bluuebunny/crossref_metadata_2025 huggingface dataset:
The Effects of Ni Content and Intermediate Annealing Condition on Recrystallization of Al-Fe-Ni-Si Alloy Fin Stocks
Authors: Suzuki Kenta , Shimosaka Daisuke , Sasaki Tomohiro , Owada Yasuyuki , Kuroiwa Shuhei , Anami Toshiya
Published: November 2016

The effects of Ni content and intermediate annealing conditions on recrystallization behavior during brazing heat treatment of Al–Fe–Ni–Si alloys fin stocks of automotive heat exchangers were studied by means of microstructural analysis. Following brazing heat treatment, coarsening of recrystallized grain structure was observed in both 0.5% Ni and 1.0% Ni fin stocks, which were intermediately annealed in a salt bath. This coarsening was particularly marked in 1.0% Ni fin stocks. The results of the microstructural observations indicated that fine dispersoids were heterogeneously dispersed in 1.0% Ni fin stocks that were annealed at 550°C for 10 s in a salt bath. It was proposed that the preferential recovery and recrystallization during the brazing heat treatment in the low density area of the fine dispersoids contributed to the larger recrystallized gain structure. The coarse recrystallized grains obtained by controlling the salt bath annealing conditions are expected to contribute in improving the properties of Al–Fe–Ni–Si alloy fin stocks of automotive heat exchangers.
Apparent Morphology and Structure of Iron-Rich Phase in Aluminum Alloy
Authors: Li Ming , Hao Hu , Wang Yin Yin , Shi Zhi Ming
Published: November 2016

This work extracted the iron-rich phases in aluminium alloy containing the iron of 0.3%, 0.6%, 1%, 0.6%, 2% and 5% respectively, and studied the morphology and the structure of the iron-rich phases by using electrolytic extraction technology. The results showed that the iron-rich phase in aluminium alloy is a large number of alpha - Al3Fe and a small amount of lambda - Al13Fe4; the rich iron phases are distributed in aluminum alloy substrate in three-dimensional space, and its metallographic appearances in different sections present sheet, plate and needle-like structure. High resolution electron microscopy shows that lambda - Al13Fe4 and alpha - Al3Fe are tetrahedral structure, and when iron content is 0.3% - 1%, the iron-rich phase transition of lambda - Al13Fe4 to alpha - Al3Fe is influenced by iron content, and alpha - Al3Fe lattice constants a and c are bigger than that of standard value under 0.3% iron content, and alpha - Al3Fe lattice constant a changes little with the increase of iron content, and the lattice constant c becomes larger along with the increase of iron content, and when the iron content is up to 1%, the lattice constant a and c are gradually stabilized; lambda - Al13Fe4 lattice constant a and c are constant.
A Combined TEM and Atom Probe Approach to Analyse the Early Stages of Age Hardening in AA 6016
Authors: Engler Olaf , Schäfer C. , Brinkman Henk Jan , Marioara Calin D. , Kozuka Masaya , Shishido Hisao , Aruga Yasuhiro
Published: November 2016

In this study we aim at combining the results from transmission electron microscopy (TEM) and atom probe tomography (APT) to study the early stages of phase decomposition in the age hardening alloy AA 6016. Samples are subjected to different periods of natural ageing or artificial pre-ageing at elevated temperature in order to produce different types of clusters and early stages of precipitation before age hardening commences. APT is utilized to detect clusters and identify their compositions, whereas TEM is applied to analyse and quantify number density and sizes of the particles during artificial ageing at 185°C. It is shown that the two techniques, TEM and APT, are complementary and a combined approach yields more detailed insight into the early stages of phase decomposition in age hardening 6xxx series alloys than possible by the sole use of either technique individually.
Effect of the Deformation Parameters on the Microstructure of TiC-Al2O3P/Al Composites
Authors: Zhang Rui Ying , Wang Peng , Han Xiao Wei , Shi Zhi Ming , Zhao Ge
Published: November 2016

An aluminum matrix composite reinforced by TiC and Al2O3 particles was synthesized using TiO2, C, and Al powder by the in-situ reaction. The effects of deformation parameters on the microstructure of the TiC-Al2O3/Al composite were investigated using XRD, SEM and TEM. The result shows that the strain rate and deformation temperature influence the size, styles, and distribution of the second phase. Reinforcements are dispersed in a distribution with increasing deformation temperature and strain rate. However, broken Al3Ti exhibits redissolution phenomenon. The new precipitated Al3Ti phase will precipitate from the strain-induced solid solution when the total strain increases to a certain degree at a high deformation temperature.
Effect of Novel Thermomechanical Treatment on Microstructure and Properties of 6156 Alloy
Authors: Ren Jie Ke , Chen Zhi Guo , Chen Ji Qiang , Feng Shuai , Peng Jing
Published: November 2016

A novel thermomechanical treatment (TMT) was proposed for increasing the strength of 6156 aluminum alloy while maintaining a high elongation, which is based on artificial aging at low temperature, cold rolling and natural aging. The corresponding tensile properties and microstructure of 6156 aluminium alloy under different treatments were investigated. The yield strength and the ultimate tensile strength are increased by over 50 MPa over those of T3, while a high elongation rate is maintained. The fracture mechanism of T4 and TMT state alloy are typical ductile fracture, while that of T6 and T8 state alloy is a mixture of ductile fracture and shear fracture. For the TMT processed 6156 alloy, though no obvious precipitates can be observed in the matrix, tangled dislocations around primary phase in the matrix, as well as a high density of dislocations piled up at the grain boundary were observed. The mechanism of the novel TMT, by which the mechanical properties of the alloy is greatly improved, is the synergistic effect of composite structures, including dislocation substructures, the complex of Mg-Si clusters/vacancies, as well as GP zones.
Effects of Mn and Zr Addition in 6000 Series Aluminum Alloys on the Formation of Stabilized Substructures during Hot Deformation
Authors: Tanaka Hiroki , Nagai Yasunori
Published: November 2016

