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Sample records for borate retention wood

  1. Wood retention and transport in tropical, headwater streams, La Selva Biological Station, Costa Rica

    Science.gov (United States)

    Cadol, Daniel; Wohl, Ellen

    2010-11-01

    Wood in tropical streams has the potential to be more mobile than wood in otherwise similar temperate streams because of the warm and humid conditions that promote decay and the more frequent and flashier floods of the tropics. To test this hypothesis, we monitored all large wood pieces for 2.3 years in 10 50-m-long reaches of old-growth headwater streams in La Selva Biological Station, Costa Rica. Annual wood retention rates for pieces ranged from 0.55 to 0.91 among the sites, and retention rates by volume ranged from 0.67 to 0.99. Assuming steady state wood load, which is reasonable for La Selva, these rates are equivalent to mean residence times of 2.2-10.6 years for pieces, and 3.0-83.2 years for a volume of wood. Calculating mean residence time from the weighted average of retention rates gives an average residence time of 4.9 years for a piece of wood and 6.9 years for a volume of wood. These values are less than those reported for old-growth temperate forests, supporting our hypothesis. Mobility of individual pieces was best predicted by piece length relative to stream width ( lr, higher lr led to lower mobility), channel gradient ( s, higher s led to higher mobility), and piece integration into the channel (unattached pieces were 2.6 times more mobile than attached, ramp, or bridge pieces). Temporal variation in retention rates was well explained by variation in peak flow. All four of these factors have also been observed to influence mobility in the temperate zone. The higher mobility of wood in our study site relative to the temperate rainforest of the Pacific Northwest may be explained by the flashy and frequent floods, the high decay rate, or the branching morphology of the native trees; but differentiating the role of these factors, particularly flow and decay, will be complicated by their covariation across climates.

  2. Effects of Borate Impregnation on the Color and Mechanical Properties of Heat-treated Rubber Wood%硼预处理对橡胶木热改性材颜色和力学性能的影响

    Institute of Scientific and Technical Information of China (English)

    李晓文; 李民; 秦韶山; 李家宁

    2011-01-01

    研究硼琢处理对橡胶木热改性材颜色和力学性能的影响。结果显示,1%浓度硼砂溶液预处理,对热改性材的颜色没有影响,当硼砂浓度增加到4%或8%时,木材材色有偏红的趋势。在185℃的热改性条件下,经硼预处理的热改性材的抗弯强度高于对照,在200℃条件下热改性后则无此规律。分析认为,硼预处理对热改性过程有一定影响,但并不是影响热改性材颜色和力学性能的主要因素。%The color and strength of heat-treated rubber wood which were impregnated by sodium borate were evaluated. Wood treated with 1% sodium borate solution showed no significant difference compared with control samples; when treated with 4% or 8% sodium borate solution, the color of wood turned red slightly. When the temperature of heat treatment was at 185℃, borate impregnation had a positive effect on wood strength, but when the temperature of heat treatment went as high as 200℃, the positive effect could not be observed. Borate impregnation affected the property of heat-treated wood, but it was not one of the fatal factors.

  3. RETENTION AND PENETRATION OF CCA IN WOOD OF FIRST AND SECOND ROTATION OF Eucalyptus urophylla S.T. Blake

    Directory of Open Access Journals (Sweden)

    Mara Lúcia Agostini Valle

    2013-06-01

    Full Text Available http://dx.doi.org/10.5902/198050989292This study aimed to evaluate the retention and penetration of copper chrome arsenate (CCA type C as well as some wood properties of two rotations of two natural hybrid of Eucalyptus urophylla S. T. Blake, aiming their use as treated wood. The study was conducted with material from commercial plantations, with 63 months of age. For the wood characterization, the relationship sapwood-heartwood, the basic density and the size of fibers and vessels were evaluated. For the evaluation of treated wood, the penetration and retention of copper chrome arsenate (CCA type C were determined. Four trees per rotation and genetic material were used, which subsequently were split into three logs, in a total of 12 logs for each treatment. The preservative treatment was performed using the full cell process in autoclave using CCA solution with 2% concentration of active ingredients. The treatment process used was effective under the conditions required by the NBR 9480, with retention values ​​higher than the minimum required by the standard, which is 6.5 kg/m3 of CCA per treated wood, and in addition, provided deep penetration and regular condom in sapwood of all timber treated. There are no restrictions on the use of wood from the first and second rotation for preservative treatment, based on the properties evaluated. There was no correlation between the type C CCA retention and wood properties evaluated.

  4. Effects of Treatment Materials on the Physical Properties of Eucalyptus (Eucalyptus camaldulensis Dehn. Wood

    Directory of Open Access Journals (Sweden)

    Selahattin Bardak

    2011-04-01

    Full Text Available This study was designed to determine effects on retention and shrink levels of Eucalyptus (Eucalyptus camaldulensis Dehn. which treated with some commercial preservative types, borates, polyethylene glycol, and water repellents. In this study, four type impregnation chemicals were chosen: 1. Commercial preservative types, [Ammonium sulphate, Vacsol-WR WR and Immersol-WR (WR], 2. Borates chemicals, [Boric acid, Borax, Boric acid+ Borax] 3. Polyethylene glycol such as Polyethylene glycol (PEG-400 4. Water repellents [Styrene, Methylmetacrylate.]. As a result, retention % and shrink levels of Eucalyptus wood was lower treated with commercial preservative types and borates preservatives compare to other treatment chemicals. However, retention % levels of Eucalyptus wood treated with WR chemicals were highly significant levels. According to their leachability period although PEG 400 showed antishrink effectiveness other treatments didnt showed antishrink efficiency.

  5. Wood

    DEFF Research Database (Denmark)

    Unterrainer, Walter

    2014-01-01

    has shrinked by 30% since the preindustrial times and in countries like China (with a historic tradition for wooden architecture) we could observe enormous desertification. What does this mean for the use of wood in modern architecture ? A critical reflection is needed. In too many cases...

  6. Borat vihastas ka rumeenlasi

    Index Scriptorium Estoniae

    2006-01-01

    Rumeenia mustlasküla Glod elanikud peavad endi solvamiseks viisi, kuidas neid ära kasutati Briti koomiku Sacha Baron Coheni loodud peategelasega USA filmi "Borat - kultuurialased õppetunnid Ameerikast abiks suursuguse Kasahstani riigi ülesehitamisel" võtetel

  7. Effects of Different Wood Preservatives on The Some Physical Properties of Wood Species Used in Furniture and Building Industry

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    Abdi Atılgan

    2012-04-01

    Full Text Available This study aims to determine the combustion, density values of Fagus and Pinus sylvestris’ woods impregranted with Ammonium tetra fluoro borate (1 - 3 % and the mixture of cement and borax (6 % – 9 % according to ASTM-D 1413-76 standards. In the combustion test carried out according to ASTM-D 160-50, the combustion resulted from flame, the self-combustion and the combustion as glowing processes were completed and the amount of lux, combustion duration, decomposition and ash were determined. According to experimental results, it is determined that Fogus’ wood has the highest retention (42,43 kg/m3 in the mixture of cement and borax 9 %, combustion tempature (587 o C in the mixture of cement and borax 6 % , the value of lux (267 lux in the the combustion as glowing and Pinus sylvestris’ wood has the longest combustion duration (29,03 min. Ammonium tetrafluoro borate 1%, the most weight loss (94 %.

  8. Preservative treatment of Eucalyptus camaldulensis Dehnh. juvenile wood by sap displacement method

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    Pablo Marcel de Arruda Torres

    2011-06-01

    Full Text Available The research analyzed the quality of the preservative treatment of Eucalyptus camaldulensis Dehnh juvenile wood and verified the influence of the inversion of the pieces, in preservative solution, in the distribution, penetration and retention of CCB in treated pieces. Trees of Eucalyptus camaldulensis were collected in the rural area of the municipality of Rio Tinto, Paraíba, Brazil, in a stand aged four years. In the stand were randomly chosen five trees, being three of them with the larger diameter. For the wood treatment it was used the sap displacement method by radial transpiration using a 2% solution of ingredients copper chrome borate (CCB and compared the effect of the inversion of pieces on the preservative solution. The distribution, penetration and retention were better in reversed pieces when compared with the ones non-reversed in the preservative solution.

  9. Wood {delta}13C, {delta}18O and radial growth responses of residual red pine to variable retention harvesting.

    Science.gov (United States)

    Powers, Matthew D; Pregitzer, Kurt S; Palik, Brian J; Webster, Christopher R

    2010-03-01

    Variable retention harvests are used to enhance the development of structural complexity in managed forests by retaining living trees and other structural legacies from the pre-harvest ecosystem. While harvesting should increase resource availability to residual trees, greater crown exposure may also increase environmental stress, which makes it difficult to predict growth in different structural environments. We used stable carbon isotope ratios (delta(13)C) of annual rings from red pine trees (Pinus resinosa Ait.) as an index of intrinsic water use efficiency (iWUE), the ratio of photosynthetic carbon assimilation (A) to stomatal conductance (g(s)), to better understand how differences in physiological performance relate to growth responses following harvests that left residuals dispersed, aggregated between small (0.1 ha) gaps or aggregated between large (0.3 ha) gaps. Stable oxygen isotope ratios (delta(18)O) were used as an index of g(s) to investigate the drivers behind changes in iWUE. Retention harvesting did not appear to affect delta(13)C or delta(18)O at the stand scale when compared to unharvested control stands, but there was a significant, negative correlation between residual tree delta(13)C and plot basal area in the second and third years after harvesting that suggests declining iWUE as overstory competition increases. Residual tree delta(18)O was similar across treatments and basal areas. Trees in variable retention harvests showed small but positive increases in radial growth from the pre-treatment to post-treatment measurement periods, while radial growth declined in unharvested control stands. There were no significant differences in radial growth among retention treatments. Our results suggest residual red pine in relatively open environments benefit from greater A but do not show evidence of changes in g(s) that would indicate altered water relations.

  10. Reducing leaching of boron-based wood preservatives - a review of research.

    Science.gov (United States)

    Obanda, Diana N; Shupe, Todd F; Barnes, H Michael

    2008-10-01

    Inorganic borates offer good protection to timber in most non-ground contact applications. The effective use of low solubility borates has not yet been achieved in the treatment of solid lumber. Interest in reducing the leaching of borates stems from their favorable environmental characteristics and broad spectrum efficacy. The key to extending the use of borates to cover the entire spectrum of wood preservation is improving their permanence in wood while retaining efficacy by retaining limited mobility of the borate. We review research over the last two decades in laboratories around the world and classify all strategies employed into fifteen categories. For each strategy, resistance of the treated wood to wood destroying organisms, resistance to leaching, and potential applications are discussed.

  11. "Borat" kogus tubli hulga vaatajaid

    Index Scriptorium Estoniae

    2006-01-01

    Briti koomiku Sacha Baron Coheni loodud peategelasega USA film "Borat - kultuurialased õppetunnid Ameerikast abiks suursuguse Kasahstani riigi ülesehitamisel" kogus Eesti kinolevis avanädalavahetusel 12 487 vaatajat (taasiseseisvumisaja neljas tulemus)

  12. Tere tulemast Eestisse, Borat Sagdijev! / Triin Tael

    Index Scriptorium Estoniae

    Tael, Triin

    2006-01-01

    Briti koomiku Sacha Baron Coheni loodud peategelasega USA film "Borat - kultuurialased õppetunnid Ameerikast abiks suursuguse Kasahstani riigi ülesehitamisel" esilinastub Eesti kinodes. Lisaks "Juut, kes mängib juudivihkajaid", "Borat ei taha kuningannaga seksida", "Vaene solvatud Kasahstan"

  13. Kombinasi Boraks dan Asam Borat sebagai Bahan Penghambat Api dan Antirayap Pada Kayu Meranti Merah

    Directory of Open Access Journals (Sweden)

    Mahdi Santoso

    2015-01-01

    Full Text Available Kayu mempunyai sifat yang mudah terbakar dan sebagian besar mempunyai keawetan alami yang rendah. Perbaikan kualitas kayu dilakukan untuk mengatasi kelemahan tersebut, salah satunya dengan mengimpregnasikan bahan kimia yang bersifat menghambat api dan beracun terhadap organisme perusak kayu. Tujuan penelitian ini adalah melihat kemampuan boraks:asam borat (1:1 untuk meningkatkan ketahanan kayu meranti merah terhadap api dan rayap kayu kering dan mengetahui proses pengawetan yang efektif. Penelitian ini menggunakan kayu meranti merah (Shorea spp berukuran 6 x 15 x 500 cm. Waktu pengawetan adalah 1, 2, dan 3 jam serta konsentrasi bahan pengawet 7% dalam 5 ulangan. Metode pengawetan menggunakan metode sel kosong dengan tekanan 12 kg/cm2 . Pengujian ketahanan terhadap api mengacu pada ASTM E 69-02 prosedur B, pengujian ketahanan terhadap rayap kayu kering mengacu pada metode rayap makan tanpa pilihan. Parameter yang diamati ialah absorpsi, retensi aktual, intensitas bakar, suhu pembakaran maksimal, lama pembaraan, mortalitas rayap kayu kering, pengurangan berat contoh uji, derajat kerusakan dan kondisi fisik sampel setelah uji bakar. Hasil penelitian menunjukkan bahwa kombinasi boraks:asam borat (1:1 memiliki efektivitas yang tinggi untuk meningkatkan ketahanan kayu meranti merah terhadap api dan rayap kayu kering. Proses pengawetan yang paling efektif adalah lama penekanan 2 jam dengan absorpsi 331 kg/m3 ; retensi aktual 28,8 kg/m3 ; intensitas bakar 10,9%; suhu pembakaran maksimal 140ºC; lama pembaraan 1,03 menit; mortalitas rayap kayu kering 100%; pengurangan berat contoh uji 0,002%; serta derajat kerusakan kategori ringan. Katakunci: penghambat api, anti rayap, boraks, Shorea spp, Cryptotermes cynocephalus   Borax and Boric Acid Combination As Fire Retardant and Anti-termite Agents on Red Meranti Wood Abstract Woods have properties which are easy to be ignited by fire and most of them have a low natural durability. Therefore, it is required to

  14. Kes on Borat? / Timo Diener

    Index Scriptorium Estoniae

    Diener, Timo

    2006-01-01

    Eesti kinodesse on jõudnud briti koomiku Sacha Baron Coheni loodud peategelasega USA film "Borat - kultuurialased õppetunnid Ameerikast abiks suursuguse Kasahstani riigi ülesehitamisel" : režissöör Larry Charles. Filmi peaosalisest ja filmi seiklusrikkast võtteperioodist

  15. High-temperature borate crystal chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Bubnova, Rimma S. [Russian Academy of Sciences, St. Petersburg (Russian Federation). Grebenshchikov Institute of Silicate Chemistry; Saint Petersburg State Univ. (Russian Federation). Dept. of Crystallography; Filatov, Stanislav K. [Saint Petersburg State Univ. (Russian Federation). Dept. of Crystallography

    2013-10-01

    The paper presents a brief review of the present state of high-temperature borate crystal chemistry. This review summarizes the results of high- and low-temperature single crystal X-ray diffraction studies for more than 10 borate structures and high-temperature powder Xray diffraction data for about 65 borates. Thermal behavior of their crystal structures, thermal expansion, polymorphic transitions and their relationship to borate glasses are presented. These studies allow to formulate the basic principles of high-temperature borate crystal chemistry and to reveal the regularities of thermal behavior of borates. On heating, the BO{sub 3} and BO{sub 4} polyhedra and rigid groups consisting of these polyhedra, practically maintain their configuration and size, but they are able to rotate like hinges exhibiting highly anisotropic thermal expansion, including linear negative expansion. Based on these results, we generalize the term 'rigid group' and render thermal vibrations as the key ingredient for the self-assembly of borate rigid groups. (orig.)

  16. Impregnation of Natural Rubber into Rubber Wood: A Green Wood Composite

    OpenAIRE

    Wassa Ruayruay; Sureurg Khongtong

    2014-01-01

    A green wood composite material was developed from the two environmentally friendly substrates natural rubber (cis-1,4-polyisoprene) and rubber wood (Hevea brasiliensis). Natural rubber (NR) was introduced into rubber wood by pressurization of NR latex, followed by the removal of the aqueous phase to allow only dry NR to remain inside the wood structure. Scanning electron microscopy images and the weight increase of the dry impregnated samples revealed the retention of dry NR within the rubbe...

  17. Repliik filmi "Borat" kohta / Urve Kirss

    Index Scriptorium Estoniae

    Kirss, Urve

    2007-01-01

    Briti koomiku Sacha Baron Coheni loodud peategelasega USA film "Borat - kultuurialased õppetunnid Ameerikast abiks suursuguse Kasahstani riigi ülesehitamisel" : režissöör Larry Charles. Vaataja mõtteid

  18. Tribological performance of nanometer samarium borate

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Nanometer crystal samarium borate with a particle size of 20~40 nm was prepared using replacing solvent drying technique. The wear resistance and load-carrying capacity of 500SN base oil could be improved and the friction coefficient could be decreased by the addition of nanometer samarium borate. But the dosage of samarium borate nanoparticles had to be controlled at a relatively low level, a higher concentration of nanoparticles was not of beneficial to the tribological performance of the oil. The optimal dosage of nanometer samarium borate is 1.0%. Tribochemical reactions took place in the tribological process, which resulted in the formation of deposition products including diboron trioxide and disamarium trioxide. Fe2B and FeB were also found on the wear scar. The improvement of tribological properties of the oil comes from the formation of deposition layer and permeating layer.

  19. COMBUSTION PROPERTIES OF EUCALYPTUS WOOD

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    Yalçın ÖRS

    1999-03-01

    Full Text Available In this study, the combustion properties of some impregnation materials (abiotic and biotic factors used for eucalyptus wood in interior or exterior environments were investigated. The experimental samples were prepared from Eucalyptus wood based on ASTM-D-1413-76 Tanalith-CBC, boric acid, borax, vacsol-WR, immersol-WR, polyethylen glycole-400 and ammonium sulphate were used as an impregnation material. The results indicated that, vacuum treatment on Eucalyptus gave the lowest retention value of salts. Compounds containing boron+salt increased fire resistance however water repellents decreased the wood flammability.

  20. Bioactive borate glass coatings for titanium alloys.

    Science.gov (United States)

    Peddi, Laxmikanth; Brow, Richard K; Brown, Roger F

    2008-09-01

    Bioactive borate glass coatings have been developed for titanium and titanium alloys. Glasses from the Na(2)O-CaO-B(2)O(3) system, modified by additions of SiO(2), Al(2)O(3), and P(2)O(5), were characterized and compositions with thermal expansion matches to titanium were identified. Infrared and X-ray diffraction analyses indicate that a hydroxyapatite surface layer forms on the borate glasses after exposure to a simulated body fluid for 2 weeks at 37 degrees C; similar layers form on 45S5 Bioglass((R)) exposed to the same conditions. Assays with MC3T3-E1 pre-osteoblastic cells show the borate glasses exhibit in vitro biocompatibility similar to that of the 45S5 Bioglass((R)). An enameling technique was developed to form adherent borate glass coatings on Ti6Al4V alloy, with adhesive strengths of 36 +/- 2 MPa on polished substrates. The results show these new borate glasses to be promising candidates for forming bioactive coatings on titanium substrates.

  1. Borate in mummification salts and bones from Pharaonic Egypt.

    Science.gov (United States)

    Kaup, Yoka; Schmid, Mirjam; Middleton, Andrew; Weser, Ulrich

    2003-03-01

    Mummification processes in Pharaonic Egypt were successful using sodium salts. Quite frequently sodium concentrations in mummified bones ranged from 300 to 4000 micromol/g. In the search for an effective inorganic conservation compound our choice fell on boric acid. The possible presence of borate in mummification salts used in Pharaonic Egypt was of special interest both historically and biochemically. In two salt samples, one from the embalming material of Tutankhamen (18th dynasty, 1336-1327 BC) and the second from Deir el-Bahari (25th dynasty, 700-600 BC) borate was found, amounting to 2.1+/-0.2 and 3.9+/-0.1 micromol/g, respectively. In five of the examined bone fragments from the Junker excavation at Giza (Old Kingdom) similar borate concentrations i.e., 1.2 micromol borate/g bone were seen. It must be emphasized that the usual borate content of contemporary autopsy is far below the detection limit. The elevated borate content in both mummification salt and ancient bone samples support the suggestion that borate-containing salt had been used. There is a striking correlation of both borate concentration and alkaline phosphatase activity. When both sodium salts and borate were essentially absent no activity at all was detectable. With increasing borate concentrations the enzyme activity rises significantly. Attributable to the distinct biochemistry of the tetrahydroxyborate anion it was of interest whether or not borate may stabilize alkaline phosphatase, an important and richly abundant bone enzyme. This enzyme was chosen, as it is known to survive more than 4000 years of mummification. In the presence of borate oligomeric species of this zinc-magnesium-glycoprotein at 400,000 Da became detectable. Attributable to this borate-dependent stabilization of the enzyme molecule a significant temperature resistant increase of the enzymic activity was measured in the presence of up to 2.5 mM borate.

  2. DRAINAGE AND RETENTION ENHANCEMENT OF A WHEAT STRAW PULP CONTAINING FURNISH USING MICROPARTICLE RETENTION AIDS

    Directory of Open Access Journals (Sweden)

    Tom Hultholm

    2011-02-01

    Full Text Available The usage of non-wood pulps in furnishes for the production of various paper grades is a real alternative for the substitution of wood pulp in papermaking. In terms of the papermaking process, the main limiting factor for non-wood pulp utilization is poor dewatering. This problem can be partially solved by means of retention aids, and the modern microparticle-based retention aids are very promising for this application. In this study the main aim was to characterize how the microparticle retention systems affect the retention, dewatering, and formation of a non-wood pulp furnish and how these effects and mechanisms differ when compared to normal wood pulp. The performance of several commercially available retention aids was studied by making dynamic sheet forming tests for reference and an organosolv wheat straw furnish. The emphasis in the experiments was on drainage enhancement. The maximum drainage gain obtained with the bentonite-CPAM retention aid system was about 5%. Despite the improved drainage, dewatering of the reference furnish was better than for the non-wood containing furnish.

  3. Enhancing mechanical properties of ceramic papers loaded with zeolites using borate compounds as binders

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    Juan P. Cecchini

    2013-02-01

    Full Text Available NaY zeolite-containing ceramic papers were prepared by a papermaking technique with a dual polyelectrolyte retention system that implied the use of cationic and anionic polymers. To improve their mechanical properties, we found that some borate compounds could be successfully used as ceramic binders. Three types of sodium and/or calcium borates were tested as binders: colemanite, nobleite, and anhydrous ulexite. The improvement in the mechanical properties depends both on the borate used and on the calcination temperature. By XRD it was determined that the faujasite structure collapsed after calcination at 700°C, which limited the final calcination temperature of zeolitic ceramic papers. Different amounts of NaY zeolite were added to ceramic papers and, as observed by SEM, faujasite particles were well distributed throughout the ceramic paper structure. Ceramic papers containing 1.2 wt.% zeolite after calcination at 650°C resulted in structured catalysts that were easy-to-handle, and which can be adapted to different conformations.

  4. Wooded areas

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report summarizes the management of wooded areas on Neal Smith National Wildlife Refuge (formerly Walnut Creek National Wildlife Refuge) between 1992 and 2009.

  5. Structural relaxation in bismuth and lead borate glasses

    Science.gov (United States)

    Bajaj, Anu; Khanna, Atul

    2012-06-01

    Bismuth and lead borate glasses were prepared by melt quench technique. Effects of heat treatment on the density and thermal properties of bismuth and lead borate glasses was studied by annealing the glasses at 350°C for 500 h. Density of all bismuth borate glasses increases by about 0.5-0.7% with annealing and the effect is more in glasses with higher Bi2O3 concentration. In bismuth borate glasses with 50 and 55 mol % Bi2O3 we found an extraordinary large increase of Tg by 15°C after thermal annealing. All bismuth borate glasses remained completely clear and transparent on annealing. Lead borate glasses become cloudy on thermal annealing indicating occurrence of phase separation in these glasses.

  6. Interfacial reactions between titanium and borate glass

    Energy Technology Data Exchange (ETDEWEB)

    Brow, R.K. [Sandia National Labs., Albuquerque, NM (United States); Saha, S.K.; Goldstein, J.I. [Lehigh Univ., Bethlehem, PA (United States). Dept. of Materials Science

    1992-12-31

    Interfacial reactions between melts of several borate glasses and titanium have been investigated by analytical scanning electron microscopy (SEM) and x-ray photoelectron spectroscopy (XPS). A thin titanium boride interfacial layer is detected by XPS after short (30 minutes) thermal treatments. ASEM analyses after longer thermal treatments (8--120 hours) reveal boron-rich interfacial layers and boride precipitates in the Ti side of the interface.

  7. Effect of Durability Treatment on Ultraviolet Resistance, Strength, and Surface Wettability of Wood Plastic Composite

    Directory of Open Access Journals (Sweden)

    Huiyuan Li

    2014-05-01

    Full Text Available A comparative analysis of photostabilizing effects of hindered amine light stabilizers (HALSs, an ultraviolet absorber (UVA, and zinc borate (ZnB on wood plastic composites (WPCs was made in this study to show the influence of the accelerated weathering on the surface degradation and loss of mechanical properties of treated WPCs. The results showed that the UVA was the most effective in preventing composite from being bleached, especially when the aging time was longer than 1000 hours. With the addition of the ultraviolet stabilizers, the contact angles increased, indicating increased water wettability. The contact angle of UVA-containing samples was greater than that of the control and the other samples treated with HALSs and ZnB. Flexural properties of all materials decreased after being weathered under xenon-arc light. Materials treated with UVA had higher retention rates in flexural strength and modulus. The results show that, among the agents used, UVA was the most effective additive in preventing WPCs from ultraviolet degradation.

  8. The Synthesis and Physical Properties of Magnesium Borate Mineral of Admontite Synthesized from Sodium Borates

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    Azmi Seyhun Kipcak

    2014-01-01

    Full Text Available Magnesium borates are significant compounds due to their advanced mechanical and thermal durability properties. This group of minerals can be used in ceramic industry, in detergent industry, and as neutron shielding material, phosphor of thermoluminescence by dint of their extraordinary specialties. In the present study, the synthesis of magnesium borate via hydrothermal method from sodium borates and physical properties of synthesized magnesium borate minerals were investigated. The characterization of the products was carried out by X-ray diffraction (XRD, Fourier transform infrared (FT-IR and Raman spectroscopies, and differential thermal analysis and thermal gravimetry (DTA/TG. The surface morphology was examined by scanning electron microscopy (SEM. B2O3 content was determined through titration. The electrical resistivity/conductivity properties of products were measured by Picoammeter Voltage Source. UV-vis spectrometer was used to investigate optical absorption characteristics of synthesized minerals in the range 200–1000 nm at room temperature. XRD results identified the synthesized borate minerals as admontite [MgO(B2O33·7(H2O] with code number “01-076-0540” and mcallisterite [Mg2(B6O7(OH62·9(H2O] with code number “01-070-1902.” The FT-IR and Raman spectra of the obtained samples were similar with characteristic magnesium borate bands. The investigation of the SEM images remarked that both nano- and microscale minerals were produced. The reaction yields were between 75.1 and 98.7%.

  9. The Fabrication and Properties Characterization of Wood-Based Flame Retardant Composites

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    Xia He

    2014-01-01

    Full Text Available Wood-based flame retardant composites were fabricated based on vacuum-pressure impregnating method after high intensive microwave pretreatment. The effects of ammonium polyphosphate (APP and modified nano-zinc borate (nZB addition on flame-retardation and smoke-suppression properties of wood were investigated by cone calorimeter method (CONE and thermogravimetric analysis (TGA. The results show that the heat release rate (HRR, peak heat release rate (pk-HRR, and total heat release (THR of APP-treated woods decreased greatly with increasing concentration of APP. However, mean yield of CO (Mean COY of APP-treated wood was much higher (3.5 times than that of untreated wood. Compared with wood treated with APP at a concentration of 15%, the total smoke product (TSP, Mean COY, and pk-HRR decreased by 78.4%, 71.43%, and 31.23%, when wood was treated with APP and nZB (both concentrations were at 15%. APP and nZB have synergistic effects of flame-retardation and smoke-suppression. Nano-zinc borate combined with APP would be used in wood-based composites to efficiently retard flame, reduce fire intensity, and decrease noxious (CO/smoke release.

  10. Weathering Characteristics of Wood Plastic Composites Reinforced with Extracted or Delignified Wood Flour

    Directory of Open Access Journals (Sweden)

    Yao Chen

    2016-07-01

    Full Text Available This study investigated weathering performance of an HDPE wood plastic composite reinforced with extracted or delignified wood flour (WF. The wood flour was pre-extracted with three different solvents, toluene/ethanol (TE, acetone/water (AW, and hot water (HW, or sodium chlorite/acetic acid. The spectral properties of the composites before and after artificial weathering under accelerated conditions were characterized by Fourier transform infrared (FTIR spectroscopy, the surface color parameters were analyzed using colorimetry, and the mechanical properties were determined by a flexural test. Weathering of WPC resulted in a surface lightening and a decrease in wood index (wood/HDPE and flexural strength. WPCs that were reinforced with delignified wood flour showed higher ΔL* and ΔE* values, together with lower MOE and MOR retention ratios upon weathering when compared to those with non-extracted control and extracted WF.

  11. Allyl borates: a novel class of polyhomologation initiators

    KAUST Repository

    Wang, De

    2016-12-24

    Allyl borates, a new class of monofunctional polyhomologation initiators, are reported. These monofunctional initiators are less sensitive and more effective towards polymethylene-based architectures. As an example, the synthesis of α-vinyl-ω-hydroxypolymethylenes is given. By designing/synthesizing different allylic borate initiators, and using 1H and 11B NMR spectroscopy, the initiation mechanism was elucidated.

  12. Structure and Properties of Compressed Borate Glasses

    DEFF Research Database (Denmark)

    Smedskjær, Morten Mattrup; Bauer, U.; Behrens, H.;

    in a series of borate glasses. Upon isostatic compression, NMR experiments show that the fraction of tetrahedral boron increases, leading to an overall decrease of the molar volume of the network. We correlate these structural changes with changes in elastic moduli from Brillouin scattering experiments......While the influence of thermal history on the structure and properties of glasses has been thoroughly studied in the past century, the influence of pressure history has received considerably less attention. In this study, we investigate the pressure-induced changes in structure and properties...

  13. Friction and wear performances of borates and lanthanum chloride in water

    Institute of Scientific and Technical Information of China (English)

    CHEN Boshui; FANG Jianhua; WANG Jiu; LI Jia; LOU Fang

    2008-01-01

    The antiwear and friction-reducing performances of sodium borate, potassium borate and lanthanum chloride in water were evaluated on a four-ball friction tester. The topographies, element distribution and chemical characteristics of the worn surfaces were investigated by scanning electron microscope (SEM), energy dispersion of X-ray (EDX) and X-ray photoelectron spectroscope (XPS). The results indicated that sodium borate, potassium borate and lanthanum chloride increased extreme pressure, antiwear and friction-reducing capacities of water to a certain extent, of which potassium borate was the best candidate. Combination of lanthanum chloride with sodium borate and potassium borate respectively further improved antiwear and friction-reducing capacities. Scratches of worn surfaces lubricated with water containing borates and lanthanum chloride were less severe than those lubricated with water containing borates alone. A tribochemical film mainly composed of oxides of lanthanum, boron and iron reduced friction and wear for water lubricant formulated with both borates and lanthanum chloride.

  14. Devitrification properties of lead borate glasses

    Science.gov (United States)

    Bajaj, Anu; Khanna, Atul; Krishnan, K.; Aggarwal, Suresh K.

    2013-06-01

    Lead borate glasses containing 30 to 60 mol% PbO were prepared by melt quenching technique and devitrified by long duration heat treament in the supercooled region. Glasses crystallized on heating above their glass transition temperature, and the crystalline phases produced on devitrification were characterized by XRD and DSC analyses. Glass with 30 mol% PbO slowly formed a solid solution of Pb6B10O21 and Pb5B8O17 crystalline phases, while glasses with 40 and 50 mol% PbO formed a mixture of Pb6B10O21, Pb5B8O17 and the remanent glassy phase. Glasses with higher PbO concentration of 56 to 60 mol% devitrified completely and produced only Pb5B8O17 crystalline phase. Lead borate glasses with PbO concentration of 40 to 50 mol% showed maximum thermal stability against devitrification, the ease of crystallization of glasses was correlated with the fraction of tetrahedral borons in them.

  15. [Raman and infrared spectrograms of organic borate intercalated hydrotalcite].

    Science.gov (United States)

    Zhang, Jing-Yu; Bai, Zhi-Min; Zhao, Dong

    2013-03-01

    The pattern of X-ray diffraction, the Raman and infrared spectra of organic borate intercalated hydrotalcite were discussed. The well crystallized zinc-aluminum layered double hydroxides (Zn-Al LDHs) intercalated by carbonate ions and borate ions were respectively prepared by co-precipitation method. Patterns of X-ray diffraction showed that the (003) reflection of borate-LDHs was sharp and symmetric and shifted to lower angle than that of carbonate-LDHs. The gallery height of borate-LDHs increased from 0. 28 nm to 0.42 nm after intercalation, indicating that interlayered carbonate ions were substituted by borate anions. The Raman and IR spectra showed that specific bands of carbonate ions in the borate-LDHs disappeared, but with the presence of B3O3(OH)4- X B4O5(OH)4(2-) and B(OH)4- in the interlayer galleries. The hydroxide interlayer anions had a significant influence on the band positions in Raman and infrared spectra of modes related to the hydroxyl group. Our results indicate that single phase and pure borate-pillared LDHs can be obtained using tributyl orthoborate as intercalating agents, and the change in the structure and nature of hydrotalcite can be detected precisely by Raman spectroscopy.

  16. Beneficial effect of propane sultone and tris(trimethylsilyl) borate as electrolyte additives on the cycling stability of the lithium rich nickel manganese cobalt (NMC) oxide

    Science.gov (United States)

    Birrozzi, Agnese; Laszczynski, Nina; Hekmatfar, Maral; von Zamory, Jan; Giffin, Guinevere A.; Passerini, Stefano

    2016-09-01

    This study reports the investigation of several compounds as electrolyte additives for Li[Li0.2Mn0.56 Ni0.16 Co0.08]O2 (a.k.a lithium rich NMC) cathode material. Among the compounds investigated via electrochemical and ex-situ analytical techniques, i.e. XRD, XPS and RAMAN spectroscopy, only 1,3-propane sultone and tris(trimethylsilyl) borate show a beneficial effect on the capacity retention and coulombic efficiency of the layered cathode. The results suggest that the improved capacity retention of the cells containing the two above-mentioned additives mainly originates from their participation in the formation of the cathode passive layer, which prevents the dissolution of the metals from the cathode material. Additionally, the borate additive reduces the lithium consumption upon the passive layer formation thus leaving a higher amount of lithium available in the electrolyte. Graphite/Li[Li0.2Mn0.56 Ni0.16 Co0.08]O2 cells containing the borate additive in the electrolyte showed 85% capacity retention after 485 cycles, confirming the feasibility of its employment for practical applications.

  17. Towards modeling gadolinium-lead-borate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Rada, S., E-mail: Simona.Rada@phys.utcluj.ro [Department of Physics, Technical University of Cluj-Napoca, 400641 Cluj-Napoca (Romania); Ristoiu, T. [Department of Physics, Technical University of Cluj-Napoca, 400641 Cluj-Napoca (Romania); Rada, M. [Department of Mechatronic, Technical University of Cluj-Napoca, 400641 Cluj-Napoca (Romania); Coroiu, I. [Department of Physics, Technical University of Cluj-Napoca, 400641 Cluj-Napoca (Romania); Maties, V. [Department of Mechatronic, Technical University of Cluj-Napoca, 400641 Cluj-Napoca (Romania); Culea, E. [Department of Physics, Technical University of Cluj-Napoca, 400641 Cluj-Napoca (Romania)

    2010-01-15

    Infrared spectra of gadolinium-lead-borate glasses of the xGd{sub 2}O{sub 3}.(100 - x)[3B{sub 2}O{sub 3}.PbO] system, where x = 0, 5, 10, 15, 25, 35 and 50 mol.%, have been recorded to explore the role of content of gadolinium ions behaving as glass modifier. The FTIR spectroscopy data for the xGd{sub 2}O{sub 3}.(1 - x)[3B{sub 2}O{sub 3}.PbO] glasses show the structural role of lead ions as a network-formers and of the gadolinium ions network modifiers. Adding of the rare earth ion up to 35 mol.% into the glass matrix, the IR bands characteristic to the studied glasses become sharper and more pronounced. Structural changes, as recognized by analyzing band shapes of IR spectra, revealed that Gd{sub 2}O{sub 3} causes a change from the continuous borate network to the continuous lead-borate network interconnected through Pb-O-B and B-O-B bridges and the transformation of some tetrahedral [BO{sub 4}] units into trigonal [BO{sub 3}] units. Then, gadolinium ions have affinity towards [BO{sub 3}] structural units which contain non-bridging oxygens necessary for the charge compensation because the more electronegative [BO{sub 3}] structural units were implied in the formation of B-O-Gd bonds and the transformation of glass network into a glass ceramic. We propose a possible structural model of building blocks for the formation of continuous random 3B{sub 2}O{sub 3}.PbO network glass used by density functional theory (DFT) calculations. DFT calculations show that lead atoms occupy three different sites in the proposed model. The first is coordinated with six oxygen atoms forming distorted octahedral geometries. The second lead atom has an octahedral oxygen environment and the five longer Pb-O bonds are considered as participating in the metal coordination scheme. The third lead atom has ionic character. In agreement with the results offered by the experimental FTIR data, the theoretical IR data confirm that our proposed structure is highly possible.

  18. DVD. Borat - ühiskonna sanitar / Tiit Tuumalu

    Index Scriptorium Estoniae

    Tuumalu, Tiit, 1971-

    2007-01-01

    Lühiarvustus DVDl ilmunud filmile "Borat - kultuurialased õppetunnid Ameerikast abiks suursuguse Kasahstani riigi ülesehitamisel" : režissöör Larry Charles, peaosas Sacha Baron Cohen : Ameerika Ühendriigid 2006

  19. Borat tungib psüühesse / Rain Tolk

    Index Scriptorium Estoniae

    Tolk, Rain, 1977-

    2006-01-01

    Briti koomik Sacha Baron Cohen ja tema loodud peategelasega film "Borat - kultuurialased õppetunnid Ameerikast abiks suursuguse Kasahstani riigi ülesehitamisel", režissöör Larry Charles : Ameerika Ühendriigid 2006

  20. The cytotoxicity of NiO nanoparticle with borate capping.

    Science.gov (United States)

    Liu, Zunjing; Wang, Yongjing; Pan, Danmei; Chen, Zhi; Pan, Xiaohong; Wang, Yonghao; Lin, Zhang

    2011-11-01

    The impact of surface capping on cytotoxicity of NiO nanoparticle was investigated with Escherichia coil (E.coli) in this work. The NiO nanoparticle and NiO nanoparticle capped by borate (denoted as NiO-borate) were synthesized by hydrothermal method. The average size of both nanoparticles is about 4.0 nm. The plate experiments demonstrated that NiO-borate nanoparticles show lower cytotoxicity than NiO nanopaticles. Further spectrophotometric analysis revealed that the concentration of both extracellular and intercellular Ni2+ in NiO-borate system were lower than that of uncapped one. Intracellular ICP-AES analysis also showed the concentration of Ni element was higher than Ni2+, suggesting the NiO nanoparticles might penetrate into the cellular interior. Comprehensive AFM, SEM and TEM observation illustrated both NiO-borate and NiO nanoparticles lead to the collapse of cellular body, the convex on the cell wall and the damage of cell wall ultimately. In summary, the surface capping with borate on NiO nanopaticles will suppress the release of the Ni2+ ions and impede the contact between the NiO nanoparticle and cell wall, which ultimately decreased the cytotoxicity of NiO nanoparticles.

  1. ІNVESTIGATION OF PECULIARITIES OF PISTON RINGS LASER BORATING

    Directory of Open Access Journals (Sweden)

    BOLSHAKOV V. I.

    2015-11-01

    Full Text Available Problem formulation. Piston rings are subject to wear while in operation. Insufficient wear resistance of materials limits the growth of machines productivity as well as the terms of their exploitation. The required complex of properties of piston rings made of cast iron cannot be always reached by applying traditional methods of heat treatment or chemical heat treatment processing. Thus, application of traditional borating methods associated with diffusion of boron into the solid phase leads to the formation of the working layer exhibiting high brittleness. Therefore, the problem of increasing the wear resistance of piston rings without embrittlement is challenging. The use oflaser heating during borating provides the formation of a new layer with special properties. However, the optimum properties can be achieved only after determining the relationship between the parameters of running a process and the depth of the borated layer. Goal of research. To determine the influence of laser heating parameters on the depth of the borated layer, as the properties of piston rings depend on the depth of the latter. Conclusions. Increase in the speed of displacing parts during laser heating reduces the depth of the borated layer, and increase of the spot diameter enhances the depth of the layer. The phases and structural components of the borated layer were interpreted by means of X-ray and metallographic methods. The results of investigations can be applied to other machine parts, which are subject to intensive wear.

  2. Borate minerals and origin of the RNA world.

    Science.gov (United States)

    Grew, Edward S; Bada, Jeffrey L; Hazen, Robert M

    2011-08-01

    The RNA World is generally thought to have been an important link between purely prebiotic (>3.7 Ga) chemistry and modern DNA/protein biochemistry. One concern about the RNA World hypothesis is the geochemical stability of ribose, the sugar moiety of RNA. Prebiotic stabilization of ribose by solutions associated with borate minerals, notably colemanite, ulexite, and kernite, has been proposed as one resolution to this difficulty. However, a critical unresolved issue is whether borate minerals existed in sufficient quantities on the primitive Earth, especially in the period when prebiotic synthesis processes leading to RNA took place. Although the oldest reported colemanite and ulexite are 330 Ma, and the oldest reported kernite, 19 Ma, boron isotope data and geologic context are consistent with an evaporitic borate precursor to 2400-2100 Ma borate deposits in the Liaoning and Jilin Provinces, China, as well as to tourmaline-group minerals at 3300-3450 Ma in the Barberton belt, South Africa. The oldest boron minerals for which the age of crystallization could be determined are the metamorphic tourmaline species schorl and dravite in the Isua complex (metamorphism between ca. 3650 and ca. 3600 Ma). Whether borates such as colemanite, ulexite and kernite were present in the Hadean (>4000 Ma) at the critical juncture when prebiotic molecules such as ribose required stabilization depends on whether a granitic continental crust had yet differentiated, because in its absence we see no means for boron to be sufficiently concentrated for borates to be precipitated.

  3. Nuclear chemistry model of borated fuel crud

    Energy Technology Data Exchange (ETDEWEB)

    Sawicki, J.A. [Atomic Energy of Canada Ltd., Chalk River, ON (Canada)

    2002-07-01

    Fuel crud deposits on Callaway Cycle 9 once-burnt high-axial offset anomaly (AOA {approx} -15%) feed assemblies revealed a complex 4-phase matted-layered morphology of a new type that is uncommon in pressurized water reactors [1-3]. The up to 140-{open_square}m-thick crud flakes consisted predominantly of insoluble needle-like particles of Ni-Fe oxy-borate Ni{sub 2}FeBO{sub 5} (bonaccordite) and granular precipitates of m-ZrO{sub 2} (baddeleyite), along with nickel oxide NiO (bunsenite) and minor amount of nickel ferrite NiFe{sub 2}O{sub 4} (trevorite). Furthermore, boron in crud flakes showed that the concentration of {sup 10}B had depleted to 10.2{+-}0.2%, as compared to its 20% natural isotopic abundance and its 17% end-of-cycle abundance in bulk coolant. The form and depth distribution of Ni{sub 2}FeBO{sub 5} and m-ZrO{sub 2} precipitates, as well as substantial {sup 10}B burn-up, point to a strongly alkaline environment at the clad surface of the high-duty fuel rods. This paper extends a nuclear chemistry model of heavily borated fuel crud deposits. The paper shows that the local nuclear heat and lithium buildup from {sup 10}B(n,{open_square}){sup 7}Li reactions may help to create hydrothermal and chemical conditions within the crud layer in favor of Ni{sub 2}FeBO{sub 5} formation and a ZrO{sub 2} dissolution-reprecipitation mechanism. Consistent with the model, the hydrothermal formation of Ni{sub 2}FeBO{sub 5} needles was recently proved to be possible in laboratory tests with aqueous NiO-Fe{sub 2}O{sub 3}-H{sub 3}BO{sub 3}-LiOH slurries, at temperatures only slightly exceeding 400 C. (author)

  4. Interaction of Lamb Waves with Domain Walls in an Iron Borate Plate

    Directory of Open Access Journals (Sweden)

    E.A. Zhukov

    2015-12-01

    Full Text Available This work presents the calculation results of the Lamb wave spectra in a plate of iron borate. Experimental data on how flexural vibrations in a borate plate influence its domain structure are provided.

  5. THz spectra of five borates crystals

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Terahertz spectral responses have been studied for five borate crystals Na5[B2P3O13](NBP),Zn3BPO (ZBP),SrB4O7(SBO),Na3La9O3(BO3)8(NLBO)and PbB4O7(PBO).It is found that the samples had good transmission in 0.25-1.5 THz region.Both SBO and NLBO have an absorption coefficient less than 10cm-1.Among them,SBO has not only the smallest absorption coefficient but also a very flat dispersion in the frequency region under investigation.Distinct resonance absorption peaks are observed for ZBP at v1=1.4 THz,v2=2.0 THz and SBO at v=2.4 THz.In the spectrum of PBO,two 8bnormal dispersions appear in the frequency regions 1.44-1.74 and 2.2-2.5 THz.The absorption coetficients and refraction indices of the five crystals are extracted from the THz time-domain(THz-TDB)spectra in 0.25-2.5 THz region.The properties and origins of the spectral responses are addressed.

  6. The tribological performance and tribochemical analysis of novel borate esters as lubricant additives in rapeseed oil

    NARCIS (Netherlands)

    Yan, J.; Zeng, X.; Heide, van der E.; Ren, T.

    2014-01-01

    Two novel borate esters, tris (4-dodecylphenyl) borate and 2-(2-(4-dodecylphenoxy)-1, 3, 6, 2-dioxazaborocan-6-yl) ethanol were synthesized and applied as anti-wear and extreme pressure additives in rapeseed oil. The borate esters possess high anti-wear and extreme pressure properties. XANES and XPS

  7. 76 FR 74831 - Aging Management of Stainless Steel Structures and Components in Treated Borated Water

    Science.gov (United States)

    2011-12-01

    ... COMMISSION Aging Management of Stainless Steel Structures and Components in Treated Borated Water AGENCY...- ISG-2011-01, ``Aging Management of Stainless Steel Structures and Components in Treated Borated Water... management of stainless steel structures and components exposed to treated borated water. In response to...

  8. 21 CFR 872.3400 - Karaya and sodium borate with or without acacia denture adhesive.

    Science.gov (United States)

    2010-04-01

    ... denture adhesive. 872.3400 Section 872.3400 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF... and sodium borate with or without acacia denture adhesive. (a) Identification. A karaya and sodium borate with or without acacia denture adhesive is a device composed of karaya and sodium borate with...

  9. Barium-borate-flyash glasses: As radiation shielding materials

    Science.gov (United States)

    Singh, Sukhpal; Kumar, Ashok; Singh, Devinder; Thind, Kulwant Singh; Mudahar, Gurmel S.

    2008-01-01

    The attenuation coefficients of barium-borate-flyash glasses have been measured for γ-ray photon energies of 356, 662, 1173 and 1332 keV using narrow beam transmission geometry. The photon beam was highly collimated and overall scatter acceptance angle was less than 3°. Our results have an uncertainty of less than 3%. These coefficients were then used to obtain the values of mean free path (mfp), effective atomic number and electron density. Good agreements have been observed between experimental and theoretical values of these parameters. From the studies of the obtained results it is reported here that from the shielding point of view the barium-borate-flyash glasses are better shields to γ-radiations in comparison to the standard radiation shielding concretes and also to the ordinary barium-borate glasses.

  10. Glass-Forming Ability of Soda Lime Borate Liquids

    DEFF Research Database (Denmark)

    Zheng, Qiuju; Mauro, J.C.; Smedskjær, Morten Mattrup;

    2012-01-01

    We investigate the composition dependence of glass-forming ability (GFA) of a series of iron-containing soda lime borate liquids by substituting Na2O for B2O3. We have characterized GFA by measuring the glass stability against crystallization using a differential scanning calorimeter (DSC......). The results show that the GFA decreases when substituting Na2O for B2O3. Moreover, we find that there is no direct link between the kinetic fragility and GFA for the soda lime borate series studied herein. We have also discovered and clarified a striking thermal history dependence of the glass stability...

  11. Optical properties of neodymium doped lanthanum scandium borate

    Energy Technology Data Exchange (ETDEWEB)

    Jang, Won Kweon [Hanseo University, Seosan (Korea, Republic of); Kim, Tae Hoon; Yu, Young Moon [Korea Photonics Technology Institute, Kwangju (Korea, Republic of)

    2001-11-15

    Optical characteristics of neodymium doped lanthanium scandium borate, newly developed crystal, was investigated. Technical description of crystal growth and its dependence on optical property were investigated with comparison to other laser crystals. Its potential as commercial laser crystal for microchip laser fabrication was observed with fundamental lasing experiments. It was possible for lanthanium scandium borate to be highly doped with neodymium ion without crystal defect, and it is an advantage for microchip laser host material. The laser operation was investigated in the fundamental with microchip system.

  12. Mineral preservatives in the wood of Stradivari and Guarneri.

    Science.gov (United States)

    Nagyvary, Joseph; Guillemette, Renald N; Spiegelman, Clifford H

    2009-01-01

    Following the futile efforts of generations to reach the high standard of excellence achieved by the luthiers in Cremona, Italy, by variations of design and plate tuning, current interest is being focused on differences in material properties. The long-standing question whether the wood of Stradivari and Guarneri were treated with wood preservative materials could be answered only by the examination of wood specimens from the precious antique instruments. In a recent communication (Nature, 2006), we reported about the degradation of the wood polymers in instruments of Stradivari and Guarneri, which could be explained only by chemical manipulations, possibly by preservatives. The aim of the current work was to identify the minerals from the small samples of the maple wood which were available to us from the antique instruments. The ashes of wood from one violin and one cello by Stradivari, two violins by Guarneri, one viola by H. Jay, one violin by Gand-Bernardel were analyzed and compared with a variety of commercial tone woods. The methods of analysis were the following: back-scattered electron imaging, X-ray fluorescence maps for individual elements, wave-length dispersive spectroscopy, energy dispersive X-ray spectroscopy and quantitative microprobe analysis. All four Cremonese instruments showed the unmistakable signs of chemical treatments in the form of chemicals which are not present in natural woods, such as BaSO4, CaF2, borate, and ZrSiO4. In addition to these, there were also changes in the common wood minerals. Statistical evaluation of 12 minerals by discriminant analysis revealed: a. a difference among all four Cremona instruments, b. the difference of the Cremonese instruments from the French and English antiques, and c. only the Cremonese instruments differed from all commercial woods. These findings may provide the answer why all attempts to recreate the Stradivarius from natural wood have failed. There are many obvious implications with regard to

  13. Mineral preservatives in the wood of Stradivari and Guarneri.

    Directory of Open Access Journals (Sweden)

    Joseph Nagyvary

    Full Text Available Following the futile efforts of generations to reach the high standard of excellence achieved by the luthiers in Cremona, Italy, by variations of design and plate tuning, current interest is being focused on differences in material properties. The long-standing question whether the wood of Stradivari and Guarneri were treated with wood preservative materials could be answered only by the examination of wood specimens from the precious antique instruments. In a recent communication (Nature, 2006, we reported about the degradation of the wood polymers in instruments of Stradivari and Guarneri, which could be explained only by chemical manipulations, possibly by preservatives. The aim of the current work was to identify the minerals from the small samples of the maple wood which were available to us from the antique instruments. The ashes of wood from one violin and one cello by Stradivari, two violins by Guarneri, one viola by H. Jay, one violin by Gand-Bernardel were analyzed and compared with a variety of commercial tone woods. The methods of analysis were the following: back-scattered electron imaging, X-ray fluorescence maps for individual elements, wave-length dispersive spectroscopy, energy dispersive X-ray spectroscopy and quantitative microprobe analysis. All four Cremonese instruments showed the unmistakable signs of chemical treatments in the form of chemicals which are not present in natural woods, such as BaSO4, CaF2, borate, and ZrSiO4. In addition to these, there were also changes in the common wood minerals. Statistical evaluation of 12 minerals by discriminant analysis revealed: a. a difference among all four Cremona instruments, b. the difference of the Cremonese instruments from the French and English antiques, and c. only the Cremonese instruments differed from all commercial woods. These findings may provide the answer why all attempts to recreate the Stradivarius from natural wood have failed. There are many obvious

  14. Mechanics of Wood Machining

    CERN Document Server

    Csanády, Etele

    2013-01-01

    Wood is one of the most valuable materials for mankind, and since our earliest days wood materials have been widely used. Today we have modern woodworking machine and tools; however, the raw wood materials available are continuously declining. Therefore we are forced to use this precious material more economically, reducing waste wherever possible. This new textbook on the “Mechanics of Wood Machining” combines the quantitative, mathematical analysis of the mechanisms of wood processing with practical recommendations and solutions. Bringing together materials from many sources, the book contains new theoretical and experimental approaches and offers a clear and systematic overview of the theory of wood cutting, thermal loading in wood-cutting tools, dynamic behaviour of tool and work piece, optimum choice of operational parameters and energy consumption, the wear process of the tools, and the general regularities of wood surface roughness. Diagrams are provided for the quick estimation of various process ...

  15. Effect of Magnesium Borates on the Fire-Retarding Properties of Zinc Borates

    Directory of Open Access Journals (Sweden)

    Azmi Seyhun Kipcak

    2014-01-01

    Full Text Available Magnesium borate (MB is a technical ceramic exhibiting high heat resistance, corrosion resistance, great mechanical strength, great insulation properties, lightweightness, high strength, and a high coefficient of elasticity. Zinc borate (ZB can be used as a multifunctional synergistic additive in addition to flame retardant additives in polymers. In this study, the raw materials of zinc oxide (ZnO, magnesium oxide (MgO, and boric acid (H3BO3 were used in the mole ratio of 1 : 1 : 9, which was obtained from preexperiments. Using the starting materials, hydrothermal synthesis was applied, and characterisation of the products was performed using X-Ray diffraction (XRD and Fourier transform infrared (FT-IR and Raman spectroscopies. The forms of Zn3B6O12·3.5H2O, MgO(B2O33·7(H2O, and Mg2(B6O7(OH62·9(H2O were synthesised successfully. Moreover, the surface morphology was investigated using scanning electron microscopy (SEM, and the B2O3 content was determined. In addition, the reaction yields were calculated. The results of the B2O3 content analysis were in compliance with the literature values. Examination of the SEM images indicated that the obtained nanoscale minerals had a reaction efficiency ranging between 63–74% for MB and 87–98% for ZB. Finally, the fire-retarding properties of the synthesised pure MBs, pure ZBs, and mixtures of MB and ZB were determined using differential thermal analysis and thermal gravimetry (DTA-TG and differential scanning calorimetry (DSC.

  16. Leaching and retention of nutrients and trace elements in peat nineteen years after wood ash application and afforestation of a terminated peat cutover area; Utlakning och retention av naeringsaemnen och spaaraemnen i torv nitton aar efter vedasktillfoersel och beskogning paa en avslutad torvtaekt

    Energy Technology Data Exchange (ETDEWEB)

    Nilsson, Torbjoern; Lundin, Lars (Dept. of Forest Soils, Swedish Univ. of Agricultural Sciences, P.O. Box 7001, SE-750 07 Uppsala (Sweden))

    2008-04-15

    Ash application on peatlands for improved biomass production attracts great interest. On drained peatlands in forestry use, application of wood ash would increase the forest production. Before such activities starts on a large-scale, the existing knowledge in this field should be compiled, with the aim to illustrate positive and negative effects of such a measure and to suggest recommendations for wood ash application to drained and afforested peatlands. The aim of this project was to investigate how much of different nutrients and trace elements that was still left in the peat, 19 years after application of 23 tonnes of wood fly ash, 0.6 tonnes of raw phosphate and 0.25 tonnes of superphosphate per hectare to 14 hectares of a terminated peat cutover area. This area was located on a mire, Flakmossen, in west-central Sweden. As it was nearly 40 years since peat harvesting had terminated on this mire, the area was drained before the application of wood ash and phosphorus fertilizer. A tractor-driven cultivator mixed the applied fertilizers with the upper 30-40 cm of the remaining peat and afterwards different tree species were planted in the cultivated peat. Peat sampling, down to 80 cm depth, was carried out before soil treatment, one year after, three years after and 19 years after the soil treatment. Analyses of these peat samples showed that: - After the soil treatments an initial increase of pH in the upper peat layers (0-40 cm depth) was observed, but 19 years after the soil treatments pH had decreased to levels that were lower than before the treatments. This decrease in pH was probably due to an oxidation of sulphur compounds in the peat, which was a result of the drainage. This acidification of the peat could not be buffered by the large dose of applied wood ash. However, it should be observed that the main part of the peat in this field study consists of reed peat, that has a considerable higher sulphur content than other peat types. - Nineteen years after

  17. Fire retardants for wood

    Directory of Open Access Journals (Sweden)

    Vlatka Jirouš-Rajković

    2009-06-01

    Full Text Available Along with many advantages, wood as traditional building material also has some disadvantages. One of them is the flammability. The most usual way to improve the fire performance of wood is by treating it with fire retardants that can be applied to wood composite products during manufacture, pressure impregnated into solid wood or wood products or added as a paint or surface coating. Fire retardants are formulated to control ignition, flame spread on the wood surface and to reduce the amount of heat released from wood. Fire retardants cannot make wood non combustible. According to the European reaction-to-fire “Euroclasses”classification system for construction products, wood treated with fire retardant can meet the requirements of Euroclass B, whereas ordinary wood products typically fall into class D. This article attempts to bring together information related to the burning of wood, fire performance of wood, types of fire retardants and mechanism of fire retardancy. Fire retardant coatings and chemical impregnation by pressure-treating are described separately.

  18. Request for wood samples

    NARCIS (Netherlands)

    NN,

    1977-01-01

    In recent years the wood collection at the Rijksherbarium was greatly expanded following a renewed interest in wood anatomy as an aid for solving classification problems. Staff members of the Rijksherbarium added to the collection by taking interesting wood samples with them from their expeditions (

  19. Lignification and tension wood.

    Science.gov (United States)

    Pilate, Gilles; Chabbert, Brigitte; Cathala, Bernard; Yoshinaga, Arata; Leplé, Jean-Charles; Laurans, Françoise; Lapierre, Catherine; Ruel, Katia

    2004-01-01

    Hardwood trees are able to reorient their axes owing to tension wood differentiation. Tension wood is characterised by important ultrastructural modifications, such as the occurrence in a number of species, of an extra secondary wall layer, named gelatinous layer or G-layer, mainly constituted of cellulose microfibrils oriented nearly parallel to the fibre axis. This G-layer appears directly involved in the definition of tension wood mechanical properties. This review gathers the data available in the literature about lignification during tension wood formation. Potential roles for lignin in tension wood formation are inferred from biochemical, anatomical and mechanical studies, from the hypotheses proposed to describe tension wood function and from data coming from new research areas such as functional genomics.

  20. Complex geometries in wood

    DEFF Research Database (Denmark)

    Tamke, Martin; Ramsgaard Thomsen, Mette; Riiber Nielsen, Jacob

    2009-01-01

    The versatility of wood constructions and traditional wood joints for the production of non standard elements was in focus of a design based research. Herein we established a seamless process from digital design to fabrication. A first research phase centered on the development of a robust parame...... parametric model and a generic design language a later explored the possibilities to construct complex shaped geometries with self registering joints on modern wood crafting machines. The research was carried out as collaboration with industrial partners....

  1. Moisture Transport in Wood

    DEFF Research Database (Denmark)

    Astrup, T.; Hansen, K. K.; Hoffmeyer, P.;

    2005-01-01

    Modelling of moisture transport in wood is of great importance as most mechanical and physical properties of wood depend on moisture content. Moisture transport in porous materials is often described by Ficks second law, but several observations indicate that this does not apply very well to wood....... Recently at the Technical University of Denmark, Department of Civil Engineering, a new model for moisture transport in wood has been developed. The model divides the transport into two phases, namely water vapour in the cell lumens and bound water in the cell walls....

  2. Visible luminescence of dysprosium ions in oxyhalide lead borate glasses

    Science.gov (United States)

    Pisarska, Joanna; Żur, Lidia; Pisarski, Wojciech A.

    2011-08-01

    Visible luminescence of Dy 3+ ions in oxyhalide lead borate glasses was examined. Luminescence spectra show two intense bands at 480 nm and 573 nm due to 4F 9/2 → 6H 15/2 (blue) and 4F 9/2 → 6H 13/2 (yellow) transitions of Dy 3+. Luminescence decays from 4F 9/2 state and yellow-to-blue luminescence intensity ratios (Y/B) were analysed with PbX 2 (X = F, Cl) content. An introduction of PbX 2 to the borate glass results in the increasing of 4F 9/2 lifetime and the decreasing of yellow-to-blue luminescence intensity ratio, which is due to reduction of covalency between Dy 3+ and O 2-/X - ions.

  3. FTIR of binary lead borate glass: Structural investigation

    Science.gov (United States)

    Othman, H. A.; Elkholy, H. S.; Hager, I. Z.

    2016-02-01

    The glass samples were prepared according to the following formula: (100-x) B2O3 - x PbO, where x = 20-80 mol% by melt quenching method. The density of the prepared samples was measured and molar volume was calculated. IR spectra were measured for the prepared samples to investigate the glass structure. The IR spectra were deconvoluted using curves of Gaussian shape at approximately the same frequencies. The deconvoluted data were used to study the effect of PbO content on all the structural borate groups. Some structural parameters such as density, packing density, bond length and bond force constant were theoretically calculated and were compared to the obtained experimental results. Deviation between the experimental and theoretically calculated parameters reflects the dual role of PbO content on the network of borate glass.

  4. Infrared spectra of zinc doped lead borate glasses

    Indian Academy of Sciences (India)

    S G Motke; S P Yawale; S S Yawale

    2002-02-01

    The infrared spectra of zinc-doped lead borate glasses (10–30 mol% ZnO) were measured over a continuous spectral range (400–4000 cm–1) in an attempt to study their structure systematically. No boroxol ring formation was observed in the structure of these glasses. The formation of Zn in tetrahedral coordination was not observed. The conversion of three-fold to four-fold coordinated boron took place.

