferromagnetism while round-shaped Fe nanodots with the KS relationship show super-paramagnetic behavior. We will discuss their magnetic properties in connection with the change in crystalline configurations of nanodots.

Dependence of magnetic and structural properties of Ni 0.5 M 0.5 Fe ...

African Journals Online (AJOL)

Ni0.5M0.5Fe2O4 (M = Co, Cu) ferrite nanoparticles were synthesized using citrate precursor method. The citrate precursor was annealed at temperatures 400oC, 450oC, 500oC and 550oC. The annealed powders were characterized using X-ray diffractometer (XRD) and vibrating sample magnetometer (VSM). Observed ...

Obtaining alcohol from wooden waste of industry using an electron beam accelerator

International Nuclear Information System (INIS)

Naranjo, Rodrigo; Vallejo, Luz

2004-01-01

The present study refers to the application of a pre-treatment with electron beams to wooden powder to increase the cellulose conversion percentage in sugars during the acid hydrolysis processing and then getting alcohol by fermentation. The physical and chemical characterization of wooden powder was carried out, getting 66.39% cellulose, 3.1% wax and grease, 23.45% lignin, 6.18% pentosanes, 10.18% humidity, 0.89% ashes and the diameter of average particle equal to 11.56 mm. To irradiate wooden waste, an electron beam accelerator ELU 6U was used as a ionizing radiation source. It is installed in the Escuela Politecnica Nacional in Quito, Ecuador. Fermentation tests of hydrolyzed of irradiated wooden powder were done to determine the production of ethylic alcohol. The efficiency was 160 liters of ethanol to 100% from one ton of wooden waste, 66,4% cellulose. (The author)

Oxygen tracer diffusion and surface exchange kinetics in Ba0.5Sr0.5Co0.8Fe0.2O3-δ

NARCIS (Netherlands)

Berenov, A.; Atkinson, A.; Kilner, J.; Ananyev, M.; Eremin, V.; Porotnikova, N.; Farlenkov, A.; Kurumchin, E.; Bouwmeester, Henricus J.M.; Bucher, E.; Sitte, W.

2014-01-01

The oxygen tracer diffusion coefficient, Db⁎, and the oxygen tracer surface exchange coefficient, k, were measured in Ba0.5Sr0.5Co0.8Fe0.2O3 − δ (BSCF5582) over the temperature range of 310–800 °C and the oxygen partial pressure range of 1.3 × 10−3–0.21 bar. Several measurement techniques were used:

Semiconductor Ceramic Mn0.5Fe1.5O3-Fe2O3 from Natural Minerals as Ethanol Gas Sensors

Science.gov (United States)

Aliah, H.; Syarif, D. G.; Iman, R. N.; Sawitri, A.; Sanjaya WS, M.; Nurul Subkhi, M.; Pitriana, P.

2018-05-01

In this research, Mn and Fe-based ceramic gas sensing were fabricated and characterized. This research used natural mineral which is widely available in Indonesia and intended to observe the characteristics of Mn and Fe-based semiconducting material. Fabricating process of the thick films started by synthesizing the ceramic powder of Fe(OH)3 and Mn oxide material using the precipitation method. The deposition from precipitation method previously was calcined at a temperature of 800 °C to produce nanoparticle powder. Nanoparticle powder that contains Mn and Fe oxide was mixed with an organic vehicle (OV) to produce a paste. Then, the paste was layered on the alumina substrate by using the screen printing method. XRD method was utilized to characterize the thick film crystal structure that has been produced. XRD spectra showed that the ceramic layer was formed from the solid Mn0.5Fe1.5O3 (bixbyite) and Fe2O3. In addition, the electrical properties (resistance) examination was held in the room that contains air and ethanol to determine the sensor sensitivity of ethanol gas. The sensor resistance decreases as the ethanol gas was added, showing that the sensor was sensitive to ethanol gas and an n-type semiconductor. Gas sensor exhibit sensitive characterization of ethanol gas on the concentration of (100 to 300) ppm at a temperature of (150 to 200) °C. This showed that the Mn0.5Fe1.5O3-Fe2O3 ceramic semiconductor could be utilized as the ethanol gas detector.

Structural and electrical properties of La{sub 0.5}Ca{sub 0.5}Mn{sub 0.95}Fe{sub 0.05}O{sub 3+{delta}} perovskite

Energy Technology Data Exchange (ETDEWEB)

Mohamed, E.A., E-mail: emanattamohammed@yahoo.com [Department of Physics, Faculty of Science (Girl' s Branch), Al Azhar University, Nasr City, Cairo (Egypt)

2012-12-05

Highlights: Black-Right-Pointing-Pointer La{sub 0.5}Ca{sub 0.5}Mn{sub 0.95}Fe{sub 0.05}O{sub 3+{delta}} synthesis has been achieved by co-precipitation process. Black-Right-Pointing-Pointer Moessbauer results show an evidence for the local distortion of Mn(Fe)O{sub 6} octahedron. Black-Right-Pointing-Pointer Metal-Semiconductor transition temperature (T{sub p}) is observed. - Abstract: La{sub 0.5}Ca{sub 0.5}Mn{sub 0.95}Fe{sub 0.05}O{sub 3+{delta}} was synthesized by co-precipitation method. The structure refinement by using the Rietveld method indicates that the sample was single phase with the presence of small impurities (Mn{sub 3}O{sub 4}) and crystallizes in an orthorhombic (Pbmn) structure. The room temperature (RT) Moessbauer spectrum shows clear evidence of the local structural distortion of the Mn(Fe)O{sub 6} octahedron on the basis of non-zero nuclear quadrupole interactions for high-spin Fe{sup 3+} ions. The Jahn-Teller coupling strength (E{sub JT}) was estimated from the Moessbauer results. Metal-Semiconductor transition temperature (T{sub p}) is observed at 80 K. At high temperature (T{sub P} < T < {theta}{sub D}/2) conductivity data satisfy the variable range hopping (VRH) model. For T > {theta}{sub D}/2 the small polaron hopping model is more appropriate than the VRH model.

Structural and morphological study of Zn0.9Mn0.05Fe0.05O synthesized by sol-gel wet chemical precipitation route

Science.gov (United States)

Jain, S. K.; Dolia, S. N.; Choudhary, B. L.; Prashant, B. L.

2018-04-01

Transition metal substituted Zinc oxide (ZnO) has drawn a great deal of attention due to its excellent properties. Zn0.9Mn0.05Fe0.05O sample synthesized was by Sol-gel wet chemical precipitation route at temperature 350°C. The crystallinity and the structure of Zn0.9Mn0.05Fe0.05O was determined by X-ray diffraction by Cu-Kα radiations operated at 40kV and 35mA in the range of 20° to 80°. The pattern gets indexed in wurtzite (hexagonal) structure with lattice constants a=b=3.2525Å and c=5.2071Å and approves the single phase material with no impurity. The values of particle size assessed by Debye Scherer’s (DS) formula lie in the range of 13nm to 33nm indicating the nano-crystalline nature of the sample. The morphological analysis of the sample was performed by Scanning electron microscopy (SEM) and Transmission electron microscopy (TEM) measurements. The observed size of Zn0.9Mn0.05Fe0.05O nanoparticles by TEM micrograph exhibits the similar trend with the size calculated by Debye-Scherer formula. TEM image show the irregular shape of the nanoparticles and particle size lies in the range of 10-35nm. Similar to SEM image, the slight agglomeration of the nanoparticles have been observed from TEM.

A (Nd, Zr(Fe, Co11.5Ti0.5Nx compound as a permanent magnet material

Directory of Open Access Journals (Sweden)

S. Suzuki

2014-11-01

Full Text Available We studied NdFe11TiNx compounds as permanent magnet materials. The (Nd0.7,Zr0.3(Fe0.75Co0.2511.5Ti0.5N0.52 powder that contained a limited amount of the α-(Fe, Co phase shows fairly good magnetic properties, such as a saturation polarization (Js of 1.68 T and an anisotropic field (Ha of 2.88 (Law of approach to saturation – 4.0 MA/m (Intersection of magnetization curves. Both properties are comparable to those of the Nd2Fe14B phase.

Room temperature ferromagnetism in Th{sub 1-x}Fe{sub x}O{sub 2-{delta}} (x = 0.0, 0.05, 0.10, 0.15, 0.20 and 0.25) nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Jayakumar, O.D. [Chemistry Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Gopalakrishnan, I.K. [Chemistry Division, Bhabha Atomic Research Centre, Mumbai 400085 (India)], E-mail: ikgopal@barc.gov.in; Vinu, A. [Nano-Ionics Materials Group, Fuel Cell Materials Center, National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044 (Japan); Asthana, A. [Advanced Electron Microscopy Group, National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044 (Japan); Tyagi, A.K. [Chemistry Division, Bhabha Atomic Research Centre, Mumbai 400085 (India)

2008-08-11

Nanocrystalline (Th{sub 1-x}Fe{sub x})O{sub 2-{delta}} particles with different Fe concentrations (x = 0.0, 0.05, 0.10, 0.15, 0.20 and 0.25) have been prepared by a gel combustion method. Rietveld refinement analyses of X-ray diffraction data revealed the formation of an impurity free cubic type Th{sub 1-x}Fe{sub x}O{sub 2-{delta}} structure up to x = 0.20. This observation is further confirmed from the detailed studies conducted on 10 at.% Fe doped ThO{sub 2} using high-resolution transmission electron microscopy (HRTEM) imaging and indexing of the selected-area electron diffraction (SAED) patterns. DC magnetization studies as a function field indicate that they are ferromagnetic with Curie temperature (T{sub c}) well above room temperature.

Effect of O- and Mn-doping on superconductivity in FeTe{sub 0.5}Se{sub 0.5} superconductor

Energy Technology Data Exchange (ETDEWEB)

Thakur, Gohil S.; Haque, Zeba; Ganguli, Ashok K. [Department of Chemistry, Indian Institute of Technology, New Delhi (India); Neha, Prakriti; Patnaik, Satyabrata [School of Physical Science, Jawaharlal Nehru University, New Delhi (India); Gupta, Laxmi C. [Department of Chemistry, Indian Institute of Technology, New Delhi (India); Visiting project scientist at the:Solid State and Nanomaterials Research Laboratory, Department of Chemistry, IIT Delhi (India)

2014-05-15

The effect of oxygen substitution at the selenium site and manganese substitution at the iron site in FeTe{sub 0.5}Se{sub 0.5} superconductor was investigated. It was found that upon partial O substitution, T{sub c} marginally decreases as seen in both resistivity and magnetization experiments. T{sub c} decreases even by a small amount of oxygen concentration (as low as 1 %). This observation is in contrast against an earlier work on Fe(Te/Se) samples,1 wherein T{sub c} as well as superconducting volume fraction were reported to increase in the samples annealed in air. Mn-doping leads to a decrease in T{sub c} in FeTe{sub 0.5}Se{sub 0.5}, which one would expect considering pair-breaking due to Mn{sup 2+}-ions. (Copyright copyright 2014 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Wooden houses: energy savings in construction

International Nuclear Information System (INIS)

Gonthier, P.; Guillard, J.

1983-01-01

There is a renewed interest in wooden houses in France, and stress is rightly being put on their thermal insulation properties and the low recurrent costs of heating. On the other hand, it is less often realized that there are energy savings that result from the low energy-cost of producing and working with wood and wood-based products. On the basis of analyses and calculations made by one of us in the course of his studies at the E.N.G.R.E.F. (Forestry option), a comparison is made of the quantities of wood products used in various kinds of wooden houses. For each 100 m 2 of living space there are used 11-17 m 3 of sawn timber (some hardwoods but mainly softwoods), 1,4-3,6 m 3 of plywood and 2-6,5 m 3 of particleboard. This corresponds to a consumption of round-wood of 24-34,5 m 3 of saw logs and 3,5-9,8 m 3 of chip-wood and pulp-wood, i.e. 0,3-0,45 m 3 round-wood equivalent per square metre. With the help of American eco-energy data (the only available source), numerical values have been obtained for the energy consumed from harvesting the trees to building the houses. For 100 m 2 of living space in wooden houses, the expenditure of energy is 1,40-2,40 t oil equivalent, according to the type of house. This is 2,5-4 times less than for houses of steel and cement, of comparable cost and comfort. If it is still needed, this tentative eco-energy analysis supplies one more argument in favour of wooden housing. (authors)

A television in the bedroom is associated with higher weekday screen time among youth with attention deficit hyperactivity disorder (ADD/ADHD)

OpenAIRE

Lo, Charmaine B.; Waring, Molly E.; Pagoto, Sherry L.; Lemon, Stephenie C.

2015-01-01

Objective: A TV in the bedroom has been associated with screen time in youth. Youth with attention deficit hyperactivity disorder (ADD/ADHD) have higher rates of screen time, but associations with bedroom TVs are unknown in this population. We examined the association of having a bedroom TV with screen time among youth with ADD/ADHD. Methods: Data were from the 2007 National Survey of Children's Health. Youth 6–17 years whose parent/guardian reported a physician's diagnosis of ADD/ADHD (n ...

Determination of the 54Fe(n, 2n)53gFe and 54Fe(n, 2n)53mFe cross sections averaged over a 235U fission neutron spectrum

International Nuclear Information System (INIS)

Ribeiro Guevara, S.; Arribere, M.; Kestelman, A.J.

2002-01-01

The reaction cross sections averaged over a 235 U fission neutron spectrum have been measured for the 54 Fe(n, 2n) 53g Fe and 54 Fe(n, 2n) 53m Fe threshold reactions. The values found are, respectively: (1.14 ± 0.13) μb, and (0.52 ± 0.16) μb. The measured cross sections are referred to the (111± 3) mb standard cross section of the 58 Ni(n, p) 58m+g Co reaction. The (81.7 ± 2.2) mb standard cross section value for the 54 Fe(n, p) 54 Mn reaction, was also used as a monitor to check the results obtained with the Ni standard, leading to an excellent agreement. (author)

Improved Radiography Of Wooden Parts

Science.gov (United States)

Berry, Maggie L.; Berry, Robert F., Jr.

1990-01-01

Technique developed to increase radiographic contrasts of inherent latent defects in wood. Involves introduction of radiopaque substance into defect site and subjecting site to penetrating radiation. Radiopaque penetrant used is commercially available fluorocarbon cleaning solvent, trichlorotrifluoroethane. Applicable in inspection of wooden aircraft components, fan and wind-turbine blades, marine parts, insulators, and other wooden components, assemblies, and structures.

57Fe Moessbauer and magnetization study of the Th7Fe3 and the hydride Th7Fe3H/sub n/

International Nuclear Information System (INIS)

Viccaro, P.J.; Shenoy, G.K.; Dunlap, B.D.; Westlake, D.G.; Malik, S.K.; Wallace, W.E.

1978-01-01

Th 7 Fe 3 is known to be a Pauli paramagnet and to undergo a superconducting transition at 1.86K. Its hydride Th 7 Fe 3 H/sub n/ is shown to possess magnetic ordering. The 57 Fe saturated hyperfine field in the hydride is estimated to be aproximately 20kG. A positive isomer shift of 0.30 +- 0.02 mm/s at 300 K relative to Th 7 Fe 3 would be consistent with an increase in d-like electrons on Fe. Preliminary magnetization results indicate a magnetic moment of about 0.5 μ/sub B/ for the hydride and a transition temperature near 300 K

Charge dynamics of 57Fe probe atoms in La2Li0.5Cu0.5O4

Science.gov (United States)

Presniakov, I. A.; Sobolev, A. V.; Rusakov, V. S.; Moskvin, A. S.; Baranov, A. V.

2018-06-01

The objective of this study is to characterize the electronic state and local surrounding of 57Fe Mössbauer probe atoms within iron-doped layered perovskite La2Li0.5Cu0.5O4 containing transition metal in unusual formal oxidation states "+3". An approach based on the qualitative energy diagrams analysis and the calculations within the cluster configuration interaction method have been developed. It was shown that a large amount of charge is transferred via Cu-O bonds from the O: 2p bands to the Cu: 3d orbitals and the ground state is dominated by the d9L configuration ("Cu2+-O-" state). The dominant d9L ground state for the (CuO6) sublattice induces in the environment of the 57Fe probe cations a charge transfer Fe3+ + O-(L) → Fe4+ + O2-, which transforms "Fe3+" into "Fe4+" state. The experimental spectra in the entire temperature range 77-300 K were described with the use of the stochastic two-level model based on the assumption of dynamic equilibrium between two Fe3+↔Fe4+ valence states related to the iron atom in the [Fe(1)O4]4- center. The relaxation frequencies and activation energies of the corresponding charge fluctuations were estimated based on Mössbauer data. The results are discussed assuming a temperature-induced change in the electronic state of the [CuO4]5- clusters in the layered perovskite.

Structural and Mössbauer spectroscopy characterization of bulk and nanostructured TiFe{sub 0.5} Ni{sub 0.5}/graphite compounds and their hydrides

Energy Technology Data Exchange (ETDEWEB)

Martínez, M. A. R., E-mail: fisicorodriguez@gmail.com; André-Filho, J.; Félix, L. L.; Coaquira, J. A. H.; Garg, V. K.; Oliveira, A. C. [Universidade de Brasília, Instituto de Física, Núcleo de Física Aplicada (Brazil); Mestnik-Filho, J. [Instituto de Pesquisas energéticas e Nucleares, IPEN-CNEN/SP (Brazil)

2015-06-15

The structural and hyperfine properties of bulk TiFe{sub 0.5}Ni{sub 0.5} intermetallic and ball-milled TiFe{sub 0.5}Ni{sub 0.5}/graphite compounds and their hydrides have been studied. The bulk and nanostructured TiFe{sub 0.5}Ni{sub 0.5} compounds crystallize in the cubic crystal structure of CsCl (B2). After hydrogenation, the formation of hydrogen-poor phase (∝-phase) and hydride phase (β-phase) have been determined for the bulk compound. However, the formation of the ∝-phase and the hydrogen-richest phase (γ-phase) and other secondary phases have been determined for the ball-milled TiFe{sub 0.5}Ni{sub 0.5}/graphite sample. It has been determined that the ball-milled TiFe{sub 0.5}Ni{sub 0.5}/graphite sample presents a large amount of the γ-phase which indicates that the presence of graphite nearby nanostructured intermetallic grains enhances the absorption of hydrogen. Mossbauer results are consistent with the structural results. Meanwhile, no significant changes in the isomer shift (IS) value has been determined for the α-phase with respect to the intermetallic compound, a strong increase in the IS value has been determined for the β- and γ-phases with respect to the ∝-phase. That increase indicates a decrease of the s-electron density at the Fe nuclei due to the charge transfer from the metal to the nearby hydrogen atoms.

Grain boundary defect compensation in Ti-doped BaFe{sub 0.5}Nb{sub 0.5}O{sub 3} ceramics

Energy Technology Data Exchange (ETDEWEB)

Sun, Xiaojun; Deng, Jianming; Liu, Saisai; Yan, Tianxiang; Fang, Liang; Liu, Laijun [Guilin University of Technology, Key Laboratory of Nonferrous Materials and New Processing Technology, Ministry of Education, College of Materials Science and Engineering, Guangxi Universities Key Laboratory of Non-ferrous Metal Oxide Electronic Functional Materials and Devices, Guilin (China); Peng, Biaolin [Guangxi University, School of Physical Science and Technology and Guangxi Key Laboratory for Relativistic Astrophysics, Nanning (China); Jia, Wenhao [Shanghai Getong Enterprise Co., Ltd., Shanghai (China); Mei, Zaoming [Henan LiHeng Building Materials Co., Ltd., Zhengzhou (China); Su, Hongbo [Henan Province Product Quality Supervision and Inspection Center, Zhengzhou (China)

2016-09-15

Giant dielectric ceramics Ba(Nb{sub 0.5}Fe{sub 0.5-x}Ti{sub x})O{sub 3} (BNFT) have been fabricated by a conventional solid-state reaction. According to X-ray diffraction analysis, the crystal structure of these ceramics can be described by the cubic centrosymmetric with Pm-3m space group. The real part (ε') of dielectric permittivity and dielectric loss (tan δ) of the BNFT ceramics was measured in a frequency range from 40 Hz to 100 MHz at room temperature. The (ε') of all these samples displays a high value (∝6500) and a small frequency-dependence from 1 kHz to 1 MHz. We have established a link between conductivity activation energy and defect compensation at grain boundaries. The Ti{sup 4+}-doped Ba(Nb{sub 0.5}Fe{sub 0.5})O{sub 3} as a donor makes a great influence on the grain boundary behavior, which restricts the migration of oxygen vacancy and depresses dielectric loss factor for Ba(Nb{sub 0.5}Fe{sub 0.5})O{sub 3} ceramics. (orig.)

Charge transfer effects on the Fermi surface of Ba0.5K 0.5Fe2As2

KAUST Repository

Nazir, Safdar

2011-01-31

Ab-initio calculations within density functional theory are performed to obtain a more systematic understanding of the electronic structure of iron pnictides. As a prototypical compound we study Ba0.5K 0.5Fe2As2 and analyze the changes of its electronic structure when the interaction between the Fe2As 2 layers and their surrounding is modified. We find strong effects on the density of states near the Fermi energy as well as the Fermi surface. The role of the electron donor atoms in iron pnictides thus cannot be understood in a rigid band picture. Instead, the bonding within the Fe2As 2 layers reacts to a modified charge transfer from the donor atoms by adapting the intra-layer Fe-As hybridization and charge transfer in order to maintain an As3- valence state. © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Charge transfer effects on the Fermi surface of Ba0.5K 0.5Fe2As2

KAUST Repository

Nazir, Safdar; Zhu, Zhiyong; Schwingenschlö gl, Udo

2011-01-01

Ab-initio calculations within density functional theory are performed to obtain a more systematic understanding of the electronic structure of iron pnictides. As a prototypical compound we study Ba0.5K 0.5Fe2As2 and analyze the changes of its electronic structure when the interaction between the Fe2As 2 layers and their surrounding is modified. We find strong effects on the density of states near the Fermi energy as well as the Fermi surface. The role of the electron donor atoms in iron pnictides thus cannot be understood in a rigid band picture. Instead, the bonding within the Fe2As 2 layers reacts to a modified charge transfer from the donor atoms by adapting the intra-layer Fe-As hybridization and charge transfer in order to maintain an As3- valence state. © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Intraorbital wooden and bamboo foreign bodies: CT

International Nuclear Information System (INIS)

Uchino, A.; Kato, A.; Takase, Y.; Kudo, S.

1997-01-01

We describe the CT findings of intraorbital wooden and bamboo foreign bodies in the acute, subacute, and chronic stages. We examined four patients using CT a total of seven times. The CT findings were reviewed. There were three dry wooden foreign bodies. CT within a day of the accident demonstrated wooden foreign bodies as low density relative to surrounding orbital fat, while CT 8-29 days after the accident showed them as denser than the extraocular muscles. In the acute stage, dry wooden foreign bodies mimic air bubbles. Wooden foreign bodies in the subacute and chronic stages should be included in the differential diagnosis of intraorbital lesions of soft tissue density or above on CT of traumatised orbits. There was one dry bamboo foreign body. Within a day of the accident it was recognised as linear lesion isodense with fat. Therefore, such foreign bodies may be missed on CT when located in the orbital fat. (orig.)

Insight into cation disorder of Li{sub 2}Fe{sub 0.5}Mn{sub 0.5}SiO{sub 4}

Energy Technology Data Exchange (ETDEWEB)

Bini, Marcella [Dept. of Chemistry, University of Pavia, viale Taramelli 16, Pavia 27100 (Italy); Ferrari, Stefania, E-mail: stefania.ferrari@unipv.it [Dept. of Chemistry, University of Pavia, viale Taramelli 16, Pavia 27100 (Italy); Capsoni, Doretta; Spreafico, Clelia; Tealdi, Cristina; Mustarelli, Piercarlo [Dept. of Chemistry, University of Pavia, viale Taramelli 16, Pavia 27100 (Italy)

2013-04-15

Transition metal lithium orthosilicates are promising cathode materials for lithium-ion batteries. Here we report a combined experimental (in situ X-ray diffraction) and computational (static lattice and molecular dynamics) study of the thermal behavior of the Li{sub 2}Fe{sub 0.5}Mn{sub 0.5}SiO{sub 4} orthosilicate from room temperature to 950 °C. Our X-ray results showed that Pmnb polymorph is the most stable all over the explored temperature range. A significant cation disorder up to 80%, based on the anti-site defect, was found. The defect concentration depends on the synthesis route and temperature, and is completely reversible after the thermal treatments. Moreover, a careful analysis of the impurity phases allowed us to identify Li{sub 2}SiO{sub 3}, Fe{sub 3}O{sub 4} and Li{sub 3}Fe{sub 5}O{sub 8}, the last one never reported before. The minimization of defects by opportunely tuning the synthetic parameters would be of great importance in view of potential applications of these materials in lithium batteries. - Graphical abstract: A combined experimental in situ X-ray diffraction and computational study of the thermal behavior of the Li{sub 2}Fe{sub 0.5}Mn{sub 0.5}SiO{sub 4} is reported herein. The anti-site defect does justify the diffraction patterns changes with temperature. Highlights: ► Study of the thermal behavior of Li{sub 2}Fe{sub 0.5}Mn{sub 0.5}SiO{sub 4}. ► The anti-site defect does justify the diffraction patterns changes with temperature. ► The Pmnb polymorph is stable in the investigated temperaturerange.

AC conductivity, magnetic and shielding effectiveness studies on polyaniline embedded Co0.5Mn0.5Fe2O4 nanoparticles for electromagnetic interference suppression

Science.gov (United States)

Gurusiddesh, M.; Madhu, B. J.; Shankaramurthy, G. J.

2018-05-01

Electrically conducting Polyaniline (PANI)/Co0.5Mn0.5Fe2O4 nanocomposites are synthesized by in situ polymerization of aniline monomer in the presence of Co0.5Mn0.5Fe2O4 nanoparticles. Structural studies on the synthesized samples have been carried out using X-ray diffraction technique, Field emission scanning electron microscopy and Energy dispersive X-ray spectroscopy. Frequency dependent ac conductivity studies on the prepared samples revealed that conductivity of the composite is high compared to Co0.5Mn0.5Fe2O4 nanoparticles. Further, both the samples exhibited hysteresis behavior under the applied magnetic field. Electromagnetic interference (EMI) shielding effectiveness of both the samples decreases with increase in the applied frequency in the studied frequency range. Maximum shielding effectiveness (SE) of 31.49 dB and 62.84 dB were obtained for Co0.5Mn0.5Fe2O4 nanoparticles and PANI/Co0.5Mn0.5Fe2O4 nanocomposites respectively in the studied frequency range. Observed higher EMI shielding in the composites was attributed to its high electrical conductivity.

THE BEHAVIOURAL REACTION OF WEANERS TO HANGING TOYS: WOODEN BALL AND AROMATIZED WOODEN BALL – WAY TO REDUCE AGGRESSION AFTER MIXING

Directory of Open Access Journals (Sweden)

Jacek NOWICKI

2008-05-01

Full Text Available The behaviour of weaners after mixing housed in pens equipped with hanging wooden ball, aromatized with vanilla fluid hanging wooden ball and without enrichment was evaluated. It was found that both enrichments reduced aggression, however the most interesting for weaners was the aromatized wooden ball.

Facile synthesis of Fe4N/Fe2O3/Fe/porous N-doped carbon nanosheet as high-performance anode for lithium-ion batteries

Science.gov (United States)

Zhang, Dan; Li, Guangshe; Yu, Meijie; Fan, Jianming; Li, Baoyun; Li, Liping

2018-04-01

Iron nitrides are considered as highly promising anode materials for lithium-ion batteries because of their nontoxicity, high abundance, low cost, and higher electrical conductivity. Unfortunately, their limited synthesis routes are available and practical application is still hindered by their fast capacity decay. Herein, a facile and green route is developed to synthesize Fe4N/Fe2O3/Fe/porous N-doped carbon nanosheet composite. The size of Fe4N/Fe2O3/Fe particles is small (10-40 nm) and they are confined in porous N-doped carbon nanosheet. These features are conducive to accommodate volume change well, shorten the diffusion distance and further elevate electrical conductivity. When tested as anode material for lithium-ion batteries, a high discharge capacity of 554 mA h g-1 after 100 cycles at 100 mA g-1 and 389 mA h g-1 after 300 cycles at 1000 mA g-1 are retained. Even at 2000 mA g-1, a high capacity of 330 mA h g-1 can be achieved, demonstrating superior cycling stability and rate performance. New prospects will be brought by this work for the synthesis and the potential application of iron nitrides materials as an anode for LIBs.

Predictors of indoor fine particulate matter in infants' bedrooms in Denmark.

Science.gov (United States)

Raaschou-Nielsen, Ole; Sørensen, Mette; Hertel, Ole; Chawes, Bo L K; Vissing, Nadja; Bønnelykke, Klaus; Bisgaard, Hans

2011-01-01

Particulate matter (PM) in ambient air is responsible for adverse health effects in adults and children. Relatively little is known about the concentrations, sources and health effects of PM in indoor air. To identify sources of fine PM in infants' bedrooms. We conducted 1122 measurements of fine PM (PM(2.5) and black smoke) in the bedrooms of 389 infants and registered indoor activities and characteristics of the house. We used mixed models to identify and quantify associations between predictors and concentrations. The concentration of PM(2.5) was 2.8 times (95% confidence interval [CI], 1.4-5.5 times) higher in houses where people smoked; the concentration increased by 19% (95% CI, 15-23%) per doubling of the amount of tobacco smoked and decreased by 16% (95% CI, 9-27%) per 5-m increase in the distance between the smoking area and the infant's bedroom. Frying without a range hood was associated with a 32% (95% CI, 12-54%) higher PM(2.5) concentration per time per day, whereas frying with use of a range hood did not increase the concentration in the infant's bedroom. Use of a fireplace, stove, candles or vacuum-cleaner, interior rebuilding or renovation, local traffic, inner city residence and cold season increased the fine PM concentration. Open windows decreased the PM(2.5) concentration in homes with smokers but increased the concentration in non-smoking homes. We identified several sources of fine PM in infants' bedrooms. The concentrations can be reduced by use of a range hood for frying, by not using candles, a fireplace or a stove, by increasing the distance between the bedroom and the smoking area and by opening windows in houses of smokers. Smoking is a strong predictor of fine PM in infants' bedrooms and should be avoided. Copyright © 2010 Elsevier Inc. All rights reserved.

Statistical modeling of the reactions Fe(+) + N2O → FeO(+) + N2 and FeO(+) + CO → Fe(+) + CO2.

Science.gov (United States)

Ushakov, Vladimir G; Troe, Jürgen; Johnson, Ryan S; Guo, Hua; Ard, Shaun G; Melko, Joshua J; Shuman, Nicholas S; Viggiano, Albert A

2015-08-14

The rates of the reactions Fe(+) + N2O → FeO(+) + N2 and FeO(+) + CO → Fe(+) + CO2 are modeled by statistical rate theory accounting for energy- and angular momentum-specific rate constants for formation of the primary and secondary cationic adducts and their backward and forward reactions. The reactions are both suggested to proceed on sextet and quartet potential energy surfaces with efficient, but probably not complete, equilibration by spin-inversion of the populations of the sextet and quartet adducts. The influence of spin-inversion on the overall reaction rate is investigated. The differences of the two reaction rates mostly are due to different numbers of entrance states (atom + linear rotor or linear rotor + linear rotor, respectively). The reaction Fe(+) + N2O was studied either with (6)Fe(+) or with (4)Fe(+) reactants. Differences in the rate constants of (6)Fe(+) and (4)Fe(+) reacting with N2O are attributed to different contributions from electronically excited potential energy surfaces, such as they originate from the open-electronic shell reactants.

Ferrites Ni0,5Zn0,5Fe2O4 doped with samarium: structural analysis, morphological and electromagnetic

International Nuclear Information System (INIS)

Costa, A.C.F.M.; Diniz, A.P.; Viana, K.M.S.; Cornejo, D.R.; Kiminami, R.H.G.A.

2010-01-01

This paper proposes to investigate the sintering at 1200 deg C/2h of Ni 0.5 Zn 0.5 Fe 2-x Sm x O 4 ferrite doped with 0.05; 0.075 e 0.1 mol of Sm synthesized by combustion reaction to evaluate the performance materials as absorbers of electromagnetic radiation. The influence of the concentration of samarium on the structure, morphology and electromagnetic properties of ferrites was studied. The resulting samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), magnetic measurements and reflectivity measurements in the frequency range between 8-12 GHz. The results showed that increasing the concentration of samarium caused a decrease in particle size of the samples, encouraging, therefore, to obtain materials with better values of magnetization and reflectivity, allowing for use as absorbers in narrow-band frequency between 9-10 GHz. (author)

Nickel-zinc ferrite/permalloy (Ni0.5Zn0.5Fe2O4/Ni-Fe soft magnetic nanocomposites fabricated by electro-infiltration

Directory of Open Access Journals (Sweden)

Xiao Wen

2016-05-01

Full Text Available Magnetically soft NiZn ferrite (Ni0.5Zn0.5Fe2O4 nanoparticles are embedded within a permalloy (Ni-Fe matrix via an electro-infiltration process as thin films intended for use as on-chip inductor cores in the MHz frequency regime. A layer of NiZn ferrite nanoparticles is first deposited, and then permalloy is electroplated through the voids to encapsulate the particles and form three-dimensional ferrite/alloy nanocomposites. The composites are estimated to contain 37% ferrite by volume and exhibit a relative permeability of ∼320, a saturation of ∼1.15 T, and an operational bandwidth of 93 MHz. Compared to a permalloy thin film of similar thickness, the nanocomposite exhibits 39% higher electrical resistivity and 50% higher bandwidth.

Unraveling the magnetic properties of BiFe{sub 0.5}Cr{sub 0.5}O{sub 3} thin films

Energy Technology Data Exchange (ETDEWEB)

Vinai, G.; Petrov, A. Yu.; Panaccione, G.; Torelli, P. [Laboratorio TASC, IOM-CNR, S.S. 14 km 163.5, Basovizza, I-34149 Trieste (Italy); Khare, A. [CNR-SPIN Napoli and Dipartimento di Fisica, Università di Napoli “Federico II,” I-80126 Napoli (Italy); Department of Physics, Sungkyunkwan University, Suwon 440 746 (Korea, Republic of); Rana, D. S. [Department of Physics, Indian Institute of Science Education and Research Bhopal, Govindpura, Bhopal 462023 (India); Di Gennaro, E.; Scotti di Uccio, U.; Miletto Granozio, F. [CNR-SPIN Napoli and Dipartimento di Fisica, Università di Napoli “Federico II,” I-80126 Napoli (Italy); Gobaut, B. [Sincrotrone Trieste S.C.p.A., S.S. 14 Km 163.5, Area Science Park, 34149 Trieste (Italy); Moroni, R. [CNR-SPIN, Corso Perrone 24, I-16152 Genova (Italy); Rossi, G. [Laboratorio TASC, IOM-CNR, S.S. 14 km 163.5, Basovizza, I-34149 Trieste (Italy); Department of Physics, Università degli Studi di Milano, via Celoria 16, I-20133 Milano (Italy)

2015-11-01

We investigate the structural, chemical, and magnetic properties on BiFe{sub 0.5}Cr{sub 0.5}O{sub 3} (BFCO) thin films grown on (001) (110) and (111) oriented SrTiO{sub 3} (STO) substrates by x-ray magnetic circular dichroism and x-ray diffraction. We show how highly pure BFCO films, differently from the theoretically expected ferrimagnetic behavior, present a very weak dichroic signal at Cr and Fe edges, with both moments aligned with the external field. Chemically sensitive hysteresis loops show no hysteretic behavior and no saturation up to 6.8 T. The linear responses are induced by the tilting of the Cr and Fe moments along the applied magnetic field.

Magnetic properties and magnetocaloric effect of MnFeP0.5Ge0.5-xSix compounds

International Nuclear Information System (INIS)

Song, L.; Wang, G.F.; Ou, Z.Q.; Haschaolu, O.; Tegus, O.; Brueck, E.; Buschow, K.H.J.

2009-01-01

We have studied the magnetic properties and magnetic-entropy changes of the MnFeP 0.5 Ge 0.5-x Si x compounds with x = 0.1, 0.2, 0.3, 0.4 and 0.45. X-ray diffraction shows that the compounds crystallize in the Fe 2 P-type hexagonal structure. The lattice parameter a and the Curie temperature decreases with increasing x. The maximal magnetic-entropy changes for x = 0.4 and 0.45 derived from the magnetization data are about 6.0 J/kg K and 5.8 J/kg K, respectively, for a field change from 0 to 1.5 T

Synthesis of single-phase L10-FeNi magnet powder by nitrogen insertion and topotactic extraction

OpenAIRE

Goto, Sho; Kura, Hiroaki; Watanabe, Eiji; Hayashi, Yasushi; Yanagihara, Hideto; Shimada, Yusuke; Mizuguchi, Masaki; Takanashi, Koki; Kita, Eiji

2017-01-01

Tetrataenite (L10-FeNi) is a promising candidate for use as a permanent magnet free of rare-earth elements because of its favorable properties. In this study, single-phase L10-FeNi powder with a high degree of order was synthesized through a new method, nitrogen insertion and topotactic extraction (NITE). In the method, FeNiN, which has the same ordered arrangement as L10-FeNi, is formed by nitriding A1-FeNi powder with ammonia gas. Subsequently, FeNiN is denitrided by topotactic reaction to ...

Deformations of temporary wooden supports used to reduce building deflections in mining areas

Science.gov (United States)

Gromysz, Krzysztof

2018-04-01

Temporary supports, consisting of a stack of wooden elements and a hydraulic jack, are used in the process of removing deflections in buildings with one to three aboveground floors in mining areas. During uneven raising, the supports are loaded monotonically, unloaded and loaded cyclically. Laboratory tests were designed for the supports. For the investigated range of loads of 0 to 400 kN, under a growing load, a linear relationship exists between a load and the change in the stack length, which signifies that the deformations of wooden elements and displacements related to their mutual interactions increase proportionally. A seemingly higher stack stiffness is seen at the beginning of the unloading process and for cyclical loads, meaning that in this phase of loading, the material deformation of the wooden elements and the jack is responsible for changing the jack length in this load phase, with a negligible presence of mutual displacements of wooden elements. The support, after being unloaded, returns to the initial position and its permanent deformations are not observed. The stiffness of a temporary support decreases as the height of the stack of wooden elements increases.

Deformations of temporary wooden supports used to reduce building deflections in mining areas

Directory of Open Access Journals (Sweden)

Gromysz Krzysztof

2018-01-01

Full Text Available Temporary supports, consisting of a stack of wooden elements and a hydraulic jack, are used in the process of removing deflections in buildings with one to three aboveground floors in mining areas. During uneven raising, the supports are loaded monotonically, unloaded and loaded cyclically. Laboratory tests were designed for the supports. For the investigated range of loads of 0 to 400 kN, under a growing load, a linear relationship exists between a load and the change in the stack length, which signifies that the deformations of wooden elements and displacements related to their mutual interactions increase proportionally. A seemingly higher stack stiffness is seen at the beginning of the unloading process and for cyclical loads, meaning that in this phase of loading, the material deformation of the wooden elements and the jack is responsible for changing the jack length in this load phase, with a negligible presence of mutual displacements of wooden elements. The support, after being unloaded, returns to the initial position and its permanent deformations are not observed. The stiffness of a temporary support decreases as the height of the stack of wooden elements increases.

Implications of white striping and wooden breast abnormalities on quality traits of raw and marinated chicken meat.

Science.gov (United States)

Mudalal, S; Lorenzi, M; Soglia, F; Cavani, C; Petracci, M

2015-04-01

One of the consequences of intense genetic selection for growth of poultry is the recent appearance of abnormalities in chicken breast muscles, such as white striping (characterised by superficial white striations) and wooden breast (characterised by pale and bulged areas with substantial hardness). The aim of this study was to evaluate the quality traits of chicken fillets affected by white striping and wooden breast abnormalities. In two replications, 192 fillets were divided into the following four classes: normal (n=48; absence of any visual defects), white striping (n=48, presence of white striations), wooden breast (n=48; diffusely presence of hardened areas) and white striping/wooden breast (n=48; fillets affected by both abnormalities). Morphology, raw meat texture and technological properties were assessed in both unprocessed (pH, colour, drip loss, cooking loss and cooked meat shear force) and marinated meat (marinade uptake, purge loss, cooking loss and cooked meat shear force). Fillets affected by white striping, wooden breast or both abnormalities exhibited higher breast weights compared with normal fillets (305.5, 298.7, 318.3 and 244.7 g, respectively; Pcooking losses than white-striped fillets for both unprocessed and marinated meats. On the other hand, white-striped fillets showed a moderate decline in marinade and cooking yield. Fillets affected by both abnormalities had the highest (Pcooked meat, drip loss, purge loss and cooked meat shear force were negligible or relatively low and of little practical importance. Thus, the presence of white striping and wooden breast abnormalities impair not only breast meat appearance but also the quality of both raw and marinated meats mainly by reducing water holding/binding abilities.

Permanent magnets prepared from Sm10.5Fe88.5Zr1.0Ny without homogenization

International Nuclear Information System (INIS)

Gebel, B.; Kubis, M.; Mueller, K.-H.

1997-01-01

In as-cast Sm 2 Fe 17 the high amount of α-Fe caused by a peritectic reaction can be considerably reduced by a small addition of about 1 at% Zr. X-ray diffraction showed that as-cast Sm 10.5 Fe 88.5 Zr 1.0 mainly consists of a phase with the Th 2 Zn 17 -type structure and SmFe 3 . Non-homogenized Sm 10.5 Fe 88.5 Zr 1.0 was milled and (i) annealed in vacuum or (ii) treated with a hydrogenation-disproportionation-desorp tion-recombination (HDDR) process. The annealed and subsequently nitrogenated powder is magnetically anisotropic and has a coercivity μ 0J H C up to 2.0 T and an energy product (BH) max up to 136 kJ/m 3 . HDDR-treated and nitrogenated powder is isotropic and exhibits values of μ 0J H C = 3.1 T and (BH) max 103 kJ/m 3 . Consequently, Sm 10.5 Fe 88.5 Zr 1.0 N y (y ∼ 16) permanent magnets with very good properties can be prepared without the time-consuming homogenization procedure. (orig.)

A mixed iron-manganese based pyrophosphate cathode, Na2Fe0.5Mn0.5P2O7, for rechargeable sodium ion batteries.

Science.gov (United States)

Shakoor, Rana A; Park, Chan Sun; Raja, Arsalan A; Shin, Jaeho; Kahraman, Ramazan

2016-02-07

The development of secondary batteries based on abundant and cheap elements is vital. Among various alternatives to conventional lithium-ion batteries, sodium-ion batteries (SIBs) are promising due to the abundant resources and low cost of sodium. While there are many challenges associated with the SIB system, cathode is an important factor in determining the electrochemical performance of this battery system. Accordingly, ongoing research in the field of SIBs is inclined towards the development of safe, cost effective cathode materials having improved performance. In particular, pyrophosphate cathodes have recently demonstrated decent electrochemical performance and thermal stability. Herein, we report the synthesis, electrochemical properties, and thermal behavior of a novel Na2Fe0.5Mn0.5P2O7 cathode for SIBs. The material was synthesized through a solid state process. The structural analysis reveals that the mixed substitution of manganese and iron has resulted in a triclinic crystal structure (P1[combining macron] space group). Galvanostatic charge/discharge measurements indicate that Na2Fe0.5Mn0.5P2O7 is electrochemically active with a reversible capacity of ∼80 mA h g(-1) at a C/20 rate with an average redox potential of 3.2 V. (vs. Na/Na(+)). It is noticed that 84% of initial capacity is preserved over 90 cycles showing promising cyclability. It is also noticed that the rate capability of Na2Fe0.5Mn0.5P2O7 is better than Na2MnP2O7. Ex situ and CV analyses indicate that Na2Fe0.5Mn0.5P2O7 undergoes a single phase reaction rather than a biphasic reaction due to different Na coordination environment and different Na site occupancy when compared to other pyrophosphate materials (Na2FeP2O7 and Na2MnP2O7). Thermogravimetric analysis (25-550 °C) confirms good thermal stability of Na2Fe0.5Mn0.5P2O7 with only 2% weight loss. Owing to promising electrochemical properties and decent thermal stability, Na2Fe0.5Mn0.5P2O7, can be an attractive cathode for SIBs.

