bluuebunny/crossref_metadata_2025 huggingface dataset:
Study on the C80 High-Strength Rock Chips Concrete
Authors: Yang Yi Bo , Chen Hao Man , Wu Shu Min , Peng Yi Xin , Li Can Kun , Zheng Wu Bin , Lin Zhen Lin , Guo Wen Ying
Published: April 2011

Rock chips is a potential substitutable material for river sand, which can effectively solve the shortage problem of the river sand in concrete. At present most studies are about the rock chips concrete concentrate on the normal-strength concrete. The studies about rock chips as a substitution for river sand in C80 high-strength concrete were carried out. At first the basic physical properties of raw material are analyzed and the performance requirements of the concrete are confirmed. And then on the basis of the river sand concrete, the influence of the dosage of rock chips on the C80 high-strength concrete at the same water-binder ratio was studied. The particle size of rock chips larger than 4.75mm was considered as the coarse aggregate. The results showed that the C80 high-strength rock chips concrete can be prepared by increasing the dosage of superplasticizer and binder. The early age strength of high-strength rock chips concrete is higher than that of river sand concrete, while the contrary results of the long-term strength. Considering lots of fine powder in the rock chips, the coarse sand and rock chips are mixed to be used, the mixing ratio needs to be determined by experiments. In the high-strength concrete, the rock chips with good particle size distribution and with lower content of particle size larger than 4.75mm is better.
Evaluation of Compaction Characteristics and Performance of Warm–Recycled Mix Asphalt
Authors: Xu Shi Fa , Luo Xiao Hui , Ji Jie , Li Zhen
Published: April 2011

Warm-Recycled Mix Asphalt (WRMA) is a new type mixture that can not only reduces the mixing temperature and exhausting gas emissions but also includes some waste materials (Reclaimed Asphalt Pavement, RAP).The compaction characteristics of WRMA were tested, while the compaction temperatures were 140°C, 130°C, 120°C, 110°C, 100°C and the RAP contents were 0%, 15%, 30%, 45%, and 60%, respectively. The compaction temperature for each WRMA was recommended according to the test results. Furthermore, this paper also evaluated the performances of each WRMA.
Damage Evolution of Reactive Powder Concrete by Low Velocity Impact
Authors: Zhao Qing Xin , Zhang Jin Rui , Liu Zhao Yang , Zhao Ran Ran
Published: April 2011

By means of the three-point bending impact equipment, with the measurement of ultrasonic velocity, the low velocity impact damage evolution of reactive powder concrete (RPC) with 0, 1%, 2% and 3% volume fraction of steel fiber were tested. In this study, the damage variable D pertaining to ultrasonic velocity had been selected to study the damage evolution process of RPC. The results indicate that the fatigue damage process of RPC is linear. The addition of fibers effectively improves the impact energy absorption behavior of RPC matrix, and the damage variable D of RPC with different fiber dosages increases by 1.1~3.5 times than that of plain concrete when it is ultimately destroyed.
Effect of Steam Curing on Water Sorptivity of Concrete
Authors: He Zhi Min , Liu Jun Zhe
Published: April 2011

This paper carried out experiments to investigate the change of water absorption gradient of standard curing concretes and steam-cured concretes cured at 60°C. The effect of steam curing on concretes water absorption was evaluated, and the corresponding mechanism was also discussed. Results indicate that the change of water absorption gradient of standard curing concretes is non-significant with the change of the specimen height; Steam curing has exacerbated the inhomogeneity between the top surface and interior surface of concretes. It is observed that noticeable gradient difference in aborption characteristics between top, the second (1cm below top surface) and the third (3cm below top surface) surfaces of samples. Top surface absorption capacity has been the highest, and the second surfaces are in rather good accordance with the third surface. Thus the effect depth of steam curing is near to the concrete open surface. The addition of silica fume to a concrete decrease the water sorptivity of steam curing and standard curing concretes, but for the improvement of the uniformity of concrete, the effect is not markedly obvious.
Investigation of Drying Shrinkage of Concrete Prepared with Iron Mine Tailings
Authors: Feng Xiao Xin , Xi Xue Li , Cai Ji Wei , Chai Hong Jun , Song Yu Zeng
Published: April 2011

Concretes of C30 and C60 were prepared with iron mine tailings as fine aggregate and coarse aggregate and with natural sand and common crushed stone separately. The drying shrinkage of concretes cured under the natural condition in the laboratory was tested. The results showed that whether C30 or C60 the drying shrinkage of concrete prepared with iron mine tailings was a little smaller than that of concrete with natural sand and common crushed stone. It was also found that whether the concrete with iron mine tailings or the concrete with natural sand and common crushed stone the drying shrinkage of C60 concrete was larger than that of C30 concrete.
Construction Process Simulation Analysis for High-Rise Steel Frame Concrete Core-Tube Structure
Authors: Ye Quan Xi , Zhang Yan Xia , Li Yun Peng
Published: April 2011

Construction process simulation analysis for high-rise steel frame concrete core-wall structure is conducted by using ABAQUS .The influences of construction process on axial force of bottom column and vertical differential deformation are discussed , some useful conclusions are obtained and reasonable references are provided for the structure design and construction .
A.C Impedance Spectrum and Microstructure of Reactive Powder Cementitious Materials with Low w/b
Authors: Long Guang Cheng , Ma Kun Lin , Xie You Jun
Published: April 2011