  5. EPR and NMR studies of amorphous aluminum borates

    NARCIS (Netherlands)

    Simon, S.; Pol, A. van der; Reijerse, E.J.; Kentgens, A.P.M.; Moorsel, G.J.M.P. van; Boer, E. de

    1994-01-01

    Amorphous aluminium borates, Al2(1–x)B2xO3 with O [less-than-or-eq]x[less-than-or-eq] 0.5, prepared from mixtures of aluminium nitrate, boric acid and glycerol, have been studied by EPR and 27Al MASNMR as a function of composition and heat-treatment temperature (Tt[less-than-or-eq] 860 °C). EPR stud

  6. DID WE IGNORE THE SOCIAL COMMENTARY? RESPONDING TO BORAT ON YOUTUBE

    Directory of Open Access Journals (Sweden)

    Mārtiņš Kaprāns

    2011-11-01

    Full Text Available Ever since the fictitious Kazakh journalist Borat Sagdiyev became an icon of contemporary popular culture, many questions have arisen about the reception of Borat by the general public. Namely, how have common people created a shared representation of Borat? And how is this complicated character and comedic manner undertaken by Sacha Baron Cohen being deciphered? These questions are crucial for understanding the challenges and constraints of social satire that exploits ethnically and stylistically sophisticated identity. To address these questions, which surely could be asked about other international media products as well, this article deals with the reception of Borat the character on YouTube. In particular, the viewers' reaction to the YouTube video titled "The Best of Borat" is analysed. This video has been viewed more than seven million times and commented on more than seven thousand times. The conceptual framework of this analysis is derived from the theory of social representations postulated by Serge Moscovici. In line with this theory two main dimensions - anchoring and objectification - are explored in order to understand how shared or divergent knowledge of Borat is created. Thus the basic socio-cognitive processes behind Borat are revealed. The results suggest that anchoring of Borat is embedded in national identification discourse, whereas objectification differentiates people according to their sense of humour. Likewise, some implications of Borat's reception for participatory culture and civic engagement are outlined.

  7. Elastic Behavior of Borate Glasses Containing Lead and Bismuth Oxides

    Directory of Open Access Journals (Sweden)

    Mehrdad Khanisanij

    2014-01-01

    Full Text Available PbO and Bi2O3 binary borate glasses with different compositions, (MOX(B2O31−X (M = Pb, Bi, have been characterized and ultrasonic velocity as well as density is taken into account. In addition, the results have been compared with those of Ag, K, and Li oxide borate glasses from others. The ultrasonic velocities (both longitudinal and transverse and density for (PbOX(B2O31−X and (Bi2O3X(B2O31−X have been measured accurately and elastic moduli as well as hardness and Poisson’s ratio was determined. It has been demonstrated that density and ultrasonic velocities are enhanced by increasing PbO and Bi2O3 molar fraction with different values for each borate glass composition. However, the enhancement of ultrasonic velocities did not carry on continuously and after reaching a maximum point, they fell down dramatically. Both PbO and Bi2O3 showed almost similar glass improvement in case of density, ultrasonic velocity, and elastic moduli.

  8. Boron impregnation treatment of Eucalyptus grandis wood.

    Science.gov (United States)

    Dhamodaran, T K; Gnanaharan, R

    2007-08-01

    Eucalyptus grandis is suitable for small timber purposes, but its wood is reported to be non-durable and difficult to treat. Boron compounds being diffusible, and the vacuum-pressure impregnation (VPI) method being more suitable for industrial-scale treatment, the possibility of boron impregnation of partially dry to green timber was investigated using a 6% boric acid equivalent (BAE) solution of boric acid and borax in the ratio 1:1.5 under different treatment schedules. It was found that E. grandis wood, even in green condition, could be pressure treated to desired chemical dry salt retention (DSR) and penetration levels using 6% BAE solution. Up to a thickness of 50mm, in order to achieve a DSR of 5 kg/m(3) boron compounds, the desired DSR level as per the Indian Standard for perishable timbers for indoor use, it was found that neither the moisture content of wood nor the treatment schedule posed any problem as far as the treatability of E. grandis wood was concerned.

  9. Mineralization of fossil wood

    NARCIS (Netherlands)

    Buurman, P.

    1972-01-01

    Several pieces of fossil wood have been analyzed with X-ray diffraction and were grouped on the basis of mineralogical composition. Various mineralizations were studied in thin sections and by means of the scanning electron microscope. Wood-opals appear to show a structure preservation that points t

  10. Fuel nozzle tube retention

    Energy Technology Data Exchange (ETDEWEB)

    Cihlar, David William; Melton, Patrick Benedict

    2017-02-28

    A system for retaining a fuel nozzle premix tube includes a retention plate and a premix tube which extends downstream from an outlet of a premix passage defined along an aft side of a fuel plenum body. The premix tube includes an inlet end and a spring support feature which is disposed proximate to the inlet end. The premix tube extends through the retention plate. The spring retention feature is disposed between an aft side of the fuel plenum and the retention plate. The system further includes a spring which extends between the spring retention feature and the retention plate.

  11. Factors influencing wood mobilization 1 in Minnesota streams

    Science.gov (United States)

    Merten, Eric; Finlay, Jacques; Johnson, Lucinda; Newman, Raymond; Stefan, Heinz; Vondracek, Bruce C.

    2010-01-01

    [1] Natural pieces of wood provide a variety of ecosystem functions in streams including habitat, organic matter retention, increased hyporheic exchange and transient storage, and enhanced hydraulic and geomorphic heterogeneity. Wood mobilization is a critical process in determining the residence time of wood. We documented the characteristics and locations of 865 natural wood pieces (>0.05 m in diameter for a portion >1 m in length) in nine streams along the north shore of Lake Superior in Minnesota. We determined the locations of the pieces again after an overbank stormflow event to determine the factors that influenced mobilization of stationary wood pieces in natural streams. Seven of 11 potential predictor variables were identified with multiple logistic regression as significant to mobilization: burial, effective depth, ratio of piece length to effective stream width (length ratio), bracing, rootwad presence, downstream force ratio, and draft ratio. The final model (Pmobilization under natural conditions is a complex function of both mechanical factors (burial, length ratio, bracing, rootwad presence, draft ratio) and hydraulic factors (effective depth, downstream force ratio). If stable pieces are a goal for stream management then features such as partial burial, low effective depth, high length relative to channel width, bracing against other objects (e.g., stream banks, trees, rocks, or larger wood pieces), and rootwads are desirable. Using the model equation from this study, stewards of natural resources can better manage in-stream wood for the benefit of stream ecosystems.

  12. Hydrolytic stability and tribological properties of N-containing heterocyclic borate esters as lubricant additives in rapeseed oil

    NARCIS (Netherlands)

    Li, J.; Li, Zhipeng; Ren, Tianhui; Zeng, Xiangqiong; Heide, van der Emeil

    2014-01-01

    Borate ester compounds are emerging as promising materials for lubricating systems. The main drawback of borate esters however, is the susceptiblity to hydrolysis. In this work, two kinds of N-containing heterocyclic borate esters were synthesized. Their hydrolytic stability and tribological propert

  13. Cord Wood Testing in a Non-Catalytic Wood Stove

    Energy Technology Data Exchange (ETDEWEB)

    Butcher, T. [Brookhaven National Lab. (BNL), Upton, NY (United States); Trojanowski, R. [Brookhaven National Lab. (BNL), Upton, NY (United States); Wei, G. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2014-06-30

    EPA Method 28 and the current wood stove regulations have been in-place since 1988. Recently, EPA proposed an update to the existing NSPS for wood stove regulations which includes a plan to transition from the current crib wood fuel to cord wood fuel for certification testing. Cord wood is seen as generally more representative of field conditions while the crib wood is seen as more repeatable. In any change of certification test fuel, there are questions about the impact on measured results and the correlation between tests with the two different fuels. The purpose of the work reported here is to provide data on the performance of a noncatalytic stove with cord wood. The stove selected has previously been certified with crib wood which provides a basis for comparison with cord wood. Overall, particulate emissions were found to be considerably higher with cord wood.

  14. 76 FR 69292 - Aging Management of Stainless Steel Structures and Components in Treated Borated Water

    Science.gov (United States)

    2011-11-08

    ... COMMISSION Aging Management of Stainless Steel Structures and Components in Treated Borated Water AGENCY... Staff Guidance (LR-ISG), LR- ISG-2011-01, ``Aging Management of Stainless Steel Structures and Components in Treated Borated Water.'' This LR-ISG revises the guidance in the Standard Review Plan...

  15. 77 FR 27815 - Aging Management of Stainless Steel Structures and Components in Treated Borated Water

    Science.gov (United States)

    2012-05-11

    ... COMMISSION Aging Management of Stainless Steel Structures and Components in Treated Borated Water AGENCY..., ``Aging Management of Stainless Steel Structures and Components in Treated Borated Water.'' This LR-ISG... Power Plants (SRP-LR) and Generic Aging Lessons Learned (GALL) Report for the aging management...

  16. Bioplastic production using wood mill effluents as feedstock.

    Science.gov (United States)

    Ben, M; Mato, T; Lopez, A; Vila, M; Kennes, C; Veiga, M C

    2011-01-01

    Fibreboard production is one of the most important industrial activities in Galicia (Spain). Great amounts of wastewater are generated, with properties depending on the type of wood, treatment process, final product and water reusing, among others. These effluents are characterized by a high chemical oxygen demand, low pH and nutrients limitation. Although anaerobic digestion is one of the most suitable processes for the treatment, lately bioplastics production (mainly polyhydroxyalkanoates) from wastewaters with mixed cultures is being evaluated. Substrate requirements for these processes consist of high organic matter content and low nutrient concentration. Therefore, wood mill effluents could be a suitable feedstock. In this work, the possibility of producing bioplastics from to wood mill effluents is evaluated. First, wood mill effluent was converted to volatile fatty acids in an acidogenic reactor operated at two different hydraulic retention times of 1 and 1.5 d. The acidification percentage obtained was 37% and 42%, respectively. Then, aerobic batch assays were performed using fermented wood mill effluents obtained at different hydraulic retention times. Assays were developed using different cultures as inoculums. The maximum storage yield of 0.57 Cmmol/Cmmol was obtained when when the culture was enriched on a synthetic media.

  17. Synthesis and characterization of cadmium doped lead–borate glasses

    Indian Academy of Sciences (India)

    A A Alemi; H Sedghi; A R Mirmohseni; V Golsanamlu

    2006-02-01

    Cadmium doped lead–borate glasses were prepared from the melts in appropriate proportions of PbO2, H3BO3 and (15–40 mol%) CdO mixture in the temperature range 700–950°C. The infrared spectra of the glasses in the range 400–4000 cm-1 show their structures. No boroxol ring formation was observed in the structure of these glasses. Furthermore, doped cadmium atoms were not seen in tetrahedral coordination. But the conversion of three-fold to four-fold coordination of boron atoms in the structure of glasses was observed.

  18. Optical properties of lead borate glasses containing Dy3+ ions

    Science.gov (United States)

    Pisarska, Joanna

    2009-07-01

    Optical properties of lead borate glasses containing Dy3+ ions were examined using absorption and luminescence measurements and theoretical calculations based on the Judd-Ofelt framework and the Inokuti-Hirayama model. The luminescence spectra show two characteristic bands at 480 and 573 nm, which are due to 4F9/2-6H15/2 (blue) and 4F9/2-6H13/2 (yellow) transitions of trivalent Dy3+ ions. The yellow/blue luminescence and its decay were analyzed as a function of activator concentration.

  19. Luminescence behavior of Dy 3+ ions in lead borate glasses

    Science.gov (United States)

    Pisarska, Joanna

    2009-10-01

    Dy-doped lead borate glasses were studied. The luminescence spectra showed two characteristic bands at 480 and 573 nm due to 4F 9/2- 6H 15/2 (blue) and 4F 9/2- 6H 13/2 (yellow) transitions of Dy 3+. The yellow/blue luminescence of trivalent dysprosium was analyzed as a function of the B 2O 3/PbO ratios, the activator (Dy 3+) and the PbX 2 (X = F, Cl, Br) content.

  20. General and Localized Corrosion of Borated Stainless Steels

    Energy Technology Data Exchange (ETDEWEB)

    T.E. Lister; Ronald E. Mizia; A.W. Erickson; T.L. Trowbridge; B. S. Matteson

    2008-03-01

    The Transportation, Aging and Disposal (TAD) canister-based system is being proposed to transport and store spent nuclear fuel at the Monitored Geologic Repository (MGR) located at Yucca Mountain, Nevada. The preliminary design of this system identifies borated stainless steel as the neutron absorber material that will be used to fabricate fuel basket inserts for nuclear criticality control. This paper discusses corrosion test results for verifying the performance of this material manufactured to the requirements of ASTM A887, Grade A, under the expected repository conditions.

  1. The Kerr nonlinearity of the beta-barium borate crystal

    DEFF Research Database (Denmark)

    Bache, Morten; Guo, Hairun; Zhou, Binbin;

    2013-01-01

    A popular crystal for ultrafast cascading experiments is beta-barium-borate (β-BaB2O4, BBO). It has a decent quadratic nonlinear coefficient, and because the crystal is anisotropie it can be birefringence phase-matched for type I (oo → e) second-harmonic generation (SHG). For femtosecond...... experiments BBO is popular because of low dispersion and a high damage threshold. The main attractive property of ultrafast cascading is that the induced cascading nonlinearity nI 2, casc can be negative, i.e. generate a self-defocusing Kerr-like nonlinearity. However, the material Kerr nonlinearity nI 2...

  2. Nuclear quadrupole resonance of boron in borate glasses

    Science.gov (United States)

    Gravina, Samuel J.; Bray, Phillip J.

    A continuous wave nuclear quadrupole resonance spectrometer that has a high sensitivity even at low frequencies has been built. Boron and aluminum NQR has been detected in the region 200 kHz to 1.4 MHz. For the first time, boron NQR has been detected in a glass. The NQR spectrum of pure B 20 3 glass is consistent with 85 ± 2% of the boron atoms belonging to boroxol rings. In sodium borate glasses, the number of borons in boroxol rings decreases with increasing sodium content, until when sodium oxide comprises 20 mol% of the glass less than 2% of the borons are in boroxol rings.

  3. A Potential Criterion to Evaluate Copper Adsorption in Wood Cell Wall

    Institute of Scientific and Technical Information of China (English)

    Jinzhen Cao; Donatien P. Kamdem

    2003-01-01

    A geometrical definition, fractal dimension, was introduced in this study to evaluate copper adsorption in wood treated with copper-containing preservatives. It is based on the assumption that some copper would compete the hydroxyl groups in wood cell wall with water molecules, and therefore influence the fractal dimension of internal wood surfaces revealed by the moisture adsorption in wood. Southern yellow pine (Pinus spp.) specimens were treated with different concentrations of copper ethanolamine (Cu-EA) solution to obtain different copper retention levels. Then the adsorption isotherms of untreated and Cu-EA treated specimens were determined at 4, 15, 30, and 40 ℃ to provide the source data for fractal dimension calculation. The results showed that, at all temperatures, the fractal dimension of the internal wood surfaces had a decreasing trend with increasing copper retention. That is, the internal spaces in wood become "thinner" due to the copper adsorption on some hydroxyl groups in wood cell wall. The correlation between the fractal dimension and adsorbed copper ions makes it possible to evaluate the copper adsorption in wood cell wall.

  4. Evaluation of aluminum phosphide against wood-destroying insects.

    Science.gov (United States)

    Pant, Himani; Tripathi, Sadhna

    2012-02-01

    Aluminum phosphide, a well-known stored grain fumigant, available in solid formulation, has shown promise as wood fumigant. This chemical decomposes to phosphine when exposed to moisture. The feasibility of fumigant treatment to extend the service life of wood was evaluated in a small block test of two wood species. Hard wood (Mangifera indica L.) and conifer blocks (Pinus roxburghii Sargent) were fumigated with different concentrations (0.05, 0.1, 0.2, 0.4, 0.8, and 1.6%) of aluminum phosphide. Fumigated blocks were exposed to Lyctus africanus Lesne (Coleoptera; Lyctidae) larvae. Results revealed that aluminum phosphide showed complete mortality of Lyctus larvae at 0.2% concentration, that is, 0.93 g/m3 retention level. Mean mortality of 74% of Lyctus larvae was observed in soft wood blocks fumigated with lowest concentration, that is, 0.05% of aluminum phosphide, whereas in hard wood blocks > 85% mortality was observed at this concentration.

  5. Wood for the trees

    Directory of Open Access Journals (Sweden)

    Rob Garbutt

    2013-10-01

    Full Text Available Our paper focuses on the materiality, cultural history and cultural relations of selected artworks in the exhibition Wood for the trees (Lismore Regional Gallery, New South Wales, Australia, 10 June – 17 July 2011. The title of the exhibition, intentionally misreading the aphorism “Can’t see the wood for the trees”, by reading the wood for the resource rather than the collective wood[s], implies conservation, preservation, and the need for sustaining the originating resource. These ideas have particular resonance on the NSW far north coast, a region once rich in rainforest. While the Indigenous population had sustainable practices of forest and land management, the colonists deployed felling and harvesting in order to convert the value of the local, abundant rainforest trees into high-value timber. By the late twentieth century, however, a new wave of settlers launched a protest movements against the proposed logging of remnant rainforest at Terania Creek and elsewhere in the region. Wood for the trees, curated by Gallery Director Brett Adlington, plays on this dynamic relationship between wood, trees and people. We discuss the way selected artworks give expression to the themes or concepts of productive labour, nature and culture, conservation and sustainability, and memory. The artworks include Watjinbuy Marrawilil’s (1980 Carved ancestral figure ceremonial pole, Elizabeth Stops’ (2009/10 Explorations into colonisation, Hossein Valamanesh’s (2008 Memory stick, and AñA Wojak’s (2008 Unread book (in a forgotten language. Our art writing on the works, a practice informed by Bal (2002, Muecke (2008 and Papastergiadis (2004, becomes a conversation between the works and the themes or concepts. As a form of material excess of the most productive kind (Grosz, 2008, p. 7, art seeds a response to that which is in the air waiting to be said of the past, present and future.

  6. Sugar-borate esters--potential chemical agents in prostate cancer chemoprevention.

    Science.gov (United States)

    Scorei, Romulus Ion; Popa, Radu

    2013-07-01

    The potential value of sugar-borate esters (SBEs) in the chemo-preventive therapy of prostate cancer has been reviewed. We propose that SBEs act as boron (B) vehicles, increasing the concentration of borate inside cancer cells relative to normal cells. Increased intracellular concentration of borate activates borate transporters, but also leads to growth inhibition and apoptosis. The effects of SBEs on normal cells are less dramatic because SBEs are naturally-occurring biochemicals, common and abundant in some fruits and vegetables, and also because borate dissociated from SBEs in natural diet doses is easily exported from normal cells. Cancer cell lines that over-express sugar transporters or under-express borate export are potential targets for SBE-based therapy. With regard to efficiency against cancer cells and drug preparation requirements, trigonal cis-diol boric monoesters will be one of the most effective class of SBEs. Because negative correlation exists between borate intake and the incidence of prostate cancer, and because most cancer cells overexpress sugar transporters, SBEs are proposed as a potential chemopreventive avenue in the fight against primary and recurrent prostate cancer.

  7. Effect of ionic interaction of chlorode-borate and iodide-borate on their absorption by Lemna minor L

    Energy Technology Data Exchange (ETDEWEB)

    Thellier, M.; Ayadi, A.; Tromeur, C.

    1967-11-27

    The effect of borate ions on the absorption of chloride and iodide ions by Lemna minor was studied by using the radioactive tracers Cl-36 at 23/sup 0/C with an illumination of 8000 Lux and I-131 at 25.5 C with 600 Lux. The absorbed quantities of the tracer elements were measured with a Geiger counter. The concentrations of sodium chloride solutions tested ranged from 0.055 to 1 mM, those of potassium iodide from 0.04 to 4 mM. While the presence of borate ions in the test solutions of NaCl inhibited the absorption of Cl ions by Lemna minor, only a mild inhibition or none at all was noted in the case of the absorption of I ions. Because of the difference of the cations (sodium in the case of Cl, potassium in the case of I) no direct comparison can be drawn between the absorption of the two halogens. The absorption of I by the plant is thought to proceed by a much simpler mechanism than that of Cl.

  8. Laser spectroscopy of rare earth ions in lead borate glasses and transparent glass-ceramics

    Science.gov (United States)

    Pisarski, W. A.; Grobelny, Ł.; Pisarska, J.; Lisiecki, R.; Dominiak-Dzik, G.; Ryba-Romanowski, W.

    2010-03-01

    Rare earth doped lead borate glasses and transparent glass-ceramics have been studied using optical spectroscopy. Based on the absorption, emission and its decay and the Judd-Ofelt calculations, several radiative and laser parameters for Ln 3+ ( Ln = Pr, Nd, Eu, Dy, Er, Tm) were evaluated. The large values of luminescence lifetime, quantum efficiency of excited state and room temperature peak stimulated emission cross-section suggest efficient laser transitions of Ln 3+ ions in lead borate glasses. The obtained results indicate that lead borate glasses and glass-ceramics containing Ln 3+ ions are promising host matrices for solid-state laser applications.

  9. Photodegradation of thermally modified wood.

    Science.gov (United States)

    Srinivas, Kavyashree; Pandey, Krishna K

    2012-12-01

    Natural wood, being biological material, undergoes rapid degradation by ultraviolet (UV) radiations and other environmental factors under outdoor exposure. In order to protect wood from such degradation, the chemical structure of wood is altered by chemical modification or heat treatment. In the present study, heat treated specimens of rubberwood (Hevea brasiliensis) were exposed to xenon light source in a weather-o-meter for different periods up to 300 h. Photostability of modified and unmodified wood was evaluated in terms of colour and chemical changes. Light coloured untreated wood became dark upon UV irradiation whereas, dark colour of heat treated wood lightened on UV exposure. CIE lightness parameter (L(*)) decreased for untreated wood whereas its value increased for heat treated wood upon irradiation. Other colour coordinates a(*) and b(*) increased with exposure duration for both untreated and heat treated wood. The overall colour change (ΔE(*)) increased for both untreated and heat treated wood. The Fourier Transform Infrared (FTIR) spectroscopic studies revealed severe lignin degradation of heat treated wood due to UV light exposure. Colour changes and FTIR measurements indicate that thermal modification of wood was ineffective in restricting light induced colour changes and photodegradation of wood polymers.

  10. Fatigue Damage in Wood

    DEFF Research Database (Denmark)

    Clorius, Christian Odin; Pedersen, Martin Bo Uhre; Hoffmeyer, Preben;

    1996-01-01

    An investigation of fatigue failure in wood subjected to load cycles in compression parallel to grain is presented. Fatigue failure is found to depend both on the total time under load and on the number of cycles.Recent accelerated fatigue research on wood is reviewed, and a discrepancy between...... failure explanation under fatigue and static load conditions is observed. In the present study small clear specimens of spruce are taken to failure in square wave formed fatigue loading at a stress excitation level corresponding to 80% of the short term strength. Four frequencies ranging from 0.01 Hz...... to 10 Hz are used. The number of cycles to failure is found to be a poor measure of the fatigue performance of wood. Creep, maximum strain, stiffness and work are monitored throughout the fatigue tests. Accumulated creep is suggested identified with damage and a correlation between stiffness reduction...

  11. Precision wood particle feedstocks

    Science.gov (United States)

    Dooley, James H; Lanning, David N

    2013-07-30

    Wood particles having fibers aligned in a grain, wherein: the wood particles are characterized by a length dimension (L) aligned substantially parallel to the grain, a width dimension (W) normal to L and aligned cross grain, and a height dimension (H) normal to W and L; the L.times.H dimensions define two side surfaces characterized by substantially intact longitudinally arrayed fibers; the W.times.H dimensions define two cross-grain end surfaces characterized individually as aligned either normal to the grain or oblique to the grain; the L.times.W dimensions define two substantially parallel top and bottom surfaces; and, a majority of the W.times.H surfaces in the mixture of wood particles have end checking.

  12. Wood for sound.

    Science.gov (United States)

    Wegst, Ulrike G K

    2006-10-01

    The unique mechanical and acoustical properties of wood and its aesthetic appeal still make it the material of choice for musical instruments and the interior of concert halls. Worldwide, several hundred wood species are available for making wind, string, or percussion instruments. Over generations, first by trial and error and more recently by scientific approach, the most appropriate species were found for each instrument and application. Using material property charts on which acoustic properties such as the speed of sound, the characteristic impedance, the sound radiation coefficient, and the loss coefficient are plotted against one another for woods. We analyze and explain why spruce is the preferred choice for soundboards, why tropical species are favored for xylophone bars and woodwind instruments, why violinists still prefer pernambuco over other species as a bow material, and why hornbeam and birch are used in piano actions.

  13. Transition and post-transition metal ions in borate glasses: Borate ligand speciation, cluster formation, and their effect on glass transition and mechanical properties

    Science.gov (United States)

    Möncke, D.; Kamitsos, E. I.; Palles, D.; Limbach, R.; Winterstein-Beckmann, A.; Honma, T.; Yao, Z.; Rouxel, T.; Wondraczek, L.

    2016-09-01

    A series of transition and post-transition metal ion (Mn, Cu, Zn, Pb, Bi) binary borate glasses was studied with special consideration of the cations impact on the borate structure, the cations cross-linking capacity, and more generally, structure-property correlations. Infrared (IR) and Raman spectroscopies were used for the structural characterization. These complementary techniques are sensitive to the short-range order as in the differentiation of tetrahedral and trigonal borate units or regarding the number of non-bridging oxygen ions per unit. Moreover, vibrational spectroscopy is also sensitive to the intermediate-range order and to the presence of superstructural units, such as rings and chains, or the combination of rings. In order to clarify band assignments for the various borate entities, examples are given from pure vitreous B2O3 to meta-, pyro-, ortho-, and even overmodified borate glass compositions. For binary metaborate glasses, the impact of the modifier cation on the borate speciation is shown. High field strength cations such as Zn2+ enhance the disproportionation of metaborate to polyborate and pyroborate units. Pb2+ and Bi3+ induce cluster formation, resulting in PbOn- and BiOn-pseudophases. Both lead and bismuth borate glasses show also a tendency to stabilize very large superstructural units in the form of diborate polyanions. Far-IR spectra reflect on the bonding states of modifier cations in glasses. The frequency of the measured cation-site vibration band was used to obtain the average force constant for the metal-oxygen bonding, FM-O. A linear correlation between glass transition temperature (Tg) and FM-O was shown for the metaborate glass series. The mechanical properties of the glasses also correlate with the force constant FM-O, though for cations of similar force constant the fraction of tetrahedral borate units (N4) strongly affects the thermal and mechanical properties. For paramagnetic Cu- and Mn-borate glasses, N4 was determined

  14. Methane from wood

    Energy Technology Data Exchange (ETDEWEB)

    Schulz, T. F.; Barreto, L.; Kypreos, S.; Stucki, S

    2005-07-15

    The role of wood-based energy technologies in the Swiss energy system in the long-term is examined using the energy-system Swiss MARKAL model. The Swiss MARKAL model is a 'bottom-up' energy-systems optimization model that allows a detailed representation of energy technologies. The model has been developed as a joint effort between the Energy Economics Group (EEG) at Paul Scherrer Institute PSI) and the University of Geneva and is currently used at PSI-EEG. Using the Swiss MARKAL model, this study examines the conditions under which wood-based energy technologies could play a role in the Swiss energy system, the most attractive pathways for their use and the policy measures that could support them. Given the involvement of PSI in the ECOGAS project, especial emphasis is put on the production of bio-SNG from wood via gasification and methanation of syngas and on hydrothermal gasification of woody biomass. Of specific interest as weIl is the fraction of fuel used in passenger cars that could be produced by locally harvested wood. The report is organized as follows: Section 2 presents a brief description of the MARKAL model. Section 3 describes the results of the base case scenario, which represents a plausible, 'middle-of-the-road' development of the Swiss energy system. Section 4 discusses results illustrating the conditions under which the wood-based methanation technology could become competitive in the Swiss energy market, the role of oil and gas prices, subsidies to methanation technologies and the introduction of a competing technology, namely the wood-based Fischer-Tropsch synthesis. FinaIly, section 5 outlines some conclusions from this analysis. (author)

  15. TCP HolyWood

    OpenAIRE

    Oscar Núñez Mori

    2005-01-01

    We introduce a new end-to-end, sender side Transport Control Protocol called TCP HolyWood or in short TCP-HW. In a simulated wired environment, TCP HolyWood outperforms in average throughput, three of the more important TCP protocols ever made, we are talking about TCP Reno, TCP Westwood, and TCP Vegas; and in average jitter to TCP Reno and TCP Vegas too. In addition, according to Jain’s index, our proposal is as fair as TCP Reno, the Standard. Apresentamos um novo Protocolo de Controle de...

  16. Variation in root wood anatomy

    NARCIS (Netherlands)

    Cutler, D.F.

    1976-01-01

    Variability in the anatomy of root wood of selected specimens particularly Fraxinus excelsior L. and Acer pseudoplatanus L. in the Kew reference microscope slide collection is discussed in relation to generalised statements in the literature on root wood anatomy.

  17. False "highlighting" with Wood's lamp.

    Science.gov (United States)

    Silverberg, Jonathan I; Silverberg, Nanette B

    2014-01-01

    Wood's lamp evaluation is used to diagnose pigmentary disorders. For example, vitiligo typically demonstrates lesional enhancement under Wood's lamp evaluation. Numerous false positive enhancing lesions can be noted in the skin. We describe a 5-year-old Hispanic boy who had painted his face with highlighter, producing enhancing lesions under Wood's lamp. Physicians who use Wood's lamp should be aware that the appearance of markers and highlighter can mimic that of true clinical illnesses.

  18. Elastic properties of Li+ doped lead zinc borate glasses

    Science.gov (United States)

    Rajaramakrishna, R.; Lakshmikantha, R.; Anavekar, R. V.

    2014-04-01

    Glasses in the system 0.25PbO-(0.25-x) ZnO-0.5B2O3-xLi2O have been prepared by the melt quenching technique. Elastic properties, DSC studies have been employed to study the role of Li2O in the present glass system. Elastic properties and Debye temperature have been determined using pulsed echo ultrasonic interferometer operating at 10MHz. Sound velocities Vl, Vt and elastic moduli decrease up to 5 mol% and then gradually increase with increase in Li2O concentration. Debye temperature and the glass transition temperature decreases with increase in Li2O. Densities remains almost constant up to 15 mol% Li2O concentration and increases monotonically while the molar volume decreases with the increase of Li2O concentration. The results are discussed in view of the borate structural network and dual role of Zn and Pb in these glasses.

  19. Structural investigation of Zn doped sodium bismuth borate glasses

    Science.gov (United States)

    Bhatia, V.; Kumar, D.; Singh, D.; Singh, S. P.

    2016-05-01

    A series of Bismuth Borate Oxide Glass samples with composition x(ZnO):(15-x)Na2O:15Bi2O3:70B2O3 (variation in x is from 6 to 12 mole %) have been prepared by conventional melt quenching technique. All the chemicals used were of Analytical Grade. In order to verify the amorphous nature of the prepared samples the X-Ray Diffraction (XRD) was done. The physical and structural properties have been explored by using the techniques such as density, molar volume and FTIR in order to understand the effect of alkali and transition metal ions on the structure of these glasses. The results obtained by these techniques are in good agreement to one another and with literature as well. With the increase in the content of ZnO, the increase in density and some variations in structural coordination (ratio of BO3 & BO4 structural units) have been observed.

  20. Influence of sodium borate on the early age hydration of calcium sulfoaluminate cement

    Energy Technology Data Exchange (ETDEWEB)

    Champenois, Jean-Baptiste; Dhoury, Mélanie [CEA, DEN, DTCD, SPDE, F-30207 Bagnols-sur-Cèze Cedex (France); Cau Dit Coumes, Céline, E-mail: celine.cau-dit-coumes@cea.fr [CEA, DEN, DTCD, SPDE, F-30207 Bagnols-sur-Cèze Cedex (France); Mercier, Cyrille [LMCPA, Université de Valenciennes et du Hainaut Cambrésis, 59600 Maubeuge (France); Revel, Bertrand [Centre Commun de Mesure RMN, Université Lille1 Sciences Technologies, Cité Scientifique, 59655 Villeneuve d' Ascq Cedex (France); Le Bescop, Patrick [CEA, DEN, DPC, SECR, F-91192 Gif-sur-Yvette (France); Damidot, Denis [Ecole des Mines de Douai, LGCgE-GCE, 59508 Douai (France)

    2015-04-15

    Calcium sulfoaluminate (CSA) cements are potential candidates for the conditioning of radioactive wastes with high sodium borate concentrations. This work thus investigates early age hydration of two CSA cements with different gypsum contents (0 to 20%) as a function of the mixing solution composition (borate and NaOH concentrations). Gypsum plays a key role in controlling the reactivity of cement. When the mixing solution is pure water, increasing the gypsum concentration accelerates cement hydration. However, the reverse is observed when the mixing solution contains sodium borate. Until gypsum exhaustion, the pore solution pH remains constant at ~ 10.8, and a poorly crystallized borate compound (ulexite) precipitates. A correlation is established between this transient precipitation and the hydration delay. Decreasing the gypsum content in the binder, or increasing the sodium content in the mixing solution, are two ways of reducing the stability of ulexite, thus decreasing the hydration delay.

  1. "Kasahhi ajakirjanik" Borat : tapvad kultuurierinevused on pööraselt naljakad / Margus Välja

    Index Scriptorium Estoniae

    Välja, Margus, 1958-

    2006-01-01

    Briti koomiku Sacha Baron Coheni loodud peategelasega USA film "Borat - kultuurialased õppetunnid Ameerikast abiks suursuguse Kasahstani riigi ülesehitamisel" : režissöör Larry Charles. Film jooksis ka Haapsalu kultuurikeskuses

  2. Preparation and Characterization of Low-Dielectric Glass Composite with Aluminum Borate

    Science.gov (United States)

    Jean, Jau-Ho; Hwang, Shiang-Po

    1994-10-01

    The effect of aluminum borate ( Al18B4O33) on crystallization and thermal expansion of Pyrex borosilicate glass has been studied. X-ray diffraction (XRD) results show that with 40 vol% aluminum borate, the precipitation of cristobalite in the Pyrex borosilicate glass is completely inhibited. This result is further evidenced by the linear thermal expansion measurement in which, in contrast to the system without aluminum borate, the thermal expansion coefficient remains unchanged with sintering time and is close to that of silicon, 3×10-6 K-1. Moreover, the composite with 40 vol% aluminum borate has a dielectric constant of 5.2 and a dielectric loss of 0.8% at 1 MHz.

  3. Structural properties of molybdenum-lead-borate glasses

    Science.gov (United States)

    Rada, M.; Rada, S.; Pascuta, P.; Culea, E.

    2010-11-01

    Glasses and glass ceramics in the system xMoO 3·(100 - x)[3B 2O 3·PbO] with 0 ≤ x ≤ 30 mol% have been prepared from melt quenching method and characterized by means of X-ray diffraction, FTIR, UV-VIS and EPR spectroscopy. We have examined and analyzed the effects of systematic molybdenum ions intercalation on lead-borate glasses and glass ceramics with interesting results. The observations present in these mechanisms show the lead ions bonded ionic have a strong affinity towards [BO 3] units containing non-bridging oxygens and [MoO 4] 2- molybdate units. The pronounced affinity towards molybdate anions yields the formation of the PbMoO 4 crystalline phase. Then, the excess of oxygen can be supported into the glass network by the formation of [MoO 6] and [Mo 2O 7] structural units. Pb 2+ ions with 6s 2 configuration show strong absorption in the ultraviolet due to parity allowed s 2-sp transition and yield an absorption band centered at about 310 nm. The changes in the features of the absorption bands centered at about 310 nm can be explained as a consequence of the appearance of additional absorption shoulder due to photoinduced color centers in the glass such as the formation of borate-molybdate and lead-molybdate paramagnetic defect centers in the glasses. The concentration of molybdenum ions influences the shape and width of the EPR signals located at g ˜ 1.86, 1.91 and 5.19. The microenvironment of molybdenum ions in glasses is expected to have mainly sixfold coordination. However, there is a possibility of reduction of a part of molybdenum ions from the Mo 6+ to the Mo 5+ and Mo 4+ to the Mo 3+ states.

  4. Recent advances in trivalent f-element borate chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Polinski, Matthew J. [Notre Dame Univ., IN (United States). Dept. of Chemistry and Biochemistry; Alekseev, Evgeny V. [Forschungszentrum Juelich GmbH (Germany). Inst. for Energy and Climate Research (IEK-6); RWTH Aachen Univ. (Germany). Inst. fuer Kristallographie; Depmeier, Wulf [Kiel Univ. (Germany). Inst. fuer Geowissenschaften; Albrecht-Schmitt, Thomas E. [Florida State Univ., Tallahassee, FL (United States). Dept. of Chemistry and Biochemistry

    2013-11-01

    The reactions of LnCl{sub 3} . 6 H{sub 2}O with molten boric acid result in the formation of three different products depending on the identity of the lanthanide metal. The analogous reactions using AnCl{sub 3} . 6 H{sub 2}O (An = Pu(III), Am(III), and Cm(III)) with molten boric acid under the same conditions do not yield the same results as those of the 4f series or of the other 5f elements. For the most part, the actinide products obtained have no lanthanide analogues making them unique compounds. Furthermore, the reactions of LnX{sub 3} . yH{sub 2}O (X = Br, I) (Ln = La-Nd) with molten boric acid results in the formation of two products. The analagous set of reactions was performed with PuX{sub 3} . yH{sub 2}O (X = Br, I) which, yet again, gave rise to completely novel compounds. All of these compounds are three-dimensional framework structures comprised of sheets. These sheets are made up of both BO{sub 3} and BO{sub 4} units which are arranged in such a manner that creates triangular holes in which the lanthanide or actinide sites reside. The borate units of the triangular holes provide six oxygen atoms that coordinate in the equatorial region resulting in unique nine- and/or ten-coordinate geometries. The similarities and differences between the 4f and 5f borate compounds are discussed with particular emphasis on the periodic trends of this system. (orig.)

  5. Optical absorption and fluorescence properties of $Er^{3+}$ in sodium borate glass

    OpenAIRE

    Ratnakaram, YC; J.Lakshmi; Chakradhar, RPS

    2005-01-01

    Spectroscopic properties of $Er^{3+}$ ions in sodium borate glass have been studied. The indirect and direct optical band gaps $(E_{opt})$ and energy level parameters (Racah $(E^{1}, E^{2} and E^{3})$, spin-orbit $(\\xi_{4f})$ and configurational interaction (\\alpha)) are evaluated. Spectral intensities for various absorption bands of $Er^{3+}$ doped sodium borate glass are calculated. Using Judd-Ofelt intensity parameters $(\\Omega_{2},\\Omega_{4}, \\Omega_{6})$, radiative transition probabiliti...

  6. Radiation Shielding Properties Comparison of Pb-Based Silicate, Borate, and Phosphate Glass Matrices

    OpenAIRE

    Suwimon Ruengsri

    2014-01-01

    Theoretical calculations of mass attenuation coefficients, partial interactions, atomic cross-section, and effective atomic numbers of PbO-based silicate, borate, and phosphate glass systems have been investigated at 662 keV. PbO-based silicate glass has been found with the highest total mass attenuation coefficient and then phosphate and borate glasses, respectively. Compton scattering has been the dominate interaction contributed to the different total attenuation coefficients in each of th...

  7. Wood dust exposure in wood industry and forestry.

    Science.gov (United States)

    Puntarić, Dinko; Kos, Ankica; Smit, Zdenko; Zecić, Zeljko; Sega, Kresimir; Beljo-Lucić, Ruzica; Horvat, Dubravko; Bosnir, Jasna

    2005-06-01

    The aim of the study was to determine occupational exposure in Croatian wood processing industry and forest workers to harmful effects of wood dust on the risk of nose, nasal cavity and lung carcinoma. Mass concentrations of respirable particles and total wood dust were measured at two wood processing plants, three woodwork shops, and one lumbering site, where 225 total wood dust samples and 221 respirable particle samples were collected. Wood dust mass concentration was determined by the gravimetric method. Mass concentrations exceeding total wood dust maximal allowed concentration (MAC, 3 mg/m3) were measured for beechwood and oakwood dust in 38% (79/206) of study samples from wood processing facilities (plants and woodwork shops). Mass concentrations of respirable particles exceeding MAC (1 mg/m3) were recorded in 24% (48/202) of samples from wood processing facilities (mean 2.38 +/- 2.08 mg/m3 in plants and 3.6 +/- 2.22 mg/m3 in woodwork shops). Thus, 13% (27/206) of work sites in wood processing facilities failed to meet health criteria according to European guidelines. Launching of measures to reduce wood dust emission to the work area is recommended.

  8. Tannins in tropical woods

    Energy Technology Data Exchange (ETDEWEB)

    Doat, J.

    1978-01-01

    A preliminary study was made of the chemistry of pyrogallol- and catecholtannins, their general properties and methods of extraction and determination. Three methods of estimation - Lowenthal, powdered hide and spectrophotometry - were compared using two control solutions, four samples of wood and one of bark. Using the empirical powdered hide method, tannins of both types were estimated in wood and bark of various tropical species (some separately and some as a mixture), Moroccan oaks (Quercus suber and Q. ilex), and European oak 9Q. petraea). Further tests were made on the wood and bark of the two mangrove species, Rhizophora mangle and R. racemosa, by subjecting them to successive extraction with a range of solvents. None of the woods tested had as much as the 10% of tannins considered necessary in economic sources. The bark of the two mangroves, of Eucalyptus urophylla and of Prosopis africana had tannin contents over 10% and the latter two species had very favorable tannin/non-tannin ratios. All the tropical species, with the probable exception of E. urophylla, had only catecholtannins. Only the oaks and E. urophylla bark gave positive results when tested for gallotannins.

  9. Grant Wood: "American Gothic."

    Science.gov (United States)

    Fitzgerald, Diane M.

    1988-01-01

    Presents a lesson plan which exposes students in grades 10-12 to the visual symbols and historical references contained in Grant Wood's "American Gothic." Includes background information on the artist and the painting, instructional strategies, a studio activity, and evaluation criteria. (GEA)

  10. Wood waste in Europe

    Energy Technology Data Exchange (ETDEWEB)

    Matos, O.; Ribeiro, R. [Biomass Centre for Energy - CBE, Miranda do Corvo (Portugal)

    1997-12-31

    The energy policy of the EC, as well as most of member states points to a sizeable increase of energy production based on renewable energy sources, wood, wood residues, agricultural residues, energy crops including SRF, organic sludges, solid residues, etc. Most recent goals indicate a desirable duplication of today`s percentage by 2010. The reasons for this interest, besides diversification of sources, less dependence on imported fuels, use of endogenous resources, expected decrease of fossil fuel reserves, use of available land, additional employment and income for rural communities, etc., are related to important environmental benefits namely in terms of emissions of hot house gases. Wood waste, resulting from forest operations, cleaning, cultural and final cuttings, and from wood based industries, constitute a special important resource by reason of quality and availability. In addition to this they do not require additional land use and the removal is beneficial. In the run-up to the becoming December`s 1997 `Climate Change Summit` in Kioto, there is mounting pressure on companies to plan on carbon cuts. (author) 6 refs., 1 tab.

  11. Synthesis and Characterization of Zinc Borate Nanowhiskers and Their Inflaming Retarding Effect in Polystyrene

    Directory of Open Access Journals (Sweden)

    Pingqiang Gao

    2015-01-01

    Full Text Available Zinc borate nanowhiskers 4ZnO·B2O3·H2O were in situ successfully synthesized via one-step precipitation reaction. A set of experiments was performed to evaluate the influence of reaction temperature. Increasing the temperature up to 70°C led to the high purity of zinc borate nanowhiskers with a monoclinic crystal structure measuring 50 nm to 100 nm in diameter and approximately 1 µm in length. However, higher temperature decreases the crystallization due to the emergence of other styles of zinc borate. Flame-resistant nanocomposites of polystyrene and zinc borate nanowhiskers were also successfully synthesized. The samples were investigated by XRD, FESEM, FTIR, and TG. The mechanical properties of the composites were also tested. The incorporation of zinc borate nanowhiskers improved the thermal and mechanical properties for polystyrene. FESEM images show that zinc borate nanowhiskers increased the smoothness of composites. The composites presented good responsive behavior in relation to LOI (limiting oxygen index allowing them to be suitable for green flame retardants.

  12. Partial transparency of compressed wood

    Science.gov (United States)

    Sugimoto, Hiroyuki; Sugimori, Masatoshi

    2016-05-01

    We have developed novel wood composite with optical transparency at arbitrary region. Pores in wood cells have a great variation in size. These pores expand the light path in the sample, because the refractive indexes differ between constituents of cell and air in lumen. In this study, wood compressed to close to lumen had optical transparency. Because the condition of the compression of wood needs the plastic deformation, wood was impregnated phenolic resin. The optimal condition for high transmission is compression ratio above 0.7.

  13. A new shock wave assisted wood preservative injection system

    Science.gov (United States)

    Rao, K. S.; Ravikumar, G.; Lai, Ram; Jagadeesh, G.

    Preservative treatment of many tropical hard woods and bamboo pose severe problem. A number of wood preservatives (chemical formulations toxic to wood decay/ destroying organisms like fungi, wood destroying termites, marine borers etc.) and wood impregnating techniques are currently in use for improving bio resistance of timber and bamboo and thereby enhancing service life for different end uses. How ever, some species of tropical hardwoods and many species of bamboo are difficult to treat, posing technical problems. In this paper we report preliminary results of treatment of bamboo with a novel Shockwave assisted injection treatment. Samples (30×2.5×1.00 cm) of an Indian species of bamboo Dendrocalamus strictus prepared from defect free culms of dry bamboo are placed in the driven section of a vertical shock tube filled with the 4Coppepr-Chrome-Arsenic(CCA) preservative solution.The bamboo samples are subjected to repeated shock wave loading (3 shots) with typical over pressures of 30 bar. The results from the study indicate excellent penetration and retention of CCA preservative in bamboo samples. The method itself is much faster compared to the conventional methods like pressure treatment or hot and cold process.

  14. A novel method for preparing ultra-fine alumina-borate oxide fibres via an electrospinning technique

    Science.gov (United States)

    Dai, Hongqin; Gong, Jian; Kim, Hakyong; Lee, Doukrae

    2002-10-01

    Alumina-borate/PVA composite fibres were prepared using sol-gel processing and an electrospinning technique. After calcination of the thin fibres, ultra-fine fibres of alumina-borate oxide with a diameter of about 550 nm could be prepared. The fibres were characterized by SEM, XRD and FT-IR. The results showed that the crystalline phase and morphology of alumina-borate fibres were largely influenced by the calcination temperature.

  15. Nanoscale in Wood, Nanowood and Wood-Inorganic Nanocomposites

    Institute of Scientific and Technical Information of China (English)

    Zhao Guangjie; Lu Wenhua

    2003-01-01

    In order to introduce nano science and technology (NST) into the research field of wood science and technology, andpromote the research of wood science and wood-inorganic composites to nanoscale, some new concepts, such as the nano space inwood, nano structure units of wood and nanowood are put forward in this paper based on the layer structure of wood cell wall and thepile-up model of its main components. Furthermore, the process of preparing nanowood is discussed, and wood-inorganic nanocom-posites may be operated in three ways with wood (matrix) and inorganic filler phase in 0-2, 0-3 or 2-3 dimensions respectively. Thefollowing results are obtained: (1) The nanoscale voids in wood indicate that wood has inherent space to accommodate nanosizedmaterials, such as nanoparticles, nanotubes and nanosticks; (2) According to the size from top down, the nano structure units in woodcan be classified as: nanolayers, nano CMF (cellulose microfibril) and matrix, nano crystallite units and cellulose chain clusters, andthese can theoretically form nanowood; (3) The preparation of wood-inorganic nanocomposites can be operated on 0-2, 0-3 or 2-3dimensions.

  16. Buffering Capacity of Fast-Growing Species and Curing Time of UF Resin Modified With Zinc Borate and Monoammonium Phosphate

    Directory of Open Access Journals (Sweden)

    Izran Kamal

    2010-01-01

    Full Text Available Problem statement: Occupying a suitable hot pressing time for particleboard fabrication seems very tricky for manufacturers of the wood-based panel. Longer or shorter pressing times can affect physical and mechanical properties of the produced particleboards and that is why extra care should be given on this matter. Longer pressing time can cause resin in a particleboard to over-cure whereas shorter pressing time can cause insufficient curing of the resin. Determination of hot pressing time is influenced by the type of filler and chemical used. The acidity or alkalinity of a filler and chemical can lengthen or shorten the time taken by the resin to cure. These parameters are usually assessed using buffering capacity test and curing time test. In this study, the two analyses were occupied to assess acidity or alkalinity of kenaf, Shorea macrophylla and Acacia mangium as well as the effect of fire retardants (zinc borate and monoammonium phosphate to the curing rate of urea formaldehyde resin. Determine acidity or alkalinity of the wood particles through buffering capacity test. The effect of the fire retardants to the curing of Urea Formaldehyde (UF resin was also studied. Approach: For buffering capacity test, the wood particles were extracted. Then, the extracts were separated into two parts. One part was tested with sodium hydroxide (NaOH and another part was tested with sulphuric acid (H2SO4. Sodium hydroxide was added into the extracts until they reached pH 11. The other part was added with sulphuric acid until they reached pH 3. The pH value was recorded each time 5 mL chemicals added. The acidity of the plants was observed by looking at the volume of sulphuric acid needed to reduce their pH to 3, whereas alkalinity was evaluated by looking at the volume of sodium hydroxide used to increase their pH to 11. Curing times of UF resin added or not added with fire retardants were calculated in second (sec. Results: Buffering capacity study

  17. Liquid Effluent Retention Facility

    Data.gov (United States)

    Federal Laboratory Consortium — The Liquid Effluent Retention Facility (LERF) is located in the central part of the Hanford Site. LERF is permitted by the State of Washington and has three liquid...

  18. Drug Retention Times

    Energy Technology Data Exchange (ETDEWEB)

    Center for Human Reliability Studies

    2007-05-01

    The purpose of this monograph is to provide information on drug retention times in the human body. The information provided is based on plausible illegal drug use activities that might be engaged in by a recreational drug user

  19. Drug Retention Times

    Energy Technology Data Exchange (ETDEWEB)

    Center for Human Reliability Studies

    2007-05-01

    The purpose of this monograph is to provide information on drug retention times in the human body. The information provided is based on plausible illegal drug use activities that might be engaged in by a recreational drug user.

  20. Compressive Fatigue in Wood

    DEFF Research Database (Denmark)

    Clorius, Christian Odin; Pedersen, Martin Bo Uhre; Hoffmeyer, Preben;

    1999-01-01

    An investigation of fatigue failure in wood subjected to load cycles in compression parallel to grain is presented. Small clear specimens of spruce are taken to failure in square wave formed fatigue loading at a stress excitation level corresponding to 80% of the short term strength. Four...... frequencies ranging from 0.01 Hz to 10 Hz are used. The number of cycles to failure is found to be a poor measure of the fatigue performance of wood. Creep, maximum strain, stiffness and work are monitored throughout the fatigue tests. Accumulated creep is suggested identified with damage and a correlation...... is observed between stiffness reduction and accumulated creep. A failure model based on the total work during the fatigue life is rejected, and a modified work model based on elastic, viscous and non-recovered viscoelastic work is experimentally supported, and an explanation at a microstructural level...

  1. Ion-conductivity of thin film Li-Borate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Abouzari, M.R.S.

    2007-12-17

    In this thesis, the specific conductivity of ion-sputtered lithium borate thin films is studied. To this end, lithium borate glasses of the composition yLi{sub 2}O.(1-y)B{sub 2}O{sub 3} with y=0.15, 0.20, 0.25, and 0.35 were produced as sputter targets. Films with thicknesses between 7 nm and 700 nm are deposited on silicon substrate between two AlLi electrodes. Conductivity spectra have been taken over a frequency range of 5 Hz to 2 MHz. The measurements were performed at different temperatures between 40 C and 350 C depending on the thickness and the composition of the films. The following results are derived by studying the conductivities of the films: i) The specific dc conductivity of layers with thicknesses larger than 150 nm is independent of their thicknesses; we call these layers 'thick films' and consider their conductivity as the 'base conductivity'. ii) The specific dc conductivity of layers with thicknesses smaller than 150 nm, called 'thin films', depends on the layer thickness. A nontrivial enhancement of the specific dc conductivity about three orders of magnitude for y=0.15, 0.2, and 0.25 is observed. iii) The base conductivity depends on y and at 120 C it varies between 4 x 10{sup -10} {omega}{sup -1}cm{sup -1} and 2.5 x 10{sup -6} {omega}{sup -1}cm{sup -1} when y varies between 0.15 and 0.35, whereas the maximum value of the specific dc conductivity of extremely thin films (with a thickness of some nanometre) seems to be independent of y and equals to the specific dc conductivity of layers with y= 0.35. Furthermore, we found in this work a physical interpretation of the so-called 'Constant Phase Element' (CPE) which is widely used in equivalent circuits for ionic conductors. This element describes correctly the depressed impedance semicircles observed in impedance spectroscopy. So far, this effect is sometimes attributed to the surface roughness. We have shown not only the invalidity of this approach, but

  2. Structure-property relations in lanthanide borate glasses

    Science.gov (United States)

    Chakraborty, I. N.; Day, D. E.; Lapp, J. C.; Shelby, J. E.

    1985-01-01

    Glass formation in the system Ln2O3-B2O3 (Ln = Nd, Sm) was studied. Glasses could be formed in the range from 0 to 28 mol pct rare-earth oxide (Ln2O3), but liquid immiscibility in these systems limits the range of homogeneous glasses to 0 to 1.5 and 25 to 28 mol pct Ln2O3. The infrared spectra indicate that the rare-earth-rich glasses are structurally similar to rare-earth metaborates (LnB3O6) which contain (B3O6)-infinity chains. The variation in density, transformation temperature, thermal expansion coefficient, and transformation-range viscosity of these glasses with the size of the rare-earth ion is discussed. Glasses near the metaborate composition have a transformation temperature of about 700 C, which is high for binary borate glasses. Glasses could not be formed in the systems Eu2O3-, Gd2O3-, Ho2O3-, and Er2O3-B2O3, even by quenching at 1300 C/s. The sudden lack of glass formation in the system Ln2O3-B2O3 with Ln(3+) ions smaller than Sm(3+) is explained on the basis of the size effect of the Ln(3+) ion on the stability of (B3O6)-infinity chains in these metaborates.

  3. The local structure of europium-lead-borate glass ceramics

    Science.gov (United States)

    Rada, S.; Pascuta, P.; Culea, M.; Maties, V.; Rada, M.; Barlea, M.; Culea, E.

    2009-04-01

    Glass ceramics in the xEu 2O 3(100 - x)[3B 2O 3·PbO] system with 0 ⩽ x ⩽ 50 mol% have been prepared using the melt quenching method, succeeded by heat treatment applied at 625 °C and 675 °C, respectively, for 48 h. The influence of europium ions on structural behavior of the lead-borate glass ceramics has been investigated using infrared spectroscopy and DFT calculations. The addition of europium ions into the host glass ceramics matrix leads to an increase of the glass network polymerization due to the replacement of B sbnd O sbnd B bonds by the more resistant B sbnd O sbnd Pb bonds. The structural evolution of the studied glass ceramics with the gradual increase of the europium oxide content up to 50 mol% could be explained by considering that the excess of oxygen may be accommodated by the formation of [PbO 4] structural units. Then, the formation of different ionic complexes of the lead ions will decrease the rate of crystal growth and the conversion of the glass into crystalline material becomes more difficult, in agreement to the X-ray data.

  4. Spectroscopic properties of the Ce-doped borate glasses

    Science.gov (United States)

    Kindrat, I. I.; Padlyak, B. V.; Mahlik, S.; Kukliński, B.; Kulyk, Y. O.

    2016-09-01

    The EPR, optical absorption and photoluminescence (emission and excitation) spectra as well as decay kinetics of a series of the Ce-doped glasses with Li2B4O7, LiKB4O7, CaB4O7, and LiCaBO3 compositions have been investigated and analysed. The borate glasses were obtained from the corresponding polycrystalline compounds in the air atmosphere, using standard glass technology. The EPR signals of the isolated Ce3+ and pair Ce3+-Ce3+ centres, coupled by magnetic dipolar and exchange interactions were registered at liquid helium temperatures. The characteristic for glass host broad bands corresponding to the 4f → 5d transitions of the Ce3+centres have been observed in the optical absorption and photoluminescence (emission and excitation) spectra. The obtained luminescence decay curves can be satisfactory described by exponential function with lifetimes in the 19.8-26.1 ns range, which depend on the basic glass composition. The local structure of Ce3+ centres in the investigated glasses has been considered and discussed.

  5. Structure modeling of terbium doped strontium-lanthanum borate

    Institute of Scientific and Technical Information of China (English)

    A. Shyichuk; S. Lis; G. Meinrath

    2014-01-01

    Terbium doped strontium-lanthanum borate, Sr3La2(BO3)4:Tb (SLB), was studied by semi-empirical computational ap-proaches using PM6 parametrization and the SPARKLE model for lanthanide(III) (Ln(III)) cations. The focus of interest was on structural aspects, e.g. the cell parameters and distribution of dopant ions between various sites as a function of dopant concentration. The cell linear dimensions were calculated to decrease linearly with increasing dopant molar concentration. SLB offered two sites for the dopant. Calculations predicted that one of these sites should be preferred by the Tb(III) dopant. The optimized cell dimensions as well as the total energies differed for structures with dopant exclusively in site 1 or site 2. Computational predictions were tested against experimental results obtained for SLB synthesized by sol-gel method varying the dopant concentration. The agreement be-tween experimental and computational results was found sufficiently promising to continue the computational studies.

  6. Crystal chemical characterization of mullite-type aluminum borate compounds

    Science.gov (United States)

    Hoffmann, K.; Hooper, T. J. N.; Zhao, H.; Kolb, U.; Murshed, M. M.; Fischer, M.; Lührs, H.; Nénert, G.; Kudějová, P.; Senyshyn, A.; Schneider, H.; Hanna, J. V.; Gesing, Th. M.; Fischer, R. X.

    2017-03-01

    Al-rich aluminum borates were prepared by different synthesis routes using various Al/B ratios, characterized by diffraction methods, spectroscopy and prompt gamma activation analysis. The 11B NMR data show a small amount of BO4 species in all samples. The chemical analysis indicates a trend in the Al/B ratio instead of a fixed composition. Both methods indicate a solid solution Al5-xB1+xO9 where Al is substituted by B in the range of 1-3%. The structure of B-rich Al4B2O9 (C2/m, a=1488 pm, b=553 pm, c=1502 pm, ß=90.6°), was re-investigated by electron diffraction methods, showing that structural details vary within a crystallite. In most of the domains the atoms are orderly distributed, showing no signal for the postulated channel oxygen atom O5. The absence of O5 is supported by density functional theory calculations. Other domains show a probable disordered configuration of O5 and O10, indicated by diffuse scattering along the b direction.

  7. Ground Wood Fiber Length Distributions

    OpenAIRE

    Lauri Ilmari Salminen; Sari Liukkonen; Alava, Mikko J.

    2014-01-01

    This study considers ground wood fiber length distributions arising from pilot grindings. The empirical fiber length distributions appear to be independent of wood fiber length as well as feeding velocity. In terms of mathematics the fiber fragment distributions of ground wood pulp combine an exponential distribution for high-length fragments and a power-law distribution for smaller lengths. This implies that the fiber length distribution is influenced by the stone surface. A fragmentation-ba...

  8. Polarized localization and borate-dependent degradation of the Arabidopsis borate transporter BOR1 in tobacco BY-2 cells [v1; ref status: indexed, http://f1000r.es/kv

    Directory of Open Access Journals (Sweden)

    Noboru Yamauchi

    2013-09-01

    Full Text Available In Arabidopsis the borate transporter BOR1, which is located in the plasma membrane, is degraded in the presence of excess boron by an endocytosis-mediated mechanism. A similar mechanism was suggested in rice as excess boron decreased rice borate transporter levels, although in this case whether the decrease was dependent on an increase in degradation or a decrease in protein synthesis was not elucidated. To address whether the borate-dependent degradation mechanism is conserved among plant cells, we analyzed the fate of GFP-tagged BOR1 (BOR1-GFP in transformed tobacco BY-2 cells. Cells expressing BOR1-GFP displayed GFP fluorescence at the plasma membrane, especially at the membrane between two attached cells. The plasma membrane signal was abolished when cells were incubated in medium with a high concentration of borate (3 to 5 mM. This decrease in BOR1-GFP signal was mediated by a specific degradation of the protein after internalization by endocytosis from the plasma membrane. Pharmacological analysis indicated that the decrease in BOR1-GFP largely depends on the increase in degradation rate and that the degradation was mediated by a tyrosine-motif and the actin cytoskeleton. Tyr mutants of BOR1-GFP, which has been shown to inhibit borate-dependent degradation in Arabidopsis root cells, did not show borate-dependent endocytosis in tobacco BY-2 cells. These findings indicate that the borate-dependent degradation machinery of the borate transporter is conserved among plant species.

  9. A new nanosensor composed of laminated samarium borate and immobilized laccase for phenol determination

    Science.gov (United States)

    Hu, Ping; Zhou, Xinlin; Wu, Qingsheng

    2014-02-01

    A new nanosensor composed of laminated samarium borate and immobilized laccase was developed for phenol determination. The laminated samarium borate was synthesized by a mild solid-state-hydrothermal (S-S-H) method without any surfactant or Template. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM) were used to characterize the samples. The morphology of the as-prepared materials was characterized by SEM, which shows that laminated samarium borate are uniform nanosheets with a layer-by-layer self-assembled single-crystal structure. These laminated samarium borate have typical diameters of 3 ~ 5 μm and the thickness of each layer is in the range of 10 ~ 80 nm. And then, these SmBO3 multilayers were used to immobilize the laccase. The proposed nanosensor composed of laminated samarium borate and immobilized laccase was successfully developed for phenol determination. Cyclic voltammetry were used to study the nanosensor. The proposed nanosensor displayed high sensitivity toward phenolic compounds. The linearity of the nanosensor for the detection of hydroquinone was obtained from 1 to 50 μM with a detection limit of 3 × 10-7 M (based on the S/N = 3).

  10. Syrthesis and properties of nickel borate acylate as a new rubber-steel cord adhesion promoter

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The synthetic method of nickel borate acylate (NBA), a kind of rubber-steel cord adhesion promoter (AP), through nickel carbonate, borate and mixed carboxylic acid was studied. The preparation of nickel carbonate could be performed through reaction of nickel sulfate with sodium carbonate in aqueous solution,in which fractional conversion of nickel was more than 99.9%. The mixed nickel carboxylate was prepared by the reaction of nicke carbonate with isooctanoic acid and acetic acid, under strong stirring for 2 h, the mole ratio of these chemicals were 1: 1: 1.1 respectively, and water should be removed completely by adding of inert organic solvent after reaction was finished so as to avoid hydrolysis of tributyl borate in the second reaction.NBA was synthesizec by reaction of mixed nickel carboxylate with tributyl borate under strong stirring at 200-250 ℃ for 6 h. By detection and comparison with 680C product from Manobond Company of England, the NBA synthesized through isooctanoic acid and tributyl borate was very similar to product 680C in IR data,300% fixed extension strength, tensile strength, hardness and cure curve, and was slightly lower than those ofproduct 680C in tensile failure extensibility and hot air aging. The experimental results show that the preparedNBA can be used as robber-steel cord AP.

  11. 77 FR 74883 - Aging Management of Stainless Steel Structures and Components in Treated Borated Water; Revision 1

    Science.gov (United States)

    2012-12-18

    ... COMMISSION Aging Management of Stainless Steel Structures and Components in Treated Borated Water; Revision 1... corrects License Renewal Interim Staff Guidance, LR-ISG-2011-01, ``Aging Management of Stainless Steel Structures and Components in Treated Borated Water,'' which was announced in the Federal Register on May...