Wooden houses in detail. Holzhaeuser im Detail

Energy Technology Data Exchange (ETDEWEB)

Ruske, W. (ed.)

1986-01-01

Under the serial title 'Planning and construction of wooden houses', WEKA will publish a number of books of which this is the first. Details of design and construction are presented, e.g.: Details of modern one-family houses; Fundamentals of design and hints for planning of wooden houses and compact wooden structures; Constructional ecology, wood protection, thermal insulation, sound insulation; Modular systems for domestic buildings; The 'bookshelf-type' house at the Berlin International Construction Exhibition (IBA); Experience with do-it-yourself systems. With 439 figs.

Phase transitions in Fe_0_._5Co_0_._5 (110) thin films

International Nuclear Information System (INIS)

Ramírez-Dámaso, G.; Castillo-Alvarado, F.L.; Rojas-Hernández, E.

2016-01-01

In this paper, we present calculations for two second-order phase transitions in (110) Fe_0_._5Co_0_._5 thin films with 11, 15, and 19 monoatomic layers. The lattice and magnetic transitions are based on thermodynamic equilibrium considerations of the magnetic alloy. The procedure proposed by Valenta and Sukiennicki was applied to calculate the composition x(i), the lattice order parameter t(i), and the magnetic order parameter σ(i) as a function of temperature T. We confirmed that both phase transitions, lattice and magnetic, are of the second order, in accordance with experimental results in the literature. The obtained behavior of these parameters indicates their inhomogeneity due to the boundary conditions on the surfaces of the thin film.

Modeling thermodynamics of Fe-N phases; characterisation of e-Fe2N1-z

DEFF Research Database (Denmark)

Pekelharing, M.I.; Böttger, A.; Somers, Marcel A.J.

1999-01-01

In order to arrive at modeling the thermodynamics of Fe-N phases, including long-range (LRO) and short-range ordering (SRO) of the N atoms, it is important to understand the role of N interstitially dissolved in an Fe-host lattice. The crystal structure of -Fe2N1-z consists of an h.c.p. iron...... sublattice and a hexagonal nitrogen sublattice formed by octahedral interstices of the Fe sublattice [1]. Two ground-state structures have been proposed for the ordered arrangement of the N atoms on their own sublattice [1], which were shown to be thermodynamically favourable [2]: configuration A for Fe2N1...... investigated with X-ray diffraction (XRD) and Mössbauer spectroscopy. A thermodynamic model accounting for the two configurations of LRO of the N atoms [2,3] was fitted to the N-absorption isotherm at 723 K and resulted in the occupancies of the sites of the nitrogen sublattice. A miscibility gap between...

Cobalt-free perovskite Pr_0_._5Sr_0_._5Fe_1_−_xCu_xO_3_−_δ (PSFC) as a cathode material for intermediate temperature solid oxide fuel cells

International Nuclear Information System (INIS)

Moura, Caroline G.; Grilo, João Paulo de F.; Macedo, Daniel A.; Cesário, Moisés R.; Fagg, Duncan Paul; Nascimento, Rubens M.

2016-01-01

PSFC (Pr_0_._5Sr_0_._5Fe_1_−_xCu_xO_3_−_δ) is a new perovskite-type oxide that has gained considerable attention as cathode material for intermediate temperature solid oxide fuel cells (IT-SOFCs), due to its high mixed ionic-electronic conductivity below 800 °C. In this work, PSFC (Pr_0_._5Sr_0_._5Fe_1_−_xCu_xO_3_−_δ, x = 0.2 and 0.4) powders were synthesized by the citrate method and structurally characterized by X-ray diffractometry. Screen-printed cathodes were sintered at 1050 °C and electrochemically characterized by impedance spectroscopy at 600–800 °C in pure oxygen. The area specific resistances (ASR) of the Pr_0_._5Sr_0_._5Fe_0_._8Cu_0_._2O_3_−_δ material are shown to be competitive with typical values reported for cobalt-based cathodes in the measured temperature range, while, importantly, offering a significantly lower activation energy, 0.62 eV. The thermal expansion coefficients of these Co-free cathodes are in the range of 13–15 × 10"−"6 °C"−"1, in a temperature range 200–650 °C, demonstrating a good thermal compatibility with gadolinia doped ceria (CGO) electrolytes. - Highlights: • Cobalt-free Pr_0_._5Sr_0_._5Fe_1_−_xCu_xO_3_−_δ (PSFC) cathodes successfully prepared by the citrate method. • PSFC cathodes are thermally compatible with CGO electrolytes. • Pr_0_._5Sr_0_._5Fe_0_._8Cu_0_._2O_3_−_δ presents competitive area specific resistances of low activation energy, 0.62 eV.

Efecto del BiFeO3 en las propiedades del sistema ferroeléctrico libre de plomo K0.5Na0.5NbO3

Directory of Open Access Journals (Sweden)

Pinza, Billy N.

2014-10-01

Full Text Available In order to obtain a multiferroic material, powders and ceramic pieces, of the lead-free ferroelectric (1-x-x K0.5Na0.5NbO3 (Bi0.8La0.2FeO3 (KNN-BLFO (x = 0.005, 0.010, 0.015, 0.020, 0.025 system were prepared using the combustion reaction method. For all the studied perovskite phase, stoichiometries feature KNN was obtained. Using characterisation techniques, it was determined that the BLFO is incorporated in the crystal structure of KNN without modifying present a phase transition. Moreover, It was also proved that the addition of the BLFO to KNN, alters the particle size of the obtained powders and generates magnetic behavior in this ferroelectric.En la búsqueda de un material multiferroico, se prepararon polvos y piezas cerámicas del sistema ferroeléctrico libre de plomo (1-xK0.5Na0.5NbO3-x(Bi0.8La0.2FeO3 (KNN-BLFO (x=0.005, 0.010, 0.015, 0.020, 0.025, mediante el método de reacción por combustión. Para todas las estequiometrias estudiadas se obtuvo la fase perovskita característica del KNN. Con las diferentes caracterizaciones se determinó que el BLFO se incorpora en la estructura cristalina del KNN modificándola sin que se presente una transición de fase. Se comprobó además que la adición del BLFO al KNN, altera el tamaño de partícula de los polvos obtenidos y genera comportamiento magnético en este ferroeléctrico.

Structural, dielectric and magnetic properties of (Pb{sub 1−x}Ca{sub x})(Fe{sub 0.5}Nb{sub 0.5})O{sub 3} solid solution ceramics

Energy Technology Data Exchange (ETDEWEB)

Puri, Maalti; Bahel, Shalini [Guru Nanak Dev University, Punjab (India); Raevski, I.P. [Southern Federal University, Rostov-on-Don (Russian Federation); Narang, Sukhleen Bindra [Guru Nanak Dev University, Punjab (India)

2016-06-01

Ceramic samples of (Pb{sub 1−x}Ca{sub x})(Fe{sub 0.5}Nb{sub 0.5})O{sub 3} with x=0.0, 0.20, 0.40, 0.45, 0.50, 0.55, 0.60 and 1.0 were fabricated by columbite precursor method. All the synthesized samples have a perovskite structure and unit cell volume decreases with increasing Ca content. The substitution of Ca for Pb has been found to have a pronounced effect on structural, dielectric and magnetic properties. Saturated magnetic loops were observed at room temperature for compositions with x≥0.40. The observed maximal magnetization at room temperature is rather small and varies non-monotonically with increasing Ca contents. It is supposed that room-temperature magnetic properties of (Pb{sub 1−x}Ca{sub x})(Fe{sub 0.5}Nb{sub 0.5})O{sub 3} ceramics might be due to the presence of ferromagnetic impurity, presumably PbFe{sub 12}O{sub 19} and/or CaFe{sub 12}O{sub 19}. - Highlights: • Ceramic samples have been synthesized using columbite precursor method. • The substitution of Ca for Pb has a pronounced effect on various properties. • Low losses at high frequencies make these ceramics suitable for microwave applications. • M–H loops at room temperature are reported first time.

Formulation of an OTTV for walls of bedroom in Thailand

International Nuclear Information System (INIS)

Tummu, Preecha; Chirarattananon, Surapong; Hien, Vu Duc; Chaiwiwatworakul, Pipat; Rakkwamsuk, Pattana

2017-01-01

Highlights: • High and increasing use of air-conditioning in household bedrooms. • Building envelope is the barrier against heat gain into air-conditioned bedroom. • The OTTV form of performance measure for bedroom wall is applicable. • Effects of solar radiation appear strongly in OTTV formulation. - Abstract: Air-conditioning has penetrated to a significant extent in urban households and is increasingly used in all areas in Thailand. Building envelope is the most significant component that affects energy performance of an air-conditioned building. This paper reports results of an attempt to formulate a measure of performance of building envelope enclosing space used under bedroom function. The overall thermal transfer value form of the measure that comprises a heat gain through opaque wall term, a solar radiation gain term, and a conduction heat gain through glazing term proves to apply well. The formulation is validated through the use of two simulation programs on two residential building models with significant variations of the envelope thermal parameters. The work is a part of an effort in an international research program to develop a scheme for rating energy and carbon performance of residential buildings.

Synthesis and characterization of Mn{sub 0.5}Zn{sub 0.5}Fe{sub 2}O{sub 4} and Fe{sub 3}O{sub 4} nanoparticle ferrofluids for thermo-electric conversion

Energy Technology Data Exchange (ETDEWEB)

Sansom, C.L., E-mail: c.l.sansom@cranfield.ac.uk [Cranfield University, Cranfield MK43 0AL (United Kingdom); Jones, P.; Dorey, R.A.; Beck, C.; Stanhope-Bosumpim, A. [Cranfield University, Cranfield MK43 0AL (United Kingdom); Peterson, J. [Peterson Dynamics Ltd., 9 Nant y Gamar Road, Craig y Don LL30 1YE (United Kingdom)

2013-06-15

Ferrofluids containing nanoparticles of Mn{sub 0.5}Zn{sub 0.5}Fe{sub 2}O{sub 4} (MZ5) and Fe{sub 3}O{sub 4} (magnetite) have been examined as potential thermal transport media and energy harvesting materials. The ferrofluids were synthesized by chemical co-precipitation and characterized by EDX to determine composition and by TEM to determine particle size and agglomeration. A range of particle coatings and carrier fluids were used to complete the fluid preparation. Commercially available ferrofluids were tested in custom built rigs to demonstrate both thermal pumping (for waste heat removal applications) and power induction (for power conversion and energy harvesting applications). The results indicate that simple ferrofluids possess the necessary properties to remove waste heat, either into thermal storage or for conversion to electrical power. - Highlights: ► The synthesis of nanoparticle ferrofluids based on Mn{sub 0.5}Zn{sub 0.5}Fe{sub 2}O{sub 4} and Fe{sub 3}O{sub 4} is reported. ► The thermal properties of the ferrofluids creates a novel pump with no moving parts. ► Thermal energy harvesting for conversion into electrical power is demonstrated.

Perpendicular magnetic anisotropy in Mo/Co2FeAl0.5Si0.5/MgO/Mo multilayers with optimal Mo buffer layer thickness

Science.gov (United States)

Saravanan, L.; Raja, M. Manivel; Prabhu, D.; Pandiyarasan, V.; Ikeda, H.; Therese, H. A.

2018-05-01

Perpendicular Magnetic Anisotropy (PMA) was realized in as-deposited Mo(10)/Co2FeAl0.5Si0.5(CFAS)(3)/MgO(0.5)/Mo multilayer stacks with large perpendicular magnetic anisotropy energy (Keff). PMA of this multilayer is found to be strongly dependent on the thickness of the individual CFAS (tCFAS), Mo (tMo) and MgO (tMgO) layers and annealing temperatures. The interactions at the Mo/CFAS/MgO interfaces are critical to induce PMA and are tuned by the interfacial oxidation. The major contribution to PMA is due to iron oxide at the CFAS/MgO interface. X-ray diffraction (XRD) and infrared spectroscopic (FT-IR) studies further ascertain this. However, an adequate oxidation of MgO and the formation of (0 2 4) and (0 1 8) planes of α-Fe2O3 at the optimal Mo buffer layer thickness is mainly inducing PMA in Mo/CFAS/MgO/Mo stack. Microstructural changes in the films are observed by atomic force microscopy (AFM). X-ray photoelectron spectroscopy (XPS) demonstrates the oxidation of CFAS/MgO interface and the formation of Fe-O bonds confirming that the real origin of PMA in Mo/CFAS/MgO is due to hybridization of Fe (3dz2) and O (2pz) orbitals and the resulted spin-orbit interaction at their interface. The half-metallic nature CFAS with Mo layer exhibiting PMA can be a potential candidate as p-MTJs electrodes for the new generation spintronic devices.

Room-temperature ferromagnetism in Fe-based perovskite solid solution in lead-free ferroelectric Bi0.5Na0.5TiO3 materials

Science.gov (United States)

Hung, Nguyen The; Bac, Luong Huu; Trung, Nguyen Ngoc; Hoang, Nguyen The; Van Vinh, Pham; Dung, Dang Duc

2018-04-01

The integration of ferromagnetism in lead-free ferroelectric materials is important to fabricate smart materials for electronic devices. In this work, (1 - x)Bi0.5Na0.5TiO3 + xMgFeO3-δ materials (x = 0-9 mol%) were prepared through sol-gel method. X-ray diffraction characterization indicated that MgFeO3-δ materials existed as a well solid solution in lead-free ferroelectric Bi0.5Na0.5TiO3 materials. The rhombohedral structure of Bi0.5Na0.5TiO3 materials was distorted due to the random distribution of Mg and Fe cations into the host lattice. The reduced optical band gap and the induced room-temperature ferromagnetism were due to the spin splitting of transition metal substitution at the B-site of perovskite Bi0.5Na0.5TiO3 and the modification by A-site co-substitution. This work elucidates the role of secondary phase as solid solution in Bi0.5Na0.5TiO3 material for development of lead-free multiferroelectric materials.

Structural, thermal, spectroscopic and magnetic studies of the (C2N2H10)0.5[Fe xV1-x(HPO3)2] (x = 0.26, 0.52, 0.74) solid solution

International Nuclear Information System (INIS)

Cisneros, Jose L.; Fernandez-Armas, Sergio; Mesa, Jose L.; Pizarro, Jose L.; Arriortua, Maria I.; Rojo, Teofilo

2006-01-01

The (C 2 N 2 H 10 ) 0.5 [Fe x V 1-x (HPO 3 ) 2 ] (x = 0.26, 0.52 0.74) compounds have been obtained by mild solvothermal conditions in the form of micro-crystalline powder with brown color. The crystal structures were refined by X-ray powder diffraction data using the Rietveld method. The compounds crystallize in the monoclinic system, space group P2/c with the unit-cell parameters, a = 9.262(5) A, b = 8.823(5) A, c = 9.714(6) A, β = 120.84(3) o ; a = 9.245(1) A, b = 8.823(1) A, c = 9.698(1)A, β = 120.80(1) o and, a = 9.254(4)A, b = 8.822(4)A, c = 9.702(4)A, β = 120.73(3) o for (C 2 N 2 H 10 ) 0.5 [Fe 0.26 V 0.74 (HPO 3 ) 2 ] (1) (C 2 N 2 H 10 ) 0.5 [Fe 0.52 V 0.48 (HPO 3 ) 2 ] (2), and (C 2 N 2 H 10 ) 0.5 [Fe 0.74 V 0.26 (HPO 3 ) 2 ] (3). The compounds show an open crystalline structure with three-dimensional character, whose formula for the anionic inorganic skeleton is [M(HPO 3 ) 2 ] 2- . The inorganic framework is formed by [MO 6 ] octahedra inter-connected by phosphite groups. The structure of the compounds exhibits channels extended along the [1 0 0] and [0 0 1] directions and the ethylendiammonium cations are located inside these channels, linked through hydrogen bonds and ionic interactions. The infrared spectra show the bands corresponding to the stretching (P-H) vibration of the phosphite group and the band corresponding to the deformation mode of the ethylendiammonium cation, δ(NH 3 + ). The thermal and thermodiffractometric behavior show that the compounds are stable up to approximately 300 deg. C, at higher temperatures the decomposition of the crystal structure by calcination of the organic cation starts. The diffuse reflectance spectra show bands of the V 3+ ion (d 2 ), and a band of the Fe 3+ ion (d 5 ), in a slightly distorted octahedral symmetry. The values of the Dq and Racah parameters (B and C) have been calculated for the V(III) cation. Magnetic measurements were performed on a powdered sample from 5 to 300 K at magnetic fields 1000, 500

Spin-dependent electronic transport characteristics in Fe4N/BiFeO3/Fe4N perpendicular magnetic tunnel junctions

Science.gov (United States)

Yin, Li; Wang, Xiaocha; Mi, Wenbo

2018-01-01

Perpendicular magnetic tunnel junctions (MTJs) have attracted increasing attention owing to the low energy consumption and wide application prospects. Herewith, against Julliere's formula, an inverse tunnel magnetoresistance (TMR) appears in tetragonal Fe4N/BiFeO3/Fe4N perpendicular MTJs, which is attributed to the binding between the interface resonant tunneling state and central (bordered) hot spots. Especially, antiferromagnetic BiFeO3 shows an extra spin-polarized resonant state in the barrier, which provides a magnetic-barrier factor to affect the tunneling transport in MTJs. Meanwhile, due to the spin-polarized transport in Fe4N/BiFeO3/Fe4N MTJs, the sign of TMR can be tuned by the applied bias. The tunable TMR and resonant magnetic barrier effect pave the way for clarifying the tunneling transport in other junctions and spintronic devices.

Fabrication of highly spin-polarized Co2FeAl0.5Si0.5 thin-films

Directory of Open Access Journals (Sweden)

M. Vahidi

2014-04-01

Full Text Available Ferromagnetic Heusler Co2FeAl0.5Si0.5 epitaxial thin-films have been fabricated in the L21 structure with saturation magnetizations over 1200 emu/cm3. Andreev reflection measurements show that the spin polarization is as high as 80% in samples sputtered on unheated MgO (100 substrates and annealed at high temperatures. However, the spin polarization is considerably smaller in samples deposited on heated substrates.

Synthesis of high aspect ratio of Ni 0.5Zn 0.5Fe 2O 4 platelets for electromagnetic devices

Science.gov (United States)

Hallynck, Sylvain; Pourroy, Geneviève; Vilminot, Serge; Jacquart, Pierre-Marie; Autissier, Denis; Vukadinovic, Nicolas; Pascard, Hubert

2006-01-01

Ni 0.5Zn 0.5Fe 2O 4 ferrite platelets of 5 to 300 μm have been obtained by reaction in a molten salt between hematite platelets, NiO and ZnO powders. The hematite platelets are obtained by a hydrothermal treatment in an alkaline medium between 180 and 270 °C through a dissolution-recrystallization mechanism from maghemite which crystallizes first. The key parameter for size control is the mixture alkalinity. The largest platelets are obtained for [Fe 3+] = 2.0 mol dm -3 and [OH -] = 15.3 N. The size distribution is narrow and the aspect ratio about 30. The reaction with nickel and zinc oxides yields the formation of polycrystalline platelets through a topotactic reaction allowing the platelet morphology, initial shape and size to be conserved. SEM observations reveal the ferrite platelets are made of adjacent micronic ferrite crystals with their [111] faces parallel to the platelet surface. Increasing the reaction temperature promotes an enlargement of the [111] faces. The respective solubilities of oxides and ferrites in the molten salts control the ferrite stoichiometry. KCl as a flux gives better results than NaCl with no modification of the crystal shape and no ZnO loss.

Structure and cation distribution of (Mn0.5Zn0.5)Fe2O4 thin films on SrTiO3(001)

Science.gov (United States)

Welke, M.; Brachwitz, K.; Lorenz, M.; Grundmann, M.; Schindler, K.-M.; Chassé, A.; Denecke, R.

2017-06-01

A comprehensive study on growth of ferrimagnetic manganese zinc ferrite (Mn0.5Zn0.5Fe2O4) films on single crystalline strontium titanate(001) (SrTiO3) substrates was carried out. Under the optimized conditions, a thin film with a layer thickness of 200 nm was deposited, and the structural properties were investigated. Contrary to data published in literature, no buffer layer was necessary to achieve epitaxial growth of a poorly lattice-matched layer. This was confirmed for Mn0.5Zn0.5Fe2O4(001) on SrTiO3(001) by x-ray diffraction and the adjoined phi scans, which also revealed a lattice compression of 1.2% of the manganese zinc ferrite film in the out-of-plane direction. Using x-ray photoelectron spectroscopy, the near surface stoichiometry of the film could be shown to agree with the intended one within the uncertainty of the method. X-ray absorption spectroscopy showed an electronic structure close to that published for bulk samples. Additional x-ray magnetic circular dichroism investigations were performed to answer detailed structural questions by a comparison of experimental data with the calculated ones. The calculations took into account ion sites (tetrahedral vs. octahedral coordination) as well as the charge of Fe ions (Fe2+ vs. Fe3+). Contrary to the expectation for a perfect normal spinel that only Fe3+ ions are present in octahedral sites, hints regarding the presence of additional Fe2+ in octahedral sites as well as Fe3+ ions in tetrahedral sites have been obtained. Altogether, the layer could be shown to be mostly in a normal spinel configuration.

Mechanism of γ-irradiation induced phase transformations in nanocrystalline Mn{sub 0.5}Zn{sub 0.5}Fe{sub 2}O{sub 4} ceramics

Energy Technology Data Exchange (ETDEWEB)

Jagadeesha Angadi, V. [Department of Physics, Bangalore University, Bangalore, Karnataka 560056 (India); Anupama, A.V.; Choudhary, Harish K.; Kumar, R. [Materials Research Centre, Indian Institute of Science, Bangalore, 560012 (India); Somashekarappa, H.M. [Center for Application of Radioisotopes and Radiation Technology, Mangalore University, Mangalore 574199 (India); Mallappa, M. [Department of Chemistry, Government Science College, Bangalore 560001 (India); Rudraswamy, B. [Department of Physics, Bangalore University, Bangalore, Karnataka 560056 (India); Sahoo, B., E-mail: bsahoo@mrc.iisc.ernet.in [Materials Research Centre, Indian Institute of Science, Bangalore, 560012 (India)

2017-02-15

The structural, infrared absorption and magnetic property transformations in nanocrystalline Mn{sub 0.5}Zn{sub 0.5}Fe{sub 2}O{sub 4} samples irradiated with different doses (0, 15, 25 and 50 kGy) of γ-irradiation were investigated in this work and a mechanism of phase transformation/decomposition is provided based on the metastable nature of the Mn-atoms in the spinel lattice. The nano-powder sample was prepared by solution combustion route and the pellets of the sample were exposed to γ-radiation. Up to a dose of 25 kGy of γ-radiation, the sample retained the single phase cubic spinel (Fd-3m) structure, but the disorder in the sample increased. On irradiating the sample with 50 kGy γ-radiation, the spinel phase decomposed into new stable phases such as α-Fe{sub 2}O{sub 3} and ZnFe{sub 2}O{sub 4} phases along with amorphous MnO phase, leading to a change in the surface morphology of the sample. Along with the structural transformations the magnetic properties deteriorated due to breakage of the ferrimagnetic order with higher doses of γ-irradiation. Our results are important for the understanding of the stability, durability and performance of the Mn-Zn ferrite based devices used in space applications. - Graphical abstract: The nanocrystalline Mn{sub 0.5}Zn{sub 0.5}Fe{sub 2}O{sub 4} ceramic sample transforms to crystalline α-Fe{sub 2}O{sub 3} and ZnFe{sub 2}O{sub 4} phases (and amorphous MnO phase) at a γ-irradiation dose of 50 kGy, as MnO goes out of the spinel lattice. The high energy γ-irradiation causes structural damage to the nanomaterials leading to change in morphology of the sample as seen in the SEM images. - Highlights: • Mn atoms are more unstable in the Mn-Zn ferrite spinel lattice than Zn-atoms. • Displacement of Mn atoms by γ-radiation from the lattice renders phase transformation. • In Mn{sub 0.5}Zn{sub 0.5}Fe{sub 2}O{sub 4}, Mn-ferrite cell transforms to crystalline α-Fe{sub 2}O{sub 3} and amorphous MnO. • The stable ZnFe{sub 2}O

Fabrication of Fe1.1Se0.5Te0.5 bulk by a high energy ball milling technique

Science.gov (United States)

Liu, Jixing; Li, Chengshan; Zhang, Shengnan; Feng, Jianqing; Zhang, Pingxiang; Zhou, Lian

2017-11-01

Fe1.1Se0.5Te0.5 superconducting bulks were successfully synthesized by a high energy ball milling (HEBM) aided sintering technique. Two advantages of this new technique have been revealed compared with traditional solid state sintering method. One is greatly increased the density of sintered bulks. It is because the precursor powders with β-Fe(Se, Te) and δ-Fe(Se, Te) were obtained directly by the HEBM process and without formation of liquid Se (and Te), which could avoid the huge volume expansion. The other is the obvious decrease of sintering temperature and dwell time due to the effective shortened length of diffusion paths. The superconducting critical temperature Tc of 14.2 K in our sample is comparable with those in previous reports, and further optimization of chemical composition is on the way.

Stability and oxygen transport property of La0.8Sr0.2Cr0.5Fe0.5O3 -δ

DEFF Research Database (Denmark)

He, Wei; Huang, Hua; Chen, Ming

2014-01-01

vacancies in the lattice. LSCrF powder exposed to flowing concentrated hydrogen for 30 h was found to decompose partially. The decomposition oxygen partial pressure of LSCrF at 950 °C was estimated to be 6.3 × 10- 28 atm from thermodynamic calculations. The stability of LSCrF under an oxygen chemical......The stability of La0.8Sr0.2Cr0.5Fe 0.5O3 -δ (LSCrF) in reducing atmosphere was investigated by examining the extent of its reaction with hydrogen at elevated temperature. LSCrF powder exposed to diluted hydrogen was found to loss a weight of only ~ 0.5%, corresponding to the formation of oxygen...... potential gradient was also examined by exposing a disk-shaped dense sample to air at one side and to reducing atmosphere (CO) at the other side at elevated temperatures. A thin, porous layer was found to form on the CO side surface. An oxygen permeation flux of 2.5 × 10- 7 mol cm- 2 s- 1 was observed...

Magnetoelectric properties of microwave sintered BiFeO{sub 3} and Bi{sub 0.90}La{sub 0.10}Fe{sub 0.95}Mn{sub 0.05}O{sub 3} nanoceramics

Energy Technology Data Exchange (ETDEWEB)

Kolte, Jayant, E-mail: jayantkolte@gmail.com [Department of Metallurgical Engineering and Materials Science, Indian Institute of Technology Bombay, Mumbai (India); Daryapurkar, A.S., E-mail: asdarypaurkar@gmail.com [Department of Basic Sciences, Indian Institute of Information Technology, Nagpur (India); Agarwal, Mohit, E-mail: mohit2705@gmail.com [Department of Electronics and Communication Engineering, Thapar University, Patiala, Punjab (India); Gulwade, D.D., E-mail: devidasgulwade@gmail.com [Department of Physics, V.E.S. College of Arts, Commerce and Science, Chembur, Mumbai (India); Gopalan, P., E-mail: pgopalan@iitb.ac.in [Department of Metallurgical Engineering and Materials Science, Indian Institute of Technology Bombay, Mumbai (India)

2017-06-01

Multiferroic materials have attracted the attention of scientific community all over the world due to smart functionality and attractive applications such as in magnetoelectric memory and magnetoelectric sensors. In this paper, we report on the ferroelectric, magnetic and magnetoelectric properties of microwave sintered BiFeO{sub 3} (BFO) and Bi{sub 0.90}La{sub 0.10}Fe{sub 0.95}Mn{sub 0.05}O{sub 3} (BLFMO) ceramics. The ferromagnetic and paramagnetic components have been deconvoluted using standard magnetization equation. The ferromagnetic saturation and paramagnetic susceptibility for BFO are found to be 0.046 emu/g and 1.17 × 10{sup -5} emu/g·Oe respectively. The magnetization in BLFMO increases enormously as compared to BFO due to suppression of cycloid spin. The magnetoelectric voltage coefficient for BFO is 3.37 mV/cm·Oe, while for BLFMO it is 10.11 mV/cm·Oe. As compared to BFO, BLFMO exhibits improved ferroelectric, magnetic and magnetoelectric properties. - Highlights: • Ferromagnetic and paramagnetic components calculated from total magnetization. • Magnetoelectric and magnetodielectric coefficients of BFO and BLFMO were measured. • BFO shows linear change in magnetoelectric voltage coefficient with ac magnetic field. • Both BFO and BLFMO follows Ginzburg Landau equation for multiferroics. • Relative to BFO, BLFMO exhibits leakage current that is three order lower.

MIL-100-Fe derived N-doped Fe/Fe3C@C electrocatalysts for efficient oxygen reduction reaction

Science.gov (United States)

Guo, Dakai; Han, Sancan; Wang, Jiacheng; Zhu, Yufang

2018-03-01

N-doped porous Fe/Fe3C@C electrocatalysts were prepared by the pyrolysis of the hexamethylenetetramine (HMT)-incorporated MIL-100-Fe at different temperatures (700-1000 °C) under N2 atmosphere. Rotary evaporation of MIL-100-Fe and HMT solution could make more N-enriched HMT molecules enter into the pores of MIL-100-Fe, thus improving nitrogen contents of the final pyrolyzed samples. All pyrolyzed samples show porous textures with middle specific surface areas. The X-ray photoelectron spectroscopy (XPS) results demonstrate the successful introduction of N atoms into carbon framework. Sample Fe-N2-800 prepared by annealing the precursors with the HMT/MIL-100-Fe weight ratio of 2 at 800 °C exhibits the best electrocatalytic activity towards the oxygen reduction reaction (ORR) in terms of onset potential and current density because of high graphitic N and pyridinic N content. The enwrapped Fe/Fe3C nanoparticles and Fe-Nx active sites in these samples could also boost the ORR activity synergistically. Moreover, sample Fe-N2-800 demonstrates a dominant four electron reduction process, as well as excellent long-term operation stability and methanol crossover resistance. Thus, the N-doped Fe/Fe3C@C composites derived from the HMT-incorporated MIL-100-Fe are promising electrocatalysts to replace Pt/C for ORR in practical applications.

Investigations on FCAM-III (Ca2.38Mg2.09Fe3+10.61Fe2+1.59Al9.33O36): A new homologue of the aenigmatite structure-type in the system CaO-MgO-Fe2O3-Al2O3

Science.gov (United States)

Zöll, Klaus; Kahlenberg, Volker; Krüger, Hannes; Tropper, Peter

2018-02-01

In the course of a systematic study of a part of the quaternary system Fe2O3-CaO-Al2O3-MgO (FCAM) the previously unknown compound Ca2.38Mg2.09Fe3+10.61Fe2+1.59Al9.33O36 (FCAM-III) has been synthesized. By analogy with the so-called SFCA series [1-5], our investigation in the system of FCAM shows the existence of a stoichiometric homologous series M14+6nO20+8n, where M = Fe, Ca, Al, Mg and n = 1 or 2. In air, we can prove the formation of coexisting FCAM-III and FCAM-I solid solutions at 1400 °C. By increasing the temperature up to 1425 °C FCAM-I disappears completely and FCAM-III co-exists with magnesiumferrite and a variety of calcium iron oxides. At 1450 °C FCAM-III breaks down to a mixture of FCAM-I again as well as magnesioferrite and melt. Small single-crystals of FCAM-III up to 35 μm in size could be retrieved from the 1425 °C experiment and were subsequently characterized using electron microprobe analysis and synchroton X-ray single-crystal diffraction. Finally the Fe2+/Fetot ratio was calculated from the total iron content based on the crystal-chemical formula obtained from EMPA measurements and charge balance considerations. FCAM-III or Ca2.38Mg2.09Fe3+10.61Fe2+1.59Al9.33O36 has a triclinic crystal structure (space group P 1 ̅). The basic crystallographic data are: a = 10.223(22) Å, b = 10.316(21) Å, c = 14.203(15) Å, α = 93.473(50)°, β = 107.418(67)°, γ = 109.646(60)°, V = 1323.85(2) ų, Z = 1. Using Schreinemaker's technique to analyze the phase relations in the system Fe2O3-CaO-Al2O3-MgO it was possible to obtain the semi-quantitative stability relations between the participating phases and construct a topologically correct phase sequence as a function of T and fO2. The analysis shows that Ca2Al0.5Fe1.5O5 (C2A0.25F0.75) and CaAl1.5Fe2.5O7 (CA0.75F1.25) with higher calculated Fe2+ contents are preferably formed at lower oxygen fugacity and react to CaAl0.5Fe1.5O4 (CA0.25F0.75) by increasing fO2. Spinel-type magnesium

Measurement of 54Fe(n,2n)53Fe cross section near threshold

International Nuclear Information System (INIS)

Smither, R.K.; Greenwood, L.R.

1984-01-01

A series of experiments were performed at the Princeton Plasma Physics Laboratory to measure the cross section of the 54 Fe(n,2n) 53 Fe reaction near threshold. Measurements were made at 6 different neutron energies and cover the 1 MeV energy range from threshold (13.64 MeV) to 14.64 MeV. The 54 Fe(n,2n) cross section was measured relative to the 27 Al(n,p) 27 Mg cross section to an accuracy of a few percent. These accurate cross-section measurements will be useful in calculating damage caused by 14 MeV D-T plasma neutrons in Fe and calculating the production of the long-lived 53 Mn nuclei that account for much of the buildup of long-lived radioactivity in steel structures and other ferrous materials used in the construction of fusion reactors. They will also play an important part in a new method for measuring the plasma ion temperature of a D-T plasma

The aesthetic interpretation on Wooden Drum Dancing of Wa people

Directory of Open Access Journals (Sweden)

Youfeng Wang

2017-02-01

Full Text Available The Wa nationality, a typical ethnic group in Yunnan province, is an ancient one lives across Yunnan. The main residences of it are border area beside northern Yunnan and the Wa States in Burma. Among all the Wa dances, Wooden Drum Dancing leads a vital position, and it is also a symbolic dancing in the culture of Wa people. The feature of Wooden Drum Dancing is that every action expending by the beats of wooden drum, namely, first the wooden drum, then the Wooden Drum Dancing. Dancing is an important content in the life of Wa people, and the aesthetics of life comes from dancing, so they present their value on worship by the form of dancing. This article is going to interpret the aesthetic standard on Wa people’s Wooden Drum Dancing by the view of aesthetics, and come into a conclude that the inspiration of such dancing came from practice and their worship to nature and ancestor. The Wooden Drum Dancing displays totally the tough air and solidarity of Wa people, which also presents the fair society of them. The Wooden Drum Dancing is an enriched art that Wa People took from particle life, so dancing of Wa is often classified into the aesthetic area of plain. The information of people’s living situation displayed by Wa dancing also conveys their rich emotions. The sense of beauty within Wooden Drum Dancing will give others a solemn feeling. The formal beauty is displayed by the rhythm of upper part of body, and the power beauty is displayed by the rhythm of the lower part of body.

Ferrites Ni{sub 0,5}Zn{sub 0,5}Fe{sub 2}O{sub 4} doped with samarium: structural analysis, morphological and electromagnetic; Ferritas Ni{sub 0,5}Zn{sub 0,5}Fe{sub 2}O{sub 4} dopada com samario: analise estrutural, morfologica e eletromagnetica

Energy Technology Data Exchange (ETDEWEB)

Costa, A.C.F.M.; Diniz, A.P., E-mail: anacristina@dema.ufcg.edu.br [Universidade Federal de Campina Grande (UFCG), PB (Brazil). Unidade Academinca de Engenharia de Materiais; Viana, K.M.S. [Universidade Federal do Rio Grande do Norte (UFRN), Natal, PE (Brazil). Escola de Ciencias e Tecnologia; Cornejo, D.R. [Universidade de Sao Paulo (USP), SP (Brazil). Instituto de Fisica; Kiminami, R.H.G.A. [Universidade Federal de Sao Carlos (UFSCar), SP (Brazil). Departamento de Engenharia de Materiais

2010-07-01

This paper proposes to investigate the sintering at 1200 deg C/2h of Ni{sub 0.5}Zn{sub 0.5}Fe{sub 2-x}Sm{sub x}O{sub 4} ferrite doped with 0.05; 0.075 e 0.1 mol of Sm synthesized by combustion reaction to evaluate the performance materials as absorbers of electromagnetic radiation. The influence of the concentration of samarium on the structure, morphology and electromagnetic properties of ferrites was studied. The resulting samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), magnetic measurements and reflectivity measurements in the frequency range between 8-12 GHz. The results showed that increasing the concentration of samarium caused a decrease in particle size of the samples, encouraging, therefore, to obtain materials with better values of magnetization and reflectivity, allowing for use as absorbers in narrow-band frequency between 9-10 GHz. (author)

The effects of bedroom air quality on sleep and next-day performance.

Science.gov (United States)

Strøm-Tejsen, P; Zukowska, D; Wargocki, P; Wyon, D P

2016-10-01

The effects of bedroom air quality on sleep and next-day performance were examined in two field-intervention experiments in single-occupancy student dormitory rooms. The occupants, half of them women, could adjust an electric heater to maintain thermal comfort but they experienced two bedroom ventilation conditions, each maintained for 1 week, in balanced order. In the initial pilot experiment (N = 14), bedroom ventilation was changed by opening a window (the resulting average CO2 level was 2585 or 660 ppm). In the second experiment (N = 16), an inaudible fan in the air intake vent was either disabled or operated whenever CO2 levels exceeded 900 ppm (the resulting average CO2 level was 2395 or 835 ppm). Bedroom air temperatures varied over a wide range but did not differ between ventilation conditions. Sleep was assessed from movement data recorded on wristwatch-type actigraphs and subjects reported their perceptions and their well-being each morning using online questionnaires. Two tests of next-day mental performance were applied. Objectively measured sleep quality and the perceived freshness of bedroom air improved significantly when the CO2 level was lower, as did next-day reported sleepiness and ability to concentrate and the subjects' performance of a test of logical thinking. © 2015 The Authors. Indoor Air published by John Wiley & Sons Ltd.

Failure of wooden sandwich beam reinforced with glass/epoxy faces

Energy Technology Data Exchange (ETDEWEB)

Papakaliatakis, G. E.; Zacharopoulos, D. A. [Department of Civil Engineering, Democritus University of Thrace, Xanthi, 67100, Greece gpapakal@civil.duth.gr, dzachar@civil.duth.gr (Greece)

2015-12-31

The mechanical properties and the failure of wooden beam strengthened with two faces from glass/epoxy composite and a wooden beam without strengthening was studied. Stresses and deflections on both beams, which are imposed in three point bending loading. On the idealized geometry of the specimens with detailed nonlinear orthotropic analysis was performed with a finite elements program. The failure study of the wooden beams was performed, applying the criterion of Tsai-Hill. The shear strength of the adhesive was taken into account. All the specimens were tested with three point bending loading and the experimental results were compared to those of the theoretical approach with the finite elements analysis. Comparing the results, the advantage of strengthened wooden beam against the simple wooden beam becomes obvious. Theoretical predictions were in good agreement with experimental results.

Ferro and antiferro orbital ordering in Fe{sub 0.5}Mn{sub 0.5}V{sub 2}O{sub 4}

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Dey, Dibyendu, E-mail: dibyendu@phy.iitkgp.ernet.in; Taraphder, A. [Department of Physics, Indian Institute of Technology, Kharagpur 721302 (India); Maitra, T. [Department of Physics, Indian Institute of Technology, Roorkee 247667 (India)

2016-05-23

Using density functional theory calculations, we have investigated the orbital ordering in Fe{sub 0.5}Mn{sub 0.5}V{sub 2}O{sub 4} where Fe and V sites are orbitally active. Our first principles study within GGA+U and GGA+U+SO shows ferro-orbital ordering of d{sub x2−y2} orbital at all Fe sites, whereas A-type antiferro-orbital ordering at V sites where one 3d electron occupies d{sub xy} orbital at every V site and another electron occupies either 1/√2 (d{sub xz} + d{sub yz}) or 1/√2 (d{sub xz} - d{sub yz}) orbital alternatively along c axis. Insulating nature and the orbital ordering of this compound are found to be correlation driven while the effect of spin-orbit interaction on orbital ordering is not significant.

Lithium intercalation mechanism into FeF3·0.5H2O as a highly stable composite cathode material

Science.gov (United States)

Ali, Ghulam; Lee, Ji–Hoon; Chang, Wonyoung; Cho, Byung-Won; Jung, Hun-Gi; Nam, Kyung-Wan; Chung, Kyung Yoon

2017-02-01

The growing demand for lithium-ion batteries (LIBs) requires investigation of high-performance electrode materials with the advantages of being environmentally friendly and cost-effective. In this study, a nanocomposite of open-pyrochlore-structured FeF3·0.5H2O and reduced graphene oxide (RGO) is synthesized for use as a high-performance cathode in LIBs, where RGO provides high electrical conductivity to the composite material. The morphology of the composite shows that FeF3·0.5H2O spheres are embedded into RGO layers and high-resolution TEM image shows that those spheres are composed of primary nanoparticles with a size of ~5 nm. The cycling performance indicates that the composite electrode delivers an initial high discharge capacity of 223 mAh g-1 at 0.05 C, a rate capability up to a high C-rate of 10 C (47 mAh g-1) and stable cycle performance at 0.05 C (145 mAh g-1 after 100 cycles) and 0.2 C (93 mAh g-1 after 100 cycles) while maintaining high electrochemical reversibility. Furthermore, the responsible electrochemical reaction is investigated using in-situ XRD and synchrotron-based X-ray absorption spectroscopy (XAS), and the XRD results show that FeF3·0.5H2O transitions to an amorphous-like phase through a lithiation process. However, a reversible oxidation change of Fe3+ ↔ Fe2+ is identified by the XAS results.

Electrical properties and phase transition of Ba(Zr{sub 0.05}Ti{sub 0.95}){sub 1−x}(Fe{sub 0.5}Ta{sub 0.5}){sub x}O{sub 3} ceramics

Energy Technology Data Exchange (ETDEWEB)

Kruea-In, C. [Faculty of Science and Technology, Chiang Mai Rajabhat University (Thailand); Rujijanagul, G., E-mail: rujijanagul@yahoo.com [Department of Physics and Materials Science, Faculty of Science, Chiang Mai University (Thailand)

2015-09-15

Highlights: • Properties of of Ba(Zr{sub 0.05}Ti{sub 0.95}){sub 1−x}(Fe{sub 0.5}Ta{sub 0.5}){sub x}O{sub 3} ceramics were investigated. • Small amount of dopant produced a large change in dielectric and phase transition. • A phase diagram of Ba(Zr{sub 0.05}Ti{sub 0.95}){sub 1−x}(Fe{sub 0.5}Ta{sub 0.5}){sub x}O{sub 3} ceramics was proposed. • Dielectric tunability increased with increasing x concentration. - Abstract: In this work, properties of Ba(Zr{sub 0.05}Ti{sub 0.95}){sub 1−x}(Fe{sub 0.5}Ta{sub 0.5}){sub x}O{sub 3} ceramics with 0.00≤ x ≤0.07 were investigated. The ceramics were fabricated by a solid state reaction technique. X-ray diffraction analysis indicated that all samples exhibited single phase perovskite. Examination of the dielectric spectra revealed that the Fe and Ta additives promoted a diffuse phase transition, and the two phase transition temperatures, as observed in the dielectric curve of pure Ba(Zr{sub 0.05}Ti{sub 0.95})O{sub 3}, merged into a single phase transition temperature for higher x concentrations. The transformation was confirmed by ferroelectric measurements. In addition, the doped ceramics exhibited high relative dielectric tunability, especially for higher x concentration samples.