In order to understand microstructure characteristics and properties of reactive powder cementitious materials with low w/b, the A.C impedance test on reactive powder cementitious materials is carried out. The correlation between the impedance parameters, microstructure and properties of reactive powder cementitious materials is also analyzed. Results indicate that the impedance-frequency curve both for reactive powder mortar and ordinary cement mortar consists of vertical part in range of low frequency section and horizontal part within high frequency section. But the angle between vertical part and horizontal part of curve for reactive powder mortar is larger compared with ordinary specimen. There is a good linear relationship between the real part of impedance and angular frequency ω-1/2 for mortar when frequency is from 10Hz to 100Hz. And the slope φ of line increases with the additions of reactive powder and the lowering w/b. The mechanical strength and microstructure of reactive powder cementitious materials with low w/b can be expressed well by the A.C impedance characteristic parameters.
Improvement of the Corrosion Resistance for the Galvanic Coupling of Steel with Polypyrrole Coated Galvanized Steel
Authors: El-Shazly A.H. , Al-Turaif H.A.
Published: April 2011

The aim of the present work is to use intrinsically conducting polymers (ICPs) to improve the corrosion resistance ability of the galvanic coupling of galvanized steel coupled with steel by coating it with polypyrrole (PPy). The potentiostatic technique was used for forming the PPy layer using a potentiostat (EG&G A-273 Potentiostat/Galvanostat). Many variables were investigated for their effect on the characteristics of the formed coat layer such as: applied potential, electrolyte concentration (sodium tartrate concentration), solution pH, and type of electrode. The formed coat layer was investigated using X-Ray Photoelectron Spectroscopy (XPS) technique. Finally, the corrosion resistance ability of the galvanic coupling of PPy coated galvanized steel coupled with bare steel was investigated using electrochemical methods such as Tafel method. The results show that the galvanic coupling of PPy coated galvanized steel and bare steel has a corrosion current which is 31.8% less than the galvanic coupling of bare galvanized when coupled with steel.
Simultaneously Synthesis and Encapsulation of Metallic Nanoparticles Using Linear–Dendritic Block Copolymers of Poly(ethylene glycol)-Poly(citric acid)
Authors: Tavakoli Naeini Ashkan , Vossoughi Manouchehr , Adeli Mohsen
Published: April 2011

Linear-dendritic triblock copolymers of linear poly(ethylene glycol) and hyperbranched poly(citric acid) (PCA-PEG-PCA) were used as the reducing and capping agents to encapsulate gold and silver nanoparticles (AuNPs and AgNPs). PCA-PEG-PCA copolymers in four different molecular weights were synthesized using 2, 5, 10 and 20 citric acid/PEG molar ratios and were called A1, A2, A3 and A4, respectively. Nanoparticles were encapsulated simultaneously during the preparation process. AuNPs were simply synthesized and encapsulated by addition a boiling aqueous solution of HAuCl4 to aqueous solutions of A1, A2, A3 and A4. In the case of silver, an aqueous solution of AgNO3 was reduced using NaBH4 and AgNPs were encapsulated simultaneously by adding aqueous solutions of different PCA-PEG-PCA to protect the fabricated silver nanoparticles from aggregation. Encapsulated AuNPs and AgNPs were stable in water for several months and agglomeration did not occur. The synthesized silver and gold nanoparticles have been encapsulated within PCA-PEG-PCA macromolecules and have been studied using Transmission Electron Microscopy (TEM) and UV/Vis absorption spectroscopy. Studies reveal that there was a reverse relation between the size of synthesized AuNPs/AgNPs and the size of citric acid parts of PCA-PEG-PCA copolymers. For example, the prepared gold and silver nanoparticles by A3 copolymer are of an average size of 8 nm and 16 nm respectively. Finally, the loading capacity of A1, A2, A3 and A4 and the size of synthesized AuNPs and AgNPs were investigated using UV/Vis data and the corresponding calibration curve. It was found that the loading capacity of copolymers depends directly on the concentration of copolymers and their molecular weight.
Free Vibration Characteristics of Thermally Loaded Rectangular Plates
Authors: Jeon Byoung Hee , Kang Hui Won , Lee Young Shin
Published: April 2011

This paper reports on experimental and finite element analysis of the free vibration analysis of three rectangular plates under thermal load. The materials of the three rectangular plates were steel, aluminum and stainless-steel, respectively. The dimension of the plate was 0.1 x 0.1 x 0.002 m. Halogen lamps were used for thermal loading. A PCS (Power Control System) electric control system and a scanning vibrometer (Poly Tech) for frequency response function’s (FRF’s) acquisition were used. The applied temperature conditions were from room temperature to 300oC in 50oC steps. The boundary condition was a free-free condition using bungee cord and one entire side of the plate was heated. ABAQUS was used for FEM analysis. At first, the heat transfer analysis was conducted for each temperature condition and the modal analysis afterwards. The FEM model was verified by comparing experiment and FEM analysis. The FEM model for the modal analysis of thermally loaded plates could be verified.
Structure-Property Relationship of Burn Collagen Reinforcing Musculo-Skeletal Tissues
Authors: Yeo Yan Ling , Goh Kheng Lim , Kin Liao , Wang Hui Juan , Listrat Anne , Bechet Daniel
Published: April 2011

An investigation has been conducted on burn ligaments, addressing the specific conditions in burn arising from dehydration and heating, and how these affect the structure-property relationship of collagen for reinforcing the tissue. Collagen fibres were isolated from a sheep’s anterior cruciate ligament, i.e. our model for this study, and divided into six groups. The first group was designated as control; the second (D) group was dehydrated without exposure to elevated temperature. The remaining (DH) groups were dehydrated followed by heating at 120oC for 30 minutes, 2, 4 and 24 hours, respectively. Tensile test to rupture was carried out to derive the fibre modulus of elasticity (E), maximum stress (σ), strain at maximum stress (ε) and strain energy density to maximum stress (u). Electron micrographs of the ruptured ends reveal a mixed mode of fibril pull-out and rupture: fibril pull-out dominates in the control group but fibril rupture dominates increasingly in the other groups, i.e. with increasing exposure time to elevated temperature. Apart from ε, there is significant increase in E, σ and u in the D and DH groups with respect to the control group but there is no evidence of variation among the D and DH groups. The results of this study implicate (1) the removal of water in the hydrated proteoglycan-rich matrix, leading to shrinkages at micrometer length-scale during dehydration, and (2) the alteration of the collagen organisation arising from the underlying changes in the crystallinity and denaturation during heating, on the mechanical properties of burn collagen fibres.
A New Ternary Phase, Called LaCuMg8, for Solid Hydrogen Storage. Influence of Ball Milling and Cold Rolling
Authors: Boidin R. , Couillaud S. , Gaudin Etienne , Huot Jacques , Bobet Jean Louis
Published: April 2011

