bluuebunny/crossref_metadata_2025 huggingface dataset:
From TLS to VLS: Biomass Estimation at Individual Tree Level
Authors: Lin Yi , Jaakkola Anttoni , Hyyppä Juha , Kaartinen Harri
Published: July 2010

This study explores the applicability of vehicle-based laser scanning (VLS) for biomass estimation at individual tree level, since biomass serves as an essential biophysical parameter indicating tree health. Previous work suggests that terrestrial laser scanning (TLS) has been primarily validated for biomass prediction, however, in subject to laborious relocation in practice. VLS, as an advanced mode of TLS with more flexible mobility and also high sampling density, can work as a new efficient technique for surveying single trees. Combined with the positive binds between the biomass and TLS-samplings during manual defoliation, this work aims to seek the relations between biomass and VLS-samplings, by correlating the VLS- and TLS-samplings within the same crowns during natural foliation. The resulting R2 values of the two correlations after normalization are larger than 0.88 and 0.61, respectively, and the associated root mean square errors (RMSEs) are less than 0.051 and 0.076. VLS, thus, can be validated for estimating biomass at the individual tree level, with the TLS-investigated data as a bridging reference.
In Support of Canada’s Health Care System: An Oncologist’s Perspective
Authors: Zaidi Adnan Ali
Published: July 2010

The Canadian health care system is at [...]
Prophylaxis and Management of Acute Radiation-Induced Skin Reactions: A Systematic Review of the Literature
Authors: Salvo N. , Barnes E. , van Draanen J. , Stacey E. , Mitera G. , Breen D. , Giotis A. , Czarnota G. , Pang J. , De Angelis C.
Published: July 2010

Radiation therapy is a common treatment for cancer patients. One of the most common side effects of radiation is acute skin reaction (radiation dermatitis) that ranges from a mild rash to severe ulceration. Approximately 85% of patients treated with radiation therapy will experience a moderate-to-severe skin reaction. Acute radiation-induced skin reactions often lead to itching and pain, delays in treatment, and diminished aesthetic appearance—and subsequently to a decrease in quality of life. Surveys have demonstrated that a wide variety of topical, oral, and intravenous agents are used to prevent or to treat radiation-induced skin reactions. We conducted a literature review to identify trials that investigated products for the prophylaxis and management of acute radiation dermatitis. Thirty-nine studies met the pre-defined criteria, with thirty-three being categorized as prophylactic trials and six as management trials. For objective evaluation of skin reactions, the Radiation Therapy Oncology Group criteria and the U.S. National Cancer Institute Common Toxicity Criteria were the most commonly used tools (65% of the studies). Topical corticosteroid agents were found to significantly reduce the severity of skin reactions; however, the trials of corticosteroids evaluated various agents, and no clear indication about a preferred corticosteroid has emerged. Amifostine and oral enzymes were somewhat effective in preventing radiation-induced skin reactions in phase ii and phase iii trials respectively; further large randomized controlled trials should be undertaken to better investigate those products. Biafine cream (Ortho–McNeil Pharmaceuticals, Titusville, NJ, U.S.A.) was found not to be superior to standard regimes in the prevention of radiation-induced skin reactions (n = 6). In conclusion, the evidence is insufficient to support the use of a particular agent for the prevention and management of acute radiation-induced skin reactions. Future trials should focus on comparing agents and approaches that, in phase i and ii trials, suggest efficacy. These future phase iii randomized controlled trials must clearly distinguish between preventive and management strategies for radiation-induced dermatitis. Only then can evidence-based guidelines be developed, with the hope of standardizing the approach across centres and of improving the prevention and management of radiation-induced dermatitis.
Evaluating the Impact on Quality of Life of Chemoradiation in Gastric Cancer
Authors: Kassam Zahra , MacKay H. , Buckley C.A. , Fung S. , Pintile M. , Kim J. , Ringash J.
Published: July 2010

Objective: Our phase I study prospectively evaluated quality of life (QOL) in patients undergoing adjuvant chemoradiation for gastric adenocarcinoma. Methods: Thirty-three patients receiving radiotherapy (45 Gy in 25 fractions), together with 12 weeks of infusional 5-fluorouacil and escalating doses of cisplatin every 2 weeks, completed the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire C30 at five time points: baseline, completion of radiation, 4 weeks after completion of radiation, 6–12 months after completion of chemoradiation, and 2–3 years after completion of chemoradiation. Results: Mean age of the patients was 56 years (range: 31–77 years); 55% of the patients were male. Median followup was 2.7 years (range: 0.3–5 years). The 3-year overall survival was 83%. Five patients experienced dose-limiting toxicity (DLT). Median scores on global QOL and on the social, role, emotional, nausea and vomiting, and fatigue scales showed clinically and statistically significant worsening at completion of radiation. Statistical but not clinical worsening was found for the physical and appetite scales. By 6–12 months, no subscale showed a difference, on average, from the baseline score. However, up to 45% of the patients remained below baseline on at least 1 subscale. Patients with DLT had worse scores on the emotional and the nausea and vomiting scales. Scores for global QOL and for nausea and vomiting were significantly associated with chemotherapy dose. Conclusions: During chemoradiation, QOL is impaired. Although most scores return to baseline, recovery may take 6–12 months, and subscale scores remain below baseline in a significant proportion of patients.
Access to Thalidomide for the Treatment of Multiple Myeloma in Canada: Physician Behaviours and Ethical Implications
Authors: Minuk L. , Sibbald R. , Peng J. , Bejaimal S. , Chin-Yee I.
Published: July 2010