  12. Meningitis retention syndrome

    Directory of Open Access Journals (Sweden)

    Abhishek Krishna

    2012-04-01

    Full Text Available A 50-year-old Caucasian woman presented with signs and symptoms of meningitis preceded by a 3 day history of flu-like symptoms and progressive difficulty with urination. Cerebrospinal Fluid (CSF analysis was consistent with aseptic meningitis. She was found to have a significant urinary retention secondary to atonic bladder. MRI of the brain and spine were normal and CSF-PCR (polymerase chain reaction was positive for HSV-2. Urinary retention in the context of meningitis and CSF pleocytosis is known as Meningitis Retention Syndrome (MRS. MRS is a rare but important complication of meningitis most commonly associated with HSV-2. Involvement of central pathways may have a role in the pathogenesis of MRS but this is poorly documented. MRS is different from Elsberg syndrome wherein patients display features of lumbosacral polyradiculitis or radiculomyelitis. Early treatment with antiviral therapy was associated with a favorable outcome in our patient.

  13. Wood pole overhead lines

    CERN Document Server

    Wareing, Brian

    2005-01-01

    This new book concentrates on the mechanical aspects of distribution wood pole lines, including live line working, environmental influences, climate change and international standards. Other topics include statutory requirements, safety, profiling, traditional and probabilistic design, weather loads, bare and covered conductors, different types of overhead systems, conductor choice, construction and maintenance. A section has also been devoted to the topic of lightning, which is one of the major sources of faults on overhead lines. The book focuses on the effects of this problem and the strate

  14. Complexation Between Borate ion and Hydroxyl Groups of Phenol-Formaldehyde Resol Resin

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The complexation reaction between borate ions and phenol-formaldehyde resol resin in aqueous solution was studied by pH measurement, small model molecules and infrared spectroscopy.The results show that the complexation can proceed completely and rapidly at room temperature.Borate ion attacks phenol hydroxyl groups and adjacent position hydroxymethyl groups on the phenol ring of the resin, and forms the coordinate bond between boron atom in borate ion and oxygen atom in the hydroxyl groups. The complexation is a quantitative reaction. The complex is a six member ring containing two oxygens and one boron. The complexation can release hydrogen ions resulting in the decreasing pH in the resin solution.

  15. Dopant Concentration and Effective Atomic Number of Copper-Doped Potassium Borate Glasses

    Directory of Open Access Journals (Sweden)

    I. Hossain

    2013-01-01

    Full Text Available Copper-doped (0.5 mol% and undoped potassium borate glasses have been prepared by the composition of (100-xH3BO3 + xK2CO3, where 10 ≤ x ≤ 30 mol % by the traditional melting quenching method. The structural pattern of glasses with different composition has been identified by X-ray diffraction (XRD. The glow curves were analysed to determine various characterizations of the TLDs. Identification of the compositions and concentrations and effective atomic number of undoped and doped potassium borate glass was carried out using scanning electron microscope analysis (SEM. The dopant concentrations are found to be 0.25 mol%, while Zeff are 11.42 and 10.48 for Cu-doped and undoped potassium borate glasses, respectively.

  16. Esterification of Carboxylic Acids and Diacids by Trialkyl Borate under Solvent- and Catalyst-Free Conditions

    Institute of Scientific and Technical Information of China (English)

    MANSOORI Yagoub; TATAROGLU SEYIDOV Firdovsi; BOHLOOLI Shahrbanoo; ZAMANLOO Mohammad Reza; IMANZADEH Gholam Hassan

    2007-01-01

    Esterification or transesterification reactions are usually carried out in the presence of homogeneous or heterogeneous catalysts.However,recently a new method was reported for the esterification of carboxylic acids by tributyl borate under solvent- and catalyst-free conditions.In order to show the synthetic ability of trialkyl borate esters in the esterification reactions,here,the esterification of other carboxylic acids and diacids by tributyl-,triisoamyl-,and tribenzyl borate under the same conditions were reported.Some of the prepared ester and diester products have found wide applications as plasticizers and synthetic ester base lubricants.The esterification reactions have been cleanly carried out in the absence of any solvent under catalyst-free conditions.The maximum rate belongs to isoamyl trichloroacetate (Ⅵb) which reached about 76% within about 6.5 h.On the basis of obtained findings,it seems that electron withdrawing groups on carboxylic acid facilitate the esterification reaction.

  17. Rheological Properties of Konjac Glucomannan/SiO_2 /Organic-Borate Gels

    Institute of Scientific and Technical Information of China (English)

    WU Lili; ZHANG Chaocan; GUO Jinming; GAO Shanjun

    2009-01-01

    A series of thermoreversible konjac glucomannan gels crosslinked by organic bo-rate were prepared.Required amount of hydrophilic SiO_2 was added into the konjac glucomannan solutions before the crosslinking reaction.The gel network was formed through the crosslinking reac-tion between borate ions dissociated from organic borate and the cis-diol hydroxyl groups on the mannose units of polysaccharide chains.The rheological properties of the complex gels were studied by dynamic viscoelastic measurement.The gelation kinetics of the complex gels was studied and the critical gelation points of the gels were exactly determined by the Winter-Chambon criterion.The ef-fects of temperature and composite ratio on the shear storage modulus(G'),the loss modulus(G") and the sol-gel transition points were investigated.

  18. Radiation Shielding Properties Comparison of Pb-Based Silicate, Borate, and Phosphate Glass Matrices

    Directory of Open Access Journals (Sweden)

    Suwimon Ruengsri

    2014-01-01

    Full Text Available Theoretical calculations of mass attenuation coefficients, partial interactions, atomic cross-section, and effective atomic numbers of PbO-based silicate, borate, and phosphate glass systems have been investigated at 662 keV. PbO-based silicate glass has been found with the highest total mass attenuation coefficient and then phosphate and borate glasses, respectively. Compton scattering has been the dominate interaction contributed to the different total attenuation coefficients in each of the glass matrices. The silicate and phosphate glass systems are more appropriate choices as lead-based radiation shielding glass than the borate glass system. Moreover, comparison of results has shown that the glasses possess better shielding properties than standard shielding concretes, suggesting a smaller size requirement in addition to transparency in the visible region.

  19. Wood-related occupations, wood dust exposure, and sinonasal cancer.

    Science.gov (United States)

    Hayes, R B; Gerin, M; Raatgever, J W; de Bruyn, A

    1986-10-01

    A case-control study was conducted to examine the relations between type of woodworking and the extent of wood dust exposure to the risks for specific histologic types of sinonasal cancer. In cooperation with the major treatment centers in the Netherlands, 116 male patients newly diagnosed between 1978 and 1981 with primary malignancies of epithelial origin of this site were identified for study. Living controls were selected from the municipal registries, and deceased controls were selected from the national death registry. Interviews were completed for 91 (78%) cases and 195 (75%) controls. Job histories were coded by industry and occupation. An index of exposure was developed to classify the extent of occupational exposure to wood dust. When necessary, adjustment was made for age and usual cigarette use. The risk for nasal adenocarcinoma was elevated by industry for the wood and paper industry (odds ratio (OR) = 11.9) and by occupation for those employed in furniture and cabinet making (OR = 139.8), in factory joinery and carpentry work (OR = 16.3), and in association with high-level wood dust exposure (OR = 26.3). Other types of nasal cancer were not found to be associated with wood-related industries or occupations. A moderate excess in risk for squamous cell cancer (OR = 2.5) was associated with low-level wood dust exposure; however, no dose-response relation was evident. The association between wood dust and adenocarcinoma was strongest for those employed in wood dust-related occupations between 1930 and 1941. The risk of adenocarcinoma did not appear to decrease for at least 15 years after termination of exposure to wood dust. No cases of nasal adenocarcinoma were observed in men whose first exposure to wood dust occurred after 1941.

  20. Luminescence properties of the Sm-doped borate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Kindrat, I.I. [University of Zielona Góra, Institute of Physics, Division of Spectroscopy of Functional Materials, 4a Szafrana Street, 65-516 Zielona Góra (Poland); Padlyak, B.V., E-mail: B.Padlyak@if.uz.zgora.pl [University of Zielona Góra, Institute of Physics, Division of Spectroscopy of Functional Materials, 4a Szafrana Street, 65-516 Zielona Góra (Poland); Vlokh Institute of Physical Optics, 23 Dragomanov Street, 79-005 Lviv (Ukraine); Drzewiecki, A. [University of Zielona Góra, Institute of Physics, Division of Spectroscopy of Functional Materials, 4a Szafrana Street, 65-516 Zielona Góra (Poland)

    2015-10-15

    The optical absorption and photoluminescence (emission and excitation) spectra as well as decay kinetics of a series of the Sm-doped glasses with Li{sub 2}B{sub 4}O{sub 7}, LiKB{sub 4}O{sub 7}, CaB{sub 4}O{sub 7}, and LiCaBO{sub 3} compositions were investigated and analysed. The Li{sub 2}B{sub 4}O{sub 7}:Sm, LiKB{sub 4}O{sub 7}:Sm, CaB{sub 4}O{sub 7}:Sm, and LiCaBO{sub 3}:Sm glasses of high optical quality have been obtained from the corresponding polycrystalline compounds in the air atmosphere, using a standard glass technology. On the basis of electron paramagnetic resonance (EPR) and optical spectra analysis it was shown that the samarium impurity is incorporated into the glass network as Sm{sup 3+} (4f{sup 5}, {sup 6}H{sub 5/2}) ions, exclusively. All observed 4f – 4f transitions of the Sm{sup 3+} centres in the optical absorption and luminescence spectra of the investigated glasses are identified. Most intense emission band of the Sm{sup 3+} ions peaked about 598 nm ({sup 4}G{sub 5/2} → {sup 6}H{sub 7/2} transition) is characterised by a single exponential decay with typical lifetime values, which depend on the basic glass composition as well as concentration and local structure of the Sm{sup 3+} luminescence centres. The quantum efficiency has been evaluated for observed transitions of the Sm{sup 3+} centres using obtained experimental lifetimes and radiative lifetimes calculated by Judd–Ofelt theory. The calculated high quantum efficiencies and measured quantum yields of luminescence show that the investigated borate glasses are perspective luminescence materials. Energy transfer from the Ce{sup 3+} non-controlled impurity and intrinsic luminescence centres to the Sm{sup 3+} centres has been observed. Peculiarities of the Sm{sup 3+} local structure in the network of investigated glasses have been discussed based on the obtained spectroscopic results and structural data. - Highlights: • The Sm-doped Li{sub 2}B{sub 4}O{sub 7}, LiKB{sub 4}O{sub 7}, Ca

  1. Chemical and boron isotopic compositions of tourmaline from the Paleoproterozoic Houxianyu borate deposit, NE China: Implications for the origin of borate deposit

    Science.gov (United States)

    Yan, Xue-long; Chen, Bin

    2014-11-01

    The Houxianyu borate deposit in northeastern China is one of the largest boron sources of China, hosted mainly in the Paleoproterozoic meta-volcanic and sedimentary rocks (known as the Liaohe Group) that are characterized by high boron concentrations. The borate ore-body has intimate spatial relationship with the Mg-rich carbonates/silicates of the Group, with fine-grained gneisses (meta-felsic volcanic rocks) as main country rocks. The presence of abundant tourmalinites and tourmaline-rich quartz veins in the borate orebody provides an opportunity to study the origin of boron, the nature of ore-forming fluids, and possible mineralization mechanism. We report the chemical and boron isotopic compositions of tourmalines from the tourmaline-rich rocks in the borate deposit and from the tourmaline-bearing fine-grained gneisses. Tourmalines from the fine-grained gneisses are chemically homogeneous, showing relatively high Fe and Na and low Mg, with δ11B values in a narrow range from +1.22‰ to +2.63‰. Tourmalines from the tourmaline-rich rocks, however, commonly show compositional zoning, with an irregular detrital core and a euhedral overgrowth, and have significantly higher Mg, REE (and more pronounced positive Eu anomalies), V (229-1852 ppm) and Sr (208-1191 ppm) than those from the fine-grained gneisses. They show varied B isotope values ranging from +4.51‰ to +12.43‰, which plot intermediate between those of the terrigenous sediments and arc rocks with low boron isotope values (as represented by the δ11B = +1.22‰ to +2.63‰ of the fine-grained gneisses of this study) and those of marine carbonates and evaporates with high boron isotope values. In addition, the rim of the zoned tourmaline shows notably higher Mg, Ti, V, Sn, and Pb, and REE (particularly LREEs), but lower Fe, Co, Cr, Ni, Zn, Mn, and lower δ11B values than the core. These data suggest that (1) the sources of boron of the borate ore-body are mainly the Paleoproterozoic meta-volcanic and

  2. IMPROVEMENT OF INTERNATIONAL WOOD TRANSPORTATION

    Directory of Open Access Journals (Sweden)

    Sokolov A. P.

    2014-10-01

    Full Text Available The article gives an example of usage of the tool for round-wood transport planning from the Decision Support System “Forest Logistic Toolset” for com-pare of two approaches to the organization of international wood transportation

  3. Preservation of forest wood chips

    Energy Technology Data Exchange (ETDEWEB)

    Kofman, P.D.; Thomsen, I.M.; Ohlsson, C.; Leer, E.; Ravn Schmidt, E.; Soerensen, M.; Knudsen, P.

    1999-01-01

    As part of the Danish Energy Research Programme on biomass utilisation for energy production (EFP), this project concerns problems connected to the handling and storing of wood chips. In this project, the possibility of preserving wood chips of the Norway Spruce (Picea Abies) is addressed, and the potential improvements by anaerobic storage are tested. Preservation of wood chips aims at reducing dry matter losses from extensive heating during storage and to reduce production of fungal spores. Fungal spores pose a health hazards to workers handling the chips. Further the producers of wood chips are interested in such a method since it would enable them to give a guarantee for the delivery of homogeneous wood chips also during the winter period. Three different types of wood chips were stored airtight and further one of these was stored in accordance with normal practise and use as reference. The results showed that airtight storage had a beneficial impact on the quality of the chips: no redistribution of moisture, low dry matter losses, unfavourable conditions for microbial activity of most fungi, and the promotion of yeasts instead of fungi with airborne spores. Likewise the firing tests showed that no combustion problems, and no increased risk to the environment or to the health of staff is caused by anaerobic storage of wood chips. In all, the tests of the anaerobic storage method of forest wood chips were a success and a large-scale test of the method will be carried out in 1999. (au)

  4. Wood gas; Holz gibt Gas

    Energy Technology Data Exchange (ETDEWEB)

    Hilgers, Claudia

    2011-06-17

    Sixty years ago, wood gas was even used as a car fuel. Today, this ancient technology is experiencing a renaissance. Small cogeneration plants with wood gasifiers are ideal for renewable and decentral power supply concepts for tomorrow. Until then, there is much pioneering work to do until plants will be ready for serial production.

  5. Moisture transport in coated wood

    NARCIS (Netherlands)

    Meel, P.A. van; Erich, S.J.F.; Huinink, H.P.; Kopinga, K.; Jong, J. DE; Adan, O.C.G.

    2011-01-01

    Moisture accumulation inside wood causes favorable conditions for decay. Application of a coating alters the moisture sorption of wood and prevents accumulation of moisture. This paper presents the results of a nuclear magnetic resonance (NMR) study on the influence of a coating on the moisture abso

  6. Design Wood Nanocomposites from Polymer Nanocomposites

    Institute of Scientific and Technical Information of China (English)

    LVWenhua; ZHAOGuangjie

    2004-01-01

    Researches on wood nanocomposites, which involve nano science and technology, wood science,materials science and other related subjects, have important science signification and promising prospect for the development and study of new wood composites with high appending values and multi-properties. This paper reviewed the conventional wood composites, and then discussed the approaches to prepare wood nanocomposites. Based on the achievements of researches on polymer/montmorillonite (MMT) nanocomposites, the design ideas of preparing nanocomposites of wood and inorganic MMT were systematically put forward. Nano compounding of wood and other materials is an effective approach to greatly improve or modify wood.

  7. Structural and acoustical studies of lead sodium borate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Saddeek, Yasser B. [Physics Department, Faculty of Science, Al-Azhar University, Assiut P.O. 71452 (Egypt)], E-mail: ysaddeek@gmail.com

    2009-01-07

    Glasses in the system Na{sub 2-2x}B{sub 4-4x}Pb{sub x}O{sub 7-6x}, 0 {<=} x {<=} 0.8, have been prepared by the melt quenching technique. Elastic properties and Debye temperature have been investigated using sound velocity measurements at 4 MHz. The ultrasonic parameters along with the IR spectroscopic studies have been employed to study the role of PbO on the structure of Na{sub 2}B{sub 4}O{sub 7} glass. The density, the molar volume, and the ultrasonic parameters of these samples have been found to be compositional dependent. The results indicate that PbO acts as a network modifier in the range 0 {<=} x {<=} 0.4, while beyound x = 0.4, PbO acts as a network former which affects the diborate units that mainly consist the strong borate network. These results are interpreted in terms of the IR analysis that indicates the transformation of the structural units BO{sub 3} into BO{sub 4}, the increase in the number of non-bridging oxygen atoms, and the substitution of longer Pb-O bond length, in place of shorter B-O bond. The observed compositional dependence of the elastic moduli is interpreted in terms of the effect of PbO on the boron-coordination number of the glass structure and to the relatively large electron-phonon anharmonic interactions. A good correlation was observed between the experimentally determined elastic moduli and those computed according to Makishima-Mackenzie model.

  8. Structural and optical properties of niobium doped silver-lead-borate glasses

    Science.gov (United States)

    Sathish, M.; Eraiah, B.

    2013-06-01

    Nb2O5 doped silver lead borate glasses with the chemical composition (29—x)PbO-1Ag2O-70B2O3-xNb2O5 (where x=0.1mol % and 0.5 mol %) have prepared by conventional melt quenching method. FTIR and UV absorption technique have been used in order to obtain the information concerning network structure. As Nb2O5 concentration increased, the borate glass network is shown to change three coordinated to four coordinated boron system. SEM technique confines glassy nature of the prepared samples. The calculated optical band gap increases with increase Nb2O5 concentration.

  9. Study of the microstructural transformations of borate glass and barium metaborate crystals induced by femtosecond laser

    Institute of Scientific and Technical Information of China (English)

    Chen Bin; Yu Bing-Kun; Yan Xiao-Na; Qiu Jian-Rong; Jiang Xiong-Wei; Zhu Cong-Shan

    2004-01-01

    This paper describes the microstructural transformations of borate glass and barium metaborate crystals induced by femtosecond laser. Such structural transformations were verified by Raman spectroscopy. The borate glass is transformed into low temperature (LT) phase of barium metaborate (BaB2O4) crystals after being irradiated for 10 min by a femtosecond laser. In addition, after 20 min of irradiation, high temperature (HT) phase of BaB2O4 crystals is also produced. Further studies demonstrate that LT phase BaB2O4 crystals are formed in the HT phase BaB2O4 crystals after femtosecond laser irradiation for 10 s.

  10. General and Localized corrosion of Austenitic and Borated Stainless Steels in Simulated Concentrated Ground Waters

    Energy Technology Data Exchange (ETDEWEB)

    D. Fix; J. Estill; L. Wong; R. Rebak

    2004-05-28

    Boron containing stainless steels are used in the nuclear industry for applications such as spent fuel storage, control rods and shielding. It was of interest to compare the corrosion resistance of three borated stainless steels with standard austenitic alloy materials such as type 304 and 316 stainless steels. Tests were conducted in three simulated concentrated ground waters at 90 C. Results show that the borated stainless were less resistant to corrosion than the witness austenitic materials. An acidic concentrated ground water was more aggressive than an alkaline concentrated ground water.

  11. General and Localized Corrosion of Austenitic And Borated Stainless Steels in Simulated Concentrated Ground Waters

    Energy Technology Data Exchange (ETDEWEB)

    Estill, J C; Rebak, R B; Fix, D V; Wong, L L

    2004-03-11

    Boron containing stainless steels are used in the nuclear industry for applications such as spent fuel storage, control rods and shielding. It was of interest to compare the corrosion resistance of three borated stainless steels with standard austenitic alloy materials such as type 304 and 316 stainless steels. Tests were conducted in three simulated concentrated ground waters at 90 C. Results show that the borated stainless were less resistant to corrosion than the witness austenitic materials. An acidic concentrated ground water was more aggressive than an alkaline concentrated ground water.

  12. Evaluation of borated aluminum products for criticality control in 235-F

    Energy Technology Data Exchange (ETDEWEB)

    Crouch, W. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2003-04-01

    Plutonium-containing materials are destined for storage in the 235-F vault. The projected amount of stored materials will require the presence of neutron absorber materials. The leading design concept is for the neutron absorber materials to be in non-load-bearing borated aluminum plates lining the walls of the vault. A comprehensive evaluation of the borated aluminum plate materials was performed to identify a suitable material, and verify that these materials would remain effective as neutron absorbers under normal service conditions and for design-basis events, including the fire accident scenario, throughout a 20-year service life. Aluminum 1100 with boron additions is the recommended neutron absorber material for plutonium material storage in the 235-F vault based on boron loading capacity and durability in the storage environment. Borated aluminum 1100 is commercially available up to 4.5 wt. % boron. A detailed comparison was made of the physical, mechanical, and corrosion properties of borated aluminum alloy 1100 to standard alloy 1100-O1 to demonstrate near-equivalency in properties and to justify application of alloy 1100-O properties to the borated product as needed for the degradation analysis. The expected degradation of the borated aluminum is extremely low for storage conditions, including the bounding scenario of an aggressive atmospheric condition. A maximum loss of 0.00029 inches/year would be expected under potentially aggressive atmospheric conditions and would result in a fractional loss of only 0.42 wt. % of the boron present in a 7mm plate for a 20-year storage period. The fraction of Boron-10 consumption by spontaneous neutrons is expected to be less than 10-8 for the 20-year storage in 235-F fully loaded with Pu materials. The borated aluminum alloy 1100 will be thermally stable and unaltered up to near-melt temperature (643°C). Mechanical testing data at elevated temperatures show that the strengths (yield and ultimate) of the borated

  13. Evaluation of borated aluminum products for criticality control in 235-F

    Energy Technology Data Exchange (ETDEWEB)

    Duncan, A. [Savannah River Site (SRS), Aiken, SC (United States); Sindelar, R. [Savannah River Site (SRS), Aiken, SC (United States)

    2003-05-06

    Plutonium-containing materials are destined for storage in the 235-F vault. The projected amount of stored materials will require the presence of neutron absorber materials. The leading design concept is for the neutron absorber materials to be in non-load-bearing borated aluminum plates lining the walls of the vault. A comprehensive evaluation of the borated aluminum plate materials was performed to identify a suitable material, and verify that these materials would remain effective as neutron absorbers under normal service conditions and for design-basis events, including the fire accident scenario, throughout a 20-year service life. Aluminum 1100 with boron additions is the recommended neutron absorber material for plutonium material storage in the 235-F vault based on boron loading capacity and durability in the storage environment. Borated aluminum 1100 is commercially available up to 4.5 wt. % boron. A detailed comparison was made of the physical, mechanical, and corrosion properties of borated aluminum alloy 1100 to standard alloy 1100-O (-O designating the fully annealed condition) to demonstrate near-equivalency in properties and to justify application of alloy 1100-O properties to the borated product as needed for the degradation analysis. The expected degradation of the borated aluminum is extremely low for storage conditions, including the bounding scenario of an aggressive atmospheric condition. A maximum loss of 0.00029 inches/year would be expected under potentially aggressive atmospheric conditions and would result in a fractional loss of only 0.42 wt.% of the boron present in a 7mm plate for a 20-year storage period. The fraction of Boron-10 consumption by spontaneous neutrons is expected to be less than 10{sup -8} for the 20-year storage in 235-F fully loaded with Pu materials. The borated aluminum alloy 1100 will be thermally stable and unaltered up to near-melt temperature (643°C). Mechanical testing data at elevated temperatures show that the

  14. Removal of borate by coprecipitation with Mg/Al layered double hydroxide

    Science.gov (United States)

    Kurashina, Masashi; Inoue, Tatsuki; Tajima, Chihiro; Kanezaki, Eiji

    2015-03-01

    Borate has been used for various industrial products and excessive dose of boron is harmful to humans. We investigated the removal of borate by direct coprecipitation with Mg/Al layered double hydroxide. In this study, the maximum removal of boron was 90% when Mg 30 mmol and Al 15 mmol at pH = 10 were used for 498 mg/l as B. The boron adsorption isotherms could be fitted to Langmuir model. The calculated constant Ws, saturation limit of boron adsorption, is 25 ± 2 mg/g and it is larger than that of ion exchange reaction (Ws = 15±1 mg/g).

  15. THE COMBUSTION PROPERTIES OF LAMINATED WOOD MATERIALS PREPARED FROM SCOTCH PINE (Pinus sylvestris L.

    Directory of Open Access Journals (Sweden)

    Ramazan ÖZEN

    2001-01-01

    Full Text Available In this study, the combustion properties of 3 ply laminated wood material, which was produced from scotch pine (Pinus sylvestris L. impregnated with Sodium perborat, Sodium tetra borat, Imersol (I-WR 2000 and TanalithCBC (T-CBC by using dipping method has been investigated. Prepared materials have been bonded with Desmodur- VTKA adhesive and tested according to the procedure of ASTM-E 69 standards. As a result, the highest weight loss (60.83 g in laminated sample impregnated with I-WR 2000, CO rate (6340.85 ppm in neutral sample impregnated with T-CBC, CO2 rate (7.48 %, O2 rate (13.03 % and according to the first weight rate the highest combustion rate (82.73 % in control samples, heat increasing (406.55 o C in laminated sample impregnated with T-CBC have been obtained. According to these results, in the combustion tests of laminated samples sodium tetra borat and sodium perborat have been determined as a successful fire retardant chemical.

  16. [Biological effect of wood dust].

    Science.gov (United States)

    Maciejewska, A; Wojtczak, J; Bielichowska-Cybula, G; Domańska, A; Dutkiewicz, J; Mołocznik, A

    1993-01-01

    The biological effect of exposure to wood dust depends on its composition and the content of microorganisms which are an inherent element of the dust. The irritant and allergic effects of wood dust have been recognised for a long time. The allergic effect is caused by the wood dust of subtropical trees, e.g. western red cedar (Thuja plicata), redwood (Sequoia sempervirens), obeche (Triplochiton scleroxylon), cocabolla (Dalbergia retusa) and others. Trees growing in the European climate such as: larch (Larix), walnut (Juglans regia), oak (Quercus), beech (Fagus), pine (Pinus) cause a little less pronounced allergic effect. Occupational exposure to irritative or allergic wood dust may lead to bronchial asthma, rhinitis, alveolitis allergica, DDTS (Organic dust toxic syndrome), bronchitis, allergic dermatitis, conjunctivitis. An increased risk of adenocarcinoma of the sinonasal cavity is an important and serious problem associated with occupational exposure to wood dust. Adenocarcinoma constitutes about half of the total number of cancers induced by wood dust. An increased incidence of the squamous cell cancers can also be observed. The highest risk of cancer applies to workers of the furniture industry, particularly those dealing with machine wood processing, cabinet making and carpentry. The cancer of the upper respiratory tract develops after exposure to many kinds of wood dust. However, the wood dust of oak and beech seems to be most carcinogenic. It is assumed that exposure to wood dust can cause an increased incidence of other cancers, especially lung cancer and Hodgkin's disease. The adverse effects of microorganisms, mainly mould fungi and their metabolic products are manifested by alveolitis allergica and ODTS. These microorganisms can induce aspergillomycosis, bronchial asthma, rhinitis and allergic dermatitis.

  17. Neutron scattering in concrete and wood: Part II--Oblique incidence.

    Science.gov (United States)

    Facure, A; Silva, A X; Rivera, J C; Falcão, R C

    2008-01-01

    The knowledge of neutron reflection coefficients is of practical interest when projecting the shielding of radiotherapy rooms, since it is known that about 75% of the neutrons at the maze entrance of these rooms are scattered neutrons. In a previous paper, the energy spectra of photoneutrons were calculated, when reflected by ordinary, high-density concrete and wood barriers, using the MCNP5 code, considering normal incidence and neutron incident energies varying between 0.1 and 10 MeV. It was found that the mean energy of the reflected neutrons does not depend on the reflection angle and that these mean energies are lower in wood and barytes concrete, compared with ordinary concrete. In the present work, the simulation of neutron reflection coefficients were completed, considering the case when these particles do not collide frontally with the barriers, which constitute the radiotherapy room walls. Some simulations were also made to evaluate how neutron equivalent doses at the position of the room door is affected when the maze walls are lined with neutron absorbing materials, such as wood itself or borated polyethylene. Finally, capture gamma rays dose at the entrance of rooms with different maze lengths were also simulated. The results were discussed in the light of the albedo concepts presented in the literature and some of these results were confronted with others, finding good agreement between them.

  18. EFFECT OF FIRE RETARDANTS ON SURFACE ROUGHNESS AND WETTABILITY OF WOOD PLASTIC COMPOSITE PANELS

    Directory of Open Access Journals (Sweden)

    Nadir Ayrilmis

    2011-06-01

    Full Text Available Surface roughness and wettability of flat-pressed wood plastic composites (WPCs incorporated with various fire retardants (FRs (5, 10, or 15% by weight (wt at 50 wt-% content of the wood flour (WF were investigated. The most common FRs, zinc borate (ZB, magnesium hydroxide (MH, and ammonium polyphosphate (APP, were used in the experiments. The WPC panels were made from dry-blended wood flour (WF, fire retardant (FR powder, and polypropylene (PP powder with maleic anhydride-grafted PP (2 wt-% formulations using a conventional flat-pressing process under laboratory conditions. The contact angle measurements were obtained by using a goniometer connected with a digital camera and computer system. Three roughness measurements, average roughness (Ra, mean peak-to-valley height (Rz, and maximum roughness (Ry, were taken from the WPC panel surface using a fine stylus tracing technique. It was found that the surface smoothness of the WPC panels decreased with increasing content of the FR powder while the wettability increased. The control WPC panel without the FR had the smoothest surface, followed by the WPC panels containing the MH, ZB, and APP, respectively.

  19. Utilizing wood wastes as reinforcement in wood cement composite bricks

    Directory of Open Access Journals (Sweden)

    Nusirat Aderinsola Sadiku

    2015-07-01

    Full Text Available This paper presents the research work undertaken to study the properties of Wood Cement Composite Bricks (WCCB from different wood wastes and cement / wood content. The WCBBs with nominal density of 1200 kg m-3 were produced from three tropical wood species and at varying cement and wood content of 2:1, 2.5:1 and 3:1 on a weight to weight basis. The properties evaluated were compressive strength, Ultra Pulse Velocity (UPV, water absorption (WA and thickness swelling (TS. The Compressive strength values ranged from 0.25 to 1.13 N mm-2 and UPV values ranged from 18753 to 49992 m s-1. The mean values of WA after 672 hours (28 days of water soaking of the WCCBs ranged from 9.50% to 47.13% where there were no noticeable change in the TS of the bricks. The observed density (OD ranged from 627 to 1159 kg m-3. A. zygia from the three wood/cement content were more dimensionally stable and better in compressive strength than the other two species where T. scleroxylon had the best performance in terms of UPV. All the properties improved with increasing cement content. WCCBs at 3.0:1 cement/wood content are suitable for structural application such as panelling, ceiling and partitioning

  20. Eco-friendly wood-based solid-state flexible supercapacitors from wood transverse section slice and reduced graphene oxide

    Science.gov (United States)

    Lv, Shaoyi; Fu, Feng; Wang, Siqun; Huang, Jingda; Hu, La

    2015-07-01

    An interesting wood-based all-solid-state supercapacitor is produced using reduced graphene oxide (RGO) coated on wood transverse section slice (WTSS) as electrode material by means of a low-cost, eco-friendly, and simple method for the first time. The RGO-coated WTSS electrode has a porous 3D honeycomb framework due to the hierarchical cellular structure of the WTSS substrate and can function as an electrolyte reservoir. This special construction endows this novel electrode with good areal capacitance (102 mF cm-2) and excellent cyclic stability (capacitance retention of 98.9% after 5000 cycles). In addition, the supercapacitors exhibit good mechanical flexibility and preserve almost constant capacitive behavior under different bending conditions. Our study introduces a new and eco-friendly material design for electrodes in future flexible energy storage devices that closely resemble natural materials. [Figure not available: see fulltext.

  1. phosphorus retention data and metadata

    Data.gov (United States)

    U.S. Environmental Protection Agency — phosphorus retention in wetlands data and metadata. This dataset is associated with the following publication: Lane , C., and B. Autrey. Phosphorus retention of...

  2. General Reviews of Vocabulary Retention

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yuan

    2013-01-01

    This paper will try to review two important theories (repletion and retrieval) which are crucial for vocabulary retention. These two methods are well connected and each of them cannot lead to successful vocabulary retention without sensible utilization of the other.

  3. Effect of Durability Treatment on Moisture Sorption Properties of Wood-Plastic Composites

    Directory of Open Access Journals (Sweden)

    Huiyuan Li

    2014-09-01

    Full Text Available In this study, water absorption and desorption behaviors of wood-plastic composites (WPCs treated with ultraviolet agents and zinc borate were investigated. Water diffusion characteristics in the composites were analyzed using a one-dimensional diffusion model. The mechanism of water sorption for all composites deviated from Fick’s law of diffusion. Much larger diffusion coefficient values are observed from the desorption process when compared to the absorption process. Measured final equilibrium moisture content and calculated diffusion coefficients varied with sample formulation in a non-consistent manner; this indicated that the durability treatment used in the current study did not negatively affect the water sorption behavior of WPCs. The results of this study help to clarify the effect of durability treatment on the dynamic moisture sorption process of WPCs.

  4. Experimental analysis and simulation modeling of forest management impacts on wood thrushes, Hylocichla mustelina

    Science.gov (United States)

    Banks, R.C.

    1998-01-01

    growth rates, reproductive success, and the effect of habitat changes on wood thrush populations. The simplest source/sink population model suggests that the Piedmont National Wildlife Refuge's wood thrush population is probably stable or increasing, and wood thrush populations in treated areas had higher growth rates than birds in untreated areas. We were able to use the individual-based model of wood thrush productivity to predict fecundity, a parameter that we could not measure directly in the field. Again, females on treated areas had higher fecundity than birds on untreated areas. Our spatially-based model predicted that wood thrush populations should respond positively to predicted changes in the age/size class structure of the Refuge's pine forests. Our model also showed that most wood thrushes leave the Refuge's forest compartments during the breeding season, and these dispersal movements are extremely important to understanding and managing wood thrush populations. The use of prescribed burning and retention shelterwood silviculture at the Piedmont National Wildlife Refuge does not appear to negatively affect the local wood thrush population. Continued use of the current management regime should result in adequate nesting, foraging, and escape habitats for wood thrushes. However, landscape-level habitat availability and quality, including lands outside the Refuge, must be considered when making management decisions that may affect wood thrushes.

  5. Cooling of wood briquettes

    Directory of Open Access Journals (Sweden)

    Adžić Miroljub M.

    2013-01-01

    Full Text Available This paper is concerned with the experimental research of surface temperature of wood briquettes during cooling phase along the cooling line. The cooling phase is an important part of the briquette production technology. It should be performed with care, otherwise the quality of briquettes could deteriorate and possible changes of combustion characteristics of briquettes could happen. The briquette surface temperature was measured with an IR camera and a surface temperature probe at 42 sections. It was found that the temperature of briquette surface dropped from 68 to 34°C after 7 minutes spent at the cooling line. The temperature at the center of briquette, during the 6 hour storage, decreased to 38°C.

  6. Non_standard Wood

    DEFF Research Database (Denmark)

    Tamke, Martin

    Non-Standard elements in architecture bear the promise of a better more specific performance (Oosterhuis 2003). A new understanding of design evolves, which is focusing on open ended approaches, able to negotiate between shifting requirements and to integrate knowledge on process and material......- and machine industry we fabricated a 1:1 demonstrator show casing the potential for performance due to digital fabrication in this sustainable material. The production of a custom made design tool helped not only to explore design variations while keeping up the link to digital production machinery....... Using parametric design tools and computer controlled production facilities Copenhagens Centre for IT and Architecture undertook a practice based research into performance based non-standard element design and mass customization techniques. In close cooperation with wood construction software...

  7. Enhancing retention of partial dentures using elastomeric retention rings

    Directory of Open Access Journals (Sweden)

    Kakkirala Revathi

    2015-01-01

    Full Text Available This report presents an alternative method for the retention of partial dentures that relies on the engagement of tooth undercuts by a lining material. The lab procedures are also presented. A new maxillary and mandibular acrylic partial dentures were fabricated using elastomeric retention technique for a partially dentate patient. A partially dentate man reported difficulty in retaining his upper removable partial denture (RPD. The maxillary RPD was designed utilizing elastomeric retention technique. During follow-up, it was necessary to replace the retention rings due to wear. The replacement of the retention rings, in this case, was done through a chairside reline technique. Elastomeric retention technique provides exceptionally good retention can be indicated to stabilize, cushion, splint periodontally involved teeth, no enough undercut for clasps, eliminate extractions, single or isolated teeth.

  8. Ground Wood Fiber Length Distributions

    Directory of Open Access Journals (Sweden)

    Lauri Ilmari Salminen

    2014-01-01

    Full Text Available This study considers ground wood fiber length distributions arising from pilot grindings. The empirical fiber length distributions appear to be independent of wood fiber length as well as feeding velocity. In terms of mathematics the fiber fragment distributions of ground wood pulp combine an exponential distribution for high-length fragments and a power-law distribution for smaller lengths. This implies that the fiber length distribution is influenced by the stone surface. A fragmentation-based model is presented that allows reproduction of the empirical results.

  9. A CONTINUING REVERENCE FOR WOOD

    Directory of Open Access Journals (Sweden)

    Martin A. Hubbe

    2010-02-01

    Full Text Available Our ancestors knew a great deal about wood. They had to in order to do well in life. Wood has played a dominant role in human infrastructure for many generations, and for most of that time woodcraft has depended on the decentralized knowledge passed down among families and guilds. This editorial, while celebrating the knowledge, skills, and insights of the woodworkers of past generations, also calls for a renewed attention to wood’s unique character, including characteristics that today are too often classified as “defects.” We may need to take lessons from generations past to truly derive the best value from wood resources.

  10. FIRE INSURANCE AND WOOD SCHOOL BUILDINGS.

    Science.gov (United States)

    PURCELL, FRANK X.

    A COMPARISON OF FIRE INSURANCE COSTS OF WOOD, MASONRY, STEEL AND CONCRETE STRUCTURES SHOWS FIRE INSURANCE PREMIMUMS ON WOOD STRUCTURES TEND TO BE HIGHER THAN PREMIUMS ON MASONRY, STEEL AND CONCRETE BUILDINGS, HOWEVER, THE INITIAL COST OF THE WOOD BUILDINGS IS LOWER. DATA SHOW THAT THE SAVINGS ACHIEVED IN THE INITIAL COST OF WOOD STRUCTURES OFFSET…

  11. Wood Technology: Techniques, Processes, and Products

    Science.gov (United States)

    Oatman, Olan

    1975-01-01

    Seven areas of wood technology illustrates applicable techniques, processes, and products for an industrial arts woodworking curriculum. They are: wood lamination; PEG (polyethylene glycol) diffusion processes; wood flour and/or particle molding; production product of industry; WPC (wood-plastic-composition) process; residential construction; and…

  12. Fire Safety Design of Wood Structures

    DEFF Research Database (Denmark)

    Hertz, Kristian Dahl

    2006-01-01

    Lecture Notes on Fire Safety Design of Wood Structures including charring of wood and load bearing capacity of beams, columns, and connections.......Lecture Notes on Fire Safety Design of Wood Structures including charring of wood and load bearing capacity of beams, columns, and connections....

  13. Geochemical characteristics of Kırka (Sarıkaya) borate deposit, northwestern Anatolia, Turkey

    Indian Academy of Sciences (India)

    İ Koçak; Ş Koç

    2016-02-01

    The Kırka borate deposit was deposited in a Miocene lacustrine basin which is closely associated with volcanic activity which lasted from Paleogene to the beginning of Quaternary. Borate mineralization alternates with claystone, mudstone, tuff and fine-layered limestone and mostly shows a lenticular structure. The mineral paragenesis is composed of borax, tincalconite, ulexite, kurnakovite, probertite, tunellite, colemanite, dolomite, smectite group minerals, illite and some firstly reported minerals for the Kırka deposit including hydrochloroborite, brianroulstonite, hilgardite-4M and searlesite minerals. In comparison to average values of earth crust, concentrations of Cs, Sr, Li, As and Se were significantly enriched with respective rates of 21, 15, 14, 3 and 188 folds. Regarding KY, KS1 and KS2 locations, there are differences in both element abundances and their geochemical tendencies which are attributed to variations in discharge regime and physico-chemical conditions of the depositional environment. Independent behaviour of B2O3 might indicate that boron is not associated with clays and carbonates and, therefore, most part of boron must be derived from volcanic activity (hydrothermal solutions, gases). REE data indicate that the Kırka borate deposit was formed in a sedimentary environment where highly alkaline (high pH) hydrothermal solutions also took part in borate precipitation process.

  14. STRUCTURE AND DYNAMICS OF ALKALI BORATE GLASSES - A MOLECULAR-DYNAMICS STUDY

    NARCIS (Netherlands)

    VERHOEF, AH; DENHARTOG, HW

    1995-01-01

    Structural and dynamical properties of lithium, cesium and mixed alkali (i.e., lithium and cesium) borate glasses have been studied by the molecular dynamics method. The calculations yield glass structures consisting of planar BO3 triangles and BO4 tetrahedrons with no sixfold ring structures at all

  15. Characterization and Neutron Shielding Behavior of Dehydrated Magnesium Borate Minerals Synthesized via Solid-State Method

    Directory of Open Access Journals (Sweden)

    Azmi Seyhun Kipcak

    2013-01-01

    Full Text Available Magnesium borates are one of the major groups of boron minerals that have good neutron shielding performance. In this study, dehydrated magnesium borates were synthesized by solid-state method using magnesium oxide (MgO and boron oxide (B2O3, in order to test their ability of neutron shielding. After synthesizing the dehydrated magnesium borates, characterizations were done by X-ray Diffraction (XRD, fourier transform infrared (FT-IR, Raman spectroscopy, and scanning electron microscopy (SEM. Also boron oxide (B2O3 contents and reaction yields (% were calculated. XRD results showed that seven different types of dehydrated magnesium borates were synthesized. 1000°C reaction temperature, 240 minutes of reaction time, and 3 : 2, 1 : 1 mole ratios of products were selected and tested for neutron transmission. Also reaction yields were calculated between 84 and 88% for the 3 : 2 mole ratio products. The neutron transmission experiments revealed that the 3 : 2 mole ratio of MgO to B2O3 neutron transmission results (0.618–0.655 was better than the ratio of 1 : 1 (0.772–0.843.

  16. Synthesis and study on the luminescence properties of cadmium borate phosphors

    Energy Technology Data Exchange (ETDEWEB)

    Annalakshmi, O. [Radiological Safety Division, Indira Gandhi Center for Atomic Research, Kalpakkam 603102, Tamilnadu (India); Jose, M.T., E-mail: mtjosein@yahoo.co.in [Radiological Safety Division, Indira Gandhi Center for Atomic Research, Kalpakkam 603102, Tamilnadu (India); Venkatraman, B. [Radiological Safety Division, Indira Gandhi Center for Atomic Research, Kalpakkam 603102, Tamilnadu (India); Amarendra, G. [Materials Physics Division, Indira Gandhi Center for Atomic Research, Kalpakkam 603102, Tamilnadu (India)

    2014-02-01

    Highlights: • Cadmium borate synthesized by solid state sintering technique. • Neutron sensitivity of the material ten times that of TLD-600. • Gamma sensitivity is found to be twice that of TLD-100. • Gamma response is linear from 0.1 to 10{sup 3} mGy. - Abstract: Cadmium borate compound prepared through wet chemical reaction from the starting chemicals followed by high temperature solid state synthesis below the melting point to get the final TL phosphor powder. Phase purity and bond details of cadmium borate crystals are characterized using X-ray diffraction technique and infrared spectroscopy. Feasibility of these materials for radiation dosimetry applications was studied after gamma and neutron irradiation. Gamma irradiation of undoped phosphors show a single peak around 185 °C whereas doping with gadolinium and silver, new more intense peak observed at 290 °C. Irradiation to thermal neutrons revealed single peak around 170 °C for all the phosphors. TL emission spectra and photoluminescence (PL) studies were also carried out on the phosphors. These borate materials are found to be highly sensitive to neutrons and hence can be used for neutron detection. Neutron sensitivity of the material is about ten times that of TLD-600.

  17. Crystallization of Reduced Strontium and Barium Niobate Perovskites from Borate Fluxes.

    NARCIS (Netherlands)

    Hessen, B.; Sunshine, S.A.; Siegrist, T.; Jimenez, R.

    1991-01-01

    Single crystals of three AxNbO3 (A = Sr, Ba) reduced niobate cubic perovskites have been obtained by recrystallization of reduced ternary ceramic precursors from borate fluxes under high-vacuum. Product formation could be influenced by variation of the alkaline-earth metal oxide content of the flux,

  18. Synthesis and properties of rubber-steel cord adhesion promoter nickel borate acylate

    Institute of Scientific and Technical Information of China (English)

    李晓如; 吴海鹰; 成本诚

    2002-01-01

    The synthesis of nickel borate acylate (NBA), a kind of rubber-steel cord adhesion promoter (AP), through nickel carbonate, borate and mixed carboxylic acid was studied. Nickel carbonate could be prepared by the reaction of nickel sulfate with sodium carbonate in aqueous solution. After strong stirring for 2h, the mixed nickel carboxylate could be synthesized by the reaction of nickel carbonate with isooctanoic acid and acetic acid. The mole ratio of these chemicals was 1∶1∶1.1. NBA was synthesized by reaction of mixed nickel carboxylate with tributyl borate under strong stirring at 200~250℃ for 6h. By detecting and comparing with 680C product from Manobond Company of England, the NBA synthesized through isooctanoic acid and tributyl borate is very similar with 680C in IR data, 300% fixed extension strength, tensile strength, hardness and cure curve. However, tensile failure extensibility and hot air aging of NBA are a little lower than those of 680C. The experimental results show that NBA can be used as rubber-steel cord AP.

  19. Tetrakis(1-imidazolyl) borate (BIM4) based zwitterionic and related molecules used as electron injection layers

    Science.gov (United States)

    Li, Huaping; Xu, Yunhua; Bazan, Guillermo C

    2013-02-05

    Tetrakis(1-imidazolyl)borate (BIm4) based zwitterionic and/or related molecules for the fabrication of PLEDs is provided. Device performances with these materials approaches that of devices with Ba/Al cathodes for which the cathode contact is ohmic. Methods of producing such materials, and electron injection layers and devices containing these materials are also provided.

  20. Preparation of α-Bromoketones Involving the Reaction of Enol Triethyl Borates with N-Bromosuccinimide

    Directory of Open Access Journals (Sweden)

    Izabella Jastrzebska

    2013-01-01

    Full Text Available The ketones (5α- and 5β-cholestan-3-one and (1S,7aS-1-tert-butoxy-hexahydro-7a-methyl-1H-inden-5-one were efficiently α-monobrominated by treatment of the corresponding enol triethyl borates with N-bromosuccinimide (NBS.

  1. Optical properties of Eu2+-doped strontium borate glasses containing F- and Li+ ions

    Institute of Scientific and Technical Information of China (English)

    HUANG Yanlin; JANG Kiwan; WANG Xigang; JIANG Chuanfang

    2008-01-01

    In this experiment, strontium borate glasses were prepared using the conventional quenching method in air atmosphere. Optical absorption, photoluminescence excitation and emission spectra, X-ray excited luminescence (XEL), and luminescence decay curve of the as-prepared glasses were investigated at room temperature. The as-prepared glasses had two kinds of Eu ions, i.e., Eu2+ and Eu3+. Compared with the reported results of strontium borate glasses, Eu2+ luminescence was enhanced in the studied strontium borate glasses coprepared with F- and Li+ ions. The coexisting of Li+ or F- in the borate glasses could create more negative defect VSr″ and stabilize Eu2+ ions, which might act as donor of electrons;For the F- doping, the new center of B(O, F)4 (or BO3F) and BO2F2 units could be considered to be the distorted (BO4), which were needed as a rigid framework to stabilize the divalent rare earth ions.

  2. DVD-d. "Borat", "United 93", "Must Daalia", "Vimm 2" / Andres Laasik

    Index Scriptorium Estoniae

    Laasik, Andres, 1960-2016

    2007-01-01

    Uued mängufilmide DVD-d : Larry Charlesi "Borat" (peaosas Sacha Baron Cohen; USA 2006), Paul Greengrassi "United 93" (USA 2006), Brian De Palma "Must Daalia" ("The Black Dahlia", USA 2006), Takashi Shimizu "Vimm 2" ("The Grudge 2", USA 2006)

  3. Potential wood protection strategies using physiological requirements of wood degrading fungi

    NARCIS (Netherlands)

    Sailer, M.F.; Etten, B.D. van

    2004-01-01

    Due to the increasing restrictions in the use of wood preserving biocides a number of potential biocide free wood preserving alternatives are currently assessed. Wood degrading fungi require certain conditions in the wood in order to be able to use wood as a food source. This paper discusses the phy

  4. Biochemical modification of wood components

    OpenAIRE

    Josefsson, Peter

    2006-01-01

    The degradation of cellulose found in wood is one of the most important degradation processes for the carbon flux on earth. The degradation is performed by microorganisms that typically use enzymes. Since the cellulose in wood is crystalline and embedded in other polymers, making it inaccessible and durable, the enzymatic methods of cellulose degradation is also complex. In this thesis, the action of some of these enzymes, called cellulases, have been studied both fundamentally and for indust...

  5. Tribology in secondary wood machining

    Energy Technology Data Exchange (ETDEWEB)

    Ko, P.L.; Hawthorne, H.M.; Andiappan, J.

    1998-07-01

    Secondary wood manufacturing covers a wide range of products from furniture, cabinets, doors and windows, to musical instruments. Many of these are now mass produced in sophisticated, high speed numerical controlled machines. The performance and the reliability of the tools are key to an efficient and economical manufacturing process as well as to the quality of the finished products. A program concerned with three aspects of tribology of wood machining, namely, tool wear, tool-wood friction characteristics and wood surface quality characterization, was set up in the Integrated Manufacturing Technologies Institute (IMTI) of the National Research Council of Canada. The studies include friction and wear mechanism identification and modeling, wear performance of surface-engineered tool materials, friction-induced vibration and cutting efficiency, and the influence of wear and friction on finished products. This research program underlines the importance of tribology in secondary wood manufacturing and at the same time adds new challenges to tribology research since wood is a complex, heterogeneous, material and its behavior during machining is highly sensitive to the surrounding environments and to the moisture content in the work piece.

  6. Pressure-Induced Phase Transitions In Gadolinium Iron Borate

    Science.gov (United States)

    Kharlamova, S. A.; Struzhkin, V. V.; Sinogeikin, S. V.; Gavriliuk, A. G.; Brown, D.; Toellner, T.; Zhao, J.; Lerche, M.; Lyubutin, I. S.; Ovchinnikov, S. G.; Alp, E. E.; Sturhahn, W.

    2007-12-01

    An understanding of spin crossover (SC) dynamics is relevant to understanding of a role or participation of SC in natural systems including lower Mantle minerals, heme proteins as well as from fundamental science of view. For example, pressure-induced electronic spin transitions of Fe2+ and Fe3+ iron occur in magnesiowustite, silicate perovskite and post-perovskite which are abundant minerals in the Earth's lower mantle [1-3]. Such a SC phenomenon has recently been observed in a number of magnetic minerals FeBO3 [4, 5], BiFeO3 [6], Fe2O3 [7], and Y3Fe5O12 [8], (La, Pr)FeO3 [9, 10]. In those cases, iron ions are in the trivalent state Fe3+ and the high-spin-low-spin (HS-LS) crossover is manifested as the collapse of the local magnetic moment and as the transition of the antiferromagnet to a paramagnetic state. For example, in FeBO3 at low temperatures a spin-crossover and some magnetic transitions with two triple points were found [4, 5]. Gadolinium iron borate, GdFe3(BO3)4 is also a system with SEC and recently, we have reported on phase transitions induced by high pressures in this material [11, 12]. We studied the structural and magnetic behavior of GdFe573(BO3)4 at high pressures and temperatures using a diamond anvil cell and a Synchrotron Mossbauer Spectroscopy technique. The hyperfine parameters and results obtained from the experiments are discussed. Based on our experimental data and theoretical calculation a tentative magnetic P-T phase diagram and an equation of states of GdFe573(BO3)4 are proposed. Important features of the phase diagram are a spin crossover, insulator-semiconductor transition and possible presence of two triple points where magnetic and paramagnetic phases of the high-spin and low-spin states coexist. 1. J. Badro, J.-P. Rueff, G. Vankó, et al., Science 305, 383 (2004). 2. J. M. Jackson, W. Sturhahn, G. Shen, et al., American Mineralogist 90, 199 (2005). 3. J.Li, V.V. Struzhkin, H.-K. Mao, et al., PNAS 101, 14027 (2004). 4. I.A. Troyan

  7. Facile preparation of nickel/carbonized wood nanocomposite for environmentally friendly supercapacitor electrodes

    Science.gov (United States)

    Yaddanapudi, Haritha Sree; Tian, Kun; Teng, Shiang; Tiwari, Ashutosh

    2016-09-01

    We are reporting a facile way to prepare nickel/carbon nanocomposites from wood as a novel electrode material for supercapacitors. The surface morphology and the structure of the as-prepared electrodes were studied by using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). The results indicate that after high-temperature carbonization process, the wood is converted into graphitic carbon with nickel nanoparticles uniformly distributed within the three dimensional structure of the wood. Electrochemical characterization such as cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and galvanostatic charge-discharge measurements were conducted. These results showed that the introduction of nickel into the carbonized wood improves the specific capacitance and the cyclic stability of the nanocomposite electrode over that of the pure carbonized wood electrode. The composite electrode displayed an enhanced capacitive performance of 3616 F/g at 8 A/g, and showed an excellent capacitance retention after 6000 charge-discharge cycles. These results endow the nickel nanoparticles impregnated carbonized wood with a great potential for future application in supercapacitors.

  8. Wood Xylowall: New process to reduce water exchange by an intra-graft of polymer

    Science.gov (United States)

    Uyttenhove, Anne; Tilquin, Bernard

    2005-07-01

    Our research shows that poplar treated with selected monomer mixture and then irradiated at 50 kGy reduces the water exchange without adversely altering the desirable qualities of wood. Moreover, the environment is not polluted. To retard changes in moisture content and dimensions, different commercial Radcures (UCB) were tested. A comparative study on the water retention showed significant reduction between non-treated and Xylowall wood for the species: poplar. The physical and mechanical measurements (density, volumetric shrinkage, elasticity, rupture, impact bending, hardness, compression strength) on poplar and pine show that the properties of the wood are not affected negatively by Xylowall treatment with irradiation. Moreover, the process does not discharge any toxic volatile residues into the atmosphere as proven by GC-MS trace analysis of heated wood samples. The stereomicroscope by imagery reveals an impregnation of 0.5 mm on cross-section of darker-stained areas, and sometimes more due to the texture (the relative size and arrangement of the wood cells) of the wood.

  9. Effect of Wood Variables on the Properties of Wood Fiber-Polypropylene Composites

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The effect of wood species (Chinese fir and Poplar), wood fiber content (10%, 25%, 40%) and wood fiber sizes (16 to 32 mesh, 32-65 mesh, above 65 mesh) on the properties of the wood fiber-Polypropylene composites were studied in this paper. The results indicate that the effect of wood fiber content and size in composite were more important than that of chosen wood species. Compared with polypropylene without wood fiber, the flexural strength of the composites increased when adding wood fiber into polypr...

  10. Swelling of acetylated wood in organic liquids

    CERN Document Server

    Obataya, E; Obataya, Eiichi; Gril, Joseph

    2005-01-01

    To investigate the affinity of acetylated wood for organic liquids, Yezo spruce wood specimens were acetylated with acetic anhydride, and their swelling in various liquids were compared to those of untreated specimens. The acetylated wood was rapidly and remarkably swollen in aprotic organic liquids such as benzene and toluene in which the untreated wood was swollen only slightly and/or very slowly. On the other hand, the swelling of wood in water, ethylene glycol and alcohols remained unchanged or decreased by the acetylation. Consequently the maximum volume of wood swollen in organic liquids was always larger than that in water. The effect of acetylation on the maximum swollen volume of wood was greater in liquids having smaller solubility parameters. The easier penetration of aprotic organic liquids into the acetylated wood was considered to be due to the scission of hydrogen bonds among the amorphous wood constituents by the substitution of hydroxyl groups with hydrophobic acetyl groups.

  11. wood burns down

    Directory of Open Access Journals (Sweden)

    Vladimir Bukh

    2004-11-01

    Full Text Available To relax the local authorities and to receive the guests of high rank «with no tie» the so-called «Fisherman's House» was built at the source of Angara-river, near Lake Baikal. Vladimir Ivanov, a young architect, was noticed by his skillful performa nee of exclusive orders and became the author of this house. At the time of ferroconcrete boom the proposal to build a wooden guest house turned out to be unexpectedly to the point and was graciously approved. The economic department was entrusted to select the men good for carpenter's work, and the forestry department was entrusted to provide thick round timber. And the work started. But, as it usually happens, the workers did not take the trouble and made the first eight rims of the current timber with an inappropriate diameter.And when Pavlov insisted on demolishing the construction and replacing the logs by the logs with the necessary diameter, the building work obeyed to his will and was finished suecessfully.The architecture of the house is not the derived action of the saw and the fret-saw. It is a technology of the axe. It is natural, convincing and original. It is no use to look for the local sources in it. It grew up in the area of timber and cold winter. And this clear and efficient action kept the construction from the annoying vulgarity and provided Siberian exotics easily penetrating into one's soul, refined as it may be.One of the eminent guests said with admiration: «Even if Pavlov had created nothing more, he would have justified his professional choice with this single house.» Why not to say it as a good toast. However, this is a suitable case to add: style is an absence of style. It is a taste.After the Fisherman's House Irkutsk architects were attracted by wood. They followed the strictness in wood and, as much as they could, created a couple of successful remakes, until the cylinder logs and ... new

  12. Borate cross-linked graphene oxide-chitosan as robust and high gas barrier films

    Science.gov (United States)

    Yan, Ning; Capezzuto, Filomena; Lavorgna, Marino; Buonocore, Giovanna G.; Tescione, Fabiana; Xia, Hesheng; Ambrosio, Luigi

    2016-05-01

    Chitosan (CS) is one of the most promising polymers due to its biocompatibility, biodegradability, and natural abundance. However, its poor mechanical and barrier properties make it difficult to satisfy a wide range of applications. Herein, borate ions, originating from the hydrolysis of sodium tetraborate decahydrate (borax), have been used to crosslink chitosan and graphene oxide (GO) nanocomposites. Chitosan films consisting of 1.0 wt% boron and 1.0 wt% GO exhibit a significant improvement in both the toughness and oxygen barrier properties compared to pristine chitosan. In particular the tensile strength of the samples after thermal treatment increases by ~160% compared to pristine chitosan, whereas their oxygen permeability reduces by ~90%. This is ascribed to the chemical crosslinking between chitosan and GO nanoplatelets through borate ions, as well as the formation of a layered morphology with graphene nanoplatelets oriented parallel to the sample surface. The exceptional robust and high gas barrier film has promising application in the packaging industry. The borate-crosslinking chemistry represents the potential strategy for improving properties of other polymer nanocomposites.Chitosan (CS) is one of the most promising polymers due to its biocompatibility, biodegradability, and natural abundance. However, its poor mechanical and barrier properties make it difficult to satisfy a wide range of applications. Herein, borate ions, originating from the hydrolysis of sodium tetraborate decahydrate (borax), have been used to crosslink chitosan and graphene oxide (GO) nanocomposites. Chitosan films consisting of 1.0 wt% boron and 1.0 wt% GO exhibit a significant improvement in both the toughness and oxygen barrier properties compared to pristine chitosan. In particular the tensile strength of the samples after thermal treatment increases by ~160% compared to pristine chitosan, whereas their oxygen permeability reduces by ~90%. This is ascribed to the chemical

  13. NMR and Nqr Study of Atomic Order in Alkali Borate Glasses.

    Science.gov (United States)

    Gravina, Samuel John

    A modified Robinson oscillator circuit was built for the detection of nuclear quadrupole resonance (NQR) in the 200 to 10,000 kHz region. The circuit demonstrates near ideal performance with the detected noise limited only by the sample temperature. The use of computer controlled data acquisition and a carefully designed sample probe allows for the use of an integrating time constant of up to 6 hours. This spectrometer has been used to detect ^{10}B and ^{11 }B NQR in lithium and sodium borate glasses and crystals. In pure boron oxide glass two distinct boron sites are found. By comparing this experiment with previous NMR and Raman spectroscopy studies, one of the sites, which comprises 85% of the total boron, can be attributed to boron atoms in boroxol rings. As sodium is added to the glass the abundance of boroxol rings decreases. At 20 mol% sodium oxide less than 2% of the boron atoms are found in boroxol rings. The dipole-dipole interaction between lithium cations and four-coordinated boron atoms (B_4 units) has been measured. It is found that every B_4 unit has one lithium cation next to it at an average distance of 2.82 A. A comparison with lithium borate crystals shows that diborate groups do not occur in significant quantities. Both high field and low field NMR studies of the boron quadrupole interaction in a B_4 unit also show that diborate groups are not found in the glass. A ^{23}Na and ^6Li NMR MASS study of lithium and sodium borate glasses shows that ^{23 }Na chemical shifts can distinguish sodium cations bound to non-bridging oxygens from sodium cations bound to bridging oxygens. The chemical shifts measured in lithium-sodium borate glasses are identical to those measured in lithium borate or sodium borate glasses, indicating similar alkali-oxygen coordination. A significant narrowing of the ^6Li NMR spectrum in a mixed alkali glass can be understood as a decrease in the entropy of the lithium cations. This result is consistent with the weak

  14. Interface Characteristics of Wood-hybrid Composites

    Institute of Scientific and Technical Information of China (English)

    XUEFenglian; ZHAOGuangjie

    2005-01-01

    In order to understand the current interface characteristics of wood-hybrid composites, this paper starts off from the concept of composite interface and general theory of interface form, then the inner-surface and microstructure of wood and the interface characteristics of composites, such as wood- inorganic, wood-plastic and wood- metal made by electroless plating technique, are concluded and discussed in detail. Meanwhile,on the basis of that, some points of view about how to develop the wood-hybrid composites interface research in the future are also proposed.

  15. WOOD MODIFICATION BY HEAT TREATMENT: A REVIEW

    Directory of Open Access Journals (Sweden)

    Bruno M. Esteves

    2009-02-01

    Full Text Available Wood heat treatment has increased significantly in the last few years and is still growing as an industrial process to improve some wood properties. The first studies on heat treatment investigated mainly equilibrium mois-ture, dimensional stability, durability and mechanical properties. Mass loss, wettability, wood color, and chemical transformations have been subsequently extensively studied, while recent works focus on quality control, modeling, and study the reasons for the improvements. This review explains the recent interest on the heat treatment of wood and synthesizes the major publications on this subject on wood properties, chemical changes, wood uses, and quality control.