Recently, our group found a new phase with a composition close to LaCuMg8. This compound crystallizes in the La2Mg17 structure type. A similar hydrogen sorption behavior was observed for both La2Mg17 and LaCuMg8 compounds with a two steps mechanism. During the first step, LaCuMg8 absorbs around 3wt% with a low kinetic; the decomposition into LaH3, MgH2 and Cu2Mg is also observed. This first step is considered as the activation process. The second step consists in the reversible desorption/absorption of hydrogen by magnesium and also the reversible transformation of Mg2Cu into MgCu2. In order to improve the activation process, the influence of ball milling and cold rolling was tested. LaCuMg8 can not be synthesized by ball milling starting from elemental powders (LaCu + 8Mg). However, cold rolling on as-cast LaCuMg8 compound improves the activation. Indeed, more than 3%wt is absorbed after 1 hour which is 20 times faster than LaCuMg8 as cast. An effect of CuMg2, induced by cold rolling was proposed.
Magnetic Properties of the Gd1-xTbxNi3 Intermetallic Compounds
Authors: Bajorek Anna , Chełkowska Grażyna , Chrobak Artur , Kwiecień-Grudziecka Marzena
Published: April 2011

The paper presents selected magnetic properties of the Gd1-xTbxNi3 intermetallic compounds. Based on the wide-ranging SQUID magnetometer (Quantum Design MPMS, temperature from 1.9K to 300K and magnetic field up to 7T) series of different magnetic measurements were carried out. In studied system the saturation magnetization and the Curie temperature strongly depends of Tb concentration. Moreover, the so-called field cooling - zero field cooling (FC-ZFC) curves reveal a dependence of M(T) on the applied magnetic field. The thermomagnetic curves indicate interesting behaviour which is typical for terbium compounds and can be ascribed to the interaction between different aligned magnetic subblattices.
Some Aspects of the Intercalation Chemistry of the Niobium and Tantalum Carbide Chalcogenides Nb2S2S, Ta2S2C and Ta2Se2C
Authors: Boller Herbert
Published: April 2011

It is shown that metastable 1T-Nb2S2C can act as a host lattice for intercalation by soft chemical methods similar to isotypic Ta2S2C. The hydrated intercalation compounds Mx(H2O) y[Nb2S2C] (M…Na, K) are prepared by ion exchange in Cux[Nb2S2C] using NaCN or KCN or by reductive intercalation into the host lattices T2S2C at pH~10 using dithionite as reducing agent. The intercalation phases are characterized by TGA and X-ray powder diffraction. Nax(H2O)y[Nb2S2C] and Nax(H2O)y[Ta2S2C] have an expanded 1T-type with two layers of co-intercalated water while in Kx(H2O)y[Nb2S2C] only one layer of water is held by the less hydrated potassium ions. Kx(H2O)y[Nb2S2C] has a 3R(Ib)-type stacking. The intercalation phases are not very stable, especially Nax(H2O)y[Nb2S2C] and Nax(H2O)y[Ta2S2C] are very quickly deintercalated by oxidation. After deintercalation colloidal suspensions are formed. Ethylene diamine is spontaneously intercalated into Nb2S2C and Ta2S2C. Nb2S2C.enx has a 3R(Ib)-type stacking similar to that of Kx(H2O)y[Nb2S2C]. Ta2Se2C is isotypic to 1T- Ta2S2C (P m1, a = 3.313(1) Å, c = 8.968(2)Å, Z = 1). Ta2Se2C does not form intercalation phases under soft chemical conditions.
Mössbauer and Magnetization Measurements of Al3Mn(Pd,Fe) Compounds
Authors: Ali Kamran , Reissner Michael , Feuerbacher Michael , Steiner Walter
Published: April 2011

Magnetic and 57Fe Mössbauer measurements are reported on Taylor-phase compounds T-Al3Mn(Pd,Fe), which are complex metallic alloys containing 156 atoms in the unit cell. These investigations are extended to Al71Mn19Fe10 which crystallize as decagonal quasicrystal. Common for all samples spin glass behavior is present at low temperatures with freezing temperatures Tf increasing (decreasing) with Fe (Pd) content. Below Tf rejuvenation and memory effects are observed in aging investigations. Above Tf the 57Fe Mössbauer spectra were analysed by a superposition of two subspectra with intensity ratio around 75:25, which might be allocated to Fe substituted on Mn sites surrounded either by Al and Mn or completely by Al in the nearest neighborhood. Below Tf broad hyperfine field distributions are present.
Thermal Expansion of Oxyarsenides (LaO)TAs; T = Transition Metal
Authors: Otsuka Shintaro , Onizawa Manami , Kato Koma , Hiramoto Shozo , Yoshida Fumiko , Moriyoshi Chikako , Watanabe Tadataka , Takano Yoshiki , Kuroiwa Yoshihiro , Takase Kouichi
Published: April 2011