Are Pets in the Bedroom a Problem?

Science.gov (United States)

Krahn, Lois E; Tovar, M Diane; Miller, Bernie

2015-12-01

The presence of pets in the bedroom can alter the sleep environment in ways that could affect sleep. Data were collected by questionnaire and interview from 150 consecutive patients seen at the Center for Sleep Medicine, Mayo Clinic in Arizona. Seventy-four people (49%) reported having pets, with 31 (41% of pet owners) having multiple pets. More than half of pet owners (56%) allowed their pets to sleep in the bedroom. Fifteen pet owners (20%) described their pets as disruptive, whereas 31 (41%) perceived their pets as unobtrusive or even beneficial to sleep. Health care professionals working with patients with sleep concerns should inquire about the presence of companion animals in the sleep environment to help them find solutions and optimize their sleep. Copyright © 2015 Mayo Foundation for Medical Education and Research. Published by Elsevier Inc. All rights reserved.

Cinética de engrosamiento de precipitados coherentes en la aleación Fe-10 % Ni-15 % Al

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Cayetano-Castro, N.

2008-04-01

Full Text Available The coarsening kinetics and the morphology evolution of the coherent β’ (Fe, NiAl precipitates embedded in a ferritic matrix were studied in the aged Fe-10 % Ni-15 % Al alloy. Samples were solution treated at 1,100°C for 24 h and subsequently aged at 750, 850 and 920 °C for different times. XRD, SEM and TEM results showed the following decomposition reaction after aging treatment, α_sss → α + β. Intragranular particles distribution changes from a random to an aligned on the elastically soft <100> crystallographic directions of the matrix. Additionally, the morphological evolution of the precipitates was as follows: spheres → cuboids → parallelepipeds → plates. The variation of the cube of mean radius of particles, r³, and the particle density as a function of time followed a linear relationship, as predicted by the Lifshitz, Slyosov and Wagner (LSW theory for diffusion-controlled coarsening. The rate constant (K increased with the aging temperature. The activation energy for coarsening process was determined to be about of 220 kJ/mol.

La cinética de engrosamiento y la evolución morfológica de precipitados coherentes β’ (Fe, NiAl en una matriz ferrítica se estudió en la aleación Fe-10 % Ni-15 % Al. Se solubilizaron muestras a 1.100 °C por 24, y posteriormente, se envejecieron a 750, 850 y 920 °C por diferentes tiempos. Los resultados de DRX, MEB y MET mostraron la descomposición, α_sss → α + β, durante su envejecido. La distribución de precipitados dentro del grano cambia, gradualmente, de aleatoria a un alineamiento preferencial sobre las direcciones cristalográficas <100> de la matriz. Asimismo, la evolución morfológica de los precipitados fue: esféricos → cúbicos → paralelepípedos → placas. La variación del tamaño de partícula, r³, y la densidad de precipitados en función del tiempo se comportan linealmente, como lo predice la teoría de Lifshitz

Ni_0_,_5Zn_0_,_5Fe_2O_3 ferrite synthesized by combustion and Pechini method for use in nanomedicine: methods evaluation

International Nuclear Information System (INIS)

Albuquerque, I.L.T. de; Nascimento, A.L.C.; Costa, A.C.F.M.

2016-01-01

The objective of this work was to synthesize the Ni0.5Zn0.5Fe2O3 ferrite by combustion reaction and Pechini method, and to evaluate structural characteristics and magnetic behavior for its use in nanomedicine. The synthesized ferrite was characterized by DRX, BET, TG and magnetic properties. According to the results of XRD, the Ni_0_,_5Zn_0_,_5Fe_2O_3 ferrite synthesized by both methods presented nano crystallite sizes, high crystallinity, surface area, stable at high temperatures and with high saturation magnetization, being higher in the ferrite synthesized by combustion reaction. Both methods produced materials that could be used in nanomedicine

The influence of Fe doping on the surface topography of GaN epitaxial material

International Nuclear Information System (INIS)

Cui Lei; Yin Haibo; Jiang Lijuan; Wang Quan; Feng Chun; Xiao Hongling; Wang Cuimei; Wang Xiaoliang; Gong Jiamin; Zhang Bo; Li Baiquan; Wang Zhanguo

2015-01-01

Fe doping is an effective method to obtain high resistivity GaN epitaxial material. But in some cases, Fe doping could result in serious deterioration of the GaN material surface topography, which will affect the electrical properties of two dimensional electron gas (2DEG) in HEMT device. In this paper, the influence of Fe doping on the surface topography of GaN epitaxial material is studied. The results of experiments indicate that the surface topography of Fe-doped GaN epitaxial material can be effectively improved and the resistivity could be increased after increasing the growth rate of GaN materials. The GaN material with good surface topography can be manufactured when the Fe doping concentration is 9 × 10 19 cm −3 . High resistivity GaN epitaxial material which is 1 × 10 9 Ω·cm is achieved. (paper)

Parental restriction reduces the harmful effects of in-bedroom electronic devices.

Science.gov (United States)

Fu, King-Wa; Ho, Frederick Ka Wing; Rao, Nirmala; Jiang, Fan; Li, Sophia Ling; Lee, Tatia Mei-Chun; Chan, Sophelia Hoi-Shan; Yung, Ada Wing-Yan; Young, Mary Eming; Ip, Patrick

2017-12-01

To investigate whether school readiness could be affected by placing electronic devices (EDs) in children's bedroom and whether the relationship was moderated by parental restriction and family socioeconomic status (SES). This is a cross-sectional study with bedroom ED placement and parental restriction reported by parents. Multiple linear regressions were used to test the relationship between school readiness and ED placement. Multiple regression with interaction terms were used to test whether the effect was consistent with and without parental restriction. Kindergartens randomly selected from two districts of different socioeconomic backgrounds in Hong Kong, China. 556 young children attending the third year of kindergarten. Children's school readiness was rated by teachers using the Chinese Early Development Instrument. 556 preschoolers (mean age 5.46; 51.8% girls) from 20 kindergartens participated in this study. About 30% of parents placed at least one ED in their children's bedroom. After controlling for sex and SES, the placement of television in the bedroom was associated with lower overall school readiness (β -1.11, 95% CI -1.80 to -0.42) and the placement of game console was associated with lower social competence (β-0.94, 95% CI -1.74 to -0.15). Such harmful effect was more prominent among lower SES families and could be partially alleviated with parental restriction. ED placement in children's bedroom was associated with lower school readiness, particularly among lower SES families. Parental restriction might help to alleviate the harm. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Effect of 120 MeV 28Si9+ ion irradiation on structural and magnetic properties of NiFe2O4 and Ni0.5Zn0.5Fe2O4

Science.gov (United States)

Sharma, R.; Raghuvanshi, S.; Satalkar, M.; Kane, S. N.; Tatarchuk, T. R.; Mazaleyrat, F.

2018-05-01

NiFe2O4, Ni0.5Zn0.5Fe2O4 samples were synthesized using sol-gel auto combustion method, and irradiated by using 120 MeV 28Si9+ ion with ion fluence of 1×1012 ions/cm2. Characterization of pristine, irradiated samples were done using X-Ray Diffraction (XRD), Field Emission Scanning Microscopy (FE-SEM), Energy Dispersive X-ray Analysis (EDAX) and Vibrating Sample Magnetometer (VSM). XRD validates the single phase nature of pristine, irradiated Ni- Zn nano ferrite except for Ni ferrite (pristine, irradiated) where secondary phases of α-Fe2O3 and Ni is observed. FE- SEM images of pristine Ni, Ni-Zn ferrite show inhomogeneous nano-range particle size distribution. Presence of diamagnetic ion (Zn2+) in NiFe2O4 increases oxygen positional parameter (u 4¯3m ), experimental, theoretical saturation magnetization (Msexp., Msth.), while decreases the grain size (Ds) and coercivity (Hc). With irradiation Msexp., Msth. increases but not much change are observed in Hc. New antistructure modeling for the pristine, irradiated Ni and Ni-Zn ferrite samples was used for describing the surface active centers.

High dielectric constant observed in (1 − x)Ba(Zr0.07Ti0.93)O3–xBa(Fe0.5Nb0.5)O3 binary solid-solution

International Nuclear Information System (INIS)

Kruea-In, Chatchai; Eitssayeam, Sukum; Pengpat, Kamonpan; Rujijanagul, Gobwute

2012-01-01

Binary solid-solutions of the (1 − x)Ba(Zr 0.07 Ti 0.93 )O 3 –xBa(Fe 0.5 Nb 0.5 O 3 ) system, with 0.1 ≤ x ≤ 0.9,were fabricated via a solid-state processing technique. X-ray diffraction analysis revealed that all samples exhibited a single perovskite phase. The BaFe 0.5 Nb 0.5 O 3 also promoted densification and grain growth of the system. Dielectric measurements showed that all samples displayed a relaxor like behavior. The x = 0.1 sample presented a dielectric-frequency and temperature with low loss tangent ( 0.2 samples, the dielectric data showed a broad dielectric constant–temperature curve with a giant dielectric characteristic. In addition, a high dielectric constant > 50,000 (at 10 kHz and temperature > 150 °C) was observed for the x = 0.9 sample.

2018-05-05T10:34:30Z https://www.ajol.info/index.php/all/oai oai:ojs ...

African Journals Online (AJOL)

article/11400 2018-05-05T10:34:30Z njcp:ART AIDS-associated Kaposi\\'s Sarcoma in Sokoto, Nigeria. Mbah, N Abdulkareem, IH Panti, A Kaposi\\'s sarcoma, Prevalence, Northwestern Nigeria, HIV/AIDS. Background: Since the advent of the ...

Sorption of organic gases in residential bedrooms andbathrooms

Energy Technology Data Exchange (ETDEWEB)

Singer, B.C.; Hodgson, A.T.; Hotchi, T.; Ming, K.Y.; Sextro,R.G.; Wood, E.E.; Brown, N.J.

2005-01-05

Experiments were conducted to characterize organic gas sorption in residential bedrooms (n=4), bathrooms (n=2), and a furnished test chamber. Rooms were studied ''as-is'' with material surfaces and furnishings unaltered. Surface materials were characterized and areas quantified. Experiments included rapid volatilization of a volatile organic compound (VOC) mixture with the room closed and sealed for a 5-h Adsorb phase, followed by 30-min Flush and 2-h closed-room Desorb phases. The mixture included n-alkanes, aromatics, glycol ethers, 2-ethyl-1-hexanol, dichlorobenzene, and organophosphorus compounds. Measured gas-phase concentrations were fit to three variations of a mathematical model that considers sorption occurring at one surface sink and one potential embedded sink. The 2-parameter sink model tracked measurements for most compounds, but improved fits were obtained for some VOCs with a 3-parameter sink-diffusion or a 4-parameter two-sink model. Sorptive partitioning and initial adsorption rates increased with decreasing vapor pressure within each chemical class.

Phase transitions in Fe{sub 0.5}Co{sub 0.5} (110) thin films

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Ramírez-Dámaso, G., E-mail: gramirezd@ipn.mx [Escuela Superior de Ingeniería y Arquitectura “Unidad Ticomán” del Instituto Politécnico Nacional, Av. Ticomán No. 600, Col. San José Ticomán, Del. G. A. M., C. P. 07330 Ciudad de México (Mexico); Castillo-Alvarado, F.L. [Escuela Superior de Física y Matemáticas del Instituto Politécnico Nacional, Edificio 9, Col. San Pedro Zacatenco, C. P. 07738 Ciudad de México (Mexico); Rojas-Hernández, E. [Escuela Superior de Ingeniería y Arquitectura “Unidad Ticomán” del Instituto Politécnico Nacional, Av. Ticomán No. 600, Col. San José Ticomán, Del. G. A. M., C. P. 07330 Ciudad de México (Mexico)

2016-12-15

In this paper, we present calculations for two second-order phase transitions in (110) Fe{sub 0.5}Co{sub 0.5} thin films with 11, 15, and 19 monoatomic layers. The lattice and magnetic transitions are based on thermodynamic equilibrium considerations of the magnetic alloy. The procedure proposed by Valenta and Sukiennicki was applied to calculate the composition x(i), the lattice order parameter t(i), and the magnetic order parameter σ(i) as a function of temperature T. We confirmed that both phase transitions, lattice and magnetic, are of the second order, in accordance with experimental results in the literature. The obtained behavior of these parameters indicates their inhomogeneity due to the boundary conditions on the surfaces of the thin film.

Climate in unheated bedrooms of the minimum energy houses in Schiedam, Netherlands. Klimaat in onverwarmde slaapkamers van de minimumenergiewoningen te Schiedam

Energy Technology Data Exchange (ETDEWEB)

Dubbeld, M.; Molenaar, J.; Van Schijndel, L.L.; Ham, P.J.

1987-03-01

The temperature and humidity of the bedrooms in four energy saving dwellings equipped with multi-burners for space heating are measured. The bedrooms have no separate heating. It is determinded if and how the acquired bedroom temperature is reached. The inhabitants reach the acquired bedroom temperature by closing the shutters at night and internal circulation of hot air between living room and bedroom. It is indicated how one heater can heat the bedrooms even without air transport from living room to the bedrooms. It is also indicated how the transport of cooking smells can be improved. 11 figs., 5 refs., 1 tab., 3 apps.

In situ X-ray diffraction characterisation of Fe0.5TiOPO4 and Cu0.5TiOPO4 as electrode material for sodium-ion batteries

International Nuclear Information System (INIS)

Bleith, Peter; Kaiser, Hermann; Novák, Petr; Villevieille, Claire

2015-01-01

Na-ion batteries might become a low-cost alternative to Li-ion batteries in the future. Suitable electrode materials, especially anode materials, are needed for Na-ion batteries. As possible candidates Cu 0.5 TiOPO 4 and Fe 0.5 TiOPO 4 were tested. While Cu 0.5 TiOPO 4 does not react with Na + , Fe 0.5 TiOPO 4 shows a specific charge of ≈600 mAh/g upon the first sodiation and 280 mAh/g in the first desodiation. In situ XRD in a new, versatile and reliable in situ cell revealed that Fe 0.5 TiOPO 4 reacts via a conversion type reaction upon sodiation with an amorphisation of the sample

Orientation and magnetic properties of the thick multilayered [NdFeBxTby]n films

International Nuclear Information System (INIS)

Liu, Weifang; Suzuki, Shunji; Machida, Kenichi

2007-01-01

Multilayered [NdFeB x /Tb y ] n films were prepared by a three-demensional sputtering system. From the thickness of NdFeB layer dependence on the orientation and magnetic properties of multilayered [NdFeB (xμm)/Tb (50nm)] n films with 7.2μm as a total thickness of NdFeB layers, it was found that the orientation of NdFeB grains was maintained. However, the coercivity was enhanced with decreasing the thickness of each NdFeB thin layer. The (BH) max value of 240kJ/m 3 was obtained on the layered [NdFeB (1.2μm)/Tb (50 nm)] 6 film as an optimal value. For the multilayered [NdFeB (1.2μm)/Tb (50 nm)] n films with various multiple layer sets (n), the coercivity value increased with the film thickness without any deterioration of the c-axis texture and consequently, multilayered NdFeB/Tb film magnets with total thickness values around 70μm showed the superior magnetic properties (H cj approx. = 1360kA/m, I r approx.= 1.05T, and (BH) max approx.= 202kJ/m 3 ). (author)

La fracción evaporativa en diferentes regiones agrícolas y naturales del centro-noroeste de la Argentina

Directory of Open Access Journals (Sweden)

E.S Luna Toledo

2013-06-01

Full Text Available La fracción evaporativa (FE permite cuantificar la porción de la energía disponible usada en el proceso de evapotranspiración. Se obtuvo la distribución espacial de la FE para cinco tipos de cobertura: árboles, cultivos, pastizales, arbustos y suelo desnudo de cinco ecorregiones del centro-noroeste de la Argentina, usando productos del sensor MODIS-TERRA. FE se calculó mediante el método triangular según la relación entre la fracción de la cobertura de suelo (Fr y la temperatura de superficie (Ts. Ambas variables fueron correlacionadas para cada tipo de cobertura por ecorregión. Fr y Ts están inversamente asociadas, y diferentes coberturas por ecorregiones mostraron cambios en la pendiente de la recta entre ambas variables debido a cambios en el porcentaje y el tipo de cobertura, en los gradientes pluviométricos y en la estructura de la vegetación. Los valores medios de Fr y FE por ecorregiones y tipo de cobertura fueron procesados mediante el análisis de la varianza y por comparaciones múltiples de Fisher. Existen diferencias estadísticas significativas en las variables Fr y FE según el tipo de cobertura, y la ecorregión y la relación entre Fr y FE no es lineal. Finalmente, se generó un mapa con la distribución espacial de la FE.

Wooden Calendar Sticks in Eastern Europe

Science.gov (United States)

Koleva, Vesselina; Koleva, Svetlana

Wooden calendar sticks have preserved an archaic time-keeping tradition, which, during the Middle Ages, was one of the tools for establishing and disseminating Christian chronology and the liturgical calendars of the Western and Eastern Churches. The calendars vary in size and shape, type of signs, and structure of the record. Christian symbols interwoven with signs and pictograms mark days of importance in the ritual and economic year cycle. The wooden calendars are considered one of the proofs of the syncretism between the pagan tradition and Christian rites in folk cultures.

Investigation on magnetoelectric behavior of (80Bi0.5Na0.5TiO3-20Bi0.5K0.5TiO3)-CoFe2O4 particulate composites

Science.gov (United States)

Liu, Sheng; Yan, Shuoqing; Yao, Lingling; He, Jun; He, Longhui; Hu, Zhaowen; Huang, Shengxiang; Deng, Lianwen

2017-12-01

Particulate magnetoelectric (ME) ceramics constituted by (1-x)(80Bi0.5Na0.5TiO3-20Bi0.5K0.5TiO3)-xCoFe2O4 [(1-x)BNKT-xCFO] (x = 0, 0.1, 0.2, 0.3, 0.4 and 1.0) were synthesized by an powder-in-sol precursor hybrid processing method and their structure, magnetic, ferroelectric, magnetodielectric (MD) and ME properties have been investigated. Results showed that the ceramics consisted of only two chemically separated phases and had homogeneous microstructure. The introduction of CFO into BNKT matrix led to the weakening of ferroelectric and dielectric properties whereas the strengthening magnetic and MD properties. The observation of the MD effect revealed the evidence of the strain-induced ME coupling and the MD value is well scaled with M2. A maximum value of ME output of 25.07 mV/cm·Oe was achieved for the 0.7BNKT-0.3CFO composite. The improved ME response together with the linear MD effect makes the ceramics promise for use in magnetic field controllable devices or magneto-electric transducers.

Predictors of indoor fine particulate matter in infants' bedrooms in Denmark

DEFF Research Database (Denmark)

Raaschou-Nielsen, Ole; Sørensen, Mette; Hertel, Ole

2011-01-01

conducted 1122 measurements of fine PM (PM2.5 and black smoke) in the bedrooms of 389 infants and registered indoor activities and characteristics of the house. We used mixed models to identify and quantify associations between predictors and concentrations. Results The concentration of PM2.5 was 2.8 times....... Frying without a range hood was associated with a 32% (95% CI, 12–54%) higher PM2.5 concentration per time per day, whereas frying with use of a range hood did not increase the concentration in the infant’s bedroom. Use of a fireplace, stove, candles or vacuum-cleaner, interior rebuilding or renovation......, local traffic, inner city residence and cold season increased the fine PM concentration. Open windows decreased the PM2.5 concentration in homes with smokers but increased the concentration in non-smoking homes. Conclusions We identified several sources of fine PM in infants’ bedrooms...

The research of glued frame-mounted wooden constructions

Directory of Open Access Journals (Sweden)

Muselemov Kh.M.

2016-11-01

Full Text Available the authors of this article note that the fast pace and modern construction make qualitatively new demands on building materials and structures. While great attention is paid to the production of glued wooden structures. Such designs on a number of technical and economic indicators are superior to metal and concrete have low component weight, relatively high strength and stiffness with sufficient reliability and durability. At the same time, negative characteristics of the wood (the dependence of the properties from its structure, defects, need for and considerable expense of quality timber, excessive massiveness of the cross-sections, creep under sustained loading, etc. restrict the scope and impair the indicators of glued wooden structures. One of the ways to address these shortcomings and increase techno-economic efficiency – reinforcement of sections of glued wooden structures and elements of steel or fiberglass reinforcement. This can significantly reduce the consumption of wood, reduce Assembly mass, to improve the quality and reliability of wooden structures, working mainly in bending and compression with bending.

Delayed Collapse of Wooden Folding Stairs

Science.gov (United States)

Krentowski, Janusz; Chyzy, Tadeusz

2017-10-01

During operation of folding stairs, a fastener joining the ladder hanger with the frame was torn off. A person using the stairs sustained serious injury. In several dozen other locations similar accidents were observed. As a result of inspections, some threaded parts of the screws were found in the gaps between the wooden elements of the stairs’ flaps. In the construction a hatch made of wooden strips is attached to an external frame by means of metal hangers. Laboratory strength tests were conducted on three samples made of wooden elements identical to the ones used in the damaged stairs. Due to complex load distribution mechanism acting on the base of the structure, a three-dimensional FEM model was created. An original software was used for calculations. Five computational model variants were considered. As a result of the numerical analyses, it was unquestionably shown that faulty connections were the cause of the destruction of the stairs. The weakest link in the load transmission chain were found to have been the screws connecting the hatch board with the hangers.

The Study of Stages and Operations Involved in the Preservation and Restoration of two XIX-th Century Icons, on Wooden Support

Directory of Open Access Journals (Sweden)

Marius Munteanu

2014-10-01

Full Text Available The paper presents the stages and the operations involved in the preservation and restoration of two icons on wooden support, from the XIX-th century, which are part of the heritage of the ”Sfinții Arhangheli Mihail and Gavriil” church, from Galați. The two icon have inventory numbers as part of the collection as followed: 112 for the first icon and 113 for the second one. Both icons have the same theme, ”The Grieving Mother from Rohia” and are made by anonymous painters in egg tempera, on lime wooden support, without ground. Being part of the same collection, they were deposited in the same place and as a direct consequence, they suffer from similar deteriorations and degradations that affect both the support and the painting layer. Both panels are attacked by xylophagous insects and the painting layer has detachments, gaps, cracks, clogged dirt and a cracked and degraded varnish layer. Ten samples taken from the already detached areas were analyzed by optical microscope, SEM-EDX and micro-FTIR. Based on the chemical elements identified in the EDX spectrums, the pigments used to create the painting layer are: ultramarine natural blue Na8-10Al6Si6O24S2-4, carbon black, earth green, K[(Al,FeIII,(FeII,Mg](AlSi3,Si4O10(OH2, ocher (FeO, burned or natural umber Fe2O3· H2O + MnO2·n H2O+ Al2O3, lead white (2PbCO3·Pb(OH2 and yellow iron oxide (Fe2O3·4H2O. It was also determined that the gold leaf usually used in byzantine icons was replaced in the case of both icons: the icon number 112 has silver leaf covered with varnish, while the halo of the icon number 113 was created with yellow metallic pigments (realgar or orpigment.The pigments were also identified by determining specific peaks in micro-FTIR spectrums. For natural ultramarine blue the peaks between 628 - 724 cm-1 were assigned; the peaks in the interval 795 - 887 cm-1 confirm the presence of carbonates (calcium and lead based. The earth green pigment (aluminum - silicates had the

Evaluación de algunos métodos para la extracción de los micronutrimentos B, Fe, Zn, Mn y Cu en suelos de las zonas norte y centro del Valle del Cauca

Directory of Open Access Journals (Sweden)

García O. Álvaro

1988-12-01

Full Text Available Para evaluar el contenido de Fe, Cu, Mn y Zn disponibles en el suelo se usaron: EDTA 0.01M + NaHCD3 0.5 N, HCI 0.05 N + H2SD4, DTPA y HCI 0.1N. El B disponible fue extraído con Ca(H2PD42H20 0.008 M, HCI 0.05N y NH40Ac pH 4.8. Para la determinación de los micronutrimentos en el material vegetal se usaron como soluciones para la digestión el metanol ácido y la mezcla nítrico perclórica para Fe, Mn, Cu y Zn; para el B se usó el método de Hunter. El DTP A resultó adecuado para evaluar Fe y Cu, el doble ácido para Mn, el NaHC03 + EDTA para el Zn y el HCI 0.05N y Ca (H2P042 H20 para evaluar el B disponible en el suelo. La mezcla nítrico perclórica resultó más apropiada para la determinación de los nutrimentos en los tejidos que el metanol ácido.To evaluate available Fe, Cu, Mn and Zn was used: EDTA 00.1M + NaHC03 0.5N, HCI 0.05N + H2S04 0.025N, DTPA and HCI 0.1 N. Available B was extracted with Ca (H2P042 H2O 0.008M; HCI 0.05N and NH40Ac pH 4.8. For determination of micronutriment in the vegetal material was used as solution acid methanol and nitric – perchloric mixture for Fe, Mn, Cu and Zn; for B Hunters methods. DTPA is advantageous to evaluate Fe and Cu, double acid to Mn, NaHC03 + EDTA to Zn and HCI 0.05N and Ca(H2P042 H20 to evaluate B available in the soil. Nitric-perchloric mixture is most advantageous for determination of nutriments in the tissues than acid methanol.

Processing and characterization of AlCoFeNiXTi{sub 0,5} (X = Mn, V) high entropy alloys; Processamento e caracterizacao de ligas de alta entropia AlCoFeNixTi{sub 0,5} (X = Mn, V)

Energy Technology Data Exchange (ETDEWEB)

Triveno Rios, C., E-mail: carlos.triveno@ufabc.edu.br [Universidade Federal do ABC (CECS/UFABC), Santo Andre, SP (Brazil). Engenharia de Materiais; Lopes, E.S.N.; Caram, R. [Universidade Estadual de Campinas (FEM/DEMA/UNICAMP), Campinas, SP (Brazil); Kiminami, C.S. [Universidade Federal de Sao Carlos (DEMa/UFSCar), Sao Carlos, SP (Brazil). Departamento de Engenharia de Materiais

2014-07-01

The microstructure of high entropy alloys consists of solid solution phases with FC and BCC simple structures, contrary to classical metallurgy where they form complex structures of intermetallic compounds. Because of this they have several attractive properties for engineering applications. In this work the AlCoFeNiMnTi{sub 0,5} and AlCoFeNiVTi{sub 0,5} alloys were processed by melting arc. Since the main objective was the microstructural and mechanical characterization of ingots as-cast. The alloys were characterized by scanning electron microscopy, X-ray diffraction, microhardness and cold compression test. The results showed that the microstructure consists mainly of dendrites and interdendritic regions consisting of metastable crystalline phases. It was also observed that the AlCoFeNiVTi{sub 0,5} alloy showed better mechanical properties than the AlCoFeNiMnTi{sub 0,5} alloy. This may be associated with differences in the parameters of formation of simple solid solution phases between the two alloys. (author)

Correlating structural, magnetic, and luminescence properties with the cation distribution of Co{sub 0.5}Zn{sub 0.5+x}Fe{sub 2–x}O{sub 4} nanoferrite

Energy Technology Data Exchange (ETDEWEB)

Wahba, Adel Maher, E-mail: a_m_wahba@yahoo.co.uk [Department of Engineering Physics and Mathematics, Faculty of Engineering, Tanta University (Egypt); Mohamed, Mohamed Bakr [Ain shams University, Faculty of Science, Physics Department, Cairo (Egypt); Imam, N.G. [Experimental Physics Department, Nuclear Research Center, Atomic Energy Authority, 13759 Cairo (Egypt)

2016-06-15

Structural, magnetic, and luminescence properties have been investigated for Co{sub 0.5}Zn{sub 0.5+x}Fe{sub 2−x}O{sub 4} nanoferrite (0.0≤x≤0.4, with a step increment of 0.1) prepared by citrate autocombustion method. X-ray diffraction (XRD) patterns and Fourier-transform infrared (FTIR) spectra proved the formation of a pure cubic spinel phase for all AP samples. Although the ionic radius of Zn{sup 2+} is larger than that of either Fe{sup 3+} or Co{sup 2+}, Rietveld analysis showed that the lattice parameter mostly decreases with increasing Zn substitution. The crystallite size of AP samples decreases gradually with increasing Zn substitution from 16 to 10 nm, which is confirmed with high-resolution (HRTEM) micrographs. Magnetic parameters such as saturation magnetization, coercivity, and remanent field obtained from vibrating sample magnetometry (VSM) revealed a strong dependence on the cation distribution being proposed according to the experimental data of XRD, FTIR, and VSM. The cation distribution indicated that introduced nonstoichiometry is compensated by oxidizing Co{sup 2+} into Co{sup 3+}, which explains the trend of the lattice parameter with increasing x. The distribution of Fe{sup 3+} ions between octahedral and tetrahedral sites was further confirmed by photoluminescence (PL) emission spectra. - Highlights: • Co{sub 0.5}Zn{sub 0.5+x}Fe{sub 2−x}O{sub 4} nanoferrites have been prepared by citrate-precursor method. • XRD peaks and IR bands confirmed pure spinel structure for all samples. • Structural, magnetic, and optical properties depend on the cation distribution. • A cation distribution was proposed based on the experimental data.

Internationalisation of the Malaysian Wooden Furniture Industry

OpenAIRE

Zhao, LiXu

2016-01-01

Malaysia has a strong market share in wooden furniture and the witnessed fast growth made it a leading furniture exporter. Currently, Malaysia is the 8th largest furniture export country. As an export dominated industry, the wooden furniture industry occupies a significant position in the Malaysian economic development. Since the industry is a challenged and deteriorating in global competition, the research objective is to evaluate the present situation and find out strategies on how to impro...

Fe3Nb3N precipitates of the Fe3W3C type in Nb stabilized ferritic stainless steel

International Nuclear Information System (INIS)

Malfliet, A.; Van den Broek, W.; Chassagne, F.; Mithieux, J.-D.; Blanpain, B.; Wollants, P.

2011-01-01

Highlights: → The precipitation in Nb stabilized ferritic stainless steel at 950 deg. C is investigated. → We characterized the Fe 3 Nb 3 X precipitates with SAED, EELS, WDS and AES. → We found that Fe 3 Nb 3 X precipitates are stabilized by N and not by C or O. → This insight is new and important for future development of this type of steel grade. - Abstract: A Nb stabilized ferritic stainless steel with 0.45 wt.%Nb, 82 ppm C and 170 ppm N is investigated to reveal the nature of the precipitates present at 950 deg. C. In particular, Fe 3 Nb 3 X precipitates of the Fe 3 W 3 C type are analyzed with WDS and EELS to determine the light elements X stabilizing this phase in the steel. According to WDS on large precipitates after 500 h at 950 deg. C, the Fe 3 Nb 3 X phase contains 10.4 at.% N, 1.2 at.% O and 1.0 at.% C. Auger Electron Spectroscopy on the same precipitates confirms the presence of N. In addition, it is revealed that the C and O peaks observed with WDS result from surface contamination as they disappear after Ar sputtering. The presence of a N peak in the EELS spectra of small Fe 3 Nb 3 X precipitates which have formed after 6 min at 950 deg. C indicate that N stabilizes this phase already from the initial precipitation stage. With this analysis it is demonstrated that N is an effective stabilizer of Fe 3 Nb 3 X precipitates in ferritic stainless steels. The formation of this phase should therefore be considered when predicting the precipitation behavior of Nb in industrial Nb stabilized ferritic stainless steels containing residual N.

Improved multiferroic properties in (1−x)BiFeO{sub 3}–xBaTi{sub 0.95}(Yb{sub 0.5}Nb{sub 0.5}){sub 0.05}O{sub 3} system (0≤x≤0.3)

Energy Technology Data Exchange (ETDEWEB)

Amouri, A., E-mail: amouri.amira00@gmail.com [Laboratoire des Matériaux Ferroélectriques (LMF), LR-Physique-Mathématiques et Applications, Université de Sfax, Faculté des Sciences de Sfax(FSS), Route de Soukra km3,5 B.P.1171, 3000 Sfax (Tunisia); Le laboratoire des Colloïdes, Verre, et Nanomatériaux, UMRCNRS 5587,Unité mixte de recherche 5587-CNRS-UM2-Université Montpellier 2, F-34095 Montpellier (France); Abdelmoula, N.; Khemakhem, H. [Laboratoire des Matériaux Ferroélectriques (LMF), LR-Physique-Mathématiques et Applications, Université de Sfax, Faculté des Sciences de Sfax(FSS), Route de Soukra km3,5 B.P.1171, 3000 Sfax (Tunisia)

2016-11-01

Polycrystalline samples of (1−x)BiFeO{sub 3}–xBaTi{sub 0.95}(Yb{sub 0.5}Nb{sub 0.5}){sub 0.05}O{sub 3} (x=0, 0.1, 0.2 and 0.3) were prepared by the conventional solid state reaction method. The phase purity and composition were cheeked using powder X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDX) and X-ray photoelectron spectroscopy (XPS). The grain size and morphology of the ceramics were confirmed by scanning electron microscopy (SEM). X-ray diffraction showed that these compounds crystallized, at room temperature, in the Rhomboedral R3c for x=0 and in tetragonal P4mm for compositions 0.1≤x≤0.3 distorted perovskite structures. The BaTi{sub 0.95}(Yb{sub 0.5}Nb{sub 0.5}){sub 0.05}O{sub 3} substitution led to an improvement of magnetic and ferroelectric properties at room temperature. The highest magnetization was reported for composition x=0.2 which was due to the enhancement of canting angles and the suppression of cycloid spin structure, as confirmed by {sup 57}Fe Mössbauer spectroscopy and the presence of Fe{sup 2+}, as detected by XPS. The electric polarization increased significantly for doped samples, which proves the enhancement of the ferroelectric behavior and resistivity of our ceramics. Large electric field induced strains were observed for 0.7BiFeO{sub 3}-0.3BaTi{sub 0.95}(Yb{sub 0.5}Nb{sub 0.5}){sub 0.05}O{sub 3}, as an evidence of piezoelectric behavior. These results show that BaTi{sub 0.95}(Yb{sub 0.5}Nb{sub 0.5}){sub 0.05}O{sub 3} doped BiFeO{sub 3} is a promising multiferroic material. - Highlights: • (1−x)BiFeO{sub 3}–xBa[Ti{sub 0.95}(Yb{sub 0.5}Nb{sub 0.5}){sub 0.05}]O{sub 3} is a new multiferroic system. • Doped BiFeO{sub 3} ceramics crystallize in tetragonal distorted perovskite. • Magnetic properties at room temperature were improved.

Enhanced photocatalytic property of BiFeO_3/N-doped graphene composites and mechanism insight

International Nuclear Information System (INIS)

Li, Pai; Li, Lei; Xu, Maji; Chen, Qiang; He, Yunbin

2017-01-01

Highlights: • A hydrothermal process was used to prepare BiFeO_3/N-doped graphene composites. • BiFeO_3/N-doped graphene exhibits superior photocatalytic activity and stability. • The energy band of BiFeO_3 bends downward by ∼1.0 eV at the composite interface. • Downward band bending leads to rapid electron transfer at the composite interface. • Holes and ·OH are predominant active species in the photo-degradation process. - Abstract: A series of BiFeO_3/(N-doped) graphene composites are prepared by a facile hydrothermal method. BiFeO_3/N-doped graphene shows photocatalytic performance superior to that of BiFeO_3/graphene and pristine BiFeO_3. The enhanced photo-degradation performance of BiFeO_3/N-doped graphene are mainly attributable to the improved light absorbance of the composite, abundant active adsorption sites and high electrical charge mobility of N-doped graphene, and the downward band bending of BiFeO_3 at the composite interface. In particular, X-ray photoelectron spectroscopy analyses reveal that the electron energy band of BiFeO_3 is downward bent by 1.0 eV at the interface of BiFeO_3/N-doped graphene, because of different work functions of both materials. This downward band bending facilitates the transfer of photogenerated electrons from BiFeO_3 to N-doped graphene and prompts the separation of photo-generated electron-hole pairs, leading eventually to the enhanced photocatalytic performance.

Processing and characterization of AlCoFeNiXTi0,5 (X = Mn, V) high entropy alloys

International Nuclear Information System (INIS)

Triveno Rios, C.; Kiminami, C.S.

2014-01-01

The microstructure of high entropy alloys consists of solid solution phases with FC and BCC simple structures, contrary to classical metallurgy where they form complex structures of intermetallic compounds. Because of this they have several attractive properties for engineering applications. In this work the AlCoFeNiMnTi 0,5 and AlCoFeNiVTi 0,5 alloys were processed by melting arc. Since the main objective was the microstructural and mechanical characterization of ingots as-cast. The alloys were characterized by scanning electron microscopy, X-ray diffraction, microhardness and cold compression test. The results showed that the microstructure consists mainly of dendrites and interdendritic regions consisting of metastable crystalline phases. It was also observed that the AlCoFeNiVTi 0,5 alloy showed better mechanical properties than the AlCoFeNiMnTi 0,5 alloy. This may be associated with differences in the parameters of formation of simple solid solution phases between the two alloys. (author)

Temperature-induced spin reorientation and magnetization jump of rare-earth orthoferrite Ho{sub 0.5}Pr{sub 0.5}FeO{sub 3} single crystal

Energy Technology Data Exchange (ETDEWEB)

Wang, Guohua; Zhao, Weiyao; Cao, Yiming; Kang, Baojuan [Department of Physics, and International Center of Quantum and Molecular Structures, Shanghai University, Shanghai 200444 (China); Zhang, Jincang [Department of Physics, and International Center of Quantum and Molecular Structures, Shanghai University, Shanghai 200444 (China); Materials Genome Institute, Shanghai University, Shanghai 200444 (China); Shanghai Key Laboratory of High Temperature Superconductors, Shanghai University, Shanghai 200444 (China); Ren, Wei, E-mail: renwei@shu.edu.cn [Department of Physics, and International Center of Quantum and Molecular Structures, Shanghai University, Shanghai 200444 (China); Materials Genome Institute, Shanghai University, Shanghai 200444 (China); Shanghai Key Laboratory of High Temperature Superconductors, Shanghai University, Shanghai 200444 (China); Cao, Shixun, E-mail: sxcao@shu.edu.cn [Department of Physics, and International Center of Quantum and Molecular Structures, Shanghai University, Shanghai 200444 (China); Materials Genome Institute, Shanghai University, Shanghai 200444 (China); Shanghai Key Laboratory of High Temperature Superconductors, Shanghai University, Shanghai 200444 (China)

2016-07-25

We report temperature-induced spin reorientation and magnetization jump effects in the rare earth (RE) orthoferrite Ho{sub 0.5}Pr{sub 0.5}FeO{sub 3} single crystal. The single crystal of about 6 mm in diameter and 50 mm in length was successfully grown by optical floating zone method. Both X-ray diffraction and Laue photograph confirmed the homogeneity and high quality of the crystal. Magnetic properties of Ho{sub 0.5}Pr{sub 0.5}FeO{sub 3} single crystal are studied over a wide temperature range from 2 to 300 K. Spin reorientation transition from Γ{sub 2} to Γ{sub 4} phase is observed in the temperature range of 75–90 K. At lower temperature, the Ho{sub 0.5}Pr{sub 0.5}FeO{sub 3} shows an abrupt jump of magnetization along the a-axis, which occurs only in the field-cooling process, and is sensitive to external applied magnetic field. By analyzing the jump temperature and magnitude of the magnetization, we conclude that it is caused by the spin reversal of the rare earth ions. The isothermal magnetization versus field hysteresis loop measurements along a axis explain the spin configuration variation from 3 K to 60 K. - Highlights: • Ho{sub 0.5}Pr{sub 0.5}FeO{sub 3} single crystal was grown by optical floating zone method. • It shows an abrupt jump of magnetization along a axis at low temperature. • The jump height and temperature is sensitive to external applied magnetic field. • It is attributed to the spin reversal of the rare earth ions.

Multiferroic Bi{sub 0.65}La{sub 0.35}Fe{sub 0.5}Sc{sub 0.5}O{sub 3} perovskite: Magnetic and thermodynamic properties

Energy Technology Data Exchange (ETDEWEB)

Fertman, E.L. [B. Verkin Institute for Low Temperature Physics and Engineering of NASU, Nauky 47, Kharkov 61103 (Ukraine); Fedorchenko, A.V. [B. Verkin Institute for Low Temperature Physics and Engineering of NASU, Nauky 47, Kharkov 61103 (Ukraine); Institute of Physics, Faculty of Sciences, P. J. Safarik University, Park Angelinum 9, 041 54 Košice (Slovakia); Khalyavin, D.D. [ISIS Facility, Rutherford Appleton Laboratory, Chilton, Didcot, Oxfordshire OX11 0QX (United Kingdom); Salak, A.N. [Department of Materials and Ceramic Engineering/CICECO, University of Aveiro, Aveiro 3810-193 (Portugal); Baran, A. [Department of Physics, Faculty of Electrical Engineering and Informatics, Technical University of Košice, Park Komenského 2, 042 00 Košice (Slovakia); Desnenko, V.A. [B. Verkin Institute for Low Temperature Physics and Engineering of NASU, Nauky 47, Kharkov 61103 (Ukraine); Kotlyar, O.V. [B. Verkin Institute for Low Temperature Physics and Engineering of NASU, Nauky 47, Kharkov 61103 (Ukraine); Institute of Physics, Faculty of Sciences, P. J. Safarik University, Park Angelinum 9, 041 54 Košice (Slovakia); Čižmár, E.; Feher, A. [Institute of Physics, Faculty of Sciences, P. J. Safarik University, Park Angelinum 9, 041 54 Košice (Slovakia); Syrkin, E.S. [B. Verkin Institute for Low Temperature Physics and Engineering of NASU, Nauky 47, Kharkov 61103 (Ukraine); Vaisburd, A.I. [V. N. Karazin Kharkiv National University, 4 Svobody sq., Kharkiv 61000 (Ukraine); Olekhnovich, N.M.; Pushkarev, A.V.; Radyush, Yu.V. [Scientific-Practical Materials Research Centre of NASB, P. Brovka 19, Minsk 220072 (Belarus); Stanulis, A.; Kareiva, A. [Faculty of Chemistry, Vilnius University, Naugarduko 24, Vilnius LT-03225 (Lithuania)

2017-05-01

Magnetic and thermodynamic properties of polycrystalline multiferroic Bi{sub 0.65}La{sub 0.35}Fe{sub 0.5}Sc{sub 0.5}O{sub 3} synthesized under high-pressure and high-temperature conditions are reported. Magnetic properties were studied using a SQUID magnetometer technique over the temperature range of 5−300 K in magnetic fields up to H=10 kOe. The field dependent magnetization M(H) was measured in magnetic fields up to 50 kOe at different temperatures up to 230 K after zero-field cooling procedure. A long-range magnetic ordering of the AFM type with a weak FM contribution occurs below the Néel temperature T{sub N} ~237 K. Magnetic hysteresis loops taken below T{sub N} show a huge coercive field up to H{sub c} ~10 kOe. A strong effect of magnetic field on the magnetic properties of the compound has been found. Derivative of the initial magnetization curves demonstrates a temperature-dependent anomaly in fields of H=15−25 kOe. Besides, an anomaly of the temperature dependent zero-field cooled magnetization measured in magnetic fields of 6−7 kOe has been found. Origin of both anomalies is associated with inhomogeneous magnetic state of the compound. The heat capacity has been measured from 2 K up to room temperature and a significant contribution from the magnon excitations at low temperatures has been detected. From the low-temperature heat capacity, an anisotropy gap of the magnon modes of the order 3.7 meV and Debye temperature T{sub D}=189 K have been determined. - Highlights: • A strong effect of magnetic field on the magnetic properties of the compound has been found. • Derivative of the initial magnetization curves demonstrates a temperature-dependent anomaly in fields of H=15−25 kOe. • A long-range antiferromagnetic ordering with a weak ferromagnetic contribution occurs below the Néel temperature T{sub N}~237 K. • Magnetic hysteresis loops taken below T{sub N} show a huge coercive field up to H{sub c}~10 kOe.