Background: Multiple myeloma is an incurable malignancy. Since the late 1990s, its management has changed with the introduction of novel agents. Thalidomide, which is often called a “novel” therapy, has significantly prolonged survival in multiple myeloma and is considered worldwide to be part of standard of care in this disease. However, thalidomide is not approved in Canada, leading to problems with drug access for patients. Methods: Our study surveyed Canadian hematologists on their thalidomide prescribing practices and difficulties with drug access. We address some of the ethical issues facing patients and their doctors who are unable to obtain or afford the drug, and who therefore resort to alternative means such as illegal importation. Results: Of the 411 Canadian hematologists contacted, 122 completed the survey, 97 reported that they did not treat myeloma, and 192 did not respond. Assuming that all non-responders treat myeloma, our estimated overall response rate from physicians who treat this disease was 39%. Survey participants indicated that, in Canada, access to thalidomide is a major issue for physicians and myeloma patients alike, and that 81% of respondents are dissatisfied or very dissatisfied with the drug access process. Many physicians felt that the special access process for thalidomide is unduly onerous, influences treatment decisions, and invades patient privacy. We found that 20% of physicians were unaware of the legal implications of obtaining thalidomide from other countries and that at least 23% overtly or covertly support patients in obtaining the drug from a non-Health-Canada-approved source. Conclusions: The current lack of access to thalidomide in Canada is a concerning problem for patients and health care providers dealing with myeloma. Regulatory changes at the federal level (Health Canada) need to be re-examined to promptly resolve this issue.
BONUS 5: 5th Annual Bone and The Oncologist New Updates
Authors: Bouganim N. , Amir E. , Clemons M.
Published: July 2010

The 5th annual Bone and The Oncologist New Updates (BONUS 5) conference, held at the National Arts Center, Ottawa, April 8–9, 2010, focused on innovative research into the mechanisms and consequences of increased bone turnover in the benign and metastatic settings alike. This year there was also a debate over the controversial use of bisphosphonates as an adjuvant treatment in patients with early-stage breast cancer. This meeting report highlights a few of the topics presented.
Cetuximab in Locally Advanced Head-And-Neck Cancer: Defining the Population
Authors: Ho C.
Published: July 2010

Encouraging data for targeted therapy in head-and-neck squamous cell carcinoma are opening new options for treatment. Phase III trials of cetuximab, an antibody directed against the epidermal growth factor receptor (EGFR) have demonstrated benefit in the locally advanced and metastatic settings. Recognizing the importance of emerging therapies, Cancer Care Ontario published guideline recommendations for EGFR-targeted therapy in stage III and IV head-and-neck cancer. The present paper takes a further look at the population for whom an offer of cetuximab therapy may be appropriate.
Optimizing the Management of her2-Positive Early Breast Cancer: The Clinical Reality
Authors: Verma Su. , Lavasani S. , Mackey J. , Pritchard K. , Clemons M. , Dent S. , Latreille J. , Lemieux J. , Provencher L. , Verma Sh. , Chia S. , Wang B. , Rayson D.
Published: July 2010

Breast cancer positive for HER2 (human epidermal growth factor receptor 2) is associated with a poor prognosis for patients with both early-stage and metastatic breast cancer. Trastuzumab has been shown to be effective and is now considered the standard of care for early-stage patients with HER2-positive breast cancer. In that population, trastuzumab has been studied in six randomized clinical trials. Overall, use of this agent leads to a significant reduction in risk of disease recurrence and improvement in overall survival. Despite the strong evidence for the use of trastuzumab in managing HER2-positive early breast cancer (EBC), a number of clinical controversies remain. The authors of this paper undertook a review of the available scientific literature on adjuvant trastuzumab to produce practical considerations from Canadian oncologists. The panel focused their discussion on five key areas: (1) Management of node-negative disease with tumours 1 cm or smaller in size; (2) Management of HER2-positive EBC across the spectrum of the disease (that is, nodal and steroid hormone receptor status, tumour size); (3) Timing of trastuzumab therapy with chemotherapy for early-stage disease: concurrent or sequential; (4) Treatment duration of trastuzumab for EBC; (5) The role of non-anthracycline trastuzumab-based regimens.
«Brazos para el azúcar», esclavos para vender. Estrategias de comercialización en la trata negrera en Santiago de Cuba, 1789-1794
Authors: Belmonte Postigo José Luis
Published: July 2010

El presente trabajo analiza las estrategias de comercialización de los tratantes de esclavos en Santiago de Cuba en los primeros años de la liberalización. Tras conseguir la habilitación del puerto de Santiago de Cuba al comercio de negros, en el año 1789, el número de esclavos introducidos en la capital del Oriente cubano se incrementó sustancialmente. Sin embargo, la entrada de estos esclavos no significó necesariamente que quedaran fijados en la plaza o su hinterland, ya que su reventa servía como modo de capitalización para el vendedor debido a la extraordinaria demanda existente en toda la región.
Variable Range Hopping (VRH) Model in Manganese Oxides
Authors: Huda Abdullah
Published: July 2010

This is a study of data analyzing by using a theoretical model for mixed-valence manganites Ln1−xAxMnO3, which exhibit a complex transport behaviour. In the high-temperature (T>TP) paramagnetic insulating regime, the resistivity of samples obeys the T-1/4 law, characteristic of variable range hopping (VRH). We address this kind of transport process as involving variable-range hopping of small polarons, and derive the resistivity expression: .
Theoretical Studies of the EPR Parameters for Rh+ in NaCl
Authors: Zhang Zhi Hong , Wu Shao Yi , Xu Pei , Li Li Li
Published: July 2010