Thermal stability of substructures in 6000 series aluminum alloys containing Mn and Zr elements was investigated using plane-strain compression test. In order to form thermally stabilized substructures, the deformation parameters should be selected so as to correlate with kinetic precipitation during the deformation. For substructures of the alloys containing Mn and Zr elements, the substructures were stable during the heat treatment at 540 ̊C when the alloys were deformed at a temperature above 350 ̊C. The sheets rolled above 350 ̊C at a strain rate of under 3 s-1 per pass showed the fibrous structure and well developed β-fiber textures after the heat treatment at 540 ̊C. The sheets with the fibrous structure had an average Lankford value larger than one.
Effect of Solution Treatment on the Properties and Microstructural Evolution of Al-Zn-Mg-Cu-Er-Zr Alloy
Authors: Lu Jun Tai , Huang Hui , Wu Hao , Wen Sheng Ping , Gao Kun Yuan , Nie Zuo Ren
Published: November 2016

Effect of solution treatment on the properties and microstructural evolution of Al-Zn-Mg-Cu-Er-Zr alloy was investigated by hardness test, conductivity test, exfoliation corrosion test, scanning electron microscope (SEM), transmission electron microscopy (TEM). The results show that the hardness of single-stage solution treated samples first increase and then decrease, the conductivity and volume fraction of the residual phase particles decrease with increasing solution temperature. Compared to conventional multi-stage solution, slow heating process solution treatment can dissolve plenty of residual phases and further improve the hardness and decrease conductivity. Besides, the effect of solution treatment on EXCO is discussed, the result of exfoliation corrosion of SHT8 sample test is judged as EA. Moreover, the effect of the presence of nanometer-sized Al3(Er,Zr) particles on the microstructural evolution during solution treatment has also been discussed in detailed.
Effect of Natural Aging of 6xxx Series Extrusions on the Energy Absorbance Capacity
Authors: Vazdirvanidis Athanasios , Pantazopoulos George , Toulfatzis Anagnostis , Rikos Andreas , Manolakos Dimitrios
Published: November 2016

In this study the influence of natural aging in energy absorbance capacity of 6xxx series extruded profiles after artificial aging is examined by means of optical and scanning electron microscopy, quasi-static compression and tensile tests. Mobile quenched-in vacancies are found to play an important role in aging kinetics and formation of precipitate free zones (PFZs) which govern both the observed fracture modes and the resulting strength of the material signifying their important effect when maximum energy absorbance is desired. It is shown that fracture toughness of naturally aged samples is equivalent or higher compared to that of directly aged samples due to restriction of intergranular cracking.
Effects of Mg and Mn Contents on Hot-Rolling Temperature and Resultant Tensile Properties of Al-Mg-Mn Alloys
Authors: Kim Bong Hwan , Lee Ji Y. , Yoon Young Ok , Kim Shae K.
Published: November 2016

The effects of Mg and Mn contents on hot-rolling temperature and resultant tensile properties of Al-Mg-Mn alloys were investigated. The Al-3.5Mg-0.3 alloy as a reference and Al-7.5Mg-0.3Mn, Al-3.5Mg-1.0Mn alloys were prepared by casting for hot-rolling experiment. The rolling temperatures of both Al-7.5Mg-0.3Mn and Al-3.5Mg-1.0Mn alloys had to be decreased due to surface cracking during hot-rolling, which is caused by increased fractions of Mg-containing phases like Mg2Al3. The tensile strength of the hot-rolled Al-7.5Mg-0.3Mn alloy was highly increased by the combined effects of enhanced solid-solution and work-hardening at lower rolling temperature. And the resultant tensile strengths of the hot-rolled Al-3.5Mg-1.0Mn alloy were also increased due to dispersoid hardening by increased Mn content and work hardening during hot-rolling.
Study on the Ageing Process of the 6xxx Series Aluminum Alloy Wires for Overhead Conductors
Authors: Zhao Zhi Hao , Chen Qing Qiang , Zhu Qing Feng , Liu Wen Qiang , Wang Gao Song
Published: November 2016

The 6xxx series aluminium alloy wires (with the diameters of 2.84 mm) produced by the continuous drawing and rotary-wheel continuous casting, were directly aged in different conditions. The results show that, when ageing temperature is at 150°C, the tensile strength of the wire firstly decreased from 283 MPa to 265 MPa as the ageing time extended from 0 to 4 hours, and then increased from 265 MPa to 270 MPa as the ageing time extended from 4 to 12 hours, and finally decreased from 270 MPa 263 MPa as the ageing time extended from 12 to 24 hours. The electrical resistively of the wires continued decreases with the ageing time extend from 0 to 24 hours. When the ageing temperature is at 160, 170, 180 and 190 °C, both the tensile strength and the electrical resistively of the wire continuously decreased with the ageing time extended from 0 to 24 hours. When the ageing time was identical, the wires with higher ageing temperature possessed lower tensile strength and electrical resistively.
Precipitation Behaviour and Mechanical Properties during Short-Term Heat Treatment for Tailor Heat Treated Profiles (THTP) of Aluminium Alloy 6060 T4
Authors: Fröck Hannes , Graser Matthias , Milkereit Benjamin , Reich Michael , Lechner Michael , Merklein Marion , Kessler Olaf
Published: November 2016