Growth and microstructure of iron nitride layers and pore formation in {epsilon}-Fe{sub 3}N

Energy Technology Data Exchange (ETDEWEB)

Middendorf, C.; Mader, W. [Univ. Bonn, Inst. fuer Anorganische Chemie, Bonn (Germany)

2003-03-01

Layers of {epsilon}-Fe{sub 3}N and {gamma}'-Fe{sub 4}N on ferrite were produced by nitriding iron single crystals or rolled sheets of iron in flowing ammonia at 520 C. The nitride layers were characterised using X-ray diffraction, light microscopy as well as scanning and transmission electron microscopy. The compound layer consists of {epsilon}-Fe{sub 3}N at the surface and of {gamma}'-Fe{sub 4}N facing the ferrite. After 4 h of nitriding, pores develop in the near surface region of {epsilon}-Fe{sub 3}N showing more or less open porosity. Growth of the entire compound layer as well as of the massive and the porous {epsilon}-Fe{sub 3}N sublayer is diffusion-controlled and follows a parabolic growth rate. The {gamma}'-Fe{sub 4}N layer is formed as a transition phase within a narrow interval of nitrogen activity, and it shows little growth in thickness. The transformation of {gamma}'-Fe{sub 4}N to {epsilon}-Fe{sub 3}N is topotactic, where the orientation of the closed-packed iron layers of the crystal structures is preserved. Determination of lattice plane spacings was possible by X-ray diffraction, and this was correlated to the nitrogen content of {epsilon}-Fe{sub 3}N. While the porous layer exhibits an enhanced nitrogen content corresponding to the chemical composition Fe{sub 3}N{sub 1.1}, the massive e Fe{sub 3}N layer corresponds to Fe{sub 3}N{sub 1.0}. The pore formation in {epsilon}-Fe{sub 3}N{sub 1.1} is concluded to be the result of excess nitrogen atoms on non-structural sites, which have a high mobility. Therefore, recombination of excess nitrogen to molecular N{sub 2} at lattice defects is preferred in {epsilon}-Fe{sub 3}N with high nitrogen content compared to stoichiometric {epsilon}-Fe{sub 3}N{sub 1.0} with nitrogen on only structural sites. (orig.)

Oxide ion diffusion mechanism related to Co and Fe ions in (Ba0.5Sr0.5)(Co0.8Fe0.2)O3-δ using in-situ X-ray absorption spectroscopy

Science.gov (United States)

Itoh, Takanori; Imai, Hideto

2018-03-01

The time changes of the white line and pre-edge intensities of Co and Fe K-edge in (Ba0.5Sr0.5)(Co0.8Fe0.2)O3-δ (BSCF) were observed to estimate the oxide ion diffusion related to Co and Fe ions by using in - situ X-ray absorption spectroscopy (XAS) during oxidation. The 20 μm self-standing BSCF film was prepared for in - situ XAS measurements. The time changes of absorption were fitted to the exponential decay function with two terms. The longer relaxation time (τ), related to the oxide ion diffusion during the oxidation of BSCF, is dependent on temperature. The oxide ion diffusion coefficients (D) were calculated from the τ s estimated by in - situ XAS. The values of the activation energy (Ea) for D related to Co K-edge white line, Co pre-edge, and Fe pre-edge were 1.8-2.0 eV. The value of Ea for D related to Fe K-edge white line, however, was higher than other absorption values at approximately 2.3 eV. We discussed the oxide ion diffusion mechanism related to Co and Fe ions in BSCF using in - situ XAS.

High dielectric constant observed in (1 − x)Ba(Zr{sub 0.07}Ti{sub 0.93})O{sub 3}–xBa(Fe{sub 0.5}Nb{sub 0.5})O{sub 3} binary solid-solution

Energy Technology Data Exchange (ETDEWEB)

Kruea-In, Chatchai [Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Eitssayeam, Sukum; Pengpat, Kamonpan [Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Materials Science Research Center, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Rujijanagul, Gobwute, E-mail: rujijanagul@yahoo.com [Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Materials Science Research Center, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand)

2012-10-15

Binary solid-solutions of the (1 − x)Ba(Zr{sub 0.07}Ti{sub 0.93})O{sub 3}–xBa(Fe{sub 0.5}Nb{sub 0.5}O{sub 3}) system, with 0.1 ≤ x ≤ 0.9,were fabricated via a solid-state processing technique. X-ray diffraction analysis revealed that all samples exhibited a single perovskite phase. The BaFe{sub 0.5}Nb{sub 0.5}O{sub 3} also promoted densification and grain growth of the system. Dielectric measurements showed that all samples displayed a relaxor like behavior. The x = 0.1 sample presented a dielectric-frequency and temperature with low loss tangent (<0.07 at 10 kHz). For x > 0.2 samples, the dielectric data showed a broad dielectric constant–temperature curve with a giant dielectric characteristic. In addition, a high dielectric constant > 50,000 (at 10 kHz and temperature > 150 °C) was observed for the x = 0.9 sample.

Electronic screens in children's bedrooms and adiposity, physical activity and sleep: do the number and type of electronic devices matter?

Science.gov (United States)

Chaput, Jean-Philippe; Leduc, Geneviève; Boyer, Charles; Bélanger, Priscilla; LeBlanc, Allana G; Borghese, Michael M; Tremblay, Mark S

2014-07-11

To examine whether the number and type of electronic screens available in children's bedrooms matter in their relationship to adiposity, physical activity and sleep. A cross-sectional study was conducted involving 502 children aged 9-11 years from Ottawa, Ontario. The presence (yes/no) of a television (TV), computer or video game system in the child's bedroom was reported by the parents. Percentage body fat was measured using bioelectrical impedance. An accelerometer was worn over seven days to assess moderate-to-vigorous physical activity (MVPA), total sedentary time, sleep duration and sleep efficiency. Screen time was self-reported by the child. After adjustment for age, sex, ethnicity, annual household income and highest level of parental education, children with 2-3 screens in their bedroom had a significantly higher percentage of body fat than children with no screen in their bedroom. However, while children with 2-3 screens in their bedroom engaged in more screen time overall than those with no screen, total sedentary time and MVPA were not significantly different. Sleep duration was not related to the number of screens in the bedroom, but sleep efficiency was significantly lower in children with at least 2 screens in the bedroom. Finally, children having only a TV in their bedroom had significantly higher adiposity than those having no screen at all. In contrast, the presence of a computer in children's bedrooms was not associated with higher adiposity than that of children with no screen. A higher number of screens in a child's bedroom was associated with higher adiposity, more total screen time and lower sleep efficiency. Having a TV in the bedroom appears to be the type of screen presence associated with higher levels of adiposity. Given the popularity of screens among children, these findings are increasingly relevant to health promotion strategies.

[The application of two occupation health risk assessment models in a wooden furniture manufacturing industry].

Science.gov (United States)

Wang, A H; Leng, P B; Bian, G L; Li, X H; Mao, G C; Zhang, M B

2016-10-20

Objective: To explore the applicability of 2 different models of occupational health risk assessment in wooden furniture manufacturing industry. Methods: American EPA inhalation risk model and ICMM model of occupational health risk assessment were conducted to assess occupational health risk in a small wooden furniture enterprises, respectively. Results: There was poor protective measure and equipment of occupational disease in the plant. The concentration of wood dust in the air of two workshops was over occupational exposure limit (OEL) , and the C TWA was 8.9 mg/m 3 and 3.6 mg/m 3 , respectively. According to EPA model, the workers who exposed to benzene in this plant had high risk (9.7×10 -6 ~34.3×10 -6 ) of leukemia, and who exposed to formaldehyde had high risk (11.4 × 10 -6 ) of squamous cell carcinoma. There were inconsistent evaluation results using the ICMM tools of standard-based matrix and calculated risk rating. There were very high risks to be attacked by rhinocarcinoma of the workers who exposed to wood dust for the tool of calculated risk rating, while high risk for the tool of standard-based matrix. For the workers who exposed to noise, risk of noise-induced deafness was unacceptable and medium risk using two tools, respectively. Conclusion: Both EPA model and ICMM model can appropriately predict and assessthe occupational health risk in wooden furniture manufactory, ICMM due to the relatively simple operation, easy evaluation parameters, assessment of occupational - disease - inductive factors comprehensively, and more suitable for wooden furniture production enterprise.

THE WOODEN GLUE STRUCTURES OF FOREIGN MODERN PEDESTRIAN BRIDGES

Directory of Open Access Journals (Sweden)

E. N. Trach

2015-02-01

Full Text Available A brief review on the application of wooden bridges is presented as well as wooden structures of modern pedestrian and road bridges built in recent years in the Western Europe are described. Based upon the review, the conclusions concerning the construction of similar structures in Ukraine are made.

Electric-field tunable perpendicular magnetic anisotropy in tetragonal Fe4N/BiFeO3 heterostructures

Science.gov (United States)

Yin, Li; Wang, Xiaocha; Mi, Wenbo

2017-07-01

Electric field control on perpendicular magnetic anisotropy (PMA) is indispensable for spintronic devices. Herewith, in tetragonal Fe4N/BiFeO3 heterostructures with the FeAFeB/Fe-O2 interface, PMA in each Fe4N layer, not merely interfacial layers, is modulated by the electric field, which is attributed to the broken spin screening of the electric field in highly spin-polarized Fe4N. Moreover, the periodical dx y+dy z+dz2 and dx y+dx2-y2 orbital-PMA oscillation enhances the interactions between adjacent FeAFeB and (FeB)2N atomic layers, which benefits the electric field modulation on PMA in the whole Fe4N atomic layers. The electric-field control on PMA in Fe4N/BiFeO3 heterostructures is favored by the electric-field-lifted potential in Fe4N.

Disorder- and correlation-induced charge carriers localization in oxyborate MgFeBO{sub 4}, Mg{sub 0.5}Co{sub 0.5}FeBO{sub 4}, CoFeBO{sub 4} single crystals

Energy Technology Data Exchange (ETDEWEB)

Knyazev, Yu.V. [Siberian Federal University, 660074 Krasnoyarsk (Russian Federation); Kazak, N.V., E-mail: nat@iph.krasn.ru [Kirensky Institute of Physics, 660036 Krasnoyarsk (Russian Federation); Platunov, M.S. [Kirensky Institute of Physics, 660036 Krasnoyarsk (Russian Federation); Ivanova, N.B. [Siberian Federal University, 660074 Krasnoyarsk (Russian Federation); Bezmaternykh, L.N. [Kirensky Institute of Physics, 660036 Krasnoyarsk (Russian Federation); Arauzo, A. [Servicio de Medidas Físicas, Universidad de Zaragoza, 50009 Zaragoza (Spain); Bartolomé, J. [Instituto de Ciencia de Materiales de Aragón, CSIC-Universidad de Zaragoza and Departamento de Física de la Materia Condensada, 50009 Zaragoza (Spain); Ovchinnikov, S.G. [Siberian Federal University, 660074 Krasnoyarsk (Russian Federation); Kirensky Institute of Physics, 660036 Krasnoyarsk (Russian Federation); Siberian State Aerospace University, 660014 Krasnoyarsk (Russian Federation)

2015-09-05

Highlights: • The electrical resistance of the single crystalline warwickites has been measured. • The temperature-induced changes in the charge transfer mechanisms have been found. • The microscopic parameters of the electronic structure have been determined. • The studied warwickites have been classified as disordered correlated systems. • The Co substitution was found to lead to the weakening of the localization. - Abstract: The temperature dependence of the resistivity of single crystalline Mg{sub 1−x}Co{sub x}FeBO{sub 4} samples with x = 0.0, 0.5, 1.0 is investigated for the temperature range (210–400 K). The conduction was found to be governed by Mott variable-range hopping (VRH) in the low-temperature range (T = 210–270 K) and by thermo-activation mechanism in the high-temperature range (T = 280–400 K). Microscopic electronic parameters, such as the density of the localized states near the Fermi level, localization length, the hopping length, and the activation energy have been obtained. The change of the activation energy observed at high-temperature range was attributed to local structure distortions around Fe and Co atoms. The complicated behavior of charge transfer mechanisms is discussed based on two approaches: atomic disorder and electron correlations.

Changes in CT density-measurement of intraorbital wooden foreign bodies

International Nuclear Information System (INIS)

Otani, Etsuko; Hiyama, Fusako; Machi, Setsuko; Hagihara, Masahiro.

1991-01-01

We examined in vitro changes in CT density-measurement of intraorbital wooden foreign bodies. Dry wooden sticks were immersed in distilled water, saline, and serum. Computerized tomography scans were taken several times during 22 weeks. Scans were taken in room air and in fatty tissue. The CT density-measurement of the central part of the wooden bodies was calculated. That of the dry wood was about 500 HU; all of the wooden foreign bodies became denser during the 22 weeks, with those immersed in distilled water and saline at about 130 HU, and those immersed in serum at about 150 HU. It was confirmed that wood becomes denser after soaking in aqueous environments. The CT density of wood soaked in water depends on the density of wood fiber, and the CT density of the wood fiber itself. (author)

Robust s± pairing in CaK (Fe1-xNix) 4As4 (x =0 and 0.05) from the response to electron irradiation

Science.gov (United States)

Teknowijoyo, S.; Cho, K.; Kończykowski, M.; Timmons, E. I.; Tanatar, M. A.; Meier, W. R.; Xu, M.; Bud'ko, S. L.; Canfield, P. C.; Prozorov, R.

2018-04-01

Controlled pointlike disorder introduced by 2.5-MeV electron irradiation was used to probe the superconducting state of single crystals of CaK (Fe1-xNix) 4As4 superconductor at x =0 and 0.05 doping levels. Both compositions show an increase of the residual resistivity and a decrease of the superconducting transition temperature, Tc, at the rate of d Tc/d ρ (Tc) ≈0.19 K/(μ Ω cm ) for x =0 and 0.38 K/(μ Ω cm ) for x =0.05 , respectively. In the Ni-doped compound (x =0.05 ), the coexisting spin-vortex crystal (SVC) magnetic phase is suppressed at the rate of d TN/d ρ (TN) ≈ 0.16 K/(μ Ω cm ). The low-temperature variation of London penetration depth is well approximated by the power-law function, Δ λ (T ) =A Tn , with n ≈2.5 for x =0 and n ≈1.9 for x =0.05 in the pristine state. Detailed analysis of λ (T ) and Tc evolution with disorder is consistent with two effective nodeless energy gaps in the density of states due to robust s± pairing. Overall the behavior of CaK (Fe1-xNix) 4As4 at x =0 is similar to a slightly overdoped Ba1 -yKyFe2As2 at y ≈ 0.5, and at x =0.05 to an underdoped composition at y ≈ 0.2.

Comparative studies of the dielectric properties of (1−x)BiFeO{sub 3}-xNi{sub 0.8}Zn{sub 0.2}Fe{sub 2}O{sub 4} (x=0.0, 0.2, 0.5, 0.8, 1.0) multiferroic nanocomposite with their single phase BiFeO{sub 3} and Ni{sub 0.8}Zn{sub 0.2}Fe{sub 2}O{sub 4}

Energy Technology Data Exchange (ETDEWEB)

Mani, Angom Devadatta, E-mail: angomdevadattamani@gmail.com; Soibam, Ibetombi

2017-02-15

BiFeO{sub 3} (BFO) and nickel zinc ferrite Ni{sub 0.8}Zn{sub 0.2}Fe{sub 2}O{sub 4} (NZFO) were prepared by sol gel and auto combustion route respectively. Stoichiometric proportions were mixed to obtain the multiferroic nanocomposites having the compositional formula (1−x)BiFeO{sub 3}-x Ni{sub 0.8}Zn{sub 0.2}Fe{sub 2}O{sub 4} (x=0.0, 0.2, 0.5, 0.8, 1.0). The phases were confirmed by XRD analyses. SEM micrographs showed the agglomerated nature of the particles with continuous grain growth in all directions. Elemental compositions were confirmed from EDAX studies. FTIR studies showed the stretching and bending vibrations of the various bonds present in the samples. The dielectric properties such as dielectric constant, ε′ and dielectric loss tangent, tanδ were studied for the spinel, perovskite and nanocomposite ferrites. Experimental result shows an increasing trend in the value of dielectric constant in going from spinel to perovskite phase. The frequency dependence of tanδ showed minimum loss for x=0.5 nanocomposite. Possible mechanisms explaining the above results were being discussed.

Indoor thermal environment of bedroom during sleep in Malaysia

Science.gov (United States)

Tsuzuki, Kazuyo; Mori, Ikue

2017-10-01

This study was conducted to investigate the indoor thermal environment and sleep of occupants in bedrooms where air conditioners (ACs) are preferentially installed. Field measurements and questionnaires were conducted for 22 houses, with a total of 28 occupants, located in the suburbs of Kuala Lumpur. The participants were requested to wear a wrist actigraphy on the non-dominant hand for three consecutive days, except while bathing or washing hands in order to evaluate sleep by the activity of the actigraphy. The average air temperatures in the bedrooms were 22.6-28.9 °C and 28.1-32.2 °C with and without AC, respectively. The observed lowest air temperature was below 21 °C in a bedroom with AC. Such low air temperatures are not considered appropriate in terms of energy consumption and the occupants' physiological condition during sleep. The wind velocity of fresh air coming through the open window was found as well as when the use of a fan. From the relations among the factors of thermal environment, increased wind velocity seems to compensate for increased air temperature and increased relative humidity. The sleep efficiency index (SEI) looks decreased in accordance with increased air temperature, increased air velocity, and increased relative humidity. However, no statistical significances were found in those relationships. New effective temperature (SET*) was calculated from measured thermal factors and relation was examined with SEI.

Cobalt-free perovskite Pr{sub 0.5}Sr{sub 0.5}Fe{sub 1−x}Cu{sub x}O{sub 3−δ} (PSFC) as a cathode material for intermediate temperature solid oxide fuel cells

Energy Technology Data Exchange (ETDEWEB)

Moura, Caroline G., E-mail: caroline.materiais@gmail.com [Materials Science and Engineering Postgraduate Program, UFRN, 59078-970, Natal (Brazil); Grilo, João Paulo de F. [Materials Science and Engineering Postgraduate Program, UFRN, 59078-970, Natal (Brazil); Macedo, Daniel A., E-mail: damaced@gmail.com [Materials Science and Engineering Postgraduate Program, UFPB, 58051-900, João Pessoa (Brazil); Cesário, Moisés R.; Fagg, Duncan Paul [Department of Mechanical Engineering, University of Aveiro, 3810-193, Aveiro (Portugal); Nascimento, Rubens M. [Materials Science and Engineering Postgraduate Program, UFRN, 59078-970, Natal (Brazil)

2016-09-01

PSFC (Pr{sub 0.5}Sr{sub 0.5}Fe{sub 1−x}Cu{sub x}O{sub 3−δ}) is a new perovskite-type oxide that has gained considerable attention as cathode material for intermediate temperature solid oxide fuel cells (IT-SOFCs), due to its high mixed ionic-electronic conductivity below 800 °C. In this work, PSFC (Pr{sub 0.5}Sr{sub 0.5}Fe{sub 1−x}Cu{sub x}O{sub 3−δ}, x = 0.2 and 0.4) powders were synthesized by the citrate method and structurally characterized by X-ray diffractometry. Screen-printed cathodes were sintered at 1050 °C and electrochemically characterized by impedance spectroscopy at 600–800 °C in pure oxygen. The area specific resistances (ASR) of the Pr{sub 0.5}Sr{sub 0.5}Fe{sub 0.8}Cu{sub 0.2}O{sub 3−δ} material are shown to be competitive with typical values reported for cobalt-based cathodes in the measured temperature range, while, importantly, offering a significantly lower activation energy, 0.62 eV. The thermal expansion coefficients of these Co-free cathodes are in the range of 13–15 × 10{sup −6} °C{sup −1}, in a temperature range 200–650 °C, demonstrating a good thermal compatibility with gadolinia doped ceria (CGO) electrolytes. - Highlights: • Cobalt-free Pr{sub 0.5}Sr{sub 0.5}Fe{sub 1−x}Cu{sub x}O{sub 3−δ} (PSFC) cathodes successfully prepared by the citrate method. • PSFC cathodes are thermally compatible with CGO electrolytes. • Pr{sub 0.5}Sr{sub 0.5}Fe{sub 0.8}Cu{sub 0.2}O{sub 3−δ} presents competitive area specific resistances of low activation energy, 0.62 eV.

Effect of La-substitution on structural, dielectric and electrical properties of (Bi{sub 0.5}Pb{sub 0.5}) (Fe{sub 0.5}Zr{sub 0.25}Ti{sub 0.25})O{sub 3}

Energy Technology Data Exchange (ETDEWEB)

Panda, Niranjan [Driems Engineering College, Department of Physics, Cuttack (India); Pattanayak, Samita [College of Engineering and Technology, Department of Physics, Bhubaneswar (India); Choudhary, R.N.P. [Siksha ' O' Anusandhan University, Department of Physics, Bhubaneswar (India); Kumar, Ashok [National Physical Laboratory (CSIR), New Delhi (India)

2016-09-15

As lead zirconium titanate and bismuth ferrite (BFO), members of perovskite family, have high dielectric constant and ferroelectric/ferromagnetic phase transition temperature, they are used for many potential applications including random access memory, sensors. The present work describes the modifications in the ferroelectric behaviour of PZT doped BFO due to substitution of few molar percent of La on Fe-site. A thorough comparative investigation of the frequency and temperature response of dielectric permittivity, dielectric loss, electric modulus, complex impedance and ferroelectric properties of Bi{sub 0.5}Pb{sub 0.5}[Fe{sub (0.5-x)}La{sub x}(Zr{sub 0.25}Ti{sub 0.25})] O{sub 3}, where x = 0.0, 0.1, 0.2, 0.3 (hence forth called as BFPZLTO) compounds were studied in a wide frequency range 10 kHz to 1 MHz at temperature range 25-400 C using ac impedance spectroscopy and electric modulus analysis. The structural analysis of compound revealed the tetragonal phase with space group P4 mm at room temperature. Cole-Cole plots are used for interpretation of relaxation mechanism in the materials. The materials especially the compound with x = 0.3 found more suitable to be used in transducers, RAMs, flip-flop memories, etc., for electronics applications. (orig.)

Hf{sub 3}Fe{sub 4}Sn{sub 4} and Hf{sub 9}Fe{sub 4−x}Sn{sub 10+x}: Two stannide intermetallics with low-dimensional iron sublattices

Energy Technology Data Exchange (ETDEWEB)

Calta, Nicholas P. [Department of Chemistry, Northwestern University (United States); Kanatzidis, Mercouri G., E-mail: m-kanatzidis@northwestern.edu [Department of Chemistry, Northwestern University (United States); Materials Science Division, Argonne National Laboratory (United States)

2016-04-15

This article reports two new Hf-rich intermetallics synthesized using Sn flux: Hf{sub 3}Fe{sub 4}Sn{sub 4} and Hf{sub 9}Fe{sub 4−x}Sn{sub 10+x}. Hf{sub 3}Fe{sub 4}Sn{sub 4} adopts an ordered variant the Hf{sub 3}Cu{sub 8} structure type in orthorhombic space group Pnma with unit cell edges of a=8.1143(5) Å, b=8.8466(5) Å, and c=10.6069(6) Å. Hf{sub 9}Fe{sub 4−x}Sn{sub 10+x}, on the other hand, adopts a new structure type in Cmc2{sub 1} with unit cell edges of a=5.6458(3) Å, b=35.796(2) Å, and c=8.88725(9) Å for x=0. It exhibits a small amount of phase width in which Sn substitutes on one of the Fe sites. Both structures are fully three-dimensional and are characterized by pseudo one- and two-dimensional networks of Fe–Fe homoatomic bonding. Hf{sub 9}Fe{sub 4−x}Sn{sub 10+x} exhibits antiferromagnetic order at T{sub N}=46(2) K and its electrical transport behavior indicates that it is a normal metal with phonon-dictated resistivity. Hf{sub 3}Fe{sub 4}Sn{sub 4} is also an antiferromagnet with a rather high ordering temperature of T{sub N}=373(5) K. Single crystal resistivity measurements indicate that Hf{sub 3}Fe{sub 4}Sn{sub 4} behaves as a Fermi liquid at low temperatures, indicating strong electron correlation. - Graphical abstract: Slightly different growth conditions in Sn flux produce two new intermetallic compounds: Hf{sub 3}Fe{sub 4}Sn{sub 4} and Hf{sub 9}Fe{sub 4−x}Sn{sub 10+x}. - Highlights: • Single crystals of both Hf{sub 3}Fe{sub 4}Sn{sub 4} and Hf{sub 9}Fe{sub 4−x}Sn{sub 10+x} were grown using Sn flux. • The crystal structures were determined using single crystal X-ray diffraction. • The Fe moments in Hf{sub 3}Fe{sub 4}Sn{sub 4} display AFM order below T{sub N}=373 K. • The Fe moments in Hf{sub 9}Fe{sub 4−x}Sn{sub 10+x} display AFM order below T{sub N}=46 K.

Synthesis and crystal structure of Fe[(Te1.5Se0.5)O5]Cl, the first iron compound with selenate(IV) and tellurate(IV) groups

Science.gov (United States)

Akhrorov, Akhmad Yu; Kuznetsova, Elena S.; Aksenov, Sergey M.; Berdonosov, Peter S.; Kuznetsov, Alexey N.; Dolgikh, Valery A.

2017-12-01

During the search for selenium analogues of FeTe2O5Cl, the new iron (III) tellurate(IV) selenate(IV) chloride with the composition Fe[(Te1.5Se0.5)O5]Cl was synthesized by chemical vapor transport (CVT) reaction and characterized by TGA-, EDX-,SCXRD-analysis, as well as IR and Raman spectroscopy. It was found that Fe[(Te1.5Se0.5)O5]Cl crystallizes in the monoclinic space group P21/c with unitcell parameters a = 5.183(3) Å, b = 15.521(9) Å, c = 7.128(5) Å and β = 107.16(1)°. The crystal structure of Fe[(Te1.5Se0.5)O5]Cl represents a new structure type and contains electroneutral heteropolyhedral layers formed by dimers of the [FeO5Cl]8- octahedra, linked via common O-O edges, and mixed [Te3SeO10]4- tetramers. Adjacent layers are stacked along the b axis and linked by weak residual bonds. The new compound is stable up to 420 °C. DFT calculations predict Fe[(Te1.5Se0.5)O5]Cl to be a wide-gap semiconductor with the band gap of ca. 2.7 eV.

Hydrogen production by steam reforming of bio-oil aqueous fraction over Co-Fe/ZSM-5

Science.gov (United States)

Chen, Mingqiang; Wang, Yishuang; Liang, Tian; Yang, Zhonglian

2018-02-01

A series of Co-Fe/ZSM-5 catalysts were prepared by impregnation method and their catalytic performance under steam reforming bio-oil aqueous fraction (SRBAF). The as-prepared catalysts were characterized by XRD, BET, and SEM. The characterization results revealed the Co-Fe alloy phase was formed in Co0.5Fe0.5/ZSM-5 catalyst, and this catalyst exhibited unique pore volume (0.28 cm3/g) and pore size (8.4 nm). The results of experiment demonstrated the addition of Fe species could significantly increase C conversion and H2 yield, and the formation of Co-Fe alloy effectively inhibited methanation reaction and improved water-gas shift (WGS) reaction. The highest H2 yield (81%) and C conversion (85%) was obtained at the following reaction conditions: 2.5 g of C0.5F0.5/Z catalyst, T = 700 °C, S/C = 10-14,.feed flow rate was 10.0 gbio-oil/h, N2 flow rate was 0.16 L/min.

Permittivity and modulus spectroscopic study of BaFe0.5Nb0.5O3 ceramics

Directory of Open Access Journals (Sweden)

Subrat K. Kar

2013-12-01

Full Text Available Ba(Fe0.5Nb0.5O3 (BFN powder was synthesized in single perovskite phase by conventional solid state reaction route and BFN ceramic was obtained by uniaxial pressing and sintering at 1350 °C. Complex immittance like: permittivity and modulus spectroscopic formalism were simultaneously used to explain dielectric behaviour of the ceramics. The activation energy calculated from dielectric relaxation below 100 °C was found to be ~0.19 eV. The activation energy obtained from modulus spectra above 100 °C was ~0.59 eV. The space charge polarization model was used to explain the origin of relaxation and “giant” permittivity of BFN ceramics near room temperature.

Precise measurement of the neutron capture reaction 54Fe(n,γ)55Fe via AMS

International Nuclear Information System (INIS)

Wallner, A; Buczak, K; Forstner, O; Golser, R; Kutschera, W; Lederer, C; Priller, A; Steier, P; Belgya, T; Szentmiklosi, L; Bichler, M; Coquard, L; Dillmann, I; Kaeppeler, F; Mengoni, A; Reifarth, R

2010-01-01

The measurement of cross sections relevant to nuclear astrophysics has become one main research topic at the VERA (Vienna Environmental Research Accelerator) facility. The technique applied, accelerator mass spectrometry (AMS), offers excellent sensitivity for the detection of long-lived radionuclides through ultra-low isotope ratio measurements. We discuss the potential and preliminary results of ongoing precision measurements of neutron-capture cross sections of 54 Fe. Such measurements might help to clarify the recently found discrepancy of s-process nucleosynthesis at lower-mass nuclei (A 55 Fe (t 1/2 = 2.72 yr) was analyzed using AMS. At VERA, detection of 55 Fe was developed with a reproducibility of about 1%, which makes the 54 Fe(n,γ) 55 Fe reaction a precise and unique laboratory measurement, which can serve as a reference to complementary techniques. In this regard a new 55 Fe standard for AMS measurements was produced. The final cross-section data are expected to be accurate to better than 3%. We report a preliminary, however, already significantly improved thermal neutron cross section value of (2.32 ± 0.10) barn, and a value of (6.3 ± 0.6) mbarn for E n = (520 ± 50) keV.

Polyphosphoric acid supported on Ni0.5Zn0.5Fe2O4 nanoparticles as a magnetically-recoverable green catalyst for the synthesis of pyranopyrazoles

Directory of Open Access Journals (Sweden)

Farid Moeinpour

2017-05-01

Full Text Available Polyphosphoric acid supported on silica coated Ni0.5Zn0.5Fe2O4 nanoparticles was found to be magnetically separable, highly efficient, eco-friendly, green and recyclable heterogeneous catalyst. This new catalyst at first was fully characterized by TEM, SEM, FTIR and XRD techniques and then catalytic activity of this catalyst was investigated in the synthesis of 5-cyano-1,4-dihydropyrano[2,3-c]pyrazoles. Also the Ni0.5Zn0.5Fe2O4 magnetic nanoparticle-supported polyphosphoric acid could be reused at least six times without significant loss of activity. It could be recovered easily by applying an external magnet.

Use of Aloe vera shell ash supported Ni0.5Zn0.5Fe2O4 magnetic nanoparticles for removal of Pb (II from aqueous solutions

Directory of Open Access Journals (Sweden)

Samira Namavari

2016-03-01

Full Text Available Background: Lead (Pb is a heavy metal that is widely utilized in industries. It contaminates soil and groundwater. Its non-biodegradability, severe toxicity, carcinogenicity, ability to accumulate in nature and contaminate groundwater and surface water make this toxic heavy metal extremely dangerous to living beings and the environment. Therefore, technical and economic methods of removing Pb are of great importance. This study evaluated the efficiency of Ni0.5Zn0.5Fe2O4 magnetic nanoparticles supported by Aloe vera shell ash in removing Pb from aqueous environments. Methods: The adsorbent was characterized by several methods, including x-ray diffraction (XRD, scanning electron microscopy (SEM, and Fourier transform infrared spectroscopy (FT-IR. Then, the potential of Aloe vera shell ash-supported Ni0.5Zn0.5Fe2O4 magnetic nanoparticles to adsorb Pb (II was investigated. To determine the amount of lead absorbed by this adsorbent, different pHs (2, 4, 5, and 6, adsorbent doses (0.01-0.40 g, Pb concentrations (5, 10, 20, 30, 40, 50, 60, 80, 100, 200, 300, and 600 mg/L, and exposure times (0, 5, 10, 15, 20, 30, 40, 50, and 60 minutes until reaching equilibrium were tested using an atomic absorption spectrometer (Varian-AA240FS. Residual concentrations of Pb were read. Results: The results show that a time of 15 minutes, pH value of 9, and adsorbent dose of 0.2 g are the optimum conditions for Pb (II removal by this adsorption process. Increasing the initial concentration of Pb (II from 5 to 600 mg/L decreased removal efficiency from 98.8% to 73%. The experimental data fit well into the Freundlich isotherm model (R2 = 0.989. Conclusion: Ni0.5Zn0.5Fe2O4 magnetic nanoparticles supported by Aloe vera shell ash comprise a low-cost, simple, and environmentally benign procedure. The maximum monolayer adsorption capacity based on the Langmuir isotherm (R2 = 0.884 is 47.2 mg g-1. The prepared magnetic adsorbent can be well dispersed in aqueous solutions and

Association of a television in the bedroom with increased adiposity gain in a nationally representative sample of children and adolescents.

Science.gov (United States)

Gilbert-Diamond, Diane; Li, Zhigang; Adachi-Mejia, Anna M; McClure, Auden C; Sargent, James D

2014-05-01

Obesity affects health in children and adolescents. Television viewing is an established risk factor for obesity in youth. No prospective study has assessed whether a bedroom television confers an additional risk for obesity in youth. To assess the prospective association between the presence of a bedroom television and change in body mass index (BMI; calculated as weight in kilograms divided by height in meters squared), independent of television viewing, in a nationally representative sample of US children and adolescents. We conducted a random-digit prospective telephone survey that captured children and adolescents from across the United States. Participants included 6522 boys and girls aged 10 to 14 years at baseline who were surveyed via telephone about media risk factors for obesity.Weighted regressions assessed adiposity at 2- and 4-year follow-up, controlling for television and movie viewing, video-game playing, parenting, age, sex, race or ethnicity, household income, and parental educational level. Report of having a television in the bedroom at baseline. Age- and sex-adjusted BMI based on self-report and parent report of weight and height at 2- and 4-year follow-up. Distributions for age, sex, race or ethnicity, and socioeconomic status were similar to census estimates for the US population. Sample weighting methods accounted for higher dropout rates among ethnic minorities and those with lower socioeconomic status. Bedroom televisions were reported by 59.1%of participants at baseline, with boys, ethnic minorities, and those of lower socioeconomic status having significantly higher rates. In multivariate analyses, having a bedroom television was associated with an excess BMI of 0.57 (95%CI, 0.31-0.82) and 0.75 (0.38-1.12) at years 2 and 4, respectively, and a BMI gain of 0.24 (0.02-0.45) from years 2 to 4. Having a bedroom television is associated with weight gain beyond the effect of television viewing time. This association could be the result of

A study on the polymer precursor formation and microstructure evolution of square-shaped (La{sub 0.5}Ba{sub 0.5})(Mn{sub 0.5}Fe{sub 0.5})O{sub 3} ceramic nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Romero, M.; Pardo, H.; Faccio, R.; Suescun, L.; Fernandez-Werner, L.; Mombru, A.W. [Univ. de la Republica, Montevideo (Uruguay). Cryssmat-Lab/Centro NanoMat; Univ. de la Republica, Montevideo (Uruguay). Centro Interdisciplinario de Nanotecnologia, Quimica y Fisica de Materiales; Vazquez, S.; Laborda, I. [Univ. de la Republica, Montevideo (Uruguay). Cryssmat-Lab/Centro NanoMat; Acosta, A. [Univ. de la Republica, Montevideo (Uruguay). Catedra de Quimica Inorganica; Castiglioni, J. [Univ. de la Republica, Montevideo (Uruguay). Catedra de Fisicoquimica

2015-07-01

The polymer precursor formation and the growth mechanism of (La{sub 0.5}Ba{sub 0.5})(Mn{sub 0.5}Fe{sub 0.5})O{sub 3} ceramic nanoparticles have been studied. First, we focused on the influence of isolated metals (La, Ba, Mn, Fe) on the polymer precursor formation by means of Raman, FT-IR, scanning electron microscopy and differential scanning calorimetry, showing that the presence of metal ions, especially iron, increases the oxidation rate of the polymer precursor, while the presence of barium leads to a higher degree of polymerization, preventing partial oxidation of the polymer at low temperatures and allowing the presence of nitrates at the combustion stage. Nevertheless, when all metals are present, the polymer precursor showed a largely homogeneous microstructure with a global average influence from all cations. Finally,we studied the microstructure evolution of nanoparticles obtained after calcination above 700 C. SAXS and TEM analysis suggests that the formation of square-shaped nanoparticles below 900 C and coalescence leads to the formation of larger-sized and round-shaped nanoparticles at 900 C.

A questionnaire survey on sleeping thermal environment and bedroom air conditioning in high-rise residences in Hong Kong

Energy Technology Data Exchange (ETDEWEB)

Lin, Z. [Institute of Heating, Ventilation, Air Conditioning and Gas Engineering, Tongji University, Shanghai (China); Deng, S. [Department of Building Services Engineering, The Hong Kong Polytechnic University, Kowloon, Hong Kong SAR (China)

2006-07-01

This paper reports on the results of a questionnaire survey on sleeping thermal environment and bedroom air conditioning in high-rise residential buildings in Hong Kong. The survey aimed at investigating the current situation of sleeping thermal environment and bedroom air conditioning, in order to gather relevant background information to develop strategies for bedroom air conditioning in the subtropics. It focused on the use patterns and types of bedroom air conditioning systems used, human factors such as the use of bedding and sleep wear during sleep, preference for indoor air temperature settings in bedrooms, ventilation control at nighttime with room air conditioner (RAC) turned on, etc. The results of the survey showed that most of the respondents would prefer a relatively low indoor air temperature at below 24 {sup o}C. Most of the respondents might however not be satisfied with the indoor air quality (IAQ) in bedrooms in Hong Kong. On the other hand, 68% of the respondents did not use any ventilation control intentionally during their sleep with their RACs turned on. A lack of knowledge of the ventilation control devices provided on window type room air conditioners (WRACs) indicated an urgent need for user education. (author)

Remedial Design/Remedial Action Work Plan for Operable Units 6-05 and 10-04, Phase III

Energy Technology Data Exchange (ETDEWEB)

R. P. Wells

2006-09-19

The remedial design/remedial action for Operable Unit 6-05 (Waste Area Group 6) and Operable Unit 10-04 (Waste Area Group 10) - collectively called Operable Unit 10-04 has been divided into four phases. Phase I consists of developing and implementing institutional controls at Operable Unit 10-04 sites and developing and implementing Idaho National Laboratory-wide plans for both institutional controls and ecological monitoring. Phase II will remediate sites contaminated with trinitrotoluene and Royal Demolition Explosive. Phase III will remediate lead contamination at a gun range, and Phase IV will remediate hazards from unexploded ordnance. This Phase III remedial Design/Remedial Action Work Plan addresses the remediation of lead-contaminated soils found at the Security Training Facility (STF)-02 Gun Range located at the Idaho National Laboratory. Remediation of the STF-02 Gun Range will include excavating contaminated soils; physically separating copper and lead for recycling; returning separated soils below the remediation goal to the site; stabilizing contaminated soils, as required, and disposing of the separated soils that exceed the remediation goal; encapsulating and disposing of creosote-contaminated railroad ties and power poles; removing and disposing of the wooden building and asphalt pads found at the STF-02 Gun Range; sampling and analyzing soil to determine the excavation requirements; and when the remediation goals have been met, backfilling and contouring excavated areas and revegetating the affected area.

Magnetic properties of co-modified Fe,N-TiO2 nanocomposites

Directory of Open Access Journals (Sweden)

Zolnierkiewicz Grzegorz

2015-01-01

Full Text Available Iron and nitrogen co-modified titanium dioxide nanocomposites, nFe,N-TiO2 (where n = 1, 5 and 10 wt% of Fe, were investigated by detailed dc susceptibility and magnetization measurements. Different kinds of magnetic interactions were evidenced depending essentially on iron loading of TiO2. The coexistence of superparamagnetic, paramagnetic and ferromagnetic phases was identified at high temperatures. Strong antiferromagnetic interactions were observed below 50 K, where some part of the nanocomposite entered into a long range antiferromagnetic ordering. Antiferromagnetic interactions were attributed to the magnetic agglomerates of iron-based and trivalent iron ions in FeTiO3 phase,whereas ferromagnetic interactions stemmed from the F-center mediated bound magnetic polarons.

Cation distribution in Ni-substituted Mn{sub 0.5}Zn{sub 0.5}Fe{sub 2}O{sub 4} nanoparticles: A Raman, Mössbauer, X-ray diffraction and electron spectroscopy study

Energy Technology Data Exchange (ETDEWEB)

Thota, Suneetha [Microwave Laboratory, Department of Physics, Indian Institute of Technology Delhi, New Delhi 110016 (India); Kashyap, Subhash C., E-mail: skashyap@physics.iitd.ac.in [Microwave Laboratory, Department of Physics, Indian Institute of Technology Delhi, New Delhi 110016 (India); Sharma, Shiv K. [Hawaii Institute of Geophysics and Planetology, University of Hawaii (UH), Honolulu, HI 96822 (United States); Reddy, V.R. [UGC-DAE Consortium for Scientific Research, Khandwa Road, Indore 452017 (India)

2016-04-15

Graphical abstract: - Highlights: • Synthesized Mn{sub 0.5−x}Ni{sub x}Zn{sub 0.5}Fe{sub 2}O{sub 4}, nanoparticles (0.05 ≤ x ≤ 0.45) at low temperature. • Raman studies established that Fe and Zn ions occupy A site in equal fraction. • {sup 57}Fe Mossbauer study revealed that Ni and Mn ions occupy nearly 25% of B sites. • Electron spectroscopy (XPS) confirmed that nearly 25% Fe{sup 3+} dwells at A sites. • Diffraction peak intensity (X-ray) quantified cations distribution at A- and B-sites. - Abstract: In this paper we report the structural, vibration, and electronic-structure parameters (bonding and valence of cations) of single phase cubic mixed spinel nanoparticles of (Zn{sub δ}Mn{sub γ}Fe{sub 1−(γ+δ)})[Ni{sub x}Zn{sub 0.5−δ}Mn{sub 0.5−γ−x}Fe{sub 1+(γ+δ)}]O{sub 4} where x = 0.05–0.45 with an aim to determine cation-distribution i.e. δ and γ in these samples. The Raman spectroscopy has established that only Fe and Zn cations occupy tetrahedral interstitial sites in a FCC anion lattice in nearly equal fraction, and Mössbauer spectra have shown that Fe{sup 3+} cations are present at both, tetrahedral and octahedral interstitial sites and Ni{sup 2+} cations are situated at the octahedral sites in all the substituted samples. The photoelectron spectra also revealed the presence of Fe{sup 3+} cations at both the interstitial sites. The best possible cationic distribution in Ni substituted Mn–Zn ferrites has been estimated by reiteratively calculating the intensity ratios of various pairs of X-ray diffraction peaks and matching with the observed intensity ratios.

Ni{sub 0,5}Zn{sub 0,5}Fe{sub 2}O{sub 3} ferrite synthesized by combustion and Pechini method for use in nanomedicine: methods evaluation; Ferrita Ni{sub 0,5}Zn{sub 0,5}Fe{sub 2}O{sub 3} sintetizada por reacao de combustao e metodo Pechini para uso na nanomedicina: avaliacao dos metodos

Energy Technology Data Exchange (ETDEWEB)

Albuquerque, I.L.T. de; Nascimento, A.L.C.; Costa, A.C.F.M., E-mail: allana.layla@gmail.com [Universidade Federal de Campina Grande (UFCG), PB (Brazil). Unidade Academica de Engenharia de Materiais

2016-07-01

The objective of this work was to synthesize the Ni0.5Zn0.5Fe2O3 ferrite by combustion reaction and Pechini method, and to evaluate structural characteristics and magnetic behavior for its use in nanomedicine. The synthesized ferrite was characterized by DRX, BET, TG and magnetic properties. According to the results of XRD, the Ni{sub 0,5}Zn{sub 0,5}Fe{sub 2}O{sub 3} ferrite synthesized by both methods presented nano crystallite sizes, high crystallinity, surface area, stable at high temperatures and with high saturation magnetization, being higher in the ferrite synthesized by combustion reaction. Both methods produced materials that could be used in nanomedicine.