The electron paramagnetic resonance (EPR) parameters g factor and the hyperfine structure constant A factor for the substitutional Rh+ in NaCl are theoretically studied from the perturbation formulas of these parameters for a 4d8 ion in cubic octahedra. In these formulas, the ligand orbital and spin-orbit coupling contributions which were normally omitted in the previous studies are taken into account using the cluster approach. The calculated g and A factors are in good agreement with the experimental data. The ligand contributions to the EPR parameters are somewhat important and should be considered in the analysis of the EPR spectra for a 4d8 ion in chlorides. The local structure of this center is also discussed.
Artificial Aging Behavior of 6063 Alloy Studied Using Vickers Hardness and Positron Annihilation Lifetime Techniques
Authors: Abdel-Rahman M.A. , El-Deen Alaa , El-Nahhas Alaa El-Deen A. , Lotfy Yahia A. , Badawi Emad A.
Published: July 2010

Many aluminum-based alloys are strengthened by a heat treatment process known as age hardening. The aim of this work was to produce a high-strength 6xxx series aluminum alloy by adjusting the processing conditions, namely solutionizing and artificial aging. It consists of heating the alloy to a temperature at which the soluble constituents will form an homogeneous mass by solid diffusion, holding the mass at that temperature until diffusion takes place, then quenching the alloy rapidly to retain the homogeneous condition. In the quenched condition, heat-treated alloys are supersaturated solid solutions that are comparatively soft and workable, and unstable; depending upon the composition. After solution treatment and quenching, hardening is achieved either at room temperature (natural aging) or by precipitation heat treatment at a suitable temperature (artificial aging). Precipitation heat treatments are generally low-temperature long-term processes. Temperatures range from 115 to 190°C and times vary from 5 to 48 h. Choice of time-temperature cycles for precipitation heat treatment should receive careful consideration. The objective is to select the cycle that produces the optimum precipitate size and distribution pattern. The mechanical characterization of heat-treatable 6xxx (Al-Mg-Si-Cu based) 6063 wrought aluminum alloys was studied. Their effects were investigated in terms of the microstructure, using positron annihilation lifetime techniques and mechanical properties monitoring via Vickers hardness measurements. The hardness is the resistance of a material to plastic deformation, which gives it the ability to resist deformation when a load is applied. The greater the hardness of the material, the greater the resistance it has to deformation. The hardness of 6063 alloy has its maximum value (58) when aged for 8 hours at 175oC after quenching from 520oC; which is the solution temperature of this alloy. The hardness conformed to the literature. We also test the aging ability of the 1xxx aluminum alloy: 1050.
Analysis of the Solid Solution Microstructure of (HF) Al-Zn Alloys
Authors: Bedboudi H. , Bourbia A. , Draissia M. , Boulkhessaim S. , Debili M.Y.
Published: July 2010

Rapidly solidified Al-Zn alloys with Zn contents ranging up to 50 wt.% were made under vacuum, by high-frequency (HF) induction melting, from compacted mixture targets of Al and Zn of fine (99.99 % purity) elemental powders. The microstructural characteristics and strengthening mechanisms were investigated. The crystallographic microstructures were characterized by means of X-ray diffraction (XRD) analyses and optical microscopy observations as well as Vickers microhardness testing. Detailed overviews of alloying solubility of zinc in aluminium were given. Extensive solid solutions of CFC Al were found in the (HF) Al-Zn alloys, and a higher Vickers microhardnesses compared to that of pure (HF) aluminium.
Effect of Microstructure upon the Wear Properties of 2.25Cr-1Mo Steel
Authors: Jha B.B. , Mishra Barada Kanta , Sahoo T.K. , Mukherjee P.S. , Ojha S.N.
Published: July 2010

The present paper investigates the effect of microstructural variations upon the wear properties of 2.25Cr-1Mo steel using a dry sliding wear test. Optical, Scanning and Transmission Electron Microscopy (TEM) together with Energy Dispersive X-ray analysis (EDX) have been used to characterize the microstructures and identify the evolution of various precipitates in terms of their shapes, sizes and morphologies. The wear behavior of this steel was investigated using a disc-on-roller multiple wear tester under dry sliding conditions, rubbing against EN-31 steel. Samples were tested at 100N load and 500rpm sliding speed at room temperature. A decrease in wear loss was measured continuously for up to one hour for all the samples. The results indicated that the wear behavior of this steel was highly influenced by microstructural variations taking place during service exposure. The precipitation of globular Cr- and Mo-rich carbides has been found to improve the wear behavior of this steel at room temperature. Scanning Electron Micrographs (SEM) of worn surfaces have been used to correlate the results obtained
Preparation and Characterization of Pd-Based Optical Hydrogen Sensor Operated at Room Temperature by Using Photodeposition Process
Authors: Hamagami Junichi , Araki Ryo , Oda Hiroyuki , Sakai Mototsugu , Matsuda Atsunori
Published: July 2010

Palladium (Pd) nanoparticles were prepared on photocatalytic TiO2-coated glass substrate by a photodeposition process and the optical hydrogen sensing properties were examined at room temperature. The TiO2 coatings were prepared on a non-alkaline glass substrate by a sol-gel process and hot water treatment. Pd nanoparticles were deposited on the TiO2 film by photodeposition using UV light. The obtained Pd/TiO2 thin film showed remarkable optical transmittance response to hydrogen gas at room temperature. The normalized transmittance of the Pd/TiO2 thin film at a wavelength of 640 nm decreased to 0.9 on exposing the film to hydrogen gas for only 5 s. This transmittance decrease is considered to be due to a gaschromic effect of the TiO2 photocatalytic coating.
Magnetic and Dielectric Properties of Cr2O3/LiNbO3/Cr2O3 Multi Layer
Authors: Yokota Takeshi , Tsuboi Yasutoshi , Murata Shotaro , Kito Shinya , Gomi Manabu
Published: July 2010