We have investigated the precise crystal structure and their temperature dependences of oxyarsenides (LaO)TAs; T = Mn, Fe, Co, as the Fe based superconductor’s parent material family using high energy synchrotron radiation x-ray powder diffraction. Lattice constants a and c decrease with decreasing temperature. Focusing the ratios of the changes normalized by room temperature lattice constants, we have found anisotropic shrinks for the superconductor’s parent material of (LaO)FeAs and the ferromagnetic metal (LaO)CoAs. The shrinkage of the lattice constant c along the stacking direction will be discussed by the temperature dependence of the divided three components of the LaO layer, TAs layer, and the interlayer distance.
Mössbauer Spectroscopic Analysis of Nd2Fe14B/α-Fe Hard Magnetic Nanocomposites
Authors: Cekić Bozidar , Ivanovski Valentin , Codescu Mirela Maria , Umićević Ana , Barudzija Tanja , Pătroi Eros Alexandru
Published: April 2011

Among novel magnetic intermetallics based on rare earth-transition compounds, the Nd2Fe14B/α-Fe isotropic nanocomposites have been obtained by recrystallization from an amorphous phase, prepared by melt spinning. For variable 5 wt.% Fe and 10 wt.% Fe contents we recorded transmission 57Fe Mössbauer spectra at the room temperature, hardened of the α-Fe phase by exchange interactions. The spectra have been analyzed in terms of ten Zeeman sextets and one paramagnetic doublet related to the Nd1.1Fe4B4 phase. One sextet corresponds to the α-Fe phase, whereas others are attributed to six non-equivalent Fe sites in the Nd2Fe14B structure, namely 16k1, 16k2, 8j1, 8j2, 4c, and 4e. The three remaining sextets belong to the Fe3B structure with three inequivalent Fe sites FeI(8g), FeII(8g) and FeIII(8g). All relevant parameters for both nanocomposites: the magnetic hyperfine field, the isomer shift and the quadrupole splitting are determined for each of these sites.
The Pyrrhotite 32 K Magnetic Transition
Authors: Wolfers Pierre , Fillion Gerard , Ouladdiaf B. , Ballou Rafik , Rochette P.
Published: April 2011

Pyrrhotite [1] is a common ferrimagnetic mineral in terrestrial rocks and has been identified recently as the major remanence carrier in Martian rocks, as in SNC (Shergotty-Nakhla-Chassigny) type meteorites. This compound undergoes a low temperature magnetic transition around 32 K with a change in the natural magnetic remanence [2]. This transition is going to be of growing importance in paleomagnetism and rock magnetism. To determine the structure change at 32K neutron diffraction was performed on two crystal samples at 50K and 20K (D10-ILL). Based on the magnetic torque measurements, performed on the same samples, a model of low-temperature triclinic structure was build. This model, explains previous Mössbauer experiments [4], the torque measurements, the magneto-crystalline anisotropy decreasing.
Optical Characterization of Electronic Structure of CuInS2 and CuAlS2 Chalcopyrite Crystals
Authors: Ho Ching Hwa , Lo Sheng Feng , Chi Ping Chen , Wu Ching Cherng , Huang Ying Sheng , Tiong Kwong Kau
Published: April 2011

Electronic structure of solar-energy related crystals of CuInS2 and CuAlS2 has been characterized using thermoreflectance (TR) measurement in the energy range between 1.25 and 6 eV. The TR measurements were carried out at room (~300 K, RT) and low (~30 K, LT) temperatures. A lot of interband transition features including band-edge excitons and higher-lying interband transitions were simultaneously detected in the low-temperature TR spectra of CuInS2 and CuAlS2. The energies of band-edge excitonic transitions at LT (RT) were analysed and determined to be =1.545 (1.535) and =1.554 eV (1.545 eV) for CuInS2, and =3.514 (3.486), =3.549 (3.522), and =3.666 eV (3.64 eV) for CuAlS2, respectively. The band-edge transitions of the and excitons are originated from the sulfur pp transitions in CuInS2 and CuAlS2 separated by crystal-field splitting. Several high-lying interband transitions were detected in the TR spectra of CuInS2 and CuAlS2 at LT and RT. Transition origins for the high-lying interband transitions are evaluated. The dependence of electronic band structure in between the CuInS2 and CuAlS2 is analysed and discussed.
Influence of Temperature Independent Contribution of Magnetic Susceptibility on the Curie-Weiss Law
Authors: Groń Tadeusz , Pacyna Andrzej W. , Malicka E.
Published: April 2011

A fitting procedure of the Curie-Weiss law, eliminating the temperature independent contribution (0) from the experimental susceptibility data, was used for determination of the magnetic parameters, i.e. a Curie constant, a Curie-Weiss temperature and an effective magnetic moment, because the theoretical considerations showed that the Curie-Weiss law is invalid for 0  0, even small. This method revealed for the HgCo(NCS)4 paramagnet, commonly accepted as a magnetic susceptibility standard, 0 = 2.43710-6 cm3/g, while for the ZnCr2Se4 antiferromagnet, known as a matrix of various diluted systems, – 0 = -2.56610-6 cm3/g, for comparison.
Half a Century of Nanoantiferromagnetism: Richardson’s Phenomenon and Néel’s Models
Authors: Petrik Marek , Harbrecht Bernd
Published: April 2011

It is pointed out that the most important open question posed by the anomalous uncompensated magnetic moment of nanosized antiferromagnets is largely overlooked today, 54 years after Richardson’s discovery of the phenomenon and 49 years after Néel’s explanation of it.
Structure and Magnetism of a Novel Nickel Sulfate Ni2-δSO5
Authors: Takahashi Misaki , Hara Shigeo , Sato Hirohiko
Published: April 2011