  16. Low-spin hexacoordinate Mn(III): synthesis and spectroscopic investigation of homoleptic tris(pyrazolyl)borate and tris(carbene)borate complexes.

    Science.gov (United States)

    Forshaw, Adam P; Smith, Jeremy M; Ozarowski, Andrew; Krzystek, J; Smirnov, Dmitry; Zvyagin, S A; Harris, T David; Karunadasa, Hemamala I; Zadrozny, Joseph M; Schnegg, Alexander; Holldack, Karsten; Jackson, Timothy A; Alamiri, Ahmad; Barnes, Diane M; Telser, Joshua

    2013-01-07

    Three complexes of Mn(III) with "scorpionate" type ligands have been investigated by a variety of physical techniques. The complexes are [Tp(2)Mn]SbF(6) (1), [Tp(2)*Mn]SbF(6) (2), and [{PhB(MeIm)(3)}(2)Mn](CF(3)SO(3)) (3a), where Tp(-) = hydrotris(pyrazolyl)borate anion, Tp*(-) = hydrotris(3,5-dimethylpyrazolyl)borate anion, and PhB(MeIm)(3)(-) = phenyltris(3-methylimidazol-2-yl)borate anion. The crystal structure of 3a is reported; the structures of 1 and 2 have been previously reported, but were reconfirmed in this work. The synthesis and characterization of [{PhB(MeIm)(3)}(2)Mn]Cl (3b) are also described. These complexes are of interest in that, in contrast to many hexacoordinate (pseudo-octahedral) complexes of Mn(III), they exhibit a low-spin (triplet) ground state, rather than the high-spin (quintet) ground state. Solid-state electronic absorption spectroscopy, SQUID magnetometry, and high-frequency and -field electron paramagnetic resonance (HFEPR) spectroscopy were applied. HFEPR, in particular, was useful in characterizing the S = 1 spin Hamiltonian parameters for complex 1, D = +19.97(1), E = 0.42(2) cm(-1), and for 2, D = +15.89(2), E = 0.04(1) cm(-1). In addition, frequency domain Fourier-transform THz-EPR spectroscopy, using coherent synchrotron radiation, was applied to 1 only and gave results in good agreement with HFEPR. Variable-temperature dc magnetic susceptibility measurements of 1 and 2 were also in good agreement with the HFEPR results. This magnitude of zero-field splitting (zfs) is over 4 times larger than that in comparable hexacoordinate Mn(III) systems with S = 2 ground states. Complexes 3a and 3b (i.e., regardless of counteranion) have a yet much larger magnitude zfs, which may be the result of unquenched orbital angular momentum so that the spin Hamiltonian model is not appropriate. The triplet ground state is rationalized in each complex by ligand-field theory (LFT) and by quantum chemistry theory, both density functional theory and

  17. Fluorescence properties of Eu 3+ ions doped borate and fluoroborate glasses containing lithium, zinc and lead

    Science.gov (United States)

    Venkatramu, V.; Babu, P.; Jayasankar, C. K.

    2006-02-01

    The influence of glass composition on the fluorescence properties of Eu 3+ ions doped borate and fluoroborate glasses modified with Li +, Zn 2+ and Pb 2+ cations have been investigated. The magnitude of splittings of 7F 1 levels are analyzed using crystal-field (CF) analysis. The relative intensities of 5D 0 → 7F 2 to 5D 0 → 7F 1 transitions, crystal-field strength parameters and decay times of the 5D 0 level have been determined and are found to be lower for Pb based glasses than those of Zn/Li based glasses. The lifetimes of 5D 0 level are found to increase when borate glasses are modified with pure fluorides than with oxides and oxyfluorides. The fluorescence decay of 5D 0 level fits perfect single exponential in the Eu 3+:glass systems studied which indicates the absence of energy transfer between Eu 3+ ions in these glasses.

  18. Erbium-doped oxide and oxyhalide lead borate glasses for near-infrared broadband optical amplifiers

    Science.gov (United States)

    Pisarski, Wojciech A.; Pisarska, Joanna; Lisiecki, Radosław; Grobelny, Łukasz; Dominiak-Dzik, Grażyna; Ryba-Romanowski, Witold

    2009-04-01

    Near-infrared luminescence spectra at 1.53 μm due to main 4I 13/2- 4I 15/2 laser transition of Er 3+ ions in oxide and oxyhalide lead borate glasses were examined. Spectroscopic parameters like spectral linewidth and luminescence lifetime were analyzed with PbX 2 (X = F, Cl or Br) doping. An introduction of lead halide to the borate glass results in the reduction of spectral linewidth and the increase of luminescence lifetime of Er 3+. The luminescence decay from the 4I 13/2 upper state of Er 3+ is longer for glass sample with PbF 2 than PbX 2 (X = Cl or Br).

  19. Intense upconversion fluorescence in Tm 3+/Yb3+ codoped alumina lead borate glasses

    Science.gov (United States)

    Krishna Murthy Goud, K.; Shekhar Reddy, M. Chandra; Appa Rao, B.

    2016-09-01

    The Tm3+/Yb3+ codoped alumina lead borate glasses were prepared by the conventional melt quenching technique. Optical absorption and FTIR spectra were recorded. The upconversion fluorescence spectra exhibited weak blue (480 nm) and intense red (660 nm) emissions due to 1G4 → 3H6 and 1G4 → 3H4 transitions, respectively. The results concluded that both emissions are due to three photon absorption process. It has been observed that in the upconversion efficiency increases with the increase in the concentration of Yb3+ ions. The strong red upconversion fluorescence indicate that Tm3+/Yb3+ codoped alumina lead borate glasses can be used as potential host material for upconversion lasers.

  20. Structural role of europium ions in lead -borate glasses inferred from spectroscopic and DFT studies

    Science.gov (United States)

    Rada, S.; Culea, M.; Neumann, M.; Culea, E.

    2008-07-01

    Glasses in the system xEu 2O 3 · (100 - x)[3B 2O 3·PbO] with 0 ⩽ x ⩽ 35 mol% have been prepared from melt quenching method. Structural changes, as recognized by analyzing band shapes of IR spectra, revealed that Eu 2O 3 causes a change from the continuous borate network to the continuous lead-borate network, interconnected through Pb-O-B and B-O-B bridges. DFT calculations show that lead atoms occupy three different sites in the proposed model. Comparing the theoretical and experimental data, we conclude that the performance of the method/basis sets used on the prediction of the structural data and vibrational modes is good.

  1. Rare earth-doped lead borate glasses and transparent glass-ceramics: Structure-property relationship

    Science.gov (United States)

    Pisarski, W. A.; Pisarska, J.; Mączka, M.; Lisiecki, R.; Grobelny, Ł.; Goryczka, T.; Dominiak-Dzik, G.; Ryba-Romanowski, W.

    2011-08-01

    Correlation between structure and optical properties of rare earth ions in lead borate glasses and glass-ceramics was evidenced by X-ray-diffraction, Raman, FT-IR and luminescence spectroscopy. The rare earths were limited to Eu 3+ and Er 3+ ions. The observed BO 3 ↔ BO 4 conversion strongly depends on the relative PbO/B 2O 3 ratios in glass composition, giving important contribution to the luminescence intensities associated to 5D 0- 7F 2 and 5D 0- 7F 1 transitions of Eu 3+. The near-infrared luminescence and up-conversion spectra for Er 3+ ions in lead borate glasses before and after heat treatment were measured. The more intense and narrowing luminescence lines suggest partial incorporation of Er 3+ ions into the orthorhombic PbF 2 crystalline phase, which was identified using X-ray diffraction analysis.

  2. Synthesis, characterization, thermal and antioxidant studies of potassium dihydrobisphenothiazinyl borate and its transition metal complexes.

    Science.gov (United States)

    Nami, Shahab A A; Alam, Mahboob; Husain, Ahmad; Parveen, Mehtab

    2012-10-01

    The bidentate borate anion H(2)B(ptz)(2)(-) and its transition metal complexes have been synthesized and characterized by elemental analyses, magnetic susceptibility, electronic, IR, (1)H and (13)C NMR data. The molar conductance of 10(-3) M solution for all the complexes supports their non-ionic nature. The TGA profile of borate anion shows a single stage unlike that of two stage decomposition plot of the metal complexes. On the basis of spectroscopic studies the geometry of all the complexes have been proposed to be distorted-tetrahedral. The in vitro antioxidant and lipid oxidation inhibition of the ligand and its complexes have also been studied. The Cu[B(ptz)(2)](2) complex was found to be most effective in all the studies.

  3. Rare earth-doped lead borate glasses and transparent glass-ceramics: structure-property relationship.

    Science.gov (United States)

    Pisarski, W A; Pisarska, J; Mączka, M; Lisiecki, R; Grobelny, Ł; Goryczka, T; Dominiak-Dzik, G; Ryba-Romanowski, W

    2011-08-15

    Correlation between structure and optical properties of rare earth ions in lead borate glasses and glass-ceramics was evidenced by X-ray-diffraction, Raman, FT-IR and luminescence spectroscopy. The rare earths were limited to Eu(3+) and Er(3+) ions. The observed BO(3)↔BO(4) conversion strongly depends on the relative PbO/B(2)O(3) ratios in glass composition, giving important contribution to the luminescence intensities associated to (5)D(0)-(7)F(2) and (5)D(0)-(7)F(1) transitions of Eu(3+). The near-infrared luminescence and up-conversion spectra for Er(3+) ions in lead borate glasses before and after heat treatment were measured. The more intense and narrowing luminescence lines suggest partial incorporation of Er(3+) ions into the orthorhombic PbF(2) crystalline phase, which was identified using X-ray diffraction analysis.

  4. Synergistic effects of zinc borate and aluminium trihydroxide on flammability behaviour of aerospace epoxy system

    Directory of Open Access Journals (Sweden)

    2009-06-01

    Full Text Available The flame retardancy of mono-component epoxy resin (RTM6, widely used for aerospace composites, treated with zinc borate (ZB, aluminium trihydroxide (ATH and their mixtures at different concentrations have been investigated by morphological and thermal characterization. Cone calorimeter data reveal that combustion behaviour, heat release rate peak (PHRR and heat release rate average (HRR Average of RTM6 resin decrease substantially when synergistic effects of zinc borate and aluminium trihydroxide intervene. Thermogravimetric (TGA results and analysis of the residue show that addition higher than 20% w/w of ZB, ATH, and their mixture greatly promotes RTM6 char formation acting as a barrier layer for the fire development. Depending upon the different used flame additives, SEM micrographs indicate that the morphology of residual char could vary from a compact amalgam-like structure, for the RTM6+ZB system, to a granular structure, characterized by very small particles of degraded resin and additive for the ATH.

  5. Structural systematic and crystal chemistry of novel borates with REE, Pb, Sr, and alkali metals

    Energy Technology Data Exchange (ETDEWEB)

    Belokoneva, E.L. [Moscow State Univ., Moscow (Russian Federation). Dept. of Crystallography and Crystal Chemistry

    2013-11-01

    Crystal structures of novel borates with REE, Pb, Sr and alkali metals were analyzed using classical fundamental buildings blocks approach. It is demonstrated that hexa-, penta-, tetra-, tri- and diborates subdivisions in systematic are real families of structures with the common peculiarities. According to the symmetrical way and the degree of FBB condensation structural-generic rows exist in every of subdivisions. Mega- or polyborates subdivision is valid for the structures with the different types of simplest FBB. In all new complex borates it is possible to separate FBB of equal or different types which are presented in isolated form or are connected into chains, layers or frameworks, and to find unexpected correlation between structures. The possibility to recognize and to visualize in this approach the polarity or non-polarity of the structural units and correspondingly the polarity or nonpolarity of the structures in the whole is very important for the conclusion on structure-properties relation. (orig.)

  6. Computational investigation of the neutron shielding and activation characteristics of borated concrete with polyethylene aggregate

    Energy Technology Data Exchange (ETDEWEB)

    Park, S.J.; Jang, J.G.; Lee, H.K., E-mail: leeh@kaist.ac.kr

    2014-09-15

    This paper presents the result of a computational study to investigate the neutron shielding and activation characteristics of concretes containing boron carbide and polyethylene. Various mixes were considered with changes in the contents of boron carbide and polyethylene aggregate. The Monte Carlo simulation code MCNP-5 was utilized to determine the transmission of neutron through concrete at different energies from 0.1 eV to 1 MeV, and ORIGEN-S code was then used to predict activation characteristics of the concretes. It was shown that the replacement of polyethylene in borated concrete greatly enhanced the shielding efficiency of the concrete, and total activity levels of the concrete were considerably decreased with this replacement. Furthermore, double-layered structures having the first layer of polyethylene aggregate-replaced concrete and the second layer of 2 wt% borated concrete are shown to improve shielding efficiency more significantly than monolithic structures.

  7. Preparation of Chromium Oxide Coatings on Aluminum Borate Whiskers by a Hydrothermal Deposition Process

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Aluminum borate whiskers (9Al2O32B2O3) can be used to reinforce aluminum alloys to produce light and strong composites. However, the adverse interfacial reactions between the whiskers and the aluminum alloys inhibit their practical uses; therefore, a protective coating is needed on whiskers. In this work, aluminum borate whiskers were coated with chromium-coating deposits in a hydrothermal solution containing CrCl3, Na2C4H4O6, NaPH2O2, and H3BO3. The presence of the impurity P in the hydrothermal deposits can be avoided by reducing the amount of NaPH2O2 in the coating solution. Thermodynamic analysis was used to discuss the behavior of ions in the coating process. The subsequent heating of the hydrothermal products in air at 800 ℃ yielded smooth Cr2O3 films with a thickness of 0.060.07 μm.

  8. Fast Decomposition Procedure of Solid Samples by Lithium Borates Fusion Employing Salicylic Acid.

    Science.gov (United States)

    Trdin, Miha; Nečemer, Marijan; Benedik, Ljudmila

    2017-03-07

    A new fast decomposition procedure for solid samples was developed. In this study, we investigated decomposition of samples by lithium borates fusion in combination with salicylic acid. The method described shortens the time required for the sample to be digested and loaded to a resin to up to 2 h, and it was especially suitable for alpha spectrometry measurements in emergency situations. Additionally, the method results in high radiochemical recoveries and when compared to other digestion methods (classical digestion utilizing mineral acids, microwave digestion, and lithium borates fusion in combination with polyethylene glycol (PEG)) gives comparable activity concentration values. The method used was applied to various reference materials with inorganic and organic matrices as well as widely varying amounts of uranium radioisotopes content. The results obtained were compared with reference and literature values and show that the proposed method can be successfully implemented on various types of samples.

  9. Optical absorption and fluorescence properties of Er3+ in sodium borate glass

    Indian Academy of Sciences (India)

    Y C Ratnakaram; J Lakshmi; R P S Chakradhar

    2005-08-01

    Spectroscopic properties of Er3+ ions in sodium borate glass have been studied. The indirect and direct optical band gaps (opt) and energy level parameters (Racah (1, 2 and 3), spin-orbit (4f) and configurational interaction ()) are evaluated. Spectral intensities for various absorption bands of Er3+ doped sodium borate glass are calculated. Using Judd–Ofelt intensity parameters (2, 4, 6), radiative transition probabilities (), branching ratios () and integrated absorption cross sections ( ) are reported for certain transitions. The radiative lifetimes (R) for different excited states are estimated. From the fluorescence spectra, the emission cross section (p) for the transition, ${}^{4}I_{13/2} \\rightarrow {}^{4}I_{15/2}$ is reported.

  10. Wood-pastures of Europe

    DEFF Research Database (Denmark)

    Plieninger, Tobias; Hartel, Tibor; Martín-López, Berta

    2015-01-01

    , cultural heritage, and rich traditional ecological knowledge. We discuss the anthropogenic character of wood-pastures, requiring multifunctional land management, which is a major conservation challenge. Despite increasing societal appreciation of wood-pastures, their integration into effective agricultural......-pastures have found increasing attention from conservation science and policy across Europe. In this paper we (i) perform the first pan-European assessment of wood-pastures, considering individual countries and biogeographic regions, (ii) present the ecological and social-cultural values of a wide diversity...... and conservation policies has proved to be complicated, because institutional structures are traditionally organized within mono-functional sectors. We offer suggestions as to how these shortcomings might be overcome in the Common Agricultural Policy, including Rural Development policy, and the Habitats Directive...

  11. Drug Retention Times

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    2007-05-01

    The purpose of this monograph is to provide information on drug retention times in the human body. The information provided is based on plausible illegal drug use activities that might be engaged in by a recreational drug user. Based on anecdotal evidence, most people “party” during extended time away from the work environment. Therefore, the following scenarios were envisioned: (1) a person uses an illicit drug at a party on Saturday night (infrequent user); (2) a person uses a drug one time on Friday night and once again on Saturday night (infrequent user); and (3) a person uses a drug on Friday night, uses a drug twice on Saturday night, and once again on Sunday (frequent user).

  12. Ultrasonic and Thermal Properties of Borate and Phosphate Glasses Containing Bismuth and Lead

    Science.gov (United States)

    Aziz, Sidek Hj. Abd.; Ahmad, Hamezan; Wahab, Zaidan A.; Sulaiman, Zainal Abidin; Talib, Zainal Abidin; Shaari, A. Halim; Senin, H. B.

    2007-05-01

    Systematic series of (B2O3,P2O5)-Bi2O3-PbO glasses have been successfully prepared by using the rapid quenching technique in which each oxide content changes for every series on the basis of its weight percentage. Their amorphous natures were confirmed earlier by the x-ray diffraction technique. The experimental results show that the density of both glasses, determined by using the Archimedes principle, increases with the glass modifier content. This is due to the replacement of Bi2O3 and PbO in the borate and phosphate glassy networks. The molar volume for borate glass increases with the addition of bismuth and lead oxides, but a reverse trend occurs for the phosphate glass. The longitudinal and shear ultrasound velocities, determined by the MBS 8000 system, of both lead bismuth borate and phosphate glasses show a decreasing trend as more PbO and Bi2O3 are added to the glass system. The increase in PbO/Bi2O3 content was probably related to the progressive increase in the concentration of non-bridging oxygen (NBOs). Thermal studies of the glass, using the Labsys DTA-Setaram machine, show that the value of the glass transition temperature (Tg) is closely related to the chemical bond in the system. In lead bismuth borate glasses, the addition of more Pb2+ and Bi3+ results in a more dominant ionic bond character in the system and hence decreases Tg of the sample. However, in lead bismuth phosphate glasses, the addition of Pb2+ and Bi3+ not only failed to weaken the covalent character in P-O-P bonds, but strengthened it further, leading to an increment in the values of Tg.

  13. Structural studies of lead lithium borate glasses doped with silver oxide

    Science.gov (United States)

    Coelho, João; Freire, Cristina; Hussain, N. Sooraj

    2012-02-01

    Silver oxide doped lead lithium borate (LLB) glasses have been prepared and characterized. Structural and composition characterization were accessed by XRD, FTIR, Raman, SEM and EDS. Results from FTIR and Raman spectra indicate that Ag 2O acts as a network modifier even at small quantities by converting three coordinated to four coordinated boron atoms. Other physical properties, such as density, molar volume and optical basicity are also evaluated. Furthermore, they are also affected by the silver oxide composition.

  14. Spectroscopic studies of lead antimony borate glasses doped with erbium ions

    Science.gov (United States)

    Reddy, M. Chandra Shekhar; Goud, K. Krishna Murthy; Dharmaiah, P.; Rao, B. Appa

    2013-06-01

    Antimony borate glasses of the composition 30PbO-25Sb2O3-(45-x)B2O3-xEr2O3 with x = 0 to 1.0 in steps of 0.2 were prepared by the melt-quenching method. Various physical parameters. radiative parameters, transition probability A, branching ratio β and the radiative life time τ for different emission levels of Er3+ ions, have been evaluated.

  15. Structure and Properties of Reduced Barium Niobium Oxide Single Crystals Obtained from Borate Fluxes

    NARCIS (Netherlands)

    Hessen, B.; Sunshine, S.A.; Siegrist, T.; Fiory, A.T.; Waszczak, J.V.

    1991-01-01

    Single crystals of the reduced niobate Ba2Nb15O32 are produced by heating NbO2 in BaO·3B2O3 under high-vacuum conditions. The borate acts both as a source of BaO and as a flux for crystallization. The compound Ba2Nb15O32 crystallizes in space group R3 (a = 7.777 (1) Å, c = 35.518 (6) Å) and contains

  16. The prediction of borate mineral equilibria in natural waters: Application to Searles Lake, California

    Science.gov (United States)

    Felmy, Andrew R.; Weare, John H.

    1986-12-01

    The chemical equilibrium model of HARVIEet al. (1984) has been extended to include borate species. The model is based upon the semi-empirical equations of PITZER (1973) and coworkers and is valid to high ionic strength (≈14 m) and high borate concentration. Excellent agreement with the existing emf, isopiestic and solubility data in the system (Na-K-Ca-Mg-H-Cl-SO4-CO2-B(OH)4-H2O) is obtained. Calculated mineral solubilities are in general within 10% of their experimental values, even at high ionic strengths. The model was applied to the multicomponent, high ionic strength (I ~ 10) and high borate concentration (BT ~ 0.5 m) Searles Lake evaporite deposit. Utilizing the chemical composition of the interstitial brine, the model predicts equilibrium between the brine and only those minerals which are known to be in contact with the brine. These calculations clearly demonstrate the applicability of the model to high ionic strength, high borate concentration natural waters. The model was also utilized to calculate the mineral sequences which should result from evaporation of the major source of water for Searles Lake, the Owens River. The geochemical conditions necessary for the formation of the most recent mud and saline units are examined. The final results indicate that the mineral sequences found in the most recent saline unit in Searles Lake can be produced by evaporation of a water close in composition to present Owens River water, provided primary dolomite formation is delayed and back reaction between the Parting Mud and the Upper Salt is inhibited.

  17. Surprising coordination for plutonium in the first plutonium(III) borate.

    Science.gov (United States)

    Wang, Shuao; Alekseev, Evgeny V; Depmeier, Wulf; Albrecht-Schmitt, Thomas E

    2011-03-21

    The first plutonium(III) borate, Pu(2)[B(12)O(18)(OH)(4)Br(2)(H(2)O)(3)]·0.5H(2)O, has been prepared by reacting plutonium(III) with molten boric acid under strictly anaerobic conditions. This compound contains a three-dimensional polyborate network with triangular holes that house the plutonium(III) sites. The plutonium sites in this compound are 9- and 10-coordinate and display atypical geometries.

  18. Fuel wood symposium; Symposium Energieholz

    Energy Technology Data Exchange (ETDEWEB)

    Wild, C.; Wauer, A. (comps.)

    2001-07-01

    The Bavarian State Institute of Forestry (LWF) organised a 'Fuel Wood Symposium' in Freising-Weihenstephan on 17.11.2000. The purpose of this specialist conference was to give an overview of the use of biomass, especially wood, as an source of energy. (orig.) [German] Die Bayerische Landesanstalt fuer Wald und Forstwirtschaft richtete am 17.11.2000 in Freising-Weihenstephan das 'Symposium Energieholz' aus. Ziel der Fachtagung war es, einen Ueberblick ueber die energetische Nutzung von Biomasse, insbesondere Holz, zu geben. (orig.)

  19. Review on Wood Discoloration and its Control

    Institute of Scientific and Technical Information of China (English)

    JIANG Zehui; LV Wenhua; FEI Benhua; REN Haiqing; WU Yuzhang

    2006-01-01

    This paper reviews the mechanisms,types, compositions, affecting factors,prevention and remediable treatments of wood discoloration, and especially puts forward the biological control against wood stain and wood induced coloration.The authors think the followings are important:1)Developing the low poisonous or non-toxic, high-efficient and multi-functional anti-stain chemicals is still an important research direction to control wood discoloration.2)It is still very necessary to remove wood stain and restore wood original color and commercial value.3)The biological control has little environmental pollution and its cost is low.Researches on its theories and application should be strengthened.4)Wood color can be induced and turned to be the needed through heat treatment or ultraviolet irradiation without coloring materials,i.e.induced coloration,is a good idea to modulate wood,bamboo or rattan cane color.Itis becoming a new study field.

  20. SYNERGISTIC WOOD PRESERVATIVES FOR REPLACEMENT OF CCA

    Science.gov (United States)

    The objective of this project was to evaluate the potential synergistic combinations of environmentally-safe biocides as wood preservatives. These wood preservatives could be potential replacements for the heavy-metal based CCA.Didecyldimethylammonium chloride [DDAC] was...

  1. Toward a Record Retention Policy

    Science.gov (United States)

    Vaughan, Jason

    2007-01-01

    An academic library working group was charged in 2005 to create a records retention schedule and policy applicable to records containing personally identifiable information of library patrons. This group conducted a survey and extensive research, culminating in an adopted library records retention schedule and policy implemented in 2006.

  2. Compositional-dependent lead borate based glasses doped with Eu3+ ions: Synthesis and spectroscopic properties

    Science.gov (United States)

    Pisarski, W. A.; Pisarska, J.; Dominiak-Dzik, G.; Mączka, M.; Ryba-Romanowski, W.

    2006-12-01

    New multicomponent lead borate based glasses with various PbO/B2O3 weight ratio were prepared. The glass samples were analyzed in detail by using Raman and IR absorption spectroscopy. Optical properties of Eu3+ ions have been investigated in lead borate based systems, in which PbO/B2O3 weight ratios were changed from 1:2 to 8:1 in glass composition. The values of the phonon energy of the host and 5D0 lifetime of Eu3+ decrease, whereas absorption and emission intensities, as well as bonding parameter increase with increasing PbO concentration. Additionally, spectral lines are shifted in direction to the lower frequency region. Non-monotonic dependence of the fluorescence intensity ratio R (5D0 7F2/5D0 7F1) upon PbO/B2O3 content has been observed in contrast to bonding parameter that is also non-linear but monotonic. Some structural and spectroscopic aspects for Eu-doped lead borate based glasses are presented.

  3. VO 2+ ions in zinc lead borate glasses studied by EPR and optical absorption techniques

    Science.gov (United States)

    Prakash, P. Giri; Rao, J. Lakshmana

    2005-09-01

    Electron paramagnetic resonance (EPR) and optical absorption spectra of vanadyl ions in zinc lead borate (ZnO-PbO-B 2O 3) glass system have been studied. EPR spectra of all the glass samples exhibit resonance signals characteristic of VO 2+ ions. The values of spin-Hamiltonian parameters indicate that the VO 2+ ions in zinc lead borate glasses were present in octahedral sites with tetragonal compression and belong to C 4V symmetry. The spin-Hamiltonian parameters g and A are found to be independent of V 2O 5 content and temperature but changing with ZnO content. The decrease in Δ g∥/Δ g⊥ value with increase in ZnO content indicates that the symmetry around VO 2+ ions is more octahedral. The decrease in intensity of EPR signal above 10 mol% of V 2O 5 is attributed to a fall in the ratio of the number of V 4+ ions ( N4) to the number of V 5+ ions ( N5). The number of spins ( N) participating in resonance was calculated as a function of temperature for VO 2+ doped zinc lead borate glass sample and the activation energy was calculated. From the EPR data, the paramagnetic susceptibility was calculated at various temperatures and the Curie constant was evaluated from the 1/ χ- T graph. The optical absorption spectra show single absorption band due to VO 2+ ions in tetragonally distorted octahedral sites.

  4. Laser spectroscopy of Nd 3+ and Dy 3+ ions in lead borate glasses

    Science.gov (United States)

    Pisarska, Joanna; Pisarski, Wojciech A.; Ryba-Romanowski, Witold

    2010-07-01

    The spectroscopic and laser properties of Nd 3+ and Dy 3+ ions in lead borate glass were studied. Luminescence spectra recorded in the near-infrared and visible ranges correspond to 4F 3/2- 4I J/2 ( J=9, 11, 13) transitions of Nd 3+ and 4F 9/2- 6H J/2 ( J=11, 13, 15) transitions of Dy 3+, respectively. Luminescence decay curves were analyzed as a function of activator concentration. Luminescence quenching is observed, which is due to Ln-Ln interaction increasing. Several spectroscopic parameters relevant to laser potential of Ln 3+ ions (Ln=Nd, Dy) in lead borate glass were determined. The relatively large values of the quantum efficiency and the room-temperature emission cross-section for the 4F 3/2- 4I 11/2 transition of Nd 3+ at 1061 nm and the 4F 9/2- 6H 13/2 transition of Dy 3+ at 573 nm imply that Ln-doped lead borate glasses can be considered as promising solid-state materials for laser applications.

  5. Evaluation of borate bioactive glass scaffolds with different pore sizes in a rat subcutaneous implantation model.

    Science.gov (United States)

    Deliormanli, Aylin M; Liu, Xin; Rahaman, Mohamed N

    2014-01-01

    Borate bioactive glass has been shown to convert faster and more completely to hydroxyapatite and enhance new bone formation in vivo when compared to silicate bioactive glass (such as 45S5 and 13-93 bioactive glass). In this work, the effects of the borate glass microstructure on its conversion to hydroxyapatite (HA) in vitro and its ability to support tissue ingrowth in a rat subcutaneous implantation model were investigated. Bioactive borate glass scaffolds, designated 13-93B3, with a grid-like microstructure and pore widths of 300, 600, and 900 µm were prepared by a robocasting technique. The scaffolds were implanted subcutaneously for 4 weeks in Sprague Dawley rats. Silicate 13-93 glass scaffolds with the same microstructure were used as the control. The conversion of the scaffolds to HA was studied as a function of immersion time in a simulated body fluid. Histology and scanning electron microscopy were used to evaluate conversion of the bioactive glass implants to hydroxyapatite, as well as tissue ingrowth and blood vessel formation in the implants. The pore size of the scaffolds was found to have little effect on tissue infiltration and angiogenesis after the 4-week implantation.

  6. In vitro evaluation of cytotoxicity of silver-containing borate bioactive glass.

    Science.gov (United States)

    Luo, Shi-Hua; Xiao, Wei; Wei, Xiao-Juan; Jia, Wei-Tao; Zhang, Chang-Qing; Huang, Wen-Hai; Jin, Dong-Xu; Rahaman, Mohamed N; Day, Delbert E

    2010-11-01

    The cytotoxicity of silver-containing borate bioactive glass was evaluated in vitro from the response of osteoblastic and fibroblastic cells in media containing the dissolution products of the glass. Glass frits containing 0-2 weight percent (wt %) Ag were prepared by a conventional melting and quenching process. The amount of Ag dissolved from the glass into a simulated body fluid (SBF), measured using atomic emission spectroscopy, increased rapidly within the first 48 h, but slowed considerably at longer times. Structural and microchemical analysis showed that the formation of a hydroxyapatite-like layer on the glass surface within 14 days of immersion in the SBF. The response of MC3T3-E1 and L929 cells to the dissolution products of the glass was evaluated using SEM observation of cell morphology, and assays of MTT hydrolysis, lactate dehydrogenase release, and alkaline phosphatase activity after incubation for up to 48 h. Cytotoxic effects were found for the borate glass containing 2 wt % Ag, but not for 0.75 and 1 wt % Ag. This borate glass containing up to ∼1 wt % Ag could provide a coating material for bacterial inhibition and enhanced bioactivity of orthopaedic implant materials such as titanium.

  7. Dosimetric properties of dysprosium doped calcium magnesium borate glass subjected to Co-60 gamma ray

    Energy Technology Data Exchange (ETDEWEB)

    Omar, R. S., E-mail: ratnasuffhiyanni@gmail.com; Wagiran, H., E-mail: husin@utm.my; Saeed, M. A. [Department of Physics, Faculty of Science, Universiti Teknologi Malaysia, 81310 Johor Bahru (Malaysia)

    2016-01-22

    Thermoluminescence (TL) dosimetric properties of dysprosium doped calcium magnesium borate (CMB:Dy) glass are presented. This study is deemed to understand the application of calcium as the modifier in magnesium borate glass with the presence of dysprosium as the activator to be performed as TL dosimeter (TLD). The study provides fundamental knowledge of a glass system that may lead to perform new TL glass dosimetry application in future research. Calcium magnesium borate glass systems of (70-y) B{sub 2}O{sub 3} − 20 CaO – 10 MgO-(y) Dy{sub 2}O{sub 3} with 0.05  mol % ≤ y ≤ 0.7  mol % of dyprosium were prepared by melt-quenching technique. The amorphous structure and TL properties of the prepared samples were determined using powder X-ray diffraction (XRD) and TL reader; model Harshaw 4500 respectively. The samples were irradiated to Co-60 gamma source at a dose of 50 Gy. Dosimetric properties such as annealing procedure, time temperature profile (TTP) setting, optimization of Dy{sub 2}O{sub 3} concentration of 0.5 mol % were determined for thermoluminescence dosimeter (TLD) reader used.

  8. Composite structure of wood cells in petrified wood

    Energy Technology Data Exchange (ETDEWEB)

    Nowak, Jakub [Department of Chemistry, Catholic University of Lublin, 20-718 Lublin (Poland); Florek, Marek [Department of Chemistry, Catholic University of Lublin, 20-718 Lublin (Poland); Kwiatek, Wojciech [Institute of Nuclear Physics, Department of Nuclear Spectroscopy, 31-342 Cracow (Poland); Lekki, Janusz [Institute of Nuclear Physics, Department of Nuclear Spectroscopy, 31-342 Cracow (Poland); Chevallier, Pierre [LPS, CEN Saclay et LURE, Universite Paris-Sud, Bat 209D, F-91405 Orsay (France); Zieba, Emil [Department of Chemistry, Catholic University of Lublin, 20-718 Lublin (Poland); Mestres, Narcis [Institut de Ciencia de Materials de Barcelona (ICMAB), Campus de la UAB, E-08193-Bellaterra (Spain); Dutkiewicz, E.M. [Institute of Nuclear Physics, Department of Nuclear Spectroscopy, 31-342 Cracow (Poland); Kuczumow, Andrzej [Department of Chemistry, Catholic University of Lublin, 20-718 Lublin (Poland)

    2005-04-28

    Special kinds of petrified wood of complex structure were investigated. All the samples were composed of at least two different inorganic substances. The original cell structure was preserved in each case. The remnants of the original biological material were detected in some locations, especially in the cell walls. The complex inorganic structure was superimposed on the remnant organic network. The first inorganic component was located in the lumena (l.) of the cells while another one in the walls (w.) of the cells. The investigated arrangements were as follows: calcite (l.)-goethite-hematite (w.)-wood from Dunarobba, Italy; pyrite (l.)-calcite (w.)-wood from Lukow, Poland; goethite (l.)-silica (w.)-wood from Kwaczala, Poland. The inorganic composition was analysed and spatially located by the use of three spectral methods: electron microprobe, X-ray synchrotron-based microprobe, {mu}-PIXE microprobe. The accurate mappings presenting 2D distribution of the chemical species were presented for each case. Trace elements were detected and correlated with the distribution of the main elements. In addition, the identification of phases was done by the use of {mu}-Raman and {mu}-XRD techniques for selected and representative points. The possible mechanisms of the described arrangements are considered. The potential synthesis of similar structures and their possible applications are suggested.

  9. Military Retention. A Comparative Outlook

    Directory of Open Access Journals (Sweden)

    Vasile Sminchise

    2016-06-01

    Full Text Available One of the main goals for human resources management structures and for armed forces leaders is to maintain all necessary personnel, both qualitatively and quantitatively for operational needs or for full required capabilities. The retention of military personnel is essential to keep morale and unit readiness and to reduce the costs for recruiting, training, replacement of manpower. Retention rates depend not only on money or other social measures. The goal for retention is to keep in use the most valuable resource that belongs to an organization: the human beings and their knowledge. The aim pf this paper is to provide a comparative analysis of retention measures in various countries based on Research and Technology Organisation report released in 2007 and, thus, provide more examples of retention measures as far as the Romanian military system is concerned.

  10. Comparative wood anatomy of Rhodothamnus species

    OpenAIRE

    SERDAR, Bedri

    2014-01-01

    In this study, the comparative wood anatomy of the European [Rhodothamnus chamaecistus (L.) Reichb.] and Anatolian (Rhodothamnus sessilifolius P.H.Davis) species of Rhodothamnus were studied. The wood anatomy of the taxa shows evidence of adaptation to growing in alpine habitats. The woods of the species exhibit primitive wood anatomical characteristics and share similar qualitative anatomical features. However, some of the quantitative anatomical characteristics of the taxa show significant ...

  11. Sustainable wood waste management in Nigeria

    Directory of Open Access Journals (Sweden)

    Owoyemi Jacob Mayowa

    2016-09-01

    Full Text Available Wood industries produce large volumes of residues which must be utilized, marketed or properly disposed of. Heaps of wood residues are common features in wood industries throughout the year. In Nigeria, this residue is generally regarded as waste and this has led to open burning practices, dumping in water bodies or dumping in an open area which constitutes environmental pollution. Sawmills in Nigeria generated over 1,000,000 m3 of wood waste in 2010 while about 5000 m3 of waste was generated in plywood mills. Nigeria generates about 1.8 million tons of sawdust annually and 5.2 million tons of wood wastes. The impact of improper disposal of waste wood on the environment affects both the aquatic and terrestrial ecosystems. Also burning of waste wood releases greenhouse gases into the atmosphere causing various health issues. Reuse/recycling of these wood residues in Nigeria will reduce the pressure on our ever decreasing forests, reduce environmental pollution, create wealth and employment. The literature available on this subject was reviewed and this article, therefore, focuses on the various methods of wood waste disposal and its utilization in Nigerian wood industries, the effects of wood waste on the environment as well as on human health and the benefits of proper wood waste management practices.

  12. WOOD COLOR CHANGES BY AMMONIA FUMING

    Directory of Open Access Journals (Sweden)

    Josip Miklečić,

    2012-06-01

    Full Text Available This paper studies the influence of ammonia gas on wood color changes in response to an increasing demand for dark colored wood specimens. The darker wood color in ammonia fuming is accomplished through chemical reactions between ammonia gas and wood compounds. We exposed oak, maple, spruce, and larch wood samples to ammonia gas for 16 days. During fuming, the color changes were studied using CIE L*a*b* parameters. After fuming, the changes in extractives content, tannin, and nitrogen content were analyzed. The chemical changes of wood and residues of wood extractives after fuming were analyzed by FTIR spectroscopy. Oak wood reacted intensively with ammonia gas in a very short time, and the darkening was prominent for all the investigated wood species. It was established that tannin had no major influence on color changes of maple and larch wood in the ammonia-fuming process. The FTIR spectra of fumed wood indicated involvement of carbonyl groups, and the FTIR spectra of wood extractives indicated involvement of carbonyl, aromatic, and alcohol groups in reaction with ammonia gas.

  13. Mechanical Behaviour of the Wood Masonry

    Directory of Open Access Journals (Sweden)

    Fazia FOUCHAL

    2011-09-01

    Full Text Available In this paper we study the walls wood masonry behaviour. First, we propose a regulatory validation of the walls wood masonry behaviour subjected to vertical and horizontal loads according to Eurocode 5. Then we present the numerical application on the wall wood supported two floors level.

  14. Durability of the reaction to fire performance for fire retardant treated (FRT wood products in exterior applications – a ten years report

    Directory of Open Access Journals (Sweden)

    Östman Birgit

    2016-01-01

    Full Text Available Several long term experimental studies on the maintained reaction to fire performance of fire retardant treated (FRT wood products over time are presented. They are performed according to a European system based on earlier Nordic and North American systems and include accelerated ageing according to different procedures and natural weathering up to ten years. Main conclusions are: The hygroscopic properties are unchanged compared to untreated wood for most FRT wood products used commercially. The reaction to fire properties of FRT wood may be maintained after accelerated and natural ageing if the retention levels are high enough, but several FRT wood products loose most of their improved reaction to fire properties during weathering. Paint systems contribute considerably to maintain of the fire performance at exterior application and are usually needed to maintain the fire performance after weathering.

  15. Body of Wood

    Directory of Open Access Journals (Sweden)

    Pierre Michon

    2014-12-01

    not only a defrocked friar with the guys or on the street; he donned the silk babouches when he went home too. He dispossessed himself of the Seine that rolled on before his eyes; the small girl who lived on her feet, whom he puts to death in all his books, he hardly saw her; the loveliest girls of his day, the finest too for sure, who wanted him, so that he happened to come – he dispossessed himself of them, whether he came or opted to come no more, which amounted to the same thing; no apples from Norman orchards, no trees deep in the woods, no unlaced Louise Colet, no lilies, no young laughter, no Louise Colet weeping at his door, he kissed it all off, laughed over it and kissed it off, cried about it and kissed it off, he was not there. In fact he had nothing, he was deprived of everything, since it was in his head.

  16. Mathematical Simulation of Temperature Profiles within Microwave Heated Wood Made for Wood-Based Nanocomposites

    OpenAIRE

    Xianjun Li; Yongfeng Luo; Hongbin Chen; Xia He; Jianxiong Lv; Yiqiang Wu

    2013-01-01

    High intensive microwave pretreatment is a new method to modify wood for the fabrication of wood-based nanocomposites. Based on the physical law on heat transfer, a mathematical model to describe the temperature profiles within wood heated by high intensive microwave was established and simulated in this research. The results showed that the temperature profiles within wood were related to microwave heating methods; The temperature inside wood firstly increased and then gradually decreased al...

  17. IMPACT OF THE EU TIMBER REGULATION ON RUSSIAN COMPANIES EXPORTING WOOD AND WOOD-BASED PRODUCTS

    OpenAIRE

    NESHATAEVA ELENA V.; KARJALAINEN TIMO

    2015-01-01

    The problem of illegal logging forced EU, which is one of the major consumers of wood in the world, to develop legislation aimed at termination of supplies of illegally harvested wood and wood-based products into EU. EU Timber Regulation №995 is applicable for any company placing wood or wood-based products on the EU market. Russia ranks first in illegally harvested timber export into EU markets, therefore EU Timber Regulation should influence substantially on Russian companies. Possible infl...

  18. Wood Microstructure Effects on Chinese White Poplar Dyeing

    Institute of Scientific and Technical Information of China (English)

    DUANXinfang; BAOFucheng

    2004-01-01

    In order to study the influence of wood microstructure on wood dyeing, eleven parameters of wood microstructure and 5 parameters of wood dyeing effects for 34 pieces of wood boards from 5 trees of Chinese white poplar (Populus tornentosa) were determined and the multiple regression analysis between the factors of wood microstructures and the parameters of wood dyeing effects were made. The regression results show that each variable of wood dyeing effects has higher relationship with wood microstructures,and multiple correlation coefficients between each variable of wood dyeing effects and wood microstructures are 0.483 6-0.799 8. The main factors of wood microstructures influencing wood dyeing of Chinese whitep oplar are proportion of wood ray, proportion of vessel and proportion of wood fiber according to comparing the standardized regression coefficients of multiple regression equation.

  19. Calibration of the borated ion chamber at NIST reactor thermal column.

    Science.gov (United States)

    Wang, Z; Hertel, N E; Lennox, A

    2007-01-01

    In boron neutron capture therapy and boron neutron capture enhanced fast neutron therapy, the absorbed dose of tissue due to the boron neutron capture reaction is difficult to measure directly. This dose can be computed from the measured thermal neutron fluence rate and the (10)B concentration at the site of interest. A borated tissue-equivalent (TE) ion chamber can be used to directly measure the boron dose in a phantom under irradiation by a neutron beam. Fermilab has two Exradin 0.5 cm(3) Spokas thimble TE ion chambers, one loaded with boron, available for such measurements. At the Fermilab Neutron Therapy Facility, these ion chambers are generally used with air as the filling gas. Since alpha particles and lithium ions from the (10)B(n,alpha)(7)Li reactions have very short ranges in air, the Bragg-Gray principle may not be satisfied for the borated TE ion chamber. A calibration method is described in this paper for the determination of boron capture dose using paired ion chambers. The two TE ion chambers were calibrated in the thermal column of the National Institute of Standards and Technology (NIST) research reactor. The borated TE ion chamber is loaded with 1,000 ppm of natural boron (184 ppm of (10)B). The NIST thermal column has a cadmium ratio of greater than 400 as determined by gold activation. The thermal neutron fluence rate during the calibration was determined using a NIST fission chamber to an accuracy of 5.1%. The chambers were calibrated at two different thermal neutron fluence rates: 5.11 x 10(6) and 4.46 x 10(7)n cm(-2) s(-1). The non-borated ion chamber reading was used to subtract collected charge not due to boron neutron capture reactions. An optically thick lithium slab was used to attenuate the thermal neutrons from the neutron beam port so the responses of the chambers could be corrected for fast neutrons and gamma rays in the beam. The calibration factor of the borated ion chamber was determined to be 1.83 x 10(9) +/- 5.5% (+/- 1sigma) n

  20. Wood stoves: the trendy pollutant

    Energy Technology Data Exchange (ETDEWEB)

    Allaby, M.; Lovelock, J.

    1980-11-13

    The wood-burning stove is being increasingly accepted as an alternative to costly and scarce heating fuels. These stoves, however, contribute significantly to air pollution. The more efficient the stove, the more pollutants it releases. Carbon monoxide and hydrocarbons are the primary offenders. Increasing use of these stoves may also exhaust timber and forest resources. (3 drawings, 2 photos)

  1. Wood anatomy of the Combretaceae

    NARCIS (Netherlands)

    Vliet, van G.J.C.M.

    1979-01-01

    The wood anatomy of all genera of the Combretaceae (Meiostemon excepted) is described in detail on the basis of 120 samples representing 90 species from 19 genera. Additional data from the literature are added. The structural variation of the vestured pits is described and classified. There are two

  2. Non-malignant respiratory diseases and occupational exposure to wood dust. Part I. Fresh wood and mixed wood industry.

    Science.gov (United States)

    Jacobsen, Gitte; Schaumburg, Inger; Sigsgaard, Torben; Schlunssen, Vivi

    2010-01-01

    This paper reviews associations in literature between exposure to wood dust from fresh wood and non-malignant respiratory diseases. Criteria for inclusion are epidemiological studies in English language journals with an internal or external control group describing relationships between wood dust exposure and respiratory diseases or symptoms. The papers took into account smoking, and when dealing with lung function took age into consideration. A total of 25 papers concerning exposure to fresh wood and mixed wood formed the basis of this review. The results support an association between fresh wood dust exposure and asthma, asthma symptoms, coughing, bronchitis, and acute and chronic impairment of lung function. In addition, an association between fresh wood dust exposure and rhino-conjunctivitis was seen across studies. Apart from plicatic acid in western red cedar wood, no causal agent was consistently disclosed. Type 1 allergy is not suspected of being a major cause of wood dust induced asthma. Concurrent exposure to microorganisms and terpenes probably add to the inherent risk of wood dust exposure in the fresh wood industry.

  3. Kinetic investigation of wood pyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Thurner, F.; Mann, U.; Beck, S. R.

    1980-06-01

    The objective of this investigation was to determine the kinetics of the primary reactions of wood pyrolysis. A new experimental method was developed which enabled us to measure the rate of gas, tar, and char production while taking into account the temperature variations during the wood heating up. The experimental method developed did not require any sophisticated instruments. It facilitated the collection of gas, tar and residue (unreacted wood and char) as well as accurate measurement of the temperature inside the wood sample. Expressions relating the kinetic parameters to the measured variables were derived. The pyrolysis kinetics was investigated in the range of 300 to 400/sup 0/C at atmospheric pressure and under nitrogen atmosphere. Reaction temperature and mass fractions of gas, tar, and residue were measured as a function of time. Assuming first-order reactions, the kinetic parameters were determined using differential method. The measured activation energies of wood pyrolysis to gas, tar, and char were 88.6, 112.7, and 106.5 kJ/mole, respectively. These kinetic data were then used to predict the yield of the various pyrolysis products. It was found that the best prediction was obtained when an integral-mean temperature obtained from the temperature-time curve was used as reaction temperature. The pyrolysis products were analyzed to investigate the influence of the pyrolysis conditions on the composition. The gas consisted mainly of carbon dioxide, carbon monoxide, oxygen, and C/sub 3//sup +/-compounds. The gas composition depended on reaction time as well as reactor temperature. The tar analysis indicated that the tar consisted of about seven compounds. Its major compound was believed to be levoglucosan. Elemental analysis for the char showed that the carbon content increased with increasing temperature.

  4. Retention in orthodontics.

    Science.gov (United States)

    Johnston, C D; Littlewood, S J

    2015-02-16

    Retention is necessary following orthodontic treatment to prevent relapse of the final occlusal outcome. Relapse can occur as a result of forces from the periodontal fibres around the teeth which tend to pull the teeth back towards their pre-treatment positions, and also from deflecting occlusal contacts if the final occlusion is less than ideal. Age changes, in the form of ongoing dentofacial growth, as well as changes in the surrounding soft tissues, can also affect the stability of the orthodontic outcome. It is therefore essential that orthodontists, patients and their general dental practitioners understand the importance of wearing retainers after orthodontic treatment. This article will update the reader on the different types of removable and fixed retainers, including their indications, duration of wear, and how they should be managed in order to minimise any unwanted effects on oral health and orthodontic outcomes. The key roles that the general dental practitioner can play in supporting their patients wearing orthodontic retainers are also emphasised.

  5. Biosynthesis and biodegradation of wood components

    Energy Technology Data Exchange (ETDEWEB)

    Higuchi, T. (ed.)

    1985-01-01

    A textbook containing 22 chapters by various authors covers the structure of wood, the localization of polysaccharides and lignins in wood cell walls, metabolism and synthetic function of cambial tissue, cell organelles and their function in the biosynthesis of cell wall components, biosynthesis of plant cell wall polysaccharides, lignin, cutin, suberin and associated waxes, phenolic acids and monolignols, quinones, flavonoids, tannins, stilbenes and terpenoid wood extractives, the occurrence of extractives, the metabolism of phenolic acids, wood degradation by micro-organisms and fungi, and biodegradation of cellulose, hemicelluloses, lignin, and aromatic extractives of wood. An index is included.

  6. Utilization of Soft Wood Wastes as a Feed Stock to Produce Fuel Ethanol

    Directory of Open Access Journals (Sweden)

    Adnan M. Khalil

    2009-01-01

    Full Text Available Problem statement: The current research investigated the utilization of soft wood waste as a feedstock to produce a value-added product-fuel ethanol. Approach: The main issue in converting soft wood waste to fuel ethanol is the accessibility of the polysaccharides for breaking down into monosaccharides. This study focused on the use of steam as the pretreatment method. The governing factors for the effectiveness of steam pretreatment are steam temperature and retention times. Following steam pretreatment, soft wood waste was subjected to acid hydrolysis. The sugars released by acid hydrolysis were fermented in series chemical reactions that convert sugars to ethanol. The fermentation reaction was caused by yeast, which feed on the sugars. Results: Steam pretreatment was able to improve both glucose yields from acid hydrolysis and ethanol yields from fermentation. The results obtained from this study showed that steam pretreated soft wood waste are a heterogeneous material. So biomass goes through a size-reduction step to make it easier to handle and to make the ethanol production process more efficient. Steam treatment on soft wood waste increased the hydrolysis of cellulose by acid hydrolysis. Following 24 h of diluted or concentrated acid hydrolysis, a maximum cellulose conversion of 20.5% was obtained. Similarly, sugars to ethanol conversions were improved by steam treatment. Maximum sugar to ethanol conversion of 40.7% was observed. Conclusion: It was recommended that the hydrolysis process be done for 40 min to obtain the maximum sugars yield in a reasonable period of time.

  7. [Wood dust as inhalative noxious agent].

    Science.gov (United States)

    Kirsten, D; Liebetrau, G; Meister, W

    1985-01-01

    Wood dust is known as a cause of asthma and chronic bronchitis. From 1979 to 1983 we observed 115 patients with chronic lung diseases, who were exposed to wood dust during many years. We found an irritative pathogenesis in 101 patients with asthma or bronchitis. Twenty nine patients had got a positive skin test, especially with makoré, beech, koto, ash, pine. The inhalation test was positive in 7 of them. The occupational etiology was verified in 5 patients. Besides wood dust itself chemicals for wood protection or wood adhesives can have importance in the pathogenesis of these diseases. Fourteen patients had got alveolitis or lung fibrosis after wood-dust exposition. In each case we found precipitating antibodies against moulds, which could be cultivated from wood dust to which the patients were exposed.

  8. Lung function in Pakistani wood workers.

    Science.gov (United States)

    Meo, Sultan A

    2006-06-01

    The lung function impairment is the most common respiratory problem in industrial plants and their vicinity. Therefore, the purpose was to study the affects of wood dust and its duration of exposure on lung function. This was a matched cross-sectional study of Spirometry in 46 non-smoking wood workers with age range 20 - 60 years, who worked without the benefit of wood dust control ventilation or respiratory protective devices. Pulmonary function test was performed by using an electronic Spirometer. Significant reduction was observed in the mean values of Forced Vital Capacity (FVC), Forced Expiratory Volume in one second (FEV1), and Maximum Voluntary Ventilation (MVV) in wood workers relative to their matched controls. This impairment was increased with the duration of exposure to wood industries. It is concluded that lung function in wood workers is impaired and stratification of results shows a dose-response effect of years of wood dust exposure on lung function.

  9. Post-operative urinary retention.

    Science.gov (United States)

    Steggall, Martin; Treacy, Colm; Jones, Mark

    Urinary retention is a common complication of surgery and anaesthesia. The risk of post-operative urinary retention is increased following certain surgical procedures and anaesthetic modalities, and with patients' advancing age. Patients at increased risk of post-operative urinary retention should be identified before surgery or the condition should be identified and treated in a timely manner following surgery. If conservative measures do not help the patient to pass urine, the bladder will need to be drained using either an intermittent catheter or an indwelling urethral catheter, which can result in catheter-associated urinary tract infections. This article provides an overview of normal bladder function, risk factors for developing post-operative urinary retention, and treatment options. Guidance drawn from the literature aims to assist nurses in identifying at-risk patients and inform patient care.

  10. Turnover: strategies for staff retention.

    Science.gov (United States)

    SnowAntle, S

    1990-01-01

    This discussion has focused on a number of areas where organizations may find opportunities for more effectively managing employee retention. Given the multitude of causes and consequences, there is no one quick fix. Effective management of employee retention requires assessment of the entire human resources process, that is, recruitment, selection, job design, compensation, supervision, work conditions, etc. Regular and systematic diagnosis of turnover and implementation of multiple strategies and evaluation are needed (Mobley, 1982).

  11. Model for reaction kinetics in pyrolysis of wood

    Energy Technology Data Exchange (ETDEWEB)

    Ahuja, P.; Singh, P.C.; Upadhyay, S.N.; Kumar, S. [Banaras Hindu Univ., Varanasi (India)

    1996-12-31

    A reaction model for the pyrolysis of small and large particles of wood Is developed. The chemical reactions that take place when biomass is pyrolyzed are the devolatilization reactions (primary) and due to the vapour-solid interactions (secondary). In the case of small particles, when the volatiles are immediately removed by the purge gas, only primary reactions occur and the reaction model is described by weight loss and char forming reactions. The of heterogeneous secondary reactions occur in the case of large particles due to the interaction between the volatiles and the hot nascent primary char. A chain reaction mechanism of secondary char formation is proposed. The model takes both the volatiles retention time and cracking and repolymerization reactions of the vapours with the decomposing solid as well as autocatalysis into consideration. 7 refs., 3 figs., 2 tabs.

  12. Model for reaction kinetics in pyrolysis of wood

    Energy Technology Data Exchange (ETDEWEB)

    Ahuja, P.; Singh, P.C.; Upadhyay, S.N.; Kuma, S. [Banaras Hindu Univ., Varanasi (India)

    1996-12-31

    A reaction model for the pyrolysis of small and large particles of wood is developed. The chemical reactions that take place when biomass is pyrolyzed are the devolatilization reactions (primary) and due to the vapour-solid interactions (secondary). In the case of small particles, when the volatiles are immediately removed by the purge gas, only primary reactions occur and the reaction model is described by weight loss and char forming reactions. The heterogeneous secondary reactions occur in the case of large particles due to the interaction between the volatiles and the hot nascent primary char. A chain reaction mechanism of secondary char formation is proposed. The model takes both the volatiles retention time and cracking and repolymerization reactions of the vapours with the decomposing solid as well as autocatalysis into consideration. 6 refs., 3 figs., 2 tabs.

  13. HP-CsB5O8 : synthesis and characterization of an outstanding borate exhibiting the simultaneous linkage of all structural units of borates.

    Science.gov (United States)

    Sohr, Gerhard; Többens, Daniel M; Schmedt Auf der Günne, Jörn; Huppertz, Hubert

    2014-12-15

    The new cesium pentaborate HP-CsB5 O8 is synthesized under high-pressure/high-temperature conditions of 6 GPa and 900 °C in a Walker-type multianvil apparatus. The compound crystallizes in the orthorhombic space group Pnma (Z=4) with the parameters a=789.7(1), b=961.2(1), c=836.3(1) pm, V=0.6348(1) nm(3) , R1 =0.0359 and wR2 =0.0440 (all data). The new structure type of HP-CsB5 O8 exhibits the simultaneous linkage of trigonal BO3 groups, corner-sharing BO4 tetrahedra, and edge-sharing BO4 tetrahedra including the presence of threefold-coordinated oxygen atoms. With respect to the rich structural chemistry of borates, HP-CsB5 O8 is the second structure type possessing this outstanding combination of the main structural units of borates in one compound. The structure consists of corrugated chains of corner- and edge-sharing BO4 tetrahedra interconnected through BO3 groups forming octagonal channels. Inside these channels, cesium is 13+3-fold coordinated by oxygen atoms. (11) B MQMAS NMR spectra are analyzed to estimate the isotropic chemical shift values and quadrupolar parameters. IR and Raman spectra are obtained and compared to the calculated vibrational frequencies at the Γ-point. The high-temperature behavior is examined by means of temperature-programmed powder diffraction.

  14. Combustion of furniture wood waste and solid wood: Kinetic study and evolution of pollutants

    OpenAIRE

    Moreno Caballero, Ana Isabel; Font Montesinos, Rafael; Conesa, Juan A.

    2017-01-01

    This work is focused on the combustion processes of wood waste. Two kinds of waste have been studied: furniture wood waste (treated and used wood) and solid wood from factories (untreated wood). A kinetic study has been carried out for each material in air and an N2:O2 9:1 atmosphere with dynamic and dynamic + isothermal runs at different heating rates, considering the decomposition of the three main components of the wood and also the combustion of the char obtained. Satisfactory kinetic mod...

  15. Wood-burning stoves worldwide

    DEFF Research Database (Denmark)

    Luis Teles de Carvalho, Ricardo

    global environmental health risk, since these sources are important contributors to fine particulate matter (PM2.5) in the ambient air that increase climate and health risks. This thesis explores the social-technical dimensions of both the use of wood-burning stoves (WBSs) and transition to the use...... focused on understanding the effects of cookstove use on the indoor air quality of 20 rural houses. In Europe, qualitative interviews were conducted to study the operation of WBSs in 24 dwellings. The energy and environmental performance of a fireplace, an ordinary wood stove and an automatic stove, were......, the advanced gasifiers and automatic stoves (Digital and Forced air) were identified to be among the best performing technologies. In spite of the fact that the thermal efficiency of the most advanced type of heating stoves (Gasifier) is around twice larger than that achieved for the most advanced type...

  16. Investigations on the passivity of iron in borate and phosphate buffers, pH 8.4

    Energy Technology Data Exchange (ETDEWEB)

    Sieber, I.V. [University of Erlangen-Nuremberg, Department of Materials Science, Chair for Surface Science and Corrosion, D-91058 Erlangen (Germany)]. E-mail: irina.sieber@ww.uni-erlangen.de; Hildebrand, H. [University of Erlangen-Nuremberg, Department of Materials Science, Chair for Surface Science and Corrosion, D-91058 Erlangen (Germany); Virtanen, S. [University of Erlangen-Nuremberg, Department of Materials Science, Chair for Surface Science and Corrosion, D-91058 Erlangen (Germany); Schmuki, P. [University of Erlangen-Nuremberg, Department of Materials Science, Chair for Surface Science and Corrosion, D-91058 Erlangen (Germany)

    2006-11-15

    In the present work surface analytical experiments (XPS and AES) on the passive film on iron formed in borate and phosphate buffers (pH 8.4) have been carried out. In the passive film formed in phosphate buffer a significant amount of phosphates is found in the outer part of the film. Boron species are not significantly incorporated in the passive film formed in borate buffer. The mechanism of the reduction of the passive film depends strongly on the electrolyte composition. In borate buffer, cathodic polarization leads to reductive dissolution of the passive film whereas in phosphate buffer the passive film is converted into metallic iron without dissolution but via laterally inhomogeneously formation of an intermediate Fe(II) phosphate layer.

  17. International Transmission Under Bretton Woods

    OpenAIRE

    Alan C. Stockman

    1992-01-01

    This paper explores the main channels of international transmission of economic disturbances under the Bretton Woods System and presents evidence on the short-run international transmission of inflation under that system. There appears to have been little short-run international transmission of inflation. Countries with one-percent higher money-growth rates subsequently had one-fourth to one-half percent higher inflation and a (predictably) lower real interest rate. This probably reflects eff...

  18. WOOD BIOMASS FOR ENERGY IN MONTENEGRO

    Directory of Open Access Journals (Sweden)

    Gradimir Danon

    2010-01-01

    Full Text Available Wood biomass has got its place in the energy balance of Montenegro. A little more than 6% of the total energy consumption is obtained by burning wood. Along with the appropriate state measures, it is economically and environmentally justified to expect Montenegro to more than double the utilization of the existing renewable energy sources including wood biomass, in the near future. For the purpose of achieving this goal, ‘Commercial Utilisation of the Wood Residue as a Resource for Economic Development in the North of Montenegro' project was carried out in 2007. The results of this project were included in the plan of the necessary interventions of the Government and its Agencies, associations or clusters, non-government organisations and interested enterprises. The plan was made on the basis of the wood residue at disposal and the attitude of individual subjects to produce and/or use solid bio-fuels and consists of a proposal of collection and utilisation of the wood residue for each individual district in the north of Montenegro. The basic factors of sustainability of future commercialisation of the wood residue were: availability of the wood raw material, and thereby the wood residue; the development of wood-based fuel markets, and the size of the profit.

  19. Discover the benefits of residential wood heating

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2003-07-01

    This publication described how residential wood-heating systems are being used to reduce energy costs and increase home comfort. Biomass energy refers to all forms are renewable energy that is derived from plant materials. The source of fuel may include sawmills, woodworking shops, forest operations and farms. The combustion of biomass is also considered to be carbon dioxide neutral, and is not considered to be a major producer of greenhouse gases (GHG) linked to global climate change. Wood burning does, however, release air pollutants, particularly if they are incompletely burned. Incomplete combustion of wood results in dense smoke consisting of toxic gases. Natural Resources Canada helped create new safety standards and the development of the Wood Energy Technical Training Program to ensure that all types of wood-burning appliances are installed correctly and safely to reduce the risk of fire and for effective wood heating. In Canada, more than 3 million families heat with wood as a primary or secondary heating source in homes and cottages. Wood heating offers security from energy price fluctuations and electrical power failures. This paper described the benefits of fireplace inserts that can transform old fireplaces into modern heating systems. It also demonstrated how an add-on wood furnace can be installed next to oil furnaces to convert an oil-only heating system to a wood-oil combination system, thereby saving thousands of dollars in heating costs. Wood pellet stoves are another wood burning option. The fuel for the stoves is produced from dried, finely ground wood waste that is compressed into hard pellets that are loaded into a hopper. The stove can run automatically for up to 24 hours. New high-efficiency advanced fireplaces also offer an alternative heating system that can reduce heating costs while preserving Canada's limited supply of fossil fuels such as oil and gas. 13 figs.