We proposed a new type of multi-ferroic system using magnetoelectric (ME:Cr2O3) material/ultra-thin ferroelectric materials (FE)/a magnetoelectric material hetero structure. This ME and FE heterosystem showed a general Polarization – Electric field hysteresis curve. When a magnetic and electric field (ME field) was applied at the same time, a decrease of polarization was observed. This might be due to the antiferromagnetic domain alignment of Cr2O3 by the ME field.
Fabrication and Microstructure of Grain-Oriented (Bi1/2K1/2)TiO3 Ceramics
Authors: Saitoh Masahiro , Hiruma Yuji , Nagata Hajime , Takenaka Tadashi
Published: July 2010

Grain-oriented (Bi1/2K1/2)TiO3 (BKT) ceramics were prepared by the reactive templated grain growth (RTGG) method, and a hot-pressing (HP) method was modified on the basis of the RTGG method to obtain dense ceramics. The BKT ceramic sintered at 1060°C showed a single-phase perovskite structure. The grain-oriented BKT prepared by the HP method exhibited a relatively high orientation factor F of 0.82 and a high density ratio of 99%. SEM micrographs of the HP-grain-oriented BKT indicated a textured and poreless microstructure. On the basis of the density ratio of 87% for the grain-oriented BKT without HP, the HP method was considered very effective for improving the density ratio even for the RTGG sample. In addition, the resistivity of the HP-grain-oriented BKT was 1.73 x 1013 •cm.
Tunable Barium Strontium Titanate Thin Films by CSD
Authors: Iwasaki Dai , Maruyama Miho , Sakamoto Naonori , Fu De Sheng , Wakiya Naoki , Suzuki Hisao
Published: July 2010

BaxSr1-xTiO3 (BST) thin films were deposited by modified CSD, in which partially hydrolyzed Ti-alkoxide was reacted with Ba-Sr precursor solution to form highly polymerized BST precursor solutions, leading to the better electrical properties of the resultant thin films. BST precursor solutions of 0.1 M were prepared to deposit BST thin layers of 17nm ~ 20nm for one dip-coating operation with different barium to strontium ratio of Ba/Sr = 90/10, 70/30 and 50/50. Modified CSD-derived BST thin films were deposited on a Si wafer with Pt electrode or CSD-derived LaNiO3 (LNO) seeding layer with preferred orientation. BST thin films exhibited ferroelectric or paraelectric properties, depending upon the Ba/Sr ratio. Better electrical properties for the BST thin films were observed on a LNO seeding layer. Maximum tunability of our BST film was 41 % at 1MHz.
Characteristics of Hot Spot Oxygen Sensor Using GdBa2Cu3O7-δ Ceramic Rod with Gd2BaCuO5 Core
Authors: Fujihara Shingo , Kuroki Yuichiro , Okamoto Tomoichiro , Takata Masasuke
Published: July 2010

A ceramic rod of GdBa2Cu3O7-δ with Gd2BaCuO5 core was prepared using a dip coater and sintered at 950oC. A hot spot appeared when a certain voltage was applied to the rod. Oxygen sensing characteristics of the rod were investigated. It was found that the response time of the oxygen sensor using the rod with the core was shorter than that without the core, because the length of the oxygen diffusion in GdBa2Cu3O7-δ part in the rod with the core was shorter than that without the core.
Dielectric Properties of Barium Titanate Ceramics with Nano-Sized Domain
Authors: Kigoshi Yoichi , Hatta Saki , Teranishi Takashi , Hoshina Takuya , Takeda Hiroaki , Sakurai Osamu , Tsurumi Takaaki
Published: July 2010

Barium titanate (BaTiO3) ceramics with various grain sizes from 0.7 to 13 μm on average were prepared by a conventional sintering method, a two-step sintering method and a rate controlled two-step sintering method. The permittivity of the ceramics was increased with decreasing grain size to 1.1 μm on average. However, the permittivity of the ceramics was decreased when the grain size was below 1 μm. The field emission scanning electron microscope (FE-SEM) observations revealed that the 90º domain width decreased with decreasing the grain size. By ultrawide range dielectric spectra from kHz to THz range of the BaTiO3 ceramics, the domain contribution to the permittivity was investigated. For the BaTiO3 ceramics with grain sizes over 1 μm, the dipole polarizability and the ionic polarizability were enhanced by high domain-wall density. In contrast, for the BaTiO3 ceramics with grain sizes below 1 μm, these polarizabilities were weakened.
Degradation of Resistance over Time for Multilayer Ceramic Capacitors
Authors: Morita Koichiro , Mizuno Youichi , Chazono Hirokazu
Published: July 2010

The lifetime determination model for multilayer ceramic capacitors (MLCCs) is discussed. The accumulation of oxygen vacancies on the cathode/ceramics interface by an electro-migration process is a concept accepted by many researchers. However, the lifetimes and leakage currents measured during a highly accelerated lifetime test (HALT) could not be explained by this concept. To investigate the mechanism, we used a polarity reversal method during the HALT, which provided information on the dominant process for the leakage current. Thermally stimulated current (TSC) measurement provided the relative number of oxygen vacancies both on the cathode/ceramics interfaces and the grain boundaries. Moreover, the microstructure of the MLCC samples was evaluated by both electric property measurements and direct observation. From these results, we concluded that the grain boundaries controlled the leakage current as well as the lifetime.
Nonlinear Shear Response in (K,Na)NbO3-Based Lead-Free Piezoelectric Ceramics
Authors: Hagiwara Manabu , Takahashi Seita , Hoshina Takuya , Takeda Hiroaki , Sakurai Osamu , Tsurumi Takaaki
Published: July 2010