We succeeded in synthesizing single crystals of a novel nickel sulfate Ni2-δSO5 by a hydrothermal method. A single-crystal X-ray diffraction revealed a tetragonal structure with lattice constants, a = 5.184 Å and c = 12.91 Å. In this structure, one-dimensional chains composed of face-shared NiO6 octahedra elongate along the a axis and the b axis alternately, constructing a ‘log-cabin’ type framework where neighbor chains lying orthogonally to each other are connected by SO4 tetrahedra. A detailed refinement of the structure suggested that the site occupancy of Ni is only 63%, corresponding to δ ≈ 2/3. Furthermore, X-ray oscillation photographs exhibit diffuse-scattering patterns probably arising from a short-range order of the Ni defects. Magnetic susceptibility revealed an antiferromagnetic transition accompanied by a weak ferromagnetism at 17 K.
High-Yield Direct Synthesis of Mg2FeH6 from the Elements by Reactive Milling
Authors: Leiva Daniel Rodrigo , De Souza Villela André Castro , Paiva-Santos Carlos de Oliveira , Fruchart Daniel , Miraglia Salvatore , Ishikawa Tomaz Toshimi , Botta Filho Walter José
Published: April 2011

Magnesium complex hydrides as Mg2FeH6 are interesting phases for hydrogen storage in the solid state, mainly due to its high gravimetric and volumetric densities of H2. However, the synthesis of this hydride is not trivial because the intermetallic phase Mg2Fe does not exist and Mg and Fe are virtually immiscible under equilibrium conditions. In this study, we have systematically studied the influence of the most important processing parameters in reactive milling under hydrogen (RM) for Mg2FeH6 synthesis: milling time, ball-to-powder weight ratio (BPR), hydrogen pressure and type of mill. Low cost 2Mg-Fe mixtures were used as raw materials. An important control of the Mg2FeH6 direct synthesis by RM was attained. In optimized combinations of the processing parameters, very high proportions of the complex hydride could be obtained.
Synthesis of Novel Chromium Oxide Using Hydrothermal Method and Analysis of its Magnetism and Structure
Authors: Ogawa Shintaro , Okuta Koji , Sato Hirohiko
Published: April 2011

We have discovered a novel compound Na0.12CrO2Ge0.18Ox•yH2O using a hydrothermal method. Its powder X-ray diffraction reveals a monoclinic unit cell with lattice parameters: a = 7.260 Å, b = 2.950 Å, c = 5.117 Å and β = 103.7°. A Rietveld analysis shows that this compound has a layered structure based on CrO2 sheets consisting of edge-shared CrO6 octahedra. Such a layered structure is commonly seen in many hexagonal Cr oxides such as NaCrO2. A heat treatment at 100 °C modifies the crystal structure without destruction of a layered structure based on Cr triangular-lattice, because H2O molecules among the CrO2 sheets are removed at high temperature. Magnetization measurements reveal a spin-glass behavior below Tg = 3 K.
Modelling of Mg/Ti and Mg/Nb Thin Films for Hydrogen Storage
Authors: Klyukin Konstantin , Shelyapina Marina G. , Fruchart Daniel
Published: April 2011

Mg/TM thin films are objects of interest as hydrogen storage materials due to their expected interesting thermodynamic and hydrogen sorption kinetic properties. Here we report on the results of ab initio calculation on the stability of Mgn/Ti and Mgn/Nbm thin films.
Phase Transformations in Ti-V-Cr-H Composition
Authors: Skryabina N.E. , Fruchart Daniel , Miraglia Salvatore , de Rango Patricia , Shelyapina Marina G.
Published: April 2011

Occurrence of phase transitions in TixVyCrz-H systems was analyzed versus temperature. Hydrogen evacuates from the hydrogenated compounds via two main steps. The 1st step corresponds to the destabilization of the fcc hydrogenated lattice leading to a fcc → bcc martensitic type transformation. The 2nd step occurs according to the decomposition of the resulting hydride via evacuation of hydrogen from the bcc lattice. Both the kinetics and temperature of 1st and 2nd step transformations depend on the composition of the starting TixVyCrz alloys.
Deposition and Characterization of IrO2 Nanocrystals on Vertically Aligned Carbon Nanotubes by MOCVD
Authors: Chen Yi Min , Huang Ying Sheng , Lee Kuei Yi , Tiong Kwong Kau
Published: April 2011

IrO2 nanocrystals (NCs) were grown on vertically aligned carbon nanotubes (CNTs) forming IrO2/CNTs nanocomposites by metal organic chemical vapor deposition using (C6H7)(C8H12)Ir as a source reagent. The surface morphology, structural and spectroscopic properties of the nanocomposites were characterized. Micrographs of field-emission scanning electron microscope showed that the surface morphology of the as-deposited IrO2 NCs varied from particle-like to tube-like NCs as the deposition time increased from 5 to 60 min. The transmission electron microscope image of IrO2/CNTs nanocomposites revealed that IrO2 NCs had been deposited onto the surface of the CNTs with uniform size distribution and random directions. X-ray diffraction pattern confirmed the formation of pure rutile IrO2 NCs on CNTs. The redshifts of the peak positions and broadening of linewidths of the IrO2 Raman features were attributed mainly to the size effect. The particles-like IrO2 NCs may be used as a protective layer on CNTs, providing stable and uniform field emission application. While the nanotube-like structure may increase the surface-to-volume ratio which makes the IrO2/CNTs nanocomposites as an attractive candidate for the supercapacitor application.
Painful Pathways Induced by TLR Stimulation of Dorsal Root Ganglion Neurons
Authors: Qi Jia , Buzas Krisztina , Fan Huiting , Cohen Jeffrey I. , Wang Kening , Mont Erik , Klinman Dennis , Oppenheim Joost J. , Howard O. M. Zack
Published: April 2011