  20. Nonisothermal moisture movement in wood

    Institute of Scientific and Technical Information of China (English)

    LI Xianjun; ZHANG Biguang; LI Wenjun; LI Yanjun

    2006-01-01

    In order to analyze the effect of temperature gradient on moisture movement during highly intensive drying,such as microwave-vacuum drying,the profile of the temperature and moisture content in sealed wood whose opposite faces were subjected to temperature gradient for a short time was measured.The ratio of the moisture content (MC) gradient to the temperature gradient (dM/dT) was calculated and the factors influencing moisture movement under nonisothermal conditions were discussed.The results indicate that moisture moved in wood from the warm surface to the cold one even if opposite faces of the sealed wood assembly were exposed continuously to different but constant temperatures for a short period.The moisture content on the cold surface was higher than that on the warm surface.The moisture content gradient opposite to the temperature gradient was established,and the dM/dT was below 0.9%/℃.The temperature in the sample and the distance from the hot surface of the sample was strongly linearly correlated.With an increase in temperature,initial moisture content and experimental time,the dM/dT was significantly increased.

  1. Tension wood and opposite wood in 21 tropical rain forest species. 1. Occurence and efficiency of G-layer

    OpenAIRE

    Clair, Bruno; Ruelle, Julien; Beauchêne, Jacques; Prévost, Marie-Françoise; Fournier, Meriem

    2006-01-01

    Wood samples were taken from the upper and lower sides of 21 naturally tilted trees from 18 families of angiosperms in the tropical rainforest in French Guyana. The measurement of growth stresses ensured that the two samples were taken from wood tissues in a different mechanical state: highly tensile stressed wood on the upper side, called tension wood and lower tensile stressed wood on the lower side, called opposite wood. Eight species had tension wood fibres with a distinct gelatinous laye...

  2. Energy transfer and luminescence studies of Pr 3+ , Yb 3+ co-doped lead borate glass

    Science.gov (United States)

    Wen, Hongli; Tanner, Peter A.

    2011-09-01

    Lead borate glass samples doped with the tripositive lanthanide ions Pr 3+ and Yb 3+ were synthesized by the conventional melting-quenching method. The luminescence properties and energy transfer process from Pr 3+ to Yb 3+ were investigated. Upon ultraviolet excitation, the room temperature luminescence decay curve of a sample containing only a low concentration of Pr 3+ exhibited monoexponential decay from 1D 2 with the lifetime 37 μs, without emission from 3P 0. The room temperature Pr 3+ emission intensity decreased with the increase of Yb 3+ mole ratio in the glass. Under the excitation of 454.5 nm at 10 K, a broad red emission band centered at 605 nm, and an NIR emission band at 995 nm were observed in the co-doped lead borate glass, originating from Pr 3+ and Yb 3+ ions, respectively. The decay curves of the 1D 2 emission from Pr 3+ with addition of Yb 3+ in lead borate glass show non-monoexponential character, and are best described by a stretched exponential function. The average 1D 2 decay time decreases considerably with the addition of Yb 3+ in the glass. Decay curve fitting using a modified Inokuti-Hirayama expression indicates dipole-dipole energy transfer from Pr 3+ to Yb 3+, which is consistent with the expected cross-relaxation scheme. There is a good agreement of the estimated overall energy transfer efficiency obtained from the integrals under the normalized decay curves, or from the lifetimes fitted by the stretched exponential function, or from the average decay times.

  3. Compositional dependence of optical band gap and refractive index in lead and bismuth borate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Mallur, Saisudha B.; Czarnecki, Tyler; Adhikari, Ashish; Babu, Panakkattu K.

    2015-08-15

    Highlights: • Refractive indices increase with increasing PbO/Bi{sub 2}O{sub 3} content. • Optical band gap arises due to direct forbidden transition. • Optical band gaps decrease with increasing PbO/Bi{sub 2}O{sub 3} content. • New empirical relation between the optical band gap and the refractive index. - Abstract: We prepared a series of lead and bismuth borate glasses by varying PbO/Bi{sub 2}O{sub 3} content and studied refractive index and optical band gap as a function of glass composition. Refractive indices were measured very accurately using a Brewster’s angle set up while the optical band gaps were determined by analyzing the optical absorption edge using the Mott–Davis model. Using the Lorentz–Lorentz method and the effective medium theory, we calculated the refractive indices and then compared them with the measured values. Bismuth borate glasses show better agreement between the calculated values of the refractive index and experimental values. We used a differential method based on Mott–Davis model to obtain the type of transition and optical band gap (E{sub opt}) which in turn was compared with the value of E{sub opt} obtained using the extinction coefficient. Our analysis shows that in both lead and bismuth borate glasses, the optical band gap arises due to direct forbidden transition. With increasing PbO/Bi{sub 2}O{sub 3} content, the absorption edge shifts toward longer wavelengths and the optical band gap decreases. This behavior can be explained in terms of changes to the Pb−O/Bi−O chemical bonds with glass composition. We obtained a new empirical relation between the optical band gap and the refractive index which can be used to accurately determine the electronic oxide polarizability in lead and bismuth oxide glasses.

  4. Gamma rays interactions with WO{sub 3}-doped lead borate glasses

    Energy Technology Data Exchange (ETDEWEB)

    ElBatal, H.A. [Glass Research Department, National Research Center, Dokki, Cairo (Egypt); Abdelghany, A.M., E-mail: a.m_abdelghany@yahoo.com [Spectroscopy Department, Physics Division, National Research Center, Dokki, Cairo (Egypt); ElBatal, F.H. [Glass Research Department, National Research Center, Dokki, Cairo (Egypt); EzzElDin, F.M. [National Center for Radiation Research and Technology, Nasr City, Cairo (Egypt)

    2012-05-15

    Highlights: Black-Right-Pointing-Pointer Some ternary borate glasses of varying compositions were prepared. Black-Right-Pointing-Pointer Effect of successive gamma ray irradiation in prepared glass structure was studied. Black-Right-Pointing-Pointer FTIR, UV measurement before and after successive gamma irradiation were studied. Black-Right-Pointing-Pointer UV spectra reveal some changes with different gamma doses, which are discussed. - Abstract: Optical and FT infrared spectral properties of tungsten ions in a host lead borate glass with composition PbO 55%, B{sub 2}O{sub 3} 45% (wt%) were studied. The same spectral properties were re-measured after subjecting the samples to successive gamma irradiation. The work was undertaken to justify the state of tungsten ions in such glass system by combined spectral investigations. Optical and FTIR spectral studies were confirmed by investigating electron spin resonance (ESR) of the undoped and WO{sub 3}-doped samples before and after gamma irradiation. The optical spectrum of the undoped glass exhibits strong and wide UV absorption bands, which are related to the combined UV spectra of trace iron impurities (Fe{sup 3+} ions) and that from divalent lead (Pb{sup 2+}) ions. Optical studies of WO{sub 3}-doped sample indicate the presence of tungsten ions mostly in the hexavalent W{sup 6+} state. The presence of tungsten ions as structural groups was obtained by comparing the FTIR spectra of the undoped and WO{sub 3}-doped samples. ESR spectra confirm the optical and FTIR spectral studies. The studied host lead borate glass has been found to show obvious shielding behavior towards successive gamma irradiation as revealed by the constancy of optical absorption spectral curves.

  5. Thermal Stress-Induced Birefringence in Borate Glass Irradiated by Femtosecond Laser Pulses

    Institute of Scientific and Technical Information of China (English)

    DAI Ye; YU Bing-Kun; LU Bo; QIU Jian-Rong; YAN Xiao-Na; JIANG Xiong-Wei; ZHU Cong-Shan

    2005-01-01

    @@ Thermal stress-induced birefringence in borate glass which has been irradiated by 800-nm femtosecond laser pulses is observed under cross-polarized light. Due to the high temperature and pressure formed in the focal volume, the material at the edge of the micro-modified region is compressed between the expanding region and the unheated one, then stress emerges. Raman spectroscopy is used to investigate the stress distribution in the micro-modified region and indicates the redistributions of density and refractive index by Raman peak shift. We suggest that this technique can develop waveguide polarizers and Fresnel zone plates in integrated optics.

  6. Structural, optical and glass transition studies on Nd{sup 3+}-doped lead bismuth borate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Karthikeyan, B.; Mohan, S

    2003-07-01

    Nd{sup 3+}-doped lead bismuth borate (PbO-Bi{sub 2}O{sub 3}-B{sub 2}O{sub 3}) glasses were prepared with different concentrations of Nd{sup 3+}. The structural studies were done through FTIR spectral analysis. The glass transition studies were done through differential scanning calorimetry. The optical analysis was done by using Judd-Ofelt theory. The structural study reveals that the glass has [BiO{sub 3}], BO{sub 4}, BO{sub 3} and PbO{sub 4} units as the local structures.

  7. Absorption of light by lead silicate borate glasses containing gadolinium tellurite

    Energy Technology Data Exchange (ETDEWEB)

    Ivanchenko, L.A.; Obolonchik, V.A.; Ovcharenko, N.V.; Frankfurt, V.M.; Serdyuk, V.A.; Zaletilo, L.S.

    1987-03-01

    The authors investigate how the properties of lead silicate borate glasses change when rare-earth tellurites are added to them. The choice of glasses based on PbO was prompted by the fact that they are low-melting and will dissolve large amounts of compounds of type Ln/sub 2/Te/sub 3/O/sub 9/. The compositions of the resultant glasses are shown. The refractive indices and absorption edge in the visible region of the spectrum is also presented. The dependences of the absorptive index of glasses in both visible and in IR regions are shown, as is the reflection spectra in the IR.

  8. Optical properties of lead borate glasses containing Dy{sup 3+} ions

    Energy Technology Data Exchange (ETDEWEB)

    Pisarska, Joanna [Department of Materials Science, Silesian University of Technology, Krasinskiego 8, 40-019 Katowice (Poland)], E-mail: Joanna.Pisarska@polsl.pl

    2009-07-15

    Optical properties of lead borate glasses containing Dy{sup 3+} ions were examined using absorption and luminescence measurements and theoretical calculations based on the Judd-Ofelt framework and the Inokuti-Hirayama model. The luminescence spectra show two characteristic bands at 480 and 573 nm, which are due to {sup 4}F{sub 9/2}-{sup 6}H{sub 15/2} (blue) and {sup 4}F{sub 9/2}-{sup 6}H{sub 13/2} (yellow) transitions of trivalent Dy{sup 3+} ions. The yellow/blue luminescence and its decay were analyzed as a function of activator concentration.

  9. The new silver borate Ag{sub 3}B{sub 5}O{sub 9}

    Energy Technology Data Exchange (ETDEWEB)

    Sohr, Gerhard; Falkowski, Viktoria; Huppertz, Hubert, E-mail: hubert.huppertz@uibk.ac.at

    2015-05-15

    Single crystals of Ag{sub 3}B{sub 5}O{sub 9} were obtained via high-pressure synthesis at 3 GPa and 600 °C, using a Walker-type multianvil high-pressure device. Ag{sub 3}B{sub 5}O{sub 9} crystalizes with a=674.7(2), b=943.5(2), c=1103.5(2) pm, V=0.7025(2) nm{sup 3}, and Z=4 in the noncentrosymmetric space group P2{sub 1}2{sub 1}2{sub 1} (no. 19). The orthorhombic structure was refined from 3740 independent reflections with R1=0.0496 and wR2=0.587 (all data). It is built up from infinite corner-sharing chains of BO{sub 4} tetrahedra along the a axis, which are interconnected by BO{sub 3} groups to form a network. In the structure, three crystallographically independent sites are occupied with Ag{sup +} cations exhibiting argentophillic interactions. The synthetic conditions as well as the results of the single crystal structure analysis are presented. - Graphical abstract: Noncentrosymmetric silver borate: During investigations in the system Ag–B–O, a new noncentrosymmetric silver borate Ag{sub 3}B{sub 5}O{sub 9} was discovered. The new structure type is built up from corner-sharing BO{sub 3} and BO{sub 4} groups, forming a network. Argentophillic interactions are clearly indicated by the Ag{sup +}⋯Ag{sup +} distances present in the structure. - Highlights: • A noncentrosymmetric borate Ag{sub 3}B{sub 5}O{sub 9} is accessible via high-pressure synthesis. • Ag{sub 3}B{sub 5}O{sub 9} is the second high-pressure silver borate. • Ag{sup +}⋯Ag{sup +} distances in Ag3B5O9 clearly indicate the presence of argentophillic interactions.

  10. SYNTHESIS, STRUCTURE AND SPECTRAL PROPERTIES OF POTASSIUMALUMINA- BORATE GLASS WITH NANOCRYSTALS OF MANGANESE FERRITE

    Directory of Open Access Journals (Sweden)

    D. I. Sobolev

    2016-07-01

    Full Text Available Subject of Research.The paper presents research results of optical properties of potassium-alumina-borate glass, activated with ions of iron and manganese. The formation process of nanocrystals of manganese ferrite MnFe2O4 in potassium-alumina-borate glass host was studied. Magneto-optical characteristics were analyzed. Method. The studied glasses were synthesized by the method of charge melting in the crucible. Potassium-alumina-borate glass system was used (K2O-Al2O3-B2O3 proposed by S.A. Stepanov (Vavilov State Institute. Glass system was doped by 3 wt% of Fe2O3 and 2 wt% MnO by weight (composition 1 and 2 wt% Fe2O3 and 1 wt% MnO by weight (composition 2. The glass transition temperature was 430 °C. Segregating of the crystal phase of manganese ferrite MnFe2O4 occurred during heat treatment at 550 °C for 2 hours in a programmable muffle furnace. The absorption spectrum in the wavelength range 200-2000 nm was recorded with Perkin Elmer Lambda 650 and Varian Cary 500 spectrophotometers. The XRD patterns were obtained on Rigaku Ultima IV X-ray diffractometer by copper anode with a wavelength λ (Cu = 0.15418 nm. Magneto-optical Verde constant was measured by the angle of polarization plane rotation of the passing light through the sample when the sample is placed in magnetic field. Main Results. New technological modes of potassium-alumina-borate glass synthesis doped with ions of iron and manganese were developed and studied. It is established that during heat treatment nanocrystals of manganese ferrites are evolved with an average size of 18 nm. These glasses have a Verde constant equal to 0.9 arc.min/(cm·Oe. It is shown that obtained glasses possess high absorbance in ultra-violet and visible light spectrum. Practical Relevance. Proposed and analyzed nanoglass-ceramics could be accepted as a basis for creation of sensing environments for sensors current and magnetic field and for creation of optical isolators based on the Faraday effect.

  11. Using a Borated Panel to Form a Dual Neutron-Gamma Detector

    Energy Technology Data Exchange (ETDEWEB)

    Scott Wilde; Raymond Keegan

    2008-06-20

    A borated polyethylene plane placed between a neutron source and a gamma spectrometer is used to form a dual neutron-gamma detection system. The polyethylene thermalizes the source neutrons so that they are captured by {sup 10}B to produce a flux of 478 keV gamma-rays that radiate from the plane. This results in a buildup of count rate in the detector over that from a disk of the same diameter as the detector crystal (same thickness as the panel). Radiation portal systems are a potential application of this technique.

  12. Energy response of graphite-mixed magnesium borate TLDs to low energy x-rays

    DEFF Research Database (Denmark)

    Pelliccioni, M.; Prokic, M.; Esposito, A.

    1991-01-01

    of the energy response to very low energy x-rays are presented and evidence of agreement between experimental and calculated conversion coefficient H'(0.07, alpha = 0-degrees)/Ka is also shown. A monochromatized x-ray beam from a synchrotron radiation source in the energy range from 3 to 12 keV has been......Graphite-mixed sintered magnesium borate TL dosemeters are attractive for beta/gamma dosimetry because they combine a low energy dependence to beta-rays with near tissue or air equivalence to photon irradiations and a high sensitivity. In this paper results from the experimental measurements...

  13. Three-wave mixing mediated femtosecond pulse compression in β-barium borate.

    Science.gov (United States)

    Grün, A; Austin, Dane R; Cousin, Seth L; Biegert, J

    2015-10-15

    Nonlinear pulse compression mediated by three-wave mixing is demonstrated for ultrashort Ti:sapphire pulses in a type II phase-matched β-barium borate (BBO) crystal using noncollinear geometry. 170 μJ pulses at 800 nm with a pulse duration of 74 fs are compressed at their sum frequency to 32 fs with 55 μJ of pulse energy. Experiments and computer simulations demonstrate the potential of sum-frequency pulse compression to match the group velocities of the interacting waves to crystals that were initially not considered in the context of nonlinear pulse compression.

  14. Electrochemical characterization of electrolytes for lithium-ion batteries based on lithium difluoromono(oxalato)borate

    Energy Technology Data Exchange (ETDEWEB)

    Zugmann, Sandra; Moosbauer, Dominik; Amereller, Marius; Schreiner, Christian; Wudy, Franz; Gores, Heiner Jakob [Workgroup ' ' Electrochemistry and Electrolytes' ' , Institute of Physical and Theoretical Chemistry, University of Regensburg, Universtaetsstr. 31, D-93040 Regensburg, Bavaria (Germany); Schmitz, Rene; Schmitz, Raphael; Isken, Philipp; Dippel, Christian; Mueller, Romek; Kunze, Miriam; Lex-Balducci, Alexandra; Winter, Martin [Institute of Physical Chemistry, Westfaelische Wilhelms-University Muenster, Corrensstrasse 28/30, 48149 Muenster (Germany)

    2011-02-01

    The salt lithium difluoromono(oxalato)borate (LiDFOB) showed some promising results for lithium-ion-cells. It was synthesized via a new synthetic route that avoids chloride impurities. Here we report the properties of its solutions solvent blend ethylene carbonate/diethyl carbonate (3:7, mass ratio), including its conductivity, cationic transference number, hydrolysis, Al-current collector corrosion-protection ability and its cycling performance with some electrode materials. Some Al-corrosion studies were also performed with the help of our recently developed computer controlled impedance scanning electrochemical quartz crystal microbalance (EQCM) that proofed to be a useful tool for battery material investigations. (author)

  15. Optical spectroscopy of low-dimensional rare-earth iron borates

    Science.gov (United States)

    Popova, M. N.

    2009-04-01

    The family of RFe 3(BO 3) 4 borates (R=Pr, Nd, Eu-Er, Y) was studied by high-resolution optical absorption and Raman spectroscopies. Structural and magnetic phase transitions were detected and the types of magnetic structure were determined. Energy of crystal-field (CF) levels and exchange splitting of the ground state of the R 3+ ion were obtained from the analysis of optical spectra. CF calculations were carried out. Effective magnetic field at the R 3+ site was found, using the calculated value of the magnetic g-factor. Some peculiarities of modeling the paramagnetic susceptibility of NdFe 3(BO 3) 4 are discussed.

  16. Experience with certifying borated stainless steel as a shipping cask basket material

    Energy Technology Data Exchange (ETDEWEB)

    Abbott, D.G. (EG and G Idaho, Inc., Idaho Falls, ID (USA)); Nickell, R.E. (Applied Science and Technology, Inc., Poway, CA (USA))

    1990-01-01

    The original cask designs for a cask demonstration project featured fuel baskets constructed of borated stainless steel (bss) as a structural material. The project is intended to demonstrate casks that can be used for both shipping and storing spent nuclear fuel assemblies. The baskets were intended to maintain the fuel assemblies in a subcritical array for both normal and accident conditions. The Nuclear Regulatory Commission, however, judged bss to be unacceptable as a structural material. The cask designs were subsequently modified. The knowledge gained during this cask demonstration project may be applicable to development of bss as a basket material in future cask design. 6 refs., 2 figs., 2 tabs.

  17. Experience with certifying borated stainless steel as a shipping cask basket material

    Energy Technology Data Exchange (ETDEWEB)

    Abbott, D.G. [Idaho National Engineering Lab., Idaho Falls, ID (United States); Nickell, R.E. [Applied Science and Technology, Poway, CA (United States)

    1990-10-01

    This paper discusses the original cask designs for a cask demonstration project that has featured fuel baskets constructed of borated stainless steel (bss) as a structural material. The project is intended to demonstrate casks that can be used for both shipping and storing spent nuclear fuel assemblies. The baskets were intended to maintain the fuel assemblies in a subcritical array for both normal and accident conditions. The Nuclear Regulatory Commission, judged bss to be unacceptable as a structural material. The cask designs were subsequently modified. The knowledge gained during this cask demonstration project may be applicable to development of bss as a basket material in future cask design.

  18. Carbon sequestration via wood burial.

    Science.gov (United States)

    Zeng, Ning

    2008-01-03

    To mitigate global climate change, a portfolio of strategies will be needed to keep the atmospheric CO2 concentration below a dangerous level. Here a carbon sequestration strategy is proposed in which certain dead or live trees are harvested via collection or selective cutting, then buried in trenches or stowed away in above-ground shelters. The largely anaerobic condition under a sufficiently thick layer of soil will prevent the decomposition of the buried wood. Because a large flux of CO2 is constantly being assimilated into the world's forests via photosynthesis, cutting off its return pathway to the atmosphere forms an effective carbon sink.It is estimated that a sustainable long-term carbon sequestration potential for wood burial is 10 +/- 5 GtC y-1, and currently about 65 GtC is on the world's forest floors in the form of coarse woody debris suitable for burial. The potential is largest in tropical forests (4.2 GtC y-1), followed by temperate (3.7 GtC y-1) and boreal forests (2.1 GtC y-1). Burying wood has other benefits including minimizing CO2 source from deforestation, extending the lifetime of reforestation carbon sink, and reducing fire danger. There are possible environmental impacts such as nutrient lock-up which nevertheless appears manageable, but other concerns and factors will likely set a limit so that only part of the full potential can be realized.Based on data from North American logging industry, the cost for wood burial is estimated to be $14/tCO2($50/tC), lower than the typical cost for power plant CO2 capture with geological storage. The cost for carbon sequestration with wood burial is low because CO2 is removed from the atmosphere by the natural process of photosynthesis at little cost. The technique is low tech, distributed, easy to monitor, safe, and reversible, thus an attractive option for large-scale implementation in a world-wide carbon market.

  19. EVOLUTION OF LIGHTWEIGHT WOOD COMPOSITES

    Directory of Open Access Journals (Sweden)

    Marius C. BARBU

    2016-01-01

    Full Text Available Lightweight boards and beams in the wood-based construction and furniture industry are not a new topic. The density reduction of panels using sandwich structure with light cores was confirmed by users like doors or mobile homes more than three decades ago. Today many ways to attain a lighter wooden structure are on offer, partially in industrial application. The first one is the use of light-weight wood species like balsa, lime, pine from southern hemisphere plantations etc. limited by the availability, strength properties, gluability and so on. A second one is the sandwich structure made from hard faces like thick veneer, thin plywood, particleboard or high density thin fiberboard and cores made from honeycomb paper, very light wood species or foams like the polystyrene one. A third way to produce a light structure is to reduce the core drastically, using predesigned skeletons with special shapes and connections to the faces. The engines for these developments are on the one hand the fast growing market of knockdown furniture and on the other hand the increasing costs for energy and raw materials. Additional factors that make weight saving a primary economical objective for most producers are transportation costs, easier handling and higher acceptance among the end users. Moreover, customers demand more for ergonomical solutions regarding packaging. Many patents were generated by researchers and developers for new one-stage production processes for sandwich panels with wood- and impregnated paper-based facings made from veneers, particles or fibres and a core consisting of expandable foams, particles or embedded hard skeletons. These ideas or prototypes could be integrated in existing continuous pressing lines for wood based panels keeping some of the advantages of the continuous production technique in matters of efficiency. Some of the challenges of the light weight wooden structure are the connection in half or final parts, resistance to

  20. Carbon sequestration via wood burial

    Directory of Open Access Journals (Sweden)

    Zeng Ning

    2008-01-01

    Full Text Available Abstract To mitigate global climate change, a portfolio of strategies will be needed to keep the atmospheric CO2 concentration below a dangerous level. Here a carbon sequestration strategy is proposed in which certain dead or live trees are harvested via collection or selective cutting, then buried in trenches or stowed away in above-ground shelters. The largely anaerobic condition under a sufficiently thick layer of soil will prevent the decomposition of the buried wood. Because a large flux of CO2 is constantly being assimilated into the world's forests via photosynthesis, cutting off its return pathway to the atmosphere forms an effective carbon sink. It is estimated that a sustainable long-term carbon sequestration potential for wood burial is 10 ± 5 GtC y-1, and currently about 65 GtC is on the world's forest floors in the form of coarse woody debris suitable for burial. The potential is largest in tropical forests (4.2 GtC y-1, followed by temperate (3.7 GtC y-1 and boreal forests (2.1 GtC y-1. Burying wood has other benefits including minimizing CO2 source from deforestation, extending the lifetime of reforestation carbon sink, and reducing fire danger. There are possible environmental impacts such as nutrient lock-up which nevertheless appears manageable, but other concerns and factors will likely set a limit so that only part of the full potential can be realized. Based on data from North American logging industry, the cost for wood burial is estimated to be $14/tCO2($50/tC, lower than the typical cost for power plant CO2 capture with geological storage. The cost for carbon sequestration with wood burial is low because CO2 is removed from the atmosphere by the natural process of photosynthesis at little cost. The technique is low tech, distributed, easy to monitor, safe, and reversible, thus an attractive option for large-scale implementation in a world-wide carbon market.

  1. Use of nanofillers in wood coatings

    DEFF Research Database (Denmark)

    Nikolic, Miroslav; Lawther, John Mark; Sanadi, Anand Ramesh

    2015-01-01

    Wood has been used for thousands of years and remains an important material in the construction industry, most often protected with coatings. Development of nanotechnology allows further improvements or new performance properties to be achieved in wood coatings. Increased UV protection with nanom...... like a low level of loading, have already established nanoparticles in some areas of wood coatings. This article is a comprehensive scientific review of the published work in the use of nanofillers in wood coatings.......Wood has been used for thousands of years and remains an important material in the construction industry, most often protected with coatings. Development of nanotechnology allows further improvements or new performance properties to be achieved in wood coatings. Increased UV protection...

  2. Cold-atmospheric pressure plasma polymerization of acetylene on wood flour for improved wood plastics composites

    Science.gov (United States)

    Lekobou, William; Pedrow, Patrick; Englund, Karl; Laborie, Marie-Pierre

    2009-10-01

    Plastic composites have become a large class of construction material for exterior applications. One of the main disadvantages of wood plastic composites resides in the weak adhesion between the polar and hydrophilic surface of wood and the non-polar and hydrophobic polyolefin matrix, hindering the dispersion of the flour in the polymer matrix. To improve interfacial compatibility wood flour can be pretreated with environmentally friendly methods such as cold-atmospheric pressure plasma. The objective of this work is therefore to evaluate the potential of plasma polymerization of acetylene on wood flour to improve the compatibility with polyolefins. This presentation will describe the reactor design used to modify wood flour using acetylene plasma polymerization. The optimum conditions for plasma polymerization on wood particles will also be presented. Finally preliminary results on the wood flour surface properties and use in wood plastic composites will be discussed.

  3. Three Perspectives on the Bretton Woods System

    OpenAIRE

    Eichengreen, Barry

    1992-01-01

    The twenty years that have passed since the collapse of the Bretton Woods System provide sufficient distance to safely assess the operation of the post-World War II international monetary system. This paper considers the history and historiography of Bretton Woods from three perspectives. First, I ask how the questions posed today about the operation of Bretton Woods differ from those asked twenty years ago. Second, I explore how today's answers to familiar questions differ from the answers o...

  4. Physicochemical patterns of ozone absorption by wood

    Science.gov (United States)

    Mamleeva, N. A.; Lunin, V. V.

    2016-11-01

    Results from studying aspen and pine wood ozonation are presented. The effect the concentration of ozone, the reagent residence time, and the content of water in a sample of wood has on ozone consumption rate and ozone demand are analyzed. The residence time is shown to determine the degree of ozone conversion degree and the depth of substrate destruction. The main patterns of ozone absorption by wood with different moisture content are found. Ways of optimizing the ozonation of plant biomass are outlined.

  5. Laboratory investigations of moisture conditions in wood frame walls with wood fiber insulation

    OpenAIRE

    Geving, Stig; Lunde, Erik; Holme, Jonas

    2015-01-01

    The purpose of this study was to investigate the moisture conditions in wood frame walls with wood fiber thermal insulation in a Nordic climate. Laboratory measurements were conducted on 15 different wall configurations. The test results showed that the wall configurations with wood fiber insulation performed rather similar as those with mineral wool, in regard to measured relative humidity at the external side of the insulation layer. The laboratory tests showed that wood fiber insu...

  6. European wood-pastures in transition

    DEFF Research Database (Denmark)

    Wood-pastures are important elements of European cultural identity and have an exceptional ecological value, yet they are in decline all over Europe. The structure of wood-pastures is strongly influenced by grazing and multiple other land uses and by local and regional environmental conditions....... European Wood-Pastures in Transition examines the diverse expressions of wood-pastures across Europe. It provides a new perspective, using a social-ecological framework to explore social and ecological values, governing institutions, threats and conservation approaches. It explores the major drivers...

  7. Wood quality changes caused by mineral fertilization

    OpenAIRE

    Carlos Roberto Sette Jr; José Carlos de Deus Jr; Mario Tomazello Filho; Franciane Andrade de Pádua; Francine Neves Calil; Jean Paul Laclau

    2014-01-01

    The diverse and important use of wood from fast growth eucalyptus plantations requires the analysis of the effect of mineral fertilizers on wood quality. The objective of this study was to evaluate the anatomical characteristics and wood density from Eucalyptus grandis trees (3 m x 2 m spacing) fertilized with potassium and sodium (at planting, 6 th and 12th month). Fifteen (15) 6 years old eucalyptus trees were selected (5 trees/treatment), cut and wood samples at DBH (1,3 m) were taken for ...

  8. Wood energy 2000; Bois energie 2000

    Energy Technology Data Exchange (ETDEWEB)

    Druette, L. [Centre Scientifique et Technique du Batiment, (CSTB), 44 - Nantes (France); Lacome, T. [AFNOR, 75 - Paris (France); Roy, C. [Agence de l' Environnement et de la Maitrise de l' Energie, ADEME, 75 - Paris (France)] [and others

    2000-07-01

    The deregulation of the Electric Market and the opening of the Green Certificate exchange market force the set up of renewable energies. The wood, which is for most of european countries an important part of renewable fuel, should see the increase of its utilization. This conference on the wood energy deals the main aspects of this energy development. The papers present the wood burning furnaces technology assessment, the wood fuel market and the standardization of the appliances in this domain. Some papers also include the consequences of the big storms of december 1999. (A.L.B.)

  9. Inorganic pigments doped with tris(pyrazol-1-yl)borate lanthanide complexes: A photoluminescence study

    Energy Technology Data Exchange (ETDEWEB)

    Gheno, Giulia, E-mail: giulia.gheno@unive.it [Dipartimento di Scienze Molecolari e Nanosistemi, Università Ca’ Foscari di Venezia, Dorsoduro 2137, 30123 Venezia (Italy); Bortoluzzi, Marco; Ganzerla, Renzo [Dipartimento di Scienze Molecolari e Nanosistemi, Università Ca’ Foscari di Venezia, Dorsoduro 2137, 30123 Venezia (Italy); Enrichi, Francesco [CIVEN, Coordinamento Interuniversitario Veneto per le Nanotecnologie, Via delle Industrie 5, 30175 Marghera, Venezia (Italy)

    2014-01-15

    The inorganic pigments malachite, Egyptian blue, Ercolano blue and chrome yellow have been doped with the neutral homoleptic Ln(III) complex Ln(Tp){sub 3} (Ln=Eu, Tb; Tp=hydrotris(pyrazol-1-yl)borate) in the presence of arabic gum or acrylic emulsion as binders, in order to obtain photoluminescent materials of interest for cultural heritage restoration. The doped pigments have shown emissions associated to f–f transitions in the visible range upon excitation with UV light. Thermal and UV-light ageings have been carried out. In all the cases the photoluminescent behaviour is maintained, but in the cases of acrylic-based paints emission spectra and lifetimes are strongly influenced by thermal treatments. The choice of binder and pigments influences the photoluminescent behaviour of the corresponding film paints. -- Highlights: • Inorganic pigments doped with photoluminescent lanthanide complexes. • Hydrotris(pyrazol-1-yl)borate (Tp) as antenna-ligand for Eu(III) and Tb(III). • Emission associated to f–f transitions upon excitation with UV light. • Photoluminescence of paints influenced by the choice of binder and pigments. • Photoluminescence after ageing depending upon the type of binder.

  10. Ag-Pb Interaction and Enhanced Fluorescence Emission of Pb^2+ in Lead Borate Glasses

    Science.gov (United States)

    Mallur, Saisudha; Giri, Prakash; Dc, Mahendra; Babu, P. K.

    2012-06-01

    We carried out Pb^2+ fluorescence measurements in lead borate glasses and studied the effect of adding Ag into the base glass. Lead borate glasses containing Ag (0 and 3 mol%) were prepared by the usual melt quench method. The prepared glasses were then annealed near the glass transition temperature (400 ^oC) at 5, 10, 20 and 30h. Fluorescence spectra of all these samples were obtained using different excitation wavelengths. In general, Pb^2+ monomers are expected to have emission at wavelength less than 400nm. However, no emission in this region was observed due to the base glass absorption. The emission observed at 450nm is attributed to ^3P1->^1S0 transition of Pb^2+ ions in dimer centers. Addition of Ag enhances the Pb^2+ luminescence intensity at 450 nm which also shows an increase with the annealing time. The possible mechanisms for the fluorescence enhancement in the present glass could be the energy transfer from isolated Ag particles and local field effects due to the difference between the dielectric functions of the glass matrix and the silver particles.

  11. Effect of copper oxide on structure and physical properties of lithium lead borate glasses

    Science.gov (United States)

    Kashif, I.; Ratep, A.

    2015-09-01

    Copper-doped Lead lithium borate glass samples with the composition of (35- x) Pb3O4- xCuO-65Li2B4O7, where x = 5, 10, 15 or 20 mol%, have been prepared by melt quenching technique. Glass-forming ability, density, electrical conductivity, magnetic susceptibility and structural properties of lead lithium borate glasses have been investigated. IR spectroscopic data show that the copper ions play the role of glass modifier. Addition of CuO influences BO3 ↔ BO4 conversion. Density is expressed in terms of the structural modifications that take place in glass matrix. The increase in Tg reflects an increase in bond strength, and samples obtain more rigid glass structure. Electrical conductivity and magnetic susceptibility χ data show a variable behavior with the increase in the copper content in two valance states Cu+ and Cu+2. In addition, optical properties depend on the change of the role of copper ions in the samples' structure. Optical energy band gap E opt and Urbach energy E tail are determined. The increase in E opt and UV cutoff with an increase in CuO content is due to the decrease in non-bridging oxygen concentration. The decrease in E tail at higher concentrations is attributed to the copper ion accumulation in the interstitial positions and to the formation of orthoborate groups. These samples are suitable for the green light longpass filters.

  12. Effect of Ag Particles on the Fluorescence Properties of Eu Ions in Lead Borate Glasses

    Science.gov (United States)

    Giri, Prakash; Dc, Mahendra; Mallur, Saisudha; Babu, P. K.

    2011-11-01

    We have investigated the effect of Ag particles on the fluorescence of trivalent Eu ions in lead borate glasses. Lead borate glasses were prepared with varying Ag content (0 to 3 mol%) and sizes of Ag particles were controlled by varying the duration of annealing near the glass transition temperature. Fluorescence spectra of all these samples were obtained at two different excitation wavelengths (395 nm and 464 nm). Glass samples with Ag particles show an increase in the intensities for the major peaks in the Eu fluorescence spectra, appearing near 589 nm and 613 nm. Detailed analysis show that the enhancement effects clearly depend on the duration of annealing and the concentration of Ag. Fluorescence intensity enhancement is readily observed at relatively shorter annealing time (5 h) for samples with higher Ag concentration whereas a much longer annealing time (25 h) is required to observe any significant enhancement in fluorescence intensity for lower concentration of Ag. For higher concentrations of Ag, a broad feature is seen around 450 nm due to the emission from Ag particles and the effect of Ag is more pronounced for the fluorescence peak at 589 nm.

  13. New High-Pressure Gallium Borate Ga2B3O7(OH) with Photocatalytic Activity.

    Science.gov (United States)

    Vitzthum, Daniela; Schauperl, Michael; Strabler, Christof M; Brüggeller, Peter; Liedl, Klaus R; Griesser, Ulrich J; Huppertz, Hubert

    2016-01-19

    The new high-pressure gallium borate Ga2B3O7(OH) was synthesized in a Walker-type multianvil apparatus under high-pressure/high-temperature conditions of 10.5 GPa and 700 °C. For the system Ga-B-O-H, it is only the second known compound next to Ga9B18O33(OH)15·H3B3O6·H3BO3. The crystal structure of Ga2B3O7(OH) was determined by single-crystal X-ray diffraction data collected at room temperature. Ga2B3O7(OH) crystallizes in the orthorhombic space group Cmce (Z = 8) with the lattice parameters a = 1050.7(2) pm, b = 743.6(2) pm, c = 1077.3(2) pm, and V = 0.8417(3) nm(3). Vibrational spectroscopic methods (Raman and IR) were performed to confirm the presence of the hydroxyl group. Furthermore, the band gap of Ga2B3O7(OH) was estimated via quantum-mechanical density functional theory calculations. These results led to the assumption that our gallium borate could be a suitable substance to split water photocatalytically, which was tested experimentally.

  14. Mixed polaronic-ionic conduction in lithium borate glasses and glass-ceramics containing copper oxide

    Science.gov (United States)

    Khalil, M. M. I.

    2007-03-01

    The effect of electric field strength on conduction in lithium borate glasses doped with CuO with different concentration was studied and the value of the jump distance of charge carrier was calculated. The conductivity measurements indicate that the conduction is due to non-adiabatic hopping of polarons and the activation energies are found to be temperature and concentration dependent. Lithium borate glasses are subjected to carefully-programmed thermal treatments which cause the nucleation and growth of crystalline phases. X-ray diffraction analysis confirmed the amorphous nature for the investigated glass sample and the formation of crystalline phase for annealed samples at 650 °C. The main separated crystalline phase is Li2B8O13. The scanning electron micrographs of some selected glasses showed a significant change in the morphology of the films investigated due to heat treatment of the glass samples. It was found that the dc-conductivity decreases with an increase of the HT temperature. The decrease of dc conductivity, with an increase of the HT temperature, can be related to the decrease in the number of free ions in the glass matrix. There is deviation from linearity at high temperature regions in the logσ-1/T plots for all investigated doped samples at a certain temperature at which the transition from polaronic to ionic conduction occurs. The hopping of small polarons is dominant at low temperatures, whereas the hopping of Li+ ions dominates at high temperatures.

  15. Mixed polaronic-ionic conduction in lithium borate glasses and glass-ceramics containing copper oxide

    Energy Technology Data Exchange (ETDEWEB)

    Khalil, M.M.I. [National Center for Radiation Research and Technology, Radiation Physics Department, Cairo (Egypt)

    2007-03-15

    The effect of electric field strength on conduction in lithium borate glasses doped with CuO with different concentration was studied and the value of the jump distance of charge carrier was calculated. The conductivity measurements indicate that the conduction is due to non-adiabatic hopping of polarons and the activation energies are found to be temperature and concentration dependent. Lithium borate glasses are subjected to carefully-programmed thermal treatments which cause the nucleation and growth of crystalline phases. X-ray diffraction analysis confirmed the amorphous nature for the investigated glass sample and the formation of crystalline phase for annealed samples at 650 C. The main separated crystalline phase is Li{sub 2}B{sub 8}O{sub 13}. The scanning electron micrographs of some selected glasses showed a significant change in the morphology of the films investigated due to heat treatment of the glass samples. It was found that the dc-conductivity decreases with an increase of the HT temperature. The decrease of dc conductivity, with an increase of the HT temperature, can be related to the decrease in the number of free ions in the glass matrix. There is deviation from linearity at high temperature regions in the log{sigma}-1/T plots for all investigated doped samples at a certain temperature at which the transition from polaronic to ionic conduction occurs. The hopping of small polarons is dominant at low temperatures, whereas the hopping of Li{sup +} ions dominates at high temperatures. (orig.)

  16. Decomposition mechanism of melamine borate in pyrolytic and thermo-oxidative conditions

    Energy Technology Data Exchange (ETDEWEB)

    Hoffendahl, Carmen; Duquesne, Sophie; Fontaine, Gaëlle; Bourbigot, Serge, E-mail: serge.bourbigot@ensc-lille.fr

    2014-08-20

    Highlights: • Decomposition of melamine borate in pyrolytic and thermo-oxidative conditions was investigated. • With increasing temperature, orthoboric acid forms boron oxide releasing water. • Melamine decomposes evolving melamine, ammonia and other fragments. • Boron oxide is transformed into boron nitride and boron nitride-oxide structures through presence of ammonia. - Abstract: Decomposition mechanism of melamine borate (MB) in pyrolytic and thermo-oxidative conditions is investigated in the condensed and gas phases using solid state NMR ({sup 13}C and {sup 11}B), X-ray photoelectron spectroscopy (XPS), pyrolysis-gas chromatography–mass spectrometry (py-GCMS) and thermogravimetric analysis coupled with a Fourier transform infrared spectrometer (TGA–FTIR). It is evidenced that orthoboric acid dehydrates to metaboric and then to boron oxide. The melamine is partially sublimated. At the same time, melamine condensates, i.e., melem and melon are formed. Melon is only formed in thermo-oxidative conditions. At higher temperature, melem and melon decompose releasing ammonia which reacts with the boron oxide to form boron nitride (BN) and BNO structures.

  17. Durability and shielding performance of borated Ceramicrete coatings in beta and gamma radiation fields

    Energy Technology Data Exchange (ETDEWEB)

    Wagh, Arun S., E-mail: asw@anl.gov [Environmental Science Division, Argonne National Laboratory, 9700 S. Cass Avenue, Argonne, IL 60439 (United States); Sayenko, S.Yu.; Dovbnya, A.N.; Shkuropatenko, V.A.; Tarasov, R.V.; Rybka, A.V.; Zakharchenko, A.A. [National Science Center, Kharkov Institute of Physics and Technology, Kharkov (Ukraine)

    2015-07-15

    Highlights: • It incorporates all suggestions by the reviewers. • Explanation to each new term is provided and suitable references are given. • Sample identities have been streamlined by revising the text and the tables. • Some figures have been redrawn. - Abstract: Ceramicrete™, a chemically bonded phosphate ceramic, was developed for nuclear waste immobilization and nuclear radiation shielding. Ceramicrete products are fabricated by an acid–base reaction between magnesium oxide and mono potassium phosphate. Fillers are used to impart desired properties to the product. Ceramicrete’s tailored compositions have resulted in several commercial structural products, including corrosion- and fire-protection coatings. Their borated version, called Borobond™, has been studied for its neutron shielding capabilities and is being used in structures built for storage of nuclear materials. This investigation assesses the durability and shielding performance of borated Ceramicrete coatings when exposed to gamma and beta radiations to predict the composition needed for optimal shielding performance in a realistic nuclear radiation field. Investigations were conducted using experimental data coupled with predictive Monte Carlo computer model. The results show that it is possible to produce products for simultaneous shielding of all three types of nuclear radiations, viz., neutrons, gamma-, and beta-rays. Additionally, because sprayable Ceramicrete coatings exhibit excellent corrosion- and fire-protection characteristics on steel, this research also establishes an opportunity to produce thick coatings to enhance the shielding performance of corrosion and fire protection coatings for use in high radiation environment in nuclear industry.

  18. In vivo and in vitro studies of borate based glass micro-fibers for dermal repairing.

    Science.gov (United States)

    Zhou, Jie; Wang, Hui; Zhao, Shichang; Zhou, Nai; Li, Le; Huang, Wenhai; Wang, Deping; Zhang, Changqing

    2016-03-01

    Full-thickness skin defects represent urgent clinical problem nowadays. Wound dressing materials are hotly needed to induce dermal reconstruction or to treat serious skin defects. In this study, the borate bioactive glass (BG) micro-fibers were fabricated and compared with the traditional material 45S5 Bioglass(®) (SiG) micro-fibers. The morphology, biodegradation and bioactivity of BG and SiG micro-fibers were investigated in vitro. The wound size reduction and angiogenic effects of BG and SiG micro-fibers were evaluated by the rat full-thickness skin defect model and Microfil technique in vivo. Results indicated that the BG micro-fibers showed thinner fiber diameter (1 μm) and better bioactivity than the SiG micro-fibers did. The ionic extracts of BG and SiG micro-fibers were not toxic to human umbilical vein endothelial cells (HUVECs). In vivo, the BG micro-fiber wound dressings obviously enhanced the formation of blood vessel, and resulted in a much faster wound size reduction than the SiG micro-fibers, or than the control groups, after 9 days application. The good skin defect reconstruction ability of BG micro-fibers contributed to the B element in the composition, which results in the better bioactivity and angiogenesis. As shown above, the novel bioactive borate glass micro-fibers are expected to provide a promising therapeutic alternative for dermal reconstruction or skin defect repair.

  19. Conversion of borate-based glass scaffold to hydroxyapatite in a dilute phosphate solution.

    Science.gov (United States)

    Liu, Xin; Pan, Haobo; Fu, Hailuo; Fu, Qiang; Rahaman, Mohamed N; Huang, Wenhai

    2010-02-01

    Porous scaffolds of a borate-based glass (composition in mol%: 6Na2O, 8K2O, 8MgO, 22CaO, 36B2O3, 18SiO2, 2P2O5), with interconnected porosity of approximately 70% and pores of size 200-500 microm, were prepared by a polymer foam replication technique. The degradation of the scaffolds and conversion to a hydroxyapatite-type material in a 0.02 M K2HPO4 solution (starting pH = 7.0) at 37 degrees C were studied by measuring the weight loss of the scaffolds, as well as the pH and the boron concentration of the solution. X-ray diffraction, scanning electronic microscopy and energy dispersive x-ray analysis showed that a hydroxyapatite-type material was formed on the glass surface within 7 days of immersion in the phosphate solution. Cellular response to the scaffolds was assessed using murine MLO-A5 cells, an osteogenic cell line. Scanning electron microscopy showed that the scaffolds supported cell attachment and proliferation during the 6 day incubation. The results indicate that this borate-based glass could provide a promising degradable scaffold material for bone tissue engineering applications.

  20. Optical and Physical Properties of Bismuth Borate Glasses Doped With Dy3+

    Directory of Open Access Journals (Sweden)

    P. Limsuwan

    2011-01-01

    Full Text Available This study reports on physical and optical properties of Dy3+ doped bismuth borate glass. The glasses containing Dy3+ in (70-xB2O3:30Bi2O3:xDy2O3 (where x = 0.0-2.5 mol% have been prepared by melt-quenching method. In order to understand the role of Dy2O3 in these glasses, the density, molar volume and optical spectra were investigated. The results show that molar volume of the glasses increase with the increasing of Dy2O3 concentration and consequently generating more non-bridging oxygen (NBOs into glass matrix. The absorption spectra of Dy3+ doped in bismuth borate glass correspond with several bands, which are assigned from the ground state, 6H15/2 to 6F3/2(761 nm, 6F5/2(806 nm, 6F7/2(907 nm, (6H7/2, 6F9/2(1099 nm, (6F11/2, 6H9/2 (1283 nm and 6H11/2(1695 nm. Moreover, the optical basicities were also theoretically determined.

  1. In situ derivatization of metals and organometallics using borate reagents in gas chromatographic speciation studies.

    Science.gov (United States)

    Zachariadis, George A

    2013-06-28

    Development of sensitive and selective analytical methods is required for trace metal and metalloids speciation analysis, including their alkyl-, phenyl- or other organometallic species. Gas chromatography is one of the most suitable techniques for effective separation of the above compounds however it requires that the analytes are volatile or semi-volatile. Today very popular derivatization methods make use of borate reagents for in situ derivatization of elements like Hg, Pb, Sn, Se, As, etc. Tetrahydroborates are suitable for hydride generation and alkylborates for alkylation of the inorganic ions of the above elements, as well as of several partially alkylated ones. This almost immediate reaction can be done in aqueous solutions and produces fully alkylated products of higher volatility suitable for separation by gas chromatography and measured by various detectors. The number of papers published in this field is constantly high, including many applications to various types of matrices, like biological, environmental, industrial, food, polymers, etc. For this reason, many articles of the last two decades are reviewed in this paper and emphasis is given to the use of borate reagents and the relative microreactions for selected elements.

  2. Effect of TeO{sub 2} on the elastic moduli of sodium borate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Saddeek, Y.B.; Abd El Latif, Lamia

    2004-05-01

    Sodium borate glass containing tellurite as Te{sub x}Na{sub 2-2x}B{sub 4-4x}O{sub 7-5x} with x=0, 0.05, 0.15, 0.25 and 0.35 have been prepared by rapid quenching. Ultrasonic velocity (both longitudinal and shear) measurements have been made using a transducer operated at the fundamental frequency of 4 MHz at room temperature. The density was measured by the conventional Archimedes method. The elastic moduli, the Debye temperature, Poisson's ratio, and the parameters derived from the Makishima-Mackenzie model and the bond compression model have been obtained as a function of TeO{sub 2} content. The monotonic decrease in the velocities and the elastic moduli, and the increase in the ring diameter and the ratio K{sub bc}/K{sub e} as a function of TeO{sub 2} modifier content reveals the loose packing structure, which is attributed to the increase in the molar volume and the reduction in the vibrations of the borate lattice. The observed results confirm that the addition of TeO{sub 2} changes the rigid character of Na{sub 2}B{sub 4}O{sub 7} to a matrix of ionic behaviour bonds (NBOs). This is due to the creation of more and more discontinuities and defects in the glasses, thus breaking down the borax structure.

  3. Luminescent borate glass for efficiency enhancement of CdTe solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Steudel, Franziska, E-mail: franziska.steudel@iwmh.fraunhofer.de [Fraunhofer Application Center for Inorganic Phosphors, Branch Lab of Fraunhofer Institute for Mechanics of Materials IWM, Lübecker Ring 2, 59494 Soest (Germany); Loos, Sebastian [Department of Electrical Engineering, South Westphalia University of Applied Sciences, Lübecker Ring 2, 59494 Soest (Germany); Ahrens, Bernd; Schweizer, Stefan [Fraunhofer Application Center for Inorganic Phosphors, Branch Lab of Fraunhofer Institute for Mechanics of Materials IWM, Lübecker Ring 2, 59494 Soest (Germany); Department of Electrical Engineering, South Westphalia University of Applied Sciences, Lübecker Ring 2, 59494 Soest (Germany)

    2015-08-15

    Rare-earth (RE) doped borate glasses are investigated for their potential as photon down-shifting cover glass for CdTe solar cells. The barium borate base glass is doped with trivalent rare-earth ions such as Sm{sup 3+}, Eu{sup 3+}, and Tb{sup 3+} showing an intense luminescence in the red (Sm{sup 3+}, Eu{sup 3+}) and green (Tb{sup 3+}) spectral range upon excitation in the ultraviolet and blue. Additionally, the glasses are double-doped with two RE ions for a broad-band absorption. The gain in short-circuit current density of CdTe solar cells with different thicknesses of the CdS buffer layer is calculated. Though the single-doped glasses already reveal a slight increase in short-circuit current density, the double-doped glasses allow for higher efficiency gains since a significant broader spectral range is covered for absorption. For a Tb{sup 3+}/Eu{sup 3+} double-doped glass with a RE doping level of 1 at% each, an efficiency increase of 1.32% can be achieved. - Highlights: • Rare-earth doped front glass for high efficiency CdTe solar cells were prepared. • Double-doping allows for higher efficiency gains than single-doping. • Efficiency enhancement of 1.32% can be achieved with Tb{sup 3+}/Eu{sup 3+} doped front glass.

  4. A new low temperature route to uranyl borates with structural variations

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Shijun [Kiel Univ. (Germany). Inst. fuer Geowissenschaften; Chinese Academy of Sciences, Guangzhou (China). Guangzhou Inst. of Geochemistry; Forschungszentrum Juelich GmbH (Germany). Inst. fuer Energie- und Klimaforschung (IEK-6); Wang, Shuao [Notre Dame Univ., IN (United States). Dept. of Civil Engineering and Geological Sciences; Notre Dame Univ., IN (United States). Dept. of Chemistry and Biochememistry; Lawrence Berkeley Lab., Berkeley, CA (United States). Actinide Chemistry Group; California Univ., Berkeley, CA (United States). Dept. of Chemistry; Polinski, Matthew J. [Notre Dame Univ., IN (United States). Dept. of Civil Engineering and Geological Sciences; Notre Dame Univ., IN (United States). Dept. of Chemistry and Biochememistry; Depmeier, Wulf [Kiel Univ. (Germany). Inst. fuer Geowissenschaften; Albrecht-Schmitt, Thomas E. [Florida State Univ., Tallahassee, FL (United States). Dept. of Chemistry and Biochemistry; Alekseev, Evgeny V. [Forschungszentrum Juelich GmbH (Germany). Inst. fuer Energie- und Klimaforschung (IEK-6); RWTH Aachen Univ. (Germany). Inst. fuer Kristallographie

    2013-10-01

    Three new uranyl borates, K(UO{sub 2})(BO{sub 3}) (1), Rb(UO{sub 2})(BO{sub 3}) (2) and Cs(UO{sub 2})(BO{sub 3}) (3) have been prepared using B{sub 2}O{sub 3} fluxes at 1000 C. 1 and 3 can also be synthesized using potassium tetraborate tetrahydrate as a molten flux at 290 C, which provides a new low temperature route to prepare actinide borates. 1 possesses an a-uranophane anion sheet topology identical to that in the previously reported compounds Li(UO{sub 2})(BO{sub 3}) and Na(UO{sub 2})(BO3). 2 and 3 display a new [UO{sub 5}]{sub 1{infinity}} anion topology with a basic building block of edge-sharing dimers comprised of (UO{sub 7}){sub 2} polyhedra. The A(UO{sub 2})(BO{sub 3}) (A = alkali metal) series shows a systematic structural evolution, which will be discussed in the main text. (orig.)

  5. Influence of the crystal structure on the stability of Ln{sup 2+} in strontium borates

    Energy Technology Data Exchange (ETDEWEB)

    Dotsenko, V.P. [Physico-Chemical Institute, Ukrainian Academy of Sciences, 86 Lustdorfskaya str., 65080 Odesa (Ukraine)], E-mail: ssclab@ukr.net; Berezovskaya, I.V.; Efryushina, N.P. [Physico-Chemical Institute, Ukrainian Academy of Sciences, 86 Lustdorfskaya str., 65080 Odesa (Ukraine); Voloshinovskii, A.S.; Stryganyuk, G.B. [Ivan Franko National University of Lviv, 8 Kyryla i Mefodiya str., 29005 Lviv (Ukraine)

    2007-04-15

    The results of luminescence measurements on Ln (Eu, Yb) doped alkaline earth (M=Ca,Sr) borates M{sub 3}(BO{sub 3}){sub 2}, MB{sub 2}O{sub 4}, M{sub 2}B{sub 5}O{sub 9}X(X=Cl,Br), MB{sub 6}O{sub 10}, MB{sub 4}O{sub 7} after high-temperature annealing in various atmospheres are reported and discussed. The stability of Ln{sup 2+}(Ln=Eu,Yb) is found to increase in the sequence Sr{sub 3}(BO{sub 3}){sub 2}borates.

  6. Effect of pH on the Electrochemical Behavior of Tantalum in Borate Buffer Solutions

    Science.gov (United States)

    Attarzadeh, F. R.; Attarzadeh, N.; Vafaeian, S.; Fattah-Alhosseini, A.

    2016-10-01

    In this research, various electrochemical methods were used to investigate the electrochemical behavior of tantalum in borate buffer solutions of various pH values, ranging from 9.0 to 6.5. Potentiodynamic polarization curves revealed that tantalum showed excellent passive behavior in borate buffer solutions. The potentiodynamic polarization and electrochemical impedance spectroscopy results showed that the passive film formed on tantalum offered its best protective behavior when the pH is 8.0, with the passivity undergoing a drastic change as the pH moved toward higher values. The semiconductive behavior of the passive films formed on tantalum was investigated by employing Mott-Schottky analysis in conjunction with a point defect model. The results indicated that the passive film exhibited n-type semiconductive behavior and that donor densities were in the range of 1.958-7.242 × 1020 cm-3. Moreover, this analysis showed that the donor density and flat band potential were quite sensitive to the pH.

  7. Durability and shielding performance of borated Ceramicrete coatings in beta and gamma radiation fields

    Science.gov (United States)

    Wagh, Arun S.; Sayenko, S. Yu.; Dovbnya, A. N.; Shkuropatenko, V. A.; Tarasov, R. V.; Rybka, A. V.; Zakharchenko, A. A.

    2015-07-01

    Ceramicrete™, a chemically bonded phosphate ceramic, was developed for nuclear waste immobilization and nuclear radiation shielding. Ceramicrete products are fabricated by an acid-base reaction between magnesium oxide and mono potassium phosphate. Fillers are used to impart desired properties to the product. Ceramicrete's tailored compositions have resulted in several commercial structural products, including corrosion- and fire-protection coatings. Their borated version, called Borobond™, has been studied for its neutron shielding capabilities and is being used in structures built for storage of nuclear materials. This investigation assesses the durability and shielding performance of borated Ceramicrete coatings when exposed to gamma and beta radiations to predict the composition needed for optimal shielding performance in a realistic nuclear radiation field. Investigations were conducted using experimental data coupled with predictive Monte Carlo computer model. The results show that it is possible to produce products for simultaneous shielding of all three types of nuclear radiations, viz., neutrons, gamma-, and beta-rays. Additionally, because sprayable Ceramicrete coatings exhibit excellent corrosion- and fire-protection characteristics on steel, this research also establishes an opportunity to produce thick coatings to enhance the shielding performance of corrosion and fire protection coatings for use in high radiation environment in nuclear industry.

  8. Zinc containing borate glasses and glass-ceramics: Search for biomedical applications

    Directory of Open Access Journals (Sweden)

    Amr M. Abdelghany

    2014-12-01

    Full Text Available Ternary soda lime borate glass and samples with ZnO replacing CaO up to 10 mol% were prepared and studied for their bone bonding ability. Fourier transform infrared (FTIR absorption spectra of the prepared glasses before and after immersion in simulated body fluid (SBF, for one or two weeks, showed the appearance of calcium phosphate (hydroxyapatite (HA which is an indication of bone bonding ability. X-ray diffraction patterns were measured for the glasses and indicated the presence of small peaks related to hydroxyapatite in the samples immersed in SBF. The glasses were heat treated with controlled two-step regime to convert them to their corresponding glass-ceramic derivatives. FTIR and X-ray diffraction measurements of the glass-ceramic samples (before and after immersion in SBF confirmed the appearance of HA which is influenced by ZnO content. The overall data are explained on the basis of current views about the corrosion behaviour of borate glasses including hydrolysis and direct dissolution mechanism.

  9. Facile synthesis of calcium borate nanoparticles and the annealing effect on their structure and size.

    Science.gov (United States)

    Erfani, Maryam; Saion, Elias; Soltani, Nayereh; Hashim, Mansor; Abdullah, Wan Saffiey B Wan; Navasery, Manizheh

    2012-11-08

    Calcium borate nanoparticles have been synthesized by a thermal treatment method via facile co-precipitation. Differences of annealing temperature and annealing time and their effects on crystal structure, particle size, size distribution and thermal stability of nanoparticles were investigated. The formation of calcium borate compound was characterized by X-ray diffraction (XRD) and Fourier Transform Infrared spectroscopy (FTIR), Transmission electron microscopy (TEM), and Thermogravimetry (TGA). The XRD patterns revealed that the co-precipitated samples annealed at 700 °C for 3 h annealing time formed an amorphous structure and the transformation into a crystalline structure only occurred after 5 h annealing time. It was found that the samples annealed at 900 °C are mostly metaborate (CaB(2)O(4)) nanoparticles and tetraborate (CaB(4)O(7)) nanoparticles only observed at 970 °C, which was confirmed by FTIR. The TEM images indicated that with increasing the annealing time and temperature, the average particle size increases. TGA analysis confirmed the thermal stability of the annealed samples at higher temperatures.

  10. Facile Synthesis of Calcium Borate Nanoparticles and the Annealing Effect on Their Structure and Size

    Directory of Open Access Journals (Sweden)

    Manizheh Navasery

    2012-11-01

    Full Text Available Calcium borate nanoparticles have been synthesized by a thermal treatment method via facile co-precipitation. Differences of annealing temperature and annealing time and their effects on crystal structure, particle size, size distribution and thermal stability of nanoparticles were investigated. The formation of calcium borate compound was characterized by X-ray diffraction (XRD and Fourier Transform Infrared spectroscopy (FTIR, Transmission electron microscopy (TEM, and Thermogravimetry (TGA. The XRD patterns revealed that the co-precipitated samples annealed at 700 °C for 3 h annealing time formed an amorphous structure and the transformation into a crystalline structure only occurred after 5 h annealing time. It was found that the samples annealed at 900 °C are mostly metaborate (CaB2O4 nanoparticles and tetraborate (CaB4O7 nanoparticles only observed at 970 °C, which was confirmed by FTIR. The TEM images indicated that with increasing the annealing time and temperature, the average particle size increases. TGA analysis confirmed the thermal stability of the annealed samples at higher temperatures.

  11. Variation in wood nutrients along a tropical soil fertility gradient.

    Science.gov (United States)

    Heineman, Katherine D; Turner, Benjamin L; Dalling, James W

    2016-07-01

    Wood contains the majority of the nutrients in tropical trees, yet controls over wood nutrient concentrations and their function are poorly understood. We measured wood nutrient concentrations in 106 tree species in 10 forest plots spanning a regional fertility gradient in Panama. For a subset of species, we quantified foliar nutrients and wood density to test whether wood nutrients scale with foliar nutrients at the species level, or wood nutrient storage increases with wood density as predicted by the wood economics spectrum. Wood nutrient concentrations varied enormously among species from fourfold in nitrogen (N) to > 30-fold in calcium (Ca), potassium (K), magnesium (Mg) and phosphorus (P). Community-weighted mean wood nutrient concentrations correlated positively with soil Ca, K, Mg and P concentrations. Wood nutrients scaled positively with leaf nutrients, supporting the hypothesis that nutrient allocation is conserved across plant organs. Wood P was most sensitive to variation in soil nutrient availability, and significant radial declines in wood P indicated that tropical trees retranslocate P as sapwood transitions to heartwood. Wood P decreased with increasing wood density, suggesting that low wood P and dense wood are traits associated with tree species persistence on low fertility soils. Substantial variation among species and communities in wood nutrient concentrations suggests that allocation of nutrients to wood, especially P, influences species distributions and nutrient dynamics in tropical forests.

  12. Nitrogen immobilization by wood-chip application: Protecting water quality in a northern hardwood forest

    Science.gov (United States)

    Homyak, P.M.; Yanai, R.D.; Burns, Douglas A.; Briggs, R.D.; Germain, R.H.