The piezoelectric shear response of 94.0(Ka0.5, Na0.5)NbO3 (KNN) + 5.0LiNbO3 (LN) + 0.5SrTiO3 (ST) + 0.5BiFeO3 (BF) ceramics was investigated by Laser Doppler Vibrometry (LDV) and resonance-antiresonance method. From resonance-antiresonance method, the piezoelectric d15 constant was obtained to be 273 pC/N. The shear strain obtained by LDV　at the frequency of 150kHz showed strong nonlinearity. This suggested that the domain contribution to piezoelectric response in shear mode of KNN-LN-ST-BF ceramics existed at the operational frequency for the shear mode divices.
Fabrication of Nanostructured NiO Thick Films by Facile Printing Method and their Dye-Sensitized Solar Cell Performance
Authors: Sakurai Koji , Fujihara Shinobu
Published: July 2010

Nanostructured NiO thick films were fabricated for use in dye-sensitized solar cells (DSCs) as photocathodes. Pastes were prepared by using nanocrystalline NiO powders, polyethylene glycol (PEG) and water. The pastes were then printed on FTO glass substrates by a facile doctor-blade printing method. The NiO films were obtained by heating at 500 °C for 30 min in flowing oxygen. It was shown that the nanostructure of the resultant films was largely dependent on the amount of PEG in the pastes. Coumarin 343 (C343) dye was employed for sensitizing p-type NiO photocathodes. DSCs using our NiO/C343 photocathodes yielded a photocurrent density of 1.26 mA cm–2, an open-circuit photovoltage of 88 mV, a fill factor of 0.33, and a solar energy conversion efficiency of 0.037 %.
Preparation and Characterization of La0.8Sr0.2Ga0.8Mg0.2O3-δ Film by Electrophoretic Deposition Method
Authors: Toriyama Araki , Myoujin Kenichi , Kodera Takayuki , Ogihara Takashi
Published: July 2010

La0.8Sr0.2Ga0.8Mg0.2O3-δ (LSGM) precursor particles were successfully prepared by ultrasonic spray pyrolysis. LSGM thin films were prepared by the electrophoretic deposition (EPD) technique using ethanol containing iodine. The LSGM films were obtained by sintering at 1300 °C for 10 h. The X-ray diffraction patterns revealed that the diffraction peak of LSGM thin films was in agreement with the perovskite structure. The LSGM films attained a uniform thickness of 10 μm.
Synthesis and Electrochemical Properties of Porous LiAl0.05Mn1.95O4 for High Power LIB by Spray Pyrolysis
Authors: Kodera Takayuki , Hirose Syoji , Ogihara Takashi
Published: July 2010

Spherical LiAl0.05Mn1.95O4 precursor powders were successfully prepared by spray pyrolysis. LiAl0.05Mn1.95O4 precursor powders were calcined by 800°C for 10hrs. The particles size, morphology, microstructure, crystal phases of the calcined powders were characterized by X-ray diffraction (XRD) and a scanning electron microscope (SEM). The XRD patterns showed that the crystal phases of the calcined powders were the same as spinel phase (space group: Fd3m). The particles exhibited a spherical morphology with a porous microstructure. The particle size of the primary particles was approximately 200nm. LiAl0.05Mn1.95O4 cathodes exhibited higher rechargeable capacity and cycle stability at high rates. The particle microstructure of LiAl0.05Mn1.95O4 powders was effective for the rechargeable capacity at high rates.
Experimental Characterization of Behavior Laws for Titanium Alloys: Application to Ti5553
Authors: Wagner Vincent , Baili Maher , Dessein Gilles , Lallement Daniel
Published: July 2010

The aim of this paper is to study the machinability of a new titanium alloy: Ti-5AL-5Mo-5V-3CR used for the production of new landing gear. First, the physical and mechanical properties of this material will be presented. Second, we show the relationship between material properties and machinability. Third, the Ti5553 will be compared to Ti64. Unless Ti64 is α+β alloy group and Ti5553 is a metastable, we have chosen to compare these two materials. Ti64 is the most popular of titanium alloys and many works were been made on its machining. After, we have cited the Ti5553 properties and detailed the behavior laws. They are used in different ways: with or without thermal softening effect or without dynamic terms. The goal of the paper is to define the best cutting force model. So, different models are compared for two materials (steel and titanium alloy). To define the model, two methods exist that we have compared. The first is based on machining test; however the second is based on Hopkinson bar test. These methods allow us to obtain different ranges of strain rate, strain and temperature. This comparison will show the importance of a good range of strain rate, strain and temperature for behavior law, especially in titanium machining.
Effect of Ductile Damage Evolution in Sheet Metal Forming: Experimental and Numerical Investigations
Authors: Abbassi Fethi , Pantalé Olivier , Mistou Sébastien , Zghal Ali , Rakotomalala Roger
Published: July 2010