We hypothesize that innate immune signals from infectious organisms and/or injured tissues may activate peripheral neuronal pain signals. In this study, we demonstrated that TLRs 3, 7, and 9 are expressed by human dorsal root ganglion neurons (DRGNs) and in cultures of primary mouse DRGNs. Stimulation of murine DRGNs with TLR ligands induced expression and production of proinflammatory chemokines and cytokines CCL5 (RANTES), CXCL10 (IP-10), IL-1α, IL-1β, and PGE2, which have previously been shown to augment pain. Further, TLR ligands upregulated the expression of a nociceptive receptor, transient receptor potential vanilloid type 1 (TRPV1), and enhanced calcium flux by TRPV1-expressing DRGNs. Using a tumor-induced temperature sensitivity model, we showed that in vivo administration of a TLR9 antagonist, known as a suppressive oligodeoxynucleotide, blocked tumor-induced temperature sensitivity. Taken together, these data indicate that stimulation of peripheral neurons by TLR ligands can induce nerve pain.
Human Dendritic Cell Subsets from Spleen and Blood Are Similar in Phenotype and Function but Modified by Donor Health Status
Authors: Mittag Diana , Proietto Anna I. , Loudovaris Thomas , Mannering Stuart I. , Vremec David , Shortman Ken , Wu Li , Harrison Leonard C.
Published: April 2011

Mouse dendritic cells (DC) have been extensively studied in various tissues, especially spleen, and they comprise subsets with distinct developmental origins, surface phenotypes, and functions. Considerably less is known about human DC due to their rarity in blood and inaccessibility of other human tissues. The study of DC in human blood has revealed four subsets distinct in phenotype and function. In this study, we describe four equivalent DC subsets in human spleen obtained from deceased organ donors. We identify three conventional DC subsets characterized by surface expression of CD1b/c, CD141, and CD16, and one plasmacytoid DC subset characterized by CD304 expression. Human DC subsets in spleen were very similar to those in human blood with respect to surface phenotype, TLR and transcription factor expression, capacity to stimulate T cells, cytokine secretion, and cross-presentation of exogenous Ag. However, organ donor health status, in particular treatment with corticosteroid methylprednisolone and brain death, may affect DC phenotype and function. DC T cell stimulatory capacity was reduced but DC were qualitatively unchanged in methylprednisolone-treated deceased organ donor spleen compared with healthy donor blood. Overall, our findings indicate that human blood DC closely resemble human spleen DC. Furthermore, we confirm parallels between human and mouse DC subsets in phenotype and function, but also identify differences in transcription factor and TLR expression as well as functional properties. In particular, the hallmark functions of mouse CD8α+ DC subsets, that is, IL-12p70 secretion and cross-presentation, are not confined to the equivalent human CD141+ DC but are shared by CD1b/c+ and CD16+ DC subsets.
Benign Lesions in Mucosa Adjacent to Intestinal-Type Sinonasal Adenocarcinoma
Authors: Vivanco Blanca , Llorente José Luis , Perez-Escuredo Jhudit , Álvarez Marcos César , Fresno Manuel Florentino , Hermsen Mario A.
Published: April 2011

Occupational exposure to wood dust is a strong risk factor for the development of intestinal-type sinonasal adenocarcinoma (ITAC); however, knowledge on possible precursor lesions or biomarkers is limited. Fifty-one samples of tumor-adjacent mucosa and 19 control samples of mucosa from the unaffected fossa of ITAC patients were evaluated for histological changes and p53 protein expression. Mild dysplasia was observed in 14%, cuboidal metaplasia in 57%, intestinal metaplasia in 8%, squamous metaplasia in 24%, and cylindrocellular hyperplasia in 53% of cases. P53 immunopositivity was generally weak occurring most frequently in squamous metaplasia. Wood dust etiology did not appear of influence on the histological changes, but p53 showed a tendency for higher positivity. Dysplasia adjacent to tumor was indicative of subsequent development of recurrence. In conclusion, precursor lesions do occur in mucosa adjacent to ITAC. This is clinically important, because it may justify the screening of high-risk individuals such as woodworkers.
Acute Promyelocytic Leukemia, Hypogranular Variant: A Rare Presentation
Authors: Akhtar Kafil , Ahmad Shamshad , Sherwani Rana K.
Published: April 2011

Early diagnosis of acute promyelocytic leukemia (APL) is essential because of its associated life threatening coagulopathy and unique response to all trans-retinoic acid (ATRA) therapy. The characteristic cell morphology supplemented by cytochemistry offers the most rapid means for diagnosis. Here we describe a rare case of acute promyelocytic leukemia-hypogranular variant that poses particular diagnostic challenge.
Cholestatic Hepatitis due to Salmonella typhi
Authors: Albayrak Ayse , Gunbey Sibel Seda , Aktas Ferda
Published: April 2011

Salmonella infection occurs worldwide and is still an important public health problem in many developing countries. The infection can affect almost all major organs including the liver. Severe hepatic involvement with a clinical feature of acute hepatitis is a rare complication. In this paper, a 39-year-old male with acute cholestatic typhoid hepatitis is presented. The case had a tender hepatomegaly and elevated serum alanine and aspartate transaminase, alkaline phosphatase, and gamma glutamyl transferase levels; these features cannot been distinguished from those of acute viral hepatitis. Serological and viral markers of acute viral hepatitis were negative. No pathology could be determined in abdomen Ultrasonography (USG) or Magnetic Reso - nance (MR) Cholangiography. As enteric fever is a common infection, the recognition of salmonella hepatitis is of clinical importance. When patients from an endemic or outbreak area present acute febrile hepatitis, typhoid fever should be a consideration.
Peritoneal Carcinomatosis Mimicking a Perforated Diverticulitis
Authors: Facy Olivier , Lagoutte Nicolas , Paquette Brice , Rat Patrick , Ortega Deballon Pablo
Published: April 2011

