International Journal of Material and Mechanical Engineering
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Open Access journal
ISSN (Print) 2162-0695 - ISSN (Online) 2164-280X
Published by Science and Engineering Publishing Company [49 journals]
- A Review on the Influence of Applied Potential on Different Electrical
Properties of Self-Assembled Monolayers (SAMs) of Alkanethiols on Gold
Abstract: A Review on the Influence of Applied Potential on Different Electrical Properties of Self-Assembled Monolayers (SAMs) of Alkanethiols on Gold (Au) Surface
Author M. Jalal UddinM. Abdul MominM. Abdur RazzaqueM. ShahinuzzamanM. Khairul IslamWayesh QaronyIsmail Hossai
Self-assembled monolayers (SAMs) of alkanethiols are commonly used in surface patterning, as well as in modifying the physical and chemical properties of surface. Therefore, the understanding of the formation of self-assembled monolayers (SAMs), including its structure and different properties requires significant importance. Among a wide variety of organic molecules used for self-assembly, alkanethiols and their derivatives on gold surface are the mostly studied. Because the alkanethiols based monolayers on gold layer prepared either using the flexible or rigid substrate are stable and possess well-packed structure. Self-assembled monolayers (SAMs) of alkanethiols on gold (Au) have many significant applications. Among them, the applications in the field of interfacial electron transfer, sensing, developing selected electrodes, and fabricating lipid bilayers on electrodes are remarkable. Hence, the intensive study of the different electrical properties of self-assembled monolayers (SAMs) is noteworthy for the devices fabrication. This review work is to report on the influence of applied potential on different electrical properties of self-assembled monolayers (SAMs) of alkanethiols on conductive gold (Au) surface. The work will essentially focus on different techniques of self-assembling, discussion on the arrangement and structure, and the influence of applied potential on different electrical properties like SAM resistance, capacitance, impedance etc.
- Droplet Evaporation Behavior of Kerosene/Nano-Aluminum Fuels at High
Abstract: Droplet Evaporation Behavior of Kerosene/Nano-Aluminum Fuels at High Pressure Environment
Author DongMin KimSeungWook Bae
This experimental study investigated the effects of nanoparticles on evaporation rate of kerosene based nanofluid fuels in high pressure environment. The base liquid fuel was kerosene and aluminium (Al) nanoparticles with average 70 nm diameter were used. Evaporation behaviour was recorded and investigated by suspending the droplet on the silicon carbide (SiC) fiber with 0.1 mm diameter in high pressure chamber. Oleic acid was used as a surfactant to synthesize the stable nanofluid fuels and the effect of oleic acid, of course, was investigated for comparison. The concentrations of aluminium nanoparticles were 0.1 % and 1.0 % by mass fraction and the ambient pressure was increased from 0.1 MPa to 2.5 MPa. The temperature raged 300 ℃ to 700 ℃. The results showed that in high temperature region the pure kerosene droplet vaporized faster with pressure increase but in low temperature region the evaporation rate of pure kerosene droplet decreased with pressure increase. For all aluminium-kerosene nanofluid fuel droplets, regardless of the concentration, the evaporation rate was higher than that of pure kerosene droplets.
- Finite Element Simulation on Cross Shear Ratio in Asymmetrical Rolling
Abstract: Finite Element Simulation on Cross Shear Ratio in Asymmetrical Rolling
Author Delin TangXianghua LiuMeng SongXiangkun Su
The formula for calculating neutral angles and cross shear ratio in asymmetrical rolling was established in this study. The influences of asymmetrical ratio, friction coefficient, elongation to the value of cross shear ratio were analyzed by calculation and simulation. Finite element simulation on shearing stress state in the deformation region had been done by ABAQUS. The results of simulation showed the variation trend of cross shear ratio along with the three parameters above and proved that the formulae for calculating the cross shear ratio were consistent with the reality.
- Link Between Technological Parameters and Material Properties of EN 6082
Processed by ECAP-CONFORM and Precipitation Hardening
Abstract: Link Between Technological Parameters and Material Properties of EN 6082 Processed by ECAP-CONFORM and Precipitation Hardening
Author Tomas KubinaMichal KoverJaromir DlouhyJan Nachaze
Influence of severe plastic deformation on aging kinetics of aluminium alloys was widely studied in last decade. Therefore serious amount of data is available for thermomechanical treatment of 6082 alloy by ECAP coupled with precipitation hardening. However, the industrial processing continuous methods, such as the ECAP-CONFORM, are more perspective. Therefore the influence of processing parameters - time and temperature in ECAP-CONFORM device, and their links to aging parameters are explored in this paper. The alloy was naturally and artificially aged after sever plastic deformation in ECAP-CONFORM device. Two artificial aging temperatures were chosen: 130 °C and 160 °C. Influence of aging time on mechanical properties was studied and the results were compared with those of non-deformed specimens. Temperature in ECAP-CONFORM chamber was measured directly and possible recovery and recrystallization temperatures were measured by dilatometry. Grain size and orientation were observed by EBSD-SEM.