The numerical simulation based on the Finite Element Method (FEM) is widely used in academic institutes and in the industry. It is a useful tool to predict many phenomena present in the classical manufacturing forming processes such as necking, fracture, springback, buckling and wrinkling. But, the results of such numerical model depend strongly on the parameters of the constitutive behavior model. In the first part of this work, we focus on the traditional identification of the constitutive law using oriented tensile tests (0°, 45°, and 90° with respect to the rolling direction). A Digital Image Correlation (DIC) method is used in order to measure the displacements on the surface of the specimen and to analyze the necking evolution and the instability along the shear band. Therefore, bulge tests involving a number of die shapes (circular and elliptic) were developed. In a second step, a mixed numerical–experimental method is used for the identification of the plastic behavior of the stainless steel metal sheet. The initial parameters of the inverse identification were extracted from a uniaxial tensile test. The optimization procedure uses a combination of a Monte-Carlo and a Levenberg-Marquardt algorithm. In the second part of this work, according to some results obtained by SEM (Scaning Electron Microscopy) of the crack zones on the tensile specimens, a Gurson Tvergaard Needleman (GTN) ductile model of damage has been selected for the numerical simulations. This model was introduced in order to give informations concerning crack initiations during hydroforming. At the end of the paper, experimental and numerical comparisons of sheet metal forming applications are presented and validate the proposed approach.
The Effect of the Cure Temperature on the Thermomechanical Characteristics of an Adhesive
Authors: Ali Mohamad , Lorrain Bernard , Karama Moussa , PUEL Bernard
Published: July 2010

The origin of this work takes place in the framework of an industrial collaboration in order to study the behavior of a mechanical joint, used in the industry of railway structures. One problem in using the structural adhesive in the industry is hygrothermal ageing. In these papers; the effect of the adhesive cure temperature on the mechanical properties of a commercial bi-component epoxy bonding joint will be studied. Usually the bi-component epoxy is cured at room temperature. The industrial goal in this study is to increase the mechanical performances of adhesively bonded structures. To achieve this goal the curing process of the adhesive will be optimized.
Dynamic Response of Symmetric and Asymmetric E-Glass / Epoxy Laminates at High Strain Rates
Authors: Tarfaoui Mostapha , Choukri S. , Neme A.
Published: July 2010

The mechanical properties of E-glass/epoxy composite at high strain rates are important in evaluating this kind of composite under dynamic and impulsive loading. The in-plane and out-of-plane compressive properties at strain rates from 300 to 2500 s-1 were tested with split Hopkinson pressure bar. Samples were tested in the thickness as well as in-plane direction for seven fibre orientations: 0°, 20°, 30°, 45°, 60°, 70° and 90°. The kinetics of damage and the failure modes were identified using a high-speed photography, infrared camera, optical techniques and a scanning electron microscope. Results of the study were analyzed in terms of maximum stress, Strain at maximum stress, failure modes, damage history and fibres orientation effects. From the experimental data, the stress-strain curves, compressive stiffness, and compressive strain of the composite are rate-sensitive in in-plane and out-of-plane compressive directions. The failure and damage mechanisms are implicitly related to the rise in temperature during static and dynamic compression.
Influence of Process and Material Parameters on Impact Response in Composite Structure: Methodology Using Design of Experiments
Authors: Garnier Christian , Mistou Sébastien , Pantalé Olivier
Published: July 2010

Even if the mechanical performances of composite materials give new perspectives for the aircraft and space design, the variability of their behavior, linked to the presence of initial microscopic defects or led in service, constitute however a still important brake in their development. As regards particularly the response to fatigue loads or ageing, the behavior of these materials is affected by several sources of uncertainties, notably on the nature of the physical mechanisms of degradation, which are translated by a strong dispersion in life time. In aerospace industry, low energy impact phenomenon is not well known concerning composite materials and composite structures. Many manufacturers use important safety factors to design structures. The aim of this work is to define the most predominant parameters which permit a good response of damage using experiences plans. The differences of these parameters by using Resin Transfer Molding (RTM) or Liquid Resin Infusion (LRI) process than prepreg one is also studied in this work.
Components for PEM Fuel Cells: An Overview
Authors: Maiyalagan T. , Pasupathi Sivakumar
Published: July 2010

Fuel cells, as devices for direct conversion of the chemical energy of a fuel into electricity by electrochemical reactions, are among the key enabling technologies for the transition to a hydrogen-based economy. Among the various types of fuel cells, polymer electrolyte membrane fuel cells (PEMFCs) are considered to be at the forefront for commercialization for portable and transportation applications because of their high energy conversion efficiency and low pollutant emission. Cost and durability of PEMFCs are the two major challenges that need to be addressed to facilitate their commercialization. The properties of the membrane electrode assembly (MEA) have a direct impact on both cost and durability of a PEMFC.
An overview is presented on the key components of the PEMFC MEA. The success of the MEA and thereby PEMFC technology is believed to depend largely on two key materials: the membrane and the electro-catalyst. These two key materials are directly linked to the major challenges faced in PEMFC, namely, the performance, and cost. Concerted efforts are conducted globally for the past couple of decades to address these challenges. This chapter aims to provide the reader an overview of the major research findings to date on the key components of a PEMFC MEA.
Advanced Membrane Materials for Fuel Cell Applications
Authors: Zaidi S. M. Javaid
Published: July 2010

Fuels are being considered an as environmental friendly technology and are making headlines across the globe as clean and reliable alternate energy source for transportation, stationary and portable power applications. The rapid developments taking place in all the leading research laboratories in the world are making fuel cell closer to the realization. The progress of PEM fuel cell is closely related to the development of solid polymer electrolyte membranes as it defines the properties needed for other components of the fuel cell. So far perfluorosulfonated membranes such as Nafion have been found useful in these fuel cells and are the only material of choice available commercially. But these membranes are very expensive and have other drawbacks, which acts as an impediment for the commercialization of this technology. As a result alternative cheaper membrane materials have been developed. For the development of new or novel membranes mainly three strategies have been used: (1) modifying the currently used ionomer membranes (2) synthesizing new polymeric membranes and (3) develop new polymer composites by blending the two polymers or composting with an inorganic material. The composite membrane approach (3) has been widely used to tackle the problem of methanol crossover and temperature stability.
Preparation and Characterization of Thermoplastic Soy Protein Isolate
Authors: Lu Yan , Luo Xue Gang , Lin Xiao Yan , He Pan
Published: July 2010