    2008-01-01

    Forest harvesting disrupts the nitrogen cycle, which may affect stream water quality by increasing nitrate concentrations, reducing pH and acid neutralizing capacity, and mobilizing aluminum and base cations. We tested the application of wood chips derived from logging slash to increase immobilization of N after harvesting, which should reduce nitrate flux to streams. In August 2004, a stand of northern hardwoods was patch-clearcut in the Catskill Mountains, NY, and four replicates of three treatments were implemented in five 0.2-ha cut patches. Wood chips were applied to the soil surface at a rate equivalent to the amount of slash smaller than eight inches in diameter (1?? treatment). A second treatment doubled that rate (2??), and a third treatment received no chips (0??). Additionally, three uncut reference plots were established in nearby forested areas. Ion exchange resin bags and soil KCl-extractions were used to monitor nitrate availability in the upper 5-10 cm of soil approximately every seven weeks, except in winter. Resin bags indicated that the wood chips retained 30% or 42% of the nitrate pulse, while for KCl extracts, the retention rate was 78% or 100% of the difference between 0?? and uncut plots. During the fall following harvest, wood-chip treated plots had resin bag soil nitrate concentrations about 25% of those in 0?? plots (p = 0.0001). In the first growing season after the cut, nitrate concentrations in wood-chip treated plots for KCl extracts were 13% of those in 0?? treatments (p = 0.03) in May and about half those in 0?? treatments (p = 0.01) in July for resin bags. During spring snowmelt, however, nitrate concentrations were high and indistinguishable among treatments, including the uncut reference plots for resin bags and below detection limit for KCl extracts. Wood chips incubated in litterbags had an initial C:N of 125:1, which then decreased to 70:1 after one year of field incubation. These changes in C:N values indicate that the wood

  13. Strength of anisotropic wood and synthetic materials. [plywood, laminated wood plastics, glass fiber reinforced plastics, polymeric film, and natural wood

    Science.gov (United States)

    Ashkenazi, Y. K.

    1981-01-01

    The possibility of using general formulas for determining the strength of different anisotropic materials is considered, and theoretical formulas are applied and confirmed by results of tests on various nonmetallic materials. Data are cited on the strength of wood, plywood, laminated wood plastics, fiber glass-reinforced plastics and directed polymer films.

  14. Social Housing: wood prefabrication techniques

    Directory of Open Access Journals (Sweden)

    Tiziana Ferrante

    2012-10-01

    Full Text Available Student housing, a particular and quite significant part of social housing, and innovation in processing and production of industrial building components made of a material (wood not adequately inquired: two fields of research that have been explored for a long time allowing here to share and compare experiences gained thus far. By a selection of samples of wooden student housing in Europe we have documented the performances of this material and we have underlined, at the same time, through what happens abroad, the need of an organic national social housing plan that can meet an unsatisfied demand and boost the construction industry during this particular stage of economic crisis.

  15. The Wood Anatomy of Rubiaceae tribes Anthospermeae and Paederieae

    NARCIS (Netherlands)

    Koek-Noorman, J.; Puff, Ch.

    1983-01-01

    Detailed wood anatomical descriptions are given for the genera Anthospermum, Nenax, Phyllis, Carpacoce, Coprosma, Neogaillonia, Crocyllis, Plocama and Spermadictyon, and miscellaneous wood anatomical data on the genera Normandia, Pomax, Opercularia, Leptodermis and Aitchisonia. The wood anatomical v

  16. 硼酸盐润滑油添加剂的研究现状和进展%Current status and progress of research on borate lubricant additives

    Institute of Scientific and Technical Information of China (English)

    王焕敏; 张治军

    2011-01-01

    综述了国内外硼酸盐润滑油添加剂的研究现状,介绍了针对其合成和作用机制研究的进展,并对其前景进行了展望.指出硼酸盐已成为近年来绿色润滑油添加剂研究领域的热点之一,有机硼酸盐润滑油添加剂克服了无机硼酸盐分散稳定性差的弱点,代表了综合性能优良的硼酸盐润滑油添加剂的发展方向.%A review is provided of the current status of research on borate lubricant additives at home and abroad. The research progress about synthesis and action mechanism of borate lubricant additives are briefed, and prospects are proposed concerning the development of borate lubricant additives in future. It is pointed out that borate has become a hot spot in the research field of green lubricant additives. Particularly, organic borates as lubricating oil additives have no shortcomings like poor dispersion stability of conventional inorganic borates, representing the development directions of novel borate lubricant additives with excellent comprehensive properties.

  17. The tribological behaviour and tribochemical study of B-N type borate esters in rapeseed oil—compound versus salt

    NARCIS (Netherlands)

    Yan, J.; Zeng, X.; Heide, van der E.; Ren, T.; Zhao, Y.D.

    2014-01-01

    Two novel borate ester additives, (2-(2-(bis(2-hydroxyethyl)amino)ethoxy)-1,3,2-dioxaborolan-4-yl)methyl oleate and a tris(2-hydroxyethyl)amine salt of (2-hydroxy-1,3,2-dioxaborolan-4-yl)methyl oleate were prepared and used as anti-wear and extreme pressure agents in rapeseed oil. The tribological p

  18. Local structure of alkalis in mixed-alkali borate glass to elucidate the origin of mixed-alkali effect

    Directory of Open Access Journals (Sweden)

    Yomei Tokuda

    2015-12-01

    Full Text Available We report the structural analysis of Na+ and Cs+ in sodium cesium borate crystals and glasses using 23Na and 133Cs magic-angle spinning nuclear magnetic resonance (MAS NMR spectroscopy. The composition dependence of NMR spectra of the borate was similar to that of the silicate: (1 the peak position of cesium borate crystals shifted to upfield for structures with larger Cs+ coordination numbers, (2 the MAS NMR spectra of xNa2O-yCs2O-3B2O3 (x = 0, 0.25, 0.5, 0.75, 1.0, x + y = 1 glass showed that the average coordination number (CN of both the alkali cations decreases with increasing Cs+/(Na+ + Cs+ ratio. However, the degree of decrement in borates is much smaller than that in silicates. We have considered that the small difference in CN is due to 4-coordinated B, because it is electrically compensated by the alkali metal ions resulting in the restriction of having various coordinations of O to alkali metal.

  19. Improved green-light-emitting pyrotechnic formulations based on tris(2,2,2-trinitroethyl)borate and boron carbide.

    Science.gov (United States)

    Klapötke, Thomas M; Krumm, Burkhard; Rusan, Magdalena; Sabatini, Jesse J

    2014-08-28

    Green-light-emitting pyrotechnic compositions based on tris(2,2,2-trinitroethyl)borate (TNEB) and boron carbide have been investigated. The best performing formulations were found to be insensitive to various ignition stimuli, and exhibited very high spectral purities and luminosities compared to previously reported green-light-emitting formulations.

  20. Breaker concentrations required to improve the permeability of proppant packs damaged by concentrated linear and borate-crosslinked fracturing fluids

    Energy Technology Data Exchange (ETDEWEB)

    Brannon, H. (BJ Services (United States)); Pulsinelli, R.J. (Dowell Schlumberger, Tulsa, OK (United States))

    1992-11-01

    This paper reports on the concentrations of an oxidative breaker required to reduce significantly the proppant-pack permeability damage caused by aqueous hydraulic fracturing fluids. Long-term, proppant-pack permeability testing was used to evaluate linear and borate-crosslinked gels. Results indicate that increasing the breaker concentration can reduce proppant-pack permeability damage very effectively.

  1. Near-Zero Thermal Expansion and High Ultraviolet Transparency in a Borate Crystal of Zn4 B6 O13.

    Science.gov (United States)

    Jiang, Xingxing; Molokeev, Maxim S; Gong, Pifu; Yang, Yi; Wang, Wei; Wang, Shuaihua; Wu, Shaofan; Wang, Yingxia; Huang, Rongjin; Li, Laifeng; Wu, Yicheng; Xing, Xianran; Lin, Zheshuai

    2016-09-01

    Intrinsic isotropic near-zero thermal expansion is discovered in borate crystal Zn4 B6 O13 with high transparency in the ultraviolet region. First-principles calculations demonstrate that the very low thermal expansion originates mainly from the invariability of the solid [B24 O48 ] truncated octahedra that are fixed by the [Zn4 O13 ] clusters in the ZBO structure.

  2. Effect of borates on thermal degradation and flame retardancy of epoxy resins using polyhedral oligomeric silsesquioxane as a curing agent

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Hongyu [State Key Laboratory of Fire Science, University of Science and Technology of China, 96 Jinzhai Road, Hefei, Anhui 230026 (China); Department of Building and Construction, City University of Hong Kong and USTC-CityU Joint Advanced Research Centre, Suzhou (China); Suzhou Key Laboratory of Urban Public Safety, Suzhou Institute of University of Science and Technology of China, Suzhou (China); Wang, Xin; Yu, Bin; Song, Lei [State Key Laboratory of Fire Science, University of Science and Technology of China, 96 Jinzhai Road, Hefei, Anhui 230026 (China); Hu, Yuan, E-mail: yuanhu@ustc.edu.cn [State Key Laboratory of Fire Science, University of Science and Technology of China, 96 Jinzhai Road, Hefei, Anhui 230026 (China); Suzhou Key Laboratory of Urban Public Safety, Suzhou Institute of University of Science and Technology of China, Suzhou (China); Yuen, Richard K.K. [Department of Building and Construction, City University of Hong Kong and USTC-CityU Joint Advanced Research Centre, Suzhou (China)

    2012-05-10

    Highlights: Black-Right-Pointing-Pointer Flame retarded epoxy resins with borates were prepared using POSS as a curing agent. Black-Right-Pointing-Pointer Borates and POSS exhibited a synergistic effect on flame retardancy of epoxy resins. Black-Right-Pointing-Pointer Incorporation of borates and POSS significantly reduced the heat release rate. - Abstract: A series of flame-retardant epoxy resins containing boron and silicon were obtained through a crosslinking reaction, using tris (2-hydroxypropyl) borate (THPB) together with octaaminophenyl POSS (OapPOSS) as the curing agents. The limiting oxygen index (LOI) reached 30.5% when the contents of boron and silicon in the cured system were 1.5% and 0.5%, respectively, indicating that THPB and OapPOSS exhibited good flame retardant effect on epoxy resins (EP). Microscale combustion calorimetry (MCC) results indicated that the peak heat release rate (PHRR) and total heat release (THR) of the cured systems were reduced by 69% and 46%, respectively, compared to those of pure EP. Moreover, the thermal degradation process and flame retardant mechanism of the composites were investigated by TGA, real time FTIR and TG-FTIR. The chemical components of the char residues were explored by XPS.

  3. Microwave Irradiation Treatment of Wood Flour and Its Application in PVC-Wood Flour Composites

    Institute of Scientific and Technical Information of China (English)

    HU Shengfei; CHEN Wen; LIU Weihua; LI Huaxing

    2007-01-01

    The technique of microwave irradiation induced free radical bulk- polyaddition reactions in porous wood flour was used to modify wood flour. The behaviors of the modified wood flour under microwave irradiation, such as thermal stability and moisture sorption properties, were studied. A kind of semiinterpenetrating polymer network wood four (Semi-IPN-WF) can be formed through polymerization of MMA in the porous wood flour by microwave irradiation, and the thermal decomposition temperature of the semi-IPN-WF is considerably increased. PVC/Semi-IPN-WF composites were prepared by melt mixing in double rolls,which exhibit improved rheological properties, lower water sorption properties and outstanding mechanical performances.

  4. Effect of Wood Fillers on the Viscoelastic and Thermophysical Properties of HDPE-Wood Composite

    Directory of Open Access Journals (Sweden)

    M. Tazi

    2016-01-01

    Full Text Available Wood polymer composites (WPC have well proven their applicability in several fields of the plasturgy sector, due to their aesthetics and low maintenance costs. However, for plasturgy applications, the characterization of viscoelastic behavior and thermomechanical and thermophysical properties of WPC with the temperature and wood filler contents is essential. Therefore, the processability of polymer composites made up with different percentage of wood particles needs a better understanding of materials behaviors in accordance with temperature and wood particles contents. To this end, a numerical analysis of the viscoelastic, mechanical, and thermophysical properties of composite composed of high density polyethylene (HDPE reinforced with soft wood particles is evaluated.

  5. Institutionalization of a Retention Model

    Science.gov (United States)

    Davis, E. J.; Campbell, A.

    2006-05-01

    Bowie State University and NASA Goddard Space Flight Center have, for the past 10 years, worked diligently together to enhance the science, mathematics, engineering and technology (SMET) domain. Efforts made, because of a Model Institutions for Excellence (MIE) Award, have changed the landscape of the SMET domain by increasing the retention and graduation rates, the number of students entering graduate and professional schools, and the number of students entering SMET related careers for minorities and women. Several initiatives a Scholarship Program, PRISEM Tutoring Center, Safety-net Program, Research emphasis, Focused Mentoring, a Summer Academy for accepted incoming students, a Bridge Program for students needing assistance being admitted to the University, the RISE Program and the Bowie State Satellite Operations and Control Center (BSOCC) provide the nurturing, mentoring, and opportunities for our students. As a result of efforts made, the retention rate has increase to approximately 80%, the graduation rate has increased 40%, and 85% of the SMET students are now interested or entering graduate and professional schools. Successes that have been documented by various assessment activities have led to the institutionalization of the Retention Model of the MIE Initiative. It is anticipated that University-wide application of the retention model will prove the incentives necessary to obtain similar results as the MIE Initiative.

  6. Lake retention of manufactured nanoparticles

    NARCIS (Netherlands)

    Koelmans, A.A.; Quik, J.T.K.; Velzeboer, I.

    2015-01-01

    For twenty-five world lakes and three engineered nanoparticles (ENP), lake retention was calculated using a uniformly mixed lake mass balance model. This follows similar approaches traditionally used in water quality management. Lakes were selected such that lake residence times, depths and areal hy

  7. Strategies for improving employee retention.

    Science.gov (United States)

    Verlander, Edward G; Evans, Martin R

    2007-03-28

    This article proposes a solution to the perennial problem of talent retention in the clinical laboratory. It includes the presentation of 12 strategies that may be used to significantly improve institutional identity formation and establishment of the psychological contract that employees form with laboratory management. Identity formation and psychological contracting are deemed as essential in helping reduce employee turnover and increase retention. The 12 conversational strategies may be used as a set of best practices for all employees, but most importantly for new employees, and should be implemented at the critical moment when employees first join the laboratory. This time is referred to as "retention on-boarding"--the period of induction and laboratory orientation. Retention on-boarding involves a dialogue between employees and management that is focused on the psychological, practical, cultural, and political dimensions of the laboratory. It is placed in the context of the modern clinical laboratory, which is faced with employing and managing Generation X knowledge workers. Specific topics and broad content areas of those conversations are outlined.

  8. Maslow's Hierarchy and Student Retention.

    Science.gov (United States)

    Brookman, David M.

    1989-01-01

    Abraham Maslow's hierarchy of needs offers perspective on student motivation and a rationale for college retention programing. Student affairs and faculty interventions addressing student safety needs and engaging students' sense of purpose reinforce persistence. A mentor program is a possible cooperative effort between student personnel and…

  9. DEVELOPING A NO-VOC WOOD TOPCOAT

    Science.gov (United States)

    The paper reports an evaluation of a new low-VOC (volatile organic compound) wood coating technology, its performance characteristics, and its application and emissions testing. The low-VOC wood coating selected for the project was a two-component, water-based epoxy coating. Poly...

  10. COMPOSITES FROM RECYCLED WOOD AND PLASTICS

    Science.gov (United States)

    The ultimate goal of this research was to develop technology to convert recycled wood fiber and plastics into durable products that are recyclable and otherwise environmentally friendly. Two processing technologies were used to prepare wood-plastic composites: air-laying and melt...

  11. Evaluation of Paulownia elongata wood polyethylene composites

    Science.gov (United States)

    Paulownia wood flour (PWF), a byproduct of milling lumber, was employed as a bio-filler and blended with high density polyethylene (HDPE) via extrusion. Paulownia wood (PW) shavings were milled through a 1-mm screen then separated via shaking into various particle fractions using sieves (#30 - < #2...

  12. Analysis of acetylated wood by electron microscopy

    NARCIS (Netherlands)

    Sander, C.; Beckers, E.P.J.; Militz, H.; Veenendaal, van W.

    2003-01-01

    The properties of acetylated solid wood were investigated earlier, in particular the anti-shrink efficiency and the resistance against decay. This study focuses on the possible changes and damage to the wood structure due to an acetylation process leading to weight per cent gains of up to 20%. Elect

  13. Least cost supply strategies for wood chips

    DEFF Research Database (Denmark)

    Möller, Bernd

    The abstract presents a study based on a geographical information system, which produce  cost-supply curves by location for forest woods chips in Denmark.......The abstract presents a study based on a geographical information system, which produce  cost-supply curves by location for forest woods chips in Denmark....

  14. Wood anatomy of the Neotropical Melastomataceae

    NARCIS (Netherlands)

    Welle, ter Ben J.H.; Koek-Noorman, Jifke

    1981-01-01

    The wood anatomy of 47 genera of the neotropical Melastomataceae is described in detail. The wood anatomy of the neotropical part of this pantropical family supports the subdivision into two groups: the subfamily Memecyloideae (the genus Mouriri) and the subfamily Melastomatoideae (all other genera)

  15. Wood and leaf anatomy of Opiliaceae

    NARCIS (Netherlands)

    Koek-Noorman, J.; Rijckevorsel, v. P.

    1983-01-01

    The wood and leaf anatomy of representatives of the 9 genera of the Opiliaceae are described in detail. It is possible to separate the genera on the base of both wood- and leaf anatomical characters. Herein the presence of cystoliths of varying shape and size is important. Some comments on the taxon

  16. Systematic wood anatomy of the Rosaceae

    NARCIS (Netherlands)

    Zhang, Shu-Yin

    1992-01-01

    The wood anatomy of the Rosaceae is surveyed and analysed, based on the study of 280 species (c. 500 specimens) belonging to 62 genera from different parts of the world. Eighteen wood anatomical characters have been used for a phenetic and phylogenetic classification. In the phenetic classification,

  17. Generalized eczematous contact dermatitis from cocobolo wood.

    Science.gov (United States)

    Guanche, Anna D; Prawer, Steven

    2003-06-01

    Occupational contact with cocobolo wood (Papilionaceae, Dalbergia retusa) has been reported to rarely cause delayed hypersensitivity reactions. We report the case of a 53-year-old furniture and cabinetmaker who exhibited a generalized reaction mimicking erythroderma after exposure to sawdust from the wood. Patch testing to plants and woods standard (Chemotechnique, Dormer Laboratories, Ontario, Canada) was negative, and the specific allergen in cocobolo, obtusaquinone, was not available to us. The patient was tested instead to shavings of various woods as well as to sawdust of the suspected wood in petrolatum. He exhibited an exuberant response (+++) to both shavings and sawdust of cocobolo. After successful patch testing with shavings and sawdust in the absence of the purified chemical allergen, avoidance of the timber resulted in the resolution of his symptoms.

  18. Wood for energy production. Technology - environment - economy

    Energy Technology Data Exchange (ETDEWEB)

    Serup, H.; Falster, H.; Gamborg, C. [and others

    1999-10-01

    `Wood for Energy Production`, 2nd edition, is a readily understood guide to the application of wood in the Danish energy supply. The first edition was named `Wood Chips for Energy Production`. It describes the wood fuel from forest to consumer and provides a concise introduction to technological, environmental, and financial matters concerning heating systems for farms, institutions, district heating plants, and CHP plants. The individual sections deal with both conventional, well known technology, as well as the most recent technological advances in the field of CHP production. The purpose of this publication is to reach the largest possible audiance, and it is designed so that the layman may find its background information of special relevance. `Wood for Energy Production` is also available in German and Danish. (au)

  19. Wood Crosscutting Process Analysis for Circular Saws

    Directory of Open Access Journals (Sweden)

    Jozef Krilek

    2016-11-01

    Full Text Available This article deals with the influence of some cutting parameters (geometry of cutting edge, wood species, and circular saw type and cutting conditions on the wood crosscutting process carried out with circular saws. The establishment of torque values and feeding power for the crosswise wood cutting process has significant implications for designers of crosscutting lines. The conditions of the experiments are similar to the working conditions of real machines, and the results of individual experiments can be compared with the results obtained via similar experimental workstations. Knowledge of the wood crosscutting process, as well as the choice of suitable cutting conditions and tools could decrease wood production costs and save energy. Changing circular saw type was found to have the biggest influence on cutting power of all factors tested.

  20. Dimensional stability of heat treated wood floorings

    Directory of Open Access Journals (Sweden)

    Vjekoslav Živković

    2008-07-01

    Full Text Available Heat treated wood (HTW is successfully applied for floorings due to its better moisture resistance, increased dimensional stability, and uniform colour change to darker, brownish colours. The aim of this work was to define the hygroscopic range and equilibrium moisture content at ambient conditions of heat treated wood of two wood species – ash and beech. Material was treated at two temperature levels, 190 and 210 °C, and the properties were compared with native wood. The reduction in dimensional changes is expressed by volumetric shrinking and Anti Shrink Efficiency (ASE. Additionally, parquet elements were made out of such HTW, oil-impregnated and waxed, and subsequently tested for water vapour and liquid water permeability. Shrinking gradients of HTW were not reduced in comparison with native beech wood, but the absolute reduction in water uptake resulted in cca 50 % lower EMC values and up to cca 60 % improved ASE values. Surface treatment further improved the hygroscopic properties of HTW.

  1. Wood Identification of 18th Century Furniture. Interpreting Wood Naming Inventoires

    Directory of Open Access Journals (Sweden)

    Rocio Astrid BERNAL

    2011-09-01

    Full Text Available The 18th century Portuguese church furniture represents an extraordinary richness recognised worldwide, which demands safeguarding and valorisation. The identification of the wood of furniture artworks is the most important component for its comprehension and preservation. In this work wood anatomical characters of an 18th century Portuguese decorative furniture set from the Colegiada de São Martinho de Cedofeita, in Porto, were analysed to identify the woods used for manufacturing and to clarify their common names. Furthermore, the objectives were to recognise some of the criteria for choice of wood as well as the source of each wood. The woods identified from 16 fragments belong to Apuleia sp., Acacia sp., Neolamarckia sp. and Castanea sativa. Apuleia sp. and Acacia sp. woods most likely arrived from Brazil, while the Neolamarckia sp. woods likely arrived from India and the C. sativa woods from Portugal. The results are in accordance with the known Portuguese colonial sea routes of the 15th -18th centuries. Interestingly the terms found in the inventories can refer to finishing methods instead to the name of the woods, as for instance “oil wood” can refer to “oiled wood” or “linseed oiled wood”. The species choice may be related to the mechanical properties of the wood as well as the original tree size. Two large planks of Acacia sp. were used for the top of the “Portuguese arcaz”, and Apuleia sp. was found on main structural elements of this set of furniture, suggesting that wood colour was also important. Woods from Neolamarckia sp. and C. sativa, were also identified, being Castanea wood present only in the most recent pieces of the furniture set.

  2. METAL CORROSION IN WATERBORNE PRESERVATIVE- TREATED WOOD

    Directory of Open Access Journals (Sweden)

    Krisdianto Sugiyanto

    2010-12-01

    Full Text Available The rigidity and firmness of wooden construction and furniture those are joined by metal screws depend on corrosion rate of these metals. This paper examines the weight-loss percentage of metal screws used in wood samples that have been treated with water-borne preser vative (i.e.3% borax boric acid and 3% diffusol CB and concurrently investigates the effect of brake fluid on preventing metal corrosion. Wood samples tested included three acacia and one eucalypts wood species which were grouped into sapwood and heartwood containing samples. Wood samples fastened with metal screws were freely suspended in glass jars that contained 25 ml of sulphuric acid (H2SO4 to keep the humidity rate above 90%. After 12 months, the metal screws lost their weight due to the corrosion brought about by the related factors either in separate individual or in combination, which comprised brake and fluid-dipping , wood species, wood portion (sapwood and heartwood, kinds of preser vatives used. Corrosion rates of metal screws fastened in eucalypts wood sample as indicated by the screw-weight loss (i.e. 5.8% was more severe than that fastened in acacia wood. Furthermore, corrosion rate of metal screws as fixed firmly in sapwood sample proceeded faster than that in heartwood. This might be caused by the higher moisture content in sapwood. On the other hand, corrosion rate of the screws as fastened in waterborne-preser vative-treated wood samples was greater than that in non-preser ved wood due to electrokinetic characteristics and ionic potential exhibited by the preser vative thereby intensif ying the screw-corrosion process. Meanwhile, less severe corrosion was obser ved and recorded on the screws pre-dipped in brake fluid compared to those on the non-dipped screws

  3. Tribological characteristics of monodispersed cerium borate nanospheres in biodegradable rapeseed oil lubricant

    Energy Technology Data Exchange (ETDEWEB)

    Boshui, Chen, E-mail: boshuichen@163.com; Kecheng, Gu; Jianhua, Fang; Jiang, Wu; Jiu, Wang; Nan, Zhang

    2015-10-30

    Graphical abstract: - Highlights: • Monodispersed stearic acid-capped cerium borate composite nanoparticles were prepared by hydrothermal method. Their morphologies, element compositions, size distributions, crystal and chemical structures, hydrophobic characteristics were also characterized. • The surface-capped cerium borate nanoparticles exhibited excellent dispersing stability in rapeseed oil. As new lubricating additives, they were also outstanding in enhancing friction-reducing and anti-wear capacities of rapeseed oil in biodegradable rapeseed oil. The results presented in this paper would be of important significance for developing green lubricants and lubricant additives. • The prominent tribological performances of SA/CeBO{sub 3} in rapeseed oil were investigated and attributed to the formation of a composite boundary lubrication film mainly composed of lubricous tribochemical species on the tribo-surfaces. - Abstract: Stearic acid-capped cerium borate composite nanoparticles, abbreviated as SA/CeBO{sub 3}, were prepared by hydrothermal method. The morphologies, element compositions, size distributions, crystal and chemical structures, hydrophobic characteristics, of SA/CeBO{sub 3} were characterized by scanning electron microscope, energy dispersive X-ray spectrometer, dynamic laser particle size analyzer, X-ray diffraction, and Fourier transform infrared spectrometer, respectively. The friction and wear performances of SA/CeBO{sub 3} as a lubricating additive in a rapeseed oil were evaluated on a four-ball tribo-tester. The tribochemical characteristics of the worn surfaces were investigated by X-ray photoelectron spectroscopy. The results showed that the hydrophobic SA/CeBO{sub 3} were monodispersed nanospheres with an average diameter of 8 nm, and exhibited excellent dispersing stability in rapeseed oil. Meanwhile, SA/CeBO{sub 3} nanospheres were outstanding in enhancing friction-reducing and anti-wear capacities of rapeseed oil. The prominent

  4. Study on the Retention and Distributions of the Copper-Based Preservative in Standing Tree Chinese Fir (Cunninghamia lanceolata

    Directory of Open Access Journals (Sweden)

    Youhua Fan

    2016-01-01

    Full Text Available In spite of some studies about the wood permeability and its improving measures, some progress has been made to study the diffusion and transmission of preservative solutions in standing trees. In the present study, copper- (Cu- based preservative with other reagents is injected into the standing tree Chinese fir using sap-flow method. The chemical compositions of the retreated woods are analyzed with Fourier transform infrared spectroscopy (FTIR and X-ray photoelectron spectroscopy (XPS. The samples from different height positions are analyzed with scanning electron microscope (SEM and atomic absorption spectroscopy (AAS to obtain microstructures and preservative retention, respectively. The results indicate that the preservative solutions with lower concentrations are more conducive to diffusion and transmission in the wood. Moreover, the preservative retention at different height position has a greater concentration gradient for composite preservative solutions than those of the single preservative solutions. Solidified preservative particles are observed in xylem rays with SEM. The results of the present study provide some useful information for the functional design of the target wood products.

  5. 78 FR 57927 - Credit Risk Retention

    Science.gov (United States)

    2013-09-20

    ... Part 246 24 CFR Part 267 Credit Risk Retention; Proposed Rule #0;#0;Federal Register / Vol. 78 , No... HOUSING AND URBAN DEVELOPMENT 24 CFR Part 267 RIN 2501-AD53 Credit Risk Retention AGENCY: Office of the... published in the Federal Register on April 29, 2011, and to implement the credit risk retention...

  6. Implementation of new technologies in wood industry and their effect in wood products quality

    Directory of Open Access Journals (Sweden)

    ELVA ÇAUSHI

    2014-06-01

    Full Text Available There are about 300 companies producing furniture and about 250 small and medium enterprises (SME producing sawn timber, which operate in the field of wood industry in Albania. This wood industry production is being challenged by the increasing demand in the domestic market, ranging from kitchen furniture to office and schools furniture, bedroom furniture, doors, windows, and saw timber in different dimensions. The production from the wood industry can fulfill about 80% of the domestic market demand. The remaining 20% of domestic market needs in wood furniture are afforded by import. Small entities do not make serious investment in technology. Big enterprises such as Ardeno in Tirana, Biçaku in Durres, Shaga in Tirana, Ital-wood in Elbasan, Dafinori in Shkoder, etc., have made remarkable investments in their technology. They have installed several mechanized lines of production. So, Ital-wood has invested in a mechanized saw timber production line; Bicaku in wood panels coated with PVC lines; Dafinori in a wood handrail production technologic line; Ardeno in wooden chairs production technologic lines, and Shaga in the production of furniture with particle panels. These enterprises are using modern numerical command machines, vacuum presses for gluing PVC, cutting equipment for panels with laser ray, finishing lines with electrostatic field, modern lines of pneumatic transport for wood dust etc. These investments in new technologies have increased the quantity and quality of native wood products.

  7. Lithium ion conductivity of gel polymer electrolytes containing insoluble lithium tetrakis(pentafluorobenzenethiolato) borate

    Energy Technology Data Exchange (ETDEWEB)

    Aoki, Takahiro; Ohta, Takayuki; Fujinami, Tatsuo [Department of Materials Science and Chemical Engineering, Faculty of Engineering, Shizuoka University, 3-5-1, Johoku, Hamamatsu 432-8561 (Japan)

    2006-06-01

    Lithium ion conducting gel polymer electrolytes composed of insoluble lithium tetrakis(pentafluorobenzenethiolato) borate (LiTPSB), poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) and ethylene carbonate-propylene carbonate mixed solvent (EC-PC) were prepared and their ionic conductivities and electrochemical stabilities were investigated. Ionic conductivity was largely dependent on the contents of EC-PC and LiTPSB. Gel polymer electrolyte containing optimized content of 50 (LiTPSB)-50 (PVDF-HFP/EC-PC (13:87wt.%)) exhibited ionic conductivity of 4x10{sup -4}Scm{sup -1} at 30{sup o}C, lithium ion transference number of 0.33 and anodic oxidation potential of 4.2V. (author)

  8. Lithium ion conductivity of gel polymer electrolytes containing insoluble lithium tetrakis(pentafluorobenzenethiolato) borate

    Science.gov (United States)

    Aoki, Takahiro; Ohta, Takayuki; Fujinami, Tatsuo

    Lithium ion conducting gel polymer electrolytes composed of insoluble lithium tetrakis(pentafluorobenzenethiolato) borate (LiTPSB), poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) and ethylene carbonate-propylene carbonate mixed solvent (EC-PC) were prepared and their ionic conductivities and electrochemical stabilities were investigated. Ionic conductivity was largely dependent on the contents of EC-PC and LiTPSB. Gel polymer electrolyte containing optimized content of 50 (LiTPSB)-50 (PVDF-HFP/EC-PC (13:87 wt.%)) exhibited ionic conductivity of 4 × 10 -4 S cm -1 at 30 °C, lithium ion transference number of 0.33 and anodic oxidation potential of 4.2 V.

  9. Polymer electrolytes composed of lithium tetrakis(pentafluorobenzenethiolato) borate and poly(fluoroalkylcarbon)s

    Energy Technology Data Exchange (ETDEWEB)

    Aoki, Takahiro; Konno, Akinori; Fujinami, Tatsuo [Department of Materials Science and Chemical Engineering, Faculty of Engineering, Shizuoka University, 3-5-1, Johoku, Hamamatsu 432-8561 (Japan)

    2005-08-26

    Lithium ion conducting polymer electrolytes were prepared by mixing insoluble lithium tetrakis(pentafluorobenzenethiolato) borate (LiTPSB) with poly(vinylidene fluoride) (PVDF) or poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP). Their films were prepared by hot pressing and are investigated for ionic conductivity and thermal properties. LiTPSB is insoluble in PVDF. Ionic conductivity was largely dependent on the salt content for LiTPSB-PVDF composite polymer electrolytes, and exhibited higher ionic conductivity than homogeneous LiTFSI-PVDF based polymer electrolytes. Melting point and crystallinity of PVDF were independent on LiTPSB content, resulting in no difference for melting point and crystallinity between pure PVDF and LiTPSB-PVDF. Ionic conductivity was effectively improved by incorporation of 18-crown-6 or kryptofix222 for LiTPSB-PVDF based polymer electrolytes. (author)

  10. Novel Preparation of Calcium Borate/Graphene Oxide Nanocomposites and Their Tribological Properties in Oil

    Science.gov (United States)

    Li, Wei; Cheng, Zhi-Lin; Liu, Zan

    2016-11-01

    The calcium borate/graphene oxide (CB/GO) nanocomposites have been successfully prepared by a liquid phase-based ultrasonic-assisted stripping method, which were subsequently explored as lubricant additive. The structure and morphology of the as-prepared nanocomposites were characterized by FT-IR, XRD, Raman, TEM, EDS and TGA, revealing that CB nanoparticles were uniformly loaded on GO surfaces. The nanocomposites were highly dispersed into the base oil by sand milling. The tribological properties of CB/GO nanocomposites as lubricating oil additive were investigated using a four-ball machine, and the wear scar surfaces were observed by the 3D Laser Scanning Microscope. The results indicated that CB/GO nanocomposites were of excellent antifriction, antiwear ability and load-carrying capacity.

  11. Synthesis and Crystal Structure of Borate Oxide Co3BO5

    Institute of Scientific and Technical Information of China (English)

    张浩; 程文旦; 黄子祥

    2001-01-01

    A mix-charge cation solid-state borate oxide Co3BO5 has beensynthesized and its structure has been determined by single-crystal X-ray methods. It crystallizes in the orthorhombic~space group Pbam with cell parameters a=9.2963(2), b=11.948(2), c=2.9737(6) Å, V=330.30(12)Å3, Z=4, Mr=267.60, F(000)=504, μ=14.733, Dcalcd=5.381g/cm3. The structure was determined from 853 unique reflections and refined to the final residuals R=0.0633 and wR=0.1457. It has two kinds of Co cations, Co2+ and Co3+. It is composed of highly distorted [CoO4] squares and triangular [BO3] groups that are connected to form infinite two-dimensional layers.

  12. Production and characterization of hydrophobic zinc borate by using palm oil

    Institute of Scientific and Technical Information of China (English)

    Nil Baran Acarali; Nurcan Tugrul; Emek Moroydor Derun; Sabriye Piskin

    2013-01-01

    Zinc borate (ZB) was synthesized using zinc oxide, boric acid synthesized from colemanite, and reference ZB as seed. The eff ects of reaction parameters such as reaction time, reactant ratio, and seed ratio on its yield were examined. Then, the eff ects of palm oil with solvents (isopropyl alcohol (IPA), ethanol, and methanol) added to the reaction on its hydrophobicity were explored. Reactions were carried out under determined reaction conditions with magnetically and mechanically stirred systems. The produced ZB was characterized by X-ray diff raction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), and measurements of contact angle identified hydrophobicity. The results showed that hydrophobic ZB was successfully produced under determined reaction conditions. The change of process parameters influenced its yield and the usage of palm oil provided hydrophobicity.

  13. Mechanical and thermal properties of denture PMMA reinforced with silanized aluminum borate whiskers.

    Science.gov (United States)

    Zhang, Xinjing; Zhang, Xiuyin; Zhu, Bangshang; Lin, Kaili; Chang, Jiang

    2012-01-01

    The aim of this study was to investigate the mechanical and thermal properties of denture polymethyl methacrylate (PMMA) reinforced with aluminum borate whiskers (ABWs). To improve bonding between ABWs and PMMA matrix, the surface of ABWs was modified with a silane coupling agent. Varied contents of silanized ABWs -ranging between 1 and 20 wt%- were mixed into the PMMA resin matrix to prepare ABW/PMMA composites, which were subjected to three-point bending test, Vickers hardness test, and thermal analysis. Silanized ABWs improved the flexural strength, surface hardness, and thermal stability of PMMA. Optimal amount of ABWs in the PMMA matrix was 5 wt%, which provided the ABW/PMMA with maximum reinforcement.

  14. Synthesis and characterization of holmium oxide doped cadmium lead borate glasses

    Science.gov (United States)

    Alemi, A. A.; Sedghi, H.; Mirmohseni, A. R.; Golsanamlu, V.

    Holmium doped cadmium lead borate glasses were prepared from melting in appropriate proportions of a mixture of CdO, PbO2, H3BO3 and (1-2 mol %) Ho2O3 in the temperature range of 800-850 °C. The density of glass samples was measured using Archimedes Principle. The infrared spectra of the glasses in the range of 400-4000 cm-1 showed their structure systematically. No boroxol ring formation was observed in the structure of these glasses, but the conversion of 3-fold to 4-fold coordination of boron atoms in the structure of glasses was observed. The glass transition studies were done through differential scanning calorimetry. The optical analysis is done by using the Judd-Ofelt theory.

  15. Structural and time resolved emission spectra of Er 3+: Silver lead borate glass

    Science.gov (United States)

    Coelho, João; Hungerford, Graham; Hussain, N. Sooraj

    2011-08-01

    The structural properties of Er 3+: silver lead borate glass is assessed by means of SEM, X-ray mapping, EDS and Raman analysis. In order to verify the time dependency of emission spectra, steady-state luminescence spectroscopy (SSLS) and time-resolved emission spectroscopy (TRES) studies have been performed. The stimulated emission cross-sections for the NIR emission transition 4I 13/2 → 4I 15/2 (1535 nm) at 970 nm excitation are reported. The decay times were obtained by fitting one ( τm = 0.301 ms) and two ( τm1 = 0.141 ms, τm2 = 0.368 ms) distributions for the NIR transition. Furthermore, by making use of TRES measurements the decay associated spectra were obtained allowing the time dependency for the different emission bands to be elucidated.

  16. Generation of ultraviolet radiation with wide angular tolerance in cesium lithium borate crystal

    Indian Academy of Sciences (India)

    Gopal C Bhar; Pathik Kumbhakar; Anil K Chaudhary

    2000-09-01

    Tangential phase-matching has been realised in cesium lithium borate (CLBO) crystal for the first time for the generation of fourth harmonic (266 nm) of Nd:YAG and third harmonic (226.7 nm) of a dye laser radiation by second harmonic generation and sum-frequency mixing with the angular tolerance as large as 22 mrad and 21 mrad respectively, over one of the interacting beams. An energy conversion efficiency of 15% for fourth harmonic generation is obtained with a 5.5 mm thick crystal and with the average pump powers only 170 and 70 mW. A set of Sellmeier dispersion equations for the CLBO crystal have also been formulated.

  17. Novel Preparation of Calcium Borate/Graphene Oxide Nanocomposites and Their Tribological Properties in Oil

    Science.gov (United States)

    Li, Wei; Cheng, Zhi-Lin; Liu, Zan

    2017-01-01

    The calcium borate/graphene oxide (CB/GO) nanocomposites have been successfully prepared by a liquid phase-based ultrasonic-assisted stripping method, which were subsequently explored as lubricant additive. The structure and morphology of the as-prepared nanocomposites were characterized by FT-IR, XRD, Raman, TEM, EDS and TGA, revealing that CB nanoparticles were uniformly loaded on GO surfaces. The nanocomposites were highly dispersed into the base oil by sand milling. The tribological properties of CB/GO nanocomposites as lubricating oil additive were investigated using a four-ball machine, and the wear scar surfaces were observed by the 3D Laser Scanning Microscope. The results indicated that CB/GO nanocomposites were of excellent antifriction, antiwear ability and load-carrying capacity.

  18. Long Lasting Phosphorescence in Eu2+ and Ce3+ Co-Doped Strontium Borate Glasses

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Long lasting phosphorescence (LLP) was observed in Eu2+, Ce3+ co-doped strontium borate glasses prepared under the reducing atmosphere due to the emission of both Eu2+ and Ce3+. The methods of photoluminescence, thermoluminescence and phosphorescence were used to study the samples, and possible mechanism was suggested. The co-doping of Ce3+ ions poisoned the phosphorescence emission of Eu2+ because of the competition to obtain the trapped electron. The phosphorescence of Ce3+ in the sample decays more quickly than that of Eu2+, which is suggested for the reason that the emission energy of Ce3+ is higher or the distance between Ce3+ and electron traps of the glasses is longer.

  19. Thermal properties of borate crystals for high power optical parametric chirped-pulse amplification.

    Science.gov (United States)

    Riedel, R; Rothhardt, J; Beil, K; Gronloh, B; Klenke, A; Höppner, H; Schulz, M; Teubner, U; Kränkel, C; Limpert, J; Tünnermann, A; Prandolini, M J; Tavella, F

    2014-07-28

    The potential of borate crystals, BBO, LBO and BiBO, for high average power scaling of optical parametric chirped-pulse amplifiers is investigated. Up-to-date measurements of the absorption coefficients at 515 nm and the thermal conductivities are presented. The measured absorption coefficients are a factor of 10-100 lower than reported by the literature for BBO and LBO. For BBO, a large variation of the absorption coefficients was found between crystals from different manufacturers. The linear and nonlinear absorption coefficients at 515 nm as well as thermal conductivities were determined for the first time for BiBO. Further, different crystal cooling methods are presented. In addition, the limits to power scaling of OPCPAs are discussed.

  20. Efficiency of a blast furnace slag cement for immobilizing simulated borate radioactive liquid waste.

    Science.gov (United States)

    Guerrero, A; Goñi, S

    2002-01-01

    The efficiency of a blast furnace slag cement (Spanish CEM III/B) for immobilizing simulated radioactive borate liquid waste [containing H3BO3, NaCl, Na2SO4 and Na(OH)] has been evaluated by means of a leaching attack in de-mineralized water at the temperature of 40 degrees C over 180 days. The leaching was carried out according to the ANSI/ANS-16.1-1986 test. Moreover, changes of the matrix microstructure were characterized through porosity and pore-size distribution analysis carried out by mercury intrusion porosimetry (MIP), X-ray diffraction (XRD) and thermal analysis (TG). The results were compared with those obtained from a calcium aluminate cement matrix, previously published.

  1. Dispersive waves induced by self-defocusing temporal solitons in a beta-barium-borate crystal

    DEFF Research Database (Denmark)

    Zhou, Binbin; Bache, Morten

    2015-01-01

    We experimentally observe dispersive waves in the anomalous dispersion regime of a beta-barium-borate (BBO) crystal, induced by a self-defocusing few-cycle temporal soliton. Together the soliton and dispersive waves form an energetic octave-spanning supercontinuum. The soliton was excited...... in the normal dispersion regime of BBO through a negative cascaded quadratic nonlinearity. Using pump wavelengths from 1.24 to 1.4 μm, dispersive waves are found from 1.9 to 2.2 μm, agreeing well with calculated resonant phasematching wavelengths due to degenerate four-wave mixing to the soliton. We also...... observe resonant radiation from nondegenerate four-wave mixing between the soliton and a probe wave, which was formed by leaking part of the pump spectrum into the anomalous dispersion regime. We confirm the experimental results through simulations....

  2. Growth and characterization of semiorganic nonlinear optical rubidium bis-DL-malato borate single crystals

    Energy Technology Data Exchange (ETDEWEB)

    Balasubramanian, D. [Post Graduate and Research Department of Physics, Pachaiyappa' s College, Chennai 600030 (India); Sankar, R. [Crystal Growth Centre, Anna University, Chennai 600025 (India); Shankar, V. Siva [Post Graduate and Research Department of Physics, Pachaiyappa' s College, Chennai 600030 (India); Murugakoothan, P. [Post Graduate and Research Department of Physics, Pachaiyappa' s College, Chennai 600030 (India)], E-mail: pmurugakoothan@yahoo.com; Arulmozhichelvan, P. [Post Graduate and Research Department of Physics, Pachaiyappa' s College, Chennai 600030 (India); Jayavel, R. [Crystal Growth Centre, Anna University, Chennai 600025 (India)

    2008-01-15

    A new semiorganic nonlinear optical rubidium bis-DL-malato borate (RBMB) has been synthesized and single crystals were grown by slow cooling technique from aqueous solution. The grown crystals have been characterized by X-ray diffraction (single crystal XRD) to confirm the formation of the crystalline phases. FT-IR and FT-Raman spectroscopic analyses confirm the presence of all the functional groups in the grown crystals. TG-DTA studies reveal that the material is stable up to 230 deg. C. The UV-vis transmission spectrum shows a lower cutoff wavelength of 230 nm. The emission of SHG using Nd:YAG laser is confirmed by a modified Kurtz and Perry powder setup.

  3. Dispersive waves induced by self-defocusing temporal solitons in a beta-barium-borate crystal.

    Science.gov (United States)

    Zhou, Binbin; Bache, Morten

    2015-09-15

    We experimentally observe dispersive waves in the anomalous dispersion regime of a beta-barium-borate (BBO) crystal, induced by a self-defocusing few-cycle temporal soliton. Together the soliton and dispersive waves form an energetic octave-spanning supercontinuum. The soliton was excited in the normal dispersion regime of BBO through a negative cascaded quadratic nonlinearity. Using pump wavelengths from 1.24 to 1.4 μm, dispersive waves are found from 1.9 to 2.2 μm, agreeing well with calculated resonant phase-matching wavelengths due to degenerate four-wave mixing to the soliton. We also observe resonant radiation from nondegenerate four-wave mixing between the soliton and a probe wave, which was formed by leaking part of the pump spectrum into the anomalous dispersion regime. We confirm the experimental results through simulations.

  4. Nonlinear optical properties of silver nanoparticles prepared in Ag doped borate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Adamiv, V.T. [Institute of Physical Optics, Dragomanov str. 23, Lviv 79005 (Ukraine); Bolesta, I.M. [Ivan Franko National University, Dragomanov str. 50, Lviv 79005 (Ukraine); Burak, Ya.V., E-mail: burak@ifo.lviv.ua [Institute of Physical Optics, Dragomanov str. 23, Lviv 79005 (Ukraine); Gamernyk, R.V.; Karbovnyk, I.D.; Kolych, I.I.; Kovalchuk, M.G.; Kushnir, O.O.; Periv, M.V. [Ivan Franko National University, Dragomanov str. 50, Lviv 79005 (Ukraine); Teslyuk, I.M. [Institute of Physical Optics, Dragomanov str. 23, Lviv 79005 (Ukraine)

    2014-09-15

    Nonlinear properties of Li{sub 2}B{sub 4}O{sub 7}:Ag borate glasses with “Li{sub 2}B{sub 4}O{sub 7}:Ag nanoparticles” interface region formed by thermal treatment in hydrogen atmosphere and in vacuum are investigated. From the results of plasmon absorption and normalized transmission measurements in Z-scan regime it was ascertained that “Li{sub 2}B{sub 4}O{sub 7}:AgNPs” interface region changes the character of nonlinear refraction of Li{sub 2}B{sub 4}O{sub 7}:Ag glass from negative to positive, and, due to plasmon resonance, increases significantly its nonlinear properties. In particular, the observed growth of nonlinear refractive index n{sub 2} is more than four orders of magnitude.

  5. Electrochemical passivation behaviour of nanocrystalline Fe80Si20 coating in borate buffer solution

    Indian Academy of Sciences (India)

    G Gupta; A P Moon; K Mondal

    2013-02-01

    Passivation behaviour of nanocrystalline coating (Fe80Si20) obtained by in situ mechanical alloying route is studied and compared with that of the commercial pure iron and cast Fe80Si20 in sodium borate buffer solution at two different pH values (7.7 and 8.4). The coating reveals single passivation at a pH of 7.7 and double stage passivity at a pH of 8.4. The first passive layer is due to the dissolution mechanism and second passivity is related to stable passivation. The cast sample shows single stage passivity in the solution of pH 8.4. The difference in the passivation behaviour for the cast alloy (Fe80Si20) and the coating is related to the presence of highly iron-enriched localized regions, formed during the processing stage of coating.

  6. Luminescence spectroscopy of rare earth-doped oxychloride lead borate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Pisarski, Wojciech A., E-mail: Wojciech.Pisarski@us.edu.p [University of Silesia, Institute of Chemistry, Szkolna 9, 40-007 Katowice (Poland); Pisarska, Joanna [University of Silesia, Institute of Chemistry, Szkolna 9, 40-007 Katowice (Poland); Lisiecki, RadosLaw [Institute of Low Temperature and Structure Research, Polish Academy of Sciences, Okolna 2, 50-422 WrocLaw (Poland); Grobelny, Lukasz [University of Silesia, Institute of Chemistry, Szkolna 9, 40-007 Katowice (Poland); Dominiak-Dzik, Grazyna; Ryba-Romanowski, Witold [Institute of Low Temperature and Structure Research, Polish Academy of Sciences, Okolna 2, 50-422 WrocLaw (Poland)

    2011-04-15

    Ln-doped oxychloride lead borate glasses were studied using luminescence spectroscopy. Rare earth ions were limited to trivalent Pr{sup 3+}, Tm{sup 3+}, Eu{sup 3+} and Er{sup 3+}. Luminescence spectra were registered, which correspond to {sup 3}P{sub 0}-{sup 3}H{sub 4} and {sup 1}D{sub 2}-{sup 3}H{sub 4} transitions of Pr{sup 3+}, {sup 1}G{sub 4}-{sup 3}H{sub 5} and {sup 1}G{sub 4}-{sup 3}F{sub 4} transitions of Tm{sup 3+}, {sup 5}D{sub 0}-{sup 7}F{sub J} (J=0, 1, 2, 3, 4) transitions of Eu{sup 3+} and {sup 4}S{sub 3/2},{sup 2}H{sub 11/2}-{sup 4}I{sub 15/2} and {sup 4}I{sub 13/2}-{sup 4}I{sub 15/2} transitions of Er{sup 3+}. Luminescence decays from the excited states of Ln{sup 3+} ions were analyzed in detail. The experimental results indicate that relatively high phonon energy of the host gives important contribution to the excited state relaxation of rare earth ions. - Research Highlights: {yields}Lead borate glasses modified by PbCl{sub 2} were synthesized. {yields}Luminescence of Pr{sup 3+}, Tm{sup 3+}, Eu{sup 3+} and Er{sup 3+} ions in multicomponent oxychloride glasses was registered. {yields}From decay curves luminescence lifetimes for the excited states of rare earth ions were determined. {yields}The relatively high phonon energy of the host gives important contribution to the excited state relaxation of rare earth ions.

  7. Conductivity and modulus formulation in lithium modified bismuth zinc borate glasses

    Science.gov (United States)

    Dahiya, Sajjan; Punia, R.; Murugavel, S.; Maan, A. S.

    2016-05-01

    The conductivity and modulus formulation in lithium modified bismuth zinc borate glasses with compositions xLi2O-(50-x) Bi2O3-10ZnO-40B2O3 has been studied in the frequency range 0.1 Hz-1.5 × 105 Hz in the temperature range 573 K-693 K. The temperature and frequency dependent conductivity is found to obey Jonscher's universal power law for all the studied compositions, the dc conductivity (σdc), crossover frequency (ωH), and frequency exponent (s) have been estimated from the fitting of the experimental data of ac conductivity with Jonscher's universal power law. Enthalpy to dissociate the cation from its original site next to a charge compensating centre (Hf) and enthalpy of migration (Hm) have been estimated. It has been observed that number of charge carriers and ac conductivity in the lithium modified bismuth zinc borate glasses increases with increase in Li2O content. Further, the conduction mechanism in the glass sample with x = 0 may be due to overlapping large polaron tunneling, whereas, conduction mechanism in other studied glass samples more or less follows diffusion controlled relaxation model. The ac conductivity is scaled using σdc and ωH as the scaling parameter and is found that these are suitable scaling parameter for conductivity scaling. Non-Debye type relaxation is found prevalent in the studied glass system. Scaling of ac conductivity as well as electric modulus confirms the presence of different type of conduction mechanism in the glass samples with x = 0 and 5 from other studied samples. The activation energy of relaxation (ER) and dc conductivity (Edc) are almost equal, suggesting that polarons/ions have to overcome same barrier while relaxing and conducting.

  8. Kinetics of fluorescence properties of Eu3+ion in strontium-aluminium-bismuth-borate glasses

    Institute of Scientific and Technical Information of China (English)

    M. Dhamodhara Naidu; D. Rajesh; A. Balakrishna; Y.C. Ratnakaram

    2014-01-01

    Eu3+doped strontium-aluminium-bismuth-borate glasses with the chemical composition (50–x)B2O3+20Bi2O3+7AlF3+8SrO+15SrF2+xEu2O3 (where x=0.1 mol.%, 0.5 mol.%, 1.0 mol.%and 1.5 mol.%) were prepared by the conventional melt quenching technique. Structural properties of the prepared glasses were analysed through X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and Raman spectral techniques. Thermal stability of glass was analysed by differential thermal analysis (DTA) curve. Photoluminescence characteristics were studied using excitation, emission spectra and decay curves of Eu3+doped strontium-aluminium-bismuth-borate glasses. The Judd-Ofelt (J-O) intensity parameters,Ωλ(λ=2, 4 and 6) were obtained using emission spectra and was used to identify the nature of Eu3+ions with their surrounding ligands. Using J-O parameters the tran-sition probabilities (A), stimulated emission cross-sections σEp , branching ratios (βR) and radiative lifetimes (τmeas and τcal) were evaluated for the 5D0→7FJ (J=0, 1, 2, 3 and 4) transition of Eu3+ions in the present glasses. The decay profiles were found to be non exponential for all the concentrations and the measured lifetimes (τmeas) were obtained from the decay profiles. The higher values of A,σEp ,βR and quantum efficiency (η) for 5D0→7F2 emission transition at 617 nm confirmed the present glass was as active medium for red laser emission applications.

  9. Advanced Detection Technology of Trace-level Borate for SG Leakage Monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Seban; Kang, Dukwon; Kim, Seungil; Kim, Hyunki; Heo, Jun; Sung, Jinhyun [Radiation Eng. Center, Shihung (Korea, Republic of); Lee, Dongbum [Academic Support Dept., Seoul (Korea, Republic of)

    2013-05-15

    Many studies have been reported for monitoring technology of steam generator, however, all of these methods have their own limitations. The leakage monitoring technology of steam generator of PWR has also got a limit due to the adoption of specific radionuclides (N-16, Ar-41, H-3, Xe, etc.) generated by nuclear fission, which are available only when reactor output is 20% or more. Most of domestic NPPs apply the N-16 technique for monitoring tube leakage but it has some problem that it is difficult to calculate the leakage rate because neutron flux are not completely formed during low power operation. For example, tube leakage of steam generator occurred in the Uljin nuclear power plant in 2002 during coast down operation for periodic plant maintenance. This plant could not prevent a rupture accident in advance because N-16 method is not possible the leak monitoring less than 20% reactor power. The development of excellent alternative monitoring technology that can monitor the real-time leakage is required under a variety of operating conditions like start-up and abnormal conditions of NPPs. This study was performed to lay a foundation in monitoring the leakage of steam generator coping with the lower output and low power operational condition using trace level of boron which is non-radioactive nuclide to inject control neutron injection. In this study, non-radioactive nuclide boron ion, which existed in the secondary system water, as leakage monitoring indicator was investigated for the separation of complex cation and anion phase. Borate was detected by using borate concentrator column coupled with the ion-exclusion column analytical column, revealing the problem of overlapped peak between fluoride and boron ions. Meanwhile, ion-exchange column could confirm the possibility as a leakage monitoring indicator of steam generator, despite the peak of glycolic acid salts was slightly overlapped. It will be needed for further research regarding the selectivity of the

  10. In situ hydroxyapatite nanofiber growth on calcium borate silicate ceramics in SBF and its structural characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Pu, Yinfu; Huang, Yanlin; Qi, Shuyun [College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123 (China); Chen, Cuili [Department of Physics and Interdisciplinary Program of Biomedical, Mechanical & Electrical Engineering, Pukyong National University, Busan 608-737 (Korea, Republic of); Seo, Hyo Jin, E-mail: hjseo@pknu.ac.kr [Department of Physics and Interdisciplinary Program of Biomedical, Mechanical & Electrical Engineering, Pukyong National University, Busan 608-737 (Korea, Republic of)

    2015-10-01

    A novel calcium silicate borate Ca{sub 11}Si{sub 4}B{sub 2}O{sub 22} ceramic was firstly prepared by the conventional solid-state reaction. In vitro hydroxyapatite mineralization was investigated by soaking the ceramics in simulated body fluid (SBF) solutions at body temperature (37 °C) for various time periods. Scanning electron microscopy (SEM) and X-ray diffraction analysis (XRD) measurements were applied to investigate the samples before and after the immersion of ceramics in SBF solution. The elemental compositions of a hydroxyapatite layer on the ceramics during the mineralization were confirmed by X-ray energy-dispersive spectra (EDS). Meanwhile, the bending strength and elastic modulus of Ca{sub 11}Si{sub 4}B{sub 2}O{sub 22} ceramics were also measured, which indicate that the biomaterials based on Ca{sub 11}Si{sub 4}B{sub 2}O{sub 22} ceramics possess bioactivity and might be a potential candidate as biomaterials for hard tissue repair. The bioactive mineralization ability was evaluated on the base of its crystal structural characteristics, i.e., silanol (Si–OH) and B–OH groups can be easily induced on the surface of Ca{sub 11}Si{sub 4}B{sub 2}O{sub 22} ceramics soaked in SBF solutions. - Highlights: • Calcium silicate borate Ca{sub 11}Si{sub 4}B{sub 2}O{sub 22} ceramics were developed as a new biomaterial. • Ca{sub 11}Si{sub 4}B{sub 2}O{sub 22} shows a superior in vitro bioactivity by inducing bone-like apatite. • Ca{sub 11}Si{sub 4}B{sub 2}O{sub 22} has good mechanical properties as potential candidate biomaterials. • The structure with SiO{sub 4} and BO{sub 3} groups is favorable for hydroxyapatite formation.

  11. Interstitial incorporation of plutonium into a low-dimensional potassium borate.

    Science.gov (United States)

    Wang, Shuao; Diwu, Juan; Simonetti, Antonio; Booth, Corwin H; Albrecht-Schmitt, Thomas E

    2011-11-01

    The molten boric acid flux reaction of PuBr(3) with KBO(2) at 200 °C results in the formation of large light-yellow crystals of K[B(5)O(7)(OH)(2)]·H(2)O:Pu(4+). Single-crystal X-ray diffraction experiments on the Pu-doped K[B(5)O(7)(OH)(2)]·H(2)O demonstrate two features: (1) K[B(5)O(7)(OH)(2)]·H(2)O:Pu(4+) adopts a one-dimensional borate chain structure with void spaces between the chains. (2) The doping plutonium atoms do not reside on the potassium sites. The latter are not fully occupied. Both laser-ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) and energy-dispersive spectrometry analyses indicate that plutonium atoms are uniformly distributed in crystals of K[B(5)O(7)(OH)(2)]·H(2)O with an atomic K:Pu ratio of approximately 65:1 measured by LA-ICP-MS. UV-vis-NIR spectra taken from both freshly made and one day old crystals show that the plutonium present within the crystals is predominantly characterized by Pu(IV). A small amount of Pu(III) is also present initially, but slowly oxidized to Pu(IV) via interaction with oxygen in the air. X-ray absorption near-edge structure and extended X-ray absorption fine structure spectroscopic measurements confirm that plutonium is mainly present as a form similar to that of a PuO(2) cluster. The combined results suggest that the clusters containing Pu(IV) ions are uniformly distributed in the void spaces between the borate chains.

  12. Particulate emissions from residential wood combustion

    DEFF Research Database (Denmark)

    Luis Teles de Carvalho, Ricardo; Jensen, Ole Michael; Tarelho, Luis A. C.

    Residential wood combustion (RWC) in fireplaces and conventional appliances is the main contributor to fine particulate matter (PM2.5) emissions in Denmark and Portugal representing more than 30% of the total emissions [1;2]. Such estimations are uncertain concerning the wood consumption and offi......Residential wood combustion (RWC) in fireplaces and conventional appliances is the main contributor to fine particulate matter (PM2.5) emissions in Denmark and Portugal representing more than 30% of the total emissions [1;2]. Such estimations are uncertain concerning the wood consumption.......5 emissions within a specific “wood burning living area”, but one Danish study exists [4]. In previous inventories distinct combustion air operation modes and the growing penetration of automate wood-burning stoves have not been considered. The present work aims to discuss opportunities for improving...... Portuguese combustion practices in laboratory tests. This study highlights that the previous PM2.5 emission inventories in Denmark and Portugal did not consider the possible variations on fuel moisture, dimensions of wood-logs and air-inlet operation patterns, although they are very important, especially...

  13. Propagation behavior of acoustic wave in wood

    Institute of Scientific and Technical Information of China (English)

    Huadong Xu; Guoqi Xu; Lihai Wang; Lei Yu

    2014-01-01

    We used acoustic tests on a quarter-sawn poplar timbers to study the effects of wood anisotropy and cavity defects on acoustic wave velocity and travel path, and we investigated acoustic wave propagation behavior in wood. The timber specimens were first tested in unmodified condition and then tested after introduction of cavity defects of varying sizes to quantify the transmitting time of acoustic waves in laboratory conditions. Two-dimensional acoustic wave contour maps on the radial section of specimens were then simulated and analyzed based on the experimental data. We tested the relationship between wood grain and acoustic wave velocity as waves passed in various directions through wood. Wood anisotropy has significant effects on both velocity and travel path of acoustic waves, and the velocity of waves passing longitudinally through timbers exceeded the radial velocity. Moreover, cavity defects altered acoustic wave time contours on radial sections of timbers. Acous-tic wave transits from an excitation point to the region behind a cavity in defective wood more slowly than in intact wood.

  14. Utilisation of Estonian energy wood resources

    Energy Technology Data Exchange (ETDEWEB)

    Muiste, P.; Tullus, H.; Uri, V. [Estonian Agricultural University, Tartu (Estonia)

    1996-12-31

    In the end of the Soviet period in the 1980s, a long-term energy programme for Estonia was worked out. The energy system was planned to be based on nuclear power and the share of domestic alternative sources of energy was low. The situation has greatly changed after the re-establishment of the Estonian independence, and now wood and peat fuels play an important role in the energy system. Energy consumption in Estonia decreased during the period 1970-1993, but this process has less influenced the consumption of domestic renewable fuels - peat and wood. It means that the share of these fuels has grown. The investment on substitution of imported fossil fuels and on conversion of boiler plants from fossil fuels to domestic fuels has reached the level of USD 100 million. The perspectives of the wood energy depend mainly on two factors; the resources and the price of wood energy compared with other fuels. The situation in wood market influences both the possible quantities and the price. It is typical that the quickly growing cost of labour power in Estonia is greatly affecting the price of energy wood. Though the price level of fuel peat and wood chips is lower than the world market price today, the conditions for using biofuels could be more favourable, if higher environmental fees were introduced. In conjunction with increasing utilisation of biofuels it is important to evaluate possible emissions or removal of greenhouse gases from Estonian forests 3 refs.