Fe doping for making resistive GaN layers with low dislocation density; consequence on HEMTs

Energy Technology Data Exchange (ETDEWEB)

Bougrioua, Z.; Lorenzini, P. [CRHEA-CNRS, rue Bernard Gregory, 06560 Valbonne (France); Azize, M. [CRHEA-CNRS, rue Bernard Gregory, 06560 Valbonne (France); LUMILOG, 2720 Chemin St Bernard, 06220 Vallauris (France); Jimenez, A. [E. Politecnica. Universidad de Alcala, 28871 Alcala de Henares (Spain); Brana, A.F.; Munoz, E. [ETSI Telecomunicacion, UPM, 28040 Madrid (Spain); Beaumont, B.; Gibart, P. [LUMILOG, 2720 Chemin St Bernard, 06220 Vallauris (France)

2005-05-01

Highly resistive GaN (>10{sup 8} {omega}{sub {upsilon}}) is grown by MOVPE on sapphire with dislocation density in the range 10{sup 8} to 8 x 10{sup 8} cm{sup -2}, using Fe modulation doping. High mobility 2DEGs are created at AlGaN/GaN:Fe interface for moderate Al composition: 2200 cm{sup 2}/V/s at n{sub s}{proportional_to}7.6 x 10{sup 12} cm{sup -2}. Good DC and RF small signal behaviour could be obtained in HEMTs processed on structures with less dislocated GaN:Fe template: I{sub DS}{sup max}=1.28 A/mm, g{sub m}{sup max} {proportional_to}290 mS/mm and f{sub T} {proportional_to}23 GHz were measured for 0.2 {mu}m transistors. (copyright 2005 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

The Star Wars Kid and the Bedroom Intruder

DEFF Research Database (Denmark)

Christensen, Jørgen Riber

2011-01-01

Jørgen Riber Christensen's article Star Wars Kid and the Bedroom Intruder looks at how people may unexpectedly become icons of the Internet, through a transgression of the private sphere. Surveillance and celebrity is revealed to be bound together with a disciplinary effect, at the same time...

Magnetic properties and local structure of the binary elements codoped Bi1−xLaxFe0.95Mn0.05O3

International Nuclear Information System (INIS)

Li, Yongtao; Zhang, Hongguang; Liu, Hao; Dong, Xueguang; Li, Qi; Chen, Wei; Mao, Weiwei; Li, Xing’ao; Dong, Chenglin; Ren, Shanling

2014-01-01

Highlights: • For the samples Bi 1−x La x (Fe 0.95 Mn 0.05 )O 3 (x = 0, 0.10, 0.15, 0.20), the magnetization changes nonmonotonously with La doping. • Doping La ions affects the local structures of Mn atoms instead of those of Fe atoms by analyzing XAFS data. • The changes of magnetic property result from the changes of the Mn–O bond length. - Abstract: Polycrystalline Bi 1−x La x Fe 0.95 Mn 0.05 O 3 (x = 0, 0.10, 0.15, 0.20) samples were successfully synthesized via sol–gel method. The magnetic properties and local structures of all these samples are investigated. By increasing lanthanum content from 0 to 0.15, the magnetization increases, while it decreases by further La doping. The results of local structures of Fe atoms and Mn atoms which were measured using X-ray absorption fine structure (XAFS) spectra of Fe and Mn K-edge demonstrate that the former has no change, whereas the latter exhibits systematical change of the Mn–O bond length, resulting from doped La ions. We demonstrate that doped La ions affect the local structures of Mn atoms, whereas it has no influence on the local structures of Fe atoms. Finally, to explain the magnetization phenomenon, we analyze interrelation between magnetic property and the Mn–O bond length on the basis of the local structure distortion of the samples

Competing ferromagnetic and anti-ferromagnetic interactions in iron nitride ζ-Fe2N

Science.gov (United States)

Rao, K. Sandeep; Salunke, H. G.

2018-03-01

The paper discusses the magnetic state of zeta phase of iron nitride viz. ζ-Fe2N on the basis of spin polarized first principles electronic structure calculations together with a review of already published data. Results of our first principles study suggest that the ground state of ζ-Fe2N is ferromagnetic (FM) with a magnetic moment of 1.528μB on the Fe site. The FM ground state is lower than the anti-ferromagnetic (AFM) state by 8.44 meV and non-magnetic (NM) state by 191 meV per formula unit. These results are important in view of reports which claim that ζ-Fe2N undergoes an AFM transition below 10 K and others which do not observe any magnetic transition up to 4.2 K. We argue that the experimental results of AFM transition below 10 K are inconclusive and we propose the presence of competing FM and AFM superexchange interactions between Fe sites mediated by nitrogen atoms, which are consistent with Goodenough-Kanamori-Anderson rules. We find that the anti-ferromagnetically coupled Fe sites are outnumbered by ferromagnetically coupled Fe sites leading to a stable FM ground state. A Stoner analysis of the results also supports our claim of a FM ground state.

Spacer layer effect and microstructure on multi-layer [NdFeB/Nb]n films

International Nuclear Information System (INIS)

Tsai, J.-L.; Yao, Y.-D.; Chin, T.-S.; Kronmueller, H.

2002-01-01

Spacer layer effect on multi-layer [NdFeB/Nb] n films has been investigated from the variation of magnetic properties and microstructure of the films. From a HRTEM cross-section view observation, the average grain size of [NdFeB/Nb] n multi-layers was controlled by both annealing temperature and thickness of NdFeB layer. Selected area diffraction pattern indicated that the structure of Nb spacer layer was amorphous. The grain size and coercivity of [NdFeB x /Nb] n films change from 50 nm and 16.7 kOe to 167 nm and 9 kOe for films with x=40 nm, n=10 and x=200 nm, n=2, respectively

Wooden beverage cases cause little damage to bottle caps

Science.gov (United States)

R. Bruce Anderson; William C. Miller

1973-01-01

Wooden beverage cases cause little damage to aluminum resealable caps during distribution. A study at bottling plants and distribution warehouses showed that an average of 1 bottle out of 4,000 has cap damage. Most of the damage was attributed to handling at the warehouse and in transit. Some recommendations are given for improvement of wooden beverage cases to prevent...

Technological quality, mineral profile, and sensory attributes of broiler chicken breasts affected by White Striping and Wooden Breast myopathies.

Science.gov (United States)

Tasoniero, G; Cullere, M; Cecchinato, M; Puolanne, E; Dalle Zotte, A

2016-11-01

The aim of the research was to study the impact of white striping and wooden breast myopathies on the technological quality, mineral, and sensory profile of poultry meat. With this purpose, a total of 138 breasts were selected for a control group with normal breasts (N), a group of breasts characterised by white striping (WS) myopathy, and a group of breasts having both white striping and wooden breast myopathies (WSWB). Data revealed that the simultaneous presence of the two myopathies, with respect to the WS lesion individually considered, had a further detrimental effect on pH (6.04 vs. 5.96; P white striping and wooden breast myopathies. © 2016 Poultry Science Association Inc.

Tuning high frequency magnetic properties and damping of FeGa, FeGaN and FeGaB thin films

Directory of Open Access Journals (Sweden)

Derang Cao

2017-11-01

Full Text Available A series of FeGa, FeGaN and FeGaB films with varied oblique angles were deposited by sputtering method on silicon substrates, respectively. The microstructure, soft magnetism, microwave properties, and damping factor for the films were investigated. The FeGa films showed a poor high frequency magnetic property due to the large stress itself. The grain size of FeGa films was reduced by the additional N element, while the structure of FeGa films was changed from the polycrystalline to amorphous phase by the involved B element. As a result, N content can effectively improve the magnetic softness of FeGa film, but their high frequency magnetic properties were still poor both when the N2/Ar flow rate ratio is 2% and 5% during the deposition. The additional B content significantly led to the excellent magnetic softness and the self-biased ferromagnetic resonance frequency of 1.83 GHz for FeGaB film. The dampings of FeGa films were adjusted by the additional N and B contents from 0.218 to 0.139 and 0.023, respectively. The combination of these properties for FeGa films are helpful for the development of magnetostrictive microwave devices.

Electrical and optical properties of Cr and Fe implanted n-GaN

International Nuclear Information System (INIS)

Polyakov, A.Y.; Smirnov, N.B.; Govorkov, A.V.; Pashkova, N.V.; Shlensky, A.A.; Pearton, S.J.; Overberg, M.E.; Abernathy, C.R.; Zavada, J.M.; Wilson, R.G.

2003-01-01

Deep levels introduced into n-GaN films by Fe and Cr implantation have been studied by means of optical absorption and microcathodoluminescence spectroscopy measurements and by deep level transient spectroscopy, admittance spectroscopy, and capacitance-voltage profiling. The results are compared with previous measurements on Mn and Co implanted GaN. It is shown that the acceptor levels of substitutional Mn, Co, Fe, and Cr in n-GaN are located, respectively, near E v +1.6 eV, E v +1.7 eV, E v +1.8 eV, and E v +2 eV, the trend being similar to that observed in GaAs, GaP, and InP. The Fermi level in the implanted region is pinned near deep electron traps at E c -0.5 eV that are tentatively attributed to complexes between substitutional transition metal ions and native defects such as nitrogen vacancies. It is shown that for all implanted species after 700 deg. C annealing a damaged region with relatively high resistivity is formed down to the depth of about 1 μm much, exceeding the projected range of implanted ions. This region is enriched with radiation-damage-related defects and is most likely formed by outdiffusion of these defects from the implanted region during annealing. The thickness of this damaged region is shown to be the lowest for Cr implantation

Chromatographic determination of Fe chelated by ethylenediamine-N-(o-hydroxyphenylacetic)-N'-(p-hydroxyphenylacetic) acid in commercial EDDHA/Fe3+ fertilizers.

Science.gov (United States)

García-Marco, Sonia; Torreblanca, Ana; Lucena, Juan J

2006-02-22

EDDHA/Fe3+ chelates are the most common fertilizers used to solve Fe chlorosis in established crops. Commercial products contain two regioisomers, ethylenediamine-N,N'-bis(o-hydroxyphenylacetic) acid (o,o-EDDHA)/Fe3+ and ethylenediamine-N-(o-hydroxyphenylacetic)-N'-(p-hydroxyphenylacetic) acid (o,p-EDDHA)/Fe3+. Although several chromatographic methods exist for the determination of Fe3+ chelated by the o,o-EDDHA isomer, no method has been described for the quantification of Fe3+ chelated by o,p-EDDHA. In this work, factors that affect the behavior of o,p-EDDHA/Fe3+ in ion pair chromatography are reviewed: pH, ion pair reagent, and organic modifier. The best chromatographic performance was obtained with an aqueous mobile phase at pH 6.0 containing 35% acetonitrile and 5 mM tetrabutylammonium hydroxide under isocratic elution conditions. This method was applied to the quantification of commercial samples.

Resistencia a la corrosión atmosférica del recubrimiento Zn-10,2% Fe sobre chapa de acero. Comparación con el recubrimiento de zinc

Directory of Open Access Journals (Sweden)

Arnau, G.

1998-05-01

Full Text Available Zn-10.2 % Fe galvanized coating versus hot galvanized coating over carbon steel corrosion performance has been studied. Different periods of atmospheric exposures in various Valencia Community sites, and salt spray accelerated test have been done. Carbon steel test samples have been used simultaneously in order to classify exposure atmosphere corrosivity, and environmental exposure atmosphere characteristics have been analyzed. Corrosion velocity versus environmental parameters has been obtained.

Se estudia el comportamiento a la corrosión atmosférica de un recubrimiento Zn-10,2 % Fe galvanizado en caliente, comparándolo con el comportamiento ofrecido por la chapa galvanizada, habiéndose aplicado ambos recubrimientos sobre chapa de acero de embutición. Se han realizado ensayos de exposición atmosférica en distintas atmósferas de la Comunidad Valenciana y ensayos acelerados de laboratorio en cámara de niebla salina. Se han empleado simultáneamente probetas testigo de acero con el fin de clasificar la corrosividad de las atmósferas, y se han estudiado las características medioambientales de las atmósferas donde se han llevado a cabo los ensayos. Mediante estos estudios se han obtenido las velocidades de corrosión y se han analizado en función de los parámetros ambientales.

Preparation of c-axis perpendicularly oriented ultra-thin L10-FePt films on MgO and VN underlayers

Science.gov (United States)

Futamoto, Masaaki; Shimizu, Tomoki; Ohtake, Mitsuru

2018-05-01

Ultra-thin L10-FePt films of 2 nm average thickness are prepared on (001) oriented MgO and VN underlayers epitaxially grown on base substrate of SrTiO3(001) single crystal. Detailed cross-sectional structures are observed by high-resolution transmission electron microscopy. Continuous L10-FePt(001) thin films with very flat surface are prepared on VN(001) underlayer whereas the films prepared on MgO(001) underlayer consist of isolated L10-FePt(001) crystal islands. Presence of misfit dislocation and lattice bending in L10-FePt material is reducing the effective lattice mismatch with respect to the underlayer to be less than 0.5 %. Formation of very flat and continuous FePt layer on VN underlayer is due to the large surface energy of VN material where de-wetting of FePt material at high temperature annealing process is suppressed under a force balance between the surface and interface energies of FePt and VN materials. An employment of underlayer or substrate material with the lattice constant and the surface energy larger than those of L10-FePt is important for the preparation of very thin FePt epitaxial thin continuous film with the c-axis controlled to be perpendicular to the substrate surface.

Particle morphology and magnetic properties of Ba{sub 0.5}Sr{sub 0.5}Fe{sub 12}O{sub 19} powder calcined conventionally and by microwave heating

Energy Technology Data Exchange (ETDEWEB)

Kanagesan, S., E-mail: kanagu1980@gmail.com [Materials Synthesis and Characterization Laboratory (MSCL), Institute of Advanced Technology (ITMA), Universiti Putra Malaysia, Serdang 43400, Selangor (Malaysia); Hashim, M. [Materials Synthesis and Characterization Laboratory (MSCL), Institute of Advanced Technology (ITMA), Universiti Putra Malaysia, Serdang 43400, Selangor (Malaysia); Physics Department, Faculty of Science, Universiti Putra Malaysia, Serdang 43400, Selangor (Malaysia); Jesurani, S. [Department of Physics, Jeyaraj Annapackium College for Women, Periyakulam 625601, Tamil Nadu (India); Kalaivani, T. [Center for material science and Nano Devices, Department of Physics, SRM University, Kattankulathur 603203, Tamil Nadu (India); Ismail, I.; Shafie, M.S.E. [Materials Synthesis and Characterization Laboratory (MSCL), Institute of Advanced Technology (ITMA), Universiti Putra Malaysia, Serdang 43400, Selangor (Malaysia)

2012-12-05

Highlights: Black-Right-Pointing-Pointer Synthesis of Ba{sub 0.5}Sr{sub 0.5}Fe{sub 12}O{sub 19} by sol-gel technique. Black-Right-Pointing-Pointer Crystallization temperature is reduced to 900 Degree-Sign C due to the addition of D-Fructose. Black-Right-Pointing-Pointer Results of conventional and microwave calcined samples are reported. - Abstract: Barium strontium hexaferrite (Ba{sub 0.5}Sr{sub 0.5}Fe{sub 12}O{sub 19}-BSF) has been prepared by sol-gel process involving use of D-Fructose as a fuel. The prepared precursor was calcined in two different calcinations techniques conventional and microwave furnace. X-ray powder diffraction studies confirmed the formation of single phase Ba{sub 0.5}Sr{sub 0.5}Fe{sub 12}O{sub 19}. HR-SEM results show the morphology of the particles is hexagonal structures in platelet form. The average particle size of conventionally calcined BSF powder is 100-250 nm and that of microwave calcined powder is 30-100 nm. The broad hysteresis loop reveals that powder is well crystallized and exhibits hard magnetic properties.

Thermal stability of ultrasoft Fe-Zr-N films

NARCIS (Netherlands)

Chechenin, NG; van Veen, A; Schut, H; Chezan, AR; Boerma, D; Vystavel, T; De Hosson, JTM

2003-01-01

The thermal stability of nanocrystalline ultrasoft magnetic (Fe98Zr2)(1-x)N-x films with x = 0.10-0.25 was studied using thermal desorption spectrometry, positron beam analysis and high resolution transmission electron microscopy. The results demonstrate that grain growth during the heat treatment

Preparation and properties of [(NdFeB)x/(Nb)z]n multi-layer films

International Nuclear Information System (INIS)

Tsai, J.-L.; Chin, T.-S.; Yao, Y.-D.; Melsheimer, A.; Fisher, S.; Drogen, T.; Kelsch, M.; Kronmueller, H.

2003-01-01

Multi-layer [(NdFeB) x /(Nb) z ] n films with 200 nm≥x≥10 nm, 10 nm≥z≥0, 40≥n≥2, prepared by ion beam sputtering and subsequent annealing, show significantly enhanced coercivity due to the reduced grain size that enhances the anisotropy of individual grains. After annealing at 630 deg. C, some Nd 2 Fe 14 B grains were enriched with Nb and isolated as the thickness of the Nb spacer layer increases. For multi-layer (NdFeB x /Nb z ) n films with 100 nm ≥x≥25 nm, 5 nm≥z≥2 nm, their coercivity and remanence ratio are better than that of a single NdFeB film. Up to 17.8 kOe room temperature coercivity has been obtained for a sample with x=25 nm, z=5 nm and n=16

Enhancement of magnetoresistance by inserting thin NiAl layers at the interfaces in Co{sub 2}FeGa{sub 0.5}Ge{sub 0.5}/Ag/Co{sub 2}FeGa{sub 0.5}Ge{sub 0.5} current-perpendicular-to-plane pseudo spin valves

Energy Technology Data Exchange (ETDEWEB)

Jung, J. W.; Sakuraba, Y., E-mail: Sakuraba.Yuya@nims.go.jp; Sasaki, T. T.; Hono, K. [National Institute for Materials Science (NIMS), Sengen 1-2-1, Tsukuba, Ibaraki 305-0047 (Japan); Miura, Y. [National Institute for Materials Science (NIMS), Sengen 1-2-1, Tsukuba, Ibaraki 305-0047 (Japan); Kyoto Institute of Technology, Electrical Engineering and Electronics, Kyoto 606-8585 (Japan)

2016-03-07

We have investigated the effects of insertion of a thin NiAl layer (≤0.63 nm) into a Co{sub 2}FeGa{sub 0.5}Ge{sub 0.5} (CFGG)/Ag interface on the magnetoresistive properties in CFGG/Ag/CFGG current-perpendicular-to-plane giant magnetoresistance (CPP-GMR) pseudo spin valves (PSVs). First-principles calculations of ballistic transmittance clarified that the interfacial band matching at the (001)-oriented NiAl/CFGG interface is better than that at the (001)-Ag/CFGG interface. The insertion of 0.21-nm-thick NiAl layers at the Co{sub 2}FeGa{sub 0.5}Ge{sub 0.5}/Ag interfaces effectively improved the magnetoresistance (MR) output; the observed average and the highest MR ratio (ΔRA) are 62% (25 mΩ μm{sup 2}) and 77% (31 mΩ μm{sup 2}) at room temperature, respectively, which are much higher than those without NiAl insertion. Microstructural analysis using scanning transmission electron microscopy confirmed the existence of thin NiAl layers at the Ag interfaces with only modest interdiffusion even after annealing at 550 °C. The improvement of the interfacial spin-dependent scattering by very thin NiAl insertion can be a predominant reason for the enhancement of the MR output.

Microstructure and Mechanical Properties of Fe-18Mn-18Cr-0.5N Austenitic Nonmagnetic Stainless Steel in Asymmetric Hot Rolling

Science.gov (United States)

Song, Y. L.; Li, C. S.; Ma, B.; Han, Y. H.

2017-05-01

Asymmetric hot rolling (ASHR) with a mismatch speed ratio of 1.15 in a single pass was applied to Fe-18Mn-18Cr-0.5N steel and was compared with symmetric hot rolling (SHR). The results indicated that a through-thickness microstructure gradient was formed in the plate due to the shear strain (0.36) introduced by ASHR. A fine-grained layer with the average size of 3 μm was achieved at the top surface of ASHR plate, while numerous elongated grains with a few recrystallized grains were presented at the center layer. The texture was distributed randomly at the top surface of ASHR plate, and a weaker intensity of typical hot-rolled texture in austenitic steel was obtained at the center layer of ASHR plate compared to SHR plate. An excellent combination of microhardness, strength and ductility was obtained in the ASHR plate, which was attributed to gradient microstructure induced by ASHR.

Room temperature luminescence and ferromagnetism of AlN:Fe

Energy Technology Data Exchange (ETDEWEB)

Li, H., E-mail: lihui@mail.iee.ac.cn, E-mail: wjwang@aphy.iphy.ac.cn [The Key Laboratory of Solar Thermal Energy and Photovoltaic System, Institute of Electrical engineering, Chinese Academy of Sciences, Beijing 100190 (China); Cai, G. M. [School of Materials Science and Engineering, Central South University, Changsha, Hunan 410083 (China); Wang, W. J., E-mail: lihui@mail.iee.ac.cn, E-mail: wjwang@aphy.iphy.ac.cn [Research and Development Center for Functional Crystals, Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China)

2016-06-15

AlN:Fe polycrystalline powders were synthesized by a modified solid state reaction (MSSR) method. Powder X-ray diffraction and transmission electron microscopy results reveal the single phase nature of the doped samples. In the doped AlN samples, Fe is in Fe{sup 2+} state. Room temperature ferromagnetic behavior is observed in AlN:Fe samples. Two photoluminescence peaks located at about 592 nm (2.09 eV) and 598 nm (2.07 eV) are observed in AlN:Fe samples. Our results suggest that AlN:Fe is a potential material for applications in spintronics and high power laser devices.

Ionic configuration of copper ferrimanganites Cu 0.5Mn xFe 2.5- xO 4

Science.gov (United States)

Lenglet, M.; Kasperek, J.; Hannoyer, B.; Lopitaux, J.; d'Huysser, A.; Tellier, J. C.

1992-06-01

Mössbauer spectrometry, neutron diffraction, XANES, and XPS have led to the determination of the cation distributions of the system Cu 0.5Mn xFe 2.5- xO 4 (0≤ x≤1.5). The three cations are present in both tetrahedral and octahedral sites, and the relative number of Fe ions on A- and B-sites remains nearly constant in the whole range of x. It appears that for x≤0.5 manganese is divalent and copper is in its two oxidation states. For x>0.5 copper and iron are respectively divalent and trivalent; the manganese is in +2 and +3 oxydation states.

Liquid phase interaction in TiC0,5N0,5-TiNi-Mo and TiC0,5N0,5-TiNi-Ti-Mo

International Nuclear Information System (INIS)

Askarova, L.Kh; Grigorov, I.G.; Zajnulin, Yu.G.

1998-01-01

Using the methods of X ray diffraction analysis, electron microscopy and X ray spectrum microanalysis a study was made into specific features of phase and structure formation in alloys TiC 0,5 N 0,5 -TiNi-Mo and TiC 0,5 N 0,5 -TiNi-Mo in the presence of a liquid phase at temperatures of 1380-1600 deg C. It is revealed that the physical and chemical processes taking place during the liquid-phase sintering result in the formation of a three-phase alloy consisting of nonstoichiometric titanium carbonitride TiC 0.5-x N 0.5-x , a molybdenum base solid solution of titanium, nickel and carbon Mo(Ti, Ni, C) and one of two intermetallic compounds, either TiNi or Ni 3 Ti. Metallic element concentration in individual phase constituents of the alloy is determined by means of X ray spectrum microanalysis

Effect of Fe substitution on magnetocaloric effect in La{sub 0.7}Sr{sub 0.3}Mn{sub 1-x}Fe{sub x}O{sub 3} (0.05{<=}x{<=}0.20)

Energy Technology Data Exchange (ETDEWEB)

Barik, S K; Krishnamoorthi, C [Department of Physics and NUS Nanoscience and Nanotechnology Initiative, 2 Science Drive 3, National University of Singapore, Singapore 117542, Singapore. (Singapore); Mahendiran, R [Department of Physics and NUS Nanoscience and Nanotechnology Initiative, 2 Science Drive 3, National University of Singapore, Singapore 117542, Singapore. (Singapore)

2011-04-15

We have studied the effect of Fe substitution on magnetic and magnetocaloric properties in La{sub 0.7}Sr{sub 0.3}Mn{sub 1-x}Fe{sub x}O{sub 3} (x=0.05, 0.07, 0.10, 0.15, and 0.20) over a wide temperature range (T=10-400 K). It is shown that substitution by Fe gradually decreases the ferromagnetic Curie temperature (T{sub C}) and saturation magnetization up to x=0.15 but a dramatic change occurs for x=0.2. The x=0.2 sample can be considered as a phase separated compound in which both short-range ordered ferromagnetic and antiferromagnetic phases coexist. The magnetic entropy change (-{Delta}S{sub m}) was estimated from isothermal magnetization curves and it decreases with increase of Fe content from 4.4 J kg{sup -1} K{sup -1} at 343 K (x=0.05) to 1.3 J kg{sup -1} K{sup -1} at 105 K (x=0.2), under {Delta}H=5 T. The La{sub 0.7}Sr{sub 0.3}Mn{sub 0.93}Fe{sub 0.07}O{sub 3} sample shows negligible hysteresis loss, operating temperature range over 60 K around room temperature with refrigerant capacity of 225 J kg{sup -1}, and magnetic entropy of 4 J kg{sup -1} K{sup -1} which will be an interesting compound for application in room temperature refrigeration. - Research highlights: > We report magnetocaloric effect in La{sub 0.7}Sr{sub 0.3}Mn{sub 1-x}Fe{sub x}O{sub 3} (x=0-0.2). > Magnetic entropy change ({Delta}S{sub m}) decreases with increasing x. > A large {Delta}S{sub m} and refrigeration capacity are found around 300 K in x=0.07.

Evaluations of the 58Fe(n,γ)59Fe, and 54Fe(n,p)54Mn reactions for the ENDF/B-V dosimetry file

International Nuclear Information System (INIS)

Schenter, R.E.; Schmittroth, F.; Mann, F.M.

1979-10-01

A generalized least-squares adjustment procedure was used to evaluate two important dosimetry reactions for the ENDF/B-V files. Calculations for the cross section adjustments were made with the computer code FERRET, where input data included both integral and differential experimental data results. For the 54 Fe reaction, important ratio measurements were renormalized to ENDF/B-V evaluations of 235 U(n,f), 238 U(n,f), and 56 Fe(n,p). A priori curves which are required for the calculations were obtained using Hauser-Feshbach calculations from the codes NCAP ( 58 Fe) and HAUSER-5 ( 54 Fe). Covariance matrices were also calculated and are included in the evaluations. 8 figures, 1 table

Magneto-optical properties BaBi{sub x}La{sub x}Fe{sub 12−2x}O{sub 19} (0.0≤x≤0.5) hexaferrites

Energy Technology Data Exchange (ETDEWEB)

Auwal, I.A. [Department of Chemistry, Fatih University, 34500 B.Çekmece, İstanbul (Turkey); Baykal, A., E-mail: hbaykal@fatih.edu.tr [Department of Chemistry, Fatih University, 34500 B.Çekmece, İstanbul (Turkey); Güner, S. [Department of Physics, Fatih University, 34500 B.Çekmece, İstanbul (Turkey); Sertkol, M. [Department of Physics Engineering, Istanbul Technical University, 34469 Maslak, Istanbul (Turkey); Sözeri, H. [TUBITAK-UME, National Metrology Institute, P.O. Box 54, 41470 Gebze, Kocaeli (Turkey)

2016-07-01

BaBi{sub x}La{sub x}Fe{sub (12−2x)}O{sub 19} (0.0≤x≤0.5) hexaferrites were synthesized by solid state synthesis route and the effects of Bi, La substitutions on structural, magnetic and optical properties were investigated. X-ray powder diffraction, Scanning electron microscopy, Vibrating sample magnetometer, and Percent diffuse reflectance spectroscopy were used to study the physical properties. Room temperature specific magnetization (M–H) curves revealed the ferromagnetic nature of all products. The increasing Bi, La compositions increased the magnetic properties at different magnitudes with respect to undoped BaFe{sub 12}O{sub 19} sample. The maximum values of remnant specific magnetization (M{sub r}=30.3 emu/g), extrapolated specific saturation magnetization (M{sub s}=62.12 emu/g), and magneton number (n{sub B}=16.27) were recorded from BaBi{sub 0.2}La{sub 0.2}Fe{sub 11.4}O{sub 19} hexaferrite. The average crystallite size varies in a range of (37.35–51.36) nm. The coercive field (H{sub c}) of undoped hexaferrites is 1180 Oe and increased to maximum 2320 Oe belonging to BaBi{sub 0.4}La{sub 0.4}Fe{sub 11.2}O{sub 19}. Magnetic anisotropy was confirmed as uniaxial and calculated effective anisotropy constants (K{sub eff}) are between 4.27×10{sup 5} Ergs/g and 5.05×10{sup 5} Ergs/g. The high magnitudes of magnetocrystalline anisotropy (H{sub a}) above than 16,200 Oe revealed that all samples are magnetically hard materials. The Tauc plots were drawn to extrapolate the direct optical energy band gap (E{sub g}) of hexaferrites. The E{sub g} values decreased from 1.76 eV to 1.47 eV with increasing Bi, La compositions. - Highlights: • BaBi{sub x}La{sub x}Fe{sub (12−2x)}O{sub 19} (0.0≤x≤0.5) hexaferrites were synthesized by solid state synthesis route. • The E{sub g} values decreased from 1.76 eV to 1.47 eV with increasing Bi, La compositions. • BaBi{sub xx}La{sub xx}Fe{sub 12-2x}O{sub 19} hexaferrites good candidate for potential applications

Room temperature luminescence and ferromagnetism of AlN:Fe

Directory of Open Access Journals (Sweden)

H. Li

2016-06-01

Full Text Available AlN:Fe polycrystalline powders were synthesized by a modified solid state reaction (MSSR method. Powder X-ray diffraction and transmission electron microscopy results reveal the single phase nature of the doped samples. In the doped AlN samples, Fe is in Fe2+ state. Room temperature ferromagnetic behavior is observed in AlN:Fe samples. Two photoluminescence peaks located at about 592 nm (2.09 eV and 598 nm (2.07 eV are observed in AlN:Fe samples. Our results suggest that AlN:Fe is a potential material for applications in spintronics and high power laser devices.

Phase formation, structure and dielectric properties of ceramics (Na0.5Bi0.5TiO3–(K0.5Na0.5NbO3–BiFeO3

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G. M. Kaleva

2016-03-01

Full Text Available Influence of BiFeO3 (BF on phase formation, unit cell parameters, microstructure, dielectric and ferroelectric properties of solid solutions close to the morphotropic phase boundary in the (Na0.5Bi0.5TiO3–(K0.5Na0.5NbO3 system additionally modified by the low-melting KCl additives has been studied. The formation of pure perovskite structure samples decrease in the unit cell parameters and increase in the TC value stimulated by the BF addition have been revealed. It was proved that modification of compositions by small amounts of the BF and KCl additives leads to improvement of dielectric parameters.

Conducting, magnetic polyaniline/Ba0.25Sr0.75 Fe11(Ni0.5Mn0.5)O19 nanocomposite: Fabrication, characterization and application

International Nuclear Information System (INIS)

Ezzati, S. Noushin; Rabbani, Mahboubeh; Leblanc, Roger M.; Asadi, Ebadullah; Ezzati, S. Mohammad H.; Rahimi, Rahmatollah; Azodi-Deilami, Saman

2015-01-01

In this contribution, Ni/Mn doped Barium Strontium Ferrite nanoparticles (Ba 0.25 Sr 0.75 Fe 11 (Ni 0.5 Mn 0.5 )O 19 ) and conducting polyaniline/Ba 0.25 Sr 0.75 Fe 11 (Ni 0.5 Mn 0.5 )O 19 nanocomposite were fabricated successfully through sol–gel method and in-situ polymerization technique, respectively. Field emission scanning electron microscope (FESEM), Energy-dispersive X-ray spectroscopy analysis (EDX), X-ray powder diffraction (XRD), Mössbauer spectroscopic measurements and Fourier transform infrared spectroscope (FT-IR) analyses were adopted to confirm the composition, morphology and structure of materials. The obtained results revealed the formation of hexagonal M-type rod-shape ferrite with average particle size of about 45 nm (according to XRD data, using Debye–Scherre formula). The saturation magnetization of ferrite nanoparticles and PANI/Ferrite nanocomposite reported 44.03 and 9.85 emu/g, respectively, using vibrant sample magnetometer (VSM). Standard four-point-probe technique was employed to measure the conductivity of samples. Also optical characteristic of samples was examined by means of UV–Vis and Diffuse Reflectance Spectra (DRS) techniques which proved the formation of conducting coating of emeraldine on the surface of magnetic nanoparticles. Also the UV–vis studies indicated that the ferrite nanoparticles have an optical band gap of 1.8 eV while the values of 1.65 and 2.66 eV obtained for PANI/Ferrite nanocomposite. Finally, the microwave absorption properties of prepared nanoferrite and nanocomposite at different thicknesses (2, 3 and 4 mm) were determined at the X-band (8–12 GHz) using vector network analyzer (VNA). In this study, minimum reflection loss of −21.68 dB and maximum available bandwidth of 4.8 GHz were obtained for PANI/Ferrite (20 wt% ferrite) at the frequency of 10.6 GHz. The results suggested the fabricated nanocomposite could be a suitable candidate for decreasing radar signature. - Highlights: • Polyaniline

Enzyme mimics of spinel-type CoxNi1−xFe2O4 magnetic nanomaterial for eletroctrocatalytic oxidation of hydrogen peroxide

International Nuclear Information System (INIS)

Luo, Liqiang; Zhang, Yuting; Li, Fang; Si, Xiaojing; Ding, Yaping; Deng, Dongmei; Wang, Tianlin

2013-01-01

Graphical abstract: -- Highlights: •Spinel-type Co x Ni 1−x Fe 2 O 4 (x = 0, 0.2, 0.4, 0.5, 0.6, 0.8, 1.0) were synthesized. •Co x Ni 1−x Fe 2 O 4 were first employed as novel enzyme mimic sensing materials of H 2 O 2 . •Co 0.5 Ni 0.5 Fe 2 O 4 /CPE showed excellent electrocatalytic activity to H 2 O 2 . •Co 0.5 Ni 0.5 Fe 2 O 4 /CPE was successfully applied to determine H 2 O 2 in toothpastes. -- Abstract: A series of spinel-type Co x Ni 1−x Fe 2 O 4 (x = 0, 0.2, 0.4, 0.5, 0.6, 0.8, 1.0) magnetic nanomaterials were solvothermally synthesized as enzyme mimics for the eletroctrocatalytic oxidation of H 2 O 2 . X-ray diffraction and scanning electron microscope were employed to characterize the composition, structure and morphology of the material. The electrochemical properties of spinel-type Co x Ni 1−x Fe 2 O 4 with different (Co/Ni) molar ratio toward H 2 O 2 oxidation were investigated, and the results demonstrated that Co 0.5 Ni 0.5 Fe 2 O 4 modified carbon paste electrode (Co 0.5 Ni 0.5 Fe 2 O 4 /CPE) possessed the best electrocatalytic activity for H 2 O 2 oxidation. Under optimum conditions, the calibration curve for H 2 O 2 determination on Co 0.5 Ni 0.5 Fe 2 O 4 /CPE was linear in a wide range of 1.0 × 10 −8 –1.0 × 10 −3 M with low detection limit of 3.0 × 10 −9 M (S/N = 3). The proposed Co 0.5 Ni 0.5 Fe 2 O 4 /CPE was also applied to the determination of H 2 O 2 in commercial toothpastes with satisfactory results, indicating that Co x Ni 1−x Fe 2 O 4 is a promising hydrogen peroxidase mimics for the detection of H 2 O 2

Phosphate removal from aqueous solutions using polyaniline/ Ni 0.5 Zn 0.5 Fe 2 O 4 magnetic nanocomposite

Directory of Open Access Journals (Sweden)

Mohammad Hossein Tarmahi

2017-05-01

Full Text Available Background: Phosphorus is an indispensable element for the growth of animals and plants. There are several environmental problems related to phosphate; therefore, the technical and economic methods of removing phosphate are of great importance. This study evaluated the efficiency of polyaniline/ Ni0.5Zn0.5Fe2O4 magnetic nanocomposite in removing phosphate from aqueous environments. Methods: The adsorbent was characterized by several methods, including X-ray diffraction (XRD, scanning electron microscopy (SEM, vibrating sample magnetometer (VSM, and Fourier transform infrared (FT-IR spectroscopy. Then, the potential of the adsorbentto adsorb phosphate was investigated. The effects of the parameters of contact time (5-60 minutes, pH (3-9, adsorbent dosage (0.05-0.6 g, and initial phosphate concentration (2-100 mg/L on the phosphate removal yield were studied. All phosphate ion concentrations were measured using the ammonium molybdate spectrophotometric method. Results: The results showed that a time of 30 minutes, pH of 5, and adsorbent dose of 0.4 g were the optimum conditions for phosphate removal through adsorption. Increasing the initial concentration of phosphate from 2 to 100 mg/L decreased the removal efficiency from 90.3% to 32%. The experimental data was fitted well with the Freundlich isotherm model (R2 = 0.997. Conclusion: Polyaniline/Ni0.5Zn0.5Fe2O4 magnetic nanocomposite removes phosphate from aqueous solutions with a simple and environmentally benign procedure. The maximum adsorption capacity based on Langmuir isotherm (R2 = 0.931 is 85.4 mg/g. This magnetic nanocomposite is applicable in managing water resource pollution caused by phosphate ions.

46 CFR 61.05-10 - Boilers in service.

Science.gov (United States)

2010-10-01

... 46 Shipping 2 2010-10-01 2010-10-01 false Boilers in service. 61.05-10 Section 61.05-10 Shipping... INSPECTIONS Tests and Inspections of Boilers § 61.05-10 Boilers in service. (a) Each boiler, including superheater, reheater, economizer, auxiliary boiler, low-pressure heating boiler, and unfired steam boiler...

Structure and magnetic properties of L10-FePt thin films on TiN/RuAl underlayers

International Nuclear Information System (INIS)

Yang En; Ratanaphan, Sutatch; Zhu Jiangang; Laughlin, David E.

2011-01-01

Highly ordered L1 0 FePt-oxide thin films with small grains were prepared by using a RuAl layer as a grain size defining seed layer along with a TiN barrier layer. Different HAMR (Heat Assisted Magnetic Recording) favorable underlayers were studied to encourage perpendicular texture and preferred microstructure. It was found that the epitaxial and small grain growth from the RuAl/TiN underlayer results in small and uniform grains in the FePt layer with perpendicular texture. By introducing the grain size defining underlayers, the FePt grain size can be reduced from 30 to 6 nm with the same volume fraction (9%) of SiO 2 in the film, excellent perpendicular texture, and very high order parameter at 520 deg. C.

Corrosion characteristics of the Sm2(Fe0.9Co0.1)17N2.9 magnets stabilized by zinc-coating

International Nuclear Information System (INIS)

Arlot, R.; Machida, K.; Adachi, G.; Rango, P. de; Fruchart, D.

1998-01-01

The effect of powder particle size and of zinc coatings ( 2 (Fe 0.9 Co 0.1 ) 17 N 2.9 magnets has been investigated and compared to those obtained for Sm 2 Fe 17 N 3 and Nd 2 Fe 14 B magnets. Potentiokinetic polarisation behaviour in 0.5 N H 2 SO 4 and in Ringer's solution was studied. It was found that in 0.5 N H 2 SO 4 solution, the corrosion resistance is very weak, whereas in Ringer's solution, Zn coating and epoxy embedding provided a very efficient protection to the magnet. This result is quite unexpected as regarding the very weak amount of Zn (0.73 wt%) and epoxy (2.5-5 wt%) used to stabilize those very reactive ground powders which easily burn in air. Also, we characterized the magnetic properties of severely corroded magnets. (orig.)

Coexistence of room temperature ferroelectricity and ferrimagnetism in multiferroic BiFeO3-Bi0.5Na0.5TiO3 solid solution

International Nuclear Information System (INIS)

Tian, Z.M.; Wang, C.H.; Yuan, S.L.; Wu, M.S.; Ma, Z.Z.; Duan, H.N.; Chen, L.

2011-01-01

Highlights: → In this study, the coexistence of ferroelectrics and ferrimagnetism have been observed at room temperature for the (1 - x)BiFeO 3 -xBi 0.5 Na 0.5 TiO 3 (x = 0.37) solid solutions. → X-ray diffraction and Raman spectroscopy measurements show a single-phase perovskite structure with no impurities identified. → A magnetic transition from paramagnetic (PM) to ferrimagnetic (Ferri) ordering is observed for the solution with Curie temperature T C ∼ 330 K. - Abstract: The structure, ferroelectric and magnetic properties of (1 - x)BiFeO 3 -xBi 0.5 Na 0.5 TiO 3 (x = 0.37) solid solution fabricated by a sol-gel method have been investigated. X-ray diffraction and Raman spectroscopy measurements show a single-phase perovskite structure with no impurities identified. Compared with pure BiFeO 3 , the coexistence of ferroelectricity and ferrimagnetism have been observed at room temperature for the solution with remnant polarization P r = 1.41 μC/cm 2 and remnant magnetization M r = 0.054 emu/g. Importantly, a magnetic transition from ferrimagnetic (FM) ordering to paramagnetic (PM) state is observed, with Curie temperature T C ∼ 330 K, being explained in terms of the suppression of cycloid spin configuration by the structural distortion.

Structure refinement of Ba{sub 0.5}Sr{sub 0.5}Co{sub 0.8}Fe{sub 0.2}O{sub 3-d} as cathode materials for intermediate temperature solid oxide fuel cells (IT-SOFC)

Energy Technology Data Exchange (ETDEWEB)

Zakaria, Nurhamidah, E-mail: nurhamidahzakaria@yahoo.com; Idris, Mohd Sobri, E-mail: sobri@unimap.edu.my [Centre of Excellence for Frontier Materials Research, School of Materials Engineering, Universiti Malaysia Perlis (UniMAP), Taman Muhibbah, Jejawi 02600, Arau, Perlis (Malaysia); Osman, Rozana A. M., E-mail: rozana@unimap.edu.my [School of Microelectronics Engineering, Universiti Malaysia Perlis (UniMAP), Pauh Putra, 02600, Arau, Perlis (Malaysia)

2016-07-19

Ba{sub 0.5}Sr{sub 0.5}Co{sub 0.8}Fe{sub 0.2}O{sub 3-δ} was successfully prepared using modified solid-state synthesis routes. The lowest temperature to obtained single phase of Ba{sub 0.5}Sr{sub 0.5}Co{sub 0.8}Fe{sub 0.2}O{sub 3-δ} is about 900°C for 15 hours. Longer period of time are required compared to only 5 hours at 950°C as established in literatures. The X-ray Diffraction (XRD) data confirmed that Ba{sub 0.5}Sr{sub 0.5}Co{sub 0.8}Fe{sub 0.2}O{sub 3-δ} is formed a cubic perovskite with the space group of Pm-3m. The lattice parameters of Ba{sub 0.5}Sr{sub 0.5}Co{sub 0.8}Fe{sub 0.2}O{sub 3-δ} are a = 3.990 (1) Å and unit cell volume is V = 63.5 (1) Å{sup 3}. The Rietveld refinement of XRD data revealed that the crystal structure of Ba{sub 0.5}Sr{sub 0.5}Co{sub 0.8}Fe{sub 0.2}O{sub 3-δ} slightly changes as a function of temperature.