Precipitation hardening aluminium alloys are widely used for automotive applications. To enhance the application of aluminium profiles, improved formability is needed. Tailor Heat Treated Profiles (THTP) with locally different material properties attempt to increase formability e.g. in bending processes. Tailoring of local properties is obtained by a local short-term heat treatment, dissolving the initial precipitate state (retrogression) and still allowing subsequent ageing. In the present study, the dissolution and precipitation behaviour of the aluminium alloy EN AW-6060 T4 was investigated during heating with differential scanning calorimetry (DSC). Heating curves from 20 to 600 °C with heating rates of 0.01 up to 5 K/s were recorded. Interrupted heat treatments with different maximum temperatures were performed in a deformation dilatometer. Immediately afterwards, tensile tests were carried out at room temperature. The course of the recorded mechanical properties as a function of the maximum temperature is discussed with regard to the dissolution and precipitation behaviour during heating. Finally, the aging behaviour of the investigated alloy was recorded after different typical short-term heat treatments and is discussed with reference to the DSC‐curves. The correlation of the microstructure and the mechanical properties enables the derivation of optimal parameters for the development of THTP through a local softening.
Microstructure and Mechanical Properties of 6013 Aluminium Alloy Processed by a Combination of ECAP and Preaging Treatment
Authors: Jiang Jia Wei , Liu Man Ping , Liu Yang , Tang Kai , Wang Zi Bo , Li Yi Chao , Yu Ying Da , Skaret Pål C. , Roven Hans J.
Published: November 2016

Microstructure and mechanical properties of a 6013 Al-Mg-Si-Cu aluminum alloy processed by a combination of equal channel angular pressing (ECAP) and preaging treatment were comparatively investigated using quantitative X-ray diffraction (XRD) measurements, transmission electron microscopy (TEM) and tensile tests. In addition, the precipitation sequences were obtained by thermodynamic calculations using the FactSage software package. Average grain sizes measured by XRD are in the range 211–501 nm while the average dislocation density is in the range 0.35-1.0 × 1014 m-2 in the deformed alloy. TEM analysis reveals that fine needle β′′ precipitates with an average length of 4-10 nm are uniformly dispersed in the preaging ECAPed alloy. The local dislocation density in this sample is as high as 2.2×1017 m-2. The strength is significantly increased in the preaging-ECAPed samples as compared to that of the undeformed counterparts. The highest yield strength among the preaging ECAPed alloys is 322 MPa. This value is about 1.25 times higher than that (258 MPa) of the static peak-aging sample. The high strength in the preaging ECAPed alloy is suggested to be related to grain size strengthening and dislocation strengthening, as well as precipitation strengthening contributed from both preaging treatment and ECAP deformation.
Characterization of Roping on AA6xxx Alloy Sheet by Numerical Analysis for Surface Topography
Authors: Takeshi Ichikawaa , Takaki Yasuo
Published: November 2016

AA6xxx alloys are known to suffer from a phenomenon called roping, which is a ridge and valley pattern appearing after stamping is treated as a fatal surface defect for the automotive skin panels. Although the roping is the important factor to determine the exterior quality, it is commonly evaluated by visual check done by inspecting staff, which is very subjective and difficult to measure quantitatively. In this study, to quantify the roping level in detail and easily, a new calculation method based on Fourier transform and using simple device to measure topography is proposed. As a result of analyses for several different AA6022 alloy sheets, it is found that the strong roping surface has the intensive directional pattern along the rolling direction with a specific wavelength. The roping level can be expressed numerically as the ratio between the amplitude of the rolling directional pattern and the average amplitude of each directional pattern. This value shows good agreement with the roping level determined by human observation. Moreover, it is found that the proposed method can be applied to the surface appearance obtained by digital camera without a 3D profiler.
Corrosion of Aluminium Aerospace Alloys
Authors: Staley J.T.
Published: November 2016

The Junkers F13 airplane, which began production in 1919, was the first plane to be built using aluminum aerospace alloys. Nearly 100 years later, approximately 1,800 new planes are being built each year with aluminum aerospace alloys. For the five trillion or so dollars worth of existing aging airplanes, cost of aerospace corrosion in United States alone is an estimated 23 billion dollars per year. In addition, hidden corrosion costs have contributed to a bigger impact in the commercial aircraft industry. In 1988, in the corrosion sensitive environment of the Hawaiian islands, an Aloha Airlines 737 aircraft suffered an in-flight failure due to crevice corrosion in the lap joint of the fuselage. After this event, the aviation technical community launched a new era of advanced technology, improved procedures and higher standards for maintaining the world’s aging and corroding aircraft. This paper discusses types of corrosion that affect aluminum aerospace alloys including crevice corrosion, pitting, exfoliation, intergranular, stress corrosion cracking (SCC) and corrosion fatigue. Standardized testing to determine if the alloy is susceptible to these types of corrosion is explained and examples of how to mitigate certain types of corrosion is discussed.
Intergranular Corrosion Mechanism of Brazed Al-Mn-Cu-Si Alloy
Authors: Yoshino Michihide , Iwao Shohei , Edo Masakazu , Chiba Hajime
Published: November 2016