A soybean protein isolate (SPI) main chain grafted with methyl acrylate (MA) and methyl methacrylate (MMA) as a new thermoplastic copolymer (T-SPI) was prepared. The properties of the material were evaluated with DSC, FT-IR, and rotary rheometry. The results indicated that the monomer was grafted on SPI successfully. The T-SPI had a glass transition at about 66°C. T-SPI was a typical viscoelastic material, and its elastic ratio was 65.27%, the shear viscosity was very sensitive to temperature and the flowability of T-SPI was regulated by temperature.
Effect of Electron Beam Irradiation on the Properties of Polyethylene Oxide–TiO2 Composite Electrolyte for Dye Sensitized Solar Cells
Authors: Shaheer Akhtar M. , Kim Ui Yeon , Choi Dae Jin , Yang O Bong
Published: July 2010

The e-beam irradiation technique was found to be a new efficient method to improve and control the morphological and electrochemical properties of composite electrolytes of polyethylene oxide (PEO) and TiO2 for dye-sensitized solar cell (DSSC). PEO was irradiated by electron beam (e-beam) with energy source 2 MeV from 60 to 240 kGy doses at the dose rate of 15 kGy/min. The transition and amorphous phases of PEO were significantly increased upon the e-beam irradiation. Optimum e-beam irradiation was 60kGy in terms of degree of cross linking and amorphicity for the efficient ion conduction electrolytes. However, the properties of polymer and composite electrolytes were deteriorated after irradiation of > 60 kGy. The prepared composites with PEO/60kGy and TiO2 (PEO/60kGy-TiO2) showed significantly improved morphological and ionic conductivity properties of electrolyte for DSSC. DSSC fabricated with PEO/60kGy-TiO2 showed drastically increased conversion efficiency of 4.52% as compared to DSSC fabricated with bare PEO (conversion efficiency = 1.9%).
Study on the Static Recrystallization Behavior of Thermal Deformation of Austenitic Stainless Steel for Nuclear Power
Authors: Liu Jie , Fan Guang Wei , Han Pei De , Yang Jian Feng , Liu Jian Sheng , Ge Dong Sheng , Qiao Guan Jun
Published: July 2010

Dual-interval compression test was carried out with Gleeble-1500D thermal simulation testing machine on the 304 austenitic stainless steel used for nuclear power. The first-interval strain was 0.3, and the second 0.05, and the dual-interval strain rates is 0.1s-1, dual-interval temperatures of thermal deformation were 950°C, 1000°C, and 1050°C respectively. The softening behavior with thermal deformation at different temperatures and time intervals was studied. It was shown in the study that the occurrence of static softening was very easy for the material; the activation energy for static recrystallization Qrex was 383.45 kJ / mol in case of true strain of 0.3 and strain rate of 0.1s-1.
Novel Preparation of Silver-Coated Copper in Aqueous Solution
Authors: Song Yong Hui , Su Ting , Yang Yong , Lan Xin Zhe , Zhan Huan
Published: July 2010

Hollow and solid spherical silver-coated copper powders with size of 1μm were facilely prepared by the reduction of silver nitrate in the polyvinyl pyrrolidone (PVP) dispersed copper hydrosol solution at room temperature in the presence of hydrazine hydrate. Scanning electron microscopy and X-ray diffraction were conducted to investigate the formation process of silver-coated copper core-shell particles. The results showed that the absorption and deposition of the Ag nuclei initially occurred at the active sites on the core surfaces as seeds which urged the further deposition of silver species to form sprinkled-structure core-shell particles. During the growth of the silver shell, the dissolution of copper core would result in the formation of hollow spherical particles, while the hydrazine hydrate would help to generate the solid spherical silver-coated copper powders.
Effect of Foaming Temperature on Pore Morphology of Al/AlN Composite Foam Fabricated by Melt Foaming Method
Authors: Song Yeong Hwan , Tane Masakazu , Ide Takuya , Seimiya Yoshihiro , Hur Bo Young , Nakajima Hideo
Published: July 2010

Al foams whose matrix contains dispersed AlN particles (Al/AlN composite foams) were prepared by a melt foaming method, and the effect of foaming temperature on the pore morphology of the prepared foams was investigated. First, Al/AlN composites were prepared by non-compressive infiltration of Al powder compacts with molten Al alloy in nitrogen atmosphere. Next, the prepared composites were melted by induction heating and foamed at various temperatures using TiH2 powders as blowing agents. The porosity of prepared Al/AlN composite foams slightly decreases with increasing foaming temperature, and the pore morphology of the foam becomes homogeneous simultaneously. When the foaming temperature is 1123 K, homogeneous pores are formed in all over the ingot. This pore homogeneity is probably achieved by the stabilization of the foaming behavior due to the formation of Al3Ti particles in the melt and dispersion of AlN particles.
Formation of Hollow and Porous Nanostructures of Iron Oxides via Oxidation of Iron Nanoparticles and Nanowires
Authors: Nakamura Ryusuke , Nakajima Hideo
Published: July 2010