Investigation of structural and magnetic properties of Ni0.5Zn0.5Fe2O4 nano powders prepared by self combustion method

International Nuclear Information System (INIS)

Sudheesh, V.D.; Nehra, J.; Vinesh, A.; Sebastian, V.; Lakshmi, N.; Dutta, Dimple P.; Reddy, V.R.; Venugopalan, K.; Gupta, Ajay

2013-01-01

Graphical abstract: Display Omitted Highlights: ► Ni 0.5 Zn 0.5 Fe 2 O 4 prepared by self combustion with uniform/nonuniform heating. ► Characterized using TEM, XRD, in-field Mössbauer and DC magnetometry. ► Leads to bimodal (S1) and very narrow size distribution (S2) type nano samples. ► S1 has magnetic properties of bulk Ni 0.5 Zn 0.5 Fe 2 O 4 . ► Although very even sized, S2 large magnetic anisotropy distribution. -- Abstract: Nano powders of Ni 0.5 Zn 0.5 Fe 2 O 4 have been synthesized by the self-combustion method at a relatively low temperature of 473 K under conditions of non-uniform and uniform heating. Rietveld fitting of X-ray diffractograms confirm the formation of the pure spinel phase in both samples. Transmission electron microscopy indicates that the sample prepared under non-uniform heating has a bimodal particle size distribution (average values 16 nm and 6 nm) while the one prepared under uniform heating has a very narrow particle size distribution (average size 4 nm). Low temperature, in-field Mössbauer spectroscopic studies clearly show surface spin contributions. The hyperfine fields and Curie temperature of the non-uniformly heated sample are in good agreement with those reported for the corresponding bulk samples. Despite having a very narrow particle size distribution, the uniformly heated sample has a large anisotropy distribution which is evident in the broad transition visible in the temperature dependent magnetization curve. It is also corroborated by the fact that the experimental magnetization curve at room temperature requires two Langevin functions for satisfactory reproduction.

Microstructural and magnetic study of ferrites Ni{sub 0,5}Zn{sub 0,5}Fe{sub 2}O{sub 4} sintered by microwave energy; Estudo microestrutral e magnetico de ferritas Ni{sub 0,5}Zn{sub 0,5}Fe{sub 2}O{sub 4} sinterizadas por energia de micro-ondas

Energy Technology Data Exchange (ETDEWEB)

Diniz, V.C.S.; Costa, A.C.F.M., E-mail: veronicacristhina@hotmail.com [Universidade Federal de Campina Grande (UFCG), PB (Brazil). Programa de Pos-Graduacao em Ciencias e Engenharia de Materiais; Kiminami, R.H.G.A. [Universidade Federal de Sao Carlos (UFSCar), SP (Brazil). Departamento de Engenharia de Materiais; Cornejo, D.R. [Universidade de Sao Paulo (USP), SP (Brazil). Instituto de Fisica

2014-07-01

The study of the processing of Ni-Zn ferrite is of extreme importance to improve its magnetic properties, as they are directly influenced by the final microstructure of the material. This study evaluated the influence of exposure time in the sintering of Ni-Zn ferrite phase by microwave energy, and its subsequent microstructural characterization, and magnetic. The samples of Ni-Zn ferrite were sintered using microwave energy at a temperature of 1200 °C and an exposure time of 10, 20 and 30 minutes, respectively. Then were characterized by X-ray diffraction spectroscopy, scanning electron microscopy and magnetic measurements. With the results, it was observed that all samples obtained from the formation Ni{sub 0,5}Zn{sub 0,5}Fe{sub 2}O{sub 4} phase with all high intensity peaks. It was possible to obtain a nanostructure with maximum saturation magnetization of 71 emu / g for the sample sintered in longer exposure time. (author)

Tris(1,10-phenanthroline-κ2N,N′iron(II bis[(1,10-phenanthroline-κ2N,N′tetrakis(thiocyanato-κNchromate(III] acetonitrile trisolvate monohydrate

Directory of Open Access Journals (Sweden)

Volodymyr V. Bon

2012-05-01

Full Text Available Single crystals of the title heterometallic compound, [Fe(C12H8N23][Cr(NCS4(C12H8N2]2·3CH3CN·H2O or [Fe(Cphen3][Cr(NCS4(phen]2·3CH3CN·H2O, were prepared using the one-pot open-air reaction of iron powder, Reineckes salt and 1,10-phenanthroline (phen in acetonitrile. The asymetric unit consists of an [Fe(phen3]2+ cation, two [Cr(phen(NCS4]− anions, three acetonitrile solvent molecules and a water molecule. The Fe and Cr atoms both show a slightly distorted octahedral FeN6 and CrN6 coordination geometry with adjacent angles in the range 79.67 (12–95.21 (12°. No classical hydrogen bonding involving the water molecule is observed.

Structures, stability, magnetic moments and growth strategies of the Fe_nN (n = 1–7) clusters: All-electron density functional theory calculations

International Nuclear Information System (INIS)

Li, Zhi; Zhao, Zhen

2017-01-01

The geometries, electronic properties, magnetic moments and growth strategies of the Fe_nN (n = 1–7) clusters are investigated using all-electron density functional theory. The results show that N doping significantly distorts the Fe_n clusters. Fe_4N and Fe_6N clusters are more stable structures than other considered Fe_nN clusters. Local peaks of HOMO-LUMO gap curve are found at n = 3, 7, implying that the chemical stability of the Fe_3N and Fe_7N clusters is higher. Fe_2N, Fe_4N and Fe_6N clusters have larger magnetic moments compared to other considered Fe_nN (n = 1–7) clusters. It can be seen that the Fe_5 clusters are easier to adsorb a Fe atom while the Fe_4 clusters are easier to adsorb a N atom. The considered Fe_mN clusters prefer to adsorb a Fe atom and larger Fe_mN clusters are easier to grow. - Highlights: • The structural stability of the Fe_4N and Fe_6N clusters is higher. • The chemical stability of the Fe_3N and Fe_7N clusters is higher. • Fe_5 clusters are easier to adsorb a Fe atom while Fe_4 clusters are easier to adsorb a N atom. • Fe_nN clusters prefer to adsorb a Fe atom.

Estimation of historical earthquake intensities and intensity-PGA relationship for wooden house damages

International Nuclear Information System (INIS)

Choi, In-Kil; Seo, Jeong-Moon

2002-01-01

A series of tests and dynamic analyses on Korean traditional wooden houses was performed for the intensity estimation of the typical large historical earthquake records. Static and cyclic lateral load tests on the wooden frames were performed to assess the lateral load capacity of wooden frames. The shaking table tests on two 1:4 scaled models of a Korean ancient commoner's house made of fresh pine lumber were performed. Typical earthquake time histories recorded on soil and rock sites were used as input for the tests. The prototypical wooden house was analyzed for multiple time histories which match Ohsaki's ground response spectra. Seismic analyses comprise the aging of lumber and different soil condition. The relationship between the earthquake intensity and the peak ground acceleration (PGA) is proposed for the wooden house damages based on the results of this study. The intensity of major Korean historical earthquake records related with house collapses was quantitatively estimated to be MM VIII

Photoexcited carrier trapping and recombination at Fe centers in GaN

International Nuclear Information System (INIS)

Uždavinys, T. K.; Marcinkevičius, S.; Leach, J. H.; Evans, K. R.; Look, D. C.

2016-01-01

Fe doped GaN was studied by time-resolved photoluminescence (PL) spectroscopy. The shape of PL transients at different temperatures and excitation powers allowed discrimination between electron and hole capture to Fe"3"+ and Fe"2"+ centers, respectively. Analysis of the internal structure of Fe ions and intra-ion relaxation rates suggests that for high repetition rates of photoexciting laser pulses the electron and hole trapping takes place in the excited state rather than the ground state of Fe ions. Hence, the estimated electron and hole capture coefficients of 5.5 × 10"−"8 cm"3/s and 1.8 × 10"−"8 cm"3/s should be attributed to excited Fe"3"+ and Fe"2"+ states. The difference in electron capture rates determined for high (MHz) and low (Hz) (Fang et al., Appl. Phys. Lett. 107, 051901 (2015)) pulse repetition rates may be assigned to the different Fe states participating in the carrier capture. A weak temperature dependence of the electron trapping rate shows that the potential barrier for the multiphonon electron capture is small. A spectral feature observed at ∼420 nm is assigned to the radiative recombination of an electron in the ground Fe"2"+ state and a bound hole.

Hyperfine fields of Fe in Nd2Fe14BandSm2Fe17N3

Science.gov (United States)

Akai, Hisazumi; Ogura, Masako

2015-03-01

High saturation magnetization of rare-earth magnets originates from Fe and the strong magnetic anisotropy stems from f-states of rare-earth elements such as Nd and Sm. Therefore the hyperfine fields of both Fe and rare-earth provide us with important pieces of information: Fe NMR enable us to detect site dependence of the local magnetic moment and magnetic anisotropy (Fe sites also contribute to the magnetic anisotropy) while rare-earth NQR directly give the information of electric field gradients (EFG) that are related to the shape of the f-electron cloud as well as the EFG produced by ligands. In this study we focus on the hyperfine fields of materials used as permanent magnets, Nd2Fe14BandSm2Fe17N3 from theoretical points of view. The detailed electronic structure together with the hyperfine interactions are discussed on the basis of the first-principles calculation. In particular, the relations between the observed hyperfine fields and the magnetic properties are studies in detail. The effects of doping of those materials by other elements such as Dy and the effects of N adding in Sm2Fe17N3 will be discussed. This work was supported by Elements Strategy Initiative Center for Magnetic Materials Project, the Ministry of Education, Culture, Sports, Science and Technology, Japan.

Microstructural analysis nanoferritas Mn_0_,_5Zn_0_,_5Fe_2O_4 e Mn_0_,_6_5Zn_0_,_3_5Fe_2O_4 synthesized by combustion reaction

International Nuclear Information System (INIS)

Diniz, V.C.S.; Figueiredo, A.R.; Costa Junior, A.D.S.; Diniz, H.M.; Vieira, D.A.; Costa, A.C.F.M.

2014-01-01

The MnZn ferrites are ferrimagnetic materials that have been studied and used in various technological fields. In this work investigated the microstructural characteristics of ferrites and Mn_0_,_5Zn_0_,_5Fe_2O_4 Mn_0_,_6_5Zn_0_,_3_5Fe_2O_4 synthesized by combustion reaction in 200g scale production. The samples were characterized by XRD, crystallinity, crystallite size, X-ray fluorescence and scanning electron microscopy. Given the results it was observed that for both samples the synthesis combustion reaction was efficient for the production of single-phase ferrites with high crystallinity. With respect to the analysis of X-ray fluorescence was noted that the experimental values composition were consistent with the theoretical values calculated for both samples. Regarding morphology for both samples, the formation of the porous powders with feature consisting of dense clumps in the form of irregular foam was observed. (author)

Microsphere LiFe{sub 0.5}Mn{sub 0.5}PO{sub 4}/C composite as high rate and long-life cathode material for lithium-ion battery

Energy Technology Data Exchange (ETDEWEB)

Yang, Chun-Chen, E-mail: ccyang@mail.mcut.edu.tw [Department of Chemical Engineering, Ming Chi University of Technology, New Taipei City 243, Taiwan, ROC (China); Battery Research Center of Green Energy, Ming Chi University of Technology, New Taipei City 243, Taiwan, ROC (China); Chen, Wei-Houng [Department of Chemical Engineering, Ming Chi University of Technology, New Taipei City 243, Taiwan, ROC (China)

2016-04-15

LiFe{sub 0.5}Mn{sub 0.5}PO{sub 4}/C composite material (denoted as SP-LFMP/C) with macro/nano hierarchical porous structure by adding the composite carbon source (i.e., 100 nm polystyrene sphere and 300 nm carbon sphere) is fabricated via a spray dry process. The SP-LFMP/C composite exhibits a 3D hierarchical structure with a high surface area (34.63 m{sup 2} g{sup −1}) and a wide pore size distribution (2–100 nm). The characteristic properties of the samples are examined using X-ray diffraction, micro-Raman spectroscopy, scanning electron microscopy, high-resolution transmission electron microscopy, electrochemical impedance spectroscopy, and galvanostatic charge–discharge tests. The SP-LFMP/C composite achieves discharge capacities of 161, 160, 157, 146, 137, and 115 mAh g{sup −1} at 0.2, 0.5, 1, 3, 5, and 10 C, respectively. Moreover, the SP-LFMP/C material also exhibits excellent cycling performance and stability at 55 °C during the 300 cycle test. These results indicate that the SP-LFMP/C cathode material is an excellent candidate for application in high-energy Li-ion batteries. - Highlights: • A microsphere LiFe{sub 0.5}Mn{sub 0.5}PO{sub 4}/C composite is prepared by a spray drying process. • The composite material shows a mesoporous 3D structure with a high surface area. • The SP-LFMP composite exhibits excellent high rate capability. • The SP-LFMP/C composite shows much higher tap density of 1.33 g cm{sup −3}.

Oxygen- and hydrogen-permeation measurements on-mixed conducting SrFeCo{sub 0.5}O{sub y} ceramic membrane material

Energy Technology Data Exchange (ETDEWEB)

Serra, E.; Casagrande, E.; La Barbera, A. [ENEA UTS MAT, CR Casaccia, 00060 S.M. di Galeria, Roma (Italy); Alvisi, M. [ENEA UTS MAT, CR Brindisi, 72100 Brindisi (Italy); Bezzi, G.; Mingazzini, C. [ENEA UTS MAT, CR Faenza, 48018 Faenza (Italy)

2008-02-15

The SrFeCo{sub 0.5}O{sub y} system combines high electronic/ionic conductivity with appreciable oxygen permeability at elevated temperatures. This system has potential use in high-temperature electrochemical applications such as solid oxide fuel cells, batteries, sensors, and oxygen separation membranes. Dense ceramic membranes of SrFeCo{sub 0.5}O{sub y} are prepared by pressing a ceramic powder prepared by using a sol-gel combustion technique. Oxygen and hydrogen permeation at high temperature on this material are studied. Measurements are conducted using a time-dependent permeation method at the temperature in the range of 1073-1273 K with oxygen- and hydrogen-driving pressures in the range (3 x 10{sup 2})-(1 x 10{sup 5}) Pa (300-1000 mbar). The maximum oxygen-permeated flux at 1273 K is 6.5 x 10{sup -3} mol m{sup -2} s{sup -1}. The activation energies for the O{sub 2}-permeation fluxes and diffusivities are 240 and 194 kJ/mol, respectively. Due to the high fragility, the high temperature for the measurements and the high oxygen permeation through such material, a special membrane holder, and compression sealing system have been designed and realized for the permeation apparatus. (author)

A wooden calendar from southeastern Bulgaria

Science.gov (United States)

Koleva, Vesselina; Georgiev, Iliya

Wooden calendars are a specific tool for preserving the church calendar in medieval Europe. The Christian symbols are skillfully interwoven with traditional signs, which mark the days of importance for the economic and ritual life in a year. The archaic method of time reckoning has turned into a tool for disseminating and establishing the Christian festival system, and is one of the proofs of the syncretism between the pagan tradition and the new religious ritualism. Bulgarian Christians used such objects until the beginning of the 20th century. The earliest date fixed on a wooden calendar is 1783. These calendars are also called rabosh in Bulgaria. The calendar presented here is based on the Julian (solar) calendar containing the major fixed feasts of the Orthodox Church. It has not been published so far and is kept in a private collection.

First principles calculations of the magnetic and hyperfine properties of Fe/N/Fe and Fe/O/Fe multilayers in the ground state of cohesive energy

Science.gov (United States)

dos Santos, A. V.; Samudio Pérez, C. A.; Muenchen, D.; Anibele, T. P.

2015-01-01

The ground state properties of Fe/N/Fe and Fe/O/Fe multilayers were investigated using the first principles calculations. The calculations were performed using the Linearized Augmented Plane Wave (LAPW) method implemented in the Wien2k code. A supercell consisting of one layer of nitride (or oxide) between two layers of Fe in the bcc structure was used to model the structure of the multilayer. The research in new materials also stimulated theoretical and experimental studies of iron-based nitrides due to their variety of structural and magnetic properties for the potential applications as in high strength steels and for high corrosion resistance. It is obvious from many reports that magnetic iron nitrides such as γ-Fe4N and α-Fe16N2 have interesting magnetic properties, among these a high magnetisation saturation and a high density crimp. However, although Fe-N films and multilayers have many potential applications, they can be produced in many ways and are being extensively studied from the theoretical point of view there is no detailed knowledge of their electronic structure. Clearly, efforts to understand the influence of the nitrogen atoms on the entire electronic structure are needed as to correctly interpret the observed changes in the magnetic properties when going from Fe-N bulk compounds to multilayer structures. Nevertheless, the N atoms are not solely responsible for electronics alterations in solid compounds. Theoretical results showed that Fe4X bulk compounds, where X is a variable atom with increasing atomic number (Z), the nature of bonding between X and adjacent Fe atoms changes from more covalent to more ionic and the magnetic moments of Fe also increase for Z=7, i.e. N. This is an indicative that atoms with a Z number higher than 7, i.e., O, can produce several new alterations in the entire magnetic properties of Fe multilayers. This paper presents the first results of an ab-initio electronic structure calculations, performed for Fe-N and Fe

Deep conditions of hydrothermalism of dorsal East Pacific at 130N

International Nuclear Information System (INIS)

Boulegue, J.; Jedwab, J.

1985-01-01

Taking advantage of the formation of carbon graphite and Fe-Zn spinels one can compute the conditions of sea water-basalt interaction in deep conditions at 13 0 N E.P.R. One finds: p=260-500 bar, T=440-480 0 C, fO 2 =10 -27 -10sup(-24.5) bar, pH 2 O/pH 2 approximately= 100, fCO 2 /fCO approximately= 600. These conditions lead to a discussion of the possibilities of vaporisation of the hydrothermal fluid and to a discussion of the geochemical behaviour of U and Fe [fr

Synthesis and characterization of Cu0.3Zn0.5Mg0.2Fe2O4 nanoparticles as a magnetic drug delivery system

Science.gov (United States)

Ansari, Mohammad; Bigham, Ashkan; Hassanzadeh-Tabrizi, S. A.; Abbastabar Ahangar, H.

2017-10-01

Mixed spinel ferrite nanoparticles are being applied in biomedical applications due to their biocompatibility, antibacterial activity, particular magnetic and electronic properties with chemical and thermal stabilities. The Cu0.3Zn0.5Mg0.2Fe2O4 nanoparticles are synthesized through the thermal treatment method. Polyvinyl alcohol (PVA) is used as the capping agent to stabilize the particles and prevent their agglomeration. The synthesized nanoparticles are characterized through X-ray diffractometer (XRD), Fourier transform infrared spectroscopy (FTIR), N2 adsorption-desorption, field emission scanning electron microscopy (FESEM), and transmission electron microscope (TEM). The magnetic characterization is made on a vibrating sample magnetometer (VSM), which displayed super-paramagnetic behavior of the synthesized sample. Potential application of the Cu0.3Zn0.5Mg0.2Fe2O4 nanoparticles as a drug delivery agent is assessed in vitro by estimating their release properties. The obtained results indicate that the amount of ibuprofen (IBU) adsorbed into the nanocarrier of Cu0.3Zn0.5Mg0.2Fe2O4 is 104 mg/g and the drug release is sustained up to 72 h.

Coercivity Recovery Effect of Sm-Fe-Cu-Al Alloy on Sm2Fe17N3 Magnet

Science.gov (United States)

Otogawa, Kohei; Asahi, Toru; Jinno, Miho; Yamaguchi, Wataru; Takagi, Kenta; Kwon, Hansang

2018-03-01

The potential of a Sm-Fe-Cu-Al binder for improvement of the magnetic properties of Sm2Fe17N3 was examined. Transmission electron microscope (TEM) observation of a Sm-Fe-Cu-Al alloy-bonded Sm2Fe17N3 magnet which showed high coercivity revealed that the Sm-Fe-Cu-Al alloy had an effect of removing the surface oxide layer of the Sm2 Fe17N3 grains. However, the Sm-Fe-Cu-Al binder was contaminated by carbon and nitrogen, which originated from the organic solvent used as the milling medium during pulverization. To prevent carbon and nitrogen contamination, the Sm-Fe- Cu-Al alloy was added directly on the surface of the Sm2Fe17N3 grains by sputtering. Comparing the recovered coercivity per unit amount of the added binder the uncontaminated binder-coated sample had a higher coercivity recovery effect than the milled binder-added sample. These results suggested that sufficient addition of the contamination-free Sm-Fe-Cu-Al binder has the possibility to reduce the amount of binder necessary to produce a high coercive Sm2Fe17N3 magnet.

Exploring the cost and value of private versus shared bedrooms in nursing homes.

Science.gov (United States)

Calkins, Margaret; Cassella, Christine

2007-04-01

There is debate about the relative merits and costs of private versus shared bedrooms in nursing homes, particularly in light of the current efforts at creating both cost-efficient and person-centered care facilities. The purpose of this project was to explore the extent to which there is evidence-based information that supports the merits of three different bedroom configurations: traditional shared, enhanced shared, and private. We developed a framework of four broad domains that were related to the different bedroom configurations: psychosocial, clinical, operational, and construction or building factors. Within each dimension, we identified individual factors through the literature, interviews, and focus groups, with the goal of determining the breadth, depth, and quality of evidence supporting the benefits of one configuration over another. The vast majority of factors identified in this study, regardless of whether there was solid empirical data, information from the focus groups, or other anecdotal evidence, indicated better outcomes associated with private rooms over shared rooms in nursing homes. Cost estimates suggest that construction cost (plus debt service) differences range from roughly $20,506 per bed for a traditional shared room to $36,515 for a private one, and that such differences are recouped in less than 2 years if beds are occupied, and in less than 3 months if a shared bed remains unoccupied at average private-pay room costs. Despite limited empirical evidence in some areas, this project provides the foundation for an evidence-based life-cycle costing perspective regarding the relative merits of different bedroom configurations.

XAFS Studies of Fe Doped PhTiO3 Nanoparticles

International Nuclear Information System (INIS)

Shibata, Tomohiro; Chattopadhyay, Soma; Lin Bin; Palkar, V. R.

2007-01-01

Fe K and Ti K edge XAFS studies are reported on Fe doped PbTiO3 nanoparticles down to the 10 nm size. Fe forms Fe3+ ions and substitute for Ti4+ ions. For 18 nm nanoparticles, the Fe and Ti environment is found to be quite different. For PbFe0.5Ti0.5O3, locally the structure remains distorted from bulk to 10 nm size although the average structure changes

Intrinsic Properties of Fe-Substituted L1(0) Magnets

Energy Technology Data Exchange (ETDEWEB)

Manchanda, P; Kumar, P; Kashyap, A; Lucis, MJ; Shield, JE; Mubarok, A; Goldstein, JI; Constantinides, S; Barmak, K; Lewis, LH; Sellmyer, DJ; Skomski, R

2013-10-01

First-principle supercell calculations are used to determine how 3d elemental additions, especially Fe additions, modify the magnetization, exchange and anisotropy of L1(0)-ordered ferromagnets. Calculations are performed using the VASP code and partially involve configurational averaging over site disorder. Three isostructural systems are investigated: Fe-Co-Pt, Mn-Al-Fe, and transition metal-doped Fe-Ni. In all three systems the iron strongly influences the magnetic properties of these compounds, but the specific effect depends on the host. In CoPt(Fe) iron enhances the magnetization, with subtle changes in the magnetic moments that depend on the distribution of the Fe and Co atoms. The addition of Fe to MnAl is detrimental to the magnetization, because it creates antiferromagnetic exchange interactions, but it enhances the magnetic anisotropy. The replacement of 50% of Mn by Fe in MnFeAl2 enhances the anisotropy from 1.77 to 2.5 MJ/m(3). Further, the substitution of light 3d elements such as Ti, V, Cr into L1(0)-ordered FeNi is shown to substantially reduce the magnetization.

Structures, stability, magnetic moments and growth strategies of the Fe{sub n}N (n = 1–7) clusters: All-electron density functional theory calculations

Energy Technology Data Exchange (ETDEWEB)

Li, Zhi, E-mail: lizhi81723700@163.com [School of Materials and Metallurgy, University of Science and Technology Liaoning, Anshan, 114051 (China); Zhao, Zhen [School of Chemistry and Life Science, Anshan Normal University, Anshan, 114007 (China)

2017-02-01

The geometries, electronic properties, magnetic moments and growth strategies of the Fe{sub n}N (n = 1–7) clusters are investigated using all-electron density functional theory. The results show that N doping significantly distorts the Fe{sub n} clusters. Fe{sub 4}N and Fe{sub 6}N clusters are more stable structures than other considered Fe{sub n}N clusters. Local peaks of HOMO-LUMO gap curve are found at n = 3, 7, implying that the chemical stability of the Fe{sub 3}N and Fe{sub 7}N clusters is higher. Fe{sub 2}N, Fe{sub 4}N and Fe{sub 6}N clusters have larger magnetic moments compared to other considered Fe{sub n}N (n = 1–7) clusters. It can be seen that the Fe{sub 5} clusters are easier to adsorb a Fe atom while the Fe{sub 4} clusters are easier to adsorb a N atom. The considered Fe{sub m}N clusters prefer to adsorb a Fe atom and larger Fe{sub m}N clusters are easier to grow. - Highlights: • The structural stability of the Fe{sub 4}N and Fe{sub 6}N clusters is higher. • The chemical stability of the Fe{sub 3}N and Fe{sub 7}N clusters is higher. • Fe{sub 5} clusters are easier to adsorb a Fe atom while Fe{sub 4} clusters are easier to adsorb a N atom. • Fe{sub n}N clusters prefer to adsorb a Fe atom.

Microstructures and mechanical properties of heat-treated Al–5.0Cu–0.5Fe squeeze cast alloys with different Mn/Fe ratio

Energy Technology Data Exchange (ETDEWEB)

Zhang, Weiwen, E-mail: mewzhang@scut.edu.cn; Lin, Bo; Fan, Jianlei; Zhang, Datong; Li, Yuanyuan

2013-12-20

The Al–5.0 wt% Cu–0.5 wt% Fe alloys with different Mn/Fe ratio were prepared by squeeze casting. Various test techniques, including tensile test, image analysis, scanning electron microscope (SEM), X-ray diffraction (XRD), electron probe micro-analyzer (EPMA) and transmission electron microscopy (TEM) were used to examine the microstructures and mechanical properties of the alloys in T5 heat-treated condition. The results show that the β-Fe (Al{sub 7}Cu{sub 2}Fe) is stable and its needle-like morphology is maintained after T5 heat treatment. However, the Chinese script Al{sub m}Fe, α-Fe or Al{sub 6}(FeMn) partially transform to a new Chinese script Cu-rich α(CuFe) (Al{sub 7}Cu{sub 2}Fe or Al{sub 7}Cu{sub 2}(FeMn)), which is harmful to the mechanical properties of the alloys due to the decrease of the Cu content in α(Al) matrix. The optimal Mn/Fe ratio is determined by the morphology of Fe-rich intermetallics, volume fraction of θ′ and T (Al{sub 20}Cu{sub 2}Mn{sub 3}), size of α(Al) dendrite and porosity. Excessive Mn/Fe ratio will deteriorate the mechanical properties of the alloys due to the increase of the total amount of porosity and the Fe-rich intermetallics. When the Mn/Fe ratio is 1.6 and 1.2 for the applied pressure of 0 MPa and 75 MPa, respectively, the needle-like β-Fe phase is completely converted to the Chinese script Fe-rich intermetallics. The ultimate tensile strength, yield strength and elongation of the T5 heat-treated alloy with the Mn/Fe ratio of 1.2 and applied pressure of 75 MPa reach 395 MPa, 335 MPa and 14%, respectively.

Microstructures and mechanical properties of heat-treated Al–5.0Cu–0.5Fe squeeze cast alloys with different Mn/Fe ratio

International Nuclear Information System (INIS)

Zhang, Weiwen; Lin, Bo; Fan, Jianlei; Zhang, Datong; Li, Yuanyuan

2013-01-01

The Al–5.0 wt% Cu–0.5 wt% Fe alloys with different Mn/Fe ratio were prepared by squeeze casting. Various test techniques, including tensile test, image analysis, scanning electron microscope (SEM), X-ray diffraction (XRD), electron probe micro-analyzer (EPMA) and transmission electron microscopy (TEM) were used to examine the microstructures and mechanical properties of the alloys in T5 heat-treated condition. The results show that the β-Fe (Al 7 Cu 2 Fe) is stable and its needle-like morphology is maintained after T5 heat treatment. However, the Chinese script Al m Fe, α-Fe or Al 6 (FeMn) partially transform to a new Chinese script Cu-rich α(CuFe) (Al 7 Cu 2 Fe or Al 7 Cu 2 (FeMn)), which is harmful to the mechanical properties of the alloys due to the decrease of the Cu content in α(Al) matrix. The optimal Mn/Fe ratio is determined by the morphology of Fe-rich intermetallics, volume fraction of θ′ and T (Al 20 Cu 2 Mn 3 ), size of α(Al) dendrite and porosity. Excessive Mn/Fe ratio will deteriorate the mechanical properties of the alloys due to the increase of the total amount of porosity and the Fe-rich intermetallics. When the Mn/Fe ratio is 1.6 and 1.2 for the applied pressure of 0 MPa and 75 MPa, respectively, the needle-like β-Fe phase is completely converted to the Chinese script Fe-rich intermetallics. The ultimate tensile strength, yield strength and elongation of the T5 heat-treated alloy with the Mn/Fe ratio of 1.2 and applied pressure of 75 MPa reach 395 MPa, 335 MPa and 14%, respectively

Synthesis of nanocrystalline Zn0.5Mn0.5Fe2O4 via in situ polymerization technique

International Nuclear Information System (INIS)

Liu Xianming; Fu Shaoyun

2007-01-01

Nanocrystalline Zn 0.5 Mn 0.5 Fe 2 O 4 was synthesized through the pyrolysis of polyacrylate salt precursors prepared via in situ polymerization of the metal salts and acrylic acid. The pyrolysis behavior of the polymeric precursors was studied by use of thermal analysis. The as-obtained product was characterized by powder X-ray diffraction (XRD), transmission electron microscope (TEM), electron diffraction (ED) pattern, scanning electron microscopy (SEM) and electron dispersive X-ray (EDX) analysis. The results revealed that the particle size is in the range of 15-25 nm for Zn-Mn ferrites with good crystallinity. Magnetic properties of the sample at 300 K were measured using a vibrating sample magnetometer, which showed that the sample exhibited characteristics of superparamagnetism

Evaluación por rendimiento de 12 genotipos promisorios de fríjol voluble (Phaseolus vulgaris L. tipo Bola roja y Reventón para las zonas frías de Colombia

Directory of Open Access Journals (Sweden)

López Jesús Edgardo

2006-12-01

Full Text Available

10.0pt; font-family: ";Cambria";,";serif";; mso-ascii-theme-font: major-latin; mso-fareast-font-family: Baskerville; mso-hansi-theme-font: major-latin; mso-bidi-font-family: Baskerville;">El fríjol común (10.0pt; font-family: ";Cambria";,";serif";; mso-ascii-theme-font: major-latin; mso-fareast-font-family: Baskerville-Italic; mso-hansi-theme-font: major-latin; mso-bidi-font-family: Baskerville-Italic;">Phaseolus vulgaris 10.0pt; font-family: ";Cambria";,";serif";; mso-ascii-theme-font: major-latin; mso-fareast-font-family: Baskerville; mso-hansi-theme-font: major-latin; mso-bidi-font-family: Baskerville;">L. es un alimento básico en la región Andina por ser una fuente rica en proteína y de bajo costo. La investigación para incrementar rendimientos en esta leguminosa es una opción para mejorar la competitividad en el mercado mundial. El objetivo principal de este trabajo fue evaluar por rendimiento los genotipos promisorios de fríjol voluble, tipos Bola roja y Reventón, para las zonas frías de Colombia mediante el análisis de sendero. Se realizó un diseño de bloques completos al azar con tres réplicas para evaluar 10 genotipos promisorios de fríjol voluble. El análisis de sendero para el rendimiento por planta y las correlaciones entre el rendimiento y sus componentes mostraron que el carácter número de vainas por planta es el de mayor importancia sobre la determinación del rendimiento, en comparación con los caracteres peso de 100 semillas y número de semillas por vaina, tanto en los genotipos de fríjol voluble tipo Bola roja como tipo Reventón. 

New lithium ion batteries exploiting conversion/alloying anode and LiFe0.25Mn0.5Co0.25PO4 olivine cathode

International Nuclear Information System (INIS)

Lecce, Daniele Di; Verrelli, Roberta; Hassoun, Jusef

2016-01-01

Highlights: • New Li-ion batteries are reported. • LiFe 0.25 Mn 0.5 Co 0.25 PO 4 olivine is used as the cathode. • Either Sn-C or Sn-Fe 2 O 3 -C composites are used as anodes. • The electrode/electrolyte interfaces are monitored by EIS. • The systems are considered suitable for energy storage - Abstract: New Li-ion cells are formed by combining a LiFe 0.25 Mn 0.5 Co 0.25 PO 4 olivine cathode either with Sn-Fe 2 O 3 -C or with Sn-C composite anodes. These active materials exhibit electrochemical properties very attractive in view of practical use, including the higher working voltage of the LiFe 0.25 Mn 0.5 Co 0.25 PO 4 cathode with respect to conventional LiFePO 4 , as well as the remarkable capacity and rate capability of Sn-Fe 2 O 3 -C and Sn-C anodes. The stable electrode/electrolyte interfaces, demonstrated by electrochemical impedance spectroscopy, along with proper mass balancing and anode pre-lithiation, allow stable galvanostatic cycling of the full cells. The two batteries, namely Sn-Fe 2 O 3 -C/LiFe 0.25 Mn 0.5 Co 0.25 PO 4 and Sn-C/LiFe 0.25 Mn 0.5 Co 0.25 PO 4 , reversibly operate revealing promising electrochemical features in terms of delivered capacity, working voltage and stability, thus suggesting these electrodes combinations as suitable alternatives for an efficient energy storage.

Phase Transformations and Phase Equilibria in the Fe-N System at Temperatures below 573 K

DEFF Research Database (Denmark)

Malinov, S.; Böttger, A.J.; Mittemeijer, E.J.

2001-01-01

The phase transformations of homogeneous Fe-N alloys of nitrogen contents from 10 to 26 at. pct were investigated by means of X-ray diffraction analysis upon aging in the temperature range from 373 to 473 K. It was found that precipitation of alpha double prime-Fe16N2 below 443 K does not only oc...

Ancient Chemistry "Pharaoh's Snakes" for Efficient Fe-/N-Doped Carbon Electrocatalysts.

Science.gov (United States)

Ren, Guangyuan; Gao, Liangliang; Teng, Chao; Li, Yunan; Yang, Hequn; Shui, Jianglan; Lu, Xianyong; Zhu, Ying; Dai, Liming

2018-04-04

The method of fabricating nonprecious metal electrocatalysts with high activity and durability through a facile and eco-friendly procedure is of great significance to the development of low-cost fuel cells and metal-air batteries. Herein, we present that an ancient chemical reaction of "Pharaoh's snakes" can be a fast and convenient technique to prepare Fe-/N-doped carbon (Fe/N-C) nanosheet/nanotube electrocatalysts with sugar, soda, melamine, and iron nitrate as precursors. The resultant Fe/N-C catalyst has a hierarchically porous structure, a large surface area, and uniformly distributed active sites. The catalyst shows high electrocatalytic activities toward both the oxygen reduction reaction with a half-wave potential of 0.90 V (vs reversible hydrogen electrode) better than that of Pt/C and the oxygen evolution reaction with an overpotential of 0.46 V at the current density of 10 mA cm -2 comparable to that of RuO 2 . The activity and stability of the catalyst are also evaluated in primary and rechargeable Zn-air batteries. In both conditions, three-dimensional Fe/N-C exhibited performances superior to Pt/C. Our work demonstrates a success of utilizing an ancient science to make a state-of-the-art electrocatalyst.

Epitaxial Fe16N2 thin film on nonmagnetic seed layer

Science.gov (United States)

Hang, Xudong; Zhang, Xiaowei; Ma, Bin; Lauter, Valeria; Wang, Jian-Ping

2018-05-01

Metastable α″ -Fe16N2 has attracted much interest as a candidate for rare-earth-free hard magnetic materials. We demonstrate that Fe16N2 thin films were grown epitaxially on Cr seed layers with MgO (001) substrates by facing-target sputtering. Good crystallinity with the epitaxial relation MgO (001 )[110 ] ∥ Cr (001 )[100 ] ∥ Fe16N2 (001 )[100 ] was obtained. The chemical order parameter, which quantifies the degree of N ordering in the Fe16N2 (the N-disordered phase is α' -Fe8N martensite), reaches 0.75 for Cr-seeded samples. Cr has a perfect lattice constant match with Fe16N2, and no noticeable strain can be assigned to Fe16N2. The intrinsic saturation magnetization of this non-strained Fe16N2 thin film at room temperature is determined to be 2.31 T by polarized neutron reflectometry and confirmed with vibrating sample magnetometry. Our work provides a platform to directly study the magnetic properties of high purity Fe16N2 films with a high order parameter.

Structural and optical properties of Mn{sub 0.5}Zn{sub 0.5}Fe{sub 2}O{sub 4} nano ferrites: Effect of sintering temperature

Energy Technology Data Exchange (ETDEWEB)

Thakur, Prashant, E-mail: prashant007thakur@gmail.com; Sharma, Rohit; Sharma, Vineet, E-mail: vineet.sharma@juiit.ac.in; Sharma, Pankaj, E-mail: pankaj.sharma@juit.ac.in

2017-06-01

Mn-Zn ferrites have shown various remarkable applications e.g. in magnetic amplifiers, power transformers and electromagnetic interference etc. due to their high initial permeability. Mn–Zn ferrite powder (Mn{sub 0.5}Zn{sub 0.5}Fe{sub 2}O{sub 4}) has been prepared by the co-precipitation method and subsequently sintered at three different temperatures i.e. 973 K, 1173 K, 1373 K. Optical properties have been correlated with the structural properties. For structural properties X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and Fourier transform infrared spectroscopy (FTIR) have been employed. It has been observed that there is an increase in crystallite size with sintering from 973 K to 1373 K and FTIR confirms the formation of bond between metal ion and oxygen ion at the octahedral site and tetrahedral site. A red shift has been confirmed from UV–visible absorption spectra and photoluminescence spectra have been reported with an increase in sintering temperature. - Graphical abstract: Mn–Zn ferrite powder (Mn{sub 0.5}Zn{sub 0.5}Fe{sub 2}O{sub 4}) has been prepared by the co-precipitation method and subsequently sintered at three different temperatures i.e. 973 K, 1173 K, 1373 K. A red shift has been confirmed from UV–visible absorption spectra and photoluminescence spectra have been reported with an increase in sintering temperature. - Highlights: • Nanoparticles of Mn{sub 0.5}Zn{sub 0.5}Fe{sub 2}O{sub 4} have been prepared by the co-precipitation method. • There is an increase in crystallite size with sintering from 973 K to 1373 K. • A red shift is found in UV–visible and PL spectra with an increase in sintering temperature.

Mechanical behaviour of Br0.5Sr0.5Co0.8Fe0.2O3-δ under uniaxial compression

International Nuclear Information System (INIS)

Araki, Wakako; Malzbender, Jürgen

2013-01-01

The present study reports on the mechanical behaviour of Br 0.5 Sr 0.5 Co 0.8 Fe 0.2 O 3-δ under uniaxial compression at various temperatures. The stress–strain curve at room temperature shows a small but clear creep deformation, along with a hysteresis and a remnant strain, which could be related to a spin transition of cobalt. The hysteresis as well as Young’s modulus decrease with increasing temperature to 473 K, at which temperature the creep behaviour disappears. The material shows conventional high-temperature creep above 673 K

Simultaneous achievement of high dielectric constant and low temperature dependence of capacitance in (111-oriented BaTiO3-Bi(Mg0.5Ti0.5O3-BiFeO3 solid solution thin films

Directory of Open Access Journals (Sweden)

Junichi Kimura

2016-01-01

Full Text Available The temperature dependence of the capacitance of (111c-oriented (0.90–xBaTiO3-0.10Bi(Mg0.5Ti0.5O3-xBiFeO3 solid solution films is investigated. These films are prepared on (111cSrRuO3/(111Pt/TiO2/SiO2/(100Si substrates by the chemical solution deposition technique. All the films have perovskite structures and the crystal symmetry at room temperature varies with increasing x ratio, from pseudocubic when x = 0–0.30 to rhombohedral when x = 0.50–0.90. The pseudocubic phase shows a high relative dielectric constant (εr (ranging between 400 and 560 at room temperature and an operating frequency of 100 kHz and a low temperature dependence of capacitance up to 400°C, while maintaining a dielectric loss (tan δ value of less than 0.2 at 100 kHz. In contrast, εr for the rhombohedral phase increases monotonically with increasing temperature up to 250°C, and increasingly high tan δ values are recorded at higher temperatures. These results indicate that pseudocubic (0.90–xBaTiO3-0.10Bi(Mg0.5Ti0.5O3-xBiFeO3 solid solution films with (111 orientation are suitable candidates for high-temperature capacitor applications.

Evidence for molecular N2 bubble formation in a (Ga,Fe)N magnetic semiconductor

DEFF Research Database (Denmark)

Kovács, András; Schaffer, B.; Moreno, M. S.

2011-01-01

Fe-doped GaN semiconductors are of interest for combining the properties of semiconductors and magnetic materials [1]. Depending on the growth temperature used, Fe can either be distributed homogenously in the GaN host lattice or it can accumulate in the form of Fe-N nanocrystals. As a result of ...

The Relationship between Parental Behaviors and Children's Sugary Drink Consumption Is Moderated by a Television in the Child's Bedroom.

Science.gov (United States)

Schwartz, Marlene B; Gilstad-Hayden, Kathryn; Henderson, Kathryn E; Luedicke, Joerg; Carroll-Scott, Amy; Peters, Susan M; McCaslin, Catherine; Ickovics, Jeannette R

2015-10-01

The aim of this longitudinal study was to examine the link between perceived authoritative parenting behaviors and sugary drink consumption among children from low-income families who do or do not have televisions (TVs) in their bedrooms. Middle school students (N = 480) completed a baseline survey in sixth grade and a follow-up survey in seventh grade. The students were recruited from 12 schools in a low-income, predominantly black (33%) and Latino (48%), urban school district. The survey assessed the children's perception of their parents' controlling and nurturing behaviors, the presence of a TV in their bedrooms, and their level of sugary drink consumption on the previous school day. Children's report of specific controlling and nurturing parental behaviors were used to create an "authoritative parenting" score. Regression analyses were used to test the main and interactive effects of authoritative parenting behaviors and having a TV in the bedroom with sugary drink consumption in seventh grade, controlling for age, race/ethnicity, gender, BMI, and sugary drink consumption in sixth grade. A significant interaction emerged: The authoritative parenting score predicted lower levels of sugary drink consumption in seventh grade, but this relationship was moderated by whether or not there was a TV in the child's bedroom. A TV in the child's bedroom may weaken the positive influence of authoritative parenting behaviors on limiting sugary drink consumption among middle school children from low-income families. Stronger initiatives are recommended to educate parents and help them refrain from placing TVs in their children's bedrooms.

Metal-organic framework derived Fe/Fe3C@N-doped-carbon porous hierarchical polyhedrons as bifunctional electrocatalysts for hydrogen evolution and oxygen-reduction reactions.