This paper investigated the effect of Si addition on intergranular corrosion susceptibility for brazed Al–Mn–Cu alloy. Water-quenched samples have no intergranular corrosion (IGC) susceptibility, however, slowly cooled samples have IGC susceptibility. This implies that IGC susceptibility was caused by precipitation during cooling. In addition, IGC susceptibility depends on Si content. Low Si additive alloy has high IGC susceptibility. This is because the Mn/Cu depleted zone is formed near the grain boundary due to preferential precipitation of Mn-bearing compound and CuAl2 on the grain boundary. Conversely, optimum Si addition inhibits IGC due to the absence of preferential precipitation on the grain boundary. The excess Si alloy has high IGC susceptibility as the Si depleted zone is formed around the grain boundary due to the preferential precipitation of coarse Si particles on the grain boundary.
The Effect of Mg Content on Intergranular Corrosion of Al-Mg-Mn Alloys after Annealing
Authors: Ding Yu Sheng , Gao Kun Yuan , Lin Chang Jian , Wen Sheng Ping , Huang Hui , Wu Xiao Lan , Nie Zuo Ren , Zhou De Jing
Published: November 2016

The Intergranular Corrosion (IGC) properties of Al-xMg-0.6Mn (x=3, 4, 5, 6 and 7) wt.% alloys were studied using the mass loss test. The mass loss test results of the alloys annealed at 100-300 ̊C for 1h indicated that the alloys with 3 and 4% Mg were resistant to IGC. While the mass loss values of the 6 and 7% Mg alloys were increased to IGC severe sensitive region, and then abruptly fallen to the IGC-resistant region with the increasing temperature. The mass loss-temperature curve of 5% Mg alloy was actually located between them. After isothermal annealing, the mass loss results indicated a stabilization temperature of the alloys with 5, 6 and 7% Mg appeared at the temperature beyond 220 ̊C, 250 ̊C and 270 ̊C, respectively. Furthermore, below the stabilization temperature 10-20 ̊C, it was observed a type of “special mass loss curve ” in so-called transition region that was showed a quick mass loss increasing to sensitization region and then a decrease to the IGC resistant region with a prolonged annealing time. To explore the “special curve” in transition region, the TEM observation of Al-7Mg alloy annealing at 250 ̊C was conducted, which indicated the sensitization resulted from the continuity of β phase, while the descending to the IGC might to be attributed to the spheroidization of β phase.
Precipitation of ScAl3 Phase during Solutionizing and Ageing of Hypoeutectic Al-Sc Alloys and its Impact to Mechanical Properties
Authors: Tang Yun Yi , Liao Heng Cheng , Liu Ye
Published: November 2016

In this paper, precipitation of ScAl3 phase during solutionizing and ageing and its impact to mechanical properties of hypoeutectic Al-Sc alloy and effect of Sc addition amount were investigated by TEM and SEM microstructure observation and mechanical property testing. During solutionizing at 640oC for 24h, for Al-0.2wt.%Sc and Al-0.4wt.%Sc alloy, ScAl3 particles formed in the course of solidification become smaller, indicating, as a whole, Sc is partially dissolved into Al solution. Simultaneously, precipitation of two types of ScAl3 particles are observed by TEM. One has a size of 200~300nm, and the other is much small, 5~20nm in size. Though re-dissolution of Sc solute into Al solution and precipitation of large and fine ScAl3 particles occur in the solutionizing course, but the strength and hardness are decreased. The key reason for it is thought to be the softening effect of high level of vacancies in matrix lattice from the high solutionizing temperature. After further aging at 300oC for 3h, a great number of fine ScAl3 particles are precipitated in the Al matrix, which leads to a considerable precipitation hardening effect, thus the strength and hardness are increased obviously. Increasing the Sc content in the alloy results in a considerable rise in as-cast and as-aged strength and hardness, due to the solution strengthening and precipitation hardening respectively.
Effect of Homogenizing Treatment on Microstructure and Property of Al-Zn-Mg-Cu-Zr Aluminum Alloy
Authors: Wang Gao Song , Chen Qing Qiang , Tao Kai , Chen Qi Chao , Zhao Zhi Hao
Published: November 2016

A series of Al-6.3Zn-2.3Mg-2.3Cu-0.15Zr alloys with different reduce of Zn, Mg, Cu and Zr were prepared by ingot-metallurgy processing. Effects of homogenization on the microstructure and properties of Al-Zn-Mg-Cu-Zr aluminium alloy were respectively studied by means of metallographic microscopy, electrical conductivity test, differential thermal analysis and X-ray diffraction phase analysis. The results indicated that the overheating temperature of these alloys is between 473°C and 477°C, and there was little difference to the overheating temperature of 7050 alloy. During homogenization process, using three kinds of developed heat treatment of homogenization of 7050 alloy, with the rising of homogenization temperature and the complication of the homogenization heat treatment, the electrical conductivity decreased and hardness gradually increased. The three-step homogenization has a better effect than single homogenization, as it can completely eliminate the endothermic peak of non-equilibrium phases. Many MgZn2 phases are present in the ingot with three-step homogenization and slow cooling.
Effect of Solution Treatment on Microstructure and Mechanical Properties in an Al-9.3Zn-2.0Mg-1.8Cu Alloy
Authors: Wen Kai , Xiong Bai Qing , Zhang Yong An , Li Xi Wu , Li Zhi Hui , Huang Shu Hui , Liu Hong Wei , Yan Hong Wei
Published: November 2016