- Degradation Study of 316L Stainless Steel Implantsin the Presence of
Solution Physiological Hartman
Abstract: Degradation Study of 316L Stainless Steel Implantsin the Presence of Solution Physiological Hartman
Author Araceli Salazar PeraltaR. H. ChávezJ.A PichardoG. Hernánde
Organic fluids are extremely hostile to metallic materials, as well as their effects on these implants and on the surrounding tissues, it is of fundamental importance. The use of stainless steel alloys for permanent implants in developing countries is common, so it is necessary to increase knowledge about the behavior of these materials in physiological media. This study was conducted in gravimetrically by subjecting samples of 316L stainless steel screws in Hartman solution for 360 hours at 45 ° C, pH 6.5, yielding very good corrosion resistance of 3.2x10_2 millimeters per year (mm / y). The surface presented pitting points of corrosion in the valley zone produced by the chloride ions present in the solution. This study is the beginning of many moreaspects thatis needed to determine the use of the implants.
- A Facile Electrochemical Biosensor for the Detection of microRNA Based on
Abstract: A Facile Electrochemical Biosensor for the Detection of microRNA Based on Graphene Sheets/Polyaniline/AuNPs
Author Xueping ChenDandan ZhouHuawei ShenWenli FengHui ChenGuoming Xi
A facile, highly sensitive electrochemical biosensor was designed to determine microRNA based on graphene sheets/polyaniline/AuNPs (GS/PANI/AuNPs) nanocomposites. Firstly, GS/PANI/AuNPs was synthesized using a one-step and green approach by polymerizing aniline with chloroaurate acid as the oxidant. Then, GS/PANI/AuNPs was re-suspended in chitosan (CS) solution and fabricated onto the surface of glassy carbon electrode (GCE) to enhance the conductivity and immobilize hairpin capture probe (S). In the presence of target RNA, the RNA hybridized with the loop of S, followed by covalently binding of streptavidin-alkaline phosphatase (SA-ALP). Current signal was gained by differential pulse voltammetry (DPV) in the working buffer containing 1-naphthyl phosphate (1-NP). The biosensor exhibited high sensitivity toward microRNA, resulting in a wide linear range from 1.25×10 -12 M to 5×10 -8 M with a detection limit of 0.25 pM (S/N = 3).
- A One-Dimensional Lumped-Mass Model for a Rubber Bushing and Its
Application to the Calculation of Dissipation Energy
Abstract: A One-Dimensional Lumped-Mass Model for a Rubber Bushing and Its Application to the Calculation of Dissipation Energy
Author Zhengui ZhangHaiyan H Zhan
Modal analysis is employed in this paper using hammer impact testing to characterize the dynamic response of rubber bushing. Based on multi-body dynamic analysis and acceleration transfer function, the rubber core is decomposed into three pieces, which are joined by spring and dashpot considering the large deformation and damping properties. Parameters of mass, stiffness and damping coefficients are identified through fitting against the Bode plot of the transfer function. With those parameters, the stability of this structure can be evaluated by exploring the critical excitation frequency range, which attributes the failure mechanism of rubber to thermal effect. The dissipation energy in each piece of the rubber core is calculated to demonstrate the accumulation of energy in rubber bushing. This paper successfully employs multi-body analysis to predict the dissipation energy of rubber components.
- 3D Flexible, Conductive and Wearable Fabric Strain Sensors
Abstract: 3D Flexible, Conductive and Wearable Fabric Strain Sensors
Author Bingang XuJianfeng LiXiaoming TaoHong H
3D fabrics are flexible and wearable substrates for making functional apparels and relevant medical equipments with many distinguished qualities. This paper proposes an easily-fabricated method for 3D fabric pressure sensor based on carbon black coated 3D textile fabrics. The as-made sensor is flexible, conductive and stable even after many times of cyclic compressions. It can measure external pressure ranging from 0 to 33 kPa. During the compression process of the sensor, its electrical resistance would decrease due to conductive structure deformation. The sensor has the potential to transfer pressure information into the change of electrical resistance of the sensor, which is more easily acquirable and readable. This property of the sensor can find promising applications in many fields.
- Stability of Grain Yield of Maize Hybrids in Eight Environments in Mali
Abstract: Stability of Grain Yield of Maize Hybrids in Eight Environments in Mali
Author Coulibaly Mamadou MoryNiaba TemeEssie BlayVernon GracenLate the Charle
Maize is produced in varying environment dictating yield performance and stability in Mali. To validate yield and stability performance, 78 hybrids and 2 checks were tested across eight environments at six sites in Mali during the rainy season of 2011. Two planting dates were used in Sotuba and Siramana locations to create additional environments. The hybrids were evaluated in Randomized Complete Block Design with two replications for one year. The objectives were (1) to study the nature and the magnitude of the genotype x environment interaction and (2) the grain yield stability within and across environments. Sotuba 1, Sotuba 2, Kebila and Kafara were high yielding environments characterized by better performance and very high yield. Siramana 1, Siramana 2, Tamala, and Koulikoro were low yielding environments which was determined with GGE biplot analysis. Nine hybrids were stable across the high yielding environments. Across the low yielding sites, twenty two hybrids exhibited stable performance. Seven Inbred lines showed positive GCA in high yielding environments indicating a predominance of additive gene action. The best SCAs were obtained with P43SRC9FS100-1- 1-8/V481-73, CML442/87036 and (KU1403x1368)/CML505. The hybrid with the best SCA value P43SRC9FS100-1-1- 8/V481-73 was from parents exhibiting the highest GCA values.