  15. Solvolytic liquefaction of wood under mild conditions

    Energy Technology Data Exchange (ETDEWEB)

    Yu, S.M.

    1982-04-01

    Conversion of wood to liquid products requires cleavage of bonds which crosslink the wood structure. This study examines a low-severity wood solubilization process utilizing a solvent medium consisting of a small amount of sulfuric acid and a potentially wood-derivable alcohol. In one half hour of reaction time at 250/sup 0/C under 15 psia starting nitrogen pressure, over 95% of the wood (maf) was rendered acetone-soluble. The product is a soft, black, bitumen-like solid at room temperature but readily softens at 140/sup 0/C. Between 25 and 50% of the original wood oxygen, depending on alcohol used, was removed as water. Approximately 2 to 17% of the alcohols were retained in the product. Gel permeation chromatography showed that the product's median molecular weight is around 300. Based on experimental and literature results, a mechanism for wood solubilization is proposed. This involves protonation of the etheric oxygen atoms, leading to subsequent bond scission to form carbonium ions which are stabilized by solvent alkoxylation. At severe conditions, polymerization and condensation reactions result in acetone-insoluble materials.

  16. Towards a worldwide wood economics spectrum.

    Science.gov (United States)

    Chave, Jerome; Coomes, David; Jansen, Steven; Lewis, Simon L; Swenson, Nathan G; Zanne, Amy E

    2009-04-01

    Wood performs several essential functions in plants, including mechanically supporting aboveground tissue, storing water and other resources, and transporting sap. Woody tissues are likely to face physiological, structural and defensive trade-offs. How a plant optimizes among these competing functions can have major ecological implications, which have been under-appreciated by ecologists compared to the focus they have given to leaf function. To draw together our current understanding of wood function, we identify and collate data on the major wood functional traits, including the largest wood density database to date (8412 taxa), mechanical strength measures and anatomical features, as well as clade-specific features such as secondary chemistry. We then show how wood traits are related to one another, highlighting functional trade-offs, and to ecological and demographic plant features (growth form, growth rate, latitude, ecological setting). We suggest that, similar to the manifold that tree species leaf traits cluster around the 'leaf economics spectrum', a similar 'wood economics spectrum' may be defined. We then discuss the biogeography, evolution and biogeochemistry of the spectrum, and conclude by pointing out the major gaps in our current knowledge of wood functional traits.

  17. Inspecting wood surface roughness using computer vision

    Science.gov (United States)

    Zhao, Xuezeng

    1995-01-01

    Wood surface roughness is one of the important indexes of manufactured wood products. This paper presents an attempt to develop a new method to evaluate manufactured wood surface roughness through the utilization of imaging processing and pattern recognition techniques. In this paper a collimated plane of light or a laser is directed onto the inspected wood surface at a sharp angle of incidence. An optics system that consists of lens focuses the image of the surface onto the objective of a CCD camera, the CCD camera captures the image of the surface and using a CA6300 board digitizes the image. The digitized image is transmitted into a microcomputer. Through the use of the methodology presented in this paper, the computer filters the noise and wood anatomical grain and gives an evaluation of the nature of the manufactured wood surface. The preliminary results indicated that the method has the advantages of non-contact, 3D, high-speed. This method can be used in classification and in- time measurement of manufactured wood products.

  18. Wood quality changes caused by mineral fertilization

    Directory of Open Access Journals (Sweden)

    Carlos Roberto Sette Jr

    2014-06-01

    Full Text Available The diverse and important use of wood from fast growth eucalyptus plantations requires the analysis of the effect of mineral fertilizers on wood quality. The objective of this study was to evaluate the anatomical characteristics and wood density from Eucalyptus grandis trees (3 m x 2 m spacing fertilized with potassium and sodium (at planting, 6 th and 12th month. Fifteen (15 6 years old eucalyptus trees were selected (5 trees/treatment, cut and wood samples at DBH (1,3 m were taken for anatomical characteristics (fiber and vessels and wood density analysis. Results showed that eucalyptus trees treated with mineral fertilizers did not show significant alteration in average wood density, with radial profile model common to all three treatments, characterized by a values increase in the region next to the pith, toward to bark. Mineral fertilization influenced wood anatomical characteristics: treatment with sodium was characterized by thinner walls and lumen larger diameter; in treatment with potassium, larger vessels were detected.

  19. Retention of Root Canal Posts

    DEFF Research Database (Denmark)

    Sahafi, A; Benetti, Ana Raquel; Flury, S;

    2015-01-01

    The aim of this study was to investigate the effect of the cement film thickness of a zinc phosphate or a resin cement on retention of untreated and pretreated root canal posts. Prefabricated zirconia posts (CosmoPost: 1.4 mm) and two types of luting cements (a zinc phosphate cement [DeTrey Zinc......] and a self-etch adhesive resin cement [Panavia F2.0]) were used. After removal of the crowns of 360 extracted premolars, canines, or incisors, the root canals were prepared with a parallel-sided drill system to three different final diameters. Half the posts did not receive any pretreatment. The other half...... received tribochemical silicate coating according to the manufacturer's instructions. Posts were then luted in the prepared root canals (n=30 per group). Following water storage at 37°C for seven days, retention of the posts was determined by the pull-out method. Irrespective of the luting cement...

  20. To immobilize polyethylene glycol-borate ester/lithium fluoride in graphene oxide/poly(vinyl alcohol) for synthesizing new polymer electrolyte membrane of lithium-ion batteries

    OpenAIRE

    Huang, Y.F.; Zhang, M. Q.; M. Z. Rong; W. H. Ruan

    2017-01-01

    Polymer electrolyte membranes (PEMs) are potentially applicable in lithium-ion batteries with high safety, low cost and good performance. Here, to take advantages of ionic conductivity and selectivity of borate ester-functionalized small molecules as well as structural properties of polymer nanocomposite, a strategy of immobilizing as-synthesized polyethylene glycol-borate ester/lithium fluoride (B-PEG/LiF) in graphene oxide/poly(vinyl alcohol) (GO/PVA) to prepare a PEM is put forward. Chemic...

  1. Hydrologic Analysis of Fort Leonard Wood, Missouri

    Science.gov (United States)

    2015-08-01

    balance concept. 1.3 Fort Leonard Wood, MO, case study Fort Leonard Wood (FLW), MO, is the first installation case study for the developing NZI tool...20314-1000 Under Work Units 8609C7, BH01K8, and LG7452 ERDC TR-15-4 ii Abstract This report analyzes the hydrologic ability of Fort Leonard Wood... work was carried out in the second year of a 4-year program that is building on Net Zero Energy to tackle the more complicated problem of reducing

  2. Mathematical modelling of wood and briquettes torrefaction

    Energy Technology Data Exchange (ETDEWEB)

    Felfli, Felix Fonseca; Luengo, Carlos Alberto [Universidade Estadual de Campinas (UNICAMP), SP (Brazil). Inst. de Fisica Gleb Wataghin. Grupo Combustiveis Alternativos; Soler, Pedro Beaton [Universidad de Oriente, Santiago de Cuba (Cuba). Fac. de Ingenieria Mecanica. Centro de Estudios de Eficiencia Energetica; Rocha, Jose Dilcio [Universidade Estadual de Campinas (UNICAMP), SP (Brazil). Nucleo Interdisciplinar de Planejamento Energetico (NIPE)

    2004-07-01

    A mathematical model valid for the torrefaction of wood logs and biomass briquettes is presented. The model described both chemical and physical processes, which take place in a moist piece of wood heated at temperatures between 503 and 573 K. Calibration measurements of the temperature profile and mass loss, were performed on dry cylinders of wood samples during torrefaction in an inert atmosphere at 503, 533, and 553 K. The calculated data shows a good agreement with experiments. The model can be a useful tool to estimate projecting and operating parameters for torrefaction furnaces such as minimum time of torrefaction, energy consumption and the mass yield. (author)

  3. Overview of Wood-based Panel Industry in China

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The production of wood-based panel was presented firstly in this paper. Some features of China’s wood-based panel industry were reviewed, including production bases, raw materials and main markets of wood-based panel. In addition, the trade flow of wood-based panel was described in the end.

  4. The vessels in the wood of Javan Mangrove trees

    NARCIS (Netherlands)

    Janssonius, H.H.

    1950-01-01

    In the course of my study on the wood-anatomy of Javan woods (Mikrographie des Holzes der auf Java vorkommenden Baumarten), I examined also many woods from mangrove-trees. Mangrove has been the subject of much investigation; the community is usually described as xeromorphic. Mangrove woods proved to

  5. Finite Element Analysis Of Boron Diffusion In Wood

    DEFF Research Database (Denmark)

    Krabbenhøft, Kristian; Hoffmeyer, Preben; Bechgaard, Carl;

    2002-01-01

    The coupled heat and mass transfer equations for air, water and heat transfer are supplemented with a conservation equation for an additional species representing the concentration of boron in wood. Boundary conditions for wood-air. wood-soil and wood-boron interfaces arc discussed and finally th...

  6. An Overview of the Biology of Reaction Wood Formation

    Institute of Scientific and Technical Information of China (English)

    Sheng Du; Fukuju Yamamoto

    2007-01-01

    Reaction wood possesses altered properties and performs the function of regulating a tree's form, but it is a serious defect in wood utility. Trees usually develop reaction wood in response to a gravistimulus. Reaction wood in gymnosperms is referred to as compression wood and develops on the lower side of leaning stems or branches.In arboreal, dicotyledonous angiosperms, however, it is called tension wood and is formed on the upper side of the leaning. Exploring the biology of reaction wood formation is of great value for the understanding of the wood differentiation mechanisms, cambial activity, gravitropism, and the systematics and evolution of plants. After giving an outline of the variety of wood and properties of reaction wood, this review lays emphasis on various stimuli for reaction wood induction and the extensive studies carried out so far on the roles of plant hormones in reaction wood formation. Inconsistent results have been reported for the effects of plant hormones. Both auxin and ethylene regulate the formation of compression wood in gymnosperms. However, the role of ethylene may be indirect as exogenous ethylene cannot induce compression wood formation. Tension wood formation is mainly regulated by auxin and gibberellin. Interactions among hormones and other substances may play important parts in the regulation of reaction wood formation.

  7. Coal and wood fuel for electricity production: An environmentally sound solution for waste and demolition wood

    Energy Technology Data Exchange (ETDEWEB)

    Penninks, F.W.M. [EPON, Zwolle (Netherlands)

    1997-12-31

    Waste wood from primary wood processing and demolition presents both a problem and a potential. If disposed in landfills, it consumes large volumes and decays, producing CH{sub 4}, CO{sub 2} and other greenhouse gases. As an energy source used in a coal fired power plant it reduces the consumption of fossil fuels reducing the greenhouse effect significantly. Additional advantages are a reduction of the ash volume and the SO{sub 2} and NO{sub x} emissions. The waste wood requires collection, storage, processing and burning. This paper describes a unique project which is carried out in the Netherlands at EPON`s Gelderland Power Plant (635 MW{sub e}) where 60 000 tonnes of waste and demolition wood will be used annually. Special emphasis is given to the processing of the powdered wood fuel. Therefore, most waste and demolition wood can be converted from an environmental liability to an environmental and economic asset. (author)

  8. Non-malignant respiratory diseases and occupational exposure to wood dust. Part II. Dry wood industry.

    Science.gov (United States)

    Jacobsen, Gitte; Schaumburg, Inger; Sigsgaard, Torben; Schlunssen, Vivi

    2010-01-01

    This paper reviews the literature on associations between dry wood dust exposure and non-malignant respiratory diseases. Criteria for inclusion are epidemiological studies in English language journals with an internal or external control group describing relationships between dry wood dust exposure and respiratory diseases or symptoms. Papers took into consideration smoking and when dealing with lung function age. A total of 37 papers forms the basis of this review. The results support an association between dry wood dust exposure and asthma, asthma symptoms, coughing, bronchitis, and acute and chronic impairment of lung function. In addition, an association between wood dust exposure and rhino-conjunctivitis is seen across the studies. Apart from plicatic acid in western red cedar wood, no causal agent has consistently been disclosed. Type 1 allergy is not suspected to be a major cause of wood dust induced asthma.

  9. Underground riparian wood: Buried stem and coarse root structures of Black Poplar (Populus nigra L.)

    Science.gov (United States)

    Holloway, James V.; Rillig, Matthias C.; Gurnell, Angela M.

    2017-02-01

    Despite the potential importance of tree species in influencing the processes of wood recruitment, transport, retention, and decay that control river wood budgets, focus has been relatively limited on this theme within fluvial wood research. Furthermore, one of the least investigated topics is the belowground living wood component of riparian trees. This paper presents observations of the morphology and age of buried stem and coarse root structures of eight Populus nigra individuals located in the riparian woodland of two sites on the middle to lower Tagliamento River, Italy. This species was selected because of its wide distribution along European rivers and its frequent dominance of riparian woodland. Each tree was excavated by hand to expose a minimum of half of the root system with complete exposure of the main axis. Smaller roots were then removed and larger protruding roots cut back to permit access to the main axis. The excavated structures were photographed from multiple angles for photogrammetric modelling; the structure and character of the exposed sediments around the tree's main axis were recorded; and wood samples were taken from the main aboveground stem(s), sections of the main buried axis, and major roots for dendrochronological analysis. Results from these field observations and laboratory dating of the wood samples were combined to describe the belowground morphology of each tree and to draw inferences concerning the impact of fluvial disturbances. Common features of these excavated structures included: (i) rooting depths to below the bar surface where the original tree established, with many young roots also existing at depth; (ii) translocation of the main buried axis in a downstream direction; (iii) a main buried axis comprised mainly of stems that have become buried and then generated new shoots, including multistem patches, and adventitious roots; (iv) the presence of steps and bends in the main buried axis associated with the generation of

  10. Ca3Na4LiBe4B10O24F: a new beryllium borate with a unique beryl borate ∞(2)[Be8B16O40F2] layer intrabridged by [B12O24] groups.

    Science.gov (United States)

    Luo, Siyang; Yao, Wenjiao; Gong, Pifu; Yao, Jiyong; Lin, Zheshuai; Chen, Chuangtian

    2014-08-18

    A novel beryllium borate, Ca3Na4LiBe4B10O24F, has been discovered. It possesses a unique ∞(2)[Be8B16O40F2] layer composed of two opposite parallel [Be4B4O12F]∞ layers bridged with [B12O24] polyborates. The linkage of [B12O24] to other structural units is first found in anhydrous borates. In the ∞(2)[Be8B16O40F2] layer, multiple tunnels are arranged along different directions resided by the alkali and alkaline-earth cations. The compound remains stable in an ambient atmosphere from room temperature to the melting point at 830 °C and melts incongruently.

  11. LCA-based optimization of wood utilization under special consideration of a cascading use of wood.

    Science.gov (United States)

    Höglmeier, Karin; Steubing, Bernhard; Weber-Blaschke, Gabriele; Richter, Klaus

    2015-04-01

    Cascading, the use of the same unit of a resource in multiple successional applications, is considered as a viable means to improve the efficiency of resource utilization and to decrease environmental impacts. Wood, as a regrowing but nevertheless limited and increasingly in demand resource, can be used in cascades, thereby increasing the potential efficiency per unit of wood. This study aims to assess the influence of cascading wood utilization on optimizing the overall environmental impact of wood utilization. By combining a material flow model of existing wood applications - both for materials provision and energy production - with an algebraic optimization tool, the effects of the use of wood in cascades can be modelled and quantified based on life cycle impact assessment results for all production processes. To identify the most efficient wood allocation, the effects of a potential substitution of non-wood products were taken into account in a part of the model runs. The considered environmental indicators were global warming potential, particulate matter formation, land occupation and an aggregated single score indicator. We found that optimizing either the overall global warming potential or the value of the single score indicator of the system leads to a simultaneous relative decrease of all other considered environmental impacts. The relative differences between the impacts of the model run with and without the possibility of a cascading use of wood were 7% for global warming potential and the single score indicator, despite cascading only influencing a small part of the overall system, namely wood panel production. Cascading led to savings of up to 14% of the annual primary wood supply of the study area. We conclude that cascading can improve the overall performance of a wood utilization system.

  12. Influence des ions lithium et borate sur l'hydratation de ciments sulfo-alumineux : application au conditionnement de résines échangeuses d'ions boratées

    OpenAIRE

    2015-01-01

    In pressurized water reactors, a solution of boric acid, the pH of which is controlled by the addition of lithium hydroxide, is injected in the primary circuit. Boron acts as a neutron moderator and helps controlling the fission reactions. The primary coolant is purified by flowing through columns of ion exchange resins. These resins are periodically renewed and constitute a low-level radioactive waste. In addition to radionuclides, they mainly contain borate and lithium ions. They are curren...

  13. Wood anatomy and wood density in shrubs: Responses to varying aridity along transcontinental transects.

    Science.gov (United States)

    Martínez-Cabrera, Hugo I; Jones, Cynthia S; Espino, Susana; Schenk, H Jochen

    2009-08-01

    Wood density plays a key role in ecological strategies and life history variation in woody plants, but little is known about its anatomical basis in shrubs. We quantified the relationships between wood density, anatomy, and climate in 61 shrub species from eight field sites along latitudinal belts between 31° and 35° in North and South America. Measurements included cell dimensions, transverse areas of each xylem cell type and percentage contact between different cell types and vessels. Wood density was more significantly correlated with precipitation and aridity than with temperature. High wood density was achieved through reductions in cell size and increases in the proportion of wall relative to lumen. Wood density was independent of vessel traits, suggesting that this trait does not impose conduction limitations in shrubs. The proportion of fibers in direct contact with vessels decreased with and was independent of wood density, indicating that the number of fiber-vessel contacts does not explain the previously observed correlation between wood density and implosion resistance. Axial and radial parenchyma each had a significant but opposite association with wood density. Fiber size and wall thickness link wood density, life history, and ecological strategies by controlling the proportion of carbon invested per unit stem volume.

  14. Effects of Mixing Temperature and Wood Powder Size on Mechanical Properties of Wood Plastic Recycled Composite

    Science.gov (United States)

    Miki, Tsunehisa; Sugimoto, Hiroyuki; Kojiro, Keisuke; Kanayama, Kozo; Yamamoto, Ken

    In this study, wood (cedar) powder ranging from 53 µm to 1 mm sizes, recycled polypropylene (PP) / polyethylene (PE) and acid-modified PP as a compatibilization agent were used to produce a wood-plastic recycled composite (WPRC). For discussing the effects of the wood powder sizes on the mechanical properties of the WPRC, a mixing process of the wood powder and the plastics in a constant wood content of 50% weight was firstly performed by a mixing machine controlled temperature and rotation of mixing blade. And then, to obtain WPRC panels the wood and plastics mixtures were compressed in a mould under a constant pressure and a temperature for a certain holding time. WPRC specimens for mechanical tests were cut from the WPRC panels, and a tensile strength and a size-stability were acquired. The results show that the successful mixing process runs above 180°C, where the mixing torque required compounding keeps constant or slightly increases. The tensile strength of the WPRC increases when the smaller size of wood powder is used for wood/plastic compound under successful mixing conditions. It is shown from thickness change rate of specimens that mixing temperature of wood/plastic compound affects a size stability of the WPRC.

  15. The economic potential of wood pellet production from alternative, low-value wood sources in the southeast of the US

    NARCIS (Netherlands)

    Hoefnagels, Ric; Junginger, Martin; Faaij, Andre

    2014-01-01

    The global demand for wood pellets used for energy purposes is growing. Therefore, increased amounts of wood pellets are produced from primary forestry products, such as pulp wood. The present analysis demonstrates that substantial amounts of alternative, low-value wood resources are available that

  16. Wood recognition using image texture features.

    Directory of Open Access Journals (Sweden)

    Hang-jun Wang

    Full Text Available Inspired by theories of higher local order autocorrelation (HLAC, this paper presents a simple, novel, yet very powerful approach for wood recognition. The method is suitable for wood database applications, which are of great importance in wood related industries and administrations. At the feature extraction stage, a set of features is extracted from Mask Matching Image (MMI. The MMI features preserve the mask matching information gathered from the HLAC methods. The texture information in the image can then be accurately extracted from the statistical and geometrical features. In particular, richer information and enhanced discriminative power is achieved through the length histogram, a new histogram that embodies the width and height histograms. The performance of the proposed approach is compared to the state-of-the-art HLAC approaches using the wood stereogram dataset ZAFU WS 24. By conducting extensive experiments on ZAFU WS 24, we show that our approach significantly improves the classification accuracy.

  17. Plasma impregnation of wood with fire retardants

    Science.gov (United States)

    Pabeliña, Karel G.; Lumban, Carmencita O.; Ramos, Henry J.

    2012-02-01

    The efficacy of chemical and plasma treatments with phosphate and boric compounds, and nitrogen as flame retardants on wood are compared in this study. The chemical treatment involved the conventional method of spraying the solution over the wood surface at atmospheric condition and chemical vapor deposition in a vacuum chamber. The plasma treatment utilized a dielectric barrier discharge ionizing and decomposing the flame retardants into innocuous simple compounds. Wood samples are immersed in either phosphoric acid, boric acid, hydrogen or nitrogen plasmas or a plasma admixture of two or three compounds at various concentrations and impregnated by the ionized chemical reactants. Chemical changes on the wood samples were analyzed by Fourier transform infrared spectroscopy (FTIR) while the thermal changes through thermo gravimetric analysis (TGA). Plasma-treated samples exhibit superior thermal stability and fire retardant properties in terms of highest onset temperature, temperature of maximum pyrolysis, highest residual char percentage and comparably low total percentage weight loss.

  18. Supply of Rubber Wood Log in Malaysia

    Directory of Open Access Journals (Sweden)

    A. W. Noraida

    2014-06-01

    Full Text Available Issue on shortage of raw material for wood processing solved by discovery of rubber wood log as one of the substitutes the natural log. This paper examines the supply of rubber wood log in Malaysia. We employ ARDL Bound Approach Test and time series data from 1980 to 2010 which represented the whole Malaysia are used to achieve the established objectives. The result shown, in the long run harvested area and wages have 1% and 10% significant level respectively. While in the short run, there was only harvested area having an impact with 1% significant level. This result indicates that, the harvested area become the most impact towards supply of rubber wood log either in short run or in the long run. While wages as input cost gave less impact in another word it become unburden to the producers.

  19. ROUGHNESS ON WOOD SURFACES AND ROUGHNESS MEASUREMENT METHODS

    OpenAIRE

    İsmail Aydın; Gürsel Çolakoğlu

    2003-01-01

    Some visual characteristics of wood such as color, pattern and texture determine the quality of manufactured products. Surface properties of wood material are important both in production and marketing after production. Initial studies related to the roughness of wood surface were begun in early 1950’s. However, no general agreed standardization can not have been developed for wood surfaces. Surface roughness of wood is function of the production process, product type and the natural anatomic...

  20. Effect of Wood Particle Size on the Properties of Wood/Polypropylene Composites Ⅰ:Mechanical Properties

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The mechanical properties of wood powder/polypropy!ene composites with different wood particle sizes and wood species have been studied. All of the wood particie sizes increased the E-modulus of the composites. Tensile tests showed that wood partide sizes had a negative effect on the elongation at break and the tensile strength of the composites has been improved when wood particle sizes were be(ow 150 μm (below 100 mesh). For the impact tests, the wood partide sizes had a negative effect, but the MDF f...

  1. 硼酸木材防虫剂预防建筑物白蚁药效研究%Efficacy of boric acid wood preservative against termite in buildings

    Institute of Scientific and Technical Information of China (English)

    尹红; 隋晓斐

    2011-01-01

    Objective To measure the efficacy of boric acid wood preservatives in the prevention of Coptotermes formosanus (Shiraki) and Reticulitermes speratus (Kolbe) in buildings. Methods A cohort of C. formosanus or R. speratus were subject to timbers or wood blocks treated with 5% or 10% borate preservative by painting or dipping to determine the respective toxicity and residual effect. Results Borate treated wood demonstrated a good resistance effect against C. formosanus and R. speratus, which were dead at both concentrations with either wood treatment approach. C. formosanus were more susceptible to the agent as the subjects demonstrated shorter survival duration. All subjects of C. formosanus died in ( 12.6 ± 2.4) days and all R. speratus in (16.8 ± 1.7)days as exposed to wood without ageing, both shorter than the time for death of the groups exposed to wood after ageing, (19.1 ±2.7) days for C. formosanus and (21.8±5.0) days for R. speratus, respectively. The death rate of the control group was lower than 0.1%. C. formosanus was more susceptible to boric acid in view of the resistance effect, as the intactness index of each piece of borate treated wood in that group was higher than 90. The intactness index of wood treated in 5% by painting or 10% agent by either painting or dipping, with or without ageing, remained above 90. In contrast, wood in the control group was seriously damaged with the intactness index as low as 60 and 40, respectively. It was suggested that borate treated wood had satisfyingly stable and long-last toxicity against termites, which was not compromised by ageing. Conclusion Borate wood preservative can be used for wood treatment for effective termite prevention in buildings.%目的 研究硼酸木材防护剂对危害建筑物的台湾乳白蚁和栖北散白蚁的预防效果.方法 用涂刷法和浸泡法处理木材,然后采用群体法测定5%和10%浓度的药液对台湾乳白蚁和栖北散白蚁的毒效

  2. Systematic wood anatomy of the Rosaceae

    OpenAIRE

    Zhang, Shu-Yin

    1992-01-01

    The wood anatomy of the Rosaceae is surveyed and analysed, based on the study of 280 species (c. 500 specimens) belonging to 62 genera from different parts of the world. Eighteen wood anatomical characters have been used for a phenetic and phylogenetic classification. In the phenetic classification, 12 groups are recognised and compared with Hutchinson’s tribes. Groups I-V accommodate a mixture of representatives from Spiraeoideae and Rosoideae genera (or tribes); Groups VI-VII comprise the M...

  3. Infrared-to-visible conversion luminescence of Er 3+ ions in lead borate transparent glass-ceramics

    Science.gov (United States)

    Pisarski, Wojciech A.; Pisarska, Joanna; Lisiecki, Radosław; Grobelny, Łukasz; Dominiak-Dzik, Grażyna; Ryba-Romanowski, Witold

    2009-10-01

    Transparent glass-ceramics were successfully prepared during controlled heat treatment of lead borate glasses. The PbF 2 particles were dispersed into a borate glass matrix which was evidenced by X-ray diffraction analysis. The phase identification revealed that crystalline peaks can be related to the orthorhombic PbF 2 phase. Green up-conversion luminescence due to the 4S 3/2- 4I 15/2 transition of Er 3+ ions was registered. In comparison to the precursor glass the luminescence intensity was considerably higher, whereas the luminescence linewidth slightly decreased in the studied oxyfluoride transparent glass-ceramics. It indicated that a part of the trivalent erbium was incorporated into the PbF 2 crystalline phase.

  4. Molecular Dynamics Simulation of Lead Borate and Related Glasses in Multicomponent Systems for Low Melting Vitrification of Nuclear Wastes

    Science.gov (United States)

    Kato, S.; Sakida, S.; Benino, Y.; Nanba, T.

    2011-03-01

    Glasses based on lead oxide have excellent properties in general such as low melting point, high chemical durability and high stability of glassy form, which are suitable for the preservation of volatile nuclear wastes in a permanent vitrified form. In order to confirm the long-term performance of lead borate based glasses it is necessary to establish dissolution and diffusion processes based on a reliable model of the glass structure. In the present study molecular dynamics (MD) simulation of lead borate based glasses was carried out introducing a dummy negative point charge to reproduce asymmetric PbOn units. Parameters for the dummy charge were optimized based on the comparison between calculated radial distribution function and experimental one. Asymmetric coordination around Pb, for example trigonal bipyramid, was successfully reproduced in the MD simulated binary and ternary glass models. The simple model using the dummy charge was confirmed to be valid for further simulations of multicomponent glasses containing nuclear wastes and heavy elements.

  5. High-Pressure Synthesis and Characterization of the Actinide Borate Phosphate U2[BO4][PO4

    Science.gov (United States)

    Hinteregger, Ernst; Wurst, Klaus; Perfler, Lukas; Kraus, Florian; Huppertz, Hubert

    2013-01-01

    A new actinide borate phosphate, U2[BO4][PO4], was synthesized in a Walker-type multianvil apparatus at 12.5 GPa and 1000 °C. The crystal structure was determined from single-crystal X-ray diffraction data collected at room temperature. U2[BO4][PO4] crystallizes in the monoclinic space group P21/c with four formula units per unit cell and the lattice parameters a = 854.6(2), b = 775.3(2), c = 816.3(2) pm, and β = 102.52(3)°. The structure consists of double layers of linked uranium–oxygen polyhedra parallel to [100]. The borate tetrahedra are located between the uranium–oxygen layers inside the double layer. The phosphate groups link the double layers. PMID:24611029

  6. High-Pressure Synthesis and Characterization of the Actinide Borate Phosphate U2[BO4][PO4].

    Science.gov (United States)

    Hinteregger, Ernst; Wurst, Klaus; Perfler, Lukas; Kraus, Florian; Huppertz, Hubert

    2013-10-14

    A new actinide borate phosphate, U2[BO4][PO4], was synthesized in a Walker-type multianvil apparatus at 12.5 GPa and 1000 °C. The crystal structure was determined from single-crystal X-ray diffraction data collected at room temperature. U2[BO4][PO4] crystallizes in the monoclinic space group P21/c with four formula units per unit cell and the lattice parameters a = 854.6(2), b = 775.3(2), c = 816.3(2) pm, and β = 102.52(3)°. The structure consists of double layers of linked uranium-oxygen polyhedra parallel to [100]. The borate tetrahedra are located between the uranium-oxygen layers inside the double layer. The phosphate groups link the double layers.

  7. Agrobacterium-mediated transformation of kabocha squash (Cucurbita moschata Duch) induced by wounding with aluminum borate whiskers.

    Science.gov (United States)

    Nanasato, Yoshihiko; Konagaya, Ken-ichi; Okuzaki, Ayako; Tsuda, Mai; Tabei, Yutaka

    2011-08-01

    An efficient genetic transformation method for kabocha squash (Cucurbita moschata Duch cv. Heiankogiku) was established by wounding cotyledonary node explants with aluminum borate whiskers prior to inoculation with Agrobacterium. Adventitious shoots were induced from only the proximal regions of the cotyledonary nodes and were most efficiently induced on Murashige-Skoog agar medium with 1 mg/L benzyladenine. Vortexing with 1% (w/v) aluminum borate whiskers significantly increased Agrobacterium infection efficiency in the proximal region of the explants. Transgenic plants were screened at the T(0) generation by sGFP fluorescence, genomic PCR, and Southern blot analyses. These transgenic plants grew normally and T(1) seeds were obtained. We confirmed stable integration of the transgene and its inheritance in T(1) generation plants by sGFP fluorescence and genomic PCR analyses. The average transgenic efficiency for producing kabocha squashes with our method was about 2.7%, a value sufficient for practical use.

  8. Shielding behavior of V{sub 2}O{sub 5} doped lead borate glasses towards gamma irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Ghoneim, N.A.; ElBatal, H.A. [Glass Research Department, National Research Center, Dokki, Cairo (Egypt); Abdelghany, A.M., E-mail: a.m_abdelghany@yahoo.com [Spectroscopy Department, National Research Center, Dokki, Cairo (Egypt); Ali, I.S. [High Institute for Optics Technology, Dokki, Cairo (Egypt)

    2011-06-16

    Highlights: > Base lead borate glass together with samples of the same composition doped with varying V{sub 2}O{sub 5} contents were prepared. > UV-visible and infrared spectroscopy were measured before and after successive gamma irradiation. > Glass samples are observed to absorb strongly in the UV. > Infrared absorption spectra indicate the presence of both triangular and tetrahedral borate groups besides the sharing of lead ions in network forming and network modifying sites. - Abstract: Undoped lead borate glass of the composition PbO 70%-B{sub 2}O{sub 3} 30% together with samples of the same composition and doped with varying V{sub 2}O{sub 5} contents were prepared. UV-visible absorption spectra were measured out in the range 200-1500 nm before and after successive gamma irradiation. Infrared absorption measurements within the range 4000-400 cm{sup -1} were carried out for the undoped and V{sub 2}O{sub 5} doped samples before gamma irradiation and after being irradiated with a dose of 6 Mrad. All the glass samples are observed to absorb strongly in the UV region due to the combined contributions of absorption due to trace iron impurities and that from the divalent lead Pb{sup 2+} ions. The V{sub 2}O{sub 5}-doped glasses reveal extra visible absorption bands which are attributed to the existence of V{sup 3+} ions in measurable content but not neglecting the other valence states of vanadium ions (V{sup 4+}, V{sup 5+}). Infrared absorption spectra indicate the presence of both triangular and tetrahedral borate groups besides the sharing of lead ions in network forming and network modifying sites.

  9. Effects of varying base glass composition on the optical properties of lead borate glasses doped with rare earth ions

    Science.gov (United States)

    Heidorn, William D.

    Rare Earth (RE) doped lead borate glasses are expected to exhibit a compositional dependence in their optical properties due to the changes induced by variations in the structure of the base glass with increasing lead oxide content. A series of lead borate glasses with the composition xPbO:(99.5 - x)B2O 3 (x = 29.5 to 69.5 in steps of 10 mol%) doped with 0.5 mol% Sm2O3, Er2O3, and Ho2O3 were prepared using the melt quench technique followed by 3 hours of annealing near the glass transition temperature. Optical absorption and fluorescence spectra of these RE doped lead borate glasses were analyzed using Judd-Ofelt theory. The compositional dependence of Judd-Ofelt intensity parameters, O t (t = 2, 4, 6), were determined and were then used to calculate the radiative transition probability of the excited states, the total radiative transition probability, branching ratios, and radiative lifetime of the glasses. From the fluorescence spectra the stimulated emission cross section, and Stark splitting of the excited states were calculated as a function of glass composition. A fourth set of samples with composition xPbO:(99 - x)B2O 3(x = 29 to 69 in steps of 10 mol%) co-doped with 0.5 mol% Er2 O3 and Ho2O3 were also prepared and the effects of co-doping on the absorption and fluorescence were analyzed. In all the glass systems studied, it was found that the optical properties are strongly influenced by structural changes arising from compositional variation. Er3+ transitions exhibit large stimulated cross section suggesting the possible utilization of these materials in laser applications. Keywords: Lead and bismuth borate glasses, fluorescence, optical absorption, Sm3+, Ho3+, Er3+ ions, Judd-Ofelt intensity parameters, stimulated emission cross section.

  10. Wood zone plate fishnet metalens

    Directory of Open Access Journals (Sweden)

    Orazbayev Bakhtiyar

    2015-01-01

    Full Text Available Fresnel-zone plate lenses provide focusing performance while having low profile. Unfortunately, they usually display higher reflection losses than conventional dielectric lenses. Here, we demonstrate a low-profile Wood zone plate metalens based on the fishnet metamaterial working in a near-zero regime with an equivalent refractive index less than unity (nf = 0.51. The metalens is made of alternating dielectric and fishnet metamaterial concentric rings. The use of fishnet metamaterial allows reducing the reflections from the lens, while maintaining low profile, low cost and ease of manufacturing. The lens is designed to work at the W-band of the millimeter-waves range with a focal length FL = 22.8 mm (7.5 λ0 aiming at antenna or radar system applications. The focusing performance of the lens along with its radiation characteristics in a lens antenna configuration have been studied numerically and confirmed experimentally, showing a gain improvement of ~2.5 dB with respect to a fishnet Soret metalens.

  11. Short rotation Wood Crops Program

    Energy Technology Data Exchange (ETDEWEB)

    Wright, L.L.; Ehrenshaft, A.R.

    1990-08-01

    This report synthesizes the technical progress of research projects in the Short Rotation Woody Crops Program for the year ending September 30, 1989. The primary goal of this research program, sponsored by the US Department of Energy's Biofuels and Municipal Waste Technology Division, is the development of a viable technology for producing renewable feedstocks for conversion to biofuels. One of the more significant accomplishments was the documentation that short-rotation woody crops total delivered costs could be $40/Mg or less under optimistic but attainable conditions. By taking advantage of federal subsidies such as those offered under the Conservation Reserve Program, wood energy feedstock costs could be lower. Genetic improvement studies are broadening species performance within geographic regions and under less-than-optimum site conditions. Advances in physiological research are identifying key characteristics of species productivity and response to nutrient applications. Recent developments utilizing biotechnology have achieved success in cell and tissue culture, somaclonal variation, and gene-insertion studies. Productivity gains have been realized with advanced cultural studies of spacing, coppice, and mixed-species trials. 8 figs., 20 tabs.

  12. Gastro retention using polymer cocoons.

    Science.gov (United States)

    Arnold, Julien; Hunkeler, David

    2015-02-01

    A gastro-retentive capsule has been prepared which is retained in the stomach for a period of 24h, providing a vehicle for the controlled delivery to the upper intestines. These "gastro cocoons" can resist passage through the sphincter of the stomach, and can retain a high drug payload (30%). They are made from oppositely charged polyelectrolytes and can swell to twice their initial volume. They are strong and also can resist 550 N of compressive force. They are based on filled pharmaceutical capsules which are visible to X-rays. Using ambroxol hydrochloride as a model drug linear, zero-order, release curves were obtained.

  13. Luminescence investigations of rare earth doped lead-free borate glasses modified by MO (M = Ca, Sr, Ba)

    Energy Technology Data Exchange (ETDEWEB)

    Janek, Joanna, E-mail: janek.joanna@gmail.com; Sołtys, Marta; Żur, Lidia; Pietrasik, Ewa; Pisarska, Joanna; Pisarski, Wojciech A.

    2016-09-01

    Series of lead-free borate glasses with different oxide modifiers and lanthanide ions were prepared. The effect of oxide modifiers MO (M = Ca, Sr, Ba) on spectroscopic properties of trivalent Ln{sup 3+} (Ln = Eu, Er, Pr) were systematically investigated. Especially, the luminescence spectra of Ln{sup 3+}-doped lead-free borate glasses are presented and discussed in relation to the impact of selective components (CaO, SrO and BaO). Several spectroscopic parameters, such as the fluorescence intensity ratio R/O (Eu{sup 3+}) and measured luminescence lifetimes for the {sup 5}D{sub 0} (Eu{sup 3+}), {sup 4}I{sub 13/2} (Er{sup 3+}) and {sup 1}D{sub 2} (Pr{sup 3+}) excited states of lanthanide ions were analyzed in details. The research proved that spectroscopic properties of trivalent Ln{sup 3+} depend significantly on kind of presence oxide modifiers MO (M = Ca, Sr, Ba) in glass host matrices. - Highlights: • Luminescence of Ln{sup 3+}-doped borate glasses was presented and discussed. • Effect of glass modifiers on spectroscopic properties of rare earths was studied. • Measured luminescence lifetimes of Ln{sup 3+} (Ln = Eu, Er, Pr) were analyzed. • Luminescence intensity ratios R/O (Eu{sup 3+}) were determined.

  14. In vitro study of improved wound-healing effect of bioactive borate-based glass nano-/micro-fibers.

    Science.gov (United States)

    Yang, Qingbo; Chen, Sisi; Shi, Honglan; Xiao, Hai; Ma, Yinfa

    2015-10-01

    Because of the promising wound-healing capability, bioactive glasses have been considered as one of the next generation hard- and soft-tissue regeneration materials. The lack of understanding of the substantial mechanisms, however, indicates the need for further study on cell-glass interactions to better interpret the rehabilitation capability. In the present work, three bioactive glass nano-/micro-fibers, silicate-based 45S5, borate-based 13-93B3 and 1605 (additionally doped with copper oxide and zinc oxide), were firstly compared for their in vitro soaking/conversion rate. The results of elemental monitoring and electron microscopic characterization demonstrated that quicker ion releasing and glass conversion occurred in borate-based fibers than that of silicate-based one. This result was also reflected by the formation speed of hydroxyapatite (HA). This process was further correlated with original boron content and surrounding rheological condition. We showed that an optimal fiber pre-soaking time (or an ideal dynamic flow rate) should exist to stimulate the best cell proliferation and migration ability. Moreover, 13-93B3 and 1605 fibers showed different glass conversion and biocompatibility properties as well, indicating that trace amount variation in composition can also influence fiber's bioactivity. In sum, our in vitro rheological module closely simulated in vivo niche environment and proved a potentially improved wound-healing effect by borate-based glass fibers, and the results shall cast light on future improvement in bioactive glass fabrication.

  15. Structure and lattice dynamics in non-centrosymmetric borates; Struktur und Gitterdynamik in azentrischen Boraten

    Energy Technology Data Exchange (ETDEWEB)

    Stein, W.D.R.

    2007-04-23

    This thesis deals with a study of structural and lattice dynamical properties of some noncentrosymmetric borates with outstanding non-linear optical properties. The focus was on the compound bismuth triborate (BiB{sub 3}O{sub 6}). The structure of the tetraborates MB{sub 4}O{sub 7} (M=Pb,Sr,Ba) was also investigated. The structural investigations in bismuth triborate include powder and single crystal diffraction experiments on X-ray and neutron sources. The crystal structure was under examination in the temperature range from 100 K to room temperature and the lattice constants in the temperature range from 20 K to 800 K. The lattice constants show a nearly linear dependency from temperature. Our observations are in good agreement with investigations of the thermal expansion, which shows a strong anisotropy within the layer-like structure of bismuth triborate. Within the borate layers, along the polar axis a strong positive and in the orthogonal direction a negative thermal expansion is observed. This effect can be explained by a zig-zag effect within the borate layers. The lone electron pair at the bismuth atom is discussed to be possibly the origin of the temperature dependency of the coordination environment of the bismuth atom. The influence of the lone electron pair on the crystal structure is raising by lowering the temperature. At the bismuth atom distinct anharmonic effects are observed, where the maximum points along the direction of the polar axis and therefore along the direction of the lone electron pair. The phonon dispersion of bismuth triborate has been investigated by inelastic neutron scattering. The low symmetry of the crystal structure depicts to be a special challenge. The dispersion was observed along the three reciprocal lattice constants. Along the polar axis the dispersion could be characterized to a maximum energy of 20 THz. The low energy acoustic branch along the polar axis shows a softening at the zone boundary. In the orthogonal

  16. Overview of ultraviolet and infrared spectroscopic properties of Yb{sup 3+} doped borate and oxy-borates compounds; De l'ultraviolet a l'infrarouge: caracterisation spectroscopique de materiaux type borate et oxyborate dopes a l'ytterbium trivalent

    Energy Technology Data Exchange (ETDEWEB)

    Sablayrolles, J

    2006-12-15

    The trivalent ytterbium ion can give rise to two emissions with different spectroscopic properties: the first one, with a short lifetime, in the ultraviolet (charge transfer emission) is used in detectors such as scintillators, and the other one, with a long lifetime, in the infrared (4f-4f emission) for laser applications. The strong link between material structure and properties is illustrated through ytterbium luminescence study, in the ultraviolet and infrared, inserted in the borate Li{sub 6}Y(BO{sub 3}){sub 3} and two oxy-borates: LiY{sub 6}O{sub 5}(BO{sub 3}){sub 3} and Y{sub 17,33}B{sub 8}O{sub 38}. For the first time an ytterbium charge transfer emission in oxy-borates has been observed. The calculation of the single configurational coordinate diagram, as well as the thermal quenching, has been conducted under a fundamental approach on the ytterbium - oxygen bond. The study of the ytterbium infrared spectroscopy in these compounds has been realised and an energy level attribution is proposed in the particular case of the borate Li{sub 6}Y(BO{sub 3}){sub 3}: Yb{sup 3+}. An original approach is introduced with the study of the charge transfer states for the three compounds by looking at the infrared emission. The first laser performances in three operating modes (continuous wave, Q-switch and mode locking) of a Li{sub 6}Y(BO{sub 3}){sub 3}: Yb{sup 3+} crystal are reported. (author)

  17. Exposure to wood dust and endotoxin in small-scale wood industries in Tanzania.

    NARCIS (Netherlands)

    Rongo, L.M.B.; Msamanga, G.I.; Burstyn, I.; Barten, F.J.M.H.; Dolmans, W.M.V.; Heederik, D.

    2004-01-01

    Workers in small-scale wood industries (SSWI) have increased risks of developing asthma and other respiratory diseases. Wood dust and microbial agents have both been suggested to play a role, but few studies have measured endotoxin exposure in SSWI in Africa. We assessed inhalable dust levels in 281

  18. Fracture tolerance of reaction wood (yew and spruce wood in the TR crack propagation system).

    Science.gov (United States)

    Stanzl-Tschegg, Stefanie E; Keunecke, Daniel; Tschegg, Elmar K

    2011-07-01

    The fracture properties of spruce and yew were studied by in-situ loading in an environmental scanning microscope (ESEM). Loading was performed with a micro-wedge splitting device in the TR-crack propagation direction. The emphasis was laid on investigating the main mechanisms responsible for a fracture tolerant behavior with a focus on the reaction wood. The fracture mechanical results were correlated with the features of the surface structure observed by the ESEM technique, which allows loading and observation in a humid environment. Some important differences between the reaction wood and normal wood were found for both investigated wood species (spruce and yew), including the formation of cracks before loading (ascribed to residual stresses) and the change of fracture mode during crack propagation in the reaction wood. The higher crack propagation resistance was attributed mainly to the different cell (i.e. fiber) geometries (shape, cell wall thickness) and fiber angle to the load axis of the reaction wood, as basic structural features are responsible for more pronounced crack deflection and branching, thus leading to crack growth retardation. Fiber bridging was recognized as another crack growth retarding mechanism, which is effective in both wood species and especially pronounced in yew wood.

  19. Climate effects of wood used for bioenergy

    Energy Technology Data Exchange (ETDEWEB)

    Ros, Jan P.M.; Van Minnen, Jelle G. [Netherlands Environmental Assessment Agency PBL, Bilthoven (Netherlands); Arets, Eric J.M.M. [Alterra, Wageningen University WUR, Wageningen (Netherlands)

    2013-08-15

    Wood growth and natural decay both take time, and this is an important aspect of sustainability assessments of wood used for energy. Wood taken from forests is a carbon-neutral energy source in the long term, but there are many examples of potential sources of wood used for bioenergy for which net emission reductions are not achieved in 10 to 40 years - the time frame for most climate policy mitigation targets. This is caused by two factors. The first factor relates to the fact that the carbon cycles of wood have a long time span. After final felling, CO2 fixation rates are initially relatively low, but increase again as forests regrow. This regrowth takes many years, sometimes more than a century. Wood residues can either be used or left in the forest. By using them, the emissions from the otherwise decaying residues (taking 2 to 30 years) would be avoided. The second factor concerns the fact that, if the wood is used for bioenergy, then fossil energy emissions are being avoided. However, the direct emission levels from bioenergy are higher than those related to the fossil energy it replaces. These additional emissions also have to be compensated. The carbon debt caused by both factors has to be paid back first, before actual emission reductions can be realised. For wood residues (from harvesting or thinning) that are used to replace coal or oil products, these payback times are relatively short, of the order of 5 to 25 years, mainly depending on location and type of residue (longer if they replace gas). This is also the case when using wood from salvage logging. In most cases, when using wood from final felling directly for energy production, payback times could be many decades to more than a century, with substantial increases in net CO2 emissions, in the meantime. This is especially the case for many forests in Europe, because they are currently an effective carbon sink. Additional felling reduces average growth rates in these forests and thus the sequestration

  20. ROUGHNESS ON WOOD SURFACES AND ROUGHNESS MEASUREMENT METHODS

    Directory of Open Access Journals (Sweden)

    İsmail Aydın

    2003-04-01

    Full Text Available Some visual characteristics of wood such as color, pattern and texture determine the quality of manufactured products. Surface properties of wood material are important both in production and marketing after production. Initial studies related to the roughness of wood surface were begun in early 1950’s. However, no general agreed standardization can not have been developed for wood surfaces. Surface roughness of wood is function of the production process, product type and the natural anatomical properties of wood. Contact and non-contact tracing methods are used to measure of wood surface roughness. Surface roughness also affects the gluability and wettability of wood surfaces. The success in finishing also depends on the surface roughness of wood.

  1. Radionuclide Retention in Concrete Wasteforms

    Energy Technology Data Exchange (ETDEWEB)

    Wellman, Dawn M.; Jansik, Danielle P.; Golovich, Elizabeth C.; Cordova, Elsa A.

    2012-09-24

    Assessing long-term performance of Category 3 waste cement grouts for radionuclide encasement requires knowledge of the radionuclide-cement interactions and mechanisms of retention (i.e., sorption or precipitation); the mechanism of contaminant release; the significance of contaminant release pathways; how wasteform performance is affected by the full range of environmental conditions within the disposal facility; the process of wasteform aging under conditions that are representative of processes occurring in response to changing environmental conditions within the disposal facility; the effect of wasteform aging on chemical, physical, and radiological properties; and the associated impact on contaminant release. This knowledge will enable accurate prediction of radionuclide fate when the wasteforms come in contact with groundwater. Data collected throughout the course of this work will be used to quantify the efficacy of concrete wasteforms, similar to those used in the disposal of LLW and MLLW, for the immobilization of key radionuclides (i.e., uranium, technetium, and iodine). Data collected will also be used to quantify the physical and chemical properties of the concrete affecting radionuclide retention.

  2. Furniture wood wastes: experimental property characterisation and burning tests.

    Science.gov (United States)

    Tatàno, Fabio; Barbadoro, Luca; Mangani, Giovanna; Pretelli, Silvia; Tombari, Lucia; Mangani, Filippo

    2009-10-01

    Referring to the industrial wood waste category (as dominant in the provincial district of Pesaro-Urbino, Marche Region, Italy), this paper deals with the experimental characterisation and the carrying out of non-controlled burning tests (at lab- and pilot-scale) for selected "raw" and primarily "engineered" ("composite") wood wastes. The property characterisation has primarily revealed the following aspects: potential influence on moisture content of local weather conditions at outdoor wood waste storage sites; generally, higher ash contents in "engineered" wood wastes as compared with "raw" wood wastes; and relatively high energy content values of "engineered" wood wastes (ranging on the whole from 3675 to 5105 kcal kg(-1) for HHV, and from 3304 to 4634 kcal kg(-1) for LHV). The smoke qualitative analysis of non-controlled lab-scale burning tests has primarily revealed: the presence of specific organic compounds indicative of incomplete wood combustion; the presence exclusively in "engineered" wood burning tests of pyrroles and amines, as well as the additional presence (as compared with "raw" wood burning) of further phenolic and containing nitrogen compounds; and the potential environmental impact of incomplete industrial wood burning on the photochemical smog phenomenon. Finally, non-controlled pilot-scale burning tests have primarily given the following findings: emission presence of carbon monoxide indicative of incomplete wood combustion; higher nitrogen oxide emission values detected in "engineered" wood burning tests as compared with "raw" wood burning test; and considerable generation of the respirable PM(1) fraction during incomplete industrial wood burning.

  3. Fission-product retention in HTGR fuels

    Energy Technology Data Exchange (ETDEWEB)

    Homan, F.J.; Kania, M.J.; Tiegs, T.N.

    1982-01-01

    Retention data for gaseous and metallic fission products are presented for both Triso-coated and Biso-coated HTGR fuel particles. Performance trends are established that relate fission product retention to operating parameters, such as temperature, burnup, and neutron exposure. It is concluded that Biso-coated particles are not adequately retentive of fission gas or metallic cesium, and Triso-coated particles which retain cesium still lose silver. Design implications related to these performance trends are identified and discussed.

  4. A Study on Employee Retention Techniques

    OpenAIRE

    Savarimuthu, Dr. A; Hemalatha, N

    2013-01-01

    The objective of perusing this study is to assess the level of satisfaction of employee retention techniques at GB Engineering Enterprises PVT Limited., Trichy.This study gains significance because of employee retention techniques can be approached from various angles. It is desirable state of existence involving retention strategies generally fall in to one of four categories salary, working conditions, job enrichment and education. These four elements together constitute. The structure of e...

  5. DURABILTY OF 25 LOCAL SPECIFIC WOOD SPECIES FROM JAVA PRESERVED WITH CCB AGAINST MARINE BORERS ATTACK

    Directory of Open Access Journals (Sweden)

    Mohammad Muslich

    2010-12-01

    Full Text Available This study was conducted to provide basis information of the 25 local specific wood species indigenous from Java treated by copper bichromated boron (CCB. The full-cell process for 2 hours and 150 psi during the pressure-keeping period was employed. The IUFRO method was applied for the determination of wood treatability class. The treated and untreated wood specimens were tied together using plastic cord, arranged into a raft like assembly, and then exposed for 3, 6, and 12 months to the brackish water situated at Rambut Island’s coastal area. The Nordic Wood Preservation Council (NWPC standard No.1.4.2.2/75 was used to determine the intensity of marine borer infestation. The results revealed that 19 out of those 25 species were classified as easy to be preser ved, four species as moderate, and the remaining two were difficult to be preser ved. Those 19 species, i.e. Tamarindus indica L., Diplodiscus sp., Ficus variegate R .Br., Ehretia acuminata R .Br., Meliocope lunu-ankenda (Gaertn T.G. Hartley, Colona javanica B.L., Pouteria duclitanBachni., Stercularia oblongata R .Br., Ficus vasculosa Wall ex Miq., Callophyllum grandiflorum JJS., Turpinia sphaerocarpa Hassk., Neolitsea triplinervia Merr., Acer niveum Bl., Sloanea sigun Szysz., Castanopsis acuminatissima A.DC., Cinnamomum iners Reinw. Ex Blume., Litsea angulata Bl., Ficus nervosa Heyne., and Horsfieldia glabra Warb. were more permeable implying that the CCB retention and penetration were greater and deeper. Hymeneaecarboril.L., LitseaodoriferaVal., Gironniera subasqualisPlanch., and LinderapolyanthaBoerl. were moderately permeable. Castanopsis tunggurut A.DC. and Azadirachta indica Juss. were the least permeable judging that the CCB retention and penetration were lowest and shallowest. The treated wood specimens in this regard were able to prevent marine borers attack. Meanwhile, the untreated specimens were susceptible to marine borers attack, except Azadirachta indica. The attacking

  6. An Investigation of Consolidants Penetration in Wood. Part 1: General Methodology and Microscopy

    Directory of Open Access Journals (Sweden)

    Maria Cristina TIMAR

    2010-12-01

    Full Text Available Consolidation of degraded and frail wood by impregnation with synthetic and natural polymeric compounds in solution is one of the most important operations of active conservation of wooden cultural heritage. The effectiveness of such a treatment depends essentially on the consolidant retention, penetration and uniformity of distribution, aspects that could be cumulated in the term of impregnation level and practically influenced by many and various factors. The purpose of this work was to look at some practical possibilities of characterising the impregnation level achieved in some consolidation treatments with different solutions of a frequently employed synthetic polymer (Paraloid B72 and waxes (beeswax and modified paraffins as melts or in combination with linseed oil using a simple optical microscopy technique in conjunction with an original method of samples preparation. For this purpose were used small samples of sound, not degraded spruce (Picea abies Mill, which were impregnated by short time immersion. The examination in transmitted light (TLM of the cross-cut micro sections and in reflected light (RLM of the wooden blocks allowed the visualisation of the consolidation products and their distribution in the wood structure, but this was easier for the consolidants with high solids content (waxes, which partly filled the lumens, and much more difficult and relative in the case of the diluted Paraloid solutions which did not fill the lumens but only impart a very shiny, highly reflective aspect of the treated areas. In order to objectively appreciate the retention and penetration of consolidants into wood the method using ImageJ, a useful image processing software, was used to process the micrographs so that some quantitative estimations of the variation of the impregnation level with the penetration depth were obtained.

  7. Temperature effects on wood anatomy, wood density, photosynthesis and biomass partitioning of Eucalyptus grandis seedlings.

    Science.gov (United States)

    Thomas, D S; Montagu, K D; Conroy, J P

    2007-02-01

    Wood density, a gross measure of wood mass relative to wood volume, is important in our understanding of stem volume growth, carbon sequestration and leaf water supply. Disproportionate changes in the ratio of wood mass to volume may occur at the level of the whole stem or the individual cell. In general, there is a positive relationship between temperature and wood density of eucalypts, although this relationship has broken down in recent years with wood density decreasing as global temperatures have risen. To determine the anatomical causes of the effects of temperature on wood density, Eucalyptus grandis W. Hill ex Maiden seedlings were grown in controlled-environment cabinets at constant temperatures from 10 to 35 degrees C. The 20% increase in wood density of E. grandis seedlings grown at the higher temperatures was variously related to a 40% reduction in lumen area of xylem vessels, a 10% reduction in the lumen area of fiber cells and a 10% increase in fiber cell wall thickness. The changes in cell wall characteristics could be considered analogous to changes in carbon supply. Lumen area of fiber cells declined because of reduced fiber cell expansion and increased fiber cell wall thickening. Fiber cell wall thickness was positively related to canopy CO2 assimilation rate (Ac), which increased 26-fold because of a 24-fold increase in leaf area and a doubling in leaf CO2 assimilation rate from minima at 10 and 35 degrees C to maxima at 25 and 30 degrees C. Increased Ac increased seedling volume, biomass and wood density; but increased wood density was also related to a shift in partitioning of seedling biomass from roots to stems as temperature increased.

  8. Ultrasonic sensor to characterize wood pulp during refining.

    Science.gov (United States)

    Greenwood, M S; Panetta, P D; Bond, L J; McCaw, M W

    2006-12-22

    A novel sensor concept has been developed for measuring the degree of refining, the water retention value (WRV), and the weight percentage of wood pulp during the refining process. The measurement time is less than 5 min and the sensor can operate in a slip-stream of the process line or as an at-line instrument. The degree of refining and the WRV are determined from settling measurements. The settling of a pulp suspension (with a weight percentage less than 0.5 wt%) is observed, after the mixer, which keeps the pulp uniformly distributed, is turned off. The attenuation of ultrasound as a function of time is recorded and these data show a peak at a time designated as the "peak time." The peak time T increases with the degree of refining, as demonstrated by measuring pulp samples with known degrees of refining. The WRV can be determined using the relative peak time, defined as the ratio T(2)/T(1), where T(1) is an initial peak time and T(2) is the value after additional refining. This method offers an alternative WRV test for the industry to the current time-consuming method.

  9. [Application of near infrared spectroscopy in analysis of wood properties].

    Science.gov (United States)

    Yao, Sheng; Pu, Jun-wen

    2009-04-01

    There is substantial interest in the improvement of wood properties through genetic selection or a change in silviculture prescription. Tree breeding purpose requires measurement of a large number of samples. However, traditional methods of assessing wood properties are both time consuming and destructive, limiting the numbers of samples that can be processed, so new method would be needed to find. Near infrared spectroscopy (NIR) is an advanced spectroscopic tool for nondestructive evaluation of wood and it can quickly, accurately estimate the properties of increment core, solid wood or wood meal. The present paper reviews the advances in the research on the wood chemistry properties and anatomical properties using NIR.

  10. General Regularities of Wood Surface Roughness

    Directory of Open Access Journals (Sweden)

    MAGOSS, Endre

    2008-01-01

    Full Text Available The surface roughness of wood products is depending on many factors related both towood properties and wood working operational parameters. Probably this is the reason why there areno generally valid correlation determining surface roughness parameters as a function of influencingfactors. In particular, the account of wood structure in the surface roughness interpretation proved tobe difficult.In the last years an important progress was made in recognizing the role of the anatomicalstructure of wood species in the attainable surface roughness. The introduction of a structure numbermade it possible to express and characterize the different wood species numerically.The aim of these studies was the separation of roughness components due to the anatomicalstructure and the woodworking operation. Using a special finishing technique, the roughnesscomponent due to woodworking operations was not significant and could be separated. The samespecimens were also subjected to different woodworking operations using cutting velocities between10 and 50 m/s. The processing of experimental data resulted in a chart showing the minimumroughness component due to different woodworking operations. Special experimental investigationwas conducted to clear the influence of edge dullness on the surface roughness, especially on itsAbbott-parameters. The measurements showed that the Rk-parameter is a good indicator to predictedge dullness.

  11. Fabrication and characterization of poly (bisphenol A borate) with high thermal stability

    Science.gov (United States)

    Wang, Shujuan; Wang, Xiao; Jia, Beibei; Jing, Xinli

    2017-01-01

    In this work, poly (bisphenol A borate) (PBAB), which has excellent thermal resistance and a high char yield, was synthesized via a convenient A2 + B3 strategy by using bisphenol A (BPA) and boric acid (BA). The chemical reaction between BPA and BA and the chemical structure of PBAB were investigated. The results demonstrate that PBAB consists of aromatic, Ph-O-B and B-O-B structures, as well as a small number of boron hydroxyl groups and phenolic hydroxyl groups. The thermal properties of PBAB were studied by DMA and TGA. The results indicate that the glass transition temperature and char yield are gradually enhanced by increasing the boron content, where the char yield of PBAB at 800 °C in nitrogen (N2) reaches up to 71.3%. It is of particular importance that PBAB show excellent thermal resistance in N2 and air atmospheres. By analysing the pyrolysis of PBAB, the high char yield of PBAB can be attributed to the formation of boron oxide and boron carbide at high temperatures, which reduced the release of volatile carbon dioxide and improved the thermal stability of the carbonization products. This study provides a new perspective on the design of novel boron-containing polymers and possesses significant potential for the improvement of the comprehensive performance of thermosetting resins to broaden their applicability in the field of advanced composites.

  12. Influence of europium (Eu3+) ions on the optical properties of silver lead borate glasses

    Indian Academy of Sciences (India)

    K Keshavamurthy; B Eraiah

    2015-09-01

    The influence of europium (Eu3+) ions on the optical properties of silver lead borate glasses of the Eu2O3–(1 – )Ag2O–29PbO–70B2O3 ( = 0, 0.1, 0.2, 0.3, 0.4 and 0.5 mol%) glass system prepared by the conventional melt quenching technique and their physical and optical properties were investigated. The UV absorption spectra were recorded at room temperature in the wavelength range of 200–600 nm. From the absorption edge data, it is found that both the direct and indirect transitions and their values are ranging from 3.19 to 3.54 and 2.50 to 3.07 eV, respectively. The Urbach energy values for these glasses were found to be in the range of 0.39–0.52 eV. The refractive indices have also been evaluated with respect to different molar concentrations of Eu2O3 and their calculated values are ranging from 1.598 to 1.654.

  13. Optical and shielding behavior studies of vanadium-doped lead borate glasses

    Science.gov (United States)

    Abdelghany, A. M.; ElBatal, H. A.; Marei, L. K.

    2012-01-01

    A glass sample of composition PbO 42.1%- B2O3 57.9 mol% B2O3 together with samples of the same composition doped with varying V2O5 contents was prepared via melt annealing technique. X-ray diffraction technique was applied to prove the amorphous nature of the prepared glasses. UV-visible absorption spectra were measured in the range 200-1500 nm before and after successive gamma irradiation, which were applied to evaluate optical properties, including direct and indirect optical energy band gaps before and after gamma irradiation. Undoped glass sample is observed to exhibit strong UV absorption; due to the combined contributions of absorption of both Pb2+ ions and trace iron impurities. The presence of V3+ ions together with the other vanadium valence states (V4+, V5+) was proved by the appearance of extra visible absorption bands. Infrared absorption spectra were measured in the range 4000-400 cm-1 which revealed the presence of both triangular and tetrahedral borate groups besides the sharing of lead ions.

  14. Optical characterization of Cu2+ ion-doped zinc lead borate glasses

    Science.gov (United States)

    Thulasiramudu, A.; Buddhudu, S.