The microstructure solution treated by various temperatures of 2h in as-extruded Al-9.3Zn-2.0Mg-1.8Cu alloy was investigated by means of optical microscopy (OM), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), and differential scanning calorimetry (DSC) analysis. The mechanical properties treated at 465oC for various times were tested by room temperature tensile mechanical properties test. The results indicated that second phase of the as-extruded alloy mainly consists of Mg (Zn,Cu,Al)2 and Fe-rich phases. Mg (Zn,Cu,Al)2 phase completely dissolved into the matrix solution treated at 465oC or higher for 2h while residual phase was mainly Fe-rich phase. The mechanical properties treated at 465oC for various time were tested and optimized solution treatment parameter was chosen as 465°C/1.5h.
Rolling Texture Simulation of Aluminium Sheets Based on the Mechanism of Intergranule Reaction Stresses
Authors: Mao W.
Published: November 2016

Many efforts have been made to simulate the rolling texture evolution in polycrystalline Al for which strain and stress equilibrium of grains need to be considered. The conventional Taylor theory and its modifications, such as current VPSC, ALAMEL, GIA, fail to solve the problem of stress incompatibility between grains and their surrounding matrix properly. A reaction stress model is suggested for rolling deformation, which accounts both for stress and strain equilibrium and predicts similar textures as those by the Taylor theory. The corresponding detailed modification could reproduced the real rolling texture formation if the industrial rolling stress condition is included.
Effect of Natural Ageing on Strength and Anisotropy in Aluminium Alloy AA 6005C
Authors: Engler Olaf , Myhr Ole Runar
Published: November 2016

During processing of age-hardenable AA 6xxx series alloys for automotive applications the sheets may experience significant time spans between solution heat treatment at the aluminium supplier and age hardening upon the final paint bake cycle at the carmaker. Natural ageing during these pause times is known to greatly affect materials properties of autobody sheet. In the present study we explore the impact of natural ageing on the tensile properties and the in-plane anisotropy of alloy AA 6005C. Materials properties at various degrees of natural ageing are modelled with the help of a nanoscale material model NaMo, which consists of a precipitation model simulating the formation of clusters and phases upon natural ageing as input to a mechanical model simulating the evolution of yield strength and work hardening. Plastic anisotropy is modelled from the materials crystallographic texture by a visco-plastic self-consistent polycrystal-plasticity code VPSC.
Tensile Deformation Behavior of Al-Cu 206 Cast Alloys near the Solidus Temperature
Authors: Bolouri Amir , Chen X. Grant
Published: November 2016

To study the micromechanics of semisolid deformation, a modified experimental set-up is employed in Gleeble 3800 thermomechamical testing unit to achieve a uniform temperature distribution in partially remelted aluminum samples. The temperature variation was markedly reduced to one degree for a length of 4-5 mm in the middle of tensile samples. High temperature semisolid tensile tests of Al-Cu 206 cast alloys were performed at different temperatures near solidus with a strain rate of 10-3 s-1, corresponding to the solid fractions (fs) between 1 and 0.95. The stress-displacement curves with different fs were measured and analyzed. The microstructure and fracture surface of samples were examined by optical and scanning electron microscopes. The relation between the microstructural characteristics, tensile properties and fracture behavior of semisolid 206 samples at high fs were explored. Mush deformation mechanisms were discussed in term of defect nucleation and propagation at the late stage of solidification.
Fabrication of Vesicular Drug Delivery of Niosomal Topical Formulation for the Effective Treatment of Osteoarthritis
Authors: Nagalakshmi S. , Sandeep T. , Shanmuganathan S.
Published: November 2016

Delivery of drug through topical route, delivers most convenient and novel approach. The Skin can offer several advantages as a route of drug administration although its barrier nature makes it difficult for most drugs to penetrate in to and permeate through it. During the past decades there has been a lot of interest in lipid vesicles as a tool to improve topical drug delivery. Vesicular system such as liposomes, niosomes, ethosomes and elastic deformable vesicles provide an alternative for improved skin drug delivery. In fact vesicles can act as drug carriers controlling drug release. The Research findings were intended to develop sustained release of aceclofenac niosomes formulations in order to reduce gastrointestinal disturbances and to provide better effect when applied topically. Niosomes of aceclofenac was prepared by modified ether injection method using different ratio of surfactants (Tween 20, 40, 60 & 80) with cholesterol and drug. The developed formulations were optimized based on the high entrapment efficiency and in-vitro release studies. Optimized batch was selected and made in to topical niosomal gel using gelling agents like carbopol and sodium carboxy methyl cellulose. Formulation were evaluated for various parameters like vesicle shape, vesicle size, entrapment efficiency, drug content, compatibility studies, in-vitro release studies and stability studies. Ether injection method was found to be most satisfactory in terms of niosome particle size, drug entrapment efficiency was found to be 88.68 ±0.64 % and in-vitro release studies showed 40% of sustain drug release at the end of 8 hrs of study when compared with marketed formulation. Hence, the formulated niosomal topical gel was found to be a better alternative when compared to the marketed formulation in terms of better efficacy, bioavailability and permeation.
Folding-Refolding of Ferritin as Template in Design of Nanoclusters of Copper and Manganese Oxides
Authors: Subramanian Harshith , Jaganathan Maheshkumar , Dhathathreyan Aruna
Published: November 2016