Science.gov (United States)

Song, Chunsen; Wu, Shikui; Shen, Xiaoping; Miao, Xuli; Ji, Zhenyuan; Yuan, Aihua; Xu, Keqiang; Liu, Miaomiao; Xie, Xulan; Kong, Lirong; Zhu, Guoxing; Ali Shah, Sayyar

2018-08-15

The development of simple and cost-effective synthesis methods for electrocatalysts of hydrogen evolution reaction (HER) and oxygen reduction reaction (ORR) is critical to renewable energy technologies. Herein, we report an interesting bifunctional HER and ORR electrocatalyst of Fe/Fe 3 C@N-doped-carbon porous hierarchical polyhedrons (Fe/Fe 3 C@N-C) by a simple metal-organic framework precursor route. The Fe/Fe 3 C@N-C polyhedrons consisting of Fe and Fe 3 C nanocrystals enveloped by N-doped carbon shells and accompanying with some carbon nanotubes on the surface were prepared by thermal annealing of Zn 3 [Fe(CN) 6 ] 2 ·xH 2 O polyhedral particles in nitrogen atmosphere. This material exhibits a large specific surface area of 182.5 m 2  g -1 and excellent ferromagnetic property. Electrochemical tests indicate that the Fe/Fe 3 C@N-C hybrid has apparent HER activity with a relatively low overpotential of 236 mV at the current density of 10 mA cm -2 and a small Tafel slope of 59.6 mV decade -1 . Meanwhile, this material exhibits excellent catalytic activity toward ORR with an onset potential (0.936 V vs. RHE) and half-wave potential (0.804 V vs. RHE) in 0.1 M KOH, which is comparable to commercial 20 wt% Pt/C (0.975 V and 0.820 V), and shows even better stability than the Pt/C. This work provides a new insight to developing multi-functional materials for renewable energy application. Copyright © 2018 Elsevier Inc. All rights reserved.

Community Involvement in School: Social Relationships in a Bedroom Community

Science.gov (United States)

Preston, Jane P.

2013-01-01

The purpose of this qualitative case study was to describe how community involvement in school is associated with the social relationships existing/lacking within a bedroom community. Thirty-five interviews with school council members, teachers, and community members highlighted that traditional forms of community involvement in school generate…

High-temperature oxidation of iron, Fe-0.5 wt. % Al and Fe-1 wt% Al alloys in CO2 at atmospheric pressure

International Nuclear Information System (INIS)

Hoogewys, Marcel; Paideassi, Jean.

1978-12-01

The oxidation of several grades of iron (on being a zone-melting grade) in the poly- and monocrystalline forms between 570 and 1150 0 C proceeds along a linear, then a transitory and a parabolic law in correspondence with the growth of wustite possibly covered with magnetite, whereas in the 400-570 0 C range where the parabolic law is rapidly establishing, the scale is entirely formed of magnetite. The oxidation of the two Fe-A1 alloys follows similarly a quasi linear law after a very short linear period. Their weight gains differ only at 10% at most while remaining close to that of iron (except above 570 0 C where they are much lower). The activation energies correspponding to the parabolic process -and in some cases to the linear one- have been determined for each material. They are in the range 11 to 43 Kcal.mole -1 , such values being rather low. The characteristics of the oxide layers: mode and facies of nucleation and crystal growth -particularly of the ridges at grain boundaries- the evolution of interfaces, precipitation of magnetite within wustite, etc... have been thoroughly investigated. Finally mechanisms concerning the linear, transitory and parabolic oxidation processes have been proposed after a careful discussion of the results [fr

Association between electronic equipment in the bedroom and sedentary lifestyle, physical activity, and body mass index of children.

Science.gov (United States)

Ferrari, Gerson Luis de Moraes; Araújo, Timóteo Leandro; Oliveira, Luis Carlos; Matsudo, Victor; Fisberg, Mauro

2015-01-01

To describe the association between electronic devices in the bedroom with sedentary time and physical activity, both assessed by accelerometry, in addition to body mass index in children from São Caetano do Sul. The sample consisted of 441 children. The presence of electronic equipment (television, personal computer, and videogames) in the bedroom was assessed by a questionnaire. For seven consecutive days, children used an accelerometer to objectively monitor the sedentary time and moderate-to-vigorous physical activity. Body mass index was categorized as suggested by the World Health Organization. Overall, 73.9%, 54.2% and 42.8% of children had TV, computer, and videogames in the bedroom, respectively, and spent an average of 500.7 and 59.1 min/day of sedentary time and moderate-to-vigorous physical activity. Of the children, 45.3% were overweight/obese. Girls with a computer in the bedroom (45 min/day) performed less moderate-to-vigorous physical activity than those without it (51.4 min/day). Similar results were observed for body mass index in boys. Moderate-to-vigorous physical activity was higher and body mass index was lower in children that had no electronic equipment in the bedroom. Presence of a computer (β=-4.798) and the combination TV+computer (β=-3.233) were negatively associated with moderate-to-vigorous physical activity. Videogames and the combinations with two or three electronic devices were positively associated with body mass index. Sedentary time was not associated with electronic equipment. Electronic equipment in the children's bedroom can negatively affect moderate-to-vigorous physical activity and body mass index regardless of gender, school, and annual family income, which can contribute to physical inactivity and childhood obesity. Copyright © 2015 Sociedade Brasileira de Pediatria. Published by Elsevier Editora Ltda. All rights reserved.

Polar and semipolar GaN/Al0.5Ga0.5N nanostructures for UV light emitters

Science.gov (United States)

Brault, J.; Rosales, D.; Damilano, B.; Leroux, M.; Courville, A.; Korytov, M.; Chenot, S.; Vennéguès, P.; Vinter, B.; De Mierry, P.; Kahouli, A.; Massies, J.; Bretagnon, T.; Gil, B.

2014-06-01

AlxGa1-xN-based ultra-violet (UV) light emitting diodes (LEDs) are seen as the best solution for the replacement of traditional mercury lamp technology. By adjusting the Al concentration, a large emission spectrum range from 360 nm (GaN) down to 200 nm (AlN) can be covered. Owing to the large density of defects typically present in AlxGa1-xN materials usually grown on sapphire substrates, LED efficiencies still need to be improved. Taking advantage of the 3D carrier confinement, quantum dots (QDs) are among the solutions currently under investigation to improve the performances of UV LEDs. The objectives of this work are to present and discuss the morphological and optical properties of GaN nanostructures grown by molecular beam epitaxy on the (0 0 0 1) and the (11-22) orientations of Al0.5Ga0.5N. In particular, the dependence of the morphological properties of the nanostructures on the growth conditions and the surface orientation will be presented. The optical characteristics as a function of the nanostructure design (size, shape and dimensionality) will also be shown and discussed. The electroluminescence characteristics of a first series of QD-based GaN/Al0.5Ga0.5N LEDs grown on the polar (0 0 0 1) plane will be investigated.

Effect of zinc substitution on the structural, electrical and magnetic properties of nano-structured Ni0.5Co0.5Fe2O4 ferrites

Science.gov (United States)

Babu, K. Vijaya; Sailaja, B.; Jalaiah, K.; Shibeshi, Paulos Taddesse; Ravi, M.

2018-04-01

A series of Ni0.5Co0.5-xZnxFe2O4 (x = 0, 0.02, 0.04 and 0.06) nanoferrites were synthesized by sol-gel method using citric acid as chelating reagent. The synthesized ferrite systems are characterized by XRD, SEM, FTIR, ESR and dielectric techniques. The formation of cubic spinel phase belonging to space group Fd3m is identified from the X-ray diffraction patterns. SEM showed the particles are in spherical shape with an average grain size 5-10 nm. FTIR spectra portrait the fundamental absorption bands in the range 400-600 cm-1 relating to octahedral and tetrahedral sites. Dielectric properties are investigated over the frequency range of 20 Hz to 1 MHz at room temperature. A difference in dielectric constant (εr) and dissipation factor (tanδ) of the ferrites has been observed. The dielectric constant and dielectric loss tangent decreases exponentially with increase in frequency. The obtained results are good agreeing with the reported values.

Room temperature multiferroic properties of Pb(Fe{sub 0.5}Nb{sub 0.5})O{sub 3}–Co{sub 0.65}Zn{sub 0.35}Fe{sub 2}O{sub 4} composites

Energy Technology Data Exchange (ETDEWEB)

Pradhan, Dhiren K., E-mail: dhirenkumarp@gmail.com, E-mail: rkatiyar@hpcf.upr.edu; Katiyar, Ram S., E-mail: dhirenkumarp@gmail.com, E-mail: rkatiyar@hpcf.upr.edu [Department of Physics and Institute of Functional Nanomaterials, University of Puerto Rico, San Juan, Puerto Rico 00936 (United States); Puli, Venkata S. [Department of Physics and Engineering Physics, Tulane University, New Orleans, Louisiana 70118 (United States); Narayan Tripathy, Satya; Pradhan, Dillip K. [Department of Physics, National Institute of Technology, Rourkela 769008 (India); Scott, J. F. [Department of Physics and Institute of Functional Nanomaterials, University of Puerto Rico, San Juan, Puerto Rico 00936 (United States); Department of Physics, Cavendish Laboratory, University of Cambridge, Cambridge (United Kingdom)

2013-12-21

We report the crystal structure, magnetic, ferroelectric, dielectric, and magneto-dielectric properties of [Pb(Fe{sub 0.5}Nb{sub 0.5})O{sub 3}]{sub (1−x)}[Co{sub 0.65}Zn{sub 0.35}Fe{sub 2}O{sub 4}]{sub x}: (x = 0.1, 0.2, 0.3, and 0.4) composites. Rietveld refinement results of X-ray diffraction patterns confirm the formation of these composites for all x values. All the composites show well-saturated ferroelectric and ferromagnetic hysteresis (multiferroic-composite behavior) at room temperature. With increase in Co{sub 0.65}Zn{sub 0.35}Fe{sub 2}O{sub 4} (CZFO) content an increase in saturation magnetization, and decrease in saturation polarization, remanent polarization, and dielectric constant are observed. The ferroelectric phase transition temperature increases with increase in CZFO content. All of the compositions undergo second-order ferroelectric phase transitions, which can be explained by Landau-Devonshire theory. The recoverable energy density (∼0.20 to 0.04 J/cm{sup 3}) and charge-curve energy density (∼0.84 to 0.11 J/cm{sup 3}) decrease with increase in the CZFO content. The room-temperature magneto-dielectric measurements provide direct evidence of magneto-electric coupling via strain at room temperature.

Pressure induced magnetic phase transition in RhFe{sub 3}N and IrFe{sub 3}N: An ab-initio study

Energy Technology Data Exchange (ETDEWEB)

Puvaneswari, S. [Department of physics, E.M.G.Yadava women’s college, Madurai, Tamilnadu-625014 (India); Manikandan, M. [Department of physics, N.M.S.S.V.N college, Madurai, Tamilnadu-625019 (India); Rajeswarapalanichamy, R., E-mail: rrpalanichamy@gmail.com

2016-05-06

The structural, electronic, elastic and magnetic properties of RhFe{sub 3}N and IrFe{sub 3}N are investigated using ab-initio calculations based on density functional theory as implemented in VASP code within the gradient generalized approximation. The non-spin polarized and spin polarized calculations are performed for these nitrides at normal and high pressures. It is found that these ternary nitrides are stable in ferromagnetic state at normal pressure. The lattice constant and bulk modulus values are calculated. The electronic structure reveals that these nitrides are metallic at normal pressure. The calculated elastic constants indicate that they are mechanically stable at ambient pressure. Ferromagnetic to nonmagnetic phase transition is observed in RhFe{sub 3}N and IrFe{sub 3}N at high pressure. Ferromagnetism is quenched in these nitrides at high pressure.

(SiC/AlN)2 multilayer film as an effective protective coating for sintered NdFeB by magnetron sputtering

Science.gov (United States)

You, Yu; Li, Heqin; Huang, Yiqin; Tang, Qiong; Zhang, Jing; Xu, Jun

2017-08-01

SiC/AlN and (SiC/AlN)2 multilayer films with a well-arranged bilayer structure and a four-layer structure are prepared respectively on NdFeB substrates by a magnetron sputtering method. Crystal phase and microstructures of the SiC/AlN and (SiC/AlN)2 films are investigated using x-ray diffraction (XRD), field-emission scanning electron microscope (FESEM) and atomic force microscope (AFM). It is observed that the surface of the (SiC/AlN)2 four-layer film is much denser and smoother than that of the SiC/AlN bilayer film. Corrosion behaviors of the NdFeB substrates coated with SiC/AlN and (SiC/AlN)2 films as well as the bare NdFeB substrate are evaluated by potentiodynamic polarization curve tests. It is revealed that the lateral growth structures developed in interfaces are favorable for an enhanced corrosion resistance. Corrosion current densities of the (SiC/AlN)2 coated NdFeB measured in acid, alkali and salt solutions are 2.796  ×  10-9, 3.65  ×  10-6, and 2.912  ×  10-6 A cm-2, respectively, which are much lower than those of the bare NdFeB and the SiC/AlN coated NdFeB.

Inversion of exchange bias and complex magnetization reversal in full-nitride epitaxial γ′-Fe{sub 4}N/CoN bilayers

Energy Technology Data Exchange (ETDEWEB)

Li, Z.R. [Tianjin Key Laboratory of Low Dimensional Materials Physics and Preparation Technology, Institute of Advanced Materials Physics, Faculty of Science, Tianjin University, Tianjin 300072 (China); Mi, W.B., E-mail: miwenbo@tju.edu.cn [Tianjin Key Laboratory of Low Dimensional Materials Physics and Preparation Technology, Institute of Advanced Materials Physics, Faculty of Science, Tianjin University, Tianjin 300072 (China); Wang, X.C. [Tianjin Key Laboratory of Film Electronic & Communicate Devices, School of Electronics Information Engineering, Tianjin University of Technology, Tianjin 300384, China (China); Bai, H.L. [Tianjin Key Laboratory of Low Dimensional Materials Physics and Preparation Technology, Institute of Advanced Materials Physics, Faculty of Science, Tianjin University, Tianjin 300072 (China)

2015-04-01

Exchange bias has been observed in the full-nitride epitaxial γ′-Fe{sub 4}N/CoN bilayers. With the increase of temperature, the sign of exchange bias (EB) is inverse, which is independent on the cooling field and training effect. This novel behavior appears in the bilayers with different CoN and γ′-Fe{sub 4}N thicknesses. The inversion of EB sign not only occurs at low temperatures, but also takes place even at 200 K for the 10 and 12 nm thick CoN layer. With the decreased γ′-Fe{sub 4}N layer thickness, the inversion temperature of EB sign shows a roughly increased tendency. For the bilayer with a 4 nm-thick γ′-Fe{sub 4}N, the interfacial magnetization reversal presents a complex trend, which is considered as the combined actions of the disordered ferromagnetic spins and various competed magnetic structures. This new manifestation of EB has been discussed in terms of the complicated interfacial spin structures and frustration effects due to the competition between the ferromagnetic and antiferromagnetic exchange interactions at the interface. - Highlights: • Exchange bias (EB) sign reverses from negative to positive with increasing temperature in epitaxial γ′-Fe{sub 4}N/CoN bilayers. • The positive EB can be attributed to the antiferromagnetic interfacial coupling and frustrated interfacial spin structures. • The EB transition temperature is not monotonically dependent on CoN thickness t{sub CoN}. • For a 4-nm γ′-Fe{sub 4}N, the unusual hysteresis loops are observed.

Complex impedance techniques and some properties of Mn sub 0.5 Zn sub 0.5 Fe sub 2 O sub 4 ferrite

International Nuclear Information System (INIS)

Ahmad Nazlim Yusoff; Mustaffa Abdullah

1995-01-01

Complex impedances (Z-axes = Z' - jZ ) of a standard parallel R-C circuit and a Mn sub 0.5 Zn sub 0.5 Fe sub 2 O sub 4 ferrite sample at 300 K have been measured in the frequency range 1 Hz to 10 MHz by a technique of phase shift. For comparison, the impedances of both systems were also measured using Schlumberger HF 1255 frequency response analyzer. The complex impedance spectrum (Z' vs Z') from the R-C circuit is a perfect semicircle, whereas the spectrum for the ferrite sample is a semicircular curve with its centre being depressed to below the real impedance axis. The depression of the semicircle for the ferrite is discussed as due to a deviation from the ideal Debye relaxation process. An equivalent circuit model that comprises of a capacitor and a resistor in parallel is suggested for the ferrite, but the result for the impedance is modified by including a factor that accounts for the distribution of the relaxation time. The simulated data from the circuit are in agreement with those from the experiment. The dispersion of the impedance is attributed to the conduction and polarization processes in the material

Magnetoresistance and magnetostriction of Ni81Fe19 and Co90Fe10 mono- and bilayer films

International Nuclear Information System (INIS)

Sahingoz, R.; Hollingworth, M.P.; Gibbs, M.R.J.; Murdoch, S.J.

2005-01-01

Monolayer and bilayer films of Ni 81 Fe 19 , Co 90 Fe 10 , Co 90 Fe 10 /Ni 81 Fe 19 , and Ni 81 Fe 19 /Co 90 Fe 10 have been grown on thermally oxidized Si. The magnetoresistance (MR) of the samples was measured as a function of applied DC magnetic field, using a four-point probe method. The magnetostriction constant, λ s , was derived from the change of anisotropy field as a function of strain. The dependence of the MR on different combinations of film layers was investigated. The magnetoresistance of the bilayers changed dramatically upon reversal of the layer order. The mono- and bilayer samples with the same material on top of the substrate showed similar MR loop shapes. However, the saturation fields of the bilayers were larger than those for the monolayers. The magnetostriction of all samples was negative. We discuss the consequences for the study and optimization of spin-valve devices

Structural, Dielectric, and Electrical Properties of Bi1- x Pb x Fe1- x (Zr0.5Ti0.5) x O3

Science.gov (United States)

Panda, Niranjan; Pattanayak, Samita; Choudhary, R. N. P.

2015-12-01

Polycrystalline samples of Bi1- x Pb x Fe1- x (Zr0.5Ti0.5) x O3 (BPFZTO) with x = 0.0, 0.2, 0.3, and 0.4 were prepared by high-temperature solid-state reaction. Preliminary structural analysis of calcined powders of the materials by use of x-ray powder diffraction confirmed formation of single-phase systems with the tetragonal structure. Room-temperature scanning electron micrographs of the samples revealed uniform distribution of grains of low porosity and different dimensions on the surface of the samples. The frequency-temperature dependence of dielectric and electric properties was studied by use of dielectric and complex impedance spectroscopy over a wide range of frequency (1 kHz to 1 MHz) at different temperatures (25-500°C). The dielectric constant of BiFeO3 (BFO) was enhanced by substitution with Pb(Zr0.5Ti0.5)O3 (PZT) whereas the dielectric loss of the BPFZTO compounds decreased with increasing PZT content. A significant contribution of both grains and grain boundaries to the electrical response of the materials was observed. The frequency-dependence of the ac conductivity of BPFZTO followed Jonscher's power law. Negative temperature coefficient of resistance behavior was observed for all the BPFZTO samples. Conductivity by thermally excited charge carriers and oxygen vacancies in the materials was believed to be of the Arrhenius-type.

Fe2Ni2N nanosheet array: an efficient non-noble-metal electrocatalyst for non-enzymatic glucose sensing

Science.gov (United States)

You, Chao; Dai, Rui; Cao, Xiaoqin; Ji, Yuyao; Qu, Fengli; Liu, Zhiang; Du, Gu; Asiri, Abdullah M.; Xiong, Xiaoli; Sun, Xuping; Huang, Ke

2017-09-01

It is very important to develop enhanced electrochemical sensing platforms for molecular detection and non-noble-metal nanoarray architecture, as electrochemical catalyst electrodes have attracted great attention due to their large specific surface area and easy accessibility to target molecules. In this paper, we demonstrate that an Fe2Ni2N nanosheet array grown on Ti mesh (Fe2Ni2N NS/TM) shows high electrocatalytic activity toward glucose electrooxidation in alkaline medium. As an electrochemical glucose sensor, such an Fe2Ni2N NS/TM catalyst electrode demonstrates superior sensing performance with a short response time of less than 5 s, a wide linear range of 0.05 μM-1.5 mM, a low detection limit of 0.038 μM (S/N = 3), a high sensitivity of 6250 μA mM-1 cm-2, as well as high selectivity and long-term stability.

Exchange bias induced at a Co2FeAl0.5Si0.5/Cr interface

International Nuclear Information System (INIS)

Yu, C N T; Vick, A J; Inami, N; Ono, K; Frost, W; Hirohata, A

2017-01-01

In order to engineer the strength of an exchange bias in a cubic Heusler alloy layer, crystalline strain has been induced at a ferromagnet/antiferromagnet interface by their lattice mismatch in addition to the conventional interfacial exchange coupling between them. Such interfaces have been formed in (Co 2 FeAl 0.5 Si 0.5 (CFAS)/Cr) 3 structures grown by ultrahigh vacuum molecular beam epitaxy. The magnetic and structural properties have been characterised to investigate the exchange interactions at the CFAS/Cr interfaces. Due to the interfacial lattice mismatch of 1.4%, the maximum offset of 18 Oe in a magnetisation curve has been measured for the case of a CFAS (2 nm)/Cr (0.9 nm) interface at 193 K. The half-metallic property of CFAS has been observed to remain unchanged, which agrees with the theoretical prediction by Culbert et al (2008 J. Appl. Phys . 103 07D707). Such a strain-induced exchange bias may provide insight of the interfacial interactions and may offer a wide flexibility in spintronic device design. (paper)

Polar and semipolar GaN/Al0.5Ga0.5N nanostructures for UV light emitters

International Nuclear Information System (INIS)

Brault, J; Damilano, B; Leroux, M; Courville, A; Korytov, M; Chenot, S; Vennéguès, P; Vinter, B; De Mierry, P; Kahouli, A; Massies, J; Rosales, D; Bretagnon, T; Gil, B

2014-01-01

Al x Ga 1−x N-based ultra-violet (UV) light emitting diodes (LEDs) are seen as the best solution for the replacement of traditional mercury lamp technology. By adjusting the Al concentration, a large emission spectrum range from 360 nm (GaN) down to 200 nm (AlN) can be covered. Owing to the large density of defects typically present in Al x Ga 1−x N materials usually grown on sapphire substrates, LED efficiencies still need to be improved. Taking advantage of the 3D carrier confinement, quantum dots (QDs) are among the solutions currently under investigation to improve the performances of UV LEDs. The objectives of this work are to present and discuss the morphological and optical properties of GaN nanostructures grown by molecular beam epitaxy on the (0 0 0 1) and the (11–22) orientations of Al 0.5 Ga 0.5 N. In particular, the dependence of the morphological properties of the nanostructures on the growth conditions and the surface orientation will be presented. The optical characteristics as a function of the nanostructure design (size, shape and dimensionality) will also be shown and discussed. The electroluminescence characteristics of a first series of QD-based GaN/Al 0.5 Ga 0.5 N LEDs grown on the polar (0 0 0 1) plane will be investigated. (invited article)

(CaFeAs)10PtzAs8 superconductors and related compounds

International Nuclear Information System (INIS)

Stuerzer, Tobias

2015-01-01

The main topic of this dissertation is the identification of new compounds, structure determination, and substitution dependent investigation of properties in this new branch of the family of iron arsenide superconductors (Chapter 2). Chapter 2.1 presents the identification of the superconducting compounds and the corresponding structure elucidation identifying two dif-ferent species (CaFeAs) 10 Pt 3 As 8 and (CaFeAs) 10 Pt 4 As 8 in this family (abbreviated as 1038 and 1048 according to their stoichiometry). However, a closer look revealed a more challenging structure chemistry which is covered in Chapter 2.2. The following two Chapters 2.3 and 2.4 are devoted to (CaFeAs) 10 Pt 3 As 8 and more detailed investigations on this parent compound of the new superconductor family. Furthermore, transition metal substitution series (CaFe 1-x M x As) 10 Pt 3 As 8 were synthesized to investigate the resemblance to model systems Ba(Fe 1-x M x ) 2 As x and LaO(Fe 1-x M x )As in the scope of structural changes and superconductivity as described in Chapter 2.5. Initially amazing differences in superconducting properties com-paring 1038 and 1048 compounds are analyzed in Chapter 2.6 establishing an universal dop-ing model in the (CaFe 1-x M x As) 10 Pt z As 8 family. Additionally substituent dependent properties upon rare earth substitution in electron doped (Ca 1-y RE y FeAs) 10 Pt 3 As 8 are investigated in Chapter 2.7, while a detailed study of superconducting properties and magnetism in (Ca 1-y La y FeAs) 10 Pt 3 As 8 by the local μSR technique is presented in Chapter 2.8. In Chapter 2.9 a comparison of direct and electron doping is discussed based on codoping experiments in (Ca 1-y La y Fe 1-x Pt x As) 10 Pt 3 As 8 and (CaFe 1-x Pt x As) 10 Pt 4 As 8 . Finally, in Chapter 2.10 electron doping in stoichiometric 1048 is studied by charge compensation experiments in (Ca 1-y Na y FeAs) 10 Pt 4 As 8 . Chapter 3 is dedicated to a new family of calcium iron arsenides featuring

Bedroom air quality and vacuuming frequency are associated with repeat child asthma hospital admissions.

Science.gov (United States)

Vicendese, Don; Dharmage, Shyamali C; Tang, Mimi L K; Olenko, Andriy; Allen, Katrina J; Abramson, Michael J; Erbas, Bircan

2015-09-01

Indoor environment factors have been associated with risk of asthma exacerbations in children but little is known about their role on asthma hospital readmissions. As children in Western societies continually spend more time indoors, understanding the influence of these factors on asthma exacerbation is important. We examined the role of indoor environmental and lifestyle characteristics on child asthma readmissions. A hospital-based case-control study recruited 22 children readmitted for asthma and 22 controls not readmitted for asthma. Logistic regression models were used to examine the association between aeroallergens and fungi in the bedroom and indoor lifestyle characteristics factors for asthma readmissions. To determine the best possible set of predictors among a large set of risk factors, we used random forests (RF) techniques. Higher levels of airborne Cladosporium and yeast in the child's bedroom increased risk of readmission (OR = 1.68, 95% CI 1.04-2.72 and OR = 1.52, 95% CI 0.99-2.34, respectively). Carpeted floors in the bedroom and synthetic doonas were also associated with increase in asthma readmissions (OR = 4.07, 95% CI 1.03-16.06 and OR = 14.6, 95% CI 1.26-169.4, respectively). In the home, frequent vacuuming using bagged cleaners increased risk of asthma readmission OR = 15.7 (95% CI 2.82-87.2). Factors in the child's bedroom play an important role in increasing the risk of asthma hospital readmissions. These findings have major clinical implications as the identified potential risk factors may be modifiable. Further epidemiological studies with larger samples are necessary to evaluate these associations further.

Diffusion of N adatoms on the Fe(100) surface

DEFF Research Database (Denmark)

Pedersen, M. Ø.; Österlund, L.; Mortensen, Jens Jørgen

2000-01-01

The diffusion of individual N adatoms on Fe(100) has been studied using scanning tunneling microscopy and ab initio density functional theory (DFT) calculations. The measured diffusion barrier for isolated N adatoms is E-d = (0.92 +/- 0.04) eV, with a prefactor of nu(0) = 4.3 x 10(12) s(-1), which...... is in quantitative agreement with the DFT calculations. Thr; diffusion is strongly coupled to lattice distortions. and. as a consequence, the presence of other N adatoms introduces an anisotropy in the diffusion. Based on experimentally determined values of the diffusion barriers and adsorbate......-adsorbate: interactions, the potential energy surface experienced by a N adatom is determined....

78 FR 69703 - 10-Day Notice of Proposed Information Collection: Generic Customer Satisfaction Surveys; Physical...

Science.gov (United States)

2013-11-20

... DEPARTMENT OF HOUSING AND URBAN DEVELOPMENT [Docket No. FR-5683-N-102] 10-Day Notice of Proposed Information Collection: Generic Customer Satisfaction Surveys; Physical Inspection Pilot Program...

Evaluation of the 46Ti(n,2n)45Ti and 54Fe(n,2n)53m+gFe reaction cross sections for neutron dosimetry in fusion facilities

International Nuclear Information System (INIS)

Badikov, S.A.; Ignatyuk, A.V.; Zolotarev, K.I.; Pashchenko, A.B.

1993-11-01

The reaction cross-sections of 46 Ti(n,2n) 45 Ti and 54 Fe(n,2n) 53m+g Fe, which are important for fusion reactor neutron dosimetry, were evaluated using a generalized least squares method. The experimental cross-section data of all measurements performed up to January 1993, were critically reviewed. The evaluated cross-section data are presented in analytical form and in ENDF-6 format, including covariance data. (author)

High-frequency permeability of electroplated CoNiFe and CoNiFe-C alloys

International Nuclear Information System (INIS)

Rhen, Fernando M.F.; McCloskey, Paul; O'Donnell, Terence; Roy, Saibal

2008-01-01

We have investigated CoNiFe and CoNiFe-C electrodeposited by pulse reverse plating (PRP) and direct current (DC) techniques. CoNiFe(PRP) films with composition Co 59.4 Fe 27.7 Ni 12.8 show coercivity of 95 A m -1 (1.2 Oe) and magnetization saturation flux (μ 0 M s ) of 1.8 T. Resistivity of CoNiFe (PRP) is about 24 μΩ cm and permeability remains almost constant μ r ' ∼475 up to 30 MHz with a quality factor (Q) larger than 10. Additionally, the permeability spectra analysis shows that CoNiFe exhibits a classical eddy current loss at zero bias field and ferromagnetic resonance (FMR) when biased with 0.05 T. Furthermore, a crossover between eddy current and FMR loss is observed for CoNiFe-PRP when baised with 0.05 T. DC and PRP plated CoNiFe-C, which have resistivity and permeability of 85, 38 μΩ cm, μ r '=165 and 35 with Q>10 up to 320 MHz, respectively, showed only ferromagnetic resonance losses. The ferromagnetic resonance peaks in CoNiFe and CoNiFe-C are broad and resembles a Gaussian distribution of FMR frequencies. The incorporation of C to CoNiFe reduces eddy current loss, but also reduces the FMR frequency

Creep behavior of perovskite-type oxides Ba0.5Sr0.5(Co0.8Fe0.2)1−xZrxO3−δ

NARCIS (Netherlands)

Stournari, V.; ten Donkelaar, S.F.P.; Malzbender, J.; Beck, T.; Singheiser, L.; Bouwmeester, Henricus J.M.

2015-01-01

Compressive creep tests have been performed on perovskite-type oxides Ba0.5Sr0.5(Co0.8Fe0.2)1–xZrxO3−δ (BSCF-Z100·x), where x = 0.01, 0.03, 0.05 and 0.1, for the use as oxygen transport membrane, in air at 800–950 °C and at nominal stresses of 30 MPa and 63 MPa. X-ray diffraction and microstructural

Microstructural analysis nanoferritas Mn{sub 0,5}Zn{sub 0,5}Fe{sub 2}O{sub 4} e Mn{sub 0,65}Zn{sub 0,35}Fe{sub 2}O{sub 4} synthesized by combustion reaction; Analise microestrutural de nanoferritas Mn{sub 0,5}Zn{sub 0,5}Fe{sub 2}O{sub 4} e Mn{sub 0,65}Zn{sub 0,35}Fe{sub 2}O{sub 4} sintetizadas por reacao de combustao

Energy Technology Data Exchange (ETDEWEB)

Diniz, V.C.S.; Figueiredo, A.R.; Costa Junior, A.D.S.; Diniz, H.M.; Vieira, D.A.; Costa, A.C.F.M., E-mail: veronicacristhina@hotmail.com [Universidade Federal de Campina Grande (UFCG), PB (Brazil). Departamento de Engenharia de Materiais

2014-07-01

The MnZn ferrites are ferrimagnetic materials that have been studied and used in various technological fields. In this work investigated the microstructural characteristics of ferrites and Mn{sub 0,5}Zn{sub 0,5}Fe{sub 2}O{sub 4} Mn{sub 0,65}Zn{sub 0,35}Fe{sub 2}O{sub 4} synthesized by combustion reaction in 200g scale production. The samples were characterized by XRD, crystallinity, crystallite size, X-ray fluorescence and scanning electron microscopy. Given the results it was observed that for both samples the synthesis combustion reaction was efficient for the production of single-phase ferrites with high crystallinity. With respect to the analysis of X-ray fluorescence was noted that the experimental values composition were consistent with the theoretical values calculated for both samples. Regarding morphology for both samples, the formation of the porous powders with feature consisting of dense clumps in the form of irregular foam was observed. (author)

Effect of Fe substitution on magnetocaloric effect in La0.7Sr0.3Mn1-xFexO3 (0.05≤x≤0.20)

International Nuclear Information System (INIS)

Barik, S.K.; Krishnamoorthi, C.; Mahendiran, R.

2011-01-01

We have studied the effect of Fe substitution on magnetic and magnetocaloric properties in La 0.7 Sr 0.3 Mn 1-x Fe x O 3 (x=0.05, 0.07, 0.10, 0.15, and 0.20) over a wide temperature range (T=10-400 K). It is shown that substitution by Fe gradually decreases the ferromagnetic Curie temperature (T C ) and saturation magnetization up to x=0.15 but a dramatic change occurs for x=0.2. The x=0.2 sample can be considered as a phase separated compound in which both short-range ordered ferromagnetic and antiferromagnetic phases coexist. The magnetic entropy change (-ΔS m ) was estimated from isothermal magnetization curves and it decreases with increase of Fe content from 4.4 J kg -1 K -1 at 343 K (x=0.05) to 1.3 J kg -1 K -1 at 105 K (x=0.2), under ΔH=5 T. The La 0.7 Sr 0.3 Mn 0.93 Fe 0.07 O 3 sample shows negligible hysteresis loss, operating temperature range over 60 K around room temperature with refrigerant capacity of 225 J kg -1 , and magnetic entropy of 4 J kg -1 K -1 which will be an interesting compound for application in room temperature refrigeration. - Research highlights: → We report magnetocaloric effect in La 0.7 Sr 0.3 Mn 1-x Fe x O 3 (x=0-0.2). → Magnetic entropy change (ΔS m ) decreases with increasing x. → A large ΔS m and refrigeration capacity are found around 300 K in x=0.07.

Study of U - Pu - Fe alloys (Masurca critical experiment)

International Nuclear Information System (INIS)

Barthelemy, P.; Boucher, R.

1965-01-01

Three compositions have been studied: 73.5 U - 25 Pu - 1.5 Fe (weight %) 74 U - 25 Pu - 1 Fe 74.5 U - 25 Pu - 0.5 Fe Elaboration and Casting are easy. After two weeks in air 74.5 U - 25 Pu - 0.5 Fe alloys are reduced in powder. As-cast alloys containing 1 and 1,5% Fe are kept undamaged during several months. A rapid oxidisation of the alloys is however observed when the samples undergo the phase transformation (at 595 deg. C and 590 deg. C respectively). Ignition tests in the presence of air show that the oxidisation starts at about 250 deg. C and that the reaction does not spread. Ignition is not observed during heating from 20 to 660 deg. C. The transformation temperature, the melting temperature and the thermal expansion coefficients have been determined by dilatometry. Below the transformation temperature, the principal phases are U-Pu zeta and (U, Pu) 6 Fe. Thermal conductibility, Young modulus, density and heat of fusion have been measured. Compatibility tests show that between U-Pu-Fe and stainless steel a phase of (U, Pu) 6 Fe type is formed. The 74 U - 25 Pu - 1% Fe alloy seems to behave better than 73.5 U - 25 Pu - 1.5% Fe alloy because the (U, Pu) 6 Fe layer is two or three times smaller. Finally, the thermal stability has been studied with the 74 U - 25 Pu - 1% Fe alloy. A dilatometric anomaly (very weak expansion) occurs when the sample is heated above transformation temperature and cooled. But there is no anomaly by thermal cycling from 50 deg. C to 400 deg. C and there is no deterioration of alloys by heat treatments at 100 deg. C, 200 deg. C, 300 deg. C during 5 months under vacuum. (authors) [fr

Wooden floors: part of historical antiseismic building systems

Directory of Open Access Journals (Sweden)

F. Laner

1995-06-01

Full Text Available The article describes how wooden floors have been used over the centuries as a means of ensuring greater building solidity to ensure against earthquakes or other events that threaten wall stability.

Strain mediated magnetoelectric coupling induced in (x) Bi{sub 0.5}Na{sub 0.5}TiO{sub 3}-(1−x) MgFe{sub 2}O{sub 4} composites

Energy Technology Data Exchange (ETDEWEB)

Manjusha [Smart Materials Research Laboratory, Department of Physics, Indian Institute of Technology Roorkee, Roorkee 247667 (India); Yadav, K.L., E-mail: klyadav35@yahoo.com [Smart Materials Research Laboratory, Department of Physics, Indian Institute of Technology Roorkee, Roorkee 247667 (India); Adhlakha, Nidhi [Elettra-Sincrotrone Trieste S.C.p.A, Area Science Park, I-34012 Trieste (Italy); Shah, Jyoti; Kotnala, R.K. [CSIR-National Physical Laboratory, New Delhi 110012 (India)

2017-06-01

Particulate composites of ferroelectric and ferrite phases having general formula (x)Bi{sub 0.5}Na{sub 0.5}TiO{sub 3}-(1−x)MgFe{sub 2}O{sub 4} (x=0, 0.5, 0.6, 0.7, 0.8 and 1.0), equivalently denoted as (x)BNT-(1−x)MgFO were synthesized by solid state reaction method. From X-ray diffraction analysis, the structural transformation from tetragonal to rhombohedral corresponding to BNT phase was observed in composites with x=0.5 to x=0.8. Shifting of (012) BNT peak towards left (x=0.5, 0.8) and right side (x=0.6, 0.7) observed due to occupation of Bi{sup 3+} ions at interstitial and substitutional sites into host MgFO lattice respectively. BNT produced strain in MgFO lattice. Scanning electron micrographs show closely packed microstructure with grain size variations from 0.62 to 2.90 µm. The value of magnetoelectric (ME) coupling coefficient increases from 2.42 (x=0.5) to 4.79 (x=0.8) mV/cm. Oe due to strain produced in MgFO and BNT lattices.

Design and Micromagnetic Simulation of Fe/L10-FePt/Fe Trilayer for Exchange Coupled Composite Bit Patterned Media at Ultrahigh Areal Density

Directory of Open Access Journals (Sweden)

Warunee Tipcharoen

2015-01-01

Full Text Available Exchange coupled composite bit patterned media (ECC-BPM are one candidate to solve the trilemma issues, overcome superparamagnetic limitations, and obtain ultrahigh areal density. In this work, the ECC continuous media and ECC-BPM of Fe/L10-FePt/Fe trilayer schemes are proposed and investigated based on the Landau-Lifshitz-Gilbert equation. The switching field, Hsw, of the hard phase in the proposed continuous ECC trilayer media structure is reduced below the maximum write head field at interlayer exchange coupling between hard and soft phases, Aex, higher than 20 pJ/m and its value is lower than that for continuous L10-FePt single layer media and L10-FePt/Fe bilayer. Furthermore, the Hsw of the proposed ECC-BPM is lower than the maximum write head field with exchange coupling coefficient between neighboring dots of 5 pJ/m and Aex over 10 pJ/m. Therefore, the proposed ECC-BPM trilayer has the highest potential and is suitable for ultrahigh areal density magnetic recording technology at ultrahigh areal density. The results of this work may be gainful idea for nanopatterning in magnetic media nanotechnology.

The Effects of a High Magnetic Field on the Annealing of [(Fe0.5Co0.50.75B0.2Si0.05]96Nb4 Bulk Metallic Glass

Directory of Open Access Journals (Sweden)

Peng Jia

2016-11-01

Full Text Available In contrast with amorphous alloys, nanocrystalline soft magnetic materials show improved thermal stability and higher soft magnetic properties. The nanocrystalline soft magnetic composites are usually fabricated by partially crystallizing from parent amorphous alloys. This paper reports our experimental observation on the sequence of crystallization in metallic glass under a high magnetic field (HMF. An application of a HMF to bulk metallic glass (BMG of [(Fe0.5Co0.50.75B0.2Si0.05]96Nb4 prioritizes the precipitation of α-(Fe,Co phase separated from the subsequent precipitation of borides, (Fe,Co23B6, upon isothermal annealing at a glass transition temperature. Furthermore, it was observed that, through the annealing treatment under a HMF, a soft magnetic nanocomposite, in which only α-(Fe,Co phase uniformly distributes in amorphous matrix, was achieved for boron-bearing BMG. The promotion of the α-Fe or (Fe,Co phase and the prevention of the boride phases during the isothermal annealing process help to produce high-quality soft magnetic nanocomposite materials. The mechanism by which a HMF influences the crystallization sequence was interpreted via certain changes in Gibbs free energies for two ferromagnetic phases. This finding evidences that the annealing treatment under a HMF is suitable for enhancing the soft magnetic properties of high B content (Fe,Co-based bulk amorphous and nanocrystalline materials.

Wooden's pyramid: building a hierarchy of skills for successful communication.

Science.gov (United States)

Epner, Daniel E; Baile, Walter F

2011-01-01

John Wooden, the legendary college basketball coach, created the "Pyramid of Success", which he constructed from 14 timeless character traits and interpersonal skills that are critical to competitive greatness. Wooden's pyramid is a powerful symbol that he and others have used for several decades as an educational tool to promote leadership and teamwork. This article proposes the "Pyramid of Relational Excellence (PRE)", patterned after Wooden's pyramid, as a mnemonic-based educational symbol for communication skills training. Literature review, personal reflection. The PRE is constructed of four tiers with a total of 12 building blocks, with each successive tier built upon the one beneath it. The building blocks represent fundamental elements that are known to be critical to successful communication. The PRE is process oriented rather than task oriented and focuses exclusively on the face-to-face encounter. It therefore complements established communications curricula, such as the UK communication wheel and others, which are more comprehensive and task oriented. The PRE is constructed of timeless, fundamental principles. It is therefore particularly well suited for training medical students and residents.

Residential characteristics and radiofrequency electromagnetic field exposures from bedroom measurements in Germany

DEFF Research Database (Denmark)

Breckenkamp, J; Blettner, M; Schüz, J

2012-01-01

The objectives of this study were to assess total exposure to radiofrequency electromagnetic fields (RF-EMF) in bedrooms and the contribution of different radioservices (FM radio, analogue TV and DVB-T, TETRA, GSM900 downlink, GSM1800 downlink, UMTS downlink, DECT, and wireless LAN and blue tooth......) to the total exposure. Additional aims were to describe the proportion of measuring values above the detection limit of the dosimeters and to characterize the differences in exposure patterns associated with self-reported residential characteristics. Exposure to RF sources in bedrooms was measured using...... Antennessa(®) EME Spy 120 dosimeters in 1,348 households in Germany; 280 measures were available for each frequency band per household. Mean electrical field strengths and power flux densities were calculated. Power flux densities allow the calculation of proportions of different radioservices on total...

Study of microstructure and magnetic properties of L10 FePt/SiO2 thin films

Directory of Open Access Journals (Sweden)

Giannopoulos G.

2014-07-01

Full Text Available Achieving magnetic recording densities in excess of 1Tbit/in2 requires not only perpendicular media with anisotropies larger than 7 MJ/m3, making FePt alloys an ideal choice, but also a narrow distribution below 10 nm for a reduced S/N ratio. Such grain size reduction and shape control are crucial parameters for high density magnetic recording, along with high thermal stability. Previous work has shown that the L10 FePt grain size can be controlled by alloying FePt with materials such as C, Ag, and insulators such as AlOx, MgO. Au and Al2O3 also act to segregate and magnetically decouple the FePt grains. Better results were obtained with C with respect to the uniformity of grains and SiO2 with respect to the shape. We present our results on co-sputtering FePt with C or SiO2 (up to 30 vol % on MgO (001 single crystal substrates at 350 and 500 oC. With C or SiO2 addition we achieved grain size reduction, shape control and isolated structure formation, producing continuous films with high uniformity and a narrow grain size distribution. These additions thus allow us to simultaneously control the coercivity and the S/N ratio. We also will report structural and microstructural properties.