    2006-01-01

    We have developed a new series of zinc lead borate (ZLB) glasses by varying ZnO content, to enhance UV transmission, in the chemical composition of xZnO 15PbO (85-x)B2O3, where x=0, 5, 10, 15, 20, 25, 30, 35, 40 and 45 mol% ZnO. From the measurement of UV absorption spectra both the direct and indirect band gaps have been evaluated. Also different physical properties of a reference glass of 45ZnO 15PbO 40B2O3 have been studied. From the measurement of refractive indices at six different wavelengths, Cauchy's constants (A=1.578743209; B=131832.33nm and C=-0.77756×10nm) have been computed and a satisfactory correlation has been achieved between the theoretical and the experimental results. Absorption spectra of Cu2+(45-x)ZnO 15PbO 40B2O3 (where x=0.1, 0.2, 0.5 and 1.0 mol%) have shown two absorption bands at 428 nm (2B1g→2Eg) and 777 nm (2B1g→2B2g). Emission spectra of (1.0 mol%) Cu2+:ZLB have revealed two emission transitions at 400 and 493 nm with excitations at 288 and 316 nm.

  15. Luminescence properties of Tm3+/Yb3+ codoped lead alumina bismuth borate glasses

    Science.gov (United States)

    Goud, K. Krishna Murthy; Reddy, M. Chandra Shekhar; Rao, B. Appa

    2016-05-01

    This paper reports on the spectroscopic properties of Yb3+ and Tm3+ codoped lead alumina bismuth borate glasses. Optical absorption spectra of these Samples were recorded at room temperature in the wavelength range 350-2000 nm. The absorption spectra exhibited the bands at 658 nm (3H6→3F2), 686 nm (3H6→3F3), 792 nm (3H6→3H4), 1211 nm (3H6→3H5) and 1663 nm (3H6→3F4) due to Tm3+ ions. The band at 977 nm (2F7/2→2F5/2) is due to Yb3+ ions. Optical band gap (Eopt) and Urbach energy (ΔE) values were calculated from the spectra. It was observed that the value of optical band gap decreases with increase in the concentration of Tm3+ ions. The upconversion luminescence spectra were measured under excitation of 980 nm laser diode, and the intense blue (470 nm) and green (656 nm) emission were simultaneously observed at room temperature. A proposed upconversion mechanism involving energy transfer from Yb3+ to Tm3+ has been presented.

  16. Role of iron addition on structure and electrical and magnetic properties of lithium lead borate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Farouk, H. [Al-Azhar Univ, Cairo (Egypt). Dept. of Phys.; Solimani, A.A. [Ain Shams Univ., Cairo (Egypt). Dept. of Physics; Aly, S.A. [Al-Azhar Univ, Cairo (Egypt). Dept. of Phys.; El-Deen, H.Z. [Al-Azhar Univ, Cairo (Egypt). Dept. of Phys.; Kashif, I. [Al-Azhar Univ, Cairo (Egypt). Dept. of Phys.; Sanad, A.M. [Al-Azhar Univ, Cairo (Egypt). Dept. of Phys.

    1996-04-01

    The effect of iron oxide addition on the structure and electrical and magnetic properties of lithium lead borate glasses was studied using IR transmission spectra, optical absorption techniques, electrical conductivity, magnetic susceptibility measurements and differential thermal analysis (DTA). IR transmission spectra showed that the addition of up to 3 mol.% iron oxide to the samples introduced as modifiers at the expense of Pb ions. When the amount of iron oxide is increased to more than 3 mol.%, the iron enters the glass structure as network former with an FeO{sub 4} structure. The optical absorption properties of glass samples containing different amounts of iron oxide indicated that the oxidation state and the coordination of the doping ions are octahedral. At high contents of iron oxide, some of the iron ions exist in a tetrahedral form. The electrical conductivities as a function of temperature for glass samples containing different amounts of iron oxide up to 10 mol.% Fe{sub 2}O{sub 3} have similar behaviours, from which we deduced the activation energy for each sample. The investigation of the magnetic susceptibility as a function of Fe{sub 2}O{sub 3} concentration concluded that, for high amounts of iron ions, the iron ions exist in an octahedral coordination rather then in a tetrahedral coordination. DTA showed that the samples containing up to 5 mol.% iron oxide are characterized by one crystallization temperature, while samples containing 10 mol.% iron oxide have two crystallization temperatures. (orig.)

  17. Optical characterization of Eu 3+ and Tb 3+ ions doped zinc lead borate glasses

    Science.gov (United States)

    Thulasiramudu, A.; Buddhudu, S.

    2007-02-01

    This paper reports on the spectral analysis of Eu 3+ or Tb 3+ ions (0.5 mol%) doped heavy metal oxide (HMO) based zinc lead borate glasses from the measurement of their absorption, emission spectra and also different physical properties. From the XRD, DSC profiles, the glass nature and glass thermal properties have been studied. The measured emission spectrum of Eu 3+ glass has revealed five transitions ( 5D 0 → 7F 0, 7F 1, 7F 2, 7F 3 and 7F 4) at 578, 591, 613, 654 and 702 nm, respectively, with λexci = 392 nm ( 7F 0 → 5L 6). In the case of Tb 3+:ZLB glass, four emission transitions such as ( 5D 4→ 7F 6, 7F 5, 7F 4 and 7F 3) that are located at 489, 542, 585 and 622 nm, respectively, have been measured with λexci = 374 nm. For all these emission bands decay curves have been plotted to evaluate their lifetimes and the emission processes that arise in the glasses have been explained in terms of energy level schemes.

  18. Optical absorption and fluorescence properties of Er3+/Yb3+ codoped lead bismuth alumina borate glasses

    Science.gov (United States)

    Goud, K. Krishna Murthy; Reddy, M. Chandra Shekhar; Rao, B. Appa

    2014-04-01

    Lead bismuth alumina borate glasses codoped with Er3+/Yb3+ were prepared by melt quenching technique. Optical absorption, FTIR and photoluminescence spectra of these glasses have been studied. Judd-Ofelt theory has been applied to to the f ↔ f transitions for evaluating Ω2, Ω4 and Ω6 parameters. Radiative properties like branching ratio βr and the radiative life time τR have been determined on the basis of Judd-Ofelt theory. Upconversion emissions have been observed under 980nm laser excitation at room temperature. Green and red up-conversion emissions are centered at 530, 550 and 656 nm corresponding to 2H11/2→4I15/2, 4S3/2→4I15/2 and 4F9/2→4I15/2 transitions of Er3+ respectively. The results obtained are discussed quantitatively based on the energy transfer between Yb3+ and Er3+.

  19. Ethylene glycol assisted low-temperature synthesis of boron carbide powder from borate citrate precursors

    Directory of Open Access Journals (Sweden)

    Rafi-ud-din

    2014-09-01

    Full Text Available B4C powders were synthesized by carbothermal reduction of ethylene glycol (EG added borate citrate precursors, and effects of EG additions (0–50 mol% based on citric acid on the morphologies and yields of synthesized B4C powders were investigated. The conditions most suitable for the preparation of precursor were optimized and optimum temperature for precursor formation was 650 °C. EG additions facilitated low-temperature synthesis of B4C at 1350 °C, which was around 100–300 °C lower temperature compared to that without EG additions. The lowering of synthesis temperature was ascribed to the enlargement of interfacial area caused by superior homogeneity and dispersibility of precursors enabling the diffusion of reacting species facile. The 20% EG addition was optimal with free residual carbon lowered to 4%. For smaller EG additions, the polyhedral and rod-like particles of synthesized product co-existed. With higher EG additions, the morphology of synthesized product was transformed into needle and blade-like structure.

  20. Thermoluminescence properties of lithium magnesium borate glasses system doped with dysprosium oxide.

    Science.gov (United States)

    Mhareb, M H A; Hashim, S; Ghoshal, S K; Alajerami, Y S M; Saleh, M A; Razak, N A B; Azizan, S A B

    2015-12-01

    We report the impact of dysprosium (Dy(3+)) dopant and magnesium oxide (MgO) modifier on the thermoluminescent properties of lithium borate (LB) glass via two procedures. The thermoluminescence (TL) glow curves reveal a single prominent peak at 190 °C for 0.5 mol% of Dy(3+). An increase in MgO contents by 10 mol% enhances the TL intensity by a factor of 1.5 times without causing any shift in the maximum temperature. This enhancement is attributed to the occurrence of extra electron traps created via magnesium and the energy transfer to trivalent Dy(3+) ions. Good linearity in the range of 0.01-4 Gy with a linear correlation coefficient of 0.998, fading as low as 21% over a period of 3 months, excellent reproducibility without oven annealing and tissue equivalent effective atomic numbers ~8.71 are achieved. The trap parameters, including geometric factor (μg), activation energy (E) and frequency factor (s) associated with LMB:Dy are also determined. These favorable TL characteristics of prepared glasses may contribute towards the development of Li2O-MgO-B2O3 radiation dosimeters.

  1. Ho3+-doped strontium-aluminium-bismuth-borate glasses for green light emission.

    Science.gov (United States)

    Rajesh, D; Dhamodhara Naidu, M; Ratnakaram, Y C; Balakrishna, A

    2014-11-01

    Strontium-aluminium-bismuth-borate glasses (SAlBiB) doped with different concentrations of Ho(3+) were prepared using conventional melt quenching technique and their structural and optical properties investigated. X-ray diffraction and scanning electron microscopy analysis were used to study the structural properties. Optical properties were studied by measuring the optical absorption and visible luminescence spectra. The Judd-Ofelt (J-O) theory was applied to evaluate J-O intensity parameters, Ω(λ) (λ = 2, 4 and 6). Using J-O intensity parameters, radiative properties such as spontaneous transition probabilities (A(R)), branching ratios (β(R)) and radiative lifetimes (τ(R)) were determined. From the emission spectra, a strong green emission nearly at 549 nm corresponding to the transition, (5)S2 ((5)F4)→(5)I(8) was observed. Emission peak positions (λ(P)), effective bandwidths (Δλ(eff)) and stimulated emission cross-sections (σ(p)) were calculated for the observed emission transitions, (5)F3 →(5)I(8), (5)S2((5)F4)→(5)I(8) and (5)F5 →(5)I(8) of Ho(3+) in all the glass matrices. Chromaticity color coordinates were calculated using the emission spectra. The experimental results suggest that SAlBiB glass matrix with 1.5 mol% of Ho(3+) has better emission properties.

  2. Dy3+ doped Lithium Sodium Bismuth Borate Glasses for Yellow Luminescent Photonic Applications

    Directory of Open Access Journals (Sweden)

    M. Parandamaiah,

    2015-08-01

    Full Text Available Lithium sodium bismuth borate glasses-doped with trivalent dysprosium (Dy3+ ions (LSBiB have been prepared by conventional melt-quenching technique and characterized by structural, thermal and spectroscopic measurements. XRD pattern of the host glass confirms its amorphous nature. Morphological and elemental analysis has also been carried out for Dy3+doped LSBiB glass matrix. FTIR spectral analysis confirms the glass formation of the host glass. Optical absorption spectral analysis has been carried out for 0.8 mol% Dy3+ doped LSBiB glass sample. Well defined optical absorption bands are assigned with corresponding electronic transitions. Photoluminescence spectra shows two prominent emission bands centered at 482 nm and 575 nm corresponds to the 4 F9/2 → 6H15/2 and 4 F9/2 → 6H13/2 respectively under the excitation of 452 nm. Among all the concentrations of Dy3+ ions, at 0.8 mol% Dy3+ contained glass sample exhibits prominent yellow emission at 575 nm. Lifetime decay dynamics have been systematically analyzed for all the glasses, higher lifetime is found to be 0.47 ms for 0.8 mol% Dy3+ ions doped glass. From the photoluminescence analysis, Dy3+ contained glass samples could be suggested as potential yellow luminescent glass matrix for several photonic device applications.

  3. Tribological characteristics of monodispersed cerium borate nanospheres in biodegradable rapeseed oil lubricant

    Science.gov (United States)

    Boshui, Chen; Kecheng, Gu; Jianhua, Fang; Jiang, Wu; Jiu, Wang; Nan, Zhang

    2015-10-01

    Stearic acid-capped cerium borate composite nanoparticles, abbreviated as SA/CeBO3, were prepared by hydrothermal method. The morphologies, element compositions, size distributions, crystal and chemical structures, hydrophobic characteristics, of SA/CeBO3 were characterized by scanning electron microscope, energy dispersive X-ray spectrometer, dynamic laser particle size analyzer, X-ray diffraction, and Fourier transform infrared spectrometer, respectively. The friction and wear performances of SA/CeBO3 as a lubricating additive in a rapeseed oil were evaluated on a four-ball tribo-tester. The tribochemical characteristics of the worn surfaces were investigated by X-ray photoelectron spectroscopy. The results showed that the hydrophobic SA/CeBO3 were monodispersed nanospheres with an average diameter of 8 nm, and exhibited excellent dispersing stability in rapeseed oil. Meanwhile, SA/CeBO3 nanospheres were outstanding in enhancing friction-reducing and anti-wear capacities of rapeseed oil. The prominent tribological performances of SA/CeBO3 in rapeseed oil were attributed to the formation of a composite boundary lubrication film mainly composed of lubricous tribochemical species of B2O3, CeO2 and Fe2O3, and the adsorbates of SA/CeBO3 and rapeseed oil, on the tribo-surfaces.

  4. Spectroscopic Study on Eu3+ Doped Borate Glasses Containing Ag Nanoparticles and Ag Aggregates.

    Science.gov (United States)

    Fu, Shaobo; Zheng, Hui; Zhang, Jinsu; Li, Xiangping; Sun, Jiashi; Hua, Ruinian; Dong, Bin; Xia, Haiping; Chen, Baojiu

    2015-01-01

    Transparent Eu(3+)-doped borate glasses containing Ag nanoparticles and Ag aggregates with composition (40 - x) CaO-59.5B2O3-0.5Eu2O3-xAgNO3 were prepared by a simple one-step melt-quenching technique. The X-ray diffraction (XRD) patterns of the glasses reveal amorphous structural properties and no diffraction peaks belonging to metal Ag particles. Ag particles and Ag aggregates were observed from the absorption spectra. Effective energy transfers from the Ag aggregates to the Eu3+ ions were observed in the excitation spectra from monitoring the intrinsic emission of Eu3+x .5D0 --> 7F2. The glasses with higher Ag content can be effectively excited by light in a wide wavelength region, indicating that these glasses have potential application in the solid state lighting driven by semiconductor light emitting diodes (LEDs). The emission spectra of the samples with higher Ag contents exhibit plenteous spectral components covering the full visible region from violet to red, thus indicating that these glass materials possess an excellent and tunable color rendering index. The color coordinates for all the glass samples were calculated by using the intensity-corrected emission spectra and the standard data issued by the CIE (Commission International de l' Eclairage) in 1931. It was found that the color coordinates for most samples with higher Ag contents fall into the white region in the color space.

  5. Production of Zinc Borate for Pilot-Scale Equipment and Effects of Reaction Conditions on Yield

    Directory of Open Access Journals (Sweden)

    Melek BARDAKCI

    2013-05-01

    Full Text Available In this study, zinc borate (ZB was synthesized by reacting zinc oxide and boric acid in the presence of standard ZB (w/w, in terms of boric acid in order to promote crystallization. The effects of seed, H3BO3/ZnO (boric acid/zinc oxide ratio, reaction time, water volume, reaction temperature and cooling temperature on yield were investigated for pilot-scale equipment. The results indicated that the addition of seed (w/w to a saturated solution of reactants increased the yield of the reaction. The results of reaction yields obtained from either magnetically or mechanically stirred systems were compared. At various reaction times, the optimal yield was 86.78 % in a saturated aqueous solution. The products were characterized by X-ray diffraction (XRD, Fourier transform infrared spectroscopy (FT-IR and Thermogravimetric / Differential Thermal Analysis (TG/DTA. The results displayed that ZB was successfully produced under the optimized reaction conditions and the product synthesized had high thermal stability.DOI: http://dx.doi.org/10.5755/j01.ms.19.2.4432

  6. Melting and freezing of spherical bismuth nanoparticles confined in a homogeneous sodium borate glass

    Science.gov (United States)

    Kellermann, G.; Craievich, A. F.

    2008-08-01

    The melting temperature and the crystallization temperature of Bi nanoclusters confined in a sodium borate glass were experimentally determined as functions of the cluster radius. The results indicate that, on cooling, liquid Bi nanodroplets exhibit a strong undercooling effect for a wide range of radii. The difference between the melting temperature and the freezing temperature decreases for decreasing radius and vanishes for Bi nanoparticles with a critical radius R=1.9nm . The magnitude of the variation in density across the melting and freezing transitions for Bi nanoparticles with R=2nm is 40% smaller than for bulk Bi. These experimental results support a basic core-shell model for the structure of Bi nanocrystals consisting of a central crystalline volume surrounded by a structurally disordered shell. The volume fraction of the crystalline core decreases for decreasing nanoparticle radius and vanishes for R=1.9nm . Thus, on cooling, the liquid nanodroplets with R<1.9nm preserve, across the liquid-to-solid transformation, their homogeneous and disordered structure without crystalline core.

  7. Dosimetric and kinetic parameters of lithium cadmium borate glasses doped with rare earth ions

    Directory of Open Access Journals (Sweden)

    J. Anjaiah

    2014-10-01

    Full Text Available Thermoluminescence (TL characteristics of X-ray irradiated pure and doped with four different rare earth ions (viz., Pr3+, Nd3+, Sm3+ and Eu3+ Li2O–Cdo–B2O3 glasses have been studied in the temperature range 303–573 K; the pure glass has exhibited single TL peak at 466 K. When this glass is doped with different rare earth ions no additional peaks are observed but the glow peak temperature of the existing glow peak shifted gradually towards higher temperatures with gain in intensity of TL light output. The area under the glow curve is found to be maximum for Eu3+ doped glasses. The trap depth parameters associated with the observed TL peaks have been evaluated using Chen's formulae. The possible use of these glasses in radiation dosimetry has been described. The result clearly showed that europium doped cadmium borate glass has a potential to be considered as the thermoluminescence dosimeter.

  8. Study of structural, electrical, and dielectric properties of phosphate-borate glasses and glass-ceramics

    Science.gov (United States)

    Melo, B. M. G.; Graça, M. P. F.; Prezas, P. R.; Valente, M. A.; Almeida, A. F.; Freire, F. N. A.; Bih, L.

    2016-08-01

    In this work, phosphate-borate based glasses with molar composition 20.7P2O5-17.2Nb2O5-13.8WO3-34.5A2O-13.8B2O3, where A = Li, Na, and K, were prepared by the melt quenching technique. The as-prepared glasses were heat-treated in air at 800 °C for 4 h, which led to the formation of glass-ceramics. These high chemical and thermal stability glasses are good candidates for several applications such as fast ionic conductors, semiconductors, photonic materials, electrolytes, hermetic seals, rare-earth ion host solid lasers, and biomedical materials. The present work endorses the analysis of the electrical conductivity of the as-grown samples, and also the electrical, dielectric, and structural changes established by the heat-treatment process. The structure of the samples was analyzed using X-Ray powder Diffraction (XRD), Raman spectroscopy, and density measurements. Both XRD and Raman analysis confirmed crystals formation through the heat-treatment process. The electrical ac and dc conductivities, σac and σdc, respectively, and impedance spectroscopy measurements as function of the temperature, varying from 200 to 380 K, were investigated for the as-grown and heat-treated samples. The impedance spectroscopy was measured in the frequency range of 100 Hz-1 MHz.

  9. Use of borated polyethylene to improve low energy response of a prompt gamma based neutron dosimeter

    Energy Technology Data Exchange (ETDEWEB)

    Priyada, P.; Ashwini, U.; Sarkar, P.K., E-mail: pradip.sarkar@manipal.edu

    2016-05-21

    The feasibility of using a combined sample of borated polyethylene and normal polyethylene to estimate neutron ambient dose equivalent from measured prompt gamma emissions is investigated theoretically to demonstrate improvements in low energy neutron dose response compared to only polyethylene. Monte Carlo simulations have been carried out using the FLUKA code to calculate the response of boron, hydrogen and carbon prompt gamma emissions to mono energetic neutrons. The weighted least square method is employed to arrive at the best linear combination of these responses that approximates the ICRP fluence to dose conversion coefficients well in the energy range of 10{sup −8} MeV to 14 MeV. The configuration of the combined system is optimized through FLUKA simulations. The proposed method is validated theoretically with five different workplace neutron spectra with satisfactory outcome. - Highlights: • An improved method is proposed for estimating H⁎(10) using prompt gamma emissions. • A combination of BHDPE and HDPE cylinders is used as a sample. • Linear combination of prompt gamma intensities approximates ICRP-DCC closely. • Feasibility of the method was tested theoretically using workplace neutron spectra.

  10. Response of a lithium gadolinium borate scintillator in monoenergetic neutron fields.

    Science.gov (United States)

    Williams, A M; Beeley, P A; Spyrou, N M

    2004-01-01

    Accurate estimation of neutron dose requires knowledge of the neutron energy distribution in the working environment. Existing neutron spectrometry systems, Bonner spheres for example, are large and bulky, and require long data acquisition times. A portable system that could indicate the approximate neutron energy spectrum in a short time would be extremely useful in radiation protection. A composite scintillator, consisting of lithium gadolinium borate crystals in a plastic scintillator matrix, produced by Photogenics is being tested for this purpose. A prototype device based on this scintillator and digital pulse processing electronics has been calibrated using quasi-monoenergetic neutron fields at the low-scatter facility of the UK National Physical Laboratory (NPL). Energies selected were 144, 250, 565, 1400, 2500 and 5000 keV, with correction for scattered neutrons being made using the shadow cone technique. Measurements were also made in the NPL thermal neutron field. Pulse distributions collected with the digitiser in capture-gated mode are presented, and detection efficiency and energy resolution derived. For comparison, neutron spectra were also collected using the commercially available Microspec N-Probe from Bubble Technology Industries, which consists of an NE213 scintillator and a 3He proportional counter.

  11. Ultrasonic investigations of some bismuth borate glasses doped with Al2O3

    Indian Academy of Sciences (India)

    Yasser B Saddeek; Moenis A Azooz; Amr Bakr Saddek

    2015-02-01

    The velocities of longitudinal and transverse ultrasonic waves in different compositions of 5Al2O3–29Na2O–(66−)B2O$_{3}−x$Bi2O3 glass system were measured at 4 MHz at room temperature using the pulse-echo technique. The velocity data were used to determine the elastic moduli and the dimensionality of the studied glasses. The observed changes in the elastic moduli of the glasses were related to the modifier role of Bi2O3 content. The results revealed that the density increased with increasing Bi2O3 content, which was attributed to the increase in the compactness and packing of the glass network. The ultrasonic data were analysed in terms of creation of new bonds of Bi2O3 attached to the structural units of the borate network. The new bonds decreased the average crosslink density and the number of network bonds per unit volume along with a weakening of the different modes of vibrations, which in its turn decreased the ultrasonic velocity. Quantitative analysis was carried out using Makishima–Mackenzie model in order to obtain more information about the rigidity of these glasses.

  12. Comparison of Lithium Gadolinium Borate Crystal Shards in Scintillating and Nonscintillating Plastic Matrices

    CERN Document Server

    Kazkaz, Kareem; Pedretti, Marisa

    2011-01-01

    We present a method for detecting neutrons using scintillating lithium gadolinium borate crystal shards in a plastic matrix while maintaining high gamma rejection. We have procured two cylindrical detectors, 5"\\times5", containing 1% crystal by mass. Crystal shards have a typical dimension of 1 mm. One detector was made with scintillating plastic, and one with nonscintillating plastic. Pulse shape analysis was used to reject gamma ray backgrounds. The scintillating detector was measured to have an intrinsic fast fission neutron efficiency of 0.4% and a gamma sensitivity of less than 2.3 \\times 10-9, while the nonscintillating detector had a neutron efficiency of 0.7% and gamma sensitivity of (4.75\\pm3.94)\\times10-9. We determine that increasing the neutron detection efficiency by a factor of 2 will make the detector competitive with moderated 3He tubes, and we discuss several simple and straightforward methods for obtaining or surpassing such an improvement. We end with a discussion of possible applications, ...

  13. Effect of La2O3 on the structure and the properties of strontium borate glasses

    Directory of Open Access Journals (Sweden)

    Smiljanić Sonja V.

    2016-01-01

    Full Text Available The selected lanthanum-strontium-borate glasses were prepared by a conventional melt-quenching technique. The compositions of the investigated glasses were chosen to be: 5.7, 9.5, 14.3, 19.1 mol % for La2O3, 22.9, 19.1, 14.3, 9.5 for mol % SrO and 71.4 mol % for B2O3. The density, molar volume, oxygen molar volume, oxygen packing density, oxygen/boron ratios and structural transformations in the glass network were investigated according to the substitution of SrO by La2O3. The density and the molar volume increased in parallel with La2O3 content increase. Simultaneously, oxygen molar volume values increased while the oxygen packing density values decreased. A hot stage microscope (HSM and a differential thermal analysis (DTA were used to determine the characteristic temperatures. By increasing the content of lanthanum, the glass transition temperatures, changed with the same trend as the molar volume. Glass stability parameters were calculated from the temperatures obtained by DTA and HSM. The HSM results were used to obtain the viscosity curves by applying Vogel-Fulcher-Tamman (VFT equation. [Projekat Ministarstva nauke Republike Srbije, br. 172004 i br. 34001

  14. Infrared luminescence and thermoluminescence of lithium borate glasses doped with Sm3+ ions

    Directory of Open Access Journals (Sweden)

    Anjaiah J.

    2015-03-01

    Full Text Available Thermoluminescence (TL characteristics of X-ray irradiated pure and doped with Sm3+ ions Li2O-MO-B2O3 (where MO=ZnO, CaO, CdO glasses have been studied in the temperature range of 303 to 573 K. All the pure glasses exhibited single TL peaks at 382 K, 424 K and 466 K. When these glasses were doped with Sm3+ ions no additional peaks have been observed but the glow peak temperature of the existing glow peak shifted gradually towards higher temperatures with gain in intensity of TL light output. The area under the glow curve was found to be maximum for Sm3+ doped glasses mixed with cadmium oxide as a modifier. The trap depth parameters associated with the observed TL peaks have been evaluated using Chen’s formulae. The possible use of these glasses in radiation dosimetry has been described. The results clearly showed that samarium doped cadmium borate glass has a potential to be considered as a thermoluminescence dosimeter.

  15. FTIR AND SOME PHYSICAL PROPERTIES OF ALKALINE EARTH BORATE GLASSES CONTAINING HEAVY METAL OXIDES

    Directory of Open Access Journals (Sweden)

    RAMADEVUDU.G

    2011-09-01

    Full Text Available The FTIR spectra of heavy metal oxide doped borate glasses with the general formula RO-MO-B2O3 (RO= MgO, CaO, SrO and BaO, MO=ZnO, TeO2, PbO and Bi2O3 were studied in the spectral range 400-4400cm-1 toobtain information about the influence of the glass composition on the spectra. The FTIR studies revealed that MO acted differently in RO-B2O3 glass matrix and produced small variations in the glass structure. RO oxides also affected the glass structure slightly due to mixed oxide effect. However the structural groupings present ineach series of glasses are not much affected by the composition. The effect of composition on some physical properties like density, molar volume was also carried out. The increase in the values of physical parameters such as density and glass transition temperature is attributed to conversion of [BO3]3- triangular units into BO4-tetrahedral units.

  16. Oxidation of ethyl ether on borate glass: chemiluminescence, mechanism, and development of a sensitive gas sensor.

    Science.gov (United States)

    Hu, Jing; Xu, Kailai; Jia, Yunzhen; Lv, Yi; Li, Yubao; Hou, Xiandeng

    2008-11-01

    A gas sensor was developed by using the chemiluminescence (CL) emission from the oxidation of ethyl ether by oxygen in the air on the surface of borate glass. Theoretical calculation, together with experimental investigation, revealed the main CL reactions: ethyl ether is first oxidized to acetaldehyde and then to acetic acid, during which main luminous intermediates such as CH 3CO (*) are generated and emit light with a peak at 493 nm. At a reaction temperature of 245 degrees C, the overall maximal emission was found at around 460 nm, and the linear range of the CL intensity versus the concentration of ethyl ether was 0.12-51.7 microg mL (-1) ( R = 0.999, n = 7) with a limit of detection (3sigma) of 0.04 microg mL (-1). Interference from foreign substances including alcohol (methanol, ethanol and isopropanol), acetone, ethyl acetate, n-hexane, cyclohexane, dichloromethane, or ether ( n-butyl ether, tetrahydrofuran, propylene oxide, isopropyl ether and methyl tert-butyl ether) was not significant except a minimal signal from n-butyl ether (ethyl ether.

  17. Breastfeeding reduces postpartum weight retention

    DEFF Research Database (Denmark)

    Baker, Jennifer Lyn; Gamborg, Michael; Heitmann, Berit L;

    2008-01-01

    ) reduced PPWR at 6 and 18 mo after adjustment for maternal prepregnancy body mass index (BMI) and gestational weight gain (GWG). RESULTS: GWG was positively (P Breastfeeding was negatively associated with PPWR in all women but those......BACKGROUND: Weight gained during pregnancy and not lost postpartum may contribute to obesity in women of childbearing age. OBJECTIVE: We aimed to determine whether breastfeeding reduces postpartum weight retention (PPWR) in a population among which full breastfeeding is common and breastfeeding...... duration is long. DESIGN: We selected women from the Danish National Birth Cohort who ever breastfed (>98%), and we conducted the interviews at 6 (n = 36 030) and 18 (n = 26 846) mo postpartum. We used regression analyses to investigate whether breastfeeding (scored to account for duration and intensity...

  18. REVIEW OF THE OCCURRENCE OF TWO NEW MINERALS IN THE EMET BORATE DEPOSIT, TURKEY: EMETITE, Ca7Na3K(SO4)9, and FONTARNAUITE, Na2Sr(SO4)[B5O8(OH)](H2O)2

    OpenAIRE

    Helvaci, Cahit

    2015-01-01

    The Emet borate deposit is situated in the middle of the known borate deposits of western Anatolia. Emet is the world biggest colemanite-probertite deposit which is located in the upper section of the volcano-sedimentary sequence of the Emet basin. Emet borate deposit is unique and has unusual mineral associations. The principal minerals in the Emet borate deposit are colemanite with minor probertite, ulexite and hydroboracite. In addition, rare species such as meyerhofferite, veatchite-A, tu...

  19. High-Pressure Synthesis of Cd(NH₃)₂[B₃O₅(NH₃)]₂: Pioneering the Way to the Substance Class of Ammine Borates.

    Science.gov (United States)

    Sohr, Gerhard; Ciaghi, Nina; Schauperl, Michael; Wurst, Klaus; Liedl, Klaus R; Huppertz, Hubert

    2015-05-18

    To date, the access to the substance class of borates containing nitrogen, for example, nitridoborates, oxonitridoborates, or amine borates, was an extreme effort owing to the difficult starting materials and reaction conditions. Although a number of compounds containing boron and nitrogen are known, no adduct of ammonia to an inorganic borate has been observed so far. A new synthetic approach starting from the simple educts CdO, B2O3, and aqueous ammonia under conditions of 4.7 GPa and 800 °C led to the synthesis of Cd(NH3)2[B3O5(NH3)]2 as the first ammine borate. We thoroughly characterized this compound on the basis of low-temperature single-crystal and powder X-ray diffraction data, IR and Raman spectroscopy, and by quantum theoretical calculations. This contribution shows that the adduct of NH3 to the BO3 group of a complex B-O network can be stabilized, opening up a fundamentally new synthetic route to nitrogen-containing borates.

  20. Low-Temperature Sintering and Microwave Dielectric Properties of Zn2SiO4 Ceramic Added with Crystalline Zinc Borate

    Science.gov (United States)

    Chaware, Varsha; Deshmukh, Ravindra; Sarode, Chetan; Gokhale, Suresh; Phatak, Girish

    2015-07-01

    The physical and dielectric properties of composites of known microwave materials, Zn2SiO4 and Zn3B2O6, prepared by solid-state reaction, were investigated with the purpose of developing a low-loss dielectric material for low-temperature co-fired ceramic applications. An off-stoichiometric phase of Zn2SiO4 with extra SiO2 was used to avoid the occurrence of unreacted ZnO. During sintering, zinc borate was found to partially react with residual SiO2 to form Zn2SiO4. The residual zinc borate was converted to a boron-rich glassy phase which helped to reduce the sintering temperature of the composite. Good relative sintering density (>90%) at temperatures below the melting temperature of zinc borate is indicative of a sintering mechanism of diffusion-based mass transfer. Composites containing 15 wt.% zinc borate, 2.5 wt.% lithium carbonate and 20 wt.% zinc borate in zinc silicate had dielectric constants of 6.8 and 6.1, quality factors (Q×f) of 48,800 and 94,300 GHz when sintered at 900°C and 950°C, respectively. These quality factor results are close to the best values reported for zinc silicate at these sintering temperatures.

  1. How to quantify conduits in wood?

    Directory of Open Access Journals (Sweden)

    Alexander eScholz

    2013-03-01

    Full Text Available Vessels and tracheids represent the most important xylem cells with respect to long distance water transport in plants. Wood anatomical studies frequently provide several quantitative details of these cells, such as vessel diameter, vessel density, vessel element length, and tracheid length, while important information on the three dimensional structure of the hydraulic network is not considered. This paper aims to provide an overview of various techniques, although there is no standard protocol to quantify conduits due to high anatomical variation and a wide range of techniques available. Despite recent progress in image analysis programs and automated methods for measuring cell dimensions, density, and spatial distribution, various characters remain time-consuming and tedious. Quantification of vessels and tracheids is not only important to better understand functional adaptations of tracheary elements to environment parameters, but will also be essential for linking wood anatomy with other fields such as wood development, xylem physiology, palaeobotany, and dendrochronology.

  2. Reactivity and burnout of wood fuels

    DEFF Research Database (Denmark)

    Dall'Ora, Michelangelo

    pyrolysis chars were significantly more reactive than slow pyrolysis chars (for the same activation energy, the pre-exponential factor was up to 2 orders of magnitude greater for chars increased. The amount and composition of the ash forming matter of the wood fuels is believed to play an important role......This thesis deals with the combustion of wood in pulverised fuel power plants. In this type of boiler, the slowest step in the wood conversion process is char combustion, which is one of the factors that not only determine the degree of fuel burnout, but also affect the heat release profile...... in the boiler and thereby the overall operation and efficiency of the plant. Chapter 1 consists of an introduction to thermal conversion of biomass fuels as well as a description of a Danish power plant where a measuring campaign was carried out as part of this project. Chapter 2 is a brief literature review...

  3. Moisture-driven fracture in solid wood

    DEFF Research Database (Denmark)

    Larsen, Finn; Ormarsson, Sigurdur; Olesen, John Forbes

    2011-01-01

    Moisture-induced fractures in solid timber create considerable problems for both building industries and sawmills. Cracks caused by kiln-drying of solid timber are extremely difficult to predict. This paper reports on experiments concerned with methods of reducing cracks in wood and with the crac......Moisture-induced fractures in solid timber create considerable problems for both building industries and sawmills. Cracks caused by kiln-drying of solid timber are extremely difficult to predict. This paper reports on experiments concerned with methods of reducing cracks in wood...... process, suggesting that sealing the ends of timber logs while in the green moisture state could considerably reduce the development of end-cracks. The initial moisture content and the shrinkage properties of the wood varied markedly from pith to bark. The importance of taking material inhomogeneities...

  4. Properties of Wood/Montmorillonite Nanocomposites

    Institute of Scientific and Technical Information of China (English)

    LV Wenhua; ZHAO Guangjie

    2006-01-01

    With montmorillonite (MMT) organically modified as organophilic-MMT (OMMT) and water-soluble phenol formaldehyde resin (PF) as intermediate, the nanocomposites of Chinese fir (Cunninghamia lanceolata) wood and MMT, i.e. WMNC, were prepared via nano intercalation compounding, some properties of WMNC were analyzed. Results show that, compared with Chinese fir wood and its PF-impreg, WMNC has lower humidity and water absorption, better dimension stability, higher longitudinal compressive strength, abrasive resistance, fire-resistance, and water-leaching resistance with a very low mass ratio about 3% of MMT. The nano intercalation compounding of wood and exfoliated MMT nanolamellae is very promising. More studies should be carried out to fully reveal the nanosize effects and the special properties of WMNC.

  5. Wood flow problems in the Swedish forestry

    Energy Technology Data Exchange (ETDEWEB)

    Carlsson, Dick [Forestry Research Inst. of Sweden, Uppsala (Sweden); Roennqvist, M. [Linkoeping Univ. (Sweden). Dept. of Mathematics

    1998-12-31

    In this paper we give an overview of the wood-flow in Sweden including a description of organization and planning. Based on that, we will describe a number of applications or problem areas in the wood-flow chain that are currently considered by the Swedish forest companies to be important and potential in order to improve overall operations. We have focused on applications which are short term planning or operative planning. We do not give any final results as much of the development is currently ongoing or is still in a planning phase. Instead we describe what kind of models and decision support systems that could be applied in order to improve co-operation within and integration of the wood-flow chain 13 refs, 20 figs, 1 tab

  6. Bamboo and Wood in Musical Instruments

    Science.gov (United States)

    Wegst, Ulrike G. K.

    2008-08-01

    Over centuries and millennia, our ancestors worldwide found the most appropriate materials for increasingly complex acoustical applications. In the temperate climate of Europe, where the instruments of the Western symphony orchestra were developed and perfected, instrument makers still primarily take advantage of the unique property combination and the aesthetic appeal of wood. In all other continents, one material dominates and is frequently chosen for the manufacture of wind, string, and percussion instruments: the grass bamboo. Here, we review from a materials science perspective bamboo's and wood's unique and highly optimized structure and properties. Using material property charts plotting acoustic properties such as the speed of sound, the characteristic impedance, the sound radiation coefficient, and the loss coefficient against one another, we analyze and explain why bamboo and specific wood species are ideally suited for the manufacture of xylophone bars and chimes, flutes and organs, violins and zithers, violin bows, and even strings.

  7. Research advance in wood composites in China

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    Wood composites can generally be classified in three parts: laminated composites, mixed composites and penetrated composites. Every part has its own characteristic and can be further divided. This paper introduces the history and the state of development of wood composites in China. The research about glue-laminated timber is rare and the industry hardly comes to being. A great of achievements have been obtained in mixed composites and it is well industrialized. Many studies on scrimber have been done and the Chinese researchers are looking for a feasible way to develop the scrimber industry in China. Chinese researchers also spent so much energy in studying wood plastic composites (WPC), but it has not been industrialized due to the high cost.

  8. How to quantify conduits in wood?

    Science.gov (United States)

    Scholz, Alexander; Klepsch, Matthias; Karimi, Zohreh; Jansen, Steven

    2013-01-01

    Vessels and tracheids represent the most important xylem cells with respect to long distance water transport in plants. Wood anatomical studies frequently provide several quantitative details of these cells, such as vessel diameter, vessel density, vessel element length, and tracheid length, while important information on the three dimensional structure of the hydraulic network is not considered. This paper aims to provide an overview of various techniques, although there is no standard protocol to quantify conduits due to high anatomical variation and a wide range of techniques available. Despite recent progress in image analysis programs and automated methods for measuring cell dimensions, density, and spatial distribution, various characters remain time-consuming and tedious. Quantification of vessels and tracheids is not only important to better understand functional adaptations of tracheary elements to environment parameters, but will also be essential for linking wood anatomy with other fields such as wood development, xylem physiology, palaeobotany, and dendrochronology.

  9. Genetic improvement of trees for wood production, with particular refeference to wood traits

    Directory of Open Access Journals (Sweden)

    Nocetti M

    2008-03-01

    Full Text Available The use of selected propagation material from tree improvement programs is expected to lead to a more homogenous product, generally appreciated by industry. So far, breeding strategy have been mainly targeted to maximize acclimation/adaptation to specific environment conditions, tree growth and disease resistance, but it is not obvious that such strategy might lead to improvement of wood characteristics at the same time. Therefore, it seems important to introduce wood traits improvement as specific target of the selection process in tree breeding programs, and/or to assess heritability of wood technological properties of trees previously selected based on different criteria. Investigations reported so far have revealed that several wood traits are under a medium to high genetic control. The main goal of this work is to discuss the suitability of wood traits improvement as main target of specific breeding programs, with particular attention to wood technological characteristics to be considered in the tree selection process. Finally, we focused on noble hardwoods, that have been the target species for many improvement programs developed in Italy, and particularly on wild cherry, where studies on the genetic control of wood traits are rare.

  10. Characteristics of heat-treated Turkish pine and fir wood after ThermoWood processing.

    Science.gov (United States)

    Kol, Hamiyet Sahin

    2010-11-01

    The Finnish wood heat treatment technology ThermoWood, was recently introduced to Turkey. Data about the mechanical and physical properties of Turkish wood species are important for industry and academia. In this study two industrially important Turkish wood species, pine (Pinus nigraArnold.) and fir (Abies bornmülleriana Matf.) were heat-treated using the ThermoWood process. Pine and fir samples were thermally modified for 2 hr at 212 and 190 degrees C, respectively. The modulus of rupture (MOR), modulus of elasticity in bending (MOE), impact bending strength (IBS), and compression strength (CS), in addition to swelling (Sw) and shrinkage (Sh) of thermally-modified wood were examined. The results indicate that the heat treatment method clearly decreased the MOR, MOE and lBS of pine and fir. However, a small increase was observed for CS values of heat treated wood species. The most affected mechanical properties were MOR and lBS for both pine and fir. The reduction in MOE was smaller than that in MOR and lBS. Volumetric shrinkage and swelling of these species were also improved by approximately half. In Addition, the changes in the mechanical and physical properties studied in pine were larger than that of fir.

  11. 76 FR 24089 - Credit Risk Retention

    Science.gov (United States)

    2011-04-29

    ... Department of Housing and Urban Development 24 CFR Part 267 Credit Risk Retention; Proposed Rule #0;#0..., and HUD (the Agencies) are proposing rules to implement the credit risk retention requirements of... securitizer of asset-backed securities to retain not less than five percent of the credit risk of the...

  12. 76 FR 34010 - Credit Risk Retention

    Science.gov (United States)

    2011-06-10

    ...-AA43 DEPARTMENT OF HOUSING AND URBAN DEVELOPMENT 24 CFR Part 267 RIN 2501-AD53 Credit Risk Retention... a joint notice of proposed rulemaking for public comment to implement the credit risk retention... Reform and Consumer Protection Act (``Credit Risk NPR'' or ``proposed rule''). Due to the complexity...

  13. Novel Word Retention in Sequential Bilingual Children

    Science.gov (United States)

    Kan, Pui Fong

    2014-01-01

    Children's ability to learn and retain new words is fundamental to their vocabulary development. This study examined word retention in children learning a home language (L1) from birth and a second language (L2) in preschool settings. Participants were presented with sixteen novel words in L1 and in L2 and were tested for retention after…

  14. Managing human resources to improve employee retention.

    Science.gov (United States)

    Arnold, Edwin

    2005-01-01

    Managers face increased challenges as the demand for health care services increases while the supply of employees with the requisite skills continues to lag. Employee retention will become more important in the effort to service health care needs. Appropriate human resource management strategies and policies implemented effectively can significantly assist managers in dealing with the employee retention challenges ahead.

  15. 12 CFR 609.945 - Records retention.

    Science.gov (United States)

    2010-01-01

    ... 12 Banks and Banking 6 2010-01-01 2010-01-01 false Records retention. 609.945 Section 609.945 Banks and Banking FARM CREDIT ADMINISTRATION FARM CREDIT SYSTEM ELECTRONIC COMMERCE Standards for Boards and Management § 609.945 Records retention. Records stored electronically must be accurate,...

  16. Carbonization of wood at 400°C for composite materials

    Science.gov (United States)

    Randrianarisoa, Bernard Laurent

    The carbonization process for large pieces of wood was investigated to produce a solid carbonized wood skeleton precursor that retains the cellular structure of the wood without the formation of cracks and with reduced longitudinal deformation. Two carbonization schedules were designed for the conversion of sugar maple (Acer saccharum) and southern pine ( Pinus spp) into amorphous carbon at a heat treatment temperature of 400°C. Samples from commercial lumber were carbonized to produce the materials. Each schedule was designed meticulously through DTA-TGA for each wood species. The materials were characterized by their average yields, dimensional changes, density, porosity, SEM and mechanical testing. Also, the materials were used as solid carbon skeletons for making resin-infused carbon composites. Structural epoxy resin was infused into the carbon material template and cured at a maximum temperature of 125°C. The depth of the resin infusion was assessed by SEM examination and the retention was analyzed by total weight gain. The strength and the stiffness of the composite materials were evaluated through mechanical testing. It was demonstrated that southern pine and sugar maple should require different heat treatment schedules for carbonization. The schedules were able to reduce the longitudinal deformation and to keep the final products free of cracks. The yield averaged around 28% for both southern pine and sugar maple. Carbonized southern pine exhibited lower density and higher porosity than carbonized sugar maple. The resin treatment increased specific gravity of carbonized materials by 9.6% and 11.6% for maple and southern pine respectively. The resin infusion improved the average MOR values by 140% and 275%. MOE of the composites was similar to that of pure epoxy.

  17. Effects of wood polymers and extractives on the adsorption of wet-end chemicals and the properties of the sheet - MPKY 03

    Energy Technology Data Exchange (ETDEWEB)

    Bobacka, V.; Lindholm, J.; Nurmi, M.; Naesman, J. [Aabo Akademi, Turku (Finland). Lab. of Paper Chemistry; Holmbom, B.; Konn, J.; Sundberg, A.; Willfoer, S. [Aabo Akademi, Turku (Finland). Lab. of Forest Products Chemistry

    1998-12-31

    The effects of deposition of dissolved and colloidal substances (disco, DCS) together with fixing agents on the wet end chemistry, and the paper quality have been studied. Increased amounts of wood resin in handsheets results in lower strength properties and friction of the sheets. Addition of isolated polysaccharides together with wood resin results in higher strength properties compared, at the same resin content, to sheets without added polysaccharides. Disco substances released from TMP were adsorbed/deposited onto different fillers. It is possible to determine the distribution of aggregated wood resin in handsheets of kraft pulp by confocal laser scanning microscopy. Addition of iron salts to a TMP suspension results in a decrease in the brightness of the fibers. The adsorption of cationic starch and cationic polyacrylamide was studied as well as the flocculation of a peroxide bleached TMP and mixture of TMP and kraft pulp in the presence of retention aids and fixing agents. The fixing agent had a minor effect on the flocculation in peroxide bleached TMP, while cationic starch induced flocculation after a threshold. When added together, cationic starch induced flocculation immediately. The retention of carbohydrates in the mixture was not much influenced by the presence of fixing agents and retention aids, but the extractives were efficiently retained. Colloidal substances adsorb both cationic starch and polyacrylamide. Of the dissolved substances, pectic acids are most efficiently aggregated. (orig.)

  18. Lung function: occupational exposure to wood dust

    Directory of Open Access Journals (Sweden)

    Baran S

    2009-12-01

    Full Text Available Abstract Objectives Occupational exposure to wood dust has been shown to cause several respiratory disorders, such as allergic rhinitis, chronic bronchitis, asthma, sino-nasal adenocarcinoma, and impairment of lung function. The aim of the study was to estimate lung function (in the woodworking industry among workers employed by wood processing, who run the risk of being expose to wood dust. Methods The study concerns a group of 70 workers aged 24-55. All the workers underwent general and laryngological examination. A group of 20 workers, working at the positions where dustiness exceeded TLV (threshold limit value took X-ray of the chest and spirometry. The following parameters were measured: VC, IC, ERV, TV, BF, FEV1, FVC, PEF, MEF25-75, FEV1%FVC, FEV1%VC. The data are presented as means ± SD and the authors applied references values according to ERS guidelines. Results The results show that there was no decline in FEV1 (3.7 ± 0.7 and FVC (4.5 ± 0.8. Normal lung function was defined as FEV1/VC ratio ≥0.7. None of the tested workers had obstructive pattern in spirometry. The mean FEV1%VC was 77.1 ± 10.2. These results suggest that wood dust exposure might not lead to significant pulmonary damage. Conclusions These data do not corroborate that wood dust plays significant role in lung function impairment. Future studies of respiratory health among workers exposed to wood dust are needed.

  19. Chemical and physical characterization of emissions from birch wood combustion in a wood stove

    Science.gov (United States)

    Hedberg, Emma; Kristensson, Adam; Ohlsson, Michael; Johansson, Christer; Johansson, Per-Åke; Swietlicki, Erik; Vesely, Vaclav; Wideqvist, Ulla; Westerholm, Roger

    The purpose of this study was to characterize the emissions of a large number of chemical compounds emitted from birch wood combustion in a wood stove. Birch wood is widely used as fuel in Swedish household appliances. The fuel load was held constant during six experiments. Particles dust, range 30-330 for the former and 0.8±0.15 for the latter. The source profile of common elements emitted from wood burning differed from that found on particles at a street-level site or in long-distance transported particles. The ratio toluene/benzene in this study was found to be in the range 0.2-0.7, which is much lower than the ratio 3.6±0.5 in traffic exhaust emissions. Formaldehyde and acetone were the most abundant compounds among the volatile ketones and aldehydes. The emission factor varied between 180-710 mg/kg wood for formaldehyde and 5-1300 mg/kg wood for acetone. Of the organic acids analyzed (3,4,5)-trimethoxy benzoic acid was the most abundant compound. Of the PAHs reported, fluorene, phenanthrene, anthracene, fluoranthene and pyrene contribute to more than 70% of the mass of PAH. Of the elements analyzed, K and Si were the most abundant elements, having emission factors of 27 and 9 mg/kg wood, respectively. Although fluoranthene has a toxic equivalence factor of 5% of benzo(a)pyrene (B(a)P), it can be seen that the toxic potency of fluoranthene in wood burning emissions is of the same size as B(a)P. This indicates that the relative carcinogenic potency contribution of fluoranthene in wood smoke would be about 40% of B(a)P.

  20. CHARACTERISTICS OF LAMINATED WOOD OF LOGGING WASTE OF THREE NATURAL FOREST WOOD SPECIES

    Directory of Open Access Journals (Sweden)

    Jamaludin Malik

    2005-03-01

    Full Text Available This research is aimed to assess the characteristics of 3-ply laminated wood assembly incorporating wood waste belonged to three species i.e. bengkal (Nauclea sp., pisang-pisang (Alponsea teysmanii Boerl, and jambu-jambu (Eugenia spp..  The waste was procured from logged natural forests. The used adhesive was tannin-resorcinol formaldehyde.  The lamination experiment was replicated three times. The assessed characteristics were moisture content, density, formaldehyde emission, bonding strength, wood defect, and static bending strength. The resulting 3-ply laminated wood assembly (beam has a moisture content at 4.00 - 13.90%, density 0.30 - 0.68 gram per cm3, and formaldehyde emission 0.323 - 3.199 mg per liter that tended to increase with the decrease in density of the laminated wood.  The bonding strength of the laminated wood ranges varied from 47.14 to 107.52 kg per cm2  (dry testing and 40.76 - 79.57 kg per cm2  (wet testing.  Likewise, wood defect was about 80 - 100% (dry test and 20 - 80% (wet test.  Static bending strength varied from 455.62 - 843.36 kg per cm2 (for MOE and from 35,985.49 to 104,332.63 kg per cm2 (for MOR. Based on these data, the three wood waste species afforded good bending strength and they were suitable for reconstituting material for exterior-type laminated wood beam.

  1. Optimising hydrogen bonding in solid wood

    DEFF Research Database (Denmark)

    Engelund, Emil Tang

    2009-01-01

    The chemical bonds of wood are both covalent bonds within the wood polymers and hydrogen bonds within and between the polymers. Both types of bonds are responsible for the coherence, strength and stiffness of the material. The hydrogen bonds are more easily modified by changes in load, moisture...... and temperature. The distribution of bond lengths was examined using infrared spectroscopy (ATR-FTIR) both prior to treatments and after. The results show that the absorbance bands of the spectra related to the hydroxyl and carboxyl stretching vibrations were changed by the treatments. Apparently, the first...

  2. BOREAS TE-2 Wood Respiration Data

    Science.gov (United States)

    Ryan, Michael G.; Lavigne, Michael; Hall, Forrest G. (Editor); Papagno, Andrea (Editor)

    2000-01-01

    The BOREAS TE-2 team collected several data sets in support of its efforts to characterize and interpret information on the respiration of the foliage, roots, and wood of boreal vegetation. This data set contains measurements of wood respiration conducted in the NSA during the growing season of 1994. The data are stored in tabular ASCII files. The data files are available on a CD-ROM (see document number 20010000884), or from the Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC).

  3. BOREAS TE-2 Continuous Wood Respiration Data

    Science.gov (United States)

    Hall, Forrest G. (Editor); Papagno, Andrea (Editor); Ryan, Michael G.; Lavigne, Michael

    2000-01-01

    The BOREAS TE-2 team collected several data sets in support of its efforts to characterize and interpret information on the respiration of the foliage, roots, and wood of boreal vegetation. This data set contains measurements of wood respiration measured continuously (about once per hour) in the NSA during the growing season of 1994. The data are stored in tabular ASCII files. The data files are available on a CD-ROM (see document number 20010000884), or from the Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC).

  4. International Trade of Wood Pellets (Brochure)

    Energy Technology Data Exchange (ETDEWEB)

    2013-05-01

    The production of wood pellets has increased dramatically in recent years due in large part to aggressive emissions policy in the European Union; the main markets that currently supply the European market are North America and Russia. However, current market circumstances and trade dynamics could change depending on the development of emerging markets, foreign exchange rates, and the evolution of carbon policies. This fact sheet outlines the existing and potential participants in the wood pellets market, along with historical data on production, trade, and prices.

  5. USE OF CANDEIA’S (Eremanthus erythropappus WASTE WOOD

    Directory of Open Access Journals (Sweden)

    Rosimeire Cavalcante dos Santos

    2008-09-01

    Full Text Available The candeia (Eremanthus erythropappus is a native forest species with multiple uses and specially utilized as essential oils source. The use of the candeia´s waste wood after oil extraction for particle panels production becomes a viable alternative, avoiding environmental problems and increasing the availability of these products in the consuming market. This work verified the viability of producing wood-cement panels using waste wood generated after the extraction of candeia’s oil, in association with pinus and eucalipto woods. The experiment was installed according to a completely randomized design with three repetitions. The treatments were arranged according to a factorial 2 x 3 scheme (two wooden species and three replacement percentages of the woods by candeia’s waste. The results of the physical and mechanical property tests showed high potentiality of candeia waste wood, after oil extraction, in association with pinus and eucalipto wood for manufacturing wood-cement panels.

  6. Investigation of modified cottonseed protein adhesives for wood composites

    Science.gov (United States)

    Several modified cottonseed protein isolates were studied and compared to corresponding soy protein isolates for their adhesive properties when bonded to wood composites. Modifications included treatments with alkali, guanidine hydrochloride, sodium dodecyl sulfate (SDS), and urea. Wood composites...

  7. Relationships within balsaminoid Ericales: a wood anatomical approach

    NARCIS (Netherlands)

    Lens, F.; Dressler, S.; Jansen, S.; Van Evelghem, L.; Smets, E.

    2005-01-01

    Wood samples of 49 specimens representing 31 species and 11 genera of woody balsaminoids, i.e., Balsaminaceae, Marcgraviaceae, Pellicieraceae, and Tetrameristaceae, were investigated using light microscopy and scanning electron microscopy. The wood structure of Marcgraviaceae, Pellicieraceae, and Te

  8. PRESERVATIVE LEACHING FROM WEATHERED CCA-TREATED WOOD

    Science.gov (United States)

    Disposal of discarded CCA-treated wood in landfills raises concerns with respect to leaching of preservative compounds. When unweathered CCA-treated wood is leached using the toxicity characteristic leaching procedure (TCLP), arsenic concentrations exceed the toxicity characteris...

  9. Comparison between accelerated thermo-hydro aged wood and naturally aged wood

    OpenAIRE

    Froidevaux, Julien; Volkmer, Thomas; Gril, Joseph; Fioravanti, Marco; Navi, Parviz

    2011-01-01

    The effects of aging in wood in term of physical, mechanical and chemical degradation has been studied first by Jiro Kohara [1] and more recently by Erhardt et al. [2-3] and Obataya [4]. It has been observed that similar degradation can be found in thermo-hydro (TH) treated wood [4]. The aim of this study is to compare the mechanical behavior of naturally aged and accelerate TH wood in the radial direction. A first pressure vessel with controllable temperature, oxygen pressure and relative hu...

  10. Economics of marketing wood fuel in south western Nigeria

    OpenAIRE

    OLUGBIRE O.O.; OPUTE O.H.; AREMU F.J.; OJEDOKUN C.A.; ADISA A.

    2016-01-01

    Marketing of fuel wood is an important source of livelihood for most parts of Nigeria. The study examined the economics of marketing of wood fuel in south western Nigeria with a view to determine the socio-economic characteristics of the marketers, the profitability of marketing wood fuel, the market structure and constraints to profitability. Data for the study were obtained from a total sample of 100 randomly selected wood fuel marketers through interviews schedules and application of struc...

  11. Flammability Properties of Composites of Wood Fiber and Recycled Plastic

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Flammability properties of composites of wood fiber and recycled plastic were evaluated by the cone calorimeter and oxygen index chamber. Results were shown as follows: 1) Wood-PVC composite showed worse thermal stability on time to ignition (TTI) and mean heat release rate (MHRR), but better performance on heat release rate (HRR) and mean efficient heat of combustion (MEHC); wood-PP composite had better thermal stability properties, but was worse on other fire performance; 2) Compared with wood-PVC composi...

  12. The Wood Anatomy of Rubiaceae tribes Anthospermeae and Paederieae

    OpenAIRE

    Koek-Noorman, J.; Puff, Ch.

    1983-01-01

    Detailed wood anatomical descriptions are given for the genera Anthospermum, Nenax, Phyllis, Carpacoce, Coprosma, Neogaillonia, Crocyllis, Plocama and Spermadictyon, and miscellaneous wood anatomical data on the genera Normandia, Pomax, Opercularia, Leptodermis and Aitchisonia. The wood anatomical variation within the large genus Anthospermum is discussed. Secondary woodiness is likely to occur in a number of Anthospermum species; other species of the genus have “normal” wood structure or are...

  13. Reactivity and burnout of wood fuels

    Energy Technology Data Exchange (ETDEWEB)

    Dall' Ora, M.

    2011-07-01

    This thesis deals with the combustion of wood in pulverised fuel power plants. In this type of boiler, the slowest step in the wood conversion process is char combustion, which is one of the factors that not only determine the degree of fuel burnout, but also affect the heat release profile in the boiler and thereby the overall operation and efficiency of the plant. Chapter 1 consists of an introduction to thermal conversion of biomass fuels as well as a description of a Danish power plant where a measuring campaign was carried out as part of this project. Chapter 2 is a brief literature review of different aspects relevant to wood combustion, including wood structure and composition, wood pyrolysis, wood char properties and wood char oxidation. The full scale campaign, which is the subject of Chapter 3, included sampling of wood fuel before and after milling and sampling of gas and particles at the top of the combustion chamber. The collected samples and data are used to obtain an evaluation of the mills in operation at the power plant, the particle size distribution of the wood fuel, as well as the char conversion attained in the furnace. In Chapter 4 an experimental investigation on the relation between pyrolysis of wood in boiler-like conditions and wood char properties is presented. Chars from pine and beech wood were produced by fast pyrolysis in an entrained flow reactor and by slow pyrolysis in a thermogravimetric analyser. The influence of pyrolysis temperature, heating rate and particle size on char yield and morphology was investigated. The applied pyrolysis temperature varied in the range 673-1673 K for slow pyrolysis and 1073-1573 K for fast pyrolysis. The chars were oxidised in a thermogravimetric analyser and the mass loss data were used to determine char oxidation reactivity. Char yield from fast pyrolysis (104-105 K/s) was as low as 1-6% on a dry ash free basis, whereas it was about 15-17% for slow pyrolysis (10-20 K/min); char yield decreased as

  14. Effect of technological parameters and wood properties on cutting power in plane milling of juvenile poplar wood

    Directory of Open Access Journals (Sweden)

    Barcík Štefan

    2008-10-01

    Full Text Available This paper presents the results of experimental measurements aimed at observing the effect of technological parameters (cutting speed vc and feed speed vf , type of wood (juvenile wood and mature wood andwood species (aspen Populus tremula, L. and hybrid poplar Populus x Euramericana „Serotina“ on cutting power during plane milling of poplar wood. The results showed the reduction of cutting power with the decrease of cutting speed and feed speed. Lower cutting power was also measured in milling hybrid poplar than in milling aspen. The test also confirmed the effect of different anatomical and chemical structure of juvenile wood in relation to mature wood on different physical and mechanical properties of such wood and hence also on the cutting power in processing juvenile wood.

  15. STOCHASTIC HUMAN EXPOSURE AND DOSE SIMULATION MODEL FOR THE WOOD PRESERVATIVE SCENARIO (SHEDS-WOOD), VERSION 2 MODEL SAS CODE

    Science.gov (United States)

    Concerns have been raised regarding the safety of young children contacting arsenic and chromium residues while playing on and around Chromated Copper Arsenate (CCA) treated wood playground structures and decks. Although CCA registrants voluntarily canceled treated wood for resi...

  16. 30 CFR 77.1913 - Fire-resistant wood.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Fire-resistant wood. 77.1913 Section 77.1913 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH... Shaft Sinking § 77.1913 Fire-resistant wood. Except for crossties, timbers, and other wood...

  17. The wood anatomy of Gardenieae, Ixoreae and Mussaendeae (Rubiaceae)

    NARCIS (Netherlands)

    Koek-Noorman, Jifke

    1972-01-01

    The tribe Gardenieae in the restricted delimitation proposed by Bremekamp and Verdcourt is wood anatomically homogeneous. The genera of the Ixoreae studied by me also agree with each other in wood structure. Within the tribe Mussaendeae in the delimitation accepted by Schumann the wood anatomy shows

  18. Bacterial community succession in pine-wood decomposition

    NARCIS (Netherlands)

    Kielak, Anna; Scheublin, Tanja; Mendes, L.W.; Van Veen, Johannes A; Kuramae, Eiko Eurya

    2016-01-01

    BACKGROUND: Though bacteria and fungi are common inhabitants of decaying wood, little is known about the relationship between bacterial and fungal community dynamics during natural wood decay. Based on previous studies involving inoculated wood blocks, strong fungal selection on bacteria abundance a

  19. 7 CFR 2902.42 - Wood and concrete sealers.

    Science.gov (United States)

    2010-01-01

    ... Items § 2902.42 Wood and concrete sealers. (a) Definition. (1) Products that are penetrating liquids formulated to protect wood and/or concrete, including masonry and fiber cement siding, from damage caused by... 7 Agriculture 15 2010-01-01 2010-01-01 false Wood and concrete sealers. 2902.42 Section...

  20. Poisoned Playgrounds: Arsenic in "Pressure-Treated" Wood.

    Science.gov (United States)

    Sharp, Renee; Walker, Bill

    This study of 180 pressure-treated wood samples shows that treated wood is a much greater source of arsenic exposure for children than arsenic-contaminated drinking water. The report determines that an average 5-year-old, playing less than 2 weeks on a chromated-copper-arsenate-treated (CCA) wood play set would exceed the lifetime cancer risk…