Bio-templates such as proteins, lipids offer rich structural and functional diversity for the synthesis of nanoparticles by controlling their shape, size and orientation. In this work we have exploited a pH dependent folding-refolding feature of Horse Spleen Apoferritin (HsAFr) to synthesize copper and manganese oxide nanoparticles in a controlled manner. Two methods of preparation were used in this study. In the first method, Copper Sulphate (100 mM) and Manganese Chloride (4.8 mM) have been incubated with the protein and the pH dynamically adjusted for homogeneous incorporation of the metal ions into the HsAFr shell. The second study involved the incorporation of Cu2+ and Mn2+ inside HsAFr cavity and subsequent designing of nanoclusters of the respective oxides. UV, fluorescence and far-UV circular dichroism (far-UV CD) spectroscopic techniques have been used to study the mineralization effect of the metal inside the HsAFr cavity. Size determination carried out using XRD suggested an average size ranging from 20-30 nm. The EPR of the nanoclusters show that incorporation of Mn2+ leads to a characteristic magnetoferritin behavior.
Fabrication of Piezoelectric Polyvinylidene Fluoride (PVDF) Polymer-Based Tactile Sensor Using Electrospinning Method
Authors: Manikandan N. , Muruganand S. , Sriram K. , Balakrishnan P. , Suresh Kumar A.
Published: November 2016

The polyvinylidene fluoride (PVDF) nanofiber has widely investigated as a sensor and transducer material, because of its high piezo and Ferro electric properties. The novel nano structure of PVDF has attracted considerable interest in the bio sensing and biomedical application. This paper deals with PVDF Tactile sensor. Basically The PVDF acts as piezoelectric effect which convert load into electrical signals. The tactile sensor has a main role for visual handicap and robotics. Any physical activities of robotic in all industrial the tactile sensor is a crucible role, whether it can left the object or handling glass parts pressure of object is main. The Sandwich type PVDF base tactile sensor has been fabricated using nanofiber. Using electro spinning method, the PVDF based nanofiber coated over coper the electrodes. In normal, the PVDF has α-phase and while applying electric pulse the PVDF polymer would be changed from α-phase into β-phase. Only in β-phase, the PVDF act as piezo electrics sensor and measure the piezoelectricity simultaneously measure pressure and temperature in real time. The pressure was monitored from the change in the electrical resistance via the piezo resistance of the material. The enhancement of PVDF properties has been carried by using SEM. The SEM image result showed that the size of nanofiber, the size of nanofiber is varied in the range of (180 nm-400 nm) with smooth surface. The X-Ray diffraction has shown that the PVDF was aggregated with the β-phase crystalline nature. Due to β-phase it was act as a piezo electric prosperity’s and its results are very high sensitivity.
Micropropagation and Androgenesis in coconut: an assessment of Sri Lankan implication
Authors: Bandupriya H. D. D. , Fernando S. C. , Vidhanaarachchil Y. R. M.
Published: November 2016

The coconut palm is an important cash crop mostly in the sub-tropical countries which provides almost all the necessities of life to the mankind. Genetic improvement for increased productivity is a prioritized research area of coconut palm. In vitro cloning of elite palms via somatic embryogenesis seems to be a promising method due to its potential for massive propagation. Based on the Sri Lankan experience, this paper summarizes the notable achievements towards developing a reliable protocol for clonal propagation of coconut and also dihaploid plant production. The newel explants described by Coconut Research Institute Sri Lanka (CRISL), unfertilized ovaries dissected from immature inflorescences collected from -4 stage (inflorescence to be opened in 4 months time), is a somatic tissue which causes minimal damage to the mother palm while collecting. Limited number of female flowers in an inflorescence which limits large scale culturing could overcome by callus multiplication phase to produce higher number of plants. Somatic embryogenesis and germination of somatic embryos was achieved by reduction of auxin concentration in the culture medium followed by an addition of cytokinin. AINTEGUMENTA-LIKE (ANT-like) gene isolated from coconut genome which shows higher conserved domain sequence similarities with BABYBOOM gene will assist development of suitable molecular markers to assess the morphogenic potential of in vitro cultured coconut tissues and callus. Successful plant regeneration from cultured anthers was reported by culturing anthers at three weeks before splitting (3-WBS) inflorescence stage which contains late uninucleate microspores. Heat pretreatment of anthers for six days at 38°C induced androgenesis in coconut upon culturing in 2, 4-D and 1-naphthyl acetic acid (NAA) added medium. Current clonal propagation protocol is efficient when responsive genotype is in use.Further improvement to current protocol will enable commercially viable protocol for coconut micropropagation.
A survey of land for Weligama coconut leaf wilt disease affected palms outside the declared boundary in the Southern Province
Authors: Nainanayake A. D. , Kumarathunga M. D. P. , De Silva P. H. P. R.
Published: November 2016