Photo-Hall-effect study of excitation and recombination in Fe-doped GaN

Science.gov (United States)

Look, David C.; Leach, Jacob H.; Metzger, Robert

2017-02-01

The photo-Hall-effect was applied to the study of electron dynamics in semi-insulating Fe-doped GaN. High-powered light-emitting diodes of wavelengths λ = 940, 536, 449, 402, and 365 nm were used to excite steady-state free-electron volume concentrations Δn = 105-108 cm-3, depending on λ and intensity I0. Electron lifetime τ was determined from the energy E dependence of the excited sheet electron concentration Δns through the relationship Δns = I0τA(E), where the absorbance A(E) is a known function of sample thickness d and absorption coefficient α, and the energy dependence of α is taken from a theory of deep-center photoionization. The major sample impurities were Fe, Si, and C, with [Fe] ≫ [Si] and [C]. Fitted lifetimes τ ranged from 15 to 170 ps, depending on [Fe]. It was found that Δns ∝ I0 for [Si] > [C] and ∝ I01/2 for [Si] [C], some of the neutral Fe3+ is converted to Fe2+ with ground state Fe2+(5E) and excited state Fe2+(5T2); a fit of n vs. temperature T over the range of 290-325 K in the dark establishes E5E with respect to the conduction band: ECB - E5E = 0.564 eV - β5ET, where β5E = 3.6 × 10-4 eV/K. At room temperature, 294 K, ECB - E5E = 0.46 eV and ECB - E5T2 = 0.07 eV.

Luminescence and magnetic properties of novel nanoparticle-sheathed 3D Micro-Architectures of Fe0.5R0.5(MoO4)1.5:Ln3+ (R = Gd3+, La3+), (Ln = Eu, Tb, Dy) for bifunctional application

Science.gov (United States)

Krishnan, Rajagopalan; Thirumalai, Jagannathan; Kathiravan, Arunkumar

2015-01-01

For the first time, we report the successful synthesis of novel nanoparticle-sheathed bipyramid-like and almond-like Fe0.5R0.5(MoO4)1.5:Ln3+ (R = Gd3+, La3+), (Ln = Eu, Tb, Dy) 3D hierarchical microstructures through a simple disodium ethylenediaminetetraacetic acid (Na2EDTA) facilitated hydrothermal method. Interestingly, time-dependent experiments confirm that the assembly-disassembly process is responsible for the formation of self-aggregated 3D architectures via Ostwald ripening phenomena. The resultant products are characterized by x-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), high resolution transmission electron microscopy (HRTEM), photoluminescence (PL), and magnetic measurements. The growth and formation mechanisms of the self-assembled 3D micro structures are discussed in detail. To confirm the presence of all the elements in the microstructure, the energy loss induced by the K, L shell electron ionization is observed in order to map the Fe, Gd, Mo, O, and Eu components. The photo luminescence properties of Fe0.5R0.5(MoO4)1.5 doped with Eu3+, Tb3+, Dy3+ are investigated. The room temperature and low temperature magnetic properties suggest that the interaction between the local-fields introduced by the magnetic Fe3+ ions and the R3+ (La, Gd) ions in the dodecahedral sites determine the magnetism in Fe0.5R0.5(MoO4)1.5:Eu3+. This work provides a new approach to synthesizing the novel Fe0.5R0.5(MoO4)1.5:Ln3+ for bi-functional magnetic and luminescence applications.

77 FR 62150 - Approval and Promulgation of Implementation Plans; Kentucky; Approval of Revisions to the...

Science.gov (United States)

2012-10-12

....34 Standard of 10/23/01 66 FR 53661 05/15/91 Performance for Existing Pneumatic Rubber Tire... Abbreviations and 11/19/02 67 FR 69688 05/15/02 Acronyms. 1.04 Performance Tests... 10/23/01 66 FR 53660 11/19... 10/23/01 66 FR 53660 06/13/79 Requirements. Reg 6--Standards of Performance for Existing Affected...

On the synthesis, characterization, rationalization of the structure and the compositional formula of Ti-substituted Li0,5Fe2,5O4

International Nuclear Information System (INIS)

Widatallah, H.M.; Berry, F.J.; Moore, E.A.; Johnson, C.; Jartych, E.; Pekala, M.; Grabski, J.

2002-12-01

Spinel-related titanium-substituted Li 0.5 Fe 2.5 O 4 has been synthesised by heating a mixture of titanium-doped corundum-related α-Fe 2 O 3 with Li 2 CO 3 at 850 deg C which is ca. 250-350 deg C lower than temperatures at which the material is normally prepared conventionally. Moessbauer and magnetic measurements imply that the Ti 4+ ions substitute for octahedral Fe 3+ ions. Interatomic potential calculations support this substitution with the charge balance being maintained by Li + vacancies. This structural model leads to a compositional formula of the type Li (0.5-x) + Ti x 4+ Fe (2.5-x) 3+ O 4 which is shown to be more appropriate than the one generally used in the literature, namely Li (0.5+0.5x) + Ti x 4+ Fe (2.5-1.5x) 3+ O 4 . Some implications of the suggested formula are discussed including the possibility of the existence of a thermodynamically stable titanium ferrite of the form Ti 0.5 Fe 2 O 4 . (author)

Pressure-induced magnetic transition in Fe sub 4 N probed by Fe K-edge XMCD measurement

CERN Document Server

Ishimatsu, N; Maruyama, H; Kawamura, N; Suzuki, M; Ohishi, Y; Ito, M; Nasu, S; Kawakami, T

2003-01-01

X-ray magnetic circular dichroism (XMCD) of gamma'-iron nitride (Fe sub 4 N) was recorded at Fe K-edge under high pressure up to 27 GPa. The XMCD intensity decreased remarkably with pressure, and vanished at 24 GPa. Compressibility was measured by the X-ray diffraction method. These results indicate that Fe sub 4 N undergoes a second-order phase transition from the ferromagnetic state to a paramagnetic state without any structural change. The pressure-induced demagnetizing process is discussed in terms of the Fe magnetic states in the local environment.

Anisotropic thermal expansion of La(n)(Ti,Fe)(n)O(3n + 2) (n = 5 and 6).

Science.gov (United States)

Wölfel, Alexander; Dorscht, Philipp; Lichtenberg, Frank; van Smaalen, Sander

2013-04-01

Crystal structures are reported for two perovskite-related compounds with nominal compositions La5(Ti(0.8)Fe(0.2))5O17 and La6(Ti(0.67)Fe(0.33))6O20 at seven different temperatures between 90 and 350 K. For both compounds no evidence of a structural phase transition in the investigated range of temperatures was found. The thermal expansions are found to be anisotropic, with the largest thermal expansion along a direction parallel to the slabs of these layered compounds. The origin of this anisotropy is proposed to be a temperature dependence of tilts of the octahedral (Ti,Fe)O6 groups. It is likely that the same mechanism will determine similar anisotropic thermal behaviour of other compounds A(n)B(n)O(3n + 2). The crystal structures have revealed partial chemical order of Ti/Fe over the B sites, with iron concentrated towards the centers of the slabs. Local charge compensation is proposed as the driving force for the chemical order, where the highest-valent cation moves to sites near the oxygen-rich borders of the slabs. A linear dependence on the site occupation fraction by Fe of the computed valences leads to extrapolated valence values close to the formal valence of Ti(4+) for sites fully occupied by Ti, and of Fe(3+) for sites fully occupied by Fe. These results demonstrate the power of the bond-valence method, and they show that refined oxygen positions are the weighted average of oxygen positions in TiO6 and FeO6 octahedral groups.

Remoción de Fe y Mn en aguas naturales por adsorción-oxidación sobre clinoptilolita

Directory of Open Access Journals (Sweden)

Carolina Cuchimaque Lugo

2013-01-01

Full Text Available En el presente trabajo de investigación se comprueba la eficiencia en la remoción de Fe y Mn de aguas naturales por el empleo de un medio adsorbente que consiste de zeolita natural (clinoptilolita, recubierta con Fe 2O3 y MnO2 a partir de FeCl3 y MnSO4, respectivamente. La zeolita por su gran capacidad de intercambio de cationes es un excelente soporte de estos óxidos. El mecanismo de la remoción es por adsorción-oxidación de estos metales sobre la superficie de la capa de óxido que cubre el grano de zeolita. En las pruebas de remoción mediante un sistema de filtración se estudiaron las variables pH, concentraciones de Fe y Mn, caudal en el a fluente y altura de la capa de la zeolita, resultando las dos últimas ser las de mayor relevancia en la remoción. Se utilizaron concentraciones de 1,0-7,0 mg/L para Fe y de 0,5-3,0 mg/L para Mn, en un rango de pH de 6,0-8,0. La eficiencia de la remoción disminuye con el aumento en la concentración de Fe, especialmente a valores de pH altos (> 7,5, por la formación de precipitados de Fe2O3 causando aceleración en la saturación del medio. No se obtuvo una diferencia significativa sobre la remoción con el empleo de los dos tipos de recubrimiento, aunque a altas concentraciones de estos metales, con la capa de Fe 2O3 se obtuvieron porcentajes de remoción un poco mayores, pero la desventaja es que con este tipo de óxido se obtuvo menor corrida de los filtros por la saturación del medio.

78 FR 14095 - Determination That GEREF (Sermorelin Acetate) Injection, 0.5 Milligrams Base/Vial and 1.0...

Science.gov (United States)

2013-03-04

...] Determination That GEREF (Sermorelin Acetate) Injection, 0.5 Milligrams Base/Vial and 1.0 Milligrams Base/Vial, and GEREF (Sermorelin Acetate) Injection, 0.05 Milligrams Base/Amp, Were Not Withdrawn From Sale for...

A system for ubiquitous health monitoring in the bedroom via a Bluetooth network and wireless LAN.

Science.gov (United States)

Choi, J M; Choi, B H; Seo, J W; Sohn, R H; Ryu, M S; Yi, W; Park, K S

2004-01-01

Advances in information technology have enabled ubiquitous health monitoring at home, which is particularly useful for patients, who have to live alone. We have focused on the automatic and unobtrusive measurement of biomedical signals and activities of patients. We have constructed wireless communication networks in order to transfer data. The networks consist of Bluetooth and Wireless Local Area Network (WLAN). In this paper, we present the concept of a ubiquitous-Bedroom (u-Bedroom) which is a part of a ubiquitous-House (u-House) and we present our systems for ubiquitous health monitoring.

Enhancing pitting corrosion resistance of AlxCrFe1.5MnNi0.5 high-entropy alloys by anodic treatment in sulfuric acid

International Nuclear Information System (INIS)

Lee, C.P.; Chen, Y.Y.; Hsu, C.Y.; Yeh, J.W.; Shih, H.C.

2008-01-01

High-entropy alloys are a newly developed family of multi-component alloys that comprise various major alloying elements. Each element in the alloy system is present in between 5 and 35 at.%. The crystal structures and physical properties of high-entropy alloys differ completely from those of conventional alloys. The electrochemical impedance spectra (EIS) of the Al x CrFe 1.5 MnNi 0.5 (x = 0, 0.3, 0.5) alloys, obtained in 0.1 M HCl solution, clearly revealed that the corrosion resistance values were determined to increase from 21 to 34 Ωcm 2 as the aluminum content increased from 0 to 0.5 mol, and were markedly lower than that of 304 stainless steel (243 Ωcm 2 ). At passive potential, the corresponding current declined with the anodizing time accounting, causing passivity by the growth of the multi-component anodized film in H 2 SO 4 solution. X-ray photoelectron spectroscopy (XPS) analyses revealed that the surface of anodized Al 0.3 CrFe 1.5 MnNi 0.5 alloy formed aluminum and chromium oxide film which was the main passivating compound on the alloy. This anodic treatment increased the corrosion resistance in the EIS measurements of the CrFe 1.5 MnNi 0.5 and Al 0.3 CrFe 1.5 MnNi 0.5 alloys by two orders of magnitude. Accordingly, the anodic treatment of the Al x CrFe 1.5 MnNi 0.5 alloys optimized their surface structures and minimized their susceptibility to pitting corrosion

N2O decomposition over Fe/ZSM-5: reversible generation of highly active cationic Fe species

NARCIS (Netherlands)

Zhu, Q.; Hensen, E.J.M.; Mojet, B.L.; Wolput, van J.H.M.C.; Santen, van R.A.

2002-01-01

Fe-oxide species in Fe/ZSM-5 (prepared by chemical vapor deposition of FeCl3)-active in N2O decomposition-react with zeolite protons during high temperature calcination to give highly active cationic Fe species, this transformation being reversible upon exposure to water vapor at lower temperature

Neutron capture resonances in 56Fe and 58Fe in the energy range from 10 to 100 keV

International Nuclear Information System (INIS)

Kaeppeler, F.; Wisshak, K.; Hong, L.D.

1982-11-01

The neutron capture cross section of 56 Fe and 58 Fe has been measured in the energy range from 10 to 250 keV relative to the gold standard. A pulsed 3 MV Van de Graaff accelerator and the 7 Li(p, n) reaction served as a neutron source. Capture gamma rays were detected by two C 6 D 6 detectors, which were operated in coincidence and anticoincidence mode. Two-dimensional data acquisition allowed to apply the pulse height weighting technique off-line. The samples were located at a flight path of 60 cm. The total time resolution was 1.2 ns thus allowing for an energy resolution of 2 ns/m. The experimental set-up was optimized with respect to low background and low neutron sensitivity. The additional flight path of 4 cm from the sample to the detector was sufficient to discriminate capture of sample scattered neutrons by the additional time of flight. In this way reliable results were obtained even for the strong s-wave resonances of both isotopes. The experimental capture yield was analyzed with the FANAC code. The energy resolution allowed to extract resonance parameters in the energy range from 10 to 100 keV. The individual systematic uncertainties of the experimental method are discussed in detail. They were found to range between 5 and 10% while the statistical uncertainty is 3-5% for most of the resonances. A comparison to the results of other authors exhibits in case of 56 Fe systematic differences of 7-11%. For 58 Fe the present results differ up to 50% from the only other measurement for this isotope. (orig.) [de

Characterization of High Dose Mn, Fe, and Ni implantation into p-GaN

CERN Document Server

Pearton, S J; Thaler, G; Abernathy, C R; Theodoropoulou, N; Hebard, A F; Chu, S N G; Wilson, R G; Zavada, J M; Polyakov, A Y; Osinsky, A V; Norris, P E; Chow, P P; Wowchack, A M; Hove, J M V; Park, Y D

2002-01-01

The magnetization of p-GaN or p-AlGaN/GaN superlattices was measured after implantation with high doses (3-5x10 sup 1 sup 6 cm sup - sup 2) of Mn, Fe, or Ni and subsequent annealing at 700-1000 deg. C. The samples showed ferromagnetic contributions below temperatures ranging from 190-250 K for Mn to 45-185 K for Ni and 80-250 K for Fe. The use of superlattices to enhance the hole concentration did not produce any change in ferromagnetic ordering temperature. No secondary phase formation was observed by x-ray diffraction, transmission electron microscopy, or selected area diffraction pattern analysis for the doses we employed.

Extreme Field Sensitivity of Magnetic Tunneling in Fe-Doped Li_{3}N.

Science.gov (United States)

Fix, M; Atkinson, J H; Canfield, P C; Del Barco, E; Jesche, A

2018-04-06

The magnetic properties of dilute Li_{2}(Li_{1-x}Fe_{x})N with x∼0.001 are dominated by the spin of single, isolated Fe atoms. Below T=10  K the spin-relaxation times become temperature independent indicating a crossover from thermal excitations to the quantum tunneling regime. We report on a strong increase of the spin-flip probability in transverse magnetic fields that proves the resonant character of this tunneling process. Longitudinal fields, on the other hand, lift the ground-state degeneracy and destroy the tunneling condition. An increase of the relaxation time by 4 orders of magnitude in applied fields of only a few milliTesla reveals exceptionally sharp tunneling resonances. Li_{2}(Li_{1-x}Fe_{x})N represents a comparatively simple and clean model system that opens the possibility to study quantum tunneling of the magnetization at liquid helium temperatures.

Temperature-dependent transformation of the magnetic excitation spectrum on approaching superconductivity in Fe(1+y-x)(Ni/Cu)(x)Te(0.5)Se(0.5).

Science.gov (United States)

Xu, Zhijun; Wen, Jinsheng; Zhao, Yang; Matsuda, Masaaki; Ku, Wei; Liu, Xuerong; Gu, Genda; Lee, D-H; Birgeneau, R J; Tranquada, J M; Xu, Guangyong

2012-11-30

Spin excitations are one of the top candidates for mediating electron pairing in unconventional superconductors. Their coupling to superconductivity is evident in a large number of systems, by the observation of an abrupt redistribution of magnetic spectral weight at the superconducting transition temperature, T(c), for energies comparable to the superconducting gap. Here we report inelastic neutron scattering measurements on Fe-based superconductors, Fe(1+y-x)(Ni/Cu)(x)Te(0.5)Se(0.5) that emphasize an additional signature. The overall shape of the low energy magnetic dispersion changes from two incommensurate vertical columns at T≫T(c) to a distinctly different U-shaped dispersion at low temperature. Importantly, this spectral reconstruction is apparent for temperatures up to ~3T(c). If the magnetic excitations are involved in the pairing mechanism, their surprising modification on the approach to T(c) demonstrates that strong interactions are involved.

NEW WAYS TO DEVELOP AND PPROMOT TOURISM THROUGH RESTORATION OF WOODEN CHURCHES FROM BUZAU REGION

Directory of Open Access Journals (Sweden)

Elena-Teodora, NECULA

2014-11-01

Full Text Available With highlighting of the wooden churches from the sub-Carpathian region is possible to make projects of development and promovation of tourism in Buzau. Publishing a book of the wooden churches witch presents the overview on architecture helps with the prom ovation of tourism by bringing new light on the full set, geographical specking it brings new territory to view. Advantage by placing wooden churches in the vicinity of hermitage caves from Buzau will attract even more interest of the large public for seed region. Realizing a few projects of conservation-restoration of wooden churches which are declared historical monuments, will bring a local developing from a cultural-tourist view. A particular case is the wooden church "Saints Emperors" from the vicinity city Nehoiu which has ruttier access, helps with the cost for restoration and number of viewers. Through realizing interventions of conservation-restoration and placing it in a favorable aesthetic view, the monument can be used in a cultural-tourist circuit of international important and this way it can help with the growth of value of monuments and developing cultural-tourist with the final scope heightening the economy.

ICORG 10-14

DEFF Research Database (Denmark)

Reynolds, J V; Preston, S R; O'Neill, B

2017-01-01

comprehensive modern staging, compares both these regimens. METHODS: This open label, multicentre, phase III RCT randomises patients (cT2-3, N0-3, M0) in a 1:1 fashion to receive CROSS protocol (Carboplatin and Paclitaxel with concurrent radiotherapy, 41.4Gy/23Fr, over 5 weeks). The power calculation is a 10......% difference in favour of CROSS, powered at 80%, two-sided alpha level of 0.05, requiring 540 patients to be evaluable, 594 to be recruited if a 10% dropout is included (297 in each group). The primary endpoint is overall survival, with a minimum 3-year follow up. Secondary endpoints include: disease free......). TRIAL REGISTRATION: NCT01726452 . Protocol 10-14. Date of registration 06/11/2012....

Charge disproportionation in Fe/sup 4 + -/oxides with perovskite-type structures

Energy Technology Data Exchange (ETDEWEB)

Takano, M; Nakanishi, N [Konan Univ., Kobe (Japan). Faculty of Science; Takeda, Y; Naka, S [Nagoya Univ. (Japan)

1979-01-01

For a further examination and elaboration of our simple charge disproportionation model for Fe/sup 4 +/-oxides, 2Fe/sup 4 +/..-->..Fe/sup 3 +/ + Fe/sup 5 +/, two series of solid solutions Casub(1-x)Srsub(x)FeO/sub 3/ and Srsub(1-x)Lasub(x)FeO/sub 3/ with the perovskite structure have been studied. The Moessbauer spectrum of Srsub(0,5)Lasub(0.5)FeO/sub 3/ at 4 K clearly indicates the disproportionation. For both series of oxides, the disproportionation seems to set in at the Tsub(N).

Morphology effect on photocatalytic activity in Bi3Fe0.5Nb1.5O9

Science.gov (United States)

Yin, Xiaofeng; Li, Xiaoning; Gu, Wen; Zou, Wei; Liu, Huan; Zhu, Liuyang; Fu, Zhengping; Lu, Yalin

2018-06-01

In this work, the Aurivillius-phase ferroelectric Bi3Fe0.5Nb1.5O9 were synthesized by hydrothermal (BFNO-H) and solid state methods (BFNO-S), respectively. The BFNO-H shows a hierarchical morphology, which is stacked by intersecting single-crystal nanosheets with {001} and {110} exposed facets, while the BFNO-S shows disorganized micron-scale morphology. BFNO-H shows a much stronger photodegradation activity (10.4 times and 9.8 times) than BFNO-S in the visible-light photodegradation of rhodamine B (RhB) and salicylic acid. The higher photodegradation activity of BFNO-H was firstly ascribed to the hierarchical structure and the larger specific surface area (16.586 m2 g‑1) because a large specific surface area can increase reactive sites and shorten photogenerated carrier migration distance. However, after being normalized by the specific surface area, BFNO-H still performs better than BFNO-S, implying that the specific surface area is not the only factor that determines the photocatalytic activity. Considering that the built-in electric field originating from spontaneous polarization in Bi3Fe0.5Nb1.5O9 has existed in both ab plane and c direction, it matches well with the {001} and {110} exposed facets of BFNO-H nanosheets. This appropriate matching in BFNO-H nanosheets may improve the separation and transmission of photogenerated electron–hole pairs and further enhance its photocatalytic activity. Moreover, the trapping experiments reveals that holes (h +) are the main active species and hole-derived oxidation is the main redox reaction during photodegradation of organic pollutions.

Investigation of structural and magnetic properties of Ni{sub 0.5}Zn{sub 0.5}Fe{sub 2}O{sub 4} nano powders prepared by self combustion method

Energy Technology Data Exchange (ETDEWEB)

Sudheesh, V.D.; Nehra, J.; Vinesh, A. [Department of Physics, Mohanlal Sukhadia University, Udaipur 313001, Rajasthan (India); Sebastian, V. [Department of Physics, Nirmalagiri College, Kuthuparamba 670701, Kerala (India); Lakshmi, N., E-mail: nambakkat@yahoo.com [Department of Physics, Mohanlal Sukhadia University, Udaipur 313001, Rajasthan (India); Dutta, Dimple P. [Chemistry Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Reddy, V.R. [UGC-DAE CSR, University Campus, Khandwa Road, Indore 452001, M.P. (India); Venugopalan, K. [Department of Physics, Mohanlal Sukhadia University, Udaipur 313001, Rajasthan (India); Gupta, Ajay [UGC-DAE CSR, University Campus, Khandwa Road, Indore 452001, M.P. (India)

2013-02-15

Graphical abstract: Display Omitted Highlights: ► Ni{sub 0.5}Zn{sub 0.5}Fe{sub 2}O{sub 4} prepared by self combustion with uniform/nonuniform heating. ► Characterized using TEM, XRD, in-field Mössbauer and DC magnetometry. ► Leads to bimodal (S1) and very narrow size distribution (S2) type nano samples. ► S1 has magnetic properties of bulk Ni{sub 0.5}Zn{sub 0.5}Fe{sub 2}O{sub 4}. ► Although very even sized, S2 large magnetic anisotropy distribution. -- Abstract: Nano powders of Ni{sub 0.5}Zn{sub 0.5}Fe{sub 2}O{sub 4} have been synthesized by the self-combustion method at a relatively low temperature of 473 K under conditions of non-uniform and uniform heating. Rietveld fitting of X-ray diffractograms confirm the formation of the pure spinel phase in both samples. Transmission electron microscopy indicates that the sample prepared under non-uniform heating has a bimodal particle size distribution (average values 16 nm and 6 nm) while the one prepared under uniform heating has a very narrow particle size distribution (average size 4 nm). Low temperature, in-field Mössbauer spectroscopic studies clearly show surface spin contributions. The hyperfine fields and Curie temperature of the non-uniformly heated sample are in good agreement with those reported for the corresponding bulk samples. Despite having a very narrow particle size distribution, the uniformly heated sample has a large anisotropy distribution which is evident in the broad transition visible in the temperature dependent magnetization curve. It is also corroborated by the fact that the experimental magnetization curve at room temperature requires two Langevin functions for satisfactory reproduction.

PUPILS’ AND STUDENTS’ PERCEPTIONS AND REPRESENTATIONS OF THE WOODEN CHURCHES IN MARAMUREŞ, ROMANIA

Directory of Open Access Journals (Sweden)

SORIN-ALIN KOSINSZKI

2013-01-01

Full Text Available The main objective of the research was to study the perceptions and representations of some pupils and students, living in Maramureş, of the wooden churches from Maramureş and their employment as tourist attractions. The specific objectives of this research were the following: conceiving, analysing and applying a research instrument for the perceptions and representations on the wooden churches from Maramureş and their employment as tourist attractions, the analysis and interpretation of the obtained results. The following research hypothesis was tested: pupils and students do not have very precise representations of the wooden churches in Maramureş and their employment as tourist attractions. After the questionnaire was applied and the results were analyzed, the working hypothesis was confirmed.

Microstructure and Tribological Properties of AlCoCrFeNiTi0.5 High-Entropy Alloy in Hydrogen Peroxide Solution

Science.gov (United States)

Yu, Y.; Liu, W. M.; Zhang, T. B.; Li, J. S.; Wang, J.; Kou, H. C.; Li, J.

2014-01-01

Microstructure and tribological properties of an AlCoCrFeNiTi0.5 high-entropy alloy in high-concentration hydrogen peroxide solution were investigated in this work. The results show that the sigma phase precipitates and the content of bcc2 decrease during the annealing process. Meanwhile, the complex construction of the interdendrite region changes into simple isolated-island shape, and much more spherical precipitates are formed. Those changes of microstructure during the annealing process lead to the increase of hardness of this alloy. In the testing conditions, the AlCoCrFeNiTi0.5 alloy shows smoother worn surfaces and steadier coefficient of friction curves than does the 1Cr18Ni9Ti stainless steel, and SiC ceramic preserves better wear resistance than ZrO2 ceramic. After annealing, the wear resistance of the AlCoCrFeNiTi0.5 alloy increases coupled with SiC counterface but decreases with ZrO2 counterface.

Oxidative Stress and Metabolic Perturbations in Wooden Breast Disorder in Chickens.

Directory of Open Access Journals (Sweden)

Behnam Abasht

Full Text Available This study was conducted to characterize metabolic features of the breast muscle (pectoralis major in chickens affected with the Wooden Breast myopathy. Live birds from two purebred chicken lines and one crossbred commercial broiler population were clinically examined by manual palpation of the breast muscle (pectoralis major at 47-48 days of age. Metabolite abundance was determined by gas chromatography/mass spectrometry (GC/MS and liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS using breast muscle tissue samples from 16 affected and 16 unaffected chickens. Muscle glycogen content was also quantified in breast muscle tissue samples from affected and unaffected chickens. In total, levels of 140 biochemicals were significantly different (FDR1.3 or <0.77 between affected and unaffected chickens. Glycogen content measurements were considerably lower (1.7-fold in samples taken from Wooden Breast affected birds when compared with samples from unaffected birds. Affected tissues exhibited biomarkers related to increased oxidative stress, elevated protein levels, muscle degradation, and altered glucose utilization. Affected muscle also showed elevated levels of hypoxanthine, xanthine, and urate molecules, the generation of which can contribute to altered redox homeostasis. In conclusion, our findings show that Wooden Breast affected tissues possess a unique metabolic signature. This unique profile may identify candidate biomarkers for diagnostic utilization and provide mechanistic insight into altered biochemical processes contributing to tissue hardening associated with the Wooden Breast myopathy in commercial chickens.

Association between electronic equipment in the bedroom and sedentary lifestyle, physical activity, and body mass index of children

OpenAIRE

Ferrari, Gerson Luis de Moraes; Araújo, Timóteo Leandro; Oliveira, Luis Carlos; Matsudo, Victor; Fisberg, Mauro

2015-01-01

Objective: To describe the association between electronic devices in the bedroom with sedentary time and physical activity, both assessed by accelerometry, in addition to body mass index in children from São Caetano do Sul. Methods: The sample consisted of 441 children. The presence of electronic equipment (television, personal computer, and videogames) in the bedroom was assessed by a questionnaire. For seven consecutive days, children used an accelerometer to objectively monitor the sede...

Structural and Mössbauer studies of nanocrystalline Mn{sup 4+}-doped Li{sub 0.5}Fe{sub 2.5}O{sub 4} particles prepared by mechanical milling

Energy Technology Data Exchange (ETDEWEB)

Widatallah, H. M., E-mail: hishammw@squ.edu.om; Al-Mabsali, F. N.; Al-Hajri, F. S. [Sultan Qaboos University, Physics Department, College of Science (Oman); Khalifa, N. O. [University of Khartoum, Physics Department, Faculty of Science (Sudan); Gismelseed, A. M.; Al-Rawas, A. D.; Elzain, M.; Yousif, A. [Sultan Qaboos University, Physics Department, College of Science (Oman)

2016-12-15

The structure and magnetic properties of spinel-related Mn{sup 4+}-doped Li{sub 0.5}Fe{sub 2.5}O{sub 4} nanocrystalline particles of the composition Li{sub 0.5}Fe{sub 2.25}Mn{sub 0.1875}O{sub 4}, prepared by milling a pristine sample for different times, were investigated. The average crystallite and particle size, respectively, decreased form ∼40 nm to ∼10 nm and ∼2.5 μm to ∼10 nm with increasing milling time from 0 h to 70 h. Rietveld refinement of the XRD data of the non-milled sample show the Mn{sup 4+} dopant ions to substitute for Fe{sup 3+} at the octahedral B-sites of the spinel-related structure. The Mössbauer spectra of the milled ferrites indicate that more particles turn superparamagnetic with increasing milling time. The Mössbauer data collected at 78 K suggest that while in the non-milled sample the Mn{sup 4+} ions substitute for Fe{sup 3+} at the octahedral B-sites, this is reversed as milling proceeds with doped Mn{sup 4+} ions, balancing Fe{sup 3+} vacancies and possibly Li{sup +} ions progressively migrate to the tetrahedral A-sites. This is supported by the slight increase observed in the magnetization of the milled samples relative to that of the non-milled one. The magnetic data suggest that in addition to the increasing superparamagentic component of the milled particles, thermal spin reversal and/or spin canting effects are possible at the surface layers of the nanoparticles.

Effects of exposure to 56Fe particles of protons on fixed-ratio operant responding in rats

International Nuclear Information System (INIS)

Rabin, B.M.; Buhler, L.L.; Jenkins, D.G.; Joseph, J.A.; Shukitt-Hale, B.

2002-01-01

On long-duration trips outside of the magnetosphere, astronauts will be exposed to protons and to heavy particles which can affect their performance of required tasks. It is essential to determine the range of behaviors that might be affected by exposure to these types of radiation in order to understand the nature of behavioral deficits and to develop effective countermeasures. The present experiment examined the ability of rats to make an operant response following exposure to protons (250 MeV, 4 Gy) or 56 Fe particles (1 GeV/n, 1 or 2 Gy). Following irradiation, rats were trained to press a lever in order to obtain food reinforcement. They were then placed on an ascending fixed-ratio schedule from FR-1 (each lever press rewarded with a food pellet) through FR-35 (35 lever presses required for 1 food pellet). Rats exposed to 4 Gy of protons or 1 Gy of 56 Fe particles responded similarly to controls, increasing their rate of responding as the ratio increased. However, rats exposed to 2 Gy of 56 Fe particles failed to increase their rate of responding at ratios greater than FR-20, indicating that rats exposed to 2 Gy of 56 Fe particles cannot respond appropriately to increasing work requirements. (author)

PRODUCCIÓN DE UNA ALEACIÓN NANOESTRUCTURADA FeAl MEDIANTE ALEACIÓN MECÁNICA Y SU CARACTERIZACIÓN MICROESTRUCTURAL

Directory of Open Access Journals (Sweden)

Roberto. A. Rodríguez-Díaz

2013-01-01

Full Text Available En este trabajo se elaboró la aleación Fe40Al mediante la técnica de aleación mecánica (AM a partir de una mezcla de polvos elementales de Fe y Al, empleando distintos tiempos de molienda. Se caracterizó la evolución en tamaño y morfología de los polvos empleados en el proceso de AM en función del tiempo de molienda mediante la técnica de Microscopía Electrónica de Barrido (MEB. Se empleó la técnica de Difracción de Rayos X (DRX para caracterizar la evolución de la estructura cristalina de las fases obtenidas en función del tiempo de molienda. La aleación Fe40Al con estructura cristalina desordenada del tipo cúbico centrado en el cuerpo se formó a las 20 h de molienda. El tamaño nano-métrico de grano correspondiente a la aleación desordenada Fe40Al se redujo con el transcurso del tiempo mientras que su parámetro de red se incrementó con el transcurso del tiempo de molienda.

Modeling ventilation rates in bedrooms based on building characteristics and occupant behavior

DEFF Research Database (Denmark)

Bekö, Gabriel; Toftum, Jørn; Clausen, Geo

2011-01-01

Air change rate (ACR) data obtained from the bedrooms of 500 Danish children and presented in an earlier paper were analyzed in more detail. Questionnaires distributed to the families, home inspections and interviews with the parents provided information about a broad range of residential charact...

A Comparison between the Effects of Aerobic Dance Training on Mini-Trampoline and Hard Wooden Surface on Bone Resorption, Health-Related Physical Fitness, Balance, and Foot Plantar Pressure in Thai Working Women.

Science.gov (United States)

Sukkeaw, Wittawat; Kritpet, Thanomwong; Bunyaratavej, Narong

2015-09-01

To compare the effects of aerobic dance training on mini-trampoline and hard wooden surface on bone resorption, health-related physical fitness, balance, and foot plantar pressure in Thai working women. Sixty-three volunteered females aged 35-45 years old participated in the study and were divided into 3 groups: A) aerobic dance on mini-trampoline (21 females), B) aerobic dance on hard wooden surface (21 females), and C) control group (21 females). All subjects in the aerobic dance groups wore heart rate monitors during exercise. Aerobic dance worked out 3 times a week, 40 minutes a day for 12 weeks. The intensity was set at 60-80% of the maximum heart rate. The control group engaged in routine physical activity. The collected data were bone formation (N-terminal propeptine of procollagen type I: P1NP) bone resorption (Telopeptide cross linked: β-CrossLaps) health-related physical fitness, balance, and foot plantar pressure. The obtained data from pre- and post trainings were compared and analyzed by paired samples t-test and one way analysis of covariance. The significant difference was at 0.05 level. After the 12-week training, the biochemical bone markers of both mini-trampoline and hard wooden surface aerobic dance training subjects decreased in bone resorption (β-CrossLaps) but increased in boneformation (P1NP). Health-related physical fitness, balance, and foot plantar pressure were not only better when comparing to the pre-test result but also significantly different when comparing to the control group (p trampoline showed that leg muscular strength, balance and foot plantar pressure were significantly better than the aerobic dance on hard wooden surface (p trampoline and hard wooden surface had positive effects on biochemical bone markers. However, the aerobic dance on mini-trampoline had more leg muscular strength and balance including less foot plantar pressure. It is considered to be an appropriate exercise programs in working women.

Study of Zr{sub x}Zn{sub 0.5−x}Ni{sub 0.5}Fe{sub 2}O{sub 4} 0≤x≤0.25: Synthesis, structural, magnetic and electrical properties

Energy Technology Data Exchange (ETDEWEB)

Saini, Jasmeen; Kumar, Rupesh [Nanotechnology Research Centre, DAV Institute of Engineering and Technology, Jalandhar 144008 (India); Rajput, Jaspreet Kaur [Department of Chemistry, Dr. B.R. Ambedkar National Institute of Technology, Jalandhar 144011 (India); Kumar, Arvind [Department of Electronics and Communication, UIET, Panjab University, Chandigarh 160025 (India)

2016-03-01

Zirconium substituted zinc–nickel ferrite nanoparticles with chemical composition of Zr{sub x}Zn{sub 0.5−x}Ni{sub 0.5}Fe{sub 2}O{sub 4} (0≤x≤0.25) have been synthesized successfully by solution combustion method using high purity nitrates and fueling agent urea. Powder XRD study confirms the single phase formation of composite ferrite which belongs to cubic spinel structure. TEM further reveals the morphology of well dispersed Zn–Ni ferrite nanoparticles to be spherical. Effect of change of doping concentration of Zirconium is observed using FTIR. The saturation magnetization gradually decreases with the increase in Zr substitution and reaches minimum when x=0.25 whereas the coercivity value reaches minimum when x=0.15. DC electrical resistivity has been found to vary with increasing Zr content. The good electrical resistivity (>10{sup 7} Ωcm) qualify the ceramic for high frequency transformer applications. - Graphical abstract: Zr Doped Zn–Ni Ferrite nanoparticles. - Highlights: • Zr{sub x}Zn{sub 0.5-x}Ni{sub 0.5}Fe{sub 2}O{sub 4} nanoparticles were synthesized by solution combustion method. • Increase in doping concentration of Zirconium reduces the grain size of the nanoparticles. • Very low value of coercivity (0.73 Oe to 137.34 Oe) obtained for such particles indicates that the material is soft magnet. • High resistivity (90 MΩcm to 845 MΩcm) was obtained that qualified the material for high frequency and power supply transformers applications.

The first study of antiferromagnetic eosphorite-childrenite series (Mn{sub 1−x}Fe{sub x})AlP(OH){sub 2}H{sub 2}O (x=0.5)

Energy Technology Data Exchange (ETDEWEB)

Behal, D. [Sektion Kristallographie, Department für Geo- und Umweltwissenschaften, Ludwig-Maximilians-Universität München (LMU), Theresienstrasse 41, D-80333 Munich (Germany); Forschungsneutronenquelle Heinz Maier-Leibnitz (FRM II), Technische Universität München (TUM), Lichtenbergstrasse 1, D-85748 Garching (Germany); Röska, B. [Sektion Kristallographie, Department für Geo- und Umweltwissenschaften, Ludwig-Maximilians-Universität München (LMU), Theresienstrasse 41, D-80333 Munich (Germany); Park, S.-H., E-mail: sohyun.park@lmu.de [Sektion Kristallographie, Department für Geo- und Umweltwissenschaften, Ludwig-Maximilians-Universität München (LMU), Theresienstrasse 41, D-80333 Munich (Germany); Pedersen, B. [Forschungsneutronenquelle Heinz Maier-Leibnitz (FRM II), Technische Universität München (TUM), Lichtenbergstrasse 1, D-85748 Garching (Germany); Benka, G.; Pfleiderer, Ch. [Chair E21, Physik-Department, Technische Universität München (TUM), James-Franck-Strasse 1, D-85748 Garching (Germany); Wakabayashi, Y.; Kimura, T. [Division of Materials Physics, Graduate School of Engineering Science, Osaka University, Toyonaka 560-8531 (Japan)

2017-04-15

This study presents for the first time the antiferromagnetic structure of the eosphorite-childrenite series (Mn{sub 1-x}Fe{sub x})AlPO{sub 4}(OH){sub 2}H{sub 2}O (x=0.5), based on neutron single crystal diffraction at 3 K in combination with group theoretical representation analysis. The new magnetic structure is described in the magnetic space group P{sub C}mnb, maintaining the atomistic unit cell size (a×b×c) with a ~6.9 Å, b ~10.4 Å, c ~13.4 Å. Mn-rich and Fe-rich zones within solid solution crystals are expanded up to several hundred micrometers, as seen in electron microprobe and polarisation microscopy. Magnetic susceptibility and specific heat measurements on two different eosphorite-childrenite crystals show the magnetic transition temperature between 6.5 K and 6.8 K as the Mn{sup 2+}/Fe{sup 2+} ratio varies over single compositional zones. Below the Néel temperature, a magnetic field between 1.5 T and 2 T parallel to the a-axis causes a 180° spin-flip, reaching the saturation (5.25 μ{sub B} pfu) toward high magnetic fields. - Highlights: • New magnetic structure of (Mn{sub 1-x}Fe{sub x})AlPO{sub 4}(OH){sub 2}H{sub 2}O (x=0.5). • Magnetic phase transition at 6.5–6.6 K. • Magnetic interaction anisotropy in (Mn{sub 0.5}Fe{sub 0.5})AlPO{sub 4}(OH){sub 2}H{sub 2}O. • Compositional zones in the eosphorite-childrenite series.

Transorbital impalement by a wooden stick in a 3-year-old child

DEFF Research Database (Denmark)

Damm, Anders; Lauritsen, Anne Øberg; Klemp, Kristian

2015-01-01

We present a case of a 3-year-old girl with a transorbital impalement injury due to a wooden stick penetrating the lower inferior palpebra and progressing through the orbita, after the child jumped from a table and hit a wooden basket containing pieces of exposed stick. CT revealed the stick prog...... and discharged 2 days later. Follow-up examination 2 months after the trauma demonstrated normal visual acuity and ocular motility, with no diplopia, tearing or pain....

Evaluation of consumers' choice of wooden dining furniture in ...

African Journals Online (AJOL)

USER

2010-05-24

May 24, 2010 ... the Nigeria furniture industry though operating at abysmal performance has been ... placed the number of major wooden furniture industry in. *Corresponding author. ..... Demand complementarities, retail assortments and the ...

2-Hydro-4-n-But oxypropiophenone Oxime as a spectrophotometric reagent for Fe (III)

International Nuclear Information System (INIS)

Purohit, K.; Desai, K.K.

2006-01-01

2-Hydro-4-n-But oxypropiophenone Oxime [Hipbone] has been synthesized and used for the spectrophotometric determination of Fe (III). The reagent gives purple coloured complex with Fe (III) in 50% alcoholic medium in pH range of 2.5-4.5. Beer's law is obeyed up to 23.1 ppm of Fe (III). Molar absorptivity and sandell's sensitivity at 500 nm of complex were found to be 7.062x 10 power2 lit.mol.cm and 0.079 ug of Fe (III)/cm respectively. Composition and stability constant have been determined. The reagent is successfully used for determination of Fe (III) in dolomite and in pharmaceutical sample. It is also used for the indirect determination of fluoride in tap water sample. (author)

Association between electronic equipment in the bedroom and sedentary lifestyle, physical activity, and body mass index of children

Directory of Open Access Journals (Sweden)

Gerson Luis de Moraes Ferrari

2015-11-01

Full Text Available Objective: To describe the association between electronic devices in the bedroom with sedentary time and physical activity, both assessed by accelerometry, in addition to body mass index in children from São Caetano do Sul. Methods: The sample consisted of 441 children. The presence of electronic equipment (television, personal computer, and videogames in the bedroom was assessed by a questionnaire. For seven consecutive days, children used an accelerometer to objectively monitor the sedentary time and moderate-to-vigorous physical activity. Body mass index was categorized as suggested by the World Health Organization. Results: Overall, 73.9%, 54.2% and 42.8% of children had TV, computer, and videogames in the bedroom, respectively, and spent an average of 500.7 and 59.1 min/day of sedentary time and moderate-to-vigorous physical activity. Of the children, 45.3% were overweight/obese. Girls with a computer in the bedroom (45 min/day performed less moderate-to-vigorous physical activity than those without it (51.4 min/day. Similar results were observed for body mass index in boys. Moderate-to-vigorous physical activity was higher and body mass index was lower in children that had no electronic equipment in the bedroom. Presence of a computer (β = −4.798 and the combination TV + computer (β = −3.233 were negatively associated with moderate-to-vigorous physical activity. Videogames and the combinations with two or three electronic devices were positively associated with body mass index. Sedentary time was not associated with electronic equipment. Conclusion: Electronic equipment in the children's bedroom can negatively affect moderate-to-vigorous physical activity and body mass index regardless of gender, school, and annual family income, which can contribute to physical inactivity and childhood obesity. Resumo: Objetivo: Descrever a associação entre equipamentos eletrônicos no quarto com tempo sedentário e atividade f

Modification of the ferrite load Ni{sub 0,5}Zn{sub 0,5}Fe{sub 2}O{sub 3} by silane agent for improving the interface in the absorbing composite; Modificacao da carga de ferrita Ni{sub 0,5}Zn{sub 0,5}Fe{sub 2}O{sub 3} por agente silano para melhoria da interface no composito absorvedor