We report the case of a patient with a pelvic abscess and a malignant pancreatic tumor. The management of this complicated diverticulitis included radiological drainage and surgery. This abscess was due to a peritoneal carcinomatosis originating from the pancreas, which is an extremely rare cause of intestinal perforation.
Supratherapeutic International Normalized Ratio: An Indicator of Chronic Malnutrition Due to Severely Debilitating Gastrointestinal Disease
Authors: Kumar Sarwan , Gupta Deepak , Rau Shiva S.
Published: April 2011

This case highlights the fact that Supratherapeutic INRs direct the attention of the treating physicians’ team to the underlying severely debilitating gastrointestinal diseases. Prolonged fasting or starvation reduces vitamin K levels. Such patients are more sensitive to treatment with Vitamin K antagonist-based anticoagulants. Hence, the Supratherapeutic INR can be an objective indicator of chronic loss of appetite with poor nutritional status of the patient and therefore acts as a warning sign for diagnosis of severe debilitating primary gastrointestinal disease.
Endoscopic ultrasound-guided fine-needle aspiration of metastases to the pancreas: A study of 25 cases
Authors: Gilbert Christopher M. , Monaco Sara E. , Cooper Scott T. , Khalbuss Walid E.
Published: April 2011

Background:

Metastases to the pancreas are an uncommon cause of pancreatic masses seen on endoscopic ultrasound (EUS)-guided fine-needle aspiration (FNA). The purpose of this study is to retrospectively review the cytomorphology, clinical findings, and results of ancillary studies in a large series of these unusual cases.

Materials and Methods:

We searched our institution's pathology database for EUS-guided FNAs of the pancreas that were diagnostic of metastatic tumor over a 5-year period. The final cytologic diagnosis, results of ancillary studies, corresponding histological material, and clinical follow-up data were reviewed in these cases.

Results:

A total of 1172 pancreatic EUS-guided FNAs were identified, of which 25 cases (2.1%) had a confirmed diagnosis of a pancreatic metastasis. This included 12 (48%) cases of renal cell carcinoma, 3 (12%) melanomas, 3 (12%) small cell carcinomas, and 7 (28%) other malignancies. In these metastatic tumors involving the pancreas, 20 (80%) of the lesions were solitary. Four (16%) cases had no prior history of malignancy. The average time to diagnosis of pancreatic metastasis was 5.3 years. Immunohistochemistry and special stains were performed in 22 (88%) and 9 (36%) cases, respectively.

Conclusions:

Our data shows that although metastases to the pancreas are rare, they can present as a solitary mass many years after the primary malignancy is diagnosed and can even be the first manifestation of an extrapancreatic primary in a small number of cases. It is important to consider the possibility of a metastatic lesion in the pancreas because this may require a different management than a primary pancreatic tumor.
Successive measurements of carcass fat and loin muscle depths at the same site with optical probes
Authors: Pomar C. , Fortin A. , Marcoux M.
Published: April 2011

The effect of successive measurements at the same site studied on 286 pork carcasses with three optical grading probes was small but different between probes. This effect was inefficiently corrected by regression. It is recommended that successive measurements be taken on immobilized carcasses and that balance be maintained in the order of probe use. Key words: Pork, backfat, muscle depth, successive probing
An investigation into the anatomical differences between flat and folded leaves in reed canarygrass (Phalaris arundinacea L.)
Authors: Wrobel Chris , Coulman B. E. , Smith D. L.
Published: April 2011

Reed canarygrass, Phalaris arundinacea L., is one of the most productive, perennial cool-season grasses. It is found in humid and subhumid regions of the northern United States and southern Canada. Reed canarygrass plants with folded leaves were observed in a space-planted nursery. Morphological variants involving leaf folding or rolling have been studied in a number of grass species. None of these studies have investigated the anatomical differences between the folded leaf and more frequently occurring flat leaves in the respective species. The objective of this study was to investigate the histological differences between the folded and flat leaves. Upon sectioning, the flat leaf type was observed to have turgid bulliform cells, while those in the folded leaves were flaccid. And the folded leaves appeared to have a larger sclerenchymal layer in the extended bundle sheaths compared with the flat leaves. Incorporating the folded leaf genotype into a breeding program may allow the cultivation of reed canarygrass in more arid regions, and may improve the biofuel quality of a resulting cultivar. Key words: Leaf morphology, anatomy, plant breeding, cool-season grass, folded leaf
Long-term effect of placement of fertilizer nitrogen and phosphorus on barley yields
Authors: Karamanos R. E. , Harapiak J. T. , Flore N. A.
Published: April 2011

An experiment that was established in 1990 to assess depth and method of placement of nitrogen (N) and phosphorus (P) fertilizer on the yield of continuous barley (with 1 yr interruption with canola in 1995) was continued to 2001. Annually, 80 kg N ha-1 were banded either at 7.5 to 10 or 15 to 17.5 cm depth alone or in combination with 40 kg P2O5 ha-1; the latter was either seedrow placed or banded with the N (dual banding), or split 1/2 in the seedrow and 1/2 in the band. An unfertilized control was maintained in all years. Temperature after seeding had a marked effect on the effectiveness of depth of N and P placement as well as the method of P placement. Shallow (7.5 to 10 cm depth) placement resulted in greater yields in 8 of the 11 yr that barley was grown and was never inferior to deeper placement (15 to 17.5 cm); this advantage was directly related to cooler-than-normal temperature after seeding. Cooler-than-normal temperatures also resulted in benefits from seedrow placed P; however, benefits were not as frequent as those obtained by either dual banding or splitting P between seedrow and the band. It would appear that overall benefits from banding P together with N (dual band), independently of the depth of banding, are greater than those from seedrow placing, as those benefits from the latter are less frequent and of considerably less magnitude. Key words: Band, dual band, seedrow, shallow, deep
Nature soybean
Authors: Poysa V. , Woodrow L. , Yu K.
Published: April 2011