After the identification of the Weligama Coconut Leaf Wilt Disease (WCLWD) in 2006, a three km wide boundary zone was declared which stretched from Galle to Tangalle. All suspicious palms recorded within the boundary zone were removed. Gradual removal of affected palms in the core area was also continued. These actions along with many other precautionary steps were taken with the objective to prevent the spread of the disease further beyond the demarcated boundary. After taking continued precautionary measures for more than 7 years, it was timely to find out the presence of any disease affected palms beyond the boundary. Therefore, a sample survey was conducted along a 4 km wide belt beyond the boundary. Uniform sampling locations were ensured by selecting sample sites on a I km grid drawn on the areal image of the area. Each grid covered an area of I km2 (100 ha). Four sampling locations/plots of approximately I ha in extent were selected within each grid. All coconut palms within selected plots were examined for morphological symptoms of the WCLWD and necessary information was recorded. The total area covered by the sample survey was about 40,000 ha and the extent closely examined was about 1600 ha, which was approximately 4% of the total land area covered by the survey. The results revealed that the precautionary measures taken by relevant authorities to prevent the spread of the WCLWD have had a significant effect in containing the disease within the demarcated area. However, some spread of the disease beyond the boundary was detected in a few places within the four-km-belt beyond the boundary. Thus altogether 18 affected palms were identified in 10 plots in Galle and Malara districts. They were in Akmeemana, Imaduwa and Yakkalamulla DSD in Galle district and Kamburupitiya and Mulatiyana DSD in Malara district. Most of those locations were adjacent to the boundary. However, any detection of even a few affected palms outside the boundary in a sample survey indicates the possibility of having such palms elsewhere in the study area. A comprehensive palm to palm survey is needed for precise detection of such palms. Considering the impending threat from the disease, a palm to palm survey at least within a 4 km belt outside the boundary is suggested to effectively prevent the spread of the disease, despite the cost and the man power required for such an operation.
Incidence ofMonochamus(Coleoptera: Cerambycidae) species in Nova Scotia, Canada Christmas tree plantations and comparison of panel traps and lures from North America and Europe
Authors: Blatt S.E. , Bishop C. , Sweeney J.
Published: November 2016

Christmas trees from Nova Scotia, Canada are banned from import into the European Union (EU) because they may be infected with the pinewood nematode,Bursaphelenchus xylophilus(Steiner and Buhrer) Nickle (Nematoda: Parasitaphelenchidae).MonochamusDejean (Coleoptera: Cerambycidae) species known to vector pinewood nematode are present in Nova Scotia but their abundance in Christmas tree plantations and surrounding stands has not been assessed. We conducted trapping surveys and experiments in 2014 and 2015 to determine the species ofMonochamusand their relative abundance in Nova Scotia Christmas tree plantations and the surrounding forests. We also compared commercially available traps and lures from Europe (cross-vane traps, Galloprotect lure=monochamol+ipsenol+α-pinene+2-methyl-3-buten-2-ol) and North America (intercept panel traps, North American lure=monochamol+ipsenol+α-pinene+ethanol) for their efficacy at catchingMonochamusspecies in a 2×2 factorial experiment. We captured threeMonochamusspecies (M. scutellatus(Say),M. notatus(Drury), andM. marmoratorKirby) in Nova Scotia Christmas tree plantations. Mean trap catches were greater within the plantations than in the surrounding forests. North American panel traps coated with Fluon®and baited with the European lure caught the mostM. notatusandM. scutellatusand would be most suitable for survey and monitoring.
Lung Cancer Subtypes Generate Unique Immune Responses
Authors: Busch Stephanie E. , Hanke Mark L. , Kargl Julia , Metz Heather E. , MacPherson David , Houghton A. McGarry
Published: November 2016

Lung cancer, the leading cause of cancer-related deaths worldwide, is a heterogeneous disease comprising multiple histologic subtypes that harbor disparate mutational profiles. Immune-based therapies have shown initial promise in the treatment of lung cancer patients but are limited by low overall response rates. We sought to determine whether the host immune response to lung cancer is dictated, at least in part, by histologic and genetic differences, because such correlations would have important clinical ramifications. Using mouse models of lung cancer, we show that small cell lung cancer (SCLC) and lung adenocarcinoma (ADCA) exhibit unique immune cell composition of the tumor microenvironment. The total leukocyte content was markedly reduced in SCLC compared with lung ADCA, which was validated in human lung cancer specimens. We further identified key differences in immune cell content using three models of lung ADCA driven by mutations in Kras, p53, and Egfr. Although Egfr-mutant cancers displayed robust myeloid cell recruitment, they failed to mount a CD8+ immune response. In contrast, Kras-mutant tumors displayed significant expansion of multiple immune cell types, including CD8+ cells, regulatory T cells, IL-17A–producing lymphocytes, and myeloid cells. A human tissue microarray annotated for KRAS and EGFR mutations validated the finding of reduced CD8+ content in human lung ADCA. Taken together, these findings establish a strong foundational knowledge of the immune cell contexture of lung ADCA and SCLC and suggest that molecular and histological traits shape the host immune response to cancer.
The diagnostic-clinical chasm: Work in progress?
Authors: Nkengasong John N.
Published: November 2016

No abstract available.
Health-related quality of life of antiretroviral treatment defaulters in Botswana
Authors: Ndubuka Nnamdi O. , Lim Hyun J. , Van der Wal Dirk M. , Ehlers Valerie J.
Published: November 2016