Changes in morphology during the oxidation of iron nanoparticles and nanowires at 473~ 873 K have been studied by transmission electron microscopy. Iron nanoparticles and wires become hollow nanoparticles and nanotubes of Fe3O4 at temperatures below 673 K as a result of vacancy aggregation in the oxidation process. On the other hand, the hollow magnetite transforms into duplex porous structures with an interior nanopore and additional nanovoids at higher temperatures above 673 K, where the shrinkage of hollow nanoparticles and nanotubes starts and the phase transformation from Fe3O4 to -Fe2O3 occurs. Transition in porous structure seems to be related to the outward diffusion of vacancies from interior pore and the phase transformation in the shrinkage process.
Fabrication of Lotus-Type Porous Al-Ti Alloys Using the Continuous Casting Technique
Authors: Kim Tae Bum , Suzuki Shinsuke , Nakajima Hideo
Published: July 2010

Porous Al-5mass%Ti alloys were fabricated using a continuous casting technique in a hydrogen atmosphere, and the effects of transfer velocity (V) and the peritectic solidification process on the pore morphology and matrix microstructure were examined. In the case of V = 0.5 mm/min, columnar microstructure and directional pores grow along the transfer direction. The Al3Ti phases are formed in localized regions of matrix part, and however, they do not suppress the growth of directional pores in the other regions. In the case of 5.0 mm/min, because needle-like Al3Ti phases grow along the transfer direction, directional pores can grow between them. On the other hand, in the case of 10.0 mm/min, spherical pores surrounded by equiaxed peritectic microstructure and homogeneously distributed Al3Ti phases are formed, because the primary α -Al and Al3Ti phases probably prevent the growth of directional pores.
Hot Corrosion of NiCrAlY/(ZrO2-CeO2-Y2O3) Composite Coatings in NaCl-Na2SO4 Molten Salt
Authors: Lee Jae Ho , Lee Dong Bok
Published: July 2010

The metal/ceramic composite coatings that consisted of (Ni-22Cr-10Al-1Y) and (ZrO2-25CeO2-2.5Y2O3) were prepared by the air plasma spray (APS) method. The as-sprayed coatings consisted of metal-rich and ceramic-rich regions, between which the -Al2O3 oxide stringers existed owing to the oxidation of Al in (Ni-22Cr-10Al-1Y) during APS. The composite coatings were hot corroded at 800 and 900 oC for up to 50 h in 75%NaCl-25%Na2SO4 molten salt. The corrosion products that formed on the coating surface during hot corrosion were mostly dissolved off into the molten salt. The scales that remained on the coating surface consisted primarily of Cr2O3, and a lesser amount of NiO and Al2O3. The corrosion resistance decreased, as not only the test temperature and time but also the amount of metal in the coating increased.
Experiment on Combustion-Supporting Agent on PCI for Combustibility of Coal Powder
Authors: Yang Shuang Ping , Dong Jie , Wang Miao
Published: July 2010

In order to improve the combustion effects of pulverized coal and replacement ratio of coals, the combustion- supporting mechanism, development and applications are analyzed and industry experiment are carried out based on the research of combustion- supporting agent without alkalis on coals combustion with TG- DTG- DSC ways. The results show that there is an optimum addition percent for coals combustion with combustion- supporting agent. The coal ratio and coke ratio are improved obviously with 1.7%combustion- supporting agent in LongGang.
Influence of Vanadium on Aging Characteristics of Cold Rolled Cu-Ni-Si Alloy
Authors: Que Zhong Ping , Jung H.M. , Lee J.H. , Euh Kwang Jun , Han Seung Zeon
Published: July 2010

In order to investigate the influence of vanadium on aging dynamics of Cu-Ni-Si alloy, the microstructure, hardness and electrical conductivity of the cold rolled Cu-Ni-Si alloys with varying V content were systematically studied. The results show that V can postpone the recovery and accelerate the precipitation with (NiV)2Si compound. Consequently, V can increase hardness obviously. However, because of the precipitation during the hot rolling procedure, V addtion has a little harmed to electrical conductivity.
Strength Enhancement of Geopolymer-Based Concretes by Mixed Alkaline Activators
Authors: Yang Z. X. , Hwang Kyu Hong , Kim M.C. , Yang J.Y. , Lim S.K.
Published: July 2010

As a relatively new material, geopolymer concrete offers benefits as a construction material for sustainable development. It utilizes waste materials such as recycled concrete sludge, fly ash,etc. To reduce CO2 emission, geopolymer concrete is expected to replace the traditional Portland cement based concrete. It’s reported that geopolymer based concrete releases only 1/6 CO2 compared to those of based Ordinary Portland Cement (OPC). In this study, to obtain a new type of construction material with lower CO2 emission and energy consumption, fly ash, waste concrete sludge and metakaolin were used as the main components. Solution of NaOH/KOH and water glass were applied as alkaline activator. The amount of water glass and the ratio of alkaline/water glass were varied to reach an optimal value. Also, silica fume was added as a bonding matrix to enhance the strength, and the specimens were cured in air and oven, then their mechanical properties such as compressive strength and bending strength were measured and their microstructures were investigated.
Blow Forming of Lightweight Titanium Components
Authors: Lee Ho Sung , Yoon Jong Hoon , Yi Yeong Moo
Published: July 2010

The objective of this study is to fabricate lightweight structural panels and pressurized tanks by blow forming of solid-state bonded Ti-6Al-4V sheets. The solid-state bonding process was conducted in selective areas of the sheets and gas pressure was applied to the core sheet in order to form center cells. The microstructure of bonded region shows no indication of any discontinuous or heterogeneous microstructure at interface. It is shown that the blow forming of a lightweight sandwich structural panel and a sphere vessel was successfully performed with solid-state bonded multiple sheets of titanium alloy. The result of configuration and thickness distribution measurement indicate that the FEM analysis can predict the forming behavior during blow forming process of solid-state bonded sheets.