Nature is a high-yielding, large-seeded tofu-type soybean [Glycine max (L.) Merr.] cultivar with elevated seed protein content developed at the Agriculture and Agri-Food Canada Research Centre, Harrow, Ontario. Nature is adapted to areas with 3150 or more crop heat units. Nature seeds have yellow hila and acceptable tofu processing quality for foreign and domestic markets. Key words: Glycine max (L.) Merr., soybean, cultivar description, tofu
Burning of alfalfa stubble for insect control as it affects soil chemical properties
Authors: Dormaar J. F. , Schaber B. D.
Published: April 2011

Southern Alberta growers often burn fields of seed alfalfa (Medicago sp.) prior to initiation of growth in the spring as a part of an Integrated Pest Management Programme. An 8-yr study compared the effects of (a) fall-burned every year, (b) spring-burned, prior to growth, every year, (c) spring-burned, prior to growth, every other year, and (d) zero burned, on various chemical properties of the upper 50 mm of soil. Burning led to highly significant increases in carbohydrates, total N, NO3-N, and extractable K over the 8 yr. Increases were also highly significant for NH4-N under the fall-burned every year regime. Spring-burning, prior to growth, every other year, led to the least accumulations of measured parameters. Although pest insects were controlled and pedigreed alfalfa seed production was increased under the various burn treatments examined within the conditions of the experiment, changes in certain soil chemical properties identified the need to monitor subsequent crop behavior once the alfalfa fields have been ploughed. Key words: Fire, prescribed burning, pest management, seed alfalfa
The relative persistence of trifluralin (545 EC and 5 G) and ethalfluralin in prairie soils
Authors: Gerwing Perry D. , McKercher Robert B.
Published: April 2011

The persistence in soil of trifluralin 545 EC, trifluralin 5 G, and ethalfluralin 360 EC was studied over a 2-yr period at three different sites in Saskatchewan. At two of the three sites both formulations of trifluralin were more persistent than ethalfluralin when a canola crop was grown in the treated soil. In the high organic matter soil at the third site the persistence of trifluralin and ethalfluralin was similar under both fallow and cropped conditions. Crop response data gathered from wheat, oat and millet stands plus gas chromatographic analysis of soil extracts indicated that trifluralin 545 EC and trifluralin 5 G persisted in soil for comparable lengths of time when applied at rates between 0.85 and 1.40 kg a.i. ha−1. At recommended application rates to summerfallowed fields, the amount of herbicide remaining in the different soils at seeding time the following season was least for ethalfluralin 360 EC. The average amount of trifluralin 545 EC, trifluralin 5 G and ethalfluralin 360 EC which remained in the soil at the three field locations the year following application was 13, 13 and 6%, respectively. Key words: Trifluralin, ethalfluralin, herbicide persistence
The development of assessment and remediation guidelines for contaminated soils, a review of the science
Authors: Sheppard S. C. , Sheppard M. I. , Gaudet C. , Cureton P. M. , Wong M. P.
Published: April 2011

Soil contamination is no longer restricted to isolated incidents and locations; it is a general and contentious problem. However, the problem is complex, starting with the very definition of what level and type of contamination is unacceptable. A myriad of regulatory and de facto guidelines have emerged, and they are extremely fragmented, inconsistent and incomplete. This review attempts to summarize the historical development of assessment and remediation guidelines, to highlight the unique difficulties of the problem, and then to discuss the scientific information that exists and that is needed to improve guidelines. There is an unlimited scope for research on this subject. Key words: Contaminant, cleanup, toxicity, pathways, risk, hazard assessment
Build-up in soil available P and yield response of spring wheat to seed-placed P in a 24-year study in the Brown Soil zone
Authors: Zentner R. P. , Campbell C. A. , Selles F.
Published: April 2011

Producers in western Canada have applied phosphorus (P) fertilizer to annual crops for many years. This has increased soil available P and gradually decreased the expected yield response to P fertilization, but yield responses to small amounts of P placed with the seed are still reported regardless of soil available P levels. Controlled growth chamber studies suggest that the P responses should be most apparent during cool, wet springs. This 24-yr field study compared the yields of two fallow–spring wheat–spring wheat (F–W–W) systems, one fertilized with N and P each crop year, and the other fertilized with only N. The study, which was part of a long-term crop rotation experiment, was conducted on an Orthic Brown Chernozemic loam at Swift Current, Saskatchewan. Bicarbonate-extractable P (Olsen P) in the 0- to 15-cm depth in spring of the treatment receiving no P remained relatively constant (about 19 kg ha−1) throughout the study, while P fertilizer application at 6.5 kg ha−1 yr−1 increased extractable soil P by about 0.9 kg ha−1 yr−1. However, this increase in available P has not reduced yield responses to seed-placed P over the years. Regression analysis showed that yield response to P on fallow soil was positively related to temperature between emergence and the three-leaf stage and to precipitation at dough stage, but negatively related to precipitation near seeding time. For wheat grown on stubble, response to P was negatively related to temperature between 10 and 16 June (i.e., about the three- to four-leaf stage) and positively to precipitation received at anthesis stage. We concluded that, although available P in prairie soils has probably increased in recent years, producers can still expect to receive a 10% yield increase when small amounts of P are applied with the seed.Key words: Crop rotations, bicarbonate-extractable P, Olsen P, temperature effects, effect of precipitation