Background: Antiretroviral therapy (ART) improves patients’ health-related quality of life (HRQoL). Defaulting from ART has detrimental consequences, including the development of viral resistance, treatment failure and increased risks of disease progression. Little is known about the quality of life of ART defaulters and reasons for discontinuing their ART.Objectives: This study sought to measure the HRQoL of ART patients in Botswana who were on ART for up to 5 years but had discontinued treatment for at least 3 months, and to identify factors associated with ART defaulting.Method: We conducted a cross-sectional study with 104 eligible respondents in four ART clinics in south eastern Botswana. We assessed respondents’ HRQoL using the World Health Organization Quality of Life Questionnaire for HIV short form. Clinical information was obtained from respondents’ medical records. Data were analysed using SAS version 9.2.Results: Reasons for discontinuing ART were inaccessible clinics (22.4%), feeling better (21.4%), running out of pills (11.2%), depression (8.2%), lack of care and/or support (8.2%), failure to understand instructions (7.7%), medications’ side effects (6.1%) and alcohol abuse (3.1%). In multivariate analyses, respondents aged 36–45 years had a 0.03 lower independence HRQoL score compared to those aged 35 and younger (β = -0.03; 95% confidence interval: -1.72, -1.66). Despite defaulting from their ART, respondents’ calculated HRQoL scores wereConclusion: This study highlights the need to enhance ART adherence in order to improve the HRQoL of people living with HIV and/or AIDS.
Evaluation of Knowledge and Practices Regarding Cholera, Water Treatment, Hygiene, and Sanitation Before and After an Oral Cholera Vaccination Campaign—Haiti, 2013–2014
Authors: Childs Lana , François Jeannot , Choudhury Alina , Wannemuehler Kathleen , Dismer Amber , Hyde Terri B. , Yen Catherine Y. , Date Kashmira A. , Juin Stanley , Katz Mark A. , Kantor Erica Felker , Routh Janell , Etheart Melissa , Wright Tracie , Adrien Paul , Tohme Rania A.
Published: November 2016

In 2013, the Government of Haiti implemented its first oral cholera vaccine (OCV) campaign in Petite Anse, an urban setting, and Cerca Carvajal, a rural commune. We conducted and compared responses to two independent cross-sectional knowledge and practices household surveys pre- (N = 297) and post- (N = 302) OCV campaign in Petite Anse. No significant differences in knowledge about causes, symptoms, and prevention of cholera were noted. Compared with precampaign respondents, fewer postcampaign respondents reported treating (66% versus 27%, P < 0.001) and covering (96% versus 89%, P = 0.02) their drinking water. Compared with precampaign, postcampaign survey household observations showed increased availability of soap (16.2% versus 34.5%, P = 0.001) and handwashing stations (14.7% versus 30.1%, P = 0.01), but no significant changes in handwashing practices were reported. Although there was no change in knowledge, significant decreases in water treatment practices necessary for cholera and other diarrheal diseases prevention were noted in the postcampaign survey. Future OCV campaigns in Haiti should be used as an opportunity to emphasize the importance of maintaining good water, sanitation, and hygiene practices, and include a comprehensive, integrated approach for cholera control.
Serological Responses to Filarial Antigens in Malian Children Attending Elementary Schools
Authors: Moss Delynn M. , Chard Anna N. , Trinies Victoria , Doumbia Seydou , Freeman Matthew C. , Lammie Patrick J.
Published: November 2016

Dried blood spots (DBS) were collected from 805 children attending 42 elementary schools in the regions of Mopti, Sikasso, Koulikoro, and the regional capital of Bamako in Mali as part of an evaluation of a school health intervention. Eluted immunoglobulin (Ig) G from the DBS was assessed by a multiplex bead assay (MBA) for two filariasis antigens, Wuchereria bancrofti, Wb123, and Brugia malayi, Bm14, to determine the effectiveness of mass drug administration (MDA) programs to eliminate lymphatic filariasis (LF). The prevalence of positive IgG responses in the children to each antigen was less than 1%, indicating effectiveness of the MDA against LF. The MBA is an excellent serological platform that provides cost-effective opportunities to evaluate public health activities beyond the survey targets.
Referral Patterns of Community Health Workers Diagnosing and Treating Malaria: Cluster-Randomized Trials in Two Areas of High- and Low-Malaria Transmission in Southwestern Uganda
Authors: Lal Sham , Ndyomugenyi Richard , Magnussen Pascal , Hansen Kristian S. , Alexander Neal D. , Paintain Lucy , Chandramohan Daniel , Clarke Siân E.
Published: November 2016

Malaria-endemic countries have implemented community health worker (CHW) programs to provide malaria diagnosis and treatment to populations living beyond the reach of health systems. However, there is limited evidence describing the referral practices of CHWs. We examined the impact of malaria rapid diagnostic tests (mRDTs) on CHW referral in two cluster-randomized trials, one conducted in a moderate-to-high malaria transmission setting and one in a low-transmission setting in Uganda, between January 2010 and July 2012. All CHWs were trained to prescribe artemisinin-based combination therapy (ACT) for malaria and recognize signs and symptoms for referral to health centers. CHWs in the control arm used a presumptive diagnosis for malaria based on clinical symptoms, whereas intervention arm CHWs used mRDTs. CHWs recorded ACT prescriptions, mRDT results, and referral in patient registers. An intention-to-treat analysis was undertaken using multivariable logistic regression. Referral was more frequent in the intervention arm versus the control arm (moderate-to-high transmission, P < 0.001; low transmission, P < 0.001). Despite this increase, referral advice was not always given when ACTs or prereferral rectal artesunate were prescribed: 14% prescribed rectal artesunate in the moderate-to-high setting were not referred. In addition, CHWs considered factors alongside mRDTs when referring. Child visits during the weekends or the rainy season were less likely to be referred, whereas visits to CHWs more distant from health centers were more likely to be referred (low transmission only). CHWs using mRDTs and ACTs increased referral compared with CHWs using a presumptive diagnosis. To address these concerns, referral training should be emphasized in CHW programs as they are scaled-up.